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[0001] The present application is a continuation application of PCT/JP01/10020 filed on Nov. 16, 2001, claiming priority from a Japanese patent application No. 2000-360076 filed on Nov. 27, 2000, the contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an electron beam exposure apparatus and an electron beam generating device for exposing a wafer by an electron beam. More particularly, it relates to an electron beam exposure apparatus and an electron beam generating device which prevents electric discharge between an insulator, on which an electron gun is mounted, and ground potential.
[0004] 2. Description of Related Art
[0005] With miniaturization of semiconductor devices in recent years, improvement in irradiation uniformity of an electron beam in an electron beam exposure apparatus is required. The irradiation uniformity of the electron beam is deteriorated by change of potential difference between a cathode and a grid in the electron beam exposure apparatus, exhaustion of the cathode, etc. Conventionally, the potential difference between the cathode and the grid is adjusted by an element called self-bias resistance.
[0006] On the other hand, since there is no effective remedy for preventing the exhaustion of the cathode, it has been desired to extend the service life of the cathode. The cause of the cathode exhaustion greatly originates in decreasing of the degree of vacuum in the vacuum area of the electron beam exposure apparatus due to, for example, the electric discharge in the vicinity of the electron beam generating device. Discharge gas is generated in an electric discharge path by the energy release during the electric discharge, the discharge gas is ionized by the electron beam, and the cathode is spattered with the ionized discharge gas, by which the cathode is exhausted.
[0007] In the conventional electron beam exposure apparatus, thermal electrons emitted from cathode are accumulated in an insulating part of an insulator, the electric discharge occurs by the accumulated thermal electrons, and the degree of vacuum of the vacuum area is decreased. The electric discharge on the surface of the insulator generates the great amount of the discharge gas, and degrades the degree of vacuum more than an order of magnitude. Moreover, due to the electric discharge on the surface of the insulator, the acceleration voltage for accelerating the thermal electrons emitted from the cathode in the direction of the wafer is fluctuated, the current of the electron beam is also fluctuated, and accuracy of the wafer exposure was degraded.
SUMMARY OF THE INVENTION
[0008] Therefore, it is an object of the present invention to provide a testing device which can solve the foregoing problem. The above and other objects can be achieved by combinations described in the independent claims. The dependent claims define further advantageous and exemplary combinations of the present invention.
[0009] According to the first aspect of the present invention, there is provided an electron beam generating device for generating an electron beam. The electron beam generating device includes: a cathode for generating thermal electrons; a cathode voltage source for applying negative voltage to the cathode so that the thermal electrons are emitted from the cathode; a grid for collecting the thermal electrons emitted from the cathode and forming the electron beam; a grid voltage source for applying negative voltage to the grid, the potential of the grid being lower than that of the cathode; and an insulator for insulating the cathode voltage source and the grid voltage source from the thermal electrons generated by the cathode. At least a part of outer surface of the insulator is covered with high-resistance film.
[0010] In the first aspect of the present invention, it is preferable that the outer surface of the insulator is covered with the high-resistance film or conductor. Moreover, it is preferable that an upper portion of the high-resistance film electrically connects with a reference potential unit having reference potential. Moreover, it is preferable that a lower portion of the high-resistance film electrically connects with the grid. Moreover, the insulator may include a first electrode on the outer surface, the first electrode being electrically connected to the reference potential unit, and the upper portion of the high-resistance film may be electrically connected to the first electrode. Moreover, the insulator may include a second electrode on the outer surface, the second electrode being electrically connected to the grid, and the lower portion of the high-resistance film may be electrically connected to the second electrode. Moreover, the high-resistance film of the insulator may include metal oxide. The metal oxide may be indium oxide.
[0011] According to the second aspect of the present invention, there is provided an electron beam exposure apparatus for exposing a wafer by an electron beam. The electron beam exposure apparatus includes: an electron beam generating device for generating the electron beam; a deflector for deflecting the electron beam to a predetermined position on the wafer; and a stage for supporting the wafer. The electron beam generating device includes: a cathode for generating thermal electrons; a cathode voltage source for applying negative voltage to the cathode so that the thermal electrons are emitted from the cathode; a grid for collecting the thermal electrons emitted from the cathode and forming the electron beam; a grid voltage source for applying negative voltage to the grid, the potential of the grid being lower than that of the cathode; and an insulator for insulating the cathode voltage source and the grid voltage source from the thermal electrons generated by the cathode. At least a part of outer surface of the insulator is covered with high-resistance film.
[0012] In the second aspect of the present invention, The electron beam exposure apparatus may further include: a chamber for storing the electron beam generating device, the deflector, and the stage; and a pressure reduction means for reducing pressure inside the chamber. A vacuum area, which is an area evacuated by the pressure reduction means, in the chamber may be surrounded with the high-resistance film or a conductor. An upper portion of the high-resistance film may electrically connect with the chamber.
[0013] The summary of the invention does not necessarily describe all necessary features of the present invention. The present invention may also be a sub-combination of the features described above.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] [0014]FIG. 1 shows a configuration of the electron beam exposure apparatus according to an embodiment of the present invention.
[0015] [0015]FIG. 2 is a drawing exemplary showing a configuration of an electron beam generating device.
DETAILED DESCRIPTION OF THE INVENTION
[0016] The invention will now be described based on the preferred embodiments, which do not intend to limit the scope of the present invention, but exemplify the invention. All of the features and the combinations thereof described in the embodiment are not necessarily essential to the invention.
[0017] [0017]FIG. 1 shows a configuration of the electron beam exposure apparatus 300 according to an embodiment of the present invention. The electron beam exposure apparatus 300 includes an exposure section 350 for performing a predetermined exposure processing on the wafer 392 by an electron beam, and a control system 340 for controlling operation of each component of the exposure section 350 .
[0018] The exposing unit 350 includes an electron optics system which includes an electron beam forming means 360 for generating a plurality of electron beams and forming cross-sectional shape of the electron beams into desired forms inside a chamber 352 , an irradiation switching means 370 for independently switching whether or not the plurality of electron beams are to be irradiated on the wafer 392 , and a wafer projection system 380 for adjusting direction and size of an image of a pattern which is transcribed on the wafer 392 . The exposing unit 350 also includes a stage section including a wafer stage 396 for supporting the wafer 392 on which the pattern is exposed, and a wafer stage drive unit for driving the wafer stage 396 .
[0019] The electron beam forming means 360 includes a plurality of electron beam generating apparatuses 100 for generating a plurality of electron beams, a first forming member 362 and a second forming member 372 having a plurality of apertures which form the cross-sectional shapes of the irradiated electron beams by allowing the electron beams to pass through the apertures, a first multi-axis electron lens 364 for adjusting focal points of the plurality of electron beams by independently collecting each of the plurality of electron beams, and a first forming deflector 366 and a second forming deflector 368 for independently deflecting the plurality of electron beams which have passed through the first forming member 362 .
[0020] Each of the electron beam generating apparatuses 100 includes: a cathode 10 for generating thermal electrons; a cathode voltage source for applying negative voltage to the cathodes 10 so that the thermal electrons are emitted from the cathodes 10 ; a grid 30 for collecting the thermal electrons emitted from the cathode 10 , and for forming the electron beam; a grid voltage source for applying negative voltage, which is lower than the voltage of the cathode 10 , to the grid 30 ; and an insulator 40 for insulating the cathode voltage source and the grid voltage source from the thermal electrons generated by the cathode 10 . At least a part of outer surface of the insulator 40 is covered with high electric resistance film. According to the present embodiment, an upper portion of the high electric resistance film connects with the chamber 352 , and the chamber 352 is grounded. A lower portion of the high electric resistance film electrically connects with the grids 30 via a field limiting flange. Negative voltage is applied to the grid 30 from the grid voltage source, and substantially the same electric potential as the grid 30 is applied to the lower portion of the high electric resistance film. Feeble current flows on the high electric resistance film by electric potential difference between the upper portion of the high electric resistance film and the lower portion of the high electric resistance film, so that accumulation of the thermal electrons emitted from the cathode 10 on a surface of the insulator 40 is avoided.
[0021] The exposure switching unit 370 includes a second multi-axis electron lens 374 for adjusting focal points of a plurality of electron beams by independently collecting each of a plurality of electron beams, a blanking electrode array 376 for independently switching whether or not each of the electron beams is to be irradiated on the wafer 392 by deflecting each of the plurality of electron beams independently, and an electron beam blocking unit 382 , which includes a plurality of apertures through which the electron beams pass, for blocking the electron beam deflected by the blanking electrode array 376 . In another embodiment, the blanking electrode array 376 is a blanking aperture array device.
[0022] The wafer projection system 380 includes a third multi-axis electron lens 378 for independently collecting each of a plurality of electron beams and decreasing irradiated cross-sectional area of the electron beams, a fourth multi-axis electron lens 384 for independently collecting each of a plurality of electron beams and adjusting a focal point of each of the electron beams, a deflecting unit 386 for independently deflecting each of the plurality of electron beams into a desired location on the wafer 392 , and a fifth multi-axis electron lens 388 , which acts as an object lens for the wafer 392 , for independently collecting each of the plurality of electron beams.
[0023] The control system 340 includes a general control unit 330 and an individual control unit 320 . The individual control unit 320 includes an electron beam control section 332 , a multi-axis electron lens control section 334 , a forming deflection control section 336 , a blanking electrode array control section 338 , a deflection control section 340 , and a wafer stage control section 342 . For example, the general control unit 330 is a workstation which generally controls each of the controllers included in the individual control unit 320 .
[0024] The electron beam control section 332 controls the electron beam generating apparatus 100 . The multi-axis electron lens control section 334 controls electric current provided to the first multi-axis electron lens 364 , the second multi-axis electron lens 374 , the third multi-axis electron lens 378 , the fourth multi-axis electron lens 384 , and the fifth multi-axis electron lens 388 . The forming deflection control section 336 controls the first forming deflector 366 and the second forming deflector 368 . The blanking electrode array control section 338 controls voltage applied to deflection electrodes of the blanking electrode array 376 . The deflection control section 344 controls voltage applied to the deflection electrodes of a plurality of deflectors of the deflecting unit 386 . The wafer stage control section 342 controls the wafer stage driver 398 so that the wafer stage 396 is caused to move to a predetermined location.
[0025] [0025]FIG. 2 is a drawing exemplary showing a configuration of the electron beam generating device 100 . The electron beam generating apparatus 100 includes: a cathode 10 for generating thermal electrons; a cathode voltage source 22 for applying negative voltage to the cathode 10 so that the thermal electrons are emitted from the cathodes 10 ; a grid 30 for collecting the thermal electrons emitted from the cathode 10 , and for forming the electron beam; a grid voltage source 24 for applying negative voltage, which is lower than the voltage of the cathode 10 , to the grids 30 ; an insulator 40 for insulating the cathode voltage source 22 and the grid voltage source 24 from the thermal electrons generated by the cathode 10 ; and a field limiting flange 12 for adjusting the electric field. At least a part of outer surface of the insulator 40 is covered with high-resistance film 20 . Alternatively, the insulator 40 includes the first electrode 16 on its outside, which is conductor electrically connects with a reference potential section, and the upper portion of the high-resistance film 20 electrically connected to the first electrode 16 . It is preferable that the first electrode 16 electrically connects with the reference potential through the chamber 352 .
[0026] Moreover, it is preferable that the lower portion of the high-resistance film 20 electrically connects with the grid 30 . For example, the insulator 40 includes a second electrode 14 on its outside, which is conductor electrically connected to the grid 30 , and the lower portion of the high-resistance film 20 electrically connects with the second electrode 14 . By applying substantially the same electric potential as that of the grid 30 to the lower portion of the high-resistance film 20 and applying the approximate reference potential to the upper portion of the high-resistance film 20 , feeble current flows between the upper portion and the lower portion of the high-resistance film 20 , and accumulation of the thermal electrons on the high-resistance film 20 is prevented.
[0027] The insulator 40 is fixed to the upper portion of the chamber 352 , and the thermal electrons emitted from the cathode 10 are collected by the grid 30 and irradiated on the wafer 392 as an electron beam. Since at least a part of the outer surface of the insulator 40 is covered with the high-resistance film 20 to generate the potential difference between the upper portion and the lower portion of the high-resistance film 20 , even if the thermal electrons emitted from the cathode 10 reaches the outer surface of the insulator 40 , the thermal electrons are not accumulated on the insulator 40 .
[0028] It is preferable that the electron beam generating apparatus 300 further includes a pressure reduction means 70 for reducing a pressure inside the chamber 352 . It is also preferable that a vacuum area 60 , where the pressure is reduced by the pressure reduction means 70 , in the chamber 352 is surrounded by the high-resistance film 20 or the conductor. That is, it is preferable that insulating material is not exposed inside the vacuum area 60 of the chamber 352 . In the present embodiment, the outer surface of the insulator 40 is covered with the high-resistance film 20 or the conductor. Moreover, it is preferable that the pressure reduction means 70 is capable of reducing the pressure of the vacuum area 60 of the chamber 352 to about 7.5×10 −11 Pascal (1×10 −8 torr). By covering the outer surface of the insulator 40 with the high-resistance film 20 or the conductor, the insulating material 18 of the insulator 40 is isolated from the vacuum area 60 , and accumulation of electric charge by the thermal electrons is prevented.
[0029] Moreover, it is preferable that the upper portion of the high-resistance film 20 connects with the chamber 352 . By connecting the upper portion of the high-resistance film 20 and the chamber 352 , the electric charge of the thermal electrons which reached the high-resistance film 20 flows to the reference potential through the chamber 352 before starting discharging the accumulated charges. In the present embodiment, although the upper portion of the high-resistance film 20 electrically connects with the reference potential through the chamber 352 and the first electrode, in another embodiment, the upper portion of the high-resistance film 20 electrically connects with the reference potential.
[0030] It is preferable that a value of resistance of the high-resistance film 20 is selected so as to prevent overload of the grid voltage source 24 . For example, when a voltage of −50 kilovolts is applied to the grid 30 , it is preferable that the resistance between the upper portion of the high-resistance film 20 and the lower portion of the high-resistance film 20 is in the neighborhood of 0.5 to 500 gigaohms. In this case, the current of about 0.1-100 microamperes flows between the upper portion and the lower portion of the high-resistance film 20 , so that the accumulation of the electric charge due to the thermal electrons on the high-resistance film 20 is prevented, and the overload of the grid voltage source 24 is also prevented.
[0031] It is preferable that the high-resistance film 20 includes metal oxide, such as indium oxide. In this case, the high-resistance film 20 may be hyaline material in which the indium oxide is mixed substantially evenly. By the high-resistance film 20 including the indium oxide, it is easy to manufacture the high-resistance film 20 of which the value of resistance between the upper portion of the high-resistance film 20 and the lower portion of the high-resistance film 20 is in the neighborhood of 0.5 to 500 gigaohms.
[0032] Moreover, in the present embodiment, while the lower portion of the high-resistance film 20 electrically connects with the grid 30 and the electric potential of the high-resistance film 20 is substantially the same as that of the grid 30 , the cathode voltage source 22 or a grid voltage source 24 applies the electric potential to the lower portion of the high-resistance film 20 which is different from the reference potential in another embodiment. In this case, it is preferable that the electric potential applied to the lower portion of the high-resistance film 20 is substantially same as that of the cathode 10 or a grid 30 . In yet another embodiment, the electron beam generating device 100 further includes a voltage source for applying electric potential, which is different from the reference potential, to the lower portion of the high-resistance film 20 .
[0033] Height of the field limiting flange 12 is substantially the same as that of the grid 30 in the electron beam irradiation direction. Moreover, it is preferable that the field limiting flange 12 is formed so that it projects into a direction of the first electrode more than the surface on which the cathode 10 and the grid 30 of the insulator 40 are provided. The field limiting flange 12 moderates change of the electric field in the vicinity of the insulator 40 , prevents concentration of equipotential lines in the vicinity of the insulator 40 , and prevents the electric discharge. The field limiting flange 12 is constructed from conductor, and electrically connects with the grid 30 , and has substantially the same electric potential as that of the grid 30 . The field limiting ring 12 electrically connects with the lower portion of the high-resistance film 20 or the second electrode 14 , and applies substantially the same electric potential as that of the grid 30 to the lower portion of the high-resistance film 20 or the second electrode 14 .
[0034] Alternatively, the insulator 40 includes a terminal for connecting the cathode 10 and the cathode voltage source 22 , and a terminal for connecting the grid 30 and the grid voltage source 24 . The terminals are filled up with high melting point wax material in order to maintain the sealing between the vacuum area 60 of the chamber 352 and a high-pressure area 50 . Alternatively, the terminals and the exposed surface of the high melting point wax material are covered with oxidation-resistant film, such as golden paste. In this case, the oxidation-resistant film is formed on the insulator 40 , and then the high-resistance film 20 is burned on the outer surface of the insulator 40 . By burning the high-resistance film 20 , the high-resistance film 20 is formed in oxidization atmosphere. Moreover, it is preferable that the melting point of the high melting point wax material is higher than the burning temperature of the high-resistance film 20 .
[0035] Operation of the electron beam exposure apparatus 300 , which has been explained in relation to FIGS. 1 and 2, will be explained hereinafter. First, the plurality of electron beam generating devices 100 generate the plurality of electron beams. The first forming member 362 forms the plurality of electron beams, which are generated by the plurality of electron beam generating devices 100 and irradiated on the first forming member 362 , by allowing them to pass through a plurality of apertures of the first forming member 362 . In alternate embodiment, a plurality of electron beams are generated by further including means for dividing an electron beam generated by the electron beam generating device 100 into a plurality of electron beams.
[0036] The first multi-axis electron lens 364 independently collects each of the plurality of electron beams, which is formed into rectangular shape, and independently adjusts focal point of each of the electron beams to the second forming member 372 . The first forming deflector 366 independently deflects the plurality of electron beams, which are formed into rectangular forms by the first forming member, so that the plurality of electron beams are irradiated on desired positions on the second forming member 372 .
[0037] The second forming deflector 368 deflects the plurality of electron beams deflected by the first forming deflector 366 in substantially perpendicular direction to the second forming member 372 , and irradiates them on the second forming member 372 . Then the second forming member 372 , which includes a plurality of apertures having rectangular forms, further forms the electron beams, which have rectangular cross-sectional forms and are irradiated on the second forming member 372 , into the electron beams having desired cross-sectional forms for irradiating them on the wafer 392 .
[0038] The second multi-axis electron lens 374 independently collects the plurality of electron beams, and independently adjusts the focal point of each of the electron beams to the blanking-electrode array 376 . Then, the plurality of electron beams, of which the focal points are adjusted by the second multi-axis electron lens 374 , respectively pass through a plurality of apertures of the blanking-electrode array 376 .
[0039] The blanking electrode array control section 338 controls whether or not the voltage is applied to the deflecting electrodes provided in the vicinity of each of the apertures of the blanking-electrode array 376 . The blanking-electrode array 376 selects whether or not each of the electron beams are irradiated on the wafer 392 based on the voltage applied to each of the deflecting electrodes.
[0040] The electron beam which is not deflected by the blanking-electrode array 376 passes through the third multi-axis electron lens 378 . Then the third multi-axis electron lens 378 reduces the diameter of the electron beam which passes through the third multi-axis electron lens 378 . The reduced electron beam passes through an aperture of the electron beam blocking member 382 . Moreover, the electron beam blocking member 382 blocks the electron beam deflected by the blanking-electrode array 376 . The electron beam which has passed through the electron beam blocking member 382 enters the fourth multi-axis electron lens 384 . Then, the fourth multi-axis electron lens 384 independently collects each of the entered electron beams, and respectively adjusts the focal point of each of the electron beams to the deflecting section 386 . The electron beam, of which the focal point is adjusted by the fourth multi-axis electron lens 384 , enters the deflecting section 386 .
[0041] The deflection control section 340 controls a plurality of deflectors of the deflecting section 386 , and independently deflects each of the electron beams, which enters the deflecting section 386 , into the position where it is to be irradiated on the wafer 392 . The fifth multi-axis electron lens 388 adjusts the focal point of each of the electron beams to the wafer 392 which passes through the fifth multi-axis electron lens 388 . Then, each of the electron beams, having the cross-sectional shape which is to be irradiated on the wafer 392 , is irradiated on a desired position of the wafer 392 , where it is to be irradiated.
[0042] During the exposure processing, it is preferable that the wafer stage drive section 398 continuously moves the wafer stage to a predetermined direction based on a direction from the wafer stage control section 342 . Then, according to the movement of the wafer 392 , a desired circuit pattern is exposed on the wafer 392 by forming the cross-sectional shape of each of the electron beams to the forms which are to be irradiated on the wafer 392 , by selecting the apertures, which allow the passage of the electron beams which are to be irradiated on the wafer 392 , and by deflecting each of the electron beams so that it is irradiated on the desired position of the wafer 392 .
[0043] In the electron beam exposure apparatus 300 explained in relation to FIGS. 1 and 2, while each of the plurality of electron beam generating devices 100 includes the insulator 40 respectively, in another embodiment, the plurality of electron beam generating devices 100 share one insulator 40 . That is, the electron beam exposure apparatus 300 includes an electron beam generating device 100 having: a plurality of cathodes 10 for generating thermal electrons; a cathode voltage source unit 22 for applying negative voltage to the plurality of cathodes 10 so that the thermal electrons are emitted from the cathodes 10 ; a plurality of grids 30 , which correspond to the plurality of cathodes 10 respectively, for collecting the thermal electrons emitted from the plurality of cathodes 10 respectively and for forming the plurality of electron beams; the grid voltage source unit 24 for applying negative voltage to the plurality of grids 30 , where the potential of each the plurality of grids 30 is lower than the potential of the corresponding cathode 10 ; and an insulator 40 for insulating the cathode voltage source unit 22 and the grid voltage source unit 24 from the thermal electrons generated by the plurality of cathodes 10 . Moreover, in the present embodiment, while the electron beam exposure apparatus 300 includes the plurality of electron beam generating devices 100 , the electron beam exposure apparatus 300 includes one electron beam generating device 100 in another embodiment.
[0044] As described above, according to the present invention, electric discharge is prevented and the current of the electron beam is controlled accurately by the electron beam generating device 100 . Moreover, by preventing electric discharge, exhaustion of the cathode is decreased and the service life of the electron beam generating device 100 is extended.
[0045] Although the present invention has been described by way of an exemplary embodiment, it should be understood that those skilled in the art might make many changes and substitutions without departing from the spirit and the scope of the present invention. It is obvious from the definition of the appended claims that embodiments with such modifications also belong to the scope of the present invention.
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An electron beam generating device, wherein a high-resistance film is formed on the outer surface of an insulator provided with a cathode for emitting thermal electrons and a grid for collecting thermal electrons and forming an electron beam to allow a feeble current to flow to the high-resistance film, thereby preventing the accumulation of thermal electrons on the insulator and discharging. The upper portion of the high-resistance film connected to a chamber supplies an approximate reference potential to the upper portion of the film, and the lower portion of the high-resistance film connected to the grid supplies almost the same potential as that of the grid to the lower portion of the film to allow a feeble current to flow to the film. The prevention of accumulation of thermal electrons on the insulator can prevent discharging, accurately control the current capacity of an electron beam, and give the electron beam generating device a longer service life.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to a scroll fluid machine comprising compressing and expanding sections and especially to a scroll fluid machine used to feed air into and discharge it from a fuel cell.
[0002] In a fuel cell, there is electrolyte between an anode and a cathode, and hydrogen is fed as cathode active material to the cathode. Hydrogen from which electrons are taken away at the cathode becomes hydrogen ions which move to the anode through the electrolyte. Oxygen is fed as anode active material to the anode and receives electrons from the cathode through an external circuit to allow the hydrogen ions to react with oxygen to form water. Hence electrons flow from the cathode to the anode or an electric current flows from the anode to the cathode. Generally oxygen-containing air is fed to the anode, so that unreactive oxygen and nitrogen as main component of air exist on the anode in addition to water.
[0003] Combination of hydrogen and oxygen is exothermic reaction and its temperature rises from supplied air. The gas which contains nitrogen as main component should be discharged from the anode.
[0004] Air pressurized by a compressor is fed to the anode, and the gas at the anode has higher pressure than atmospheric pressure. If the gas is released to air, it will become loss without doing work. Energy of the gas is retrieved through an expander. Thus, the fuel cell may preferably have a compressor and an expander.
[0005] U.S. Pat. No. 6,506,512 BI to Mon et al. discloses a compression regenerative machine for a fuel cell as fluid machine having a compressor and an expander. The scroll fluid machine has an orbiting scroll each side of which has a scroll wrap, one scroll wrap compressing sucked fluid, while the other expands sucked fluid to do work.
[0006] In the compression regenerating machine, fluid expanded and fallen in temperature in an expanding section cools an orbiting scroll from the expanding section, and fluid is expanded from the center to the circumference. However, there is no expanded or cooled fluid at the center, and no consideration is paid on cooling a bearing for an eccentric pin, a journal bearing for a driving shaft at the center of the orbiting scroll or an electric motor for driving a driving shaft.
[0007] Thus, in a small space such as an automobile engine room isolated from outside, surrounding temperature rises to lead poor heat radiation for a long time operation to raise temperature of the bearing thereby decreasing it life. Thermal expansion results in contacting the stationary scroll with the orbiting scroll to damage them. The electric motor heated during rotation for the driving shaft decreases its life.
[0008] In view of the foregoing disadvantages, it is an object to provide a scroll fluid machine having a compressing section and an expanding section at both sides of an orbiting scroll end plate, fluid which is fallen in temperature with expansion in the expanding section being applied to cool an orbiting scroll, a bearing or a driving machine effectively.
[0009] The foregoing and other features and advantages of the invention will become more apparent from the following description with respect to embodiments as shown in appended drawings.
SUMMARY OF THE INVENTION
[0010] The present invention is a scroll fluid machine having a driving shaft with an eccentric portion at one end, an orbiting scroll with an orbiting end plate that has front and rear scroll wraps, a front stationary scroll comprising a front stationary end plate with a front stationary wrap, and a rear stationary scroll having a rear stationary end plate with a rear stationary wrap. An electric motor drives the drive shaft behind the rear stationary end plate. The orbiting scroll is driven by the drive shaft and revolves with respect to the front and rear stationary scrolls to create front compressing and rear expanding sections while the front and rear orbiting scroll wraps are engaged with the front and rear stationary scroll wraps respectively. Fluid expanded and cooled in the expanding section is used to partially cool the scroll fluid machine.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a vertical sectional view of the first embodiment of a scroll fluid machine according to the present invention;
[0012] FIG. 2 is a vertical sectional view taken along the line II-II in FIG. 1 , removing an auxiliary crank shaft and a bearing therefor;
[0013] FIG. 3 is a vertical sectional view taken along the line III-III in FIG. 1 ;
[0014] FIG. 4 is a vertical sectional view of the second embodiment of a scroll fluid machine according to the present invention;
[0015] FIG. 5 is a vertical sectional view of the third embodiment of a scroll fluid machine according to the present invention;
[0016] FIG. 6 is a vertical sectional view of the fourth embodiment of a scroll fluid machine according to the present invention;
[0017] FIG. 7 is a flowchart of a piping structure of a fuel cell in which the scroll fluid machine in FIG. I is applied;
[0018] FIG. 8 is a vertical sectional view of the fifth embodiment of a scroll fluid machine according to the present invention;
[0019] FIG. 9 is a vertical sectional view of the sixth embodiment of a scroll fluid machine according to the present invention; and
[0020] FIG. 10 is a vertical sectional view of the seventh embodiment of a scroll fluid machine according to the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0021] FIG. 1 illustrates one embodiment of a scroll fluid machine according to the present invention, comprising a scroll portion 10 and an electric motor 20 . A front orbiting scroll wrap 1 a and a rear orbiting scroll wrap 1 c are provided on both sides of an orbiting end plate 1 b of an orbiting scroll 1 . On a stationary end plate 2 b of a front stationary scroll 2 , there are provided a front stationary scroll wrap 2 a engaged with the front orbiting scroll wrap 1 a , and an annular partition wall 2 c . The rear stationary scroll 3 has an outer peripheral wall 3 d and a stationary end plate 3 b on which a rear stationary scroll wrap 3 a engaged with the rear orbiting scroll wrap 1 c is provided. The outer peripheral wall 3 d is fixed to the stationary end plate 2 b of the front stationary scroll 2 . The front stationary and orbiting scroll wraps 2 a , 1 a constitute a compressing section, and the rear stationary and orbiting scroll wraps 3 a , 1 c constitute an expanding section. The compressing and expanding sections are partitioned by the annular partition wall 2 c of the front stationary scroll end plate 2 b .
[0022] An electric motor 20 is fixed to the rear stationary scroll end plate 3 b by a bolt 26 . A driving shaft 21 of the electric motor 20 is supported at journals 21 a , 21 b by rear stationary scroll end plate 3 b and a rear cover 25 via bearings 22 , 23 . A seal 12 seals the electric motor at the center of the compressing section of the scroll portion.
[0023] An eccentric portion 21 c at the front end of the driving shaft 21 is supported by a bearing 4 in a boss 1 d at the center of the rear surface of the orbiting scroll.
[0024] At the outer circumference of the orbiting scroll 1 , three bosses 1 e are projected at three vertexes of an equilateral triangle. An eccentric pin 5 b of an auxiliary crank 5 is supported by the boss 1 e via a bearing 6 b . A journal 5 a of the auxiliary crank 5 is rotatably supported via a bearing 6 a by a boss 2 e on the outer circumference of the front stationary scroll end plate. These prevent the orbiting scroll from rotating on its own axis.
[0025] Eccentricity of the driving shaft 21 with respect to an axis of the eccentric portion 21 c is equal to that of the auxiliary crank eccentric pin 5 b with respect to an axis of the journal 5 a . Thus, when the driving shaft 21 rotates, the orbiting scroll 1 revolves around the axis of the driving shaft 21 . The revolving mechanism may be a known Oldham coupling.
[0026] Numerals 21 d , 5 c are elastic rings. When an inner ball of the bearing is loosened from the eccentric pin so as to enable the bearing 4 of the orbiting scroll to insert into the eccentric portion 21 c , the elastic ring 21 d prevents corrosion owing to rotation of the inner ball to the pin. For example, when an elastic ring such as rigid rubber is fitted in a groove of the eccentric pin, the elastic material reduces resistance during fitting of the inner ball, but its friction prevents the inner ball from rotating on the eccentric pin.
[0027] The elastic ring 28 enables the eccentric pin 5 b of the auxiliary crank 5 to insert into the bearing 6 b of the orbiting scroll 1 and prevents the inner ball of the bearing 6 a from sliding.
[0028] In FIG. 2 , an inlet 7 of the compressing section is formed on the stationary end plate 2 b of the front stationary scroll 2 between the annular partition wall 2 c and the outer circumference of the scroll wrap, and an outlet 8 is formed at the center, and pipes 7 a and 8 a are connected thereto. Fluid sucked into the inlet 7 is compressed towards the center by revolution of the orbiting scroll and discharged from the outlet 8 .
[0029] In FIG. 3 , an inlet 9 for the compressing section is formed in the outermost portion of the rear stationary scroll 3 and communicates with an opening 9 b via a radial path 9 a of the rear stationary scroll end plate 3 b . A pipe 9 a is connected to the opening 9 b . Fluid which comes towards the center of the compressing section from the opening 9 b is expanded outward with revolution of the orbiting scroll; introduced to the electric motor through an inner outlet 11 of the rear stationary scroll end plate; and discharged to the outside from an outlet 27 after cooling armatures etc.
[0030] A sucking port and a discharge port of the compressing section and the inlet of the expanding section open on the front side of the scroll fluid machine thereby omitting the necessity of protruding conduits from the outer circumference of the scroll fluid machine 10 to avoid increase in the external diameter of the scroll fluid machine 10 . It is advantageous when the scroll fluid machine is installed in automobiles that are strictly limited in space.
[0031] In FIGS. 1 to 3 , the sucking port, discharge port and outlet are circular, but may be any shapes for obtaining a desired sectional area. The sucking port, discharge port and outlet are all on the front side of the stationary scroll end plate thereby decreasing the external diameter of the scroll fluid machine and arranging piping structure orderly to provide good appearance. If required, a cooling fin may be provided on the stationary scroll.
[0032] FIG. 4 is a vertical sectional view of the second embodiment of the present invention. The same numerals are allotted to the same members as those in FIG. 1 or omitted.
[0033] In this embodiment, an annular partition wall 3 c is provided on a stationary end plate 3 b of a rear stationary scroll 3 , so that a compressing section is partitioned from outer circumferential spaces of an orbiting scroll. In an orbiting scroll end plate 1 b , there is formed a cooling path 101 which has a feeding port 101 a between an outermost scroll wrap and the annular partition wall 3 c , and a discharge port 101 b outside the partition wall 3 c .
[0034] Fluid which flows from an inlet 9 b of a rear stationary end plate is expanded with revolution of the orbiting scroll; introduced into the cooling path 101 from the feeding port 101 a to cool the orbiting scroll; forwarded from the discharge port 101 b into an outer circumferential space 13 partitioned by the partition wall 2 c of the front stationary scroll and the partition wall 3 c of the rear stationary scroll end plate 3 b ; and discharged to the outside from the outlet 102 of the rear stationary scroll end plate 3 b .
[0035] The outlet may be formed on the front stationary scroll end plate.
[0036] The shape and number of the cooling path 101 may be determined to cool the orbiting scroll uniformly. For example, the cooling path may be a disc-like space as shown.
[0037] FIG. 5 is a vertical sectional view of the third embodiment of the present invention. The same numerals are allotted to the same members as those in FIG. 1 or omitted.
[0038] In this embodiment, there is no annular partition wall on a rear stationary scroll in FIG. 4 . Fluid expanded in an expanding section flows into a cooling path 101 through feeding ports 101 a , 101 a , passes through a through-hole 104 of a driving shaft 21 of an electric motor from a central inlet 103 to cool the inner side of a bearing and is discharged to the outside.
[0039] The shape and number of the cooling path 101 may be determined to cool the orbiting scroll uniformly. For example, the cooling path may be a disc-like shape as shown.
[0040] FIG. 6 is a vertical sectional view of the fourth embodiment of the present invention. The same numerals are allotted to the same members as those in FIG. 1 , or omitted.
[0041] In this embodiment, a through-hole 104 of the driving shaft 21 of an electric motor communicates with the inside of the electric motor via a bore 105 , so that at least part of fluid in the through-hole 104 flows into the inside of the electric motor to cool armatures and is discharged to the outside from an outlet 27 .
[0042] The shape and number of the cooling path are determined to cool an orbiting scroll uniformly. For example, the cooling path may be a disc-like shape as shown.
[0043] FIG. 7 schematically shows a flowchart of a piping structure when the scroll fluid machine in FIG. 1 is used as a fuel cell. Air cleaned by an air filter 31 is sucked into a scroll fluid machine 10 via a pipe 7 a , compressed in a compressing section of the scroll fluid machine 10 and pressedly forwarded to an anode of a fuel cell 32 via a pipe 8 a . On the anode of the fuel cell, oxygen in compressed air is allowed to react with hydrogen ions moved in an electrolyte layer from a cathode to form H 2 O. A gas discharged from the fuel cell 32 is a compressed gas which contains nitrogen as main component and water.
[0044] The reaction of hydrogen with oxygen to produce H 2 O is an exothermic reaction. Hence, the gas discharged from the fuel cell has higher temperature than supplied air, but has lower pressure by resistance of flow. Supplied air and discharged gas are cooled on the way of the pipe if necessary.
[0045] The water content in the discharged gas is removed by a dehumidifier (not shown) and forwarded into the outer circumferential space of the rear fixed stationary end plate in the scroll fluid machine 10 via a pipe 9 a . The compressed gas from which the water content is removed flows into the center of the expanding section through the path in the rear stationary scroll end plate. As shown in FIG. 1 , the gas is adiabatically expanded in the expanding section, so that temperature falls. The gas is introduced into the electric motor and discharged from the electric motor to the outside after cooling.
[0046] The compressed gas made expansion to apply torque to the orbiting scroll when it is adiabatically expanded in the expanding section, and the torque acts to assist compression in the compressing section, so that compressing work in the compressing section is partially retrieved. The scroll fluid machine in the embodiments in FIGS. 4 to 6 may be applied to a fuel cell as well.
[0047] FIG. 8 shows the fifth embodiment of the present invention. An expanding section communicates via an outer outlet 30 with an circumferential path 31 formed between an inner circumferential wall 32 and an outer circumferential wall 33 around an electric motor 20 . The electric motor 20 is cooled by fluid that flows through the circumferential path 31 . Noise leaks through a discharge bore 27 from the electric motor, but the outer circumferential wall 33 prevent noise from leaking to outside.
[0048] FIG. 9 shows the sixth embodiment of the present invention. An outer circumferential wall 33 ′ gradually increases in external diameter rearward, so that a sectional area of a circumferential path 31 ′ gradually increases. Fluid from the expanding section through the outer outlet 30 is depressurized and cooled. Fluid through the circumferential path 31 ′ effectively cools an electric motor 20 and its parts.
[0049] FIG. 10 shows the seventh embodiment of the present invention. Fluid flows from an expanding section into a spiral path 34 formed by a spiral wall 35 between an inner circumferential wall 32 and an outer circumferential wall 33 , through an outer outlet 30 . A pitch of the spiral wall 35 gradually increases rearward, and fluid from the expanding section is depressurized and cooled. Fluid cools an electric motor 20 and its parts. Noise of the electric motor 20 is prevented by the outer circumferential wall 33 .
[0050] The foregoing merely relates to embodiments of the invention. Various changes and modifications may be made by a person skilled in the art without departing from the scope of claims wherein:
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A scroll fluid machine comprises an orbiting scroll and front and rear stationary scrolls. The orbiting scroll is driven by a driving shaft via an eccentric portion and has front and rear orbiting scroll wraps. The front and rear stationary scroll have front and rear orbiting scroll wraps respectively. The orbiting scroll is revolved by the driving shaft with respect to the stationary scrolls while the front and rear orbiting scroll wraps are engaged with the front and rear stationary scroll wraps to create front compressing and rear expanding sections. Fluid expanded and cooled in the expanding section is used for cooling parts of the machine.
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FIELD OF THE INVENTION
The invention relates to a refrigerator cabinet appliance, the liner wall of which is resistant to attack by Freon and Freon substitutes.
BACKGROUND OF THE INVENTION
Typical refrigerator appliance cabinets consist of an outer metal cabinet, an inner plastic liner, typically ABS (acrylonitrile-butadiene styrene) or HIPS (high impact polystyrene), and an insulating foam core, typically polyurethane foam. Blowing agents for the polyurethane foam are locked into the foam. Freon, a completely halogenated methane, fluorotrichloro methane, is presently employed commercially as the blowing agent. For environmental reasons, implemented by regulations, substitutes for Freon must be found. Proposed substitutes for Freon are halogenated hydrocarbons which contain at least one hydrogen atom.
Polyurethane blowing agents, such as Freon (CFC-11) and Freon substitutes, such as 2-fluoro-2,2 dichloroethane and 2,2-dichloro-1, 1,1-trifluoroethane,(HCFC 141b and HCFC 123, respectively), can cause liner blistering, catastrophic cracks, tiny cracks (crazing) and loss of impact properties (embrittlement), as well as stress whitening and/or dissolution. The blowing agents HCFC 141b and HCFC 123 appear to be more chemically aggressive than Freon (CFC-11) in attacking the liner. It is the common belief that blowing agent attack of the liner occurs on condensation of the blowing agent to liquid, which occurs on cooling. Cooling and condensation of the blowing agent does occur during shipping and storage. Shipping conditions are simulated during fabrication by cycling the appliance cabinet from hot to cold to cause evaporation and condensation of the blowing agent(s).
It is proposed to provide a plastic sheet structure to be thermoformed into a refrigeration liner that is resistant to chemical attack.
It is an object of the invention to provide a refrigeration appliance liner to be fabricated from a thermoformable, plastic sheet material exhibiting resistance to chemical attack (blistering, cracking, crazing, as mentioned above, by polyurethane foam blown with Freon (CFC-11) or potential Freon substitutes including HCFC-123 and HCFC-141b, which are mentioned above.
It is an object of the invention to provide a refrigeration appliance liner to be fabricated from a thermoformable, plastic sheet material which retains a high level of toughness (impact properties) and strength (tensile properties), even at low temperatures (at 5° F. or less).
It is another object of the invention to provide a liner made from a plastic sheet material that maintains processability similar to HIPS or ABS, including favorable extrusion conditions and similar thermoforming behavior.
It is another object of the invention to provide a liner made from a plastic sheet containing a layer of a special multi-functional blend that exhibits excellent chemical resistance to Freon or potential Freon substitutes, may additionally function as an adhesive layer between optional layers of HIPS (or ABS) and polyolefin, and finally acts as a compatibilizing agent when regrind plastic sheet scrap is recycled to virgin plastics resin being extruded into the core sheet layer.
SUMMARY OF THE INVENTION
In accordance with the invention, a refrigerator appliance is provided with a plastic liner which is substantially chemically inert to Freon and Freon substitutes. A conventional refrigerator appliance cabinet includes an outer metal cabinet, an inner plastic liner comprising ABS (acrylonitrile-butadiene styrene) or HIPS (high impact polystyrene), and an insulating foam core, typically polyurethane foam. Blowing agent for the polyurethane foam is locked into the foam.
The plastic liner serves as the inner plastic wall of the refrigerator. The plastic wall is of variable thickness, as a result of thermoforming during fabrication. However, it is formed of a composite of relatively uniform thickness.
In accordance with the invention, the plastic liner comprises a barrier layer, which is substantially chemically inert to completely halogenated and partially halogenated hydrocarbons, e.g., chlorinated and/or fluorinated hydrocarbons used as blowing agents for polyurethane foam formation. In one embodiment of the invention, a core layer of ABS (acrylonitrile-butadiene-styrene) or HIPS (high impact polystyrene), for example by coextrusion or lamination, is affixed to the barrier layer. For visual attractiveness, a glossy patina on the barrier layer or the core layer may be present either due to the inherent properties of the core layer or by providing an independent layer of material which provides high gloss.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic drawing of a refrigerator cabinet.
FIG. 2 is a schematic drawing of the plastic liner serving as plastic wall of the refrigerator.
FIG. 3 is a fragmentary cross section of the composite forming the plastic liner.
DETAILED DESCRIPTION OF THE INVENTION
The invention will be explained with reference to the appended drawings.
The refrigerator appliance, of FIG. 1, includes a cabinet and is defined by an outer cabinet metal wall 1, and inner liner wall 2, and a body of foamed-in-place insulation 3 there between. In one popular design, the cabinet may define a freezer space 4 and an above-freezing refrigeration space 5.
Inner liner wall 2 is thermoformed into the desired configuration, as shown in FIG. 2. Inner liner wall 2 is a thermoformed product of liner sheet 6, one embodiment of which is illustrated in FIG. 3 as a multi lamina composite. After being thermoformed into the desired configuration, the inner liner wall 2 is disposed into the outer cabinet wall 1 in a nested, spaced relationship for introduction of the foamed insulation by a conventional foaming in place operation. Usually the outer cabinet wall 1 and the inner liner wall 2 are joined physically by mating of joints.
The barrier layer of the invention is substantially chemically inert to halogenated hydrocarbon(s) used as blowing agents in polyurethane foam production. If a core layer is employed, it is disposed on a surface of the core layer. During polyurethane in situ foam production, in one embodiment of the invention, it is the surface of the barrier layer of the composite which is contiguous to and bonds with the foam. However, it is not essential that the barrier layer of the invention be contiguous to the foam. In FIG. 3 the barrier layer is illustrated as numeral 8.
The barrier layer comprises 4 to 50% by weight of a composite which includes a core layer and comprises polymers or copolymers of ethylene or propylene which are selected from the group consisting of polypropylene, low density polyethylene, linear low density polyethylene, high density polyethylene (melt index of 1 to 10 and density of 0.935 to 0.960), high molecular weight high density polyethylene (melt index of 0.05 to 1.0), ethylene vinyl alcohol, certain high impact polystyrenes, nylon 66, and PVC. The barrier layer may comprise one or more lamina of the same or different polymer or copolymer.
The barrier layer may, and preferably does, contain 4 to 30 weight percent of synthetic block copolymer rubber. The synthetic block copolymer rubber can be selected from styrene-butadiene diblock; styrene-ethylene/butylene-styrene triblock; styrene-ethylene/butylene-styrene triblock functionalized with maleic anhydride, maleic acid or admixtures thereof, or combinations of any of the above.
The liner sheet may be formed of ABS (acrylonitrile-butadiene-styrene) or HIPS (high impact polystyrene) core layer which constitutes the major proportion of the composite. The core layer comprises 50 to 96 weight percent of the composite. Those core materials are chemically degradable by the completely or partially halogenated hydrocarbon blowing agent, used in the polyurethane foam production. Both of these core materials are commercially available. In FIG. 3 the core layer, chemically degradable by the fluorinated hydrocarbon, is designated as 7.
The core layer which is (1) high impact polystyrene or (2) acrylonitrile-butadiene-styrene copolymer, contains 5 to 35, preferably 5 to 20, and usually 5 to 15 weight percent rubber in the form of particles. The rubber is usually polybutadiene and can be a styrene-butadiene copolymer. The rubber particles can have average diameters of at least 5 microns, and generally of at least 6 microns average diameters and up to 10 microns. When the rubber particles are 1 micron or less, as described in U.S. Pat. No. 4,513,120 high gloss polystyrene (medium impact) is produced. U.S. Pat. No. 4,513,120 is incorporated by reference herein.
Various alternatives are available for maximizing the adhesion of the core material to the barrier layer. Moreover, these alternatives can improve adhesion of the foam insulation to the barrier material. The core layer may be subjected to corona discharge treatment, or to ultraviolet light exposure, and by methods known in the art. In accordance with one embodiment of the invention, maximizing the adhesion of the the barrier layer to the foam and optionally to a core layer appears to be achieved chemically. In a preferred embodiment the material of the barrier layer contains maleic anhydride, maleic acid, and/or derivatives of maleic acid in an amount ranging from 0.1 to 10 weight percent of the barrier material. Conveniently, this can be achieved by inclusion of styrene-ethylene/butylene-styrene triblock functionalized with maleic anhydride, maleic acid or admixtures thereof; the triblock material is available from Shell Chemical Company as Kraton FG-1901X.
In one embodiment of the invention, the composite is formed with a barrier layer disposed on one surface of the core layer with a third layer of medium impact high gloss polystyrene on the exposed surface of the core layer. The third layer of medium impact high gloss polystyrene comprises 0.5 to 8 weight percent of the composite. The third layer is depicted in FIG. 3 as element 9.
The composite is formed by the coextrusion of the materials of the laminae described above. The composite sheet can then be cut into suitable lengths for thermoforming into any desired configuration, one of which is illustrated by FIG. 2. The resulting liner wall 2 is then assembled with the outer cabinet wall 1 and in situ foaming of the insulation material is performed. The resulting structure exhibits impact strength, and substantial elimination of thermal cracking and of blistering.
In situ foaming involves admixing an isocyanate with a masterbatch. The masterbatch comprises 60 to 70 percent of a polyol; 0.3 to 1.5 percent of a surfactant; 0.5 to 3.0 percent of a catalyst 0.4 to 2.5 percent of water and 12 to 30 percent of the blowing agent. The isocyanates used in applicances include TDI and PMDI. TDI comprises an 80:20 mixture of 2,4 and 2,6 isomers of products produced by dinitration of toluene, catalytic hydrogenation to the diamines, and phosgenation. Cf. Kirk Othmer, ENCYCLOPEDIA OF CHEMICAL TECHNOLOGY, Vol. 23, page 581 (Third Edition). PMDI is the reaction product formed by nitration of benzene and reduction to produce aniline; reacting aniline with formaldehyde in the presence of hydrochloric acid to produce a mixture of oligomeric amines, which are phosgenated to yield PMDI. Cf. Kirk Othmer, ENCYCLOPEDIA OF CHEMICAL TECHNOLOGY, Vol. 23, page 581 (Third Edition). The blowing agent can be Freon or Freon substitutes which are partially halogenated lower hydrocarbon of 1 to 5 carbon atoms, usually of 2 to 4 carbon atoms; halogenated includes fluorinated and/or chlorinated. By "partially halogenated" is meant that the Freon substitutes of the invention preferably contains at least one hydrogen atom. Illustrative of the partially halogenated lower hydrocarbon are 1,1-dichloro-1-fluoroethane and 2,2-dichloro-1,1,1-trifluoroethane, chlorodifluoromethane (HCFC 22); 1,1,1,2-tetrafluoro-2-chloro-ethane (HCFC 124); 1,1,1,2-tetrafluoroethane (HFC 134a) and pentafluoroethane (HFC 125). The foams produced contain in their cellular structure residual amounts of the blowing agent. The foam is formed in situ by foaming in a high pressure mixhead equipped to a nozzle for introducing the foam and foaming components into the cavity formed by the nesting of outer metal cabinet 1 and the plastic liner.
EXAMPLES
Examples 1
Plastic sheets of composition described in the Table 1 were fabricated into test plaques (15"×15"×0.050") and Brett-type test panels (783/4"×7 7/8"×0.050"). These test sheets were then positioned as pairs into closed foaming jigs with a 2" space between the sheets. Polyurethane foam chemicals were then introduced into the jigs to fill the space between the plastic sheets, to produce plastic/foam/plastic composite structures. These composite structures were thermally cycled several times between -20° F. and 140° F., to cause condensation and vaporization of liquid blowing agent along the exposed plastic sheet surfaces.
Several blowing agents (CFC-11, and HCFC-123,) at several levels (9-15%) were evaluated in separate tests. CFC-11 is trichlorofluoromethane (CCl 3 F): HCFC-123 is 2,2dichloro-1,1,1,-trifluoroethane, HCFC-141b is 1,1-dichloro-1-fluroethane (CHCl 2 CF 3 );
The thermally cycled composite structures were then tested, as summarized in Table 1, and inspected for signs of chemical attack.
TABLE 1__________________________________________________________________________POLYSTYRENE/POLYOLEFIN BLENDSMIS-ESCR AND PHYSICAL PROPERTIES__________________________________________________________________________ MOBIL PS7100 BLEND 1 BLEND 2 BLEND 3 BLEND 4 BLEND 5 BLEND__________________________________________________________________________ 6Composition (%)HIPS/PS, % 100 80 80 80 80 80 80Polyolefin, % 0 10 10 10 10 10 10Compatibilizer, % 0 10 10 10 10 10 10HIPS/PS, Type 7100 7100 7100 7100 7100 7100Polyolefin, Type Hilmont Aristech Himont Mobil Mobil Himont 6231 FF-028N SA-747M HMA-045 MMA-169 SA-747MCompatibilizer, Type Homo PP Homo PP Rand PP HDPE LLDPE Rand PP G1657 G1657 G1657 G1657 G1657 50:50 S-EB-S S-EB-S S-EB-S S-EB-S S-EB-S 1657:1901MIS-ESCR, 1000 psi (min)Chiffon 63 138 394 125 63 2 600COOA 115 441 1186 491 256 4 5963CFC-11 9 7 9 8 6 0 12HCFC-123 5 4 14 10 2 0 14HCFC-141b 6 8 13 10 6 0 17MIS-ESCR, 400 psi (min)CFC-11 22 37HCFC-123 13 65HCFC-141b 23 51Physical Properties:MFI (G), g/10 min 2.9 9.3 6.8 8.2 8.7 12.1 5.8Vicat, C 103 103 103 101 100 92 101Tensile Yield, psi 2500 2200 2500 2100 2100 1600 2600Tensile Fail, psi 3500 2200 2500 2100 2100 1600 2600Tensile Modulus, psi 182,000 97,000 109,000 99,000 96,000 58,000 112,000Elongation, % 41 31 41 31 29 28 40Izod Impact, ft.lb/in 2.1C 1.0C 1.4C 1.2C 1.1C 1.1C 1.5CGardner Impact, in.lb 123 49 95 69 18 6 93__________________________________________________________________________ BLEND 7 BLEND 8 BLEND 9 BLEND 10 BLEND 11 BLEND__________________________________________________________________________ 12Composition (%)HIPS/PS, % 80 85 80 80 70 60Polyolefin, % 10 10 10 10 20 30Compatibilizer, % 10 10 10 10 10 10HIPS/PS, Type 7100 7100 7100 7100 7100 7100Polyolefin, Type Himont Hilmont Himont OxyChem OxyChem OxyChem SA-747M SA-747M SA-747M L5005 L5005 L5005 Rand PP Rand PP Rand PP HMW-HDPE HMW-HDPE HMW-HDPECompatibilizer, Type FG1901X G1702 G1702 FG1901X FG1901X FG1901X SEBS/MA S-EP S-EP SEBS/MA SEBS/MA SEBS/MAMIS-ESCR, 1000 psi (min)Chiffon 630 147 90 342 753 1700COOA 1708 7026 4995CFC-11 14 7 5 8 13 25HCFC-123 20 4 3HCFC-141b 18 5 4MIS-ESCR, 400 psi (min)CFC-11 44 41 48 80HCFC-123 69 56 74 142HCFC-141b 60 48 63 115Physical Properties:MFI (G), g/10 min 5.7 2.8 2.7 3.5 2.9 2.2Vicat, C 101 101 101 100 101 102Tensile Yield, psi 2800 2400 2400 3000 3070 3020Tensile Fail, psi 2800 2400 2400 3000 3070 3020Tensile Modulus, psi 116,000 152,000 145,000 138,000 130,000 124,000Elongation, % 40 12 7 50 46 36Izod Impact, ft.lb/in 1.6H 2.1C 2.1C 2.1C 2.0C 1.8CGardner Impact, in.lb 99 66 66 121 127 109__________________________________________________________________________ BLEND 13 BLEND 14 BLEND 15 BLEND 16 BLEND 17 BLEND__________________________________________________________________________ 18Composition (%)HIPS/PS, % 50 60 60 60 60 60Polyolefin, % 40 30 30 30 30 30Compatibilizer, % 10 10 10 10 10 10HIPS/PS, Type 7100 7100 7100 7100 7100 7100Polyolefin, Type OxyChem OxyChem Himont Himont Chevron Chevron L5005 L5005 SA-747M SA-747M PE5280T PE5280T HMW-HDPE HMW-HDPE Rand PP Rand PP PE/EVA 8% PE/EVA 8%Compatibilizer, Type FG1901X G1657 G1657 FG1901X FG1901X G1657 SEBS/MA S-EB-S S-EB-S SEBS/MA SEBS/MA S-EB-SMIS-ESCR, 1000 psi (min)Chiffon 2887 37 22 914 >10000COOA (400 psi)CFC-11 31 3 4 16HCFC-123HCFC-141bMIS-ESCR, 400 psi (min)CFC-11 130 51 48 88 75 68HCFC-123 270 93 146 230 150 160HCFC-141b 218 73 88 159 105 103Physical Properties:MFI (G), g/10 min 1.8 3.6 11.1 6.3 4.6 6.1Vicat, C 103 99 101 103 88 77Tensile Yield, psi 2940 2500 2200 2790 2520 2000Tensile Fail, psi 2940 2500 2040 2770 2520 2000Tensile Modulus, psi 118,000 106,000 79,000 101,000 84,000 65,000Elongation, % 33 34 39 36 54 42Izod Impact, ft.lb/in 1.5H 1.4C 1.0C 1.4C 2.6H 2.1HGardner Impact, in.lb 55 100 136 154 242 215__________________________________________________________________________ BLEND 19 BLEND 20 BLEND 21 BLEND 22 BLEND 23 BLEND__________________________________________________________________________ 24Composition (%)HIPS/PS, % 60 50 50 40 40 60Polyolefin, % 30 40 40 50 50 30Compatibilizer, % 10 10 10 10 10 10HIPS/PS, Type 7100 9524 7800 7800 1800 1800Polyolefin, Type Chevron OxyChem OxyChem OxyChem OxyChem Mobil PE5272 L5005 L5005 L5005 L5005 HYA-301 PE/EVA 4% HMW-HDPE HMW-HDPE HMW-HDPE HMW-HDPE HDPECompatibilizer, Type G1657 G1657 G1657 FG1901X FG1901X FG1901X S-EB-S S-EB-S S-EB-S SEBS/MA SEBS/MA SEBS/MAMIS-ESCR, 1000 psi (min)Chiffon >1000 >1000 >1000 >1000 223COOA (400 psi) (400 psi)CFC-11HCFC-123HCFC-141bMIS-ESCR, 400 psi (min)CFC-11 53 96 88 311 346 62HCFC-123 126 197 170 642 627 76HCFC-141b 74 135 108 >1000 495 87Physical Properties:MFI (G), g/10 min 7.7 1.9 1.7 1.8 1.6 4.7Vicat, C 103 104 104 106 109 106Tensile Yield, psi 1930 2500 2500 2790 3890 5160Tensile Fail, psi 1930 2000 2300 2830 3460 5160Tensile Modulus, psi 61,000 102,000 103,000 122,000 174,000 229,000Elongation, % 42 46 48 82 23 5Izod Impact, ft.lb/in 1.9H 1.9C 1.7C 1.7C 0.8C 1.1HGardner Impact, in.lb 240 104 89 67 14 38__________________________________________________________________________ BLEND 25 BLEND 26 BLEND 27 BLEND 28 BLEND__________________________________________________________________________ 29 Composition (%) HIPS/PS, % 60 60 50 0 20 Polyolefin, % 30 30 40 80 65 Compatibilizer, % 10 10 10 20 15 HIPS/PS, Type 1800 7800 7100 7100 7100 Polyolefin, Type Mobil OxyChem Mobil Mobil Mobil HCX-002 L5005 HMX-034 HMX-034 HMX-034 HDPE HMW-HDPE HDPE HDPE HDPE Compatibilizer, Type FG1901X FG1901X FG1901X FG1901X FG1901X SEBS/MA SEBS/MA SEBS/MA SEBS/MA SEBS/MA MIS-ESCR, 1000 psi (min) Chiffon >1000 734 >1000 >1000 >1000 COOA CFC-11 HCFC-123 HCFC-141b MIS-ESCR, 400 psi (min) CFC-11 679 83 351 >1000 >1000 HCFC-123 523 120 630 >1000 >1000 HCFC-141b 496 97 544 >1000 >1000 Physical Properties: MFI (G), g/10 min 9.4 3.7 9.3 9.8 10.8 Vicat, C 103 103 105 115 108 Tensile Yield, psi 4140 2950 2890 1830 2170 Tensile Fail, psi 4140 2950 2890 1830 2170 Tensile Modulus, psi 192,000 151,000 126,000 58,000 71,000 Elongation, % 15 121 18 500 477 Izod Impact, ft.lb/in 0.7H 4.3H 0.6C 13.8 1.4C Gardner Impact, in.lb 44 207 48 >320 294__________________________________________________________________________ *high impact polystyrene **polystyrene
Example 2
Sheets of several different compositions described in Table 2 invention were exposed to the liquid blowing agents by sealing a glass ball joint to the sheet samples and adding the specific liquid blowing agent being evaluated (CFC-11, HCFC-123, and HCFC-141b).
The samples were exposed to the blowing agents for thirty minutes each, then exposed to heat (60° C. for 30 minutes) to drive off the blowing agents, and finally inspected for chemical attack. Several sheet samples displayed no signs of chemical attack at all, and most samples showed at least some reduction in chemical attack when compared to sheets of HIPS or ABS. The results are set forth in Table 2.
TABLE 2______________________________________LIQUID BLOWING AGENT CONTACT STUDY CFC-11 HCFC-123 HCFC-141b______________________________________UNMODIFIEDRESINS:Mobil PS7100 HIPS Severe Severe Severe Blistering Blistering BlisteringMobil PS7800 MIPS Severe Severe Severe Blistering Blistering BlisteringMobil PS5350 HIPS Severe Severe Severe Blistering Blistering BlisteringDow 469 HIPS Severe Severe Severe Blistering Blistering BlisteringMonsanto ABS Unaffected Cracking Cracking Severe No Blistering BlisteringPS/POLYOLEFINBLENDS COEX.ON PS7100:CA10 (10% Ran- Severe Severe Severedom PP) Blistering Blistering BlisteringCB30 (30% Ran- Moderate Moderate Moderatedom PP) Blistering Blistering BlisteringLB40 (40% HMW- Skin Skin SkinHDPE) Delamination Delamination Delamination Moderate No Blistering No Blistering BlisteringBASF KR2773 Skin Slim Skin(30% HDPE) Delamination Delamination Delamination(10% CaCO.sub.3 No Slight Slightfilled) Blistering Blistering BlisteringBASF KR2774 Severe Moderate Moderate(30% LDPE) Blistering Blistering BlisteringBARRIER FILMSLAMINATED ONPS7100:Mobil MMA-169 Moderate Unaffected UnaffectedLLDPE (2 mil) BlisteringMobil HMA-045 Unaffected Unaffected UnaffectedHDPE (2 mil)Oxy L5005 HMW- Unaffected Unaffected UnaffectedHDPE (2 mil)DuPont EVOH Unaffected Unaffected Unaffected(5 mil)______________________________________
Example 3
The invention is illustrated by use in a top mount (freezer on top) refrigerator at 15 ft 3 capacity, with HCFC-123 as the polyurethane blowing agent at an estimated 18% level weight.
The layers of the composite are described below.
______________________________________Pre-Thermoformed Sheet:______________________________________Sheet Total Thickness 202 mil (0.202")Barrier Layer Thickness 10 mil (0.010")Core Layer Thickness 190 mil (0.190")Gloss Layer Thickness 2 mil (0.002")Barrier Layer % of 5%Total sheetPre-Thermoformed Sheet (77.75 × 46.75 ×Dimensions 0.202) inchesBarrier Layer Material*Core Layer Material Mobil ES7100 Refrigeration Grade HIPSGloss Layer Material Mobil ES7800 Medium Impact, High Gloss PS______________________________________*Barrier Material used had the following:High Density Mobil HMX-034 HDPEPolyethylene Type (Melt Flow = 4.0, Density = 0.954)Rubber Type Shell Chemical Co. Kraton FG-1901X Styrene-Ethylene/Butylene- Styrene Tri-block (functionalized with 2% maleic anhydride)withPolyethylene Level 80%,Rubber Level 20%, andIrganox 1010 Antioxidant 500 ppm
The barrier layer material was compounded in a Werner & Pfleiderer ZSK30 mm twin screw extruder, at a temperature profile which ranged from 225° to 400° F.
The composite was formed from a two-layer system including the core layer (ES7100) and the barrier layer, which were coextruded. The gloss layer of medium impact polystyrene (Mobil ES7800) was laminated thereto. The temperature profile for coextrusion is set forth below:
______________________________________Coextrusion Temperature Profile:______________________________________ES 7100 Extruder Profile (345-380-350-300-390-400)° F. Die 415° F. Melt Temp 440° F.Barrier Material Profile (275-300-325-330)° F.Extruder Die 415° F. Melt Temp 340° F.______________________________________
The thermoformed product assembled in a metal cabinet with subsequent in situ insulation formation was subjected to 12 temperature cycles ranging from -40° F. to +150° F. Polyurethane foam adhesion to the barrier layer was good and better than the adhesion of barrier layer to the core material. The liner wall exhibited satisfactory impact strength, no signs of cracking during thermal blistering and de minimis blistering.
Example 4
A 22 ft 3 refrigerator, a side-by-side model (configuration of refrigerator and freezer compartments) was fitted with a liner and then insulated with polyurethane foam produced by CFC-11 blowing agent at an estimated 16 weight % level.
The compositions, and dimensions, of the preformed sheet components are described below.
______________________________________Sheet Total Thickness 198 mil (0.198")Barrier Layer Thickness 6 mil (0.006")Glue/Compat. Layer Thickness 2 mil (0.002")Core Layer Thickness 188 mil (0.188")Gloss Layer Thickness 2 mil (0.002")Glue + Barrier Layers 5%% of sheetPre-Thermoformed Sheet (78.75 × 36.00 ×Dimensions 0.198) inchesBarrier Layer Material* Mobil HMX-034 HDPEGlue/Compatibilizer Layer** Mobil Developmental LB40Core Layer Material Mobil ES7100 Refrigeration Grade HIPSGloss Layer Material Mobil ES7800 Medium Impact, High Gloss PS______________________________________*Barrier Layer-Material used Mobil HMX-034 HDPE (High Density Polyethylene) (Melt Flow = 4.0, Density = 0.954)**Glue/Compat Layer Composition:Polyethylene Type OxyChem Alathon L5005 HMW-HDPE (Melt Flow = 0.055 Cond. F, Density = 0.95)Rubber Type Shell Chemical Co. Kraton FG-1901X Styrene-Ethylene/Butylene- Styrene Tri-block (functionalized with 2% maleic anhydride)HIPS Type Mobil ES7100 Refrigeration Grade (Melt Flow = 2.5)Polyethylene Level 40%Rubber Level 10%HIPS Level 50%
The glue/compatabilizer layer materials were compounded in a Werner Pfleiderer 30 mm twin screw extruder at a temperature profile ranging from 225° F. to 450° F. The ES7800 gloss layer was laminated to the remaining laminate which were coextruded in a Welex Coextrusion System.
The unit (s) were subjected 12 times to a temperature cycle of -40 ° to 150° F. The unit exhibited satisfactory impact strength, and de minimis blistering.
Thus it is apparent that there has been provided in accordance with the invention, a refrigerator plastic liner wall that fully satisfies the objects, aims, and advantages set forth above. While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications, and variations as fall within the spirit and broad scope of the appended claims.
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A refrigerator cabinet is provided with a plastic liner, the inside wall of the refrigerator, which is resistant to chemical degradation by fluorocarbons. Freon and Freon substitutes used as blowing agents for foaming the insulation contained between the outer metal cabinet and the inside wall of the refrigerator can cause blistering, cracking, and sometimes dissolution of materials used to form the plastic liner, which is the inside wall of the refrigerator. There is now provided a plastic liner which is resistant to those blowing agents and particularly to those blowing agents which are partially halogenated and tend to be more aggressive than Freon. The plastic liner wall maintains impact strength and toughness after exposure to fluorohydrocarbons conventionally employed in refrigerator units for in situ polyurethane foam production.
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BACKGROUND OF THE INVENTION
The formation of slimes by microorganisms is a problem that is encountered in many aqueous systems. For example, the problem is not only found in natural waters such as lagoons, lakes, ponds, etc., and confined water as in pools, but also in such industrial systems as cooling water systems, air washer systems and pulp and paper mill systems. All possess conditions which are conducive to the growth and reproduction of slime-forming microorganisms. In both once-through and recirculating cooling systems, for example, which employ large quantities of water as a cooling medium, the formation of slime by micro-organisms is an extensive and constant problem.
Airborne organisms are readily entrained in the water from cooling towers and find this warm medium an ideal environment for growth and multiplication. Aerobic and heliotropic organisms flourish on the tower proper while other organisms colonize and grow in such areas as the tower sump and the piping and passages of the cooling system. The slime formation not only aids in the deterioration of the tower structure in the case of wooden towers, but also promotes corrosion when it deposits on metal surfaces. Slime carried through the cooling system plugs and fouls lines, valves, strainers, etc., and deposits on heat exchange surfaces. In the latter case, the impedance of heat transfer can greatly reduce the efficiency of the cooling system.
In pulp and paper mill systems, slime formed by micro-organisms is commonly encountered and causes fouling, plugging, or corrosion of the system. The slime also becomes entrained in the paper produced to cause breakouts on the paper machines, which results in work stoppages and the loss of production time. The slime is also responsible for unsightly blemishes in the final product, which result in rejects and wasted output.
The previously discussed problems have resulted in the extensive utilization of biocides in cooling water and pulp and paper mill systems. Materials which have enjoyed widespread use in such applications include chlorine, chlorinated phenols, organo-bromines, and various organo-sulfur compounds. All of these compounds are generally useful for this purpose but each is attended by a variety of impediments. For example, chlorination is limited both by its specific toxicity for slime-forming organisms at economic levels and by the tendency of chlorine to react, which results in the expenditure of the chlorine before its full biocidal function is achieved. Other biocides are attended by odor problems, and hazards with respect to storage, use or handling which limit their utility. To date, no one compound or type of compound has achieved a clearly established predominance with respect to the applications discussed. Like wise, lagoons, ponds, lakes, and even pools, either used for pleasure purposes or used for industrial purposes for the disposal and storage of industrial wastes, become, during the warm weather, designed by slime due to microorganisms growth and reproduction. In the case of industrial storage or disposal of industrial materials, the microorganisms cause additional problems which must be eliminated prior to the materials use or disposal of the waste.
Naturally, economy is a major consideration with respect to all of these biocides. Such economic considerations attach to both the cost of the biocide and the expense of its application. The cost performance index of any biocide is derived from the basic cost of the material, its electiveness per unit of weight, the duration of its biocidal or biostatic effect in the system treated, and the ease and frequency of its addition to the system treated. To date, one of the commercially available biocides has exhibited a prolonged biocidal effect. Instead, their effectiveness is rapidly reduced as a result of exposure to physical conditions such as temperature, association with ingredients contained by the system toward which they exhibit an affinity or substantivity, etc., with a resultant restriction or elimination of their biocidal effectiveness, or by dilution.
As a consequence, the use of such biocides involves their continuous or frequent addition to systems to be treated and their addition to multiple points or zones in the systems to be treated. Accordingly, the cost of the biocide and the labor cost of applying it are considerable. In other instances, the difficulty of access to the zone in which slime formation is experienced precludes the effective use of a biocide. For example, if in a particular system there is no access to an area at which slime formation occurs the biocide can only be applied at a point which is upstream in the flow system. However, the physical or chemical conditions, e.g., chemical reactivity, thermal degradation, etc. which exist between the point at which the biocide may be added to the system and the point at which its biocidal effect is desired render the effective use of a biocide impossible.
Similarly, in a system experiencing relatively slow flow, such as a paper mil, if a biocide is added at the beginning of the system, its biocidal effect may be completely dissipated before it has reached all of the points at which this effect is desired or required. As a consequence, the biocide must be added at multiple points, and even then a diminishing biocidal effect will be experienced between one point of addition to the system and the next point downstream at which the biocides may be added. In addition to the increased cost of utilizing and maintaining multiple feed points, gross in economies with respect to the cost of the biocide are experienced. Specifically, at each point of addition, an excess of the biocide is added to the system in order to compensate for that portion of the biocide which will be expended in reacting with other constituents present in the system or experience physical changes which impair its biocidal activity.
SUMMARY OF THE INVENTION
The biocidal compositions of the present invention comprises, as active ingredients, 1) 2-bromo-2-nitropropane-1,3-diol (BNPD) and 2) didecyl dimethyl ammonium chloride (DDAC). These constituents are commercially available. The synergistic effect obtained by combining BNPD and DDAC has not been previously disclosed.
DETAILED DESCRIPTION OF THE INVENTION
Surprisingly, the present inventors have found that mixtures of BNPD and DDAC are especially efficacious in controlling the growth of bacterial microbes, specifically the Klebsiella pneumoniae species. This particular species is a member of the capsulated, facultative class of bacteria and is generally present in air, water and soil. These bacteria continually contaminate open cooling systems and pulping and paper-making systems and are among the most common slime formers. The slime may be viewed as being a mass of agglomerated cells stuck together by the cementing action of the gelatinous polysaccharide or proteinaceious secretions around each cell. The slimy mass entraps other debris, restricts water flow and heat transfer, and may serve as a site for corrosion.
The fact that the Klebsiella species used in the tests is a facultative species if important as, by definition, such bacteria may thrive under either aerobic or anaerobic conditions. Accordingly, by reason of demonstrated efficacy in the growth inhibition of this particular species, one can expect similar growth inhibition attributes when other aerobic or anaerobic bacterial species are encountered. It is also expected that these compositions will exhibit similar growth inhibition attributes when fungi and algae species are encountered.
In accordance with the present invention, the combined BNPD and DDAC treatment may be added to the desired aqueous system in need of biocidal treatment, in an amount of from about 0.1 to about 200 parts of the combined treatment to one million parts (by weight) of the aqueous medium. Preferably, about 5 to about 50 pars of the combined treatment per one million parts (by weight) of the aqueous medium is added.
The combined treatment is added, for example, to cooling water systems, paper and pulp mill systems, pools, ponds, lagoons, lakes, etc., to control the formation of bacterial microorganisms, which may be contained by, or which may become entrained in, the system to be treated. It has been found that the compositions and methods of utilization of the treatment are efficacious in controlling the facultative bacterium, Klebsiella pneumoniae, which may populate these systems. It is thought that the combined treatment composition and method of the present invention will also be efficacious in inhibiting and controlling all types of aerobic and anaerobic bacteria.
Surprisingly, it has been found that when the ingredients are mixed, in certain instances, the resulting mixtures possess a higher degree of bactericidal activity than that of the individual ingredients comprising the mixture. Accordingly, it is possible to produce a highly efficacious bactericide. Because of the enhanced activity of the mixture, the total quantity of the bacterial treatment may be reduced. In addition, the high degree of bactericidal effectiveness which is provided by each of the ingredients may be exploited without use of higher concentrations of each.
The following experimental data were developed. It is to be remembered that the following examples are to be regarded solely as being illustrative and not as restricting the scope of the invention.
DESCRIPTION OF PREFERRED EMBODIMENT
BNPD and DDAC were added in varying ratios and over a wide range of concentrations to a liquid nutrient medium which was substantially inoculated with a standard volume of a suspension of the facultative bacterium Klebsiella pneumoniae. Growth was measured by determining the amount of radioactivity accumulated by the cells when 14C-glucose was added as the sole source of carbon in the nutrient medium. The effect of the biocide chemicals, alone and in combination, is to reduce the rate and amount of 14C incorporation into the cells during incubation, as compared to controls not treated with the chemicals. Additions of the biocides, alone and in varying combinations and concentrations, were made according to the accepted "checkerboard" technique described by M. T. Kelley and J. M. Matsen, Antimicrobial Agents and Chemotherapy. 9:440 (1976). Following a two hour incubation, the amount of radioactivity incorporated in the cells was determined by counting (14C liquid scintillation procedures) for all treated and untreated samples. The percent reduction of each treated sample was calculated from the relationship: ##EQU1##
Plotting the % reduction of 14C level against the concentration of each biocide acting alone results in a dose-response curve, from which the biocide dose necessary to achieve any given % reduction can be interpolated.
Synergism was determined by the method of calculation described by F. C. Kull, P. C. Eisman, H. D. Sylwestrowicz and R. L. Mayer, Applied Microbiology 9,538 (1961) using the relationship: ##EQU2## where: Q a=quantity of compound A, acting alone, producing an end point
Q b=quantity of compound B, acting alone, producing an end point
Q A=quantity of compound A in mixture, producing an end point
Q B=quantity of compound B in mixture, producing an end point
The end point used in the calculation is the % reduction caused by each mixture of A and B. Q A and Q B are the individual concentrations in the A/B mixture causing a given % reduction. Q a and Q b are determined by interpolation from the respective dose response curves of A and B as those concentrations of A and B acting alone which produce the same % reduction as each specific mixture produced.
Dose-response curves for each active acting alone were determined by linear regression analysis of the dose-response data. Data were fitted to a curve represented by the equation shown with each data set. After linearizing the data, the contributions of each biocide component in the biocide mixtures to the inhibition of radioisotope uptake were determined by interpolation with the dose-response curve of the respective biocide. If, for example, quantities of Q A plus Q B are sufficient to give a 50% reduction in 14C content, Q a and Q b are those quantities of A or B acting alone, respectively, found to give 50% reduction in 14C content. A synergism index (SI) is calculated for each combination of A and B.
Where the SI is less than 1, synergism exists. Where the SI=1, additivity exists. Where SI is greater than 1, antagonism exists.
The data in the following tables come from treating Klebsiella pneumoniae, a common nuisance bacterial type found in industrial cooling waters and is pulping and paper making systems, with varying ratios and concentrations of DNPD and DDAC. Shown for each combination is the % reduction of 14C content (% I), the calculated SI, and the weight ratio of BNPD and DDAC.
TABLE I______________________________________BNPD vs. DDACppm ppm RatioBNPD.sup.1 DDAC.sup.2 BNPD:DDAC % I SI______________________________________80 0 100:0 9840 0 100:0 9320 0 100:0 6710 0 100:0 33 5 0 100:0 162.5 0 100:0 11 0 10 0:100 93 0 7.5 0:100 84 0 5.0 0:100 55 0 3.75 0:100 45 0 2.50 0:100 28 0 1.25 0:100 080 10 8:1 99 2.1280 7.5 10.7:1 99 1.9080 5.0 16:1 99 1.6880 3.75 21.3:1 99 1.5880 2.5 32:1 98 1.4880 1.25 64:1 98 1.3840 10 4:1 98 1.5240 7.5 5.3:1 98 1.3140 5.0 8:1 97 1.1340 3.75 10.7:1 95 1.0540 2.5 16:1 93 0.9840 1.25 32:1 93 0.88*20 10 2:1 96 1.2620 7.5 2.7:1 96 1.0420 5.0 4:1 87 1.0120 3.75 5.3:1 75 1.2120 2.5 8:1 70 1.2020 1.25 16:1 72 0.94*10 10 1:1 97 1.0910 7.5 1.3:1 94 0.91*10 5.0 2:1 72 1.1710 3.75 2.7:1 55 1.5010 2.5 4:1 50 1.3910 1.25 8:1 44 1.30 5 10 1:2 96 1.01 5 7.5 1:1.5 91 0.87* 5 5.0 1:1 63 1.22 5 3.75 1.3:1 50 1.35 5 2.5 2:1 43 1.21 5 1.25 4:1 26 1.412.5 10 1:4 95 1.002.5 7.5 1:3 90 0.85*2.5 5.0 1:2 58 1.222.5 3.75 1:1.5 48 1.192.5 2.5 1:1 42 1.002.5 1.25 2:1 20 1.13______________________________________
TABLE II______________________________________BNPD vs. DDACppm ppm RatioBNPD.sup.1 DDAC.sup.2 BNPD:DDAC % I SI______________________________________80 0 100:0 9840 0 100:0 9220 0 100:0 6310 0 100:0 31 5 0 100:0 142.5 0 100:0 9 0 10 0:100 95 0 7.5 0:100 84 0 5.0 0:100 52 0 3.75 0:100 45 0 2.50 0:100 32 0 1.25 0:100 080 10 8:1 99 2.0680 7.5 10.7:1 99 1.8480 5.0 16:1 99 1.6380 3.75 21.3:1 98 1.5380 2.5 32:1 98 1.4480 1.25 64:1 98 1.3440 10 4:1 99 1.4940 7.5 5.3:1 98 1.2840 5.0 8:1 97 1.1040 3.75 10.7:1 95 1.0540 2.5 16:1 92 1.0040 1.25 32:1 94 0.83*20 10 2:1 98 1.2120 7.5 2.7:1 97 1.0220 5.0 4:1 87 1.0120 3.75 5.3:1 70 1.3920 2.5 8:1 62 1.4720 1.25 16:1 67 1.0510 10 1:1 98 1.0710 7.5 1.3:1 95 0.90*10 5.0 2:1 73 1.1210 3.75 2.7:1 48 1.7710 2.5 4:1 43 1.6710 1.25 8:1 35 1.64 5 10 1:2 97 1.00 5 7.5 1:1.5 93 0.85* 5 5.0 1:1 62 1.23 5 3.75 1.3:1 45 1.48 5 2.5 2:1 43 1.20 5 1.25 4:1 22 1.512.5 10 1:4 97 0.972.5 7.5 1:3 91 0.83*2.5 5.0 1:2 59 1.192.5 3.75 1:1.5 43 1.332.5 2.5 1:1 41 1.022.5 1.25 2:1 17 1.17______________________________________
In Tables I and II, differences seen between the replicates are due to normal experimental variance.
In accordance with Tables I-II supra., unexpected results occurred more frequently within the product ratios of BNPD to DDAC of from about 32:1 to 1:3. Since the BNPD product contains abut 95% active biocidal component and the DDAC product contains about 80% active biocidal component, when based on the active biocidal component, unexpected results appear more frequently within the range of active component of BNPD:DDAC of about 38:1 to 1:3. At present, it is most preferred that any commercial product embodying the invention comprises a weight ratio of active component of about 1:1 BNPD:DDAC.
While this invention has been described with respect to particular embodiments thereof, it is apparent that numerous other forms and modifications of this invention will be obvious to those skilled in the art. The appended claims and this invention generally should be construed to cover all such obvious forms and modifications which are within the true spirit and scope of the present invention.
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A microbial inhibiting composition and method is disclosed. The composition comprises an amount, effective for the intended purpose of 2-bromo-2-nitropropane-1,3-diol and didecyl dimethyl ammonium chloride. The method comprises administering an amount of this combined treatment to the particular water containing system for which treatment is desired.
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CROSS-REFERENCE TO RELATED APPLICATIONS
The present application claims priority under 35 U.S.C. § 119 of German Patent Application No. 198 52 634.2, filed on Nov. 4, 1998, the disclosure of which is expressly incorporated by reference herein in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is directed to a sheet forming system of a paper or cardboard machine, More specifically, the present invention is directed to a sheet forming system having a headbox with a nozzle and at least two guide mechanisms that guide screens in the region of the headbox nozzle over a guide surface.
2. Discussion of Background Information
A sheet forming system is disclosed in U.S. Pat. No. 4,358,342. This patent discloses the beginning of a sheet forming system of a papermaking machine with a twin wire former in the region of the headbox nozzle and the necked inlet gap of two screens. In the outlet region, the headbox nozzle has sectionally adjustable headbox lips that can influence or even out a base weight cross-direction profile of the paper web. Holding the upper and lower walls of the headbox nozzle in place requires a heavy and large support structure. To adjust the deformable upper or lower lip of the headbox, the relevant lip is supported on the heavily built base of die nozzle upper wall or nozzle lower wall.
Since this design requires a stable construction of the headbox up to the forward most region of the headbox nozzle, it is quite expensive. In addition, if the first two rolls of the screen section (that form the necked inlet gap) have large diameters, the headbox nozzle cannot be inserted far enough into the necked inlet gap. This results in a free jet that is too long, which decreases the quality of the manufacturing process.
German patent DE 41 05 215 C2 also discloses a sheet forming system in the region of the necked inlet gap of a twin screen section. In this system, the two rolls that form the necked inlet gap of the twin screen section are supported hydrostatically. The hydrostatic bearing across the width of the machine allows for compensation for deflection of the rolls. This uniformly maintains the inlet geometry of the necked gap over the entire width of the papermaking machine, even when small roll diameters are used.
SUMMARY OF THE INVENTION
The present invention provides a sheet forming system of a paper or cardboard machine with a headbox nozzle that is lighter than the prior art, yet which minimizes bending of the headbox nozzle.
According to an embodiment of the invention, a headbox nozzle includes two laterally arranged nozzle side panels, and first and second nozzle walls running the width of the machine. Two screens converge in the region of the output of the headbox nozzle. At least two guide mechanisms glide the screens in the region of the headbox nozzle over a guide surface. At least one support mechanism has at least one support element for supporting at least a portion of a nozzle wall against at least one guide surface.
The above embodiment may include various features At least one of the guide surfaces can be a roll surface and/or the surface of a guide shoe. At least one of the guide mechanisms can be a forming roll or a breast roll. The support elements of the support mechanism can be a roll or a shoe that slides or rolls over the roll surface. At least one of the support elements can haste at least one hydrostatic bearing or support. The support mechanism facing the nozzle wall may have at least one pressure chamber.
The support mechanism may be broken up into individual sections along the width of the machine that can be individually adjusted and controlled. Such a sectioned support may include a mechanism that controls the degree of support for each individual section. For example, control valves can individually control individual pressure chambers of the support mechanism. In the alternative, the support mechanism can also have a number of support elements (for example, individual spindles or hydraulic stamps), whose support action can be adjusted individually as needed.
The deflection of at least one of the guide mechanisms can be adjustable. A deflection compensation device, known per se for rolls, can be provided.
At least one supporting table with at least one pressure-producing device between the supporting table and the nozzle wall may be provided in the region of at least one nozzle wall. The pressure-producing device can have a single pressure chamber, or several individually controlled pressure chambers. Different pressure can be applied by the individual pressure chamber segments to produce a desired pressure cross-direction profile. The pressure-producing device is preferably upstream of the support mechanism between the nozzle wall and guide surface. In this arrangement, the supporting table is located relatively far from the necked inlet gap so that it has adequate space for a stable lower structure, unhindered by the rolls of the necked inlet gap.
According to an embodiment of the invention, a sheet forming system of a paper or cardboard machine is provided. A headbox had a headbox nozzle including two laterally extending side panels and first and second nozzle walls extending along a width of the machine. First and second screens converge in a region adjacent the headbox nozzle. At least two guide mechanisms, each having a guide surface, guide the first and second screens in the region. At least one support mechanism supports at least a portion of one of the first and second nozzle walls against the guide surface of at least one of the at least two guide mechanisms.
The above embodiment may have various features. At least one of the guide surfaces of the at least two guide mechanisms may be a roll surface or a surface of a guide shoe At least one of the at least two guide mechanisms can be one of a forming roll and a breast roll. At least one of the at least one support mechanism may be a roll or a shoe, and may have at least one of a hydrostatic bearing and support. The shoe may face the one of the first and second nozzle walls, and includes at least one pressure chamber.
The at least one support mechanism may be separated into a plurality of individual support mechanisms along a width of the machine. A control system may control the plurality of individual support mechanisms to adjust a degree of support provided along the width of the machine. The control system may individually control individual ones of the plurality of individual support mechanisms.
A deflection of at least one of the guide mechanisms may be adjustable.
The sheet forming system may her include at least one supporting table disposed in the one of the first and second nozzle walls, and at least one pressure-producing device between the supporting table and the one of the first and second nozzle walls. The pressure-producing device may include at least one pressure chamber, The at least one pressure chamber may include a plurality of pressure chambers along a width of the machine that can be individually controlled to apply different pressure. The pressure-producing device may be arranged upstream of the at least one support mechanism.
According to another embodiment of the invention, a sheet forming system of a paper or cardboard machine is provided. A headbox has a headbox nozzle including first and second nozzle walls extending along a width of the machine. First and second screens converge in a region adjacent the headbox nozzle. First and second guide rolls have first and second guide surfaces, respectively, that guide the first and second screens in the region. A support mechanism supports at least a part of the second nozzle wall against the second guide surface, the support mechanism being one of a roll and a shoe.
The above embodiment may have various features. The system may further include at least one supporting table disposed in the second nozzle wall, and at least one pressure chamber defined between the supporting table and the second nozzle wall. The one of roll and a shoe may include one of a plurality of individually elements, along a width of the machine that can be individually controlled to apply different pressure. The at least one pressure chamber may include a plurality of individually controlled pressure chambers along a width of the machine that can be individually controlled to apply different pressure.
In another embodiment of the invention, a sheet forming system of a paper or cardboard machine, includes a headbox with a headbox nozzle. The headbox nozzle includes first and second nozzle walls extending along a width of the machine. First and second screens converge in a region adjacent the headbox nozzle. First and second guide rolls have first and second guide surfaces, respectively, that guide the first and second screens in the region. A support mechanism supports at least a part of the second nozzle wall against the second guide surface, the support mechanism being one of a roll and a shoe At least one supporting table is disposed in the second nozzle wall. At least one pressure chamber defined between the supporting table and the second nozzle wall.
In yet another embodiment of the invention, a method for controlling a sheet forming system of a paper or cardboard machine is provided. The machine includes a headbox with a headbox nozzle. The headbox nozzle includes two laterally extending side panels and first and second nozzle walls extending along a width of the machine. First and second screens converge in a region adjacent the headbox nozzle. At least two guide mechanisms, each having a guide surface, and at least one support mechanism, are provided. The method includes guiding the first and second screens in the region via the at least two guide mechanisms, and supporting at least a portion of one of the first and second nozzle walls against the guide surface of at least one of the at least two guide mechanisms.
The at least one support mechanism may include a plurality of individual support mechanisms along a width of the machine. The method further includes controlling the plurality of individual support mechanisms to adjust a degree of support provided along the width of the machine.
Other exemplary embodiments and advantages of the present invention may be ascertained by reviewing the present disclosure and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is further described in the detailed description which follows, in reference to the noted plurality of drawings by way of non-limiting examples of certain embodiments of the present invention, in which like numerals represent like elements throughout the several views of the drawings, and wherein:
FIG. 1 a is sheet forming system with a support element hydraulically supported against a guide surface;
FIG. 1 b is a cross section of the embodiment of FIG. 1 a with a single support element runs across the width of the machine;
FIG. 1 c is a cross section of the embodiment of FIG. 1 a with a plurality of rectangular support elements running across the width of the machine;
FIG. 1 d is a cross section of the embodiment of FIG. 1 a with a plurality of circular support elements running across tie width of the machine;
FIG. 1 e is sheet forming system with a support element hydraulically supported against a guide surface, where the guide surface is a press shoe;
FIG. 2 a is a sheet forming system with a roll as a support element against a guide surface;
FIG. 2 b is a cross section of the embodiment of FIG. 2 a with a single support element runs across the width of the machine;
FIG. 2 c is a cross section of the embodiment of FIG. 2 a with a plurality of circular support elements running across the width of the machine;
FIG. 3 is sheet forming system with a supporting table for a nozzle wall;
FIG. 4 is a sheet forming system with a support element hydraulically supported against a guide surface and an additional supporting table; and
FIG. 5 is a sheet forming system with a roll as a support element against a guide surface, with an additional supporting table and hydrostatically supported guide roll on the opposite side of the guide surface.
DETAILED DESCRIPTION OF THE INVENTION
The particulars shown herein are by way of example and for purposes of illustrative discussion of the embodiments of the present invention only and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the present invention. In this regard, no attempt is made to show structural details of the present invention in more detail than is necessary for the fundamental understanding of the present inventions the description taken with the drawings making apparent to those skilled in the art how the several forms of the present invention may be embodied in practice.
Referring now to FIG. 1 a , a sheet forming system is positioned in the region of the necked inlet gap of a twin wire papermaking machine. A headbox nozzle 1 includes two laterally arranged nozzle side panels 100 (FIGS. 1 b - 1 d ), and first and second nozzle walls 2 . 1 and 2 . 2 running along the width of the machine. The nozzle discharge opening of headbox nozzle 1 extends into the necked gap of the screen section. A guide mechanism 4 . 1 , which is a guide roll in this embodiment and carries a screen 3 . 1 , defines an upper side of the necked gap. A lower guide mechanism 4 . 2 , which is a forming roll in this embodiment and carries a screen 3 . 2 , defines the lower side of the necked gap.
In this embodiment, second nozzle wall 2 . 2 is the lower of the two nozzle walls 2 . 1 and 2 . 2 . A support mechanism supports second nozzle wall 2 . 2 against a rotating guide surface 5 , 2 of guide mechanism 4 . 2 . The support mechanism includes a support shoe 6 a , which is hydrostatically supported on the side of second nozzle wall 2 . 2 by a pressure chamber 7 . A pressure cushion 8 is provided on the screen side of support shoe 6 a , with which support shoe 6 a can support itself against guide surface 5 . 2 by way of a hydraulic cushion. Screen 3 . 2 runs between support shoe 6 a and guide surface 5 . 2 . Fluid for the hydraulic cushion can be supplied, for example, through direct introduction of fluid into the pressure cushion 8 through channels via the support shoe 6 a , In the alternative, sufficient fluid can be applied to screen 3 . 2 ahead of support shoe 6 a in the direction of rotation of guide mechanism 4 . 2 so that an appropriate quantity of fluid collects and builds the necessary counterpressure.
As shown in FIG. 1 b , support shoe 6 a may be a single unit running the width of the machine. As shown in FIGS. 1 c and 1 d , support shoe 6 a may be a number of individually controllable pressure chambers, under control of a control system, across the width of the machine; although rectangular and circular segments are shown, the invention is not so limited, and other shaped may be used. Individual chambers allow the application of different individual pressures to profile the gap geometry of headbox nozzle 1 . Headbox nozzle 1 can be made lighter using such a support mechanism.
A variation of the above embodiment is shown in FIG. 1 e ,. In this modification, guide mechanism 4 . 1 is a press shoe 102 that carries screen 3 . 1 . The embodiment is otherwise the same as shown in FIG. 1 .
Another embodiment of the invention is shown in FIG. 2 . In FIG. 2, the support mechanism is a roller 6 b . An appropriate pressure cushion (or cushions) can support a roller 6 b hydrodynamically, as well as hydrostatically. The hydraulic support 104 can be uniform across roller 6 b as in FIG. 2 b , or separated into individual supports across the width of the machine as shown in FIG. 2 c . As in the embodiment of FIG. 1 a , individual support allows the application of different individual pressures to profile the gap geometry of headbox nozzle 1 .
Another embodiment of the present invention is shown in FIG. 3 . In this embodiment, second nozzle wall 2 . 2 has a recess in its rear section which, in conjunction with a supporting table 9 thereunder, defines a pressure chamber 10 . Supporting table 9 is heavily built and absorbs compressive forces that anise within pressure chamber 10 across the width of the machine, where a certain deflection can arise in this region. The relatively thin second nozzle wall 2 . 2 above it does not bend due to the uniform pressure relationships, despite counterpressure from the nozzle chamber, As with the above embodiment, pressure chamber 10 can be a single unit or be separated into individual units across the width of the machine. Individual control of individual pressure chambers with the desired pressures can control the profile of the gap geometry of headbox nozzle 1 .
FIG. 4 shows another embodiment of the invention. This embodiment is a combination of hydrostatic support shoe 6 a in the front region of the second nozzle wall 2 . 2 of the headbox nozzle 1 from the embodiment from FIG. 1 a , and additional support in the rear region of the second nozzle wall 2 . 2 with the aid of supporting table 9 and pressure chamber 10 from FIG. 3 .
FIG. 5 shows another embodiment of the invention. This embodiment is a combination of roller 6 b in the front region of the second nozzle wall 2 . 2 of the headbox nozzle 1 from the embodiment from FIG. 2, and additional support in the rear region of the second nozzle wall 2 . 2 with the aid of supporting table 9 and pressure chamber 10 from FIG. 3 . In addition, guide mechanism 4 . 1 is a guide roll which has a hydraulic support 11 , and is thus designed with an adjustable profile across the width of the machine.
It is noted that the foregoing examples have been provided merely for the purpose of explanation and are in no way to be construed as limiting of the present invention. While the present invention has been described with reference to certain embodiments, it is understood that the words which have been used herein are words of description and illustration, rather than words of limitation. Changes may be made, within the purview of the appended claims, as presently stated and as amended, without departing from the scope and spirit of the present invention in its aspects. Although the present invention has been described herein with reference to particular means, materials and embodiments, the present invention is not intended to be limited to the particulars disclosed herein; rather, the present invention extends to all functionally equivalent structures, methods and uses, such as are within the scope of the appended claims.
REFERENCE DESIGNATOR LIST
1 headbox nozzle
2 . 1 nozzle wall
2 . 2 nozzle wall
3 . 1 screen
3 . 2 screen
4 . 1 guide mechanism
4 . 2 guide mechanism
5 . 1 guide surface
5 . 2 guide surface
6 a support shoe
6 b roller
7 pressure chamber
8 pressure cushion
9 supporting table
10 pressure chamber
11 hydraulic support
100 side panels
102 press shoe
104 hydraulic support
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A sheet forming system of a paper or cardboard machine. A headbox includes a headbox nozzle with to laterally extending side panels and first and second nozzle walls extending along a width of the machine. First and second screens converge in a region adjacent the headbox nozzle. At least two guide mechanisms, each having a guide surface, guide the first and second screens in the region. At least one support mechanism supports at least a portion of one of the first and second nozzle walls against said guide surface of at least one of said at least two guide mechanisms.
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CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
This patent application claims priority based on provisional application U.S. Ser. No. 60/360,122, filed on Feb. 28, 2002.
FIELD OF THE INVENTION
An apparatus for measuring the angle between two rays, wherein the apparatus comprises a light source for generating a first light beam and a second light beam, a means for aligning these light beams to determine an angle to be measured.
BACKGROUND OF THE INVENTION
A goniometer is a device for measuring or setting angles. Prior art goniometers have utilized a number of principles to determine angles. Reference may be had, for example, to The Biomedical Engineering Handbook (Joseph D. Bronzino Ed., CRC Press LLC, 1995) pages 2177-2182.
Prior art goniometer designs include the following categories; Universal, Arthroidial, Fluid, Pendulum, Myrin OB, and Electrogoniometer.
The Universal Goniometer comprises a protractor-like measuring device with one movable arm and one stationary arm. The two arms are superimposed on the rays of the angle, and the measurement may be read on the protractor. Often, several goniometers of different sizes are required to measure different digits (i.e. a knee versus a finger). Additionally, the increments on the protractor limit the sensitivity of the measurement to the gradations on the instrument. The placement of the arms is also a source of error, as it is difficult to properly align relatively small arms parallel to a large extremity. Providing longer arms on the device may compensate, but this negatively impacts the portability of the device. Reference may be had, for example, to The Biomedical Engineering Handbook (Joseph D. Bronzino Ed., CRC Press LLC, 1995) page 2181.
The Arthroidial goniometer is a single protractor, similar to the Universal goniometer, but lacking arms. These instruments likewise suffer the same drawbacks. Reference may be had, for example, to The Biomedical Engineering Handbook (Joseph D. Bronzino Ed., CRC Press LLC, 1995) page 2181.
Fluid and Pendulum Goniometers utilize gravity to aid in measuring angles. Fluid goniometers contain a fluid-filled channel with an air bubble that moves as the device changes its angle relative to the gravitational plane. Likewise, Pendulum goniometers contain a pendulum for detecting angular changes. Such goniometers are often more accurate than their universal counterparts, but are additionally more expensive. Reference may be had, for example, to The Biomedical Engineering Handbook (Joseph D. Bronzino Ed., CRC Press LLC, 1995) page 2181.
Myrin Goniometers exploit a combination of gravity sensing devices and magnetic field sensing devices that respond to the Earth's magnetic field. These goniometers are often bulky and useless for measuring the angles associated with small joints, such as the fingers. They additionally suffer to electromagnetic interference. Reference may be had, for example, to The Biomedical Engineering Handbook (Joseph D. Bronzino Ed., CRC Press LLC, 1995) page 2181.
Electrogoniometers are physically strapped to the proximal and distal portions of the joint to be measured. These devices are inherently cumbersome and expensive. Each electrogoniometer is designed for specific body parts and they are typically used only as pieces of laboratory equipment. Reference may be had, for example, to The Biomedical Engineering Handbook (Joseph D. Bronzino Ed., CRC Press LLC, 1995) page 2181.
By way of further illustration, U.S. Pat. No. 3,634,838 discloses a goniometer arrangement that allows for the digital display of the measured angle. Such a digital display circumvents the difficulties associated with protractor measurements, such as being limited to the increments marked on the protractor.
U.S. Pat. No. 4,665,928 of Linial teaches the use of pendulum goniometers to determine angles on a living person. This patent also discloses the use of potentiometers to digitize the measurement, thus avoid protractor-like measurements.
U.S. Pat. No. 4,883,069 discloses an electrogoniometer that physically attaches to a joint through the use of straps.
U.S. Pat. No. 5,189,799 discloses a goniometer comprised of a single laser to determine the angle of a geographic feature.
U.S. Pat. No. 5,832,422 discloses a hand-held measuring device that is capable of measuring angles. The device tracks the angle the device is moved as it proceeds from a first position to a second position.
U.S. Pat. No. 6,428,490 discloses a series of resistive bend sensors that may be built into a garment to measure the range of motion for computer animation, for example. Such a suit would be undesirable for simple medical measurements due to the size of the device, its complexity, and its cost.
In spite of the substantial amount of prior art disclosing goniometers, these prior art goniometers suffer from a number of disadvantages. Many of the prior art instruments utilize manual, as opposed to digital, measurements, which inherently limit the precision of the measurements to the gradations on the protractor. Additionally, many prior art angle-measuring devices must use long arms in order to accurately visualize the rays of the angle to be measured. These long arms make these devices cumbersome and unsuitable for use with small joints. Additionally, many of the prior art goniometers are expensive, and difficult to transport, diminishing their usefulness as everyday instruments.
The instant invention seeks to overcome all of these disadvantages and provide a measuring device that utilizes light beams in place of traditional goniometer arms. The longer the arms of a traditional goniometer, the easier it becomes to estimate the position of the ray of the angle to be measured. However, longer arms make the device less portable. The instant invention replaces the physical arms of prior art goniometers with a beam of light. The long light beams mimic the advantageous function of long arms without requiring a large volume of space. Specifically, one light beam may be aligned along the length of one section of an extremity (i.e. lower leg), while the second light beam may be aligned along the length of a second section of the same extremity (i.e. upper leg). The goniometer may read the angle between the two beams throughout the flexion and extension of the extremity. In this manner, a range of motion may be determined.
It is an object of this invention to provide a lightweight, portable, hand-held goniometer.
It is another object of this invention to provide a goniometer that can easily, and accurately estimate the position of the two rays of an angle.
It is yet another object of this invention to provide a goniometer that digitally displays an angle measurement with a high degree of precision.
It is another object of this invention to provide a goniometer that is useful on both large joints and small joints.
SUMMARY OF THE INVENTION
In accordance with this invention, there is provided an apparatus for measuring the angle formed between a first beam of light and a second beam of light, wherein said apparatus is comprised of a first light source, a second light source movably connected to said first light source, and means for determining the angle formed between said first beam of light and said second beam of light.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described by reference to the specification, and the drawings, in which like numerals refer to like elements, and in which:
FIG. 1 is topside view of one embodiment of the light projecting goniometer, in its open position, being used to measure to angle of a joint, for example, a knee;
FIG. 2 is a perspective view of one embodiment of the light projecting goniometer in its closed position;
FIG. 3 is a perspective view of one embodiment of the light projecting goniometer in its open position;
FIG. 4 is a partially transparent view of one embodiment of the light projecting goniometer showing the inner structure of one arm of the device;
FIG. 5 is a schematic block diagram illustrating one embodiment of the invention; and
FIG. 6 is a schematic view of an alternative embodiment of the present invention.
DEFINITION OF TERMS
As used in this specification, the following terms have the meanings described hereinbelow.
The term “angle” refers to the geometric shape or arc that is defined by the intersection of two geometric rays. The term “vertex” refers to the point of intersection.
The term “ray” refers to one of the two imaginary geometric rays in an angle, extending outward from that angle's vertex. In a Universal goniometer, the two rays of an angle are visually approximated by the two arms of the goniometer. In the instant invention, one or more of the rays of an angle are visually approximated with the aid of a light beam.
Reference for these definitions may be had to, for example, The McGraw-Hill Encyclopedia of Science & Technology (Daniel N. Lapedes, Ed. McGraw-Hill, 1977) volume 1, page 427.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a schematic of device 10 , one preferred embodiment of the instant invention. As is illustrated in FIG. 1 , with the device of this invention one may measure any angle. To measure any angle, such as angle 24 in FIG. 1 , one may place a measuring device (not shown) at vertex 22 . Rays 26 and 28 then define the angle 24 . In the embodiment depicted in FIG. 1 , it is often difficult to define rays 26 and 28 when the objects with which they are aligned are relatively small.
Referring again to Figure, device 10 is one preferred goniometer of this invention. It will be seen that such device 10 preferably comprises means to emit light or similar radiant energy beams 16 and 18 . In the embodiment depicted, these means are disposed within arms 12 and 14 , respectively. Arms 12 and 14 are preferably pivotally connected to each other at pivot point 45 by means of a pivoting means 44 (not shown in FIG. 1 , but see FIG. 3 ). The pivotal connection provided by the pivoting means 44 allows one to superimpose the light beams 16 / 18 over the imaginary rays 26 / 28 of the angle 24 to be measured.
In the preferred embodiment depicted in FIG. 1 , the angle 24 to be measured corresponds to the bend of a knee joint 68 , defined by angle 20 .
In one embodiment, discussed elsewhere in this specification, the pivoting means 44 is connected to a means (not shown in FIG. 1 ) for determining the extent to which such means 44 has been pivoted. In one embodiment, the means for determining the angle maybe a linear potentiometer (not shown in FIG. 1 , but see FIG. 5 ). In another aspect of this embodiment, the angle detected by this latter means is displayed in a display area 32 .
Referring again to FIG. 1 , the assembly 10 is comprised of a power switch 34 and a reset/calibrate switch 36 .
FIG. 2 is a perspective view of the device 10 of FIG. 1 , shown it in its closed position. Referring to FIG. 2 , it will be seen that, in the embodiment depicted, the arm 12 is of an appropriate size and configuration to fit inside of arm 14 . Thus, the device may conveniently be stored in a “closed” position when not in use; in such closed position, it forms a substantially rectangular assembly. In one embodiment of the invention, the device is approximately 3 inches in height, 1.75 inches in width and 0.75 inches in thickness and weighs less than 0.5 kilogram. In another embodiment, the device is approximately 1 inch in height, 0.5 inches in width, and 0.25 inches in thickness and weighs less than 0.25 kilograms. In another embodiment the device is less than 1 cm in height, less than 0.5 inches in width, less than 0.25 inches in thickness, and weighs less than 50 grams.
Referring again to FIG. 2 , and in the preferred embodiment depicted therein, a control panel 30 is mounted on arm 14 . In the embodiment depicted, the control panel 30 is mounted atop arm 14 . In another embodiment, not shown, the control panel 30 is mounted on the side of arm 14 . Additionally, the control panel may comprise means to control the intensity of the light beams, means to indicate a low battery, and means to relay the measured angle to a data storage device.
Referring again to FIG. 2 , it will be seen that disposed on and within control panel 30 are a plurality of device controls and displays, including, for example, reset switch 36 , power switch 34 , and display 32 . Visible on the side of the device is light emission point 40 . In one embodiment reset switch 36 is used to “zero” the device such that display 32 reads an angle of zero degrees. In another embodiment, power switch 34 is used to turn the light sources off so as to prolong the lifetime of the power source.
FIG. 3 is a schematic illustration of the device 10 . FIG. 3 depicts the device 10 in one of its “open” positions. Control panel 30 is visible in this configuration. In this embodiment, disposed within control panel 30 are power switch 34 , reset switch 36 , and display 32 .
The display 32 may be any device for displaying the measured angle, such as a liquid crystal display, a light-emitting diode display or any of a number of display types employed in personal digital devices such as cellular phones, etc.
Referring again to FIG. 3 , and in the embodiment depicted, the control panel 30 is mounted atop arm 14 . Housed within arm 14 is a light source 46 (not shown in FIG. 3 , but see FIG. 4 ) which projects a beam of light from light emission point 40 . Arm 12 is likewise equipped with a light source 47 (not shown in FIG. 3 , but see FIG. 4 ) that preferably projects a beam of light from light emission point 38 . The light emission point 40 may be a hole in the housing of the arm 14 , or other means for delivering light, such as, for example, a fiber optic cable (not shown).
Referring again to FIG. 3 , it will be appreciated that, housed within arm 14 is a power supply (not shown) disposed behind access panel 42 , which may be, for example, a battery. The power supply is preferably adapted to deliver from about 1 to about 12 volts of direct current. It is preferred that an access panel 42 be removable so as to allow replacement of the power supply. Access panel 42 may be secured to device 42 by securing means, such as frictionally restrained by snap locks or securing by screws.
In another embodiment, not shown, a power supply may be used that is disposed external to arm 14 and to device 10 and connected to circuitry therein via a wire lead and jack as is commonly known for portable devices.
Referring again to FIG. 3 , arm 12 and arm 14 are pivotally connected to one another by pivot means 44 (not shown in FIG. 3 , but see FIG. 4 ) at pivot point 45 . The pivoting means may be, for example, a hinge (not shown in FIG. 3 , but see 44 in FIG. 4 ).
FIG. 4 is a schematic view of goniometer 10 . Referring to FIG. 4 , and the embodiment depicted therein, it will be seen that device 10 includes of a beam splitter 48 .
In the embodiment depicted in FIG. 4 , the light source 46 preferably provides at least one light beam 50 . In one aspect of this embodiment, the light beam 50 has a wavelength of from about 600 nanometers to about 700 nanometers.
As is known to those skilled in the art, a beam splitter is an optical device for dividing a beam into two or more separate beams. As will be apparent, the beam splitter 48 allows one to redirect a light beam so as to project light on a surface directly in front of the device. This allows the beams 52 / 53 to be easily visualized on the surface 55 and greatly aids in visualizing the two rays 72 / 74 of the angle 70 to be measured. An example of such redirection may be seen in FIG. 4 .
Referring again to FIG. 4 , it will be seen that, in the embodiment depicted, light source 46 emits a beam of light in the direction of arrow 50 . When the beam contacts redirection means 48 , the path of the light is altered such that some of the light is projected in the direction of arrow 52 . Additionally, as is illustrated in FIG. 4 , such redirection may also include spreading of the light 50 , so that a line 52 , as opposed to a single point, may be produced on the surface 55 where the beam strikes in front of the device 10 .
Such beam splitters and expanders are well known within the art and may be comprised of a wide variety of materials, including, but not limited to, mirrors, plastics, glass etc. Reference may be had to U.S. Pat. Nos. 5,822,124; 4,645,302; 4,125,864.
FIG. 5 is a schematic block diagram of an electronic circuit for detecting the angle between the first and second light beams. As may be seen in FIG. 5 , and in the embodiment depicted therein, linear response potentiometer 76 provides an analog signal 77 to an analog/digital (A/D) converter 78 . Analog signal 77 is proportional to the angle 70 between rays 72 and 74 . The A/D converter 78 produces digital signal 79 , which is provided to multiplexer 80 . Multiplexer 80 routes digital signal 79 to memory location 84 (“current angle”) if reset switch 90 is not activated. Alternately, if reset switch 90 is depressed, multiplexer 80 stores the value of signal 79 in memory location 82 (“zero angle”). Subtractor 86 then calculates the difference between the value currently in memory location 82 (“zero angle”) and memory location 84 (“current angle”) and continuously displays the result in angle display 88 . It will be appreciated that although described as a “digital” storage and manipulation device, the present invention may be implemented using equivalent analog devices to store/zero and measure the angle between the beams. It should be further appreciated that the present invention may be adapted to include additional data storage and/or display capability in order to facilitate its use in a variety of situations by physical therapists and the like.
In an alternative embodiment depicted in FIG. 6 , only one light source is used. In this embodiment a single light source 46 generates a light beam 60 that is split into two or more independent beams 64 and 66 . Such splitting means may include, for example, a beam splitter 62 , a reflective surface, and/or fiber optic cables 63 . The device is adapted to measure the angle 70 between the two light beams, irrespective of the fact that the two beams originated from the same light source.
The larger the goniometer is, the more difficult is its use for measuring small angles, such as those found on digits or fingers. It may be advantageous to minimize the size of the goniometer so as to make it useful with small joints. It should be noted that the instant goniometer is useful for a wide range of joint sizes. The small size of the device allows it to be used at small joints, such as fingers. Likewise, its long light beams, which serve the function of arms, are suitable for use at large joints such as the knee, elbow, hip, etc.
It is understood that the aforementioned description is illustrative only and that changes can be made in the apparatus, in the components and their proportions, and in the sequence of combinations and process steps, as well as in other aspects of the invention discussed herein, without departing from the scope of the invention as defined in the following claims.
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This device is a handheld, battery-operated instrument that utilizes light beams to project visible lines for increasing the accuracy in determining angles. A linear potentiometer is incorporated at the pivot point between the two diodes and measures a voltage change based on the angle between the arms of the device.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of Provisional Application Ser. No. 60/835,806, filed Aug. 3, 2006, Provisional Application Ser. No. 60/845,260, filed Sep. 18, 2006, Provisional Application Ser. No. 60/845,261, filed Sep. 18, 2006, Provisional Application Ser. No. 60/859,951, filed Nov. 20, 2006, Provisional Application Ser. No. 60/859,952, filed Nov. 20, 2006, Provisional Application Ser. No. 60/878,913, filed Jan. 4, 2007, Provisional Application Ser. No. 60/898,789, filed Jan. 31, 2007, Provisional Application Ser. No. 60/898,888, filed Jan. 31, 2007, Provisional Application Ser. No. 60/930,391, filed May 15, 2007, and to Provisional Application Ser. No. 60/949,112, filed Jul. 11, 2007. The contents of these applications are incorporated herein in their entirety by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to amorphous and crystalline forms of solifenacin base and to the preparation thereof.
BACKGROUND OF THE INVENTION
[0003] Solifenacin base of the following formula
[0000]
[0004] C 23 H 26 N 2 O 2
[0005] Exact Mass: 362.1994
[0006] Mol. Wt.: 362.4647
[0007] m/e: 362. 1994 (100.0%), 363.2028 (25.6%), 364.2061 (3.1%)
[0008] C, 76.21; H, 7.23; N, 7.73; 0, 8.83,
[0000] is the key intermediate of solifenacin salts such as solifenacin succinate. Solifenacin succinate, (3R)-1-azabicyclo[2.2.2]oct-3-yl-(1S)-1-phenyl-3,4-dihydroisoquinoline-2-(1H)-carboxylate-succinate, or (S)-Phenyl-1,2,3,4-tetrahydroisoquinoline-2-carboxylic acid 3(R)-quinuclidinyl ester succinate, of the chemical structure
[0000]
[0000] , is a urinary antispasmodic indicated for the treatment of urge incontinence and/or increased urinary frequency and urgency as may occur in patients with overactive bladder syndrome (OAB). The drug is marketed under the name Vesicare® in 5 mg and 10 mg tablets.
[0009] Solifenacin and derivatives thereof, as well as salts thereof, are reportedly encompassed in U.S. Pat. No. 6,017,927.
[0010] Solifenacin base is described in J. Med. Chem . (2005) 48(21), 6597-6606 as colorless oil. WO 2005/105795 reportedly encompasses a substance containing solifenacin or solifenacin itself.
[0011] Polymorphism, the occurrence of different solid state forms, is a property of some molecules and molecular complexes. A single molecule, like solifenacin base, may give rise to a variety of solid states forms having distinct crystal structures and physical properties such as melting point, powder x-ray diffraction (“PXRD”) pattern, infrared (“IR”) absorption fingerprint, and solid state nuclear magnetic resonance (“NMR”) spectrum. One solid state form may give rise to thermal behavior different from that of another solid state form. Thermal behavior can be measured in the laboratory by such techniques as capillary melting point, thermogravimetric analysis (“TGA”), and differential scanning calorimetry (“DSC”), which have been used to distinguish polymorphic forms.
[0012] The difference in the physical properties of different solid state forms results from the orientation and intermolecular interactions of adjacent molecules or complexes in the bulk solid. Accordingly, polymorphs are distinct solids sharing the same molecular formula yet having distinct advantageous physical properties compared to other solid state forms of the same compound or complex.
[0013] One of the most important physical properties of pharmaceutical compounds is their solubility in aqueous solution, particularly their solubility in the gastric juices of a patient. For example, where absorption through the gastrointestinal tract is slow, it is often desirable for a drug that is unstable to conditions in the patient's stomach or intestine to dissolve slowly so that it does not accumulate in a deleterious environment. Different solid state forms or polymorphs of the same pharmaceutical compounds can and reportedly do have different aqueous solubilities.
[0014] The discovery of new polymorphic forms of solifenacin base provides a new opportunity to improve the performance of the active pharmaceutical ingredient (“API”), solifenacin succinate, by producing solid state forms of solifenacin base having improved characteristics, such as stability, flowability, and solubility. Thus, there is a need in the art for polymorphic forms of solifenacin base.
SUMMARY OF THE INVENTION
[0015] In one embodiment, the invention encompasses solifenacin base in solid form.
[0016] In one embodiment, the invention encompasses an amorphous form of solifenacin base. The amorphous form of solifenacin base may be characterized by a PXRD pattern substantially as depicted in FIG. 1 .
[0017] Optionally, the above amorphous form of solifenacin base contains not more than about 10 wt %, preferably not more than about 5 wt %, more preferably not more than about 1 wt % of the crystalline form of solifenacin base characterized by PXRD peaks at about 7.7, 9.9, 16.2, and 20.9°±0.2° 2θ. Preferably, the above amorphous form of solifenacin base contains not more than about 10 wt %, preferably not more than about 5 wt %, more preferably not more than about 1 wt % of any single crystalline form of solifenacin base.
[0018] In another embodiment, the invention encompasses a process for preparing amorphous solifenacin base comprising reacting a solifenacin salt with an inorganic base.
[0019] In one embodiment, the invention encompasses a crystalline form of solifenacin base characterized by PXRD peaks at about 5.5, 13.2, 15.8, and 20.6°±0.2° 2θ.
[0020] Optionally, the above crystalline form of solifenacin base contains not more than about 10 wt %, preferably not more than about 5 wt %, more preferably not more than about 1 wt % of the crystalline form of solifenacin base characterized by PXRD peaks at about 7.7, 9.9, 16.2, and 20.9°±0.2° 2θ. Preferably, the above crystalline form of solifenacin base contains not more than about 10 wt %, preferably not more than about 5 wt %, and more preferably not more than about 1 wt % of any other single crystalline form of solifenacin base.
[0021] In another embodiment, the invention encompasses a process for preparing a crystalline form of solifenacin base characterized by PXRD peaks at about 5.5, 13.2, 15.8, and 20.6°±0.2° 2θ, comprising slurrying solifenacin base in diisopropylether.
[0022] In one embodiment, the invention encompasses a crystalline form of solifenacin base characterized by X-ray powder diffraction peaks at about 7.7, 9.9, 16.2, and 20.9°±0.2° 2θ.
[0023] Optionally, the above crystalline form of solifenacin base contains not more than about 10 wt %, preferably not more than about 5 wt % and more preferably not more than about 1 wt % of the crystalline form of solifenacin base characterized by PXRD peaks at about 5.5, 13.2, 15.8, and 20.6°±0.2° 2θ. Preferably, the above crystalline form of solifenacin base contains not more than about 10 wt %, preferably not more than about 5 wt %, and more preferably not more than about 1 wt % of any other single crystalline form of solifenacin base.
[0024] In another embodiment, the invention encompasses a process for preparing crystalline form of solifenacin base characterized by X-ray powder diffraction peaks at about 7.7, 9.9, 16.2, and 20.9°±0.2° 2θ, comprising
[0025] (a) reacting 1(S)-phenyl-1,2,3,4-tetraisoquinoline ethyl carbamate (“(S)-IQL ethyl carbamate”) with 3(R)-quinuclidinol (“(R)-QNC)” in the presence of a base and a first organic solvent;
[0026] (b) adding water to obtain a first two-phase system;
[0027] (c) separating the phases of the first two-phase system;
[0028] (d) adding acidic water to the organic phase from the first two-phase system to obtain a second two-phase system;
[0029] (e) separating the phases of the second two phase system;
[0030] (f) adding a second organic solvent and an inorganic base to the aqueous phase from the third two-phase system;
[0031] (g) separating the phases of the third two-phase system; and
[0032] (h) drying the organic phase separated from the third two phase system to obtain solifenacin base.
[0033] In one embodiment, the invention encompasses a process for preparing solifenacin salts, comprising preparing any one of the amorphous form of solifenacin base, the crystalline form of solifenacin base characterized by PXRD peaks at about 5.5, 13.2, 15.8, and 20.6°±0.2° 2θ, and crystalline form of solifenacin base characterized by X-ray powder diffraction peaks at about 7.7, 9.9, 16.2, and 20.9°±0.2° 2θ, and converting it to solifenacin salt.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] FIG. 1 illustrates a characteristic PXRD pattern of the amorphous form of solifenacin base.
[0035] FIG. 2 illustrates a characteristic PXRD pattern of solifenacin base crystalline form characterized by PXRD peaks at about 5.5, 13.2, 15.8, and 20.6°±0.2° 2θ.
[0036] FIG. 3 illustrates a characteristic PXRD pattern of solifenacin base crystalline form characterized by PXRD peaks at about 7.7, 9.9, 16.2, and 20.9°±0.2° 2θ.
DETAILED DESCRIPTION OF THE INVENTION
[0037] As used herein, the term “room temperature” or “RT” refers the ambient temperature of a typical laboratory, which is usually about 15° C. to about 30° C., often about 18° C. to about 25° C.
[0038] As used herein, the term “reflux temperature” refers to the boiling point of the solvent or mixture being heated.
[0039] As used herein, the term “vacuum” or “reduced pressure” refers to a pressure of about to 2 mmHg to about 100 mmHg.
[0040] As used herein, the term “PXRD” refers to powder X-ray diffraction, the term “IR” refers to infrared, the term “NMR” refers to nuclear magnetic resonance, the term “TGA” refers to thermogravimetric analysis, and the term “DSC” refers to differential scanning calorimetry.
[0041] As used herein, the term “(S)-IQL ethyl carbamate” refers to 1(S)-phenyl-1,2,3,4-tetraisoquinoline ethyl carbamate, the term “(R)-QNC” refers to 3(R)-quinuclidinol, the term “EtOAc” refers to ethyl acetate, the term “DCM” refers to dichloromethane, the term “MTBE” refers to methyltertbutyl ether, and the term “NaOMe” refers to alkoxide.
[0042] As used herein, the term “acidic water” refers to water with a pH of less than about 7.
[0043] The invention encompasses solifenacin base in solid form.
[0044] The invention further encompasses an amorphous form of solifenacin base. The amorphous form of solifenacin base may be characterized by a PXRD pattern substantially as depicted in FIG. 1 .
[0045] Optionally, the above amorphous form of solifenacin base contains not more than about 10 wt %, preferably not more than about 5 wt %, more preferably not more than about 1 wt % of the crystalline form of solifenacin base characterized by PXRD peaks at about 7.7, 9.9, 16.2, and 20.9°±0.2° 2θ. The weight percentage of the crystalline form of solifenacin base characterized by PXRD peaks at about 7.7, 9.9, 16.2, and 20.9°±0.2° 2θ may be calculated based on the percentages of area under the PXRD peaks.
[0046] Optionally, the amorphous form of solifenacin base contains not more than about 10 wt %, preferably not more than about 5 wt %, more preferably not more than about 1 wt % of any single crystalline form of solifenacin base. The weight percentages of the crystalline forms of solifenacin base may be calculated based on the percentages of area under the PXRD peaks.
[0047] The invention encompasses a process for preparing amorphous solifenacin base comprising reacting a solifenacin salt with an inorganic base.
[0048] Preferably, the reaction is performed by dissolving solifenacin salt in water to form a solution, and combining the solution with the inorganic base to form a reaction mixture.
[0049] Preferably, the process further comprises adding a water-immiscible organic solvent to obtain a two phase system, extracting the solifenacin base generated into the water-immiscible organic phase, and separating the phases to obtain an organic phase containing a mixture of solifenacin base and a water-immiscible organic solvent.
[0050] Preferably, the solifenacin salt is solifenacin succinate.
[0051] Optionally, the water immiscible organic solvent is added before or after the inorganic base is combined with the solution of solifenacin salt in water.
[0052] Preferably, the water-immiscible organic solvent is selected from the group consisting of halogenated aliphatic hydrocarbon, aromatic hydrocarbon, ester, halogenated aromatic hydrocarbon, and mixtures thereof. Preferably, the ester is selected from the group consisting of ethyl acetate, methyl acetate, butyl acetate, isopropyl acetate, and mixtures thereof. Preferably, the halogenated aromatic hydrocarbon is chlorobenzene. Preferably, the aromatic hydrocarbon is toluene. Preferably, the halogenated aliphatic hydrocarbon is selected from the group consisting of dichloromethane, chloroform, and mixtures thereof. Preferably, the water-immiscible organic solvent is selected from the group consisting of dichloromethane, toluene, and mixtures thereof.
[0053] Preferably, the inorganic base is selected from the group consisting of metal hydroxides, metal carbonates, metal bicarbonates, and mixtures thereof. Preferably, the metal hydroxide is selected from the group consisting of lithium hydroxide, sodium hydroxide, potassium hydroxide, and cesium hydroxide. More preferably, the metal hydroxide is NaOH. Preferably, the metal carbonate is selected from sodium carbonate and potassium carbonate. More preferably, the metal carbonate is sodium carbonate. Preferably, the metal bicarbonate is selected from sodium bicarbonate and potassium bicarbonate. Preferably, the inorganic base is NaOH.
[0054] The inorganic base may be provided as a solid or in an aqueous solution. Preferably, the inorganic base is provided in an aqueous solution.
[0055] Preferably, combining the inorganic base with the solution of solifenacin in water provides a reaction mixture having a pH of about 7 to about 14, more preferably of about 11 to about 14.
[0056] Optionally, the process further comprises recovering amorphous solifenacin base from the organic phase. Optionally, the organic phase may be washed with water. Optionally, the organic phase is in a slurry form. The amorphous solifenacin base may be recovered from the slurry by any method known in the art, for example, filtering the slurry to recover the water-immiscible organic phase and removing the solvent.
[0057] The recovering step may include removing the water-immiscible organic solvent. Preferably, the removal is by evaporation, more preferably under reduced pressure.
[0058] Optionally, after removing the water-immiscible organic solvent, an additional step of slurrying the solifenacin base in ether may be performed. Preferably, the ether is selected from the group consisting of diisopropylether, methyltertbutyl ether, diethylether, and mixtures thereof. More preferably, the ether is diisopropylether. Optionally, the slurry is maintained for sufficient time to obtain amorphous solifenacin base. Preferably, the slurry is maintained for about 4 to about 24 hours, more preferably for about 6 to about 10 hours. Preferably, the slurry is maintained at a temperature of about 0° C. to about 30° C., more preferably at about 20° C. to about 25° C.
[0059] Preferably, the obtained amorphous solifenacin base is in solid form.
[0060] The invention encompasses a crystalline form of solifenacin base (denominated “Form B1”) characterized by PXRD peaks at about 5.5, 13.2, 15.8, and 20.6°±0.2° 2θ. The crystalline form may be further characterized by PXRD peaks at about 9.7, 12.0, 16.1, 17.0, 19.7 and 24.0°±0.2° 2θ. The crystalline form may be further characterized by the PXRD pattern substantially as depicted in FIG. 2 .
[0061] Optionally, the above crystalline form of solifenacin base characterized by PXRD peaks at about 5.5, 13.2, 15.8, and 20.6°±0.2° 2θ contains not more than about 10 wt %, preferably not more than about 5 wt %, and more preferably not more than about 1 wt % of the crystalline form of solifenacin base characterized by PXRD peaks at about 7.7, 9.9, 16.2, and 20.9°±0.2° 2θ. The weight percentages of the crystalline forms may be calculated based on the area percentages of the PXRD peaks, for example peaks at 15.3 and 20.9°±0.2° 2θ.
[0062] Optionally, the above crystalline form of solifenacin base characterized by PXRD peaks at about 5.5, 13.2, 15.8, and 20.6°±0.2° 2θ contains not more than about 10 wt %, preferably not more than about 5 wt %, and more preferably not more than about 1 wt % of any other single crystalline form of solifenacin base.
[0063] The invention encompasses a process for preparing a crystalline form of solifenacin base characterized by PXRD peaks at about 5.5, 13.2, 15.8, and 20.6°±0.2° 2θ, comprising slurrying solifenacin base in diisopropylether.
[0064] Optionally, the starting solifenacin base is amorphous solifenacin base prepared according to the process described above. Optionally, the starting solifenacin base is prepared from reaction between (S)-IQL ethyl carbamate and (R)-QNC.
[0065] Preferably, prior to the slurrying step, the solifenacin base is extracted from an organic solvent selected from EtOAc and DCM.
[0066] Optionally, the process further comprises recovering the crystalline form of solifenacin base. Optionally, the recovery step comprises isolating the crystalline form by filtering and drying it. Preferably, the drying is for about 10 hours to about 24 hours. Preferably, the drying is performed at a temperature of about 40° C. to about 60° C. Preferably, the drying is performed under vacuum.
[0067] The invention encompasses a crystalline form of solifenacin base (denominated “Form B2”) characterized by PXRD peaks at about 7.7, 9.9, 16.2, and 20.9°±0.2° 2θ. The crystalline form may be further characterized by PXRD peaks at about 15.3, 18.3, 19.8, and 22.9°±0.2° 2θ. The crystalline form may be further characterized by the PXRD pattern substantially as depicted in FIG. 3 .
[0068] Optionally, the above crystalline form of solifenacin base characterized by PXRD peaks at about 7.7, 9.9, 16.2, and 20.9°±0.2° 2θ contains not more than about 10 wt %, preferably not more than about 5 wt %, and more preferably not more than about 1 wt % of the crystalline form of solifenacin base characterized by PXRD peaks at about 5.5, 13.2, 15.8, and 20.6°±0.2° 2θ. The weight percentages of the crystalline forms may be calculated based on the area percentages of the PXRD peaks, for example peaks at 5.5 and 15.8°± 0 . 2 ° 2 θ.
[0069] Optionally, the above crystalline form of solifenacin base characterized by PXRD peaks at about 7.7, 9.9, 16.2, and 20.9°±0.2° 2θ contains not more than about 10 wt %, preferably not more than about 5 wt %, and more preferably not more than about 1 wt % of any other single crystalline form of solifenacin base.
[0070] The invention encompasses a process for preparing crystalline form of solifenacin base characterized by PXRD peaks at about 7.7, 9.9, 16.2, and 20.9°±0.2° 2θ, comprising:
[0071] (a) reacting (S)-IQL ethyl carbamate with (R)-QNC in the presence of a base and a first organic solvent;
[0072] (b) adding water to obtain a first two-phase system;
[0073] (c) separating the phases of the first two-phase system;
[0074] (d) adding acidic water to the organic phase from the first two-phase system to obtain a second two-phase system;
[0075] (e) separating the phases of the second two phase system;
[0076] (f) adding a second organic solvent and an inorganic base to the aqueous phase from the third two-phase system;
[0077] (g) separating the phases of the third two-phase system;
[0078] (h) drying the organic phase separated from the third two phase system to obtain solifenacin base.
[0079] Optionally, the process further comprises maintaining the solifenacin base obtained from the organic phase separated from the second two phase system for a sufficient period of time at a temperature to obtain the crystalline form of solifenacin base. Preferably, the maintenance is for a period of about 2 hours to about 3 days, more preferably about 5 hours to about 48 hours. Preferably, the maintenance is at room temperature.
[0080] Preferably, the molar ratio between the (R)-QNC and the (S)-IQL ethyl carbamate in step (a) is from about 1.2 to about 1.7, more preferably from about 1.2 to about 1.5.
[0081] Preferably, the first organic solvent in step (a) is selected from the group consisting of toluene, xylene, and mixture thereof. More preferably, the organic solvent is toluene. Preferably, the ratio between the first organic solvent and the (S) —IQL ethyl carbamate is from about 0.5 to about 3 ml/g, more preferably from about 1 to about 2 ml/g.
[0082] Preferably, the base in step (a) is selected from the group consisting of NaH, NaNH 2 , metal alkoxide, and mixtures thereof. More preferably, the base is NaH. Preferably, the molar ratio between the base and the (S)-IQL ethyl carbamate is from about 0.15 to about 0.5, more preferably from about 0.15 to about 0.3.
[0083] Preferably, the acidic water in step (d) is added to obtain a pH of about 1 to about 4. Preferably, the acid is HCl.
[0084] Preferably, the second organic solvent in step (f) is selected from the group consisting of EtOAc, DCM, toluene, and mixtures thereof. More preferably, the organic solvent is EtOAc.
[0085] Preferably, the inorganic base in step (f) is selected from the group consisting of NaHCO 3 , KHCO 3 , K 2 CO 3 , Na 2 CO 3 , NaOH, KOH, and mixtures thereof. More preferably, the inorganic base is K 2 CO 3 .
[0086] Optionally, the drying is done by evaporation.
[0087] The invention encompasses a process for preparing solifenacin salts, comprising preparing any one of the amorphous form of solifenacin base, the crystalline form of solifenacin base characterized by PXRD peaks at about 5.5, 13.2, 15.8, and 20.6°±0.2° 2θ, and crystalline form of solifenacin base characterized by X-ray powder diffraction peaks at about 7.7, 9.9, 16.2, and 20.9°±0.2° 2θ, and converting it to solifenacin salt.
[0088] Preferably, the solifenacin salt is selected from the group consisting of solifenacin oxalate, solifenacin succinate, solifenacin acetate, and solifenacin-HX, wherein X is a halogen atom, preferably Cl. More preferably, the solifenacin salt is solifenacin succinate.
[0089] The amorphous form of solifenacin base, the crystalline form of solifenacin base characterized by PXRD peaks at about 5.5, 13.2, 15.8, and 20.6°±0.2° 2θ, and crystalline form of solifenacin base characterized by X-ray powder diffraction peaks at about 7.7, 9.9, 16.2, and 20.9°±0.2° 2θ may be converted to solifenacin salt by reacting the base with an acid, as described, for example, in U.S. patent application Ser. No. 11/645,021, WO 2005/075474, WO 2005/087231, WO 2005/105795, and in J. Med. Chem., 48(21), 2005, pp. 6597-6606, which are incorporated herein by reference. Preferably, the acid is selected from the group consisting of oxalic acid, succinic acid, acetic acid, and HX, wherein X is a halogen atom, preferably Cl. The conversion to solifenacin succinate may be performed by dissolving solifenacin base in organic solvent such as ethanol, ethyl acetate, methylethylketone, isopropylether, isobutylacetate, methylacetate, and MTBE; adding succinic acid; and cooling.
EXAMPLES
[0090] XRD diffraction was performed on Scintag X-ray powder diffractometer model X′TRA with a solid state detector. Copper radiation of 1.5418 Å was used. The sample holder was a round standard aluminum sample holder with rough zero background. The scanning parameters were: range: 2-40° 2θ; scan mode: continuous scan; step size: 0.05 deg.; rate: 5 deg/min.
Example 1
Preparation of Amorphous Solifenacin Base
[0091] Solifenacin-succinate (40 g) was dissolved in water (100 ml). NaOH solution (47%, 15 ml) was added, the pH was adjusted to 14, and then DCM (200 ml) was added. The phases were separated. The aqueous phase was extracted twice with DCM. The combined organic phase was divided into 10 parts, and each part was evaporated (30 mbar) to dryness at 40° C. to obtain amorphous solifenacin base solid.
Example 2
Preparation of Amorphous Solifenacin Base
[0092] SLF-succinate (10.4 g) was dissolved in water (25 ml) and toluene (50 ml). NaOH solution (1M, 20 ml and 47%, 2 ml) was added, and the pH was adjusted to 14. The phases were separated. The organic phase was extracted with water and evaporated to dryness to obtain solifenacin base (8.23 g).
[0093] Diisopropylether (100 ml) was added, and a sticky turbid slurry appeared. After stirring at RT overnight, the product was isolated by vacuum filtration under N 2 atmosphere to obtain amorphous SLF base solid.
Example 3
Preparation of Solifenacin Succinate
[0094] Amorphous SLF base (7.2 g) is dissolved in ethanol (28 ml) at room temperature to form a solution. Succinic acid (2.4 g) is then added to the solution to form a mixture. After two hours, the mixture is cooled to 5° C. The resulting precipitate is isolated by vacuum filtration, washed with ethanol (10 ml), and dried in a vacuum oven at 50° C. for 24 hours to obtain solifenacin succinate.
Example 4
Preparation of Solifenacin Base Form B1
[0095] An EtOAc solution of solifenacin base (prepared according to WO 2005/105795) was evaporated to obtain solifenacin base (40 g) as oil. Diisopropylether (200 ml) was added to the oil residue and stirred at RT overnight. The white solid was isolated by vacuum filtration under N 2 flow, and dried by vacuum oven at 55° C. for 24 hours to obtain solid of solifenacin base crystalline Form B1 (1.5 g).
Example 5
Preparation of Solifenacin Base Form B2
[0096] A 100 ml round bottom flask equipped with mechanical stirrer, thermometer and Dean-stark condenser was loaded with (S)-IQL-ethyl carbamate (18 g), toluene (45 ml), (R)-QNC (4.07 g), and NaH (60%, 0.77 g). The mixture was heated to reflux and stirred. At t=1, 2, and 3 hours, the mixture was monitored by HPLC for the formation of solifenacin base, and (R)-QNC (4.07 g) was added. After another hour (total 4 hours), the solution was diluted with toluene (10 ml/g of carbamate), and extracted with water (90 ml). The organic phase was extracted with HCl solution (4%, 108 ml). EtOAc (90 ml) and K 2 CO 3 (17.64 g) were added to the aqueous layer and the phases were separated.
[0097] The product was isolated by drying the EtOAc solution on MgSO 4 and evaporating the solvent to obtain solifenacin base (18.8 g). After a sufficient amount of time the residue has solidified to obtain solifenacin base crystalline Form B2.
Example 6
Preparation of Form I of Solifenacin Succinate
[0098] Solifenacin base (3.22 g) was dissolved in methylethylketone (30 ml) at room temperature. Then succinic acid (1.1 g) was added. The solution was stirred at room temperature for 18 hrs, during which it became a slurry. The product was isolated by vacuum filtration, washed with methylethylketone (2×5 ml), and dried in a vacuum oven at 50° C. overnight to obtain solifenacin succinate crystalline Form I (1.33 g, 31% yield).
Example 7
Preparation of Form I of Solifenacin Succinate
[0099] Solifenacin base (2.68 g) was dissolved in isopropylether (30 ml) at room temperature. Then succinic acid (1 g) was added. The solution was stirred at room temperature for 19 hrs, during which it became a slurry. The product was isolated by vacuum filtration, washed with IPA (2×3 ml), and dried in a vacuum oven at 50° C. overnight to obtain solifenacin succinate crystalline Form I (1.5 g, 42% yield).
Example 8
Preparation of Form I of Solifenacin Succinate
[0100] Solifenacin base (3.3 g) was dissolved in isobutylacetate (30 ml) at room temperature. Then succinic acid (1.1 g) was added. During the addition the solution became a slurry, and it was stirred at room temperature for 3 hrs. The product was isolated by vacuum filtration and dried in a vacuum oven at 50° C. overnight to obtain solifenacin succinate crystalline Form I (1.02 g, 23% yield).
Example 9
Preparation of Form II of Solifenacin Succinate
[0101] Solifenacin base (3.2 g) was dissolved in methylacetate (30 ml) at room temperature. Then succinic acid (1.1 g) was added, and the solution became a slurry. After 3.5 hrs, the product was isolated by vacuum filtration, washed with methylacetate (2×5 ml), and dried in a vacuum oven at 50° C. overnight to obtain solifenacin succinate crystalline Form II (2.94 g, 69% yield).
Example 10
Preparation of Form II of Solifenacin Succinate
[0102] Solifenacin base (3.26 g) was dissolved in MTBE (45 ml) at room temperature. Then succinic acid (1.1 g) was added, and the solution became slurry. After 4 hrs, the product was isolated by vacuum filtration, washed with MTBE (2×5 ml), and dried in a vacuum oven at 50° C. overnight to obtain solifenacin succinate crystalline Form II (3.31 g, 76.6% yield).
Example 11
Preparation of Solifenacin Base
[0103] A 100 ml round bottom flask equipped with mechanical stirrer, thermometer, and Dean-stark condenser was loaded with (S)-IQL-ethyl carbamate (25 g), xylene (25 ml), (R)-QNC (16.93 g), and NaH (60%, 0.53 g). The mixture was heated to reflux and stirred. The mixture was monitored by HPLC every hour. After 3 hours, the solution was diluted with xylene (225 ml), and extracted with water (125 ml). The organic phase was extracted with HCl solution (4%, 150 ml). EtOAc (150 ml) and K 2 CO 3 (24.5 g) were added to the aqueous layer, and the phases were separated. The solution was dried on MgSO 4 and evaporated to obtain solifenacin base (29 g).
Example 12
Preparation of Solifenacin Base Form B2
[0104] A 100 ml round bottom flask equipped with mechanical stirrer, thermometer, and Dean-stark condenser was loaded with (S)-IQL-ethyl carbamate (25 g), toluene (25 ml), (R)-QNC (16.96 g), and NaNH 2 (1.04 g). The mixture was heated to reflux and stirred. The mixture was monitored by HPLC for the formation of solifenacin base. After 8 hours the solution was diluted with toluene (9 ml/g of carbamate), and extracted with water (5 ml/g of carbamate). The organic phase was extracted with HCl solution (4%, 6 ml/g of carbamate). EtOAc (6 ml/g of carbamate) and K 2 CO 3 (24.5 g) were added to the aqueous layer, and the phases were separated. The solution was dried on MgSO 4 and evaporated to obtain solifenacin base (26.8 g). After a sufficient amount of time the residue has solidified to obtain solifenacin base crystalline Form B2.
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Polymorphic forms of solifenacin base have been prepared and characterized. These polymorphic forms are particularly useful for preparing solifenacin salts.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an ESD protection device and a layout thereof. More particularly, the present invention relates to an ESD protection device with equal-substrate-potential technology and a layout thereof.
[0003] 2. Description of Related Art
[0004] Electronic products are often impacted by ESD in practical use. Generally speaking, an ESD voltage is much higher than a common supply voltage, and discharge models can be classified into human-body model (HBM), machine model (MM), and charge-device model (CDM) based on different voltage levels generated by ESD. When ESD occurs, the ESD current is likely to burn the elements, such that some ESD protection measures must be taken in the circuit to effectively isolate the ESD current, so as to prevent the elements from being damaged.
[0005] Commonly, a design of ESD protection device is disposed between a core circuit and a pad to protect internal circuits. There are several tests for ESD protection devices, which can be classified into PD, PS, ND, and NS modes. The PD/ND mode inputs a positive pulse/negative pulse via the pad to bypass the ESD current to the conducting wire of a system voltage VDD. The PS/NS mode inputs a positive pulse/negative pulse via the pad to bypass the ESD current to the conducting wire of a ground voltage VSS.
[0006] FIG. 1 is a block view of an ESD protection circuit. Referring to FIG. 1 , the PD mode inputs a positive pulse 105 via a pad 101 and uses an ESD protection device 102 to bypass an ESD current to the system voltage trace VDD, so as to protect a core circuit 104 . The NS mode inputs a negative pulse 106 via the pad 101 and uses an ESD protection device 103 to bypass an ESD current to the ground voltage trace VSS, so as to protect the core circuit 104 . The operations of the PS, ND modes can be deduced in the same way. Further, electrostatic charges may be accumulated during the operation of the core circuit 104 , so the electrostatic charges generated by the core circuit 104 can also be bypassed and discharged by the ESD protection devices 102 , 103 .
[0007] A conventional ESD protection circuit is usually implemented by a gate-grounded n-channel metal-oxide-semiconductor (GGNMOS) transistor. FIG. 2 shows an ESD protection device implemented by a GGNMOS transistor. Referring to FIG. 2 , when a core circuit 204 operates normally, as the gate of an NMOS transistor MN 1 is grounded, the NMOS transistor MN 1 is turned off and will not be conducted. When ESD occurs, a high voltage 205 enters via a pad 201 . When the high voltage 205 exceeds a drain/substrate breakdown voltage of the NMOS transistor, the drain/substrate of the NMOS transistor may be broken down and generate a bulk current which triggers parasitic transistors inside the NMOS transistor to bypass the ESD current.
[0008] As the ESD protection circuit withstands the high voltage ESD, a channel width of several hundreds of microns is required in the layout. Thus, a layout of multi-finger type is used to reduce the occupied silicon area. However, the above layout manner may result in a different base resistance of a lateral parasitic bipolar junction transistor (BJT) inside each finger of the NMOS transistor, i.e., the parasitic transistor closer to a central circuit has a higher base resistance. When a snapback breakdown of an NMOS transistor occurs, the ESD current may be concentrated and conducted to a ground terminal via the lateral parasitic BJT of the broken-down NMOS transistor. As the NMOS transistor that has been broken down lowers the potential of the conducting wire coupled thereto, the ESD pulse will not trigger other NMOS transistors, thus causing a non-uniform problem of bypassing the ESD current and weakening the ESD protection ability. In order to solve the above problems, the base resistances of the parasitic transistors must be substantially the same.
[0009] FIG. 3A is a top view of an ESD protection circuit layout according to U.S. Pat. No. 5,811,856. FIG. 3B is a sectional view of the ESD protection circuit layout according to the U.S. Pat. No. 5,811,856. Referring to FIGS. 3A and 3B , the ESD protection circuit can be regarded as the ESD protection device 103 in FIG. 1 . The guard-ring formed by a P+ doped region 301 is used to avoid ESD current drain. A gate 302 and N+ doped regions 303 , 304 form a GGNMOS transistor, and the N+ doped regions 303 , 304 and a substrate 308 form a parasitic transistor 309 . N+ doped regions 307 , 311 , and the substrate 308 form a parasitic transistor 312 . Moreover, the N+ doped regions 305 , 307 and the substrate 308 form a parasitic transistor 310 .
[0010] A method of solving the non-uniform problem of bypassing the ESD current involves embedding a grounded P+ diffusion region 306 into the source 304 of a neighboring NMOS transistor, and making the base resistances of the parasitic transistors 309 , 310 , 312 being substantially the same, so as to simultaneously trigger the parasitic transistors to bypass the ESD current. However, the layout of embedding the P+ diffusion region 306 not only increases the layout area, but also results in an over low substrate resistance of the NMOS transistor in a deep-submicron complementary metal-oxide-semiconductor (CMOS) transistor process, thus making it difficult to trigger the internal parasitic transistors and bypass the ESD current in time to protect the core circuit.
[0011] FIG. 4 shows an ESD protection circuit disclosed in “Layout design on multi-finger MOSFET for on-chip ESD protection circuits in a 0.18-um Salicided CMOS process” (Proc. IEEE Int. Symp. Electronics, Circuits and Systems, 2001, pp. 361-364) published by Mr. M.-D. Ker, C.-H. Chuang, and W.-Y. Lo. Referring to FIG. 4 , another method of solving the non-uniform problem of bypassing the ESD current involves coupling a sensing circuit to the gate of an MOS transistor. The sensing circuit is generally constituted by a resistor RP 1 (or RN 1 ) and a capacitor CP 1 (or CN 1 ). When the sensing circuit senses the occurrence of an ESD event, the sensing circuit provides a bias to the gates of MOS transistors MP 1 , MP 2 (or MN 1 , MN 2 ), so as to simultaneously turn on the transistors MP 1 , MP 2 (or MN 1 , MN 2 ) to bypass the ESD current. The PMOS transistors MP 1 , MP 2 , capacitor CP 1 , and resistor RP 1 can be regarded as internal elements of the ESD protection device 102 in FIG. 1 . The NMOS transistors MN 1 , MN 2 , capacitor CN 1 , and resistor RN 1 can be regarded as internal elements of the ESD protection device 103 in FIG. 1 . The resistors RN 1 , RP 1 and capacitors CN 1 , CP 1 can be adjusted to provide a bias to the gates of the NMOS transistors MN 1 , MN 2 and PMOS transistors MP 1 , MP 2 to reduce the trigger voltage of the NMOS transistors MN 1 , MN 2 and PMOS transistors MP 1 , MP 2 . Thus, when ESD occurs, a smaller trigger voltage can trigger the NMOS transistors MN 1 , MN 2 or PMOS transistors MP 1 , MP 2 in time to bypass the ESD current. However, the high bias applied on the gate of the NMOS transistor MN 1 /PMOS transistor MP 1 may generate a larger channel current, and a higher electric field may cause the breakdown of a thin gate-oxide layer, thus weakening the ESD protection ability. In addition, the impedance of the resistors RN 1 , RP 1 in a common sensing circuit is extremely high (approximately 100 kilo-ohm), which may also increase the layout area.
[0012] FIG. 5 shows an ESD protection circuit according to the U.S. Pat. No. 5,631,793. Referring to FIG. 5 , the NMOS transistors MN 1 , resistor RN 1 , and capacitor CN 1 are internal elements of the ESD protection device 103 in FIG. 1 . A method of solving the non-uniform problem of bypassing the ESD current involves electrically connecting a sensing circuit to the substrate of the GGNMOS transistors MN 1 , MN 2 . The sensing circuit is constituted by a resistor RN 1 and a capacitor CN 1 . The resistor RN 1 and the capacitor CN 1 can be adjusted to provide an appropriate voltage to the bodies of the parasitic transistors (i.e., the substrates of the GGNMOS transistors MN 1 , MN 2 ), so as to increase the base voltage of the parasitic transistors, i.e., reducing the trigger voltage of the GGNMOS transistors MN 1 , MN 2 , such that the internal parasitic transistors can be triggered simultaneously to solve the non-uniform problem of bypassing the ESD current. Therefore, it is not necessary to apply a bias to the gates of the NMOS transistors MN 1 , MN 2 , thus avoiding generating an extra channel current that weakens the ESD protection ability. However, the additional resistor RN 1 and capacitor CN 1 may also increase the layout area.
[0013] FIG. 6 shows an ESD protection circuit according to the U.S. Pat. No. 5,686,751. Referring to FIG. 6 , a technology of solving the non-uniform problem of bypassing the ESD current involves triggering each finger of the NMOS transistor in a domino manner. In FIG. 6 , Rd 1 -Rdi are respectively ballast resistors of the drains of NMOS transistors MN 1 -MNi, and Rs 1 -Rsi are respectively ballast resistors of the sources of the NMOS transistors MN 1 -MNi. The NMOS transistors MN 1 -MNi and resistors Rd 1 -Rdi, Rs 1 -Rsi are internal elements of the ESD protection device 103 in FIG. 1 . When ESD occurs, as long as one of the NMOS transistors (for example, the NMOS transistor MN 1 ) is triggered, the ESD current provides a voltage to the gate of the NMOS transistor MN 2 via the ballast resistor Rs 1 . The triggered NMOS transistor MN 2 then allows the ESD current to pass through the ballast resistor Rs 2 to provide a voltage to the gate of the NMOS transistor MN 3 . The NMOS transistors MN 3 -MNi are triggered in the same way. However, though the non-uniform problem of bypassing the ESD current can be solved by the above conventional art, the complexity of the layout is increased.
SUMMARY OF THE INVENTION
[0014] An ESD protection device is provided by the present invention. Under a high voltage ESD, a plurality of ESD protection units can be triggered simultaneously to bypass the ESD current in time, so as to solve the non-uniform problem of bypassing the ESD current. In addition, when a core circuit under a small power supply operates together with an input/output interface (I/O interface) under a high voltage via an I/O pad, the ESD protection device can also work normally under a mixed-voltage operation.
[0015] An ESD protection device provided by the present invention can be applied to an output buffer with ESD protection ability which receives an output signal from the core circuit to control the ESD protection device to output an external signal, so as to enhance the output driving ability of the core circuit.
[0016] An ESD protection layout provided by the present invention is an implementation of the above ESD protection device. In a limited layout area, a doped region is disposed in the substrate, and a bias conducting wire is used to electrically connect the doped region, thus the base coupling manner of the parasitic transistors in the ESD protection device is completed. Under a high voltage ESD, the parasitic transistors can be triggered simultaneously to bypass the ESD current in time, so as to avoid the non-uniform problem of bypassing the ESD current.
[0017] In order to solve the above problem, an ESD protection device comprising a plurality of ESD protection units and a bias conducting wire is provided. A plurality of ESD protection units is used to transmit an electrostatic current between a first conductive path and a second conductive path, wherein each ESD protection unit comprises a parasitic transistor and a parasitic resistor. A collector and an emitter of each parasitic transistor are respectively coupled to the first conductive path and the second conductive path, and each parasitic resistor is coupled between a base of the corresponding parasitic transistor and the second conductive path. The bias conducting wire is coupled to each base of the above parasitic transistors.
[0018] An ESD protection device comprising a plurality of output driving units and a bias conducting wire is further provided. The plurality of output driving units is used to generate an external output signal according to a core output signal and output the external output signal to a first conductive path, wherein each output driving unit comprises a parasitic transistor and a parasitic resistor. A collector and an emitter of each parasitic transistor are respectively coupled to the first conductive path and a second conductive path, and each parasitic resistor is coupled between the base of the corresponding parasitic transistor and the second conductive path. The bias conducting wire is coupled to each base of the above parasitic transistors.
[0019] An ESD protection device comprising a plurality of transistors, a plurality of resistors, and a bias conducting wire is still provided. A collector and an emitter of each transistor are respectively coupled to a first conductive path and a second conductive path, for transmitting an electrostatic current between the first conductive path and the second conductive path. The plurality of resistors is respectively coupled between the base of the corresponding transistor and the second conductive path. The bias conducting wire is coupled to each base of the above transistors.
[0020] An ESD protection layout comprising a substrate, a first doped region, a first conductive path, a second conductive path, a plurality of ESD protection units, a plurality of second doped regions, and a bias conducting wire is further provided. The substrate has a parasitic resistor. The first doped region is disposed on the substrate, and serves as an electrode of the substrate. The first conductive path is disposed above the substrate. The second conductive path is disposed above the substrate. Each of the above ESD protection units is disposed on the substrate without contacting the first doped region, for transmitting an electrostatic current between the first conductive path and the second conductive path, wherein each ESD protection unit has a parasitic transistor structure. The plurality of second doped regions is disposed on the substrate between the ESD protection units, wherein each second doped region does not contact any of the ESD protection units. The bias conducting wire is disposed above the substrate, and is electrically connected to each of the above second doped regions.
[0021] An ESD protection layout comprising a substrate, a first doped region, a first conductive path, a second conductive path, a plurality of ESD protection units, a plurality of third doped regions, and a bias conducting wire is also provided. The first doped region is disposed on the substrate, and serves as an electrode of the substrate. The first and second conductive paths are respectively disposed above the substrate. The plurality of ESD protection units is disposed on the substrate without contacting the first doped region, for transmitting an electrostatic current between the first conductive path and the second conductive path, wherein each ESD protection unit comprises a first MOS transistor and a second MOS transistor connected in series between the first conductive path and the second conductive path. The plurality of third doped regions is disposed in the substrate and between the first and second MOS transistors without contacting the two MOS transistors. The bias conducting wire is disposed above the substrate, and is electrically connected to each of the above third doped regions.
[0022] The present invention couples the bases of the parasitic transistors inside the ESD protection units together, for simultaneously triggering the ESD protection units to bypass the ESD current when a high voltage ESD passes through the ESD protection device. Moreover, when the devices operating under different voltages works together, the ESD protection device can work normally under the mixed-voltage operation. Further, the ESD protection device is coupled to a preceding driving device to discharge the charges generated by the preceding driving device.
[0023] In order to make the features and advantages of the present invention comprehensible, preferred embodiments accompanied with figures are described in detail below.
[0024] It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
[0026] FIG. 1 is a block diagram of an ESD protection circuit.
[0027] FIG. 2 shows an ESD protection device implemented by a GGNMOS transistor.
[0028] FIG. 3A is a top view of a conventional ESD protection circuit layout.
[0029] FIG. 3B is a sectional view of a conventional ESD protection circuit layout.
[0030] FIG. 4 is a conventional ESD protection circuit.
[0031] FIG. 5 is a conventional ESD protection circuit.
[0032] FIG. 6 is a conventional ESD protection circuit.
[0033] FIG. 7 is an ESD protection device according to a preferred embodiment of the present invention.
[0034] FIG. 8 is an ESD protection device according to a preferred embodiment of the present invention.
[0035] FIG. 9 is an ESD protection device according to a preferred embodiment of the present invention.
[0036] FIG. 10 is an ESD protection device according to a preferred embodiment of the present invention.
[0037] FIG. 11 is an ESD protection device according to a preferred embodiment of the present invention.
[0038] FIG. 12 is an ESD protection device according to a preferred embodiment of the present invention.
[0039] FIG. 13A is a top view of an ESD protection layout according to a preferred embodiment of the present invention.
[0040] FIG. 13B is a sectional view of an ESD protection layout according to a preferred embodiment of the present invention.
[0041] FIG. 14 is a top view of an ESD protection layout according to a preferred embodiment of the present invention.
[0042] FIG. 15 is a top view of an ESD protection layout according to a preferred embodiment of the present invention.
[0043] FIG. 16A is a top view of an ESD protection layout according to a preferred embodiment of the present invention.
[0044] FIG. 16B is a sectional view of an ESD protection layout according to a preferred embodiment of the present invention.
[0045] FIG. 17 is a top view of an ESD protection layout according to a preferred embodiment of the present invention.
[0046] FIG. 18 is a top view of an ESD protection layout according to a preferred embodiment of the present invention.
[0047] FIG. 19 is a top view of an ESD protection layout according to a preferred embodiment of the present invention.
DESCRIPTION OF EMBODIMENTS
[0048] FIG. 7 is an ESD protection device according to a preferred embodiment of the present invention. Referring to FIG. 7 , an ESD protection device 703 is coupled between a pad 701 and a second conductive path (for example, a ground voltage trace) 702 . The pad 701 is coupled to a core circuit 706 via a first conductive path, and the pad 701 can be an input pad or an output pad. The ESD protection device 703 mainly includes ESD protection units 707 - 710 and a bias conducting wire 705 . This embodiment adopts, for example, a multi-finger type layout manner to implement the ESD protection device 703 , so as to reduce the occupied silicon area. Herein, only four ESD protection units 707 - 710 are taken as an example for illustration, and those of ordinary skill in the art can determine the number of the ESD protection unit as required.
[0049] Each of the ESD protection units 707 - 710 in this embodiment has an NMOS transistor (i.e., M 1 -M 4 in FIG. 7 ). As the NMOS transistors M 1 -M 4 are disposed in the substrate, each of the ESD protection units 707 - 710 has a parasitic transistor A 1 -A 4 and a parasitic resistor (substrate resistor) Ra 1 -Ra 4 . Resistors Rm 1 -Rm 4 are respectively coupled between the gates of the NMOS transistors M 1 -M 4 and the voltage trace 702 . Those of ordinary skill in the art can omit the resistors Rm 1 -Rm 4 as required, i.e., directly coupling the gates of the NMOS transistors M 1 -M 4 to the voltage trace 702 . In other embodiment, the gates of the NMOS transistors M 1 -M 4 is floating.
[0050] When ESD occurs, a high voltage 704 enters via the pad 701 . If the high voltage 704 exceeds the breakdown voltage between the drain and body of any (for example, the transistor M 2 ) of the NMOS transistors M 1 -M 4 , the interface between the drain and body of the NMOS transistor M 2 may be broken down to generate a bulk current. When the bulk current passes through a parasitic resistor Ra 2 , a bias voltage is generated. As the bias conducting wire 705 is used to connect the bases of the parasitic transistors A 1 -A 4 , the bias voltage not only triggers the parasitic transistor A 2 , but also simultaneously triggers other parasitic transistors A 1 , A 3 , A 4 . At this time, the parasitic transistors A 1 -A 4 bypass the ESD current through the first conductive path to the second conductive path (herein, a ground voltage trace) 702 , so as to prevent the ESD damaging the elements of the core circuit 706 , thus solving the non-uniform problem of bypassing the ESD current.
[0051] According to another embodiment of the present invention, the second conductive path 702 is a system voltage trace. If the second conductive path 702 is a system voltage trace, PMOS transistors can be used to substitute the NMOS transistors M 1 -M 4 in the ESD protection device 703 , in FIG. 7 .
[0052] FIG. 8 shows an ESD protection device according to a preferred embodiment of the present invention. Referring to FIG. 8 , the ESD protection device 803 can be used as a buffer. The ESD protection device 803 is coupled between a third conductive path (for example, a system voltage trace 801 ) and a second conductive path (for example, a ground voltage trace 802 ). The ESD protection device 803 mainly includes output driving units (or ESD protection units) 807 - 810 , a bias conducting wire 812 , and a bias conducting wire 813 . This embodiment uses, for example, a multi-finger type layout manner to implement the ESD protection device 803 . Herein, only four ESD protection units 807 - 810 are taken as an example for illustration, and those of ordinary skill in the art can determine the number of the ESD protection unit as required.
[0053] Each of the output driving units 807 - 810 in this embodiment has an NMOS transistor N 1 -N 4 and a PMOS transistor P 1 -P 4 . The transistors N 1 -N 4 and P 1 -P 4 are connected in series between the second conductive path (for example, the ground voltage trace 802 ) and the third conductive path (for example, the system voltage trace 801 ) (as shown in FIG. 8 ). As the NMOS transistors N 1 -N 4 are disposed on the substrate, each of the output driving units 807 - 810 has a parasitic transistor C 1 -C 4 and a parasitic resistor Rc 1 -Rc 4 . As the PMOS transistors P 1 -P 4 are disposed on the substrate, each of the output driving units 807 - 810 also has a parasitic transistor B 1 -B 4 and a parasitic resistor Rb 1 -Rb 4 .
[0054] In this embodiment, the ESD protection device 803 serves as an output buffer of a core circuit 805 . Each of the output driving units 807 - 810 generates an external output signal according to a core output signal output by the core circuit 805 and outputs the external output signal to a pad 804 via a first conductive path 811 . As the bias conducting wire 813 couples the bases of the parasitic transistors C 1 -C 4 together, and the bias conducting wire 812 couples the bases of the parasitic transistors B 1 -B 4 together, when ESD occurs, if any of the output driving units 807 - 810 is broken down due to the ESD, the bias voltage generated by the ESD current passing through a parasitic resistor turns on the parasitic transistors B 1 -B 4 and the parasitic transistors C 1 -C 4 via the bias conducting wires 812 , 813 .
[0055] For example, when the interface between the drain and body of the transistor N 2 (or P 2 ) is broken down due to the occurrence of ESD, the electrostatic current may pass through the parasitic resistor Rc 2 (or Rb 2 ) to generate a bias voltage. As the bias conducting wire 813 (or 812 ) is used to connect the bases of the parasitic transistors C 1 -C 4 (or B 1 -B 4 ), the bias voltage simultaneously triggers other parasitic transistors C 1 , C 3 , C 4 (or B 1 , B 3 , B 4 ). Therefore, when ESD occurs, all the output driving units 807 - 810 are triggered. The ESD current is bypassed to the third conductive path (for example, the system voltage trace 801 ) and/or the second conductive path (for example, the ground voltage trace 802 ) via each of the output driving units 807 - 810 , so as to prevent the electrostatic current damaging the elements inside the core circuit 805 , thus solving the non-uniform problem of bypassing the ESD current.
[0056] FIG. 9 shows an ESD protection device according to a preferred embodiment of the present invention. The ESD protection device 903 is coupled between a third conductive path (for example, a system voltage trace 901 ) and a second conductive path (for example, a ground voltage trace 902 ). The ESD protection device 903 mainly includes output driving units 907 , 908 , ESD protection units 909 , 910 , and bias conducting wires 912 , 913 . This embodiment uses, for example, a multi-finger type layout manner to implement the ESD protection device 903 . Herein, only two output driving units 907 , 908 and two ESD protection units 909 , 910 are taken as an example for illustration, and those of ordinary skill in the art can determine the number of the output driving unit and ESD protection unit as required.
[0057] Each of the output driving units 907 , 908 in this embodiment has a PMOS transistor P 5 , P 6 and an NMOS transistor N 5 , N 6 . Each of the ESD protection units 909 , 910 has an NMOS transistor N 7 , N 8 and a PMOS transistor P 7 , P 8 . The transistors N 5 -N 8 and P 5 -P 8 are connected in series between the second conductive path and the third conductive path (as shown in FIG. 9 ). Each of the transistors N 5 -N 8 has a parasitic transistor C 5 -C 8 and a parasitic resistor Rc 5 -Rc 8 . Each of the transistors P 7 , P 8 has a parasitic transistor B 5 -B 8 and a parasitic resistor Rb 5 -Rb 8 . The bias conducting wire 913 couples the bases of the parasitic transistors C 5 -C 8 together, and the bias conducting wire 912 couples the bases of the parasitic transistors B 5 -B 8 together.
[0058] In this embodiment, the ESD protection device 903 serves as an output buffer of a core circuit 905 . Each of the output driving units 907 , 908 generates an external output signal according to a core output signal output by the core circuit 905 and outputs the external output signal to a pad 904 via a first conductive path 911 . Referring to FIG. 9 , as the bias conducting wire 912 couples the bases of the parasitic transistors B 5 -B 8 together, and the bias conducting wire 913 couples the bases of the parasitic transistors C 5 -C 8 together. When ESD occurs, if any of the output driving units 907 , 908 or ESD protection units 909 , 910 is broken down due to the ESD, the bias voltage generated by the ESD current passing through a parasitic resistor turns on other parasitic transistors via the bias conducting wires 912 , 913 .
[0059] For example, when the interface between the drain and body of the transistor N 7 (or P 7 ) is broken down due to the occurrence of ESD, the electrostatic current may pass through the parasitic resistor Rc 7 (or Rb 7 ) to generate a bias voltage. As the bias conducting wire 913 (or 912 ) is used to connect the bases of the parasitic transistors C 5 -C 8 (or B 5 -B 8 ), the bias voltage simultaneously triggers other parasitic transistors C 5 , C 6 , C 8 (or B 5 , B 6 , B 8 ). Therefore, when ESD occurs, all the output driving units 907 , 908 and the ESD protection units 909 , 910 are triggered. The ESD current is bypassed to the third conductive path (for example, the system voltage trace 901 ) and/or the second conductive path (for example, the ground voltage trace 902 ) via the output driving units 907 , 908 and the ESD protection units 909 , 910 , so as to prevent the electrostatic current damaging the elements inside the core circuit 905 , thus solving the non-uniform problem of bypassing the ESD current.
[0060] Moreover, along with the progress of semiconductor transistor process, the supply voltage required by a core circuit becomes smaller, so as to reduce the power consumption and heat dissipation. However, the core circuit operating under a low voltage is still likely to work together with other I/O interfaces operating under a high supply voltage. In such a mixed-voltage operation, the ESD protection device must maintain the ESD protection ability still remains when the core circuit works under a high voltage, so as to improve the voltage tolerance of the ESD protection device.
[0061] FIG. 10 shows an ESD protection device according to a preferred embodiment of the present invention. Referring to FIG. 10 , a pad 1001 is coupled to a core circuit 1006 via a first conductive path. The ESD protection device 1003 is coupled between the first conductive path and a second conductive path (for example, a ground voltage trace 1002 ). The pad 1001 can be an input pad or an output pad. The ESD protection device 1003 mainly includes ESD protection units 1007 - 1010 and a bias conducting wire 1005 . This embodiment uses, for example, a multi-finger type layout manner to implement each of the ESD protection units, so as to reduce the occupied silicon area. Herein, only four ESD protection units 1007 - 1010 are taken as an example for illustration, and those of ordinary skill in the art can determine the number of the ESD protection unit as required.
[0062] Each of the ESD protection units 1007 - 1010 in this embodiment has a first MOS transistor (for example, an NMOS transistor Q 1 -Q 4 ) and a second MOS transistor (for example, an NMOS transistor D 1 -D 4 ). The first and second MOS transistors are connected in series between the first conductive path and the second conductive path (for example, the ground voltage trace 1002 ) (as shown in FIG. 10 ). The gates of the transistors Q 1 -Q 4 are coupled to the second conductive path. The gates of the transistors D 1 -D 4 are coupled to a third conductive path (for example, a system voltage trace VDD). As the NMOS transistors Q 1 -Q 4 , D 1 -D 4 are disposed on the substrate, each of the ESD protection units 1007 - 1010 has a parasitic transistor E 1 -E 4 and a parasitic resistor Re 1 -Re 4 . Resistors Rq 1 -Rq 4 are respectively coupled between the gates of the NMOS transistors Q 1 -Q 4 and the ground voltage trace 1002 , and those of ordinary skill in the art can omit the resistors Rq 1 -Rq 4 as required, i.e., directly coupling the gates of the NMOS transistors Q 1 -Q 4 to the ground voltage trace 1002 . In other embodiment, the gates of the NMOS transistors Q 1 -Q 4 is floating.
[0063] Referring to FIGS. 7 and 10 , the difference between FIGS. 7 and 10 is that the NMOS transistors Q 1 -Q 4 are respectively connected in series with the NMOS transistors D 1 -D 4 , so as to improve the trigger voltage of each of the high ESD protection units 1007 - 1010 , thus making the ESD protection device 1003 have a high voltage tolerance. As the bias conducting wire 1005 couples the bases of the parasitic transistors E 1 -E 4 together, when ESD occurs, if any of the ESD protection units 1007 - 1010 is broken down due to the ESD, the bias voltage generated by the ESD current turns on the parasitic transistors E 1 -E 4 via the bias conducting wire 1005 . The gates of the NMOS transistors D 1 -D 4 are coupled to the system voltage VDD and conducted. Those of ordinary skill in the art should understand that the same purpose can be achieved by coupling the gates of the PMOS transistors to the ground voltage VSS, and this embodiment will not be limited herein.
[0064] FIG. 11 shows the equivalent circuit of aqual-substrate-potential stacked-NMOS used as an ESD protection device according to a preferred embodiment of the present invention. Referring to FIG. 11 , the ESD protection device 1103 can be used as a self-protecting output buffer. The ESD protection device 1103 is coupled between a third conductive path (for example, a system voltage trace 1101 ) and a second conductive path (for example, a ground voltage trace 1102 ). The ESD protection device 1103 mainly includes a plurality of output driving units (only four output driving units 1107 - 1110 are illustrated in FIG. 11 ), and bias conducting wires 1113 .
[0065] Each of the output driving units 1107 - 1110 in this embodiment has an NMOS transistor W 1 -W 4 , an NMOS transistor X 1 -X 4 , and a PMOS transistor Y 1 -Y 4 . Each of the output driving units 1107 - 1110 has a parasitic transistor F 1 -F 4 , and a parasitic resistor Rf 1 -Rf 4 . The bias conducting wire 1113 couples the bases of the parasitic transistors F 1 -F 4 together.
[0066] In this embodiment, the ESD protection device 1103 serves as an output buffer of a core circuit 1105 . Each of the output driving units 1107 - 1110 generates an external output signal according to a core output signal output by the core circuit 1105 and outputs the external output signal to a pad 1104 via a first conductive path 1111 . Referring to FIGS. 8 and 11 , the circuit operation manner of this embodiment is similar to that of the embodiment in FIG. 8 , and the details will not be described herein again. One of the difference between FIG. 11 and FIG. 8 involves that in FIG. 11 , NMOS transistors X 1 -X 4 are respectively connected in series between the NMOS transistors W 1 -W 4 and the PMOS transistors Y 1 -Y 4 , so as to respectively raise the trigger voltage of each of the high ESD protection units 1107 - 1110 , thus making the ESD protection device 1103 have a high voltage tolerance.
[0067] FIG. 12 shows an ESD protection device according to a preferred embodiment of the present invention. The ESD protection device 1203 is coupled between a third conductive path (for example, a system voltage trace 1201 ) and a second conductive path (for example, a ground voltage trace 1202 ). The ESD protection device 1203 mainly includes output driving units 1207 , 1208 , ESD protection units 1209 , 1210 , and a bias conducting wire 1213 . Herein, only two output driving units 1207 , 1208 and two ESD protection units 1209 , 1210 are taken as an example for illustration, and those of ordinary skill in the art can determine the number of the output driving unit and ESD protection unit as required.
[0068] The output driving units 1207 , 1208 respectively have parasitic transistors F 5 , F 6 and parasitic resistors Rf 5 , Rf 6 . The ESD protection units 1209 , 1210 respectively have parasitic transistors F 7 , F 8 and parasitic resistors Rf 7 , Rf 8 . The bias conducting wire 1213 couples the bases of the parasitic transistors F 5 -F 8 together.
[0069] Referring to FIGS. 9 and 12 , the circuit operation manner of this embodiment is similar to that of the embodiment in FIG. 9 , and the details will not be described herein again. One of the difference between FIG. 12 and FIG. 9 is that, in FIG. 12 , NMOS transistors X 5 -X 8 are respectively connected in series between the NMOS transistors W 5 -W 8 and the PMOS transistors Y 5 , so as to respectively raise the trigger voltage of each of the output driving units 1207 , 1208 , and each of the ESD protection units 1209 , 1210 , thus making the ESD protection device 1203 have a high voltage tolerance. It should be noted that though a possible configuration of the ESD protection device has been described in the above embodiment of the present invention, those of ordinary skill in the art should understand that the adopted ESD protection elements are different. For example, NMOS transistors are taken as an example of the ESD protection elements for illustration in the above embodiment, while PMOS transistors can also be used as ESD protection elements to substitute the NMOS transistors. Therefore, the application of the present invention is not limited to this possible configuration. In other words, any configuration that couples the bases of a portion of or all the parasitic transistors inside the ESD protection device together, and provides the parasitic transistors in the ESD protection device with an equal-substrate-potential, for simultaneously triggering the parasitic transistors to bypass the ESD current conforms to the spirit of the present invention.
[0070] Next, another embodiment is given below to enable those of ordinary skill in the art to implement the above embodiment. FIG. 13A is a top view of the ESD protection layout according to the embodiment in FIG. 7 . FIG. 13B is a sectional view of the ESD protection layout according to the embodiment in FIG. 7 . Referring to FIGS. 13A and 13B , the ESD protection layout of this embodiment includes a P-type substrate 1303 , a first doped region 1304 , ESD protection units 1307 - 1310 , second doped regions 1320 - 1321 , a first conductive path 1301 , a second conductive path 1302 , and a bias conducting wire 1305 . Each of the ESD protection units 1307 - 1310 has an NMOS transistor and a parasitic transistor structure. The substrate 1303 has parasitic resistors inside. The first doped region 1304 is a P+ doped region, which is disposed on the substrate 1303 and coupled to a ground voltage, serving as an electrode of the P-type substrate 1303 .
[0071] The ESD protection unit 1307 has an NMOS transistor formed by N+ doped regions 1311 , 1312 and a gate 1316 , and has a parasitic transistor formed by N+ doped regions 1311 , 1312 and the P-type substrate 1303 . The ESD protection unit 1308 has an NMOS transistor formed by N+ doped regions 1312 , 1313 and a gate 1317 , and has a parasitic transistor formed by N+ doped regions 1312 , 1313 and the P-type substrate 1303 . The ESD protection unit 1309 has an NMOS transistor formed by N+ doped regions 1313 , 1314 and a gate 1318 , and has a parasitic transistor formed by N+ doped regions 1313 , 1314 and the P-type substrate 1303 . The ESD protection unit 1310 has an NMOS transistor formed by N+ doped regions 1314 , 1315 and a gate 1319 , and has a parasitic transistor formed by N+ doped regions 1314 , 1315 and the P-type substrate 1303 .
[0072] The ESD protection units 1307 - 1310 are used to transmit an ESD current between the first conductive path 1301 and the second conductive path 1302 . Therefore, the N+ doped regions 1312 , 1314 (the drains of the NMOS transistors) are coupled to the first conductive path 1301 , wherein the first conductive path 1301 is electrically connected to a pad 1306 (also, an output pad or input pad herein). The N+ doped regions 1311 , 1313 , 1315 (the sources of the NMOS transistors) and the gates 1316 - 1319 are coupled to the second conductive path 1302 (also, a ground voltage trace herein).
[0073] This embodiment couples the bases of the internal parasitic transistors together via the bias conducting wire 1305 , so as to simultaneously trigger the parasitic transistors to bypass the ESD current. In order to electrically connect the bias conducting wire 1305 and the bases of the parasitic transistors, the second doped regions 1320 , 1321 are respectively disposed in the N+ doped regions 1312 , 1314 . The second doped regions 1320 , 1321 are respectively isolated from the N+ doped regions 1312 , 1314 by a field oxide layer (or other isolation techniques). The second doped regions 1320 , 1321 are P+ doped regions, and the bias conducting wire 1305 is electrically connected to the second doped regions 1320 , 1321 .
[0074] In another embodiment of the present invention, each of the ESD protection units 1307 - 1310 can be implemented by a PMOS transistor, such that the substrate 1303 is an N-type substrate (or an N-type well disposed in a P-type substrate), the first doped region is an N+ doped region and coupled to the system voltage, the second doped regions 1311 - 1312 are N+ doped regions, and the second conductive path 1302 is a system voltage trace.
[0075] FIG. 14 is a top view of an ESD protection layout according to a preferred embodiment of the present invention. Referring to FIGS. 14 and 13A , the difference between FIGS. 14 and 13A lies in that second doped regions 1322 - 1324 are respectively disposed in the N+ doped regions 1311 , 1313 , 1315 . The second doped regions 1322 - 1324 are respectively isolated from the N+ doped regions 1311 , 1313 , 1315 by a field oxide layer (or other isolation techniques). The second doped regions 1322 - 1324 are P+ doped regions, and the bias conducting wire 1305 is electrically connected to the second doped regions 1322 - 1324 , so as to couple the bases of the internal parasitic transistors together.
[0076] FIG. 15 is a top view of an ESD protection layout according to a preferred embodiment of the present invention. Referring to FIGS. 15 and 13A , in this embodiment, the second doped regions 1320 - 1324 are respectively disposed in the N+ doped regions 1311 - 1315 . The second doped regions 1320 - 1324 are respectively isolated from the N+ doped regions 1311 - 1315 by a field oxide layer (or other isolation techniques). The second doped regions 1320 - 1324 are P+ doped regions, and the bias conducting wire 1305 is electrically connected to the second doped regions 1320 - 1324 , so as to couple the bases of the internal parasitic transistors together.
[0077] FIG. 16A is a top view of the ESD protection layout according to the embodiment in FIG. 10 . FIG. 16B is a sectional view of the ESD protection layout according to the embodiment in FIG. 10 . Referring to FIGS. 16A and 16B together, the ESD protection layout of this embodiment includes a P-type substrate 1603 , a first doped region 1604 , ESD protection units 1607 - 1610 , second doped regions 1630 - 1631 , N+ doped regions 1611 - 1619 , a first conductive path 1601 , a second conductive path 1602 , and a bias conducting wire 1605 . The P-type substrate 1603 has parasitic resistors inside. The ESD protection units 1607 - 1610 are implemented by NMOS transistors. The first doped region 1604 is a P+ doped region, which is disposed in the P-type substrate 1603 and coupled to a ground voltage trace, serving as an electrode of the substrate 1603 .
[0078] The ESD protection unit 1607 has two serially connected NMOS transistors formed by the N+ doped regions 1611 - 1613 and gates 1620 - 1621 , and has a parasitic transistor formed by the N+ doped regions 1611 , 1613 and the substrate 1603 . The ESD protection unit 1608 has two serially connected NMOS transistors formed by the N+ doped regions 1613 - 1615 and gates 1622 - 1623 , and has a parasitic transistor formed by the N+ doped regions 1613 , 1615 and the substrate 1603 . The ESD protection unit 1609 has two serially connected NMOS transistors formed by the N+ doped regions 1615 - 1617 and gates 1624 - 1625 , and has a parasitic transistor formed by the N+ doped regions 1615 , 1617 and the substrate 1603 . The ESD protection unit 1610 has two serially connected NMOS transistors formed by the N+ doped regions 1617 - 1619 and gates 1626 - 1627 , and has a parasitic transistor formed by the N+ doped regions 1617 , 1619 and the substrate 1603 .
[0079] The ESD protection units 1607 - 1610 are used to transmit an ESD current between the first conductive path 1601 and the second conductive path 1602 . Therefore, the N+ doped regions 1613 , 1617 are coupled to the first conductive path 1601 , wherein the first conductive path 1601 is electrically connected to a pad 1606 (an output pad or input pad herein). The N+ doped regions 1611 , 1615 , 1619 and the gates 1620 , 1623 , 1624 , 1627 are coupled to the second conductive path 1602 (a ground voltage trace herein). In addition, the gates 1621 , 1622 , 1625 , 1626 are coupled to the system voltage VDD.
[0080] This embodiment couples the bases of the internal parasitic transistors together via the bias conducting wire 1605 , so as to simultaneously trigger the parasitic transistors to bypass the ESD current. In order to electrically connect the bias conducting wire 1605 and the bases of the parasitic transistors, the second doped regions 1630 - 1631 are respectively disposed in the N+ doped regions 1613 , 1617 . The second doped regions 1630 - 1631 are respectively isolated from the N+ doped regions 1613 , 1617 by a field oxide layer (or other isolation techniques). The second doped regions 1630 - 1631 are P+ doped regions, and the bias conducting wire 1605 is electrically connected to the second doped regions 1630 - 1631 .
[0081] In another embodiment of the present invention, each of the ESD protection units 1607 - 1610 can be implemented by two serially connected PMOS transistors, such that the substrate 1603 is an N-type substrate (or an N-type well disposed in a P-type substrate), the first doped region is an N+ doped region and coupled to the system voltage, the second doped regions 1630 - 1631 are N+ doped regions, and the second conductive path 1602 is a system voltage trace.
[0082] FIG. 17 is a top view of an ESD protection layout according to a preferred embodiment of the present invention. Referring to FIGS. 17 and 16A , the difference between FIGS. 17 and 16A lies in that third doped regions 1632 - 1635 are respectively disposed in the N+ doped regions 1612 , 1614 , 1616 , 1618 . The third doped regions 1632 - 1635 are respectively isolated from the N+ doped regions 1612 , 1614 , 1616 , 1618 by a field oxide layer (or other isolation techniques). The third doped regions 1632 - 1635 are P+ doped regions, and the bias conducting wire 1605 is electrically connected to the third doped regions 1632 - 1635 , so as to couple the bases of the internal parasitic transistors together.
[0083] FIG. 18 is a top view of an ESD protection layout according to a preferred embodiment of the present invention. Referring to FIGS. 18 and 16A , in this embodiment, P+ doped regions 1636 - 1638 are respectively disposed in the N+ doped regions 1611 , 1615 , 1619 . The second doped regions 1636 - 1638 are respectively isolated from the N+ doped regions 1611 , 1615 , 1619 by a field oxide layer (or other isolation techniques). The bias conducting wire 1605 is electrically connected to the second doped regions 1636 - 1638 , so as to couple the bases of the internal parasitic transistors together.
[0084] FIG. 19 is a top view of an ESD protection layout according to a preferred embodiment of the present invention. Referring to FIGS. 19 and 16A , in this embodiment, the second doped regions 1636 , 1630 , 1637 , 1631 , 1638 are respectively disposed in the N+ doped regions 1611 , 1613 , 1615 , 1617 , 1619 . The second doped regions 1636 , 1630 , 1637 , 1631 , 1638 are respectively isolated from the N+ doped regions 1611 , 1613 , 1615 , 1617 , 1619 by a field oxide layer (or other isolation techniques). The second doped regions 1630 - 1631 , 1636 - 1638 are P+ doped regions, and the bias conducting wire 1605 is electrically connected to the second doped regions 1630 - 1631 , 1636 - 1638 , so as to couple the bases of the internal parasitic transistors together.
[0085] In view of the above, the ESD protection device provided by the present invention couples the bases of the parasitic transistors inside the ESD protection elements together, for simultaneously triggering the parasitic transistors to bypass the ESD current when the ESD occurs, thus solving the non-uniform problem of bypassing the ESD current. Moreover, the ESD protection device can be used as an output buffer to enhance the output driving ability of the core circuit. As for the layout of the ESD protection device, another doped region is added onto the substrate neighboring to the doped regions of the ESD protection elements. However, the added doped region cannot contact the doped regions of the ESD protection element, but is electrically connected thereto, so as to make the bases of the parasitic transistors coupled together without using extra layout area.
[0086] Though the present invention has been disclosed above by the preferred embodiments, they are not intended to limit the present invention. Anybody skilled in the art can make some modifications and variations without departing from the spirit and scope of the present invention. Therefore, the protecting range of the present invention falls in the appended claims.
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An electrostatic discharge (ESD) protection device and a layout thereof are provided. A bias conducting wire is mainly used to couple each base of a plurality of parasitic transistors inside ESD elements together, in order to simultaneously trigger all the parasitic transistors to bypass the ESD current, avoid the elements of a core circuit being damaged, and solve the non-uniform problem of bypassing the ESD current when ESD occurs. Furthermore, in the ESD protection layout, it only needs to add another doped region on a substrate neighboring to, but not contacting, doped regions of the ESD protection elements and use contacts to connect the added doped region, so as to couple each base of the parasitic transistors together without requiring for additional layout area.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 62/089,095, filed Dec. 8, 2014, which is incorporated by reference in its entirety.
BACKGROUND
[0002] 1. Field of the Invention
[0003] This invention relates to elongated contact pad structures.
[0004] 2. Description of the Related Art
[0005] Substrates with different coefficient of thermal expansion compared to silicon are used in three dimensional (3D) and 2.5D integrated circuits (collectively, 3DICs). Due to the difference in coefficient of thermal expansion, the substrates of the 3DICs may misalign. Furthermore, large monolithic dies with small contact bumps may also misalign from the contact pads of a substrate the monolithic die is connected to due to a mismatch om the coefficient of thermal expansion between the monolithic die and the substrate.
[0006] Thus, there is a need for an improved contact pad structure that stays aligned at room temperature, as well as at elevated temperatures.
SUMMARY
[0007] The present invention overcomes the limitations of the prior art by including an elongated pad that stays aligned at elevated temperatures. The elongation of the pads may depend on the distance between the pad and the center of the substrate.
[0008] A 3DIC includes a die and a substrate. The die includes multiple bumps to provide electrical connection to elongated pads of a substrate. Each elongated pad of the substrate corresponds to a bump of the die at a first temperature and is also aligned to the same corresponding bump at a second temperature. In some embodiments, the first temperature is room temperature and the second temperature is a solder reflow temperature.
[0009] In some embodiments, the amount of elongation of the pads is based on a position of the pad on the substrate, a mismatch between a coefficient of thermal expansion of the die and a coefficient of thermal expansion of the substrate, and/or the second temperature. Additionally, in some embodiments, the elongated pads are elongated radially from a central point of the substrate.
[0010] Other aspects include components, devices, systems, improvements, methods, processes, applications and other technologies related to the foregoing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The invention has other advantages and features which will be more readily apparent from the following detailed description of the invention and the appended claims, when taken in conjunction with the accompanying drawings, in which:
[0012] FIG. 1 is a cross sectional side view of a three dimensional integrated circuit (3DIC), according to one embodiment of the invention.
[0013] FIG. 2A (prior art) is a cross sectional view of a die and a substrate with different coefficients of thermal expansion at room temperature.
[0014] FIG. 2B (prior art) is a cross sectional view of a die and a substrate with different coefficients of thermal expansion at an elevated temperature.
[0015] FIG. 3A is a cross sectional view of a die and a substrate with elongated pads at room temperature, according to one embodiment.
[0016] FIG. 3B is a cross sectional view of a die and a substrate with elongated pads at an elevated temperature, according to one embodiment.
[0017] FIG. 4A (prior art) is a top view of a die and a substrate with different coefficients of thermal expansion at room temperature
[0018] FIG. 4B (prior art) is a top view of a die and a substrate with different coefficients of thermal expansion at an elevated temperature.
[0019] FIG. 5A is a top view of a die and a substrate with elongated pads at room temperature, according to one embodiment.
[0020] FIG. 5B is a top view of a die and a substrate with elongated pads at an elevated temperature, according to one embodiment.
[0021] FIG. 6A is a top view of a die and a substrate with elongated pads at room temperature, according to one embodiment.
[0022] FIG. 6B is a top view of a die and a substrate with elongated pads at an elevated temperature, according to one embodiment.
[0023] FIG. 7 is a flow diagram for designing the pads of a printed circuit board, according to one embodiment.
DETAILED DESCRIPTION
[0024] The Figures (FIGS.) and the following description relate to preferred embodiments by way of illustration only. It should be noted that from the following discussion, alternative embodiments of the structures and methods disclosed herein will be readily recognized as viable alternatives that may be employed without departing from the principles of what is claimed.
[0025] Reference will now be made in detail to several embodiments, examples of which are illustrated in the accompanying figures. It is noted that wherever practicable similar or like reference numbers may be used in the figures and may indicate similar or like functionality. The figures depict embodiments of the disclosed system (or method) for purposes of illustration only. Alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles described herein.
[0026] FIG. 1 is a cross sectional side view of a three dimensional (3D) and 2.5D integrated circuit (3DIC). A 3DIC typically includes a stack of alternating active chips and silicon interposers. As shown in FIG. 1 , an exemplary 3DIC may include several tiles 110 (e.g., logic, field programmable gate arrays or FPGA, memory-stacks, integrated passive devices or IPD, etc), a passive silicon interposer 120 and an organic laminate 130 . In order to route signals, one or more of these components may include thru-silicon vias (TSV).
[0027] The tiles 110 may include integrated circuits fabricated on a piece of semiconductor material. Tiles 110 may be a logic tile (e.g., a microprocessor, an application specific integrated circuit or ASIC, a field programmable gate array or FPGA), a memory tile (e.g., a random access memory or RAM, a non-volatile such a NAND flash memory) or integrated passive devices (e.g., impedance matching circuits, harmonic filters, couplers, etc.). In some embodiments, a module may be spread across multiple tiles 110 . For instance, a 1 GB RAM module may be spread across two tiles 110 , each having 512 MB RAM module.
[0028] The passive silicon interposer 120 interconnects multiple tiles 110 to each other. For instance, a silicon interposer may couple a logic tile with multiple memory tiles. The tiles connect to the silicon interposer through a microbump 115 . Microbumps 115 of the tiles 110 may be aligned to contact pads in one side of the silicon interposer 120 to form an electrical connection between the an input/output (IO) port of the tile 110 and an IO port of the silicon interposer 120 . In some embodiments, a thermal process may be used to bond the microbumps of the tiles 110 to the contact pads of the silicon interposer. For example, a solder reflow process may be used to reflow the microbumps of the tile 110 and bond the IO ports of the tiles 110 to the IO ports of the silicon interposer 120 .
[0029] The organic laminate 130 is coupled to the silicon interposer 120 through bumps 125 . The organic laminate 130 routes the signals received through bumps 125 to out of the 3DIC though solder balls 135 , and routes the signals received through solder balls 135 to the silicon interposer 120 through bumps 125 .
[0030] In some embodiments, the organic laminate 130 reduces the density of IO ports of the silicon interposer 120 . As such, the organic laminate 130 may have a larger area than the silicon interposer 120 . The organic laminate 130 may be manufactured with materials with lower cost than the material used to manufacture the silicon interposer 120 . Since the silicon interposer 120 and the organic laminates are manufactured with different materials, the silicon interposer 120 and the organic laminate 130 may have different coefficients of thermal expansion. As such, during thermal processes of the fabrication of the 3DIC and during the use of the 3DIC, the silicon interposer 120 and the organic laminate 130 will expand at different rates, which may cause misalignment between the IO ports of the silicon interposer 120 and the IO ports of the organic laminate 130 .
[0031] FIG. 2A is a cross sectional side view of a die and a substrate of a 3DIC with different coefficients of thermal expansion at room temperature and FIG. 2B is a cross sectional side view of the die and the substrate at an elevated temperature. The die 211 includes multiple bumps 215 that are aligned to the contact pads 205 of the substrate 201 . The die may, for example, be made of silicon, which has a low coefficient of thermal expansion (CTE). For instance, silicon has a CTE of about 1.5 ppm/° C. The substrate may be, for example, a printed circuit board (PCB) or an organic interposer with a higher CTE. For instance, a PCB has a CTE of that is 10 times larger than the CTE of silicon. As such, the substrate expands faster than the die.
[0032] At room temperature, the bumps 215 of the die 211 are aligned to the contact pads 205 of the substrate 201 and provide an electrical connection between the die 211 and the substrate 201 . During certain fabrication steps and/or during the use of the 3DIC, the 3DIC may be subjected to elevated temperatures. For instance during a solder reflow process of the fabrication of the 3DIC, the 3DIC may be exposed to an elevated temperature to cause the solder to melt and reflow for establishing electrical and/or mechanical connections between the different components of the 3DIC. In another example, during the use of the 3DIC, certain components of the 3DIC may dissipate power in the form of thermal energy, causing the 3DIC to heat up. When the 3DIC is exposed to an elevated temperature, the die 211 and the substrate 201 may expand in accordance with their respective CTE. Since the die 211 and the substrate 201 have different CTE, beyond a certain temperature, the bumps 215 and the pads 205 may misalign.
[0033] As shown in FIG. 2B , at an elevated temperature, due to the mismatch in the coefficient of thermal expansion, the contact pads 205 of the substrate 201 are misaligned from the bumps 215 of the die 211 . That is, when the temperature of the die 211 and the substrate 201 is elevated, the substrate experiences a larger thermal expansion than the die. For instance, the amount of linear expansion of the die 211 and the substrate 201 is as follows:
[0000] Δ L s =α s L 0 ΔT (1)
[0000] Δ L d =α d L 0 ΔT (2)
[0000] Δ L =(α s −α d ) L 0 ΔT (3)
[0034] Where ΔL s is the amount of thermal expansion experienced by the substrate 201 , ΔL d is the amount of thermal expansion experienced by the die 211 , α s is the linear CTE of the substrate 201 , α d is the linear CTE of the die 211 , L 0 is the length at room temperature, and ΔT is the change in temperature. ΔL is the difference in thermal expansion between the substrate and the die due to the difference in the CTE between the substrate and the die.
[0035] As illustrated in FIG. 2B , the misalignment is more pronounced near the edge of the substrates. That is, the bumps 215 and contact pads 205 that are near the center of the substrates 201 , 211 are still aligned at an elevated temperature, but the bumps 215 and contact pads 205 that are near the edge of the substrate are more severely misaligned.
[0036] To maintain alignment of the bumps 215 and the pads 205 at room temperature and at elevated temperature, the pads may be designed with an elongated shape. When the 3DIC is at room temperature, the bumps 215 are aligned to a first end of the elongated pad and when the 3DIC is at an elevated temperature, the bumps 215 are aligned to a second end of the elongated pad. For instance, the pads may have an oval shape or an elliptical shape.
[0037] FIG. 3A is a cross sectional side view of a die and a substrate with elongated pads at room temperature and FIG. 3B is a cross sectional side view of the die and the substrate with elongated pads at an elevated temperature. As illustrated in FIG. 3A , the contact pads 305 of the substrate are elongated. In some embodiments, the elongation of the pads may be dependent on the position of the pad. In this example, the contact pads 305 that are closer to the edge of the substrate are more elongated than the elongated contact pads 305 that are near the center of the substrate. Furthermore, the amount of elongation of the pads may further be dependent on the CTE mismatch between the die 211 and the substrate 301 , and a maximum temperature the 3DIC is expected to be exposed to.
[0038] As illustrated in FIG. 3B , since the pads are elongated, after the substrate is expanded at elevated temperatures, the elongated contact pads 305 of the substrate 301 are still aligned to the bumps 215 of the die 211 . As such, the bumps 215 of the die can be electrically connected to the elongated contact pads 305 of the substrate in an elevated temperature environment, such as during a solder reflow process. After the die 211 and the substrate 301 cool down to room temperature, the bumps 215 and the contact pads 305 would still be aligned.
[0039] As shown in FIG. 3A and FIG. 3B , at room temperature, the distance from the center of the die 211 to the center of a bump 215 A is L 0 , the distance between the center of the substrate 301 and a first end of a pad 305 A is L 0 , and the distance from the center of the substrate 301 to the second end of the pad 305 A is L 0 ′. Furthermore, at an elevated temperature, the distance from the center of the die 211 to the center of the bump 215 A is L 0 +ΔL d and the distance from the center of the substrate 301 to the second end of the pad 305 A is L 0 ′+ΔL s . Since, at the elevated temperature, the second end of the pad 305 A is aligned to the bump 215 A:
[0000] L 0 +ΔL d =L 0 ′+ΔL s (4)
[0000] which can be re-written as:
[0000]
L
0
+
α
d
L
0
Δ
T
=
L
0
′
+
α
s
L
0
′
Δ
T
(
5
)
Thus
:
L
0
′
=
L
0
1
+
α
d
Δ
T
1
+
α
s
Δ
T
(
6
)
[0040] FIG. 4A is a top view of a die and a substrate with different coefficients of thermal expansion at room temperature, and FIG. 4B is a top view of the die and the substrate at an elevated temperature. In FIG. 4B , the dotted lines represent the die 211 with a lower CTE and the solid lines represent the substrate 201 with a higher CTE. As illustrated in FIG. 4A , the bumps 215 of the die 211 and the pads 205 of the substrate 201 are designed to be aligned at room temperature (so they are overlapping in FIG. 4A ). Due to the mismatch in CTE, as shown in FIG. 4B , the substrate 201 expands more than the die 211 and thus, the bumps 215 of the die 211 are mis-aligned from the pads 205 of the substrate.
[0041] FIG. 5A is a top view of a die and a substrate with elongated pads at room temperature and FIG. 5B is a top view of a die and a substrate with elongated pads at an elevated temperature, according to one embodiment. As illustrated in FIG. 5A , the bumps 215 of the die 211 are aligned, at room temperature, to the elongated contact pads 305 of the substrate 301 . In one embodiment, the bumps 215 of the die 211 are designed to be aligned near a first end of the elongated contact pads 305 of the substrate 301 . When the substrate 301 expands due to an elevated temperature, the bumps 215 of the die 211 stayed aligned to the elongated contact pads 305 of the substrate 301 . In one embodiment, the pads are designed to be aligned to the bumps 215 of the die 211 , at an elevated temperature, at near a second end of the elongated contact pads 305 , opposite to the first end.
[0042] In some embodiments, the pads 305 are elongated in the direction of expansion of the substrate 301 . For instance, the pads 305 are elongated radially from the center of the substrate 301 . In another example, the pads 305 are elongated radially from a point other than the center of the substrate.
[0043] In some embodiments, pads 305 that are closer to the center of the substrate have a smaller elongation than pads that are further away from the center of the substrate. In other embodiments, pads 305 that are closer to the center of the substrate have a smaller area than pads 305 that are further away from the center of the substrate.
[0044] FIG. 6A is a top view of a die and a substrate with elongated pads at room temperature and FIG. 6B is a top view of a die and a substrate with elongated pads at an elevated temperature, according to another embodiment. In the embodiment of FIG. 6 , the elongated contact pads 305 of the substrate 301 have a circular shape. The size of the elongated contact pads 305 are based on the distance of the pad 305 to the center of the substrate. Elongated contact pads 305 that are further from the center of the substrate are larger than elongated contact pads 305 that are closer to the center of the substrate. In other embodiments, other shapes, such as hexagonal shapes, may be used for the elongated contact pads 305 .
[0045] FIG. 7 is a flow diagram for designing the elongated pads of a printed circuit board, according to one embodiment. A contact pad layout at room temperature is received 701 . The contact pad layout is resized 703 based on the CTE of the substrate 301 and the elevated temperature. Base on the contact pad layout at room temperature and the resized contact pad layout, an elongated pad layout is determined 705 .
[0046] Although the detailed description contains many specifics, these should not be construed as limiting the scope of the invention but merely as illustrating different examples and aspects of the invention. It should be appreciated that the scope of the invention includes other embodiments not discussed in detail above. Various modifications, changes, and variations which will be apparent to those skilled in the art may be made in the arrangement, operation, and details of the method and apparatus of the present invention disclosed herein without departing from the spirit and scope of the invention as defined in the appended claims. Therefore, the scope of the invention should be determined by the appended claims and their legal equivalents. Furthermore, no element, component or method step is intended to be dedicated to the public regardless of whether the element, component or method step is explicitly recited in the claims.
[0047] In the claims, reference to an element in the singular is not intended to mean “one and only one” unless explicitly stated, but rather is meant to mean “one or more.” In addition, it is not necessary for a device or method to address every problem that is solvable by different embodiments of the invention in order to be encompassed by the claims.
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A 3DIC includes a die and a substrate. The die includes multiple bumps to provide electrical connection the substrate. The substrate includes multiple elongated contact pads. The elongated contact pads making electrical contact with the bumps and shaped to maintain alignment with the bumps over a temperature range.
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This application is a continuation-in-part of U.S. application Ser. No. 035,268, filed Apr. 2, 1987.
BACKGROUND OF THE INVENTION
This invention relates to the compressive treatment of webs in which a stationary retarding surface acts upon the outer surface of a driven web to cause the web to slow and longitudinally compact or crepe in a treatment zone. This technique, sometimes referred to as bladeless microcreping because of its avoidance of the use of a blade retarder and its ability to produce fine crepes, is exemplified by our prior U.S. Pat. No. 3,810,280, which is herein incorporated by reference.
With this bladeless technique it has been found difficult to obtain the desired level of uniformity of treatment under commercial conditions and at commercial speeds. For example, as speeds have been increased, unwanted non-uniformities have occurred across the width of the web in some cases or in the longitudinal direction, or the characteristics resulting from the treatment have been different over the range of operational speeds. In other cases the characteristics that result from the treatment have been sensitive to slight change in temperature or adjustment, making the technique inappropriate for commercial adoption. In some cases, prior implementations of the bladeless technique have caused snagging or surface abrasion or other harm to the web.
For such reasons the commercial use of this technique has been limited, despite its potential advantages and the importance of the possible fields of application. An example of an important field is that of denim fabrics, in which mechanical treatment by the technique, if perfected, has wide potential. Another example is the field of specialty fabrics, where mechanical treatment is desired for giving to rather inexpensive or low quality fabrics, characteristics that enhance their value and quality.
The bladeless technique is applicable to compaction of webs in which components of the web, e.g. a knit or woven material, are longitudinally compacted with extreme uniformity and without introduction of crepe, and to various degrees of creping, from the finest microcrepe to rather gross crepe, or combinations of primary and secondary crepes or decorative effects. In some cases tension is applied to the treated web to remove some or even most of the treatment, e.g. where it is desired mainly to soften the web or render it pliable. In addition to textile fabrics the technique is applicable to a wide range of nonwoven fabrics, papers and other web-form flexible sheets and the like.
Various aspects of the present invention are believed to meet, in a commercially practical manner, the needs mentioned above as well as others that are encountered in the longitudinal compressive treatment of webs.
Certain aspects of the invention are applicable to other web treatment machines besides the bladeless microcreper.
SUMMARY OF THE INVENTION
One aspect of the invention relates to a web treating machine and method employing a drive member having a web-gripping drive surface, a smooth surfaced primary member arranged over the drive member to press the web into driven engagement with the surface of the drive member, and a generally stationary retarding surface arranged after the primary surface to engage and retard the web before the web has left the drive member, the retarding surface being supported by a sheet form support member. According to this aspect of the invention, the sheet form support member is elastically deflectable, a tip deflector is constructed and arranged to apply deflecting pressure on the downstream end portion of the support member to deflect the support member toward the drive member, there being a cavity stabilizer in the form of a second sheet form member which extends in face to-face reinforcing relationship over the initial portion of the support member in the region immediately downstream of the primary member, the portion of the support member extending between the cavity stabilizer and the tip deflector being relatively unreinforced.
In one important category of embodiments, the web gripping drive surface is of curved form, as provided by the surface of a cylindrical roll, or a belt travelling over a roll, and the sheet form support member is elastically deflectable about the curved drive surface by applied tip pressure from a relatively straight unstressed shape to a bowed, elastically deformed shape that generally conforms to the curvature of the drive surface.
Preferred embodiments of these aspects of the invention have the following features.
The tip deflector is comprised of a sheet spring member in face-to face engagement with the upper surface of the end portion of the support member. The tip deflector and the cavity stabilizer comprise spaced apart portions of a supplemental sheet spring member, the portion of the supplemental sheet spring member that defines the tip deflector being in face-to-face engagement with the upper surface of the end portion of the support member. The supplemental sheet spring member has, in unstressed condition, a precurved, outwardly convex portion spanning between the portions that define the cavity stabilizer and the tip deflector. The primary member is of sheet form, an extension of the supplemental sheet spring member extends upstream of the portion that defines the cavity stabilizer, the extension lying over the primary member, and a presser member presses the extension downwardly whereby the extension in turn can press the primary member downwardly into engagement with the web, the members constructed and arranged such that the downward pressure of the presser member serves to urge the tip deflector and the cavity stabilizer portions of the supplemental sheet spring member into engagement with respective portions of the support member.
In unstressed condition, the upstream extension of the supplemental sheet member is precurved, outwardly convex over a region immediately upstream of the presser member, as a continuation of the curve of the supplemental member downstream of the presser member. The presser member comprises a presser edge that extends in the direction perpendicular to the direction of treatment, in the case where the shape of the drive surface is defined by a roll, the presser edge extending in the direction of the length of the roll. And the supplemental sheet spring member is constructed and arranged so that in operating position the presser member locally, elastically deflects the sheet spring member into a slightly reversely curved, outwardly concave form whereby in the region of the presser member and immediately upstream and downstream thereof, the sheet spring member has a stable prestressed, generally gull-wing shape.
Preferred embodiments of various aspects of the invention also have the following features.
The primary member comprises a sheet metal member, and upstream extensions of the primary member, the support member and the supplemental sheet spring member extend upstream to a common holder which grips them face-to-face. Useful e.g. where the driven member is a roll having a diameter of the order of twelve inches or greater, the support member is of blue steel having thickness greater than about 0.010 inch. The thickness of the support member is less than about 0.020 inch. A supplemental sheet form member forms the tip deflector and cavity stabilizer, the supplemental sheet form member being of blue steel and thickness greater than about 0.010 inch and no thicker than about the thickness of the support member. A smooth sheet form, low-friction roof member extends downstream a limited distance from the end of the primary member to the effective beginning of the retarding surface. The roof member is comprises of blue steel of a sheet of about 0.003 inch thickness and extends downstream from the end of the primary member no more than about one half inch. The retarding surface commences at the end of the primary member. The retarding surface has an effective downstream extent of between about 1/2 and 11/2 inches. The retarding surface is defined by an emery sheet lying below the support member. The retarding surface is formed integrally with the under surface of the support member. The retarding surface comprises a large multiplicity of successive ridges and grooves set acutely to the machine direction and preferably having a non-harmful low friction surface such as polished metal. For producing a tree bark effect or the like, including plisses, a widthwise distribution of interruptions of a surface is provided in the region of the treatment cavity, e.g. open space in the retarding surface such as holes, slits or slots in emery cloth that provides the retarding surface, or deformations in the end of the primary member.
Another aspect of the invention relates to a web treating machine and method employing a drive member having a web-gripping drive surface, a smooth-surfaced sheet-form primary member arranged over the drive member to press the web into driven engagement with the drive surface, a presser member defining a presser edge for pressing the primary member against the drive member and a generally stationary retarding surface arranged after the primary surface to engage and retard the web before the web has left the drive member, the retarding surface being supported by a sheet spring member which has a rearward portion extending rearwardly over the primary member and under the presser member. According to this aspect of the invention, the sheet spring member has, in unstressed condition, a precurved, outwardly convex portion spanning between a point upstream of the presser member edge to a region substantially downstream of the edge, the sheet spring member being constructed and arranged so that in operating position, the presser member locally elastically deflects the sheet spring member into a slightly reversely curved, outwardly concave form whereby in the region of the presser member and immediately upstream and downstream thereof the spring member has a stable prestressed generally gull-wing shape.
Preferred embodiments of this aspect of the invention have the following features.
In the operative position, spaced upstream of the presser member, the sheet spring member is bowed out of contact with the primary member as a result of the gull-wing shape. In operative position, immediately downstream of the presser member, the end of the primary member is reinforced against upward deflection by engagement of an upwardly concave portion of the gull-wing shape. In operative position the portion of the sheet spring member in the region of the tip of the primary member and immediately beyond is under a bend-resistant prestressed condition as a result of the gull-wing formation, thereby being resistant to deflection by deflection forces applied to the downstream tip of the sheet spring member. A sheet-form support member lies between the primary member and the sheet spring member, the sheet form support member extending downstream of the tip of the primary member to define a treatment cavity and the sheet spring member immediately beyond the primary member engaging the upper surface of the support member in reinforcing relation to resist change in the depth of the cavity at the end of the primary member. The sheet spring member is exposed to directly support a retarding surface. The retarding surface is defined by emery cloth extending below the sheet spring member. The retarding surface is defined by an abrasive coating carried on the under surface of the sheet spring member. The retarding surface is defined by a large multiplicity of successive ridges and grooves set at acute angle to the machine direction and preferably having a non-harmful surface formed of polished metal.
DESCRIPTION OF DRAWINGS
In the drawings:
FIG. 1 is a perspective view, partly broken away, of a preferred embodiment of a machine according to the invention in operative position;
FIG. 1a is a view, similar to FIG. 1, of the machine, with the head in a retracted, non-operative position;
FIGS. 2, 2a, 2b and 2c show four successive positions of the head of the machine as it moves from retracted position to its operative position while FIG. 2d shows the gull-wing form spring element in isolation and FIG. 2e is a magnified view of the presser region of the machine of FIG. 1 while FIG. 2f is a similar view of an embodiment with a roof;
FIG. 3 is a view similar to FIG. 2c, set up to provide a creping treatment to a web using as a retarder surface a plasma-coated surface applied to the underside of a sheet metal spring member;
FIG. 4 is a view similar to FIG. 3 of a machine employing an emery-sheet retarder; FIG. 4a is a magnified view of a portion of FIG. 4 and also showing holes formed in the emery while FIG. 4b is a plan view of such emery sheet with holes;
FIG. 4c is a plan view based upon a photograph, showing a tree bark pattern in the textile web treated according to FIG. 4a;
FIG. 5 is a view similar to FIG. 3 of an embodiment employing a grooved and ribbed retarding surface while FIG. 5a is a plan view of the surface of such retarding member and FIG. 5b is a perspective, partially cut away view showing the primary and retarder package used in the embodiment of FIG. 5;
FIG. 6 is a view similar to FIG. 3 showing an arrangement using the gull-wing form sheet spring member as the support of a retarding surface to produce a tree bark effect;
FIG. 7 is a perspective view of another sheet spring package useful according to the invention;
FIG. 8 is a view similar to FIG. 2a of another embodiment embodying two cantilevered, precurved supplemental sheet spring members while FIG. 8a, similar to FIG. 2c, shows the embodiment in operative condition;
FIG. 9 is a view similar to FIG. 2a of yet another embodiment employing a different combination of two precurved supplemental sheet spring members, while FIG. 9a, similar to FIG. 2c, shows its operative condition;
FIG. 10 is a diagrammatical plan view on a magnified scale of a critical portion of the compressive treatment cavity of an improved microcreper machine;
FIG. 11 is a view similar to FIG. 10 on an even more magnified scale;
FIG. 12 is a plan view of the novel retarding element of this embodiment featuring parallel retarder ridges set at an acute angle that act upon the face of the material to retard it by an angled opposing effect, the outline of the path of the fabric past the retarding element also being shown;
FIG. 13 is a perspective view on a magnified scale of a portion of the retarding element of FIG. 12; and
FIGS. 14 and 15 are views similar to FIG. 13 of alternate embodiments of the retarding element.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to FIGS. 1 and 2 a rotatable driven steel roll 10 has a web-gripping surface 12 provided by fine carbide particles applied by plasma coating. The roll, of e.g. 12 inch diameter, contains thermostatically controlled internal heaters denoted schematically at 13.
An assembly 16 of sheet form members is mounted in a holder 14 and extends forward, in cantilever fashion. The assembly passes under presser member 18 and over roll surface 12 where it engages the outer surface of web 20 on the roll.
From the bottom up, assembly 16 consists of a primary member 22, a sheet-form spring member 24 which supports a retarding surface 25, and a second sheet-form spring member 26 of specially curved form.
More particularly, primary member 22 has a smooth under-surface and is arranged, by the influence of presser member edge 18', to press web 20 into driven engagement with the surface 12 of driven roll 10. The downstream edge 22' of primary member 22 lies slightly downstream from alignment with presser member edge 18'. The thickness of the primary member 22 will vary depending upon the nature of the web to be treated and the type of treatment desired. Whereas it may be 0.010 inch thick and reduced by grinding to a much lesser thickness in its edge region when compaction is desired under the final margin of the primary member, it may be of much greater thickness, for instance, 0.030 or 0.040 inch and made up, e.g. of a number of overlying sheet spring members, when it is desired to define a creping cavity of that dimension just beyond the end of the primary member.
The sheet-form spring member 24, in unstressed condition, is a straight planar member, of thickness selected on the basis of being deflectable by pressure applied at its tip to elastically conform to the curvature of the roll. It is also capable of spanning over a selected, relatively unsupported length to provide resilient engagement with the web without adversely deforming or "bubbling" under outward pressure exerted by the web. For retarding passages having a length of about one half to one inch, and for a roll of 12 inch diameter, operating under usual commercial operating conditions, this first planar sheet spring member, when of blue steel, should be of thickness no less than about 0.010 inch, and may range up to about 0.020 inch for commercial conditions in which extreme ruggedness is required. For certain other operating conditions where less demand is placed upon the support member 24, the requirements can be relaxed, e.g. for a web that is soft and requires little treatment force or where secondary or irregular crepes are to be formed.
In the embodiment of FIG. 1 a retarding surface is provided as an integral layer of fine carbide particles applied by plasma coating to the undersurface of this first spring member 24.
The second spring member, in unstressed condition (see FIG. 1a), has a special precurved shape. Starting at a point lying well behind the point of alignment with the presser member edge 18', the sheet member in unstressed condition has an outwardly convex curvature, extending to its tip. This curvature is less than that of the roll, in the present example the radius being about two inches. The thickness of this member is selected to enable the member to be deflectable under operational loading to provide treatment cavity stabilization and tip loading of the first spring member in the manner to be described, while allowing a span of the first member between these two regions to be relatively unsupported. It is preferred in most instances that this second member be of substance no stiffer than the first member. For the example at hand, using a 12 inch diameter roll and a retarding passage of 1/2 inch to 1 inch length, where the second member is of blue steel, this second supplemental member generally has a minimum thickness of about 0.010 inch and does not substantially exceed the thickness of the first member.
The sequence of FIGS. 2 to 2c shows the assembled relationship of the sheet-form members and their progressive elastic deformation as the head of the machine is lowered into operative position.
As shown in FIG. 2, all three sheet form members are clamped face-to-face by holder clamp 14, with the free end of the precurved, second sheet spring 26 engaged upon the first spring member 24 near the free tip of the latter. As a result of this clamping, some pressure is applied between the members, causing the first member 24 and the primary member 22 to be slightly deflected, as shown, form their original unstressed planar condition.
To reach the operative condition, the head, comprising the presser member 18, and its support 19, the holder 14 and the clamped assembly 16, are rotated as a unit by pneumatic actuators, not shown, through the positions of FIGS. 2a and 2b to the operative position of FIG. 2c.
FIG. 2a shows the primary member just as it engages web 20 on roll 10, with no change from FIG. 2 in the shape or stress of the sheet spring members.
FIG. 2b shows the subsequent condition in which the presser member edge 18' has commenced deforming the second spring member 26, to cause local reversal of its curvature into a gull-wing formation. At this point the deformed portion of the second spring 26 has not yet contacted the first spring member 24.
FIG. 2c and the magnified view of FIG. 2e show the result of further rotation of the head in which pressure of the presser member 18' is transmitted to the primary member 22. There is solid contact under edge 18' between the second member 26 and the first member 24, the first member 24 and the primary member 22, and the primary member 22 and the web 20. The first member is bowed convexly and conforms well to the roll, as a result of pressure applied to its tip region by the cantilevered end of spring member 25. Due to the preformed curvature of second member 26, a gull-wing formation is elastically imposed on the second member 26, see also FIG. 2d which shows the gull-wing formation in isolation. In the region of the end of primary member 22, the downwardly deformed part of the gull-wing formation engages the first member 24 face-to-face, region G, whereas downstream from there, over a spanning portion, S, toward the tip, the second spring member 26 does not provide the support to member 24 that it does upstream.
After the position of FIG. 2c is reached, pneumatic pressure on the actuators for the head is increased to operative level, which is selected depending upon the nature of the particular web to be driven and the nature of the treatment to be performed. A web more difficult to drive and retard requires more pressure of presser member than weaker webs. As some of the figures suggest, the web in the region of the presser is vertically compressed. Knits demonstrate this very substantially (e.g. a jersey knit may compress from 0.016 inch to 0.007 inch or sweat shirt knit from 0.070 to 0.030 inch), but all webs are compressed to some degree.
Referring to FIG. 2f, in certain instances, e.g. for soft fuzzy fabrics, a roof member 21 of, e.g., 0.003 inch is interposed between the primary member 22 and the support member 21 so that the web, as it emerges into the cavity at the end of the primary member, is bounded by a smooth surface rather than by a retarding surface. The roof may be as long as 1/2 inch. Following the roof, the web is then exposed to the retarding surface.
FIG. 3 represents an operative condition for creping a web. This process may be started slowly and then sped up to commercial production speeds. The dynamic conditions at higher speeds may tend to cause flutter in the downstream end of the member 24, but significant spring resistance applied at the tip by a second spring member 26 opposes this movement. Furthermore any tendency for the tip of member 24 to be raised does not propogate rearwardly, by what might be termined alligator jaw effect, to open unduly the treatment cavity at the immediate end of the primary member 22. Such opening is effectively resisted by a cavity-stabilizing effect produced by face-to-face contact of the gull-wing portion of the second spring member 26 in the region G. This stabilization is quite important because undue change in dimensions of the treatment cavity, whether of periodic nature associated with a flutter condition of the retarder or of a more constant but speed dependent nature, can have unacceptable effects upon the treatment. Similarly the downstream tip of the primary member is stabilized against adverse lifting effects applied on the downstream members.
Furthermore if take up tension applied to the web begins removing the treated material at too great a rate from the retarding passage, the closing down of the tip of member 24 under the influence of the tip loading of member 26, resists such tendency, ensuring that the retarding passage remains adequately filled.
Along the span S between the tip region and the stabilized cavity, the first member 24 retains a beneficial degree of outward resiliency, so that the material may work its way along under the retarding surface as a result of the driving force applied to the web by the driven roll. The resiliency of member 24 allows slight accomodating changes in the depth of the passageway in response to the web, so that slight variations in the thickness of the web can be accomodated without causing significant variation in the treatment condition.
As the overall result, the technique can produce very uniform treatment over a wide range of speeds while accommodating inherent variations in production conditions. This is achievable using elements which are quite rugged and which, after proper selection for the treatment at hand, require no adjustments of any of the elements in the lengthwise direction of the machine.
It is possible in certain instances to have the preformed curve of the second spring member begin at or after the presser member edge. But in many instances this is not nearly so advantageous as the illustrated form, in which the curve begins well behind the presser member. The gull-wing shape that results appears to impart a stronger stabilizing effect to the treatment cavity, perhaps as a result of greater prestress and structural stability in the inflection region of the sheet metal member where a transition occurs between opposite forms of curvature. To the rear of the presser member the upward bowing of the second member out of contact with the first spring member may also avoid imposing too great rigidity on the primary member. Thus, for instance, an ironing effect upon the web can be avoided, which could be detrimental to certain desired commercial treatments.
The embodiment of FIG. 4 is similar to that of FIG. 3 except that the retarding surface is provided by a sheet of emery cloth 23 which lies beneath the first spring sheet member 24, in a supported relationship. The emery is gripped upstream between the first spring member 24 and the primary member 22.
FIG. 4a is similar to FIG. 4 except that disruptions in the form of holes 50 (and see FIG. 4b) are provided in the emery cloth at the end of the primary member for production of a tree bark effect in a textile web 20, as illustrated in FIG. 4c.
Contrary to a common desire to have well-defined, completely continuous crepes or ridges in a textile fabric, the tree bark effect is characterized by a somewhat random widthwise discontinuity of the crepe formations, in which certain crepe formations end and others begin, and still others merge or branch. An acceptable product must, over all, have a generally uniform appearance so that while randomly distributed, the general frequency and nature of the discontinuities must be uniform.
Such a tree bark effect has previously been produced in textiles at high temperature (e.g. 400° F.) and at slow speed (e.g. 10 yards per minute) on a limited commercial basis using a so-called bladed microcreper, but not at desired lower temperatures and much higher speeds. Aspects of the present invention are seen as making possible tree bark at higher commercial speeds.
To produce the tree bark effect an enlarged cavity is provided, chosen with respect to the particular fabric to be not so large as to induce secondary or superficial crepe upon previously formed crepe. Whereas the size of the cavity can often be chosen, for a particular speed, to produce the desired result, cavity sizing alone may be inadequate to assure production of the same tree bark effect over a wide range of speeds or other operating conditions. It has been found however that localized disruptions in the treatment cavity, such as produced by the holes 50 in the emery sheet at the end 22' of the primary member 22 introduce desired localized disturbances to the retarding action. These initiate the desired discontinuities in the creping action, to produce tree bark over a usefully widened range of operating conditions.
Other means of introducing discontinuities are possible, for instance, by localized deformations in the end of the primary member or by narrow slots (or even slits) formed in the emery sheet, lying at an acute angle of e.g. 20° to the machine direction. The angled relationship of the slots ensure that all portions of the web traverse some retarding surface so that striations or other linear artifacts in the treated web, in the machine direction, when not wanted, can be avoided.
The embodiment of FIG. 5 employs a sheet metal retarding member 43 having a dense series of angled ridges 45 and grooves 47 as shown in FIG. 5a, assembled in the package shown in FIG. 5b. The ridges and grooves may be formed of non-abrasive material such as polished steel. Depending upon the treatment cavity geometry and the angle chosen for these ridges and grooves it is possible for such a retarder surface to induce desired discontinuities as the web "ratchets" over the ridges and grooves, to produce a desired tree bark effect.
Of more general interest, the ridges and grooves produce a retarding effect by back-pressure caused by angled opposition to the forward travel of the web produced by the ridges. With certain amenable materials, such as knit fabrics, the idges and grooves are arranged to channel the web to move bodily in the angled direction of the ridges to produce the needed resistive pack of creped or compacted material at the treatment cavity, against which the oncoming fresh material can be longitudinally compressed, thus avoiding any abrasion to the web.
These and other features and advantages of such a bias retarding device are disclosed in copending U.S. Patent application Ser. No. 035,268, filed Apr. 2, 1987, which is hereby incorporated by reference.
In FIG. 6 another means of forming a tree bark effect is shown. In this case a retarding surface 25' of carbide particles is applied to the under surface of the second spring member 26 while the first spring member is omitted from the package. The relatively large nature of the crepes and the fact that a certain degree of irregularity of treatment is desired make it possible in this case to omit the first spring member.
The package illustrated in FIG. 7 employs a second spring sheet 26' which has a series of machine direction slits 27 in its trailing edge. These introduce a certain responsiveness o the second sheet member to local conditions under the retarding surface, in some cases facilitating the smooth flow of the process.
In the embodiment of FIGS. 8, 8a, two precurved supplemental spring members 30 and 32 are supported in cantilever fashion by holder 14. The shorter member 30 has its tip in the region immediately downstream of the end of the primary member 22, and serves, in operative position (FIG. 8a) to provide stabilization to the treatment cavity. The longer member 32 has its tip engaged upon the downstream end of the first sheet spring member, and causes the latter's deflection about the roll.
In the embodiment of FIGS. 9, 9a a short precurved member 42 is landed on opposite ends of the portion of the first support spring 24, to provide, respectively, cavity stabilization and tip deflection. The second precurved member 40 extends from its cantilevered support to the mid region of the short member 42, to apply deflecting pressure in response to the presser member edge 18'.
In the embodiments of FIGS. 8a and 9a it is seen that there is a span S between stabilized treatment cavity and tip, in which the first sheet spring member is relatively unsupported, and free to provide a degree of resilient support to the confined web traveling beneath it.
Although presently preferred embodiments, e.g. FIGS. 1, 8 and 9, employ a curved driving roll, it will be understood that many aspects of the invention including the gull-wing feature and alternative arrangements such as those of FIGS. 8 and 9, are applicable to a moving web-driving belt having an appropriate driving surface. The web compressing action may take place at the location of a guide roll, in which case the belt has the curved form of its guide, or in some advantageous cases the action may occur at a point where the belt is flat. In the latter case, a back support may be employed under the moving flat belt where the belt itself does not offer sufficient stability. One use for such a belt is the creping of a web on the bias, in which case the presser edge may be arranged at an angle to the direction of travel of the belt.
Because of the ability of the foregoing gull wing and other features to make commercial operations feasible, certain ridge and groove retarding techniques that we have developed gain new importance. These will be described now in detail.
We previously showed such a retarder in FIG. 5.
Referring now to FIGS. 10, 11, 12 and 13, the retarder member 40 has a special web engaging surface comprised of a series of relatively closely spaced retarding ridges 46 separated by groove passages 48. In most preferred embodiments the ridges are comprised of hard, smooth, polished substance, e.g. hardened spring steel, upon which the web material can readily slide. The leading edges E L of these ridges, which are opposed to the movement of the oncoming web, do the major work.
In the embodiment shown, the ridge and groove configuration is formed by sequential grinding of the face of a blue steel sheet with a narrow diamond grinding wheel, or alternately they ma be formed by etching. In either case the edges are formed by the intersection of two different surfaces, as shown being a substantially planar top surface of a ridge and a side surface of a ridge, so that the resultant edge E L has a web-surface-indenting capability. The ridges and grooves extend at angle a relative to the machine direction S, angle a varying in value from about 10° to about 60° (often preferably between 30°, preferred for stiff webs, and 45°, preferred for soft, flexible webs) depending upon the nature of the material to be treated and the properties desired to be achieved by the treatment. In the embodiment shown in FIGS. 10-13, angle a is 45°.
Referring to FIG. 13, the blue steel is of thickness, t, of 0.020 inch. The grooves are formed to a depth, d, sufficient to ensure that the leading edge E L of each ridge 46 is sharp, depth, d, typically being 0.010 inch. In the embodiment shown grooves 48 have widths W g of 0.040 inch. These grooves are formed on 0.050 inch centers, giving a ridge width W r of 0.010 inch. The ridges 46 and grooves 48 extend across the full width of the web 16 and have a density, in this embodiment, sufficient to produce a uniform treatment of a wide variety of web materials. In the embodiments shown, the ridges and grooves extend to the downstream extremity of the retarding member.
As shown in FIG. 10, 11, and 12, with amenable webs, such as knit fabrics, the web which moves under the primary member 18 in the machine direction S, is diverted to direction R during its travel under the retarding member 40, is drawn off of the machine from under the end of the retarding member in machine direction S, as is shown in solid lines in FIGS. 12, and is wound upon a roll. In an alternate embodiment, as suggested in dotted lines in FIG. 12, the web may be withdrawn at an angle S' from the machine direction, an angle which may correspond to the direction of the ridges, or may be at less of an angle to the machine direction, depending upon the nature of the treatment desired.
The leading edge E L of each of the ridges 46 faces into the incoming material and its initial part P i is effective to apply a retarding force to the web. Referring to FIG. 10 and 11, any web segment, as it reaches a leading edge E L , encounters a resistance force F R normal to the direction of extent of the resistance edge E L . This force F R can be resolved into a force component F S which acts in opposition to the machine direction feed of the material and a diverting force component F D which acts in the direction at right angles thereto. F D tends to divert the web from the direction S to direction R, at angle a of the ridges and grooves. This interaction of the web with the resistant edges E L is repeated at every increment of 0.050 inch across the width of the material, with the aggregate result that the entire web is bodily transformed from movement in the machine direction S to the temporary direction R set at angle a.
It appears, as suggested in FIG. 11, that the resistance force F R has decreasing effect on the web as the web contacts edge E L further from initial point P i , due, perhaps, to the combined effect of all the edges E L on the oncoming web.
Since it is generally the leading edges E L of the retarding member that do the major work (and not the second or lazy edge on the other side of the ridge), it can be readily appreciated that other forms of a retarding surface can be employed. For instance, referring to FIG. 14, the retarding edges E L may be machined into a plate in the nature of a "checkmark" cross section in which the surface of the retarding member slopes at 43 from each edge E L at an angle b to the plane of extent of the retarding member 40'. The slope ends at the step surface h which rises to form the next retarding edge E L , this being repeated across the full surface of the retarding member. In FIG. 15 an escalloped cross section is shown, with curved resistant edges E L formed by the intersection of adjacent concavely curved surfaces 45.
Operation of Embodiment of FIGS. 10-13
The web 20, as shown in FIG. 1, proceeds from a supply roll at the speed S of the driven roll 10. Initially, to start the action, the web is laid beneath the primary member 22 and retarding member 40 in untreated position and presser member 18 is pressed downwardly to press the primary member 22 against the web 20. This causes the roll 10 to drive the web forward. Retarding of the web is initiated to cause a "build back" of a column of compressively treated web by the action of primary member 22 and retarding member 40 on the web or by the operator by hand. Thus, the condition of FIG. 5 is achieved during start-up. The operator quickly releases the temporary pressure, if applied, and the retarding member thereafter can perform its retarding function without need of pressure beyond that provided by the set up shown. As the fresh web 20 reaches the treatment cavity (which may be under the primary or at its end), each element of web 20 is subjected to a forward driving force due to the action of the roll and a backward retarding force. At this point an initial compressive treatment occurs and the treated web slips on the roll 10. In the case of thin webs subject to creping such as tissue paper or nonwovens, an initial, extremely fine microcrepe may be formed, which may be only a few thousandths of an inch in height. In the case of textiles, compaction occurs with microcreping of component fibers, without creping of the overall fabric. As the driven roll continues to turn, this web reaches the end 22' of the primary member 22. At this point the web is free to expand or bloom (as with textiles) or crepe (as with paper) into coarser crepe in the treatment cavity whose height is determined by the thickness of the primary member. In either event the face of the material extends somewhat into the grooves 48, while the ridges 46, or at least the leading edges E L , bear into the surface of the microcreped material to apply the retarding forces described in FIG. 11. The set of diverting forces F D at the leading edges E L of all of the ridges has the aggregate effect of diverting the web to move in the direction of the grooves, R, as a column of compressed material, proceeding at speed slower than that of the roll 10. The roll surface slips beneath the treated material. The drive forces of the roll as well as certain drag effects of the roll slipping beneath the treated web advance the web through the grooves 48 in channelled flow until the web is released from the retarding member 40. At that point, as shown in FIG. 12 in solid lines, and as well in FIG. 16, the treated web is wound up by roll 32 which pulls the web in direction S, in a path that is offset by distance D as shown in FIG. 16 due to the diverted movement of the web.
In the treatment of a thin polyester tricot knit fabric of approximately 0.015 inch thickness, the web goes through a number of stages, i.e. drive, treatment, retarding, setting and windup. The knit fabric as it is led in has lines of knit extending in parallel, perpendicular to the machine direction S. These lines of knit never turn. Even in the retarding region, they remain parallel in the crosswise direction. As the web is driven forward it undergoes a compressive treatment. The compressed web readily expands, being soft and pliable, and fills the grooves 48. Because of the smooth surface of the grooves and ridges, the web remains uniform, without picks or abrasion. It is drawn off in the direction S, as previously mentioned, and passes through a cooling region.
The compressive treatment causes the fibers of the polyester to bloom and makes the fabric much softer to the touch and more drapable while the cooling region sets this treatment.
It will be further appreciated that other variations in the use of the invention can be employed. The ridges and grooves can be curved (FIG. 15) instead of straight and may even have re-entrant curves of S form or zigzag configuration to some extent, all for the retarding purposes described above. For variation in the treatment across the width of the web, it should be noted that in certain materials, and with suitable arrangements of the retarding ridges, the highest degree of compaction can occur immediately adjacent retarding edge E L while in a wide groove adjacent to this ridge a region, remote from the retarding edge E L (e.g. next to the lazy edge in FIG. 10) can have less compressional pressure applied and less permanent compression effects. The resulting web can have, where desired, a gradation of treatment. The treatment over wide lands is another example where a differing kind of treatment can be provided. In many instances the web is subjected to twisting and shear effects in its own plane in a manner very unusual, resulting in greater softening and other desired effects.
It will be understood that numerous further embodiments not illustrated here can employ features of the present invention. The web driving surface might be a roll having grooves such as those illustrated in Packard U.S. Pat. No. 4,090,385, or indeed might be provided by a belt traveling over a support roll or over a flat support as mentioned above. Of particular worth to mention is the ability to achieve plisse effects in finely treated fabrics using suitable interruptions of the retarder surface or the primary member at places across the width of the machine.
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A web treating machine and method employing a web-gripping drive surface, a primary member that presses the web against the drive surface, and a stationary retarding surface, supported by a sheet form member, that retards the web before it leaves the drive surface, has the following of features. The sheet form support member is elastically deflectable. A tip deflector applies deflecting pressure on the downstream end of the support member to deflect the support member toward the drive member. A cavity stabilizer, in the form of a second sheet form member, extends in face-to-face reinforcing relationship over the initial portion of the support member in the region immediately downstream of the primary member, the portion of the support member extending between the cavity stabilizer and the tip deflector being relatively unreinforced. The cavity stabilization and tip deflection is obtained by deflection of various spring members, in one instance an advantageous gull-wing form being achieved. Both curved and flat web-driving surfaces are employed. The support member is elastically deflectable about the curved drive surface by applied tip pressure from a relatively straight unstressed shape to a bowed, elastically deformed shape that generally conforms to the curvature of the drive surface. Retarding surfaces shown include sets of ridges and grooves angled to the direction of web drive. Special formations of the retarding surfaces achieve special effects such as a tree bark appearance.
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BACKGROUND OF THE INVENTION
The present invention relates to a vane-type motor or pump including a rotor disposed in a housing, a plurality of cam ring members surrounding the rotor in axially disposed side-by-side relationship including sets of vanes respectively associated with a cam ring and displaceable in radially extending slots in the rotor and subdividing a working chamber disposed between the rotor and cam rings. Inlet and outlet orifices lead into working cells and cheek plates laterally confine the working chamber.
A vane-type motor of this type is disclosed in U.S. Pat. No. 3,455,245. This conventional vane-type motor includes two vane-type units disposed in a housing in axial side-by-side relationship which respectively include a cam ring, vanes and rotor element located between two cheek plates. The cam rings have identical stroke curves over which the vanes move and with respect to their stroke curves are in axial alignment. The two cam rings are disposed non-rotatably relative to one another and relative to the two cheek plates. In such a vane-type motor, the volumetric displacement of the motor or pump can be changed only in steps by changing the number of axially aligned units.
The periodical "Oelhydraulik Und Pneumatik" 19 (1975), No. 3, at pp. 153 et seq. describes an infinitely variable double-acting vane-type pump having only one cam ring rotatable relative to the inlet and outlet orifices for changing the volumetric displacement. An arrangement of this type produces adverse flow conditions likely to result in excessive pressure pulsations which require costly efforts for compensating the resultant disadvantageous effects.
U.S. patent application Ser. No. 805,345 now U.S. Pat. No. 4,659,294 discloses a vane-type motor including structures directed to overcoming the shortcoming heretofore experienced. That device includes at least one stroke ring that is rotatable in the circumferential direction relative to another stroke ring. A particularly simple form of this sort of vane-type motor provides for two stroke rings one of which is non-rotational. This device has the advantage that the displacement temporarily occurring due to rotation of one cam ring in a direction opposite to the normal direction of flow is substantially compensated by the stationary cam ring. Pressure pulsations and resultant torque fluctuatios and noises in this pump are relatively well controlled.
Although this type pump is an improvement, undesirable pressure fluctuations and noise problems still occur in the inlet channel and in the return line In particular, pronounced back-pressure pulsations are generated when rotation of the above cam ring creates a closed portion of the working chamber in which pressure fluid is trapped and compressed.
SUMMARY OF THE INVENTION
It is, therefore, the object of the present invention to provide for a vane-type motor which minimizes pressure fluctuations and noises.
According to the invention there is provided an infinitely variable vane-type motor in which the running noise and the pressure pulsation in the inlet channel of the motor are substantially reduced. Control channels are provided which serve to eliminate the extreme work chamber over-pressures formerly caused by the trapping and compression of pressure fluid.
According to an advantageous feature of the invention, control pockets are provided on the rotor for regulating the control channels.
The control channels preferably are formed, in part, by control bores provided in one of the side plates and, in part, by elongated holes or grooves provided in the rotatable cam ring which, upon rotation of the cam ring, can be brought into registry with the bores provided in one of the side plates and the stationary cam ring and in communication with the inlet channel.
BRIEF DESCRIPTION OF THE DRAWING
The invention will be better understood after a reading of the following Detailed Description Of The Preferred Embodiment in conjunction with the drawing in which:
FIG. 1 is a longitudinal cross-sectional view through a vane-type motor, showing details of instruction;
FIG. 2 is a cross-sectional view of the vane-type motor according to FIG. 1 taken in the plane of the rotatable cam ring showing further details of the construction and;
FIG. 3 and FIG. 4 are schematically illustrated cam curves of the pump of FIGS. 1 and 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The vane-type motor according to the invention includes a housing 1 made up of a variety of components, including a connection 2 serving to supply pressure fluid via a supply channel 17, and a connection (not shown) for discharging the pressure fluid via a discharge channel 68. Provided in the interior of the vane-type machine is a rotor 4 non-rotationally connected to a shaft for transmitting torque. The rotor is provided with radially extending slots 5 in which are disposed in radially displaceable manner respectively two vanes 6, 7. Vanes 6 can be placed into abutment with cam ring 8 while vanes 7 can be placed into abutment with cam ring 9. The abutment of vanes 6, 7 is supported by vane extending springs 12 guided by spring guide ledges 10, 11 disposed in bottom bores of slots 5.
Formed between cam rings 8, 9 and the cylindrical surface of the rotor is a working chamber subdivided by vanes 6,7 into working cells 13. The working cells 13 are axially confined by housing components in the form of side plates 14, 15.
The side plate 14 is provided with a port 60 for returning the leak oil discharged through the running gap between rotor 4 and side plates 14, 15. The side plate 15 includes a channel 17 leading from connection 2 to inlet openings 16, and a channel 68 leading from the outlet openings 18 to the connection for discharging the pressure fluid. The inlet and outlet openings 16, 18 are of generally kidney-shaped configuration formed in the surface of the side plate 15 facing the working chamber. The number of the inlet openings 16 and outlet openings 18 corresponds to the number of the cam curves 20, 21 respectively formed on the cam rings 8, 9. Moreover, channels 19 for the pressure fluid supply to the bottom bores of slots 5 are formed in the side plate 15 for supporting abutment of the vanes in predetermined phases.
Seals 62,64 on the axial faces of the cam rings 8, 9 are disposed between the side plates 14 and 15. Cam ring 8 is rigidly connected to side plate 14. Provided between cam ring 8 and side plate 15 is an intermediate ring 22 surrounding the cam ring 9. The side plate 14, cam ring 8, intermediate ring 22 and side plate 15 are rigidly interconnected to form the housing 1 of the vane-type motor.
Cam ring 9 is disposed between cam ring 8 and the side plate 15 with a running clearance and is radially supported on the intermediate ring 22 by an anti-friction bearing 23 or alternatively by a slide bearing (not shown) so that it is rotatable in the circumferential direction.
The bearing of the cam ring 9 in the intermediate ring 22 is not effected along the entire circumference but rather, for example, at five supporting points 24 circumferentially distributed. The anti-friction elements are held by a cage 25 or other means at the predetermined space.
As shown in FIG. 2, a rotating unit 30 is disposed substantially tangentially to the cam ring 9 and, a fork-shaped intermediate element 31 extends through an opening in the cage 25 and is in engagement with the cam ring 9. The legs of the intermediate element 31 are provided with elongated holes in which is slidingly guided a bolt 33 connected to a displacing piston 32. The displacing piston 32 is located in a pressure fluid chamber 34 and is displaceable by a control pressure. Because the motor according to this embodiment rotates in one direction only, the displacing piston includes only one pressure face for displacement against the reaction moment. Disposed between displacing piston 32 and housing 1 is a reset spring 35 for applying pressure to the cam ring 9 in a direction opposite the direction of rotation of rotor 4, which holds the rotor at the housing stop which, according to FIG. 2, is the right-hand stop, when the motor rotating unit is non-pressurized.
Formed between the portions 44 of the rotor 4 receiving the vanes 7 are respective control pockets 45 which communicate directly with working chambers 13, 13'. Provided in the adjacent side plate 14 are control bores 46 correspondingly extending in axially parallel direction which, as viewed in the radial direction, are disposed at the level of the control pockets 45 and which are part of control channels connecting the working chamber 13, 13' to the inlet channel 16 as rotor 4 rotates. The control channels, one of which is provided for each working chamber, are cyclically opened and closed by control pockets 45 moving into and out of registry with the control bores 46. As another part of the control channel, bores 47 are provided in the side plate 14 extending in parallel to the control bores 46, which are in communication with the control bores by way of channels 55 (only one of which are shown) and which preferably can also be formed as an annular channel. The channels 55 on the radially inward side are sealed by sealing elements 59. Corresponding ports 48 disposed on the same radius are provided in cam ring 8. Each of these ports 48 lead to an elongated hole or groove 49 formed in the cam ring 8. Groove 49, by way of a port 51 provided in cam ring 9, is in communication with an elongated hole or groove 56 formed on the other side of the cam ring 9. Groove 56, in turn, by way of a port 53, is in communication with the inlet channel 17.
Operation of the vane-type motor according to the invention, will be explained in the following with reference to FIGS. 3 and 4:
FIGS. 3 and 4 shows vane extending conditions in the course of the rotation of the rotor 4. Vanes 6 and 7 which, in the illustration are arranged in series take different positions during rotation of the rotor in the direction as shown by arrow 40. FIG. 3 shows the position of the cam curve 20 of the stationary cam ring 8 and the position of the cam curve 21 of the cam ring 9 relative to an inlet opening 16 and outlet opening 18 in the non-rotated state of the ring 9. FIG. 4 shows the position of the cam curve 21 with the cam ring 9 rotated relative to the stationary cam ring 8.
Reference is first made to the case as illustrated in FIG. 3 wherein the cam curves 20, 21 of both cam rings 8, 9 are in axial alignment. In the embodiment shown, the cam curves 20, 21 of both cam rings 8, 9 are of identical configuration. According to the illustration in FIG. 3, the cam curves 20, 21 of both cam rings 8, 9 are in the normal position. High-pressurized pressure fluid, is passed by inlet opening 16 into the working cell 13 causing a rotation of the rotor 4 in the direction identified by arrow 40. The fluid is then passed through the outlet opening 18 to the connection for discharging the relieved pressure fluid. Vanes 6, 7 synchronously change position against the force of springs 12 when passing through the various positions in the slot 5 of the rotor 4. Bores 47 and 48 are not in registry with bore 51 so that there is no connection, to the inlet channel. The motor thereby operates on maximum work volume, that is, with minimum speed and maximum torque.
Reference is now made to the case in which the cam curve 20 of the stationary cam ring 8, as shown in broken lines in FIG. 4, remains unchanged and the cam curve 21 takes the position identified by the solid line relative to the inlet and outlet opening 16, 18 respectively. Vanes 6, 7 no longer displace synchronously as the movement of vane 6 is determined by the cam curve 20, and the movement of vane 7 is determined by cam curve 21 which is displaced from curve 20. A reduction in work volume from the maximum work volume thereby occurs.
In the position according to FIG. 4, bores 48 and 51, at least in part, are in registry. Because control bore 46 is in a predetermined position relative to the cam curve 21, and because there is a corresponding dimensioning of control pockets 45, the control edge 50 of the control pockets releases the aperture of the control bore 46 when cell 13' reduces in size. Due to the rapid opening of the control bore 46, a connection to the inlet channel is established and a sudden pressure build-up in the cell 13' is precluded, thereby eliminating the pronounced pressure fluctuations which would otherwise result from a compression of fluid trapped in the contracting working cell 13'. The control will become efective especially upon a displacement of the cam ring between about 5° and a maximum displacement angle.
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A vane-type motor is disclosed including a rotor disposed in a housing having a plurality of cam rings surrounding the rotor, which cam rings are displaceable relative to one another in the circumferential direction. Vanes associated with the cam rings subdivide a work chamber provided between the rotor and the cam rings into work cells and side plates laterally confine the work chamber. An inlet channel supplies pressure fluid to the work chamber and a discharge channel provides for discharge of the pressure fluid from the work chamber. Control channels are provided to preclude pressure impacts and noises with the cam ring displaced. The control channels terminate in the work chamber and connect the work chamber to the inlet channel. The rotor forms a control element for the control channels.
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority on the provisional patent application filed Aug. 12, 1996, under Serial No. 60/023,250, of the same applicant.
FIELD OF INVENTION
The present invention relates to mammalian antiviral therapy. More particularly, it concerns the use of novel hematopoietic cells to reduce or eliminate human HIV infection.
BACKGROUND OF THE INVENTION
Recent advances in human HIV anti-retroviral therapy have included the development of powerful combinations of anti-retrovirals including nucleoside analogue and non-nucleoside analogue reverse transcriptase inhibitors used simultaneously with protease inhibitors. Nevertheless, the problem of de novo and, especially, acquired drug resistance is significant. Acquired drug resistance is now understood to be statistically more likely with greater viral load.
Prior art has identified that certain individuals are seemingly immune from HIV infection. These individuals seem to lack a normal CKR-5 co-receptor on the lymphocyte surface that must be assessed along with the CDR receptor for viral attachment.
Additional prior art has demonstrated the ability to use placental blood as a substitute for cross-matched donor stem cells in marrow transplants, and from prior art, we know that autologous human stem cells can be harvested and induced to reproduce in vitro.
Human retroviral infection with one of the variants of the HIV virus has been impossible to cure in vivo. In fact, antiviral pharmaceuticals have had limited success in retarding the infection and prolonging life. Despite a variety of pharmaceutical approaches, unfortunately, the virus has been able to develop drug resistance in each host, making it seemingly impossible to eradicate the viral infection and to control secondary infections such as CMV, retinitis, pneumocystis, pneumonia, etc.
SUMMARY OF THE INVENTION
The present invention reduces the viral replication process by using modified, novel hematopoietic cells. The multidrug antiviral and chemotherapy course can be used to eradicate the retroviral infection. Optimal time of therapy is disclosed and analyzed herein.
The pattern of emergent drug resistance in HIV infection is the result of the very high viral titers in advanced HIV infection—the acquired immunodeficiency syndrome (AIDS). Such high viral counts mean that drug resistance due to viral mutations is more likely. That is to say, the retroviral RNA mutation rate is roughly equivalent to other RNA and DNA mutation rates. But, in advanced HIV infection (AIDS), in particular, the number of replicating virions is in the billions, making it more likely statistically that drug resistance will emerge. In the hostile environment of systemic antiviral chemotherapy, the mutant virions will be “selected for.” Thus, in the individual AIDS patient, the potential for drug resistance is very high.
This invention reduces the viral “battleground” to the micro-environment of a single cell by first designing a host cell that is devoid of the infrastructure or function necessary for viral replication. This host cell has the surface receptors (CD4) in a normal or even increased density required for retroviral incorporating into the host cell. These modified lymphocytes are used to “soak up” virions into a sterile environment during a multidrug regimen. By reducing the opportunity for drug resistant mutations, the present invention can be used to eradicate or significantly suppress the infection. Secondly, the present invention purposely eliminates or reduces the normal stem cell population which ultimately produces the lymphocytes susceptible to viral replication. The present invention repopulates the bone marrow with stem cells that produce lymphocytes lacking the CKR-5 receptors.
OBJECTS OF THE PRESENT INVENTION
It is an object of this invention to provide for modification of lymphocyte target cells to produce sterile (“drone”) and/or hostile (“cruise”) host cells that reduce the viral load to below 200 copies per mm 3 when infused to a concentration of 1,000 to 1,000,000 or more cells per mm 3 and thereby mitigate the chances of emergent drug resistance during the course of antiviral treatment for retrovirus infection.
Another object of this invention is to provide a lymphocyte target cell of the type as just previously described wherein the cellular mechanisms required for viral replication are inactivated or deleted (“drone” lymphocyte).
Another object of this invention is to provide a lymphocyte target cell wherein its pretreatment with a multidrug array of antivirals substantially diminishing ability of the virus to replicate (“cruise” lymphocytes), particularly after the cellular mechanisms have been treated to inactivate or delete viral replication.
Another object of this invention is to provide for an isolation of autologous lymphocytes through the use of leukophoresis techniques for the purpose of mitigating the chances of emergent drug resistant virus during the course of antiviral treatment for retrovirus infection.
Yet another object of this invention is to provide the method for harvesting of lymphocytes for their modification through the use of the process of this invention wherein the lymphocytes may be stored for future usage.
Another object of this invention is to provide for the periodic use of leukophoresis to remove spent modified lymphocytes and to replenish the count of modified lymphocytes generated in accordance with this invention.
Yet another object of this invention is to provide the method for timing of intervention of the principal method of this invention as previously described, preferably before a significant reduction in CD4 T-cell count.
Another object of the present invention is to reduce or eliminate lymphocytes susceptible to HIV replication by repopulating the marrow with modified stem cells which do not express the CKR-t receptor on their derivative lymphocytes.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a description of leukophoresis ( 2 ) is used to isolate T-cells (lymphocytes) ( 3 ) for treatment with radiation means such as gamma radiation to inactivate the cellular infrastructure for viral replications creating “drone” lymphocytes ( 5 ) and/or with means for incubating with a multi-drug array of anti-HIV agents creating “cruise” lymphocytes before reintroducing these modified T-cells back into the patient.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The HIV-infected patient with high viral loads and/or drug resistance ( 1 ) is rescued by leukophoresis ( 2 ) removal of white blood cells, and more particularly, CD4 T-cell lymphocytes ( 3 ), allowing for creation of “cruise” lymphocytes ( 4 ) and/or of “drone” lymphocytes ( 5 ). These modified lymphocytes are returned to the patient through the leukophoresis process ( 2 ). The patient's normal population of susceptible lymphocytes is reduced by ionizing radiation ( 6 ) and/or chemotherapy ( 7 ) aimed at making the marrow aplastic. As part of the rescue therapy, stem cells lacking the CKR-5 gene or its normal expression ( 8 ) are transplanted to the marrow. These stem cells can be autologous ( 9 ) after undergoing in vitro reproduction and gene therapy or they can be homologous ( 10 ) derivatives of placental blood after undergoing in vitro gene therapy to eliminate the CKR-5 receptors.
In one preferred embodiment, “drone” lymphocytes are created by leukophoresis (FIG. 1) removal of the patient's own lymphocytes. These autologous lymphocytes are treated with gamma radiation, ultraviolet light and the like in order to render their cytoplasmic and nuclear mechanism incapable of supporting viral replication.(FIG. 1 ).
In another preferred embodiment, the unaltered or altered, “drone” lymphocytes are treated in vitro with a multidrug array of antivirals; for example, such as a protease inhibitor, reverse transcriptase inhibitor, and nonsense nucleoside. These “cruise” lymphocytes feature an intracytoplasmic environment that is further hostile to the invading virions. In the individual host cell, such a multidrug load makes it very unlikely that drug resistance will emerge (FIG. 1 ). Moreover, concentrations of the antivirals intracellularly can be achieved in vitro that would be toxic if given in vivo systemically.
In another preferred embodiment, the T-cells of the present invention are incubated in vitro with a solution of cell surface receptors (CD4) in order to increase the ability of virus to gain access to the modified lymphocytes.
In another preferred embodiment, the isolated, autologous lymphocytes are stored for infusion into the patient at a later time. In this way, the patient with depressed host cells can provide sufficient material to create “drone” and “cruise” lymphocytes.
In order to provide sufficient reduction in viral load, the modified lymphocytes (“drone” and “cruise”) may need to be given in a count from 1,000 3 to 1,000,000 or more mm 3 , depending in part upon the patient's count of infected lymphocytes. That is to say, the greater the viral load or the greater the percentage of infected lymphocytes, the larger the number of modified lymphocytes necessary to reduce the viral load.
In another preferred embodiment, the leukophoresis process can be repeated at regular intervals to remove the old “drone” and “cruise” lymphocytes from the patient.
In another preferred embodiment, the intervention of this invention is instituted before the viral load becomes sufficient to suppress the lymphocyte count (CD4 T-cells) significantly. In this way, the viral load represents a much smaller number, making it more likely statistically to avoid drug resistance during antiviral therapy.
In another preferred embodiment, the patients undergo chemotherapy designed to eradicate their stem cells. They are then “rescued” by marrow transplants from matched donors, wherein the donor cells are pre-treated with a multidrug array of antivirals.
In another preferred embodiment, patients are treated with chemotherapy after their marrow cells have been harvested. Their marrow cells are pre-treated with a multidrug array of antivirals before autotransplantation.
In another preferred embodiment, the normal population of susceptible CD4 T-cell lymphocytes can be reduced or eliminated. Ionizing radiation or alkylating chemotherapy can be used to make the marrow aplastic. The marrow is then repopulated with autologous stem cells or homologous stem cells from placental blood. In either instance, gene therapy pre-treatment can be done to block expression of the CKR-5 receptor in the derivative CD4 T-cells. In the case of placental blood, preference is given to donor material which naturally lacks expression of the CKR-5 receptor.
Variations or modifications in the method of treating viral contaminated cells may occur to those skilled in the art upon reviewing the summary of the invention, in addition to its preferred embodiments. Such variations, if within the spirit of this invention, are intended to be encompassed within the scope of the disclosure provided herein.
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The risk of drug resistance in HIV infection is reduced by profoundly suppressing the viral load using novel hematopoietic cells. Modified CD4 lymphocyte host cells are used to “capture” virions in a sterile micro-environment. The host's CD4 T-cell lymphocytes are replaced with lumphocytes derived from autologous or homologous stem cells which do not express the CKR-5 receptor, further inhibiting viral load.
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BACKGROUND OF THE INVENTION
1. Field of the Invention:
The present invention relates to a universal fertilizer (or other material) spreader which may be attached to any type of lawnmower, be it self-propelled or not and also allows for removal/reinstallation on same or other types or sizes of lawnmowers as deemed useful. The system of the invention also includes two separate devices, a handle lock, which locks the handle in position and prevents accidental spillage of the fertilizer during operation, and a mounting tool provided to assist the user in mounting and attaching the hopper unto the lawnmower.
2. Prior Art:
In the past, prior attempts at fertilizer/chemical/seed spreaders have primarily been confided to two entirely separate types of devices. One type, in which mowing and fertilizing are achieved as two separate tasks, requiring a separate spreader and mower, is essentially a repetitive, time consuming process in which the operations must be performed as two separate steps and not simultaneously. The other type (such as P. G. Redman, U.S. Pat. No. 3,100,371), an add on type, has primarily dealt with integration of the spreader with the lawnmower, in that the fertilizer is fed through the blade housing and distributed primarily by the action of the lawnmower blade while turning. This type affords two primary disadvantages:
(1) the spreader becomes permanently attached to and is part of the lawnmower; and
(2) allows for contact between the fertilizer/chemicals and the mower and/or rotary blade assembly, thereby allowing corrosive/chemical reactions on the lawnmower itself to take place. This leads to possible early failure of the lawnmower and/or the blade assembly. It is also highly doubtful that the action of the blades in this type of device is sufficient in obtaining adequate spreading of the fertilizer.
Other attempts (A. P. Vicendese et al. U.S. Pat. No. 3,942,308) have been to combine the lawnmower and spreader into one entity, but these suffer the disadvantages in that the spreader assembly is integrated with the lawnmower itself and cannot be removed and attached to another lawnmower.
One attempt at a spreader (A. G. Troka, et al., U.S. Pat. No. 3,102,375) which is detachable has three shortcomings:
(1) it is not readily adaptable to lawnmowers of different widths;
(2) has a fixed spread width; and
(3) is located rearwards of the rear wheel, thereby moving the center of gravity farther back, so that upon filling of the hopper, possible tilting of the lawnmower will take place with corresponding spillage of the contents of the hopper being possible.
Other attempts at removable spreaders have relied on the vibration and swinging movements of the handle to provide for spreading of the contents. This type of system has obvious flaws in that the spread of the fertilizer is very erratic and uneven, and little control over the fertilizing process is possible.
In R. N. Kelly's spreader (U.S. Pat. No. 2,639,571) control of spreading is achieved by the blades of a rotary blade lawnmower periodically engaging an arm, which in turn swings a door open while moving agitator pins back and forth, to achieve spreading of the contents. The disadvantages of this type of spreader are:
(1) operable only with rotary blade lawnmowers;
(2) has a fixed width of spread of fertilizer;
(3) has a complicated mechanical device which would be prone to failure; and
(4) moves the center of gravity farther backwards which makes possible spilling of the contents.
The shortcomings of the prior art show the need for a spreader which is universally adaptable for use for example with push or powered mowers of the non-rider type. The system should also provide for adjustment of fertilizer spread width and should be adaptable to all width mowing machines. The system should also allow for control of the rate at which fertilizer is spread and allow for no contact between the fertilizer and the lawnmower to prevent corrosive/chemical attack of the lawnmower. Also the system should not substantially alter the center of balance of the lawnmower in a negative fashion and both provide for moving the spreader to other lawnmowers and allow for fertilizing to take place without the lawnmower being on. It is an aim of the present invention to fill all the shortcomings of the prior art and to meet the conditions as set forth in the above.
Prior U.S. patents which may be of interest are listed below:
______________________________________Patentee (s) U.S. Pat. No. Issue Date______________________________________Alexander Konrad 3,097,467 July 16, 1963C. W. Anderson 3,359,710 Dec. 26, 1967L. Coffman 3,477,212 Nov. 11, 1969A. P. Vicendese, et al 3,942,308 Mar. 9, 1976P. C. Redman 3,100,371 1963H. McCain 3,332,221R. N. Kelly 2,639,571 May 26, 1953C. F. McBride 2,974,963 Mar. 14, 1961A. G. Troka, et al 3,102,375 Sep. 3, 1963V. H. Peoples Re 24,189 July 31, 1956______________________________________
The Peoples patent is directed to an independent spreader, while the other patents show variations of some form of spreader or dispenser associated with a lawnmower.
BRIEF DESCRIPTION OF THE DRAWINGS
For a further understanding of the nature and objects of the present invention reference should be made to the following detailed description, taken in conjunction with the accompanying drawings, in which like parts are given like reference numerals and wherein:
FIG. 1 is an overall, rear, perspective view of the preferred embodiment of the spreader attachment of the present invention mounted on an exemplary lawnmower.
FIG. 2 is a side view, partially cut-away, in which a sectional view of the agitator, its driving mechanism, the "fingers", and splash plate of the spreader as attached to the lawnmower of FIG. 1 is seen.
FIG. 3 is a cross-sectional, close-up, partial view of the adjustable width, agitator mechanism and its associated drive wheels as mounted on the mower.
FIG. 4 is a partial, close-up view of the lower portions of the transfer funnel "fingers" and splash plate with its associated positioning markers.
FIG. 4A is a side, partial, close-up view of one of the transfer funnel "finger", the splash plate, and a "Velcro" fastening system for joining the splash plate to the "fingers" of FIG. 4.
FIG. 5A is a side, partial, close-up view of one of the transfer funnel "fingers", the splash plate, and an alternate snap ring fastening system for joining the splash plate to the fingers; while
FIG. 5B is an end, close-up of the snap ring element for each "finger" for the fastening system of FIG. 5A.
FIG. 6 is a perspective view, partially exploded, of an exemplary handle locking accessory used in the system of the present invention when the lawnmower has a pivoting handle.
FIG. 7 and FIG. 7A are partial, cross-sectional views of the handle clamp, taken with the handles at 90 degrees to each other, which attach the spreader of FIG. 1 to the mower.
FIG. 8 is a perspective, top view of the wheel mount tool used as a mounting accessory in the system of the present invention.
SUMMARY DISCUSSION OF INVENTION
The present invention, as embodied, provides a spreader in which adjustment of the fertilizer spread width, as well as adaptable means for mounting on all widths of mowing machines is achieved. The invention allows for control of the rate at which fertilizer is spread and allows for no contact to take place between the fertilizer and the lawnmower in order to prevent any corrosive or chemical attack on the lawnmower and blade assembly, Also, the spreader of the preferred embodiment of the invention does not substantially alter the center of balance of the lawnmower in a negative manner and provides for moving of the spreader to other lawnmowers as well as allowing for fertilization to take place without the lawnmower being on. In using the term "fertilizer" (and its variants herein, such term includes any dispensible lawn care product, such as for example seeds, pesticides, and other chemicals, not only the usual lawn fertilizers.
It is a definite advantage to combine mowing operations with fertilization, resulting in economics of both time and, when applicable, money. It is also desirable that the device which performs the spreading be universal in nature, adaptable to all lawnmower widths, controllable as to fertilization rate while maintaining uniformity of spread, and maintain separation of the fertilizer from the lawnmower, including also the blades, in order that undesirable corrosive/chemical reaction of the lawnmower and its associated parts will not take place. It is further a desired aim that the invention, hereafter described, have as a primary goal the integration of such features into its design.
These and other advantages of the invention will become more clear from the detailed description of the preferred embodiments to follow.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1 a preferred embodiment of the spreader 20 of the present invention can be seen as it is mounted on an exemplary lawnmower 21. In this view, the spreader 20 is seen mounted via handle clamps 70 (seen in close-up in FIGS. 7 and 7A) which are attached to the spreader 20 by means of wingnuts 11, for example, and which extend through holes on support arm connector bar 22. A series of holes on the support bar 22 provide for adjustable widths in order to accomodate mounting on lawnmowers of different width handlebars and different width wheel bases 12. The angle iron connector bar 22 is securely affixed to the hopper 13 by riveting or welding or such other means as desired. A control cable 14 is used to control the opening and closing of the sliding door or shutter 23 (see FIG. 2) in order that fertilization may be obtained as desired.
The drive wheel 25 (see FIG. 2) for the hopper 13 is driven by the rotating mower wheel 14 as the mower is pushed, or mechanically driven, across the ground, and the drive wheel 25 in turn drives a flow control system or agitator system 31 for the fertilizer (as explained more fully hereinafter). The rate at which the lawnmower is driven or pushed in combination with the sliding door 23, thereby results in controlling the rate at which the fertilizer is delivered.
As the drive wheel 25 turns, fertilizer in the hopper 13 is delivered down to the transfer funnel, distribution "fingers" 41, at a controlled rate, and is in turn delivered further down to the splash plate 42, which assists in maintaining an even spread of fertilizer across the width, as so desired, of ground as traversed by the mower.
Also seen in FIG. 1 is the handle lock assembly 60 (seen in close-up in FIG. 6), which prevents any forward, upward movement of the handle 12 in relationship to the mower body 15. By this means the normal pivoting of the handle on pins 16 is prevented and accidentalspillage of the contents of hopper 13 is prevented.
In FIG. 2 a side view of the spreader 20 as attached to the lawnmower 21 is seen. In this view, a sectional view of the drive wheel 25 and agitator assembly 31 is seen. Also shown is an angular cut section 24 on the hopper 13 which prevents the hopper 13 from blocking the normal line of sight and allows for easy viewing of the mowing operation by the operator, in particular one who is relatively short.
As lawnmower 21 is pushed or driven mechanically across the ground, rear wheels 14 rotate, and be being in frictional contact with the drive wheels 25, drive wheels 25 are caused to turn also. As the drive wheels 25 turn, rotational motion is transfered by means of an axial shaft 32 (note FIG. 3) to the adjustable width, agitator axle assembly 31. As the agitator axle assembly 31 turns, fertilizer is distributed by means of the hopper agitator 36 to the distribution "fingers" or tubes 41 at a controlled rate. The rate is further controlled by use of control cable 14 and sliding door 23. When the lever 26 is to the rear, a maximum flow rate will be established as sliding door 23 completely uncovers opening 27; and, when the lever 26 is fully forward, no dispensing of the contents of the hopper will take place. At positions of lever 26 between these two points, the size of the opening 27 is effectively controlled. This, in combination with the angular velocity at which the agitator is turning, controls the fertilizer flow rate emitting from opening 27 and entering the "fingers" 41.
From this point, the fertilizer travels down through the "fingers" 41 and is spread out by the splash plate 42 and evenly distributed to the ground.
In FIG. 3 a detailed view of the agitator assembly 31, including agitator body 36, axial shaft 32, and drive wheel 25, is seen as they are connected through the wall of the hopper 13. Axial shaft 32 is able to laterally vary its exposed length 33 back and forth by being moveable in and out with respect to the agitator body 36 but then lockable in the lateral position desired by means of a set screw 34 or other type of temporary fastener. This allows for the selective mating of the drive wheels 25 with the rear wheels 14 of the lawnmower regardless of their lateral spacing and allows for the adaptation of the spreader to lawnmowers of different widths.
The set screw 34 also serves to transmit the rotational motion of wheel 25 to the agitator body 36. As drive wheel 25 is caused to turn by rear wheel 14, axial shaft 32 which is affixed to drive wheel 25 at its end is caused to rotate also. This rotational motion is transferred along the shaft 32 and is transmitted to the agitator body 36 by means of set screw 34 which prevents axial shaft 32 from turning in the axle assembly 31, resulting in the rotation of drive wheel 25, shaft 32, and agitator/axle assembly 31 as one, integral unit.
Bushing 35, as is known to those skilled in the art, serves both to provide bearings, which provide a fixed turning point for shaft 32, while preventing the contents of the hopper 13 from entering the bearing area, thereby preventing both loss of hopper contents and damage to the bearing area and the surface of the shaft 32.
As agitator/axle assembly 31 turns, agitator vanes or body 36 stir the contents of the hopper 13 and assist in distributing the contents of the hopper 13 at a controlled rate through opening 27 (see FIG. 2).
In FIG. 4 a close-up view of the lower ends of "fingers" 41 and their attachment to the splash plate 42 can be seen. In a first embodiment (note FIG. 4A) the "fingers" 41 are attached to the splash plate 42 by means of fastenings such as "Velcro" 52, as illustrated, wherein the hook material of the "Velcro" material is fixedly attached to one of the parts (for example the "finger" tubes 41), while the loop material is fixedly attached to the other part (for example the splash plate 42). As is well known, such a "Velcro" type fastening system allows for temporary fastening of the parts which can be easily made, undone and altered, when and as desired. Alternatively, some other temporary fastening system, such as for example appropriate configured clamps or snap connections such as the preferred circular snap ring 51, as seen in FIGS. 5A and 5B, could be used with the tubular "fingers" 41. In this alternate embodiment, the snap ring 51 is carried by the "finger" 41 and has a bulbous projection 52 on its underside which mates with an indentation, hole or enlarged area 53 in the splash plate 42 where the two are snaped together and held compressing, frictional engagement.
The splash plate 42, as can be seen in FIG. 4, has a series of positioning marks 43 on the surface of the plate which guide the user in positioning the ends of the "fingers" 41 and their lateral, end spacing to allow for varying the width of the spread of fertilizer to coincide with that of the lawnmower, or as so desired. Although not illustrated, the "Velcro" material and the indentations (or other fastening means used) are included at least at various alternate spots along the lateral width of splash plate 42 to allow for the lateral positioning of the ends of the "fingers" 41 as desired. Splash plate 42 also serves to assist in evenly distributing the fertilizer as it emerges from the "fingers" 41 so that an even spread may be obtained. Additionally the plate 42 serves to anchor and hold the "fingers" 41 in position. For further support of the splash plate 41 a beaded, adjustable length support chain 90 can be included as illustrated (note FIGS. 1 and 2) for suspending support of the splash plate 42 and its attached "fingers" 42 from the cross-bar 22.
The use of "fingers" or separate, laterally spaced channels for distributing the fertilizer from the hopper 13 down past the mower handles 12 is very important because they are laterally flexible to a sufficient extent and can have their terminal end spacings easily varied. This allows for easy adaptation of the spreader to lawnmowers having different handle locations and different lateral positioning or widths of the handles. Thus, the distribution "fingers" 41 can straddle the handles 12 (or other fixed items on the lawnmower) where necessary (as illustrated) or be contained totally between the mower handle sections where the mower handle has a relatively wide stance. Thus the "fingers" 41 should have a certain degree of lateral flex or flexibility or at least their mounting on the funnel at the hopper bottom should have some lateral give or movement.
In FIG. 6 the handle lock assembly 60 is seen in detail. Mower chassis hook 61, which forms a reverse clip of "U" shaped configuration, is attached to and engages the sides of the bottom, rear, downturned lip of the housing of the lawnmower 21, and handle yoke 62 is placed around the handle 12 of the lawnmower. Cable lock 63 (two parts) and thumb screw 64 are used to lock the handle 12 in position so that the contents of the hopper 13 will not be accidently spilled by movement of the mower handle. The handle lock 60 is made up of an elongated flexible line 65 (for example a steel cable) which extends from the hook clip 61 and looped back around to form the yoke 62. The effective length of the cable 65 can be varied as desired by altering the amount of the cable in the yoke when the handle lock 60 is not in its operative locked disposition as shown in FIGS. 1 and 2, but is otherwise inextendible in length when so in use.
In FIGS. 7 and 7A a simple type of handle clamp 70 is seen in detail. In this type of clamp, use is made of clamps 71 and 72 that are similar to hose clamps in that they adjust their sizes by means of screws 73 and 74, respectively, to enclose different handle diameters. Screws 73 and 74 are also used to tighten the clamps 71 and 72 about the mower handle 12 and hopper support arm 17. Pivotal rivet 75 allows for proper angular placement of the clamps 71 and 72 as the spreader 20 is mounted on the lawnmower 21. The clamp assembly 70 allows for selective positioning of the spreader 20 on the mower 21 for both control of the center of balance, thereby assisting in preventing tipping of the entire mechanism 20 and 21 due to transfer of the center of gravity (that is, maintains the center of balance between the front and rear wheels of the mower) and positioning of the spreader 20 so that the drive wheels 25 are in direct frictional contact with the rear wheels 14 of the mower 21.
In FIG. 8 a view of the accessory mounting tool 80, two of which allow for easy, one man installation of the spreader 20 on the lawnmower 21, is seen. Each tool 80 includes a semi-circular, rigid, fixed upper section 83 and a flexible, semi-circular lower section 82 with an attached brace 81, with the two sections 82, 83 attached together back-to-back. Prior to installation of spreader 20, the two wheel mount tools 80 are placed in position on the rear lawnmower wheels 14, and braces 81 are adjusted against appropriately selected stops 84 to assist the load support of the hopper weight, which in the embodiment illustrated has a center of gravity a little bit to the rear of the axis of the rear lawnmower wheels 14. The flexible, bottom wheel mount section 82 will make full surface, facing contact with the tire of the lawnmower wheel 14, maintaining the positioning of the wheel mount tool 80. Spreader assembly 20, with its drive wheels 25 locked by means of lateral slide bolts 95 slidably attached to the front of the hopper 31 engaging the wheels 25, may now be easily placed into position with each drive wheel 25 placed in its respective upper wheel mount section 83 which engages it in face-to-face contact. As such, each wheel mount tool 80 serves to maintain its drive wheel 25 in proper alignment with its lawnmower wheel 14, and the two tools 80 together temporarily supports the hopper 13 through the drive wheels 25 until the spreader assembly 20 has been finally mounted and finally connected in position on the lawnmower. After final connection of the spreader 20 has taken place, removal of the two wheel mount tools 80 and disengagement of the bolts 95 will allow for the drive wheels 25 to directly contact and rotate with their respective lawnmower wheels 14 in a frictional manner so that turning of the wheels 14 will cause the drive wheels 25 to rotate also. In FIG. 1, one of the wheel mount tools 80 can be seen in position between the two wheels 14 and 25 prior to removal and the subsequent operation of the lawnmower and the spreader 20.
As can best be seen in FIG. 2, the hopper 13 has an inverted, generally triangular configuration in side view and is located directly above the rear wheels 14 of the lawnmower 21, above and in front of the handle 12, with the "fingers" 41 rearwardly extending from the bottom area of the hopper 13 back down past the handle 12 generally adjacent to ground level past the rear end of the lawnmower body or housing, resulting in the fertilizer being spread on the ground completely behind the lawnmower. Additionally, the only structural support and structural connection between the hopper 13 and the lawnmower 21 is via the two drive wheels 25 resting on the rear wheels 14 and the connecting arms 17 extending back from the rear of the hopper 13 to the handle 12 of course the flexible control cable 14 does not constitute a structural support or structural connection member in that it carries no significant load or weight. This placement, which puts the great bulk of the relatively heavy load of the hopper, its contents, and associated distribution system on the drive wheels 25, results in a good, reliable, frictional driving engagement with the rear wheels 14 and an over-all well balanced combined lawnmower and spreader attachment, with universal attachments to most size lawnmowers and with all fertilizer distribution occuring away and separate from and behind the lawnmower.
Because many varying and different embodiments may be made within the scope of the inventive concept herein taught, and because many modifications may be made in the embodiment herein detailed in accordance with the descriptive requirements of the law, it is to be understood that the details herein are to be interpreted as illustrative and not in a limiting sense.
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A universal spreader comprising a hopper; a cable by which the speading of fertilizer/chemical/seed/pesticide/etc., in the hopper may be inititated or terminated; a rotatable, driven agitator which distributes and controls the amount of the fertilizer; an adjustable width drive for the agitator; a series of moveable fertilizer delivery tubes or "fingers" for delivering the fertiziler from the hopper to the ground which allows spreader to be fit on lawnmowers of most sizes with handles of different and varied configurations; and a guide securing device which also assists in spreading the fertilizer from the "fingers" while also serving to provide a base for anchoring and adjusting the width of the "fingers" to coincide with the swath of the lawn cut by the blades of the mower. Two additional, accessory devices include handle lock to prevent forward and rearward motion of the lawnmower handle and a temporary, wheel contacting, mounting tool to assist the user in mounting and attaching the hopper unto the lawnmower in a one man operation.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of the earlier filing date of provisional application 61/353,681, filed Jun. 11, 2010.
FIELD
The present disclosure relates to an insulated foundation and subflooring structure. More particularly, the disclosure relates to an insulation structure having improved insulating and venting structure.
BACKGROUND
Many homes are constructed having a crawlspace that is created under the floor of the house as a result of the house being placed on a foundation. Crawlspaces are generally porous and do not provide adequate sealing against moisture and insulating to prevent heat loss and gain. When moisture enters the crawlspace, water enters the wood forming the floor joists and the various other flooring structures above the crawlspace. The moisture can result in a large number of mold spores and create a desirable environment for insects to live. An additional problem relates to preventing insects such as termites from nesting in the crawlspace. Another problem relates to allowing the ventilation of gases, such as radon, while still providing protection against moisture and heat loss and gain. While various attempts have been made to provide suitable sealing and insulating systems, improvement is desired.
Accordingly, the present disclosure relates to an encapsulation system that provides for sealing against moisture, insulating to prevent heat loss and gain, the repelling of insects, and allowing the venting of gases in crawlspaces.
SUMMARY
In a first aspect, the present disclosure provides an insulated foundation and subflooring structure that includes a foundation wall, a sill plate fastened to the top of the foundation wall, a header joist fastened to the top of the sill plate, a first and a second floor joist spaced apart from each other where the floor joists are fastened to the top of the sill plate, and an insulating joist plug compressibly fit between the floor joists and fastened to the top of the sill plate.
In one embodiment, the insulated foundation and subflooring structure includes an insulating joist plug made from a foamed polymer selected from the group consisting of polystyrene, polyurethane, polyethylene, polypropylene, polyisocyanurate, and mixtures thereof. In certain embodiments of the insulated foundation, the insulating joist plug is made of foamed polystyrene.
In certain embodiments of the insulated foundation and subflooring structure, the insulating joist plug is made of a foam polymer having an insecticide dispersed within the foamed polymer. Further, in some embodiments according to the present disclosure, the insulating joist plug is made of a foamed polymer having an insecticide, containing a boron-containing compound, dispersed within the foamed polymer. In one embodiment of the insulated foundation, the boron-containing compound is disodium octaborate tetrahydrate.
In certain embodiments of the foundation and subflooring structure, the insulating joist plug has an R value from about 10 to about 36. Further, in some instances, the insulating joist plug contains one or more slits. The insulated foundation and subflooring structure may also consist of the two floor joists where the two floor joists are substantially parallel to one another and perpendicular to the header joist.
In a second aspect, the present disclosure provides a crawlspace encapsulation system that includes a foundation wall, a sill plate fastened to the top of the foundation wall, a header joist fastened to the top of the sill plate, a first and second floor joist space apart from each other where the floor joists are fastened to the top of the sill plate, an insulating joist plug shaped to compressibly fit between the floor joists, one or more insulating panels fastened to a portion of the foundation wall, and a polymeric membrane that overlaps a portion of the insulating panels and covers the ground adjacent the foundation wall. The polymeric membrane is preferably waterproof and/or resistant to moisture and/or other vapors.
In one embodiment, the encapsulation system includes the insulating panels having a portion that is comprised of one or more venting channels that are connected to the space beneath the polymeric membrane.
In certain embodiments of the encapsulation system, the insulating joist plug and insulating panels are made of a foamed polymer selected from the group consisting of polystyrene, polyurethane, polyethylene, polypropylene, polyisocyanurate, and mixtures thereof. In a particular embodiment, the insulating joist plug and the insulating panels are made from foamed polystyrene.
In certain embodiments, the encapsulation system includes an insulating joist plug and insulating panels made of a foam polymer having an insecticide dispersed within the foamed polymer. In one embodiment, the insulating joist plug and insulating panels are made of a foamed polymer having an insecticide, containing a boron-containing compound, dispersed within the foamed polymer. In a particular embodiment, the boron-containing compound includes disodium octaborate tetrahydrate.
In certain embodiments, the floor joists are substantially parallel to one another and are substantially perpendicular to the header joist.
The encapsulation system preferably has an insulating joist plug with an R value from about 10 to about 36 and insulating panels with an R value from about 5 to about 30. The encapsulation system also preferably is configured such that at least a portion of the insulating panels are separated from one another on one side of the insulating panels. Preferably, the insulating panels have a width of from about 1 to about 24 inches and are fastened to one another by adhesive tape or a polymeric film.
In certain embodiments of the encapsulation system a portion of the insulating panels may be removed to provide access to the foundation wall and sill plate. In one particular embodiment, a portion of the insulating panels includes a hinge that allows the portion to be opened to provide access to the foundation wall and sill plate. In one embodiment, the insulating joist plug may be removed from the encapsulation system to provide access to the foundation wall and the sill plate.
BRIEF DESCRIPTION OF THE DRAWINGS
Further advantages of the disclosure are apparent by reference to the detailed description when considered in conjunction with the figures, which are not to scale so as to more clearly show the details, wherein like reference numbers indicate like elements throughout the several views, and wherein:
FIG. 1 is a perspective view of an insulating joist plug according to one embodiment of the disclosure.
FIG. 2 is a top plan view of the insulating joist plug of FIG. 1 .
FIG. 3 is a side view of an encapsulation system according to one embodiment of the disclosure.
FIG. 4 is a top plan view of the insulating panels having venting channels adjacent the foundation wall according to one embodiment of the disclosure.
FIG. 5 is a top plan view of an alternate embodiment of an insulating panel having individual panels of varying thickness to create venting channels according to one embodiment of the disclosure.
FIG. 6 is a side view of the insulating panel of FIG. 4 showing the hinged portion of the panel providing access to the foundation wall and sill plate according to one embodiment of the disclosure.
DETAILED DESCRIPTION
With reference to the drawings, the disclosure relates to a crawlspace encapsulation system 10 having one or more insulating joist plugs 12 installed above one or more insulating panels 14 and a polymeric ground membrane 16 installed on the floor of the crawlspace.
In a typical foundation and subflooring system, as shown in FIG. 3 for example, the floor 114 is supported by one or more floor joists 100 rest on top of the sill plate 104 and are fastened to a header joist 102 also resting on the sill plate 104 . The sill plate 104 is attached to the top of the foundation wall 106 . The foundation wall 106 supports the sill plate 104 and flooring joists 100 and is attached to the ground 110 . The foundation wall 106 may include a ventilation duct 112 between the interior and exterior of the crawlspace. Any or all of the floor joists 100 , header joist 102 , sill plate 104 , and foundation wall 106 may be chemically treated to provide resistance to termite infestation. For instance, a composition comprising a boron-containing compound (such as disodium octaborate tetrahydrate) and a glycol and/or glycerine may be applied to the outer surfaces of these members.
With reference to FIG. 2 , the insulating joist plug 12 is desirably configured to compressibly fit between the floor joists 100 a and 100 b . The insulating joist plug 12 is constructed of a foamed polymer such as polystyrene, polyurethane, polyethylene, polypropylene, polyisocyanurate, and like materials. More preferably, the foamed polymer is foamed polystyrene. It is also understood that the insulating joist plug 12 may be constructed of a foamed polymer which includes an insecticide dispersed in the interstitial spaces between the cells or beads of the foamed polymer. For instance, an organic insecticide such as deltamethrin or imidicloprid may be included within the foamed polymer. More preferably, the insecticide may be a boron-containing compound, such as disodium octaborate tetrahydrate. Other suitable boron-containing insecticide compounds include boric acid, sodium borates (such as borax and sodium pentaborate) calcium borates, sodium calcium borates, and mixtures thereof. Certain insects, such as termites, may forage on and damage untreated foamed polymers, or eat wood. The inclusion of such insecticides within the insulating joist plug provides the joist plug with a resistance to termite foraging and damage.
The insulating joist plug preferably includes a plurality of slits 14 oriented parallel to the floor joists. The slits 14 allow for compression of the insulating joist plug 12 to ensure a tight fit of the insulating joist plug 12 between the floor joists 100 a and 100 b . Because of the compression abilities of the insulating joist plug 12 , the width W ( FIG. 1 ) of the insulating joist plug 12 may be such that it is equal to or slightly greater than the distance between floor joists D, ensuring a secure fitting of the insulating joist plug 12 . In typical modern framing, floor joists are generally placed about 16 inches apart from center to center. Allowing for the thicknesses of the floor joists, this means that the width W of the insulating joist plug will generally be from about 14″ to about 15″ inches.
The insulating joist plug 12 is preferably configured to rest above of the sill plate 104 and to sit adjacent to the header joist 102 . The insulating joist plug generally has a thickness from about 2½″ to about 10″ inches and provides an insulating R value of from about 10 to about 36.
The encapsulation system 10 also includes a plurality of insulating panels 14 . The insulating panels 14 may be formed from the same polymeric materials as the insulating joist plugs 12 , although the thickness and other dimensions of the panels 14 may differ from those of the joist plugs 12 . For instance the insulating panels 14 may be constructed of a foam polymer such as polystyrene, polyurethane, polyethylene, polyproplyene, polyisocyanurate, and like materials. More preferably, the foamed polymer is foamed polystyrene. The insulating panels 14 may also include an insecticide as in the insulating joist plug 12 . Preferred insecticides include boron-based compounds such as disodium octaborate tetrahydrate. The insulating panels generally provide an insulating R value of from about 5 to about 30.
In one embodiment, shown in FIG. 4 , the insulating panels 14 may be configured such that alternating rectangular insulated panels 400 and one or more vented insulating panels 402 are placed adjacent to each other. The vented insulating panels 402 preferably include a vent channel 404 that is oriented such that the open side of the vent channel is directly adjacent to the foundation wall 106 . The vent 404 is also preferably oriented such that it traverses the vertical length of the insulating panel 402 from the bottom of the insulating panel 402 to the top of the insulating panel 402 near the floor joist 100 and such that the vent 404 comes in contact with the ventilation duct 112 of the foundation wall 106 . The insulating panels 14 may be configured for installation individually or such that the insulating panels 14 are attached to one another by an adhesive tape or polymeric film attached on one side of the insulating panels 14 . Attachment of the insulating panels 14 to one another by an adhesive tape or polymeric film allows the insulating panels 14 to fold so that they may be placed into the crawlspace for installation.
In an alternative embodiment, shown in FIG. 5 , the insulating panels 14 may also be configured such that an alternating panel 502 is of a different thickness than the adjacent insulating panel 504 . The insulating panels with a lesser thickness 504 than the adjacent panels 502 create a vent channel 506 directly adjacent to the foundation wall 106 .
With reference to FIG. 6 , the insulating panels 14 may include a removable panel 602 located at the top of the insulating panel 14 . The removable panel 602 is preferably configured to allow access to the foundation wall 106 and the sill plate 104 . The removable panel 602 preferably rests on top of the lower portion of the insulating panel 604 and may be configured to be completely removed during inspection and repair of the foundation wall 106 . The removable panel 602 may then be reinstalled upon completion of inspection and repair. It is also understood that the removable panel 602 may be attached to the lower portion of the insulating panel 604 through use of an adhesive tape, polymeric film, 606 or similar means, allowing the removable panel 602 to hinge with respect to the lower portion of the insulating panel 604 .
In a particularly preferred embodiment, the insulating panel 14 may be provided as a panel having a width of approximately eight feet and a height of approximately four feet. Both surfaces of the panel 14 are preferably laminated with a polymer film, such as a polyethylene film. Before being laminated, however, the panel 14 is preferably scored across its width at approximately one foot intervals. The panel 14 may then be easily cut along one of the score lines to remove a portion of the panel so as to provide an appropriate size for a particular crawlspace installation. Alternatively, the panel may be cut along one of the score lines, while leaving the laminated film intact, thereby providing a hinge. In this way a portion of the panel 14 may also be temporarily folded back along one of the score lines to facilitate inspection of the foundation hidden behind the panel.
With reference to FIG. 3 , the polymeric membrane 108 may preferably be installed on the ground of the crawlspace adjacent the foundation wall 106 . The polymeric membrane 108 may be fastened to the insulating panels 14 on the second side facing the crawlspace such that the polymeric membrane overlaps at least a portion of the insulating panels 14 forming a substantially airtight seal. The overlap and seal of the polymeric membrane 108 over the insulating panels 14 ensures that no moisture or other gas will be allowed to pass from the ground to the crawlspace
The polymeric membrane is preferably composed of a polymer such as polyethylene or polypropylene, and generally has a thickness from about 1 to about 5 mils. The polymeric membrane acts as a barrier to undesired vapors, such as water vapor and radon. In some instances, the polymeric membrane may also be waterproof.
The crawlspace encapsulation system creates a waterproof barrier between the crawlspace and the ground. When gases (such as radon gas) and moisture rise from the ground, the gases and moisture may occupy the space between the polymeric membrane 108 and the ground 110 . The polymeric membrane 108 prevents the moisture and gases from entering the crawlspace and allows the gases and moisture to travel to the insulating panels 14 and enter the vent channel 404 . The moisture and gases then travel through the vent channel to a ventilation duct 112 in the foundation wall 106 where it passes outside.
According to the present disclosure, the insulating joist plug preferably has with an R value from about 10 to about 36. The insulating panels preferably have an R value from about 5 to about 30, and more preferably from about 10 to about 15.
The foregoing description of preferred embodiments for this disclosure has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure to the precise form disclosed. Obvious modifications or variations are possible in light of the above teachings. The embodiments are chosen and described in an effort to provide the best illustrations of the principles of the disclosure and its practical application, and to thereby enable one of ordinary skill in the art to utilize the disclosure in various embodiments and with various modifications as are suited to the particular use contemplated.
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A crawlspace encapsulation system that enables sealing and insulating of the crawlspace while allowing for the venting of gases trapped between the ground and the sealing and insulating system. The crawlspace encapsulation system includes an insulation joist plug, one or more insulation panels, and a polymeric membrane.
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PRIORITY INFORMATION
This application claims priority from provisional application Ser. No. 60/222,751 filed Aug. 3, 2000.
BACKGROUND OF THE INVENTION
The invention relates to the field of microfabricated devices, and in particular to microfabricated devices released to move by removal of a sacrificial layer.
Microelectromechanical systems (MEMS) have a broad range of applications such as, accelerometers, gyroscopes, visual displays and micro-optical systems for fiber-optic communications. The techniques used to form the micromechanical structures, such as surface micromachining, borrow technologies like thin film deposition and photolithography from the microelectronics fabrication industry.
In surface micromachining, thin films of material are typically deposited on a surface (typically known as the handle layer) using a variety of methods to form a device layer of material on a sacrificial layer of material. The micromechanical structure is then formed by patterning and etching the device layer. After the micromechanical structure is formed, a release etch is performed to remove the sacrificial material so that the micromechanical structure is released, allowing it to move and perform mechanical functions.
One actuation scheme used to move the micromechanical structure or otherwise cause it to perform its mechanical function is electrostatic actuation. Electrostatic actuation is commonly used because it does not require complicated fabrication techniques or abnormal materials, such as piezoelectric materials. Electrostatic actuation moves the micromechanical structure by electrostatic attraction between two structures with different voltages applied thereto. When the voltages are applied, the structures move to increase their capacitance by increasing the overlap area of overlapping features, or by closing the gap between the overlapping features.
Because surface micromachining lends itself naturally to creating overlapping surfaces coupled, at least in part, with the common use of electrostatic actuation has resulted in the development of a micromechanical structure used in a number of diverse applications, such as micromirrors, accelerometers, gyroscopes, etc. This structure comprises a plate formed in the device layer that is coupled via flexure assemblies to a frame formed in the device layer. The plate is released to suspend above the handle layer by the removal of the sacrificial layer underlying the plate.
The distance between the plate and the handle layer, however, limits the actuation range of the plate in this structure. This distance directly corresponds to the thickness of the sacrificial layer. An oxide, such as silicon dioxide is typically used as the sacrificial layer. An oxide, however, cannot be grown sufficiently thick to provide the desired actuation range for some applications of this structure.
One such application is micro-optical structures, such as micromirrors. While small deflections suffice for some micromirrors, large micromirrors (greater than about 300 um in diameter) require mirror rotations in the tens of microns (e.g., between about 50–80 um) to be useful. An oxide generally cannot provide for the needed separation between the device layer and the handle layer for such mirror rotations. Therefore, most large micromirrors are not made using the above-described structure. Alternative structures for large micromirrors, such as assembled, hinged or bimorph pop-up structures, have a number of disadvantages. They are often difficult to fabricate, are unreliable, provide low-yield and are many times unmanufacturable devices.
Prior art processes for forming micromirrors also suffer from other disadvantages. For example, many require a through-wafer etch to access the backside of structure. These through-wafer etches create fragile final chips. Etch holes through the mirror surface are often required for the release etch. These etch holes increase signal loss due to scattering. In addition, the prior art processes are not easily integrated with foundry electronics and cannot provide a single chip solution, i.e. one where no assembly is required of separate mirror and electronics chips. The prior art forms micro-optic MEMS systems by constructing the mirror structure on one chip, the electronics on a second chip and then using wire bonding to interface the two components to form the micro-optic system. Integration of active electronics on the same wafer as a micro-optical structure would provide a number of advantages.
SUMMARY OF THE INVENTION
In one aspect of the present invention, a method of fabricating a microelectromechanical system is provided. First, a substrate is provided that comprised a handle layer of silicon, a device layer of silicon and a sacrificial layer of silicon disposed between the handle layer and the device layer. Next, a micromechanical structure is formed in the device layer. Then, at least a portion of the sacrificial layer of silicon underlying the micromechanical structure is removed to release the micromechanical structure for movement.
In another aspect of the present invention, a method of releasing a micromechanical structure for movement is provided. The micromechanical structure is etched in a silicon device layer and a silicon sacrificial layer disposed between said micromechanical structure and a silicon handle layer is etched.
Another aspect of the present invention provides a microfabricated device. The microfabricated device comprises a substrate having a device layer; a least one micro-optical device etched on the device layer and released for movement by removal of an underlying sacrificial layer of silicon; and active electronics formed on the device layer.
Provided in another aspect of the present invention is a microelectromechanical device. The device comprises a handle layer of silicon having actuation electrodes formed thereon, a device layer of silicon having a micromechanical structure formed thereon and a sacrificial layer of silicon disposed between the handle layer and the device layer of silicon. The sacrificial layer of silicon has a portion underlying the micromechanical structure removed to form an actuation cavity below the micromechanical structure.
In another aspect, a micromirror device is provided. The micromirror device comprises a substrate having a device layer, a handle layer and a sacrificial layer made of silicon disposed between the device layer and the handle layer and an isolation trench extending through the device layer and the sacrificial layer. The isolation trench defines a mirror region and electrically isolates the mirror region. The micromirror device also comprises a mirror formed from the device layer in the mirror region above actuation electrodes formed on said handle layer. In addition, a cavity is formed below the mirror by removing a portion of said sacrificial layer of silicon.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 a – 1 d illustrate a preferred micromirror structure constructed according to the principles of the present invention in which single crystal silicon is used as the device layer;
FIGS. 2 a – 2 j illustrate the fabrication steps of the micromirror structure of FIGS. 1 a – 1 c;
FIG. 3 illustrates another embodiment of a micromirror structure constructed according to the principles of the present invention in which polycrystalline silicon is used as the device layer; and
FIGS. 4 a– 4 m illustrate the fabrication steps of the micromirror structure of FIG. 3 .
DETAILED DESCRIPTION OF THE INVENTION
While the various embodiments of the present invention are described with respect to, and some embodiments are particularly advantageous for, the production of micromirrors, the present invention is not limited thereto. As will be appreciated by one of skill in the art, the principles of the present invention are applicable to a number of other devices, such as inertial sensors, pressure sensors, and actuators.
FIGS. 1 a , 1 b and 1 c illustrate a preferred micromirror structure 100 constructed according to the principles of the present invention. FIGS. 1 a and 1 b illustrate top planar views of different layers of preferred micromirror structure 100 . FIG. 1 a illustrates a top planar view of the device layer of micromirror structure 100 . FIG. 1 b illustrates a top planar view of the handle layer of micromirror structure 100 . FIG. 1 c illustrates a side view of micromirror structure 100 .
Micromirror structure 100 is created from a substrate having a handle layer 120 , a sacrificial layer 122 and a device layer 124 , each separated by a dielectric, such as silicon dioxide. Single crystal silicon is used as sacrificial layer 122 in order to provide for greater distances between mirror 110 and handle layer 120 , and, in turn, a greater actuation range. Handle layer 120 and device layer 124 are also single crystal silicon. Significant advantages are obtained with device layer 124 being single crystal silicon. The use of single crystal silicon as device layer 124 provides for larger, flatter mirrors and provides a substrate that is compatible with traditional CMOS fabrication techniques. This allows for control and processing electronics 132 to be formed directly on the substrate. Therefore, it is possible to integrate active electronics on the same wafer as a micro-optical structure.
As illustrated, a mirror 110 , formed from device layer 124 , is suspended over a cavity created by the removal of sacrificial layer 122 underlying mirror 110 . Mirror 110 has a coating 130 thereon to increase the reflectivity. Mirror 110 is suspended by flexure connections 112 . Preferably, mirror 110 is connected to a concentric suspension ring 114 via a first set of flexures 112 a and concentric suspension ring 114 is connected to frame 118 via a second set of orthogonally oriented flexures 112 b . Preferably, flexures 112 are serpentine structures as illustrated in FIG. 1 d, which shows a close-up of one of the set of flexures 112 b.
An isolation trench 104 extends down to handle layer 120 from device layer 124 and surrounds the area containing mirror 110 and associated frame 118 . Isolation trench 104 electrically isolates micromirror structure 100 from the rest of the wafer. Further, as will be seen below, isolation trench 104 also acts as a lateral etch stop for the sacrificial layer etch and provides a mechanical anchor for mirror 110 .
Similar to isolation trench 104 , via posts 109 , filled with a conductive material such as doped polysilicon, extend through contact holes 108 down to handle layer 120 from device layer 124 . Via posts 109 connect to interconnects 106 formed on handle layer 120 . Interconnects 106 have pads at one end for connection to via posts 109 and are connected at the other end to actuation electrodes 121 formed on handle layer 120 . An electrical interconnection 116 formed on top of the device layer is used to apply a first voltage to the device layer of micromirror structure 100 . Electrical interconnections 134 connected to via posts 109 are then used to apply a second voltage to actuation electrodes 121 to move mirror 110 .
Referring to FIGS. 2 a and 2 b , the fabrication process for micromirror structure 100 begins with a single crystal silicon wafer 222 bonded using wafer bonding to a single crystal silicon wafer 220 , which has interconnects and actuation electrodes 206 formed thereon. Interconnects and actuation electrodes 206 are preferably formed using patterned polysilicon. However, other manners of forming interconnects and actuation electrodes 206 , such as patterned diffusions into wafer 220 , are possible. Alternatively, interconnects and electrodes 206 may be formed on the bottom of wafer 222 . Wafer 222 is ground to the desired sacrificial layer thickness (e.g., 50 um) using, for example, a combination of mechanical and chemical-mechanical polishing (CMP). A second wafer 224 is then bonded, also using wafer bonding, to wafer 222 and ground to the desired thickness (e.g., 10 um) of the mechanical structure and the circuits, also using, for example, a combination of mechanical and chemical-mechanical polishing (CMP).
This results in a substrate 200 comprised of a handle layer 220 of single crystal silicon, a sacrificial layer 222 of single crystal silicon and a device layer 224 of single crystal silicon. A first dielectric layer 203 separates sacrificial layer 222 and handle layer 220 and a second dielectric layer 205 separates device layer 224 from sacrificial layer 222 .
While described as being formed from three bonded silicon wafers, alternative techniques of forming three-layer substrate 200 are possible. One possible alternative entails wafer bonding a single silicon-on-insulator (SOI) wafer to dielectric layer 203 on wafer 220 . In this case, the silicon layer of the SOI wafer above the insulator is made to be the appropriate thickness before bonding and is sacrificial layer 222 . The handle layer of the SOI wafer is device layer 224 and is ground to the appropriate thickness after bonding.
Another possible alternative entails double bonding of two SOI wafers to wafer 220 . For this technique, a SOI wafer is bonded to wafer 220 and the handle layer of the SOI wafer is removed. This leaves sacrificial layer 222 and dielectric 205 . A second SOI wafer is then wafer bonded on top of dielectric 205 . The handle layer and insulator layer of the second SOI wafer is then removed to leave device layer 224 .
Referring next to FIGS. 2 b and 2 c , after the fabrication of three-layer substrate 200 , isolation trench 204 and contact holes 208 are etched through device layer 224 and sacrificial layer 222 , stopping at electrodes 206 . While shown as a single isolation trench 204 extending through both the sacrificial layer 222 and device layer 224 , the present invention is not limited thereto. For instance, an isolation trench may be formed in sacrificial layer 222 , but not device layer 224 and, likewise, an isolation trench may be formed in device layer 224 , but not sacrificial layer 222 . Or, two trenches that are not coincident may be formed in each of device layer 224 and sacrificial layer 222 .
Isolation trench 204 and contact holes 208 are lined with a dielectric 211 , such as a thermal oxide, and back-filled with conductive material, such as doped polysilicon. The doped polysilicon in contact holes 208 forms via posts 209 . In addition to providing electrical conductivity, the use of doped polysilicon also provides mechanical stiffness to micromirror structure 100 .
At this point substrate 200 is compatible with traditional CMOS circuit fabrication processes. For a typical CMOS fabrication process, the only differences between substrate 200 and normal starting material is that substrate 200 has trench isolation and comprises bonded wafers. Trench isolation and bonded wafers, however, are well-established processes in IC manufacturing. Therefore, standard processing with alignment to the trench features is preferably performed to form the integrated electronics 232 . Metal interconnects 216 and 234 are formed to connect to via posts 209 and the mirror region. At the completion of circuit formation, the substrate has a passivation layer 213 covering device layer 224 . As illustrated in FIGS. 2 e and 2 f , this passivation layer is next removed from the mirror area and the mirror 210 , concentric suspension ring 214 , frame 218 and flexures are patterned and etched in device layer 224 . Mirror 210 , concentric suspension ring 214 , frame 218 and flexures are etched in device layer 224 , for example, using a deep reactive ion etch stopping on second dielectric layer 205
Next, as shown in FIG. 2 g , a photoresist coating 207 is applied to substrate 200 and patterned. Release holes 215 are etched through photoresist coating 207 and second dielectric 205 to expose the silicon of sacrificial layer 222 .
As illustrated in FIG. 2 h , the silicon of sacrificial layer 222 bound by first dielectric layer 203 , second dielectric layer 205 and the dielectric lining isolation trench 204 is then isotropically etched through release holes 215 using, for example, a Xenon Diflouride (XeF 2 ) dry etch. Etching sacrificial layer 222 forms a cavity 217 underneath mirror 210 , concentric suspension ring 214 , frame 218 and the flexures. Formation of cavity 217 releases mirror 210 , concentric suspension ring 214 , frame 218 and the flexures for movement.
Referring to FIGS. 2 i and 2 j , the dielectric in cavity 217 is next removed by, for example, an oxide etch using Hydroflouric Acid (HF). This is followed by an oxygen plasma resist strip to remove photoresist coating 207 , which results in the structure as shown in FIG. 2 j . Finally, a layer of reflective material, preferably gold, is deposited and patterned on mirror 210 to complete the structure as shown in FIG. 1 c.
While it is preferable to place the coating on mirror 210 as the last step in fabrication, the reflective material can be deposited and etched on mirror 210 or mirror region during other times of the fabrication process. For instance, the reflective material can be placed on the mirror region of device layer 224 prior to the etching of mirror 210 , concentric suspension ring 214 and frame 218 and flexures. In this case, after circuit fabrication, part of passivation layer 213 is removed above the mirror region. A thin layer of reflective material, preferably gold, is deposited and patterned on the mirror region. Next, mirror 210 , concentric suspension ring 214 and frame 218 and flexures are patterned and etched in device layer 224 . The rest of the fabrication continues as previously described to the formation of cavity 217 and the corresponding oxide etch and photoresist strip.
FIG. 3 illustrates another embodiment of a micromirror structure 300 constructed according to the principles of the present invention. In the embodiment of FIG. 3 , polycrystalline silicon (“polysilicon”) is used as a device layer 324 instead of single crystal silicon. It should be noted that using polysilicon to form a micromirror will increase mirror roughness while reducing compatibility with standard CMOS fabrication. Polysilicon also increases mirror curvature because of stress gradients in the polysilicon. However, the use of polysilicon is advantageous at times because using polysilicon decreases the cost of fabricating the device.
As described, micromirror structure 300 is similar to micromirror structure 100 . Micromirror structure 300 is formed from a substrate having a handle layer 320 , a sacrificial layer 322 and device layer 324 . Handle layer is separated from sacrificial layer 322 by a first dielectric 303 , such as silicon dioxide. Polysilicon device layer 324 is separated from sacrificial layer 322 by a second dielectric 305 , such as silicon dioxide. Handle layer 320 and sacrificial layer 322 comprise single crystal silicon, while, as described above, device layer 324 comprises polysilicon.
As illustrated, a mirror 310 formed from polysilicon device layer 324 is suspended over a cavity created by the removal of sacrificial layer 322 underlying mirror 310 . Mirror 310 has a coating 330 thereon to increase the reflectivity. As with mirror 110 , mirror 310 is preferably connected to a concentric suspension ring 314 via a first set of flexures and concentric suspension ring 314 is connected to a frame 318 via a second set of orthogonally oriented flexures. An isolation trench 304 extends down to handle layer 320 through sacrificial layer 322 and surrounds the area containing mirror 310 and associated frame 318 . Isolation trench 304 is partially formed from a conductive material, such as doped polysilicon.
Similar to isolation trench 304 , via posts 309 , filled with a conductive material such as doped polysilicon, extend down through sacrificial layer 322 . Via posts 309 connect to interconnects 306 formed on handle layer 320 . Electrical interconnections 316 and 334 are formed on top of the device layer to apply the appropriate actuation voltages.
Fabrication of micromirror structure 300 is similar to the fabrication of micromirror structure 100 . Referring to FIGS. 4 a , 4 b , 4 c and 4 d , the fabrication process for micromirror structure 300 begins with interconnects and actuation electrodes 406 formed on a single crystal silicon wafer 420 . Interconnects and actuation electrodes 406 illustrated are formed using patterned deposits of polysilicon. However, as described above, other manners of forming interconnects and actuation electrodes 406 , such as patterned diffusions into silicon wafer 420 , are possible. A single crystal wafer 422 is bonded to wafer 420 using wafer bonding. Wafer 422 is ground to the desired sacrificial layer thickness using, for example, a combination of mechanical and chemical-mechanical polishing (CMP). Alternative techniques, similar to those described above may also be used to form two-layer substrate 400 .
Next, isolation trench 404 and via holes 408 are etched through wafer 422 , stopping at interconnects 406 . A dielectric, such as a thermal oxide, is grown on top of wafer 422 forming dielectric layer 405 and on the walls of isolation trench 404 and via holes 408 forming linings 411 . Anchor holes 421 , which will be used provide support to the mirror, are patterned and etched in dielectric layer 405 .
As illustrated in FIG. 4 e , a device layer 424 and via posts 409 are formed and isolation trenches are filled from polysilicon deposition on top of second dielectric layer 405 . Polysilicon forming the device layer is deposited to the desired device thickness. As shown in FIG. 4 f , device layer 424 is then etched to form interconnect features 419 and anchor features 423 .
A pre-metal dielectric deposition and contact etch is next performed, followed by a metal deposition and etch step and a passivation deposition step. As shown in FIG. 4 g , these steps form metal interconnects 416 and 434 covered by a passivation layer 413 .
As illustrated in FIGS. 4 h and 4 i, this passivation layer is next removed from the mirror area and the mirror 410 , concentric suspension ring 414 , frame 418 and flexures are patterned and etched in device layer 424 . Mirror 410 , concentric suspension ring 414 , frame 418 and flexures are etched in device layer 424 , for example, using a deep reactive ion etch stopping on second dielectric layer 405 .
Next, as shown in FIG. 4 j, a photoresist coating 407 is applied to substrate 400 and patterned. Release holes 415 are etched through photoresist coating 407 and second dielectric 405 to expose the silicon of sacrificial layer 422 .
As illustrated in FIG. 4 k , the silicon of sacrificial layer 422 bound by first dielectric layer 403 , second dielectric layer 405 and the dielectric lining isolation trench 404 is then isotropically etched through release holes 415 using, for example, a Xenon Diflouride (XeF 2 ) dry etch. Etching sacrificial layer 422 forms a cavity 417 underneath mirror 410 , frame 418 and the flexures. Formation of cavity 417 releases mirror 410 and the flexures for movement.
As illustrated in FIG. 4 l , the dielectric in cavity 417 is next removed by, for example, an oxide etch using hydrofluoric acid (HF). This is followed by an oxygen plasma resist strip to remove photoresist coating 407 to complete the structure as shown in FIG. 4 m. Finally, a layer of reflective material, preferably gold, is deposited and patterned on mirror 410 to complete the structure shown in FIG. 3 .
Although the present invention has been shown and described with respect to several preferred embodiments thereof, various changes, omissions and additions to the form and detail thereof, may be made therein, without departing from the spirit and scope of the invention.
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A microelectromechanical system is fabricated from a substrate having a handle layer, a silicon sacrificial layer and a device layer. A micromechanical structure is etched in the device layer and the underlying silicon sacrificial layer is etched away to release the micromechanical structure for movement. One particular micromechanical structure described is a micromirror.
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BACKGROUND OF THE INVENTION
This invention provides novel compositions of matter. This invention further provides novel processes for producing these compositions of matter. This invention further provides novel chemical intermediates useful in the above processes.
Particularly this invention provides novel analogs of some of the known prostaglandins which differ from corresponding known prostaglandins in that these prostaglandin analogs have a triple bond between C-13 and C-14, that is the C-13 to C-14 moiety is -C.tbd.C-.
The known prostaglandins include the PGE compounds, e.g. prostaglandin E 1 (PGE 1 ), prostaglandin E 2 (PGE 2 ), prostaglandin E 3 (PGE 3 ), and dihydroprostaglandin E 1 (dihydro-PGE 1 ).
The known prostaglandins include PGF.sub.α compounds, e.g. prostaglandin F 1 .sub.α (PGF 1 .sub.α), prostaglandin F 2 .sub.α (PGF 2 .sub.α), prostaglandin F 3 .sub.α (PGF 3 .sub.α), and dihydroprostaglandin F 1 .sub.α (dihydro-PGF 1 .sub.α).
The known prostaglandins include PGF.sub.β compounds, e.g. prostaglandin F 1 .sub.β (PGF 1 .sub.β), prostaglandin F 2 .sub.β (PGF 2 .sub.β), prostaglandin F 3 .sub.β (PGF 3 .sub.β), and dihydroprostaglandin F 1 .sub.β (dihydro-PGF 1 .sub.β).
The known prostaglandins include PGA compounds, e.g. prostaglandin A 1 (PGA 1 ), prostaglandin A 2 (PGA 2 ), prostaglandin A 3 (PGA 3 ), and dihydroprostaglandin A 1 (dihydro-PGA 1 ).
The known prostaglandins include PGB compounds, e.g. prostaglandin B 1 (PGB 1 ), prostaglandin B 2 (PGB 2 ), prostaglandin B 3 (PGB 3 ), and dihydroprostaglandin B 1 (dihydro-PGB 1 ).
Each of the above mentioned known prostaglandins (PG's) is a derivative of prostanoic acid which has the following structure and carbon atom numbering ##STR1## See, for example, Bergstrom et al., Pharmacol. Rev. 20, 1 (1968), and references cited therein. A systematic name for prostanoic acid is 7-[(2β-octyl)-cyclopent-1α-yl]-heptanoic acid.
PGE 1 has the following structure: ##STR2##
PGE 2 has the following structure: ##STR3##
PGE 3 has the following structure: ##STR4##
Dihydro-PGE 1 has the following structure: ##STR5##
PGF 1 .sub.α has the following structure: ##STR6##
PGF 2 .sub.α has the following structure: ##STR7##
PGF 3 .sub.α has the following structure: ##STR8##
Dihydro-PGF 1 .sub.α has the following structure: ##STR9##
PGF 1 .sub.β has the following structure: ##STR10##
PGF 2 .sub.β has the following structure: ##STR11##
PGF 3 .sub.β has the following structure: ##STR12##
Dihydro-PGF 1 .sub.β has the following structure: ##STR13##
PGA 1 has the following structure: ##STR14##
PGA 2 has the following structure: ##STR15##
PGA 3 has the following structure: ##STR16##
Dihydro-PGA 1 has the following structure: ##STR17##
PGB 1 has the following structure: ##STR18##
PGB 2 has the following structure: ##STR19##
PGB 3 has the following structure: ##STR20##
Dihydro-PGB 1 has the following structure: ##STR21##
In the above formulas, as well as in the formulas hereinafter given, broken line attachments to the cyclopentane ring indicate substituents in alpha configuration i.e., below the plane of the cyclopentane ring. Heavy solid line attachments to the cyclopentane ring indicate substituents in beta configuration, i.e., above the plane of the cyclopentane ring. The use of wavy lines (˜) herein will represent attachment of substituents in either the alpha or beta configuration or attachment in a mixture of alpha and beta configurations.
The side-chain hydroxy at C-15 in the above formulas is in S configuration. See, Nature 212, 38 (1966) for discussion of the stereochemistry of the prostaglandins. Expressions such as C-13, C-14, C-15, and the like, refer to the carbon atom in the prostaglandin analog which is in the position corresponding to the position of the same number in prostanoic acid.
Molecules of the known prostaglandins each have several centers of asymmetry, and can exist in racemic (optically inactive) form and in either of the two enantiomeric (optically active) forms, i.e. the dextrorotatory and levorotatory forms. As drawn, the above formulas each represent the particular optically active form of the prostaglandin as is obtained from mammalian tissues, for example, sheep vesicular glands, swine lung, or human seminal plasma, from carbonyl and/or double bond reduction of the prostaglandin so obtained. See, for example, Bergstrom et al., cited above. The mirror image of each of these formulas represents the other enantiomer of that prostaglandin. The racemic form of a prostaglandin contains equal numbers of both enantiomeric molecules, and one of the above formulas and the mirror image of that formula is needed to represent correctly the corresponding racemic prostaglandin. For convenience hereinafter, use of the term, prostaglandin or "PG" will mean the optically active form of that prostaglandin thereby referred to with the same absolute configuration as PGE 1 obtained from mammalian tissues. When reference to the racemic form of one of those prostaglandins is intended, the word "racemic" or "dl" will precede the prostaglandin name.
The term "prostaglandin-type" (PG-type) product, as used herein, refers to any cyclopentane derivative which is useful for at least one of the same pharmacological purposes as the prostaglandins, as indicated herein.
The term prostaglandin-type intermediate, as used herein, refers to any cyclopentane derivative useful in preparing a prostaglandin-type product.
The formulas, as drawn herein, which depict a prostaglandin-type product or an intermediate useful in preparating a prostaglandin-type product, each represent the particular stereoisomer of the prostaglandin-type product which is of the same relative stereochemical configuration as a corresponding prostaglandin obtained from mammalian tissues, or the particular stereoisomer of the intermediate which is useful in preparing the above stereoisomer of the prostaglandin-type product.
The term "prostaglandin analog", as used herein, represents that stereoisomer of a prostaglandin-type product which is of the same relative stereochemical configuration as a corresponding prostaglandin obtained from mammalian tissues or a mixture comprising that stereoisomer and the enantiomer thereof. In particular, where a formula is used to depict a prostaglandin-type compound herein, the term prostaglandin analog refers to the compound of that formula, or a mixture comprising that compound and the enantiomer thereof.
The various PG's named above, their esters, acylates and pharmacologically acceptable salts, are extremely potent in causing various biological responses. For that reason, these compounds are useful for pharmacological purposes. See, for example, Bergstrom et al., Pharmacol. Rev. 20, 1 (1968) and references cited therein.
For the PGE compounds these biological responses include:
a. decreasing blood pressure (as measured, for example, in anesthetized, pentolinium-treated rats);
b. stimulating smooth muscle (as shown by tests, for example, on guinea pig ileum, rabbit duodenum, or gerbil colon);
c. effecting lipolytic activity (as shown by antagonism of epinephrine induced release of glycerol from isolated rat fat pads);
d. inhibiting gastric secretion and reducing undesirable gastrointestinal effects from systematic administration of prostaglandin synthetase inhibitors;
e. controlling spasm and facilitating breathing in asthmatic conditions;
f. decongesting nasal passages;
g. decreasing blood platelet adhesion (as shown by platelet to glass adhesiveness) and inhibiting blood platelet aggregation and thrombus formation induced by various physical stimuli (e.g., arterial injury) or chemical stimuli (e.g., ATP, ADP, serotinin, thrombin, and collagen);
h. affecting the reproductive organs of mammals as labor inducers, abortifacients, cervical dilators, regulators of the estrus, and regulators of the menstrual cycle; and
j. accelerating growth of epidermal cells and keratin in animals.
For the PGF.sub.α compound these biological responses include:
a. increasing blood pressure (as measured, for example, in anesthetized, pentolinium-treated rats);
b. stimulating smooth muscle (as shown by tests on guinea pig ileum, rabbit duodenum, or gerbil colon);
c. inhibiting gastric secretion and reducing undesirable gastrointestinal effects from systematic administration of prostaglandin synthetase inhibitors;
d. controlling spasm and facilitating breathing in asthmatic conditions;
e. decongesting nasal passages;
f. decreasing blood platelet adhesion (as shown by platelet to glass adhesiveness) and inhibiting blood platelet aggregation and thrombus formation induced by various physical stimuli (e.g., arterial injury) or chemical stimuli (e.g., ADP, ATP, serotinin, thrombin, and collagen); and
g. affecting the reproductive organs of mammals as labor inducers, abortifacients, cervical dilators, regulators of the estrus, and regulators of the menstral cycle.
For the PGF.sub.β compounds these biological responses include:
a. decreasing blood pressure (as measured, for example, in anesthetized, pentolinium-treated rats);
b. stimulating smooth muscle (as shown by tests on guinea pig ileum, rabbit duodenum, or gerbil colon);
c. inhibiting gastric secretion and reducing undesirable gastrointestinal effects from systematic administration of prostaglandin synthetase inhibitors;
d. controlling spasm and facilitating breathing in asthmatic conditions;
e. decongesting nasal passages;
f. decreasing blood platelet adhesion (as shown by platelet to glass adhesiveness) and inhibiting blood platelet aggregation and thrombus formation induced by various physical stimuli (e.g., arterial injury) or chemical stimuli (e.g., ADP, ATP, serotinin, thrombin, and collagen); and
g. affecting the reproductive organs of mammals as labor inducers, abortifacients, cervical dilators, regulators of the estrus, and regulators of the menstrual cycle.
For the PGA compounds these biological responses include:
a. decreasing blood pressure (as measured, for example, in anesthetized, pentolinium-treated rats);
b. stimulating smooth muscle (as shown by tests on guinea pig ileum, rabbit duodenum, or gerbil colon);
c. inhibiting gastric secretion and reducing undesirable gastrointestinal effects from systematic administration of prostaglandin synthetase inhibitors;
d. controlling spasm and facilitating breathing in asthmatic conditions;
e. decongesting nasal passages; and
f. increasing kidney blood flow.
For the PGB compounds these biological responses include:
a. stimulating smooth muscle (as shown by tests on guinea pig ileum, rabbit duodenum, or gerbil colon); and
b. accelerating growth of epidermal cells and keratin in animals.
Because of these biological responses, these known prostaglandins are useful to study, prevent, control, or alleviate a wide variety of diseases and undesirable physiological conditions in birds and mammals, including humans, useful domestic animals, pets, and zoological specimens, and in laboratory animals, for example, mice, rats, rabbits, and monkeys.
The prostaglandins so cited above as hypotensive agents are useful to reduce blood pressure in mammals, including man. For this purpose, the compounds are administered by intravenous infusion at the rate about 0.01 to about 50 μg. per kg. of body weight per minute or in single or multiple doses of about 25 to 500 μg. per kg. of body weight total per day.
The PGF.sub.α compounds are useful in increasing blood pressure in mammals, including man. Accordingly, these compounds are useful in the treatment of shock (hemorrhagic shock, endotoxin shock, cardiogenic shock, surgical shock, or toxic shock). Shock is marked by pallor and clamminess of the skin, decreased blood pressure, feeble and rapid pulse, decreased respiration, restlessness, anxiety, and sometimes unconsciousness. Shock usually follows cases of injury and trauma. Expert and fast emergency measures are required to successfully manage such shock conditions. Accordingly, prostaglandins, combined with a pharmaceutical carrier which adapts the prostaglandin for intramuscular, intravenous, or subcutaneous use, are useful, especially in the early stages of shock where the need to increase blood pressure is a critical problem, for aiding and maintaining adequate blood flow, perfusing the vital organs, and exerting a pressor response by constricting veins and raising blood pressure to normal levels. Accordingly, these prostaglandins are useful in preventing irreversible shock which is characterized by a profound fall in blood pressre, dilation of veins, and venus blood pooling. In the treatment of shock, the prostaglandin is infused at a dose of 0.1 - 25 mcg./kg./min. The prostaglandin may advantageously be combined with known vasoconstrictors; such as phenoxy-benzamine, norepinephrine, and the like. Further, when used in the treatment of shock the prostaglandin is advantageously combined with steroids (such as, hydrocortisone or methylprednisolone), tranquilizers, and antibiotics (such as, lincomycin or clindamycin).
The compounds so cited above as extremely potent in causing stimulation of smooth muscle are also highly active in potentiating other known smooth muscle stimulators, for example, oxytocic agents, e.g., oxytocin, and the various ergot alkaloids including derivatives and analogs thereof. Therefore, these compounds for example, are useful in place of or in combination with less than usual amounts of these known smooth muscle stimulators, for example, to relieve the symptoms of paralytic ileus, or to control or prevent atonic uterine bleeding after abortion or delivery, to aid in expulsion of the placenta, and during the puerperium. For the latter purpose, the prostaglandin is administered by intravenous infusion immediately after abortion or delivery at a dose in the range about 0.01 to about 50 μg. per kg. of body weight per minute until the desired effect is obtained. Subsequent doses are given by intravenous, subcutaneous, or intramuscular injection or infusion during puerperium in the range 0.01 to 2 mg. per kg. of body weight per day, the exact dose depending on the age, weight, and condition of the patient or animal.
As mentioned above, the PGE compounds are potent antagonists of epinephrine-induced mobilization of free fatty acids. For this reason, this compound is useful in experimental medicine for both in vitro and in vivo studies in mammals, including man, rabbits, and rats, intended to lead to the understanding, prevention, symptom alleviation, and cure of diseases involving abnormal lipid mobilization and high free fatty acid levels, e.g., diabetes mellitus, vascular diseases, and hyperthyroidism.
The prostaglandins so cited above as useful in mammals, including man and certain useful animals, e.g. dogs and pigs, to reduce and control excessive gastric secretion, thereby reduce or avoid gastrointestinal ulcer formation, and accelerate the healing of such ulcers already present in the gastrointestinal tract. For this purpose, these compounds are injected or infused intravenously, subcutaneously, or intramuscularly in an infusion dose range about 0.1 μg. to about 500 μg. per kg. of body weight per minute, or in a total daily dose by injection or infusion in the range about 0.1 to about 20 mg. per kg. of body weight per day, the exact dose depending on the age, weight, and condition of the patient or animal, and on the frequency and route of administration.
These compounds are also useful in reducing the undesirable gastrointestinal effects resulting from systemic administration of anti-inflammatory prostaglandin synthetase inhibitors, and are used for that purpose by concomitant administration of the prostaglandin and the antiinflammatory prostaglandin synthetase inhibitor. See Partridge et al., U.S. Pat. No. 3,781,429, for a disclosure that the ulcerogenic effect induced by certain non-steroidal anti-inflammatory agents in rats is inhibited by concomitant oral administration of certain prostaglandins of the E and A series, including PGE 1 , PGE 2 , PGE 3 , 13,14-dihydro-PGE 1 , and the corresponding 11-deoxy-PGE and PGA compounds. Prostaglandins are useful, for example, in reducing the undesirable gastrointestinal effects resulting from systemic administration of indomethacin, phenylbutazone, and aspirin. These are substances specifically mentioned in Partridge et al. as non-steroidal, anti-inflammatory agents. These are also known to be prostaglandin synthetase inhibitors.
The anti-inflammatory synthetase inhibitor, for example, indomethacin, aspirin, or phenylbutazone is administered in any of the ways known in the art to alleviate an inflammatory condition, for example, in any dosage regimen and by any of the known routes of systemic administration.
The prostaglandin is administered along with the antiinflammatory prostaglandin synthetase inhibitor either by the same route of administration or by a different route. For example, if the anti-inflammatory substance is being administered orally, the prostaglandin is also administered orally or, alternatively, is administered rectally in the form of a suppository or, in the case of women, vaginally in the form of a suppository or a vaginal device for slow release, for example as described in U.S. Pat. No. 3,545,439. Alternatively, if the anti-inflammatory substance is being administered rectally, the prostaglandin is also administered rectally. Further, the prostaglandin can be conveniently administered orally or, in the case of women, vaginally. It is especially convenient when the administration route is to be the same for both anti-inflammatory substance and prostaglandin, to combine both into a single dosage form.
The dosage regimen for the prostaglandin in accord with this treatment will depend upon a variety of factors, including the type, age, weight, sex and medical condition of the mammal, the nature and dosage regimen of the antiinflammatory synthetase inhibitor being administered to the mammal, the sensitivity of the particular individual mammal to the particular synthetase inhibitor with regard to gastrointestinal effects, and the particular prostaglandin to be administered. For example, not every human in need of an anti-inflammatory substance experiences the same adverse gastrointestinal effects when taking the substance. The gastrointestinal effects will frequently vary substantially in kind and degree. But it is within the skill of the attending physician or veterinarian to determine that administration of the anti-inflammatory substance is causing undesirable gastrointestinal effects in the human or animal subject and to prescribe an effective amount of the prostaglandin to reduce and then substantially to eliminate those undesirable effects.
The prostaglandins so cited above as useful in the treatment of asthma, are useful, for example, as bronchodilators or as inhibitors of mediators, such as SRS-A, and histamine which are released from cells activated by an antigen-antibody complex. Thus, these compounds control spasm and facilitate breathing in conditions such as bronchial asthma, bronchitis, bronchiectasis, pneumonia, and emphysema. For these purposes, the compounds are administered in a variety of dosage forms, e.g., orally in the form of tablets, capsules, or liquids; rectally in the form of suppositories; parenterally, subcutaneously; or intramuscularly; with intravenous administration being preferred in emergency situations; by inhalation in the form of aerosols or solutions for nebulizers; or by insufflation in the form of powder. Doses in the range of about 0.01 to 5 mg. per kg. of body weight are used 1 to 4 times a day, the exact dose depending on the age, weight, and condition of the patient and on the frequency and route of administration. For the above use these prostaglandins can be combined advantageously with other anti-asthmatic agents, such as sympathomimetics (isoproterenol, phenylephrine, epinephrine, etc.); xanthine derivatives (theophylline and aminophylline); and corticosteroids (ACTH and prednisolone). Regarding use of thses compounds see M. E. Rosenthale, et al., U.S. Pat. No. 3,644,638.
The prostaglandins so cited above as useful in mammals, including man, as nasal decongestants are used for this purpose, in a dose range of about 10 μg. to about 10 mg. per ml. of a pharmacologically suitable liquid vehicle or as an aerosol spray, both for topical application.
The prostaglandins so cited above are useful whenever it is desired to inhibit platelet aggregation, reduce the adhesive character of platelets, and remove or prevent the formation of thrombi in mammals, including man, rabbits, and rats. For example, these compounds are useful in the treatment and prevention of myocardial infarcts, to treat and prevent post-operative thrombosis, to promote patency of vascular grafts following surgery, and to treat conditions such as atherosclerosis, arteriosclerosis, blood clotting defects due to lipemia, and other clinical conditions in which the underlying etiology is associated with lipid imbalance or hyperlipidemia. For these purposes, these compounds are administered systemically, e.g., intravenously, subcutaneously, intramuscularly, and in the form of sterile implants for prolonged action. For rapid response, especially in emergency situations, the intravenous route of adminstration is preferred. Doses in the range about 0.005 to about 20 mg. per kg. of body weight per day are used, the exact dose depending on the age, weight, and condition of the patient or animal, and on the frequency and route of administration.
These compounds are further useful as additives to blood, blood products, blood substitutes, or other fluids which are used in artificial extracorporeal circulation or perfusion of isolated body portions, e.g., limbs and organs, whether attached to the original body, detached and being preserved or prepared for transplant, or attached to a new body. During these circulations and perfusions, aggregated platelets tend to block the blood vessels and portions of the circulation apparatus. This blocking is avoided by the presence of these compounds. For this purpose, the compound is added gradually or in single or multiple portions to the circulating blood, to the blood of the donor animal, to the perfused body portion, attached or detached, to the recipient, or to two or all of those at a total steady state dose of about 0.0001 to 10 mg. per liter of circulating fluid. It is especially useful to use these compounds in laboratory animals, e.g., cats, dogs, rabbits, monkeys, and rats, for these purposes in order to develop new methods and techniques for organ and limb transplants.
The prostaglandins so cited above as useful in place of oxytocin to induce labor are used in pregnant female animals including man, cows, sheep, and pigs, at or near term, or in pregnant animals with intrauterine death of the fetus from about 20 weeks to term. For this purpose, the compound is infused intravenously at a dose of 0.01 to 50 μg. per kg. of body weight per minute until or near the termination of the second stage of labor, i.e., expulsion of the fetus. These compounds are especially useful when the female is one or more weeks post-mature and natural labor has not started, or 12 to 60 hours after the membranes have ruptured and natural labor has not yet started. An alternative route of administration is oral.
These compounds are further useful for controlling the reproductive cycle in menstruating female mammals, including humans. By the term menstruating female mammals is meant animals which are mature enough to menstruate, but not so old that regular menstruation has ceased. For that purpose the prostaglandin is administered systemically at a dose level in the range 0.01 mg. to about 20 mg. per kg. of body weight of the female mammal, advantageously during a span of time starting approximately at the time of ovulation and ending approximately at the time of menses or just prior to menses. Intravaginal and intrauterine routes are alternate methods of administration. Additionally, expulsion of an embryo or a fetus is accomplished by similar administration of the compound during the first or second trimester of the normal mammal gestation period.
These compounds are further useful in causing cervical dilation in pregnant and nonpregnant female mammals for purposes of gynecology and obstetrics. In labor induction and in clinical abortion produced by these compounds, cervical dilation is also observed. In cases of infertility, cervical dilation produced by these compounds is useful in assisting sperm movement to the uterus. Cervical dilation by prostaglandins is also useful in operative gynecology such as D and C (Cervical Dilation and Uterine Curettage) where mechanical dilation may cause perforation of the uterus, cervical tears, or infections. It is also useful in diagnostic procedures where dilation is necessary for tissue examination. For these purposes, the prostaglandin is administered locally or systemically.
The prostaglandin, for example, is administered orally or vaginally at doses of about 5 to 50 mg. per treatment of an adult female human, with from one to five treatments per 24 hour period. Alternatively the prostaglandin is administered intramuscularly or subcutaneously at doses of about one to 25 mg. per treatment. The exact dosages for these purposes depend on the age, weight, and condition of the patient or animal.
These compounds are further useful in domestic animals as an abortifacient (especially for feedlot heifers), as an aid to estrus detection, and for regulation or synchronization of estrus. Domestic animals include horses, cattle, sheep, and swine. The regulation or synchronization of estrus allows for more efficient management of both conception and labor by enabling the herdsman to breed all his females in short pre-defined intervals. This synchronization results in a higher percentage of live births than the percentage achieved by natural control. The prostaglandin is injected or applied in a feed at doses of 0.1-100 mg. per animal and may be combined with other agents such as steroids. Dosing schedules will depend on the species treated. For example, mares are given the prostaglandin 5 to 8 days after ovulation and return to estrus. Cattle, are treated at regular intervals over a 3 week period to advantageously bring all into estrus at the same time.
The PGA compounds and derivatives and salts thereof increase the flow of blood in the mammalian kidney, thereby increasing volume and electrolyte content of the urine. For that reason, PGA compounds are useful in managing cases of renal dysfunction, especially those involving blockage of the renal vascular bed. Illustratively, the PGA compounds are useful to alleviate and correct cases of edema resulting, for example, from massive surface burns, and in the management of shock. For these purposes, the PGA compounds are preferably first administered by intravenous injection at a dose in the range 10 to 1000 μg. per kg. of body weight or by intravenous infusion at a dose in the range 0.1 to 20 μg. per kg. of body weight per minute until the desired effect is obtained. Subsequent doses are given by intravenous, intramuscular, or subcutaneous injection or infusion in the range 0.05 to 2 mg. per kg. of body weight per day.
The compounds so cited above as promoters and acceleraters of growth of epidermal cells and keratin are useful in animals, including humans, useful domestic animals, pets, zoological specimens, and laboratory animals for this purpose. For this reason, these compounds are useful to promote and accelerate healing of skin which has been damaged, for example, by burns, wounds, and abrasions, and after surgery. These compounds are also useful to promote and accelerate adherence and growth of skin autografts, especially small, deep (Davis) grafts which are intended to cover skinless areas by subsequent outward growth rather than initially, and to retard rejection of homografts.
For the above purposes, these compounds are preferably administered topically at or near the side where cell growth and keratin formation is desired, advantageously as an aerosol liquid or micronized powder spray, as an isotonic aqueous solution in the case of wet dressings, or as a lotion, cream, or ointment in combination with the usual pharmaceutically acceptable diluents. In some instances, for example, when there is substantial fluid loss as in the case of extensive burns or skin loss due to other causes, systemic administration is advantageous, for example, by intravenous injection or infusion, separately or in combination with the usual infusions of blood, plasma, or substitutes thereof. Alternative routes of administration are subcutaneous or intramuscular near the site, oral, sublingual, buccal, rectal, or vaginal. The exact dose depends on such factors as the route of administration, and the age, weight, and condition of the subject. To illustrate, a wet dressing for topical application to second and/or third degree burns of skin area 5 to 25 square centimeters would advantageously involve use of an isotonic aqueous solution containing 1 to 500 μg. per ml. of the prostaglandin. Especially for topical use, these prostaglandins are useful in combination with antibiotics, for example, gentamycin, neomycin, polymixin, bacitracin, spectinomycin, and oxytetracycline, with other antibacterials, for example, mafenide hydrochloride, sulfadiazine, furazolium chloride, and nitrofurazone, and with corticoid steroids, for example, hydrocortisone, prednisolone, methylprednisolone, and fluprednisolone, each of those being used in the combination at the usual concentration suitable for its use alone.
Certain PG 2 -type compounds wherein the C-13 to C-14 moiety is --C.tbd.C-- are known in the art. For example, see Gandolfi C., et al., Il Farmaco, 27, 1125, wherein 13,14-didehydro-PGF 2 .sub.α and 13,14-didehydro-PGE 2 and their 15-epimers are described. See further, South African Pat. No. 73-2329, Derwent Farmdoc CPI 54179U, wherein 13,14-didehydro-PGF 2 .sub.α -, PGF 2 .sub.β -, PGE 2 -, and PGA 2 -type compounds are disclosed with optional C-16 alkyl substitution and with optional oxa or thia substitution at the C-3 position. Further, the above South African Patent discloses the 8β,12α-stereoisomer of the above-described compounds. See also J. Fried, et al., Tetrahedron Letters, 3899 (1963), which discloses 13,14-dihydro-PGF 2 .sub.α.
Additionally certain 13-didehydro-PG 1 -type compounds are known in the prior art. See, for example, J. Fried, et al., Annals, of the New York Academy of Science 18, 38 (1971), which discloses 7-oxa-13,14-didehydro-PGF 1 .sub.α. See also R. Pappo, et al., Tetrahedron Letters, 2627, 2630 (1972), which discloses racemic 13,14-dihydro-11β-PGE 1 ; and R. Pappo, et al., Annals. of the New York Academy of Science 18, 64 (1971), which discloses 13,14-didehydro-11β-PGB 1 . Finally, see the following patents which disclose 13,14-dihydro-PGB 1 -type compounds: Belgian Pat. No. 777,022 (Derwent Farmdoc CPI 43791T) German Offenlegungsschrift No. 1,925,672 (Derwent Farmdoc CPI 41,084), and German Offenlegungsschrift 2,357,781 (Derwent Farmdoc 42046V).
SUMMARY OF THE INVENTION
This invention provides novel prostaglandin analogs, esters of these analogs, and pharmacologically acceptable salts of these analogs.
This invention further provides lower alkanoates of these analogs.
This invention further provides novel processes for preparing these analogs.
This invention further provides novel chemical intermediates useful in the preparation of these analogs.
The present invention discloses:
(1) a prostaglandin analog of the formula ##STR22## wherein Y 1 is --C.tbd.C--; wherein g is one, 2, or 3;
wherein m is one to 5, inclusive;
wherein M 1 is ##STR23## or wherein R 5 and R 6 are hydrogen or methyl, with the proviso that one of R 5 and R 6 is methyl only when the other is hydrogen;
wherein L 1 is ##STR24##
or a mixture of ##STR25##
and ##STR26## wherein R 3 and R 4 are hydrogen, methyl, or fluoro, being the same or different, with the proviso that one of R 3 and R 4 is fluoro only when the other is hydrogen or fluoro;
wherein R 1 is hydrogen, alkyl of one to 12 carbon atoms, inclusive, cycloalkyl of 3 to 10 carbon atoms, inclusive, aralkyl of 7 to 12 carbon atoms, inclusive, phenyl, phenyl substituted with one, two, or three chloro or alkyl of one to 3 carbon atoms, inclusive, or a pharmacologically acceptable cation;
2. a prostaglandin analog of the formula: ##STR27## wherein ##STR28## wherein L 1 , R 1 , Y 1 , g, and m are as defined above; and wherein M 2 is ##STR29##
3. a prostaglandin analog of the formula: ##STR30## wherein ##STR31## wherein L 1 , M 1 , R 1 , Y 1 , and g are as defined above;
4. a prostaglandin analog of the formula ##STR32## wherein ##STR33## wherein L 1 , M 1 , R 1 , and Y 1 are as defined above; wherein Z 1 is
1. cis-CH=CH--CH 2 --(CH 2 ) g --CH 2 --,
2. cis-CH=CH-CH 2 -(CH 2 ) g -CF 2 -,
3. cis-CH 2 -CH=CH-(CH 2 ) g -CH 2 -,
4. -(ch 2 ) 3 -(ch 2 ) g -CH 2 -,
5. -(ch 2 ) 3 -(ch 2 ) g -CF 2 -,
6. -ch 2 -o-ch 2 -(ch 2 ) g -CH 2 -, (7) -(CH 2 ) 2 -O-(CH 2 ) g -CH 2 -,
8. -(ch 2 ) 3 -o-(ch 2 ) g -,
9. ##STR34## 10. ##STR35## wherein g is as defined above; wherein R 7 is,
1. --(CH 2 ) m --CH 3 ,
2. ##STR36## 3. ##STR37## 4. cis--CH=CH--CH 2 --CH 3 , wherein m is one to 5, inclusive, T is chloro, fluoro, trifluoromethyl, alkyl of one to 3 carbon atoms, inclusive, or alkoxy of one to 3 carbon atoms, inclusive, and s is zero, one, 2, or 3, the various T's being the same or different, with the proviso that not more than two T's are other than alkyl, with the further proviso that R 7 is ##STR38## wherein T and s are as defined above, only when R 3 and R 4 are hydrogen and methyl, being the same or different; and
5. a prostaglandin analog of the formula ##STR39## wherein ##STR40## is ##STR41## wherein L 1 , M 1 , R 1 , R 7 , Y 1 , and Z 1 are as defined above; with the proviso that Z 1 is cis-CH=CH--CH 2 --(CH 2 ) g --CH 2 --or --(CH 2 ) 3 --(CH 2 ) g --CH 2 --, only when R 7 is ##STR42## or ##STR43## where T and s are as defined above.
Within the scope of the novel prostaglandin analogs of this invention, there are represented above:
a. PGE-type compounds when the cyclopentane moiety is: ##STR44##
b. PGE.sub.α-type compounds when the cyclopentane moiety is: ##STR45##
c. PGF.sub.β-type compounds when the cyclopentane moiety is: ##STR46##
d. PGA-type compounds when the cyclopentane moiety is: ##STR47##
e. PGB-type compounds when the cyclopentane moiety is: ##STR48##
f. 11-deoxy-PGE-type compounds when the cyclopentane moiety is: ##STR49##
g. 11-deoxy-PGF.sub.α-type compounds when the cyclopentane moiety is: ##STR50##
h. 11-deoxy-PGF.sub.β-type compounds when the cyclopentane moiety is: ##STR51##
i. 8β,12α-PGE-type compounds when the cyclopentane moiety is: ##STR52##
j. 8β,12α-PGF.sub.α-type compounds when the cyclopentane moiety is: ##STR53##
k. 8β,12α-PGF.sub.β-type compounds when the cyclopentane moiety is: ##STR54##
l. 8β,12α-PGA-type compounds when the cyclopentane moiety is: ##STR55##
m. 8β,12α-11-deoxy-PGF.sub.β-type compounds when the cyclopentane moiety is: ##STR56##
n. 8β,12α-11-deoxy-PGE-type compounds when the cyclopentane moiety is: ##STR57## and
o. 8β,12α-11-deoxy-PGF.sub.α-type compounds when the cyclopentane moiety is: ##STR58##
Those prostaglandin analogs herein wherein Z 1 is cis--CH=CH--CH 2 --(CH 2 ) g --CH 2 --or cis --CH=CH--CH 2 --(CH 2 ) g --CF 2 -- are named as "PG 2 " compounds. The latter compounds are further characterized as "2,2-difluoro" PG-type compounds. When g is 2 or 3, the prostaglandin analogs so described are "2a-homo" or "2a,2b-dihomo" compounds, since in this event the carboxy terminated side chain contains 8 or 9 carbon atoms, respectively, in place of the 7 carbon atoms contained in PGE 1 . These additional carbon atoms are considered as though they were inserted between the C-2 and C-3 positions. Accordingly, these additional carbon atoms are referred to as C-2a and C-2b, counting from the C-2 to the C-3 position.
Further when Z 1 is --(CH 2 ) 3 --(CH 2 ).sub. g --CH 2 -- or --(CH 2 ) 3 --(CH 2 ) g --CF 2 , wherein g is as defined above, the compounds so described are "PG 1 " compounds. When g is 2 or 3, the "2a-homo" and "2a,2b-dihomo" compounds are described as is discussed in the preceding paragraph.
When Z 1 is --CH 2 --O--CH 2 --(CH 2 ) g --CH 2 -- the compounds so described are named as "5-oxa-PG 1 " compounds. When g is 2 or 3, the compounds so described are "2a-homo" or "2a,2b-dihomo" compounds, respectively, as discussed above.
When Z 1 is --(CH 2 ) 2 --O--(CH 2 ) g--CH 2 --, wherein g is as defined above, the compounds so described are named as "4-oxa-PG 1 " compounds. When g is 2 or 3, the compounds so described are additionally characterized as "2a-homo" or "2a,2b-dihomo" compounds, respectively, as is discussed above.
When Z 1 is --(CH 2 ) 3 --O--(CH 2 ) g --, wherein g is as defined above, the compounds so described are named as "3-oxa-PG 1 " compounds. When g is 2 or 3, the compounds so described are further characterized as "2a-homo" or "2a,2b-dihomo" compounds, respectively, as is discussed above.
When Z 1 is cis--CH 2 --CH=CH--(CH 2 ) g --CH 2 --, wherein g is as defined above, the compounds so described are named "cis-4,5-didehydro-PG 1 " compounds. When g is 2 or 3, the compounds so described are further characterized as "2a-homo" or "2a,2b-dihomo" compounds, respectively, as discussed above.
For the novel compounds of this invention wherein Z 1 is ##STR59## or ##STR60## there are described, respectively, 3-oxa-3,7-inter-m-phenylene-4,5,6-trinor- or 3,7-inter-m-phenylene-4,5,6-trinor-PG-type compounds, when g is 1. When g is 2 or 3, the above compounds are additionally described as "2a-homo" or "2a,2b-dihomo" PG-type compounds, respectively.
The novel prostaglandin analogs of this invention contain a --C.tbd.C-- moiety at the C-13 to C-14 position, and are accordingly, referred to as "13,14-didehydro" compounds.
When R 7 is --(CH 2 ) m --CH 3 , wherein m is as defined above, the compounds so described are named as "19,20-dinor,", "20-nor", "20-methyl", or "20-ethyl" compounds when m is one, 2, 4, or 5, respectively.
When R 7 is ##STR61## wherein T and s are as defined above, the compounds so described are named as "17-phenyl-18,19,20-trinor" compounds, when s is 0. When s is one, 2, or 3, the corresponding compounds are named as "17-(substituted phenyl)18,19,20-trinor" compounds. When R 7 is ##STR62## wherein T and s are as defined above, and neither R 3 nor R 4 is methyl, the compounds so described are named as "16-phenoxy-17,18,19,20-tetranor" compounds, when s is zero. When s is one, 2, or 3, the corresponding compounds are named as "16-(substituted phenoxy)-17,18,19,20-tetranor" compounds. When one and only one of R 3 and R 4 is methyl or both R 3 and R 4 are methyl, then the corresponding compounds wherein R 7 is as defined in this paragraph are named as "16-phenoxy or 16-(substituted phenoxy)-18,19,20-trinor" compounds or "16-methyl-16-phenoxy- or 16-(substituted phenoxy)-18,19,20-trinor" compounds, respectively.
When R 7 is cis--CH=CH--CH 2 --CH 3 , the compounds so described are "PG 3 " or "17,18-didehydro-PG 1 " compounds depending on whether Z 1 is cis-CH=CH-(CH 2 ) g -C(R 2 ) 2 , wherein R 2 is hydrogen or fluoro; or another moiety, respectively.
When at least one of R 3 and R 4 is not hydrogen then (except for the 16-phenoxy compounds discussed above) there are described the "16-methyl" (one and only one of R 3 and R 4 is methyl), "16,16-dimethyl" (R 3 and R 4 are both methyl), "16-fluoro" (one and only one of R 3 and R 4 is fluoro), "16,16-difluoro" (R 3 and R 4 are both fluoro) compounds. For those compounds wherein R 3 and R 4 are different, the prostaglandin analogs so represented contain an asymmetric carbon atom at C-16. Accordingly, two epimeric configurations are possible: "(16S)" and "(16R)". Further, there is described by this invention the C-16 epimeric mixture: "(16RS)".
When R 5 is methyl, the compounds so described are named as "15-methyl" compounds. When R 6 is methyl, the compounds so described are named as "15-methyl ether " compounds.
There is further provided by this invention both epimeric configurations of the hydroxy or methoxy at C-15. As discussed herein, PGE 1 , as obtained from mammalian tissues, has the "S" configuration at C-15, Further, as drawn herein PGE 1 , as obtained from mammalian tissues, has the 15-hydroxy moiety in the "alpha" configuration.
For the 13,14-didehydro derivative of PGE 1 as obtained from mammalian tissues, the S configuration at C-15 represents the α-hydroxy configuration, using the convention by which the side chains of the novel prostaglandin analogs of this invention are drawn herein, as indicated above. Further, (15R)-PGE 1 , by the convention used for drawing the prostaglandins herein, has the 15-hydroxy substituent in the beta configuration. The corresponding (15R)-13,14-didehydro-PGE 1 compound, drawn using the convention herein for the representation of the novel prostaglandin analogs of this invention, likewise has the 15-hydroxy in the beta configuration. Thus, the novel prostaglandin analogs of this invention wherein the 15-hydroxy or 15-methoxy moiety has the same absolute configuration as (15R)-13,14-didehydro-PGE 1 at C-15 will be named "15-epi" compounds. When the designation "15-epi" is absent, those compounds wherein the configuration of the 15-hydroxy or 15-methoxy is the same as the absolute configuration of 15(S)-13,14-didehydro-PGE 1 are represented, i.e. the 15α-hydroxy configuration.
Accordingly, as indicated by the preceeding paragraphs, the novel PG analogs disclosed herein are named according to the system described in Nelson, N.A., J. Med. Chem. 17, 911 (1974).
Examples of alkyl of one to 12 carbon atoms, inclusive, are methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, and isomeric forms thereof.
Examples of cycloalkyl of 3 to 10 carbon atoms, inclusive, which includes alkyl-substituted cycloalkyl, are cyclopropyl, 2-methylcyclopropyl, 2,2-dimethylcyclopropyl, 2,3-diethylcyclopropyl, 2-butylcyclopropyl, cyclobutyl, 2-methylcyclobutyl, 3-propylcyclobutyl, 2,3,4-triethylcyclobutyl, cyclopentyl, 2,2-dimethylcyclopentyl, 2-pentylcyclopentyl, 3-tert-butylcyclopentyl, cyclohexyl, 4-tert-butylcyclohexyl, 3-isopropylcyclohexyl, 2,2-dimethylcyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, and cyclodecyl.
Examples of aralkyl of 7 to 12 carbon atoms, inclusive, are benzyl, 2-phenethyl, 1-phenylethyl, 2-phenylpropyl, 4-phenylbutyl, 3-phenylbutyl, 2-(1-naphthylethyl), and 1-(2-naphthylmethyl).
Examples of phenyl substituted by one to 3 chloro or alkyl of one to 4 carbon atoms, inclusive, are p-chlorophenyl, m-chlorophenyl, 2,4-dichlorophenyl, 2,4,6-trichlorophenyl, p-tolyl, m-tolyl, o-tolyl, p-ethylphenyl, p-tertbutylphenyl, 2,5-dimethylphenyl, 4-chloro-2-methylphenyl, and 2,4-dichloro-3-methylphenyl.
Examples of ##STR63## wherein T is alkyl of one to 3 carbon atoms, inclusive, fluoro, chloro, trifluoromethyl, or alkoxy of one to 3 carbon atoms, inclusive; and s is zero, one, 2, or 3, with the proviso that not more than two T's are other than alkyl, are phenyl, (o-, m-, or p-)tolyl, (o-, m-, or p-)-ethylphenyl, 2-ethyl-p-tolyl, 4-ethyl-o-tolyl, 5ethyl-m-tolyl, (o-, m-, or p-)propylphenyl, 2-propyl-(o-, m-, or p-)tolyl, 4-isopropyl-2,6-xylyl, 3-propyl-4-ethylphenyl, (2,3,4-, 2,3,5-, 2,3,6-, or 2,4,5-)trimethylphenyl, (o-, m-, or p-)fluorophenyl, 2-fluoro-(o-, m-, or p-)tolyl, 4-fluoro-2,5-xylyl, (2,4-, 2,5-, 2,6-, 3,4-, or 3,5-)difluorophenyl, (o-, m-, or p-)-chlorophenyl, 2-chloro-p-tolyl, (3-, 4-, 5-, or 6-)chloro-o-tolyl, 4chloro-2-propylphenyl, 2-isopropyl-4-chlorophenyl, 4-chloro-3,5-xylyl, (2,3- 2,4-,, 2,5-, 2,6-, 3,4-, or 3,5-)dichlorophenyl, 4-chloro-3-fluorophenyl, (3- or 4-)chloro-2-fluorophenyl, o-, m-, or p-trifluoromethylphenyl, (o-, m-, or p-)methoxyphenyl, (o-, m-, or p-)ethoxyphenyl, (4- or 5-)chloro-2-methoxyphenyl, and 2,4-dichloro(5- or 6-)methylphenyl.
The novel prostaglandin analogs of this invention correspond to the prostaglandins described above, in that the novel prostaglandin analogs exhibit prostaglandin-like activity.
Specifically the 8β,12α-PGE-, 11-deoxy-8β,12α-PGE-, PGE-, and 11-deoxy-PGE-type compounds of this invention correspond to the PGE compounds described above, in that these novel PGE- and 11-deoxy-PGE-type compounds are useful for each of the above-described purposes for which the PGE compounds are used, and are used in the same manner as the PGE compounds, as described above.
The 8β,12α-PGF.sub.α-, 11-deoxy-8β,12α-PGF.sub.α-, PGF.sub.α- and 11-deoxy-PGF.sub.α-type compounds of this invention correspond to the PGF.sub.α compounds described above, in that these novel PGF.sub.α- and 11-deoxy-PGF.sub.α-type compounds are useful for each of the above-described purposes for which the PGF.sub.α compounds are used, and are used in the same manner as the PGF.sub.α compounds, as described above.
The 8β,12α-PGF.sub.β-, 11-deoxy-8β,12α-PGF.sub.β-, PGF.sub.β-and 11-deoxy-PGF.sub.β-type compounds of this invention correspond to the PGF.sub.β compounds described above, in that these novel PGF.sub.β-and 11-deoxy-PGF.sub.β-type compounds are useful for each of the above-described purposes for which the PGF.sub.β compounds are used, and are used in the same manner as the PGF.sub.β compounds, as described above.
The 8β,12α-PGA- and PGA-type compounds of this invention correspond to the PGA compounds described above, in that these novel PGA-type compounds are useful for each of the above described purposes for which the PGA compounds are used, and are used in the same manner as the PGA compounds, as described above.
The PGB-type compounds of this invention correspond to the PGB compounds described above, in that these PGB-type compounds are useful for each of the above described purposes for which the PGB compounds are used, and are used in the same manner as the PGB compounds, as described above.
The prostaglandins described above, are all potent in causing multiple biological responses even at low doses. Moreover, for many applications, these prostaglandins have an inconveniently short duration of biological activity. In striking contrast, the novel prostaglandin analogs of this invention are substantially more selective with regard to potency in causing prostaglandin-like biological responses, and have a substantially longer duration of biological activity. Accordingly, each of these novel prostaglandin analogs is surprisingly and unexpectedly more useful than one of the corresponding prostaglandins described above for at least one of the pharmacological purposes indicated above for the latter, because it has a different and narrower spectrum of biological potency than the known prostaglandin, and therefore is more specific in its activity and causes smaller and fewer undesired side effects than when the prostaglandin is used for the same purpose. Moreover, because of its prolonged activity, fewer and smaller doses of the novel prostaglandin analog are frequently effective in attaining the desired result.
Another advantage of the novel prostaglandin analogs of this invention, especially the preferred PG analogs defined hereinbelow, compared with the corresponding prostaglandins, is that these novel PG analogs are administered effectively orally, sublingually, intravaginally, buccally, or rectally in those cases wherein the corresponding prostaglandin is effective only by the intravenous, intramuscular, or subcutaneous injection or infusion methods of administration indicated above as uses of these prostaglandins. These alternate routes of administration are advantageous because they facilitate maintaining uniform levels of these compounds in the body with fewer, shorter, or smaller doses, and make possible self-administration by the patient.
Accordingly, the novel prostaglandin analogs of this invention are administered in various ways for various purposes: e.g., intravenously, intramuscularly, subcutaneously, orally, intravaginally, rectally, buccally, sublingually, topically, and in the form of sterile implants for prolonged action. For intravenous injection or infusion, sterile aqueous isotonic solutions are preferred. For intravenous injection or infusion, sterile aqueous isotonic solutions are preferred. For that purpose, it is preferred because of increased water solubility that R 1 in the novel compounds of this invention be hydrogen or a pharmacologically acceptable cation. For subcutaneous or intramuscular injection, sterile solutions or suspensions of the acid, salt, or ester form in aqueous or non-aqueous media are used. Tablets, capsules, and liquid preparations such as syrups, elixirs, and simple solutions, with the usual pharmaceutical carriers are used for oral sublingual administration. For rectal or vaginal administration, suppositories prepared as known in the art are used. For tissue implants, a sterile tablet or silicone rubber capsule or other object containing or impregnated with the substance is used.
The chemical structure of the novel 11-deoxy-PGE-type compounds of this invention renders them less sensitive to dehydration and rearrangement than the corresponding prostaglandins, and these compounds accordingly exhibit a surprising and unexpected stability and duration of shelf life.
The novel PG analogs of this invention are used for the purposes described above in the free acid form, in ester form, in pharmacologically acceptable salt form. When the ester form is used, the ester is any of those within the above definition of R 1 . However, it is preferred that the ester be alkyl of one to 12 carbon atoms, inclusive. Of the alkyl esters, methyl and ethyl are especially preferred for optimum absorption of the compound by the body or experimental animal system; and straight-chain octyl, nonyl, decyl, undecyl, and dodecyl are especially preferred for prolonged activity in the body or experimental animal.
Pharmacologically acceptable salts of the novel prostaglandin analogs of this invention compounds useful for the purposes described above are those with pharmacologically acceptable metal cations, ammonium, amine cations, or quaternary ammonium cations.
Especially preferred metal cations are those derived from the alkali metals, e.g., lithium, sodium, and potassium, and from the alkaline earth metals, e.g., magnesium and calcium, although cationic forms of other metals, e.g., aluminum, zinc, and iron are within the scope of this invention.
Pharmacologically acceptable amine cations are those derived from primary, secondary, or tertiary amines. Examples of suitable amines are methylamine, dimethylamine, trimethylamine, ethylamine, dibutylamine, triisopropylamine, N-methylhexylamine, decylamine, dodecylamine, allylamine, crotylamine, cyclopentylamine, dicyclohexylamine, benzylamine, dibenzylamine, α-phenylethylamine, β-phenylethylamine, ethylenediamine, diethylenetriamine, and the like aliphatic, cycloaliphatic, araaliphatic amines containing up to and including about 18 carbon atoms, as well as heterocyclic amines, e.g., piperidine, morpholine, pyrrolidine, piperazine, and lower-alkyl derivatives thereof, e.g., 1-methylpiperidine, 4-ethylmorpholine, 1-isopropyl-pyrrolidine, 2-methylpyrrolidine, 1,4-dimethylpiperazine, 2-methylpiperidine, and the like, as well as amines containing water-solubilizing or hydrophilic groups, e.g., mono-, di-, and triethanolamine, ethyldiethanolamine, N-butylethanolamine, 2-amino-1-butanol, 2-amino-2-ethyl-1,3-butylethanolamine, 2-amino-1-butanol, 2-amino-2-ethyl-1,3-propanediol, 2-amino-2-methyl-1-propanol, tris(hydroxymethyl)aminomethane, N-phenylethanolamine, N-(p-tert-amylphenyl)-diethanolamine, galactamine, N-methylgycamine, N-methylglucosamine, ephedrine, phenylephrine, epinephrine, procaine, and the like. Further useful amine salts are the basic amino acid salts, e.g., lysine and arginine.
Examples of suitable pharmacologically acceptable quaternary ammonium cations are tetramethylammonium, tetraethylammonium, benzyltrimethylammonium, phenyltriethylammonium, and the like.
The novel PG analogs of this invention are used for the purposes described above in free hydroxy form or also in the form wherein the hydroxy moieties are transformed to lower alkanoate moieties such as acetoxy, propionyloxy, butyryloxy, valeryloxy, hexanoyloxy, heptanolyloxy, octanoyloxy, and branched chain alkanoyloxy isomers of those moieties. Especially preferred among these alkanoates for the above describe purposes are the acetoxy compounds. These free hydroxy and alkanoyloxy compounds are used as free acids, as esters, and in salt form all as described above.
To obtain the optimum combination of biological response specificity, potency, and duration of activity, certain compounds within the scope of this invention are preferred.
It is preferred that the carboxy-terminated side chain contain either 7 or 9 (or carbon and oxygen) atoms, especially preferred that it contain 7, i.e., the natural chain length of the prostaglandins. Further when the other side chain contains --(CH 2 ) m --CH 3 , it is preferred that m be 3. For those compounds wherein R 7 is ##STR64## or ##STR65## it is preferred that s be zero or one and T be chloro, fluoro, or trifluoromethyl.
For those compounds wherein at least one of R 3 and R 4 is methyl or fluoro, it is preferred that R 5 and R 6 both by hydrogen. For those compounds wherein at least one of R 5 and R 6 is methyl, it is preferred that R 3 and R 4 both be hydrogen. For those compounds wherein R 7 is ##STR66## or ##STR67## it is preferred that R 3 , R 4 , R 5 , and R 6 all be hydrogen.
For those compounds wherein an oxa is substituted for a methylene (i.e., --O-- for --CH 2 --), it is preferred that such substitution occur at C-5.
It is further preferred that the 15-hydroxy or 15-methoxy not of the 15-epi configuration, i.e., that the hydroxy be in the alpha configuration when the formulas of the novel 13,14-didehydro-PG analogs are as drawn herein.
Especially preferred are those compounds which satisfy two or more of the above preferences. Further, the above preferences are expressly intended to describe the preferred compounds within the scope of any generic formula of novel prostaglandin analogs disclosed herein. Thus, for example the above preferences describe preferred compounds within the scope of each formula of a prostaglandin analog provided in the Tables hereinafter.
In another aspect of the interpretation of the preferences herein, the various prostaglandin cyclopentane ring structures as employed herein are each representative of a particular "parent structure" which is useful in naming and catagorizing the novel prostaglandin analogs disclosed herein. Further, where a formula depicts a genera of PG analogs disclosed herein evidencing a single cyclopentane ring structure, then each corresponding genus of PG analogs evidencing one of the remaining cyclopentane ring structures cited herein for novel prostaglandin analogs is intended to represent an equally preferred genus of compounds. Thus, for example, for each genus of PGF.sub.α -type products depicted by a formula herein, the corresponding genus of PGF.sub.β-, PGe-, and 11-deoxy-PGF.sub.α-type products are equally preferred embodiments of the invention as the genus of PGF.sub.α-type products.
Finally where subgeneric grouping of PG analogs of any cyclopentane ring structure are described herein, then the corresponding subgeneric groupings of PG analogs of each of the remaining cyclopentane ring structures are intended to represent equally preferred embodiments of the present invention.
The Charts herein describe methods whereby the novel prostaglandin analogs of this invention are prepared.
With respect to the Charts R 1 , Y 1 , R 7 , M 1 , L 1 , Z 1 , and g are as defined above; ##STR68## is as variously defined above M 5 is or a mixture of ##STR69## and ##STR70## M 6 is ##STR71## or a mixture of ##STR72## and ##STR73## wherein R 10 is a blocking group.
M 7 is ##STR74## or ##STR75## wherein R 31 is a blocking group as defined hereinbelow in the text accompanying Chart N.
M 9 is ##STR76## or ##STR77##
M 11 is a mixture of ##STR78## and ##STR79##
M 12 is ##STR80## or ##STR81##
M 18 is ##STR82##
M 19 is ##STR83## or ##STR84##
when R 6 is methyl, and ##STR85## or ##STR86## when R 6 is hydrogen, wherein R 39 is hydrogen or methyl, being the same as R 5 .
R 2 is hydrogen or fluoro. R 8 is hydrogen or hydroxy. R 16 is hydrogen or --OR.sub. 9, wherein R 9 is an acyl protecting group as defined below. R 18 is hydrogen or --OR 10 , wherein R 10 is as defined above. R 22 is methyl or ethyl. R 26 is hydrocarbyl, including alkyl, aralkyl, cycloalkyl, and the like. Examples of these hydrocarbyl groups include 2-methylbutyl, isopentyl, heptyl, octyl, nonyl, tridecyl, octadecyl, benzyl, phenethyl, p-methylphenethyl, 1-methyl-3-phenylpropyl, cyclohexyl, phenyl, and p-methylphenyl,
G 1 is alkyl of one to 4 carbon atoms, cycloalkyl of 3 to 10 carbon atoms, inclusive, aralkyl of 7 to 12 carbon atoms, phenyl, or phenyl substituted with one or 2 fluoro, chloro, or alkyl of one to 4 carbon atoms, with the proviso that in the --Si--(G 1 ) 3 moiety the various G 1 's are the same or different. R 38 is hydrogen or --O--Si--(G 1 ) 3 , wherein G 1 is as defined above.
R 9 is an acyl protecting group. Acyl protecting groups according to R 9 , include:
a. Benzoyl;
b. Benzoyl substituted with one to 5, inclusive, alkyl of one to 4 carbon atoms, inclusive, phenylalkyl of 7 to 12 carbon atoms, inclusive, or nitro, with the proviso that not more than 2 substituents are other than alkyl, and that the total number of carbon atoms in the substituents does not exceed 10 carbon atoms, with the further proviso that the substituents are the same or different;
c. Benzoyl substituted with alkoxycarbonyl of 2 to 5 carbon atoms, inclusive;
d. Naphthoyl;
e. Naphthoyl substituted with one to 9, inclusive, alkyl of one to 4 carbon atoms, inclusive, phenylalkyl of 7 to 10 atoms, inclusive, or nitro, with the proviso that not more than 2 substituents on either of the fused aromatic rings are other than alkyl and that the total number of carbon atoms in the substituents on either of the fused aromatic rings does not exceed 10 carbon atoms, with the further proviso that the various substituents are the same or different; or
f. Alkanoyl of 2 to 12 carbon atoms, inclusive.
In preparing these acyl derivatives of a hydroxycontaining compound herein, methods generally known in the art are employed. Thus, for example, an aromatic acid of the formula R 9 OH, wherein R 9 is as defined above (e.g., benzoic acid), is reacted with the hydroxy-containing compound in the presence of a dehydrating agent, e.g. sulfuric acid, zinc chloride, or phosphoryl chloride; or alternatively an anhydride of the aromatic acid of the formula (R 9 2 O (e.g., benzoic anhydride) is used.
Preferably, however, the process described in the above paragraph proceeds by use of the appropriate acyl halide, e.g., R 9 Hal, wherein Hal is chloro, bormo, or iodo. For example, benzoyl chloride is reacted with the hydroxycontaining compound in the presence of a hydrogen chloride scavenger, e.g. a tertiary amine such as pyridine, triethylamine or the like. The reaction is carried out under a variety of conditions, using procedures generally known in the art. Generally mild conditions are employed: 20°-60° C., contacting the reactants in a liquid medium (e.g., excess pyridine or an inert solvent such as benzene. toluene, or chloroform). The acylating agent is used either in stoichiometric amount or in substantial stoichiometric excess.
As examples of R 9 , the following compounds are available as acids (R 9 OH), anhydrides ( (R 9 ) 2 O ), or acyl chlorides (R 9 Cl): benzoyl; substituted benzoyl, e.g., 2-, 3-, or 4-)-methylbenzoyl, (2-, 3-, or 4-)ethyl benzoyl, (2-, 3-, or 4-)-isopropylbenzoyl, (2-, 3-, or 4-)tert-butylbenzoyl, 2,4-dimethylbenzoyl, 3,5-dimethylbenzoyl, 2-isopropyltoluyl, 2,4,6-trimethylbenzoyl, pentamethylbenzoyl, alphaphenyl-(2-, 3-, or 4 -)-toluyl, (2-, 3-,, or 4-)-phenethylbenzoyl, (2-, 3-, or 4-)-nitrobenzoyl, (2,4-, 2,5-, or 2,3-)-dinitrobenzoyl, 2,3-dimethyl-2-nitrobenzoyl, 4,5-dimethyl-2-nitrobenzoyl, 2-nitro-6-phenethylbenzoyl, 3-nitro-2-phenethylbenzoyl, 2-nitro-6-phenethylbenzoyl, 3-nitro-2-phenethylbenzoyl; mono esterified phthaloyl, isophthaloyl, or terephthaloyl; 1- or 2-naphthoyl; substituted naphthoyl, e.g., (2-, 3-, 4-, 5-, 6-, or 7-)-methyl-1-naphthoyl, (2- or 4-) ethyl-1-naphthoyl, 2-isopropyl-1-naphthoyl, 4,5-dimethyl-1-naphthoyl, 6-isopropyl-4-methyl-1-naphthoyl, 8-benzyl- 1-naphthoyl, (3-, 4-, 5-, or 8-)-nitro-1-naphthoyl, 4,5-dinitro-1-naphthoyl, (3-, 4-, 6-, 7-, or 8-)methyl-1- naphthoyl, 4-ethyl-2-naphthoyl, and (5- or 8-)nitro-2-naphthoyl; and acetyl.
There may be employed, therefore, benzoyl chloride, 4-nitrobenzoyl chloride, 3,5-dinitrobenzoyl chloride, or the like, i.e. R 9 Cl compounds corresponding to the above R 9 groups. If the acyl chloride is not available, it is prepared from the corresponding acid and phosphorus pentachloride as is known in the art. It is preferred that the R 9 OH, (R 9 ) 2 O, or R 9 Cl reactant does not have bulky hindering substituents, e.g. tert-butyl on both of the ring carbon atoms adjacent to the carbonyl attaching cite.
The acyl protecting groups, according to R 9 , are removed by decylation. Alkali metal carbonates are employed effectively at ambient temperature for this purpose. For example, potassium carbonate in methanol at about 25° C. is advantageously employed.
Those blocking groups within the scope of R 10 are any group which replaces a hydroxy hydrogen and is neither attacked nor as reactive to the reagents used in the transformations used herein as an hydroxy is and which is subsequently replaceable with hydrogen in the preparation of the prostaglandin-type compounds. Several blocking groups are known in the art, e.g. tetrahydropyranyl and substituted tetrahydropyranyl. See for reference E. J. Corey, Proceedings of the Robert A. Welch Foundation Conferences on Chemical Research, 12, Organic Synthesis, pgs. 51-79 (1969). Those blocking groups which have been found useful include
a. tetrahydropyranyl;
b. tetrahydrofuranyl; and
c. a group of the formula
--C(OR.sub.11)(R.sub.12)--CH(R.sub.13)(R.sub.14),
wherein R 11 is alkyl of one to 18 carbon atoms, inclusive, cycloalkyl of 3 to 10 carbon atoms, inclusive, aralkyl of 7 to 12 carbon atoms, inclusive, phenyl or phenyl substitued with one to 3 alkyl of one to 4 carbon atoms, inclusive, wherein R 12 and R 13 are alkyl of one to 4 carbon atoms, inclusive, phenyl, phenyl substituted with one, 2, or 3 alkyl of one to 4 carbon atoms, inclusive, or when R 12 and R 13 are taken together --(CH 2 ) a --or --(CH 2 ) b -- O--(CH 2 ) c , wherein a is 3, 4, or 5, or b is one, 2, or 3, and c is one, 2, or 3, with the proviso that b plus c is 2, 3, or 4, with the further proviso that R 12 and R 13 may be the same or different, and wherein R 14 is hydrogen or phenyl.
When the blocking group R 10 is tetrahydropyranyl, the tetrahydropyranyl ether derivative of any hydroxy moieties of the PG-type intermediates herein is obtained by reaction of the hydroxy-containing compound wi th 2,3-dihydropyran in an inert solvent, e.g. dichloromethane, in the presence of an acid condensing agent such as p-toluenesulfonic acid or pyridine hydrochloride. The dihydropyran is used in large stoichoimetric excess, preferably 4 to 10 times the stoichoimetric amount. The reaction is normally complete in less than an hour at 20 ° to 50° C.
When the blocking group is tetrahydrofuranyl, 2,3-dihydrofuran is used, as described in the preceding paragraph, in place of the 2,3-dihydropyran.
When the blocking group is of the formula
--C(OR.sub.11)(R.sub.12)--CH(R.sub.13)(R.sub.14),
wherein R 11 , R 12 , R 13 , and R 14 are as defined above, the appropriate reagent is a vinyl ether, e.g. isobutyl vinyl ether or any vinyl ether of the formula
C(OR.sub.11)(R.sub.12)=C(R.sub.13)(R.sub.14),
wherein R 11 , R 12 , R 13 , and R 14 are as defined above; or an unsaturated cyclic or heterocyclic compound, e.g. 1-cyclohexen-1-yl methyl ether, or 5,6-dihydro-4-methoxy-2H-pyran. See C. B. Reese, et al., Journal of the Chemical Society 89, 3366 (1967). The reaction conditions for such vinyl ethers and unsaturated compounds are similar to those for dihydropyran above.
The blocking groups according to R 10 are removed by mild acidic hydrolysis. For example, by reaction with (1) hydrochloric acid in methanol; (2) a mixture of acetic acid, water, and tetrahydrofuran; or (3) aqueous citric acid or aqueous phosphoric acid in tetrahydrofuran, at temperatures below 55° C., hydrolysis of the blocking groups is achieved.
R 53 is hydrogen or alkyl of one to 4 carbon atoms, inclusive. R 55 and R 56 are alkyl of one to 4 carbon atoms, inclusive, being the same or different, or when taken together represent a group of the formula: ##STR87## wherein R 57 , R 58 , R 59 , R 60 , R 61 , and R 62 are hydrogen, alkyl of one to 4 carbon atoms, inclusive, or phenyl, being the same or different, with the proviso that not more than one of R 57 , R 58 , R 59 , R 60 , R 61 , and R 62 is phenyl and that the total number of carbon atoms in R 57 , R 58 , R 59 , R60, R 61 , and R 62 is from 2 to 10, inclusive, and h is zero or one.
R 63 is carboxyacyl of the formula ##STR88## wherein R 64 is hydrogen, alkyl of one to 19 carbon atoms, inclusive, or aralkyl of 7 to 12 carbon atoms, inclusive, whherein the above alkyl or aralkyl are substituted with zero to 3 fluoro, chloro, bromo, or iodo. R 66 is hydrogen or a blocking group, according to R 65 . Blocking groups according to R 65 useful for the purposes of this invention include all blocking groups according to R 10 , as enumerated herein, and additionally --Si(G 1 ) 3 , wherein G 1 is alkyl of one to 4 carbon atoms, inclusive, cycloalkyl of 3 to 10 carbon atoms, inclusive, aralkyl of 7 to 12 carbon atoms, inclusive, phenyl, or phenyl substituted with one or 2 fluoro, chloro, or alkyl of one to 4 carbon atoms, inclusive. In the use of these silyl blocking groups, according to R 65 , methods known in the art for the preparation of the necessary reagents and appropriate reaction conditions for replacing hydroxy hydrogens with these silyl blocking groups and subsequently hydrolyzing these silyl blocking groups, are employed.
R 68 is hydrogen, carboxyacyl according to R 63 , or an acyl protecting group according to R 9 . R 69 is hydrogen or alkyl of one to 4 carbon atoms, inclusive, R 70 is hydrogen, alkyl of one to 4 carbon atoms, inclusive, or silyl of the formula -Si(G 1 ) 3 , wherein G 1 is as defined above. R 66 is hydrogen or optionally R 65 , a blocking group.
Y 2 is trans-CH=Cl(Hal)-- , wherein Hal is chloro, bromo, or iodo. Y 3 is trans--CH=CH. Z 2 is cis--CH=CH--CH 2 --(CH 2 ) g --C(R 2 ) 2 --, cis--CH 2 --CH=CH--(CH 2 ) g --CH 2 , --(CH 2 ) 3 --(CH 2 ) g --C(R 2 ) 2 --, --CH 2 --O--CH 2 --(CH 2 ) g --CH 2 --, --(CH 2 ) 2 --O--(CH 2 ) g --CH 2 --, or --(CH 2 ) 3 --O--(CH 2 ) g --, wherein R 2 and g are as defined above. Z 3 is oxa or methylene, e.g., --O-- or --CH 2 --, respectively.
as respect to Chart A the formula XXI compound is known in the art. This compound is available in either of two enantiomeric forms or a a mixture thereof. The formula XXI compound in racemic form may be transformed into corresponding optically active compound by methods known in the art.
The formula XXII compound is prepared from the formula XXI compound by a Wittig alkylation when R 7 is not 1-butenyl. Reagents known in the art or prepared by methods known in the art are employed. The transenone lactone is obtained stereospecifically. See for reference D. H. Wadsworth, et al., Journal of Organic Chemistry 30, 680 (1965).
In the preparation of the formula XXII compound, certain phosphonates are employed in the Wittig reaction. These phosphonates are of the general formula ##STR89## wherein L 1 and R 7 are as defined above (but R 7 is not 1-butenyl) and R 15 is alkyl of one to 8 carbon atoms, inclusive.
Phosphonates of the above general formula are prepared by methods known in the art. See Wadsworth, et al. as cited above.
Conveniently the appropriate aliphatic acid ester is condensed with the anion of dimethyl methylphosphonate as produced using n-butyllithium. For this purpose, acids of the general formula ##STR90## are employed in the form of their lower alkyl esters, preferably methyl or ethyl. The methyl esters for example are readily obtained by reaction of the corresponding acids with diazomethane.
For example, when R 7 is ##STR91## wherein T and s are as defined above, and R 3 and R 4 of the L 1 moiety are both hydrogen, the corresponding phenoxy or substituted phenoxy acetic acids are known in the art or readily available in the art. Those known in the art include those wherein the R 7 moiety is: phenoxy, (o-, m-, or p-)tolyloxy-, (o-, m-, or p-)ethylphenoxy-, 4-ethyl-o-tolyloxy-, (o-, m-, or p-)propylphenoxy-, (o-, m-, or p-)-t-butylphenoxy-, (o-, m-, or p-)fluorophenoxy-, 4-fluoro-2,5-xylyloxy-, (o-, m-, or p-)chlorophenoxy-, (2,3-, 2,4 2,5-, 2,6-, 3,4-, or 3,5-)dichlorophenoxy-, (o-, m-, or p-)trifluoromethylphenoxy-, or (o-, m-, or p-)methoxyphenoxy-.
Further, many 2-phenoxy- or substituted phenoxy propionic acids are readily available, and are accordingly useful for the preparation of the acids of the above formula wherein one and only one of R 3 and R 4 of the L 1 moiety is methyl and R 7 is phenoxy or substituted phenoxy. These 2-phenoxy or 2-substituted phenoxy propionic acids include those wherein the R 7 moiety is p-fluorophenoxy-, (o-, m-, or p-)chlorophenoxy-, (2,3-, 2,4-, 2,5-, 2,6-, 3,4-, or 3,5-)dichorophenoxy-, (4-or 6-chloro-o-tolyloxy-, phenoxy-, (o-, m-, or p-)tolyloxy, 3,5-xylyloxy-, or m-trifluoromethylphenoxy-.
Finally there are available many 2-methyl- 2-phenoxyor (2-substituted)phenoxypropionic acids, which are useful in the preparation of the above acids wherein R 3 and R 4 of the L 1 moiety are both methyl and R 7 is phenoxy or substituted phenoxy. These 2-methyl-2-phenoxy-, or (2-substituted)phenoxypropionic acids include those wherein R 7 is: phenoxy-, (o-, m-, or p-)chlorophenoxy-, (2,3-, 2,4-, 2,5-, 2,6-, 3,4-, or 3,5-)dichlorophenoxy-.
Other phenoxy substituted acids are readily available by methods known in the art, for example, by Williamson synthesis of ethers using an α-halo aliphatic acid or ester with sodium phenoxide or a substituted sodium phenoxide. Thus, the (T) s substituted sodium phenoxide is reacted with, for example, the α-chloro aliphatic acid, or the alkyl ester derivative thereof, with heating to yield the acid of the above general formula, which is recovered from the reaction mixture by conventional purification techniques.
There are further available phenyl substituted acids of the above formula wherein R 7 is benzyl or substituted benzyl.
For example, when R 3 and R 4 of the L 1 moiety are both hydrogen there are available the following phenyl or substituted phenyl propionic acids: (o-, m-, or p-)-chlorophenyl-,p-fluorophenyl-, m-trifluoromethylphenyl, (o-, m-, or p-)methylphenyl-, (o-, m-, or p-)methoxyphenyl-(2,4-, 2,5-, or 3,4-)dichlorophenyl, (2,3-, 2,4-, 2,5-, 2,6-, or 3,4-)dimethylphenyl-, or (2,3-, 2,4-, 2,5-, 2,6-, 3,4-, or 3,5 -)dimethoxyphenyl-.
When one and only one of R 3 and R 4 of the L 1 moiety is methyl there are available, for example, the following 2-methyl-3-phenyl or substituted phenyl propionic acids: phenyl, o-chlorophenyl-, (o-, or p-)methylphenyl-, (o-, m-, or p-)methoxyphenyl-, (2,4- or 3,4-)difluorophenyl-, 2,3-dimethylphenyl-, and (2,3-, 3,4-, or 4,5-)dimethoxyphenyl-.
When both R 3 and R 4 are methyl there are available, for example, the following 2,2-dimethyl-3-phenyl or substituted phenyl propionic acids: phenyl- and p-methylphenyl.
When one and only one of R 3 and R 4 is fluoro, there is available, for example, 2-fluoro-3-phenyl propionic acid.
Phenyl substituted acids (as above wherein R 7 is benzyl) are available by methods known in the art, for example, by reacting a mixture of the appropriate methyl- or fluoro-substituted acetic acid, a secondary amine (e.g., diisopropylamine), n-butyllithium, and an organic diluent (e.g., tetrahydrofuran) with the appropriately substituted benzyl chloride. Thus, the above acid is obtained by the following reaction: ##STR92## The above reaction proceeds smoothly, ordinarily at 0° C. The product acid is recovered using conventional methods.
For the acids of the above formula wherein R 7 is n-alkyl, many such acids are readily available.
For example, when R 3 and R 4 of the L 1 moiety are both hydrogen there are available butyric, pentanoic, hexanoic, heptanoic, and octanoic acids.
For example, when one and only one of R 3 and R 4 of the L 1 moiety is methyl, there are available the following 2-methyl alkanoic acids: butyric, pentanoic, hexanoic, heptanoic, and octanoic.
For example, when one of R 3 and R 4 of the L 1 moiety is fluoro there are available the following 2-fluoro alkanoic acids: butyric, pentanoic, hexanoic, heptanoic, and octanoic.
The acids of the above general formula wherein R 7 is alkyl and R 3 and R 4 of the L 1 moiety are fluoro are conveniently prepared from the corresponding 2-oxoalkanoic acids, i.e. butyric, pentanoic, hexanoic, heptanoic, and octanoic. The transformation of these 2-oxo-alkanoic acids to the corresponding 2,2-difluoro alkanoic acids, proceeds by methods known in the art, using known ketonic fluorinating reagents. For example, MoF 6 .sup.. BF 3 is advantageously employed in the fluorination.
When R 7 is 1-butenyl, the formula XXII compound is prepared from the formula XXI compound by transformation of the formula XXI 2β-carboxaldehyde to a corresponding 2β-(2-formyl-trans-1-ethenyl) compound followed by a Grignard reaction employing the reagent prepared from ##STR93## Thereupon the (3RS)-3-hydroxy compound corresponding to formula XXII is prepared, which is oxidized to the formula XXII compound with the Collins reagent. Accordingly, following the procedure of Japanese Application Number 0018-459, 3α-benzoyloxy-5α-hydroxy-2β-carboxaldehyde-1α-cyclopentaneacetic acid y-lactone is transformed to benzoyloxy-5α-hydroxy-2β-(2-formyl-trans-1-ethenyl)-1α-cyclopentane acid γ-lactone. This product is then reacted with the Grignard reagent described above and oxidized as above.
The formula XXIII compound is prepared from the formula XXII compound by dihalogenation, followed by dehydrohalogenation. The halogenation proceeds by methods known in the art, conveniently by reaction of the formula XXII compound with a reagent such as N-halosuccinimide. The reaction proceeds slowly to completion, ordinarily within three to ten days. Alternatively the molecular form of the halide (Hal) 2 in a diluent (e.g., carbon tetrachloride or a mixture of acetic acid and sodium acetate) is employed in this dihalogenation. Thereafter dehydrohalogenation proceeds by addition of an organic base, preferably amine base, to the halide. For example pyridine, or a diazobicycloalkene, is an especially useful amine base, although non-amine bases such as methanolic sodium acetate are likewise employed.
Optionally the formula XXIII compound is prepared directly from the formula XXI compound using a Wittig reagent derived from a 1-halophosphonate corresponding to the phosphonate described above for the preparation of the formula XXII compound. These phosphonates are known in the art or are readily prepared by methods known in the art. For example, a phosphonate as described above is transformed to the corresponding 1-halophosphonate by dripping the molecular halogen into a solution of the phosphonate and a strong organic base, e.g. sodium methoxide. In any event, the 14-chloro intermediates are preferred formula XXIII products, in that they lead to PG intermediates which are more easily dehydrohalogenated at C-13 and C-14 according to the procedure of Chart R.
The 1-halophosphonate as prepared above is then reacted with the formula XXI compound in a manner described for the preparation of the formula XXII compound from the formula XXI compound to prepare the formula XXIII compound.
In each of the above described methods for the preparation of the formula XXIII compound the desired formula XXIII product is often contaminated with its corresponding cis isomer. In performing the below steps it is particularly desirable to obtain pure formula XXIII product in order to avoid creation of complicated mixtures of steroisomers. Accordingly, the formula XXIII compound is subjected to conventional separation techniques (e.g. silica gel chromatography) to obtain pure product.
The formula XXIV compound is prepared from the formula XXIII 3-oxo bicyclic lactone by transformation of the 3-oxo-moiety to the M 5 moiety.
The above 3-oxo bicyclic lactone is transformed to the corresponding 3α or 3β-hydroxy bicyclic lactone, wherein M 5 is ##STR94## or ##STR95## by reduction of the 3-oxo moiety, followed by separation of the 3α- and 3β-hydroxy epimers. For this reduction the known ketonic carbonyl reducing agents which do not reduce ester or acid groups or carbon-carbon double bonds (when such reduction is undesirable) are employed. Examples of these agents are the metal borohydrides, especially sodium, potassium, and zinc borohydrides, lithium(tri-tert-butoxy)-aluminum hydride, metal trialkyl borohydrides, e.g. sodium trimethoxy borohydride, lithium borohydride, and the like. In those cases in which carbon-carbon double bond reduction need not be avoided, the boranes, e.g. disiamylborane (bis-3-methyl-2-butyl borane) are alternatively employed.
For the production of C-15 epimerically pure prostaglandins, the 15-epi compound is separated from the mixture by methods known in the art. For example, silica gel chromatography is advantageously employed.
For the transformation of the 3-oxo bicyclic lactone to the corresponding 3-methoxy bicyclic lactoe, the 3-hydroxy moiety of the 3-hydroxy bicyclic lactone prepared above is alkylated, employing methods known in the art.
The alkylation described in the above paragraph proceeds, for example, by reaction of the 3-hydroxy bicyclic lactone with diazomethane, preferably in the presence of a Lewis acid (e.g., boron trifluoride etherate, aluminum chloride, or fluoboric acid). See for reference Fieser, et al., "Reagents for Organic Synthesis," John Wiley and Sons, New York, N. Y., (1967), especially page 191. The reaction is carried out by mixing a solution of the diazomethane in a suitable inert diluent, preferably diethyl ether, with the 3-hydroxy bicyclic lactone prepared above. This reaction proceeds at about 25° C.
An alternate method for the alkylation of the 3-hydroxy compound is by reaction with methanol in the presence of boron trifluoride etherate. Thus, the methanol and boron trifluoride etherate are reacted with the 3-hydroxy compound at 25° C., the reaction being monitored conveniently by thin layer chromatography (TLC).
The 3-oxo bicyclic lactone is transformed into the corresponding (3RS)-3-methyl bicyclic lactone wherein M 5 is a mixture of ##STR96## and ##STR97## by reaction of the 3-oxo bicyclic lactone with a Grignard reagent, CH 3 MgHal, wherein Hal is chloro, bromo, or iodo. The Grignard complex is thereafter hydrolyzed, for example, using saturated aqueous ammonium chloride as is known in the art. An alternate method for transforming the 3-oxo compound to a 3(RS)-3-methyl compound is by reaction of the 3-oxo bicyclic lactone with trimethylaluminum.
The preferred method for separation of these (3RS)-3-methyl epimers is by separation of the corresponding C-15 epimers of the PG-type, methyl esters using silica gel chromatography or high pressure liquid chromatography (HPLC). The formula XXV compound is prepared from the formula XXIV compound by deacylation, as described above. The formula XXVI compound is then prepared from the formula XXV compound by replacing any free hydroxy moieties with blocking groups according to R 10 by the procedure described above. The formula XXVII compound is then prepared from the formula XXVI compound by reduction of the formula XXVI lactone to a lactol. Methods known in the art are employed. For example, diisobutylaluminum hydride is employed at -60° to -70° C.
Chart B provides a method whereby the formula XXXI lactol, prepared according to Chart A, is transformed into a corresponding formula XXXV 3-oxa-14-halo-PGF 1 .sub.α -type compound.
The formula XXXII compound is obtained from the formula XXXI lactol by the Wittig reaction, with an (alkoxymethylene)triphenyl phosphorane, R 22 OOC-CH=P(C 6 H 5 ) 3 , wherein R 22 is as defined above. The reaction is conveniently carried out at 25° C. using methods and reactants known in the art.
The formula XXXIII compound is then obtained by reduction of the ethylenic group in the carboxyl-containing side chain. For this purpose a reducing agent is used which does not reduce the Y group, for example hydrogen in the presence of a catalyst such as tris(triphenylphosphine)rhodium (1) chloride. Mild conditions are sufficient such as a pressure of 1-3 atmospheres and temperatures of 0° to 40° C.
The formula XXXIV alcohol is obtained from the formula XXXIII compound by reduction, for example with lithium aluminum hydride or lithium trimethoxy aluminum hydride. A solvent such as diethyl ether or tetrahydrofuran is conveniently used.
The formula XXXV compound is obtained by a Williamson synthesis, condensing the formula XXXIV alcohol with a haloalkanoate, Hal--(CH 2 ) g --COOR 1 , wherein Hal is chloro, bromo, or iodo and g and R 1 as above defined, in the presence of a base. For the base, there is used, for example, n-butyllithium, phenyllithium, triphenylmethyllithium, sodium hydride, or potassium t-butoxide. It is preferred that only one molecular equivalent of the base be used. The alkanoate is employed in about 100% stoichoimetric excess. Instead of a haloalkanoic acid ester, a salt, for example lithium chloroacetate is useful. After the condensation, the salt is transformed to the XXXV compound by methods known in the art. The condensation is conveniently run in a solvent such as dimethyl formamide, tetrahydrofuran, dimethyl sulfoxide, or hexamethylphosphoramide.
With respect to Chart C a method is provided whereby the formula XLI lactol is transformed into the corresponding formula XLIII 5-oxa-14-halo-PGF 1 .sub.α-type compound. The formula XLII alcohol is obtained upon reduction of the formula XLI lactol, for example, with aqueous methanolic or ethanolic sodium borohydride. Alternatively, and preferably, the formula XLII compound is obtained by a one step reduction of the formula XXVI lactone, for example, with lithium aluminum hydride or diisobutyl aluminum hydride at a temperature ranging from 0° to 35° C. For preparing the formula XLIII compound a Williamson synthesis is employed. For example, the formula XLII compound is condensed with a haloalkanoate within the scope of
Hal--(CH.sub.2).sub.g --CH.sub.2 --COOR.sub.1,
wherein Hal is chloro, bromo, or iodo and g is as defined above. Normally the reaction is done in the presence of a base such as n-butyllithium, phenyllithium, trimethyl-lithium, sodium hydride, or potassium t-butoxide.
Alternatively and preferably, an ortho-4-bromo-alkanoate, is employed. Such reagents are available or are prepared by methods known in the art, for example, from the appropriate halonitrileby way of the corresponding imino ester hydrohalide as illustrated hereinafter.
The condenstation is conveniently run in a solvent, such as tetrahydrofuran or dimethyl sulfoxide or especially if an organolithium compound is employed, preferably in dimethylformamide or hexamethylphosphoramide. The reaction proceeds smoothly at -20 or 50° C., but is preferably performed at ambient temperature. Following the condensation the formula XLIII compound is obtained by methods known in the art, for example, by hydrolysis in cold dilute mineral acid.
Chart D provides a methods whereby the formula LI compound is transformed into the corresponding formula LVIII 4-oxa-14-halo-PGF 1 α -type compound or formula LIX cis-4,5-didehydro-14-halo-PGF 1 .sub.α -type compound.
The formula LI compound undergoes condensation to form the formula LII enol. For this purpose a hydrocarbyloxy, and preferably an alkoxymethylenetriphenylphosphorane is useful. See for reference, Levine, Journal of the American Chemical Society 80, 6150 (1958). The reagent is conveniently prepared from a corresponding quaternary phosphonium halide in a base, e.g. butyllithium or phenyllithium, or low temperature, e.g. preferably below -10° C. The formula LI lactol is mixed with the above reagent and the condensation proceeds smoothly within the temperature range of -30° C.-+30° C. At higher temperatures the reagent is unstable, whereas at low temperatures the rate of condensation is undesirably slow. Examples of alkoxymethylenetriphenylphosphoranes preferred for the above purposes are methoxy-, ethoxy-, propoxy-, isopropoxy-, butoxy-, isobutoxy-, s-butoxy-, and t-butoxymethylenetriphenylphosphorane. Various hydrocarbyloxymethylenetriphenylphosphoranes which are optionally substituted for the alkoxymethylenetriphenylphoranes and are accordingly useful for preparing the formula LII intermediates wherein R 26 is hydrocarbyl, include alkoxy-, aralkoxy-, cycloalkoxy-, and aryloxymethylenetriphenylphosphoranes. Examples of these hydrocarbyloxytriphenylphosphoranes are 2-methyl butyloxy-, isopentyloxy-, heptyloxy-, octyloxy-, nonyloxy-, tridecyloxy-, octadecyloxy-, benzyloxy-, phenethyloxy-, p-methylphenethyloxy-, 1-methyl-3-phenylpropyloxy-, cyclohexyloxy-, phenoxy-, and p-methylphenoxy-, phenoxymethylenetriphenylphosphorane. See for reference, Organic Reactions, Vol. 14, pg. 346-348, John Wiley and Sons, New York, New York, (1965). The formula LII enol intermediates are then hydrolyzed to the formula LIII lactols. This hydrolysis is done under acidic conditions for example with perchloric acid or acetic acid. Tetrahydrofuran is a suitable diluent for this reaction mixture. Reaction temperatures of from 10° to 100° C. are employed. The length of time required for hydrolysis is determined in part by the hydrolysis temperature and using acetic acid-watertetrahydrofuran at about 60° C. several hr. are sufficient to accomplish the hydrolysis.
The formula LIV compound is then prepared from the formula LIII compound by oxidation of the formula LIII lactol to a lactone. This transformation is carried out, using for example, silver oxide as an oxidizing reagent, followed by treatment with pyridine hydrochloride.
The formula LIV lactone may then be converted to the formula LV ether by transformation of any free hydroxy moieties to blocking groups, according to R 10 , following the procedures herein described for these transformations.
Thereafter the formula LVI compound is prepared from the formula LV compound by reduction of the formula LV lactone to a lactol. For example, diisobutylaluminum hydride is employed as is described above for the reduction of lactones to lactols. The formula LVI lactols so prepared are then used alternatively for the preparation of the formula LVIII or LIX compound.
In the preparation of the formula LVIII compound, the formula LVI lactol is first transformed into the formula LVII compound by reduction of the formula LVI lactol. The formula LVII compound is then transformed into the corresponding formula LVIII compound by a Williamson synthesis. Methods and corresponding reagents employed in the transformation of the formula LVI compound to the formula LVII and thereafter the transformation of the formula LVII compound to the formula LVIII compound are analogous to methods described hereinabove for the transformation of the formula XCI compound to the formula XCII compound and thereafter the transformation of the formula XCII compound to the formula XCIII compound.
Accordingly, the formula LVIII 4-oxa-PGF 1 .sub.α -type compound is prepared.
The formula LIX compound is prepared from the formula LVI compound by a Wittig alkylation, using the appropriate (ω-carboxyalkyl)triphenylphosphonium bromide, HOOC-CH 2 -(CH 2 ) h -CH 2 -P-(C 6 H 5 ) 3 , wherein h is as defined above. The reaction proceeds as is generally known in the art, by first mixing the appropriate (ω-carboxyalkyl)triphenylphosphonium bromide with sodio dimethyl sulfinylcarbanide, at ambient temperature, and adding the formula LVI lactol to this mixture. Thereafter the carboxy hydrogen of the compound so formed is transformed to an R 1 moiety by the methods and procedures hereinbelow described. Accordingly, there is prepared the formula LIX cis-4,5-didehydro-PGF 1 .sub.α-type compound.
Chart E provides a method whereby the formula LXI compound is transformed to the corresponding formula LXII 14-halo-PGF 2 α- or 11-deoxy-14-halo-PGF 2 .sub.α-type compound or formula LXII 14-halo-PGF 1 .sub.α- or 11-deoxy-14-halo-PGF 1 .sub.α-type compound.
The formula LXII compound is prepared from the formula LXI compound using the appropriate (ω-carboxyalkyl)triphenylphosphonium bromide, HOOC--(CH 2 ) g --CH 2 --P--(C 6 H 5 ) 3 Br, as is described above followed by transformation of the carboxy hydrogen to an R 1 moiety as described below. The formula LXIII compound is then prepared from the formula LXII compound by catalytic hydrogenation of the cis-5,6-double bond. Hydrogenation methods known in the art are employed, e.g., the use of metal catalysts under a hydrogen atmosphere. The reaction here is terminated when one equivalent of hydrogen is absorbed per equivalent of prostaglandin-type compound. Mixtures of compounds thereby produced are conveniently separated by silica gel chromatography.
Chart F provides a method whereby the prostaglandin-type intermediates of Charts B, C, D, and E are transformed to the corresponding 14-halo-PGF, 11-deoxy-14-halo-PGF, 14-halo-PGE, 11-deoxy-14-halo-PGE, 14-halo-PGA, or 14-halo-PGB compounds.
The formula LXXI compound is as prepared above. The formula LXXII PGE-type compound is prepared from the formula LXXI compound by oxidation methods known in the art. For example, the Jones reagent is advantageously employed herein. The formula LXXIII compound is then prepared from the formula LXXI compound or the formula LXXII compound by hydrolysis of any blocking groups. Such hydrolysis proceeds by mixing the reactant with, for example, water, tetrahydrofuran, and acetic acid as described above. The formula LXXIV compound is then prepared from the formula LXXIII compound by transformation of the R 1 moiety of the formula LXXXIII compound to its methyl ester. Methods hereinbelow described are employed. The C-15 epimers are then separated, thereby preparing the formula LXXV compound.
The formula LXXVI compound, which is represented by formula LXXIII when the M 5 moiety consists of separated C-15 epimers, is prepared optionally from the formula LXXV compound by transformation of the carboxy methyl ester of formula LXXV compound to an R 1 moiety as described above.
The formula LXXVII compound is prepared from the formula LXXVI compound wherein M 18 is =0 by a ring carbonyl reduction. Methods hereinbelow described are employed. The formula LXXIII and formula LXXIX compounds are prepared from the formula LXXVI wherein M 18 is ##STR98## employing an acidic or basic dehydration respectively. Methods described below for these acidic or basic dehydrations are employed.
The formula LXXVIII compound is optionally prepared from the formula LXXVI compound wherein R 8 is hydroxy by acetylation with acetic anhydride, thereby preparing a highly unstable corresponding PGE-type, 11,15-diacetate, followed by silica gel chromatography. The PGE-type 11,15-diacetate thereby spontaneously decomposes to the corresponding PGA-type 15-acetate, which is hydrolysed to yield the formula LXXVIII PGA-type product. Optionally, however, the 11,15-diacetate may be allowed to stand at room temperature whereby spontaneous decomposition will ordinarily be effected within one to five days.
The above acidic dehydrations are carried out by methods known in the art for acidic dehydrations of known prostanoic acid derivatives. See for reference Pike, et al., Proceedings of the Nobel Symposium 11, Stockholm (1966), Interscience Publishers, New York, pg. 162-163 (1967); and British Specification 1,097,533. Alkanoic acids of 2 to 6 carbon atoms, inclusive, preferentially acetic acid, are employed in this acidic dehydration. Dilute aqueous solutions of mineral acids e.g. hydrochloric acid, especially in the presence of a solubilizing diluent, e.g. tetrahydrofuran, are also useful as reagents for this acidic dehydration. Use, however, of mineral acids are described above may cause partial hydrolysis of the carboxy ester of the formula LXXVI PGE reactant.
The above basic hydrations or double bond migrations (i.e., conversion of the PGA-type compound to the PGBtype compound are carried out by methods known in the art for dehydration or double bond migration of known prostanoic acid derivatives. See for reference Bergstrom, et al., Journal of Biological Chemistry 238, 3555 (1963). Bases employed are any of those whose aqueous solution has pH greater than 10. Preferred bases are the alkali metal hydroxides. A mixture of water and sufficient quantity of a water miscible alkanol to yield a homogeneous reaction mixture is suitable as a reaction medium. The reactant is then maintained in such reaction medium until the starting material is completely reacted, as shown by the characteristic ultraviolet absorption of the PGB-type compound at 278 mμ.
In the employment of the processes above when C-15 tertiary alcohols are to be prepared (R 5 is methyl) the use of blocking groups is not required. Accordingly, in the steps of the above charts the introduction and hydrolysis of blocking groups are thereby omitted by the preferred process.
Certain (3RS)-3-methyl lactones of chart A may be separated into their respective (3S) or (3R)- epimers by silica gel chromatographic separation techniques. Where such separation is possible, this route is preferred. Accordingly, in these cases the separation is effected and M 5 is ##STR99## or ##STR100## and M 6 is ##STR101## or ##STR102## wherein R 10 is the blocking group. Accordingly, the separation procedure described in Chart F (formula LXII - LXXV) is omitted when the optional lactone separation is employed.
When a cis-4,5-didehydro-14-halo-PGF 1 .sub.α or cis 4,5-didehydro-11-deoxy-14-halo-PGF 1 .sub.α -type compound is to be prepared by the procedure of Chart D, the Wittig alkylation step LVI to LIX may be performed on the formula LIII lactol, instead of the formula LVI lactol, thereby eliminating the oxidation, etherification, and reduction steps of Chart D (LIII through LVI).
Charts G, H, I, and J provide methods whereby 3-oxa-3,7-inter-m-phenylene-4,5,6-trinor- or 3,7-inter-m-phenyl-ene-4,5,6-trinor-PG-type intermediates are prepared. With respect to Charts G and H, R 7 is preferred to be --(CH 2 ) m --CH 3 , or ##STR103## wherein m, T, and s are as defined above. In Charts I or J a method is provided for preparing those novel compounds of this specification wherein R 7 is preferably cis--CH=CH--CH 2 --CH 3 , or ##STR104## wherein T and s are as defined above, respectively. Accordingly the Charts G-J provide methods whereby intermediates useful in producing all inter-m-phenylene-PG-type compounds are prepared.
In Chart G both endo and exo forms of bicyclo hexene LXXXI are available or are made by methods known in the art, in either their racemic or enantiomerically pure forms. See U.S. Pat. No. 3,711,515. Either the endo or exo starting material will yield the ultimate intermediates of formula XCIII compound by the process of Chart G.
Oxetane LXXXII is obtained by reaction of the formula LXXXI bicyclo hexene with an aldehyde of the formula ##STR105## wherein R 63 is carboxyacyl of the formula ##STR106## wherein R 64 is hydrogen, alkyl of one to 19 carbon atoms, inclusive, or aralkyl of 7 to 12 carbon atoms, inclusive, wherein alkyl or aralkyl are substituted with zero to 3 halo atoms.
The above benzyl aldehydes are available or readily prepared by methods known in the art. Examples of such compounds within this scope are: ##STR107## and ##STR108##
The formation of oxetane LXXXII is accomplished by photolysis of a mixture of the bicyclo hexene and the aldehyde in a solvent. The bicyclo hexene is preferably used in excess over the molar equivalent, for example 2 to 4 times the stoichiometric equivalent amount. The solvent is a photochemically inert organic liquid, for example liquid hydrocarbons, including benzene or hexane, 1,4-dioxane, and diethyl ether. The reaction is conveniently run at ambient conditions, for example 25° C., but may be done over a wide range of temperature, from about -78° C. to the boiling point of the solvent. The irradiation is done with mercury vapor lamps of the low or medium pressure type, for example those peaking at 3500 A. Such sources are available from The Southern New England Ultraviolet Co., Middletown, Conn. Alternatively, those lamps which emit a broad spectrum of wavelengths and which may be filtered to transmit only light of λ ˜3000-3700 A may also be used. For a review of photoysis see D. R. Arnold in "Advances in Photochemistry", Vol. 6, W. A. Noyes et al., Wiley-interscience, New York, 1968, pp. 301-423.
The cleavage of the oxetane ring to yield the formula LXXXIII compound from the formula LXXXII compound is accomplished with an alkali metal in the presence of a primary amine or a alcohol. Preferred in lithium in ethylamine, or sodium in ethyl alcohol. See L. J. Altman et al., Synthesis 129 (1974). The cleavage transformation may also be accomplished by catalytic hydrogenation over an inert metal catalyst, e.g. Pd on carbon, in ethyl acetate or ethanol.
The formula LXXIV compound is prepared from the formula LXXXIII diol by preferably blocking the two hydroxyl groups with carboxyacyl groups according to R 63 , i.e. ##STR109## as defined above. For example, the diol is treated with an acid anhydride such as acetic anhydride, or with an acyl halide in a tertiary amine. Especially preferred is pivaloyl chloride in pyridine.
Other carboxyacylating agents useful for this transformation are known in the art or readily obtainable by methods known in the art, and include carboxyacyl halides, preferably chlorides, bromides, or fluorides, i.e. R 64 C(O)Cl, R 64 C(O)Br, or R 64 C(O)F, and carboxy acid anhydrides, (R 64 CO) 2 O, wherein R 64 is as defined above. The preferred reagent is an acid anhydride. Examples of acid anhydrides useful for this purpose are acetic anhydride, propionic anhydride, butyric anhydride, pentanoic anhydride, nonanoic anhydride, tridecanoic anhydride, steric anhydride, (mono, di, or tri)chloroacetic anhydride, 3-chlorovaleric anhydride, 3-(2-bromoethyl)-4,8-dimethylnonanoic anhydride, cyclopropaneacetic anhydride, 3-cycloheptanepropionic anhydride, 13-cyclopentanetridecanoic anhydride, phenylacetic anhydride, (2 or 3)-phenylpropionic anhydride, 13-phenyltridecanoic anhydride, phenoxyacetic anhydride, benzoic anhydride, (o, m, or p)-bromobenzoic anhydride, 2,4 (or 3,4-dichlorobenzoic anhydride, p-trifluoromethylbenbenzoic anhydride, 2-chloro-3-nitrobenzoic anhydride, (o, m, or p)-nitrobenzoic anhydride, (o, m, or p)-toluic anhydride, 4-methyl-3-nitrobenzoic anhydride, 4-octylbenzoic anhydride, (2,3, or 5)-biphenylcarboxylic anhydride, 3-chloro-4-biphenylcarboxylic anhydride, 5-isopropyl-6-nitro-3-biphenylcarboxylic anhydride, and ( 1 or 2)-naphthoic anhydride. The choice of anhydride depends upon the identity of R 64 in the final acylated product, for example when R 64 is to be methyl, acetic anhydride is used; when R 64 is to be 2-chlorobutyl, 3-chlorovaleric anhydride is used.
When R 64 is hydrogen, ##STR110## is formyl. Formylation is carried out by procedures known in the art, for example, by reaction of the hydroxy compound with the mixed anhydride of acetic and formic acids or with formylimidazole. See, for example, Fieser et al., Reagents for Organic Synthesis, John Wiley and Sons, Inc., pp. 4 and 407 (1967) and references cited therein. Alternatively, the formula LXXXIII diol is reacted with two equivalents of sodium hydride and then with excess ethyl formate.
In formula LXXXIV, R 68 may also represent a blocking group including benzoyl, substituted benzoyl, monoesterified phthaloyl and substituted or unsubstituted naphthoyl. For introducing those blocking groups, methods known in the art are used. Thus, an aromatic acid of the formula R 63 OH, wherein R 63 is as defined above, for example benzoic acid, is reacted with the formula LXXXIII compound in the presence of a dehydrating agent, e.g. sulfuric acid, zinc chloride, or phosphoryl chloride; or an anhydride of the aromatic acid of the formula (R 64 CO) 2 O, for example benzoic anhydride, is used.
Preferably, however, an acyl halide, e.g. R 63 Cl, for example benzoyl chloride, is reacted with the formula LXXXIII compound in the presence of a tertiary amine such as pyridine, triethylamine, and the like. The reaction is carried out under a variety of conditions using procedures generally known in the art. Generally, mild conditions are employed, e.g. 20°-60° C., contacting the reactants in a liquid medium, e.g. excess pyridine or an inert solvent such as benzene, toluene, or chloroform. The acylating agent is used either in stoichiometric amount or in excess.
As examples of reagents providing R 63 for the purposes of this invention, see the discussion above pertaining to the use of acyl protecting groups.
The formula LXXXIV acetal is converted to aldehyde LXXXV by acid hydrolysis, known in the art, using dilute mineral acids, acetic or formic acids, and the like. Solvents such as acetone, dioxane, and tetrahydrofuran are used.
For the conversion of LXXXV to LXXXIX, it is optional whether R 66 be hydrogen or a "blocking group" as defined below. For efficient utilization of the Wittig reagent it is preferred that R 66 be a blocking group. If the formula LXXXIV compound is used wherein R 68 is hydrogen, the formula LXXXV intermediate will have hydrogen at R 66 . If R 66 is to be a blocking group, that may be readily provided prior to conversion of LXXXV to LXXXVI by reaction with suitable reagents as discussed below.
The blocking group, R 65 , is any group which replaces hydrogen of the hydroxyl groups, which is not attacked by nor is reactive to the reagents used in the respective transformations to the extent that the hydroxyl group is, and which is subsequently replaceable by hydrogen at a later stage in the preparation of the prostaglandin-like products.
Several blocking groups are known in the art, e.g. tetrahydropyranyl, acetyl, and p-phenylbenzoyl (see Corey et al., J. Am. Chem. Soc. 93, 1491 (1971)).
Those which have been found useful include (a) carboxyacyl within the scope of R 63 above, i.e. acetyl, and also benzoyl, naphthoyl, and the like; (b) blocking groups according to R 10 ; and (c) -Si(G 1 ) 3 wherein G 1 is as defined above.
In replacing the hydrogen atoms of the hydroxyl groups with a carboxyacyl blocking group, methods known in the art are used. The reagents and conditions are discussed above for R 68 on the compound of formula LXXXIV.
When the blocking group is according to R 10 appropriate reagents and conditions are as defined above.
When the blocking group is silyl of the formula --Si(G 1 ) 3 , the formula LXXXIV compound is transformed to a silyl derivative of formula LXXXV by procedures known in the art. See, for example, Pierce, "Silylation of Organic Compounds," Pierce Chemical Co., Rockford, illinois (1968). The necessary silylating agents for these transformations are known in the art or are prepared by methods known in the art. See, for example, Post "Silicones and Other Silicon Compounds," Reinhold Publishing Corp., New York, N.Y. (1949). These reagents are used in the presence of a tertiary base such as pyridine at temperatures in the range of about 0° to +50° C. Examples of trisubstituted monochlorosilanes suitable for this purpose include chlorotrimethylsilane, chlorotriisobutylsilane, chlorotriphenylsilane, chlorotris(p-chlorophenyl)silane, chlorotri-m-tolylsilane, and tribenzylchlorosilane. Alternatively, a chlorosilane is used with a corresponding disilazane. Examples of other silylating agents suitable for forming the formula LXXXV intermediates include pentamethylsilylamine, pentaethylsilylamine, N-trimethylsilyldiethylamine, 1,1,1-triethyl-N,N-dimethylsilylamine, N,N-diisopropyl-1,1,1-trimethylsilylamine, 1,1,1-tributyl-N,N-dimethylsilylamine N,N-dibutyl-1,1,1-trimethylsilylamine, 1-isobutyl-N,N,1,1 -tetramethylsilylamine, N-benzyl-N-ethyl-1,1,1-trimethylsilylamine, N,N,1,1-tetramethyl-1-phenylsilylamine, N,N-diethyl-1,1-dimethyl-1-phenylsilylamine, N,N-diethyl-1-methyl-1,1-diphenylsilylamine, N,N-dibutyl-1,1,1-triphenylsilylamine, and 1-methyl-N,N,1,1-tetraphenylsilylamine.
In transforming the formula LXXXV compound to the formula LXXXVI compound the aldehyde group is transformed by the Wittig reaction to a moiety of the formula ##STR111## For this purpose of phosphonium salt prepared from an organic chloride or bromide of the formula ##STR112## or ##STR113## is employed, wherein L 1 , R 7 , and R 53 are as defined above. These organic chlorides or bromides are known in the art or are readily prepared by methods known in the art. See for example the above-identified German Offenlegungsschrift No. 2,209,990. As to the Wittig reaction, see, for example, U.S. Pat. No. 3,776,941 and references cited therein.
The formula LXXXVII compound is obtained by deblocking if necessary. When R 66 is a hindered carboxyacyl, R 66 on the phenolic hydroxy is selectively replaced with hydrogen by hydrolysis with sodium or potassium hydroxide in ethanolwater. Instead of ethanol, other water-miscible solvents may be substituted, for example 1,4-dioxane, tetrahydrofuran, or 1,2-dimethoxyethane. The selective hydrolysis is preferably carried out at -15° to 25° C. Higher temperatures may be used but with some decrease in selectivity.
Total hydrolysis of R 66 blocking groups on the formula LXXXVI compound is accomplished, when R 66 is carboxyacyl, with an alkali alkoxide in an alcoholic solvent, preferably sodium methoxide in methanol at a temperature from 25° C. to 50° C. When R 66 is trialkylsilyl, either aqueous acid or base are used at 25° to 50° C.
Continuing with Chart G, a Williamson synthesis is employed to obtain the fomula LXXXVIII compound. The formula LXXXVII phenol is condensed with a haloalkanoate within the scope of Hal--(CH 2 ) g --COOR 1 wherein Hal is chloro, bromo, or iodo and g and R 1 are as defined above. Normally the reaction is done in the presence of a base such as n-butyllithium, phenyllithium, triphenylmethyllithium, sodium hydride, potassium t-butoxide, sodium hydroxide, or potassium hydroxide.
The transformation of the formula LXXXVIII compound to the formula LXXXIX is accomplished by any one of several routes known in the art. See U.S. Pat. No. 3,711,515. Thus, the alkene LXXXVIII is hydroxylated to glycol LXXXIX. For this purpose osmium tetroxide is a suitable reagent, for example in conjunction with N-methylmorpholine oxidehydrogen peroxide complex (see Fieser et al., "Reagents for Organic Synthesis", p. 690, John Wiley and Sons, Inc., New York (1967)). Thereafter, several methods are available for obtaining the formula XC product. In one method the glycol is converted to a bis(alkanesulfonic acid) ester and subsequently hydrolyzed to the formula XC compound by methods known in the art (See, for example German Offenlegungsschrift No. 1,936,676, Derwent Farmdoc No. 6862R). Another method is by way of a diformate by formolysis of the glycol (see U.S. Pat. No. 3,711,515).
Still another method is by way of a cyclic ortho ester. For this purpose, glycol LXXXIX is reacted with an ortho ester of the formula ##STR114## wherein R 74 is hydrogen, alkyl of one to 19 carbon atoms, inclusive, or aralkyl of 7 to 12 carbon atoms, inclusive, substituted with zero to 3 halo atoms; and R 75 is methyl or ethyl. There is then formed a cyclic orthoester of the formula ##STR115## wherein g, R 1 , R 53 , R 66 , R 74 , R 75 , L 1 and R 7 are as defined above. The reaction goes smoothly in a temperature range of -50° C. to +100° C., although for convenience 0° C. to +50° C. is generally preferred. From 1.5 to 10 molar equivalents of the ortho ester are employed, together with an acid catalyst. The amount of the catalyst is usually a small fraction of the weight of the glycol, e.g., about 1%, and typical catalysts include pyridine hydrochloride, formic acid, hydrogen chloride, p-toluenesulfonic acid, trichloroacetic acid, or trifluoroacetic acid. The reaction is preferably run in a solvent, for example benzene, dichloromethane, ethylacetate, or diethyl ether. It is generally completed within a few minutes and is conveniently followed by TLC (thin layer chromatography on basic silica gel plates).
The ortho ester reagents are known in the art or readily available by methods known in the art. See for example S. M. McElvain et al., J. Am. Chem. Soc. 64, 1925 (1942), starting with an appropriate nitrile. Examples of useful ortho esters include:
trimethyl orthoformate,
triethyl orthoacetate,
triethyl orthopropionate,
trimethyl orthobutyrate,
trimethyl orthovalerate,
trimethyl orthooctanoate,
trimethyl orthophenylacetate, and
trimethyl ortho (2,4-dichlorophenyl)acetate.
Preferred are those ortho esters wherein R 74 is alkyl of one to 7 carbon atoms; especially preferred are those wherein R 74 is alkyl of one to 4 carbon atoms.
Next, the cyclic orthoester dipicted above is reacted with anhydrous formic acid to yield a diol diester of the formula ##STR116## wherein g, R 1 , R 7 , R 53 , R 66 , and L 1 are as defined above.
Anhydrous formic acid refers to formic acid containing not more than 0.5% water. The reaction is run with an excess of formic acid, which may itself serve as the solvent for the reaction. Solvents may be present, for example dichloromethane, benzene, or diethyl ether, usually not over 20% by volume of the formic acid. There may also be present organic acid anhydrides, for example acetic anhydride, or alkyl orthoesters, for example trimethyl orthoformate, which are useful as drying agents for the formic acid. Although the reaction proceeds over a wide range of temperatures, it is conveniently run at about 20°-30° C. and is usually completed within about 10 minutes.
Finally, the diol diester above is converted to product XC by methods known in the art, for example by hydrolysis in the presence of a base in an alcoholic medium. Examples of the base are sodium or potassium carbonate or sodium or potassium alkoxides including methoxides or ethoxides. The reaction is conveniently run in an excess of the solvolysis reagent, for example methanol or ethanol. The temperature range is from -50° C. to 100° C. The time for completion of the reaction varies with the nature of R 74 and the base, proceeding in the case of alkali carbonates in a few minutes when R 74 is hydrogen but taking up to several hours when R 74 is ethyl, for example.
When the solvolysis proceeds too long or when conditions are too severe, an ester group (R 1 ) is often removed. They are, however, readily replaced by methods known in the art. See the discussion below.
The formula XCI compound is prepared from the formula XC compound by oxidation of the C-15 hydroxy to a 15-oxo. Accordingly, as is known in the art, 2,3-dichloro-5,6-dicyano-1,4-benzoquinone, activated manganese dioxide, or nickel peroxide (See Fieser, et al., "Reagents for Organic Synthesis", John Wiley and Sons, New York, N.Y., pgs. 215, 637, and 731) is advantageously employed. Thereafter, the formula XCI compound is prepared from the 15-oxo compound by transforming the C-9 and C-11 hydroxy hydrogens to R 65 blocking groups. Procedures known in the art are employed. See for reference Pierce, "Silylation of Organic Compounds," Pierce Chemical Company, Rockford, Ill. (1968) and the discussion above pertaining to the introduction of blocking groups according to R 10 . The necessary silylating reagents for these transformations are known in the art or are prepared by methods known in the art. See for reference, Post, "Silicones and Other Silicone Compounds," Reinhold Publishing Corp., New York, N.Y. (1949).
The formula XCII compound is then prepared from the formula XCI compound by the procedure described in Chart A for transforming the formula XXII compound to the formula XXIV compound, followed by hydrolysis of the silyl groups, using, for example, dilute aqueous acetic acid in a water miscible solvent, such as ethanol (sufficient to yield a homogeneous reaction mixture). At 25° C., the hydrolysis is ordinarily complete in 2 to 12 hrs. Further, the hydrolysis preferably carried out in an inert atmosphere, e.g., nitrogen or argon.
The formula XCIII compound is prepared from the formula XCII compound by separation of the 15-methyl epimers when present. Such separation proceeds by methods discussed above for accomplishment of this purpose (e.g., thin layer chromatography or high pressure liquid chromatography).
Referring to Chart H, there are shown process steps by which the formula XCVI bicyclo hexene is transformed first to an oxetane (formula XCVII) with a fully developed side chain, e.g., ##STR117## wherein Z 3 is oxa or methylene, and ultimately to the formula CIV compound.
In transforming XCVI to XCVII in Chart H, there is employed an aldehyde of the formula ##STR118## wherein Z 3 and R 69 are as defined above. Such aldehydes are available or are readily prepared by methods known in the art, e.g., ##STR119##
The conditions for this transformation are essentially the same as for the corresponding step of Chart G (i.e., LXXXI to LXXXII). Thereafter, the preparation of the formula CI compound proceeds by methods analogous and by employing the same conditions as the corresponding steps of Chart G (i.e., LXXXII to LXXXVI).
The steps transforming CI to CIV then proceed in similar fashion, employing the same or similar reagents and conditions as the corresponding steps of Chart G discussed above.
Referring next to Chart I the process steps are shown whereby aldehyde CVI prepared in Chart H is transformed to a 17,18-tetradehydro-PG intermediate (formula CIX) and 17,18-didehydro-PG intermediate (formula CX).
In Chart I, a Wittig reagent is employed which is prepared from a phosphonium salt of a haloalkyne of the formula ##STR120## or ##STR121## wherein R 53 and L 1 are as defined above, (See, for example, U. Axen et al., Chem. Comm. 1969, 303, and ibid. 1970, 602) in transforming CVI to CVII.
Thereafter, in subsequent transformations yielding the 17,18-tetradehydro compound CIX, the reagents and conditions are similar to those employed for the corresponding reactions shown in Chart H.
Transformation of the formula CIX compound to the formula CX compound is accomplished by hydrogenation of CIX using a catalyst which catalyzes hydrogenation of --C.tbd.C-- only to cis--CH=CH--, as known in the art. See, for example, Fieser et al., "Reagents for Organic Syntheses", pp. 566-567, John Wiley and Sons, Inc., New York (1967). Preferred is Lindlar catalyst in the presence of quinoline. See Axen, references cited above.
As discussed above, Chart J provides a method whereby the formula CXI PG-type intermediate, prepared according to Chart G or Chart H is transformed to the corresponding formula CXIV 16-phenoxy-PG-type intermediates.
The formula CXII compound is prepared from the formula CXI compound by cleavage of the 13,14-trans double bond, conveniently by ozonolysis. Ozonolysis proceeds by bubbling dry oxygen, containing about 3 percent ozone, through a mixture of a formula CXI compound in a suitable nonreactive diluent. For example, n-hexane is advantageously employed. The ozone may be generated using methods known in the art. See, for example, Fieser, et al., "Reagents for Organic Synthesis," John Wiley and Sons, Inc. (1967), pages 773-777. Reaction conditions are maintained until the reaction is shown to be complete, for example, by silica gel thin layer chromatography or when the reaction mixture no longer rapidly decolorizes a dilute solution of bromine in acetic acid.
The formula CXIII compound is then prepared from the formula CXII compound employing a phosphonate of the formula: ##STR122## wherein R 15 , L 1 , T, and s are as defined above. Phosphonates of this general formula are prepared by methods known in the art. See the text hereinabove accompanying Chart A for discussion of the preparation and the appropriate reaction conditions by which the Wittig reaction proceeds. The formula CXIV compound is prepared from the formula CXIII compound by transformation of the 15-oxo moiety to an M 1 moiety. Methods hereinabove, particularly those discussed in Charts G and H above, are employed.
Optionally the method of Chart J is used to introduce the various other R 7 moieties to the formula CXII compound using the appropriate phosphonate.
Chart K provides a method whereby the formula CXXI bicyclic lactone aldehyde is transformed to the corresponding formula CXXIV PGF 2 .sub.α -type intermediate which is useful according to the procedures of Chart L in preparing the novel 13,14-didehydro-PGF 2 .sub.α -type compounds disclosed in this specification.
The formula CXXI compound is known in the art. This compound is available in either of its two pure enantiomeric forms or as a mixture comprising both of these enantiomers. The formula CXXII compound is prepared from the formula CXXI compound using reagents and conditions analogous to the preparation of the formula XXIII compound of Chart A from the formula XXI compound. Thus, methods generally known to the art are employed. The formula CXXIII compound is then prepared from the formula CXXII compound using reaction conditions and reagents analogous to the preparation of the formula XXXV compound from the formula XXXI compound (Chart B), the preparation of the formula XLIII compound from the formula XLI compound (Chart C), - the preparation of the formula LVIII or LIX compound from the formula LI compound (Chart D), or the preparation of the formula LXIII compound from the formula LXI compound (Chart E). Thereafter the formula CXXIV compound is prepared from the formula CXXIII compound by first hydrolyzing any blocking groups according to R 10 , (using procedures and methods hereinabove described), and second separating the C-15 epimers when R 5 is methyl. Methods herein described (e.g., silica gel chromatography or high pressure liquid chromatography) are employed.
Further by the procedure of Chart F, the various PGF.sub.α- or 11-deoxy-PGF.sub.α-type compounds prepared according to Charts G, H, I, J, or K are transformed to corresponding PGE or 11-deoxy-PGE-, PGF.sub.β- or 11-deoxy-PGF.sub.β-, PGA-, or PGE-type compounds.
Chart L provides a method whereby the formula CXXXI compound (as known in the art, or as prepared herein) is transformed to the corresponding formula CXXXVI 14-halo-PGF- or 11-deoxy-PGF-type product.
The formula CXXXII compound is prepared from the formula CXXXI compound by selective oxidation of the C-15 alcohol. The oxidation is accomplished employing conventional methods known in the art, for example, the use of 2,3-dichloro-5,6-dicyanobenzoquinone, activated manganese dioxide, or nickel peroxide. See Fieser, et al. "Reagents for Organic Synthesis" John Wiley and Sons, New York, N.Y. pages 215, 637, and 731.
The formula CXXXIII compound is prepared from the formula CXXXII compound by protection of free hydroxy moieties with acyl protecting groups according to R 9 . Methods described hereinabove for preparing these acyl derivatives are employed. Optionally, however, silyl groups within the scope of --Si(G 1 ) 3 , wherein G 1 is defined above, are employed in place of the acyl protecting groups. Finally, the acyl protection or silylation described herein is optionally omitted, particularly, where R 5 and R 6 of the M 1 moiety of the formula CXXXVI compound are both hydrogen.
The formula CXXXIV compound is prepared from the formula CXXXIII compound by 14-halogenation. This 14-halogenation is achieved by one of several general methods known in the art. For example, following the procedure of Chart A wherein the formula XXIII compound is prepared from the formula XXII compound, formula CXXXIV compound herein is prepared. As especially useful reagent for the instant transformation is sulfuryl chloride, as described above. Mixtures of products produced are separated, using conventional techniques. The formula CXXXV compound is then prepared from the formula CXXXIV compound by transformation of the 15-oxo to an M 1 moiety. Techniques as described hereinabove are employed. Thereafter, the formula CXXXVI compound is prepared from the formula CXXXV compound by removal of the optionally present acyl or silyl protecting groups, following the procedures described hereinabove.
Chart M provides a method whereby the 14-halo-8β,12α-PG-type compounds of formulas CSLVI and CXLVII are prepared from the formula CXXXVIIa or formula CXXXVIIb enantiomeric starting material, which compounds are known in the art or readily prepared by methods known in the art. With respect to Chart M, R 51 is R 30 --SO 2 --, wherein R 30 is alkyl, cycloalkyl, aralkyl, phenyl, or phenyl substituted with alkyl or halogen, but preferably methyl or p-tolyl.
By the procedure of Chart M the formula CXXXVIIa compound is transformed to the formula CXXXVIII compound by the procedure described in Chart A for the preparation of the formula XXIV compound from the formula XXI compound. Thereafter, the formula CXXXIX compound is prepared from the formula CXXXVIII compound by the method described in Chart A for the preparation of the formula XXVI compound from the formula XXV compound. Thereafter the formula CXXXIX compound is deacylated following the procedure described in Chart A for the preparation of the formula XXV compound from the formula XXIV compound. Following deacylation the formula CXLI compound prepared from the formula CXL compound by sulfonation. Thereby, the alkyl, aralkyl, cycloalkyl, phenyl or substituted phenyl sulfonyl derivative of the formula CXL compound is prepared. This sulfonation proceeds by a method analogous to the acylation, employing protecting groups according to R 9 , described hereinabove. Thus, for example, the sulfonyl chloride, e.g., mesyl chloride (methane sulfonyl chloride) or tosyl chloride (p-toluenesulfonyl chloride) is reacted with the hydroxy containing compound in the presence of a catalytic amount of an amine base (e.g. pyridine).
Thereafter the 11β-sulfonyl moiety is transformed to an 11α-acyl moiety employing the sodium, potassium or lithium salt of the corresponding carboxylicacid. Thus, for example when R 9 is benzoyl the formula CXLI sulfonyl derivative is reacted with sodium, potassium or lithium benzoate in an inert diluent (preferably, in a polar aprotic solvent) to yield the formula CXLII compound. As described above the carboxylic acids of the formula R 9 OH are known in the art or readily prepared by methods known in the art. Further, these acids are transformed into the sodium, potassium or lithium salts employing conventional methods.
Thereafter, the formula CXLII compound is transformed to the formula CXLIII compound by selective deacylation of the R 9 protecting group. Methods described hereinabove for deacylation are employed (see the transformation of the formula CXXXIX compound to the formula CXL compound).
Thereafter the formula CXLIV compound is prepared from the formula CXLIII compound by transforming the 11-hydroxy hydrogen to a blocking group by methods hereinabove described or by transformation of the formula CXXXVIIb compound employing the methods and procedures described hereinabove for the preparation of the formula XXVI compound from the formula XXI compound.
Finally following the procedure of Chart A the formula CXLIV compound is transformed to the formula CXLV compound and thereafter the formula CXLV compound (following the procedure of Charts A-F) is transformed to the formula CXLVI and formula CXLVII compounds.
Chart N provides a method whereby PGA-type compounds are transformed into corresponding 11-deoxy PGE-type compounds, according to formula CLII or CLVI.
The formula CLII compound is prepared from the formula CLI compound by selective catalytic hydrogenation of the cyclopentene ring olefinic unsaturation. This transformation is selectively effected without affecting sidechain unsaturation. For this purpose a 5 to 10 percent palladium or rhodium catalyst on carbon, alumina or other suitable support is employed. The reaction is carried out in any suitable organic solvent, e.g. ethyl acetate, methanol, ethanol, or diethyl ether at temperatures of -30 to +50° C. and pressures greater than or equal to the atmospheric pressure, but less than several atmospheres.
The formula CLIII compound is prepared from the formula CLI compound by replacing any free hydroxy hydrogen with a blocking group, according to R 31 .
This blocking group function prevents attack on the hydroxy by subsequent reagents, especially the reagent employed herein for the transformation of the C-9 hydroxy to a C-9 oxo group. This blocking group further functions so as to be replaceable by hydrogen at a later stage in the preparation of the prostaglandin-type products. Blocking groups, according to R 31 , which are useful for these purposes include alkanoyl of 2 to 12 carbon atoms, inclusive, tetrahydropyranyl, tetrahydrofuranyl, a group of the formula
--C(R.sub.11)(OR.sub.12)--CH(R.sub.13)(R.sub.14),
wherein R 11 , R 12 , R 13 , and R 14 are as defined above, and a silyl group of the formula --Si(G 1 ) 3 , wherein G is alkyl of one to 4 carbon atoms, inclusive, phenyl, phenyl substituted with one or 2 fluoro, chloro, or alkyl of one to 4 carbon atoms, inclusive, or aralkyl of 7 to 12 carbon atoms, inclusive.
The transformations of Chart N which involve replacing any hydroxy hydrogen with a blocking group according to R 31 employ methods known in the art. Further subsequent hydrolysis of these blocking groups according to R 31 proceeds by methods known in the art.
When the blocking group is of the formula
--C(R.sub.11)(OR.sub.12)--CH(R.sub.13)(R.sub.14),
wherein R 11 , R 12 , R 13 , and R 14 are as defined above, the appropriate reagent is a vinyl ether, e.g. isobutyl vinyl ether or any vinyl ether of the formula
C(R.sub.11)(OR.sub.12)=C(R.sub.13)(R.sub.14),
wherein R 11 , R 12 , R 13 , and R 14 are as defined above; or an unsaturated cyclic or heterocyclic compound, e.g. 1-cyclohexen-1-yl methyl ether or 5,6-dihydro-4-methoxy-2H-pyran. See C. B. Reese, et al., Journal of the American Chemical Society 89, 3366 (1967). The reaction conditions for such vinyl ethers and unsaturates are similar to those for dihydropyran above.
The subsequent hydrolysis of these blocking groups according to R 31 proceeds by methods known in the art. Silyl groups are readily removed by prior art procedures known to be useful for transforming silyl ethers and silyl esters to alcohols and carboxylic acids, respectively. For reference see Pierce, cited above, especially page 447 thereof. A mixture of water and a sufficient quantity of a water miscible organic diluent to yield the homogeneous reaction mixture represents a suitable reaction medium. Addition of a catalytic amount of an organic or inorganic acid hastens the hydrolysis. The length of time required for hydrolysis is determined in part by temperature. With a mixture of water and methanol at 25° C. several hours is usually sufficient for hydrolysis. At 0° C., several days are required.
For the hydrolysis of the various other blocking groups according to R 31 mild acidic conditions are employed.
The formula CLIV compound is prepared from the formula CLIII compound by reduction of the formula CLIII compound with reducing agent which selectively effects reduction of the ring unsaturation and reduction of the C-9 oxo group to a C-9 hydroxy group, without reducing side chain unsaturation. For this purpose as alkali metal borohydride, e.g. sodium, potassium, or lithium borohydride is effectively employed in aqueous solution. The reaction is carried at about -20° C. and is complete within a few minutes.
The formula CLV compound is prepared by oxidation of the formula CLIV compound using an oxidizing reagent, such as the Jones reagent (acidified chromic acid). See for reference Journal of the Chemical Society 39 (1946). A slight stoichiometric excess beyond the amount necessary to oxidize a single hydroxy group is employed. Acetone is a useful diluent for this purpose. Reaction temperatures at least as low as about 0° C. should be used. Preferred reaction temperatures are in the range of -10° to -50° C. An especially useful reagent for this purpose is the Collins reagent (chromium trioxide in pyridine). See for reference J. C. Collins, et al., Tetrahedron Letters 3363, (1968). Dichloromethane is a suitable diluent for this purpose. Reaction temperatures below 30° C. are preferred. Reaction temperatures in the range of -10° to +10° C. are especially preferred. This oxidation proceeds rapidly and is complete within several minutes. The formula CLV compound may then be isolated by conventional methods, e.g. silica gel chromatography.
Examples of other oxidation reagents useful for this transformation are silver carbonate on celite (Chemical Communications 1102 (1969)), mixtures of chromium trioxide in pyridine (Journal of the American Chemical Society 75, 422 (1953), and Tetrahedron Letters, 18, 1351 (1962)), tert-butyl chromate in pyridine (Biological Chemical Journal, 84, 195 (1962)), mixtures of sulfur trioxide in pyridine and dimethyl sulfoxide (Journal of the American Chemical Society 89, 5505 (1967)), and mixtures of dicyclohexylcarbodiimide and dimethyl sulfoxide (Journal of the American Chemical Society 87, 5661 (1965)).
The formula CLVI compound is then prepared from the formula CLV compound by hydrolysis of the blocking groups, according to R 31 , as described above.
From the formula CLVI 11-deoxy-PGE-type compound, there is prepared the corresponding 11-deoxy-PGF.sub.α- or PGF.sub.β-type compound. Further, employing the 8β,12α-PGA-type compound corresponding to the formula CXLVI PGA-type compound, there are prepared the corresponding 8β,12α-11-deoxy-PGE-, PGF.sub.α-, or PGF.sub.β-type products.
Chart O provides a method whereby the formula CLXI, 8β,12α-PGA-type compound is transformed to the formula CLXVII 8β,12α-PGF.sub.α-, PGF.sub.β-, or PGE-type compounds.
The formula CLXI compound is prepared hereinabove. The formula CLXII compound is then prepared from the formula CLXI compound by the procedure described hereinabove for the preparation of the formula CLIII compound from the formula CLI compound. Thereafter the formula CLXIII compound, the formula CLXIV compound, formula CLXV compound, and formula CLXVI compound are successively prepared from the formula CLXII compound employing methods known in the art. See for reference Belgian Pat. No. 804,873, Derwent Farmdoc CPI No. 22865V/13, and G. L. Bundy et al., J. Am. Chem. Soc. 94, 2123 (1972). There are first formed the formula CXLIII 10,11-epoxides, using any agent known to epoxidize an α,β-unsaturated ketone without reacting with isolated carbon-carbon double bonds, for example, see Steroid Reactions, Carl Djerassi, ed., Holden-Day Inc., 1963, P 593. Especially preferred are aqueous hydrogen peroxide or an organic tertiary hydroperoxide. See, for example, Organic Peroxides, A. V. Tobolsky et al., Interscience Publishers, N.Y., 1954. For this purpose, the peroxide or hydroperoxide is employed in an amount of at least one equivalent per mole of formula CLXII reactant in the presence of a strong base, e.g., an alkali metal hydroxide, a metal alkoxide, or a quaternary ammonium hydroxide. For example, there is employed lithium hydroxide, sodium hydroxide, potassium hydroxide, lithium ethoxide, lithium octyloxide, magensium methoxide, megnesium isopropoxide, benzyltrimethylammonium hydroxide, and the like.
It is advantageous to use an inert liquid diluent in the epoxidation step to produce a mobile homogeneous reaction mixture, for example, a lower alkanol, dioxane, tetrahydrofuran, dimethoxyethane, dimethylsulfoxide, or dimethylsulfone. A reaction temperature in the range -60° to 0° C. is generally preferred, especially below -10° C. At a temperature of -20° C., the epoxidation is usually complete in 3 to 6 hours. It is also preferred that the reaction be carried out in an atmosphere of an inert gas, e.g., nitrogen, helium, or argon. When the reaction is complete as shown by the absence of starting material on TLC plates (5% acetone in dichloromethane), the reaction mixture is neutralized, and the epoxy product is isolated by procedures known in the art, for example, evaporation of the diluent and extraction of the residue with an appropriate water-immiscible solvent, e.g., ethyl acetate.
This transformation of CLXII to CLXIII usually produces a mixture of formula CLXIII alpha and beta epoxides. Although these mixtures are separable into the individual alpha and beta isomers, for example, by chromatography by procedures known to be useful for separating alpha and beta epoxide mixtures, it is usually advantageous to transform the formula CLXIII mixture of alpha and beta epoxides to the corresponding mixture of formula CLXIV 11α- and 11β-hydroxy compounds. The latter mixture is then readily separated into the 11α and 11β compounds, for example, by chromatography on silica gel.
Referring again to Chart O, the transformation of epoxide CLXIII to hydroxy compound CLXIV is accomplished by reduction with chromium (II) salts, e.g., chromium (II) chloride or chromium (II) acetate. Those salts are prepared by methods known in the art. This reduction is carried out by procedures known in the art for using chromium (II) salts to reduce epoxides of αβ-unsaturated ketones tp β-hydroxy ketones. See, for example, Cole et al., J. Org. Chem. 19, 131 (1954), and Neher et al., Helv. Chem. Acta 42, 132 (1959). In these reactions, the absence of air and strong acids is desirable.
Amalgamated aluminum metal has also been found to be useful as a reducing agent in place of chromium (II) salts for the above purpose. Amalgamated aluminum is prepared by procedures known in the art, for example, by contacting aluminum metal in the form of foil, thin sheet, turnings, or granules with a mercury (II) salt, for example, mercuric chloride, advantageously in the presence of sufficient water to dissolve the mercury (II) salt. Preferably, the surface of the aluminum metal is free of oxide. That is readily accomplished by physical removal of the usual oxide layer, e.g., by abrasion or scraping, or chemically, e.g., by etching with aqueous sodium hydroxide solution. It is only necessary that the aluminum surface be amalgamated. The amalgamated aluminum should be freshly prepared, and maintained in the absence of air and moisture until used.
The reductive opening of the formula CLXIII epoxide ring is accomplished by contacting said epoxide with the amalgamated aluminum in the presence of a hydroxylic solvent and sufficient inert organic liquid diluent to give a mobile and homogeneous reaction mixture with respect to the hydroxylic solvent and said epoxide. Among hydroxylic solvents, water is especially preferred although lower alkanols, e.g., methanol and ethanols are also operable.
Examples of inert organic liquid diluents are normally liquid ethers such as diethyl ether, tetrahydrofuran, dimethoxyethane, diglyme (dimethyl ether of diethylene glycol), and the like. Especially preferred is tetrahydrofuran. When a water-immiscible liquid diluent is used, a mixture of water and methanol or ethanol is especially useful in this reaction since the latter two solvents also aid in forming the desired homogeneous reaction mixture. For example, a mixture of diethyl ether and water is used with sufficient methanol to give a homogeneous reaction mixture. Thereafter the formula CLXV compound is prepared from the formula CLXIV compound by separating the 11α-hydroxy epimer from the 11- epimeric mixture. Thereafter, the formula CLXVI compound is prepared from the formula CLXV compound by removal of the blocking groups, using methods described in Chart N wherein the formula CLV compound is transformed to the formula CLV compound. Thereafter, the formula CLXVII compound is prepared from the formula CLXVI compound using the procedures described herein in Chart F, i.e. the preparation of the formula LXXIII compound from the formula LXXII compound.
Optionally, the procedure of Chart O is followed, except that 13,14-didehydro-8β,12α-PGA-type starting material is used in place of 14-halo-8β,12α-PGA-type starting material, and accordingly 13,14-didehydro-PG-type products are prepared. Thus the procedure of Chart O is followed except that in place of the Y 2 moiety in the formulas of Chart O, the Y 1 moiety is present.
Chart P provides a method whereby the formula CLXXI PGF .sub.α or 11-deoxy-PGF.sub.α -type starting material, as prepared herein, is transformed into the corresponding PGE-type compound by selective silylation of all hydroxy hydrogens of the formula CLXXI compound, other than the C-9 hydroxy.
The formula CLXXII compound is prepared from the formula CLXXI compound by selective silylation of the various hydroxy groups of the formula CLXXI compound over the C-9 hydroxy. Silyl groups with the scope --Si(G 1 ) 3 , wherein G is alkyl of 1 to 4 carbon atoms, inclusive, aralkyl of 7 to 12 carbon atoms, inclusive, phenyl, phenyl substituted with one or 2 chloro, fluoro, or alkyl of one to 4 carbon atoms, inclusive, with the proviso that the various G's of the --Si(G) 3 moiety are the same or different, are employed. These reagents are known in the art and their use is known in the art.
For the selective silylation procedure of Chart P procedures known in the art for selective silylation of known prostanoic acid derivatives are employed. See for reference U.S. Pat. No. 3,822,303 (issued July 2, 1974), German Offenlegungschrift 2,259,195 (Derwent Farmdoc CPl 36457U-B), and Netherlands Pat. No. 7,214,142 (Derwent Farmdoc CPl 26221U-B).
Examples of the --Si(G 1 ) 3 moiety are trimethylsilyl, dimethyl(tert-butyl)silyl, dimethyl phenyl silyl, and methylphenylsilyl. Examples of alkyl of one to 4 carbon atoms, inclusive, aralkyl of 7 to 12 carbon atoms, inclusive, and phenyl or substituted phenyl moieties are provided hereinabove.
The formula CLXXIII compound is prepared from the formula CLXXII compound by oxidation of the C-9 hydroxy to a C-9 oxo. Oxidation reagents and methods known in the art are employed. For example, the Jones reagent is advantageously employed as discussed above.
The formula CLXXIV compound is prepared from the formula CLXXIII compound by hydrolysis of the silyl groups. Hydrolysis proceeds by methods known in the art, e.g. the use of water or dilute aqueous acetic acid in a diluent of water and a quantity of water micible solvent sufficient to yield a homogeneous reaction mixture. This hydrolysis is ordinarily complete within 2 to 12 hours at 25° C., and is preferably carried in an atmosphere of an inert gas such as nitrogen or argon.
Optionally the procedure of Chart P is used to transform 13,14-didehydro-PGF .sub.α -type products to corresponding 13,14-didehydro-PGE-type products. Accordingly, in this alternate process Y 2 in this Chart is defined to be --C.tbd.C-- instead of trans--CH=C(Hal)--.
Chart R provides a method whereby the 14-halo compounds described herein are transformed corresponding 13,14-dihydro-PG-type products.
The transformation of Chart R (the formula CLXXXI compound to the formula CLXXXII compound) proceeds by dehydrohalogenation. By the preferred method the reaction proceeds using as a reaction diluent a mixture of dimethylsulfoxide, or silimar aprotic solvent, and methanol in ratio by volumn between 5:1 and 10:1. Thereafter a strong organic base, for example potassium t-butoxide or sodium methoxide is added and the reaction is allowed to proceed to completion, ordinarily within about 24 hours. Reaction temperatures between 0° -25° C. are employed for convenience.
When this dehydrohalogenation procedure is employed using PGE-- or PGA-type compounds or 8β,12α-PGE- or PGA-type compounds undesired dehydration and/or double bond migration occurs. Accordingly, it is preferred that these dehydrations be performed on PGF-type reactants and thereafter the corresponding 13,14-didehydro-PGF-type compounds be transformed respectively to 13,14-didehydro-PGE- or PGA-type products, by procedures described hereinabove. Accordingly, by this preferred method the 14-halo-PGF compound is successively transformed to a 13,14-didehydro-PGF-type compound and thereafter to 13,14-didehydro-PGE- or PGA-type compounds.
Optically active PG-type products are obtained from optically active intermediates, according to the process steps of the above charts. Likewise optically active PG-type compounds are obtained from corresponding optically active PG-type compounds following the procedures in the above charts. When racemic intermediates are used in the reactions above, racemic products are obtained. These products may be used in their racemic form or if preferred they may be resolved as optically active enantiomers following procedures known in the art. For example, when a PG-type free acid is obtained, the racemic form thereof is resolved into d and l forms by reacting said free acid by known procedures with an optically active base (e.g., brucine or strychnine) thereby yielding a mixture of 2 diastereomers which are separable by procedures known in the art (fractional crystallization to yield the separate diastereomeric salts). The optically active acid may then be prepared from the salt by general procedures known to the art.
In all of the above described reactions, the products are separated by conventional means from starting material and impurities. For example, by use of silica gel chromatography monitored by thin layer chromatography the products of the various steps of the above charts are separated from the corresponding starting materials and impurities.
As discussed above, the processes herein described lead variously to acids (R 1 is hydrogen) or to esters.
When the alkyl ester has been obtained and an acid is desired, saponification procedures, as known in the art for PGF-type compounds are employed.
For alkyl esters of PGE-type compounds enzymatic processes for transformation of esters to their acid forms may be used by methods known in the art when saponification procedures would cause dehydration of the prostaglandin analog. See for reference E. G. Daniels, Process For Producing An Esterase, U.S. Pat. No. 3,761,356.
When an acid has been prepared and an alkyl, cycloalkyl, or aralkyl ester is desired, esterification is advantageously accomplished by interaction of the acid with the appropriate diazohydrocarbon. For example, when diazomethane is used, the methyl esters are produced. Similar use of diazoethane, diazobutane, and 1-diazo-2-ethylhexane, and diazodecane, for example, gives the ethyl, butyl, and 2-ethylhexyl and decyl esters, respectively. Similarly, diazocyclohexane and phenyldiazomethane yield cyclohexyl and benzyl esters, respectively.
Esterification with diazohydrocarbons in carried out by mixing a solution of the diazohydrocarbon is a suitable inert solvent, preferably diethyl ether, with the acid reactant, advantageously in the same or a different inert diluent. After the esterification reaction is complete the solvent is removed by evaporation, and the ester purified if desired by conventional methods, preferably by chromatography. It is preferred that contact of the acid reactants with the diazohydrocarbon be no longer than necessary to effect the desired esterification, preferably about one to about ten minutes, to avoid undesired molecular changes. Diazohydrocarbons are known in the art or can be prepared by methods known in the art. See, for example, Organic Reactions, John Wiley and Sons, Inc., New York, N. Y., Vol. 8, pp. 389-394 (1954).
An alternative method for alkyl, cycloalkyl or aralkyl esterification of the carboxy moiety of the acid compounds comprises transformation of the free acid to the corresponding silver salt, followed by interaction of that salt with an alkyl iodide. Examples of suitable iodides are methyl iodide, ethyl iodide, butyl iodide, isobutyl iodide, tert-butyl iodide, cyclopropyl iodide, cyclopentyl iodide, benzyl iodide, phenethyl iodide, and the like. The silver salts are prepared by conventional methods, for example, by dissolving the acid in cold dilute aqueous ammonia, evaporating the excess ammonia at reduced pressure, and then adding the stoichiometric amount of silver nitrate.
Various methods are available for preparing phenyl or substituted phenyl esters within the scope of the invention from corresponding aromatic alcohols and the free acid PG-type compounds, differing as to yield and purity of product.
Thus by one method, the PG-type compound is converted to a tertiary amine salt, reacted with pivaloyl halide to give the mixed acid anhydride and then reacted with the aromatic alcohol. Alternatively, instead of pivaloyl halide, and alkyl or arylsulfonyl halide is used, such as p-toluenesulfonyl chloride. See for example Belgian Pats. Nos. 775,106 and 776,294, Derwent Farmdoc Nos. 33705T and 39011T.
Still another method is by the use of the coupling reagent, dicyclohexylcarbodiimide. See Fieser et al., "Reagents for Organic Synthesis", pp. 231-236, John Wiley and Sons, Inc., New York, (1967). The PG-type compound is contacted with one to ten molar equivalents of the aromatic alcohol in the presence of 2-10 molar equivalents of dicyclohexylcarbodiimide in pyridine as a solvent.
One preferred novel process for the preparation of these esters, however, comprises the steps:
a. forming a mixed anhydride with the PG-type compound and isobutylchloroformate in the presence of a tertiary amine and
b. reacting the anhydride with an appropriate aromatic alcohol.
The mixed anhydride described above is formed readily at temperatures in the range -40° to +60° C., preferably at -10° to +10° C. so that the rate is reasonably fast and yet side reactions are minimized. The isobutylchloroformate reagent is preferably used in excess, for example 1.2 molar equivalents up to 4.0 per mole of the PG-type compound. The reaction is preferably done in a solvent and for this purpose acetone is preferred, although other relatively nonpolar solvents are used such as acetonitrile, dichloromethane, and chloroform. The reaction is run in the presence of a tertiary amine, for example triethylamine, and the co-formed amine hydrochloride usually crystallizes out, but need not be removed for the next step.
The aromatic alcohol is preferably used in equivalent amounts or in substantial stoichiometric excess to insure that all of the mixed anhydride is converted to ester. Excess aromatic alcohol is separated from the product by methods described herein or known in the art, for example by crystallization. The tertiary amine is not only a basic catalyst for the esterification but also a convenient solvent. Other examples of tertiary amines useful for this purpose include N-methylmorpholine, triethylamine, diisopropylethylamine, and dimethylaniline. Although they are effectively used, 2-methylpyridine and quinoline result in a slow reaction. A highly hindered amine such as 2,6-dimethyllutidine is, for example, not useful because of the slowness of the reaction.
The reaction with the anhydride proceeds smoothly at room temperature (about 20° to 30° C.) and can be followed in the conventional manner with thin layer chromatography (TLC).
The reaction mixture is worked up to yield the ester following methods known in the art, and the product is purified, for example by silica gel chromatography.
Solid esters are converted to a free-flowing crystalline form on crystallization from a variety of solvents, including ethyl acetate, tetrahydrofuran, methanol, and acetone, by cooling or evaporating a saturated solution of the ester in the solvent or by adding a miscible nonsolvent such as diethyl ether, hexane, or water. The crystals are then collected by conventional techniques, e.g. filtration or centrifugation, washed with a small amount of solvent, and dried under reduced pressure. They may also be dried in a current of warm nitrogen or argon, or by warming to about 75° C. Although the crystals are normally pure enough for many applications, they may be recrystallized by the same general techniques to achieve improved purity after each recrystallization.
The compounds of this invention prepared by the processes of this invention, in free acid form, are transformed to pharmacologically acceptable salts by neutralization with appropriate amounts of the corresponding inorganic or organic base, examples of which correspond to the cations and amines listed hereinabove. These transformations are carried out by a variety of procedures known in the art to be generally useful for the preparation of inorganic, i.e., metal or ammonium salts. The choice of procedure depends in part upon the solubility characteristics of the particular salt to be prepared. In the case of the inorganic salts, it is usually suitable to dissolve an acid of this invention in water containing the stoichiometric amount of a hydroxide, carbonate, or bicarbonate corresponding to the inorganic salt desired. For example, such use of sodium hydroxide, sodium carbonate, or sodium bicarbonate gives a solution of the sodium salt. Evaporation of the water or addition of a water-miscible solvent of moderate polarity, for example, a lower alkanol or a lower alkanone, gives the solid inorganic salt if that form is desired.
To produce an amine salt, an acid of this invention is dissolved in a suitable solvent of either moderate or low polarity. Examples of the former are ethanol, acetone, and ethyl acetate. Examples of the latter are diethyl ether and benzene. At least a stoichiometric amount of the amine corresponding to the desired cation is then added to that solution. If the resulting salt does not precipitate, it is usually obtained in solid form by addition of a miscible dilutne of low polarity or by evaporation. If the amine is relatively volatile, any excess can easily be removed by evaporation. It is preferred to use stoichiometric amounts of the less volatile amines.
Salts wherein the cation is quaternary ammonium are produced by mixing an acid of this invention with the stoichiometric amount of the corresponding quaternary ammonium hydroxide in water solution, followed by evaporation of the water.
The acids or esters of this invention prepared by the processes of this invention are transformed to lower alkanoates by interaction of a free hydroxy compound with a carboxyacylating agent, preferably the anhydride of a lower alkanoic acid, i.e., an alkanoic acid of two to 8 carbon atoms, inclusive. For example, use of acetic anhydride gives the corresponding acetate. Similar use of propionic anhydride, isobutyric anhydride, or hexanoic anhydride gives the corresponding carboxyacylate.
The carboxyacylation is advantageously carried out by mixing the hydroxy compound and the acid anhydride, preferably in the presence of a tertiary amine such as pyridine or triethylamine. A substantial excess of the anhydride is used, preferably about 10 to about 10,000 moles of anhydride per mole of the hydroxy compound reactant. The excess anhydride serves as a reaction diluent and solvent.
An inert organic diluent, (e.g., dioxane) can also be added. It is preferred to use enough of the tertiary amine to neutralize the carboxylic acid produced by the reaction, as well as any free carboxyl groups present in the hydroxy compound reactant.
The caboxyacylation reaction is preferably carried out in the range about 0° to about 100° C. The necessary reaction time will depend on such factors as the reaction temperature, and the nature of the anhydride and tertiary amine reactants. With acetic anhydride, pyridine, and a 25° C. reaction temperature, a 12 to 24 hour reaction time is used.
The carboxyacylated product is isolated from the reaction mixture by conventional methods. For example, the excess anhydride is decomposed with water, and the resulting mixture acidified and then extracted with a solvent such as diethyl ether. The desired carboxyacylate is recovered from the diethyl ether extract by evaporation. The carboxyacylate is then purified by conventional methods, advantageously by chromatography or crystallization.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention can be more fully understood by the following examples and preparations.
All temperatures are in degrees centigrade.
IR (infrared) absorption spectra are recorded on a Perkin-Elmer Model 421 infrared spectrophotometer. Except when specified otherwise, undiluted (neat) samples are used.
UV (Ultraviolet) spectra are recorded on a Cary Model 15 spectrophotometer.
NMR (Nuclear Magnetic Resonance) spectra are recorded on a Varian A-60, A-60D, and T-60 spectrophotometer on deuterochloroform solutions with tetramethylsilane as an internal standard (downfield).
Mass spectra are recorded on an CEC model 21-110B Double Focusing High Resolution Mass Spectrometer on an LKB Model 9000 Gas-Chromatograph-Mass Spectrometer. Trimethylsilyl derivatives are used, except where otherwise indicated.
The collection of chromatographic eluate fractions starts when the eluant front reaches the bottom of the column.
"Brine", herein, refers to an aqueous saturated sodium chloride solution.
The A-1X solvent system used in thin layer chromatography is made up from ethyl acetate-acetic acidcyclohexane-water (90:10:50:100) as modified from M. Hamberg and B. Samuelsson, J. Biol. Chem. 241, 257 (1966).
Skellysilve-B (SSB) refers to mixed isomeric hexanes.
Silica gel chromatography, as used herein, is understood to include elution, collection of fractions, and combination of those fractions shown by TLC (thin layer chromatography) to contain the pure product (i.e., free of starting material and impurities).
Melting points (MP) are determined on a Fisher-Johns or Thomas-Hoover melting point apparatus.
DDQ refers to 2,3-dichloro-5,6-dicyano-1,4-benzoquinone. THF refers to tetrahydrofuran. Specific Rotations, [α], are determined for solutions of a compound in the specified solvent at ambient temperature with a Perkin-Elmer Model 141 Automatic Polarimeter.
EXAMPLE 1
Dimethyl 3,3-dimethyl-2-oxo-4-phenylbutylphosphonate, ##STR123##
A. To a solution of 101.2 g. of diisopropylamine in 125 ml. of tetrahydrofuran under nitrogen at 0° is added dropwise with cooling (using an ice-methanol bath) 625 ml. of 1.6M n-butyllithium in hexane. To the resulting solution is added dropwise with cooling 46.5 ml. of isobutyric acid. This mixture is then stirred at 0° C. for 90 min. and thereafter cooled to -15° C. Benzyl chloride (60 ml.) is added with stirring at such a rate as to maintain the reaction temperature below -5° C. The resulting mixture is thereafter stirred at ambient temperature for 4 hours. This stirred mixture is then diluted with diethyl ether and excess cold dilute hydrochloric acid. The organic layer is washed with saline and thereafter dried, concentrated, and the residue distilled under vacuum. Accordingly, there is prepared 2,2-dimethyl-3-phenyl propionic acid.
B. A mixture of 48 g. of the product of part A of this example and 82 g. of thionyl chloride are heated with stirring on a steam bath for 2 hours. The mixture is then concentrated under vacuum. Thereafter dry benzene is added and the resulting mixture is concentrated again, removing all traces of thionyl chloride. Distillation of this residue yields 48.2 g. of 2,2-dimethyl-3-phenyl-propionyl chloride.
C. To a solution of 63 g. of dimethylmethylphosphonate in 600 ml. of tetrahydrofuran under nitrogen at -75° C. is added with stirring 312 ml. of 1.6 molar n-butyllithium in hexane. The addition rate is adjusted so that the reaction temperature remains below 55° C. Ten minutes after the addition is complete, 48.2 g. of the reaction product of part B of this example and 50 ml. of tetrahydrofuran are added dropwise at such rate as to maintain the reaction temperature below -60° C. The resulting mixture is then stirred at -75° C. for 2 hours and then ambient temperature overnight. Acetic acid (20 ml.) is thereafter added and the resulting mixture distilled under vacuum, thereby removing most of the tetrahydrofuran. The residue is then shaken with diethyl ether in methylene chloride (3:1 by volume) and a cold dilute sodium bicarbonate solution. The organic layer is then washed with brine, dried, and concentrated. The residue was crystallized from diethyl ether, yielding 54 g. of dimethyl 3,3-dimethyl-2-oxo-4-phenylbutylphosphonate the title compound. The melting point is 48° -50° C.
Following the procedure of Example 1, but using in place of benzyl chloride substituted benzyl chlorides of the formula ##STR124## wherein T is fluoro, chloro, trifluoromethyl, alkyl of one to 3 carbon atoms, inclusive, or alkoxy of one to 3 carbon atoms, inclusive, and wherein s is zero, one, 2, or 3, with the proviso that not more than two T's are other than alkyl, and with the further proviso that the various T's may be the same or different, there are prepared the corresponding dimethyl-3,3-dimethyl-2-oxo-4-(substituted phenyl)butylphosphonates. For example, there is prepared by this procedure dimethyl 3,3-dimethyl-2-oxo-4-(p-fluorophenyl)-butylphosphonate.
Further, following the procedure of Example 1, but using in place of the isobutyric acid of Example 1, part A, propionic acid, there is prepared dimethyl 3-methyl-2-oxo-4-phenylbutylphosphonate. Following the procedure of Example 1, but using the substituted benzyl chlorides described above in place of benzyl chloride and propionic acid in place of isobutyric acid there are prepared the various dimethyl 3-methyl-2-oxo-4-(substituted phenyl)butylphosphonates wherein the phenyl substitution is as described above.
Further, following the procedure of Example 1, but using acetic acid in place of isobutyric acid as used in Example 1, part A, there is prepared dimethyl-2-oxo-4-phenylbutylphosphonate. Using acetic acid in combination with the various substituted benzyl chlorides described above according to the procedure of Example 1, there are prepared the various dimethyl 2-oxo-4-(substitutedphenyl)-butyl phosphonates, wherein the phenyl substitution is as described above.
Following the procedure of Example 1, but using 2,2-difluoroacetic acid in place of isobutyric acid as used in part A of Example 1, there is prepared dimethyl 3,3-difluoro-2-oxo-4-phenylbutylphosphonate. Further, following the procedure of Example 1, but using 2,2-difluoro acetic acid in combination with substituted benzyl chlorides described above, there are prepared the corresponding dimethyl 3,3-difluoro-2-oxo-4-(substituted)phenylbutylphosphonate, wherein the phenyl substitution is as described above.
Further, following the procedure of Example 1, but using 2-fluoro acetic acid in place of isobutyric acid there is prepared dimethyl 3-fluoro-2-oxo-4-phenylbutylphosphonate.
Using 2-fluoro acetic acid and the various substituted benzyl chlorides described above according to the procedure of Example 1, there are prepared the various dimethyl 3-fluoro-2-oxo-4-(substituted)phenylbutyl phosphonates, wherein the phenyl substitution is as described above.
EXAMPLE 2
Triphenylphosphonium salt of 2,2-difluoro-5-bromopentanoic acid, Br(C 6 H 5 ) 3 P-(CH 2 ) 3 --CF 2 --COOH.
A. Methyl furoate (50.4 g.) is dissolved in 180 ml. of methanol. Thereafter 1 g. of 5 percent palladium-on-charcoal is added. This mixture is then hydrogenated at 1 to 3 atmospheres. After 45 hours 0.79 moles of hydrogen are consumed. The black mixture is then filtered through Celite using 50 ml. of methanol to wash the reaction flask and filter. Evaporation of the filtrate under reduced pressure at 40°-45° C. bath temperature yields 51 g. of a yellow oil which is thereafter distilled, collecting that fraction boiling at 32°-35° C. Thereby, methyl tetrahydrofuroate (46.7 g.) is prepared.
B. Anhydrous hydrobromic acid is bubbled through 50 ml. of acetic anhydride with cooling until a specific gravity of 1.3 is obtained. This reagent is then added to 25 g. of the reaction product of step A of this example, with exclusion of moisture while cooling and stirring. Stirring in the ice water bath is continued for 15 min.; thereafter, the mixture is allowed to stand at room temperature overnight. The reaction mixture is then poured into 600 g. of crushed ice and water with stirring and extracted with diethyl ether. The ether extract is washed with aqueous sodium hydroxide, dried over sodium sulfate, filtered, and thereafter evaporated under reduced pressure to yield 38 g. of a pale yellow oil, which is thereafter distilled under high vacuum, yielding 31.6 g. of methyl 2-acetoxy-5-bromopentanoate.
C. To a solution of 60 g. of the reaction product of part B of this example in 200 ml. of methanol is added 100 ml. of methanol, which is saturated with hydrobromic acid at 0° C. and 1.3 specific gravity before the addition. The reaction mixture is then allowed to stand at room temperature overnight. The solvent is thereafter evaporated under reduced pressure at 35° C. bath temperature and 400 ml. of toluene is thereafter added. The solvent is again evaporated. This residue is then dissolved in 2 l. of ethyl acetate, washed with 5 percent aqueous sodium hydroxide solution and sodium chloride solution before being dried over sodium sulfate. Filtration and evaporation of the solvent under reduced pressure at 45° C. yields 42 g. of oil which is distilled under high vacuum, yielding 28.8 g. of methyl 2-hydroxy5-bromopentanoate.
D. To a solution of 34.4 g. of the reaction product of part C of this example and 400 ml. of acetone is added with stirring and cooling 75 ml. of Jones reagent (26.73 g. of CrO 3 in 23 ml. of concentrated sulfuric acid, diluted to 100 ml. with water) at such a rate that the reaction temperature is maintained between 30° and 40° C. The reaction is complete in approximately 20 min. Thereafter the reaction mixture is stirred for 1.5 hr. Thereafter 150 ml. of isopropyl alcohol are slowly added with stirring during 30 min. The reaction mixtureis then diluted with 1.8 l. of water and extracted with 2.4 l. of methylene chloride. These extracts are washed with brine and dried with sodium sulfate. Filtration and evaporation of the solvent under reduced pressure yields 30.8 g. of a pale yellow oil, containing methyl 2-oxo-5-bromopentanoate. This oil is used in the following steps of this example without further purification.
E. With the exclusion of moisture under a nitrogen atmosphere 195 ml. of MoF 6 .sup.. BF 3 is cooled in a dry-ice acetone bath. A solution of 30.8 g. of the reaction product of step D of this example and 40 ml. of methylene chloride is added dropwise with stirring over a period of 15 min. The reaction temperature is maintained between -35 and -45° C. Stirring the dry ice acetone bath is continued for 1 hour, the cooling bath thereafter is removed, and the reaction mixture thereafter diluted with 200 ml. of methylene chloride and 400 ml. of water. The organic and aqueous layers are separated, the aqueous layer being extracted with methylene chloride and the combined methylene chloride extracts washed with 250 ml. of water, 250 ml. of 5 percent aqueous potassium bicarbonate, 250 ml. of brine, and thereafter dried over sodium sulfate. Filtration and evaporation of the solvent yields 31.1 g. of a dark brown oil, which when distilled under high vacuum yields methyl 2,2-difluoro-5-bromopentanoate (14 g.).
F. The reaction product of part E of this example (28 g.) is stirred in 175 ml. of aqueous hydrobromic acid (specific gravity 1.71) for 3 hours at room temperature. The reaction mixture is then cooled in an ice bath, and diluted with 1300 ml. of diethyl ether. The organic and aqueous layers are separated and the aqueous layer is extracted with diethyl ether. The combined etheral solutions are washed with water and the ethereal loss solutions are backwashed with 400 ml. of ether and the combined ethereal solutions is then dried over sodium sulfate. Filtration and evaporation of the solvent yields 27.7 g. of a pale yellow oil, 2,2-difluoro-5-bromopentanoic acid, which is used in the following step of this example without further purification.
G. A mixture of 15.2 g. of the reaction product of part F of this example, 80 ml. of acetonitrile and 22 g. of triphenylphosphine are heated to reflux with stirring for 30 hours. The reaction mixture is then heated to 110° C., diluted with 160 ml. of toluene, and the mixture is allowed to cool slowly at room temperature for 12 hours with stirring. The reaction mixture is then stored at 5° C. for 24 hours. A precipitate is collected, washed with 50 ml. of toluene, and dried under vacuum at room temperature. 20.9 g. of the title compound of this example is thereby obtained.
EXAMPLE 3
(6-Carboxyhexyl)triphenylphosphonium bromide
A mixture of 63.6 g. of 7-bromoheptanoic acid, 80 g. of triphenylphosphine, and 30 ml. of acetonitrile, is refluxed for 68 hours. Thereafter 200 ml. of acetonitrile is removed by distillation. After the remaining solution is cooled to room temperature, 30 ml. of benzene is added with stirring. The mixture is then allowed to stand for 12 hours. A solid separates which is collected by filtration, yielding 134.1 g. of product, melting point 185°-187° C.
Following the procedure of Example 3, but using 3-bromopropionic acid, 4-bromobutanoic acid, 5-bromopentanoic acid, or 6-bromohexanoic acid, in place of 7-bromoheptanoic acid, there are prepared the corresponding (ω-carboxyalkyl)-triphenylphosphonium bromides.
EXAMPLE 4
3α-Benzoyloxy-5α-hydroxy-2β-(2-chloro-3-oxo-4,4-dimethyl-trans-1-octenyl)-1α-cyclopentaneacetic acid, γ lactone (Formula XXIII: R 7 is n-butyl, R 16 is benzoyloxy, R 3 and R 4 of the L 1 moiety are methyl, and Y 2 is trans-CH=C(Cl)-).
Refer to Chart A.
A. A solution of 24.3 g. of thallous ethoxide in 125 ml. of dry benzene is cooled in an ice bath, and thereafter a solution of 25.3 g. of methyl 3,3-dimethyl-2-oxo-heptylphosphonate in 75 ml. of benzene is added and thereafter rinsed with 50 ml. of benzene. The solution is stirred for 30 min. at 5° C. and thereafter 22.1 g. of crystalline 3α-benzoyloxy-5α-hydroxy-2β-carboxaldehyde- 1α-cyclopentaneacetic acid, γ lactone is added rapidly. This reaction mixture is then stirred for 13 hours at ambient temperature yielding a brown solution of pH 9-10. Acetic acid (6ml.) is added and the mixture is transferred to a beaker with 600 ml. of diethyl ether. Celite and 500 ml. of water is added, followed by the addition of 30 ml. (about 33 g.) of saturated potassium iodide. The mixture (containing a bright yellow precipitate of thallous iodide) is stirred for about 45 min., and thereafter filtered through a bed of Celite. The organic layer is then washed with water, aqueous potassium bicarbonate, and brine. Thereafter the resulting mixture is dried over magnesium sulfate and evaporated at reduced pressure, yielding 33.6 g. of an oil, which is then chromatographed on 600 g. of silica gel packed in 20 percent ethyl acetate in cyclohexane. Elution, collecting 500 ml. fractions, with 2 l. of 20 percent, 2 l. of 25 percent, and 4 l. of 30 percent ethyl acetate in cyclohexane yields 20.3 g. of crude product, which upon recrystallization from 240 ml. of diethyl ether in pentane (2:1) yields 3α-benzoyloxy-5α-hydroxy-2β-(3-oxo-4,4-dimethyl-trans-1-octenyl)-1α-cyclopenaneacetic acid, γ lactone.
Alternatively this product is prepared by adding 3α-benzoyloxy-2β-carboxaldehyde-5α-hydroxy-1α-cyclopentaneacetic acid γ lactone (3 g.) in 30 ml. of dichloromethane to a solution of dimethyl-1-chloro-2-oxo-3,3-dimethylheptylphosphonate (6.69 g.) and sodium hydride (1.35 g.) in 15 ml. of tetrahydrofuran. The resulting reaction mixture is then stirred for 2 hours at about 25° C., acidified with acetic acid, and concentrated under reduced pressure. The residue is partitioned between dichloromethane and water, and the organic phase is concentrated. The residue is chromatographed on silica gel, eluting with ethyl acetate in Skellysolve B (1:1).
B. A solution of the reaction product of part A of this example (1.15 g.) in dioxane (35 ml.) is treated with N-chlorosuccinimide (9.7 g.) and stirred for 6 days. The resulting solution is then diluted with methylene chloride, washed with saline and a sodium sulfate solution, dried, and evaporated to yield a viscous residue. The residue in benzene is subjected to silica gel chromatography, eluting with hexane and ethyl acetate (9:1) whereupon pure 3α-benzoyloxy-5α-hydroxy-2β-(1,2-dichloro-3-oxo-4,4-dimethyloctyl)-1α-cyclopentaneacetic acid γ lactone is recovered (as a mixture of isomers). Thereafter the dichlorides so obtained are diluted with pyridine (20 ml.) and heated at 100° C. for 4.5 hours. The resulting solution is then diluted with diethyl ether and washed with ice cold dilute hydrochloric acid and brine. The resulting mixture is then dried and subject to silica gel chromatography, eluting with hexane and ethyl acetate (9:1 ), yielding 0.765 g. of pure product. NMR absorptions are observed at 0.85, 1.22, 1.0-1.9, 1.9-3.5, 4.8-5.1, 5.35, 6.28, 7.2-7.6, and 7.8-8.1 δ. The mass spectrum shows peaks at 432, 396, 376, 378, 254, and 256.
Alternatively, the reaction product of part A above (0.190 g.) in dry pyridine (5 ml.) at 0° C. is treated with freshly distilled sulfuryl chloride (0.386 g.) and the reaction is maintained for 5 hours. Thereafter additional sulfuryl chloride (0.667 g.) and pyridine (5 ml.) is added and the reaction continued for 12 hours for ambient temperature. A resulting dark solution is then diluted with methylene chloride, washed with ice cold phosphoric acid, sodium bicarbonate, dried, and evaporated. The residue is chromatographed on silica gel eluting with hexane and ethyl acetate (9:1). Pure product identical with that recovered in the preceding paragraph is obtained.
Following the procedure of Example 4, but using in place of 3α-benzoyloxy-5α-hydroxy-2β-carboxaldehyde-1α-cyclopentaneacetic acid γ lactone; 5α-hydroxy-2β-carboxaldehyde-1α-cyclopentaneacetic acid γ lactone, there is obtained 5α-hydroxy-2β-(2-chloro-3-oxo-4,4-dimethyl-trans-1-octenyl)-1.alpha.-cyclopentaneacetic acid γ lactone.
Further, following the procedure of Example 4, but using in place of dimethyl 2-oxo-3,3-dimethylheptylphosphonate, any of the various dimethyl phosphonates described hereinabove there are prepared the corresponding 3α-benzoyloxy-5α-hydroxy-1α-cyclopentaneacetic acid γ lactones or 5α-hydroxy-1α-cyclopentane-acetic acid γ lactones with a 2β-(2-chloro-3-oxo-trans-1-alkenyl)-substituent, optionally substituted, as follows:
4,4-difluorohexenyl; 4,4-difluoroheptenyl; 4,4-difluorooctenyl; 4,4-difluorononenyl; 4,4-difluorodecenyl; 4-fluorohexenyl; 4-fluoroheptenyl; 4-fluorooctenyl; 4-fluorononenyl; 4-fluorodecenyl; 4,4-dimethylhexenyl; 4,4-dimethylheptenyl; 4,4-dimethylnonenyl; 4,4-dimethyldecenyl; 4-methylhexenyl; 4-methylheptenyl; 4-methyloctenyl; 4-methylnonenyl; 4-methyldecenyl; hexenyl; heptenyl; octenyl; nonenyl; decenyl; 5-phenylpentenyl; 5-(m-trifluoromethylphenyl)-pentenyl; 5-(m-fluorophenyl)-pentenyl; 5-(m-chlorophenyl)-pentenyl; 5-(p-trifluoromethylphenyl)-pentenyl; 5-(p-fluorophenyl)-pentenyl; 5-(p-chlorophenyl)-pentenyl; 4-methyl-5-phenylpentenyl; 4-methyl-5-(m-trifluoromethylphenyl)pentenyl; 4-methyl-5-(m-fluorophenyl)-pentenyl; 4-methyl-5-(p-trifluoromethylphenyl)-pentenyl; 4-methyl-5-(p-fluorophenyl)-pentenyl; 4-methyl-5-(p-chlorophenyl)-pentenyl; 4,4-dimethyl-5-(m-trifluoromethylphenyl)-pentenyl; 4,4-dimethyl-5-(m-fluorophenyl)-pentenyl; 4,4-difluoro-5-(m-chlorophenyl)-pentenyl; 4,4-dimethyl-5-(p-trifluoromethylphenyl)-pentenyl; 4,4-dimethyl-5-(p-fluorophenyl)-pentenyl; 4,4-dimethyl-5-(p-chlorophenyl)-pentenyl; 4-fluoro-5-phenylpentenyl; 4-fluoro-5-(m-trifluoromethylphenyl)-pentenyl; 4-fluoro-5-(m-fluorophenyl)-pentenyl; 4-fluoro-5-(m-chlorophenyl)-pentenyl; 4-fluoro-5(p-trifluoromethylphenyl)-pentenyl 4-fluoro-5-(p-fluorophenyl)-pentenyl; 4-fluoro-5-(p-chlorophenyl)-pentenyl; 4,4-difluoro-5-phenylpentenyl; 4,4-difluoro-5-(m-trifluoromethylphenyl)-pentenyl; 4,4-difluoro-5-(m-fluorophenyl)-pentenyl; 4,4-difluoro-5-(m-chlorophenyl)-pentenyl; 4,4-difluoro-5-(p-trifluoromethylphenyl)-pentenyl; 4,4-difluoro-5-(p-fluorophenyl)-pentenyl; 4,4-difluoro-5-(p-chlorophenyl)-pentenyl; 4-phenoxybutenyl; 4-(m-trifluoromethylphenoxy)-butenyl; 4-(p-fluorophenoxy)-butenyl; 4-(m-chlorophenoxy)-butenyl; 4-(m-trifluoromethylphenoxy)-butenyl; 4-(p-fluorophenoxy)-butenyl; 4-(p-chlorophenoxy)-butenyl; 4-methyl-4-phenoxybutenyl; 4-methyl-4-(m-trifluoromethoxyphenoxy)-butenyl; 4-methyl-4-(m-fluorophenoxy)-butenyl; 4-methyl-4-(m-chlorophenoxy)-butenyl; 4-methyl-4-(p-trifluoromethylphenoxy)-butenyl; 4-methyl-4-(p-fluorophenoxy)-butenyl; 4-methyl-4-(p-chlorophenoxy)-butenyl; 4,4-dimethyl-4-phenoxybutenyl; 4,4-dimethyl-4-(trifluoromethylphenoxy)-butenyl; 4,4-di-methyl-4-(m-fluorophenoxy)-butenyl; 4,4-dimethyl-4-(m-chlorophenoxy)-butenyl; 4,4-dimethyl-4-(p-trifluoromethylphenoxy)-butenyl; 4,4-dimethyl-4-(p-fluorophenoxy)-butenyl; 4,4-dimethyl-4-(p-chlorophenoxy)-butenyl; and the like.
PGF.sub.α, PGE, PGF.sub.β, PGA, and PGB analogs described herein are prepared from the formula XXIII compound wherein the C-3 position of the cyclopentane ring is substituted by a benzoyloxy moiety at C-3, as described above (Example 4).
Likewise, intermediates useful in preparing 11-deoxy-PGF.sub.α, 11-deoxy-PGE, and 11-deoxy-PGF.sub.β-type compounds of these disclosed are prepared as described above in and following Example 4 except the starting material employed is a 3-unsubstituted lactone; that is 5α-hydroxy-2β-carboxaldehyde-1α-cyclopentaneacetic acid γ lactone Accordingly there are prepared 5α-hydroxy-1α-cyclopentaneacetic acid γ lactones with the various 2β-side chains described following Example 4 which are useful in the same manner as the 3α-benzoyloxy compounds in the procedures of succeeding examples for preparing the 11-deoxy-PGF.sub.α-, PGE-, or PGF.sub.β-type compounds corresponding to the PGF.sub.α-, PGE-, and PGF.sub.β-type compounds therein prepared.
EXAMPLE 5
3α-Benzoyloxy-5α-hydroxy-2β-[2-chloro-(3R)-3-hydroxy-4,4-dimethyl-trans-1-octenyl]-1α-cyclopentaneacetic acid γ lactone (Formula XXIV: R 3 and R 4 of the L 1 moiety are methyl, R 5 and R 6 of the M 5 moiety are hydrogen, R 7 is n-pentyl, R 16 is benzoyloxy, and Y 2 is trans-CH=C(Cl) or its (3S)-hydroxy epimer.
Sodium borohydride (0.92 g.) is slowly added to a stirred suspension of 2.1 g. of anhydrous zinc chloride in 45 ml. of dimethyl ether in ethylene glycol (glyme) with ice bath cooling. The mixture is stirred for 20 hours at ambient temperature and thereafter cooled to -18° C. A solution of 0.76 g. of 3α-benzoyloxy-5α-hydroxy-2β-(2-chloro-3-oxo-4,4-dimethyl-trans-1-octenyl)-1α-cyclopentaneacetic acid γ lactone (prepared according to Example 4) in 12 ml. of glyme is added over a period of 20 minutes. Stirring is continued for 24 hours at -20° C. and thereafter 40 ml. of water is cautiously added. The reaction mixture is warmed to room temperature, diluted with ethyl acetate, and washed twice with brine. The aqueous layers are extracted with ethyl acetate. The combined organic extracts are dried over sodium sulfate and evaporated to yield crude product, which when chromatographed on 12 g. of silica gel eluting with hexane and in ethyl acetate (3:1) yields the epimerically pure title product.
The 3R epimer exhibits ultraviolet absorptions at λ max . equals 229.5 nm. (ε 13,550). The mass spectrum shows absorption at 337, 336, 335, 217, 216, 215, 214, and 213. NMR absorptions in CDCl 3 are observed at 0.85, 0.90, 0.80-1.0, 1.0-1.5, 1.9-3.0, 3.0-3.6, 4.0, 4.7-5.5, 5.65, 7.2-7.7, and 7.8-8.2 δ.
The 3S epimer exhibits NMR absorptions in CDCl 3 at 0.86, 0.90, 0.8-1.0, 1.0-1.5, 2.1-3.0, 3.0-3.8, 4.0, 7.1-7.7, and 7.8-8.2 δ.
Following the procedure of Example 5, but using in place of the 3α-benzoyloxy-5α-hydroxy-2β-(2-chloro-3-oxo-4,4-dimethyl-trans-1-octenyl)-1α-cyclopentaneacetic acid γ lactone starting material employed therein, the various 3α-benzoyloxy-5α-hydroxy-2β-(2-chloro-3-oxo-trans-1-alkenyl, trans-1-cis-5-alkadienyl, or substituted alkenyl or alkadienyl)-1α-cyclopentaneacetic acid γ lactones there are prepared the corresponding 3R or 3S hydroxy products.
Following the procedure of Example 5, but using in place of the 3α-benzoyloxy-5α-hydroxy-2β-(2-chloro-3-oxo-4,4-dimethyl-trans-1-octenyl)-1α-cyclopentaneacetic acid γ lactone used therein, 5α-hydroxy-2β-(2-chloro-3-oxo-trans-1-alkenyl, trans-1-cis-5-alkadienyl, or substituted alkenyl or alkadienyl)-1α-cyclopentaneacetic acid γ lactones described following Example 4, there are prepared the corresponding 3R or 3S-hydroxy products. For example, there are obtained the above 3α-benzoyloxy-5α-hydroxy- or 5α-hydroxy-1α-cyclopentaneacetic acid γ lactones wherein the 2β-side chain in either the 3R or 3S form consists of
2-chloro-3-hydroxy-trans-1-hexenyl;
2-chloro-3-hydroxy-trans-1-heptenyl;
2-chloro-3-hydroxy-trans-1-octenyl;
2-chloro-3-hydroxy-trans-1-nonenyl;
2-chloro-3-hydroxy-trans-1-decenyl;
2-chloro-3-hydroxy-4-methyl-trans-1-octenyl;
2-chloro-3-hydroxy-4-fluoro-trans-1-octenyl;
2-chloro-3-hydroxy-4,4-difluoro-trans-1-octenyl;
2-chloro-3-hydroxy-5-phenyl-trans-1-pentenyl;
2-chloro-3-hydroxy-5-(p-fluorophenyl)-trans-1-pentenyl;
2-chloro-3-hydroxy-5-(m-chlorophenyl)-trans-1-pentenyl;
2-chloro-3-hydroxy-5-(m-trifluoromethylphenyl)-trans-1-pentenyl;
2-chloro-3-hydroxy-4,4-dimethyl-5-phenyl-trans-1-pentenyl;
2-chloro-3-hydroxy-4,4-dimethyl-5-(p-fluorophenyl)-trans-1-pentenyl;
2-chloro-3-hydroxy-4,4-dimethyl-5-(m-chlorophenyl)-trans-1-pentenyl;
2-chloro-3-hydroxy-4,4-dimethyl-5-(m-trifluoromethylphenyl)-trans-1-pentenyl;
2-chloro-3-hydroxy-4,4-difluoro-5-phenyl-trans-1-pentenyl;
2-chloro-3-hydroxy-4,4-difluoro-5-(p-fluorophenyl)-trans-1-pentenyl;
2-chloro-3-hydroxy-4,4-difluoro-5-(m-chlorophenyl)-trans-1-pentenyl;
2-chloro-3-hydroxy-4,4-difluoro-5-(m-trifluoromethylphenyl)-trans-1-pentenyl;
2-chloro-3-hydroxy-4-phenoxy-trans-1-butenyl;
2-chloro-3-hydroxy-4-(p-fluorophenoxy)-trans-1-butenyl;
2-chloro-3-hydroxy-4-(m-chlorophenoxy)-trans-1-butenyl;
2-chloro-3-hydroxy-4-(m-trifluoromethylphenoxy)-trans-1-butenyl;
2-chloro-3-hydroxy-4,4-dimethyl-4-phenoxy-trans-1-butenyl;
2-chloro-3-hydroxy-4,4-dimethyl-4-(p-fluorophenoxy)-trans-1-butenyl;
2-chloro-3-hydroxy-4,4-dimethyl-4-(m-chlorophenoxy)-trans-1-butenyl;
2-chloro-3-hydroxy-4,4-dimethyl-4-(m-trifluoromethylphenoxy)-trans-1-butenyl; and the like.
EXAMPLE 6
3α-Benzoyloxy-5α-hydroxy-2β-[2-chloro-(3R)-3-methoxy-4,4-dimethyl-trans-1-octenyl]-1α-cyclopentaneacetic acid γ lactone (Formula XXIV: R 3 and R 4 of the L 1 moiety are methyl, M 5 is ##STR125## R 7 is n-pentyl, R 16 is benzoyloxy, and Y is trans-CH=C(Cl)-) or its (3S) epimer.
Refer to Chart A. A mixture of the (3R) or (3S) reaction product of Example 5 (3.6 g.), silver oxide (4.0 g.) in 50 ml. of methyl iodide and 150 ml. of benzene is stirred and heated at reflux for 18 hours. The resulting mixture is then cooled and filtered and the filtrate concentrated. The resulting concentrate is then subjected to silica gel chromatography, and those fractions as shown by thin layer chromatography to contain pure title compound are combined, yielding respectively the 3R or 3S epimer.
For 3R epimer NMR absorptions are observed at 3.21, 3.8-4.2, 4.9-5.6, 7.25-7.7, and 7.9-8.2 δ.
Following the procedure of Example 6, but using in place of the lactone starting material therein, the various 3-hydroxy lactones described following Example 5, there are prepared the corresponding 3-methoxy products.
EXAMPLE 7
3α-Benzoyloxy-5α-hydroxy-2β-[2-chloro-(3S)-3-hydroxy-3-methyl-trans-1-octenyl]-1α-cyclopentaneacetic acid γ lactone (Formula XXIV as in Example 6 except M 5 is ##STR126##
Refer to Chart A.
A solution of 18 g. of 3α-benzoyloxy-5α-hydroxy-2β-(2-chloro-3-oxo-trans-1-octenyl)-1α-cyclopentaneacetic acid γ lactone in 890 ml. of dry benzene is cooled to 9° C. under a nitrogen atmosphere. A toluene solution of trimethyl-aluminum (60 ml.) is added over a period of 4 min. to the resulting mixture. This mixture is then stirred for 1.5 hours at 20°-25° C. then cooled to 10° C. Thereupon 370 ml. of saturated ammonium chloride is slowly added at such a rate so as to maintain the reaction mixture at ambient temperature. After 0.5 hours the reaction mixture is diluted with ethyl acetate and water and filtered, the filter cake being washed with the ethyl acetate-water solvent. The aqueous layer is extracted with ethyl acetate and the combined organic extracts are washed with brine, dried over magnesium sulfate, and evaporated to yield crude product, which is chromatographed on one kg. of silica gel packed in 10 percent ethyl acetate and Skellysolve B. Elution with 10 to 16 percent ethyl acetate in Skellysolve B (18 l.), 28 percent ethyl acetate in Skellysolve B (8 l.) yields pure title compound or pure (3R)-epimer.
Omitting the chromatographic separation described above, the (3RS)-epimeric mixture obtained on trimethyl-aluminum alkylation are separated in high yield as prostaglandin-type products.
Following the procedure of Example 7, but using in place of the 2-chloro-3-oxo lactone starting material therein, the various lactones described following Example 4, there are obtained 2-chloro-3-hydroxy-3-methyl products corresponding to each of the 2-chloro-3-hydroxy products of Example 5.
EXAMPLE 8
3α,5α-dihydroxy-2β-[2-chloro-(3R)-3-hydroxy-4,4-dimethyl-trans-1-octenyl]-1α-cyclopentaneacetaldehyde, γ lactol, bis-tetrahydropyranyl ether (Formula XXVII: R 3 and R 4 of the L 1 moiety are methyl, M 6 is ##STR127## R 7 is n-butyl, R 18 is tetrahydropyran-2-yloxy, and Y 2 is trans-CH=C(Cl)--) and its (3S)-epimer.
Refer to Chart A.
A. A solution of 100 mg. of the reaction product of Example 5 in 20 ml. of methanol is purged with nitrogen. Thereafter, potassium carbonate (30 mg.) is added and the resulting mixture is stirred at ambient temperature until thin layer chromatographic analysis shows the solvolysis to be complete (about 12 hours). The solution is then diluted with ice water and neutralized with cold, dilute phosphoric acid. The resulting mixture is then dried and evaporated under reduced pressure. The residue is then chromatographed using silica gel eluting with hexane and ethylacetate (3:2). Accordingly, 40 mg. of the deacylated lactone are prepared. NMR absorptions are observed at 0.92, 0.95, 1.1-1.6, 2.0-3.3, 4.8-5.2, 5.57, and 5.66 δ.
B. A solution of 0.39 g. of the reaction product of part A above, in 25 ml. of methylene chloride (containing 1.2 ml. of dihydropyran and 1.2 mg. of a saturated solution of pyridine in methylene chloride) is allowed to stand for one hour at ambient temperature. Additional dihydropyran (1.2 ml.) is added and the reaction continued for 36 hours. The reaction mixture is then washed with water, aqueous sodium bicarbonate, dried, and evaporated, yielding an oil (0.371 g.), the bis-tetrahydropyranyl lactone corresponding to the lactone reaction product of part A above. NMR absorptions are observed at 0.6-1.05, 1.05-1.4, 1.4-1.9, 1.9-3.0, 3.0-4.3, 4.0, 4.3-5.2, and 5.48 δ.
C. A solution of the reaction product of part B above (0.39 g.) in 10 ml. of toluene is cooled to -70° C. and thereafter 10 ml. of 10 percent diisobutylaluminum hydride (1.64 mmoles) in toluene (10 ml.) is slowly added. The reaction mixture is then stirred at -70° C. until thin layer chromatographic analysis indicates that the reduction is complete (about 10 min.). Thereafter the cooling bath is removed and 9 ml. of a mixture of tetrahydrofuran and water (3:1) is added slowly. The reaction mixture is then stirred and allowed to warm to room temperature, and is then filtered through a cellulose bed. The filter cake is rinsed with benzene, combined organic extracts are then dried and evaporated to yield 0.40 g. of the title compound. NMR absorptions are observed at 0.7-1.05, 1.05-1.35, 1.35-1.9, 1.9-2.8, 2.8-4.2, 4.00, and 5.60 δ.
Following the procedure of Example 8, the 3α-benzoyloxy-5-hydroxy or 5-hydroxy lactones described in and following Examples 5, 6, and 7 are transformed into corresponding γ-lactols.
Following the procedure of Example 8 there is prepared from (3S) starting material, respectively:
1. 3α,5α-Dihydroxy-2β-[2-chloro-(3S)-3-hydroxy-4,4-dimethyl-trans-1-octenyl]-1α-cyclopentaneacetic γ lactone. NMR absorptions are observed at 0.92, 1.1-1.7, 1.8-3.2, 3.2-3.5, 4.0, 4.8-5.2, and 5.66 δ. The mass spectrum shows peaks at 312, 233, 232, 231, 216, and 215.
2. 3α,5α-Dihydroxy-2β-[2-chloro-(3S)-3-hydroxy-4,4-dimethyl-trans-1-octenyl]-1α-cyclopentaneacetic acid γ lactone bis-tetrahydropyranyl ether. NMR absorptions are observed at 0.6-1.05, 1.05-1.4, 1.4-2.0, 2.0-3.0, 3.0-4.4, 4.00, 4.4-5.7, and 5.48 δ.
3. 3α,5α-Dihydroxy-2β[2-chloro-(3S)-3-hydroxy-4,4-dimethyl-trans-1-octenyl]-1α-cyclopentane acetaldehyde δ lactol bis-tetrahydropyranyl ether. NMR absorptions are observed at 0.6-1.1, 1.35-1.85, 1.85-3.0, 3.2-4.3, 4.00, 4.3-5.1, and 5.58 δ.
Further following the procedure of Example 8, but using the various lactones described following Examples 5 and 7 wherein R 16 is hydrogen, there are prepared the corresponding 5α-hydroxy-1α-cyclopentaneacetaldehyde δ lactol bis-tetrahydropyranyl ethers. Further following the procedure of Example 8, parts A and B, but using as starting material the various lactones described following Example 6, wherein R 16 is hydrogen, there are prepared the corresponding 5α-hydroxy-1α-cyclopentaneacetaldehyde δ lactols.
Further following the procedure of Example 8, but using as starting material the various lactols described following Example 5 and in and following Example 7, wherein R 16 is benzoyloxy, there are prepared the corresponding 3α,5α-dihydroxy-1α-cyclopentaneacetaldehyde γ lactol bis-tetrahydropyranyl ethers. Finally, following the procedure of Example 8, but using as starting material the various lactones described in and following Example 6, wherein R 16 is benzoyloxy, there are prepared the corresponding 3α,5α-dihydroxy-1α-cyclopentaneacetaldehyde γ lactol bis-tetrahydropyranyl ethers.
EXAMPLE 9
3-Oxa-14-chloro-PGF 1 .sub.α, 11,15-bis-(tetrahydropyranyl ether), methyl ester (Formula XXXV: g if one, R 3 and R 4 of the L 1 moiety are hydrogen, M 6 is ##STR128## R 7 is n-butyl, R 18 is tetrahydropyranyloxy, and Y 2 is trans--CH=C(Cl)--) or its 15-epimer.
Refer to Chart B.
A. 3α,5α-Dihydroxy-2β-[2-chloro-(3S)-3-hydroxy-trans1-octenyl]-1α-cyclopentaneacetaldehyde γ-lactol, bis-tetrahydropyranyl ether, (10.0 g.) is dissolved in 150 ml. of absolute ethanol (containing 3 drops of acetic acid). To this solution is added carbethoxymethylene-triphenylphosphorane (10 g.) and the mixture is stirred at ambient temperature for 72 hours. The resulting mixture is concentrated under reduced pressure to a volume of about 35 ml., mixed with ice, and dilute sodium bicarbonate solution, and shaken with ethyl acetate. The organic phase is washed with brine, dried over magnesium sulfate, and concentrated to yield a residue. The residue is slurried in 100 ml. of diethyl ether and filtered. The filtrate is concentrated to a residue which is subjected to silica gel chromatography, eluting with 20 to 40 percent ethyl acetate in Skellysolve B. There is obtained 2,3,4-trinor-14-chloro-PGF 2 .sub.α, ethyl ester, bis(tetrahydropyranyl)ether.
B. The reaction product of step A above is mixed with the 5 percent palladium-on-charcoal catalyst (0.3 g.) in 30 ml. of ethyl acetate and hydrogenated at atmospheric pressure. When about one equivalent of hydrogen is consumed, the catalyst is filtered off and the filtrate concentrated under reduced pressure to yield 2,3,4-trinor-14-chloro-PGF 1 .sub.α, ethyl ester, bis(tetrahydropyranyl)ether.
C. The reaction product of step B above (1.1 g.) in 30 ml. of diethyl ether is added with stirring to a mixture of lithium aluminum hydride (0.3 g.) in 60 ml. of diethyl ether. The addition continues over a 10 min. period. The mixture is heated at reflux for 2 hours then cooled, and treated with 0.35 ml. of water cautiously added. Thereafter 0.35 ml. of 15 percent aqueous sodium hydroxide solution is added, and thereafter one ml. of water. The solids are removed by filtration and filtrate is concentrated under reduced pressure to yield 2-decarboxy-2-hydroxymethyl-2,3,4-trinor-14-chloro-PGF 1 .sub.α, bis-tetrahydropyranyl ether.
D. The reaction product of part C above (1.7 g.) together with 15 ml. of dimethyl sulfoxide and 5 ml. of tetrahydrofuran is treated with 2.28 ml. of 1.6 molar n-butyllithium in hexane, with stirring and cooling. After 5 min. there is added 5 ml. of dimethylformamide. The resulting solution is then stirred and cooled to 0° C. Thereafter lithium chloroacetate (0.7 g.) is added. The mixture is then stirred at 0° C. for 2 hours and at about 25° C. for 22 hours. Thereafter the resulting solution is diluted with 200 ml. of ice-water, acidified with a cold solution of 3 ml. of concentrated hydrochloric acid in 50 ml. of water, and immediately extracted with dichloromethane. The organic phase is washed with cold water and brine and dried over magnesium sulfate. Accordingly, there is prepared 3-oxa-14-chloro-PGF 1 .sub.α, 11,15-bis-tetrahydropyranyl ether.
E. To the above solution is added excess ethereal diazomethane and after a few minutes the excess reagent is destroyed with acetic acid. The mixture is then washed with a mixture of sodium bicarbonate solution and brine and thereafter with brine. The resulting solution is then dried and concentrated under reduced pressure. The residue so obtained is subjected to silica gel chromatography eluting with ethyl acetate and Skellysolve B to yield the title compounds.
Following the procedure of Example 9, but using the (3R) starting material there is obtained the corresponding 15-epi product.
Following the procedure of Example 9, but using the various lactols described following Example 8, there are obtained the corresponding products. For those lactols described following Example 8, wherein the C-3 position of the cyclopentane ring is unsubstituted (R 18 is hydrogen), there are obtained the corresponding 11-deoxy products wherein the C-11 position is not etherified. When the 3-methoxy lactones described following 8 are employed there are obtained the corresponding 14-chloro-prostaglandin-type compounds wherein the C-15 position is methoxy-substituted.
Following the procedure of Example 9, but omitting the etherification step (part E) there are obtained the above compounds in free acid form.
Following the procedure of Example 9, but replacing lithium chloroacetate used in part D of Example 9 with lithium chloropropionate or lithium chlorobutyrate, there are obtained the corresponding 3-oxa-14-chloro-PGF 1 .sub.α -type compounds wherein g is 2 or 3. Further, using the various lactols described following Example 8, there are obtained the corresponding 3-oxa-14-chloro-PGF 1 .sub.α -type compounds wherein g is 2 or 3 when the above chloroalkanoates are substituted for lithium chloroacetate.
EXAMPLE 10
5-Oxa-14-chloro-PGF 1 .sub.α, methyl ester, 11,15bis-(tetrahydropyranyl) ethyl (Formula XLIII: g is one, R 3 and R 4 of the L 1 moiety are hydrogen, M 6 is ##STR129## R 1 is methyl, R 7 is n-butyl, R 18 is tetrahydropyranyloxy, and Y 2 is trans--CH=C(Cl)--) or its 15-epimer.
Refer to Chart C.
A. A mixture of lactol starting material of Example 9 (6.3 g.) and 50 ml. of 95 percent ethanol is treated at 0° C. with stirring with a solution of sodium borohydride in 10 ml. of water (added over a period of one minute). The resulting mixture is then stirred at 0° C. for 10 minutes and then shaken with 10 ml. of water, 250 ml. of ethyl acetate, and 150 ml. of brine. The organic phase is then washed with brine, dried, and concentrated under reduced pressure to yield 2-decarboxy-2-hydroxymethyl-2,3,4,5,6-pentanor-14-chloro-PGF 1 .sub..alpha., 11,15-bis-tetrahydropyranyl ether.
B. A solution of potassium tert-butoxide (1.77 g.) in 30 ml. of tetrahydrofuran is mixed at 0° C., with stirring, with a solution of the reaction product of part A (5.8 g.) in 30 ml. of tetrahydrofuran. The resulting mixture is then stirred at 0° C. for 5 minutes and thereafter 5 ml. of trimethyl ortho-4-bromobutyrate is added. Stirring is continued at 0° C. for 2 hours and at about 25° C. for 16 hours. To this mixture is added 30 ml. of dimethylformamide and 0.5 g. of potassium-t-butoxide. The resulting mixture is then stirred for 20 hours. Some of the solvent is then removed under reduced pressure and the residue is then shaken with water and diethyl ether and dichloro methane (3:1). The organic phase is then washed with water and brine, dried, and concentrated. The residue, containing the ortho ester, is dissolved in 6 ml. of methanol at 0° C. and treated with 15 ml. of cold water containing 2 drops of concentrated hydrochloric acid. The resulting mixture is then stirred at 0° C. for 5 minutes, shaken with 200 ml. of diethyl ether, 50 ml. of dichloromethane, and 200 ml. of brine. The organic phase is then washed with brine, dried, and concentrated under reduced pressure. The residue is subjected to silica gel chromatography, yielding the title compounds.
C. Trimethylortho-4-butyrate is prepared as follows:
Refer to S. M. McEldian, et al., Journal of the American Chemical Society 64, 1825 (1942). A mixture of 4-bromobutyronitrile (74 g.), 21 ml. of methanol, and 150 ml. of diethyl ether is treated at 0° C. with stirring, with hydrogen bromide (40 g.). The mixture is then stirred for an additional 4 hours at 0° C. and 100 ml. of hexane is added. The precipitated imino ester hydrobromide is separated from the liquid by filtration and washed with 400 ml. of diethyl ether in hexane (1:1). The imino ester salt is treated in 250 ml. of diethyl ether with 150 ml. of methanol and 25 ml. of methyl orthoformate, with stirring, at about 25° C. for 24 hours. The resulting mixture is then cooled to about 10° C. and the organic solution is separated from the ammonium bromide thereby formed. Diethyl ether (100 ml.) is then added. The resulting solution is then immediately and quickly washed with an ice cold solution prepared from potassium carbonate (20 g.) and 300 ml. of brine. The organic phase is washed with brine, treated with 3 drops of pyridine, and dried over anhydrous magnesium sulfate. The solution is then concentrated under reduced pressure, diluted with 150 ml. of benzene, and again concentrated. The residue is then distilled to yield the title ortho-4-bromobutyrate.
Following the procedure of part C of Example 10, but using 5-bromo pentanonitrile or 6-bromo hexanonitrile there is prepared trimethylortho-5-bromo pentanoate or trimethylortho-6-bromo hexanoate.
Following the procedure of Example 10, but using the corresponding (3R) lactone, there is obtained the corresponding 15-epi-PGF 1 .sub.α -type product.
Following the procedure of Example 10, but using any of the various lactols described following Example 8, there is prepared the corresponding 5-oxa-14-chloro-PGF 1 .sub.α -type product. For those lactols wherein the C-3 position of the cyclopentane ring is unsubstituted (R 18 is hydrogen), the corresponding 11-deoxy-PGF 1 .sub.α -type product produced is not etherified at the C-11 position. For those lactols described following Example 8, wherein the C-3 position of the side chain contains a methoxy group, the corresponding 3-oxa-14-chloro-13-PGF 1 .sub.α -type product contains no tetrahydropyranyl ether at the C-15 position.
Further, following the procedure of Example 10, but using trimethylortho-5-bromopentanoate or trimethylortho-6-bromohexanoate there is prepared the corresponding 5-oxa-14-chloro-PGF 1 .sub.α -type product wherein g is 3 or 4. Likewise using the various lactols described following Example 8, corresponding 2a-homo or 2a,2b-dihomo products are obtained.
EXAMPLE 11
4-Oxa-14-chloro-PGF 1 .sub.α 11,15-bis(tetrahydropyranyl)ether (Formula LVIII: g is one, R 3 and R 4 of the L 1 moiety are hydrogen, M 6 is ##STR130## R 1 is hydrogen, R 7 is n-butyl, R 18 is tetrahydropyranyloxy, and Y 2 is trans-CH=C(Cl)--).
Refer to Chart D.
A. A suspension of methoxymethyltriphenylphosphonium chloride (32.4 g.) in 150 ml. of tetrahydrofuran is cooled to -15° C. To the suspension is added 69.4 ml. of n-butyllithium in hexane (1.6 molar) in 45 ml. of tetrahydrofuran. After 30 minutes there is added a solution of 3α,5α-dihydroxy-2β-[2-chloro-(3S)-3-hydroxy-trans-1-octenyl]-1α-cyclopentaneacetaldehyde γ lactol bis-(tetrahydropyranyl)ether, (10 g.), in 90 ml. of tetrahydrofuran. The mixture is stirred for 1.5 hours while warming to 25° C. The resulting solution is thereafter concentrated under reduced pressure. The residue is partitioned between dichloromethane and water, the organic phase being dried and concentrated. This dry residue is then subjected to chromatography over silica gel eluting with cyclohexane and ethyl acetate (2:1). Those fractions as shown by thin layer chromatography to contain pure formula LII product are combined.
B. The reaction product of part A above in 20 ml. of tetrahydrofuran is hydrolyzed with 50 ml. of 66 percent aqueous acetic acid at about 57° C. for 2.5 hours. The resulting mixture is then concentrated under reduced pressure. Toluene is added to the residue and the solution is again concentrated. Finally the residue is subjected to chromatography on silica gel, eluting with chloroform and methanol (6:1). The title compound is thereby obtained by combining and concentrating fractions as shown by thin layer chromatography to contain pure product. Accordingly, there is obtained the corresponding formula LIII δ-lactol.
C. Silver oxide is prepared by addition of silver nitrate (1.14 g.) in water (3ml.) dropwise to a 2 normal sodium hydroxide solution (6.8 ml.). A precipitate is formed. Added to the precipitate in ice water bath is the δ lactol of part B above (1 g.) in tetrahydrofuran (4 ml.). When the addition is complete, the ice bath is removed and the reaction mixture allowed to warm to ambient temperature. When the reaction is complete, as shown by thin layer chromatography (chloroform and methanol), (9:1), impurities are removed by filtration. The filtrate is then extracted with diethyl ether. The aqueous layer is then chilled in an ice bath and acidified with 10 percent potassium bisulfate solution to pH less than 2. This aqueous mixture is then extracted with diethyl ether. The ethereal extracts are then combined, washed with brine, dried over magnesium sulfate, filtered, and evaporated under reduced pressure to yield the formula LIV lactone.
D. The formula LIV lactone prepared in part C above is then transformed to its bis-tetrahydropyranyl ether derivative following the procedure described in Example 8, part B.
E. The formula LV compound prepared in part D above is then reduced to the corresponding δ lactol bis-tetrahydropyranyl ether by the procedure described in Example 8, part C.
F. The formula LVI lactol prepared in part E above is then transformed to the corresponding formula LVII primary alcohol by the procedure described in Example 10, part A.
G. The formula LVIII compound is prepared from the formula LVII compound by etherification of the primary alcohol moiety following the procedure described in Example 10, part B, but by substituting trimethylortho-3-bromopropionate in place of trimethylortho-4-bromobutyrate.
Following the procedure of Example 11, but using the corresponding (3R) starting material in place of the (3S) starting material there is obtained the corresponding 15-epi-PGF 1 .sub.α -type product.
Following the procedure of Example 11, but using in step G, trimethyl ortho-4-bromobutyrate or ortho-5-bromopentanoate in place of trimethyl ortho-3-bromopropionate, there are obtained the corresponding formula LVIII compound wherein g is 2 or 3.
Following the procedure of Example 11, but using in place of the formula LVI lactol, the various formula XXVII lactols described following Example 8, there are obtained the corresponding 4-oxa-14-chloro-PGF 1 .sub.α -type products. Finally using the above ortho-ω-alkanoates there are prepared corresponding 2a-homo or 2a,2b-dihomo compounds.
EXAMPLE 12
cis-4,5-Didehydro-14-chloro-PGF 1 .sub.α, 11,15bis(tetrahydropyranyl) ether (Formula LIX: g is one, R 3 and R 4 of the L 1 moiety are hydrogen, M 6 is ##STR131## R 1 is hydrogen, R 7 is n-butyl, R 18 is tetrahydropyranyloxy, and Y 2 is trans-CH=C(Cl)--) and its 15epimer.
Refer to Chart D.
A. Following the procedure of Example 11, parts A, B, C, D, and E there is prepared the formula LVI lactol wherein L 1 , M 6 , R 7 , R 18 , and Y 2 are as defined for the title compound.
B. 3-Carboxypropyltriphenylphosphonium bromide (prepared by heating 4-bromobutyric acid and triphenylphosphine in benzene at reflux for 18 hours, and thereafter purifying), 106 g., is added to sodiomethylsulfinylcarbanide prepared from sodium hydride (2.08 g., 57 percent ) and 30 ml. of dimethylsulfoxide. The resulting Wittig reagent is combined with the formula LVI lactol of part A above and 20 ml. of dimethylsulfoxide. The mixture is stirred overnight, diluted with about 200 ml. of benzene, and washed with potassium hydrogen sulfate solution. The two lower layers are washed with dichloromethane, the organic phases are combined, washed with brine, dried, and concentrated under reduced pressure. The residue is subjected to chromatography over acid washed silica gel, eluting with ethyl acetate and isomeric hexanes (3:1). Those fractions as shown to contain the desired compound by thin layer chromatography are combined to yield pure product.
Following the procedure of Example 12, but using in place of the (3S) starting material the corresponding (3R) starting material there is obtained the corresponding 15-epi-14-chloro-PGF 1 .sub.α -type compound.
Following the procedure of Example 12, but using in place of the 3-carboxypropyltriphenylphosphonium bromide, 4-carboxybutyltriphenylphosphonium bromide, or 5-carboxypentyltriphenylphosphonium bromide, there are prepared the corresponding formula LIX compounds wherein g is 2 or 3.
Further, following the procedure of Example 12, but using in place of the formula LI starting material the various formula XXVII lactols described following Example 8, there are prepared the corresponding cis-4,5-didehydro-14-chloro-PGF 1 .sub.α - or 11-deoxy-PGF 1 .sub.α -type products.
EXAMPLE 13
14 -Chloro-16,16-dimethyl-PGF 2 .sub.α, methyl ester, 11,15-bis-tetrahydropyranyl ether (Formula LXII : g is 1, R 3 and R 4 of the L 1 moiety are methyl, M 6 is ##STR132## R 1 is methyl, R 2 is hydrogen, R 7 is n-butyl, R 18 is tetrahydropyranyloxy, and Y 2 is trans--CH=C(Cl)--) or its 15-epimer.
Refer to Chart E.
A. Sodium hydride (0.40 g., 57 percent in mineral oil) in 20 ml. of dimethylsulfoxide, is added to 1.82 g. of 4-carboxybutyltriphenylphosphonium bromide. The reaction mixture is maintained at 20° C. with stirring for 25 min. A solution of the title compound of Example 8 (0.39 g.) in 10 ml. of toluene is added. The reaction mixture is stirred at ambient temperature for 2 hours and diluted with benzene. Potassium bisulfate (2.7 g. in 30 ml. of water) is slowly added, maintaining the reaction temperature at less than or equal to 10° C. The aqueous layer is extracted with 50 ml. of benzene and the organic extracts are washed successfully with 50 ml. of water and 50 ml. of brine before combining, drying, and evaporating. Evaporation yields semi-crystalline residue which is chromatographed on 100 g. of acid washed silica gel eluting 20 percent ethyl acetate m-hexane. Thereby 0.241 g. of the pure free acid of the title product is obtained. NMR absorptions are observed at 0.65-1.1, 1.1-1.4, 1.4-1.8, 1.8-2.6, 2.8-4.4, 4.05, 4.4-4.8, 5.2-5.75, and 6.0-6.9 δ.
B. A solution of the reaction product of part A above and 15 ml. of diethyl ether is esterified with diazomethane, used in stoichiometric excess. The crude methyl ester is chromatographed on 100 g. of silica gel packed in 2 percent acetone methylene chloride. Elution with 2-12 percent acetone in methylene chloride yields the title compound.
Following the procedure of Example 13, but using the (3R) lactol there is obtained the corresponding 15-epi-14-chloro-PGF 2 .sub.α, methyl ester, 11,15-bis-tetrahydropyranyl ether. NMR absorptions are observed at 0.7-1.1, 1.1-1.4, 1.4-1.8, 1.8-2.55, 3.15-4.2, 3.66, 4.05, 4.5-4.8, 5.2-5.8, and 5.6 δ.
Following the procedure of Example 13, but using 5carboxypentyltriphenylphosphonium bromide or 6-carboxyhexyltriphenylphosphonium bromide in place of 4-carboxybutyltriphenylphosphonium bromide there is obtained the corresponding 2a-homo or 2a,2b-dihomo-14-chloro-PGF 2 .sub.α -type compound or its 15-epimer.
Further, following the procedure of Example 13, but using in place of 4-carboxybutyltriphenylphosphonium bromide, 4,4-difluoro-4-carboxybutyltriphenylphosphonium bromide there is obtained the corresponding 2,2-difluoro-14-chloro-PGF 2 .sub.α -type tetrahydropyranyl ether or its 15-epimer.
Further, following the procedure of Example 13, but using in place of the formula LXI lactol starting material therein one of the various lactols described following Example 8, and optional by any of the Wittig reagents described above, there are prepared the corresponding 14-chloro or 11-deoxy-14-chloro-PGF 2 .sub.α -type products.
EXAMPLE 14
15-Methyl-14-chloro-PGF 2 .sub.α, methyl ester (Formula LXXVI: R 3 and R 4 of the L 1 moiety are hydrogen, M 1 is ##STR133## M 18 is ##STR134## R 1 is methyl, R 7 is n-butyl, R 8 is hydroxy, Y 2 is trans-CH=C(Cl)--, and Z 2 is cis-CH=CH(CH 2 ) 3 --) or its 15-epimer.
A. A solution of 5.7 g. of the reaction product of Example 7, 3α-benzoyloxy-5α-hydroxy-2β-[(3S)-3-hydroxy-3-methyl-cis-1-octenyl]-1α-cyclopentaneacetic acid γ lactone in 150 ml. of methanol is deacylated according to the procedure of Example 8, part A, yielding of 3α,5+-dihydroxy-2β-[2-chloro-(3S)-3-hydroxy-3-methyl-trans-1-octenyl]-1α-cyclopentaneacetic acid γ lactone.
A sample of the corresponding (3R) starting material is deacylated in a similar fashion, yielding the corresponding (3R) product.
B. A solution of 3.65 g. of the reaction product of part A in 150 m. of tetrahydrofuran is cooled to -60° C. Diisobutylaluminum hydride and toluene (85 ml.) is added over a period of 23 minutes at a temperature of -70° C. The reaction mixture is stirred for an additional 24 minutes. Thereafter 100 ml. of saturated aqueous ammonium chloride solution is slowly added at a temperature of -60° C. The resulting mixture is then stirred and allowed to warm to room temperature, yielding a gelatin as precipitate. This mixture is then diluted with 70 ml. of water and 150 ml. of ethyl acetate, mixed thoroughly and filtered. The filter cake is washed with water and ethyl acetate. The aqueous layer is extracted with ethyl acetate. The combined organic extracts are washed with brine, dried over sodium sulfate, and evaporated to yield the lactol corresponding to lactone starting material.
C. Following the procedure of Example 13, sodium hydride in dimethylsulfoxide is combined with 4-carboxybutyltriphenylphosphonium bromide to yield the title compound in free acid form.
The reaction product of part C above is esterified with diazomethane following the procedure described above, yielding the title compound.
Following the procedure of steps B-D above, but using the deacylated (3R)-laceont there is obtained 1. 15-epi-15-methyl-14-chloro-PGF 2 .sub.α,methyl ester.
The preparation of the above title compound or its 15-epimer is optionally accomplished following the procedure of Chart F. Accordingly, the 3(RS)-3-methyl lactone corresponding the Example 7 is prepared by omitting the chromatographic separation step therein. Thereafter, by the procedure of Example 8 the corresponding 3(RS)-3-methyl lactol is prepared. Thereafter, following the procedure of Example 13, the (15RS)-15-methyl-14-chloro-PGF 2 .sub.α -bistetrahydropyranyl ether, methyl ester is prepared by methyl esterification of the free acid so formed. The tetrahydropyranyl ether moieties may then be hydrolyzed and the C-15 epimers separated by chromatographic techniques.
Following the procedure of Example 14, or the optional procedure discussed above, there are prepared 15-epi-15-methyl or 15-methyl-PGF 2 .sub.α -type compounds from the corresponding lactols described following Example 8.
Further, using the compounds described in or following Examples 9, 10, 11, 12, or 13 there are prepared the corresponding 3-oxa, 4-oxa, 5-oxa-, or cis-4,5-didehydro-15-didehydro-15-methylor 15-epi-15-methyl-14-chloro-PGF 2 .sub.α -type products.
EXAMPLE 15
15-Methyl-14-chloro-PGF 2 .sub.α (Formula LXXVI: R 3 and R 4 of the L 1 moiety are hydrogen, M 1 is ##STR135## M 18 is ##STR136## R 1 is hydrogen, R 7 is n-butyl, R 8 is hydroxy, Y 1 is trans-CH=C(Cl)--, and Z 2 is cis-CH=CH--(CH 2 ) 3 --) or its 15-epimer.
A solution of 2.0 g. of the reaction product of Example 14, or its 15-epimer, in 20 ml. of methanol is cooled to 0° C. The resulting mixture is thereafter treated dropwise under a nitrogen atmosphere with 12 ml. of 10 percent aqueous sodium hydroxide solution. The mixture is then allowed to warm to room temperature and stirred for 2 hours. After removal of the methanol by evaporation under reduced pressure the residue is diluted with water and extracted with methylene chloride. The aqueous layer is then cooled with ice, treated with 24 ml. of 2 molar aqueous sodium bisulfate solution and extracted immediately with ethyl acetate. The combined organic extracts are washed with brine, dried over anhydrous sodium sulfate, and concentrated. Crude product may then be chromatographed on 150 g. of silica gel, yielding the title compound or its 15-epimer.
Following the procedure of Example 15, but using any of the 15-methyl-14-chloro-PGF .sub.α or 11-deoxy-15-methyl-14-chloro-PGF .sub.α-type methyl esters, there are prepared the corresponding free acid products.
EXAMPLE 16
14-chloro-16,16-dimethyl-PGF 2 .sub.α methyl ester (Formula LXXVI: R 3 and R 4 of the 1 moiety are methyl, M 1 is ##STR137## M 18 is ##STR138## R 1 is methyl, R 7 is n-butyl, R 8 is hydroxy, Y is trans-CH=C(Cl)-, and Z 2 is cis-CH=CH-(CH 2 ) 3 -) or its 15-epimer.
Refer to Chart F.
14-Chloro-16,16-dimethyl-PGF 2 .sub.α -bis-tetrahydropyranyl ether (0.241 g.) is reacted with 20 ml. of tetrahydrofuran, water, and acetic acid (1:3:6) at 40° C. for 4 hours. Thereafter, the resulting mixture is diluted with 60 ml. of water and lypohylized. The residue is then esterified with diazomethane, quenching with ethereal acetic acid, and thereafter washing with sodium bicarbonate and brine, drying and evaporating to a residue. The chromatographed (eluting with methylene chloride and acetone, 3:1) residue yields 0.056 g. of pure product. NMR absorptions are observed at 0.44, 0.98, 1.1-1.42, 1.42-2.6, 2.7-3.4, 3.7, 3.8-4.5, 4.04, 5.25-5.8, and 5.65 δ. The mass spectrum shows peaks at 395, 340, 331, 296, and 281. Characteristic ester IR absorptions are observed at 1550, 1577, 1760, and 3450 cm - 1 .
Using corresponding 15-epimeric starting material the corresponding 15-epimeric product is prepared.
Following the procedure of Example 16, but using as starting material any of the 11,15-bis-tetrahydropyranyl ethers, 11-tetrahydropyranyl ethers, or 15-tetrahydropyranyl esters described in and following Examples 9, 10, 11, 12, or 13, there are prepared respectively the corresponding 14-chloro-PGF 2 .sub.α -15-methyl ether, 14-chloro-PGF 2 .sub.α -, or 11-deoxy-14-chloro-PGF 2 .sub.α, 15-methyl ether or 11-deoxy-14-chloro-PGF 2 .sub.α -type compounds.
EXAMPLE 17
15-Methyl-14-chloro-PGE 2 , methyl ester, (Formula LXXVI- R 3 and R 4 of the L 1 moiety and P 6 of the M 1 moiety are hydrogen, M 18 is ##STR139## R 1 and R 5 are methyl, R 7 is n-butyl, R 8 is hydroxy, Y 2 is trans-CH=C(Cl), and Z 2 is cis-CH=CH-(CH 2 ) 3 -) or its 15-epimer.
A. A solution of 15-methyl-14-chloro-PGF 2 .sub.α, methyl ester, 11,15-bis-tetrahydropyranyl ether, prepared above, in 60 ml. of acetone is cooled to -25° C. Thereupon 1.9 ml. of Jones reagent is added. The reaction mixture is then stirred for 25 minutes at -25° C. and isopropyl alcohol (1.9 ml.) is added after an additional 15 minutes at -25° C. the reaction mixture is diluted with 200 ml. of water (0° C.) and extracted with diethyl ether. Ethereal extracts are washed with 75 ml. of cold 0.1 normal potassium bicarbonate, 150 ml. of brine, dried over magnesium sulfate, and evaporated, thereby yielding 15-methyl-14-chloro-PGE 2 , methyl ester, 11,15-bis-tetrahydropyranyl ether.
B. A solution of the crude product of part A above is reacted with 16 ml. of tetrahydrofuran, water, and acetic acid (1:3:6) and allowed to stand at 40° C. for 4 hours. The resulting mixture is thereafter diluted with 120 ml. of water and freeze dried. The residue is dissolved in diethyl ether and washed with potassium bicarbonate, brine, and thereafter dried and evaporated to yield crude product. The crude product is chromatographed on 25 g. of silica gel packed in 5 percent acetone in methylene chloride. Elution with 5 to 40 percent acetone in methylene chloride yields the pure product.
Following the above procedure but using 15-epimeric starting material, the corresponding 15-epimer is prepared.
Following the procedure of Example 17, but using the various 15-methyl-14-chloro-PGF.sub.α or 11-deoxy-PGF.sub.α methyl ester, 11,15-bis-tetrahydropyranyl ethers, or 15-tetrahydropyranyl ethers, as prepared in or following Examples 9, 10, 11, 12, and 13 there are prepared the corresponding 15-methyl-14-chloro-PGE or 11-deoxy-14-chloro-PGE-type products.
EXAMPLE 18
15-Methyl-14-chloro-PGE 2 or its 15-epimer.
The title compound is prepared by enzymatic hydrolysis of the methyl ester of the reaction product of Example 17 or its 15-epimer.
The enzyme is prepared as follows:
Freshly harvested colony pieces of Plexaura homomalla (Esper), 1792, forma S (10 kg.), are chopped into pieces less than 3 cm. in their longest dimension and then covered with about 3 volumes (20 l.) of acetone. The mixture is stirred at about 25° C. for one hour. The solids are separated by filtration, washed with a quantity of acetone, air dried, and finally stored at about 20° C. as a coarse enzymatic powder.
The esterase hydrolysis then proceeds as follows:
The suspension of the esterase composition prepared above in 25 ml. of water is combined with the solution of the above indicated starting material. 8 ml. of methanol is added, and the resulting mixture is stirred at about 25° C. for 24 hours. 50 ml. of acetone is then added and the mixture is stirred briefly, filtered, and the filtrate is then concentrated under reduced pressure. The aqueous residue is then acidified to pH 3.5 with citric acid and extracted with dichloromethane. The combined extracts are concentrated under reduced pressure to yield the title acid.
Following the procedure of Example 18, but using the various methyl esters described following Example 17, the corresponding products are prepared.
EXAMPLE 19
14-Chloro-PGF 1 .sub.α, methyl ester, or its 15-epimer.
A solution of 4.8 g. of 14-chloro-PGF 2 .sub.α, methyl ester in 90 ml. of acetone and 60 ml. of benzene containing 0.75 g. of tris(triphenylphosphine)rhodium (1) chloride is shaken under hydrogen atmosphere at ambient temperature at 1 to 3 atmospheres pressure for 3.5 hours. Thereafter the solvent is evaporated and the residue chromatographed on 400 g. of silica gel packed in methylene chloride eluting with one to 6 percent methanol in methylene chloride. There is recovered 0.90 g. of impure product. The above product is purified using silica gel chromatography, thereby preparing pure product.
Following the above procedure, but using 15-epi-14-chloro-PGF 2 .sub.α, methyl ester, there is prepared the corresponding 15-epi-14-chloro-PGF 1 .sub.α, methyl ester.
Following the procedure of Example 20, but using in place of the indicated starting material any of the PGF 2 .sub.α or 11-deoxy-PGF 2 .sub.α -type compounds described in or following Example 13, there are prepared the corresponding PGF 1 .sub.α or 11-deoxy-PGF 1 .sub.α -type products.
EXAMPLE 20
14-Chloro-PGE 1 , methyl ester, or its 15-epimer
The title compound of this Example is prepared by oxidation of the compound of Example 19, using the procedure described in Example 17, part A.
Using the corresponding 15-epimer, there is prepared 15-epi-14-chloro-PGE 1 , methyl ester.
Following the procedure of Example 20, but using any of the 11-deoxy-PGF 1 .sub.α - or PGF 1 .sub.α -type compounds described following Example 19, there are prepared the corresponding 11-deoxy-PGE 1 - or PGE 1 -type compounds.
Accordingly, following the procedures of Examples 14-20 there are prepared the various 14-chloro-PGF 2 .sub.α -, 2,2-difluoro-PGF 2 .sub.α -, 2a,2b-dihomo-PGF 2 .sub.α -, 3-oxa-PGF 1 .sub.α, 5-oxa-PGF 1 .sub.α -, 4-oxa-PGF 1 .sub.α, cis-4,5-didehydro-PGF 1 .sub.α -, PGF 1 .sub.α -, 2,2-difluoro-PGF 1 .sub.α -, or 2a,2b-dihomo-PGF 1 .sub.α -type compounds or the corresponding PGE-type compounds, optionally substituted at C-15 with methyl or methoxy, at C-16 with one or 2 methyl, or one or 2 fluoro, or phenoxy, or optionally substituted at C-17 with a phenyl or substituted phenyl moiety.
EXAMPLE 21
14-Chloro-16,16-dimethyl-PGF 2 β, methyl ester (Formula LXXVII: R 3 and R 4 of the L 1 moiety are methyl, M 1 is ##STR140## R 1 is methyl, R 7 is n-butyl, R 8 is hydroxy, Y 2 is trans-CH=C(Cl)--, and Z 2 is cis-CH=CH--(CH 2 ) 3 --).
Refer to Chart F.
A solution of 0.3 g. of 14-chloro-16,16-dimethyl-PGE 2 , methyl ester, in 15 ml. of methanol is cooled to -15° C. Thereafter 16 mg. of borohydride is added. After 45 minutes, 2 ml. of 50 percent acetic acid in water is slowly added. The reaction mixture is then allowed to warm to ambient temperature and then evaporated at reduced pressure. The residue is then shaken with ethyl acetate and water. The organic phase is then washed with aqueous sodium bicarbonate, brine, and then dried and evaporated to yield crude product. A column of 25 g. of silica gel packed in ethyl acetate is eluted with 70-100 percent ethyl acetate in cyclohexane. Crude product is then rechromatographed eluting with 0.5 to 3 percent methanol in methylene chloride. Rechromatographing yields the 9β-epimer.
Using the corresponding 15-epimeric starting material the corresponding 15-epimeric product is prepared.
Following the procedure of Example 21, but using the various PGE 2 -, 11-deoxy-PGE 2 -, PGE 1 -, or 11-deoxy -PGE 1 -type compounds described in the preceding examples, there are obtained the corresponding PGF 2 .sub.β, 11-deoxy-PGF 2 .sub.β, PGF 1 .sub.β, or 11-deoxy-PGF 1 .sub.β -type compounds.
EXAMPLE 22
14-Chloro-16,16-dimethyl-PGA 2 (Formula LXXVIII: R 3 and R 4 of the L 1 moiety are methyl, M 1 is ##STR141## R 1 is hydrogen, R 7 is n-butyl, Y 2 is trans-CH=C(Cl)-, and Z 2 is cis-CH=CH-(CH 2 ) 3 -).
Refer to Chart F.
A solution of 14-chloro-16,16-dimethyl-PGE 2 (300 mg.), 4 ml. of tetrahydrofuran, and 4 ml. of 0.5 normal hydrochloric acid is left standing at ambient temperature for 5 days. Brine and dichloromethane in ether (1:3) are added and the mixture is stirred. The organic phase is separated, dried, and concentrated. The residue is dissolved in diethyl ether and the solution is extracted with aqueous sodium bicarbonate. The aqueous phase is acidified with dilute hydrochloric acid and then extracted with dichloromethane. This extract is then dried and concentrated to yield the title compound.
Following the procedure of Example 22, but using any of the PGE 2 - or PGE 1 - type compounds described above there are respectively prepared the corresponding PGA 2 - or PGA 1 - type compounds.
EXAMPLE 23
14-Chloro-16,16-dimethyl-PGB 2 (Formula LXXIX: R 3 and R 4 of the L 1 moiety are methyl, M 1 is ##STR142## R 1 is hydrogen, R 7 is n-butyl, Y 2 is trans-CH=C(Cl)-, and Z 2 is cis-CH=CH-(CH 2 ) 3 -).
Refer to Chart F.
A solution of 14-chloro-16,16-dimethyl-PGE 2 (200 mg.) and 100 ml. of 50 percent aqueous methanol containing about 1 g. of potassium hydroxide is kept at ambient temperature for 10 hours under nitrogen atmosphere. The resulting solution is then cooled to 10° C. and neutralized by addition of 3 normal hydrochloric acid at 10° C. This solution is then extracted repeatedly with ethyl acetate and the combined organic extracts are washed with water, then washed with brine, dried, and concentrated to yield the title compound.
Following the procedure of Example 23, but using any of the PGE 2 or PGE 1 -type compounds described in the above Examples, there are prepared the corresponding PGB 2 and PGB 1 -type compounds.
EXAMPLE 24
14-Chloro-16,16-dimethyl-PGF 2 .sub.α sodium salt.
A solution of 14-chloro-16,16-dimethyl-PGF 2 .sub.α (100 mg.) in 50 ml. of water ethanol mixture (1:1) is cooled at 5° C. and neutralized with an equivalent amount of 0.1 normal aqueous sodium hydroxide solution. The neutral solution is then concentrated to a residue of the title compound.
Following the procedure of Example 24, using potassium hydroxide, calcium hydroxide, tetramethyl ammonium hydroxide, or benzyltrimethylammonium hydroxide in place of sodium hydroxide there is obtained the corresponding salts of 14-chloro-16,16-dimethyl-PGF 2 .sub.α. Likewise following the procedure of Example 24 each of the various other prostaglandin-type acids described above is transformed to the corresponding sodium, potassium, calcium, trimethylammonium, or benzyltrimethylammonium salt.
EXAMPLE 25
3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGF 1 .sub.α (Formula XC: R 1 is hydrogen, R 3 and R 4 of the L 1 moiety are hydrogen, g is one, and R 7 is n-butyl) or 3,7-inter-m-phenylene-4,5,6-trinor-PGF 1 .sub.α.
Refer to Chart G.
A. Optically Active Bicyclo[3.1.0]-hex-2-ene-6-endocarboxaldehyde.
Following the procedure of Preparation 1 of U.S. Pat. No. 3,711,515, racemic bicyclo[3.1.0]hex-2-ene-6-endo-carboxaldehyde is prepared from bicyclo[2.2.1]hepta-2,5-diene and peracetic acid.
The racemic compound is resolved by the procedure of Example 13 of U.S. Pat. No. 3,711,515, forming an oxazolidine as follows:
Racemic bicyclo[3.1.0]hex-2-ene-6-endo-carboxaldehyde (12.3 g.) and 1-ephedrine (16.5 g.) are dissolved in about 150 ml. of benzene. The benzene is removed under vacuum and the residue taken up in about 150 ml. of isopropyl ether. The solution is filtered, then cooled to -13° C. to yield crystals of 2-endo-bicyclo-[3.1.0]hex-2-en-6-yl-3,4-dimethyl-5-phenyl-oxazolidine, 11.1 g., m.p. 90° -92° C. Three recrystallizations from isopropyl ether, cooling each time to about -2° C., yield crystals of the oxazolidine, 2.2 g., m.p. 100° -103° C., now substantially a single isomeric form as shown by NMR.
The above re-crystallized oxazolidine (1.0 g.) is dissolved in a few ml. of dichloromethane, charged to a 20 g. silica gel column and eluted with dichloromethane. The silica gel is chromatograph-grade (Merck), 0.05-0.2 mm. particle size, with about 4-5 g. of water per 100 g. Fractions of the eluate are collected, and those shown by thin layer chromatography (TLC) to contain the desired compound are combined and evaporated to an oil (360 mg.). This oil is shown by NMR to be the desired title compound, substantially free of the ephedrine, in substantially a single optically-active isomeric form. Points on the circular dichroism curve are (λ in nm., 0): 350, 0; 322.5, 4,854; 312, -5,683; 302.5, -4,854; 269, 0; 250, 2,368; 240, 0; and 210, -34,600.
B. 1-Bicyclo[3.1.0]hex-2-ene-6-endo-carboxaldehyde Neopentyl Glycol Acetal (Formula LXXXI: R 55 and R 56 taken together are --CH 2 --C(CH 3 ) 2 --CH 2 -- and ˜ is endo).
A mixture of 2,2-dimethyl-1,3-propanediol (900 g.), 5 l of benzene, and 3 ml. of 85 percent phosphoric acid is heated at reflux. To it is added, in 1.5 hours, a solution of optically active bicyclo[3.1.0]hex-2-ene-6-endo-carboxaldehyde (part A, 500 g.) in one liter of benzene. Provision is made to take off azeotropically distilled water with a Dean-Stark trap. After 3 hours the mixture is cooled and extracted with 2 liters of 5 percent sodium bicarbonate. The organic phase is dried over sodium sulfate and concentrated under reduced pressure. The resulting semisolid residue is taken up in methanol and recrystallized, using a total of 1200 ml. of methanol to which 600 ml. of water is added, then chilled to -13° C. to yield 300 g. of the title compound, m.p. 52°-55° C., and having NMR peaks at 0.66, 1.20, 0.83-2.65, 3.17-3.8, 3.96, and 5.47-5.88 δ, [α] D -227° (C=0.8976 in methanol), and R f 0.60 (TLC on silica gel in 25 percent ethyl acetate in mixed isomeric hexanes). Further work-up of the mother liquors yields 50-100 g. of additional product.
C. d-8-(m-Acetoxyphenyl)-7-oxa-tricyclo-[4.2.0.0 2 ,4 ]-octene-6-endo-carboxaldehyde Neopentyl Glycol Acetal (Formula LXXXII: R 55 and R 56 taken together are --CH 2 --C(CH 3 ) 2 --CH 2-- , R 63 is ##STR143## and ˜ is endo).
A solution of the formula LXXXI 1-bicyclo[3.1.0]hex-2-ene-6-endo-carboxaldehyde neopentyl glycol acetate (Part B, 5.82 g.) and m-acetoxy-benzaldehyde (1.64 g.) in 25 ml. of benzene is charged to a Pyrex photolysis vessel equipped with an immersible water-cooled cold-finger and a fritted gas inlet tube. Dissolved oxygen is removed by bubbling nitrogen through the solution. The mixture is then irradiated at 350 nm. with a Rayonet Type RS Preparation Photochemical Reactor (The Southern New England Ultraviolet Co., Middletown, Conn.) equipped with six RUL 3500 A lamps. After 24 hours the photolysate is concentrated under reduced pressure to a pale yellow oil, 10 g., which is subjected to silica gel chromatography. Elution with 10-70 percent ethyl acetate in Skellysolve B (mixture of isomeric hexanes) yields separate fractions of the recovered starting materials and the formula LXXXII title compound, a pale yellow oil, 0.86 g., having NMR peaks at 0.68, 1.20, 0.8-2.5, 2.28, 2.99, 3,12-3.88, 3.48, 4.97-5.52, and 6.78-7.60 δ; infrared absorption bands at 3040, 2950, 2860, 2840, 1765, 1610, 1590, 1485, 1470, 1370, 1205, 1115, 1020, 1005, 990, 790, and 700 cm. - 1 ; mass spectral peaks at 358, 357, 116, 115, 108, 107, 79, 70, 69, 45,43, and 51; [α] D +55° (C=0.7505 in 95 percent ethanol); and R f 0.18 (TLC on silica gel in 25 percent ethyl acetate in mixed isomeric hexanes).
D. d-2-Exo-[m-(pivaloyloxy)benzyl]-3-exo-bicyclo[3.1.0]hexane-6-endo-carboxaldehyde Neopentyl Glycol Acetal (Formula LXXXIV: R 55 and R 56 taken together, R 68 is ##STR144## and ˜ is endo).
A mixture of lithium (0.25 g.) in 70 ml. of ethylamine is prepared at 0° C. and cooled to -78° C. A solution of the formula LXXXII d-8-(m-acetoxyphenyl)-7-oxa-tricyclo-[4.2.0.0 2 ,4 ]-octane-6-endo-carboxaldehyde neopentyl glycol acetal (part C 1.83 g.) in 10 ml. of tetrahydrofuran is added dropwise in about 5 minutes. After stirring at -78° C. for about 3.5 hours the reaction is quenched with solid ammonium chloride and water-tetrahydrofuran. Unreacted lithium is removed, the mixture is warmed slowly to about 25° C., and ethylamine is removed. The residue is neutralized with dilute acetic acid, mixed with 200 ml. of brine, and extracted with ethyl acetate. The organic phase is washed with brine and a mixture of brine and saturated aqueous sodium bicarbonate (1:1), and dried over sodium sulfate. Concentration under reduced pressure yields the formula LXIII diol as a pale tan foamed oil, 1.64 g., having R f 0.03 (TLC on silica gel in 25 percent ethyl acetate in mixed isomeric hexanes).
The product of the preceeding paragraph is dissolved in 30 ml. of pyridine and treated with 1.5 ml. of pivaloyl chloride over a period of 22 hours at about 25° C. The reaction mixture is mixed with water, then brine and extracted with ethyl acetate. The organic phase is washed successively with brine, water, saturated aqueous copper (II) sulfate, saturated aqueous sodium bicarbonate, and brine, and dried over sodium sulfate. Concentration under reduced pressure yields a residue, 2.53 g., which is subjected to silica gel chromatography to yield the formula LXXIV title compound, 1.87 g., having NMR peaks at 0.71, 1.20, 1.33, 0.9-3.1, 3.28-4.00, 4.17, 4.7-5.2, and 6.77-7.53 δ; mass spectral peaks at 486, 485, 115, 73, 72, 57, 44, 43, 42, 41, 30, 29, 15; [α] D +10° (C=0.8385 in ethanol); and R f 0.50 (TLC on silica gel in 25 percent ethyl acetate in mixed isomeric hexanes).
E. 2-Exo-[m-(pivaloyloxy)benzyl]-3-exo-(pivaloyloxy)bicyclo[3.1.0]hexane-6-endo-carboxaldehyde (Formula LXXXV: R 66 is ##STR145## and ˜ is endo).
The formula LXXXIV acetal, i.e. d-2-exo-(m-pivaloyloxy)-benzyl]-3-exo-(pivaloyloxy)-bicyclo[3.1.0]hexane-6-endocarboxaldehyde neopentyl glycol acetal (part D, 0.48 g.) is treated at 0° C. with 25 ml. of 88 percent formic acid for 4 hours. The mixture is diluted with 200 ml. of brine and extracted with ethyl acetate. The organic phase is washed with brine and saturated aqueous sodium bicarbonate, and dried over magnesium sulfate. Concentration under reduced pressure yields an oil, 0.55 g., which is subjected to silica gel chromatography. Elution with 5-15 percent ethyl acetate in Skellysolve B yields the formula LXXXV title compound as an oil, 0.37 g., having NMR peaks at 1.20, 1.33, 0.6-3.2, 5.1-5.5, 6.6-7.5, and 9.73 δ; and R f 0.50 (TLC on silica gel in 25 percent ethyl acetate in mixed isomeric hexanes).
F. 2-Exo-[m-(pivaloyloxy)benzyl]-3-exo-(pivaloyloxy)-6-endo-(cis-1-heptenyl)-bicyclo[3.1.0]hexane (Formula LXXXVI: R 3 and R 4 of the L 1 moiety are both hydrogen, R 7 is n-butyl, R 66 is ##STR146## R 53 is hydrogen, and ˜ is endo); and 2-Exo-(m-hydroxybenzyl)-3-exo-hydroxy-6-endo-(cis-1-heptenyl)bicyclo[3.1.0]hexane (Formula LXXXVII: R 3 and R 4 of the L 1 moiety are both hydrogen, R 7 is n-butyl, R 53 and R 66 are hydrogen, and ˜ is endo).
A Wittig ylid reagent is prepared in 10 ml. of benzene from n-hexyltriphenylphosphonium bromide (0.79 g.) and n-butyllithium (0.6 ml. of 2.32 M. solution in hexane) at about 25° C. for 0.5 hours. After the precipitated lithium bromide has settled, the solution is removed and added to a cold (0° C.) slurry of the formula LXXXV aldehyde (part E, 0.37 g.). After 15 minutes there is added 1.0 ml. of acetone and the mixture is heated to 60° C. for 10 minutes. The mixture is concentrated under reduced pressure. The residue is washed with 10 percent ethyl acetate in Skellysolve B and these washings are concentrated to the formula LXXXVI title compound, an oil, 0.33 g. having NMR peaks at 1.18, 1.33, 0.6-3.2, 4.5-6.0, and 6.67-7.62 δ; and R f 0.78 (TLC on silica gel in 25 percent ethyl acetate in Skellysolve B).
The above product of the preceeding paragraph is transformed to the formula LXXXVII diol by treatment with sodium methoxide (2.5 ml. of a 25 percent solution in methanol) for 4 hours, followed by addition of 0.5 g. of solid sodium methoxide and further stirring for 15 hours at 25° C., then at reflux for 6 hours. The mixture is cooled, mixed with 300 ml. of brine, and extracted with ethyl acetate. The organic phase is washed with brine, dried over magnesium sulfate, and concentrated under reduced pressure to a residue, 0.27 g. The residue is subjected to silica gel chromatography, eluting with 25-35 percent ethyl acetate in Skellysolve B, to yield the formula-LXXXVII title compound as an oil, 0.21 g., having NMR peaks at 0.87, 0.6-3.25, 3.88-4.35, 4.82-5.92, and 6.47-7.33 δ; and R f 0.13 (TLC on silica gel in 25 percent ethyl acetate in Skellysolve B).
G. 2-Exo-{m-[(methoxycarbonyl)methoxybenzyl]}-3-exohydroxy-6-endo-(cis-1-heptenyl)bicyclo[3.1.0]hexane (Formula LXXXVIII: R 3 and R 4 of the L 1 moiety are both hydrogen, g is one, R 7 is n-butyl, R 1 , R 53 , and R 66 are hydrogen, and ˜ is endo).
The formula LXXXVII diol, i.e. 2-exo(m-hydroxybenzyl)-3-exo-hydroxy-6-endo(cis-1-heptenyl)bicyclo[3.1.0]hexane (part F, 0.19 g.) is treated in 8 ml. of dioxane with bromoacetic acid (0.61 g.) and 6 ml. of 1N aqueous sodium hydroxide. After the mixture has been heated at reflux for 3 hours, with sodium hydroxide solution added when necessary to maintain a pH of about 10, the mixture is cooled, diluted with 100 ml. of water, and extracted with diethyl ether. The aqueous phase is acidified to pH 1-2 and extracted with ethyl acetate to yield the formula-LXXXVII title compound, a pale yellow oil, 0.20 g. Recovered formula LXXXVII diol is obtained from the diethyl ether organic phase on drying and concentrating, 0.025 g.
H. 3-Oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGF 1 .sub.α (Formula XC: R 3 and R 4 of the L 1 moiety an R 5 and R 6 of the M 9 moiety are all hydrogen, R 7 is n-butyl, g is one, and R 1 is hydrogen).
The formula LXXXVIII alkene is transformed to formula XC compound applying the procedure disclosed in U.S. Pat. No. 3,711,515. Thus, compound LXXXVIII (part G) is hydroxylated by the procedures of Example 6 of that patent to the formula LXXXIX glycol of Chart G, using osmium tetroxide either alone or in combination with N-methylmorpholine oxide-hydrogen peroxide complex.
The glycol is then either (1) sulfonated, for example to yield the bismesylate, and then hydrolyzed to a mixture of the title compound and its 5-epimer, applying the procedures of Example 7 of that patent, or (2) treated with substantially 100 percent formic acid to form the diformate of VIII and thereafter hydrolyzed to a mixture of the title compound and its 15-epimer, applying the procedures of Examples 20 and 21 of that patent. The epimers are separated by silica gel chromatography to yield the formula XC compound or its 15-epimer.
A third route from glycol LXXXIX to the formula XC compound is by way of a cyclic ortho ester ##STR147## wherein R 74 , R 75 , and ˜ are as defined above. The glycol is treated as a 1-20 percent solution in benzene with trimethyl orthoformate (1.5-10 molar equivalents) and a catalytic amount (1 percent of the weight of the glycol) of pyridine hydrochloride at about 25° C. The reaction is followed by TLC (thin layer chromatography) and is complete in a few minutes. There is thus obtained the cyclic ortho ester in 100 percent yield.
The cyclic ester is then treated with 20 volumes of 100 percent formic acid at about 25° C. In about 10 minutes the reaction mixture is quenched in water or aqueous alkaline bicarbonate solution and extracted with dichloromethane. The organic phase is shaken with 5 percent aqueous sodium bicarbonate, dried over sodium sulfate, and concentrated to yield the corresponding diester. The diester is contacted with 10-50 volumes of anhydrous methanol and 10-20 percent of its weight of potassium carbonate at about 25° C. until the ester groups are removed. The mixture of epimers thusly obtained is separated by silica gel chromatography yielding the two 15-epimeric forms of the formula XC compound.
1. 2-Exo-[m-(carboxyethyl)benzyl]-3-exo-hydroxy-6-endo(cis-1-heptenyl)bicyclo-[3.1.0]hexane (Formula CII: Z 3 is methylene, g is one, R 3 and R 4 of the L 1 moiety are hydrogen, R 7 is n-butyl, R 1 and R 53 are hydrogen and ˜ is endo).
With respect to Chart H, there is first prepared the formula XCVII oxetane. Following the procedures of parts B and C, but replacing the m-acetoxybenzaldehyde of part B with the aldehyde of the formula ##STR148## wherein R 69 is as defined above, the corresponding formula XCVII oxetanes are obtained with a fully developed side chain.
Thereafter, following the procedures of parts D, E, and F, but replacing the formula LXXXII oxetane of part D with the oxetane obtained by the procedure of the preceeding paragraph of this part, there are obtained the corresponding formula CI products.
Finally, the blocking groups on each CI compound are removed by methods disclosed herein or known in the art to yield the formula CII compound.
J. 3,7-inter-m-phenylene-4,5,6-trinor-PGF 1 .sub.α. Following the procedures of part H, the formula CII alkene is transformed in several steps to the title product.
Following the procedure of Example 25 or optionally following the procedure described in the text accompanying Charts I and J, there are prepared the various 3,7-inter-m-phenylene-3-oxa-4,5,6-trinor- or 3,7-inter-m-phenylene-4,5,6-trinor-PGF 1 .sub.α -type compounds described in Charts G, H, I, and J, particularly those optionally substituted at C-16 with methyl, fluoro, phenoxy, or substituted phenoxy, or at C-17 with phenyl or substituted phenyl.
EXAMPLE 26
15-Methyl-13,14-didehydro-PGF 2 .sub.α, methyl ester (Formula CLXXXII: R 1 and R 5 are methyl, R 3 and R 4 of the L 1 moiety and R 6 of the M 1 moiety are all hydrogen, R 7 is n-butyl, Y 1 is --C.tbd.C--, Z 1 is cis-CH=CH--(CH 2 ) 3 -- and ##STR149## is ##STR150##
Refer to Charts L and R.
A. 15-Keto-PGF 2 .sub.α, methyl ester, (14.4 g.) a formula CXXXII compound, in pyridine (35 ml.) is treated with benzoyl chloride (10.5 ml.) and the reaction is allowed to continue for 2 hours. Thereafter, the resulting mixture is diluted with ice water, cooled, and diluted with ice cold 10 percent sulfuric acid and methylene chloride. The layers are then separated and the organic layer is then dried and evaporated yielding 24.18 g. of crude formula CXXXIII product (R 16 is benzoyloxy). Chromatographic purification of this crude product (15.8 g.) on silica gel (600 g.) eluting with 15 percent ethyl acetate in hexane yields 13.6 g. of pure compound.
B. The reaction product of part A (5.0 g.) in carbon tetrachloride (35 ml.) is cooled to freezing and bromine (1.38 g.) is added dropwise. The reaction is then diluted with methylene chloride, washed with sodium bicarbonate, dried, and evaporated to yield 5.6 g. of a crude 13,14-dibromo product. This crude dibromo product in pyridine (25 ml.) is heated to 90°-95° C. for 1.5 hours. The mixture is then allowed to stand at room temperature for 24 hours and thereafter diluted with methylene chloride. The resulting dark solution is then partitioned with ice cold 5 percent sulfuric acid. The organic extract is washed with brine and sodium bicarbonate, dried, and evaporated to yield 5 g. of crude formula CXXXIV product. Chromatographic purification on silica gel (320 g.), eluting with 5 percent ethyl acetate in benzene, yields 2.13 g. of product.
C. A solution of the reaction product of part B (6.32 g.) in tetrahydrofuran (45 ml.) at -78° C. is treated dropwise with excess ethereal methyl magnesium bromide. The reaction proceeds for 5 minutes, and is thereafter quenched by addition of aqueous potassium bisulfite. The reaction is then diluted with diethyl ether, washed with brine, dried, and evaporated to yield 6.5 g. of crude formula CXXXV compound. The crude product is then purified on silica gel (315 g.), eluting with 7.5 percent ethyl acetate in benzene, yielding 4.28 g. of the formula CXXXV compound as a mixture of C-15 epimers.
D. A solution of the reaction product of part C above (4.28 g.) in methanol (45 ml.) is treated with potassium carbonate (1.5 g.) at ambient temperature for 72 hours. The resulting solution is thereafter concentrated under reduced pressure, diluted with 5 percent sodium chloride solution, and extracted with methylene chloride. The aqueous phase is then cooled, acidified with 0.2 molar potassium bisulfate, and thereafter extracted successively with methylene chloride in methyl acetate. The carboxylic acid containing fraction is washed with brine, dried and evaporated to yield 3.2 g. of the formula CXXXVI compound (R 1 is hydrogen) as an epimeric mixture. This epimeric mixture is then esterified with excess diazomethane, yielding 2.32 g. of the corresponding methyl ester. High pressure liquid chromatography of this mixture of methyl esters on silica gel (512 g.) yields 15-epi-15-methyl-14-bromo-PGF 2 .sub.α, methyl ester, (0.75 g.) and 15-methyl-14-bromo-PGF 2 .sub.α, methyl ester (0.21 g.). Additional chromatographic runs yield 0.26 g. of the (15S)-compound.
The reaction product of part A exhibits NMR absorption at 0.89, 1.3-1.5, 3.61, 5.25-5.75, 6.3, 6.8-7.25, 7.25-7.7, and 7.75-8.2 δ. Infrared absorptions are observed at 1250, 1575, 1594, 1625, 1680, and 1740.
The reaction product of part B exhibits NMR absorptions at 0.70-1.1, 1.1-3.05, 3.63, 5.25-5.8, 7.17, and 7.2-8.25 δ. The mass spectrum shows peaks at 625, 530, 451, 408, 328, 497, and 105. Characteristic infrared absorptions are observed at 1720, 1610, and 1270 cm..sup. -1 .
The (15RS) epimeric mixture produced in step 3 exhibits NMR absorptions at 0.8-1.1, 1.1-3.4, 1.48, 3.62, 3.9-5.8, 6.15, 6.06, and 7.10-8.2 δ.
For 15-methyl-14-bromo-PGF 2 .sub.α, methyl ester, NMR absorptions are observed at 0.7-1.1, 1.1-1.3, 1.49, 3.68, 3.85-4.4, 5.2-5.6, and 5.90 δ. The mass spectrum shows base peak absorption at 604.2587, and other peaks at 586, 571, 533, 525, 507, 347, and 217. For 15-epi-15-methyl-14-bromo-PGF 2 .sub.α, methyl ester, NMR absorptions are observed at 0.7-1.1, 1.1-3.4, 1.47, 3.8-4.4, 4.25-5.6, and 5.93 δ. Mass spectrum shows base peak absorption at 504.2615 and other peaks at 586, 573, 571, 533, 525, 514, 507, 496, 437, and 217.
E. A solution of the reaction product of part D, the 15-epi compound (0.19 g.) in dimethyl sulfoxide (9 ml.) is treated with 0.5 molar potassium tert-butoxide in dimethyl sulfoxide (0.9 ml.). Silver nitrate impregnated silica gel thin layer chromatography is used to monitor the progress of the reaction. After 2 hours, the reaction being complete, the reaction mixture is diluted with diethyl ether, washed with ice cold potassium bisulfate, a 5 percent sodium chloride solution, and a 5 percent sodium bicarbonate solution. Thereafter drying and evaporation of solvent yields 0.126 g. of crude (15R) title product.
The 15-epimer is prepared by the above process or is alternatively prepared by saponification of the methyl ester of the formula CXXXVI compound, dehydrohalogenation of the saponified product, and finally methyl esterification of the dehydrohalogenated product. According to this route a solution of the reaction product of part D (0.55 g.) in methanol (30 ml.) is treated with 2N sodium hydroxide (5 ml.) for 18 hours. The reaction is thereafter diluted with benzene and 0.2 M potassium bisulfate solution. The organic phase is then washed with 5 percent sodium chloride solution, dried, and evaporated to yield 0.49 g. of 15-epi-15-methyl-14-bromo-PGF 2 .sub.α. NMR absorptions are observed at 0.7-1.1, 1.1-3.4, 3.7-4.4, 5.1-5.75, and 5.95 δ. Characteristic infrared absorptions are observed at 3300, 2600, and 1725 cm..sup. -1 . Thereafter dehydrohalogenation proceeds by reacting the above free acid (0.49 g.) in 10 percent methanolic dimethylsulfoxide (7 ml.) with sodium methoxide (4.43 mmol) in 10 percent methanolic dimethyl sulfoxide (10.2 ml.). This mixture reacts for 20 hours. Thereafter the reaction mixture is diluted with benzene, washed with ethyl acetate and benzene (1:1). The combined organic extracts are then washed with saturated sodium chloride, dried, and evaporated to yield 0.31 g. of crude 15-epi-15-methyl-13,14-didehydro-PGF 2 .sub.α. This crude product is then esterified with excess diazomethane, under a nitrogen atmosphere, followed by evaporation to yield 2.8 g. of crude methyl ester. Purification on silica gel (25 g.) eluting with methylene chloride in acetone yields 0.211 g. of pure 15-epi-15-methyl-13,14-didehydro-PGF 2 .sub.α, methyl ester. For the free acid NMR absorptions are observed at 0.7-1.1, 1.1-3.2, 1.45, 4.0-4.5, and 5.4-6.0 δ. Characteristic absorptions are observed at 3200 to 3400, 2600 to 2700, 2220, and 1710 cm..sup. -1 . For the methyl ester NMR absorptions are observed at 0.8-1.1, 1.1- 3.2, 1.46, 4.0-4.5, 5.3-5.6 δ.
Following the alternate procedure described above for the preparation of 15-epi-15-methyl-13,14-didehydro-PGF 2 .sub.α, methyl ester, there is prepared 15-methyl-13,14-didehydro-PGF 2 .sub.α, methyl ester. Accordingly, a solution of 15-methyl-14-bromo-PGF 2 .sub.α, methyl ester (0.41 g.) in methanol (25 ml.) is treated with 10 percent aqueous sodium hydroxide (6 ml.) and the resulting reaction is allowed to proceed overnight at ambient temperature. The corresponding acid is thereafter isolated as in the procedure described above for the preparation of 15-epimer to yield 0.34 g. of crude free acid.
Without further purification 0.32 g. of the free acid obtained above in a mixture of dimethylsulfoxide in methanol (9:1; 10 ml.) is treated with 0.43 M sodium methoxide in a mixture of dimethyl sulfoxide and methanol (9:1; 6.6 ml.). After 20 hours the resulting solution is partitioned by adding ice cold 0.2 M potassium bisulfate in benzene. The aqueous phase is extracted with the mixture of benzene and ethyl acetate (1:1) and the combined extracts are washed with brine, dried, and evaporated to yield 0.180 g. of crude 15-methyl-13,14-didehydro-PGF 2 .sub.α. After diazomethane esterification (following the procedure described above) crude title product is prepared which is subjected to silica gel chromatography (25 g.), eluting with acetone and methylene chloride (4:1). Thereby pure 15-methyl-13,14-didehydro-PGF 2 .sub.α, methyl ester (0.109 g.) is obtained. NMR absorptions are observed at 0.7-1.1, 1.1-3.5, 1.46, 3.69, 4.0-4.5, and 5.3-5.7 δ. The mass spectrum shows base peak absorption at 581.3508 and other peaks at 596, 525, 506, 491, 435, 416, 345, 255, and 217. Characteristic infrared absorptions are observed at 3350, 2900, 2220, and 1740 cm..sup. -1 .
Following the procedure of Example 26, but using in place of 15-keto-PGF 2 .sub.α, methyl ester, each of the various 15-keto-PGF-type compounds known in the art or readily available by methods known in the art, there are prepared the corresponding 13,14-didehydro-PGF-type products. Accordingly, 3,7-inter-m-phenylene-3-oxa-4,5,6-trinor-PGF 1 .sub.α is transformed to 15-keto-3,7-inter-m-phenylene-3-oxa-4,5,6-trinor-PGF 1 .sub.α, and this 15-keto compound is transformed following the procedure of Example 26 to 3,7-inter-m-phenylene-3-oxa-4,5,6-trinor-13,14-didehydro-PGF 1 .sub..alpha.. Likewise, 3,7-inter-m-phenylene-4,5,6-trinor-PGF 1 .sub.α is transformed to 3,7-inter-m-phenylene-4,5,6-trinor-13,14-didehydro-PGF 1 .sub.α. Further, following the procedure described in Examples 4-16 and Example 19, but omitting the 2-chlorination of Example 4, there are prepared various PGF-type compounds which are transformed, as described above to corresponding 15-keto-PGF-type compounds. Each of these 15-keto-PGF-type compounds are transformed according to the procedure of Example 26 to the corresponding 13,14-didehydro-PGF-type compound. Accordingly, each of the various 13,14-didehydro-PGF.sub.α-type compounds disclosed herein is prepared according to the procedure of Example 26, by selection of the appropriate PGF.sub.α-type starting material.
EXAMPLE 27
15-Methyl-13,14-didehydro-PGE 2 , methyl ester (Formula CLXXXII: R 1 and R 5 are methyl, R 3 and R 4 of the L 1 moiety and R 6 of the M 1 moiety are all hydrogen, R 7 is n-butyl, R 8 is hydroxy, Y 1 is --C.tbd.C--, and Z 1 is cis-CH=CH-(CH 2 ) 3 -) or its 15-epimer.
Refer to Chart P and R.
A. A solution of 15-methyl-13,14-didehydro-PGF 2 .sub.α, methyl ester (Example 26, 0.142 g.), in acetone (18 ml.) at -45° C. is treated with trimethylsilyldiethylamine (0.6 ml.). After 2.5 hours additional reagent (2.1 ml.) is added and the reaction is continued for 5 hours. The resulting mixture is then diluted with pre-cooled diethyl ether and partitioned with aqueous sodium bicarbonate solution. The organic layer is then dried and evaporated to a yellow oil (15-methyl-13,14-didehydro-PGF 2 .sub.α, methyl ester, 11-(trimethylsilyl ether).
B. The oil obtained in part A is thereafter dissolved in methylene chloride (10 ml.) and thereafter added to a solution of CrO 3 (0.26 g.), methylene chloride (20 ml.), and pyridine (0.4 ml.) at 0° C. This oxidation mixture is then vigorously agitated at 0° C. for 5 minutes and thereafter at ambient temperature for 10 minutes. The resulting suspension is then filtered through silica gel, with the combined filtrate and methylene chloride components being thereafter evaporated to yield 0.103 g. of 15-methyl-13,14-didehydro-PGE 2 , methyl ester, 11-trimethylsilylether (a formula CLXXIII compound).
C. Crude reaction product of part B above in methanol (20 ml.) is treated with water (10 ml.) and acetic acid (1 ml.) and reacted for 5 minutes at 0° C. and thereafter stirred for 10 minutes at ambient temperature. The reaction is then diluted with diethyl ether and partitioned with 0.2 M sodium bisulfate. The organic layer is then washed with sodium chloride and sodium bicarbonate solutions, dried, and evaporated to yield 0.082 g. of crude title product.
Following the procedure described above, the corresponding 15-epimer is obtained.
For 15-methyl-13,14-didehydro-PGE 2 , methyl ester, the mass spectrum shows base peak absorption at 407.2981 and other peaks at 522, 491, 451, 432, 361, 307, 277, and 187. For the 15-epimer, NMR absorptions are observed at 0.8-1.1, 1.1-3.2, 1.48, 3.68, 4.1-4.7, and 5.3-5.6 δ. The mass spectrum shows base peak absorption at 507.2981, 522, 491, 451, 432, 361, 307, 277, and 187. Characteristic infrared absorptions are observed at 3300, 2257, and 1740 cm..sup. -1 .
Following the procedure of Example 27, the various 13,14-didehydro-PGF-type compounds described following Example 26 are transformed to corresponding 13,14-didehydro-PGE-type compounds.
EXAMPLE 28
15-Methyl-13,14-didehydro-PGF 1 .sub.α, methyl ester, or its 15-epimer
Refer to Charts L and R.
A. A solution of 8.5 g. of PGF 1 .sub.α, methyl ester in dioxane (60 ml.) is treated with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (6.8 g.). The reaction proceeds for 21 hours and thereafter the suspension so formed is filtered, the filter cake being washed with dioxane and the combined filtrate and wash concentrated under reduced pressure. The residue is triturated with methylene chloride, filtered, and the solvent removed to yield 11.6 g., of crude 15-keto-PGF 1 .sub.α, methyl ester. Crude product is chromatographed on silica gel (450 g.), eluting with hexane and ethyl acetate (1:1). Pure compound (7.04 g.) is thereby obtained. NMR absorptions are observed at 0.89, 1.05-2.05, 2.05-2.75, 3.20-3.8, 3.67, 6.13, and 6.76 δ.
B. A solution of the reaction product of part A (7.07 g.) in pyridine (40 ml.) is treated with benzoyl chloride (6.3 ml.) and the reaction is allowed to proceed to ambient temperature for 3 hours. The resulting mixture is then diluted with ice water and extracted with methylene chloride. The methylene chloride extract is washed with solutions of ice cold dilute sulfuric acid, sodium bicarbonate, and sodium chloride. The washed extract is then dried and evaporated to yield 11.4 g. of a viscous oil. This oil is chromatographed on silica gel (200 g.) and pure product is obtained diluting with hexane in ethyl acetate (85:15). Accordingly, there is recovered pure 15-keto-9,11-dibenzoyl PGF 1 .sub.α, methyl ester (10.76 g.). NMR absorptions are observed at 0.89, 1.5-1.80, 2.0-2.3, 2.3-2.7, 3.63, 5.1-5.65, 6.26, 6.92, 7.2-7.7, and 7.8-8.2. δ.
C. A solution of the reaction product of part B (4.77 g.) in carbon tetrachloride (20 ml.) is treated dropwise with a solution of bromine (8.3 mmol.) in tetrachloroethane (30 ml.). Coloration is observed to disappear in 10 minutes. The solvent is then removed under reduced pressure to yield 5.0 g. of 13,14-dibromo-9,11-dibenzoyl-15keto PGF 1 .sub.α, methyl ester. NMR absorptions are observed at 0.9, 1.10-2.0, 2.0-3.3, 3.65, 4.4-4.95, 5.08, 5.45-5.85, 7.10-7.8, and 7.9-8.2 δ.
D. The reaction product of part C (2.56 g.) in pyridine (18 ml. is heated at 90°-95° C. for 1 hour. Thereafter the resulting dark green solution is diluted with methylene chloride, washed with ice cold 10 percent sulfuric acid, 5 percent sodium bicarbonate, and 5 percent sodium chloride solutions, dried, and evaporated. This process is then repeated for 2 additional runs and 9.0 g. of crude product is thereby recovered. Crude product is chromatographed on silica gel (210 g.), eluting with hexane and ethyl acetate (85:15). Thereby 5.5 g. of pure 14-bromo-9,11-dibenzoyl-15-keto-PGF 1 .sub.α, methyl ester is prepared. NMR absorptions are observed at 0.92, 1.1-2.0, 2.0-2.6, 2.6-3.1, 3.64, 5.1-5.7, 7.12, 7.2-7.7, and 7.8-8.7 δ.
E. A solution of the reaction product of part D above (0.43 g.) in tetrahydrofuran (15 ml.) is cooled to -78° C. and treated with ethereal methyl magnesium bromide (1.6 ml.) in tetrahydrofuran (10 ml.). After 3.5 hours the reaction mixture thereby obtained is poured with stirring into a cold mixture of diethyl ether and saturated ammonium chloride. The combined ethereal extracts are then washed with sodium chloride, dried and evaporated to yield 0.43 g. of crude (15RS)-15-methyl-14-bromo-9,11-dibenzoyl-PGF 1 .sub.α, methyl ester. Chromatographing on silica gel (25 g.), eluting with benzene in acetone (97:3) yields 0.280 g. of pure product. NMR absorptions are observed 0.83, 1.0-2.0, 1.47, 2.0-3.4, 3.63, 5.0-5.8, 6.13, 7.2-7.7, and 7.8-8.2 δ.
F. A solution of the reaction product of part E above (0.28 g.) in methanol (15 ml.) is treated with potassium carbonate (0.1 g.). The solution is stirred for 24 hours, thereafter being concentrated under reduced pressure, diluted with sodium chloride solution and extracted with ethyl acetate. Thereby, 0.197 g. of crude deacylated product is obtained. This crude product (0.19 g.) is then chromatographed on silica gel (25 g.) eluting with methylene chloride in acetone (85:15). Thereby 43 mg. of 14-bromo-15-methyl-PGF 1 .sub.α, methyl ester, and 40 mg. of 15-epi-14-bromo-15-methyl-PGF 1 .sub.α, methyl ester is obtained. For the (15S) product NMR absorptions are observed at 0.88, 1.10-2.1, 1.45, 2.1-2.7, 3.67, 3.8-4.4, and 5.92 δ. Mass spectrum shows peaks at 426, 395, and 372. For the 15-epimeric product NMR absorptions are observed at 0.88, 1.10-2.1, 1.45, 2.1-2.5, 2.5-3.3, 3.67, 3.8-4.4, and 5.97 δ. The mass spectrum shows peaks at 408 and 329.
G. A solution of potassium t-butoxide (0.37 g.) in tert-butanol (15 ml.) is treated with the reaction product of part F above (0.36 g.). After 3.5 hours the reaction mixture is diluted with diethyl ether and one percent aqueous potassium bisulfate is added. The aqueous phase is extracted with diethyl ether and benzene solutions and the combined organic extracts washed with brine, dried, and evaporated to yield 0.35 g. of crude product. The crude product is then purified on silica gel eluting with 40 percent ethyl acetate in benzene. Thereby 78 mg. of 15-methyl-13,14-didehydro-PGF 2 .sub.α is obtained.
Esterification of the product of the preceeding paragraph with diazomethane and thereafter chromatographing on silica gel, eluting with 12 percent acetone in methylene chloride yields 38 mg. of pure title product. The melting point is 50° C. The mass spectrum shows peaks at 598, 583, 527, 508, 469, 411, 217, and 187. Characteristic infrared absorptions are observed at 1740 and 2220.
Following the procedure of part G above 0.362 g. of 15-epi-15-methyl-14-bromo-PGF 1 .sub.α, methyl ester is transformed to 30 mg. of the 15-epimeric title product. NMR absorptions are observed at 0.9, 1.45, 2.1-2.4, 3.67, and 4.0-4.4 δ. The mass spectrum shows peaks at 598, 583, 508, 493, 477, 469, 411, 217, and 187. Characteristic infrared absorptions are observed at 1740 and 2240 cm. - 1 .
EXAMPLE 29
13,14-Didehydro-PGF 1 .sub.α, methyl ester or its 15-epimer
A. Sodium borohydride (0.44 g.) in methanol (30 ml.) at -35° C. is treated with a solution of the reaction product of Example 28, part D (5.04 g.) and methanol. The solution is stirred for 20 minutes, quenched with acetic acid (20 ml.), diluted with diethyl ether, and ice cold 0.2 M sulfuric acid is added. The combined organic extracts are washed with sodium bicarbonate and saline solutions, dried, and evaporated. The crude residue, 14-bromo-(15-RS)-9,11-dibenzoyl-PGF 1 .sub.α, methyl ester (5.0 g.) is used without further purification. NMR absorptions are observed at 0.7-1.0, 1.0-1.9, 1.9-2.3, 2.3-3.3, 3.63, 3.9-4.3, 5.0-5.6, 6.02, 7.2-7.7, and 7.2-8.2 δ.
B. A solution of the reaction product of part A above (5.0 g.) in methanol (35 ml.) is treated with potassium carbonate (1.5 g.) and agitated for 20 hours. The resulting suspension is then concentrated under reduced pressure, diluted with water, and extracted with ethyl acetate. Drying and evaporation of solvent yields 4.52 g. of crude epimerically mixed deacylated product. The aqueous phase above is acidified and extracted with ethyl acetate to yield 0.45 g. of the free acid of the above epimerically mixed acylated product. These acids are esterified with excess ethereal diazomethane and the combined methyl ester fractions are combined on silica gel eluting with methylene chloride and acetone (7:3) yielding 1.38 g. of 14-bromo-PGF 1 .sub.α, methyl ester and 1.23 g. of 15-epi-14-bromo-PGF 1 .sub.α, methyl ester. For the (15S) compound NMR absorptions are observed at 0.7-1.1, 1.1-2.0, 2.0-2.6, 2.6-3.5, 3.68, 3.75, 4.4, and 5.85 δ. The mass spectrum shows peaks at 414, 412, 360, 358, 351, 333, 279, and 278.
For the 15-epimeric product NMR absorptions are observed at 0.7-1.10, 1.1-2.0, 2.0-2.5, 2.5-3.5, 3.68, 3.8-4.5, and 5.88 δ. The mass spectrum shows peaks at 360, 258, 333, 279, and 278.
C. A suspension of 50 percent sodium hydride (0.7 g.) in dimethylsulfoxide (10 ml.) is treated with tert-butanol (1.3 ml.) and stirred until the resulting effervescence is ceased. A solution of the reaction product of part B above (1.38 g.) in dimethylsulfoxide (15 ml.) is added. After 20 hours the reaction is diluted with benzene and diethyl ether (1:1), and ice cold potassium bisulfate in water is added. The layers are separated and combined. The organic extracts are washed with a sodium chloride solution, dried, and evaporated. The residue is esterified with diazomethane. The resulting crude ester product (1.13 g.) is chromatographed on silica gel and the product eluted with methylene chloride in acetone (7:3). Thereby 0.61 g. of pure title product is obtained. melting point is 68° C. NMR absorptions are observed at 0.90, 1.1-2.0, 2.0-3.0, 3.0-3.9, 3.68, and 4.0-4.45 δ. Characteristic infrared absorptions are observed at 1740, 2250, and 3200 to 3600 cm. - 1 . Mass spectrum shows peaks at 322, 319, 306, 297, 295, 294, 279, 278, 276, 250, and 222.
Following the procedure of Example 29, 1.23 g. of 15-epi-14-bromo-PGF 1 .sub.α, methyl ester is transformed to 0.53 g. of 15-epi-13,14-didehydro-PGF 1 .sub.α, methyl ester. NMR absorptions are observed 0.90, 1.1-2.0, 2.0-3.4, 3.68, and 3.9-4.7 δ. Characteristic infrared absorptions are observed at 1740, 2250, and 3450. The mass spectrum shows peaks at 350, 337, 332, 319, 306, 297, 295, 294, 279, 278, 276, 250, and 222.
EXAMPLE 30
13,14-Didehydro-PGE 1 , methyl ester or its 15-epimer.
A. A solution of 13,14-didehydro-PGF 1 .sub.α, methyl ester (Example 29, 0.22 g.) in acetone (18 ml.) at -45° C. is treated with trimethylsilyldiethylamine (0.8 ml.) and the resulting mixture stirred for 3.5 hours. Additional silylating agent (0.8 ml.) is added. After 45 minutes the reaction is quenched by sodium bicarbonate solution and extracted with diethyl ether. Drying and evaporation of solvent yields 0.34 g. of crude 13,14-didehydro-PGF 1 .sub.α, methyl ester, 11,15-bis(trimethylsilyl ether).
B. The reaction product of part A (0.6 g.) in methylene chloride (25 ml.) at 0° C. is treated with chromium trioxide (0.5 g.) methylene chloride (40 ml.) and pyridine (0.8 ml.). The oxidation conditions are then maintained (0° C.) for 5 minutes and thereafter the temperature is allowed to warm to ambient temperature for an additional 10 minutes. The resulting mixture is then diluted with methylene chloride, and filtered through silica gel. The resulting eluant is then evaporated to yield 0.41 g. of crude 13,14-didehydro-PGF 1 , methyl ester, 11,15-bis(trimethylsilyl ether.).
C. The product of part B above is combined with a mixture of methanol water and acetic acid (20:10:1, 31 ml.). The reaction is allowed to proceed at 0° C. for 5 minutes and thereafter at ambient temperature for 15 minutes. The resulting product is then diluted with water and extracted with diethyl ether. The combined ethereal extracts are then washed with sodium bicarbonate and brine and dried and evaporated to yield 0.33 g. of crude title product. This crude product is then chromatographed on 25 g. of silica gel eluting with methylene chloride in acetone (9:1) yielding 80 ml. of pure 13,14-didehydro-PGE 1 , methyl ester. Melting point is 46° C. characteristic 0.9, 1.1-2.05, 2.05-3.4, 3.67, and 4.0-4.6 δ. The mass spectrum shows absorptions at 348, 320, 319, 295, 292, and 263. The infrared absorption spectrum shows characteristic absorptions at 1675, 1740, 2220, and 3400 cm. - 1 .
Following the procedure of Example 30, parts A, B, and C, 130 mg. of 15-epi-13,14-didehydro-PGF 1 .sub.α, methyl ester is transformed to 26.5 mg. of 15-epi title product. Characteristic infrared absorptions are observed at 1740, 2225, and 3450 cm. - 1 . The mass spectrum shows peaks at 348, 320, 319, 317, 295, 292, and 263.
EXAMPLE 31
13,14-Didehydro-PGF 1 .sub.α or its 15-epimer
Potassium t-butoxide (6.79 g.) in tert-butanol (45 ml.) and methanol (8 ml.) is treated with 14-bromo-PGF 1 .sub.α (3.02 g., see Example 29) and the reaction is allowed to proceed for 25 hours. The resulting reaction mixture is then diluted with diethyl ether, washed with ice cold 8 percent phosphoric acid, and the phases are separated. The aqueous phase is then extracted with benzene, and thereafter extracted with ethyl acetate. The combined organic extracts are then washed with a sodium chloride solution, dried, and evaporated to yield 2.86 g. of title product. The melting point is 74°-75° C. The mass spectrum shows base peak absorption at 642.3961 and other peaks at 627, 571, 552, 537, 481, and 436. Characteristic NMR absorptions are observed at 3150 to 3525, 2700, 2220, 1710, and 1680.
Following the procedure of the preceding paragraph, but using as starting material 15-epi-14-bromo-PGF 1 .sub.α (1.84 g.) there is prepared 15-epi-13,14-didehydro-PGF 1 .sub.α (1.46 g.). The melting point is 95°-96° C. NMR absorptions are observed at 0.8-1.1, 1.1-1.9, 2.0-2.8, and 3.9-4.7 δ. The mass spectrum shows base peak absorptions at 642. 4021 and other peaks at 627, 571, 552, 537, 481, and 217. The infrared absorption spectrum shows characteristic absorptions at 3150 to 3300, 2700, 2220, 1725, and 1700 cm - 1 .
EXAMPLE 32
13,14-Didehydro-16-phenoxy-17,18,19,20-tetranor-8β,12α-PGF 2 .sub.β, methyl ester (Formula CXLVI: R 1 is methyl, R 2 and R 3 of the L 1 moiety and R 5 and R 6 of the M 1 moiety are hydrogen, R 7 is phenoxy, Y 2 is --C.tbd.C--, Z 2 is cis--CH=CH--CH 2 --(CH 2 ) 3 --CH 2 --, R 8 is hydroxy, and M 18 is ##STR151##
Refer to Chart M.
A. To a well stirred mixture of 15.2 g. of a 77 percent sodium hydride dispersion in mineral oil in 2 l. of tetrahydrofuran under a nitrogen atmosphere at 0° C. is added a solution of 92.9 g. of dimethyl-2-oxo-3-phenoxypropyl phosphonate and 220 ml. of tetrahydrofuran. After stirring at 0° for 5 minutes the resulting ylide solution is then stirred at ambient temperature for 75 minutes, thereafter being cooled at 0° C. Into the ylide solution is decanted 3β-benzoyloxy-5β-hydroxy-2α-carboxaldehyde-1β-cyclopentaneacetic acid γ lactone. The resulting mixture is then stirred at ambient temperature for 24 hours. The reaction is thereafter quenched by addition of 2 l. of 2M sodium bisulfate and ice. The aqueous mixture is then extracted well with chloroform. The organic extracts are then combined, washed with water, and saturated with sodium bicarbonate and brine, dried over sodium sulfate, and evaporated to yield a dark oil. This oil is then chromatographed on 2 kg. of silica gel packed in 25 percent ethyl acetate and Skellysolve B. Eluting with 4 l. of 75 percent ethyl acetate in Skellysolve B yields 3β-benzoyloxy-5β-hydroxy-2α-(3-oxo-4-phenoxy-trans-1-butenyl)-1β-cyclopentaneacetic acid γ lactone.
B. Following the procedure of Example 4, part B, the reaction product of part A of this example is transformed to 3β-benzoyloxy-5β-hydroxy-2α-(2-chloro-3-oxo-4-phenoxytrans-1-butenyl)-1β-cyclopentaneacetic acid γ lactone.
C. To the stirred mixture of 2.3 g. of sodium borohydride in 213 ml. of methanol at -20° C. under nitrogen atmosphere is added dropwise 17.7 g. of the reaction product of part B above in 67 ml. of methanol and 200 ml. of tetrahydrofuran. After 1 hour, the resulting mixture is quenched at -20° C. by slow addition of 11 ml. of acetic acid. The resulting solution is then allowed to warm to ambient temperature and diluted with ethyl acetate and washed with 2 M sodium bisulfate, water, and thereafter saturated with sodium bicarbonate and brine, dried over sodium sulfate, and evaporated to yield an oil. This oil containing a mixture of epimers is separated employing high pressure liquid chromatography on a 250 g. column eluting with 10 percent acetone in methylene chloride at 75 pounds per square inch. Pure (15R) and (15S) epimers of 3β-benzoyloxy-5β-hydroxy-2α-(2-chloro-3-hydroxy-4-phenoxy-trans-1-butenyl)-1β -cyclopentaneacetic acid γ lactone.
D. The reaction product of part C (6.8 g.) 10.8 g. of dihydropyran and 0.7 g. of pyridine hydrochloride in 93 ml. of methylene chloride is stirred at ambient temperature for 16 hours. The resulting solution is then filtered through silica gel washing well with ethyl acetate. Evaporation of the filtrate yields 3β-benzoyloxy-5β-hydroxy-2α-(2-chloro-3α-tetrahydropyranyloxy-4-phenoxy-trans-1-butenyl)-1β-cyclopentaneacetic acid γ lactone.
E. The reaction product of part D (8.3 g.) in 167 ml. of dry methanol at ambient temperature under a nitrogen atmosphere is added to 16.7 ml. of a 25 percent solution of sodium methoxide in methanol. After 1 hour the resulting reaction mixture is quenched by addition of 10 ml. of acetic acid. The resulting solution is then evaporated cautiously under reduced pressure. The residue is then cautiously dissolved in saturated sodium bicarbonate and methyl acetate. After equilibration the aqueous phase is separated and extracted well with ethyl acetate. The organic extracts are then combined, washed with brine, dried over sodium sulfate, and evaporated to yield 3β,5β-dihydroxy-2α-(2-chloro-3α-tetrahydropyranyloxy-4-phenoxy-trans-1-butenyl)-1β-cyclopentaneacetic acid γ lactone.
F. A solution of the reaction product of step E (6.8 g.) 6.1 g. of tosyl chloride and 160 ml. of dry pyridine is stirred at 50° C. under a nitrogen atmosphere. After 4 days the resulting solution is diluted with ice and ethyl acetate. To the resulting mixture is added 1 l. of 2M sodium bisulfate in small portions with frequent equilibration. The resulting mixture is then extracted well with ethyl acetate and the organic extracts are combined, washed with water, saturated with sodium bicarbonate and brine, dried over sodium sulfate, evaporated, and azeotroped with benzene to yield 3β-tosyloxy-5β-hydroxy-2α-(2-chloro-3α-tetrahydropyranyloxy-4-phenoxy-trans-1-butenyl)-1β-cyclopentaneacetic acid γ lactone.
G. A mixture of the reaction product of part F (4.8 g.), 8.2 g. of sodium benzoate, in 194 ml. of dimethylsulfoxide is stirred under a nitrogen atmosphere at 80°-85° C. After 3 hours the resulting solution is diluted with ice and diethyl ether. After equilibration the aqueous phase is extracted well with diethyl ether. The organic extracts are then combined, washed with saturated sodium bicarbonate and brine, dried over sodium sulfate, and evaporated to yield 3α-benzoyloxy-5β-hydroxy-2α -(2-chloro-3'α4-phenoxy-trans-1-butenyl)-1β-cyclopentaneacetic acid γ lactone, 3'-tetrahydropyranyl ether.
H. To a stirred solution of the reaction product of part G (3.8 g.) in 77 ml. of dry methanol at ambient temperature under a nitrogen atmosphere is added 7.7 ml. of sodium methoxide in methanol. After 45 minutes the reaction is quenched by addition of 4.6 ml. of acetic acid. The solution is then cautiously evaporated under reduced pressure and the residue cautiously dissolved in saturated sodium bicarbonate and ethyl acetate. After equilibration the aqueous phase is separated and extracted with ethyl acetate. Organic extracts are then combined, washed with brine, dried over sodium sulfate, and evaporated to yield 3α,5β-dihydroxy-2α-(2-chloro-3'α-hydroxy-4-phenoxy-trans-1-butenyl)-1β-cyclopentaneacetic acid γ lactone, 3-tetrahydropyranyl ether.
I. A solution of the reaction product of part H (2.1 g.) 3.1 g. of dihydropyran, and 0.2 g. of pyridine hydrochloride in 30 ml. of methylene chloride is stirred at ambient temperature for 17 hours. The resulting solution is then filtered through silica gel washing well with ethyl acetate. Evaporation of the filtrate yields 3α,5β-dihydroxy-2α-(2-chloro-3α-hydroxy-4-phenoxy-trans-1-butenyl)-1β-cyclopentaneacetic acid γ lactone, bis-(tetrahydropyranyl ether).
J. The reaction product of part I is transformed to 3α,5β-dihydroxy-2α-(2-chloro-3αhydroxy-4-phenoxy-trans-1-butenyl)-1β-cyclopentaneacetaldehyde γ lactol bis-tetrahydropyranyl ether following the procedure of Example 8, part C. Thereafter, this compound is transformed to 14-chloro-16-phenoxy-17,18,19,20-tetranor-8β,12α-PGF 2 .sub.β, methyl ester, 11,15-bis(tetrahydropyranyl ether) following the procedure of Example 13.
K. A solution of 0.3 g. of the reaction product of part J in 20 ml. of acetic acid, water, and tetrahydrofuran (20:10:3) is heated at 40° C. for 3 hours. The resulting solution is then cooled to ambient temperature and diluted with 20 ml. of water and freeze dried to yield 14-chloro-16-phenoxy-17,18,19,20-tetranor-8β12α-PGF 2 .sub..beta., methyl ester.
L. The reaction product of part K (0.04 g.) and dimethylsulfoxide (10 ml.) is treated with potassium tertbutoxide (40 mg.) and reacted for 28 hours at ambient temperature. The resulting solution is then diluted with diethyl ether and poured into a mixture of ice cold potassium bisulfate and diethyl ether. The resulting mixture is then diluted with benzene, partitioned, washed with a sodium chloride solution, dried, and evaporated. The residue is chromatographed and esterified with excess ethereal diazomethane. The crude methyl ester product is chromatographed on silica gel eluting with methylene chloride in acetone (75:35), yielding pure title product.
Following the procedure of Example 32, the various 8β,12α-PGF 2 .sub.β -type compounds of Chart M are prepared. Further following the procedure of Chart M the various other PGF, PGE, or PGA-type compounds of Chart M are prepared. Further, following the procedure of Example 32, the various 11-deoxy-PGF- or PGE- compounds are prepared.
EXAMPLE 33
3,7-inter-m-Phenylene-4,5,6-trinor-13,14-didehydro-8β,12α-PGF.sub.1.sub.α, methyl ester (Formula CLXVII: R 1 is methyl, Z 1 is ##STR152##
M 18 is ##STR153##
Y 2 is --C.tbd.C--, R 3 and R 4 of the L 1 moiety and R 5 and R 6 of the M 1 moiety are all hydrogen, and R 7 is n-butyl).
Refer to Chart O.
A. Following the procedure of Example 25, the enantiomer of 3,7-inter-m-phenylene-4,5,6-trinor-15-epi-PGF 1 .sub.α is prepared from ent starting material. Thereafter, following the procedure of Examples 26 and 27 there is prepared the enantiomer of 3,7-inter-m-phenylene-4,5,6-trinor-14-chloro-15-epi-PGF 1 .sub.α.
B. Thereafter, following the procedure of Example 22, there is prepared 3,7-inter-m-phenylene-4,5,6-trinor-8β,12α-PGA 2 , a compound according to formula CLXI.
C. The reaction product of part B in 5 ml. of methanol is treated with stirring at -25° C. under nitrogen with a solution of 0.7 ml. of 30 percent aqueous hydrogen peroxide and 0.35 ml. of a 1N sodium hydroxide solution. After 1 hour there is added a 2N hydrochloric acid solution dropwise, thereby adjusting pH to 5 or 6. The resulting mixture is then diluted with brine and extracted with diethyl ether. The organic phase is washed with a sodium bicarbonate and brine, dried over sodium sulfate, and evaporated to yield 3,7-inter-m-phenylene-4,5,6-trinor-14-chloro-8β,12α-PGA 2 , 10,11-epoxide.
D. A mixture of the reaction product of part C (0.20 g.), aluminum amalgam (0.16 g.), 8 ml. of diethyl ether, 1.6 ml. of methanol, and 4 drops of water is stirred at ambient temperature for 2 days. The resulting mixture is then filtered and the filtrate concentrated to yield the title compound as a mixture of 11α and 11β isomers. Separation by silica gel chromatography eluting with ethyl acetate in Skellysolve B yields pure 11α- product, 3,7-inter-m-phenylene-4,5,6-trinor-14-chloro-8β,12α-PGE 2 .
The aluminum amalgam is prepared as follows:
Granular aluminum metal (50 g.) is added to a solution of mercuric chloride (50 g.) in 2 l. of water. The mixture is swirled until hydrogen gas evolution starts to become vigorous (about 30 minutes). Then most of the aqueous solution is decanted and the rest removed by rapid filtration. The amalgamated aluminum is then washed rapidly and successively with two 200 ml. portions of methanol and two 200 ml. portions of anhydrous diethyl ether. The amalgamated aluminum is then covered with anhydrous diethyl ether until ready for use.
E. Following the procedure of Example 21, the product of part D is transformed to 3,7-inter-m-phenylene-4,5,6-trinor-14-chloro-8β,12α-PGF 1 .sub.α. Thereafter, following the dehydrohalogenation procedure of Example 32, there is prepared the title product.
Following the procedure of Example 33, each of the various 8β,12α-PGA-type compounds described herein is transformed to the corresponding 8β,12α-PGF or PGE-type compound.
EXAMPLE 34
17-Phenyl-18,19,20-trinor-13,14-didehydro-11-deoxy-PGE 2 (Formula CLVI: R 1 is hydrogen, R 3 and R 4 of the L 1 moiety and R 5 and R 6 of the M 1 moiety are all hydrogen, R 7 is benzyl, Y 2 is --C.tbd.C--, and Z 1 is cis--CH=CH--(CH 2 ) 3 -).
Refer to Chart N.
A. Employing 2,3-dichloro-5,6-dicyano-benzoquinone, 15-keto-17-phenoyl-18,19,20-trino-PGF 2 .sub.α is prepared from 17-phenyl-18,19,20-trinor-PGF 2 .sub.α.
B. Thereafter following the procedure of Examples 26 and 27 the reaction product of part A is transformed to 13,14-didehydro-17-phenyl-18,19,20-trinor-PGE 2 , methyl ester.
C. Following the procedure of Example 22, the reaction product of part B is transformed to 13,14-didehydro- 17-phenyl-18,19,20-trinor-PGA 2 , methyl ester.
D. To a solution of the reaction product of part C above (0.77 g.) in pyridine (5 ml.) is added acetic anhydride (1.5 ml.). The mixture is then stirred for 4 hours under nitrogen and thereafter water (50 ml.) is added. The resulting mixture is then stirred for 55 minutes and thereafter extracted with ethyl acetate. The combined organic extracts are washed, dried, and concentrated to yield a formula CLIII compound, 13,14-didehydro-17-phenyl-18,19,20-trinor-PGA 2 , 15-acetate.
E. To a stirred solution of the reaction product of step D dissolved in methanol (25 ml.) at -25° C. under a nitrogen atmosphere, a solution of sodium borohydride (2 g.) in 5 ml. of water and 20 ml. of methanol is added. This resulting mixture is then stirred at -20° C. for 20 minutes and 3.5 ml. of acetic acid is thereafter cautiously added. The resulting mixture is concentrated and thereafter 50 ml. of water is added. The pH of the mixture is then adjusted to about 3 by addition of citric acid. The mixture is then extracted with dichloromethane and the combined organic extracts are washed with water and brine, dried, and concentrated to yield a formula CLIV compound.
F. To a solution of the reaction product of part E (dissolved in acetone, 50 ml.) at -20° C., there is added dropwise with stirring over a one minute period the Jones reagent (1.5 ml.). This mixture is stirred at -20° C. for 20 minutes and thereafter. 1.5 ml. of isopropanol is added and the resulting mixture is stirred at -20° C. for 10 minutes. This mixture is then diluted with 50 ml. of water and extracted with diethyl ether. The combined ethereal extracts are washed with water and brine, dried, and concentrated. The residue is then chromatographed on silica gel, eluting with acetone and methylene chloride. Those fractions containing the 15-acetate, methyl ester of the title compound are combined and concentrated.
G. To a solution of the reaction product of step F dissolved in methanol (15 ml.), there is added sodium hydroxide (0.5 g.) in 3 ml. of water and the resulting mixture is stirred at 25° C. for 17 hours. This mixture is then acidified with 10 ml. of 3N hydrochloric acid and thereafter concentrated to an aqueous residue. The residue is diluted with 25 ml. of water and extracted with diethyl ether. The combined ethereal extracts are washed with brine, dried, and concentrated. The residue is chromatographed on acid washed silica gel, eluting with ethyl acetate and hexane. Those fractions shown to contain pure title compound are combined.
Following the procedure of Example 34, each of the PGF-type compounds described herein is transformed to the corresponding 13,14-didehydro-PGA-type compound, which is in turn transformed to each of the various 13,14-didehydro-11-deoxy-PG-type compounds described herein.
EXAMPLE 35
13,14-Didehydro-16,16-dimethyl-PGF 2 .sub.α, methyl ester
Refer to Chart R.
A solution of the reaction product of Example 16 in dimethyl sulfoxide (10 ml.) is treated with potassium t-butoxide (40 mg.) and reacted for 28 hours at ambient temperature. The resulting solution is then diluted with diethyl ether and poured into a mixture of ice cold potassium bisulfate and diethyl ether. This mixture is then diluted with benzene partitioned, washed with a sodium chloride solution, dried, and evaporated. The residue is then esterified with excess ethereal diazomethane. The crude methyl ester is then chromatographed on silica gel (10g.) eluting with methylene chloride and acetone (75:35). Thereby, 0.016g. of title product is recovered. A characteristic IR absorption (--C.tbd.C--) is observed at 2250 cm..sup. -1 . The mass spectrum shows peaks at 327, 320, 304, 303, 302, 295, 284, 263, 247, 245, 235, 227, and 57.
Following the procedure of Example 35, each of the various 14-halo-11-deoxy-PGF.sub.α- or PGF.sub.α-type compounds described above is transformed to a corresponding 13,14-didehydro-11-deoxy-PGF.sub.α- or PGF.sub.α-type product.
Further, following the procedures of the above Examples each of the various 13,14-didehydro-11-deoxy-PGF.sub.α- or PGF.sub.α-type products is transformed to a corresponding 13,14-didehydro-11-deoxy-PGE- or PGE-type product.
Further, following the procedure of the above Examples each of the various 13,14-didehydro-11-deoxy-PGE- or PGE-type products is transformed to the corresponding 13,14-didehydro-11-deoxy-PGF.sub.β- or 11-deoxy-PGF.sub.β-type products.
Further, following the procedure of the above Examples each of the various 13,14-didehydro-PGE-type products is transformed to the corresponding 13,14-didehydro-PGA- or PGB-type product.
EXAMPLE 36
13,14-Didehydro-PGF 3 .sub.α, 13,14-didehydro-16,16-dimethyl-PGF 3 .sub.α, and 13,14-didehydro-16,16-difluoro-PGF 3 .sub.α.
A. Grignard reagents are prepared by reacting magnesium turnings with 1-bromo-cis-2-pentene; 1-bromo-1,1-dimethyl-cis-2-pentene or 1-iodo-1,1-difluoro-cis-2-pentene. 1-iodo-1,1-difluoro-cis-2-pentene is prepared as follows:
2,2-difluoro-acetic acid is esterified with excess ethereal diazomethane. Thereafter the resulting methyl 2,2-difluoro-acetate is iodinized to methyl 2,2-difluoro-2-iodoacetate by the procedure of Tetrahedron Lett. 3995 (1971) (e.g., addition of lithium diisopropylamine to the starting material, followed by treatment with iodine). This product is then reduced to a corresponding aldehyde 2,2-difluoro-2-iodo-acetaldehyde, employing diisobutyl aluminum hydride at -78° C. This aldehyde is then alkylated by a Wittig alkylation, employing the ylid ethyl triphenylphosphorane, (C 6 H 5 ) 3 P=CH 2 -CH 3 , thereby yielding the title iodide.
B. The Grignard reagent of part A is reacted with 3α-t-butyldimethylsilyloxy-5α-hydroxy-2β-(2-formyl-trans-1-ethenyl)-1α-cyclopentaneacetic acid γ lactone, thereby preparing a corresponding 2β-[(3RS)-3-hydroxy-trans-1-cis-5-octandienyl] compound which is oxidized to a corresponding 3-oxo compound with the Collins reagent.
C. Following the procedures of the above examples the reaction product of step B is transformed to 13,14-didehydro-PGF 3 .sub.α.
Following the procedure of parts B and C above, but using a methyl or fluoro-substituted Grignard reagent, correspondingly 13,14-didehydro-16,16-dimethyl-PGF 3 .sub.α or 13,14-didehydro-16,16-difluoro-PGF 3 .sub.α is prepared.
Following the procedure of the above examples, there are prepared the PGF 3 .sub.α -type compounds or 8β,12α-PGF 3 .sub.α -type compounds of Table A. Further, following the procedure of the above Examples, there are prepared the PGE 3 - or 8β,12α-PGE 3 -; PGF 3 .sub.β - or 8β,12α-PGF 3 .sub.β - or PGA 3 - or 8β,12α-PGA 3 -type compounds corresponding to each of the PGF 3 .sub.α - or 8β,12α-PGF 3 .sub.α -type compounds of Table A. Finally, following the above Examples, there are prepared PGB 3 -type compounds corresponding to each of the PGF 3 .sub.α -type compounds of Table A.
In interpreting these Tables, each formula listed in the Table represents a prostaglandin-type product whose complete name is given by combining the name provided in the respective legends below the formula with the prefix found in the "Name" column in the tubular section of the Tables for each example. ##STR154##
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This invention comprises certain analogs of the prostaglandins in which the double bond between C-13 and C-14 is replaced by a triple bond. Also provided in this invention, are novel chemical processes and novel chemical intermediates useful in the preparation of the above prostaglandin analogs. These prostaglandin analogs exhibit prostaglandin-like activity, and are accordingly useful for the same pharmacological purposes as the prostaglandins. Among these purposes are blood pressure lowering, labor induction at term, reproductive-cycle regulation, gastric antisecretory action, and the like.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to Japanese Patent Application No. 2011-170622, filed Aug. 4, 2011, the disclosure of which is hereby incorporated by reference in its entirety.
BACKGROUND
[0002] The present disclosure relates to a sewing machine that can perform sewing of an embroidery pattern, an embroidery data creation device that creates data for sewing an embroidery pattern, and a non-transitory computer-readable medium that stores an embroidery data creation program.
[0003] A sewing machine is known that can sew an embroidery pattern based on a design that a user has selected. An embroidery data creation device is also known that creates embroidery data for sewing an embroidery pattern. Specifically, the embroidery data creation device is also known that acquires a design that a user has selected. The embroidery data creation device creates embroidery data for sewing the acquired design as an embroidery pattern. The embroidery data creation device can recognize characters in the acquired design and convert them into other characters of a different style. The embroidery data creation device is thus able to create embroidery data for sewing an embroidery pattern of a design that contains the characters of the different style.
SUMMARY
[0004] Demand has arisen to have characters of a particular style acquired in advance by a sewing machine, to have a character string created by combining the acquired characters as the user desires, and to have an embroidery pattern of the character string sewn by the sewing machine. The characters of a particular style may be characters in a handwritten style, for example. The known devices described above are not able to acquire characters of a particular style in advance. Therefore, cases may occur in which the embroidery data for sewing a character string that includes characters of a particular style cannot be created.
[0005] There may also be cases in which, after the embroidery data are created based on a character string that includes characters of a particular style, and that is acquired by the sewing machine as it is the user wants to change only a specific character within the character string to a different character and then sew the embroidery pattern.
[0006] In that case, it may be necessary for the sewing machine to acquire the entire character string once again, even if the greater part of the character string is the same, and to create the embroidery data all over again. Therefore, it may be not always be possible to create the embroidery data and perform the sewing efficiently.
[0007] Various exemplary embodiments of the general principles herein provide a sewing machine that may comprise a processor; and a memory. The memory may be configured to store computer-readable instructions therein, wherein the computer-readable instructions instruct the sewing machine to execute steps comprising acquiring image data including one or more characters, extracting, from acquired image data, one or more character designs with respect to each character included in the acquired image data, wherein the character design represents each character included in the acquired image data, generating embroidery data with respect to each character based on the extracted character design, wherein the embroidery data represents an embroidery pattern in a predetermined size, selecting specific embroidery data, in response to accepting an instruction for specifying character design, from the generated embroidery data corresponding to the specified character design, and generating a signal based on the selected embroidery data, wherein the sewing machine is configured to sew an embroidery pattern represented by the selected embroidery data based on the signal.
[0008] Exemplary embodiments herein provide an apparatus that may comprise a processor and a memory. The memory may be configured to store computer-readable instructions therein, wherein the computer-readable instructions instruct the apparatus to execute steps comprising acquiring image data including one or more characters, extracting, from acquired image data, one or more character designs with respect to each character included in the acquired image data, wherein the character design represents each character included in the acquired image data, and generating embroidery data with respect to each character based on the extracted character design, wherein the embroidery data represents an embroidery pattern in a predetermined size.
[0009] Exemplary embodiments also provide a non-transitory computer readable medium. The non-transitory computer readable medium may store computer readable instructions that, when executed, instruct an apparatus to execute steps comprising acquiring image data including one or more characters, extracting, from acquired image data, one or more character designs with respect to each character included in the acquired image data, wherein the character design represents each character included in the acquired image data, and generating embroidery data with respect to each character based on the extracted character design, wherein the embroidery data represents an embroidery pattern in a predetermined size.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Exemplary embodiments of the present disclosure will be described below in detail with reference to the accompanying drawing in which:
[0011] FIG. 1 is an oblique view of a sewing machine 1 ;
[0012] FIG. 2 is a left side view that shows an area around a needle bar 6 , a sewing needle 7 , a presser bar 91 , and a presser foot 92 ;
[0013] FIG. 3 is a block diagram that shows an electrical configuration of the sewing machine 1 ;
[0014] FIG. 4 is a figure that shows an embroidery pattern 41 of a character “B”;
[0015] FIG. 5 is a flowchart of character acquisition processing;
[0016] FIG. 6 is a flowchart of the character acquisition processing, continued from FIG. 5 ;
[0017] FIG. 7 is a figure that shows an image 50 and characters 51 ;
[0018] FIG. 8 is a figure that shows a binary image 70 and character designs 53 ;
[0019] FIG. 9 is a figure that shows character designs 55 ;
[0020] FIG. 10 is a figure that shows character designs 56 ;
[0021] FIG. 11 is a figure that shows an embroidery pattern 44 of a character “B”;
[0022] FIG. 12 is a flowchart of sewing processing;
[0023] FIG. 13 is a figure that shows an embroidery pattern 58 that has been sewn;
[0024] FIG. 14 is a figure that shows character designs 57 ; and
[0025] FIG. 15 is a figure that shows an embroidery pattern 59 that has been sewn.
DETAILED DESCRIPTION
[0026] Hereinafter, an embodiment will be explained with reference to the drawings. A configuration of a sewing machine 1 will be explained with reference to FIGS. 1 and 2 . In the explanation that follows, the lower right, the upper left, the upper right, and the lower left in FIG. 1 respectively correspond to the front side, the rear side, the right side, and the left side of the sewing machine 1 . A direction in which a bed 11 (described later) extends corresponds to an X-axis direction. A direction that is perpendicular to the X-axis direction and that is parallel to the top face of the bed 11 corresponds to a Y-axis direction.
[0027] As shown in FIG. 1 , the sewing machine 1 includes a bed 11 , a pillar 12 , an arm 13 , and a head 14 . The bed 11 is a base portion of the sewing machine 1 that is longer in the left-right direction. The pillar 12 extends upward from the right end of the bed 11 . The arm 13 extends to the left from the upper end of the pillar 12 such that it is opposite the bed 11 . The head 14 is a portion that is connected to the left end of the arm 13 . A needle plate (not shown in the drawings) is provided in the top face of the bed 11 . A feed dog, a feed mechanism, and a shuttle mechanism (which are not shown in the drawings), and a feed adjustment pulse motor 78 (refer to FIG. 3 ) are provided underneath the needle plate (that is, within the bed 11 ). The feed dog may be driven by the feed mechanism and feed a work cloth by a specified feed amount. The feed amount may be adjusted by the feed adjustment pulse motor 78 .
[0028] An embroidery frame 34 that holds a work cloth 100 can be disposed on the top side of the bed 11 . The embroidery frame 34 may be a known structure that is configured to hold the work cloth 100 by clamping it with an inner frame and an outer frame. An embroidery frame moving device 33 has a known structure that is configured to move the embroidery frame 34 , so it will be explained briefly. The embroidery frame moving device 33 can be removably mounted on the bed 11 . A carriage 35 that extends in the front-rear direction is provided on top of the embroidery frame moving device 33 . A frame holder (not shown in the drawings) on which the embroidery frame 34 can be removably mounted and a Y axis moving mechanism (not shown in the drawings) that is configured to move the frame holder in the front-rear direction (the Y axis direction) are provided in the interior of the carriage 35 . The Y axis moving mechanism may be driven by a Y axis motor 84 (refer to FIG. 3 ).
[0029] An X axis moving mechanism (not shown in the drawings) that is configured to move the carriage 35 in the left-right direction (the X axis direction) is provided inside the embroidery frame moving device 33 . The X axis moving mechanism may be driven by an X axis motor 83 (refer to FIG. 3 ). As the carriage 35 is moved in the left-right direction (the X axis direction), the embroidery frame 34 is moved in the left-right direction (the X axis direction).
[0030] A needle bar 6 (refer to FIG. 2 ) and the shuttle mechanism (not shown in the drawings) may be driven in conjunction with the moving of the embroidery frame 34 in the left-right direction (the X axis direction) and the front-rear direction (the Y axis direction). This causes a sewing needle 7 (refer to FIG. 2 ) that is mounted in the needle bar 6 to sew an embroidery pattern in the work cloth 100 that is held by the embroidery frame 34 . When an ordinary pattern that is not an embroidery pattern is to be sewn, the embroidery frame moving device 33 is removed from the bed 11 . In that state, the sewing is performed as the work cloth is moved by the feed dog.
[0031] A vertically rectangular liquid crystal display (hereinafter called an LCD) 15 is provided in the front face of the pillar 12 . An image may be displayed on the LCD 15 based on image data that includes various types of items, such as commands, illustrations, setting values, messages, and the like. A touch panel 26 is provided on the front face of the LCD 15 . Using a finger or a special touch pen, a user may perform a pressing operation on the touch panel 26 . Hereinafter, this operation is called a panel operation. The touch panel 26 detects a position which is pressed by a finger or a special touch pen etc., and the sewing machine 1 determines the item that corresponds to the detected position. Thus, the sewing machine 1 recognizes the selected item. By performing the panel operation, the user can select a pattern to be sewn or a command to be executed.
[0032] The arm 13 is provided in its top portion with a cover 16 that can be opened and closed. Underneath the cover 16 , that is, approximately in the middle of the arm 13 , a thread container portion 18 is provided that is a recessed portion that may contain a thread spool 20 . A thread spool pin 19 that projects leftward toward the head 14 is provided on an inner side wall on the pillar 12 side of the thread container portion 18 . The thread spool 20 may be mounted in the thread container portion 18 in a state in which the thread spool pin 19 has been inserted into an insertion hole (not shown in the drawings) of the thread spool 20 .
[0033] An upper thread (not shown in the drawings) that is wound around the thread spool 20 may be supplied from the thread spool 20 , through a thread hook portions (not shown in the drawings) that are provided in the head 14 , to the sewing needle 7 that is mounted in the needle bar 6 (refer to FIG. 2 ). The needle bar 6 may be driven by a needle bar up-and-down moving mechanism (not shown in the drawings) that is provided in the head 14 , such that the needle bar 6 moves up and down. The needle bar up-and-down moving mechanism may be driven by a drive shaft (not shown in the drawings) that may be rotationally driven by a sewing machine motor 79 (refer to FIG. 3 ). A presser bar 91 extends downward from the bottom end of the head 14 . A presser foot 92 that presses down on the work cloth 100 may be replaceably mounted on the presser bar 91 . A plurality of operation switches, including a start-and-stop switch 32 , are provided in the lower part of the front face of the arm 13 .
[0034] An electrical configuration of the sewing machine 1 will be explained with reference to FIG. 3 . A control portion 60 of the sewing machine 1 includes a CPU 61 , a ROM 62 , a RAM 63 , an EEPROM 64 , an external access RAM 68 , a card slot 17 , an input interface 65 , and an output interface 66 . These elements are electrically connected to one another by a bus 67 . A plurality of operation switches, including a power supply switch 31 and the start-and-stop switch 32 , are electrically connected to the input interface 65 , as are the touch panel 26 and the like.
[0035] The ROM 62 stores various types of programs for controlling the operation of the sewing machine 1 . The CPU 61 may perform various types of computations and processing in accordance with the programs that are stored in the ROM 62 , temporarily storing various types of data in the RAM 63 . Standard character embroidery data are also stored in the ROM 62 . The standard character embroidery data are data for sewing characters in a standard style as embroidery patterns. The standard character embroidery data may represent an embroidery data of a standard design of a character. Data that indicate needle drop points, which are positions where the sewing needle 7 pierces the work cloth 100 , are also included in the standard character embroidery data. A sewing order, a sewing starting point, and a sewing ending point of an embroidery pattern are also included in the standard character embroidery data. The sewing order, the sewing starting point, and the sewing ending point will be described in detail later. Hereinafter, the sewing order, the sewing starting point, and the sewing ending point are also called setting information. The sewing machine 1 is able to sew characters in the standard style as embroidery patterns, based on the standard character embroidery data.
[0036] The setting information that is included in the standard character embroidery data will be explained with reference to FIG. 4 . FIG. 4 shows an embroidery pattern 41 of the alphabetic character “B”. The embroidery pattern 41 of the alphabetic character “B” in FIG. 4 is an example of an embroidery pattern that is sewn in the work cloth 100 (refer to FIG. 1 ) based on the standard character embroidery data. The embroidery pattern 41 is sewn by causing the sewing needle 7 to pierce the work cloth 100 at the needle drop points in the order that is indicated by arrows 42 , 43 . Information that indicates the sewing will be performed in the directions that are shown by the arrows 42 , 43 and in the order indicated by the arrows 42 , 43 is equivalent to the sewing order. Information that indicates a starting point 421 and an ending point 422 of the arrow 42 is equivalent to the sewing starting point and the sewing ending point, respectively. In the same manner, information that indicates a starting point 431 and an ending point 432 of the arrow 43 is also equivalent to the sewing starting point and the sewing ending point, respectively.
[0037] The setting information, that is, the sewing order, the sewing starting point, and the sewing ending point, have been adjusted such that an embroidered pattern with high quality can be sewn in the work cloth 100 based on the standard character embroidery data. Specific examples will be explained. Value of the setting information is adjusted such that jump stitches and basting occur as little as possible, or to put it another way, such that the character is sewn, to the extent possible, as if it were written as a single continuous line. Thus the high quality of the embroidered pattern may be ensured. This may prevent the occurrence of boundary lines and differences in the sewing direction within the embroidery pattern. The parameters in the setting information are also adjusted such that the sewing starts and stops on the underside of the standard character, to the extent possible. In a case where embroidery patterns of a character string in which a plurality of the standard characters are combined and sewn, this may prevent jump stitches from passing over the embroidered pattern between the embroidered patterns for the individual characters, thereby ensuring the high quality of the embroidered pattern. It may also minimize the amount of jump stitch removal work the user must do.
[0038] As shown in FIG. 3 , a memory card 171 can be inserted into the card slot 17 . The CPU 61 is able to acquire, through the external access RAM 68 , information that is stored in the memory card 171 . In the present embodiment, the user may store in the memory card 171 image data which represents an image that contains at least one character in a desired style, in order for the at least one character in the desired style to be sewn as an embroidery pattern by the sewing machine 1 . The at least one character in the desired style may be a character that is handwritten by the user, a character that is prepared in a font of the user's own devising, or the like. The CPU 61 may acquire the image data that is stored in the memory card 171 . Then the CPU 61 may create embroidery data for sewing, as an embroidery pattern, each of the characters that are contained in the image represented by the image data. The embroidery data may be created based on the setting information that is included in the standard character embroidery data that are stored in the ROM 62 . The method for creating the embroidery data will be described in detail later. The created embroidery data may be stored in the EEPROM 64 .
[0039] Drive circuits 71 to 74 , 85 , and 86 are electrically connected to the output interface 66 . The drive circuit 71 may drive a feed adjustment pulse motor 78 . The drive circuit 72 may drive a sewing machine motor 79 . The drive circuit 73 may drive a swinging pulse motor 80 . The swinging pulse motor 80 may drive a needle bar swinging mechanism (not shown in the drawings) that swings the needle bar 6 . The feed adjustment pulse motor 78 and the swinging pulse motor 80 are not driven during the sewing of the embroidery pattern. The drive circuit 74 may drive the LCD 15 . The drive circuits 85 and 86 may respectively drive the X axis motor 83 and the Y axis motor 84 for moving the embroidery frame 34 .
[0040] Character acquisition processing and sewing processing that are performed by the sewing machine 1 will be explained with reference to FIGS. 5 to 15 . The character acquisition processing is processing that creates an embroidery data based on image data of at least one character that is stored in the memory card 171 . The sewing processing is processing that performs the sewing of an embroidery pattern based on the created embroidery data. Hereinafter, each type of processing will be explained in detail.
[0041] The character acquisition processing will be explained with reference to FIGS. 5 and 6 . The character acquisition processing is started by the launching of a character acquisition processing program that is stored in the ROM 62 , the program being launched in a case where the memory card 171 has been inserted into the card slot 17 . The character acquisition processing in FIGS. 5 and 6 is performed by the executing of the program by the CPU 61 . As shown in FIG. 5 , first, the image data that is stored in the memory card 171 is acquired (Step S 11 ). The acquired image data is stored in the RAM 63 . In the explanation that follows, which references FIGS. 7 to 10 , an example will be used in which image data of an image 50 shown in FIG. 7 is acquired and stored in the RAM 63 . The image 50 contains ten characters 51 (a character 51 A, a character 51 B, a character 51 C, a character 51 D, a character 51 E, a character 51 F, a character 51 G, a character 51 H, a character 51 I, and a character 51 J) that were handwritten by the user. Note that the characters 51 include an Arabic numeral, plus Japanese hiragana and kanji character.
[0042] As shown in FIG. 5 , the image data of the image 50 (refer to FIG. 7 ) that is stored in the RAM 63 is converted into binary image data of a binary image 70 (refer to FIG. 8 ) in order for the characters 51 (refer to FIG. 7 ) that are contained in the image 50 to be recognized (Step S 13 ). Various types of known methods can be used as the method for converting the image data of the image 50 into the binary image data of the image 70 . For example, a method that binarizes according to a threshold value can be used. Other examples of methods that can be used include a random dither method and an error diffusion method. Converting the image data of the image 50 into the binary image data of the image 70 makes the differences in the gray levels clearer between the areas where the characters 51 are and the areas outside the characters 51 , so it makes the characters 51 that are contained in the image 50 easier to recognize.
[0043] The characters 51 that are contained in the binary image 70 (refer to FIG. 8 ) are recognized by using a known character recognition method. The regions in which the characters 51 are respectively drawn in the binary image 70 are specified for each individual character 51 (Step S 15 ). Pattern matching by a superposition technique, for example, can be used as the known character recognition method. A rectangle 52 (refer to FIG. 8 ) is defined that is the smallest rectangle that encloses on all sides the region in which the individual character 51 is drawn. One of the regions in which one of the characters 51 is drawn is extracted from the binary image 70 according to the outline of the defined rectangle 52 , and image data of the extracted region is stored in the RAM 63 (Step S 17 ). Hereinafter, the design that indicates the image data of the extracted individual character will also be called a character design 53 (refer to FIG. 8 ). Note that because the rectangle 52 is the smallest rectangle that encloses on all sides the region in which the individual character 51 is drawn, cases may occur in which the vertical length and the horizontal length of the individual character design 53 are different, as shown in FIG. 8 . As shown in FIG. 5 , a determination is made as to whether the extracting of the character design 53 and storing the image data of the extracted character design 53 in the RAM 63 have been carried out for all of the characters 51 that are contained in the binary image 70 (Step S 19 ). In a case where a characters 51 remains for which the extracting of the character design 53 and its storing in the RAM 63 have not been carried out (NO at Step S 19 ), the processing returns to Step S 17 . The processing at Step S 17 is repeated for the remaining character 51 .
[0044] In a case where the extracting and storing have been completed for all of the characters 51 that are contained in the binary image 70 (YES at Step S 19 ), the image data of the first one of the plurality of character designs 53 that have been stored in the RAM 63 is selected, as shown in FIG. 6 . A character design 55 (refer to FIG. 9 ) is produced by making the lengths of the short sides of the rectangular character design 53 equal to the lengths of the long sides of the character design 53 (Step S 21 ). In other words the character design 55 is produced by redefining the character design 53 in accordance with a square 54 (refer to FIG. 9 ), each of whose sides is equal to the long side of the rectangle 52 that was defined by the processing at Step S 17 . The short sides of the rectangular character design 53 are lengthened equally, either toward the top and bottom or toward the left and right, so the character 51 that is contained in the character design 55 is positioned in the center of the square 54 . The shape of the character 51 that is contained in the character design 53 and the character design 55 is not changed.
[0045] The size of the character design 55 is adjusted. Specifically, in a case where the length of one side of the square 54 that contains the character design 55 is not a specified value, the character design 55 is one of enlarged and shrunk such that the length of one side of the square 54 becomes the specified value (Step S 23 ). The character design 55 whose size has been adjusted is then redefined as a character design 56 (refer to FIG. 10 ). Because the size of the character design 55 is one of enlarged and shrunk, the size of the character 51 that is contained in the character design 55 is also changed accordingly. Thus the character design 56 thus produced has the same size as the other character designs 56 that are respectively produced from all the other character designs 55 . Note that in a case where the length of one side of the square 54 that contains the character design 55 is the specified value, the size of the character design 55 is not changed, and the unchanged character design 55 is redefined as the character design 56 .
[0046] The character 51 that is contained in the character design 56 is recognized by a known character recognition method, and the type of the character 51 is specified (Step S 25 ). Pattern matching by feature extraction, for example, can be used as the known character recognition method. The specified character is compared to a standard character that is sewn according to the standard character embroidery data that are stored in the ROM 62 (Step S 27 ). A determination is made as to whether the standard character embroidery data for a character that is the same as the specified character are stored in the ROM 62 (Step S 29 ). In the present example, a determination is made as to whether the standard character embroidery data are stored in the ROM 62 for a character that is the same as whichever one of the character 51 A, the character 51 B, the character 51 C, the character 51 D, the character 51 E, the character 51 F, the character 51 G, the character 51 H, the character 51 I, and the character 51 J (refer to FIG. 7 ) is currently being processed.
[0047] In a case where the standard character embroidery data for the same character that is the same as the specified character are not stored in the ROM 62 (NO at Step S 29 ), the image data of the character design 56 is converted using a known conversion technology, and the embroidery data for sewing the character design 56 as an embroidery pattern are created (Step S 33 ). The embroidery data for the character design 56 are stored in the EEPROM 64 (Step S 35 ). The processing advances to Step S 37 .
[0048] The embroidery pattern that is sewn based on the embroidery data that have been created using the known conversion technology will be explained. With the known conversion technology, a character is ordinarily divided into block units. The setting information (the sewing order, the sewing starting point, and the sewing ending point) that is included in the embroidery data is set such that the sewing will be performed with adjacent blocks being taken into account. The blocks are sections into which the character is divided by curving portions. That means that even where it is possible to sew the character as if it were written as a single continuous line, in many cases the character is actually sewn in part. Therefore, cases may occur in which the quality of the embroidered pattern is affected by differences in the sewing direction and boundary lines that are formed within the character. Furthermore, with the known conversion technology, the sewing starting point and the sewing ending point are set such that the sewing is started at the upper left of the character, and the sewing ends at any chosen point in the character. Therefore, a case may occur in which a jump stitch passes over the embroidered character.
[0049] FIG. 11 shows an embroidery pattern 44 of the alphabetic character “B” as an example of an embroidery pattern that is sewn based on the embroidery data that have been created using the known conversion technology. The embroidery pattern 44 is sewn by causing the sewing needle 7 to pierce the work cloth 100 at the needle drop points in the order that is indicated by arrows 45 , 46 , which is based on the sewing order that is contained in the embroidery data. Values are set that indicate positions of a starting point 451 of the arrow 45 and a starting point 461 of the arrow 46 as the sewing starting points. In the same manner, values are set that indicate positions of an ending point 452 of the arrow 45 and an ending point 462 of the arrow 46 as the sewing ending points. Unlike the embroidery pattern 41 of the alphabetic character “B” (refer to FIG. 4 ), which is sewn based on the standard character embroidery data, the embroidery pattern 44 is divided at the position where the ending point 452 of the arrow 45 and the ending point 462 of the arrow 46 meet. A boundary line is therefore formed at that position. Furthermore, because the ending point 462 of the arrow 46 is positioned higher than the bottom edge of the character, in a case where embroidery patterns are sewn in which a plurality of characters are combined with the alphabetic character “B” to form a character string, a jump stitch between the embroidered patterns for the individual characters may pass over the embroidered pattern.
[0050] On the other hand, as shown in FIG. 6 , in a case where the standard character embroidery data for the same character as that of the character that was specified are stored in the ROM 62 at Step S 25 (YES at Step S 29 ), the embroidery data for sewing the character design 56 as an embroidery pattern are created based on the setting information that is included in the standard character embroidery data (Step S 31 ). Specifically, the setting information that is included in the embroidery data that are created is almost equal to the setting information that is included in the standard character embroidery data. Therefore, in a case where the sewing is performed based on the created embroidery data, the sewing order, the sewing starting point, and the sewing ending point respectively match the sewing order, the sewing starting point, and the sewing ending point that are included in the standard character embroidery data. As was explained with reference to FIG. 4 , the setting information (the sewing order, the sewing starting point, and the sewing ending point) that is included in the standard character embroidery data have been adjusted such that the high quality embroidered pattern can be sewn in the work cloth 100 based on the standard character embroidery data. Therefore, in a case where the embroidery data is created based on the setting information that is included in the standard character embroidery data, the embroidery data make it possible for the character design 56 to be sewn as an embroidered pattern with high quality. The embroidery data that are created for the individual character are stored in the EEPROM 64 (Step S 35 ). The processing advances to Step S 37 .
[0051] At Step S 37 , a determination is made as to whether the processing at Steps S 21 to S 35 has been performed for all image data of character designs 53 that were stored in the RAM 63 at Step S 17 (refer to FIG. 5 ) (Step S 37 ). In a case where image data of a character design 53 remains in the RAM 63 for which the processing has not been performed (NO at Step S 37 ), the processing returns to Step S 21 . In a case where the processing has been performed for all image data of character designs 53 were stored in the RAM 63 (YES at Step S 37 ), the embroidery data for sewing as embroidery patterns all of the characters 51 that are contained in the image 50 have been created character by character. The character acquisition processing is terminated.
[0052] The sewing processing will be explained with reference to FIG. 12 . An explanation will be given below, using a case in which the user first creates a character string in which the character designs 56 (refer to FIG. 10 ) that were acquired by the sewing machine 1 in the character acquisition processing (refer to FIGS. 5 and 6 ), are arranged in a desired order, and then sew the character string in the work cloth 100 as an embroidery pattern. The sewing processing is started by the launching of a sewing processing program that is stored in the ROM 62 , the program being launched in a case where a command to perform sewing of an embroidery pattern is input by the user through the touch panel 26 (refer to FIG. 1 ). The sewing processing is performed by the executing of the program by the CPU 61 .
[0053] First, in a case where the user's desired character string is input through the touch panel 26 , the input character string is accepted (Step S 41 ). The characters that are included in the accepted character string are specified. The embroidery data for sewing the specified characters as embroidery patterns are selected from among the embroidery data that were stored in the EEPROM 64 at Step S 35 in the character acquisition processing (refer to FIG. 6 ) (Step S 43 ). For example, the user inputs a character string in which the ten characters 51 (the character 51 A, the character 51 B, the character 51 C, the character 51 D, the character 51 E, the character 51 F, the character 51 G, the character 51 H, the character 51 I, and the character 51 J) that are contained in the image 50 (refer to FIG. 7 ) are arranged in the same order as in the image 50 . In this case, the embroidery data for sewing, as embroidery patterns, each of the characters 51 A to 51 J that are included in the input character string, respectively, are selected from the EEPROM 64 .
[0054] Next, in a case where the user performs, through the touch panel 26 , an operation that edits the character string, the content of the editing is accepted (Step S 45 ). The content of the editing may include alignment of the characters, adjustment of the embroidery position, rotation, and the like, for example. In accordance with the accepted editing content, edit processing is performed on the embroidery data that were selected at Step S 43 (Step S 45 ). The sewing of the embroidery patterns is performed by controlling the various types of motors based on the edited embroidery data (Step S 47 ). The result, as shown in FIG. 13 , is that an embroidery pattern 58 is sewn in the work cloth 100 , the embroidery pattern 58 including the character designs 56 (refer to FIG. 10 ) that were acquired by the character acquisition processing (refer to FIG. 5 ) and that include the characters 51 A to 51 J. The sewing processing is then terminated.
[0055] Now, another case will be given in which in addition to the image data of the image 50 (refer to FIG. 7 ), image data of an image that is different from the image 50 has been acquired from the memory card 171 (refer to FIG. 3 ) in the character acquisition processing (refer to FIGS. 5 and 6 ). In this case, based on the acquired image data, embroidery data has been created for sewing, as embroidery patterns, character designs 57 that are shown in FIG. 14 , and that the created embroidery data has been stored in the EEPROM 64 . Thus, the embroidery data for sewing, as embroidery patterns, the character designs 56 , which include the characters 51 A to 51 J (refer to FIG. 10 ), and the character designs 57 , which include a character 51 K, a character 51 L, a character 51 M, a character 51 N, a character 51 O, and a character 51 P (refer to FIG. 14 ), have been stored in the EEPROM 64 character by character.
[0056] For example, the character 51 K, the character 51 B, the character 51 L, the character 51 M, the character 51 N, the character 51 O, the character 51 F, the character 51 G, the character 51 H, the character 51 I, and the character 51 P (refer to FIGS. 10 and 14 ) are accepted at Step S 41 as the character string that the user desires. Of the characters 51 A to 51 J in the character designs 56 (refer to FIG. 10 ) that were created based on the image data of the image 50 , in this character string, the character 51 A is replaced by the character 51 K, while the character 51 C, the character 51 D, and the character 51 E are replaced by the character 51 L, the character 51 M, the character 51 N, and the character 51 O, and the character 51 J is replaced by the character 51 P. In this sort of case, the embroidery data that correspond to the individual characters that are included in the accepted character string are selected, character by character, from the embroidery data that are stored in the EEPROM 64 (Step S 43 ), and after the edit processing (Step S 45 ), the sewing of the embroidery pattern is performed (Step S 47 ).
[0057] The result, as shown in FIG. 15 , is that an embroidery pattern 59 is sewn in the work cloth 100 , the embroidery pattern 59 including the character designs 56 , 57 that were acquired by the character acquisition processing and that include the character 51 K, the character 51 B, the character 51 L, the character 51 M, the character 51 N, the character 51 O, the character 51 F, the character 51 G, the character 51 H, the character 51 I, and the character 51 P.
[0058] As explained above, the sewing machine 1 is able to extract, character by character, the characters 51 that are contained in the acquired image 50 without changing the style of the characters 51 (Step S 17 ), and is able to sew the embroidery patterns for the character designs 56 of the extracted characters 51 (Step S 47 ). Therefore, the user is able to sew an embroidery pattern of a character that is not registered in the sewing machine 1 in advance, such as a character that is handwritten by the user or a character that is prepared in a special font, for example. Because the embroidery data are created character by character (Step S 17 ), the sewing machine 1 is also able to easily sew an embroidery pattern in which a plurality of character designs 56 are combined as the user desires (Steps S 41 to S 47 ). Even in a case where the sizes of the characters that are contained in the image 50 are not uniform, the sewing machine 1 creates the character designs 56 such that the character sizes are the same (Step S 23 ) and creates the embroidery data (Step S 31 ) that make it possible to sew the embroidery pattern. Therefore, in a case where the embroidery pattern that is sewn is of a character string in which a plurality of characters are positioned side by side, the characters can be sewn in a uniform size, so an attractive embroidery pattern that shows unity as a whole can be sewn. Note that the embroidery data are created after the character designs 56 have been adjusted by making the sizes of the character designs 55 uniform. Therefore, the sizes of the embroidery patterns to be sewn can be reliably made uniform.
[0059] The sewing machine 1 is also able to create the embroidery data based on the standard character embroidery data (Step S 31 ), so it is able to sew the embroidery pattern with a good finish. Specifically, the sewing machine 1 is able to make the setting information (the sewing order, the sewing starting point, and the sewing ending point) for the embroidery pattern of the character designs 56 resemble the setting information of the standard character embroidery data. This makes it possible for the sewing machine 1 to sew the embroidery pattern with an even better finish.
[0060] The sewing machine 1 can also create embroidery data of a character string by selecting from the EEPROM 64 (Step S 43 ) the embroidery data for the embroidery patterns of the character designs 56 that were created character by character in accordance with a character string that was input. Therefore, by using the sewing machine 1 , the user can freely create a character string that includes characters in a desired style and can perform the embroidering of the embroidery patterns for that character string.
[0061] Note that the present disclosure is not limited to the embodiment that is described above, and various types of modifications can be made. The sewing machine 1 may also always use a known conversion method to create the embroidery data for sewing the character designs 56 as embroidery patterns, without referring to the standard character embroidery data that are stored in the ROM 62 . The setting information that is included in the standard character embroidery data is not limited to being the sewing order, the sewing starting point, and the sewing ending point. Instead of creating the embroidery data after the sizes of the character designs 56 have been modified, the sewing machine 1 may first create the embroidery data based on the unmodified character designs 56 , then change the embroidery data such that the sizes of the embroidery patterns to be sewn according to the embroidery data are changed. The sewing machine 1 may also acquire the standard character embroidery data from a server or the like to which the sewing machine 1 is connected through a network.
[0062] The present disclosure may also be implemented in an embroidery data creation device that creates the embroidery data. The embroidery data creation device may be configured as a general-purpose computer, for example. In the embroidery data creation device, the embroidery data may be created by the performing of the character acquisition processing (refer to FIGS. 5 and 6 ). The created embroidery data may be acquired by the sewing machine 1 through the memory card 171 or the like. The sewing machine 1 may perform the sewing of the embroidery pattern based on the acquired embroidery data.
[0063] In the embodiment that is described above, the image data of the image 50 that is stored in the memory card 171 is acquired, and the character designs 56 are extracted. The image data of the image 50 may also be acquired by another method. For example, in a case where the sewing machine 1 is connected to a camera or a scanner, the sewing machine 1 may acquire the image data from the camera or the scanner. In a case where the embroidery data are created in the sewing machine 1 based on a plurality of character designs in which the characters are the same, the sewing machine 1 may also be made such that the user can select the embroidery data that are based on the desired character designs.
[0064] The setting information in the standard character embroidery data may also be made such that the user can adjust it. For example, the sewing machine 1 may be made such that the user can set the setting information in the embroidery data manually in a case where the standard character embroidery data for characters that are the same as the characters in the created character designs have not been stored in the ROM 62 . The sewing machine 1 may also create the embroidery data for sewing the character designs as the embroidery patterns based on the setting information that has been set.
[0065] In a case where the standard character embroidery data for characters that are the same as the characters in the created character designs have not been stored in the ROM 62 , the sewing machine 1 may also create the embroidery data for sewing the character designs as the embroidery patterns based on the setting information that is included in the standard character embroidery data for other characters whose shapes resemble those of the characters in the character designs.
[0066] The apparatus and methods described above with reference to the various embodiments are merely examples. It goes without saying that they are not confined to the depicted embodiments. While various features have been described in conjunction with the examples outlined above, various alternatives, modifications, variations, and/or improvements of those features and/or examples may be possible. Accordingly, the examples, as set forth above, are intended to be illustrative. Various changes may be made without departing from the broad spirit and scope of the underlying principles.
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An apparatus includes a processor and a memory. The memory is configured to store computer-readable instructions therein, wherein the computer-readable instructions instruct the sewing machine to execute steps comprising acquiring image data including one or more characters, extracting, from acquired image data, one or more character designs with respect to each character included in the acquired image data, wherein the character design represents each character included in the acquired image data, generating embroidery data with respect to each character based on the extracted character design, wherein the embroidery data represents an embroidery pattern in a predetermined size.
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TECHNICAL FIELD
[0001] The present invention relates to cleaning exhaust gas of an automobile engine, in particular, to air-fuel ratio control on an automobile equipped with a lean NOx catalyst.
BACKGROUND OF THE INVENTION
[0002] In engines burning fuel at lean side of an air-fuel ratio (hereinafter referred to as a lean-burn engine), a lean NOx catalyst (LNC) is employed to occlude NOx exhausted at lean air-fuel ratio and to reduce the occluded NOx at rich or theoretical air-fuel ratio. Since the amount of NOx that the lean NOx catalyst can occlude is limited, the engine cannot continue the lean-burn operation for a long time. To continue the lean-burn operation for a long time, the air-fuel ratio need to be changed temporarily to rich side to reduce the NOx occluded in the lean NOx catalyst during the lean-burn operation, causing the catalyst to release the occluded NOx. This process is referred to as “shift-to-rich process”.
[0003] It is well known in the art to perform the shift-to-rich process periodically during the lean-burn operation to actively reduce the NOx occluded in the LNC, and to perform the shift-to-rich process on transition from the lean-burn operation to stoichiometric air-fuel ratio operation (hereinafter referred to as “stoichiometric operation”) to reduce the NOx occluded in the LNC. It is also known to estimate the amount of the NOx occluded in the LNC in order to vary the air-fuel rich amount according to the estimated amount, one example of which is disclosed in The Japanese Laid-Open Patent Application No. 7-139340.
[0004] According to this application, it is disclosed to provide a NOx estimating counter for estimating the amount of NOx occluded in the LNC. This counter is incremented during the lean-burn operation and is decremented while performing the shift-to-rich process or during the stoichiometric operation. More specifically, a value depending on operation state of the engine is added to the NOx estimating counter at every certain period during the lean-burn operation. A value depending on the fuel amount exceedingly fed to the engine is subtracted from the counter at every certain period while performing the shift-to-rich process or during the stoichiometric operation.
[0005] The Japanese Laid-Open Patent Application No. 11-6421 describes other technique which comprises means for determining a saturation state of NOx amount occluded in the NOx catalyst to adequately change the rich amount of the air-fuel ratio, causing the shift-to-rich process to be initiated with appropriate timing. More specifically, this technique includes a calculator for calculating the amount of NOx generated in the engine in accordance with a detected value of internal pressure in cylinder of the engine. When the calculated amount is determined as saturation state of NOx occluded in the NOx catalyst, the shift-to-rich process is initiated. Predetermined period according to engine speed is set in a timer and shift-to-rich process is performed during this set period.
[0006] In the above-mentioned conventional technique, however, the period for the shift-to-rich process is set according to the engine speed and therefore the shift-to-rich process is not adapted appropriately to the change of engine load. More specifically, in the shift-to-rich process when the lean NOx catalyst is saturated, sufficient CO and HC have to be supplied to the lean NOx catalyst enough to reduce the occluded NOx. However, setting the period according to only the engine speed, it is probable that the amount of reducing agent (HC, CO) becomes short and can not reduce all of the NOx or the amount of reducing agent becomes too much and may degrade exhaust performance. Moreover, in the case that a three-way catalyst is provided upstream of the lean NOx catalyst, the reducing agent may become short because the reducing agent is oxidized by the three-way catalyst during the shift-to-rich process, as in the case of the air-fuel ratio changing from lean side to stoichiometry.
[0007] Considering the above-mentioned problems, it is objective of the invention to provide an electronic control unit for cutting the emission as well as improving the drivability by appropriately controlling the shift-to-rich process for reducing the NOx occluded in the lean NOx catalyst during the shift-to-rich process and transition from the lean operation to the stoichiometric operation.
SUMMARY OF THE INVENTION
[0008] To solve the above-mentioned problems, according to one aspect of the invention, an electronic control unit is provided which controls an air-fuel ratio of an engine having a lean NOx catalyst in its exhaust system, comprising: an estimator for estimating NOx amount occluded in the lean NOx catalyst; means for performing shift-to-rich process responsive to the NOx amount estimated by said estimator exceeding a predetermined value; a calculator for calculating an accumulated value of an exhaust flow amount; and means for completing said shift-to -rich process responsive to said accumulated value of the exhaust flow amount exceeding a threshold value.
[0009] Completing the shift -to-rich process based on the accumulated value of the exhaust flow amount, which is correlated with the amount of the reducing agent (HC, CO), enables the NOx occluded in the lean NOx catalyst to be precisely reduced, and resultingly the exhaust gas can be cleaned at higher level.
[0010] According to second aspect of the invention, an electronic control unit is provided for controlling an air -fuel ratio of an engine having a lean NOx catalyst in its exhaust system, comprising: an estimator for estimating NOx amount occluded in the lean NOx catalyst; means for performing shift -to -rich process on a transition from lean -burn operation to stoichiometric operation; a calculator for calculating an accumulated value of an exhaust flow amount; and means for completing said shift -to-rich process responsive to said accumulated value of the exhaust flow amount reaching a threshold value which is set based on the occluded NOx amount estimated by said estimator.
[0011] On the transition from the lean-burn operation to the stoichiometric operation, the shift-to-rich process is performed to reduce the lean NOx catalyst and the timing for completing the shift-to-rich process is determined based on the accumulated value of the exhaust flow amount and the estimated amount of the occluded NOx, enabling the NOx occluded in the lean NOx catalyst to be precisely reduced and resultingly the exhaust gas is cleaned at higher level.
[0012] According to third aspect of the invention, said electronic control unit further comprises a three-way catalyst and an air -fuel ratio sensor upstream of said lean NOx catalyst, wherein said calculating means starts to accumulate the exhaust flow amount when said air-fuel ratio sensor indicates rich.
[0013] Since the accumulation of the exhaust flow amount is started when the air fuel ratio sensor upstream of the lean NOx catalyst indicates rich, the effect of degradation of the three-way catalyst placed upstream of the sensor may be avoided and the NOx occluded in the lean NOx catalyst may be reduced appropriately.
[0014] According to fourth aspect of the invention, said electronic control unit further comprises adding means for adding NOx amount to be occluded in said lean NOx catalyst during said shift-to-rich process, to said estimated occluded NOx amount.
[0015] It is possible to reduce the NOx occluded in the lean NOx catalyst on the transition from the lean-burn operation to the stoichiometric operation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] [0016]FIG. 1 is a block diagram illustrating the structure of an engine, an exhaust gas cleaning unit and an electronic control unit in accordance with one embodiment of the present invention;
[0017] [0017]FIG. 2 is a flow chart of the process for calculating a feedback target of an air-fuel ratio;
[0018] [0018]FIG. 3 is a flow chart of the process for calculating an intake air amount correlation value;
[0019] [0019]FIG. 4 is a flow chart of the process for calculating an accumulated value of an intake air amount during rich process on a transition from a lean operation to a stoichiometric operation;
[0020] [0020]FIG. 5 is a flow chart of the process for calculating an intake air amount correlation value during the shift-to-rich process;
[0021] [0021]FIG. 6 is a flow chart of the process for calculating a target air-fuel ratio;
[0022] [0022]FIG. 7 is a flow chart of the process for calculating a target air-fuel ratio during the shift-to-rich process;
[0023] [0023]FIG. 8 is a drawing of a table for retrieving a completion threshold value for shift-to-rich process with CRSPL in step S 617 ; and
[0024] [0024]FIG. 9 is a drawing of a table for retrieving a completion threshold value for shift-to-rich process with CRSP in step S 607 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] Now one preferred embodiment of the invention will be described referring to the attached drawings. FIG. 1 illustrates the structure of an engine to which the invention is applied. As shown in FIG. 1, an engine 1 comprises an air intake pipe 2 , a fuel injector 6 , sensors 11 and an exhaust system. With the intake pipe 2 is provide a pressure sensor 7 for detecting pressure within the air intake pipe (PB), which is converted to electrical signal by the pressure sensor 7 to be supplied to an electronic control unit (hereinafter referred to as ECU) 20 .
[0026] The sensors 11 include an engine revolution (NE) sensor, which generates a signal pulse (TDC pulse) at a predetermined crank angle position of the crankshafts of the engine 1 and sends to ECU 20 the signal according to the engine revolution. The sensors 11 generally represent a plural of sensors including some other sensors such as the engine water temperature sensor.
[0027] A three-way catalyst (hereinafter referred to as TWC) 13 for cleaning HC, CO and NOx is provided in the exhaust system. Downstream of the TWC 13 , a lean NOx catalyst (LNC) 15 for occluding the NOx is provided in series. The LNC 15 occludes the NOx generated during lean operation and then the occluded NOx will be reduced by HC and CO, contained in exhaust gas, to release N2 during rich operation. Upstream of the TWC 13 , a linear A/F (LAF) sensor 14 is provided, which outputs an electric signal almost proportional to an air/fuel ratio. Between the TWC 13 and the LNC 15 , there is provided an O2 sensor 16 , which outputs an electric signal changing its voltage level extremely between rich side and lean side across the theoretical air -fuel ratio. Signals from these sensors are supplied to the ECU 20 .
[0028] The electronic control unit ECU 20 is implemented in a computer, which comprises read-only memory (ROM) for storing programs to be executed on CPU and data to be used with the programs, random access memory (RAM) for storing retrieved programs and data and providing work areas for computing, a central processing unit (CPU) for executing the programs, a processing circuit for processing input signals from various sensors and a driving circuit for sending control signals to each engine element. Based on such hardware configuration, FIG. 1 illustrates the ECU 20 with functional blocks.
[0029] General Functionality of the Electronic Control Unit
[0030] An occluded NOx estimate block 23 receives the intake pipe pressure PB from the sensor 7 and the engine revolution NE from the sensors 11 and then estimates the amount of the NOx occluded in the lean NOx catalyst 15 based on the received PB and NE.
[0031] During the lean-burn operation, an adding block 25 assumes a possible NOx amount that should be occluded during the shift-to-rich process. The adding block 25 then adds such assumed amount to the occluded NOx amount that has been previously estimated by the occluded NOx estimate block 23 to obtain a sum value. The obtained sum value is compared with a predetermined saturation value by a determination block 26 . If the determination block 26 determines that the sum value of the occluded NOx amount exceeds the predetermined value, it will set a shift-to-rich permission flag F-RSPOK to 1. In response to this set, a target air/fuel ratio setting block 21 set an air/fuel ratio to a shift-to-rich process target air/fuel ratio KBSRSP. In one embodiment, the shift-to-rich process target air/fuel ratio is 13.0 for example. The reason the adding block 25 adds the NOx amount that should be occluded during the shift-to-rich process is as follows: Even during the shift-to-rich process, some amount of NOx may be occluded in the lean NOx catalyst 15 . So, by determining the transition to the shift-to-rich based on the sum of such probable amount to the estimated amount of the occluded NOx, it is possible to prevent the NOx generated during the shift-to-rich process from being released into the air without being occluded in the lean NOx catalyst 15 .
[0032] An operation state determination block 24 determines the operation state of the concerned automobile based on such parameters as the engine revolution, the air intake pipe pressure, and an accelerator opening degree. The operation state determination block 24 then determines a transition between a lean-burn operation mode and a stoichiometric operation mode and sends an corresponding signal to a target air/fuel ratio setting block 21 .
[0033] When the target air/fuel ratio setting block 21 receives, from the operation determination block 24 , the signal indicating the transition from the lean-burn operation to the stoichiometric operation (hereinafter referred to as “transition from lean to stoichiometry), it performs a process for setting the air/fuel ratio from a theoretical value to a rich value so that the NOx occluded in the lean NOx catalyst 15 during the lean-burn operation could be reduced and accordingly the lean NOx catalyst 15 could recover its functionality. This process is called a “rich process on the transition to stoichiometry”. In one embodiment, the target air/fuel ratio setting block 21 may set a target air/fuel ratio KBS 1 on the transition from lean to stoichiometry to 13.0 for example. In this case, the adding block 25 adds the amount of NOx that is assumed to be occluded during the rich process on the transition to stoichiometry to the occluded NOx amount that has been estimated by the occluded NOx estimate block 23 . This resulting value will be used as a threshold by a threshold value setting block 29 to determine a completion of the rich process.
[0034] An intake air amount correlation value accumulation block 27 starts to accumulate an intake air amount correlation value NTI when it receives a reverse signal from the O2 sensor 16 (indicating that the air/fuel ratio of the exhaust gas flowing into the lean NOx catalyst 15 changes from the lean side to the rich side). Since the amount of the intake air has a correlation with the amount of reducing gases (HC and CO), the accumulated amount of the intake air accumulated since the air/fuel ratio of the exhaust gas changes from the lean side to the rich side has a correlation with the progress of reducing the NOx occluded by the lean NOx catalyst 15 . When the accumulated intake air amount correlation value accumulated by the accumulation block 27 reaches the threshold value set by the threshold value setting block 29 , a reduction completion decision block 31 decides to complete the reduction process and send a corresponding signal to the target air/fuel ratio setting block 21 .
[0035] The threshold value setting block 29 sets a fixed value as a threshold value during the shift-to-rich process in the lean-burn operation. During the rich process on the transition from lean to stoichiometry, the threshold value setting block 29 obtains a corresponding threshold value by searching a table based on the sum value that is obtained by adding the amount of NOx that is assumed to be occluded during the rich process on the transition to stoichiometry to the occluded NOx amount that has been estimated by the occluded NOx estimate block 23 .
[0036] A fuel injection control block 22 calculates a fuel injection pulse width Tout by a following equation using the established target air/fuel ratio, and drives the fuel injection unit 6 :
T out= TIM*Kcyl+TiVb (1)
[0037] where TIM represents a basic fuel injection width, Kcyl represents a fuel correction term and TiVb represents an invalid fuel injection width. Appropriate values are pre-selected for TIM and TiVb. The fuel correction term is calculated by a following equation:
Kcyl=KCMD*KAF (2)
[0038] where KCMD represents a feed-forward (F/F) correction term, which is to be determined with the basic target air/fuel ratio KBS and the shift-to-rich process target air/fuel ratio KBSRSP depending on the operational conditions. KAF is a feedback (F/B) correction term. ECU 20 executes the air/fuel ratio feedback with KCMD as its target.
[0039] [0039]FIG. 2 is a flow chart illustrating a process for calculating the F/F correction term KCMD, which is executed with each TDC pulse. First the intake air amount correlation value is calculated by means of another process that will be described later with reference to FIG. 3 (S 201 ), and then the basic target air/fuel ratio KBS is calculated by means of a basic target air/fuel ratio calculation process depending on the operational conditions, which will be also described later in conjunction with FIG. 6 (S 203 ). The shift-to-rich process target air/fuel ratio KBSRSP is calculated by means of a shift-to-rich process coefficient calculation process that will be explained later with reference to FIG. 7 (S 205 ). KBS is set to KCMD (S 207 ) and the F/B correction term KAF is calculated by means of the feedback control computing (S 209 ). Thus, the injection correction term Kcyl based on the air/fuel ratio is calculated, which is required for calculating the fuel injection pulse width Tout.
[0040] Accumulation of Exhaust Gas Flow Amount
[0041] [0041]FIG. 3 is a flow chart illustrating a process for calculating the intake air amount correlation value NTI, which is performed in step S 201 of FIG. 2. At step S 301 of FIG. 3, NETI is calculated by multiplying {fraction (1/16)} of the basic fuel injection width TIM by the engine revolution NE. Then NTI is calculated by multiplying NETI by an air pressure correction term KPA that is to be determined based on an air pressure detected by an air pressure sensor (S 303 ). Instead of calculating the intake air amount, the actually measured amount may be alternatively used as the intake air amount.
[0042] In embodiments of the invention, an accumulated value of an intake air amount correlation value is used as an accumulated value of the exhaust flow amount. The intake air amount correlation value accumulation block 27 of FIG. 1 performs this accumulation. FIG. 4 shows a flow chart for accumulating the intake air amount correlation value NTI when the rich process of the air-fuel ratio is performed on the transition form the lean-burn operation to the stoichiometric operation. FIG. 5 shows a flow chart for accumulating the intake air amount correlation value NTI when the shift-to-rich process is performed during the lean- burn operation.
[0043] Now referring to FIG. 4, it is determined based on a lean-burn permission flag F- 3 LB whether the lean burn operation is permitted or not (S 401 ). If the lean-burn operation is permitted, the accumulated value SLSNTI is set to zero (S 405 ) because there is no need to obtain the accumulated value. If the lean-burn operation is not permitted, it is determined whether a fuel cut operation is executed or not (S 403 ). If the fuel cut operation is executed, this process is terminated. Otherwise, it is determined whether the output of the O2 sensor 16 (SVO2) is equal to or more than a predetermined threshold value, in other words, whether the air-fuel ratio has been reversed from the lean side to the rich side (S 407 ). If the air-fuel ratio has not been reversed, this process is terminated. If the air-fuel ratio has been reversed to rich side, the NTI calculated by the process of FIG. 3 is added to the previous accumulated value to calculate current accumulated value SLSNTI (S 409 ). This accumulated value is used for determining the completion of the rich process at step S 627 of FIG. 6. Processes of FIG. 4 and FIG. 5 are executed in constant cycle, for example, every 100 milliseconds.
[0044] [0044]FIG. 5 is a flow chart illustrating a process for calculating an accumulated value SRSNTI of the NTI when the shift-to-rich process is performed during the lean-burn operation. First, the process determines whether the shift-to-rich process permission flag F-RSPOK is set to 1 or not (S 501 ). If not, the process sets the accumulated value SRSNTI to zero (S 505 ). If the flag is set to 1, the process determines whether the output SVO2 of the O2 sensor 16 exceeds a predetermined threshold value or not, in other words, whether the air/fuel ratio has been reversed from the lean side to the rich side (S 503 ). If the air/fuel ratio has not been reversed, the process is terminated. If the air/fuel ratio has been reversed, NTI calculated through the process of FIG. 3 is added to the previous accumulated value to produce the current accumulated value SRSNTI (S 507 ). This current accumulated value will be used to determine the completion of the shift-to-rich process in step S 719 of FIG. 7.
[0045] Calculation of Basic Target Air-fuel Ratio KBS
[0046] [0046]FIG. 6 illustrates a flow chart for calculating the basic target air-fuel ratio KBS at step S 203 of FIG. 2. A flag F-KBS 1 indicates that the rich process on transition from the lean-burn operation to the stoichiometric operation is in progress, and indicates the target air-fuel ratio is a rich air-fuel ratio KBS 1 (for example, 13.0). If this flag is not 1, it is determined whether the fuel cut operation is in progress (S 603 ). If the fuel cut operation is not in progress, it is determined whether an idling operation is in progress (S 609 ).
[0047] Then it is determined whether the lean-burn operation can be performed (S 611 ). If the lean-burn operation is permitted, the flag F-LB is set to 1. It is determined whether the flag F-LB, which indicates to permit the lean-burn operation, is 1 or not (S 613 ). If the answer is YES, the target air-fuel ratio (KBSMAP) during the lean-burn operation is calculated in S 615 and subsequent steps.
[0048] The amount of NOx occluded on the transition from lean to stoichiometry CRSPLS is added to occluded NOx estimate value CRSP to obtain a occluded NOx estimation value CRSPL (S 615 ). A table shown in FIG. 8 is retrieved with this CRSPL and the retrieved value is set to a threshold value to the accumulated value of exhaust flow amount (the intake air amount correlation value) to determine the completion of the rich process on the transition from lean to stoichiometry (S 617 ). This threshold value is used at step S 627 later.
[0049] A predetermined map is searched with the engine speed NE and the air intake pipe pressure PB as parameters to obtain a target air-fuel ratio KBSMAP during the lean-burn process (S 619 ). This KBSMAP is set to the basic target air-fuel ratio KBS (S 621 ).
[0050] If the flag F-KBS 1 is set to 1 at step S 601 , or the lean-burn permission flag is not 1 (indicating the lean-burn operation is prohibited) at step S 613 , the process moves to step S 627 to determine the completion of the rich process. If it is determined that the fuel cut operation is in progress at step S 603 , the lean-burn permission flag F-LB is set to zero (S 605 ). A table shown in FIG. 9 is then searched in the same manner as step S 627 to obtain rich process completion threshold value (S 607 ). The process moves to step S 627 to determine the completion of the rich process. When returning from the fuel cut operation, there are almost no NOx occluded in lean NOx catalyst and so the table search is done based on the estimated value CRSP.
[0051] If the accumulated value SLSNTI has not exceeded the completion threshold value at step S 627 , target air-fuel ratio KBS 1 for rich process on the transition from lean to stoichiometry is set to the target air-fuel ratio KBS (S 633 ), and the flag F-KBS 1 is set to 1 (S 635 ). If the accumulated value SLSNTI has exceeded the completion threshold value at step S 627 , a theoretical air-fuel ratio KBS 0 is set to the target air-fuel ratio (S 629 ) and the flag F-KBS 1 is set to zero (S 631 ). According to the above-mentioned process, on the transition from lean to stoichiometry or when returning from the fuel cut operation, occluded NOx can be reduced by setting the air-fuel ratio to KBS 1 temporarily.
[0052] In addition, it is important to set to KBS 1 (target air-fuel ratio for rich process on the transition from lean to stoichiometry) the value that can supply the lean NOx catalyst with sufficient HC and CO, which can reduce the NOx in the lean NOx catalyst considering cleaning by three-way catalyst (around 13.0, for example). Setting the appropriate value to KBS 1 enables to prevent the drivability from degradation caused by excessive rich air-fuel ratio and to prevent the emission from deterioration caused by setting insufficient rich amount at the same time.
[0053] If it is determined that the engine runs at idle, the flag F-LB is set to zero (S 623 ) and the basic target air-fuel ratio KBS is set to an target air-fuel ratio for idling KBSIDL (stoichiometric air-fuel ratio) (S 625 ).
[0054] Calculation of Target Air-Fuel Ratio KBSRSP for Shift-to-rich process During Lean-burn Operation
[0055] With reference to FIG. 7, the shift-to-rich process for the air/fuel ratio during the lean-burn operation (step S 205 of FIG. 2) will be described. This shift-to-rich process is performed for the purpose of temporarily changing the air/fuel ratio to the rich side during the lean-burn operation to reduce the NOx occluded by the lean NOx catalyst and to recover the cleaning functionality of the catalyst.
[0056] It is determined whether the lean-burn operation is permitted or not by checking the lean-burn permission flag F-LB (S 701 ). If the flag is set to 1, which means that the lean-burn operation is permitted, an occluded NOx estimate value (CTSV) map is searched using, as searching parameters, the engine revolution NE and the intake pipe pressure PB which are detected by each sensor in order to obtain an occluded NOx estimate value CTSV (S 703 ). The occluded NOx estimate value obtained in step S 703 is added to the previously estimated value of the occluded NOx to produce the current value CRSP (S 705 ). Then, the process adds the NOx amount CRSPRS, which is assumed to be occluded by the lean NOx catalyst during the lean-burn operation, is added to the current CRSP to obtain the estimated value CRSPR for the occluded NOx (S 707 ).
[0057] It is determined whether the estimated value CRSPR for the occluded NOx exceeds a predetermined saturation determination value or not (S 709 ). If the estimated value CRSPR does not exceed the predetermined saturation determination value, the process is terminated because no shift-to-rich process is required, and will restart the accumulation process for the estimated value of the occluded NOx in step S 701 in the subsequent processing cycle. If the estimated value CRSPR exceeds the predetermined saturation determination value, the shift-to-rich process is performed in step S 711 and subsequent steps.
[0058] It is determined whether the shift-to-rich process permission flag F-RSPOK is set to 1 or not (S 711 ). If the flag is set to 0, the flag F-RSPOK is set to 1 (S 713 ) and the air/fuel ratio KBSRSP for the shift-to-rich process is set to the shift-to-rich process target air/fuel ratio (13.0 for example) (S 715 ). Then the KBSRSP is set to the basic target air/fuel ratio KBS depending on the operational conditions (S 717 ).
[0059] If the lean-burn permission flag is set to 1 in step S 711 , the process proceeds to step S 719 to determine whether the accumulated value SRSNTI of the intake air amount correlation value NTI exceeds a completion threshold value. If it does not exceed the completion threshold value, the process proceeds to step S 715 , where the shift-to-rich process continues. If the accumulated value for NTI exceeds the completion threshold value in step S 719 , the current estimated value CRSP of the occluded NOx is set to the initial value (corresponding to the NOx amount that should be occluded on the transition from rich process to lean operation) (S 721 ), the shift-to-rich process permission flag F-RSPOK is set to 0 (S 723 ), the KBSRSP is set to the theoretical air/fuel ratio (S 725 ) and the process is terminated.
[0060] Although the linear air/fuel ratio sensor is used as the air/fuel ratio sensor upstream of the three-way catalyst in the above-mentioned embodiment, an O2 sensor may be used alternatively. It should be noted that although the invention has been described in conjunction with the specific embodiment, the invention is not intended to be limited to such specific embodiment.
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The invention provides an electronic control unit for controlling an air/fuel ratio of an engine having a lean NOx catalyst in its exhaust system in order to improve the cleaning of exhaust gas during rich process to reduce lean NOx catalyst. The electronic control unit comprises: an estimator for estimating NOx amount occluded in the lean NOx catalyst; means for performing shift-to-rich process responsive to the NOx amount estimated by said estimator exceeding a predetermined value; a calculator for calculating an accumulated value of an exhaust flow amount; and means for completing the shift-to-rich process responsive to the accumulated value of the exhaust flow amount exceeding a threshold value. Completing the shift-to-rich process using the accumulated value of the exhaust flow amount, which is correlated with the amount of the reducing agent (HC, CO), enables the NOx occluded in the lean NOx catalyst to be precisely reduced, and the exhaust gas is cleaned at higher level.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a hinge for hanging the free panel of a bipartite corner cabinet door on the panel that is hung to turn on the carcase supporting wall, consisting of two mounting parts each associated with the door panels, which can be turned by about 90 degrees, from the position wherein the door panels are held approximately at right angles to one another when the corner cabinet is closed, to a position substantially in parallel alignment when the corner cabinet door is open, one of the mounting parts having a hinge cup which can be fixed in one door panel and in which a multi-angled hinge arm which can be adjustably fastened to the other door panel is journaled at one end on a pivot pin provided in the hinge cup, and, in the area where the hinge arm is journaled in the hinge cup, a thrusting means is provided which urges the free panel to a position assuming an angle of slightly more than 900 relative to the first panel hinged on the carcase.
2. The Prior Art
Corner cabinets which fill the corner areas between two rows of built-in cabinets set at right angles to one another are used especially in built-in cabinet layouts intended for kitchens, both on floor cabinets and in wall-hung cabinets. The door closing the corner cabinet carcase is divided, on account of space requirements, into two panels, one of which is hung by conventional hinges--self-closing hinges as a rule--on a supporting wall of the cabinet carcase, while the second, free panel is hinged in turn on the first panel hung on the carcase such that when the door is closed it will be at right angles to the first panel, but after the cabinet is opened it can be swung to a position aligned approximately parallel with the first panel. To hinge the two panels together, so-called piano hinges were originally used, which have the disadvantage, however, that no catch mechanism nor any overdraw restraint can be integrated into them to hold the free panel pressed against the associated part of the carcase in the closed state of the door. Even when the carcase-mounted panel was hung on the carcase with normal over-center hinges, the free door panel then had to be held closed by a separate catch mechanism, a magnetic catch for example. Since such catch mechanisms separate from the hinge mechanism have components to be attached to the carcase, which are visible when the door is open, and which impair the appearance of the (open) corner cabinet and can interfere with access to them, special corner cabinet hinges (DE-OS 37 29 531) have been developed, in which the hinge members turning on one another are coupled by an elongated strap or strip-like connector which is articulated on the one hinge member and slides lengthwise on the other hinge member, wherein the connector is not only part of a catch mechanism but also works as an over-draw restraint which prevents the panels from turning relative to one another beyond a certain angular limit.
One problem of corner cabinet hinges is also that the thickness of the door panels to be coupled together by the corner cabinet hinges varies between, say, 16 and 22 millimeters. Since corner cabinets amount to only a small percentage of kitchen cabinet plans, such corner cabinet hinges are needed relatively rarely, so that due to their complex construction and short production runs in comparison to ordinary cabinet hinges they are sometimes relatively expensive. If corner cabinet hinges of different dimensions would have to be used for door panels of various thickness, this would result in a still further increase in cost. Corner cabinet hinges must therefore be designed so that they will be usable for door panels within the material thickness range in question, i.e., they must be adjustable to the thickness of the panels. Due to the special motion requirements in corner cabinet doors, the adjustability between the hinge arm and the mounting plate in standard hinges does not, as a rule, suffice to cover the entire range of door panels of different thickness by the adjustment of the hinge. Therefore corner cabinet hinges of the kind described above have already been developed (EP-OS 0 463 439) in which the angular hinge arm is additionally divided into sections which are adjustable with respect to one another. The combination of possible adjustments of the hinge arm on a mounting plate and of the arm sections relative to one another then makes it possible to use the same corner cabinet hinge for hanging doors of different thickness.
SUMMARY OF THE INVENTION
It is the object of the invention to offer a corner cabinet hinge whose operation is further improved in comparison to the known corner cabinet hinges, and which can be manufactured economically.
Starting out from a hinge of the kind mentioned in the beginning, this object is achieved according to the invention in that the system for holding doors shut has a pusher mounted displaceably in the hinge cup and resiliently biased toward the pivot pin, and a cam surface which is formed on the bearing sleeve surrounding the pivot pin at the free end of the hinge arm and engaged by the pusher.
In a preferred embodiment of the invention, in which the hinge arm is adjustably mounted on a mounting plate fastened to the door panel, adaptation of the hinge arm to different thicknesses of the panels is accomplished by providing mounting plates of various thicknesses which mount the hinge arm at different distances from the inside surface of the associated door. The actual corner cabinet hinge is thus usable without modification for door panels of different material thickness, and only the mounting plate holding the hinge arm on the associated panel needs to have a different thickness corresponding to the material thickness of the panels, and has to be mounted with its distance from the adjacent panel edge adapted accordingly. Since furthermore, however, the mounting plates commonly used with normal furniture hinges can be used, it is possible to make the hinge arm so as to be able to snapped on and off from the mounting plate in a manner known in itself, which permits rapid and simple installation of the door panels.
Instead of using mounting plates of different thickness for door panels of different material thickness, it is also possible, of course, to use a (thin) standard mounting plate, which in the case of greater door panel thicknesses will be mounted with an appropriate shim on the associated door panel.
In another, different embodiment, the configuration is such that the hinge arm is composed of a total of three arm sections releasably joined together and succeeding one another in the longitudinal direction. The bearing arm section pivotingly mounted in the hinge cup is connected to the middle, connecting arm section for adjustment in a first coordinate direction, and the middle connecting arm section is adjustably joined to the mounting arm section affixed unrotatably to the other door panel for adjustment in a direction running at right angles to the first coordinate direction, and the mounting arm section is in turn mounted for adjustment in a coordinate direction running substantially at right angles to the above-named coordinate directions on a mounting means fastened to the associated door panel.
The configuration is preferably made such that the coordinate direction determining the direction of adjustment between the bearing arm section and the connecting arm section, and the coordinate direction determining the direction of adjustment between the connecting arm section and the mounting arm section, are at right angles to the longitudinal central axis of the pivot pin, and the coordinate direction determining the adjustment direction between the connecting arm section and the mounting arm section are aligned parallel to the longitudinal central axis of the pivot pin. The last-named possibility of adjustment between the connecting arm section and the mounting arm section serves not for adaptation to the thickness of the door panel, but permits the panels to be adjusted for level relative to one another.
The mounting element is best fastened sunken in the associated door panel in the manner of a hinge cup, since in this manner an overall more compact configuration of the hinge is achieved, as well as one less apparent when the door is opened.
The mounting element in that case can best have a bearing surface for an associated fastening surface provided on the mounting arm section, while in the fastening surface there is provided a slot through which passes the shaft of a screw which can be threaded into a tap in the bearing surface. The mounting arm section can then be fastened on the mounting means for adjustment within the length of the slot.
In the confronting mounting and fastening surfaces, it is desirable to provide parallel ridges running at right angles to the slot, which can be forced into positive engagement with one another by tightening the set screw.
In like manner, fastening surfaces can be provided on the mounting arm section and in the connecting arm section, which can brought into contact with one another, a slot being provided in one of the arm sections, through which the shaft of a screw passes which can be driven into a thread in the fastening surface of the other arm section.
Here, again, it is expedient to provide in the confronting fastening surfaces parallel ridges running at right angles to the slot, which are forced into positive engagement by the tightened screw.
Lastly, fastening surfaces which can be brought into contact with one another are provided also in the connecting arm section and in the bearing arm section, the arm sections again being joined adjustably to one another by a screw whose shaft passes through a slot provided in one arm section and into a thread in the fastening surface of the other arm section.
Here too the securing of an adjusted position is best again performed by parallel ridges running at right angles to the slot in the arm section.
If the mounting element is sunken in the manner described above in the associated door panel, it is recommendable to configure the mounting element and the hinge cup on which the bearing arm section pivots as identical components, which thus have not only bores to accommodate a pivot pin inside of the cup, but also as a contact surface for the adjustable mounting of a mounting arm section.
Preadjustment of the corner cabinet hinge to the thickness of the door panels that are to be hinged together becomes possible if a scale enabling the relative positions of the arm sections or parts to one another to be read is provided on the bearing arm section as well as on the mounting arm section and on the mounting means holding it, and a pointer is provided on the other arm section or portion. At the same time the scale can be provided with measurement numbers indicating the correct setting for door panels of a particular thickness.
The configuration of the corner cabinet hinges is advantageous in that the hinge cup in which the free end of the hinge arm is pivoted is provided in the door panel that is hung on the carcase and the hinge arm is thus adjustably fastened on the free door panel.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is further explained in the following description of two embodiments in conjunction with the drawing wherein:
FIG. 1 is a schematic top view of the front of a corner cabinet closed by a bipartite door, with additional cabinets adjoining it on both sides, the door being shown in the closed position. Additionally, the outer panel is shown in an open position separate from the panel hung on the carcase, and also the panel hung on the carcase is shown in broken lines, swung into the open position completely exposing the corner cabinet;
FIG. 2 is a representation corresponding to FIG. 1 of the corner cabinet door swung to the fully open position in front of the adjoining cabinets;
FIG. 3 is an enlarged view of the area represented within the circle 3 in FIG. 1;
FIG. 4 shows the embodiment, represented in FIG. 3, of a corner cabinet hinge according to the invention, partially in a side view and partially cut away;
FIG. 5 is a longitudinal central section through an additional embodiment of a corner cabinet hinge configured in the manner of the invention;
FIG. 6 is a longitudinal central section through the hinge cup of the corner cabinet hinge shown in FIG. 5;
FIG. 7 is a top view of the hinge cup as seen in the direction of arrow 7 in FIG. 6;
FIG. 8 is a side view of the bearing arm section of the corner cabinet hinge shown in FIG. 5;
FIG. 9 is a view of the bearing arm section as seen in the direction of arrow 9 in FIG. 8;
FIG. 10 is a side view of the connecting arm section of the corner cabinet hinge shown in FIG. 5;
FIG. 11 is a view of the connecting arm section, as seen in the direction of arrow 11 in FIG. 10;
FIG. 12 is a longitudinal central section through the mounting arm section of the corner cabinet hinge shown in FIG. 5, and
FIG. 13 is a view of the mounting arm section seen in the direction of arrow 13 in FIG. 12.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows schematically a top view of the front area of a corner cabinet, of which only the two perpendicular carcase side walls 10 and 12 and the bipartite door 14 closing the corner cabinet are shown. The corner cabinet door 14 is composed of two panels 14a and 14b, of which the first panel 14a is hung on the lower, horizontal side wall 14 (although actually the left vertical side wall as seen by looking forward into the cabinet interior) by means of conventional wide-angle hinges 24 provided with an integrated over-center mechanism. At the free vertical edge of this door panel 14b hung on the carcase the second, or free, panel 14b is hung by means of hinges 30 of the invention which will be described in detail below in connection with FIGS. 3 and 4. It is thus possible to open the door 14 of the corner cabinet by first opening panel 14b against the holding force of the hinges 30 linking it in the end position to door panel 14a, this panel 14b being able to be swung to the position represented in broken lines wherein the portion of the corner cabinet heretofore closed by this panel is now accessible. On the other hand, after the partial opening of panel 14b, the door 14 can also swing as a whole to the position shown in FIG. 2 over the laterally adjacent cabinets, and then the part of the corner cabinet that was still closed by door panel 14a is accessible.
In FIGS. 3 and 4 there is shown a first embodiment of the corner cabinet hinge 30 forming the subject matter of the invention. The hinge 30 is basically a single-joint hinge whose mounting members associated with the door panels 14a and 14b are similar to the mounting members of normal hinges. Thus, the mounting part of the hinge associated with door panel 14b is an elongated hinge arm 24 which can be fastened adjustably on a mounting plate 32, and, unlike the supporting arms of hinges for normal cabinets, its multi-angled front end is carried at the joint in a hinge cup 38 mortised in door panel 14a and is mounted for pivoting about a pivot pin held in the hinge cup. The adjustable mounting of the hinge arm 34 on the mounting plate 32 is of the same configuration as in normal hinges, so that the configuration of the hinge arm in this area, as well as the configuration of the mounting plate fastened on the inside of the door panel 14b, does not need to be described in detail. In this special case the hinge arm 34 has in its part that is to be fastened on the mounting plate the usual elongated shape of inverted U cross section, and has at the end remote from the joint, in its upper web joining together the two lateral U-shaped flanges, an open-ended slot 42 (FIG. 4) for a mounting screw 44 (FIG. 3) which can be driven into the mounting plate 32. Toward the joint a tap 46 is provided in the web, into which a screw 48 is driven, on whose bottom end adjacent the mounting plate (not shown) a holding head is provided, which is held at its top for longitudinal displacement in an associated elongated opening that is open at the front end and has a width smaller than the diameter of the holding head. The mounting plate 32, not shown in detail, can otherwise be bipartite in the manner disclosed in German Patent 38 03 830, while the upper part of the mounting plate is releasably held on the bottom part of the mounting plate by a detent means. The use of such a mounting plate has the advantage that the hinge arm 34 fastened on the upper part of the mounting plate can be disengaged quickly and easily from the bottom part of the mounting plate and replaced thereon just as quickly. That is to say, such disengagement can be made very easily and quickly, while the setting of the supporting arm on the mounting plate 32 remains preserved once it has been established.
The hinge cup 38 is sunk in a mortise that breaks through the edge of door panel 14a and is also open at the face, so that the angled front portion at the joint of the hinge arm 34 can pass through the opening in the circumferential wall.
A thrusting means is integrated into the hinge cup and consists of a pusher 50 which is guided for displacement in a mating opening 52 in the hinge cup and is urged by a coil spring 54 under compression out of the opening 52 into engagement with a cam surface 56 which is formed on the bearing sleeve 58 at the free end of the hinge arm 34 containing the pivot pin 40. The shape of the cam surface 56 and the associated end of the pusher 50, which are forced against one another under bias, are selected in the closed position of the corner cabinet shown in the closed position in FIG. 3 such that the door panel 14b is urged slightly still further in the direction of an enlargement of the right angle beyond the position of the door panels shown in the Figure at 90° to one another. This assures that the margin of the panel 14b will be urged in any case into contact with the carcase side wall 10.
In FIG. 5 there is shown a second embodiment of a corner cabinet hinge identified generally as 60 which, as regards the configuration of the mounting part held in the door panel 14a and configured as a hinge cup and the thrusting means provided in this mounting part, is identical to the hinge cup 38 of the embodiment described in FIGS. 1 to 4 and is also provided with the same reference number, so that it is sufficient in regard to the hinge cup 38 to describe hereinafter only those additional improvements which relate especially to the corner cabinet hinge 60. These additional improvements are made so as to be able to use the hinge cup also (instead of the mounting plate 32 provided in the case of hinge 30) as a mounting means (38') that can be sunk in door panel 14b for the adjustable mounting of the hinge arm here marked 64. The hinge cup 38 shown separately in FIGS. 6 and 7 is provided for this purpose above the opening 52 provided for the accommodation of the spring-biased pusher 50 with a basically flat support surface 66 into which a tap 68 is made at right angles for a screw 70 (FIG. 5). In one or more strip-like areas 72 triangular ridges or ribs project at equal intervals from the upper side of the support surface 66, parallel to the turning axis of the hinge.
The hinge arm 64 in turn is composed of three sections which are adjustable relative to one another, namely a pivot arm section 64a mounted pivotingly in the hinge cup 38 held in door panel 14a (FIGS. 8 and 9), a connecting section 64b (FIGS. 10 and 11) and a mounting arm section 64c (FIGS. 12 and 13) which can be fastened adjustably on the support surface 66 of the hinge cup 38 held in the door panel 14b.
The pivot arm section 64a has at its end in the hinge cup the bearing sleeve 58 that receives the pivot pin 40, and on which the cam surface 56 cooperating with the pusher 50 is formed. The end of the pivot arm section 64a remote from the hinge cup is provided with a basically flat fastening surface 74, and contains a slot 76 running at right angles to the hinge pivot axis, through which the shaft of a fastening screw 78 (FIG. 5) can be introduced and driven into a tap 80 in the connecting arm section 64b. The fastening surface 74 is in ten provided with two strip-like areas 82 in which parallel ridges of triangular cross section are provided, which run at right angles and thus parallel to the hinge pivot axis. Lateral lips projecting beyond the fastening surface 74 straddle the upper confronting part of the connecting arm section 64b and thus constitute a guide running in the direction of the slot 80 for the bearing arm section 64a on the connecting arm section 64b. On the connecting arm section 64b there is formed a fastening surface 86 facing the fastening surface 74 and having parallel ridges or ribs. The fastening surfaces 74 and 86 can thus be drawn together so that the ribs can mesh, by means of the fastening screw 78, thus permitting a longitudinal shifting of the bearing arm section 64a on the connecting arm 64b within the length of the slot 76.
The connecting arm section 64b has a second fastening surface 88 which is the bottom of a groove 90 running parallel to the hinge pivot axis. Through the connecting section a slot 92 opening in the fastening section 88 is created, through which a screw 94 (FIG. 5) can be driven into a tap 96 in a stub 98 of the mounting arm section 64c, the stub being fitted in the groove-like opening 90. The connecting arm section 64b is thus adjustable relative to the mounting arm 64c, parallel to the hinge pivot axis, within the range provided by the length of the slot 92, the adjustment being fixed by pressing together the fastening surface 88 of the connecting arm section 64b and the fastening surface 100 formed on the end face of the projection 98. Here too, ridges running transversely of the slot 92 are provided, which can be brought into engagement in a complementary relationship for positive retention in the set adjustment. The mounting arm section 64c also has a second fastening surface 102 on a projecting tongue 104 through which runs a longitudinal slot 106 with an open end at the free end of the tongue; this fastening surface 102 can be placed against the support surface 66 of the hinge cup 38'. The threaded shaft of the fastening screw 70 can be passed through the longitudinal slot 106 and driven into the tap 68 in the support surface 66. Complementary ridges or ribs of fastening surface 102, which run parallel to the ridges of the strip-like areas 72 of the support surface 66, are again brought into positive engagement when the fastening screw 70 is tightened, thus securing an adjustment made, which can be varied by loosening the fastening screw and shifting the mounting arm section 64c on the support surface 66 and then retightening the screw 70.
In FIG. 13 it can be seen that a scale 108 is engraved on each side of the tongue 104 of the connecting arm section 64c, and with it can be associated pointers 110 that can be read on the hinge cup 38'. Since the scale 108 is marked in such a manner that the settings pertaining to particular thicknesses of the panels 14a and 14b can be established by the pointers, tedious trial-and-error adjustments required when the thickness of the panels changes are eliminated.
A corresponding scale 112 is also provided on the connecting arm section 64b, which with a pointer 114 on the bearing arm section permits the correct adjustment of these two arm sections to the material thickness of the door panels.
I do not limit myself to any particular details of constructions set forth in this specification and illustrated in the accompanying drawings, as the same refers to and sets forth only certain embodiments of the invention, and it is observed that the same may be modified without departing from the spirit and scope of the claimed invention.
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The invention relates to a corner cabinet hinge (30) for hanging a free panel (14b) of a two-panel corner cabinet door (14) on the panel (14a) that is hung by a hinge on the carcase supporting wall. The hinge (30) has two members which are associated one with each of the door panels and which are formed as a hinge cup (38) disposed in one of the door panels, and as a hinge arm (34) mounted rotatably in the hinge cup and adjustably fastened to the other door panel. In the area where the hinge arm (34) is journaled in the hinge cup (38) a thrusting device is provided which in the closed position of the door (14) biases the door panel into a position in which the panel assumes an angle of slightly more than 90°. The thrusting device has a pusher displaceably mounted in the hinge cup and biased against the end of the hinge arm that is journaled in the hinge cup, plus a cam surface formed on this end of the hinge arm, which the pusher attacks.
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BACKGROUND
[0001] 1. Field of the Invention
[0002] The present invention relates to the field of computing device interfaces and, more particularly, to user positional anchors for directional, user controlled audio playback from voice-enabled interfaces.
[0003] 2. Description of the Related Art
[0004] Voice-enabled interfaces are able to accept and process speech input and/or to produce speech output. Voice-enabled interfaces are particularly advantageous for interacting with mobile and embedded computing devices which often have limited input/output peripherals due to their compact size and/or restrictions of their intended operational environment. Speech based interactions can be highly advantageous in situations where a device user is performing one or more tasks that require focused attention (e.g., driving or walking). For instance, media playing mobile devices and/or mobile telephones can be potentially dangerous when they require a user to look at a LCD screen and to manipulate selection controls with their hands. Despite this potential danger, visual and tactile based controls remain the most commonly implemented and used interactive mechanisms for mobile computing devices.
[0005] One reason that visual/tactile interactions remain predominant is that conventional voice-enabled interface controls are cumbersome to use in many common, re-occurring situations. For example, a device that audibly enumerates long playlists of selectable songs can quickly try a user's patience. Indexing a large set of songs by artist, album, and/or customizable playlists and then audibly presenting organized subsets of songs mitigates the problem to some extent and in some instances, but fails to resolve underlying systemic flaws.
[0006] For instance, hard drive equipped music playing devices can include hundreds of songs by a user preferred artist so that audibly enumerating available songs by the preferred artist results in too many entries for a user's comfort. In contrast, a user is able to quickly identify a desired song from a complete list of songs presented upon a scrollable visual display. What is needed is a new mechanism for interacting with computing devices that minimizes an amount of time a user is distracted by interactive controls (i.e., so that a user is not endangered while performing concurrent activities, such as driving), yet which permits a user to quickly target a desired item from a potentially large listing of items.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] There are shown in the drawings, embodiments which are presently preferred, it being understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown.
[0008] FIG. 1 is a schematic diagram of a device that includes audio anchors for directional audio playback from a user designated position.
[0009] FIG. 2 is a flow diagram showing a use of audio anchors in accordance with an embodiment of the inventive arrangements disclosed herein.
[0010] FIG. 3 is a diagram of an interface for using audio anchors in an interface having vertically arranged and horizontally arranged elements in accordance with an embodiment of the inventive arrangements disclosed herein.
DETAILED DESCRIPTION OF THE INVENTION
[0011] FIG. 1 is a schematic diagram of a device 100 that includes audio anchors for directional audio playback from a user designated position. An audio anchor can be a configurable position in an interface from which interface content is audibly presented. An audio anchor effectively establishes a user configurable point of focus for audio playback purposes. Playback from an audio anchor can be in a forwards direction (i.e., audibly presenting items of an enumerated list from top to bottom starting at the audio anchor), or in a backwards direction (i.e., audibly presenting items of an enumerated list from bottom to top starting at the audio anchor). When playback is for content having horizontally arranged elements as well as vertically arranged ones (i.e., audible playback of a Web page as opposed to a list of items) the forward direction can indicate presenting content from left-to-right and/or from top-to-bottom from the audio anchor. Similarly, the backward direction can play content from right-to-left and/or from bottom-to-top from the audio anchor.
[0012] In various contemplated configurations, a rate of playback speed can be adjusted by a user. Further, audio samples can be played (e.g., an audio fast forward or audio reverse capability) to allow a user to quickly skip through audibly played content. When audio fast forwarding capabilities exist, a user can configure a sample duration of playback before skipping to another playback position and/or a distance of each audio skip. Additionally, in one embodiment a direction and speed of playback can be adjusted in proportion to a distance between a playback point and a previously established audio anchor. Thus a skip distance for an audio fast forwarding operation can automatically increase as distance from the audio anchor increases.
[0013] As illustrated, the device 100 can include an audio transducer 110 , a voice user interface 116 , an anchor processor 120 as well as an optional set of tactile controls 114 and an optional display 112 . In various embodiments, the device 110 can be a media player, an entertainment system, a mobile phone, a desktop computer, a laptop computer, a navigation system, an embedded computing device, a standalone consumer electronic device, a kiosk, and other such devices.
[0014] The audio transducer 110 of device 100 can include a speaker and/or microphone which plays audio output and/or accepts audio input. Audio interactions between a user and the device 100 can occur via the voice user interface (VUI) 116 . The VUI 116 can be a voice-only interface or can be a voice interfacing component of a multimodal interface. The display 112 and/or tactile controls 114 can be selectively included in embodiments that visually present content and/or that accept tactile input. The device 100 can also include one or more speech processing components (not shown) or be communicatively linked via a transceiver (not shown) to a speech processing system. The optional speech processing components can include a speech recognition engine for processing received audio input and/or a speech synthesizer for generating speech output from text. Speech output from device 100 need not be output converted from text, but can instead result from a playing of stored audio files that contain encoded speech. Audio anchors can be established and manipulated by the tactile controls 114 , by voice commands, and/or by GUI based controls.
[0015] The anchor processor 120 can handle operations related to audio anchors, such as establishing audio anchors, removing audio anchors, setting audio anchor parameters, modifying device 110 behavior in accordance with established audio anchor parameters, playing content from an audio anchor, and the like. The anchor processor 120 can utilize one or more configuration parameters 124 - 127 , which can be stored in memory space 122 . The configuration parameters can include an anchor position 124 , an anchor direction 125 , an anchor magnitude 126 , an anchor mode 127 , and the like.
[0016] The anchor position 124 can specify a user established point within content that is to be audibly presented. The anchor direction 125 can indicate whether playback from the anchor point is to be forward, backward, from top-to-bottom, from bottom-to-top, from right-to-left, from left-to-right, and the like. The anchor magnitude 126 can include a rate of playback. The anchor magnitude 126 can also indicate a skipping distance and/or sampling duration for audio fast forwarding operations. The anchor mode 127 can be a configurable mode used to interpret a meaning intended for overloaded operators. For example, if the anchor mode 127 is in an audio fast forwarding configuration, pressing an overloaded tactile control (e.g., a minus sign or a less than arrow) can indicate that a skipping distance is to be decreased. When the anchor mode 127 is in a playback rate configuration, pressing the same control as before (e.g., a minus sign or a less than arrow) can decrease an audio playback rate.
[0017] FIG. 2 is a flow diagram showing a use of audio anchors in accordance with an embodiment of the inventive arrangements disclosed herein. The processes shown in FIG. 2 can be performed by a computing device, such as computing device 100 , which has been configured to use audio anchors. Throughout the diagram, a set of tactile input controls 215 and a display 230 are used to illustrate concepts of the audio anchor. Controls 215 and display 230 are optional components of a device that uses audio anchors, which only requires a voice user interface that audibly plays back content relative to a user configurable audio anchor. That is, the voice user interface can be an interface of a device having a voice-only modality or the voice user interface can be an interface of a multi-modal device.
[0018] In one arrangement, speech processing technologies can use a set of voice commands to establish and utilize audio anchors (as opposed to utilizing controls 215 ). Any of a variety of different voice commands (e.g., “anchor” for establishing an audio anchor, “faster” for increasing a speaking rate, “slower” for decreasing a speaking rate, “reverse” for changing an enumeration direction, and the like) can be used.
[0019] The tactile controls 215 can include any of a variety of controls, such as a main selector 220 , a mode control 222 , a magnitude control 224 , a backward direction control 226 , and a forward direction control 228 . Each of the controls 215 can be overloaded. The display 230 can include a list of interface items 232 . One of the interface items 232 can have focus 234 that can be visually indicated in display 230 . The controls 215 and display 230 are to illustrate concepts only and the illustrated arrangement is not to be construed as a limitation of the scope of the device.
[0020] For example, in one contemplated embodiment (not shown), the controls 215 can include a Force Sensing Resistor (FSR) region, such as a region of a click wheel control used for many popular media playing devices (e.g., the IPOD). A rate of movement of a finger along the FSR region can determine a speed of a fast-forward or operation and/or a magnitude of a change made to a playback rate. In other embodiments, controls 215 can include a scroll wheel, a rotating dial, a twistable handle, an accelerometer, and the like that can each be used to increase/decrease a playback rate, an enumeration direction, and/or a fast-forward/fast-rewind rate.
[0021] FIG. 2 shows that a forward selection 240 can result in the items 232 displayed to be scrolled forward. One of these items (i.e., “Song TC”) can have focus 242 . An anchor selection 250 can be made, which establishes Song TC as an audio anchor 252 . Once the anchor 252 is established, interface items can be audibly enumerated from that anchor position. For example, assuming that a forward direction is established for the audio anchor, Song TC 262 can be played, followed by song TD 264 , followed by song TE 266 , and so forth. Another selection of the main selector 260 as the Song TE 266 is being audibly enumerated (shown by song selection 268 ) can result in a programmatic action executing, where song TE 266 is a required input parameter of the programmatic action. For example, the selection can result 270 in the playing of an audio file corresponding to Song TE.
[0022] It should be emphasized that one advantage of the arrangement shown in FIG. 2 is that a user can quickly glance at display 230 and manipulate controls 215 to get “close” to a desired region. When “close”, an audio anchor 252 can be established and a user can listen to audibly enumerated interface items. Thus, an amount of time that a user's attention is focused on a display 230 is considerably less than an amount of time needed to perform a fine grained selection of an exact item. In various scenarios, even the brief time needed to focus on a display 230 to place the audio anchor 252 may be disadvantageous in which case the audio anchor 252 can be positioned based on an exclusive use of speech output. Similarly, speech input can be used instead of input from tactile controls 215 in scenarios where complete hands free operations is advantageous.
[0023] FIG. 3 is a diagram of an interface 310 for using audio anchors in an interface having vertically arranged and horizontally arranged elements in accordance with an embodiment of the inventive arrangements disclosed herein. The interface 310 can be one contemplated interface for device, such as computing device 100 , which has been configured to use audio anchors. Elements included in interface 310 are for illustrative purposes only and the invention is not to be construed as limited to details expressed in interface 310 .
[0024] The interface 310 can include interface items for contacts, relation, phone, an item list, and user comments. An audio anchor 330 can be established near the relation element. An anchor direction 332 of forward and an anchor magnitude 334 of four can be established. The magnitude 334 can indicate a rate of speech playback, which can be adjusted. A forward anchor direction can include that items are to be enumerated from left-to-right and from top-to-bottom starting at the audio anchor 330 . Thus, a voice user interface 340 can audibly enumerate “Select relation . . . Family” followed by “Item List . . . Item A; Item B, Item C; Item D” followed by “Phone . . . 555-1234” as shown. If the audio direction 332 were set to backwards, then voice user interface 340 could audibly enumerate “Select Contact . . . Jim Smith.”
[0025] The present invention may be realized in hardware, software, or a combination of hardware and software. The present invention may be realized in a centralized fashion in one computer system, or in a distributed fashion where different elements are spread across several interconnected computer systems. Any kind of computer system or other apparatus adapted for carrying out the methods described herein is suited. A typical combination of hardware and software may be a general purpose computer system with a computer program that, when being loaded and executed, controls the computer system such that it carries out the methods described herein.
[0026] The present invention also may be embedded in a computer program product, which comprises all the features enabling the implementation of the methods described herein, and which when loaded in a computer system is able to carry out these methods. Computer program in the present context means any expression, in any language, code or notation, of a set of instructions intended to cause a system having an information processing capability to perform a particular function either directly or after either or both of the following: a) conversion to another language, code or notation; b) reproduction in a different material form.
[0027] This invention may be embodied in other forms without departing from the spirit or essential attributes thereof. Accordingly, reference should be made to the following claims, rather than to the foregoing specification, as indicating the scope of the invention.
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The present invention discloses a concept and a use of audio anchors within voice-enabled interfaces. Audio anchors can be user configurable points from which audio playback occurs. In the invention, a user can identify an interface position at which an audio anchor is to be established. The computing device can determine an anchor direction setting, with values that include forward playback and backward playback. Interface items can then be audibly enumerated from the audio anchor in a direction indicated by the anchor direction setting. For example, if a set of interface items are alphabetically ordered items and if an audio anchor is set at a first item beginning with a letter “G” and an anchor direction is set to indicate backward playback, then the interface items beginning with letters “A-F” can be audibly played in reverse alphabetical order. Additionally, a rate of audio playback can be user adjustable.
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FIELD OF THE INVENTION
The invention is in the field of computer systems which utilize high speed multi-processors which communicate with each other across backplane and cabinet boundaries and describes a technique to resolve synchronization problems caused by propagation and other delays inherent in such an environment.
BACKGROUND OF THE INVENTION
High speed multi-processor systems depend on high-speed communication between individual processor cells within an array of cells. In a typical design, each processor cell is comprised of a central processing unit and its associated local memory, and communicates with four of its neighbors over high speed (e.g., 40 Mbyte/sec) data channels.
Pathways of processor cells in close electrical proximity (those communicating with cells located on the same printed-circuit board or on the same backplane) communicate in what is referred to near-neighbor mode; data is generated in the transmitting cell, propagated over printed circuit board traces, is accepted by the receiving cell, and is utilized by the receiving cell immediately after its reception. This simple communication method is possible because the sum of clock skew (i.e., misalignment of clock edges arriving at different cells), data transmission delay, and setup time is less than the period of the system clock. In short, nothing special need be done to the data because it arrives soon enough to be used immediately.
When cells must communicate across backplane or cabinet boundaries, data is typically transmitted differentially over cables. This introduces propagation delays caused by the differential transceivers used to drive the cable and by the speed-of-light delay of the cable itself. This creates two design problems. First, the addition of the transceiver propagation delay and the cable propagation delay make the transmitted data arrive at the receiver too late to be immediately used. Second, different systems may use different combinations of backplanes, cables, and cabinets. Neither the system software nor system hardware is aware of the physical configuration of the system, and so neither can compensate for these additional delays.
Much of the recent work in data synchronization has been done in token-ring systems. These are usually fully asynchronous systems (the clocks in different units can differ in both frequency and phase) that use bit-serial communication. Because the operating frequency of transmitter and receiver can be different, these systems must constantly re-synchronize the bit streams they are exchanging. This, of course, comes at the expense of the maximum communication bandwidth of the system.
One such prior art system uses what is known as an ATT T1 PCM transceiver which is an interface supporting bit-serial digital communication over T1 phone lines. It uses an elastic buffer (essentially a First-In-First-Out (FIFO) buffer) whose depth grows and shrinks to accommodate the differing timing relationship of the transmitting and receiving systems. In this transceiver, the framing sync (synchronizing the start of long packets of information) is accomplished in firmware by using an internal microprogrammed microprocessor. Bit sync (synchronizing individual bits in a bit stream once framing sync has been established) is accomplished by hardware in the receiver. This system is flexible and easily changed, but it consumes a good deal of silicon area, is overkill for simple systems (like the phase-asynchronous system of the present invention), and requires that some of the ring data bandwidth be taken up by the transmission of re-synchronizing START bits.
Another prior art system is the IBM Token-Ring adapter which is similar in function to the ATT T1 PCM transceiver. In the IBM system, however, the synchronization occurs in the transmitter. A microprogrammed microprocessor implements an elastic buffer in firmware. This system shares the advantages and disadvantages of the ATT T1 PCM transceiver.
A third system is an interface in a system known as a Cambridge Fast Ring which is comprised of an Emitter Coupled-Logic (ECL) repeater chip and a CMOS control-logic chip. Synchronization is implemented in hardware on the CMOS chip, and is part of the transmitter. Because this approach uses dedicated hardware rather than the microprocessor used in the above examples, it is particularly suited for use in systems using crowded microprocessor chips. However, it shares with the other prior art systems a need to receive a START bit periodically to resynchronize. In addition, it is also a bit-serial approach, as opposed to the parallel approach of the present invention.
BRIEF SUMMARY OF THE INVENTION
A system is disclosed which enables processor cells in a high speed multi-processor environment to communicate with each other so as to resolve synchronization problems caused by propagation and other delays inherent in such an environment.
Like the fully asynchronous token-ring prior art systems described above, the data delay between cells in a system according to the present invention is unknown a priori. Unlike the token-ring systems, however, the data delay in the present system is both bounded and fixed. Because pathways of the invented system communicate only within the environment of the invented system, the maximum data delay is part of the system specifications. This fact, along with the fact that all cells are operating at the same frequency, allows for a synchronization scheme called far-neighbor mode. In this mode, data is transmitted along with a clock to allow the receiving cell to properly recover the data regardless of the state of the receiver's internal clocks. Both the transmitting cell and the receiving cell are operating at the same frequency (because their clock signals are derived from the same master oscillator), but the range of delays associated with the transmission of data places no bounds on the allowable phase difference between the received data's clock and the receiver's internal clock state. The communication, then, is phase-asynchronous.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block overview diagram of a multiprocessor cell arrangement according to the present invention.
FIG. 2 is a block diagram of a single processor cell.
FIG. 3a is a timing diagram showing the assembly of a data word in near-neighbor mode.
FIG. 3b is a timing diagram showing the assembly of a data word in far-neighbor mode.
FIG. 4 is a block diagram of a pathway unit of a cell.
FIG. 5 is a block diagram of a data synchronizer.
FIG. 6 is a block diagram of sync detect 45.
FIG. 7 is a block diagram of FIFO 61.
DETAILED DESCRIPTION OF THE INVENTION
High speed multiprocessing systems depend on high-speed communication between individual processor cells 11 in an array of cells 13 as shown in FIG. 1. In a typical design, each processor cell is comprised of a central processing unit and its associated local memory, and communicates with four of its neighbors over eight high speed (e.g., 40 Mbyte/sec) unidirectional data channels 17a-17d (four input and four output). Also shown in FIG. 1 are loopback lines 19 which are coupled to the cells at each end of a row and at each end of a column and are used so that all cells in an array are identical without regard to their position. Each input/output channel pair is called a physical pathway. In a preferred embodiment, pathways pass a complete word as four thirteen-bit packets, one transmitted each system-clock period.
A single array cell 11 is shown in FIG. 2 wherein the circuitry which forms the present invention is part of the cell's communication unit 31. This circuitry is referred to as the pathway unit 37 whose inputs and outputs are the data channels 17a-17d. The remaining elements in the cell are typical processor elements such as a register file, ALU, ROM, instruction decoder and the like.
Pathways of processor cells in close electrical proximity (those communicating with cells located on the same printed-circuit board or on the same backplane) communicate in what is referred to as near-neighbor mode; data is generated in the transmitting cell, propagated over printed circuit board traces, is accepted by the receiving cell, and is utilized by the receiving cell immediately after its reception.
In far neighbor mode, i.e., when cells must communicate across backplane or cabinet boundaries, data is transmitted differentially over cables. This introduces propagation delays caused by the differential transceivers used to drive the cable and by the speed-of-light delay of the cable itself.
The introduced propagation delays create a synchronization problem which the pathway units of the invention solve by providing self-synchronizing FIFO's for data incoming to each cell. In this manner, cells which are in close electrical proximity can communicate in near-neighbor mode, where both the clock skew and data delay between the microprocessors are small enough that transmitted data can be used in the same internal clock phase in which it is received, or in far neighbor mode where it is necessary to account for the propagation delay. FIG. 3a shows data packets in near-neighbor mode being transmitted, received after a short delay, and used internally as soon as the last packet of a word has been received. FIG. 3b shows data packets in far neighbor mode being transmitted, received after a relatively long delay, and used internally as soon as the last packet of a word has been received.
Referring to FIG. 4, a pathway unit 37 comprises a pathway control table including a data buffer 35 and a pin buffer 38 having word sequencing circuitry 39 and synchronizers 40. The remaining elements of the pathway control table, namely routing state, arbitration and scheduling, next cell's buffer depth and routing pool are shogun for completeness, but do not form part of the present invention and, therefore, will not be described herein. Additionally, this description assumes a system in which the processor cells have a 32 bit internal architecture with each pathway having 8 dedicated pins thereby requiring four clocks to transmit a complete 32 bit word in groups of 8 bits per clock. The description also assumes that each 8 bit group has 5 bits for parity and control and a single bit for a data clock. Of course, other configurations are possible without departing from the invention.
In near-neighbor mode, a fully-assembled data word is available to data buffer 35 within a pathway unit 37 the phase after the word's fourth packet is received as shown in FIG. 3a. Thus, no special attention need be paid to synchronizing this data. The clock skews and data delays encountered when passing data between card cages or system cabinets, however, makes this sort of communication impossible at the frequency used by a fast system clock, e.g., greater than 12 MHz. For this reason, microprocessor cells in the present invention transmit data with a clock signal, and both pass through the same transmission path. The data is then recovered and synchronized by the receiving cell as described in detail below.
As noted above, FIG. 3b shows data packets in far-neighbor mode being received after a relatively long transmit propagation delay, and the assembled data word waiting to be used by the receiving cell. Both the data propagation delay and the clock skew are unknown in the general case; data can be delayed by from one to four system clock periods without affecting bus utilization, and the system specifications place no constraints on the allowable phase shift between microprocessor clocks on different backplanes. In fact, the transmission-line nature of intercell connections allows an arbitrary amount of data to be staged on a properly terminated cable, limited only by the length of the cable.
When a communication pathway is operating in far-neighbor mode, the received data needs to be synchronized with the clock state of the receiving cell 11 because the incoming data packets are not being received in the proper clock phase to be utilized by the receiving cell. Data synchronization could be implemented in either the transmitter (by delaying output data to match the system delay) or in the receiver (by staging input data, holding it until it is required). However, because the cells of the present invention do not acknowledge receipt of data packets, communication resources would have had to be sacrificed to implement the feedback required to place the synchronizer in the transmitter. Placing the synchronizer in the receiver, however, allows data delay to be measured and acted upon locally in the receiving cell. Referring to FIG. 4, this task is accomplished by the data synchronizers 40 (one per data channel) of the pathway unit 37. The synchronizers are part of a pin buffer 38 which also includes word sequencing circuitry 39 (one per data channel) which takes parallel data from data buffer 35, adds parity and control and places the data, parity and control onto one of the four data channels 17a-17d. In particular, for a system using cells with a 32 bit internal architecture, when a cell is transmitting data, a 32 bit data word is stored in data buffer 35 which passes the word to the word sequencing circuitry 39 for transmission during the course of four system clocks, there being 8 data bits per clock for a system dedicating 8 pins per pathway. The word sequencing circuitry, although not necessary for operation of the invention, adds to each of the 8 data bits parity and control signals as may be dictated by system requirements, and a clock. Thus, for a system having 5 control and parity bits in addition to the data bits, a total of 14 lines are used (13 data and 1 clock).
Data entering one of the microprocessor's communication unit's 31 four communication pathways 17a-17d passes first through a corresponding variable-threshold input buffer 41 then into the appropriate 1 of 4 data synchronizers 40. The details of a single data synchronizer is shown in FIG. 5 with an input buffer 41 and includes sync detect circuitry 45, write counter 47, read counter 49 and FIFO 43. When a pathway is operating in near-neighbor mode the data bypasses the synchronizing logic over line 50 directly into multiplexor 51 and feeds the data buffer 35 for the pathway unit 37 of the communication unit 31. In this connection, the pathway is assumed to be operating in far-neighbor mode unless the program being executed by the cell issues an instruction to reconfigure the pathway to operate in near-neighbor mode. When a pathway is operating in far-neighbor mode, the incoming data packets generally are not received in the proper clock phase to be utilized by the receiving cell 11. They are, therefore, staged in variable-length FIFO 43 and read out when they are required. Since the combination of clock skew and data propagation delay are unknown, the length of the FIFO must be adjusted to match the received data.
To facilitate synchronization, a pathway transmits synchronization (SYNC) words after leaving the RESET state and whenever no other data is being transmitted over the pathway. In this connection, a RESET occurs when a reset pin on the cell is asserted such as during an initial power-up or by user intervention. Since a check for synchronization is made only after leaving the RESET state, the SYNC words may be any relatively unique pattern, notwithstanding that it is possible that the same pattern could appear as part of normal data. A suitable SYNC word sequence is a four packet group containing 555555AA 16 or other pattern such that the SYNC word contains a data value in the first transmitted packet which differs from those in the other three packets.
Each synchronizer 40, upon leaving RESET, waits for the arrival of the first packet of the SYNC word. When this word has arrived, the receiver's FIFO 43 begins to fill. Data packets are read out of the FIFO by the signals Read0, Read1, Read2 and Read3, Read400 as shown in FIG. 7 and described below and into the communication unit's data buffer 35 based on the internal clock state of the receiving cell, synchronizing the data. Each data synchronizer (see FIG. 5) includes the FIFO 43, sync detect 45, write counter 47 and read counter 49. The FIFO is implemented as a five-deep circular buffer of edge-triggered flip-flops or master-slave latches 61 which are clocked as a function of the received data clock and the state of the write counter 47 with the write counter serving as a write pointer into the circular buffer, sequentially directing data into FIFO 43. FIFO 43 is shown in FIG. 5 as also including read multiplexor 51 and demultiplexor latches 61; data is clocked into the appropriate latch based on the state of write counter 47. Once the sync detect circuitry 45 enters the In-Sync state, successively-received data is written into successive latches Latch 0, Latch 1, Latch 2, Latch 3, Latch 4 as one of Write0, Write1, Write2, Write3 and Write4 are asserted in succession. One of the five latch outputs 61 is selected by the state of the read counter 49 as one of Read0, Read1, Read2, Read3 and Read4 are asserted in succession causing the data to be passed by transmission gates 81 to input buffer 35. Of course, if the cell has been programmed to run in near-neighbor mode, Latch0-Latch4 are bypassed and the incoming data is passed directly to transmission gate 83 for transfer to input buffer 35.
The write counter 47 and read counter 49 are both three-bit-five-state synchronous counters implemented using transparent latches in a master-slave configuration. A cross-coupled latch 79 generates the required non-overlapping clocks. This latch, which has as its inputs the internal clock of the cell and write counter Enable, ensures that read counter 49 does not start during the same internal clock state in which write counter 47 starts. The maximum delay added by this latch is one complete word time, which for 32 bit words taken 8 bits at a time is four clocks. The write counter 47 is held in a COUNT=0 state until the sync detect circuitry 45 enters the In-Sync state (when synchronization is acquired). The read counter 49 is held in the COUNT=0 state until the clock state of the receiver is correct for the acceptance of the first data packet of a data word after the acquisition of the received pin data into an edge-triggered latch 73), looking for the packet containing the SYNC pattern. This packet indicates the start of a transmitted word. The sync detect circuitry, as shown in FIG. 6, includes loss of clock detect logic 71, master/slave data latches 73 and packet=sync? logic 75, which detect whether the latched data packet matches the SYNC pattern, changes the state of a clocked set/reset latch 77 and puts the sync detect circuitry 45 in the In-Sync state and Write Counter Enable is asserted. Loss of clock detect logic 71 determines whether data is being received by checking for the presence of the data clock so long as the internal clock signal is present. This logic may be implemented by ensuring that there is at least one receive clock after every four internal clocks. Four internal clocks are used since that ensures that an error situation is detected before a complete 32 bit word has been assembled. Systems having different length words would utilize a different number of internal clocks. The sync detect circuitry remains in the In-Sync state unless the processor again enters the RESET state or unless the sync detect circuitry determines that the received data clock (which would be constantly running under normal conditions) has stopped. In either of these cases, the sync detect circuitry re-enters the Not-In-Sync state, stops passing received data to the rest of the pathway unit 37, and waits for the re-acquisition of synchronization.
As shown in FIG. 7, data from the input pins from one of data channels 17a-17d is presented to the inputs of all five latches 61; data is clocked into the appropriate latch based on the state of write counter 47. Once the sync detect circuitry 45 enters the In-Sync state, successively-received data is written into successive latches Latch 0, Latch 1, Latch 2, Latch 3, Latch 4 as one of Write0, Write1, Write2, Write3 and Write4 are asserted in succession. One of the five latch outputs 61 is selected by the state of the read counter 49 as one of Read0, Read1, Read2, Read3 and Read4 are asserted in succession causing the data to be passed by transmission gates 81 to input buffer 35. Of course, if the cell has been programmed to run in near-neighbor mode, Latch0-Latch4 are bypassed and the incoming data is passed directly to transmission gate 83 for transfer to input buffer 35.
The write counter 47 and read counter 49 are both three-bit-five-state synchronous counters implemented using transparent latches in a master-slave configuration. A cross-coupled latch 79 generates the required non-overlapping clocks. This latch, which has as its inputs the internal clock of the cell and write counter Enable, ensures that read counter 49 does not start during the same internal clock state in which write counter 47 starts. The maximum delay added by this latch is one complete word time, which for 32 bit words taken 8 bits at a time is four clocks. The write counter 47 is held in a COUNT=0 state until the sync detect circuitry 45 enters the In-Sync state (when synchronization is acquired). The read counter 49 is held in the COUNT=0 state until the clock state of the receiver is correct for the acceptance of the first data packet of a data word after the acquisition of synchronization. For this purpose, the clock generator of the processor defines four clock states, one of which indicates the first packet of a data word.
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A system for enabling processor cells in a high speed multi-processor environment to communicate with each other so as to resolve synchronization problems caused by propagation and other delays inherent in such an environment. The invention is for systems for which the data delay is both bounded and fixed wherein the maximum data delay is part of the system specifications and all cells operate at the same frequency. Data is transmitted along with a clock to allow the receiving cell to properly recover the data regardless of the state of the receiver's internal clocks. Both the transmitting cell and the receiving cell are operating at the same frequency (because their clock signals are derived from the same master oscillator), but the range of delays associated with the transmission of data places no bounds on the allowable phase difference between the received data's clock and the receiver's internal clock state.
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BACKGROUND OF THE INVENTION
The present invention relates to a novel process for isolating superoxide dismutase from red blood cells and more particularly to a process for isolating superoxide dismutase from hemolyzed red blood cells by causing proteins having affinity for hemoglobin and superoxide dismutase and other unnecessary proteins to precipitate from the hemolyzed red blood cells in the presence of monovalent inorganic neutral salts and transition metal salts by the application of heat.
Superoxide dismutase is an enzyme which catalyses disproportionation of superoxide O 2 - ions as follows:
2O.sub.2.sup.- +2H.sup.+ →O.sub.2 +H.sub.2 O.sub.2
This enzyme is widely distributed in animal and plant organisms and has the function of eliminating active oxygen from those organisms, which active oxygen is generated in the course of biochemical reactions in the organisms and works as a cytotoxin in the organisms.
Superoxide dismutase obtained in its pure state from the red blood cells of higher animals is a protein metal chelate, which is named "orgotein."
Bovine erythrocyte superoxide dismutase has a molecular weight of 31,200 and consists of two apparently identical sub-units of the molecule, each sub-unit having 151 amino acids, the greater part of the amino acids having a β-type cylindrical structure and the remainder having an α-type spiral structure.
Due to the structures of the amino acids, bovine erythrocyte superoxide dismutase is very resistant to denaturation.
As mentioned above, bovine erythrocyte superoxide dismutase is a protein metal chelate, in which copper and zinc are each contained in an amount of 2 gram atoms per mole of the superoxide dismutase.
The isoelectric point of the superoxide dismutase is near pH 5.5.
Superoxide dismutase is innocuous to living organisms and, immunologically, it cannot be regarded as a foreign material in living organisms and therefore it is an injectable protein.
Pharmacologically, superoxide dismutase can serve as a medicine for treatment of inflammation caused by autoimmune diseases, and, recently, by use of superoxide dismutase, there have been attempts to develop medicines for the treatment of arthritis deformans and chronic rheumatism and for treatment of harmful side effects caused by radio therapy.
Conventionally, several methods of isolating erythrocyte superoxide dismutase, namely "orgotein," from red blood cells, have been proposed. However, those conventional methods have a variety of shortcomings. For instance, the purity and yield of the erythrocyte superoxide dismutase obtained are low and preserved blood cannot be employed for producing the erythrocyte superoxide dismutase by those conventional methods. As a matter of fact, if preserved blood could be employed for producing erythrocyte superoxide dismutase in practice, it would be extremely useful.
More specifically, in Japanese Patent Publication Ser. No. 53-31206, there is disclosed a method of isolating orgotein from hemolyzed red blood cells by subjecting the hemolyzed red blood cells to heat treatment in the presence of salts of divalent metals, such as copper, zinc, cobalt, manganese and magnesium, and causing hemoglobin and carbonic anhydrase to precipitate and removing the same.
In this method, although the hemolyzed red blood cells are treated at a comparatively high temperature for a long period of time, separation by precipitation of unnecessary proteins from the hemolyzed red blood cells for isolation of superoxide dismutase is incomplete and red colored hemoglobin remains in the supernatant solution of the heat-treated hemolyzed red blood cells. The unseparated unnecessary proteins cause degrading of the activity of superoxide dismutase during the next purification process of superoxide dismutase. Furthermore, in this method, when lyophilized red blood cells are employed for isolating superoxide dismutase therefrom, separation and purification of superoxide dismutase are more difficult in comparison with the case where untreated fresh red blood cells are employed.
In Japanese Patent Publication Ser. No. 45-39832, there is disclosed a method of isolating orgotein by treating hemolyzed red blood cells with an organic chlorine compound to form a complex compound of hemoglobin and removing hemoglobin in complex-compound form from the hemolyzed red blood cells. In this method, however, a significant amount of superoxide dismutase is attracted to the complex compound and the yield of superoxide dismutase in the supernatant solution of the hemolyzed red blood cells is decreased by more than 20%.
In the Journal of Biochemical Chemistry, Vol. 224, 6051, there is disclosed another method of isolating superoxide dismutase from hemolyzed red blood cells by use of a chlorine compound. In this method, however, the activity of superoxide dismutase is decreased by at least 20% in the first extraction step, in comparision with the activity of unisolated superoxide dismutase.
These superoxide isolation methods using organic chlorine compounds require a large quantity of organic solvent and therefore are not practical in terms of cost and separation efficiency. Furthermore, when lyophilized blood cells are employed, unnecessary proteins including hemoglobin, to which superoxide dismutase is attracted, remain in the supernatant solution of the hemolyzed red blood cells. Therefore, isolation of superoxide dismutase from tne supernatant solution and purification thereof are extremely difficult.
In Japanese Laid-open Patent Application Ser. No. 49-50195, there is disclosed a further method of isolating superoxide dismutase from hemolyzed red blood cells, which method comprises the steps of subjecting the hemolyzed red blood cells to heat treatment; processing the supernatant solution of the heat-treated hemolyzed red blood cells with a proteolytic enzyme; and filtering the processed supernatant solution and separating and purifying superoxide dismutase from the solution by column chromatography and gel-filtration. The shortcomings of this method are that the steps involved in the process using the proteolytic enzyme are complicated and, when old blood cells or lyophilized blood cells are used for producing superoxide dismutase, superoxide dismutase is tightly bonded to unnecessary proteins contained in the blood cells and therefore purification of superoxide dismutase is extremely difficult.
Finally, in Japanese Patent Publication Ser. No. 53-22137, there is disclosed a method of isolating superoxide dismutase from hemolyzed red blood cells by allowing superoxide dismutase contained in hemolyzed red blood cells to be directly attracted to a weak basic ion-exchange resin. In terms of cost and efficiency, this method, however, is not suitable for separation of such a protein as superoxide dismutase contained in an amount ranging from 0.3 to 0.5 weight percent from other proteins. As a matter of fact, this method cannot be employed for producing a large amount of superoxide dismutase from hemolyzed blood cells.
As described above, those conventional superoxide dismutase isolation methods have a variety of shortcomings and cannot be used in practice.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a novel process for isolating superoxide dismutase from red blood cells by removing unnecessary proteins, including hemoglobin, and a protein having affinity for superoxide dismutase therefrom, which process is simple and efficient for isolating superoxide dismutase.
Another object of the present invention is to provide a process capable of isolating superoxide dismutase not only from fresh red blood cells, but also from preserved red blood cells, with substantially the same high yield of superoxide dismutase.
The inventor of the present invention has discovered that the most significant obstacle to the separation and purification of superoxide dismutase from hemolyzed red blood cells is a certain protein which can easily form a complex compound in combination with hemoglobin and/or superoxide dimutase, and which protein is difficult to separate from superoxide dismutase. This protein, from its behavior during denaturation thereof, is considered to be lipoprotein derived from blood cell membranes, and hereinafter it is referred to as the affinity protein.
The inventor of the present invention has further discovered that the affinity protein can be easily and completely separated from superoxide dismutase by two or three stepwise heat treatments of the hemolyzed red blood cells in the presence of monovalent inorganic neutral salts and transition metal salts.
The present invention is based on the above-mentioned two discoveries.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
When the affinity protein contained in red blood cells and having a strong affinity for superoxide dismutase is processed, for instance, by freezing, lyophilization and treatment by organic solvents, followed by heat treatment, the affinity protein is slightly denaturated in the course of that processing and forms a complex compound in tight combination with hemoglobin and/or superoxide dismutase. Formation of such a complex compound also takes place in the course of aging of red blood cells.
The conventionally encountered difficulty in isolating superoxide dismutase in its pure state from frozen blood cells, lyophilized blood cells and preserved blood is probably due to the presence of a complex of the affinity protein and superoxide dismutase. This is in spite of the fact that frozen blood cells, lyophilized blood cells and preserved blood have been considered to be the most practical superoxide dismutase sources, if superoxide dismutase could be easily separated therefrom in its pure state and with a high yield.
In the present invention, red blood cells that can be employed for isolating superoxide dismutase therefrom are not limited to untreated fresh red blood cells, but aged red blood cells that have preserved for a long period of time, frozen red blood cells and lyophilized red blood cells can be employed as well.
Furthermore, for use in the present invention, while it is preferable to use red blood cells free from blood plasma, red blood cells from which blood plasma has not been completely removed can also be employed without any significant problem.
A process for isolating superoxide dismutase from red blood cells according to the present invention will now be explained. This process substantially comprises two steps.
In the first step, water is added to red blood cells in order to hemolyze red blood cells and facilitate stirring of the hemolyzed red blood cells during the superoxide dismutase isolation process. The amount of water to be added to the red blood cells is 1 to 4 times, preferably 2 to 3 times, the volume of the red blood cells.
The thus formed hemolyzed-red-blood-cell solution is heated at temperatures ranging from 60° C. to 75° C. for 10 to 60 minutes, preferably 65° C. to 70° C. for 25 to 40 minutes, in the presence of a monovalent inorganic neutral salt, such as lithium chloride, sodium chloride, potassium chloride, lithium nitrate, sodium nitrate, potassium nitrate, sodium bromide, potassium bromide, lithium, bromide and ammonium bromide, and a comparatively small amount of a transition metal salt, such as water-soluble salts of copper, cobalt and manganese. Examples of such transition metal salts include Cu(No 3 ) 2 .3H 2 O, CuCl 2 .2H 2 O, CuBr 2 , CuCl, MnCl 2 .4H 2 O, and CoCl 2 .2H 2 O, preferably copper(I) chloride and copper(II) nitrate. The latter copper salts are preferred because they are capable of selectively denaturating the unnecessary proteins and promoting coagulation and precipitation of the same.
The monovalent inorganic neutral salts have the function of separating superoxide dismutase from the affinity protein and unnecessary proteins which mainly include denaturated hemoglobin, by weakening the bonding between superoxide dismutase and the affinity protein and the unnecessary proteins.
The transition metal salts have the function of promoting denaturation of the unnecessary proteins, facilitating precipitation of the unnecessary proteins and isolation of superoxide dismutase from the unnecessary proteins with high purity and a high yield.
For weakening the bonding between superoxide dismutase and the affinity protein and other unnecessary proteins, the concentration of the monovalent inorganic neutral salt in the hemolyzed-red-blood-cell solution is in the range of 0.2 mole to its saturation, preferably in the range of 0.3 mole to 1.0 mole.
As to the transition metal salt, the appropriate concentration of the copper salt is in the range of 1×10 -4 mole to 2×10 -4 mole, while the appropriate concentration of the manganese salt is in the range of 1×10 -3 mole to 2×10 -3 mole.
During the first step, the unnecessary proteins including the affinity protein and hemoglobin are mostly caused to precipitate. The precipitated proteins are removed by filtration. At this stage, there remains a very small amount of the unnecessary proteins in the supernatant of the hemolyzed red blood cell solution.
In the second step, in order to remove the unnecessary proteins still remaining in the supernatant solution of the hemolyzed-red-blood-cell solution, the transition metal salt employed in the first step is further added to the hemolyzed-red-blood-cell solution and the hemolyzed-red-blood-cell solution is heated at temperatures ranging from 60° C. to 75° C. for 10 to 60 minutes, preferably at temperatures ranging from 60° C. to 68° C. for 15 to 30 minutes. The transition metal salt is added until the supernatant solution becomes clear while heating the hemolyzed red blood cell solution. In the particular case of the copper salt, it is added little by little in such a manner that the supernatant solution is slightly colored blue upon completion of the heating.
After cooling the hemolyzed-red-blood-cell solution, the precipitated unnecessary proteins are removed by filtration. As a result, substantially all of the unnecessary proteins are removed, while superoxide dismutase remains in the filtrate without being denaturated.
The filtrate is dialyzed against deionized water and/or a conventional buffer solution to remove the monovalent neutral salt and the transition metal salt therefrom.
From the thus obtained solution, superoxide dismutase is obtained in its pure state by a high purification process including separation by use of dialysis, DEAE cellulose column chromatography and gel-filtration.
Another process for isolating superoxide dismutase from hemolyzed red blood cells according to the present invention comprises the above-described two steps and one additional intermediate step.
In the additional intermediate step, upon completion of the first step, the transition metal salt is further added to the supernatant solution obtained in the first step in an amount ranging from 1×10 -4 mole to 1×10 -3 mole, and the supernatant solution is heated again at temperatures ranging from 60° C. to 70° C. for about 10 minutes. The unnecessary proteins precipitated in this intermediate step can be removed upon completion of this step or later. The other steps in this process are exactly the same as those in the first mentioned process according to the present invention. This second process is capable of increasing the yield of superoxide dismutase in comparison with the first mentioned process.
In connection with this intermediate step, if the amount of the transition metal salt to be added in the first step is increased beyond the amount mentioned previously, with the intermediate step omitted, the final yield of superoxide dismutase is decreased.
Specific examples of the process for isolating superoxide dismutase from red blood cells according to the present invention will now be described. In the following examples, sodium citrate was employed as an anticoagulant for the blood. Furthermore, measurement of the activity of superoxide dismutase was performed in accordance with McCord and Fridovich's method proposed in the Journal of Biochemistry, Vol. 244, 6049 (1969).
EXAMPLE 1
To 255 g of red blood cells obtained from 600 ml of fresh bovine blood, 25 g of sodium chloride, 25 mg of cupric chloride and 600 ml of water were added and mixed. The mixture was heated at 68° C. for 30 minutes. After cooling the mixture, the precipitate was removed by filtration.
25 mg of cupric chloride was added to the filtrate and the mixture was heated at 60° C. for 10 minutes.
While elevating the temperature of the mixture to 65° C. and maintaining that temperature, cupric chloride was further added little by little to the mixture until the supernatant of the mixture was colored to its maximum blue without becoming turbid. As a result, 380 mg of cupric chloride was added in total to the mixturre, taking 20 minutes, and during that period of time, the mixture was continuously heated at 65° C.
After the mixture was cooled, the precipitate was filtered off and the filtrate was dialyzed against deionized water for 48 hours and was then filtered.
The filtrate was dialyzed overnight against 0.0025 M potassium phosphate buffer (pH 7.4) and equilibrated with the same buffer. This solution was filtered, so that 850 ml of the filtrate containing 109,080 units of superoxide dismutase was obtained.
The superoxide dismutase solution was then applied on a DE 52 column (1.9×11.5 cm) (manufactured by Whatman Ltd. under the trade name of DEAE cellulose) previously equilibrated with the above-mentioned same potassium phosphate buffer, so that the superoxide dismutase solution was adsorbed to the column. Gradient elution was carried out using 400 ml of the same buffer in total, with the potassium phosphate concentration thereof ranging from 0.0025 M to 0.075 M. The active fractions of superoxide dismutase were collected and combined and dialyzed and were then lyophilized. The yield of superoxide dismutase in its lyophilized state was 43.0 mg with 96,850 units.
EXAMPLE 2
To 417 g of bovine red blood cells which had been preserved for 2 years at a temperature of -20° C., 55 g of sodium bromide, 30 mg of cupric chloride and 650 ml of water were added and mixed. The mixture was heated at 68° C. for 25 minutes. After cooling the mixture, the precipitate was removed by filtration.
20 mg of cupric chloride was added to the filtrate and the mixture was heated at 60° C. for 15 minutes.
The temperature of the mixture was elevated to 65° C. and 600 mg of cupric chloride was further added, while maintaining that temperature for 15 minutes.
After the mixture was cooled, the precipitate was filtered off, so that 1080 ml of the filtrate was obtained. The filtrate was dialyzed against deionized water for 48 hours and was then filtered.
The filtrate was dialyzed overnight against 0.0025 M potassium phosphate buffer (pH 7.4) and equilibrated with the the buffer. This solution was filtered and was then lyophilized, whereby 285 mg of superoxide dismutase with 206,400 units was obtained. The thus obtained superoxide dismutase was dissolved in 10 ml of 0.0025 M potassium phosphate buffer (pH 7.4) and the superoxide dismutase solution was then applied on a DE 52 column (1.9×11.5 cm) (manufactured by Whatman Ltd. under the trade name of DEAE cellulose) previously equilibrated with the above-mentioned same potassium phosphate buffer, so that the superoxide dismutase solution was adsorbed to the column. Gradient elution was carried out using 500 ml of the same buffer in total, with the potassium concentration thereof ranging from 0.0025 M to 0.075 M. The active fractions of superoxide dismutase were collected and combined and dialyzed and were then lyophilized. The yield of superoxide dismutase in its lyophilized state was 72.5 mg with 179,100 units.
EXAMPLE 3
To 73.5 g of lyophilized bovine red blood cells (corresponding to 210 ml of fresh bovine red blood cells), 30 g of sodium bromide, 20 mg of cupric chloride and 600 ml of water were added and mixed. The mixture was heated at 65° C. for 30 minutes. After cooling the mixture, the precipitate was removed by filtration.
320 mg of cupric chloride was added to the filtrate and the mixture was heated at 60° C. for 15 minutes.
After the mixture was cooled, the precipitate was filtered off. The filtrate was dialyzed against deionized water for 48 hours and was then filtered.
The filtrate was dialyzed overnight against 0.0025 M potassium phosphate buffer (pH 7.4) and equilibrated with the the buffer. This solution was filtered and was then applied on a DE 52 column (1.9×11.5 cm) (manufactured by Whatman Ltd. under the trade name of DEAE cellulose) previously equilibrated with the above-mentioned same potassium phosphate buffer, so that the superoxide dismutase solution was adsorbed to the column. Gradient elution was carried out using 500 ml of the same buffer in total, with the potassium phosphate concentration thereof ranging from 0.0025 M to 0.0075 M. The active fractions of superoxide dismutase were collected and combined and dialyzed and were then lyophilized. The yield of superoxide dismutase in its lyophilized state was 34.5 mg with 76,000 units.
EXAMPLE 4
To 315 g of red blood cells obtained from 30-day-old preserved human blood (in which acid-citrate-dextrose (ACD) was employed as an anticoagulant) were added 30 g of potassium chloride, 25 mg of cupric chloride and 550 ml of water and mixed. The mixture was heated at 68° C. for 30 minutes. After cooling the mixture, the precipitate was removed by filtration.
300 mg of cupric chloride was added to the filtrate and the mixture was heated at 68° C. for 20 minutes.
After the mixture was cooled, the precipitate was filtered off, whereby 920 ml of a clear, light blue filtrate was obtained and the filtrate was dialyzed against deionized water for 48 hours and was then filtered.
The activity of superoxide dismutase contained in the filtrate measured 63,600 units.
EXAMPLE 5
To 105 g of sheep red blood cells which had been preserved at a temperature of 4° C. for 15 days were added 10 g of sodium chloride, 6 mg of cupric chloride, CuCl 2 .2H 2 O, and 250 ml of water and mixed. The mixture was heated at 65° C. for 30 minutes. After cooling the mixture, the precipitate was removed by filtration.
150 mg of cupric chloride, CuCl 2 .2H 2 O, was added to the filtrate and the mixture was heated at 65° C. for 20 minutes.
After the mixture was cooled, the precipitate was filtered off. The filtrate was dialyzed against deionized water and was then filtered.
The activity of superoxide dismutase contained in the filtrate measured 19,860 units.
EXAMPLE 6
To 73.5 g of lyophilized bovine red blood cells were added 30 g of sodium nitrate, 20 mg of cupric nitrate, Cu(NO 3 ) 2 .3H 2 O and 600 ml of water and mixed. The mixture was heated at 65° C. for 25 minutes. After cooling the mixture, the precipitate was removed by filtration.
280 mg of cupric nitrate, Cu(NO 3 ) 2 .3H 2 O, was added to the filtrate and the mixture was heated at 65° C. for 20 minutes.
After the mixture was cooled, the precipitate was filtered off. The filtrate was dialyzed against deionized water and was then filtered.
The activity of superoxide dismutase contained in the filtrate measured 94,300 units.
EXAMPLE 7
To 73.5 g of lyophilized bovine red blood cells were added 35 g of potassium nitrate, 20 mg of cupric nitrate, Cu(NO 3 ) 2 .3H 2 O and 600 ml of water and mixed. The mixture was heated at 65° C. for 30 minutes. After cooling the mixture, the precipitate was removed by filtration.
300 mg of cupric nitrate, Cu(NO 3 ) 2 .3H 2 O, was added to the filtrate and the mixture was heated at 65° C. for 20 minutes.
After the mixture was cooled, the precipitate was filtered off. The filtrate wad dialyzed against deionized water and was then filtered.
The activity of superoxide dismutase contained in the filtrate measured 83,600 units.
EXAMPLE 8
To 210 g of frozen bovine red blood cells were added 35 g of potassium bromide, 30 mg of copper(II) bromide, CuBr 2 , and 520 ml of water and mixed. The mixture was heated at 65° C. for 30 minutes. After cooling the mixture, precipitate was removed by filtration.
400 mg of copper(II) bromide, CuBr 2 , was added to the filtrate and the mixture was heated at 65° C. for 20 minutes.
After the mixture was cooled, the precipitate was filtered off. The filtrate was dialyzed against deionized water and was then filtered.
The activity of superoxide dismutase contained in the filtrate measured 87,500 units.
EXAMPLE 9
To 250 g of fresh bovine red blood cells were added 15 g of lithium chloride, 20 mg of copper(I) chloride, CuCl, and 260 ml of water and mixed. The mixture was heated at 67° C. for 30 minutes. After cooling the mixture, the precipitate was removed by filtration.
320 mg of copper(I) chloride was added to the filtrate and the mixture was heated at 67° C. for 20 minutes.
After the mixture was cooled, the precipitate was filtered off. The filtrate was dialyzed against deionized water and was then filtered.
The activity of superoxide dismutase contained in the filtrate measured 104,200 units.
The following are examples of the second process including the previously mentioned intermediate step according to the present invention.
EXAMPLE 10
To 52.5 g of lyophilized bovine red blood cells were added 15 g of lithium nitrate, 20 mg of cupric nitrate, Cu(NO 3 ) 2 .3H 2 O and 500 ml of water and mixed. The mixture was heated at 65° C. for 30 minutes. After cooling the mixture, the precipitate was removed by filtration.
Upon completion of that first step, 20 mg of cupric nitrate, Cu(NO 3 ) 2 .3H 2 O, was further added to the filtrate and the mixture was heated at 68° C. for 15 minutes. After cooling the mixture, the precipitate was removed by filtration.
1.25 g of cobalt(II) chloride, CoCl 2 .2H 2 O, was added to the filtrate and the mixture was heated at 70° C. for 30 minutes.
After the mixture was cooled, the precipitate was filtered off. The filtrate was dialyzed against deionized water and was then filtered.
The activity of superoxide dismutase contained in the filtrate measured 69,800 units.
EXAMPLE 11
To 60 g of lyophilized bovine red blood cells were added 12 g of lithium chloride, 150 mg of manganese(II) chloride, MnCl 2 .4H 2 O and 600 ml of water and mixed. The mixture was heated at 70° C. for 30 minutes. After cooling the mixture, the precipitate was removed by filtration.
Upon completion of that first step, 15 mg of copper(II) chloride, CuCl 2 .2H 2 O, was further added to the filtrate and the mixture was heated at 70° C. for 20 minutes. After cooling the mixture, the precipitate was removed by filtration.
2.0 g of manganese(II) chloride, MnCl 2 .4H 2 O, was added to the filtrate and the mixture was heated at 70° C. for 30 minutes.
After the mixture was cooled, the precipitate was filtered off. The filtrate was dialyzed against deionized water and was then filtered.
The activity of superoxide dismutase contained in the filtrate measured 69,750 units.
In order to confirm the effect of the monovalent inorganic neutral salt on the efficiency of separation of superoxide dismutase and on the activity of superoxide dismutase obtained, the following comparative tests were conducted by use of sodium chloride as the monovalent inorganic neutral salt.
Comparative Test 1-1
To 52.5 g of lyophilized bovine red blood cells corresponding to 150 ml of fresh bovine red blood cells) were added 15 g of sodium chloride (0.5 M), 20 mg of cupric chloride and 500 ml of water. The mixture was heated at 70° C. for 60 minutes and the formed precipitate was removed by filtration.
To the filtrate was further added 230 mg of cupric chloride and the mixture was heated at 65° C. for 20 minutes. The formed precipitate was removed by filtration.
The supernatant of the filtrate was dialyzed and was then lyophilized, so that superoxide dismutase was obtained.
The activity of the thus obtained superoxide dismutase measured 63,000 units.
Comparative Test 1-2
To 52.5 g of lyophilized bovine red blood cells (corresponding to 150 ml of fresh bovine red blood cells) were added 20 mg of cupric chloride and 500 ml of water. The mixture was heated at 70° C. for 60 minutes and the formed precipitate was removed by filtration.
To the filtrate was further added 230 mg of cupric chloride and the mixture was heated at 65° C. for 20 minutes. In the mixture, the formation of precipitate was incomplete, but the formed precipitate was removed by filtration. The filtrate was colored red brown and it appeared that complete purification by this filtration was impossible. Therefore, 220 mg of cupric chloride was further added to the filtrate, the pH of the filtrate was adjusted to be 5.6 by addition of sodium hydroxide, the mixture was heated at 65° C. for 20 minutes and the precipitate was removed by filtration. From the filtrate, a colorless supernatant (pH 5.8) was obtained.
The supernatant was dialyzed and was then lyophilized, so that superoxide dismutase was obtained.
The activity of the thus obtained superoxide dismutase measured 11,7000 units.
In Comparative Test 1-1, as the monovalent inorganic neutral salt, sodium chloride was added to the reaction mixture in the first step, while in Comparative Test 1-2, no monovalent inorganic salt was added in the first step.
The results of these two Comparative Tests were as follows:
______________________________________ Activity of Superoxide Dismutase Ratio______________________________________Comparative Test 1-1 63,000 units 100.0Comparative Test 1-2 11,700 units 18.6______________________________________
These results show that addition of the monovalent inorganic neutral salt significantly increased the activity of superoxide dismutase.
Furthermore, in order to confirm the effect of the second step, in which the transition metal salt is added to the reaction mixture, on the efficiency of separation of superoxide dismutase and on the activity of superoxide dismutase obtained, the following comparative tests were conducted.
Comparative Test 2-1
In this comparative test, the second step was omitted as follows:
To 52.5 g of lyophilized bovine red blood cells (corresponding to 150 ml of fresh bovine red blood cells) were added 15 g of sodium chloride, 15 mg of cupric chloride and 500 ml of water and mixed. The mixture was heated at 70° C. for 60 minutes and the formed precipitate was removed by filtration. The filtrate was colored red brown. This filtrate was dialyzed and was then lyophilized.
(1) The obtained superoxide dismutase was red brown in color.
(2) The total weight of the proteins obtained was 870 mg.
(3) The enzyme activity of superoxide dismutase was 74,400 units.
(4) The specific enzyme activity of superoxide dismutase was 86 units/protein(mg).
Comparative Test 2-2
In this comparative test, filtration of the precipitate formed in the first step was omitted.
To 52.5 g of lyophilized bovine red blood cells (corresponding to 150 ml of fresh bovine red blood cells) were added 15 g of sodium chloride, 15 mg of cupric chloride and 500 ml of water and mixed. The mixture was heated at 70° C. for 60 minutes.
After cooling the mixture, 1.9 g of cupric chloride was added to the mixture without eliminating the precipitate formed in the first step. With the pH of the mixture adjusted to be 5.6, the mixture was heated at 65° C. for 20 minutes. After cooling the mixture, the precipitate was filtered off, so that 520 ml of a colorless filtrate was obtained.
The filtrate was dialyzed and was then lyophilized.
(1) The obtained superoxide dismutase was light grey green in color.
(2) The total weight of the proteins obtained was 185 mg.
(3) The enzyme activity of superoxide dismutase was 43,200 units.
(4) The specific enzyme activity of superoxide dismutase was 238 units/protein(mg).
Comparative Test 2-3
In this comparative test, both the first step and the second step were performed.
To 52.5 g of lyophilized bovine red blood cells (corresponding to 150 ml of fresh bovine red blood cells) were added 15 g of sodium chloride, 15 mg of cupric chloride and 500 ml of water and mixed. The mixture was heated at 70° C. for 60 minutes and the formed precipitate was removed by filtration.
To the filtrate was further added 215 mg of cupric chloride at 60° C. and the mixture was heated at 65° C. for 15 minutes. After cooling the mixture, the formed precipitate was removed by filtration, so that 500 ml of the light blue filtrate was obtained.
The filtrate was dialyzed and was then lyophilized.
(1) The obtained superoxide dismutase was white.
(2) The total weight of the proteins obtained was 98 mg.
(3) The enzyme activity of superoxide dismutase was 73,250 units.
(4) The specific enzyme activity of the superoxide dismutase was 747 units/protein(mg).
The results of Comparative Tests 2-1, 2-2 and 2-3 can be summarized as follows:
______________________________________ Specific Enzyme Activity Enzyme [Units/Comparative Color of Total Protein Activity ProteinTest S.O.D. Weight (Units) (mg)]______________________________________2-1 Red-Brown 870 mg 74,400 852-2 Light Grey- 185 mg 43,200 238 Green2-3 White 98 mg 73,250 747______________________________________ S.O.D. = Superoxide Dismutase
These comparative tests indicate that omission of the second step significantly reduces the purity of the superoxide dismutase.
The embodiments described are intended to be merely exemplary and those skilled in the art will be able make variations and modifications in them without departing from the spirit and scope of the invention. For instance, in the embodiments described, precipitates formed in the course of the process for isolating superoxide dismutase from red blood cells, are removed by filtration. However, removal of such precipitates can be done by centrifugation or any other methods which are considered equivalent to those separation methods by those skilled in the art. All such modifications and variations are contemplated as falling within the scope of the claims.
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A process for isolating superoxide dismutase from red blood cells comprising the steps of heating hemolyzed red blood cells in the presence of at least one monovalent inorganic neutral salt and at least one transition metal salt; eliminating precipitate from the hemolyzed red blood cells by filtration or centrifugation to obtain a solution; adding further at least one transition metal salt at least once to the solution under application of heat thereto; and eliminating precipitate from the solution.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates generally to the reforming of fuels, and in particular to autothermal reforming methods and apparatus for the production of gas containing hydrogen and carbon oxides, such as methonal synthesis gas (“syngas”), including but not limited to large-scale production of syngas.
[0002] FIG. 1 illustrates a typical vertical packed bed autothermal reformer 10 . A hydrocarbon feed 24 is preheated in a heater 34 . The preheated hydrocarbon stream may then be desulfurized in a separate unit operation (not shown). The preheated hydrocarbon stream is mixed with a portion of a steam feed 32 . The preheated mixture is combined with an oxidant feed 26 within a single burner 28 . The oxidant feed (usually oxygen, air, or a combination) is preheated in a heater 36 . The preheated oxidant mixture is mixed with a portion of the steam feed 32 or steam could be added prior to the preheater. The steam and oxidant mixture is combined with the preheated hydrocarbon mixture within the single burner 28 . A partial oxidation (POX) zone 22 is formed within the autothermal reformer vessel 18 . Partial oxidation (POX) is the non-catalytic, sub-stoichmetric combustion of a hydrocarbon with an oxidant (e.g., oxygen or air) to produce CO and H2 (other products include H2O and CO2). The partially oxidized stream in the POX zone encounters a target brick system 14 and proceeds to a packed catalyst bed 12 . Steam methane reforming and water gas shift reactions occur within the packed catalyst bed. An effluent gas enters a bed support arch 16 and leaves the reformer as a hot syngas stream 38 . The hot syngas stream may be cooled in a process waste heat boiler 42 . The syngas stream 38 may then be further processed as required.
[0003] Typical autothermal reformers are disclosed in EP0936183 A2 and U.S. Pat. No. 5,628,931 (Lednor).
[0004] There are several problems associated with the use of packed catalyst beds 12 in conventional autothermal reformers 10 , such as that illustrated in FIG. 1 . First, the packed catalyst bed 12 can cause appreciable pressure drop, especially for increased process flows/expansions. Second, conventional autothermal reformer/secondary reformer designs are based on a high heat release (in the POX zone) from the single burner 28 and require heavy refractory protection for the vertical vessel 18 . Due to high-velocity jets coming from the single burner, the catalyst bed requires a target brick system 14 for protection. Often, the failure of the target brick system results in attrition of the packed bed catalyst bed. Also, the uni-burner design forces all of the heat to be released in a single compact POX zone, which results in a high peak flame temperature. In addition, the high velocities (low residence time) in the POX zone can increase soot formation and catalyst degradation. Such aggressive operating conditions require additional steam injection, pre-reforming of heavier feeds, etc. to allow reliable operations, all of which result in higher capital and operating costs.
[0005] As discussed below, the prior art discloses various designs and improvements which alleviate some problems associated with the use of packed catalyst beds in conventional autothermal reforming. However, there remains a need for a more comprehensive solution to the problems presented.
[0006] The use of a monolith within a combustor of a gas turbine power plant to produce syngas with some fuel/oxidant staging prior to a catalyst zone is disclosed in U.S. Pat. No. 4,618,451 (Gent). The patent discloses an autothermal reformer wherein the product gas suitable for methanol synthesis is integrated with the turbine.
[0007] A device with a relatively small POX chamber followed by a reforming catalyst bed with additional oxidant and fuel insertions is disclosed in U.S. Pat. No.5,632,787 (Boucot). One configuration is a traverse arrangement where a downflow autothermal reformer is followed by an upflow section and then another downflow catalyst bed followed by additional upflow and downflow sections. Additional firing can be done in later downflow sections.
[0008] EP0312754 B1 discloses a horizontal autothermal reformer, which uses a vertical catalyst section.
[0009] Other patents relating to a monolith within an autothermal reformer involve either improved injectors or catalytic partial oxidation. Catalytic partial oxidation (CPOX) involves the partial combustion of a hydrocarbon with an oxidant over a catalyst at lower temperatures than for non-catalytic partial oxidation. Hence, the CPOX reaction process is significantly different than POX.
[0010] The use of a steam reforming catalytic monolith within an autothermal reformer when used in conjunction with an injector is disclosed in U.S. Pat. No. 5,980,596 (Hershkowitz). The use of a steam reforming monolith in conjunction with a CPOX monolith for ammonia production is disclosed in U.S. Pat. No. 4,863,707 (McShea, III). A monolith secondary reformer is disclosed in EP206535 B1.
[0011] Reforming with O2 staging is disclosed in U.S. Pat. No.6,059,995 (Topsoe), and a staged air autothermal reformer is disclosed in U.S. Patent Application Publication No. 2003/0200699 A1. Hydrocarbon CPOX with O2 staging is disclosed in EP0842894 B1.
[0012] U.S. Pat. No.6,911,193 (Allison) discloses the use of staged O2 and feedstock for a CPOX zone followed by a steam methane reforming (SMR) zone. An article in Chemical Engineering, September 2003, page 17 discloses the use of staged O2 for a mixture of CPOX and SMR catalysts.
[0013] It is desired to have an apparatus and method for reforming a fuel which eliminate the constraints that limit syngas production capacity for a single autothermal reformer, including: uni-burner design, vertical flow configuration, and the need for a transfer line.
[0014] It is further desired to have an apparatus and a method for reforming a fuel which allow an increase in syngas production from a reformer while mitigating the problem of carbon formation.
[0015] It is still further desired to have an apparatus and a method for reforming a fuel in which the requirements for process steam and oxidant are lower than such requirements for conventional autothermal reformers.
[0016] It is still further desired to have an apparatus and a method for reforming a fuel having a more uniform heat distribution than prior art autothermal reformers and providing for operation at higher equilibrium temperatures resulting in higher CO in syngas product and higher volumes of syngas.
[0017] It is still further desired to have an apparatus and a method for reforming a fuel which reduce the complexity of integration of the reformer with downstream heat recovery equipment, and eliminate the need for an expensive transfer line or the risers required in upstream tubular reformers.
[0018] It is still further desired to have an apparatus and a method for reforming a fuel having higher reforming efficiency, additional flexibility for control of the H2/CO ratio, and better reliability than conventional autothermal reformer processes.
[0019] It is still further desired to have an apparatus and a method for reforming a fuel which reduce the overall steam injection requirements needed to mitigate the risk of carbon formation.
[0020] It is still further desired to have an apparatus and a method for reforming a fuel which achieve effluent syngas temperatures higher than that of conventional autothermal reformers and processes, which results in higher carbon monoxide production (lower H2/CO ratio in the syngas).
[0021] It is still further desired to have an apparatus and a method for reforming a fuel which allow for both horizontal and upflow (vertical) configurations.
[0022] It is still further desired to have an apparatus and a method for reforming a fuel which permit the use of multiple burners (each less complex than a uni-burner) which operate at less severe conditions than the conventional uni-burner.
[0023] It is still further desired to have an apparatus and a method for reforming a fuel which eliminate the need for a target brick system such as typically used in conventional autothermal reformers.
[0024] It is still further desired to have an apparatus and a method for reforming a fuel which operate more efficiently than conventional autothermal reformers and processes, and have lower capital and operating expenses than conventional autothermal reformers and processes.
[0025] It is also desired to have an apparatus and method for reforming a fuel which afford better performance than the prior art, and which also overcome many of the difficulties and disadvantages of the prior art to provide better and more advantageous results.
BRIEF SUMMARYOF THE INVENTION
[0026] The present invention is an apparatus and a method for reforming a fuel. There are many embodiments of the invention and many variations of those embodiments.
[0027] A first embodiment of the apparatus includes four elements. The first element is a first partial oxidation zone having at least one burner adapted to partially oxidate at least a portion of a first stage feed of the fuel with at least a portion of a first stream of an oxidant in the first partial oxidation zone, thereby forming a first partially oxidated effluent. The second element is a first catalytic zone containing a first catalyst and being in fluid communication with the first partial oxidation zone and adapted to receive at least a portion of the first partially oxidated effluent, which reacts in the first catalytic zone to form a first stage effluent. The third element is a second partial oxidation zone in fluid communication with the first catalytic zone and adapted to receive at least a portion of the first stage effluent. The second partial oxidation zone has at least one other burner adapted to partially oxidate at least a portion of a second stage feed of the fuel or an other feed of an other fuel with at least a portion of a second stream of the oxidant or an other oxidant in the second partial oxidation zone, thereby forming a second partially oxidated effluent. The fourth element is a second catalytic zone containing a second catalyst and being in fluid communication with the second partial oxidation zone and adapted to receive at least a portion of the second partially oxidated effluent, which reacts in the second catalytic zone to form a second stage effluent.
[0028] A second embodiment of the apparatus is similar to the first embodiment but includes an additional element. The additional element is a means for combining at least a portion of at least one flow of at least one moderator with at least a portion of at least one of (a) the first stage feed of the fuel, (b) the second stage feed of the fuel or the other feed of the other fuel, (c) the first stream of the oxidant, and (d) the second stream of the oxidant or the other oxidant. In a variation of this embodiment, the at least one moderator is selected from the group consisting of steam, carbon dioxide, and mixtures thereof.
[0029] A third embodiment of the apparatus is similar to the first embodiment, but includes at least one protective monolith between at least one of (a) the first partial oxidation zone and the first catalytic zone, and (b) the second partial oxidation zone and the second catalytic zone.
[0030] There are many variations of the first embodiment and the other embodiments discussed above. In one variation, at least one of the first catalyst and the second catalyst is monolithic. In another variation, the fuel is at least in part a hydrocarbon. In yet another variation, the second stage effluent is a product synthesis gas containing hydrogen and carbon monoxide.
[0031] In another variation, at least one of the first catalyst and the second catalyst is a steam reforming catalyst. In another variation, at least one of a steam methane reforming reaction and a water gas shift reaction occurs in at least one of the first catalytic zone and the second catalytic zone.
[0032] In another variation, at least one of the oxidant and the other oxidant is selected from a group consisting of oxygen, air, oxygen-depleted air, oxygen-enriched air, carbon dioxide, steam, and methanol.
[0033] In another variation, the apparatus has a longitudinal axis through each of the first partial oxidation zone, the first catalytic zone, the second partial oxidation zone, and the second catalytic zone, and the longitudinal axis is substantially horizontal.
[0034] In another variation, at least one of the first catalytic zone and the second catalytic zone is in fluid communication with a heat recovery device.
[0035] Persons skilled in the art will recognize that there are many other embodiments and variations of the apparatus of the present invention for reforming a fuel. For example, one such other embodiment includes a combination of all of the elements and limitations set forth above for the first, second, and third embodiments of the apparatus and the variations thereof discussed above.
[0036] A first embodiment of the method for reforming a fuel includes multiple steps. The first step is to provide a first stage feed of the fuel. The second step is to provide a second stage feed of the fuel or an other feed of an other fuel. The third step is to provide a first partial oxidation zone having at least one burner. The fourth step is to partially oxidate at least a portion of the first stage feed of the fuel with at least a portion of a first stream of an oxidant in the first partial oxidation zone with the at least one burner, thereby forming a first partially oxidated effluent. The fifth step is to provide a first catalytic zone containing a first catalyst and being in fluid communication with the first partial oxidation zone. The sixth step is to receive in the first catalytic zone at least a portion of the first partially oxidated effluent, which reacts in the first catalytic zone to form a first stage effluent. The seventh step is to provide a second partial oxidation zone in fluid communication with the first catalytic zone, the second partial oxidation zone having at least one other burner. The eighth step is to receive in the second partial oxidation zone at least a portion of the first stage effluent. The ninth step is to partially oxidate at least a portion of the second stage feed of the fuel or the other feed of the other fuel with at least a portion of a second stream of the oxidant or an other oxidant in the second partial oxidation zone, thereby forming a second partially oxidated effluent. The tenth step is to provide a second catalytic zone containing a second catalyst and being in fluid communication with the second partial oxidation zone. The eleventh step is to receive in the second catalytic zone at least a portion of the second partially oxidated effluent, which reacts in the second catalytic zone to form a second stage effluent.
[0037] A second embodiment of the method is similar to the first embodiment of the method, but includes two additional steps. The first additional step is to provide at least one flow of at least one moderator. The second additional step is to combine at least a portion of the at least one flow of the at least one moderator with at least a portion of at least one of (a) the first stage feed of the fuel, (b) the second stage feed of the fuel or the other feed of the other fuel, (c) the first stream of the oxidant, and (d) the second stream of the oxidant or the other oxidant. In a variation of this embodiment, the at least one moderator is selected from the group consisting of steam, carbon dioxide, and mixtures thereof.
[0038] A third embodiment of the method is similar to the first embodiment of the method, but includes the further step of providing at least one protective monolith between at least one of (a) the first partial oxidation zone and the first catalytic zone, and (b) the second partial oxidation zone and the second catalytic zone.
[0039] There are many variations of the first embodiment and the other embodiments of the method discussed above. In one variation, at least one of the first catalyst and the second catalyst is monolithic. In another variation, the fuel is at least in part a hydrocarbon. In yet another variation, the second stage effluent is a product synthesis gas containing hydrogen and carbon monoxide.
[0040] In another variation, at least one of the first catalyst and the second catalyst is a steam reforming catalyst. In yet another variation, at least one of a steam methane reforming reaction and a water gas shift reaction occurs in at least one of the first catalytic zone and the second catalytic zone.
[0041] In another variation, at least one of the oxidant and the other oxidant is selected from the group consisting of oxygen, air, oxygen-depleted air, oxygen-enriched air, carbon dioxide, steam, and methanol.
[0042] In another variation, there is a longitudinal axis through each of the first partial oxidation zone, the first catalytic zone, the second partial oxidation zone, and the second catalytic zone, and the longitudinal axis is substantially horizontal.
[0043] In another variation, at least one of the first catalytic zone and the second catalytic zone is in fluid communication with a heat recovery device.
[0044] Persons skilled in the art will recognize that there are many other embodiments and variations of the method of the present invention for reforming a fuel. For example, one such other embodiment is a method including all of the steps and limitations set forth above for the first, second, and third embodiments of the method and the variations thereof discussed above.
BRIEF DESCRIPTION OF THE DRAWINGS
[0045] The invention will be described by way of example with reference to the accompanying drawings, in which:
[0046] FIG. 1 is a schematic diagram illustrating a conventional autothermal reformer process;
[0047] FIG. 2 is a schematic diagram illustrating one embodiment of the present invention;
[0048] FIG. 3 is a schematic diagram illustrating another embodiment of the present invention;
[0049] FIG. 4 is a graphic illustration comparing the temperature profiles in the catalyst bed for a conventional autothermal reformer and one embodiment of a staged reformer of the present invention;
[0050] FIG. 5 is a schematic diagram illustrating another embodiment of the present invention illustrating integration of a multi-stage reformer with heat recovery equipment; and
[0051] FIG. 6 is a schematic diagram illustrating yet another embodiment of the present invention illustrating integration of a heat recovery device or heat exchanger with the first and second stages of a two-stage reformer of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0052] An autothermal reformer for the production of syngas uses both fuel staging and oxidant staging, a multi-burner design, and a catalyst that preferably is monolithic, and preferably has a horizontal flow configuration. The autothermal reformer eliminates significant constraints which limit syngas production capacity for a conventional autothermal reformer, such as: uni-burner design (limited by duty from a single burner); vertical flow configuration (limited by catalyst bed weight and the size of arch/dome support); and the need for a transfer line (to transfer syngas from the reformer to downstream equipment).
[0053] As used herein, the term “fuel” includes any fuel which may be used as a feedstock for producing syngas or other gases which contain hydrogen and carbon monoxide products. The fuel may be a liquid, gas, solid, or mixtures thereof. A single type of fuel, or multiple types of fuel, may be used. Preferably, at least one type of the fuels used is in part a hydrocarbon. For example, fuels which may be used alone or in combination include, but are not limited to, natural gas, methane, mixtures of hydrocarbons, hydrogen, and mixtures containing hydrogen and similar fuels.
[0054] As used herein, the term “oxidant” includes any gas, liquid, solid and mixtures thereof containing any form of oxygen which can act as an oxidizing agent. For example, oxidants which may be used alone or in combination include, but are not limited to, air, oxygen, oxygen-depleted air, oxygen-enriched air, carbon dioxide, steam, methanol, and similar oxidants.
[0055] The reforming of a fuel feed in multiple stages allows an increase in syngas production from the reformer, while mitigating the problem of carbon formation. In addition, the overall process steam and oxidant requirements are reduced for the process.
[0056] The staging of both the oxidant feed and the fuel feed allows a controlled heat release distribution and lowers the peak flame temperature. The less aggressive operating conditions allow the use of more active catalysts and eliminate the need for inert sections of catalyst bed and protective target bricks. In addition, the process provides greater operational and commercial flexibility.
[0057] Staging of both the oxidant feed and the fuel feed also permits the use of multiple burners instead of a complex uni-burner. In the multi-burner design, each burner operates at less severe conditions than that of the uni-burner. More aggressive operation can be accomplished as each multi-burner may be run at the uni-burner conditions. Importantly, staging of both the oxidant feed and the fuel feed increases the reformer exit temperature and produces syngas with higher CO contents and higher volume from the reformer. An increase in equilibrium exit temperature does not necessarily result in higher flame temperatures inside the reforming reactor because of the effect of staging and the multi-burner design, which also allows for a more uniform heat distribution.
[0058] A horizontal flow arrangement used in some embodiments of the present invention eliminates the need for any special support for the catalyst, and use of a monolithic catalyst (with lower pressure drop than a packed bed) eliminates most catalyst attrition problems. A staged horizontal autothermal reforming process also reduces the complexity of integration of the reformer with downstream heat recovery equipment, and eliminates the need for an expensive transfer line or the risers required in upstream tubular reformers (for the case where a secondary reformer is used). It also has higher reforming efficiency, additional flexibility for control of the H2/CO ratio, and better reliability than conventional autothermal reformer processes.
[0059] The autothermal reformer uses a steam reforming catalytic monolith instead of a conventional packed bed of steam reforming catalyst within a conventional autothermal reformer (non-catalytic partial oxidation followed by a catalyst bed). The use of a catalytic monolith in place of a conventional fixed bed catalyst has the following advantages:
reduced pressure drop; higher effective surface area for the same catalyst volume; different packing structure substantially reduces catalyst attrition due to thermal expansion; no need for target refractory bricks—thus eliminating the possibility of plugging target bricks due to attrition; the top (inert) portion of the monolith bed organizes the flow paths for the downstream catalyst portion of the bed; the high thermal conductivity of the monolith allows a more uniform temperature profile within the reaction zone (compared to the packed bed) and thus a higher effective equilibrium temperature may be achieved; and all of the above advantages result in a better reforming efficiency.
[0067] A monolith catalyst also provides important flexibility in the design configuration of the autothermal reformer/secondary reformer for specific flowsheet conditions (horizontal and up-flow design). More importantly, it allows organized staged autothermal/secondary reforming processes.
[0068] In addition, the present invention reduces the overall steam injection requirements needed to mitigate the risk of carbon formation. Steam addition is required only to the first stage, while all downstream stages can be operated without steam injection. The first stage will produce steam that may be used to mitigate the risk of carbon formation in the latter stages.
[0069] Persons skilled in the art will recognize that other moderators besides steam may be used. For example, carbon dioxide (CO2) may be used as a moderator alone or in combination with steam or another moderator.
[0070] Referring to the drawings, one embodiment of the present invention involves the use of a catalyst monolith with a hydrocarbon autothermal reformer 50 , as shown in FIG. 2 . A hydrocarbon feed 101 is preheated in a heater 120 . The preheated hydrocarbon stream 102 may be mixed with a portion of steam feed 108 . The steam and hydrocarbon mixture 103 may be staged to different burners 110 . A portion of the preheated hydrocarbon mixture 104 is combined with a portion of the oxidant 180 within a burner 110 . The oxidant feed 105 (usually oxygen, air, or a combination) is preheated in a heater 121 . The preheated oxidant 106 is mixed with a portion of steam feed 108 or steam could be added prior to the preheater. The steam and oxidant mixture 107 may be staged to different burners 110 . A portion of the oxidant 181 may be staged to burner zones. Oxidant stream 182 may be combined with the hydrocarbon stream 191 in the burners 110 prior to the first catalytic zone 113 . The first catalytic zone 113 comprises a monolith catalyst zone. The partial combustion products within the first partial combustion zone 111 enter the first catalytic zone 113 . Prior to any catalytic zone, a non-catalytically active or protective monolith 112 may be provided. Within the first catalytic zone 113 , steam methane reforming and water gas shift reactions occur.
[0071] The product gas then enters the second partial oxidation zone 151 where additional burners 110 provide heat. The oxidant stream 183 may be combined with the hydrocarbon stream 192 within the burners 110 within the second partial oxidation zone 151 . A moderator stream 199 of steam or another moderator (e.g., carbon dioxide) may be combined with the hydrocarbon stream 192 . The partial combustion products in the second partial combustion zone 151 enter the second catalytic zone 114 . Within the second catalytic zone 114 , steam and methane reforming and water gas shift reactions occur. The product gas then leaves the second catalytic zone 114 and enters a process waste heat boiler 116 or other heat recovery (or heat exchange) device. The syngas product 117 may then be further processed as required.
[0072] For illustrative purposes only, only two partial oxidation and two catalytic zones with oxidant and hydrocarbon staging are shown in FIG. 2 . However, any number of additional catalytic zones and partial oxidation zones may be added.
[0073] Also, the hydrocarbon feed 101 may be staged to different partial oxidation zones (as shown) or may be fed preferentially to only one zone. A horizontal configuration is shown, but a vertical upflow design may be operated with the catalyst monolith. A plurality of burners may be provided within each partial oxidation zone.
[0074] Both the oxidant feed and the hydrocarbon feed are staged to at least two sections of the autothermal reactor. The catalyst monolith permits the use of multiple catalyst sections in a horizontal configuration.
[0075] FIG. 3 shows another embodiment of an autothermal reformer 50 of the present invention. The hydrocarbon feed 201 is preheated in a heater 220 . The preheated hydrocarbon stream 202 may be mixed with a portion of steam feed 208 . The steam and hydrocarbon mixture 203 may be staged to different burners 210 . A portion of the preheated hydrocarbon mixture 204 is combined with a portion of the oxidant 280 within a burner 210 . The oxidant feed 205 (usually oxygen, air, or a combination) is preheated in a heater 221 . The preheated oxidant 206 is mixed with a portion of steam feed 208 or steam could be added prior to the preheater. The steam and oxidant mixture 207 may be staged to different burners 210 . A portion of the oxidant 281 may be staged to burner zones. Oxidant stream 282 may be combined with the hydrocarbon stream 291 within the burners 210 prior to the first catalytic zone 213 . The catalytic zone 213 comprises a monolithic catalyst zone. The partial combustion products within the first partial combustion zone 211 enter the first catalytic zone 213 . Prior to any catalytic zone, a non-catalytically active or protective monolith 212 may be provided. Within the first catalytic zone 213 steam methane reforming and water gas shift reactions occur.
[0076] The product gas then enters the second partial oxidation zone 251 where additional burners 210 provide heat. The oxidant stream 283 may be combined with the hydrocarbon stream 292 within the burners 210 within the second partial oxidation zone 251 . The partial combustion products within the second partial combustion zone 251 enter the second catalytic zone 214 . Within the second catalytic zone 214 steam methane reforming and water gas shift reactions occur. The product gas then leaves the second catalytic zone 214 and enters a process waste heat boiler 216 or other heat recovery (or heat exchange) device. The syngas product 217 may then be further processed as required.
[0077] Additional staging of hydrocarbon is possible as a portion of the preheated hydrocarbon 202 X can be staged to any of the burners. For illustrative purposes only, only two partial oxidation and two catalytic zones with oxidant and hydrocarbon staging are shown in FIG. 3 . However, any number of additional catalytic zones and partial oxidation zones may be added.
[0078] Also, the hydrocarbon feed 201 may be staged to different partial oxidation zones (as shown) or fed preferentially to only one zone. A horizontal configuration is shown, but a vertical upflow design may be operated with the catalyst monolith. A plurality of burners 210 may be provided within each partial oxidation zone.
[0079] Table 1 shows the typical process conditions for a conventional vertical packed bed autothermal reformer, such as that shown in FIG. 1 . A single burner within the conventional design limits the total firing. Thus, the maximum reported outlet temperature of a packed bed vertical autothermal reformer is approximately 1922° F. Higher effluent temperatures would require significantly higher temperatures in the POX zone 22 in FIG. 1 . Furthermore, even higher steam to carbon ratios would be needed to avoid soot formation. The staging of the combustion load within a vertical packed bed autothermal reformer is not practical because of the support arch zone 16 .
TABLE 1 Process Conditions For Conventional Autothermal Reformer Tin/Tout 900/1850° F. Steam/Carbon 0.6-3.0 Pressure 300-450 psig Oxygen/Carbon 0.5-75 H 2 /CO 2.0-4.0 Catalyst Ceramic w/9 wt % Nickel Burner Oxygen/Fuel
[0080] The present invention solves the problem of achieving higher effluent syngas temperatures by reducing the peak combustion load and dispersing/staging the load to different zones within the reactor. The use of a monolith catalyst facilities the staging used in the various embodiments of the present invention. The fixed structure of the monolith allows for either horizontal or upflow configurations. The horizontal configuration does not require any support arch, since the monolith is its own support. Thus, a series of POX zones and catalytic zones can be used. The multiple partial oxidation zones minimize the peak firing in any zone. Thus, the adiabatic flame temperature can be moderated by the choice of the amount of feed, oxidant, and any secondary feed to any POX zone. This permits the use of multiple burners (each less complex than a uni-burner) which operate at less severe conditions than the conventional uni-burner. Because the effective momentum is reduced in the first POX zone, a target brick system is not necessary and may be eliminated or replaced by a section of low or inactive monolith.
[0081] A comparison of temperature profiles within the catalyst bed for a conventional autothermal reformer (“current ATR process”) and one embodiment of a staged reformer (“two-stage ATR”) of the present invention is illustrated in FIG. 4 . As shown, the embodiment of the present invention achieves higher syngas exit temperatures while maintaining lower maximum internal temperatures in the reformer. This is achieved by the proper staging of both the oxidant and the fuel.
[0082] The multi-stage autothermal reformer designs for the various embodiments of the present invention allow integration with downstream heat recovery equipment within a common process unit and eliminate the need for a transfer line. For example, referring to the embodiment shown in FIG. 5 , the configuration of that embodiment permits a close coupling of the reformer reactor with downstream heat recovery equipment 216 , which may be any process equipment. For example, a process waste heat boiler or a convective heat exchanger could reduce the syngas temperature below the carbon formation region, while recovering heat from the syngas stream.
[0083] Both symmetric and asymmetric integration designs are possible. Symmetric designs with an equal number of reforming stages on each side of a heat recovery unit have particular importance for large-scale syngas generation.
[0084] FIG. 5 illustrates a symmetric integration design combining two two-stage autothermal reformers integrated with a heat recovery device 216 or heat exchanger. Another symmetric integration design is shown in FIG. 6 where a heat recovery device 216 or heat exchanger is between the first and second stages of a two-stage autothermal reformer.
[0085] Table 2 below compares the operating conditions for a conventional autothermal reformer (“single-bed ATR”) to the operating conditions for two embodiments (“SHARP-2 beds”) of the present invention. (“ATR” is an abbreviation for autothermal reformer, and “SHARP” is an abbreviation for staged horizontal autothermal reforming process.) The effluent temperature (Texit) for the conventional single-bed vertical autothermal reformer is 1922° F. Both embodiments of the present invention supply 40% of the hydrocarbon feed to the first POX zone with the balance supplied to the second POX zone. The first embodiment of the present invention maintains the same effluent temperature as the conventional unit, 1922° F., while in the second embodiment, the effluent temperature is increased to 2100° F. The oxidant staging is controlled to maintain a maximum effluent temperature of 1800° F. from the first catalytic zone.
[0086] An inherent advantage of the various embodiments of the present invention is that water formed in the first catalytic zone can be used to effectively increase the steam to carbon ratio in the second catalytic zone. For the same effluent temperature (ATR vs. SHARP embodiment 1), the adiabatic flame temperature in the SHARP embodiment 1 (3474 20 F.) is 92° F. lower than for the ATR (3566° F.). Also, less oxygen (˜20,000 lbs/h) and steam (˜100,000 lbs/h) are needed for the process of the SHARP embodiment 1 for the same syngas production as in the conventional single-bed ATR process. The lower overall steam requirement, but higher local steam to O2, permits less CO2 import to the process.
[0087] The second embodiment of the present invention (SHARP embodiment 2) increased the reactor effluent temperature to 2100° F., which increased the O2 requirement to approximately the same as that for the single-bed ATR case, about 400,000 lbs/h. The higher effluent temperature reduced the CO2 import requirement by about 2400 lbmol/h, or by 45%. The concomitant reduction of CO2 in the syngas greatly reduces the size of the CO2 separation equipment downstream.
TABLE 2 Comparison of Operating Conditions Single-bed ATR SHARP - 2 beds Feed split % 40/60 40/60 Texit Bed 1 1800 1800 Texit ATR F 1922 1922 2100 Feed lbmol/hr 19,493 19,283 19,396 Process Steam lb/hr 377,958 279,527 281,170 Oxygen lb/hr 400,830 380,633 403,257 S/C Preref. 0.6 0.6 0.6 S/C Bed 1 1.0 1.0 1.0 S/C Bed 2 1.283 1.256 O2/C Bed 1 0.64 0.594 0.588 O2/C Bed 2 0.609 0.665 Stm/O2 Bed 1 1.57 1.68 1.70 Stm/O2 Bed 2 2.11 1.89 Tad_in Bed 1 F 3566 3474 3496 Tad_in Bed 2 F 3436 3642 H2 to Burner 1 % (wet) 4.3 4.4 4.5 H2 to Burner 2 % (wet) 25.7 26.3 ATR Effluent lbmol/hr 86596 78939 78791 CO2 in effluent lbmol/hr 6660 5012 4288 CH4 slip % (dry) 0.33 0.51 0.12 CO2 import lbmol/hr 5342 4005 2935 CO2 rec. comp. kW 7511 5631 4127
[0088] Although illustrated and described herein with reference to certain specific embodiments, the present invention is nevertheless not intended to be limited to the details shown. Rather, various modifications may be made in the details within the scope and range of equivalents of the claims and without departing from the spirit of the invention.
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An apparatus and method for reforming a fuel include: first and second partial oxidation zones; and first and second catalytic zones containing first and second catalysts respectively. The first catalytic zone is in fluid communication with the first and second partial oxidation zones. The second catalytic zone is in fluid communication with the second partial oxidation zone. The first partial oxidation zone has at least one burner adapted to partially oxidate at least a portion of a first stage feed of the fuel with at least a portion of a first stream of an oxidant. The second partial oxidation zone has at least one other burner adapted to partially oxidate at least a portion of a second stage feed of the fuel or an other feed of an other fuel with at least a portion of a second stream of the oxidant or an other oxidant.
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FIELD OF THE INVENTION
The present invention relates to a novel process for living/controlled polymerization of vinyl monomers, particularly to use of a novel initiating system comprising an organic sulfur compound combined with an onium salt for living/controlled polymerization of vinyl monomers.
BACKGROUND OF THE INVENTION
Conventional chain polymerization of vinyl monomers usually consists of three main elemental reaction steps: initiation, propagation, and termination. Initiation stage involves creation of an active center from an initiator. Propagation involves growth of the polymer chain by sequential addition of monomer to the active center. Termination (including irreversible chain transfer) refers to termination of the growth of the polymer chain. Owing to the presence of termination and poorly controlled transfer reactions, conventional chain polymerization typically yields a poorly controlled polymer in terms of predicted polymer properties. Moreover, conventional chain polymerization processes mostly result in polymers with simple architectures such as linear homopolymer and linear random copolymer.
In 1950s, a so-called living polymerization was discovered by Szwarc (Szwarc, et al. J. Am. Chem. Soc. 78, 2656 (1956)). Living polymerization was characterized by the absence of any kinds of termination or side reactions which might break propagation reactions. The most important feature of living polymerization is that one may control the polymerization process to design the molecular structural parameters of the polymer. Additional polymerization systems where the termination reactions are, while still present, negligible compared to propagation reaction have also been disclosed. As structural control can generally still be well achieved with such processes, they are thus often termed “living” or controlled polymerization (Wang, Macromolecules, 28, 7901 (1995)). In living and “living” (or controlled) polymerization, as only initiation and propagation mainly contribute to the formation of polymer, molecular weight can be predetermined by means of the ratio of consumed monomer to the concentration of the initiator used. The ratio of weight average molecular weight to number average molecular weight, i.e., molecular weight distribution (Mw/Mn), may accordingly be as low as 1.0. Moreover, polymers with specifically desired structures and architectures can be purposely produced. In terms of topology, such structures and architectures may include: linear, star, comb, hyperbranched, dendritic, cyclic, network, and the like. In terms of sequence/composition distribution such structures and architectures may include: homopolymer, random copolymer, block copolymer, graft copolymer, gradient copolymer, tapered copolymer, periodic copolymer, alternating copolymer, and the like. In terms of functionalization, such structures and architectures may include: telechlics, macromonomer, labeled polymer, and the like.
A number of living/“living” polymerization processes have been developed. Examples of these polymerization processes include: anionic polymerization (Szwarc, J. Am. Chem. Soc. 78, 2656 (1956)), cationic polymerization (Sawamoto, Trends Polym. Sci. 1, 111 (1993)), ring opening methathesis polymerization (Gillium and Grubbs, J. Am. Chem. Soc. 108, 733 (1986)), nitroxides-mediated stable radical polymerization (Solomon, U.S. Pat. No. 4,581,429 (1986), Georges, Macromolecules, 26, 2987 (1993)), Cobalt complexes-mediated radical polymerization (Wayland, J. Am. Chem. Soc. 116, 7943 (1994)), and transition metal catalyzed atom transfer radical polymerization (Wang, U.S. Pat. No. 5,763,548 (1998)).
Living/“living” polymerization processes have been successfully used to produce numerous specialty polymeric materials which have been found to be very useful in many applications. One example is the commercialization of styrenic thermoplastic elastomers such as styrene-b-butadiene-b-styrene triblock copolymers (SBS) by Shell chemicals and others. SBS is made by sequential anionic living polymerization of styrene and butadiene. However, except for living anionic polymerization of non-polar monomers such as styrene and dienes using alkyl lithium as an initiator, almost all of other living/“living” systems mentioned-above currently showed little promise for wide industrial commercialization, mainly due to high cost to industrially implement these processes. Thus, searching for practical living/“living” polymerization processes is a major challenge in the field of polymer chemistry and materials.
Organic halide compounds have been used as initiator in several “living” polymerization systems. Sawamoto et al used a series of mixtures of alkyl halide and Lewis acid as initiating system in “living” cationic polymerization of vinyl ether, isobutylene, and styrene (Sawamoto, Trends Polym. Sci. 1, 111 (1993)). However, these cationic polymerizations required very restricted conditions such as moisture and impurities free reaction systems. Ganyor et al disclosed that combination of certain alkyl iodide with conventional radical initiator such as AIBN induced a “living” polymerization of styrene, methyl methacrylate, and methyl acrylate (Gaynor et al. Macromolecules 28, 8051 (1995)). The discovery of transition metal catalyzed atom transfer radical polymerization (ATRP) by Wang et al represents a very important step towards practical “living” polymerization (Wang, J. Am. Chem. Soc., 117, 5614 (1995), and U.S. Pat. No. 5,763,548). Using alkyl halide as an initiator and transition metal species as a catalyst, ATRP not only works well with a very broad variety of important vinyl monomers but also provides much easier pathway towards a variety of polymers with various structure and architectures. However, the use of heavy transition metal salts or complexes requires multi-step purification of the resultant polymers. Moreover, heavy transition metal salts or complexes are often toxic and not environmentally friendly. These drawbacks limit the wide implementation of current version ATRP process in industrial production.
An initiating system comprising an alkyl halide and an onium salt has been also found to be effective in promoting “living” polymerization. Reetz (Reetz et al. Macromol. Rapid Commun. 17, 383 (1996)) disclosed that while neither diethyl or dimethyl iodomethylmalonate nor tetra-n-butylammonium iodide alone initiated the polymerization of methyl methacrylate (MMA), a “living” polymerization of MMA was achieved by using diethyl or dimethyl iodomethylmalonate/tetra-n-butylammonium iodide (1/1) as an initiating system in polar solvents. The controlled poly (methyl methacrylate) was obtained in the number-average molecular weight range of 2000 to 8000, with molecular weight distribution being fairly narrow (ratio of weight- to number-average molecular weights Mw/Mn 1.2-1.3). Although the underlying mechanism is still unclear, the onium salt used acts as a catalyst in this homogenous polymerization system. In comparison with other “living” systems, the alkyl iodide/ammonium salt combined catalyst system disclosed by Reetz represents a simpler and cleaner one towards “living” polymerization. Due to the instability of iodide containing organic compounds, however, such process may not be commercially feasible, and it has been found that more stable alkyl chlorides or bromides alone are not reactive enough to react with onium salt to generate initiating species in chain polymerization.
Phase-transfer catalysis, PTC, was first coined by Starks in 1971 (J. Am. Chem. Soc., 93, 195 (1971)). It has been widely and practically used in various preparative organic, organometallic and polymer chemistry. PTC is a technique for conducting reactions between two or more reagents in one or two or more phases, when reaction is inhibited because the reactants cannot easily come together and one reagent is not reactive enough towards another one. A “phase-transfer agent” is added to transfer one of the reagents to a location where it can conveniently and rapidly react with another reagent. Two types of phase transfer agents are found efficient: quaternary salts and certain chelating reagents such as crown ethers, cryptands, poly(ethylene glycol) and their derivatives.
Traditional fields of polymer chemistry like radical, anionic and condensation polymerizations, as well as chemical modification of polymers, have substantially benefited from the use of phase transfer catalysis (Starks, Phase-Transfer Catalysis, ACS Symposium Series 326, 1987). Much work has been reported, e.g., on the use of phase transfer catalysis in condensation polymerization for the synthesis of polyester, polysulfonates, polyphosphonates, polysulfones, polythioesters, polyamides, polycarbonate, etc (see: Percec, in Phase-Transfer, Chapter 9, Starks Ed., ACS Symposium Series, Vol. 326 (1987)). It was often noticed that, in the absence of catalyst, only low molecular weight condensation polymer was produced even after long periods of time, whereas with the presence of the onium catalyst, high molecular weight of polymer was achieved after relatively short periods of time.
Phase transfer catalysis has been also used in chain polymerization. Rasmussen and co-workers have disclosed that many free radical polymerizations of acrylic monomers can be conducted in two-phase systems using potassium persulfate and either crown ethers or quaternary ammonium salts as initiators (Rasmussen et al. in, Phase-Transfer Catalysis, ACS Symposium Series 326, Starks Ed., p 116, 1987). When transferred to the organic phase, persulfate performs far more efficiently as an initiator than conventional initiators such as azobisisobutyronitrile or benzoyl peroxide. Photopolymerization of methyl methacrylate with quaternized ammonium salt-potassium thiocyanate-CCl 4 was also reported (Shimada, S. Polym. J. 30, 152 (1998)). However, all disclosed polymerization processes under phase transfer conditions were not living or “living”. The monomer conversion to polymer was often very low; molecular weight can not be controlled; and molecular weight distribution is very broad (Mw/Mn often more than 2).
Use of organic sulfur compounds is also known in living/controlled polymerization. Otsu et al. “Features of Living Radical polymerization of Vinyl Monomers in Homogeneous System Using N,N-Diethyldithiocarbamate Derivatives as Photoiniferters” Eur. Polym. J. 31, 67 (1995), e.g., reports that radical photopolymerization of vinyl monomers with some sulfur compounds containing an N,N-diethyldithiocarbamyl group as photoiniferters proceeds via a living radical polymerization mechanism. Rizzardo et al. “Synthesis of Defined Polymers by Reversible Addition-Fragmentation Chain Transfer: The RAFT Process”, ACS, pp. 278-96 (2000), discloses a radical polymerization process using a suitable thiocarbonylthio compound as an initiator and a typical radical initiator as a catalyst. The selection of particular sulfur compounds and/or reaction conditions, however, are described as being critical for such prior processes to function effectively.
Wang U.S. Pat. No. 6,306,995 discloses a process for polymerization of vinyl monomers comprising (a) forming an initiator comprising an organic iodide compound by reacting an initiator precursor comprising an organic bromide or chloride compound with an inorganic iodide salt under phase transfer catalysis in the presence of a phase transfer agent, and (b) polymerizing vinyl monomers in the presence of the formed initiator and a polymerization catalyst comprising an onium salt. Wang U.S. Pat. No. 6,310,165 discloses another process for polymerization of vinyl monomers comprising (a) forming an onium salt complex comprising a transition metal component by reacting an onium salt with a transition metal species, and (b) polymerizing vinyl monomers in the presence of the formed transition metal containing onium salt and an organic halide initiator compound. There is no disclosure, however, in such patents of the use of initiating systems employing organic sulfur compounds in combination with onium salts.
It would be desirable to provide a novel method for living polymerization of vinyl monomers which provides a high level of macromolecular control over the polymerization process and which leads to uniform and more controllable polymeric products. It would be especially desirable to provide such a living polymerization process with existing facility, and which enables the use of a wide variety of readily available starting materials and catalysts.
SUMMARY OF THE INVENTION
In accordance with one embodiment of the invention, a process for polymerization of vinyl monomers is described comprising polymerizing vinyl monomers in the presence of an initiating system comprising (i) an organic sulfur compound and (ii) an onium salt catalyst.
The present invention provides a novel method for living polymerization of vinyl monomers, which provides a high level of macromolecular control over the polymerization process and which leads to uniform and controllable polymeric products. Oil soluble monomers may be polymerized in organic solvent or water-organic two phase solvent systems, while water soluble monomers may be polymerized in water or water-organic two phase solvent systems.
DETAILED DESCRIPTION OF THE INVENTION
According to the present invention, a novel polymerization process is described for conducting polymerization of monomers, particularly “living” polymerization of alkenes, wherein a novel initiating system is provided for producing oligomers and polymers with controlled structure. In the context of the present invention, the term “living” refers to the ability to produce a product having one or more properties which are reasonably close to their predicted value. The polymerization is said to be “living” if the resulting number average molecular weight is close to the predicted molecular weight based on the ratio of the concentration of the consumed monomer to the one of the initiator; e.g., within an order of magnitude, preferably within a factor of five, more preferably within a factor of 3, and most preferably within a factor of two, and to produce a product having narrow molecular weight distribution as defined by the ratio of weight average molecular weight to number molecular weight (MWD); e.g., less than 10, preferably less than 2, more preferably less than 1.5, most preferably less than 1.3. Moreover, compared with conventional polymerization, the conversion of the monomer in “living” polymerization is higher, e.g., higher than 10%, preferably higher than 30%, more preferably higher than 50%, most preferably higher than 80%.
In the present invention, the polymerization initiating system comprises (i) an organic sulfur compound and (ii) an onium salt catalyst. The organic sulfur compound employed in the initiating system is not required to be able to induce “living” polymerization as defined herein by itself, or in many instances even polymerization. However, the combination of organic sulfur compound and onium salt leads to a novel initiating system which enables polymerization to proceed in a “living” way. Such combination thus enables use of a wider variety of organic sulfur compounds as initiators than previously reported for living polymerization processes.
In a particular embodiment of the invention, the organic sulfur compound employed in the initiating system in the process of the invention may be selected from any organic sulfur compound with the following formulae I, II,III or IV:
R 1 —S—R 2 (I)
R 1 —S—S—R 2 (II)
R 1 —C(═S)—S—R 2 (III)
R 1 —C(═S)—S—S—C(═S)—R 2 (IV)
where R 1 and R 2 are independently selected from the following group: substituted or non-substituted alkyl, substituted or non-substituted aryl, substituted or non-substituted cycloalkyl, hetero-atom containing substituted or non-substituted alkyl, hetero-atom containing substituted or non-substituted aryl, hetero-atom containing substituted or non-substituted cycloalkyl, NR 3 R 4 , SR 5 , OR 6 , C(O)R 7 , or C(O)OR 8 , where R 3 , R 4 , R 5 , R 6 , R 7 and R 8 are substituted or non-substituted alkyl, substituted or non-substituted aryl, substituted or non-substituted cycloalkyl, hetero-atom containing substituted or non-substituted alkyl, hetero-atom containing substituted or non-substituted aryl, or hetero-atom containing substituted or non-substituted cycloalkyl.
Specific examples of organic sulfur compounds which may be employed in the initiating system in the process of the invention include but are not limited to:
(C 2 H 5 ) 2 NC(═S)—S—S—C(═S)N(C 2 H 5 ) 2 “tetraethylthiuram disulfide”,
C 6 H 5 —S—C(O)CH 3 “s-phenyl thioacetate”,
(CH 3 ) 2 C(—S—Ph)COOC 2 H 5 ,
(CH 3 ) 2 C(—S—C(═S)OC 2 H 5 )COOC 2 H 5 ,
(CH 3 ) 2 C(—S—C(═S)N(C 2 H 5 ) 2 )COOC 2 H 5 .
Various onium salts can be used in the present invention, such as any of the onium salts described in Phase - Transfer Catalysis, Fundamentals, Applications, and Industrial Perspectives (Starks, et al. Chapman & Hall, New York, 1994). Such onium salts can be selected from the group with the formula W + X′ − where W + is a salt cationic onium ion group containing N + , P + , S + , As + , or Sb + element, and X′ − is a counter-anion. Onium salt counter-anion X′ − and can be selected, e.g., from the group consisting of Cl − , Br − , I − , NO 3 − , NO 2 − , ClO 3 − , BrO 3 − , IO 3 − , ClO 4 − , MnO 4 − , ReO 4 − , IO 4 − , CrO 4 −2 , nolybdate, tungstate, vanadate, borate, SO 4 −2 , S −2 , S 2 O 3 −2 , arsentite, arsenate, selenite, tellurite, (CO 2 − ) 2 , CO 3 −2 , F − , CH 3 CO 2 − , C 6 H 5 CO 2 − , SCN − , MeSO 3 − , N 3 − , Br 3 − , OH − , CN − , picrate, nitrate, acetate, sulfate.
Preferred onium salts include but are not limited to: Me 4 N + Br − , Pr 4 N + Br − , Bu 4 N + Br − , Bu 4 P + Br − , Bu 4 N + Cl − , Bu 4 N + F − , Bu 4 N + I − , Bu 4 P + Cl − , (C 8 H 17 ) 3 NMe + Cl − , (C 8 H 17 ) 3 PEt + Br − , C 6 H 13 NEt 3 + Br − , C 7 H 17 NEt 3 + Br − , C 10 H 20 NEt 3 + Br − , C 12 H 25 NEt 3 + Br − , C 16 H 33 NEt 3 + Br − , C 6 H 13 PEt 3 + Br − , C 6 H 5 CH 2 NEt 3 + Br − , C 16 H 33 PMe 3 + Br − , ,(C 6 H 5 ) 4 P + Br − , (C 6 H 5 ) 4 As + Cl − , (C 6 H 5 ) 4 As + Br − , (C 6 H 5 ) 3 PMe + Br − , (HOCH 2 CH 2 ) 3 NBu + Br, Bu 4 N + OH − , Bu 4 N + (ClCrO 3 ) − , Bu 4 N + CN − , Bu 4 N + BH 3 CN − , Bu 4 N + (H 2 PO 4 ) − , Bu 4 N + (H 2 PO 2 ) − , Bu 4 N + ½(PtCl 6 ) − , Bu 4 N + PF 6 − , Bu 4 N + HSO 4 − , Bu 4 N + [CH 3 CH(OH)CO 2 ], Bu 4 N + NO 3 − , Bu 4 N + IO 4 − , Bu 4 N + ReO 4 − , Bu 4 N + BF 4 − , Bu 4 N + [B(C 6 H 5 ) 4 ] − , Bu 4 N + [CF 3 SO 3 ] − ,
Additional onium salts which may be used include other so-called ionic liquids as described in Chemical Review (Welton, 99, 2071 (1999)).
In addition to “ordinary” onium salts as described above, onium salts employed in the process of the invention may comprise onium salt complexes of the type described in U.S. Pat. No. 6,310,165. Such complexes can be selected from the group with the formula: [MX′Y] − W + , which results from reaction between an onium salt of the formula W + X′ − such as described above with a transition metal species of the formula MY, where M is a transition metal atom with a formal charge of from 0-7, and Y is one or more counter-anion or coordinative ligand. The transition metal M which may be selected, e.g., from the group consisting of Ag, Au, Cu, Co, Cr, Fe, Hg, Ir, Mo, Nb, Ni, Os, Pd, Pt, Re, Rh, Ru, Tb, Ta, V, W, and Zn. Counter-anions which may be used for Y may be selected, e.g., from those set forth for X′ − above, and representative coordinative ligands may be, e.g., (CO), cyclopentadienyl, and cyclooctadiene.
The onium salt can be used in a total amount of 0.01 to 100 moles, preferably 0.05 to 10 moles, more preferably 0.1 to 5 moles, most preferably 0.2 to 2 moles per mole of the organic sulfur compound.
Organic sulfur compounds employed in the process of the invention may be preformed, or may be generated in situ in a polymerization reaction vessel by addition of an organic halide compound and a sulfur salt compound in the presence of a phase transfer catalyst. Any organic halide, R—X, may be employed where R is any organic moiety and X is Cl, Br or I. Examples of organic halide compounds include but are not limited to ethyl 2-bromoisobutyrate, ethyl 2-iodoisobutyrate, diethyl 2-bromo-2-methylmalonate, diethyl 2-iodo-2-methylmalonate, 2-chloropropionitrile, 2-bromopropionitrile, 2-iodopropionitrile, 2-bromo-2-methylpropionic acid, 2-bromoisobutyrophone, ethyl trichloroacetate, 2-bromoisobutyryl bromide, 2-chloroisobutyryl chloride, α-bromo-α-methyl-γ-butyrolactone, p-toluenesulfonyl chloride and its substituted derivatives, 1,3-benzenedisulfonyl chloride, carbon tetrachloride, carbon tetrabromide, chloroacetonitrile, iodoacetonitrile, tribromoethanol, tribromoacetyl chloride, trichloroacetyl chloride, tribromoacetyl bromide, chloroform, 1-phenyl ethylchloride, 1-phenyl ethylbromide, 2-chloropropionic acid, 2-bromoisobutyric acid, 4-vinyl benzene sulfonyl chloride, vinyl benzenechloride, 2-chloroisobutyrophenone, and 2-bromoisobutyrophenone. Any sulfur salt compound can be selected which will react with R—X to form an organic sulfur compound under phase transfer catalysis (PTC). Examples of sulfur salt compounds which may be employed include but are not limited to Na[SC(═S)N(C 2 H 5 ) 2 ], K[SC(═S)OC 2 H 5 ], K[S—C 6 H 5 ].
Phase transfer catalysts which may be used for the in situ formation of an organic sulfur compound in the initiating system in accordance with one embodiment of the process of the invention in the present invention are likewise well-known. They can be selected, e.g., from any phase transfer catalysts set forth in Starks, et al. Phase - Transfer Catalysis, Fundamentals, Applications, and Industrial Perspectives , Chapman & Hall, New York, 1994, or other resources. In general, phase transfer catalysts which may be used include any onium salts as described above and chelating agents. In a preferred embodiment of the invention, when the organic sulfur compound is to be formed in situ, the same onium salt compound employed in the initiating system may be used as the phase transfer catalyst.
Any chelating agents which can facilitate the reaction between a sulfur salt compound and an organic compound R—X can alternatively be used in the present invention as phase transfer agent. Examples of these chelating agents include but are not limited to polyethylene glycol and derivatives such as HO(CH 2 CH 2 O) n H (n=2-600), RO(CH 2 CH 2 O)H where R=C 1 to C 13 alkyl groups, N(CH 2 CH 2 OCH 2 CH 2 OCH 3 ) 3 , N(CH 2 CH 2 OCH 2 CH 2 OH) 3 , crown ethers and cryptands such as 18-crown-5, 15-crown-5, dibenzo-18-crown-6, dicyclohexano-18-crown-6, Kryptand 211, Kryptand 222, Kryptand 221.
The phase transfer reaction can be carried out before adding monomer and polymerization catalyst or during the course of the polymerization. Moreover, the phase transfer reaction may be carried out in one, or more than one phases. The sulfur salt compound in such embodiment can be used in a total amount of 0.01 to 100 moles, preferably 0.1 to 10 moles, more preferably 0.2 to 5 moles, most preferably 0.4 to 3 moles per mole of the R—X initiator precursor. The phase transfer catalyst can be used in a total amount of 0.01 to 100 moles, preferably 0.1 to 10 moles, more preferably 0.2 to 5 moles, most preferably 0.4 to 3 moles per mole of the R—X initiator precursor.
In the present invention, polymers with various specifically desired structures and architectures can be purposely produced. In terms of topology, such structures and architectures may include: linear, star, comb, hyperbranched, dendritic, cyclic, network, and the like. In terms of sequence/composition distribution such structures and architectures may include: homopolymer, random copolymer, block copolymer, graft copolymer, gradient copolymer, tapered copolymer, periodic copolymer, alternating copolymer, and the like.
In the present invention, any vinyl monomers can be polymerized and/or copolymerized in the presence of the above-mentioned initiating system. Examples of the monomers include but not limited to: carboxyl group-containing unsaturated monomers such as acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, and the like (preferably methacrylic acid), C 2-8 hydroxyl alkyl esters of (meth)acrylic acid (preferably methacrylic acid) such as 2-hydroxylethyl (meth)acrylate, 2-hydroxylpropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate and the like, monomesters between a polyether polyol (e.g., polyethylene glycol, polypropylene glycol or polybutylene glycol) and an unsaturated carboxylic acid (preferably methacrylic acid); monoethers between a polyether polyol (e.g., polyethylene glycol, polypropylene glycol or polybutylene glycol) and a hydroxyl group-containing unsaturated monomers (e.g., 2-hydroxyl methacrylate); adducts between an unsaturated carboxylic acid and a monoepoxy compound; adducts between glycidyl (meth)acrylates (preferably methacrylate) and a monobasic acid (e.g., acetic acid, propionic acid, p-t-butylbenzonic acid or a fatty acid); monoesters or diesters between an acid anhydride group-containing unsaturated compounds (e.g., maleic anhydride or iraconic anhydride) and a glycol (e.g. ethylene glycol, 1,6-hexanediol or neopentyl glycol); chlorine-, bromine-, fluorine-, and hydroxyl group containing monomers such as 3-chloro-2-hydroxylpropyl (meth)acrylate (preferably methacrylate) and the like; C 1-24 alkyl esters or cycloalkyl esters of (meth)acrylic acid (preferably methacrylic acid), such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, n-, sec-, or t-butyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, octylmethacrylate, decyl methacrylate, lauryl methacrylate, stearyl methacrylate, cyclohexyl methacrylate and the like, C 2-18 alkoxyalkyl esters of (meth)acrylic acid (preferably methacrylic acid), such as methoxybutyl methacrylate, methoxyethyl methacrylate, ethoxyethyl methacrylate, ethoxybutyl methacrylate and the like; olefines or diene compounds such as ethylene, propylene, butylene, isobutene, isoprene, chloropropene, fluorine containing olefins, vinyl chloride, and the like; ring-containing unsaturated monomers such as styrene and o-,m-,p-substitution products thereof such as N,N-dimethylaminostyrene, aminostyrene, hydroxystyrene, t-butylstyrene, carboxystyrene and the like, a-methyl styrene, phenyl (meth)acryltes, nitro-containing alkyl (meth)acrylates such as N,N-dimethyl-aminoethyl methacrylate, N-t-butylaminoethyl methacrylate; 2-(dimethylamino)ethyl methacrylate, methyl chloride quaternized salt, and the like; polymerizable amides such as (meth)acrylamide, N-methyl(meth)acrylamide, 2-acryloamido-2-methyl-1-propanesulfonic acid, and the like; nitrogen-containing monomers such as 2-, 4-vinyl pyridines, 1-vinyl-2-pyrrolidone, (meth)acrylonitrile, and the like; glycidyl group-containing vinyl monomers such as glycidyl (meth)acrylates and the like, vinyl ethers, vinyl acetate, and cyclic monomers such as methyl 1,1-bicyclobutanecarboxylate. These monomers can be used singly or as admixture of two or more than two.
Vinyl terminated macromonomers, such as any of those which are defined in “Chemistry and Industry of Macromonomers” (Yamashita, Huthig & Wepf, New York 1993), can also be used in the present invention. The preferable macromonomers are those terminated with methacrylate groups. Examples of such macromonomers include, but are not limited to, poly(ethylene oxide) methacrylate, poly(styrene) methacrylate, poly(siloxane) methacrylate, poly((meth)acrylic acid) methacrylate, and poly(alkyloxazoline) methacrylate.
A polymerizable quaternized monomer or monomers (e.g., 2-(dimethylamino)ethyl methacrylate , methyl chloride quaternized salt, and the like) may also be employed in the process of the present invention, and it may be unnecessary to use additional “ordinary” onium salt in combination with the organic sulfur compound. In such case, “living” polymerization of quaternized monomer can be considered as a monomer self-catalyzed polymerization.
The above polymerizable monomer or monomers can be used in a total amount of generally from 3-20,000 moles, preferably 5-2,000 moles, more preferably 10-1,000 moles per mole of the organic sulfur compound initiator. The molecular weight distribution of resultant polymer (defined by the ratio of weight average molecular weight to number average molecular weight) obtained from processes of the present invention is generally from 1.01 to 30, mostly from 1.05 to 3.0, and more preferably less than 2.0.
Various organic or inorganic functional groups can be introduced to the ends of formed polymer or copolymer. By definition, a functional group is a moiety attached to a molecule that performs a function in terms of the reactivity and/or the physical properties of the molecule bearing it. Example of functional groups include but not limited to: halogens (e.g., Cl, Br, I), hydroxyl (—OH) groups such as —CH 2 OH, —C(CH 3 ) 2 OH, —CH(OH)CH 3 , phenol and the like, thiol (—SH) groups, aldehyde (—CHO) and ketone (>C═O) groups, amine (—NH 2 ) groups, carboxylic acid and salt (—COOM) (M is H, alkali metal or ammonium), sulfonic acid and salt (—SO 3 M) (M is H, alkali metal or ammonium), amide (—CONH 2 ), crown and kryptand, substituted amine (—NR 2 ) (R is H or C 1-18 alkyl), —C═CR′, —CH═CHR′(R′ is H or alkyl or aryl or alkaryl or aralkyl or combinations thereof), —COX (X is halogen), —CH 2 N(SiR′ 3 ) 2 , —Si(OR′) 3 , —CN, —CH 2 NHCHO, —B(OR) 2 , —SO 2 Cl, —N 3 , —MgX. Functionalized polymer and copolymers including macromonomer prepared in accordance with the invention may be obtained by two ways: (a) one-pot synthesis using functional initiator; (b) transformation of living or preformed polymer to a desirable functional group by known organic reactions.
Various polymerization technologies can be used to make the polymer, which include but not limited to: bulk polymerization, solution polymerization, emulsion polymerization, suspension polymerization, dispersion polymerization, precipitation polymerization, template polymerization, micro-emulsion polymerization. Various solvents can be used in the polymerization. Examples of the solvents are but not limited to: water, aliphatic solvent, aromatic solvent, hetero-atom containing solvent, supercritical solvent (such as CO 2 ), and the like. The inventive process can typically be conducted between −80° C. and 280° C., preferably between 0° C. and 180° C., more preferably between 20° C. and 150° C., most preferably between 20° C. and 130° C. The inventive process can be conducted under a pressure from 0.1 to 50,000 kPa, preferably from 1 to 1,000 kPa. The addition order of various ingredients in according with the process of the invention can vary and generally do not affect the outcome of the “living” polymerization. Depending the expected molecular weight and other factors, polymerization time may vary from 10 seconds to 100 hours, preferably from 1 minute to 48 hrs, more preferably from 10 minutes to 24 hrs, most preferably from 30 minutes to 18 hrs.
The final polymer can be used as it is or is further purified, isolated, and stored. Purification and isolation may involve removing residual monomer, solvent, and catalyst. The purification and isolation process may vary. Examples of isolation of polymers include but not limited to precipitation, extraction, filtration, and the like. Final polymer product can also be used without further isolation such as in the form of the latex or emulsion.
Polymers prepared with the inventive process may be useful in a wide variety of applications. The examples of these applications are but not limited to: adhesives, dispersants, surfactants, emulsifiers, elastomers, coating, painting, thermoplastic elastomers, diagnostic and supporters, engineering resins, ink components, lubricants, polymer blend components, paper additives, biomaterials, water treatment additives, cosmetics components, antistatic agents, food and beverage packaging materials, release compounding agents in pharmaceuticals applications.
EXAMPLES
Example 1
An organic sulfur compound initiator, (CH 3 ) 2 C(SC(═S)N(C 2 H 5 ) 2 )COOC 2 H 5 , was synthesized by reacting 0.036 mol of ethyl 2-bromoisobutyrate with 0.046 mol of sodium N,N,-diethyldithiocarbamate in 60 ml ethanol at room temperature. The initiator was stored as a 65 wt % solution in benzene.
The following agents were weighted into a three necks round flask equipped with a condenser and magnetic stirring bar under ambient atmosphere: 5 grams of methyl methacrylate, 5 grams of DMPU, 0.13 grams of (CH 3 ) 2 C(SC(═S)N(C 2 H 5 ) 2 )COOC 2 H 5 (0.00049 mol), and 0.16 grams of Bu 4 NBr (0.0005 mol). After purging the solution with inert nitrogen gas for 30 minutes, the flask was covered and placed in a pre-heated oil bath at 80° C. After 16 hrs, an aliquot of solution was picked out and dissolved in CDCl 3 to determine the conversion. The conversion is 96%. Polymer was then isolated by precipitating from methanol. The polymer was characterized by means of SEC with number average molecular weight (Mn) and molecular weight distribution Mw/Mn being 43,300 and 1.8, respectively.
Example 2
The following agents were weighted into a three-neck round flask equipped with a condenser and magnetic stirring bar under ambient atmosphere: 5 grams of methyl methacrylate, 5 ml of 1,3-dimethyltetrahydro-2(1H)pyrimidone (DMPU), 0.15 grams of tetraethylthiuram disulfide (TETD) (0.0005 mol), 0.3 grams of Bu 4 NBr (0.001 mol). After purging the solution with inert nitrogen gas for 15 minutes, the flask was covered and placed in a pre-heated oil bath at 70° C. After 44 hrs, the polymer was isolated by precipitating from methanol. Convention based on 1 H NMR in CDCl 3 : 44%. The polymer was characterized by means of SEC with number average molecular weight (Mn) and molecular weight distribution Mw/Mn using polystyrene as calibration standard: Mn: 17600, and Mw/Mn: 1.23. The calculated Mn based on TETD: 4400.
Example 3
The experiment is similar to the one in example 2, except that 0.3 grams of TETD was used and polymerization was run for 90 hrs. The monomer conversion is 65%. The number average molecular weight (Mn) and molecular weight distribution Mw/Mn are 15,900 and 1.3, respectively.
Example 4
The following agents were weighted into a three necks round flask equipped with a condenser and magnetic stirring bar under ambient atmosphere: 5 grams of methyl methacrylate, 3 grams of anisol, 0.152 grams of s-phenyl thioacetate (0.001 mol), 0.32 grams of Bu 4 NBr (0.001 mol). After purging the solution with inert nitrogen gas for 30 minutes, the flask was covered and placed in a pre-heated oil bath at 80° C. After 17 hrs, the polymerization was stopped by lowering down to room temperature. Polymer was then isolated by precipitating from methanol. Convention (1H NMR): 16%. The polymer was characterized by means of SEC with number average molecular weight (Mn) and molecular weight distribution Mw/Mn being 381,000 and 1.60, respectively. The calculated Mn is 1000.
Example 5
The following agents were weighted into a three necks round flask equipped with a condenser and magnetic stirring bar under ambient atmosphere: 10 grams of styrene, 10 grams of DMPU, 0.2 grams of (CH 3 ) 2 C(SC(═S)N(C 2 H 5 ) 2 )COOC 2 H 5 (0.00075 mol), and 0.16 grams of Bu 4 NBr (0.0005 mol). After purging the solution with inert nitrogen gas for 30 minutes, the flask was covered and placed in a pre-heated oil bath at 80° C. After 5 hrs, an aliquot of solution was picked out and dissolved in CDCl 3 to determine the conversion. The conversion is 18%. Polymer was then isolated by precipitating from methanol. The polymer was characterized by means of SEC with number average molecular weight (Mn) and molecular weight distribution Mw/Mn being 25,400 and 2.7, respectively.
Comparative Example 1
Example 1 was repeated, except without using the organic sulfur compound initiator, (CH 3 ) 2 C(SC(═S)N(C 2 H 5 ) 2 )COOC 2 H 5 . No polymer was obtained.
Comparative Example 2
Example 1 was repeated, except without using the onium salt Bu 4 NBr. No polymer was obtained.
The invention has been described in detail with particular reference to preferred embodiments thereof, but it is to be understood that variations and modifications can be effected within the spirit and scope of the invention.
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A process for polymerization of vinyl monomers is described comprising polymerizing vinyl monomers in the presence of of an initiating system comprising (i) an organic sulfur compound and (ii) an onium salt catalyst. The present invention provides a novel method for living polymerization of vinyl monomers, which provides a high level of macromolecular control over the polymerization process and which leads to uniform and controllable polymeric products.
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RELATED APPLICATION
[0001] This application claims priority to co-pending, prior-filed U.S. Provisional Patent Application No. 62/279,307, filed Jan. 15, 2016, the entire contents of which are incorporated by reference.
FIELD
[0002] This invention generally relates to a coupling for removable axial locking of a hub on a rotating power transmission shaft.
SUMMARY
[0003] In one independent aspect, an insert for a motion-transmitting mechanism may be provided. The motion-transmitting mechanism may include a member defining a bore with a bore surface, and a shaft. The insert may generally include an insert body receivable in the bore, the insert body having an outer surface at least partially engageable in a driving relationship with the bore surface, the insert body defining an insert bore operable to receive the shaft in a driving relationship, torque transmission between the shaft and the motion-transmitting member through the insert body causing a portion of the insert body to compress toward the shaft.
[0004] In another independent aspect, a motion-transmitting mechanism may generally include a motion-transmitting member defining a bore with a bore surface; a shaft; and an insert including an insert body receivable in the bore, the insert body having an outer surface and defining an insert bore operable to receive the shaft, engagement between the bore surface and the outer surface providing torque transmission between the insert and the motion-transmitting member and causing a portion of the insert body to compress toward the shaft.
[0005] In yet another independent aspect, a method of operating a motion-transmitting mechanism may be provided. The motion-transmitting mechanism may include a motion-transmitting member defining a bore with a bore surface, a shaft, and an insert, the insert having an insert body received in the bore, the insert body having an outer surface and defining an insert bore for receiving the shaft. The method may generally include transmitting torque between the shaft and the motion-transmitting member, transmitting including engaging the bore surface and the outer surface to transmit torque between the insert and the motion-transmitting member; and by torque transmitted between the insert and the motion-transmitting member, causing a portion of the insert body to compress toward the shaft.
[0006] In a further independent aspect, an insert for a yoke assembly may be provided. The assembly may include a yoke, and a hub connected to the yoke, the hub defining a bore with a bore surface. The insert may generally include an insert body receivable in the bore, the insert body having an outer surface at least partially engageable in a driving relationship with the bore surface, the insert body defining an insert bore operable to receive a shaft in a driving relationship, torque transmission between the shaft and the motion-transmitting member through the insert body causing a portion of the insert body to compress toward the shaft.
[0007] In another independent aspect, a yoke assembly may generally include a yoke; a hub connected to the yoke, the hub defining a bore with a bore surface; and an insert including an insert body receivable in the bore, the insert body having an outer surface at least partially engageable in a driving relationship with the bore surface, the insert body defining an insert bore operable to receive a shaft in a driving relationship, torque transmission between the shaft and the motion-transmitting member through the insert body causing a portion of the insert body to compress toward the shaft.
[0008] In a yet another independent aspect, a method of operating a yoke assembly may be provided. The assembly may include a yoke, a hub connected to the yoke, the hub defining a bore with a bore surface, and an insert including an insert body received in the bore, the insert body having an outer surface and defining an insert bore for receiving a shaft. The method may generally include transmitting torque between the shaft and the hub, transmitting including engaging the bore surface and the outer surface to transmit torque between the insert and the hub; and, by torque transmitted between the insert and the hub, causing a portion of the insert body to compress toward the shaft.
[0009] In a further independent aspect, a method of manufacturing an insert for a motion-transmitting mechanism may be provided. The motion-transmitting mechanism may include a motion-transmitting member defining a bore with a bore surface, and a shaft. The method may generally include providing bar stock having a polygonal outer surface, when the insert is formed, the outer surface being at least partially engageable in a driving relationship in the bore; cutting the bar stock to a length for the insert; forming an insert bore in the insert for receiving the shaft in a driving relationship, forming including providing a side wall having adjacent wall sections; and forming a slot in at least one wall section to accommodate compression of the insert, in operation, torque transmission between the shaft and the motion-transmitting member through the insert causing a portion of the insert to compress toward the shaft.
[0010] Other independent features and independent aspects of the invention will become apparent by consideration of the following detailed description, claims and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a front perspective view of a collet locking yoke.
[0012] FIG. 2 is another front perspective view of the yoke of FIG. 1 with the insert retaining ring removed.
[0013] FIG. 3 is a front perspective view of the yoke of FIG. 1 with the insert removed.
[0014] FIG. 4 is a rear perspective view of the yoke of FIG. 1 .
[0015] FIG. 5 is an exploded view of the yoke of FIG. 1 .
[0016] FIG. 6 is a partially exploded view of the yoke of FIG. 1 .
[0017] FIG. 7 is a front perspective view of the yoke of FIG. 1 with the insert and the retaining ring removed.
[0018] FIG. 8 is a front view of the yoke of FIG. 1 .
[0019] FIG. 9 is a front view of the yoke of FIG. 1 with the retaining ring removed.
[0020] FIG. 10 is a front view of the yoke of FIG. 1 with the insert removed.
[0021] FIG. 11 is a rear view of the yoke of FIG. 1 .
[0022] FIG. 12 is a top view of the yoke of FIG. 1 .
[0023] FIG. 13 is a bottom view of the yoke of FIG. 1 .
[0024] FIG. 14 is a side view of the yoke of FIG. 1 .
[0025] FIG. 15 is an opposite side view of the yoke of FIG. 1 .
[0026] FIG. 16 is a cross-sectional view of the yoke of FIG. 1 , taken generally in a vertical plane through the axis.
[0027] FIG. 17 is a cross-sectional view of the yoke of FIG. 1 , taken generally in a horizontal plane through the axis.
[0028] FIG. 18 is a cross-sectional view of the yoke of FIG. 1 , taken generally through the shaft retaining pawls.
[0029] FIG. 19 is a cross-sectional view of the yoke of FIG. 1 , taken generally through the insert retaining members and the shaft retaining pawls.
[0030] FIG. 20 is a cross-sectional view of the yoke of FIG. 1 , taken generally through the insert retaining members.
[0031] FIG. 21 is a perspective view of an insert of the yoke of FIG. 1 .
[0032] FIG. 22 is another perspective view of the insert of FIG. 21 .
[0033] FIG. 23 is a front view of the insert of FIG. 21 .
[0034] FIG. 24 is a rear view of the insert of FIG. 21 .
[0035] FIG. 25 is a top view of the insert of FIG. 21 .
[0036] FIG. 26 is a bottom view of the insert of FIG. 21 .
[0037] FIG. 27 is a side view of the insert of FIG. 21 .
[0038] FIG. 28 is an opposite side view of the insert of FIG. 21 .
[0039] FIG. 29 is a cross-sectional view of the insert of FIG. 21 .
[0040] FIG. 30 is another cross-sectional view of the insert of FIG. 21 .
[0041] FIG. 31 is a front perspective view of an alternative construction of a collet locking yoke.
[0042] FIG. 32 is a front perspective view of the yoke of FIG. 31 with the retaining ring removed.
[0043] FIG. 33 is another front perspective view of the yoke of FIG. 31 .
[0044] FIG. 34 is a front perspective view of the yoke of FIG. 31 with the retaining ring removed.
[0045] FIG. 35 is a front perspective view of the yoke of FIG. 31 with the insert and the retaining ring removed.
[0046] FIG. 36 is a front view of the yoke of FIG. 31 .
[0047] FIG. 37 is a front view of the yoke of FIG. 31 with the retaining ring removed.
[0048] FIG. 38 is a rear view of the yoke of FIG. 31 .
[0049] FIG. 39 is a top view of the yoke of FIG. 31 .
[0050] FIG. 40 is a bottom view of the yoke of FIG. 31 .
[0051] FIG. 41 is a side view of the yoke of FIG. 31 .
[0052] FIG. 42 is an opposite side view of the yoke of FIG. 31 .
[0053] FIG. 43 is front perspective view of the yoke of FIG. 31 with the insert and the retaining ring removed.
[0054] FIG. 44 is a front view of the yoke of FIG. 31 with the insert and the retaining ring removed.
[0055] FIG. 45 is a cross-sectional view of the yoke of FIG. 31 , taken generally in a vertical plane through the axis.
[0056] FIG. 46 is a front perspective view of an insert of the yoke of FIG. 31 .
[0057] FIG. 47 is another front perspective view of the insert of FIG. 46 .
[0058] FIG. 48 is a rear perspective view of the insert of FIG. 46 .
[0059] FIG. 49 is a front view of the insert of FIG. 46 .
[0060] FIG. 50 is a rear view of the insert of FIG. 46 .
[0061] FIG. 51 is a top view of the insert of FIG. 46 .
[0062] FIG. 52 is a bottom view of the insert of FIG. 46 .
[0063] FIG. 53 is a side view of the insert of FIG. 46 .
[0064] FIG. 54 is an opposite side view of the insert of FIG. 46 .
[0065] FIG. 55 is a cross-sectional view of the insert of FIG. 46 .
[0066] FIG. 56 is another cross-sectional view of the insert of FIG. 46 .
[0067] FIG. 57A is a side view of the yoke of FIG. 31 .
[0068] FIG. 57B is a top view of the yoke of FIG. 31 .
[0069] FIG. 58A is a front view of the insert of FIG. 46 .
[0070] FIG. 58B is a top view of the insert of FIG. 46 .
[0071] FIG. 58C is a perspective view of the insert of FIG. 46 .
[0072] FIG. 58D is a cross-sectional view of the insert of FIG. 46 , taken along the line C-C in FIG. 58E .
[0073] FIG. 58E is a cross-sectional view of the insert of FIG. 46 , taken along the line A-A in FIG. 58D .
[0074] FIG. 58F is a cross-sectional view of the insert of FIG. 46 , taken along the line B-B in FIG. 58D .
[0075] FIG. 59A is a front view of a hub of the yoke of FIG. 31 .
[0076] FIG. 59B is a side view of the hub of FIG. 59A .
[0077] FIG. 59C is an enlarged view of Detail A in FIG. 59B .
[0078] FIG. 59D is an enlarged view of Detail B in FIG. 59B .
[0079] FIG. 60 is a partially exploded view of the yoke of FIG. 31 showing magnitudes of stress from use.
[0080] FIG. 61 is a front perspective view of another alternative construction of a collet locking yoke.
[0081] FIG. 62 is a front perspective view of the yoke of FIG. 61 with a retaining ring removed.
[0082] FIG. 63 is an exploded view of the yoke of FIG. 61 .
[0083] FIG. 64 is a front view of the yoke of FIG. 61 with the retaining ring removed.
[0084] FIG. 65 is a rear view of the yoke of FIG. 61 .
[0085] FIG. 66 is a top view of the yoke of FIG. 61 .
[0086] FIG. 67 is a bottom of the yoke of FIG. 61 .
[0087] FIG. 68 is a side view of the yoke of FIG. 61 .
[0088] FIG. 69 is an opposite side view of the yoke of FIG. 61 .
[0089] FIG. 70 is a front perspective view of the yoke of FIG. 61 with an insert and the retaining ring removed.
[0090] FIG. 71 is a front view of the yoke of FIG. 61 with the insert and the retaining ring removed.
[0091] FIG. 72 is a cross-sectional view of the yoke of FIG. 61 .
[0092] FIG. 73 is a front perspective view of the insert of FIG. 61 .
[0093] FIG. 74 is another front perspective view of the insert of FIG. 73 .
[0094] FIG. 75 is a front view of the insert of FIG. 73 .
[0095] FIG. 76 is a rear view of the insert of FIG. 73 .
[0096] FIG. 77 is a top view of the insert of FIG. 73 .
[0097] FIG. 78 is a bottom view of the insert of FIG. 73 .
[0098] FIG. 79 is a side view of the insert of FIG. 73 .
[0099] FIG. 80 is an opposite side view of the insert of FIG. 73 .
[0100] FIG. 81 is a cross-sectional view of the insert of FIG. 73 .
[0101] FIG. 82 is another cross-sectional view of the insert of FIG. 73 .
DETAILED DESCRIPTION
[0102] Before any independent embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other independent embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.
[0103] Use of “including” and “comprising” and variations thereof as used herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Use of “consisting of” and variations thereof as used herein is meant to encompass only the items listed thereafter and equivalents thereof.
[0104] FIGS. 1-82 illustrate motion transmitting mechanisms and components, such as yoke assemblies for coupling a farm implement to a tractor. Exemplary devices are shown and described in U.S. Pat. No. 5,779,385, filed Jan. 16, 1997, the entire contents of which are hereby incorporated by reference.
[0105] Referring to FIGS. 1-30 , a collet locking yoke 10 generally includes a yoke 14 , a hub 18 , and a collar 22 slidable on the hub 18 . The illustrated hub 18 defines a hub bore 26 which receives an insert 30 through an end 102 , and a retaining ring 168 abuts the front end 40 of the insert 30 and the hub bore 26 proximate the front end 102 . The opposite end 106 of the hub 18 mates with an end 110 of the yoke 14 . The hub 18 defines a number of radial openings 68 and 72 , and an outer surface of the hub 18 also defines a circumferential groove 148 proximate the front end 102 .
[0106] The collar 22 (see FIGS. 5-7 ) is annular and has opposite ends 114 , 118 . The rear end 118 is larger in diameter than the front end 114 . As best shown in FIGS. 16-17 , the collar 22 has an outer surface 122 that expands from the front end 114 to the rear end 118 . Further, the collar 22 has an inner surface 140 defining (see FIG. 16 ) a pocket 144 between the ends 114 , 118 . A snap ring 160 fits within the circumferential groove 148 in the hub 18 . A spring 164 (i.e., a compression spring), shown in FIGS. 16-17 , abuts the outer surface 122 of the hub 18 and extends from the inner surface 140 of the collar 22 to a radially-outwardly extending ridge of the hub 18 .
[0107] The insert 30 is shaped and sized to receive a splined shaft (not shown) through an end 40 of the insert 30 . In the illustrated construction, the splined shaft may be, for example, a six-spline power take off (PTO) shaft of a tractor. As best shown in FIGS. 21-24 , the insert 30 has a side wall 42 and defines an insert bore 44 defining insert grooves 48 separated by radially-inward extending splines 52 . The splines 52 have generally trapezoidal-shaped cross-sections and sloped surfaces facing towards the end 40 . The insert bore 44 , the grooves 48 , and the splines 52 together define an inner surface 56 which mates with the shaft.
[0108] The insert 30 has an outer surface 60 shaped and sized to mate with the hub bore 26 . In the illustrated construction, the outer surface 60 of the insert 30 , as best seen in FIGS. 23-24 , has a hexagonal cross-section. The hub bore 26 (see FIG. 10 ) has a cross-section which is complementary to and provides a driving engagement with the outer surface 60 of the insert 30 (in the illustrated construction, also hexagonal).
[0109] In the illustrated construction, a releasable insert retainer assembly is provided between the hub 18 and the insert 30 . The insert 30 defines a number of retainer openings 70 extending from the outer surface 60 toward the inner surface 56 aligned with the openings 68 in the hub 18 when the insert 30 is supported in the hub 18 . Each retainer opening 70 (and each associated hub opening 68 ) is shaped (e.g., round (as shown), rectangular, etc.) and sized to receive an insert retaining member 74 (e.g., a pin, a ball, etc.). In the illustrated construction, the insert retainer assembly includes four openings 70 and members 74 . As shown in FIG. 5 , the illustrated insert retainer members 74 are generally cylindrical with rounded ends.
[0110] Each retainer opening 70 has a reduced diameter at its radially inward end to prevent the retaining member 74 from extending too far into the bore 44 and/or from falling radially into the bore 44 (e.g., to limit or prevent interference with the shaft). In the illustrated construction, the insert retainer assembly is arranged proximate a rear end 78 of the insert 30 and along a center of the associated side of the insert 30 .
[0111] The retaining members 74 extend through the hub openings 68 and partially into the insert openings 70 to releasably retain the insert 30 in the hub 18 . As best shown in FIGS. 16-29 , the retaining members 74 abut the inner surface 140 of the collar 22 proximate the rear end 118 of the collar 22 .
[0112] In the illustrated construction, a shaft retainer assembly is provided between the hub 18 and the shaft. To accommodate the shaft retainer assembly, the insert 30 also defines a number of openings 82 aligned with the openings 72 in the hub 18 when the insert 30 is supported in the hub 18 . Each opening 82 (and each associated hub opening 72 ) is, each shaped (e.g., round, rectangular (square (as shown)), etc.) and sized to receive a shaft retainer member (e.g., a pawl 84 , a pin, a ball, etc.) such that the pawls 84 engage the shaft when the shaft is received in the bore 44 to limit relative movement. In the illustrated construction, the shaft retainer assembly includes two openings 82 and pawls 84 .
[0113] The illustrated pawls 84 are generally rectangular with angled end surfaces to facilitate insertion and removal of the shaft. Each opening 82 allows movement of the associated pawl 84 during insertion and removal of the shaft. Each opening 82 is also arranged along a center of the associated side of the insert 30 and more toward the rear end 78 than the front end 40 .
[0114] The pawls 84 engage the inner surface 140 of the collar 22 proximate the rear end 118 . The pawls 84 further extend through the hub openings 72 and through the insert openings 82 into the insert bore 44 . The ends of the pawls 84 extending into the insert bore 44 mate with a groove in the shaft when the shaft is received in the bore 44 to limit relative movement.
[0115] The hub 18 and the insert 30 cooperate to apply a clamping force to the shaft when torque is applied. The insert 30 further defines one or more slots 90 in the side wall 42 to allow movement of the side wall 42 (e.g., compression and expansion of the insert 30 ). The arrangement of the outer surface 60 of the insert 30 and the inner surface of the hub bore 26 causes compression of the insert 30 when torque is applied, and this compression causes the insert 30 to flex inwardly and apply a clamping force on the shaft.
[0116] In general, the outer surface 60 of the insert 30 and/or the inner surface of the hub bore 26 are configured to transmit torque and to provide an inwardly-directed force on the insert 30 . In other words, the outer surface 60 of the insert 30 and/or the inner surface of the hub bore 26 have an orientation between a solely circumferential orientation and a solely radial orientation. When torque is applied, the arrangement provides both a torque-transmitting force vector and an inwardly-directed insert-compressing force vector. As mentioned above, in the illustrated construction, the outer surface 60 of the insert 30 and the hub bore 26 have a hexagonal shape, with each engaging surface portion providing both torque transmission and compression.
[0117] The clamping force to be applied and the torque to apply the clamping force may be adjusted by changing the engagement between the outer surface 60 of the insert 30 and the hub bore 26 . For example, looking at FIGS. 9-10 and 23 , increasing the angle (becoming closer to a radial orientation) at the interface between the outer surface 60 of the insert 30 and the hub bore 26 (e.g., proximate the vertex) increases the force vector for torque transmission while decreasing the inwardly-directed insert-compressing force vector. Thus, compared to the illustrated angles, more torque is required to provide a comparable compression of the insert 30 , and the insert 30 may be “activated” (to apply a clamping force) relatively later, after reaching the higher torque level. Also, in this arrangement, for a given torque, compression of the insert 30 would be reduced, and less clamping force would be applied by the insert 30 .
[0118] Meanwhile, decreasing the angle (becoming closer to a circumferential orientation) at the interface decreases the force vector for torque transmission while increasing the inwardly-directed insert-compressing force vector. Thus, compared to the illustrated angles, less torque is required to provide a comparable compression of the insert 30 , and the insert 30 may be “activated” (to apply a clamping force) relatively earlier, after reaching the lower torque level. In this arrangement, for a given torque, compression of the insert 30 would be increased, and more clamping force would be applied by the insert 30 .
[0119] Accordingly, the outer shape of the insert 30 may be initially selected for a desired clamping force/torque relationship. Compared to the illustrated hexagonal cross-section, a square cross-section would provide an increased angle and require more torque to activate the insert 30 while an octagonal cross-section would provide a decreased angle and require less torque to activate the insert 30 . In still other constructions (not shown), the outer surface 60 of the insert 30 and/or the hub bore 26 may have a different shape (e.g., star-shaped, scallop-shaped, etc.) with convex portions, non-linear surfaces, etc.
[0120] In some constructions (not shown), the angle proximate the interface may change during operation. For example, the shape of the outer surface 60 of the insert 30 and/or the inner surface of the hub bore 26 may not be constant but may change along the interface. As torque is applied, the location where the force is being applied may change along this non-constant interface, and the clamping force/torque level for activation may change. In a specific example, the shape of the outer surface 60 of the insert 30 and/or the inner surface of the hub bore 26 may be arranged to provide early activation of the insert 30 (a shallow angle at the interface) and then to provide a constant clamping force as torque increases (a rising angle). In another example, the shape of the outer surface 60 of the insert 30 and/or the inner surface of the hub bore 26 may be arranged to provide delayed activation of the insert 30 (a steep angle at the interface) and then to provide a rapidly-increasing clamping force as torque increases (a decreasing angle).
[0121] In the illustrated construction, the slot(s) 90 extend from one end toward the other end of the insert 30 . Each illustrated slot 90 is arranged along the center of the associated side of the insert 30 and through a center of an opening 70 or 82 , where provided. A thickness 94 of material is provided at the base of each slot 90 , and, in the illustrated construction, the base of each slot 90 is curved.
[0122] As illustrated, a number of slots 90 a (e.g., three) extend from the front end 40 toward the rear end 78 , and a number of slots 90 b (e.g., three) extend from the rear end 78 toward the front end 40 , such that, in the illustrated construction, as best shown in FIGS. 21-30 , there are six such slots 90 . With grooves 90 a, 90 b extending from each end 40 , 78 , the insert 30 is compressed and clamping force is applied to the shaft at each end of the insert 30 . The illustrated slots 90 a, 90 b alternate circumferentially about the insert 30 which contributes to centering of the shaft in the insert 30 .
[0123] In other constructions (not shown), the insert 30 can define different numbers of slots 90 , including more or fewer than the six slots 90 as illustrated. The slot(s) 90 may be in different locations on the insert 30 . For example, in FIGS. 73-82 , the slots 90 B extend only from one end 40 B. As other examples, the slot(s) 90 may not be along the center of the side of the insert 30 , may not extend through an end 40 , 78 of the insert 30 (be located intermediate the ends 40 , 78 ), etc. The slot(s) 90 may have a different orientation on the insert 30 (e.g., not aligned with the axis of the insert (skewed; not shown), non-linear (curved; not shown), combinations, etc.), shape (e.g., the base of each slot 90 may be square (see FIGS. 73-82 )), the slot(s) 90 may have non-parallel walls, etc.), etc.
[0124] The flexibility of the insert 30 , which may affect the clamping force applied, the torque to apply the clamping force, etc., may be adjusted. For example, the thickness 94 of material can be increased to reduce the flexibility or decreased to increase the flexibility. The thickness of the wall 42 of the insert 30 can similarly be adjusted to increase or decrease the flexibility of the insert 30 . Material(s) of the insert 30 may also be selected to provide a desired flexibility/range.
[0125] To assemble the yoke 10 , the rear end 118 of the hub 18 is coupled to the front end 110 of the yoke 14 . The pawls 84 and the retaining members 74 are inserted into the respective openings 68 , 72 in the hub 18 . The spring 164 is placed about the outer surface of the hub 18 and is compressed towards the rear end 106 of the hub 18 . The collar 22 is placed about the outer surface 122 of the hub 18 , and, with the spring 164 under compression, the snap ring 160 can be placed in the circumferential groove 148 . The spring 164 can then be uncompressed, as the snap ring 160 will hold the front end 114 of the collar 22 in place against the force of the spring 164 . The collar 22 radially retains both the pawls 84 and the retaining members 74 within the yoke 10 .
[0126] To place the insert 30 into the hub 18 , the collar 22 is pushed back toward the rear end 106 of the hub 18 , allowing the pawls 84 and the retaining members 74 to move radially outwardly and into the pocket 144 . The insert 30 is then slip fit into the hub 18 , with the insert pawl openings 82 aligned with the hub pawl openings 72 and the insert retaining member openings 70 aligned with the hub retaining member openings 72 .
[0127] The retaining ring 168 is compressed and inserted into the hub 18 to abut the front end 40 of the insert 30 and to cooperate with the retaining members 74 to retain the insert 30 in the hub 18 . The collar 22 is released and moves forward under the force of the spring 164 until engaging the snap ring 160 . With assembly of the yoke 10 complete, the retaining members 74 axially retain the insert 30 in the hub 18 .
[0128] In use, the shaft is inserted into the bore 44 of the insert 30 with a slip fit, with the splines of the shaft within the insert grooves 48 and the splines 52 of the insert 30 between the shaft splines. The pawls 84 move into a circumferential groove in the shaft and shaft splines to axially retain the shaft in the hub 18 . The pawls 84 also cooperate to retain the insert 30 in the hub 18 .
[0129] During operation, a driving force is applied to the motion-transmitting mechanism (e.g., the shaft is driven by an external means (not shown, e.g., a tractor)). The splines of the shaft engage the splines 52 of the insert 30 to transmit torque on the insert 30 . The outer surface 60 of the insert 30 engages the hub bore 26 . Through engagement of the outer surface 60 of the insert 30 and the hub bore 26 , torque is transmitted to the hub 18 and therethrough to the yoke 14 and to any implement (not shown) coupled to the yoke 14 .
[0130] As discussed above, as torque is applied, the engaging surface portions of the outer surface 60 of the insert 30 and the hub bore 26 provide both torque transmission and compression. The insert 30 is “activated”—compressed and flexes to apply a clamping force to the shaft. As also discussed above, the clamping force applied and the torque for activation of the insert 30 is related to the shape of the interface between the outer surface 60 of the insert 30 and the hub bore 26 as well as the arrangement of the slot(s) 90 .
[0131] To remove the shaft, rotation of the shaft is first stopped. Ceasing rotation of the shaft and transmission of torque removes the clamping force exerted on the shaft by the insert 30 . The collar 22 is retracted to allow the pawls 84 to move outwardly and the shaft to be removed.
[0132] To remove the insert 30 , the retaining ring 168 is removed. The collar 22 is retracted to allow the pawls 84 and the retaining members 74 to move outwardly from the respective openings 70 , 82 in the insert 30 . The insert 30 can then be removed. The insert 30 or a new insert (not shown) can be replaced as described above. The new insert may be provided to replace a worn insert 30 or to provide an insert having a different configuration (e.g., different splines (number, shape), grooves, dimensions, material(s), etc.).
[0133] FIGS. 31-60 illustrate an alternative embodiment of a collet locking yoke 10 A. The yoke 10 A and its components are similar to the yoke 10 and components shown in FIGS. 1-30 and described above. Common components have the same reference number “A.” The yoke 10 A is assembled and operated in a similar fashion as the yoke 10 .
[0134] The yoke 10 A is a larger version of a constant velocity yoke compared to the yoke 10 which is a middle size constant velocity yoke. As illustrated, the insert 30 A has (see FIGS. 48 and 51 - 54 ) a flat surface at the rear end 78 A and (see FIGS. 46-47 and 51-54 ) an increased taper of the edges at the front end 40 A, compared to the insert 30 .
[0135] FIGS. 61-82 illustrate another alternative embodiment of a collet locking yoke 10 B. The yoke 10 B and its components are similar to the yoke 10 , 10 A, and components shown in FIGS. 1-30 and 31-60 , respectively, and described above. Common components have the same reference number “B.” The yoke 10 B is assembled and operated in a similar fashion as the yoke 10 , 10 A.
[0136] The yoke 10 B is a large standard yoke and includes an integral yoke 14 B and hub 18 B. The insert 30 B defines only slots 90 B extending from one end (e.g., the front end 40 B) toward the other end (e.g., the rear end 78 ). This arrangement of the slots 90 B provides clamping force on the shaft proximate the one end (e.g., the front end 40 ) during torque transmission. The base of the illustrated slots 90 B is square.
[0137] In the illustrated constructions, the inserts 30 , 30 A, 30 B are formed of steel. The illustrated hexagonal inserts 30 , 30 A, 30 B may be formed from commonly-available steel hex bar stock by machining, forging, etc., to provide the illustrated structure (e.g., the bore 44 (with the grooves 48 and the splines 52 ), the openings 70 , 82 , the slot(s) 90 ). In other constructions, the inserts 30 , 30 A, 30 B may be formed of other suitable materials, such as powdered metal, and in an appropriate process (e.g., forging, investment casting, extrusion, etc.) to provide the illustrated structure.
[0138] In the yokes 10 , 10 A, 10 B, clamping of the insert 30 , 30 A, 30 B on the shaft during rotation of the shaft and torque transmission reduces or eliminates vibrations during operation. In other words, play between the insert 30 , 30 A, 30 B and the shaft (beneficial for insertion and removal of the shaft) is reduced when torque is transmitted.
[0139] In some constructions, rotation of the shaft at “no load” is sufficient to cause the insert 30 , 30 A, 30 B to compress and apply a clamping force on the shaft sufficient to eliminate vibration, play, etc.
[0140] The six spline shaft with which the insert 30 , 30 A, 30 B mates is designed to operate at 540 revolutions per minute (RPM). At higher speeds (e.g., 1,000 RPM), however, vibrations may be experienced. Such vibrations can cause unease to the operator, who may believe the machine is worn or starting to fail, discomfort, etc. Further, vibrations may lead to wear and eventual failure of the shaft and/or components of the yoke 10 , 10 A, 10 B.
[0141] With the illustrated slots 90 , 90 A, 90 B spaced about the circumference of the insert 30 , 30 A, 30 B compression of and the clamping force exerted on the shaft by the insert 30 , 30 A, 30 B contributes to centering of the shaft in the insert 30 , 30 A, 30 B and the hub 18 , 18 A, 18 B. Centering the shaft provides smoother operation of the shaft and the yoke 10 , 10 A, 10 B.
[0142] This centering of the shaft may be especially useful in a straight sided “type 1” tractor PTO shaft (see, e.g., International Standards Organization (ISO) 500 for agricultural tractors), which is not self-centering, but may also be beneficial for self-centering shafts with involute or curved splines. Further, as discussed above, ceasing rotation of the shaft and torque transmission eliminates the clamping force on the shaft and allows the shaft to be easily removed, as needed.
[0143] By using the yokes 10 , 10 A, 10 B and the inserts 30 , 30 A, 30 B shown above, a shaft designed to rotate at one speed (e.g., at 540 RPM) can be operated a higher speed (e.g., at 1,000 RPM or higher) without increased vibration or different components. This ability to increase the operating speed of the shaft without using a different shaft and/or yoke may meet a growing market need. For example, in many PTO systems, the type 1 shaft has to be replaced with a “type 2” or “type 3” shaft for applications at speeds higher (e.g., 1,000 RPM) than the type 1 shaft was designed (540 RPM).
[0144] Further, even higher RPMs could be accommodated by use of the yokes 10 , 10 A, 10 B, and the inserts 30 , 30 A, 30 B described above. For example, new, larger and heavier drive shafts (e.g., shafts designed to run at 1540 RPM) are becoming more prominent. These heavier shafts and the associated yokes are even more sensitive to vibration than lighter shafts/yokes and may benefit even further from mating with vibration-reducing, shaft-centering yokes 10 , 10 A, 10 B and inserts 30 , 30 A, 30 B as described above.
[0145] In other constructions (not shown), an insert may have a different construction (e.g., a different shaft interface (not shown) to mate with a different shaft, formed of different material(s), etc.) while still being usable with the yoke 10 and insertable into the hub bore 26 . For example, such an alternative insert may have an interface configured to receive a twenty-one splined shaft. In such a construction, the twenty-one spline insert may have an outer surface similar to the six spline insert 30 and/or complementary to the shape of/able to be in driving engagement with the hub bore 26 .
[0146] Independent of the compressible, clamping features, the arrangement of a removable/replaceable insert 30 , 30 A, 30 B in the hub bore 26 , 26 A, 26 B of the yoke 10 , 10 A, 10 B may provide a modular arrangement such that a given yoke 10 , 10 A, 10 B may be used with machines having different shafts (e.g., type 1, 2, 3, etc.). This arrangement may also independently provide replacement of the insert 30 , 30 A, 30 B, as needed, due to wear, failure, etc., for example, of the shaft interface in the insert bore 44 .
[0147] One or more independent features and/or independent advantages of the invention may be set forth in the following claims:
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An insert, a motion-transmitting mechanism and a method of operating a motion-transmitting mechanism. The insert may include an insert body receivable in a bore, the insert body having an outer surface at least partially engageable in a driving relationship with a bore surface, the insert body defining an insert bore operable to receive a shaft in a driving relationship, torque transmission between the shaft and the motion-transmitting member through the insert body causing a portion of the insert body to compress toward the shaft.
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[0001] The present invention relates to apparel or clothing having pockets and, more particularly, to underwear having; a discreet concealed pocket for securely and safely holding valuables and other items therein; in relation to underwear for males improved support for male genitalia providing improvements in health and comfort.
BACKGROUND TO THE INVENTION
[0002] There exists prior art in relation to the design and manufacture of clothing and underwear and including pockets, such as for example U.S. Pat. Nos. 7,231,672 (Thomas), 8,321,964 (Gernes) 7,926,123 (Walburg), 6,353,940 (Lyden) and 7,676,853 (Cutlip)
[0003] One problem that exists in our society today wherein we seek to direct the attention especially of the younger generations to the use of condoms for “safe sex”, we find that at least some of the younger generation are embarrassed to carry condoms because the condoms may become visible to their peers or elders such as in a wallet or handbag.
[0004] Another problem that exists with prior art apparel pockets is that the pockets and their contents tend to bunch up tending to become more visible and uncomfortable when the wearer transitions from a standing to a seated position. Also, flexing of individual condom packets can contribute to degrading the effectiveness of the condom.
[0005] Another problem that exists in relation to prior art underwear is that there is a need to maximise the comfort to the wearer without unduly constraining the body and to avoid increasing temperature of body parts which can have or at least contribute to deleterious effects, including deleterious effects on male fertility.
[0006] It an object of the present invention to provide items of clothing including a discreet and secure pocket means of carrying at least a condom and having an improved design to eliminate or at least minimise aspects deleterious to male fertility
[0007] Whereas the aforesaid art is directed to the formation of various pocket-equipped garments and in some instances concealed pockets, no effort has been made to form a garment pocket, having due regard to the locus of the inguinal creases, and the pocket opening such that the garment pocket and contents thereof will not bunch up and will be urged to, without crushing bending or folding, lie mostly against either the lower torso or the upper leg when the wearer of the garment is in sitting position This invention, as will be noted, is directed to the latter, in distinction over the prior art
SUMMARY OF THE INVENTION
[0008] Any discussion of the prior art throughout this specification should in no way be considered as an admission that such prior art is widely known or forms part of common general knowledge in the field.
[0009] Pockets in outer and underwear can present an unattractive view and can be uncomfortable to the wearer when the wearer transitions from an upright to a seated position, whereby the pocket and contents become folded or are urged to become a more visible protrusion deleterious to the comfort of, or annoying to, the wearer. The folding or compressing of pocket and contents especially in a sitting position depends mainly on the design and positioning of the pocket so that it is not folded in the inguinal creases as the wearer transitions from a standing to a sitting position. Said inguinal creases normally being located on the body of a person at or in close proximity to the juncture between the lower torso and uppermost area of each leg so that a theoretical line drawn from the end of each of the 2 inguinal creases would meet and form a ‘V’ at the groin of the wearer
[0010] Present social mores direct attention especially of the younger generations to the use of condoms for “safe sex” However, it can often be embarrassing to the younger generations to visibly carry such items.
[0011] It is an object of the present invention to provide a discreet pocket, in clothing including underwear, to contain at least one or more of a condom or a credit card or money and to at least improve the comfort of the wearer and minimise the visual discernibility of the pocket on the garment.
[0012] In one preferred embodiment the present invention underwear pants, being described in the normal position of a wearer who is standing upright, are made of preferably a stretch fabric containing at least 3% spandex and having a pocket formed so that the said pocket is attached to or spaced apart from or immediately adjacent to the lower edge a waistband of thicker elasticised material on the internal front wall of said underwear pants by affixing by known means a piece of similar fabric having at least a portion of the edge of the fabric not affixed so as to create an opening to the pocket and disposed so that in the process of the wearer transitioning from a standing position to a seated position the pocket and contents thereof are urged to lay flat against the lower torso or to lay flat against or form a discrete fold lying flat against the upper leg of the wearer below the inguinal crease. Additionally, Said underwear pants also may be sold to consumers together with a condom in the said pocket.
[0013] In yet another embodiment of the present invention pants including underwear pants, being described in the normal position of a wearer who is upright, are made of preferably a stretch fabric containing at least 3% spandex and having a packet formed by affixing by known means a piece of similar fabric having at least a portion of the edge of the fabric not affixed or alternatively releasably affixed so as to create an opening to the pocket which may be held closed by means such as indicated in U.S. Pat. Nos. 8,321,964 (Games) and 7,926,123 (Walburg) and said pocket being disposed so that the lower edge, being the edge opposite to the opening, is located above the inguinal crease, and further disposed so that in the process of the wearer transitioning from a standing position to a seated position the pocket and contents thereof are urged to remain approximately fiat against the lower torso or to lay flat or in close proximity to the surface of the upper leg or form a discrete fold laying flat or in close proximity to the surface of the upper leg.
[0014] In another embodiment of the present invention the pocket opening may additionally have a known means to securely close the opening by known means such as by a flap and or zip and or Velcro such as indicated in U.S. Pat. No. 7,926,123 (Walburg) and said pocket may advantageously be located on the internal front wall of said underwear pants and affixed on, or spaced apart from or immediately adjacent to the lower edge of, a waistband of thicker elasticised material
[0015] In another preferred embodiment the present invention pants and pocket, the said pocket consists of a piece of material or fabric releasably affixed to the internal surface of the underpants such that the contents desired to be held in the pocket are held between the releasably affixed fabric and the inner wall of the garment at a desired location. Said releasably affixed fabric may be affixed by any suitable means such as Velcro or gluing as indicated in U.S. Pat. No. 8,321,964 (Gernes). The location of the pocket in pants is defined by the location of the pocket opening in relation to the inguinal crease. The pocket opening being at the upper edge of the pocket when the wearer of the pants is in a upright position.
[0016] In another embodiment of the present invention pants with pocket, the pocket consists of front and back walls of Material affixed together by known means as indicated in U.S. Pat. No. 7,231,672 (Thomas) leaving an opening at one end and said pocket is affixed to the desired location according to the invention on an inside surface of said pants.
[0017] In prior art underwear for men eg Bonds style CL500223 032 and many others the structure of the underwear garment includes an integral frontal “pouch” (Pouch) constructed from shaped pieces of material or cloth or fabric (Material) sewn together to make the Pouch. The said Pouch provides a cover to contain and support male genitals. The shape of said Pouch is determined by the relative measurements and shape of the pieces of Material as cut and the way in which said pieces of Material are sewn together
[0018] In Prior art, the ratio of the average width of the top and bottom seams of the Pouch i.e. the sum of the length of the top and bottom seams or edges of the Pouch measured between the edge seams at the top (top meaning at or adjacent to the waist or waistband of the garment and crotch) expressed as a proportion of the width of Pouch at widest part between centres of side edges seams (Widest Width) is less than 2.3 (Ratio A) and the ratio of the Widest Width divided into the length of the vertical centre line of the Pouch is greater than 1.6 (Ratio B).
[0019] In a preferred embodiment of the present invention the Ratio A is at least 2.3 and the Ratio B is less than 1.40 or 1.55 or 1.60 and when measured from centres of side seams at , or as close as possible to, 90 degrees to the said edge seams and the garment unstretched not while someone is wearing hem which is the method of measuring used herein.
[0020] In yet another preferred embodiment a Pouch may be formed by shaping one or more pieces of fabric or material by known means to adopt a form having dimension whereby the said Ratio A is at least 2.3 and the said Ratio B at least less than 1.48 or 1.55 or 1.60.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 . is a front elevation view of a lower torso and upper legs in a standing position wearing pants outlined in dotted lines and including 3 pockets according to the present invention.
[0022] FIG. 2 . is an enlarged sectional view of the invention of FIG. 1 taken between the lines 2 - 2 in FIG. 1 but with the wearer of the pants having transitioned from a standing to a sitting position.
[0023] FIG. 3 . is a front elevation view of a lower torso and upper legs in a standing position showing the approximate location of the inguinal crease and the zones in which a pocket may be located in a preferred embodiment of the present invention.
[0024] FIG. 4 . is a plan frontal view of elements of pants showing; the disposition of elements consisting a Pouch giving improved and healthy support and less restriction to the male genitals and the relevant elements relevant to measurements and proportional ratios of the present invention. Element 65 is one of 2 leg accommodating openings.
[0025] FIG. 5 . Is a sectional view, in the direction indicated by dotted line 3 to 3 in FIG. 4 , of pouch 330 taken through seam 315 between centres of seams or edges 340 and 335 showing the curved form of the Pouch extending from the centre of seam 335 along the whole length of seam 315 to the centre of seam 340 .
[0026] FIG. 6 . Is a sectional view of pouch 330 taken through line 4 - 4 in FIG. 4 ) in a view towards the waistband 60 (not shown) and is the section showing the widest width portion of the Pouch 330 between sides/seams 345 and 350 .
DESCRIPTION OF PREFERRED EMBODIMENTS
[0027] FIG. 1 is a front elevation view of a lower torso and upper legs 10 in a standing position and showing the approximate location of the inguinal crease 20 . Said inguinal crease has a corresponding mirror image inguinal crease on the opposite side of the body. The said torso is displayed wearing pants 50 of a modified boxer style having a short leg portion 55 and also having one or more of pockets 70 , 74 and 78 of the present invention. Said pants and pockets outlined in dotted lines and further showing by dotted lines a waist band 60 made of a thicker more strongly elastic material. Said one or more pocket affixed or releasably affixed by known means but leaving one end unaffixed to create en opening to said pocket.
[0028] FIG. 2 is a sectional view of portion of pants 50 including pocket 74 and waistband 60 along the dotted line 2 - 2 in FIG. 1 but with the wearer of the said pants represented in a seated position said wearer represented by the lower torso and upper legs 10 ; lower torso 12 ; lower torso surface 15 ; upper leg 14 : and upper leg surface 25 . The present invention combination of pants 50 and pocket 74 shows said pocket having; a front wall consisting of portion of pants front wall of 105 affixed by known means to the lower portion of waistband 60 ; a back wall 150 ; an optional flap or closure means 160 , said pocket depicting contents 170 said pocket and contents and portion of the front wall of the pants 105 laying substantially without twisting or bending or folding of contents 170 together with part of a fold 150 in the said front wall 105 against or in close proximity to the surface 25 of upper leg 14 of the wearer.
[0029] FIG. 3 . Is a representation of a lower torso and upper part of the legs 10 in a standing position and showing the approximate location of the inguinal crease 20 and a triangular area 210 outlined in dotted lines surrounds the preferred area of the body surface adjacent to which at least a major portion of the open end of a pocket formed on pants may be advantageously located when for example pants containing said pocket are worn by a wearer in a standing position A further triangular area 230 outlined in dotted lines surrounds a second preferred area of the body adjacent to which at least the open end of a pocket may be located with opening to the said pocket being the uppermost portion of the said pocket when pants containing said pocket are worn by a wearer in a standing position. The sides of triangles 210 and 230 adjacent to the inguinal crease 20 are approximately 15 mm apart and parallel. Side 212 of triangle 210 is located between 50 mm and 75 mm from a vertical centerline passing through the umbilicus and shown as a dotted line A A.
[0030] The foregoing description applies to both left and right sides of a body and corresponding pants as in a horizontally flipped or reversed image thereby producing a corresponding 2 similarly located triangles on the corresponding opposite side of said body
[0031] FIG. 4 . Is a representation of the front portion of pants 50 oriented approximately as the said pants would appear when worn by a person thus having waistband 60 or similar located above the other parts of the said pants. The present invention includes an improved means of covering and supporting male genitals in a cooler more healthy and less constricting way than prior art. In the present embodiment, more than one shaped pieces of stretchable cloth in this example there are 2 pieces 310 and 320 are affixed together at one edge (unnumbered) at seam 315 by known means and further affixed at seams and or edges 335 , 340 , 345 and 350 to other elements, including, crotch piece 329 to form pants having a shaped cover or Pouch 330 bounded by edges and or seams at edges 335 , 340 , 345 and 350 and having a seam 315 which in this preferred example is a central seam bisecting the said pouch vertically (vertically referring to the orientation of said pants when worn by a wearer.
[0032] Alternate arrangements may also be made so that more than 2 pieces of said stretchable cloth may be used in place of said pieces 310 and 320 and may have seams oriented differently to the examples herein. The said shaped pieces of stretchable cloth 310 and 320 ; are in this example mirror images of each other; and for sake of simplifying drawings the edges numbered 335 and 340 of said pieces 310 and 320 are not separately shown in FIG. 4 but instead the combined edge of joined pieces 310 and 320 are referred to as edges or seams 335 and 340 contiguous across said pieces 310 and 320 .
[0033] In a preferred embodiment of the present invention, the Widest Width of the Pouch measured between centres of seams/curved sides 345 and 350 at the intersections with section line 4 - 4 (also referred to as measurement 328 in FIG. 6 ) divided by half the sum of the lengths of sides 335 and 340 using the same unit of measure, produces a ratio of at least 2.25 or 2.3 and in the same preferred embodiment the length of curved side or seam 315 measured between seams/sides 335 and 340 and (also referred to as measurment 318 in FIG. 5 ) divided by the aforesaid Widest Width and using the same units of measure, produce a ratio of less than 1.6 or 1.5 or 1.45 Section line 3 - 3 has been drawn in FIG. 4 . slightly apart from seam 315 for reason of visibility but the actual measurement is taken at and section 3 - 3 shown in FIG. 6 . is contiguous with seam 315 .
[0034] In yet another embodiment (not shown) the Pouch may be formed of one or more pieces of formable fabric by known means such as, being placed or held in a mold or over a shape of the desired proportions of the Pouch and set by known means such as heat so that Pouch is urged to configure to the desired shape and then tend to remain as set until the said fabric is stretched during wearing but when the said fabric returns to an unstretched state , the Pouch re-assume the desired shape of the present invention.
[0035] FIG. 5 . Is a sectional view of pouch 330 taken through seam 315 (also referred to as being the view section line 3 - 3 in the explanation to FIG. 4 ) between centres of seams or edges 340 and 335 showing the curved form of the Pouch extending as shown by the bracket 318 from the centre of seam 335 joining pouch edge 335 with waistband 60 along the whole length of seam 315 to the centre of seam 340 joining pouch edge 340 to crotch piece 329 (refer FIG. 4 ). Said measurement 318 is also referred to as the measurement of the seam length 315
[0036] FIG. 6 . Is a sectional view of pouch 330 taken through line 4 - 4 in FIG. 4 ) in a view towards the waistband 60 (not shown) and is the section showing the widest width portion of the Pouch 330 ; said Widest Width as depicted by bracket 328 being measurement between centres of seams 345 and 350 or may also be described as measurement between edges 345 and 350 of joined cloth pieces 310 and 320 said join being seam 315 .
[0037] While there has been shown and described preferred embodiments of apparel with concealed pocket in accordance with the invention. it will be appreciated that, many changes and modifications may be made therein without, however, departing from the essential spirit and scope thereof.
[0038] All publications, patents, patent applications, and other documents cited in this application are incorporated by reference in their entirety for all purposes to the same extent as if each individual publication, patent, patent application, and/or other document were individually indicated to be incorporated by reference for all purposes.
REFERENCES CITED
[0039] U.S. Pat. Nos.
7,231,672 (Thomas), 8,321,964 (Games) 7,926,123 (Walburg), 6,353,940 (Lyden) 7,676,853 (Cutlip) 666,246 (Henderson) 2,498,048 (Neinken) 2,544,840 (Kowatsch) 3,137,862 (Mizerk) 3,149,343 (Jacobson) 4,006,494 (Knoppel) 4,068,321 (Chayer) 4,077,067 (Kozdal) 4,139,914 (Tarr) 4,145,762 (Wallach) 5,561,865 (Fjelstul) 6,199,215 (Biggerstaff)
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Underwear having a concealed pocket for securely and safely holding valuables and other items therein and including underwear for males having improved design for health and comfort.
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PRIORITY CLAIM
[0001] This application is a continuation-in-part of application Ser. No. 11/741,249 filed on Apr. 27, 2007 entitled Spinal Implant, the contents of which are hereby expressly incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to spinal implants inserted between adjacent vertebrae to stabilize the intervertebral space and correct the angle of the spine. The implant also facilitates fusion of the affected vertebrae.
[0004] 2. Description of the Prior Art
[0005] The spinal cage is a well known device for insertion between vertebrae to provide support in lieu of the natural spinal disc. The cages may be of different shapes, including rectangle, cylinder and wedge, enclosing an interior filled with bone growth material, among other compositions, which promote the fusion of the vertebrae on each side of the cage. The cages are open structures which allow vascularization and bone in-growth.
[0006] It is very important that these cages be prevented from migrating out of the prepared surgical site because any movement will prolong the fusion process and traumatize healthy tissue.
[0007] U.S. Pat. No. 6,746,484 B1 to Liu et al illustrates such a wedge shaped cage with rectilinear ends. Liu et al is directed to proper placement of the cage so that the large and small ends of the wedge are support members and the interconnected sides facilitate fusion or bone growth. Distractors with screw-like threads are used to form a shaped bed in the end plates of the adjacent vertebrae to accept the cage. The cage has two open opposite long sides and two closed long sides. The filled cage is inserted into the prepared site and rotated 90 degrees so that the open sides will be in contact with the end plates of the adjacent vertebrae. The cage is held in place by compression between the vertebrae.
[0008] U.S. Pat. No. 5,425,772 to Brantigan is directed to another wedge shaped implant similar to the cage described above. The surgical site is prepared by cutting slots in the adjacent vertebrae end plates and separating the end plates by distraction. The closed long sides have a series of sharpened ridges or teeth extending across the closed sides parallel to the ends. The teeth are shaped as elongated isosceles triangles for biting into the adjacent vertebrae surfaces when implanted. The valleys between the teeth are filled with bone growth material to promote fusion. After implantation, the distraction is released to reduce the space between the vertebrae and to seat the implant by compression.
[0009] What is lacking in the prior art is a spinal cage which has a large open vertebral contact area for boney in-growth and a locking structure to prevent ventral and dorsal movement after implantation and a cage that can provide lordosis, mimicking the natural curvature of the spine.
SUMMARY OF THE PRESENT INVENTION
[0010] Therefore, an object of this invention is to provide a spinal implant sized and shaped to support adjacent vertebrae in the proper angular and spatial relationship.
[0011] It is another object of this invention to provide a spinal implant cage with a hollow interior to serve as a reservoir of bone growth material and to provide a large contact area between the material and the vertebrae.
[0012] It is a further object of this invention to provide a plurality of angled teeth securing the cage to the end plates of the vertebrae and preventing migration of the implant from the implant site.
[0013] It is yet another object of this invention to provide a method of implanting the cage by rotation of the cage to engage the angled teeth in the end plates of the vertebrae.
[0014] It is a still further object of this invention to provide a wedge shape in which the major distraction distance shifts from the trailing end to the leading end as the cage is rotated.
[0015] It is still yet an object of this invention to provide a method of facilitating the rotation of the cage by providing a recessed surface areas along the elongated side walls to minimize the stress placed on adjacent vertebrae as the cage is rotated.
[0016] It is further still yet an object of this invention to provide a stop plate to prevent over rotating the cage to an undesirable position.
SHORT DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a perspective view of the spinal cage of this invention;
[0018] FIG. 2 is a top plan view of the cage of FIG. 1 ;
[0019] FIG. 3 is a side plan view of the cage of FIG. 1 ;
[0020] FIG. 4 is an exploded perspective of another embodiment of the cage of this invention;
[0021] FIG. 5 is a perspective view of another embodiment of the spinal cage of this invention;
[0022] FIG. 6 is a top view of the cage of FIG. 5 ;
[0023] FIG. 7 is a side plan view of the cage of FIG. 5 ;
[0024] FIG. 8 is a partially exploded view of the spinal cage of FIG. 5 including radiopqaue rods;
[0025] FIG. 9 is a perspective view of another embodiment of the spinal cage invention;
[0026] FIG. 10 is a top view of the spinal cage of FIG. 9
[0027] FIG. 11 is a partially exploded view of the spinal cage of FIG. 9 including radiopqaue rods;
[0028] FIG. 12 is another perspective view of the spinal cage shown in FIG. 9 ;
[0029] FIG. 13 is another top view of the spinal cage shown in FIG. 9 ; and
[0030] FIGS. 14 and 15 are end views of the spinal cage shown in FIG. 9 .
DETAILED DESCRIPTION OF THE INVENTION
[0031] The spinal implant is formed as a cage 10 with a hollow interior 30 , as shown in FIG. 1 , surrounded by an open framework. The cage shown in FIGS. 1 , 2 , and 3 has an overall shape of a wedge with a smaller end wall 14 and a larger end wall 15 . As shown in FIGS. 1 and 4 , the leading end 15 is longer than trailing end 14 . Elongated sidewalls 12 and 16 connect the ends and are disposed diametrically opposite to each other. Sidewall 12 has apertures 18 and 19 which communicate with the interior 30 . Sidewall 16 is a mirror image of sidewall 12 and includes apertures 20 and 21 . The apertures in the sidewalls may be the same size or different sizes, as shown. The apertures contribute to the integration of the implant into spine. The cage may be made of surgical stainless steel, titanium, other metallic alloys, ceramics, polymeric material or combinations thereof that are bio-compatible and have sufficient strength to support adjacent vertebrae in desired spatial relationship with proper curvature of the spine.
[0032] Along the longitudinal periphery of the sidewall 12 is a series of teeth terminating in a sharpened apex. On one portion of the periphery the teeth 24 and 26 are angled away from the small end 14 . In the other portion of the periphery of sidewall 12 , the teeth 25 and 27 are angled toward the small end wall 14 , as shown in FIG. 3 . The periphery of sidewall 16 is similarly shaped with the teeth 22 angled away from the small end wall 14 and the teeth 23 angled toward the small end wall 14 . The angled teeth gain purchase in the bone and act as a ratchet to prevent relative movement between the implant and the end plates of the adjacent vertebrae. The opening 30 between the periphery of side walls 12 and 16 communicates with the hollow interior of the cage. When the cage is filled with bone growth and/or other material, this large opening on either side of the cage provides a large contact area to promote boney in growth, vascularization and fusion of the adjacent vertebrae.
[0033] The end smaller wall 14 , shown in FIG. 1 , has an oblong opening 31 which mates with an implant tool (not shown) used to manipulate the implant for permanent positioning in the spine. The longer end wall 15 has a threaded opening 32 opposite the opening 31 to which the implant tool may be removably connected. These openings, 31 and 32 , may be reversed.
[0034] The manipulation would normally include insertion through a percutaneous opening in the patient's back and sliding the implant into a prepared site between lumbar vertebrae. The longer end wall 15 is the leading end with the smooth width of one of the sidewalls contacting the upper vertebrae and the other sidewall contacting the lower vertebrae. To this end, the sidewalls 12 and 16 are bowed outwardly in an arc increasing the volume of the hollow interior and reducing the area of sliding contact with the vertebral end plates. Also, the end walls 14 and 15 may be rectilinear with the sidewalls connecting the opposite sides of the rectangles so that the implant has a low profile during insertion within the prepared spinal site. The low profile leading end is shown in the insertion phase in FIG. 2 .
[0035] Once within the spinal site, the implant is rotated approximately 90 degrees to orient the width of the sidewalls of the implant more or less parallel with the longitudinal axis of the spine and engage the teeth with the end plates of the adjacent vertebrae. The rotation results in increasing the profile of the cage at the leading end and reducing the profile at the trailing end, as shown by a comparison of FIG. 2 and FIG. 3 .
[0036] The implant tool is then removed. The hollow interior 30 of the cage may then be filled with a composition including bone growth material, bone cement, bone particles, and other structural or pharmaceutical components, alone or in combination. In the alternative, the interior of the cage may be filled with the desired material before insertion into the patient. In the final position, the bone growth material is in contact with the end plates of the vertebrae through the large openings on both sides of the implant.
[0037] FIG. 4 illustrates another embodiment of the cage which may have a rectilinear shape and radiopaque markers useful during the surgical implantation to locate the forward and rear ends of the cage in relation to the spine for proper placement of the cage. The end walls 14 and 15 each have an opening 61 connecting to a bore 63 along one edge, respectively. Radiopqaue rods 64 and 65 are secured in the bores. During the surgical procedure of implantation, the proper positioning of the implant may be monitored by flouroscope.
[0038] With regards to the rotation, the peripheral surfaces of the sidewalls 12 and 16 on top 11 and bottom 13 portion of the cage 10 alternatively includes recesses. FIG. 5 shows first recess 80 and second recess 81 . First recess 80 , is located on the top portion 11 of the cage 10 and is preferably cut into the exterior surface of the peripheral sidewall 16 . The first recess 80 extends from substantially the small end 14 to substantially the large end 15 . The second recess 81 is an inverse mirror image of the first recess 80 except on the second recess 81 is located on the bottom portion 13 of the cage 10 . More specifically, each recess 80 and 81 includes a pair of opposing faces, defining a carved out open area 82 there between. Because the first recess 80 and the second recess 81 is carved out within the hollow opening 30 the surface area of the opening 82 contains a hollow opening to promote boney in growth, vascularization and fusion of the adjacent vertebrae. The opening 82 may be of a concave, convex, or planar shape. The edge of the recesses preferably slope at an angle of 45 degrees from the centerline CL of the cage, however, it is contemplated that the recesses may vary in angle from 1 degree to 89 degrees from the centerline CL. The recesses are designed to help aid in rotation of the cage. The amount of surface area in contact with the top vertebrae during rotation is decreased with the grooves thus reducing the frictional forces working against the rotation and making the rotation easier. In addition, the spaced traversed between adjacent vertebrae is reduced as the cage is rotated into position thereby minimizing the stress applied to the vertebrae.
[0039] FIG. 6 shows a top view of spinal cage 10 illustrating the groove 81 on elongated side wall 12 .
[0040] FIG. 7 shows a side view of spinal cage 10 illustrating groove 81 and opening 82 on elongated side wall 12 .
[0041] FIG. 8 shows a partially exploded perspective view of the spinal cage 10 with groove 80 on elongated side wall 16 further including radiopqaue markers 64 and 65 .
[0042] FIGS. 9 through 14 show an alternative embodiment with a stop-plate 90 and 91 on the top portion 11 and bottom portion 13 of the cage 10 , specifically the elongated sidewall 12 and elongated sidewall 16 towards the larger end wall 15 , respectively. The stop-plate is configured to make contact with the top vertebrae and act as a guide to prevent from over rotation of the cage 10 . Because the desired rotation of the cage 10 is 90 degrees the stop-plates 90 and 91 are oriented at right angles from the top portion 11 to prevent over rotation. The body of the stop-plates 90 and 91 are sloped, having a concave cross-section to promote easy transition when the cage is manipulated into position with sidewalls parallel to the longitudinal axis of the spine. Stop plates 90 and 91 can likewise be incorporated to each of the spinal cages 10 previously described. In this embodiment the cage 10 includes a bridging element 70 located on the top portion 11 and bridging element 72 located on the bottom portion 13 . Bridging element 70 , located on the top portion 11 , traverses the hollow interior 30 and extends in a diagonal fashion from end 14 adjacent side wall 12 to end wall 15 adjacent side wall 16 , as shown in FIG. 9 . Bridging element 72 , located on the bottom portion 13 , traverses hollow interior 30 and extends in a diagonal fashion from end 14 adjacent side wall 16 to end wall 15 adjacent side wall 12 , as shown in FIG. 15 . Bridge members 70 and 72 are each provided with teeth that are in alignment with the teeth formed on the top and bottom peripheries of the elongated side walls 12 and 16 . The profile of the teeth on the side walls 12 and 16 and bridging elements 70 and 72 that are in alignment have identical profiles.
[0043] The cage 10 may be constructed as a molded, cast or machined unitary structure or as a construct of components. The end walls and the sidewalls may be separate elements connected together by welding, adhesives, heat and pressure, or other fastening. The teeth may be integral with the sidewalls or separate pieces attached to the periphery of the sidewalls.
[0044] A number of embodiments of the present invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the invention is not to be limited by the specific illustrated embodiment but only by the scope of the appended claims.
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A spinal implant for insertion in the intervertebral space is formed as a hollow cage, wedge shaped in profile, with a lesser height leading end for a low profile entry. The cage has two open sides with a plurality of angled teeth along opposite longitudinal edges for engaging the end plates of adjacent vertebrae when the cage is rotated into position. One portion of the angled teeth is angled toward an end of the cage and another portion of the angled teeth is angled away from that end to provide a lock preventing the cage from migrating ventrally or dorsally from the spine. Upon rotation, the leading end has a greater height than the trailing end. Opposing side walls of the cage include recesses to facilitate rotation of the cage and minimize stress on adjacent vertebrae.
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FIELD OF THE INVENTION
[0001] The present invention relates to human medical treatment by aerosol inhalation of immunoglobulin (Ig) A. More specifically the invention relates to treatment of immunodeficiencies and viral or bacterial infections of the lower respiratory tract by administering doses of IgA or an antibody composition rich in immunoglobulin A.
BACKGROUND OF THE INVENTION
[0002] Immunoglobulins (also called antibodies) are a group of structurally related proteins composed of heavy and light chains. These proteins are categorized as IgM, IgG, IgD, IgE, and IgA depending upon the characteristics of the constant regions of their heavy chains (designated μ, γ, δ, ε, and α, respectively). The variable regions of the heavy chains along with the variable regions of the light chains determine the molecular (antibody) specificity of the complete molecule. These molecules are secreted by B lymphocytes in response to signals from other components of the immune system. Their function is to prevent and combat infection by viruses and bacteria.
[0003] Purified IgG from pooled human plasma is administered intravenously in humans to treat a variety of conditions. In the purification, a fraction rich in IgA is considered an unwanted by-product, since intravenous administration of IgA containing immunoglobulin can cause life threatening anaphylaxis in some patents.
[0004] IgA on mucosal surfaces is produced locally and not derived from circulating IgA. IgA is one of the γ globulins on the basis of its electrophoretic mobility. IgA is composed of two α heavy chains and two light chains. It may be monomeric (i.e. a single molecule), dimeric (composed of two molecules) or trimeric (composed of three molecules). IgA monomers are joined together as dimers at the constant regions of their heavy chains by a J chain. IgA is secreted as one of two subclasses, IgA1 and IgA2. IgA1 predominates in the circulating blood wherein most of it occurs as a monomer. Most IgA on mucosal surfaces, such as the surfaces of the trachea, bronchi, and bronchioles in the lungs, occurs as dimers or trimers joined by J chains. IgA dimers and trimers have an increased ability to bind to and agglutinate target molecules (antigens). Agglutinated antigens are more readily phagocytosed and thereby eliminated. In addition, IgA dimers and trimers, because of the presence of their J chains, have the ability to attach to secretory component. Such molecules then have increased resistance to proteolytic enzymatic degradation. Human J chains (Symerski, et al., Mol Immunol 2000; 37:133-140) and murine secretory component (Crottet, et al., Biochem J 1999; 341:299-306) have been produced by genetic recombinant biological techniques. Recombinant expression of polymeric IgA with the incorporation of J chain and secretory component of human origin has been accomplished (Johansen, et al., Eur J Immunol 1999; 29:1701-1708)
[0005] IgA can attach to the cell surface of phagocytic leukocytes and thereby facilitate antibody-dependent cell-mediated killing of microorganisms. It also interacts with lactoperoxidase and lactoferrin which enhances the latter's antibacterial actions. Monomeric IgA interferes with influenza virus replication (Taylor, et al., J Exp Med 1985;161:198-209) and polymeric IgA interferes with influenza binding to and entry into target cells (Taylor, et al., J Exp Med 1985;161:198-209; Outlaw and Dimmock, J Gen Virol 1990;71:69-76).
[0006] Exogenous IgA has been topically applied to the nose in both animals and humans for the purpose of preventing and treating disease. In mice, nasal application of exogenous IgA has been demonstrated to be efficacious in protecting animals from influenza (Tamura, et al., Vaccine 1990;8:479-485, Tamura, et al., Eur J Immunol 1991;21:1337-1344), Sendai virus (Mazanec, et al., J Virol 1987;61:2624-2626, Mazanec, et al., Virus Res 1992;23:1-12) and respiratory syncytial virus (Weltzin, et al., Antimicrob Agents Chemother 1994;38;2785-2791) challenge. Intranasal monoclonal IgA also protects rhesus monkeys against respiratory syncytial virus infection (Weltzin, et al., J Infect Dis 1996;174:256-261). In humans, nasal administration of approximately 70% IgA/30% IgG resulted in decreased frequency of upper respiratory tract infections in elite skiers (Hemmingsson and Hammarstrom, Scand J Infect Dis 1993;25:73-75), and in children (Giraudi, et al., nt J Pediatr Otorhinolarynol 1997;39:103-110, Heikkinen, et al., Pediatr Infect Dis J 1998;17:367-372) but not in elite canoeists (Lindberg and Berglund, Int J Sports Med 1996;17:2335-238).
[0007] Aerosol administration of human γ globulin (Fruchtman, et al., Clin Med 1972 (September);79:17-20), pooled human IgG (Rimensberger and Schaad, Pediatr Infect Dis J 1994;13:328-330) and murine recombinant humanized IgG (Fahy, et al., Am J Respir Crit Care Med 1999; 160:1023-1027) demonstrated that there are no adverse effects from the aerosol inhalation of human 65 globulin or human or humanized IgG.
[0008] Individuals suffering from hypogammaglobulinemia or with bronchial infections from other sources have been treated by a number of means, none of which has proven to be completely satisfactory. On the one hand, such patients have been treated by administration of antibiotics. However, antibiotics treatment is not completely effective in preventing infection in patients with immunoglobulin deficiency or whose immune systems are otherwise compromised. Another method of treating such patients has been intravenous infusion of immunoglobulin. The immunoglobulin administered by intravenous infusion does not contain the secretory piece. As a result, the infused immunoglobulin may not reach the mucosal surface of the bronchial tree. In addition, intravenous infusion of immunoglobulin is usually administered by trained medical personnel and can be associated with systemic reactions. There is thus a need for methods which can be used to deliver IgA to the bronchial mucosal surface. It would be advantageous if such treatment could be administered by the patient without the need for intervention by trained medical personnel. It would further be desirable to make use of unwanted by-products resulting from the preparation of purified immunoglobulin G from pooled human plasma. The present invention provides these advantages and others as will be apparent to one with skill in the art from the disclosure that follows.
SUMMARY OF THE INVENTION
[0009] The invention provides a method for medical treatment of humans that involves pulmonary administration by inhalation of an immunoglobulin (Ig) A composition. In one embodiment, the IgA is prepared as a by-product from pooled human plasma and is derived from a Cohn fraction component enriched in IgA. In another embodiment, the IgA composition contains a monoclonal antigen-specific IgA. In a preferred embodiment, the IgA component is further combined with recombinant human J chains and recombinant secretory component to produce a more physiologically effective composition. Conditions treatable by pulmonary administration of such compositions include immunodeficient diseases, immune suppression, bacterial infections, and viral infections.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0010] The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
[0011] In one embodiment, the invention provides a method for medical treatment of humans comprising the step of administering by inhalation an aerosol composition. The aerosol composition contains an IgA component which can be derived from a number of sources. The aerosol composition contains an IgA component which can be derived from a number of sources. The by-product is obtained from pooled human plasma following Cohn cold ethanol fractionation to produce fraction III precipitate as performed by those of skill in the art of protein separation. IgA by-product is further purified by adsorption onto a ion exchange medium in neutral or slightly acidic conditions as performed by those of skill in the art of protein purification.
[0012] A more detailed description of isolation of an IgA component as a by-product from pooled human plasma or hyperimmune pooled human plasma is as follows. Ethanol fractionation of pooled human plasma is a well known process to prepare immunoglobulin G. Pooled human plasma is first obtained from licensed plasmapheresis centers in the United States and tested for various pathogens including the HIV virus. The first manufacturing step of most commercial immunoglobulin G preparations involves a modified cold ethanol fractionation according to Cohn to produce Cohn fraction II. In the fractionation process, many infectious viruses are eliminated from the pooled human plasma. Following fractionation, the Cohn fraction II is subjected to adsorption onto an ion exchange medium. This step may selectively reduce the IgA concentration to less than 0.1%. Such a step is important for producing immunoglobulin G for intravenous infusion into humans. This is because some individuals undergo an anaphylactic-like reaction if treated with intravenous IgG that contains IgA as an impurity.
[0013] The modified cold ethanol fractionation process according to Cohn is a series of fractionations using various levels of ethanol, pH, and temperature to produce a fraction II which is further treated to produce immunoglobulins as described above. In the fractionation method, pooled human plasma is first treated to produce a cryoprecipitate and cryo-supernatant. The cryo-supernatant is subjected to a first ethanol fractionation to yield a supernatant I. Supernatant I is subjected to a second ethanol fractionation to yield fraction II+III. Fraction II+III is subjected to a third ethanol fractionation procedure to yield a supernatant III and Fraction III precipitate.
[0014] The fraction III precipitate enriched in IgA is generally discarded as an unwanted by-product. According to the invention, this unwanted IgA following ion exchange adsorption purification, is further treated by incubation with immobilized hydrolases to inactivate viruses and vasoactive substances. Such treatment has been proven to eliminate many viruses tested including HIV, Sindbis, and vaccinia. Following incubation to remove viruses, the concentration of the active material is adjusted with sterile saline or buffered solutions to ensure a constant amount of active material per milliliter of reconstituted product. Finally, the solution with a constant amount of reconstituted product is sterilized by filtration before use.
[0015] The ethanol fractionation process according to Cohn is well known in the art and is described in Cohn, et al., J Am Chem Soc 1946;68:459-475, Oncley, et al., J Am Chem Soc 1949;71:541-550, and in most detail in pages 576-602, Kirk-Othmer Encyclopedia of Chemical Technology, Vol 3, second edition (1963), the disclosure of which is hereby expressly incorporated by reference.
[0016] In a preferred embodiment, the compositions of the invention contain, in addition to the IgA component, one or more further components selected from the group consisting of recombinant human J chains, recombinant secretory component, and combinations thereof. The production of human J chains by genetically recombinant biological techniques is disclosed in Symerski, et al., Mol Immunol 2000; 37:133-140, the disclosure of which is hereby incorporated by reference. Human secretory component can be produced by recombinant techniques as described in Crottet, et al., Biochem J 1999; 341:299-306, disclosure of which is hereby incorporated by reference. In a preferred embodiment the IgA may be coupled to recombinant J chains by disulfide bonding which is accomplished in mildly oxidizing conditions. The resulting IgA-J chain conjugates are purified. IgA-J chain conjugates may then be further coupled to recombinant secretory component. In a preferred embodiment, the coupling is accomplished by forming disulfide bonds under mildly oxidizing conditions. IgA containing both J chain and secretory component is again purified by ion-exchange and size exclusion chromatography and/or ultrafiltration as described in Lullau, et al., J. Biol Chem 1996; 271:16300-16309, Corthesy, Biochem Soc Trans 1997; 25:471-475, and Crottet, et al., Biochem J 1999; 341:299-306, as performed by those of skill in the art of protein purification, the disclosures of which are hereby incorporated by reference. While recombinant expression of IgA with the incorporation of J chain and secretory component has been accomplished, hybridoma production of IgA may not include incorporated J chains and secretory component. According to the invention, the recombinant J chains, recombinant secretory component, or mixtures of them may be combined with the monoclonal IgA after production of the IgA by hybridoma techniques. Such IgA may be coupled to recombinant J chains and secretory component as described above. Purified IgA containing J chain and secretory components can be stabilized for example by the addition of human serum albumin to a final concentration of 5%. The presence of the human J chains and secretory component in the compositions of the invention leads to inhaled doses of immunoglobulin which are more physiologically effective than compositions without such components.
[0017] In another embodiment, an IgA containing component is isolated as a by-product from hyperimmune pooled human plasma for coupling with J chain and secretory component. Hyperimmune pooled human plasma is obtained from donors who have been immunized against a specific disease.
[0018] In another embodiment, the IgA component can be prepared by hybridoma techniques to provide antigen-specific IgA. Hybridoma techniques are described originally in Kohler and Milstein, Nature 1975;256:495-497 with more recent advances summarized in Berzofsky et al., Fundamental Immunology, Third Edition, 1993, pp 455-462, the disclosures of which are hereby incorporated by reference. Hybridoma production involves the fusion of an immortalized immunoglobulin-producing myeloma cell with an antibody-producing cell from an immunized individual. The product is an immortalized cell culture which produces the specific antibody against the antigen that the donor individual is immune to. For example, a mouse monoclonal IgA antibody has been prepared against respiratory syncytial virus F glycoprotein as described in Weltzin, et al., J Infect Dis 1996;174:256-261 and Weltzin, et al., Antimicrob Agents Chemother 1994;38:2785-2791.
[0019] The compositions of the invention for pulmonary delivery of aerosol compositions generally contain in addition to the IgA component and optional J chains and secretory component known pharmaceutical excipients and buffering agents. Non-limiting examples of such excipients include proteins as for example, human serum albumin and recombinant human albumin. Other pharmaceutical excipients include carbohydrates, sugars, and alditols. Non-limiting examples of suitable carbohydrates include sucrose, lactose, raffinose, and trehalose. Suitable alditols include mannitol, and pyranosyl sorbitol. Polymeric excipients include polyvinylpyrolidone, Ficolls, soluble hydroxyethyl starch, and the like of suitable molecular weight. Non-limiting examples of suitable buffering agents include salts prepared from organic acids such as citric acid, glycine, tartaric acid, lactic acid, and the like. Other useful excipients include surfactants and chelating agents. The compositions of the invention are readily aerosolized and rapidly deposited in the lungs of a host. Doses are formulated from the compositions of the invention by combining the IgA component with or without human J chain and secretory component, and pharmaceutical excipients so as to contain an effective dose of the active ingredient. A typical dose would include about 5 milligrams of active material. The dose amount may be adjusted up or down as required to meet the treatment needs of an individual, or to provide for ease and convenience in administering the dose.
[0020] The compositions of the invention can be administered by nebulization or by metered dose inhalers. Nebulizers and metered dose inhalers are well know in the art and are described for example, in Wolff and Niven, J Aerosol Med 1994;7:89-106.
[0021] Diseases and conditions for which aerosol pulmonary administration of the compositions of the invention is to be used therapeutically or prophylactically include, but are not limited to: common variable immunodeficiency, IgA deficiency, human immunodeficiency virus (HIV) infection, lower respiratory tract infection with influenza, lower respiratory tract infection with respiratory syncytial virus, lower respiratory tract infection with rhinovirus, lower respiratory tract infection with adenovirus, chronic lymphocytic leukemia, multiple myeloma, macroglobulinemia, chronic bronchitis, bronchiectasis, asthma, immune suppression associated with bone marrow transplantation, immune suppression associated with cyclophosphamide administration, immune suppression associated with azathiaprine administration, immune suppression associated with methotrexate administration, immune suppression associated with chlorambucil administration, immune suppression associated with nitrogen mustard administration, immune suppression associated with 6-mercaptopurine administration, immune suppression associated with thioguanine administration, severe combined immunodeficiency, adenosine deaminase deficiency, major histocompatibility class I (Bare leukocyte syndrome) and class II deficiencies, purine nucleoside phosphorylase deficiency, DiGeorge Syndrome, transient hypogammaglobulinemia of infancy, X-linked agammaglobulinemia, X-linked agammaglobulinemia with growth hormone deficiency, transcobalamin II deficiency, immunodeficiency with thymoma, immunodeficiency with hereditary defective response to Epstein Barr virus, immunoglobulin deficiency with increased IgM, κ chain deficiency, ataxiatelangiectasia, and immunodeficiency with partial albinism.
[0022] As used here, the term therapeutic treatment means that the patient being administered a dose of a composition of the invention has been diagnosed as having the condition to be treated. Prophylactic treatment means that the patient is being treated to prevent infection. Such treatment is often indicated where a patient is at risk for lower respiratory tract infection.
EXAMPLE
[0023] Polyclonal IgA is obtained from pooled human plasma following Cohn cold ethanol fractionation to produce fraction III precipitate. IgA is further purified by adsorption onto an ion exchange medium in neutral or slightly acidic conditions. Alternatively, monoclonal IgA is obtained from an IgA-producing hybridoma. The IgA is then coupled to recombinant J chains by disulfide bonding which is accomplished in mildly oxidizing conditions. The molar ratio of IgA to J chain is 2:1 or 3:1. IgA-J chain conjugates are purified. IgA-J chain conjugates may then be further coupled to recombinant secretory component again by disulfide bonding in mildly oxidizing conditions, preferably at a molar ratio of secretory component to IgA-J chain conjugates of 1:1. IgA containing both J chain and secretory component is again purified. Purified IgA containing J chain and secretory component is stabilized by the addition of human serum albumin to a final concentration of 5%. The final solution, adjusted to a therapeutic dose of 5 mg IgA, is then placed in a nebulizer for self-administration.
[0024] The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.
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Pooled human plasma is processed by cold ethanol fractionation to produce purified immunoglobulin G antibodies for intravenous administration. Immunoglobulin A is an unwanted by-product since intravenous administration of immunoglobulin A-containing immunoglobulin G can cause life-threatening anaphylaxis in some people. The present invention is the aerosol administration, by metered dose inhaler or nebulizer, of by-product immunoglobulin A for the prevention or treatment of diseases including immunodeficiencies and infections. Antigen-specific monoclonal immunoglobulin A may be used. Immunoglobulin A from any of the aforementioned sources may then be coupled with recombinant J chain, and may then be additionally coupled with recombinant secretory component in order to render the immunoglobulin A more physiologically active. Immunoglobulin A, with or without J chain and secretory component, is then administered by aerosol inhalation.
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BACKGROUND OF THE INVENTION
The present invention relates generally to rotating water feeds and more particularly to a ventilation system therefor. The invention is particularly useful in connection with water-cooled generators which preferably comprise coaxial feed and discharge ducts.
Prior to initiating operation of a rotating water feed, special attention must be paid to the elimination of air which may be enclosed in the cooling system in order to avoid undesired local overheating. Such overheating will give rise to several consequences including the formation of steam bubbles which may partly or possibly completely clog the respective cross sections of the flow paths involved. It is important for the proper ventilation of such a cooling system that not only stationary apparatus and auxiliary devices be ventilated, but rotating parts, particularly the water feeds, must also be ventilated. In the case of a rotating machine, it must be noted that the point of lowest pressure is usually at the axis of rotation. Consequently, any air or gas bubbles which remain in the circuit or which have entered through manipulation of the apparatus by operating personnel, will usually accumulate at this point. Despite the fact that these air bubbles will partially block the cross section of the flow paths involved and thereby reduce the efficiency of the cooling system practically no attention is paid to them. For example, in an article entitled "The Development of Water-Cooled Rotors for Large Turbogenerators" in "Technische Mitteilungen AEG Telefunken" 59 (1969), 1, there are described and represented only turbogenerators having no ventilation system.
In "AIEE Transactions" 1950, vol. 69, page 167-170, there are described and presented a few examples of water-cooled turborotors. In a stationary water feed pipe there is arranged a long, thin pipe extending in the axis of rotation. One end of the pipe is located in the branch point of the cooling water connections and the other end extends to the exterior of the machine. This solution, however, has been found to require considerable engineering effort due to the fact that these feeds must involve a great length in most of the cases where they are used.
Accordingly, it is an object of the present invention to provide an arrangement which avoids disadvantages of prior art techniques and which permits automatic removal, or reduction thereof to a tolerable extent, of air or gas bubbles accumulating in rotating pipes such as water feeds of water-cooled generators. It is also an aim of the invention to formulate a structural arrangement which is as simple in design as possible.
SUMMARY OF THE INVENTION
Briefly, the problems discussed above are solved by the present invention in a device of the aforementioned type by providing at least one bypass having at least one inlet and at least one outlet arranged between the feed duct and the discharge duct of the apparatus with the bypass having at least one inlet which opens into the space around the axis of rotation of the apparatus.
The advantages of the invention arise particularly because of the fact that by virtue of the aforementioned arrangement all bubbles will be rapidly and completely removed by utilizing the pressure gradient between the inflow and outflow for automatic operation of the device. Furthermore, the invention provides a ventilation system which is relatively simple in its design and construction.
In accordance with a preferred embodiment of the invention, the bypass is arranged in or on an end face of the feed ducts. This solution is of particular advantage if the branch point is at the end of the feed duct, because this point is usually the last point to which bubbles will be carried by a rotating rotor. If cooling water inlets are distributed over the entire length of a central bore, it is advantageous if the bypass is designed as a radially arranged pipe member with at least one inlet in the space around the axis of rotation. Of course, it is also possible to provide several bypasses in accordance with the structural solution of the present invention.
In accordance with a further embodiment of the invention, the bypass may be designed as a coiled pipe having at least one inlet opening into the space around the axis of rotation. This form of construction affords advantages in that it permits the amount of leakage and bypass to be minimized by simple technical means.
According to a preferred embodiment of the invention, the bypass is structured to include means for increasing the hydrodynamic resistance of flow through the bypass. Such an arrangement enables the achievement of an adequate pressure drop over a short distance with a low resistance to flow and, accordingly, a ventilation system having smaller outer dimensions may be provided.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there are illustrated and described preferred embodiments of the invention.
DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a schematic view partially in section depicting a first embodiment of the invention wherein the bypass means is arranged in the end face of the feed pipe;
FIG. 2 is a schematic view partially in section showing a second embodiment of the invention wherein the bypass is arranged in the end face of the feed pipe;
FIG. 3 depicts a third embodiment of the invention wherein the bypass is designed as a radially arranged pipe;
FIG. 4 shows a fourth embodiment of the invention wherein the bypass in again designed as a radial pipe; and
FIG. 5 depicts a fifth embodiment of the invention wherein the bypass is in the form of a coiled pipe.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, wherein like reference numerals refer to similar parts throughout the various figures thereof, there is depicted in FIG. 1 a ventilation system for a rotating water feed which comprises an axial feed duct 1, defined by an inner pipe 2 having an end face 3. An axial discharge duct 4 is defined by an outer or outlet pipe 5 having an end face 6. The system includes a radial feed duct 7 defined by a radial feed pipe 8 with radial discharge ducts 9 being defined by radial discharge pipes 10. The bypass means of the invention are embodied in a bypass 11 which includes an inlet 11' and an outlet 11". The system defines an axis of rotation designated 19 and the arrows shown in the drawing depict the directions of flow, with the smaller arrows representing the flow which occurs through the bypasses.
In FIG. 2 a second embodiment of the invention is depicted as comprising a bypass member 12 having an inlet 12' and outlets 12".
In FIG. 3 the bypass is shown at 13 with an inlet 13' and with outlets 13". The pipe member forming the bypass 13 is shown at 16 and includes an insert 17 having a spiral groove provided therein in order to form through the bypass a spiral flow path.
In FIG. 4, the bypass means is identified as a bypass 14 having an inlet 14' and outlets 14".
In accordance with FIG. 5, the bypass is designated 15 and it includes an inlet 15' and an outlet 15".
As shown in FIG. 1, the inner pipe 2 forming the axial feed duct 1 is provided with an end face 3. Adjacent the end face 3 there are arranged the radial feed ducts 7 which are formed by the radial feed pipes 8. The bypass 11 is arranged on the axis of rotation 19 with its outlet 11" opening into the axial feed duct 4. As a result of the different pressures occurring in the feed duct 1 and in the discharge duct 4, air bubbles accumulating around the axis of rotation 19 will be transported through the bypass 11 into the discharge duct 4.
FIG. 2 depicts a similar arrangement of feed duct and discharge duct with the bypass 12, however, being designed in the form of a T-pipe. The radially extending portions of the T-pipe of the bypass 12 are formed to be longer than the diameter of the inner pipe 2 and as a result the outlets 12" of the bypass 12 will open into the discharge duct 4 in the direction of flow.
FIG. 3 depicts a bypass 13 which is designed as a radially arranged pipe 16. The inlet opening 13 is again located in the space around the axis of rotation 19 and the outlets 13' open into the discharge duct 4 in the direction of flow. In order to increase the hydrodynamic resistance within the bypass, the pipe 16 includes the insert 17 having a spiral groove 18. This creates a throttling effect and the throttling device shown serves to minimize the amount of bypass flow.
The bypass 14 shown in FIG. 4 involves essentially the same design as the bypass 13 depicted in FIG. 3. However, in FIG. 4 the bypass 14 is arranged at any desired point of the inner pipe 2, this arrangement being suitable for a case where several radial feed ducts 7 open into the axial feed duct 1. In this embodiment it is possible to arrange several bypasses 14 in the inner pipe 2.
The embodiment of FIG. 5 depicts another structural arrangement for the feed duct 1 and the discharge duct 4. In the embodiment of FIG. 5, the bypass 15 is arranged at one end of the outer pipe 5. The bypass is designed in the form of a coiled pipe having its inlet 15' opening once again into the space around the axis of rotation 19. The bypass 15 may, of course, be provided with several inlets 15'. The spiral pipe of the bypass 15 is rather long and thus it will inherently act as a throttle. Of course, the bypass 15 can also be arranged in any cross section of the inner pipe 2 but it may, as a result, reduce the useful flow cross section of the pipe 2.
With the ventilation system in accordance with the present invention as described above, there will result elimination of any air or gas bubbles that may be formed because the inlet openings are provided in the space around the axis of rotation 19 where the arriving air bubbles accumulate because of the existance of a lowest pressure point. Thus, the inlet of the bypass is advantageously arranged and enables bypass flow in a desired manner in order to achieve the advantageous ventilating effects of the invention.
While specific embodiments of the invention have been show and described in detail to illustrate the application of the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.
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A ventilation system for rotating water feeds particularly useful in water-cooled generators is equipped with bypass means arranged to extend between coaxial feed duct means and discharge duct means defining a centrally located axis of rotation. The bypass means includes at least one inlet which is located to open in the space around the axis of rotation with outlet means of the bypass means opening into the discharge duct means to vent air or gas bubbles.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a pressurized device for the dispensing of liquid or creamy products, for example, cosmetic, food or pharmaceutical products. 2. Description of the Related Art A conventional pressurized device is constituted by a container body on which a lid is optionally fitted. A valve is crimped on the neck of the container by means of a valve carrier cup. A dispensing means is connected to the valve. The container body and the cup define a reservoir cavity. The valve is constituted by a valve body, a valve actuating stem that passes through the valve body, a gasket, and a restoring system that applies the valve actuating stem against the gasket, the unit being kept in position by the crimping of the valve carrier cup. The valve actuating stem is surmounted by a push button. A product to be dispensed and a propellant are disposed in the reservoir cavity.
The propellant may be a compressed gas directly in contact with the product in the container body. In this case, a dip tube element is fixed to the valve. When it is not desirable for the product to be in contact with the gas, provision may be also made for separating the gas and the product by a flexible pouch or by a piston. In the case of the flexible pouch, problems frequently arise concerning compatibility with the formula and strength the material constituting the pouch which must be flexible and leakproof In the case where a piston is used for separating the gas from the product, there arise sealing problems along the contact surfaces between the piston and the internal wall of the container body.
Moreover, in these two cases, the fill opening for the gas must be distinct from that for the formula: filling with gas is frequently undertaken through an opening situated at the bottom of the container, obturated by a rubber stopper. This configuration requires repetitive actions during manufacture: opening the gas fill opening, positioning the pouch or the piston, and positioning the stopper. It is also expensive because of the complexity of the filling process: feeding first the product and then the gas.
Moreover, from EP-A-0561292, dispensing devices are known which use as the propellant a cellular material with closed cells. A gas is trapped in the cells of the cellular material. This document describes devices in which the product is placed into a flexible bottle inside the container body. The cellular material is placed into this container body in contact with, and outside, the flexible bottle. The cellular material is connected to a knurled wheel. Before actuating the valve by means of a push button, the user must store energy in the cellular material by actuating the knurled wheel. The gas contained in the cellular material is then subjected to mechanical pressure and transmits this pressure to the bottle and its contents: by actuating the valve, the product can then be dispensed.
However, such a device has several drawbacks: this device has a large number of parts. These parts require very fine adjustment (screw threads, seal) and are sophisticated. As a result, this device is very expensive. The storage of energy by mechanical compression of the cellular material is effected in small quantities: before actuating the push button, the user must turn the knurled wheel to store the energy corresponding to approximately one application dose. The need for this double action renders the device complicated and unattractive for a consumer in a hurry. The bottle wherein the product is contained has the shape of a bellows. Thus, even if it is compressed to a maximum by the action of the cellular material, this bottle cannot be completely emptied and a low recovery rate is obtained.
When the user stores energy in the cellular material by turning the knurled wheel, he creates a strong osmotic pressure on either side of the bottle. Thus the wall of this bottle, subjected to a to and fro motion by the mechanical action of the celular material, becomes fragile by frequent use. With this device, as in the case where a flexible pouch is used for separating a gas from the product, the same problem of compatibility of the product with the wall of the bottle is encountered. Moreover, if the user inadvertently exerts too powerful an action on the knurled wheel, he subjects the cellular material to a pressure which causes the cells containing the gas to burst, and irreversibly damages the device. Finally, such a device does not allow the bottle to be refilled with the product by means of the valve by pressurizing the cellular material since, by this mechanical compression, one would also obtain a bursting of the cells and would thus render the device no longer usable.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a pressurized device which overcomes the aforementioned problems.
It is a further object of the invention to provide a pressurized device using as the propellant an element of a cellular material with closed cells.
In order to achieve the above and other objects, the invention provides a pressurized device for the dispensing of a product, comprising a reservoir cavity; a longitudinal axis; a valve positioned at the top of the reservoir cavity and a dispensing means connected to the valve; and a pressurizing means constituted by an element of closed cell cellular material. The element of cellular material and the product are placed together inside the reservoir cavity and are subjected to a permanent and uniform pressure, so that the device dispenses the product when the valve is actuated. The element of cellular material comprises at least one slit at its circumference over its whole height measured along the longitudinal axis.
In accordance with the invention, the shape of the element of a cellular material is defined before it is introduced into the reservoir cavity.
Although the invention is particularly suitable for a pressurized device wherein the element of a cellular material and the product are subjected to a permanent and uniform pressure, it applies to any type of product dispenser.
"Peripheral" is understood to mean a slit having one end situated at the periphery of the element of a cellular material. A peripheral slit opens the element of the cellular material towards the outside.
The devices in accordance with the invention make it possible to dispense all kinds of products in solution, emulsion or gel form: lotions, creams, self-foaming compositions, milks or gels. Such a device makes it possible to avoid the mixing of gas with the product to be dispensed and to avoid gas leaks. Thus the duration of use of the device is extended. According to the nature of the cellular material and the size of the element of the cellular material, the pressure inside the device can be adapted to the viscosity of the product to be dispensed. Such a device allows a product to be pressurized without the risk of the product being polluted by the gas and without polluting the atmosphere. Moreover, this device only comprises a small number of conventional mechanical parts and its manufacture is simple. It is therefore inexpensive and simple to use. The device is not fragile and does not involve the risk of the cells bursting due to improper use. Finally, since the compression means is retained inside the device after all of the product has been recovered, it can be refilled and reused several times. Such a device thus makes it possible to obtain a saving in the cost of packaging and permits its eventual reprocessing.
Moreover, a device in accordance with the invention makes it possible to obtain a recovery rate of the product of the order of 95%.
A cellular material usable in the present invention is constituted by a multitude of cells filled with gas enclosed in a deformable matrix such as, for example, a foam of a polyolefin, an elastomer or any type of thermoplastic material; a foam of rubber, Buna, neoprene, silicone or any other material. The gas may be any gas compressible or liquefiable at the usual pressures as, for instance, nitrogen or simply air.
When the cellular material is compressed, the cells are also compressed; they thus store a reserve of energy for pressurizing the product. When the valve of the pressurized device is actuated, the cells expand and the product is restored.
The gas present in the cells is retained therein and cannot escape from them. Thus the problems of leakages and mixing with the product are avoided.
Advantageously, the element of cellular material used as the pressurizing means in the devices in accordance with the invention has a shape complementary to that of the reservoir cavity, and preferably it is chosen to have an overall cylindrical shape.
The element of cellular material can be made in any known way by extrusion or by cutting from a block of cellular material with closed cells. To cut out a cylinder of cellular material, one is obliged to compress it before the cutting. After the cutting and decompression, an element of cellular material is obtained with this method with slightly concave lateral contours, as described in EP-A-0561292. When such an element without a slit at its circumference is positioned in a device such as described above, some of the product will be accommodated between the concavity of the element of the cellular material and the walls of the container. Thus one obtains a recovery rate that is lower than that which can be obtained with a cylinder with perfectly straight contours. However, a cylinder of cellular material cut out from a large-sized block is less expensive than a cylinder of an extruded cellular material. For economic reasons, it is therefore desirable that one should be able to use in the pressurized devices an element of cellular material that is cut out rather than extruded, while retaining a satisfactory recovery rate.
The element of cellular material used in the present invention can be extruded or even cut out. Indeed, the slit permits a wider expansion of the element of cellular material; this expansion compensates the concavity of the cut-out elements of the cellular material. One can thus obtain an almost complete recovery of the product with a cut-out element of cellular material. However, a cut-out element of cellular material has open cells on its contours, while an extruded element has no open cells. An element of cellular material obtained by extrusion is therefore preferable.
Preferably, the element of cellular material has larger dimensions (height, diameter) than those of the reservoir cavity, in such a way that when the reservoir cavity is closed, a precompression of the element of the cellular material is obtained so as to have energy still available when little of the product remains in the device.
In accordance with the invention, the slit is preferably radial relative to the cylinder of the cellular material.
The element of cellular material may optionally have a central opening over its whole height. When the cylinder of cellular material does not have a central opening, the slit is advantageously cut over the whole height of the cylinder of the cellular material and over a width substantially equal to the radius of the cylinder of the cellular material. When a central opening is provided, this may constitute a recess for a dip tube element connected to the valve.
When the device does not have a dip element, it may be advantageous to provide a central opening in the element of cellular material: indeed, on assembly of the device, the element of cellular material is introduced into the reservoir cavity. The element of cellular material usually has a height greater than or equal to the height of the reservoir cavity. When the valve is positioned at the top of the reservoir cavity, for instance when the valve is crimped by means of a valve carrier cup to the top of the container body whose walls define the reservoir cavity, the valve exerts a mechanical compression on the top of the element of cellular material. The cells subjected to the compression burst and the element of cellular material is deformed in its upper portion. Some product may subsequently come to be accommodated in this deformation. Gas is diffused into the reservoir cavity and will mix with the product. To avoid these drawbacks, a central opening may be provided in the element of cellular material into which the valve can be introduced, even when the device does not have a dip tube element.
According to a preferred embodiment of the invention, the slit is associated with a central opening over the whole height of the element of cellular material. The slit is capable of opening the cylinder from its external surface as far as its central opening. It may instead be shallow, that is, not extend as far as the central opening. The element of cellular material has, moreover, a slit extending from its external surface as far as its central opening. Preferably, it has a slit extending from its external surface as far as its central opening. It may have several shallow slits. When the device does not have a dip tube element, the central opening preferably has an elongate shape and is orientated in the extension of the slit.
According to a first variant of the invention, when the device has a dip tube element, the cylinder of cellular material, having a slit which extends from the external surface as far as its central opening, may be constituted by a small piece of cellular material in a rectangular shape which is wrapped round the dip tube element. Indeed, the manufacture of small pieces of cellular material of a rectangular shape is more easily obtained and therefore more economic than that of a cylinder wherein a central opening, and then a slit, are cut out.
The device in accordance with the invention may, in the known way, include a container body defining the reservoir cavity, a valve which comprises a valve body separate from the container body and is positioned at the top of the reservoir cavity, a dispensing means connected to the valve and a pressurizing means constituted by an element of closed cell cellular material, the element of cellular material and the product being placed inside the reservoir cavity and being subjected to a permanent and uniform pressure so that the device dispenses the product when the valve is actuated.
The device in accordance with the invention may be provided with a valve made of an elastomeric material having catch engagement means capable of cooperating with the neck of the container body, as described in the French patent application FR-A-2741933. The valve may be crimped to the neck of the container in the known way by means of a valve carrier cup, the container body and the cup defining the reservoir cavity.
In a second variant of the invention, the device has a cup, a valve provided with a valve body, a valve actuating stem which is optionally surmounted by a push button optionally comprising a dispensing means, a gasket and a restoring system, the cup and the valve body cooperating with each other so as to form a reservoir cavity capable of containing a product to be dispensed and a propellant means, and the valve body proper delimiting the cavity of the valve, a passage being arranged between the reservoir cavity and the cavity of the valve.
According to this variant, the valve body passes through the reservoir cavity over its whole height and forms a dip tube element. The cup and the valve body cooperate in a leakproof manner at their ends so as to form the body of the container. For example, the cup and the valve body have complementary fastening elements, for example, means capable of being catch engaged or complementary profiles which, once assembled, are welded together by any conventional means, for instance, rotational welding or bonding. The fastening elements may also consist of complementary threads, so that the valve body and the cup can be screwed onto one another in a leakproof manner.
To obtain this cooperation, a valve body may be chosen which has on its circumference the fastening elements and a cup having an external skirt that has at its end the fastening elements complementary to those of the valve body, this cooperation defining the body of the can. A cup may also be chosen which has on its circumference fastening elements and a valve body having an external skirt which has fastening elements at its end, complementary to those of the cup. A cup and a valve body may also be chosen which each have an external skirt, the two skirts having complementary fastening elements.
According to this variant, the valve body and the cup cooperate with each other so as to define a cavity inside the container, this cavity delimiting the valve. Preferentially, the valve body, and optionally the cup, each have an internal skirt. Advantageously, the internal skirts of the valve body and the cup are fitted into one another over the whole or part of their height, so as to delimit the cavity of the valve. Preferably, the internal diameter of the internal skirt of the cup is substantially equal to the external diameter of the internal skirt of the valve body. The upper surface of the internal skirt of the valve body advantageously bears on the gasket by applying it against the edge of the cup which surrounds the duct of the valve actuating stem. The seal of the valve is then ensured.
According to this variant, a passage is arranged between the reservoir cavity and the valve. Preferably, the internal skirts of the cup and of the valve body each have at least one notch, these notches being associated with a circular bevel of one or the other of the skirts along the circumference of the contact surface between the skirts, and optionally with a groove over the whole height of the contact surface between the skirts, the set of these cut outs (the groove, bevel, notches) defining the said passage for the product and possibly for the gas between the reservoir cavity and the cavity of the valve.
Advantageously, the valve body and the cup are made of a thermoplastic material. These two elements may be formed from the same material, or from two different chemically compatible materials, so as to allow them to be welded together, or of two chemically incompatible materials joined by screwing, bonding or catch engagement. Of the materials usable in the present invention, there may be mentioned, for example, the family of polyolefins, such as polypropylene, polyethylene and the copolymers of ethylene and of propylene, the family of polyacetals, such as polyoxyethylene; polyethylene terephthalate, methyl polymethacrylate may also be used; the polymer used in the invention may contain fillers such as silica, glass fibers or carbon fibers. The manufacture of these elements in other materials as, for example metal or glass, may be envisaged.
The thickness of the walls of the cup and of the valve carrier and in particular of the skirts, are adapted by the expert so as to withstand the pressure of the propellant means.
The valve actuating stem may be of any known type, for instance, an emergent stem or a female stem, irrespective as to whether they are of an axial displacement or a lateral displacement type, the latter valve type also being termed a "tilt" valve.
The restoring means may, in a known way, be a spring or any compressible or elastically deformable material which can be accommodated in the cavity of the valve.
Optionally, the cup may have a circular groove. The existence of this groove allows a push button of a standard format to be used, which comes to be positioned in the said groove. Moreover, this groove gives the cup greater strength.
The containers according to this variant of the invention are particularly advantageous when they are made in the form of aerosol containers for the sampling of one or more application doses of a product, since they remedy an absence of this type of packaging, satisfying the economic requirements of the market. However, their use is in no way limited to the dispensing of samples: the containers according to this variant of the invention may be obtained in formats of all sizes, in respect of which the expert will know how the nature and the thickness of the material should be adapted, so as to give the container the necessary strength.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
FIGS. 1A and 1B show longitudinal sections of a pressurized device having a cylinder of cellular material with closed cells as the propellant means before and after pressurization, this device being provided with a dip element;
FIGS. 2A and 3A respectively show two embodiments a cylinder of cellular material used in the present invention in cross-section, before being introduced into the reservoir cavity;
FIGS. 2B and 3B respectively show the two embodiments of FIGS. 2A and 3A installed in a container and correspond to section IIB--IIB of FIG. 1A;
FIGS. 2C and 3C respectively show the two embodiments of FIGS. 2A and 3A installed in a pressurized container and correspond to section IIC--IIC of FIG. 1B; and
FIGS. 4A, 4B and 4C respectively show a device according to a variant of the invention in a longitudinal section in the course of being assembled.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The device shown in FIGS. 1A and 1B has a container body 1 defining a reservoir cavity 1.1 with a longitudinal axis X--X. A lid (not shown) may be optionally fitted on this body. A valve 2 is crimped onto this container by means of a valve carrier cup 3. The valve is formed by a valve body 2.1, a valve actuating stem 2.2 which passes through the valve body, a gasket 2.3 and a spring 2.4 which applies the valve actuating stem 2.2 against the gasket 2.3, the unit being held in position by the crimping of the valve carrier cup 3. A dip tube 7 is fixed to the valve. Before the valve 2 is crimped onto the container body 1, a cylinder 5 of plastazote, namely a matrix of polyolefin and nitrogen, is introduced through the opening of the can.
FIG. 2A shows an element 25 of cellular material of a cylindrical shape, having a cylindrical opening 26 at its center and a radial slit 28 which extends from the outer surface of the cylinder as far as the opening 26. This corresponds to the cylinder 5 before it is introduced into the container body 1. FIG. 3A shows an element 35 of cellular material of a cylindrical shape, having an elongate central opening 36 which is substantially eye-shaped, and a slit 38 in the extension of the opening 36. This element may be used instead of the cylinder 25 in a device without a dip element.
In FIG. 2B, the cylinder 5 of cellular material with closed cells has been introduced into the container body 1. The outer diameter of the cylinder 5 is greater than the diameter of the reservoir cavity 1.1, so as to obtain a lateral precompression of the cellular material and produce sufficient energy for dispensing the dregs of the product. The dip tube 7 passes through a central cylindrical opening 6 in the cylinder 5.
The elements of FIG. 1B in common with FIG. 1A have the reference numerals of FIG. 1A increased by 10. The elements of FIG. 2C in common with FIG. 2B have the reference numerals of FIG. 2B increased by 10.
A device in accordance with the invention ready for use has been shown in FIGS. 1B and 2C. This device is distinguished from that shown in FIGS. 1A and 2B in that a product 19 has been introduced with force by means of the valve 12, which results in a lateral and longitudinal compression of the cylinder 15 of the cellular material. The compression is of the hydraulic type, that is to say, in three dimensions over the volume of the element 15 of cellular material. The internal diameter of the opening 16 is then slightly increased as compared with the diameter of the opening 6 shown in FIG. 1A, the edges of the slit 8 shown in FIG. 2B have diverged so as to form an opening 18. The cylinder 15 of cellular material is thus free for displacement along the dip tube 17 according to its relative density as compared with the product.
A push button 14 is positioned on the valve actuating stem 12.2. By actuating the push button 14, the valve 12 is opened, the cylinder 15 is dilated and ejects the product 19. When all the product 19 has been ejected from the device, the latter is again in the state shown in FIGS. 1A and 2B. Thanks to the slit, the cylinder consisting of cellular material is considerably expanded and the formation of zones retaining the product is avoided. This device can then be recharged with the product 19, as has been described above. Thus a saving is obtained in packaging and the problem of reprocessing pressurized devices is considerably reduced, since the same device can be reused many times.
The variant of the device in accordance with the invention shown in FIGS. 3A, 3B and 3C is distinguished from the device shown in FIGS. 1A, 1B and 2A, 2B and 2C by the absence of the dip tube in the cylinder of cellular material. However, this cylinder has an elongate, substantially eye-shaped central opening 36 and a slit 38 in the extension of this opening. In FIG. 3B, there is seen the cylinder 45 of cellular material which is positioned in the container 41. Then in FIG. 3C, the same cylinder 55 will be seen in hydraulic compression in the container 51 into which the product 59 has been introduced.
A pressurized container according to FIGS. 4A to 4C of a generally cylindrical shape consists of a cup 40.1 whereon there may be fitted a lid (not shown). This cup cooperates with the valve body 40.2 so as to form both an annular reservoir cavity 40.3 with a longitudinal axis X--X, containing a product 40.7 and into which a ring 40.8 of cellular material, such as shown in FIG. 2A, has been introduced, and the cavity of the valve 40.9. Inside this cavity, there are disposed an emergent valve actuating stem 40.4, a gasket 40.5 and a spring 40.6 which, together with the valve body, constitute the valve proper. The emergent stem 40.4 is intended to cooperate with a push button, not shown.
At the center of its upper plate 41.1, the cup 40.1 has moreover an opening 42.1 through which the emergent stem 40.4 passes, an external skirt 43.1 and an internal skirt 44.1 which are coaxial, the plate 41.1 having a substantially perpendicular orientation to these skirts.
In its bottom portion, the external skirt 43.1 has a profile 45.1 capable of receiving a complementary profile 41.2 integral with the valve body 40.2 of the valve; these two profiles are welded (FIG. 4C).
The internal skirt 44.1 of the cup has an internal diameter substantially corresponding to that of the gasket 40.5 and a height substantially identical with that of the cavity 40.3. The bottom surface 46.1 of the internal skirt of the cup is welded to the bottom of the valve body (FIG. 4C). A bevel 48.1 is situated on the internal circumference of the skirt 44.1. A notch 47.1 is, moreover, provided in the bottom internal circumference of the skirt 44.1. This notch interrupts the continuity of the weld between the internal skirt and the valve body.
The valve body 40.2 has on its circumference a profile 41.2 complementary to that 45.1 already described. This profile allows the valve body and the cup to be centered during assembly and is welded to the portion 45.1 of the cup. The valve body has an internal skirt 45.2 whose external diameter is substantially equal to the internal diameter of the internal skirt 44.1 of the cup, and these two elements are welded together. A groove 46.2 is provided on the external side face of this skirt 45.2 over its whole height, and on the upper edge of this groove is situated a notch 48.2.
The assembly of the pressurized container of FIG. 4C is shown in FIGS. 4A and 4B. First, the spring 40.6 is assembled around the emergent stem 40.4, then the gasket 40.5 is fitted in the space defined by the internal skirt of the valve body. Then the ring 40.8 and the cup 40.1 are positioned and the cup is welded to the valve body 40.2 at the end of the skirts.
The pressurized container is then filled through the valve. By pressing on the emergent stem 40.4, the pressurized product fills the first cavity 40.9 defined by the internal skirt of the valve body, passes through the notch 48.2, descends along the groove 46.2 through the bevel 48.1, then through the notch 47.1 and fills the cavity 40.3.
A push button and a lid, not shown, can then be mounted on the emergent stem and on the cup respectively.
When the emergent stem is depressed by means of the push button, the product follows the reverse path to that described for the filling of the device.
On injection of the product, the ring 40.8 is still compressed. When the product arrives through the openings 47.1 situated at the bottom of the cavity 40.3, the ring is pushed back towards the top. It follows therefrom that the container thus constituted functions in a multipositional mode. If the product passes during the filling towards the upper portion of the cavity by compressing the ring, and even by pushing it back towards the bottom, this does not change the functioning since, thanks to the slit in the ring 40.8, the ring is capable of completely expanding and pushing all the product towards the valve.
In a device whose element of cellular material would not have a slit, a recovery rate of the order of 60% would be obtained. On the other hand, the devices in accordance with the invention shown above make it possible to obtain a recovery rate of the product in excess of 90%.
Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that the invention may be practiced otherwise than as specifically described herein.
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A pressurized device for dispensing a product (19) includes a container body having a reservoir cavity (11.1), a valve (12) positioned at the top of the reservoir cavity, a dispenser (14) connected to the valve and a pressurizing device (15). The pressurizing device is formed by an element of cellular material with closed cells. The element of cellular material and the product are placed together inside the reservoir cavity so that the device dispenses the product when the valve is actuated. The element of cellular material has at least one slit at its circumference over its whole height measured along the longitudinal axis of the container body.
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BACKGROUND OF THE INVENTION
The invention relates to proportional solenoid-controlled valves and more specifically to a normally closed spool type solenoid valve which as it begins to open changes it opening or orifice size in proportion to the amount of current supplied to the solenoid.
Normally closed solenoid valves, such as shown in U.S. Pat. No. 3,737,141, are the type which pull a spring-biased poppet off a seat as the valve opens. Before the poppet opens, the solenoid force must overcome a pressure-induced force which holds the poppet closed. The amount of this force is dependent upon the pressure differential across the poppet and the area of the poppet seat. This pressure-induced force decreases as the valve opens, while the force produced by the solenoid increases as the valve opens. When the air gap between the pole piece and the armature is the largest, the force the solenoid generates is the weakest, which is converse to the requirements of a conventional poppet valve.
SUMMARY OF THE INVENTION
Rather than a conventional tapered end poppet closing an orifice, the present invention utilizes a spool in a bore which blocks lateral passages in an overlapping relation, thereby avoiding the pressure-induced forces of a conventional poppet which must be overcome. The spool and solenoid armature are held in the closed position by a dual spring design of differing spring rates. The first spring, with a very light spring rate, holds the spool in an extended overlap position when the solenoid is fully de-energized, to reduce spool leakage. When the solenoid is initially energized at current levels, for example 0.1 amps; the solenoid force will shift the spool to its initial opening position causing the first spring to compress to its stop with a very slight deflection of the much stiffer second spring. As the current level to the solenoid increases, the spool opens further and the second spring will compress so that the opening of the valve is proportional to the current supplied. The solenoid is externally adjustable by moving the stop on the first spring whereby the amount of current required to start the initial flow can be varied between, as for example, 0.1 amps and 0.4 amps. Low leakage across the spool is achieved in this dual spring design with the additional overlap caused by the first spring in the fully de-energized position of the solenoid.
It is therefore the principal object of the present invention to provide a normally closed spool type proportional solenoid valve with improved leakage characteristics.
Another object of the present invention is to provide a proportional solenoid valve with no differential pressure forces to overcome as the valve initially opens.
A further object of the present invention is to provide a normally closed solenoid valve with dual springs in a series arrangement having differing spring rates whereby added overlap is provided to improve the leakage characteristics.
Other objects and advantages of the present invention are described in or will become apparent from the following detailed description and accompanying drawings of the preferred embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal sectional view through the solenoid valve in its fully de-energized closed position; and
FIG. 2 is a curve illustrating flow vs. current of the present valve at various setting of the adjustable stop.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 illustrates a normally closed proportional solenoid-operated valve generally described by reference numeral 10. The valve 10 comprises a coil 12 which surrounds a fixed core assembly 14 which is held in place by a nut 15. Concentrically spaced inside the end of core 14 is an armature member 16 which defines an air gap 20 between the conical surface 18 of the armature and the pole face 22 of the core. Attached to core 14 is a sleeve assembly 24 which is welded to a stainless steel low magnetic sleeve 26 which in turn is welded to core 14. Sleeve assembly 24 includes a threaded left end 25 which mounts the solenoid valve 10 in whatever application the solenoid valve is being utilized. Surrounding the coil 12 of the solenoid is a conductive jacket 28 which protects the electrical components of the solenoid. Located in the left end of sleeve assembly 24 is a bore 30 which receives a valve body 32 held in place by snap ring 35. Passing through valve body 32 is a longitudinal bore 33 which is intersected by a pair of lateral passages 34. Slidably positioned in valve bore 33 is a valve spool 36 which is attached to armature 16 of the solenoid. The spool 36 includes a longitudinal passage 38 which equalizes the pressure on both ends of spool 36, including armature cavity 40 so that no pressure-induced forces are created on spool 36. The left edge 39 of spool 36 overlaps lateral passages 34 in the fully closed position of the valve, as illustrated in FIG. 1. Armature 16 is held in axial alignment in the valve through valve spool 36 sliding in valve body 32. Armature 16, in its de-energized position, is urged in a leftwardly direction by a pair of compression springs 44 and 46 positioned in series, one behind the other. Spring 44 having a relatively high spring rate contacts armature 18 through a plunger 42 while the left end of spring 44 contacts spring 46 through a second plunger member 48. Spring 46 is a very light spring, with a spring rate much less that that of spring 44. Extending from plunger 48 is an extension member 50 positioned in the center of spring 46 which engages an adjustable stop member 52. On the right end of stop 52 is a threaded screw 54 which is engageable by an allen wrench to longitudinally move the stop 52 forwards or backwards depending upon the desired current level at the initial opening position of the valve. A distance X is adjustably provided between extension 50 and stop member 52 which will be the plateau point where the heavy spring 44 begins to deflect and the light spring deflection is eliminated.
Solenoid valve 10 is designed to operate with an approximately 50 PSI pressure differential across lateral passages 34 to drain flowing out the left end of valve spool bore 33. The curent used in the solenoid coil can be either D.C. or dithered current. The solenoid valve 10 is utilized in systems requiring low volume in the one to two GPM range in applications such as speed control systems or as a pilot valve controlling a larger directional control valve. The valve 10 could also be converted to a normally open proportional solenoid valve with lateral passages through the spool 36, as well as a pull type conventional proportional solenoid valve.
OPERATION
Proportional solenoid valves, as compared with full open or closed solenoids, permit the orifice size or valve opening to be changed by varying the amount of current flow to the solenoid. With an increase in current, the orifice size increases proportionally so that a flow vs. current plot would be linear.
With solenoid valve 10 in its fully de-energized position, as illustrated in the drawing, the valve spool 36 completely overlaps passages 34 so that there is no flow through the valve. The amount of overlap of the spool, which is the distance between the left edge 39 of the spool and the lateral passages 34, is intended to reduce the amount of leakage between bore 33 and spool 36, in a normal tolerance fit. This overlap is approximately the same as the distance X seen at the right hand end of the valve between extension member 50 and adjustable stop 52. In light of the substantial overlap, passages 34 do not begin to open until extension 50 comes in contact with stop 52. Prior to this point, the primary spring force on the armature 16 is being caused by light spring 46, since spring 44 has no substantial deflection. After extension 50 contacts stop 52, spring 44 will begin to deflect and the spring resistance increases sharply. As initial current is supplied to solenoid coil 12, in the order of 0.1 to 0.2 amps, the solenoid force produced by this current flow across air gap 20 is applied to the springs 44 and 46. Since spring 46 is a very light spring, it will compress under this initial light solenoid force while spring 44, requiring a much higher force, will only slightly deflect. Spool 36 under the initial solenoid force moves to the right compressing spring 46 until extension 50 comes in contact with adjustable stop 52. The left edge 39 of spool 36 is now beginning to open lateral passages 34, and any further opening will require additional amperage to coil 12 to compress stiffer spring 44.
In viewing the flow vs. current plot of FIG. 2, it can be seen that as the amperage level is increased, the flow level increases at the same rate. To adjust the solenoid valve 10 to that point which the valve begins to open, can be accomplished by tightening or relieving screw 54 to vary the load on spring 46 and the position of stop member 52. FIG. 2 illustrates three separate curves wherein the amount of current at which the valve begins to open is varied to meet the particular requirements of each application. The movement of stop 52 not only adjusts the spring force on armature 16 but also the plateau point wherein the spring compression is transformed from spring 46 to spring 44. With an adjustable solenoid of this type, valve 10 can be adjusted so that the initial opening is at varying current levels. In doing so, the position of the flow curve, as seen in FIG. 2, using a constant pressure differential across the orifice can slide out the current scale while the slope of the curve remains the same. If a change in the slope of the curve is needed, a design change in the spring rates can be made to fit a particular application.
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A normally closed spool type solenoid-controlled valve which changes its opening in proportion to the amount of current supplied to the solenoid. The spool which blocks the valve opening in an overlapping relation is held in a closed position by a dual spring design having differing spring rates wherein the lighter spring holds the spool in an overlapping closed position.
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RELATED APPLICATION
[0001] The present application claims the benefit of prior filed co-pending U.S. Provisional Patent Application No. 61/236,406 filed on Aug. 24, 2009, the entire content of which is hereby incorporated by reference.
BACKGROUND
[0002] Modern vehicles include computer systems for controlling engine emissions, vehicle braking, and a variety of other items. The systems require data in order to function, such as oxygen level data for controlling engine emissions and wheel speed data for controlling braking. This data is generally supplied by sensors located throughout the vehicle. To ensure the integrity of the data provided by the sensors, controllers perform malfunction testing on the sensors (or the signals or data the sensors provide). If a sensor malfunction is detected (in other words, there is an error in the sensor output or sensor data), a warning light or similar indicator can be activated.
SUMMARY
[0003] While current vehicle systems are designed to monitor the functioning or operation of vehicle sensors and determine when a sensor malfunction occurs, such systems lack, at least in general, robust abilities for determining when the sensor malfunction ends. For example, a sensor malfunction might be caused by a powerful source of electromagnetic interference (“EMI”). Such a circumstance might occur if a vehicle passes near an electrical power generation plant, a radar or broadcast installation, or similar location. Once the vehicle moves outside the range of the EMI, the output from the sensor might return to within an acceptable range. However, in many vehicles, once a sensor malfunction occurs, the only way in which the malfunction or error may be cleared is to have a mechanic or technician access the system, check its operation, and perform an act that resets the system or otherwise removes the error.
[0004] A check of the sensor signal based on a re-detection by the failure monitoring function can be used as a mechanism to determine if a sensor has returned to normal operation. However, “good checking” is more than this. In general, malfunction monitoring functions are designed to avoid misdetection. On the other hand, “good check” functions are, in general, designed to avoid a false good check, i.e., a good check function has smaller tolerances for deviations and fewer conditions on the driving situation to perform the evaluation. Or, in other words, the tolerances and conditions used in good checking are different than those used to detect a malfunction.
[0005] Embodiments of the invention provide a mechanism for automatically determining whether a malfunctioning sensor has returned to a normal or acceptable operating range. In the parlance of the inventors, embodiments of the invention perform a “good check” on the sensor to determine whether the sensor has returned to normal or acceptable operation after a malfunction has been detected. When a previously-malfunctioning sensor passes the “good check,” warning lights (or tell-tale) indicators are shut off and systems that relied upon information from the malfunctioning sensor return to normal operation.
[0006] In one embodiment, the invention provides a controller for determining whether a previously-detected, vehicle-sensor malfunction still exists. The controller includes an electronic, non-volatile memory and an electronic processing unit connected to the electronic, non-volatile memory. The electronic processing module includes a malfunction monitoring module, a failure handling module, and a signal checking module.
[0007] The malfunction monitoring module monitors the operation of a brake light switch and generates a fault signal when the brake light switch malfunctions. The fault signal contains fault information and causes a tell-tale indicator to be activated or a vehicle control system (such as an engine control system, traction control system, vehicle stability system or the like) to modify its operation from a first operating state to a second operating state. The failure handling module stores the fault information and corresponding drive cycle information in the electronic, non-volatile memory.
[0008] The signal checking module retrieves the drive cycle information from the memory and performs a “good check” or signal check on information from the brake light switch. The signal check verifies that the brake light switch exhibits a predetermined pattern. If the brake light switch passes the signal check function, the signal checking module generates a reset signal that causes the tell-tale indicator to be deactivated, causes the vehicle control system to resume operation in the first operating state, or both.
[0009] In some embodiments, the predetermined pattern includes a low signal for a predetermined time, then a high signal for a predetermined time, and then a second low signal for a predetermined period of time. The signal checking module uses a counter to track whether the brake light switch exhibits the predetermined pattern. The signal checking module performs the signal check on information from the brake light switch while a vehicle monitored by the brake light is substantially stationary.
[0010] Other embodiments of the invention provide a method, executed by a controller including an electronic processing unit and an electronic, non-volatile memory, for determining whether a previously-detected, vehicle-sensor malfunction still exists. The method includes monitoring (with a malfunction monitoring module executed by the electronic processing unit) the operation of a brake light switch and generating a fault signal (containing fault information) when the brake light switch malfunctions. The method also includes activating a tell-tale indictor or modifying the operation of a vehicle control system from a first operating state to a second operating state when the fault signal is generated. In addition, the method includes storing the fault information and corresponding drive cycle information in the electronic, non-volatile memory using a failure handling module executed by the electronic processing unit.
[0011] The method also includes retrieving the drive cycle information and performing a signal check on information from the brake light switch. Performing the signal check on the brake light switch includes verifying that the brake light switch exhibits a predetermined pattern. If the brake light switch passes the signal check function, a reset signal is generated by the signal checking module. The reset signal causes the tell-tale indicator to turn off, the vehicle control system to resume operation in the first operating state, or both.
[0012] In some embodiments, performing the signal check on information from the brake light switch that verifies that the brake light switch exhibits the predetermined pattern includes performing the signal check on information from the brake light switch that verifies that the brake light switch generates a low signal for a predetermined amount of time, then a high signal for a predetermined amount of time, and then a second low signal for a predetermined amount of time. The method also uses a counter, with the signal checking module, to track whether the brake light switch exhibits the predetermined pattern. Performing the signal check includes performing the signal check while a vehicle monitored by the brake light switch is substantially stationary.
[0013] Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a perspective view of a vehicle including a vehicle control system according to one embodiment of the invention.
[0015] FIG. 2 schematically illustrates the vehicle control system of FIG. 1 according to one embodiment of the invention.
[0016] FIG. 3 schematically illustrates the functional operation of modules of the vehicle control system of FIG. 2 according to one embodiment of the invention.
[0017] FIG. 4 illustrates a first signal check performed by the signal checking module of FIG. 3 according to one embodiment of the invention.
[0018] FIGS. 5 a - c illustrate the first signal check of FIG. 4 according to one embodiment of the invention.
DETAILED DESCRIPTION
[0019] Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways.
[0020] It should also be noted that a plurality of hardware and software based devices, as well as a plurality of different structural components, may be utilized to implement the invention. Furthermore, and as described in subsequent paragraphs, the specific configurations illustrated in the drawings are intended to exemplify embodiments of the invention. Alternative configurations are possible.
[0021] FIG. 1 illustrates a vehicle 10 including a vehicle control system 11 . The vehicle control system 11 includes a brake pedal 14 and a brake light switch (“BLS”) 18 . The BLS 18 is wired to one or more brake lights 19 (wiring not shown). When an operator presses down the brake pedal 14 , the pedal 14 presses down and creates contact with the BLS 18 , which completes a circuit between the brake lights 19 and a power source, such as the vehicle's battery (not shown). With the circuit completed, the brake lights 19 are illuminated.
[0022] Information output by the BLS 18 is transmitted over a connection or network, such as a controller area network (“CAN”) bus 15 . The BLS 18 sends information over the bus 15 indicating whether the circuit between the BLS 18 and the brake lights 19 is complete (i.e., whether the brake lights are illuminated). For example, if the circuit is complete and the brake lights are being illuminated, the BLS 18 outputs a power or “high” signal to the bus 15 . Alternatively, if the circuit is incomplete and the brake lights 19 are not being illuminated, the BLS 18 outputs a no-power or “low” signal to the bus 15 .
[0023] Other components connected to the bus 15 may receive the information from the BLS 18 and use that information to control other aspects of the vehicle 10 . For example, a controller 16 receives information from the BLS 18 over the bus 15 . In some embodiments, the controller 16 provides electronic stability control (“ESC”) functionality. For example, when the controller 16 detects a loss of steering control (e.g., understeer or oversteer), the controller 16 automatically applies one or more individual brakes 17 to help steer the vehicle 10 in a desired direction. In some embodiments, the controller 16 also reduces engine power when it detects a skid or slide of the vehicle 10 until the vehicle operator regains control of the vehicle 10 .
[0024] As shown in FIG. 1 , the control system 11 includes the controller 16 , the bus 15 , and a plurality of sensors. The sensors can include one or more wheel speed sensors 21 , a yaw rate sensor 22 , a steering sensor 23 , a pitch sensor 24 , a roll sensor 25 , a longitudinal acceleration sensor 26 , a lateral acceleration sensor 27 , the BLS 18 , and a brake pressure sensor 14 a.
[0025] FIG. 2 schematically illustrates the vehicle control system 11 of FIG. 1 in greater detail. The numerous sensors depicted in FIG. 1 are represented generally by boxes 20 (Sensor 1 . . . Sensor N). As also shown in FIG. 2 , the controller 16 includes an input/output interface 32 , an electronic processing unit (“EPU”) 34 , and one or more memory modules, such as a random access memory (“RAM”) module 46 a and an electronically erasable programmable read-only memory (“EEPROM”) module 46 b. As shown in FIG. 2 , the input/output interface 32 transmits and/or receives information over the bus 15 . In other embodiments, the input/output interface 32 transmits and/or receives information directly to and/or from the sensors 20 rather than over the bus 15 .
[0026] The EPU 34 receives the information from the input/output interface 32 and processes the information by executing one or more applications or modules. The applications or modules are stored in memory (such as EEPROM 36 b ). The EPU 34 also stores information (e.g., information received from the bus 15 or information generated as a result of executing instructions) in memory. For example, as described below, the EPU 34 stores drive cycle information and fault information in the EEPROM 36 b.
[0027] FIG. 3 illustrates the functional operation of applications or modules executed by the EPU 34 of the controller 16 . As shown in FIG. 3 , the EPU 34 executes a malfunction monitoring module 40 , a failure handling module 42 , a vehicle control system 44 (such as an electronic stability control (“ESC”) program or application), and a signal checking module 46 . The malfunction monitoring module 40 receives sensor signals from the sensors 20 over the bus 15 (e.g., through the input/output interface 32 ) and saves the sensor signals to the memory. As shown in FIG. 3 , the malfunction monitoring module 40 saves filtered and/or compensated sensor signals to the memory rather than raw data. For example, over time a sensor 20 may become dirty or damaged, which can affect the sensor's operation. The malfunction monitoring module 22 applies an offset (positive or negative) to the signals received from a particular sensor 20 to compensate for the sensor's deterioration and stores the compensated sensor signal to the memory. As described below, if a particular sensor's offset gets too large (in either the positive or the negative direction), the malfunction monitoring module 40 determines that the sensor 20 is malfunctioning or faulty and generates a fault signal. The malfunction monitoring module 22 also saves additional information to the memory, such as sensor offsets, detected faults, and other statistical information about a particular sensor (e.g., an average sensor reading, a median sensor reading, etc.).
[0028] The main function or purpose of the malfunction monitoring module 40 is to determine if a particular sensor is malfunctioning or faulty. For example, as mentioned above, if a sensor's offset becomes too large, the malfunction monitoring module 40 may determine that the sensor 20 is malfunctioning. A variety of other algorithms and techniques for determining whether a sensor is malfunction can also be used including those disclosed in, for example, U.S. Pat. No. 6,834,221. As shown in FIG. 3 , when the malfunction monitoring module 40 detects a malfunctioning or faulty sensor, the module 40 generates a fault signal and sends the fault signal to the fault handling module 42 . The fault signal includes fault information based on the particular fault or malfunction observed by the malfunction monitoring module 40 . The failure handling module 42 stores the fault information and corresponding counter information, (which is referred to as “drive cycle information”) in memory. The drive cycle information indicates what signal check functions should be performed by the signal checking module 46 during the next drive cycle (e.g., the next time during which malfunction testing is performed) to determine whether a previously-detected fault still exists. For example, if the malfunction monitoring module 40 detects that the pressure sensor 14 a is malfunctioning and generates a fault signal, the fault handling module 42 saves drive cycle information to memory indicating that the signal checking module 46 should check the pressure sensor 14 a during a subsequent cycle to determine whether the previously-detected pressure sensor fault still exists.
[0029] As shown in FIG. 3 , the vehicle control system 44 requests the currently-detected faults from the failure handling module 42 . The failure handling module 42 retrieves the stored fault information from memory and sends the fault information to the vehicle control system 44 . In other embodiments, the vehicle control system 44 obtains currently-detected faults from the malfunction monitoring module 40 , the RAM 36 a, the bus 15 , or other components included in the system 11 .
[0030] After obtaining them, the vehicle control system 44 determines how to handle the current faults. In some embodiments, the vehicle control system 44 activates one or more warning lights or tell-tales in the vehicle 10 (e.g., on the vehicle's dashboard or instrument panel) in response to the currently-detected faults. In some applications, the warning lights or tell-tales provide information to the vehicle operator regarding the one or more faulty sensors 20 . In other applications, the warning lights or tell-tales provide information about a vehicle system. For example, if a faulty brake pressure sensor is detected the vehicle may activate a warning light regarding the anti-lock braking system rather than activating a specific warning light regarding the brake pressure sensor. Thus, the warning light or tell tale may only provide general information to the driver regarding the existence of a fault, whereas the control system 44 knows the specific nature of the fault.
[0031] Although not strictly required, in almost all instances the vehicle control system 44 modifies its operation in response to faults determined by the malfunction monitoring module 40 in addition to activating a warning light or tell tale. For example, if a particular sensor 20 is malfunctioning, the vehicle control system 44 changes its operation from a first operating state (e.g., ON) to a second operating state (e.g., OFF). In the first or “normal” operating state, the vehicle control system 44 operates as intended or programmed using all the data it receives from the sensors 20 . In the second operating state, the vehicle control system turns itself off (as noted) or, alternatively, operates in a state where information from faulty sensors is ignored, but control is still provided based on information from the remaining, non-malfunctioning sensors. Yet another option is for the vehicle control system 44 to operate in a manner in which some of its functionality or features are reduced. The factors determining the exact parameters of the second state of operation of the vehicle control system is a measure of the criticality or importance of the information provided by the malfunctioning sensor. For example, information from a yaw rate sensor may be critical to certain vehicle control functions (such as ESC), but may be unimportant or less critical to others (such as traction control). Thus, if a yaw rate sensor malfunction is detected, traction control may continue to function based on information from other sensors, but ESC might be turned off. If the vehicle control system 44 deactivates or modifies its functionality or other types of vehicle control or monitoring functionality, the vehicle control system 44 can activate one or more warning lights or tell-tales that warn the vehicle operator of the modified operating state.
[0032] The signal checking module 46 retrieves drive cycle information stored in memory and performs various “good check” or signal checks to determine whether a previously-detected sensor malfunction still exists. In some embodiments, the signal checking module 46 is initialized during each new ignition cycle and retrieves the stored drive cycle information upon each initialization. In other embodiments, the signal checking module 46 retrieves stored drive cycle information from memory at various times while the controller 16 is operating.
[0033] Performing a signal check includes testing current readings or information from a particular sensor 20 . Therefore, the signal checking module 46 obtains current sensor readings from the memory, the bus 15 , the malfunction monitoring module 40 , or from other components of the system 11 . The current sensor readings include compensated or filtered sensor signals or information, raw sensor information, current sensor offsets, and/or other statistical information about a particular sensor 20 . Once the signal checking module 46 obtains current sensor readings, the module 46 compares the information to one or more thresholds to determine whether a previously-detected fault still exists. The signal checking module 46 can also execute a test on a sensor by sending information to a sensor and observing the response.
[0034] If the signal checking module 46 determines that a previously-detected fault doesn't exist anymore, the module 46 resets the corresponding fault information and/or drive cycle information in memory. The signal checking module 46 resets the drive cycle information by generating a reset signal. The failure handling module 42 receives the reset signal and updates the fault information and/or drive cycle information stored in memory to indicate that the previously-detected fault no longer exists (e.g., by deleting the previous fault and/or drive cycle information or setting a fault bit or flag to an “okay” or “no fault” value). When the vehicle control system 44 subsequently requests the current faults from the failure handling module 42 , the failure handling module 42 informs the vehicle control system 44 that the previously-detected fault no longer exists (e.g., by failing to list the fault as one of the current faults). The vehicle control system 44 re-assesses the current faults and, in some embodiments, deactivates a previously-activated warning light or tell-tale within the vehicle 10 and/or returns its operation back to a first or original operating state (e.g., an ON state).
[0035] On the other hand, if the signal checking module 46 determines that the previously-detected fault still exists, the signal checking module 46 sets the corresponding fault and/or drive cycle information in memory. By setting the corresponding fault and/or drive cycle information in memory, the signal checking module 46 ensures that the stored fault information and/or drive cycle information continues to indicate that the fault exists so that (1) the vehicle control system 44 is informed of the existence of the fault and (2) the signal checking module 46 will run another signal check on the fault during subsequent operation. The signal checking module 46 sets the fault and/or drive cycle information by generating a set signal. The failure handling module 42 receives the set signal and ensures that the fault information and/or drive cycle information in memory continues to indicate that the fault still exists. In other embodiments, the signal checking module 46 simply fails to reset the fault and/or drive cycle information (e.g., fails to generate and output a reset signal), which retains the fault and/or drive cycle information in the same state as before the signal checking module 46 performed its signal checks.
[0036] FIG. 4 illustrates a first BLS signal check 80 performed by the signal checking module 46 . The signal checking module 46 executes the first BLS signal check 80 after, for example, the malfunction monitoring module 40 detects a BLS permanent high malfunction. A BLS permanent high malfunction occurs when the malfunction monitoring module 40 determines that the BLS 18 is stuck in a “high” position (i.e., has been outputting a “high” signal for a predetermined time).
[0037] As shown in FIG. 4 , the first step of the first BLS signal check 80 includes determining whether the retrieved drive cycle information specifies that a BLS permanent high malfunction has occurred (step 81 ). The retrieved drive information can includes a flag or bit (e.g., a BLS failure drive cycle bit or flag) that is set accordingly. If this flag is not set, the signal checking module 46 ends the first BLS signal check 80 . If this flag is set, the signal checking module 46 executes a BLS test 82 , such as a BLS permanent high test.
[0038] FIGS. 5 a -c illustrate the BLS test 82 , which determines whether the BLS 18 exhibits a predetermined pattern. The pattern includes a low signal, followed by a high signal, and followed by second low signal. It is to be understood that the second low signal may be substantially the same as the first signal or may vary therefrom. This particular pattern indicates that the BLS 18 is not stuck in a permanent high state. In some embodiments, the BLS 18 must exhibit each signal of the pattern for a predetermined time (e.g., 0 to 1 second, which varies based on the characteristics of the vehicle). The predetermined time may be the same for each signal of the pattern or may be different.
[0039] The signal checking module 46 uses a BLS “OK” Counter to detect the predetermined pattern. The BLS “OK” Counter includes a bit for each state of the predetermined pattern, and the signal checking module 46 sets each bit as it observes each state. Therefore, the BLS “OK” Counter includes 3 bits, wherein the bits represent whether the BLS 18 has demonstrated the first (low signal), second (high signal), and third (low signal) state of the desired pattern. Initially the BLS “OK” Counter bits is set to 000 (i.e., the decimal value of zero) to indicate that the BLS 18 has not yet demonstrated any of the states of the pattern. As the signal checking module 46 observes each state, the module 46 sets the corresponding bit. In particular, after the module 46 observes the first state of the pattern, the signal checking module 46 sets the first bit of the BLS “OK” Counter (i.e., bit 0 ) to “1,” which sets the BLS “OK” Counter to a decimal value of 1. Similarly, after the module 46 observes the second state of the pattern, the module 46 sets the second bit of the BLS “OK” Counter (i.e., bit 1 ) to “1,” which sets the BLS “OK” Counter to a decimal value of 3. Finally, after the module 46 observes the final state of the pattern, the module 46 set the third bit of the BLS “OK” Counter (i.e., bit 2 ) to “1,” which sets the BLS “OK” Counter to a decimal value of 7.
[0040] FIG. 5 a illustrates the portion of the BLS test 82 that determines whether the BLS 18 is demonstrating the first state of the desired pattern (i.e., a low signal). The signal checking module 46 starts by determining if the BLS “OK” Counter is set to the decimal value of 0 (step 90 a ). If the BLS “OK” Counter is not set to 0,the signal checking module 46 has already observed at least one of the states of the desired pattern, and the signal checking module 46 proceeds to check for other states of the pattern (see FIGS. 5 b and 5 c ).
[0041] If the BLS “OK” Counter does equal 0 (step 90 a ), the signal checking module 46 determines whether the BLS 18 is currently demonstrating a low signal (step 92 a ). If the BLS 18 is not currently outputting a low signal, the signal checking module resets a filter timer (step 94 a ) (whose function is described below) and ultimately exits the test 82 . The test 82 may be subsequently re-initiated (e.g., in subsequent initiations of the signal checking module 46 ) to check for the first pattern state.
[0042] If, however, the BLS 18 is currently outputting a low signal (step 92 a ), the signal checking module 46 determines whether the BLS 18 has been outputting this signal for the predetermined time (step 96 a ). The signal checking module 46 uses a filter timer to track how long the BLS 18 outputs a particular signal. The filter timer is initially set to 0 when the test 82 is started and is reset after a particular pattern state is observed (see step 99 a ) or when a particular state is not initially observed (see step 94 a ). As shown in FIG. 6 a , if the BLS 18 has not been outputting a low signal for at least the predetermined time, the signal checking module 46 increments the filter timer (step 97 a ) and ultimately exits the test 82 .
[0043] However, if the BLS 18 has been outputting a low signal for at least the predetermined time (step 96 a ), the BLS 18 has satisfied the first state of the desired pattern and the signal checking module 46 sets a first bit (i.e., bit 0 ) of the BLS “OK” Counter to “ 1 ” (i.e., setting the BLS “OK” Counter to the decimal value of 1) (step 98 a ). In addition, the signal checking module 46 resets the filter timer (step 99 a ) and proceeds to check for the second state of the desired pattern (see FIG. 5 b ).
[0044] FIG. 5 b illustrates the portion of the BLS test 82 that determines whether the BLS 18 is outputting a high signal for at least the predetermined time and FIG. 5 c illustrates the portion of the BLS test 82 that determines whether the BLS 18 is outputting a low signal for at least the predetermined time. Because these portions of the BLS test 82 are similar to the portion illustrated in FIG. 5 a , the details are not described in detail.
[0045] Returning to FIG. 4 , at step 100 , after executing the BLS test 82 , the signal checking module 46 determines if the BLS 18 passed the BLS test 82 . In particular, the signal checking module 46 determines if the BLS “OK” Counter is set to the decimal value of 7. If so, the signal checking module 46 resets the BLS failure signal check flag to indicate that the previously-detected malfunction of the BLS 18 no longer exists (step 102 ). To reset the BLS failure signal check flag, the signal checking module generates a reset signal. The failure handling module 42 receives the reset signal and ensures that the fault information and drive cycle information stored in memory no longer indicate that a BLS permanent high malfunction exists. When the vehicle control system 44 subsequently requests the current faults from the failure handling module 42 , the vehicle control system 44 will be informed that the BLS permanent high malfunction no longer exists. Based on this information, the vehicle control system 44 deactivates a warning light or tell-tale and/or modifies its operation back to a first operating state (e.g., an ON and fully functional state). After resetting the BLS failure signal check flag, the signal checking module 46 exits the signal check 80 .
[0046] On the other hand, if the BLS 18 does not pass the BLS test 82 , the signal checking module 46 sets the BLS failure signal check flag (step 104 ) before exiting the signal check 80 by generating a set signal. The failure handling module 42 receives the set signal and ensures that the fault information or drive cycle information stored in memory continues to indicate that the BLS permanent high malfunction exists.
[0047] In some embodiments, the signal checking module 46 executes particular signal checks during certain driving maneuvers. For example, the signal checking module 46 may execute the signal checks 80 when the vehicle 10 is substantially stationary or at a standstill. The signal checking module 46 may also execute other tests during a particular signal check. For example, the signal checking module 46 may execute the additional tests along with the BLS test 82 , such as when the BLS 18 malfunctions and other sensors 20 also malfunction.
[0048] Thus, the invention provides, among other things, a controller for determining whether a previously-detected, vehicle sensor malfunction still exists by executing various signal checks and signal check functions using sensor-related information. Various features and advantages of the invention are set forth in the following claims.
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A mechanism for determining whether a malfunctioning sensor has returned to a normal or acceptable operating range. The mechanism includes controllers and methods that perform a “good check” on the sensor to determine whether the sensor has returned to normal or acceptable operation after a malfunction has been detected. When a previously-malfunctioning sensor passes the “good check,” warning lights (or tell-tale) indicators are shut off and systems that relied upon information from the malfunctioning sensor return to normal operation.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to a railway or railroad track joint, and more particularly, to an improved electrically insulated bonded rail joint incorporating a non-conductive spacer in or associated with a rail bonding adhesive. The present invention also relates to a method for bonding such electrically insulated rail joints. The present invention provides more control over the spacing of the adhesive layer to achieve a stronger joint and a more predictable and stable electrical insulation of a track circuit with improved bonding.
2. Description of the Prior Art
Joining of two railroad rails has had quite a varied history. Originally, two rail ends were butted together, and "bars" or "fishplates" generally about three feet long, were used as scabs across the rail joint, one inside and one outside of the rail. The "bars" or "fishplates" and the rails were drilled to accept bolts, which once inserted and tightened, held the rails and fishplates together as one piece.
One limitation associated with joining two rails in this manner is that there is metal-to-metal contact between the rails and the fishplates, which results in rail joints that are not electrically insulated from each other. Electrical insulation between adjoining rails is desired in some applications within the rail industry. For example, where rails are electrically insulated from their adjoining rails, the metal wheels or trucks of a train or similar railed vehicle crossing the insulated rails can be used to complete an electrical circuit. The completed electrical circuit is used in many applications, such as triggering signalling devices further down the track, moving switches, or sending computer signals to locate the train on the track for a central dispatcher.
The first attempts to electrically insulate rail joints simply consisted of a flexible, formed, durable insulating material inserted between the fishplates and the rails, and between the butted rail ends. However, this is far from the present state of the art.
The second stage in the evolution of the development of electrically insulated rail joints, provided for embedding the metal fishplates within an insulating shielding material. Most commonly polyurethane is chosen as the insulating material for this application.
The third stage in the evolution of the development or the rail joints was the formation of "bonded" railroad rail joints. With bonded railroad rail joints, a rail bonding adhesive, typically an epoxy material, is used to chemically glue or bond the fishplates and rails together as one unit. Additionally, in some applications, a web-like or matting material is inserted between the fishplates and the rails which is coated on one or both sides with rail bonding adhesive. The bonded rail joint is typically the strongest rail joint and is a very solid rail joining means. Bonded rail joints prevent movement of one bonded rail relative to the other bonded rail. While bolts similar to those described above are still used in this application, the bolts function mainly as a press to hold the rail bonding adhesive, the fishplates and the rails together until the adhesive sets and forms the bond.
With the bonded railroad rail joints discussed above, to form an electrically insulated as well as a bonded rail joint, two rail ends are butted with an insulating material inserted therebetween. The insulating material between the rail ends is often called an "end post". Further, the vertical surfaces of the rails are coated on the inside and outside with a layer of rail bonding adhesive for a distance of about 1.5 feet on both sides of the point where the rail ends abut the insulating material. "Inside" and "outside" means here with respect to the track itself as though the rail was installed on a track bed, with "inside" denoting the rail surface between the rails and "outside" denoting the surface of the rail opposite the "inside" surface. In some applications, a layer of matting material, which is typically made of fiberglass and is on the order of 1/16 inch thick and is quite shapable, is laid on top of the rail bonding adhesive layer. The matting material layer is in turn covered with another layer of rail bonding adhesive. The rail bonding adhesive soaks through the matting layer. Subsequently, metal fishplates are placed on the inside and outside of the rails and bolts (usually 4-6) are installed horizontally (with respect to the track bed) through the two fishplates and the rails. The tightening of the bolts holds the fishplates, rail bonding adhesive and rails together as one unit while the rail bonding adhesive sets. The rail bonding adhesive can cure at ambient temperatures or at elevated temperatures. The resulting rail joint bond is quite strong and electrically insulated.
A limitation of the bonded/insulated rail joint is that the process of tightening the nuts on the bolts squeezes out all or nearly all of the rail bonding adhesive and crushes the matting material layer, resulting in a very thin adhesive layer in the rail bonding joint. This results in a weaker bonded rail joint and less electrical insulating capability.
Attempts have been made in the prior art to provide a spacer between the fishplates and the rails to prevent the formation of an unacceptably thin adhesive layer in the rail bonding joint. U.S. Pat. No. 3,381,892 to Eisses discloses a rail joint construction which includes an insulating layer comprising a cold hardening paste layer 6 which is surrounded by nylon rods 9 and 10. The nylon rods 9 and 10 serve as spacing elements spacing the fishplates 3 and 4 from the rails 1 and 2.
British Patent No. 2,071,187 discloses an insulated rail joint comprising a fishplate of insulating material having a series of vertical ribs spaced along its rail engaging faces. The plastic material of the fishplate may include abrasive-proof grains suspended within the plastic. The abrasive-proof grains are apparently intended to increase the frictional engagement of the ribs with the rail and do not perform a spacing function.
However, none of the prior art references discloses a bonded rail joint or method of making a bonded rail joint wherein the thickness of the rail bonding adhesive layer and the corresponding degree of electrical insulation can be easily modified at will to provide a bonded rail joint of a desired thickness and electrical insulating capability. Thus, a need exits in the prior art for a bonded rail joint and for a method of making a bonded rail joint wherein the thickness of the adhesive layer in the bonded rail joint can be easily and reliably modified at will to provide a rail joint having an adhesive layer of a desired thickness and insulating capability whether manufactured under factory or field conditions.
SUMMARY OF THE INVENTION
The present inventors have found that a rail bonding adhesive having non-conductive spacers embedded therein provides control over the final thickness of the rail bonding adhesive layer and, hence, the electrical insulating capabilities of the bonded rail joint. Non-conductive glass bead-like spacers are preferred. Advantages of a bonded/insulated rail joint employing a rail bonding adhesive in which non-conductive spacers are embedded include:
a) differently sized spacers (or separating material) can be used for different applications (cold weather, hot weather tracks etc);
b) varying the non-conductive spacer size or diameter results in varying the depth or thickness of the bonded rail adhesive joint;
c) varying the non-conductive spacer concentration within the rail bonding adhesive permits varying the ratio of adhesive/non-conductive spacers providing for more control over the strength and cost of producing the bonded rail joint; and
d) the non-conductive spacers can be either non-coated or coated with a substance which increases the adhesion between the non-conductive spacers and the rail bonding adhesive to further strengthen the bond.
In one embodiment of the present invention, a series of rail bonding adhesives can be pre-manufactured embedded with various non-conductive spacer sizes and concentrations for varying conditions and requirements. The non-conductive spacers pre-embedded within the rail bonding adhesive itself is an advantage where the rail joint is assembled at the track bed work site as opposed to being preassembled at the factory and then installed at the track bed work site.
In an alternative embodiment, the non-conductive spacers are provided separately from the rail bonding adhesive. The non-conductive spacers are then mixed with the rail bonding adhesive immediately before applying the adhesive either at the factory or the work site or are coated as a layer on top of an applied layer of rail bonding adhesive. This permits selection of various sizes and concentrations of non-conductive spacers for varying conditions and requirements.
A complete understanding of the invention will be obtained from the following description when taken in connection with the accompanying drawing figures wherein like reference characters identify like parts throughout.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a pair of adjacent rail sections and a bonded electrically insulated rail joint which is the subject of this invention;
FIG. 2 is a cross section on line II--II in FIG. 1;
FIG. 3 is an enlarged portion of the rail joint shown in FIG. 2;
FIG. 4 is a perspective view of a matting material layer of the rail joint according to the present invention; and
FIG. 5 is an enlarged section of a portion the rail joint shown in FIG. 2 showing the compression of the rail joint in detail.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings and particularly to FIG. 1, there is illustrated a bonded electrically insulated rail joint generally designated by the numeral 10 for bonding and electrically insulating a pair of adjacent rail sections 12 and 14. Rail joint 10 electrically insulates electrical signals present on adjacent rail sections to insure proper railroad signal system operation. Rail joint 10 eliminates the problems associated with short circuited adjacent rail sections and the resultant signal system errors.
FIG. 1 illustrates the rail joint 10 positioned between first rail section 12 and second rail section 14. Rail joint 10 bonds rail sections 12 and 14 to each other while electrically insulating electrical signals present on rail section 12 from electrical signals present on rail section 14. Connecting bars or fishplates 16 and 18 are also shown in the drawings. Fishplates 16 and 18 are also referred to commonly in the railroad industry as "splice bars" or "joint bars". A matting material layer 20 extends partially around fishplate 16 and, similarly, a matting material layer 22 extends partially around fishplate 18. Matting material layer 22 is shown in FIG. 4. Matting material layers 20 and 22 are each coated with a rail bonding adhesive as discussed in detail below in connection with FIG. 3. A plurality of bolts 24 rigidly connects fishplate 16 and fishplate 18 to rail sections 12 and 14.
As shown in FIG. 1, an electrically insulating spacer 26 is interposed between the ends of rail sections 12 and 14. As shown in FIG. 2, holes punched into the matting material layers 20 and 22 receive bolts 24 and insulated bushings 28. The bolts 24 must be at least partially surrounded by insulating bushings 28 as shown in FIGS. 2 and 3 to prevent the bolt from conducting electric current between the rail sections and the fishplates and thereby assuring electrical insulation of the rail joint. Washer 30 and nut 32 complete the mechanical assembly of the rail joint.
FIG. 3 is an enlarged section view of a portion of rail joint 10. Only the rail 14, shown bonded with fishplates 16 and 18, will be discussed for brevity of discussion, but the rail joint between fishplates 16 and 18 and rail sections 12 and 14 is similarly formed. Matting material layer 22 is interposed between rail section 14 and fishplate 18. A first layer of rail bonding adhesive 34 is interposed between matting material layer 22 and rail section 14. A plurality of non-conductive spacers is embedded within the first layer of rail bonding adhesive 34. A second layer of rail bonding adhesive 38 is shown in FIG. 3 interposed between matting material layer 22 and fishplate 18. Again, a plurality of non-conductive spacers 36 is embedded in the second layer of rail bonding adhesive 38 in FIG. 3.
While spacers of any symmetrical geometric configuration will work with the present invention, spherical or bead-like spacers are the preferred embodiment. As shown in FIG. 4, after compression of the rail joint by the tightening of nuts 32 on bolts 24, non-conductive spacers 36 maintain the proper spacing between fishplates 16 and 18 and rail section 14 despite any deformation or crushing of matting material layer 22 during the compression process.
Generally, the non-conductive spacers are between 20-40/1000 of an inch in diameter and are present in a concentration by weight of rail bonding adhesive on the order of 20-40%. While a range of diameters is within the scope of the present invention, it should be noted that too small a non-conductive spacer diameter will result in a rail bonding adhesive layer which is too thin and, therefore, not strong enough and/or will not possess sufficient electrical insulating capabilities. At the other extreme, too large a non-conductive spacer diameter will result in a rail bonding adhesive layer which is also not strong enough and/or will result in wasting needless rail bonding adhesive. Similarly, a low concentration of non-conductive spacers will not insure uniform and predictable spacing. At the other extreme, too high a concentration of non-conductive spacers will result in an insufficient amount of rail bonding adhesive in the rail joint which can lead to a weak joint and/or to premature joint failure.
The rail bonding adhesive 34,38 can be any of the types well known in the art. Similarly, matting material layer 22 can be any of the types well known in the art, such as fiberglass matting material.
In the preferred embodiment of the invention, non-conductive spacers 36 are embedded in the rail bonding adhesive before it is applied to the rail joint. In this embodiment, several rail bonding adhesive formulations can be developed with non-conductive spacers of varying sizes and concentrations to yield rail bonding joints of various thicknesses and insulating capabilities as required or desired for various applications.
Alternatively, the non-conductive spacers can be mixed with rail bonding adhesive at the factory or the track work site by the craftsperson forming the bonded rail joint. In this embodiment of the present invention, the craftsperson needs only non-conductive spacers of various diameters and can modify concentrations of a given diameter of non-conductive spacers in the rail bonding adhesive as required or desired.
In an alternative embodiment of the present invention, a first layer of rail bonding adhesive 34 is applied to rail section 14. The first layer of rail bonding adhesive 34 is then covered with a plurality of non-conductive spacers 36. Matting material layer 22 is then placed over first layer of rail bonding adhesive 34. A second layer of rail bonding adhesive 38 is applied to the exposed surface of matting material layer 22 and a second layer of rail bonding adhesive 38 is coated with a plurality of non-conductive spacers 36. Fishplate 18 is then placed, over the rail joint along with fishplate 16, with an identical rail bonding adhesive layer configuration having been applied to the opposite face of rail section 14. When nut 32 is tightened on bolt 24, non-conductive spacers 36 prevent the collapse of the matting material layer 22 and space rail section 14 and fishplate 18 apart according to the diameter of the non-conductive spacers 36. Similar spacing is achieved when the embodiment shown in FIG. 3 is applied to fishplate 16 and the interface between rail section 12 and fishplates 16 and 18.
In still another embodiment of the present invention, non-conductive spacers 36 can be coated with a layer of a substance such as, for example, a saline solution which increases adhesion between the nonconductive spacers and the rail bonding adhesive to further strengthen the formed bond.
The present invention permits reliably reproducing adhesive joints of a given thickness, which in turn results in reliably reproducible electrical insulating qualities.
While the embodiments of the subject invention have been described and illustrated, it is obvious that various changes and modifications can be made therein without departing from the spirit of the present invention which should be limited only by the scope of the appended claims.
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The present invention generally relates to a railway or railroad track joint, and more particularly, to an improved electrically insulated bonded rail joint incorporating a non-conductive spacer in or associated with a rail bonding adhesive. The present invention also relates to a method for bonding such electrically insulated rail joints. The present invention provides more control over the spacing of the adhesive layer to achieve a stronger joint and more predictable and stable electrical insulation of a track circuit with improved bonding.
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TECHNICAL FIELD
[0001] The present invention relates to a window having an integral solar heat collector.
BACKGROUND OF THE INVENTION
[0002] Windows may incorporate a transparent solar collector and thereby offer a more pleasing architectural aesthetic than opaque solar heat collectors. These windows typically include two glass sheets between which either air or a liquid is received—the latter being described in GB2450474. A problem experienced with these liquid-circulating transparent collectors has been the necessity for connecting the window to a remote heat exchanger in which the energy-absorbing fluid piped from the collector transfers heat energy to some other fluid for utilisation. This has involved an undesirably large amount of plumbing, pump and pipe fittings, together with the additional volume of heat absorbing fluid required to fill such plumbing, as well as the labour and materials in the piping and assembly thereof. It also has involved excessive opportunity for leakage, property damage and loss of comparatively expensive energy-absorbing working fluid, say when a transparent pane is broken. It is an object of the present invention to overcome or substantially ameliorate the above disadvantages or more generally to provide an improved heat absorbing window.
DISCLOSURE OF THE INVENTION
[0003] According to one aspect of the present invention there is provided a heat-absorbing window assembly comprising:
[0000] first and second transparent panes separated from one another to provide a first passageway therebetween for receiving a working fluid;
a frame in which a periphery of the panes is secured;
a heat exchanger secured in the frame, the heat exchanger having a second passageway therein for the working fluid and a third passageway therein for a service fluid;
and conduit means coupling the first and second passageways to make a working fluid circuit in the frame by which heat energy absorbed by the working fluid in the first passageway is supplied to the heat exchanger.
[0004] Preferably the frame includes elongate upper and lower members in which opposing upper and lower ends of the first passageway are received, and the second and third passageways extend longitudinally within the upper member.
[0005] Preferably inlet and outlet ports proximate opposing ends of the third passageway extend through openings in the frame proximate opposing ends of the upper member.
[0006] Preferably the conduit means comprise upper and lower headers extending adjacent upper and lower ends of the first passageway respectively, longitudinally spaced openings in the upper and lower headers providing fluid communication between each header and its respective end of the first passageway, and a first and second conduit connecting the second passageway to the upper and lower headers respectively.
[0007] Preferably the window further comprises a tank within the frame for providing an expansion space. Preferably the tank is mounted in the upper member and connected to the first conduit.
[0008] Preferably the second and third passageways are coaxial, most preferably the third passageway is annular in cross section and surrounds the second passageway.
[0009] Preferably the third passageway is provided in a tubular member surrounded by thermal insulation and received within the upper frame member.
[0010] Preferably the service fluid flows through the third passageway in a direction opposite the flow of the working fluid through the second passageway.
[0011] This invention provides a heat-absorbing window assembly which is effective and efficient in operational use, and which may be economically constructed. The heat-absorbing window has a compact working circuit all located within the window frame, which minimizes the amount of working fluid in the system. This also reduces the flow friction and heat losses in the circuit, and results in better heat transfer characteristics. Pumping energy is eliminated in the recirculating liquid flow, which is self regulated as the higher buoyant force induces higher flow resistance.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Preferred forms of the present invention will now be described by way of example with reference to the accompanying drawings, wherein:
[0013] FIG. 1 is a schematic front sectional view of a heat absorbing window according to an exemplary embodiment of the invention, and
[0014] FIG. 2 is a schematic section along line AA of FIG. 1 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0015] A heat-absorbing window includes elongate upper and lower members 10 , 11 and side members 12 , 13 formed of metal or a rigid polymer. The members 10 - 13 are hollow, having an elongate open mouth in which the edges of first and second panes 14 , 15 of transparent glass or polymer are received. The members 10 - 14 are connected by joints (not shown) at their ends to form a rectangular window frame 16 . In use the frame 16 is fastened in an architectural opening and may be fixed in position, or optionally it may be mounted by hinges or rails for pivoting or sliding movement. The frame is mounted upright in the orientation shown in the drawings, but may be inclined upwardly as when mounted in a pitched roof to provide a skylight, or when a hinged window is opened.
[0016] The first and second panes 14 , 15 are flat, rectangular and parallel, being spaced apart to define a first passageway 17 therebetween. The long edges of the panes 14 , 15 received in the side members 12 , 13 are sealed closed, while the short edges are connected to upper and lower distribution headers 18 , 19 . To improve the heat absorption of the working fluid, the surface of the inner transparent pane 14 (the pane that bounds the indoor space) can be applied with a layer of reflective film (not shown), subjecting the first passageway 17 to a reflected radiation on its path back to the ambient environment. This reflective layer also advantageously also reduces the space heat gain within the building. To extend the functionality of the window, the outer transparent pane 15 can be a photovoltaic glazing of which the solar cells (not shown) can be cooled by the fluid flow in the first passageway 17 , and the electricity generated is used to support other building activities.
[0017] The headers 18 , 19 are received in the upper and lower members 10 , 11 respectively and comprise like tubular members with longitudinally spaced openings in their walls that communicate with upper and lower edges of the first passageway 17 . The end 20 of the upper header 18 is closed, and the opposing end 21 is connected by a conduit 22 to a second passageway 23 formed in a copper tube 24 . The end 25 of the lower header 19 is connected by a conduit 26 to the second passageway 23 , while the opposing end 27 is connected via a shut-off valve 28 to a charging and discharging port 29 . For draining, the lower header 19 slopes towards the end 27 . The patterns of openings in the headers 18 , 19 for connection to the first passageway 17 are arranged to produce a uniform upward flow of fluid across the full width of the first passage 17 . The cross-section of the distribution headers 18 , 19 may alternatively be rectangular, or may vary in shape or size along its length.
[0018] The copper tube 24 and the second passageway 23 defined by it form part of a narrow elongate heat exchanger 30 mounted in the upper member 10 , which also includes an outer tube 31 coaxial with the tube 24 to define a third passageway 32 which is annular in cross section. The third passageway 32 is substantially coextensive with the second passageway 23 and includes inlet and outlet ports 33 , 34 proximate opposing ends of the third passageway 32 that extend through openings in the frame proximate opposing ends of the upper member 10 . The heat exchanger 30 is fixed in the upper frame member 10 by means of pipe fittings 38 fixed at opposing ends of the hollow member or outer tube 31 and extending through respective apertures in the frame member 10 . The fittings 38 thus serve both to mechanically mount the heat exchanger 30 and to provide a fluid connection to the inlet and outlet ports 33 , 34 . In alternative embodiments (not shown) one or other of the tubes 24 , 31 may be integral with the upper frame member 10 .
[0019] A tank 35 is mounted within the frame for providing an expansion space. As illustrated, the tank 35 is mounted in the upper member 10 and connected to the conduit 22 . An air vent (not shown) is provided for venting air from the system. For air venting the heat exchanger 30 and upper header 18 are sloped upward toward the tank 35 , the connection to the conduit 22 thereby being at the highest point in the circuit.
[0020] The window frame 16 is filled with thermal insulation material 36 such as polyurethane foam, surrounding the heat exchanger 30 , the conduits 22 , 26 and the periphery of the panes 14 , 15 .
[0021] The first passageway 17 , headers 18 , 19 and conduits 22 , 26 are filled with a working fluid such as a transparent fluid such as water or alcohol, or a mixture of water and alcohol. Optionally the working fluid can be another pure or mixed transparent liquid, or semi-transparent (coloured) liquid to alter the optical properties, in particular the solar transmittance of the glazing in the visible range. Solar radiation absorption elevates the temperature of the working fluid, and induces a natural circulation flow as a result of the thermosyphon effect. Referring to FIG. 1 , the working fluid flows in an anti-clockwise circuit up through the first passageway and through the heat exchanger 30 , returning via the conduit 26 to the first passageway.
[0022] A service fluid, as for providing a hot water service in a building, is connected to flow between the inlet and outlet 33 , 34 in counter-flow to the working fluid in the heat exchanger 30 . In the case of a hinged window, the inlet and outlet 33 , 34 are connected via two flexible hoses to the service fluid pipework inside the building structure. A plurality of heat-absorbing windows can be connected together by the service fluid pipework, either in parallel or, series, or a combination thereof, in order to maximize the heat collecting capacity. Additionally a phase-change-material can be applied at the flow channel 31 of the heat exchanger 30 . This additional heat storage helps to stabilize the working temperature of the service fluid and thus further improve the overall heat exchange performance. When the working fluid has been drained out, the window air circulation through the first passageway provides a limited amount of heat exchange capability.
[0023] Aspects of the present invention have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the scope thereof. For instance, a refrigerant could be used as the working fluid such that the first passageway 17 will behave as an evaporator and the heat exchanger will behave as a condenser. Alternatively, to enhance thermal comfort in winter a hot service fluid could be directed to the heat exchanger and a pump may be mounted to the frame for circulating the working fluid.
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A window with an integral solar heat-absorber is provided in a compact, low-cost package. Two transparent panes are separated from one another to provide a first passageway for receiving a working fluid. The periphery of the panes is secured in a frame in which a heat exchanger is also secured, the heat exchanger having a second passageway for the working fluid and a third passageway for a service fluid. The first and second passageways are coupled to make a working fluid circuit.
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FIELD OF THE INVENTION
This invention relates to a wheelchair, and, more particularly, relates to a power-assisted wheelchair.
BACKGROUND OF THE INVENTION
Wheelchairs are now in wide use, and various types have been heretofore suggested, including wheelchairs powered by electrical drive units.
Various types of control systems have been heretofore suggested for controlling application of drive to the wheels of a powered wheelchair, with a joy-stick being often utilized as the control actuator to be manipulated by the user.
While joy-stick type controls for powered wheelchairs have extended self-propelled use of wheelchairs to some severely handicapped persons, such powered wheelchairs have not proved to be entirely satisfactory for use by at least some groups of potential users, including, for example, persons having sufficient use of their hands and/or arms to enable that user to at least partially manually propel the wheelchair by application of force to the hand rims connected to the main wheels thus affording the user satisfaction and/or exercise. In addition, powered wheelchairs are most often quite heavy and/or cumbersome, and joy-stick type controlled power wheel chairs have been found by at least some users to be more difficult to maneuver in close quarters.
Wheelchairs have also heretofore been configured so as to be foldable, or collapsible, to facilitate transporting and/or storage, and some such wheel chairs have been provided with power units at least some components of which have been removable (see, for example U.S. Pat. Nos. 3,770,073 and 3,064,744).
A power-assisted wheelchair for use by a partially disabled person having sufficient use of hands and/or arms to enable some application of force to the hand rims of the wheelchair to cause energization of electric motors by sensing displacement of the hand rims relative to the drive wheel has been heretofore suggested (see U.S. Pat. Nos. 4,050,533, 4,125,169 and 4,422,515). Such wheelchairs, however, have not proved to be entirely satisfactory, and improvements in such wheelchairs are therefore still desired and/or needed.
SUMMARY OF THE INVENTION
This invention provides an improved wheelchair and, more particularly, an improved wheelchair having a power unit that provides a power-assist which is activated when the user exerts force on the hand rims of the wheelchair in a manner directed toward manual propulsion of the wheelchair by the user.
The power unit includes an electric motor drivingly engagable with each main wheel of the wheelchair, with motor energization being controlled by a control signal that is generated in response to the user seated in the wheelchair exerting force on the associated hand rim in an attempt to manually propel the wheelchair. Structure and feedback circuitry are also provided to enhance the efficiency of the power assist provided, and the power unit is removable to facilitate folding up of the wheelchair when not in use.
It is therefore an object of this invention to provide an improved wheelchair.
It is another object of this invention to provide an improved wheelchair having a power-assist unit.
It is still another object of this invention to provide an improved power assisted wheelchair having an electrical power unit capable of assisting manual propelling of the wheelchair by the user.
It is yet another object of this invention to provide an improved power-assisted wheelchair having an electric motor energized by a control signal that is generated when the user applies force to a hand rim of the wheelchair in an attempt to propel the wheelchair.
It is yet another object of this invention to provide an improved power-assisted wheelchair that includes structure and feedback circuitry for enhancing the efficiency of operation of the wheelchair.
It is yet another object of this invention to provide an improved power-assisted wheelchair that is configured to allow removal of the power unit and folding of the wheelchair when not in use.
With these and other objects in view, which will become apparent to one skilled in the art as the description proceeds, this invention resides in the novel construction, combination, and arrangement of parts substantially as hereinafter described, and more particularly defined by the appended claims, it being understood that changes in the precise embodiment of the herein disclosed invention are meant to be included as come within the scope of the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings illustrate a complete embodiment of the invention according to the best mode so far devised for the practical application of the principles thereof, and in which:
FIG. 1 is a perspective view of the power-assisted wheelchair of this invention;
FIG. 2 is a partial rear view of the power-assisted wheelchair shown in FIG. 1;
FIG. 3 is a sectional view taken through lines 3--3 of FIG. 2;
FIG. 4 is a sectional view taken through lines 4--4 of FIG. 3;
FIG. 5 is an exploded perspective view illustrating the removable power unit positioned for normal use;
FIG. 6 is a rear view of the wheelchair illustrating the wheelchair with the power unit removed;
FIG. 7 is a rear view of the wheelchair similar to that of FIG. 6 but illustrating the wheelchair folded;
FIG. 8 is a side view of the wheelchair;
FIG. 9 is the sectional view taken through lines 9--9 of FIG. 8;
FIG. 10 is a block diagram illustrating the overall electrical and mechanical arrangement to provide power-assist;
FIG. 11 is a partial mechanical side view sketch illustrating rim centering;
FIGS. 12A, 12B, 12C and 12D, taken together, provide a schematic of the electrical circuitry shown in block form in FIG. 10;
FIG. 13 is a graph illustrating operation of the deadband circuit shown in FIG. 12A;
FIGS. 14A and 14B illustrate opposing face views of a capacitive sensor used for force sensing;
FIG. 15 is a schematic diagram of a strain gauge sensor illustrating an alternate embodiment for force sensing;
FIG. 16 is a block diagram illustration motion control forces of the power-assisted wheelchair; and
FIG. 17 illustrates typical signals generated utilizing the circuitry of FIG. 12.
DESCRIPTION OF THE INVENTION
As shown in FIGS. 1 through 9, wheelchair 20 conventionally includes frame 22 having spaced side portions 23 and 24, and a seat 25 and back support 26 extending between frame side portions 23 and 24. In addition, an arm rest 28 is provided at each of the frame portions 23 and 24 above seat 25 and forwardly of back support 26, and a handle 29 is provided at each of the frame portions 23 and 24 above and rearwardly of back support 26 to facilitate movement of the wheelchair by a person not then seated therein.
A drive wheel 30 is rotatably mounted outwardly of each side portion of frame 22 by wheel mount 31 with each drive wheel having spokes 32 extending to hub 33. Handrim 34 is connected with each drive wheel 30 by means of connecting flexible spacers 35 with each handrim also being connected by means of spokes 36 to central rim portion 37 at hub 33. With this arrangement, handrim 34 can be displaced slightly (no more than about two degrees) with respect to the associated drive wheel.
A front, or caster, wheel 38 is rotatably mounted on horizontal pin 39 in forked mount 40, with each mount having an upstanding vertical shaft 41 received in vertical socket 42 at the front edge of each side portion of frame 22 to thus enable the guide wheels to freely rotate about both a horizontal axis and a vertical axis, as is conventional.
Power assist is provided for wheelchair 20 by means of power unit 44 mounted on wheelchair 20 between drive wheels 30, with the power unit preferably being removable to allow the wheelchair to be folded when not in use. As brought out more fully hereinafter, power unit 44 is continuously drivingly connected to each drive wheel 27 through geared transmission 46, as best illustrated in FIGS. 3 and 4. Geared transmission 46 preferably a three-stage geared transmission having a 59:1 step-down ratio, and includes drive gear 47 which continuously meshes with gear 48 when power unit 44 is positioned for normal operation in wheelchair 20.
Power unit 44 is shown positioned for normal operation in FIGS. 1 through 4, and FIGS. 3, 4 and 5 illustrate drive gear 47 in continuous engagement with gear 48 (connected with an associated drive wheel 30) when the power unit is in normal operating position at wheelchair 20.
As best shown in FIGS. 3 and 4, power unit 44 includes a casing 49 having a pair of electric motors 50 therein each of which is offset with respect to the axis of rotation of drive wheels 30 (gear 48 rotates about the axis of rotation of both drive wheels 30) so that the drive gear 47, connected with motor drive shaft 51 of each motor 50, engages each gear 48 (with engagement of one gear 47 to its associated gear 48 being at the side opposite to that of engagement of the other gear 47 with its associate gear 48). Casing 49 of power unit 44 also has a pair of batteries 52 therein, each of which is connected with a different one of motors 50.
As indicated in FIGS. 1 and 2, when wheelchair 20 is in normal operating position, frame portions 23 and 24 are spaced from one another so that the seat 25 and back 26 fully extend therebetween. When the wheelchair has a foldable configuration (it is, of course, not necessarily foldable, although normally preferred) the seat and back are made of readily foldable material such as padded leather, canvas, or vinyl, for example). When unfolded, cross-braces 54 and links 55 are utilized to maintain the wheelchair in this position.
In addition, buckles, or similar fasteners, 57 on casing 49 and frame 22 are utilized to releasably maintain power unit 44 in normal operating position at wheelchair 20, and, as illustrated in FIG. 5, guides 58 in casing 49 engage projections 59 on the side portion of frame 22 when the power unit is inserted with the lower rear power unit receiving area of wheelchair 20, and mounting pins 60, attached to the side portions of frame 22, are received as apertures 61 in outstanding arms 62 of casing 49 to provide precise mounting of power unit 44 to insure mating of gears 47 and 48 when power unit 44 is in operating position in wheelchair 20.
As brought out above, it is preferred that wheelchair 20 be configured for folding. In addition, it is desirable that power unit 44 be removable from wheelchair 20 (regardless of whether configured for folding). To remove the power unit from the wheelchair, the buckles are unbuckled, and the power unit pulled rearwardly (which disengages gears 47 and 48). If the wheelchair has a foldable configuration, the wheelchair is ready to be folded, as indicated in FIG. 6, after removal of the power unit. When folded, as indicated in FIG. 7, the wheelchair is compact, and may be readily transported and/or stored.
As also best shown in FIGS. 3 and 5, electrical connections 63 are also provided at one side of casing 49 to facilitate connection of switches 64 with the electronic circuitry within casing 49. As shown in FIGS. 1 and 2, off-on switches 65, circuit breaker 66, and a battery recharging plug 67 are also provided at the rear of casing 49.
Power unit 44 is configured so that each drive wheel is powered independently of the other with the power assist provided by power unit 44 to each drive wheel 30 being activated by applying force to the handrim 34 associated with that drive wheel. The amount of assist provided may be adjustably controlled by a user by means of switches 64 which are preferably mounted on switch mount 68 on one arm 28. It is to be realized that a separate switch 66 is provided for controlling the amount of assist provided to each drive wheel 30, with the switches being preferably mounted on the same arm, as indicated in FIG. 1 (but the switches could, if desired, be mounted on each arm adjacent to the drive wheel to be controlled).
Each drive wheel is independently driven and controlled, and the mechanical/electrical arrangements for driving each drive wheel are identical with one such arrangement being illustrated by the block diagram of FIG. 10.
As indicated in FIG. 10, a rim centering unit 69 is provided to assure initial positioning of handrim 34 relative to drive wheel 30. When a user seated in wheelchair 20 applies force on handrim 34 in a direction toward propelling the wheelchair in either direction of rotation of the drive wheel, this causes the handrim to be rotationally displaced from its initial position relative to the associated drive wheel and this displacement is sensed by torque sensor 70 and an electrical signal is generated by the torque sensor. The electrical signal thus generated is coupled, preferably through slip rings 71, to deadband circuit 72 within casing 49, and then to gain control 73 (gain control 73 has user actuatable switch 66 connected therewith), and the resulting user developed force signal is then coupled to signal combiner unit 74, which also receives velocity and acceleration feedback signals.
One output from signal combiner unit 74 is coupled through rectifier 75 and switched amplifier circuit 76 to pulse width modulator 77, the output from which is coupled to motor drive unit 78. Drive unit 78 energizes electric motor 50 to rotate motor shaft 51 to cause rotation of drive wheel 30 through geared transmission 46. The sensed output from signal combiner unit 74 is also coupled to direction sensor unit 80, one output of which is coupled to motor drive unit 78 and another output of which is coupled to switched amplifier 76.
A tachometer 82 senses rotation of drive shaft 51 of motor 50, preferably by optical encoding. The pulses provided are processed by tachometer processor unit 83 to generate a velocity feedback signal which is coupled to signal combining unit 74, with tachometer processor unit 83 also providing an output signal to differentiator 84, which provides an acceleration feedback signal to signal combiner unit 74.
A feedback output from motor drive unit 78 is coupled to current to voltage converter 86, the output from which is coupled through current filter 87 to switched amplifier 76, and through current filter 87 and current limiter 88 back to motor drive unit 78.
Mechanical rim centering unit 69 is illustrated in FIG. 11. As indicated, main hub 33 of drive wheel 30 has a pair of upstanding pins 90 mounted thereon. Center portion 37 of the rim has one end of bar, or beam spring 91 mounted thereon, with the other end of bar spring 91 being forked and having a roller bearing 92 mounted thereon by pin 93.
The bar, or beam, spring urges the roller bearing toward the drive wheel and thus engagement with pins 90 on the drive wheel. Engagement of the roller bearing with both pins 90 maintains the handrim assembly at a centered initial position with respect to the drive wheel whereby the handrim is not displaced with respect to the drive wheel by user force being exerted thereon.
Even though the handrim is permitted to move a maximum of less than two degrees with respect to the drive wheel in either direction, it is the center one-fourth degree that is most critical. It is impractical to build a spring system with zero hysteresis so a mechanical system to automatically center the rim is useful.
Due to the maintained mechanical centering offset by use of pins 90 (a V-shaped detent in the drive wheel could also be used), relatively large forces are needed at first, then very little force is needed once the roller has rolled nearly out of pin engagement. The resistance force on the handrim generated by the pins and roller are, of course, in addition to the force generated by the springiness of the members that connect the handrim assembly to the wheel. Spring force is, of course, directly proportional to displacement. This means that an "S" curve is added to the straight line curve of the spring.
The resulting curve has been tailored so that a force of at least about 4 ounces is needed to cause sufficient displacement of the handrim relative to the drive wheel to effect the onset of power assist (to fully energize the motor to the limits of the gain setting requires 160 ounces). The motor, when energized, will provide power assist only to the extent that has been then set by the gain control. The force curve attempts to produce the maximum controllability at slow speeds while not interfering with the force amplification function once the wheelchair is moving rapidly along an obstacle-free path.
The centering mechanism shown in FIG. 11 may be utilized in conjunction with an electrical system for removing the effects of hysteresis (or either may, of course, be used alone). If used together, any error introduced by one could be offset by the other--for example, an imperfection in the roller bearing might produce a slight offset in mechanical centering.
Overcoming of hysteresis electrically is accomplished through electronic deadband circuit 72, as shown in FIG. 12A. This circuit is utilized at the input to the power unit 40 circuitry within casing 49 to receive the electrical signals generated by handrim mounted torque sensor 70. Deadband circuit 72 includes a pair of op-amps 90 and 96 wired as complementary perfect diodes. Op-amps 95 and 96 receive the output signal from the conditioning circuitry of torque sensor 70, and the outputs from op-amps 95 and 96 are commonly connected to the negative input of op-amp 97 which supplies an output signal to signal combiner unit 74 (through gain control unit 73).
A deadband is introduced around the 5 volt reference point by means of two 3.3M ohms bias resistors which introduce a deadband in which no signal is coupled to the signal combiner unit (and hence to the motor drive unit). The deadband is small, and, as indicated in FIG. 13, is on the order of +/- 0.15 volts out of a total input swing of +/- 3.5 volts.
Torque sensor 70 produces a directional voltage or current proportional to the force applied to the handrim in the direction to cause rotation of the associated drive wheel (subject to some deviation due to use of hysteresis compensating structure and/or circuitry).
Torque sensor 70 is preferably a capacitance torque sensor that produces a relatively large signal whenever the handrim is deflected a degree or less. The capacitor plates, or halves, for torque sensor 70, shown in FIGS. 14A and 14B, are preferably formed by printed circuit boards 99 and 100 and are mounted in the hub adjacent to one another as illustrated in FIG. 9. The capacitor is formed by narrow, radially extending segments 102 and 103, respectively, printed on boards 99 and 100. The printed circuit boards 99 and 100 are mounted in fixed relationship to the central portion of rim 37 and the drive wheel hub 33, respectively.
As shown in FIGS. 14A and 14B, the radially extending segments 102 and 103 are oriented in an arc extending from the central axis of rotation 105 of drive wheels 30. In operation, the printed circuit boards are closely adjacent and facing each other, as indicated in FIG. 9, so that rotation of the handrim occurs, relative to the drive wheel, about the central axis of rotation 105 and this causes rotation of one printed circuit board relative to the other. This, in turn, causes a change of capacitance due to the change of alignment between the radially extending elements on the two halves of the capacitor.
The central portion of the handrim is preferably connected to the drive wheel hub by a pair of stiff beam springs 106 close to the axle. These springs flex slightly when the handrim is rotated by torque applied to the handrim, and this causes the springs to deflect slightly to effect radial displacement of the alignment between the two circuit boards. As the radially extending segments rotate relative to each other, the capacitance between the two boards changes.
The capacitance is actually divided into two components. Torque in one direction causes an increase in one capacitive component and a decrease in the other capacitive component. The difference in capacitance is electronically conditioned by conditioning circuit 107, as shown in FIG. 12A, to provide a measure of the input handrim force. As shown, the sensing components of capacitor torque sensor 70 (indicated by capacitors 109 and 111 in FIG. 12A) are driven by oscillator 112 (located on one of the capacitor printed circuit boards). Oscillator 112 is a square wave generator that includes three inverters 114, the output of the last of which is coupled to flip-flop buffer 115. The direction of torque is detected by diodes 117 and 118 providing a two-sided input to operational amplifier 120.
The entire sensor unit (including the capacitive sensor elements and the conditioning circuitry) is located within the hub of the drive wheel. The power to drive the unit is brought in through slip rings 71 at 10 volts, and the square wave oscillation is buffered by a flip-flop 93 to insure that the square wave is completely symmetrical. This results in equal signal strength for equal torque in both the clockwise and counter-clockwise directions. The output from the operational amplifier is a relatively large signal, up to +/- 3.5 volts referenced to a 5 volt level, that is easily transmitted from the hub by slip rings without appreciable noise or distortion.
Although not now preferred, a strain gauge arrangement 122, as shown in FIG. 15, may also be utilized as the rim-force torque sensor. In this embodiment, the hand rim is attached to the drive wheel by four rigid spokes, and a set 123 of strain gauges (as indicated in FIG. 15) is placed on each spoke so that two strain gauges 125 and 126 are placed on the opposite side of each of the four spokes to produce a larger change in the resistance of the gauges, and the pairs of strain gauges are connected in a bridge circuit configuration to obtain the largest possible signal output (the signal strength, however, is not as large as may be realized using the capacitor torque sensor).
The strain gauges, when so connected and powered as indicated in FIG. 15, produce a signal whenever the rim is deflected slightly in either direction. Thus, force is detected without allowing, or necessitating, noticeable movement of the handrim relative to the associated drive wheel, with the actual motion being on the order of +/- one degree. The output signal (due to the force sensed by the strain gauges) as well as supplied power, coupled through slip rings 71.
The user force signal generated by torque sensor 70 is coupled through gain control unit 73, as brought out above. This gain control unit is shown in greater detail in FIG. 12A. As shown, a pair of digital-to-analog converters 128 and 129 are utilized (D/A converter 128 is connected with internal gain controls to allow the gain to be adjusted with no access to the user, while control switch 66 is connected with D/A unit 129 to allow user gain adjustment), with the output from D/A convertor 128 being coupled through OP-amp 131 to D/A convertor 129 and the output from D/A converter 129 being coupled to signal combiner unit 74 through op-amp 132. The user can select any one of four settings (equal to about 25%, 50%, 75% and 100%) of available assist power and the resultant user generated force signal is coupled to signal combiner unit 74.
As brought out above, power assist is provided when the user applies force to the handrim in a direction to propel the associated drive wheel in either direction. This force signal, as shown by the block diagram of FIG. 10, is rectified and a pulse width modulated signal produced and applied to the motor drive unit to energize the motor to drive the associated drive wheel.
It has been found that it is difficult to provide effective power assist by simply amplifying the force sensed by torque sensor, particularly when attempting to maneuver at slow speeds. Through the use of a plurality of feedback units, the power assist becomes effective and the feedback was found to the power assist in providing the desired maneuverability. These circuits are shown in the block diagram of FIG. 10, and are shown in greater detail in the schematic diagram of FIGS. 12B, 12C and 12D.
As shown in FIG. 12B, signal combiner unit 74 includes OP-amp 134 which receives the output signal from gain control circuitry 73 (on lead a as shown in FIGS. 12A and 12B) as well as a velocity feedback signal (through a 1.5 m ohm resistor) and an acceleration feedback signal (through a 3 m ohm resistor). Positioned feedback is also realized by the tachometer since it consistently monitors the motor shaft.
The output from OP-amp 134 is coupled through op-amp 36 to direction sensor unit 80 (on lead b as shown in FIGS. 12B and 12C), and to full wave rectifier 75 (formed by diodes 138 and 139) through op-amp 141, with the output from rectifier 75 being coupled through op-amp 143 to switched amplifier circuitry 76 (on lead c as shown in FIGS. 12B and 12C).
Tachometer 82 preferably senses the rotation of motor shaft 52 by conventional optical encoding through optical sensing of indicia (such as stripes on the motor shaft). The tachometer develops dual electrical signals indicative of indicia sensing, and these electrical signals are coupled, as indicated in FIG. 12B, through current sensing field effect transistors (FETS) 145 and 146 of tachometer processor 83 to exclusive OR gates 148 and 149, the outputs of which are coupled to flip-flop (F/F) 151. The signals supplied are square wave pulse trains that have leading or lagging phases depending upon the direction of tachometer sensed rotation.
In addition, the output for exclusive OR gate 149 is coupled to frequency-voltage converter 151 (converter 151 includes exclusive OR gate 153, a CMOS analog switch (designated by the symbol X) and op-amps 155 and 156). The outputs from F/F 151 are coupled to bipolar signal converter 158 (converter 158 includes a pair of CMOS analog switches again designated by the symbol X), which receive a negative output only from frequency-voltage converters 151, and op-amp 160.
The output from converter 158 is coupled from the output of op-amp 160 as an analog signal that is indicative of velocity, and provides the velocity feedback signal to signal combiner unit 74. The analog signal coupled from op-amp 160 is also coupled to differentiator circuity 84, which circuitry includes op-amp 162. The output from op-amp 162 provides the acceleration feedback signal to signal combiner unit 74.
As shown in FIG. 12C, direction sensor 80 (receiving the output from op-amp 136 on lead b) includes a pair of comparators 164 and 165. Comparator 164 provides outputs to direction logic NOR gates 167 and 168 and to back-up logic NOR gate 170 (on lead e as shown in FIGS. 12C and 12D). Comparator 165 provides outputs to direction logic NOR gates 172 and 173 and to back-up logic NOR gate 170 (on lead f as shown in FIGS. 12C and 12D).
As also shown in FIG. 12C, switched amplifier circuitry 76 includes op-amp 175 and a CMOS analog switch (indicated by the symbol x), with the switch being connected with the outputs from direction sensor op-amps 164 and 165 through diodes 177 and 178 (and through lead d as shown in FIGS. 12C and 12D).
The output from switch amplifier 76 is coupled to comparator 180 of pulse width modulator 77. The second input to comparator 180 is provided by the output from comparator 182. The output from comparator 180 is coupled to comparator 184, the output of which is coupled to logic NOR gates 168 and 172 (on lead g as shown in FIGS. 12C and 12D).
A feedback output from motor drive unit 78 (FIG. 12D) is coupled (on lead i as shown in FIGS. 12C and 12D) to current feedback op-amp 186 of current voltage converter 86. The output of current to voltage converter 86 is coupled from op-amp 186 to comparator 188 of current filter circuitry 87. The output of comparator 188 is coupled to switch amplifier circuitry 76 and to op-amp 190 of current limiter 88. The output from op-amp 190 is coupled to logic NOR gates 167 and 173 (on lead h as shown in FIGS. 12C and 12D).
As also shown in FIG. 12C, the +5 volt power is developed by regulator unit 192 to the +10 volt power developed by regulator unit 194 (FIG. 12D). Regulator unit 194 is connected with battery 52 (which battery may be rechargeable as also indicated in FIG. 12D). In addition, battery 52 is connected with FET 196 and provide safety by preventing undesired motor drive.
As shown in FIG. 12D, motor drive unit 78 includes a plurality of current sensing FETS 200 and 201, and FETS 198 and 199 are connected with invert buffers 203 and 204 (formed by FETS 206 and 207) and With FETS 200 and 201 being connected with buffers 209 and 210 (formed by transistors 212 and 213). As shown, each buffer and invert buffer is connected with a different one of logic NOR gates 167, 168, 172 and 173.
The motor control force for the power-assisted wheelchair as described herein is set forth in FIG. 17 and further explains the algorithm utilized. While shown hard-wired, it is to be realized that a microcomputer could also be utilized to provide control as set forth herein.
As can be realized from the foregoing, the motor drive circuitry utilizes the sensor output (as adjusted by the gain control) in conjunction with the plurality of feedback signals to provide drive to each drive wheel of the wheelchair.
The wheelchair motor is primarily intended to produce torque to amplify the torque that the patient is able to generate. The motor is not supposed to achieve some particular velocity that the patient has requested. Motor torque is a function of current, while motor speed (in an unloaded or ideal motor) is a function of voltage. Consequently, it is motor current that is the important controlled quantity, rather than motor voltage. To summarize the control electronics, the handrim torque and motor positional feedback produce a final analog drive signal to the motor that represents the torque that is desired from the motor. The actual motor drive circuitry uses this signal as a reference to produce the requested torque.
The motor drive circuit is basically a constant current generator. If the drive circuit can produce the requested current, then the desired torque will have been delivered. To make the motor circuit efficient, the actual motor drive is accomplished using pulse width modulation, rather than a simple analog motor drive. Current sense FET transistors are used to sense when the pulses are applied to the motor. The pulses are integrated to produce a voltage that represents the average drive current. This feedback goes to the negative input of the constant current amplifier where it cancels out the positive input drive signal when the desired motor current is reached.
Negative acceleration feedback has proved to be effective in preventing instability. The feedback is inserted just ahead of the full-wave rectifier circuit and diminishes the amplitude of a large handrim input request.
Damping the oscillation produced by grabbing the handrim was also a problem solved by providing feedback. Unsigned negative acceleration feedback was ineffective. The reason was that, when the handrim was grasped firmly, the oscillation would attempt to accelerate the wheel equally in both directions. This resulted in a constant acceleration feedback which did nothing to suppress the oscillation.
By developing a signed acceleration signal, the sudden reversal of direction produces an extreme change in acceleration, as it should to cancel the input signal. The behavior of the feedback signals is graphed in FIG. 16. The acceleration trace is plotted on the top line. First, successive pushes on the handrim (seen as downgoing blips) accelerate the wheel to a high velocity. Then the wheel is grabbed firmly. This is seen as a huge positive signal that opposes the changing velocity as shown in the third trace. The second trace shows the unsigned motor current during these events. It can be seen that the highest motor current occurs when the handrim is grabbed. The large surges of current that follow the handrim stopping are actually in such a phase to suppress the oscillation as can be seen from the velocity signal reduction.
A disadvantage of having the large-ratio gear drive is that the gears dissipate energy and make the wheelchair coast poorly. After the user has pushed on the handrims to achieve the speed desired, the wheelchair will coast to a stop quickly because its energy of momentum is quickly dissipated in the gear train. This problem is corrected using positive velocity feedback.
Once a speed is achieved, the speed is maintained for a while by the velocity feedback that is inserted at the input to the summing amplifier. The length of the simulated coast is determined by the gain of the velocity feedback loop. If the feedback were amplified too much, the chair would accelerate rather than just coast. Instead, a feedback gain is selected that produces less drive than needed to maintain (or increase) the present speed. As a result, the motor drive and speed slowly decline simulating a coasting effect. Specifically, the motor speed feedback is set by the 15M ohm resistor at the input to the amplifier input.
The motor direction is determined by a combination of information from the handrim and the signed velocity feedback. These two sources of data are summed to produce a resultant motor direction. A logic system turns on the respective transistors of the motor drive bridge circuit to establish the correct direction. A back-up logic gate insures that only one direction is selected at once.
The logic system generates three basic logic signals: forward, reverse, and "zero switch". "Zero switch" is a logic level that described when there should be no motor current flowing. It is used to suppress the constant motor current drive amplifier to prevent drift. These signals can be seen at the bottom of FIG. 8 which illustrates the basic feedback and motor current levels.
This same velocity maintenance algorithm also serves to allow the wheelchair to be pushed like a conventional chair. Once a desired velocity has been reached, the feedback will allow it to gradually decrease. Without the feedback and the electric motor, the wheelchair behaves as though it were being pushed through deep sand because it will not coast at all.
With the gear train permanently engaged, dynamic braking is realized. The purpose is to provide "power brakes" so that the user does not have to rely on his own strength to stop the chair. If the gear train were disengaged by a ratchet or a clutch to provide a coasting characteristic, then some method would have been needed to reengage the gear train reliably under this condition.
Dynamic braking in the wheelchair is achieved primarily by the active braking initiated by the user. Like any normal wheelchair, this one can be slowed down by putting hand pressure on the hand rims. This braking is dynamic because the braking is actively assisted by the motor. This dynamic braking function is altered by the negative acceleration feedback. Suppose, for example, the user starts down a steep ramp and begins to accelerate rapidly. The rapid increase in velocity is discouraged by the negative acceleration feedback. But more importantly, if the user reacts by grabbing the handrims, the negative feedback will prevent the chair from decelerating so rapidly that it throws the user from the chair.
The velocity feedback, being positive, doesn't prevent the increase in velocity that occurs while coasting down a ramp. Its purpose is to make the wheelchair behave like a normal chair, including a coasting characteristic. As the wheelchair goes faster, friction loss from the gear-train would automatically depress speed, but the coasting algorithm offsets this loss.
As can be appreciated from the foregoing, this invention powers an improved power-assisted wheelchair.
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A power-assisted wheelchair is disclosed that is particularly well suited for use by a person capable of exerting some hand/arm force in attempting to propel the wheelchair while seated therein, but incapable of exerting sufficient force, at least in some instances, to achieve satisfactory overall non-assisted operation of the wheelchair. Power-assist is provided by an electrical power unit that includes a motor for driving each main wheel of the wheelchair, with the power unit being removable to facilitate folding of the wheel chair when not in use. Motor energization is initiated when the user exerts force on the hand rims, connected with the drive wheels, in an attempt to propel the wheelchair. Displacement of the handrim relative to the associated drive wheel caused by the user exerted force is sensed and an electrical signal is produced to cause motor energization, with structure and feedback circuitry also being included for enhancing the efficiency of the power assist thus provided.
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FIELD OF THE INVENTION
This invention relates to medical apparatus in general, and more particularly to anatomical visualization and measurement systems.
BACKGROUND OF THE INVENTION
Many medical procedures must be carried out at an interior anatomical site which is normally hidden from the view of the physician. In these situations, the physician typically uses some sort of scanning device to examine the patient's anatomy at the interior site prior to, and in preparation for, conducting the actual medical procedure. Such scanning devices typically include CT scanners, MRI devices, X-ray machines, ultrasound devices and the like, and essentially serve to provide the physician with some sort of visualization of the patient's interior anatomical structure prior to commencing the actual medical procedure. The physician can then use this information to plan the medical procedure in advance, taking into account patient-specific anatomical structure.
In addition to the foregoing, the physician can also use the information obtained from such preliminary scanning to more precisely identify the location of selected structures (e.g., tumors and the like) which may themselves be located within the interior of internal organs or other internal body structures. As a result, the physician can then more easily "zero in" on such selected structures during the subsequent medical procedure.
Furthermore, in many cases, the anatomical structures of interest to the physician may be quite small and/or difficult to identify with the naked eye. In these situations, preliminary scanning of the patient's interior anatomical structure using high resolution scanning devices can help the physician locate various structures of interest during the subsequent medical procedure.
In addition to the foregoing, scanning devices of the sort described above are frequently also used in purely diagnostic procedures. For example, scanning devices of the sort described above might be used to look for stenosis in a blood vessel, or the buildup of plaque in a blood vessel, or a thinning of the aorta wall, etc.
In general, scanning devices of the sort described above tend to generate two-dimensional (i.e., "2-D") images of the patient's anatomical structure. In many cases, the scanning devices are adapted to provide a set of 2-D images, with each 2-D image in the set being related to every other 2-D image in the set according to some pre-determined relationship. For example, CT scanners typically generate a series of 2-D images, with each 2-D image corresponding to a specific plane or "slice" taken through the patient's anatomical structure. Furthermore, with many scanning devices, the angle and spacing between adjacent image planes or slices is very well defined, e.g., each image plane or slice may be set parallel to every other image plane or slice, and adjacent image planes or slices may be spaced a pre-determined distance apart. By way of example, the parallel image planes might be set 1 mm apart.
In a system of the sort just described, the physician can view each 2-D image individually and, by viewing a series of 2-D images in proper sequence, can mentally generate a three-dimensional (i.e., "3-D") impression of the patient's interior anatomical structure.
Some scanning devices include, as part of their basic system, associated computer hardware and software for building a 3-D database of the patient's scanned anatomical structure using a plurality of the aforementioned 2-D images. For example, some CT and MRI scanners include such associated computer hardware and software as part of their basic system. Alternatively, such associated computer hardware and software may be provided independently of the scanning devices, as a sort of "add-on" to the system; in this case, the data from the scanned 2-D images is fed from the scanning device to the associated computer hardware and software in a separate step. In either case, a trained operator using such apparatus can create a set of scanned 2-D images, assemble the data from these scanned 2-D images into a 3-D database of the scanned anatomical structure, and then generate various additional images of the scanned anatomical structure using the 3-D database. This feature has been found to be a very powerful tool, since it essentially permits a physician to view the patient's scanned anatomical structure from a wide variety of different viewing positions. As a result, the physician's understanding of the patient's scanned anatomical structure is generally greatly enhanced.
In addition, scanning systems of the sort described above often include hardware and/or software tools to allow measurements to be made of the patient's scanned anatomical structure. By way of example, many of these systems let a physician overlay lines on an image of the patient's anatomical structure, and then calculate the length of these lines so as to indicate the size of the structure being viewed.
While the 2-D slice images generated by the aforementioned scanning devices, and/or the 3-D database images generated by the aforementioned associated computer hardware and software, are generally of great benefit to physicians, certain significant limitations still exist.
For one thing, with current systems, each scanned 2-D slice image is displayed as a separate and distinct image, and each image generated from the 3-D database is displayed as a separate and distinct image. Unfortunately, physicians can sometimes have difficulty correlating what they see on one image with what they see on another image. By way of example but not limitation, physicians can sometimes have difficulty correlating what they see on a particular scanned 2-D slice image with what they see on a particular image generated from the 3-D database.
For another thing, in many situations a physician may be viewing images of a patient's scanned anatomical structure in preparation for conducting a subsequent medical procedure in which a prosthetic device must be fitted in the patient. In these situations it can be relatively difficult and/or time-consuming for the physician to accurately measure and record all of the anatomical dimensions needed for proper sizing of the prosthetic device to the patient. By way of example, in certain situations a patient may develop an abdominal aortic aneurysm ("AAA") in the vicinity of the aorta's iliac branching, and repair or replacement of the affected vascular structure with a prosthetic device may be indicated. In this case it is extremely important for the physician to determine, prior to commencing the procedure, accurate length and cross-sectional dimensions for each affected portion of blood vessel so as to ensure proper sizing of the appropriate prosthetic device to the patient. Unfortunately, it can be difficult and/or impossible to make accurate anatomical measurements with existing visualization systems. This has proven to be particularly true when dealing with anatomical structures which extend along a tortuous path and/or which have a complex and varied branching structure, e.g., blood vessels.
Furthermore, in many cases it may be desirable to provide a physician with a particular oblique view of a specified portion of a patient's anatomical structure. For example, it may be desirable to provide a physician with a view taken perpendicular to the length of a blood vessel, with that view being taken at a very specific location along that blood vessel. Such a view might be desired for comprehensional and/or measurement purposes. Unfortunately, it can be difficult and/or impossible to accurately generate such a view using existing visualization systems.
In addition to the foregoing, in many situations a physician may be interested in accurately calculating a volume associated with a specific part of a patient's anatomy. By way of example but not limitation, a physician might wish to track the volume of a thrombus in an aorta over time, or the size of a tumor during chemotherapy, etc. Unfortunately, it can be difficult and/or impossible to accurately make such a calculation using existing visualization systems.
OBJECTS OF THE INVENTION
Accordingly, one object of the present invention is to provide an improved anatomical visualization and measurement system for visualizing and measuring anatomical structures.
Another object of the present invention is to provide an improved anatomical visualization and measurement system wherein a scanned 2-D slice image can be appropriately combined with an image generated from a 3-D database so as to create a single composite image.
Another object of the present invention is to provide an improved anatomical visualization and measurement system wherein a marker can be placed onto a 2-D slice image displayed on a screen, and this marker will be automatically incorporated, as appropriate, into a 3-D computer model maintained by the system, as well as into any other 2-D slice image data maintained by the system.
Still another object of the present invention is to provide an improved anatomical visualization and measurement system wherein a margin of pre-determined size can be associated with a marker of the sort described above, and further wherein the margin will be automatically incorporated into the 3-D computer model, and into any other 2-D slice image data, in association with that marker.
Yet another object of the present invention is to provide an improved anatomical visualization and measurement system wherein the periphery of objects contained in a 3-D computer model maintained by the system can be automatically identified in any 2-D slice image data maintained by the system, and further wherein the periphery of such objects can be highlighted as appropriate in 2-D slice images displayed by the system.
Another object of the present invention is to provide an improved anatomical visualization and measurement system wherein patient-specific anatomical dimensions such as length and/or cross-sectional dimensions can be quickly, easily and accurately determined.
Still another object of the present invention is to provide an improved anatomical visualization and measurement system which is particularly well adapted to determine patient-specific anatomical dimensions for structures which have a tortuous and/or branching configuration, e.g., blood vessels.
And another object of the present invention is to provide an improved anatomical visualization and measurement system wherein an appropriate set of scanned 2-D images can be assembled into a 3-D database, information regarding patient-specific anatomical structures can be segmented from the information contained in this 3-D database, and this segmented information can then be used to determine anatomical features such as a centerline for the anatomical structure which has been segmented.
Still another object of the present invention is to provide an improved anatomical visualization and measurement system which is able to easily and accurately present a physician with a particular oblique view of a specified portion of a patient's anatomical structure, e.g., a view taken perpendicular to the length of a blood vessel, with that view being taken at a very specific location along that blood vessel.
Another object of the present invention is to provide an improved anatomical visualization and measurement system wherein patient-specific anatomical volumes can be quickly, easily and accurately determined.
And another object of the present invention is to provide an improved anatomical visualization and measurement system wherein an appropriate set of scanned 2-D images can be assembled into a 3-D database, information regarding patient-specific anatomical structures can be segmented from the information contained in this 3-D database, and this segmented information can then be used to calculate desired patient-specific anatomical volumes.
Another object of the present invention is to provide an improved method for visualizing and measuring anatomical structures.
And another object of the present invention is to provide an improved method wherein patient-specific anatomical dimensions such as length and/or cross-sectional dimensions can be quickly, easily and accurately determined.
Still another object of the present invention is to provide an improved method wherein an appropriate set of scanned 2-D images can be assembled into a 3-D database, information regarding patient-specific anatomical structures can be segmented from the information contained in this 3-D database, and this segmented information can then be used to determine anatomical features such as a centerline for the anatomical structure which has been segmented.
And another object of the present invention is to provide a method for easily and accurately presenting a physician with a particular oblique view of a specified portion of a patient's anatomical structure, e.g., a view taken perpendicular to the length of a blood vessel, with that view being taken at a very specific location along that blood vessel.
Yet another object of the present invention is to provide an improved method for quickly, easily and accurately determining patient-specific anatomical volumes.
SUMMARY OF THE INVENTION
These and other objects are addressed by the present invention, which comprises an anatomical visualization and measurement system comprising a first database which comprises a plurality of 2-D slice images generated by scanning an anatomical structure. These 2-D slice images are stored in a first data format. A second database is also provided which comprises a 3-D computer model of the scanned anatomical structure. This 3-D computer model comprises a first software object which is representative of the scanned anatomical structure and which is defined by a 3-D geometry database.
In one embodiment of the present invention, means are provided for selecting a particular 2-D slice image from the first database. Means are also provided for inserting a second software object into the 3-D computer model so as to augment the 3-D computer model. The second software object is also defined by a 3-D geometry database, and includes a planar surface. In this embodiment of the invention, the second software object is inserted into the 3-D computer model at the position which corresponds to the position of the selected 2-D slice image relative to the scanned anatomical structure. Means for texture mapping the specific 2-D slice image onto the planar surface of the second software object are also provided. Means are also provided for displaying an image of the augmented 3-D computer model so as to simultaneously provide a view of both the first software object and the specific 2-D slice image which has been texture mapped onto the planar surface of the second software object.
In another embodiment of the invention, the system comprises a first database which comprises a plurality of 2-D slice images generated by scanning an anatomical structure. These 2-D slice images are stored in a first data format. A second database is also provided which comprises a 3-D computer model of the scanned anatomical structure. This 3-D computer model comprises a first software object which is representative of the scanned anatomical structure and which is defined by a 3-D geometry database. In this second embodiment of the invention, means are also provided for inserting a second software object into the 3-D computer model so as to augment the 3-D computer model. The second software object is also defined by a 3-D geometry database, and includes a planar surface. Furthermore, means are also provided for determining the specific 2-D slice image which corresponds to the position of the planar surface of the second software object which has been inserted into the augmented 3-D computer model. In this embodiment of the invention, means are also provided for texture mapping the specific 2-D slice image corresponding to the position of that planar surface onto the planar surface of the second software object. In this embodiment of the invention, display means are also provided for displaying an image of the augmented 3-D computer model to a physician so as to simultaneously provide a view of the first software object and the specific 2-D slice image which has been texture mapped onto the planar surface of the second software object.
In each of the foregoing embodiments of the present invention, the 3-D geometry database may comprise a surface model.
Likewise, the system may further comprise means for inserting a marker into the first database, whereby the marker will be automatically incorporated into the second database, and further wherein the marker will be automatically displayed where appropriate in any image displayed by the system.
Also, the system may further comprise a margin of pre-determined size associated with the aforementioned marker.
Additionally, the system may further comprise means for automatically identifying the periphery of any objects contained in the second database and for identifying the corresponding data points in the first database, whereby the periphery of such objects can be highlighted as appropriate in any image displayed by the system.
Often, the scanned structure will comprise an interior anatomical structure.
In yet another form of the present invention, the visualization and measurement system may incorporate means for determining patient-specific anatomical dimensions, such as length and/or cross-sectional dimensions, using appropriate scanned 2-D image data. More particularly, the visualization and measurement system may include means for assembling an appropriate set of scanned 2-D images into a 3-D database, means for segmenting information regarding patient-specific anatomical structures from the information contained in the 3-D database, means for determining from this segmented information anatomical features such as a centerline for the anatomical structure which has been segmented, means for specifying a measurement to be made based on the determined anatomical feature, and means for calculating the measurements so specified.
In a more particular form of the present invention, the visualization and measurement system is particularly well adapted to determine patient-specific anatomical dimensions for structures which have a tortuous and/or branching configuration, e.g., blood vessels. In this form of the invention, the visualization and measurement system is adapted to facilitate (1) assembling an appropriate set of scanned 2-D images into a 3-D database; (2) segmenting the volumetric data contained in the 3-D database into a set of 3-D locations corresponding to the specific anatomical structure to be measured; (3) specifying, for each branching structure contained within the specific anatomical structure of interest, a branch line in the volumetric data set that uniquely indicates that branch structure, with the branch line being specified by selecting appropriate start and end locations on two of the set of scanned 2-D images; (4) calculating, for each branching structure contained within the specific anatomical structure of interest, a centroid path in the volumetric data set for that branching structure, with the centroid path being determined by calculating, for each scanned 2-D image corresponding to the branch line, the centroid for the branch structure contained in that particular scanned 2-D image; (5) applying a curve-fitting algorithm to the centroid paths determined above so as to supply data for any portions of the anatomical structure which may lie between the aforementioned branch lines, and for "smoothing out" any noise that may occur in the system; and (6) applying known techniques to the resulting space curves so as to determine the desired anatomical dimensions.
In still another form of the present invention, the visualization and measurement system may incorporate means for easily and accurately presenting a physician with a particular oblique view of a specified portion of a patient's anatomical structure, e.g., a view taken perpendicular to a blood vessel, at a very specific location along that blood vessel.
In another form of the present invention, the visualization and measurement system may incorporate means for more accurately measuring the dimensions of an anatomical structure by utilizing one or more oblique views taken along the length of that anatomical structure.
In yet another form of the present invention, the visualization and measurement system may incorporate means for determining patient-specific anatomical volumes using appropriate scanned 2-D image data. More particularly, the visualization and measurement system may include means for assembling an appropriate set of scanned 2-D images into a 3-D database, means for segmenting information regarding patient-specific anatomical structures from the information contained in the 3-D database, means for determining from this segmented information anatomical volumes from the anatomical structure which has been segmented, means for specifying a structure of interest, and means for calculating the volume of the specified structure.
The present invention also comprises an improved method for visualizing and measuring anatomical structures.
The present invention also comprises a method for calculating patient-specific anatomical dimensions using appropriate scanned 2-D image data. In one form of the present invention, the method comprises the steps of (1) assembling an appropriate set of scanned 2-D images into a 3-D database; (2) segmenting information regarding patient-specific anatomical structures from the information contained in the 3-D database, (3) determining for this segmented information anatomical features such as a centerline for the anatomical structure which has been segmented; (4) specifying a measurement to be made based on the determined anatomical feature; and (5) calculating the measurement so specified.
The present invention also comprises a method for easily and accurately presenting a physician with a particular oblique view of a specified portion of a patient's anatomical structure, e.g., a view taken perpendicular to a blood vessel, at a very specific location along that blood vessel.
The present invention also comprises a method for calculating patient-specific anatomical volumes using appropriate scanned 2-D image data. In one form of the present invention, the method comprises the steps of (1) assembling an appropriate set of scanned 2-D images into a 3-D database; (2) segmenting information regarding patient-specific anatomical structures from the information contained in the 3-D database, (3) determining from this segmented information volumes for the anatomical structure which has been segmented, (4) specifying a structure of interest, and (5) calculating the volume of the specified structure.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects and features of the present invention will be more fully disclosed or rendered obvious by the following detailed description of the preferred embodiments of the invention, which is to be considered together with the accompanying drawings wherein like numbers refer to like parts, and further wherein:
FIG. 1 is a schematic view showing a scanning device for generating a set of 2-D images of the anatomy of a patient;
FIG. 2 is a 2-D slice image corresponding to an axial slice taken through the abdomen of an individual;
FIG. 3 shows a series of data frames corresponding to 2-D slice images arranged in a parallel array;
FIG. 4 is a schematic view showing the scanning data contained within an exemplary data frame;
FIG. 5 shows scanning data stored in a first storage device or medium being retrieved, processed and then stored again in a second data storage device or medium;
FIG. 6 is a schematic view of a system for retrieving and viewing scanning data;
FIG. 7 is a schematic view of a unit cube for use in defining polygonal surface models;
FIG. 8 illustrates the data file format of the polygonal surface model for the simple unit cube shown in FIG. 7;
FIGS. 9A-9F illustrate a variety of menu choices which may be utilized in connection with the present invention;
FIG. 10 illustrates an image drawn to a window using the data contained in the 3-D computer model associated with the present invention;
FIG. 11 illustrates a 2-D slice image drawn to a window in accordance with the present invention;
FIG. 12 illustrates a composite image formed from information contained in both the 3-D computer model and the 2-D slice image data structure;
FIG. 13 is a schematic illustration showing the relationship between axial slices, sagittal slices and coronal slices;
FIG. 14 illustrates three different images being displayed on a computer screen at the same time, with a marker being incorporated into each of the images;
FIG. 15 illustrates a marker shown in an image generated from the 3-D computer model, with the marker being surrounded by a margin of pre-determined size;
FIG. 16 illustrates a 2-D slice image, wherein the periphery of an object has been automatically highlighted by the system;
FIG. 17 is a schematic illustration showing various anatomical structures on a 2-D slice image, where that 2-D slice image has been taken axially through the abdomen of a patient, at a location above the aortic/iliac branching;
FIG. 18 is a schematic illustration showing various anatomical structures on another 2-D slice image, where that 2-D slice image has been taken through the abdomen of the same patient, at a location below the aortic/iliac branching;
FIGS. 17A and 18A are schematic illustrations like those of FIGS. 17 and 18, respectively, except that segmentation has been performed in the 3-D database so as to highlight the patient's vascular structure;
FIG. 19 is a schematic illustration showing that same patient's vascular structure in the region about the aortic/iliac branching, with branch lines having been specified for the patient's aorta and two iliac branches;
FIG. 20 is a schematic illustration showing how the centroid is calculated for the branch structure contained in a particular scanned 2-D image;
FIG. 21 is a schematic illustration showing the tortuous centroid path calculated for each of the respective branch lines shown in FIG. 19;
FIG. 22 is a schematic illustration showing the space curve determined by applying a curve-fitting algorithm to two of the centroid paths shown in FIG. 21, whereby the structure between the branch lines is filled out and the centroid data "smoothed" through a "best fit" interpolation technique;
FIG. 23 is a flow chart illustrating how patient-specific anatomical dimensions can be determined from scanned 2-D image data in accordance with the present invention;
FIG. 24 is a schematic view showing an oblique slice polygon disposed perpendicular to the centerline of a blood vessel;
FIG. 25 is a cumulative sum table for calculating lengths along an anatomical structure;
FIG. 26 illustrates a centerline length calculation dialogue box drawn to a window in a display;
FIG. 27 illustrates a 3-D graphical icon which has been inserted into the 3-D model and which is visible on the display so as to show the portion of the centerline which has been specified by the physician for a length calculation;
FIG. 28 is a cumulative sum table for calculating volumes with respect to an anatomical structure;
FIG. 29 illustrates a volume calculation dialogue box drawn to a window in a display; and
FIG. 30 illustrates a 3-D graphical icon which has been inserted into the 3-D model and which is visible on the display so as to show the volume which has been specified by the physician using the volume calculation dialogue box.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Basic System
Looking first at FIG. 1, a scanning device 5 is shown as it scans the interior anatomical structure of a patient 10, as that patient 10 lies on a scanning platform 15.
Scanning device 5 is of the sort adapted to generate scanning data corresponding to a series of 2-D images, where each 2-D image corresponds to a specific viewing plane or "slice" taken through the patient's body. Furthermore, scanning device 5 is adapted so that the angle and spacing between adjacent image planes or slices can be very well defined, e.g., each image plane or slice may be set parallel to every other image plane or slice, and adjacent image planes or slices may be spaced a pre-determined distance apart. By way of example, the parallel image planes might be set 1 mm apart.
The scanning data obtained by scanning device 5 can be displayed as a 2-D slice image on a display 20, and/or it can be stored in its 2-D slice image data form in a first section 23 of a data storage device or medium 25. Furthermore, additional information associated with the scanning data (e.g., patient name, age, etc.) can be stored in a second section 27 of data storage device or medium 25.
By way of example, scanning device 5 might comprise a CT scanner of the sort manufactured by GE Medical Systems of Milwaukee, Wis.
By way of further example, a 2-D slice image of the sort generated by scanning device 5 and displayed on display 20 might comprise the 2-D slice image shown in FIG. 2. In the particular example shown in FIG. 2, the 2-D slice image shown corresponds to an axial slice taken through an individual's abdomen and showing, among other things, that individual's liver.
Scanning device 5 may format its scanning data in any one of a number of different data structures. By way of example, scanning device 5 might format its scanning data in the particular data format used by a CT scanner of the sort manufactured by GE Medical Systems of Milwaukee, Wis. More specifically, with such a scanning device, the scanning data is generally held as a series of data "frames", where each data frame corresponds to a particular 2-D slice image taken through the patient's body. Furthermore, within each data frame, the scanning data is generally organized so as to represent the scanned anatomical structure at a particular location within that 2-D slice image. Such a data structure is fairly common for scanning devices of the sort associated with the present invention. However, it should be appreciated that the present invention is not dependent on the particular data format utilized by scanning device 5. For the purposes of the present invention, the scanning data provided by scanning device 5 can be formatted in almost any desired data structure, so long as that data structure is well defined, whereby the scanning data can be retrieved and utilized as will hereinafter be disclosed in further detail.
For purposes of illustrating the present invention, it can be convenient to think of the scanning data generated by scanning device 5 as being organized in the data structures schematically illustrated in FIGS. 3 and 4.
More particularly, in FIG. 3, a series of data frames 30A, 30B, 30C, etc. are shown arranged in a parallel array. Each of these data frames 30A, 30B, 30C, etc. corresponds to a particular 2-D slice image taken through the patient's body by scanning device 5, where the 2-D slice images are taken parallel to one another. In addition, adjacent image planes or slices are spaced apart by a constant, pre-determined distance, e.g., 1 mm. It will be appreciated that data frames 30A, 30B, 30C, etc. collectively form a volumetric data set which is representative of the patient's scanned anatomical structure.
Furthermore, in FIG. 4, the scanning data contained within an exemplary data frame 30A is shown represented in an X-Y coordinate scheme so as to quickly and easily identify the scanned anatomical structure disposed at a particular location within that 2-D slice image. Typically, the scanning data relating to a particular X-Y coordinate represents an image intensity value. This image intensity value generally reflects some attribute of the specific anatomical structure being scanned, e.g., the tissue density.
As noted above, the scanning data generated by scanning device 5 is stored in its 2-D slice image data form in first section 23 of data storage device or medium 25, with the scanning data being stored in a particular data format as determined by the manufacturer of scanning device 5.
In accordance with the present invention, and looking now at FIG. 5, the scanning data stored in first section 23 of data storage device or medium 25 is retrieved, processed and then stored again in a data storage device or medium 30.
More particularly, the scanning data stored in first section 23 of data storage device or medium 25 is retrieved and processed so as to convert the scanning data generated by scanning device 5 from its 2-D slice image data form into a 3-D computer model of the patient's anatomical structure. This 3-D computer model is then stored in a first section 35 of data storage device or medium 30.
In addition, the scanning data stored in first section 23 of data storage device or medium 25 is retrieved and processed as necessary so as to convert the scanning data into a preferred data format for the 2-D slice image data. The 2-D slice image data is then stored in this preferred data format in second section 40 of data storage device or medium 30.
Furthermore, the additional information associated with the scanning data (e.g., patient name, age, etc.) which was previously stored in second section 27 of data storage device or medium 25 can be stored in a third section 42 of data storage device or medium 30.
In accordance with the present invention, once the 3-D computer model has been stored in first section 35 of data storage device or medium 30, and the 2-D slice image data has been stored in a preferred data format in second section 40 of data storage device or medium 30, a physician can then use an appropriately programmed computer to access the 3-D computer model stored in first section 35 of data storage device or medium 30, and/or the 2-D slice image data stored in second section 40 of data storage device or medium 30, to generate desired patient-specific images.
More particularly, and looking now at FIG. 6, once the 3-D computer model has been stored in first section 35 of data storage device or medium 30, and the 2-D slice image data has been stored in a preferred data format in second section 40 of data storage device or medium 30, a physician can use an appropriately programmed computer 50, operated by input devices 55, to access the 3-D computer model stored in first section 35 of data storage device or medium 30, and/or the 2-D slice image data stored in second section 40 of data storage device or medium 30, so as to generate the desired patient-specific images and display those images on a display 60.
To this end, it will be appreciated that the specific data structure used to store the 3-D computer model in first section 35 of data storage device or medium 30, and the specific data structure used to store the 2-D slice image data in second section 40 of data storage device or medium 30, will depend on the specific nature of computer 50 and on the particular operating system and application software being run on computer 50.
In general, however, the 3-D computer model contained in first section 35 of data storage device or medium 30 is preferably structured as a collection of software objects, with each software object being defined by a polygonal surface model of the sort well known in the art. By way of example, a scanned anatomical structure such as a human liver might be modeled as three distinct software objects, with the outer surface of the general mass of the liver being one software object, the outer surface of the vascular structure of the liver being a second software object, and the outer surface of a tumor located in the liver being a third software object. By way of further example, FIGS. 7 and 8 illustrate a typical manner of defining a software object by a polygonal surface model. In particular, FIG. 7 illustrates the vertices of a unit cube set in an X-Y-Z coordinate system, and FIG. 8 illustrates the data file format of the polygonal surface model for this simple unit cube. As is well known in the art, more complex shapes such as human anatomical structure can be expressed in corresponding terms.
Furthermore, the 3-D computer model contained in first section 35 of data storage device or medium 30 is created by analyzing the 2-D slice image data stored in first section 23 of data storage device or medium 25 using techniques well known in the art. For example, the 2-D slice image data stored in first section 23 of data storage device or medium 25 might be processed using the well known "Marching Cubes" algorithm, which is a so-called "brute force" surface construction algorithm that extracts isodensity surfaces from a volumetric data set, producing from one to five triangles within voxels that contain the surface. Alternatively, the 2-D slice image data stored in first section 23 of data storage device or medium 25 might be processed into the 3-D computer model stored in first section 35 of data storage device or medium 30 by some other appropriate modeling algorithm so as to yield the desired 3-D computer model which is stored in first section 35 of data storage device or medium 30.
As noted above, the specific data structure used to store the 2-D slice image data in second section 40 of data storage device or medium 30 will also depend on the specific nature of computer 50 and on the particular operating system and application software being run on computer 50.
In general, however, the 2-D slice image data contained in second section 40 of data storage device or medium 30 is preferably structured as a series of data "frames", where each data frame corresponds to a particular 2-D slice image taken through the patient's body, and where the scanning data within each data frame is organized so as to represent the scanned anatomical structure at a particular location within that 2-D slice image.
In the present invention, it is preferred that computer 50 comprise a Power PC-based, Macintosh operating system ("Mac OS") type of computer, e.g. a Power PC Macintosh 8100/80 of the sort manufactured by Apple Computer, Inc. of Cupertino, Calif. In addition, it is preferred that computer 50 be running Macintosh operating system software, e.g. Mac OS Ver. 7.5.1, such that computer 50 can readily access a 3-D computer model formatted in Apple's well-known QuickDraw 3-D data format and display images generated from that 3-D computer model, and such that computer 50 can readily access and display 2-D images formatted in Apple's well-known QuickTime image data format. Input devices 55 preferably comprise the usual computer input devices associated with a Power PC-based, Macintosh operating system computer, e.g., input devices 55 preferably comprise a keyboard, a mouse, etc.
In view of the foregoing, in the present invention it is also preferred that the 3-D computer model contained in first section 35 of data storage device or medium 30 be formatted in Apple's QuickDraw 3-D data format, whereby the Mac OS computer 50 can quickly and easily access the 3-D computer model contained in first section 35 of data storage device or medium 30 and display images generated from that 3-D computer model on display 60.
In view of the foregoing, in the present invention it is also preferred that the 2-D slice image data contained in second section 40 of data storage device or medium 30 be formatted in Apple's QuickTime image data format. In this way computer 50 can quickly and easily display the scanned 2-D slice images obtained by scanning device 5. It will be appreciated that, to the extent that scanning device 5 happens to format its scanning data in the preferred QuickTime image data format, no reformatting of the 2-D slice image data will be necessary prior to storing the 2-D slice image data in second section 40 of data storage device or medium 30. However, to the extent that scanning device 5 happens to format its scanning data in a different data structure, reformatting of the 2-D slice image data will be necessary so as to put it into the preferred QuickTime image data format. Such image data reformatting is of the sort well known in the art.
As a result of the foregoing, it will be seen that a physician operating computer 50 through input devices 55 can generate a desired image from the 3-D computer model contained within first section 35 of data storage device or medium 30. In particular, the physician can use input devices 55 to (1) open a window on display 60, (2) instruct the computer as to the desired angle of view, (3) generate the corresponding image of the scanned anatomical structure from the desired angle of view, using the 3-D computer model contained within first section 35 of data storage device or medium 30, and (4) display that image in the open window on display 60.
In addition, a physician operating computer 50 through input devices 55 can display a desired 2-D slice image from the 2-D slice image data contained within second section 40 of data storage device or medium 30. In particular, the physician can use input devices 55 to (1) open a window on display 60, (2) select a particular 2-D slice image contained within second section 40 of data storage device or medium 30, and (3) display that slice image in the open window on display 60.
More particularly, and looking now at FIGS. 9A-9F, computer 50 is preferably programmed so as to provide a variety of pre-determined menu choices which may be selected by the physician operating computer 50 via input devices 55.
Thus, for example, if the physician wishes to produce a desired image from the 3-D computer model contained within first section 35 of data storage device or medium 30, the physician uses input devices 55 to invoke the command to display the 3-D computer model; the software then creates a window to display the image, it renders an image from the 3-D computer model contained within first section 35 of data storage device or medium 30, and then displays that image in the open window on display 60. By way of example, FIG. 10 illustrates an image drawn to a window using the data contained in the 3-D computer model stored in first section 35 of data storage device or medium 30. The physician can use input devices 55 to instruct the image rendering software as to the specific angle of view desired. In particular, computer 50 is preferably programmed so that the physician can depress a mouse key and then drag on the object so as to rotate the object into the desired angle of view. Additionally, computer 50 is preferably programmed so that the physician can also use the keyboard and mouse to move the view closer in or further out, or to translate the object side to side or up and down relative to the image plane. Programming to effect such computer operation is of the sort well known in the art.
In a similar manner, the physician can use menu choices such as those shown in FIGS. 9A-9F to open a window on the display 60 and then to display in that window a desired 2-D slice image from second section 40 of data storage device or medium 30. Computer 50 is programmed so that the physician can select between different slice images by means of input devices 55. By way of example, FIG. 11 illustrates a 2-D slice image drawn to a window by the operating system using the data contained in second section 40 of data storage device or medium 30. In this case, computer 50 is programmed so that, by dragging icon 70 back and forth along slider 75, the physician can "leaf" back and forth through the collection of axial slices, i.e., in the example of FIG. 11, in which axial slice #21 is displayed, dragging icon 70 to the left might cause axial slice #20 to be displayed, and dragging icon 70 to the right might cause axial slice #22 to be displayed. Additionally, computer 50 is preferably programmed so that the physician can also step the image from the current slice number to a previous or following slice number by using menu commands or by clicking the mouse cursor on the single step icons 76 set at the right side of slider 75. Computer 50 is preferably also programmed so that menu commands are provided to change the slice window display directly to the first or last slice image in the 2-D slice image set, or to change the slice window display to a user-specified slice number. Programming to effect such computer operation is of the sort well known in the art.
As a consequence of using the aforementioned hardware and software architecture (i.e., the Macintosh computer, the Mac OS, the Apple QuickDraw 3D data format and software, and the Apple QuickTime image data format and software, or some equivalent hardware and software), it is possible to insert an additional software object into the 3-D computer model contained within first section 35 of data storage device or medium 30. In particular, it is possible to insert an additional software object having a "blank" planar surface into the 3-D computer model. Furthermore, using the computer's image rendering software, it is possible to texture map a 2-D slice image from second section 40 of data storage device or medium 30 onto the blank planar surface of the inserted software object. Most significantly, since the 3-D computer model is created out of the same scanning data as the 2-D slice images, it is possible to determine the specific 2-D slice image which corresponds to a given position of the blank planar surface within the 3-D computer model. Accordingly, with the present invention, when an image is generated from the 3-D computer model, both 3-D model structure and 2-D slice image structure can be simultaneously displayed in proper registration with one another, thereby providing a single composite image of the two separate images. See, for example, FIG. 12, which shows such a composite image. Again, computer 50 is programmed so that the physician can use input devices 55 to instruct the operating system's image rendering software as to where the aforementioned "additional" software object is to be inserted into the model and as to the particular angle of view desired. Programming to effect such computer operation is of the sort well known in the art.
Additionally, computer 50 is also programmed so that (1) the physician can use input devices 55 to select a particular 2-D slice image from the second section 40 of data storage device or medium 30, and (2) the computer will then automatically insert the aforementioned additional software object into the 3-D computer model so that the object's "blank" planar surface is located at the position which corresponds to the position of the selected 2-D slice image relative to the scanned anatomical structure. Again, programming to effect such computer operation is of the sort well known in the art.
In the foregoing description of the present invention, the 2-D slice image data generated by scanning device 5 has generally been discussed in the context of the standard "axial" slice images normally generated by scanning devices of the type associated with this invention. However, it is to be appreciated that the present invention is also adapted to utilize sagittal and/or coronal 2-D slice images. Furthermore, it is also to be appreciated that the present invention is adapted to utilize oblique slice images of the type hereinafter described.
More particularly, and looking next at FIG. 13, the relative orientation of axial, sagittal and coronal slice images are shown in the context of a schematic view of a human body 80. Scanning device 5 will normally generate axial slice image data when scanning a patent. In addition, in many cases scanning device 5 will also assemble the axial slice data into a 3-D database (i.e., a volumetric data set) of the scanned anatomical structure, and then use this 3-D database to generate a corresponding set of sagittal and/or coronal 2-D slice images. In the event that scanning device 5 does not have the capability of generating the aforementioned sagittal and/or coronal 2-D slice images, such sagittal and/or coronal 2-D slice images may be generated from a set of the axial 2-D images in a subsequent operation, using computer hardware and software of the sort well known in the art. Alternatively, if desired, computer 50 may be programmed to render such sagittal and/or coronal 2-D slices "on the fly" from the 2-D slice image data contained in second section 40 of data storage device or medium 30.
In connection with the present invention, the sagittal and coronal 2-D slice image data may be stored with the axial slice image data in second section 40 of data storage device or medium 30. Preferably these sagittal and coronal slice images are stored in exactly the same data format as the 2-D axial slice images, whereby they may be easily accessed by computer 50 and displayed on display 60 in the same manner as has been previously discussed in connection with axial 2-D slice images. As a result, axial, sagittal and coronal 2-D slice images can be displayed on display 60, either individually or simultaneously in separate windows, in the manner shown in FIG. 14. Furthermore, when generating a composite image of the sort shown in FIG. 12 (i.e., an image generated from both the 3-D computer model contained in first section 35 of data storage device or medium 30 and a 2-D slice image contained in second section 40 of data storage device or medium 30), the composite image can be created using axial, sagittal or coronal 2-D slice images, as preferred.
It is also to be appreciated that the system of the present invention is also configured so as to generate and utilize oblique 2-D slice image data in place of the axial, sagittal and coronal slice image data described above. More particularly, computer 50 is programmed so that a physician can use input devices 55 to specify the location of the oblique 2-D slice image desired, and then computer 50 generates that 2-D slice image from the volumetric data set present in second section 40 of data storage device or medium 30 (i.e., from the collection of 2-D slice images contained in second section 40 of data storage device or medium 30).
It should be appreciated that data storage device or medium 30 can comprise conventional storage media (e.g., a hard disk, a CD ROM, a tape cartridge, etc.), which can be located either on-site or at a remote location linked via appropriate data transfer means.
Markers And Margins
In a further aspect of the present invention, computer 50 is programmed so that a physician can display a specific 2-D slice image in a window opened on display 60, place a marker into that specific 2-D slice image using a mouse or other input device 55, and then have that marker automatically incorporated into both (i) the 3-D computer model contained in first section 35 of data storage device or medium 30, and (ii) any appropriate 2-D slice image data contained in second section 40 of data storage device or medium 30. As a result, when images are thereafter generated from the 3-D computer model contained in first section 35 of data storage device or medium 30, and/or from the 2-D slice image data contained in second section 40 of data storage device or medium 30, these subsequent images will automatically display the marker where appropriate. See, for example, FIG. 14, which shows one such marker 85 displayed in its appropriate location in each of the three displayed 2-D slice images, i.e., in axial slice image 90, sagittal slice image 95, and coronal slice image 100. It is to be appreciated that it is also possible for marker 85 to be displayed where appropriate in an image generated from the 3-D computer model contained in first section 35 of data storage device or medium 30; see, for example, FIG. 15, which shows such a marker 85 being displayed in the image.
In yet another aspect of the present invention, computer 50 is programmed so that a physician can generate a "margin" of some predetermined size around such a marker. Thus, for example, in FIG. 15, a margin 105 has been placed around marker 85. In this respect it is to be appreciated that margin 105 will appear as a 3-dimensional spherical shape around marker 85, just as marker 85 appears as a 3-dimensional shape, since the view of FIG. 15 is generated from the 3-D computer model contained in first section 35 of data storage device or medium 30. Alternatively, where marker 85 and margin 105 are displayed in the context of 2-D slice images, the marker and margin will appear as simple circles. Margin 105 can be used by a physician to determine certain spatial relationships in the context of the anatomical structure being displayed on the computer.
Peripheral Highlighting
It is also to be appreciated that, inasmuch as the 3-D computer model contained in first section 35 of data storage device or medium 30 constitutes a plurality of software objects defined by polygonal surface models, it is possible to identify the periphery of any such objects in any corresponding 2-D slice image data contained in second section 40 of data storage device or medium 30. As a result, it is possible to highlight the periphery of any such object in any 2-D slice images displayed on display 60. Thus, in another aspect of the invention, computer 50 is programmed so that a physician can select one or more anatomical structures using an input device 55, and the computer will then highlight the periphery of that structure in any corresponding 2-D slice images displayed on display 60. See, for example, FIG. 16, where a boundary 110 is shown outlining the periphery of an object 115 displayed in a 2-D slice image.
Other Modifications Of The Basic System
Furthermore, while in the foregoing description the present invention has been described in the context of an anatomical visualization system being used by a physician, it is also to be appreciated that the system could be used in conjunction with inanimate objects being viewed by a non-physician, e.g., the system could be used to visualize substantially any object for which a 3-D computer model and a collection of 2-D slice image data can be assembled.
It is also anticipated that one might replace the polygonal surface model discussed above with some other type of surface model. Thus, as used herein, the term "surface model" is intended to include polygonal surface models, parametric surface models such as B-spline surface models, quadralateral meshes, etc.
Centerline Calculations
In yet another form of the present invention, the visualization and measurement system may incorporate means for determining patient-specific anatomical dimensions using appropriate scanned 2-D image data.
For purposes of illustration but not limitation, this aspect of the present invention will be discussed in the context of measuring a patient's vascular structure in the region of the aortic/iliac branching. By way of further example, such measurement might be conducted in the course of repairing an aortic aneurysm through installation of a vascular prosthesis.
More particularly, using the aforementioned scanning device 5, a set of 2-D slice images is first generated, where each 2-D slice image corresponds to a specific viewing plane or "slice" taken through the patient's body. As noted above, on these 2-D slice images, different types of tissue are typically represented by different image intensities. By way of example, FIG. 17 illustrates a 2-D slice image 200 taken through the abdomen of a patient, at a location above the aortic/iliac branching; FIG. 18 illustrates a 2-D slice image 202 taken through the abdomen of the same patient, at a location below the aortic/iliac branching. In these images, vascular tissue might be shown at 205, bone at 207, other tissue at 210, etc. An appropriate set of these 2-D slice images is assembled into a 3-D database so as to provide a volumetric data set corresponding to the anatomical structure of the patient. Referring back to the system illustrated in FIG. 6, the set of 2-D slice images making up this 3-D database might be stored in second section 40 of data storage device or medium 30. In this respect it is also to be appreciated that the 3-D database being referred to now is not the same as the 3-D computer model contained in first section 35 of data storage device or medium 30; rather, the 3-D database being referred to now is simply a volumetric data set made up of the series of 2-D slice images contained in second section 40 of data storage device or medium 30.
Next, using the appropriately programmed computer 50, the patient-specific volumetric data set (formed out of the collection of 2-D slice images contained in the 3-D database) is segmented so as to highlight the anatomical structure of interest.
This is preferably effected as follows. On the computer's display 60, the user is presented with 2-D slice images from the 3-D database, which images are preferably stored in second section 40 of data storage device or medium 30. As noted above, each of these 2-D images corresponds to a specific viewing plane or "slice" taken through the patient's body; or, stated slightly differently, each of these 2-D images essentially represents a plane cutting through the patient-specific volumetric data set contained in the 3-D database. As also discussed above, with each of these 2-D slice images, the different types of tissue will generally be represented by different image intensities. Using one or more of the input devices 55, e.g., a mouse, the user (who might or might not be a physician) selects a particular 2-D slice image for viewing on display 60, e.g., "slice image #155". The user then uses one or more of the input devices 55 to select one or more points located within the anatomical structure of interest. For convenience, such user-selected points can be referred to as "seeds". See, for example, FIG. 17, where a seed point 215 has been selected within the interior of vascular tissue 205 so as to identify blood. The user also uses one or more of the input devices 55 to specify a range of image intensities that appear to correspond to the anatomical structure of interest in the volumetric data set, e.g., blood within the interior of a blood vessel.
In accordance with the present invention, the appropriately programmed computer 50 then applies a segmentation algorithm of the sort well known in the art to segment out related structure within the patient-specific 3-D database. Preferably computer 50 is programmed to apply a 3-D connected component search through the volumetric data set contained in second section 40 of data storage device or medium 30 so as to determine the set of volumetric samples that are (i) within the range specified for blood, and which (ii) can be connected along a connected path back to one of the seeds, where each of the locations along the path is also within the range specified for blood. The result of this 3-D connected component search is a set of 3-D locations in the volumetric data set which correspond to blood flowing through the blood vessel. For the purposes of the present illustration, this set of 3-D locations can be characterized as the "blood region". The segmented anatomical structure (i.e., the blood in the blood region) can then be highlighted or otherwise identified on each of the 2-D slice images. See, for example, FIGS. 17A and 18A, where the segmented blood region in vascular tissue 205 has been cross-hatched to represent such highlighting.
Next, the branches in the segmented anatomical structure are identified. For example, and looking now at FIG. 19, in the present illustration dealing with vascular structure in the region of the aortic/iliac branching, the aorta and the two iliac branches would be separately identified.
This is done in the following manner. For each of the vessel segments that are part of the branching structure of interest, the user specifies a branch line in the volumetric data set that uniquely indicates that vessel segment. This is accomplished by using one or more of the input devices 55 to select, for each branch line, an appropriate "start" location on one of the 2-D slice images contained within second section 40 of data storage device or medium 30, and an appropriate "end" location on another one of the 2-D slice images contained within second section 40 of data storage device or medium 30. It should be appreciated that these branch lines do not need to cover the entire length of interest of the vessel and, in practice, will tend to stop somewhat short of the junction where various branches converge with one another. At the same time, however, for improved accuracy of modeling the branching structure, the branch lines should extend close to the bifurcation point.
For each of the vessel branches, the start and end locations are used to subdivide the blood region as follows: the region for that vessel branch is the set of locations within the blood region that are between the start plane and the end plane, where the start plane for each vessel branch is the 2-D image plane passing through the start location for the corresponding branch line, and the end plane for each vessel branch is the 2-D image plane passing through the end location for each vessel branch.
Although the invention could be used for a more complex branching structure through obvious extensions, it is useful to consider a vessel branch structure consisting of just three vessel segments coming together at a branch point, e.g., a vessel branch structure such as the aortic/iliac branching shown in FIG. 19. In this case, the user would designate one vessel region as the root region (e.g., the aortic region 220 defined by a branch line 225 having a start location 230 contained in a start plane 235, and an end location 240 contained in an end plane 245) and the other vessel regions as branch region A (e.g., the iliac region 250 defined by a branch line 255 having a start location 260 contained in a start plane 265, and an end location 270 contained in an end plane 275), and branch region B (e.g., the iliac region 280 defined by a branch line 285 having a start location 290 contained in a start plane 295, and an end location 300 contained in an end plane 305), respectively.
For each of the vessel regions determined in the previous step, a centroid path is then calculated. This is accomplished in the following manner. First, at intervals along the vessel line corresponding to the volumetric location of each of the original 2-D slice images contained in second section 40 of data storage device or medium 30, the centroid of the vessel region in that particular 2-D slice image is calculated. This is done by averaging the image coordinates of all locations in that 2-D slice image that are within the vessel region so as to yield a centroid point. See, for example, FIG. 20, which schematically illustrates the manner of calculating the centroid 310 for a representative vessel region 312 in a representative 2-D slice image 315.
The centroid path for each vessel region is then established by the collective set of centroid points located along that vessel segment in three-dimensional space. The tortuous path corresponding to the root region is called the root centroid path and the tortuous paths corresponding to branch regions A and B are called branch centroid path A and branch centroid path B, respectively. See, for example, FIG. 21, which shows a plurality of centroids 320, a root centroid path generally indicated at 325, a branch centroid path A generally indicated at 330, and a branch centroid path B generally indicated at 335, all shown in the context of a vessel branch structure such as the aortic/iliac branching example discussed above. It is to be appreciated that no centroids will be defined in the "unknown" region 336 bounded by the end plane 245 and the start plane 265, and the "unknown" region 337 bounded by the end plane 245 and the start plane 295.
The system is programmed so that it will then apply a curve-fitting algorithm to the tortuous centroid paths determined above so as to supply estimated data for any portions of the anatomical structure which may lie between the aforementioned branch lines, and for "smoothing out" any noise that may occur in the system.
This is preferably done through a spline fitting algorithm effected in the following manner. First, two new paths are created, by concatenating the points in the root centroid path 325 with the points in each of the two branch centroid paths 330 and 335, so as to create a path root-A and a path root-B. These two new paths are then used as the input to a spline fitting routine which selects the coefficients for a piecewise polynomial space curve that best approximates the points along the path in a least-squares sense. The number of pieces of the approximation and the order of polynomial may be varied by the user. The resulting curves may be called spline-root-A and spline-root-B. See, for example, FIG. 22, which illustrates the spline-root-B, generally indicated at 340.
Through numerical integration, the distance along the two splines (i.e., spline-root-A and spline-root-B) can then be calculated using standard, well-known techniques, and the result can be presented to the user. These calculations can be used for a variety of purposes, e.g., to help determine the appropriate size of a vascular prosthesis to be used in repairing an aneurysm at the aortic/iliac junction.
In addition, using well established mathematical techniques, at any point along the spline paths, a tangent vector and a perpendicular plane can be readily determined either by direct calculation or by definition in those cases where direct calculation would be undefined. By calculating the distance from the spline path to the points in the volumetric data set corresponding to the vessel branch region that are within an epsilon distance of the perpendicular plane, the shape of the vessel at that point can be determined, and the radius of a circle that best fits the cross-sectional area of the vessel at that point can also be readily calculated. Again, this result can be used to help determine that desired graft shape.
FIG. 23 is a flow chart illustrating how patient-specific anatomical dimensions can be determined from scanned 2-D data in accordance with the present invention.
In addition to the foregoing, it is possible to use the centerline derived above to generate additional views for the observer, and/or to make further anatomical calculations and measurements.
Oblique Slices Derived From The Centerline
Among other things, it is possible to use the centerline derived above to construct a series of oblique slices through the volumetric data set (which volumetric data set is formed out of the assembled scanned 2-D slice images contained in second section 40 of data storage device or medium 30) such that the reconstructed oblique slices are disposed perpendicular to the centerline.
More particularly, oblique slices per se are generally well known in the art, to the extent that such oblique slices are arbitrary planar resamplings of the volumetric data set. However, the utility of these arbitrary oblique slices is limited for many applications, since there is no explicit, well-defined relationship between their position and anatomical structures of interest. By way of example, in the case of blood vessels, oblique slices taken perpendicular to the length of the blood vessel are of particular importance to the physician. However, when generating oblique slices using traditional techniques (e.g., by pointing with an input device 55 while viewing the display 60), it is very difficult for the physician to specify the oblique slice which is truly perpendicular to the blood vessel at a specified point. This problem is avoided with the present invention, which utilizes the centerline as derived above to generate the set of oblique slices lying perpendicular to the blood vessel. This set of oblique slices derived from the centerline is preferably stored in a fourth section 400 of data storage device or medium 30 (FIGS. 5 and 6).
In general, one way to think about generating any oblique slice is to consider a four-sided polygon that is placed in the space defined by the volumetric data set. This polygon is then scan converted to resample the axial images so as to generate the oblique slice desired. As used herein, the term "scan converted" is intended to refer to the well-known techniques of subdividing a polygon into regularly spaced intervals on a rectangular grid.
In the present invention a programmable computer is used to generate the specific set of oblique slices that is defined by the centerline derived above. This is accomplished as follows. First, the centerline is divided into n increments. This can be done with points P 0 , P 1 , . . . , P n , as shown in FIG. 24. A line T i is then derived for each of the points P i , where T i is the tangent line at that point P i . Finally a series of oblique slices are produced by constructing a series of four-sided polygons, each of which is centered at P i and normal to T i . The locations of the corners of the polygon are selected such that the resulting image orientation is as close as possible to a pre-selected image orientation (e.g., axial). These four-sided polygons are then scan converted as described above so as to provide the set of oblique slice images lying perpendicular to the centerline. As noted above, this set of oblique slice images is stored in fourth section 400 of data storage device or medium 30. At the same time, the corner locations of each four-sided polygon associated with each oblique slice image is also stored in fourth section 400 of data storage device or medium 30, whereby the precise location of each oblique slice image within the volumetric data set is established.
As a result of the foregoing, the oblique slice images stored in fourth section 400 of data storage device or medium 30 is available to be accessed by computer 50 in exactly the same manner as the 2-D axial slice images stored in second section 40 of data storage device or medium 30.
Furthermore, once the aforementioned oblique slices have been derived from the centerline, these oblique slices can then be used for a variety of additional purposes.
Measuring Diameters Along The Centerline
As noted above, the oblique slice images derived from the centerline can be accessed by computer 50 from fourth section 400 of data storage device or medium 30. The physician can then use input devices 55 to instruct computer 50 to access the oblique slice at a particular location along the blood vessel and measure the diameter of the same. In particular, the physician can use input devices 55 to access the particular oblique slice desired and then lay down two diametrically-opposed marks so as to define the diameter of the blood vessel; the computer is adapted in ways well known in the art to then calculate the distance between the two marks. In this respect it should be appreciated that since the aforementioned oblique slice images are, by definition, taken perpendicular to the blood vessel at each point along the blood vessel, the blood vessel diameters so measured will tend be much more accurate than diameters calculated solely off axial slice images, and/or off coronal and/or sagittal and/or "standard", non-centerline-derived oblique slice images.
Measuring Distances With A Cumulative Sum Table
It has also been found that it can be advantageous to store the incremental distances between the centerline points P 1 , P 2 , . . . , P n in a cumulative sum table in which the first entry, C 0 , is 0; the second entry, C 1 , is the distance between P 1 and P 0 (i.e., C 1 =P 1 -P 0 ); the third entry C 2 =C 1 +(P 2 -P 1 ); etc. Thus, the centerline distance between any two points P i and P j is simply D ij =C i -C j .
In the present invention, the cumulative sum table can be of the sort shown in FIG. 25. This cumulative sum table is preferably stored in a fifth section 405 of data storage device or medium 30. Computer 50 is also programmed so that the user interface presents a centerline length calculation dialogue box 407 (FIG. 26) to the physician on display 60, by which the physician can specify (using input devices 55) two oblique slice images which are the end points of the length which is to be determined. Computer 50 is programmed so that it will then determine the length between the two chosen oblique slices by calculating the difference in their positions from the cumulative sum table.
Computer 50 is also programmed so that a 3-D graphical icon 408 (FIG. 27) is inserted into the 3-D model contained in first section 35 of data storage device or medium 30. This icon represents the portion of the vessel centerline which has been specified by the physician via the two oblique slice images which represent the length end points.
Calculating Volumes Using A Cumulative Sum Table
A cumulative sum table can also be used to calculate volumes with respect to an anatomical structure, in much the same way that a cumulative sum table can be used to calculate lengths along an anatomical structure. However, incremental slice volumes are more appropriately calculated in the axial direction rather than in the oblique slice direction. This is because the axial slices all lie parallel to one another, whereas the oblique slices (since they are generated from the centerline) do not.
To this end, a computer is used to calculate the volume of each axial slice, V i , by (1) determining the number of pixels in the segmented region of that axial slice, (2) scaling by the appropriate pixel-to-length factor, and then (3) multiplying by the slice thickness. A cumulative sum table is then generated, where the first entry, C 0 , is V 0 ; the second entry, C 1 =C 0 +V 1 ; the third entry C 2 =C 1 +V 2 ; etc. In the present invention, this cumulative sum table can be of the sort shown in FIG. 28. This cumulative sum table is stored in sixth section 410 of data storage device or medium 30. Computer 50 is also programmed so that the user interface presents a volume calculation dialogue box 412 (FIG. 29) to the physician on display 60 that allows the physician to conveniently specify two axial slices as the end points of the volume to be determined. Computer 50 then calculates the volume for the region specified, using the cumulative sum table. Computer 50 is also programmed so as to place a 3-D graphical icon 415 (FIG. 30) in the 3-D model contained in the first section 35 of data storage device or medium 30. This icon represents the volume specified by the physician using the volume calculation dialogue box.
Further Modifications
It is also to be understood that the present invention is by no means limited to the particular construction herein disclosed and/or shown in the drawings, but also comprises any modifications or equivalents within the scope of the claims.
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The present invention provides an anatomical visualization and measurement system including a first database of 2-D slice images and a second database including a 3-D computer model defining a first software object. Apparatus is provided for selecting a 2-D slice image from the first database. Apparatus is also provided for inserting a second software object into the 3-D computer model. The second software object includes a planar surface and is inserted into the 3-D computer model at the position which corresponds to the position of the selected 2-D slice image relative to the scanned structure. Apparatus is also provided for texture mapping the 2-D slice image onto the planar surface. Display apparatus is provided for displaying an image which simultaneously provides a view of the first software object and the 2-D slice image texture mapped onto the planar surface. An apparatus and method are also provided for determining structural dimensions and volumes using appropriate scanned 2-D slice image information. The present invention permits an appropriate set of scanned 2-D images to be assembled into a 3-D database, information regarding selected structural features to be segmented out of the 3-D database, and measurements to be made based on these structural features. In addition, the present invention permits a set of oblique images to be generated based on these structural features, which oblique images may themselves be used for measurement purposes.
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BACKGROUND OF THE INVENTION
Reference is made to my previous U.S. Pat. No. 4,453,611 issued June 12, 1984; and to the art cited therein, for further background of this invention. The present invention provides improvements over the above prior art by the provision of a low profile track assembly which supports a main body by a cantilever suspension arm. One end of the suspension arm is sprung to the rear end of the track assembly, while the other end of the suspension arm is attached to the main body. Power is supplied to the track assembly by a drive train which extends through the suspension arm and to a motor located within the main body. The main body provides a saddle for accommodating one or a plurality of riders. A handle bar support system is pivoted to the main body.
The track flexes laterally into a curve in a manner whereby the center of gravity is maintained at an optimum location so that the rider is positioned over the flotation centerline of the current track, which adds stability while the vehicle is negotiating turns.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of a vehicle made in accordance with the present invention;
FIG. 2 is a top plan view of the vehicle disclosed in FIG. 1;
FIG. 3 is a front view of the vehicle seen disclosed in the foregoing figures;
FIG. 4 is a rear view of the vehicle disclosed in the foregoing figures;
FIG. 5 is a bottom view of the vehicle disclosed in the foregoing figures; with the single track flexed laterally so that the vehicle being illustrated is in a configuration for negotiating a turn;
FIG. 6 is a side elevational view, similar to FIG. 1, with the apparatus being shown in an alternate position;
FIG. 7 is an enlarged, longitudinal, part cross-sectional view of the vehicle disclosed in the foregoing figures;
FIG. 8 is a part diagrammatical, part schematical, plan view of part of the apparatus disclosed in the foregoing figures with the track linkage being flexed laterally; and
FIG. 9 is a lateral cross-sectional view of the track assembly seen in FIG. 7.
SUMMARY OF THE INVENTION
A snowmobile type vehicle having a track assembly which includes a narrow, single, oblated, laterally flexible, endless track centrally located and guided about a track guide means. The track assembly supports and propels the vehicle along the surface of the snow. The vehicle of this invention includes a main body having a seat or saddle formed thereon for accommodating one or more riders. The main body is sprung from the track assembly by a spring loaded cantilever arm having spring means at the distal ends thereof. The spring means permits the main body to be resistingly urged toward and away from the track assembly while remaining substantially parallel to the track assembly.
A motor is supported within the main body and is connected to the track assembly by a drive train which extends through the interior of the suspension arm. The main body further includes a steering system in the form of a handle bar connected through the suspension arm and to the track assembly in a manner whereby the endless track of the track assembly is laterally flexed into a curve, whereby the center of gravity of the main body stays above the flotation centerline of the endless track when it is desired to turn the vehicle and change the direction of travel.
The track assembly is a low profile mechanism having a track tunnel formed therethrough, with the tunnel being formed through a plurality of individual, series connected, adjacent segments pivotally attached to one another in a manner to provide for the aforementioned lateral flexing. The endless track is captured respective to the segments and therefore must assume the same radius of curvature presented by the segments.
A primary object of the present invention is the provision of a single track vehicle having a main body assembly separated from and supported above a track assembly by a suspension arm.
Another object of the present invention is the provision of a single track vehicle having a power system and steering control system connected from a main body, through a suspension arm, and to the track means.
A further object of the present invention is the provision of a single track vehicle having a segmented track assembly which is bendable laterally by means of a special push pull linkage so that the impact of the vehicle respective to the terrain is not substantially transmitted into the steering mechanism.
A still further object of the present invention is the provision of a single track vehicle having a main body assembly arranged whereby a special linkage changes the track from a longitudinal into a curved configuration in a manner to keep the center of gravity of the vehicle centered over the flotation centerline of the track.
Another and still further object of the present invention is the provision of a single track vehicle having a main body suspended from a track means by a suspension arm, with the suspension arm being connected to the track means by a spring means which maintains the main body in a substantially level attitude while traversing rough terrain.
These and various other objects and advantages of the invention will become readily apparent to those skilled in the art upon reading the following detailed description and claims and by referring to the accompanying drawings.
The above objects are attained in accordance with the present invention by the provision of a combination of elements which are fabricated in a manner substantially as described in the above abstract and summary.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIG. 1, together with other figures of the drawings, there is disclosed a single track vehicle 10 made in accordance with the present invention. The vehicle has a main body assembly 12 supported from a track assembly 14. The main body assembly 12 is in the form of a pod-like enclosure 16 within which there is housed various mechanisms, as will be more fully described hereinafter.
As seen illustrated in FIG. 5, the track assembly 14 is laterally flexible so that the track curves in a horizontal plane, as seen illustrated at 15, from a straight or longitudinal line, as seen illustrated at 17.
Looking again now to FIG. 1, in conjunction with FIGS. 2-8, the main body assembly includes a steering apparatus operated by handle bars 18. A gas tank 19, more particularly shown in FIG. 7, is provided forwardly of a saddle or seat 20. The seat may accommodate several riders.
A foot pan 25 formed as an integral part of main body assembly 12 provides a foot support surface for riders. The enclosing lower section 27 of enclosure 16 is shown in FIGS. 1 and 6. A motor compartment 26 is formed at the rear end of enclosure 16 thereof.
Main body assembly 12 is sprung from track assembly 14 by means of a suspension arm assembly 28, constructed in accordance with the present invention. Main body assembly 12 is attached to one of the opposed ends 49 of suspension arm 28, while the other end of suspension arm 28 is attached at 30 to the rear marginal end of track assembly 14.
Numeral 33 indicates the front of track assembly 14 while numeral 34 indicates the forwardmost end of the vehicle, and numeral 38 generally illustrates the upper surface of the forward marginal end of track assembly 14.
Track assembly 14 comprises a plurality of the illustrated track segments 40 attached to one another in a manner which will be more fully disclosed hereinafter. Track segments 40 jointly cooperate together in a manner to accommodate an endless belt or track 41 which is captured in supported relationship thereabout.
As best seen illustrated in FIG. 7, the endless belt 41 is suitably connected to be driven by a motor 42. Motor 42 has an output pulley 44 connected to a drive belt idler pulley 45. Shaft 46 rotatably supports the idler pulley 45 as well as provides a pivot by which the main body 16 is pivotally attached to one end 49 of the before mentioned suspension arm 28.
Suspension arm 28 is of hollow construction and includes an extension plate 47 formed thereon which receives a spring assembly 48 thereagainst. The opposed side of the spring assembly bears against the interior of enclosure 16 at the upper end 49 of suspension arm 28 which can be reinforced if desirable. Spring assembly 48 can be a pneumatic body, a rubber member, or a metallic spring arrangement. Accordingly, body assembly 12 can be pivoted in a vertical plane about the shaft 46 while spring assembly 48 urges the body assembly into the illustrated neutral position of FIG. 7.
An endless drive belt or chain 50 is enclosed within suspension arm 28 and is drivingly connected to transmit power between pulleys 45 and 51. Pulley 51 is secured in journaled relationship to track assembly 14 by means of shaft 52. Shaft 52 permits the lower end of suspension arm 28 to be pivoted about shaft 52 respective to track assembly 14.
Suspension arm 28 is attached at 30 to the rear marginal end of track assembly 14 which provides an outer curved wall 54 as shown in FIG. 7. Outer curved wall 54 is concentric and spaced from inner curved wall 56 of track assembly 14. Inner curved wall 56 terminates in a rearwardly directed plate 57 which strengthens the rear part of track assembly 14 and makes it more rigid.
The handle bars 18 are connected to a step-up rotary ratio assembly 58, which rotates a rotary cable assembly 59. A medial length 59' of the rotary cable assembly is housed within the suspension arm 28. It may be understood by those skilled in the art that conventional hydraulic or mechanical steering linkages may be used in place of the steering assembly shown.
A load transfer member 60 is rigidly affixed to the curved housing 56 and is spaced from a complementary contoured guide member 62. The contoured guide member 62, curved member 56, and member 60 jointly cooperate together to provide part of a track tunnel 63 having an entrance 64 and exit 65 for the before mentioned endless track.
Track spring assembly 66 is captured between walls 67, 68, and 69. Numeral 70 illustrates a spring assembly chamber within which the before mentioned spring 66 is captured and stores energy whenever the supsension arm is pivoted about shaft 52 respective to the track assembly. The suspension arm includes a curved end wall 71, of which members 30 and 54 are a continuation, and which is slightly spaced from the before mentioned curved wall 69.
The individual track segments 40 are articulated and thereby move respective to one another by means of pivot pins 72, 72' which are aligned along a common vertical axis for pivoting the forward most section 33 of the track assembly. A plurality of centrally located segments are similarly pivotally connected together by pivot pins 74, 74'; while the rear segment 60 is pinned to the central segments by means of a set of rear pins 76, 76'.
As seen illustrated in the figures of the drawings, and in particular FIGS. 5 and 8, the track segments are moved laterally respective to one another and into the before mentioned curved 15, 17, as seen in FIG. 5, for example. This curved configuration is achieved by a plurality of diagonal linkages pinned to move alternate track segments, with there being a forwardmost linkage 78, intermediate linkage 79, and a rear linkage 80. The rear linkage 80 is pinned to the rear segment 36 and to the subadjacent segment 40' by means of pins 81 and 82. The intermediate links 79 are pinned to alternate segments 40 by means of pins 83 and 84, while the forwardmost linkage 78 is pinned to the forwardmost segment and subadjacent segment by means of pins 85 and 86.
Sockets 88 and 90, respectively, are pivotally attached to the segments 40 and 36, and threaded to receive a threaded member 92 therethrough. The threaded member is provided with left and right hand threads, with a medial part of the illustrated screw being received through a steering bar 94. The threaded member 92 is attached at 87 to the before mentioned rotary cable assembly 59.
In operation, the motor 42 drives sproket 51 by means of the before mentioned drive train comprised of pulleys 44, 45, and 51. This action causes the track 41 to move along its length and thereby move into the entrance 64, through tunnel 63, and back through the exit 65, while supporting the vehicle from the immediate terrain. The vehicle main body assembly 16 is sprung at 48 and 66 so that the body, suspension arm, and track assembly are pivotally connected by pivot connections 46 and 52. Accordingly, as energy is stored and retrieved from springs 48 and 66, the vehicle body maintains proper alignment with respect to the track assembly as it moves towards and away therefrom.
When the handle bar 18 is turned, the gear box 58 rotates threaded member 92 which pivots members 36 and 40 towards and away from one another. Linkages 80, 79 and 78 cause each adjacent segment to be similarly pivoted about the respective pivot pins thereof. This cooperative action changes the configuration of the track from a linear to a curved configuration, as seen illustrated in FIG. 5 of the drawings.
The detailed illustration of FIG. 9 is a cross-sectional representation of track assembly 14. The endless belt 41 is housed within the plurality of segments 40 which form the main housing 55. The housing 55 includes the before mentioned outwardly directed platform 36 formed on opposed sides of the track assembly. The segments of the main housing form the before mentioned tunnel 63 through which the endless track is movably received. The track segments 41 are connected to one another by the illustrated cable 95 which forms the track segments 41 into an endless track assembly.
The main housing 55 includes the illustrated inwardly directed guide extensions 91 at the lower end of the housing, and similar guide extensions 92 at the upper end of the housing. The lower and upper guide extensions 91 and 92 are received within a complementary groove 93 of the endless track assembly 41. The segments 40 of the main housing 55 therefore form a continuous tunnel within which the endless track assembly is received. Upon emerging from tunnel exit 65 track segments 41 engage the ground surface and support the vehicle.
Attention is directed to my previous U.S. Pat. No. 4,453,611 entitled "Terrain Vehicle Having A Single, Laterally Bendable Track" for further background of a single track assembly for a vehicle.
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A vehicle especially adapted for traveling on snow, which has a single endless track made bendable laterally in order to change direction of travel. The vehicle has a main body assembly which is separated and supported above the track by a special suspension arm. A motor is located in the body assembly, and a drive train is connected between the motor and track. The drive train extends through the suspension arm. The steering control system also passes through the suspension arm and causes the track to flex laterally into a curve in a manner which positions the rider over the flotation centerline of the curved track and thereby maintains balance while negotiating turns. One end of the suspension arm is sprung from the track, and the body is sprung from the other end of the suspension arm.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates in general to embroidery machines and in particular to an improved attachment for embroidering hats and caps.
2. Description of the Prior Art
A typical embroidery machine has one or more heads for performing monogramming and making patches. The head is fixed to a frame and is stationary. A saddle extends from the frame outward directly below the head, the saddle containing a bobbin. The head contains needles with different colors of thread for stitching a workpiece located between the saddle and the head.
The workpiece will be moved as the embroidery occurs, with the head and saddle being stationary. The movement of the workpiece is handled by a carriage which moves back and forth parallel to the axis of the saddle in response to commands from a computer. The carriage has a belt that moves directions perpendicular to the carriage in response to commands from the computer. The workpiece will be secured to the belt by an attachment so that it can be moved with the carriage and the belt. One attachment comprises a hoop which is used for making patches and embroidering jackets and other fabrics that can be readily stretched flat within a frame of a hoop. Another attachment is used for embroidering caps, which cannot be readily stretched flat by a hoop. The term "cap" as used herein refers to all headgear on which embroidering is performed, including certain hats.
The cap attachment includes an arm that attaches to the belt and extends forward from the carriage. A cap driver is located over the saddle and is connected by a brace to the carriage. The cap driver is an assembly which includes a base which moves in unison with the carriage. The cap driver also includes an arcuate member which is pivotally rotatable relative to the carriage about an axis parallel to the saddle axis. A linkage member connects between the arm, which is attached to the belt, and the arcuate member. Movement of the belt perpendicular to the saddle axis causes the arcuate member to pivot rotatably about an axis parallel to the saddle axis.
A cap is clamped into a cap retainer and releasably fastened to the arcuate member of the driver. The cap retainer is a metal framework that fits over the free end of the saddle. The framework of the retainer positions a forward portion of the body of the cap in an arcuate position over the saddle. The carriage and belt move the cap driver and cap retainer to embroider the forward portion of the body of the cap.
While this type of attachment is workable, the passage of the needles into and out of the cap fabric creates upward and downward forces on the cap retainer. The cap driver is connected to the machine only by a cantilevered brace to the carriage and thus is unable to completely restrain the cap retainer from all upward and downward movement. The upward and downward movement tends to make it more difficult to achieve preciseness in the embroidery work.
SUMMARY OF THE INVENTION
In this invention, a guide means is located between the base of the cap driver and the saddle for resisting upward and downward movement of the cap retainer relative to the saddle during embroidering of the cap. The guide means in the preferred embodiment includes a guide bar located at each side of the saddle, the guide bar having an upper surface and a lower surface. A set of upper and lower bearings are mounted at each side of the saddle with one of the guide bars located between. The upper bearings engage the upper surface of the guide bar and the lower bearings engage the lower surface of the guide bar. The guide bars are mounted selectively either to the saddle or to the base, while the bearings are mounted to the other side of the saddle or cap driver base. The upper and lower bearings substantially resist all upward and downward movement but allow relative movement of the saddle and cap driver base along the saddle axis.
Preferably, the guide bars are mounted on a sidewall on each side of the saddle, and the bearings are mounted to the base of the cap driver. The bearings are preferably rollers which will engage the guide bars in rolling contact. In one embodiment, the sidewall on each side of the saddle is part of a downward facing channel member that is secured to and forms the sides and upper surface of the saddle. In another embodiment, the sidewalls are part of an upward facing channel member that secures to the saddle. The sidewalls in this second embodiment are spaced laterally outward from and parallel to the sides of the saddle.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial perspective view of a part of an embroidery machine, showing a saddle having guide bars in accordance with this invention.
FIG. 2 is another partial perspective view of the embroidery machine of FIG. 1, showing also cap driver constructed in accordance with this invention mounted to the machine.
FIG. 3 is a sectional view of the cap driver of FIG. 2, taken along line III--III of FIG. 2.
FIG. 4 is a side elevational view of the cap driver shown in FIG. 3.
FIG. 5 is a sectional view similar to FIG. 3, but showing an alternate embodiment of the cap driver.
FIG. 6 is a side elevational view of the cap driver of FIG. 5.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, the embroidery machine shown has a frame or table 11 which has a central rectangular cavity 12. A saddle 13 extends forward in a candilever manner from table 11. Saddle 13 is surrounded on each side and below by cavity 12. A head 15, shown in phantom, is mounted to table 11 above saddle 13. Head 15 contains needles and different colors of thread for embroidery. A bobbin (not shown) is contained in the free end of saddle 13.
Both saddle 13 and head 15 are stationarily fixed to table 11. The workpiece (not shown) must be moved during the embroidery to form the desired design. This movement is handled by a carriage 17 which is a straight bar that extends across table 11 perpendicular to the axis 19 of saddle 13. Carriage 17 is conventionally mounted on drivers (not shown) which move the carriage 17 forward and backward parallel to saddle axis 19. An endless belt 21 is mounted in carriage 17 and extends perpendicular to saddle axis 19. Belt 21 is driven by rollers which cause movement of belt 21 in directions perpendicular to saddle axis 19, as indicated by the arrows. A computer (not shown) controls the movement of carriage 17 and belt 21 to position the workpiece at the desired locations.
A bracket 23 is rigidly secured to belt 21. An arm 25 secures to bracket 23 and extends forward. The movement of carriage 17 and belt 21 will position arm 25 at desired locations. In one use for the embroidery machine, rather than arm 25, a hoop (not shown) will be attached to bracket 23 for movement with belt 21 and carriage 17. A fabric will be stretched over the hoop.
Referring to FIG. 2, for embroidering caps, a cap driver 27 will be installed over saddle 13 and attached to carriage 17 and arm 25 for movement relative to saddle 13. Cap driver 27 has a base 29, which is also shown in FIG. 3. Base 29 extends over saddle 13 and is secured by a brace 31 to carriage 17. Brace 31 is connected by fasteners 32 to driver 27. Fasteners 33 connect brace 31 to carriage 17. Cap driver 27 will thus move in unison with carriage 17 forward and backward along saddle axis 19.
An arcuate member 35 is rotatably mounted to cap driver base 29 on its forward end. Arcuate member 35 is shown somewhat simplified in the figures, and comprises a semicircular member that extends over saddle 13 and around each side. As shown in FIG. 3, arcuate member 35 extends approximately 240° about an axis parallel with saddle axis 19. Arcuate member 35 will rotate about its axis, which is parallel to saddle axis 19. Guide wheels 37 are fixed to driver base 29 and engage recessed tracks 39 in arcuate member 35. Guide wheels 37 and recesses 39 facilitate rotation of arcuate member 35 relative to base 29 in a plane perpendicular to saddle axis 19. A pivotal linkage bar 41 secures to arm 25 and pivotally secures to arcuate member 35. Movement of arm 25 perpendicular to saddle axis 19 causes rotational movement of arcuate member 35 relative to cap driver 27.
A pair of fasteners 43 are mounted to arcuate member 35 on each side. Fasteners 43 releasably secure a cap retainer 45 to arcuate member 35 for movement therewith. Cap retainer 45 is shown in phantom and is of a conventional type. The bill 47 for the cap being embroidered will extend upward forward of pivotal linkage bar 41 when cap retainer 45 is connected. A forward portion of the body of the cap will be tightly held by cap retainer 45 in an arcuate shape below head 15 (FIG. 1).
Referring also to FIG. 1, a guide bar 49 is secured to each sidewall 51a of a downward facing channel member 51. Channel member 51 has an upper surface 51b and is secured to saddle 13, forming a part of the upper surface and sides of saddle 13. Each guide bar 49 protrudes outward and has an upper and a lower surface. Each guide bar 49 is a rectangular member that extends a substantial distance along saddle 13 parallel with saddle axis 19.
Referring to FIGS. 3 and 4, two sets of upper bearings or rollers 53 will engage the upper surface of each guide bar 49 in rolling contact. One set of lower bearings or rollers 55 locates below each guide bar 49 and engages the lower surface of each guide bar 49 in rolling contact. The engagement of rollers 53, 55 with guide bars 49 allows cap driver 27 to freely roll along saddle axis 19. However, rollers 53, 55 prevent any upward and downward movement of cap driver 27 relative to saddle 13.
As shown in FIG. 3, in the preferred embodiment, each set of rollers 53, 55 is rotatably mounted to a support member 57 which is a rigidly connected part of cap driver base 29. Support member 57 has two parallel side gussets 58, a horizontal plate 59, and a vertical plate 61 which is perpendicular to gussets 58 and horizontal plate 59. Horizontal plate 59 secures by fasteners 60 to brace 31. Vertical plate 61 is located below horizontal plate 59 and is secured to a vertical plate 63 of driver base 29. The support member vertical plate 61 is separated from horizontal plate 59 by an aperture 65 through which saddle 13 passes. Base vetical plate 63 is generally triangular shaped and contains an aperture 66 through which saddle 13 passes. The upper and lower rollers 53, 55 are mounted to each of the side gussets 58.
Driver base 29 also includes a pair of upper flanges 67 located at the upper edges of the base vertical plate 63. Fasteners 32 extend through flanges 67 to fasten brace 31 to upper flanges 67 of base 29. Base 29 of cap driver 27 also includes a pair of outer gussets 69, each being a triangular plate located outward of one of the support member gussets 58. Outer gussets 69 connect flanges 67 to base vertical plate 63 to provide additional rigidity. A pivot pin 71 extends through base vertical plate 63 and into a hub of arcuate member 35, forming the axis of rotation for arcuate member 35. The hub is supported by two radial braces 73.
In the operation of the embodiment of FIGS. 2-4, normally a conventional channel member (not shown) will be on saddle 13 when using the embroidery machine for applications other than embroidering caps. The conventional channel member has the same configuration as channel member 51 but lacks guide bars 49. Guide bars 49 may interfere with the platform (not shown) normally placed on table 11 when using the machine for hoop applications. Consequently, when beginning to embroider caps, the operator replaces the conventional channel member with channel member 51. The operator then attaches cap driver 27 by securing brace 31 to carriage 17. Arm 25 will normally be previously attached to linkage bar 41 as an assembly. Arm 25, along with linkage bar 41, will be secured to bracket 23. Rollers 53, 55 will engage the upper and lower surfaces of guide bars 49. The user secures a cap to cap retainer 45 and fastens cap retainer 45 to arcuate member 35 with fasteners 43, then embroiders the desired design. Rollers 53, 55, in cooperation with guide bars 49, resist upward and downward movement of cap driver 27 during the embroidering.
FIGS. 5 and 6 show an alternate embodiment. Most of the components are the same as in the first embodiment and for convenience may be shown with the same numeral and a prime symbol. The conventional channel member on saddle 13' is not changed when attaching the cap driver in the second embodiment. Rather, an inverted channel member 75 is fastened to the lower side of saddle 13' when cap embroidery is to be performed. Channel member 75 has a lower surface and two upward extending sidewalls 76. Channel member 75 is secured to the lower surface of saddle 13' by fasteners 77. The sidewalls 76 of channel member 75 extend parallel to and along each sidewall of the conventional channel member of saddle 13'. Guide bars 49' are mounted to the sidewalls 76 of channel member 75. Gussets 58' are spaced wider apart than gussets 58 of the first embodiment and about outer gussets 69'. The remaining components are the same, and the operation is the same.
The invention has significant advantages. The guide bars and rollers provide substantial resistance to upward and downward movement, steadying the cap driver during embroidery operations. The additional components do not increase the time for assemblying the cap driver significantly. The guide bars and rollers may be retrofitted to existing equipment.
While the invention has been shown in only two of its forms, it should be apparent to those skilled in the art that it is not so limited but is susceptible to various changes without departing from the scope of the invention. For example, the rollers could be mounted to the saddle and the guide bars to the cap driver.
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An embroidery machine has an attachment for stitching hats and caps. The attachment fits over a saddle of the embroidery machine. A cap driver is carried on the saddle. The base of the cap driver moves parallel to the axis of the saddle in unison with a carriage member. The cap driver has an arcuate member which will rotate pivotally relative to the base. A cap retainer releasably fastens to the arcuate member. A guide bar located between the base of the cap driver and the sides of the saddle engages bearings for resisting upward and downward movement of the cap driver relative to the saddle during stitching of the cap.
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[0001] The present invention relates to a retaining wall block that is resistant to damage and wear caused by the environment it is placed into. The deterioration resistant block is generally a hollowed frame or shell of a deterioration resistant material that is light-weight and is configured to accept and retain any type of filling material. The filling material provides weight and stability to the retaining wall block and also provides weight, stability and security to a retaining wall constructed of such blocks.
BACKGROUND OF THE INVENTION
[0002] The use of retaining walls to protect and beatify property in all types of environmental settings is a common practice in the landscaping, construction and environmental protection fields. Walls constructed from various materials are used to outline sections of property for particular uses, such as gardens or flower beds, fencing in property lines, reduction of erosion, and to simply beautify areas of a property.
[0003] Numerous methods and materials exist for the construction of retaining walls. Such methods include the use of natural stone, poured in place concrete, masonry, landscape timbers or railroad ties. In recent years, segmental concrete retaining wall units, sometimes known as keystones, which are dry stacked (i.e., built without the use of mortar), have become a widely accepted product for the construction of retaining walls. Examples of such units are described in U.S. Pat. No. RE 34,314 (Forsberg) and in U.S. Pat. No. 5,294,216 (Sievert).
[0004] However, many of the materials utilized in the construction of retaining walls are susceptible to deterioration and/or are not very aesthetically appealing. The ability of these retaining walls to withstand sunlight, wind, water, general erosion and other environmental elements is a problem with most retaining wall products.
[0005] A particular concern is the utilization of erosion protection materials in water shorelines. Leaving the shoreline natural can lead to erosion, cause an unmanageable and unusable shoreline, create high maintenance, and inhibit an aesthetically pleasing property. Many materials utilized in retention of shorelines are subject to immediate deterioration and/or are not as aesthetically appealing as one would desire. Furthermore, many materials utilized on shoreline structures are difficult to maintain due to the awkward location in the water and also the prevalent growth and presence of organic materials that can get caught and flourish in such a structure. For example, many lakeshore or ocean side properties utilize riprap as a retention device for prevention of erosion. Riprap is a configuration of large to medium size stones placed along the shoreline. A problem with waterfront properties that use a continuous wall of typical riprap is the shoreline will retain some organic material or will accumulate additional organic material brought in by the water. This usually leads to an unmanageable and aesthetically displeasing shoreline or higher maintenance. Furthermore, the riprap is never uniform in color and size and therefore does not as provide the most aesthetically pleasing shoreline or complete coverage of the shoreline. The lack of uniform shoreline coverage allows for some erosion, collection of various materials and the growth of weeds.
[0006] Another problem with materials normally utilized in the construction of retaining walls, such as poured in place concrete, masonry, landscape timbers, railroad ties or keystones is that regulations in most states and counties prohibit their use in or near bodies of water because of the crumbling or deterioration of the material into the body of water over time. Many of these retaining wall materials dissolve, crumble, break apart and/or float into the body of water for which they line causing problems with the shoreline and pollution of the water. For example, the average life of a concrete block or keystone in water is approximately a couple of years. A need exists for a retaining wall, which would be resistant to such deterioration.
[0007] An additional concern that exists in the construction of retaining walls is the weight of the materials. Concrete blocks, large stones, timbers or keystones can be heavy to move into the wall location and maneuver when constructing the wall. Many locations for which retaining walls are constructed are positioned in awkward terrain. Heavy building materials are difficult to move into the location and furthermore are difficult to position when constructing the retaining wall thereby adding additional cost and labor for installation. However, the heavy materials are needed once the wall is constructed to provide stability and security to the structure. Therefore, the easy to install light-weight units used for the construction of a retaining wall, which can be weighted once placed into position thus retaining the block in position and stabilizing the completed retaining wall, would be beneficial to construction of such structures.
SUMMARY OF THE INVENTION
[0008] As previously mentioned the present invention relates to a retaining wall block that is resistant to damage and wear caused by the environment it is placed into. The deterioration resistant block is generally a hollowed frame or shell of a deterioration resistant material that is light-weight and is configured to accept and retain any type of filling material. The filling material provides weight and stability to the retaining wall block and also ultimately provides stability and security to the retaining wall constructed of such blocks. More specifically, the deterioration resistant block comprises a top panel, a bottom panel, a wall assembly and an optional anchoring device. One or more chambers are created by adjoining the top panel, bottom panel and wall assembly. The chambers are adapted for receiving and retaining fill materials, such as sand, dirt, gravel, pea rock, or any other similar material, which provides the permanent weighting and stability of the retaining wall block.
[0009] Embodiments of the present invention are comprised of a deterioration resistant retaining block for use in constructing retaining walls on a number of property terrains, such as along waterfront properties. The deterioration resistant blocks are particularly useful for terrains near water or underwater due to their resistance to degradation. However, the deterioration resistant blocks could also be used for land applications for those that want a light-weight retaining wall block that can be filled on-site to add weight and stability and doesn't require heavy equipment for moving. Therefore, the deterioration resistant retaining wall block could be utilized to construct any form of wall or fence structure.
[0010] One unique feature of the present invention is the lightweight characteristic of the block before it is filled. As previously mentioned, embodiments of the present invention can be waterproof and may be filled with any type of fill material located at the site, such as rocks, sand, gravel, soil, pea rock or similar materials. The filling characteristic of the deterioration resistant block means that when the block is not filled it is very light-weight. The light-weight feature provides individuals constructing such walls the advantage of easily moving large numbers of the blocks to the site of construction with relative ease. Furthermore, the lightweight characteristic of the blocks allows for easy maneuvering of the blocks into final position when constructing the wall and still allows for the stability of a heavy block after it is filled. These characteristics are met by the block being made of a lightweight material and also configured to receive a heavy fill material once it is about to be placed or has been placed in its final position on the retaining wall.
[0011] Embodiments of the present invention further fills an unmet landscaping need for shorelines in that the deterioration resistant blocks are easily manufactured. Examples of possible manufacturing methods include but are not limited to injection-molding and blow-molding. Also any high volume application for production may be utilized in manufacturing the present invention. The individual units are light-weight, attractive, easy to install, prevent shoreline and other terrain erosion and compliment existing retaining wall block. The deterioration resistant blocks are also waterproof, can withstand ice damage due to their flexible nature and are easily replaced in case of damage. Furthermore, they are rugged and very low maintenance. Additionally, embodiments of the present invention are easily transportable and storable due to their light-weight and possible stacking features.
[0012] Individuals would be more inclined to install block made of a deterioration resistant material themselves rather than cement block, timbers, keystones and the like, because of the ease of installation, due to the lightweight material and also the longevity of the block. The minimum weight of most regular garden block is approximately 30-50 lbs, whereas embodiments of the present invention may be approximately 0.1-10 lbs. Of course, weight may vary depending on the size and materials utilized in manufacturing embodiments of the present invention. Also, as previously mentioned the blocks of the present invention retain the final stability and weight by filling the block with an appropriate fill material either prior to or after it has been permanently installed.
[0013] As previously suggested, embodiments of the present invention are also resistant to deterioration, such as wear, crumbling and breaking, therefore, the deterioration resistant block does not have to be replaced as often and/or increases the lifespan of the retaining wall. The block has approximately the lifespan of at least 5-10 times the life of a regular keystone. The increased lifespan of the block translates to fewer or no occurrences of replacement of individual blocks or the potential complete reconstruction of the entire wall. Furthermore, retaining wall materials, such as concrete block, timbers and keystone, are typically not used in water applications because they dissolve, crumble and/or break down over time and exposure. The durability and resistant characteristics of the present invention reduce and prevent this deterioration, therefore making it very beneficial for all applications that come in contact with water.
[0014] Another consideration relating to the water application of embodiments of the retaining wall block of the present invention is the block's resistance to ice damage when installed around a body of water when it freezes. When ice expands and/or moves it shifts, tears and damages various types materials utilized for shoreline retention, such as keystone, concrete block, rip rap, landscape timbers or anything rigid. Embodiments of the present invention can be manufactured with a material that has flexibility and would flex in a similar way as a Rubbermaid® trash can flexes. Considering that the deterioration resistant block would be filled with a fill material, the deformation would be minimal, but still enough to prevent damage to the retaining wall block and/or the entire wall. Furthermore, upon melting or shifting of the ice the deterioration resistant block would return to its original configuration.
[0015] Another advantage of embodiments of the present invention relates to the high cost of waterfront property and people's inclination to improve their property to keep it well-maintained and aesthetically pleasing. As previously mentioned riprap, is commonly stack up along property shorelines to prevent erosion. The trouble with this shoreline preservation application is that the rock leaves many crevices for organic material to reside and, since it is close to water, the crevices are prominent areas for the growth of vegetation. The advantage of embodiments of the present invention is that they fit next to each other and prevent organic material from getting in-between the blocks, therefore preventing vegetation from growing in such structures.
[0016] In addition, many waterfront properties suffer water damage when water levels rise above the shoreline. The retaining wall block of the present invention is a solution to water retention and erosion problems in such areas of threatening high or rising water levels. Furthermore, the retaining wall block poses a solution in locations where there is a flood plane or areas that are washed out by any type of water movement. Sandbags have been a solution to such problems, but are not a permanent or aesthetically pleasing solution. The retaining wall block can replace sand bags in an area for which a more permanent and aesthetically pleasing alternative is desired.
[0017] As previously suggested, the deterioration resistant retaining wall block can comprise any type of shape, configuration, color and design. In addition the retaining wall block may include any design or color located anywhere on any panel or wall of the block. Furthermore, the utilization of conventional type materials for retaining walls, such as concrete blocks, timbers or keystones, are heavy to install and do not provide long term or permanent solutions, due to the previously mentioned deterioration problems. Therefore, the present invention provides an aesthetically pleasing solution and replacement for materials, including sandbags, presently utilized in retaining wall construction.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] [0018]FIG. 1 is a perspective view of one embodiment of a deterioration resistant retaining wall block.
[0019] [0019]FIG. 2 is a side view of a deterioration resistant retaining wall block, which includes a retaining flange.
[0020] [0020]FIG. 3 is a front view of a deterioration resistant retaining wall block, which includes insertable pegs.
[0021] [0021]FIG. 4 is a perspective view of a deterioration resistant retaining wall block, which includes lockable insertable pegs.
[0022] [0022]FIG. 5 is a perspective view of deterioration resistant retaining wall blocks, which includes apertures for receiving lockable insertable pegs.
[0023] [0023]FIG. 6A is a perspective view of deterioration resistant retaining wall that includes staggered rows and molded designs on the front panel.
[0024] [0024]FIG. 6B is a perspective view of deterioration resistant retaining wall that includes staggered rows and molded designs on the front panel.
[0025] [0025]FIG. 7 is a perspective view of a deterioration resistant retaining wall block containing multiple chambers.
[0026] [0026]FIG. 8 is a top view of a multiple chamber deterioration resistant retaining wall block that includes a top panel with multiple apertures.
[0027] [0027]FIG. 9 is a perspective view of a cover of a deterioration resistant retaining wall block
[0028] [0028]FIG. 10 is a top view of a section of a deterioration resistant retaining wall block.
[0029] [0029]FIG. 11 depicts a top view of a multi-unit deterioration resistant retaining wall block.
[0030] [0030]FIG. 12 depicts a front view of a multi-unit deterioration resistant retaining wall block.
[0031] [0031]FIG. 13 depicts a top view of a multi-unit deterioration resistant retaining wall block with disengaged tabs.
[0032] [0032]FIG. 14 depicts a top view of a deterioration resistant retaining wall block that includes interlocking keys and locks.
[0033] [0033]FIG. 15 depicts a left side perspective view of the deterioration resistant retaining wall block of FIG. 14.
[0034] [0034]FIG. 16 depicts a right side perspective view of the deterioration resistant retaining wall block of FIG. 14.
[0035] [0035]FIG. 17 depicts a top view of the deterioration resistant retaining wall block of FIG. 14.
[0036] [0036]FIG. 18 depicts a front view of a deterioration resistant retaining wall incorporating wings that cover the interlocking keys and locks.
[0037] [0037]FIG. 19 depicts a perspective view of a deterioration resistant retaining wall block with a back panel aperture.
[0038] [0038]FIG. 20 depicts a front view of a deterioration resistant retaining wall block with a back panel aperture.
[0039] [0039]FIG. 21 depicts a perspective view of more than one stackable deterioration resistant retaining wall blocks.
[0040] [0040]FIG. 22 depicts a perspective view of a deterioration resistant retaining wall block with an expansion chamber and sealing cap.
DETAILED DESCRIPTION OF THE INVENTION
[0041] [0041]FIG. 1 depicts one embodiment of the deterioration resistant retaining wall block 10 comprising a top panel 12 , a bottom panel 14 and a wall assembly 16 . FIG. 1 illustrates the top panel 12 , which includes one or more apertures 18 . The apertures 18 may be of any size and shape suitable for the receiving of fill material. The bottom panel 14 includes a relatively flat surface or contoured to rest uniformly with the top panel 12 of one or more blocks 10 positioned below.
[0042] The bottom panel may also include or be adjoined to an anchoring device 20 . FIG. 2 depicts the side view of an embodiment of the present invention, which includes an anchoring device 20 in the form of a retaining flange 22 adjoined to the bottom surface 14 of the block 10 . On a constructed wall, each retaining flange 22 is a wall retention device that operates to inhibit outward movement of the wall. Normally, the retaining flange 22 extends downward from the back of the bottom panel 14 and rests against the back of the retaining block 10 located below the bottom panel 14 . The retaining flange 22 may be a unitary piece extending downward from the back of the retaining block 10 or a series of fingers extending downward from the back of the retaining block 10 .
[0043] Another embodiment of the present invention may include an anchoring device 20 in the form of insertable pegs 24 . In FIG. 3 the insertable pegs 24 are adjoined to the bottom panel 14 and are configured to be securely receivable in the apertures 18 of an additional adjoining top panel 12 of another retaining block 10 . The insertable pegs 24 can be made of any shape and size, which can be securely fit into the apertures 18 of the top panel 12 . The insertable pegs 24 may also function to seal the interior of the retaining block 10 from outside elements. FIGS. 4 and 5 depict another type of peg configuration. FIG. 4 illustrates a bottom panel 14 of one embodiment of the present invention wherein the insertable pegs 24 are lockable. The insertable pegs 24 are positioned on the bottom panel 14 at an angled configuration. The top panel 12 , illustrated in FIG. 5, includes apertures 18 adapted to receive the lockable insertable pegs 24 . In operation a block 10 is maneuvered so that the pegs 24 of one block are inserted into the apertures 18 of another block. The block 10 possessing peg 24 is then turned into position thereby locking the two blocks together. The pegs 24 on a block 10 may also be configured to fit into the apertures of two adjacent blocks positioned below. This application is beneficial if the blocks of adjacent rows are staggered in positioning. See FIGS. 6A and 6B for an illustration of a staggered retaining wall.
[0044] The deterioration resistant retaining block 10 also includes a wall assembly 16 , which is also depicted in FIG. 1. The wall assembly 16 comprises one or more outside walls 25 . Many embodiments of the present invention include wall assemblies 16 that are adjoined to the top panel 12 and bottom panel 14 . The adjoinment of the wall assembly 16 to the top panel 12 and bottom panel 14 creates a chamber 26 located within the retaining block 10 . The chamber 26 is normally filled with materials such as sand, gravel, dirt, cement, water, or other like materials to provide weight and structure stability to the retaining block 10 and the entire retaining wall.
[0045] Another embodiment of the present invention is depicted in FIGS. 7 - 9 . The embodiment shown in FIG. 7 comprises a deterioration resistant retaining block 10 with the top panel 12 removed, wherein the wall assembly 16 defines more than one chamber 26 within the retaining block 10 . The multiple chambers 26 are defined by interior partitions 28 . The interior partitions 28 may also be utilized to add additional support to the retaining block 10 to prevent any possible crushing of the block 10 . FIG. 8 depicts one embodiment of the top panel of a partitioned retaining block 10 . The interior partitions 28 are within the interior of the retaining block 10 and are depicted by dashed lines. The top panel 12 in this embodiment is permanently fixed to the wall assembly 16 and includes multiple apertures 18 to accommodate filling of each individual chamber 26 with appropriate fill material, such as sand, gravel, soil, cement or any other suitable material.
[0046] [0046]FIG. 9 depicts another possible embodiment of the top panel 12 , which is configured in a cover formation that may be adapted to securely fit over the retaining wall block 10 illustrated in FIG. 7. The top panel 12 of this embodiment comprises a closed section 30 that include overlapping edges 32 , which overlap securely over the outside walls of the wall assembly 16 , but does not include apertures. However, the top panel may also secure to the wall assembly 16 in other ways, such as locking tabs, twist locks, clamps, clips, adhesives or any other fastener. The top panel 12 of this embodiment may optionally be hingedly secured to the retaining block 10 by any type of hinge device (not shown), thereby providing a unitary configuration of the retaining wall block 10 .
[0047] Multiple chambers 26 also allow for the retaining block 10 to be cut into various shapes and still maintain a chamber that can receive and retain fill materials. FIG. 10 depicts a section of the retaining block 10 as shown in FIG. 7 wherein the comers have been removed and the block 10 has been cut in half. The ability to cut the retaining block 10 and still retain the same features is particularly useful in preparing ends and awkward segments of retaining walls. Dashed lines depicted in FIG. 9 illustrate alternate cover configurations to conform to the various shapes of a retaining block 10 or portions thereof.
[0048] An additional embodiment of the present invention is depicted in FIGS. 11 and 12. FIG. 11 illustrates a top view of a retaining block 54 wherein multiple units 34 are incorporated into a single block 54 . A single multi-unit block 54 provides the appearance of multiple retaining blocks present in a single structure. The top panel 12 may be a single sheet or multiple sheets of material which covers each unit 34 and optionally includes apertures 18 . The interior of the retaining block 54 of this embodiment includes one or more interior partitions 28 . FIG. 12 depicts the front view of the mutli-unit retaining block 54 , which has the appearance of multiple separate units 34 . These multiple separate units 34 provide the appearance similar to the partial assembly of a retaining wall comprising a plurality of individual blocks, such as depicted in FIGS. 6A and 6B. The multi-unit retaining block 54 may be a unitary structure or may include multiple components, such as a multi-unit block 54 including a single top panel (not shown), similar to the top panel depicted in FIG. 9.
[0049] [0049]FIG. 13 depicts another embodiment of a multi-unit retaining wall block 54 , which includes a common flexible wall 56 . For example flexible wall 56 may be positioned as the back wall of the multi-unit block 54 . In this embodiment of the present invention, tabs 58 may be positioned between each individual unit 34 on the front or back of the multi-unit block 54 . If a curved wall is desired, the tabs 58 may be disengaged, thereby allowing the multi-unit block 54 to be maneuvered into a curved position.
[0050] Another type of anchoring device 20 included in the present invention may be a side locking mechanism. As depicted in FIGS. 14 - 17 one or more interlocking keys 36 and locks 38 may be included in the retaining block. Each key 36 may include a rounded relatively flat cylinder 40 adjoined to a neck 42 that is attached to the side wall 44 of a retaining block 10 . Each lock 38 comprises a partially enclosed cavity 46 , which is configured to receive and securely retain the key 36 when inserted into the lock 38 . As depicted in FIG. 18, wings 48 located on the front of each retaining block 10 function to hide the key and lock system from the view of an observer of the retaining wall. The retaining wall blocks of the present invention may include other side attachments, such as hook and pile attachments (not shown).
[0051] The retaining wall block 10 depicted in FIGS. 19 - 21 includes a top panel 12 , a bottom panel 14 and a wall assembly 16 configured to form one or more chambers 26 . The top panel 12 and bottom panel 14 do not include apertures. Furthermore, the top panel 12 , bottom panel 14 and wall assembly 16 may be a unitary structure or piece. The difference in this embodiment is that the back wall 50 includes one or more back apertures 52 that can be sealed, after it is filled, with a cover or other type of plugging device (not shown). The back apertures 52 can be of any shape and size and may include an aperture that may extend to any or all of the side panels 16 , top panel 12 and/or bottom panel 14 . The embodiment depicted in FIGS. 19 - 21 may also include an anchoring device, such as a retaining flange 22 or any other type of anchoring device. The embodiment of the present invention as depicted in FIGS. 19 is preferably used when retaining walls are embedded into or positioned flush with a hill or other type of ridge thereby further sealing the one or more apertures. The retaining wall block 10 may be filled with a filling material from the back and then placed into position on the retaining wall. Once in position on the retaining wall, the fill material utilized to secure and weight the retaining wall block is maintained within the chamber 26 by the cover or plug and further by the soil, sand, gravel, rock or similar material, which makes up the hill or ridge. An embodiment including multiple units (not shown) may also incorporate into the structure a back panel with an aperture. The presence of an aperture positioned in the back wall 50 may also allow for easy storage and transport due to the stackable capabilities present. For example, an individual block 10 may be inserted into the back of another block 10 , thereby creating a stackable arrangement.
[0052] Another embodiment of the present invention, as depicted in FIG. 22, illustrates a retaining block 10 wherein an aperture 18 may be sealed with a sealing device 60 , such as a cap or plug, after filling the block 10 with an appropriate fill material, such as a liquid. The sealing device 60 may be sealed in a variety of ways known in the art such as screw caps, snap caps, press fit caps, locking caps or any other similar sealing means. For example, the embodiment of FIG. 22 may be filled with water and then sealed with a cap 60 thereby preventing loss of the fill material and providing the weight necessary to give the block 10 stability. In one embodiment, the block 10 may or may not include an expansion chamber 61 , which would allow for expansion of the liquid in situations such as freezing. Embodiments of the expansion chamber 61 may include one or more flexible panels within the chamber or a flexible bladder inserted within the chamber. Alternatively, the utilization of water or other liquids susceptible to freezing may include an adequate amount of antifreeze to prevent freezing of the fill material in cold climates.
[0053] Various embodiments of the present invention, such as those depicted in FIGS. 19 - 21 , also provide for ease in transport and storage due to stackable features. An additional example of a stackable retaining block 10 may be similar to that as shown in FIG. 1, wherein the top panel 12 is removable and allows for the retaining block to be inserted within the chamber of another block. The top panel 12 for such a retaining block 10 may include a cover similar to the cover shown in FIG. 9.
[0054] As previously mentioned, the present invention may be manufactured from a deterioration resistant, substantially rigid composite or polymeric material including, but not limited to, plastic, a rubber composition, fiberglass, or any other similar material or a combination thereof. Preferable materials comprise light-weight and slightly flexible. Generally, the embodiments of the present invention may comprise any type of material that would have the similar characteristics to plastic, vinyl, silicone, fiberglass, rubber or a combination of these materials. It is noted that the material utilized in the present invention should be rigid enough to hold its form upon addition of filling material and also when placed in contact with other objects. Another preferable material may be comprised of a material similar to that utilized in the production of some types of garbage cans or the utilization of recycled rubber from objects such as tires. Such materials would be capable of holding rigidity and still offer flexibility when placed in contact with other objects, such as ice. Also, such materials have the ability to regain its original form when the object or material has been removed.
[0055] Embodiments of the present invention may also vary in appearance. Since embodiments of the present invention may be manufactured by a process such as injection molding, the molds may include any type of design or shape. Furthermore, the front panels of the retaining wall block 10 , as shown in FIGS. 4, 5 and 6 A-B, could be molded in almost any type of configuration. In one embodiment, multiple retaining wall blocks could be molded to include designs that, when positioned on a retaining wall, would complete a larger single design, such as the spelling of a company or school name in large letters or the completion of a large image. Also, since the present invention may be manufactured from a number of different products, such as plastic, a rubber composition or fiberglass, the retaining wall block may comprise any color or a multitude of colors. For example, a retaining wall installed in a beach setting may be manufactured of a plastic or rubber product and be colored in so that organic matter wash up on it would not show up as readily.
[0056] As previously suggested the environment resistant retaining wall block is utilized in the construction of any type of wall or border. In application, a foundation is first created in the area that the wall or border is to be constructed. The foundation preferably is flat and or level and can accommodate one or more retaining blocks 10 . Once a foundation is completed, a first row is laid by filling each individual retaining block 10 with a fill material and placing each individual or multi-unit block, side by side until the row is completed. The filling of the retaining wall block gives it the added weight that it needs to retain its structure and hold it in place. A funneling device may be utilized, which fits securely into the openings or apertures of the retaining wall block to guide fill into the chamber of the block. The first row may be straight or rounded. An example of a rounded first row is depicted in FIG. 20. Upon completion of the first row, additional rows are constructed by performing the same filling process and placing the retaining wall block 10 in the proper position until a continuous retaining wall is completed. Generally, a continuous retaining includes stacked rows wherein individual retaining blocks are placed adjacently to one another thereby eliminating or minimizing cracks or gaps in the wall. Retaining wall blocks 10 may be positioned directly over other retaining wall blocks 10 in lower rows or may be staggered. It is noted that each retaining wall block placed in the retaining wall may be configured to retain and seal the contents of the fill material. This is accomplished by either one or more plugs or covers that seals each open aperture or by enclosing an open aperture with a portion of an adjacent block. Furthermore, the retaining wall blocks 10 of the upper rows may overlap the back of retaining wall blocks 10 of lower rows if a retaining flange 24 is included on the block. In the alternative or additionally, each individual retaining block 10 may be locked into position with adjacent blocks if pegs 24 and apertures 18 or keys 36 and locks 38 are present on the retaining block 10 . Upon completion of the top row of the retaining wall, a cover may be placed over the top row to close the apertures 18 of the top panels 12 or to provide a finishing border to the top of the retaining wall.
[0057] Embodiments of the present invention may also be used in conjunction with regular keystone bricks or stones. A retaining wall constructed in water or along a waterfront property may utilize the retaining wall block of the present invention at water level and below and then the regular keystone or retaining wall materials can be used on top of the retaining wall block of the present invention. The utilization of the retaining wall block of the present invention would be easy to match colors with the conventional retaining wall building materials because the materials utilized to manufacture the present invention can be colored and designed to match virtually any type of retaining wall construction material.
[0058] Furthermore, the retaining wall block may be manufactured in a multitude of different sizes, shapes and configurations. For example, an embankment or steep shoreline could support a retaining wall configured in a step like arrangement or design. Such a structure, may be utilized as a retaining wall and/or a stairway down to the beach or to the water.
[0059] While the invention has been illustrated and described in detail in the drawings and foregoing description, such an illustration and description is to be considered as exemplary and not restrictive in character, it being understood that only the preferred embodiments have been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected.
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The present invention relates to a retaining wall block that is resistant to damage and wear caused by the environment it is placed into. The deterioration resistant block is generally a hollowed frame or shell of a deterioration resistant material that is lightweight and is configured to accept and retain any type of filling material. The filling material provides weight and stability to the retaining wall block and also provides weight, stability and security to a retaining wall constructed of such blocks.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is related to U.S. application titled, “SYSTEM, METHOD AND APPARATUS FOR IMBEDDING A DISPLAY IN A BEZEL,” which was filed on even date herewith; attorney docket number 90104 and inventors Kenneth Lowe, Matthew Blake McRae and John Schindler.
FIELD OF THE INVENTION
[0002] This invention relates to the field of display devices and more particularly to a system for illuminating the bezel of a display device.
BACKGROUND OF THE INVENTION
[0003] Monitor/television devices such as LCD or Plasma televisions have a bezel surrounding the actual display device (LCD panel, Plasma panel, CRT, etc). There have been many colors and varieties of bezels. Most bezels on current monitor/television products are black, while bezels on notebook computers and monitors are often colored to match the color of the shell of the notebook computer or monitor, sometimes white, black, dark blue, etc.
[0004] There are many reasons for different bezel appearances. Some bezels reflect a trade dress of the manufacturer of the monitor/television, often having an embossed logo. Some bezels include a lighted word, usually the manufacturer's name such as, “Vizio.” Some bezels are colored to coordinate, or at least, not clash with their environment. For this reason, many current television manufacturers select a black color for their bezels, since black goes with many different environments.
[0005] Another reason for different colored bezels is to reduce distraction away from the viewed picture, movie, text, etc. In some cases, a strongly contrasting bezel may lead to eye strain. This contrast issue is difficult to address with a fixed-color bezel, since it is difficult to predict what will be displayed in the display area of the monitor/television. For example, a light-colored bezel would blend well with text displayed on a white page but would not blend well with a movie, especially during scenes that are dark. Likewise, a dark or black colored bezel would blend well with the movie but would be distracting when viewing, for example, text on a white page.
[0006] One solution is to provide a monitor or television with interchangeable bezels so that the end user is able to select a bezel from a limited set of colors such as black, white and silver. This helps blend the bezel with the environment, for example when the monitor/television is used in a modern-styled home with predominately white colors, the standard black bezel can be exchanged or covered with a white bezel. This solution does not provide for varying the bezel color/appearance with respect to variations of the displayed subject matter, does not provide indications of internal metadata or status and does not solve the problem of a varying environment such as daytime vs. nighttime viewing. Furthermore, this solution is limited to a small set of bezel colors.
[0007] What is needed is a bezel that changes color based upon user control and/or internal or external data to match the environment and/or displayed content and/or information.
SUMMARY
[0008] The present invention includes a bezel with internal lighting such that, the brightness and color of the bezel are modified based upon either user preference, external parameters (e.g., Internet data, data from other devices in the home, etc.) or internal parameters (e.g., time, content being viewed, etc.).
[0009] In one embodiment, a bezel lighting system is disclosed. The bezel lighting system is mounted on a monitor/television and includes a bezel mounted on a periphery of a face of the monitor/television. The bezel surrounds a display panel and is made of a material capable of transmitting light from within the bezel to outside of the bezel. There is at least one illuminating element situated behind the bezel such that when any of the illuminating elements are energized to emit light, at least some of the light passes through the bezel.
[0010] In another embodiment, a method of controlling a bezel lighting system is disclosed including providing the bezel lighting system mounted on a monitor/television. The bezel lighting system includes a bezel mounted on a periphery of a face of the monitor/television surrounding a display panel and made of a material capable of transmitting light from within the bezel to outside of the bezel. At least one illuminating element is situated behind the bezel such that when any of the at least one illuminating elements is energized to emit light, at least some of the light passes through the bezel. A processing element is interfaced to each of the at least one illuminating element. The processing element displays an on-screen display responsive to an input device (e.g., a remote control 111 ). A bezel lighting option is selected from the on-screen display by a user and responsive to the bezel lighting option, the processing element controls the brightness of each illuminating element the processing element takes off the on-screen display.
[0011] In another embodiment, an illuminated bezel is disclosed. The illuminated bezel is mounted on a periphery of a face of a monitor/television and the illuminated bezel is made of a material capable of transmitting light from within the illuminated bezel to outside of the bezel. There is at least one illuminating element situated behind the illuminated bezel. Each of the illuminating elements are situated such that when any of the illuminating elements are energized to emit light, at least some of the light passes through the illuminated bezel.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The invention can be best understood by those having ordinary skill in the art by reference to the following detailed description when considered in conjunction with the accompanying drawings in which:
[0013] FIG. 1 illustrates a plan view of a monitor/television with bezel of the present invention.
[0014] FIG. 2 illustrates a second plan view of a monitor/television with bezel of the present invention.
[0015] FIG. 3 illustrates a cross-sectional view lengthwise of a typical bezel of the present invention.
[0016] FIG. 4 illustrates a cross-sectional view side-wise of a typical bezel of the present invention.
[0017] FIG. 5 illustrates a first schematic view of a typical monitor/television of the present invention.
[0018] FIG. 5A illustrates a second schematic view of a typical monitor/television of the present invention.
[0019] FIG. 6 illustrates a first flow chart of the present invention.
[0020] FIG. 7 illustrates a second flow chart of the present invention.
[0021] FIG. 8 illustrates a plan view of a first typical on-screen display of the present invention.
[0022] FIG. 9 illustrates a plan view of a second typical on-screen display of the present invention.
DETAILED DESCRIPTION
[0023] Reference will now be made in detail to the presently preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Throughout the following detailed description, the same reference numerals refer to the same elements in all figures. The bezel of the present invention is the facing surface surrounding an image producing surface such as an LCD panel, CRT, Plasma panel, OLED panel and the like.
[0024] Referring to FIG. 1 , a plan view of a monitor/television 5 with bezel 10 of the present invention will be described. The present invention is applicable to any display device that has a bezel such as a monitor/television 5 . Typically, the bezel 10 is situated around the peripheral edge of the display panel 12 , covering the frame and electronics 13 (see FIG. 4 ) of the display panel 12 . For completeness, though not required in the present invention, the monitor/television is shown on a stand 14 . In this view, the bezel 10 is of a first color.
[0025] Referring to FIG. 2 , a second plan view of a monitor/television 5 with bezel 10 of the present invention will be described. The present invention is applicable to any display device that has a bezel such as a monitor/television 5 . Typically, the bezel 10 is situated around the peripheral edge of the display panel 12 , covering the frame and electronics 13 (see FIG. 4 ) of the display panel 12 . Again, for completeness, though not required in the present invention, the monitor/television is shown on a stand 14 . In this view, the bezel 10 is of a second color.
[0026] Referring to FIG. 3 , a cross-sectional view lengthwise of a typical bezel 10 of the present invention will be described. In this view, the top edge of the bezel 10 is visible as well as a surface 7 of the back housing of the monitor/display. Beneath or within the bezel 10 are one or more illuminating elements 20 . Such illuminating elements 20 are known in the art and include devices such as light emitting diodes (LEDs), incandescent lamps, fluorescent lamps, OLEDs, etc. It is also known in the art how to arrange and filter such illuminating elements 20 such that by varying the intensity of individual illuminating elements 20 , multiple blended colors are achieved. For example, the illuminating elements 20 are red, green and blue LEDs or incandescent lamps with red, green or blue coatings. Such illuminating elements 20 are arranged in alteration such that when illuminated, their light mixes to create a mixed color output. Therefore, by illuminating one single illuminating element 20 (e.g., the red LED), the bezel color becomes that of the illuminated LED (e.g., red). By illuminating two illuminating elements 20 (e.g., the red LED and the blue LED), the bezel color becomes that of the illuminated LEDs combined (e.g., red and blue mixed become purple). Preferably, the surface of the bezel 10 is made of a translucent material or is made of a clear material and a diffuser layer covers the illuminating elements 20 to soften the light produced and better mix the colors. The LEDS, in some embodiments are single color LEDS and in other embodiments multiple color LEDS (e.g., red and green emitters in the same LED package).
[0027] Referring to FIG. 4 , a cross-sectional view side-wise of a typical bezel of the present invention will be described. In this view, the top edge of the bezel 10 is visible as well as a surface 7 of the back housing of the monitor/display. In current practice, the bezel covers the display panel frame 13 and as little of the active display area of the display panel 12 as possible.
[0028] Beneath or within the bezel 10 are one or more illuminating elements 20 . Such illuminating elements are known in the art and include devices such as light emitting diodes (LEDs), incandescent lamps, fluorescent lamps, OLEDs, etc. In this view, a diffuser 11 is present in between the illuminating elements 20 and the outer surface of the bezel 10 . The diffuser softens and mixes the light from the individual illuminating LEDs. In some embodiments, the illuminating elements 20 are mounted on a circuit board 21 .
[0029] Referring to FIG. 5 , a first schematic view of a typical monitor/television of the present invention will be described. This figure is intended as a representative schematic of a typical monitor/television 5 and in practice, some elements are not present in some monitors/televisions 5 and/or additional elements are present in some monitors/televisions 5 . In this example, a display panel 12 is connected to a processing element 100 . The display panel 12 is representative of any known display panel including, but not limited to, LCD display panels, Plasma display panels, OLED display panels, LED display panels and cathode ray tubes (CRTs).
[0030] The processing element 100 accepts video inputs and audio inputs selectively from a variety of sources including an internal television broadcast receiver 102 , High-definition Media Inputs (HDMI), USB ports and an analog-to-digital converter 104 . The analog-to-digital converter 104 accepts analog inputs from legacy video sources such as S-Video and Composite video and converts the analog video signal into a digital video signal before passing it to the processing element. The processing element controls the display of the video on the display panel 12 .
[0031] Audio emanates from either the broadcast receiver 102 , the legacy source (e.g., S-Video) or a discrete analog audio input (Audio-IN). If the audio source is digital, the processing element 100 routes the audio to a digital-to-analog converter 106 and then to an input of a multiplexer 108 . The multiplexer 108 , under control of the processing element 100 , selects one of the audio sources and routes the selected audio to the audio output and an internal audio amplifier 110 . The internal audio amplifier 110 amplifies the audio and delivers it to internal speakers 112 / 114 .
[0032] The processing element 100 accepts commands from a remote control 111 through remote receiver 113 . Although IR is often used to communicate commands from the remote control 111 to the remote receiver 113 , any known wireless technology is anticipated for connecting the remote control 111 to the processing element 100 including, but not limited to, radio frequencies (e.g., Bluetooth), sound (e.g., ultrasonic) and other spectrums of light. Furthermore, it is anticipated that the wireless technology be either one way from the remote 111 to the receiver 113 or two way.
[0033] In some embodiments, a light sensor 105 is interfaced to the processing element 100 , for example, a photodiode. The light sensor 105 conveys a value representing the ambient light level in the vicinity of the front of the monitor/television 5 . This value is used, for example, to vary the brightness of the display 12 and/or the graphic display(s) 20 responsive to the ambient light present in front of the monitor/television 5 .
[0034] The processing element 100 further controls the bezel illumination 20 through a bezel driver 118 . In this, serial or parallel outputs from the processing element 100 interface with a bezel illumination driver 118 which is connected to and controls the bezel illumination 20 . It is well known in the industry how to control light emission on devices such as described for the bezel illumination 20 and this is but an example of such. In some embodiments, the functionality of the bezel driver 118 is integrated into the processing element 100 . In some embodiments, the drivers 118 are integrated into the bezel illumination 20 . Any other known configuration is anticipated and functions within the present invention. It is well known how to control Liquid Crystal Displays (LCD), plasma displays, OLED displays, electronic paper, Light Emitting Diode (LED) arrays, etc. For example, if the bezel illumination 20 comprises an array of LEDS, the bezel driver 118 , in one embodiment, the bezel driver 118 uses pulse-width modulation to control the brightness or each group of LEDS (e.g., the wider the pulse width, the brighter that group of LEDS will shine). Alternately, in another embodiment, the bezel driver 118 controls the current flowing through the group of LEDS to control the brightness or each that group.
[0035] In some embodiments, the television/monitor 5 is connected to a network, such as the Internet or local area network. In these embodiments, a network interface 120 monitors the network and transfers data back and fourth between the processing element 100 and the network. In some embodiments, the network is a wired network such as an Ethernet network. In other embodiments, the network is wireless such as WiFi/802.11 and a wireless interface 122 is provided.
[0036] Referring to FIG. 5A , a second schematic view of a typical monitor/television of the present invention will be described. This figure is intended as another representative schematic of a typical monitor/television 5 and in practice, some elements are not present in some monitors/televisions 5 and/or additional elements are present in some monitors/televisions 5 . In this example, a display panel 12 is connected to a processing element 100 . The display panel 12 is representative of any known display panel including, but not limited to, LCD display panels, Plasma display panels, OLED display panels, LED display panels and cathode ray tubes (CRTs).
[0037] The processing element 100 accepts video inputs and audio inputs selectively from a variety of sources including an internal television broadcast receiver 102 , High-definition Media Inputs (HDMI), USB ports and an analog-to-digital converter 104 . The analog-to-digital converter 104 accepts analog inputs from legacy video sources such as S-Video and Composite video and converts the analog video signal into a digital video signal before passing it to the processing element. The processing element controls the display of the video on the display panel 12 .
[0038] Audio emanates from either the broadcast receiver 102 , the legacy source (e.g., S-Video) or a discrete analog audio input (Audio-IN). If the audio source is digital, the processing element 100 routes the audio to a digital-to-analog converter 106 and then to an input of a multiplexer 108 . The multiplexer 108 , under control of the processing element 100 , selects one of the audio sources and routes the selected audio to the audio output and an internal audio amplifier 110 . The internal audio amplifier 110 amplifies the audio and delivers it to internal speakers 112 / 114 .
[0039] The processing element 100 accepts commands from a remote control 111 through remote receiver 113 . Although IR is often used to communicate commands from the remote control 111 to the remote receiver 113 , any known wireless technology is anticipated for connecting the remote control 111 to the processing element 100 including, but not limited to, radio frequencies (e.g., Bluetooth), sound (e.g., ultrasonic) and other spectrums of light. Furthermore, it is anticipated that the wireless technology be either one way from the remote 111 to the receiver 113 or two way.
[0040] In some embodiments, a light sensor 105 is interfaced to the processing element 100 . The light sensor 105 conveys a value representing the ambient light level in the vicinity of the front of the monitor/television 5 .
[0041] In this example, the processing element 100 further controls the bezel illumination 20 through a controller 117 . The controller 117 interfaces either directly to the bezel illumination 20 or through a bezel driver 118 to the bezel illumination 20 . In this, serial (e.g., I2C) or parallel outputs from the processing element 100 interface with the controller 117 which is connected to and controls the bezel illumination 20 either through dedicated drivers 118 or directly (not shown). It is well known in the industry how to control the elements of the bezel illumination 20 and this is but an example of such. In some embodiments, the controller 117 , bezel drivers 118 and bezel illumination 20 are powered by auxiliary power (power supplied when the television/monitor 5 is in standby mode). In these embodiments, the controller 117 continues to drive the bezel illumination 20 , even when the television/monitor 5 is in auxiliary mode (e.g., appears to be off). In some embodiments, the controller 117 and/or drivers 118 are integrated into the bezel illumination 20 . Any other known configuration is anticipated and functions within the present invention. It is well known how to control Liquid Crystal Displays (LCD), plasma displays, OLED displays, electronic paper, Light Emitting Diode (LED) arrays, etc. For example, if the bezel illumination 20 comprises an array of LEDS, the bezel driver 118 , in one embodiment, the bezel driver 118 uses pulse-width modulation to control the brightness or each group of LEDS (e.g., the wider the pulse width, the brighter that group of LEDS will shine). Alternately, in another embodiment, the bezel driver 118 controls the current flowing through the group of LEDS to control the brightness or each that group.
[0042] In some embodiments, the television/monitor 5 is connected to a network, such as the Internet or local area network. In these embodiments, a network interface 120 monitors the network and transfers data back and fourth between the processing element 100 and the network. In some embodiments, the network is a wired network such as an Ethernet network. In other embodiments, the network is wireless such as WiFi/802.11 and a wireless interface 122 is provided.
[0043] Referring to FIG. 6 , a first flow chart of the present invention will be described. This is an exemplary program flow executed within the processing element 100 upon reception of a command 30 from the remote control 111 . The command 30 is tested to see if it is a bezel control 32 . If not, the existing processing continues as known in the art. If it is, the command 30 is tested to determine if it is a request to change the color 40 of the bezel 10 . If it is, in this example, an on screen display is presented to change the color 44 . Other methods are also anticipated to effect the color change such as sequencing through a series of colors, etc.
[0044] If it isn't a request to change the color 40 of the bezel 10 , then the command 30 is tested to determine if it is a request to change the color pattern of the bezel 50 . If it is, in this example, an on screen display is presented to change the color pattern 54 . Other methods are also anticipated to effect the color change such as sequencing through a series of color patterns, etc.
[0045] If it isn't a request to change the color pattern of the bezel 50 , then the command is tested to determine if it is a request to turn on meta-data 60 . If it is, in this example, a meta-data flag is set 64 . The use of this flag is described with FIG. 7 .
[0046] If it isn't a request to use meta-data 60 , then the command 30 is tested to determine if it is a request to turn off the bezel 70 . If it is, in this example, the bezel is turned off 74 . If it isn't a request to turn off the bezel 70 , processing continues.
[0047] This is but one example of a program running in the processing element 100 that controls the color and or brightness of the bezel illumination 20 . Other methods, either more or less complicated are anticipated for monitoring various internal and external parameters and settings.
[0048] Referring to FIG. 7 , a second chart of the present invention will be described. This is an exemplary program flow executed within the processing element 100 periodically (e.g., at fixed intervals or at a particular instance such as during re-trace, etc.). First, the meta-data flag is tested to see if it is enabled 80 . If not enabled, the flow is done. If it is enabled 80 , the meta-flag is tested to determine which type of meta-data is to be used in controlling the bezel color 80 . For example, if the meta-data is set to use the current channel 82 , then the color of the bezel 10 is set based on the current channel being used 84 . For example, if the Discovery Channel is being watched, then the bezel 10 color is set to a first color (e.g., green) and if the Weather Channel is being watched, the bezel 10 color is set to a second color (e.g., blue). In this way, the viewer has information regarding which channel is being watched by the color of the bezel 10 , even when a commercial is playing.
[0049] If the meta-data is not set to use the current channel 82 , the meta-flag is then tested to determine if the current outside weather is to be used in controlling the bezel color 86 . For example, if the meta-data is set to use the weather 86 , then the color of the bezel is set based on the current weather 88 . For example, if internal data to the processing element 100 indicates that it is sunny, the bezel color is set to a first color (e.g., yellow). If internal data to the processing element 100 indicates that it is rainy, the bezel color is set to a second color (e.g., gray). In this way, the viewer has information regarding the weather while watching their favorite program.
[0050] If the meta-data is not set to use the weather 86 , the meta-flag is then tested to determine if the current time is to be used in controlling the bezel color 90 . For example, if the meta-data is set to use the current time 90 , then the color of the bezel is set based on the current time 92 . For example, if the current time indicates that it is morning, the bezel color is set to a first color (e.g., yellow). If current time indicates that it is night time, the bezel color is set to a second color (e.g., black or off). In this way, the bezel color varies with the time.
[0051] Many types of dynamic and static data are anticipated to be used to control the bezel illumination 20 , including but not limited to, stock market, holidays, voicemail waiting, recording indication, favorite show starting, approach of a tornado or other storm, incoming messages, etc.
[0052] Referring to FIG. 8 , a plan view of a first typical on-screen display of the present invention will be described. Many user interfaces are known in the industry and the color selection user interface of FIG. 8 is but one example. In this, the user is presented with a heading “Select Color” 120 along with a grid of possible colors 121 . In the grid of possible colors 121 are multiple color choices 123 , one of which is highlighted 122 . Using an input device, such as a television remote control, the user/viewer maneuvers the highlighting 122 to the color choice desired, and then selects the “DONE” feature 126 . Responsive to the “DONE” feature 126 being activated, the bezel is changed to the selected color. If, instead, the user/viewer wishes to turn off the bezel color, the user/viewer selects the “OFF” feature 124 and the bezel illumination is turned off.
[0053] Referring to FIG. 9 , a plan view of a second typical on-screen display of the present invention will be described. Many user interfaces are known in the industry and the meta-data selection user interface of FIG. 9 is but one example. In this, the user is presented with a heading “Select Format:” 130 along with several choices 132 / 134 / 136 / 138 / 140 . The user/viewer maneuvers to the desired choice 132 / 134 / 136 / 138 / 140 using an input device such as the arrows on a television remote control 111 . Once at the desired choice 132 / 134 / 136 / 138 / 140 , the user/viewer selects that choice using, perhaps, the select key, then selects the “DONE” feature 142 , whereby the processing element 100 sets up the bezel illumination accordingly. For example, if “Fixed Brightness” 132 is selected, the bezel is set to a static level of brightness. If “Based on Time of Day” 134 is selected, the brightness is varied based upon an internal algorithm based upon the time-of-day. If “Based on Room Brightness” 136 is selected, the brightness of the bezel is varied responsive to the ambient light in front of the monitor/television 5 . If “Random” 138 is selected, the brightness is randomly set. If “Based on Content” 140 is selected, the brightness and color of the bezel is set by an algorithm that evaluates the predominant colors in the current image. Such algorithms are known. For example, a histogram of colors is used to determine the most prevalent color being displayed.
[0054] Many types of dynamic and static data are anticipated to be used to control the bezel illumination 20 , including but not limited to, stock market, holidays, voicemail waiting, recording indication, favorite show starting, approach of a tornado or other storm, incoming messages, etc. The data that is portrayed on the bezel display 20 includes information, events, notifications, content data. The data or meta data is held or derived from within the television/monitor (e.g., current channel) or information from external sources such as the Internet, other devices, phone system, etc. Information includes data such as date, time etc. Events include data such as phone ringing, incoming message, etc). Notifications include data such as a favorite show is currently being received, new voicemail, etc. Content data includes data such as channel, show, etc. The data may come from within the TV, over a local area network, over a wide area network (e.g., Internet) or over a connection to a device that is connected to the television/monitor 5 .
[0055] Equivalent elements can be substituted for the ones set forth above such that they perform in substantially the same manner in substantially the same way for achieving substantially the same result.
[0056] It is believed that the system and method of the present invention and many of its attendant advantages will be understood by the foregoing description. It is also believed that it will be apparent that various changes may be made in the form, construction and arrangement of the components thereof without departing from the scope and spirit of the invention or without sacrificing all of its material advantages. The form herein before described being merely exemplary and explanatory embodiment thereof. It is the intention of the following claims to encompass and include such changes.
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An application for a bezel with internal lighting includes at least one illuminated element situated behind a monitor/television bezel. The brightness and color of the illuminating elements and hence the bezel appearance are modified based upon either user preference or an internal or external parameters such as time, content being viewed, recording status, etc.
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FIELD OF THE INVENTION
[0001] The invention relates to barley cultivars having grain with ultra-high beta glucan content and uses thereof.
BACKGROUND OF THE INVENTION
[0002] Barley is one of the world's most important cereal crops. In addition to containing eight essential amino acids, antioxidants, vitamins and minerals essential to health, barley is also high in dietary fiber.
[0003] Beta-glucans (β-glucans) are an important component of the dietary fiber present in barley. β-glucan has many known health benefits and thus, the inclusion of barley in the diet can have many beneficial effects. Indeed, eating whole-grain barley has been shown to help regulate blood sugar and eating barley also helps to lower cholesterol levels, reduces visceral fat and lowers the incidence of heart disease (see e.g., Nilsson, A.; et al. (2006) European Journal of Clinical Nutrition 60 (9): 1092-1099; Pick M, et al. (1998) Int J Food Sci Nutr. 49(1):71-78; Zeković D B, et al. Critical Reviews in Biotechnology. 2005;25(4):205-230; Jue Li, et al. Nutrition—November 2004 (Vol. 20, Issue 11, Pages 1003-1007, Abumweis S S, et al. European Journal of Clinical Nutrition. 2010;64(12):1472-1480; Choi J S, et al. Molecular nutrition & food research. 2010 Jul;54(7):1004-1013; D. El Khoury, et al. J Nutr Metab. 2012; 2012; Carlo Agostoni et al. EFSA Journal 2011;9(12):2471; Shimizu, C. et al. Plant Foods and Human Nutrition, March 2008; 63(1):21-5).
[0004] Given the health benefits of β-glucan consumption, a barley cultivar having grain with ultra-high beta-glucan content is highly desirable.
[0005] Fortunately, as will be clear from the following disclosure, the present invention provides for these and other needs.
SUMMARY OF THE INVENTION
[0006] In exemplary embodiments, the disclosure provides barley plants having grain with ultra-high beta-glucan content, a seed thereof, tissue culture of regenerable cells therefrom, and/or a protoplast produced from the tissue culture. In one exemplary embodiment, the disclosure provides a barley plant having grain with ultra-high beta-glucan content, or a part thereof, produced by growing the seed.
[0007] In some exemplary embodiments, the disclosure provides a barley plant having grain with ultra-high beta-glucan content, or a part thereof, having all the physiological and morphological characteristics of the CM1, representative seed of such line having been deposited with the American Type Culture Collection on May 17, 2012 and having been assigned ATCC accession No. PTA-12911, a seed thereof, a tissue culture of regenerable cells produced therefrom and/or protoplast produced from the tissue culture of regenerable cells.
[0008] In other exemplary embodiments, the disclosure provides a hybrid barley plant, wherein the lineage of at least one parent plant comprises a barley plant having grain with ultra-high beta-glucan content, having all the physiological and morphological characteristics of the variety CM1, representative seed of such line having been deposited with the American Type Culture collection on May 17, 2012 and having been assigned ATCC accession No. PTA-12911. In some exemplary embodiments, the disclosure provides grain from the hybrid barley plant wherein the grain has ultra-high beta-glucan content. In one exemplary embodiment, the at least one parent plant of a hybrid barley plant is the barley plant CM1, representative seed of such line having been deposited with the American Type Culture collection on May 17, 2012 and having been assigned ATCC accession No. PTA-12911. In another exemplary embodiment, the at least one parent plant, CM1, is crossed to a second parent plant, wherein the second parent plant is “Tetonia” and wherein the hybrid barley plant has grain with ultra-high beta-glucan content. In one exemplary embodiment, the hybrid barley plant from a cross between CM1 and “Tetonia” is a member selected from the group consisting of 10ARS313-791, 10ARS313-930, 10ARS313-854, 10ARS313-924, 10ARS313-963, 10ARS313-355, 10ARS313-782, 10ARS313-777, 10ARS313-575, 10ARS313-418, 10ARS313-428, 10ARS313-831 and 10ARS313-849.
[0009] In still other exemplary embodiments, the disclosure provides a barley plant having grain with ultra-high beta-glucan content of the variety CM1, representative seed of such line having been deposited with the American Type Culture collection on May 17, 2012 and having been assigned ATCC accession No. PTA-12911, or a selfed progeny thereof or an F1 hybrid thereof wherein the barley plant has grain with ultra-high beta-glucan content.
[0010] In still other exemplary embodiments, the disclosure provides grain from a barley plant known as CM1, representative seed of such line having been deposited with the American Type Culture collection on May 17, 2012 and having been assigned ATCC accession No. PTA-12911 or a progeny thereof.
[0011] Other features, objects and advantages of the invention will be apparent from the detailed description which follows.
DETAILED DESCRIPTION OF THE INVENTION
Definitions
[0012] The term “plant” as used herein refers to whole plants, plant bodies, plant organs (e.g., leaves, stems, flowers, roots, etc.), seeds, plant tissues, plant cells and progeny of same. In an exemplary embodiment, a plant cell includes callus. In another exemplary embodiment, a plant organ includes a root, a leaf, a flower and/or the like. The term “plant” refers to plants of any variety of ploidy levels, including polyploid, diploid, haploid and hemizygous.
[0013] The term “barley plant having grain with ultra-high beta-glucan content” as used herein, refers to a barley plant ( Hordeum vulgare . L) which produces grain that has a beta-glucan content of greater than about 13% beta-glucan by dry weight. Typically, a “barley plant having grain with ultra-high beta-glucan content” has a beta glucan content that is in a range that is between about 14% to about 19% by dry weight. An exemplary “barley plant having grain with ultra-high beta-glucan content” is CM1.
[0014] The term “beta glucan” or β-glucan as used herein, refers to non-starch polysaccharides of D-glucose monomers comprising B-(1,4)-linked glucose units separated every 2-3 units by β-(1,3)-linked glucose.
[0015] The term “grain” or any gramatically equivalent expression as used herein, refers to grain kernels from a barley plant. In some exemplary embodiments, the term “grain” refers to grain kernels from a barley plant having grain with ultra-high beta-glucan content.
[0016] The term “cross” or “crossing” as used herein refers to a simple X by Y cross, or the process of backcrossing, depending on the context.
[0017] The term “backcross” as used herein refers to a process in which a breeder crosses a hybrid progeny line back to one of the parental genotypes one or more times.
I. Introduction
[0018] In an exemplary embodiment, the invention provides a barley cultivar having grain with ultra-high beta-glucan content.
[0019] β-glucans have known health benefits (see e.g., Food and Drug Administration: FDA (2006) Food Labeling: ‘Health claims: Soluble dietary fiber from certain foods and coronary heart disease’. In: Code of Federal Regulation Title 21 Part 101) and barley is known to have more β-glucan content than any other grain. Despite the relatively high beta-glucan content, there is an upper limit of about 8.5% β-glucan content in the known barley cultivars with some variation due to growing conditions (see e.g., Izydorczyk M S, et al. J Agric Food Chem. 2000 Apr;48(4):982-9; Holtekjo/len A K, et al. Food Chemistry. 2006;94(3):348-358; Hang, A., et al. (2007) Crop Sci. 47: 1754-1760).
[0020] Given the health benefits of β-glucan consumption and overall value of barley as health food, it would be of great benefit to have available barley cultivars having the highest possible β-glucan content. Fortunately, the variety CM1 disclosed herein below is a barley cultivar having ultra-high beta glucan content.
[0000] II. Mutagenesis and Selection to Produce a Barley Plant having Ultra-High Beta-Glucan Content.
A. General Methods
[0022] Methods disclosed herein utilize routine techniques in the field of barley genetics and cultivation. Basic terminology in the field of genetics and cytogenetics can be found e.g., In: Robert C. King, William D. Stansfield, A Dictionary of Genetics , sixth edition 2002, Oxford University Press; basic texts in barley genetics and cultivation include, e.g., Barley Science: Recent Advances from Molecular Biology to Agronomy of Yield and Quality , Gustavo A Slafer, Jose Luis Molina-Cano, Roxana Savin, Jose Luis Araus and Ignacio Romagosa eds; CRC Press, Mar 12, 2002-665 pages and Barley: Genetics, Biochemistry, Molecular Biology and Biotechnology , Peter R. Shewry ed. Oxford University Press, USA (1992).
B. Mutagenisis of Barley
[0024] Induced mutations have been extensively used to improve main crop species, including cereals such as barley ( Hordeum vulgare L). See e.g., A. R. Prina, E. A. Favret (2008) Hereditas 98(1):89-94. Sodium azide is typically used in a wide range of concentrations for barley mutagenesis (e.g., 10 −5 to 10 −2 M, see e.g., Hodgdon et al, 1979 Barley Genetics Newsletter, Vol. 9: 29-33). As is known in the art, mutation frequencies positively correlate with the concentrations of the chemical used. However, higher concentrations may have lethal effect on seed germination.
[0025] In exemplary embodiments, the concentration of sodium azide used for mutagenesis of barley as disclosed herein is in a range that is between about 1 mM and about 2 mM.
C. Selection of Mutants having High Beta-Glucan Content
[0027] In exemplary embodiments, barley plants having grain with ultra-high beta-glucan content are selected by screening plants grown from mutagenized seed for a beta-glucan content that is at least about 30% greater than the beta-glucan content of the corresponding parent plant. Thus, in some exemplary embodiments, barley plants having ultra-high beta-glucan content are barley plants grown from mutagenized seed which have beta-glucan content that is at least about 30% greater that the beta-glucan content of the parent plant.
[0028] In other exemplary embodiments, barley plants having grain with ultra-high beta-glucan content are selected by screening plants grown from mutagenized seed for a beta-glucan content that is at least about 40% greater than the beta-glucan content of the corresponding parent plant. In still other exemplary embodiments, barley plants having grain with ultra-high beta-glucan content are selected by screening plants grown from mutagenized seed for a beta-glucan content that is at least about 50% greater, at least about 60% greater, at least about 70% greater, at least about 80% greater, at least about 90% greater, at least about 100% greater, at least about 110% greater, at least about 120% greater, at least about 130% greater, at least about 140% greater, at least about 150% greater, at least about 175% greater, at least about 200% greater, at least about 250% greater, at least about 300% greater, than the beta-glucan content of the corresponding parent plant.
III. Measuring Beta-Glucan Content
[0029] In general, beta-glucan content is measured using any method known in the art. In some exemplary embodiments, beta-glucan is determined using e.g., AACC International Approved Method 32-23; a Megazyme mixed-linkage β-glucan assay kit (Megazyme International Ireland Ltd., Bray Business Park, Bray, Co. Wicklow, Ireland), etc. In one exemplary embodiment, beta-glucan content is measured according to the method of Hu and Barton 2008 (Gongshe Hu and Charlotte Burton (2008) Cereal Chemistry 85: 648-653, which is incorporated herein by reference).
IV. Measuring Fiber and Vitamin E Content
[0030] In general, total fiber and soluble fiber are measured by any method known in the art e.g., AACC International Approved Methods-AACC Method 32-05.01. Total Dietary Fiber; AACC International Approved Methods-AACC Method 32-07.01. Soluble, Insoluble, and Total Dietary Fiber in Foods and Food Products AACC International Approved Methods-AACC Method 32-07.01. Soluble, Insoluble, and Total Dietary Fiber in Foods and Food Products.
IV. Uses for Barley Plant Having Ultra-High Beta-Glucan Content
[0000]
A. Use in Breeding Programs
[0032] In exemplary embodiments, a barley plant having grain with ultra-high beta glucan content is used in barley breeding programs to provide hybrid barley plants having grain with ultra-high beta-glucan content. In some exemplary embodiments, at least one parent plant in a cross to provide hybrid barley plants having grain with ultra-high beta-glucan content is the variety CM1 representative seed of which has been deposited with the American Type Culture Collection (ATCC), Patent Depository, on May 17, 2012 and which has the ATCC accession number is PTA-12911(See section V. hereinbelow). In other exemplary embodiments, at least one parent plant in a cross to provide hybrid barley plants having grain with ultra-high beta-glucan content is the variety CM1 and the CM1 parent is crossed to a second barley plant that is not CM1. The second barley plant can be any barley plant. In some exemplary embodiments, the second barley is the variety “Tetonia” (see e.g., D. E. Obert et al. Registration of ‘Tetonia’ Barley Journal of Plant Registrations (2008) Vol. 2 No. 1, p. 10-11). In other exemplary embodiments, the second barley plant is “Transit”(see e.g., Obert D E, Hang A, Hu G, Burton C, Saterfield K, Evens C P, Marshall J M, and Jackson E W. 2011. Registration of ‘Transit’ High β-Glucan Spring Barley. Journal of Plant Registrations 5: 270-272).
B. Use in Food Production
[0034] Processed barley grain products are used as components of consumer products in the form of thickeners, binders or extenders. Thus, in some exemplary embodiments, a barley plant having grain with ultra-high beta-glucan content is used to produce food products and/or nutritional supplements.
[0035] Barley having grain with ultra-high beta-glucan content is processed for human and/or animal consumption by any method known in the art (see e.g., Barley for Food and Health: Science, Technology, and Products, Rosemary K. Newman, C. Walter Newman 2008, 246 pgs.; Wheat, Rice, Corn Oat Barley and Sorghum Processing Handbook (Cereal Food Technology) by NIIR BOARD OF CONSULTANTS & ENGINEERS (2006))
V. Deposit Information
[0036] A deposit of a barley plant having ultra-high beta-glucan content, CM1, disclosed hereinbelow and recited in the appended claims has been made with the American Type Culture Collection (ATCC), Patent Depository, 10801 University Blvd., Manassas, Va. 20110, U.S.A. The date of deposit was May 17, 2012. All restrictions upon the deposit have been removed, and the deposit is intended to meet all of the requirements of 37 C.F.R. 1.801-1.809. The ATCC accession number is PTA-12911. The material description is: Barley ( Hordeum valgare ) seeds: CM1. The deposit will be maintained in the depository for a period of 30 years, or 5 years after the last request, or for the effective life of the patent, whichever is longer, and will be replaced as necessary during that period.
[0037] The following examples are offered to illustrate, but not to limit the invention.
EXAMPLES
Example 1
[0038] The following example illustrates construction and testing of a barley plant having grain with ultra-high beta-glucan content. In particular the following Example illustrates construction of the line known as: CM1, which was deposited with the American type Culture Collection on (May 17, 2012), and which has been assigned ATCC accession number PTA-12911.
[0039] Ultra-high beta-glucan barley lines were created by chemical mutagenesis using sodium azide. Seed from four known barley lines, CDC Alamo (see e.g., Rossnagel et al. (1999) “ CDC Alamo 2- Row Hulless Zero Amylose Barley ” Barley Newsletter, Vol.43), Waxbar, Baronesses, and 03AH 2229, were treated with sodium azide at a concentration of sodium azide at 1 mM.
[0040] The Waxbar variety was protected with a Plant Variety Protection Certificate in 1988 under the PV number of 8800084 in PVPO list of U.S. protected Varieties. The Certificate is now expired. The major character of the Waxbar is the amylose-free hulless spring variety.
[0041] Baronesses is a 2-row feed barley developed in Germany and seeds are produced by the Western Plant Breeders company in the United States. It is still a protected variety in US under the PV number of 9300211. The major character of this cultivar is high yield. It has been used as control in the yield trials.
[0042] 03AH2229 is a line developed in the local research program in Aberdeen, Idaho. 03AH2229 is a 2-row hulless spring barley line derived from the cross between Azhul and Thuringa. It has beta-glucan at about 8-9% but yield is low (see e.g., Agronomic Performance of Food Barley at Pendleton and Moro Steve Petrie, et al. (2007) Agricultural Experiment Station, Oregon State University Special Report 1074 June 2007). 03AH2229 was chosen based on the assumption that it is better adaption to the climate condition in southeast Idaho region. This mutagenized population has not been used for high beta-glucan mutation screening yet.
[0043] Mutagenisis of the above disclosed barley varieties was mutagenized according to the following method:
Mutagenesis Method
[0000]
1. Cold Soak seed (500 g-1000 g) in 5 L tap water (use 6 L Flask) for 16 Hours in 0 to 4° C.
2. Rinse seed with 5 L 20° C. tap water for 4 times
3. Soak seed in 5 L tap water for 4 hours at 20° C.
4. Rinse seed with deionized (distilled will work) water for 4 times
5. Fill Flask or beaker with 4.5 L deionized water
6. Add 0.5 L 1 M KH2PO4 (pH=3.0), swirl to mix
7. Go to the fume hood to add 5.0 mL 1 M NaN3 (in distilled water), mix thoroughly
8. Connect aeration system to flask for 2 hours. Swirl every 0.5 hours. Pull tired bags every 15 min. if using beaker.
9. Remove solution and rinse the seeds for 3 times in tap water
10. Wash seeds for 0.5 hour in running water
11. Dry seeds on paper towel in fume hood overnight
12. Planting or store in paper bag up to 2 weeks
[0056] After Sodium Azide treatment, the seeds (called M0 seeds) were planted in the field in Aberdeen in 2006 spring. Individual plants were harvested separately. Two seeds from each harvested plant were collected. Those seeds (called M1 seeds) were pooled together for the same barley line. So, total four pools of M1 seeds were obtained for CDC Alamo, Waxbar, Baronesse, and 03AH2229, respectively.
[0057] The M1 seeds were planted in the field in Aberdeen in the spring of 2007, plants were harvested and threshed individually. The cleaned seeds from this generation (called M2 seeds) was subjected for beta-glucan measurement. The lines with significant changes of beta-glucan content compared to their corresponding wild-type lines were selected as the candidate mutants.
[0058] The criteria for selecting the mutant candidate was that the changes of beta-glucan content from grains was at least 30% compared to the wild-types.
[0059] About 4000 M2 seeds from each family were screened from CDC Alamo, Waxbar, and Baronesses. A particular mutation called CM1 was identified from the mutagenized population of CDC Alamo line in 2007.
[0060] The forth population of 03AH2229 has not been screened for beta-glucan mutant yet.
Characterization of the CM1 Mutant
[0061] CM1 was first noticed by its extreme high beta-glucan content in the M2 seeds screening. To confirm the significant changes of beta-glucan, CM1 was planted in greenhouse in 2007 winter, in Aberdeen field in 2008, and greenhouse in 2009 winter, grains of CM1 from those plants in different growth conditions were measured for beta-glucan contents and compared to the wild-type plants in the same growth conditions. All the tests confirmed that CM1 was consistently 100% more in beta-glucan content than that in the wild-type.
[0062] The ranges of the beta-glucan content in CM1 grains are 14% to 18% at dry matter based. In general, as is known in the art, beta glucan content may vary to some extent with the growth conditions. Environmental factors such as e.g., water and nitrogen supply during the seed development stage can affect beta glucan content. Typically, dry conditions enhance beta-glucan content in grains and nitrogen decreases the beta-glucan content. Thus, the beta-glucan content of the same barley line can vary somewhat in different locations and years.
[0063] To evaluate the beta-glucan content in CM1 more precisely, we developed near iso-genic lines. The near isogenic lines were developed by crossing CM1 to its wild-type parental line of CDC Alamo in 2007. F1 seeds were planted in greenhouse and F2 seeds were planted in 2008 in the Aberdeen field with both parents as controls. Four F3 plants with the same beta-glucan contents of CM1 were pooled together to represent the mutant near iso-genic line while the four plants with the similar wild-type CDC Alamo beta-glucan content were pooled together to represent the wild-type near isogenic line. Those near iso-genic lines were then used in planting and testing for fiber compositions of the grains. Comparing to the corresponding wild-type near isogenic lines which has 7.2-8.5% of beta-glucan, CM1 has about 100% increased in beta-glucan in grains. Data is shown in Table 1. Beta-glucan content was measured using methods known in the art (Hu and Burton, Cereal Chemistry 85: 648-653).
[0064] The CM1 mutant was further characterized for total fiber as well as for the water extractable fibers of arabinoxylan and glucomann using methods known in the art (Total Dietary Fiber: The MegaZyme Kit for total dietary fiber (K-TDFR from MegaZyme International, Ireland) was used. Performance of the assay was followed the instructions from the manufacture. Glucomann content in grains: The MegaZyme Kit K-GLUM (MegaZyme International, Ireland) was used. Performance of the assay was followed the instructions from the manufacture. Arabinoxylan content in grains: The MegaZyme Kit K-GLUM (MegaZyme International, Ireland) was used. Performance of the assay was followed the instructions from the manufacture.
[0065] Characterization of the CM1 mutant by measurements of other fibers in the grains revealed that other water extractable fibers of arabinoxylan and glucomann are also increased by 53% and 50%, respectively, compared the wild-type parental CDC Alamo. CDC Alamo is the parental line of CM1. Total fiber of CM1 grains is increased by 66%. Seeds look thinner, but plants showed normal biological characters in terms of seed germination, plant height, leaf color and size, heading dates, flower development, and seed set.
[0066] The high fibers in CM 1 make it a valuable material for food industry. Fibers and Vitamin E contents are associated with the high beta-glucan content because the near iso-genic lines were used for those tests.
[0067] In addition to the high fiber content, CM1 mutant also showed Vitamin E content that was higher than that in the corresponding wild-type. Vitamin E was measured by methods known in the art (see Jackson et al, (2008) Crop Sci. 48:2141-2152) by Dr. Mitchell Wise lab in USDA-ARS, Madison, Wis.
[0068] Content of total tocol is 110 mg/Kg in CM1 compared to the 76 mg/Kg in the wild-type. The increase is about 45%. Since Vitamin E is related to the anti-oxidation, the CM1 may potentially provide some stress tolerance for the plants and extending the shelf-life for the food products.
[0069] The experimental data for this mutant is summarized in Table 1.
[0070] More importantly CM 1 does not have clear negative impact on plant biological traits in field based on the eyeball observation and some data collected in Table 2.
[0071] Yield potential was not available due to the limitation of seeds.
[0000]
TABLE 1
Summary of Fiber related traits tested in CM1 mutant and it's
near iso-genic wild-type line. The seeds were harvested from Aberdeen
field in 2009. The value was reported as the dry matter based
Traits
CM1
Wild-type
Beta-glucan
17.90%
9.70%
Total Fiber
30.9%
18.6%
Glucomann
0.28%
0.16%
Water extractable
0.95%
0.62%
Arabinoxylan
Vitamin E (mg/Kg)
110
76
[0000]
TABLE 2
Agronomic data for CM1 and its corresponding
wild-type in Aberdeen field, 2011
Traits
CM1
Wild-type
Plant Height
42 Inch
42 Inch
Heading dates
180
180
100 seed weight (g)
3.45
4.45
Example 2: Deposit Information
[0072] Representative of, but not limiting the invention, Applicants have deposited seeds from CM1, with the American Type Culture Collection.
[0073] Applicants have made available to the public without restriction a deposit of at least 2500 seeds of a barley plant having ultra-high beta-glucan content i.e., CM1, with the American Type Culture Collection (ATCC), Rockville, Md. 20852. The deposit was made May 17, 2012 and having been assigned ATCC accession No. PTA-12911.
[0074] The deposit will be maintained in the ATCC depository, which is a public depository, for a period of 30 years, or 5 years after the most recent request, or for the effective life of the patent, whichever is longer, and will be replaced if a deposit becomes nonviable during that period.
Example 3
[0075] The following example illustrates the use of the barley plant having ultra-high beta-glucan content CM1, representative seed having been deposited May 17, 2012 under ATCC Accession No. PTA-12911, as a parent to in a genetic cross to improve the nutritional value of barley lines. The cross produces progeny having ultra-high beta-glucan content as well as other characteristics shared with the parental CM1 line.
Utilization of the CM1 to Improve Barley Nutritional and Other Qualities
[0076] As discussed above, CM1 showed very high content of beta-glucan and other dietary fibers. Thus, it is useful for improving the nutritional value of barley by using it as parental line crossing to other barley lines in the breeding procedure.
[0077] Crosses we have made include CM1×Tetonia and CM1×Transit. We are currently making more crosses using CM1 as a parent including CM1×winter lines of barley.
[0078] Tetonia is a very yield barley line released from our breeding program in Aberdeen (D. E. Obert et al. Registration of ‘Tetonia’ Barley Journal of Plant Registrations (2008) Vol. 2 No. 1, p. 10-11). Tetonia has low beta-glucan content (about 6% in out tests). This cross combines the high beta-glucan, vitamin E and fibers from CM1 and high yield from Tetonia in the new varieties.
[0079] Our experiment in cultivar development using CM 1 as parent confirmed the inheritance of the high beta-glucan. We made a cross between CM1 and Tetonia. In the 780 F2 plants of CM1×Tetonia, we identified 180 lines with more than 11.0% of beta-glucan. Among those 180 lines, fifty of them showed 14% or higher beta-glucan contents in grains. Further, there are 85 F3 lines with more than 14% beta-glucan from the cross of CM1×Tetonia. The 180 F2 lines were advanced in head rows and 53 were selected based on beta-glucan contents and field performance. In 2013 Lines were advanced to F5::7 generation. Those 53 lines showed at least 14% BG contents. Those lines will be further evaluated with yield, agronomic traits, and beta-glucan, in multiple years and locations. The best lines will be selected as new food barley cultivars.
[0080] Transit is another high beta-glucan line released from our breeding program recently (Obert D E, Hang A, Hu G, Burton C, Saterfield K, Evens C P, Marshall J M, and Jackson E W. 2011. Registration of ‘Transit’ High β-Glucan Spring Barley. Journal of Plant Registrations 5: 270-272). Cross between CM1 and Transit is expected to use genetic factors contributing to beta-glucan content from traditional high beta-glucan genetic background from transit and a specific mutation from CM1. This cross should have a chance to obtain the best combinations of beta-glucan related genetic factors.
[0081] Thirty F5::7 lines from Tetonia×CM1 were evaluated in the Advanced Yield Nursery at Aberdeen, Id. in 2013. Barley lines were planted in 5×10 Ft plot with three replications. Thirteen lines with good yield potential and ultra-high β-Glucan were selected for further tests. The yield potential and β-Glucan data of the 13 lines are summarized.
[0000]
TABLE 3
Yield and β-Glucan contents of 13 selected F5::7 lines
of Tetonia × CM1 from 2013 Aberdeen Field
Line ID
Yield (Bu/A)
% yield of CM1
BG %
CM1
81
100
15
10ARS313-791
89
110
14
10ARS313-930
107
129
16
10ARS313-854
90
111
14
10ARS313-924
92
114
14
10ARS313-963
90
111
15
10ARS313-355
90
111
14
10ARS313-782
91
112
15
10ARS313-777
98
121
14
10ARS313-575
93
115
14
10ARS313-418
93
115
14
10ARS313-428
95
117
14
10ARS313-831
88
109
19
10ARS313-849
96
119
14
[0082] It is understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes in light thereof will be suggested to persons skilled in the art and are to be included within the spirit and purview of this application and scope of the appended claims.
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The present disclosure relates to barley plants having grain with ultra-high beta-glucan content, methods for constructing said barley plants, grain therefrom and uses thereof. In an exemplary embodiment, present disclosure provides a barley plant having grain with ultra-high beta-glucan content known as CM1.
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ORIGIN OF THE INVENTION
The invention described herein was made by an employee of the United States Government and may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to the fields of biophysics, tissue regeneration, tissue culture, and neurobiology. More specifically, the present invention relates to the use of an electromagnetic field, and preferably, a time varying electromagnetic field, for potentiation of or controlling the growth of biological cells and tissue, such as mammalian tissue. More specifically, the present invention relates to the use of an electromagnetic field for controlling the growth of neural cells and tissues. The preferred embodiment utilizes two-dimensional conducting plate electrodes and may be applied to conventional, two dimensional tissue cultures or to three-dimensional cultures. Three dimensional cultures may be achieved in actual microgravity or by rotating wall vessel technology which simulates the physical conditions of microgravity, and in other, conventional three-dimensional matrix based cultures. The electromagnetic field, preferably a time varying electromagnetic field, is achieved in the vicinity of the electrode by passing, through the electrode, a time varying current.
2. Description of the Related Art
Growth of a variety of both normal and neoplastic mammalian tissues in both mono-culture and co-culture has been established in both batch-fed and perfused rotating wall vessels ( 1 - 2 ), and in conventional plate or flask based culture systems. In some applications, growth of three-dimensional structure, e.g., tissues, in these culture systems has been facilitated by support of a solid matrix in the form of biocompatible polymers and microcarriers. In the case of spheroidal growth, three-dimensional structure has been achieved without matrix support ( 3 - 6 ). NASA rotating wall tissue culture technologies have extended this three dimensional capacity for a number of tissues and has allowed the tissue to express different genes and biomolecules. Neuronal tissue has been largely refractory, in terms of controlled growth induction and three dimensional organization, under conventional culture conditions. Actual microgravity, and to a lesser extent, rotationally simulated microgravity, have permitted some enhanced nerve growth (Lelkes et al). Attempts to electrically stimulate growth have utilized static electric fields, static magnetic fields, and the direct passage of current through the culture medium, though not the induction of a time varying electromagnetic field in the culture region.
Neuronal tissue comprises elongated nerve cells composed of elongated axons, dendrites, and nuclear areas. Axons and dendrites are chiefly responsible for transmission of neural signals over distance and longitudinal cell orientation is critical for proper tissue formation and function. The nucleus plays the typical role of directing nucleic acid synthesis for the control of cellular metabolic function, including growth. In vivo, the neuronal tissue is invariably spatially associated with a system of feeder, or glial, cells. This three dimensional spatial arrangement has not been reproduced by conventional in vitro culture. Investigators, Borgens RB et al, and others, have utilized static electric fields in an attempt to enhance nerve growth in culture. (Valentini et al) with some success to either alter embryonic development or achieve isolated nerve axon directional growth. However, actual potentiation of growth or genetic activity causing such, have not been achieved. Mechanical devices intended to help grow and orient three dimensional mammalian neuronal tissue are currently available. Fukuda et al. (7) used zones formed between stainless steel shaving blades to orient neuronal cells or axons. Additionally, electrodes charged with electrical potential were employed to enhance axon response. Aebischer (8) described an electrically-charged, implantable tubular membrane for use in regenerating severed nerves within the human body. However, none of these devices utilize channels of cell-attractive material, neither do they apply a time varying electromagnetic field, or a static electrical or magnetic field. Additionally, no use is made of simulated or actual microgravity techniques for pure neuronal, or mixed, neuronal and feeder cell cultures. The prior art is deficient in its lack of effective means for growing three dimensional mammalian neuronal tissue in the proximity of, or directly upon the surface, of a current carrying electrode (which may be bioattractive and directly adherent to the cells). Furthermore, the use of a time varying current to induce a corresponding time varying electromagnetic field, in the vicinity of the growing culture, to potentiate or spatially direct cell growth is not part of the prior art.
SUMMARY OF THE INVENTION
The present invention relates to a system and method for culturing biological cells, such as mammalian cells, within a culture medium. The cells are exposed to an electromagnetic field, which, in the preferred embodiment, is a time-varying electromagnetic field. In the preferred embodiment, this field is generated by a conductive electrode, adjacently spaced from the incubating cells, carrying a time varying electrical current. The electrode, in one case, is in direct galvanic contact with the culture media and cells, and in another case, it is placed external to the culture apparatus in a galvanically isolated condition. Preferably, a 10 hertz square wave of 1-6 milliamperes, and with nearly zero time average, is passed through the electrode, suitably from corner to opposite comer of a square metallic conductive plate. The cells, such as neurons in this case, were, in one embodiment, grown directly on the electrode surface, composed of a biocompatable material. In another embodiment, the cells were grown within a container under the influence of a time varying electromagnetic field from an electrode external of and adjacent to the container, galvanically isolated from the media and culture within the container.
The growing cells may actually be attracted and trophically supported by more supportive electrode material or coatings. Furthermore, channels may be incorporated in the culture vessel and lined with growth substrate which may be electrically conductive. In one embodiment, a time varying electromagnetic field is induced in the region of the channel by passing the time varying current through a conductor placed along the channel. This arrangement will further direct growth by the combined effect of the field and trophic materials.
In the preferred embodiment, the presence of the time varying electromagnetic field potentiates the growth of nerve and other tissue. The time varying field may be induced by either: 1) a time varying current within a conductor, or 2) a time varying voltage between fixed conductors. In one embodiment, for example, the culture is placed nearby a conductor through which a time varying current is passed, or between parallel plates upon which a time varying voltage is applied. In both cases, a time varying electromagnetic field results within the area of interest, i.e., in the region of the cell culture.
The system and process are utilized in combination with known tissue culture processes to produce enhanced cell growth, directed cell growth, and tissue formation and organization.
As will be understood from the description to follow, the system is operable to up or down regulate the activity of specific genes. In general, growth promoting genes are up regulated and growth inhibitory genes are down regulated. The effect is shown to persist for some period after termination of the applied time varying field. This persistent, growth promoting effect subsides after a period of some days, and the cells return to a growth state characterized by controls, having never been exposed to the fields. This is beneficial in certain applications, in that medical applications for clinical medical care, i.e. nerve regeneration, are therefore safer than if the “pseudo transformed” state persisted. The set of gene transformations, associated with the time varying electromagnetic field, also promote the ability of the growing tissue to adhere and thrive on substrates by the induction of genes leading to the secretion of extracellular materials favorable to the tissue microenvironment.
Several methods of producing the time varying electromagnetic field in the vicinity of the living tissue culture are encompassed. In one embodiment, an array of conductive current carrying elements (or voltaic electrodes) are arranged so as to intensify or focus the time varying electromagnetic (EM) field onto the culture. Each embodiment is characterized by a method for application of the time varying field to the target tissue, such as neuronal, for stimulation of growth, or repair or induction of changes in gene activity patterns. The term “field generator” is used herein to represent these various embodiments for generating the time varying electromagnetic fields. In its simplest form, it is a conductive electrode, placed near the target cells, through which current is directed from a controlled waveform current source.
As suggested above, in one embodiment, the field generator is in the form of a conductive channel mounted on or embedded in a disc of biocompatable material. (FIG. 11) One or more of these discs may be then placed within a rotational bioreactor so as to obtain the beneficial culture conditions associated therewith. The combination of the stimulatory electromagnetic field with the rotational environment, known to permit morphological expression beyond conventional culture, is particularly effective. This is because the induced pattern of growth enhancing genes is permitted to be ultimately expressed, as cell growth and tissue formation, without mechanical inhibition from the culture apparatus. Also the inherent growth advantages well known in the rotational systems is synergistic with the growth stimulation derived from the time varying electromagnetic field. The conditions may be further optimized by utilizing actual microgravity, in space. In this application, mechanical rotation of the cell culture vessel is not required but may be utilized to achieve mixing and sufficient mass transfer to sustain a healthy culture. Other forms of mixing may be introduced as necessary to achieve adequate mass transfer for each embodiment.
In one embodiment, illustrated in FIGS. 10 and 11, slip-ring contacts or their equivalents are electrically connected to the ends of the channels, and an external power source is provided for applying the time varying electrical current defining the waveform through the channels. In another embodiment, the channel consists of a pair of parallel, mutually spaced conductors across which a time varying voltage is applied. This also achieves the time varying electromagnetic field but restricts it to the region between the parallel electrodes, which is advantageous for directing localized growth according to a desired physical pattern. The present invention also relates to a system and method for culturing primarily two dimensional mammalian cells facilitated by a time varying electromagnetic field. The electrodes may either be in direct galvanic contact or galvanically isolated from the target cells. The present invention provides a strategy to re-engineer nerve tissue and myoneural junctions and can be used medically for axonal regeneration.
In one embodiment of the present invention, there is provided a system for growing three dimensional mammalian cells, comprising a rotating wall vessel containing a cell-rich medium and a formed cell growth substrate. A time varying electromagnetic field is applied to enhance tissue growth which may occur on a shaped substrate. The electromagnetic field may be generated by means such as by directing the current waveform directly through a conductive substrate (or substrate layer) or by projecting the field from an external antenna, or electrode adjacent to and spaced from the medium, the spacing being sufficiently small relative to the strength of the electromagnetic field to induce effectual levels of electromagnetic field within the medium, in accordance with the particular application. A time varying electromagnetic field may be emitted from a nearby plate or other suitable “antennae,” or a time varying voltage may be applied across suitable electrodes (such as plates) to produce the time varying electromagnetic field. The field generation system may either be rotating with the vessel or fixed, and spaced from, the rotating vessel. The rotating wall vessel can be a rotating wall perfused vessel or a rotating wall batch-fed vessel.
The time varying electromagnetic field is advantageously produced by a varying electrical potential in the form of a square wave having a frequency of approximately ten cycles per second. In one embodiment, a current of about ten milliamps, conducted between opposite comers of a metallic conductor, produces a stimulatory time varying electromagnetic field extending several centimeters from the plate surface. In practice, the range of frequency and oscillating electromagnetic field strength is a parameter which may be selected to for achieving the desired stimulation of particular tissues, cells, or genes, and for providing the appropriate amount of up/down regulation of these genes.
In one embodiment of the present invention, the cell growth susbtrates or carriers are spherical disks containing multiple parallel channels (FIG. 10) which are coated with a bioattractive material. The bioattractive material has a longitudinal axis across which the time varying electrical potential is applied and through which a time varying current is conducted. The mammalian cells adhere to the bioattractive material and are free to orient, as they grow. Representative bioattractive materials include titanium, zirconium and platinum.
The class of mammalian cells preferably is selected from the group consisting of neuronal cells, normal human neuronal progenitor cells (NHNP), and a cell responding to the time varying electromagnetic field. It will be understood by those of ordinary skill in the art that the teachings of the present invention apply to other cell types.
In another embodiment of the present invention, there is provided a method of culturing mammalian cells in the claimed system, comprising the steps of inoculating the cells into the vessel containing a culture medium, rotating the vessel to enhance the proliferation of the cells and, in one embodiment, to initiate the attachment of the cells to microcarrier spheres or beads suspended within the culture medium, applying a time varying electromagnetic field to the culture medium, cells, and cell carriers, and measuring the growth of the cells. Preferably, the vessel is rotated at a speed from about 2 RPM to 30 RPM, and the time varying electromagnetic field is generated by a time varying current passed through a conductor with RMS value of about 1 to 1,000 ma. In one embodiment, a range of about 1 mA to 6 mA is used.
In still another embodiment of the present invention, there is provided a system for growing two-dimensional neural cells, comprising a petri dish containing a cell culture medium and an electrode placed in the center of the petri dish. In this embodiment, the electrode serves as the field generator. Preferably, the neural cells are applied directly on the electrode. As a result, the neutral cells exhibit accelerated growth.
In yet another embodiment of the present invention, there is provided a system for growing two-dimensional neural cells further comprising a slide placed on the electrode. Preferably, the neural cells are applied, e.g., bubbled, on the slide instead of directly contacting the electrode, and preferably, the current producing the waveform is applied at a strength range of from about 1 mA to about 100 mA, and, in one embodiment, suitably from about 1 mA to 6 mA.
In still another embodiment of the present invention, there is provided a method of treating an individual having diseased neuronal cells, comprising the steps of growing neuronal cells in the claimed two- or three- dimensional systems and transplanting the neuronal cells into the individual. Such diseases include Parkinson's disease, diseases of neuromuscular junction and Alzheimer's Disease. Neural trauma can also be treated in same methodology.
In yet another embodiment of the present invention, the time varying electromagnetic field (or electrical potential) induces cellular response including cellular control of growth and differentiation at gene level. Preferably, the cellular control of growth and differentiation is to suppress or enhance growth regulatory functions at gene level. Still preferably, the gene is associated with increased tissue and cell proliferation.
Other and further aspects, features, and advantages of the present invention will be apparent from the following description of the presently preferred embodiments of the invention given for the purpose of disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
So that the matter in which the above-recited features, advantages and objects of the invention, as well as others which will become clear, are attained and can be understood in detail, more particular descriptions of the invention briefly summarized above may be had by reference to certain embodiments thereof which are illustrated in the appended drawings. These drawings form a part of the specification. It is to be noted, however, that the appended drawings illustrate preferred embodiments of the invention and therefore are not to be considered limiting in their scope.
FIG. 1 shows a petri dish with cells in a concentrated bubble placed on the metal electrode in the center of the dish.
FIG. 2 shows normal human neuronal progenitor (NHNP) cells grown in conventional tissue culture procedures.
FIG. 3 shows the perimeter of non-waveform influenced normal human neuronal progenitor cells 24 hours after the experiment.
FIG. 4 shows neural tube formation within nornal human neuronal progenitor cells under the influence of waveform.
FIG. 5 shows neural tube generation within normal human neuronal progenitor cells under the influence of waveform.
FIG. 6 shows the composition of waveform-influenced neural tissue 24 hours after the exposure.
FIG. 7 shows the waveform-influenced normal human neuronal progenitor cells 24 hours after the exposure.
FIG. 8 shows a close-up of waveform-influenced normal human neuronal progenitor cells.
FIG. 9 shows waveform-influenced normal human neuronal progenitor cells 24 hours after the exposure.
FIG. 10 shows prototype of the system 1 , consisting of silicon plates 2 , fluid coupling 3 , slip rings 4 , a rotating wall pressure vessel (RWPV) 5 , electrical conductor 6 (i.e., an electrical conductive bioattractive inlay strip), a perfusion inlet 7 , perfusion outlet 8 , a stand for the rotating wall pressure vessel 9 and a source of time varying electrical current 10 .
FIG. 11A is a plan view of one of the disc-shaped silicon plates 2 , showing a central opening 11 about which rotation occurs, the electrical conductors 6 , and electrical contacts 12 connected to the strips at opposite ends thereof. FIG. 11B is a side view of the silicon plate 2 , demonstrating the electrical contacts 12 and the electrical conductive strips, in the form of bioattractive inlays 6 .
DETAILED DESCRIPTION OF THE INVENTION
As used herein, the term “bioattractive material” shall refer to materials to which a cellular material will attach.
As used herein, the term “longitudinally orient” shall refer to orientation in an elongated cordlike fashion.
As used herein, the term “parallel channels” shall refer to electric channels which are designed to provide constant output to all the electrodes simultaneously.
As used herein, the term “cell carriers” shall refer to microcarrier beads, scaffolds and matrices which support the growth and/or attachment of cellular materials.
As used herein, the term “rotating wall batch-fed vessel” shall refer to slow turning lateral vessel (STLV) and high aspect rotating vessel (HARV).
As used herein, the term “Corona Effecft” shall refer to the accelerated growth pattern of neuronal cells electrically potentiated by waveform.
In one preferred embodiment, the present invention is directed to the growth of three dimensional mammalian neuronal tissue using an electrically conductive strip in the form of a channel or mold coated with a bioattractive or biocompatable material to which an electrical potential is applied to longitudinally orient the neural cells or axons as they adhere to the bioattractive material which is suspended in an axon rich medium.
A Specifically, in the present embodiment, the apparatus includes a bioreactor chamber vessel employing electrically insulative, biocompatable spherical disks of a material such as silicon. These disks rotate inside the pressure vessel. Each disk has multiple parallel channels cut into its surface. The channels have a semicircular cross-section and contain an electrically conductive inlay in the form of a channel-shaped conductive strip of a bioattractive material such as zirconium, titanium and platinum. Each channel strip 6 has an electrical contact on each longitudinal end that is used to create and control an electrical potential along the length of the strip. The vessel is filled with a medium and the disks are rotated within a medium containing axons. The cells adhere to the electrically conductive bioattractive inlay material. The desired longitudinal cell orientation and therefore the structure of the resulting tissue is affected and/or controlled by the electrical stimulus.
The present invention is also directed to the growth of two dimensional mammalian neuronal tissue using electrodes. The electrodes are either in direct contact or not in contact with the target cells.
In one embodiment of the present invention, there is provided a system for growing three dimensional mammalian cells, comprising a rotating wall vessel containing a cell-rich medium, cell carriers placed within the vessel and an electrical potential applied to the cell carrier. Preferably, the rotating wall vessel can be a rotating wall perfused vessel or a rotating wall batch-fed vessel.
In one embodiment of the present invention, the cell carriers are spherical disks containing multiple parallel channels, which are coated with a bioattractive material. More preferably, the bioattractive material has a longitudinal axis across which the electrical potential is applied. The mammalian cells adhere to the bioattractive material and are therefore oriented longitudinally upon the electrical stimulus. Representative bioattractive materials include titanium, zirconium and platinum.
In the methods of the present invention, the mammalian cell is selected from the group consisting of a neuronal cell, a normal human neuronal progenitor cell (NHNP) and a cell responding to waveform. A person having ordinary skill in this art will be able to apply the teachings of the present invention to other cell types.
In another embodiment of the present invention, there is provided a method of culturing mammalian cells in the claimed system, comprising the steps of inoculating the cells into the vessel, rotating the vessel to initiate the attachment of the cell to the cell carriers, applying an electrical potential to the cell carriers and measuring the growth of the cells. Preferably, the vessel is rotated at a speed from about 10 RPM to 30 RPM, and the electrical potential is applied at a strength range of from about 1 mA to about 6 mA.
In still another embodiment of the present invention, there is provided a system for growing two-dimensional neural cells, comprising a petri dish containing a cell culture medium and an electrode placed in the center of the petri dish. The electrode is charged with a waveform. Preferably, the neural cells are bubbled directly on the electrode. As a result, the neutral cells exhibit accelerated growth.
In yet another embodiment of the present invention, there is provided a system for growing two-dimensional neural cells further comprising a slide placed on the electrode. Preferably, the neural cells are bubbled on the slide instead of directly contacting the electrode. Preferably, the waveform is applied at a strength range of from about 1 mA to about 6 mA.
In still yet another embodiment of the present invention, there is provided a method of treating an individual having diseased neuronal cells, comprising the steps of growing neuronal cells in the two or three dimensional systems disclosed herein and transplanting the grown neuronal cells into the individual. Such diseases include Parkinson's disease, diseases of neuromuscular junction and Alzheimer's Disease. Neural trauma can also be treated with this same methodology.
In yet another embodiment of the present invention, the waveform (or electrical potential) induces a cellular response including cellular control of growth and differentiation at gene level. Preferably, the cellular control of growth and differentiation is to suppress or enhance growth regulatory functions at gene level. Still preferably, the gene is associated with embryogenesis.
The following examples are given for the purpose of illustrating various embodiments of the invention and are not meant to limit the present invention in any fashion.
EXAMPLE 1
Cells
Normal human neuronal progenitor cells (NHNP) were pooled from three donors. As controls, normal human neuronal progenitor cells were grown in conventional tissue culture following standard cell culturing procedures.
EXAMPLE 2
Materials
GTSF-2 medium with 10% FBS, Ciprofloxacin and Fungizone was used to culture the cells. 1×PBS, Collagenase, DNase and Trypsin were purchased from Clonetics. The cells were grown on 12-100 mm Petri dishes (tissue culture coated or not coated). Electrodes were made of platinum and stainless steel. A waveform generator was used to generate the waveform in a strength of 1-6 mA (AC) square wave, 10 Hz variable duty cycle.
EXAMPLE 3
Electrically Potentiating Cell Growth When Electrode is in Direct Contact with the Target Cells
Initially, a metal electrode was placed inside a petri dish and centered.
Normal human neuronal progenitor cells were seeded at 2×10 5 cells in 0.7 ml of media and carefully dropped on the electrode in a concentrated bubble (FIG. 1 ). Cells were incubated for 2 days. Second day after seeding is considered day 0 of the experiment. At day 0, each dish was given 15 ml of media and waveform was applied to seven electrodes. Cells were observed under a dissecting microscope and fed with 15 ml of media at day 3, and 13 ml every three days at day 6, 9 and 12. At day 14, the cells were fed again with 13 ml of media. At day 17, the cells were incubated for 10 minutes in a Collagenase/DNase cocktail, then trypsin was directly applied to the cocktail and the cells were further incubated for 3 more minutes. Before the media was added to deactivate trypsin, the cocktail mix was pipetted up and down several times. The cells were washed twice with 1×PBS, reapplied with the media and placed on ice. The cells were counted, assessed for viability.
To examine the accelerated growth of cells 48 and 72 hours after waveform was discontinued, cells were treated the same as above, except that after day 14 treatment, instead of harvesting, two dishes from the non-waveform group (control) and two dishes from the waveform group were randomly chosen and re-seeded at 9×10 5 cells in two new petri dishes each, with a total of four dishes. Cells from one set (#11 waveform and control #6) were counted and photographed 48 hours after seeding, and cells from the second set (#12 waveform and control #7) were counted and photographed 72 hours after seeding.
To examine accelerated growth pattern “Corona Effect” after the electrical potentiation, the same treatment was applied to the cells without harvesting. A dish each from waveform group and non-waveform group were chosen randomly. Cells still attached in sheet from were lifted off of the electrodes carefully and placed in new petri dishes with medium, and then photographed 24 hours later.
EXAMPLE 4
Electrically Potentiatiny Cell Growth When Electrode is not in Direct Contact with the Target Cells
Initially, a metal electrode was placed inside a petri dish and centered. A slide was carefully placed on the electrode under sterile conditions. Normal human neuronal progenitor cells were seeded at 2×10 5 cells in 0.7 ml of media and bubbled on the slide. Cells were incubated for 2 days. 25 ml of media were applied and two 1000 μl pipetman blue tips were placed in the dish to anchor the slide to bottom of the dish. The second day after seeding was considered day 0 of the experiment. At day 0, each dish was given 25 ml of media and waveform was applied to six of the twelve electrodes.
Cells were observed under a dissecting microscope and fed with 25 ml of media every three days at day 3, 6, 9 and 12. At day 14, the cells were fed again with 25 ml of media. At day 18, the cells were incubated for 10 minutes in a Collagenase/DNase cocktail, then typsin was directly applied to the cocktail and the cells were further incubated for 3 more minutes. Before the media was added to deactivate trypsin, the cocktail mix was pipetted up and down several times. The cells were washed twice with 1×PBS, reapplied with the media and placed on ice. The cells were counted, assessed for viability and then replated at 100,000 per plate. The remaining waveform and non waveform slides were fixed and refrigerated for staining at a later date.
EXAMPLE 5
Electrically Potentiated Growth of Cells
Normal human neuronal progenitor-pool cells exposed to a time varying electromagnetic field (waveform), either in direct contact or not in direct contact with the electrode, displayed an accelerated growth rate and different morphology as compared to non waveform cells (control), i.e., cells not subject to the time varying electromagnetic field (see Table 1 and Table 2, FIGS. 2 - 9 ). After the application of the time varying electromagnetic field or waveform, the cells preferentially aligned, while cells without waveform exposure showed random pattern. Cells in direct contact with the electrode remained stimulated up to at least 72 hours after waveforn was removed (Table 3); while those not in direct contact with the electrode once removed from waveform continued to experience accelerated and long term stimulation growth pattern even after 168 hours (Table 4). Viability was also higher in the cells exposed to the waveform (Table 4). Cells were suspended easily with the Collagenase/DNase then trypsin sequence.
TABLE 1
*Cell Count and Viability at Harvest (day 17)
NHNP-POOL
CELL COUNT
VIABILITY
HARVEST
Waveform 1
860,000
98%
17 days
Waveform 2
1,000,000
98%
17 days
Waveform 3
1,000,000
98%
17 days
Waveform 4
1,300,000
98%
17 days
Waveform 7
1,000,000
98%
17 days
Waveform 8
940,000
98%
17 days
Waveform 9
700,000
98%
17 days
Waveform 10
1,000,000
98%
17 days
Control 1
500,000
98%
17 days
Control 2
400,000
98%
17 days
Control 3
300000
98%
17 days
Control 4
500,000
98%
17 days
Control 5
400,000
98%
17 days
*Cells were in direct contact with the electrode.
TABLE 2
*Cell Count and Viability at Harvest (day 18)
NHNP-POOL
CELL COUNT
VIABILITY
HARVEST
Waveform 1
1,000,000
100%
18 days
Waveform 5
1,100,000
100%
18 days
Control 1
800,000
100%
18 days
Control 5
800,000
100%
18 days
*Cells were not in direct contact with the electrode.
TABLE 3
*Cell Count at Various Times after Removal of Waveform
CELLS
COUNT
HOURS OFF ELECTRODE
Waveform 11
520,000
Counted and re-seeded at 96,000/plate
Control 6
112,000
Counted and re-seeded at 96,000/plate
Waveform 11
274,000
48 hours off electrode
Control 6
48,000
48 hours off electrode
Waveform 12
576,000
Counted and re-seeded at 96,000/plate
Control 7
96,000
Counted and re-seeded at 96,000/plate
Waveform 12
228,000
72 hours off electrode
Control 7
120,000
72 hours off electrode
*Cells were in direct contact with the electrode.
TABLE 4
*Cell Count and Viability at Various Times after Harvest
TIME AFTER
HARVEST
NHNP-POOL
CELL COUNT
VIABILITY
(Hours)
Waveform 1
56,000
85%
24
Waveform 5
40,000
85%
24
Control 1
36,000
65%
24
Control 5
28,000
65%
24
Waveform 1
188,000
98%
48
Waveform 5
212,000
98%
48
Control 1
74,000
87%
48
Control 5
162,000
90%
48
Waveform 1
3,400,000
100%
120
Waveform 5
3,400,000
100%
120
Control 1
900,000
99%
120
Control 5
900,000
99%
120
Waveform 1
4,000,000
100%
168
Waveform 5
3,800,000
100%
168
Control 1
980,000
97%
168
Control 5
900,000
95%
168
*Cells were not in direct contact with the electrode.
EXAMPLE 6
Waveform Gene Array Display (GAD) Results
Normal Human Neural Progenitor cells or human adult astrocytes were exposed to waveform and non-waveform growth conditions for 17 days. Upon completion of the exposure period cells were harvested via trypsinization and poly-RNA was prepared from the respective groups of cells. RNA samples were quick frozen and shipped to Synteni Corporation for GAD analysis. Below are the results of a survey of the response of over 10,000 human genes. The results were divided into two categories (Table 5 and Table 6). Those genes down regulated or suppressed by the waveform and those up regulated or enhanced in activity by the waveform.
An analysis of the data indicates a significant down regulation of maturation and regulatory genes. These maturation and regulatory genes are normally associated with the differentiated or non-growth profile of normal cells. However, there is a significant up regulation of some 150 genes which are mainly associated with growth and cellular proliferation. Neither two nor three dimensional growth of neural cells has been achieved prior to this event with the positive outcome of enhanced growth and apparent gene regulatory control.
TABLE 5
Down Regulated Genes in Descending Order (Highest to lowest)
1 . Homo sapiens (clone Zap2) mRNA fragment {Incyte PD:1661837}
2. CDC28 protein kinase 2{Incyte PD:1384823}
3. Synteni: YCFR 22 {YC 22.2000.W}
4. ESTs, Moderately similar to cell growth regulating nucleolar protein LYAR [ M.musculus ] {Incyte PD:2233551}
5. KERATIN, TYPE II CYTOSKELETAL 7 {Incyte PD:1649959}
6. MITOTTC KINESIN-LIKE PROTEIN-1 {Incyte PD:2640427}
7. EST {Incyte PD:674714}
8. Synteni: YCFR 22 {YC 22.2000.X}
9. Synteni: YCFR 26 {YC 26.0062.N}
10. Synteni: YCFR 22 {YC 22.2000.Z}
11. Transcription factor 6-like 1 (mitochondrial transcription factor 1-like) {Incyte PD:3371995}
12. Interferon-inducible 56-KDa protein {Incyte PD:1215596}
13. EST {Incyte PD:1794375}
14 . Homo sapiens mitotic feedback control protein Madp2 homolog mRNA, complete cds {Incyte PD:2414624}
15. EST {Incyte PD:151026}
16 . Homo sapiens Pig3 (PIG3) mRNA, complete cds {Incyte PD:2395269}
17. General transcription factor IIIA {Incyte PD:1527070}
18. Cellular retinoic acid-binding protein [human, skin, mRNA, 735 nt] {Incyte PD:585432}
19. EST {Incyte PD:1755159}
20 . Homo sapiens mRNA for KIAA0285 gene, complete cds {Incyte PD:1738053}
21. ESTs, Weakly similar to F25H5.h [ C.elegans ] {Incyte PD:1923567}
22 . Homo sapiens mRNA expressed in osteoblast, complete cds {Incyte PD:2537863}
23. EST {Incyte PD:3204745}
24 . Homo sapiens mRNA for serine/threonine protein kinase SAK {Incyte PD:2732630}
25 . Homo sapiens serum-inducible kinase mRNA, complete cds {Incyte PD:1255087}
26. Carbonic anhydrase II {Incyte PD:2474163}
27. EST {Incyte PD:660376}
28. GRANCALCIN {Incyte PD:1671852}
29. N-CHIMAERIN {Incyte PD:1852659}
30 . Homo sapiens Pig10 (PIG10) M3RNA, complete cds {Incyte PD:1731061}
31. Adenylosuccinate lyase {Incyte PD:1653326}
32. EST {Incyte PD:1798393}
33 . Homo sapiens HP protein (HP) mRNA, complete cds {Incyte PD:30841223}
34. ESTs, Moderately similar to T10C6 [C.elegans ] {Incyte PD:1923186}
35. Chromosome condensation 1 {Incyte PD:3180854}
36. Calmodulin 1 (phosphorylase kinase, delta) {Incyte PD:2803306}
37. Centromere protein A (17kD) {Incyte PD:2444942}
38. V-jun avian sarcoma virus 17 oncogene homolog {Incyte PD:1920177}
39. Human glutathione-S-transferase homolog mRNA, complete cds {Incyte PD:1862232}
40 . Homo sapiens gene for protein involved in sexual development, complete cds {Incyte PD:3033934}
41. EST {Incyte PD:2630992}
42. Human low-Mr GTP-binding protein (RAB32) mRNA, partial cds {Incyte PD:1662688}
43. Annexin III (lipocortin Ill) {Incyte PD:1920650}
44. Hydroxymethylbilane synthase {Incyte PD:1509204}
45. Synteni: HK 4 {HK 4.2000.Y}
46. Ribosomal protein L7a {Incyte PD:2579602}
47. Human mRNA for myosin regulatory light chain {Incyte PD:78783}
48. Ferredoxin reductase {Incyte PD:1819763}
49. Human copper transport protein HAH1 (HAH1) mRNA, complete cds {Incyte PD:2313349}
50. Human G protein gamma-11 subunit mRNA, complete cds {Incyte PD:1988432}
51. Synteni: HK 4 {HK 4.2000.W}
52. Human XIST, coding sequence a mRNA (locus DXS399E) {Incyte PD:1514318}
53. Ribosomal protein, large, P0 {Incyte PD:3511355}
54 . Homo sapiens clone 23714 mRNA sequence {Incyte PD:1728368}
55. Human mRNA for Apo1 13 Human (MER5(Aop1-Mouse)like protein), complete cds {Incyte PD:2527879}
56. Synteni: HK 4 {HK 4.2000.Z}
57. Proteasome (prosome, macropain) subunit, beta type, 5 {Incyte PD:2503119}
58. Human PINCH protein mRNA, complete cds {Incyte PD:126888}
59 . Homo sapiens peroxisome assembly protein PEX10 mRNA, complete cds {Incyte PD:998279}
60 . Homo sapiens short chain L-3-hydroxyacyl-CoA dehydrogenase (SCHAD) mRNA, complete cds {Incyte PD:1638850}
61. Neuroblastoma RAS viral (v-ras) oncogene homolog {Incyte PD:2816984}
62 . H.sapiens mRNA for b4 integrin interactor {Incyte PD:1932850}
63. Human forkhead protein FREAC-1 mRNA, complete cds {Incyte PD:1449920}
64. Human mRNA for protein D123, complete cds {Incyte PD:1920522}
65 . H.sapiens mRNA for A-kinase anchoring protein AKAP95 {Incyte PD:1628787}
66. Carbonyl reductase {Incyte PD:1633249}
67. EST {Incyte PD:2060973}
68. ESTs, Highly similar to GUANINE NUCLEOTIDE-BINDING PROTEIN G(I)/G(S)/G(O) GAMMA-7 SUBUNIT [ Rattus norvegicus ] {Incyte PD:1640161}
69 . Homo sapiens Na+/Ca+exchanger mRNA sequence {Incyte PD:2880435}
70. STRESS-ACTIVATED PROTEIN KINASE JNK1 {Incyte PD:3331719}
71 . Homo sapiens leupaxin mRNA, complete cds {Incyte PD:1595756}
72. CLEAVAGE SIGNAL-1 PROTEIN {Incyte PD:2054053}
73. EST {Incyte PD:1798965}
74. Human DNA from overlapping chromosome 19 cosmids R31396, F2545 1, and R31076 containing COX6B and UPKA, genomic sequence {Incyte PD:1320685}
75. INTERFERON-INDUCED 17 KD PROTEIN {Incyte PD:2862971}
76. Human homolog of yeast IPP isomerase {Incyte PD:1526240}
77. Translation elongation factor 1 gamma {Incyte PD:3138196}
78. Tropomyosin alpha chain (skeletal muscle) {Incyte PD:1572555}
79. Aplysia ras-related homolog 9 {Incyte PD:2733928}
80. ATP SYNTHASE ALPHA CHAIN, MITOCHONDRIAL PRECURSOR {Incyte PD:3206210}
81 . Homo sapiens androgen receptor associated protein 24 (ARA24) mRNA, complete cds {Incyte PD:552654}
82. Glucagon {Incyte PD:1333075}
83. Human enhancer of rudimentary homolog mRNA, complete cds {Incyte PD:1704472}
84. TRANSCRIPTIONAL ENHANCER FACTOR TEF-1 {Incyte PD:2957175}
85. Ubiquitin-like protein {Incyte PD:1754454}
86. Human RGP4 mRNA, complete cds {Incyte PD:617517}
87. Cellular retinol-binding protein {Incyte PD:1612969}
88. Ornithine decarboxylase 1 {Incyte PD:1930235}
89. EST {Incyte PD:3605632}
90. EST {Incyte PD:2057260}
91. ESTs, Weakly similar to CAMP-DEPENDENT PROTEIN KINASE TYPE 2 [Saccharomyces cerevisiae ] {Incyte PD:2055611}
92. Human p37NB mRNA, complete cds {Incyte PD:1407110}
93. Human mRNA for suppressor for yeast mutant, complete cds {Incyte PD:2888814}
94. EST {Incyte PD:3142705}
95. ESTs, Weakly similar to K01H12.1 [C.elegans ] {Incyte PD:56197}
96. Cell division cycle 2, G1 to S and G2 to M {Incyte PD:1525795}
97. EST {Incyte PD:1794175}
98. EST {Incyte PD:1489557}
99. ESTs, Weakly similar to PROTEIN PHOSPHATASE PP2A, 72 KD REGULATORY SUBUNIT [ H.sapiens ] {Incyte PD:2379045}
100. CAMP-DEPENDENT PROTEIN KINASE TYPE II-ALPHA REGULATORY CHAIN {Incyte PD:1649731}
101. ESTs, Weakly similar to transcription factor [ H.sapiens ] {Incyte PD:1637517}
102. ATP synthase, H+transporting, mitochondrial F1 complex, O subunit (oligomycin sensitivity conferring protein) {Incyte PD:2193246}
103. RAS-LIKE PROTEIN TC21{Incyte PD:2505425}
104. Small nuclear ribonucleoprotein polypeptides B and B1 {Incyte PD:2071473}
105. EST {Incyte PD:1922084}
106. Proliferating cell nuclear antigen {Incyte PD:2781405}
107. ESTs, Highly similar to HIGH MOBILITY GROUP-LIKE NUCLEAR PROTEIN 2 [Saccharomyces cerevisiae ] {Incyte PD:2669174}
108. EST {Incyte PD:1844150}
109. Human mRNA for proteasome subunit HsC10-II, complete cds {Incyte PD:1737833}
110 . Homo sapiens mRNA for ST1 C2, complete cds {Incyte PD:3993007}
111. Human dual specificity phosphatase tyrosine/serine mRNA, complete cds {Incyte PD:1514573}
112. Human stimulator of TAR RNA binding (SRB) mRNA, complete cds {Incyte PD:2057162}
113. EST {Incyte PD:2507206}
114 . H.sapiens mRNA for Ndr protein kinase {Incyte PD:3318571}
115. ESTs, Weakly similar to Grb2-related adaptor protein [H.sapiens] {Incyte PD:1857259}
116. ESTs, Highly similar to Tbc1 [M.musculus ] {Incyte PD:1889147}
117. GTPase-activating protein ras p21 (RASA) {Incyte PD:147344}
118. Human mRNA for KIAA0123 gene, partial cds {Incyte PD:1752436}
119. Synteni: YCFR 22 {YC 22.2000.Y}
120. Human non-histone chromosomal protein (NHC) mRNA, complete cds {Incyte PD:1748670}
121. Thioredoxin {Incyte PD:2606240}
122. FATTY ACID-BINDING PROTEIN, EPIDERMAL {Incyte PD:2537805}
123. Proteasome component C2 {Incyte PD:2195309}
124 . Homo sapiens heat shock protein hsp40 homolog mRNA, complete cds {Incyte PD:2844989}
125. Human amyloid precursor protein-binding protein 1 mRNA, complete cds {Incyte PD:1663083}
126 . Homo sapiens DNA binding protein homolog (DRIL1) mRNA, complete cds {Incyte PD:2538333}
127. Human Has2 mRNA, complete cds {Incyte PD:3602403}
128. EST {Incyte PD:1749678}
129 . Homo sapiens golgi SNARE (GS27) mRNA, complete cds {Incyte PD:3279439}
130. ESTs, Weakly similar to UBIQUITIN-ACTIVATING ENZYME E1 HOMOLOG [ H.sapiens ] {Incyte PD:1710472}
131. Synteni: YCFR 22 {YC 22.2000N}
132. Voltage-dependent anion channel 2 {Incyte PD:2189062}
133. Human rap2 mRNA for ras-related protein {Incyte PD:3334979}
134. Acid phosphatase 1, soluble {Incyte PD:620871}
135. Human clone 23840 mRNA, partial cds {Incyte PD:1830083}
136. Human mRNA for KIAA0008 gene, complete cds {Incyte PD:1970111}
137 . H.sapiens mRNA for protein-tyrosine-phosphatase (tissue type: foreskin) {Incyte PD:444957}
138. Human B-cell receptor associated protein (hBAP) mRNA, partial cds {Incyte PD:2545562}
139. ESTs, Highly similar to ring finger protein [H.sapiens] {Incyte PD:2860918}
140 . H.sapiens mRNA for CLPP {Incyte PD:2675481}
141. APOPTOSIS REGULATOR BCL-X {Incyte PD:1855683}
142. PROTEASOME COMPONENT C13 PRECURSOR {Incyte PD:2668334}
143. Sorting nexin 1 {Incyte PD:1508407}
144. Human voltage dependent anion channel form 3 mRNA, complete cds {Incyte PD:2051154}
145 . H.sapiens mRNA for translin {Incyte PD:986855}
146. Human DEAD-box protein p72 (P72) mRNA, complete cds {Incyte PD:1750553}
147. Ras homolog gene family, member G (rho G) {Incyte PD:1342744}
148. EST {Incyte PD:1377794}
149. Human FEZ2 mRNA, partial cds {Incyte PD:2623268}
150. Human homolog of Drosophila discs large protein, isoform 2 (hdlg-2) mRNA, complete cds {Incyte PD:2203554}
151. ALCOHOL DEHYDROGENASE {Incyte PD:1634342}
152. 3-hydroxymethyl-3-methylglutaryl-Coenzyme A lyase (hydroxymethylglutaricaciduria) {Incyte PD:1695917}
153. ENOYL-COA HYDRATASE, MITOCHONDRIAL PRECURSOR {Incyte PD:2235870}
154. Proteasome (prosome, macropain) subunit, beta type, 6 {Incyte PD:2989852}
155. INTERFERON GAMMA UP-REGULATED I-5111 PROTEIN PRECURSOR {Incyte PD:2211625}
156. Epimorphin {Incyte PD:3438987}
157 . H.sapiens RY-1 mRNA for putative nucleic acid binding protein {Incyte PD:1805712}
158. EST {Incyte PD:1905120}
159. KD HOUSEKEEPING PROTEIN {Incyte PD:1819287}
160. Cytochrome c oxidase subunit VIIb {Incyte PD:2060789}
161. EST {Incyte PD:661516}
162 . Homo sapiens nuclear VCP-like protein NVLp.2 (NVL.2) mRNA, complete cds {Incyte PD:1445507}
163. EST {Incyte PD:1251588}
164. EST {Incyte PD:1665871}
165 . Homo sapiens inositol polyphosphate 4-phosphatase type 11-alpha mRNA, complete cds {Incyte PD:3032739}
166 . Homo sapiens arsenite translocating ATPase (ASNA1) mRNA, complete cds {Incyte PD:1666094}
167. Human SnRNP core protein Sm D3 mRNA, complete cds {Incyte PD:1624865}
168 . Homo sapiens clone 23777 putative taansmembrane GTPase mRNA, partial cds {Incyte PD:2554541}
169 . Homo sapiens regulator of G protein signaling RGS12 (RGS) mRNA, complete cds {Incyte PD:3618382}
170. Human Ki nuclear autoantigen mRNA, complete cds {Incyte PD:1308112}
171 . Homo sapiens peroxisomal phytanoyl-CoA alpha-hydroxylase (PAHX) mRNA, complete cds {Incyte PD:4073867}
172. PLACENTAL CALCIUM-BINDING PROTEIN {Incyte PD:1222317}
173. PRE-MRNA SPLICING FACTOR SF2, P32 SUBUNIT PRECURSOR {Incyte PD:1552335}
174. Human clone C4E 1.63 (CAC)n/(GTG)n repeat-containing mRNA {Incyte PD:1928789}
175. Human glioma pathogenesis-related protein (GliPR) mRNA, complete cds {Incyte PD:477045}
176. Homeo box A9 {Incyte PD:459651}
TABLE 6
Waveform Up Regulated Genes in Ascending Order (Lowest to Highest)
1. NEUROMEDIN B PRECURSOR {Incyte PD:2754315}
2. Synteni: YCFR 21 {YC 21.0031.N}
3. ATRIAL NATRTC PEPTIDE CLEARANCE RECEPTOR PRECURSOR {Incyte PD:1353606}
4. Synteni: YCFR 85 {YC 85.2000.Y}
5 . Homo sapiens CHD3mRNA, complete cds {Incyte PD:1965248}
6. EST {Incyte PD:565872}
7. Synteni: YCFR 46 Cy3 {YC 46.2000. Z}
8. ESTs, Weakly similar to metaxin [ H.sapiens ] {Incyte PD:1754461}
9. Plasminogen {Incyte PD:2515873}
10. Human mRNA for CC chemokine LARC precursor, complete cds {Incyte PD:2220923}
11. Synteni: YCFR 21 {YC 21.0062.N)
12 . Homo sapiens Amplified in Breast Cancer (AIB1) mRNA, complete cds Incyte PD:2634478}
13 . Homo sapiens clone 24640 mRNA sequence {Incyte PD:1560143}
14. Synteni: YCFR 21 {YC 21.2000.N}
15. EST {Incyte PD:143912}
16. Human transcription factor SIM2long form mRNA, complete cds {Incyte PD:996104}
17. EST {Incyte PD:2841478}
18. PUTATIVE DNA BINDING PROTEIN A20 {Incyte PD:1878791}
19. Protein tyrosine phosphatase, receptor type, mu polypeptide {Incyte PD:987736}
20. Human clone A9A2BRB5(CAC)n/(GTG)n repeat-containing mRNA {Incyte PD:1987975}
21. Endothelin converting enzyme 1 {Incyte PD:1963819}
22. BB1 {Incyte PD:1966148}
23. Pleiotrophin (heparin binding growth factor 8, neurite growth-promoting factor 1) {Incyte PD:2989411}
24. Argininosuccinate synthetase {Incyte PD:1981145}
25. Human breast epithelial antigen BA46mRNA, complete cds {Incyte PD:1319020}
26. Human clone 46690 brain expressed mRNA from chromosome X {Incyte PD:1669780}
27. Human plectin (PLEC1) mRNA, complete cds {Incyte PD:1907232}
28 . Homo sapiens mRNA for calmegin, complete cds {Incyte PD:2498216}
29. EST {Incyte PD:769182}
30. Amyloid beta (A4) precursor-like protein 2 {Incyte PD:3876715}
31. Polymerase (RNA) II (DNA directed) polypeptide A (220 kD) {Incyte PD:1382059}
32. GLUCOSE TRANSPORTER TYPE 3, BRAIN {Incyte PD:2745082}
33 . Homo sapiens sarco-/endoplasmic reticulum Ca-ATPase 3 (ATP2A3) mRNA, alternatively spliced, partial cds {Incyte PD:688411}
34. Human c-jun proto oncogene (JUN), complete cds, clone hCJ-1 {Incyte PD:1969563}
35. Microtubule-associated protein 1A {Incyte PD:702684}
36. Clusterin (complement lysis inhibitor, testosterone-repressed prostate message 2; apolipoprotein J) {Incyte PD:2966620}
37. NADH-CYTOCHROME B5 REDUCTASE {Incyte PD:1901142}
38. Protein-tyrosine kinase 7 {Incyte PD:996229}
39. Alpha-1 type XVI collagen {Incyte PD:1963529}
40. EST {Incyte PD:2839121}
41 . Homo sapiens mRNA for DEC 1, complete cds {Incyte PD:1732479}
42. Human endogenous retroviral protease mRNA, complete cds {Incyte PD:1347636}
43. ATPase, Na+/K+transporting, alpha 1polypeptide {Incyte PD:1730609}
44. Laminin,alpha 4 {Incyte PD:1851696}
45. Hexabrachion (tenascin C, cytotactin) {Incyte PD:1453450}
46. Human mRNA for KIAA0325 gene, partial cds {Incyte PD:1995315}
47. Integrin beta-5 subunit {Incyte PD:418731}
48. Microfibrillar-associated protein 4 {Incyte PD:1659231}
49. Fibulin 1 {Incyte PD:1320658}
50. Protein serine/threonine kinase stk2 {Incyte PD:1518981}
51. ESTs, Weakly similar to HYPOTHETICAL 16.1 KD PROTEIN IN SEC 17-QCR1 INTERGENIC REGION [ Saccharomyces cerevisiae ] {Incyte PD:1923722}
52 . Homo sapiens carbonic anhydrase precursor (CA 12) mRNA, complete cds {Incyte PD:3766382}
53 . H.sapiens mRNA for SIX1 protein {Incyte PD:3208486}
54. Plasminogen activator inhibitor, type I {Incyte PD:1445767}
55. Human mRNA for SHPS-1, complete cds {Incyte PD:2180684}
56. Collagen, type V, alpha 1 {Incyte PD:1672442}
57 . Homo sapiens monocarboxylate transporter (MCT3) mRNA, complete cds {Incyte PD:1343253}
58. Human follistatin gene {Incyte PD:1577614}
59. Human putative RNA binding protein (RBP56) mRNA, complete cds {Incyte PD:1907369}
60 . Homo sapiens mRNA for PRP8 protein, complete cds {Incyte PD:3616229}
61 . Homo sapiens CAGH13 mRNA, complete cds {Incyte PD:1432042}
62. EST {Incyte PD:2953888}
63. Intercellular adhesion molecule 1 (CD54), human rhinovirus receptor {Incyte PD:1556061}
64. Human p120E4F transcription factor mRNA, complete cds {Incyte PD:1940164}
65. Collagen, type VI, alpha 1 {Incyte PD:2672056}
66. Human mRNA for pM5 protein {Incyte PD:1578951}
67. ALZHEIMER'S DISEASE AMYLOID A4 PROTEIN PRECURSOR {Incyte PD:126370}
68. Human mRNA for KIAA0062 gene, partial cds {Incyte PD:3138128}
69. Human clone HSH1 HMG CoA synthase mRNA, partial cds {Incyte PD:1807407}
70. Filamin 1 (actin-binding protein-280) {Incyte PD:1708528}
71. Synteni: YCFR 85 {YC 85.2000.X}
72. Synteni: YCFR 46 Cy3 {YC 46.2000.W}
73. Homologue of mouse tumor rejection antigen gp96 {Incyte PD:2679349}
74. Tissue inhibitor of metalloproteinase 3 (Sorsby fundus dystrophy, pseudoinflammatory) {Incyte PD:418041}
75. Human XMP mRNA, complete cds {Incyte PD:1887661}
76. Cytochrome P450, subfamily XIA (cholesterol side chain cleavage) {Incyte PD:2368282}
77. Granulin {Incyte PD:812141}
78. Human extracellular matrix protein 1 (ECM1) mRNA, complete cds {Incyte PD:1965806}
79. 78 KD GLUCOSE REGULATED PROTEIN PRECURSOR {Incyte PD:2884613}
80. Synteni: YCFR 21 {YC 21.2000.X}
81 . Homo sapiens mRNA for serin protease with IGF-binding motif, complete cds {Incyte PD:1958902}
82. Inhibitor of DNA binding 1, dominant negative helix-loop-helix protein {Incyte PD:1687060}
83. Solute carrier family 6 (neurotransmitter transporter, taurine), member 6 {Incyte PD:1516886}
84. Hormone receptor (growth factor-inducible nuclear protein N10) {Incyte PD:1958560}
85. Fibulin 2 {Incyte PD:1901095}
86. Kinase insert domain receptor (a type III receptor tyrosine kinase) {Incyte PD:2220338}
87. Synteni: YCFR 45 {YC 45.2000.X}
88. Syndecan 4 (amphiglycan, ryudocan) {Incyte PD:3214670}
89. Synteni: YCFR 21 {YC 21.0500. N}
90. Human pre-B cell enhancing factor (PBEF) mRNA, complete cds {Incyte PD:1641590}
91. Cytochrome P450, subfamily IIC (mephenytoin 4-hydroxylase) {Incyte PD:168865}
92. Latent transforming growth factor beta binding protein 1{Incyte PD:1313183}
93. Lysyl hydroxylase {Incyte PD:1759127}
94. Human mRNA for KIAA0230 gene, partial cds {Incyte PD:1449824}
95. Human mRNA for dihydropyrimidinase related protein-2, complete cds {Incyte PD:2784546}
96 . H.sapiens garp gene mRNA, complete CDS {Incyte PD:3572014}
97. EST {Incyte PD:724880}
98. ESTs, Weakly similar to TRANSMEMBRANE PROTEIN SEX PRECURSOR [ H.sapiens ] {Incyte PD:1511346}
99. Human contactin associated protein (Caspr) mRNA, complete cds {Incyte PD:2309047}
100. Human cysteine-rich fibroblast growth factor receptor (CFR-1) mRNA, complete cds {Incyte PD:2204871}
101. EST {Incyte PD:2580841}
102. Collagen, type V, alpha {Incyte PD:1887959}
103 . H.sapiens RNA for type VI collagen alpha3 chain {Incyte PD:1314882}
104. Protein kinase C substrate 80K-H {Incyte PD:1723971}
105. Fibrillin 1 (Marfan syndrome) {Incyte PD:1448051}
106. Collagen, type XI, alpha 1 {Incyte PD:3598222}
107 . H.sapiens mRNA for extracellular matrix protein collagen type )aV, C-terminus {Incyte PD:2208990}
108. Collagen, type II, alpha 1 (primary osteoarthritis, spondyloepiphyseal dysplasia, congenital) {Incyte PD:2518178}
109. ESTs, Weakly similar to unknown [ S.cerevisiae ] {Incyte PD:2171401}
110. EST {Incyte PD:1923572}
111. Human insulin-like growth factor binding protein 5 (IGFBP5) mRNA {Incyte PD:1686585}
112. Human mRNA for KIAA0242 gene, partial cds {Incyte PD:1940994}
113. Complement component 1, s subcomponent {Incyte PD:1904751}
114. Human chromosome 17 unknown product mRNA, complete cds {Incyte PD:2849603}
115 . Homo sapiens lysosomal pepstatin insensitive protease (CLN2) mRNA, complete cds {Incyte PD:3500996}
116. Collagen, type IV, alpha 2 {Incyte PD:1906574}
117. ESTs, Moderately similar to ZINC FINGER PROTEIN HF.12 [Homo sapiens ] {Incyte PD:3729155}
118 . Homo sapiens stanniocalcin precursor (STC) mRNA, complete cds {Incyte PD:2222921}
119. P55-C-FOS PROTO-ONCOGENE PROTEIN {Incyte PD:341491}
120. EST {Incyte PD:2424631}
121. EST {Incyte PD:1940710}
122. Thrombospondin 1 {Incyte PD:2055534}
123. Complement component C 1r {Incyte PD:1664320}
124. REGULATOR OF G-PROTEIN SIGNALLING 2{Incyte PD:1218114}
125. INTEGRAL MEMBRANE PROTEIN E16 {Incyte PD:1911012}
126. Collagen, type I, alpha 1 {Incyte PD:782235}
127 . H.sapiens mRNA for adipophilin {Incyte PD:1985104}
128. EST {Incyte PD:1979450}
129. EST {Incyte PD:690994}
130. Cathepsin D (lysosomal aspartyl protease) {Incyte PD:3940755}
131. Matrix metalloproteinase 2 (gelatinase A, 72 kD gelatinase, 72 kD type IV collagenase) {Incyte PD:1558081}
132. Cyclin D2 {Incyte PD:1618422}
133. EST {Incyte PD:2636514}
134. COMPLEMENT C3 PRECURSOR {Incyte PD:1513989}
135 . Homo sapiens secreted frizzled related protein mRNA, complete cds {Incyte PD:428236}
136. INSULIN-LIKE GROWTH FACTOR BINDING PROTEIN 3 PRECURSOR {Incyte PD:1447903}
137. Fibronectin 1 {Incyte PD:3553729}
138. Early growth response protein 1 {Incyte PD:1705208}
139. Human autoantigen DFS70 mRNA, partial cds {Incyte PD:42920}
140. Prostaglandin-endoperoxide synffiase 2 (prostaglandin G/H synthase and cyclooxygenase) {Incyte PD:3139163}
141. Synteni: YCFR 43 {YC 43.2000.W}
142. Synteni: YCFR 43 {YC 43.2000.Z}
143. Synteni: YCFR 23 {YC 23.0062.N}
144. Synteni: YCFR 43 {YC 43.2000.Y}
145 . Homo sapiens phosphomevalonate kinase mRNA, complete cds {Incyte PD:1497123}
146. Synteni: YCFR 43 {YC 43.2000.X}
147. Synteni: YCFR 23 {YC 23.0031.N}
148. CARTILAGE GLYCOPROTEIN-39 PRECURSOR {Incyte PD:157510}
149. Synteni: YCFR 23 {YC 23.0125.N}
150. Synteni: YCFR 23 {YC 23.0250.N}
151. Synteni: YCFR 23 {YC 23.4000.N}
152. Human germline oligomeric matrix protein (COMP) mRNA, complete cds {Incyte PD:2636634}
EXAMPLE 7
Prototype of the System
FIGS. 10 and 11 are partially diagrammatic representations of one embodiment of the system 1 . Spherical disks 2 of biocompatable material are arranged along the horizontal spin filter or horizontal oxygenator of a standard rotating wall perfused vessel or rotating wall batch-fed vessel 5 .
The electrically conductive, bioattractive strips 6 are each suitably embedded in or affixed to each of the disks such that each disk has a positive and negative pole 12 , associated with positive and negative terminals 12 connected to respective endportions of the strips, as shown in FIG. 11 A. As will be more fully described, in one preferred embodiment in which an alternating current is applied to the strips, the polarity of the strips changes cyclically in correspondence with the change in polarity of the applied current. Each biocompatable disk is preferably two-sided, allowing growth of tissue on both the left and right portions of the spherical disk. Sterilization of the reactor core is effected by one of multiple sterilization procedure, either ethylene oxide sterilization, autoclave sterilization if the polymer perrnits, or in the case of the batch-fed vessel, sterilization with hydrogen peroxide. After sterilization and sufficient detoxification procedures, cellular material is seeded into the reactor at a level to be determined according to the cell line of interest.
A source of time varying current 10 , suitably a laboratory current source with adjustable wave-forn output connected to a remote power source, not shown, is operable to provide a time varying current, suitably of a value of about 1 mA to about 1,000 mA, in the present embodiment. The time varying current is suitably an alternating current, as indicated above, although in other embodiments it is a pulsating DC current. The current is conducted from the source 10 along first and second conductors 13 A and 13 B to slip rings 4 . The slip rings are non-rotatable relative to the vessel 5 , and therefore rotate with the vessel during operation. Current received through conductors 13 A and 13 B is conducted through the associated slip rings to first and second sets of conductors, represented by first and second conductors 14 A and 14 B, which are preferably insulated with an insulative material, not shown, compatible with the fluids and products within the bioreactor chamber. Each conductor is mechanically connected to a respective peripheral portion of each of the respective discs, and electrically connected with an end portion of one of the conductive strips 6 (FIGS. 1 A and 1 B). As viewed in FIG. 10, conductor 14 A and the associated slip ring are indicated to be of positive (+) polarity, and conductor 14 B and its associated slip ring are indicated to be of relatively negative (−) polarity. As suggested above, upon the current changing in polarity, conductor 14 A will momentarily have a negative potential relative to conductor 14 B, thereby permitting a time varying current, which in this embodiment is an alternating current, to flow through conductor 6 which. In other embodiments, the time-varying current may be in the form of a pulsating DC current, suitably a square wave or other waveform, rather than an alternating current, in which case the conductors 14 A and 14 B and their associated slip rings remain of the same polarity but of differing potentials.
After inoculation, the rotating wall vessel 5 is rotated at an appropriate speed and single cellular material begins to attach onto the surface of the biocompatable material 6. After initial growth of one 24- or 48-hour period, electrical stimulation, i.e., potentiation, begins via continuous low-level or pulsatile electrical flow through each disk in series.
Discussion
Use of the methods of the present invention to control the proliferative rate of normal human adult astrocytes and normal human neural progenitor cells (NHNP) has been demonstrated. The procedure is applicable to, but not limited to, the control of normal human neural cells in both two-dimensional and threeimensional culture. As presented in the molecular genetic data shown in Table 5 and Table 6, many of the genetic responses in both up regulated and down regulated genes are maturation and growth regulatory in nature. An inspection reveals these genes are also primarily involved in the eipbryogenic process. Therefore it is reasonable to conclude that control over the embryogenic development process can be achieved via the presently demonstrated methodology.
As shown in Table 6, specific genes such as human germline oligomeric matrix protein, prostaglandin endoperoxide synthase 2 , early growth response protein 1 , and insulin like growth factor binding protein 3 precursor are highly up regulated, while Keratin Type II cytoskelatal 7 , mytotic kinesin like protein 1 , transcription factor 6 like 1 , mytotic feedback control protein, and cellular retinoic acid binding protein are down regulated (Table 5). Each of these two sets or classes of genes are only examples from the sum of approximately 320 genes changes expressed as a consequence of exposure to electrical potentiation.
As is clearly demonstrated in the human body, the bioelectric, biochemical process of electrical nerve stimulation is a documented reality. The present invention demonstrates that the same phenomena can be potentiated in a synthetic atmosphere, i.e., in rotating wall cell culture vessels. As may be understood from the forgoing discussion, this electrical potentiation can be used for a number of purposes.
The following references were cited herein.
1. Schwarz et al., U.S. Pat. No. 4,988,623, (1991).
2. Schwarz et al., U.S. Pat. No. 5,026,650, (1991).
3. Goodwin, et al., In Vitro Cell Dev. Biol. , 28A:47-60(1992).
4. Goodwin, et al., Proc. Soc. Exp. Biol. Med. , 202:181-192 (1993).
5. Goodwin, et al., J. Cell Biochem. , 51:301-311 (1993).
6. Goodwin, et al., In Vitro Cell Dev. Biol. Anim. , 33:366-374 (1997).
7. Fukuda et al., U.S. Pat. No. 5,328,843
8. Aebischer, U.S. Pat. No. 5,030,225
Any patents or publications mentioned in this specification are indicative of the levels of those skilled in the art to which the invention pertains. These patents and publications are herein incorporated by reference to the same extent as if each individual publication was specifically and individually indicated to be incorporated by reference.
One skilled in the art will readily appreciate that the present invention is well adapted to carry out the objects and obtain the ends and advantages mentioned, as well as those inherent therein. The present examples along with the methods, procedures, treatments, molecules, and specific compounds described herein are presently representative of preferred embodiments, are exemplary, and are not intended as limitations on the scope of the invention. Changes therein and other uses will occur to those skilled in the art which are encompassed within the spirit of the invention as defined by the scope of the claims.
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The present invention provides systems for growing two or three dimensional mammalian cells within a culture medium facilitated by an electromagnetic field, and preferably, a time varying electromagnetic field. The cells and culture medium are contained within a fixed or rotating culture vessel, and the electromagnetic field is emitted from at least one electrode. In one embodiment, the electrode is spaced from the vessel. The invention further provides methods to promote neural tissue regeneration by means of culturing the neural cells in the claimed system. In one embodiment, neuronal cells are grown within longitudinally extending tissue strands extending axially along and within electrodes comprising electrically conductive channels or guides through which a time varying electrical current is conducted, the conductive channels being positioned within a culture medium.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
A bayonet-type bulb mounting assembly of the type commonly employed on large vehicles, such as school buses, in which conventional vehicular lamp housings require separately wired sockets for securing a bayonet-type bulb, and the bulb contacts are subject to galvanic and oxidation corrosion from the inhospitable environment of vehicle operation. The present invention takes advantage of previously troublesome realities of vehicle operation, by providing a lamp housing that avoids corrosion build-up through a wiping action in response to vehicle vibrations.
2. Description of the Prior Art
Various forms of bayonet-type lamp sockets are known in the prior art, and various structures to avoid corrosion of bulb contacts in vehicular use have been proposed. Exemplary of the prior art are the following U.S. Pat. Nos. MOORE 3,858,038; HESS 3,819,926; FREEMAN 3,813,535; RILEY 3,780,282; NEWMAN 3,748,462; PLOEGER 3,739,168; DUPREE 3,602,708; ALTISSIMO 3,489,891; QUELLAND 3,300,636; CHENG 3,246,136; SCHUMACHER 2,980,791; BALDWIN 2,853,595; MEARS 2,786,129; BENANDER 2,292,038; DEL CAMP 2,225,584; FRASER 2,069,238; WOOD 1,977,105.
The patent to Moore illustrates a form of submersible vehicle lamp assembly with a conventional bayonet connector requiring separate wire leads to an ultimate electrical connection. As such, Moore represents the typical bulb mounting which is used in the art.
Hess illustrates a similar employment of a conventional bayonet mount within a vehicle lamp assembly.
The patent to Freeman illustrates another form of clip to hold the base of a bayonet-type bulb in a surrounding relation against vibratory movement.
The patent to Riley shows a sealed tail light construction that also includes a conventional bayonet bulb socket.
The Ploeger construction relies upon another form of spring to securely urge the base portion of a bayonet-type bulb against a surrounding bayonet socket configuration.
Newman mounts a bayonet type bulb by a conventional bayonet receptacle, with his disclosed novelty residing in a molded junction box. Newman also illustrates separate wire interconnections between the bulb socket and a junction box, unlike the bulb-mounting taught by the present invention.
The patent to Dupree employs a conventional spring mounted bayonet base where the novelty is in the method for forming the separate sleeve and center pin for a wire connection. The conventional bayonet bulb mount of Dupree also does not provide for a structure that will allow automatic wiping against corrosion build-up, as taught herein.
The vehicle lamp holder of Altissimo also includes a conventional bayonet mounting wherein the bayonet pins on the bulb are held tightly against movement.
The patent to Quelland is, once again, a conventional bayonet lamp socket with a spring loaded connection between the entire socket assembly and a mounting receptacle. The parking light of Cheng has a screw-in bulb connection, unlike the present invention and further illustrates conventional wiring between a bulb socket and the vehicle. The patent to Schumacher illustrates a molded plastic bayonet mount that rigidly holds the bulb in place without allowing for a wiping movement in response to vibration during vehicle operation. The springed contact 24 in Schumacher urges the bayonet pin base against the cooperating bayonet socket to ensure a rigid mounting.
The patent to Mears teaches a mounting for a conventional bayonet socket with a particularized form of elastic snap ring. Again, such a conventional socket cannot take advantage of automotive vibrations to maintain a bulb contact free from corrosion.
The patent to Baldwin shows a non-analogous embedded pin-type light assembly, also rigidly mounted within a socket member.
The patents to Benander and Wood yet further illustrate conventional screw-in lamp socket designs, wherein a bulb is rigidly held through a screw thread. Such conventional screw-in sockets provide no means for avoiding corrosion build-up. Similarly, the patents to Fraser and Del Camp further represent known forms of conventional bayonet socket mounts without the provision of a structure which will ensure automatic wiping against corrosion build-up.
In summary, none of the above references begin to teach a structure which provides for particularly economical molded lamp mounting, and one which allows a wiping action from the vibrations of vehicular operation against corrosion.
SUMMARY OF THE INVENTION
The present invention relates to a completely molded lamp housing for holding a bayonet-type bulb in a particularly unique manner. The present invention may also be considered a vehicular lamp housing, of the type commonly found on large vehicles such as school buses. The entire lamp housing is integrally molded with all appropriate electrical contacts, and associated individual elements, requiring no conventional wiring between the bayonet bulb and an external source of power. It is a significant object of the present invention to provide a vehicular lamp housing assembly that will avoid the necessity for individually wiring a socket assembly to the vehicle, while ensuring that electrical contacts are wiped free of corrosion and dirt while externally mounted on a vehicle surface.
The present invention is characterized by a housing base that includes an integrally molded extending contact assembly. This extending contact assembly functions as the support means for a bayonet-type bulb and also provides a rigid mounting platform for an integrated contact strip. The present invention takes advantage of a particular configuration for the bayonet-type bulb mounting, one which allows the bulb to pivot about the bayonet pins in response to vibrations encountered during vehicle operation. By way of background, bayonet-type bulbs are widely used in vehicle applications, constituting usually a 12 volt bulb having a pair of diametrically extending pins around its base. The bayonet pins are normally inserted into a cylinder metal housing that includes a spiral channel to form a click lock configuration. The cylindrical housing is conventionally of metal, so that the ground connection of the bayonet bulb is made through the contacts of the bulb base within the metallic housing. The positive electrical connection for the bayonet bulb is then made through a spring loaded and electrically insulated contact within the base of the surrounding metal housing. Consequently, bayonet-type bulbs are rigidly urged into a locking position by the action of the positive electrical contact located in the base of the socket. Because this positive electrical socket assembly urges the bayonet pins into tight engagement within the corresponding bayonet detent, the bulb is quite rigidly held in the socket.
In distinction, the present invention does not hold a bayonet-type bulb rigidly with an encompassing bayonet-type socket, but rather takes advantage of the geometry of the bayonet-type bulb in a completely different manner.
The present invention teaches a molded lamp housing comprised of a molded plastic contact assembly to allow for a pivoting action of the bulb, with the pivoting action being retarded only by a contact with a cantilevered ground strap. The cantilevered ground strap functions both to make a ground connection between the bulb and the vehicular electrical system, and afford the sole means for holding the bayonet-type bulb within the bulb support.
The present molded lamp housing does not require that a separate socket be wired into the vehicle electrical system, but constitutes a significantly improved lamp housing for vehicular application. The present invention teaches a particularly economical mounting for a bayonet-type bulb in vehicle applications which significantly avoids the problem of corrosion build up through a natural wiping action that is the direct result of the structure taught herein. Therefore, the present invention obtains a synergistic result from a cooperation of elements; corrosion is obviated as a natural consequence of the environment to which the present invention is directed.
Other advantages of the molded lamp housing taught herein will be more apparent from considering the detailed description which follows, in which reference is made to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a respective view showing the preferred embodiment of the present invention;
FIG. 2 is a partial section view of this preferred embodiment;
FIG. 3 is an explosion view illustrating further features according to the preferred embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment for the present invention is illustrated in FIG. 1 to include a housing base 2, which is of an electrically insulating material such as plastic. The housing base 2 includes a first surface that has an integrally formed bulb support extending outwardly, as shown broadly at 4. The bulb support 4 is preferably an integrally molded extension on the first surface of the housing 2, though it may be attached to the housing by a subsequent manufacturing operation. The bulb support 4 is further defined by a concave channel recess that is defined by a pair of oppositely disposed extensions of the base, shown at 6 and 8 in FIG. 1. The extension 6 and 8 therefore define an outwardly open concave channel recess, wherein the recess is substantially parallel to the first surface of the base 2 for the purposes which will be more particularly described hereafter.
The mount extension 6 includes an outwardly open aperture 14, extending inwardly from the outer surface of the extension 6. In like fashion, another outwardly open aperture extends inwardly from the outer surface of the oppositely disposed extension 8. As shown in FIG. 1, these apertures are configured to allow the pins 18 on a conventional bayonet-type bulb 10 to be normally inserted. After the bulb 10 has been partially inserted into the concave recess within the bulb support, a ground strap 12 is then positioned as the sole holding means for the bulb. The ground strap 12 is shown to include a ground strap mounting extension 26, and the mounting screw at 24. In this fashion, the ground strap is cantilevered over the base of the bayonet bulb 10 from a point at 24 which is radially outward and parallel with the center line of the so positioned bulb 10. As further shown in FIG. 1, the housing base 2 has a substantially circular first surface, including a flange surface at its periphery together with locating pins 22 and a conventional form of sealing gasket 20.
With reference to FIG. 2, further constructional details of the present invention can be more fully appreciated, particularly the interaction of the cantilevered metallic contact strip 30 which supplies a relatively positive electrical charge to the bayonet bulb. As shown most clearly in FIG. 2, the ground strap 12 includes a cantilevered portion 28 that extends above and in substantial parallel alignment to concave channel recess 32. As a consequence of this alignment, there is a line contact between the underside of the cantilevered portion of the ground strap 28 and the base of the bulb 38. The planar undersurface of the ground strap 28 will contact the circular configuration of the bulb base 38, as shown at 40. When the bulb 10 is substantially parallel to the first surface of the housing 2, there will be a line contact defined between the underside of the cantilevered ground strap 28 and the circular surface of the bulb base 38. For any rotation of the base 38 around the bayonet pins 18, the line contact will be changed to a point contact; that is to say that some portion of the cantilevered ground strap portion 28 will in all cases contact a portion of the bulb base 38 for any rotated position. Similarly, there will be a positive electrical contact between electrical contact 36 on the bulb and the cantilevered portion of the contact strip 30. As shown most clearly in FIG. 2, the contact strip extends in a substantially normal fashion from the first surface 2 through the bottom of the concave recess at 32, and into the outwardly open recess defined between the first and second extensions 6 and 8, respectively. As shown in FIGS. 1 and 2, the housing base 2 is illustrated to be circular, with the bulb 10 being supported so that the filament end is proximate the geometric center of the substantially circular first surface 2. To ensure that the bulb is positioned for the optimum optical advantage, the inner end of the bulb support 4 terminates proximate, but radially outward from the geometric center of the substantially circular first surface 2.
Again, with reference to FIG. 1, it can be seen that the distance between the oppositely disposed extensions 6 and 8 is less than the distance from the top of the extensions to the bottom of the concave channel recess. As a consequence, as most clearly shown in FIG. 2, the concave recess is operable to allow the bayonet base light bulb to pivot about its pins 18, which are held within the outwardly open apertures 16. When the bulb base 38 self pivots about the pins 18, there will be a wiping action between the ground strap and the base, at 40, and also a wiping action between the bulb base 36 and the cantilevered portion of the contact strip at 30. Furthermore, the electrical contact strip 30 is laterally disposed, with respect to the aperture 16, at a distance less than the dimension between the base of the bulb 30 and the bulb pins 18. Therefore, there will be a resilient urging of the cantilevered contact strip 30 against the base portion 36, as there is also a resilient urging between the ground strap 28 and the bulb base 38, as indicated at 40 in FIG. 2. The contact strip 30 further includes a portion extending normally through the housing base 2, to terminate as an exposed electrical contact connection, shown at 34. The ground strap 12 and the contact strip 30 are preferably phosphrous bronze to ensure adequate resiliency and good electrical conductivity. Of course any other resilient metal strip would be equivalent, provided the geometry is essentially as shown in FIG. 2 and herein described.
FIG. 3 illustrates the entire assembly of the vehicle lamp, wherein there is additionally a refractive lens superposed upon the first surface of the housing at 2. FIG. 3 illustrates, in explosion view, a final assembly of a conventional refractive lens upon the molded lamp housing of the present invention. The bulb 10 is normally inserted into the apertures 16 so that the base of the bulb will slightly distend the cantilevered contact strip 30. When the bulb 10 is partially inserted into the concave recess 32, the bulb 10 will be supported only by contact of the bayonet pins 18 within the apertures 16, and urged radially inward by a contact between the contact strip 30 and the base of the bulb. Upon such insertion of the bulb 10, the cantilevered portion of the ground strap 28 is aligned with the base of the bulb 38, and a ground strap mounting screw 24 is inserted into the lamp support extension 26. The ground strap 12 further includes a portion extending upon and towards an edge of the first surface, with a mounting aperture 44 in the grounding strap. As shown most clearly in FIG. 2, the diameter of the ground strap aperture 44 is less than a corresponding vehicle body mounting aperture 46 extending through the housing base 2. Additionally, the gasket 20 includes a gasket aperture which is of greater diameter than the aligned aperture 44 within the ground strap 12. With this arrangement a grounding screw 50 may be tightened down upon ground strap 12 through the housing mounting aperture 46, and into a metallic portion of a vehicle, shown at 48. With this arrangement a secure ground connection between the ground strap 12 and the body of the vehicle 48 is ensured. FIG. 3 illustrates that the grounding screw 50 may be inserted after the superposed refractive lens is in place, a result simply obtained by ensuring that the access hole in the refractive lens is larger than the diameter of the head of the ground screw 50. When the housing base 2 is of a substantially circular configuration, as shown in this preferred embodiment, the concave recess 32 is preferably diametrically aligned upon the circular surface, simply to ensure that the best optical performance will be obtained by the bulb 10 which is so held. Of course, if an oval, square or other shaped housing base is employed, the bulb support assembly 4 may simply be formed in any suitable relative orientation to the housing base 2 to ensure that the filament portion of the bulb 10 is positioned at the desired point. The bulb support base 4 may further include, as shown in FIG. 2, a centrally located relief hole at 42. Within this relief hole at 42, there may optionally be positioned a coiled spring to urge the base of the bulb 38 upwardly towards the contact strip 28. However, the distance between the bulb socket mount extensions 6 and 8 effectively holds the base of the bulb 38, and since there is a slight space between the relative bottom of the bulb base 38 and the top of the concave recess 32, the present invention allows the entire bulb 10 to vibrate sympathetically with the vehicle to ensure wiping of the two electrical contact areas. Because this wiping would be fairly regular, during normal road operation, corrosion will be effectively prevented from building up at the contact point 40 and the contact point at 36. Unlike prior art devices, there is no intent to maintain the bulb base 38 in an encompassing cylindrical metal sleeve, wherein the grounding connection is assured only between the bayonet pin 18 and any surrounding cylindrical metal grounding socket. Rather, the present invention ensures a resiliently urged grounding connection at 40, together with a resiliently urged contact at the base of the bulb 36. The geometry of the present bulb support ensures that there will be a slight movement of the bulb 10 within the concave recess 32, so that inevitable corrosion will be constantly wiped from the respective contact areas.
It is apparent that though one preferred embodiment of the present invention has been described, changes and modifications can be made therein without departing from the spirit of the invention which is expressed solely by the appended claims.
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A molded lamp housing for vehicular application, requiring no wires for making electrical connections to a lamp socket, with all electrical contact pieces molded in place. The entire bulb mounting is accomplished through a single screw connection which also serves as a grounding connection. Significantly, the problem of corrosion build-up on either the bulb contact or ground strap is obviated, since normal vehicle vibration of the bulb will cause a wiping action to inhibit such a build-up.
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FIELD OF THE INVENTION
[0001] Embodiments of the present invention are directed to cooling of rack-mounted devices, and more particularly to a data center infrastructure having a cooling system.
BACKGROUND OF THE INVENTION
[0002] Electronic equipment racks generally are designed to receive a number of electronic components arranged vertically in the rack, mounted on shelves, and/or to front and rear mounting rails. The electronic equipment may include, for example, printed circuit boards, communications equipment, computers, including computer servers, or other electronic components.
[0003] Electronic equipment housed in racks produces a considerable amount of heat, which undesirably affects performance and reliability of the electronic equipment. Often the heat produced by the rack-mounted components is not evenly distributed in the racks. Temperature gradients causing elevated inlet temperatures at tops of racks, for example, reduce equipment reliability substantially. Equipment reliability may be reduced by as much as half the reliability of specific equipment function for each 10° F. rise in temperature. Accordingly, rack-mounted computer systems typically require effective cooling systems to maintain operational efficiency. Cooling can be accomplished by introducing cooled air into an equipment rack causing the air to flow through equipment in the rack and exit the rack at an increased temperature, thereby removing some of the heat. The heat removed from the rack is typically returned into the room containing the racks and the entire room is cooled using a relatively large air conditioning system.
SUMMARY OF THE INVENTION
[0004] A first aspect of the present invention is directed to a modular data center. The modular data center includes a plurality of racks, each of the racks having a front face and a back face, wherein the plurality of racks is arranged in a first row and a second row, such that the back faces of racks of the first row are facing the second row, and the back faces of the racks of the second row are facing the first row. The data center also includes a first end panel coupled between a first rack of the first row and a first rack of the second row, the first end panel having a bottom edge and a tope edge. Further, the data center includes a second end panel coupled between a second rack of the first row and a second rack of the second row, the second end panel having a top edge and a bottom edge, and a roof panel is included to couple between the top edge of the first panel and the top edge of the second panel.
[0005] The modular data center can be designed so that the roof panel is coupled to a top portion of at least one rack of the first row and to a top portion of at least one rack of the second row, such that the roof panel, the first end panel, the second end panel, and the first and second rows of racks form an enclosure around an area between the first row of racks and the second row of racks. The plurality of racks can further include cooling equipment that draws air from the area, cools the air and returns cooled air out of the front face of one of the racks. At least one of the first end panel and the second end panel can include a door. Further, at least a portion of the roof panel can be translucent. The modular data center can have at least one rack that includes an uninterruptible power supply to provide uninterrupted power to equipment in at least one other rack of the plurality of racks. The first row of racks in the modular data center can be substantially parallel to the second row. In addition, the modular data center can be designed such that one of the plurality of racks includes cooling equipment that draws air from an area between the first row and the second row, cools the air and returns cooled air out of the front face of one of the racks.
[0006] Another aspect of the present invention is directed to a method of cooling electronic equipment contained in racks in a data center. The method includes arranging the racks in two rows, including a first row and a second row that is substantially parallel to the first row, with a back face of at least one of the racks of the first row facing towards a back face of at least one of the racks of the second row. The method also includes forming an enclosure around an area between the first row and the second row, and drawing air from the area into one of the racks and passing the air out of a front face of the one of the racks.
[0007] The method can include a further step of cooling the air drawn into the one of the racks prior to passing the air out of the front face. The step of forming an enclosure may include coupling first and second side panels and a roof panel between the first row and the second row. At least one of the first side panel and the second side panel may include a door and the roof panel can include a translucent portion. Additionally, the method can include using an uninterruptible power supply to provide power to equipment in the racks.
[0008] Yet another aspect of the present invention is directed to a modular data center that includes a plurality of racks, each of the racks having a front face and a back face, wherein the plurality of racks is arranged in a first row and a second row, such that the back faces of the racks of the first row are facing the second row, and the back faces of the racks of the second row are facing the first row. The modular data center further includes means for enclosing a first area between the first row and the second row, and means for drawing air from the enclosed area, cooling the air, and returning cooled air to a second area.
[0009] The means for drawing air can further include means for passing cooled air through the front face of one of the racks. The modular data center can also be comprised of means for providing uninterruptible power to equipment in the racks. Access means for allowing access into the first area may also be a design feature of the modular data center.
[0010] The invention will be more fully understood after a review of the following figures, detailed description and claims.
BRIEF DESCRIPTION OF THE FIGURES
[0011] For a better understanding of the present invention, reference is made to the figures which are incorporated herein by reference and in which:
[0012] FIG. 1 is a perspective view of a modular data center cooling system for rack-mounted equipment in accordance with one embodiment of the invention;
[0013] FIG. 2 is a top view of another modular data system, similar to the system of FIG. 1 ; and
[0014] FIG. 3 is a block flow diagram of a process of cooling equipment mounted in modular data centers in one embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0015] Embodiments of the invention provide a data center infrastructure having a cooling system for cooling rack-mounted electronic equipment. Embodiments of the invention provide a modular data center for rack-mounted equipment, wherein the modular data center provides power distribution, cooling and structural support for the rack-mounted equipment. The power distribution unit and cooling is provided in some embodiments using redundant systems to prevent downtime due to electrical or mechanical failures. As understood by those skilled in the art, other embodiments are within the scope of the invention, such as embodiments used to provide infrastructure for equipment other than electronic equipment.
[0016] A system for providing power distribution for rack-mounted equipment which can be used with embodiments of the present invention is described in U.S. patent application Ser. No. 10/038,106, entitled, “Adjustable Scalable Rack Power System and Method,” which is herein incorporated by reference.
[0017] Referring to FIG. 1 , a perspective view of a modular data center 10 is shown. The modular data center 10 includes a power distribution unit 14 , a power protection unit 12 , a floor mounted cooling unit 16 , equipment racks 18 , and a hot room 22 . The modular data center 10 also has a door 52 having a window 54 , a roof 56 , a cold water supply and return 60 , and a voltage feed 58 . The data center 10 is a modular unit comprised of the power distribution unit 14 , the power protection unit 12 the floor mounted cooling unit 16 , and equipment racks 18 positioned adjacent to each other to form a row 32 and a row 34 . Row 32 and row 34 are substantially parallel. The power distribution unit 14 and the power protection unit 12 can be located directly adjacent to one another, and can be located at the end of one of the rows. The floor-mounted cooling unit 16 may be located and positioned adjacent to the power distribution unit 14 . Remaining enclosures forming the at least one additional row in the data center 10 are equipment racks 18 . The hot room 22 is located between row 32 and row 34 , and rows 32 and 34 comprise two of the perimeter walls of the modular data center 10 .
[0018] The power distribution unit 14 typically contains a transformer, and power distribution circuitry, such as circuit breakers, for distributing power to each of the racks in the modular data center 10 . The power distribution unit 14 provides redundant power to the racks 18 and can monitor the total current draw. An uninterruptible power supply can provide uninterruptible power to the power distribution unit 14 . Preferably, the power distribution unit 14 includes a 40 kW uninterruptible power supply having N+1 redundancy, where the ability to add another power module provides N+1 redundancy. In one embodiment of the invention, input power to the power distribution unit 14 is received through the top of the rack from a voltage feed 58 . In one embodiment, the voltage feed 58 is a 240 volt feed coupled to the power distribution unit 14 that enters through the roof panel 56 . Alternatively, the input power may be received from underneath the rack, as through a raised floor, or through the back of the rack.
[0019] The power protection unit 12 provides redundant power protection for centralized information technology equipment, as is contained in the equipment racks 18 . The power protection unit 12 can have individual power modules and battery modules that can be individually added or removed to accommodate different load requirements. The use of multiple power modules and battery modules provides redundancy by allowing continued operation despite the failure of any one power module or battery module. For example, the power protection unit can include a Symmetra PX® scalable, uninterruptible power supply having a three-phase input and a three-phase output, available from American Power Conversion Corporation, of West Kingston, R.I., or the power protection unit can include one of the uninterruptible power supplies described in U.S. Pat. No. 5,982,652, titled, “Method and Apparatus for Providing Uninterruptible Power,” which is incorporated herein by reference.
[0020] The floor mounted cooling unit 16 provides heat removal by use of a chilled water supply, which enters the unit through supply line 60 . Alternatively, the cooling units can provide heat removal using DX compressorized cooling via use of a direct expansion refrigerant-based unit, which can be in the unit itself. The cooling unit contains a primary chilled water coil and secondary direct expansion coil within the same frame. The cooling unit can be configured for air, water or glycol use. Cooled air can be released through the bottom of the unit or the top of the unit. In one embodiment of the invention, cool air is released from the cooling unit 16 out its front face, so that the air flow is from the back of the rack and out the front of the rack. The cooling unit 16 can further be configured as one, two or three modules. In the embodiment shown in FIG. 1 , a three-module cooling unit is used.
[0021] In the embodiment of FIG. 1 , each of row 32 and row 34 is comprised of six racks. In embodiments of the invention, the number of racks and the function of the equipment in the racks can vary. In one embodiment of the invention, the racks 18 are modified standard 19 inch racks, such as those available from American Power Conversion Corporation of West Kingston, R.I., under the trade name NETSHELTER VX Enclosures®.
[0022] The back face of each of the power distribution unit 14 , the power protection unit 12 , the floor mounted cooling unit 16 , and the equipment racks 18 faces the interior of the modular data center 10 , or the hot room 22 . Essentially, the back faces of the racks in row 32 face the back faces of the racks in row 34 . In one embodiment, the equipment racks 18 have their rear doors removed so that each rack 18 remains open to the inside of the hot room 22 . In the embodiment shown, the modular data center 10 contains seven equipment racks 18 . Alternatively, in another embodiment, six equipment racks 18 complete the rows, but more than seven equipment racks 18 can complete the rows contained in the data center 10 and can be adjacent to one another or adjacent to other enclosures in the data center 10 , such as the power distribution unit 14 , the power protection unit 12 , or the floor mounted cooling unit 16 .
[0023] The door 52 located at the end of the row of racks is attached with hinges 53 to a detachable frame 55 . The detachable frame 55 is located behind the power protection unit 12 . The detachable frame may be positioned behind any one of the power protection unit 12 , the power distribution unit 14 , or the equipments racks 18 , depending on which of the units are positioned at the end of a row in the data center 10 . The detachable frame 55 allows the door 52 to be quickly removed for replacement of the power protection unit 12 if necessary. The hot room is accessible by the door 52 and can be monitored through the observation window 54 . Preferably, a door 52 is located at each end of the hot room 22 . Generally, the door 52 is a 2×36 inch insulated, lockable steel door having an insulated observation window 54 .
[0024] The cold water supply and return 60 can enter the hot room through supply pipes into the roof 56 or directly into the roofs of the racks. The voltage feed 58 can also enter through the roof 56 or through the roofs of the racks. Alternatively, the cold water supply and return 60 and the voltage feed 58 enter the hot room through a raised floor on which the modular data center rests or from another location outside of the room and into the racks, such as into the sides of the racks.
[0025] The roof panel 56 is preferably a semi-transparent plexiglass roof panel supported by steel supports 62 that are positioned at intervals along the length 72 of the data center 10 . The roof 56 extends to cover the top of the hot room 22 located in the middle of the rows of racks. The roof 56 can be easily detachable to allow for removal of racks 18 or the power protection unit 12 when necessary. A roof panel 56 constructed of semi-transparent plexiglass allows room light to enter the space defining the hot room 22 . Additionally, the plexiglass roof 56 is preferably substantially airtight.
[0026] The hot room 22 is completely enclosed and has walls formed by the backside of the racks 18 and walls comprised of the door 52 attached at each end of the hot room 22 . Alternatively, panels without doors can be the walls that complete the hot room. The hot room 22 is a substantially airtight passageway when the roof panel 56 is in place. Thus, the modular data center 10 is an enclosed computer infrastructure defined on its outside perimeter by the front face of each of the racks 18 , power protection unit 12 , power distribution unit 14 , and cooling unit 16 , and having a hot room 22 in its midsection. The outside walls of the hot room formed by the doors 52 are a portion of two of the outside walls of the modular data center 10 .
[0027] Referring to FIG. 2 , a top view of a modular data center 10 in one embodiment of the invention is shown. The modular data center of FIG. 2 is similar to that of FIG. 1 , but has five racks in each of row 32 and row 34 , rather than the six racks in each row of FIG. 1 . With like numbers referring to like embodiments, the modular data center 10 of FIG. 2 is comprised of the power distribution unit 14 , the power protection unit 12 , the floor mounted cooling unit 16 , the equipment racks 18 , and the hot room 22 . The power protection unit 12 is positioned directly adjacent to one side of the power distribution unit 14 , while a floor-mounted cooling unit 16 is positioned on the other side of the power distribution unit. A service clearance area 20 surrounds the modular data center 10 . In FIG. 2 , an embodiment of the invention is shown having six equipment racks 18 and a cooling unit 16 having two modules.
[0028] The dimensions of the modular data center 10 depend on the number of racks included in each of the rows of racks. For example, and referring again to FIG. 1 , a data center 10 having six equipment racks 18 can have a width of 120″, indicated by arrow 28 , a length of 120″, indicated by arrow 29 , and a height of 36″, indicated by arrow 24 . The height 24 of the data center can be 36″, while the service clearance is preferably 36″ in width 26 . With the inclusion of the service clearance 20 , the floor surface area for the data center 10 is, preferably, a length 30 of 192″ and a width 30 of 192″. Alternatively, and referring to FIG. 2 , a data center 10 having seven equipment racks 18 can have a width of 120″ and a length of 144″, while the height of the data center 10 is 36″. With the inclusion of the service clearance 20 , the floor surface area for an alternate data center is 192″ by 216″. The dimensions of the modular data center are given only as examples, but can vary significantly depending upon the type and size of racks used to design the data center.
[0029] The modular data center 10 is operational when provided with a source of chilled water 60 and a voltage feed 58 . The data center can include a number of different power input designs, but is preferably a 40 kW design, allowing 6.7 kW/rack in a system having six equipment racks 18 , or 5.7 kW/rack in a system having seven equipment racks 18 , for example. Cold water enters the floor mounted cooling units 16 via supply lines 60 . A common supply line 60 can provide cold water to one or more cooling units simultaneously, as the cooling units 16 are connected to the common supply 60 with flexible hose that is easily disconnected.
[0030] The modular data center 10 provides cooling for equipment in the data center as follows. Air from the room, or ambient air, filters through the front of the racks 18 to cool the equipment stored in the racks 18 . Air enters through the front of the racks 18 and is expelled out of the backside of the racks 18 . As the air passes through the equipment racks 18 , the temperature of the air rises. The respectively warmer air is expelled into the hot room 22 . The hot room 22 contains the warm air and prevents the warm air from mixing with air in the surrounding room. The cooling unit 16 draws warm air from the hot room and return cool air to the room outside the data center 10 . The warm air enters the cooling units 16 directly from the hot room 22 . The cold water supply 60 acts within the cooling unit to lower the temperature of the air, and the cooled air is then released into the surrounding area. The air is recycled to the surrounding room at a substantially cooled temperature. For example, the cooling unit 16 generally receives air from the hot room at 95° F. and cools it to a temperature of approximately 72° F. before it is released into the area surrounding the data center 10 . The floor mounted cooling unit 16 operates at substantially higher supply and return temperatures, allowing realization of high capacity without latent heat removal.
[0031] Referring to FIG. 3 , with further reference to FIGS. 1-2 , the data center 10 is configured to perform a process of cooling equipment stored in enclosed racks using an infrastructure having independent power and coolant supplies. The process 100 includes the stages shown, although the process 100 may be altered, e.g., by having stages added, deleted, or moved relative to the stages shown.
[0032] The process 100 of FIG. 3 includes stage 102 , wherein power is supplied from a power distribution unit to a plurality of equipment racks 18 . The equipment racks 18 may contain a variety of electronic equipment that requires a consistent power supply to avoid system downtime. A voltage feed 58 is connected to the power distribution unit 14 , and a power protection unit 12 is installed adjacent to the power distribution unit 14 to ensure redundant power supply.
[0033] At stage 104 , the racks 18 draw cool air from the surrounding room through the front face of the racks 18 . There may, for example, be an air distribution unit within the racks and/or within equipment contained in the racks that draws the room air into the rack 18 and distributes the air throughout the rack to cool components contained in the rack. As the air passes through the rack 18 , the air increases in temperature.
[0034] At stage 106 , the racks 18 expel the air at an increased temperature into the hot room 22 . The air is expelled out of the backside of the racks 18 . As described above, in one embodiment, the racks 18 do not have rear doors. In other embodiments, rear doors may be included on the racks with the warm air being expelled into the hot room through vents in the doors. Air is held in the hot room 22 at an increased temperature and mixing of the warm air with the surrounding ambient air is prevented.
[0035] At stage 108 , the cooling unit draws the warm air from the hot room 22 . The cooling unit 16 uses the cold water from the cold water supply 60 to cool the air from the hot room. At stage 110 , the cooled air is released from the cooling unit into the surrounding room, which completes the cooling cycle. The air in the surrounding room is then drawn into the racks 18 once again, and the cycle continues.
[0036] Other embodiments are within the scope and spirit of the appended claims. For example, air could be forced up through the equipment racks 18 . Air moved through the racks 18 could be of varying temperatures, including hot air. The data center 10 may be configured to distribute gases other than air. Additionally, a refrigerant or other coolant may be used rather than cold water. Further, a controller can be coupled to the data center 10 to monitor air temperatures and flow rates, as well as power supply so that each rack is provided adequate power consistently. A data center may contain a single equipment rack 18 having a single cooling unit 16 creating an individual data center, whereby power is distributed to a single data center 10 or multiple single-rack data centers simultaneously.
[0037] Further, in embodiments of the present invention, the roof over the hot area may include a number of fans that are controlled to exhaust air from the hot area in the event of a failure of an air conditioning unit in the modular data center, and/or when air temperature in the hot area exceeds a predetermined limit.
[0038] Having thus described at least one illustrative embodiment of the invention, various alterations, modifications and improvements will readily occur to those skilled in the art. Such alterations, modifications and improvements are intended to be within the scope and spirit of the invention. Accordingly, the foregoing description is by way of example only and is not intended as limiting. The invention's limit is defined only in the following claims and the equivalents thereto.
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A modular data center includes a plurality of racks, each of the racks having a front face and a back face, wherein the plurality of racks is arranged in a first row and a second row, such that the back faces of racks of the first row are facing the second row, and the back faces of the racks of the second row are facing the first row, a first end panel coupled between a first rack of the first row and a first rack of the second row, the first end panel having a bottom edge and a tope edge, a second end panel coupled between a second rack of the first row and a second rack of the second row, the second end panel having a top edge and a bottom edge, and a roof panel coupled between the top edge of the first panel and the top edge of the second panel.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation under 35 U.S.C. §115 and claims priority to and the benefit of U.S. Non-Provisional application Ser. No. 13/811,037, filed on Mar. 21, 2013, which was a National Stage Application under 35 U.S.C. §371 of International Application No. PCT/US2011/044397, filed Jul. 18, 2011, which claimed priority under 35 U.S.C. §119(e) and the benefit of U.S. Provisional Application Ser. No. 61/365,689 filed Jul. 19, 2010, the entire disclosures of which are hereby incorporated by reference in their entireties.
FIELD OF THE INVENTION
[0002] This invention relates to the field of medical treatment methods, including intravenous methods of administration of drugs to a subject.
BACKGROUND
[0003] Glyburide (also known as, e.g., glibenclamide) is a sulfonylurea drug used in treating diabetes. The systematic name of glyburide is 5-chloro-N-(4-[N-(cyclohexylcarbamoyl)sulfamoyl]phenethyl)-2-methoxybenzamide. Glyburide preferentially binds to and affects the sulfonylurea receptor 1 (SUR1) but at higher concentrations also binds to and affects the sulfonylurea receptor 2 (SUR2).
[0004] Glyburide has been suggested as a therapy for acute stroke (ischemic and hemorrhagic), traumatic brain injury (TBI), spinal cord injury (SCI), myocardial infarction (MI), shock (including hemorrhagic shock), organ ischemia, and ventricular arrhythmias. The pharmacokinetic parameters of intravenous glyburide have been described in numerous publications (see Table 1). All patents and publications discussed herein are hereby incorporated by reference in their entireties.
[0000]
TABLE 1
Pharmacokinetic Parameters of Glyburide after Intravenous Administration
Publication
McEwen 1
Spraul 2
Rydberg 3
Rogers 4
Sorgel 5
Morrison 6
Neugebauer 7
Jonsson 8 †
Patient
Healthy
Healthy
Healthy
Healthy
Healthy
Healthy
NIDDM(Non
Healthy
Population
males
males and
males and
males and
males
males and
insulin dependent
males and
females
females
females
females
diabetes mellitus)
females
males and females
N
20
52
8
8
24
8
20
10
Dose (mg)
1.48‡
4.0
1.0
1
1.5
2.4
1.25
2.0
C max (ng/mL)
—
—
—
331 ± 65
648
376
196
Clearance:
2.92‡
—
5.46*‡
—
—
4.42
4.41
1.68‡
(L/h)
(mL/min)
49
—
91*‡
—
74.7 ± 22
73.7‡
73.5‡
101.3
V d (L)
9.7‡
—
10.9*‡
—
11.22 ± 3
7.4
11.6‡
—
Beta (1/h)
0.3
—
0.52*‡
0.517
—
0.62
0.38
—
t 1/2 (h)
2.46
1.50 ± 0.36
1.47 ± 0.42
1.47
4.22 ± 1
1.18‡
1.82
1.15
Tmax(h)
—
—
—
—
0.09
—
—
—
Mean subject
74.1
—
74.6
57-88
—
69.7
—
—
weight (kg)
*normalized to 70 kg
†Data from Caucasian patients
‡Not presented in the publication, data generated from information presented in the publication.
AUC, area under the time-concentration curve;
C max , the maximum concentration of the drug;
V d , the volume of distribution of drug
1 McEwen, et al. 1982;
2 Spraul et al. 1989;
3 Rydberg et al. 1995;
4 Rogers et al. 1982;
5 Sorgel et al. 1997;
6 Morrison et al. 1982;
7 Neugebauer et al. 1985;
8 Jonsson et al. 2000.
[0005] While the intravenous (“i.v.” or “IV”) glyburide dose in these and other studies was delivered within a few minutes in the majority of studies, several of the studies included continuous infusions of an hour or more. Garrel et al. (1987) administered a 1 mg i.v. bolus dose, followed by 0.3 mg/h for 17 hours, to six subjects with IDDM (insulin-dependent diabetes mellitus); the total dose was 6.1 mg glyburide. In addition, Groop et al. (1987) dosed 16 normal subjects with a total of 2.1 mg over 4 hours, and Neugebauer et al. (1985) dosed ten normal subjects with a total of 2 mg i.v. glyburide over 1 hour.
[0006] Doses for bolus infusions (i.e., infusions of three minutes or less) ranged between 1 and 2.4 mg (Rydberg et al. 1994).
[0007] The doses and duration of dosing of the studies described above are presented in Table 2.
[0000]
TABLE 2
Dose and Duration of Dosing in Select Clinical Studies of Intravenous Glyburide.
Garrel et al.
Groop et al.
Neugebauer
Rydberg et
Bank et al.
1987
1987
et al. 1985
al. 1994
2000
N
6
16
10
8
12
Bolus dose
1
mg
0.84
mg
N/A
2.4
mg
—
Duration of
17
hours
4
hours
1
hour
—
10
min
infusion
Infusion
0.3
mg/hr
0.35
mg/hr
2
mg/hr
—
6
mg/hr
dose/hr
Bolus dose
1
mg
0.84
mg
N/A
2.4
mg
—
Total dose
6.1
mg
2.1
mg
2
mg
2.4
mg
1
mg
[0008] Maximum glyburide plasma concentrations were provided for some studies, and ranged from 200-436 ng/mL (Rogers et al. 1982; Groop et al. 1987; Bank et al. 2000; Jonsson et al. 2000). Subjects in the study by Groop et al. (1987), who received a bolus dose followed by continuous i.v. infusion, reached a mean glyburide C max of 240 ng/mL after administration of the bolus, and a steady-state concentration of 88-93 ng/mL during the 220 minutes of continuous infusion.
SUMMARY OF THE INVENTION
[0009] Methods of administering glyburide, or other drug, are disclosed. The novel methods disclosed herein include methods of administering glyburide, or other drug, over periods of more than an hour to a subject, and preferably over periods of many hours (e.g., about 72 hours or about 96 hours or about 120 hours), and in particular include intravenous methods of administering glyburide, or other drug, to a subject. The methods disclosed herein may be useful for treating a subject in need of treatment for, e.g., acute stroke (ischemic and hemorrhagic), traumatic brain injury (TBI), spinal cord injury (SCI), myocardial infarction (MI), shock (including hemorrhagic shock), organ ischemia, and ventricular arrhythmias. In these and other indications, the use of intravenous glyburide is preferable as targeted glyburide plasma levels can be more quickly and reliably be reached and maintained. The methods disclosed herein provide rapid achievement of therapeutic levels of glyburide, or other drug, following initiation of drug administration, and also provide for maintenance of therapeutic levels of glyburide, or other drug, over an extended period of time, (e.g., for about 72 hours or about 96 hours or about 120 hours). In addition, the methods disclosed herein provide rapid achievement of therapeutic drug levels, maintenance of therapeutic drug levels for an extended period of time, and further avoid excessive levels of drug and so avoid possible drug side-effects.
[0010] Embodiments of the methods of administering glyburide, or other drug, to a subject include intravenous administration of a bolus of glyburide, or other drug, followed (either substantially immediately, or after a delay after completion of the bolus administration) by a continuous infusion of glyburide, or other drug. Further embodiments of the methods of administering glyburide, or other drug, to a subject include intravenous administration of a first bolus of glyburide, or other drug, followed (either substantially immediately, or after a delay after completion of the bolus administration) by a continuous infusion of glyburide, or other drug, followed by a second bolus of glyburide, or other drug. In further embodiments, a second infusion may follow a second bolus. In yet further embodiments, multiple boluses and multiple infusions may be administered to a subject.
[0011] In embodiments, the administration of glyburide to a subject extends over periods of more than an hour to a subject; in particular embodiments, the methods of administration of glyburide to a subject are intravenous methods of administration of glyburide to a subject where the administration extends over periods of more than an hour. For example, in embodiments, administration of glyburide, or other drug, extends over periods of more than about 72 hours. In other embodiments, administration of glyburide, or other drug, extends over periods of more than about 10 hours, or more than about 20 hours, or more than about 30 hours, or more than about 40 hours, or more than about 50 hours, or more than about 60 hours, or more than about 70 hours.
[0012] The methods of administration include administration of glyburide in a bolus injection to a subject, where the bolus injection is administered to the patient over a period of time of about 3 minutes or less; and where the bolus administration is followed by a continuous infusion of glyburide. In embodiments, the bolus is followed substantially immediately by the initiation of the continuous infusion (e.g., the continuous infusion commences less than one hour, or less than 30 minutes, or less than 10 minutes, or less than 5 minutes, or less than 3 minutes, or less than 2 minutes, or less than 1 minute, after the completion of the bolus administration).
[0013] In further embodiments, the methods of administration include administration of glyburide in a bolus injection to a subject, where the bolus injection is administered to the patient over a period of time of about 3 minutes or less; and where the bolus administration is followed by a continuous infusion of glyburide, or other drug, and by one or more further bolus injections of glyburide, or other drug. In embodiments, a second bolus injection is administered substantially immediately after the completion of the continuous infusion (e.g., the second bolus administration commences less than one hour, or less than 30 minutes, or less than 10 minutes, or less than 5 minutes, or less than 3 minutes, or less than 2 minutes, or less than 1 minute, after the completion of the continuous infusion). A second continuous infusion may begin substantially immediately after the completion of the second bolus injection, or a second continuous infusion may begin after an extended period of time after the completion of the first continuous infusion. In embodiments, a third bolus injection may begin after the completion of the second continuous infusion, and may begin either substantially immediately after the completion of the second continuous infusion, or may begin after an extended period of time after the completion of the second continuous infusion. Similarly, a fourth, or fifth, or other further bolus injection, and/or further continuous infusion may be administered, either substantially immediately, or after an extended period of time.
[0014] In further embodiments, multiple bolus injections of glyburide, or other drug, may be administered to a subject, without an intervening continuous infusion of glyburide, or other drug. In addition, in yet further embodiments, multiple continuous infusions of glyburide, or other drug, may be administered to a subject, without an intervening bolus injection of glyburide, or other drug. Such multiple bolus injections, or continuous infusions, or combinations thereof, may be administered substantially immediately after the previous injection or infusion, or may be administered after an extended period of time after the previous injection or infusion. A continuous infusion provides the administration of glyburide, or other drug, over an extended period of time, where an extended period of time may be a period of time measured in minutes (e.g., a few or several or many minutes), or measured in hours (e.g., a few or several or many hours), or measured in days (e.g., a few or several or many days).
[0015] In embodiments of the methods disclosed herein, the concentration of glyburide, or other drug, is higher in the formulation administered by bolus injection than the concentration of glyburide, or other drug, in the formulation administered by continuous infusion.
[0016] Applicant discloses herein that the blood levels of glyburide in human subjects typically reaches a peak level some hours following initiation of glyburide administration (e.g., after initiation of a bolus injection of glyburide followed by a continuous infusion of glyburide to the subject).
[0017] In a particular embodiment, Applicant discloses herein a 3 phase dosing regimen suitable for overcoming the dip in glyburide plasma levels which occurs several hours following the initiation of glyburide administration. In embodiments, such a 3 phase dosing regimen comprises:
[0018] (a) a bolus followed by a second bolus followed by a continuous infusion
[0019] (b) a bolus followed by an infusion at Rate 1 for A Hours followed by an infusion at Rate 2 for the remainder of the dosing period, where Rate 1>Rate 2 and A ranges from 1-20 hours. (“Rate 1” refers to a first rate, and “Rate 2” refers to a second rate, of administration of glyburide, or other drug, typically measured as, e.g., micrograms per hour (μg/hr).)
[0020] In a further embodiment, administration of glyburide, or other drug, is provided by 4 or more phases in the dosing regimen where multiple boluses and/or multiple infusion rates can be used. In such an embodiment, multiple rates and durations of administration are also provided (e.g., a Rate 1, Rate 2, Rate 3, Rate 4, etc.; and time periods A, B, C, etc.).
[0021] For example, Rate 1 may vary between about 15 μg/hr and about 200 to 300 μg/hr (e.g., between about 16.7 μg/hr and 250 μg/hr), and Rate 2 may vary between about 15 μg/hr and about 200 to 300 μg/hr (e.g., between 16.7 and 250 μg/hr). For example, time period A may vary from about 1 to about 10 hours, or from about 1 to about 20 hours. The total amount of glyburide, or other drug, delivered to the subject is the sum of the amount delivered by the bolus injection(s) plus the amount delivered during the continuous infusion. The amount of glyburide, or other drug, delivered to the subject during continuous infusion is calculated by multiplying the Rate times the time period (e.g., Rate 1×time period A). In embodiments, the daily dose (the dose over a 24 hour period, for example, the dose for the first 24 hours of glyburide administration) may be determined as follows: first Bolus+Rate 1×A+Rate 2×(24−A). In embodiments, the dose for the first 24 hours will be less than about 6 mg, or less than about 5 mg, or less than about 4 mg, and preferably may be less than about 3.5-4 mg, or less than about 3.13 mg or less than about 3 mg.
[0022] Thus, in embodiments, it is preferred that the total amount of glyburide administered to the subject per day be less than about 10 mg, or more preferably less than about 8 mg, or more preferably less than about 6 mg, and still more preferably less than about 5 mg, or yet still more preferably less than about 4 mg, or even more preferably less than about 3 mg of glyburide per day.
[0023] In a further embodiment, a bolus of about 125-150 μg, e.g., about 130 μg, of glyburide is administered to a subject followed by a continuous infusion of about 150-175 μg/hr, e.g., about 163 μg/hr, of glyburide for about 6 hours and then a further continuous infusion of about 100-125 μg/hr, e.g. about 112 μg/hr, glyburide is administered for about 50-75 hours, e.g. about 66 hours, for a total dosing period of about 72 hours. Thus, in this embodiment, the total daily dose of glyburide on Day 1, Day 2 and Day 3 may be about 3-4 mg, 2.5-3 mg, and 2.5-3 mg; e.g., about 3 mg, 2.5 mg, and 2.5 mg, respectively; or about 3.12 mg, 2.69 mg, and 2.69 mg respectively.
[0024] In a yet further embodiment, a bolus of glyburide, or other drug, is administered, and the bolus is followed by a continuous infusion of glyburide, or other drug, and then a further bolus or further boluses is/are administered, effective to raise early plasma levels of glyburide, or other drug, to desired levels. For instance, such an embodiment of the methods disclosed herein would include administration of a bolus of 125-150 μg, e.g., about 130 μg, glyburide followed by a continuous infusion of 100-125 μg/hr, e.g., about 112 μg/hr of glyburide, with a second glyburide bolus of 125-150 μg, e.g., about 130 μg, administered at hour 1, 2, or 3. In embodiments, further boluses may be administered as well.
[0025] In a further embodiment, Applicant discloses herein a method of administering glyburide, or other drug, to a subject, comprising: (a) a bolus administration of glyburide, or other drug; (b) a first continuous infusion administration of glyburide, or other drug after said bolus administration of glyburide, or other drug, wherein in said first continuous infusion glyburide, or other drug, is administered at a first rate of administration for a first period of time; and (c) a second continuous infusion administration of glyburide, or other drug after said first continuous infusion of glyburide, or other drug, wherein in said second continuous infusion glyburide, or other drug, is administered at a second rate of administration for a second period of time; whereby glyburide, or other drug, is administered to a subject effective to provide a substantially steady level of glyburide, or other drug, in the blood of said subject over a desired period of time. In a particular example of this further embodiment, the bolus is a bolus of about 125-150 μg, e.g., about 130 μg, of glyburide, and the bolus is followed by a continuous infusion of about 150-175 μg/hr, e.g., about 163 μg/hr of glyburide for about 6 hours; and then a further continuous infusion of about 100-125 μg/hr, e.g., about 112 μg/hr glyburide is administered to the subject for about 66 hours, for a total period of glyburide administration of about 72 hours. The total daily dose of glyburide on Day 1, Day 2 and Day 3 is thus about 3 mg, 2.5 mg, and 2.5 mg respectively; or about 3.12 mg, 2.69 mg, and 2.69 mg respectively.
[0026] Dosing of glyburide, or other drug, may be determined as a function of a subject's weight, or age, or gender, or height, or body surface area, or a combination of one or more of these, and the rates and bolus may be expressed as a function of one or more of these measures or methods of dosing.
[0027] The methods disclosed herein provide advantages for treating subjects in need of a fairly steady amount of glyburide introduced rapidly and maintained over an extended period of time (e.g., for up to about 72 hours). For example, where a subject has suffered a stroke, or traumatic brain or spinal cord injury, rapid achievement of therapeutic levels of glyburide may be important to a successful therapeutic outcome; in addition, maintenance of such therapeutic levels may likewise be important to a successful therapeutic outcome; however, it may also be important to prevent sustained levels of glyburide that are too high for the subject (e.g., to avoid hypoglycemia, extensive action of glyburide on the SUR2 receptor, or other complications). The experimental results and methods disclosed herein provide methods for achieving and maintaining therapeutic levels of glyburide rapidly, and over an extended period of time, and provide methods for avoiding excessive levels of glyburide, and so provide useful and advantageous treatments for subject in need of glyburide treatment. Subject in need of such treatments may include, for example, subjects suffering from acute stroke (ischemic and hemorrhagic), traumatic brain injury (TBI), spinal cord injury (SCI), myocardial infarction (MI), shock (including hemorrhagic shock), organ ischemia, and ventricular arrhythmias.
[0028] It will be understood that other drugs, in addition to glyburide, may be administered to a subject according to the methods disclosed herein. Administration of such other drugs may be particularly advantageous where the other drug has a pharmacokinetic profile similar to that of glyburide, as disclosed herein, or shares some of the pharmacokinetic properties of glyburide.
[0029] Applicants have discovered that it is preferable to avoid contact of a glyburide solution with polyvinyl chloride (PVC), as Applicants have discovered that the concentration of glyburide is reduced in glyburide solutions placed in contact with PVC. Applicants have invented methods to minimize such reductions of the concentration of glyburide in glyburide solutions placed in contact with PVC, and have invented methods of administration of glyburide which avoids contact of glyburide solutions with PVC. For example, Applicants have discovered that use of polyethylene bags, tubing, and filters, or polyethylene-coated bags and tubing, is preferred for the administration of glyburide solutions over the use of PVC-containing bags, tubing and filters.
[0030] Applicants disclose herein methods of preparing a container or device used in the administration of glyburide, e.g., in the administration of a therapeutic glyburide solution to a patient in need of such a therapeutic solution, are provided herein. Such methods of preparing a container or device, such as preparing a container, tube, and/or filter, comprise contacting a container, a tube, or a filter with a glyburide flushing solution. Such methods may include, for example, flushing a container, tube and/or filter with said glyburide flushing solution prior to its use in the administration of glyburide; the flushing may include flushing with at least about 50 mL, or at least about 70 mL, or more of the glyburide flushing solution. A glyburide flushing solution may have a glyburide concentration of at least about 2 μg/mL of glyburide, or about 2 μg/mL to about 8 μg/mL of glyburide, or about 5 to 6 μg/mL of glyburide, or greater concentrations of glyburide. Such methods include use of containers and devices, including bags, tubes, and filters which may have polyvinyl chloride (PVC) surfaces that may contact said glyburide therapeutic solution.
[0031] Applicants disclose herein methods of administering a glyburide therapeutic solution, wherein a container, a tube, and/or a filter is contacted (e.g., flushed) with a glyburide flushing solution prior to use of the container, tube, or filter in the administration of said glyburide therapeutic solution. The flushing may be flushing with at least 50 mL, or about 70 mL, or more, of the glyburide flushing solution. The glyburide flushing solution may have a glyburide concentration of at least about 2 μg/mL, or about 2 to about 8 μg/mL, or more of glyburide. The surfaces of containers, tubes, and/or a filters used for the administration of a glyburide therapeutic solution are preferably made of one or more materials other than polyvinyl chloride (PVC), for example, with polyethylene, in order to avoid contact of the glyburide therapeutic solution with PVC.
[0032] Applicants further provide methods of administering glyburide therapeutic solutions, in which a high concentration glyburide solution (e.g., at least about 10 μg/mL glyburide) is filtered and then diluted to provide a glyburide therapeutic solution (typically of lower glyburide concentration than the high concentration glyburide solution), and administering the glyburide therapeutic solution using delivery means made of one or more materials other than polyvinyl chloride (PVC), such as, e.g., polyethylene. A high concentration glyburide solution may have a glyburide concentration of between about 0.5 mg/mL glyburide and about 1 mg/mL glyburide, and may have a glyburide concentration of at least about 1 mg/mL glyburide. The glyburide therapeutic solution may be stored after filtering and prior to administration; in embodiments, the filtered glyburide therapeutic solution is stored within a container having an inner surface in contact with said glyburide therapeutic solution, wherein said container inner surface is made from one or more materials other than polyvinyl chloride (PVC), such as, e.g., polyethylene.
[0033] It will be understood that solutions discussed herein, such as glyburide solutions, and including without limitation, glyburide therapeutic solutions, glyburide flushing solutions, high concentration glyburide solutions, and other solutions may be filtered, and that such filtering is preferably sterile filtering, effective to provide sterile solutions suitable for administration to a patient. Such sterile filtration may include, for example, filtration through a sterile 0.2 micron filter, or other sterile filter suitable for use in providing sterile filtered solutions.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] FIG. 1 —Mean plasma glyburide concentrations for 0.4 mg/day glyburide.
[0035] FIG. 2 —Mean plasma glyburide concentrations for 3 mg/day glyburide.
[0036] FIG. 3 —Mean plasma glyburide concentrations for 6 mg/day glyburide.
[0037] FIG. 4 —Mean plasma glyburide concentrations for 10 mg/day glyburide.
[0038] FIG. 5 —Median blood glucose levels for placebo (0 mg/day glyburide), 0.4 mg/day glyburide, and 3 mg/day glyburide.
DETAILED DESCRIPTION OF THE INVENTION
Definitions
[0039] Terms used herein would be understood by those of skill in the art, and are to be understood in the manner accepted by those of skill in the art. Further definitions are provided herein to further explain and define terms.
[0040] As used herein, “patient,” “volunteer,” “subject” and the like, whether singular or plural, refers to human patients, volunteers, subjects, and the like.
[0041] As used herein, “ALT” is an acronym and means alanine transaminase.
[0042] As used herein, “AST” is an acronym and means aspartate transaminase.
[0043] As used herein, the term “dose” and its grammatical equivalents refer to the amount of glyburide administered to a subject. A dose may be described in terms of the grams of glyburide, or in terms of the weight/volume of diluent administered to the subject (e.g., milligrams per milliliter: mg/mL; micrograms per milliliter: μg/mL; nanograms per milliliter: ng/mL; etc.). The glyburide may be in water, such as sterile water for injection or other suitable water; in saline; in sugar solution; or in any pharmaceutically acceptable solution, which may include any other pharmaceutically acceptable drugs, excipients, osmoticants, diluents, buffers, preservatives, or other compounds or additives suitable for use in a fluid for injection.
[0044] As used here, the term “C max ” indicates the maximum concentration, in the blood, of glyburide.
[0045] As used here, the term “AUC” indicates area under the curve (the integral of the plasma concentration of the drug over an interval of time), and is used as a measure of the total amount of glyburide, or other drug, to which the subject is exposed by the drug administration.
[0046] As used here, the term “clearance” refers to the loss of glyburide, or other drug, from the blood of the patient. Clearance refers to a fraction of a (theoretical) volume of plasma from which the drug has been completely removed, per unit of time. Clearance may be measured, for example, in liters per hour (L/h), in milliters per minute (mL/min).
[0047] As used herein, the term “V d ” refers to volume of distribution, a term known to those of skill in the art, which refers to the volume (or potential volume) into which a drug, such as glyburide, would be distributed in a subject's body if it were distributed homogeneously (i.e., at the same concentration throughout that volume). Volume of distribution is typically measured in liters or liters per kilogram (L or L/kg).
[0048] As used herein, the term “Beta” provides a measure of the rate of transport of a drug, such as glyburide, into or out of the blood and tissue of a subject.
[0049] As used herein, the term “t 0 ” or “t zero ” refers to the initial time, from which further time measurements are taken. For example, where glyburide or other drug is administered to a subject, the time t 0 is the time at which administration commences. This initial time, the time t 0 , is the time at which administration commences whether the administration is bolus administration, continuous infusion, bolus administration followed by continuous infusion, administration with periods of time in which no drug, or different amounts of drug, are administered, or combinations of these.
[0050] As used herein, the term “t 1/2 ” refers to the half-life, typically measured in hours (h), minutes (min) or seconds (s), of a drug that has been administered to a subject. For example, the time to which the level (e.g., concentration) of glyburide or other drug (in the blood of a subject to which glyburide or other drug has been administered) drops to half its previous value is the t 1/2 for that subject.
[0051] As used herein, the term “t max ” refers to the time to which the level (typically concentration in the blood) of a drug that has been administered to a subject reaches its maximum level. For example, the time to which the level (e.g., concentration) of glyburide or other drug (in the blood of a subject to which glyburide or other drug has been administered) reaches its maximum after initial administration is the t max for that subject.
[0052] As used herein, the term “bolus” refers to administration of glyburide or other drug in a single injection that lasts for a relatively short period of time. As used herein, a bolus lasts for a period of time of about 3 minutes or less. A bolus injection may be an injection of a relatively high dose or concentration of drug.
[0053] As used herein, the term “continuous” refers to administration of glyburide or other drug in an injection that lasts for an extended period of time. A continuous injection may be an injection of a moderate dose or concentration of drug, or of a relatively low dose or concentration of drug. The term “infusion” is often used with continuous injection; as used herein, “continuous injection” and “continuous infusion” both equally refer to the intravenous administration of a drug, such as glyburide, to a patient over an extended period of time.
[0054] As used herein, an “extended period of time” refers to a period of time that is longer than one or two or three minutes. For example, an extended period of time may be a period of about 10 minutes, or about 20 minutes, or about 30 minutes, or about 40 minutes, or about 50 minutes, or more. In further examples, an extended period of time may be a period of about one hour, or about 2 hours, or about 3 hours, or about 4 hours, or about 5 hours, or about 6 hours, or about 7 hours, or about 8 hours, or about 9 hours, or more. In further examples, an extended period of time may be a period of about 10 hours, or about 12 hours, or about 15 hours, or about 20 hours, or about 25 hours, or about 30 hours, or about 40 hours, or about 44 hours, or about 48 hours, or more. It will be understood that an extended period of time may also be a period of about one day, or about two days, or about three days, or about four days, or about five days, or more.
[0055] As used herein, “substantially immediately” refers to a period of time that is less than about one hour, or less than 30 minutes, or less than 10 minutes, or less than 5 minutes, or less than 3 minutes, or less than 2 minutes, or less than 1 minute, after a previous event or time period.
[0056] As used herein, the term “placebo” refers to an ostensibly pharmaceutical formulation which lacks a pharmaceutically active ingredient, or lacks the particular pharmaceutical ingredient of interest in a particular study. In the experiments disclosed herein, “placebo” refers to a formulation identical to the formulation given to test subjects but lacking glyburide (e.g., including mannitol and NaOH, but not including glyburide). In general, a placebo may include inert compounds, and any pharmaceutically acceptable compound which may be found in a medicament, so long as it lacks a pharmaceutically active ingredient (as determined with respect to the pharmaceutical ingredient to which it is to be compared).
[0057] As used herein, the term “BG” refers to blood glucose.
[0058] As used herein, the term “PRN” means prescribed as needed.
[0059] In the following, time periods may be indicated as hours (e.g., H10 indicates at hour 10, or 10 hours following initiation of treatment) or days (e.g., D2 indicates day 2, or the second day following initiation of treatment).
[0060] The term “DSW” as used herein indicates water with 5 grams (g) of dextrose per 100 milliliters (mL) of water.
[0061] “RP-1127” refers to glyburide, or to glyburide formulations.
[0062] Applicant has performed experiments including the administration of glyburide and of placebo to subjects. Results of these experiments are disclosed in the following examples.
EXAMPLES
Glyburide Storage and Administration
[0063] Phase 1 Study
[0064] We determined through in-use stability testing that glyburide concentration is reduced by contact with polyvinyl chloride (PVC). For example, glyburide concentration is reduced when a glyburide-containing solution is passed through PVC tubing, or stored in a PVC bag. For example, we determined that glyburide concentration is reduced when glyburide-containing solutions are stored in PVC bags at glyburide concentrations below 10 μg/mL. One possible explanation is that glyburide adsorbs to PVC. At 10 μg/mL glyburide we were able to use a standard PVC bag (but not PVC tubing) with an acceptable amount of loss of glyburide (e.g., loss presumably due to adsorption to PVC).
[0065] We further discovered that glyburide concentration in a glyburide-containing solution is reduced by passage though a filter, such as through a 0.2 micron in-line filter. Thus in the human experiments in the application, e.g., for continuous infusion, glyburide was administered through low sorbing polyethylene (PE)-lined tubing with an inline filter that had been flushed according to a predetermined flushing protocol (see below) designed to ensure that the concentration of glyburide was reduced by no more than about 10%. For the lower doses, i.e. 0.4 mg/day, 3 mg/day and 6 mg/day (in which the glyburide concentration was less than 10 μg/mL), we used PVC-free bags. For the 10 mg/day dose (in which the glyburide concentration was 10 μg/mL), we used PVC bags.
[0066] For bolus injections, at all concentrations, we used a PALL Pharmassure 0.2 micron filter, HP1002 (Pall Life Sciences, 600 South Wagner Road, Ann Arbor, Mich. 48103) that had been flushed with the glyburide solution to be administered (ranging from about 2-3 μg/mL to about 50-75 μg/mL, e.g., ranging from about 2.5 μg/mL to about 60 μg/mL (for example, from 2.48 μg/mL to about 62.00 μg/mL) prior to use for injection.
[0067] Specifically:
The PVC free bag used was the B Braun EXCEL L8000 (B. Braun Medical Inc., 824 Twelfth Avenue, Bethlehem, Pa. 18018. The PVC bag used was the Viaflex 1,000 mL 2B1324X (Baxter, One Baxter Parkway, Deerfield, Ill. 60015-4625). The Carefusion 2260-0500 (CareFusion Corporation, 3750 Torrey View Court, San Diego, Calif. 92130) low sorbing administration set attached to an Carefusion 20350E (CareFusion Corporation, 3750 Torrey View Court, San Diego, Calif. 92130) low sorbing extension set with a 0.2 micron low protein binding filter was used for administering glyburide at 10 μg/mL concentration. The Carefusion 10010454 (CareFusion Corporation, 3750 Torrey View Court, San Diego, Calif. 92130) low sorbing administration set with built in 0.2 micron filter was used for administration of glyburide at concentrations below about 10 μg/mL. An Alaris Pump unit (CareFusion Corporation, 3750 Torrey View Court, San Diego, Calif. 92130) compatible with the above products was used.
[0000]
TABLE 1
Flushing Protocols for Infusion and Bolus Administration
Concentration
(μg/mL)
Equipment Used
Flushing with Glyburide Flushing Solution
Less than 10
B Braun EXCEL Bag
Prepare B Braun EXCEL bag with the required concentration.
(Infusion)
L8000, Carefusion
Flush so that 120 mL is released from the distal end.
10010454
Wait 15 minutes.
administration set
Flush tubing with 120 mL of solution.
with integrated filter
Wait 15 minutes
Flush tubing with 120 mL of solution.
Wait 15 minutes
Attach a newly mixed B Braun EXCEL bag of the same
concentration to the administration set, flush with 120 mL of
solution immediately prior to administration (i.e. bedside or
just before dosing).
Each 120 mL flush should take at least approximately 7-8
minutes.
10.0 (Infusion)
Viaflex PVC Bag,
Prime so that 10 mL is released from distal end.
Carefusion 2260-0500
Wait at least 10 minutes prior to use.
administration set plus
Flush with 30 mL immediately prior to administration.
Cardinal 20350E
extension set with
filter
All boluses
Standard BD syringe
Flush (the filter) with 21 mL.
(BD 1 Becton Drive
Expel a further 7 mL.
Franklin Lakes, NJ
Wait at least 15 minutes before use.
USA 07417) with
Prior to administration, expel 2 mL.
PALL 0.2 micron
filter HP1002
[0073] All components and flushing protocols were extensively tested beforehand to confirm a less than about 10% reduction in glyburide passing through the full chain of components. A glyburide flushing solution has a glyburide concentration of at least about 2 μg/mL, or about 2-8 μg/mL, or about 5-6 μg/mL, or about 10 μg/mL, or greater.
[0074] In all cases, the catheter used was a BD Nexiva catheter (BD, 1 Becton Drive, Franklin Lakes, N.J. USA 07417); the catheter was not flushed or tested.
[0075] Phase 2 Study
[0076] In the treatment of acute diseases, it is not typically desirable to spend time extensively flushing filters and tubing prior to administration, while a patient is awaiting treatment. Thus, since time is often of the essence in clinical situations, such as acute stroke, spinal cord injury, brain trauma, or other brain or nervous system injury or myocardial infarction or ventricular arrhythmias, delaying the administration of a drug to a patient while the pharmacy flushes tubing is not a desirable option. Furthermore, in urgent or emergency situations, it is preferable that a pharmacy have a simple set of instructions to prepare the drug.
[0077] Thus, although it may be possible to perform extensive flushing prior to storage of bags and tubing for later use, such a strategy is not preferred, since the stability of glyburide in such a situation has not been determined, and for sterility and other purposes, clinicians may prefer fresh bags and tubing to bags and tubing stored for long periods of time after flushing with glyburide, and pharmacies may prefer to have all its tubing and bags available for use for all drugs, without pre-treatment with glyburide.
[0078] We performed preclinical experiments to determine whether it was possible and practical to filter the concentrated reconstituted glyburide material (1 mg/mL) with a 0.2 micron filter (for example the Millex 0.22 um Durapore PVDF filter SLGV033RS or SLGVM33RS (Millipore, 290 Concord Road, Billerica, Mass. 01821), or the PALL 0.2 micron filter, HP1002) without undue loss of glyburide to the filter. In these experiments, the filtered material was diluted into a PVC-free bag (for example, the B Braun EXCEL L8000). In this protocol, the filtered glyburide solution in the PVC-free bag is ready for administration to a patient through unfiltered polyethylene lined tubing (for example the Carefusion 2260-0500 or Carefusion C20014) or through polyethylene lined tubing that is substantially PVC-free i.e. has only a short section of PVC, for example the Hospira 11993-78 (275 North Field Drive, Lake Forest, Ill. 60045). Note that prior to glyburide administration, the tubing may optionally be flushed with one flush of about 50 mL to about 75 mL (e.g., about 70 mL) of glyburide flushing solution (glyburide concentration of at least about 2 μg/mL, or about 2-8 μg/mL, or about 5-6 μg/mL, or about 10 μg/mL, or greater).
[0079] Glyburide has been administered to two patients with such a procedure. In one case, the SLGVM33RS syringe filter and the 2260-0500 administration set with 6×C20014 extension sets attached to it were used. In the other case, the SLGV033RS syringe filter and the Hospira 11993-78 administration set with 6×C20014 extension sets attached to it were used.
[0080] Pre-clinical testing shows that this procedure is effective to reduce the loss of glyburide from glyburide solutions.
[0081] We found that methods of filtering a glyburide solution that includes a glyburide concentration that is sufficiently high (e.g., at least about 10 μg/mL, preferably between about 0.5 and about 1 mg/mL and even more preferably about 1 mg/mL or greater) so that the filtering process does not significantly decrease the glyburide concentration, and then diluting the solution into a PVC-free bag to provide sufficient volume of solution to allow administration through a standard intravenous (IV) pump, then administering the solution through a filter-less polyethylene lined administration set (or a set that is mostly polyethylene lined with a short PVC section) are effective to provide clinically effective concentrations of glyburide for administration to a patient in need of glyburide treatment. Patients in need of glyburide treatment include patients suffering from stroke, such as acute stroke (ischemic and hemorrhagic), traumatic brain injury (TBI), spinal cord injury (SCI), myocardial infarction (MI), shock (including hemorrhagic shock), organ ischemia, ventricular arrhythmias, ischemic injury; hypoxia/ischemia; and other injuries, conditions, and disorders.
[0082] A BD catheter containing BD Vialon™ material was used for both patients (BD, 1 Becton Drive, Franklin Lakes, N.J. USA 07417); the catheter was not flushed or tested.
[0083] Pharmacokinetic Data
[0084] Healthy volunteers were enrolled into a Phase 1 study of RP-1127 titled “A Phase I Randomized, Double-blind, Placebo-controlled Study to Assess the Safety, Tolerability, and Pharmacokinetics of Escalating Doses of RP-1127 (Glyburide for Injection) in Normal Male and Female Volunteers” (Study 101). The primary objective of this study was to evaluate the safety and tolerability of different dose levels of RP-1127, administered as a bolus dose followed by a 3-day continuous infusion maintenance dose. The secondary objective was to assess the pharmacokinetics and pharmacodynamic responses to RP-1127. Plasma concentrations of glyburide and its two major active metabolites, M1 and M2, were measured.
[0085] Five groups of patients were dosed, totaling 26 patients on drug (8 at 17.3 μg bolus plus 0.4 mg/day, 16 at 130 μg bolus plus 3.0 mg/day, 1 at 260 μg bolus plus 6.0 mg/day and 1 at 433 μg bolus plus 10.0 mg/day) and 8 on placebo. Blood glucose was measured throughout the study, both to obtain pharmacodynamic information as well as for safety reasons. The dosing regimen was a bolus over 2 minutes followed by a continuous infusion for 72 hours.
[0000]
TABLE 2
Dose Levels in Phase 1
Bolus
Hourly
Day 1
Day 2 and
Dose
Dose
Dose
Day 3 Doses
Number of Patients
(μg)
(μg/hr)
(mg)
(mg)
RP-1127
Placebo
Total
17.3
16.7
0.417
0.4, 0.4
8
2
10
130.3
125.0
3.130
3.0, 3.0
16
4
20
260.0
250.0
6.260
6.0, 6.0
1
1
2
433.0
416.6
10.433
10.0, 10.0
1
1
2
Total
26
8
34
[0086] All plasma concentration data were analyzed by nonlinear regression, simultaneously incorporating drug behavior during and after the infusion. Results are provided in Table 3
[0087] Pharmacokinetic parameters of RP-1127 were independent of dose, weight, height, body surface area, gender and age.
[0000] TABLE 3 Pharmacokinetic Parameters of RP-1127 (Glyburide for Injection) from Study 101 Pharmacokinetic parameters of RP-1127 0.4 and 3.0 mg/day (Glyburide for Injection) (N = 26) T 1/2α (hr) 0.44 T 1/2β(hr) 3.31 V 1 Liters 6.0 Liters/kg 0.088 Liters/m 2 3.36 V d Liters 25.3 Liters/kg 0.38 Liters/m 2 14.3 Clearance mL/min 95 mL/min/kg 1.44 mL/min/m 2 54
As can be seen in Table 2, the pharmacokinetics of RP-1127 were generally consistent with those of other formulations of i.v. glyburide presented in Table 1. However, following the initial bolus loading dose, there was a drop in plasma glyburide concentration, with a minimum reached at a median of 1.25-1.5 hours after commencement of dosing. Plasma glyburide levels increased thereafter, and achieved steady state at approximately 8-20 hours following bolus administration. Steady state was maintained for the remainder of the infusion.
[0088] FIG. 1 shows the mean plasma glyburide concentrations measured in patients receiving 0.4 mg/day of glyburide.
[0089] The mean steady state glyburide concentration (C ss ) at 0.4 mg/day was 3.8 ng/mL, and the maximum glyburide concentration (C max ) was 7.2 ng/mL, which occurred at hour 72. Within one hour of treatment cessation mean glyburide plasma levels were reduced by 54% (from 4.4 ng/mL to 2.0 ng/mL). Glyburide plasma levels for 50% of the patients were below the limits of detection (0.5 ng/mL) by hour 76 and in 100% of patients by hour 96.
[0090] FIG. 2 shows the mean plasma glyburide concentrations measured in patients receiving 3 mg/day of glyburide.
[0091] For the 3 mg/day dose, mean C ss was 25.3 ng/mL and C max (of all individual subjects) was 50.7 ng/mL, which occurred in one patient at hour 48. Within 1 hour of cessation of dosing, mean glyburide plasma levels were reduced by 57% (from 27.3 ng/mL to 11.9 ng/mL). Glyburide plasma levels were below the limits of detection in 50% of the subjects by hour 84 and in 100% of patients by hour 96.
[0092] FIG. 3 shows the mean plasma glyburide concentrations measured in patients receiving 6 mg/day of glyburide. Dosing was stopped early, at around 32 hours due to the hypoglycemic effect of the drug.
[0093] FIG. 4 shows the mean plasma glyburide concentrations measured in patients receiving 10 mg/day of glyburide. Dosing was stopped early, at around 24 hours due to the hypoglycemic effect of the drug.
Blood Glucose/Hypoglycemia Data
[0094] FIG. 5 shows the median blood glucose levels in patients receiving placebo (no glyburide), 0.4 mg/day glyburide, and 3 mg/day glyburide. As can be seen, the 0.4 mg/day dose had a very minor but visible effect on BG and the 3.0 mg/day dose had a more pronounced effect, without hypoglycemia (prolonged BG<70 mg/dL or signs/symptoms of hypoglycemia e.g. shakiness, anxiety, nervousness, palpitations, tachycardia, sweating, feeling of warmth, coldness, clamminess, dilated pupils, feeling of numbness “pins and needles”, hunger, nausea, vomiting, abdominal discomfort, headache, impaired judgment, fatigue, weakness, apathy, lethargy, confusion, amnesia, dizziness, delirium, blurred vision, double vision, difficulty speaking, slurred speech, and in more severe cases seizures and coma).
[0095] From H0 to H8 the single subject receiving 250 μg bolus plus 6 mg/day of intravenous glyburide experienced a gradual lowering of blood glucose levels, however these remained above 70 mg/dL. Between approximately H8 and H12, blood glucose levels dropped lower, and ranged from 59 to 72 mg/dL. At approximately H13.3, the Subject intermittently displayed signs of hypoglycemia in the form of sweating (diaphoresis) and hunger. These symptoms lasted 15 minutes. Blood glucose measurements at H14 and H 15 were within normal ranges, however from approximately H16 to H29 blood glucose fluctuated between 49 and 134 mg/dL. During this period the subject was treated with food PRN but experienced intermittent symptoms of hypoglycemia and at times felt shaky, lightheaded with tunnel vision, and clammy. Subject felt “shaky” and was diaphoretic while eating lunch, and so at approximately H29, the subject was treated with IV dextrose (10%) at a rate of 100 cc/hour, following which blood glucose remained in the range 64-123 mg/dL. Dosing with study drug was suspended at H32 as a result of continued clinical signs of hypoglycemia. The D10 rate was decreased at HR34 to 50 cc/hr and was replaced with IV D5W at approximately HR 36. IV D5W was continued until H48, at which time the patient had been consistently normoglycemic for approximately 7 hours.
[0096] Total calories consumed by mouth and IV on day 2 by subject 402 was 4309. The percentage of Kcals: Protein=11%; Carbs=66%; fat=23%.
[0097] During this episode, subject had classic symptoms of hypoglycemia but was always alert, oriented and conversant. Subject was also able to consume all food and liquids provided.
[0098] Dosing was stopped early, at around 32 hours due to the hypoglycemic effect of the drug.
[0099] At H12 the BG was <70 mg/dL (68 mg/dL) and the glyburide plasma level was 64 ng/mL.
[0100] The subject receiving 433 μg bolus plus 10 mg/day glyburide experienced blood glucose levels in the range 63 mg/dL-81 mg/dL from HI to H8, which reduced in the 52-53 mg/dL range during HI2-H22. The subject was treated PRN throughout this time with the following: glucose gel, yogurt, apple juice, a bagel and peanut butter. At hour 22, the morning serum glucose below 50 mg/dL at which point dosing was suspended. During this episode, subject had classic symptoms of hypoglycemia but was always alert, oriented and conversant. Subject was also able to consume all food and liquids provided.
[0101] Dosing was stopped early, at around 24 hours due to the hypoglycemic effect of the drug.
[0102] At hour 2, BG was below 70 mg/dL and the glyburide plasma level was 57.94 ng/mL.
Discussion
[0103] Applicant believes that the results disclosed herein provide, for the first time, the results of experiments in which glyburide has been administered for more than a few hours and that plasma levels of glyburide have been recorded. Garrel et al. (1987) administered a 1 mg i.v. bolus dose, followed by 0.3 mg/h for 17 hours, to six subjects with type I diabetes (insulin-dependent diabetes mellitus (IDDM)); the total dose was 6.1 mg glyburide. However, no PK analysis was performed.
[0104] Thus, it is believed that no-one has previously observed or described the effects with glyburide described herein.
[0105] Applicant notes that severe hypoglycemia occurred at 6 mg/day of glyburide and 10 mg/day of glyburide delivered as continuous infusions (250 μg/hr and 17 μg/hr). It appears that glyburide levels of above about 50 ng/mL, and probably in the range about 58-64 ng/mL or above are sufficient to cause hypoglycemia that is clinically relevant and/or refractory to treatment. It was surprisingly difficult to treat the hypoglycemia caused by the continuous infusion at high doses (6 and 10 mg/day) while maintaining glyburide administration. It is preferred to avoid hypoglycemia, for example, when treating a subject suffering from acute stroke (ischemic and hemorrhagic), traumatic brain injury (TBI), spinal cord injury (SCI), myocardial infarction (MI), shock (including hemorrhagic shock), organ ischemia, and ventricular arrhythmias. Accordingly, plasma levels of glyburide of less than about 50 ng/mL are preferred plasma levels, providing the therapeutic benefits of glyburide while avoiding most or all of the deleterious side effects that higher concentrations might cause (e.g., hypoglycemia). Preferentially, glyburide levels of about 10 ng/mL to about 20 ng/mL, or of about 20 ng/mL to about 30 ng/mL, or of approximately 25 ng/mL should be targeted, it being understood that by doing so, a wide concentration range (up to approximately 50 ng/mL at peak) of glyburide in the blood stream can be expected, at least for short periods of time.
[0106] An important point to note is that in acute conditions where intravenous glyburide is likely to be administered e.g. acute stroke (ischemic and hemorrhagic), traumatic brain injury (TBI), spinal cord injury (SCI), myocardial infarction (MI), shock, organ ischemia, and ventricular arrhythmias, the time window during which injury, cell death, or other cell, tissue, or organ damage is maximal is likely to be within about 0-4, or about 0-6, or about 0-12, or about 0-24 hours. Thus attaining the desired glyburide plasma levels quickly is vital. Furthermore in these indications, hypoglycemia can have negative effects, thus it is preferably to treat patients with doses of intravenous glyburide that will not cause extended or clinically significant hypoglycemia.
[0107] Furthermore, the difficulty experienced in treating hypoglycemia with oral and iv glucose indicates that the concept of increasing glyburide doses into the hypoglycemic range and then cotreating with glucose may not work. It has been known for some time that carbohydrate “loading” can cause substantial elevations in serum ALT and AST that generally become evident within 1 week of the diet change (Irwi et al 1969, Porikos et al. 1983, Purkins et al. 2003, Kechagieas et al. 2008). Carbohydrate induced aminotransferase elevations are frequently associated with substantial increases in serum triglycerides, probably resulting from increased synthesis of triglyceride in the liver. Deposition of glycogen in hepatocytes is also associated with elevations in serum aminotransferases and this has been described in poorly controlled diabetes (Sayuk et al. 2007, Chatila et al. 1996). Glycogen deposition in the liver could occur quite quickly and may therefore account, at least in part, for aminotransferase elevations observed with carbohydrate loading. It also seems likely that the hyperinsulinemic effect of glyburide would exacerbate the carbohydrate uptake and conversion to glycogen by the liver.
[0108] There is evidence from our study outlined in the above rationale i.e. that continued administration of large amount of carbohydrate in parallel to significant increases in insulin release leads to transient elevations in ALT and AST—this was experienced by the subject receiving 6 mg/day glyburide, who was treated with 4,309 calories over 24 hours and two thirds of this was in the form of carbohydrates. This is a very substantial carbohydrate load, far exceeding the daily carbohydrate intake employed in prior healthy volunteer studies that have demonstrated aminotransferase elevations.
[0109] While these types of ALT and AST elevations caused by carbohydrate loading are not considered dangerous in normal healthy patients, they are not preferable, especially in labile patients such as ones suffering from acute conditions and should be avoided.
REFERENCES
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Chatila R, West. Hepatomegaly and abnormal liver tests due to glycogenosis in adults with diabetes. Medicine (Baltimore) 75:327-333, 1996.
Garrel, D. R., Picq, R., Bajard, L., Harfouche, M., Tourniaire, J. 1987. Acute effect of glyburide on insulin sensitivity in Type I diabetic patients. J. Clin. Endocrinol. Metab. 65:896-900.
Groop, L., Luzi, L., Melander, A., Groop, P.-H., Ratheiser, K., Simonson, D. C., and DeFronzo, R. A. 1987. Different effects of glyburide and glipizide on insulin secretion and hepatic glucose production in normal and NIDDM subjects. Diabet. 36: 1320-1328.
Groop L C, Barzilai N, Ratheiser K, Luzi L, Wahlin-Boll E, Melander A, DeFronzo R A. Dose-dependent effects of glyburide on insulin secretion and glucose uptake in humans. Diabetes Care. 1991 August; 14(8):724-7.
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Jonsson, A., Chan, J. C., Rydberg, T., Vaaler, S., Hallengren, B., Cockram, C. S., Critchley, J. A., and Melander, A. 2000. Pharmacodynamics and pharmacokinetics of intravenous glibenclamide in Caucasian and Chinese patients with type-2 diabetes. Eur. J. Clin. Pharmacol. 55(10):721-727.
Kechagieas S, Emersson A, Dahlqvist 0, et al. Fast food based hyper-alimentation can induce rapid and profound elevation in serum alanine aminotransferase in healthy subjects. Gut 35 57(5):649-54, 2008.
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Porikos K P, Van Italie T B. Diet induced changes in serum transaminase and triglycreride levels in healthy adult men. Am J Med 75:624-30, 1983.
Rydberg, T., Jonsson, A., Roder, M., and Melander, A. 1994. Hypoglycemic activity of glyburide (glibenclamide) metabolites in humans. Diabet. Care. 17:1026-1030.
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The present disclosure is drawn to a method of administering glyburide intravenously to a subject over a period of time as a first bolus administration of glyburide; a second bolus administration of glyburide, after the first bolus; and a first continuous infusion administration of glyburide, wherein the first continuous infusion is administered at a first rate of administration for a first period of time, after the second bolus administration of glyburide.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit under 35 U.S.C. § 119 of provisional patent application No. 60/647,346 filed on Jan. 27, 2005 and entitled “Combination Scooter/backpack,” the entire contents of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] The presented invention involves an apparatus for article carrying. The apparatus is generally a wheeled article carrier with the capacity to convert into a rider-operated scooter. Additionally, the article carrying function of the apparatus is not lost when the scooter is in use.
[0003] Presently, students and travelers of all ages employ back or shoulder carried devices to carry their belongings. Supporting these heavy loads, especially over extended periods of time, has been shown to promote muscular and skeletal back injuries. This occurs most commonly while walking long distances, for example, a child's walk to and from school or a tourist's path to and from a train station. The present invention allows those distances to be traversed without any stress on the back, therefore saving the child, or user, from injury. Currently this product exists as two separate products, a backpack and a scooter, but they cannot be used together in the beneficial manner this invention proposes. Combining the equipment therefore creates a unique solution to an everyday problem.
SUMMARY OF INVENTION
[0004] The present invention is an article carrier with several modes of transportation provided in it. The carrier takes the form of a traditional flexible container with a strap positioned on a single face. Opposite said face is attached a rigid two-piece frame which makes contact along the vertical height of the carrier and bends around underneath providing support. Inserted into the frame is a telescoping steering column assembly that runs along the vertical height of the carrier and is positioned in the center of said frame. The steering column assembly attaches to a single pivoting wheel at the bottom of the frame and a handlebar at the top. The handlebar can be raised above and lowered to the top face of the carrier while the wheel remains stationary. Only when in the raised position, the handlebar exerts a torque on the wheel through the steering column providing steering control. Attached opposite the carrier on the frame is a board that pivots around a hinge at the base of the frame. The board is linked to the handlebar in such a way that raising the handlebar rotates the board around this hinge and extends outwardly in a horizontal fashion. Similarly, lowering the handlebar lifts the board back to its vertically oriented position against the face of the plastic frame. A second immovable wheel is embedded into the far end of the board enabling rolling upon two wheels to occur when the board is extended. A braking mechanism makes contact with a portion of this rear wheel. A cover piece is attached along its edge to a horizontal face of the carrier adjacent to either face containing the straps or frame. This cover piece circumferentially surrounds the carrier in either direction and fastens to its opposite face. Once fastened, the cover piece secures the shoulder straps to the carrier or the pivoting board to the frame, creating an aesthetic, safe, and organized appearance.
[0005] With these features in place, the carrier has two suggested modes of transportation, while others are possible. The first mode is to place the strap around a wearer's shoulder and place the bag on the back in a traditional backpack position. The handlebar is in the lowered position, adjacent the top of the frame. The board is in the vertical position, parallel to the frame, and the fabric is wrapped around it, securing it to the frame away from the wearer. This provides a source of comfort since the rigid components of the frame assembly are not in contact with the wearer's back.
[0006] The second mode is a riding mode. The handlebar is in the raised position and the board is linked mechanically to extend parallel to the ground. The handlebar is connected to the front caster through the steering column and provides steering control. The cover piece is wrapped around the shoulder straps securing them to the carrier. The user stands with one or both feet upon the board and their weight is distributed amongst the two casters. The article carrier is deposed in front of the user on the opposite side of the frame, secured and balanced about the front wheel by the weight of the user. The user can then push the board with a foot upon the ground and roll to the destination while steering with the handlebar.
[0007] These features function together to provide: a spacious flexible container with a strap, a comfortably distributed load when device is upon wearer's back, a balanced two-wheeled ride upon a scooter, a weightless and stress-free carrying of personal belongings, a faster than walking means of locomotion, a practical and simple steering mechanism, a selectively separable board and bag that prevents the wearer or rider from misplacing the scooter or bag respectively, convenient and continual access to both said bag and scooter simultaneously, an organized aesthetic appearance during use in either mode, and a unique and expedited bag to scooter conversion process.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The invention can be further described by the following FIGUREs, whereby:
[0009] FIGS. 1, 2 , and 3 are isometric views of a scooter/backpack according to the present invention.
[0010] FIGS. 4A, 4B , and 4 C are front views of each steering column member.
[0011] FIGS. 5, 6 , 7 , 8 , and 9 are front views of the steering column assembly with the plastic frame cut away.
[0012] FIG. 10 is an isometric view showing the periphery of steering column members.
[0013] FIG. 11 is a rear view of the plastic frame and lower steering column members.
[0014] FIG. 12 is a rear view as in FIG. 11 .
[0015] FIG. 13 is a cutaway view of the plastic frame and middle steering column member.
[0016] FIG. 14A is an isometric view of the frame sections and handlebar.
[0017] FIG. 14B is an exploded view of FIG. 14A .
[0018] FIG. 15 is a side view of the combination scooter/backpack.
[0019] FIG. 16 is a side view as in FIG. 16 .
[0020] FIGS. 17, 18 , and 19 are cutaway views of the plastic frame and hinge
[0021] FIG. 20 is a front view of the board lock.
[0022] FIGS. 21, 22 , and 23 are isometric views as in FIGS. 1, 2 , and 3 .
[0023] FIGS. 24A, 24B , and 24 C are cross-sectional views of each steering column member.
DETAILED DESCRIPTION
[0024] The preferred embodiment of the combination scooter/backpack 1 can be seen in FIG. 1 . The combination scooter/backpack 1 is shown in its backpack mode. The bag 3 has two padded shoulder straps 7 attached in conventional backpack locations. In the preferred embodiment means are provided to adjust length of each strap to accommodate varying sizes of wearer. An edge of flap 2 is sown vertically upon the face of bag 3 , parallel to the L-shaped plastic frame section 4 . It secures to the opposite face of bag 3 through the interaction of male 5 and female 6 clips of the type common to the backpack industry. The flap 2 is capable of wrapping around said scooter/backpack 1 in either direction, thereby securing either the shoulder straps 7 to the bag 3 for scooter mode, or the board 9 to the I-shaped plastic frame section 8 for backpack mode. The flap 2 assists to retain board 9 in a manageable position so as to avoid contact with passers by or the like while creating an organized and aesthetically pleasing appearance. Flap 2 is preferably made of a flexible yet durable material such as nylon fabric, yet other materials may be used.
[0025] As seen in FIG. 2 , the male clips 5 have been released from female clips 6 and flap 2 has been uncurled. The L-shaped plastic frame section 4 functions to support the bag 3 and its contents. L-shaped plastic frame section 4 mates along plastic frame seam 10 with the I-shaped plastic frame section 8 through fasteners 16 . Preferably, frame sections 4 and 8 are constructed from medium density plastics for strength and weight considerations. In accordance with the backpack mode of the present invention, board 9 lies vertically against I-shaped plastic frame section 8 while a handlebar 11 is in its lowered position. The front wheel 12 is underneath the plastic frame sections and is connected to the handlebar 11 as part of steering column assembly 14 , not shown. The steering column assembly 14 stands between the plastic frame sections 4 and 8 . Attached to the far end of board 9 is rear wheel 13 . Also shown in FIG. 2 , are lid 41 and lid fastener 43 . In preferred embodiments of the invention, lid 41 is the portion of bag 3 that is adjacent a closable opening. Lid fastener 43 serves to release lid 41 when access to the contents of bag 3 is desired and close lid 41 to secure belongings for transport or security reasons. Lid fastener 43 could be construed as, but not limited to, such commonly understood fastener types as buttons, zippers, snaps, etc.
[0026] FIG. 3 shows flap 2 surrounding shoulder straps 7 during scooter mode.
[0027] Handlebar 11 is raised to its elevated position exposing inner column 20 , which is a portion of steering column assembly 14 . Board 9 is lowered and ready to be stepped upon by the user. Board 9 is connected to the I-shaped plastic frame 8 through hinge assembly 15 . Hinge assembly 15 consists of hinge pin 28 , board plate 29 , and frame plate 39 . Additionally, board 9 is connected to the steering column assembly 14 through linkage arms 17 . This enables the raising and lowering of handlebar 11 to rotate board 9 between stowed and extended positions. This feature relies on the mechanism of steering column assembly 14 as will be seen, and is extremely convenient for the user. Effectively, the user can stow or extend the board 9 without crouching or stooping down to manipulate the board by hand, thereby avoiding any possible back discomfort due to such positions.
[0028] FIGS. 4A, 4B , and 4 C detail the steering column components of the steering column assembly 14 . The outer column 18 , middle column 19 , and inner column 20 stand concentrically in a telescoping fashion. As seen in FIG. 24A , outer column 18 has a rectangular outer perimeter and circular inner diameter to accommodate the middle column 19 . Thickness 21 is provided around outer column 18 to limit the vertical travel of said column within the plastic frame sections. Linkage arms 17 are connected to the bottom of the outer column 18 through pivot connections, as will be shown in more detail later. Outer column 18 also contains openings 25 to accept lower button set 24 . As can be seen in FIGS. 4B and 24B , middle column 19 stands the tallest among the three columns. It has circular outer and inner perimeters, the outer small enough to slide within the outer column 18 and an inner large enough to accommodate the inner column 20 . The front wheel 12 is connected to the bottom of the middle cylinder through front forks 22 in a standard axle configuration. Middle column 19 contains one set of openings 26 and one set of slots 27 to accept upper and lower button sets 23 and 24 .
[0029] In FIG. 4C the inner column member 20 is shown. Inner column member 20 stands inside the middle column member 19 and travels up and down with movement of the handlebar 11 . As seen in FIG. 24C , the inner and outer perimeters of inner column 20 are circular. To retain certain vertical positions within middle column 19 the inner column member 20 employs upper and lower button sets 23 and 24 . Upper and lower button sets 23 and 24 are generally of rectangular shape and extend outwards engaging the openings 25 and 26 and slots 27 of outer and middle columns 18 and 19 . Button sets 23 and 24 are spring loaded and require depression by the user to sink into the inner column 20 effectively disengaging them from the corresponding openings or slots. While positioned inside middle column 19 , only one button set can extend at a time. As will be shown, lower button set 24 is used to engage both outer column 18 and middle column 19 to the inner column 20 , while upper button set 23 engages openings 26 for transmitting torque from the handlebar 11 to the front wheel 12 during steering.
[0030] Furthermore, it can be shown that a variety of different shapes, dimensions, quantities of, and placement positions on said steering column assembly 14 for said button sets 23 and 24 and openings 25 and 26 and slot 27 are advantageous over one another for reasons of steering mechanics, varying sizes of riders, ease of manufacturing, load distribution, overall aesthetics, etc. It is therefore not the intention of the proposed invention to limit itself in any one of these configurations, rather to simply establish a means to perform necessary functions of the invention.
[0031] The following FIGUREs demonstrate the arrangement of column members 18 , 19 , and 20 . In FIG. 5 , the steering column assembly 14 is shown in its entirety while in its closed position known as position 1 . The combination scooter/backpack 1 is in the backpack mode of use and is to be converted to scooter mode. The handlebar 11 is in the it's lowest position against the top of the plastic frame sections. The upper button set 23 of inner column member 20 are depressed and inside the middle column 19 unable to extend. Lower button set 24 , however, is extended completely through slots 27 of the middle column 19 and openings 25 of outer column 18 , thereby linking the impending vertical travel of the outer and inner column members 18 and 20 . Rotational movement of the handlebar is prevented due to the square cross section of outer column 18 constrained inside plastic frame sections 4 and 8 .
[0032] In FIG. 6 , the combination scooter/backpack 1 is in Position 2 . The handlebar 11 has been lifted a small distance causing outer column member 18 to travel upwards the same amount. Middle column 19 remains unaffected because lower buttons 24 travel within slots 27 . Preferably, slot 27 is slightly longer than the initial raise of handlebar 11 . As will be shown, lifting outer column 18 will cause board 9 to rotate by means of linkage arms 17 . This prepares the combination scooter/backpack 1 for scooter mode, and allows user access to the lower button set 24 , which was previously covered by board 9 .
[0033] In FIG. 7 , the user has depressed lower button set 24 far enough to sink into middle column 19 to allow additional vertical travel of handlebar 11 .
[0034] In FIG. 8 , the combination scooter/backpack 1 is in Position 4 . Handlebar 11 has been lifted to the height for steering use in scooter mode. Lower button set 24 is depressed and contained inside middle column 19 . Upper button set 23 , previously depressed and inside middle column 19 , are now aligned with openings 26 .
[0035] In FIG. 9 , the combination scooter/backpack 1 is in Position 5 . Upper button set 23 extends under the push of its spring through the openings 26 of middle column 19 . Torque can now be effectively transmitted from handlebar 11 to front wheel 12 during steering. The steering assembly 14 is now configured for scooter mode.
[0036] FIGS. 5-9 show the conversion process from backpack to scooter modes of the combination scooter/backpack 1 . Performing this process in reverse will successfully convert combination scooter/backpack 1 from scooter mode to backpack. The user would dismount from board 9 and depress upper button set 23 into openings 26 of middle column 19 . Then, lowering handlebar 11 a first distance will allow lower button set 24 to extend through slots 27 and openings 25 and engage middle and outer columns 19 and 20 . A further lowering of handlebar 11 will lower outer column 18 and cause linkage arms to rotate around hinge pin 28 . Through board plate 29 , board 9 rotates upwardly to the vertical position and is prepared for flap 2 to surround and secure it to I-shaped plastic frame 8 . Consequently, the combination scooter/backpack 1 is in backpack mode, and ready to be placed upon the user.
[0037] FIG. 10 shows the additional mating connection between the middle and inner columns 19 and 20 . In addition to upper button set 23 , inner and middle columns 19 and 20 are conjoined by flange 30 and groove 31 . Flange 30 and groove 31 partially run the distance between upper and lower button sets 23 and 24 , acting to assist the upper button set 23 in transmitting torque during steering and restrain the handlebar during backpack mode as well as other advantages.
[0038] Turning now to FIG. 11 , the I-shaped plastic frame section 8 is shown. The frame has a perimeter section 32 . It should be noted that perimeter section 32 can be any thickness, internal or external, necessary to support a variety of rider sizes under a variety of riding connections. Perimeter section 32 defines a rectangular shape for plastic frame sections 4 and 8 . Attached to perimeter section 32 are spokes 33 used to support upper stopper 34 and lower stopper 35 . Upper and lower stoppers 34 and 35 function to limit the vertical travel of outer column 18 by contacting thickness 21 . Referring to FIG. 9 , the outer column 18 is in its lowest position and the combination scooter/backpack 1 is in backpack mode. Furthermore, it should be noted that features 32 , 33 , 34 , and 35 of I-shaped plastic frame section 8 are mirrored in the vertical length of L-shaped plastic frame member 4 , thereby completing the two halves of plastic frame necessary to surround steering column assembly 14 .
[0039] Continuing to FIG. 12 , the outer column 18 has been raised a slight amount through its connection to the inner column 20 and handlebar 11 . The thickness 21 contacts the upper stopper 34 thereby preventing further raising of the handlebar, indicating to the user that the board 9 is in the extended position. Additionally, openings 25 and lower button set 24 are exposed to the user, allowing depression of the buttons to advance the conversion process. Once lower button set 24 is depressed beneath middle column 19 the handlebar 11 and inner column 20 can be raised further. It should be noted that middle column 19 and front wheel 12 have remained motionless during the process between FIGS. 9 and 10 .
[0040] FIG. 13 details the connection between the middle column 19 and perimeter section 32 . The connection is made through a bearing 36 . In the preferred embodiment, two tapered roller bearings of typical industry standard should be mounted in an indirect configuration. The bearings 36 is paramount in its function to transmit the rider's weight from the board 9 , through plastic frame sections 4 and 8 , and onto the middle column 19 and front wheel 12 . In the preferred embodiment, bearings 36 are placed in the perimeter section 32 . In alternative embodiments, additional bearings 36 may be placed in other locations, such as the upper stopper 34 to aid in the transmission of weight between the plastic frame sections 4 and 8 and middle column 19 . It should be noted that other means for connection between middle column 19 and frame sections 4 and 8 are possible. Roller bearings are only presented as a preferred means.
[0041] FIGS. 14A and 18B highlight the connection between the steering column assembly 14 and plastic frame sections 4 and 8 . As can be seen, I-shaped plastic frame section 8 fastens through fasteners 16 to the complementarily shaped L-shaped plastic frame section 4 . Also included on L-shaped plastic frame section 4 are feet 42 . Feet 42 function to provide support for loads carried in bag 3 . In the preferred embodiment they are of rectangular cross-section but any shape may be implemented to achieve desired load-carrying performance. Additionally, FIG. 14B shows the connection between middle column 19 of steering column assembly 14 and plastic frame sections 4 and 8 . Bearings 36 surround and secure middle column 19 to the perimeter section 32 and/or upper stopper 34 of plastic frame sections 4 and 8 . This attachment will allow rotation of middle column 19 for steering, yet support against the axial and radial thrust loads that will result from user manipulation of handlebar 11 . It should be noted that features 12 , 32 , 33 , 34 , and 35 have been omitted from FIGS. 14A and 14B for clarity.
[0042] As shown in FIG. 15 , the combination scooter/backpack is in the backpack mode. The board 9 is in the vertical position and the outer column 18 is in the lowest position. Linkage arms 17 are attached to the bottom of outer column 18 . Linkage arms 17 are themselves a pivot joint connection between two arms, upper arms 37 and lower arms 38 . Upper arms 37 are attached to the outer column 18 through a pivot connection and to lower arms 38 through a pivot connection. On their opposite end, lower arms 38 are fixedly connected to hinge pin 28 thereby linking vertical movement of outer column 18 and rotational movement of hinge pin 28 . Upper and lower arms 37 and 38 are shown shaped in rectangular fashion, but other lengths, widths, and curvatures are possible to achieve desired rotational performance of board 9 .
[0043] FIG. 16 shows linkage arms 17 while the combination scooter backpack is in the scooter mode. The outer column 18 is in the raised position and board 9 is lowered for riding use. The outer column 18 has been raised and upper arms 37 have straightened and pulled on lower arms 38 causing rotation about hinge pin 28 . As demonstrated, linkage arms 17 function to rotate board 9 not only with the raising, but lowering of handlebar 11 .
[0044] FIG. 17 is shown for purposes of highlighting the interaction between linkage arms 17 , hinge pin 28 , board hinge plate 29 , and frame hinge plate 39 . Sections of plastic frame sections 4 and 8 and outer column 18 have been removed for clarity. Outer column 18 is inside lower stopper 35 . Upper arms 37 are pivotally connected to the bottom of outer column 18 . Studs 40 are provided on outer column 18 to limit the arcuate path of upper arm 37 during the conversion process. Lower arm 38 is pivotally connected to upper arm 37 and fixedly connected to hinge pin 28 . Thereby, lower arm 38 transmits the vertical displacement of upper arm 37 to rotation of hinge pin 28 . Board hinge plate 29 is fixedly connected to hinge pin 28 , thereby linking the angular rotation of hinge pin 28 to the rotation of board hinge plate 29 and board 9 . Frame hinge plate 39 is fixedly attached along its face to the perimeter section 32 and pivotally connected to hinge pin 28 . This allows hinge pin 28 to rotate independent of frame hinge plate 39 . As can be seen in FIG. 17 , the combination scooter backpack 1 is in backpack mode. Board hinge plate 29 and board 9 lay vertically against I-shaped plastic frame 8 . The steering column assembly 14 is in Position 1 .
[0045] FIG. 18 shows the previous components in transition between Positions 1 and 2 of steering column assembly 14 . Outer column 18 has been pulled up by its connection to handlebar 11 through lower button set 24 . Lower arm 38 has been pulled up by upper arm 37 causing rotation of hinge pin 28 and board hinge plate 29 .
[0046] FIG. 19 shows outer column 18 and related hinge components in Position 2 .
[0047] Outer column 18 has reached its maximum height and board 9 has reached its extended position, reaching outwardly from the plastic frame.
[0048] While the board 9 is secured to I-shaped plastic frame section 8 through flap 2 in backpack mode, board 9 requires an additional locking mechanism to secure it in the extended position during scooter mode. FIG. 20 shows a preferred embodiment of the mechanism used to lock board 9 in the extended position during the scooter mode of usage. Board lock 44 consists of two parallel arms 46 connected by a bridging member 47 . FIGS. 21, 22 , and 23 show the preferred embodiment of board lock 44 and its position on board 9 . Board lock 44 is attached to board 9 pivotally at board lock joint 45 . FIG. 21 shows the combination scooter/backpack 1 in backpack mode. Board lock 44 lies parallel to board 9 , secured against plastic frame 8 . In FIG. 22 , handlebar 11 has been raised and caused outer column 18 to rotate board 9 to the extended position. Board lock 44 lies against board 9 ready for rotation. FIG. 23 shows board lock 44 rotated upwardly and around to press against frame section 8 . In this position, board lock 44 resists any torque around hinge pin 28 that may occur from the user pulling on handlebar 11 during scooter mode. In the preferred embodiment, unique feet may be incorporated onto parallel arms 46 to better fit against I-shaped plastic frame 8 . When converting from scooter mode to backpack, the process outlined in FIGS. 21-23 should be reversed. Board lock 44 should be rotated away and down from plastic frame section 8 and stowed against board 9 , prepared for the rotation of board 9 to the vertical position.
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The combination scooter/backpack is an article carrying device with the capacity to be converted into a wheeled land vehicle, and therefore has two modes of usage. The article carrying device resembles a conventional backpack with two straps positioned to be placed over the user's shoulders, entitled backpack mode. The wheeled land vehicle functions as a popular collapsible scooter, two wheels mounted upon a board member with propulsion means provided by user's contact with the ground, entitled scooter mode. A horizontal handlebar is positioned at the top of the combination and serves to steer the front wheel during scooter mode. Conversion between backpack mode and scooter mode is accomplished with the raising and lowering of said handlebar and the manipulation of releasable fasteners and latches. In both backpack and scooter modes, a cover circumferentially surrounds the combination scooter/backpack to secure and protect components that are not in use.
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BACKGROUND OF THE INVENTION
This invention relates to a method of forming fluoride glass fiber preforms for optical communication.
The application of fluoride glass fibers is expected in the field of optical communication, for example, the fiber optical amplifier operating at 1.3 μm-band, the optical waveguide and the fiber laser because its light transmittance region is wide and the transmittance of infrared region therethrough is particularly high as compared with oxide glass fibers and plastic fibers. However, there are some drawbacks of fluoride glass in the preparation of optical fiber preforms. That is, fluoride glass tends to react with water in the atmosphere and to be crystallized.
There are some usual methods of forming fluoride glass fiber preforms. For example, JP-A-57-191240 discloses a build-in casting method. In this method, firstly, a fluoride glass melt for the cladding is poured into a mold which comprises a plurality of separable elongate portions. Then, an unsolidified central portion of the fluoride glass melt is allowed to flow out. After that, another fluoride glass melt for the core is poured into the central portion of the mold.
JP-A-58-125630 discloses a rotational casting method. In this method, firstly, a fluoride glass melt for the cladding is poured into a rotating mold. Then, an unsolidified central portion of the fluoride glass melt is allowed to flow out. After that, another fluoride glass melt for the core is poured into the central portion of the rotating mold. However, the above-mentioned two methods have the following drawbacks.
It is needed to repeat casting in a relatively short time. Bubbles and striae tend to be incorporated into the glass because it is necessary to pour a core glass melt into a central opening of a cladding glass tube. Furthermore, the cladding glass is reheated and thus tends to be crystallized by pouring a large amount of the core glass melt into the cladding glass tube which has started to solidify.
JP-A-3-183630 discloses an extrusion method in which a solidified core glass body and a solidified cladding glass body are mated with each other at their ground surfaces and the mated glass body is extruded.
JP-A-63-190739 discloses a rod-in-tube method. In this method, a solidified core glass rod is inserted into a solidified cladding glass tube so as to form a preform. After that, the preform is melted, and then the melted preform is drawn.
The above-mentioned extrusion method and rod-in-tube method have the following drawbacks.
In the methods, at first, the core glass and the cladding glass are separately prepared. Therefore, the incorporation of impurities into the glass tends to be suppressed. However, a high gain can not be obtained due to irregular interface between the core and the cladding. Furthermore, it is difficult to prepare a preform for a single-mode optical fiber and in particular to have a diametral ratio of cladding to core more than about 15:1.
JP-A-63-11535 discloses a suction method in which a cladding glass melt is poured into a mould which is formed at its lower end with a sink for the cladding glass melt, and then a core glass melt is poured on the cladding glass melt. During cooling of the cladding glass melt, a void space is produced at the center of the cladding glass body due to contraction of the cladding glass in the sink. Accordingly, the void space is filled with the core glass melt so that a preform having a core-cladding structure is prepared. However, this method has the following drawbacks.
The core diameter does not become constant because the central void space for the core is produced due to only contraction of the cladding glass in the sink. Furthermore, it is difficult to obtain a long preform.
JP-A-4-31333 discloses a method in which a preform made by the rod-in-tube method or the suction method is drawn so as to obtain a core having a uniform diameter, and then the outer surface of a cladding is ground so as to obtain the cladding having a uniform diameter. However, in this method, crystallization at the interface between the core and the cladding tends to occur, thereby lowering strength of the preform.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide an improved method of forming a fluoride glass fiber preform, which is free of the above-mentioned drawbacks.
According to the present invention, there is provided a method of forming a fiber glass preform, comprising the steps of:
(a) pouring a cladding glass into a mold;
(b) pouring a core glass on a flat horizontal upper surface of said cladding glass so as to form a united glass body having said core glass and said cladding glass under a condition that viscosity of said cladding glass and viscosity of said core glass are adjusted to certain predetermined values respectively so that said core glass is separated from and placed on said cladding glass;
(c) cooling said united glass body to solidify the same so that said cladding glass is deformed by contraction thereof so as to produce a depression at a top middle portion thereof and that said core glass is deformed so as to form a projected portion thereof to fill said depression therewith;
(d) separating said united glass body into an upper portion and a lower portion which comprises said projected portion of said core glass; and
(e) extruding said lower portion of said united glass body so as to form the fiber glass preform.
In the present invention, due to the combination of casting and extrusion process, it is not necessary to repeat casting in a relatively short time.
The incorporation of bubbles and stride into the glass does not tend to occur because the core glass is poured on a flat horizontal upper surface of the cladding glass melt.
The amount of core glass can be decreased to the amount corresponding to the volume of contraction of the cladding glass. Therefore, crystallization of the cladding glass due to reheating of the same does not tend to occur.
A preform having an arbitrary diametral ratio of cladding to core can be obtained by controlling the shape of the depression caused by contraction of the cladding glass.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 to 6 are sectional views showing a sequential process of forming a fluoride glass fiber preform in accordance with the present invention;
FIG. 7 is a view similar to FIG. 3, but showing another embodiment in which a small amount of a cladding glass melt is used;
FIGS. 8 and 9 are views similar to FIGS. 2 and 3, but showing still another embodiment in which a disklike plate having a center hole is used; and
FIGS. 10 to 13 are enlarged sectional views showing projected portions of a core glass melt with which depressions of the cladding glass are filled.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to FIGS. 1 to 6, a method of forming a fluoride glass fiber preform according to the present invention will be described in the following.
Firstly, a cladding glass melt in a mold is cooled to a certain predetermined temperature so as to suppress flow therein. Under this condition, as is seen from FIG. 1, a certain predetermined amount of a core glass melt 10 having a certain predetermined temperature is gently poured on the cladding glass melt 12 so as to form a united cylindrical glass body and not to disturb an upper surface of the cladding glass melt. With this, as is seen from FIG. 2, this cylindrical glass body has the core glass melt phase 10 and the cladding glass melt phase 12 which are separated from each other. Then, the cylindrical glass body is allowed to cool down. After cooling, as is seen from FIG. 3, the cladding glass 12 deforms by contraction so as to produce a depression 14 at a top middle portion thereof, and the core glass 10 also deforms so as to fill the depression 14 with a projected portion 16 of the core glass 10. It should be noted that the cylindrical glass body having a shape shown in FIG. 3 is not suitable for the preparation of the glass fiber preform. Therefore, according to the present invention, as is seen from FIG. 4, an upper portion 18 of the cylindrical glass body is removed so as to leave the projected portion 16 of the core glass 10 in a lower portion 19. Then, as is seen from FIGS. 5 and 6, the lower portion 19 of the cylindrical glass body is set in an extruder and extruded by a usual extrusion method. With this, a preform having a uniform core diameter (i.e. a preform defined between dotted lines) is obtained. Extrusion is conducted at a temperature ranging from sag temperature to the crystallization temperature, and preferably at a temperature at which viscosity of the glass is from 10 9 to 10 6 poises. If the temperature is lower than sag temperature, it is difficult to extrude the glass body. If the temperature is higher than the crystallization temperature, the preform will have crystals therein. This causes scattering loss.
In the present invention, the size and shape of the projected portion 16 of the core glass 10 can controlled by the amount of the cladding glass melt to be poured into the mold. For example, as is seen from FIG. 7, when the amount of the cladding glass melt is decreased, the size of the projected portion 16 of the core glass 10 is decreased due to reduction in contraction volume of the cladding glass 12. The size and shape of the projected portion 16 of the core glass 10 can be controlled by the usage of an optional disklike plate having a center hole, too. As is seen from FIGS. 8 and 9, if the core glass melt 10 is poured on the disklike plate 20 which is placed on the cladding glass melt 12, and then the cylindrical glass body is cooled, the depression 14 of the cladding glass 12 and the projected portion 16 of the core glass 10 are formed in such a manner that the size and shape of the projected portion 16 is controlled by the size of the center hole 20a of the disklike plate 20, as illustrated. For example, if the amount of the cladding glass melt is constant, the projected portion 16 becomes more elongate in shape by decreasing the size of the center hole 20a of the disklike plate 20. It is desired that the projected portion has an elongate shape so as to obtain a long preform having a constant core diameter. Thus, the size and shape of the projected portion 16 of the core glass 10 is arbitrarily controlled or designed by the amount of the cladding glass melt 12, viscosity of the cladding glass melt 12, cooling speed of the cladding glass melt 12, the size of the center hole 20a of the disklike plate 20 or the combination of these factors.
In the present invention, it is necessary that the core glass melt phase 10 is separated from the cladding glass melt phase 12, as is illustrated in FIG. 2, when the core glass melt 10 is poured on the cladding glass melt 12. For this purpose, it is necessary that, upon pouring, viscosity of the cladding glass melt is in the range from 10 4 to 10 2 poises and that viscosity of the core glass melt is in the range from 10 2 to 1 poise. If viscosity of the cladding glass melt is greater than 10 4 poises upon pouring, the cladding glass is reheated so as to speed up the crystal growth speed. Therefore, it is possible that the cladding glass is crystallized. If viscosity of the core glass melt is greater than 10 2 poises, it becomes to difficult to conduct casting. If viscosity of the core glass melt is less than 1 poise, bubbles tend to be incorporated into the glass.
In the following, the present invention will be described with reference to nonlimitative examples.
EXAMPLE 1
To prepare the core glass (fluoride glass), a first batch of glass composition was prepared by mixing 53 mol % of ZrF 4 , 20 mol % of BaF 2 , 4 mol % of LaF 3 , 3 mol % of AlF 3 and 20 mol % of NaF.
To prepare the cladding glass (fluoride glass), a second batch of glass composition was prepared by mixing 10 mol % of ZrF 4 , 40 mol % of HfF 4 , 19 mol % of BaF 2 , 3 mol % of LaF 3 , 2 mol % of YF 3 , 4 mol % of AlF 3 and 22 mol % of NaF.
50 g of the first batch and 160 g of the second batch were respectively put into first and second crucibles which are made of amorphous carbon and have a diameter of 35 mm and a height of 65 mm, and melted in the atmosphere of argon gas at a temperature of 850° C. for 2 hr and then at a temperature of 650° C. for 30 min.
After that, the second crucible containing the second batch was put on a stainless plate heated at a temperature of 150° C. In about 7 min, the first crucible containing the first batch was put on the stainless plate. In about 10 min, about 10 g of the core glass melt was poured on the cladding glass melt so as to form a first cylindrical glass body. In 1 min, the second crucible containing the cladding glass melt and the core glass melt was put into an annealing furnace heated at a temperature of 270° C. so as to conduct annealing to room temperature. Then, as is seen from FIG. 4, an upper portion 18 of the first cylindrical glass body was removed. Thus, a lower portion 19 of the first cylindrical glass body, or a second cylindrical glass body having a diameter of 33 mm, a height of 35 mm and the projected portion 16 of the core glass, which is shown in FIG. 10, was obtained. As is seen from FIG. 5, the second cylindrical glass body was set in an extruder having a die hole diameter of 10 mm, and then extruded with a certain pressure at a temperature of 285° C. With this, as is seen from FIG. 6, a cylindrical rod having a diameter of 11 mm and a longitudinal length of 300 mm was obtained. From this rod, a preform having a constant core glass diameter of 1 mm, a cladding glass diameter of 11 mm and a longitudinal length of 150 mm was taken.
EXAMPLE 2
A method according to Example 1 was repeated except that a first batch of glass composition for a core fluoride glass was prepared by mixing 49 mol % of ZrF 4 , 25% of BaF 2 , 4 mol % of LaF 3 , 2 mol % of YF 3 , 2 mol % of AlF 3 and 18 mol % of LiF, so as to obtain a second cylindrical glass body having a diameter of 33 mm, a height of 35 mm and a projected portion of the core glass therein which is shown in FIG. 10.
Then, the second cylindrical glass body was extruded with an extruder having a die hole diameter of 5 mm. With this, a preform having a cladding diameter of 5.5 mm, a core diameter of 0.5 mm and a longitudinal length of 330 mm was obtained.
EXAMPLE 3
A method according to Example 1 was repeated except that a disklike plate having a center hole was placed on the second batch put in the second crucible, and then the first and second batches were separately melted under a condition according to Example 1. Then, the second crucible was put on a stainless plate heated at a temperature of 150° C. In about 6 min, the first crucible was put on the stainless plate. In about 9 min, about 10 g of the core glass melt was poured on the cladding glass melt so as to form a first cylindrical glass body. In 1 min, the second crucible containing the core glass melt and the cladding glass melt was annealed in accordance with Example 1. Then, as is seen from FIG. 4, an upper portion 18 of the cylindrical glass body was removed. Thus, a lower portion of the first cylindrical glass body, or a second cylindrical glass body having a diameter of 33 mm, a height of 35 mm and the projected portion 16 of the core glass therein witch is shown in FIG. 11 was obtained. The second cylindrical glass body was extruded in accordance with a method of Example 1. With this, a preform having a cladding diameter of 11 mm, a core diameter of 1.2 mm and a longitudinal length of 150 mm was obtained.
EXAMPLE 4
A method according to Example 3 was repeated so as to prepare a second cylindrical glass body having a diameter of 33 mm and a height of 35 mm. Then, the upper side of the second cylindrical glass body was ground by a thickness of 3 mm. The thus obtained cylindrical glass body had a diameter of 33 mm and a height of 32 mm and the projected portion 16 of the core glass therein which is shown in FIG. 12. This cylindrical glass body was extruded in accordance with a method of Example 1. With this, the obtained preform had a cladding diameter of 11 mm, a core diameter of 0.2 mm and a longitudinal length of 150 mm.
EXAMPLE 5
To prepare the core glass (fluoride glass), a first batch of glass composition was prepared by mixing 50 mol % of ZrF 4 , 20 mol % of BaF 2 , 5 mol % of PbF 2 , 4 mol % of LaF 3 , 2 mol % of YF 3 , 2 mol % of AlF 3 and 17 mol % of LiF.
To prepare the cladding glass (fluoride glass), a second batch of glass composition was prepared in accordance with Example 1.
50 g of the first batch and 160 g of the second batch were respectively put into first and second crucibles and melted in accordance with Example 1.
After that, the second crucible containing the second batch was put on a stainless plate heated at a temperature of 150° C. Then, argon gas was uniformly applied to a side wall of the second crucible so as to forcibly cool the cladding glass. In about 4 min, the first crucible containing the first batch was put on the stainless plate. In about 7 min, about 15 g of the core glass melt was poured on the cladding glass melt so as to form a first cylindrical glass body. Then, argon gas was applied to the side wall of the second crucible for 30 sec. Then, the second crucible was annealed in accordance with Example 1. Then, as is seen from FIG. 4, an upper portion of the first cylindrical glass body was removed. Thus, a lower portion of the first cylindrical glass body, or a second glass body had the projected portion of the core glass therein which is shown in FIG. 13. The second cylindrical glass body was extruded in accordance with Example 1. With this, a cylindrical rod having a diameter of 11 mm and a longitudinal length of 300 mm was obtained. From this rod, a preform having a constant core diameter of 0.7 mm, a cladding glass diameter of 11 mm and a longitudinal length of 180 mm was taken.
EVALUATION TEST
In each of Examples 1-5, the obtained preform was observed with an optical microscope. With this, impurities such as crystals and bubbles were not found. In each of Examples 1-5, He--Ne laser beam was applied to the core glass. With this, scattered light at the interface between the core glass and the cladding glass was not observed with naked eyes.
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A method of forming a fiber glass preform includes the steps of: (a) pouring a cladding glass into a mold; (b) pouring a core glass on a flat horizontal upper surface of the cladding glass so as to form a united glass body having the core glass and the cladding glass under a condition that viscosity of the cladding glass and viscosity of the core glass are adjusted to certain predetermined values respectively so that the core glass is separated from and placed on the cladding glass; (c) cooling the united glass body to solidify the same so that the cladding glass is deformed by contraction thereof so as to produce a depression at a top middle portion thereof and that the core glass is deformed so as to form a projected portion thereof to fill the depression therewith; (d) separating the united glass body into an upper portion and a lower portion comprising the projected portion of the core glass; and (e) extruding the lower portion of the united glass body so as to form the fiber glass preform.
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BACKGROUND OF THE INVENTION
This relates to methods and apparatus in a cantilevered frame part of a press section and/or wire section of a paper machine in which a cantilevered beam attached between the side frames of the paper machine is pre-tensioned by applying a predetermined force in a downward direction of the projecting part of the cantilevered beam.
It is known in the prior art to provide cantilevered beams as part of the paper machine frame. The cantilevered beams extend in the transverse direction of the paper machine and are arranged in a manner such that at the service side of the paper machine, intermediate pieces situated between the beam and the frame are openable by means of power units. When opened, the intermediate pieces provide an opening through which closed fabric loops of the paper machine can be inserted and positioned around the rolls and cross beams in connection with the replacement of the fabrics. In a manner known in the prior art, the projecting parts of the cantilevered beams which are situated at the other side of the paper machine, i.e., the operation side of the paper machine opposite from the service side at which the openable intermediate pieces are situated, are fixed to the ceiling, wall or floor of the paper machine hall, and most commonly are fastened to projecting parts of the wall of the paper machine hall by means of massive threaded members. The threaded fastening members function to support the cantilevered beam when the intermediate pieces on the service side of the machine frame are opened.
The known manner of fastening the projecting part of the cantilevered beam involves certain drawbacks resulting from the fact that the fastening members are under tension at all times. For this reason, oscillations or vibrations spread from the paper machine frame through the fastening members to the wall construction of the paper machine hall which, among other things, significantly increases the noise level in the paper machine hall.
Another drawback of conventional tensioning fastening arrangements is that the large forces applied by them to the cantilevered beams may cause the long frame beams to deform. This can adversely affect, for example, the parallel alignment of the axles of the various paper machine rolls.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide new and improved methods and apparatus in a cantilevered frame part of a paper machine which will avoid the drawbacks discussed above.
Briefly, in accordance with the present invention, this object, among others, is obtained by providing a method wherein the pre-tensioning of a cantilevered beam is produced by power means, preferably a hydraulic power unit, which applies a downwardly directed pre-tensioning force on the projecting part of the cantilevered beam when the service side of the paper machine frame is opened, such as for replacement of press fabrics or the like, and wherein the pre-tensioning is released after the replacement of the press fabrics or the like has been carried out and the service side of the paper machine frame has been closed or is closeable.
According to the invention, the above-stated object, among others, is also obtained by providing apparatus which, in accordance with a first embodiment, comprises a loading arm connected to the end of the projecting part of the cantilevered beam by means of an articulation shaft, a hydraulic cylinder or the like having one end arranged to act upon the loading arm, and the other end being attached to the upper side of the projecting part of the cantilevered beam. The loading arm is attached to one end of a pull bar by an articulation shaft or the like while the other end of the pull bar is attached to a stationary counter-member and the loading arm is linked to the end of the projecting part of the cantilevered beam.
In a second embodiment, apparatus in accordance with the invention comprises a draw cylinder having a piston which can be withdrawn into the cylinder by adjusting the pressure of a pressure medium to produce pre-tensioning of the beam. The draw cylinder is attached at its top side to the outer end of the projecting part of the cantilevered beam by articulation pins or the like while the bottom side of the draw cylinder is attached to a stationary counter-member, preferably a projecting part of the wall of the paper machine hall.
In a third embodiment, apparatus in accordance with the invention comprises a hydraulic lifting cylinder fitted on or in connection with the top side of the projecting part of the cantilevered beam. The hydraulically displaceable lifting part of the hydraulic cylinder rests against a stationary counter-member, preferably through the intermediate of a press bolster.
In accordance with the invention, the pre-tensioning of the cantilevered beam can be released during normal operation of the paper machine, i.e., when the service side of the machine frame is closed. The pre-tensioning is applied to the cantilevered beam when the service side of the paper machine is opened by removing the intermediate piece or pieces so that any deformation or sag of the cantilevered beam under its own weight will not become unduly large.
DESCRIPTION OF THE DRAWINGS
A more complete appreciation of the present invention and many of the attendant advantages thereof will be readily understood by reference to the following detailed description of preferred embodiments, to which the invention is not limited, in conjunction with the accompanying drawings in which:
FIG. A is a schematic front elevation view in partial section of a cantilevered beam of a frame part of a paper machine and illustrating a pre-tensioning fastening arrangement in accordance with the prior art;
FIG. 1 is a front elevation view in partial section of a first embodiment of apparatus in accordance with the invention in conjunction with a projecting part of a cantilevered beam;
FIG. 2 is a detail view of apparatus illustrated in FIG. 1 on an enlarged scale and illustrating various pivot points and dimensions of a lever mechanism comprising a part of the apparatus;
FIG. 3 is a side elevation view of the apparatus illustrated in FIG. 2 in the longitudinal direction of the cantilevered beam from outside the beam;
FIG. 4 is a view similar to FIG. 1 illustrating another embodiment of apparatus in accordance with the invention: and
FIG. 5 is a view similar to FIGS. 1 and 4 illustrating still another embodiment of apparatus in accordance with the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings wherein like reference characters designate identical or corresponding parts throughout the several views, and more particularly to FIG. A, a conventional paper machine frame comprises a transverse cantilevered beam 10 extending between opposed side frames of the paper machine, namely, between the service-side side frame 11 and the operation-side side frame 12. In a manner known in the prior art, the projecting part 10a of the cantilevered beam 10 at the operation side of the frame is fixed to a projecting part 17 of a wall 16 of the paper machine hall. In particular, the projecting part 10 a of cantilevered beam 10 is connected to the projecting part 17 of wall 16 by means of a draw bar 18 that extends through an opening 20 formed through the end of the projecting part 10 a of beam 10. The draw bar 18 passes into a box bolster 19 that bears against the flat bottom side of the projecting wall part 17 and is mounted in the paper machine hall in the machine direction. The ends of the draw bar 18 are threaded and nuts 21 are threadedly fastened on the top end of the draw bar to bear against the top surface of the projecting part 10 a of beam 10. Similarly, nuts 22 are threadedly fastened on the lower end of the draw bar 18 and bear against the bottom surface of the bolster 19. The nuts 21 and 22 are generally permanently tightened in the illustrated positions to provide a suitable permanent support and pre-tensioning for the beam by virtue of the force F applied to the beam by the nuts 21. On the other hand, the projecting part of the beam applies an equal and opposite force to the bar 18 so that the draw bar 18 is subjected to considerable tensile strain. The bar 18 and nuts 21, 22 are relatively massive and robust members so that it is not practical, and usually not possible, to open the tension fastening arrangement such, for example, as during replacement of a press felt.
Still referring to FIG. A, a press roll 13 of the press section is mounted on the side frames 11 and 12 by its bearings and axle journals 13a. The levers and cylinders for loading the press roll 13 are schematically illustrated at 14. Openable intermediate pieces 15 (one shown) are provided as part of the service-side side frame 11. When it is desired to replace a closed loop of press fabric, the intermediate pieces 15 are opened to provide a free space through which a new closed loop of press fabric is inserted and located around the press and guide rolls whereupon the intermediate pieces are closed and the side frame 11 locked. The tensioning fastening means 17, 18, 19, 21, 22 of the projecting part 10a of beam 10 is not opened during the replacement operation. Rather, the cantilevered beam 10 ha a certain pre-tension at all times resulting from the permanent force F to reduce the sag of the end of the beam 10 which is proximate to the service-side side frame 11 and to facilitate opening of intermediate pieces 15.
The principles of operation of a first embodiment of apparatus in accordance with the invention will now be described with reference to FIG. 2. A hydraulic cylinder 23 is attached to the upper side of the projecting part 10a of cantilevered beam 10 by a bracket 25. A piston rod 24 of the hydraulic cylinder is linked to the end of one arm 27a of a bellcrank lever 27 at point C by pin 26. Bellcrank lever 27 is pivotally connected to the projecting beam part 10a at point A by pin 29 and bracket 28. The lower arm 27b of the bellcrank lever 27 is linked to a draw bar 30 at point B by pin 33 and bracket 37. When the point B is held fixed and when the draw bar 30 is loaded by a tensile force F, the point A and the entire projecting part 10a of cantilevered beam 10 to which point A is fixed, attempts to turn downwardly so that the main body of beam 10 supported by the side frame 12 attempts to turn upwardly. In this manner, the desired pre-tensioning of the beam 10 is produced. The magnitude of the pre-tensioning can be adjusted by adjusting the position of a limiting screw 34. The required pre-tensioning force F can be set by adjusting the ratio of the dimensions S and M of the bellcrank lever 27 while the size of the loading cylinder 23 and the loading pressure P from pressure source 39 can be maintained constant. As an example, the dimension S may be 300 mm. while the dimension M may be 1000 mm. After the intermediate frame pieces 15 have been opened and the felts replaced, the pre-tensioning of the beam 10 can be released in accordance with the method of the invention by depressurizing the hydraulic cylinder 23 and by pivoting the bellcrank lever 27 against the limiting stop 35 at point E.
The principle of operation and the construction of the embodiment of the invention shown in FIG. 1 are similar to that described above. Referring to FIG. 1, the lower arm 27b of the bellcrank lever 27 is attached to the draw bar 30 by means of an articulated joint 33'. The draw bar 30 passes through a box bolster 31 mounted in the paper machine hall in the machine direction. The draw bar 30 is fixed by means of nuts 32 threaded over its lower end which bear against the lower surface of the box bolster 31. The embodiment of FIG. 2 differs from that of FIG. 1 in that the upper end of the draw bar 30 in the embodiment of FIG. 2 is connected to a forked bracket 37 by means of a nut 36, the bracket 37 being attached to the lower arm 27b of the bellcrank lever 27 at point B by means of an articulation shaft or pin 33. In other respects, the construction of the embodiment illustrated in FIG. 1 is the same as that illustrated in FIG. 2.
Another embodiment of the invention is illustrated in FIG. 4. In this embodiment, a piston rod 41 of a draw cylinder 40 is connected to the outer end of the projecting part 10a of cantilevered beam 10 by means of brackets 47 and an articulation pin 42. At its bottom end, the draw cylinder 40 is connected to the draw bar 44 by an articulation pin 43. The draw bar 44 passes through the box bolster 45 which is mounted in the machine hall in the machine direction. The draw bar 44 transfers the lifting force to the box bolster 45 by means of nuts 46. The flange 48 at the top end of the box bolster 45 bears against the lower flat side of the projecting part 17 of wall 16. When a certain pressure P is introduced into the draw cylinder 40 from a pressure source 39, the piston rod 41 retracts into the draw cylinder and tends to pull the projecting beam part 10a downwardly, whereby at a certain time, appropriate pre-tensioning is provided in cantilevered beam 10.
Referring now to FIG. 5, another embodiment of apparatus in accordance with the invention includes a lifting cylinder or jack 50 fixed to the top side of the projecting part 10a of cantilevered beam 10 while the lifting part 51 of the lifting cylinder 50 bears against the lower flange 55 of the box bolster 52 mounted on the machine hall in the machine direction. The upper flange 53 of box bolster 52 bears against the flat lower side of the projecting part 17 of wall 16. Upon pressurizing the lifting cylinder 50 with a pressure P from the pressure source 39, the lifting part or piston 51 pushes upwardly against the box bolster whereupon the pre-tension required in connection with the replacement of a felt or the like is provided in cantilevered beam 10. The pre-tension can also be released in a easy manner as will be understood.
It is a feature of the method of the invention that the power units 23, 40 and 50 are depressurized so that the cantilevered beam is not pre-tensioned during normal operation of the paper machine. When a felt or the like is to be replaced and the intermediate pieces 15 of the side frame 11 are opened by means of cranes or the like, a pre-tension of an appropriate magnitude is maintained in the cantilevered beam 10. The magnitude of the pre-tensioning is chosen so that the sag of the end of the cantilevered beam 10 situated at the service-side side frame 11 does not become unduly large. As a rule, the magnitude of the pressure P applied to the power units 23, 40, 50 when pre-tensioning is required does not require any regulation. Rather, and the magnitude of the pre-tensioning force F and magnitude of the deflection of the projecting part 10a of beam 10 in the downward direction are determined by mechanical devices. For example, in accordance with the embodiments of FIGS. 1 and 2, the limiting screw 34 provided at the end of the lower arm 27b of the bellcrank lever 27 can be adjustable to regulate the magnitude of the pre-tensioning force and deflection of the projecting beam part.
Obviously, numerous modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the claims appended hereto, the invention may be practiced otherwise than as specifically disclosed herein.
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Method and apparatus in a cantilevered frame part of a press section and/or wire section of a paper machine in which a cantilevered beam extending between the side frames of the machine is pre-tensioned by applying a force on the cantilevered or projecting part of the beam. The pre-tensioning is produced by a power device, preferably a hydraulic power unit, which produces a downwardly directed pre-tensioning force on the projecting part of the cantilevered beam. The pre-tensioning is applied prior to the replacement of press fabrics or an equivalent operation, and is released after the fabric replacement has been carried out and the side frame at the service side of the machine has been closed or is closeable.
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This application is a divisional of U.S. application Ser. No. 541,272, field 10/12/83 now issued as U.S. Pat. No. 4,530,866.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a rubber roller for spinning and manufacturing method thereof. More particularly it relates to a rubber roller for spinning improved in durability with its specific cylindrical rubber cot force-fitted on a metal core for roller without using any adhesive and the manufacturing method thereof.
2. Description of the Prior Art
Hitherto a widely used rubber roller for spinning has been what comprises a rubber cot adhesive-bonded to and around a metal roller core. Such an adhesive-bonded rubber roller, however, has a drawback of the bondage being gradually lost as the roller is used prolongedly to possibly result eventually in of the rubber layer coming off. The force-fitting method, in which a rubber cot with its bore somewhat smaller than the outer diameter of a metal roller core is mechanically fitted on the latter's outer periphery, is, therefore, being increasingly applied for manufacture of rubber rollers. A rubber roller of this force-fitted type, which is easy to assemble as it is, however, has a drawback of the rubber cot coming off the core rather easily due to insufficient fitting.
Meanwhile, there has been made a proposal to cover the bore of a rubber cot with a textile layer and have it adhesive-bonded to the surface of a metal roller core. The rubber roller so made is superior in bondage attainable to its counterpart without textile lining, i.e. with simple rubber cot, but with it, too, the rubber cot tends to come off in prolonged use, leaving something to be desired about durability.
In another prior art (U.S. Pat. No. 2,597,858) it is proposed to make the rubber cot consisting of three layers, namely the outer rubber layer, intermediate rubber layer and inner rubber layer, and embed glass cords in the intermediate rubber layer for reinforcement. Since this rubber roller is made up of three rubber layers, however, it is difficult to make especially when its rubber cover is thin, as thin as 2-3 mm. Further, since glass cords are embedded in the intermediate rubber layer, expansibility of the inner rubber layer is reduced thereby, this making it difficult to fit the cot on the metal roller core.
According to the present invention, which is aimed at overcoming the defects of the conventional rubber rollers for spinning, fitting of a rubber cot on a metal roller core in the manufacture of a rubber roller is facilitated, and the rubber roller manufactured is definitely improved in durability with the cot being safer from coming off or peeling, being thus suited for use in spinning.
SUMMARY OF THE INVENTION
Thus, according to the present invention, a rubber roller for spinning is provided which has a rubber cot comprising an inner and an outer rubber layer bonded together over a reinforcing layer consisting of a woven cloth or sheeting and fitted securely on the outer periphery of a metal roller core. Also, according to the present invention, there is provided a method of manufacturing a rubber roller for spinning wherein a belt-like laminated sheet consisting of a woven cloth or sheeting and unvulcanized rubber sheet pressed together is wound round a metal core for molding densely with the rubber layer inside, providing an outer cover of unvulcanized rubber layer, subsequently vulcanizing the whole and cutting, if necessary, after releasing from the metal core to the desired width for making a rubber cot consisting of an inner rubber layer, reinforcing layer and outer rubber layer, and this rubber cot is then closely fitted on a metal roller core.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view showing an example of a rubber cot and metal core of a rubber roller for spinning of the present invention.
FIG. 2 is a partially broken-off perspective view showing an example of the rubber roller for spinning of the present invention.
FIG. 3 is an illustratory sketch showing the process of forming an inner rubber layer and reinforcing layer of the rubber roller for spinning of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With a rubber cot in 3-layer structure of the present invention, it is preferred that the thickness of an inner rubber layer 1 is 0.5-3.0 mm and that of a reinforcing layer 2 is 0.1-0.5 mm, and it is further preferred that the interference 5 between the cot and a metal core is between 0.5 and 2.0 mm, preferably 0.5-1.0 mm. If the thickness of the inner rubber layer is less than 0.5 mm, it rather badly interferes with fitting of the rubber cot on the metal core, this being thus unadvisable. It is also unadvisable to have the thickness of the inner rubber layer more than 3.0 mm, for the fitting tightness is then reduced to possibly cause early separation of the rubber cot off the metal core, i.e. early coming-off of the rubber cot. Nor is it advisable to have the thickness of the reinforcing layer less than 0.1 mm for compression on the metal core is then insufficient or more than 0.5 mm for the rubber elasticity of the cot is then affected. The thickness of the outer rubber layer 3 is not specifically limited according to the present invention, but its proper thickness may be approx. 3-30 mm as with ordinary rubber rollers for spinning. Further, for closely fitting the above rubber cot on the metal roller core 4 it is advisable to adjust the interference to 0.5-2.0 mm. If it is less than 0.5 mm, the rubber's contracting force is insufficient, while if it is more than 2.0 mm, insertion of the metal core is difficult. The most preferable range is 0.5-1.0 mm.
The materials for the inner rubber layer and the outer rubber layer according to the present invention are only required to be rubber elastomers, typically nitrile rubber, natural rubber, styrene-butadiene rubber, butadiene rubber, isoprene rubber or the like. The materials for both rubber layers may or may not be identical. For the outer rubber layer, however, preferred is nitrile rubber of good resistance to oil, while for the inner rubber layer preferred is nitrile rubber, natural rubber or styrenebutadiene rubber for reason of the required coefficient of friction as well as for cost reasons. It is also advisable to use for the inner rubber layer a material somewhat lower in hardness than that for the outer rubber layer, this being preferable for tightness of fitting on the metal core and also for resultant improvement in durability. The most preferred combination of rubber materials according to the present invention is such that in terms of hardness according to JIS K 6301-A it is 60°-85° for the inner rubber layer and 70°-90° for the outer rubber layer, preferably 65°-72° for the former and 70°-85° for the latter.
The reinforcing layer of the present invention may be any woven cloth or sheeting flexible with sufficient rigidity, and the sheeting should be pretty thin, e.g. a film. The reinforcing layer material may be one of various natural fibres, regenerated fibres, synthetic fibres, synthetic resins, metals etc. As the woven cloth material cotton or polyamide may be ideal due to their tightening effect as well as for cost reasons. As material of sheeting or film a synthetic resin or metal is preferred. The synthetic resin may be a polyester such as polyethylene terephthalate or a polyamide such as 6-nylon and 6.6-nylon, preferred being uniaxially stretched film for its tightening effect on the metal core, while the preferred metal is aluminium foil or the like. The most preferred material for the reinforcing layer is cotton or polyamide cloth.
The metal roller core of the present invention may be an iron core, preferably with its surface roughened by e.g. by grooving, for improved anchoring of the rubber cot.
In the manufacture of the rubber roller of the present invention, the first to be made is the rubber cot consisting of the inner rubber layer, reinforcing layer and outer rubber layer. The method for making the rubber cot consists in first pressing together an unvulcanized rubber sheet 6 as material of the inner rubber layer and a reinforcing material 7 to obtain a belt-like laminated sheet 8, then winding it around a metal core for molding once or a plurality of times with the rubber layer inside, providing thereafter a cover layer of unvulcanized rubber as material of the outer rubber layer, releasing the resulting cot after subsequent vulcanization from the metal core, cutting it to the desired width and finally finishing it by grinding. The above-mentioned compressing method is not specifically limited but generally preferred is calendering or the like. In winding the laminated sheet round the metal core for molding, it is advisable to wind it densely without any gap but with care to avoid overlapping and finish with the thickness of the reinforcing layer as uniform as possible. The cover of the unvulcanized rubber used as the material of the outer rubber layer is preferably formed by the crosshead extrusion method or the like for better reproduction of the desired thickness, although there is no limitation about the method. A rubber cot consisting of the inner rubber layer, reinforcing layer and outer rubber layer in respective desired thicknesses can thus be obtained.
The rubber roller of the present invention is obtained by closely fitting the above rubber cot on the metal roller core.
Thus, the rubber roller for spinning of the present invention comprises a rubber cot consisting of an inner rubber layer and outer rubber layer with an intervening reinforcing layer closely fitted on a metal core, and is characterized in that insertion of the metal core is easily feasible, the tightening capability of the reinforcing layer is well exhibited after insertion of the metal core and, this acting together with contracting force of the inner rubber layer, the cot-metal core fitting tightness is quite high. Hence, there is no risk of the rubber cot coming off the metal core even in prolonged use and the durability of the rubber roller for spinning is improved remarkably.
Given below are examples for explanation in greater details of the present invention, but it is to be understood that the invention is by no means limited thereby.
EXAMPLE 1
A cotton cloth (thickness: 0.3 mm) and unvulcanized nitrile rubber sheet (hardness 70°, thickness: 1 mm) were pressed together by the use of a quadruple calender roll 9 for making a laminated sheet, and this sheet was cut to the predetermined width (20 mm). The resulting belt-like laminated sheet was wound spirally on the iron core of a proper configuration coated with a mold releasing agent with the reinforcing layer outside and with care to make the thicknesses of both layers uniform, and both ends were then fixed. This was then fed to a crosshead extruder for formation of a covering layer (thickness: 5 mm) of unvulcanized nitrile rubber (hardness 80°) over the reinforcing layer and subsequently it was vulcanized for 30 minutes at 160° C. in a vulcanizer. The vulcanized molding was then taken out of the vulcanizer, released from the iron core for molding, cut to the predetermined size and finished by grinding to a rubber cot (30 mm in outside diameter, 18.5 mm in inside diameter and 25 mm long). The rubber cot so prepared was then closely fitted on a metal core with the required interference (19 mm in outside diameter) by the fitting machine and a rubber roller for spinning of the present invention was thus manufactured.
With the rubber roller so manufactured a durability test was carried out under acceleration conditions of 15 kg in nip load and 200 rpm. in rotational speed, and the result was as shown below in Table 1.
Shown as comparative example are the results of tests with rubber rollers 0.3 and 4.0 mm in inner rubber layer thickness.
TABLE 1______________________________________ Iron Reinforc- core Inner rubberCot size ing layer O.D. layer thick. Test result______________________________________Rubber roller ofthe invention30 mm OD Cotton 19 mm 2.0 mm Not coming off18.5 mm ID 0.3 mm core for more25 mm L 1 month. (No abnormal indication in rubber layer or reinforcing layer)Comp.example30 mm OD Cotton 19 mm 0.3 mm Reinforcing18.5 mm ID 0.3 mm layer broken25 mm L in 6 days.30 mm OD Cotton 19 mm 4.0 mm Cot came off18.5 mm ID 0.3 mm core in 1025 mm L days.______________________________________
Thus, the rubber roller for spinning of the present invention turned out to have an outstanding durability.
EXAMPLE 2
A rubber roller shown in Table 2 was manufactured in the same way as in Example 1 except that aromatic polyamide cloth ("Cornex", Teijin's trade name) was used as the reinforcing material and a durability test was carried out in the same manner as described in Example 1. The result is shown in Table 2 below with data for rubber rollers 0.3 mm and 4.0 mm in inner rubber layer thickness as comparative example.
TABLE 2______________________________________ Iron Inner Reinforc- core rubberCot size ing layer O.D. layer thick. Test result______________________________________Rubber roller ofthe invention30 mm OD Aromatic 19 mm 1.5 mm Not coming off18.5 mm ID polyamide core for more25 mm L cloth than 1 month. 0.2 mm (No abnormal indication in rubber layer or reinforcing layer)Comp.example30 mm OD Aromatic 19 mm 0.3 mm Reinforcing18.5 mm ID polyamide layer broken25 mm L cloth in 9 days. 0.2 mmComp.example30 mm OD Aromatic Cot came off18.5 mm ID polyamide 19 mm 4.0 mm core in 725 mm L cloth days. 0.2 mm______________________________________
Thus, the rubber roller for spinning of the present invention in this example, too, turned out to have an outstanding durability as that in Example 1.
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A rubber roller for spinning whose rubber cot comprises an inner and an outer rubber layer bonded together over a reinforcing layer consisting of a woven cloth or sheeting and fitted securely on the outer periphery of a metal core for roller, without using an adhesive and the manufacturing method thereof.
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BACKGROUND
1. Field of Invention
The water gun launches the water grenade as a grenade launcher and fires the water chain shots accompanied with the synchronous firing click sounds.
2. Description of Prior Art
The conventional water gun projects the stream of fluent. It doesn't simulate the chain shot of machine gun. It doesn't have the sound effect of the chain shot, either. None of the conventional water guns can launch the water grenade. The innovative idea of water gun launched water grenade doesn't exist until now. The water jet not only wastes water but also loses the real battlefield effect. After only a few shots, the player has to stop the battle looking for the faucet to refill the water gun again.
The conventional nozzle has no acceleration effect. The water is uncompressible fluid. It can not expand to accelerate like the gas does. There is no acceleration of the "water bullet". The water pressure drops immediately at the exit of the nozzle. The energy transform is not efficient so that the range is reduced.
During the childish mock combat, the refill of water for the water gun is inconvenient and time-consuming. It is the most dangerous time to be attacked by the enemy. Even worse, as the cap is open or the water tank is removed, the air pressure inside the water reservoir or water tank is released. It takes a lot of time to pump the air to build up the air pressure inside the tank again. Furthermore, while the grenade is a very important combating armor, so far there is no water gun to launch the water grenade.
I invent a water gun which can launch the water grenade. The pumping action is designed to fit the human mechanics. The air pressure is built up with the pumping action of the middle finger, ring finger and little finger. The water gun is triggered with the index finger. One hand can operate the water gun; another hand can install, fire or throw the water gun. The water grenade serves as the portable water reservoir, too. The water grenade can be installed on the water gun quickly and the water gun is refilled immediately. There is no loss of the air pressure that the combat can continue without interrupt. The water gun fires a series of spurts of water accompanied with the clicks of firing sound and mechanical vibration. The "air propellant" and "water bullet" are alternatively aligned to form the chain shot to constitute a series of spurts. The compressible air expands in the pipe that the water bullets are accelerated. The energy transformation is complete that the shooting range is much longer.
OBJECTS AND ADVANTAGES
The water grenade not only serves as the water reservoir but also can be launched by the water gun as a bazooka. The water gun fires a series of spurts of water bullet to simulate the chain shot accompanying with the firing sound and mechanical vibration.
DRAWING FIGURES
FIG. 1 is the side cross-section view of the water gun having the water grenade mounted on it. The air pressure is built up with the pumping action of the fingers.
FIG. 2 is the side cross-section view of the water gun having the water grenade mounted on it. The air pressure is built up with the reciprocal motion of the electrical motor.
FIG. 3 is the side cross-section view of the water gun having the water grenade been launched with the launch tube of the water gun.
FIG. 4 (A) is the side cross-section view of the water turbine in the spurting mechanism; (B) is the side cross-section view of the air turbine in the spurting mechanism.
FIG. 5 (A) is the transverse section view of the spurting mechanism; (B) is the side cross-section view of the firing sound emulator mechanism.
FIG. 6 (A) is the transverse section view of the electrical motor, water turbine and air turbine in the turbo-charging type spurting mechanism; (B) is the side cross-section view of the alternative design for the firing sound emulator mechanism.
FIG. 7 (A) is the cross section view of the water turbine during the water jet period; (B) is the cross section view of the air turbine during the water jet period; the air jet is blocked by the van of the air turbine; the air is injected into the outlet pipe to form the chain shot.
FIG. 8 (A) is the cross section view of the water turbine during the air jet period; the water jet is blocked by the van of the water turbine; the water is injected into the outlet pipe to form the chain shot; (B) is the cross section view of the air turbine during the air jet period.
FIG. 9 is the top view of the water grenade.
FIG. 10 (A) is the cross-section view of the water grenade; (B) is the cross-section view of the water grenade filled with the water.
FIG. 11 is the top view of the discharging water grenade.
FIG. 12 (A) is the cross-section view of the discharging water grenade; (B) is the cross-section view of the discharging water grenade filled with the water.
FIG. 13 is the series of the operations of the water gun and the water grenade; (A) the water grenade serves as the portable water reservoir; (B) the water grenade has the impact head been pulled out; the payload compartment is filled with water; (C) the water grenade is slided in the launch tube to be mounted on the water gun; (D) the water gun points upward and the water flows from the propellant compartment in the water grenade to the water reservoir in the water gun; (E) the water gun fires the chain shot made of water spurts; (F) the water gun launches the water grenade; as the water grenade hits on the target, the water sprays out.
FIG. 14 is the manual operation of the water grenade; (A) the impact head is pulled out; (B) the impact head is pushed in and the water spurts are squeezed out; (C) the water grenade serves as the hand grenade.
DESCRIPTION OF PREFERRED EMBODIMENTS
The water gun comprises a spray gun, a firing sound emulator, a launching tube and a water grenade. The spray gun is to convert the air and fluid to be chain shots. The launching tube is to launch the water grenade with the air pressure. The firing sound emulator is to generate the click sound of the machine gun. FIG. 1 shows my invention implemented with the manual pump to pump up the air pressure. As the kid holds the handle 4 of the water gun, his middle finger, ring finger and the little finger hold and press the pumping pad 40 to pump up the air pressure. The index finger presses the trigger 41 to eject a series of spurts of water.
As the pumping pad 40 is pressed, the piston 72 compresses the air/gas inside the cylinder to flow through the one way valve 71 into the water reservoir. As the pumping pad 40 is released, the spring 77 expands and the vacuum inside the cylinder sucks the air/gas flowing through one-way valve 70 into the cylinder. Continuing pumping the pumping pad 40, the air pressure inside the water reservoir is built up.
The trigger 41 is biased to lock the outlet pipe 31. As the trigger 41 is pressed to release the lock of the outlet pipe, the pressure inside the turbine decreases due to the turbine being neither air-tight nor water-tight. The air pressure in the water gun is much larger than the hydraulic head of the water column in the inlet pipe and the pressure in the turbine is almost the same as the pressure of the outlet pipe. Under the high pressure inside the water reservoir, the air/gas is forced to flow through the inlet pipe 21 and the water/fluent material is forced to flow through the inlet pipe 20. The air jet and water jet impinge on the blades of the turbine 1 alternately. As the turbine 1 rotates, the firing sound emulator generates the synchronous firing sound as shown in FIG. 5 and FIG. 6. At the same time, the turbine 1 inserts the air segment and water segment into the outlet pipe 30 alternatively as shown in FIG. 7 and FIG. 8.
The core of the water gun is the air turbine and the water turbine. As shown in FIG. 4, the turbine 1 constitutes of the air turbine 11 and water turbine 10 having the same axle 19. As shown in FIG. 5, the blades of water turbine and air turbine interlace each other, i.e., the van sections of air turbine 11 are out of phase with the van sections of water turbine 10. As shown in FIG. 7A, as the water jet impinges on the blade of the water turbine, the air passage is blocked by the blade section of air turbine as shown in FIG. 7B. The turbine 1 is driven to rotate under the impinging force of the water jet. As shown in FIG. 8B, as the air jet impinges on the blade of the air turbine, the water passage is blocked by the blade section of water turbine as shown in FIG. 8A. The turbine 1 is driven to rotate under the impinging force of the air jet.
The firing sound emulator is to convert the air pressure to be the click sound. The firing sound emulator comprises the cam and drum. As shown in FIG. 5, the cam 15 is one unit with the axle 19. The drum stick is biased by the spring 18. As the turbine 1 rotates, the cam 15 raises up and suddenly releases the drum stick 17. The drum stick 17 hits on the drum to generate the firing click sound.
FIG. 6 shows the turbine mechanism of the turbo-charge type water gun. The electrical motor 88 is installed in the water gun as shown in FIG. 6A. The motor 88 drives the turbine 1 to rotate. The turbine sucks the water and air into the turbine and compresses them to flow through the outlet pipe 30.
FIG. 6 also shows the alternative design of the firing sound emulator. The cam 12 is one unit with the axle 19. As the turbine 1 rotates, the cam 12 raises up and suddenly releases the drum stick 14. The drum stick 14 hits on the drum 13 to generate the firing click sound.
FIG. 2 is the water gun using the battery 82 to rotate the electric motor 77. As the motor 77 rotates the link 84, the valve 72 moves back and forth reciprocally and the air is pumped into the reservoir 4.
FIG. 3 is the alternative design of the water gun. The trigger 43 of the water grenade is located on the pipe of the water gun. The spring 45 bias the trigger 43 to hook the ring 44 of the water grenade.
Referring to FIG. 1, the reservoir cap 90 can be opened to fill the reservoir 40 with the fluent material. However, it is much more convenient way to fill the reservoir with the water grenade 60. The water grenade 6 can be launched with water gun or thrown with hand. The water grenade 6 is slidably mounted on the launching tube which is located at top of the water gun 2. The handle 66 slides inside the barrel 99. As shown in FIG. 9, the water grenade 6 is similar to the bazooka. There are fins 63 to stabilize the flying attitude. As shown in FIG. 10A, the water grenade is constituted of the impact head 60, trippet 61, payload compartment 62 and propellent compartment 65. As shown in FIG. 13A, the water grenade 6 is filled with the water. As shown in FIG. 10B, the slot 77 in the wall and the slot 78 in the pole 75 of trippet 61 are constituted of a passage. As the impact head 60 is pulled out, the vacuum is generated in the payload compartment 62. As shown in FIG. 13B and FIG. 10B, the water is sucked into the payload compartment 62 from the propellant house 65. After the water is sucked into the payload compartment 62, turn the impact head 90 degrees, the slot 77 in the wall and the slot 78 in the pole 75 of trippet 61 are disconnected as shown in FIG. 1. As shown in FIG. 13C, the water grenade 6 is installed on the water gun 2 with the water gun 2 pointing downward. As shown in FIG. 1, the handle 66 slides into the barrel 99. The breechblock 95 is pushed by the handle 66 to open a gap 96. As shown in FIG. 13D, the water gun 2 points upward and the water flows into the reservoir 4; the compressed air flows into the propellent compartment 65. In FIG. 13E, the water gun is fired.
In FIG. 1, the water gun is at the instant of finishing the firing. The compressed air flows through the gap 96 and slit 68 into the propellent compartment 65 as the propellant. The barrel 99 holds the water grenade, guides the water grenade and converts the potential energy of the compressed air to the kinetic energy of the grenade. The breechblock 95 is slidably mounting on the bolts 93. To insure the seal, the rubber seal 97 is attached to the rim of the hole. As the water grenade is released to speed up in the barrel 99, under the biasing force of the spring 94, the breechblock 95 seals the opening of the barrel 99. Pressing the trigger 42 forward, the water grenade is pushed backward and the lock is released. The propellant, compressed air, expands to propel the water grenade 6 to slide in the barrel 99. The compressed air in the propellant compartment 65 expands and flows through the nozzle 69 to speed up. In this way, as shown in FIG. 13F, the water gun 2 serves as a grenade launcher. As the compressed air flows through the whistle 67, the whistling sound of the flying shell is generated. As the water grenade 6 hits on the target, the trippet 61 squeezed the water in the payload compartment. The water grenade explodes, i.e., the water flows through the valve 73 and sprays on the enemy.
To expel the water completely from the payload compartment 62, as shown in FIG. 12, the wings 630 have the explosion compartment. The compressed air flows into the explosion compartments in wing 630 through the one-way valve 83. The trippet 61 blocks the slot 84 as shown in FIG. 12B. As the impact head 60 is hit and moves backward, the compressed air flows into the payload compartment 62 as shown in FIG. 12A to push the trippet to squeeze the water to spray out completely.
The water grenade 6 can function independently. As shown in FIG. 14A, the impact head 60 is pulled out and the water flows into the payload compartment 65. As shown in FIG. 14B, the impact head 60 is pushed back, the water is squeezed out and sprays forward on the enemy. The water grenade also can be thrown with the hand as the hand grenade. As shown in FIG. 14C, the water grenade is thrown by the hand and explodes to sprays the water on the enemy.
While present exemplary embodiments of this invention, and methods of practicing the same, have been illustrated and described, it will be recognized that this invention may be otherwise variously embodied and practiced within the scope of the following claims.
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A water gun system comprises a water gun, firing sound emulator, launching tube and rocket type water grenade. Converting the air pressure to be the momentum, the water gun generates the chain shot made of the air and fluid and the firing sound emulator generates the click sound of machine gun. Converting the air pressure to be momentum, the launching tube fires rocket type water grenade. Hitting on the target, the rocket type water grenade sprays fluid on the enemy.
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BACKGROUND OF THE INVENTION
This application is a continuation-in-part of Ser. No. 095,412, filed Nov. 19, 1979, now abandoned.
The present invention relates to a process for the production of tablets and to a tabletting machine for execution of the process.
It is well known that tablets used in the pharmaceutical, food and fodder industries are mechanically produced, by processes which include material preparation, granulation, compression and subsequent checking and storage. The most critical part of the operation is compression, which directly affects the physical qualitites (hardness, friability), chemical qualities (preservation of the active ingredients) and biological qualitites (therapeutic effect, bioavailability) of the tablets.
A common problem with known tablet compression processes is that there is no guarantee that the desired physical, chemical and biological qualities will be attained, and therefore production waste may reach levels as high as 20-30%.
Extensive research has been conducted to eliminate the above deficiencies, but this research has been aimed primarily at the physics of the tablet pressing process. See, e.g., T. Higuchi in his article on pages 685-689 of Volume 43/1954 of the J. Am. Pharm. Ass., published in the U.S.A., describing the variation of the tablet volume as a function of the compressive force and the pressure distribution within the tablet Also, see R. Hunttenrauch and V. Dietz reporting the effect of compression velocity on the quality of the tablet on page 47 of Volume 32/1976 of "Pharmazie", published in the German Democratic Republic. However, this research work has not successfully eliminated the problems mentioned before.
Practical experience has shown that the usually prepared granulated matter having a particular moisture content is relatively well tabletted at the operating temperature of the tabletting machine. However, when the moisture content increases even in the slightest degree, the granulated matter sticks to the die, and pressing of the tablet becomes very difficult, or the resultant tablet is deformed. Alternatively, if the moisture content of the granulated matter is slightly less than the optimal value, the resulting tablet undesirably splits into plates.
With reference to storage and date of expiration of the tablets, it is particularly important to note that a higher than optimal moisture content will generally cause the stability of the tablets to decrease logarithmically. Therefore, it is necessary to keep the moisture content at the optimal value or lower during storage.
Another deficiency of the known tabletting processes is that such processes are not suitable for the so-called "direct" tabletting of active ingredients, i.e., tabletting of active ingredients, free of any additives. Examples of such materials free from additives are the soluble active ingredients which are used as aseptic drugs which are administered in the form of an injection. In such injections, the active ingredients comprise no more than a few percent of the total, the remainder being a liquid carrier. At present, these active ingredients are dispensed as a powder contained in ampoules, which powder must be dissolved in distilled water in order to prepare the injectable solution. In view of the small dosage involved (e.g., 10 mg) and the required accuracy of the dose, it would be preferable to dispense these active ingredients in the form of sterile soluble tablets, rather than as a powder, thereby guaranteeing precise dosages.
Various eccentric and circulatory tabletting machines are presently used. These machines have a number of common characteristics, such as having uniaxial and axially driven upper and lower punches, dies, and granulated matter feeding mechanisms.
The present invention is aimed at the improvement of known tabletting machines and tabletting processes, whereby tablets of uniform quality can be produced with minimal waste. The invention is also aimed at a process whereby active ingredients, without additives, can be tabletted directly.
The basic principle underlying the invention is the realization that tablet pressing can be regarded, in some sense, as a non-stoichiometric chemical process. For the first time it has been realized that the tabletting process can be correlated with thermodynamic potential functions, calculated with extensive parameters dependent upon the composition of the system. Hence, it has now been realized that the quality of tablets depends upon the temperature at which tabletting is carried out. Thus, the deficiencies of the tabletting processes can be overcome, provided that the starting materials (organic or inorganic, single or multiple components) are pressed into tablet form while keeping the granulated charge at a predetermined temperature wherein the predetermined temperature is in the range of about 15°-50° C.
In accordance with the present invention, the new tabletting process can be performed with a tabletting machine having upper and lower dies, a matrix, a granulated matter feeding mechanism and a temperature regulating unit for keeping the temperature of the granulated matter during pressing within the optimal temperature range of about 15°-50° C.
The temperature regulation can be accomplished, for example, by various means and methods, such as by providing a temperature regulating unit having channels in the matrix which contain a thermal medium of adjustable temperature. Alternatively, electrical heating wire of adjustable temperature may be arranged in the channels of the matrix to regulate the pressing temperature.
In another possible embodiment, the temperature regulating unit has a heating or cooling unit of adjustable temperature surrounding at least the upper portion of the upper die, thus providing a simple heat exchange to regulate the pressing temperature.
In yet another possible embodiment, the temperature regulating unit has a chamber surrounding the entire tabletting machine and this chamber is connected to a heating or cooling unit of adjustable temperature. In this way, the ambient temperature of the tabletting machine is controlled in a simple way, and, through heat exchange, the temperature of the granulated matter during pressing is also controlled.
The invention is described in detail below based on the drawings showing actual models of the tabletting machine as described in the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagramatic, perspective view of one embodiment of the tabletting machine according to the present invention.
FIG. 2 is a vertical sectional view of the machine of FIG. 1.
FIG. 3 is a partial sectional view of the machine of FIG. 1 showing means for regulating the temperature.
FIG. 4 is a plan view of the matrix of the tabletting machine as shown in FIG. 1.
FIG. 5 shows two different embodiments for regulating the temperature of the machine of FIG. 1.
FIGS. 6A and 6B are diagrammatic vertical sections of additional embodiments for regulating the temperature of the machine of FIG. 1
FIG. 7 is a perspective view of another embodiment of the tabletting machine of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the illustrative embodiments shown in the drawings, FIG. 1 illustrates a rotary tabletting machine of the present invention having conventional upper and lower punches 10 and 11, which are uniaxial and axially driven. The tabletting machine has a conventional die 12 which has through holes in which receive the upper 10 and lower 11 punches during pressing.
The tubular shaft 16 within the tube carrier 15 of the tabletting machine of FIG. 1 is supported on mounting or housing 14 in a conventional way, e.g., on rotatable ball bearings (not shown). The belt pulley 17 is attached to the upper end of the tubular shaft 16 and is connected through belt 18 with the belt pulley 20 of the electric motor 19. Furthermore, the die 12 and the guide disc 21 are connected to the tubular shaft 16 in a conventional way, and turn with the tubular shaft. The guide disc 21 is used for vertically guiding and containing the bases of upper punches 10. In the illustrated embodiment, the upper punches 10 are provided with heads 22, which travel through a forced trajectory in a manner to be described below.
For vertically guiding and housing the lower punches 11 of FIG. 1, the tabletting machine is provided with guide disc 23, which is similarly fixed to the tubular shaft 16 in a conventional manner. The forced trajectories of punches 10 and 11 are not shown in FIG. 1 in order to provide a better overall view.
A granulated matter feeding mechanism 24 is attached to housing 14. This unit 29 consists of a tank 25 and a connected sloping feeding chute 26. The lower end of the feeding chute 26 rests on the upper surface of the die 12 in the area of the rotation path of the holes 13. A sloping tablet collecting trough 27 attached to the housing 14 and is fitted with a small clearance and arm 27a to the top of the die. The tablet collecting box 29 is arranged under the trough 27. The feeding chute 26 and trough 27 are arranged in such a way that the tablet lifted out of the hole 13 of the die 12 with the aid of the lower punch 11 is guided with the help of the feeding chute 26 and arm 27a into the trough 27. The common direction of revolution of the tubular shaft 16, die 12, and guide discs 21 and 23 is shown by reference number 28 on the drawing of FIG. 1.
One means for obtaining the forced trajectories of the upper 10 and lower 11 punches is clearly shown in FIG. 1. Here, the upper punches 10 follow a cam track 30, which in this case is attached to the tube carrier 15. (The means for attachment is not shown.) The cam track 30 includes the lower guide 30a, upper guide 30b, and the unit which drives the punches 10 downward for pressing, in this case roller 30c, which freely rotates about a horizontal axis (not shown). The cam track of the lower punches 11a is shown by reference number 31. In this case, cam track 31 is attached similarly to the tube carrier 15 (attachment not shown) and includes the lower guide 31a, cam 31b and roller 31c which rotates about a horizontal axis (not shown) to drive punches 11 upward.
The upper punches 10 and lower punches 11 shown on the left side of FIG. 2, are kept in the extreme end positions by the guides 30a and 31a when the feeding chute 26 feeds the granulated charge into the pressing space 32. The punches 10 and 11 shown in the center of FIG. 2 are forced into the pressing position by rollers 30c and 31c. At the right hand side of FIG. 2 it is shown how the upper punch 10 is driven upwardly by the rising part of guide 30a. At the same time, the cam 31b, attached to guide 31a, drives the lower punch 11 to its upper position. In this position, the lower punch 11 lifts the finished tablet 33 from the pressing space 32 to the level of the upper plane of the die 12. The apparatus illustrated in to FIG. 2 differs somewhat from the apparatus of FIG. 1 inasmuch as the lower punches 11 are guided in the die 12 and hence, guide disc 23 is not needed in this embodiment.
According to the invention, the tabletting machine is provided with temperature regulating unit 34, the purpose of which is to maintain the predetermined optimal temperature range of the granulated charge during pressing.
The first embodiment of regulating unit 34 is shown in FIG. 1. As further illustrated in FIGS. 3 and 4, temperature regulating unit 34 includes annular ducts 35 and 36 formed in the die 12 which are connected to a source of thermal medium of adjustable temperature FIG. 3 shows in detail how the ducts 35 and 36 are connected to each other through holes 37.
As shown in FIGS. 1 and 4, pipes 40 and 41 are arranged in the central space 39 of the tubular shaft 16 shown in FIG. 1. These pipes lead into duct 35 through their horizontal branches 40a and 41a within the die. Either a liquid or a gaseous thermal medium, e.g., water or oil, be introduced into the ducts 35 and 36 from the source of medium via the pipes 40 and 41. The temperature of the medium can be regulated with a conventional heating or cooling unit 42 connected to a control panel 43 in a conventional manner.
According to the invention, another embodiment of the unit for regulating the pressing temperature is shown in the center of FIG. 5. In that embodiment, an electric heating wire 44 of adjustable temperature is arranged in the duct 35a of the die 12. This unit is marked with reference number 34a. The supply cables 44a of the heating wire 44 can be connected (connection not shown) to the electrical regulating unit through the central space 39 of the tubular shaft 16.
For simplicity's sake, a third embodiment of the temperature regulating unit is also shown in the upper portion of FIG. 5 and marked with reference number 34b. Here the upper punch 10 has a duct 45 containing electric heating wires 46 of adjustable temperature. The heating wires 46 are connected to the regulating unit connection (not shown) supplying electricity.
FIGS. 6a and 6b show yet another temperature regulating unit 34c controlling the pressing temperature by providing a heating or cooling unit 47 which surrounds the upper punch 10 in it supper end position. This unit has an annular cavity 49 in a cylindrical housing 48 connected to a source of thermal medium (not shown) whose temperature can be controlled. This construction allows the temperature of the upper punch 10, and therefore the pressing temperature, to be adjusted by convection. In this case the heat transfer to the punch 10 takes place while the punch is in the upper end position shown in FIG. 6a. The pressing position is shown in FIG. 6b.
Finally, FIG. 7 is an illustration of another embodiment of the tabletting machine of the present invention where the temperature regulating unit 34 regulates the pressing temperature by means of a chamber 50 which surrounds the entire tabletting machine. This chamber 50 is associated with heating or cooling unit 51 which maintains the required operating temperature of the entire tabletting machine at all times. In the embodiment shown in FIG. 7, like numbers are used to correspond with the prior drawings.
It is possible that the desired results can be obtained through various combinations of the suggested heat regulating units. It is also possible to obtain the desired results by regulating the temperature directly of the granulated charge through the use of a heating or cooling unit.
Best Mode Of Carrying Out The Invention
The experiments conducted with regard to this invention can be illustrated in the following three examples:
EXAMPLE 1
Tabletting of granulated matter requiring minimal moisture content for stability is carried out with a rotating tabletting machine equipped with temperature regulating unit 34a. 100 kg of acetylsalicylic acid of 0.32 mm mesh size sieve fineness, and 8.7 kg dried potato starch of 4-6% moisture content were homogenized by conventional method. This was followed by mixing a homogenized powdery mixture of talc and 2.5 kg of stearine of 0.06 mm mesh size sieve fineness with the previously prepared mixture.
200,000 tablets of good quality were then pressed from this granulated matter of about 0.5% moisture content, at a preliminary pressing temperature of 45±2° C. with about 1000 kp/cm 2 pressure. EXAMPLE 2
Tablet pressing was performed with the tablet pressing machine shown in FIGS. 1, 3 and 4. 40 kg of papaverinechloride and 15 kg of potato starch were first granulated and mixed with a solution of 3 kg polyvinyl pirrolydone and 8 kg of water. This was then dried and after regranulation, was mixed with a powdery mixture of 1.5 kg talc and 1.5 kg magnesium stearate. Tablets were then pressed with said tabletting machine at a regulated pressing temperature of 27±2° C. and at a pressure of 900 kp/cm . The quality of the tablets according to the control tests was found to be excellent.
EXAMPLE 3
So-called direct tabletting of active ingredients without additives was carried out with a tabletting machine according to the invention. One weight fraction of 1.2-5.6 dianhydro-dulcite was dissolved in two weight fractions of water-free menthol at 50° C. temperature. The solution was filtered while hot and allowed to stand for 24 hours at 23±2° C. The separated crystals were filtered and dried in one Hg mm vacuum at 30° C. until a stable weight was achieved. This resulted in a mixture of monoclinic and triclinic crystal forms having a melting point of 100°-102° C. The grain size distribution of the recrystalized polymorphous mixture was optimal for direct tabletting when 85-90% of the mixture was 0.6-0.8 mm in size, and the moisture content did not exceed 0.2%.
Under the above conditions 100 mg soluble tablets were pressed from 1.2-5.6 dianhydro-dulcite basic material, free of additives, with 5 mm diameter dies at 900±100 kp/cm 2 pressure at the preregulated pressing temperature of 32±2° C. At a lower temperature the tablets split into plates, and at a higher temperature the tablets remain stuck to the die, neither case being satisfactory.
In accordance with the present invention, sterile soluble tablets can be produced which are suitable for injection and dispensing in rubber capped ampoules while meeting accepted standards for aseptic drug production. Dispersion of these tablets can be kept within the permissible range of tolerance.
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This invention relates to a process and an apparatus for producing tablets of good quality with minimal waste by compressing granulated matter at a regulated temperature. An important advantage of the invention is that it permits direct tabletting of active ingredients without the need to include additives in the tablets.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a new hose assembly and new internally threaded member therefor as well as to a new method of making such a hose assembly and to a new method of making a such an internally threaded member.
2. Prior Art Statement
It is known to provide a hose assembly comprising a flexible hose having opposite ends, an internally threaded member mounted on one of the opposite ends in a manner to swivel thereon to permit the internally threaded member to be finger coupled to an externally threaded part of a liquid dispensing spigot, the internally threaded member having an outer peripheral surface, and an annular member disposed around the internally threaded member in a manner to engage the outer peripheral surface thereof and having an external peripheral surface to be finger engaged for turning the internally threaded member in unison therewith relative to the hose. For example, see the U.S. patent to Magarian, U.S. Pat. No. 4,058,031 and the U.S. patent to Swisher, U.S. Pat. No. 4,805,933.
SUMMARY OF THE INVENTION
It is one of the features of this invention to provide a new hose assembly wherein the internally threaded member that is swivelly mounted on one of the opposite ends of a flexible hose has a unique annular member disposed there around in a manner to engage the outer peripheral surface thereof and having an external peripheral surface to be finger engaged for turning the internally threaded member in unison therewith relative to the hose.
In particular, it is believed according to the teachings of this invention that the material of the annular member should comprise a SANTOPRENE material as the same is a soft surface material that is non-slippery when wet or dry.
For example, one embodiment of this invention provides a hose assembly comprising a flexible hose having opposite ends, an internally threaded member mounted on one of the opposite ends in a manner to swivel thereon to permit the internally threaded member to be finger coupled to an externally threaded part of a liquid dispensing spigot, the internally threaded member having an outer peripheral surface, and an annular member disposed around the internally threaded member in a manner to engage the outer peripheral surface thereof and having an external peripheral surface to be finger engaged for turning the internally threaded member in unison therewith relative to the hose, the annular member comprising a SANTOPRENE material.
It is another feature of this invention to mold an annular plastic member around the internally threaded member so as to be secured thereto.
For example, another embodiment of this invention comprises a hose assembly comprising a flexible hose having opposite ends, an internally threaded member mounted on one of the opposite ends in a manner to swivel thereon to permit the internally threaded member to be finger coupled to an externally threaded part of a liquid dispensing spigot, the internally threaded member having an outer peripheral surface, and an annular plastic member disposed around the internally threaded member in a manner to engage the outer peripheral surface thereof and having an external peripheral surface to be finger engaged for turning the internally threaded member in unison therewith relative to the hose, the annular plastic member having been molded onto the internally threaded member.
Accordingly, it is an object of this invention to provide a new hose assembly having one or more of the novel features of this invention as set forth above or hereinafter shown or described.
Another object of this invention is to provide a new method of making such a hose assembly, the method of this invention having one or more of the novel features of this invention as set forth above or hereinafter shown or described.
Another object of this invention is to provide a new internally threaded member for such a hose assembly, the internally threaded member of this invention having one or more of the novel features of this invention as set forth above or hereinafter shown or described.
Another object of this invention is to provide a new method of making such an internally threaded member, the method of this invention having one or more of the novel features of this invention as set forth above or hereinafter shown or described.
Other objects, uses and advantages of this invention are apparent from a reading of this description which proceeds with reference to the accompany drawings forming a part thereof and wherein:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary perspective view of a prior known hose assembly having an internally threaded member swivelly mounted on one end of the flexible hose thereof.
FIG. 2 is an enlarged fragmentary cross-sectional view taken on line 2--2 of FIG. 1.
FIG. 3 is a perspective view of the new internally threaded member of the new hose assembly of this invention.
FIG. 4 is an exploded cross-sectional view illustrating one method of disposing the annular member over the internally threaded member to form the internally threaded assembly of this invention that is illustrated in FIG. 3.
FIG. 5 is a view similar to FIG. 4 and illustrates the outer annular member disposed in its final position on the internally threaded member.
FIG. 6 is a front view of the internally threaded member illustrated in FIG. 5 and schematically illustrates the same mounted to an end of a flexible hose to form the new hose assembly of this invention in a manner similar to the prior known hose assembly of FIG. 2, FIG. 6. being taken in the direction of the arrows 6--6 of FIG. 5.
FIG. 7 is a cross-sectional view illustrating how another embodiment of the internally threaded member of this invention is formed by molding the annular plastic outer member onto the internally threaded member, FIG. 7 illustrating the mold device disposed around the internally threaded member and before the mold material is injected therein.
FIG. 8 is a view similar to FIG. 7 and illustrates the mold arrangement after the mold material has been injected therein.
FIG. 9 is a reduced perspective view illustrating the finished internally threaded assembly formed by the method illustrated in FIGS. 7 and 8.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
While the various features of this invention are hereinafter illustrated and described as providing a hose assembly wherein the internally threaded member initially has an external peripheral surface of a particular configuration, it is to be understood that the various features of this invention can be utilized singly or in various combinations thereof to provide a new hose assembly that can be utilized with internally threaded members other than the particular internally threaded member illustrated in the drawings.
Therefore, this invention is not to be limited to only the embodiments illustrated in the drawings, because the drawings are merely utilized to illustrate one of the wide variety of uses of this invention.
Referring now to FIGS. 1 and 2, a typical prior known hose assembly is generally indicated by the reference numeral 20 and comprises a flexible hose 21 having opposite ends. Only the opposite end 22 is illustrated in FIGS. 1 and 2 with the understanding that the other opposite end of the flexible hose 21 is coupled to an externally threaded member for coupling to an internally threaded member that is swivelly mounted on an end of another hose in order to provide an extension therewith in a manner well known in the art.
An internally threaded member 23 formed of any suitable material, such as metallic material, plastic material, etc., has an internally threaded opening 24 interrupting an end 25 of the internally threaded member 23 and terminating adjacent an inwardly directed annular flange 26 that forms part of the other side 27 of the internally threaded member 24 and is received in an annular groove 28 of a flared end 29' of an internal metallic coupling member 29 that is adapted to be inserted into the end 22 of the flexible hose 21 and be crimped thereto together with an external metallic ferrule member 30 all in a manner well known in the art.
In this manner, the internally threaded member 23 swivels on the end 22 of the flexible hose 21 and readily permits the same to be finger coupled to an externally threaded part of a liquid dispensing spigot or the like by the user engaging his fingers against the external peripheral surface 31 of the internally threaded member 23 and rotating the internally threaded member 23 in the proper direction to couple onto an externally threaded part of a dispensing spigot that is received in the internally threaded opening 24 of the internally threaded member 23 in a manner well known in the art.
Usually the external peripheral surface 31 of the internally threaded member 23 is provided with a plurality of serrations 32 and/or projections 33 to facilitate the finger coupling or uncoupling operation as the case may be.
Nevertheless, it has been found that the finger coupling operation should be enhanced by providing an annular member over the external peripheral surface 31 of the internally threaded member 23 so that the external peripheral surface of that annular member will be more finger friendly in the coupling and uncoupling operation of the hose assembly.
For example, see the aforementioned U.S. patent to Magarian, U.S. Pat. No. 4,058,031 and the aforementioned U.S. patent to Swisher, U.S. Pat. No. 4,805,933 whereby these two U.S. patents are being incorporated into this disclosure by this reference thereto.
It is believed according to the teachings of this invention that the annular member being disposed on the external peripheral surface of the internally threaded member can be further enhanced if the same is formed of a SANTOPRENE material as such material is a soft surface material that is non-slippery when wet or dry.
It is further believed according to the teachings of this invention that such annular member of SANTOPRENE material can be either snap-fitted onto the internally threaded member to be carried thereby or can be molded directly thereon so that the annular member will rotate in unison with the internally threaded member when a person is finger coupling or uncoupling the hose assembly to or from an externally threaded part of a liquid dispensing spigot or the like.
"SANTOPRENE" is a registered trademark of the Monsanto Corporation of St. Louis, Mo. and it is well known that there are numerous SANTOPRENE materials sold by the Monsanto Rubber Chemicals Division, Monsanto Industrial Chemicals Co., 260 Springside Drive, Akron, Ohio., SANTOPRENE being a thermoplastic elastomer which exhibits rubber-like properties.
Thus, it is believed according to the teachings of this invention that at least one of such SANTOPRENE materials will uniquely function to form the annular member of this invention for the internally threaded member of the hose assembly of this invention.
Referring now to FIGS. 3, 5 and 6, the new hose assembly of this invention is generally indicated by the reference numeral 20A in FIG. 6 and parts thereof similar to the parts of the hose assembly 20 previously described are indicated by like reference numerals followed by the reference letter A.
The hose assembly 20A of this invention has the flexible hose 21A provided with an internally threaded member 23A swivelly mounted on an end thereof in the same manner as the internally threaded member 23 of the hose assembly 20. However, an annular member 34 of SANTOPRENE material is disposed over and against the external peripheral surface 33A of the internal threaded member 23A and has an external peripheral surface 35 that somewhat conforms to the external peripheral surface 33A of the internally threaded member 23A and is adapted to be finger engaged for swiveling the internally threaded member 23A in unison therewith for coupling or uncoupling the hose assembly 20A to an externally threaded part of a dispensing spigot or the like.
As previously stated, the external peripheral surface 35 of the annular member 34 when formed of SANTOPRENE material is a soft surface and is non-slippery when dry or wet so as to enhance the finger coupling and uncoupling operation for the reasons previously set forth.
Since the internally threaded member 23A now has the annular member 34 disposed thereon, the parts 23A and 34 now define a new internally threaded assembly that is generally indicated by the reference numeral 36 in FIGS. 3, 5 and 6.
It is believed that the member 34 of the internally threaded assembly 36 of this invention can initially comprise a tubular part 37 as illustrated in FIG. 4 having an internally smooth peripheral surface 38 that is approximately the same diameter as an annular shoulder 39 on the internally threaded member 23A and is stepped below the external peripheral surface 33A thereof as illustrated in FIG. 4. However, by stretching the member 37 onto the internally threaded member 23A so that the internal peripheral surface 38 of the tubular member 37 goes over the external peripheral surface 33A of the internally threaded member 23A, a trailing portion 40 of the tubular member 37 will snap fit into the recess 41 defined by the annular shoulder 39 in the manner illustrated in FIG. 5 so as to secure the annular member 34 of this invention in its final position to form the internally threaded member 23A for the hose assembly 20A and for the purposes previously set forth.
However, it is believed that the annular member of SANTOPRENE material or even of any other desired plastic material could be injection molded onto the internally threaded member 23A to secure the same together for the same purpose as snap-fitting the member 34 in place.
For example, reference is now made to FIGS. 7, 8 and 9 wherein another internally threaded assembly of this invention is generally indicated by the reference numeral 36B and parts thereof similar to the parts of the internally threaded assembly 36 of FIGS. 3-6, are indicated by like reference numerals followed by the reference letter "B".
As illustrated in FIGS. 7, the internally threaded member 23B together with or without the coupling member 29B is disposed in a chamber or cavity 42 of a molding apparatus 43, the chamber 42 of the molding apparatus 43 defining an annular chamber that corresponds in configuration to the annular member 34 of FIGS. 3, 5 and 6.
As illustrated in FIG. 8, suitable polymeric material 44 is injection molded into the cavity 42 to be molded against the external peripheral surface 33B of the internally threaded member 23A so as to subsequently harden or vulcanize and form the internally threaded assembly 36B illustrated in FIG. 9 whereby the external peripheral surface 35B is adapted to be finger engaged for coupling and uncoupling to an externally threaded part of a liquid dispensing spigot or the like for the reasons previously set forth and should the plastic material 44 comprise a SANTOPRENE material, the material 44 will have the characteristics of being a soft surface and non-slippery when wet or dry for the reasons previously set forth.
Therefore, it can be seen that this invention not only provides a new hose assembly and a new internally threaded member for such a hose assembly, but also this invention provides a new method of making such a hose assembly and a new method of making an internally threaded member.
While the forms and methods of this invention now preferred have been illustrated and described as required by the Patent Statute, it is to be understood that other forms and method steps can be utilized and still fall within the scope of the appended claims wherein each claim sets forth what is believed to be known in each claim prior to this invention in the portion of each claim that is disposed before the terms "the improvement" and sets forth what is believed to be new in each claim according to this invention in the portion of each claim that is disposed after the terms "the improvement" whereby it is believed that each claim sets forth a novel, useful and unobvious invention within the purview of the Patent Statute.
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A hose assembly, an internally threaded member therefor and methods of making the same are provided, the hose assembly comprising a flexible hose having opposite ends, an internally threaded member mounted on one of the opposite ends in a manner to swivel thereon to permit the internally threaded member to be finger coupled to an externally threaded part of a liquid dispensing spigot, the internally threaded member having an outer peripheral surface, and an annular member disposed around the internally threaded member in a manner to engage the outer peripheral surface thereof and having an external peripheral surface to be finger engaged for turning the internally threaded member in unison therewith relative to the hose, the annular member comprising a SANTOPRENE material.
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TECHNICAL FIELD
The present disclosure relates to communication between instruments and in particular the mirroring of instruments.
BACKGROUND
An energy services interface (ESI), which may be located in an electric meter, for example, provides security and coordination functions that enable secure interactions between relevant home area network (HAN) devices and a utility company. The ESI is the top of the network and may provide pricing, messaging, demand response/load control (DRLC) events, timing, and maintain keys. It also may provide auditing or logging functions that record transactions to and from home area networking devices.
Typically the ESI is capable of receiving information from a battery powered meter, and presents an interface to other home area network (HAN) devices. The battery powered meter may wake up and post its metering data to the ESI.
BRIEF DESCRIPTION OF THE INVENTION
Disclosed herein are methods, apparatuses, and systems for mirroring instruments. In an embodiment, a plurality of mirror capable devices may report their capability. A mirror capable device may be selected from the plurality of mirror capable devices based on signaling conditions associated with a utility device's power consumption. HAN devices may query the mirror capable device instead of the utility device.
In an embodiment, a method is provided including the steps of determining the signaling conditions of mirror capable devices, selecting a mirror capable device based on the signaling conditions associated with power consumption of a utility device, and forming a mirror between the selected mirror capable device and the utility device.
In another embodiment, a utility device is configured to determine the signaling conditions of mirror capable devices, select a mirror capable device based on the signaling conditions associated with power consumption of transmitting data to the mirror capable device, and transmit data to the selected mirror capable device.
In yet another embodiment, a system includes a utility device, and a mirror capable device selected from a plurality of mirror capable devices, the selected mirror capable device configured to receive data from the utility device, the received data mirrored by the selected mirror capable device, the selection based on power consumption of the utility device associated with signaling conditions between the utility device and the selected mirror capable device.
This Brief Description of the Invention is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Brief Description of the Invention is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. Furthermore, the claimed subject matter is not limited to limitations that solve any or all disadvantages noted in any part of this disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features, aspects, and advantages of the present subject matter will become better understood when the following detailed description is read with reference to the accompanying drawings, wherein:
FIG. 1 is a graphical representation of an exemplary, non-limiting network in which mirroring of a utility device instrument may occur;
FIG. 2 is a non-limiting example method of performing an embodiment of the present disclosure.
FIG. 3 is a non-limiting example method of performing an embodiment of the present disclosure.
FIG. 4 is a non-limiting example method of performing an embodiment of the present disclosure.
FIG. 5 is an exemplary block diagram representing a general purpose computer system in which aspects of the present invention thereof may be incorporated.
DETAILED DESCRIPTION OF THE INVENTION
A mirroring device may be a constantly powered line powered device capable of receiving information from a utility device (e.g. a battery powered utility device). The mirror device may present an interface to other home area network (HAN) devices as if the mirrored device is located inside the constantly powered line device. For example, battery powered gas and water meters may use a line powered device to act as a mirror. Periodically a battery powered meter may wake up from a reduced power mode and transmit metering data to a mirror device or the data communications component may wake up from a reduced power mode and transmit metering data to a mirror device. The battery powered meter may then go back to sleep or reduced power mode, or the data communications component may return to a reduced power mode. HAN devices may interface with the mirror device and retrieve the latest data. Mirror devices may be located in an energy services interface (ESI).
In an embodiment, the line powered device which has the mirror may perform the functions as the mirrored device. The line powered mirror may simply respond to meter reads from other HAN devices, or may be programmed to post the mirrored data to the ESI. The line powered device may further register a mirror with the ESI, such that the ESI responds the same as if the gas meter was mirroring directly with the ESI.
In an embodiment, the transmit power of a gas meter may be reduced and the battery life of the gas meter may be extended if the closest powered device is selected as a mirror device. In an embodiment, the closest device may be defined as the device with the lowest signal loss between a battery powered transmitter and a line powered receiver.
FIG. 1 is a graphical representation of an exemplary, non-limiting network in which mirroring of a battery operated instrument may occur. All devices in FIG. 1 may be communicatively connected and may communicate via wires or wirelessly. At block 105 there may be a battery powered device connected via connection 140 to battery powered meter 135 . At block 107 there may be a line powered device connected via connection 110 to battery powered meter 135 . At block 115 there may be an electronic service interface connected via connection 120 to battery powered meter 135 . At block 125 there may be a line powered device connected via connection 130 to battery powered meter 135 .
In an embodiment, all the devices and interfaces in FIG. 1 may connect to battery powered meter 135 via a wireless connection. Battery powered meter 135 may use a different transmit power to communicate with each device. For example, connection 140 (signal to noise ratio or received signal strength) may be at 10 dB, connection 110 may be at 15 dB, connection 120 may be at 20 dB, and connection 130 may be at 5 dB. Line powered device 125 may be chosen as a mirror device because of the low transmit power needed by battery powered meter 135 to connect via connection 130 , in comparison with the other devices.
Although discussed herein is the use of line powered devices as a mirror device, battery powered devices may also be used as a mirror device. In an embodiment, battery powered device 105 may be the closest device to battery powered meter 135 and therefore may be chosen as the mirror device. Battery powered device 105 may not need to conserve as much energy as battery powered meter 135 because it may have a large battery, a battery recharging source (e.g., recharged via solar or wind), may use power much more efficiently due its configuration, or the like. In an embodiment, the closer battery powered device 105 may be ignored in instances where battery powered device 105 may not be reliably or determinatively awake when the battery powered meter 135 is ready to write (this may also apply to constantly powered, e.g., line powered, devices).
FIG. 2 is a non-limiting example method of performing an embodiment of the present disclosure. Method 200 may be performed by computing equipment including servers, routers, smart meters, mobile devices or any other device that can execute computing functions. At block 205 , mirror capable devices may report their mirror device capability. At block 210 , a battery powered meter may determine signaling conditions to each mirror capable device. At block 215 , a mirror device is selected based on predetermined threshold conditions. At block 220 , the battery powered meter periodically transmits data to the selected mirror device.
In an embodiment, the threshold condition may be associated with the transmit power needed to reach the mirror capable device. In an embodiment, a threshold condition may be associated with line quality (e.g., packet loss or degradation). If packet loss is high on a mirror capable device it may cause the battery powered meter to transmit multiple times and therefore unappealingly drain more power (even with a low transmit power), the battery powered meter may choose a mirror capable device with less packet loss. In an embodiment, multiple conditions may be considered, such as a condition associated with the reliability of the mirror capable device in receiving transmitted data (e.g., the mirror capable device may frequently be in a condition, such as powered off, that will not allow reception of data) and a condition associated with the mirror capable devices power source (e.g., line or battery powered).
FIG. 3 is a non-limiting example method of performing an embodiment of the present disclosure. Method 300 may be performed by computing equipment including servers, routers, smart meters, mobile devices or any other device that can execute computing functions. At block 305 , each mirror capable device may report its mirror device capability to an ESI. At block 310 , a battery powered meter may ping the mirror capable devices to determine RF signal strength to each device. The battery powered meter may select a mirror capable device based on a condition. The condition may comprise one or a combination of RF signal strength, device power source, and device availability, among other things. At block 315 , the battery powered meter may request a mirror form the selected mirror capable device. At block 320 , the selected mirror capable device may form a mirror. At block 325 , the battery powered meter may periodically transmit data to the selected mirror capable device. At block 330 , the selected mirror capable device may transmit the mirror updates to the ESI mirror after it receives the mirror updates from the battery powered meter.
FIG. 4 is a non-limiting example method of performing an embodiment of the present disclosure. Method 400 may be performed by computing equipment including servers, routers, smart meters, mobile devices or any other device that can execute computing functions. At block 405 , each mirror capable device may report its mirror device capability to an ESI. At block 410 , each mirror capable device may measure the signal strength to the battery powered meter and report the signal strength to the ESI. At block 415 , a battery powered meter may request a mirror capable device from ESI. At block 420 , the ESI may select the mirror capable device based on conditions. The conditions may comprise one or a combination of signal strength, device power source, and device availability, among other things. At block 425 , the ESI may transmit an address (e.g., IP address) of the selected mirror capable device to the battery powered meter. At block 430 , the battery powered meter may request a mirror from the selected mirror capable device. At block 435 , the selected mirror capable device may form a mirror. At block 440 , the battery powered meter may periodically transmit data to the selected mirror capable device. At block 445 , the after selected mirror capable device may receive mirror updates and transmit the mirror updates to the ESI mirror.
The conditions associated with a mirror capable device may change over the course of time. For example, the transmit power needed to communicate with a mirror capable device may increase or decrease because of weather conditions or device degradation. In an embodiment, the threshold conditions may be checked periodically and a new mirror device may be selected based on the previous or new threshold conditions. In an embodiment, the threshold conditions may dynamically change based on analysis of power consumption data of a particular meter/mirror device combination, power consumption data from a plurality of meter/mirror device combinations (e.g., a county or region), or the like.
Without in any way limiting the scope, interpretation, or application of the claims appearing herein, a technical effect of one or more of the example embodiments disclosed herein is to provide adjustments to communication protocols so that battery life of a battery powered meter may be extended. Another technical effect of one or more of the embodiments disclosed herein is that the battery powered meter may select the mirror device closest to it. This selection of a mirror device close to the meter may result in faster response time and less power consumption.
FIG. 5 and the following discussion are intended to provide a brief general description of a suitable computing environment in which the present invention and/or portions thereof may be implemented. Although not required, the invention is described in the general context of computer-executable instructions, such as program modules, being executed by a computer, such as a client workstation, server or personal computer. Generally, program modules include routines, programs, objects, components, data structures and the like that perform particular tasks or implement particular abstract data types. Moreover, it should be appreciated that the invention and/or portions thereof may be practiced with other computer system configurations, including hand-held devices, multi-processor systems, microprocessor-based or programmable consumer electronics, network PCs, minicomputers, smart meters, mainframe computers and the like. The invention may also be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules may be located in both local and remote memory storage devices.
FIG. 5 is a block diagram representing a general purpose computer system in which aspects of the present invention and/or portions thereof may be incorporated. As shown, the exemplary general purpose computing system includes a computer 520 or the like, including a processing unit 521 , a system memory 522 , and a system bus 523 that couples various system components including the system memory to the processing unit 521 . The system bus 523 may be any of several types of bus structures including a memory bus or memory controller, a peripheral bus, and a local bus using any of a variety of bus architectures. The system memory includes read-only memory (ROM) 524 and random access memory (RAM) 525 . A basic input/output system 526 (BIOS), containing the basic routines that help to transfer information between elements within the computer 520 , such as during start-up, is stored in ROM 524 .
The computer 520 may further include a hard disk drive 527 for reading from and writing to a hard disk (not shown), a magnetic disk drive 528 for reading from or writing to a removable magnetic disk 529 , and an optical disk drive 530 for reading from or writing to a removable optical disk 531 such as a CD-ROM or other optical media. The hard disk drive 527 , magnetic disk drive 528 , and optical disk drive 530 are connected to the system bus 523 by a hard disk drive interface 532 , a magnetic disk drive interface 533 , and an optical drive interface 534 , respectively. The drives and their associated computer-readable media provide non-volatile storage of computer readable instructions, data structures, program modules and other data for the computer 520 .
Although the exemplary environment described herein employs a hard disk, a removable magnetic disk 529 , and a removable optical disk 531 , it should be appreciated that other types of computer readable media which can store data that is accessible by a computer may also be used in the exemplary operating environment. Such other types of media include, but are not limited to, a magnetic cassette, a flash memory card, a digital video or versatile disk, a Bernoulli cartridge, a random access memory (RAM), a read-only memory (ROM), and the like.
A number of program modules may be stored on the hard disk, magnetic disk 529 , optical disk 531 , ROM 524 or RAM 525 , including an operating system 535 , one or more application programs 536 , other program modules 537 and program data 538 . A user may enter commands and information into the computer 520 through input devices such as a keyboard 540 and pointing device 542 . Other input devices (not shown) may include a microphone, joystick, game pad, satellite disk, scanner, or the like. These and other input devices are often connected to the processing unit 521 through a serial port interface 546 that is coupled to the system bus, but may be connected by other interfaces, such as a parallel port, game port, or universal serial bus (USB). A monitor 547 or other type of display device is also connected to the system bus 523 via an interface, such as a video adapter 548 . In addition to the monitor 547 , a computer may include other peripheral output devices (not shown), such as speakers and printers. The exemplary system of FIG. 5 also includes a host adapter 555 , a Small Computer System Interface (SCSI) bus 556 , and an external storage device 562 connected to the SCSI bus 556 .
The computer 520 may operate in a networked environment using logical connections to one or more remote computers, such as a remote computer 549 . The remote computer 549 may be a personal computer, a server, a router, a network PC, a peer device or other common network node, and may include many or all of the elements described above relative to the computer 520 , although only a memory storage device 550 has been illustrated in FIG. 5 . The logical connections depicted in FIG. 5 include a local area network (LAN) 551 and a wide area network (WAN) 552 . Such networking environments are commonplace in offices, enterprise-wide computer networks, intranets, and the Internet.
When used in a LAN networking environment, the computer 520 is connected to the LAN 551 through a network interface or adapter 553 . When used in a WAN networking environment, the computer 520 may include a modem 554 or other means for establishing communications over the wide area network 552 , such as the Internet. The modem 554 , which may be internal or external, is connected to the system bus 523 via the serial port interface 546 . In a networked environment, program modules depicted relative to the computer 520 , or portions thereof, may be stored in the remote memory storage device. It will be appreciated that the network connections shown are exemplary and other means of establishing a communications link between the computers may be used.
Computer 520 may include a variety of computer readable storage media. Computer readable storage media can be any available media that can be accessed by computer 520 and includes both volatile and nonvolatile media, removable and non-removable media. By way of example, and not limitation, computer readable media may comprise computer storage media and communication media. Computer storage media include both volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can be accessed by computer 520 . Combinations of any of the above should also be included within the scope of computer readable media that may be used to store source code for implementing the methods and systems described herein. Any combination of the features or elements disclosed herein may be used in one or more embodiments.
In describing preferred embodiments of the subject matter of the present disclosure, as illustrated in the Figures, specific terminology is employed for the sake of clarity. The claimed subject matter, however, is not intended to be limited to the specific terminology so selected, and it is to be understood that each specific element includes all technical equivalents that operate in a similar manner to accomplish a similar purpose.
This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.
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Techniques for mirroring to allow for data transmissions from a device through mirror capable device. In an embodiment, a plurality of mirror capable devices may report their capability, which may include signaling conditions related thereto. A mirror capable device may be selected from the plurality of mirror capable devices based on signaling conditions associated with the utility device's power consumption.
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FIELD OF THE INVENTION
This invention relates to a process furnace, and more particularly to a reforming furnace having a convection section with an efficient design.
BACKGROUND OF THE INVENTION
Several important chemical processes use a high temperature furnace to drive catalytic reactions. Examples include steam reforming of light hydrocarbons for the manufacture of synthesis gas for ammonia, methanol and hydrogen plants, and steam pyrolysis of saturated hydrocarbons to produce olefins. Such furnaces generally include a refractory-lined radiant heating combustion chamber with an arrangement of burners and process stream heat transfer tubes. Combustion product gases are directed from the combustion chamber through a flue gas convection section where the bulk of the waste heat remaining in such gases is extracted by forced convection against other process and utility streams prior to discharge.
Fundamental elements of furnace design are well known and have changed very little. Efforts to improve furnace efficiency have concentrated on the heat transfer equipment, burner design and arrangement and the combustion process itself. For example, combustion improvements have included adjusting reactant ratios, catalyst and furnace firing of the radiant section.
U.S. Pat. Nos. 4,999,089 to Nakase et al.; 4,706,612 to Moreno et al.; and 4,784,069 to Stark describe typical furnace arrangements of radiant and convection heating sections known in the art. Moreno utilizes gas turbine exhaust to preheat and supplement furnace combustion air. Stark also uses turbine exhaust as a low oxygen source of combustion air for operating a furnace in a fuel-rich method.
The use of gas turbine exhaust as part or all of the combustion air in a furnace results directly in reducing overall fuel requirements. However, the combustion product gases from a furnace operated in this manner are greater in volume, but lower in temperature than flue gas from a conventionally operated furnace. The large volume, low temperature flue gas complicates waste heat recovery because the temperature approaches between the flue gas and the process and/or utility stream being heated are too close to allow efficient or economical heat recovery, if at all.
U.S. Pat. No. 4,665,865 to Zubrod describes a steam generator in which a first flue has an upper end with a cross flue leading to a second flue. The cross flue is formed by an intermediate ceiling in the first flue and two vertical walls made of pipe.
U.S. Pat. No. 3,097,631 to Martin describes a means for controlling the flow of heating gas through the flue of a steam boiler or water heater. Combustion product gases conducted along a switchback main duct path can enter a damper controlled bypass duct having a series of dampers allowing part of the gases to selectively bypass part of the main duct path.
U.S. Pat. No. 2,721,735 to Permann describes a furnace wherein the heating tubes are arranged within a heating zone so as to cause combustion gases to flow longitudinally to the tubes and part of the gases are recirculated to the burners.
Other U.S. Pat. Nos. of interest are 3,426,733 and 3,424,695 to Wiesenthal; and 3,094,391 to Mader.
SUMMARY OF THE INVENTION
The present invention resides, in part, in a furnace design using a split flue gas convection section having parallel flow paths. By splitting flue gas into parallel flow channels, greater control can be exercised over the flue gas temperature for enhancing forced convection heat transfer temperature differentials. For example, the flue gas in one of the channels can be selectively heated with a supplemental burner. This furnace design is particularly advantageous when gas turbine exhaust is used for all or part of combustion air in the furnace since more efficient flue gas heat recovery is achieved.
In one aspect, the present invention provides a process furnace. The furnace has a radiant heating chamber heated by a plurality of burners and housing a plurality of heat transfer tubes. A primary convection section leg housing one or more convection coils is in fluid communication with the radiant chamber to receive flue gas therefrom. A secondary convection section leg split into two or more parallel flow channels, each housing one or more supplemental convection coils, is in fluid communication with the primary convection section leg to receive flue gas therefrom. A discharge manifold duct is in fluid communication with the secondary convection section leg to gather and receive flue gas from the parallel flow channels. One or more dampers are disposed in or between the parallel flow channels to regulate the proportion of the flue gas received through each channel.
A line can connect a gas turbine exhaust to the burners to supply exhaust as all or part of the combustion air. The fresh air can be preheated by a heat exchanger disposed in one of the parallel flow channels. The furnace can include one or more tunnel burners for heating flue gas received from the radiant chamber in the primary convection section leg, one or more convection burners for heating flue gas received from the primary convection section leg in one or more of the parallel flow channels, and an induced draft fan disposed in the discharge manifold for withdrawing flue gas from the secondary convection section leg.
In another aspect, the present invention provides a method for operating a process furnace. The method comprises the steps of: heating a radiant heating chamber housing a plurality of heat transfer tubes with a plurality of radiant section burners; passing flue gas from the radiant heating chamber through a primary convection section leg and recovering heat from the flue gas with one or more primary convection coils disposed in the primary convection section leg; dividing the flue gas from the primary convection section leg for passage through two or more parallel flow channels in a secondary convection section leg; recovering heat from the flue gas in each of the flow channels with supplemental convection coils disposed therein; and gathering flue gas from the parallel flow channels in a discharge manifold.
The heating step can use hot gas turbine exhaust as all or part of combustion air for the radiant section burners. The method can include the steps of heating the flue gas from the radiant heating chamber with one or more tunnel burners and heating the flue gas from the primary convection section leg with one or more convection burners in one or more of the parallel flow channels. The radiant heating chamber preferably has an exit temperature of from about 850° C. to about 1100° C. The primary convection section leg preferably has an operating range from about 350° C. to about 1100° C. The secondary convection section leg preferable has an operating range from about 120° C. to about 900° C., more preferably from about 150° C. to about 750° C. The dividing step can include adjusting a damper disposed in or between the parallel flow channels to regulate the proportion of the flue gas received through each channel.
BRIEF DESCRIPTION OF THE DRAWING
The FIGURE is a flow diagram of an embodiment of the furnace of the present invention having a parallel flow split flue secondary convection section leg.
DETAILED DESCRIPTION OF THE INVENTION
A furnace comprising a split flue, parallel flow secondary convection section leg allows flue gas temperature differentials and flowrates to be adjusted for greater efficiency and design flexibility. In addition, the furnace overcomes the waste heat recovery problem posed by lower temperature flue gas when turbine exhaust is used for combustion air.
Referring to the FIGURE, process furnace F has a radiant chamber R, a primary convection section leg P, and a secondary convection section leg S. The radiant chamber R houses a plurality of burners 10 which can be conventional arch burners suspended from an interior ceiling, for example. A plurality of process heat transfer tubes 12 have an inlet supply line 100 and an outlet supply line 102. The burners 10 are supplied by a fuel feed line (not shown) and a combustion air feed line 104. The burners 10 and tubes 12 preferably alternate in spaced relation in a fashion well known to the art so that a flame produced by the burners 10 does not directly impinge the process tubes 12 or associated fittings. The tubes 12 are heated primarily by radiation from the flame and the hot flue gases. The radiant chamber R preferably has a flue gas exit temperature range of from about 850° C. to about 1100° C., more preferably from about 950° C. to about 1100° C.
The radiant chamber R is in fluid communication with the primary convection section leg P through a connecting duct 14. Within the duct 14, combustion product gases (also referred to as flue gas) produced by the burners 10 travel to the primary convection section leg P. The duct 14 can house one or more tunnel burners 16 supplied with combustion air via line 105 to control the flue gas temperature in accordance with process requirements.
The primary convection section leg P of the furnace F is in fluid communication with the secondary convection section leg S through an intermediate connecting duct 18. The secondary convection section leg S has two (or more) channels C1, C2 for dividing the flow of combustion gases from the primary convection section leg P into a parallel flow orientation through the secondary convection section leg S. Additional parallel flow channels (not shown) can be used as desired. Flue gas from the channels C1, C2 is then preferably recombined in a discharge manifold duct M before discharge from the furnace F. The discharge manifold duct M preferably includes an optional fan 20 to induce a draft through the convection section legs P and S from the furnace F into a discharge stack or flue D.
Flow of the flue gas is regulated between the channels C1, C2 using a damper 22. The damper 22 is preferably disposed in the discharge manifold duct M, but can alternatively be placed in the intermediate duct 18. As another alternative, a damper can be placed in each of the flow channels C1, C2 for independent control, but the single damper 22 is preferred for simplicity. In addition, the channels C1, C2 may include one or more supplemental convection burners 24 to provide supplemental heating of the flue gas. The supplemental convection burner 24 is preferably installed at an inlet 26 of the channel C1. The burner 24 is fed by a fuel line (not shown) and combustion air is supplied from feed line 106. The quantity and location of supplemental convection burners 24 in one or more of the parallel flow channels C1, C2 are design parameters subject to any need to increase the temperature approach to the convection coils.
Heat is recovered from flue gas in the primary convection section leg P by forced convection heat transfer using a plurality of primary convection section coils 28, 30, 32 housed in the primary convection section leg P. Similarly, high temperature secondary convection coils 34, 36 are disposed in channel C1, and low temperature secondary convection coils 38 in channel C2. Various process and/or utility streams are heated for various purposes, including, for example, conducting endothermic reactions, generating utilities such as steam, preheating boiler feed water, preheating air and fuel streams for the furnace, and the like. Heat exchanger placement in the primary convection section leg P is dependent on enthalpy requirements and a required process outlet temperature. Process streams having higher outlet temperature are generally placed in a hotter section of the convection section.
The primary convection section leg P generally has a temperature in the range of from about 350° C. to about 1100° C. The flue gas entering the primary convection section leg P is generally at (or above) the exit temperature from the radiant chamber R, and is cooled as it passes around the primary coils 28, 30, 32 and heats the fluids circulated through the coils 28, 30, 32. In a preferred control scheme, the flue gas is heated in the duct 14 by regulating the fuel and combustion air supplied to the tunnel burner 16 at a rate sufficient so that the fluid being heated in coil 28 (or coils 30 and/or 32) reaches the desired temperature.
The secondary convection section leg S is preferably operated at a temperature in the range of from about 120° C. to about 900° C., more preferably from about 150° C. to about 750° C. The flue gas entering the channel C1 is heated as desired by the supplemental convection burner 24. In a preferred control scheme, the burner 24 is operated to supply sufficient heat so that the fluid being heated in the coil 34 (and/or the coil 36) reaches a temperature established as a set point. The flue gas passing through the channel C2 generally enters at the exit temperature from the primary convection section leg P and is cooled as it flows around and heats fluid passing through the coil 38, e.g. supplemental combustion air for the burners 10, 16 and 24, as in the illustrated embodiment. Thus, the channel C2 is generally operated at a lower temperature than the channel C1 to heat fluids which are not required to be heated to a higher temperature.
The secondary convection section leg S can be further optimized by regulating the proportion of flue gas split between the channels C1 and C2 by means of the damper 22 which can be partially closed to force a higher flue gas flow rate through the channel C2, or opened to allow more flue gas through the channel C1. The driving force for forced convection of the first coils 34 and 38 disposed in each parallel flow channel C1 or C2 is enhanced relative to coils disposed in series in a single channel. Design flexibility of the furnace F is also broadened. The split channel design allows greater control over the operating temperature and enthalpy content of the gases in the flue channels C1, C2. The optional supplemental heating by burner 24 can be accomplished more readily than in prior art furnaces because the flue gas flowrate in the channel C1 can also be adjusted in addition to the amount of supplemental heating or duty of the burner 24.
In a preferred embodiment, exhaust from gas turbines generally obtained from rotary equipment drivers, although having a reduced oxygen content, can be used for all or a portion of the combustion air for the various burners. In this manner, the sensible heat of turbine exhaust can be used to enhance burner efficiency and reduce fuel consumption. Turbine exhaust can have an oxygen content from about 13 to about 19 percent by volume, but an oxygen content of from about 14 to about 16 percent by volume is more usual. The turbine exhaust can be combined with fresh air, preferably preheated, to supplement the overall oxygen content. For example, coil 38 disposed in the parallel flow channel C2 heats supplemental fresh air fed through line 108 by a forced draft fan 40. Preheated fresh air in line 110 is then combined with turbine exhaust from turbine 42 in line 104 to supply combustion air to the burners 10, 16 and 24 via lines 104, 105 and 106, respectively.
The ratio of turbine exhaust to fresh air depends on the oxygen requirement for the burners 10, 16 and 24. Oxygen content, in turn, depends on the desired duty of the radiant chamber R and primary convection section leg P. The temperature of the flue gas without additional heating using burner 24 is, of course, lower when the combustion air oxygen content is maintained at minimum requirements.
The furnace F is made from standard furnace construction materials well known in the art. Since temperatures as high as 1100° C. or greater are typically encountered, structural steel is generally used for the support structure and ducts, and refractory insulation is used to line the combustion chambers.
The furnace F of the present invention is useful in a variety of chemical endothermic reaction processes including steam reforming, hydrocarbon cracking, and the like; for the production of utilities such as steam, boiler feed water, and the like; and for preheating various process streams.
The foregoing description of the invention is illustrative and explanatory thereof. Various changes in the materials, apparatus, and particular parts employed will occur to those skilled in the art. It is intended that all such variations within the scope and spirit of the appended claims be embraced thereby.
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A process furnace and method of operating a furnace are disclosed. The furnace comprises a radiant heating chamber, a primary convection section leg, a secondary convection section leg with two or more parallel flow channels, convection burners to heat the primary and/or secondary convection sections and dampers to adjust flue gas flow and temperature through the parallel flow channels. Combustion air comprising a mixture of gas turbine exhaust and fresh air which has been preheated in one of the parallel flow channels s supplied to the burners. The split flue design facilitates greater control of the flue gas temperature for improved operating efficiency.
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CROSS-REFERENCE
[0001] This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61,994,787 filed May 16, 2014, which is entirely incorporated herein by reference.
BACKGROUND
[0002] Smoking devices, such as cigarette holders and pipes are well known in the art for providing flavored vapor from a smokeable substance to a user for therapeutic and smoking pleasure. However, existing devices used have no control of heating and combustion of the tobacco products. The devices tend to produce toxic, tarry and carcinogenic by-products which are harmful and also impart a bitter and burnt taste to a mouth of a user.
[0003] A further problem is that there is no control of contamination of the inhaled vapor mixture with heater exhaust gases, due to inappropriate proportioning and location of the inlets and the exhaust vents. Typically, the exhaust gas is used to directly heat the tobacco, and those gases contain harmful byproducts of incomplete combustion.
[0004] In an effort to overcome these deficiencies, there is a need for providing a device structure and substance for producing vapor for smoking which is free from harmful by-product and provides a cool and soothing vapor for smoking.
SUMMARY
[0005] The present invention is directed to improvements in smoking devices, particularly to smoking articles which employ a formed smokeable material cartridge as a source of producing vapor by heat transfer to the cartridge by conduction, convection and/or radiation for smoke and flavor. The present invention relates to self-contained vaporization devices, and more particularly, to a low-temperature vaporization device for use with tobacco, botanicals or other smokeable products. The device is of an elongated main body with a mouthpiece at one end and an attached tubular casing at the other end having a vaporization chamber and a heater. The mouthpiece and the casing form a unitary unit. The device can be portable.
[0006] The present invention is drawn to a novel smoking device consisting of a mouthpiece and a casing having a heater, a low temperature vaporization chamber, a fuel tank, an igniter with control means for maintaining equilibrium point by keeping the operating temperature below about 400 F. In some examples, the operating temperature is below 350 about F. In order to maintain a stable operating temperature, a thermal regulator can be used to control flow rate of the fuel.
[0007] Further provided herein is a mouthpiece made of a high temperature food-safe material, such as ceramic, glass, or high temperature plastics known as PEI resin (brand name Ultem). However, suitable plastic or wood, etc., can also be used but may additionally require an insulating material to prevent excessive heat reaching the user's lips.
[0008] Additionally, air inlets are directed downwards, so that fresh ambient air drawn through mixes with the vapor generated into the vaporization chamber located above the smokeable substance cartridge, which is extracted from the cartridge by inlets located below the cartridge and drawn into user's mouth for inhalation.
[0009] It is another object of the invention to provide air inlet or inlets having a diameter and direction sized to admit ambient air into the chamber to heat up the substance and not effect the operating temperature and also regulating the velocity of ambient air entering and mixing with the vapor generated heating in the chamber at such a rate that the proportionate inhalation passage provides a perception to the user as if the smoke is drawn through a cigarette.
[0010] It is still another object of the invention to provide a heater which is separated from the vapor chamber by an insulating medium such as ring made of PTFE, ceramic or other insulating material and thereby preventing the exhaust gases produced by the heater from entering and contaminating the vapor in the vaporization chamber collected for inhalation.
[0011] Another object of the invention provides a heater formed of a conductive shell and a catalyst. The shell may be of one or more material formed by welding or pressing together. The catalyst can be of platinum or palladium impregnated metal or glass or other suitable material, which provides for efficient flameless combustion of the fuel and glows red when heated to indicate that the device is activated. Additionally, a feedback loop can be employed to regulate the desired temperature.
[0012] In some implementations, the smokeable material cartridge may be formed and shaped for easier insertion into the heating chamber and to snugly fit into the cavity of the heating chamber for improved thermal conduction and vaporization. The cartridges may be formed and wrapped into a wrapper. In some implementations, the smokeable material may be provided in a loose form in a pouch. The wrappers and pouches may be formed of a material which does not produce significant amount of harmful gases.
[0013] An aspect of the present disclosure relates to a cartridge fitted in a device, the cartridge comprising a permeable pouch containing a smokeable material, wherein the device is configured to heat the smokeable material in the permeable pouch, and wherein the permeable pouch allows an exit of a vapor generated from the heating of the smokeable material.
[0014] Additional aspects and advantages of the present disclosure will become readily apparent to those skilled in this art from the following detailed description, wherein only illustrative embodiments of the present disclosure are shown and described. As will be realized, the present disclosure is capable of other and different embodiments, and its several details are capable of modifications in various obvious respects, all without departing from the disclosure. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive.
INCORPORATION BY REFERENCE
[0015] All publications, patents, and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated by reference.
BRIEF DESCRIPTION OF DRAWINGS
[0016] The novel features of the invention are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the invention are utilized, and the accompanying drawings or figures (also “FIG.” and “FIGs.” herein), of which:
[0017] FIG. 1 is a side view of a vaporization device.
[0018] FIG. 2 is a sectional view of the vaporization device in FIG. 1 .
[0019] FIG. 3 is a perspective view of a heater.
[0020] FIG. 4 is a cutaway view of an alternate vaporization device.
[0021] FIG. 5 is a sectional detail view of a cartridge.
[0022] FIG. 6 is a perspective view of a cartridge.
[0023] FIG. 7 is a sectional detail view of a cartridge.
[0024] FIG. 8 is a sectional detail view of a cartridge.
[0025] FIG. 9 is an example of a pouch in a vaporization device.
[0026] FIG. 10 is an example of an oven chamber of a device.
DETAILED DESCRIPTION
[0027] Referring to FIG. 1 and FIG. 2 , the exterior of the device 10 comprises a mouthpiece 11 , a tubular case 12 , and the base 14 of a butane tank 21 . The mouthpiece is removable and creates an airtight seal with the interior of the case. With the mouthpiece removed, a cartridge ( FIG. 5 ) is introduced to vaporization chamber 15 of a heater 16 . The mouthpiece is then reinserted to close the device.
[0028] The mouthpiece is made of a high-temperature and food-safe material such as ceramic, glass, or various high-temperature plastics such as PEI resin (brand name Ultem). Design is simplified by use of high temperature materials, but standard plastics or wood, etc, can also be used with the addition of an insulating component that prevents any excessive heat from reaching the user's lips.
[0029] To activate the device, the butane tank is pulled axially outward, partially removing it from the case. This starts the flow of butane by opening a master valve 18 , and then activating a piezoelectric igniter 13 . The tank remains in the partially removed position for the duration of use. While the master valve is open, butane flows through a thermal regulator 17 , and into the carburetor 20 . Ambient air enters the case through slot 19 . A venturi in the carburetor entrains air, causing it to mix with the butane. The mixture then flows into the heater 16 .
[0030] The lead of the ignitor is positioned in the heater. With the spark of the ignitor (immediately following the start of gas flow) the gas ignites and heat starts conducting throughout the heater. Heat transfers to the cartridge by conduction, convection and/or radiation. The cartridge is shaped to fill the chamber, so as to maximize surface contact for thermal conduction.
[0031] As the cartridge heats, vapor generates within the cartridge and in the space immediately above it. When a user draws on the device, fresh air enters through air inlet 22 , mixes with the vapor, and the mixture is delivered to the user via the inhalation passage 23 . The air inlet or inlets can be directed downward, so as to improve the extraction of vapor from the cartridge. They can also be directed along a diagonal through the mouthpiece, or laterally through the case itself, above the cartridge.
[0032] FIG. 3 depicts a detailed view of the heater 16 . The heater comprises a thermally conductive shell 26 and catalyst 27 . The shell can be comprised of one material, or a combination of materials welded or pressed together. The catalyst can be platinum- or palladium-impregnated metal or glass, or other suitable material known to those skilled in the art. The catalyst provides for efficient flame-less combustion of the butane. The vent 28 of the heater is positioned such that it is visible through the slot 29 of the body as shown in FIG. 1 . This allows the user to see the catalyst which, when heated, can glow red to indicate that the device has been activated.
[0033] Referring again to FIG. 3 , adjacent to the heater and in intimate thermal contact is the thermal regulator 17 . As the temperature of the heater increases, so does that of the regulator. The regulator is designed to restrict the flow of butane as the temperature increases, thus creating a feedback loop. The regulator can consist of a bimetallic strip 60 and silicone tubing 61 which is the conduit of the butane. The two are arranged such that as the bimetallic strip heats up, it curls to pinch the silicone tube and thereby restrict the flow of butane. The reduced flow of butane results in less heat generated. The heater subsequently cools down, and so does the regulator, allowing more butane to flow again. The overall result is that a stable operating temperature is established in the heater. Such a system can be readily tuned to achieve an operating temperature that varies by less than +1-5 degrees Fahrenheit.
[0034] The regulator further comprises a moveable backplate 62 which allows adjustability of the operating temperature by adjusting the temperature at which the bimetallic actuator closes the tube valve. This is to be performed once at manufacture, to calibrate the device. Alternatively, a control means may be used to allow the target temperature of the device changed during operation.
[0035] The regulator can comprise in part a bimetallic strip and silicone tubing valve. Alternatively, the regulator can be comprised of other materials and configurations, as described later.
[0036] The desired operating temperature for vaporizing the smokeable materials herein can be below about 400 F. In some cases, the operating range can be below about 350 F. For example, for the purposes of vaporizing most botanicals in this device, the desired operating temperature is below about 400 F, or, in some cases, below about 350 F.
[0037] The air inlet diameter can be sized such that inhalation is somewhat inhibited. This allows time for ambient air entering the chamber to heat up and not affect operating temperature considerably. It also increases velocity of the entering air, which improves circulation and mixing in the vaporization chamber. It also creates a partial vacuum, lowering the vapor point temperature for material contained in the vaporization chamber. The reduction in draw rate can also serve to give the impression of drawing on a cigarette or pipe. Both the fresh air inlet and inhalation passage can be adjusted to provide appropriate draw rate for the operating temperature of the device, and the perception intended for the user.
[0038] Once the cartridge is consumed, the device is turned off by pushing the tank back into the case, closing the master valve. The spent cartridge is removed by opening the device and turning the body over. The cartridge can simply fall out. Alternatively, a mechanism can be used to quickly and easily remove the cartridge. This mechanism can include, but does not require, the use of a pin or slide part to eject the cartridge as another part of the device is moved or removed. The removal mechanism can also involve introduction of a foreign object.
[0039] In some implementations, the mouthpiece may be permanently attached to the body. In that case, the vaporization chamber may be accessed by operating a sliding or hinged door, or similar means, built into the device.
[0040] The heater of the device is fitted into the case with an inslator 24 . The insulator can be made of PEI (brand name Ultem), ceramic, or other insulating material. The insulator serves to minimize thermal transfer from the heater to the case, while creating an air-tight seal. The seal prevents exhaust gases produced by the heater from entering the vaporization chamber. Exhaust gases are instead vented out the case slots. Since the air inlet is distant from the slots, there is substantially no contamination of the inhaled vapor mixture by heater exhaust gases.
[0041] In some implementations, the insulator can be a partially hollow shell, containing a sealed vacuum. In yet other implementations, the heater may be sealed directly to the case by braising in a vacuum furnace, so as to create a vacuum between the two and obviate need for an insulator component.
[0042] The tank can be made of a translucent material. This allows the user to determine the level of fuel remaining by looking at the base of the tank.
[0043] The case can be made of a material that is either a good thermal conductor (such as aluminum), or a poor one (such as ceramics). In both cases, the effect is that the body remains cool enough to touch over a large portion of its surface.
[0044] In one example, a bimetallic actuator can be used in the regulator. In another example, a shape memory alloy actuator such nickel-titanium alloys (“Nitinol”) can be used. In yet another example, a paraffin-filled component that expands and contracts to modulate butane flow can be employed. In a further example, a system can be employed to measure the current temperature, e.g., with a thermocouple sensor and compare it to a prescribed temperature, e.g., with a micro-controller, and by controlling an electromechanical valve, e.g., servo or solenoid valve. In a configuration with user-selected temperature, as described above, the selected temperature can be used as an input to this system.
[0045] A thermal regulator may be used. Alternatively, the device may be constructed without an active regulating element. This may result in reduced complexity and in lowering the overall cost of the device. In this case, the flow of butane is set at a low level. In use, the temperature inside the chamber increases until an equilibrium point where additional heat introduced equals the heat lost to the environment. Heat is lost by conduction through the body of the device, and with the vapor delivered to the user. This equilibrium point determines the operating temperature of the device. By changing the butane flow rate, size and material of the burner, and other factors, the system can be calibrated to provide a fairly stable desired operating temperature.
[0046] An advantage of the bimetallic regulator feedback loop methods over the equilibrium method is that the operating temperature is not dependent on environmental factors such as ambient temperature and wind.
[0047] A piezo-electric ignitor can be used. Other ignitors may be used, such as, a flint starter or battery-powered resistive coil.
[0048] The butane tank may be refillable, and may have a port 25 for that purpose. Alternatively, the tank may be disposable once its fuel is exhausted. A release mechanism such as a pin or cam may be employed allowing the user to quickly remove the depleted tank and replace it with a full one. The replaceable tank may include additional parts of the device including, but not limited to, the ignitor and heater. Butane can be used as the fuel source, but may be replaced by other liquid fuels, such as ethanol.
[0049] Various means of feedback may be used to indicate the following states or metrics of the device: 1) the device is on, 2) the current temperature of the vaporization chamber, 3) the chamber is below a prescribed operating temperature, 4) the chamber has reached a prescribed operating temperature and vapor is ready for consumption, and 5) the chamber has exceeded a prescribed operating temperature.
[0050] The means of the feedback includes both physical and electronic implementations. Possibilities include thermochromatic paint, light-emitting diodes and liquid crystal display. The sensing and control means for electronic feedback can be implemented by use of thermocouple and micro-controller, as is known to those skilled in the art.
[0051] The smokeable materials herein may include, but are not limited to, tobacco, botanicals (e.g., cannabis, chamomile), pharmaceuticals, nutraceuticals, natural or artificial flavorants, coffee grounds or coffee beans, mint, lemon, honey, tea leaves, cocoa, or any other substance providing a benefit or sensation to an end user.
[0052] The smokeable materials herein may be provided in loose leaf form, cut form, shredded form, chopped form, packed form, or any other natural or processed form. As described elsewhere herein, in some examples, the smokeable material may comprise fine pieces of tobacco. In other examples, the smokeable material may comprise loose leaf tobacco. In yet other examples, the smokeable material may comprise loose leaf, shredded or chopped botanicals (e.g., loose leaves, shredded. The smokeable material comprise a vapor forming medium (e.g., glycerin).
[0053] Active elements contained in botanicals may vaporize at different temperatures. The device may be calibrated to establish a single stable temperature, intended for vaporizing solely tobacco or solely chamomile, for example. A control means may be used to select a variety of temperature settings. The user may choose which setting based on the type of cartridge used. The control means can effect a desired temperature mechanically, such as by changing flow rate of the valve, or electronically, such as by electromechanical valve and micro-controller intermediary.
[0054] In some examples, butane may provide the most energy-dense and practical fuel source. In some examples, the butane heating system is replaced by a battery-powered electric heater or other compact heat source.
[0055] FIG. 4 depicts a cutaway view of a vaporization device which more closely resembles a traditional pipe form. In this configuration, the device retains all of the critical elements from the configuration in FIG. 1 . The user inserts a cartridge 40 , under a sliding top piece 41 , where the cartridge mates with the heater 42 . Fuel held in the tank 43 is released by turning dial 44 to open master valve 45 . The fuel travels through the regulator 51 , and then through the carburetor 46 where it draws in air through the intake port 47 and catalyzes in a manner similar to that of the configuration in FIG. 1 . As the cartridge 40 reaches its operating temperature the user places the mouthpiece 48 in their mouth and draws air in through the inhalation intake port 49 and through the vapor passage 50 where it is pre-cooled.
[0056] A cartridge comprising the smokeable material may be fitted in the device 10 . The device can be configured to heat the smokeable material in the cartridge. The device can heat the smokeable material (e.g., in the vaporization chamber) to a temperature required to vaporize the smokeable material. The cartridge can be inserted into the heated vaporization chamber of the device. For example, the device can heat the cartridge to below about 400 F. The cartridge may comprise a wrapper, a permeable pouch or a perforated container.
[0057] In some examples, the smokeable material (e.g., a moist smokeable material that may need to be contained in a wrapper) may be provided in a wrapper. The wrapper may be provided with a perforation that allows an exit of a vapor generated from heating the smokeable material. The perforation may further comprise an aeration well that allows air to access the smokeable material.
[0058] In some examples, the smokeable material (e.g., dry and/or loose smokeable material that may not need to be contained in a wrapper) may be provided in a permeable pouch. The pouch may be permeable to gases (e.g., air, vapor generated from heating the smokeable material, etc.). The permeable pouch may allow air to access the smokeable material. The permeable pouch may allow an exit of a vapor generated from heating the smokeable material. The permeable pouch may eliminate the need to directly expose the smokeable material to the surroundings (e.g., by leaving a portion of the smokeable material exposed, as shown, for example, in FIG. 7 , or by providing perforations, in some cases together with aeration wells, that allow vapor to exit and/or air to enter, as shown, for example, in FIGS. 5, 6 and 8 ). The permeable pouch may eliminate the need to puncture the cartridge. The permeable pouch may be permeable on all surfaces. All surfaces of the permeable pouch may be permeable. The permeable pouch may comprise one or more permeable surfaces. Further, the permeable pouch may enhance air and vapor transport to and from the smokeable material (e.g., by providing air and vapor transfer across a larger surface of the pouch as compared to the vapor transfer available in a cartridge that only has a single or more than one perforations on one or two sides).
[0059] In some examples, the smokeable material (e.g., dry and/or loose smokeable material that may not need to be contained in a wrapper) may be provided in a perforated container. The perforated container may comprise or be formed of a metallic foil (e.g. aluminum, stainless steel, or copper) with a perforation pattern to allow gas transfer through the container. The perforated container may have a perforation pattern on at least one surface of the container. The perforated container may allow air to access the smokeable material. The perforated container may allow an exit of a vapor generated from heating the smokeable material. The perforated container may eliminate the need to directly expose the smokeable material to the surroundings. The perforated container may eliminate the need to puncture the cartridge. Further, the perforated container may enhance air and vapor transport to and from the smokeable material (e.g., by providing air and vapor transfer across a larger surface). The perforated container may comprise or be formed of a thermally conductive material to enhance heat transfer to the smokeable material. The perforated container may be perforated on all surfaces. All surfaces of the perforated container may comprise perforations. The perforated container may comprise one or more perforated surfaces. Further, the perforated container may enhance air and vapor transport to and from the smokeable material (e.g., by providing air and vapor transfer across a larger surface of the container as compared to the vapor transfer available in a cartridge that only has a single or more than one perforations on one side or only on two opposing sides).
[0060] Any aspects of the disclosure described in relation a cartridge comprising a wrapper may equally apply to cartridges comprising a permeable pouch or a perforated container at least in some configurations. Any aspects of the disclosure described in relation a cartridge comprising a permeable pouch may equally apply to cartridges comprising a wrapper or a perforated container at least in some configurations. Any aspects of the disclosure described in relation a cartridge comprising a perforated container may equally apply to cartridges comprising or a wrapper or a permeable pouch at least in some configurations.
[0061] FIG. 5 depicts a sectional view of an example of a cartridge 30 . The cartridge consists of a smokeable material 31 , enclosed in a wrapper 32 , with perforations 33 , and aeration wells 34 . The wrapped cartridge allows for the easy insertion and disposal of smokeable material (e.g., tobacco material, botanicals, or any other smokeable material herein) without creating a mess, while the perforations allow the formed vapor to be released. When the cartridge is used up it can be easily disposed of in its entirety.
[0062] Smokeable material, such as, for example, tobacco or tobacco material, may be any combination of natural and synthetic material that can be vaporized for pleasure or medicinal use. In an example, a test cartridge is prepared using flue-cured tobacco, glycerin, and flavorings. Those skilled in the art of tobacco product manufacture are familiar with these and other ingredients used for cigarettes, cigars, and the like. The cartridge is produced by chopping tobacco into fine pieces (less than 3 mm diameter, preferably less than 2 mm; having no dimension larger than 3 mm, or having substantially all fine pieces be less than 2 mm in all dimensions), adding the other ingredients, and mixing until even consistency is achieved.
[0063] The cartridge may be substantially cylindrical. In other implementations, the form can be modified for various reasons. As an example, the walls of the cartridge may be drafted for easier insertion into the vaporization chamber. Or, the bottom of the cartridge may possess receptacles, which when combined with complimentary features on the surface cavity of the vaporization chamber may allow for more surface contact and hence improved thermal conduction. The wrapper may be formed as a pouch in some implementations.
[0064] Any material may be used for the wrapper, provided that when heated to the operating temperature, it does not produce significant amounts of harmful gases. Aluminum foil and parchment paper are two examples. With papers, the cartridge may be manufactured in a folded-cup design, similar to that shown in FIG. 6 . With films or metal foils, the wrapper can be pressed or blow-molded to the appropriate shape.
[0065] During manufacture, the cartridge may be enclosed on all sides, and perforated on the top so that vapors can emanate upwards. In the perforation step, or in an additional step, the optional aeration wells may be created.
[0066] The cartridge may be wrapped on all sides but leaving the top exposed, as shown in FIG. 7 . This is possible since the purpose of the wrapper is primarily to prevent tobacco material from touching the sides and bottom of the vaporization chamber.
[0067] In another implementation, the material for the top of the cartridge may be vapor permeable, such that perforations are not necessary. As described in greater detail elsewhere herein, cartridges of the disclosure may also be air permeable. Such air and vapor permeable cartridges may advantageously be used to enhance air and vapor transfer along one, two or more (or all) surfaces of the cartridge.
[0068] In another implementation, the cartridge as purchased by the user has no openings, but is punctured prior to insertion into the device, or upon introduction to the vaporization device. The latter can be achieved by adding a hollow puncturing means to the mouthpiece part of the device. For example, the inhalation passage of the mouthpiece can be extended by a hollow tube. When the mouthpiece is reinserted to close the device, it pierces the cartridge previously introduced, and allows a path for vapor to exit to the user.
[0069] In some examples, the tobacco material may be a homogenous mixture. In other examples, there may be two layers, as shown in FIG. 8 . The moist layer 35 has higher content of vapor-forming material than the dry layer 36 , which consists of dry tobacco or other material acting as a filter. The dry layer serves to prevent any liquid from bubbling up and out of the cartridge during heating.
[0070] In some examples, a lower compartment may consist entirely of a vapor-forming medium, such as glycerin. An upper region may consist of the tobacco material to be vaporized, and the two may be separated by a material that only allows the medium to pass in a vapor or gaseous phase. Gore-tex (brand name) is one such material. In use, vapor generated in the lower region may pass through the semi-permeable membrane, volatize the active components of the tobacco, and a mix of the two may be delivered to the user upon inhalation.
[0071] In some implementations, the consistency of the tobacco material is such that the wrapper is not necessary. This is possible if at least the outer surface of the cartridge is dry and cohesive enough to not leave deposits inside the device. Such a cartridge can be made by forming tobacco material in a mold. If the resulting surface is excessively moist, it can be dried by heating the cartridge in an oven.
[0072] The cartridge 30 may comprise a permeable pouch containing a smokeable material, The permeable pouch may comprise cellulose and/or other permeable materials (e.g., other fibers) capable of withstanding the operating temperatures of the device. The permeable pouch may comprise a binding agent or binder (e.g., cellulose acetate fibers). The binding agent or binder may be capable of withstanding the operating temperatures of the device (e.g., during heating of the smokeable material in the permeable pouch) without vaporizing (“off-gassing”). The binding agent may be safe for inhalation by a user. Thus, the permeable pouch may be capable of withstanding the operating temperatures of the device (e.g., during heating of the smokeable material in the permeable pouch) while remaining intact. The permeable pouch may be heat-sealed (e.g., at a temperature of about or exceeding the operating temperature of the device). The permeable pouch may be permeable to air, and/or vapor (e.g., vapor generated from heating the smokeable material). The permeable pouch may contain a given quantity of smokeable material. The given quantity of smokeable material may be chosen based on device dimensions, duration of smoking time, or desired smoke or vapor composition.
[0073] The cartridge 30 may comprise a perforated container containing a smokeable material, The perforated container may comprise a metallic foil with a perforation pattern on at least one surface. The perforated container may be welded shut or the perforated container may comprise a binding agent or binder (e.g., cellulose acetate fibers). The binding agent or binder may be capable of withstanding the operating temperatures of the device (e.g., during heating of the smokeable material in the perforated container) without vaporizing (“off-gassing”). The binding agent may be safe for inhalation by a user. Thus, the perforated container may be capable of withstanding the operating temperatures of the device (e.g., during heating of the smokeable material in the perforated container) while remaining intact. The perforated container may be heat-sealed (e.g., at a temperature of about or exceeding the operating temperature of the device) or welded. The perforated container may allow passage to air, and/or vapor (e.g., vapor generated from heating the smokeable material). The perforated container may contain a given quantity of smokeable material. The given quantity of smokeable material may be chosen based on device dimensions, duration of smoking time, or desired smoke or vapor composition. The perforated container may be formed as a pouch in some implementations.
[0074] FIG. 9 is an example of a pouch 906 containing a smokeable material, fitted in a vaporization device 900 . In this example, the device comprises a body 901 . The device may comprise a mouthpiece 902 with an aerosol outlet 922 , a condenser 903 , a heater 905 , and an oven or vaporization region 904 . The oven region 904 may comprise an oven or vaporization chamber 907 . Air may be drawn into the device through the air inlet 921 by a user puffing on the mouth piece. The pouch 906 may be placed in the oven region 904 , where it may be heated by the heater 905 to generate a vapor or aerosols of the smokeable material. The pouch may comprise a permeable material or a thermally conductive material with a perforation pattern. Permeability of the pouch by means of composition of a permeable material or perforations may improve heat and mass transfer to the smokeable material in the pouch (e.g., eliminate the need for aeration vents in the oven region 904 ).
[0075] FIG. 10 shows an example of an oven region 1000 of a device. The oven region may comprise an oven chamber 1007 designed to fit a cartridge comprising a pouch (e.g., a permeable pouch). The pouch may comprise a permeable material or a thermally conductive material with a perforation pattern. The oven chamber may have a lid 1030 so that the user may access the oven region to insert and remove cartridges. Air may be drawn in to the oven region through an inlet 1021 and exit the oven region through an outlet 1022 . Vapor generated from the heating of the smokeable material in the pouch may exit the oven region through an outlet 1022 . The air may mix with vapor generated from the heating of the smokeable material. The mixing may take place in the oven chamber 1007 , and the combined gas stream may exit through the outlet 1022 . Permeability of the pouch by means of composition of a permeable material or perforations may improve heat and mass transfer to the smokeable material in the pouch (e.g., eliminate the need for aeration vents in the oven region 1000 ).
[0076] In some implementations, devices comprising a vaporization chamber configured to fit a pouch (e.g., as shown in FIGS. 9 and 10 ) may advantageously be used with a pouch that is permeable all around. In some examples, more efficient vapor removal may be achieved with an air path that traverses the pouch, as shown in FIGS. 9 and 10 . In some implementations, greater flexibility for the device design may be realized as a result of improved air flow and vapor removal. For one example, the air inlet 22 in FIG. 2 may be provided on the mouthpiece 11 in an alternative configuration. In another example, the air inlet may be configured separately from the mouthpiece, as shown, for example, in FIG. 9 .
[0077] It is to be understood that the terminology used herein is used for the purpose of describing specific embodiments, and is not intended to limit the scope of the present invention. It should be noted that as used herein, the singular forms of “a”, “an” and “the” include plural references unless the context clearly dictates otherwise. In addition, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.
[0078] While preferable embodiments of the present invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention. It is intended that the following claims define the scope of the invention and that methods and structures within the scope of these claims and their equivalents be covered thereby.
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A smoking device for generating and releasing smoking vapor free from contamination into the mouth of a user comprising a mouthpiece for providing vapor for inhalation to a user including a tubular casing containing a heater for heating a smoking substance at a substantially constant low temperature by regulating the flow of fuel by a thermal regulator and further having means for visual indication of the operation of the device.
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CROSS REFERENCED APPLICATIONS
This application is a File Wrapper Continuation of application Ser. No. 08/128,265 filed Sep. 28, 1993 (now abandoned) which was a File Wrapper Continuation of U.S. application Ser. No. 07/851,333 filed Mar. 16, 1992 (now abandoned), which was a continuation-in-part application of Ser. No. 07/612,239 filed Nov. 5, 1990 (now abandoned).
TECHNICAL FIELD
This invention relates generally to product support packaging inserts and more particularly to ecologically advantageous packing inserts for supporting products within outer shipping cartons and protecting the supported products against external shock.
BACKGROUND OF THE INVENTION
When shipping fragile products, it is desirable to provide protection against external shock which is as complete as possible and, at the same time, minimize both packaging and shipping costs. In the past, both expanded polystyrene (EPS or styrofoam) and polyurethane or polyethylene (flexible foam) inserts have been used for such purposes with considerable success. In recent years, however, environmental concerns over both EPS and flexible foams have been growing. Both are very voluminous per pound and thus tend to exhaust landfill areas much too quickly. Any foamed plastic product is, moreover, both difficult and costly to reclaim or recycle back to its original non-foamed state. There is, therefore, an ongoing need for new packaging techniques which not only provide adequate protection to products against external shock and minimize both packaging and shipping costs but also present minimal ecological problems in the disposal of packaging materials after they have served their intended purpose.
SUMMARY OF THE INVENTION
The present invention generally takes the form of a supporting structure for positioning and supporting a product within an outer packing container. In accordance with a principal aspect of the invention, that structure is self-supporting and is also capable of supporting loads thereon, thus becoming a main supporting element, and further uses a gas such as air as the other main supporting element. In the preferred embodiment, the supporting structure comprises a product specific gas-containing bladder or air bladder with an external cavity on one side or in a first region thereof. The cavity is shaped to fit the external pre-determined configuration and dimensions of the product and with its exterior on the other side or in a second opposed region shaped to fit internal dimensions of the packing container or shipping carton. The air bladder may be either a vertical or a horizontal positioning element and may typically be used in sets of top and bottom pairs within a single outer packing container. The air bladder provides both product support and impact protection during storage and shipping and can be easily collapsed after use. Collapsed, the air bladder is compact and can be re-used indefinitely before it is finally re-cycled, and need not be discarded, thus minimizing environmental impact. Before final assembly for shipping, air bladder materials require relatively little storage space and even formed air bladders can themselves be stored either wholly or partially deflated to save space.
For purposes of this patent application, use of the term "inflated" to refer to gas within an air bladder or other gas-containing bladder shall mean that there is gas within the bladder. The gas may be at ambient pressure (zero gauge pressure), or somewhat above or below zero gauge pressure. Generally, the bladder is not purposely inflated or pressurized above atmospheric pressure, either during manufacture or at the time of use. Correspondingly, the term "deflated" shall mean that the bladder has been collapsed, with a small amount of gas remaining therein. Likewise, semi-inflated or semi-deflated means that the bladder is in a partially collapsed condition with a corresponding amount of gas therein.
In accordance with another aspect of the invention, the air bladder is composed of a plastic resin material such as polyethylene, and is produced by blow molding. Blow molding involves extruding a semi-solid tube of the plastic material into a mold having the product's outer wall shape. After the mold is closed, a jet of air from a nozzle forces the plastic material to expand and contact the metal walls of the mold. The plastic resin is cooled and hardened almost instantly as the mold is kept cool by circulating water through built-in internal cavities. Blow molding is well known and is already the process of choice in the manufacture of many commercial products such as large soft drink bottles, gas cans, and even garbage cans. Use of blow molded plastic material is particularly advantageous environmentally with respect to the present invention in that the materials it makes use of may be recycled with a minimum of cost or inconvenience. There are, furthermore, no environmentally hazardous substances or expansion agents which are used in the manufacturing process. Moreover, the material of the air bladder itself can be made up with virtually 100% recyclable material, due to modern recycling techniques.
In accordance with an important aspect of the invention, the air bladder may contain a plurality of interior chambers or compartments. Such interior chambers, when present, provide location controllable damping by way of separate air shock absorbers in areas such as corners subject to potentially higher impacts. When a passage is provided between one chamber and another, the size of the passage is controlled by baffling and has a direct influence on the rapidity with which those chambers will deflate under load. A high degree of controllable damping is thus provided. Alternatively, multiple air bladder chambers may be entirely sealed from one another in order to provide maximum isolation if needed to meet directional load requirements. When air bladder chambers are sealed from one another in this manner, the blow molding process makes use of a separate inflation nozzle for each chamber. This aspect of the invention adds yet another controllable design element to protective packaging technology, allowing smaller and effective protective packing containers or shipping cartons.
Damping is also realized due to the increased pressure of the gas within the bladder. Special gases such as sulphur hexafluoride may be used to maximize the damping capacity of the gas. Further, damping is also obtained as a result of the resiliency of the plastic that constitutes the air bladder and also from the relatively small amount of elasticity of that plastic. In terms of damping, it is detrimental to have too much elasticity in the plastic material because this amount of elasticity could cause motion to be returned to the product being supported. Other gases that may be used include carbon dioxide, nitrogen, argon and krypton.
In accordance with yet another aspect of the invention, the air bladder may be further inflated with air or other gases as desired either before or after the air bladder has been sealed, and even after assembly of the product and the air bladder within the packing container. The air bladder may thus, when required, be only partially inflated or even fully deflated after manufacture, allowing the air bladder to take up less room during shipping of the air bladder per se and also making final assembly of the product and one or more air bladders within the container easier to accomplish. After final assembly, inflation needles can be forced through the outer container at one or more predetermined inflation points, where they penetrate the designated air bladder chambers and inflate them to designated pressure levels.
The supporting structure is a semi-rigid self supporting monolith that is made from relatively thick polyethylene plastics material or similar, preferably by a blow molding process. The structure has been designed with the properties of typical polyethylene plastics in mind. Polyethylene plastic having a thickness of about 1/32" is resilient and slightly elastic, and is also stiff enough to support an appreciable load if used in a suitably designed load bearing structure.
The load bearing supporting structure must perform the following functions:
support a static vertically oriented load (all or at least a portion the weight of the product);
support a vertically oriented dynamic load due to vertically displaced motion of the product or outer package;
support a horizontally oriented (in the other two dimensions) dynamic load due to horizontally, displaced motion of the product or outer package;
deform so as to cushion the product from high accelerative or decelerative forces, with such deformation being realized over as large a displacement as reasonably possible, so as to minimize the forces transmitted to and therefore absorbed by the product.
The product supporting structure of the present invention has been designed so as to have walls thick enough to support a static load of several pounds so that a product may be supported by the strength of the walls alone, and also to absorb the extra forces caused by dynamic loading.
The product supporting structure of the present invention has also been designed so as to have walls that are thin enough to be at least partially deformable under typical dynamic loading conditions, so that the overall structure will deform and thus absorb the force of the load over a relatively large displacement, at least as large as reasonably possible. Such large displacement deformation helps to minimize the deceleration forces encountered in receiving and supporting a load and in damping the motion of dynamic loading.
The walls must be thin enough to be resiliently and somewhat elastically deformable so that the structure will non-permanently deform under a static or dynamic load caused by the weight of the material and the movement of the material to be absorbed without permanently deforming the material. The elasticity allows the structure to return to its original shape after it has been deformed by a load, within limits. If the walls are too thick, then the structure will not deform by a significant amount, and therefore will not be able to minimize the accelerative or decelerative forces imparted to it. Further, the structure will be less resilient and be more likely to be permanently deformed if it is deformed by at least a certain amount, and will be less likely to elastically return to its original shape.
The invention may be better understood from the following more detailed description of several specific embodiments, taken in the light of the accompanying drawing and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a product supporting vertical end cap air bladder embodying various aspects of the invention;
FIG. 2 is a plan view showing details of the end cap air bladder illustrated in FIG. 1;
FIGS. 2A, 2B, and 2C are cross-sectional views of the end cap air bladder shown in FIG. 2;
FIG. 2D is a side view of the end cap air bladder shown in FIG. 2;
FIG. 3 illustrates product supporting horizontal tray air bladders embodying various aspects of the invention;
FIG. 4 shows an inflation gun suitable for post molding inflation of air bladders embodying various aspects of the invention;
FIG. 4A illustrates tip details of the inflation gun shown in FIG. 4;
FIG. 5 is an exploded isometric view of a further specific embodiment of the present invention showing a discrete product supporting structure cooperating with the corner of a product and the corner of an outer package; and
FIG. 6 is a cross-sectional view of the product supporting structure of FIG. 5.
DETAILED DESCRIPTION
In order to properly understand the present invention, it is necessary to first understand the applied physics of the situation where impact forces would be experienced by the outer package containing the product and also experienced by the supporting structures and the product itself. There are essentially two types of situations. The first situation involves an outer package in motion, which has been impacted by an external object that may or not be moving, and which decelerates the package. The second situation involves a package that may or may not be moving, and which is impacted by an external object that is moving which in turn accelerates the package. The former case is more common in the handling and shipment of packages of goods and typically occurs when a package is dropped. In either case, there is a change of speed of the package and of the product therein.
In the first situation, inertial forces of the product are transmitted to the supports, to the outer package and to the external object. The supporting structure absorbs as much as possible of the forces. The supporting structure transmits a force to the product, which causes the product to decelerate. In the second situation, accelerative forces are transmitted from the external object to the outer package, to the supports and then to the product. The supporting structure absorbs as much as the force as possible. Some of the force is transmitted to the product, which in turn accelerates the product.
In either case, there are forces transmitted to the product, and the product must absorb the energy being transmitted by these forces. If the forces are too high, damage to the product could result. It is therefore necessary to minimize the forces that reach the product so that it will not be damaged.
It must be realized that basically what is happening is that kinetic energy is being transferred to the product. When an outer package is hit by a moving external object, the kinetic energy of the external moving object must be absorbed. When an outer package is dropped and subsequently impacts onto to a surface such as a floor, the kinetic energy of the product inside at the time of the impact must be absorbed from the product by the supporting structure, and so on.
In order to absorb kinetic energy while realizing a minimum amount of force transmitted to the product, it is necessary to distribute the energy absorption over time as much as possible and to keep the acceleration and deceleration of the product as close to constant as possible. In order to accomplish this, it is necessary to, among other things, maximize the displacement over which the acceleration takes place. Thus, a relatively resilient supporting structure is preferable.
In use, when an object is introduced to the supporting structure, the relatively stiff yet resilient plastic that forms the supporting structure supports the initial weight loading of the object placed thereon. As more of the weight of the object is borne by the supporting structure, the weight of the object causes the structure to deform and correspondingly causes the pressure of the gas inside to increase. As the pressure of the gas inside the supporting structure, the gas provides a correspondingly increased support for the load. The structure continues to deform, in a resilient manner, until the resistive force provided by the supporting structure and the increase pressure of the gas therein are equal and opposite to the load thereon equilibrium is reached. In this manner, a relatively large displacement of the supporting structure is possible before equilibrium is reached, which provides relatively low supporting or damping forces for the object being supported.
In a dynamic load situation, the supporting structure and the pressure of the gas therein supports the changing load of a supporting object in a manner analogous to that described immediately above.
If the supporting structure were pressurized to a positive gauge pressure of perhaps 2-5 p.s.i., then the pressure of the gas in the supporting structure would help support the weight of a load placed on the supporting structure virtually as soon as the load is placed thereon. This means that there would be comparatively less displacement of the supporting structure when a load is placed thereon and correspondingly the load would not be damped over as great a distance--that is to say that the energy from the product being supported would be absorbed within a short distance and therefore over a relatively short period of time, which in turn would cause relatively high forces to be transmitted to the product, which may be undesirable.
In comparison if the supporting structure does not have a positive gauge pressure, then the structure would deform for a greater distance after receiving a load, all the while absorbing energy during the deformation due to the resiliency of the plastic. By the time the air pressure was sufficiently high to help support the load, the energy from the placement of the load would already be partially absorbed and correspondingly lower forces would be transmitted to the product.
FIG. 1 illustrates a typical application of the invention. In the protective packaging industry, vertical packaging elements are usually referred to as "end caps", while horizontal packaging elements are usually referred to as "trays". FIG. 1 shows one of a pair of "end caps" which may, for example, be used in the packaging of personal computers. In FIG. 1, an air bladder 11 forming the end cap is shown with a product receiving cavity 13 facing the viewer. Air bladder 11 is product specific in the sense that, once formed, a specific end cap will receive only a product with external dimensions matching the internal dimensions of cavity 13 and will only fit within shipping cartons matching its own external dimensions. Thus, in the illustrated application, the side of a personal computer may fit into the cavities 13 of a pair of air bladder end caps and the entire assembly may be placed in a snug fitting corrugated cardboard box (not shown) which serves as an outer shipping container. As an alternative, for instance when an inner container is desired for housing multiple products, the internal dimensions of cavity 13 may be made to match the external dimensions of that inner container. Such an alternative may be desirable when multiple products are to be packed within a single inner container, which is then given protective support within the outer shipping container. In a broad sense, the filled inner container then becomes the product to be stored or shipped.
As shown in FIG. 1, product receiving cavity 13 in air bladder 11 is bounded by four respective corner elements 15, 17, 19, and 21 and by two respective side walls 23 and 25. Although many examples of air bladder 11 will have corner elements, the need for side walls will depend a good deal upon the specific application. A relatively large product may, for example, require side walls between corner elements 15 and 17 and between corner elements 19 and 21. A relatively small product, on the other hand, may not require even the presence of side walls 23 and 25.
Air bladder 11 in FIG. 1 is, in accordance with an important aspect of the invention, composed of a suitable plastic resin material, such as polyethylene, and is produced by a blow molding process to form the illustrated end cap. In that process, a semi-solid tube of the plastic resin material is extruded into a mold that has the shape of the product's outer wall. In the instance illustrated, the shape is that of the outer wall of a personal computer. After the mold is closed, a blast of high pressure air through one or more holes in the wall of the mold forces the plastic tube to expand and contact the metal walls of the mold. The plastic resin then cools and hardens as the mold is cooled by circulating water through internal cavities in the mold. In an application such as that illustrated in FIG. 1, air bladder end cap 11 is pressurized during the blow molding process to a gauge pressure of about 3 to 5 pounds per square inch.
FIG. 2 is a plan view of end cap air bladder 11 of FIG. 1 with the side of air bladder 11 forming cavity 13 shown facing the viewer. FIG. 2 illustrates several details not shown in FIG. 1, one being the division of air bladder 11 into two separately sealed main chambers 27 and 29, bounded by the exterior dimensions of the air bladder and by side walls 31 and 33, which are indicated by respective dashed lines. Chambers 27 and 29 are thus separated from one another in the vertical plane because of the vertical orientation of air bladder 11. Without the separation, the weight of the product (a computer in this instance) would compress the air in lower chamber 29 into upper chamber 27, resulting in a partial collapse of lower side wall 25 and lower corner elements 17 and 21.
Although main chambers 27 and 29 within air bladder 11 in FIG. 2 are sealed from one another, the invention makes it possible to provide sub-chambers within main chambers. Such sub-chambers are partially segregated from other chambers in order to provide a controllable shock damping effect. Examples of such sub-chambers are corner elements 15, 17, 19, and 21 in FIG. 2. Corner element 15 is molded to be a corner baffling sub-chamber, defined by the outer walls of air bladder 11 and by fingers or protrusions 35 and 37 extending from the outside of air bladder 11 into the interior until they nearly contact one another. The gap 39 left between protrusions 35 and 37 permits the passage of air between the corner baffling chamber and main chamber 27 but only at a relatively slow rate. The degree of isolation of the sub-chamber forming corner element 15 is controlled by the size of gap 39.
As shown in FIG. 2, remaining corner elements 17, 19, and 21 are similarly constructed and provide corner baffling sub-chambers which operate in a similar manner. Extra shock protection is provided in this manner at respective corners of the ultimate shipping package. In the interest of clarity, reference numerals 35, 37, and 39 are used to denote corresponding components in all four corner elements in FIG. 2.
FIG. 2A is cross-sectional view of air bladder 11 in FIG. 2, taken along the line A--A, which is broken at the center in order to show details of both exterior and interior construction. Recess 41 in FIG. 2A marks the end of side walls 31 and 33 separating upper and lower chambers 27 and 29. The matching recesses 38 mark the ends of the similarly numbered protrusions into those chambers to provide restricted air flow between upper and lower chambers 27 and 29 and their respective ones of corner sub-chamber elements 19 and 21.
FIG. 2B is another cross-sectional view of air bladder 11 in FIG. 2, this time taken along the line B--B. Here, dividing walls 31 and 33 are farthest apart from one another. Portions of upper and lower chambers 27 and 29 are shown, as is recess 41 at the other end of air bladder 11.
FIG. 2C is yet another cross-sectional view of air bladder 11, this time taken along the line C--C. Here, the ends of protrusions 35 and 37 into the interior of air bladder 11 are shown, along with gap 39 which is provided between them to provide for the restricted flow of air needed for corner damping.
FIG. 2D, finally, is a side view of air bladder 11, with side wall 25 and corner elements 17 and 21 facing the viewer. Dashed lines 43 marks the bottom and ends of product supporting cavity 13 of air bladder 11.
FIG. 3 illustrates another typical application of the invention, this time providing horizontal trays for packaging a product such as a television set. In FIG. 3, a first air bladder 51 forms an upper tray and a second air bladder 53 a lower tray. The two air bladder trays provide respective top and bottom support for a product 55 (shown by dashed lines) within a corrugated cardboard outer shipping container 57 (also shown by dashed lines). Air bladder trays 51 and 53 are shown as mirror images of one another in this particular example, for purposes of clarity, but need not be identical as a general proposition.
In FIG. 3, holes 59 and 61 are an example of a number of holes extending entirely through respective air bladder trays 51 and 53 to constrict the passage of air between various sections of their single main interior chambers by forming sub-chambers. Protrusions 63 and 65, similarly, are examples of protrusions extending partially into respective air bladder trays 51 and 53 both from the exterior of the air bladders and from the product supporting cavities to perform a similar purpose. In FIG. 3, a product supporting cavity 67 in lower air bladder tray 53 faces up, while a similar product supporting cavity (not seen) in upper air bladder tray 51 faces downward.
In a horizontal application of the invention such as that shown in FIG. 3, it is sometimes advantageous to manufacture respective air bladder trays 51 and 53 initially slightly deflated. Such slight deflation simplifies the packing process in that the deflated and hence slightly undersized air bladders will more easily fit into corrugated cardboard outer container 57. After product 55 and the two slightly deflated air bladder trays 51 and 53 are installed within container 57 and container 57 is sealed, air bladder trays 51 and 53 may be further inflated directly through corrugated cardboard container 57 with an inflation gun, an example of which is shown in FIG. 4.
In FIG. 4, an inflation gun 71 is essentially an air valve connected to a hollow needle upon which there is a small heater element installed within a gun tip 73. Inflation gun 71 is connected to a regulated air supply (not shown) through an air line 75, and to a variable power source (not shown) through a power line 77 to control the needle temperature. A trigger mechanism 79 on the handle of gun 71 provides the user with on-off control and a heat adjust knob 81 (also on the handle) permits accurate control of the heater element within gun tip 73. An air pressure gauge 83 and a heat gauge 85 complete the combination.
Details of inflation gun tip 73 in FIG. 4 are shown in FIG. 4A. Gun tip 73 is composed of a neoprene bellows 87 which surrounds a hollow air and heater needle 89 and a heater coil 91. Heater coil 91 encircles the base of needle 89 and bellows 87 compresses upon itself to expose needle 89 when the user presses the gun against an intended target such as outer container 57 in FIG. 3.
In practice, when in the idle mode, needle 89 in FIG. 4A remains at a temperature approximately ten percent higher than the melting temperature of the plastic air bladder material. Outer packing container 57 in FIG. 3 may have pre-printed inflation point instructions and markings of locations where the needle is to be forced through corrugated cardboard container 57 and into the air bladder. By way of example, in the areas where the extruded plastic tube is pinched off and sealed, the air bladder walls are often three to four times thicker than the walls of the rest of the bladder. Such areas, generally, are good post-assembly inflation points. Pressing trigger 79 in FIG. 4, will inflate the bladder to preset pressure level. In order to keep needle 89 from continuing to melt the bladder and creating an oversize opening during the five to ten second filing time, incoming air is relied upon to drop the temperature of needle 89 quickly below the melting point of the plastic bladder material. Once the preset pressure is reached and incoming air stops, needle 89 quickly cycles back up to temperature, allowing it to remelt the plastic to ease its withdrawal. As needle 89 withdraws, internal bladder pressure pushes some of the melted plastic into the hole left by the needle and reseals the bladder.
Upon final disassembly when the shipped product reached its destination, graphic instructions on the bladder itself may be used to instruct the consumer to puncture the bladder for easy removal of the product as well as to provide either general or specific disposal and recycling instructions.
Reference will now be made to FIG. 5, which shows an alternative embodiment of the present invention. In this alternative embodiment, a supporting structure 100 is used to position and support a product 102 within an outer packing container 104. Typically, a total of eight such supporting structures 100 would be used, one in each corner of the product 102. The product supporting structure 100 supports the product 102 at a predetermined portion thereof. The supporting structure 100 has a predetermined configuration and predetermined dimensions such that it supports the product at the predetermined portion--which is of a predetermined configuration. Further, the outer packing container 104 has a predetermined configuration, with the supporting structure 100 to be placed at a predetermined portion thereof.
When in use in combination with the product 102 and the outer packing container 104, the supporting structure comprises a gas-containing bladder 110 that has a product receiving portion 112 in a first region of the gas-containing bladder 110. The product receiving portion 112 has a predetermined configuration and dimensions so as to be co-operative with the predetermined portion of the product 102 and so as to receive in generally intimate and co-operating relation thereto the predetermined configuration of the predetermined portion of the product 102. The predetermined configuration and dimensions of the supporting structure 100 are adapted to fit the predetermined configuration of the predetermined portion of the product. Typically, the predetermined portion of the product is a portion of a corner of the product 102.
The gas-containing bladder 110 has a package containing portion 114 in a second region thereof. The second region is remote from and generally opposed to the first region. The package containing portion 114 is such as to be co-operative with the predetermined configuration of the outer packing container 104.
The supporting structure 100 has a predetermined size and shape when it is manufactured. The supporting structure 100 is typically manufactured with an opening 116 therein. A plug 118 is adapted to fit into the opening in sealed relation thereto and is inserted therein either immediately after manufacture or just before use. Thus, a sealable opening into the gas-containing bladder 110 is provided. When the plug 118 is in place, the gas-containing bladder 110 is sealed to its ambient surroundings. For shipping purposes, the supporting structure may be shipped without the plug in, in which case it is somewhat collapsible if necessary, or it may be shipped with the plug 118 in the opening 116. The supporting structure 100 retains its size and shape when the gauge pressure of the gas within the gas-containing bladder 100 is zero, irrespective of whether the gas-containing bladder 110 is sealed or open to the ambient surroundings.
The supporting structure 100 is capable of supporting a load thereon even when the interior of the gas-containing bladder 110 is in fluid communication with the ambient surroundings.
The gas-containing bladder 110 may be sealed so as to have a gauge pressure of the gas therein that is about zero. This will allow for relatively soft cushioned damping of the product 102. It is also possible to pressurize the gas-containing bladder 110 to a gauge pressure above zero, typically within a range of about 0.01 to about 2.0 atmospheres. Such additional gas pressure would cause the air bladder 110 to provide firmer damping for the product 102.
In a further alternative embodiment of the invention, the predetermined configuration and dimensions of the supporting structure 100 may be adapted to fit a predetermined configuration of a predetermined portion of a product, with the predetermined portion of the product being an edge of the product. For example, a long slender item may be supported at its centre, or a plate or a drum at selected places around its circumference.
Preferably, the supporting structure 100 is made of a plastics material having an average wall thickness in the order of about 1/32 of an inch. The material that forms the supporting structure 100 can be chosen from the group consisting of polyethylene, polypropylene, and co-polymers thereof; as well as vinyl, polyvinylchloride, or nylon. The gas within the gas-containing bladder 110 is most commonly air, but also may be chosen from the group consisting of nitrogen, carbon dioxide, sulphur hexafluoride, argon and krypton.
The gas-containing bladder 110 may comprise a plurality of discrete chambers therein, with the discrete chambers being in fluid communication with one another through small openings, which are means for restricting gas flow between chambers. These openings allow a small amount of gas to pass therethrough in a given time, thereby providing a baffling effect which ultimately aids in the cushioning effect provided by the gas-containing bladder 110. Preferably, contiguous chambers within the gas-containing bladder are in fluid communication with one another.
Reference will now be made to FIG. 6 which shows the supporting structure 100 of the present invention having the product 102 placed thereon. It can be seen that the portion of the product 102 that is supported by the supporting structure 100 is a somewhat complicated shape, and the predetermined configuration and dimensions of the supporting structure are adapted to fit to the predetermined configuration of the predetermined portion of this product. When the product 102 is placed on the supporting structure 100, there is a static force, indicated by arrow 120, which of course is in a downward direction. This static force 120 causes the supporting structure 100 to deform somewhat as shown by the dash lines 122. If, as usual, the gas-containing bladder 110 is sealed, then the deformation causes an increase in pressure of the gas within the gas-containing bladder 110.
It is to be understood that the embodiments of the invention which have been described are illustrative. Numerous other arrangements and modifications may be readily devised by those skilled in the art without departing from the spirit and scope of the invention.
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A supporting structure for positioning a product within an outer shipping container takes the form of a plastic air bladder shaped on one side to provide a cavity having internal dimensions matching external dimensions of the product and shaped on the other to have external dimensions matching internal dimensions of the shipping container. The air bladder may be either a vertical or a horizontal positioning elements and is typically used in pairs within a single container. The air bladder is compact and can be discarded after use with minimal environment impact. In examples shown, the air bladder is of a plastic material such as polyethylene and is produced by blow molding, making it particularly suitable for disposal after use by a recycling process, thereby further reducing potential environmental impact.
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BACKGROUND OF THE INVENTION
It is highly desirable for tires to exhibit good traction characteristics on both dry and wet surfaces. However, it has traditionally been very difficult to improve the traction characteristics of a tire without compromising its rolling resistance and tread wear. Low rolling resistance is important because good fuel economy is virtually always an important consideration. Good tread wear is also an important consideration because it is generally the most important factor which determines the life of the tire.
The traction, tread wear and rolling resistance of a tire is dependent to a large extent on the dynamic viscoelastic properties of the elastomers utilized in making the tire tread. In order to reduce the rolling resistance of a tire, rubbers having a high rebound have traditionally been utilized in making the tire's tread. On the other hand, in order to increase the wet skid resistance of a tire, rubbers which undergo a large energy loss have generally been utilized in the tire's tread. In order to balance these two viscoelastically inconsistent properties, mixtures of various types of synthetic and natural rubber are normally utilized in tire treads. For instance, various mixtures of styrene-butadiene rubber and polybutadiene rubber are commonly used as a rubber material for automobile tire treads. However, such blends are not totally satisfactory for all purposes.
Rubbers having intermediate glass transition temperatures (-70° C. to -40° C.) compromise rolling resistance and treadwear without significantly increasing traction characteristics. For this reason, blends of rubbers having low glass transition temperatures and rubbers having high glass transition temperatures are frequently utilized to attain improved traction characteristics without significantly compromising rolling resistance or treadwear. However, such blends of rubbers having low glass transition temperatures and rubbers having high glass transition temperatures exhibit poor processability. This major disadvantage associated with such blends has greatly hampered their utilization in making tire tread compounds.
Tin-coupled polymers are known to provide desirable properties, such as improved treadwear and reduced rolling resistance, when used in tire tread rubbers. Such tin-coupled rubbery polymers are typically made by coupling the rubbery polymer with a tin coupling agent at or near the end of the polymerization used in synthesizing the rubbery polymer. In the coupling process, live polymer chain ends react with the tin coupling agent thereby coupling the polymer. For instance, up to four live chain ends can react with tin tetrahalides, such as tin tetrachloride, thereby coupling the polymer chains together.
SUMMARY OF THE INVENTION
This invention relates to a tire tread compound that is easily processable which can be used to improve the treadwear, rolling resistance and traction characteristics of tires. The tire tread compounds of this invention are a blend of tin-coupled polybutadiene, high vinyl polybutadiene and natural rubber. This blend of low glass transition temperature rubber and high glass transition temperature rubber is surprisingly easy to process which makes the concept of this invention commercially feasible. Thus, the tire tread compounds of this invention can be utilized in making tires having greatly improved traction characteristics and treadwear without sacrificing rolling resistance. These improved properties may be due, in part, to better interaction and compatibility with carbon black and/or silica fillers. The polybutadiene in the blend can be asymmetrically tin-coupled to further improve the cold flow characteristics of the rubber blend. Asymmetrical tin coupling in general also leads to better processability and other beneficial properties.
This invention more specifically discloses a tire tread rubber composition which is comprised of (1) from about 20 phr to about 60 phr of tin-coupled polybutadiene rubber, (2) from about 20 phr to about 60 phr of a rubber selected from the group consisting of natural rubber and synthetic polyisoprene and (3) from about 5 phr to about 40 phr of high vinyl polybutadiene rubber.
It is normally preferred for the tin-coupled polybutadiene rubber to be asymmetrically tin-coupled. In such cases, the stability of blends containing asymmetrical tin-coupled polybutadiene rubber can be improved by adding a tertiary chelating amine thereto subsequent to the time at which the tin-coupled rubbery polymer is coupled. N,N,N',N'-tetramethylethylenediamine (TMEDA) is a representative example of a tertiary chelating amine which is preferred for utilization in stabilizing the polymer blends of this invention.
DETAILED DESCRIPTION OF THE INVENTION
The tire tread rubber compositions of this invention are comprised of (1) from about 20 phr to about 60 phr of tin-coupled polybutadiene rubber, (2) from about 20 phr to about 60 phr of a rubber selected from the group consisting of natural rubber and synthetic polyisoprene and (3) from about 5 phr to about 40 phr of high vinyl polybutadiene rubber. These tire tread rubbers will typically contain from about 25 phr to about 55 phr of the tin-coupled polybutadiene rubber, from about 25 phr to about 55 phr of the rubber selected from the group consisting of natural rubber and synthetic polyisoprene and from about 10 phr to about 30 phr of the high vinyl polybutadiene rubber. It is normally preferred for the tire tread rubber to contain from about 30 phr to about 50 phr of the tin-coupled polybutadiene rubber, from about 30 phr to about 50 phr of the rubber selected from the group consisting of natural rubber and synthetic polyisoprene and from about 15 phr to about 25 phr of the high vinyl polybutadiene rubber.
The high vinyl polybutadiene rubber employed in the blends of this invention will normally have a glass transition temperature which is within the range of about -40° C. to +40° C. and a Mooney ML 1+4 viscosity which is within the range of about 30 to about 100. The high vinyl polybutadiene rubber employed in the blends of this invention will preferably have a glass transition temperature which is within the range of about -35° C. to 0° C. and a Mooney ML 1+4 viscosity which is within the range of about 40 to about 90. The high vinyl polybutadiene rubber employed in the blends of this invention will preferably have a glass transition temperature which is within the range of about -30° C. to -20° C. and a Mooney ML 1+4 viscosity which is within the range of about 60 to about 80.
The tin-coupled polybutadiene will typically have a Mooney ML 1+4 viscosity which is within the range of about 5 to about 40 before coupling and a Mooney ML 1+4 viscosity of about 60 to about 120 after coupling. The tin-coupled polybutadiene will preferably have a Mooney ML 1+4 viscosity which is within the range of about 5 to about 35 before coupling and a Mooney ML 1+4 viscosity of about 75 to about 110 after coupling. The tin-coupled polybutadiene will most preferably have a Mooney ML 1+4 viscosity which is within the range of about 10 to about 30 before coupling and a Mooney ML 1+4 viscosity of about 80 to about 100 after coupling.
The tin-coupled polybutadiene will typically be prepared by reacting "living" polybutadiene having lithium end groups with a tin halide, such as tin tetrachloride. This coupling step will normally be carried out as a batch process. However, it is generally preferred to tin-couple the polybutadiene in a continuous process which results in the formation of asymmetrically tin-coupled polybutadiene rubber. A technique for producing asymmetrically tin-coupled polybutadiene rubber is disclosed in U.S. Provisional Patent Application Ser. No. 60/037,929, filed on Feb. 14, 1997. The teachings of U.S. Provisional Patent Application Ser. No. 60/037,929 are hereby incorporated herein by reference in their entirety.
The tin coupling agent employed in making asymmetrically tin-coupled polybutadiene rubber will normally be a tin tetrahalide, such as tin tetrachloride, tin tetrabromide, tin tetrafluoride or tin tetraiodide. However, tin trihalides can also optionally be used. In cases where tin trihalides are utilized, a coupled polymer having a maximum of three arms results. To induce a higher level of branching, tin tetrahalides are normally preferred. As a general rule, tin tetrachloride is most preferred.
Broadly, and exemplary, a range of about 0.01 to 4.5 milliequivalents of tin coupling agent is employed per 100 grams of the rubbery polymer. It is normally preferred to utilize about 0.01 to about 1.5 milliequivalents of the tin coupling agent per 100 grams of polymer to obtain the desired Mooney viscosity. The larger quantities tend to result in production of polymers containing terminally reactive groups or insufficient coupling. One equivalent of tin coupling agent per equivalent of lithium is considered an optimum amount for maximum branching. For instance, if a tin tetrahalide is used as the coupling agent, one mole of the tin tetrahalide would be utilized per four moles of live lithium ends. In cases where a tin trihalide is used as the coupling agent, one mole of the tin trihalide will optimally be utilized for every three moles of live lithium ends. The tin coupling agent can be added in a hydrocarbon solution, e.g., in cyclohexane, to the polymerization admixture in the reactor with suitable mixing for distribution and reaction.
After the tin coupling has been completed, a tertiary chelating alkyl 1,2-ethylene diamine can optionally be added to the polymer cement to stabilize the tin-coupled rubbery polymer. This technique for stabilization of the tin-coupled rubber is more fully described in U.S. Pat. No. 5,739,182, filed on Jan. 31, 1997. The teachings of U.S. Pat. No. 5,739,182 are incorporated herein by reference in their entirety. The tertiary chelating amines which can be used for stabilization are normally chelating alkyl diamines of the structural formula: ##STR1## wherein n represents an integer from 1 to about 6, wherein A represents an alkane group containing from 1 to about 6 carbon atoms and wherein R 1 , R 2 , R 3 and R 4 can be the same or different and represent alkane groups containing from 1 to about 6 carbon atoms. The alkane group A is the formula .paren open-st.CH 2 .paren close-st. m wherein m is an integer from 1 to about 6. The alkane group will typically contain from 1 to 4 carbon atoms (m will be 1 to 4) and will preferably contain 2 carbon atoms. In most cases, n will be an integer from 1 to about 3 with it being preferred for n to be 1. It is preferred for R 1 , R 2 , R 3 and R 4 to represent alkane groups which contain from 1 to 3 carbon atoms. In most cases, R 1 , R 2 , R 3 and R 4 will represent methyl groups.
A sufficient amount of the chelating amine should be added to complex with any residual tin coupling agent remaining after completion of the coupling reaction. In most cases, from about 0.01 phr (parts by weight per 100 parts by weight of dry rubber) to about 2 phr of the chelating alkyl 1,2-ethylene diamine will be added to the polymer cement to stabilize the rubbery polymer. Typically, from about 0.05 phr to about 1 phr of the chelating alkyl 1,2-ethylene diamine will be added. More typically, from about 0.1 phr to about 0.6 phr of the chelating alkyl 1,2-ethylene diamine will be added to the polymer cement to stabilize the rubbery polymer.
After the polymerization, asymmetrical tin coupling and optionally the stabilization step, has been completed, the tin-coupled rubbery polymer can be recovered from the organic solvent utilized in the solution polymerization. The tin-coupled rubbery polymer can be recovered from the organic solvent and residue by means such as decantation, filtration, centrification and the like. It is often desirable to precipitate the tin-coupled rubbery polymer from the organic solvent by the addition of lower alcohols containing from about 1 to about 4 carbon atoms to the polymer solution. Suitable lower alcohols for precipitation of the rubber from the polymer cement include methanol, ethanol, isopropyl alcohol, normal-propyl alcohol and t-butyl alcohol. The utilization of lower alcohols to precipitate the tin-coupled rubbery polymer from the polymer cement also "kills" any remaining living polymer by inactivating lithium end groups. After the tin-coupled rubbery polymer is recovered from the solution, steam-stripping can be employed to reduce the level of volatile organic compounds in the tin-coupled rubbery polymer.
The asymmetrical tin-coupled polybutadiene rubber that can be employed in the blends of this invention are comprised of a tin atom having at least three polybutadiene arms covalently bonded thereto. At least one of the polybutadiene arms bonded to the tin atom has a number average molecular weight of less than about 40,000 and at least one of the polybutadiene arms bonded to the tin atom has a number average molecular weight of at least about 80,000. The ratio of the weight average molecular weight to the number average molecular weight of the asymmetrical tin-coupled polybutadiene rubber will also normally be within the range of about 2 to about 2.5.
The asymmetrical tin-coupled polybutadiene rubber that can be utilized in the blends of this invention is typically of the structural formula: ##STR2## wherein R 1 , R 2 , R 3 and R 4 can be the same or different and are selected from the group consisting of alkyl groups and polybutadiene arms (polybutadiene rubber chains), with the proviso that at least three members selected from the group consisting of R 1 , R 2 , R 3 and R 4 are polybutadiene arms, with the proviso that at least one member selected from the group consisting of R 1 , R 2 , R 3 and R 4 is a low molecular weight polybutadiene arm having a number average molecular weight of less than about 40,000, with the proviso that at least one member selected from the group consisting of R 1 , R 2 , R 3 and R 4 is a high molecular weight polybutadiene arm having a number average molecular weight of greater than about 80,000, and with the proviso that the ratio of the weight average molecular weight to the number average molecular weight of the asymmetrical tin-coupled polybutadiene rubber is within the range of about 2 to about 2.5. It should be noted that R 1 , R 2 , R 3 and R 4 can be alkyl groups because it is possible for the tin halide coupling agent to react directly with alkyl lithium compounds which are used as the polymerization initiator.
In most cases, four polybutadiene arms will be covalently bonded to the tin atom in the asymmetrical tin-coupled polybutadiene rubber. In such cases, R 1 , R 2 , R 3 and R 4 will all be polybutadiene arms. The asymmetrical tin-coupled polybutadiene rubber will often contain a polybutadiene arm of intermediate molecular weight as well as the low molecular weight arm and the high molecular weight arm. Such intermediate molecular weight arms will have a molecular weight which is within the range of about 45,000 to about 75,000. It is normally preferred for the low molecular polybutadiene arm to have a molecular weight of less than about 30,000, with it being most preferred for the low molecular weight arm to have a molecular weight of less than about 25,000. It is normally preferred for the high molecular polybutadiene arm to have a molecular weight of greater than about 90,000, with it being most preferred for the high molecular weight arm to have a molecular weight of greater than about 100,000.
The tire tread rubber compositions of this invention can be compounded utilizing conventional ingredients and standard techniques. For instance, these tire tread rubber blends will typically be mixed with carbon black and/or silica, sulfur, fillers, accelerators, oils, waxes, scorch inhibiting agents and processing aids. In most cases, the rubber blend will be compounded with sulfur and/or a sulfur-containing compound, at least one filler, at least one accelerator, at least one antidegradant, at least one processing oil, zinc oxide, optionally a tackifier resin, optionally a reinforcing resin, optionally one or more fatty acids, optionally a peptizer and optionally one or more scorch inhibiting agents. Such blends will normally contain from about 0.5 to 5 phr (parts per hundred parts of rubber by weight) of sulfur and/or a sulfur-containing compound with 1 phr to 2.5 phr being preferred. It may be desirable to utilize insoluble sulfur in cases where bloom is a problem.
At least some silica will be utilized in the blend as a filler. The filler can, of course, be comprised totally of silica. However, in some cases, it will be beneficial to utilize a combination of silica and carbon black as the filler. Clays and/or talc can be included in the filler to reduce cost. The blend will also normally include from 0.1 to 2.5 phr of at least one accelerator with 0.2 to 1.5 phr being preferred. Antidegradants, such as antioxidants and antiozonants, will generally be included in the tread compound blend in amounts ranging from 0.25 to 10 phr with amounts in the range of 1 to 5 phr being preferred. Processing oils will generally be included in the blend in amounts ranging from 2 to 100 phr with amounts ranging from 5 to 50 phr being preferred. The polybutadiene blends of this invention will also normally contain from 0.5 to 10 phr of zinc oxide with 1 to 5 phr being preferred. These blends can optionally contain from 0 to 10 phr of tackifier resins, 0 to 10 phr of reinforcing resins, 1 to 10 phr of fatty acids, 0 to 2.5 phr of peptizers and 0 to 1 phr of scorch inhibiting agents.
To fully realize the total advantages of the blends of this invention, silica will normally be included in the tread rubber formulation. The processing of the rubber blend is normally conducted in the presence of a sulfur containing organosilicon compound to realize maximum benefits. Examples of suitable sulfur-containing organosilicon compounds are of the formula:
Z-Alk-S.sub.n -Alk-Z (1)
in which Z is selected from the group consisting of ##STR3## where R 1 is an alkyl group of 1 to 4 carbon atoms, cyclohexyl or phenyl; wherein R 2 is alkoxy of 1 to 8 carbon atoms or cycloalkoxy of 5 to 8 carbon atoms; and wherein Alk is a divalent hydrocarbon of 1 to 18 carbon atoms and n is an integer of 2 to 8.
Specific examples of sulfur-containing organosilicon compounds which may be used in accordance with the present invention include: 3,3'-bis(trimethoxysilylpropyl)disulfide, 3,3'-bis(triethoxysilylpropyl)tetrasulfide, 3,3'-bis(triethoxysilylpropyl)octasulfide, 3,3,'-bis(trimethoxysilylpropyl)tetrasulfide, 2,2'-bis(triethoxysilylethyl)tetrasulfide, 3,3'-bis(trimethoxysilylpropyl)trisulfide, 3,3'-bis(triethoxysilylpropyl)trisulfide, 3,3'-bis(tributoxysilylpropyl)disulfide, 3,3'-bis(trimethoxysilylpropyl)hexasulfide, 3,3'-bis(trimethoxysilylpropyl)octasulfide, 3,3'-bis(trioctoxysilylpropyl)tetrasulfide, 3,3'-bis(trihexoxysilylpropyl)disulfide, 3,3'-bis(tri-2"-ethylhexoxysilylpropyl)trisulfide, 3,3'-bis(triisooctoxysilylpropyl)tetrasulfide, 3,3'-bis(tri-t-butoxysilylpropyl)disulfide, 2,2'-bis(methoxy diethoxy silyl ethyl)tetrasulfide, 2,2'-bis(tripropoxysilylethyl)pentasulfide, 3,3'-bis(tricyclonexoxysilylpropyl)tetrasulfide, 3,3'-bis(tricyclopentoxysilylpropyl)trisulfide, 2,2'-bis(tri-2"-methylcyclohexoxysilylethyl) tetrasulfide, bis(trimethoxysilylmethyl)tetrasulfide, 3-methoxy ethoxy propoxysilyl 3'-diethoxybutoxysilylpropyltetrasulfide, 2,2'-bis(dimethyl methoxysilylethyl)disulfide, 2,2'-bis(dimethyl sec.butoxysilylethyl)trisulfide, 3,3'-bis(methyl butylethoxysilylpropyl)tetrasulfide, 3,3'-bis(di t-butylmethoxysilylpropyl)tetrasulfide, 2,2'-bis(phenyl methyl methoxysilylethyl)trisulfide, 3,3'-bis(diphenyl isopropoxysilylpropyl)tetrasulfide, 3,3'-bis(diphenyl cyclohexoxysilylpropyl)disulfide, 3,3'-bis(dimethyl ethylmercaptosilylpropyl)tetrasulfide, 2,2'-bis(methyl dimethoxysilylethyl)trisulfide, 2,2'-bis(methyl ethoxypropoxysilylethyl)tetrasulfide, 3,3'-bis(diethyl methoxysilylpropyl)tetrasulfide, 3,3'-bis(ethyl di-sec.butoxysilylpropyl)disulfide, 3,3,'-bis(propyl diethoxysilylpropyl)disulfide, 3,3'-bis(butyl dimethoxysilylpropyl)trisulfide, 3,3,'-bis(phenyl dimethoxysilylpropyl)tetrasulfide, 3-phenyl ethoxybutoxysilyl 3'-trimethoxysilylpropyl tetrasulfide, 4,4'-bis(trimethoxysilylbutyl)tetrasulfide, 6,6'-bis(triethoxysilylhexyl)tetrasulfide, 12,12'-bis(triisopropoxysilyl dodecyl)disulfide, 18,18'-bis(trimethoxysilyloctadecyl)tetrasulfide, 18,18'-bis(tripropoxysilyloctadecenyl)tetrasulfide, 4,4'-bis(trimethoxysilyl-buten-2-yl)tetrasulfide, 4,4'-bis(trimethoxysilylcyclohexylene)tetrasulfide, 5,5,'-bis(dimethoxymethylsilylpentyl)trisulfide, 3,3'-bis(trimethoxysilyl-2-methylpropyl)tetrasulfide, 3,3'-bis(dimethoxyphenylsilyl-2-methylpropyl)disulfide.
The preferred sulfur-containing organosilicon compounds are the 3,3'-bis(trimethoxy or triethoxy silylpropyl) sulfides. The most preferred compound is 3,3'-bis(triethoxysilylpropyl) tetrasulfide. Therefore, as to Formula I, preferably Z is ##STR4## where R 2 is an alkoxy of 2 to 4 carbon atoms, with 2 carbon atoms being particularly preferred; Alk is a divalent hydrocarbon of 2 to 4 carbon atoms with 3 carbon atoms being particularly preferred; and n is an integer of from 3 to 5 with 4 being particularly preferred.
The amount of the sulfur-containing organosilicon compound of Formula I in a rubber composition will vary, depending on the level of silica that is used. Generally speaking, the amount of the compound of Formula I will range from about 0.01 to about 1.0 parts by weight per part by weight of the silica. Preferably, the amount will range from about 0.02 to about 0.4 parts by weight per part by weight of the silica. More preferably, the amount of the compound of formula I will range from about 0.05 to about 0.25 parts by weight per part by weight of the silica.
In addition to the sulfur-containing organosilicon, the rubber composition should contain a sufficient amount of silica, and carbon black, if used, to contribute a reasonably high modulus and high resistance to tear. The silica filler may be added in amounts ranging from about 10 phr to about 250 phr. Preferably, the silica is present in an amount ranging from about 15 phr to about 80 phr. If carbon black is also present, the amount of carbon black, if used, may vary. Generally speaking, the amount of carbon black will vary from about 5 phr to about 80 phr. Preferably, the amount of carbon black will range from about 10 phr to about 40 phr. It is to be appreciated that the silica coupler may be used in conjunction with a carbon black, namely pre-mixed with a carbon black prior to addition to the rubber composition, and such carbon black is to be included in the aforesaid amount of carbon black for the rubber composition formulation. In any case, the total quantity of silica and carbon black will be at least about 30 phr. The combined weight of the silica and carbon black, as hereinbefore referenced, may be as low as about 30 phr, but is preferably from about 45 to about 130 phr.
The commonly employed siliceous pigments used in rubber compounding applications can be used as the silica in this invention, including pyrogenic and precipitated siliceous pigments (silica), although precipitate silicas are preferred. The siliceous pigments preferably employed in this invention are precipitated silicas such as, for example, those obtained by the acidification of a soluble silicate; e.g., sodium silicate.
Such silicas might be characterized, for example, by having a BET surface area, as measured using nitrogen gas, preferably in the range of about 40 to about 600, and more usually in a range of about 50 to about 300 square meters per gram. The BET method of measuring surface area is described in the Journal of the American Chemical Society, Volume 60, page 304 (1930).
The silica may also be typically characterized by having a dibutylphthalate (DBP) absorption value in a range of about 100 to about 400, and more usually about 150 to about 300. The silica might be expected to have an average ultimate particle size, for example, in the range of 0.01 to 0.05 micron as determined by the electron microscope, although the silica particles may be even smaller, or possibly larger, in size.
Various commercially available silicas may be considered for use in this invention such as, only for example herein, and without limitation, silicas commercially available from PPG Industries under the Hi-Sil trademark with designations 210, 243, etc; silicas available from Rhone-Poulenc, with, for example, designations of Z1165MP and Z165GR and silicas available from Degussa AG with, for example, designations VN2 and VN3.
Tire tread formulations which include silica and an organosilicon compound will typically be mixed utilizing a thermomechanical mixing technique. The mixing of the tire tread rubber formulation can be accomplished by methods known to those having skill in the rubber mixing art. For example, the ingredients are typically mixed in at least two stages, namely at least one non-productive stage followed by a productive mix stage. The final curatives including sulfur-vulcanizing agents are typically mixed in the final stage which is conventionally called the "productive" mix stage in which the mixing typically occurs at a temperature, or ultimate temperature, lower than the mix temperature(s) than the preceding non-productive mix stage(s). The rubber, silica and sulfur-containing organosilicon, and carbon black, if used, are mixed in one or more non-productive mix stages. The terms "non-productive" and "productive" mix stages are well known to those having skill in the rubber mixing art. The sulfur-vulcanizable rubber composition containing the sulfur-containing organosilicon compound, vulcanizable rubber and generally at least part of the silica should be subjected to a thermomechanical mixing step. The thermomechanical mixing step generally comprises a mechanical working in a mixer or extruder for a period of time suitable in order to produce a rubber temperature between 140° C. and 190° C. The appropriate duration of the thermomechanical working varies as a function of the operating conditions and the volume and nature of the components. For example, the thermomechanical working may be for a duration of time which is within the range of about 2 minutes to about 20 minutes. It will normally be preferred for the rubber to reach a temperature which is within the range of about 145° C. to about 180° C. and to be maintained at said temperature for a period of time which is within the range of about 4 minutes to about 12 minutes. It will normally be more preferred for the rubber to reach a temperature which is within the range of about 155° C. to about 170° C. and to be maintained at said temperature for a period of time which is within the range of about 5 minutes to about 10 minutes.
The tire tread compounds of this invention can be used in tire treads in conjunction with ordinary tire manufacturing techniques. Tires are built utilizing standard procedures with the polybutadiene rubber blend simply being substituted for the rubber compounds typically used as the tread rubber. After the tire has been built with the polybutadiene rubber-containing blend, it can be vulcanized using a normal tire cure cycle. Tires made in accordance with this invention can be cured over a wide temperature range. However, it is generally preferred for the tires of this invention to be cured at a temperature ranging from about 132° C. (270° F.) to about 166° C. (330° F.). It is more typical for the tires of this invention to be cured at a temperature ranging from about 143° C. (290° F.) to about 154° C. (310° F.). It is generally preferred for the cure cycle used to vulcanize the tires of this invention to have a duration of about 10 to about 20 minutes with a cure cycle of about 12 to about 18 minutes being most preferred.
By utilizing the rubber blends of this invention in tire tread compounds, traction characteristics can be improved without compromising tread wear or rolling resistance. Since the polybutadiene rubber blends of this invention do not contain styrene, the cost of raw materials can also be reduced. This is because styrene and other vinyl aromatic monomers are expensive relative to the cost of 1,3-butadiene.
This invention is illustrated by the following examples which are merely for the purpose of illustration and are not to be regarded as limiting the scope of the invention or the manner in which it can be practiced. Unless specifically indicated otherwise, parts and percentages are given by weight.
EXAMPLE 1
In this experiment, a tin-coupled polybutadiene rubber was prepared in a 10-gallon (38 liter) batch reactor at a temperature of 70° C. In the procedure used, 22,400 grams of a silica/molecular sieve/aluminum dried premix containing 17.5 weight percent of 1,3-butadiene in hexanes was charged into the 10-gallon reactor. After the amount of impurity in the premix was determined, 28.8 ml of 1.6 M solution of n-butyl lithium (in hexane) was added to the reactor. The target Mn (number averaged molecular weight) was 100,000. The polymerization was allowed to proceed at 70° C. for two hours. An analysis of the residual monomer indicated that all monomers were totally consumed. After a small aliquot of polymer cement was removed from the reactor (for analysis), 9.2 ml of a 0.65 M solution of tin tetrachloride (in hexane) was added to the reactor and the coupling reaction was carried out at the same temperature for 30 minutes. At this time, 1.5 phr (parts per 100 parts by weight of rubber) of antioxidant was added to the reactor to shortstop the polymerization and to stabilize the polymer.
After the hexane solvent was evaporated, the resulting tin-coupled polybutadiene was dried in a vacuum oven at 50° C. The tin-coupled polybutadiene was determined to have a glass transition temperature (Tg) at -95° C. It was also determined to have a microstructure which contained 8 percent 1,2-polybutadiene units and 92 percent 1,4-polybutadiene units. The Mooney viscosity (ML 1+4@ 100° C.) of the tin-coupled polybutadiene made was determined to be 110. The Mooney Viscosity of the base polybutadiene rubber was also determined to be 11.
EXAMPLE 2
In this experiment, asymmetrically tin-coupled polybutadiene was synthesized in a three-reactor (2 gallons each) continuous system at 90° C. A premix containing 15 percent 1,3-butadiene in hexane was charged into the first reactor continuously at a rate of 117 grams/minute. Polymerization was initiated by adding a 0.128 M solution of n-butyl lithium into the first reactor at a rate of 0.82 grams/minute. Most of monomers were exhausted at the end of second reactor and the polymerization medium containing live lithium ends was continuously pushed into the third reactor where the coupling agent, tin tetrachloride (0.025 M solution in hexane), was added at a rate of 1.16 grams/minutes. The residence time for all three reactors was set at 1.5 hours to achieve complete monomer conversion in the second reactor and complete coupling in the third reactor. The polymerization medium was then continuously pushed over to a holding tank containing a shortstop and an antioxidant. The resulting polymer cement was then steam-stripped and the asymmetrical tin-coupled polybutadiene recovered was dried in an oven at 60° C. The polymer was determined to have a glass transition temperature at -95° C. and have a Mooney ML 1+4@ 100° C. viscosity of 94. It was also determined to have a microstructure which contained 8 percent 1,2-polybutadiene units and 92 percent 1,4-polybutadiene units. The precursor of this polymer (i.e., base polymer prior to coupling) was also determined to have an ML 1+4@ 100° C. of 20.
EXAMPLES 3-4 AND COMPARATIVE EXAMPLES 5-8
In this series of experiments, various rubber blends were prepared and evaluated as tire tread rubber compositions. These blends were prepared by a three-step mixing process. In the first step, non-productive blends were made by mixing the rubbers shown in Table I with 7.0 parts of processing aids, 3 parts of zinc oxide, 2 parts of stearic acid and 0.15 parts of 2,2'-dibenzamidodiphenyl disulfide. This first non-productive mixing step was carried out over a period of about 4 minutes which resulted in a temperature of about 160° C. being attained.
In the procedure used, 12 parts of fine particle-size hydrated silica, 2.25 parts of a 50 percent/50 percent blend of silica and carbon black (X50S from DeGussa GmbH) and 3 parts of a naphthenic/paraffinic process oil were added to the blend in a second non-productive mixing step. This second non-productive mixing step was carried out over a period of about 3 minutes to a temperature of about 150° C.
A productive compound was then made by mixing 0.66 parts of diaryl-p-phenylenediamine, 1.12 parts of N-tert-butyl-2-benzothiazole, 0.14 parts of tetramethylthiuram disulfide and 1.5 parts of rubber makers sulfur into the blend. This productive mixing step was carried out over a period of about 2.5 minutes to a drop temperature of about 120° C. Then, the tire tread rubber compounds were cured and evaluated. The results of this evaluation are shown in Table I.
TABLE I______________________________________Example 3 4 5______________________________________Natural Rubber.sup.1 40 49 40Isoprene-Butadiene Rubber.sup.2 453,4-Polyisoprene.sup.3 6High Vinyl Polybutadiene.sup.4 20 20Polybutadiene Rubber.sup.5 40Tin-Coupled Polybutadiene.sup.6 40Carbon Black.sup.7 38 38Silica.sup.8 12 12Rheometer 150° C.Min torque 11 11 9.6Max torque 40.8 41.3 42delta torque 29.8 30.3 32.4T25 6 6.25 6.75T90 9.75 9.75 10.5ATS 18@150100% Modulus, MPa 2.39 2.35 2.31300% Modulus, MPa 11.07 11.09 11.83Brk Str, MPa 16.61 19.27 16.94EL-Brk, % 441 489 418Hardness, RT 61.6 61.6 60.9Hardness, 100° C. 58.8 58.4 58.2Rebound RT % 56.8 56.1 61Rebound, 100° C. 68.9 71.4 71.9DIN 73 96 72Tan Delta -40 0.53 0.43 0.5130 0.32 0.26 0.3020 0.22 0.18 0.2010 0.15 0.14 0.130 0.13 0.13 0.12______________________________________ .sup.1 TSR20 .sup.2 30% Isoprene/70% Butadiene, Tg = -82° C., Mooney ML/4 @ 100° C. = 85 .sup.3 365% 3,4structure, Mooney ML/4 @ 100° C. = 70 .sup.4 80% Vinyl; 82 Mooney, Tg2 .sup.5 Budene 1209 from -28° C. .sup.6 Polymer of Example 1 .sup.7 ASTM N299 .sup.8 HiSil 210 from PPG
It is well known that Sn-coupled polymers provide improvements in processing over their linear counterparts. You see an example of this when comparing the Rheometer minimum torque values of Example 5 versus Example 3. The compound of Example 5 contains tin-coupled polybutadiene and has the lower minimum torque. The rebound values of the compound containing the tin-coupled polybutadiene (Example 5) are higher than for the control Example 3, suggesting better rolling resistance (RR) for the compound containing the tin-coupled polybutadiene.
Example 4 is an example of current passenger tread technology. This tread contains a blend of three polymers: (1) NR for processing and traction, (2) IBR for processing, treadwear and RR and (3) 3,4 polyisoprene for traction. The compound of this invention (Example 5) also uses a blend of three polymers, including NR, high vinyl polybutadiene for traction and Sn-coupled polybutadiene for processing, RR and treadwear.
The lab data (Table I) clearly shows the superiority of the new polymer system over that of the current polymer system. The new polymer system provides improved treadwear (DIN abrasion resistance improved 25 percent), along with reduced rolling resistance (RT rebound values increased 9 percent). The wet traction (measured by the tan delta values from -40° C. through 0° C.) should be equal between the two compounds, as can be seen from the tan delta values reported in Table I. It should be noted that higher tan delta values in the range of -40° C. to 0° C. are predictive of better wet reaction characteristics in tires.
In summary, the new polymer system (Example 5) improves the tradeoff between RR, treadwear and wet traction versus current technology (Example 4) and the control polymer system (Example 3).
Variations in the present invention are possible in light of the description of it provided herein. While certain representative embodiments and details have been shown for the purpose of illustrating the subject invention, it will be apparent to those skilled in this art that various changes and modifications can be made therein without departing from the scope of the subject invention. It is, therefore, to be understood that changes can be made in the particular embodiments described which will be within the full intended scope of the invention as defined by the following appended claims.
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This invention relates to a tire tread compound that is easily processable which can be used to improve the treadwear, rolling resistance and traction characteristics of tires. The tire tread compounds of this invention are a blend of tin-coupled polybutadiene, high vinyl polybutadiene and natural rubber. This blend of low glass transition temperature rubber and high glass transition temperature rubber is surprisingly easy to process which makes the concept of this invention commercially feasible. Thus, the tire tread compounds of this invention can be utilized in making tires having greatly improved traction characteristics and treadwear without sacrificing rolling resistance. These improved properties may be due, in part, to better interaction and compatibility with carbon black and/or silica fillers. The polybutadiene in the blend can be asymmetrical tin-coupled to further improve the cold flow characteristics of the rubber blend. Asymmetrical tin coupling in general also leads to better processability and other beneficial properties. This invention more specifically discloses a tire tread rubber composition which is comprised of (1) from about 20 phr to about 60 phr of tin-coupled polybutadiene rubber, (2) from about 20 phr to about 60 phr of a rubber selected from the group consisting of natural rubber and synthetic polyisoprene and (3) from about 5 phr to about 40 phr of high vinyl polybutadiene rubber.
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This is a continuation of co-pending application Ser. No. 205,677, filed on June 13, 1988, now abandoned.
SUMMARY OF THE INVENTION
The invention disclosed herein comprises a shield, manufactured of plastic in two sections, which protects a storm drain outlet pipe. The shield is set down into the storm drain and secured to the storm drain walls. The placement of the shield stops damage caused by mechanical devices inserted into the drain. The placement of the shield also prevents destructive particles from entering the intake area of the storm drain.
BRIEF DESCRIPTION OF THE DRAWINGS
Further details are explained below with the help of the example(s) illustrated in the attached drawings in which:
FIG. 1 is a front elevational view of the shield according to the present invention; and
FIG. 2 is a top plan view of the shield shown in FIG. 1 positioned in a storm drain.
DESCRIPTION OF THE PREFERRED EMBODIMENT
There is shown in FIG. 1. a drain pipe shield 10 comprising a first section 12 and a second section 14. The two sections 12 and 14 are generally arched, rectangular in configuration and may be formed of polypropylene or a similar substance. In an engaged position, sections 12 and 14 form a convex shape providing a barrier between an intake area 2 within which an outlet pipe 36 is positioned and a discharge area 4 of a shield 10 protects the outlet pipe 36 from elements such as cleaning clam shells which are inserted into the drain 30. The first section 12 contains a first side edge 16, a second side edge 18, and a fifth side edge 32. The second section 14 includes a third side edge 19, a fourth side edge 17, and a sixth side edge 34. The first and fourth side edges 16 and 17 are in apposed, substantially parallel relation.
The two sections 12 and 14 fit together in a hinged relationship the elements of which are positioned on the second and third side edges 18 and 19 as shown in FIG. 1. The side edges 18 and 19 each are provided with a series of interlocking knuckles. The knuckles are coaxially aligned in a vertical relation. Each knuckle has a through hole 13 through which a pull pin 37 can be placed to hold the sections 12 and 14 in a substantially fixed position. Side edge 32 is in integral angular relationship with side edge 18 and side edge 34 is in integral relation with side edge 19. When the pull pin 37 is engaged the side edges 32 and 34 form a substantially U-shaped configuration allowing access to a first opening 45 without the necessity of opening the shield. This U-shaped configuration allows approximately 98% fluid discharge 4 from the discharge area over the shield to the intake area 2.
The first section 12 has an inner surface 20 and an outer surface 22. The second section 14 has an inner surface 21 and an outer surface 23. The inner surface areas of sections 12 and 14 can be ribbed for added strength. The top edge of the shield 10 and side edge 16 define a first corner. A first pintle hinge 24 is secured to the outer surface 22 adjacent the first corner. The first section 12 and second section 14 contain bottom edges 38 and 40 respectively. A second pintle hinge 26 is secured to the outer surface 22 at a second corner defined by the bottom edge 38 and the side edge 16. A third pintle hinge 25 is secured to a third corner defined by the top edge of the shield 10 and side edge 17. A fourth pintle hinge 27 is secured to a fourth corner defined by the bottom edge 40 and the side edge 17. The pintle hinges 24, 25, 26, and 27 are welded into position on the shield in a manner known in the art.
A continuous wall 28 forms the interior surface of the storm drain 30. The pintle hinges 24 and 26 are aligned and secured to the continuous circumferential wall 28 supporting first section 12 in a right angle relationship with a base portion 42 of the drain 30. The second set of pintle hinges 25 and 27 are aligned and support section 14 in a manner similar to section 12. The pintle hinges 24, 25, 26, and 27 can be attached to the surface 28 by inserting screws or similar fasteners through apertures set in the hinges and into anchors set into the cement of the wall 28.
The pintle hinges 24, 25, 26, 27, may be designed to lock in two positions, the upper position allows the bottom edges 38 and 40 to be positioned approximately 2" above the base portion 42 of the storm drain 30. When the pintle hinges are set into their lower position the shield rests just above the base portion 42. Single position hinges can also be used, in this embodiment the bottom edges 38 and 40 would rest on the base portion 42. In the case of the single position hinges, because the upper surface of the base portion 42 is irregular, sand and fine grit could wash through openings under the sides 38, 40 into the intake area 2.
It is also possible to have the shield 10 unitary in configuration. Side edges 18 and 19 would be eliminated, along with the need for the pull pin 37 and through hole 13. All other aspects of design would be essentially the same.
In a locked position the drain pipe shield 10 acts as a buffer protecting the outlet pipe 36 from objects entering the discharge area 4 of the storm drain 30. When a maintenance crew is conducting regular maintenance of the drain a mechanical cleaning device or a suction hose is inserted through the top of the drain 30 down into the storm drain chamber to remove grit and debris from the base portion 42. In many instances the mechanical device or hose will swing within the chamber area, if unportected the drain pipe can be severely damaged by blows from the mechanical device. By placing the shield 10 in front of the outlet drain 36, the damage can be averted.
An additional function of the drain pipe shield is as a grit sieve. The action of the water against the shield would allow only a minor amount of smaller particles to pass under or over the shield while keeping large destructive particles in the discharge area 4. These destructive particles of sand and grit can then be removed by the mechanical claw or vacuum.
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A plastic shield which is generally rectangular and convex in shape is inserted into a storm drain to provide protection to a storm drain outlet from cleaning tools. The shield is constructed in two sections and is moveably connected to the storm drain to allow workman easy access to the storm drain outlet.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention pertains generally to the field of automated design techniques for electronic circuits, and more particularly to compaction and pitchmatching methods for hierarchically defined layouts of integrated circuits, and systems for implementing these methods.
2. Description of the Background Art
The complete design of an integrated circuit can be a very laborious and time-consuming process, and for many chips of practical interest the physical design of the electronic circuit is far too complex to be carried out without the aid of computers and sophisticated design tools. Since the advent of VLSI circuit technology this field of design automation has grown rapidly, and is becoming a mature technology in itself. There are now a variety of techniques available to aid the designer, and a substantial number of computer programs have been written to implement these techniques.
The physical design of an integrated circuit can be carried out in terms of the symbolic layout of the circuit, rather than the actual geometry of the masks and lavers that comprise the chip. The designer can thus work with transistors, wires, and other primitive components, and groups of these components termed "cells", represented by various symbols. The symbolic layout provides a higher level of abstraction than the mask layout, and is therefore easier for the designer to manipulate. The layout of these symbols can then be translated into a mask layout suitable for the actual fabrication of the chip. This translation requires additional technical information regarding the fabrication technology, which is stored in a "technology database" and used when the translation is carried out.
A symbolic layout that contains only primitive symbols--i.e. transistors, wires, capacitors and other physical components--is termed a "leaf cell". Many layouts contain a large number of groups of components that are substantially identical. Such a group may be used to define a cell, and the description of the layout may then be simplified by treating each such group as an instance of this cell. The cell has its own symbol; for example it may be represented as a rectangle with various ports for connecting wires or for abutment with ports of adjacent cells that are represented similarly. The components of the overall layout then may consist of cells, and the layout represents their relative placement and interconnection. By describing the layout in terms of cells rather than primitive symbols, again the designer's task is made much simpler.
Similarly, a given layout of cells may contain a large number of groups of cells, or cells and other components, in which the groups are identical. Such a group of cells may be used to define a "supercell", and the layout may again be simplified by treating each such group of cells as an instance of the supercell. Again, this supercell has its own symbol and ports, and the overall layout is a representation of the arrangement and interconnection of these supercells.
Obviously this process may be repeated, so that a symbolic layout can-be treated as a hierarchical structure with multiple levels. Each level is a symbolic layout of various cells and primitive components. Each such cell is in turn a symbolic layout of subcells and primitive components, and this layout defines the next lower level of the hierarchy. Since there may be more than one type of cell at any given level, the next lower level may contain several different branches. The cells at the lowest level are leaf cells since they contain no subcells, but only primitive components. Therefore the hierarchy can be visualized as an inverted "tree" with branches extending downward, and the lowest level depends on the branch in which it is located. In short, the leaf cells are located at the ends of the branches, and the trunk of the tree represents the symbolic layout of the whole chip, which is often termed the "root cell". This hierarchical description is a natural and concise representation for large designs.
The task of integrated circuit design generally includes optimization of one or more parameters of the circuit. The designer usually attempts to minimize the geometrical size of the overall structure. This minimization is subject to several constraints that ensure that the technical design rules are followed and the integrity of the circuit is maintained. For example certain components of the circuit must be separated by a minimum distance, and the connections between different components must be maintained. The automated process of size minimization is known as compaction. The compactor is a computer program that operates on a symbolic layout that constitutes the input data and produces a new symbolic layout. This new layout corresponds to the design of the minimum size circuit that preserves the integrity of the original circuit and complies with the design rule requirements.
Compaction of leaf cells is a process that has been studied extensively. Compaction techniques for leaf cells have been summarized in the article by David G. Boyer entitled "Symbolic Layout Compaction Review", given at the ACM IEEE 25th Design Automation Conference, 1988, paper 26.1. Some researchers have attempted to use leaf cell compactors on hierarchical symbolic layouts. For example, obviously one can "flatten" a given hierarchical layout into a leaf cell and then use a leaf cell compactor. This method would give a layout of absolute minimum size. However, such a brute force method has the drawback that the size of the database for the compacted output layout becomes enormous and the compaction process becomes prohibitively expensive even for layouts of moderate size. Furthermore the characterization and modification of the output layout is more difficult because the input hierarchy is lost in the compaction process.
Another approach to hierarchical compaction is the "bottom-up" technique, in which leaf cell compaction is applied level by level starting from the leaf cells and working upward. During compaction of each level of the hierarchy the cells and subcells are assumed to be rigid objects. Once a given level is compacted, the connectivity or port abutment between cells at the next higher level is generally destroyed and must be re-established before the next level can be compacted. This degradation of cell connectivity is a serious drawback in designs with cells that are largely connected by abutment.
A further approach is to de-couple the cell abutment and compaction problems. One simply fixes the port positions of leaf cells without taking into account the design constraints within these cells. One then applies a leaf cell compactor to these leaf cells with fixed port positions. A similar process is carried out at higher levels. This technique can lead to infeasible designs since the fixing of port positions may produce an over constrained compaction problem. Such a methodology is often a time-consuming trial and error process, and the resulting solution is usually sub-optimal.
A recent attack on the hierarchical compaction problem has been described in the paper by David Marpie entitled "A Hierarchy Preserving Hierarchical Compactor", published in ACM IEEE 27th Design Automation Conference, 1990, pp. 134-140. This technique simultaneously carries out leaf cell compaction and maintains the port connectivity between abutting cells, (termed "pitchmatching"), while preserving the hierarchical structure. In this method, the global compaction problem is formulated as a linear programming problem, which is solved by the "Revised Simplex Method". The number of variables and constraints that must be handled grows with the size of the hierarchy, and the computation time increases rapidly with the hierarchy size. Hence, the complexity of the overall method is significant and the size of the layout that can be dealt with is limited.
In short, the definition of hierarchical compaction in the truest sense is the minimizing of the area of the hierarchically defined symbolic layout while preserving the hierarchical structure, design rule compliance, and electrical connectivity between components and cells. For cells connected by abutment in the input layout, the connection must be maintained in the compacted layout; i.e. the compactor must include pitchmatching. The entire process must be handled globally; all constraints throughout the layout must be treated simultaneously. Prior to the present invention, no satisfactory techniques have been available for carrying out this compaction for large-sized layouts.
SUMMARY OF THE PRESENT INVENTION
The present invention is a hierarchical compactor which maintains hierarchical structure, design rule correctness, and pitchmatching. This hierarchical compactor can handle very large designs by reducing the linear programming problem to its minimal size. This reduction is accomplished by taking advantage of the redundancies in the original problem to transform the original layout hierarchy to a reduced representation, termed the "minimum design", which captures all the necessary features of the input layout. The reduction is effected by breaking the original problem, specifically the relationships describing the constraints, into three classes, namely (A) intracell constraints, (B) intercell constraints, and (C) loop constraints. In each of these classes of constraints the minimum set of relationships which carries all the information in that class is identified. This minimum set of constraint relationships is the set that corresponds to the minimum design. Compaction is carried out with this minimum set, and then the results are transformed back to obtain the compacted version of the original layout.
This method is a distinct improvement in that the original linear programming problem is vastly reduced by the transformation to the minimum design problem. The compaction of this minimum design can be carried out with much less computational time, and depending on the amount of regularity in the original layout the amount of data involved can be far smaller than the compaction of the original layout. This method is guaranteed to find the optimal solution of the compaction problem subject to the exact preservation of the hierarchical structure, and it is computationally feasible for large layouts.
The method is carried out by means of a computer program. The symbolic layout is represented in numerical form, and the representation contains all the information necessary to specify the hierarchical structure, cell definitions and locations, positions of components and electrical interconnections. The output of the program is the numerical representation for the compacted layout.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing compaction system (70) of the present invention;
FIG. 2(a)-(b) is a flow diagram illustrating the method of the present invention;
FIG. 3(a) is a typical circuit schematic diagram having a layout representation which would be compacted using the present invention;
FIG. 3(b) is a functional schematic representation of the cell layout of FIG. 3(a);
FIG. 3(c) is a functional representation of FIG. 3(b) following normalization;
FIG. 4(a) and 4(b) are block representations of cells X, Y, and Z, before and after graphing;
FIG. 5 is a diagram of eight instances of two types of cells, A and B, in a configuration with five different types of interfaces; and
FIG. 6 is a diagram of a hierarchical layout that is built up from two leaf cells, labelled A and B in the Figure, showing 5 levels of hierarchy above the leaf cell structure.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, a block diagram of compaction system 70 of the present invention is shown. The preferred embodiment is implemented on a general purpose computer such as a Sun Microsystems, Inc. workstation. Utilizing dedicated software, the general purpose computer specifically configures memory and system peripherals for the purpose of executing steps of this preferred method. Compaction system 70 comprises processor 71, display 73, keyboard 75, printer 77, program memory 88, and local area network 78. Processor 71 executes instruction steps stored in program memory 88, while keyboard 75 and display 73 provide a user interface to processor 71. Printer 77 generates a permanent record of the compaction of the present invention, and local area network 78 enables processor 71 to communicate and exchange information with external computers and compaction systems. Not shown in FIG. 1, but useful as an alternative embodiment, is a digitizing table for identifying and generating coordinates and integrated circuit (IC) layouts. Processor 71 is connected to various memories and storage devices through data bus 81. Connected to data bus 81 are layout coordinate register 83, normalized cell list register 85, graph register 87, primitive loop register 89, reduced graph register 91, compaction direction flag register 93, intracell constraint register 95, intercell constraint register 97, and compacted coordinate register 99.
Layout coordinate register 83 stores data relating to layout coordinates of the target IC or integrated circuit board to be compacted. In the discussion that follows the compaction system and method will be directed to the reduction of geometrical areas of an integrated circuit (IC) layout. It should be noted, however, that this method and system find useful application in the compaction of circuit board layouts as well. When creating mask works for integrated circuits, designers typically begin with a circuit schematic consisting of an interconnected network of logic or circuit elements. The designer generally has available a library of mask work patterns or cells which correspond to the various circuit element used in the design. Creating a mask work then consists of transforming the circuit schematic by substituting various library patterns for the schematic circuit elements in such a way as to provide efficient use of available mask area. The compaction process of the present invention is directed to the reduction of the geometries of this mask area. Elements in each of these cells have coordinate attributes as well as a variety of design rules which govern the location and relative placement of components and features within each of these cells. These rules are also referred to as constraints. A typical constraint might reflect the minimum allowable distance from which a ground line may be placed next to a power bus, in order to avoid a short circuit over the range of processing tolerances.
Normalized cell list register 85 stores coordinates which result from the normalization of the layout as described in the steps below. Following the substitution of library cells for schematic elements, the new layout representation, which comprises this collection of abutting cells, is transformed into a graph representation referred to as an interface graph. This interface graph provides a useful model within which the cell geometries may be more easily reduced. The coordinates and related data which describe this graph representation are stored in graph register 87. Primitive loop register 89 stores data relating to the relative distances between the various cells described. A useful feature of "graphing" the cell relationships (creating graph representations of the cell) within the IC layout, is that certain redundancies can be identified and easily eliminated. Following this elimination of redundancies, the remaining circuit layout is stored in reduced graph register 91.
Subsequent to graph reduction, a compaction process is employed which can be operated in either the x-direction or the y-direction of the two-dimensional IC layout. This direction is chosen more or less randomly and is stored in compaction direction flag register 93. Intracell constraint register 95 stores a list of design rules which must be internally maintained when using the cell in a larger structure. Examples of these rules include minimum distances between metal lines and minimum widths of the various power and ground traces. Intercell constraint register 97 contains a set of constraints or rules which define the relationships which must be maintained between two interacting cells. Compacted coordinate register 99 stores the coordinates of the reduced IC layout following compaction, and is used in the generation of the finished mask work.
A flow diagram outlining the compaction process of the present invention is shown in FIG. 2. As described above, the purpose of this compaction process is to reduce the physical geometric surface area required for the implementation of a given electronic circuit by a mask work. A portion of a typical circuit schematic, the layout representation of which would be compacted using this method and system, is shown in FIG. 3(a). In the sample circuit, two elements are shown: an inverter 27, and a two-input AND gate 25 having its output connected to the inverter 27. The output of inverter 27 feeds back along path 23 and comprises one of the two inputs to AND gate 25. An integrated circuit mask work layout of this sample schematic 21 would be created using library cells which execute the functions of the individual circuit elements 25, 27. An example of this layout implementation is shown schematically in FIG. 3(b) where AND gate 25 is substituted by an AND gate functional layout 29 (represented by the box surrounding the circuit element). Inverter 27 likewise is represented by an equivalent layout 31.
The first step 40 of the process shown in FIG. 2 involves annotating the layout so that the various cells and components can be easily manipulated by a computer. This annotation consists of a coordinate representation which describes the relative location of each cell and component with respect to others in the layout. This annotation is either directly available within cells of a cell library, or may be created for non-library cells by digitizing artwork of the non-library cell layout. The various coordinate data is stored by processor 71 in layout coordinate register 83.
The circuit shown in FIG. 3(b) is often referred to as a higher level hierarchical cell since each of the elements represented by circuit components within the layout may actually have one or more subcells comprising them. In addition, although AND gate 29 and inverter 31 are each cell components, the various routing elements, such as feedback 23, are not in this representation identified by a separate cell. The purpose of next step 42 is to normalize the overall hierarchical layout structure into a representation in which all cells within the layout abut or connect each other and in which all cells can be treated as being at electrically the same level. In implementing the normalization of step 42, processor 71 redefines each cell of the layout stored in layout coordinate register 83 to be either a pure hierarchy cell containing only instances of other cells, or a pure leaf cell, i.e., containing only primitive components. In addition, all cells are defined such that all interconnections between cells are defined by abutment, that is so that each of the cells have boundaries which are connected directly to other cells. For example, FIG. 3(c) shows the corresponding layout of FIG. 3(b) following normalization in which the routing is also assigned a cell structure 33. In the simple normalized structure of FIG. 3(c), AND gate 25 is connected directly to and abuts routing cell 33, which also directly connects and abuts inverter 31. Each of these cells are treated as being on the same hierarchical level in the normalized layout. The geometrical coordinates of this new normalized layout are stored by processor 71 in normalized cell list register 85.
The next step 44 is to generate interface graphs for the normalized layout. This technique is described in an article by C. Bamji, C. Hauck, and J. Allen, entitled "A Design-By-Example Regular Structure Generator" published in ACM IEEE 22nd Design Automation Conference, 1985. An interface graph is a representation of a layout that captures the relative placement of cells in which the vertices represent instances of a cell, and the edges (lines between vertices) represent interfaces which are the legal relative placements between two corresponding cells. The transformation from layout to graph is reversible. This graphing technique is used because it is more amenable to geometrical compaction. The data generated during this graphing transformation are stored by processor 71 in graph register 87. A sample of the graphing technique is shown in FIGS. 4(a) and 4(b). In FIG. 4(a), a block representation of normalized cells X, Y and Z is shown having interfaces I XZ , I XY , and I YZ . FIG. 4(b) shows cells X, Y and Z following graphing. Cell instances X, Y and Z are shown as vertices contained within bubbles, and each cell instance X, Y and Z, is connected by edges labeled I XY , I YZ , and I XZ .
The next step in the process is to find primitive loops as indicated in step 46. Each loop defines the relationships between the relative positions of the various nodes of the interface graph. The number of loops in a layout grows very rapidly with the size of the layout. Theoretically a loop equation is required for every loop. However not all of the loops are independent. For example, in FIG. 5 the loop L 4 can be derived by adding loops L 1 , L 2 . In this Figure it is evident that loops L 1 , L 2 , and L 3 are independent in the sense that no one loop can be obtained by adding the others. Also, all other loops can be derived as compositions of the "primitive loops" L 1 , L 2 , and L 3 . However, loop L 3 also represents the same pattern of cells A and B, as loop L 1 , and thus gives rise to the same equation. In reducing the problem to be solved by linear programming, it is desirable to find the minimum set of loop constraint equations. The set of all possible loops can be derived from a small set of "primitive loops"; for example, loops L 1 , L 2 , L 3 are the primitive loops of FIG. 5. The primitive loops are determined by the faces of the interface graph, which can be obtained generally by the algorithm described in tile paper by J. Hopcroft and R. Tarjan entitled "Efficient Planarity Testing", published in the Journal of the ACM, 21-4:549-568, 1974. Once the primitive loops are found, the corresponding loop constraint equations are constructed. In the next step 48, these equations are then subjected to the well-known Schmidt Orthonormalization Method to obtain a complete linearly independent set of loop constraint equations (L 1 & L 2 ). This set is the minimum set of equations required to describe all of the loop constraints in the layout. The primitive loop equations are stored in primitive loop register 89, and the set of reduced equations are stored in reduced graph register 91. This construction of the minimum set of loop equations is referred to as "extracting the minimum design."
Step 50 of FIG. 2 involves the choosing of a compaction direction in either the x or y direction in a two-dimensional cartesian layout. In the minimization step 56 discussed below, different compaction results are achieved based on the initial direction of compaction. In step 50 one of the two initial starting directions is chosen. The direction selection is stored by processor 71 in compaction direction flag register 93.
Step 52 involves the generation of intracell constraints and storage of these constraints in intracell constraint register 95. Cells interact with other cells through a small number of objects called ports. The total number of these ports is considerably less than the total number of objects in the cell. The intracell constraints are the constraints between the ports induced by the geometrical spacing constraints between all elements in the cell. Examples of these geometrical spacing constraints include minimum distances between metal lines and the minimum widths of power lines and ground connections. Given port positions satisfying the intracell constraints, it is always possible to find the solutions for internal elements of the cell that satisfy all of the internal constraints. Following the generation of intracell constraints, intercell constraints are generated in step 54 and stored in intercell constraint register 97. For every distinct interface, a set of intercell constraints is generated to preserve abutment and design rule enforcement across cell boundaries. Many interfaces correspond to equivalent pairs of cell instances in the same configuration. All of these equivalent pairs are forced to have the same interface constraints, and therefore the number of intercell constraints is proportional to the number of distinct interfaces, which is small.
In minimization step 56, the total area of the interface graph is minimized by simultaneously solving the intracell, intercell constraints as well as the minimum loop constraints. Finding the minimum area solution of these constraints is most easily carried out using known techniques of linear algebra, such as the Revised Simplex Method. Once the linear optimization problem is solved, the next step 58 involves generation of internal cell elements conforming to the values of the port positions derived by linear programming as mentioned above. Because the port positions satisfy the intracell contraints, this operation is always possible and is carried out using known graph techniques.
Following the generation of cell internal elements in step 58, decision block 60 is reached in which a determination of whether to repeat the compaction is made. This choice is largely heuristically determined, based on a number of factors such as total overall geometry of the cell and the amount unused space contained within the cell layout following compaction. If compaction is to be repeated, the orthogonal compaction direction is chosen in step 50. Various alternatives for compaction are available. One way is to compact in the X direction, then in the Y direction, and finally again in the X direction ("X--Y--X compaction"). Obviously one could also carry out Y--X--Y compaction. Theoretically this process could be carried further, e.g. X--Y--X--Y--X compaction, and so on. For practical purposes, after the first three compaction passes are carried out, there are no further significant changes in the resulting layout from additional compaction iterations. An overall strategy of compaction is to first perform X--Y compaction to obtain one layout, and then perform Y--X compaction (on the original layout) to obtain a second layout. The two compacted layouts are compared and the one with the smallest physical size is used in generating the mask works.
Once compaction is completed, the next step 62 is to recompute all of the cells and cell interfaces from the compacted interface graphs. This is the reverse of the previous step 44.
Next, the compacted layout is denormalized in step 64. This denormalization is the reverse of the previous normalization of step 42. Step 68 involves the preparation of circuit masks works from the now compacted layout. This mask may be produced by lithography or by a variety of known electrophotographic techniques.
EXAMPLE
FIG. 6 is a diagram of a hierarchical layout structure built up from two leaf cells, labeled A and B, which contain ports to be abutted. Table 1 shows the number of variables and the number of constraints required at each level of the hierarchy for the present method. Even though the depth of the hierarchy increases and the number of instances explodes, the number of variables and constraints required reach a constant value.
TABLE 1______________________________________ Present Method Number Number Number of of ofCell Instances Variables Constraints______________________________________Level 1 6 11 13Level 2 24 13 17Level 3 96 13 17Level 4 384 13 17Chip 1536 13 17______________________________________
The foregoing description of the preferred embodiment of the invention is presented only for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teaching. For example, this method and apparatus can be applied to other areas of design automation such as printed circuit board design and circuit verification. This embodiment is chosen and described in order to best explain the principles of the invention and its practical applications to thereby enable others skilled in the art to best utilize the invention in various embodiments and with various modifications as are suitable to the particular use contemplated. It is intended that the spirit and scope of the invention are to be defined by reference to the claims appended hereto.
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A hierarchical pitchmatching compactor is provided that maintains hierarchical structure, design rule correctness, and circuit integrity of a symbolic layout while globally compacting the layout without excessive computational or data handling requirements, even for layouts of substantial size. The compactor achieves this result by taking advantage of the regularity of the layout, to reduce the number of constraints in the linear programming problem to a minimum level. This minimal problem, called the minimum design, can be drastically smaller than the original minimization problem for layouts of practical interest. This technique is implemented by means of a computer program that operates on the original symbolic layout of an integrated circuit to produce an automatically compacted layout as the data output.
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BACKGROUND OF THE INVENTION
The field of this invention is that of edgeboard connectors for mounting printed circuit boards, and the invention relates more particularily to edgeboard connectors having large numbers of contacts adapted to make electrical connection to one or more printed circuit boards each having a relatively lesser number of contact pads.
When edgeboard connectors are mounted on large printed circuit boards to permit a number of smaller printed circuit board units to be detachably mounted on the larger board by being inserted into the connectors, the connectors sometimes have contacts which exactly correspond in number to the contact pads provided at the edges of the smaller circuit board units. In that arrangement, when terminal portions of the connector contacts are soldered to circuit pads on the larger circuit boards and the smaller circuit boards are inserted into the connectors, the contact pads on the smaller units are easily mated with the correct contact means in the connectors. If neccessary, the smaller boards and the connectors sometimes have eccentrically disposed polarizing means such as grooves in the edges of the smaller boards which mate with thin ribs in the connectors only when the smaller boards are inserted into the connectors with the proper orientation of the top and bottom sides of the smaller board units.
However, in many printed circuit board systems, the connectors mounted on the larger circuit board have a much greater number of contacts than are necessary for making electrical connection to the number of contact pads at the edges of the small circuit board units to be mounted in the connector. Sometimes several of the smaller board units such as memory modules or the like are mounted in the same edgeboard connector. In such cases, when certain connector contacts are soldered to particular circuit pads on the larger board and when the smaller board units are inserted into the connectors, the connector contacts may be inadvertantly engaged with other than the intended contact pads on the smaller board units. In that regard, the contact pads are typically arranged at the edges of the smaller board units to have a standardized center-to-center spacing between the pads on the board units and they usually have a standardized end spacing between the lateral edges of the boards and contact pads adjacent to those lateral edges.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a novel and improved edgeboard connector; and to provide an edgeboard connector having a relatively large number of contacts adapted to mount one or more printed circuit board units having a relatively smaller numbers of contact pads with assurance that contact pads on the printed circuit board units are properly mated with predetermined contacts in the connector.
Briefly described, the novel and improved edgeboard connector of this invention is adapted to mount printed circuit board units having any number of contact pads within a selected range where those pads are disposed along a first edge of the board unit. The connector comprises an elongated insulating housing having an elongated cavity and has a plurality of electrical contacts greater in number than said selected range disposed within the housing cavity for electrically engaging the contact pads on a board unit when a first edge of the board unit is inserted into the housing cavity. The connector also includes at least one member which is selectively and detachably attached to the housing within the housing cavity for engaging a lateral edge of the printed circuit board unit to position the unit in the cavity and align the contact pads on the board unit with predetermined contacts in the housing cavity. If desired, several of such detachable members are used to cooperate with ends of the housing cavity in locating several of such smaller circuit board units in the same connector with the pads on each of the smaller board units aligned with and mated with a predetermined group of the connector contacts.
DESCRIPTION OF THE DRAWINGS
Other objects, advantages and details of the novel and improved edgeboard connector of this invention appear in the following detailed description of preferred embodiments of the invention, the detailed description referring to the drawings in which:
FIG. 1 is a perspective view of the connector of this invention illustrating the connector in a printed circuit board system;
FIG. 2 is a section view to enlarged scle along 2--2 of FIG. 1;
FIG. 3 is a section view to enlarged scale along line 3--3 of FIG. 1; and
FIG. 4 is a plan view to enlarged scale of a printed circuit board unit to be mounted in a connector of this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings, 10 in FIG. 1 indicates the novel and improved edgeboard connector of this invention which is shown in a printed circuit board or panel system 11 comprising a relatively large printed circuit board 12 and a plurality of relatively smaller circuit board units 14. In that system, circuit pads 16 are provided on a bottom side of the relatively large printed circuit board 12 (see FIGS. 2 and 3) and a plurality of openings 18 in the larger board extend from the circuit pads to the top side of the larger board. A plurality of the connectors 10 are mounted on the larger board with connector contacts connected to selected circuit pads 16 through the openings 18 and with one or more of the relatively smaller printed circuit board units 14 mounted in each of the connectors 10 as is further described below. For clarity of illustration, only one connector 10 and one of the smaller board units 14 are illustrated in solid lines in FIG. 1 while locations of other connectors and smaller board units are diagrammatically illustrated by broken lines 10a and 14a.
The smaller printed circuit board units 14 used with the connectors 10 are of any conventional type within the scope of this invention and typically have a plurality of contact pads 22 arranged in spaced, side-by-side relation to each other along a first edge 24 of the board unit. In some cases, the contact pads 22 are provided adjacent the first board edge on both top and bottom sides of the smaller circuit board unit. The contact pads 22 are electrically connected by circuit paths 26 to electronic components and the like mounted on the smaller boards as is diagrammatically illustrated at 28 in FIG. 4. Typically the contact pads are arranged with a selected, equal, standardized, center-to-center spacing c of 0.100 inches (or 0.125 or 0.156 inches) along the first board dedge and with a selected, equal, standardized, end spacing e of 0.050 (or 0.063 or 0.78) inches between opposite lateral edges 30 of the smaller board units and the centers of those contact pads 22 which are adjacent those lateral board edges. Where a relatively limited number of contact pads are provided on the smaller board units, the pads are typically disposed on a tongue portion 32 of the smaller printed circuit board units 14 to be mounted in the connector 10. Typically include both custom board units and standardized memory modules and the like as will be understood.
In accordance with this invention, the edgeboard connector 10 comprises an elongated electrically insulating housing 34 having an elongated cavity 36 extending along the length of the housing. Preferably the housing is molded of a rigid glass-filled, nylon or polyester material or the like. A plurality of electrical contacts 38 are mounted in the cavity with a selected center-to-center spacing corresponding to the spacing c between contact pads 22 on the smaller circuit board units 14. Preferably also, the portions of the housing 34,1, 34.2, located at opposite ends of the cavity 36 are spaced at a distance corresponding to the end spacing e shown in FIG. 4 from the center line of the contacts 38 adjacent to the cavity ends. In a preferred embodiment, a plurality of lands 40 and grooves 42 are arranged in spaced relation extending along opposite sides of the cavity 36 so that pairs of the grooves 42 are juxtaposed relative to each other on opposite sides of the cavity. The contacts 38 each preferably comprise single beam contact members which are accommodated in respective grooves 42 to be electrically isolated from each other by the lands 40.
The contact members have respective posts or terminal portions 38.1 press-fitted into openings 44 formed in the bottom of the insulating connector housing cavity to extend from the housing through openings 18 in the larger circuit boards to be soldered to the circuit paths 16 on the larger board as indicated at 46 in FIG. 2. Each contact also has an opposite, resilient contact end 38.2 which is positioned in the housing cavity 36 to make resilient electrical engagement with a contact pad 22 on one of the smaller circuit board units when the smaller unit is inserted into the housing cavity as is also indicated by dotted lines 14a in FIG. 2. As diagrammatically illustrated in FIG. 1, the housing cavity 36 is shown to be relatively much longer than the first edge 24 of one of the small board units 14 so that several of such board units are adapted to be accommodated in a single connector housing. In accordance with this invention, a member 48 is attached to the connector housing 34 within the housing cavity 36 for slideably engaging a lateral edge 30 of a circuit board unit 14 inserted into the cavity, thereby to locate the unit in the cavity to assure that the contact pads 22 on the unit are electrically engaged with predetermined ones of the electrical contacts 38 spaced along the cavity. If desired, the member 48 is molded into the cavity for dividing the connector cavity into predetermined plural sections but preferably the member is detachably attached to the housing within the cavity 36 as shown in FIGS. 1 and 3. In a prefered embodiment, the member has a main part of generally symmetrical, cruciform cross-section as illustrated in FIG. 1 having a selected width w corresponding to the center-to-center spacing c of the contact pads 22 and of the contacts 38 as previously described. In that arrangement, the cruciform section h as two oppositely extending ribs 48.1 fitted into grooves 42 at respective opposite sides of the cavity 36 and has two other oppositely extending ribs 48.2 with a transverse disposition defining the width of the member extending along the length of the cavity 36. The member also has a tang part detachably engaged with detent means in the housing for permitting the member 48 to be detachably attached to the housing at any location along the length of the housing cavity. Preferably for example, the member has a flexible post or tang 48.3 with a barb 48.4 which is deflected in being inserted into a detent opening 50 in the bottom of the connector housing for detachably holding the member in the cavity 36 as shown in FIG. 3. As will be understood, a plurality of openings 50 are spaced along the cavities 36 in alignment with respective grooves 42 and contacts 38 so that the member 48 is adapted to be positioned at any desired location along the length of the cavity. A pair of connector contacts 38 are removed from the connector cavity at the location where the member 48 is located.
In that arrangement, a circuit board unit 14 is easily positioned at the desired location in the connector cavity 36 so that one of the lateral edges 30 of the circuit board units is slidably engaged with member 48 while the opposite lateral edge of the unit preferably engages the housing portion 34.2 at an end of the housing cavity. In that way, the circuit board unit is positioned so that the contact pads 22 on the unit are respectively engaged with the intended contacts 38 in the cavity. Accordingly, when the connector contacts 38 are soldered to circuit paths 16 on the larger circuit boards in the system, the mounting of the smaller circuit board units in the connectors is easily accomplished with assurance that the contact pads 22 on each circuit board unit are electrically connected to intended circuit paths 16 by means of the connector contacts 38. The members 48 are inserted before first insertion of the circuit board units 14 into the connector cavities. Several circuit board units are easily positioned in the same connector cavity separated by a single member 48 as diagrammatically shown in FIG. 1 or several members 48 can be arranged at the various locations in the cavity to hold circuit board units 14 in wider spaced relation to each other in a connector cavity if required.
It should be understood that although particular embodiment of the invention are described by way of illustrating the invention, the invention includes all modifications and equivalents of the described embodiments following within the scope of the intended claims.
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An edgeboard connector having a large number of contacts accommodated in a housing cavity is adapted to mount one or more printed circuit boards having lesser numbers of contacts pads and to assure that the contact pads on the boards are electrically engaged with predetermined ones of the connector contacts by attaching one or more detachable members to the housing within the cavity to engage lateral edges of the printed circuit boards as they are inserted into the connector cavity to position the boards in the cavity.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuation of application Ser. No. 12/262,027 filed Oct. 30, 2008.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to improvements in the construction and manufacture of polymeric bags. In particular, the present invention relates to improvements in the construction and manufacture of drawstring-type polymeric bags, especially polymeric trash bags.
[0004] 2. Description of the Related Art
[0005] Polymeric bags are ubiquitous in modern society. As a natural result of the widespread adoption and use of polymeric bags, the bags are available in a variety of different combinations of materials, capacities, thicknesses, dimensions and colors. Polymeric bags may be used in numerous ways including for long-term storage, food storage and trash collection. In response to consumer demand, manufacturers of polymeric bags have developed several innovations over the years to improve the utility and performance of polymeric bags. The present invention is of particular interest to the use of polymeric bags for trash collection and the methods for securely closing and carrying such trash bags, as well as applying such bags to trash receptacles.
[0006] While the polymeric trash bags available to consumers are available in a variety of different configurations, certain configurations are designed to cater to certain uses and particular segments of the population. When considering the utility of polymeric trash bags, one issue of primary concern to both consumers and manufacturers is how the consumer can securely close and carry the trash bag after filling the bag with debris. Securing the trash bag is of critical importance to containing the trash and other debris inside the trash bag when it is collected and transported. Over the years, the industry has developed several different methods for securely closing and carrying trash bags, each method having certain advantages and disadvantages.
[0007] A few common methods for securely closing and carrying trash bags are used in the vast majority of commercially-available trash bags. The most basic of these methods is to provide a twist-tie or similar strap to secure the top of the bag when it is bunched together. Another common method is to provide two or more flaps extending from the top of the trash bag which may be used for securely tying the top of the bag closed. A third common method for securely closing and facilitating carrying of a trash bag is to provide drawstrings near the top edges of the bag, generally located in the hems along the upper edges of the bag, which may be used to pull the upper opening of the trash bag closed.
[0008] One of the oldest methods for securing a trash bag is to provide a twist-tie to accompany the refuse bag. Twist-tie bags are usually straight-cut bags having an ordinary circular opening at the top of the bag. After the twist-tie bag is filled with trash and debris, the upper opening of the bag is bunched together and the twist-tie is used to hold the bunched up plastic at the top of the bag together to secure the bag for disposal. The twist-ties are typically constructed from a paper-covered semi-rigid wire, a self-securing plastic strap, or other materials. For the consumers, this method of closure can be inefficient, as the twist-ties need to be kept near the trash receptacle in a convenient location for securing the bag. Therefore, alternative solutions were developed which integrate the means for closing and securing the bag opening into the bag design itself.
[0009] The flapped bag, also known as a wave-cut bag, refers to a particular configuration of polymeric bags where the top edges of the bag are cut in a wave-like pattern to provide two or more flaps extending upward from the top of the bag. These flaps allow the user to tie the opposing flaps together thereby securing the contents of the bag inside. When the opposing flaps are secured, the tied flaps also provide a convenient handle for carrying the filled bag. Flapped bags are generally more desirable and easier to use than twist-tie bags, but many consumers still do not find them as desirable as drawstring trash bags for general household use.
[0010] Drawstring trash bags are a popular alternative to the previously described twist-tie and flapped trash bags. As the name suggests, drawstring bags utilize drawstrings, also known as drawtapes, which are incorporated into the bag design. A pair of drawstrings is enclosed within hems running along the top edges, or upper opening, of the trash bag. The drawstrings are attached to the bag by a pair of short seals located near the upper corners of the bag. The short seals are created through a combination of heat and pressure to weld the two drawstrings and the panels of the drawstring bag together. Generally it is desirable to minimize the size of the short seals so as to not use extra plastic, which does not add any capacity to the bag.
[0011] After the bag is filled with trash, the drawstrings can be pulled through a pair of cutouts in the hems. These drawstrings can be tied together, securing the trash and providing a handle for carrying the filled bag. Despite the increased complexity of drawstring trash bags, the growing demand for drawstring trash bags provides the impetus for improvements for such bags, including the improvements disclosed herein.
[0012] Despite the popularity of drawstring bags, such bags are not without some criticism. In particular, many consumers find that the drawstring bags are difficult to secure over the upper lip of a trash receptacle. Therefore, it would be desirable to offer a drawstring trash bag that makes it easier to place the top of the drawstring bag over a trash receptacle. While the fit of a conventional drawstring trash bag over the upper lip of the receptacle may be sufficient in some cases to keep the drawstring bag secured onto the trash receptacle, the drawstring bag may still have a tendency to fall into the receptacle as the bag is filled. In fact, it is not uncommon for the weight of the trash in the bag to pull the upper opening of the bag down into the trash receptacle. Without some mechanism to provide a drawstring that is secured over the upper lip of the trash receptacle, the drawstring bag will always have a tendency to fall into the receptacle as garbage is thrown into the bag. Therefore, it would also be desirable to provide a drawstring that assists in securing the drawstring bag over the upper lip of a trash receptacle.
[0013] In the prior art, it was disclosed to utilize elastic materials as a component of the drawstring for a trash bag to provide a way to secure the upper part of the bag over the upper lip of a trash receptacle. In particular, prior art applications of elastic drawstring are disclosed which provide a pair of large notches at the upper corners of the bag used to pull the elastic drawstring outward from the sides of the bag. In such prior art embodiment, two elastic drawstring pieces are disposed within the hems which run the width of the upper edges of the trash bag. The two pieces of elastic drawstring are joined together at the respective ends of each drawstring to provide a continuous loop. Because of the elasticity of the drawstring, the continuous loop can be extended and fitted over the upper lip of a trash receptacle holding the bag in place. While this method may be effective in certain instances, it differs significantly from the typical configuration of a drawstring trash bag where the drawstring is pulled through the centrally located access cutouts along the upper edges of the bag. The awkward configuration of the prior art bag therefore detracts from its desirability.
[0014] Furthermore, the prior art elastic drawstring bag discussed above has disadvantages that make it less desirable in other respects as well. For example, the notches cut out of the top corners of the bag inherently result in substantial holes in the drawstring bag when closed for disposal. To better illustrate this point, the prior art bag can be compared to a traditional drawstring trash bag, the latter of which is closed by pulling the drawstrings through centrally located access cutouts. When the drawstrings are pulled through the centrally located access cutouts, the upper opening is reduced to a very small opening at the top of the bag. The small size of this single opening prevents smaller debris from falling out of the bag. Also, when the opposing drawstrings are tied together in a traditional drawstring trash bag, the drawstrings reduce the size of the hole and also cover the gap. In contrast, in the prior art elastic drawstring bags, the notches cut out of the upper corners of the bag result in substantial holes at the top sides of the bag when the drawstrings are pulled closed, which can result in debris and trash falling out. Furthermore, unlike the traditional drawstring trash bags, when the prior art elastic drawstring bag is tied, the tied drawstrings do not cover the substantial holes formed by the notches.
[0015] In view of the foregoing, it would be desirable to offer alternatives to elastic drawstring bags known in the prior art. It would be desirable for the alternatives to not require the awkward action of pulling the drawstring out from the corners of the bag, but would still allow the bag to be easily placed over the upper edge of the trash receptacle. Furthermore, it would be desirable for the alternatives to not have substantial holes in the bag when the drawstrings are tied, or secured, together. Additionally, it would be desirable for the consumers to be able to access the elastic drawstrings through access cutouts centrally located along the top of the bag as consumers are accustomed to with non-elastic drawstring trash bags. The present invention is intended to address these issues and desires.
SUMMARY OF THE INVENTION
[0016] The present invention is directed toward an improved construction of an elastic drawstring trash bag. The elastic drawstring trash bag is comprised of a polymeric bag which is made from a first panel and a second panel. A first hem is provided along the upper edge of the first panel. Similarly, a second hem is provided along the upper edge of the second panel. A first elastic drawstring is disposed within the first hem while a second elastic drawstring is disposed within the second hem.
[0017] The two elastic drawstrings are secured within their respective hems by a pair of short seals which are located proximately to the side seals of the bag along the upper edges. The innermost edges of the first and second short seals define the inner boundaries of the short seals. The upper opening width is defined by the distance between these inner boundaries.
[0018] One advantage and feature of the present invention is that the first and second elastic drawstrings of the present invention are not separable from the bag as disclosed in the prior art. This reduces the risk of an elastic drawstring, separated from the bag as in the prior art, catching on another object. Another advantage of the present invention is that it provides an elastic drawstring bag that is familiar to consumers of non-elastic drawstring bags. The elastic drawstring bags should look similar to non-elastic drawstring bags providing customers with familiarity and comfort in the purchase. Embodiments of the elastic drawstring bag contemplated by the present invention have an upper opening with a width that is less than 97% of the width of the rest of the bag (by virtue of the extended short seals). Another aspect of the present invention that is familiar to consumers is the inclusion of access cutouts centrally located along the first and second hems to allow access to the elastic drawstrings disposed within the hems.
[0019] It is contemplated that the present invention may be utilized in ways that are not fully described or set forth herein. The present invention is intended to encompass these additional uses to the extent such uses are not contradicted by the appended claims. Therefore, the present invention should be given the broadest reasonable interpretation in view of the present disclosure, the accompanying figures, and the appended claims.
BRIEF DESCRIPTION OF THE RELATED DRAWINGS
[0020] A full and complete understanding of the present invention may be obtained by reference to the detailed description of the present invention and preferred embodiment when viewed with reference to the accompanying drawings. The drawings can be briefly described as follows.
[0021] FIG. 1 provides a perspective view of the elastic drawstring trash bag as contemplated by the present invention.
[0022] FIG. 2 provides a perspective view of the elastic drawstring trash bag as contemplated by the present invention in relation to a trash receptacle.
[0023] FIG. 3 provides a perspective view of an enlarged version of an upper corner of the elastic drawstring trash bag as contemplated by one embodiment of the present invention.
[0024] FIG. 4 provides a perspective view of an enlarged version of an upper corner of a conventional non-elastic drawstring trash bag as known in the prior art.
[0025] FIG. 5 provides a perspective view of an enlarged version of an upper corner of the elastic drawstring trash bag as contemplated by another embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0026] The present disclosure illustrates one or more preferred embodiments of the present invention. It is not intended to provide an illustration or encompass all embodiments contemplated by the present invention. In view of the disclosure of the present invention contained herein, a person having ordinary skill in the art will recognize that innumerable modifications and insubstantial changes may be incorporated or otherwise included within the present invention without diverging from the spirit of the invention. Therefore, it is understood that the present invention is not limited to those embodiments disclosed herein. The appended claims are intended to more fully and accurately encompass the invention to the fullest extent possible, but it is fully appreciated that certain limitations on the use of particular terms is not intended to conclusively limit the scope of protection.
[0027] Referring initially to FIG. 1 , a perspective view of an elastic drawstring bag 100 is depicted to illustrate an embodiment of the present invention. In the depicted embodiment, the elastic drawstring bag 100 is manufactured from a first panel 102 and a second panel 104 . The first and second panels 102 and 104 are joined at side seals 106 and bottom fold 108 to form the bag. Typically, the elastic drawstring bag 100 is manufactured using a blown-film extrusion process.
[0028] In a blown-film extrusion process, the first panel 102 and the second panel 104 are formed from an extruded polymeric tube, which is flattened as known in the art. Using a combination of transverse cuts and seals across the width of the flattened blown-film polymeric tube, a plurality of bags can be formed. Side seals 106 are formed in the bag, which result in a slight amount of excess polyethylene material to an edge 107 of the first panel 102 and second panel 104 . While this construction method is the preferred method for manufacture, the invention disclosed herein is not necessarily limited to any particular manufacturing method.
[0029] Referring now back to FIG. 1 , an upper edge of the first panel 102 is folded over and sealed to form a first hem 112 . Similarly, an upper edge of the second panel 104 is folded over and sealed to form a second hem 114 . A first elastic drawstring 116 is disposed within the first hem 112 and runs across the width of the first panel 102 . Similarly, a second elastic drawstring 118 is provided within the second hem 114 of the second panel 104 and runs substantially the width of the second panel 104 . The first elastic drawstring 116 and the second elastic drawstring 118 are both preferably provided in a relaxed or substantially relaxed state.
[0030] The respective ends of the first elastic drawstring 116 and the second elastic drawstring 118 are secured within the hems 112 and 114 by a pair of seals, commonly known as the short seals 120 . In general, as the area of the short seals 120 increases, the quality of the bond between the drawstrings 116 and 118 and the panels 102 and 104 should increase as well.
[0031] An enlarged view of an upper corner of a conventional non-elastic drawstring bag is shown in FIG. 4 , as known in the prior art. An enlarged view of an upper corner of an embodiment of the present invention is also shown in FIG. 3 to better illustrate some of the differences. Looking first a FIG. 4 , in conventional non-elastic drawstring bags, the width of the short seals 120 are minimized so as to not use extra plastic, which does not add any capacity to the bag. Therefore, with conventional non-elastic drawstring bags 400 it is undesirable and unnecessary to provide a short seal any larger than the distance from the edge 107 to the side seal 106 of the bag. The short seal 120 of the conventional non-elastic drawstring bags 400 end at interior edge 126 , which is substantially aligned with the side seal 106 of the non-elastic drawstring bag 400 .
[0032] In contrast to a conventional non-elastic drawstring bag 400 , the short seals 120 of the elastic drawstring bag 100 depicted are widened. In the embodiment depicted in FIGS. 1 , 2 and 3 , the short seals 120 are shown extending from the edge 107 , beyond the side seal 106 , to an interior edge 124 of the short seal 120 . Therefore, in the depicted embodiment, the width of the short seal 120 is substantially greater than the distance from the edge 107 to the side seal 106 . However, as depicted in FIG. 5 , it is contemplated that in certain other embodiments the short seals 120 may not be immediately adjacent to the edges 107 and may extend inward from the side seals 106 rather than from the edges 107 .
[0033] Looking now back to FIGS. 1 and 2 , other features of the present invention are disclosed. For example, in addition to the short seals 120 , some embodiments of the present invention are also provided with a plurality of air ventilation slits/holes 122 to allow air built-up in the hem to escape during use. Without such air ventilation slits/holes 122 , the hems could have a tendency to “bubble.” As an additional advantage, the air ventilation holes 122 also permit the non-elastic polyethylene material to stretch and deform to a slightly greater degree as will be discussed below in more detail.
[0034] Unlike prior art elastic drawstring bags, some embodiments of the present invention contemplate an elastic drawstring bag 100 that includes central access cutouts 110 similar to those in conventional drawstrings bags. The central access cutouts 110 make the bag more familiar to a consumer, and the consumer can pull the elastic drawstrings 116 and 118 through the cutouts 110 to close the opening of the bag. In contrast to the prior art, for some embodiments of the present invention, the region of the short seals 120 are not separable from the remainder of the elastic drawstring bag 100 .
[0035] In looking at both FIG. 1 and FIG. 2 , it is important to note that one of the characteristics of the present invention is a reduction in the upper width 152 (when the bag is in a relaxed state) of the bag 100 resulting from the extended short seals 120 . In the typical embodiment of the present invention as depicted, the elastic drawstring bag 100 has a bag proper width 150 , roughly the distance between the side seals 106 of the elastic drawstring bag 100 . The upper opening width 152 (when the bag is in a relaxed state) resulting from the extended short seals 120 is less than that of the bag proper width 150 . In certain preferred embodiments of the present invention, the shorts seals 120 are positioned such that the ratio of the upper opening width 152 (when the bag is in a relaxed state) to the bag proper width 150 is less than 97%, but greater than 94%. In other embodiments, the ratio of the upper opening width 152 (when the bag is in a relaxed state) to the bag proper width 150 may be less than 94%.
[0036] In the depicted embodiment, the relaxed circumference of the upper opening is roughly two times the relaxed upper opening width 152 (when the bag is in a relaxed state), or two times the distance between the interior edges 124 of the short seals 120 . Since the relaxed upper opening width 152 of the present invention is reduced compared to the bag proper width 150 , the relaxed circumference of the upper opening for the depicted elastic drawstring bag 100 is less than the circumference of the upper opening for a conventional drawstring bag 400 . Therefore, the relaxed circumference of the upper opening of the elastic drawstring bag 100 may be reduced to less than the circumference of the trash receptacle 200 .
[0037] Referring now to FIG. 2 , an elastic drawstring trash bag 100 as contemplated by one embodiment of the present invention is shown being placed onto a traditional trash receptacle 200 . The trash receptacle 200 , as is commonplace, has an upper lip 202 that is slightly smaller than the opening of a typical trash bag. In the conventional non-elastic drawstring trash bag 400 , the width of a kitchen-sized bag is approximately 24 inches between side seals 106 . Therefore the conventional non-elastic drawstring bags 400 have a circumferential opening of approximately 48 inches. Therefore, a kitchen sized trash receptacle 200 would typically have an upper lip 202 that is slightly less than 48 inches around thereby allowing the conventional non-elastic drawstring bag 400 to fit over the receptacle 200 but still provide a relatively tight fit.
[0038] Unlike non-elastic drawstring trash bags 400 , the circumference of the upper opening of the depicted embodiment of an elastic drawstring trash bag 100 can be less than the circumference of the upper lip 202 of a trash receptacle 200 . For the embodiment depicted in FIGS. 2 , 3 and 5 , the short seals 120 are positioned and sized to reduce the relaxed upper opening width 152 to less than the bag proper width 150 . Therefore, when the elastic drawstring bag 100 is in its relaxed configuration, the circumference of the upper opening can be less than the upper lip 202 of the trash receptacle 200 due to the reduced upper opening width 152 between the interior edges 124 of the short seals 120 . For non-elastic drawstring bags, it would be impossible to pull the non-elastic drawstrings over the upper lip 202 of the trash receptacle 200 . However, with the elastic drawstrings 116 and 118 , the elastic drawstring bag 100 of the present invention can be pulled over the upper lip 202 .
[0039] The materials of the elastic drawstrings 116 and 118 are chosen to allow the elastic drawstrings 116 and 118 to be stretched over the upper lip 202 even with the reduced distance between the short seals 120 . Thus, when the elastic drawstrings 116 and 118 are circumferentially stretched, the upper opening of the elastic drawstring bag 100 can easily be placed over the upper lip 202 of the trash receptacle 200 .
[0040] In addition to facilitating the application of the bag over the upper lip 202 of a trash receptacle 200 , the elastic drawstrings 116 and 118 also help to maintain the bag on the trash receptacle 200 . In particular, when the elastic drawstrings 116 and 118 are stretched over the upper lip 202 of the trash receptacle 200 and released, the drawstrings 116 and 118 will contract and fit snugly around the trash receptacle 200 .
[0041] As noted, the embodiments depicted herein are not intended to limit the scope of the present invention. Indeed, it is contemplated that any number of different embodiments may be utilized without diverging from the spirit of the invention. Therefore, the appended claims are intended to more fully encompass the scope of the present invention.
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The present invention is directed toward an improved construction of an elastic drawstring trash bag. The elastic drawstring trash bag described herein is comprised of a plastic bag made from two panels. An elastic drawstring is provided within hems running along the top of the two panels. The upper opening of the elastic drawstring bag is reduced (when the bag is in a relaxed state) by decreasing the distance between the interior edges of the short seals used to weld the drawstrings and bag together. Like an ordinary non-elastic drawstring bag, the elastic drawstring is pulled through access cutouts centrally located along the upper edge of the bag. When the bag of the present invention is in a relaxed state, the reduced upper opening width of the elastic drawstring bag is therefore less than bag proper width, allowing a consumer to pull the elastic drawstring bag over the lip of a trash receptacle and allowing the elastic drawstrings to snugly fit around the trash can.
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CROSS-REFERENCE TO RELATED APPLICATION
The present application is a nationalization under 35 U.S.C. §371 of International Application No. PCT/EP2014/056893 filed under the PCT, having an international filing date of Apr. 7, 2014, which claims priority to European Patent Application No. EP 13163927.0, having a filing date of Apr. 16, 2013.
FIELD OF INVENTION
The present disclosure relates to a sliding door, intended for use with a rail system having a rail, which guides a sliding motion of the door, and an attenuation and retraction device, which brakes the sliding motion of the door at a brake position in the vicinity of a door end position and retracts the door to the end position. The sliding door has a pin, which is slideably attached to the door, slideable between a retracted position and an extended position. A tip of the pin is devised to interact with the attenuation and retraction device. The door further has a wheel carried by a wheel holder, which is arranged to move the wheel between a retracted position and an extended position.
BACKGROUND OF INVENTION
A sliding door of the above indicated type is shown in EP-2372064-A1. In that disclosure, the pin is urged against the rail by means of a spring or by means of its own weight. This is done to make sure that, even though the distance between the door and the rail is adjustable, the pin will nevertheless snap into the attenuation and retraction device in a reliable manner.
One problem associated with a door of this kind, is how to improve the smooth operation of the door, and have a functionality with a long length of life, while retaining a reliable attenuation and retraction functionality.
SUMMARY OF INVENTION
One object of the present disclosure is to improve a sliding door of the initially mention kind. More specifically, a sliding door of the initially mentioned kind has a transmission mechanism which interconnects the wheel holder and the pin such that a movement of the wheel, towards the extended position of the wheel, urges the pin towards its extended position. This makes it possible to approximately maintain a desired distance between the tip of the pin and the rail regardless of how the door is adjusted. Still, it is not necessary to urge the pin against the rail by means of a spring or the like. This has advantages, such as not exposing the tip of the pin to excessive wear against the rail, and avoiding any noise produced by the friction between the tip of the pin and the rail.
The wheel holder may be devised to urge the wheel, towards its extended position and against the rail by means of a spring, typically a torsion spring. This allows the wheel/pin combination to be used in a top position, keeping the upper part of the door laterally fixed with regard to the longitudinal extension of the rail.
The transmission mechanism may be arranged to maintain a gap between the tip of the pin and the rail. This ensures reliable operation by presenting the tip of the pin to the attenuation and retraction device in a consistent manner. The maintained gap may, as an example, be in the range 2±0.5 mm.
The pin may be urged towards its retracted position by means of another spring. This makes sure that the pin is out of the way, not extending unnecessarily out of the door.
The transmission mechanism may for instance comprise a transmission lever pivotably suspended at a pivot axis, a first arm of the lever, at one side of the pivot axis, being moved by an abutment on the wheel holder, such that a second arm of the lever moves the pin by resting on an abutment surface of the pin.
The pin may comprise a tip, which is intended to interact with the attenuation and retraction device, a wing portion, and a waist portion, on the other side of the wing portion as seen from the tip. The waist portion is narrower than the wing portion, such that the wing portion can be caught by the attenuation and retraction device to pull the pin further from its retracted position. This allows the pin to interact more reliably with an attenuation and retraction device having a catching function.
The wheel holder and the pin may be mounted together in a cassette. This allows the functionality to be provided as a single component that may be used in different types of doors.
BRIEF DESCRIPTION OF DRAWINGS
For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:
FIG. 1 shows a sliding door arrangement;
FIG. 2 a shows a perspective view of a lid of an attenuation and retraction device;
FIG. 2 b shows an enlarged portion of FIG. 2 a;
FIG. 3 shows a part of a door guided by a rail;
FIGS. 4 a and 4 b show a pin for interaction with an attenuation and retraction device;
FIG. 5 a shows a front view of a wheel cassette for a door;
FIG. 5 b shows an enlarged portion of FIG. 5 a;
FIG. 6 a shows a cross section of the door in FIG. 3 in a first position;
FIG. 6 b shows an enlarged portion of FIG. 6 a;
FIG. 7 shows a cross section of the door in FIG. 3 in a second position;
FIG. 8 is side view of a first side of a wheel cassette with the wheel in a first position;
FIG. 9 is a partial cutaway side view of the wheel cassette of FIG. 8 with the wheel in the first position;
FIG. 10 is a partial cutaway side view of the wheel cassette of FIG. 8 with the wheel in a second position;
FIG. 11 is a partial cutaway side view of the wheel cassette of FIG. 8 with the wheel in a third position;
FIG. 12 is side view of a second side of a wheel cassette of FIG. 8 with the wheel in a first position;
FIG. 13 is side view of the second side of the wheel cassette of FIG. 8 with the wheel in the second position; and
FIG. 14 is partial cutaway side view of the second side of the wheel cassette of FIG. 8 with the wheel in the third position.
DETAILED DESCRIPTION OF THE INVENTION
The principles of the present invention and their advantages are best understood by referring to the illustrated embodiment depicted in FIGS. 1-14 of the drawings, in which like numbers designate like parts.
The present disclosure relates generally to a sliding door arrangement. Such an arrangement is typically used to delimit a niche or recess, which may be provided with shelves and may be used as a closet. Another use for a sliding door arrangement is as a room dividing device providing a semi-removable wall. Needless to say, there are other uses.
FIG. 1 illustrates schematically a sliding door arrangement 1 . Typically, the door arrangement may be used at the end of a room, extending between a first wall 3 and a second wall 5 , and between the floor 7 and the ceiling 9 . In the illustrated case, only two doors 11 , 13 are used, although the number of doors may even exceed five in some applications. The space 15 behind the doors may be provided with shelves and may be used as a closet. When the doors are closed, the space 15 behind the doors is both concealed and protected from dust and the like. The doors may provide mirror panels or decorative panels of different kinds. Usually, the total width of the doors exceeds that of the opening such that the doors overlap each other avoiding any gaps between the doors in their closed position.
The sliding doors 11 , 13 are mounted between a bottom rail 17 and a top rail 19 . As will be shown later, each door may have two top wheels that are resiliently urged towards a track of the top rail 19 and two bottom wheels that rest on a track of the bottom rail 17 . In the illustrated case, the arrangement is fitted between the ceiling and the floor of a room. As will be shown, the wheels are kept in place by wheel holders that are capable of moving the wheels between a more retracted position and a more extended position. The arrangement may also be used, for example, in an opening between two rooms, in which case the top rail 19 may instead be fitted under the top piece of the opening. A further possibility is to attach the top rail to the wall above such an opening.
A sliding door arrangement of this kind may be built in a room from the outset, or may be added later on. Particularly in the latter case, the arrangement may need be adjustable to some extent in order compensate for being used in a not perfectly rectangular opening. For instance, if the second wall 5 is slightly inclined, i.e. deviating slightly from the vertical, the second door 13 may be inclined too, such that its right edge runs parallel with the second wall, thereby avoiding any gap between the second door 13 and the second wall 5 at the rightmost position of the former. This can be done by adjusting either or both of the door's bottom wheels.
FIG. 3 illustrates a part of a sliding door arrangement according to the present disclosure. The door arrangement is provided with at least one attenuation and retraction device 29 . This device is used to provide smooth, silent and accurate operation of the door. The attenuation and retraction device is active in the vicinity of an end position of the door 11 , i.e. where the door reaches the left wall 3 . When the door 11 approaches this end position it reaches a brake position at which point a pin 31 of the door interacts with the attenuation and retraction device which begins to absorb the kinetic energy of the door 11 . The pin 31 is slideably attached to the door and is moveable towards the rail between a retracted position and an extended position. At the same time as the kinetic energy is absorbed, the attenuation and retraction device pulls in the door 11 to the end position where the left edge of the door is in contact with or in close proximity to the left wall 3 . This feature results in the door being completely shut thanks to the retraction function. At the same time, door 11 is prevented from slamming into the wall 3 thanks to the attenuating/braking function. It should be noted that a door of this type may typically weigh up to 30 kg or even more. Attenuation and retraction devices providing a soft-closing function are, as mentioned, per se well known in many applications such as drawers and the like.
The upper left wheel 33 of the door 11 need not be placed at the side edge of the door, which means that the rail 19 which guides the door 11 need not extend all the way to the wall 3 . Thereby, the attenuation and retraction device 29 can be placed in an extension of the rail 19 . The attenuation and retraction device 29 interacts with the tip of the pin 31 , braking the door and closing the door as is well known per se. An example of the operation of an attenuation and retraction device is shown in EP-2372064-A1 and EP-2372066-A1. It has been suggested to urge the pin 31 against the rail 19 to ensure that the pin snaps into the slot of the attenuation and retraction device.
In the present disclosure, the attenuation and retraction device is instead devised with a catching function that positions the tip of the pin 31 in the attenuation and retraction device 29 in such a way that proper interaction is ensured.
The lid 35 of the attenuation and retraction device is shown in FIG. 2 a . The lid comprises at least one slot 37 ; in the illustrated case, the lid has two slots. The attenuation and retraction device is intended to be placed in the extension of the rail 19 (position indicated) and the slot 37 is open, at an entry point 39 , towards the rail.
In order to accomplish the catching function, the lid 35 comprises a catching device in the form of a ramp portion 41 which is arranged to interact with the pin 31 . In the ramp portion 41 , which is shown enlarged in FIG. 2 b , the longitudinal edges 43 of the slot 37 rise towards the door further from the top surface of the lid 35 , in the direction towards the rail 19 , until, at a tip 45 of the edge 43 at the entry point 39 , the distance to the base of the attenuation and retraction device (and typically to the roof (ceiling 9 of FIG. 1 ) if the device is top mounted) is at its maximum. The ramp portion extends along a first part of the slot 37 . After this part, the slot edges may be flat and parallel with the attenuation and retraction device lid.
A pin 31 that is devised to interact with an attenuation and retraction device of this kind is illustrated in FIGS. 4 a and 4 b . FIG. 4 a shows a side view, i.e. as seen perpendicularly to the direction of travel of a door, and FIG. 4 b shows a front view, as seen from the attenuation and retraction device.
The pin 31 has a tip 47 that is intended to connect to the features in the interior of the attenuation and retraction device that provides the braking/closing function such as described in EP-2372064-A1.
The portion 49 at the opposite end of the pin as seen from the tip 47 is arranged to be slideably fitted to the door, typically to a wheel cassette that is attached to the door. This may be arranged by providing an opening in the cassette that has a similar cross section as the corresponding portion of the pin 31 . As will be described, a stop that prevents the pin from leaving the door, and a spring that pulls the pin 31 to an innermost position may be provided.
The pin 31 further has a wing portion 51 that is adapted to interact with the ramp portion 41 of the attenuation and retraction device lid 35 . The portion below the wing portion 51 may be defined as a waist portion 53 . The width of the wing portion 51 is wider than the width of slot 37 in the lid, but the width of the waist portion 53 is not. Therefore, the tips 45 (see FIG. 2 b ) of the slot edges may enter into the waist portion 53 of the pin 31 . As the pin 31 passes the ramp portion 41 the pin is pulled out of the door by the slot, such that the tip 47 of the pin 31 reaches further into the slot after passing the entry point 39 . The ramp portion 37 of the slot thus positions the tip 47 of the pin 31 reliably inside the attenuation and retraction device to interact therewith.
To further improve the catching function, the pin 31 can be devised with a wing portion 51 where the wings, which extend laterally with regard to travelling direction of the door, have a tapered portion 55 at the edge that faces the attenuation and retraction device. The wings thus taper upwards, as illustrated in FIG. 4 a , such that they more easily slip into the lid slot at the entry point. Alternatively, the edge of the wing that faces the attenuation and retraction device can be angled upwards. In both cases the surfaces of the pin that will be pulled by the slot edges are angled to be more exposed to the pulling surfaces under the slot edges. In principle, the wings may be angled in this way as a whole, and may interact with slot edges that are straight, without a ramp portion, as a ramp is then instead provided on the pin. This requires that the slot edges extend far enough from the base of the attenuation and retraction device to catch the front end of the wings.
Additionally, the front end 57 of the pin 31 at the waist portion can be tapering in the direction facing the attenuation and retraction device, such that the waist portion is more easily fitted in between the slot edges.
It should be noted that a ramp portion could be devised differently. For instance, the slot of the lid could be flat, and a ramp portion could be devised e.g. at one side of the slot, interacting with a portion protruding from the pin laterally with regard to the slot. This would also provide a catching function on the lid. Another way to accomplish a catching function could be to use a magnet in the attenuation and retraction device attracting a ferromagnetic pin, or vice versa.
FIG. 5 a shows a front view of a wheel cassette 59 for a door. The cassette which will be described in greater detail later includes the wheel 33 which may be spring loaded and the pin 31 . The cassette may be produced as a component that can be fitted to different varieties of doors, e.g. different door material, sizes etc. However, it would also be conceivable to include the corresponding components directly in the door.
The FIG. 5 b shows an enlarged portion of FIG. 5 a . As is shown, there is provided a gap 61 between the wheel 33 , where the wheel is intended to be supported by the rail, and the tip 47 of the pin 31 . This is provided by a steering function as will be described later. Typically, the gap 61 is intended to be 2±0.5 mm, although different sizes are conceivable. Thanks to this gap, the pin does not wear against the rail.
The gap is also shown in FIG. 6 a , which shows a cross section of a door before reaching a position where the attenuation and retraction device becomes activated. The door, the rail, and the attenuation and retraction device are shown in cross-section while the wheel cassette with included components are not shown in cross section.
As is shown, the wheel 33 is urged against the rail, and the pin 31 is in a relatively retracted position. As is more clearly shown in the enlarged FIG. 6 b , the wing portion 51 of the pin is located above the tip of the ramp 45 . Thereby, the wing portion 51 will follow the trajectory illustrated with a dotted arrow in FIG. 6 b when reaching the ramp portion, pulling the pin 31 further out of the cassette. This positions the tip 47 of the pin 31 reliably inside the attenuation and retraction device. The attenuation and retraction device begins to interact with the pin, and the arrangement finally reaches the position shown in FIG. 7 where the door is shut. Note that the pin is now in a relatively extended position as compared with FIG. 6 a.
FIGS. 8-14 present functionalities in a wheel cassette 63 . The cassette 63 may be built as a generally flat box, which provides features allowing the cassette to be mounted on the door, and supports the included components. The cassette has a wheel holder 65 which extends out of the interior of the cassette 63 as shown in FIG. 8 . The wheel holder 65 is pivotably attached to the cassette 63 at a wheel holder pivot 67 axis, where it is suspended between the side walls of the cassette 63 . A torsional spring 69 urges the wheel holder 65 , counter-clockwise as shown in FIG. 9 , towards its most extended position, thereby urging the wheel 33 towards the rail, that would be placed above the cassette shown in FIG. 9 . FIG. 9 shows the position where the wheel is most extended, an inner portion 81 , at the opposite side of the pivot 67 as seen from the wheel, resting against the cassette floor 83 .
As is shown in the cut-out in FIG. 14 , a compression spring 77 urges the pin 31 inwards, towards the interior of the cassette. In FIG. 9 however, the force of the spring (located behind the pin in the view in FIG. 9 ) is overcome by a transmission mechanism, which includes an abutment 75 on the wheel holder 65 , displaced from the wheel holder pivot 67 , and a pivoting transmission lever 71 , which is pivotably attached to the cassette 63 at a pivot axis 73 . The abutment 75 in FIG. 9 abuts one side of the transmission lever 71 causing the arm to pivot clockwise when the wheel holder turns counter-clockwise. The other end of the lever, which is connected to the pin 31 by resting on an abutment surface 85 (see FIG. 4 b ), thereby forces the pin outwards. By means of this function, the pin 31 is urged, against the force of the compression spring 77 , out of its retracted position, such that it is positioned close to the rail, but not in contact with the same. Thereby, the pin is well positioned to interact with the attenuation and retraction device. When this happens, the catching function in the attenuation and retraction device pulls the pin out further, thereby further compressing the spring 77 . Although a constant gap between the wheel and the pin tip, in the direction towards the rail, would be advantageous, some deviations during the extending of the wheel can be allowed. When the attenuation and retraction device pulls the pin further out, this gap is eliminated, but at that point, the pin does not face the rail.
Other ways of accomplishing the transmission function are conceivable, e.g. providing the abutment 75 as a cam surface, using cogwheels, etc.
FIGS. 9-11 show how the transmission mechanism makes the pin follow the wheel downwards. The more the wheel is pivoted away from the extended position, the further the pin is retracted by the influence of the compression spring.
FIGS. 12-14 show corresponding positions as FIGS. 9-11 but seen from the other side of the wheel cassette. In FIG. 14 , a cut-out exposes the pin 31 and the compression spring 77 . The compression spring 77 is located in a recess in the pin and between the floor of the recess and a stop 79 that extend from the cassette side wall and into the recess, This stop further prevents the pin 31 from leaving the cassette.
The present disclosure is not restricted to the above described examples and may be altered and varied in different ways within the scope of the appended claims. For instance, while the above embodiments show a top-wheel arrangement, where the wheel runs on a rail above the door and is urged against this rail by a torsional spring, bottom wheel arrangements are also possible. If so, the torsional spring is replaced by an adjustment mechanism that e.g. by means of a screw allows the end user to adjust the extent of the wheel extension of the door, e.g. in the way illustrated in aforementioned EP-2372064-A1. A transmission mechanism as illustrated above may nevertheless be provided to ensure that the pin is adjusted corresponding to the adjustment of the wheel.
The above illustrated function where the position of the pin is adjusted in accordance with the adjustment of the wheel may also be used together with attenuation and retraction devices that do not have a special catching function to pull the pin out. For instance, by providing a slightly raised attenuation and retraction device where the functions intended to interact with the tip of the pin are located slightly higher than the point where the rail ends, reliable interaction can be ensured with an accurate positioning of the pin tip close to the rail.
Although a system with two rail tracks, and correspondingly an attenuation and retraction device with two slots are shown above, more or less tracks could be used. Instead of a compression spring as shown in FIG. 14 , the pin's own weight could be used to pull the pin back into the door.
Although the invention has been described with reference to specific embodiments, these descriptions are not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternative embodiments of the invention, will become apparent to persons skilled in the art upon reference to the description of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiment disclosed might be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims.
It is therefore contemplated that the claims will cover any such modifications or embodiments that fall within the true scope of the invention.
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A sliding door for use with a rail system, having a rail, which guides a sliding motion of the door, and an attenuation and retraction device, which brakes the sliding motion of the door at a brake position in the vicinity of a door end position and retracts the door to the end position. The sliding door includes a pin, which is slideably attached to the door, slideable between a pin retracted position and a pin extended position, a tip of the pin interacting with the attenuation and retraction device. The door further includes a wheel carried by a wheel holder, which is arranged to move the wheel between a wheel retracted position and a wheel extended position. A transmission mechanism interconnects the wheel holder and the pin such that a movement of the wheel, towards the wheel extended position, urges the pin towards the pin extended position.
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FIELD OF THE INVENTION
The invention relates to aqueous fluid suspensions of polymeric thickeners. In particular the invention relates to the use of fluidized suspensions of polysaccharide mixtures in paper coating compositions.
BACKGROUND OF THE INVENTION
U.S. Pat. Nos. 4,799,962, 4,883,536 and 4,883,537 disclose aqueous fluid mixtures and suspension containing polyethylene oxides or salts. U.S. Pat. No. 4,154,899 describes the use of pigment, clay and modified starch ether for coating compositions which are applied to paper during manufacture. European Patent Application EP 307-795 describes a pigment dispersion used for paper coating which can contain modified starch, galactomannan, methylcellulose (MC) or carboxymethylcellulose (CMC). A quaternary starch ether is employed in the papermaking method of U.S. Patent 4,840,705.
It is further known from Aqualon® publication 250-llC, Natrosol®--Hydroxyethylcellulose--A Nonionic Water-Soluble Polymer--Physical and Chemical Properties, that this cellulosic can be used in coating colors and size press solutions to control water binding, solids holdout and rheology. Hercules Incorporated product data publication 456-2, Natrosol® R in Pigmented Coatings for Paper and Paperboard, contains viscosity data useful for selection of a grade of product for a papermaking application.
U.S. Pat. Nos. 4,834,207, 4,228,277 and 4,243,802 describe hydrophobically modified hydroxyethylcellulose (HMHEC) for use in latex paints and shampoos. Chain lengths from C 4 to C 24 can provide the hydrophobic modification.
Still it remained for the present invention to teach how two or more anionic and nonionic polysaccharides provide a fluid suspension applicable for paper manufacture.
SUMMARY OF THE INVENTION
It is an object of the invention to provide an aqueous fluidized polymer suspension comprising at least one low molecular weight polysaccharide and at least one nonionic cellulose ether polymer with a salt content below 10% by weight wherein the suspension remains fluid and pourable.
It is preferred for paper coatings that the nonionic cellulose ether polymer be a water soluble hydrophobically modified alkylcellulose, alkylhydroxyalkylcellulose or hydroxyalkylcellulose.
A process for preparing a fluidized polymer suspension involves the steps:
(1) preparing an aqueous solution of a low molecular weight polysaccharide containing up to 10% by weight ammonium or alkali salt from the group of carbonate, sulfate, phosphate or formate; and
(2) stirring the solution while adding a nonionic cellulose ether to prepare a fluidized polymer suspension.
An anionic cellulose and hydrophobically modified cellulose ether mixture can be added as a sole thickening agent or be used in combination with other thickening agents for paper coating compositions. Sodium carboxymethylcellulose is a preferred anionic polymer and hydrophobically modified hydroxyethylcellulose is a preferred nonionic cellulose ether polymer.
DETAILED DESCRIPTION OF THE INVENTION
This invention is concerned with fluid aqueous suspensions comprising at least two water-soluble polysaccharides that possess distinct properties. One of the polysaccharides in the Multi-Polysaccharide Suspension (MPS) is of a relatively low molecular weight (MW) and is dissolved in the continuous aqueous phase. One or more nonionic cellulosic polymers is present in a form of dispersed particles in the suspension. The suspension either contains no added salt or a relatively low level of inorganic salt or mixture thereof (less than 10 wt. %). The suspensions typically have a total polysaccharide concentration of 20 wt. % or higher, and are fluid and pourable. All of the Multi-Polysaccharide Suspensions (MPSs) described herein can be readily dispersed and dissolved in aqueous solvent.
The continuous aqueous phase of the MPS contains a dissolved low-MW polysaccharide, an inorganic salt at a concentration of 0 (salt-free) to 8 wt. % (low-salt), and minor amounts of additives (less than 1 wt. %) which may include defoamer, dispersant, preservative, and/or suspension stabilizers such as xanthan gum. The dissolved low-MW polysaccharide can be a CMC (anionic, e.g., Ambergum® 1570 or Ambergum® 3021), a hydroxyethylcellulose (HEC) (nonionic, e.g., AQU-D3097), a degraded carboxymethyl guar (anionic, e.g., AQU-D3144), all of which are available from the Aqualon Company, and a starch derivative (cationic starch such as Amaizo® 2187). These dissolved low-MW polysaccharides generally have a solution viscosity of less than 10,000 mPa.s as measured at a concentration of 15 wt. % using a Brookfield viscometer at 12 rpm. The inorganic salt (or salt mixture) for use in the preparation of the referred suspensions may be sodium formate, sodium carbonate, sodium sulfate, potassium carbonate, diammonium phosphate, or others.
The dispersed phase contains one or more Dispersed, Nonionic Cellulosic Polymer (DNCP). The DNCP can be a hydroxypropylcellulose (e.g., Klucel® HPC), methylcellulose or methylhydroxypropylcellulose (e.g., Culminal™ MC or Benecel™ MHPC), methylhydroxyethylcellulose (e.g., Culminal™ or Benecel™ MHEC), hydrophobically modified hydroxyethylcellulose (e.g., Natrosol® Plus 330 HMHEC), or hydroxyethylcellulose (e.g., Natrosol® HEC). Insolubilization of the DNCP, which is less hydrophilic than the dissolved polysaccharide, is primarily a result of the difference in water solubility between the dissolved polysaccharide and the DNCP. Further reduction in DNCP swelling or dissolution, where necessary, may be attained by dissolving in the aqueous phase a relatively small amount of salt, which helps reduce the amount of water accessible to the DNCP. The dissolved polysaccharide also causes an increase in the liquid phase viscosity, which reduces the rate of settlement of the suspended polymer particles and, hence, improves suspension stability.
A MPS can be prepared by adding a DNCP to a vigorously agitated solution of the low-MW polysaccharide in which an amount of inorganic salt (or salts) at a concentration of 0 to 8 wt % has been previously added. A fluid suspension is obtained after the mixture is stirred for a period of 15 to 60 minutes. A small amount of additives such as defoamer, dispersant, or suspension stabilizer may be added if necessary. Additives such as defoamer may be added before or after the DNCP has been dispersed into the aqueous solution.
The suspensions can be readily pumped and redissolved in aqueous media; the dissolution of the suspension is substantially faster than that of the nonionic cellulosic polymer. These properties can lead to a significant improvement in the efficiency of polymer solution makeup operations, and reduce or eliminate difficulties often associated with handling of dry powders of cellulosic polymers, such as powder dusting and lumping of wet particles during mixing.
This invention is intended to introduce (1) a new methodology of preparing easily processable suspensions of cellulosic polymers that contain a relatively low level of added salt, and (2) a means to produce uniform mixtures of cellulosic polymers which can provide different functionalities in a certain application.
The MPSs are of use in various applications where one of the following conditions exist:
(a) Each of the different polysaccharides in the suspension imparts essential functionality to the end application;
(b) The DNCP (suspended polymer) is primarily responsible for the key functionality; the dissolved polysaccharide allows (1) suspending of the functional DNCP without using a high level of salt (high salt level not tolerated in concerned application); (2) fast and ready dissolution of the suspended polymer; and/or (3) other desirable properties that are not critical to the end application, such as added thickening/water holding or improved particle dispersion (as protective colloid in the end formulation).
In common with other industries the paper and paperboard manufacturers seek to improve productivity and lower mill cost. One of the problems limiting their productivity has been the necessity to employ solid thickeners in preparing suitable coating compositions.
Ideally, a paper coating thickener/co-binder should bring about desired rheological properties that allow easy mixing, pumping and recycling, and, most importantly, proper metering of the pigmented coating. It should also lead to a coating structure which is less prone to water loss when in contact with paper web during the coating operation. A suitable combination of coating rheology and water retention capability then leads to well-controlled coat weight and good coater runnability. An ideal thickener/co-binder should also impact the coating structure in such a way that coated paper properties such as gloss, opacity, and coating strength may be enhanced. Moreover, there is an increasing need for thickeners/co-binders in a fluid liquid form to facilitate rapid, automated coating preparation in today's high speed coating operations.
Cellulosic derivative such as CMCs have been known for years to be effective as paper coating thickeners. As derivatives of cellulose, they have inherent affinity towards the paper substrate upon which the pigmented coating is placed. This nature, together with their water binding property and long chain structure, is largely responsible for their effectiveness as thickeners/co-binders. However, the ever increasing demands for increased coating speed and enhanced coating properties call for new products that can simultaneously provide several different but essential functions. These demands sometimes cannot be satisfied with one single cellulosic polymer, and a product consisting of more than one cellulosic derivative, such as MPS, is needed. The following illustrates how the MPSs HMHEC/CMC and HMHEC/MC/CMC suspensions meet the current needs for liquid products and various essential coating properties.
The inclusion of more than one cellulosic polymer with distinct properties in the suspension makes it possible to attain a combination of desirable coating properties that are not readily obtainable from a single polymer. For instance, a HMHEC has been shown to give a combination of strong low-shear coating structure, which helps reduce penetration of coating into the paper substrate, and low flow resistance under high shear conditions typical of blade metering at high coating speeds. It also gives generally high thickening efficiency, which means only a relatively low dosage is required to thicken the coating to a certain target viscosity, by virtue of its self-associating nature. These properties make the HMHEC an effective light-weight coating (LWC) for papers. However, when a HMHEC is used as the sole thickener/co-binder in a clay-containing coating formulation, its highly clay adsorbing nature often results in a relatively low aqueous liquid viscosity, and hence a somewhat limited water retention capability (indicated by a relatively short water retention time for the coating). Improvement in water retention capability may be achieved by using a MPS also consisting of a CMC.
Suspensions can be readily dispersed and dissolved in a large mass of aqueous liquid. Thus, they can be added to the pigmented coating at different stages of the mixing process, making them adaptable to various coating preparation conditions. This nature makes the MPSs suitable for highly automated coating preparation processes.
It was a surprising result to find how efficient the composition and process of the invention were in meeting the aims of the paper industry. Uniform paper surfaces can be produced using a MPS as the thickener. Higher productivity can be achieved without sacrifice of quality or significantly increasing costs using the low salt combination of anionic and nonionic cellulosic polymer.
Cellulosic thickening agents having suitable hydrophobic modification are available from the Aqualon Company. A preferred modified cellulosic is Natrosol® Plus HMHEC. An Aqualon publication, Natrosol® Plus 250-18A, describes how this material functions as an associative thickener in paint, but gives no suggestion of the present invention.
A suitable low molecular weight polysaccharide is carboxymethylcellulose (CMC), available from Aqualon Company as Ambergum® 1570 or Ambergum® 3021. However, the suspending polymer is not limited to anionic materials since low molecular weight nonionics such as hydroxyethylcellulose (HEC) or cationics, such as Amaizo® 2187 available from American Maize, may also be used in the practice of the invention.
The suspending polymer (low molecular weight polysaccharide), whether anionic, nonionic or cationic, must be available in a state such that a 15% by weight solution gives a Brookfield viscosity at room temperature below 10,000 mPa.s.
Depending upon the needs of the paper manufacturer, it may be desirable to use one or more hydrophobically modified cellulosics in combination with one or more anionic cellulosics such as CMC. Similarly other low molecular weight polysaccharides, such as hydroxyethylcellulose (HEC), carboxymethylguar (CM Guar) or starch derivatives, can be used as the dispersing medium for other cellulosic polymers such as methylcellulose (MC), methylhydroxyethylcellulose (MHEC), methylhydroxypropylcellulose (MHPC), hydroxypropylcellulose (HPC) or hydroxyethylcellulose (HEC).
Typical ingredients for paper coating compositions in addition to thickeners include: pigments (e.g., kaolin clay, calcium carbonate, gypsum, titanium dioxide, etc.), polymeric binder (e.g., styrene-butadiene latex, protein, starch, etc.), lubricants such as glycols and fatty acids, insolubilizers and defoamers. Once prepared as a coating composition, it is usual practice in the industry to measure viscosity and rheology properties of the composition prior to an actual test of the composition. In this way a body of knowledge is built up by comparison of such results with the actual quality and reproduceability provided by any of the compositions tested.
In addition to paper coating, it is possible to find uses for MPSs in the areas of latex paints, food, pharmaceutical, personal care, and others. In these applications, the polysaccharides involved in the MPS are normally employed to provide viscosity, rheology control, water retention, and/or formulation stability. The low salt content of the invention can be highly desirable since adverse effects of salt on the colloid chemistry of the concerned formulation may be minimized. With little or no added salt in the polysaccharide suspension, health concerns due to salt content will be minimal. Thus a salt-free or low-salt MPS of HPC, MC, or MHPC can be used in food and personal care products.
Examples 1 to 8 describe the compositions and physical properties of various types of MPSs. Total polymer concentration of these MPSs range from 20 to 30 wt. %. The weight ratio of DNCP to dissolved polysaccharide ranges from about 2.1 to 0.5. The pH values vary from 6.2 to 10.7. Brookfield viscosities measured at 6 rpm fall between 700 and 12,000 mPa.s (cPs). Example 9 illustrates the use of MPS as thickeners/co-binders in paper coating formulations.
Example 1
Salt-Free Suspension Containing HPC and CMC
This example illustrates the preparation of a fluid suspension of hydroxypropylcellulose (HPC) in a solution of sodium carboxymethylcellulose (CMC). The composition of this MPS is given in Table 1. It was prepared by adding the fine HPC powders into a vigorously agitated CMC solution, followed by continued mixing for approximately 30 minutes. Minor amounts of defoamer and suspension stabilizer (xanthan gum) were predissolved in the CMC solution before the addition of HPC powders.
The resulting MPS was found to dissolve in aqueous media significantly faster than the corresponding dry HPC product. The time required for the suspension to attain 90% of its equilibrium solution viscosity in cold water was ca. 10 minutes, compared to over one hour for the dry HPC. Since this composition does not contain any added salt, it may be used as thickener, binder, or process aid in personal care, food, pharmaceutical, and other products, where a high level of salt can cause health concerns.
The low-MW CMC used in this example was supplied as a solution product which had a solution viscosity of ca. 1000 mPa.s at a concentration of 15 wt. %. The Klucel® hydroxypropylcellulose (HPC) and the CMC solution product, with a trade name of Ambergum® 1570, are both available from Aqualon. The defoamer, Hercules DF 285, is available from Hercules Incorporated. The xanthan gum was obtained from Kelco. All the suspension viscosities given in this and the following examples were measured using a Brookfield LVT viscometer at a rotating speed of 6 rpm, and are reported in mPa.s (cPs).
TABLE 1______________________________________Composition of Salt-Free MPS ContainingHydroxypropylcellulose and CMC______________________________________HPC, Klucel ® HXF 12.0CMC, in Ambergum ® 1570 12.0Defoamer, Hercules DF 285 0.2Xanthan Gum, Kelzan ® S 0.4Methyl parasept (preservative) 0.1Water 75.3pH 6.2Viscosity 6100Wt. % polysaccharide 24.4______________________________________
Example 2
Suspending a HMHEC in a CMC Solution
A MPS containing a hydrophobically-modified hydroxyethylcellulose (HMHEC) and a low-MW CMC was prepared as described in Example 1. An amount of inorganic salt at a level up to 7 wt. % was added to the composition to supplement the low-MW CMC in insolubilizing the HMHEC. Small amounts of defoamer and preservative (methyl parasept) were also added to help maintain the suspension stability. The HMHEC and CMC used in this example are available from Aqualon Company
The MPS was made by (1) preparing an aqueous solution which contained predetermined amounts of CMC and methyl parasept, (2) dissolving the salt in the aqueous solution, which took ca. 20 to 30 minutes, (3) gradually adding the dry HMHEC solids into the aqueous solution which was under vigorous agitation, and (4) adding the defoamer. The resulting suspension was then mixed for ca. 30 minutes to ensure uniform dispersion. Typical pH and Brookfield viscosity values for the suspensions are given in Table 2.
TABLE 2______________________________________Compositions of MPSs Containing HMHEC and Low-MW CMC 2-A 2-B 2-C 2-D______________________________________HMHEC, Natrosol ® Plus 330 10.0 14.0 10.0 10.0CMC, in Ambergum ® 1570 10.0 6.0 10.0 10.0Sodium carbonate 5.0 6.2 -- --Sodium sulfate -- -- 7.0 --Diammonium phosphate -- -- -- 7.0Defoamer 285 0.2 0.2 0.2 0.2Methyl Parasept 0.1 0.1 0.1 0.1Water 74.7 73.5 72.7 72.7pH 10.3 10.1 6.9 7.6Viscosity 8400 4000 9300 5400Wt. % polysaccharide 20.0 20.0 20.0 20.0______________________________________
MPSs of this type have been shown to be useful in paper coating applications. The use of a HMHEC/CMC MPS as a paper coating thickener/co-binder is illustrated in Example 9.
Example 3
Suspending a MC or MC Derivative in a CMC Solution
This example describes the preparation of MPSs containing a low-MW CMC (as described in Example 1) and a methylcellulose or a methylcellulose derivative such as methylhydroxypropylcellulose (MHPC) or methylhydroxyethylcellulose (MHEC).
TABLE 3______________________________________Compositions of MPSs Containing CMC and MC,MHPC, or MHEC 3-B 3-C 3-D______________________________________MC, Culminal ® 400 10.0 -- --MHPC, Benecel ™ MP943W -- -- 11.0MHEC, Culminal ® C3033 -- 10.0 --CMC, in Ambergum ® 1570 10.0 10.0 11.0Sodium carbonate 2.0 2.0 --Sodium sulfate -- -- 3.5Hercules DF 285 0.2 0.2 0.2Xanthan Gum, Kelzan ® S 0.2 0.2 0.4Methyl parasept 0.1 0.1 0.1Water 77.5 77.5 73.8pH 10.3 10.3 6.7Viscosity 4900 5500 9100Wt. % polysaccharide 20.2 20.2 22.4______________________________________
These MPSs also demonstrated faster dissolution in aqueous media than the corresponding dry MC, MHEC, or MHPC. For instance, the time required for MPS 3-C (Table 3) to attain 90% of its equilibrium viscosity was less than five minutes, in comparison to about 40 minutes for the dry Benecel™ MHEC product. With the relatively low salt contents, such MPSs may find commercial use in personal care and paper coating applications.
Example 4
HEC Suspended in CMC Solutions
The following MPSs demonstrate the feasibility of preparing fluid suspensions that contain a hydroxyethylcellulose (HEC) and a low-MW CMC. The procedure for preparing the MPSs is similar to that described in Example 1. A CMC with a very low MW, which gave a solution viscosity of about 1000 cPs at a concentration of 30 wt. %, was used in this example. This low MW CMC is available as a solution product (Ambergum® 3021) from Aqualon Company. The HEC products are also available from Aqualon.
TABLE 4______________________________________MPSs Containing a Suspended HEC and Dissolved CMC 4-B 4-C 4-D______________________________________HEC, Natrosol ® 250 GR 10.0 -- --HEC, Natrosol ® 250 MXR -- 10.0 --HEC, Natrosol ® 250 HBR -- -- 10.0CMC, in Ambergum ® 3021 10.0 10.0 10.0Sodium carbonate 5.0 -- --Diammonium phosphate -- 4.0 5.0Water 75.0 76.0 75.0pH 10.0 7.1 7.4Viscosity 2400 2200 2000Wt. % polysaccharide 20.0 20.0 20.0______________________________________
Example 5
HPC Suspended in HEC Solution
This example describes the preparation of a MPS containing a HPC and a low-MW HEC. Success in preparing such a MPS indicates that the dissolved polymer in a MPS does not have to be ionic in nature.
The procedure of preparation was the same as that described in Example 1. The HEC used had a solution viscosity of ca. 1000 cPs at a polymer concentration of 30 wt. %. Both the HEC and HPC are available from Aqualon.
TABLE 5______________________________________Suspension of HPC in Solution of a Low-MW HEC 5-A______________________________________HPC, Klucel ® HXF 10.0HEC, in AQU-D3097 20.0Sodium carbonate 2.0Methyl parasept 0.1Water 67.9pH 8.9Viscosity, (mPa.s) 2400Wt. % polysaccharide 30.0______________________________________
Example 6
Two Nonionic Cellulosic Polymers Suspended in CMC Solution
It is possible to have two nonionic cellulosic polymers suspended in a solution of a low-MW cellulosic polymer. The compositions shown in Table 6 are examples of such terpolymer MPSs. These compositions, in general, contained a HMHEC and a MC or MC derivative in the dispersed phase and a low-MW CMC (such as Ambergum® 1570) in the aqueous phase. The procedure for the preparation of these suspensions was similar to that of Example 1. The DNcPs were added to the aqueous CMC solution in sequence before the addition of the defoamer.
TABLE 6______________________________________MPSs Containing Two DNcPs and One Dissolved Polymer 6-A 6-B 6-C 6-D______________________________________HMHEC, Natrosol ® Plus 10.0 10.0 10.0 10.0MC, Culminal ® 400* 5.0 -- -- --MHEC, Culminal ® C3033* -- 8.0 -- --MHPC, Culminal ® 6000PR -- -- 5.0 5.0CMC, in Ambergum ® 1570 7.0 7.0 7.0 7.0Sodium carbonate 6.0 6.5 6.0 --Diammonium phosphate -- -- -- 8.0Hercules DF 285 0.3 0.3 0.3 0.3Methyl Parasept 0.1 0.1 0.1 0.1Water 71.6 68.2 71.6 69.6pH 10.1 9.8 9.9 7.6Viscosity 5800 11600 5300 5700Wt. % polysaccharide 22.0 25.0 22.0 22.0______________________________________ *The dry polymer products were ground in the laboratory to give finer particles to reduce settling of the suspended particles.
Example 7
HMHEC Suspended in Low-MW Guar Derivative
A depolymerized, low-MW guar derivative, a carboxymethylated guar (CM guar) in this example, has been used to suspend a HMHEC with the aid of 6 parts of sodium carbonate. This example manifests that the dissolved polymer is not necessarily limited to cellulosic derivatives.
The low-MW CM guar is available from Aqualon as a solution product (AQU-D3144). At a CM guar concentration of 34 wt. %, this aqueous solution had a Brookfield viscosity of 220 cPs.
TABLE 7______________________________________MPS Containing a Low-MW CM Guaras the Dissolved Polysaccharides 7-A______________________________________HMHEC, Natrosol ® Plus 330 10.0CM guar, in AQU-D3144 10.0Sodium carbonate 6.0Hercules DF 285 0.2Methyl parasept 0.1Water 73.7pH 9.6Viscosity 700Wt. % polysaccharide 20.0______________________________________
Example 8
HMHEC Suspended in Starch Solution
This example describes the use of another non-cellulosic polysaccharide as the dissolved polymer, a low-MW, cationic starch manufactured by American Maize (Amaizo®°2187). To prepare this suspension, a stock solution of the cationic starch (a dry product) was first prepared using a steam cooker. Make-up water and the salt were added to the stock solution, followed by the addition of the DNCP, a HMHEC.
TABLE 8______________________________________HMHEC Suspended in Starch Solution 8-A______________________________________HMHEC, Natrosol ® Plus 330 10.0Cationic starch, Amaizo ® 2187 14.3Sodium carbonate 4.3Methyl parasept 0.1Water 71.3pH 9.9Viscosity 4200Wt. % polysaccharide 24.3______________________________________
Example 9
Use of MPSs as Thickener/Co-Binders for Paper Coatings
This example demonstrates the use of two types of MPSs as thickeners/co-binders in paper coating formulating. One type of MPS contains HMHEC and CMC. The other contains HMHEC, CMC and MHEC.
HMHEC/CMC MPS
Associative thickeners (i.e., hydrophobically modified cellulose ethers which associate with themselves) are useful in the practice of the present invention, providing improved rheology in paper coating compositions applied with a metering blade, rod or air knife. They provide high thickening efficiency with high pseudoplasticity in high solids content coating compositions. During blade coating a hydrophobically modified cellulosic allows lower blade pressures to be used with a resulting improvement in coating quality at high speeds. Lower blade pressure resulting from the use of associative thickeners can reduce water loss to the paper stock, web breaking and streaking, particularly at high coating speed. However, when a HMHEC is used as the sole thickener/co-binder in a clay-containing coating formulation, its highly clay adsorbing nature often results in a relatively low aqueous liquid viscosity, and hence a somewhat limited water retention capability.
The coating containing MPS 2-A has been found to give good runnability at a high coating speed of 4500 feet per minute in a coater trial using a cylindrical laboratory coater (CLC). A fairly low coat weight of ca. 5.0 pounds per 3300 sq. ft of paper was readily attained at this high speed with a moderate blade pressure, indicating a low and manageable flow resistance of the coating. The paper sample produced with MPS 2-A was observed to have improved coated paper properties over that of the coating containing only HMHEC or CMC. As shown in Table 11, MPS 2-A gave the best combination of sheet gloss, print gloss, opacity, and ink pick strength. The Test Methods section gives a more detailed description of these measurements.
The above data show that a MPS containing HMHEC and CMC not only can satisfy the industry's need for a liquid product, but also can lead to improved runnability and/or coated paper quality. A MPS has additional advantages in that (1) the presence of more than one cellulosic polymer makes it possible to optimize coating properties for a large variety of paper products, and (2) the use of a relatively low level of salt in the MPS avoids excessive flocculation of pigments or the latex binder, which may occur with high salt suspensions.
HMHEC/MHEC/CMC MPS
It has been found that a terpolymer MPS comprising of a HMHEC, a MC or MC derivative such as MHEC, and a low-MW CMC can also be an very effective thickener/co-binder for paper coatings. The MC derivative, which is a good binder and water retention aid, can work in combination with the HMHEC and CMC to provide good wet coating runnability and coated paper quality. For example, one such MPS (MPS 6-B) has been found to give a good balance of thickening efficiency, high shear viscosity and water retention in coating Formulation II (see Table 10).
The terpolymer MPS has been observed in a CLC coater trial to give good high speed runnability and coating properties. As shown in Table 11, the coated paper sample prepared with MPS 6-B showed clearly superior coated paper properties over that of another sample produced using a commercial CMC. The use of MPS 6-B as the thickener/co-binder has caused a substantial improvement in the ink pick resistance. This improvement in coating strength is thought to arise, at least in part, from the excellent binding property of the MC derivative.
Preferred Product
MPSs 2-A to 2-D and MPSs 6-A to 6-D are the preferred products for use as paper coating thickeners/co-binders.
TABLE 9______________________________________Paper Coating Formulations* I II______________________________________Hydrafine ® 100 --Hydrasperse ® -- 40Hydraprint ® -- 50Ansilex ® 93 -- 5Ti-Pure ® R-931 -- 5Dispex ® N40 -- 0.15Dow 620 13 7Flowco ® 501 0.5 --Hercules 831 0.2 0.2Thickener varied variedBrookfield Viscosity 2300 1000______________________________________*All ingredients in the test formulas were on a dry or100% active basis; The concentration of the ingredientswere reported in parts per 100 parts of pigment; pH ofthe coating was adjusted to 8; Total solids was 60% byweight; The use level of thickener was varied to obtainthe target Brookfield viscosity as measured at 100 rpm. Hydrafine: Pigment, No. 1 kaolin clay, J. M. Huber Corp.Hydrasperse: Pigment, No. 2 kaolin clay, J. M. Huber Corp.Hydraprint: Pigment, delaminated clay, J. M. Huber Corp.Ansilex 93: Pigment, calcined clay, Engelhard Corp.Ti-Pure R-931: Pigment, TiO.sub.2, DuPontDow 620: Binder, styrene-butadiene latex, Dow Chemical Co.Flowco ® 501: Lubricant, calcium stearate dispersion, MallinckroftHercules 831: Defoamer, Hercules Incorporated
TABLE 10______________________________________Properties of Wet CoatingsThickener Dose* Hercules* MRT*______________________________________(Formula I)HMHEC 0.5 31.9 6CMC, low MW (7LT) 2.0 65.2 14MPS 2-A 1.0 43.7 11(Formula II)HMHEC 0.4 38.9 5CMC, low MW 0.8 69.5 16MPS 6-B 0.6 58.4 8______________________________________ *Dose: Parts per hundred parts of pigment. Hercules: Hercules high shear viscosity in mPa.s. WRT: Water Retention Time in seconds.
TABLE 11______________________________________Coated Sheet Properties of Supercalendered Paper Samples* PrintThickener Gloss Opacity IGT Gloss______________________________________(Formula I)CMC, low MW 65.4 83.5 77.5 83.3HMHEC 62.6 85.3 84.0 80.3MPS 2-A 65.4 85.3 84.0 84.6(Formula II)CMC, Low MW 53.1 81.3 19.4 60.0MPS 6-B 55.2 81.8 29.0 66.9______________________________________
Test Methods
Kaltec Scientific, Inc., 22425 Heslip Drive, Novi, Mich. 48050 supplies parts and rheogram paper for use with the Model ET24-6 Hercules® Hi-Shear Viscometer which is in common use by the paper industry for evaluation of coating compositions.
All paper samples were coated on one side using a cylindrical laboratory coater (manufactured by Sensor and Simulation Products, Tacoma, Wash.) at a speed of from 4000 to 4500 feet per minute. The coat weight for both formulations was approximately 5.0 pounds per 3300 square feet. The coated paper samples were supercalendered with four passes at 160° F. and 1500 psi. Gloss of the paper samples was measured using a Gardner Glossmeter at 75° angle, and was reported as % reflectance of the incident light. The opacity was measured using a Diano Opacimeter according to TAPPI test method T-425. The IGT ink pick resistance was measured using a 32 Pa.s oil ink, and was reported as velocity-viscosity product at the onset of coating picking by the ink. A higher IGT pick resistance value indicates a higher coating strength which is desirable for high speed printing.
Water retention times of paper coatings were measured using a conductivity method which was a modification of the S. D. Warren Water Retention Test Method, i.e., J. C. Stichfield, R. A. Clift, J. J. Thomas, TAPPI, 41 (2), 1958, p. 77.
The CMC used in this test had a nominal molecular weight of approximately 110,000 (Brookfield viscosity of 2% solution was 40 mPa.s); this CMC product is commercially used as coating thickeners and is available from Aqualon Company.
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A nonionic cellulose ether such as hydroxyalkylcellulose, alkylcellulose or an alkylhydroxyalkylcellulose hydrophobically modified with a C 4 to C 24 alkyl or an arylalkyl group is suspended by a low molecular weight polysaccharide and below 10% by weight salt to provide a fluidized polymer suspension. The process for manufacture involves preparing an aqueous polysaccharide solution and adding a nonionic cellulose ether while stirring. Anionic, nonionic and cationic suspending polymers such as CMC, CM Guar, HEC and cationic starch may be used. Sodium carbonate is a preferred salt.
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CROSS REFERENCE
This application is a divisional application of U.S. application Ser. No. 13/325,336 filed Dec. 14, 2011.
FIELD OF THE INVENTION
The embodiments of the present invention relate to an electric vehicle equipped with an energy-producing system for producing energy for use to recharge batteries powering the electric vehicle.
BACKGROUND
For many years, electric vehicles have been discussed as the possible solution to the United States' (and other countries') dependence on oil. However, one concern, among many, related to electric vehicles is the short battery life. Short battery life means that electric vehicles are limited to short vehicle trips between charges.
Accordingly, there is a need for extending the battery life associated with electric vehicles. Advantageously, the system of extending the battery life should be self-facilitating.
SUMMARY
The embodiments of the present invention relate to an energy-producing system comprising an axle configured to be driven by the vehicle's wheels when in motion. The axle supports a series of wind-catching cups contained within an aerodynamic housing configured to direct air to the cups while also increasing the air speed. During vehicle motion, the cups are acted upon by rushing air causing the rotation of the axle such that the rotation may be transferred into energy via a generator/alternator linked thereto. A series of similarly polarized magnets integrated on said cups and proximate thereto further maintain the axle in motion during intermittent vehicle stops.
The system according to the embodiments of the present invention directs the generated energy into the batteries used to drive the vehicle. In this manner, the life of the batteries between charges is increased as is the distance the vehicle can travel between charges. The system may be fabricated with an electric vehicle or added after market.
Other variations, embodiments and features of the present invention will become evident from the following detailed description, drawings and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A-1D illustrates perspective, top, front and rear views, respectively, of a system according to the embodiments of the present invention;
FIG. 2 illustrates a perspective, exploded view of the system according to the embodiments of the present invention;
FIG. 3 illustrates a front, exploded view of the system according to the embodiments of the present invention;
FIG. 4 illustrates a view of an inner wheel and pinion according to the embodiments of the present invention;
FIG. 5 illustrates a partially transparent perspective view according to the embodiments of the present invention;
FIG. 6 illustrates a perspective view of a primary axle according to the embodiments of the present invention;
FIG. 7 illustrates a side view of the system according to the embodiments of the present invention;
FIG. 8 illustrates cups of the type associated with the system according to the embodiments of the present invention; and
FIG. 9 illustrates a block diagram of a system according to the embodiments of the present invention.
DETAILED DESCRIPTION
For the purposes of promoting an understanding of the principles in accordance with the embodiments of the present invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. Any alterations and further modifications of the inventive feature illustrated herein, and any additional applications of the principles of the invention as illustrated herein, which would normally occur to one skilled in the relevant art and having possession of this disclosure, are to be considered within the scope of the invention claimed.
The embodiments of the present invention involve a system for generating energy useable to maintain the battery charge associated with the electric vehicle. The components making up the system may be fabricated of any suitable materials, including metals, alloys, composites, plastics and combinations thereof. The components of the system may be created using technologies which include machining, molding, rapid prototyping, casting, etc. The system described herein utilizes multiple features to generate energy for charging electric batteries to drive an associated vehicle.
FIGS. 1A-1D show perspective, top, front and rear views of an energy-generating system 100 according to the embodiments of the present invention. A housing 105 is configured with a front opening 110 to capture and direct rushing air towards cups 115 configured to capture air. The housing 105 also protects the contained components from damage. From front to back, the opening 110 may be tapered (wide to thin) to increase air velocity therethrough thus increasing the energy output of the system 100 as described below. In one embodiment, the system 100 is mounted in an offset relationship to a wheel axle 150 out of the way of any drive train mechanisms associated with the vehicle. In one embodiment, the axle 150 of the vehicle inserts through oppositely positioned openings 120 in the housing 105 and openings 176 in cover plates 175 with ends inserting into vehicle wheels 101 . As described below, the axle 150 rotates within said openings 120 , 176 such that the housing 105 remains stationary. A system axle 125 inserts through a second pair of oppositely positioned openings 130 in the housing 105 and openings 121 in a cover plate 175 proximate each vehicle wheel 101 and extends generally parallel to said axle 150 . At each end, the system axle 125 joins pinions 135 (See FIG. 4 ) in communication with a vehicle's wheel rim 140 having gear teeth 145 configured to receive the pinions 135 to drive the system axle 125 while the pinions 135 remain stationary relative to the wheel rim 140 . While not shown, the system axle 125 may include a U-Joint to accommodate rough terrain.
FIGS. 2 and 3 show exploded perspective and front views of the system 100 according to the embodiments of the present invention. The system 100 broadly comprises the housing 105 , system axle 125 , cups 115 supported by the system axle 125 , a first set of magnetic strips 155 attached to said cups 115 , a second set of magnetic strips 160 positioned on the housing 105 proximate to said first set of magnetic strips 155 on the housing 105 , pulley 170 configured to drive a belt, chain or similar mechanisms able to drive a generator/alternator 108 (shown in FIG. 9 ), cover plates 175 and pinions 135 . Other system items include ratchet pawls 180 , dust washers 185 , axle bearings 190 and ball cups 195 .
As best shown in FIG. 6 , the system axle 125 includes a series of spacers 126 in-between which the cups 115 are attached. In one embodiment, the cups 115 are attached at each end to the spacers 126 . As seen in FIG. 8 , the attachment may be facilitated by pins 116 extending from ends of the cups 115 wherein said pins 116 are positioned to insert into openings in said spacers 126 . Other connection means such as screws, rivets, adhesives, magnets may be used as well. A space 128 between two center spacers is configured for receipt of a belt, chain, strap or similar article 107 capable of driving a generator and/or alternator 108 attached thereto. The space 128 accommodates a pulley 170 . In this manner, as the axle 125 rotates, the belt 107 drives the generator/alternator 108 to transform mechanical energy into electrical energy for storage in the vehicle's electric batteries 205 . An opening 127 in the housing 105 accommodates the passage of the belt, chain, strap or similar article which connects the axle 125 to the generator/alternator 108 allowing the rotation of the axle 125 to drive the generator/alternator 108 .
The first set of magnetic strips 155 attached to said cups 115 work along with the second set of magnetic strips 160 positioned proximate thereto. In one embodiment, the second set of magnetic strips 160 act to repel and/or attract the first set of magnetic strips attached to said cups 115 thus urging the cups 115 to move. In one embodiment, the second set of magnetic strips 160 are attached to upper and lower inner surfaces of the housing 105 in proximity to the edges of the cups 115 as shown in FIG. 5 . In this manner, the cups 115 with the first set of magnet strips 155 on edges thereof tend to continue moving as the second set of magnetic strips 160 positioned proximate thereto repel and/or attract the magnetic strips 155 on the edges of the cups 115 . Such an arrangement maintains the axle 125 in motion during periods when the vehicle is at rest (i.e., at a stop sign or light). Such continuous motion causes less energy to be used to re-start the rotation of the axle 125 and causes the generator/alternator 108 to continue to transfer mechanical energy into electrical energy.
The cups 115 , as shown in FIG. 8 , can take on various sizes (e.g., short or long) and shapes. The cups 115 include a defined cavity 117 configured to capture rushing air entering the front opening 110 of the housing 105 . FIG. 7 shows twelve cups 115 attached to the axle 125 between one set of spacers 126 . It is understood that more or less cups 115 may be attached to the axle 125 between spacers 126 . FIG. 7 shows the pinion 135 , cover plate 175 , first set of magnetic strips 155 and second set of magnetic strips 160 . As referenced above, in one embodiment, the housing 105 is mounted rear of the vehicle's drive system on a rear axle. To accomplish the rear mount, the pinions 135 are positioned in opposite rims 140 rear of the drive axle 150 . Other mount positions are conceivable as well.
FIG. 9 shows a block diagram 200 detailing the broad aspects of the system 100 and one method for transferring mechanical energy to electrical energy for storage in the vehicle's batteries 205 . The system 100 broadly comprises the system axle 125 driven by the system components as described above. A belt 107 (or similar article) is driven by system axle 125 and thereby drives a generator/alternator 108 . The generator/alternator 108 may be any suitable generator/alternator 108 configured to transform rotational/mechanical energy into electrical energy. An electrical conduit 215 transfers the electrical energy output of the generator/alternator 108 to the vehicle's batteries 205 which receive the electrical energy for current use or stores the electrical energy for later use.
In another embodiment, the system 100 may be used as a source of electricity for a home site or camp ground. In such an embodiment, the drive wheels of the vehicle are elevated to prevent the vehicle from moving. Belts over slightly deflated drive wheels are used to drive one or more generators while the vehicle's accelerator is depressed using suitable means therefore. The output of the one or more generators may then be used to provide electricity to a camp site or house or RV.
Although the invention has been described in detail with reference to several embodiments, additional variations and modifications exist within the scope and spirit of the invention as described and defined in the following claims.
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An energy-producing system comprising an axle configured to be driven by an electric vehicle's wheels when in motion. The axle supports a series of wind-catching cups contained within an aerodynamic housing configured to direct air to the cups while also increasing the air speed. During vehicle motion, the cups are acted upon by rushing air causing the rotation of the axle such that the rotation may be transferred into energy via a generator/alternator linked thereto. A series of similarly polarized magnets integrated on said cups and proximate thereto further maintain the axle in motion during short vehicle stops. The system extends the life of the batteries between charges as well the distance the vehicle can travel between charges.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation in part of U.S. Ser. No. 13/248,648, filed Sep. 29, 2011 and currently pending, entitled Method Of Treatment Of Wooden Items, by Emery, Raymond, et al., which is hereby incorporated by reference; a continuation in part of U.S. Ser. No. 12/714,592, filed Mar. 1, 2010 and issued as U.S. Pat. No. 8,141,604 on Mar. 27, 2012, entitled Method Of Manufacture For Wooden Gunstocks, by Emery, Raymond, et al., which is hereby incorporated by reference; and a continuation in part of U.S. Ser. No. 12/686,124, filed Jan. 12, 2010, now abandoned, entitled Improved Method Of Manufacture For Wooden Gunstocks, by Emery, Raymond, et al., which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Technical Field
[0003] The invention relates generally to the field of wooden items, such as musical instrument components, gunstocks, tools, and the like, and is directed to a method of treatment of wood in preparation of manufacture of wooden items. More specifically, the invention is directed to a method for heat treating suitable wood to achieve desirable characteristics for the wooden items made thereof while preserving the aesthetics of natural wood.
[0004] 2. Description of Prior Art
[0005] Wood used in the manufacture of musical instruments, gunstocks, tool handles, and other high end items needs to be both structurally sound and aesthetically pleasing. Especially for musical instruments and gunstocks, wooden components must be sufficiently hard, have low moisture content and low moisture absorption properties, must be highly stable (that is, resistant to shrinkage and swelling), and be insect resistant. The shrinking and expansion of components of a musical instrument can alter the sound of the instrument and prevent it from producing a musically pleasing sound, and the shrinking and expansion of a gunstock, however slight, can affect the accuracy of the firearm.
[0006] Because wood is often not sufficiently hard, with low moisture content and absorption properties, and may be unstable and susceptible to shrinking and expansion, manufacturers of high end items have recently opted to use synthetic materials, which are more likely to achieve the desired properties. Nevertheless, using wood for high end items is still desirable, for their aesthetics and tactile qualities, as well as historical fidelity, and therefore a method of manufacture of wooden items that overcomes the deficiencies of traditional wooden items is desired.
[0007] One method for decreasing the susceptibility of wooden items to moisture and rot is to chemically treat the wood before fashioning it into a finished item. A common method of chemically treating wood is the “pressure treatment” method, in which the wood is treated with chemicals such as arsenic and chromium (Chromate Copper Arsenate), alkaline copper quaternary (ACQ), or copper azole preservative, applied to the wood using a vacuum and pressure cycle to force the chemicals deep into the inner portions of the wood. Other chemicals may also be used. While this method tends to improve the weather resistance as well as insect and rot resistance of the wood, it does not address swelling and shrinkage issues. The toxicity of the chemicals used also renders this method less than desirable.
[0008] Another method for decreasing the susceptibility of wooden items to moisture and rot is to treat the wood in a non-pressurized manner with preservatives. These preservatives may be chemically based or derived from naturally occurring compounds, such as oils, and the preservatives are applied to the surface of the wood. While this method tends to be simpler than the pressure treatment method, and potentially uses less toxic preservatives, it fails to ensure a uniform application of the preservative into the inner portions of the wood. It also does not address swelling and shrinkage issues.
[0009] There is known in the art yet another method for decreasing the susceptibility of wooden items to moisture and rot, which is preferable to the above-described methods. Wood may be heat treated prior to being fashioned into a gunstock. European Patent Application EP 0 922 918 A1 (Aug. 3, 1998), to Lallukka, Tero, for “Method for heat treatment of timber”, discloses such a method for treating wood.
[0010] Wood is made up, generally, of cellulose, lignin, and extractives. Cellulose (and hemicelluloses) are carbohydrates that are structural components in wood. Cellulose constitutes 40-50% and hemicelluloses 25-35% of wood. The composition and contents of hemicelluloses vary from one wood species to another. During heat treatment, both groups undergo changes, but the majority of the changes occur in hemicelluloses. After heat treatment, the wood contains a substantially lower amount of hemicelluloses. As a result of this, the amount of fungi susceptible material is significantly lower, providing one reason for heat-treated woods improved resistance to fungal decay compared with normal kiln dried wood. With the degrading of the hemicelluloses, the concentration of water-absorbing components decreases and the dimensional stability of treated wood is also improved compared to normal kiln dried wood. The decomposition temperature of the hemicelluloses is about 200-260° C., and the corresponding temperature for cellulose is about 240-350° C. Lignin holds the wood cells together. Lignin constitutes 20-30% of wood. During heat treatment, bonds between components of lignin are partially broken. Of all wood's constituents, lignin has the best ability to withstand heat. Lignin's mass starts to decrease when the temperature exceeds 200° C. Wood also contains minor amounts of small-molecule constituents known as extractives. Extractives constitute less than 5% of wood. Extractives are not structural components in wood, and most of the compounds evaporate easily during the heat treatment.
[0011] Heat treating wood changes the structure of the wood in a manner which is desirable for the manufacture of many different kinds of high end wooden items. During heat treatment, wood undergoes mild pyrolysis, resulting in degradation of hemicelluloses and amorphous cellulose, modification of lignin structures, and evaporation of extractives from the wood. The lignin and hemicelluloses become less hygroscopic. Surface hardness increases, moisture is 10%-50% less than in untreated wood, resins dry out or evaporate, less absorption of moisture occurs, as well as reduced molding, improved weather resistance, and moisture deformation is reduced by 30% to 90% over untreated wood.
[0012] Thermally modified wood has a lower density than untreated wood. This is mainly due to the changes of the mass during the treatment when wood loses its weight. Density decreases as higher treatment temperatures are used. This leads to overall lighter weight of the wood. The strength of wood has a strong correlation with density. Because thermally modified wood has slightly lower density after the treatment, it is somewhat less strong than untreated wood. However, the change in the weight-to-strength ratio is minimal. The strength of wood is also highly dependent on the moisture content and its relative level below the grain saturation point. Thermally modified wood benefits due to its lower equilibrium moisture content. Heat treated wood is therefore sufficiently strong for use in high end wooden items.
[0013] Heat treatment also significantly reduces the tangential and radial swelling of wood. Heat-treated wood consequently has very low shrinkage. The water permeability of heat-treated wood is 20-30 percent lower than that of normal kiln dried wood. Thermally modified wood is resistant to insects (which are attracted to the extractives of untreated wood; such extractives are largely evaporated away during heat treatment).
[0014] Species of tree which are suitable for thermal modification include American Beech ( Fagus Grandifolia ), Red Maple ( Acer Rubrum ), Black Walnut ( Juglans Nigra ), Hard maple ( Acer Saccharum ), Turkish Walnut a/k/a English Walnut ( Juglans Regia ), California Walnut ( Juglans Californica ), Yellow Birch ( Betula Alleghaniensis ), and Claro Walnut ( Juglans Hindsii ). Other species are also suitable for thermal modification.
[0015] Some woods naturally exhibit the preferred characteristics described above. For example, with regard to wood hardness, Madagascar ebony ( Diospyros celebica ) measures 3220 on the Janka Hardness Scale. (The Janka Hardness Scale measures the resistance of a type of wood to withstand denting and wear, measuring the force required to embed an 11.28 mm (0.444 in) steel ball into wood to half the ball's diameter; the measurement is expressed in pounds-force (lbf).) In contrast, the hardness of hard maple ( A. saccharum ) is only 1450 on the Janka Hardness Scale. A soft wood such as eastern white pine ( Pinus strobus ) has a hardness of only 380 on the Janka Hardness Scale.
[0016] However, ebony falls under the Lacey Act of 1900, which was amended in 2008 to include provisions to curtail illegal logging. The amended Lacey Act prohibits all trade in plant and plant products (e.g., furniture, paper, or lumber) that are illegally sourced from any U.S. state or any foreign country; requires importers to declare the country of origin of harvest and species name of all plants contained in their products; and establishes penalties for violation of the Act, including forfeiture of goods and vessels, fines, and jail time. Because ebony is relatively rare, procurement of ebony often is not done consistent with the provisions of the Lacey Act. Ebony is thus difficult to obtain, and the legal supply is not sufficient to meet demand.
[0017] As a result, manufacturers have a need for a substitute wood that meets the characteristics of ebony, but which is in greater supply. One species that is an acceptable substitute is ipe ( Tabebuia Serratifolia ), a common specie of wood found abundantly in South America. Ipe has a hardness on the Janka Hardness Scale of 3684, making it sufficiently hard. However, while ipe has a naturally dark color it is nowhere near the true black of ebony. Ipe therefore must be modified to achieve proper coloration. Thermally modifying ipe brings it closer to the color of ebony than any other species of wood while retaining the hardness that is necessary. In addition, thermal modification dries the wood and reduces its susceptibility to shrinkage or swelling, as well as making it more insect resistant. In addition to ipe, there are a few other species of wood that are sufficiently hard and sufficiently abundant that they can be acceptable substitutes for ebony when they are thermally treated. These include purpleheart ( Peltogyne paniculata ), Brazilian walnut ( Swartzia tomentosa ), and cumaru ( Dipyeryx odorata ).
[0018] In summary, heat treating wood reduces its moisture content; it reduces the ability of the wood to absorb environmental moisture; it increases the surface hardness of the wood; it increases the overall stability of the wood (that is, minimizes expansion and shrinkage); it causes the wood to become less dense, and therefore lighter; and it makes the wood less susceptible to rot and insect predation. It also allows for aesthetically pleasing coloration changes to the wood. Heat treatment of wood further accomplishes these desirable characteristics without the use of toxic chemicals.
[0019] From the foregoing it is evident that there is a need for a method of treatment of wood for the manufacture for wooden items, particularly components for musical instruments, gunstocks, tool handles, and other high end items.
[0020] It is therefore an objective of the present invention to provide a method of heat treatment of wood for the manufacture of wooden items.
[0021] It is a further objective of the present invention to provide a method of heat treatment of wood for the manufacture of components for musical instruments, gunstocks, tool handles, and other high end items.
[0022] It is a further objective of the present invention to provide a method of heat treatment which darkens the color of wood.
[0023] It is a further objective of the present invention to provide a method that increases the surface hardness of the wood.
[0024] It is a further objective of the present invention to provide a method that reduces the moisture content of wooden items to minimize expansion and shrinkage and to increase the stability thereof.
[0025] It is a further objective of the present invention to provide a method that makes the wood less susceptible to environmental moisture.
[0026] It is a further objective of the present invention to provide a method that makes the wood less susceptible to rot and insect predation.
[0027] It is a further objective of the present invention to provide a method that decreases the density and therefore the weight of the wood.
[0028] It is a further objective of the present invention to provide a method which does not use toxic chemicals to treat the wood.
[0029] Other objectives of the present invention will be readily apparent from the description that follows.
SUMMARY
[0030] The present invention discloses a method of treatment of wood in preparation for the manufacture for wooden items. In one aspect, the present invention is directed to a method comprising the steps of obtaining a piece of wood of an appropriate species of tree; drying said piece of wood until said piece of wood has a moisture content of less than fifteen percent (15%); placing said piece of wood into an oven heated to between 150° C. and 240° C.; allowing said piece of wood to be heated by the oven for between 2 and 96 hours such that said piece of wood achieves a temperature of at least 150° C.; removing said piece of wood from the oven and allow said piece of wood to cool to substantially room temperature; and cutting said piece of wood into a finished wooden item.
[0031] In an alternate aspect of the present invention, the method comprises the additional step of creating a rough wooden item after selecting a piece of wood of an appropriate species of tree, then drying the rough wooden item, heating it, allowing it to cool, and then manufacturing the rough wooden item into a finished wooden item.
[0032] In yet another alternate aspect of the present invention, the method comprises the steps of first obtaining a pre-fabricated rough wooden item, then drying the wooden item, heating it, allowing it to cool, and then and then manufacturing the rough wooden item into a finished wooden item.
[0033] Other features and advantages of the invention are described below.
DESCRIPTION OF DRAWINGS
[0034] FIG. 1 is a flow chart of the steps of one embodiment of the method.
[0035] FIG. 2 depicts several exemplars of items that can be manufactured from wood treated by the method of the present invention.
DESCRIPTION OF THE INVENTION
[0036] The method disclosed herein is for the treatment of wood to be used in the manufacture of wooden items, for example, components of musical instruments 1 , gunstocks 110 , tool handles 80 , and the like. The basic method comprises the following steps:
[0037] Step A. obtain a piece of wood of an appropriate species of tree having certain characteristics desirable for the manufacture of wooden items, namely, hardness, strength, and stability, and the wood should be aesthetically pleasing.
[0038] Suitable species of tree include African Blackwood ( Dalbergia melanoxylon ), African Zebrawood ( Microberlinia brazzavillensis ), Afzelia ( Afzelia africana ), Agba ( Gossweilerodendron balsamiferum ), American Basswood ( Tilia americana ), American Beech ( Fagus grandifolia ), American Elm ( Ulmus americana ), American Hornbeam ( Carpinus caroliniana ), American Sycamore ( Platanus occidentalis ), Applewood ( Malus sylvestris ), Arizona Cypress ( Cupressus arizonica ), Australian Blackwood ( Acacia melanoxylon ), Australian Ironwood ( Casuarina equisetifolia ), Australian Sandalwood ( Santalum spicatum ), Ayan ( Distemonanthus benthamianus ), Bald Cypress ( Taxodium distichum ), Balsam Fir ( Abies balsamea ), Balsam Poplar ( Populus balsamifera ), Bigleaf Mahogany ( Swietenia macrophylla ), Bigtooth Aspen ( Populus grandidentata ), Black Alder ( Alnus glutinosa ), Black Ash ( Fraxinus nigra ), Black Cherry ( Prunus serotina ), Black Ironwood ( Krugiodendron ferreum ), Black Locust ( Robinia pseudacacia ), Black Maple ( Acer nigrum ), Black Oak ( Quercus velutina ), Black Poplar ( Populus nigra ), Black Spruce ( Picea mariana ), Black Walnut ( Juglans nigra ), Black Willow ( Salix nigra ), Blackbean ( Castanospermum australe ), Blackbutt ( Eucalyptus pilularis ), Blackgum ( Nyssa sylvatica ), Bloodwood ( Brosimum paraense ), Blue Ash ( Fraxinus quadrangulata ), Blue Gum ( Eucalyptus saligna ), Bocote ( Cordia alliodora ), Boxelder ( Acer negundo ), Boxwood ( Buxus sempervirens ), Brazilian walnut ( Swartzia tomentosa ), Brazillian Rosewood ( Dalbergia nigra ), Brazilwood ( Caesalpinia echinata ), Brown Mallet ( Eucalyptus astringens ), Bubing a ( Guibourtia demeusei ), Bur oak ( Quercus macrocarpa ), Butternut ( Juglans cinerea ), California Laurel ( Umbellularia califormica ), California Walnut ( Juglans californica ), Camphor Laurel ( Cinnamomum camphora ), Canyon Live Oak ( Quercus chrysolepis ), Cape Chestnut ( Calodendrum capense ), Carapa ( Carapa guianensis ), Catalina Ironwood ( Lyonothamnus floribundus ), Celery Top Pine ( Phyllocladus aspleniifolius ), Chestnut ( Castanea dentata ), Chestnut Oak ( Quercus prinus ), Chinese Mahogany ( Toona sinensis ), Chinkapin Oak ( Quercus muhlenbergii ), Cigar Tree ( Catalpa speciosa ), Claro Walnut ( Juglans hindsii ), Coachwood ( Ceratopetalum apetalum ), Cocobolo ( Dalbergia retusa ), Common Ash ( Fraxinus excelsior ), Common Horse-chestnut ( Aesculus hippocastanum ), Common Ironwood ( Pau ferro ), Corkwood ( Leitneria floridana ), Corsican Pine ( Pinus nigra ), Cucumbertree ( Magnolia acuminata ), cumaru ( Dipyeryx odorata ), Desert Ironwood ( Olneya tesota ), Eastern Cottonwood ( Populus deltoides ), Eastern Hemlock ( Tsuga canadensis ), Eastern Hop hornbeam ( Ostrya virginiana ), Eastern Redcedar ( Juniperus virginiana ), Eastern White Pine ( Pinus strobus ), English Elm ( Ulmus procera ), English Oak ( Quercus robur ), European Aspen ( Populus tremula ), European Beech ( Fagus sylvatica ), European Larch ( Larix decidua ), European Yew ( Taxus baccata ), Flooded Gum ( Eucalyptus grandis ), Flowering Dogwood ( Cornus florida ), Goncalo Alves ( Astronium fraxinifolium ), Gray Birch ( Betula populifolia ), Green Ash ( Fraxinus pennsylvanica ), Greenheart ( Chlorocardium rodiei ), Grey Ironbark ( Eucalyptus paniculata ), Guanandi ( Calophyllum brasiliense ), Hackberry ( Celtis occidentalis ), Hard maple a/k/a Sugar Maple ( Acer saccharum ), Hawaiian Sandalwood ( Santalum freycinetianum ), Hinoki Cypress ( Chamaecyparis obtusa ), Honey Locust ( Gleditsia triacanthos ), Hoop Pine ( Araucania cunninghamii ), Huon Pine ( Lagarostrobos franklinii ), Hybrid Poplar ( Populus canadensis ), Indian Bean Tree ( Catalpa bignonioides ), Indian Rosewood ( Dalbergia sissoo ), Indian Sandalwood ( Santalum album ), Ipe ( Tabebuia serratifolia ), Iroko ( Milicia excelsa ), Ironbark ( Eucalyptus sideroxylon ), Jacaranda ( Jacaranda brasiliana ), Jack Pine ( Pinus banksiana ), Japanese Larch ( Larix kaempferi ), Jarrah ( Eucalyptus marginate ), Jatobá ( Hymenaea courbaril ), Karri ( Eucalyptus diversicolor ), Kauri ( Agathis australis ), Kaya ( Torreya nucifera ), Kingwood ( Dalbergia cearensis ), Lacewood ( Grevillea robusta ), Laurel Oak ( Quercus laurifolia ), Lawson's Cypress ( Chamaecyparis lawsoniana ), Lebombo Ironwood Androstachys johnsonii ), Lignum Vitae ( Guaiacum officinale ), Limba ( Terminalis superba ), Loblolly Pine ( Pinus taeda ), Lodgepole Pine ( Pinus contorta ), Longleaf Pine ( Pinus palustris ), Marblewood ( Marmaroxylon racemosum ), Marri ( Corymbia calophylla ), Mediterranean Cypress ( Cupressus sempervirens ), Merbau ( Intsia bijuga ), Mockernut Hickory ( Carya alba ), Monterey Pine ( Pinus radiata ), Mountain Hemlock ( Tsuga mertensiana ), Noble Fir ( Abies procera ), Nootka Cypress ( Callitropsis nootkatensis ), Northern Whitecedar ( Thuja occidentalis ), Norway Spruce ( Picea abies ), Nuttall's Oak ( Quercus texana ), Obeche ( Triplochiton scleroxylon ), Ohio Buckeye ( Aesculus glabra ), Okoumé ( Aucoumea klaineana ), Olive ( Olea europaea ), Oregon Ash ( Fraxinus latifolia ), Overcup Oak ( Quercus lyrata ), Pacific Coast Mahogany ( Swietenia humilis ), Pacific Dogwood ( Cornus nuttallii ), Pacific Silver Fir ( Abies amabilis ), Padauk ( Pterocarpus soyauxii ), Panga-panga ( Millettia stuhlmannii ), Paper Birch ( Betula papyrifera ), Parana Pine ( Araucaria angustifolia ), Pear ( Pyrus communis ), Pecan ( Carya illinoinensis ), Pehuén ( Araucaria araucana ), Persian Ironwood ( Parrotia persica ), Pignut Hickory ( Carya glabra ), Pink Ivory ( Berchemia Zeyheri ), Pitch Pine ( Pinus rigida ), Plains Cottonwood ( Populus sargentii ), Ponderosa Pine ( Pinus ponderosa ), Post Oak ( Quercus stellata ), Pumpkin Ash ( Fraxinus profunda ), Purple Heart ( Peltogyne altissima ), Purpleheart ( Peltogyne paniculata ), Quaking Aspen ( Populus tremuloides ), Queensland Maple ( Flindersia brayleyana ), Queensland Walnut ( Endiandra palmerstonii ), Red Alder ( Alnus rubra ), Red Cedar ( Toona ciliata ), Red Cherry ( Prunus pensylvanica ), Red Elm ( Ulmus rubra ), Red Mahogany ( Eucalyptus resinifera ), Red Maple ( Acer rubrum ), Red Oak ( Quercus rubra ), Red Pine ( Pinus resinosa ), Red Spruce ( Picea rubens ), Redgum ( Liquidambar styraciflua ), Redheart ( Erythroxylon mexicanum ), Redwood ( Sequoia sempervirens ), Rimu ( Dacrydium cupressinum ), River Birch ( Betula nigra ), River Red Gum ( Eucalyptus camaldulensis ), Rock Elm ( Ulmus thomasii ), Rocky Mountain Douglas-fir ( Pseudotsuga menziesii ), Rose Chestnut ( Mesua ferrea ), Sal ( Shorea robusta ), Sapele ( Entandrophragma cylindricum ), Sassafras ( Sassafras albidum ), Satinwood ( Chloroxylon swietenia ), Scots Pine ( Pinus sylvestris ), Shagbark Hickory ( Carya ovata ), Shellbark Hickory ( Carya laciniosa ), Sheoak ( Allocasuarina casuarinaceae ), Shortleaf Pine ( Pinus echinata ), Silver Birch ( Betula pendula ), Silver Fir ( Abies alba ), Silver Maple ( Acer saccharinum ), Silver Wattle ( Acacia dealbata ), Sitka Spruce ( Picea sitchensis ), Sonokeling ( Dalbergia latifolia ), Sourwood ( Oxydendrum arboreum ), Southern Blue Gum ( Eucalyptus globulus ), Southern Live Oak ( Quercus virginiana ), Southern Mahogany ( Eucalyptus botryoides ), Southern Red Oak ( Quercus falcata ), Southern Sassafras ( Atherosperma moschatum ), Southern Whitecedar ( Chamaecyparis thyoides ), Spanish-cedar ( Cedrela odorata ), Sugar Pine ( Pinus lambertiana ), Sugi ( Cryptomeria japonica ), Swamp Chestnut Oak ( Quercus michauxii ), Swamp Cottonwood ( Populus heterophylla ), Swamp Mahogany ( Eucalyptus robusta ), Swamp White Oak ( Quercus bicolor ), Sweet Birch ( Betula lenta ), Sycamore Maple ( Acer pseudoplatanus ), Tallowwood ( Eucalyptus microcorys ), Tamarack Larch ( Larix laricina ), Tambotie ( Spirostachys africana ), Tasmanian Oak ( Eucalyptus regnans ), Teak ( Tectona grandis ), Tupelo Gum ( Nyssa aquatica ), Turkish Walnut a/k/a English Walnut ( Juglans regia ), Turpentine ( Syncarpia glomulifera ), Wandoo ( Eucalyptus wandoo ), Water Oak ( Quercus nigra ), Weeping Willow ( Salix babylonica ), Wenge ( Millettia laurentii ), West Indies Mahogany ( Swietenia mahagoni ), Western Hemlock ( Tsuga heterophylla ), Western Larch ( Larix occidentalis ), Western Redcedar ( Thuja plicata ), Western White Pine ( Pinus monticola ), White Ash ( Fraxinus americana ), White Basswood ( Tilia heterophylla ), White Birch ( Betula pubescens ), White Mahogany ( Eucalyptus acmenoides ), White Oak ( Quercus alba ), White Spruce ( Picea glauca ), White Willow ( Salix alba ), Wild Cherry ( Prunus avium ), Willow Oak ( Quercus phellos ), Wych Elm ( Ulmus glabra ), Yellow Birch ( Betula alleghaniensis ), Yellow Birch ( Betula lutea ), Yellow Buckeye ( Aesculus flava ), Yellow Lapacho ( Tabebuia serratifolia ), Yellow Poplar ( Liriodendron tulipifera ), and York Gum ( Eucalyptus loxophleba ). Other species of tree may also be used.
[0039] Step B. dry said piece of wood until said piece of wood has a moisture content of less than fifteen percent.
[0040] Step C. place said piece of wood into an oven heated to between 150° C. and 240° C.
[0041] Step D. allow said piece of wood to be heated by oven for between 2 and 96 hours such that said piece of wood achieves a temperature of at least 150° C.
[0042] Step E. remove said piece of wood from oven and allow said piece of wood to cool to substantially room temperature.
[0043] The foregoing Steps A through E are to be performed consecutively.
[0044] The wooden item to be manufactured from the wood treated by the method of the present invention may be one or more of the following: acoustic guitar fingerboard, electric guitar fingerboard, steel guitar fingerboard, guitar tuning peg, guitar bridge, guitar tail piece, banjo fingerboard, banjo tuning peg, banjo bridge, violin fingerboard 10 , violin tuning peg 20 , violin bridge 30 , violin tail piece 40 , violin chin rest 50 , viola fingerboard, viola tuning peg, viola bridge, viola tail piece, viola chin rest, cello fingerboard, cello tuning peg, cello bridge, cello tail piece, double bass fingerboard, double bass tuning peg, double bass bridge, double bass tail piece, mandolin fingerboard, mandolin tuning peg, mandolin bridge, mandolin tail piece, piano key 60 , organ key, clarinet body 90 , oboe body, gunstock 110 , knife handle 80 , pool cue 100 , toy game piece, chess piece 70 , baseball bat, bed frame, bench, bookcase, bowl, box, bureau, cabinet, chair, chest, clock casing, coat rack, desk, door, flooring, furniture, musical instrument, nightstand, oar, paddle, rack, religious statuary, serving ware, sporting equipment, table, tool handle, wooden toy, kitchen utensil, window frame, window sill, wood carving, or wooden bathtub. Other wooden items requiring hardness may also be manufactured from wood treated by the method of the present invention.
[0045] Referring to Step B, the piece of wood is dried until it has a moisture content of less than fifteen percent (15%). The drying can be performed by any means known in the art, including air drying, kiln drying, or other means. While the moisture content can be any amount less than fifteen percent (15%), the dryer the wood the better, with a moisture content of ten percent (10%) or even five percent (5%) being desirable.
[0046] Referring to Step C, the dried piece of wood is placed into an oven heated to between 150° C. and 240° C. The oven may be any type of oven known in the art which can attain the appropriate temperatures and maintain substantially constant temperatures over time. The oven may be preheated to the desired temperature before the wood is placed therein, or it may be preheated to a preliminary, lower temperature before the wood is placed therein and thereafter heated to the desired temperature, or it may not be preheated at all, with the wood being placed in a cold oven and then the oven temperature raised to the desired temperature. In the preferred embodiment, the oven will be preheated to an intermediate temperature, preferably in excess of 100° C. The wood will be placed into the oven and then the oven temperature will be gradually raised to the desired temperature, at a substantially constant rate of increase. The preferred temperature is between 160° C. and 190° C.
[0047] Referring to Step D, the piece of wood remains in the oven to be heated at the desired temperature for between 2 and 96 hours such that the piece of wood achieves an internal temperature of at least 150° C. In the preferred embodiment the wood is heated for 36 to 72 hours, depending on the amount of wood in the oven and the species. The oven will be maintained at substantially the preferred temperature for the duration of Step D.
[0048] In one embodiment of the method, an additional Step D′ is performed, concurrently with Step D. In Step D′, while the piece of wood is being heated in the oven in Step D, a treatment is applied to the wood. The treatment may be any substance which enhances the structural changes occurring to the wood during heating. In the preferred embodiment the treatment is a coolant. The application of a coolant to the wood protects the surface of the wood from scorching. Because the outer surface of the wood becomes heated before the inner core of the wood, the prolonged exposure to heat necessary to heat the inner core of the wood could raise the outer surface to excessive temperatures, potentially resulting in surface damage. The coolant attenuates the surface temperature of the wood to prevent excessive heating thereof. Any form of liquid or gaseous coolant may be used. In one embodiment the preferred coolant is water. Water may be applied in liquid form to the wood during Step D. In the preferred embodiment water is applied to the wood in the form of steam. In other embodiments chemical treatments can be applied to the wood to protect the surface. The treatment may be applied continuously, or in the preferred embodiment it may be applied periodically to the wood. The timing of the application of treatment to the wood may be computer controlled to achieve the desired surface temperature of the wood for maximum protection during heating.
[0049] Referring to Step E, after the wood has been heated for the desired length of time it is removed from the oven and allowed to cool. In one embodiment the wood is simply removed from the oven without first lowering the oven temperature. In another embodiment the oven temperature is lowered prior to the removal of the wood. In this embodiment the oven temperature will be gradually lowered to an intermediate temperature, preferably in excess of 100° C., with the lowering of the oven temperature occurring at a substantially constant rate. In the most preferred embodiment the rate of decrease in temperature will be substantially the same as the rate of increase in temperature at the beginning of Step D. Once the intermediate temperature is reached the wood is removed from the oven. In all embodiments, once the wood is removed from the oven it is allowed to cool to substantially room temperature. This cooling process may be accelerated by moving cool air over the wood by the use of fans, or by placing the wood into a cooled space, such as a refrigeration unit. Alternatively, the wood may be allowed to cool simply by leaving it out in a storage area.
[0050] In preferred embodiments of the method of the present invention, an optional Step F is performed, whereby once the wood has suitably cooled it is cut into a finished wooden item. The wood may be cut in Step F by any practical means known in the art, including with hand tools, power tools, computer-controlled cutting devices, and the like. In the most preferred embodiments, finished wooden items are created by use of a computerized finishing machine.
[0051] An alternate method includes the optional step of, after selecting the appropriate piece of wood, creating a rough wooden item from the selected piece of wood before drying begins. The rough wooden item is then dried, heated, and cooled as before, and then optionally manufactured into a finished wooden item, as described above.
[0052] Yet another alternate method includes the initial step of obtaining a rough wooden item created from a piece of wood. The wood may be chosen from the same group of species of tree identified above. Other species of tree may also be used. The rough wooden item is then dried, heated, and cooled as before, and then optionally manufactured into a finished wooden item, as described above.
[0053] Modifications and variations can be made to the disclosed embodiments of the method without departing from the subject or spirit of the method as defined in the following claims.
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An improved method for the treatment of wood in preparation for manufacture of wooden items comprising the steps of first heat treating the wood and then fashioning the wood into a finished item, whereby the resulting wooden item is darker, harder, more weather and rot resistant, and more stable than items fashioned from untreated wood.
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BACKGROUND OF THE INVENTION
The present invention relates to a sewing machine of the double chain stitch type and more particularly pertains to the lower stitching instrumentalities thereof for forming such a stitch.
Sewing machines of this type, that are well known generally include at least one needle and cooperating looper with each having an independent thread source for the formation of seaming stitches. Such machines also include separate actuating mechanisms for the needle and looper. The one for the needle provides a means for moving the needle alternately in two senses along a rectinlinear path which is substantially vertical and perpendicular to the direction of the seam. The actuating mechanism for the looper provides a means for moving said looper along a substantially elliptical pathway which is arranged horizontally perpendicular with respect to both the axis of sewing and the pathway through which the needle travels. Additionally such machines also include conventional feeding means for advancing a workpiece through the sewing zone where the needle and looper elements perform their intended function. In known sewing machines of the type described above, the actuating means for the looper consists of two separate and similar mechanisms.
One of these mechanisms serves to provide the looper with an alternating to and fro movement which is perpendicular to the sewing axis and which substantially intersects the pathway through which the needle travels.
The other mechanism serves to provide the looper with an alternating to and fro movement which is parallel to the sewing axis and the combination of both movements causes the looper to travel in an elliptical pathway so that it will first grasp a loop of thread carried by the needle and then subsequently form a so-called "triangle of threads" into which the needle decends to effect the drawing of the looper thread through the loop of needle thread.
This mode of operation of the looper is well known to those conversant in the art and is effective in forming a double chain stitch of the type which is identified by numeral 401 in the United States Federal Standard Catalog. To form a stitch of the above described type with known devices of the prior art it is necessary that the looper also be caused to move in a direction parallel to the direction of the sewing axis in order to effect the formation of a triangle of threads which is formed by the looper itself, which forms its base, by the thread carried by the looper which is stretched between the ends thereof and the last stitch formed of the seam, as well as by the loop of thread taken from the needle that extends between the last stitch and the blade of the looper.
The latter two elements of thread form the sides of the triangle of threads with the vertex thereof being united with the workpiece so that the triangle lies extended in the direction in which said workpiece is caused to advance during the sewing cycle.
Displacement of the looper parallel to the direction of the sewing axis is provided in order to allow the looper to grasp the loop of needle thread as the needle is moving upwardly and, as is know, is located on that side of said needle at which the seam is being displaced. When the needle is raised the looper moves to a position which when said needle decends will be on the opposite side thereof and facilitates penetration of said needle into the triangle of threads during its downward travel.
SUMMARY OF THE INVENTION
An object of the present invention is that of simplifying sewing machines of the type described above, by eliminating that mechanism for effecting movement of the looper in a direction parallel with the sewing axis and to provide a new phasing between the needle and the looper which provides correct linking of the threads so as to form a seam of stitches of the double chain type.
To accomplish these objects the present invention provides a single mechanism for alternately displacing the looper in two senses along a retilinear pathway which is disposed, relative to the pathway of the needle, on that side of the latter opposite the side at which the triangle of threads is formed. The arrangement of each of these pathways is such that the needle is always located on the same side relative to the looper both during the stage of seizing of the loop of needle thread as well as during the stage of said needle's penetration into the triangle of threads.
The main advantage of using the new reciprocal arrangement of these pathways is that of eliminating the need of a compound movement of the looper in an elliptical pathway because the formation of the stitch can now be accomplished by causing the looper to travel solely in a rectilinear pathway.
Additionally the new reciprocal arrangement of these pathways does not restrict the side from which the movement of the looper towards the needle initiates, i.e. it can be from right to left or vice versa with respect to the direction of sewing since the choice of the side now depends exclusively on whether it is desired or not to employ a conventional production looper which is available for use in sewing machines of the known type.
According to the preferred embodiment utilized to show and describe the present invention, it will be noted that the hook starts its movement towards the needle from the left relative to the direction of stitching.
This choice requires the provision of a longer path for the thread which is carried by the looper, but by using a conventional type looper largely compensates for the slight disadvantage of the longer thread.
These and other objects of the present invention will become more fully apparent by reference to the appended claims and as the following detailed description proceeds in reference to the figures of drawing wherein:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a portion of a sewing machine showing the device according to the invention applied thereto;
FIG. 2 is a schematic view showing the rectilinear pathway of the looper and its relationship to the needle;
FIGS. 3 and 4 are similar views showing schematically and in perspective two opposite phases of cooperation between the looper and needle during the formation of a stitch; and
FIG. 5 is a perspective view of the looper showing the thread channel formed therein.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Now referring to the drawings enough of a sewing machine is shown in FIGS. 1, 3 and 4 to serve as a basis for a detailed description of the invention applied thereto. In FIG. 1 the sewing area is shown and among the various parts of the machine there is shown a needle 1 and a pressure foot 2 that includes the usual opening 3 through which said needle is caused to extend during the performance of its intended function. A needle plate 4 is located beneath the pressure foot and is provided with an opening 5 which also serves to permit passage of the needle 1. The needle plate is also provided with the usual series of openings identified by numeral 6 which in a known manner permit conventional feed dogs (not shown) to perform their function of advancing a workpiece (also not shown) along the sewing axis or that direction depicted by the indicating arrow A. Below the needle plate 4 the sewing machine is provided with a looper 7 mounted on a support 8 in such a way so as to be orientated perpendicular to the sewing axis and perpendicular to the vertical pathway 9 along which the needle 1 is caused to travel. This vertical pathway 9 extends through the two openings 3 and 5 provided in the presser foot and needle plate and intersects the sewing axis.
The support 8 is pivotably supported at its lower end by means of a pin 10 which assembles in a stationary part 11 of the sewing machine. This support 8 also includes a pivot pin 12 intermediate its ends which extends outwardly therefrom in a plane parallel with the sewing axis and is adapted to pivotably support one end of a driving rod 13 thereon. The opposite end of the driving rod 13 is operatively connected to a drive mechanism for the looper 7 and is identified generally by numeral 14.
This drive mechanism 14 includes a control eccentric 15 mounted on and for rotation with the main shaft 16 of the sewing machine. One end of a connecting rod 17 is assembled on the control eccentric 15 and its opposite end defines a universal ball joint 17' operatively connected to one end of an arm 18. The opposite end of this arm 18 is fixedly attached to a cross shaft 19 (FIG. 1) and through the connecting rod 17 the rotary movement of the main shaft 16 causes oscillating movement of said cross shaft.
The cross shaft 19 also includes an arm 20 fixed thereto which extends generally downward and with the lower end thereof being pivotally connected, by means of a pin 21, to that end of the driving rod 13 opposite its connection to the support 8. Through arm 20 the oscillating movement of cross shaft 19 causes reciprocating movement of the driving rod 13 and pivotable movement of the support 8 to effect to and fro travel of the looper 7 in a rectilinear pathway 22.
During operation the needle 1 is caused to be alternately displaced in two senses along a vertical pathway 9 by a conventional drive means not shown, but which is operatively connected with the drive mechanism 14 for effecting actuation of the looper 7. The looper 7 is also alternately displaced in two senses along the rectilinear pathway 22 (FIG. 2) which extends generally perpendicular to the needle pathway 9 that is represented by a+sign in this figure of drawing.
The leading end or tip of the looper is identified by numeral 23 and the stitching cycle commences with said looper moving from left to right, as viewed in FIG. 3, so that it passes in close proximity with the needle 1. During this initial movement the tip 23 enters the loop of needle thread depicted by numeral 27 as the needle is moving upwardly in its pathway 9. During these movements of the looper and needle, the previously formed stitch is displaced in the direction of the indicating arrow A which applies tension to both the needle and looper threads so that as the looper reverses its direction of travel, the needle will decend into a triangle of threads 24 (FIG. 4) formed by the loop of needle thread taken by said looper during its initial movement and the looper thread itself depicted by numeral 28.
The formation of the triangle of threads 24 mentioned above is an essential part of the stitching cycle in sewing machines utilized for form stitches of the double chain type. The base of this triangle of threads is formed by a blade 25 which is that portion of the looper that extends from its tip 23 to its rear supporting structure identified by numeral 26. One side of the triangle is formed, as shown in FIG. 4, by the loop of needle thread 27 and the other side by the looper thread 28. The sides of this triangle form a vertex that is united with the previously formed stitch 29 so that said triangle is caused to extend in the direction of the indicating arrow A. To employ a single looper drive mechanism according to the invention it was necessary that the threading of the needle 1 be inverted relative to the direction of sewing, i.e. the needle thread 30 is threaded through the eye 31 of the needle from that side opposite to the side at which the looper travels in its rectilinear pathway 22. By threading the needle in this manner that portion of the needle thread identified by numeral 30a is located on the looper side of the needle which facilitates the formation of the loop 27 to be taken by the tip 23 of the looper 7.
As a result of the relative positions which are established for the needle and looper, the latter travels along its rectilinear path both in a forwardly direction toward the needle as well as in a reverse direction away from said needle, and the latter during its travel is effective in penetrating the triangle of threads on each of its downward strokes.
The mode of operation of the looper is considered to be unique for to form double chain stitches prior to the instant invention it was necessary that the looper be caused to travel in an elliptical pathway which required that it be shifted from one side of the needle to the other. Although the present invention teaches travel of the looper solely in a rectilinear pathway, it is effective in linking the threads to form double chain stitches in a manner which corresponds to the known method of forming this type of stitch.
The sole variation with respect to the known form of stitch occurs in the vertical branches 30b of the needle thread 30 that are located within the workpiece and which are rotated by a half back turn due to the effect of the tension produced by the branch 28a of the looper thread 28 during the closing of a stitch which increases friction in the passage within the workpiece causing the stitch to be held to a greater extent.
For the purpose of assuring the correct location of the loop 27 of the needle thread 30 so that it will be taken by the looper at the front of needle 1, said needle is provided with two symmetrically helical grooves 32 which extend upwardly from the eye 31 on opposed sides of the needle and terminate in such a way that the portions of needle thread 30 contained therein are unable to interfere one with the other. The looper 7 was modified by providing it with a channel 33 through which the looper thread extends and is formed along the length of the underside of the blade 25 thereof. This channel 33 serves to prevent accidental needle interference with the looper thread as said needle is caused to move downwardly in its pathway to enter the triangle of threads. This channel 33 does not change the operating characteristics of the looper 7 so that it can be utilized in other sewing machines not having the looper actuating device of the present invention.
Although the operating position of the looper has been shown and described with its tip portion 23 pointed to the right as viewed in the various figures of drawings, it should be understood and obvious to those skilled in the art that the looper could perform the intended function of the invention if its tip portion 23 were arranged to face in the opposite direction. The direction in which the tip of the looper faces can actually be considered a matter of choice because the control eccentric 15 carried on the main shaft 16 must be rotated exactly 180° so as to maintain the necessary phasing between the needle and said looper for the correct formation of stitches.
Although the present invention has been described in connection with a preferred embodiment, it is to be understood that modifications and variations may be resorted to without departing from the spirit and scope of the invention as those skilled in the art will readily understand. Such modifications and variations are considered to be within the purview and scope of the invention and the appended claims.
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A device for forming double chain stitches in a sewing machine having independent thread sources for its needle and looper. The device includes a driving apparatus for causing travel of the looper solely in a rectilinear pathway in front of the needle and is effective in taking a loop of thread from the needle and to form a triangle of threads into which the needle will descend to effect completion of a stitch as the looper returns to its starting position.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention pertains to the field of hinged orthopedic splints and braces of the type applied across the joint of a limb such as a knee or elbow for limiting movement of the joint for therapeutic purposes, and is more particularly directed to certain improvements in the hinge for such splints.
2. Background of the Invention
Knee and elbow splints or braces typically have an upper plate and a lower plate connected to each other by a hinge such that, when the upper plate is attached to the limb above the joint and the lower plate to the limb below the joint, the patient may flex the limb at the joint. Many such splints are known and are commonly used in the course of orthopedic rehabilitation. It is also known to provide splints with adjustable hinges which enable a therapist to set limits to the arc of movement of the splint and hence of the patient's joint, as may be required by the patient's condition and the course of therapy. One general class of knee brace in current use has a detent movable on an upper plate into and out of engagement with a toothed or serrated edge on a lower plate. Within this class of splints there are two types. In the first type the toothed edge may be fixed on one plate so as to lock the two plates in a selectable relative angular relationship, i.e., the two plates are fixed at a desired angle selected from a range of possible angular relationships. Once so fixed the two plates are not movable and the patient cannot flex the joint while wearing the splint. In the second type of splint within this class one or more toothed edges are adjustable on one plate enabling a variable range of movement to be set for the hinge. For example, two toothed elements are movable on the upper plate, such as two rotatable disks each with a toothed edge and a stop engageable by the lower plate. Angular movement of the lower plate relative to the upper plate is confined to an angular range defined by the relative positioning of the two stops, which in turn are adjustably set by rotation of the disks to the desired positions, and are fixed in that position by a common detent movable on the upper plate. In both types of splints the relative angular positioning of the two is set or limited by a detent movable on one plate and adjustably engagable with some structure mounted on the other plate.
A continuing problem encountered in this class of splints is to provide for convenient adjustment of the splint's angular settings by a therapist while also making the splint's settings relatively resistant to tampering by the patient who may become impatient with the course of therapy and wish to reset the splint to suit his or her immediate comfort.
A second shortcoming encountered in currently available knee or elbow braces of the aforementioned class is that the hinge settings are right or left handed, thereby limiting a particular splint to application on a limb of corresponding handedness. A continuing need exists for adjustable splints having ambidextrous hinge settings so that a given splint may be used interchangeably on either a right hand or left hand limb.
BRIEF SUMMARY OF THE INVENTION
The present invention addresses the aforementioned shortcomings by providing certain improvements in adjustable knee braces. These improvements include a tamper resistant hinge detent configured to discourage tampering by the patient with the hinge settings, a detent lockable in either a retracted or an engaged position to facilitate range setting by a therapist when locked in a disengaged condition of the detent and before securing the detent when locked in its engaged position, and a bidirectional hinge to allow use of the splint on either left or right limbs.
In general, the improvements of this invention concern the class of orthopedic splints having an upper plate and a lower plate connected for pivotal movement, and a detent element supported on the upper plate and displaceable into and out of an engaged condition with a structure on the lower plate thereby to fix or limit relative angular movement between the two plates. The detent is spring biased towards its engaged condition and must be retracted out of engagement against the spring bias by manual effort applied by a therapist.
In a first form the invention the toothed edge may be fixed to the lower plate in which case the splint is fixed at a selected angular relationship of the upper and lower plates. In a second form of the invention, two movable toothed edges are supported on the upper plate, such as on two wheels independently rotatable on the upper plate. Both wheels are locked against rotation relative to the upper plate by engagement with the detent, and the lower plate is free to pivot between two stops, one stop located on each wheel. The angular range of the plates is set by adjusting the angular spacing between the stops by rotation of the wheels while the detent is disengaged.
In one improvement according to the present invention the splint has a cover assembly for protecting the detent element against displacement out of engagement by an unaided hand, and an aperture in the cover sized and disposed for admitting a pointed tool end into engagement with the detent for displacing the detent out of its engaged condition, so that tampering with the angular setting of the hinge by a patient wearing said orthopedic splint is discouraged.
In a presently preferred embodiment of the invention, the detent is displaceable in a guide way defined between the upper plate and the cover assembly, and a biasing spring is contained in the guide way. The spring may be a coil spring compressed between the cover assembly and the detent. The cover assembly may include a spacer which is mounted between the upper plate and cover plate and defining the guide way for the detent, and a cover plate applied over the spacer for containing the detent in the guide way. The access aperture may be a slot in the cover plate, the slot being aligned with a direction of displacement of the detent. The detent preferably has a tool end receptacle such as a hole or depression adapted to receive the pointed tool and thereby to facilitate positive engagement and displacement of the detent by means of the tool end. The access aperture is preferably sized and shaped so as to allow visual confirmation of detent engagement with the toothed element.
Typically, the detent is engageable with an arcuate toothed edge supported on the lower plate, and the pivotal movement of the two plates of the splint comprises an arc including a zero angle position situated at an intermediate location along the arc, such that the plates may be moved through substantial angular ranges on either side of the zero angle position. The zero angle position may be centered along the arc such that the plates may be pivoted through equal angular ranges on either side of the zero angle position. The zero angle position may be situated along the arc such that the two plates are aligned in a straight line when the hinge is set to the zero angle position. By providing for a range of angular movement of the hinge to one side or the other of the zero position, the splint may be applied to a right side or a left side of a limb, eliminating the need for special left handed or right handed splints. In another aspect of the invention the hinge has a locking element removably engageable for holding the detent out of its engaged condition to thereby facilitate application of the splint to a patient's limb with the hinge free to rotate through its full 240 degree arc of movement, so that the therapist can bend the splint quickly and easily to match the position of the patient's limb. That is, the splint angle can be easily adjusted to the angle of the patient's joint rather than having to reposition the patient's limb to fit the angle of the splint. Once the splint is applied and fastened to the limb, the detent locking element facilitates setting of the hinge angular range by holding the detent out of engagement while the range setting elements or wheels are properly positioned, after which the detent may be released into engagement with the range setting elements.
The locking element may be in threaded engagement with the detent, such as a screw engageable in a threaded screw hole defined in the detent, such that an end of the screw bears against the upper plate in a tightened condition of the screw, or is advanced into a hole in the upper plate, thereby to hold the detent against the spring bias in a disengaged condition.
The structure engaged by the detent to fix or limit relative angular movement between the two plates may be a toothed edge fixed on the lower plate, such that the two plates are fixed in a selected angular relationship in an engaged condition of the detent. Alternatively, the structure engaged by the detent may be a range setting assembly adjustable for limiting pivotal movement between the two plates to a greater or lesser arc in an engaged condition of the detent. The range setting assembly may comprise a pair of wheels turning concentrically with the pivotal movement of the plates, each of the wheels having a wheel edge engageable by said detent for locking the wheel relative to the upper plate, and a stop on each of the wheels operative for limiting pivotal movement of the lower plate relative to the upper plate, and a pin or equivalent stop element on the lower plate being disposed between the two stops on the wheels such that the range of relative pivotal movement of the plates may be set by the angular spacing between the two stops when the detent is engaged for locking the wheels against rotation relative to the upper plate.
These and other improvements, features and advantages of this invention will be better understood by turning to the following description of the preferred embodiments taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan view of a knee brace according to this invention applied to the outside of a knee joint of a patient's leg;
FIG. 2 is an enlarged top plan view of an ambidextrous hinge according to this invention, with the upper and lower plates of the splint shown in straight line zero angle alignment;
FIG. 3 is a cross-sectional view of the hinge taken along line 3 — 3 in FIG. 2 ;
FIG. 4 is a view taken along lines 4 — 4 in FIG. 3 showing the interior of the hinge with the detent in engaged condition with the toothed edge of the lower plate, thereby locking the upper and lower plates against relative movement;
FIG. 5 is a view as in FIG. 4 showing the detent retracted against the bias spring to a disengaged position and depicting the angular range of movement of the lower plate between a solid lined position and a phantom lined position.
FIG. 6 shows a second type of ambidextrous hinge for limiting the pivotal movement between the upper plate and the lower plate of the splint to an adjustable angular range, the hinge being shown with the cover plate removed to expose the detent in engaged condition to limit the range of movement between solid and phantom lined positions of the lower plate on one side of a zero position of the hinge as indicated by angle A in the figure.
FIG. 7 shows the ambidextrous hinge of FIG. 6 set to a different angular range depicted by solid lined and phantom lined positions of the lower plate on the opposite side of the zero position of the hinge as indicated by angle B in the figure;
FIG. 8 is a cross-sectional view showing the detent in engagement with the rotatable toothed wheels of the range setting assembly of the hinge and the detent locking screw threaded into the detent but disengaged from the upper plate; and
FIG. 9 is a view as in FIG. 8 but showing the detent in a retracted position compressing the biasing spring, and the detent locking screw passing through a hole in the upper plate and inserted into a hole in the lower plate to lock the detent in a retracted condition against the bias of the compressed spring.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to the drawings wherein like elements are designated by like numerals, FIG. 1 depicts an orthopedic splint or knee brace 10 applied to the knee joint K of a patient. The brace includes an upper plate 12 and a lower plate 14 connected to each other for pivotal movement by a hinge 16 . The upper plate is attached to the thigh of the patient's leg by an upper strap S 1 and the lower plate is similarly attached to the leg below the knee by a lower strap S 2 so that the hinge 16 lies adjacent to and pivots with bending of the knee. Typically, two similar knee braces 10 are applied to the knee joint of the patient, one brace on the outside of the leg, as shown in FIG. 1 , and an opposite second brace (hidden in FIG. 1 ) on the inside of the leg. The two braces are generally parallel to each other and provide lateral support to the knee joint while allowing flexing of the knee joint in a plane parallel to the planes of movement of the brace hinge 16 . In the course of rehabilitation or other therapy it may be desirable to temporarily hold the knee at a particular fixed angle or to limit the range of movement of the knee to a given angular range. For this purpose the hinge of this invention is provided with an adjustable detent mechanism which will be described below.
FIGS. 2 through 5 illustrate a splint 10 of the first type with a hinge 16 which has a single toothed element fixed relative to one of the plates and engageable by the detent to fix the hinge and hence the plates 12 , 14 at a selected angle within a range of angular movement of the hinge, and thereby immobilize the patient's leg at the selected angle. FIGS. 6 through 9 illustrate a hinge 16 ′ for splints of the second type where the hinge has two toothed elements, both of which are movable relative to either the upper or lower plate, and are both immobilized relative to one of the plates by engagement with the detent so that the hinge can be set either at a fixed angle between the two plates or to allow relative pivotal movement of the upper and lower plates over an arbitrary, adjustable angular range, so that the patient's leg wearing a splint equipped with hinge 16 ′ may bend at the knee but over a range limited by a setting of hinge 16 ′ chosen by the therapist. While not shown in the drawings, hinge 16 ′ is part of a splint 10 ′ which is similar to splint 10 in FIG. 1 except that hinge 16 ′ is substituted for hinge 16 .
FIGS. 2 and 3 depict in greater detail the hinge 16 . As best seen in FIG. 3 the upper plate 12 carries a cover assembly which includes a cover plate 20 and a spacer 18 . The lower plate is pivotably connected to the upper plate by means of a pivot rivet or screw 22 which secures the cover plate 20 and the upper plate 12 to opposite sides of a pivot sleeve 24 . The lower plate turns about the pivot sleeve 24 and is held between first and second pairs of washers 26 which reduce friction and facilitate relative pivotal movement between the upper and lower plates. The cover plate 20 is fixed to the upper plate by a rivet 26 a which also passes through the spacer 18 . The spacer 18 is further fastened to the upper plate by two additional rivets 26 b , 26 c , seen in FIG. 2 , which pass through the cover plate, spacer and upper plate in a manner similar to rivet 26 a.
A detent 30 is captive in a guide way 28 defined in the spacer 18 as best seen in FIGS. 4 and 5 . A bias spring 32 is compressed between the end 34 of the detent and the closed end 36 of the guide way 28 . The cover plate 20 , shown in FIG. 2 but removed in FIGS. 4 and 5 for clarity of illustration, holds both the detent and the bias spring in the guide way 28 . The bias spring continuously urges the detent towards engagement with a circularly curved toothed edge 40 at the end of the lower plate 14 . The detent has a pointed end 38 which fits between any adjacent pair of teeth 42 of the toothed edge 40 , thereby interlocking the upper and lower plates 12 , 14 against relative pivotal movement about the pivot sleeve 24 and pivot rivet or screw 22 . In this condition the upper and lower plates of the brace are fixed at a particular angle to each other, and the knee of a patient wearing the brace is similarly fixed at this angle.
The toothed edge 40 extends along a circular arc of about 240 degrees centered on a straight line which passes through the pivot center of the hinge and also through the pointed end 38 of the detent. When the detent is engaged with the center of the toothed edge 40 as in FIG. 4 the upper plate 12 and the lower plate 14 are aligned in a straight line with each other. By retracting the detent to the disengaged condition of FIG. 5 the lower plate may be rotated 120 degrees left or 120 degrees right of the center or zero angle position of FIG. 4 , as depicted by the solid lined and phantom lined positions, respectively, of the lower plate 14 in FIG. 5 . Returning to FIG. 2 , the top side of the cover plate 20 has a circularly curved edge 48 which is parallel to and overlies the toothed edge 40 of the lower plate. The edge 48 has a scale graduated in degrees of arc with a zero position at its center and graduations extending 120 degrees to each side of the zero position. A pointer 49 on the lower plate provides a reference for positioning the lower plate at a selected angle relative to the upper plate of the brace.
The brace of FIGS. 2 through 5 is ambidextrous, i.e., it may be used interchangeably on either a left or a right hand limb of a patient without modification or adjustment to the hinge mechanism. This is because a knee joint naturally flexes from a straight or zero angle position through an arc of some 120 degrees to a fully bent condition of the leg. The hinge of this invention provides for arcs of angular movement of 120 degrees to either side of the zero position of the hinge. Consequently, the brace 10 with hinge 16 can be applied interchangeably to either the inside or outside of a leg, and to either a left leg or a right leg of a patient. The hinge 16 will naturally rotate along the angular range on the appropriate side of the zero position of the hinge 16 according to the direction of motion of the knee joint to which it is applied, without need for attention on the part of the therapist. As a result, substantial savings may be realized in the manufacture of splints and also in the time and level of skill is required by therapies involving such splints.
Retraction of the detent 30 is accomplished by manually pushing or sliding the detent within the guide way 28 against the force of bias spring 32 , compressing the bias spring as shown in FIG. 5 until the pointed end 38 of the detent is withdrawn from between the teeth 42 of the toothed edge, thereby freeing the lower plate 14 for rotation relative to the upper plate 12 about the pivot sleeve 24 .
An access aperture in the form of slot 44 is cut in the cover plate 20 over the guide way 28 and oriented in the direction of movement of the detent 30 . The slot 44 admits a narrow or pointed tool end to be introduced into contact and engagement with the detent 30 , for the purpose of displacing the detent away from its engaged condition when adjustment of the brace angle setting is required. The slot 44 is shaped and sized, for example sufficiently elongated to expose the end of the detent in its engaged position and thus permit visual confirmation that the pointed end of the detent is satisfactorily engaged between the teeth of the toothed edge, as seen in FIG. 2 . A receptacle in the form of a depression or hole 46 in detent 30 is aligned with access slot 44 , as shown in FIG. 2 . The receptacle 46 receives the narrow end of the tool and facilitates positive engagement between the tool and the detent while displacing the detent out of engagement and against the force of the bias spring 32 . The access slot 44 effectively prevents access to the detent by an unaided hand, i.e. a hand unaided by a sufficiently narrow ended tool capable of passing through the slot 44 into the guide way 28 . The detent is therefore recessed out of easy reach under the cover plate 20 and is protected against displacement away from its engaged condition by a patient's unaided hand, thereby discouraging tampering with the angular setting of the hinge 16 by a patient wearing the splint 10 . The width of slot 44 is not critical, so long as it is sufficiently narrow to keep a finger from contacting and moving the detent 30 . A slot width of 3/16 ths of an inch has been found satisfactory, and admits, for example, the pointed end T of a ball point pen or pencil, as shown in FIG. 3 , or any other readily available implement which may be pressed into service by a therapist as a tool for adjusting the hinge angle setting of brace 10 . Of course, in cases where tampering by the patient is not a concern, a post, pin, finger tab or equivalent structure extending above the cover plate 20 through slot 44 may be fitted in the receptacle 46 to provide a permanent or removable exteriorly accessible means for more conveniently moving the detent 30 out of engagement, such as screw 70 in FIG. 8 . The screw 70 can be used by the therapist as a finger hold for pushing and disengaging the detent during splint installation. The screw 70 may then remain in place for subsequent detent engagement or disengagement, or it may be removed completely from the splint at the option of the therapist.
Turning now to FIGS. 6 through 9 , hinge 16 ′ has a detent 30 and detent cover assembly 20 , 18 similar to those described above in connection with hinge 16 of FIGS. 2–5 . The hinge 16 ′ differs from hinge 16 in that the fixed toothed edge 40 of hinge 16 is replaced by a range adjustment assembly which includes two toothed wheels 50 a , 50 b , both rotatable on pivot sleeve 24 and thus concentrically with pivotal movement of the hinge. Each toothed wheel 50 a,b has a circular toothed edge 52 a , 52 b extending about 240 degrees of arc about the respective wheel. An adjustment tab 54 a , 54 b extends radially from an untoothed portion of each wheel. Each wheel also has an arcuate slot 56 a , 56 b extending approximately 120 degrees of arc from an inside end 58 situated on a diameter line bisecting the toothed edge 52 a,b , to an outside end 62 . This diameter line also bisects the tab 54 a , 54 b of the wheel. The arcuate slots on the two wheels extend in opposite directions from their inside end 58 . In a centered condition of the two wheels 50 a , 50 b the detent 30 is aligned with the center of the toothed edge 52 a , 52 b , as shown for wheel 50 a in FIG. 6 , so that the toothed edge of the wheel extends 120 degrees to either side of this center or zero position. It should be noted that the adjustment tab 54 a is diametrically opposite to the center of the toothed edge 52 a and in the centered condition of the wheel 50 a the tab is also aligned with the lower plate 14 of the brace 10 ′. The toothed edge 52 b is hidden directly under the toothed edge 52 a in FIGS. 6 and 7 but is similar to edge 52 a . The two wheels 50 a , 50 b are in fact interchangeable, and differ only in that one wheel is flipped over or turned upside down relative to the other on the pivot sleeve 24 . Directional pointers L and R or similar directional indicia are provided on the tabs 54 a , 54 b in FIGS. 6 and 7 to guide the therapist when adjusting the angular constraints of the hinge. The directional indicia point in opposite directions of rotation to provide quick and easy identification of the two tabs.
A stop pin 60 is fixed to the lower plate 14 along a center line of the plate and extends through both arcuate slots 56 a , 56 b . The angular extent of rotation of each wheel 50 a , 50 b is therefore limited by the angular extent of the corresponding slot 56 a or 56 b . The range of angular movement of the hinge 16 ′ is determined by the relative positions of both wheels 50 a , 50 b and the resulting degree of overlap of the two slots 56 a , 56 b . As seen in FIG. 8 the thickness of the detent 30 is sufficient to concurrently engage both toothed edges 52 a,b and thereby lock both wheels 50 a,b against rotation. The plates 12 , 14 can also be locked at an angled position relative to each other by first placing the two plates at the desired angle, then turning the wheels 50 a,b to superimpose the tabs 54 a,b on the centerline of the lower plate thereby capturing the stop pin 60 between the ends 58 of the slots, and engaging the detent 30 to lock the wheels in this position. The hinge 16 ′ may also be set for an arbitrary range of angular movement by positioning the two wheels such that the slots 56 a , 56 b overlap by the desired angular range between the slot ends 58 , rotating the two wheels so as to position the overlapping slots 56 a , 56 b in the desired position relative to the upper plate 12 so as to set the desired maximum and minimum angles of the lower plate relative to the upper plate, and locking both wheels in this position by engaging the pointed end 38 of the detent with the toothed edges of both wheels. The minimum and maximum angles of rotation of the hinge may be read off the graduated scale 25 on cover 20 as indicated by the positions of tabs 54 a , 54 b relative to the scale. Arrow-type markings are situated on each tab to indicate their relative positioning to help avoid confusion on the part of the therapist.
FIGS. 6 and 7 illustrate the ambidextrous capability of the hinge 16 ′. As explained in the preceding paragraph each toothed wheel 50 a,b has a center position with a 120 degree angular range of the toothed edge on either side of the center position. Consequently the hinge 16 ′ may be set for an arbitrary arc of movement of up to 120 degrees to either the left side or the right side of the center position. FIG. 6 depicts a setting of the wheels 50 a,b defining a right side arc of movement between the solid lined and phantom lined positions of the lower plate 14 indicated by arrow A. FIG. 7 shows the wheels 50 a,b set and locked for a left side arc of movement between the solid lined and phantom lined positions of the lower plate 14 indicated by arrow B. FIGS. 6 and 7 show how the stop pin 60 travels within the overlapping portions of the arcuate slots 56 a,b such that movement of the lower plate 14 is stopped at the opposite ends 58 of the overlapping arcuate slots. From the foregoing it will be understood that the splint 10 ′ with hinge 16 ′ is fully ambidextrous and may be applied interchangeably on the inside or outside of the leg, and on either the left or right leg of the patient, to the same extent as the hinge 16 discussed in connection with FIGS. 2–5 .
FIGS. 8 and 9 illustrate an optional feature of this invention, namely, a detent locking element in the form of screw 70 with a knurled knob 71 threaded into a through-hole 72 in detent 30 . The detent locking screw 70 can be advanced to bear against the upper plate 12 with sufficient force to make a friction lock and hold the detent 30 in a retracted or engaged position. Optionally, a hole 74 may be provided in the upper plate 12 so that the threaded hole 72 aligns with hole 74 when the detent is retracted to a disengaged condition, and the detent locking screw 70 can then be advanced into hole 74 to hold the detent in a retracted position, as depicted in FIG. 9 . Either way, the detent locking element 70 conveniently holds detent 30 away from engagement with the toothed wheels 50 a,b for easier application of the splint to a patient's limb, so that the is splint can be quickly and easily bent to the angle of the patient's joint during fitting, and also to facilitate adjustment and positioning of the toothed wheels 50 a,b , when setting the desired angular range of movement of the splint as described in the preceding paragraph.
Engagement of the detent locking screw 70 in hole 74 relieves the therapist from having to hold the detent against the urging of the bias spring 32 and frees both of his or her hands for the task of fitting the splint on the patient's limb with the detent retracted. This is desirable during installation of the splint so as to permit free movement of the hinge in order to match the angle of the splint plates to the position of the patient's joint being fitted with the splint. The angular adjustments of the hinge are more conveniently set after the splint is fitted to the patient's limb. The locking screw can also be subsequently used to secure the detent in engaged condition, if desired.
From the foregoing it will be appreciated that several advantages and improvements over previously known knee braces and splint have been disclosed. Although preferred embodiments have been described and illustrated for purposes of clarity and example it must be understood that many changes, modifications and substitutions will be apparent to those having only ordinary skill in this art without thereby departing from the scope of the invention as defined by the following claims.
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A hinge for an orthopedic splint has two plates hinged for pivotal movement relative to each other and a detent engageable for locking the plates at a selected angle to each other, and a spring urging the detent into engagement. The detent is protected in a recessed guideway against operation with the unaided hand to discourage tampering with the splint settings by the patient fitted with same, but is retractable with a pointed tool inserted in the recess or a removable screw threaded in the detent as a finger hold. The screw may also pass through the detent and if tightened against an underlying plate keeps the detent disengaged to facilitate adjustment of the splint. The hinge allows left and right hand angular settings of the splint to either side of a zero angle for ambidextrous use of the splint, and radial tabs with directional markings are provided as visual indicators of the angular setting of the splint hinge.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a national phase entry under 35 U.S.C. §371 of International Patent Application PCT/AU2011/001019, filed Aug. 12, 2011, designating the United States of America and published in English as International Patent Publication WO 2012/019230 A1 on Feb. 16, 2012, which claims the benefit under Article 8 of the Patent Cooperation Treaty and under 35 U.S.C. §119(e) to U.S. Provisional Patent Application Ser. No. 61/373,723, filed Aug. 13, 2010, the disclosure of each of which is hereby incorporated herein by this reference in its entirety.
TECHNICAL FIELD
This disclosure relates, generally, to an electrical lead and, more particularly, to a method of fabricating an electrical lead and to an electrical lead. The electrical lead is particularly suitable for use as a catheter sheath of a catheter assembly.
BACKGROUND
Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of common general knowledge in the field.
In the manufacture of cardiac catheters, a problem arises with an easy, simplified way to attach electrical conductors to electrodes arranged on a catheter sheath of the catheter. It will be appreciated that these conductors need to extend through the catheter sheath to a proximal end of the catheter sheath to be connected to an electrical connector for connection to diagnostic or therapeutic equipment or to a patient cable.
Generally, the manner of connecting the electrodes to the conductors and entraining the conductors within the catheter sheath is very labor intensive. This increases the cost of manufacture of the catheter sheath and, consequently, the cost of the final catheter.
SUMMARY
It is an object of the present invention to overcome or ameliorate at least one of the disadvantages of the prior art or to provide a useful alternative.
In a first aspect, there is provided a method of fabricating an electrical lead that includes:
providing an elongate tubular member of a non-conductive material, the tubular member defining at least one lumen; accessing the at least one lumen externally of the tubular member by forming at least one aperture in a wall of the tubular member proximate a distal end of the tubular member; inserting at least one conductor into the at least one lumen of the tubular member via the at least one aperture and feeding the at least one conductor toward a proximal end of the tubular member; attaching an electrically conductive element to an exposed distal end of the at least one conductor; mounting the at least one electrical conductive element on an external surface of the tubular member; and treating the tubular member to close off the aperture.
The tubular member may be a multi-lumen member and the method may include accessing only one of the lumens, a conductor lumen, for inserting a plurality of conductors into the conductor lumen.
In an embodiment, the method may include making a longitudinally extending incision in the wall of the tubular member to form the aperture and to access the conductor lumen and inserting the conductors into the conductor lumen through the incision so that a distal end of each conductor protrudes from the incision.
In another embodiment, the method may include making a plurality of transversely extending apertures in the form of slots in the wall of the tubular member and accessing at least one conductor in the conductor lumen through each slot so that a distal end of each conductor protrudes from its associated slot. The method may include, prior to forming the slots, removing some material from the external surface of the wall of the tubular member.
The method may include attaching proximal ends of the conductors to a feeder device and inserting the feeder device through the conductor lumen to pull the conductors through the conductor lumen.
The method may include attaching an electrically conductive element to each of at least some of the conductors, each electrically conductive element being in the form of a ring electrode, which is a snug fit about the tubular member. Each ring electrode may be attached to its associated conductor by inductively welding (or soldering) the conductor to an inner surface of the ring.
The method may include securing each ring electrode in position on the tubular member. Each ring electrode may be secured in position on the tubular member by a suitable adhesive, which may be an epoxy adhesive. The method may include attaching a tip electrode to the distal end of the tubular member in a similar manner.
The method may include charging a filler material into the conductor lumen to insulate the conductors from each other and to inhibit collapsing of the conductor lumen during subsequent operations. The filler material may be a flexible adhesive that is charged into the conductor lumen and allowed to cure.
The method may include treating the tubular member by heat treatment. Further, the method may include heat treating the tubular member by applying a sacrificial heat shrink at least over the at least one aperture to cause material of the tubular member to melt and to flow together to close the at least one aperture.
The at least one electrically conductive element may stand proud of the external surface of the tubular member after being mounted in the tubular member and the method may include, during heat treatment of the tubular member, causing the tubular member to expand outwardly so that a sealing fillet is formed about each edge of the electrically conductive element.
The method may include, prior to heat treating the tubular member, inserting support elements, for example, mandrels, into the remaining lumens of the tubular member to inhibit collapse of the lumens during the heat treatment operation.
The disclosure extends to an electrical lead fabricated in accordance with the method as described above.
In a second aspect there is provided an electrical lead that includes:
an elongate tubular member of a non-conductive material, the tubular member defining at least one lumen; at least one conductor extending through the lumen with a distal end of the conductor protruding through a wall of the tubular member; an electrically conductive element attached to the distal end of the at least one conductor and the electrically conductive element being mounted on the tubular member to form an electrode on the tubular member; and at least a part of the tubular member adjacent each edge of the electrically conductive element having been treated to be caused to expand outwardly to form a sealing fillet along each edge of the electrically conductive element.
The tubular member may be a multi-lumen member having at least a conductor lumen and a stylet lumen. The tubular member may further define an irrigation fluid lumen. The stylet lumen is eccentrically arranged within the tubular member.
The electrical lead may include a plurality of electrodes, each of which has at least one conductor associated with it, the conductors for the electrodes extending through the conductor lumen of the tubular member and a distal end of each conductor protruding through the wall of the tubular member.
Each electrode may be in the form of a ring with the distal end of the conductor of the electrode attached to an inner surface of the ring. The distal end of the conductor may be attached to the inner surface of its associated electrode by induction welding or soldering.
The wall of the tubular member may be heat treated to close an aperture via that the at least one conductor was accessed from the at least one lumen of the tubular member.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:
FIG. 1 shows a perspective view of a catheter assembly including an embodiment of an electrical lead forming a catheter sheath of the catheter assembly;
FIG. 2 shows an end view, on an enlarged scale, of a tubular member of the electrical lead;
FIG. 3 shows a perspective view of an initial stage in an embodiment of a method of fabricating the electrical lead;
FIGS. 4 and 5 show perspective views of stages in another embodiment of a method of fabricating the electrical lead;
FIG. 6 shows a schematic side view of a step of attaching an electrically conductive element in the method of fabricating the electrical lead;
FIG. 7 shows a schematic side view of a step of treating a distal region of the tubular member in the method of fabricating the electrical lead; and
FIG. 8 shows a schematic side view of the distal end of an embodiment of an electrical lead.
DETAILED DESCRIPTION
In FIG. 1 of the drawings, reference numeral 10 generally designates a catheter assembly. The catheter assembly 10 includes a handle 12 . A catheter sheath 14 , made in accordance with an embodiment of a method of fabricating an electrical lead, extends from a distal end 16 of the handle 12 . The catheter sheath 14 defines a plurality of lumens 18 , 20 and 22 ( FIG. 2 ). The lumen 18 is a deflection stylet lumen for receiving a deflection stylet. The lumen 20 is a conductor lumen and has a plurality of conductors 26 received therein. The conductors 26 extend from electrodes 28 ( FIG. 8 ) carried on a distal part 30 of the catheter sheath 14 . The conductors 26 extend through the handle 12 to an electrical connector 32 arranged at a proximal end 34 ( FIG. 1 ) of the handle 12 .
The lumen 22 is an irrigation lumen for providing irrigating fluid to the electrodes 28 at the distal part 30 of the catheter sheath 14 . The lumen 22 communicates with a fluid conduit 36 ( FIG. 1 ). A luer connector 38 is arranged at a proximal end of the conduit 36 for connection to a supply of irrigation fluid (not shown).
As shown in FIG. 3 , in a first embodiment in a method of fabricating an electrical lead for use as the catheter sheath 14 , a length of an elongate tubular member 40 is provided. The tubular member 40 is of a biocompatible, non-conductive material such as, for example, a polyether block amide (PEBAX®).
Proximal ends of the conductors 26 are butted up against a threading device, for example, a mandrel (not shown). The proximal ends of the conductors 26 are secured to the mandrel using a sacrificial heat shrink sleeve 50 (see FIG. 7 ). The mandrel is inserted through the conductor lumen 20 to the proximal end of the tubular member 40 for threading the conductors 26 through the conductor lumen 20 .
An incision 42 is formed by cutting the tubular member 40 longitudinally from an outer surface of the tubular member 40 through to the conductor lumen 20 . Distal ends of the conductors 26 are pulled through the incision 42 to be externally accessible with a wall 44 of the tubular member 40 .
As illustrated in FIG. 6 , in the following step of the method, an electrically conductive element in the form of a ring electrode 28 is attached to a distal end of each conductor 26 . The distal end of the conductor 26 is secured to its associated ring electrode 28 by inductively welding an end of the conductor 26 to an internal surface 48 of the ring electrode 28 . Induction welding is chosen as it provides a consistent result, no new materials are introduced by the welding of the conductor 26 to the ring electrode 28 and it eliminates the need for any intermediate materials.
The ring electrodes 28 are chosen to have an inner diameter that approximates the outer diameter of the tubular member 40 so each ring electrode 28 is a snug fit about an external surface of the tubular member 40 . Once the conductors 26 have been attached to their associated electrodes 28 , the ring electrodes 28 are slid over the end of the distal end of the tubular member 40 and positioned at longitudinally spaced intervals as shown in FIGS. 7 and 8 of the drawings. It will be appreciated that any excess length of conductor 26 can be drawn into the conductor lumen 20 of the tubular member 40 by pulling on the proximal end of the conductor 26 .
After the ring electrodes 28 have been positioned on the tubular member 40 , the end or tip electrode 28 is formed by attaching it to the distal end 30 of the tubular member 40 ( FIG. 8 ).
Once the electrodes 28 have been positioned on the tubular member 40 , the conductor lumen 20 is charged with a filler material, which serves to insulate the conductors 26 with respect to each other and to inhibit collapse of the conductor lumen 20 during subsequent steps. The filler material is, for example, a flexible ultraviolet (UV) adhesive.
The electrodes 28 are secured in position on the tubular member 40 by means of a suitable biocompatible adhesive, for example, an epoxy adhesive.
Mandrels are inserted into the irrigation lumen 22 and the stylet lumen 18 . This supports the tubular member 40 and retains its integrity by inhibiting collapse of the lumens 18 and 22 during a subsequent heating operation.
A sacrificial heat shrink sleeve 50 is placed over the electrodes 28 as shown in FIG. 7 of the drawings. The distal end of the tubular member 40 is heated using a controlled heat source. Heating of the tubular member 40 causes the material of the tubular member 40 to liquefy to an extent and to flow together causing closure of the incision 42 . In addition, radial expansion of the material takes place, the extent of the radial expansion being constrained by the sleeve 50 .
After the heat source has been removed, the sacrificial heat shrink sleeve 50 is also removed. As a result of the radial expansion of the material of the tubular member 40 , the material adjacent the electrodes 28 , as shown at 52 in FIG. 8 , expands radially outwardly and molds around the electrodes 28 to seal the edges of the electrodes 28 and make surfaces of the electrodes 28 substantially flush with surfaces of the parts of the material 52 of the tubular member 40 . Thus, the expanded material 52 forms a sealing fillet about each edge of the electrodes 28 . In so doing, a substantially smooth surface is formed at the end of the now completed catheter sheath 14 and reduces the likelihood of the electrodes 28 snagging on tissue during manipulation of the electrode sheath 14 through the patient's vasculature or in the patient's heart.
Referring now to FIGS. 4 and 5 of the drawings, a second embodiment of a method of fabricating an electrical lead to provide the catheter sheath 14 is illustrated. With reference to the other drawings, like reference numerals refer to like parts, unless otherwise specified.
In this embodiment, a flat section of the tubular member 40 is machined or skived to provide a land 54 ( FIG. 4 ). After this step, a plurality of transversely extending slots 56 , one for each ring electrode 28 (not shown), are formed in the land 54 as shown in FIG. 5 of the drawings. As illustrated, the slots 56 are cut to a sufficient depth to intersect the conductor lumen 20 .
In this embodiment, the distal ends of the conductors 26 ( FIG. 2 ) are drawn out of the slots 56 using an appropriate gripping device such as a pair of tweezers or the like. The remaining procedure of forming the catheter sheath 14 is the same as described above with reference to FIGS. 3 and 6-8 of the drawings. The land 54 facilitates the insertion of the adhesive beneath the ring electrodes 28 so that the adhesive is received in the slots 56 to assist in sealing the slots 56 .
It is an advantage of the described embodiments that a method of fabricating an electrical lead is provided that simplifies the procedure of producing a suitable catheter sheath. In addition, the use of the heating technique to cause flow of the material of the tubular member assists in sealing the lumens of the tubular member against the ingress of foreign material. This heating technique also serves to assist in retaining the electrodes in position on the tubular member.
Reference throughout this specification to “one embodiment,” “some embodiments” or “an embodiment” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment,” “in some embodiments” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment, but may. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments.
As used herein, unless otherwise specified, the use of ordinal adjectives “first,” “second,” “third,” etc., to describe a common object, merely indicate that different instances of like objects are referred to, and are not intended to imply that the objects so described must be in a given sequence, either temporally, spatially, in ranking, or in any other manner.
In the appended claims and the description herein, any one of the terms “comprising,” “comprised of,” or “which comprises” is an open term that means including at least the elements/features that follow, but not excluding others. Thus, the term “comprising,” when used in the claims, should not be interpreted as being limitative to the means or elements or steps listed thereafter. For example, the scope of the expression “a device comprising A and B” should not be limited to devices consisting only of elements A and B. Any one of the terms “including,” “which includes,” or “that includes,” as used herein, is also an open term that also means including at least the elements/features that follow the term, but not excluding others. Thus, “including” is synonymous with and means “comprising.”
It should be appreciated that in the above description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the Detailed Description are hereby expressly incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment of this invention.
Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be understood by those skilled in the art. For example, in the appended claims, any of the claimed embodiments can be used in any combination.
In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the invention may be practiced without these specific details. In other instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.
Similarly, it is to be noticed that the term “coupled,” when used in the claims, should not be interpreted as being limited to direct connections only. The terms “coupled” and “connected,” along with their derivatives, may be used. It should be understood that these terms are not intended as synonyms for each other. Thus, the scope of the expression “a device A coupled to a device B” should not be limited to devices or systems wherein an output of device A is directly connected to an input of device B. It means that there exists a path between an output of A and an input of B, which may be a path including other devices or means. “Coupled” may mean that two or more elements are either in direct physical or electrical contact, or that two or more elements are not in direct contact with each other but yet still cooperate or interact with each other.
Thus, while there has been described what are believed to be the preferred embodiments of the invention, those skilled in the art will recognize that other and further modifications may be made thereto without departing from the spirit of the invention, and it is intended to claim all such changes and modifications as falling within the scope of the invention. For example, any formulas given above are merely representative of procedures that may be used. Functionality may be added or deleted from the block diagrams and operations may be interchanged among functional blocks. Steps may be added or deleted to methods described within the scope of the invention.
It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the disclosure as shown in the specific embodiments without departing from the scope of the disclosure as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.
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A catheter includes a handle, a catheter sheath having at least one conductor within a lumen of the catheter sheath, and a stylet received within the catheter sheath. The catheter sheath is fabricated by providing a tubular member, forming an aperture in a wall of the tubular member at a distal part of the tubular member and inserting a conductor into the lumen of the tubular member. An exposed distal end of the conductor is attached to an electrode, which is then mounted onto an external surface of the tubular member to cover the aperture. The tubular member is then treated by heat to seal the electrode.
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This application claims the benefit of the Patent Korean Application No. P2004-091991, filed on Nov. 11, 2005, which is hereby incorporated by reference as if fully set forth herein.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a controller effectively controlling the power for a washing machine or a drier, and a method of doing the same, and more particularly, to a controller for a washing machine or a dryer, and a method for supplying the power so that a washing machine and a drier as a one body may perform an optimal efficiency in a range of a current limit, when supplied the power by the same power source.
2. Discussion of the Related Art
FIG. 1 is a diagram illustrating a related art device combining a washing machine and a dryer.
As sown in FIG. 1 , a washing machine 10 and a dryer 20 are included. At a top of the washing machine 10 are formed a display part 11 for displaying operation of the washing machine and an opening part 12 for having the laundry loaded therein or vice versa. At a top of the dryer are formed a display part 21 for displaying operation of the dryer 20 and an opening part 22 for having the laundry loaded therein or vice versa.
In general, every electric home appliance has an optimal performance current for performing the optimal efficiency. There are some cases of not supplying an optimal performance current due to other reasons, and that is caused by a current limit.
The current limit is an electric current value limited for securing the customer, preventing a fire caused by overheating an electric home appliance, and an accident of an electric shock caused by electric leakage due to overflowing currents in the electric home appliances. A designer of an electric home appliance should set an optimal performance current in a range of a current limit value. Especially, the sum total of the whole currents for an electric home appliance combining more than two products should not exceed the current limit, even in case that the more than two machines are put into operation at the same time.
For example, under the regulations a current limit of an average American house should not exceed 15 amps (A), and in that case, the sum total of a current consumption for the electric home appliance should not exceed 15 amps.
For example, when designing a device combining a washing machine and a dryer, the current consumption in case of putting the washing machine and the dryer into operation at the same time should meet the current limit. Thus, each electric home appliance has an optimal performance current, and since the security of the costumers has to be put into consideration, the device should be designed to find an optimum level between its optimal performance current and the current limit and to perform the optimal efficiency within the range.
Generally, the optimal performance current is determined by independent operation of each product. If more than two products are operated at the same time and the current value satisfying each optimal performance current of the products is provided, the current value would exceed the current limits of the products. Also, even in case that each product is not operated at the same time to satisfy the current limit values of each product, an amount of currents is reduced in advance, preparing against the case of operating the products simultaneously. Thereby permanent current loss may be cased as shown in FIG. 2 .
Referring to FIG. 2 , a method of supplying the power for the related art washing machine and dryer will be described.
A product 1 (a washing machine) and a product 2 (a dryer) drive by means of lower currents 32 and 42 than each optimal performance current thereof 33 and 43 , even when the product 1 and 2 are operated separately. That is, even when either of the two products is operated, the two products are designed to drive by the regularly lower currents 32 and 42 than the optimal performance currents 33 and 43 for being prepared against the case of operating the two products simultaneously. Thus, the following problem may be caused. Since the current loss 31 and 41 of the products are expected in advance, neither of the two products may perform its optimal efficiency although either of the products is operated.
SUMMARY OF THE INVENTION
Accordingly, the present invention is directed to a controller effectively controlling the power for a washing machine or a dryer, and a method for doing the same.
An object of the present invention is to provide a method of controlling the power for a washing machine or a dryer to be operated at an optimal performance in a range satisfying a current limit.
Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, a controller for a washing machine comprising a micom wherein an optimal performance current value for the washing machine and an electric current limit for concurrent operation of the washing machine and a dryer are set therein; and communication means for communicating with a controller of the dryer, wherein the micom determines through the communication with the dryer the electric current value to be supplied to the washing machine according to an operation state of the dryer.
The micom determines the electric current value to be supplied to the washing machine as the optimal performance current value of the washing machine, once a motor for driving a drum of the dryer is judged not to be operated.
Also, the micom determines the electric current value to be supplied to the washing machine, corresponding to a ratio of between the optimal performance current values of the dryer and the washing machine, once the motor for driving the drum of the dryer is judged to be operated.
Alternatively, the micom determines the electric current value to be supplied to the washing machine as one of the optimal performance current value of the washing machine and the electric current value given after subtracting the optimal performance current value of the dryer from the current limit value, once the motor for driving the drum of the dryer is judged to be operated. As described above, the determination may be made by setting it in the micom in advance, or by inputting it outside, for example, an input button or determination means such as an auxiliary home network.
In another aspect of the present invention, a controller for a dryer comprising a micom wherein an optimal performance current value for the dryer and an electric current limit for concurrent operation of the washing machine and the dryer are set therein; and communication means for communicating with the controller of the washing machine. The micom determines through the communication with the washing machine the electric current value to be supplied to the dryer according to an operation state of the washing machine.
Just like in the controller of the washing machine, the micom of the controller for the dryer determines the electric current value to be supplied to the dryer as the optimal performance current value of the dryer, once a motor for driving the drum of the washing machine is judged not to be operated.
Also, the micom determines the electric current value to be supplied to the dryer out of the electric current limit, corresponding to a ratio of the optimal performance current values between the dryer and the washing machine, once the motor for driving the drum of the washing machine is judged to be operated.
Alternatively, the micom determines the electric current value to be supplied to the dryer as one of the optimal performance current value of the dryer and the electric current value given after subtracting the optimal performance current value of the washing machine from the current limit value, once the motor for driving the drum of the washing machine is judged to be operated. The determination may be made by setting it in the micom in advance, or by inputting it outside as described above in the controller of the washing machine.
On the other hand, a method of controlling the power for a washing machine or a dryer comprising a first step; a second step; and a third step. The first step is for setting in the micom each optimal performance current value of the washing machine and the dryer, and a current limit value for the washing machine and the dryer to be operated safely when operating the washing machine and the dryer simultaneously. Hence, the second step is for exchanging and communicating operation information of the washing machine and the dryer by using a communication port connected to each micom of the washing machine and the dryer. The third step is for of supplying currents to the washing machine and the dryer in a range of the current limit according to the operation information.
In the third step, in case only the washing machine is operated, the washing machine is supplied its optimal performance current value. In case only the dryer is operated, the dryer is supplied its optimal performance current value. Then, in case the washing machine and the dryer are operated simultaneously, the current value is divided and supplied to each of the washing machine and the dryer.
In the third step, in case the currents are divided and supplied to each of the washing machine and the dryer, the current limit value is divided by a ratio of each optimal performance current value of the washing machine and the dryer.
Furthermore, a priority setting step of setting priority is further comprised between the first and second step. Thus, in case the washing machine and the dryer are operated simultaneously in the third step, one of the washing machine and the dryer chosen by the priority in the priority setting step is supplied its optimal performance current, and the other product is supplied the currents given after subtracting the optimal performance current value from the current limit value.
In the priority setting step, the priority may be set through a home server of a home network system.
On the other hand, the communication means according to the present invention is employed for communicating if the driving part of the washing machine and the dryer is operated or not. But, the communication means may communicate data more than that.
One example for the washing machine and the dryer to communicating each other will be described. The one product sends an electric signal through a communication cable for allowing the other product to know if a motor of the one product is switched on. Hence, the other product receives the signal to judge of the motor of the one product is operated, and then determines which current value to use.
According to the present invention, in case that one of the products is operated, or the products are operated at the same time, the currents are supplied for performing the optimal efficiency, thereby preventing the permanent current loss. Also, accidents caused by over-supplying currents are prevented, and the security of the customers is kept.
It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings:
FIG. 1 is a diagram illustrating a configuration of a device combining a conventional washing machine and dryer.
FIG. 2 is a graph illustrating a method of controlling the power for a related art washing machine and dryer.
FIG. 3 is a graph of a current when only a washing machine is operated by a method of controlling the power for a washing machine and a dryer according to the present.
FIG. 4 is a diagram schematically illustrating the method of controlling the power for the washing machine and the dryer according to the present invention.
FIG. 5 is a flow chart illustrating the method of controlling the power for the washing machine and the dryer according to the present invention.
FIG. 6 is a flow chart illustrating another method of supplying the power for the washing machine and the dryer according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.
FIG. 4 is a diagram schematically showing that each controller of a washing machine and a dryer controls the power of the washing machine and the dryer. The controller includes a micom and communication means.
As shown in FIG. 4 , the washing machine 100 includes a micom 110 , a communication port 120 connected to the micom for communicating with the dryer 200 , and a power supply unit 130 for supplying the power to the washing machine.
Also, the dryer 200 includes a micom 210 , a communication port 220 connected to the micom for communicating with the washing machine 100 , and a power supply unit 130 for supplying the power to the dryer 200 .
The communication port 120 of the washing machine and the communication port 220 of the dryer are connected by a communication cable to exchange and communicate operation information each other. The power supply units 130 and the 230 are operated to supply the power needed for each of the washing machine and the dryer by means of the control of each micom 110 and 210 .
First of all, each optimal performance current value for the washing machine and the dryer, and a current limit value are set in the each micom 110 and 210 . Each optimal performance current value is for the washing machine and the dryer to perform the optimal efficiency, and the current limit value is a maximum vale of currents to use the two products safely when the two products are operated simultaneously.
The micoms 110 and 210 divide the currents supplied to the washing machine and the dryer for performing an optimal efficiency within a range of the current limit, and instruct to supply the currents to the washing machine and the dryer. The micoms 110 and 210 check through the communication ports 120 and 220 in advance whether the washing machine and the dryer are required to be operated or not. If only the washing machine is required to be operated, the micoms 110 instructs the power supply unit 130 to supply the washing machine its optimal performance current. Whereas, if only the dryer is required to be operated, the micom 210 instructs the power supply unit 130 to supply the dryer its optimal performance current. If both of the washing machine and the dryer are required to be operated simultaneously, the micoms 110 and 210 instruct the power supply units 130 and 230 of the washing machine and the dryer to supply the currents that remains after dividing the current limit by each optimal performance current ratio of the washing machine and the dryer to each of the washing machine and the dryer.
Referring to FIG. 3 , a case will be described that a product 1 (the washing machine) is operated and a product 2 (the dryer) is not operated.
Once it is judged that the washing machine is required to be operated and the dryer is not, the washing machine is supplied its optimal performance current value 61 .
That is, since the micoms of the products 1 and 2 check the interaction of the products 1 and 2 , and supply each optimal performance current of the two products, the permanent current loss 31 and 41 shown in FIG. 2 may not be created. Although the currents are supplied in that way, the currents may not exceed the current limit 63 , thereby possible to supply the currents safely and efficiently.
Also, auxiliary control means may be provided outside of the washing machine and the dryer as necessary. The auxiliary control means gives the priority to the washing machine or the dryer, and allows either of the two products 1 and 2 operated by its optimal performance current. Alternatively, the priority may be set in advance in each micom of the products 1 and 2 . Alternatively, an input button may be provided for a user to input the priority directly.
FIG. 4 shows a case that the control means is provided by using a home network system. The home network system is a system that controls and manages electric home appliances such as a washing machine, a refrigerator, a television, a VCR, an electric heater, and a lightning unit in a building by using a communication unit such as a mobile phone, and a public phone outside the building after connecting the electric home appliances with a cable or wirelessly.
The home network system requires a home server 300 connected with an outside communication network, for example a refrigerator, for controlling the electric home appliances connected with a home network system and exchanging information. A micom 310 provided in the home server 300 is connected to the micoms 110 and 210 of the washing machine and the dryer in a home network system. The micom 310 also controls the power supply of the two products 1 and 2 according to the present invention.
More specifically, the user inputs the priority into the micom 310 of the home server 300 , and then it is determined by the inputted priority which of the washing machine and the dryer is put into operation in its optimal efficiency. In case that the washing machine and the dryer are operated simultaneously, the priority is applied. In that case, the micoms 110 and 210 instruct the power supply unit of the product 1 or 2 determined by the priority to supply its optimal performance current to the product determined by the priority inputted in the micom 310 of the home sever 300 . Hence, the micoms 110 and 210 also instruct the power supply unit of the other product 1 or 2 to supply the remaining currents except the optimal performance current to the other product 1 or 2 . Thus, the optimal performance current may be supplied to the one product determined prior to the other product.
Next, referring to FIG. 5 , a method of a power supply for a washing machine and a dryer according to the present invention will be described.
First, the method includes a first step (S 1 ) in which a current limit value and each optimal performance current of the washing machine and a dryer are set in micoms each provided in the washing machine and the dryer. The current limit value is a maximum value used in the two products 1 and 2 when the two products 1 and 2 are operated simultaneously, and a value set for the two products to be operated safely. Also, each optimal performance current is a current value designed for each product to perform its optimal efficiency. Each optimal performance current value should be in a range of the current limit value.
Next, a second step (S 2 ) is included in which operation information of the washing machine and the dryer is exchanged and communicated by using communication ports connected each other provided in each micom. The operation information is a signal showing whether the washing machine or the dryer is operated or not.
Next, a third step is included in that currents are supplied in a range of the current limit according to operation information of the washing machine and the dryer.
In the third step, the currents are supplied as follows. First, it is checked if the washing machine is required to be operated (S 3 ). Then, it is checked if the dryer is required to be operated in case that the washing machine is not required to be operated (S 4 ). In case the dryer is required to be operated, the optimal performance current of the dryer is supplied to the dryer (S 5 ).
In the S 3 step, in case that the washing machine is required to be operated, it is checked again if the dryer is required to be operated (S 6 ). Judged that the dryer is not required to be operated, the optimal performance current of the washing machine is supplied to the washing machine (S 7 ).
In case that the washing machine and the dryer are all required to be operated, after dividing the current limit by each optimal performance current value of the washing machine and the dryer, the given currents are supplied to each of the washing machine and the dryer (S 8 ).
As shown in FIG. 6 , the user may put more emphasis on either of the washing machine and the dryer as necessary, in case that the two products are operated simultaneously. For that, a priority setting step (S 12 ) may be further included between a step (S 11 ) of FIG. 6 corresponding to the step 1 of FIG. 5 and a step (S 13 ) of FIG. 6 corresponding to the step S 2 of FIG. 5 . In the step (S 12 ), auxiliary control means may be further provided in the washing machine and the dryer for setting the priority. The control means may use the micom in the home server of the home network system for controlling.
When the washing machine and the dryer are operated simultaneously, according to the priority, either of the two products is supplied its optimal performance current. Hence, the other product is supplied the currents given after subtracting its optimal performance from the current limit value (S 19 ).
The method of controlling the power for the washing machine and the dryer according to the present invention may be applied by using a communication module connecting the micoms of the washing machine and the dryer each other, in case that the power is supplied by the same current source after connecting a conventional washing machine and a conventional dryer.
It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventions. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.
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The present invention relates to a controller effectively controlling the power for a washing machine and a drier, and a method of doing the same. More particularly, it relates to a controller for a washing machine or a dryer, and a method for supplying the power so that a washing machine and a drier as a one body may perform an optimal efficiency in a range of a current limit, when supplied the power by the same power source. A controller for a washing machine comprising a micom; and communication means for communicating with a controller of a dryer. A controller for a dryer comprising a micom; and communication means for communicating with the controller of the washing machine.
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BACKGROUND OF THE INVENTION
[0001] The invention relates to a high-pressure pump, in particular a radial or inline piston pump. The invention relates particularly to the field of fuel pumps for fuel injection systems of air-compressing auto-ignition internal combustion engines.
[0002] A high-pressure pump for a fuel injection device of an internal combustion engine is known from DE 10 2005 046 670 A1. The known high-pressure pump has a multipart pump casing in which at least one pump element is arranged. The pump element comprises a pump piston which is driven in a lifting movement by a driveshaft and which is guided displaceably in a cylinder bore of part of the pump casing and in this cylinder bore delimits a pump working space. In this case, the driveshaft has a cam, the pump piston being driven by the cam of the driveshaft in a radial direction with respect to an axis of rotation of the driveshaft. Between the pump piston and the cam of the driveshaft, a tappet is arranged, via which the pump piston is supported on the cam of the driveshaft via a roller. A supporting element in which the roller is mounted rotateably is inserted into the tappet, the roller rolling on the cam of the driveshaft. The axis of rotation of the roller is in this case approximately parallel to the axis of rotation of the driveshaft.
[0003] The high-pressure pump known from DE 10 2005 046 670 A1 has the disadvantage that pulsating stress upon the cam and the running roller occurs during operation and leads to material fatigue.
SUMMARY OF THE INVENTION
[0004] The high-pressure pump according to the invention affords the advantage that reliable operation, particularly improved durability of the cam and/or of the running roller, is achieved. In particular, the cam and running roller have an improved configuration in terms of the pulsating stress occurring during operation.
[0005] It is advantageous that a radius of the running roller is smaller than a radius of curvature of the cam at a point on the running surface at which the running roller comes to bear at top dead center of the pump subassembly, and that a modulus of elasticity of a running roller material, from which the running roller is formed at least on its roller surface, is lower than a modulus of elasticity of a cam material, from which the cam is formed at least on its running surface. As a result, with the running roller and the cam having different geometries, the amount of critical pulsating stress for the running roller and the cam during operation can be rated so as to be equally critical. It is thereby possible to optimize a yield strength of the running roller and a yield strength of the cam. At top dead center, the Hertzian stress on the roller surface of the running roller is equal to the Hertzian stress on the running surface of the cam. The Hertzian stress must in each case be lower than the yield strength of the running roller and of the cam. Advantageously, by the configuration of the running roller being adapted to the cam, the fatigue of both components, running roller and cam, can be optimized.
[0006] It is advantageous that the radius of the running roller is smaller than the radius of curvature of the cam at the point on the running surface at which the running roller comes to bear at top dead center of the pump subassembly, and that the running roller has at least one bore which extends at least partially in the direction of an axis of rotation of the running roller. In this case, it is advantageous, furthermore, that the bore is configured at least essentially as an axial or at least essentially as a coaxial bore with respect to the axis of rotation of the running roller, and/or that the bore is configured as a through bore which extends from one side of the running roller to another side of the running roller. As a result, with different geometries, a reduction in the rigidity of the running roller in the region of its roller surface can be achieved at top dead center.
[0007] It is also advantageous that the radius of the running roller is smaller than the radius of curvature of the cam at the point on the running surface at which the running roller comes to bear at top dead center of the pump subassembly, and that at least one characteristic compressive stress of the running roller on its roller surface is increased. In particular, it is advantageous that the roller surface of the running roller is case-hardened and/or shot-peened and/or tumbled and/or nitrided and/or carbonitrided. As a result, with the running roller and the cam having different geometries, the rolling resistance of the running roller at top dead center can be increased by the introduction of characteristic compressive stress on the surface. It is thereby possible to adapt the running roller advantageously to the cam.
[0008] It is advantageous that the radius of the running roller is larger than the radius of curvature of the cam at the point on the running surface at which the running roller comes to bear at top dead center of the pump subassembly, and that the modulus of elasticity of the running roller material, from which the running roller is formed at least on its roller surface, is higher than the modulus of elasticity of the cam material, from which the cam is formed at least on its running surface. It is thereby possible for the running roller and the cam to be advantageously adapted to one another. It is also possible, in this case, that at least one characteristic compressive stress of the cam on its running surface is increased.
[0009] It is advantageous that a modulus of elasticity and/or rolling resistance and/or Poisson ratio of the running roller material, from which the running roller is formed at least on its roller surface, and a modulus of elasticity and/or rolling resistance and/or Poisson ratio of the cam material, from which the cam is formed at least on its running surface, are in each case stipulated to be at least approximately equal, and that a radius of the running roller and a radius of curvature of the cam in the region of a point on the running surface at which the running surface comes to bear at top dead center of the pump subassembly are stipulated to be at least approximately equal. For example, the running roller and the cam may be formed from identical or comparable steels which are configured identically or comparably in terms of the moduli of elasticity, rolling resistance and Poisson ratio. In this case, the radius of curvature of the cam in the region of top dead center is designed to be at least approximately equal to the radius of the running roller, thus resulting in advantageous adaptation. It is in this case advantageous, furthermore, that the radius of the running roller and the radius of curvature of the cam at the point on the running surface at which the running roller comes to bear at top dead center of the pump subassembly deviate from one another by less than 5%.
[0010] Preferred exemplary embodiments of the invention are explained in more detail in the following description by means of the accompanying drawings in which corresponding elements are given identical reference symbols and in which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 shows a high-pressure pump in a diagrammatic axial sectional illustration according to an exemplary embodiment of the invention, and
[0012] FIG. 2 shows, as a detail, a section through the high-pressure pump illustrated in FIG. 1 along the sectional line designated by II.
DETAILED DESCRIPTION
[0013] FIG. 1 shows a high-pressure pump 1 in a diagrammatic axial sectional illustration according to a first exemplary embodiment of the invention. The high-pressure pump 1 may serve particularly as a radial or inline piston pump for fuel injection systems of air-compressing auto-ignition internal combustion engines. The high-pressure pump 1 is especially suitable for a fuel injection system with a common rail which stores diesel fuel under high pressure. The high-pressure pump 1 according to the invention is also suitable, however, for other applications.
[0014] The high-pressure pump 1 has a multipart casing 2 . In this exemplary embodiment, the casing 2 is composed of the casing parts 3 , 4 , 5 , the casing part 3 constituting a basic body, the casing part 4 a cylinder head and the casing part 5 a flange fastened to the basic body 3 .
[0015] The high-pressure pump 1 has a driveshaft 6 which is mounted in the casing parts 3 , 5 at bearing points 7 , 8 . Between the bearing points 7 , 8 , the driveshaft 6 has a cam 9 . In this exemplary embodiment, the cam 9 is configured as a double cam. The cam 9 may also be configured as a single cam or another multiple cam.
[0016] The casing part 3 of the high-pressure pump 1 has a guide bore 12 in which a pump subassembly 13 is arranged. The cam 9 is assigned to the pump subassembly 13 . Depending on the configuration of the high-pressure pump 1 , a plurality of pump subassemblies corresponding to the pump subassembly 13 may also be provided. Such pump subassemblies may be assigned to the cam 9 or to another cam which corresponds to the cam 9 . As a result, depending on the configuration, a radial or inline piston pump can be implemented.
[0017] The casing part 4 configured as a cylinder head has an extension 14 which extends into the guide bore 12 . The extension 14 has a cylinder bore 15 in which a piston 16 is guided displaceably in the direction of an axis 17 of the guide bore 12 , as indicated by a double arrow 18 . The piston 16 delimits a pump working space 19 in the cylinder bore 15 . Fuel can be introduced into the pump working space 19 from a fuel duct 21 via an inlet valve 20 provided on the casing part 4 . Furthermore, on the casing part 4 , an outlet valve 22 is provided, via which fuel which is under high pressure can be routed out of the pump working space 19 to a fuel duct 13 . The fuel duct 13 may, for example, be connected to a common rail in order to carry fuel which is under high pressure to the common rail.
[0018] The pump subassembly 13 has a running roller 25 which is received by a roller shoe 26 . The roller shoe 26 is in this case inserted in an essentially hollow-cylindrical tappet body 27 . Furthermore, the tappet body 27 is connected to a disk-shaped driving element 28 which surrounds the piston 16 above a collar 29 of the piston 16 . The piston 16 is thereby held via its collar 29 in bearing contact with the roller shoe 26 . Furthermore, a piston spring 30 is provided, which acts upon the tappet body 27 and/or the driving element 28 and thus acts with some spring force upon the tappet body 27 , together with the piston 16 , in the direction of the running roller 25 . The piston 16 with its collar 29 , the roller shoe 26 , the roller 25 and a running surface 10 of the cam 9 thereby bear in each case one against the other, this mutual bearing contact being ensured even at high rotational speeds of the high-pressure pump 1 .
[0019] When the high-pressure pump 1 is in operation, the to-and-fro movement, indicated by the double arrow 18 , of the piston 16 is thereby achieved, so that the conveyance of fuel which is under high pressure to the common rail takes place. During a pump stroke of the piston 16 for conveying fuel to the common rail via the fuel duct 23 , a relatively high pump force F ( FIG. 2 ) acts via the roller shoe 26 upon the running roller 25 . The running roller 25 is in this case supported on the running surface 10 .
[0020] When the high-pressure pump 1 is in operation, the driveshaft 6 rotates about an axis 31 . Furthermore, the running roller 25 runs on the running surface 10 of the cam 9 . An axis of rotation 32 of the running roller 25 is in this case oriented at least approximately parallel to the axis 31 of the driveshaft 6 . The running roller 25 has a roller surface 35 . The running roller 25 rolls with its roller surface 35 on the running surface 10 of the cam 9 during operation.
[0021] The high-pressure pump 1 of the exemplary embodiment is also described in more detail below with reference to FIG. 2 .
[0022] FIG. 2 shows, as a detail, a section through the high-pressure pump 1 illustrated in FIG. 1 along the sectional line designated by II. In this case, FIG. 2 shows a situation where top dead center of the pump subassembly 13 is reached. The running roller 25 in this case bears with its roller surface 35 at a point 36 on the running surface 10 of the cam 9 . In this position or in the region of this position, the highest stress upon the running roller 25 and the cam 9 occurs. In this case, the maximum conveying stroke of the piston 16 of the pump subassembly 13 is reached, so that the maximum pressure capable of being generated by the high-pressure pump 1 prevails in the pump working space 19 . This is reflected in a correspondingly high force F.
[0023] The running roller 25 and the cam 9 may be produced from hardened high-strength tool steels. In this case, a geometric configuration and a running roller material of the running roller 25 and a geometric configuration of the cam and a cam material of the cam 9 are selected such that a rolling stress-bearing capacity of the running roller 25 and a rolling stress-bearing capacity of the cam 9 on the running surface 10 of the cam 9 are stipulated to be at least approximately equal. In this exemplary embodiment, in particular, the rolling stress-bearing capacity of the cam 9 at the point 36 on its running surface 10 is relevant, since maximum rolling stress upon the cam 9 occurs here. By the cam 9 being configured as a double cam 9 , a correspondingly high rolling stress also occurs at a further point 37 on the running surface 10 of the cam 9 . The point 37 is in this case arranged opposite the point 36 on the running surface 10 with respect to the axis 31 of the driveshaft 6 .
[0024] The running roller 35 is of at least approximately cylindrical configuration. The running roller 25 has a radius 38 with respect to its roller surface 35 . Moreover, the cam has a circumferentially varying radius of curvature with respect to its running surface 10 . Since the highest rolling stress upon the cam 9 occurs in the region of the points 36 , 37 , a radius of curvature 39 at the point 36 at which the running roller 25 bears against the running surface 10 at top dead center of the pump subassembly 13 is relevant. In this case, for the point 37 , a corresponding radius of curvature 40 which is equal to the radius of curvature 39 is obtained.
[0025] Depending on the configuration of the high-pressure pump 1 , the radius 38 of the running roller 25 may be equal to, smaller than or even larger than the radius of curvature 39 of the cam 9 .
[0026] In the position, illustrated in FIG. 1 , of the cam 9 at top dead center of the pump subassembly 13 , the Hertzian stress on the running surface 10 of the cam 9 and on the roller surface 35 of the running roller 25 is equal for both components 9 , 25 . For reliable operation, this Hertzian stress must be lower than the yield strength of the components, running roller 25 and cam 9 . Since stress occurs highly dynamically during operation, fatigue of the running roller 25 and/or fatigue of the cam 9 are/is important for the purpose of reliable operation. The pulsating stress of the running roller 25 and of the cam 9 has its maximum below the roller surface 35 or the running surface 10 respectively. Furthermore, the pulsating load is dependent on the stress, geometry, in particular the radius 38 of the running roller 25 , and the radii of curvature 39 , 40 on the points 36 , 37 , and the modulus of elasticity of the running roller 25 or of the cam 9 . For the purpose of reliable operation over the lifetime of the high-pressure pump 1 , the pulsating stress should not overshoot the permissible rolling resistance of the material or materials used for the components 25 , 9 . The pulsating stress has in this case an all the greater effect, the smaller the radius 38 of the running roller 25 or the radius of curvature 39 of the cam 9 is. The component 25 , 29 which has the smaller radius 38 or radius of curvature 39 is therefore subjected to a greater load.
[0027] Advantageously, the critical pulsating stress for both components 9 , 25 is rated to be equally critical in terms of the permissible rolling stress. Examples of possible ratings are described further below.
[0028] If the radius 38 of the running roller 25 is stipulated to be smaller than the radius of curvature 39 of the cam 9 , then advantageously a modulus of elasticity of the running roller material, from which the running roller 25 is formed at least in the region of its roller surface 35 , is lower than a modulus of elasticity of the cam material, from which the cam 9 is formed at least in the region of its running surface 10 . It is also possible in this case that the running roller has at least one bore 41 . Such a bore 41 makes it possible to reduce the rigidity of the running roller 25 , particularly in the region of its roller surface 35 . The bore 41 is preferably configured as an axial or coaxial bore 41 . In this exemplary embodiment, the bore 41 is configured as an axial bore which extends along the axis of rotation 32 of the running roller 25 . In this exemplary embodiment, the bore 41 is configured as a through bore 41 . The bore 41 extends from one side 42 of the running roller 25 as far as another side 43 of the running roller 25 which faces away from the side 42 .
[0029] In the case where the radius 38 of the running roller 25 is smaller than the radius of curvature 39 of the cam 9 at the point 36 on the running surface 10 , it is also advantageous that characteristic compressive stresses of the running roller 25 on its roller surface 35 are increased. In this case, the running roller 25 may be machined in the region of its roller surface 35 . In particular, case hardening of the roller surface 35 , shot peening of the roller surface 35 , tumbling of the roller surface 35 , nitriding of the roller surface 35 or else carbonitriding of the roller surface 35 are possible. As a result, the rolling resistance of the running roller 25 , in particular of the roller surface 35 of the running roller 25 , can be increased by the introduction of characteristic compressive stresses on the roller surface 35 .
[0030] In a case where the radius 38 of the running roller 25 is larger than the radius of curvature 39 of the cam 9 , it is advantageous that the modulus of elasticity of the running roller material, from which the running roller 25 is formed, is higher than the modulus of elasticity of the cam material, from which the cam 9 is formed at least on its running surface 10 . Load compensation is thereby possible, in order to achieve identical or at least comparable loading both for the running roller 25 and for the cam 9 . Machining, in particular surface machining, of the cam 9 is also possible. This may be carried out correspondingly to a surface machining of the roller surface 35 of the running roller 25 .
[0031] In a case where the radius 38 of the running roller 25 and the radius of curvature 39 of the cam 9 at the point 36 on the running surface 10 are at least approximately equal, it is advantageous that the running roller material of the running roller 25 and the cam material of the cam 9 have in each case at least approximately an equal modulus of elasticity, at least approximately an equal rolling resistance and/or at least approximately an equal Poisson ratio. This makes it possible to have both a comparable geometry and a pairing of comparable or identical materials for the running roller 25 and the cam 9 in the region of the points 36 , 37 . Identical or at least comparable stressing can thereby be achieved.
[0032] The radius 38 of the running roller 25 and the radius of curvature 39 of the cam 9 in this case differ from one another preferably by less than 5%.
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The invention relates to a high pressure pump ( 1 ), which is used in particular as a radial or in-line piston pump for fuel injection systems of air-compressing auto-ignition internal combustion engines, comprising a pump assembly ( 13 ) and a drive shall ( 6 ) which comprises a cam ( 9 ) that is assigned to the pump assembly ( 13 ). The pump assembly ( 13 ) comprises a roller ( 25 ) which rolls with the roller surface ( 35 ) thereof on a running surface ( 10 ) of the cam ( 9 ). A rolling strength of the roller ( 25 ) on the roller surface ( 35 ) of the roller ( 25 ) and a rolling strength ( 9 ) of the running surface ( 10 ) of the cam ( 9 ) are specified as being identical. Under the highly dynamic stress of the cam ( 9 ) and the roller ( 25 ) during operation, this results in a critical threshold tension for both components ( 9, 25 ), which is equally critical for both components ( 9, 25 ).
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This present invention relates to a method and apparatus for controlling thermoplastic friction welding machines. More particularly, the present invention relates to an electromechanical method and apparatus for determining the quality of a spinwelded bond produced by a single or multiple spindle production spinwelder and further to a method and apparatus for alarming and/or ejecting products containing defective welds.
2. Background of the Invention
In the art of joining thermoplastic articles by friction welding, a device may be used which spinwelds thermoplastic axially mating sections. The sections are driven in rotation relative to each other and then axially abutted in mating relationship. In a device, such as that disclosed in U.S. Pat. No. Re 29,448, one of the two mating sections is chucked to an initial member which is brought up to speed by a rotary drive. The rotary drive is uncoupled as the sections are moved into axial abutment and the breaking of the inertia member by the axial abutment of the sections is transformed into frictional heat which welds the thermoplastic seams to each other.
The apparatus described above may typically be a part of a larger apparatus such as that disclosed in U.S. Pat. No. 3,800,376 for performing a plurality of successive operations with individual container sections.
The processing operations may typically include the dispensing of container sections and the assembly, filling and sealing of the containers. On a single platform, a plurality of spaced processing units may be rotatably mounted. Each unit will typically include a plurality of circumferentially spaced carrier stations for moving container sections or containers about the unit axis of rotation. A plurality of spaced star wheel transfer units may then be disposed intermediate and adjacent to the processing units. The star wheels receive container sections or containers from and deliver them to the processing units at transfer zones defined generally tangentially of each of the processing units and an adjacently disposed star wheel unit. A transfer unit may be rotatably mounted on the platform and may include a plurality of circumferentially spaced carrier stations for moving the container sections or containers about the axis of rotation. The circumferential spacing of the carrier station on the transfer and processing units will typically be substantially the same throughout; and the transfer and processing units are geared together for simultaneous rotation, with the carrier stations of each of the processing units and an adjacently disposed transfer unit rotating in opposite angular directions. The initial processing units will typically have dispensers for supplying individual container sections to an adjacent transfer unit.
In addition, the invention may be useful with a friction welding machine for joining thermoplastic container top and bottom parts which are moved continuously along a production line as disclosed in U.S. Pat. No. 3,759,770. Star wheel loading and unloading members incorporating suction pads for gripping the parts as they move to the holders where flutes, in at least some of the holders, communicate the suction chambers in the holders with a vacuum source, and also hold the parts during the friction welding operation may be used.
Alternatively, the invention may be useful in connection with a device such as that disclosed in U.S. Pat. No. 3,708,376 wherein a pedestal assembly for accurately receiving and positively capturing a lower thermoplastic container half when it is being transferred in to and rotated by a spin welding apparatus is disclosed. The spin welding apparatus frictionally joins the lower container half to an upper container half to form a unitary container. The lower container half is received by the pedestal assembly from a rotating star wheel transfer device which slides the lower container half onto a stage portion of the assembly. The pedestal assembly having the container half thereon is then rotated in an opposite direction from that of the star wheel transfer device. The pedestal assembly including the stage portion has a dome-shaped upper surface which cooperates with a complementary recessed bottom of the lower container half. Vacuum means are applied through a central opening in the pedestal assembly for aiding in the positive capture of the lower container half.
Other devices where the present invention may find applicability are disclosed in U.S. Pat. No. 3,216,874 to G. W. Brown; U.S. Pat. No. 3,220,908 to G. W. Brown et al; U.S. Pat. No. 3,316,135 to G. W. Brown et al; U.S. Pat. No. 3,499,068 to G. W. Brown; U.S. Pat. No. 3,607,581 to G. A. Adams; U.S. Pat. No. 3,669,809 to G. W. Brown; U.S. Pat. No. 3,701,708 to G. W. Brown et al; U.S. Pat. No. 3,708,376 to R. J. Mistarz et al; U.S. Pat. No. 3,726,748 to R. J. Mistarz et al; U.S. Pat. No. 3,726,749 to R. J. Mistarz et al; U.S. Pat. No. 3,744,212 to R. J. Mistarz et al and U.S. Pat. No. 3,847,014 to R. J. Mistarz. It will be appreciated by the artisan that the control system of the present invention and the method by which it operates can be adapted to other devices as well.
In general, during the spinwelding process, welds are produced by the stowage of kinetic energy in the driving tool. When the two functional surfaces to be welded are brought into intimate contact, the kinetic energy is dissipated in the form of heat, thus resulting in fusion or welding of the surfaces brought together.
For purposes of the description which follows, a defective weld is defined as a failure to create a bond of adequate strength, usually due to a failure of either a loss of one of the surfaces to be welded through, for instance, a missing component or an improper fit; or a mechanical failure of a driving tool or the driven position of one of the components to be welded.
The method and apparatus of the present invention is designed to detect excess rotation of a driving tool at a point in the spinweld process where the tool should be at rest.
In connection with known spinwelding devices, a need exists for accurately and instantly determining when a container weld is defective or when an accomplished container weld has fractured. In addition, there is a need to identify and remove any defective product such as a container so that it will not be utilized and its intended contents wasted. It is desirable to perform this operation accurately and automatically to maximize the production output of the overall system. In addition, it is both necessary and desirable to identify any particular piece of equipment wherein a large amount of defective containers are being produced to allow for remedial or protective action.
In addition, it is necessary to design a control system for an apparatus as noted above that can be retrofitted into existing equipment or incorporated in new units and which therefore uses a low voltage power source.
OBJECTS AND SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a method and apparatus for controlling friction welding machines.
It is a further object of the present invention to provide a method and apparatus for determining when a thermoplastic weld is defective.
It is a further object of the invention to provide a method and apparatus for removing or ejecting products with defective welds.
It is still a further object of the present invention to provide a method and apparatus for determining when a particular unit is producing an excessive number of defective products and then identifying the equipment problem or automatically shutting the unit off.
In addition, it is still a further object of the present invention to provide a control device which may be retrofitted onto existing equipment.
To achieve the foregoing and other objects and in accordance with the present invention, as embodied and broadly described herein, the method and apparatus of this invention may comprise either a single spindle system in which the invention would preferably operate on a time basis following weld initiation, or a multiple spindle application wherein the system would preferably scan the product at a fixed point in the machine's rotation position and then alarm and/or reject any defective product.
The more complex multiple spindle embodiment would, in accordance with the present invention, comprise a means for detecting if a tool or spindle is live, i.e. turning at a position after a weld should have been accomplished and the spindle be at rest, thus indicating a defective weld has occurred. When a live spindle is detected, a mechanical "flag", a light or an alarm may be used to identify the station having the defective product.
Preferably, a mechanical flag is used which can also preferably be used to actuate the defective product eject mechanism which senses the presence of the flag and energizes an eject mechanism.
Preferably, the mechanical flag may be a metal member which is raised by a solonoid type device such as an air cylinder. The raised flag will be sensed by a proximity detector, preferably a Hall type sensor which will then, in a multiple spindle arrangement, preferably actuate a timing circuit which will time the point at which the defective product passes an ejection station which will remove the defective product from the production system.
Preferably the system will also include a means for determining the number of defective products attributable to each piece of equipment and if the number of defective welds becomes excessive, an automatic maintenance notice and/or system shutdown is effected.
Additional objects, advantages and novel features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and form a part of the specification, illustrate several embodiments of the present invention and, together with the description, serve to explain the principles of the invention. In the drawings:
FIG. 1 is a perspective view of a machine for dispensing upper and lower plastic container halves from nested stacks thereof which may be used with the sytem of the invention, joining these container halves together to make containers, filling the containers, and affixing caps onto the tops of the containers.
FIG. 2 is a somewhat diagrammatic plan view of the machine of FIG. 1.
FIG. 3 is a vertical cross-sectional view through the spinwelding unit of the machine of FIGS. 1 and 2.
FIG. 4 is a block diagram of the live spindle inspection system in accordance with the present invention.
FIG. 5 is a block diagram of the defective product rejection system in accordance with the present invention.
FIG. 6 is a block diagram of the live spindle detection of FIG. 4.
FIG. 7 is a block diagram of the flag set timer of FIG. 4.
FIG. 8 is a timing chart of the system of FIGS. 4 and 5.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
It will be helpful at the outset to describe generally the overall construction and operation of a spinwelding machine with which the present invention may be used. It should be understood that the details of the spinwelding machine described below are exemplary only and the detection/ejection system of the present invention may be used with other machines as well. One such machine is illustrated in FIGS. 1, 2, and 3. This machine assembles plastic containers with bulk supplies of nested container halves, fills the containers, and caps and seals the open tops of the filled containers.
The containers are assembled from separately fabricated container top halves 4 and container bottom halves 6, with the two halves of each container being frictionally welded together at the middle of the container.
The machine is in the form of a base or table structure 8 carrying hereon a control panel 10, a series of processing units and means for transferring the container portions to and from the various processing units. The processing units and the transfer means are driven by intermeshing gears corresponding in location to the configuration shown in FIG. 2. Preferably, a single drive unit may be employed to impart rotational movement to each drive gear and to each corresponding processing unit and transfer means. Also, the pitch line circles of the intermeshing gear drives preferably are in alignment with the circles formed by joining the centerlines of the container halves and the containers as they travel throughout the system. The processing units are all rotatable units, and transfers between units are accomplished through rotating star wheels, permitting the compact and efficient arrangement indicated in FIG. 1 of the drawings.
The upper and lower container halves 4 and 6, respectively, are delivered from the star wheel device 18 into alignment with the center lines of an upper cylindrical mandrel 150 and a lower cylindrical mandrel 152. The mandrels are mounted for movement in a circular path about the central axis of the spin welder 32 (FIG. 3). The transfer takes place at an angular zone where the star wheel periphery moves into a position of tangency to the path followed by the several upper and lower mandrels. This transfer is assisted by conventional stationary guide rails 154 as illustrated in FIG. 2. The end portions of the guide rails 154 intersect the path of the container halves on the star wheel 18 and cause the container halves to move onto the mandrels rather than permitting them to continue to move about the axis of the star wheel.
The star wheel device 18 includes upper and lower generally circular plates 156 having general semicircular, even circumferentially spaced cutouts 118 at their peripheries for engaging the outer peripheries of the container halves 4 and 6. The cutout portions of the upper and lower plates are superposed and the pairs of superposed cutout zones comprise carrier stations of the star wheel device 18. The plates 156 are carried by a shaft 158 extending through a stationary cylindrical member 160 and being connected at its lower end portion to a drive gear 39. This shaft 158 is journalled within bearing means carried by the frame or table 8 and indicated generally at 161 in FIG. 3.
The spin welder drive gear 43 is attached to a hollow drive shaft 166 extending upwardly about the center of the spin welder unit 32. This hollow shaft is rotatable about bearing means 168, 170, and 172 which are located between a stationary vertical shaft 174 and the hollow drive shaft 166.
At its upper end the center stationary shaft 174 supports a stationary vacuum supply means generally indicated at 176 and an annular cam track 178. The platform 8 also has a part thereof a vacuum supply shown generaly at 180 and an annular cam track 182. The detailed operation wherein the cam tracks 178 and 182 are used will be subsequently described.
It would be helpful at this point to describe generally the spin welding operation to form a basis for the detailed description which follows. The container halves, once aligned with the center lines of the upper and lower spindles or mandrels 150 and 152, are surrounded by the spindles for subsequent spinning. The spindles rotate about the central axis of the spin welder 32 and also move vertically toward each other when surrounding the container halves. The lower spindle 152 which surround the bottom half additionally rotates about its own axis during the spinning operation. Once the container halves are frictionally welded, the spindles are caused to separate and free the surrounded joined container.
Each of the spindles is moved vertically on a shaft which is stationary with respect to its own axis but which revolves about the central axis of the spin welder unit 32. The shafts for the upper mandrels 150 are designated 184 and the shafts for the lower spindles 152 are designated 186. Each upper spindle shaft 184 extends downwardly from a support member 188, and each lower spindle shaft 186 extends upwardly from a support member 190. These support members 188 and 190 are carried by main rotating shaft 166 at the center of the spin welder, so that the spindle shafts 184 and 186 revolve about the central axis of the spin welder 32. The rotational movement of the shafts 184 and 186 about the spin welder central axis causes the spindles 150 and 152 to rotate therewith.
Vertical movements of the spindles with respect to their shafts 184 and 186 are achieved by means of connecting rods 192 and 194 operatively connected to the spindles 150 and 152, respectively. These connecting rods have cam followers cooperating with the previously mentioned stationary cam tracks to vertically position the upper and lower spindles as they rotate about the central axis of the spin welder 32. The upper connecting rod 192 has cam follower 196 thereon for traveling within the stationary upper cam track 178. The lower connecting rod 194 also has a cam follower 198 associated therewith for movement within the lower cam track 182.
Each lower spindle 152 is additionally capable of spinning about the axis of its shaft 186 when a pulley area 200 thereof is brought into contact with the spin welder driving belt 34 (FIG. 2) during a predetermined number of degrees of the rotation of the mandrel about the central axis of the spin welder 32. For this purpose, bearing means (not shown) are interposed between each spindle 152 and its shaft 186.
The upper vacuum supply indicated generally at 176 is suitably connected to a vacuum port which feeds to the periphery of a central opening (not shown) within the upper mandrel. The shape of this opening conforms generally to the shape of the upper container half 4. The vacuum is applied about the outer periphery of the container half 4 when it is being surrounded by the upper spindle 150.
Turning now to FIG. 4, there is depicted a block diagram of the live tool inspection system of the present invention. Each driving spindle, for instance 152 in FIG. 3, is equipped with an optical scan bar 221 positioned around its circumference. This scan bar consists of a series of reflective (222) and non-reflective (223) bars or surfaces that produce a series of reflective impulses when the spindle or mandrel 152 is rotated. In addition, a proximity probe 201, such as that available from Peico Electric Eye, Model No. RLS, is used to sense the proximity of a timing marker on a multiple spindle machine. The probe may be a Hall effect type device and will emit a single pulse of for instance 5-10 ms duration each time the shaft 166 (FIG. 3) rotates; see FIG. 8, time chart A. The probe 201 functions as a logic probe to turn on the system in sequence with the arrival of the first container at the scan point. Thus, previous empty tools or spindles are ignored. Once probe 201 turns the system on, the reflective electric eye 202 scans each passing tool to determine if it is rotating. An excess of rotation, determined as described herein below, causes electric eye 202 to emit an output pulse for each reflective bar 222 that rotates past its field of view.
An electric eye 202, such as that available from Peico Electric Eye, Model PDR may be used for this purpose. The emitter/detector system will preferably consist of a frequency modulated infrared emitter/detector system (219, 220) to prevent cross talk with other electric eyes in the system. In any event, the emitter/detector system must have a very fast response time.
A live spindle detector, 203 receives the pulses from the electric eye 202, shown in FIG. 8, time chart B, and compares the total number of pulses received with a preset digital register. If the number of pulses received is below a preset register set point, no output is generated by detector 203. If the number of pulses exceeds a predetermined set point, the detector 203 will emit a single pulse of relatively short duration, for example on the order of 10 ms; see FIG. 8, time chart C.
For the detector 203, a detector such as that available from Vercon, Inc., Model No. DK-128, may be used. As best seen in FIG. 6, the detector may preferably comprise of a trigger latch circuit 224, a decade counter 225 and a one shot 226. The trigger latch circuit 224 functions in a manner similar to an SCR. Upon receipt of the initial trigger signal from probe 201, the trigger/latch circuit 224 will energize the control system (which is powered from a 12 v DC bus) and also automatically clear the decade counter 225 so that it starts each spindle rotation count at zero.
With regard to the decade counter 225, it is programmed so that if its pulse count from electric eye 202 exceeds a predetermined level, for instance on the order of approximately six, it will generate an output. The reason a threshold level is used before an output will be generated is to provide for the typical situation of a spindle or tool going past the field of view of the electric eye 220 wherein typically, several reflective surfaces, 222, will be in the field of view of the electric eye 220. A predetermined count on the order of about six is chosen to discriminate between the situation where the tool is live (is rotating) and where it is at rest but the reflecting surfaces 222 are transmitting to the emitter/detector as they move into its field of vision.
If the pulse count in the decade counter 225 from emitter/detector 202 exceeds the threshold level, it therefore means that for some reason the tool or spindle is not at rest and that the weld is defective or has otherwise not been accomplished. A defect or malfunction signal is thereby generated by the one shot 226 which may be a Quad 2 logic chip with an RC timing network. The one shot 226, on receiving a signal from the decade counter 225 that the threshold pulse count has been exceeded, emits a pulse of approximately 10 ms duration indicating a "live" tool or spindle condition (i.e. defective weld).
In the multiple-spindle embodiment, whether or the not decade counter 225 accumulates a pulse count in excess of the threshold value while a particular spindle is before it, a reset signal (see FIG. 8, time chart F) is generated by the passing of another spindle into proximity with the electronic eye. This reset signal is generated by detector 204 which is similar to detector 201 except that it is actuated by each of the weld station spindles or tools. This logic probe or reset probe produces one (approximately 5 ms) pulse at the conclusion of the scan cycle of each weld station tool. This resets the digital register or decade counter 225 of the live spindle detector 203 to zero. Thus, each weld station spindle is scanned individually. In other words, assuming a multiple spindle embodiment having for example 14 spindles, the detector 204 would generate fourteen reset signals for counter/register 225 during each 360° revolution of the machine, while the sensor 201 will only generate a single pulse during each revolution of the machine. The counter/register 225 is reset each time a weld station tool or spindle comes before it, regardless of whether a defect has been sensed.
When the one shot 226 produces a defective weld signal, it is received by the flag set timer 205 which may consist of an electronic time delay circuit; Circuit Model No. DK-126-A produced by Vercon, Inc. of Michigan, can be used for this purpose. This circuit is essentially an electronic time delay circuit which is triggered by a flying (i.e., non-clock or random) pulse and which will then execute its preset timing cycle automatically. At the conclusion of its timing cycle the flag set timer automatically resets.
As can best be seen from FIG. 7, the flag set timer 205 basically functions as a pulse stretcher and consists of a trigger board 227 and a NOR logic timing delay circuit. A pulse of approximately 10 ms duration is fed into trigger board 227 which instantly (less than 8 ms to output) outputs a signal from time delay circuit 228 until the circuit 228 times out; see FIG. 8, time chart D. The delay circuit 228, once triggered, will output a pulse for a preset period of time which is selected depending upon the speed of rotation of the machine and the number of spindles per machine; the time period being generally inversely proportional to the speed of rotation and the number of spindles.
The output from the circuit 228 is used to energize a solonoid 206 of a flag set unit 207; see FIG. 8, time chart E. The flag set unit may be either an electromagnetic or pneumatic device used to mechanically raise a flag indicator 209 directly associated with the defective product weld station. The mechanical flag or other optical, electrical, magnetic or audio indicator "informs" the machine and machine operator of the exact location of the defective product without further consideration of machine speed or container synchronization. The pneumatic finger 208 or similar element, when actuated, will trip a flag member 209 almost instantly and then retract, again almost instantly, so as not to trip the flag associated with the next weld station. It should be noted that when a flag member 209 has been tripped by the actuator 208, an operator looking at the machine will be able to visually determine at the point of exit, for instance the star wheel 40 of FIG. 2, the defectively welded products. The flag remains up until reset as described herein below.
There may be attached to the live tool detector 203 a live tool production lockout device 221 which essentially consists of a digital register or the like that receives any output pulse from the live tool detector 203. Each defective product produced updates the counter 221 by one. When a predetermined level of defects have been reached, the lockout device may automatically suspend further production by the machine and/or initiate a request for maintenance. The lockout counter/register may be a Vercon, Inc. Model No. DK-129 which can be connected to the DC logic power source and which will shut down the machine and/or call for maintenance if the accumulated number of rejected products exceeds a predetermined amount.
As depicted in FIG. 5, in order to eject a defective container, the invention provides a flag reader 212-214, an automatic ejection timer 215 and an ejector 216.
The flag reader eye may be a beam break device that senses the interruption of a light beam between a light source 212 and an electric eye or light sensor 213. The reader 212-214 is positioned at a point in the rotation of the machine to coincide with the defective product's exit point from the machine (see FIG. 2). The flag or similar device breaks the beam of the electric eye or similar device (i.e. magnetic, electrical or other type of optical sensor) thus producing a pulse of about 5 ms output, as shown in FIG. 8, time chart G. It should be noted that this type of "time position" arrangement places the system in perfect synchronization with the spin weld machine at all times thereby removing machine production speed as a factor in the overall accuracy of the system.
In order to reset the flag position when mechanical flags are used, a reset unit comprising a roller 210 to contact the flag and a stationary finger 211. It should be understood that this unit is only exemplary for the mechanical flag embodiment, and other reset devices would be employed for other types of defect indicators. The indicator is not reset into its original position until after it passes light source 212 and light sensor 213.
The output pulse from the flag reader 214 is received by an auto ejector timer 215 which initiates a preset timing cycle (similar to the manner described herein above with regard to the flag set timer 205) as depicted in FIG. 8, time chart H. At the conclusion of its timing cycle the automatic ejector timer will automatically reset. The automatic ejector timer may be a Vercon, Inc. Model DK-127-A. The "on" time of timer 215 is determined by the position of the defective product at the time its corresponding flag is sensed and by how much time is required to sweep the defective product off of its tool or spindle as described below.
The container ejector 230 is similar to the flag set unit 206-208 described herein above and may preferably be a solonoid actuated pneumatic device that functions under the direction of the timing cycle of the automatic ejector timer to remove a defective container at the outfeed of the device. The device 230 comprises a solonoid 216, a pneumatic actuator 217 and an element, preferably a pneumatic finger, 218 to eject the container from the machine, and is timed in accordance with the output of timer 215 as depicted in FIG. 8, time chart I.
The foregoing description of a preferred embodiment of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teaching. For example, the specific means to generate the timing pulses and the timing signals, the indicator, means and indicator reset means as well as the specific ejector means may, for example, all be modified within the skill of the art. The embodiment was chosen and described in order to best explain the principles of the invention and its practical application to thereby enable others skilled in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention is defined by the claims appended hereto.
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Disclosed is a method and apparatus for determining the quality of a spinweld bond produced on a single or multiple spindle production spinwelder and to a method and apparatus for alarming and/or ejecting products containing defective welds.
The method and apparatus of the present invention utilizes a detector means to determine the condition of a tool or spindle (i.e., if it is still "live" rotating at a point when it should be at rest) and a timing means to actuate an indicator when a live tool is detected. The present invention also involves a means to detect a spinwelder with an actuated indicator and to eject the product thereon. The present invention also relates to a method and apparatus for automatically shutting down a spinwelder producing an excess of defective products.
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RELATED APPLICATION DATA
This application is a continuation of application Ser. No. 14/284,611, filed on May 22, 2014, to issue as U.S. Pat. No. 9,428,986 on Aug. 30, 2016, and incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
The field of the invention is barrier plugs for use in subterranean locations for formation treatment and more particularly plugs that substantially disintegrate when the treatment has ended.
BACKGROUND OF THE INVENTION
In certain types of treatments such as fracturing, a series of barriers with ball seats are used for the purpose of sequentially isolating intervals that have already been fractured so that the next interval uphole can be perforated and fractured. Typical of such plug devices is Us2013/0000914. Here sleeves are expanded that have an external seal and a lower end ball seat. At the end of the fracturing operation all the sleeves that were used have to be milled out.
US 2014/0014339 shows the use of a plug with an external rubber seal that is expanded with a swage moved by a wireline setting tool where the swage has a ball seat and is made of a disintegrating material. The design uses a shear device to the setting tool mandrel that remains behind as well as a rubber sleeve.
U.S. Pat. No. 7,784,797 shows the use of hardened insert segments with square bases that are dropped into an associated recess and then overlaid with rubber to retain the insert for running in. On setting, the hardened particles emerge through the rubber to aid in fixation of the expanded liner hanger. This being a liner hanger installation there is no need for any components to later disintegrate.
Several features are included in the present invention such as the use of degradable ribs without any seals for a fracturing application. While the ribs alone may not create a perfect seal on expansion and may not penetrate the surrounding tubular, a fracturing application can tolerate some leakage as long as the required flow can be delivered at the needed pressure to the formation. Additionally hardened materials, while having a benefit to enhance wall penetration into the surrounding tubular for enhanced grip are still limited in their degree of expansion and are not materials that are degradable. This can then leave residue when degrading other parts of a fracturing plug. The design of the shear tab from the fracturing plug is such that it extends into a mandrel of the setting tool that is removed from the plug when using a wireline setting tool such as the E-4 setting tool offered by Baker Hughes Incorporated of Houston, Tex.
An alternative design features the use of flexing ribs that do not necessarily penetrate the wall of the surrounding tubular but that can be made of a disintegrating material. These are combined with an o-ring seal to minimize the non-degrading parts when the plug is no longer needed and has to be removed to facilitate other completion steps or production. Hardened inserts are provided at a spaced location from the o-ring. The inserts can be in the shape of a c-ring and spread and snapped in or using flexing of an adjacent rib inserted as discrete units to be retained with a potential energy force from the adjacent flexed rib. While the hardened inserts and the o-rings do not disintegrate the bulk of the plug will disintegrate facilitating subsequent operations. These and other aspects of the present invention will be more readily apparent to those skilled in the art from a review of the description of the preferred embodiment and the associated drawings while recognizing that the full scope of the invention is to be determined from the appended claims.
SUMMARY OF THE INVENTION
A disintegrating plug uses a setting tool to push a swage into the plug body that has external ribs that contact the wall of the surrounding tubular. The ribs retain the body to the surrounding tubular wall with frictional contact. Some leakage may ensue but in fracturing some leakage does not matter if enough volume under the right pressure reaches the formation. The sheared member during the setting comes out with the mandrel that is part of the setting tool. In an alternative embodiment one or more o-rings are used to seal while anchoring is assisted by the hardened insert(s) that can be snap fitted in using rib flexing or that can be a c-ring that is expanded and snapped in. The o-ring(s) are axially spaced from the insert(s).
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a half section view of an embodiment using disintegrating ribs that friction grip with no seal;
FIG. 2 is an alternative embodiment with o-ring(s) seal and hardened inserts that snap in with a c-ring shape or are pressed in with an interference fit from rib flexing.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a setting sleeve 20 and a mandrel 22 that are part of a wireline setting tool that is not shown. The mandrel 22 supports the plug 24 due to tab 26 being positioned on shoulder 28 and retained there by bushing 30 which is further retained by set screw 32 . During the setting the wireline setting tool such as an E-4 made by Baker Hughes Incorporated of Houston, Tex. pushes down on sleeve 20 while pulling up on mandrel 22 so that the cone 34 ramps out the top end 36 of the plug 24 . Near the top end 36 are a series of ribs 38 made preferably from a disintegrating material when exposed to certain well conditions or fluids. One such material is a controlled electrolytic material or CEM as described in US Publication 2011/0136707 and related applications filed the same day. The related applications are incorporated by reference herein as though fully set forth. As a result when the proper conditions are obtained the plug 24 will fully disintegrate as it constituent components such as the cone 34 and it body now missing tab 26 that was sheared off when the plug 24 was set and the mandrel 22 removed from the plug 24 are now all made from the disintegrating material. It should be noted that the lower end 40 of the cone 34 will come to a stop before or at travel stop 42 . The use of the disintegrating material for the creation of the ribs allows the points 44 of the ribs 38 to move out radially into contact with the surrounding tubular that is not shown. In applications such as fracturing an absolute seal is not required as long as enough volume under the needed pressure gets delivered to the formation. While the points 44 do not necessarily penetrate the surrounding tubular and when made of a disintegrating material will most likely provide a friction grip, the advantage of the use of the disintegrating material is that there is no well residue when the disintegration is initiated because the entirety of the plug is from a disintegrating material. Contrary to the prevalent though of those skilled in the art, hardened materials that penetrate the surrounding tubular are not required particularly if the treatment is fracturing because some leakage is tolerable while the fracturing gets done. The number of ribs 38 may be increased for additional grip. The use of the disintegrating material also makes the expansion easier and requires less force with a reduced chance for cracking due to overexpansion.
Additionally, the configuration of the plug 24 is such that on setting the tab 26 is sheared off and removed with the mandrel 22 when the running tool that is not shown is actuated to set the plug 24 and removed from the borehole. As a result, the embodiment of the plug 24 that is made of a fully disintegrating material results in complete removal after the plug 24 has served its purpose as a barrier. Beyond that a piece of the body of the plug 24 in the form of tab 26 has already been sheared off. It should be noted that the top of the cone 34 has a formed seat for an object such as a ball for isolation. With the mandrel 22 removed during the expansion that sets the plug 24 the seat 45 is exposed to accept an object such as a ball that is not shown. The cone 34 defines a drift dimension through the plug in the set position.
FIG. 2 shows an alternative embodiment that differs from FIG. 1 in the sense that there is an o-ring 4 in an associated groove that is designed to engage the surrounding tubular that is not shown. Unlike the consensus in the past designs that provided a long rubber sleeve that was secured to the plug body, the present design dispenses with building up a wide rubber sleeve and putting ribs within the rubber or at opposed ends for an extrusion barrier. In the present design, it has been determined that one or more o-rings 4 in respective grooves on the plug body 8 will provide adequate sealing in applications such as fracturing where liquid tightness is not mandatory as long as there is enough pressure retention that allows the desired volume at the desired pressure to get into the formation to fracture the formation. While the o-ring(s) 8 do not disintegrate when the treatment with the plug body 8 is completed the other plug components can be made of a disintegrating material such as CEM so they can disintegrate when needed. In an option for the design with the o-ring 8 there can also be hardened inserts that can take the form of discrete segments or a split ring that can be snapped over the body 8 . The segments form of the inserts 6 can be forced in an interference fit using elastic flexing of a nearby rib 50 . On the other hand when using a c-ring shape for the insert 6 there is the availability of the potential energy in the snap ring that is initially flexed and then released into an associated groove. Such a groove can be formed with an adjacent rib such as 50 to get the combined effect of the potential energy in the ring and the interference fit from the flexing rib. While the hardened insert(s) 6 penetrate the surrounding tubular wall for enhanced grip they also do not disintegrate after use so that there is some residue from removal of the plug body 8 and the cone 2 . As with the FIG. 1 embodiment, the setting process involves pushing with setting sleeve 12 and pulling the mandrel 10 . As before when that happens the tab 52 is sheared off and taken out with the mandrel 10 . While a single o-ring 4 and a single hardened insert 6 are shown multiple rows can also be used with the understanding that more material will not disintegrate at the end of the treatment procedure. The insert 6 can be carbide or polycrystalline diamond and it is designed to penetrate the surrounding tubular that is not shown for a grip. The points 54 of the ribs 50 do not penetrate the surrounding tubular and in this embodiment it is not even necessary that they even engage the surrounding tubular. This is because the anchoring is accomplished substantially by the insert(s) 6 . As before the shoulder 56 can act as a travel stop but it is more likely that the cone 2 will stop well before reaching shoulder 56 as the inserts 6 penetrate the surrounding tubular. Tab 52 is retained by retaining nut 14 that is further held on with a set screw 16 .
Those skilled in the art will appreciate that the illustrated plug designs can be used for treating operations at a subterranean location such as fracturing, injection, acidizing or conditioning the formation for production among other uses. In the FIG. 1 embodiment the plug is fully disintegrating after use as it is made from disintegrating materials that respond to well conditions created after use so that no residue remains for the subsequent operations or to injure other equipment that is in the vicinity. The plug can permit some leakage and still be useful for operations like fracturing even with a plurality of ribs that friction grab the surrounding tubular rather than penetrating the surrounding tubular. Additional anchoring can be obtained with adding more ribs but it has been determined that hardened inserts are not mandatory for functionality in fracturing service. An elongated rubber seal is also not needed if some leakage flow is tolerated. The advantage is the full disintegrating capability of a plug made from such materials in its entirety. On the other hand, FIG. 2 represents a design that leaves some but a minimal amount of residue while the balance of the plug disintegrates after use. It uses a spaced apart o-ring from a hardened insert. The use of one or more o-rings leaves less residue than larger rubber sleeves that had been used before to not only secure the inserts in position but to also give what was then thought to be the needed sealing area. As it turns out, one or more o-rings can give the needed or adequate sealing capability even if some leakage ensues from tubular out of roundness. The inserts are secured with an interference fit or a snap action independently of the o-rings. Rather than anchoring with a friction fit with rib tips as in the FIG. 1 embodiment, the FIG. 2 design uses the hardened inserts to penetrate the surrounding tubular so that the rib tips can either add the friction force for anchoring or simply not even contact the surrounding tubular. On the other hand when it comes time to disintegrate the plug there will be some residue to contend with since the carbide or diamond nature of the inserts will not disintegrate and neither will the rubber of the o-ring seals. However, at least 80% of the volume of the plug will disintegrate making the FIG. 2 design a more practical compromise design for some applications where very high pressure differentials are expected or where some leakage is also not tolerated as well. In both cases the cone has a seat for an object that is exposed when the plug is set and the setting mandrel comes out bringing with it the sheared tab from the plug body.
The above description is illustrative of the preferred embodiment and many modifications may be made by those skilled in the art without departing from the invention whose scope is to be determined from the literal and equivalent scope of the claims below:
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A disintegrating plug uses a setting tool to push a swage into the plug body that has external ribs that contact the wall of the surrounding tubular. The ribs retain the body to the surrounding tubular wall with frictional contact. Some leakage may ensue but in fracturing some leakage does not matter if enough volume under the right pressure reaches the formation. The sheared member during the setting comes out with the mandrel that is part of the setting tool. In an alternative embodiment one or more o-rings are used to seal while anchoring is assisted by the hardened insert(s) that can be snap fitted in using rib flexing or that can be a c-ring that is expanded and snapped in. The o-ring(s) are axially spaced from the insert(s).
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This application claims the benefit of U.S. Provisional Application No. 60/091,109 filed Jun. 29, 1998, entitled “ A Method of Hop - By - Hop Routing In Multiprotocol Networks With Overlaid Routing Domains ,” which is incorporated herein by reference.
FIELD OF THE INVENTION
This invention relates to communication networks, and more particularly, to hop-by-hop routing in which different network nodes have different views of the network topology.
BACKGROUND OF THE INVENTION
Networks are the principal means of exchanging or transferring information, which may be in the form of data, voice, text, video and the like, among different communication devices connected to the network(s), including I/O devices such as computer terminals, multimedia workstations, fax machines, printers, servers, telephones, videophones, and the like. A network typically comprises switching nodes connected to each other and to communication devices by communication links. Each link is characterized by link capacity, available bandwidth, link propagation delay, processing delay at the associated node, delay variation, and loss probability, among other things. Such characteristics are referred to as “metrics,” with some remaining constant, and others varying over time. Information input from the communication devices to the network may be in any form, but is often formatted into packets of either fixed or variable length. When information is to be exchanged between two communication devices, a path is established within the network connecting the nodes (called a source node and destination node) with which those devices are associated.
In many networks, a given communications stream between a specified source and destination is carried over a set of physical paths (i.e., paths comprising the source and destination nodes, and possibly one or more intermediate nodes, and communication links connecting the included nodes) within the network. An important element of network design is the process of selecting a set of physical paths for routing information through the network. This process may take into account various factors, such as network topology, currently available network resources, and quality of service (QoS) commitments made to network users, e.g., guaranteed bandwidth or maximum packet delay, among others. To support path selection, different network nodes maintain information about the network, including node adjacency and link incidence, reachability of different nodes, as well as various other link metrics. This information is stored in a so-called “topology database” of the node and constitutes the node's view of the network.
The routing of information packets from a source node to any other node in the network or a segment of the network, in which all nodes have the same view of the network topology is well established. Two existing routing paradigms in such networks are source routing and hop-by-hop routing. In source routing, the entire route taken by a packet from source to destination may be pre-computed and placed on the packet. As the packet is passed from the first node to a second node, the second node strips its address from the pre-specified route and passes the packet to the next node indicated in the packet header. In the alternative routing technique of hop-by-hop routing, no pre-computed route is employed. Each packet contains only the destination address. Upon receiving a packet, each intermediate node refers to its routing table, computed on the basis of its topology database, to forward the packet along the next hop towards the destination node.
Well-known methods, such as Dijkstra's shortest path algorithm, have been developed, which given the single static view of the network, determine under fairly general conditions the shortest routing path between any two network nodes. However, if different network nodes have different views of the network topology, such algorithms cannot guarantee loop-free and effective routing.
Recently, the focus in network routing has shifted, however, toward dynamic or state-adaptive routing. Beside reducing configuration work, such routing adapts quickly to changes in the available resources of the network and link failures. Several design solutions exist for dynamic routing in computer networks and are still under development, with distance vector and link-state protocol approaches being the ones well-known.
The basic idea of link state routing protocols is that each node sends local network topology information to its neighbors. This information is then propagated through the network using sophisticated “flooding” mechanisms. As the result, every node accumulates the view of the entire network in its topology database. The generation and flooding of information is repeated each time a node sees a significant change in available local resources. The distributed pieces of topology information, link state up-dates (LSU) or link state elements (LSE), carry a unique identifier and a version number increasing when the information inside of such an LSU is changing. Additionally, to prevent this process from being triggered too often, a dampening function controls the thresholds holding back non-significant changes. The topology database resulting from the execution of this latter “flooding” mechanism between nodes is used to compute routes to the desired destinations. Such routes are used, for example, in hop-by-hop forwarding of packets. The distance vector approach is based on a significantly different idea. Each node continuously diffuses information about the distances to different network sites reachable via that node. At the same time, it uses data received from other nodes and metrics of its own links to recompute the set of best routes, thus updating the distance information it distributes.
Despite the simplicity of the latter protocols, they are plagued by problems, such as long convergence times, forming of loops and lack of scalability in terms of topology sizes supported. Research is being performed to alleviate some of the problems. It should be noted that these link-state protocols also suffer from excessive amount of information being flooded in larger topologies. Therefore, newer link-state routing protocols incorporate a concept of “hierarchy,” where a part of the network running a link-state protocol collapses into a logical node in the view of distant nodes, and between such logical nodes, sometimes called areas, where some form of distance vector protocol is being executed.
Modern routing protocols, such as PNNI, are following the trend toward extensibility for future requirements, which abandon fixed packet formats and use TLV (type, length, value)—encoded packet schemes. The “type” describes the fixed part of the TLV transmitted and the “length” indicates the offset in the packet where the next TLV starts. In cases where the length exceeds the length of the fixed part of the TLV, embedded TLVs are present. Generally, TLV encoded packets transferring topology information in modern routing protocols can be interpreted as representations of lists of arbitrary elements embedded themselves in a recursive fashion into lists at a higher level.
An additional property of many of the prior art routing protocols is their ability to flood information elements even if they are opaque to the receiver since their type is not known. This allows newer protocol versions to be introduced as well as experimental features in an existing network to be deployed without the necessity of bringing all the nodes synchronously to the same release. To operate properly, guaranteeing packet delivery to the destination without creating loops, the link-state and distance vector protocols require that the topology databases of different network nodes converge to the same view of the network. In the networks deployed so far, however, different versions of link-state protocols cannot interoperate when new metrics or novel link properties are introduced, unless a translation between them is performed. Furthermore, network topologies are traditionally partitioned into disjoint domains corresponding to different routing protocols due to the possibility of loop creation.
SUMMARY OF THE INVENTION
The present invention presents a method to effect hop-by-hop routing in a network segment where different nodes have different views of the network topology. In particular, the methods of this invention are applicable when each node in a network or network segment may be aware of only a subset of the communication links in the network, without perceiving other communication links. Based on each node's individual view of the network, the method introduces the concept of a visibility set that includes all visible communication links. A network segment may contain an ordered hierarchy of such visibility sets and each visibility set may contain a subset of all communication links in the network segment.
In general, an efficient algorithm is disclosed for searching for a family of one-to-all optimal feasible paths in a communication network where different nodes may have different views of the network topology. Generally, the invention comprises the following steps:
(a) restricting the set of available paths to a destination node to the set of feasible paths from the source node to the destination node; and
(b) choosing as the optimal route the feasible path which has the lowest cost, wherein a path is a feasible path if (i) the path does not contain a cycle, and (ii) for each intermediate node visited by the path, the subpath from that intermediate node to the destination node is visible from the intermediate node.
The invention ensures that forwarding a packet along an optimal feasible path guarantees its eventual delivery to the destination node without being dropped or being routed to the same node twice. The present method provides for the execution of multiple dynamic routing protocols, possibly overlaying each other in the same address space, within a network with common kinds of metrics of arbitrary complexity. It also solves the problem of interoperability when new metrics or novel link properties are being introduced and eliminates the necessity to run different protocols and protocol versions within disjoint routing domains.
BRIEF DESCRIPTION OF THE DRAWINGS
The features and advantages of the present invention will become more readily apparent from the following detailed description of the invention in which:
FIG. 1 illustrates routing with incomplete information; (a) shows a hypothetical sample graph, and (b)-(e) show visibility sets shared by the corresponding shaded vertices;
FIG. 2 illustrates how routing along a non-optimal feasible path may create a cycle;
FIG. 3 illustrates embedded visibility sets; (a) shows a sample graph with three classes of vertices distinguished by the density of shading, and (b)-(d) shows the visibility sets for each class and formal definitions;
FIGS. 4 ( a )-( c ) illustrate the topologies induced by the three visibility sets (a) 1 ; (b) 2 and (c) 3 , respectively;
FIG. 5 illustrates a graph for demonstrating the probabilistic advantage of forwarding a packet to a knowledgeable neighbor when no feasible path exists;
FIG. 6 is a flowchart of the feasible path algorithm employed in the present invention;
FIG. 7 is a flowchart of a so-called “modified Dijkstra algorithm” of FIG. 6; and
FIG. 8 shows the operation of the feasible path algorithm on the sample graph of FIG. 4, with capital letters denoting the identification of the vertex, italicized numbers denoting edge weights, and bold numbers denoting tentative distances from the source A.
DETAILED DESCRIPTION OF THE INVENTION
The following detailed description of the inventive method is divided into the following sections. Section I, after introducing the basic definitions and describing the network communication model, formalizes the problem of routing in overlaid domains by considering the perceived cost of paths and nodes' visibility sets. Section I then defines the notion of a feasible path and proceeds by defining the routing policy rules which are necessary and sufficient for successful routing under general visibility conditions, as well as formulating the criterion of path feasibility in the particularly important case of embedded visibility sets. Section II specifies the algorithm searching for optimal feasible paths and proves its correctness. Several applications of immediate practical importance are considered in Section III, followed by the discussion of longer term perspectives in Section IV.
I DEFINITIONS AND INTRODUCTION TO THE MODEL
A. Model Description
Let a computer communication network be modeled by a directed graph G=(V, E), where the vertices in set V represent the switching/routing nodes and the edges in E correspond to unidirectional communication links. Each edge e of the graph is assigned a unique weight w(e) from a cost class W representing some link configuration or state parameter, relevant to routing. In such a setting, the “length” of a link is most often not its true geometrical length, but can be a value representing any characteristic of that link. “Weight” will be used as the general term for such values, with the cost given by the sum of the weights, as set forth more fully herein below.
Although in many cases it is sufficient to think of the weight as a non-negative integer, we allow it to have a more complex structure. A cost class W could be any set which contains the elements, zero 0 and infinity ∞; is closed under a properly defined summation operation; and can be totally ordered with some “not worse than” relation. We refer to such set as an “abstract cost class.” To avoid confusion, the summation operation on the elements of W, which is referred to as formal addition, is denoted ⊕, whereas the notation ≦ is used for the ordering relation. As an example of a non-integer cost class, consider a system in which the available bandwidth is the primary routing criterion, while the number of hops is used as a tiebreaker. The corresponding cost class is a set of pairs (B, H), where B is real and H is an integer. The zero and infinity elements are represented by (∞,0) and (0,∞), respectively, and the definitions of formal addition and comparison are:
( b 1 ,h 1 )⊕( b 2 ,h 2 )=(min{ b 1 ,b 2 },h 1 +h 2 ),
( b 1 ,h 1 )≦( b 2 ,h 2 )⇄( b 1 >b 2 ) or ( b 1 =b 2 and h 1 ≦h 2 )
To ensure generality, we assume that relation established by E is reflexive, i.e., every node has a link to itself. Assume further that for any link e=(u,v)∈E, its weight w (e) is non-zero, if and only if vertices u and v are distinct.
B. Basic Definitions and Notation
A directed path π on graph G=(V, E) can be equivalently defined by a sequence of incident edges or by a sequence of adjacent vertices. A path is simple if it does not contain a cycle. A path containing no edges is called “degenerate” and is denoted φ.
Let π=(v 1 ,v 2 , . . . ,v n ). Any path π ij =(v i ,v i−1 , . . . ,v j ), such that 1≦i≦j≦n, is a “subpath” of π. In this case, π is an “extension” of π ij . If π′=(v n ,u 1 ,u 2 , . . . ,u m ), then ρ=(v 1 ,v 2 , . . . ,v n ,u 1 ,u 2 , . . . u m ) is a “concatenation” of π and π′.
Every subset of edges F ⊂ E defines a “partial graph” G F =(V,F). Let F′ be a reflexive closure of F. We will refer to the set of all directed paths in G′ F =(V,F′) as a “topology” induced by F. Edge subset F is a “base set” of topology . A non-degenerate path belongs to topology , if and only if all its edges are elements of the base set F. For any two vertices s and d in V, vertex d is “accessible” in F from s, if topology induced by F contains a path π=π(s,d) from s to d.
C. Cost of a Path and Visibility Sets
We are interested in modeling the situation when different nodes see the network differently. In particular, “a view” of some vertex v∈V can be completely specified by the set of “perceived weights” {w v (e)|e∈E} of all the edges. While perceived weights of the same edge may vary from vertex to vertex, the invariant value of w(e) will be referred to as the “proper weight” of an edge.
Definition 1 (Absolute cost) The absolute cost C(π) of a non-degenerate path π, such that π=(u 1 ,u 2 , . . . ,u n ), is a formal sum of the proper weights of all its edges: C ( π ) = ⊕ 1 ≤ i ≤ n w ( u i , u i + 1 ) ( 1 )
The absolute cost of a degenerate path is zero: C(φ)=0.
If in Eq. (1), the proper weights w are substituted by the perceived weights w v , we obtain the definition of the “perceived cost” C v (π) of the path. It follows immediately from these definitions that the cost of a concatenation of two paths is equal to a formal sum of the costs of these paths, and the cost of any subpath is not worse than the cost of the path itself. We restrict our attention to the case when each vertex either sees an edge with its proper weight or doesn't see it at all.
Definition 2 (Visibility set) For every v∈V, there exists a subset F v ⊂ E, such that: w v ( e ) = { w ( e ) , if e ∈ F v ∞ , otherwise ( 2 )
The subset F v ⊂ E is called the visibility set of v.
Without any loss of generality, we assume that all outgoing edges of vertex v belong to F v . We say that a path π “is visible from” v, if π belongs to the topology induced by the visibility set of v. The following fact, which characterizes our approach to visibility, follows immediately from the definitions of perceived cost and visibility set.
Theorem 1 The perceived cost of any given path is the same for all nodes for which the entire path is visible.
In the following presentation, C(π) denotes the absolute cost of path π invariant in the view of all nodes for which entire π is visible.
Definition 3 (Path optimality) Let (s,d) be a set of paths from s to d. Path π* is an optimal path in (s,d), if it is not worse than any other path in (s,d):
∀π∈ (s,d): C(π*)≦C(π) (3)
Clearly, the optimal path in any given set may not be unique.
Depending on the choice of set , different types of optimal paths can be obtained. If (s,d) is a subset of the topology induced by the edge set E, restricted to the paths from a given source s to a given destination d, then path π*(s,d) in Definition (3) is “absolutely optimal.” If is a similarly restricted subset of v , a topology induced by the v's visibility set, then π* is an “optimal visible path.”
D. Guaranteed Routing in the Network with General Visibility Sets
In a traditional setting, when the visibility sets of all nodes in the network (or part of the network) executing some link-state routing protocol are assumed to be identical, the routing process amounts to finding the optimal (shortest) path to the desired destinations in the entire network or subnetwork. Well-known methods, such as Dijkstra's shortest path algorithm, have been developed which allow to solve this problem efficiently under fairly general conditions. However, if the visibility set invariance assumption is relaxed, these algorithms can no longer guarantee loop-free and effective routing.
When a node makes a routing decision, it naturally considers only the paths that are visible from it. The best path among those, i.e., the optimal visible path, may differ from the absolutely optimal path if the latter is not visible from the node. Furthermore, forwarding a packet to the next node along the optimal visible path can guarantee neither that the packet will actually follow this path, nor even that the packet will eventually reach its destination.
The obvious reason is that, in general, the visibility set of any node receiving the packet “along the path” is different from that of the source. Therefore, this node may see a worse (or better) path to the destination or may not see a path at all. Consequently, it may deflect the packet from the path selected by the source or simply drop it. As an example, consider the routing of a packet from source node A to destination node G in a computer communication network represented by the graph of FIG. 1 ( a ), with the visibility sets shared by the corresponding shaded vertices depicted in (b)-(e). The absolutely optimal path from A to G is (ADG) having cost 2 . But since link (DG) does not belong to the A's visibility set, the path itself is not visible from A and, therefore, is not available for routing. Among the two visible paths, (ABEG) and (ACFG), path (ACFG) is clearly optimal having cost 12 , as opposed to cost 24 of path (ABEG). However, if the packet is forwarded along the optimal visible path, then C, who does not see any path to the destination at all, may simply discard the packet. Assume that A forwards the packet along the non-optimal visible path (ABEG). Node E, which receives the packet after two forwarding operations, does not know anything about its previous history, and searches for the path to the destination within its own visibility set. Again, if E selects the optimal visible path (EADG), then the packet is routed back to the source thus creating a loop. On the other hand, the selection of a non-optimal path (EDG) succeeds; node D receives the packet and forwards it to the destination via link (DG) which belongs to visibility sets of both E and D.
Our objective is to establish a routing policy, i.e., a set of rules each node has to comply in order to perform routing successfully in the network where distinct nodes may have different visibility sets.
In accordance with the principles of the invention, the first rule of the routing policy (RP 1 ) is postulated:
(RP 1 ) If the destination is not accessible in the visibility set of a given node, this node may drop the packet.
The decision to route a packet is “successful,” if the packet is eventually delivered to the destination without being dropped or routed to the same node twice. The routing decision made by some node is “guaranteed,” if this node is able to prove the decision to be successful, based on its limited information about the network, under the assumption that all the nodes follow the same routing policy rules. Rule (RP 1 ) implies that for a routing decision to be guaranteed, it is necessary to ensure that the destination is accessible, in the respective visibility set, from any other node that may receive the packet.
Definition 4 (Feasible path) A path from source to destination is feasible at the source, if:
(a) the path is simple, and
(b) for every node visited by the path, the subpath from that node to the destination is visible from that node.
Corollary 1 Any subpath of a feasible path is itself a feasible path.
Corollary 2 If path π=π (u,d) is feasible at u, and there exist a node s with an outgoing edge e=(s,u), such that π is visible from s, then an extension path π′=(s,u,d) is feasible at s.
Referring again to the sample graph of FIG. 1, observe that path (ABEG) is the only feasible path at source A, and paths (EDG) and (EG) are both feasible at E, among those (EDG) being optimal.
As the main result of this section, we formulate the second rule of the routing policy (RP 2 ) and prove the following theorem about it.
(RP 2 ) If there exists a feasible path from a given node to the destination, this node should forward the packet along a path which is optimal among all such feasible paths; otherwise the node should drop the packet.
Theorem 2 In a general network of nodes adherent to (RP 1 ), for any routing decision to be guaranteed, it is necessary and sufficient that every node also complies with (RP 2 ).
Proof. Necessity. We begin with showing that, if rule (RP 2 ) is violated by some node, then it is not possible to prove the success of a routing decision. Let there exist a node, referred hereto as the source, that does not comply with (RP 2 ). Without any loss of generality, assume that the destination is accessible in the source's visibility set. (If it was not the case, no routing decision could be possibly guaranteed, as the source could expect any node, to which the packet is forwarded, to drop it.)
If the source forwards the packet along a non-feasible path π, whether or not a feasible path exists, then, by the definition of feasibility, there exists a node u visited by π, such that the subpath π u , from u to the destination is not visible from u. Therefore, the destination is not necessarily accessible from node u in its visibility set and this node could drop the packet according to (RP 1 ).
Now consider the case where two feasible paths to the destination, π(s,d) and ρ(s,d), are visible from s. Let these paths differ in the first edge and let C(ρ)≦C(π), C(ρ)≠C(π). Assume the source forwards the packet along the non-optimal path π(s,d) as depicted in FIG. 2 . There could exist a node u visited by path π with an outgoing edge e=(u,s), such that path ρ(s,d) is visible from u and w(e)⊕C(ρ)≦C(π u (u,d)). Then by Corollary (2), the extended path ρ′=(u,s,d) is feasible at u, and C(ρ′)≦C(π u (u,d)), so that node u, compliant with (RP 2 ), would forward the packet back to s thus creating a loop.
Sufficiency. Let “source” be any node whose routing decision is assigned the first sequence number and prove the following statement by induction on the number of forwarding operations:
Lemma A node receiving the packet after n forwarding operations sees at least one feasible path to the destination and chooses such feasible path, that its cost is not worse than the cost of the original path chosen by the source.
Let π n * be the path chosen by the node u n , which receives the packet after n forwarding operations. For n=0, node u 0 is in fact source s itself, and the statement trivially holds. Assume π k * is feasible at u k and C(π k *)≦C(π 0 *). The packet is forwarded by u k to node u k−1 , which by definition of feasibility, sees the subpath of π k * from itself to destination. This subpath is feasible at u k+1 , by Corollary (1). Since π k+1 which is chosen by u k+1 according to (RP 2 ), is an optimal feasible path, it is not worse than the subpath of π k * and, therefore, not worse than π k * itself. Then by transitivity, C(π k+1 *)≦C(π 0 *), which completes the proof of the inductive step.
According to the Lemma, node u n , which receives the packet after n forwarding operations, sees at least one feasible path to destination. Since, by the premise of the Theorem, u n is compliant to (RP 2 ), it does not drop the packet, but forwards it along one of the available feasible paths. As the packet forwarding sequence can be restarted at any node, it is enough to show that the actual path taken by the packet does not contain a cycle at the source. To the contrary, assume that after n forwarding decisions, the packet is routed back to the source: u n =u 0 =s. Accounting for the cost of the cycle, we obtain: C ( π 0 * ) = C ( π n * ) = C ( π 0 * ) ⊕ ( ⊕ 0 ≤ i < n - 1 w ( u i , u i + 1 ) )
which necessarily implies that, for all i, w(u i ,u i+1 )≡0. This is a contradiction with the definition of edge weights. Therefore, if all nodes comply with (RP 2 ) as well as (RP 1 ), no loop could be possibly created. It follows that under these rules, no edge is crossed more than once and, since the number of edges in the graph is finite, the packet eventually reaches destination.
Observe that the cost of the “actual route” taken by the packet, which is forwarded in compliance with the routing policy rules (RP 1 ) and (RP 2 ), lies between the costs of an absolutely optimal path and an optimal feasible path found at the source.
E. Embedded Visibility Sets
We now specialize for the case of “embedded” visibility sets. Let vertex set V be partitioned into K disjoint subsets V 1 , V 2 , . . . , V K . Each of the subsets V i is associated with a visibility set F i ⊂ E such that all nodes in V i share the same view of the graph. Furthermore, let the visibility sets be hierarchically related:
E=F 1 ⊃F 2 ⊃ . . . F K−1 ⊃F k (4)
As an example, consider the graph of FIG. 3 . The visibility sets of each of the three node classes are determined by the value of the edge weights: if some weight exceeds a class-specific threshold, the corresponding edge is not visible from the nodes of the class.
For convenience of presentation, let Γ(e) and Δ(e) denote the initial vertex and the terminal vertex of a directed edge e, respectively, and define the following operators:
Class (.) applies to a node and returns the index r of the subset V r to which the given node belongs;
View(.) applies to a node and returns the visibility set of the node: View(u)=F Class(u) ;
Vis (.) applies to an edge and returns the “visibility index” of the edge, i.e., the largest index of a visibility set in hierarchy Eq. (4) which includes the given edge:
( Vis ( e )= r )⇄( e∈F r and ( e∉F r−1 or r=K ))
For each vertex subset V i , 1≦i≦K and the visibility set F i , we define a corresponding topology i . The base set T i of topology i consists of all such edges in F i , whose initial vertex has a visibility set which includes F i :
T i ≡{e∈F i |F i ⊂View (Γ( e ))} (5)
Observe that for i=K, the base set of the topology coincides with the corresponding visibility set: T K =F K . For the sample graph presented above, the topologies induced by the visibility sets are shown in FIGS. 4 : ( a ) 1 ; ( b ) 2 ; ( c ) 3 ; and ( d ) 4 .
The following Theorem establishes the necessary and sufficient condition for a path to be feasible in the case of embedded visibility sets.
Theorem 3 (1) If source vertex u belongs to vertex subset V r ⊂V, which has visibility set F r satisfying hierarchy Eq. 4, and v∈V is some destination vertex, then all feasible paths from u to v can be represented as a concatenation:
π( u,v )=( t z *t z+1 * . . . t K *) (6)
where t i * is a (possibly degenerate) subpath in topology i with the base set T i constructed according to eq. (5), and z is the smallest visibility index among all edges in π(u,v):
r≦z =min e∈π(u,v) Vis( e )
(2) All simple paths of the form Eq. (6) are feasible at u.
Proof. (1) Use induction on the number n of edges in the path. First, let n=1. Consider a path containing single edge e=(u,v). This path is feasible by the premise of the Theorem. Therefore, e∈View (u) which implies that View (u) ⊃ F Vis(e) , as the opposite statement, e∈View (u)⊂F Vis(e) , contradicts the definition of the visibility index. It follows that e∈T Vis(e) , and the basis of induction is established.
Let the statement hold for a path π n =(u 1 ,v 1 ,v 2 , . . . v n ) containing n edges:
π n =( t z *t z+1 * . . . t K *)
where z≧r is the smallest visibility index achieved by some edge e in π n , and consider a feasible extension π n+1 =(s,u,v 1 ,v 2 , . . . v n ). By feasibility of π n+1 , e∈View(s) and View(s) ⊃ F Vis(e) =F z . Two cases are possible.
Case (a): Vis(s,u)≧Z. Then (s,u)∈F z belongs to the base set T z , so the subpath t z * can be extended to include link (s,u). The representation of eq. (6) holds for π n+1 with z unchanged.
Case (b): Vis(s,u)<z. Then by feasibility of π n+1 , (s,u)∈View(s) and View(s) ⊃ F Vis(s,u) . Therefore, (s,u)∈T Vis(s,u) . Concatenate representation for π n , to subpath t Vis(s,u) *=(s,u), complemented by (z−Vis(s,u)−1) degenerate subpaths. The result
π n+1 =( t Vis(s,u) *φ Vis(s,u)+1 . . . φ z−1 t z *t z+1 * . . . t K *)
is of the form Eq. (6) with Vis(s,u) being the smallest visibility index among the edges of π n+1 . The proof of the inductive step is completed.
(2) Let π(u, v) be a simple path which can be represented in the form of (6). Choose arbitrary edge e in π and find index of its subpath in this representation; let it be i. By construction of topology i ,
View (Γ( e )) ⊃ F i
Consider subpath ρ=ρ(Γ(e),v)of π(u,v) from the initial node of e to destination v. By assumption, every edge d in ρ belongs to the base set T j of some topology j , where i≦j≦K. By construction, Eq. (5), it necessarily belongs to the corresponding visibility set F j . Combining hierarchy eq.(4) with the results above, for any edge d of ρ, we obtain:
d∈F j ⊂ F i ⊂ View (Γ( e ))
Thus, for any vertex Γ(e) visited by path π(u,v), the subpath ρ=ρ(Γ(e), v) is visible from Γ(e). Path π(u,v) is feasible at u.
It follows from the Theorem 3 that in order to guarantee successful delivery in a general case, a node should drop the packet if no feasible path to destination exists. Note that, however, an attempt can be made to improve the probabilistic chances of the packet to be delivered to requested destination in the absence of feasible path while preserving the static no-loop guarantee. The sufficient condition of the packet discard could be relaxed as follows:
(RP 2 )′ A node should forward the packet along the path which is optimal among the feasible paths from that node to the destination, if such path exists. The node should drop the packet if and only if there exist no feasible path to the destination, and for all its outgoing edges, the terminal vertex of the edge belongs to the same or lower class of hierarchy (4) than the node itself. When no feasible path exists, but there is an outgoing edge, such that its terminal vertex belongs to the higher class of hierarchy, the node should forward the packet along such edge.
In a network of well-behaved nodes compliant with (RP 2 )′, the packet may not be forwarded back to the source neither as it passes up in the hierarchy, nor as it follows the feasible path discovered by some other node in the network; the latter case would imply existence of a feasible path from the source to destination. The loop-free property follows. The probabilistic advantage of rule (RP 2 )′ can be demonstrated using the graph on FIG. 5 . Node S does not see a feasible path to destination, because link (BC) is outside its visibility set, whereas its more knowledgeable neighbor A does see a feasible path and may forward the packet successfully.
However, in a well-behaved static network, a node should not have received a packet destined to an unreachable node, at the first place, and therefore not included with the proposed algorithm below, but not excluded from the principles of the invention.
II ALGORITHM
A. Specification
Referring to FIG. 6, discussed herein below is an algorithm applied to the case of embedded visibility sets of Eq. (4). It can be used to detect the existence of a feasible path from source s∈V r to any destination d∈V and, if such path exists, to compute the next hop of an optimal feasible path in accordance with principles of the invention.
The information about the network available to each node includes the membership of this node in the specific disjoint subset of nodes, the weights of the edges in its own visibility set along with the edge membership in the visibility sets of the lower hierarchical levels. Given this incomplete information, at step 600 , the source node first initializes the distance vector to infinity and then iteratively runs a variation of a shortest path algorithm or modified Dijkstra algorithm at step 610 on the gradually expanding partial graph. A flowchart for the modified Dijkstra algorithm of the present invention is set forth in FIG. 7 .
In the specification of the proposed algorithm, we make use of the following notation:
r is the index of the vertex set partition to which the source (i.e., node running the algorithm) belongs;
k is the total number of partitions of the vertex set;
{V i , i=1 . . . k} is a collection of vertex set partitions;
{F i , i=r . . . k} is a collection of visibility sets of partitions on the same or lower hierarchical levels than that of the source;
{w(e),e∈F r } is the set of perceived weights of edges in the visibility set of the source;
dist[ 1 :N] is a vector of tentative distances to all nodes in the network, i.e., the costs of the best feasible paths from the source to the respective vertex v∈V found so far;
next_hop[ 1 :N] is a vector of initial edges of the feasible paths leading to respective nodes in the network;
candidates and next_candidates are the ordered sets of vertices; sorting is performed in increasing order of the tentative cost of the feasible paths from the source to the respective vertex, in respect to relation ≦. Three operations on the ordered sets are available in the shortest path algorithm for the modified Dijkstra algorithm of FIG. 7 :
1. insert(set, v): insert node v into a proper position in set, in the increasing order of the dist vector;
2. update(set,v): change position of node v in set using the modified value of dist[v], so that the increasing order of dist is maintained;
3. remove(set): remove and return the first element of set.
Each node in the network maintains two vectors: vector dist [ 1 :N] of distances to all other nodes in the network computed along the corresponding optimal feasible path, and vector next_hop[ 1 :N] of initial links of those paths. When a packet destined to v is received at some node, it checks if the locally maintained value of dist[v] is finite. If it is the case, this node forwards the packet along the link specified by next_hop[v]. Otherwise, it drops the packet reporting the destination as unreachable. Alternatively, the implementation may attempt to improve the probabilistic chances of the packet to be delivered to the requested destination, while preserving the no-loop guarantee, by forwarding it to an adjacent node belonging to a higher class of hierarchy and having larger visibility set. However, in a well-behaved network when a routing protocol has converged to a stable state, a node should not have received a packet destined to an unreachable destination in the first place. Therefore, we do not consider this possibility further. To maintain dist [ 1 :N] and next_hop [ 1 :N] current, each node recomputes them either periodically or each time a significant change in link state parameters is detected.
Initially, in step 600 of FIG. 6 the source s sets to infinity all entries of the distance vector except its own, which is set to zero. Next, a set of communication links visible from the source node is chosen in step 710 . For any edge (i.e., communication link) in this visibility set (step 730 ), the entry corresponding to the source node in the distance vector is computed or updated, if necessary, as shown in steps 740 and 760 . Next, the node entry in the next hop vector corresponding to the source node is computed, as shown in step 750 . These steps are repeated until all the edges in the visibility set being considered are exhausted. Next, a new visibility set is considered in step 710 and the entries in the distance and next hop vectors are again updated for all nodes in this visibility set. This is repeated until all visibility sets are considered, as in steps 770 , 780 . This completes execution of the modified Dijkstra shortest path algorithm for the network.
Listed hereto as an appendix is the pseudo-code for the procedure feasible_path ( ) of FIG. 6, which is used to update the local data structures for the proposed routing method of the present invention.
B. Example
The operation of the algorithm on our sample graph of FIG. 3 is illustrated on FIG. 8 . At the initialization stage (FIG. 8 ( a )), the source A sets to infinity all entries of the distance vector (except its own, which is initialized to zero), and keeps the entries of the next-hop vector undefined. At Step 1 (FIG. 8 ( b )), the shortest path algorithm is executed on the topology i associated with the visibility set of the source. As a result, the vertices accessible from the source in this topology, namely, B,C,D,E,F, and J, acquire finite distances, and the initial links of their corresponding feasible paths are now defined. Notice that after Step 1 , the set of feasible paths forms a tree. It should be emphasized, that this set is shown on FIG. 8 ( b ) for reference purposes only; the actual data maintained by the source can be found in Table I.
At Step 2 (FIG. 8 ( c )), the candidates set initially contains those and only those vertices that, have finite tentative distances at the end of Step 1 . Removal of vertices from the candidates set occurs in the increasing order of their tentative distances and only those edges are considered by the shortest path algorithm which belong to the base set T 2 of topology 2 (see FIG. 8 ( b )). The first to be removed is vertex A which has no outgoing edges in T 2 . It is followed by vertex B, whose tentative distance is 16, which adds links (BC) and (BE), causing a change in the distance vector: dist[C]=28 and dist[E]=22, and redirecting next_hop[C] from link (AC) towards link (AB). Next, vertex is E is removed adding link (EH) which completes a feasible path to vertex H, so that dist [H] becomes 34, etc. Notice that from Step 2 on, the set of feasible paths no longer forms a tree: the tentatively optimal feasible path from source A to vertex F is (ABCF), whereas for vertex J it is (ACFJ).
At the beginning of Step 3 , the candidates set is re-initialized again to contain vertices A, B, C, D, E, F, H, J, and the operation is repeated, but this time only edges in the base set T 3 of topology 3 are considered. The distances of vertices F and D are reduced, due to discovery of feasible paths (ABEHF) and (ABEHFD), while vertices G and L are reached for the first time. Vertex K remains unreachable, since it does not have incoming edges in 3 . At this point the algorithm terminates, yielding the costs and identities of initial links of optimal feasible paths to all vertices, except K (FIG. 8 ( d )). Overall, the maximum number of times each edge is considered equals to the number of topologies this edge belongs to.
TABLE I
EVOLUTION OF LOCAL DATA STRUCTURES IN THE COURSE OF
EXECUTION OF PROCEDURE feasible_path() AT SOURCE VERTEX
A. ENTRY FORMAT: dist[v]/next_hop[v]; ‘*’: undefined; ‘-’: LOCAL.
Vrtx
Init.
Step 1
Step 2
Step 3
A
0/-
0/-
0/-
0/-
B
∞/*
16/(AB)
16/(AB)
16/(AB)
C
∞/*
36/(AC)
28/(AB)
28/(AB)
D
∞/*
50/(AD)
48/(AB)
38/(AB)
E
∞/*
70/(AC)
22(AB)
22/(AB)
F
∞/*
54/(AC)
46/(AB)
36/(AB)
G
∞/*
∞/*
∞/*
44/(AB)
H
∞/*
∞/*
34(AB)
34/(AB)
J
∞/*
78/(AC)
78/(AC)
78/(AC)
K
∞/*
∞/*
∞/*
∞/*
L
∞/*
∞/*
∞/*
42/(AB)
C. Correctness
Based upon the teachings of the present invention, those skilled in the art will readily note that the proposed procedure is based on a variation of the well-known Dijkstra's shortest path algorithm applied repeatedly to a partial graph which is expanded according to the established rules set forth above. The correctness properties of Dijkstra's algorithm in the broader context of the different shortest path problems are analyzed in the prior art, as well as the proof of its finiteness and the discussion of its implementation strategies.
In its original form, Dijkstra's algorithm operates on a graph with non-negative integer edge weights and constructs a shortest path tree by scanning the vertices in the increasing order of their tentative distances from the start vertex. This is performed by labeling the outgoing edges of each scanned vertex, i.e., updating the distances and the tree pointers, if an edge under consideration creates a shorter path to its terminal vertex than all those found before. The variation of Dijkstra's algorithm employed above does not build a tree, maintaining a vector of initial links of the shortest paths instead, requires several iterations, and works with link weights of arbitrary structure. We will refer to this inventive variation as the Generalized Dijkstra's algorithm.
Let a pass of procedure feasible_path( ) be an iteration of the outermost while-loop.
Lemma If there exist a path π(s,v) from source s to some vertex v∈V which can be represented in the form of concatenation.
π( s,v )=( t r *t r+1 * . . . t r+n−1 ) (7)
where t i * is a subpath in topology i , then after n passes of procedure feasible_path( ), dist[v] is equal to the cost of a path which is optimal among all paths from s to v allowing representation (7), and next_hop[v] points to the initial link of such a path. If no path allowing representation (7) exists, then after n passes dist[v]=∞ whereas next_hop[v] remains undefined.
Observe that the first pass of the procedure is equivalent to running Generalized Dijkstra's algorithm on topology r , induced by the visibility set of the source s. Consequently, all optimal paths found by the algorithm belong to r . By virtue of using a variation of Dijkstra's algorithm, the resulting value of dist[v] is equal to the cost of the shortest (i.e., optimal) path from in s to v in topology r , if in this topology v is accessible from s, and remains infinite otherwise. In the same time, the resulting value of next_hop[v] points to the initial edge of such path, if one exists, otherwise remaining undefined. This establishes the basis of induction.
Let dist (n) [v] and next_hop (n) [v] be the local vector entries, corresponding to node v, after n passes of procedure feasible_path( ). Extend set E by fake edges f v from the source s to each vertex v∈V, whose weights are defined as w(f v )=dist (n) [v]. By assumption, w(f v ) is finite if and only if there exist a path π(s,v) from s to v representable in the form (7) and, furthermore, in that case w(f v ) is equal to the cost of an optimal one among such paths. Consider an augmented graph
G n+1 =( V,T r+n ∪{f v =( s,v )}) (8)
By construction of procedure feasible_path( ) and definition (5), the (n+1)-th pass of the procedure is equivalent to running Generalized Dijkstra's algorithm on the augmented graph (8) initializing it to the state when all fake edges emanating from the source vertex, and only those edges, have already been labeled. If for some vertex v, the original graph G=(V,E) contains a path π(s,v) from s to v of the form
π( s,v )=( t r *t r+1 . . . t r+n−1 *) (9)
with u being the terminal vertex of subpath
π( s,v )=( t r *t r+1 *t r+n−1 )
then the edge set of the augmented graph (8) contains a fake edge f u =(s,u), such that w(f u )≠∞. By definition, it also contains all edges T r+n . Then, by virtue of running a variation of Dijkstra's algorithm on the augmented graph, dist (n+1) [v] is finite and equal to the cost of an optimal path among those which can be represented as a concatenation of some fake edge f u and a subpath belonging to topology r+n . Recall that each fake edge in fact corresponds to an optimal path of the form (7). Therefore, dist (n−1) [v] is equal to the cost of an optimal path of the form (9). The value of next_hop (n+1) [v] in this case either coincides with next_hop (n) [u], if s≠u, or points to the initial edge of an optimal path (φ r . . . φ r+n−1 t r+n *), otherwise.
Finally, since all paths considered by Generalized Dijkstra's algorithm running on the augmented graph are concatenations of some fake edge f u and a subpath in topology r+n , the finite value of dist (n+1) [v] would imply existence of a path represented as (9). If no such path exists, the resulting value of dist (n+1) [v] is necessarily infinite with corresponding next_hop (n+1) [v] undefined. This concludes the proof of the Lemma.
Combining the statement of this Lemma with the necessary and sufficient condition of Theorem 3 proves the following
Theorem 4 (Correctness) When procedure feasible_path( ) executing at node s terminates, dist[v] is equal to the cost of an optimal feasible path from s to v and next_hop[v] points to the initial link of such a path. If no feasible path exists, then upon termination, dist[v]=∞ whereas next_hop[v] remains undefined.
III APPLICATIONS
After completing the discussion of the theoretical background and the algorithmic part, we now focus on the practical applications of the proposed routing method. The examples given below should simplify the understanding of the theoretical discourse and demonstrate how the theory can be applied to the deployment and operation of routing protocols.
A. Mapping to Existing Networks
The directed graph model is a traditional abstraction of a communication network. As in most link-state routing protocols, it operates with a notion of an abstract node, attached to other nodes by virtual links. Each bidirectional communication link, as commonly and expectedly encountered in today's networks, is mapped onto a pair of unidirectional edges of the graph with possibly different weights w(e) corresponding to link-state parameters in the respective directions. Although presently the non-negative integer weights are predominant, the advent of QoS routing schemes strongly motivates the protocol generalizations which are capable to operate with link-state parameters of the more complex structure. With this aspect in mind, it is easy to see the equivalence of the shortest path and the optimal path concepts. Traditionally, the shortest paths are computed using a centralized, distributed or replicated version of appropriate algorithms with an underlying topology distribution mechanism, a functional conglomerate known as “routing protocol.”
The novelty of the proposed approach manifests itself in the fact that we do not assume that the routing protocols are running, “invisible” to each other, on disjoint parts of the network's topology. Neither do we imply that such separation is taking place by abstracting paths computed by an “underlying” routing protocol as virtual topology. Instead, we allow the protocols to overlap or contain each other's topologies. We assume such information to be “hierarchically” visible within multiple protocols or, expressed differently, that the protocols are “integrated.” This concept is formalized with a notion of a visibility set: each node v is able to see only a subset F v of the communication link set E. Disregarding aggregation issues, a traditional routing protocol assumes that all nodes in the protocol's routing domain share the same visibility set. We show that this is not necessary and hop-by-hop forwarding can be utilized within protocols which abandon this assumption. We do not consider the problem of assuring the specified routing policies (RP 1 and RP 2 ) in general, but concentrate on the more practical case of embedded visibility sets. The partition of V into disjoint subsets, V 1 , . . . , V n , can be viewed as partitioning of the network into multiple routing domains, each running a different routing protocol or a different version of the same protocol with its own visibility set. The visibility sets of these domains do not have to be disjoint. On the contrary, it is assumed that they may overlap or be included within each other. The concept of topology i , as introduced here, defines what can be naturally characterized as a trusted subset of a visibility set, i.e., the topology is built only on those links of the visibility set which are advertised by the nodes having the same or larger view of the network. In other words, while planning a route within the same topology, the source can expect that its original decision won't be changed unless the node, which changes it, has more information about the network than the source itself.
B. Example of Two Topologies
Assume that every unidirectional communication link in a network is assigned a weight w(e)∈W, and a restricted link weight space W′⊂W is defined. The set E of all links can be partitioned into two disjoint subsets E′ and E″ based on the fact whether or not the value of the corresponding link state parameter belongs to the restricted space W′. Assume further that nodes of two types, referred to as “blue” and “red,” are present in the network imposing a partition of the vertex set V into two disjoint subsets V B and V R . The blue nodes observe only those links whose link weights belong to a restricted set W′ and ignore all others (i.e., view them as if their weight was infinite). The red nodes observe all the links in the network with their actual weight.
We introduce two topologies, blue topology B and red topology R , by defining their corresponding base sets T B and T R as follows:
T B ={e∈E|w ( e )∈ W′}
T R ={e∈E|e =( u,v ), u∈V R }
Note that an edge emanating from a red vertex and thus belonging to the red topology at the same time may or may not belong to the blue topology depending on whether or not its weight comes from a restricted space W′.
If the method proposed herein is used, then every blue node naturally searches for the best route to a requested destination among the paths which contain only links with the weights in the restricted set W′. On the other hand, every red node considers as possible candidates all paths which can be represented as a concatenation of two subpaths: red and blue.
C. Transparent Routing Protocol Upgrade
Modern routing protocols such as IS-IS, PNNI and BGP are designed in a way that allows newer protocol versions to transparently pass information through older nodes. The particular mechanism employed is the convention that information elements are encoded as TLV (type, length, value)-triplets and all nodes are obliged to pass such elements even with a type unknown to them to their neighbors possibly taking into account the semantics of some globally known flags per TLV as well. A similar mechanism exists in distance- or path-vector protocols such as BGP. These mechanisms allow for upgrades with newer protocol releases without having to force all devices to execute the same version at a given point in time. However, when new metrics or link properties are introduced during a protocol upgrade, they may only translate partially into the old metrics. A method has not been known to operate two such versions of a protocol in an arbitrary, mixed topology and assure loop-free hop-by-hop forwarding in presence of new and old metrics. The described method allows to run both versions and utilize either metric to forward traffic if they are comparable. This holds under the assumption that the visibility set of the newer protocol version embeds the visibility set of the older one, which is natural if backward compatibility is maintained. Additionally, the newer version has to generate both, new and old information elements for the links on which the metric is still within the old range to assure that the old protocol includes new links within its visibility set as long as possible. Even when a link has purely “new” properties that are not visible to the old nodes, they are still obliged to pass the information, therefore allowing two partitions of the network executing the new protocol version to coordinate their visibility sets.
D. Overlaying Multiple Routing Protocols
Today, routing devices within a data communication network rely mostly on a specific interface running a single routing protocol exclusively and to allow for global reachability by exchanging routes across protocols. The present routing method described herein allows to run multiple routing protocols on the same interface as long as their metrics are comparable and forward along the path with a better cost. This makes a magnitude of novel approaches towards network design possible. It is achievable to design a network running two routing protocols overlaid on top of each other, thus taking advantage of their different properties, e.g., one protocol can provide a fast convergence whether the other protocol can compute slowly optimal paths over the same topology. Such a design could increase robustness of the network, since it helps to avoid possible instability conditions and implementation problems within a single protocol, at an expense of additional bandwidth consumption. A precondition is of course that those protocols do not export routing information into each other and the necessary embedding of visibility sets is guaranteed.
IV CONCLUSIONS
Based on the observation that dynamic routing protocols traditionally restrict possible topological configurations during the deployment of newer versions and their operation in case of intersecting or overlaid domains is not well understood, we introduce a general methodology that formalizes the necessary conditions that have to be met to assure loop-freeness in such scenarios. Additionally, we present a novel algorithm that allows correct hop-by-hop forwarding within a network containing arbitrary mix of nodes running different protocol versions. The same algorithm introduces the possibility to overlap different routing domain as well, still assuring loop-free operation.
We expect the algorithm to prove useful in deployment of new versions of link-state routing protocols, which are still undergoing rapid changes. Missing capabilities, such as QoS support and ongoing development that necessitates new protocol versions can make use of the algorithm presented. Finally, a largely unexplored area is the possibility to run multiple routing protocols in an overlaid fashion to increase network stability or use different convergence algorithms and convergence properties to open new network design choices.
Many more variations of the preferred embodiment of the invention are possible without departing from the spirit, the essential criteria and the rules and methods of this invention. The proper scope of this invention is indicated by the appended claims, rather than by the foregoing description and all variations which come within the meaning and range of equivalency of the claims are therefore intended to be covered by the claims stated hereinafter.
APPENDIX
(1)
procedure feasible_path (r,k,{ V i , i = l ... k }
{ F i , i = r ... k },{ w(e),e ε F r },s)
(2)
var
(3)
dist [1:N] is vector of abstract cost;
(4)
next_hop [1:N] is vector of edges;
(5)
candidates is set of vertices;
(6)
next_candidates is set of vertices;
(7)
begin
(8)
for all ν ε i V i
(9)
dist [ν] := ∞;
(10)
end for
(11)
dist [s] := 0;
(12)
candidates := {s};
(13)
i := r;
(14)
while i ≦ k do
(15)
next_candidates := {};
(16)
while candidates ≠ {} do
(17)
ν := remove (candidates);
(18)
Ω: = { e ε F i | Γ(e) = ν and Class(ν) ≦ i};
(19)
for all e ε Ω
(20)
if dist[ν] ⊕ w(e) ≦ dist[Δ(e)] then
(21)
dist[ Δ(e)] := dist[ν] ⊕ w(e);
(22)
if ν = s then next_hop[Δ(e)] := e;
(23)
else next_hop[Δ(e)] := next_hop[ν];
(24)
endif
(25)
endif
(26)
if Δ(e) ∉ candidates then
(27)
insert (candidates, Δ(e));
(28)
else
(29)
update (candidates, Δ(e));
(30)
endif
(31)
end for
(32)
insert (next_candidates,ν);
(33)
end while
(2)
candidates := next_candidates;
(3)
i := i + 1;
(4)
end while
(5)
end feasible_path
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This invention relates to a method to effect hop-by-hop routing in a network segment where different nodes have different views of the network topology. In particular, the methods of this invention are applicable when each node in a network or network segment may be aware of only a subset of the communication links in the network, without perceiving other communication links. Based on each node's individual view of the network, the method introduces the concept of a visibility set that includes all visible communication links. More specifically, an efficient algorithm is disclosed for searching for a family of one-to-all optimal feasible paths in communication network where different nodes may have different views of the network topology. The algorithm comprises (a) restricting the set of available paths to a destination node to the set of feasible paths from the source node to the destination node; and choosing as the optimal route the feasible path which has the lowest cost, wherein a path is a feasible path if (i) the path does not contain a cycle, and (ii) for each intermediate node visited by the path, the subpath from that intermediate node to the destination node is visible from the intermediate node.
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BACKGROUND OF THE INVENTION
The present invention relates generally to a charge/discharge circuit for a discharge lamp which is particularly suitable for use in dry-type copiers. printers, facsimile machines and so forth as a fixation device and/or exposure device. More specifically, the invention relates to a power supply for the discharge lamp, which has improved charge/discharge characteristics for activating the discharge lamp.
Discharge lamps used in dry-type copier, printer, facsimile and so forth must have good charge characteristics. Conventionally, control of the charge characteristics of a discharge capacitor is hampered by the high voltage needed to trigger the discharge lamp to discharge energy therethrough.
At the same time, in order to improve fixation characteristics or exposure characteristics, it has been considered essential to control the discharge characteristics of the discharge lamp. In particular, control of the discharge period is very important to obtain the desired discharge energy for the required function.
Conventional charge/discharge circuits for discharge lamps have not been at all satisfactory with regard to precise control of the charge characteristics and/or discharge characteristics. In particular, when discharge lamps are employed for fixation of toner images in dry-type copiers and so forth, precise control of the charge and/or discharge period becomes essential to fixation quality.
SUMMARY OF THE INVENTION
Therefore, it is a principle object of the invention to provide a power supply circuit for a discharge lamp, the charge characteristics and/or discharge characteristics of which can be controlled in an improved manner.
Another and more specific object of the invention is to provide a power supply circuit for a discharge lamp, which can activate a discharge lamp by means of a discharge capacitor and which requires a relatively low voltage for charging the discharge capacitor within a period comparable or shorter than the charge period of conventional circuits.
A further object of the invention is to provide a power supply circuit for a discharge lamp which allows the discharge period to be set freely without degrading the activation characteristics of the discharge lamp.
A still further object of the invention is to provide a power supply circuit for a discharge lamp which enables precise control of the discharge period of the discharge lamp.
A yet further object of the invention is to provide a power supply circuit which is specifically adapted for use as a power supply for a discharge lamp in a fixation device for fixing a toner image, which power supply is controlled so as to improve fixation characteristics in order to obtain a high-quality of fixed toner image.
In order to acomplish the aforementioned and other objects, a power supply circuit, according to the present invention, comprises a single discharge capacitor having a charging sufficient to trigger discharge in a discharge lamp. The discharge capacitor is associated with means for accumulating energy, with which it is charged. The energy accumulating means receives commercially available alternating current and applies the accumulated energy to the discharge capacitor to charge the latter.
The power supply circuit may include an auxiliary capacitor which has a smaller capacitance and higher potential rating than the discharge capacitor. The auxiliary capacitor may have a potential rating sufficient to activate the discharge lamp alone. The discharge capacitor cooperates with the auxiliary capacitor to define discharge period.
Preferably, the power supply circuit may include means for blocking or shutting off power supply at a given timing to precisely control the discharge period. Such power supply blocking means is especially advantageous for controlling the quantity of light to be emitted by the discharge lamp.
In accordance with another feature of the invention, the discharge capacitor and the auxiliary capacitor are controlled so as to perform a two-stage flash which includes a first stage with a brief, relatively strong flash and a second stage with a longer, relatively weak flash. This flash is advantageous for fixing toner images with low- and high-toner-density components.
Alternatively, the discharge period may be controlled to within a given period to achieve good fixation of the toner image without causing significant noise or smell.
In accordance with one aspect of the invention, a power supply circuit for a discharge lamp comprises a primary charge current supply means for accumulating energy, a single primary discharge capacitor associated with the charge current supply means to receive the accumulated energy at a given timing to be charged, the discharge capacitor supplying power to the discharge lamp to cause emission of light upon discharging, and a trigger means, associated with the discharge lamp, for triggerng energization of the discharge lamp and discharge of the discharge capacitor and thereby causing emission of light by the discharge lamp.
The primary charge current supply means includes an alternating current source, accumulates energy while the alternating current is a first phase and supplies the accumulated energy to the primary discharge capacitor while the alternating current is a second, opposite phase. The charge current supply means includes a switching means responsive to zero-crossing of the alternating current to control accumulation and supply of energy.
The power supply circuit is associated with a secondary circuit including a secondary charge current supply means for accumulating energy and a secondary discharge capacitor connected in series to the primary discharge capacitor, the secondary discharge capacitor being associated with the secondary charge current supply means to be charged at a given timing with the energy accumulated by the secondary charge current supply means. The secondary charge current supply means includes an alternating current source, accumulates energy while the alternating current is a first phase and supplies the accumulated energy to the secondary discharge capacitor while the alternating current is a second, opposite phase.
The power supply circuit further comprises a second auxiliary capacitor of lower capacitance than the first primary capacitor, the second auxiliary capacitor being associated with the charge current supply means to be commonly charged with the first primary capacitor, and the potential of the second auxiliary capacitor being sufficiently high to energize the discharge lamp. The first primary and second auxiliary capacitor are charged by the charge current supply mean at different voltages. The charge current supply means comprises a flyback transformer.
The charge current supply means comprises a first component associated with the first primary capacitor for charging the latter and a second component associated with the second auxiliary capacitor for charging the latter, and the first and second components of the charge current supply means operating independently of each other.
Each of the first and second components comprises a flyback transformer.
The power supply circuit further comprises means for blocking power supply to the discharge lamp, the blocking means becoming active at a given timing. The blocking means is responsive to a timing signal generated when the time integral of the light flux emitted by the discharge lamp reaches a predetermined value. The blocking means comprises a capacitor charged by part of the power supplied to the discharge lamp and which discharges in response to the timing signal.
In the alternative. the power supply circuit further comprises a second auxiliary capacitor having a lower capacitance and a higher charge voltage than the first primary capacitance, the first primary and second auxiliary capacitors being discharged at different known times. The second auxiliary capacitor discharges prior to the first primary capacitor, thereby inducing brief, intense light emission by the discharge lamp, and subsequently inducing a weaker, longer emission by means of discharging the first primary capacitor.
The first primary capacitor discharges prior to the second auxiliary capacitor, thereby inducing a weak, prolonged light emission by the discharge lamp and subsequently inducing an intense, brief emission by means of discharging the second auxiliary capacitor.
The discharge period of the discharge lamp is in the range of 3 msec. to 9 msec.
In accordance with another aspect of the invention, a charge/discharge circuit for a discharge lamp comprises a charge current supply means supplying current at a known voltage for capacitor charging, a primary discharge capacitor associated with the charge current supply means to receive the current at a given timing and connected to the discharge lamp to supply power thereto so as to energize light emission thereby, a secondary discharge capacitor associated with the current supply means to receive current at a given timing and connected to the discharge lamp to supply power thereto, the secondary discharge capacitor having a lower capacitance and a higher potential than the primary discharge capacitor, which potential being sufficiently high to energize the discharge lamp, and a trigger means, associated with the discharge lamp, for triggering the discharge lamp and triggering discharge of the discharge capacitor and thereby triggering light emission by the discharge lamp.
The first primary and second auxiliary capacitors are charged by the current supply means at different voltages.
The current supply means comprises a flyback transformer.
In the alternative, the current supply means comprises a first component associated with the first primary capacitor for charging the latter and a second component associated with the second auxiliary capacitor for charging the latter, and the first and second components of the current supply means operating independently of each other. Each of the first and second components comprises a flyback transformer.
In accordance with a further aspect of the invention, a process for performing fixation of a toner image by means of discharge lamp comprising the steps of:
charging a capacitor means connected in series with the discharge lamp;
applying a trigger to the discharge lamp to cause discharge of the capacitor means and activation of the discharge lamp; and
discharging the capacitor means through the discharge lamp within a given period comprising a first period wherein a first predetermined quantity of light is emitted and a second period wherein a second predetermined quantity of light is emitted, the first and second periods coverng different lengths of time being and the first and second quantities of light different, and the second period following the first period.
The first period is relatively short and the first quantity of light is relatively large, and the second period is much longer than the first period and, the second quantity of light is much smaller than the first quantity of light. The first period is much longer than the second period and the first quantity of light is much smaller than the second.
The process further comprises a step of charging a first and a second capacitor in the capacitor means, which first capacitor has a larger capacitance and a longer discharge period than the second capacitor and a lower discharge voltage than the second capacitor, and the second capacitor discharges during the first period and the first capacitor discharges during the second period.
An alternative process comprises a step of charging a first and a second capacitor in the capacitor means, which first capacitor has a larger capacitance and a longer discharge period than the second capacitor and a lower discharge voltage than the second capacitor, and the second capacitor discharges during the first period and the first capacitor discharges during the second period.
The first and second capacitors are connected in series.
In accordance with a still further aspect of the invention, a process for performing fixation of a toner image by means of discharge lamp comprising the steps of:
charging a capacitor means connected in series with the discharge lamp;
applying a trigger to the discharge lamp to cause discharge of the capacitor means and activation of the discharge lamp; and
discharging energy through the discharge lamp over a period of from 3 msec. to 9 msec.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be understood more fully from the detailed description given herebelow and from the accompanying drawings of the preferred embodiment of the invention, which, however, should not be taken to limit the invention to the specific embodiments but are for explanation and understanding only.
In the drawings:
FIG. 1 is a schematic circuit diagram of the first embodiment of a power supply circuit for a discharge lamp according to the present invention;
FIG. 2 is a timing chart illustrating the charge and discharge operations of the power supply circuit of FIG. 1;
FIG. 3 is a schematic circuit diagram of a modification to the first embodiment of the power supply circuit of FIG. 1;
FIG. 4 is a timing chart illustrating the charge and discharge operations of the power supply circuit of FIG. 3;
FIGS. 5 and 6 are schematic circuit diagrams of modifications to the power supply circuit of FIG. 1;
FIG. 7 is a schematic circuit diagram of the second embodiment of a power supply circuit for a discharge lamp according to the present invention;
FIG. 8 is a timing chart illustrating the charge and discharge operations of the power supply circuit of FIG. 7;
FIG. 9 is a schematic circuit diagram of a modification of the second embodiment of the power supply circuit of FIG. 7;
FIG. 10 is a timing chart illustrating the charge and discharge operations of the power supply circuit of FIG. 9;
FIG. 11 is a schematic circuit diagram of the third embodiment of a power supply circuit for a discharge lamp according to the present invention;
FIG. 12 is a timing chart illustrating the charge and discharge operations of the power supply circuit of FIG. 11;
FIG. 13 is a schematic circuit diagram of the fourth embodiment of a power supply circuit for a discharge lamp according to the present invention;
FIG. 14 is a timing chart illustrating the charge and discharge operations of the power supply circuit of FIG. 13;
FIGS. 15, 16 and 17 are schematic circuit diagrams of modifications to the fourth embodiment of the power supply circuit of FIG. 13;
FIG. 18 is a timing chart illustrating the charge and discharge operations of the power supply circuit of FIG. 17;
FIG. 19 is a schematic circuit diagram of a further modification to the power supply circuit of FIG. 17.
FIG. 20 is a schematic circuit diagram of the fifth embodiment of a power supply circuit for a discharge lamp according to the present invention;
FIG. 21 is a graph of the discharge current versus time in the power supply circuit of FIG. 21;
FIGS. 22 and 23 are schematic circuit diagrams of modifications to the fifth embodiment of the power supply circuit of FIG. 20;
FIG. 24 is a graph of the discharge current in the power supply circuit of FIG. 23;
FIG. 25 is a schematic circuit diagram of the sixth embodiment of a power supply circuit for a discharge lamp according to the present invention;
FIG. 26 is a schematic circuit diagram of a modification to the power supply circuit of FIG. 25;
FIGS. 27 and 28 are graphs of the discharge characteristics of the power supply circuits of FIGS. 25 and 26, respectively;
FIGS. 29 and 30 are graphs of the discharge characteristics of the power supply circuits of FIGS. 5 and 13, respectively;
FIG. 31 is a perspective view of a flash fixation device according to the preferred embodiment of the invention; and
FIGS. 32(a) to 32(d) are graphs of the results of experiments performed on the device of FIG. 31.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, particularly to FIG. 1, a commercially available alternating current source 11 is connected to a coil 13 which has an inductance L. The collector-emitter path of an NPN transistor 12 is connected in a loop with the alternating current source 11 and the coil 13. A switch SW is connected to the base of the switching transistor 12 to turn the latter ON and OFF. As the transistor 12 is turned ON and OFF, the loop circuit is closed and opened respectively.
A capacitor 14 is connected in parallel to the coil 13. A diode 14 is connected between the coil 13 and the capacitor 15, with its anode electrode connected to the inductance coil and its cathode electrode connected to the capacitor 15.
A discharge lamp 16 is also connected in parallel to the capacitor 15 and associated with a trigger circuit which comprises a trigger coil 33, a trigger power source 34 and a trigger switch 35.
In this circuit, when the switch SW is closed in the positive phase period, i.e. during the period t 1 to t 2 of FIG. 2, the loop current I 1 illustrated in solid lines is generated. The waveform of the current flowing through the coil 13 during this period is shown in FIG. 2(C). The instantaneous electrical energy represented by the expression
1/2L I.sub.1.sup.2
thus appears at the inductance coil 13.
Then, the switch SW is opened again during negative phase period, e.g. during the period t 2 to t 3 , so that the current I 1 flowing through the aforementioned loop drops to zero, resulting in a reverse electromotive force. As a result, a flyback current I 2 , as illustrated in broken lines in FIGS. 1 and 2 flows through the coil 13, the diode 14, the capacitor 15 and as shown in FIG. 2(C). The flyback current I 2 drops to zero at a time t 2 '. At this time, the charge voltage across the capacitor 15 is maximized as shown in FIG. 2(D).
In other words, at time t 2 ' at which the flyback current I 2 drops to zero, the electrical energy in the coil 13 represented by the expression . . .
1/2L I.sub.0.sup.2
wherein I 0 represents the flyback current at the time t 2 ,
is transferred to the capacitor 15. This can be illustrated by the following equation:
1/2L I.sub.0.sup.2 =1/2C V.sub.0.sup.2 (1)
wherein C is the capacitance of the capacitor 15, and
V 0 is the voltage across the terminals at the time t 2 '.
It should be noted that, in the discussion, loss of electrical energy due to resistance in the electrical components and lead wires of the circuit and so forth is disregarded.
At time t 3 , the switch SW is again closed. The current I 1 again flows through the coil 13. As described above, electrical energy in the coil 13 is transferred to the capacitor 15 during the period t 4 to t 4 ' after the switch SW is opened again. Therefore, the electrical energy accumulated in the capacitor is doubled. Similarly, the voltage across the terminals of the capacitor 15 at time t 4 ' becomes √2 times as great as the voltage V 0 at the time t 2 '.
By repeating above operation over several cycles, at a time t 2n , the voltage between the terminals of the capacitor 15 becomes √n times greater than the voltage V 0 at the time t 2 '. When the capacitor voltage V 0 reaches a predetermined level, a high voltage is applied to a trigger electrode opposite the discharge lamp by the trigger coil 33.
According to the shown embodiment, since a single capacitor is intermittently charged instead of a plurality of mutually parallel capacitors, excessive input rush current can be successfully prevented, which prevents damage to the diode and/or leads due to overheating. In addition, according to the shown embodiment, the accumulated energy in the capacitor 15 can be held constant, so that secular variation of the characteristics of the capacitor, especially reduction of the capacitance of the capacitor, will not affect the discharge potential of the capacitor. For instance, if the capacitance C of the capacitor 15 should decrease due to secular variation, the voltage √nV 0 would increase to compensate for the reduction of the capacitance. Therefore, there will be no drop in the discharge energy which might affect the operating potential of the discharge lamp 16.
FIGS. 3 and 4 show a modification to the first embodiment of the power supply for the discharge lamp according to the present invention. This embodiment is designed to charge the capacitor in both half-cycles of the alternating current and thus to improve the charging efficiency of the capacitor. For this purpose, an additional coil 13', an additional switching transistor 12' and an additional capacitor 15' are provided. The capacitor 15' is connected in series to the capacitor 15.
As will be appreciated from FIGS. 3 and 4, this embodiment employs switches SW 1 and SW 2 to turn the switching transistors 12 and 12' ON and OFF. The switch SW 1 closes when the voltage of the alternating current increases across the zero-volt level and remains closed while the voltage V 1 remains positive. On the other hand, the switch SW 2 is designed to close when the voltage V 1 of the alternating current drop below zero volts and remains closed while the voltage V 1 remains negative. The closure timing of the switch SW 1 is substantially the same as that of the switch SW in the first embodiment of FIGS. 1 and 2.
Therefore, the charge operation and timing of the capacitor 15 is substantially same as that discussed with respect to FIGS. 1 and 2. Specifically, the capacitor 15 is charged at times t 2 ', t 4 '. . . . t 2n '. At the time t 2n ', the charge voltage on the capacitor 15 will be √nV 0 , as set forth above.
On the other hand, as shown in FIG. 4, the switch SW 2 is closed at the time t 2 , at which the voltage V 1 drops below zero volts. Closing the switch SW 2 renders, the transistor 12' conductive and so closes the circuit loop of the coil 13' and the transistor 12'. Therefore, a current I 1 ' flows through the coil 13. If the inductance of the coil 13' is same as that of the coil 13, the energy in the coil 13' will generally be equal to that in the coil over the period t 1 to t 2 .
The switch SW 2 is open while the voltage V 1 is positive. When the switch SW 2 opens, the transistors 12' turns OFF and so breaks the loop. As a result, a reverse electromotive force is induced in the coil 13', represented by the flyback current I 2 ' flowing through the capacitor 15' and the diode 14'. Therefore, the capacitor 15' is charged to the voltage V 0 at the time t 3 '. The charge level of the capacitor 15' reaches √nV 0 at a time t 2n +1' which is one half-cycle later than the timing t 2n .
Since the capacitors 15 and 15' are connected in series as set forth above, the potential applied to the discharge lamp is 2√nV 0 at time t 2n +1. Therefore, as will be naturally appreciated, the charging efficiency of the capacitors 15 and 15' is twice that of the first embodiment. In other words, in order to charge the capacitor to the necessary voltage level, this modification requires half the time of the first embodiment.
FIGS. 5 and 6 are modifications to the first embodiment. FIG. 5 is another modification of the first embodiment of FIGS. 1 and 2, and FIG. 6 is a further modification of the modifcation of FIGS. 3 and 4. In these modifications, flyback transformer or transformers 17 and 17' are employed as replacements for the coils 13 and 13'. The generation of potential in the flyback transformers 17 and 17' and transfer of the potential to the capacitors 15 and 15' are substantially the same as in the preceding embodiments.
FIG. 7 shows the second embodiment of the power supply for the discharge lamp according to the invention. FIG. 8 is a timing chart for the circuit of FIG. 7. In this embodiment, an auxiliary diode 21, a commutating capacitor 18, a main thyristor 19 and commutating thyristor 20. As shown in FIG. 8, the main thyristor 19 is turned ON in response to increase of the voltage V 1 of the alternating current from the commerical power source 11 across OV, and remains ON while the voltage V 1 remains positive. On the other hand, the commutating thyristor 20 is turned ON in response to negative-going zero-crossing of the voltage V 1 of the alternating current and remains ON for a given period of time.
According to the timing chart of FIG. 8, when the alternating current is supplied to the circuit set forth above, the main thyristor 19 turns ON in response to positive-going zero-crossing of the voltage V 1 of the alternating current, at a time T 1 . Current thus flows from the commercial power source 11, through the coil 13 and the main thyristor and back to the commercial power source 11. The current flowing through the coil 13 generates electrical energy as set out with respect to the first embodiment. At the same time, the current also flows through the commercial power source 11, the auxiliary diode 21, the commutating capacitor 18 and the main thyristor 19. Thus, the commutating capacitor 18 is charged to the peak value of the alternating current voltage. In this case, the terminal of the commutating capacitor connected to the auxiliary diode 21 will be the cathode.
After a half-cycle following time t 1 , i.e. at a time 2 , the main thyristor 19 is turned OFF and the commutating thyristor 20 turns ON in response to negative-going zero-crossing of the voltage V 1 . At this time, a reverse electromotive force is generated in the coil 13. The energy of the reverse electromotive force generated in the coil 13 is added to with the energy already stored in the commutating capacitor 18. The current flows from the commercial power source 11, through the coil 13, the commutating capacitor 18 and the commutating thyristor 20 and back to the commercial power source 11. At this time, the current flowing through the main thyristor 19 remains below a holding current of the main thyristor. Therefore, the main thyristor remains OFF.
At the same time, the current flows through the coil 13, the diode 14, and the capacitor 15 and returns to the coil 13. Therefore, the capacitor 15 is charged. The charge period is selected so that charging of the capacitor 15 is completed during the period while the voltage V 1 is negative. Thus, the capacitor 15 is charged to a voltage V 2 within one cycle of the alternating current.
As in the first embodiment, the capacitor 15 is charged repeatedly over several cycles of the alternating current until the charge on the capacitor 15 reaches V 2 . When the charge on the capacitor 15 become equal to or greater than the required voltage, the discharge lamp 16 flashes in response to a trigger voltage from the trigger coil 33.
FIGS. 9 and 10 show a modification the second embodiment of FIGS. 7 and 8. FIG. 9 is a schematic circuit diagram of the power circuit for a discharge lamp showing a modification to the circuit of FIG. 5, and FIG. 10 is a timing chart of operation of the circuit of FIG. 9. This modification is designed to charge the capacitors 15 and 15' at different phases of the alternating current of the commercial power source 11.
As will be appreciated from FIG. 9, the shown modification employs another set of a primary thyristor 19' and a commutating thyristor 20' in addition to the primary and commutating thyristors 19 and 20 of the embodiment of FIGS. 7 and 8. Also, an additional commutating capacitor 18' and auxiliary diode 21' are provided in the circuit. The main thyristor 19', the commutating thyristor 20', the commutating capacitor 18 and the auxiliary diode 21' are associated with another coil 13', another diode 14' and another capacitor 15' to form an auxiliary charge circuit which cooperates with a primary charge circuit consisting of the main thyristor 19, the commutating thyristor 20, the commutating capacitor 18, the auxiliary diode 21, the coil 13, the diode 14 and the capacitor 15.
As shown in FIG. 10, the main thyristor 19' is turned ON when the voltage V 1 of the alternating current from the commercial power source 11 drops below 0 V, and remains ON while the voltage V 1 remains negative. On the other hand, the commutating thyristor 20' is turned ON in response to a positive-going zero-crossing by the voltage V 1 of the alternating current and remains ON for a given period of time.
According to the timing chart of FIG. 10, when the alternating current is applied to the circuit described above, the circuit including the main thyristor 19, the commutating thyristor 20, the commutating capacitor 18 and the auxiliary diode 21 functions substantially the same as disclosed with respect to FIGS. 7 and 8. On the other hand, main thyristor 19' turns OFF in response to the positive-going zero-crossing of the voltage V 1 of the alternating current at time t 1 .
One half-cycle after time t 1 , i.e. at time 2 , the main thyristor 19' is turned ON while the commutating thyristor 20' remains OFF. The main thyristor 19' allows current to flow through the coil 13' and the main thyristor and back to the commercial power source 11. The current through the coil 13' generates electrical energy as explained with respect to the first embodiment. At the same time the current also flows through the commercial power source 11, the auxiliary diode 21', the commutating capacitor 18' and the main thyristor 19'. This current charges the commutating capacitor 18' to the peak value of the alternating current voltage. The terminal of the commutating capacitor connected to the auxiliary diode 21' is the cathode. Then, at a time t 3 one half-cycle after the time t 2 , the commutating thyristor 20' turns ON in response to the positive-going zero-crossing of the voltage V 1 . At this time, the reverse electromotive force from in the coil 13' is added to the energy already stored in the commutating capacitor 18'. Current then flows from the commercial power source 11, through the coil 13', the commutating capacitor 18' and the commutating thyristor 20' and back to the commercial power source 11. At this time, the current flowing through the main thyristor 19' is held below a holding current of the main thyristor. Therefore, the main thyristor remains.
At the same time, current flows from the coil 13', through the diode 14', and the capacitor 15' and back to the coil 13', thus charging the capacitor 15'. The charge period is selected so that the capacitor 15' is fully charged within the period during which the voltage V 1 remains negative. Thus, the capacitor 15' is charged to a voltage V 2 within one cycle of the alternating current.
As will be appreciated herefrom, as in the embodiment described with respect to FIGS. 5 and 6, the potential applied to the discharge lamp will be 2√nV 0 at time t 2n +1. Therefore, as will be naturally appreciated, the charging efficiency the capacitors 15 and 15' is twice as high as in the first embodiment. In other words, this modification requires half the time needed by the second embodiment to charge the capacitor at the necessary voltage level.
FIGS. 11 and 12 show the third embodiment of the power supply for the discharge lamp according to the invention. The shown circuit includes a switch SW which opens and closes depending upon the polarity of the alternating current from the commercial power source 11, which switch functions substantially the same as described with respect to the first embodiment. The circuit is also provided with diodes 30 a to 30 f , thyristors 31 a to 31 f and discharge capacitors 32 a to 32 a .
As shown in FIG. 12, during the first half-cycle (positive phase) of the altnerating current, the switch SW is closed and thus the switching transistor 12 in ON. During this period, the current from the commercial power source 11 flows through the coil 13 and transistor 12 and then back to the commercial power source. During this period, the energy is generated in the coil 13. When the phase of the alternating current from the commercial power source 11 goes negative, the switch SW is opened and thus the transistor 12 is turned OFF. Therefore, a reverse electromotive force is generated in the coil 13. At the same time, the thyristors 31 d , 31 e and 31 f are turned ON. At this time, the thyristors 31 a , 31 b and 31 c are held OFF. As a result, current flows through the coil 13, the diodes 30 c , 30 b and 30 a , the capacitor 32 a , and the thyristors 31 d , 31 e and 31 f and back to the coil 13. Therefore, the capacitors 32 a is charged during this period.
In response to a positive-going zero-crossing of the alternating current from the commercial power source in the second cycle, the switch SW again closes to turn ON the transistor 12. As a result, electrical energy is again built up in the coil 13. In response to the negative-going zero-crossing in the second cycle, the switch SW opened and thus the transistor 12 is turned OFF. Then, the thyristors 31 a , 31 e and 31 f turn ON. At this time, the thyristors 31 b , 31 c and 31 d are held OFF. Therefore, current flows from the coil 13 through the diodes 30 c , 30 b , the thyristor 31 a , the capacitor 32 b , diode 30 d and the thyristors 31 e and 31 f and back to the coil 13. Therefore, in the second cycle, the capacitor 32 b is charged.
Likewise, the capacitors 32 c and 32 d are charged respectively in the third and fourth cycles of the altnerating current. The capacitors 32 a , 32 b , 32 c and 32 d are all discharged after all of the capacitors have been charged. Therefore, in this embodiment, discharge can take place every 4 cycles of the alternating current. This discharge involves is the total of the potentials on the four capacitors, since the four capacitors are connected in series with the discharge lamp 16.
FIG. 13 shows the fourth embodiment of the power supply circuit for the discharge lamp according to the invention. FIG. 14 is a timing chart of the operation of the circuit of FIG. 13. In the shown embodiment, a discharge capacitor 15 is connected in series to an auxiliary capacitor 40. A rectifier 41 is connected in parallel with the auxiliary capacitor 40. The capacitor 40 and the rectifier 41 are connected to a terminal B of a secondary winding of a step-up transformer 42 through a rectifier 43, at terminals F remote from the discharge capacitor 15. On the other hand, the terminals F are connected to the negative electrode of the discharge lamp 16.
The discharge lamp 16 is, in turn, associated with the trigger transformer 33 which is responsive to a trigger from a trigger circuit. The trigger circuit comprises a trigger power source 34, a rectifier 36, a trigger capacitor 37 and a thyristor 38. A trigger pulse is applied from an appropriate external controller at an appropriate timing to the thyristor 38. The thyristor 38 turns ON in response to the trigger pulse. In response to turning ON of the thyristor 38, the trigger capacitor 37 discharges. As a result, current flows through the thyristor 37 and the primary winding of the trigger transformer 33. Therefore, a trigger voltage for the discharge lamp 16 is induced in the secondary winding of the trigger transformer. The discharge lamp 16 is responsive to the trigger voltage to discharge.
The operation of the circuit shown in FIG. 13 will be described with reference to FIG. 14. FIG. 14(a) shows the waveform of the alternating current supplied by the commerical power source. The alternating current from the commercial current source 11 is stepped up by the step-up transformer 42 as shown in FIG. 14 (b). The stepped up current has substantially the same frequency as the current from the commercial power source. Assuming the potential VD at a point D of the secondary winding of the transformer 42 is constant, the potentials at points A and B are respectively VA and VB as shown in FIG. 14(b). Also, assuming the potential VD at the point D is constant, the potentials VE and VF at the points E and F vary as shown in FIG. 2(c).
During the period t 0 to t 1 , the potentials VE and VF at the points E and F increase with the potentials VA and VB. At time t 1 , the potential VE at the point E reaches the peak votlage V 1 of the potential VA at the point A. At the same time, the potential VF at the point F reaches the peak voltage V 2 of the potential VB at the point B.
Assuming the thyristor 37 is triggered at time t 2 , a trigger voltage is generated at a trigger electrode 39 of the triger circuit. As a result, the discharge voltage of the discharge lamp 16 is lowered so that the discharge lamp 16 can start discharging the voltage VF at the negative electrode of the discharge lamp 16.
As is well known, once discharge starts, the discharge lamp 16 continues to discharge until the voltage at its terminal drops to zero. Therefore, the discharge lamp 16 continues discharging throughout the period t 2 to t 4 . During this period, the discharge current from the capacitor 15 flows through the anxiliary capacitor 40 to the discharge lamp 16 and then back to the capacitor 15.
Since the capacitance of the auxiliary capacitor 40 is smaller than that of the discharge capacitor 15, the auxilary capacitor 40 is completely discharged earlier than the capacitor 15. For instance, in FIG. 14(c), the auxiliary capacitor 40 finishes discharging at a time t 3 . After the potential on the auxiliary capacitor 40 drops to zero, the discharge current from the capacitor 15 starts to flow through the rectifier 41 and the discharge lamp 16, and then back to the capacitor 15. As mentioned previously the discharge lamp 16 continues to discharge even at relatively low voltages, so that the discharge lamp 16 continue to flash over the period t 3 to t 4 .
Therefore, by properly selecting the capacitance of the capacitor 15, the discharge period of the discharge lamp 16 can be arbitrarily selected. On the other hand, the discharge period of the auxiliary capacitor 40 is independent of the capacitance of the capacitor 15. Thus, the discharge voltage of the auxiliary capacitor 40, which is added to the potential of the capacitor 15, can be large enough to allow discharge of the discharge lamp 16 when the trigger voltage is applied to the trigger electrode 39.
As mentioned previously, according to this embodiment, the capacitance of the discharge capacitor 15 can be increased without degrading the response characteristics of the discharge lamp to the trigger pulse applied to the thyristor 38. Furthermore, the charge on the discharge capacitor 16 can be adjusted by moving point A along the secondary winding of the step-up transformer 42.
If necessary, by grounding the point A of the secondary winding of the step-up transformer, the maximum voltage V 2 between the point F and ground can be made smaller so as to reduce the shock generated when someone contacts the circuit and thus improve safety.
FIG. 15 shows a modification to the fourth embodiment of the power supply circuit for the discharge lamp according to the invention. In this modification, the discharge capacitor 15 is connected to the point B of the secondary winding of the step-up transformer 42 and the auxiliary capacitor 40 is connected to the point A of the secondary winding. This arrangement produces results equivalent of comparable to those of the fourth embodiment.
While the embodiments of FIGS. 13 to 15 employ a common step-up transformer for charging both the discharge capacitor 15 and the auxiliary capacitor 40, it would be possible to charge the capacitors by separate step-up transformers.
FIG. 16 shows another modification to the fourth embodiment, which employs separate step-up transformers 42a and 2b for charging the discharge capacitor 15 and the auxiliary capacitor 40. The rest of the circuitry is substantially the same as in FIG. 15. Therefore, similar or comparable effects are obtained with this modification.
FIG. 17 shows a further modification to the fourth embodiment of FIG. 13, in which a choke coil is employed as a replacement for the step-up transformer in the embodiment of FIG. 13. The choke coil comprises a primary winding 46 and an auxiliary winding 47. The primary winding 46 of the choke coil is connected to a commercial power source 11 via a switching element 45 which comprises a switching transistor, for example. The auxiliary winding 47 of the choke coil is connected in series to the primary winding 46.
The discharge capacitor 15 is connected to the primary winding 46 of the choke coil through the rectifier 14. On the other hand, the auxiliary capacitor 40 is connected to the auxiliary winding 47 of the choke coil via the rectifier 43. As in the fourth embodiment of FIG. 13, an auxiliary rectifier 41 is connected to the auxiliary winding 47 of the choke coil in parallel with the auxiliary capacitor 40.
It should be appreciated that the choke coil serves to build up electricalal energy while the alternating current from the commercial power source is in its positive phase and transmit the accumulated energy to the corresponding capacitors 15 and 40 by reverse electromotive induction after the negative-going zero-crossing of the alternating current. For instance, during the periods t 1 to t 2 , t 3 to t 4 , t 5 to t 6 and t 7 to t 8 , electrical energy is accumulated in the primary and auxiliary windings 46 and 47 of the choke coil, as shown in FIG. 6.
As mentioned with respect to the first embodiment, the magnitude of the electrical energy is determined by the inductance L and the current flowing through the primary winding 46 according to the equation (1). The accumulated energy is distributed to the discharge capacitor 15 and the auxiliary capacitor 40 to charge both, as shown in FIG. 18(b).
FIG. 19 shows a modification to the circuit shown in FIG. 17. In this embodiment, junction E, between the discharge capacitor 15 and the auxiliary capacitor 40 is grounded. By grounding the junction E the voltage between ground and the points F and G become as illustrated in FIG. 18(c). This lowers the severity of the shock received when someone touches the circuit.
FIG. 20 shows the fifth embodiment of the power supply circuit for the discharge lamp 16, such as a xenon lamp, according to the invention. This embodiment is designed to generate a constant flux of light as the discharge lamp discharges.
It should be appreciated that the discharge capacitor 15 is connected to the charge circuit as in the first to fourth embodiments. Any of the charge circuits of the first to fourth embodiments and their modifications would be applicable to this embodiment.
In this embodiment, the discharge capacitor 15, the discharge lamp 16 and an inductor 50 are connected in series. The trigger thyristor 38 is connected to a trigger gate G 1 to receive therethrough a trigger pulse. The trigger thyristor 38 is responsive to the trigger pulse from the trigger gate G 1 to become conductive and so establish electrical communication between the trigger capacitor 37 and the primary winding 33a of the trigger transformer 33. Therefore, the charge on the trigger capacitor 37 is supplied to the primary winding 33a of the trigger transformer 33. As a result, a high voltage is induced in the secondary winding 33b of the trigger transformer 33. This high voltage is applied to the trigger electrode 39. In response to this, the charge on the discharge capacitor 15 is applied to the discharge lamp 16 as a discharge current.
On the other hand, a commutating capacitor 51 and a commutating thyristor 52 are connected in parallel to the inductor 50. The commutating thyristor 53 and the commutating capacitor 51 are mutually connected in series. The commutating thyristor 53 receives a commutation signal through a commutating gate G 2 . While discharge current is being applied to the discharge lamp 16 and the commutating thyristor 53 is held non-conductive due to the absence of the commutation signal, part of the discharge current flows through the rectifier 52 and the commutating capacitor 51 to charge the commutating capacitor, as illustrated by arrow A in FIG. 20. On the other hand, in response to the commutation signal from the commutating gate G 2 , the commutating thyristor 53 becomes conductive and so the commutating capacitor 51 discharges through the path represented by the arrow B.
Assume that the commutating thyristor 53 remains non-conductive, the discharge capacitor 15 is charged to a level sufficient to cause discharge of the discharge lamp 16, and the trigger thyristor 38 is triggered by the trigger pulse through the trigger gate G 1 . The charge on the trigger capacitor 37 is then applied to the primary winding 33a of the trigger transformer 33 to induce a high voltage in the secondary winding 33b. As a result, high voltage is applied to the trigger electrode 39, which starts the discharge lamp 16 discharging. At the same time, part of the discharge current is distributed through the rectifier 52 to the commutating capacitor 51 to charge the latter, as shown in arrow A of FIG. 20.
The commutating signal is applied to the commutating gate G 2 when the integral of the light flux emitted by the discharge lamp 16 reaches a predetermined value. The timing of the commutation signal can be determined by means of a light receiver circuit such as is disclosed in "TOSHIBA SEMICONDUCTOR DATABOOK", page 804 (thyristor of rectifying element). The contents of the reference are hereby incorporated by reference for the sake of disclosure.
In response to the commutation signal, the commutating thyristor 53 becomes conductive to allow discharge of the commutating capacitor 51 through the path B. This discharged potential is applied to the cathode electrode of the discharge lamp 16. As a result, the discharge current from the discharge capacitor 15 is blocked. Specifically, the commutating current from the commutating capacitor 51 flows through the commutating thyristor 53 and the inductor 50. Thus, the voltage across the inductor 50 drops in response to the commutating current. Thereby, the inductor 50 serves to block the discharge current. Immediately there after, the discharge current is cut, as shown in FIG. 21.
In this circuit, the discharge lamp 16 can be turned off when the light output reaches the predetermined value. Therefore, excessive light emission by the discharge lamp 16 can be successfully prevented.
FIG. 22 shows a modification to the fifth embodiment of FIG. 20. In this modification, a commutating transformer 54 is used to turn off the discharge lamp 16. The primary winding 54a of the commutating transformer 54 is connected in series to the discharge lamp 16. On the other hand, the secondary winding 54b of the commutating transformer 54 forms a part of a commutating circuit made up of the commutating thyristor 53 and the commutating capacitor 51.
In this arrangement, the current flowing through the primary winding 54a of the commutating transformer as the discharge current flows to the discharge lamp 16 includes mutual induction so that an induced current flows through the commutating circuit and charges the commutating capacitor 51. When the light output reaches the predetermined integrated value, the commutation signal is applied to the commutating thyristor 53 through the commutating gate G 2 in a manner substantially the same as in the fifth embodiment of FIG. 20. This causes the commutating capacitor 51 to discharge through the secondary winding 54b of the commutating transformer 54. This causes induction in the reverse direction, i.e. opposite the direction of the discharge current. Therefore, the primary coil 54a of the commutating transformer 54 blocks the discharge current.
FIG. 23 shows another modification to the fifth embodiment. As will be appreciated from FIG. 23, the circuit employs a thyristor 55 and voltage regulating element 56. The thyristor 55 is connected in series between the discharge capacitor 15 and the discharge lamp 16. On the other hand, the voltage regulator element 56 is connected in parallel to the thyristor 55 and is connected to the anode of the thyristor. The thyristor 55 and the voltage regulator element 56 prevent the discharge lamp 16 from re-discharging immediately after the discharge current is cut off. Specifically, the thyristor 55 and the voltage regulator element 56 cooperate to prevent the discharge lamp 16 from being re-discharged by the current X shown in FIG. 24. The current X is the discharge current resulting from the residual charge on the discharge capacitor 15 following exhaustion of the charge on the commutating capacitor 51.
FIG. 25 shows the sixth embodiment of the power supply circuit for the discharge current according to the invention, which is especially well suited for flash fixation in dry-type xerographic copiers, facsimile or facsimile telegraphs, printers and so forth. In particular, this embodiment can be used to good advantageous in flash-fixation of toner images.
According to the sixth embodiment, as in the fourth embodiment of FIG. 13, a discharge capacitor 61 and an auxiliary capacitor 62 are employed. The discharge capacitor 61 has a relatively high capacitance and the auxiliary capacitor 62 has a relatively low capacitance. The discharge capacitor 61 is charged by a charge current from a charging source 60 which comprises a step-up transformer, a choke coil or the like and which is connected to the commercial power source 11. The auxiliary capacitor 62 is connected in parallel to the discharge capacitor 61.
The auxiliary capacitor 62 is charged by current from the charging source 60. On the other hand, the discharge capacitor 61 is charged by current flowing via a rectifier 63 from the charging source 60. The voltage V 1 of the charge current to the auxiliary capacitor 62 is higher than the voltage V 2 applied to the discharge capacitor 61. The charge currents charge the auxiliary and discharge capacitors 62 and 61 to the voltage V 1 and V 2 , respectively.
After both of the discharge capacitor 61 and the auxiliary capacitor 62 have been charged, the trigger pulse is applied to the trigger gate G 1 to make the trigger thyristor 38 conductive. This induces a high voltage in the secondary winding of the trigger transformer 33. The high voltage is applied to the trigger electrode 39 to trigger discharge the auxiliary capacitor 62 through the discharge lamp 16. At this time, the discharge from the auxiliary capacitor 62 flows through a choke coil 65, and the discharge lamp 16 and back to the auxiliary capacitor 62. The waveform of the discharge current from the auxiliary capacitor 62 is determined by the capacitance of the auxiliary capacitor, the inductance of the choke coil 65 and impedance of the discharge lamp 16, which specify a discharge time constant. By selecting those parameters, i.e. the capacitance of the auxiliary capacitor 62, the inductance of the choke coil 65 and the impedance of the discharge lamp 16, a relatively large current can be generated in a relatively short period, as shown in the period 0 to 1 msec. of FIG. 27. During this period, the intensity of the discharge lamp 16 reaches a significantly intense peak.
It should be appreciated that the surge-preventive diode 64 prevents the current from the auxiliary capacitor 62 from flowing to the discharge capacitor 61.
After the aforementioned initial intense flash period, i.e. 0 to 1 msec., the current value of the discharge current from the auxiliary capacitor 62 drops to equality with the charge on the discharge capacitor 61. Then, the discharge capacitor 61 starts discharging. At this time, the discharge current flows from the auxiliary capacitor 62, through the choke coil 65 and to the discharge lamp 16 and from the discharge capacitor 61 through the choke coil 65 to the discharge lamp 16. In this case, due to the relatively low voltage discharge from the discharge capacitor, a smaller current flows for a longer period, i.e. between the times 1 msec. to 7 msec. of FIG. 27. During this period, due to the low discharge current, a relatively weak flash is output.
The effects of various kinds of discharge of the discharge lamp will be discussed in order to facilitate full understanding of the advantages of the aforementioned sixth embodiment. Conventionally, it is believed that, given fixed discharge energy, better toner fixation is achieved with a shorter discharge period (pulse width), while, on the other hand, too short a discharge period will cause scattering of the toner and thus degrade the fixed image. When the discharge period is too short, the pulse noise during energization of the discharge lamp is also increased and the toner can be atomized by the abrupt heating, resulting in a bad smell. Therefore, it is conventionally believed that a discharge period in a range of 0.5 msec. to 2.5 msec. is best. However, this approach has not been successful, since toner scattering still tends to degrade the reproduced image.
In another approach, it has been found that high-quality fixation can be achieved by increasing the discharge energy and prolonging the discharge period. This prevents scattering of toner successfully. However, this method is applicable only to high-contrast images. For paler images, high discharge energy and long discharge period serve only to degrade fixation quality.
In the preferred procedure, overall discharge period consists of an initial, intense flash component and a subsequent, weak flash component. This obviates the defects of the conventional processes. This process will be described in greater detail with reference to FIG. 27. In the preferred process, immediately after triggering the discharge lamp, a very large current is applied to the discharge lamp to energize the discharge lamp 16 intensely. An intense flash is achieved within about 1 msec. after triggering. The current level within this period is selected so as not to cause scattering of the toner image even if the toner concentration is high. During this period, a good high-quality fixation of the toner image can be obtained even with a relatively low concentration of toner. Subsequently, for the period 1 msec. to 7 msec. after triggering, a relatively weak current, e.g. about 1/3 of the peak current value, is applied to the discharge lamp 16 to cause relatively weak but prolonged discharge of the discharge lamp 16. During this period, a high-quality high-toner-concentration image can be fixed.
Effects comparable to those of the preferred process can be achieved by performing an intense, brief flash at some timing other than that disclosed above. An example is shown in FIG. 28. A circuit capable of performing the process of FIG. 28 is illustrated in FIG. 26. In the process of FIG. 28, an intense flash occurs during the period 5 msec. to 6 msec. after triggering the discharge lamp.
In the modified circuit of FIG. 26, a diode 66 is interposed between the charging circuit 60 and the auxiliary capacitor 62 and a thyristor 67 is interposed between the capacitor 62 and the choke coil 65. A timing gate G 3 of the thyristor 67 is connected to an appropriate timing circuit which generates a timing signal which controls the thyristor. In the shown embodiment, the timing circuit outputs a timing signal 5 msec. after the discharge lamp 16 is triggered.
Therefore, when the trigger pulse turn ON the trigger thyristor 38 and so induces a high voltage in the trigger electrode 39, at first, the thyristor 67 remains OFF. As a result, the discharge capacitor 61 starts discharging before the auxiliary capacitor 62 starts discharging. The current from the discharge capacitor 61 flows through the diode 64, the choke coil 65 and the discharge lamp 16. The discharge time constant of the discharge capacitor 61 is relatively large so that current through the discharge lamp decreases slowly after it reaches its peak value. After 5 msec., the timing signal is applied to the timing gate G 3 of the thyristor 67 to turn the latter ON. In response to turning ON of the thyristor 67, the auxiliary capacitor 62 start discharging. Then, the current flows through the thyristor 67, the choke coil 65 and the discharge lamp 16. Since the discharge time constant of the auxiliary capacitor 62 is relatively small, the charge on the auxiliary capacitor is exhausted within about 1 msec. Therefore, the circuit of FIG. 26 exhibits the discharge characteristics illustrated in FIG. 28.
In the preferred form of the circuits of FIGS. 25 and 26, the discharge capacitor 61 and the auxiliary capacitor 62 will have capacitances of 125 μF and 825 pF, respectively. The voltages applied to the capacitors 61 and 62 as charge voltages are 3600 V and 1800 V respectively. The discharge lamp 16 is a xenon lamp with an electrode gap of 1000 mm, an internal diameter of 11 mm and a xenon gas pressure of 210 Tor.
This is another approach to high quality fixation, the preferred characteristics of which are illustrated in FIGS. 29 and 30. In order to achieve the characteristics of FIG. 29, a circuit equivalent to FIG. 5 is used. In the preferred arrangement, the capacitance of the discharge capacitor 15 is selected to be 1100 μF. The discharge lamp 16 is a xenon lamp with a 1000-mm electrode gap, an 11-mm diameter and a 210-Tor xenon gas pressure. In addition, a choke coil of 350 μH is inserted between the discharge capacitor and the discharge lamp 16.
The discharge capacitor 15 is charged at a voltage of 1600 V. By applying a trigger pulse at an appropriate timing, the discharge characteristics of FIG. 29 can be obtained.
Alternatively, the preferred process for fixing the tonor image according to this embodiment can be performed by a circuit substantially the same as the circuit illustrated in FIG. 13. In order to perform the preferred process, the xenon lamp with a 1000-mm electrode gap, an 11-mm internal diameter and a 210-Tor xenon gas pressure, is used as the discharge lamp 16. The discharge capacitor 15 has a capacitance of 825 μF and the auxiliary capacitor 40 has a capacitance of 125 μF. As above, a 350 μH choke coil is connected between the capacitors 15 and 40 and the discharge lamp 16. The charge voltage of both the discharge capacitor 15 and the auxiliary capacitor 40 is set to 1800 V. Since the discharge capacitor 15 is connected to the auxiliary capacitor 40 in series, the potential at the point F will be 3600 V and the potential at the point E will be 1800 V.
Therefore, the discharge characteristics of this circuit are as illustrated in FIG. 30.
FIG. 31 shows a flash fixation device performing the fixation process according to the characteristics of FIG. 29 or FIG. 30. A flash section 81 comprises a pair of xenon lamps 83 and 84. A path for blank copy paper 96 is defined beneath the flash section 81. The path includes a conveyor section 82 on which the copy paper is conveyed across the flash section 81.
The flash section 81 further comprises a reflector plate 85 and a transparent dust cover 86. The reflector plate 85 and the transparent dust cover 86 define an internal space through which the xenon lamps 83 and 84 extend. The transparent dust cover may be made of glass. A cooling fan 87 in the internal space defined by the reflector plate 85 and the transparent dust cover supplies ventilation to cool the lamps 83 and 84.
The conveyor section 82 comprises a cross-sectionally rectangular base 89 which defines an internal space. A rectangular tapered section 90 is formed intergrally with or connected to one end of the base 89. A fan 91 is installed at the outer end of the tapered section 90 for ventilation through the internal space of the base 89. A plurality of conveyor belts 92, each of which has a number of longitudinally aligned through openings, are wound around the base 89. The conveyor belts 92 are stretched around idler shafts 95 and a drive shaft 94. The drive shaft 94 is connected to a driving motor 93 to be driven by the latter. The conveyor belts 92 are driven by the driving shaft 94 so as to feed the copy paper across the working face of the flash section 91.
The part of the base 89 opposing the flash section 81 has a plurality of through openings or slits. These opening of slits are intended to allow external air flow due to the fan 91 into the internal space of the base 89. This helps hold the copy paper onto the conveyor belts 92.
The xenon lamps 83 and 84 are triggered to flash when the copy paper passes beneath the flash section. The discharged flash energy melts the toner and so fixes a toner image on the copy paper.
In the shown arrangement, each of the xenon lamps 83 and 84 has an 1000-mm electrode gap, an 11-mm internal diameter and a 210-Tor xenon gas pressure, as in the other embodiments. The width of the transparent dust cover in the conveying direction is 90 mm and the distance from the transparent cover surface to the opposing surface of the copy paper is 10 mm.
Under these conditions, experimental fixation of a linear image and a solid image (all-black image) of 1.6 MacBeth density was performed. The results of these experimets are is illustrated in FIGS. 32(a) to 32(d).
In FIGS. 32(a) to 32(d), (a) shows fixation, (b) shows scattering characteristics, (c) shows amplitude of pulse noise, and (d) shows smell. Triangular points represent data measured for the linear image and circles represent solid image data.
As will be appreciated from FIG. 32(a), for the line image, acceptable fixation can be achieved even when the discharge period (pulse width) is greater than 13 msec. However, for the solid image, acceptable fixation could be obtained with discharge periods equal to or less than 9 msec.
An acceptable degree of scattering obtains at discharge periods equal to or longer than 3 msec. Tests for pulse noise and smell were conducted only for the solid image. As shown in FIGS. 32(c) and 32(d), when the discharge period is equal to or longer than 3 msec., both of the noise level and the smell level are acceptable.
Therefore, by setting the discharge period of the discharge lamp, i.e. the xenon lamp, to within the range of 3 msec. to 9 msec., good fixation characteristics can be obtained.
The preferred embodiments successfully fulfill all of the objects and advantages sought for the invention.
While the present invention has been disclosed in terms of the preferred embodiments of the invention to facilitate better understanding, the invention can be employed in many ways without departing from the principles of the invention set out in the appended claims. Therefore, the invention should be appreciated to include all possible embodiments and modifcations to the shown embodiments which do not depart from the principles of the invention.
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A power supply circuit comprises a single discharge capacitor having a charging sufficient to trigger discharge in a discharge lamp. The discharge capacitor is associated with means for accumulating energy, with which it is charged. The energy accumulating means receives commercially available alternating current and applies the accumulated energy to the discharge capacitor to charge the latter. The power supply circuit may include an auxiliary capacitor which has a smaller capacitance and higher potential rating than the discharge capacitor. The auxiliary capacitor may have a potential rating sufficient to activate the discharge lamp alone. The discharge capacitor cooperates with the auxiliary capacitor to define discharge period. Preferably, the power supply circuit may include means for blocking or shutting off power supply at a given timing to precisely control the discharge period. Such power supply blocking means is especially advantageous for controlling the quantity of light to be emitted by the discharge lamp. The discharge capacitor and the auxiliary capacitor are controlled so as to perform a two-stage flash which includes a first stage with a brief, relatively strong flash and a second stage with a longer, relatively weak flash. This flash is advantageous for fixing toner images with low- and high-toner-density components. Alternatively, the discharge period may be controlled to within a given period to achieve good fixation of the toner image without causing significant noise or smell.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] The present application claims the benefit of U.S. Provisional Patent Application No. 61/745,195, filed on Dec. 21, 2012, the disclosure of which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention is related to cost effective synthesis of 1-bromo-3,3,3-trifluoropropene. More specifically, the present invention is related to the synthesis of 1-bromo-3,3,3-trifluoropropene from the reaction of 3,3,3-trifluoropropyne and HBr.
BACKGROUND OF THE INVENTION
[0003] Chlorofluorocarbons (CFCs) are known and widely used in the industry as solvents, blowing agents, heat transfer fluid, aerosol propellants and other uses. But CFCs are also well-known to have ozone depletion potential (ODP) and are regulated by the Montreal Protocol. A suitable replacement material would have negligible or no ODP, as well as an acceptable global warming potential (GWP).
[0004] 1-Bromo-3,3,3-trifluoropropene, 2-bromo-3,3,3-trifluoropropene and 1,2-dibromo-3,3,3-trifluoropropene each have desirable ODP and GWP, and could potentially used as high efficiency fire extinguisher agents. For example, CN 102319498 A describes a dry powder fire extinguisher having 2-5 wt % of 2-bromo-3,3,3-trifluoropropene, the composition having high moisture-proof performance, high reburning resistance, and high fire extinguishing efficiency. Similarly, Zhang et al found a bromotrifluoropropene/zeolite mixture to be a highly efficient fire extinguisher ( Zhongguo Anquan Kexue Xuebao 2011, 21(5), 53; Process Safety and Enviromental Protection 2007, 85(B2), 147; Huozai Kexue (2010), 19(2), 60-67). 1-Bromo-3,3,3-trifluoropropene with an inert gas have many of the desirable properties of HALON 1301 fire extinguishing agents. The results show that the composites loaded with bromotrifluoropropene exhibited much better performance than that of common dry powders in putting out gasoline fires, requiring less powder, and having shorter fire extinguishing time.
[0005] One existing production process for 1-Bromo-3,3,3-trifluoropropene requires the reaction of 3,3,3-trifluoropropene with bromine, followed by dehydrobromination, to give the target compound. This process is very expensive, and not suitable for large quantity production.
[0006] Other production processes for bromotrifluoropropenes have been investigated. J. Chem. Soc. 1951, 2495 describes bromination of CF3CH═CH2 followed by alkaline treatment to give 2-bromo-3,3,3-trifluoropropene. J. Chem. Soc. 1952, 3490 describes hydrogen bromide (HBr) reaction with 3,3,3-trifluoropropyne at 0° C. or with AlBr 3 at −25° C. to give 1-bromo-3,3,3-trifluoropropene at high yield. Also, HBr reacted with 3,3,3-trifluoropropyne in a sealed cylinder with or without AlBr 3 yields 1-bromo-3,3,3-trifluoropropene in high yield (83-91% yield) when reacted at low temperatures ( J. Chem. Soc. 1952, 3490; J. Am. Chem. Soc. 1952, 650). 2-Bromo-3,3,3-trifluoropropene is an important intermediate for pharmaceutical and agrochemicals and was often used as the precursor of 3,3,3-trifluoroacetylenic anion and could dehydrobrominated with LDA or BuLi at 0° C. ( J. Org. Chem. 2009, 7559-61; J. Flu. Chem. 1996, 80, 145-7). Finally, Mori et al used 1,2-dibromo-3,3,3-trifluoropropene reacting with 20% aqueous NaOH to produce 2-bromo-3,3,3-trifluoropropene in 98% yield (JP 2001322955).
SUMMARY OF THE INVENTION
[0007] There remains a need for an improved process which may be used to efficiently produce bromotrifluoropropenes, and especially 1-bromo-3,3,3-trifluoropropene, in commercial quantities.
[0008] To this end, in accordance with one aspect of the present invention, a process of synthesizing bromotrifluoropropenes comprising mixing 3,3,3-trifluoropropyne with hydrogen bromide to make a first mixture, and subsequently contacting the first mixture with a catalyst at a temperature of at least 50° C. to yield at least one bromotrifluoropropene is provided.
[0009] Additionally, in accordance with a second aspect of the present invention, a process of synthesizing bromotrifluoropropenes comprising reacting 3,3,3-trifluoropropyne with hydrogen bromide without a catalyst at a temperature of at least 50° C. to yield at least one bromotrifluoropropene is provided.
DETAILED DESCRIPTION
[0010] In accordance with the present invention, it was found that 3,3,3-trifluoropropyne could react with HBr at high temperature under the influence of Lewis acid such as CuBr 2 , CuBr, ZnBr 2 , MgBr 2 , AlBr 3 , and other metal bromides (MBrx) to yield a product which contains a mixture of brominated olefins. Typically, the major product yielded was 1-bromo-3,3,3-trifluoropropene, but 2-bromo-3,3,3-trifluoropropene and 1,2-dibromo-3,3,3-trifluoropropene were also produced.
[0011] A variety of ionic solvents can be used for the reaction of 3,3,3-trifluoropropyne with HBr, for example, 1-alkyl-3-methylimidazolium, 1-alkylpyridinium, N-methyl-N-alkylpyrrolidinium and ammonium ions; however, an ionic solvent is not necessary. If an ionic solvent is used, 1-alkyl-3-methylimidazolium bromide is preferred, but a reaction having no such solvent is most preferred.
[0012] Catalysts can also be used. These include mineral acids such as H 2 SO 4 or Lewis acids such as metal salts, especially those of copper, aluminum and antimony (e.g. CuBr 2 , CuBr, and AlBr 3 ). Depending on the temperature of the reaction, the catalyst may not be necessary.
[0013] Reaction temperatures, for reactions at atmospheric pressure, were limited to 50-350° C., but the reaction might proceed at temperatures well above 350° C. To find the appropriate reaction temperature, a pre-mixed 3,3,3-trifluoropropyne and HBr was passed through the heated catalyst/solvent mixture and heating was continued until evidence of reaction was observed, for example, a measured release of heat or generation of volatiles.
[0014] Preferably, the molar ratio of HBr to 3,3,3-trifluoropropyne should be at least one, and can be higher; however, ratios in excess of 3 were not found to be particularly advantageous, and might increase the incidence of side reactions. Molar ratios in the range of 1.1 to 2.5 are particularly preferred.
[0015] In an example embodiment, HBr and 3,3,3-trifluoropropyne are mixed in a stainless cylinder and passed through a mixture of ionic liquid and catalyst or catalyst loaded on activated carbon at 50-350° C. Nitrogen or argon at a speed of 20 ml/m to 100 ml/m is used as a carrying gas. Reactants are controlled by a regulating valve at a rate of 10-50 ml/m. Product out of the reaction vessel is collected by a cooling trap at temperature of −20° C. to −78° C.
[0016] The following examples further illustrate the present invention, but should not be construed to limit the scope of the invention in any way.
EXAMPLES
Example 1
[0017] 3.52 g of CuBr was dissolved in 18 ml of 48% HBr acid at 0° C. To this solution was added 31.7 g of activated carbon (Shirasagi granular, G2 X 4/b-1) under argon. The mixture was briefly vacuumed and then settled under argon overnight. The solvent was removed under vacuum (<80° C.), then heated at 100° C. for 2 hours.
Example 2
[0018] 4.40 g of catalyst from Example 1 was heated in a 10 mm diameter Monel tube in the oven at 300° C. for 4 hours under nitrogen flow of 100 ml/m. Then, the oven was cooled to 250° C., nitrogen flow decreased to 20 ml/m, and 13.0 g of TFP and 15.0 g of HBr mixture in a cylinder was passed through the tube at 250° C. The product of 26.1 g clear liquid was collected in −78° C. trap. NMR analysis showed the presence of 9.47% Cis-1-bromo-3,3,3-trifluoropropene (−61.0 ppm, dd, J=7.6, 19.6 Hz), 64.79% trans-1-bromo-3,3,3-trifluoropropene (−64.7 ppm, dd, J=6.1, 20.1 Hz), 15.40% cis-1,2-dibromo-3,3,3-trifluoropropene (−66.5 ppm, d, J=19.8 Hz,), 10.33% 2-bromo-3,3,3-trifluoropropene (−69.4 ppm, d, J=19.6 Hz).
Example 3
[0019] The CuBr catalyst from Example 2 was reused. The oven was heated to 100° C., and 4.30 g of TFP and 8.10 g of HBr mixture in a cylinder was passed through the tube at 100° C. with nitrogen flow at 20 ml/m. The product of 5.2 g orange liquid was collected in a −78° C. trap. NMR and GC analysis showed that the liquid comprised 23.0% of 3,3,3-trifluoropropyne, 10.60% of cis-1-bromo-3,3,3-trifluoropropene, 56.77% of trans-1-bromo-3,3,3-trifluoropropene, 1.13% of 1,2-dibromo-3,3,3-trifluoropropene, 3.24% of 2-bromo-3,3,3-trifluoropropene, as well as some unidentified products.
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In accordance with the present invention, processes for producing bromofluoropropenes in commercial quantities by reacting 3,3,3-trifluoropropyne with hydrogen bromide at elevated temperatures are provided.
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FIELD OF THE INVENTION
[0001] The present invention relates to materials and methods for treatment of hepatitis C. More closely, the invention relates to human monoclonal antibodies against HCV E1 antigen, to a reagent comprising such antibodies, and to vaccine compositions comprising such antibodies for passive immunisation. Furthermore, the invention relates to a method of treating or preventing HCV infection by administration of a vaccine composition comprising the monoclonal antibodies of the invention for passive immunisation.
BACKGROUND OF THE INVENTION
[0002] Human monoclonal antibodies have been assumed as attractive agents for antagonist effects in many medical applications: anti-toxins, anti-receptor molecules, anti-cytokine reagents to reduce or abolish an inflammatory response, etc.
[0003] Hepatitis C virus (HCV) is a major global health problem, with at least 170 million people infected the world over. HCV results in a chronic infection in 75-80% of those initially infected (Houghton 1996). Very likely, immunological factors influence whether the infection will resolve spontaneously or become chronic. The latter will result in a liver inflammation of variable degree, an inflammation that after 10-20 years may result in cirrhosis (20% of chronic cases), and hepatocellular cancer (HCC; approx. 20% of those with cirrhosis) (Houghton 1996). Current pharmaceutical treatment will fail in 60% of the cases (alpha-interferon+Ribavirin). Thus, there is a need for improved therapy.
[0004] HCV was discovered in 1989. Scientific studies have been severely hampered by the fact that there is no robust method to propagate the virus in vitro. Thus, substances cannot be tested for the capacity to block infection by the virus (neutralization assay). Similarly, the only animal model available is chimpanzee, also limiting the number of studies possible (by cost, availability of animals. etc.). As a substitute for a neutralisation assay, the inhibition of binding of one of the two envelope proteins (E2) to target cells has been developed. This is called the NOB assay: neutralisation of binding. Recently, a replicon system where a subgenomic portion of the viral genome replicates inside cells (but is not assembled into viral particles) has been developed, and optimized.
[0005] As mentioned previously, the immune system may have an important role in determining the course of the infection. Both the cellular immune response, as well as the humoral immune system, have been implicated as important for the outcome of the HCV infection. The relative importance of them is still disputed.
[0006] Whether the humoral immune response (i.e. specific B-lymphocytes and antibodies) can interfere with the clinical course of the disease have gained increasing attention over the last years:
[0007] 1. The kinetics of antibodies to the hypervariable region (HVR) of E2 (one of the envelope glyco proteins) may be important: early occurrence of anti-HVR antibodies correlate with resolution of the acute infection.
[0008] 2. Polyclonal anti-HCV immunoglobulin preparations given to liver transplanted patients decreased the occurrence of re-infection by HCV from 94% to 54%.
[0009] 3. Polyclonal anti-HCV given to infected chimpanzees modulated (ameliorated) the course of the infection.
[0010] 4. Individuals lacking immunoglobulin have a tendency to get a more severe and fast progressing disease compared to immunocompetent individuals.
[0011] 5. Anti-HCV antibodies (particularly NOB positive antibodies) correlated with protection in vaccination experiments.
[0012] Accordingly, several groups and companies are currently exploring the possibilities of affecting the course of the infection by administration of anti-HCV antibodies, both to already infected and for prophylaxis (Burioni et al., 1998).
[0013] The present inventors have already cloned human antibodies to conserved regions of one of the two envelope proteins, E2 (Allander et al., 2000). These antibodies have NOB activity, and a patent application for them has been filed, i.e. WO 9740176. They bind to two or possibly three different regions (epitopes) on E2.
[0014] The role of E1 and E2 in the life cycle of the virus is not fully established, nor is the whole process of virus attachment and entry. Still, antibodies to the HVR of E2 can block infection in animals, and so can antibodies to other parts of HCV (most likely E2). Antibodies to E1 elicited by vaccination in chimpanzees correlated with reduced inflammation of the liver (despite constant viral levels in blood); the mechanism for this is unknown (Maertens et al., 2000). There is currently no report within prior art on human monoclonal antibodies to the E1 protein derived from combinatorial libraries.
SUMMARY OF THE INVENTION
[0015] The present inventors have been able to generate human antibodies to the E1 protein. This was much more complicated than isolating antibodies against the E2 protein, as there seem to be an immuno-dominance in most infected individuals to generate anti-E2 antibodies rather than anti-E1 inmunoglobulins. Initially, the inventors worked with a recombinant protein resembling the complexed E1/E2, the assumed native complex presented on the viral surface. Only anti-E2 antibodies could be isolated in those experiments. To solve the problem of generating anti-E1 antibodies, E1 was first cloned and expressed separately on the surface of eukaryotic cells. Subsequently, such E1 displaying cells were used for selection of anti-E1 binding clones from an antibody library displayed on filamentous phage, in order to avoid the immunodominant anti-E2 clones present in the phage antibody library.
[0016] In a first aspect, the invention provides a recombinant human monoclonal antibody, or antigen binding fragments thereof, that exhibits immunological binding affinity for a hepatitis C virus (HCV) E1 antigen, wherein said monoclonal antibody comprises an amino acid sequence homologous to the binding portion of a human antibody Fab molecule obtained from a combinatorial antibody library.
[0017] The monoclonal antibody according to the invention reacts with complexed HCV E1/E2 antigen. The monoclonal antibody according to the invention preferably reacts with genotypically different isolates of HCV virus. Furthermore, the monoclonal antibody according to the invention may be improved by mutation and new selection, i.e. so called affinity maturation in vitro, to increase the binding strength of the antibodies to E1.
[0018] The Fab molecule of the monoclonal antibody of the invention comprises the VH and VL domains respectively, of the heavy and light chains of the Fab molecule according to Seq. ID No. 1-56 of the enclosed Sequence Listning.
[0019] The monoclonal antibody according to the invention may be fused with a further substance for diagnostic or therapeutic purposes, for example a toxin, an antibody allowing targeting, e.g. against defense cells, a protein conferring modulated metabolism of the anti-E1 antibody, a marker for diagnosis, immunohistochemistry, imaging etc.
[0020] In a second aspect, the invention relates to a detecting immunological reagent comprising the monoclonal antibody according to the invention. For example, the reagent may be used in quantitative assays for detection and analysis of replication and assembly in the life cycle of the virus.
[0021] In a third aspect, the invention relates to an immunological assay comprising the above reagent. The assay may be a modified NOB assay as mentioned above. Alternatively, the immunoassay may be a qualitative assay to measure conformation of recombinant E1 in connection with the production of therapeutic and diagnostic agents.
[0022] In a fourth aspect, the invention relates to a drug or vaccine composition against HCV infection, comprising the monoclonal antibody according to the invention or any combination of antibodies, or antibody binding fragments, of the invention. The vaccine compositon is formulated with pharmaceutically acceptable vehicles in a conventional manner and is intended for passive immunisation.
[0023] According to the present invention it is possible to produce human antibodies to parts of E2 (in particular the HVR region), and to the envelope protein, E1, in order to compose a “cocktail” of 3-6 or more human monoclonal antibodies. Such a mixture of antibodies to different proteins and protein regions of the virus has a much larger probability of severely affecting such a variable virus as HCV.
[0024] In a fifth aspect, the invention provides a method of treating a subject against HCV infection in a therapeutic or prophylactic purpose, comprising administration of the vaccine composition according to the invention to subjects in need thereof.
DETAILED DESCRIPTION OF THE INVENTION
Materials and Methods
[0025] Antibodies and Antisera
[0026] Monoclonal mouse anti-human-myc from Invitrogen was used in 1:1.50-1:75 dilution (9-19 μg/ml). Ascites produced mouse anti-E1 monoclonal antibody was diluted 1:250. A FITC conjugated rabbit-anti-mouse immunoglobulin from Dako was used as secondary antibody in 1:15-1:10 dilution (67-100 μg/ml).
[0027] Anti-HCV Phage Library Construction
[0028] The library was derived from a bone marrow donation from a patient infected with HCV genotype 1a. Construction of the library was performed as described in Allander et al., 2000. In brief, lymphocytes were isolated from bone marrow using Ficoll-Paque (Pharmacia), and total RNA was extracted by the acid guanidium thiocyanate-phenol method. First strand cDNA synthesis was performed using an oligo-dT primer and the “First strand cDNA synthesis” kit (Amersham Pharmacia). The cDNA was subsequently used as template for for PCR amplification of γ1 Fd and κ light chains (Kang et al., 1991), and ligated into the phagemid vector pComb3H (Barbas and Wagner, 1995).
[0029] Construction of E1 Expression Vector
[0030] The signal sequence and echtodomain of E1 (aa 174 to 359) was inserted into the vector pDisplay (Invitrogen). The pDisplay vector has a mouse Igκ signal sequence upstream of its cloning cassette and a PDGF membrane anchor sequence downstream of the cassette for cell-surface expression. In addition, the vector contains two tag sequences so that the expressed protein will have a N-terminal Hemagglutinin A epitope tag, and a C-terminal myc epitope tag before the membrane anchor. The signal sequence and echtodomain fragment of E1 was PCR amplified from a full-length HCV clone (pcv H77c, genotype 1a), which was a generous gift from Dr J Bucht, NIH, USA (Yanagi et al., 1997). Since the hemagglutinin A tag would be localized N-terminal of the E1 fragment and possibly disturb recognition by anti-E1 or anti-myc antibodies, the signal sequence and the Hemagglutinin tag were deleted from the vector using Eco RI and Pst I (Life Technologies). The E1 fragment was subsequently inserted with the 3′ end in the cloning cassette and the 5′ end replacing the removed sequences. The PCR was performed as follows: first 94° C. 5 min; then 94° C. 1 min, 52° C. 0.5 min, and 72° C. 10 min for 35 cycles; and finally 72° C. 10 min. Primers (Symbion, Denmark) were designed to contain specific restriction enzyme sites for directional cloning and an ATG start codon in the sense primers: sense primer (H77C-S1b) 5′-GG AAC CTT CCT GAA TTC GGC TTG GGG ATG TTC TCT ATC-3′ (restriction site for Eco RI underlined), antisense primer (H77C-AS1) 5′-CAT GGA GAA ATA CGC CTG CAG CGC CAG-3′ (restriction site for Pst I underlined). The PCR fragment was cleaved with the mentioned restriction endonucleases, and gel purified on 1% agarose. The band of correct size (approx. 600 bp) was cut out from the gel, and DNA was eluted using Concert DNA purification kit (Life Technologies). The pDisplay vector (Invitrogen) was cut using the same restriction enzymes and likewise gel purified. The fragment was ligated to the vector in 1:1, 1:3 and 1:6 ratios at +4° C. o.n. using T4 DNA ligase (Life Technologies). The 1:1 ligation product was linearized, self-religated and used to transform E- coli (XL-1 Blue, Stratagene) by electroporation. Single ampicillin resistant clones were picked and cultured, and DNA was extracted using Wizards Plus Midipreps DNA purification system (Promega). To distinguish which clones contained correct insert, DNA from single clones was analyzed both by PCR and by restriction enzyme digestion.
[0031] Detection of E1 Expression on Eukaryotic Cells
[0032] Expression of the E1-myc construct was tested in CHO and HeLa cells. Cells were grown in 6-well plates to near confluence in RMPI 1640 (CHO cells) or DMEM (HeLa cells) supplemented with 10% fetal bovine serum (FBS) and 100 U /ml penicillin, streptomycin 100 μg/ml (Life Technologies). Transfection was performed using FuGENE 6 (Boehringer-Mannheim) with a FuGENE 6 to DNA ratio of 3-6 μl to 1-2 μg per well. Geneticin (Life Technologies) was added to the culture media, in a final concentration of 200 μg/ml, 48 h after transfection. Analysis with immunofluorescence microscope (Leitz DMRBE, Leica) and flowcytometry (FacSort, Becton Dickinson) were carried out on solubilized cells. Cells were loosened using a rubber policeman and washed twice in wash buffer Dulbeccos' PBS, 0.5% FBS, 0.1% sodium azide (Life Technologies, USA). Cells were centrifuged and resuspended in a small volume of primary antibody (anti-myc or anti-E1) and incubated at RT for 60 min. After two to three washes in wash buffer, cells were incubated in the dark at RT for 30 min in secondary rabbit-anti-mouse Ig-FITC. Finally cells were briefly incubated in Hoerst 1:1000, washed 3 times and mounted on glass slides in 5-10 μl Vectashield(Vector). Cells to be analysed with flowcytometry were redisolved in 250 μl washbuffer.
[0033] Selection of Anti-E1 Clones
[0034] Anti-E1 clones were selected from three different sets of selections. For the first two sets, HeLa cells were grown to semi confluence in T75 culture flasks. In the first set of selections, cells were transfected with 8-9 μg E1 DNA (47-53 μl Fugene6). In the second set, HeLa cells were transfected twice with the E1 DNA to further increase the surface expression prior to selection. Cells were first transfected (5.5 μg DNA) in a T25 culture flask for two days, grown under Geneticin selection pressure for 5 days, and then moved and transfected in a T75 flask (16 μg DNA). In the third set, CHO cells were used because of their higher surface expression even after the first transfection. Cells were transfected with 16-30 μg DNA in T75 flasks. One to four days after transfection cells were harvested using a rubber policeman, and suspended in DPBS—4% nonfat milk—0.02% sodium azide. To deplete the phage library of non-specific binders, the phages were incubated with non-transfected cells for one hour on an orbit shaker 100 rpm at RT or incubated overnight at +4° C. and then on a turning-wheel (7 rpm) for one hour at RT. Cells were removed by centrifugation, and the depleted phages were incubated with transfected cells for 1.5-2 h on a turning-wheel at RT. Cells were then washed three times in wash-buffer (Dulbeccos PBS, 0.5% FBS, 0.02% sodium azide). Cells were resuspended in 100 μl anti-myc 1:75 dilution and incubated at RT for 2 h. After two washes the cells were resuspended in FITC-anti-mouse—IgG 1:15 dilution and incubated in the dark for 1 h. The cells were washed twice before resuspended (10 6 cells/ml) in wash-buffer. Sorting was performed in a FACSVantage SE (Becton Dickinson). Phages were eluted from the sorted cells by adding 200 μl 0.1 M HCl-glycine pH 2.2. Eluted phages were used to infect freshly cultured XL-1 Blue. The infected bacteria were then plated out on LA-amp plates. The next day, colonies were harvested in SB and grown to a 50-100 ml culture. Phages were induced and harvested as described (Barbas et al., 1991), and used for a next round of selection.
[0035] Fab Expression and Initial Testing
[0036] Colonies were picked, propagated and analyzed as single clones. Fab production was induced and a periplasmic fraction was prepared by freeze thawing (Allander et al 2000). Fab production was determined in an ELISA using anti-Fd (The Binding Site, UK) and AP conjugated anti-Fab (PIERCE, USA). Specificity for the antigen was initially tested in an ELISA against an recombinant E1/E2 protein, or against recombinant E1 protein. The recombinant E1/E2 heterodimer protein (genotype 1a) expressed in CHO cells was generously provided by Dr M. Houghton, Chiron Corp. and has been described elsewhere (Spaete et al., 1992). The soluble E1 protein was expressed and secreted into the medium from COS cells, and was generously provided by Dr. A. Patel, MRC Virology Unit, Glasgow, U.K. The ELISA assays with these antigens were performed as described below.
[0037] ELISA Assay for Determination of Specific Binding of the Antibodies to HCV Proteins
[0038] ELISA for E1 reactivity: GNA lectin (Sigma) was diluted to 2.5 μg/ml in PBS and coated to microtiter wells (Costar 3690) over night at room temperature. The wells were washed once in PBS with 0.05% Tween 20 (PBS-T) and the wells were blocked with 4% non-fat dry milk in PBS for 2 hours at room temperature. A:fter discarding the blocking solution, 50 μl of recombinant E1 (approx. concentration 50 μg/ml) was added and incubated for two hours at room temperature. After the E1 solution had been discarded, the antibody preparations were added and bound antibodies detected as described below.
[0039] Recombinant E1/E2 heterodimer (genotype 1a) was diluted to 1 μg/ml in PBS, and coated to microtitre wells overnight at +4° C. Unbound antigen was discarded, and the wells were blocked with 5% non-fat dry milk in PBS for 60 minutes at room temperature. Blocking solution was discarded, and antibody solutions to be tested added in 1:3-1:24 dilutions (diluent: PBS with 0.05% Tween 20). The plates were incubated at 37° C. temperature for 2 hours, washed four times with PBS-T, and alkaline phosphatase (AP) coupled-goat anti-human F(ab′) 2 (Pierce, Rocherford, Ill.) antibodies in a 1:1000 dilution were added. After 60 minutes at 37° and subsequent washes, substrate solution (p-nitrophenyl phosphate, Sigma, St. Louis, Mo.) was added and absorbency measured at 405 nm.
[0040] For control purposes, recombinant E2 (genotype 1a), or BSA (Sigma) coated at 1 μg/ml were used in corresponding ELISAs to control for unspecific reactivity.
[0041] Transfer of Fab Clones into IgG Format
[0042] The Fd and the light chain gene segments were transferred from the phagernide vector pComb3H to the eukaryotic vector pcIgG1 as previously reported (Samuelsson et al., 1996). Plasmid DNA was transfected into CHO cells using Lipofectamine Plus (Life Technologies) according to the manufacturer's instructions. Medium containing secreted IgG was harvested every second day and frozen until analyzed. The ELISA to determine IgG concentration used a rabbit anti-human IgG and an AP conjugated rabbit anti-human IgG, and a purified human IgG standard as reference (Dako) (Samuelsson et al., 1996).
RESULTS
[0043] Library Size
[0044] Ligation of γ1 Fd genes into the pComb3H vector gave a library of 7.8×10 6 cfu/μg, and ligation of κ light chain genes into the pComb3H gave a library of 1.6×10 7 cfu/μg. The resulting combinatorial library comprised 3.7×10 7 members.
[0045] Construction of E1 Expression Vector
[0046] The first ligation of pDisplay vector and E1 fragment resulted in similar number of clones independent of ligation ratios. Plasmid DNA extracted from cultures of the 1:1 ligation was linearized and separated on a gel. Two bands of approximately 5.5 and 6.0 appeared on the gel. Since the expected correct sized band was 5.8 kb, both bands were purified and religated separately. Single clones were grown and insertion of the fragment was demonstrated by PCR using the same sense and antisense primers as in the cloning step; 9 clones out of 20 showed the correct fragment length. Subsequent restriction enzyme digestion showed that the correct sized fragment also could be cleaved from all 9 clones. Nucleic acid sequencing of the clones showed that they all differed from the original E1 sequence by a few nucleotides or more.
[0047] Assessment of E1 Expression on Eucaryotic Cells
[0048] Initially HeLa cells were preferred. To determine optimal expression of the myc-tag, expression was investigated by fluorescence microscopy and flow cytometry on day 1, 2, 4, and 7 after transfection. This time study indicated that immunofluorescence detection of the myc tag was optimal 4 days after transfection. For the second set of selection surface expression was increased slightly by transfecting the HeLa cells twice. For the third set CHO cells were chosen since they appear to be more tolerant to transfection as well as show clear E1 expression already after one day of transfection.
[0049] Selection of E1 Specific Clones
[0050] In the first round of each selection series, approximately 10 11 cfiu of phage library was depleted against 10 6 -10 7 non-transfected cells. Unbound, depleted phages were subsequently incubated with 3-8×10 6 transfected, E1 expressing cells. After sorting for myc positive cells, phages were eluted from the sorted cells and re-propagated in fresh XL1 blue. 2-8×10 10 cfu of re-propagated phages were used in the next selection round.
[0051] In the first series, two rounds of selection were performed. After the second round, only 108 colonies were formed, 98 of which were tested in ELISAs for Fab expression and binding to recombinant E1/E2 antigen. Sixteen clones expressed Fab, of which nine were positive for binding to E1/E2. After nucleic acid sequencing, two clones were judged not to be proper Fab fragments. Two clones (clones 13 and 98) from this selection series were further characterised and included in the present collection of antibodies (Table 1, Seq ID No. 1-4).
[0052] In the second series, six selection rounds were performed. After the fourth round, 42 single clones were picked and assayed for Fab expression. Twentytwo clones produced Fab, while only two were positive when tested for E1 reactivity. Subsequent sequence analysis revealed that the clones were identical (clone 4:6; Seq ID No. 13-14). An additional clone, isolated from the sixth panning round in this series, was also characterised (clone 6a:5; Table 1 and Seq ID No. 15-16).
[0053] In the third series, two rounds of selection were made and the second round was repeated once. 45-75% of propagated clones expressed Fab. The majority of our E1 specific Fab clones were isolated from this selection series (clones with prefix 1:, 2a: and 2b:).
[0054] Reactivity to HCV Antigens
[0055] The reactivity of the different Fab clones to the HCV proteins E1, E1/E2 in complex, free E2 or BSA was determined by ELISA. All clones showed a significantly higher reactivity to E1 and/or E1/E2 than against E2 or BSA (negative control antigens) (Table 1). From these data, it seems that some clones may be particularly efficient binders: clones 1.4, 1:8, 2a: 13, 2a:23, 2a:30, 2b:5 and 4:6
TABLE 1 Reactivity to HCV antigens and BSA by the Fab proteins (crude periplasmic preparations) as measured by ELISA (OD 405 nm values given). For technical reasons, E2 was in some experiments replaced with BSA as negative control antigen (values marked with (B)). n d = not determined μg Fab/ml Fab clone E1 E1/E2 E2 or BSA (B) (approximative) 13 0.20 0.16 0.03 (B) >3 98 0.20 0.16 0.10 (B) 5 1:4 0.78 0.67 0.27 (B) 0.01 1:8 0.75 0.53 0.09 (B) 0.01 1:9 0.96 0.67 0.16 (B) 0.05 1:10 0.20 0.12 0.01 (B) 0.01 4:6 0.97 0.20 0.08 0.24 6a:5 0.15 0.09 0.03 0.33 2a-2 1.00 0.32 0.18 0.64 2a-4 1.18 0.42 0.33 1.0 2a-5 0.89 0.08 0.07 0.44 2a-13 1.05 0.22 0.14 0.36 2a-14 0.36 0.09 0.07 0.72 2a-23 1.47 0.23 0.19 0.50 2a-25 1.46 0.33 0.24 0.11 2a-30 1.11 0.52 0.26 0.96 2a-32 0.61 0.09 0.07 >1 2a-33 0.65 0.14 0.14 >1 2a-37 0.99 0.48 0.29 (B) 0.08 2a-40 1.21 0.17 0.17 1.0 2b-1 0.35 0.12 0.08 0.94 2b-3 1.18 0.19 0.12 1.0 2b-4 0.11 0.09 0.03 (B) 0.68 2b-5 2.21 1.40 0.71 >1.0 2b-7 0.47 0.32 0.18 0.54 2b-9 0.33 0.19 0.15 0.19 2b-10 0.48 0.11 0.13 >1.0 2b-17 0.24 n d 0.05 0.16 mouse mcl anti-E1 >3.00 >3.00 0.20 rabbit anti-E2 n d 0.15 0.72 PBS 0.11 0.10 0.08 non-specific Fab 0.20 0.11 0.14 (B)
[0056] References
[0057] Allander T, Drakenberg K, Beyene A, Rosa D, Abrignani S, Houghton M, Widell A, Grillner L, Persson MAA. Recombinant human monoclonal antibodies against different conformational epitopes of the E2 envelope glycoprotein of hepatitis C virus that inhibit its interactions with CD81. J Gen Virol 2000; 81: 2451-2459.
[0058] Barbas III C F, Kang A S, Lerner R A, Benkovic S J. Assembly of combinatorial antibody libraries on phage surfaces: the gene III site. Proc Natl Acad Sci U S A 1991; 88: 7978-82.
[0059] Barbas III C F, Wagner J. Synthetic human antibodies: selecting and evolving finctional proteins. Methods 1995; 8: 94-103.
[0060] Burioni R, Plaisant P, Manzin A, Rosa D, Delli Carri V, Bugli F, Solforosi L, Abrignani S, Varaldo P E, Fadda G, Clementi M. Dissection of human humoral immune response against hepatitis C virus E2 glycoprotein by repertoire cloning and generation of recombinant Fab fragments. Hepatology 1998; 28: 810-814.
[0061] Houghton M. Hepatitis C Virus. In Fields Virology, (eds B N Fields, D M Knipe, P M Howley) Lippincott-Raven Publishers, Philadelphia, 1996 pp1035-1058.
[0062] Kang A S, Burton D R, Lemer R A. Combinatorial inimunoglobulin libraries in phage λ. Methods: Comp. Methods in Enzymol. 1991;2: 111-8.
[0063] Maertens G, Priem S, Ducatteeuw A, Verschoorl E, Verstrepen B, Roskams T, Desmet V, Fuller S, Van Hoek K, Vandeponseele P, Bosman F, Buyse M A, van Doom L J, Heeney J, Kos A, Depla E. Improvement of chronic active hepatitis C in chronically infected chimpanzees after therapeutic vaccination with the HCV E1 protein. Acta Gastroenterologica Belgica. 2000; 63: 203.
[0064] Samuelsson A, Yari F, Hinkula J, Ersoy O, Norrby E, Persson M A A. Human antibodies from phage libraries: neutralizing activity against human immunodeficiency virus type 1 equally improved after expression as Fab and IgG in mammalian cells. Eur J Immunol 1996; 26: 3029-34.
[0065] Spaete R R, Alexander D, Rugroden M E, Choo Q L, Berger K, Crawford K, Kuo C, Leng S, Lee C, Ralston R, and others. Characterization of the hepatitis C virus E2/NS 1 gene product expressed mammalian cells. Virology 1992; 188: 819-830.
[0066] Yanagi M, Purcell R H, Emerson S U, Bukh J. Transcripts from a single full-length cDNA clone of hepatitis C virus are infectious when directly transfected into the liver of a chimpanzee. Proc Natl Acad Sci USA 1997; 94:8738-8743.
1
56
1
127
PRT
Homo sapiens
PEPTIDE
(1)..(127)
Clone 13 VH
1
Ala Glu Val Gln Leu Leu Glu Ser Gly Gly Gly Leu Val Gln Pro Gly
1 5 10 15
Arg Ser Leu Arg Leu Ser Cys Ala Ala Ser Gly Phe Thr Phe Asp Asp
20 25 30
Tyr Gly Met His Trp Val Arg Gln Ala Pro Gly Lys Gly Leu Glu Trp
35 40 45
Val Ser Gly Leu Ser Trp Asn Ser Asp Asn Ile Gly Tyr Ala Asp Ser
50 55 60
Val Lys Gly Arg Phe Thr Ile Ser Arg Asp Asn Ala Lys Asn Ser Leu
65 70 75 80
Tyr Leu Gln Met Asn Ser Leu Lys Ile Glu Asp Thr Ala Phe Tyr Tyr
85 90 95
Cys Ala Lys Ala Pro Arg Thr Leu Arg Phe Leu Glu Trp His Asn Val
100 105 110
Tyr Phe Asp Leu Trp Gly Arg Gly Thr Leu Val Thr Val Ser Ser
115 120 125
2
112
PRT
Homo sapiens
PEPTIDE
(1)..(112)
Clone 13 VK
2
Ala Glu Leu Thr Gln Ser Pro Asp Ser Leu Ala Val Ser Leu Gly Glu
1 5 10 15
Arg Ala Thr Ile Asn Cys Lys Ser Ser Gln Ser Val Leu Tyr Ser Ser
20 25 30
His Asn Lys Asn Tyr Leu Ala Trp Tyr Gln Gln Lys Pro Gly Gln Pro
35 40 45
Pro Lys Leu Leu Ile Tyr Trp Ala Ser Thr Arg Glu Ser Gly Val Pro
50 55 60
Asp Arg Phe Ser Gly Ser Gly Ser Gly Thr Asp Phe Thr Leu Thr Ile
65 70 75 80
Ser Ser Leu Gln Ala Glu Asp Val Ala Val Tyr Tyr Cys Gln Gln Tyr
85 90 95
Phe Ser Thr Pro Leu Thr Phe Gly Gly Gly Thr Lys Val Glu Ile Lys
100 105 110
3
133
PRT
Homo sapiens
PEPTIDE
(1)..(133)
Clone 98 VH
3
Ala Glu Val Gln Leu Leu Glu Gln Ser Gly Ala Glu Val Lys Lys Pro
1 5 10 15
Gly Glu Ser Leu Arg Ile Ser Cys Arg Gly Ser Gly Tyr Ser Phe Pro
20 25 30
Asn Tyr Trp Val Ser Trp Val Arg Gln Met Pro Gly Lys Gly Leu Glu
35 40 45
Trp Met Gly Lys Ile Asp Pro Ser Asp Ser Glu Thr Asn Tyr Ser Pro
50 55 60
Ser Phe Gln Gly His Val Thr Ile Ser Ala Asp Lys Ser Leu Ser Ile
65 70 75 80
Ala Tyr Leu Gln Trp Asn Ser Leu Lys Ala Ser Asp Thr Ala Met Tyr
85 90 95
His Cys Ala Arg His Lys Arg Gly Ala Pro Thr Tyr Lys Asp Ile Leu
100 105 110
Thr Gly Tyr Tyr Val Asp Gly Met Asp Val Trp Gly Gln Gly Thr Thr
115 120 125
Asp Thr Val Ser Ser
130
4
106
PRT
Homo sapiens
PEPTIDE
(1)..(106)
Clone 98 VK
4
Ala Glu Leu Thr Gln Ser Pro Ser Ser Leu Ser Ala Ser Val Gly Asp
1 5 10 15
Arg Val Thr Ile Thr Cys Gln Ala Ser Pro Asp Ile Ser Asn Tyr Leu
20 25 30
Asn Trp Tyr Gln Gln Lys Pro Gly Lys Ala Pro Asn Leu Leu Ile Tyr
35 40 45
Gly Ala Ser Ser Leu Gln Arg Gly Val Pro Ser Arg Leu Ser Gly Ser
50 55 60
Gly Ser Gly Thr Asp Phe Thr Leu Thr Ile Asp Ser Leu Gln Pro Glu
65 70 75 80
Asp Phe Ala Thr Tyr Tyr Cys Gln Gln Ser Tyr Gly Ser Pro His Thr
85 90 95
Phe Gly Gln Gly Thr Lys Val Glu Ile Lys
100 105
5
125
PRT
Homo sapiens
PEPTIDE
(1)..(125)
Clone 14 VH
5
Ala Glu Val Gln Leu Leu Glu Ser Gly Pro Gly Leu Val Lys Pro Ser
1 5 10 15
Glu Thr Leu Ser Leu Thr Cys Thr Val Ser Asn Gly Ser Met Ser Asn
20 25 30
Tyr Cys Trp Ser Trp Ile Arg Gln Ser Pro Gly Lys Gly Leu Glu Trp
35 40 45
Ile Gly Tyr Ile Tyr Tyr Ser Gly Ser Thr Ser Tyr Asn Pro Ser Leu
50 55 60
Arg Ser Arg Val Ala Leu Leu Val Asp Thr Ser Lys Asn Gln Phe Ser
65 70 75 80
Leu Lys Leu Thr Ser Val Thr Thr Ala Asp Thr Ala Val Tyr Tyr Cys
85 90 95
Ala Arg Asp Leu Ser Ala Arg Gly Gly Thr Arg Asn Arg Asp Ala Leu
100 105 110
Asp Val Trp Gly Gln Gly Thr Gln Val Thr Val Ser Ala
115 120 125
6
107
PRT
Homo sapiens
PEPTIDE
(1)..(107)
Clone 14 VK
6
Ala Glu Leu Thr Gln Ser Pro Ala Thr Leu Ser Val Ser Pro Gly Glu
1 5 10 15
Arg Ala Thr Leu Ser Cys Arg Ala Ser Gln Ser Val Asn Ser Asn Leu
20 25 30
Ala Trp Tyr Gln Gln Lys Pro Gly Gln Ala Pro Ser Leu Leu Ile Tyr
35 40 45
Gly Ala Ser Thr Arg Ala Thr Gly Ile Pro Ala Arg Phe Ser Gly Ser
50 55 60
Gly Ser Gly Thr Glu Leu Thr Leu Thr Ile Ser Ser Leu Gln Ser Glu
65 70 75 80
Asp Phe Ala Val Tyr Tyr Cys Gln Gln Tyr Lys Asn Trp Pro Pro Trp
85 90 95
Thr Phe Gly Gln Gly Thr Lys Val Glu Ile Lys
100 105
7
127
PRT
Homo sapiens
PEPTIDE
(1)..(127)
Clone 18 VH
7
Ala Glu Val Gln Leu Leu Glu Ser Gly Gly Gly Leu Val Glu Pro Gly
1 5 10 15
Arg Ser Leu Arg Leu Ser Cys Ala Ala Ser Gly Phe Asn Phe Gly Asp
20 25 30
Tyr Ala Ile His Trp Val Arg Gln Gly Pro Gly Lys Gly Leu Glu Trp
35 40 45
Val Ala Gly Ile Ser Trp Asn Ser Gly Ser Ile Gly Tyr Ala Asp Ser
50 55 60
Val Lys Gly Arg Phe Ile Ile Ser Arg Asp Asn Ala Lys Lys Thr Leu
65 70 75 80
Phe Leu Gln Met Asn Thr Leu Arg Thr Glu Asp Thr Ala Leu Tyr Tyr
85 90 95
Cys Val Lys Glu Thr Gly Ala Gln Gly Val Ala Gly Ser Gly Ala Tyr
100 105 110
Tyr Phe His Asn Trp Gly Gln Gly Thr Leu Val Thr Val Ser Ser
115 120 125
8
106
PRT
Homo sapiens
PEPTIDE
(1)..(106)
Clone 18 VK
8
Ala Glu Leu Thr Gln Ser Pro Ser Ser Leu Ser Ala Ser Ile Gly Asp
1 5 10 15
Arg Val Thr Ile Thr Cys Arg Ala Ser Gln Gly Ile Ser Asn Tyr Val
20 25 30
Ala Trp Tyr Gln Gln Arg Pro Gly Lys Val Pro Lys Leu Leu Ile Phe
35 40 45
Gly Ala Ser Ala Leu His Ser Gly Val Pro Ser Arg Phe Ser Gly Ser
50 55 60
Gly Ser Gly Thr Asp Phe Thr Leu Thr Ile Thr Ser Leu Gln Pro Glu
65 70 75 80
Asp Val Ala Thr Tyr Tyr Cys Gln Lys Tyr Arg Ser Ala Pro Leu Thr
85 90 95
Phe Gly Pro Gly Thr Arg Val Asp Leu Lys
100 105
9
121
PRT
Homo sapiens
PEPTIDE
(1)..(121)
Clone 19 VH
9
Ala Glu Val Gln Leu Leu Glu Ser Gly Pro Gly Leu Val Lys Pro Ser
1 5 10 15
Glu Thr Leu Ser Leu Thr Cys Thr Val Ser Gly Asn Ser Ile Ser Ser
20 25 30
Gly Tyr Tyr Trp Val Trp Phe Arg Gln Ser Pro Gly Lys Gly Leu Glu
35 40 45
Trp Ile Ala Ser Ile Tyr His Ser Gly Ser Thr Tyr Tyr Asn Pro Ser
50 55 60
Leu Arg Ser Arg Val Ser Ile Ser Val Asp Thr Ser Lys Lys Gln Phe
65 70 75 80
Ser Leu Lys Leu Ser Ser Val Thr Ala Ala Asp Thr Ala Val Tyr Tyr
85 90 95
Cys Ala Arg Asp Ser Ala Lys Thr Thr Arg Tyr Phe Val His Trp Gly
100 105 110
Gln Gly Thr Leu Val Thr Val Ser Ser
115 120
10
109
PRT
Homo sapiens
PEPTIDE
(1)..(109)
Clone 19 VK
10
Ala Glu Leu Thr Gln Ser Pro Gly Thr Leu Ser Leu Ser Pro Gly Glu
1 5 10 15
Arg Ala Thr Leu Ser Cys Arg Ala Ser Gln Ser Val Ser Ser Ser Tyr
20 25 30
Leu Ala Trp Tyr Gln Gln Lys Ala Gly Gln Ala Pro Arg Leu Leu Ile
35 40 45
Tyr Gly Ala Ser Arg Arg Ala Thr Gly Ile Pro Val Arg Phe Ser Gly
50 55 60
Ser Gly Ser Gly Ala Glu Phe Thr Leu Thr Ile Ser Ser Leu Gln Ser
65 70 75 80
Glu Asp Ser Ala Val Tyr Tyr Cys Gln His Tyr His Asn Trp Pro Ala
85 90 95
Met Tyr Thr Phe Gly Gln Gly Thr Lys Leu Glu Ile Lys
100 105
11
132
PRT
Homo sapiens
PEPTIDE
(1)..(132)
Clone 110 VH
11
Ala Glu Val Gln Leu Leu Glu Ser Gly Ala Glu Val Lys Lys Pro Gly
1 5 10 15
Glu Ser Leu Arg Ile Ser Cys Arg Gly Ser Gly Tyr Ser Phe Pro Asn
20 25 30
Tyr Trp Val Ser Trp Val Arg Gln Met Pro Gly Lys Gly Leu Glu Trp
35 40 45
Met Gly Lys Ile Asp Pro Ser Asp Ser Glu Thr Asn Tyr Ser Pro Ser
50 55 60
Phe Gln Gly His Val Thr Ile Ser Ala Asp Lys Ser Leu Ser Ile Ala
65 70 75 80
Tyr Leu Gln Trp Asn Ser Leu Lys Ala Ser Asp Thr Ala Met Tyr Tyr
85 90 95
Cys Ala Arg His Lys Arg Gly Ala Pro Thr Tyr Lys Asp Ile Leu Thr
100 105 110
Gly Tyr Tyr Val Asp Gly Met Asp Val Trp Gly Gln Gly Thr Thr Val
115 120 125
Thr Val Ser Ser
130
12
112
PRT
Homo sapiens
PEPTIDE
(1)..(112)
Clone 110 VK
12
Ala Glu Leu Thr Gln Ser Pro Asp Ser Leu Ala Met Ser Leu Gly Glu
1 5 10 15
Arg Ala Ser Ile Asn Cys Lys Ser Ser Arg Ser Leu Leu Tyr Ser Ser
20 25 30
Asn Asn Lys Asn Tyr Leu Ala Trp Tyr Gln Gln Lys Ser Gly His Pro
35 40 45
Pro Lys Leu Leu Ile Tyr Trp Ala Ser Thr Arg Glu Ser Gly Val Pro
50 55 60
Asp Arg Phe Asn Gly Ser Gly Ser Gly Thr Asp Phe Thr Leu Thr Ile
65 70 75 80
Ser Ser Leu Gln Ala Glu Asp Val Ala Val Tyr Phe Cys Gln Gln Tyr
85 90 95
Tyr Ser Ser Pro Leu Thr Phe Gly Gly Gly Thr Lys Val Glu Ile Lys
100 105 110
13
125
PRT
Homo sapiens
PEPTIDE
(1)..(125)
Clone 46 VH
13
Ala Glu Val Gln Leu Leu Glu Gln Ser Gly Ala Glu Val Lys Lys Pro
1 5 10 15
Gly Ala Ser Val Lys Val Ser Cys Lys Ala Ser Gly Tyr Thr Phe Thr
20 25 30
Lys Tyr Tyr Leu His Trp Val Arg Gln Ala Pro Gly Gln Gly Leu Glu
35 40 45
Trp Met Gly Phe Ile Asn Pro Ser Gly Gly Ser Thr Ser Ser Ala Gln
50 55 60
Lys Phe Gln Gly Arg Ile Ser Met Thr Arg Asp Thr Ser Thr Thr Thr
65 70 75 80
Val Tyr Met Glu Val Asn Ser Val Thr Ser Glu Asp Thr Ala Val Tyr
85 90 95
Tyr Cys Ala Arg Val Gly Arg Leu Gly Val Gly Ala Thr Gly Ala Phe
100 105 110
Asp Leu Trp Gly Gln Gly Thr Met Val Thr Val Ser Ser
115 120 125
14
107
PRT
Homo sapiens
PEPTIDE
(1)..(107)
Clone 46 VK
14
Ala Glu Leu Thr Gln Ser Pro Ser Ser Leu Ser Ala Ser Val Gly Asp
1 5 10 15
Arg Val Thr Ile Thr Cys Gln Ala Ser Gln Asp Ile Asn Tyr Ser Leu
20 25 30
Asn Trp Tyr Gln Gln Lys Pro Gly Lys Pro Pro Lys Leu Leu Ile Tyr
35 40 45
Tyr Ala Ser His Ser Asp Thr Gly Val Pro Ser Arg Phe Ser Gly Gly
50 55 60
Gly Ser Gly Thr Arg Phe Thr Leu Thr Ile Tyr Ser Leu Gln Pro Glu
65 70 75 80
Asp Ile Ala Thr Tyr Tyr Cys Gln His Phe Asp His Val Pro Arg Tyr
85 90 95
Thr Phe Gly Pro Gly Thr Lys Val Asp Leu Lys
100 105
15
128
PRT
Homo sapiens
PEPTIDE
(1)..(128)
Clone 6a5 VH
15
Ala Glu Val Gln Leu Leu Glu Ser Gly Pro Gly Leu Val Lys Pro Ser
1 5 10 15
Gln Thr Leu Ser Leu Thr Cys Ala Ile Ser Gly Asp Asn Val Ser Arg
20 25 30
Lys Ser Ala Ala Trp Asn Trp Ile Arg Gln Ser Pro Ser Arg Gly Leu
35 40 45
Glu Trp Leu Gly Arg Thr Tyr His Met Ser Lys Trp Tyr Ser Val Tyr
50 55 60
Ala Thr Ser Leu Lys Ser Arg Ile Asn Ile Asn Val Asp Thr Ser Arg
65 70 75 80
Asn Gln Phe Ala Leu Gln Leu Arg Ser Val Thr Pro Glu Asp Thr Ala
85 90 95
Val Tyr Tyr Cys Ala Arg Glu Gly Pro Glu Trp Ala Val Gly Gly Thr
100 105 110
Tyr Gly Met Asp Val Trp Gly Gln Gly Thr Thr Val Thr Val Ser Ser
115 120 125
16
106
PRT
Homo sapiens
PEPTIDE
(1)..(106)
Clone 6a5 VK
16
Ala Glu Leu Thr Gln Ser Pro Asp Thr Leu Ser Leu Ser Pro Gly Glu
1 5 10 15
Arg Ala Thr Leu Ser Cys Arg Ala Ser Gln Ser Val Asn Asn Asn Tyr
20 25 30
Leu Ala Trp Tyr Gln Gln Lys Pro Gly Gln Ala Pro Arg Leu Leu Ile
35 40 45
Tyr Gly Ala Ser Ser Arg Ala Thr Gly Ile Pro Asp Arg Phe Ser Gly
50 55 60
Ser Gly Ser Glu Thr Asp Phe Thr Leu Thr Ile Ser Arg Leu Glu Pro
65 70 75 80
Glu Asp Phe Ala Val Tyr Tyr Cys Gln Gln Tyr Asp Ser Ser Arg Thr
85 90 95
Phe Gly Gln Gly Thr Lys Val Glu Ile Lys
100 105
17
130
PRT
Homo sapiens
PEPTIDE
(1)..(130)
Clone 2a2 VH
17
Ala Glu Val Gln Leu Leu Glu Gln Ser Gly Ala Glu Val Lys Lys Pro
1 5 10 15
Gly Ala Ser Val Lys Val Ser Cys Lys Ala Ser Gly Tyr Thr Phe Thr
20 25 30
Gly Tyr Tyr Met His Trp Val Arg Gln Ala Pro Gly Gln Gly Leu Glu
35 40 45
Trp Met Gly Trp Ile Asn Pro Glu Ser Gly Ala Thr Asn Tyr Ala Gln
50 55 60
Asn Phe Gln Gly Arg Val Thr Met Thr Thr Asp Thr Ser Met Arg Thr
65 70 75 80
Ala Tyr Ile Glu Val Ser Arg Leu Arg Ser Asp Asp Thr Ala Val Tyr
85 90 95
Phe Cys Ala Arg Gly Gly Ala Phe Cys Thr Gly Gly Thr Cys Tyr Phe
100 105 110
Ala Ile Tyr Gly Met Asp Val Trp Gly Gln Gly Thr Ala Val Ile Val
115 120 125
Ser Ser
130
18
110
PRT
Homo sapiens
PEPTIDE
(1)..(110)
Clone 2a2 VK
18
Ala Glu Leu Thr Gln Ser Pro Leu Ser Leu Pro Val Thr Pro Gly Glu
1 5 10 15
Pro Ala Ser Ile Ser Cys Arg Ser Ser Gln Ser Leu Leu His Thr Asn
20 25 30
Gly Tyr Asn Tyr Leu Asp Trp Tyr Leu Gln Lys Pro Gly Gln Ser Pro
35 40 45
Gln Leu Leu Ile Tyr Leu Gly Ser Asn Arg Ala Ser Gly Val Pro Asp
50 55 60
Arg Phe Ser Gly Ser Gly Ser Gly Thr Asp Phe Thr Leu Lys Ile Ser
65 70 75 80
Arg Val Glu Ala Glu Asp Val Gly Val Tyr Tyr Cys Met Gln Ala Leu
85 90 95
Gln Thr Leu Thr Phe Gly Gly Gly Thr Lys Val Glu Ile Lys
100 105 110
19
121
PRT
Homo sapiens
PEPTIDE
(1)..(121)
Clone 2a4 VH
19
Ala Glu Val Gln Leu Leu Glu Ser Gly Gly Gly Leu Val Lys Pro Gly
1 5 10 15
Gly Ser Leu Arg Leu Ser Cys Ala Ala Ser Gly Phe Thr Phe Ser Asn
20 25 30
Ala Trp Met Ser Trp Val Arg Gln Ala Pro Gly Lys Gly Leu Glu Trp
35 40 45
Val Gly Arg Ile Lys Ser Lys Thr Asp Gly Gly Thr Ile Asp Tyr Ala
50 55 60
Ala Pro Val Lys Gly Arg Phe Thr Ile Ser Arg Asp Asp Ser Lys Asn
65 70 75 80
Thr Leu Tyr Leu Gln Met Asn Ser Leu Lys Thr Glu Asp Thr Ala Val
85 90 95
Tyr Tyr Cys Thr Thr Trp Asp Gly Asp His Ala Val Asp Tyr Trp Gly
100 105 110
Gln Gly Thr Leu Val Thr Val Ser Ser
115 120
20
106
PRT
Homo sapiens
PEPTIDE
(1)..(106)
Clone 2a4 VK
20
Ala Glu Leu Thr Gln Ser Pro Ser Ser Leu Ser Ala Ser Ile Gly Asp
1 5 10 15
Arg Val Ala Ile Ser Cys Gln Ala Ser Gln Asp Ile Gly Asn Tyr Leu
20 25 30
Asn Trp Tyr Gln Gln Lys Pro Gly Lys Ala Pro Arg Leu Leu Ile Tyr
35 40 45
Asp Ala Ser Asn Leu Glu Ala Gly Val Pro Ser Arg Phe Ser Gly Ser
50 55 60
Gly Ser Gly Thr Asp Phe Thr Leu Thr Ile Ser Thr Leu Gln Pro Glu
65 70 75 80
Asp Phe Ala Thr Phe Tyr Cys Gln Gln Thr Asp Ser Thr Pro Tyr Thr
85 90 95
Phe Gly Gln Gly Thr Lys Leu Glu Ile Arg
100 105
21
120
PRT
Homo sapiens
PEPTIDE
(1)..(120)
Clone 2a5 VH
21
Ala Glu Val Gln Leu Leu Glu Ser Gly Pro Gly Leu Val Lys Pro Ser
1 5 10 15
Glu Thr Leu Ser Leu Thr Cys Thr Val Ser Thr Gly Ser Ile Ser Gly
20 25 30
Tyr Phe Trp Ser Trp Ile Arg Gln Pro Pro Gly Lys Gly Leu Glu Trp
35 40 45
Ile Ala Tyr Ile His Asn Ser Gly Asn Thr Asn Tyr Asn Pro Ser Leu
50 55 60
Arg Ser Arg Val Thr Val Ser Ile Asp Thr Ser Lys Asn Gln Phe Ser
65 70 75 80
Leu Lys Leu Thr Ser Val Thr Ala Ala Asp Thr Ala Val Tyr Tyr Cys
85 90 95
Ala Arg Asp Gly Gly Gly Trp Asp Thr Tyr Leu Asp Ser Trp Gly Gln
100 105 110
Gly Phe Leu Val Thr Val Ser Ser
115 120
22
105
PRT
Homo sapiens
PEPTIDE
(1)..(105)
Clone 2a5 VK
22
Ala Glu Leu Thr Gln Ser Pro Ser Ser Leu Ser Ala Ser Val Gly Asp
1 5 10 15
Arg Val Thr Ile Thr Cys Arg Ala Ser Gln Thr Val Ser Ser Tyr Leu
20 25 30
Asn Trp Tyr Gln Gln Lys Pro Gly Lys Ala Pro Lys Val Leu Ile Tyr
35 40 45
Gly Ile Ser Thr Leu Gln Ser Gly Val Pro Ser Arg Phe Ser Gly Ser
50 55 60
Gly Ser Glu Thr Asp Phe Thr Leu Thr Ile Ser Asn Leu Gln Pro Glu
65 70 75 80
Asp Phe Ala Ile Tyr Tyr Cys Gln Gln Ser Tyr Ser Ser Arg Thr Phe
85 90 95
Gly Gln Gly Thr Lys Val Glu Ile Lys
100 105
23
120
PRT
Homo sapiens
PEPTIDE
(1)..(120)
Clone 2a13 VH
23
Ala Glu Val Gln Leu Leu Glu Ser Gly Pro Gly Leu Val Lys Pro Ser
1 5 10 15
Glu Thr Leu Ser Leu Thr Cys Thr Val Ser Gly Gly Ser Ile Ser Asp
20 25 30
Tyr Tyr Trp Ser Trp Ile Arg Gln Pro Pro Gly Lys Gly Leu Glu Trp
35 40 45
Ile Gly His Thr Tyr Asp Asn Gly Gly Thr Lys Tyr Asn Pro Ser Leu
50 55 60
Lys Ser Arg Ala Ser Ile Ser Val Asp Thr Ser Lys Asn Gln Val Ser
65 70 75 80
Leu Arg Leu Thr Ser Val Thr Ala Ala Asp Thr Ala Val Tyr Tyr Cys
85 90 95
Ala Thr Ala Phe Leu Asp Asn Ser Gly Trp Tyr Thr Phe Asp Ser Trp
100 105 110
Gly Gln Gly Ser Leu Val Thr Val
115 120
24
109
PRT
Homo sapiens
PEPTIDE
(1)..(109)
Clone 2a13 VK
24
Ala Glu Leu Thr Gln Ser Pro Ser Ser Val Ser Ala Ser Val Arg Asp
1 5 10 15
Arg Val Thr Ile Thr Cys Arg Ala Ser Gln Gly Ile Ser Thr Trp Leu
20 25 30
Ala Trp Tyr Gln Gln Lys Pro Gly Lys Ala Pro Lys Leu Leu Ile Tyr
35 40 45
Ala Ala Ser Thr Leu Gln Ser Gly Val Pro Ser Arg Phe Ser Gly Ser
50 55 60
Gly Ser Gly Thr Asp Phe Thr Leu Thr Ile Gly Ser Leu Gln Pro Glu
65 70 75 80
Asp Val Ala Thr Tyr Tyr Cys Gln Gln Ala Asn Ser Phe Pro Pro Gly
85 90 95
Ala Leu Thr Phe Gly Gly Gly Thr Lys Val Glu Val Lys
100 105
25
121
PRT
Homo sapiens
PEPTIDE
(1)..(121)
Clone 2a14 VH
25
Ala Glu Val Gln Leu Leu Glu Gln Ser Gly Gly Gly Val Val Gln Pro
1 5 10 15
Gly Arg Ser Leu Arg Leu Ser Cys Ala Ala Ser Gly Phe Thr Phe Ser
20 25 30
Thr Tyr Ala Met His Trp Val Arg Gln Ala Pro Gly Lys Gly Leu Glu
35 40 45
Trp Val Ala Val Ile Ser His Asp Gly Ser Asn Lys Phe Tyr Ala Asp
50 55 60
Ser Val Lys Gly Arg Phe Thr Ile Ser Arg Asp Ser Ser Lys Asn Thr
65 70 75 80
Leu Tyr Leu Gln Met Asn Ser Leu Arg Pro Gly Asp Thr Ala Val Tyr
85 90 95
Tyr Cys Ser Arg Trp Asp Arg Arg Ala Glu Tyr Phe Gln Asp Trp Gly
100 105 110
Gln Gly Thr Leu Val Thr Val Ser Ser
115 120
26
106
PRT
Homo sapiens
PEPTIDE
(1)..(106)
Clone 2a14 VK
26
Ala Glu Leu Thr Gln Ser Pro Ala Phe Met Ser Ala Thr Pro Gly Asp
1 5 10 15
Lys Val Asn Ile Ser Cys Lys Ala Ser Gln Asp Ile Asp Asp Asp Met
20 25 30
Asn Trp Tyr Gln Gln Lys Pro Gly Glu Ala Ala Ile Phe Ile Ile Gln
35 40 45
Glu Ala Thr Thr Leu Val Pro Gly Ile Pro Pro Arg Phe Ser Gly Ser
50 55 60
Gly Tyr Gly Thr Asp Phe Thr Leu Thr Ile Asn Asn Ile Glu Ser Glu
65 70 75 80
Asp Ala Ala Tyr Tyr Phe Cys Leu Gln His Asp Asn Phe Pro Leu Thr
85 90 95
Phe Gly Gln Gly Thr Lys Val Glu Ile Lys
100 105
27
118
PRT
Homo sapiens
PEPTIDE
(1)..(118)
Clone 2a23 VH
27
Ala Glu Val Gln Leu Leu Glu Ser Gly Ala Gly Val Val Gln Pro Gly
1 5 10 15
Lys Ser Leu Thr Leu Ser Cys Val Gly Ser Gly Phe Thr Phe Ser Ile
20 25 30
Tyr Ala Met His Trp Val Arg Gln Ala Pro Gly Lys Gly Leu Glu Trp
35 40 45
Val Ala Val Leu Ser Ser Asp Gly Ser Asn Asp Tyr Tyr Ala Asp Ser
50 55 60
Val Lys Gly Arg Phe Ser Ile Phe Arg Asp Thr Ser Lys Asn Ser Leu
65 70 75 80
Asn Leu Leu Met Asn Asn Val Arg Gly Glu Asp Thr Ala Val Tyr Tyr
85 90 95
Cys Ala Arg Asp Gly Asp Gly Ser Phe Phe Tyr Trp Gly Gln Gly Thr
100 105 110
Leu Val Thr Val Ser Ser
115
28
106
PRT
Homo sapiens
PEPTIDE
(1)..(106)
Clone 2a23 VK
28
Ala Glu Leu Thr Gln Ser Pro Ala Phe Met Ser Ala Thr Pro Gly Asp
1 5 10 15
Lys Val Asn Ile Ser Cys Lys Ala Ser Gln Asp Ile Asp Asp Asp Met
20 25 30
Asn Trp Tyr Gln Gln Lys Pro Gly Glu Ala Ala Ile Phe Ile Ile Gln
35 40 45
Glu Ala Thr Thr Leu Val Pro Gly Ile Pro Pro Arg Phe Ser Gly Ser
50 55 60
Gly Tyr Gly Thr Asp Phe Thr Leu Thr Ile Asn Asn Ile Glu Ser Glu
65 70 75 80
Asp Ala Ala Tyr Tyr Phe Cys Leu Gln His Asp Asn Phe Pro Leu Thr
85 90 95
Phe Gly Gln Gly Thr Lys Val Glu Ile Lys
100 105
29
118
PRT
Homo sapiens
PEPTIDE
(1)..(118)
Clone 2a25 VH
29
Ala Glu Val Gln Leu Leu Glu Gln Ser Gly Ala Glu Val Lys Lys Pro
1 5 10 15
Gly Ala Ser Val Lys Val Ser Cys Lys Ala Ser Gly Tyr Met Phe Thr
20 25 30
Cys Tyr Tyr Met His Trp Val Arg Gln Ala Pro Gly Gln Gly Leu Glu
35 40 45
Trp Met Gly Met Val Asn Pro Thr Gly Gly Ser Ser Ser Tyr Ala Gln
50 55 60
Lys Phe Gln Gly Arg Val Thr Met Thr Lys Gly His Val Thr Ser Thr
65 70 75 80
Val Tyr Met Glu Leu Ser Ser Leu Arg Ser Glu Asp Thr Ala Val Tyr
85 90 95
Tyr Cys Ala Thr Gly Met Val Arg Gly Asp Glu Trp Gly Gln Gly Thr
100 105 110
Leu Val Thr Val Ser Ser
115
30
106
PRT
Homo sapiens
PEPTIDE
(1)..(106)
Clone 2a25 VK
30
Ala Glu Leu Thr Gln Ser Pro Ser Phe Ser Ser Ala Ser Val Gly Asp
1 5 10 15
Arg Val Thr Ile Thr Cys Arg Ala Ser His Gly Ile Ser Ser His Leu
20 25 30
Ala Trp Phe Gln His Lys Pro Gly Lys Ala Pro Asn Leu Leu Ile Tyr
35 40 45
Ala Ala Ser Thr Leu Gln Ser Gly Val Pro Ser Arg Phe Ser Gly Ser
50 55 60
Gln Ser Gly Thr Glu Phe Thr Leu Thr Ile Thr Ser Leu His Pro Glu
65 70 75 80
Asp Phe Ala Thr Tyr Tyr Cys Gln Gln Leu Tyr Thr Trp Pro Met Gly
85 90 95
Phe Gly Gln Gly Thr Arg Leu Glu Ile Thr
100 105
31
126
PRT
Homo sapiens
PEPTIDE
(1)..(126)
Clone 2a30 VH
31
Ala Glu Val Gln Leu Leu Glu Gln Ser Gly Gly Gly Leu Val Gln Pro
1 5 10 15
Gly Gly Ser Leu Arg Leu Ser Cys Thr Ala Ser Gly Phe Thr Leu Thr
20 25 30
Asp Tyr Ser Met Asp Trp Val Arg Gln Ala Pro Gly Lys Gly Pro Glu
35 40 45
Trp Val Gly Arg Ser Arg Asn Lys Ala Asn Ile Tyr Thr Thr Glu Tyr
50 55 60
Ala Ala Ser Val Lys Gly Arg Phe Val Ile Ser Arg Asp Asp Ser Glu
65 70 75 80
Asn Ser Val Tyr Leu Gln Met Asn Asn Val Lys Met Asp Asp Thr Ala
85 90 95
Val Tyr Tyr Cys Ala Arg Gly Glu Gly Ile Phe Tyr Gly Ser Gly Ser
100 105 110
Leu Asp Leu Trp Gly Gln Gly Ala Val Val Thr Val Ser Ser
115 120 125
32
106
PRT
Homo sapiens
PEPTIDE
(1)..(106)
Clone 2a30 VK
32
Ala Glu Leu Thr Gln Ser Pro Ser Ser Leu Ser Ala Ser Val Gly Asp
1 5 10 15
Arg Val Thr Ile Thr Cys Arg Ser Ser Gln Ser Ile Ser Asn Ser Leu
20 25 30
His Trp Phe Gln Gln Glu Pro Gly Lys Ala Pro Lys Leu Leu Ile Tyr
35 40 45
Ala Ala Ser Thr Leu Gln Ser Gly Val Pro Ser Arg Phe Ser Gly Ser
50 55 60
Gly Ser Gly Thr Asp Phe Thr Leu Ile Ile Thr Gly Leu Gln Pro Glu
65 70 75 80
Asp Phe Ala Thr Tyr Tyr Cys Gln Gln Ser Pro Arg Thr Pro Leu Thr
85 90 95
Phe Gly Gly Gly Thr Lys Val Glu Ile Arg
100 105
33
126
PRT
Homo sapiens
PEPTIDE
(1)..(126)
Clone 2a32 VH
33
Ala Glu Val Gln Leu Leu Glu Gln Ser Gly Gly Asp Leu Val Lys Pro
1 5 10 15
Gly Gly Ser Leu Arg Leu Ser Cys Ala Ala Ser Gly Phe Thr Phe Thr
20 25 30
Asp Tyr Tyr Met Asn Trp Ile Arg Gln Ala Pro Gly Lys Gly Leu Glu
35 40 45
Trp Ile Ala Tyr Ile Ser Ile Gly Ser Asp Asp Thr Lys Tyr Ala Ala
50 55 60
Ser Val Lys Gly Arg Phe Ser Ile Ser Arg Asp Asn Ala Lys Asn Ser
65 70 75 80
Leu Tyr Leu Gln Met Asn Ser Leu Arg Val Glu Asp Thr Ala Val Tyr
85 90 95
Tyr Cys Gly Arg Gly Gly Gly Tyr Cys Ser Gly Gly Asn Cys Tyr Ser
100 105 110
Ser Asp Tyr Trp Gly Gln Gly Ala Leu Val Thr Val Ser Ser
115 120 125
34
106
PRT
Homo sapiens
PEPTIDE
(1)..(106)
Clone 2a32 VK
34
Ala Glu Leu Thr Gln Ser Pro Ser Ser Leu Ser Ala Phe Thr Gly Asp
1 5 10 15
Arg Val Ser Ile Thr Cys Arg Ala Ser Gln Gly Ile Gly Asn Ser Leu
20 25 30
Ala Trp Tyr Gln Gln Lys Pro Gly His Val Pro Lys Val Leu Ile Tyr
35 40 45
Asp Ala Ser Thr Leu Ser Ser Gly Ala Pro Ser Arg Phe Ser Gly Ser
50 55 60
Gly Ser Gly Thr Asp Phe Thr Leu Thr Ile Ser Gly Leu Gln Pro Glu
65 70 75 80
Asp Val Ala Thr Tyr Tyr Cys Gln Lys Tyr Lys Ser Ala Pro Leu Thr
85 90 95
Phe Gly Gly Gly Thr Lys Val Glu Ile Arg
100 105
35
131
PRT
Homo sapiens
PEPTIDE
(1)..(131)
Clone 2a33 VH
35
Ala Glu Val Gln Leu Leu Glu Gln Ser Gly Gly Gly Leu Val Gln Pro
1 5 10 15
Gly Arg Ser Leu Arg Leu Ser Cys Ala Ala Ser Gly Phe Thr Phe Asp
20 25 30
Asp Tyr Ala Met His Trp Val Arg Gln Thr Pro Gly Lys Gly Leu Glu
35 40 45
Trp Val Ser Gly Ile Gly Trp Asn Ser Gly Thr Ile Glu Tyr Ala Asp
50 55 60
Ser Val Lys Gly Arg Phe Thr Ile Ser Arg Asp Asn Ala Lys Asn Ser
65 70 75 80
Leu Tyr Leu Gln Met Asn Ser Leu Arg Pro Glu Asp Thr Ala Leu Tyr
85 90 95
Tyr Cys Ala Lys Asp Leu His Ser Phe Gly Tyr Cys Ser Gly Arg Ser
100 105 110
Cys Tyr Phe His Pro Phe Asp Tyr Trp Gly Gln Gly Thr Leu Val Thr
115 120 125
Val Ser Ser
130
36
112
PRT
Homo sapiens
PEPTIDE
(1)..(112)
Clone 2a33 VK
36
Ala Glu Leu Thr Gln Ser Pro Asp Ser Leu Ala Val Ser Leu Gly Glu
1 5 10 15
Arg Ala Thr Ile Asn Cys Lys Ser Ser Gln Ser Val Leu Ser Ser Ser
20 25 30
Asn Asn Lys Asn Tyr Leu Ala Trp Tyr Gln Gln Lys Pro Arg Gln Pro
35 40 45
Pro Lys Leu Leu Ile Tyr Trp Ala Ser Thr Arg Glu Ser Gly Val Pro
50 55 60
Asp Arg Phe Ser Gly Ser Gly Ser Gly Thr Asp Phe Thr Leu Thr Ile
65 70 75 80
Ser Ser Leu Gln Ala Glu Asp Val Ala Val Tyr Tyr Cys Gln Gln Phe
85 90 95
Tyr Ser Thr Pro Pro Thr Phe Gly Gly Gly Thr Lys Val Glu Ile Arg
100 105 110
37
118
PRT
Homo sapiens
PEPTIDE
(1)..(118)
Clone 2a37 VH
37
Ala Glu Val Gln Leu Leu Glu Ser Gly Gly Gly Leu Val Gln Pro Gly
1 5 10 15
Arg Ser Leu Arg Leu Ser Cys Ala Ala Ser Gly Phe Thr Phe Ser Asn
20 25 30
Ser Asp Met His Trp Val Arg Gln Ala Pro Gly Lys Gly Leu Glu Trp
35 40 45
Val Thr Val Ser Ser Arg Asp Gly Tyr Asp Asn Tyr Tyr Ala Asp Ser
50 55 60
Val Arg Gly Arg Phe Thr Ile Ser Arg Asp Asn Ser Lys Asn Thr Leu
65 70 75 80
Tyr Leu Gln Met Asn Thr Leu Arg Ala Glu Asp Thr Ala Val Tyr Tyr
85 90 95
Cys Ala Lys Arg Arg Gly Tyr Ala Phe Asp Ile Trp Gly Gln Gly Thr
100 105 110
Met Val Thr Val Ser Ser
115
38
106
PRT
Homo sapiens
PEPTIDE
(1)..(106)
Clone 2a37 VK
38
Ala Glu Leu Thr Gln Ser Pro Ser Ser Leu Ser Ala Ser Val Gly Asp
1 5 10 15
Arg Val Thr Ile Thr Cys Arg Ala Ser Gln Ser Ile Asn Thr Tyr Leu
20 25 30
Asn Trp Tyr Gln Gln Lys Pro Gly Lys Ala Pro Glu Leu Leu Ile Tyr
35 40 45
Gly Ala Ser Ser Leu Gln Ser Gly Val Pro Ser Arg Phe Ser Gly Ser
50 55 60
Gly Ser Gly Thr Asp Phe Thr Leu Thr Ile Thr Ser Leu Gln Ala Glu
65 70 75 80
Asp Phe Ala Ser Tyr Phe Cys Gln Gln Ser Asp Ser Thr Pro Arg Thr
85 90 95
Phe Gly Gln Gly Thr Lys Val Glu Ile Lys
100 105
39
128
PRT
Homo sapiens
PEPTIDE
(1)..(128)
Clone 2a40 VH
39
Ala Glu Val Gln Leu Leu Glu Gln Ser Gly Gly Gly Leu Val Lys Pro
1 5 10 15
Gly Gly Ser Leu Arg Leu Ser Cys Thr Ala Ser Gly Phe Thr Phe Ser
20 25 30
Gly Phe Thr Phe Ser Asp His Tyr Met Ser Trp Ile Arg Gln Ala Pro
35 40 45
Gly Lys Gly Leu Glu Leu Val Ser Tyr Ile Ile Ser Asn Gly Tyr Thr
50 55 60
Asn Tyr Pro Asp Ser Val Lys Gly Arg Phe Thr Val Ser Arg Asp Asn
65 70 75 80
Ala Arg Lys Ser Leu Tyr Leu Gln Met Asn Ser Leu Arg Val Glu Asp
85 90 95
Thr Ala Ile Tyr Tyr Cys Ala Arg Gly Leu Ser Pro Ser Ile Ala Gly
100 105 110
Asp Gly Phe Asp Ile Trp Gly Gln Gly Thr Met Val Thr Val Ser Ser
115 120 125
40
106
PRT
Homo sapiens
PEPTIDE
(1)..(106)
Clone 2a40 VK
40
Ala Glu Leu Thr Gln Ser Pro Ala Phe Met Ser Ala Thr Pro Gly Asp
1 5 10 15
Lys Val Asn Ile Ser Cys Lys Ala Ser Gln Asp Ile Asp Asp Asp Met
20 25 30
Asn Trp Tyr Gln Gln Lys Pro Gly Glu Ala Ala Ile Phe Ile Ile Gln
35 40 45
Glu Ala Thr Thr Leu Val Pro Gly Ile Pro Pro Arg Phe Ser Gly Ser
50 55 60
Gly Tyr Gly Thr Asp Phe Thr Leu Thr Ile Asn Asn Ile Glu Ser Glu
65 70 75 80
Asp Ala Ala Tyr Tyr Phe Cys Leu Gln His Asp Asn Phe Pro Leu Thr
85 90 95
Phe Gly Gln Gly Thr Lys Val Glu Ile Lys
100 105
41
116
PRT
Homo sapiens
PEPTIDE
(1)..(116)
Clone 2b1 VH
41
Ala Glu Val Gln Leu Leu Glu Ser Gly Pro Arg Leu Val Lys Pro Ser
1 5 10 15
Gln Thr Leu Ser Leu Thr Cys Thr Val Ser Gly Asp Ser Leu Asn Asn
20 25 30
Ala Ser His Tyr Trp Ala Trp Ile Arg Gln Pro Ala Gly Lys Gly Leu
35 40 45
Glu Trp Ile Gly Arg Ile His Arg Gly Gly Ser Thr Asn Tyr Asn Pro
50 55 60
Ser Leu Gln Ser Arg Val Thr Ile Ser Met Asp Glu Ser Lys Asn Gln
65 70 75 80
Phe Ser Leu Arg Leu Asn Ser Val Thr Ala Ala Asp Thr Ala Val Tyr
85 90 95
Tyr Cys Ala Arg Asp Pro Pro Lys Ala Trp Gly Pro Gly Ile Leu Val
100 105 110
Thr Val Ser Ser
115
42
105
PRT
Homo sapiens
PEPTIDE
(1)..(105)
Clone 2b1 VK
42
Ala Glu Leu Thr Gln Ser Pro Ser Ser Leu Ser Ala Ser Val Gly Asp
1 5 10 15
Arg Val Thr Ile Ala Cys Arg Ala Ser Gln Ser Ile Ser Asn His Leu
20 25 30
Asn Trp Tyr Gln Gln Lys Pro Gly Lys Ala Pro Lys Val Leu Ile Tyr
35 40 45
Ala Ala Ser Ser Leu Gln Ser Gly Val Pro Ser Arg Phe Ser Gly Ser
50 55 60
Gly Ser Gly Thr Asp Phe Thr Leu Thr Ile Ser Ser Leu Gln Pro Glu
65 70 75 80
Asp Phe Ala Ile Tyr Tyr Cys Gln Gln Ser Tyr Ser Asn Ala Asp Phe
85 90 95
Gly Pro Gly Thr Lys Val Asp Ile Lys
100 105
43
121
PRT
Homo sapiens
PEPTIDE
(1)..(121)
Clone 2b3 VH
43
Ala Glu Val Gln Leu Leu Glu Ser Gly Ala Glu Val Lys Lys Pro Gly
1 5 10 15
Ala Ser Val Thr Val Ser Cys Lys Ala Ser Gly Tyr Ser Phe Ser Asp
20 25 30
Tyr Tyr Ile His Trp Val Arg Gln Ala Pro Gly Gln Gly Leu Glu Trp
35 40 45
Met Gly Ile Ile Asn Pro Ser Ala Gly Thr Thr Thr Tyr Lys Gln Lys
50 55 60
Phe Gln His Arg Val Thr Leu Thr Arg Asp Thr Ser Thr Asn Thr Ala
65 70 75 80
Tyr Met Lys Leu Tyr Asn Leu Thr Pro Asp Asp Thr Ala Ile Phe Phe
85 90 95
Cys Ala Arg Gly Ser Gly Gly Ser Arg Ser Glu Tyr Asp Tyr Trp Gly
100 105 110
Gln Gly Thr Leu Val Thr Val Ser Ser
115 120
44
106
PRT
Homo sapiens
PEPTIDE
(1)..(106)
Clone 2b3 VK
44
Ala Glu Leu Thr Gln Ser Pro Ser Ser Leu Ser Ala Ser Val Gly Asp
1 5 10 15
Gly Val Thr Ile Thr Cys Arg Ala Ser Gln Ser Ile Ser Thr Tyr Leu
20 25 30
Asn Trp Tyr Gln Gln Lys Pro Gly Lys Ala Pro Lys Leu Leu Met Tyr
35 40 45
Ala Ala Ser Thr Leu Gln Ser Gly Val Pro Ser Arg Phe Ser Gly Ser
50 55 60
Gly Ser Gly Thr Asp Phe Thr Leu Thr Ile Ser Ser Leu Gln Pro Glu
65 70 75 80
Asp Phe Ala Ala Tyr Tyr Cys Gln Gln Ala Arg Ser Phe Pro Tyr Thr
85 90 95
Phe Gly Gln Gly Thr Arg Leu Glu Ile Arg
100 105
45
121
PRT
Homo sapiens
PEPTIDE
(1)..(121)
Clone 2b4 VH
45
Ala Glu Val Gln Leu Leu Glu Ser Gly Gly Glu Val Lys Lys Pro Gly
1 5 10 15
Ser Ser Val Lys Val Ser Cys Lys Ala Ser Gly Gly Pro Phe Ser Ser
20 25 30
Tyr Ala Ile His Trp Val Arg Gln Ala Pro Gly Gln Gly Leu Glu Trp
35 40 45
Met Gly Ala Ile Ile Pro Phe Leu Gly Arg Ala Lys Tyr Ala Gln Lys
50 55 60
Phe Glu Gly Arg Val Thr Ile Thr Ala Asp Gly Ser Met Ser Thr Ala
65 70 75 80
Tyr Met Glu Val Ser Ser Leu Arg Ser Asp Asp Thr Ala Met Tyr Tyr
85 90 95
Cys Ala Arg Asp Arg Gly Glu Leu Leu Leu Arg Met Asp Val Trp Gly
100 105 110
Gln Gly Thr Ala Val Thr Val Ser Ser
115 120
46
106
PRT
Homo sapiens
PEPTIDE
(1)..(106)
Clone 2b4 VK
46
Ala Glu Leu Thr Gln Ser Pro Ala Phe Met Ser Ala Thr Pro Gly Asp
1 5 10 15
Lys Val Asn Ile Ser Cys Lys Ala Ser Gln Asp Ile Asp Asp Asp Met
20 25 30
Asn Trp Tyr Gln Gln Lys Pro Gly Glu Ala Ala Ile Phe Ile Ile Gln
35 40 45
Glu Ala Thr Thr Leu Val Pro Gly Ile Pro Pro Arg Phe Ser Gly Ser
50 55 60
Gly Tyr Gly Thr Asp Phe Thr Leu Thr Ile Asn Asn Ile Glu Ser Glu
65 70 75 80
Asp Ala Ala Tyr Tyr Phe Cys Leu Gln His Asp Asn Phe Pro Leu Thr
85 90 95
Phe Gly Gln Gly Thr Lys Val Glu Ile Lys
100 105
47
128
PRT
Homo sapiens
PEPTIDE
(1)..(128)
Clone 2b5 VH
47
Ala Glu Val Gln Leu Leu Glu Ser Gly Gly Gly Val Val Gln Pro Gly
1 5 10 15
Arg Ser Leu Arg Leu Ser Cys Ala Ala Ser Gly Phe Thr Leu Ser Thr
20 25 30
Tyr Ala Met His Trp Val Arg Gln Ala Pro Gly Arg Gly Leu Glu Trp
35 40 45
Val Ala Val Ile Ser Tyr Asp Gly Asp His Lys Phe Tyr Ala Asp Ser
50 55 60
Met Lys Gly Arg Phe Ala Ile Ser Arg Asp Thr Ser Thr Asn Thr Leu
65 70 75 80
Tyr Leu Glu Val Asn Ser Leu Lys Ile Glu Asp Thr Ala Val Tyr Tyr
85 90 95
Cys Ala Arg Asp Arg Asp Arg Arg Gly Gly Tyr Val Phe Ser Thr Thr
100 105 110
Gly Gly Leu Asp Ser Trp Gly Gln Gly Thr Leu Val Thr Val Ser Ser
115 120 125
48
111
PRT
Homo sapiens
PEPTIDE
(1)..(111)
Clone 2b5 VK
48
Ala Glu Leu Thr Gln Ser Pro Leu Ser Leu Ala Val Thr Pro Gly Glu
1 5 10 15
Pro Ala Ser Ile Ser Cys Arg Thr Ser Gln Ser Leu Leu His Ser Asn
20 25 30
Gly Tyr Thr Tyr Leu Asp Trp Tyr Leu Gln Lys Pro Gly Gln Ser Pro
35 40 45
Gln Leu Leu Ile Tyr Leu Ala Ser Asn Arg Ala Ser Gly Val Pro Asp
50 55 60
Arg Phe Ser Gly Ser Gly Ser Gly Thr Asp Phe Thr Leu Glu Ile Ser
65 70 75 80
Arg Val Glu Ala Glu Asp Val Gly Val Tyr Tyr Cys Met Gln Pro Leu
85 90 95
Gln Thr Pro Val Thr Phe Gly Gln Gly Thr Lys Val Glu Val Lys
100 105 110
49
123
PRT
Homo sapiens
PEPTIDE
(1)..(123)
Clone 2b7 VH
49
Ala Glu Val Gln Leu Leu Glu Gln Ser Gly Ala Glu Val Lys Lys Pro
1 5 10 15
Gly Glu Ser Leu Lys Ile Ser Cys Arg Ala Ser Gly Tyr Ser Phe Ser
20 25 30
Leu Phe Trp Val Ala Trp Val Arg Gln Met Pro Gly Gln Gly Leu Glu
35 40 45
Trp Met Ala Ile Ile Tyr Pro Gly Asp Ser Asp Thr Thr Tyr Ser Pro
50 55 60
Ser Phe Glu Gly Gln Val Asn Val Ser Val Asp Lys Pro Ile Ser Thr
65 70 75 80
Ala Tyr Leu Gln Trp Ser Ser Leu Lys Ala Ser Asp Thr Ala Met Tyr
85 90 95
Tyr Cys Ala Arg Arg Arg Ser Ser Asp Arg Arg Asp Ala Phe Asp Ile
100 105 110
Trp Gly Pro Gly Thr Met Val Thr Val Ser Ser
115 120
50
106
PRT
Homo sapiens
PEPTIDE
(1)..(106)
Clone 2b7 VK
50
Ala Glu Leu Thr Gln Ser Pro Ala Phe Met Ser Ala Thr Pro Gly Asp
1 5 10 15
Lys Val Asn Ile Ser Cys Lys Ala Ser Gln Asp Ile Asp Asp Asp Met
20 25 30
Asn Trp Tyr Gln Gln Lys Pro Gly Glu Ala Ala Ile Phe Ile Ile Gln
35 40 45
Glu Ala Thr Thr Leu Val Pro Gly Ile Pro Pro Arg Phe Ser Gly Ser
50 55 60
Gly Tyr Gly Thr Asp Phe Thr Leu Thr Ile Asn Asn Ile Glu Ser Glu
65 70 75 80
Asp Ala Ala Tyr Tyr Phe Cys Leu Gln His Asp Asn Phe Pro Leu Thr
85 90 95
Phe Gly Gln Gly Thr Lys Val Glu Ile Lys
100 105
51
128
PRT
Homo sapiens
PEPTIDE
(1)..(128)
Clone 2b9 VH
51
Ala Glu Val Gln Leu Leu Glu Ser Gly Pro Gly Leu Val Gln Pro Ser
1 5 10 15
Gln Thr Leu Ser Leu Thr Tyr Ala Ile Ser Gly Asp Ser Val Ser Ser
20 25 30
Asn Ser Ala Ala Trp Thr Trp Ile Arg Gln Ser Pro Ser Arg Gly Leu
35 40 45
Glu Trp Leu Gly Met Thr Tyr Tyr Arg Ser Gln Trp Tyr His Glu Tyr
50 55 60
Ala Val Ser Leu Lys Ser Arg Ile Thr Ile Asn Ala Asp Thr Ser Asn
65 70 75 80
Asn Gln Phe Ser Leu Gln Val Asn Ser Val Thr Pro Glu Asp Thr Ala
85 90 95
Leu Tyr Tyr Cys Ala Arg Ala Arg Phe Val Gly Asp Thr Thr Gly Tyr
100 105 110
Tyr Thr Phe Asp Tyr Trp Gly Gln Gly Thr Leu Val Thr Val Ser Ser
115 120 125
52
107
PRT
Homo sapiens
PEPTIDE
(1)..(107)
Clone 2b9 VK
52
Ala Glu Leu Thr Gln Ser Pro Gly Thr Leu Ser Leu Ser Pro Gly Glu
1 5 10 15
Arg Gly Thr Leu Ser Cys Arg Ala Ser Gln Ser Val Ser Ser Ser Tyr
20 25 30
Leu Ala Trp Tyr Gln Gln Lys Ala Gly Gln Ala Pro Arg Leu Leu Ile
35 40 45
Tyr Gly Ala Ser Ser Arg Ala Thr Gly Ile Pro Asp Arg Phe Ser Gly
50 55 60
Ser Gly Ser Gly Thr Asp Phe Thr Leu Thr Ile Ser Arg Leu Glu Pro
65 70 75 80
Glu Asp Phe Ala Val Tyr Tyr Cys Gln Arg Tyr Gly Thr Ser Pro Lys
85 90 95
Thr Phe Gly Gln Gly Thr Lys Val Glu Phe Lys
100 105
53
127
PRT
Homo sapiens
PEPTIDE
(1)..(127)
Clone 2b10 VH
53
Ala Glu Val Gln Leu Leu Glu Ser Gly Gly Gly Val Val Gln Pro Gly
1 5 10 15
Arg Ser Leu Lys Leu Ser Cys Thr Ala Ser Thr Phe Thr Phe Thr Asn
20 25 30
Tyr Ala Met His Trp Val Arg Gln Ala Pro Gly Lys Gly Leu Glu Trp
35 40 45
Val Ala Leu Ile Ser Asn Asp Gly Ser Lys Thr Tyr Tyr Thr Asp Ser
50 55 60
Val Arg Gly Arg Phe Thr Ile Ser Arg Asp Asn Ser Lys Asn Thr Leu
65 70 75 80
Phe Leu Gln Met Asn Ser Leu Arg Thr Glu Asp Thr Ala Val Tyr His
85 90 95
Cys Ala Arg Val Lys Leu Gln Gly Ser Phe Asn Val Tyr Tyr Tyr Tyr
100 105 110
Gly Leu Asp Val Trp Gly Gln Gly Thr Thr Val Thr Val Ser Ser
115 120 125
54
110
PRT
Homo sapiens
PEPTIDE
(1)..(110)
Clone 2b10 VK
54
Ala Glu Leu Thr Gln Ser Pro Leu Ser Leu Pro Val Thr Pro Gly Glu
1 5 10 15
Pro Ala Ser Ile Ser Cys Arg Ser Ser Gln Ser Leu Leu His Ser Asp
20 25 30
Gly Tyr Asn Tyr Phe Asp Trp Tyr Leu Gln Lys Pro Gly Gln Ser Pro
35 40 45
Gln Leu Leu Ile Tyr Leu Gly Ser Asn Arg Ala Ser Gly Val Pro Asp
50 55 60
Arg Phe Ser Gly Ser Gly Ser Asp Thr Asp Phe Thr Leu Lys Ile Ser
65 70 75 80
Arg Val Glu Ala Glu Asp Val Gly Val Tyr Tyr Cys Met Gln Thr Leu
85 90 95
Gln Thr Leu Thr Phe Gly Gly Gly Thr Lys Leu Glu Ile Lys
100 105 110
55
118
PRT
Homo sapiens
PEPTIDE
(1)..(118)
Clone 2b17 VH
55
Ala Glu Val Gln Leu Leu Glu Ser Gly Gly Gly Leu Val Gln Pro Gly
1 5 10 15
Arg Ser Leu Arg Leu Ser Cys Ala Ala Ser Gly Phe Thr Phe Ser Asn
20 25 30
Ser Asp Met His Trp Val Arg Gln Ala Pro Gly Lys Gly Leu Glu Trp
35 40 45
Val Thr Val Ser Ser Arg Asp Gly Tyr Asp Asn Tyr Tyr Ala Asp Ser
50 55 60
Val Arg Gly Arg Phe Thr Ile Ser Arg Asp Asn Ser Lys Asn Thr Leu
65 70 75 80
Tyr Leu Gln Met Asn Thr Leu Arg Ala Glu Asp Thr Ala Val Tyr Tyr
85 90 95
Cys Ala Lys Arg Arg Gly Tyr Ala Phe Asp Ile Trp Gly Gln Gly Thr
100 105 110
Met Val Thr Val Ser Ser
115
56
106
PRT
Homo sapiens
PEPTIDE
(1)..(106)
Clone 2b17 VK
56
Ala Glu Leu Thr Gln Ser Pro Ser Ser Leu Ser Ala Ser Val Gly Asp
1 5 10 15
Arg Val Thr Ile Thr Cys Arg Ala Ser Gln Ser Ile Asn Thr Tyr Leu
20 25 30
Asn Trp Tyr Gln Gln Lys Pro Gly Lys Ala Pro Glu Leu Leu Ile Tyr
35 40 45
Gly Ala Ser Ser Leu Gln Ser Gly Val Pro Ser Arg Phe Ser Gly Ser
50 55 60
Gly Ser Gly Thr Asp Phe Thr Leu Thr Ile Thr Ser Leu Gln Ala Glu
65 70 75 80
Asp Phe Ala Ser Tyr Phe Cys Gln Gln Ser Asp Ser Thr Pro Arg Thr
85 90 95
Phe Gly Gln Gly Thr Lys Val Glu Ile Lys
100 105
|
The present invention relates to materials and methods for treatment of hepatitis C. More closely, the invention relates to human monoclonal antibodies against HCV E1 antigen, to a reagent comprising such antibodies, and to vaccine compositions comprising such antibodies. Futhermore, the invention relates to a method of treating or preventing HCV infection by administration of a vaccine composition comprising the monoclonal antibodies of te invention.
| 0
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is directed to ore handling, and more particularly, to the handling of bauxite ore.
2. Description of the Prior Art
Dusting is a common problem in the mining, storage, and transportation of bauxite ore. For example, in transit, when pulverized bauxite ore is loaded into ships, barges or railroad cars, material is lost by wind erosion or dusting. This bauxite dust is an air pollutant which is possibly hazardous to the environment.
The usual method for reducing bauxite ore dust is to contact the bauxite with a water spray or a water spray including surfactants. The spray is applied via a pressurized spray system or gravity fed. The problem with using a simple water spray or a water spray including surfactants is that bauxite ore is very hydrophilic and becomes tacky and difficult to handle when wet. This tackiness causes the ore to stick to transfer belts and makes it difficult to remove from shipping vehicles, i.e. ships, barges. Thus, water sprays or water sprays including surfactants are not acceptable solutions to the bauxite ore problem since they cause the ore to become tacky and difficult to handle. Accordingly, it would be advantageous to provide an improved method and composition for controlling dusting conditions during the handling of bauxite ore.
SUMMARY OF THE INVENTION
One aspect of the present invention is directed to a method for the suppression of bauxite dust emissions from dry, finely divided bauxite ore. The method includes the step of contacting the bauxite ore with an aqueous solution of a water-soluble vinyl addition polymer selected from the group consisting of nonionic and anionic water-soluble vinyl addition polymers. According to one preferred embodiment of the invention, the bauxite ore is contacted with 0.0001-0.5 pounds of the water-soluble vinyl addition polymer per ton of bauxite. Preferred water-soluble vinyl addition polymer includes polyacrylamide, polyacrylic acid and its water-soluble alkali metal salts, acrylamide-acrylate copolymers, and acrylamide-acrylamido methyl propane sulfonic acid copolymer.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention provides aqueous solutions of water-soluble, vinyl addition polymers which are sprayed onto bauxite ores to agglomerate the fines to prevent dusting. According to one embodiment of the invention, the bauxite ore is contacted with from about 0.0001-0.5 pounds of polymer per ton of ore. It should be noted that the upper limit of this range represents only an economical application level and that amounts above this will work but will be excessively costly. The dosage of the polymer will also vary depending on the severity of the dusting problems encountered. Tests of the invention demonstrate that treated ore does not become tacky and is easily handled even though the level of residual water in the ore would be expected to cause the ore to be tacky. Without intending to limit the invention, it is believed that the polymers bind a sufficient quantity of the water such that the water cannot be absorbed by the ore.
The polymers of the present invention are water-soluble, vinyl addition polymers. These polymers are well known to the art and have been described in numerous publications and patents. The water-soluble vinyl addition polymers of the present invention are anionic and, in some instances, the ionic charges are sufficiently slight so that the polymers may be considered noniomic. For example, polymers such as polyvinyl alcohol are noniomic, and polymers such as polyacrylic acid or acrylamidomethylpropane sulfonic acid containing polymers are anionic. All of these polymers may be used in the practice of the invention. The polymers preferred in the practice of the invention are acrylamide polymers which are commonly used in many industrial applications. Preferred acrylamide polymers include polyacrylamide and its water-soluble copolymeric derivatives such as, for instance, acrylamide-acrylic acid, and acrylamide-acrylic acid salt copolymers which contain from about 50-95 mole precent of acyrlamide. It is preferred in the practice of this invention to use acrylamide copolymers which are water-soluble and which contain at least 50 mole percent of acrylamide.
The molecular weight of the polymers described above may vary over a wide range, e.g.: 1,000,000-15,000,000. The invention, however, finds its greatest usefulness in preparing aqueous solutions or dispersions of these polymers and, in particular, acrylamide polymers whose molecular weight are less than about 15,000,000. Polymers having higher molecular weights are more difficulty dissolved in water and tend to form extremely viscous solutions at relatively low concentrations. However, these polymers are still useful in the practice of the invention. The polymers of the invention may be produced by any known methods of conducting polymerization reactions. Thus, solution suspension or emulsion polymerization techniques may be used. The polymers of the invention are most conveniently employed in the practice of the invention in the form of concentrated water and oil emulsions. Water and oil emulsions of water-soluble vinyl polymers are well known and are described in Vanderhoff U.S. Pat. No. 3,284,393 and Anderson-Frisque U.S. Pat. No. Re. 28,474, the disclosures of these patents are incorporated herein by reference.
In the Anderson-Frisque patent, it is disclosed that when the water and oil emulsions which contain the polymers are added to waters which contain water-soluble surfactants rapid dissolution of the polymers is achieved. This rapid dissolution technique is well suited for preparing treating solutions which contain the high molecular weight polymers of the invention.
According to one embodiment of the invention, the water-soluble vinyl addition polymers are prepared as oil and water emulsions having polymer concentrations within the range of about 20-40 percent by weight. More preferably, the polymer concentration is 25-35 percent by weight. The aqueous solutions of the invention are prepared from the oil and water emulsions described above. The aqueous solution include from about 0.0005 to about 0.5 percent by weight oil and water emulsion. More preferably, the aqueous solutions include 0.01 to 0.2 percent by weight oil and water emulsion. According to one embodiment of the invention, an emulsion is not used and dry polymer is added directly to water.
Water-soluble non-ionic monomers useful in the practice of the invention include acrylamide, N-substituted derivatives of acrylamide, hydroxyalky acrylates, hydroxyalky methacrylates, and N-vinyl formamide. Anionic monomers useful in the practice of the invention include the water-soluble ammonium and alkali metal salts of acrylic acid, methacrylic acid, ethacrylic acid, and 2-acrylamido-2-methyl propane sulfonic acid. In a preferred embodiment of this invention the nonionic monomers are acrylamide, N-N-dimethylacrylamide and 2-hydroxyethyl methacrylate, but the most preferred one is acrylamide. The preferred anionic monomers are the sodium salt of acrylic acid, methacrylic acid and 2-acrylamido-2-methyl propane sulfonic acid, and the most preferred one is the sodium salt of acrylic acid.
The following examples are presented to describe preferred embodiments and utilities of the invention and are not meant to limit the present invention unless otherwise stated in the claims appended hereto.
EXAMPLE 1
A. Treatment of Ore
Examples 2-5 were performed according to the following procedures. One thousand grams of ore having a residual water level of about 16% was placed in a rotating disc agglomerator. Water or an aqueous solution including 0.1% by weight of an oil and water emulsion of the vinyl addition polymers of the invention was sprayed onto the tumbling ore. In a plant operation, the treatment would, most likely, be sprayed onto the ore at belt transfer points or into a rotating drum. In the following examples, when the ore became tacky, it was evidenced by the ore sticking to and buildup on the rotating disc. This is similar to the problem of sticking to transfer belts in plant operations. After treatment, the ore was removed from the disc and either stored in a closed container for future dust testing or immediately placed in the dust box and evaluated. The tackiness of the treated ore was subjectively determined according to the criteria listed in Table 1 below.
TABLE 1______________________________________Measurement of Tackiness EstimatedScale Description Plant Operation______________________________________5 extreme sticking to disc could not run in plant4 sticking to treatment disc could not run in plant3 less sticking to treatment disc could not run in plant2 less sticking to treatment disc can run in plant1 slight sticking to treatment disc can run in plant0 dry ore can run in plant______________________________________
B. Drop Box Test for Dust
Before each test, the drop box was cleaned to remove all dust. One thousand grams of bauxite ore having a moisture level of about 16% was placed in a top compartment of the dust box. Below the top compartment are trap doors, which when opened, cause the ore to fall into a bottom compartment. A preweighed clean slide tray was positioned in a lower opening of the drop box so that it could be readily inserted. To conduct a trial, the trap doors of the top compartment of the drop box were opened causing the ore sample to fall to the bottom of the box, thereby causing dust to form throughout the chamber. After five seconds, the slide tray is inserted. The tray remains in place for five minutes to allow the dust to settle onto it. The slide tray is removed and weighed. The percent residual dust is calculated using the formula below. ##EQU1##
EXAMPLE 2
The polymers or copolymers evaluated in Examples 2-4 are listed below in Table 2.
TABLE 2__________________________________________________________________________ Wt. % Molecular Polymer Composition Actives Weight__________________________________________________________________________LatexPolymerA Acrylamide/Na acrylate, 93.8/6.2 28-29 5-10,000,000B Acrylamide 100% 26.5 5-10,000,000C Na acrylate, 100% 28-29 5-10,000,000D Acrylamide/Na acrylamido- 28-29 5-10,000,000 methylpropane sulfonic acid 89/11E Acrylamide/NH.sub.4 acrylate 65/35 39 5-10,000,000F Acrylamide/Na acrylate 69/31 28-29 5-10,000,000G Crosslinked polyacrylamide 28 >>10,000,000H Acrylamide/Na acrylate 69/31 31 1-5,000,000I Acrylamide/Na acrylate 69/31 34-34 10-15,000,000Dry PolymerJ Acrylamide/Na Acrylate 60/31 100 5-10,000,000__________________________________________________________________________ *Ratios are mole percent
In Example 2, the treated ore was stored twenty-four hours prior to the dust test. The residual moisture (moisture prior to treatment) of the ore was 15.9%. An additional 2.5% water was added through the treatment of the ore. As shown in table 3, the ore treated with only water was unacceptably tacky, while the ore treated with the polymer-water solution remained relatively non-tacky. Moreover, the ore treated with polymer-water solutions showed a 67-80% reduction in dusting over untreated samples and a 5-18% reduction in dusting over water alone.
TABLE 3______________________________________ *Dose Added H.sub.2 O Residual TackinessTreatment (lb/ton) (%) Dust (%) Measurement______________________________________Blank -- -- 100 0Water -- 2.5 45 3Blank -- -- 100 0Water -- 2.5 38 3A .05 2.5 27 1B .05 2.5 23 1C .05 2.5 20 1D .05 2.5 28 1E .038 2.5 33 1F 0.005 2.5 28 1F 0.05 2.5 19 1______________________________________ *Dose = lb/ton of oil and water emulsion including polymer
EXAMPLE 3
In Example 3, the treated ore was stored twenty-four hours prior to the dust test. The residual moisture (moisture prior to treatment) of the ore was 16.5%. An additional 2.5-5.0% water was added through the treatment of the ore. As shown in table 4, the ore treated only with water was unacceptably tacky, while the ore treated with the polymer-water solution remained non-tacky. Moreover, the ore treated with polymer-water solutions showed a 67-100% reduction in dusting over untreated samples and a 30-44% reduction in dusting over water alone. In fact, at the dose of 0.05 lb/ton of emulsion including polymer F, dusting was completely eliminated.
TABLE 4______________________________________ Dose Added H.sub.2 O Residual TackinessTreatment (lb/ton) (%) Dust (%) Measurement______________________________________Blank -- -- 100 0Water -- 2.5 63 4Water -- 5.0 44 5F .05 2.5 33 1F .05 5.0 0 2G .05 2.5 56 1G .05 5.0 8 2______________________________________
EXAMPLE 4
In Example 4, the treated ore was tested immediately. The residual moisture (moisture prior to treatment) of the ore was 16.5%. An additional 2.5-3.75% water was added through the treatment of the ore. As shown in table 5, the ore treated only with water was again unacceptably tacky. The ore treated with the polymer-water solution remained non-tacky. The ore treated with polymer-water solutions showed a 97-100% reduction in dusting over untreated samples, and a 4-12% reduction in dusting over water alone. Several of the treatments of the invention prevented dusting entirely.
TABLE 5__________________________________________________________________________ Storage Time Dose Added H.sub.2 O of Treated Residual TackinessTreatment (lb/ton) (%) Ore (hrs) Dust (%) Measurement__________________________________________________________________________Blank -- -- -- 100 0Water -- 2.5 24 12 4Water -- 3.75 24 4 5H .05 3.75 24 3 2H .10 3.75 24 0 1I .05 3.75 24 2 2I .10 3.75 24 0 1F .05 3.75 24 0 1F .05 2.5 24 1 1Water -- 2.5 0 2 4Water -- 3.75 0 1 5F .05 2.5 0 0 1__________________________________________________________________________F .05 3.75 0 0 1
EXAMPLE 5
Example 5 demonstrates the usefulness of dry polymer added directly to water, without using latex in an oil and water emulsion. In Example 5, the treated ore was tested immediately. The residual moisture (moisture prior to treatment) of the ore was 16.5%. An additional 2.5% water was added through the treatment of the ore. As shown in table 6, the ore treated only with water was unacceptably tacky. The ore treated with the polymer-water solution remained non-tacky. The ore treated with polymer-water solutions showed a 93% reduction in dusting over untreated samples, and was comparable to water alone.
TABLE 6______________________________________ Added *Dose H.sub.2 O Residual TackinessTreatment (lb/ton) (%) Dust (%) Measurement______________________________________Blank -- -- 100 0Water -- 2.5 0 3J 0.014 2.5 9 1______________________________________ *Active polymer
|
The invention provides a method for the suppression of bauxite dust emissions from dry, finely divided bauxite ore. The method includes the step of contacting bauxite ore with an aqueous solution of a water-soluble vinyl addition polymer. The polymer being selected from the group consisting of non-ionic and anionic water-soluble vinyl addition polymers.
| 2
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a neutral control device of an automatic transmission, more particularly, a device for preventing the slipping down of a vehicle stopped on an upward slope.
2. Description of the Prior Art
Generally, in the case where an automatic transmission is left as it is in a running range when the vehicle is stopped, engine vibration is transmitted to a vehicle through a motive power transmitting channel or engine load acts continually, with the result of wasteful fuel consumption.
In the light of the above problem, Japanese Patent Application Laid Open Gazette No. 59-34051, for example, discloses a device wherein when the vehicle is stopped, the transmission is controlled to be placed in "neutral" while a brake pedal is stepped on so as to prevent engine vibration from being transmitted to the vehicle, and also to save on fuel consumption because of the no-load state.
According to the above device, a transmission is controlled to be placed in "neutral" only while a brake pedal is stepped on and therefore movement of a vehicle will hardly take place so long as the brake is working, but when a driver releases the brake at starting, especially on a sloped road, the transmission is shifted from the "neutral range" to the "running range" by this releasing operation and formation of the starting gear position begins. However, until such gear position is formed, a vehicle will gradually go down the upward slope by its own weight.
BRIEF DESCRIPTION OF TUE INVENTION
In view of the above problem, the present invention has for its object to have a vehicle start smoothly, free from slippage in a backward direction, even upon starting on an upward slope road
In order to attain the above object, the present invention is designed so that even if a driver releases a brake pedal, action of the brake is maintained compulsorily until a gear position is achieved to a certain extent. More particularly, the device according to the present invention comprises a speed shifting control means to control a transmission to shift to "neutral" while the brake pedal is stepped on when the vehicle is stopped, an r.p.m. detecting means to detect r.p.m. on the input side of the transmissio, a pedal operation detecting means to detect operation of the brake pedal and a brake control means which maintains ON action of brake actuator until the change of r.p.m. on the input side of the transmission (caused by the brake pedal releasing operation and consequent shifting of the transmission to the starting gear position) drops below a set value corresponding approximately to the r.p.m. existing when the friction elements forming the starting gear position are connected.
Under the above construction of the present invention, so long as a driver is stepping on the brake pedal in a stopped state the transmission is controlled to be placed in "neutral" compulsorily and therefore engine vibration is not transmitted to a vehicle and engine load does not act, with the result that fuel consumption is reduced.
When a driver releases the brake pedal at starting, the transmission is shifted to the "running range" and frictional elements composing the starting gear position begin to connect. When connecting of frictional elements progresses, r.p.m. on the input side of the transmission lowers and connecting of frictional elements approaches completion. Namely, when a vehicle is ready to start smoothly due to transmission of engine motive power, r.p.m. on the input side of the transmission becomes below the set value and at this point of time, the brake actuator goes OFF and the vehicle will start smoothly, free from slipping down, even on an upward slope road.
The above object and novel features of the present invention will be more apparent by reading the following detailed description, with reference to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The attached drawings show a preferred embodiment of the present invention, in which:
FIG. 1 is a skeleton drawing of an automatic transmission:
FIG. 2 shows an oil pressure circuit for working a forward clutch;
FIG. 3 shows a brake oil pressure circuit;
FIG. 4 is a flow chart of speed shifting control and brake control by a controller; and
FIG. 5 is an explanatory drawing of the invention's operation.
DETAILED DESCRIPTION OF THE INVENTION
A description is made below of a preferred embodiment of the present invention.
FIG. 1 shows an automatic transmission Z of four forward stages and one reverse stage. Reference numeral 1 designates an engine output shaft. Reference numeral 2 designates a torque converter equipped with a pump 2a connected to the engine output shaft 1, a stator 2b and turbine 2c. The stator 2b is provided fixably at a case 4 through the medium of a one-way clutch which prevents the stator 2b from rotating in the direction opposite to the turbine 2c. Reference numeral 5 designates a speed change gear connected to converter output shaft 2d which is connected to the turbine 2c of the torque converter 2.
The speed change gear 5 has within a Lavinyo type planetary gearing 7. This planetary gearing 7 comprises a sun gear 8 of small diameter, a sun gear 9 of large diameter, a short pinion gear 10 which meshes with the sun gear 8, a long pinion gear 11 which meshes with the sun gear 9 and the short pinion gear 10 and a ring gear 12 which meshes with the long pinion gear 11. The sun gear 8 of small diameter is connected to the output shaft 2d of the torque converter 2 through the medium of a forward clutch 15 provided rearwardly of the sun gear 8 and a first one-way clutch 16 which is connected vertically to the clutch 15 and which checks the reverse drive of the converter output shaft 2d. A coast clutch 17 is connected in parallel to the channel which connects vertically the forward clutch 15 and the one-way clutch 16. The sun gear 9 of large diameter is connected to the output shaft 2d of the torque coverter 2 through the medium of a 2-4 brake 18 provided rearwardly of the sun gear 9 and a reverse clutch 19 arranged rearwardly of the 2-4 brake 18. Connected to the long pinion gear in a row through the medium of its rear side carrier 20 are low & reverse brake 21 which fixes the long pinion gear 11, and a second one-way clutch 22 which allows the long pinion gear 11 to rotate in the same direction as the engine output shaft 1. A front side carrier 23 of the long pinion gear 11 is connected to the output shaft 2d of the torque converter 2 through the medium of a 3-4 clutch 24. The ring gear 12 is connected to an output gear 25 arranged in front of the ring gear 12. In FIG. 1, reference numeral 27 designates a lock up clutch which connects the engine output shaft 1 directly with the converter output shaft 2d. Reference numeral 28 designates an oil pump which is driven by the engine output shaft 1 through the medium of an intermediate shaft 29.
__________________________________________________________________________ FOR- LOW & No. 1 No. 2 REVERSE COAST WARD 3-4 REVERSE 2-4 ONE-WAY ONE-WAY CLUTCH CLUTCH CLUTCH CLUTCH BRAKE BRAKE CLUTCH CLUTCH__________________________________________________________________________ P R ◯ ◯ N(D) 1 SPEED SHIFT ◯ (◯) (◯)RANGE STAGE2 SPEED SHIFT ◯ ◯ (◯) STAGE3 SPEED SHIFT ◯ ◯ ◯ (◯) STAGE0 D ◯ ◯ ◯(2) 1 SPEED SHIFT ◯ (◯)RANGE STAGE2 SPEED SHIFT ◯ ◯ ◯ (◯) STAGE3 SPEED SHIFT ◯ ◯ ◯ (◯) STAGE(1) 1 SPEED SHIFT ◯ ◯ ◯ (◯)RANGE STAGE2 SPEED SHIFT ◯ ◯ ◯ (◯) STAGE__________________________________________________________________________ Remark: (◯) shows that a clutch is working but is not contributing to power transmission.
As can be seen from the above table, at the first gear position if in the (D) range (running range) and at the N (neutral) position, only the action of the forward clutch 15 is different and therefore in this embodiment, when a vehicle stops in the (D) range, the forward clutch 15 is released to shift to the N position.
An explanation is made below of an oil pressure circuit which supplies and discharges working oil in relation to frictional elements of the forward clutch 15.
Provided in an oil pressure circuit 60 is a pressure regulator valve 66 which regulates pressure of working oil discharged from the oil pump 28 shown in FIG. 1 to a main line 65 to the specified line pressure. Provided close to the pressure regulator valve 66 is a throttle valve 67 which generates throttle pressure according to the throttle valve opening of the engine. A throttle modulator 68 which modulates the throttle pressure and a backup valve 69.
Also provided in the oil pressure circuit 60 is a manual valve 70 which sends out selectively line pressure generated at the pressure regulator valve 66 to each oil pressure line according to the selected range.
A first output line 71 connected to the first output port in the manual valve 70 is a line which communicates with the main line 65 in each forward range of (D), (2) and (1).
This line 71 is led to the forward clutch 15 through the medium of a one-way orifice 72. In the (D), (2) and (1) ranges, the forward clutch 15 is kept clutched.
Provided at the first output line 71 is an N-D accumulator which buffers clutching of the forward clutch 15 and a control valve 75 which puts in or releases the forward clutch 15.
The control valve 75 has a spool 75a and a drain port 75b. While a spring 75c is provided in compression leftward in the figure, a pilot room 75d is formed rightward in the figure. The line 71 on the upstream side of the control valve 75 is connected to the pilot room 75d via a passage 76. The control valve 75 also has a solenoid 77 carrying a valve body 77a which opens and closes the pilot room 75d. The solenoid 77, in an OFF state, generates pilot pressure by biasing the valve body 77a in the left direction in the figure by means of the spring 77b to close the pilot room 75d. By biasing the spool 75a of the control valve 75 in the left direction in the figure by that pilot pressure, the drain port 75b is closed and clutching pressure of the line 71 is supplied to the forward clutch 15 for clutching. On the other hand, at the time of an ON state, the valve body 77a is moved in the right direction in the figure against biasing force of the spring 77b to open the 25 pilot room 75d, whereby the spool 75a of the control valve 75 is moved in the right direction in the figure to close the line 71 on the upstream side but to make the line 71 on the downstream side communicate with the drain port 75b so as to release clutching pressure and release clutching action of the forward clutch 15.
An explanation is made below of a brake oil pressure maintaining circuit for wheels, with reference to FIG. 3 (a circuit which produces ordinary brake oil pressure is omitted). In FIG. 3, reference numeral 80 designates a front wheel. Reference numeral 81 designates a rear wheel. Reference numeral 82 designates a brake pedal. Reference numeral 83 designates a master cylinder which generates brake oil pressure. Oil pressure generated at the master cylinder 83 acts independently on left and right front wheels 80 via two pipings 84 on the front wheel side and also acts on each wheel cylinder 81a of left and right rear wheels 81 via a piping 85 on the rear wheel side. The two pipings 84 on the front wheel side and the piping 85 on the rear wheel side are equipped with magnet valves 87. Each magnet valve 87 has two positions, namely, a holding position 87a which intercepts the corresponding piping 84 or piping 85 and a pressure reducing position 87b which makes the pipings 84, 85 on the downstream side (wheel side) communicate with a reservoir 88 and closes the pipings 84, 85 on the upstream side. When the magnet valve 87 is at the holding position 87a, it holds brake oil pressure which acts on wheel cylinders 80a, 81a but when it is at the pressure reducing position 87b, it returns brake oil which acts on wheel cylinders 80a, 81a to the reservoir 88 to reduce brake oil pressure.
In FIG. 3, reference numeral 90 designates a controller having therein a CPU, etc. By this controller 90, the above-mentioned three magnet valves 87 and the control valve 75 are controlled. Signals are inputted to the controller 90 from each of a brake switch 91 (acting as a pedal detecting means which detects operation of the brake pedal 82 and is switched ON when a stepping on operation is detected and switched OFF at the time of a releasing operation), an idle switch 92 which detects releasing operation of an accelerator pedal (not shown in the drawing). a vehicle velocity sensor 93 which detects vehicle velocity, a turbine r.p.m. sensor 94 (as an r.p.m. detecting means which detects turbine r.p.m. of the torque converter 2 as r.p.m. on the input side of the speed change gear 5 of the automatic transmission Z) and an inhibitor switch 95 which detects the range position of the automatic transmission Z.
An explanation is made below of the gear change control and the brake control by the controller 90 at the time that the vehicle is stopped and at the time of starting, on the basis of the control flow chart of FIG. 4.
Upon starting, at step S 1 it is judged whether or not the automatic transmission is in the (D) range on the basis of the output of the inhibitor switch 95. At step S 2 it is judged whether or not the vehicle velocity is zero, at step S 3 it is judged whether or not the idle switch 92 is ON (at the time of releasing the accelerator pedal) and at step S 4 it is judged whether or not the brake switch 9 is ON (at the time of stepping on the brake pedal 82). In the case where all of the above judgements are YES, namely, in the case where a vehicle stops with the brake working in the (D) range, at step S 5 while the control valve 7 is ON to control the forward clutch 15 to the release side and control the gear position to "neutral", the magnet valve 87 is controlled to an ON state, i.e., to the intercepting position 87a and to hold brake oil pressure acting on each wheel cylinder 80a, 81a of the wheels 80, 81. Then, at step S 6 it is confirmed that brake oil is in a held state by setting flag F=1.
On the other hand, in a case of the forward running range other the (D) range at steps S 1 -S 3 , in the case of running at vehicle velocity ≠0, or in the case of the idle switch 92 being OFF (at the time of stepping on the accelerator pedal), at step S 12 flag F is reset to F=0 and control proceeds to step S 7 . When the brake pedal is released at step S 4 control proceeds immediately to step S 7 . At step S 7 , as it is judged to be "running" or "at starting". the control valve 75 is controlled to OFF to control the forward clutch 15 to the clutching side and to make it possible to create the first gear-fourth gear (OD) stages. In the case where flag F≠1 at step S 8 , at step S 9 the magnet valve 87 is controlled to OFF, i.e., to the pressure reducing position 87b so as to avoid trouble during running and releases the brake which acts on the wheel cylinders 80a, 81a of the wheels 80, 81.
In the case where F=1 at step S 8 , it is the brake oil pressure holding state at a time when the vehicle is stopped and at step S 10 turbine r.p.m. is compared with a set value N 0 . This set value N 0 is a value close to the turbine r.p.m. at the point of time when the first gear position (gear position at starting) is nearly formed by clutching action of the forward clutch 15. In the case where turbine r.p.m.>N 0 , it is judged that formation of the first gear position is not yet finished and at step S 11 ON control of the magnet valve 87 is maintained and brake oil pressure acting on the wheels 80, 81 is maintained as it is.
At step S 10 , if turbine r.p.m.>N 0 and the first gear position is almost formed, at step S 9 the magnet valve 87 is controlled to OFF and brake oil pressure acting on the wheels 80, 81 is released and then control proceeds to RETURN.
In the control flow chart of FIG. 4, by steps S 1 -S 5 compose a speed shifting control means 97 which controls the automatic transmission Z to "neutral" while the brake pedal 82 is stepped on and the vehicle is stopped. Steps S 4 , S 6 -S 11 , compose, a brake controlling means 98 whereby change of turbine r.p m. of the transmission due to receiving outputs of the brake switch 91 and the turbine r.p.m. sensor 94 and due to the first stage (as the starting gear position) being formed at the transmission Z by releasing operation of the brake pedal 82, maintains the magnet valve 87 in an ON condition until the turbine r.p.m. becomes smaller than the set value N 0 corresponding approximately to the time for complete clutching of the forward clutch 15 which composes the first gear. Thereby, of action of wheel cylinders 80a, 81a of each wheel, as brake actuators, is maintained to avoid slippage of the vehicle.
The working of the above embodiment is explained below on the basis of FIG. 5.
When a driver releases the accelerator pedal and steps on the brake pedal so as to stop a vehicle, the idle switch 92 is turned ON and the brake switch 91 is also turned ON.
When the vehicle velocity decreases and reaches zero by the action of the brake, the control valve 75 is controlled to ON, whereby the forward clutch 15 is released, the gear position becomes "neutral", the magnet valve 87 is ON controlled and brake pressure of each wheel is maintained In this case, turbine r.p.m. of the transmission decreases with the reduction of vehicle velocity but when the gear position becomes "neutral", turbine r.p.m. rises again and settles down an r.p.m. corresponding to the idle r.p.m. of the engine.
Then, when the driver operates the shift lever of the automatic transmission to shift from the "neutral range" to the "drive range" and releases the brake pedal 82 (whereupon the brake switch 91 is turned OFF), the control valve 75 is controlled to OFF and accordingly the forward clutch 15 begins a clutching operation whereby the first gear stage begins to be formed. Then, with the start of formation of the first gear, turbine r.p.m. begins to decrease and becomes smaller than the set value N 0 . When the first gear stage is almost formed, the magnet valve 87 is controlled to OFF and the action of the brake is released. Therefore, even at the time of stopping on an upwardly sloped road, the vehicle is prevented from slipping down and can start smoothly. Moreover, as the period of time during which action of the brake is maintained is the period of time until the first gear is almost formed. Namely, the minimum period of time before starting of a vehicle, more action of the brake than is necessary does not take place and the vehicle can be started smoothly.
In an above embodiment, the explanation is made regarding the case of the vehicle being stopped in the "D range" but it is a matter of course that the present invention is applicable to the other cases. For example, in the case where a vehicle stops at (1) range in the table, both of the forward clutch 15 and the coast clutch 17 are released to shift to "neutral". Similarly, in the case where a vehicle stops at (R) range, the reverse clutch 19 is released to shift "neutral".
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A device provides transmission control whereby when a vehicle starts from standing state, even if a driver releases a brake pedal, action of the brake is maintained compulsorily until the starting gear position is formed by connection of frictional elements in the automatic transmission. Therefore, this device prevents effectively a vehicle from slipping down, upon starting on an upwardly sloped road, without more action of the brake than is necessary and with good startability.
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INTRODUCTION
It is desirable for many reasons to replicate stored data between a number of data stores. This provides redundancy in the event of disaster or failure of a primary data store. For simple data types, this can be as simple as sending a single message from a primary data center to a secondary data center. However, for more complex data types, interdependencies between data entries and a lack of guaranteed message ordering render simple replication strategies ineffective. Accordingly, methods of replicating versioned and hierarchical data structures are provided herein.
SUMMARY
Embodiments of the present invention relate to replicating versioned and hierarchical data structures in a replicated data storage system. Operations on data structures, including atomic structures representing distributed transactions and hierarchical data structures, exhibit dependencies between the messages making up the operations. For example, a child object might not be creatable before the parent object has been created. These dependencies can be enforced by using versioning for the various levels of the hierarchy such that that the different levels of the hierarchy can be independently replicated, but lower levels of the hierarchy are not visible to the client until the corresponding versions of the higher level have been committed. At other times it is important to have a consistent view committed across part of the hierarchy committing a distributed transaction. This consistent view can be provided by suspending the committing of parts of a distributed transaction until the distributed transaction has been fully replicated and ready to be committed, as well as mechanisms to coordinate the commit.
This Summary is generally provided to introduce the reader to one or more select concepts described below in the Detailed Description in a simplified form. This Summary is not intended to identify the invention or even key features, which is the purview of claims below, but is provided to be patent-related regulation requirements.
BRIEF DESCRIPTION OF THE DRAWING
Illustrative embodiments of the present invention are described in detail below with reference to the attached drawing figures, and wherein:
FIG. 1 depicts an exemplary computing device suitable for implementing embodiments of the present invention;
FIG. 2A depicts a simple environment suitable for implementing embodiments of the present invention;
FIG. 2B depicts a more complex environment suitable for implementing embodiments of the present invention;
FIG. 3 depicts a flowchart diagram for a method of replicating versioned and hierarchical data structures in accordance with an embodiment of the present invention;
FIG. 4 depicts several illustrative examples of hierarchical data structures suitable for replication by embodiments of the present invention;
FIG. 5 depicts a flowchart diagram for a method for processing a distributed transaction in a replicated storage environment in accordance with an embodiment of the present invention; and
FIG. 6 depicts a flowchart diagram for a method of using versioned data structures to process distributed transactions in a replicated storage environment in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION
The subject matter of the present invention is described with specificity to meet statutory requirements. However, the description itself is not intended to define the scope of the claims. Rather, the inventors have contemplated that the claimed subject matter might also be embodied in other ways, to include different steps or combinations of steps similar to the ones described in this document, in conjunction with other present or future technologies. Moreover, although the term “step” may be used herein to connote different elements of methods employed, the term should not be interpreted as implying any particular order among or between various steps herein disclosed unless and except when the order of individual steps is explicitly described. Further, the present invention is described in detail below with reference to the attached drawing figures, which are incorporated in their entirety by reference herein.
Embodiments of the present invention relate to replicating versioned and hierarchical data structures and distributed transactions. In one aspect, the present invention provides one or more computer storage media having computer-executable instructions embodied thereon that, when executed, cause a computing device to perform a method of replicating hierarchical data structures. The method comprises receiving, at a secondary data store, a message from a first primary data store and determining that the first message pertains to a data object having a parent data object, which has a parent object identifier and a parent version identifier. The method further comprises determining that the parent data object with the parent object identifier and the parent version identifier is not stored at the secondary storage location and suspending the further processing of the transaction. The method also comprises receiving, at the secondary data store, a second message from a second primary data store, processing the second transaction to creating the parent data object with the parent object identifier and the parent version identifier and, after creating said parent data object, resuming the processing of the first transaction.
In another aspect, the present invention provides a computer-implemented method in a distributed computing environment utilizing a processor and memory for processing a distributed transaction in a replicated storage environment. The method comprises receiving, at a secondary data store, a plurality of messages from one or more primary data stores, each message containing a distributed transaction identifier and determining that the distributed transaction identifier in each the messages corresponds to the distributed transaction. The method further comprises receiving, at the secondary data store, a commit-distributed-transaction message, which contains the distributed transaction identifier and an indicator for the plurality of the messages. This indicator can be a count of messages, a list of transaction identifiers, or other way of knowing when all of the component transactions of the distributed transaction have been received. The method also comprises postponing the processing of the messages and the commit-distributed-transaction message and, after the commit-distributed-transaction message has been received and the indicator indicates that each of the plurality of messages corresponding to the distributed transaction has been received, using the plurality of messages to cause the distributed transaction to be atomically committed.
A third aspect of the present invention provides one or more computer storage media having computer-executable instructions embodied thereon that, when executed, cause a computing device to perform a method for processing a distributed transaction. The method comprises receiving a first object replication message including an object with an object name and object data and identifiers for one or more parent objects, each parent object identifier including a parent object name and a parent object version. The method further comprises determining a full object identifier including at least the object name, the parent object names, and the parent object versions. The method also comprises committing a transaction creating object corresponding to the full object identifier and the object data independently of whether the one or more parent objects exist and determining a live version of the object. In some embodiments, non-live versions of the object are then garbage collected.
Having briefly described an overview of embodiments of the present invention, an exemplary operating environment suitable for implementing embodiments hereof is described below.
Referring to the drawings in general, and initially to FIG. 1 in particular, an exemplary operating environment suitable for implementing embodiments of the present invention is shown and designated generally as computing device 100 . Computing device 100 is but one example of a suitable computing environment and is not intended to suggest any limitation as to the scope of use or functionality of the invention. Neither should the computing environment 100 be interpreted as having any dependency or requirement relating to any one or combination of modules/components illustrated.
Embodiments may be described in the general context of computer code or machine-useable instructions, including computer-executable instructions such as program modules, being executed by a computer or other machine, such as a personal data assistant or other handheld device. Generally, program modules including routines, programs, objects, modules, data structures, and the like, refer to code that performs particular tasks or implements particular abstract data types. Embodiments may be practiced in a variety of system configurations, including hand-held devices, consumer electronics, general-purpose computers, specialty computing devices, etc. Embodiments may also be practiced in distributed computing environments where tasks are performed by remote-processing devices that are linked through a communications network.
With continued reference to FIG. 1 , computing device 100 includes a bus 110 that directly or indirectly couples the following devices: memory 112 , one or more processors 114 , one or more presentation modules 116 , input/output (I/O) ports 118 , I/O modules 120 , and an illustrative power supply 122 . Bus 110 represents what may be one or more busses (such as an address bus, data bus, or combination thereof). Although the various blocks of FIG. 1 are shown with lines for the sake of clarity, in reality, delineating various modules is not so clear, and metaphorically, the lines would more accurately be grey and fuzzy. For example, one may consider a presentation module such as a display device to be an I/O module. Also, processors have memory. The inventors hereof recognize that such is the nature of the art, and reiterate that the diagram of FIG. 1 is merely illustrative of an exemplary computing device that can be used in connection with one or more embodiments. Distinction is not made between such categories as “workstation,” “server,” “laptop,” “hand-held device,” etc., as all are contemplated within the scope of FIG. 1 and reference to “computer” or “computing device.”
Computing device 100 typically includes a variety of computer-readable media. By way of example, and not limitation, computer-readable media may comprise the following exemplary non-transitory media: Random Access Memory (RAM); Read Only Memory (ROM); Electronically Erasable Programmable Read Only Memory (EEPROM); flash memory or other memory technologies; CDROM, digital versatile disks (DVD) or other optical or holographic media; magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to encode desired information and be accessed by computing device 100 .
Memory 112 includes computer-storage media in the form of volatile and/or nonvolatile memory. The memory may be removable, non-removable, or a combination thereof. Exemplary hardware devices include solid-state memory, hard drives, optical-disc drives, etc. Computing device 100 includes one or more processors that read data from various entities such as memory 112 or I/O modules 120 . Presentation module(s) 116 present data indications to a user or other device. Exemplary presentation modules include a display device, speaker, printing module, vibrating module, and the like. I/O ports 118 allow computing device 100 to be logically coupled to other devices including I/O modules 120 , some of which may be built in. Illustrative modules include a microphone, joystick, game pad, satellite dish, scanner, printer, wireless device, and the like.
Turning now to FIG. 2A , a simple environment suitable for practicing a method of replicating versioned and hierarchical data structures is presented in accordance with an embodiment of the present invention. A primary data store 202 maintains an authoritative version of the data to be replicated. Secondary data store 204 maintains a replicated copy of the data stored at primary data store 202 . Each data store component shown in FIG. 2 may be any type of computing device, such as computing device 100 described with reference to FIG. 1 , for example. Primary data store 202 and secondary data store 204 communicate in the illustrated embodiments via Internet 206 . In other embodiments, primary data store 202 and secondary data store 204 communicate via a local area network, or are co-located on the same computer and communicate via inter-process communication.
Turning now to FIG. 2B , a more complex environment suitable for practicing a method of replicating versioned and hierarchical data structures is presented. Four data stores, a first data store 208 , a second data store 210 , a third data store 212 , and a fourth data store 214 are depicted. In the environment as shown, no data store is explicitly a primary data store or a secondary data store, per se, but rather each data store acts as a primary data store or secondary data store with respect to certain data. As an illustrative example, with regards to certain data, the first data store 208 acts as a primary data store, while the second data store 210 acts as a secondary data store and the third and fourth data stores 212 and 214 do not store the data at all. In an alternative example, the fourth data store 214 acts as a primary data store, while both the second and third data stores 210 and 212 act as secondary data stores. Note that a data store may act as a primary data store for certain data, a secondary data store for other data, and not store still other data at all. As in FIG. 2A , the data stores are depicted as communicating via Internet 206 , though other methods of communication are envisioned.
It should be noted that, although the environment in which many embodiments will be practiced will more closely resemble FIG. 2B than FIG. 2A , those embodiments will be discussed herein in the context of FIG. 2A for the purposes of simplicity. It will be apparent to one skilled in the art how such discussion can be applied in the context of more complex environments such as FIG. 2B .
Turning now to FIG. 3 , a flowchart diagram for a method 300 of replicating versioned and hierarchical data structures in accordance with an embodiment of the present invention is presented. At a step 302 a message from a primary data store is received at a secondary data store, the message pertaining to a data object. If the data object is part of a hierarchy of data objects, it may have a parent data object. Any hierarchical relationship is determined at a step 304 . For a further discussion of hierarchical data structures, see FIG. 4 and the accompanying discussion. If the object is not a part of a hierarchy of data objects, or if it is a part of such a hierarchy but has no parent data object, processing proceeds to a step 306 , wherein the message is committed. If the object does have a parent data object, it is checked at a step 308 whether this parent data object is present at the secondary data store. This check can fail in two ways: first, the parent object may not be present; second, the parent data object may be present, but may not meet a required version.
To see how the latter situation can arise, consider an illustrative example where a parent data object with a given identifier contains one or more child data objects. In this case, a message deleting the parent data object may also require the deletion of all child data objects it contains. In this example, three messages are sent: a first message that deletes the parent data object, a second message that creates a new parent data object with the same identifier, and a third message that adds a child data object to the newly created parent data object. Since the ordering of child messages is not guaranteed with respect to the parent messages, the third message could be received before the first data message. In the absence of versioning, the child data object would be added to the original parent object before it is deleted, and then deleted along with the parent data object. Thus, the net result of the three messages is, in this example, an empty new parent object.
By contrast, when versioning is used, if the third message is received first, it may indicate that it requires the later version of the parent data object, as created by the second message. Processing can thus be suspended (as described below) until the first two messages have been received and processed, resulting in a new parent object containing the new child object, as intended. Thus, if the parent object is not present (e.g. if the third message is received between the first and second messages in the preceding example), or if the parent object is present but not of the required version at step 308 , processing of the received message is suspended at a step 310 . Following step 310 , the methodology returns to the step 302 to await further messages, which may allow the suspended message to be further processed. Note that the messages required to allow processing of the suspended message may come from the same primary data store as the suspended message, or they may come from a different primary data store.
If the required version of the parent object is present, the exemplary methodology proceeds to step 306 , where the transaction contained in the message is committed. Committing a transaction may create an object that is a parent object for a suspended message, update a parent object to a required version, or otherwise satisfy a prerequisite of a suspended data message. Accordingly, at a step 312 , it is determined if any currently suspended messages can now be processed. If not, the algorithm returns to step 302 to await further messages. If prerequisites for a suspended message have been met, than that message is recalled at step 314 , which allows processing to return to the step 306 and the transaction contained in the newly recalled message is committed in turn. As previously discussed, this may create an object that is a parent object for another suspended message, update a parent object to a required version, or otherwise satisfy the prerequisites of another suspended data message. Accordingly, the step 312 again checks for additional messages that can now be processed. In this fashion, a receiving single message can enable a large number of transactions to be committed.
It should also be noted that, in some embodiments, certain data objects may require multiple messages to be created. In one exemplary embodiment, certain very large data objects may require multiple messages to transmit from the primary data store to the secondary data store. For example, blob objects can be too large to transmit in a single message. In another exemplary embodiment, creating a data object may be a multi-step process. In this case, once all of the prerequisites of a data object are satisfied, all of the transactions pertaining to that data object are committed atomically. For more detail regarding atomic commits, see FIG. 5 .
Turning now to FIGS. 4A-4D , several illustrative examples of hierarchical data structures are depicted suitable for replication by embodiments of the present invention. FIG. 4A presents a simple hierarchical data relationship. A parent data object 402 , “P,” has a single child data object 404 , “C”. In one example, the parent data object is a blob container and the child data object is a blob object. As another example, the parent data object could be a table, and the child data object could be an entity associated with the table. For the sake of generality, the terms “parent” and “child” are used, but some embodiments of hierarchical data structures represent a data types, not conventionally thought of in parent/child terms. For example, the parent data object may be a message queue, and the child data object may be a message object associated with that queue. In an exemplary embodiment, a “blob” represents the basic storage object to be replicated, such as the file in a file system, and a “blob container” represents a logical grouping of blobs, much like the directory in a file system. For structured storage, “tables” can be used that store “rows.” Additional data structures include “queues” that are used for delivering “messages,” which can be put into and retrieved from the queues. FIG. 4B presents a multi-level hierarchy. Here, a parent data object 406 , “P,” has a child data object 408 , “C 1 .” However, data object 408 is itself the parent data object to a child data object 410 , “C 2 ,” which is in turn the parent of a child data object 412 , “C 3 .” Thus, for the illustrated data hierarchy in this embodiment, the depicted data objects must be created strictly in the order P, followed by C 1 then C 2 and then C 3 . A data object which has no parent data object is sometimes called a “root object.” In some embodiments, a data structure can have multiple root objects, resulting in a disconnected data structure. A data object which is the parent of given data object, or the parent of the parent of the given object, etc., is said to be an “ancestor” of the given object, and the ancestors of an object are said to be “above” it in the data hierarchy. Thus, in the example depicted in FIG. 4B , the ancestors of data object 412 , “C 3 ” are the data objects 410 (“C 2 ”), 408 (“C 1 ”), and 406 (“P”). A data object is said to be “below” its ancestors in the data hierarchy. Thus, the data object 412 (“C 3 ”) is below the data objects 410 (“C 2 ”), 408 (“C 1 ”), and 406 (“P”).
By contrast, FIG. 4C depicts a different data hierarchy for P, C 1 , C 2 and C 3 . Here, parent data object 414 is the direct parent for data objects 416 , 418 and 420 . Thus, for this data structure, P must be created first, but once it has been created, C 1 , C 2 and C 3 can be created in any order. Hence, in one embodiment, a data structure depicted in FIG. 4B could be employed for storing files in a hierarchical directory namespace, where the hierarchy represents the directories created in the namespace, while a data structure such as FIG. 4C could be used to store a message set, where the order of the messages is not significant. Other permutations are also possible, as shown in FIG. 4D . There, parent data object 422 , “P,” has two child data objects, 424 (“C 1 ”) and 426 (“C 2 ”). Data object 424 , C 1 , is in turn the parent data object for two child data objects, 428 (“C 3 ”) and 430 (“C 4 ”). Note also that data object 428 (“C 3 ”) is neither an ancestor of, nor below, data object 426 (“C 4 ”). Such data objects are said to be “incomparable.” The permissible orders of object creation for the hierarchical data structures such as FIG. 4D are more complicated to determine than simpler data structures such as FIGS. 4A-4C , but can be determined by techniques such as a topological sort.
Turning now to FIG. 5 , a flowchart diagram depicting a method 500 for processing a distributed transaction in a replicated storage environment according to one embodiment of the present invention is presented. Initially, at a step 502 , a commit-distributed-transaction (CDT) message is received at a secondary data store from a primary data store. This CDT message will, in many embodiments, contain a distributed transaction identifier (DTI) and a transaction message count. The DTI serves to link together all of the messages making up the distributed transaction, and the transaction message count indicated the total number of messages making up the distributed message. In other embodiments, instead of a transaction message count, the individual transaction identifiers of each transaction making up the distributed transaction are included instead. At a step 504 , the DTI and information identifying the transaction messages, which can be a count or a set of transaction identifiers, are extracted from the CDT message. In one embodiment, this causes a distributed transaction log associated with the DTI to be created. Next at a step 506 , another message is received at the secondary data store. This message may be from the same primary data store as the CDT message, or it may be from another primary data store. In one embodiment, it may be received from another secondary data store. Similarly, the component messages making up the distributed transaction may all originate from the same primary data store, or they may originate from many primary data stores. Next, at a step 508 , the received message is examined to see if it contains a DTI and if that DTI matches the DTI received in the CDT message. Although, in this illustrative example, only a single distributed transaction is shown as being processed, in some embodiments of the invention, many distributed transactions could be underway simultaneously. Thus, a message containing a CDT may be processed as part of the appropriate distributed transaction.
If the message does not contain a DTI, or if the DTI does not match the DTI contained in the CDT message, the message is processed by other means (which may include being processed as part of the appropriate distributed transaction) at a step 510 . If the message does contain a matching DTI, a received message count associated with the distributed transaction is incremented at a step 512 . Though the embodiment shown uses a message count, a corresponding step of marking a transaction identifier as received may be substituted in those embodiments that send a set of transaction identifiers instead of a message count. At a step 514 , the received message count is compared to the transaction message count contained in the CDT message. If the received message count is less than the transaction message count (or if the CDT message has not yet been received; see below), the message is stored in a transaction message log at a step 516 . In one embodiment, the transaction message log is associated with the DTI. In another embodiment, a single transaction log is shared between all distributed transactions. In yet another embodiment, a single message log is shared between all messages that cannot be yet processed for any reason. In another embodiment, the transaction is stored in a global message log, waiting for the Distributed Transaction Engine (DTE) to cause its transaction to be committed. In still another embodiment, the transaction is stored in a local message log and its identifier is registered with a global distributed transaction table, which is polled to determine when the transaction can be committed.
Although the CDT message is received first in the described embodiment, this will not always be the case. In many embodiments, the CDT message will only be sent after all of the messages making up the distributed transaction have been sent, and will therefore be received last. Embodiments in which the CDT is received first, last, or among the component messages of the transaction all fall within the scope of the invention.
Once the received message count is determined to be equal to the transaction message count at step 514 , indicating that all of the messages making up the distributed transaction and the CDT message have been received, the distributed transaction can be committed. This process begins at a step 518 , wherein all of the messages pertaining to the distributed transaction are extracted from the transaction logs. In some embodiments, the messages may need to be ordered appropriately at this point. In other embodiments, the messages are maintained in the transaction log in the order in which their transactions are to be committed. In yet other embodiments, the order in which the transactions are committed is unimportant. Next, at a step 520 , the distributed transaction is committed atomically on the secondary data store. In some embodiments, this is accomplished using two-phase commit or some other local protocol that provides fast atomic committing within a data store. Some embodiments may relax the requirement for atomic commit of certain distributed transactions. This allows the atomic committing of a distributed transaction to occur completely within a primary data store, and then after all of the changes are replicated to the secondary data store, the distributed transaction to be atomically committed in the secondary data store. This allows the primary and secondary data stores to be decoupled and allows the distributed transaction to be asynchronously committed on the secondary.
When committing a distributed transaction atomically, any access of the data store must show either all of the component transactions committed or none of them committed. A data store may allow multiple entities to be updated within a single atomic transaction. As an illustrative example consider a shopping cart application, where the distributed transaction specifies that a first item (entity) is added to the cart, a second item is added to the cart, and a third entity which represents the total price of objects in the cart is updated at the same time. The distributed transaction represents atomically committing these 3 transactions. The CDT message then contains the count or transaction IDs for each of these entities along with the distributed transaction identifier. As each of the entities is processed, it is determined that they are part of distributed transaction and they are registered with the distributed transaction engine (DTE) together with their individual transaction identifier and the DTI. Once all three transactions have been registered with the DTE, the DTE is responsible for performing the atomic commit and any rollback of the distributed transaction if need be.
A move operation that changes the location of a data structure can similarly be performed atomically. Similarly, for a distributed transaction such as a copy operation, which creates a second, substantially identical data structure in a different location or with a different name, either all of the copied structure should be visible, or none of it should be. For example, if a large data object is being copied, requiring many messages, there should never be a state when only a portion of the object is visible at the data store.
Turning now to FIG. 6 , a flowchart diagram for a method of using versioned data structures to process distributed transactions in a replicated storage environment in accordance with an embodiment of the present invention, the method generally referred to by the reference numeral 600 . This method is suitable, for example, for execution by a secondary data store in the replicated storage environment. At a step 602 , a message containing a transaction having the effect of creating an object is received. As described above with reference to certain other embodiments, the object exists within a hierarchy of other objects. As an example, at the root of the hierarchy, there may be an account name. Under the account name, one or more container objects may exist, and each of these container objects may contain leaf objects or other container objects. Any or all of these objects within the hierarchy may be versioned. A portion of an exemplary hierarchy might contain three layers: (1) an account name and version for the account, (2) a container name and version for the container, and (3) a blob name. Each object in the hierarchy can be uniquely identified by a full object identifier constructed by concatenating the names and versions of all parent objects with the name (and, in some embodiments, the version) of the object. Thus the blob above could be uniquely identified by the identifier (accountName+accountVersion)+(ContainerName+containerVersion)+BlobName. This has the advantage of allowing each of the different levels of the hierarchy to be independently replicated and committed at a secondary data store, as described below.
At a step 604 , the full object identifier for the object to be created is determined. In some embodiments, this full object identifier is included in the message received at step 602 ; in other, it is constructed from information contained in that message. Because the full object identifier contains the identifiers of all of its parents in the hierarchy, this can be done without first checking to see if the correct versions of the parents have previously been created. Thus, at a step 606 , the transaction creating the object is committed. These steps may be repeated many times for different objects at different levels of the hierarchy. At a step 608 , when it is determined that a failover has occurred, the secondary data store must be prepared to present a consistent view of the hierarchy, which requires determining a live version of an object to be retrieved. This is shown as occurring at a step 610 , after the determination of a failover has occurred, but in other embodiments, it can be done continuously or periodically after failover. The live version of an object (at any level of the hierarchy) is the most current, consistent version of the object; i.e. it is the one that should be returned if a user requests the object. It is determined by finding the most recent version of the object such that all of the ancestors of the object within the hierarchy are live. This ensures that an object can only be accessed (such as on a failover to the secondary or in a read-only mode at the secondary) if all of the parent objects have also been replayed and committed and are still live on the secondary. If, after failover, a parent in the objects hierarchy does not exist, then the object is garbage collected. This is shown at a step 612 , but (as with the step 610 ) can be done continuously or periodically before failover as well for older versions of the object than the currently live version. In some embodiments of this garbage collection process, objects or versions of objects that are non-live or unreferenced are located in the data store and deleted or the storage they occupy is otherwise returned to available use. In other embodiments, clients are allowed to read from the secondary during normal operation (before failover), and the live version of the object is the most recent version of the object such that all of the ancestors of the object within the hierarchy are live.
An as example, consider a simple three-level hierarchy, with accounts which store containers which store blobs. The accounts, containers, and blobs are stored in their own are stored separately and they geo-replicate completely independently of one another. The method 600 also allows them to commit independently of each other at the secondary data store, since each object has the full identifier of all of its parents in the hierarchy. Consider the scenario of creating a container in the storage account and putting blobs into it. When this occurs, the container is created with a first version on the primary data store, and that creation is replicated to the secondary data store for the account. Similarly, when blobs are put into that container, those blobs are stored at the primary data store and also replicated to the secondary data store. All of the blobs are stored with the container name and version as part of their identifiers. Note that since blobs and containers are replicated independently the blobs may replicate before the container creation does. This means if a hard/abrupt failover to the secondary data store occurs due to a disaster at the primary data store, the container may never be replicated to the secondary data store, even though the blobs have been replicated and created on the secondary. This is not problematic, because the blobs will not be live, since the container was not created. A garbage collection process will clean up those orphaned blobs.
In a second scenario, a container with a given name is created, populated with blobs, and deleted repeatedly. We assume that in the embodiment being described, a delete of the container specifies that all blobs belonging to that container version should also be deleted. Since the container transactions are replicated and committed completely independently of the blob transactions, if a hard/abrupt failover to the secondary data store occurs, the version of the container that is the current live one on the secondary could be any recent version, and where the blobs are in their replication process is completely independent from the containers. After the failover, either the container will be live with some version, or it will be in its deleted state. If it is live with a given container version, then only blobs with that container version will be live, and the rest will be garbage collected. If, on the other hand, the container is in the deleted state, then all of the blobs will be garbage collected, since no version of the container is live.
Alternative embodiments and implementations of the present invention will become apparent to those skilled in the art to which it pertains upon review of the specification, including the drawing figures. Accordingly, the scope of the present invention is defined by the claims that appear in the “claims” section of this document, rather than the foregoing description.
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Presented herein are methods of replicating versioned and hierarchical data structures, as well as data structures representing complex transactions. Due to interdependencies between data entities and a lack of guaranteed message ordering, simple replication methods employed for simple data types cannot be used. Operations on data structures exhibit dependencies between the messages making up the operations. This strategy can be extended to various types of complex transactions by considering certain messages to depend on other messages or on the existence of other entries at the data store. Regardless of origin, these dependencies can be enforced by suspending the processing of messages with unsatisfied dependencies until all of its dependencies have been met. Alternately, transactions can be committed immediately, creating entities that include versioned identifiers for each of their dependencies. These entities can then be garbage collected of the parent objects are not subsequently created.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a flexible chip set encapsulation structure.
2. Description of the Prior Art
FIG. 1 is a perspective view of a conventional chip set encapsulation structure. The chip set encapsulation structure comprises a fixing film 1 . The fixing film 1 wraps a plurality of chips 2 to constitute a chip set 3 . When the chip set 3 is attached to the user's body, the chip set 3 will irradiate far infrared to the user. The far infrared can emit micro energy to the user. The micro energy is absorbed by the user's water molecules through resonance absorption to generate angle vibration so as to promote blood circulation and to enhance metabolism. The large water molecule is decomposed to small water molecule. The chip set also provides sterilization and deodorization effects.
However, the flexibility of the fixing film 1 of the conventional chip set encapsulation structure is not good and the chip set 3 cannot be curved at a large angel freely. When the chip set 3 is used, the use's movement is confined and the user cannot bend freely. The chip set 3 cannot be attached to the user's body completely to cause uncomfortable wear. Accordingly, the inventor of the present invention has devoted himself based on his many years of practical experiences to solve these problems.
SUMMARY OF THE INVENTION
The primary object of the present invention is to provide a flexible chip set encapsulation structure having good flexibility. The flexible chip set encapsulation structure can be bent freely, not confining movement of the user, and it is completely attached to the use's body to enhance the comfortable wear.
In order to achieve the aforesaid object, the flexible chip set encapsulation structure of the present invention comprises a chip set. The chip set comprises a plurality of spaced chips and a fixing film. The fixing film is adapted to wrap and fix the chips. The fixing film has at least one bending portion at a predetermined position for the fixing film to have flexibility in a predetermined direction.
Through the bending portion, the fixing film can be bent freely to form a flexible chip set having a good flexibility. When the user wears the flexible chip set, the user can bend freely, not limited to the flexible chip set encapsulation structure. The chip set is completely attached to the user's body. This provides a comfortable wear, and the chips provide a better far infrared radiation effect.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a conventional chip set encapsulation structure;
FIG. 2 is a perspective view according to a first embodiment of the present invention;
FIG. 3 is a schematic view of the first embodiment of the present invention when in use;
FIG. 4 is an exploded view according to the first embodiment of the present invention;
FIG. 5 is a sectional view according to the first embodiment of the present invention;
FIG. 6 is a sectional view according to the first embodiment of the present invention in a curved state;
FIG. 7 is a perspective view according to a second embodiment of the present invention;
FIG. 8 is a sectional view according to the second embodiment of the present invention;
FIG. 9 is a sectional view according to the second embodiment of the present invention in a curved state;
FIG. 10 is a perspective view according to a third embodiment of the present invention;
FIG. 11 is a perspective view according to a fourth embodiment of the present invention;
FIG. 12 is a perspective view according to a fifth embodiment of the present invention;
FIG. 13 is a perspective view according to a sixth embodiment of the present invention; and
FIG. 14 is a perspective view according to a seventh embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings.
FIG. 2 is a perspective view according to a first embodiment of the present invention. The present invention discloses a flexible chip set encapsulation structure 100 . The flexible chip set encapsulation structure 100 comprises a chip set 200 . The chip set 200 comprises a plurality of chips 210 spaced and arranged at a predetermined position and a fixing film 10 . The fixing film 10 is adapted to wrap and fix the chips 210 , so that the chips 210 can be separately confined and fixed in the fixing film 10 . In the first embodiment of the present invention, the fixing film 10 is made of a flexible EVA material, but not limited to this material. The fixing film 10 can be made of PE, TPR, TPU or the like material. The fixing film 10 has a plurality of bending portions 20 at a predetermined position. The bending portions 20 are disposed along the vertical direction and the transverse direction of the fixing film 10 , and staggered and spaced at the predetermined position of the fixing film 10 . The bending portions 20 are disposed at the relative position between the chips 210 of the fixing film 10 . In the first embodiment of the present invention, the bending portions 20 are a plurality of spaced recesses 21 for the fixing film 10 to be bent flexibly, so that the fixing film 10 is flexible in a predetermined direction and the fixing film 10 can be bent freely at the position of the bending portions 20 .
Referring to FIG. 3 to FIG. 5 , the chip set 200 is placed in a telescopic belt 300 . One side of the chips 210 is coated with an energy coating 220 . The material of the energy coating 220 comprises copper, carbon, silicon, manganese, phosphorus, sulfur, nickel, germanium, chromium, molybdenum, titanium, vanadium and so on which are mixed in a ratio for the energy coating 220 to radiate far infrared radiation energy. In the first embodiment of the present invention, the bending portions 20 are disposed along the long axis and the short axis of the telescopic belt 300 and spaced at the predetermined position of the fixing film 10 . The bending portions 20 are disposed at the relative position between the chips 210 of the fixing film 10 , so that the fixing film 10 is flexible along the long axis and the short axis of the telescopic belt 300 and the chip set 200 is flexible freely along with the telescopic belt 300 .
Referring to FIG. 5 , FIG. 6 and FIG. 3 , the flexible chip set encapsulation structure 100 has a flexible and curved space through the bending portions 20 . The fixing film 10 has the property of flexibility in the predetermined direction for the flexible chip set encapsulation structure 100 to be bent at a large angle, so that the chip set 200 has a good flexibility to be curved freely. The chip set 200 becomes a flexible chip set to be curved freely along with the telescopic belt 300 . Thus, when the chip set 200 cooperates with the telescopic belt 300 to wrap the waist of the user, the waist of the user is free to bend and move, not limited by the flexible chip set encapsulation structure 100 . Through the bending portions 20 , the chip set 200 can be completely attached to the body along with the flexibility of the telescopic belt 300 . This provides a comfortable wear, and the chips 210 abut against the body to provide a better far infrared radiation effect.
Referring to FIG. 7 to FIG. 9 , a second embodiment of the present invention is substantially similar to the first embodiment with the exceptions described hereinafter. The bending portions 20 are a plurality of spaced through holes 22 to provide a flexible and curved space, so that the fixing film 10 has the property of flexibility in the predetermined direction for the flexible chip set encapsulation structure 100 to have a good flexibility and that the chip set 200 can be curved freely.
Referring to FIG. 10 , a third embodiment of the present invention is substantially similar to the first embodiment with the exceptions described hereinafter. The chip set 200 is applied to an eyeshade. The chips 210 are arranged according to the position of the eyes and disposed at two sides of the fixing film 10 . The fixing film 10 is gradually reduced from its two ends toward the middle portion. The middle portion of the fixing film 10 is formed with a plurality of bending portions 20 which are disposed crisscross at a predetermined position along the vertical direction and the transverse direction of the fixing film 10 . In the third embodiment of the present invention, the bending portions 20 are spaced recesses 21 for the fixing film 10 to have a flexible and curved space. The fixing film 10 is flexible in a predetermined direction so that the fixing film 10 can be bent at a large angle freely at the position of the bending portions 20 . Thus, when the chip set 200 cooperates with the eyeshade to be used, the flexible chip set encapsulation structure 100 is flexible along the contour of the eye portion. Thus, the chip set 200 is completely attached to the body. This provides a comfortable wear, and the chips 210 abut against the body to provide a better far infrared radiation effect.
Referring to FIG. 11 , a fourth embodiment of the present invention is substantially similar to the third embodiment with the exceptions described hereinafter. The bending portions 20 are a plurality of spaced through holes 22 to provide a flexible and curved space, so that the fixing film 10 has the property of flexibility in the predetermined direction for the flexible chip set encapsulation structure 100 to have a good flexibility and that the chip set 200 can be curved freely.
Referring to FIG. 12 , a fifth embodiment of the present invention is substantially similar to the third embodiment with the exceptions described hereinafter. The bending portions 20 are crisscross disposed at the relative position between the chips 210 of the fixing film 10 . Each bending portion 20 is a recess 21 to provide a flexible and curved space for the fixing film 10 , so that the fixing film 10 has the property of flexibility in the predetermined direction for the flexible chip set encapsulation structure 100 to have a good flexibility and that the chip set 200 can be curved along the eye portion. Thus, the chip set 200 is completely attached to the body. This provides a comfortable wear, and the chips 210 abut against the body to provide a better far infrared radiation effect.
Referring to FIG. 13 , a sixth embodiment of the present invention is substantially similar to the first embodiment with the exceptions described hereinafter. The chip set 200 is applied to a knee pad. The chips 210 are circularly arranged at an equal angle. The fixing film 10 is formed in a circle to wrap and fix the chips. The fixing film 10 has a plurality of spaced bending portions 20 disposed at a predetermined position along an inner circumferential portion thereof and between the chips 210 . In the sixth embodiment of the present invention, the bending portions 20 are a plurality of spaced recesses 21 for the fixing film 10 to be bent flexibly, so that the fixing film 10 is flexible in a predetermined direction and the fixing film 10 can be bent freely at the position of the bending portions 20 . Thus, when the chip set 200 cooperates with the knee pad to be used, the user can curve his/her knee freely, not limited to the flexible chip set encapsulation structure 100 . The flexible chip set encapsulation structure 100 is flexible along the contour of the knee pad. Thus, the chip set 200 is completely attached to the body. This provides a comfortable wear, and the chips 210 abut against the body to provide a better far infrared radiation effect.
Referring to FIG. 14 , a seventh embodiment of the present invention is substantially similar to the sixth embodiment with the exceptions described hereinafter. The bending portions 20 are a plurality of spaced through holes 22 to provide a flexible and curved space, so that the fixing film 10 has the property of flexibility in the predetermined direction for the flexible chip set encapsulation structure 100 to have a good flexibility and that the chip set 200 can be curved freely.
Although particular embodiments of the present invention have been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the present invention. Accordingly, the present invention is not to be limited except as by the appended claims.
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A flexible chip set encapsulation structure includes a chip set. The chip set comprises a plurality of spaced chips and a fixing film. The fixing film is adapted to wrap and fix the chips. The fixing film has at least one bending portion at a predetermined position for the fixing film to have flexibility in a predetermined direction. Thus, the flexible chip set encapsulation structure is flexible for bending. When the user wears the flexible chip set, the movement of the user won't be confined. Besides, the chip set is completely attached to the body to provide a comfortable wear, and the chips provide a better far infrared radiation effect.
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FIELD OF THE INVENTION
This invention relates to the field of bathtubs, especially bath tubs which are adaptable to the changing demands of those who have decreasing abilities to care for themselves.
BACKGROUND OF THE INVENTION
Innumerable studies and publications report "The Graying of America", i.e., the percentage of the population which is "aged" or "chronologically gifted" is constantly increasing. What is certain about this phenomenon, but much less frequently mentioned, is the declining capacity of the aged to care for themselves. It has been concluded, sadly, that when such necessary activities as food preparation, hygenic functions, grooming, and the like, consume the entire day, the quality of life is zero. In other words, there no longer is time for elective and pleasurable pursuits.
The logical solution to the reduction of abilities through ageing is the application of resources, human and mechanical, to ease the performance of these tasks by bringing the aid to the person and by bringing the person to the aid.
Although ageing persons generally realize that disabilities of one sort or another have made life more arduous, nearly all desire to remain among famililar and friendly surroundings and companions. For the large number who resist relocation, help is sought in the form of mechanical devices. But what is highly important in the minds of the ageing is that any mechanical help must not appear to be too different from their usual environment. Especially, it must not be suggestive of a hospital or nursing home. The strong tendency is to avoid as long as possible anything that labels them as "frail" or "old" or "infirm".
Bath tubs and wall enclosures already known are shown in U.S. Pat. Nos. 3,588,925 and 4,080,710. The invention of U.S. Pat. No. 4,592,099 provides ample assistance to many disabled, but some find little immediate need for all the benefits that this bathing system makes available, recognizing, of course, that it will be desirable in the future.
BRIEF SUMMARY OF THE INVENTION
The instant invention resides in tub surround panels useful with a conventional bath tub or with a tub configured to the special needs of the disabled. Unobtrusively reinforced side panels are recessed to accept a full length chair height reclining shower seat and a tilting bath tube to contain the bathing water for use when these bathing aids are necessary or desireable. When they are no longer needed, the seat and tube are easily removed and the side panels and back wall are restored to their original appearance. The invention will be more fully understood from the following drawings and description.
THE DRAWINGS
FIG. 1 is a view of a tub surround including the recessed side panels atop a conventional style bath tub.
FIG. 2 is a view of reclining bath and shower seat and its supporting accessory.
FIG. 3 is a view of a tiltable bath tube.
FIG. 4 is a view showing an assembly of the parts of FIGS. 1, 2 and 3.
DETAILED DESCRIPTION
Referring to FIG. 1, there is shown a bath tub 10 having a rim 11. The tub may or may not have been modified in detail to accomodate the special needs of the mobility impaired. A surround to protect the bathing enclosure from splashed water includes an upstanding first side panel 12 having a front edge 13 and a rear margin 14. An opposed upstanding second side panel 15 has a front edge 16 and a rear margin 17. A back wall 8 connects the side panels at their rear margins. The panels 12 and 15 and the back 8 surmount the tub and are joined to the rim 11 with a water tight seal. Constructing the surround and tub as separate elements overcomes the bulkiness of a one piece unit which may be difficult or impossible to transport through narrow passages to the bathroom location. This is especially true in remodeling work.
The side panels have opposed matching recesses which open to the respective front edges of said side panels. In a preferred embodiment, side wall 12 has an upper recess 18 and a lower recess 19; side wall 15 has an upper recess 20 and a lower recess 21. The recesses have lower surfaces 22, 23, 24, and 25 respectively which open to the front edges of the walls. In a preferred embodiment the surfaces 22, 23, 24 and 25 are substantially horizontal. The upper surface of each recess diverges slightly from the lower surface so that the vertical dimension of each recess is greatest where it meets the edge of the side wall.
The surround, bath and shower seat and tiltable tube are constructed of fiberglass reinforced polyester laminate with a sanitary gel coat but other suitable materials may be used. The areas 26 and 27 behind the recesses are reinforced during manufacture by molding in a strengthening material of suitable characteristics and dimensions. Marine plywood is one such material.
Also shown in FIG. 1. are molded-in hselves 28, 29, 30, 31, 32 and 33 which are of sufficient strength and of appropriate configuration to serve as supplemental body support surfaces to conveniently aid the bather when entering or leaving the tub or also to hold bath materials such as soap, shampoo and the like. The water control 34 is located above a cascade water discharge 35 and also controls the shower spray head 36 which rides on a positioning bar 37. Grab bars 38 and 39 are provided for additional support to a bather.
Referring to FIG. 2 there is shown a reclining bathing and shower seat 40 having a rest 41 at the top of the back 42. The foot end 43 is secured with a hinge 44 or other suitable movable mount. A counter balancing apparatus (not shown) is located within console 45. Optional water controls may also be mounted on the console.
Referring to FIG. 3, there is shown a bath tube 50 which is tiltable about pivots 51 and 52. Drain apparatus 53 is operated remotely by knob 54.
When a bather or the bather's caregiver elects to transform the bath apparatus of FIG. 1 to that of FIG. 4, plate 55 is removed to expose a latch on the back wall 8. The pivots 51 and 52 on tube 50 are placed on surfaces 23 and 25 of the lower recesses 19 and 21 and moved toward the back wall 8 until they reach the limit of the recess. The pivots are secured in this location with blocks 60 and 61 which are attached with bolts inserted in predrilled holes. When not needed the holes are concealed with removable caps. Handle 62 is inserted to operate the latch which engages a detent on the tube to maintain it in either an open inclined position shown in FIG. 4 or horizontal closed position. The counterbalance mechanism inside the console 45 is located on the surface 24 in the recess 20 and fastened to the wall at that location with bolts inserted in predrilled holes. The top 41 of the seat 40 then engages and rests on the surface 22 of the matching opposed recess 18.
To take a bath, a bather sits on the seat as one might sit on the edge of a bed, and once seated, swings the feet onto the foot 43 of the seat 40. Water spray may be started over the bather at this time, or the tube 50 may be first tilted to the horizontal position by releasing the latch with handle 62 and moving the tube to the horizontal or soaking position. In this position, overflow 63 directs any excess water to the drain. While there is water in the tube, a float interlock prevents accidental tilting from the horizontal. Upon completion of the bath, the water is released by rotation of knob 54 and when the water level is low enough to release the interlock, the handle 62 is moved to release the latch and permit returning the tube to its original inclined position so the bather may exit. It is a considerable advantage that while entering or leaving the tube the bather need never support his weight on his feet while they are on a wet and/or slippery surface.
To wipe the interior of the tube, the reclining seat 40 is lifted to provide improved access, an operation which is greatly aided by the counterbalance concealed in the console 45.
Should a bather recover from an infirmity and desire to return to use of the apparatus of FIG. 1, the seat 40 and tube 50 are readily removed by reversing the installation steps described above and replacing the concealing caps in the now empty bolt holes.
The embodiments described above and illustrated in the drawings are, of course, to be regarded as non-limiting examples and as to their details may be modified in several ways within the scope of the following claims.
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A bathing device including tub surround panels useful with a conventional bath tub or with a tub configured to the special needs of the disabled. The panels have unobtrusively reinforced side panels recessed to accept a full length chair height reclining shower seat and a tilting bath tube to contain the bathing water for use when these bathing aids are necessary or desirable. When they are no longer needed, the seat and tube are easily removed and the surround panels are restored to their original appearance.
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[0001] The present application claims priority from U.S. Provisional Application Ser. No. 61/872,344, filed Aug. 30, 2013, which is incorporated by reference herein in its entirety.
FIELD OF INVENTION
[0002] A control system and associated methodology and apparatus for the implementation of an eductor-mixer technique providing the capability for injecting proppant material into a non-aqueous fracturing fluid stream utilized in hydraulic fracturing operations is described. The system and apparatus includes an eductor, an enclosed vessel that provides a proppant reservoir, valving disposed between the eductor and the enclosed vessel, and a pressure control system for modifying the pressure in the enclosed proppant vessel during the fracturing operation. The control system employs a combination of control valve position and proppant reservoir pressure to adjust and set proppant feed rates into an eductor to be mixed with a non-aqueous fluid and to control proppant concentrations into a fracturing fluid stream.
BACKGROUND OF THE INVENTION
[0003] The use of carbon dioxide for enhanced production of oil and gas from reservoirs is well known. Liquefied gas based fracturing is unique as compared to conventional fluids such as water and have certain advantages in water sensitive and low pressure formations, including the promotion of fluid flowback (i.e., retrieval of water/fluid used in fracture treatment) which minimizes formation damage caused by water. Michael J. Economides, T. M. (2007). Modern Fracturing: Enhancing Natural Gas Production. (S. Weiss, Ed.) Houston, Tex., USA: Energy Tribune Publishing Inc. LCO 2 used in fracturing treatments is typically added to a high pressure stream of water and proppant (typically solids, such as sand, polymer pellets, tracers, gravel, etc. of various sizes and density) at the well-head. Combining water with proppant and adding a separate pressurized LCO 2 stream is the most conventional method of forming a CO 2 -energized fracture fluid. This is due, in large part, because it is simpler to mix proppant with water at atmospheric pressure then it is to add proppant to liquid carbon dioxide at a pressure above the triple point of carbon dioxide, (i.e., greater than 75.1 psia).
[0004] Equipment is available and can be used for small fracture treatments (e.g. to place up to approximately 20 tons of proppant) to mix proppant directly with a liquid carbon dioxide-based fracturing fluid. This equipment includes a pressurized vessel and manifold system that blends the proppant into a liquid CO 2 stream prior to the high-pressure pumps. Proppant is loaded into the CO 2 blender. The blender is sealed and then filled with CO 2 . During the fracturing process, proppant is mixed into the fracturing fluid by either hydraulically driven augers or gravity fed through a control valve. Michael J. Economides, T. M. (2007). Modern Fracturing Enhancing Natural Gas Production. (S. Weiss, Ed.) Houston, Tex., USA: Energy Tribune Publishing Inc. Once the batch of LCO 2 and proppant is exhausted, the fracture treatment must either be completed or suspended to refill the blender with additional proppant.
[0005] Earlier efforts, as described in U.S. Pat. No. 4,374,545, provide for a batch process creating a proppant and LCO 2 fracturing slurry. Each unit is capable of metering up to 20 tons of a single type of proppant and addresses the control of proppant supply through the use of a metering auger. LCO 2 additions made to the bottom of the tank allow for a flowable and vapor-free proppant slurry leaving the system as well as maintaining pressure in the vessel.
[0006] Another system is described in U.S. Pat. No. 8,408,289 and U.S. Pat. No. 8,689,876 which depict an upright standing vessel where proppant is metered into LPG (liquefied petroleum gas) as a base fracturing fluid. Proppant loadings are varied into the LPG fracturing fluid stream through the use of gravity (through a control valve) or via one or more augers disposed within and along the bottom of the proppant supply source or arranged outside of the proppant supply source. Inert gas (in the form of nitrogen) is pumped into the vessel during operation to maintain vessel pressure to ensure the LPG mix remains in the liquid phase to prevent back flow into the vessel.
[0007] A non-mechanical pump, such as an eductor, can be used to mix a proppant into a fracturing fluid stream. Non-mechanical pumps have the benefit of no moving parts, are generally low cost and simple pieces of equipment, and are already commonly used in related material introduction. For instance, International Publication No. WO 2012087388 describes an eductor system for introducing and blending polymer additives into a fracturing fluid stream.
[0008] General use of a liquid eductor for solids handling and blending relies heavily on the relationship of motive flow (i.e., the incoming flow of fluid to the eductor (without proppant addition)) to the rate of solids entrainment for the control of solids concentration. As liquids pass through the converging nozzle of the eductor, potential energy is converted into kinetic energy resulting in a high velocity jet flow. This change in energy results in a localized decrease in static pressure that creates suction within the body of the eductor. This suction allows material to be drawn into the eductor and entrained by the fluid (LCO 2 , etc.). The eductor serves a dual purpose: mixing within the nozzle as well as drawing material into the fluid to ensure intimate mixing. With more conventional methods, such as using sand or similar material proppants to provide water-based slurries, the viscous properties of the water aids in drawing solid materials into the body of the eductor where suction occurs. Difficulty arises when it is necessary to establish a particulate suspension in a relatively low viscosity fluid (as compared to water), such as liquid carbon dioxide (LCO 2 ). The present invention addresses the need to add proppant to such fluids on a more fully controlled basis by delivering a homogeneous fracturing fluid to high pressure pumpers prior to wellhead injection.
[0009] A system and method described in U.S. Pat. No. 7,735,551 is used to blend nitrogen gas with proppant to fracture an underground oil and gas formation or coal seam. The proppant and gas mixing occurs at a pressure sufficient to fracture the formation. In one embodiment, an eductor is employed to introduce proppant into the vapor stream and is in communication with the well bore. Proppant material is either gravity fed from a proppant reservoir into the eductor with the use of a control valve or regulated in with the use of an auger. The system described provides for the use of either valve position or auger speed to regulate proppant into the vapor stream to achieve specified proppant loadings. Pressure in the head space of the proppant reservoir is maintained at a constant value during the entirety of the stimulation.
[0010] To overcome the disadvantages of the related art, it is an object of the present invention to provide a control mechanism for operating a system for the delivery of proppant into a liquefied gas, such as LCO 2 , for the purpose of fracturing a subterranean formation. Although the liquefied gas discussed herein is in relation to LCO 2 , by way of example, it can be combination of immiscible and non-immiscible fluids such a CO 2 and methanol, CO 2 and biodiesel, or CO 2 and water. Specifically, the control mechanism developed utilizes an eductor along with a proppant control valve and the pad pressure (as defined below) in the proppant reservoir to control proppant loading at specified concentrations in a substantially homogeneous fashion.
[0011] It is another object of the present invention to provide a system designed to mix proppant and fracturing fluid at pressures significantly below that of the surface treatment pressure (e.g. at or below 400 PSI).
[0012] It is yet another object of the present invention to provide a system where the eductor can be used with a liquid, and wherein said system does not utilize an auger for purposes of metering proppant into fracturing fluid.
[0013] Other objects and aspects of the present invention will become apparent to one skilled in the art upon review of the specification, drawings and claims appended hereto.
SUMMARY OF THE INVENTION
[0014] The present invention describes a system and associated apparatus for modifying entrainment rates of proppant with liquefied gas or a relatively low viscosity (that is less than water at 1 centiPoise—cP) liquid, (e.g. carbon dioxide) using an eductor. More specifically, this system employs the use of a proppant reservoir, valving, an eductor, and a pressure source to provide the proper concentration of proppant in a flowing stream of fracturing fluid for use in stimulating subterranean formations such as new and existing oil and gas wells. An auger is not used to meter proppant flow in the present invention. The vessel is sealed from the atmosphere in order to achieve proper pressure modification. Operating pressure of the equipment in the present invention, including the proppant reservoir and the eductor, is in the range of about 100 to 400 PSI.
[0015] A solids-conveying liquid eductor is used to mix and accelerate proppant within the main liquid stream. The eductor can be varied in size (with different nozzle and tail) to accommodate the flow rates required for the particular well. Once the flow requirement for the motive stream has been determined, a control system is implemented. The control system utilizes at least one valve for controlling the flow of proppant from one or more pressurized proppant reservoir into the eductor; thereby mixing the material with the motive stream. Gas and/or liquid is fed to the top of the proppant reservoir to control the static pressure (as defined below) inside the proppant reservoir. Modifying the static pressure inside the proppant reservoir extends the range of achievable proppant flow rates from the reservoir into the eductor.
[0016] In one aspect of the invention a method of controlling a proppant concentration in a fracturing fluid that is utilized in stimulation of an underground formation is provided. The method includes:
[0017] supplying a motive fluid flow of liquefied gas at pressure between about 150 to 400 psig to an eductor, wherein the liquefied gas is mixed with the proppant or proppant slurry in the eductor to form a fracturing fluid, wherein the pressurized proppant reservoir is disposed in a position to supply the proppant slurry to at least one eductor;
A. varying the pad pressure in the pressurized proppant reservoir from about −30 to 40 psi; and B. further varying a proppant control valve disposed between the eductor and the pressurized proppant reservoir to control the proppant concentration in a range from about 0.1 to 10 lbs/gal of proppant in the fracturing fluid.
[0020] In another aspect of the invention, a system for controlling proppant concentration in a fracturing fluid that is utilized in stimulation of an underground is provided. The system includes:
A. providing a proppant reservoir having a proppant or proppant slurry therein; B. providing an eductor to receive a motive fluid flow of liquefied gas, wherein the eductor is disposed below the proppant reservoir and forms a fluid containing proppant at the outlet of the eductor upon receiving the proppant or proppant slurry from the proppant reservoir; and C. providing a proppant control valve disposed between the proppant reservoir and the eductor, wherein the pad pressure in the proppant reservoir is varied from about −30 to 40 psi to attain a concentration range from about 0.1 to 10 lbs/gal of proppant in the fracturing fluid.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The above and other aspects, features, and advantages of the present invention will be more apparent from the following drawings, wherein:
[0025] FIG. 1 is a plot that illustrates the differences between the motive flow rate and the effect of sand/proppant mass flow comparing the use of water and liquefied carbon dioxide.
[0026] FIG. 2 is a plot showing the effect of pad pressure on the concentration of proppant in the fracturing fluid stream through various positions of a computer controlled valve.
[0027] FIG. 3 is a schematic depicting an embodiment of the blender/reservoir system which provides controlled injection and mixing of proppant with a liquefied gas fluid for fracturing a geological formation utilizing an eductor.
[0028] FIG. 4 is a further illustration of another embodiment of the overall system indicating certain process control aspects.
[0029] FIG. 5 is a graphical representation of various proppant control valve positioning at low pad pressures at a motive flow rate of 23 gal/min.
[0030] FIG. 6 is a graphical representation of various proppant control valve positioning at high pad pressures at a motive flow rate of 23 gal/min.
DETAILED DESCRIPTION OF THE INVENTION
[0031] The present invention involves a system and apparatus for providing a continuous or semi-continuous supply of fracturing liquid, where the flow rate and method of controlling the flow rate utilizes an eductor so that proppant can be thoroughly mixed with the fluid during creation of a fracturing fluid stream and is controlled through the use of control valves and proppant reservoir pressures. As employed herein, “fracturing fluid” or “fracturing liquid” are used interchangeably, and refers to the product routed downstream to the fracturing pump. The eductor and associated valving must be properly sized in order to provide efficient acceleration of the proppant and resulting combined fluid proppant slurry at the desired concentration—depending on the required fracturing liquid flow rate. Eductors that may be employed includes for example, jet pumps, ejectors, venturi pumps, siphon pumps, aspirators, mixing tees, injector pumps, etc. The eductors can include a variable size nozzle or aperture, which may be controlled through a programmable logic controller, or the like, to maintain net positive suction head (NPSH) pressure downstream of the proppant reservoir, discussed below. This enables the use of a broad range of flow rates without changing the nozzle or the eductor itself. On the suction side of the eductor, a large reservoir (referred to as the proppant reservoir) is positioned for holding either dry proppant or proppant slurry (a mixture of proppant and liquefied gas potentially with other additives). The flow of proppant or slurry from the reservoir to the fluid stream is controlled by a valve disposed between the eductor and the reservoir. For the purposes of the present disclosure, this valve will be referred to as the “proppant control valve”. This proppant control valve can be one of many types including that of a sliding gate, knife valve, pinch valve, and choke valve. The proppant is loaded into the reservoir either via a hatchway or through pneumatic filling and then the vessel is sealed. Dry gas(es) or liquefied gases may then be added to the system. Dry gas is usually added to the top of the reservoir in order to prevent the aerosolization of proppant.
[0032] Liquefied gas can be added through the bottom of the reservoir through the separate liquid line (denoted as the liquid addition line) attached to the bottom of the vessel or alternatively into the suction side of the eductor. Liquefied gas is added to the bottom of the reservoir initially to prevent the formation of gas pockets. During the fracturing treatment, liquefied gas may also be added to the bottom of the reservoir in order to promote the formation of a solid-liquefied gas suspension.
[0033] Preparation of the system and use of the apparatus to conduct the process methodology is generally described as follows: proppant is loaded into the proppant reservoir and the reservoir is pressurized with gas to a pressure above the triple point pressure of the liquefied gas to ensure liquid remains in the reservoir as liquefied gas is added.
[0034] Once the motive flow has been established, the proppant control valve is opened to commence mixing proppant material with the fracturing fluid stream. The proppant loading in the fracturing fluid and/or the flow rate of the combined stream are normally measured by the use of a nuclear densitometer, a magnetic flow meter, a Coriolis meter or other suitable measurement devices. In the present invention, adjustments of the opening of the proppant control valve position (i.e., between various size openings) is determined based on the measured concentration of the solids either via manual methods or through the use of an automatic, computer controlled, control loop. The control of the opening and closing of the valve allows for proper metering of the proppant to the eductor. The concentration of solids in the fracturing fluid is synonymous with proppant loading. Adjustment of the static pressure in the proppant reservoir is used to provide a greater range of operability of the valve (as described in detail, below). Metering of the proppant by adjusting the proppant control valve and static pressure in the proppant reservoir allows for providing the desired loading of the proppant on a per gallon (or other unit of liquid measure) basis of fracturing fluid. This loading or concentration is normally in the range of at least 0.1 to 10 lbs per gallon. An even more preferable range for certain fracturing operations is between 0.1 and 4 lbs/gallon.
[0035] The use of pad pressure (defined in this invention as the difference in pressure in the headspace of the proppant reservoir and the outlet of the eductor) provides the requisite static pressure that extends the overall capability to attain the desired proppant loadings. The static pressure in the reservoir, in the present invention, is measured as the difference in pressure at the bottom of the reservoir compared to the pressure measured at the discharge of the eductor pump.
[0036] Changes in static pressure are generally achieved by controlling the flow of pressurized gas (such as gaseous carbon dioxide or nitrogen) or liquid (such as liquefied carbon dioxide) fed to the top of the proppant reservoir. In addition, a pressure relief control valve may be used to release excess pressure in the reservoir's head space. Ideally, pad pressure is varied over the course of the fracturing operation and the range of operation is maintained between −20 and 30 psi. Excessive pad pressure can result in higher proppant loading than desired in the fracturing fluid stream. A pad pressure that is too high could result in an increased sensitivity of the proppant control valve and precise control of the desired proppant concentrations could be more difficult to achieve. In this case, the pad pressure should be decreased. Alternatively, a pad pressure that is too low can result in limiting proppant flow from the proppant reservoir such that the concentration of proppant in the fracturing fluid is lower than the set point. In this case, the pad pressure should be increased.
[0037] Operating static pressures and eductor discharge pressures must be maintained in excess of the vapor pressure of the fracturing fluids at the operating temperature and/or exceed a required NPSH. For instance, maintaining the proper pressure to ensure liquid carbon dioxide (LCO 2 ) remains a single phase fluid (liquid) within the high pressure fracturing pumps requires approximately 50 psi NPSH, or at least a pressure sufficiently above saturation conditions for normal, safe, and reliable operation of the high pressure pumps. Significant amounts of vapor or a provision of lower NPSH fluid risks vapor lock or cavitation. These conditions will negatively affect performance and can damage the high pressure pumps. Because of the risk of vapor lock and cavitation, operators must be cognitive of pressure drops required to ensure proper eductor pump operation.
[0038] Recommended operational pressure ranges for eductor pumps is normally between 15 psi and 60 psi, depending on the available “disposable” NPSH (or pressure available to the operator to ensure proper eductor performance while maintaining sufficient pressure above saturation as described above). Motive flow rates failing to produce at least a 10 psi or greater pressure drop in the eductor will result in improperly cleared proppant or proppant flooding in the downstream piping.
[0039] A bypass line for the fracturing fluid is connected around the eductor and may also be utilized to provide for increasing flow rate capabilities of fracturing fluid without incurring higher pressure drops across the eductor pump or to further dilute the concentration of the proppant in the fracturing fluid leaving the eductor. This is especially beneficial when higher than expected flow rates of fracturing fluid are required so that an appropriate level of net positive suction head (NPSH) can be maintained. For instance, if a fracturing treatment requires a pumping rate of 40 BBLS/min and the installed eductor is only capable of operating up to 30 BBLS/min before the discharging pressure is in danger of maintaining the necessary NPSH, 10 BBLS/min flow can be bypassed around the eductor, resulting in a total flow of 40 BBLS/min, at a cost of reducing the maximum proppant concentration producible by the blending unit into the fracturing fluid stream.
[0040] The actual operation of the system is described using two separate stages;
A. The Pre-Startup Stage:
[0041] During pre-start up, the following steps are followed:
(1) The proppant reservoir is isolated from the eductor and proppant/sand is loaded into the proppant reservoir through either the port located on the top of the reservoir or through pneumatic fill lines. (2) The proppant reservoir is then pressurized using the vapor addition line at the upper part of the reservoir. (3) The proppant reservoir vessel is then filled with liquid through a liquid line located at the lower part of the vessel.
a. Concurrently, liquid additions could be provided to the top of the proppant reservoir either for filling or maintaining liquid levels in the reservoir. b. The pressure relief control valve is used to maintain a prescribed pressure in the proppant reservoir during filling.
(4) Once filling is completed, the operational stage can begin.
B. Operational Stage:
[0000]
(1) The fluid or motive is pumped down the main fluid line through the eductor.
a. A bypass line which bypasses the eductor may be used to extend fracturing fluid flows rates beyond the limitations caused by the pressure drop through the eductor, and possibly prevent cavitation of the downstream pumps.
(2) The proppant control valve is then opened and proppant is allowed to mix into the main fluid line within the eductor.
a. An isolation valve could be located next to the proppant control valve to act as a seal in the event that the proppant control valve does not function as a leak tight valve.
(3) Pad pressure is regulated to a set value. Pad pressure is increased by flowing pressurized gas (or liquid) to the top of the proppant reservoir. Pad pressure is decreased by opening the pressure relief control valve.
(4) The proppant control valve opening is adjusted to achieve the desired proppant concentration in the fracturing fluid.
(5) The pad pressure can be adjusted to a new value to extend the range of concentrations achievable.
[0055] FIG. 1 shows the relationship of proppant entrainment rate versus the motive flow rate (i.e., the flow rate of the water or liquid CO 2 flowing to the eductor) using a model 264 eductor manufactured by Schutte & Koerting. In FIG. 1 , the line labeled “[1]” depicts the performance of the eductor pumping a proppant and water slurry using water as a motive fluid (as a “baseline” for comparison). The area and points marked “[2]” indicate similar conditions but instead LCO 2 has replaced water as the motive and suspension fluid. The low viscosity of liquid carbon dioxide (again as compared to that of water) is believed to account for the differences in trends between motive flow and entrainment rates and thereby requires a control strategy as provided in the present invention.
[0056] FIG. 2 illustrates the proppant concentration as a function of pad pressure and proppant control valve (for example, an equal-linear type valve) position using liquid carbon dioxide as a fracturing fluid. FIG. 2 illustrates obtainable proppant concentration as a function of pad pressure and proppant control valve openings. As shown herein, the control system functions over a pad pressure ranging from −25 to +30 psi, and may still function over a range of −30 to +40 psi. In the present invention pad pressure is used as a means of coarse control of proppant loading while proppant control valve opening is used as a means for fine tuning the proppant loading.
[0057] FIG. 3 depicts an overview of the process using a flow diagram showing the basic elements of the present invention. Liquid carbon dioxide (LCO 2 ) fluid is supplied as stream 101 . Typically, stream 101 would be supplied from a liquefied gas boost pump. The pressure of stream 101 is typically between 200 and 400 psig. The LCO 2 is routed through an eductor 104 and is mixed with proppant from the proppant reservoir 102 , which is oriented in a position sufficient to provide proppant to the eductor, and preferably in a vertical or near vertical position. Moreover, the fluid in proppant reservoir 102 , can be subcooled to provide the requisite NPSH downstream. For instance, decreasing the pressure in the reservoir and/or subcooling the liquid in the reservoir so the requisite NPSH is achieved. The eductor 104 serves the dual purpose of causing mixing within process piping as well as providing suction for drawing the proppant from the reservoir 102 , thereby resulting in some degree of homogeneity in the product stream 107 . Typical LCO 2 flow rates in a stream 101 for this system will be between 10 and 80 BBLS/min. An appropriate converging nozzle size in the eductor 104 is selected to produce a pressure drop of between 30 and 50 PSI for a selected liquid/motive flow 101 . The recommended pressure drop in operation of the eductor 104 is between 15 PSI and 60 PSI, depending on the available “disposable” NPSH of the stream 107 . During the fracturing operation, a proppant control valve 105 regulates the flow of proppant or proppant slurry from the proppant reservoir 102 into the eductor 104 . One or more of these eductors can be placed and connected in parallel and perform as a single device. For instance, the two seven inch eductors can be utilized in place of a single nine inch eductor, depending on the flow rate necessitated. The eductors and other components of the system can be modularized, variable and switched out of the system. The meter 106 could be any one of or a combination of a nuclear densitometer, Coriolis meter, or other suitable measurement device that provides feedback on fracturing fluid loading concentration, density, or other parameter capable of determining proppant concentration prior to well head injection. The proppant control valve 105 opening can be adjusted based on the readings provided by meter 106 . The volume of pressurized liquid or gas 103 supplied to the top of the proppant reservoir 102 allows for modification of the static pressure ranging from about 80-400 psi inside the proppant reservoir 102 . An adjustment in the system's static pressure changes the overall flow capacity of proppant control valve 105 . The resulting LCO 2 and proppant fracturing fluid is supplied to high pressure pumpers via stream 107 . For a given or predetermined motive flow rate, either the proppant control valve 105 or the pad pressure, or both, is utilized to achieve the desired concentration by metering the proppant solution into the motive flow. In an alternative embodiment, a phase separator (not shown) or refrigeration system (not shown) can be utilized to remove vapor and provide condensed fracturing fluid after the eductor to the high pressure pumpers.
[0058] FIG. 4 is a schematic that illustrates another embodiment of the present invention. In this embodiment, a parallel slipstream 302 of LCO 2 can be provided that bypasses the eductor 305 . This could be useful, for example, during the stages of the fracturing operation where no proppant is required (commonly referred to as the pad or padding stage). This bypass stream 302 can also be used to assist in controlling the final proppant loading. The flow into stream 302 and the motive stream 301 is controlled by flow control valves 304 and 303 , respectively. The flow of the motive stream 301 is routed into eductor 305 where a proppant control valve 306 regulates the flow of proppant from the proppant reservoir 315 into eductor 305 . An isolation valve 307 , located between the control valve 306 and the proppant reservoir, is used to isolate the proppant reservoir 315 from the eductor 305 . LCO 2 liquid is injected through line 308 to the bottom of the reservoir 315 to promote a liquid-solid suspension. Flow in line 308 is regulated by flow control valve 309 and actively provides for stirring of the proppant within the reservoir 315 during operation. This creates a dynamic dispersion that aids removal of proppant from the reservoir 315 and promotes uniformity and a degree of homogeneity of the slurry prior to entering eductor 305 . A similar LCO 2 line 310 regulated by another flow control valve 311 provides fluid to the top portion of reservoir 315 . This fluid is used to maintain a liquid CO 2 level above the proppant level in reservoir 315 to ensure that gas from the head space of the reservoir 315 does not enter eductor 305 and prevents vapor from passing through to the high pressure pumpers via line 317 . Furthermore, maintaining this liquid cap also facilitates the flow of proppant from the reservoir 315 by reducing clumping and improving the flow behavior of the proppant. A pressurized gas line 312 can be utilized for injecting vapor to the top of the reservoir 315 for modification and control of the static pressure of the reservoir 315 . Examples of gases that could be used to adjust the pressure include, but are not limited to carbon dioxide and nitrogen. The flow of pressurized gas into the proppant reservoir 315 is controlled through the use of a pressure control valve 313 . Working in conjunction with the pressure control valve 313 is a pressure relief control valve 314 . This valve works to relieve excess pressure stored in the head space of the proppant reservoir 315 . The pressure in the head space of the proppant reservoir 315 can be both raised and lowered during operation via control valves 313 and 314 . Head space pressure changes in the reservoir 315 results in an alteration of the overall flow capacity of the proppant loading control valve 306 . A density meter 316 is used to determine the proppant loading during operation. The density reading data is used to modify the proppant control valve 306 opening in order to achieve a desired concentration. Fracturing fluid stream 317 is then sent to the high pressure pumpers. The high pressure pumpers further increase the pressure of the proppant and liquefied gas stream to surface treatment pressure and are in communication with the well head.
[0059] The control system and methodology for arriving at the desired proppant concentration is further explained in the Working Examples below. These examples, however, should not be construed as limiting the present invention.
Working Example 1
Motive Flow Rate of 20 BBLS/Min
[0060] The data below in Table 1 provides a simulated example where the reservoir pad pressure (PP) and percent valve opening (VP) requirements (for a proppant control valve with a flow coefficient (CV) of 200) to obtain desired proppant concentrations from 0.25 to 4 lbs of proppant per gallon of LCO 2 in a fracturing fluid slurry as prescribed by a fracturing treatment schedule. The treatment schedule is utilized to provide a “pre-programmed” set of instructions (i.e., a PLC controller recipe is loaded into the system, and which communicate with the proppant control valve and adjust the pad pressure in the reservoir via the control loops). Naturally, an operator may manually override the recipe if necessary to modify the concentration of proppant in the slurry. Determining the control valve position and operating head pressure in the proppant reservoir is first determined through an iterative process carried out in the field. During fracturing operations, the pressure in the reservoir is adjusted to provide the designated pad pressure (PP) and valve position (VP) necessary in order to achieve the desired concentration based on a selected motive flow rate and the flow coefficient of the proppant control valve. The treatment schedule cannot be established without the proper determination of the pad pressure and proppant control valve position. In order to create the ability to provide a range of low end proppant loading to high end proppant loading, it is necessary to vary pad pressure to achieve proppant loading within predetermined ranges. The motive flow rate is set by determining the specific pumping rate required for the fracture treatment.
[0061] The system (such as described in any one of the exemplary embodiments above) is initially set at a low pad pressure, in this given example, a low pad pressure of −15 PSI is used. Setting the system at this low pressure allows for achieving better control of low proppant loadings (e.g. 0.25, 0.50 lbs/gal) using the proppant control valve. The proppant control valve is initially adjusted to increase proppant concentration in the fracturing fluid stream as prescribed by the treatment schedule, which is loaded in the PLC controller. In the example given the valve is adjusted from 10% to 40% open to achieve proppant loadings from 0.25 to 1.5 lbs/gal. After 1.5 lbs/gal is reached, the pad pressure is increased in order to better achieve higher proppant loadings (e.g. 3.5, 4.0, 4+, lbs/gal). In the example the pad pressure is adjusted from −15 PSI to 15 PSI. The pressure increase is done in a fashion were it has minimum impact on the proppant control valve position (in the example given this is done at 1.5 to 2.0 lbs/gal) and therefore is done at a specified loading. Once the new pad pressure has been established the process is completed through adjustments with the proppant control valve.
[0062] The following is done to minimize operational complexity: the head pressure is changed only once through the process; the system is adjusted using only one parameter at a time (either head pressure or proppant control valve position is changed, not both) or if two parameters are adjusted, one is changed minimally; the proppant control valve and pad pressure is adjusted in one direction (the head pressure is always increased and the proppant control valve opened only).
[0000]
TABLE 1
Operating Conditions for Various Proppant Concentrations at
a motive flow of 20 BBLS/Min Delivery to the Well Head
Proppant
PP (PSI)
VP (% Open)
Concentration
CV 200
(Lbs/Gal)
Setting/Position
0.25
−15
10%
0.5
−15
19%
0.75
−15
25%
1
−15
30%
1.5
−15
40%
2
15
40%
2.5
15
48%
3
15
56%
3.5
15
67%
4
15
82%
0.5
15
14%
0
15
0%
Working Example 2
Pilot Tests Conducted at 23 GPM of Motive Flow
[0063] Results from the operation of a pilot plant system similar to the one described above and shown in FIG. 3 are given in this Working Example 2. In this system, the concentration of the fracturing fluid was controlled by varying the proppant control valve opening while operating the proppant reservoir at “low” (i.e. between −5 and −27 psi) and “high” (i.e. between 11 and 27 psi) pad pressure conditions. The motive flow was 23 gallons per minute for both pad pressure conditions.
[0064] FIG. 5 illustrates the resulting concentration from pilot plant operations for the “low” pad pressure range. The proppant control valve varied from 8% to 70% open position and proppant concentrations from 0.25 to 3.27 lbs/gal were observed. The proppant concentration did not increase above 3.27 lbs/gal when the proppant control valve open position was increased above 70%. FIG. 6 illustrates the results of varying the proppant control valve position for the “high” pad pressure range. The control valve position varied from 10% to 23% open and concentrations from 0.75 to 4.04 lbs/gal were observed. The minimum achievable concentration for the “high” pad pressure condition was 0.75 lbs/gal.
[0065] The outcome of the “low” and “high” pad pressure pilot tests described in this example illustrates that it is necessary to change both the pad pressure and the proppant control valve position to achieve the full range of proppant loadings required for a fracturing treatment (e.g. 0.25 to 4.0+ lbs/gal).
[0066] While the invention has been describe in detail with reference to exemplary embodiments thereof, it will become apparent to one skilled in the art that various changes and modifications can be made, and equivalents employed, without departing from the scope of the appended claims.
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A system is described that provides for proppant to be blended into a liquefied gas fluid stream with an eductor to produce a proppant slurry which is effectively controlled by the use of a control valve system and associated PLC controller. This system ensures allowing for operation of the system at various static pressures and keeps the proppant completely fluidized throughout the fracing operation.
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CROSS-REFERENCE TO RELATED APPLICATIONS
Not applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to a portable electronic device, and in particular to using a combination of local and remote storage to enhance the storage capability of the portable device. Still more particularly, the invention relates to using a wireless link to permit a portable electronic device, such as a camera, to offload some or all of its data (e.g., pictures).
2. Background Information
Portable electronics are quickly becoming commonplace in many households. Everything from digital cameras, portable personal computers (“PCs”), portable music players (such as the MP3 player that plays MPEG3 (“Motion Picture Experts Group layer 3”) encoded files), and other devices are decreasing in price so that they are now available to the average consumer. Consumers also demand that in addition to these electronic devices being cheap, they must be capable of performing a variety of tasks and functions.
For example, digital cameras are expected to provide images of comparable quality to traditional cameras, and be able to take at least as many as are pictures available in a standard roll of film (e.g., 24, 36). Picture quality in digital cameras is directly related to the resolution of the picture. Resolution of an image is defined by the number of “pixels” (picture elements) in an image. An image with fewer pixels per square inch (i.e., lower resolution) will not look as sharp as an image of comparable size but with more pixels (i.e., higher resolution). For obvious reasons, consumers desire digital pictures having a high resolution, and resolution at least comparable to that provided with conventional cameras and traditional film. However, increasing the resolution of an image (by increasing the number of pixels per square inch) increases the size of the file of the resulting picture. The images are stored locally in the digital camera's memory, which has finite capacity. Thus, the number of pictures the camera can take is limited by the resolution of the images and the camera's internal memory capacity. Other types of portable electronic devices, such as digital audio players (MP3 players) and dictation systems also share this same problem of limited memory capacity.
The electronics industry has attempted to address this problem by introducing “memory cards”. Most portable electronics now have some sort of memory card that can be removed from the device by the user and replaced by another memory card. This requires the user to purchase additional memory cards, which are device specific and generally quite costly. Users are also required to carry extra memory cards anticipating how much memory they will require. Accordingly, a solution to this problem is needed.
BRIEF SUMMARY OF THE PREFERRED EMBODIMENT OF THE INVENTION
The problems noted above are solved in large part by a system and a method for remotely transmitting information from a portable electronic device for storage to a remotely coupled storage device. The portable electronic device preferably communicates with an intermediate electronic device, which in turn communicates with a remote storage device. One preferred embodiment of the portable electronic device is a Bluetooth-enabled camera that communicates to a cellular telephone via a Bluetooth wireless link. The telephone may then use a 3G wireless link and the Internet to communicate with a remote device such as a server, an application service provider (“ASP”) and the like. Providing a communications link from a portable device to a remote device advantageously permits the portable device to offload some or all of its data (e.g., pictures in the embodiment in which the portable device is a camera,) thereby reducing the reliance on the local memory of the portable device.
The camera can be configured for any one of a plurality of operational modes such as real-time upload, automatic upload or manual upload. In real-time mode the portable electronic device generally transfers its data as the data is acquired and as quickly as the wireless connections will allow. Automatic mode senses when the camera's memory is nearly full, or otherwise reaches a predetermined or programmable threshold and initiates a connection, transfers data and then disconnects. Manual mode lets the user decide when to perform the upload by activating a control on the portable electronic device.
In an alternate embodiment, the intermediate electronic device comprises a portable or handheld computer, which includes both Bluetooth and 3G radios. Yet another embodiment is with the intermediate electronic device comprising a portable computer, which also has Bluetooth and 3G radios.
Another embodiment enables rapid access to pictures taken at remote sites. If the home server which communicates to the cellular telephone has preset mail groups, it is possible to broadcast photos directly from a remote site via the method of the preferred embodiment. The ASP, which can also receive data from the portable electronic device, can perform valuable functions on this data, like data base storage and administration services. In yet another embodiment, a PocketPC or portable computer (or any other intermediary device with storage capability) is used instead of the cellular telephone, the camera may off-load to it in any of the previously mentioned modes, and the PC initiates the connection. With this configuration multiple upload destinations can be supported due to the fact that the PC also has its own storage capability and can therefore buffer data.
BRIEF DESCRIPTION OF THE DRAWINGS
For a detailed description of the preferred embodiments of the invention, reference will now be made to the accompanying drawings in which:
FIG. 1 shows a general system with a portable electronic device transferring data between the remote storage device; and
FIG. 2 shows a Bluetooth enabled digital camera transferring images to and from a remote server.
NOTATION AND NOMENCLATURE
Certain terms are used throughout the following description and claims to refer to particular system components. As one skilled in the art will appreciate, computer companies may refer to a component by different names. This document does not intend to distinguish between components that differ in name but not function. In the following discussion and in the claims, the terms “including” and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to . . . ”. Also, the term “couple” or “couples” is intended to mean either an indirect or direct electrical connection. Thus, if a first device couples to a second device, that connection may be through a direct electrical connection, or through an indirect electrical connection via other devices and connections.
The term “Bluetooth” refers to a de-facto open standard for short range digital radio. The specification includes air interface protocols to allow several Bluetooth applications to intercommunicate simultaneously, and to overcome external sources of interference. Bluetooth communications are generally limited to 10 m, or about 30 feet, and data throughput can be as high as 1 megabits per second (“Mbps”).
The term “3G” also called Universal Mobile Telecommunications System (“UMTS”) refers to a communication protocol that provides packet-based transmission capabilities for data and speech at data rates up to 2 Mbps. Via a redundant network of satellites and Internet protocols, 3G provides an “always on” connection where data transfer is readily available throughout much of the world.
The term “ASP” (“Application Service Provider”) refers to an entity that provides individuals or companies access over the Internet to applications and related services.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In accordance with the preferred embodiment of the invention, a portable electronic device permits a user to transfer data to a remote server rather than having to carry additional memory cards anticipating usage requirements. As explained below, the data being transferred can include images, audio, medical measurements, or any other type of digital data. The portable electronic device permits a user to take data that is acquired and or stored in the device and offload the data to an external remotely coupled device to make room for more data in the portable electronic device. For example, pictures in a digital camera can be offloaded to a web-based server through the user's cell phone eliminating the need for the user to carry extra memory cards.
There are numerous embodiments for remotely transferring information for a portable electronic device. FIG. 1 shows a general embodiment of the present invention. Referring to FIG. 1 , system 10 comprises a portable electronic device 75 coupled to an intermediate electronic device 50 , which is also coupled to a remote storage device 25 . Portable electronic device 75 and intermediate electronic device 50 preferably are in the user's possession and control while remote storage device 25 may be a separately controlled device on the Internet or other type of network. The portable electronic device 75 can be any device that may be used to collect data that may be stored digitally, such as a digital camera, a voice recorder, or medical diagnostic equipment to name a few. In the event that device 75 does not have enough capacity to store the data, the user can then transmit it to remote storage 25 via an intermediate electronic device 50 . The remote data storage 25 may be any device that is coupled via the Internet to the intermediate electronic device 50 and that can store data. The remote storage device 25 may comprise a home-based computer, a remote file server, a mass storage device (e.g., hard drive, write able CD-ROM, etc.), or any type of remotely coupled device that includes storage capacity. Preferably, the intermediate electronic device 50 communicates with portable electronic device 75 via a wireless connection such as Bluetooth. Further, intermediate electronic device 50 preferably sends data to and/or receives data from remote storage device 25 via a combination of a wireless link such as “3G” and the Internet. Although the preferred communication methods used in system 10 include Bluetooth and 3G, other methods that allow the user of the portable electronic device 75 to transfer data remotely including combinations of wireless connections and wired connections are also possible.
With the configuration shown in FIG. 1 , portable electronic device 75 can offload its data through intermediate electronic device 50 to remote storage device 25 . The portable electronic device 75 can offload its data during normal operation. If the portable electronic device 75 comprises a digital camera, for example, a user can use the camera to take one or more pictures and then cause the camera to transfer one or more of the pictures through intermediate electronic storage device 50 to remote storage device 25 . This frees up the memory in the camera for taking more pictures without having to swap out memory cards as in conventional systems. As explained below, the intermediate electronics device 50 could comprise a cell phone equipped to receive the pictures from the camera via a Bluetooth communication protocol and then pass on those pictures to the remote storage via 3G and various well-known Internet infrastructure communication mechanisms (routers, switches, etc.)
FIG. 2 shows an embodiment of a system 99 that uses a digital camera for device 75 and a cellular telephone for device 50 . Referring to FIG. 2 , a camera 75 , cell phone 50 , a cellular network 130 , home-based server 100 , an ASP 110 , and the Internet 120 are shown intercoupled by wired and wireless networks. As shown, the digital camera 75 preferably comprises memory 220 , a user interface 210 , a radio frequency transceiver 230 , a display 250 , an image capture device 260 , and a central processing unit (“CPU”) 240 . The transceiver 230 preferably transfers data to and from the cell phone 50 . The transmission protocol may be any suitable protocol such as the well-known Bluetooth standard as noted above. As such the transceiver 230 may be a CX72303 model manufactured by Conexant. The transceiver 230 is coupled to a radio frequency antenna 200 that is able to transmit and receive Bluetooth radio frequency signals. The image capture device 260 serves to capture images in an electronic form. The display 250 preferably is used to view images both before and after they are taken. Additionally, the user can also read status information about the camera from the display 250 , such as the amount of memory remaining, the current mode of operation, the amount of battery life remaining, and any other parameter as desired. The user interface 210 may be used as an interface between the user and the camera 75 allowing the user to select different modes of operation for example. The CPU 240 is used to process data in the camera and can be a Pentium® processor by Intel or any other variant evident to one of ordinary skill in the art. The memory unit 220 preferably is used to store data and may be the removable “memory cards” as noted above, or it may be non-removable type.
The cell phone 50 of the preferred embodiment comprises at least two transceivers 150 and 170 , memory 180 , and a CPU 160 . The cell phone 50 preferably receives pictures from camera 75 via transceiver 170 and forwards the pictures to the cellular network 130 via suitable protocols and/or speeds using transceiver 150 . Transceiver 170 , and its associated antenna 190 provides a wireless communications link between the camera 75 and the cell phone 50 . As such, if transceiver 230 comprises a Bluetooth transceiver, so does transceiver 170 . Preferably, transceiver 150 transfers data to and from the cellular network 130 , which is coupled to the Internet. The cellular network (which comprises cell towers, base stations, etc.) is capable of communicating with the cell phone 50 via any suitable wireless protocol, although 3G is preferred as described below. If cell phone 50 communicates with cell network 130 using 3G, transceiver 150 comprises a 3G transceiver such as TRF6150 provided by Texas Instruments.
The 3G cellular communication protocol is preferred due to its packet-switching transmission capabilities that make it amicable for data transmission. In earlier cellular communications protocols each data transfer would create a circuit that would reserve the path between the two parties for the entire data transfer session (this is known as circuit-switching.) Data networks (like the Internet) on the other hand transfer data much differently using packet-switching. Both circuit-switched and packet-switched networks may break data files into packets if the data exceeds a predetermined size. With packet-switching, routers dynamically determine a path for each individual packet of data, and packets are arbitrarily arranged to use any path available to get to the destination. Unlike circuit-switching, no one data transfer takes up an entire path for an entire transfer session, and data is sent only when data is present. Hence, during pauses in a data transfer, the channel is filled with pieces of other data transfers. Because one transfer does not require an entire circuit, the network can provide what appears to be an “always on” connection, where the user seamlessly can transfer data without having to worry about circuit availability. Because 3G and Bluetooth are packet-switching protocols, they can provide a data path to the remote server 100 that is “always on” where the camera 75 can send and receive images as needed.
In another embodiment, system 99 of FIG. 2 can also use an iPaq pocket PC from Compaq Computer Corporation, or other portable computer as the intermediate electronic device 75 . In this case, the pocket PC or portable computer would comprise a Bluetooth transceiver 170 and a 3G transceiver 150 , and could therefore facilitate a transfer between the portable device 75 and the cellular network 130 that is coupled to the Internet 120 . In this configuration, the iPaq pocket PC or portable computer could use local memory 180 , comprising non-volatile (e.g., hard disk) or volatile (e.g., RAM) to further buffer the data in response to network delays.
Referring again to the preferred embodiment of FIG. 2 , system 99 also includes a home-based server 100 coupled to the Internet 120 . As would be evident to one of ordinary skill in the art, the home-based server 100 comprises a CPU, hard disk, memory, and Internet access such as a modem, network interface card, or a cable modem. Having access to the Internet 120 , the server 100 can transfer data to and from the camera 75 by the array of wired and wireless connections as explained above. Therefore, when a data transfer is desired, a user may cause the camera 75 to transfer data remotely to the storage space of the remote home-based server 100 via the user's cell phone 50 . The cell phone 50 then transmits the pictures through the cellular network 130 (preferably using 3G) to the home-based server 100 for storage thereon. If desired, the camera 75 may also receive data (e.g., pictures) by the reverse process comprising the home-based server 100 transmitting to the cellular network 130 via the Internet 120 , the cellular network 130 then transmitting data to the intermediate electronic device 50 (preferably using 3G), the device 50 transmitting to the portable electronic device 75 (preferably using Bluetooth). The data may then be displayed on display 250 or stored into the camera's local memory 220 .
The embodiment of FIG. 2 may also include an ASP server 110 . As mentioned above, the ASP is an entity which may provide any type of services and functions such as data storage, database management, and broadcasting of images through email to name a just few. Images from the camera 75 may therefore be stored on a home-based server 100 as mentioned above or on an ASP 110 in a similar manner. Once ASP 110 has the data, it may then perform functions on it including broadcasting data to users throughout the Internet 120 .
The user then has many options in reviewing the images that have been remotely stored. As mentioned before, the images can be downloaded from the remote home-based server 100 or the ASP 110 to the camera 75 and be reviewed remotely. Preferably, the home-based server 100 is the user's own computer and as such the user can review images upon returning home. If the images were transferred to the ASP 110 , the user may also access it through the Internet 120 , and download the files from it to the home computer 100 . The ASP 110 may also broadcast these images through an automated email distribution list, or may automatically post them to a web site, which can then be accessed by multiple users.
System 99 of FIG. 2 offers distinct advantages over other systems. Preferably, the portable electronic device 75 is a Bluetooth equipped digital camera and the intermediary electronic device 50 is a 3G cellular telephone. In this arrangement, the home-based server 100 does not have to be Bluetooth enabled in order for the camera to transfer data between them. Also, the camera is not restricted to the proximity (30 ft for Bluetooth) of the home-based server 100 . Instead the 3G cellular telephone only needs to be within sufficient proximity of the camera (approximately 30 ft if Bluetooth is used), and it can then transfer data to the home-based server 100 via the cellular network 130 and the Internet 120 . Likewise with the ASP 110 , Internet connectivity is all that is required to give the ASP access to the Bluetooth equipped digital camera. The user of the digital camera can transmit data to the home-based server 100 or ASP 110 for storage from anywhere the user has access to a 3G network by simply carrying a cellular telephone. The user would no longer be required to purchase costly additional memory because the camera can now dynamically transfer data to a remote storage device in three different modes: real-time, automatic, or manual.
The real-time mode of data transfer between the digital camera and the home-based server 100 is where the camera is permitted to transfer data to the home-based server 100 as quickly as the wireless connections will allow. The camera's memory can therefore act as a buffer and the data transfer process may seem invisible, where the user may not notice whether data is being stored remotely or to local memory.
When operating in automatic mode, the camera senses when the memory is full or nearly full based upon a threshold value. The user can set the threshold to any desired percentage of memory using the user interface 210 . Accordingly, when the camera detects the memory to be full or nearly full, it initiates a connection to the cell phone, transfers data and then disconnects.
In manual mode the user decides when to perform the transfer. The memory capacity remaining may be displayed on display 250 . The user may then arbitrarily decide to transfer data using the user interface 210 . The camera would then fulfill the user's request by making a connection to the cell phone, transferring the data, and then disconnecting.
In another hybrid mode, the camera 75 may be set in manual data transfer mode, but the camera 75 may also initiate an automatic transfer if the buffer is getting full in the event that the user hasn't started a data transfer in time.
Data transfer preferably occurs in one of the three primary modes with the user accessing the user interface 210 to toggle between the three modes. The user interface 210 may be a series of push buttons that the user can use to provide feedback to the camera 75 . A first push button may then be used to toggle between modes, where a user may depresses the button and the camera 75 toggles from say real-time mode to automatic mode for example. If the first push button is used to put the camera 75 in manual mode, then a second push button of the user interface 210 may be used to effectuate the data transfer to the cell phone 50 .
The above discussion is meant to be illustrative of the principles and various embodiments of the present invention. Numerous variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. For example, as noted above, other types of wireless communication protocols other than Bluetooth and 3G may be used to achieve the same result. Also, the use of a digital camera for device 75 and a cellular telephone for device 50 is not meant to be restrictive, and as such other devices may be freely interchanged while still achieving the same effect. Accordingly, although the preferred embodiment uses an image capture device 260 , a display 250 , and a user interface 210 other variations may not necessarily require them. Furthermore, other hybrid data transfer modes exist and the above discussion is not meant to be an exhaustive list of all combinations of data mode transfer. Additionally, the user interface 210 as described herein is shown to be at least one push button, it should be noted that the user interface 210 is a means to convey the user's wishes to the camera 75 , and as such may take on many different forms. It is intended that the following claims be interpreted to embrace all such variations and modifications.
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A system and a method for remotely storing information from portable electronics using a multi-point wireless link. The method and system involves a Bluetooth-enabled camera that communicates to a 3G cellular telephone via a Bluetooth wireless link, the telephone then uses the 3G wireless link to connect to a remote storage device via the Internet. Using this concept, the internal memory of the portable device is used as a buffer memory without needing to be in the vicinity of a computer because the cellular telephone can act as a go between from the portable device to the storage space via the Internet.
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FIELD OF THE INVENTION
The present invention relates to an apparatus and of a method of preserving and protecting tassels. More particularly, the present invention relates to a tassel protector accommodating at least one tassel, particularly when undergoing high wear operations, such as, but not limited to, machine laundry. The invention is concerned with an apparatus to maintain the aesthetic appearance of the tassel by placing and holding a plurality of component strands of decorative tassels into their original conditions during high wear operations.
BACKGROUND OF THE INVENTION
Tassels may accompany all sorts of wear items, such as, but not limited to, garments, for decoration and/or for ceremonial purposes and/or for any other reason. High wear operation, such as laundry and/or storage, for example, may cause tassels to disarrange component strands in an unsightly manner. Heretofore, there is no effective way for users to maintain the appearance of the tassels.
Various boots have been made to overlie tassels to protect lay and order of the component strands. Tassel accessory clips are available, having a pair of overlapped, toothed jaws normally held together by spring action (spring clip design) and operable by the user for receiving the tassel between the spring-pressed jaws. It is also proposed that merely clipping the device onto an unruly tassel and leaving the receiving jaws of the clip under spring pressure over-night will “tame” the unsightly tassel. Another traditional way of straightening the tassels is by winding a rubber band over the rearranged tassels. Such a method is patently weak and ineffective.
In U.S. Pat. No. 6,470,542 to Giannini, there is disclosed, inter alia, “A method and apparatus of preserving and protecting decorative tassels after they have become unsightly from wearing of an item, or to prevent their becoming so, particularly on shoes to which they are attached. Typically, one or more tassels are made up of strands of leather or synthetic leather extending integrally side-by-side from a stem base attached to the shoe. The method and apparatus comprises of arranging or rearranging and encasing the strands in a clamcupule having an upper portion and a lower portion and snap lock mechanism with integrally molded hinge, thereby pressing the strands between the locked clamp and reviving them to or maintaining them in their original aesthetic appearance economically and conveniently”.
Another prior art reference, Japanese Patent Publication JP 2005048340 to Takahashi discloses, inter alia, “to provide a storing tool for a tassel such as an obi buckle, preventing disorder of the tassel at the time of storing or carrying . . . (a) tassel storing tool has a structure of fixing the tassel such as an obi buckle through wrapping the tassel with a sheet having a part to wind and fix. The holding tool opens/closes a zipper part with light force, prevents disorder of the tassel at the time of carrying and crumples at the time of preserving, and is simple in storing.”
Thus, it may be advantageous to have a tassel protector which may be easy to apply to the tassel, and to remove therefrom when not needed. Numerous other advantages and features of the present invention may become readily apparent from the following detailed description of the invention and the embodiment thereof, from the claims and from the accompanying drawings.
SUMMARY OF THE INVENTION
In The following disclosure, aspects thereof are described and illustrated in conjunction with systems and methods which are meant to be exemplary and illustrative, not limiting in scope. The present disclosure may be further directed to a method of utilization and/or usage of such apparatuses.
Accordingly, it is an object of the present invention to provide a tassel preserver specifically designed to retain or reform the tassels to their original, desired positions.
In making the present invention, it is a principal object to provide an apparatus and method whereby the repair shop or the user himself, or herself, can renew or maintain shoe tassels quickly and economically.
It is intended that the present invention will help preserve tassels during arduous use, such as during laundry.
It is also intended that the present invention to allow safe storage of the tassels so that they are not depressed or entangled over the course of time.
An aspect of the present invention generally concerns a tassel protector for protecting lay and arrangement of component strands forming the tassel during arduous use, while the tassel is attached to a garment. The tassel protector comprises a cupule and a core, with the core being removably and at least partially accommodated in the cupule. The cupule comprises an outer face and a generally parallel inner face, with the core comprising a stalk accomodatable in the cupule and extending generally co-axial therewith.
Possibly, the core comprises a knob surrounding the stalk and concentric therewith. The knob comprises an envelope having a first portion adjacent a forward end of the core and a second portion disposed generally rearwardly away therefrom with a rearwardly facing step extending between the first portion and the second portion. When the core is partially accommodated in the cupule, the step faces a lip merging the outer face and the inner face thereof.
Optionally, the knob comprises a slot formed therein. The slot may extend generally longitudinally and may open to the forward end and to the interim face and may additionally open circumferentially between a first bank and a second bank, with each of the first bank and the second bank extending generally radially inwardly away from the envelope.
Further possibly, the core may comprise a generally spiral ramp merging with and extending from the knob to merge with the rearward end while spiraling about the stalk.
Possibly, the ramp may comprise a front ramp face merging with and extending from the second bank, and a rear ramp face extending away from the first bank.
Another aspect of the present invention concerns a method of protecting lay and order of component strands of a tassel, the method comprising the steps of: providing a tassel protector comprising a core at least partially accommodatable by a removable cupule. providing the core with a knob having a slot formed therein, providing the core with a ramp spiraling away from the knob, removing the core from the cupule, inserting the tassel with the garment connected thereto through the slot so that the knob is adjacent the garment, arranging component strands along the ramp. And returning the cupule to at least partially accommodate the core.
In addition to the exemplary aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the figures and by study of the following detailed descriptions.
BRIEF DESCRIPTION OF THE DRAWINGS
Exemplary and/or illustrative embodiments of the present disclosure will be presented herein below in the following figures, by way of example only. The figures are not necessarily to scale, and some features may be exaggerated or minimized and/or roughly shown and/or omitted entirely, to show details of particular components, in a purpose that the present disclosure may become more fully understood from the detailed description and the accompanying schematic figures, wherein:
FIG. 1 shows a schematic perspective view of an exemplary embodiment of a tassel protector according to the present invention in a closed position;
FIG. 2 shows a schematic exploded perspective view of the exemplary embodiment of the tassel protector shown on FIG. 1 ;
FIG. 3 shows a schematic perspective view of an exemplary cupule of the tassel protector shown on FIG. 1 ;
FIG. 4 shows a schematic perspective view of an exemplary core of the tassel protector shown on FIG. 1 ;
FIG. 5 shows a schematic axial cross-section view of the exemplary embodiment of the tassel protector shown on FIG. 1 ; and
FIG. 6 shows a schematic wrapping of an illustrative tassel about the exemplary core of the tassel protector shown on FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
As required, a schematic, exemplary embodiment of the present apparatus and method are disclosed herein, however, it is to be understood that the disclosed embodiment is merely exemplary of the present disclosure, which may be embodied in various and/or alternative forms. Specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present disclosure in virtually any appropriately detailed structure.
Aspects, advantages and/or other features of example embodiments of the invention will become apparent in view of the following detailed description, which discloses various non-limiting embodiments of the invention. In describing example embodiments, specific terminology is employed for the sake of clarity. However, the embodiments are not intended to be limited to this specific terminology. It is to be understood that each specific element includes all technical equivalents that operate in a similar manner to accomplish a similar purpose.
Exemplary embodiments may be adapted for many different purposes and are not intended to be limited to the specific exemplary purposes set forth herein. Other non-limiting examples of such embodiments are compositions that may be used, for example, for structural components. Those skilled in the art would be able to adapt the embodiments of the present disclosure, depending for example, on the intended use of the embodiment.
Attention is presently directed to FIGS. 1 , 2 and 5 . In FIG. 1 , a tassel protect- or 100 is shown with a front 110 at the upper right corner of the illustration, and in FIG. 2 , the front 110 is also shown at the upper right corner of the illustration. The tassel protector 100 comprises a cupule 200 and a core 300 wherein the core 300 is at least partially nested within the generally cup-shaped cupule 200 . When at least partially nesting in the cupule 200 , the core 300 is aligned generally coaxial with the cupule 200 along a longitudinal axis L. The tassel protector 100 extends generally longitudinally away from the front 110 , thereby defining a front-to-rear direction. A pair of diametrically opposed lugs 302 , only one of which is visible, are provided upon external side wall portions of the core 300 and a pair of diametrically opposed substantially L-shaped slots 202 are formed within side wall portions of the cupule 200 such that when the core 300 is inserted into the cupule 200 , and subsequently rotated with respect to the cupule 200 , the lugs 302 will be disposed within the slots 202 so as to effectively lock the core 300 within the cupule 200 .
Attention is additionally drawn to FIG. 3 . The cupule 200 extends generally longitudinally rearwardly away from a lip 210 adjacent the front 110 of the tassel protector 100 . The cupule 200 further comprises oppositely disposed and generally parallel or concentric outer and inner faces 220 , 230 . The outer face 220 and the inner face 230 merge at the lip 210 and extend generally axially away therefrom so as to terminate at an end structure 240 . As can best be seen from FIG. 5 , the end structure 240 comprises oppositely disposed and generally parallel outer and inner end portions 250 , 260 . The outer end 250 merges with the outer face 220 while the inner end 260 merges with the inner face 230 . The outer end 250 and the inner end 260 extend generally transversely to the longitudinal axis L. The outer end 250 defines a rear portion 120 of the tassel protector 100 .
Attention is now drawn to FIG. 4 . The core 300 comprises a stalk 310 which extends in a rearward direction away from a forward end 320 of the core 300 , adjacent the front 110 of the tassel protector 100 , as can be appreciated from FIG. 1 , so as to terminate at a rear end 330 . The stalk 300 is partially surrounded by a generally cylindrical knob 340 . The knob 340 extends generally rearwardly from the forward end 320 of the core 300 , annularly surrounds the stalk 310 , and terminates at a generally rearwardly-facing, radially outwardly extending face 350 as can best be appreciated from FIG. 5 . The knob 340 extends generally radially away from the stalk 310 and coaxially therewith to a radially-outermost envelope or peripheral surface portion 360 . The envelope or peripheral surface portion 360 comprises a slot 365 which extends generally longitudinally between the forward end 320 of the core 300 and the face 350 . The slot 365 also extends substantially in a partially circumferential manner from a first bank 370 to a second bank 380 of the knob 340 . Both the first bank 370 and the second bank 380 extend generally longitudinally from the forward end 320 of the core 300 toward the face 350 . In addition, both the first bank 370 and the second bank 380 effectively extend radially inwardly from the outer envelope or peripheral surface portion 360 to the stalk 310 so as to merge therewith. The first bank 370 meets the envelope 360 at a first corner 390 , while the second bank 380 meets the envelope 360 at a second corner 400 , as can best be appreciated from FIG. 1 .
The envelope 360 also comprises a first portion 410 adjacent the forward end 320 and a second portion 420 adjacent the interim face 350 as can best be appreciated from FIGS. 4 and 5 , and an annular step 430 is defined between the first portion 410 and the second portion 420 . The first bank 370 extends to an inclined transition 440 which then extends to and merges with the radially outwardly extending face 350 . The face 350 extends circumferentially from the transition 440 to a diametrically opposite ramp face 460 of a generally spiral ramp 450 which can be seen in FIG. 2 . The second bank 380 extends to and merges with a front ramp face 470 disposed generally opposite the rear ramp face 460 of the spiral ramp 450 . The ramp spiral 450 spirals about the stalk 310 and joins therewith, extending generally rearwardly so as to terminate with the rear ramp face 460 merging with the rearward end 330 of the core 300 .
Attention is now directed toward FIG. 6 . As a tassel 500 , having generally convergent and/or parallel component strands 510 , needs to be protected during high-intensity use, the tassel 500 is threaded onto the core 300 . The tassel 500 is positioned with a garment end (not shown) of a garment (not shown), to which the tassel 500 may be connected, disposed adjacent the forward end 320 of the core 300 . The tassel 500 is inserted between the first bank 370 and the second bank 380 and is further wrapped about the stalk 310 as it is guided between the rear ramp face 460 and the front ramp face 470 . Once the tassel 500 is wrapped about the core 300 , the cupule 200 is placed over the core 300 , and the tassel 500 wrapped thereabout, so as to protect the individual tassel components 510 and safeguard their disposition, orientation, and neatness. When the core 300 is fully inserted into the cupule 200 , the lip 210 of the cupule 200 is disposed axially adjacent to the step 430 of the core 300 such that the second portion 420 is disposed or accommodated within the cupule 200 and faces the inner face 230 , while the first portion 410 is external of the cupule 200 . The cupule 200 may have a plurality of circumferentially extending or oriented slots 600 interlinking its inner face 230 and its outer face 220 .
In view of the foregoing, it shall be evident that the present invention provides a unique system that protects the disposition, orientation, and neatness of the individual strands of a tassel in a simple, convenient and easy manner. Besides, the present invention is especially useful for easily protecting the tassel against the occurrence of increased wear while facilitating using a garment with its tassels unhindered.
All directional references (that is, upper, lower, upward, downward, left, right, leftward, rightward, top, bottom, above, below, vertical, horizontal, clockwise, and counterclockwise) are only used for identification purposes to aid the reader's understanding of the present disclosure, and may not create limitations, particularly as to the position, orientation, or use of the apparatus and/or method disclosed herein. Joinder references (that is, attached, coupled, connected, hinged, and the like) are to be construed broadly and may include intermediate members between a connection of elements and relative movement between elements. As such, joinder references do not necessarily infer that two elements are directly connected and in fixed relation to each other.
Additionally, all numerical terms, such as, but not limited to, “first”, “second”, “third”, or any other ordinary and/or numerical terms, should also be taken only as identifiers, to assist the reader's understanding of the various embodiments, variations and/or modifications of the present disclosure, and may not create any limitations, particularly as to the order, or preference, of any embodiment, variation and/or modification relative to, or over, another embodiment, variation and/or modification.
Similarly, adjectives such as, but not limited to, “articulated”, “modified”, or similar, should be construed broadly, and only as nominal, and may not create any limitations, not create any limitations, particularly as to the description, operation, or use unless specifically set forth in the claims.
In methodologies directly or indirectly set forth herein, various steps and operations are described in one possible order of operation, but those skilled in the art will recognize that steps and operations may be rearranged, replaced, or eliminated without necessarily departing from the spirit and scope of the present disclosure as set forth in the claims. It is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative only and not limiting. Changes in detail or structure may be made without departing from the spirit of the present disclosure as defined in the appended claims.
While certain exemplary embodiments have been described and shown in the accompanying drawings, it is to be understood that such embodiments are merely illustrative of and not restrictive on the broad present disclosure, and that this present disclosure not be limited to the specific constructions and arrangements shown and described, since various other modifications and/or adaptations may occur to those of ordinary skill in the art. It is to be understood that individual features shown or described for one embodiment may be combined with individual features shown or described for another embodiment. It is to be understood some features are shown or described to illustrate the use of the present disclosure in the context of functional elements and such features may be omitted within the scope of the present disclosure and without departing from the spirit of the present disclosure as defined in the appended claims.
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The present invention relates to an apparatus and of a method of preserving and protecting tassels. More particularly, the present invention relates to a tassel protector accommodating at least one tassel, particularly when undergoing high wear operations, such as, but not limited to, machine laundry. The invention is concerned with an apparatus to maintain the aesthetic appearance of the tassel by placing and holding a plurality of component strands of decorative tassels into their original conditions during high wear operations.
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PRIORITY
The present application is a continuation of U.S. patent application Ser. No. 14/048,863, filed Oct. 8, 2013, which is related to U.S. patent application Ser. No. 14/048,527, which are both incorporated by reference herein in each of its entirety.
TECHNICAL FIELD
The present application relates to the fabrication of trenches buried in substrates of integrated circuits.
BACKGROUND
With the advance in semiconductor technology, there has been increasing demand for higher storage capacity, faster processing systems, and high speed communication systems. To meet these demands, the semiconductor industry continues to scale down dimension of devices, and also increase packing density of devices on an integrated circuit (IC) to accommodate a larger number of devices on an IC. However, this approach of scaling down and closely packing of devices on ICs has drawbacks. The scaling down of devices to smaller dimensions can introduce short channel effects in the devices due to the short channel lengths (about approximately 100 nm or less) of the scaled down devices. In addition, closely spaced devices may suffer from disturbances such as electron leakage, noise coupling, or electrostatic coupling. These drawbacks can degrade the operating characteristics and performance of the devices over time. Thus, it is desirable to improve performance of devices in such high density ICs.
SUMMARY
According to an embodiment, an integrated circuit (IC) includes a substrate, a first device and a second device. Each of the first and second devices include a gate structure. The IC further includes a trench in the substrate self-aligned between the gate structures of the first and second devices. The trench comprises a first filled portion having a dielectric material and a second filled portion having a conductive material. The first filled portion is configured to form a buried trench isolation between the first and second devices.
According to another embodiment, a method for fabricating an integrated circuit (IC) is provided. The method includes defining an area on a substrate between a first and second gate structure, where defining an area comprises patterning the first and second gate structure on a top surface of the substrate. The method further includes forming spacers on the first and second gate structures and forming a self-aligned trench in the defined area. The self-aligned trench comprises a first and second portion with the second portion comprising an open end of the trench. The method further includes filling the first portion with a dielectric material and the second portion with a conductive material.
According to another embodiment, a method for fabricating an IC is provided. The method includes defining an area on a substrate between a first and second partial gate structure, where defining an area comprises patterning the first and second partial gate structure on a top surface of the substrate. The method farther includes forming a self-aligned trench in a substrate between the first and second partial gate structure. The self-aligned trench includes a first portion filled with a dielectric material and a second portion filled with a conductive material.
Further features and advantages of the embodiments, as well as the structure and operation of various embodiments of the patent document, are described in detail below with reference to the accompanying drawings. It is noted that the subject matter is not limited to the specific embodiments described herein. Such embodiments are presented herein for illustrative purposes only. Additional embodiments will be apparent to persons skilled in the relevant art(s) based on the teachings contained herein.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings illustrate the present disclosure and, together with the description, further serve to explain the principles of the disclosure and to enable one skilled in the pertinent art to make and use the disclosure.
FIG. 1 illustrates a cross-sectional view of an IC, according to a first embodiment.
FIG. 2 illustrates a cross-sectional view of an IC, according to a second embodiment.
FIG. 3 illustrates a cross-sectional view of an IC, according to a third embodiment.
FIG. 4 illustrates a cross-sectional view of an IC, according to a fourth embodiment.
FIGS. 5A-5H illustrate cross-sectional views of an IC including a buried trench at select stages of its fabrication process, according to an embodiment.
FIGS. 6A-6L illustrate cross-sectional views of an IC including a self-aligned trench at select stages of its fabrication process, according to an embodiment.
FIGS. 7A-7F illustrate cross-sectional views of an IC including a self-aligned trench at select stages of its fabrication process, according to another embodiment.
FIG. 8 illustrates a cross-sectional view of a partially fabricated IC including a buried trench, according to an embodiment.
FIG. 9 illustrates a cross-sectional view of a partially fabricated IC, according to an embodiment.
FIG. 10 illustrates a flowchart for a method of fabricating an IC, according to a first embodiment.
The present disclosure will now be described with reference to the accompanying drawings. In the drawings, like reference numbers generally indicate identical or similar elements. Additionally, generally, the left-most digit(s) of a reference number identifies the drawing in which the reference number first appears.
DETAILED DESCRIPTION
The following Detailed Description refers to accompanying drawings to illustrate embodiments consistent with the disclosure. The embodiment(s) described, and references in the specification to “one embodiment,” “an embodiment,” “an example embodiment,” etc., indicate that the embodiment(s) described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is understood that it is within the knowledge of one skilled in the art to effect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.
The embodiments described herein are provided for illustrative purposes, and are not limiting. Other embodiments are possible, and modifications may be made to the embodiments within the spirit and scope of the disclosure. Therefore, the Detailed Description is not meant to limit the present disclosure. Rather, the scope of the present disclosure is defined only in accordance with the following claims and their equivalents.
The following Detailed Description of the embodiments will so fully reveal the general nature of the present disclosure that others can, by applying knowledge of those skilled in relevant art(s), readily modify and/or adapt for various applications such exemplary embodiments, without undue experimentation, without departing from the spirit and scope of the disclosure. Therefore, such adaptations and modifications are intended to be within the meaning and plurality of equivalents of the exemplary embodiments based upon the teaching and guidance presented herein. It is to be understood that the phraseology or terminology herein is for the purpose of description and not of limitation, such that the terminology or phraseology of the present specification is to be interpreted by those skilled in relevant art(s) in light of the teachings herein.
Those skilled in the relevant art(s) will recognize that this description may be applicable to many various semiconductor devices, and should not be limited to any particular type of semiconductor devices. Before describing the various embodiments in more detail, further explanation shall be given regarding certain terms that may be used throughout the descriptions.
In embodiments, the term “etch” or “etching” or “etch-back” generally describes a fabrication process of patterning a material, such that at least a portion of the material remains after the etch is completed. For example, generally the process of etching a semiconductor material involves the steps of patterning a masking layer (e.g., photoresist or a hard mask) over the semiconductor material, subsequently removing areas of the semiconductor material that are no longer protected by the mask layer, and optionally removing remaining portions of the mask layer. Generally, the removing step is conducted using an “etchant” that has a “selectivity” that is higher to the semiconductor material than to the mask layer. As such, the areas of semiconductor material protected by the mask would remain after the etch process is complete. However, the above is provided for purposes of illustration, and is not limiting. In another example, etching may also refer to a process that does not use a mask, but still leaves behind at least a portion of the material after the etch process is complete.
The above description serves to distinguish the term “etching” from “removing.” In an embodiment, when etching a material, at least a portion of the material remains behind after the process is completed. In contrast, when removing a material, substantially all of the material is removed in the process. However, in other embodiments, ‘removing’ may incorporate etching.
In an embodiment, the term “selectivity” between two materials is described as the ratio between the etch rates of the two materials under the same etching conditions. For example, an etchant with a selectivity of 3:1 to the semiconductor material over the mask layer means that the etchant removes the semiconductor material at a rate three times faster than that at which it removes the mask layer.
In an embodiment, the terms “deposit” or “dispose” describe the act of applying a layer of material to the substrate. Such terms are meant to describe any possible layer-forming technique including, but not limited to, thermal growth, sputtering, evaporation, chemical vapor deposition, epitaxial growth, atomic layer deposition, electroplating, etc.
In an embodiment, the term “substrate” describes a material onto which subsequent material layers are added. In embodiments, the substrate itself may be patterned and materials added on top of it may also be patterned, or may remain without patterning. Furthermore, “substrate” may be any of a wide array of semiconductor materials such as silicon, germanium, gallium arsenide, indium phosphide, etc. In other embodiments, the substrate may be electrically non-conductive such as a glass or sapphire wafer.
In an embodiment, the term “substantially perpendicular,” in reference to a topographical feature's sidewall, generally describes a sidewall disposed at an angle ranging between about 85 degrees and 90 degrees with respect to the substrate.
In an embodiment, the term “substantially in contact” means the elements or structures in substantial contact can be in physical contact with each other with only a slight separation from each other.
In an embodiment, devices fabricated in and/or on the substrate may be in several regions of the substrate, and these regions may not be mutually exclusive. That is, in some embodiments, portions of one or more regions may overlap.
An Integrated Circuit According to a First Embodiment
FIG. 1 illustrates a cross-sectional view of an IC 100 according to an embodiment. IC 100 may include a substrate 106 , devices 108 , and a trench 130 in an example. Devices 108 as shown in FIG. 1 include only two devices 108 a and 108 b for the sake of simplicity. However, as would be understood by a person of skilled in the art based on the description herein, devices 108 may include any number of devices.
Substrate 106 may be a silicon (Si) substrate implanted with p-type carriers to be a p-type Si substrate, according to an example embodiment. The p-type carriers may be provided by p-type materials, such as, but not limited to, boron. Alternatively, substrate 106 may be a p-type well formed in an n-type Si substrate or well (not shown). N-type Si substrate are formed implanted with n-type carriers that are provided by n-type materials, such as, but not limited to, phosphorus.
In an example, devices 108 a and 108 b may each represent a field-effect transistor (FET) including doped regions 112 and 114 and a gate structure 110 . Devices 108 a and 108 b may be similar in structure and function. Alternatively, devices 108 a and 108 b may be two distinct devices. Doped region 112 may be used as a source/drain region, and similarly, doped region 114 may also be used as a source/drain region. It is understood by a skilled artisan that the source and drain regions of devices 108 a and 108 b may be interchangeable and are named based on voltage values applied to doped regions 112 and 114 . While doped regions 112 and 114 are n-type in this example, they may also be p-type regions when substrate 106 is n-type Si or an n-type well formed in a p-type Si substrate. Further, doped regions 112 and 114 may be formed, for example, using ion implantation to dope substrate 106 with n-type carriers using n-type materials, such as, but not limited to, arsenic. The n-type carrier concentration in doped regions 112 and 114 may be higher than the p-type carrier concentrations of substrate 106 to form heavily doped regions. Generally, doping a material with a comparatively large doping concentration of carriers equal or greater than 10 19 /cm 3 , refers to a doping that is high or heavy.
According to an embodiment, gate structure 110 may be positioned on a top surface 106 a of substrate 106 between doped regions 112 and 114 and in substantial contact with at least a portion of doped region 112 and doped region 114 . Gate structure 110 may include a gate layer 116 and a gate dielectric layer 118 . Gate layer 116 may be disposed over gate dielectric layer 118 and gate dielectric layer 118 may be disposed over substrate 106 . The material used to form gate layer 116 may be, for example, doped polysilicon, metal, or any combination thereof and the material for forming gate dielectric layer 118 may be, for example, thermal oxide, nitride layer, high-k dielectric, or any combination thereof. Gate structure 110 comprises a vertical dimension 111 that is a sum of a vertical dimension 111 a of gate layer 116 and a vertical dimension 111 b of gate dielectric layer 118 .
In an example of this embodiment, applying a first potential to gate structure 110 and a second potential that is lower than the first potential to doped region 112 may cause the n-type carriers below the gate structure 110 to form a channel region (not shown) between doped regions 112 and 114 . When a third potential that is higher than the second potential is applied to doped region 114 , the n-type carriers accumulated in the channel region may allow a current to flow from doped region 114 to doped region 112 . This current is typically referred to as the drain current.
Devices 108 may comprise a depletion region that is depleted of free carriers in a channel region in an example embodiment (not shown). If a positive voltage is applied to doped region 114 , the depletion region can spread in channel region from doped region 114 to doped region 112 . If the depletion region reaches doped region 112 , then “punchthrough” may occur. In such instance, gate structure 110 may no longer be able to control the drain current from doped region 114 to doped region 112 .
In an embodiment, pocket implants 122 may be formed to prevent punchthrough in devices 108 . For example, pocket implants 122 may hinder the depletion region from reaching doped region 112 when the depletion region extends through channel region. Pocket implants 122 may be doped with, for example, boron atoms.
Devices 108 may further include spacers 126 above doped regions 112 and 114 and in substantial contact with respective first and second sides 110 a and 110 b of the gate structure 110 in accordance to an example embodiment. Spacers 126 may be formed using a dielectric material, such as silicon nitride or silicon oxide, though any suitable insulating material may be used.
In accordance with an embodiment, trench 130 may be positioned in substrate 106 between devices 108 a and 108 b . While trench 130 is shown in FIG. 1 to comprise a vertical cross-section having a trapezoidal perimeter, in alternate embodiments trench 130 may comprise vertical cross-sections having any geometric shaped perimeters (e.g. rectangular). Trench 130 may comprise a first portion 130 a , a second portion 130 b , an open end 130 c , and a closed end 130 d . In an example, first portion 130 a may comprise a vertical dimension of about 100 nm-400 nm and second portion 130 b may comprise a vertical dimension of about 100 nm or less. First portion 130 a may be filled with a dielectric material to form a first filled portion 132 of trench 130 and second portion 130 b may be filled with a conductive material to form a second filled portion 134 of trench 130 . The dielectric material filling first portion 130 a may be, for example, oxide or nitride and the conductive material filling second portion 130 b may be, for example, single-crystalline silicon, amorphous silicon (“a-Si”) or polycrystalline silicon (“polySi”), silicon germanium (SiGe), metal silicides, or metal. Thus, first filled portion 132 may form a buried trench isolation within substrate 106 between devices 108 a and 108 b.
In an embodiment, first and second filled portions 132 and 134 may be formed such that top surface 132 a of first filled portion 132 is in substantial contact with bottom surface 134 b of second filled portion 134 , and bottom surface 132 b of first filled portion 132 is in substantial contact with substrate 106 . While top surface 134 a of second filled portion 134 is illustrated in FIG. 1 to be coplanar with top surface 106 a of substrate 106 , it should be understood that top surface 134 a may be raised or lowered with respect to top surface 106 a depending on application of IC 100 by the user. In an embodiment, first filled portion 132 or a part thereof may be in substantial contact with doped region 114 of device 108 a and doped region 112 of device 108 b . In another example, second filled portion 134 or a part thereof may be in substantial contact with doped region 114 of device 108 a and doped region 112 of device 108 b and provide a conductive path between doped region 114 of device 108 a and doped region 112 of device 108 a.
As noted above, electronic processes may be carried out within a region of substrate 106 during operation of devices 108 . These electronic processes of device 108 a may create disturbances such as, but not limited to, current leakage, noise coupling, or electrostatic coupling that may negatively affect the electronic processes and as a result the performance of adjacent device 108 b in instances where devices 108 are closely spaced on substrate 106 . In such instances, first filled portion 132 may provide electrical isolation between the electronic processes of devices 108 a and 108 b within substrate 106 , according to an embodiment.
It should be noted that IC 100 is shown in FIG. 1 as including only one arrangement of trench 130 interposed between adjacent devices 108 a and 108 b for the sake of simplicity. However, as would be understood by a person of skilled in the art based on the description herein, IC 100 may include any number of such arrangements with devices and trenches similar to devices 108 and trench 130 , respectively. In addition, IC 100 may include other devices and functional units that are not shown for the sake of simplicity.
An Integrated Circuit According to a Second Embodiment
FIG. 2 illustrates a cross-sectional view of an IC 200 according to an embodiment. IC 200 is similar to IC 100 as described above. Therefore, only differences between IC 100 and 200 are described herein.
IC 200 comprises a trench 130 that may be self-aligned between adjacent devices 108 a and 108 b according to an embodiment. In an embodiment, the self-aligned placement of trench 130 may be defined by a spacing 236 formed between spacers 126 b and 126 c on top surface 106 a of substrate 106 . In such instance, a lateral dimension of open end 130 c of trench 130 may be equal to spacing 236 . Alternatively, the self-aligned placement of trench 130 may be defined by a spacing formed between gate structures 110 of devices 108 on top surface 106 a (not shown). In an embodiment, the term “self-aligned” refers to formation of trench 130 that may be aligned between two features (e.g. spacers 126 b and 126 c , devices 108 a and 108 b ) of IC 200 without performing any additional steps for the alignment of trench 130 . According to an embodiment, the self-aligned placement of trench 130 may allow devices 108 in IC 200 to be more closely spaced on substrate 106 than those in IC 100 .
A Integrated Circuit According to a Third Embodiment
FIG. 3 illustrates a cross-sectional view of an IC 300 according to an embodiment. IC 300 may include a substrate 106 , devices 308 , and a trench 130 . As IC 300 is similar to IC 100 as described above, only differences between IC 100 and 300 are described herein.
In an embodiment, devices 308 a and 308 b may each comprise a gate structure 310 disposed on top surface 106 a of substrate 106 between doped regions 112 and 114 and in substantial contact with at least a portion of doped region 112 and doped region 114 . Gate structure 310 may include a gate layer 116 and a stack of layers 318 . Stack of layers 318 may comprise a charge storing layer 318 b interposed between a first dielectric layer 318 a and a second dielectric layer 318 c . First dielectric layer 318 a may be disposed over and in substantial contact with top surface 106 a of substrate 106 . Charge storing layer 318 b may be disposed over and in substantial contact with first dielectric layer 318 b . Second dielectric layer 318 c may be disposed over and in substantial contact with charge storing layer 318 b . First and second dielectric layers 318 a and 318 c may each comprise an oxide layer such as, but not limited to silicon dioxide. Alternatively, second dielectric layer 318 e may include a stack of dielectric layers (not shown) comprising, for example, a nitride layer interposed between oxide layers.
Charge storing layer 318 b may include, for example, a charge-trapping nitride layer such as, but not limited to, silicon nitride layer, silicon-rich nitride layer, or any layer that includes, but is not limited to, silicon, oxygen, and nitrogen, in various stoichiometries. Generally, a three layer stack arrangement of such dielectric layers is referred to as an “oxide, nitride, oxide (ONO) stack,” or simply as “ONO layers.”
Alternatively, charge storing layer 318 b may include a polySi layer. Such a polySi charge storing layer 318 b may be used as a floating gate with gate layer 116 used as a control gate in devices 308 , according to an embodiment. Generally, such devices are referred as floating gate devices. It should be understood that the relative thickness of gate layer 116 , charge storing layer 318 b , and first and second dielectric layers 318 a and 318 b presented herein are for illustrative purposes only and not necessarily drawn to scale in FIG. 3 .
According to various embodiments, IC 300 may represent an analog or digital memory device and devices 308 may represent memory cells. In this embodiment, each device of devices 308 may be programmed as follows. Charge storing layer 318 b may be programmed to the charged program level by applying a potential to doped region 114 (functioning as the drain) and a potential to gate structure 310 , while doped region 112 may function as the source (i.e., source of electrons). A potential may also be applied to doped region 112 . The potential applied to gate structure 310 and doped regions 112 and 114 may generate a vertical electric field through charge storing layer 318 b and first and second dielectric layers 318 a and 318 c . At the same time, a lateral electric field along the length of channel from doped region 112 to doped region 114 may be generated. At a given threshold voltage, channel may invert such that electrons are drawn off doped region 112 and caused to accelerate toward doped region 114 . As the electrons move along the length of channel, the electrons gain energy and upon attaining enough energy, the electrons are able to jump over the potential barrier of first dielectric layer 318 a and into charge storing layer 318 b where the electrons may be stored in this layer.
As noted above, electronic processes are carried out within substrate 106 during programming of devices 308 . The electronic processes of one device may cause disturbances that affects the performance of adjacent devices in instances where devices are closely spaced on substrate 106 . For example, during programming of device 308 a , electrons within substrate 106 may migrate from device 308 a to closely spaced adjacent device 308 b and affect the operational performance of device 308 b . In such instances, first filled portion 132 may provide electrical isolation within substrate 106 between devices 308 a and 308 b , according to an embodiment.
A Integrated Circuit According to a Fourth Embodiment
FIG. 4 illustrates a cross-sectional view of an IC 400 according to an embodiment. IC 400 is similar to IC 300 as described above. Therefore, only differences between IC 300 and 400 are described herein.
Trench 130 may be self-aligned between adjacent devices 308 a and 308 b according to an embodiment. The self-aligned placement of trench 130 may be defined by a spacing 236 formed between spacers 126 b and 126 c on top surface 106 a of substrate 106 in an example. In such instance, a lateral dimension of open end 130 c of trench 130 may be equal to a spacing 236 . Alternatively, the self-aligned placement of trench 130 may be defined by a spacing formed between gate structures 310 of devices 308 on top surface 106 a (not shown).
An Example Method for Fabricating an Integrated Circuit According to a First Embodiment
FIGS. 5A-5H illustrate an example fabrication process for forming IC 100 shown in FIG. 1 , according to an embodiment.
FIG. 5A illustrates a cross-sectional view of a partially fabricated IC 100 after formation of a trench etch area 542 on top surface 106 a of substrate 106 , according to an embodiment. Trench etch area 542 may be formed by patterning of a first hard mask layer 538 and a second hard mask layer 540 on substrate 106 , as shown in FIG. 5A . Patterning of first and second hard mask layers 538 and 540 may be performed by standard photolithography and etching processes. First hard mask layer 538 may be disposed on top surface 106 a of substrate 106 , for example, by growing a thermal oxide such as silicon oxide directly from substrate 106 using thermal oxidation. Second hard mask layer 540 may be disposed on first hard mask layer 538 , for example, by depositing a layer of nitride such as silicon nitride using conventional deposition methods such as, but not limited to, chemical vapor deposition (CVD) or atomic layer deposition (ALD). The relative thickness of first and second hard mask layers 538 and 540 formed with respect to each other may be equal or different, according to various embodiments.
FIG. 5B illustrates a cross-sectional view of a partially fabricated IC 100 after formation of trench 130 in trench etch area 542 as described previously with reference to FIG. 5A , according to an embodiment. The patterned first and second hard mask layers 538 and 540 may assist in guiding the formation of trench 130 in trench etch area 542 . Trench 130 may be formed by any conventional etching methods suitable for etching the material of substrate 106 . For example, a dry etch process such as, but not limited to, reactive ion etching (RIE) may be performed to remove the material of substrate 106 for the formation of trench 130 , according to an embodiment. The etching process may be performed to selectively etch the material of substrate 106 in trench etch area 542 without significant etching or removal of first and second hard mask layers 538 and 540 . This selective etching may be done by employing an etchant that has higher selectivity to the material of substrate 106 than the materials of first and second hard mask layers 538 and 540 .
FIGS. 5C-5D illustrate cross-sectional views of partially fabricated IC 100 during formation of first filled portion 132 of trench 130 , according to an embodiment. The formation of first filled portion 132 may comprise a filling process followed by an etch back process. The filling process may be performed by depositing a layer 544 of dielectric material over the partially fabricated IC 100 of FIG. 5B such that at least both first and second portions 130 a and 130 b of trench may be filled, as shown in FIG. 5C . The deposition of layer 544 may be performed using any conventional deposition methods suitable for dielectric materials. For example, dielectric materials such as silicon oxide or silicon nitride may be deposited for layer 544 using a CVD or an ALD process. Following the deposition of layer 544 , an etch-back process may be performed to remove layer 544 from all areas except for first portion 130 a , as shown in FIG. 5D . The formation of first filled portion 132 may be followed by removal of second hard mask layer 540 by using any conventional etching method.
FIGS. 5E-5F illustrate a cross-sectional view of a partially fabricated IC 100 during formation of second filled portion 134 of trench 130 , according to an embodiment. The formation of second filled portion 134 may comprise a filling process followed by an etch-back process. According to an embodiment, the filling process may be performed by depositing a layer 546 of conductive material over the partially fabricated IC 100 of FIG. 5D such that at least second portion 130 b of trench 130 may be filled, as shown in FIG. 5E . The deposition of layer 546 may be performed using any conventional methods suitable for metals or metal suicides such as, but not limited to, sputtering, thermal evaporation or CVD. Alternatively, a-Si or polySi may be deposited for layer 546 using conventional deposition methods. Following the deposition of layer 546 , an etch-back process may be performed to remove layer 546 from all areas except for second portion 130 b . The etch-back process may be performed until top surface 134 a of second filled portion 134 may be coplanar ( FIG. 5F ) or raised higher or lower (not shown) with respect to top surface 106 a of substrate 106 . The formation of second filled portion 134 may be followed by removal of first hard mask layer 538 by using any conventional etching method.
According to another embodiment, the filling process may be performed by growing an epitaxial layer (not shown) from sidewalls 131 a and 131 b of trench 130 in second portion 130 b after the formation of first filled portion 132 . This growth may be performed selectively in second portion 130 b as all other areas on substrate 106 are protected by first hard mask layer 538 or first filled portion 132 . Due to such selective growth to form second filled portion 134 , the etch-back process may be eliminated. The epitaxial layer in second portion 130 b may be doped in-situ or by ion implantation to improve electrical conductivity of second filled portion 134 .
FIG. 5G illustrates a cross-sectional view of a partially fabricated IC 100 after formation of gate structures 110 , according to an embodiment. It should be understood that formation of only two gate structures illustrated herein are for the sake of simplicity and not intended to be limiting. The formation of gate structures 110 may comprise a formation of gate dielectric layer 118 on the entire top surface 106 a of substrate 106 followed by a formation of gate layer 116 on the entire surface of gate dielectric layer 118 . Gate dielectric layer 118 may be formed by growing, for example, silicon oxide directly from substrate 106 using thermal oxidation, assuming substrate 106 to be Si in this embodiment. Alternatively, gate dielectric layer 118 may be formed by depositing silicon oxide, high-k dielectric, other dielectric material, or any combination thereof using a chemical vapor deposition process. Gate layer 116 may be formed by depositing a metal layer, a polySi layer, or any combination thereof using deposition methods such as the ones mentioned above for deposition of metal and polySi. This formation of gate dielectric layer 118 and gate layer 116 may be followed by a patterning and an etching process to define gate structures 110 , as shown in FIG. 5G . The patterning process may be performed by standard photolithography process and the etching process may be performed by dry etch methods such as the ones mentioned above.
FIG. 5H illustrates a cross-sectional view of a fabricated IC 100 (as shown in FIG. 1 ) after formation of doped regions 112 and 114 , pocket implants 122 , and spacers 126 , according to an embodiment. Doped regions 112 and 114 may be formed by an ion implantation method. The ion implantation method may be carried out, for example, using n-type dopants such as arsenic or phosphorous. Prior to or subsequent to doped region formation, pocket implants 122 may be formed. Pocket implants 122 may be implanted using an ion implantation process at an angle into substrate 106 to form the pocket implants at a deeper region below gate structures 110 than doped regions 112 and 114 , as shown in FIG. 5H . Following the formation of pocket implants 122 , and doped regions 112 and 114 , spacers 126 may be formed. Spacers 126 may be a dielectric material such as silicon oxide or silicon nitride. The formation of spacers 126 (as shown in FIG. 5H ) may involve first depositing a dielectric material over the partially formed IC 100 of FIG. 5G or after the formation of doped regions 112 and 114 such that it covers at least the gate structures 110 . The deposition may be carried out by, for example, using a CVD process. This deposition process may be followed by defining spacers 126 as shown in FIG. 5H by patterning the deposited dielectric material for spacers using standard photolithography and etching processes.
It should be understood that the various layers illustrated during the example fabrication process of IC 100 are not necessarily drawn to scale. In addition, the above description is meant to provide a general overview of select steps involved in forming IC 100 shown in FIG. 1 and that, in actual practice, more features and/or fabrication steps may be performed additionally or alternatively to that described herein to form IC 100 , as would be understood by one skilled in the art given the description herein.
An Example Method for Fabricating an Integrated Circuit According to a Second Embodiment
FIGS. 6A-6L illustrate an example fabrication process for forming IC 200 including self-aligned trench shown in FIG. 2 , according to an embodiment.
FIG. 6A illustrates a cross-sectional view of a partially fabricated IC 200 after formation of gate structures 110 and hard mask layers 648 , according to an embodiment. The formation of gate structures 110 and hard mask layers 648 may comprise a formation of gate dielectric layer 118 on the entire top surface 106 a of substrate 106 , followed by a formation of gate layer 116 on the entire surface of gate dielectric layer 118 , and a subsequent deposition of hard mask layer 648 on the entire surface of gate layer 116 . Gate dielectric layer 118 may be formed by growing, for example, silicon oxide directly from substrate 106 using thermal oxidation, assuming substrate 106 to be Si in this embodiment. Alternatively, gate dielectric layer 118 may be formed by depositing silicon oxide, high-k dielectric, other dielectric material, or any combination thereof using a chemical vapor deposition process. Gate layer 116 may be formed by depositing a metal layer, a polySi layer, or any combination thereof using deposition methods such as the ones mentioned above for deposition of metal and polySi. The deposition of hard mask layer 648 may involve depositing a dielectric material such as, but not limited to, silicon oxide or silicon nitride, for example, using a CVD process. This formation of gate dielectric layer 118 , gate layer 116 , hard mask layer 648 may be followed by a patterning and an etching process to define gate structures 110 and hard mask layers 648 , as shown in FIG. 6A . The patterning process may be performed by standard photolithography process and the etching process may be performed by dry etch methods such as the ones mentioned above.
Using a similar method of depositing and patterning, spacers 650 may be formed along sidewalls 110 a and 110 b of gate structures 110 as shown in FIG. 6B . The material for spacers 650 may be dielectric materials such as, but not limited to, silicon oxide or silicon nitride. Hard mask layers 648 and spacers 650 may act as masking layers for gate structures 110 to prevent damage to gate structures 110 during subsequent fabrication processes.
According to an embodiment, gate structures 110 along with spacers 650 may act as a patterned masking layer on substrate 106 to define a trench etch area 642 between spacers adjacent spacers 650 b and 650 c , as shown in FIG. 6B . This trench etch area 642 may be used for a self-aligned formation of trench 130 , as shown in FIG. 6C , according to an embodiment. In an embodiment, the term “self-aligned” refers to formation of trench 130 that may be aligned between two features (e.g. spacers 650 b and 650 c ) of IC 200 without performing any additional steps for the alignment of trench 130 .
The material of substrate 106 from trench etch area 642 may be removed by any conventional etching methods suitable for etching the material of substrate 106 . For example, a dry etch process such as, but not limited to, reactive ion etching (RIE) may be performed to remove the material of substrate 106 for the self-aligned formation of trench 130 , according to an embodiment. The etching process may be performed to selectively etch the material of substrate 106 in trench etch area 642 without etching or removal of hard mask layer 648 and spacers 650 . This selective etching may be done by employing an etchant that has higher selectivity to the material of substrate 106 than the materials of hard mask layer 648 and spacers 650 .
FIGS. 6D-6F illustrate cross-sectional views of a partially fabricated IC 200 during formation of first filled portion 132 of trench 130 , according to an embodiment. This formation may involve an etching process, a subsequent filling process followed by an etch-back process. The etching process involves partial etching of spacers 650 . This partial etching may create a wider spacing between spacers 650 b and 650 c relative to a spacing between sidewalls 131 a and 131 b of trench 130 for better control of the subsequent filling process, as shown in FIG. 6D . The filling process may involve deposition of a layer 654 of dielectric material over the partially fabricated IC 200 of FIG. 6D such that layer 654 at least fills both portions 130 a and 130 b of trench 130 , as shown in FIG. 6E . The dielectric material of layer 654 may be, for example, silicon oxide or silicon nitride. This deposition may be carried out by any conventional deposition process suitable for dielectric materials such as CVD or ALD. It will be appreciated that the preceding step of widening the spacing between spacers 650 b and 650 c may help to reduce the high aspect ratio of the filling area 633 between spacers 650 b and 650 c and trench sidewalls 131 a and 131 b . Reducing the high aspect ratio of filling area 633 may prevent pinch off from occurring between spacers 650 b and 650 c during the deposition process before the entire trench 130 may be filled. The filling process may then be followed by an etch-back process to remove the deposited layer 654 of dielectric material from at least the second portion 130 b of trench 130 , as shown in FIG. 6F . The etch-back process may be carried out by dry etch methods like the ones mentioned above.
In an alternative approach, first filled portion 132 may be formed as illustrated in FIGS. 6G-6I , according to an embodiment. This approach may also be arranged to have wider spacing between spacers 650 b and 650 c relative to spacing between sidewalls 131 a and 131 b of trench 130 for better control of the subsequent filling process. However, in this approach, the spacing between sidewalls 131 a and 131 b of trench 130 may be reduced by a coating process prior to the filling process, according to an embodiment. Thus, the formation of first filled portion 132 in this approach may involve a coating process, a subsequent filling process followed by an etch-back process. The filling process (as shown in FIG. 6H ) and etch-back process (as shown in FIG. 6I ) are similar to the processes described above with reference to FIGS. 6E and 6F . Hence, only the coating process is described. The coating process may involve coating sidewalls 131 a and 131 b of trench 130 with a thin film 656 (“liner 656 ”) of dielectric material such as, but not limited to, silicon oxide or silicon nitride, as shown in FIG. 6G . The material for liner 656 may be the same material that is used in a subsequent filling process for forming first filled portion 132 , according to an embodiment. The coating process may be carried out by a deposition process suitable for depositing thin films such as, but not limited to ALD. Alternately, assuming substrate 106 to be Si in an embodiment, the coating process may be carried out by growing silicon oxide directly from sidewalls 131 a and 131 b using a thermal oxidation process.
FIGS. 6J-6K illustrate cross-sectional views of a partially fabricated IC 200 during formation of second filled portion 134 of trench 130 , according to an embodiment. This formation method is similar to the method described above with reference to FIG. 5E-5F . Following the formation of second filled portion 134 , hard mask layers 648 and spacers 650 may be removed by any conventional etching processes. Subsequently, doped regions 112 and 114 , pocket implants 122 , and spacers 126 may be formed to yield IC 200 as shown in FIG. 6L . The methods of forming doped regions 112 and 114 , pocket implants 122 , and spacer 126 are similar to the ones described above with reference to FIG. 5H . Alternatively, doped regions 112 and 114 and pocket implants 122 may be formed after formation of gate structures 110 as described above with reference to FIG. 6A .
In an alternative embodiment to fabricate IC 200 , the fabrication process may involve forming partial gate structures 710 and hard mask layers 648 (as shown in FIG. 7A ) instead of gate structures 110 and hard mask layers 648 , as shown in FIG. 6A . Partial gate structures 710 may comprise gate dielectric layers 118 and gate layers 716 . Gate layers 716 may be similar to gate layers 116 of gate structures 110 , except for having vertical dimensions smaller than vertical dimensions of gate layers 116 . The partial gate structures 710 with shorter vertical dimensions than gate structures 110 may reduce the high aspect ratio of filling area 633 . Thus, the shorter partial gate structures 710 may further help to control the filling process and avoid pinch off from occurring as discussed above with reference to FIGS. 6D and 6G .
After the formation of partial gate structures 710 and hard mask layers 648 , IC 200 may be fabricated using the method described with reference to FIGS. 6B-6L , except for the removal of hard mask layers 648 , as illustrated in FIG. 7A . Additional processes, such as, but not limited to, the processes illustrated in FIGS. 7B-7F may be performed on IC 200 of FIG. 7A to obtain complete gate structures 770 (as shown in FIG. 7F ). Gate structures 770 may include vertical dimensions equal to vertical dimensions of gate structures 110 , as shown in FIG. 6A .
FIG. 7B illustrates a deposition of a dielectric layer 760 such that it covers all features and exposed regions on substrate 106 , according to an embodiment. The dielectric material of layer 760 may be, for example, silicon oxide or silicon nitride. This deposition may be carried out by any conventional deposition process suitable for dielectric materials such as CVD or ALD. Following the deposition of layer 760 , a chemical mechanical polishing (CMP) process may be performed to at least expose top surfaces 648 a of hard mask layers 648 , as illustrated in FIG. 7C . Subsequently, hard mask layers 648 may be selectively etched without significant etching or removal of underlying gate layers 716 , as shown in FIG. 7D . The selective etching may be done by, for example, an RIE process. The etching process may be followed by a deposition process of layer 765 and a removal process to form additional gate layers 717 of FIG. 7F . Layer 765 may be formed by depositing a metal layer, a polySi layer, or any combination thereof using deposition methods such as the ones mentioned above for deposition of metal and polySi. The removal process following the deposition of layer 765 may be performed by, for example, an etch back process, a CMP process, or a patterning process using standard photolithography and etching process, as described above. Formation of additional gate layers 717 may yield complete gate structures 770 .
It should be understood that the various layers illustrated during the example fabrication process of IC 200 are not necessarily drawn to scale. In addition, the above description is meant to provide a general overview of select steps involved in forming IC 200 shown in FIG. 2 and that, in actual practice, more features and/or fabrication steps may be performed additionally or alternatively to that described herein to form IC 200 , as would be understood by one skilled in the art given the description herein.
An Example Method for Fabricating an Integrated Circuit According to a Third Embodiment
According to an embodiment, IC 300 may be manufactured using a fabrication process similar to the example fabrication process described above for IC 100 with reference to FIGS. 5A-5H . Therefore, only the differences between the example fabrication processes of IC 100 and IC 300 are illustrated in FIG. 8 and discussed below.
Following the formation of second filled portion 134 as described above with reference to FIG. 5F , gate structures 310 (as shown in FIG. 3 ) may be fabricated, according to an embodiment. The formation of gate structures 310 may comprise formation of stack of layers 318 on substrate 106 followed by formation of gate layers 116 on stack of layers 318 . For fabricating stack of layers 318 , a first dielectric layer 318 a may be deposited on entire top surface 106 a of substrate 106 followed by deposition of a charge storing layer 318 b on entire surface of first dielectric layer 318 a , and subsequent deposition of a second dielectric layer 318 c on entire surface of charge storing layer 318 b . First and second dielectric layers 318 a and 318 c and charge storing layer 318 b may be formed using conventional deposition processes such as, but not limited to, CVD and ALD. Alternatively, first dielectric layer 318 a may be formed by growing, for example, silicon oxide directly from substrate 106 using thermal oxidation, assuming substrate 106 to be Si in this embodiment. Alternatively, second dielectric layer 318 c may be formed by growing, for example an oxide layer from a top surface 319 (as shown in FIG. 8 ) of charge storing layer 318 b , assuming charge storing layer 318 b to be a nitride layer, using any conventional oxidation process suitable for nitride materials. Gate layer 116 may be formed by depositing a metal or polySi layer using deposition methods such as the ones mentioned above for deposition of metal and polySi. This formation of stack of layers 318 and gate layer 116 may be followed by a patterning and an etching process to define gate structures 310 , as shown in FIG. 8 . The patterning process may be performed by standard photolithography process and the etching process may be performed by dry etch methods such as the ones mentioned above.
It should be understood that the various layers illustrated during the example fabrication process of IC 300 are not necessarily drawn to scale. In addition, the above description is meant to provide a general overview of select steps involved in forming IC 300 shown in FIG. 3 and that, in actual practice, more features and/or fabrication steps may be performed additionally or alternatively to that described herein to form IC 300 , as would be understood by one skilled in the art given the description herein.
An Example Method for Fabricating an Integrated Circuit According to a Fourth Embodiment
According to an embodiment, IC 400 may be manufactured using a fabrication process similar to the example fabrication process described above for IC 200 with reference to FIGS. 6A-6L . Therefore, only the differences between the example fabrication processes of IC 200 and IC 400 are illustrated in FIG. 9 and discussed below.
In accordance to an embodiment, gate structures 310 and hard mask layers 648 may be fabricated on substrate 106 as shown in FIG. 9 , prior to the formation of spacers 650 as described with reference to FIG. 6B . The method for fabricating gate structures 310 and hard mask layers 648 is similar to the example method described above with reference to FIG. 8 .
Alternatively, IC 400 may be manufactured using a fabrication process similar to the example fabrication process described above for IC 200 with reference to FIGS. 7A-7F . The difference between this example fabrication process of IC 200 and IC 400 may be the formation of stack of layers 318 in IC 400 (as method described above with reference to FIG. 8 ) instead of gate dielectric layer 118 .
It should be understood that the various layers illustrated during the example fabrication process of IC 400 are not necessarily drawn to scale. In addition, the above description is meant to provide a general overview of select steps involved in forming IC 400 shown in FIG. 4 and that, in actual practice, many more features and/or fabrication steps may be performed additionally or alternatively to that described herein to form IC 400 , as would be understood by one skilled in the art given the description herein.
Example Steps for Fabricating an Integrated Circuit According to a First Embodiment
FIG. 10 illustrates a flowchart for a method of fabricating IC 100 shown in FIG. 1 , according to an embodiment. Solely for illustrative purposes, the steps illustrated in FIG. 10 will be described with reference to example fabrication process illustrated in FIGS. 5A-5H .
In step 1010 , trench etch area 542 may be defined by patterning of a first hard mask layer 538 and a second hard mask layer 540 on substrate 106 , as shown in FIG. 5A . Patterning of first and second hard mask layers 538 and 540 may be performed by standard photolithography and etching processes. First hard mask layer 538 may be disposed on top surface 106 a of substrate 106 , for example, by growing a thermal oxide such as silicon oxide directly from substrate 106 using thermal oxidation. Second hard mask layer 540 may be disposed on first hard mask layer 540 , for example, by depositing a layer of nitride such as silicon nitride using, for example, chemical vapor deposition (CVD) or atomic layer deposition (ALD) method.
In step 1020 , trench 130 may be formed in trench etch area 542 , as shown in FIG. 5B , by a dry etch process such as, but not limited to, reactive ion etching (RIE) to remove the material of substrate 106 , according to an embodiment. The etching process may be performed to selectively etch the material of substrate 106 in trench etch area 542 without significant etching or removal of first and second hard mask layers 538 and 540 .
In step 1030 , first portion 130 a of trench 130 may be filled to form first filled portion 132 by depositing a layer 544 of dielectric material such as silicon oxide or silicon nitride followed by an etch-back process to remove layer 544 from all areas except for first portion 130 a , as described above with reference to FIGS. 5C and 5D . The deposition of layer 544 may be performed using, for example, a CVD or an ALD process.
In step 1040 , second portion 130 b of trench 130 may be filled to form second filled portion 134 by depositing a layer 546 of conductive material such as metals or metal silicides followed by an etch-back process to remove layer 546 from all areas except for second portion 130 b , as described above with reference to FIGS. 5E and 5F . The deposition of layer 546 may be performed using, for example, sputtering, thermal evaporation or CVD process. Alternatively, a-Si or polySi may be deposited for layer 546 using conventional deposition methods.
In step 1050 , gate structures 110 may be formed ( FIG. 5G ). The formation of gate structures 110 may involve a deposition of gate dielectric layer 118 on the entire top surface 106 a of substrate 106 followed by a deposition of gate layer 116 on the entire surface of gate dielectric layer 118 . Gate dielectric layer 118 may be formed by depositing silicon oxide, high-k dielectric, other dielectric material, or any combination thereof using a chemical vapor deposition process. Gate layer 116 may be formed by depositing a metal layer, a polySi layer, or any combination thereof using deposition methods such as the ones mentioned above for deposition of metal and polySi. This formation of gate dielectric layer 118 and gate layer 116 may be followed by a patterning and an etching process to define gate structures 110 , as shown in FIG. 5G . The patterning process may be performed by standard photolithography process and the etching process may be performed by dry etch methods such as the ones mentioned above.
In step 1060 , doped regions 112 and 114 , pocket implants 122 , and spacers 126 may be formed ( FIG. 5H ). Doped regions 112 and 114 may be formed by an ion implantation method. Prior to or subsequent to doped region formation, pocket implants 122 may be formed in step 1070 using an ion implantation process at an angle into substrate 106 to form the pocket implants at a deeper region below gate structures 110 than doped regions 112 and 114 , as shown in FIG. 5H . Following the formation of doped regions 112 and 114 and pocket implants 122 , spacers 126 may be formed in step 1080 as described above with reference FIG. 5H .
It should be noted that, although the above method description and related figures describe fabricating only one arrangement of trench 130 interposed between adjacent devices 108 a and 108 b for the sake of simplicity. However, as would be understood by a person of skilled in the art based on the description herein, the above steps may be applied to fabricate any number of such arrangements with devices and trenches similar to devices 108 and trench 130 , respectively.
Those skilled in the relevant art(s) will recognize that the above method 1000 may additionally or alternatively include any of the steps or sub-steps described above with respect to FIGS. 5A-5H , as well as any of their modifications. Further, the above description of the example method 1000 should not be construed to limit the description of IC 100 described above.
CONCLUSION
It is to be appreciated that the Detailed Description section, and not the Summary and Abstract sections (if any), is intended to be used to interpret the claims. The Summary and Abstract sections (if any) may set forth one or more but not all embodiments of the present disclosure as contemplated by the inventor(s), and thus, are not intended to limit the present disclosure or the appended claims in any way.
Embodiments have been described herein with the aid of functional building blocks illustrating the implementation of specified functions and relationships thereof. The boundaries of these functional building blocks have been arbitrarily defined herein for the convenience of the description. Alternate boundaries can be defined as long as the specified functions and relationships (or equivalents thereof are appropriately performed. Also, alternative embodiments may perform functional blocks, steps, operations, methods, etc. using orderings different than those described herein.
The breadth and scope of the present disclosure should not be limited by any of the above-described embodiments, but should be defined only in accordance with the following claims and their equivalents.
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A system and method for providing electrical isolation between closely spaced devices in a high density integrated circuit (IC) are disclosed herein. An integrated circuit (IC) comprising a substrate, a first device, a second device, and a trench in the substrate and a method of fabricating the same are also discussed. The trench is self-aligned between the first and second devices and comprises a first filled portion and a second filled portion. The first fined portion of the trench comprises a dielectric material that forms a buried trench isolation for providing electrical isolation between the first and second devices. The self-aligned placement of the buried trench isolation allows for higher packing density without negatively affecting the operation of closely spaced devices in a high density IC.
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FIELD OF THE INVENTION
[0001] The present invention relates to dispensers generally, and more particularly to a liquid foaming pump with an arrangement for efficiently foaming and dispensing foamed liquid from within a liquid container.
BACKGROUND OF THE INVENTION
[0002] Manual liquid dispensers of various sort have been widely implemented in a variety of applications. One type of liquid dispenser is a manually operated pump that is arranged to prepare a foam from a liquid in a container, and to dispense such foam under manual operation of the pump. In typical arrangements, the dispenser is in the form of a reciprocating pump that is manually operated by force applied against a restorative spring force of an expansion spring within a dispenser device, with the application and removal of the external force being sufficient to generate pressure changes in respective air and liquid chambers in the dispenser to alternately cause foaming/dispensing and intake of air and liquid for liquid foaming in the next pumping cycle.
[0003] A common type of foam dispenser includes those used in daily cosmetic and medicinal applications. Liquid force under pressure into an air-liquid mixing chamber generates a foamable mixture that, when forced through an obstruction, develops a relatively dense dispensable foam. Typically, liquid foaming dispensers of this type comprise a pump housing which contains an air pump chamber and a liquid pump chamber, and a piston that is manually reciprocated in the pump housing. The air piston and the liquid piston are mounted for reciprocating movement in the respective air and liquid chambers, such that movement of the pump against a spring force causes the air piston to move in the air chamber to thereby exert a compression force on the air in the chamber, and likewise the liquid piston in the liquid chamber to exert a compression force on the liquid in the liquid chamber. Valves control the flow of air and liquid from the respective air chamber and liquid chamber into an air-liquid mixing chamber where the air and liquid are mixed and driven through a foaming obstruction to generate the dispensable foam.
[0004] Release of the external downward force to the pump permits the spring to expand under its restorative force, and to thereby return the pumping mechanism to its extended position. This movement of the pump mechanism causes the air piston and the liquid piston to move in their respective air chamber and liquid chamber in a manner which expands the interior volumes of the two chambers. The negative pressures created by such movement draws air into the air chamber and liquid into the liquid chamber. Valve assemblies are typically employed in controlling the flow of air and liquid into the respective air chamber and liquid chamber as their interior volumes are increased by the movement of the pump mechanism.
[0005] While many pumping mechanisms and valve assemblies have been developed in the past to provide the functionality described above, efficiency and manufacturing can be a substantial driver in the marketability of such manual foaming dispensers. Therefore, improvements in the design of the foaming dispenser which even slightly reduces the manufacturing costs can result in significant benefit to the manufacture and sale of liquid foaming dispensers. Additionally, improvements can be made to the mechanism, including the valving arrangements, in order to more efficiently produce a consistent foam, and to limit “bleed” of air and/or liquid out from a designated operational pathway.
[0006] It is therefore an object of the invention to provide a liquid foaming dispenser which improves manufacturability.
[0007] It is another object of the present invention to provide a liquid foaming dispenser which improves operational effectiveness.
SUMMARY OF THE INVENTION
[0008] By means of the present invention, mixing of air and liquid in the preparation of a dispensable foam may be consistently metered through the manual actuation of a foaming pump. The dispenser of the present invention utilizes a double-valve gasket with a configuration which develops secure valve sealing when such sealing is critical to the precise operation of the foaming dispenser. In particular, the combination of air pressures within an air chamber and a deflection movement of the gasket under a first valve operation acts to enhance the sealing engagement of the other valve of the double-valve gasket. Such a utility is accomplished with an inexpensive and easily manufactured gasket, to thereby improve performance and reduce manufacturing costs in comparison to conventional foaming dispensers.
[0009] In one embodiment, the liquid foaming dispenser of the present invention includes a pump body having an air chamber and a liquid chamber, and defining a central axis that defines mutually perpendicular axial and radial directions, and a large piston rod having an air inlet aperture, an air passage, and a hollow interior defining an air-liquid mixing chamber. The dispenser further includes a large piston positioned in the air chamber, and being movable by the large piston rod. A small piston rod including a small piston base and liquid passage coordinates with a small piston positioned in the liquid chamber. The dispenser further includes a large piston gasket forming first and second one-way valves formed by a releasable engagement of first and second gasket flanges against respective sealing surfaces of the large piston rod. The first and second gasket flanges resiliently and radially outwardly bias against the respective sealing surfaces.
[0010] In another embodiment, the liquid foaming dispenser of the present invention includes a pump body having an air chamber and a liquid chamber, and a central axis that defines a mutually perpendicular axial and radial directions. The dispenser has a large piston rod having a hollow interior defining an air-liquid mixing chamber, an air inlet aperture for communicating air from an external environment to the air chamber, and an air passage for communicating air from the air chamber to the air-liquid mixing chamber. A large piston rod is positioned in the air chamber, and is axially movable by the large piston rod. The liquid inlet of the dispenser includes a first valve mechanism for regulating liquid flow into the liquid chamber. A small piston rod includes a second valve mechanism for regulating liquid flow from the liquid chamber to the air-liquid mixing chamber. The dispenser also includes a large piston gasket secured to the large piston rod, and including third and fourth valve mechanisms. The third valve mechanism regulates air flow through the inlet channel and includes a first gasket flange biasing radially outwardly against the large piston rod to establish the releasable engagement forming the third valve mechanism. The fourth valve mechanism regulates air flow through the air passage and includes a second gasket flange biasing radially outwardly against the large piston rod to establish a releasable engagement forming the fourth valve mechanism.
[0011] Another embodiment of the liquid foaming dispenser of the present invention includes a pump body having an air chamber and a liquid chamber, and a central axis that defines mutually perpendicular axial and radial directions. The dispenser also includes a large piston rod having a hollow interior defining an air-liquid mixing chamber, an air inlet aperture for communicating air from an external environment to the air chamber, an air passage for communicating air from the air chamber to the air-liquid mixing chamber, an inner securement channel with an outer stud, and an outer securement channel with an inner stud. A large piston is positioned in the air chamber, and is axially movable by the large piston rod. A small piston rod including a small piston base and a liquid passage is provided with a small piston positioned in the liquid chamber. The dispenser further includes a large piston gasket having a main body portion, an inner circumaxial ring extending radially inwardly from the main body portion, an outer circumaxial ring extending radially outwardly from the main body portion, an inner securement flange extending axially in a first direction from the inner circumaxial ring to engage within the inner securement channel of the large piston rod, and an outer securement flange extending axially in the first direction from the outer circumaxial ring to engage within the outer securement channel of the large piston rod. The large piston gasket includes a first gasket flange extending from the main body portion and resiliently and radially outwardly biasing against the large piston rod, and a second gasket flange extending from the main body portion and resiliently and radially outwardly biasing against the large piston rod. The first gasket flange forms a first valve mechanism for regulating airflow from an external environment through the inlet channel of the large piston gasket, and the second gasket flange forms a second valve mechanism for regulating airflow from the air chamber through the air passage.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a cross-sectional view of a liquid foaming dispenser of the present invention;
[0013] FIG. 2 is an enlarged cross-sectional view of a portion of the liquid foaming dispenser illustrated in FIG. 1 ;
[0014] FIG. 3 is an enlarged cross-sectional view of a portion of the liquid foaming dispenser illustrated in FIG. 1 ;
[0015] FIG. 4 is a cross-sectional view of the liquid foaming dispenser of FIG. 1 during a downstroke portion of the pump cycle;
[0016] FIG. 5 is an enlarged cross-sectional view of a portion of the liquid foaming dispenser illustrated in FIG. 1 ; and
[0017] FIG. 6 is an isolation view of a portion of the liquid foaming dispenser illustrated in
[0018] FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] The objects and advantages enumerated above together with other objects, features, and advances represented by the present invention will now be presented in terms of detailed embodiments described with reference to the attached drawing figures which are intended to be representative of various possible configurations of the invention. Other embodiments and aspects of the invention are recognized as being within the grasp of those having ordinary skill in the art.
[0020] With reference now to the drawing figures, and first to FIG. 1 , a liquid foaming dispenser of the present invention may be operated by connecting the dispenser to a container “A” containing a liquid to be dispensed. In the following description of the invention, the terms “top” and “bottom”, “upper” and “lower”, or similar related terms are used to describe the component parts of the dispenser and their relative positions. Such terms are used only with respect to the drawings, and should not be considered limiting as to the absolute orientation of the component parts in operation.
[0021] As illustrated in FIG. 1 , the dispenser includes a pump body 1 having a large piston 2 , a large piston rod 3 , a small piston 4 and a small piston rod 5 , which components reciprocally move up and down together upon a pumping action imparted upon a dispensing cap 6 . The materials employed in constructing the component parts of the dispenser are those typically used in the industry, such as various plastics.
[0022] At a lower end of pump body 1 , a first valve is established for permitting liquid flow from within container “A” into liquid chamber 14 . In one embodiment, the first valve may be established as a one-way valve through a ball 7 displaceably engaged with a ball seat 7 A. In a “liquid draw” condition of the dispenser, ball 7 may be displaced from sealing engagement with ball seat 7 A, thereby permitting liquid to pass by ball 7 and into liquid chamber 14 . To draw liquid from the deepest portion of the container “A”, a dip tube 90 may convey liquid from within container “A” to inlet 7 B of the dispenser.
[0023] In one embodiment, ball seat 7 A is a shaped portion of inlet adapter sleeve 7 C which engages with lower end of pump body 1 . Ball 7 is displaced from ball seat portion 7 A of inlet adapter sleeve 7 C only under the urging of a negative pressure force within liquid chamber 14 . The illustrated ball and ball seat arrangement, however, is exemplary only, and Applicant anticipates the use of other forms of a one-way valve at the first valve mechanism of the foaming dispenser.
[0024] A ring groove 8 is formed by pump body 1 with a generally U-shaped cross-section to receive spring 9 in a compressed condition between ring groove 8 and supporting ring 10 of small piston rod 5 . In such an arrangement, the restorative force of spring 9 acts against supporting ring 10 to urge small piston rod 5 , and large piston rod 3 , upwardly along a central axis “X” of the foaming dispenser.
[0025] Small piston base 11 is secured to small piston rod 5 within a liquid passage 5 A. Small piston base 11 is configured to receive small piston 4 , wherein small piston 4 may be slidably secured on small piston base 11 to releasably engage in ring groove 12 of small piston base 11 . An enlarged view of the relationship among small piston rod 5 , small piston base 11 , and small piston 4 is illustrated in FIG. 5 . Small piston 4 is operably mounted at pump body 1 and small piston base 11 to form a second valve of the foaming dispenser in regulating liquid transfer from liquid chamber 14 through liquid passage 5 A into air-liquid mixing chamber 15 . The liquid pathway from liquid chamber 14 into air-liquid mixing chamber 15 is opened upon the slidable disengagement of small piston flange 4 A from small piston base 11 at ring groove 12 . Once disengaged, liquid from liquid chamber 14 may pass around flange 4 A of small piston 4 in ring groove 12 , and along groove 13 in small piston base 11 to liquid passage 5 A between small piston base 11 and small piston 5 . Reverse slidable relative movement between small piston 4 and small piston base 11 re-engages flange 4 A of small piston 4 with small piston base 11 at ring groove 12 . The operation of small piston 4 as the second valve mechanism of the foaming dispenser to regulate liquid flow from liquid chamber 14 into air-liquid mixing chamber 15 will be described in greater detail hereinbelow.
[0026] Large piston 2 may be secured to, or integrally formed with large piston rod 3 for reciprocal pumping action with respect to air chamber 17 . Large piston 2 sealingly, but slidingly engages with pump body 1 to reciprocally reduce and expand volume within air chamber 17 . In the illustrated embodiment, large piston 2 is integrally formed with large piston rod 3 , such that reciprocal pumping action of large piston rod 3 simultaneously acts upon large piston 2 in air chamber 17 .
[0027] Large piston rod 3 may be substantially hollow to define at least a portion of air-liquid mixing chamber 15 therewithin. Large piston rod 3 further includes a shoulder 3 A that contacts supporting ring 10 of small piston rod 5 . During the downward pumping portion of the cycle, shoulder 3 A of large piston rod 3 bears against supporting ring 10 of small piston rod 5 to force small piston rod 5 downward into liquid chamber 14 . Upon release of a downwardly directed external force upon large piston rod 3 , spring 9 urges upwardly against supporting ring 10 of piston rod 5 , which, in turn bears against shoulder 3 A of large piston rod 3 to drive large piston rod 3 upwardly to a full extension point. Insert portion 3 B of large piston rod 3 engages with an interior surface 5 B of small piston rod 5 . Typically, a friction fit is established between insert portion 3 B of large piston rod 3 and inner surface 5 B of small piston rod 5 .
[0028] A large piston gasket 50 is secured between large piston rod 3 and small piston rod 5 to establish a double-valve gasket structure to form third and fourth valve mechanisms of the foaming dispenser. Large piston gasket 50 includes an inlet hole 42 which permits inlet air flow to air chamber 17 from the external environment through air inlet aperture 41 in large piston rod 3 . Therefore, on the upstroke of large piston rod 3 , negative pressure is developed in air chamber 17 due to the movement of large piston 2 upwardly to enlarge the sealed volume of air chamber 17 . The negative pressure draws external air through air inlet aperture 41 in large piston rod 3 , and deflects first gasket flange 43 of large piston gasket 50 away from a first sealing surface 47 of large piston rod 3 to open access of the inlet air to inlet hole 42 of large gasket 50 . The releasable engagement of first gasket flange 43 to first sealing surface 47 of large piston rod 3 therefore forms the third valve mechanism of the foaming dispenser.
[0029] On the downstroke of the pumping cycle, movement of large piston 2 into air chamber 17 increases the internal pressure by reducing the sealed volume within air chamber 17 . The increased internal pressure within air chamber 17 eventually becomes sufficient to displace second gasket flange 45 of large piston gasket 50 away from second sealing surface 48 of small piston rod 5 to thereby permit air passage between second gasket flange 45 and second sealing surface 48 to escape from air chamber 17 through air passage 46 into air-liquid mixing chamber 15 . The releasable engagement of second gasket flange 45 of large piston gasket 50 with second sealing surface 48 of small piston rod 5 therefore forms the forth valve mechanism of the foaming dispenser. Air passageway 46 may be formed as an aperture in large piston rod 3 to fluidly communicate between air chamber 17 and air-liquid mixing chamber 15 during the downstroke of the pumping cycle. Air passage 46 may remain open throughout the pumping cycles of the foaming dispenser, with second gasket flange 45 providing a barrier to leakage of material in air-liquid mixing chamber 15 into air chamber 17 when sealed against second sealing surface 48 of small piston rod 5 .
[0030] Large piston gasket 50 may be manufactured from a resiliently pliant yet structurally strong material, such as various plastics. In the illustrated embodiment, as best viewed in FIGS. 2 and 3 , large piston gasket 50 may be formed as a substantially “H”-shaped structure incorporating the above-described third and fourth valve mechanisms as a double-valve defining body. Large piston gasket 50 may be secured to large piston rod 3 at the interface of inner and outer securement flanges 52 , 54 with respective inner and outer securement channels 56 , 58 formed in large piston rod 3 . In the illustrated embodiment, inner securement channel 56 operably receives inner securement flange 52 of large piston gasket 50 at a position radially inwardly of a deflection axis 60 of large piston gasket 50 , while outer securement channel 58 is positioned to operably receive outer securement flange 54 at a position radially outwardly of deflection axis 60 . In the illustrated embodiment, inner and outer securement flanges 52 , 54 are oriented upwardly into respective downwardly-oriented securement channels 56 , 58 in large piston rod 3 .
[0031] Inner securement flange 52 extends orthogonally from inner circumaxial ring 62 , which itself extends circumaxially about central axis “X” of the foaming dispenser, and radially inwardly from main body portion 64 of large piston gasket 50 . Outer stud 56 A of inner retention channel 56 abuts an upper surface of circumaxial ring 62 to further secure large piston gasket 50 in place between large piston rod 3 and small piston rod 5 . Outer securement flange 54 extends orthogonally from outer circumaxial ring 66 , which itself extends radially outwardly from main body portion 64 . Inner stud 58 A abuts an upper surface of outer circumaxial ring to further secure large piston gasket 50 in place between large piston rod 3 and small piston rod 5 . Inner and outer circumaxial rings 62 , 66 may be substantially parallel to one another across a bisecting mid-plane 70 perpendicular to central axis X.
[0032] First and second gasket flanges 43 , 45 extend substantially oppositely from main body portion 64 of large piston gasket 50 , and generally parallel to deflection axis 60 . In a preferred embodiment, first gasket flange 43 is disposed radially outwardly from deflection axis 60 , while second gasket flange 45 is disposed radially inwardly of deflection axis 60 , which deflection axis 60 may be substantially parallel to central axis “X” of the foaming dispenser. Such an arrangement is particularly useful in the illustrated embodiment, wherein first gasket flange 43 biasably engages against first sealing surface 47 of large piston rod 3 along a radially-outwardly directed force vector generated by the biasing force of first gasket flange 43 . Second gasket flange 45 biasably seals against second sealing surface 48 of small piston rod 5 , with the biasing force of second gasket flange 45 also being directed generally radially outwardly against second sealing surface 48 . By positioning first and second gasket flanges 43 , 45 on opposite radial sides of deflection axis 60 , in combination with the directions of biasing force of first and second gasket flanges 43 , 45 against the respective first and second sealing surfaces 47 , 48 in the releasable sealing engagement therebetween, a secure sealing engagement of the non-deflected gasket flange 43 , 45 is facilitated during an operation of one of the third and fourth valve mechanisms. For instance, intake of external air through air inlet aperture 41 of large piston rod 3 is facilitated by negative pressure within air chamber 17 deflecting first gasket flange 43 away from first sealing surface 47 . The negative pressure within air chamber 17 tends to urge second gasket flange 45 against second sealing surface 48 while simultaneously deflecting first gasket flange 43 away from first sealing surface 47 . Such urging enhances the sealing engagement of the fourth valve mechanism, constituted by the sealing contact between second gasket flange 45 and second sealing surface 48 . Such a seal remaining at the fourth valve mechanism during the intake of external air to air chamber 17 prevents simultaneous intake of material from air-liquid mixing cavity 15 into air chamber 17 .
[0033] In like manner to the above description, air discharge from air chamber 17 into air-liquid mixing chamber 15 during the down-stroke portion of the pumping cycle displaces second gasket flange 45 away from second sealing surface 48 , and tends to urge first gasket flange 43 against first sealing surface 47 . Such urging is a result of both positive pressure placed upon an inner radial surface of first gasket flange 43 by the air in the air chamber 17 , as well as a rotational urging caused by the deflection of second gasket flange 45 away from second sealing surface 48 . Such enhanced sealing of first gasket flange 43 to first sealing surface 47 prevents leakage of pressurized air out through air inlet aperture 41 , and instead promotes all air discharge through air passage 46 into air-liquid mixing chamber 15 . The configuration of large piston gasket 50 , with first and second gasket flanges 43 , 45 being operably disposed across deflection axis 60 maximizes the sealing “enhancement” forces generated in the pumping cycle, and described above. It is therefore submitted that the illustrated embodiment of large piston gasket 50 provides a significantly improved and reliable double-valve sealing gasket than that currently available, and assures consistent air flow into and out form air chamber 17 without leakage.
[0034] A reticulated foam base 25 is secured within the hollow chamber defined by large piston rod 3 , wherein reticulated foam base 25 supports a reticulated foam meshwork 26 , which separates inlet 27 from outlet 28 . An isolation view of reticulated foam base 25 is illustrated in FIG. 6 , with inlet 27 disposed at a lower portion of base 25 to permit influx of the foamable air-liquid mixture within air-liquid mixing chamber 15 into a first foaming chamber 25 A. Pumping force of the air-liquid mixture further causes the mixture to pass through foam meshwork 26 along a substantially perpendicular direction to central axis “X” of the foaming dispenser, which can greatly improve the foaming effect of the reticulated foam meshwork. The foamed mixture accordingly passes into second foaming chamber 25 B, and out from base 25 through outlet 28 .
[0035] An upper reticulated foam meshwork 30 and a lower reticulated foam meshwork 31 are disposed between an upper end 3 A of large piston rod 3 and pump cap 6 in the foamed air-liquid mixture outlet pathway to further foam the mixture a second and a third instance. Upper and lower reticulated foam meshworks 30 , 31 are disposed at a spacer 29 within a zone formed by dispensing cap 6 . A fourth foaming instance is achieved at a foaming hole 32 at the entrance to a nozzle outlet 36 of dispensing cap 6 .
[0036] Dispensing cap 6 may be operably mounted to and about large piston rod 3 , wherein downward pressure on dispensing cap 6 is transmitted to large piston rod 3 and, in turn, to small piston rod 5 . Dispensing cap 6 may further be tensibly secured into a center hole of large cap 33 , which is connected to pump body 1 at connection point 37 , and threadably secured to container “A”. In the illustrated embodiment, a transparent shield 34 removably covers large cap 33 and dispensing cap 6 .
[0037] The principles of operation of the present invention are now described with reference to the illustrated embodiment. Other embodiments of the invention, however, are contemplated as being employable in the present invention. Upon application of downward force to dispensing cap 6 , downward motion of dispensing cap 6 is translated to large piston rod 3 , and correspondingly to small piston rod 5 at the interface of shoulder 3 A of large piston rod 3 and supporting ring 10 of small piston rod 5 . The downward movement of large piston rod 3 correspondingly causes large piston 2 to sealingly move downward into air chamber 17 , which decreases the volume of air chamber 17 , and correspondingly increases the internal air pressure therewithin. The increased pressure within air chamber 17 during the compression stroke of large piston 2 forces air within air chamber 17 to force open the fourth valve mechanism, which constitutes a one-way valve formed by second gasket flange 45 of large piston gasket 50 engaged against second sealing surface 48 of small piston rod 5 . The air pressure displaces second gasket flange 45 out from engagement with second sealing surface 48 to permit air to pass through the fourth valve mechanism, and through air passage 46 so as to access air-liquid mixing chamber 15 . During this compression stroke, first gasket flange 43 remains sealingly engaged with first sealing surface 47 of large piston rod 3 so as to prevent air from escaping out from air inlet aperture 41 . As described above, the specific configuration of large piston gasket 50 , including first and second gasket flanges 43 , 45 being respectively disposed radially inwardly and radially outwardly of deflection axis 60 , enhances the sealing engagement of first gasket flange 43 with first sealing surface 47 .
[0038] The translated downward motion of small piston rod 5 overcomes the expansion force of spring 9 to correspondingly move small piston base 11 downwardly into liquid chamber 14 . The mounting of small piston 4 to the inner wall of pump body 1 assumes a frictional fit that is at least slightly greater than the frictional fit of the mounting of small piston 4 to small piston base 11 . Consequently, downward motion of small piston base 11 overcomes the frictional fit between small piston 4 and small piston base 11 to thereby cause relative motion of small piston 4 relative to small piston base 11 while small piston 4 remains stationary with respect to pump body 1 . Such relative motion disengages small piston flange 4 A from sealing engagement with small piston base 11 at ring groove 12 to thereby open the first valve mechanism. Continued downward movement of small piston rod 5 and small piston base 11 eventually results in contact between recess surface 5 C of small piston rod 5 and upper flange 4 B of small piston 4 . Such contact, and continued downward movement of small piston rod 5 overcomes the frictional connection of small piston 4 with pump body 1 , wherein small piston 4 then moves in conjunction with small piston rod 5 , and relative to pump body 1 . As small piston 4 moves downwardly with small piston rod 5 and small piston base 11 , pressure within liquid cavity 14 is increased. Such increased fluid pressure in liquid cavity 14 forces ball 7 against ball seat 7 A, thereby sealingly closing the first valve mechanism of the foaming pump to prevent liquid from escaping from liquid chamber 14 out through inlet 7 B. Furthermore, the increased pressure in liquid chamber 14 drives liquid through the now-opened second valve mechanism by passing around lower flange 4 A of small piston 4 , and into groove 13 and liquid passage 5 A, and ultimately into air-liquid mixing chamber 15 .
[0039] The liquid and air mix within air-liquid mixing cavity 15 , and the mixture is forced under pressure through the reticulated foam meshwork 26 of foam base 25 , as well as upper and lower foam meshworks 30 , 31 before exiting a foaming hole 32 at the nozzle outlet 36 of dispensing cap 6 . The process of the liquid/air mixture passing through such apertured substrates results in the generation of a foam for dispensation out from the nozzle 36 .
[0040] Removal of the downward pressure upon dispensing cap 6 , and translationally to large piston rod 3 and small piston rod 5 , causes small piston rod 5 to move upward upon the urging of the elastic force of spring 9 to correspondingly drive large piston rod 3 upward due to the interaction of small piston rod 5 and large piston rod 3 at supporting rod 10 and shoulder 3 A. As in the initial downward movement of small piston base 11 with respect to small piston 4 , initial upward movement of small piston base 11 overcomes the frictional coupling of small piston 4 to small piston base 11 , and causes small piston base 11 to move upwardly with respect to small piston 4 , which remains stationary with respect to pump body 1 until lower small piston flange 4 A comes into contact with small piston base 11 at ring groove 12 . Continued upward motion of small piston base 11 forces small piston 4 to move in coordination with small piston base 11 , and relative to pump body 1 . The contact between lower flange 4 A of small piston 4 with small piston base 11 at ring groove 12 closes the second valve mechanism, and prevents liquid flow to or from liquid chamber 14 through the second valve mechanism constituted by small piston 4 and small piston base 11 .
[0041] Continued upward motion of small piston rod 5 , small piston base 11 , and small piston 4 increases the volume within liquid chamber 14 to correspondingly decrease the fluid pressure therein. In response to such decreased pressure, ball 7 releases its sealing contact with ball seat 7 A to thereby open the first valve mechanism of the foaming dispenser. The opened first valve mechanism, in combination with the reduced fluid pressure in liquid chamber 14 , draws liquid from within container “A” into liquid chamber 14 through inlet 7 B. Meanwhile, the sealing engagement of the second valve mechanism constituted by lower piston flange 4 A and small piston base 11 prevents flow of liquid from air-liquid mixing chamber 15 into liquid chamber 14 .
[0042] Upward movement of large piston rod 3 , urged by small piston rod 5 , which itself is urged upwardly by spring 9 , causes large piston 2 to move upwardly in air chamber 17 to thereby increase the volume and decrease the pressure within air chamber 17 . The decreased air pressure within air chamber 17 causes first gasket flange 43 to be deflected away from first sealing surface 47 of large piston rod 3 . Such deflection allows inlet air to enter air chamber 17 through air inlet aperture 41 and inlet hole 42 in large piston gasket 50 . As indicated above, the reduced air pressure within air chamber 17 , as well as the rotational movement of large piston gasket 50 generated through the deflection of first gasket flange 43 away from first sealing surface 47 , enhances the sealing contact between second gasket flange 45 and second sealing surface 48 , to thereby securely prevent intrusion of air-liquid mixture from air-liquid mixing chamber 15 into air chamber 17 .
[0043] FIGS. 2 and 3 illustrate the air paths during the compression and expansion strokes of each pump cycle. Air flow is depicted by directional arrows (D, E). FIG. 2 represents the expansion stroke of the pump cycle, wherein air is drawn into the air chamber 17 through air inlet aperture 41 and inlet hole 42 , as depicted by directional arrow “D”. Mixing airflow into air-liquid mixing chamber 15 through air passage 46 is depicted in FIG. 3 by directional arrow “E”. In the compression stroke, large piston rod 3 is driven downwardly, such that second gasket flange 45 is displaced from second sealing surface 48 to allow the air flow along directional arrow “E”. Meanwhile, first gasket flange 43 is pressed against first sealing surface 47 under the positive pressure within air chamber 17 . During the expansion stroke of the pump cycle, large piston rod 3 goes up under the expansive force of spring 9 , resulting in a negative pressure within air chamber 17 to close the second gasket flange 45 against the second sealing surface 48 , and to open first gasket flange 43 by displacing it from first sealing surface 47 .
[0044] When spring 9 urges small piston rod 5 , and correspondingly large piston rod 3 , to the uppermost extension position, the foaming dispenser is then ready for another pumping cycle, with both air chamber 17 and liquid chamber 14 filled with the components necessary for creating a dispensable foam.
[0045] The invention has been described herein in considerable detail in order to comply with the patent statutes, and to provide those skilled in the art with the information needed to apply the novel principles and to construct and use embodiments of the invention as required. However, it is to be understood that the various modifications may be accomplished without departing from the scope of the invention.
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A liquid foaming dispenser includes multiple valve mechanisms for regulating the inflow and mixture of air and liquid to create a foamable preparation. A gasket incorporating a double-valve structure is employed to regulate air inflow from the external environment, and air delivery to the liquid in preparation for foaming. The valve-regulated foaming dispenser securely and precisely blends the air and liquid for consistent foaming results.
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RELATED APPLICATIONS
This application claims priority under 35 USC §119(e) to U.S. Provisional Application Ser. No. 60/088,584, filed Aug. 13, 2008, entitled “Use of a Multifunctional Aluminum Alloy Sandwich Panel for Mine Blast Protection,” and this application also claims priority under 35 USC §120 as a continuation-in-part application of U.S. application Ser. No. 12/447,166, filed Apr. 24, 2009, which is a national stage filing of International Application No. PCT/US2007/022733, filed Oct. 26, 2007, which claims priority from U.S. Provisional Application Ser. No. 60/855,089 filed Oct. 27, 2006, entitled “Manufacture of Lattice Truss Sandwich Structures from Monolithic Materials” and U.S. Provisional Application Ser. No. 60/963,790 filed Aug. 7, 2007, entitled “Manufacture of Lattice Truss Sandwich Structures from Monolithic Materials;” all of the disclosures of which are hereby incorporated by reference herein in their entirety.
GOVERNMENT SUPPORT
Work described herein was supported by Federal Grant No. ONR Grant Nos. N00014-01-1-1051 and N00014-07-1-0764, awarded by Office of Naval Research. The Government has certain rights in the invention.
BACKGROUND OF THE INVENTION
Lightweight sandwich panel structures consisting of low density cores and solid facesheets are widely used in engineering applications. Cellular core structures based upon honeycomb topologies are often used because of their high compressive strength-to-weight ratios and high bending stiffness. These honeycomb structures are close-celled with limited access into the core regions. The cores may be attached to the facesheets or plates by conventional joining methods, such as adhesive bonding, brazing, diffusion bonding and welding. Recently, lattice truss structures have been explored as an alternate cellular core topology. Pyramidal lattice truss structures are usually fabricated from high ductility alloys by folding a perforated metal sheet along the perforations, creating accordion-like structures. Conventional joining methods such as brazing or laser welding are then used to bond the core to solid facesheets, forming sandwich structures. The lattice topology, core relative density, and parent alloy mechanical properties, along with the bond strengths, determine the mode of truss deformation and, therefore, the out-of-plane and in-plane mechanical properties of these structures.
The design of the core-facesheet node interface is of the utmost importance. Ultimately, this dictates the maximum load that can be transferred from the facesheets to the core. Node bond failure has been identified as a failure mode for sandwich structures, especially metallic honeycombs. However, analogous node failure modes have been observed in sandwich panels utilizing tetragonal and pyramidal lattice truss cores during shear loading. Assuming sufficient core-faceplate bond (facesheet-bond) strength and ductility, when sandwich panels are subjected to intense shear or bending loads, the nodes transfer forces from the facesheets to the core members and the topology for a given core relative density dictates the load carrying capacity. When the node-facesheet interfacial strength is compromised by poor joint design or inadequate bonding methods, node bond failure occurs resulting in premature failure of the sandwich panel. Numerous factors determine the robustness of nodes, including joint composition, microstructure, degree of porosity, geometric effects (which control stress concentrations) and the nodes' contact area.
Micromechanical models for the stiffness and strength of pyramidal lattice truss cores, comprising elastic-plastic struts with perfect nodes have been recently developed. These models assumed that the trusses are connected to rigid face sheets and are of sufficiently low aspect ratio that bending effects make a negligible contribution to the stiffness and strength. These micromechanical models also assume the node strength is the same as the parent metal alloy. However, the measured elastic moduli rarely reach the predicted values because of variations in the length of the trusses and small initial departures from straightness introduced by manufacturing processes.
The design of the core-to-facesheet interface in honeycomb sandwich panels is of utmost importance. Ultimately, this dictates the amount of load that can be transferred from the face sheets to the core. This is even more critical for lattice-based cores since they can have a smaller node area than honeycombs of the same core density. Node bond failure has been identified as a key catastrophic failure mode for metallic honeycomb sandwich structures (See Bitzer, 1997). Similar node robustness problems have been observed in lattice-based sandwich structures. When sandwich panels are subjected to shear or bending loads, the nodes transfer forces from the facesheets to the core, assuming adequate node bond strength exists, and the topology for a given core relative density dictates the load carrying capacity. When the core-facesheet interface strength is compromised by poor joint design or weak bonding methods, node failure occurs and catastrophic failure of the sandwich panel results. Although numerous factors (including joint composition, microstructure, degree of porosity, and geometric constraints) determine the robustness of nodes, the node contact area serves as a critical limiting factor in determining the maximum force that can be transmitted across the core-facesheet interface.
Initial efforts to fabricate millimeter scale structures employed investment casting of high fluidity casting alloys such as copper/beryllium (See Wang et al., 2003), aluminum/silicon (See Deshpande et al., 2001, Deshpande and Fleck, 2001, Wallach and Gibson, 2001, Zhou et al., 2004), and silicon brass (See Deshpande and Fleck, 2001). Investment casting begins with the creation of a wax or polymer pattern of the lattice truss sandwich structure. The sandwich structure is attached to a system of liquid metal gates, runners, and risers that are made from a casting wax. The whole assembly is coated with ceramic casting slurry. The pattern is then removed and the empty (negative) pattern filled with liquid metal. After solidification, the ceramic, gates, and runners are removed, leaving behind a lattice based sandwich structure of homogeneous metal. However, the tortuosity of the lattices made it difficult to fabricate high-quality investment-cast structures at the low relative density (2-10%) needed to optimize sandwich panel constructions (See Chiras et al., 2002). In addition, the inherent low quality of as-cast metals resulted in sandwich structures that lacked the robustness required for the most demanding structural applications (See Sugimura, 2004).
The toughness of many wrought engineering alloys is evidenced by development of alternative fabrication approaches based upon perforated metal sheet folding (See Sypeck and Wadley, 2002). These folded truss structures could be bonded to each other or to facesheets by either transient liquid phase (TLP) bonding or micro welding techniques to form lattice-truss sandwich panels. Panels fabricated with tetrahedral (See Sypeck and Wadley, 2002, Rathbun et al., 2004, Lim and Kang, 2006) and pyramidal lattice-truss (See Zok et al., 2004, Queheillalt and Wadley, 2005, McShane et al., 2006, Radford, et al. 2006) topologies have been made by the folding and brazing/TLP bonding method. However, the node bond strength and the topology for a given core relative density may dictate the load-carrying capacity. While these structures are much more robust than their investment cast counterparts, their robustness may be dictated by the quality of the bond between the core and facesheets.
A detailed description of the fabrication approach for making 6061 aluminum alloy lattice truss structures can be found in Multifunctional Periodic Cellular Solids and the Method of Making the Same (PCT/US02/17942, filed Jun. 6, 2002), Method for Manufacture of Periodic Cellular Structure and Resulting Periodic Cellular Structure (PCT/US03/16844, filed May 29, 2003), and Methods for Manufacture of Multilayered Multifunctional Truss Structures and Related Structures therefrom (PCT/US2004/004608, filed Feb. 17, 2004), of which all of the PCT Applications are hereby incorporated by reference herein in their entirety. Briefly, these patents describe a folding process used to bend perforated sheets to create a single or multiple-layered lattice truss structures. The folding is accomplished using a paired punch and die tool or a finger break to fold node rows into the desired truss structure. The lattice truss core is then joined to facesheets via one of the previously mentioned methods to form the lattice truss sandwich structure (i.e. adhesives, welding, brazing, soldering, transient liquid phase sintering, etc.).
SUMMARY OF INVENTION
Provided herein are exemplary methods and systems to manufacture lattice-based sandwich structures from monolithic material. Such methods and systems eliminate the bonding process which is conventionally used to join lattice based truss cores to facesheets to form sandwich structures. This bonded interface is a key mode of failure for sandwich structures which are subjected to shear or bending loads because the nodes transfer forces from the face sheets to the core members while the topology for a given core relative density dictates the load carrying capacity (assuming adequate node-bond strength exists).
An aspect of an embodiment of the present invention comprises a core and related structures that provide very low density, good crush resistance and high in-plane shear resistance. An aspect of the truss structures may include sandwich panel cores and lattice truss topology that may be designed to efficiently support panel bending loads while maintaining an open topology that facilitates multifunctional applications.
Some aspects of various embodiments of the present invention method and system utilize, but are not limited to, novel methodologies to construct sandwich structures without using adhesives, diffusion bonding, brazing, soldering, or resistance/electron/laser welding or coupling to join the cores to the facesheets to form sandwich structures. Facesheet-core interface bond failure (e.g., facesheet-core interface) may be a key failure mode for lattice based sandwich structures. When lattice based sandwich panels are subjected to shear or bending loads, the nodes transfer forces from the face sheets to the core members (assuming adequate node bond strength exists) and the topology (for a given core relative density) dictates the load carrying capacity. However, when the node-facesheet interface strength is compromised, node failure occurs and catastrophic failure of the sandwich panel results.
Some aspects of various embodiments of the present invention method and system may utilize, but are not limited thereto, a two-step manufacturing process. A prismatic structure is extruded forming a 3D structure with a constant cross section along the path of extrusion; thereafter a secondary operation is used to selectively remove material, from the core region, forming a 3D lattice truss sandwich structure. This process can be used for any metal, including (but not limited thereto) steel, aluminum, copper, magnesium, nickel, titanium alloys, etc., and is highly suited for alloys that possess limited ambient temperature ductility.
It should be appreciated that the method of manufacture/fabrication may be altered or adjusted in interest of creating a resultant structure that is ultimately desired or required.
An aspect of an embodiment of the present invention provides a method of creating a monolithic lattice truss or truss-based structure (or related structure as desired or required). The method comprising: providing a monolithic sample; extruding the monolithic sample to selectively remove material along a first path; and machining the monolithic sample to selectively remove material along a second path, wherein the first path and the second path are offset at a desired offset angle to create one or a plurality of truss unit portions. Multiple paths and various types of paths and respective locations and angles may be applied as desired or required to achieve the desired method or structure.
An aspect of an embodiment of the present invention provides a method of creating a monolithic lattice truss structure (or related structure as desired or required). The method comprising: providing a monolithic sample; machining the monolithic sample to selectively remove material along a first path; and machining the monolithic sample to selectively remove material along a second path, wherein the first path and the second path are offset at a desired offset angle to create one or a plurality of truss unit portions. Multiple paths and various types of paths and respective locations and angles may be applied as desired or required to achieve the desired method or structure.
An aspect of an embodiment of the present invention provides a monolithic lattice truss structure (or related structure as desired or required). The structure comprising: one or a plurality of truss unit portions, wherein the truss unit portions have the same metallurgical and microstructural properties.
An aspect of an embodiment of the present invention provides a structure that is manufactured or fabricated in whole or in part and by any one or combination of the manufacturing or fabrication methods discussed herein.
Provided herein are exemplary methods and systems to manufacture bonded corrugation truss based structures from monolithic material. Relatively narrow panels with several cells can manufactured from monolithic materials, but are limited because of the narrow width which is imposed by the limits of current extrusion technology. The Truss-based sandwich structures can be welded using friction stir welding to avoid melting the material and weakening the welds. If other welding methods are used it is desirable to include the use of a vertical side member in the structure to reinforce the welded region. The vertical side members may be thickened.
An aspect of an embodiment of the present invention comprises a core and related structures that provide very low density, good crush resistance and high in-plane shear resistance. An aspect of the truss structures may include sandwich panel cores and that may be designed to efficiently support panel bending loads while maintaining an open topology that facilitates multifunctional applications.
Some aspects of various embodiments of the present invention method and system may utilize, but are not limited thereto, a two-step manufacturing process. Corrugation truss based structures are created by extruding monolithic structures; thereafter the extrusions can be joined using adhesives, diffusion bonding, brazing, soldering, or resistance/electron/laser/friction stir welding or coupling or welded together to form a panel of any width. This process can be used for any metal, including (but not limited thereto) steel, aluminum, copper, magnesium, nickel, titanium alloys, etc., and is highly suited for alloys that possess limited ambient temperature ductility.
It should be appreciated that the method of manufacture/fabrication may be altered or adjusted in interest of creating a resultant structure that is ultimately desired or required.
An aspect of an embodiment of the present invention provides a method of creating a monolithic truss-based structure (or related structure as desired or required). The method comprising: providing monolithic samples; extruding the monolithic samples to selectively remove material along the extruded path; and welding the extrusions together by the process of friction stir welding.
An aspect of an embodiment of the present invention provides a method of creating a monolithic truss structure (or related structure as desired or required). The method comprising: providing a monolithic samples; extruding the monolithic samples to selectively remove material along the extruded path; including a vertical side member in the extruded structures; and joining the extruded structures using adhesives, diffusion bonding, brazing, soldering, or resistance/electron/laser/friction stir welding or coupling or welded together to form a panel of any width such that vertical side members are located at the interfaces of the joined extruded structures.
An aspect of an embodiment of the present invention provides a method of creating a monolithic truss structure (or related structure as desired or required). The method comprising: providing a monolithic samples; extruding the monolithic samples to selectively remove material along the extruded path such that the extrusion nodes have a curved or smoothed triple point interface with the facesheet; including a vertical side member in the extruded structures; and joining the extruded structures using adhesives, diffusion bonding, brazing, soldering, or resistance/electron/laser/friction stir welding or coupling or welded together to form a panel of any width; such that vertical side members are located at the interfaces of the joined extruded structures.
An aspect of an embodiment of the present invention provides a method of creating a monolithic lattice truss structure (or related structure as desired or required). The method comprising: providing a monolithic samples; extruding the monolithic samples to selectively remove material along the extruded path such that the extrusion nodes have a curved or smoothed triple point interface with the facesheet; including a vertical side member in the extruded structures; and joining the extruded structures using adhesives, diffusion bonding, brazing, soldering, or resistance/electron/laser/friction stir welding or coupling or welded together to form a panel of any width such that vertical side members are located at the interfaces of the joined extruded structures; repeating the process to manufacture several such panels; and the panels are stacked upon each other and bonded by various metallurgical or adhesive methods to create a multilayered structure.
An aspect of an embodiment of the present invention provides a method of creating a monolithic lattice truss structure (or related structure as desired or required). The method comprising: providing a monolithic samples; extruding the monolithic samples to selectively remove material along the extruded path such that the extrusion nodes have a curved or smoothed triple point interface with the facesheet; including a vertical side member in the extruded structures; and joining the extruded structures using adhesives, diffusion bonding, brazing, soldering, or resistance/electron/laser/friction stir welding or coupling or welded together to form a panel of any width such that vertical side members are located at the interfaces of the joined extruded structures; repeating the process to manufacture several such panels; and the panels either in single or multilayer form are edge supported (e.g., clamped).
An aspect of an embodiment provides a method of creating bonded corrugation truss based structures. The method comprising: providing a monolithic sample; extruding the monolithic sample to selectively remove material, which yields a first corrugation panel; extruding another the monolithic sample to selectively remove material, which yields a second corrugation panel; and laterally coupling the first and second corrugation panels in communication with one another to form a single continuous plurality panel.
An aspect of an embodiment comprises a panel, the panel comprising: a first monolithic corrugated panel and a second monolithic corrugated panel that are laterally coupled in communication with one another to form a single continuous plurality panel.
These and other objects, along with advantages and features of the invention disclosed herein, will be made more apparent from the description, drawings and claims that follow.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated into and form a part of the instant specification, illustrate several aspects and embodiments of the present invention and, together with the description herein, and serve to explain the principles of the invention. The drawings are provided only for the purpose of illustrating select embodiments of the invention and are not to be construed as limiting the invention.
FIGS. 1 (A)-(C) provide schematic illustrations of three stages of the manufacturing method utilizing two arrays of channels EDM cut into a monolithic block of metal forming a pyramidal lattice truss sandwich structure.
FIGS. 2 (A)-(B) provide schematic illustrations of two of the stages of the manufacturing method utilizing a single array of channels EDM cut into an extruded prismatic sandwich structure forming a pyramidal lattice truss sandwich structure.
FIG. 3 provides a photographic depiction of a pyramidal lattice sandwich structure which was EDM cut from a 6061 aluminum alloy extrusion.
FIGS. 4 (A)-(B) provide schematic illustrations of two of the stages of the manufacturing method of a double-layer pyramidal lattice sandwich structure with aligned nodes between adjacent layers and a double array of channels EDM cut into an extruded double-layer prismatic sandwich structure.
FIG. 5 provides a schematic illustration of the extrusion process used to produce 6061 aluminum corrugated sandwich structures.
FIGS. 6 (A)-(B) provide schematic illustrations of the regions in the corrugated core that are removed by electro discharge machining to create a pyramidal lattice core sandwich panel structure.
FIG. 7 provides a photographic depiction of an extruded/electro discharge machined pyramidal lattice sandwich structure with a core relative density of 6.2%.
FIG. 8(A) graphically illustrates the compressive stress verses strain response. Predictions of the stress for inelastic buckling and plastic yielding of the trusses are also shown. FIGS. 8 (B)-(G) provide photographic depictions of the lattice deformation at strain levels (ε) of 0, 5, 10, 15, 20 and 25%, respectively.
FIG. 9(A) graphically illustrates the shear stress verses shear strain response. Predictions of the stress for inelastic buckling and plastic yielding of the trusses are also shown. FIGS. 9 (B)-(D) provide photographic depictions of the lattice deformation at strain levels (γ) of 0, 6 and 12%, respectively.
FIGS. 10 (A)-(B) graphically illustrates the normalized (a) compression and (b) shear stiffness measurements, respectively, versus strain.
FIG. 11 provides a schematic illustration of one embodiment of a sandwich structure of the p-JBD system interacting with a jet.
FIGS. 12 (A)-(C) provide schematic illustrations of an embodiment of a sandwich structure demonstrating blast or explosion mitigation in response to an explosion. FIGS. 12 (A)-(C) provide the impulse loading stage, core crushing stage, and panel bending stage, respectively.
FIGS. 13 (A)-(D) provide schematic illustrations of an embodiment of a sandwich structure 1201 demonstrating projectile arresting capabilities in response to a projectile, which provides various rupture and fracture details.
FIGS. 14 (A)-(C) provides a schematic illustration the typical extrusion process used to cut a monolithic block of metal forming a pyramidal lattice truss sandwich structure, a cross section of a pyramidal lattice truss sandwich structure, and three nodes with a curved or smooth triple point interface with the facesheet.
FIGS. 15 (A)-(B) provide a schematic illustration of the friction stir welding technique used to join extruded prismatic sandwich structures to form a panel and a cross section of the panel.
FIG. 16 (A)-(B) provides a photographic depiction extrusion of extruded and friction stir welded corrugated core 6061-T6 aluminum sandwich panel, and a close-up of the panel cross section highlighting the weld line and the dimensions of the core, the facesheets, and the vertical side member.
FIG. 17(A) graphs hardness of the corrugation plurality panels in MPa as a function of distance from the weld.
FIG. 17(B) graphs the true stress in MPa as a function of true strain for both the parental material.
FIGS. 18 (A)-(B) provide a schematic illustration and a photograph depiction of the “Black Widow” blast testing rig used to evaluate the mine blast resistance of the corrugation panels.
FIGS. 18(C)-18(H) provide a schematic illustration depicting the process for constructing the “wet sand” charge, which is used for simulating mine blasts.
FIGS. 19 (A)-(B) provide a graph and a chart of the back facesheet deflection of the corrugation panel and a mass equivalent solid panel at different standoff distances using the “Black Widow” blast testing rig.
FIG. 20 (A)-(B) provides photographs of corrugation plurality panels ( FIG. 7(A) ) and mass equivalent solid panels ( FIG. 20(B) ) subjected to the black widow blast testing rig at different standoff distances.
FIGS. 21 (A)-(B) provide photographs of a corrugation plurality subjected to the black widow blast testing rig at a 25 cm standoff. Additionally, FIG. 21(A) provides an enlarged partial view highlighting tearing along the region where the corrugation plurality panel is clamped to the rig. FIG. 21(B) shows partial close-up images of the cross section of the corrugation plurality panel.
FIGS. 22 (A)-(B) provide photographs of a corrugation plurality subjected to the black widow blast testing rig at a 22 cm standoff. Additionally, FIG. 22(A) provides an enlarged partial view highlighting tearing along the region where the corrugation plurality panel is clamped to the rig. FIG. 22(B) shows partial close-up images of the cross section of the corrugation plurality panel.
FIGS. 23 (A)-(B) provide photographs of a corrugation plurality subjected to the black widow blast testing rig at a 19 cm standoff. Additionally, FIG. 23(A) provides an enlarged partial view highlighting tearing along the region where the corrugation plurality panel is clamped to the rig. FIG. 23(B) shows partial close-up images of the cross section of the corrugation plurality panel.
FIGS. 24 (A)-(B) provide photographs of a corrugation plurality subjected to the black widow blast testing rig at a 15 cm standoff. Additionally, FIG. 24(A) highlights tearing along the region where the corrugation plurality panel is clamped to the rig. FIG. 24(B) shows partial close-up images of the cross section of the corrugation plurality panel.
FIG. 25 provides a summary table of the results of the corrugation plurality panels subjected to the black widow blast testing rig.
DETAILED DESCRIPTION OF THE INVENTION
As described earlier, a variety of lattice topologies can be fabricated from ductile metals using current fabrication methods that rely on cutting, stamping and/or bending processes to form the desired lattice core, which is then subsequently bonded to facesheet by a variety of methods including, but not limited to, adhesives, diffusion bonding, brazing, soldering or resistance/electron/laser welding, coupling, etc. The design of the core-to-facesheet interface is of utmost importance. Ultimately, this dictates the amount of load that can be transferred from the facesheets to the core, and, ultimately, supported by the truss assembly.
Provided herein, an aspect of an embodiment provides methods and systems that result in sandwich structures with highly robust nodes that can be manufactured from any metal, including, but not limited to steel, aluminum, copper, magnesium, nickel, titanium alloy, etc. These methods are well-suited for alloys that possess limited ambient temperature formability.
The following are exemplary methods and systems of various embodiments of the present invention that can be used to fabricate lattice truss sandwich structures (or any structure as desired/required) from any metal, thus greatly expanding the realm of metals that can be fabricated into cellular structures, as the aforementioned methods (adhesives, diffusion bonding, brazing, soldering or resistance/electron/laser welding, etc.) could only have been fabricated from alloys. In addition, since there is no metallurgical or microstructural discontinuity at the truss-facesheet (truss-faceplate) interface region, the likelihood of corrosion is greatly reduced.
In an exemplary and non-limiting embodiment of an aspect of the present invention, a pyramidal lattice sandwich structure is formed from a solid monolithic sample 1 , such as a piece of metal, but not limited thereto. The initial monolithic sample 1 can be sheet, plate, ingot, billet, powder compact, or slurry, or the like, form depending on the size of the final sandwich structure or any desired/required structure. The following is a description for the manufacture of a pyramidal lattice. It should also be appreciated, however, that tetrahedral, Kagome, cone, frustum, or other lattice-based truss structures may be manufactured via this method as desired or required. FIG. 1(A) shows an example of a solid, monolithic sample 1 . FIG. 1(B) shows an example of a triangulated pattern machined in the y-direction. This pattern can be machined via electro discharge machining, drilling including laser drilling and other ablative removal techniques in which material is melted or evaporated, cut, water jet cutting, chemical dissolution methods or any other suitable operation. At this point, the structure has the form of a 2D prismatic sandwich structure 2 with facesheets 11 and a consistent cross-section along the y-axis. FIG. 1(C) shows an example of a triangulated pattern machined in the x-direction. Again, this pattern can be machined via electro discharge machining, cutting or any other suitable operation. The result of the combination of these two processes is a 3D lattice truss sandwich structure 3 with facesheets 11 enclosing truss units 12 , forming nodes 13 where a truss units 12 interfaces with a facesheet 11 . The truss units 12 comprise of a plurality of legs or ligaments 14 . The legs may have a variety of shapes such as straight or curved and may have a variety of cross-sections. The plurality of truss units 12 form an array of truss units. While the y-direction path and the x-direction path are shown as substantially straight, it should be appreciate that the paths may be curved or shaped as desired or required. For instance, the array of truss units and panels (or any related components of the resultant structure) may be fabricated so that the truss units and panels (or any related components) may be contoured or shaped as desired or required. Moreover, while the various paths (x, y, and z) as illustrated appear to be substantially orthogonal or perpendicular respectively with one another, it should be appreciated that any respective angles may be implemented as desired or required for the desired or required fabrication process or resultant truss and/or panel structure. In an embodiment, the monolithic sample 1 may comprise at least one select material as desired or required. In an embodiment, the select material may comprise, for example but not limited thereto, ceramic, polymer, metal, metal alloy, and/or any combination of composites thereof (or any material(s) as desired or required. It should be appreciated that the monolithic sample may be machined along a plurality of paths, such as two or more as desired or required. It should be appreciated that the monolithic sample may be extruded along a plurality of paths, such as two or more as desired or required. The area that the faceplate or facesheet and truss units intersect form an interface region. In an embodiment, the interface region has the same metallurgical and microstructural properties. In an embodiment, the truss units have nodes wherein the nodes have the same metallurgical and microstructural properties as the truss unit. In an embodiment, the extruding or machining or both the extruding and machining create the truss units of varying relative density.
In an exemplary and non-limiting embodiment of an aspect of the present invention, a pyramidal lattice sandwich structure is formed from an extruded prismatic structure. The extruded prismatic structure can take on a variety of shapes, dependent only upon the desired topology of the final sandwich structure or any desired/required structure. Again, the following is a description for the manufacture of a pyramidal lattice. It is envisioned, however, that tetrahedral, Kagome, cone, frustum, or other lattice-based truss structures may be manufactured via this method. FIG. 2(A) shows an example of an extruded triangulated pattern 21 (extruded direction is the y-direction), with facesheets 11 . FIG. 2(B) shows an example of a triangulated pattern machined in the x-direction of the extruded topology, the combination of these two steps producing a pyramidal lattice sandwich structure. Again, this pattern can be machined via electro discharge machining, cutting, drilling including laser drilling and other ablative removal techniques in which material is melted or evaporated, water jet cutting, chemical dissolution methods or any other suitable operation resulting in the 3D lattice truss sandwich structure 22 with facesheets 11 enclosing truss units 12 , forming nodes 13 where truss legs or ligaments 14 interface with a facesheet 11 . The truss units 12 comprise of a plurality of legs or ligaments 14 . The legs may have a variety of shapes such as straight or curved and may have a variety of cross-sections. The plurality of truss units 12 form an array of truss units. While the y-direction path and the x-direction path are shown as substantially straight, it should be appreciate that the paths may be curved or shaped as desired or required. For instance, the array of truss units and panels (or any related components of the resultant structure) may be fabricated so that the truss units and panels (or any related components) may be contoured or shaped as desired or required. Moreover, while the various paths (x, y, and z) as illustrated appear to be substantially orthogonal or perpendicular respectively with one another, it should be appreciated that any respective angles may be implemented as desired or required for the desired or required fabrication process or resultant truss and/or panel structure. In an embodiment, the monolithic sample 1 may comprise at least one select material as desired or required. In an embodiment, the select material may comprise, for example, but not limited thereto, ceramic, polymer, metal, metal alloy, and/or any combination of composites thereof (or any material(s) as desired or required. It should be appreciated that the monolithic sample may be machined along a plurality of paths, such as two or more as desired or required. It should be appreciated that the monolithic sample may be extruded along a plurality of paths, such as two or more as desired or required. The area that the facesheet or faceplate and truss units intersect form an interface region. In an embodiment, the interface region has the same metallurgical and microstructural properties. In an embodiment, the truss units have nodes wherein the nodes have the same metallurgical and microstructural properties as the truss unit. In an embodiment, the extruding or machining or both the extruding and machining create the truss units of varying relative density.
FIG. 3 provides a photographic depiction of a pyramidal lattice sandwich structure 23 which was EDM cut from a 6061 aluminum alloy extrusion with facesheets 11 enclosing truss units 12 , forming nodes 13 where truss legs or ligaments 14 interfaces with a facesheet 11 .
In an exemplary and non-limiting embodiment of an aspect of the present invention, these manufacturing techniques may be used to form multi-layered sandwich panels. Again, the following is a description for the manufacture of a double-layer pyramidal lattice, however, it is envisioned that tetrahedral, Kagome, cone, frustum, or other lattice-based truss structures of any number of layers may be manufactured via this method. FIG. 4(A) shows an example of a double-layer extruded triangular pattern 31 sandwich structure (extruded direction is the y-direction). FIG. 4(B) shows an example of a triangulated pattern machined in the x-direction of the extruded topology, forming a pyramidal lattice sandwich structure. Again, this pattern can be machined via electro discharge machining, drilling including laser drilling, cutting, removing and other ablative removal techniques in which material is melted or evaporated, water jet cutting, chemical dissolution methods or any other suitable operation. The combination of these two steps produces a multi-layered 3D lattice truss sandwich structure 32 , with facesheets 11 enclosing truss units 12 , forming nodes 13 where truss legs or ligaments 14 interface with a facesheet 11 . It is noted that the alignment of nodes 32 between adjacent layers is not a prerequisite. As with this embodiment or any embodiments discussed herein, each individual layer may be aligned or offset any amount from adjacent layers, yielding the desired properties for the structure as a whole and the layers individually. Similarly, the truss units may have any number of legs or ligaments according to the fabrication approach. The truss units 12 comprise of a plurality of legs or ligaments 14 . The legs may have a variety of shapes such as straight or curved and may have a variety of cross-sections. The plurality of truss units 12 form an array of truss units. While the y-direction path and the x-direction path are shown as substantially straight, it should be appreciate that the paths may be curved or shaped as desired or required. Moreover, while the various paths (x, y, and z) as illustrated appear to be substantially orthogonal or perpendicular respectively with one another, it should be appreciated that any respective angles may be implemented as desired or required for the desired or required fabrication process or resultant truss and/or panel structure. For instance, the array of truss units and panels (or any related components of the resultant structure) may be fabricated so that the truss units and panels (or any related components) may be contoured or shaped as desired or required. In an embodiment, the monolithic sample 1 may comprise at least one select material as desire or required. In an embodiment, the select material may comprise, for example but not limited thereto, ceramic, polymer, metal, metal alloy, and/or any combination of composites thereof (or any material(s) as desired or required. It should be appreciated that the monolithic sample may be machined along a plurality of paths, such as two or more as desired or required. It should be appreciated that the monolithic sample may be extruded along a plurality of paths, such as two or more as desired or required. The area that the faceplate/facesheet and truss units intersect form an interface region. In an embodiment, the interface region has the same metallurgical and microstructural properties. In an embodiment, the truss units have nodes wherein the nodes have the same metallurgical and microstructural properties as the truss unit. In an embodiment, the extruding or machining or both the extruding and machining create the truss units of varying relative density.
Aspects of various embodiments of the present invention provide, but are not limited to, a novel method and system to manufacture lattice-based truss sandwich structures or any desired/required structures that provides enhanced truss-facesheet interface strength by avoiding poor joint design or bonding procedures, which can cause the catastrophic failure of sandwich panels. Although numerous factors determine the robustness of joined nodes (joint composition, microstructure, degree of porosity, geometric constraints, etc.) this new method results in sandwich structures with highly robust nodes that have the equivalent metallurgical, for instance strength, ductility, chemical composition, microstructural characteristics, etc. of the parent material. Aspects of the present invention methods can be used for, but are not limited to, any solid, metal, or metal alloy, including, but not limited to steels, aluminum, copper, magnesium, nickel, titanium alloy, etc. and is highly suited for alloys which possess limited ambient temperature ductility.
This approach can be extended to other material classes. For example, various approaches have been developed for producing polymeric structures with prismatic cores that can then be fabricated via the means described heretofore, including 3D lattice truss sandwich structures. Ceramic materials with prismatic cores can also be fabricated using “green state” extrusion forming and sintering, in which the material can be laterally machined prior to or after a sintering operation. Edge-defined film fed growth also provides a means for fabricating prismatic structures of the type envisioned here from many types of materials, including ceramics (sapphire for example) and semiconductors (such as silicon).
FIG. 11 is a schematic illustration of one embodiment of p-JBD system 100 interacting with jet 120 . When jet 120 emits a jet blast (not pictured), it interacts with p-JBD 110 or the like. The thermal component of the jet blast is absorbed in to the structure of p-JBD 110 or the like and spread across its surface, and the kinetic component of the jet blast is deflected up and over p-JBD 110 . As the kinetic component passes over the top of p-JBD 110 it must travel over the deployable ejector plate 140 , which creates a low pressure or vacuum region (not pictured) above p-JBD 110 as the kinetic component interacts with the ambient air there. This process pulls cool air 150 , brought into p-JBD 110 through inlet 130 at its base up through the p-JBD structure, thus removing the thermal component of the jet blast stored there. As a result hot air 160 is expelled out the top of p-JBD 110 . It should be appreciated that in some embodiments, p-JBD 110 may be coated with a spray-on non-skid protective surface 170 or any other form of coating designed to provide traction. Passive in this context implies a system that does not necessarily require an active cooling system. Although, it should be appreciated that an active cooling system may be added, supplemented or implemented with the disclosed cooling system and related method disclosed throughout this document regarding the present invention methods and systems. As shown, the p-JBD 110 comprises a plurality of first plates 112 in communication or joined (e.g., side-by-side or laterally) with one another along with their respective second plates 111 on the back side with a core 114 disposed there between.
Further, during assembly of any of the components related with the JBD system a variety of welding or joining techniques may be applied, including, but not limited thereto, friction stir welding for effective joining. Some of the joints, particularly “lap joints” provide open paths to bare aluminum (or desired or required material) of the plates or cores (for example), which in turn may produce undesirable corrosion product in certain instances. To prevent this, optionally special sealants may be employed which are applied during welding (e.g., friction stir welding or as desired or required) to those lap joints.
FIGS. 12 (A)-(C) are schematic illustration of an embodiment of a sandwich structure 1201 demonstrating blast or explosion mitigation in response to an explosion. FIGS. 12 (A)-(C) provide the impulse loading stage, core crushing stage, and panel bending stage, respectively.
FIGS. 13 (A)-(D) are schematic illustration of an embodiment of a sandwich structure 1301 demonstrating projectile arresting capabilities in response to a projectile, which provides various rupture and fracture details. As shown inserts 1305 (e.g., prism shaped) are disposed therein and filler material 1303 (e.g., elastomers) in the interstial space of the sandwich structure 1301 .
The following are exemplary methods and systems of various embodiments of the present invention that can be used to bonded corrugation truss based structures (or any structure as desired/required) from any metal, thus greatly expanding the realm of metals that can be fabricated into truss based structures, as the aforementioned methods (adhesives, diffusion bonding, brazing, soldering or resistance/electron/laser welding, etc.) could only have been fabricated from alloys. In addition, since there is no metallurgical or microstructural discontinuity at the truss-facesheet (truss-faceplate) interface region, the likelihood of corrosion is greatly reduced.
In an exemplary and non-limiting approach of an embodiment, a monolithic sample may be extruded, to form a first corrugation panel. A second monolithic sample may be extruded to form a second corrugation panel. It should be appreciated that the monolithic samples can be aluminum, ceramic, polymer, metal, alloy, and/or any combination of composites thereof, or the like, form depending on the size of the final corrugation truss based structures or any desired/required structure. The two corrugation panels can then be laterally coupled in communication with one another to form a single continuous plurality panel. The term laterally may encompass, for example, side-by-side arrangement or at least substantially side-by-side. The corrugation panels can be coupled using adhesives, diffusion bonding, brazing, soldering or resistance/electron/laser welding, friction stir welding, coupling, etc. The above steps can be repeated to form a continuous plurality panel containing any number of corrugation panels. As discussed herein, various embodiments comprise the structure and related method for the manufacture of a corrugation plurality panel with a prismatic core shape. It should also be appreciated, however, that tetrahedral, Kagome, cone, frustum, or other truss structures may be manufactured via this method as desired or required.
FIG. 14(A) shows an example of an extrusion process whereby a monolithic sample has been extruded to form a corrugation panel 153 , with a prismatic core shape 1507 (as shown in FIG. 14(B) ). It should be appreciated that prior to or after any extrusions the pattern, sample, billet, panel or structure may be fabricated or manipulated by being machined via electro discharge machining, drilling including laser drilling and other ablative removal techniques in which material is melted or evaporated, cut, water jet cutting, chemical dissolution methods or any other suitable operation. At this point, as shown in FIG. 14(B) , the truss based structure 1503 has the form of a single corrugation panel, with a prismatic core shape 1507 , facesheets 1504 enclosing truss units 1505 , forming nodes 1506 where truss units 5 interfaces with the facesheets 1504 .
FIG. 14(B) shows a schematic of a 6061 aluminum alloy that has been extruded with a regular prismatic structure using a 17.8 cm diameter, 300 ton direct extrusion press at 482° C. After this extrusion step, the resulting corrugated core sandwich panel structures, i.e., truss based structure 1503 , had a web thickness of 0.125 in, a core height of 0.75 in, 0.216 in thick facesheets and a web inclination angle of 60 degrees as shown in FIG. 14(B) . The truss units 1505 comprise of a plurality of legs or ligaments 1511 . The legs may have a variety of shapes such as straight or curved and may have a variety of cross-sections. The plurality of truss units 1505 form an array of truss units. While the y-direction path is shown as substantially straight, it should be appreciate that the path may be curved or shaped as desired or required. For instance, the array of truss units and panels (or any related components of the resultant structure) may be fabricated so that the truss units and panels (or any related components) may be contoured or shaped as desired or required. Moreover, while the various extruded paths (x, y, and z) as illustrated appear to be substantially orthogonal or perpendicular respectively with one another, it should be appreciated that any respective angles may be implemented as desired or required for the desired or required fabrication process or resultant truss and/or panel structure. In an embodiment, the monolithic sample may comprise at least one select material as desired or required. In an embodiment, the select material may comprise, for example but not limited thereto, aluminum, ceramic, polymer, metal, metal alloy, and/or any combination of composites thereof (or any material(s) as desired or required. The area that the faceplate or facesheet and truss units intersect form an interface region. In an embodiment, the interface region has the same metallurgical and microstructural properties. In an embodiment, the truss units have nodes wherein the nodes have the same metallurgical and microstructural properties as the truss unit. In an embodiment, the extruding or machining or both the extruding and machining create the truss units of varying relative density. In an embodiment, the nodes have curved or smooth triple point interfaces with the facesheets.
FIG. 14(C) depicts a schematic illustration of a truss unit portion 1505 with nodes 1506 that have curved or smooth triple point interfaces with the face sheet 1504 .
Referring to FIG. 15 , in an exemplary and non-limiting embodiment of an aspect of the present invention, two or more corrugation panels are laterally coupled together to form a single continuous plurality panel. In an embodiment, said coupling comprises said one or more of adhesives, diffusion bonding, brazing, soldering or resistance/electron/laser welding, or friction stir welding. FIG. 15(A) depicts a schematic representation of friction stir welding. FIG. 15(B) depicts a schematic of two or more truss based structures 1503 coupled together to form a plurality panel 1509 containing, in illustration shown, five sets of the corrugation panels with the corresponding facesheets 1504 , truss unit portions 1505 , nodes 1506 , vertical side members 1510 , legs or ligaments 1511 , and weld lines 1512 , etc. The extruded corrugation panels can take on a variety of shapes, dependent only upon the desired topology of the final sandwich structure or any desired/required structure. FIG. 15(B) depicts the corrugation panels of truss based structures 1503 with prismatic core shapes. It is envisioned, however, that tetrahedral, Kagome, cone, frustum, or other truss structures may be manufactured via this method. FIG. 15(B) depicts vertical side members 1510 that are substantially planar. It is envisioned, however that the vertical side members 10 can take on any variety of widths and shapes such as substantially C-shaped or L-shaped. The truss in FIG. 15(B) units 1505 comprise of a plurality of legs or ligaments 1511 . FIG. 15(B) depicts the legs or ligaments 1511 as straight. It is envisioned however, that the legs may have a variety of shapes such as straight or curved and may have a variety of cross-sections. In an embodiment the monolithic samples may comprise at least one select material as desired or required. In an embodiment, the select material may comprise, for example, but not limited thereto, ceramic, polymer, metal, metal alloy, and/or any combination of composites thereof (or any material(s) as desired or required. The area that the facesheet or faceplate and truss units intersect form an interface region. In an embodiment, the interface region has the same metallurgical and microstructural properties. In an embodiment, the truss units have nodes wherein the nodes have the same metallurgical and microstructural properties as the truss unit. In an embodiment, the extruding or machining or both the extruding and machining create the truss units of varying relative density. In an embodiment, the nodes have curved or smooth triple point interfaces with the facesheets.
FIG. 16(A) provides a photographic depiction of a plurality panel 1509 (having five truss based structures 1503 in this instance) comprising 6061-T6 aluminum corrugation panels, coupled by friction stir welding. The corrugation panels of the truss based structures 1503 were extruded from 6061 aluminum alloy and contain weld lines 1512 , with facesheets 1504 enclosing truss units 1505 , forming nodes 1506 where truss legs or ligaments 1511 interfaces with a facesheets 1504 at nodes 1506 . FIG. 16(B) provides a magnified photographic depiction of a portion of the plurality panel 1509 depicted in FIG. 16(A) centered on a weld line 1512 . The plurality panel in depicted in FIG. 16(B) contains weld lines 1512 , with facesheets 1504 enclosing truss units 1505 , forming nodes 1506 where truss legs or ligaments 1511 interfaces with a facesheets 1504 at nodes 1506 . FIG. 16(B) shows that the plurality panel has the following dimensions: a vertical side member thickness of 9.5 mm, a core height of 19.05, and 5.4 mm thick facesheets. It should be appreciated that the dimension, contours, thicknesses, and sizes may vary as desired or required for particular structure, application, or process.
Next, although not shown, in an exemplary and non-limiting embodiment of an aspect of the present invention, these manufacturing techniques may be used to form multi-layered plurality panels, by vertically coupling said plurality panels. Said vertical coupling can comprise claiming, adhesives, diffusion bonding, brazing, soldering or resistance/electron/laser welding, or friction stir welding. Again, the following is a description for the manufacture of a double-layer pyramidal/triangular corrugation plurality panel, however, it is envisioned that tetrahedral, Kagome, cone, frustum, or other lattice-based truss structures of any number of layers may be manufactured via this method. The combination of these two steps produces a multi-layered (in the at least substantially vertical direction) corrugated extrusion plurality panel, with facesheets enclosing truss units, forming nodes where truss legs or ligaments interface with a facesheet at nodes, and containing weld lines. It is noted that the alignment of nodes 6 between adjacent layers is not a prerequisite. As with this embodiment or any embodiments discussed herein, each individual layer may be aligned or offset any amount from adjacent layers, yielding the desired properties for the structure as a whole and the layers individually. Similarly, the truss units may have any number of legs or ligaments according to the fabrication approach. The truss units 1505 comprise of a plurality of legs or ligaments 1511 . The legs may have a variety of shapes such as straight or curved and may have a variety of cross-sections. The plurality of truss units 1505 form an array of truss units. While the y-direction path and the x-direction path are shown as substantially straight, it should be appreciate that the paths may be curved or shaped as desired or required. Moreover, while the various extrusion paths (x, y, and z) as illustrated appear to be substantially orthogonal or perpendicular respectively with one another, it should be appreciated that any respective angles may be implemented as desired or required for the desired or required fabrication process or resultant truss and/or panel structure. For instance, the array of truss units and panels (or any related components of the resultant structure) may be fabricated so that the truss units and panels (or any related components) may be contoured or shaped as desired or required. In an embodiment, the monolithic sample may comprise at least one select material as desire or required. In an embodiment, the select material may comprise, for example but not limited thereto, aluminum, ceramic, polymer, metal, metal alloy, and/or any combination of composites thereof (or any material(s) as desired or required. It should be appreciated that the monolithic sample may be extruded along a plurality of paths, such as two or more as desired or required. The area that the faceplate/facesheet and truss units intersect form an interface region. In an embodiment, the interface region has the same metallurgical and microstructural properties. In an embodiment, the truss units have nodes wherein the nodes have the same metallurgical and microstructural properties as the truss unit. In an embodiment, the extruding or machining or both the extruding and machining create the truss units of varying relative density.
Aspects of various embodiments of the present invention provide, but are not limited to, a novel method and system to manufacture corrugation truss based plurality panels or any desired/required structures that provides enhanced truss-facesheet interface strength by avoiding poor joint design or bonding procedures, which can cause the catastrophic failure of sandwich panels. Although numerous factors determine the robustness of joined nodes (joint composition, microstructure, degree of porosity, geometric constraints, etc.) this new method results in sandwich structures with highly robust nodes that have the equivalent metallurgical, for instance strength, ductility, chemical composition, microstructural characteristics, etc. of the parent material. Aspects of the present invention methods can be used for, but are not limited to, any solid, metal, or metal alloy, including, but not limited to steels, aluminum, copper, magnesium, nickel, titanium alloy, etc. and is highly suited for alloys which possess limited ambient temperature ductility.
This approach can be extended to other material classes. For example, various approaches have been developed for producing polymeric structures with prismatic cores that can then be fabricated via the means described heretofore, including truss based sandwich structures. Ceramic materials with prismatic cores can also be fabricated using “green state” extrusion forming and sintering, in which the material can be laterally machined prior to or after a sintering operation. Edge-defined film fed growth also provides a means for fabricating prismatic structures of the type envisioned here from many types of materials, including ceramics (sapphire for example) and semiconductors (such as silicon).
It should be appreciated that prior to or after any extrusions the sample, billet, panel, or structure may be fabricated or manipulated by machining (e.g., machined via electro discharge machining), cutting or any other suitable operation as discussed in U.S. patent application Ser. No. 12/447,166, filed Apr. 24, 2009, entitled “Manufacture of Lattice Truss Structures from Monolithic Materials” and it's corresponding PCT International Application No. PCT/US/2007/022733, filed Oct. 26, 2007; of which the disclosures are hereby incorporated by reference herein in their entirety.
EXAMPLES
Example and Experimental Results Set No. 1
Practice of the invention will be still more fully understood from the following examples and experimental results, which are presented herein for illustration only and should not be construed as limiting the invention in any way.
An aspect of an embodiment of this invention may comprise an extrusion and electro discharge machining (EDM) method has been developed to fabricate a pyramidal lattice core sandwich structure. The approach is readily extendable to tetrahedral and to multilayer versions of these lattices. In this approach, a 6061 aluminum alloy corrugated core sandwich panel is first extruded, creating an integral core and facesheets, fashioned from a single sample of material. The corrugated core (or any core shape as desired or required) is then penetrated by an alternating pattern of triangular shaped EDM electrodes normal to the extrusion direction to form the pyramidal lattice. The process results in a sandwich panel in which the core-facesheet nodes posses the parent materials' metallurgical and mechanical properties. The out-of-plane compression and in-plane shear mechanical properties of the structure have been measured and found to be very well predicted by analytical estimates.
Referring to FIG. 5 , a sample 41 , such as an extrusion billet for example, comprising 6061 aluminum alloy, was extruded with a regular prismatic structure using extrusion press 43 (as schematically shown by the dotted lines) by a heat source 42 . In this example the heat is applied at 482° C. and the press 43 (having flow channels 45 ) has a dimension of 17.8 cm diameter, 300 ton direct extrusion press at 482° C., resulting in a corrugated core sandwich panel structure 44 , such as a long extrusion stick.
Referring to FIG. 6(A) , after this extrusion step (as shown in FIG. 5 ), the resulting corrugated core sandwich panel structure 44 had a web thickness of 3.2 mm as designated by arrow WT, a core height of 19.1 mm as designated by the arrow CH, and a facesheet thickness of 5.2 mm as designated as FT and a web inclination angle of 60° as designated by arrow WI. The relative density of the corrugated core was 25%. The extruded panels were solutionized, water-quenched and heat-treated to a T6 condition. An alternating pattern of triangular shaped EDM electrodes (not shown) were then inserted normal to the extrusion direction as illustrated in FIG. 6(A) as the patterns to be removed 51 to form the pyramidal lattice sandwich panel, as shown FIG. 6(B) . The triangular plates are shown as cutouts 52 that are perpendicular to the extrusion. The process resulted in a sandwich panel in which the core-facesheet nodes 13 had identical microstructure, composition and mechanical properties to those of the trusses 14 and facesheets 11 .
It should be appreciated that any dimensions or angles shown herein are exemplary and illustrative only and should not be construed as limiting the invention in any way. The sizes, materials, flexibility, rigidness, shapes, contours, angles or dimensions discussed or shown may be altered or adjusted as required or desired.
FIG. 7 shows a photographic depiction of one of the pyramidal lattice sandwich structures. It is 4 unit cells wide by 4 unit cells long as shown by the respective truss-units 12 , and was used for compression measurements. The shear response was measured using samples (not shown) that were 4 unit cells wide and 10 unit cells long.
Test Results
The relative density can be derived for the pyramidal structure depends upon the truss cross sectional area, t 2 , its inclination angle, ω, and length, l. The ratio of the metal volume in a unit cell to that of the unit cell then gives the relative density:
ρ
_
=
2
t
2
l
2
sin
ω
cos
2
ω
·
l
2
cos
2
ω
(
l
cos
ω
+
2
t
)
2
.
(
1
)
For the samples manufactured here, t=3.2 mm, l=24.6 mm and ω=50.77° resulting in a predicted relative density of 6.5%. The experimentally measured relative density was 6.2±0.01%.
The lattice truss structures were tested at ambient temperature in compression and shear at a nominal strain rate of 10 −2 s −1 in accordance with ASTM C365 and C273 using a compression shear plate configuration. A laser extensometer measured the compressive strain by monitoring the displacements of the unconstrained facesheets (with a displacement precision of ±0.001 mm. The shear strain was obtained by monitoring the displacements of the shear plates with a measurement precision of ±0.010 mm.
Referring to FIG. 8 , the through thickness compressive stress-strain response pertaining to the pyramidal lattice sandwich structure substantially shown in FIG. 7 is graphically shown in FIG. 8(A) . FIGS. 8 (B)-(G) show photographic depictions of the lattice deformation at strain levels (ε) of 0, 5, 10, 15, 20 and 25%, respectively. Following an initial linear response, a peak was observed in the compressive stress that coincided with initiation of the buckling of the lattice truss members and the formation of a plastic hinge near the center of the truss members. Continued loading resulted in core softening up to an engineering strain of ˜0.25 at which point the load carrying capacity increased rapidly as the deformed trusses made contact with the facesheets. During the core-softening phase, small fractures were observed to form on the tensile stressed side of the trusses. These were first seen at strains of between 0.10 and 0.12. No failures at the truss-facesheet nodes were observed during any of the tests.
Referring to FIG. 9(A) , the in-plane shear stress-strain response pertaining to the pyramidal lattice sandwich structure substantially shown in FIG. 7 is graphically shown in FIG. 9(A) . FIGS. 9 (B)-(D) show photographic depictions of the lattice deformation at strain levels (γ) of 0, 6 and 12%, respectively. In this test orientation, each unit cell had two truss members loaded in compression and two in tension. The sample exhibited characteristics typical of lattice truss based sandwich cores including: elastic behavior during initial loading and increasing load support capability until the peak strength was reached. Continued loading continued at a constant stress up to a strain of ˜0.13, at which point the sample failed by fracture of the tensile loaded lattice members near their midpoint. Some plastic buckling was observed on truss members at the ends of the sandwich panel. It is a manifestation of the compressive loading component of the ASTM 273 test method. No evidence of node failure was observed during any of the shear experiments.
Tensile coupons of the aluminum 6061 alloy were used to determine the mechanical properties of the parent aluminum alloy. Tensile tests were performed according to ASTM E8 at a strain rate of 10 −3 s −1 . The average Young's modulus, E s , and 0.2% offset yield strength, σ ys , were 69 GPa and 268 MPa, respectively. The tangent modulus, E t , at the inelastic bifurcation stress was 282 MPa.
The peak strength of a lattice truss core is determined by the mechanism of strut failure which, in turn, depends on the cell geometry, strut material properties and the mode of failure loading. Table 1 summarizes the micromechanical predictions for the pyramidal lattice. The micromechanical predictions for the compressive and shear peak strength are shown in FIGS. 8(A) and 9(A) for truss members that fail by plastic yielding or inelastic buckling. There is excellent agreement between the analytical model predictions of the peak strengths and the observed modes of deformation.
The compression and shear stiffnesses were measured from periodic unload/reload measurements. FIG. 10(A) graphically shows the non-dimensional compressive stiffness, Π=E c /(E s ρ ), versus compressive strain (here E c and E s are the Young's moduli of the core and the solid parent alloy respectively, and ρ is, again, the relative density). The predicted non-dimensional compressive stiffness is 0.36. The experimental data fall slightly above 0.36 just prior to attainment of the peak strength and then decrease during the inelastic buckling phase of deformation. FIG. 10(B) graphically shows the non-dimensional shear stiffness, Γ=G c /(E s ρ ), versus shear strain (here G c is the shear stiffness of the core). The predicted non-dimensional shear stiffness of 0.12 and the experimental data are in excellent agreement up until failure of the panel.
Table 1 provides the analytical expressions for the compression and shear stiffness and strength of a pyramidal lattice truss core sandwich structure.
TABLE 1
Mechanical Property:
Analytical Expression:
Compressive stiffness
E c = ρ E s · sin 4 ω
Compressive strength
σ pk = ρ σ ys · sin 2 ω
(plastic yielding)
Compressive strength
σ pk = ρ σ cr · sin 2 ω
(inelastic buckling)
Shear stiffness
G
c
=
ρ
_
·
1
8
E
s
·
sin
2
2
ω
Shear strength (plastic yielding)
τ
pk
=
ρ
_
·
1
2
2
σ
ys
·
sin
2
ω
Shear strength (inelastic buckling)
τ
pk
=
ρ
_
·
1
2
2
σ
cr
sin
2
ω
A new method for fabricating a lattice truss core sandwich panel structure has been developed using a combination of extrusion and electro discharge machining. The approach has been illustrated by the fabrication and mechanical property evaluation of sandwich panels made from a 6061 aluminum alloy; however, the method is applicable to any alloy system that can be easily extruded. For materials that can not be extruded, the electro discharge machining method could be performed in two directions (instead of one as described here) on a monolithic plate resulting in a similar lattice structure. This alternative method, therefore, is extendable to most conductive material systems or other material systems as desired or required.
The measured peak compressive and shear strengths were found to be in excellent agreement with the micromechanical model predictions for the operative truss member failure mechanisms: inelastic buckling for compression and plastic yielding (followed by tensile fracture) for shear. The non-dimensional compression and shear moduli coefficients were found to be in excellent agreement with the analytical predictions.
Conventional sandwich panel structures suffer from node failure during static and dynamic testing. These failures are initiated at defects or in weak or embrittled regions that result from core-faceplate bonding (facesheet bonding) processes. Whereas, the present invention fabrication method described above, results in sandwich panels in which the core-facesheet nodes have identical material properties to those of the trusses and facesheets. Joining methods such as brazing or welding have been eliminated with this process. No evidence of nodal failure was observed during compression or shear loading of the samples fabricated by the method described here.
The method of sandwich panel manufacture described here has been used to fabricate sandwich panels that eliminate the incidence of nodal failures. The panels' mechanical properties are found to be governed only by the geometry of the sandwich panel, the alloy mechanical properties, and the mode of loading. These properties are well predicted by recent micromechanical models.
Example and Experimental Results Set No. 2
An aspect of an embodiment of this invention may comprise an extrusion developed to fabricate a pyramidal corrugation truss based corrugation panels, laterally coupled by a process comprising friction stir welding to form corrugation plurality panels. The approach is readily extendable to tetrahedral and to multilayer versions of these trusses. In this approach, multiple 6061 aluminum alloy corrugated core sandwich panels is first extruded, creating an integral cores and facesheets, fashioned from a single samples of material. The corrugated cores (or any core shape as desired or required) are then laterally coupled by friction stir welding to form a continuous plurality panel. The process results in a sandwich panel in which the core-facesheet nodes posses the parent materials' metallurgical and mechanical properties. The out-of-plane compression and in-plane shear mechanical properties of the structure have been measured and found to be very well predicted by analytical estimates.
Referring to FIG. 14(A) , a sample 1514 , such as an extrusion billet 14 for example, comprising 6061 aluminum alloy, was extruded with a regular prismatic structure using extrusion press 1516 (as schematically shown by the dotted lines) by a heat source 1515 . In this example the heat is applied at 482° C. and the press 1516 (having flow channels 1518 ) has a dimension of 17.8 cm diameter, 300 ton direct extrusion press at 482° C., resulting in a corrugated core sandwich panel structure 1517 , such as a long extrusion stick. It should be appreciated that the temperature, dimension and force may vary as desired or required for particular structure or process.
Referring to FIG. 14(B) , after this extrusion step (as shown in FIG. 14 (A)), the resulting corrugated core sandwich panel structure 1503 had a web thickness of 0.125 in, a core height of 0.75 in, 0.216 in thick facesheets and a web inclination angle of 60 degrees. The relative density of the corrugated core was 29%. The extruded panels were solutionized, water-quenched and heat-treated to a T6 condition. Plurality panels were formed by laterally coupling these corrugation panels by friction stir welding. Referring to FIG. 16(A) five corrugation panels welded by friction stir welding to create corrugation plurality panels containing 0.37 mm thick vertical side members. Plurality panels as depicted in FIG. 16(A) were used in mine blast testing experiments.
It should be appreciated that any dimensions or angles shown herein are exemplary and illustrative only and should not be construed as limiting the invention in any way. The sizes, materials, flexibility, rigidness, shapes, contours, angles or dimensions discussed or shown may be altered or adjusted as required or desired.
Test Results—Mine Blast Simulation
A “Black Widow” blast testing rig (the “Rig”) was used to measure the performance of the corrugation plurality panels 1509 described above and as shown in FIG. 16(A) . FIG. 18(A) depicts a diagram of the Rig. The perimeter of the corrugation plurality panel 1509 was clamped to 0.75 in thick steel back support plate that lay underneath the corrugation plurality panel and a clamping plate that lay on top of the plurality panel. FIG. 18(B) provides a photograph of the Rig with the “wet sand” charge (the “charge”) at a standoff distance of 19 cm. The charge is made of 375 grams of C-4 explosive enclosed in a spherical shell having a diameter of 80 mm. In addition to the C-4 explosive, the remaining volume of the shell was filled with 2.466 kg of 200 μm diameter glass spheres to simulate sand and 0.617 kg of water. FIGS. 18 (C)-(H) provide a schematic depicting the process for constructing the charge. The tests were performed at four standoff distances: 15, 19, 22, and 25 cm. Corrugation plurality panel performance at each standoff distance was compared against equivalent mass monolithic 6061-Al plates (“monolithic plates”) that were 17 mm thick. FIG. 17(A) graphs hardness of the corrugation plurality panels in MPa as a function of distance from the weld. A weld line 1512 , for example, is highlighted in FIG. 16(A) . FIG. 17(A) shows that the hardness drops off sharply within 1 cm of the weld line from approximately 390 MPa at approximately 2 cm away from the weld line all the way down to approximately 270 MPa at the weldline. FIG. 17(B) graphs the true stress in MPa as a function of true strain for both the parental material (i.e. 6061 aluminum alloy) and the friction stir welded (“FSW”) 6061 aluminum alloy. The true stress for both the friction stir welded material and the parental material begins level off at an approximately true strain of approximately 0.01.
FIG. 19(A) provides a graph of back facesheet deflection after the charge detonation for both the corrugation plurality panels and the monolithic plates at each of the respective standoff distances. FIG. 19(B) provides the same information in a tabular form. The corrugated plurality panel “failed” at the 15 cm standoff as the back facesheet was displaced by 55 mm. The mass equivalent monolithic plate by contrast did not fail and the back facesheet deflection was 47 mm. However, for each of the other charge standoff distances, the corrugated plurality panel 1509 had smaller back facesheet deflections than did the mass equivalent monolithic plates at the corresponding charge standoff distances as shown in FIGS. 19(A) and (B).
FIG. 20(A) shows post blast photographs of the corrugation plurality panels 1509 at each of the charge standoff distances (15, 19, 22, and 25 cm) and FIG. 20(B) shows post blast photographs of the mass equivalent monolithic plates at each of the charge standoff distances (15, 19, 22, and 25 cm).
FIGS. 21(A) and (B) show post blast photographs of a corrugation plurality panel 1509 after subjection to charge detonation at 25 cm standoff. FIG. 21(A) shows some tearing along the region of the corrugation plurality panel 1509 that was clamped to the clamping plate and the back support plate (“clamped region”) in the direction parallel to corrugations. However, there was no crack propagation along the weld. FIG. 21(B) shows photographs of the cross section of the corrugation plurality panel 1509 of FIG. 21(A) , which displays the post blast displacement.
FIGS. 22(A) and (B) show post blast photographs of a corrugation plurality panel 1509 at a standoff distance of 22 cm. FIG. 22(A) shows tearing along the edge of the weld in the direction parallel to corrugations. FIG. 22(B) shows cross sections of the corrugation plurality panel 1509 of FIG. 22(A) , which displays the post blast displacement.
FIGS. 23(A) and (B) show post blast photographs of a corrugation plurality panel 1509 at a standoff distance of 19 cm. FIG. 23(A) shows tearing along edge of weld in direction parallel to corrugations. FIG. 23(B) shows cross sections of the corrugation plurality panel 1509 of FIG. 23(A) having an edge with partial tearing that displays the post blast displacement.
FIGS. 24(A) and (B) show post blast photographs of a corrugation plurality panel 1509 at a standoff distance of 15 cm. FIG. 24(A) shows catastrophic failure in the center of corrugation plurality panel 1509 of FIG. 24(A) having an edge with tearing in the direction perpendicular to the corrugations. FIG. 24(B) shows cross sections of the corrugation plurality panel 1509 that displays the post blast displacement.
The table of FIG. 25 summarizes the failure modes of the corrugated plurality panels at each of the charge standoffs described above.
REFERENCES CITED
The following patents, applications and publications as listed below and throughout this document are hereby incorporated by reference in their entirety herein. The devices, systems, articles of manufacture and methods of various embodiments of the present invention disclosed herein may utilize aspects disclosed in the following patents and applications and are hereby incorporated by reference in their entirety:
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European Journal of Mechanics—A/Solids, 25 (2), 215-229. Queheillalt, D. T. and Wadley, H. N. G., 2005. Pyramidal lattice truss structures with hollow trusses. Materials Science and Engineering A, 397 (1-2), 132-137. Queheillalt, D. T. and Wadley, H. N. G., Titanium Alloy Lattice Truss Structures. Materials and Design 2007: Submitted March 2007. Radford, D. D., Fleck N. A. and Deshpande, V. S., 2006. The response of clamped sandwich beams subjected to shock loading. International Journal of Impact Engineering, 32 (6), 968-987. Rathbun, H. J., Wei, Z., He, M. Y., Zok, F. W., Evans, A. G., Sypeck, D. J. and Wadley, H. N. G., 2004. Measurement and Simulation of the Performance of a Lightweight Metallic Sandwich Structure with a Tetrahedral Truss Core. Journal of Applied Mechanics, 71 (3), 305-435. Sugimura, Y., 2004. Mechanical response of single-layer tetrahedral trusses under shear loading. Mechanics of Materials, 36 (8), 715-721. Sypeck, D. J. and Wadley, H. N. G., 2002. Cellular metal truss core sandwich structures. Advanced Engineering Materials, 4 (10), 759-764. Wadley, H. N. G., Multifunctional periodic cellular metals. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 2006; 364:31-68. Wadley, H. N. G., Fleck, N. A. and Evans, A. G., Fabrication and structural performance of periodic cellular metal sandwich structures. Composites Science and Technology 2003; 63:2331-2343. Wallach, J. C. and Gibson, L. J., 2001. Mechanical behavior of a three-dimensional truss material. International Journal of Solids and Structures, 38 (40-41), 7181-7196. Wang, J., Evans, A. G., Dharmasena, K. and Wadley, H. N. G., 2003. On the performance of truss panels with Kagome cores. International Journal of Solids and Structures 40 (25), 6981-6988. Zhou, J., Shrotiriya, P. and Soboyejo, W. O., 2004. On the deformation of aluminum lattice block structures from struts to structure. Mechanics of Materials, 36 (8), 723-737. Zok, F. W., Waltner, S. A., Wei, Z., Rathbun, H. J., McMeeking, R. M. and Evans, A. G., 2004. A protocol for characterizing the structural performance of metallic sandwich panels: application to pyramidal truss cores. International Journal of Solids and Structures 41 (22-23) 6249-6271. European Patent No. 858,069 entitled “Extrusion of Metals”. European Patent No. EP0 904,914 B1 to Sugiura, et al., entitled “Method for Forming a Molding”. U.S. Pat. No. 3,364,707 to Foerster entitled “Extrusion Forming Member and Method”. U.S. Pat. No. 4,878,370 to Fuhrman, et al., entitled “Cold Extrusion Process for Internal Helical Gear Teeth”. U.S. Pat. No. 1,365,987 to Hadfield, et al., entitled “Manufacture of Gun Tubes and Like Tubular Bodies”. International Patent Application Publication No. WO 2005/059187 A3 to Ungurean entitled “Solid Shapes Extrusion”. International Patent Application Publication No. WO 2005/059187 A2 to Ungurean entitled “Solid Shapes Extrusion”. 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No. 3,014,269 to Graham, et al., “Manufacture of Hollow Turbine Blades” International Patent Application Publication No. WO 2008/153613 A2 to Ungurean entitled “Solid Shapes Extrusion”. U.S. Pat. No. 4,280,393 to Giraud et al., entitled “Light Weight Armored Vehicle.”
In summary, while the present invention has been described with respect to specific embodiments, many modifications, variations, alterations, substitutions, and equivalents will be apparent to those skilled in the art. The present invention is not to be limited in scope by the specific embodiment described herein. Indeed, various modifications of the present invention, in addition to those described herein, will be apparent to those of skill in the art from the foregoing description and accompanying drawings. Accordingly, the invention is to be considered as limited only by the spirit and scope of the following claims, including all modifications and equivalents.
Still other embodiments will become readily apparent to those skilled in this art from reading the above-recited detailed description and drawings of certain exemplary embodiments. It should be understood that numerous variations, modifications, and additional embodiments are possible, and accordingly, all such variations, modifications, and embodiments are to be regarded as being within the spirit and scope of this application. For example, regardless of the content of any portion (e.g., title, field, background, summary, abstract, drawing figure, etc.) of this application, unless clearly specified to the contrary, there is no requirement for the inclusion in any claim herein or of any application claiming priority hereto of any particular described or illustrated activity or element, any particular sequence of such activities, or any particular interrelationship of such elements. Moreover, any activity can be repeated, any activity can be performed by multiple entities, and/or any element can be duplicated. Further, any activity or element can be excluded, the sequence of activities can vary, and/or the interrelationship of elements can vary. Unless clearly specified to the contrary, there is no requirement for any particular described or illustrated activity or element, any particular sequence or such activities, any particular size, speed, material, dimension or frequency, or any particularly interrelationship of such elements. Accordingly, the descriptions and drawings are to be regarded as illustrative in nature, and not as restrictive. Moreover, when any number or range is described herein, unless clearly stated otherwise, that number or range is approximate. When any range is described herein, unless clearly stated otherwise, that range includes all values therein and all sub ranges therein. Any information in any material (e.g., a United States/foreign patent, United States/foreign patent application, book, article, etc.) that has been incorporated by reference herein, is only incorporated by reference to the extent that no conflict exists between such information and the other statements and drawings set forth herein. In the event of such conflict, including a conflict that would render invalid any claim herein or seeking priority hereto, then any such conflicting information in such incorporated by reference material is specifically not incorporated by reference herein.
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Methods and systems to manufacture bonded corrugation truss-based structures. This allows the ability to change the dimensions of the individual structural features of the corrugations, i.e. thickness of the core, face sheet thickness, relative density of the core, and the alloys. The nodal design which provides ideal stress/strain distribution for in-plane and out-off plane loading. The node has a curved/smooth triple point intersection which in turn can provide best load transfer interface with high integrity/toughness. The bonded corrugation truss based structure can be continuous to any length only limited by the volume of the extrusion billet and the press capacity. An aspect of the bonded corrugation structures may include friction stir welding of the face sheets or any fusion welding of panels with edge members for strengthening allows fabrication of panels of any width and length. Bonding panels enables the fabrication of structures of any width.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to medical devices comprising synergistic combinations of triclosan and chlorhexidine.
[0002] Whenever a medical device comes in contact with a patient, a risk of infection is created. Thus, a contaminated examination glove, tongue depressor, or stethoscope could transmit infection. The risk of infection dramatically increases for invasive medical devices, such as intravenous catheters, arterial grafts, intrathecal or intracerebral shunts and prosthetic devices, which not only are, themselves, in intimate contact with body tissues and fluids, but also create a portal of entry for pathogens.
[0003] A number of methods for reducing the risk of infection have been developed which incorporate anti-infective agents into medical devices, none of which have been clinically proven to be completely satisfactory. Such devices desirably provide effective levels of anti-infective agent during the entire period that the device is being used. This sustained release may be problematic to achieve, in that a mechanism for dispersing anti-infective agent over a prolonged period of time may be required, and the incorporation of sufficient amounts of anti-infective agent may adversely affect the surface characteristics of the device. The difficulties encountered in providing effective anti-microbial protection increase with the development of drug-resistant pathogens.
[0004] One potential solution to these problems is the use of a synergistic combination of anti-infective agents that requires relatively low concentrations of individual anti-infective agents which may have differing patterns of bioavailability.
[0005] Two well known anti-infective agents are chlorhexidine and triclosan. The following patents and patent application relate to the use of chlorhexidine and/or triclosan in medical devices.
[0006] U.S. Pat. No. 4,723,950 by Lee relates to a microbicidal tube which may be incorporated into the outlet tube of a urine drainage bag. The microbicidal tube is manufactured from polymeric materials capable of absorbing and releasing anti-microbial substances in a controllable, sustained, time-release mechanism, activated upon contact with droplets of urine, thereby preventing the retrograde migration of infectious organisms into the drainage bag. The microbicidal tube may be produced by one of three processes: (1) a porous material, such as polypropylene, is impregnated with at least one microbicidal agent, and then coated with a hydrophilic polymer which swells upon contact with urine, causing the leaching-out of the microbicidal agent; (2) a porous material, such as high density polyethylene, is impregnated with a hydrophilic polymer and at least one microbicidal agent; and (3) a polymer, such as silicone, is compounded and co-extruded with at least one microbicidal agent, and then coated with a hydrophilic polymer. A broad range of microbicidal agents are disclosed, including chlorhexidine and triclosan, and combinations thereof. The purpose of Lee's device is to allow the leaching out of microbicidal agents into urine contained in the drainage bag; similar leaching of microbicidal agents into the bloodstream of a patient may be undesirable.
[0007] U.S. Pat. No.5,091,442 by Milner relates to tubular articles, such as condoms and catheters, which are rendered antimicrobially effective by the incorporation of a non-ionic sparingly soluble antimicrobial agent, such as triclosan. The tubular articles are made of materials which include natural rubber, polyvinyl chloride and polyurethane. Antimicrobial agent may be distributed throughout the article, or in a coating thereon. A condom prepared from natural rubber latex containing 1% by weight of triclosan, then dipped in an aqueous solution of chlorhexidine, is disclosed. U.S. Pat. Nos. 5,180,605 and 5,261,421, both by Milner, relate to similar technology applied to gloves.
[0008] U.S. Pat. Nos. 5,033,488 and 5,209,251, both by Curtis et al., relate to dental floss prepared from expanded polytetrafluoroethylene (PTFE) and coated with microcrystalline wax. Antimicrobial agents such as chlorhexidine or triclosan may be incorporated into the coated floss.
[0009] U.S. Pat. No.5,200,194 by Edgren et al. relates to an oral osmotic device comprising a thin semipermeable membrane wall surrounding a compartment housing a “beneficial agent” (that is at least somewhat soluble in saliva) and a fibrous support material composed of hydrophilic water-insoluble fibers. The patent lists a wide variety of “beneficial agents” which may be incorporated into the oral osmotic device, including chlorhexidine and triclosan.
[0010] U.S. Pat. No. 5,019,096 by Fox, Jr. et al. relates to infection-resistant medical devices comprising a synergistic combination of a silver salt (such as silver sulfadiazine) and chlorhexidine.
[0011] International Patent Application No. PCT/GB92/01481, Publication No. WO 93/02717, relates to an adhesive product comprising residues of a co-polymerizable emulsifier comprising a medicament, which may be povidone iodine, triclosan, or chlorhexidine.
[0012] In contrast to the present invention, none of the above-cited references teach medical articles comprising synergistic combinations of chlorhexidine and triclosan which utilize relatively low levels of these agents.
SUMMARY OF THE INVENTION
[0013] The present invention relates to polymeric medical articles comprising the anti-infective agents chlorhexidine and triclosan. It is based, at least in part, on the discovery that the synergistic relationship between these compounds permits the use of relatively low levels of both agents, and on the discovery that effective antimicrobial activity may be achieved when these compounds are comprised in either hydrophilic or hydrophobic polymers. It is also based on the discovery that chlorhexidine free base and triclosan, used together, are incorporated into polymeric medical articles more efficiently. Medical articles prepared according to the invention offer the advantage of preventing or inhibiting infection while avoiding undesirably high release of anti-infective agent, for example into the bloodstream of a subject.
DETAILED DESCRIPTION OF THE INVENTION
[0014] The present invention relates to medical articles comprising synergistic combinations of chlorhexidine and triclosan.
[0015] Chlorhexidine may be provided by way of any form, salt or derivative thereof, including but not limited to chlorhexidine free base and chlorhexidine salts such as chlorhexidine diphosphanilate, chlorhexidine digluconate, chlorhexidine diacetate, chlorhexidine dihydrochloride, chlorhexidine dichloride, chlorhexidine dihydroiodide, chlorhexidine diperchlorate, chlorhexidine dinitrate, chlorhexidine sulfate, chlorhexidine sulfite, chlorhexidine thiosulfate, chlorhexidine di-acid phosphate, chlorhexidine difluoro-phosphate, chlorhexidine diformate, chlorhexidine dipropionate, chlorhexidine di-iodobutyrate, chlorhexidine di-n-valerate, chlorhexidine dicaproate, chlorhexidine malonate, chlorhexidine succinate, chlorhexidine malate, chlorhexidine tartrate, chlorhexidine dimonoglycolate, chlorhexidine monodiglycolate, chlorhexidine dilactate, chlorhexidine di-α-hydroxyisobutyrate, chlorhexidine diglucoheptonate, chlorhexidine di-isothionate, chlorhexidine dibenzoate, chlorhexidine dicinnamate, chlorhexidine dimandelate, chlorhexidine di-isophthalate, chlorhexidine di-2-hydroxynaphthoate, and chlorhexidine embonate. The term “chlorhexidine”, as used herein, may refer to any of such forms, derivatives, or salts, unless specified otherwise. Chlorhexidine salts may be solubilized using polyethylene glycol or propylene glycol, or other solvents known in the art.
[0016] The term triclosan refers to a compound also known as 2,4,4′-trichloro-2′-hydroxydiphenyl ether.
[0017] Medical articles that may be treated according to the invention are either fabricated from or coated or treated with biomedical polymer and include, but are not limited to, catheters including urinary catheters and vascular catheters (e.g., peripheral and central vascular catheters), wound drainage tubes, arterial grafts, soft tissue patches, gloves, shunts, stents, tracheal catheters, wound dressings, sutures, guide wires and prosthetic devices (e.g., heart valves and LVADs). Vascular catheters which may be prepared according to the present invention include, but are not limited to, single and multiple lumen central venous catheters, peripherally inserted central venous catheters, emergency infusion catheters, percutaneous sheath introducer systems and thermodilution catheters, including the hubs and ports of such vascular catheters.
[0018] The present invention may be further applied to medical articles that have been prepared according to U.S. Pat. No. 5,019,096 by Fox, Jr. et al.
[0019] The present invention provides, in various alternative non-limiting embodiments, for: (1) compositions which provide a local concentration of chlorhexidine of between 100 and 2000 μg/ml and a local concentration of triclosan of between 250 and 2000 μg/ml; (2) treatment solutions of a polymer comprising between 1 and 5 percent, and preferably between 1.5 and 2.25 percent, of chlorhexidine; and between 0.5 and 5 percent, and preferably between 0.5 and 2 percent, of triclosan, wherein a medical article may be dipped or soaked in the polymer solution; (3) medical articles treated with a treatment solution as set forth in (2) above, and articles physically equivalent thereto (that is to say, articles prepared by a different method but having essentially the same elements in the same proportions); (4) treatment solutions of a polymer comprising between 1 and 5 percent, and preferably between 1.5 and 2.25 percent, of chlorhexidine; between 0.5 and 5 percent, and preferably between 0.5 and 2 percent, of triclosan; and between 0.5 and 1 percent (preferably 0.75 percent) of silver sulfadiazine, wherein a medical article may be dipped or soaked in the polymer solution; and (5) medical articles treated with a treatment solution set forth in (4) above, and articles physically equivalent thereto (that is to say, articles prepared by a different method but having essentially the same elements in the same proportions). Percentages recited herein refer to percent by weight, except as indicated otherwise.
[0020] In preferred embodiments, the ratio, by weight, of the total amount of anti-infective agent to polymer in the treatment solution is less than 1.5.
[0021] In one particular non-limiting embodiment, the present invention provides for a hydrophilic polymeric medical article (i.e., a medical article fabricated from a hydrophilic polymer) treated by dipping or soaking the article in a treatment solution of a hydrophilic polymer comprising chlorhexidine and triclosan wherein the chlorhexidine and triclosan are present in amounts such that their combination, in the treated article, has effective antimicrobial activity. The terms “treat”, “treated”, etc., as used herein, refer to coating, impregnating, or coating and impregnating a medical article with polymer/anti-infective agent. The term “hydrophilic polymer”, as used herein, refers to polymers which have a water absorption greater than 0.6 percent by weight (and, in preferred embodiments, less than 2 percent by weight; as measured by a 24 hour immersion in distilled water, as described in ASTM Designation D570-81) including, but not limited to biomedical polyurethanes (e.g., ether-based polyurethanes and ester-based polyurethanes, as set forth in Baker, 1987, in Controlled Release of Biologically Active Agents, John Wiley and Sons, pp. 175-177 and Lelah and Cooper, 1986, Polyurethanes in Medicine, CRC Press, Inc., Fla. pp. 57-67; polyurethanes comprising substantially aliphatic backbones such as Tecoflex™ 93A; polyurethanes comprising substantially aromatic backbones such as Tecothane™; and Pellethane™), polylactic acid, polyglycolic acid, natural rubber latex, and gauze or water-absorbent fabric, including cotton gauze and silk suture material. In a specific, non-limiting embodiment, the hydrophilic medical article is a polyurethane catheter which has been treated with (i.e., dipped or soaked in) a treatment solution comprising (i) between about 1 and 10 percent, preferably between about 2 and 6 percent, and more preferably about 3 percent, of a biomedical polyurethane; (ii) between 1 and 5 percent, and preferably between 1.5 and 2.25 percent, of chlorhexidine; and (iii) between 0.5 and 5 percent, and preferably between 0.5 and 2 percent, of triclosan. In related non-limiting embodiments of the invention, the treatment solution may further comprise silver sulfadiazine, preferably in a concentration of between 0.5 and 1 percent (more preferably 0.75 percent). Section 6, below, presents working examples of embodiments set forth in this paragraph.
[0022] In another particular non-limiting embodiment, the present invention provides for a hydrophilic polymeric medical article treated by dipping or soaking the article in a treatment solution of a hydrophobic polymer comprising chlorhexidine and triclosan, wherein the chlorhexidine and triclosan are present in amounts such that their combination, in the treated article, has effective antimicrobial activity. The term “hydrophobic polymer”, as used herein, refers to a polymer which has a water absorption of less than 0.6 percent and includes, but is not limited to, silicone polymers such as biomedical silicones (e.g., Silastic Type A) or elastomers (e.g., as set forth in Baker, 1987, in Controlled Release of Biologically Active Agents, John Wiley and Sons, pp.156-162), Dacron, polytetrafluoroethylene (PTFE, also “Teflon”), polyvinyl chloride, cellulose acetate, polycarbonate, and copolymers such as silicone-polyurethane copolymers (e.g., PTUE 203 and PTUE 205 polyurethane-silicone interpenetrating polymer). In a specific, non-limiting embodiment, the medical article is a polyurethane catheter which has been dipped or soaked in a treatment solution comprising (i) between about 1 and 10 percent, preferably between about 2 and 6 percent, and more preferably about 3 percent, of a polyurethane—silicone copolymer; (ii) between 1 and 5 percent, and preferably between 1.5 and 2.25 percent, of chlorhexidine; and (iii) between 0.5 and 5 percent, and preferably between 0.5 and 2 percent, of triclosan. In related non-limiting embodiments of the invention, the treatment solution may further comprise silver sulfadiazine, preferably in a concentration of between 0.5 and 1 percent (more preferably 0.75 percent). Section 7, below, presents working examples of embodiments set forth in this paragraph.
[0023] In another particular non-limiting embodiment, the present invention provides for a hydrophobic polymeric medical article treated by dipping or soaking the article in a treatment solution of hydrophobic polymer comprising chlorhexidine and triclosan, wherein the chlorhexidine and triclosan are present in amounts such that their combination, in the treated article, has effective antimicrobial activity. In a specific, non-limiting embodiment, the medical article is a silicone catheter or a polyvinylchloride catheter which has been dipped or soaked in a treatment solution comprising (i) between about 1 and 10 percent, and preferably about 5 percent, of a silicone polymer; (ii) between 1 and 5 percent, and preferably between 1.5 and 2.25 percent, of chlorhexidine; and (iii) between 0.5 and 5 percent, and preferably between 0.5 and 2 percent, of triclosan. In related non-limiting embodiments of the invention, the treatment solution may further comprise silver sulfadiazine, preferably in a concentration of between 0.5 and 1 percent (more preferably 0.75 percent). In still other related embodiments, a coating of a hydrophobic polymer may be applied over the treated article. Section 8, below, presents working examples of embodiments set forth in this paragraph.
[0024] In another particular non-limiting embodiment, the present invention provides for a hydrophobic polymeric medical article treated by dipping or soaking the article in a treatment solution of hydrophilic polymer comprising chlorhexidine and triclosan, wherein the chlorhexidine and triclosan are present in amounts such that their combination, in the treated article, has effective antimicrobial activity. In a specific, non-limiting embodiment, the medical article is a silicone catheter or Teflon graft which has been dipped or soaked in a treatment solution comprising (i) between about 1 and 10 percent, preferably between about 2 and 6 percent, and more preferably about 3 percent, of a biomedical polyurethane polymer; (ii) between 1 and 5 percent, and preferably between 1.5 and 2.25 percent, of chlorhexidine; and (iii) between 0.5 and 5 percent, and preferably between 0.5 and 2 percent, of triclosan. In related non-limiting embodiments of the invention, the treatment solution may further comprise silver sulfadiazine, preferably in a concentration of between 0.5 and 1 percent (more preferably 0.75 percent).
[0025] Medical articles prepared according to the invention may be treated on their external surface, internal surface, or both. For example, and not by way of limitation, where the medical article is a catheter, the internal surface and/or external surface of the catheter may be treated according to the invention. For example, where it is desired to treat both internal and external surfaces, an open-ended catheter may be placed in a treatment solution such that the treatment solution fills the catheter lumen. If only the external surface is to come in contact with treatment solution, the ends of the catheter may be sealed before it is placed in the treatment solution. If only the internal surface is to come in contact with treatment solution, the solution may be allowed to pass through and fill the lumen but the catheter is not immersed in the treatment solution.
[0026] Successful treatment of a medical article with a polymer comprising an anti-infective agent may be problematic, particularly where the medical article has a hydrophobic surface. The adherence of the polymer may depend upon (1) the polymeric matrix in which the anti-infective agent is suspended; (2) compatibility (or lack thereof) between the agent-polymeric matrix and the surface of the article; (3) the solvent system; and (4) the thickness of polymer/anti-infective agent desirably applied. Furthermore, the rates of release of various anti-infective agents from diverse polymers may differ. For example, the rate of release of chlorhexidine from a silicone matrix is faster than the rate of release of silver sulfadiazine from the same matrix. In order to compensate for this difference, one potential solution would be to increase the amounts of chlorhexidine and silver sulfadiazine in the matrix. Unfortunately, polymers comprising high levels of chlorhexidine and silver sulfadiazine have been found to adhere poorly to silicone catheters. In order to provide an alternative solution to the problem, two different methods for treating medical articles have been developed: a one-step method, and a two-step method, both of which are set forth below.
[0027] According to the one-step method of the invention, a polymeric medical article may be treated with a solution comprising one or more anti-infective agents, and optionally containing a biomedical polymer, dissolved in one or more solvent(s), wherein the solvent(s) selected are capable of swelling the polymeric medical article to be treated; such a solution is referred to herein as an “impregnating solution”, and the process by which the article is treated with anti-infective agent is referred to as “impregnation”. Suitable solvents include, but are not limited to, tetrahydrofuran (“THF”), dichloromethane, carbon tetrachloride, methanol, ethanol, methyl ethyl ketone, heptane, and hexane, and mixtures thereof. The biomedical polymer may be hydrophilic or hydrophobic, and includes the various polymers set forth above.
[0028] If a hydrophilic polymeric medical article is to be impregnated with chlorhexidine and triclosan, the impregnating solution may, in specific non-limiting embodiments, comprise the following (percentages of solvents in this paragraph being volume/volume): (1) 95% ethanol; (2) 70% ethanol/30% water; (3) 50% ethanol/50% water; (4) 30% reagent alcohol/70% THF containing 2-3% of a biomedical polyurethane; (5) 90% reagent alcohol/10% THF; or (6) 100% reagent alcohol. Preferred soaking times vary between 5 minutes and 1 hour.
[0029] In specific, non-limiting embodiments of the invention, a hydrophilic medical article such as a polyurethane catheter may be impregnated using a solvent mixture of 70-90% ethanol and 10-30% water and chlorhexidine and triclosan for between 10 and 60 minutes. The article may then be dried for 24-48 hours.
[0030] If a hydrophobic polymeric medical article is to be impregnated with chlorhexidine and triclosan, the impregnating solution may, in specific non-limiting embodiments, comprise the following percentages of solvents in this paragraph being volume/volume): (1) 10% methanol /90% THF; (2) 10% ethanol/90% THF; (3) 30% methanol/70% THF; (4) 30% ethanol/70% THF; (5) 1-5 percent silicone polymer in 10% methanol/90% THF; (6) 1-5 percent silicone polymer in 10% ethanol/90% THF; (7) 1-2 percent polylactic acid in 10% methanol/90% THF; (8) 1-2 percent polylactic acid in 10% ethanol/90% THE; (9) 1-5 percent silicone polymer in 30% methanol/70% THF; (10) 1-5 percent silicone polymer in 30% ethanol/70% THF; (11) 1-2 percent polylactic acid in 30% methanol/70% THF; (12) 1-2 percent polylactic acid in 30% ethanol/70% THF; (13) 1-5 percent silicone polymer in 100% methyl ethyl ketone; and (14) 1-2 percent polyurethane in 30% ethanol/70% THF. For specific examples, see Section 15, below.
[0031] In specific embodiments, the impregnating solution comprises between 0.2 and 10 percent anti-infective agent and between 0.5 and 4 percent biomedical polymer.
[0032] The medical article, or a portion thereof, may be immersed in the impregnating solution to swell, after which the article may be removed and dried at room temperature until all solvent has evaporated and the article is no longer swollen. During the swelling process, anti-infective agent (and small amounts of polymer when present in the impregnating solution) may be distributed within the polymeric substrate of the article; during drying, the anti-infective agent and biomedical polymer (where present) may migrate somewhat toward the surface of the article. After drying, the article may be rinsed in either water or alcohol and wiped to remove any excess anti-infective agent and/or polymer at the surface. This may leave a sufficient amount of anti-infective agent just below the surface of the article, thereby permitting sustained release of the agent over a prolonged period of time. Anti-infective agents which may be incorporated by this process include but are not limited to chlorhexidine, triclosan, silver sulfadiazine, parachlorometaxylene, benzalkonium chloride, bacitracin, polymyxin, miconasole and rifampicin, as well as combinations thereof.
[0033] In preferred, non-limiting embodiments of the invention, synergistic combinations of chlorhexidine and triclosan may be dissolved in a mixture of methanol and tetrahydrofuran to produce an impregnating solution that may be used to render a silicone catheter anti-infective.
[0034] In one specific, non-limiting example, the amount of chlorhexidine may be between 1 and 5 percent and preferably between 1.5 and 2.25 percent of the impregnating solution, and the amount of triclosan may be between 0.5 and 5 percent, and preferably between 0.5 and 2 percent. The resulting impregnating solution may further contain between 1 and 10 percent and preferably between 2 and 4 percent of a biomedical polymer such as a silicone polymer (e.g., Silastic Type A), polyurethane, or polycaprolactone. Specific examples of the one-step method are provided in Section 12 below.
[0035] According to the two-step method of the invention, the one-step method may be used to impregnate a medical article with anti-infective agent, and then the medical article may be dipped into a polymeric solution and dried. This method forms a polymeric coating on the article and further controls the rate of release of anti-infective agent. When the two-step method is practiced, the biomedical polymer may be omitted from the first soaking step. Optionally, an anti-infective agent may further be comprised in the polymeric coating. In a specific, non-limiting example, a silicone catheter may be dipped in a mixture of methanol and tetrahydrofuran containing between about 1 and 5 percent, and preferably between 1.5 and 2.25 percent, of chlorhexidine; between 0.5 and 5 percent and preferably between 0.5 and 2 percent of triclosan; and between 1 and 10 percent, and preferably between 2 and 4 percent, of a biomedical polymer (preferably a silicone polymer such as Silastic Type A) for about 30 minutes, dried, and then dipped in a higher concentration (but less than 10 percent) of biomedical polymer dissolved in a suitable solvent. For example, but not by way of limitation, a coating may be applied using a solution of 30% ethanol/70% THF containing 2-3 percent of a biomedical polyurethane, or a solution of 1-5 percent of Silastic Type A.
[0036] Alternatively, a hydrophilic medical article, such as a polyurethane catheter, may be impregnated with one or more antimicrobial agents and then coated with a polymer.
[0037] Examples of the two-step method are set forth in Sections 8, 16 and 17 below.
[0038] As set forth in Section 17, below, it has further been discovered that when medical articles were treated with mixtures of chlorhexidine free base and triclosan, uptake of chlorhexidine and triclosan was enhanced, and the antimicrobial activity of such articles was improved. While not desiring to be bound to any particular theory, it is believed that chlorhexidine free base and triclosan form a complex with improved solubility. The foregoing effect was observed when chlorhexidine free base and triclosan were combined in a respective molar ratio of 1:2; according to the invention, chlorhexidine free base and triclosan maybe dissolved in a solvent or solvent system at chlorhexidine free base: triclosan molar ratios of 1:1 to 1:3. The total weight percent of chlorhexidine free base plus triclosan is between 1 and 10 percent. The chlorhexidine free base and triclosan may be dissolved in a solvent system comprising water, alcohol, or tetrahydrofuran, and mixtures thereof, to produce an impregnating solution. In one specific, non-limiting example of the invention, a 1:2 ratio of chlorhexidine free base and triclosan may be dissolved in a solvent system which is 70 percent tetrahydrofuran and 30 percent reagent alcohol. A medical article, for example, a polyurethane article, may be impregnated with chlorhexidine free base/triclosan by immersing the article in such an impregnating solution so that the medical article swells without losing substantial structural integrity. After impregnation, the article may be dried, and then optionally coated with a polymeric solution, according to the two-step method set forth above.
[0039] Anti-infective medical articles prepared by other methods (e.g., extrusion, casting) but being otherwise substantially the same as articles produced by dipping or soaking, are within the scope of the claimed invention. 5. EXAMPLE: COMBINATIONS OF CHLORHEXIDINE AND TRICLOSAN EXHIBIT SYNERGISTIC ACTIVITY IN BACTERIAL CULTURES
[0040] Various concentrations of chlorhexidine diacetate (“CHA”) and/or triclosan (“TC”) were dispensed in 1.0 ml trypticase soy broth (“TSB”) containing 20 percent bovine calf serum (“BCS”) and inoculated with 10 7 colony-forming units (“CFU”) of Staphylococcus aureus. After one minute, the cultures were diluted with drug-inactivating medium (1:100 dilution in LTSB drug inactivating medium, which is 5% Tween 80, 2% lecithin, 0.6% sodium oleate, 0.5% sodium thiosulfate, 0.1% protease peptone and 0.1% tryptone) and 0.2 ml of the diluted culture was subcultured on a trypticase soy agar plate for the determination of colony counts. The results, shown in Table I, demonstrate the synergistic activity of combinations of chlorhexidine and triclosan. For example, whereas 500 micrograms per milliliter of CHA causes an approximately 17-fold decrease in CFU, and 500 micrograms per milliliter of triclosan causes an approximately 2400-fold decrease, the combination of these agents is associated with zero CFU, an at least 1×10 7 -fold decrease.
TABLE I (Anti-infective CFU/ml Agent kill) Concentration (μg/ml) (1 minute) CHA 2000 2.1 × 10 3 CHA 1000 5.0 × 10 4 CHA 500 6.0 × 10 5 TC 500 4.2 × 10 3 TC 250 2.0 × 10 5 CHA + TC 2000 + 500 0 CHA + TC 2000 + 250 0 CHA + TC 1000 + 250 0 CHA + TC 500 + 500 0 CONTROL 1.0 × 10 7
[0041] 6. EXAMPLE: COMBINATIONS OF CHLORHEXIDINE AND TRICLOSAN ARE MORE EFFECTIVE THAN COMBINATIONS OF CHLORHEXIDINE AND SILVER SULFADIAZINE WHEN APPLIED TO HYDROPHILIC CATHETERS
[0042] Polyurethane central venous catheters fabricated Of Tecoflex 93-A polyurethane were dipped in solutions containing 3 percent of a biomedical poly-urethane (Tecoflex 93-A; “PU”) and CHA, TC and/or silver sulfadiazine (“AgSD”) dissolved in 30 percent ethanol and 70 percent tetrahydrofuran (“THF”) (v/v) and air-dried. Bacterial adherence on these catheters was measured as follows. A 2 cm segment of dipped catheter was suspended in 3 ml TSB containing 10 percent BCS and incubated in a water bath shaker at 37° C. The media was changed daily. After 2 days the catheter segments were removed and transferred to fresh media containing 10 6 CFU/ml of Staphylococcus aureus and incubated for 24 hours. The segments were removed, rinsed with saline, and then suspended in LTSB drug-inactivating medium and sonicated for 20 minutes to remove the adherent bacteria. Aliquots from the LTSB extract were then subcultured on trypticase soy agar plates to determine colony counts. The results are presented in Table II, and demonstrate that combinations of CHA and TC are superior in preventing bacterial adherence when compared with CHA alone or in combination with AgSD.
TABLE II Adherent Bacteria Coating (CFU/ml) 3% PU + 2.5% CHA 5 × 10 4 3% PU + 1.5% CHA + 0.75% AgSD 2 × 10 4 3% PU + 1.5% CHA + 1% TC 5 3% PU + 1.5% CHA + 0.75% AgSD + 1% TC 40
[0043] In additional experiments, additional segments of the same type of polyurethane catheters coated with CHA, TC and/or AgSD were tested for the ability to produce zones of inhibition in trypticase soy agar plates seeded with 0.3 ml of 106 CFU of Staphylococcus aureus, Enterobacter cloacae, Candida albicans, and Pseudomonas aeruginosa. The coated catheter segments were placed vertically on the seeded plates, which were then incubated for 24 hours at 37° C. before the zones of inhibition were measured. The results, shown in Table III, demonstrate the superior effectiveness of mixtures of chlorhexidine and triclosan.
TABLE III Zone of Inhibition (mm) Coating*: Organism A B C D S. aureus 14.5 15.0 13.0 16.5 E. cloacae 9.0 12.0 7.5 3.0 C. albicans 12.0 12.0 11.5 0 P. aeruginosa 12.5 12.5 12.0 0
[0044] 7. EXAMPLE: HYDROPHILIC CATHETERS COATED WITH HYDROPHOBIC POLYMER COMPRISING CHLORHEXIDINE AND TRICLOSAN HAVE ANTIMICROBIAL ACTIVITY
[0045] The antimicrobial effectiveness of polyurethane central venous catheters (fabricated from Tecoflex 93-A polyurethane) coated with chlorhexidine diacetate and either triclosan or silver sulfadiazine in two polymeric coatings of differing water absorption were tested. The polymeric coatings, applied as set forth in Section 6 above, comprised either polyurethane 93A (“PU 93A”), a hydrophilic polyurethane having a water absorption of about 1-2 percent or polyurethane-silicone interpenetrating polymer (“PTUE 205”), a hydro-phobic silicone-polyurethane copolymer having a water absorption of only 0.4%. Antibacterial activity was measured by zones of inhibition, using methods as set forth in Section 6, above. The results, as regards antibacterial activity toward Staphylococcus aureus, Enterobacter cloacae, and Candida albicans at days 1 and 3 of culture, are shown in Tables IV, V, and VI, respectively, and demonstrate that combinations of chlorhexidine diacetate and triclosan were effective when comprised in hydrophilic (PU 93A) as well as hydrophobic (PTUE 205) coatings.
TABLE IV Antibacterial Activity Against S. aureus Zone of Inhibition (mm) Coating Day 1 Day 3 3% PTUE 205 + 16.0 11.0 1.5% CHA + 1.5% TC 3% PTUE 205 14.5 11.0 2% CHA + 0.75% AgSD 3% PU 93A + 16.0 11.5 1.5% CHA + 1.5% TC 3% PU 93A + 14.5 11.0 2% CHA + 0.75% AgSD
[0046] [0046] TABLE V Antibacterial Activity Against E. cloacae Zone of Inhibition (mm) Coating Day 1 Day 3 3% PTUE 205 + 12.0 6.0 1.5% CHA + 1.5% TC 3% PTUE 205 8.5 0 2% CHA + 0.75% AgSD 3% PU 93A + 11.0 7.0 1.5% CHA + 1.5% TC 3% PU 93A + 7.0 0 2% CHA + 0.75% AgSD
[0047] [0047] TABLE VI Antibacterial Activity Against C. albicans Zone of Inhibition (mm) Coating Day 1 Day 3 3% PTUE 205 + 11.0 7.0 1.5% CHA + 1.5% TC 3% PTUE 205 + 12.0 9.5 2% CHA + 0.75% AgSD 3% PU 93A + 12.5 7.0 1.5% CHA + 1.5% TC 3% PU 93A + 10.0 6.5 2% CHA + 0.75% AgSD
[0048] 8. EXAMPLE: HYDROPHOBIC CATHETERS TREATED WITH HYDROPHOBIC POLYMER COMPRISING CHLORHEXIDINE AND TRICLOSAN HAVE ANTIMICROBIAL ACTIVITY
[0049] Silicone central venous catheters fabricated from Dow Coming Q7-4765A silicone polymer or Q7-4765B silicone polymer were used to determine the effectiveness of impregnation with hydrophobic polymers comprising chlorhexidine diacetate and triclosan on hydrophobic substrates. The silicone catheters were soaked for about 30 minutes in a solution of 5 percent methanol and 95 percent THF (v/v) comprising (i) 2 percent medical adhesive Silastic Type A and (ii) chlorhexidine diacetate and either triclosan or silver sulfadiazine. The dipped catheters were dried and then dipped in a solution of 5 percent methanol and 95 percent THF (v/v) containing 5 percent Silastic Type A (“Si1A”), and dried again. The catheter segments were then tested for the production of zones of inhibition on trypticase soy agar plates inoculated with S. aureus or E. cloacae. The results are presented in Table VII.
TABLE VII Zone of Inhibition (mm) Treatment S. aureus E. cloacae 2% SilA + 1.5% CHA + >50 21 0.5% TC, then 5% SilA 2% SilA + 1.5% CHA + 17 15 0.5% AgSD, then 5% SilA
[0050] 9. EXAMPLE: TRICLOSAN EXHIBITS PROLONGED RELEASE FROM POLYMER COATINGS
[0051] Silicone central venous catheters fabricated from Dow Coming Q7-4765A silicone polymer or Q7-4765B silicone polymer were treated as set forth in Section 8, above, and then, immediately after drying, were extracted in dichloromethane/methanol/water (50%/25%/25%, v/v) in order to determine the amount of agent contained in the catheter segment tested (i.e., the uptake). To determine the rate of drug release, catheter segments were suspended in saline and incubated at 37° C. for up to seven days; the saline was collected and replaced with fresh saline on the first day and every 48 hours thereafter, and the amount of drug present in the collected saline was measured. The results are presented in Table VIII.
TABLE VIII Uptake Release (μg/cm) Treatment (μg/cm) Day 1 Day 3 Day 5 Day 7 2% SilA + 60 28.0 4.1 3.1 2.6 2% CHA, then 5% SilA 2% SilA + 1168 10.0 9.5 11.1 11.4 2% TC, then 5% SilA
[0052] Silicone catheters impregnated with Silastic Type A comprising either 2% triclosan or 2% chlorhexidine diacetate were then tested for the ability to produce zones of inhibition on trypticase soy agar plates inoculated with S. aureus, E. cloacae, C. albicans, or P. aeruginosa. The results of these experiments are shown in Table IX, and demonstrate that when higher concentrations of triclosan or chlorhexidine diacetate alone were used, triclosan-treated catheters were found to be equally or more effective than CHA-treated catheters.
TABLE IX Zones of Inhibition (mm) Treatments: 2% SilA + 2% CHA, 2% SilA + 2% TC, then 5% SilA then 5% SilA Organism Day 1 Day 3 Day 1 Day 3 S. aureus 17.5 16.0 >50 >50 E. cloacae 15.0 9.0 40.0 40.0 C. albicans 13.5 6.0 13.0 13.0 P. aeruginosa 13.0 0 8.5 0
[0053] 10. EXAMPLE: UPTAKE OF CHLORHEXIDINE AND TRICLOSAN IN PTFE GRAFTS
[0054] Arterial grafts fabricated from polytetrafluoroethylene (“PTFE”) were cut into segments and impregnated with Silastic Type A comprising chlorhexidine diacetate or triclosan in 30% methanol/70% THF (v/v), in proportions set forth below. The treated grafts were then extracted with dichloromethane/methanol/water (50%/25%/25%, v/v), and the amounts of solubilized anti-infective agents were determined. Table X shows the uptake of agent by the treated grafts.
TABLE X Treatment Agent Uptake (μg/cm) 2% SilA + 2% CHA 895 2% SilA + 2% TC 2435
[0055] 11. EXAMPLE: ANTIMICROBIAL EFFECTIVENESS OF MEDICAL ARTICLES FABRICATED FROM TEFLON, DACRON OR NATURAL RUBBER LATEX AND IMPREGNATED WITH COMBINATIONS OF CHLORHEXIDINE AND TRICLOSAN
[0056] Chlorhexidine diacetate and either triclosan or silver sulfadiazine, in proportions set forth below, were dissolved in 5% methanol/95% THF (v/v). Segments of Dacron grafts, PTFE grafts, and natural rubber latex urinary catheters were then soaked in the resulting solutions for 15 minutes to impregnate the segments with anti-infective agents. This procedure allows the polymer substrates of the devices to incorporate anti-infective agent. The segments were then removed from the soaking solution, dried, rinsed with water, and wiped. The ability of the treated segments to produce zones of inhibition on trypticase soy agar plates inoculated with S. aureus and E. cloacae was then tested. The results, shown in Tables XI-XIII, demonstrate that the combination of chlorhexidine and triclosan produced superior antimicrobial results compared to the combination of chlorhexidine and silver sulfadiazine.
TABLE XI PTFE Graft Zone of Inhibition (mm) Impregnating Solution S. aureus E. cloacae 5% CHA + 0.5% TC 37.0 22.0 1.5 CHA + 0.75% AgSD 22.0 16.5
[0057] [0057] TABLE XII Dacron Graft Zone of Inhibition (mm) Impregnating Solution S. aureus E. cloacae 5% CHA + 0.5% TC >40 30.0 1.5 CHA + 0.75% AgSD 26.0 27.0
[0058] [0058] TABLE XIII Latex Catheter Zone of Inhibition (mm) Impregnating Solution S. aureus E. cloacae 5% CHA + 0.5% TC 26.0 20.0 1.5 CHA + 0.75% AgSD 18.0 12.0
[0059] 12. EXAMPLE: ANTIMICROBIAL EFFECTIVENESS OF SILICONE CATHETERS PREPARED BY A ONE-STEP IMPREGNATION METHOD
[0060] Silicone catheters, as used in Example 8, were prepared by a one-step impregnation method as follows. Segments of the silicone catheters were soaked for about 30 minutes in impregnating solutions of 90% THF/10% methanol (v/v) containing 2% Silastic Type A, chlorhexidine, and either silver sulfadiazine or triclosan. The segments were then dried, and tested for their ability to produce zones of inhibition (at one and three days) in trypticase soy agar plates inoculated with S. aureus, E. cloacae, C. albicans, and P. aeruginosa. The results, presented in Table XIV, demonstrate the effectiveness of chlorhexidine and triclosan-impregnated catheters.
TABLE XIV Zones of Inhibition (mm) Treatments: 2% SilA + 1.5% CHA, 2% SilA + 1.5% CHA, +0.5% TC +0.5% AgSD Organism Day 1 Day 3 Day 1 Day 3 S. aureus >40 39 17.5 13.5 E. cloacae 21 21 15 8 C. albicans 13.5 7 13.5 6 P. aeruginosa 13.5 6.5 13 0
[0061] Additional formulations of impregnating solutions were tested for their ability to render the same type of silicone catheter segments anti-infective against C. albicans, the microorganism which appeared to be inhibited only by relatively high amounts of anti-infective agent. The following impregnating solutions comprised chlorhexidine, triclosan and either Silastic Type A, polycaprolactone, or no polymer in a 5% methanol/95%THF solvent. Table XV shows that when both polymer and anti-infective agent were comprised in the impregnating solution, higher anti-infective activity was achieved.
TABLE XV Impregnating Solution Zone of Inhibition (mm) 4% SilA + 5% CHA + 1% TC 12.0 1% polycaprolactone + 5% CHA + 1% TC 12.0 No polymer, 5% CHA + 1% TC 6.5
[0062] 13. EXAMPLE: DIFFUSION OF ANTI-INFECTIVE AGENTS FROM MEDICAL ARTICLES TREATED WITH IMPREGNATING SOLUTIONS WITH AND WITHOUT POLYMER
[0063] The following impregnating solutions, “A” and “B”, were used to impregnate segments of Dacron and PTFE grafts. The treated grafts were then rinsed with saline, and the amounts of anti-infective agent incorporated into the grafts were determined, before and after rinsing, by extraction of anti-infective agent with dichloromethane/methanol/water (50%/25%/25%, v/v). The results, set forth in Table XVI, demonstrate that the addition of a polymer to the impregnating solution produces a treated medical article which exhibits greater retention of anti-infective agent.
Solution A: 1% polycaprolactone + 0.1% CHA + 0.02% TC, in 5% methanol/95% THF (v/v) Solution B: 0.1% CHA + 0.02% TC, in 5% methanol/95% THF (v/v)
[0064] [0064] TABLE XVI Drug Levels (μg/cm) Dacron Graft PTFE Graft Solution: A B A B Solution A Before rinsing 392 548 73 90 After rinsing 353 547 56 88 Solution B Before Rinsing 409 573 50 44 After Rinsing 132 553 24 44
[0065] 14. EXAMPLE: DRUG UPTAKE AND RELEASE BY HYDROPHILIC CATHETERS IMPREGNATED WITH CHLORHEXIDINE OR TRICLOSAN
[0066] Polyurethane central venous catheter segments fabricated of Tecoflex 93-A polyurethane were impregnated with solutions “C”, “D”, “E”, “F” and “G” set forth below by soaking the catheter segments for about two minutes followed by drying and rinsing with water. Drug uptake was measured by extracting the impregnated catheter segments with dichloromethane/methanol/water (50%/25%/25% v/v). Drug release was measured over a period of six days by suspending the catheter segments in saline (one 2 cm segment in 2 ml saline), and agitated in a heated water bath at 37° C.; the saline was changed daily and drug release was measured as described above. The results are shown in Table XVII. Polyurethane, as set forth below, is Tecoflex 93-A polyurethane.
Solution C: 3% polyurethane + 3% CHA in 30% reagent alcohol/70% THF Solution D: 3% polyurethane + 3% TC in 30% reagent alcohol/70% THF Solution E: 3% polyurethane + 2% CHA + 2% TC, in 30% reagent alcohol/70% THF Solution F: 2% CHA in 95% ethanol Solution G: 3% CHA + 1% TC in 95% ethanol
[0067] [0067] TABLE XVII Drug Release (μg/cm) Uptake Day No. Solution Drug (μg/cm) 1 2 3 4 5 6 C CHA 197 78 36 20 2.6 0.8 0.8 D TC 300 0.4 .13 0.1 0.1 0.1 0.1 E CHA 202 66 16.8 7.0 5.0 5.0 5.0 TC 230 0.4 0.3 <.1 <.1 <.1 <.1 F CHA 254 15 9.6 7.8 2.5 2.5 2.5 G CHA 223 7.1 3.5 3.0 0.8 0.8 0.8 TC 368 <.1 <.1 <.1 <.1 <.1 <.1
[0068] 15. EXAMPLE: RELEASE OF CHLORHEXIDINE AND TRICLOSAN FROM IMPREGNATED SILICONE CATHETER SEGMENTS
[0069] Segments of silicone central venous catheters fabricated from Dow Corning Q7-4765A silicone polymer or Q7-4765B silicone polymer were impregnated with either solution H or I by soaking for 30 minutes, and then the release of drug was measured daily by methods set forth above. The results of these measurements are presented in Table XVIII.
Solution H: 2% SilA + 5% CHA in 10% methanol/90% THF (v/v) Solution I: 2% SilA + 5% CHA + 2% TC in 10% methanol/90% THF (v/v)
[0070] [0070] TABLE XVIII Daily Release (μg/cm) Solution Drug Day 1 Day 2 Day 3 Day 4 Day 5 H CHA 2.7 1.0 0.6 0.9 0.9 I CHA 0.8 0.9 0.6 0.8 0.8 TC 2.6 5.6 2.3 1.5 1.5
[0071] 16. METHOD OF RENDERING POLYURETHANE CATHETERS INFECTION-RESISTANT BY IMPREGNATION WITH A SYNERGISTIC COMBINATION OF CHLORHEXIDINE AND TRICLOSAN
[0072] A one-step method (“Method 1”) and a two-step method (“Method 2”) were used to treat polyurethane catheters.
[0073] Method 1: An entire polyurethane central venous catheter assembly including the hub, extension line and catheter body may be soaked in an alcoholic solution containing chlorhexidine and triclosan for a specific time period sufficient to impregnate these elements with chlorhexidine and triclosan without altering the integrity of the polyurethane substrate. The following solvent systems and soaking times are suitable. The concentrations of chlorhexidine and triclosan range from 0.5-5%.
TABLE XIX Solvent system Soaking time 95% ethanol/5% water 2-30 minutes 100% reagent alcohol 2-30 minutes 90% reagent alcohol/10% water 5-60 minutes 80% reagent alcohol/20% water 5-60 minutes 70% reagent alcohol/30% water 10-60 minutes 90% ethanol/10% water 5-60 minutes 80% ethanol/20% water 5-60 minutes 70% ethanol/30% water 10-60 minutes 20% methanol/10% isopropanol/ 10-60 minutes 40% reagent alcohol/ 30% water
[0074] Selection of the solvent mixture depends on the type of polyurethane substrate and antimicrobials used for impregnation. After soaking, the catheter is rinsed in water for 24 to 48 hours to allow the catheter to regain its original integrity and size.
[0075] Method 2. A catheter impregnated with chlorhexidine and triclosan according to Method 1 is then dipped in 70% THF/30% reagent alcohol/ 1-3% polyurethane/ 1-3% chlorhexidine/ 1-3% triclosan.
[0076] Catheters prepared by Method 1 provide a relatively slow and steady release rate from the luminal surface and outer surface for a prolonged period of time. This pattern of drug release results from the relatively lower ratio of drug to polyurethane matrix (0.015).
[0077] Catheters prepared by Method 2 exhibit biphasic drug release. The higher ratio of drug to polyurethane in the outer coating (1.3) permits an initial release of large amounts of drugs (which may inactivate bacteria entering through the skin at the time of insertion) followed by slow and steady release of drug impregnated in the catheter by Method 1. The outer polyurethane coating acts as a barrier and permits the controlled release of drug over a prolonged period of time.
[0078] As specific examples, Tecoflex polyurethane catheters were prepared using the following method and then tested for antimicrobial efficacy in their luminal and outer surfaces:
[0079] i) catheters were soaked in 2% chlorhexidine dissolved in 100% reagent grade alcohol for 1 hour, rinsed in water, and dried for 24-48 hours (“Catheter C”);
[0080] ii) catheters were soaked in 2% chlorhexidine+2% triclosan dissolved in 100% reagent grade alcohol for 15 minutes, rinsed in water, and dried for 24-48 hours (“Catheter TC”);
[0081] iii) catheters were soaked in 2% triclosan in 70% reagent alcohol/30% water for 2 minutes, rinsed in water, and dried for 24-48 hours (“Catheter T”);
[0082] iv) catheter C (above) was dipped in 3% polyurethane+2% chlorhexidine dissolved in 70% THF/30% reagent alcohol (“Catheter C-C”);
[0083] v) catheter C (above) was dipped in 3% polyurethane+2% chlorhexidine+0.75% AgSD dissolved in 70% THF/30% reagent alcohol (“Catheter C-A”); vi) catheter T (above) was dipped in 2% chlorhexidine+2% triclosan dissolved in 70% THF/30% reagent alcohol (“Catheter T-R”);
[0084] vii) catheter TC (above) was dipped in 2% chlorhexidine+2% triclosan dissolved in 70% THF/30% reagent alcohol (“Catheter TC-R”); and
[0085] viii) catheter TC (above) was dipped in 2% chlorhexidine+0.75% AgSD dissolved in 70% THF/30% reagent alcohol.
[0086] Trypticase soy agar plates were seeded with 10 5 CFU Staphylococcus aureus/ ml and 0.5 cm segments of catheter were embedded vertically. The plates were then incubated for 24 hours at 37° C. and zones of inhibition were measured. The results are shown in Table XX.
TABLE XX Catheter type (mm) Zone of Inhibition Surface Lumen Outer C 15 15 T 21 21 TC 25 25 C-C 15 18 C-A 15 18 T-R 21 25 TC-R 23 26 TC-A 23 26
[0087] 17. METHOD OF RENDERING POLYURETHANE CATHETERS INFECTION-RESISTANT BY IMPREGNATION WITH A SYNERGISTIC COMBINATION OF CHLORHEXIDINE FREE BASE AND TRICLOSAN
[0088] It was further discovered that when catheters were coated using insoluble chlorhexidine free base and triclosan, a soluble chlorhexidine/triclosan complex was formed which improved the drug uptake and, therefore, the efficacy of the catheter.
[0089] Method 3: Catheters prepared by Method 1 (see Section 16) were dried for 24-72 hours and then their outer surfaces were dipped in a polyurethane solution (1-3% polyurethane dissolved in THF/alcohol). Catheters prepared by this method exhibited a large amount of drug release initially followed by a small but synergistically effective amount of drug release for a prolonged period of time.
[0090] Method 4: Followed the same procedure as Method 1, except that insoluble chlorhexidine free base (CHX) was solubilized with triclosan (1 molar CHX:2 molar triclosan ratio), which forms a complex with CHX. After soaking for 5-10 minutes the catheters were dried for 1-3 days and then the outer surface was dipped in either a polyurethane solution alone (1-3% polyurethane) or a solution of polyurethane containing CHX and triclosan (TC).
[0091] When relatively soluble chlorhexidine salts such as chlorhexidine acetate (CHA) were used to impregnate catheters, the release was undesirably rapid. We investigated the use of CHX as a substitute for CHA. CHX is not soluble is water or alcohol but, surprisingly, we found that when it was combined in a 1:2 molar ratio with triclosan, an alcohol soluble complex formed.
[0092] The uptake of chlorhexidine from a solution containing CHX-TC complex was greater than that obtained from a CHA-TC solution despite a higher CHA concentration in the soaking solution. Due to higher chlorhexidine levels and higher rate of chlorhexidine release from the substrate resulting from impregnation with CHX-TC complex, the infection resistance of the catheters was greater than those containing only CHA.
[0093] Method 5: Same as method 4 but the soaking and outer coating solutions also contained soluble chlorhexidine acetate.
[0094] As specific examples, the following experiments were performed using Tecoflex catheters:
[0095] (1) Catheters were prepared according to Method 3. Specifically, catheters were soaked in 5% CHA+1% TC dissolved in reagent alcohol for 10 minutes, dried for three days, and then the outer surface was dipped in 2.7% Tecoflex polyurethane dissolved in THF/reagent alcohol (70%/30%); the resulting catheters are referred to as type 1 , and the polyurethane/THF/reagent alcohol solution is referred to as Solution J.
[0096] (2) A second group of catheters was prepared as in (1), but instead of using Solution J for the outer coating, another solution was used: 0.5% CHX+0.5% TC+2.7% polyurethane dissolved in 70%TUF/30% reagent alcohol (“Solution K”). The resulting catheters are referred to as type 2 .
[0097] (3) Catheters were prepared using Method 5. Specifically, catheters were soaked in a solution containing 2% CHX+2% CHA+2% TC dissolved in reagent alcohol for 10 minutes, dried for 3 days and their outer surfaces were dipped in Solution J. The resulting catheters are referred to as type 3 .
[0098] (4) Catheters were prepared as in (3) but were dipped in Solution K to produce an outer coating. The resulting catheters are referred to as type 4 .
[0099] (5) Catheters were prepared according to Method 4. Specifically, catheters were soaked for 10 minutes in 3% CHX+3% TC in reagent alcohol, dried for 3 days, and outer surface coated in Solution J. The, resulting catheters are referred to as type 5 .
[0100] (6) Catheters were prepared as in (5) but outer surface coated with Solution K. The resulting catheters are referred to as type 6 .
[0101] (7) Catheters were prepared according to Method 3. Specifically, catheters were soaked in a solution containing 5% CHA+1% TC in reagent alcohol for 10 minutes, dried for 3 days and then outer surface coated using Solution J. The resulting catheters are referred to as type 7 .
[0102] (8) Catheters were prepared as in (7), except were outer surface coated with 2.7% polyurethane+3% CHA in 70% THF/30% reagent alcohol. The resulting catheters are referred to as type 8 .
[0103] Segments of catheter types 1 - 8 were placed vertically in inoculated trypticase soy agar plates inoculated with 108 CFU of Staphylococcus aureus per plate, and incubated for 24 hours. After measuring the zones of inhibition, the catheters were transferred daily to fresh culture plates (shown in Table XXI).
TABLE XXI Catheter type (mm) Day Zone of Inhibition 1 21 12.0 2 21 13.0 3 21 17.0 4 21 20.0 5 21 20.0 6 21 23.0 7 21 5.0 8 21 9.0
[0104] The amount of drug uptake per cm/catheter in catheters prepared using various soaking solutions was measured as set forth above.
TABLE XXII Drug Uptake/cm catheter Soaking Solution Chlorhexidine Triclosan 5% CHA 260-310 — 5% CHA + 2% TC 280-300 450-480 2% CHX + 2% TC + 2% CHA 480-520 300-370 3% CHX + 3% TC 550-660 600-700
[0105] The luminal adherence of bacteria was quantified in catheters impregnated with antimicrobials and then coated with a solution of 2.7 percent Tecoflex 93A and various antimicrobial agents. Bacterial adherence was measured as follows. 12 cm segments of test and control 7Fr catheters were each connected to an individual channel of a peristaltic pump via an extension line, hub, and injection cap. The hubs were inoculated initially and after 24 hours with 10 6 cfu of S. aureus which causes the extension line to become colonized thus acting as a continuous source of bacteria for seeding lumens. The lumens were continuously perfused at a rate of 20ml/hour with trypticase soy broth (TSB) diluted 1:10 with physiological saline over the course of 7 days. At the end of one week the catheter segments were disconnected and their outer surfaces disinfected with 70% ethanol. Each lumen was flushed with sterile TSB to remove non-adherent bacteria. Each catheter was then cut into 2 cm segments each of which is further divided into 2 mm subsegments and placed in tubes containing 4 ml of antiseptic inactivating broth (LTSB). The tubes were sonicated for 20 minutes at 4° C. to remove bacteria adhering to the lumens. To quantify the adherence, a 0.5 ml aliquot of the LTSB extract was subcultured on trypticase soy agar plates. The results are shown in Table XXIII.
TABLE XXIII DRUG IN BACTERIAL SOAKING SOLUTION DRUG IN ADHERENCE (cfu/cm) OUTER COATING IN LUMEN 5% CHA 3% CHA 3 × 10 4 5% CHA + 0.5% TC 2% CHA + 2% TC 3 × 10 2 2% CHX + 2% CHA + 2% CHA + 2% TC 0 2% TC 3% CHX + 3% TC 0.5% CHX + 0.5% TC 0 0 (control) 0 4 × 10 6 2% CHX + 2% CHA + no outer coating 5 2% TC
[0106] Various publications are cited herein, which are hereby incorporated by reference in their entireties.
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The present invention relates to polymeric medical articles comprising the anti-infective agents chlorhexidine and triclosan. It is based, at least in part, on the discovery that the synergistic relationship between these compounds permits the use of relatively low levels of both agents, and on the discovery that effective antimicrobial activity may be achieved when these compounds are comprised in either hydrophilic or hydrophobic polymers. It is also based on the discovery that chlorhexidine free base and triclosan, used together, are incorporated into polymeric medical articles more efficiently. Medical articles prepared according to the invention offer the advantage of preventing or inhibiting infection while avoiding undesirably high release of anti-infective agent, for example into the bloodstream of a subject.
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TECHNICAL FIELD
[0001] This invention relates to tools for cutting, and in particular to a mechanism for use in tools for cutting.
BACKGROUND ART
[0002] The following discussion of the background art is intended to facilitate an understanding of the present invention only. It should be appreciated that the discussion is not an acknowledgement or admission that any of the material referred to was part of the common general knowledge as at the priority date of the application.
[0003] This invention relates to a cutting apparatus and in particular without limiting the invention, to a cutting apparatus where one or more blades are caused to move in an orbit. Typically, each such blade moves in an orbit having a plane which lies substantially in the same plane as the plane of the blade. With this arrangement the blade will cut typically on a part of the orbit where the blade is urged toward the workpiece.
[0004] This invention is applicable to tools having one such blade, and also to tools having two juxtaposed blades are caused to move sequentially with teeth following orbital paths. The tools in which this invention is applicable are those described by the inventor in U.S. Pat. No. 5,456,011 filed Oct. 12, 1993, U.S. patent application Ser. No. 12/744,147 filed Nov. 24, 2008, and U.S. patent application Ser. No. 13/501,455 filed Oct. 12, 2010, the contents of all of which are incorporated by cross-reference. The tools of this type have two blades mounted juxtaposed, that is side by side, close together if not touching each other, and the blades orbits move 180° out of phase relative to each other.
[0005] The orbital paths may be elliptical, which is the case with the cutting tools disclosed in the above described patent cases.
[0006] The products described in these patent specifications have been marketed by the applicant under the trade mark “Allsaw”. These products have a pair of blades arranged side by side and driven by a cam mechanism mounted roughly in the centre of a con rod/blade assembly. A pivot point at the top of the con rod is restrained in one plane while the cam rotates in a circular orbit. The teeth of the blade being mounted roughly equidistant and opposite to the pivot point from the cam so that when the cam scribes a circular orbit, the teeth follow an elliptical orbit.
[0007] The above described cutting tools are effective in cutting soft to medium material such as some brick and mortar, but their efficiency rapidly deteriorates if they encounter hard mortar or hard bricks. As the hardness of material being cut increases, it also increases the reaction of the cutting tool to the user, such that with very hard mortar or bricks it begins to bounce, rendering it impractical to use. With very hard material such as concrete or hard rock, the carbide teeth used along the cutting edge of the blade are also prone to breaking off.
[0008] It is an object of the invention to provide an arrangement for a cutting tool that can overcome the abovementioned problem.
[0009] Throughout the specification unless the context requires otherwise, the word “comprise” or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.
SUMMARY OF INVENTION
[0010] In accordance with one aspect of the invention there is provided a cutting tool mechanism for a cutting tool having a blade; in said cutting tool, said blade being driven by a driving mechanism with an input coupling for transmission of rotary motion from a motor, and an output coupling to transmit resultant orbital, oscillatory or impact motion to said blade, wherein said cutting tool mechanism comprises located between said output coupling and said blade, a coupling selected from a slide coupling and/or a spring suspension coupling through which the motion of said output coupling is transmitted to said blade.
[0011] In accordance with a second aspect of the invention there is provided a cutting tool having a blade driven by a driving mechanism with an input coupling for transmission of rotary motion from a motor, and an output coupling to transmit resultant orbital, oscillatory or impact motion to said blade, wherein a coupling selected from a slide coupling and/or a spring suspension coupling is located between said output coupling and said blade, through which the motion of said output coupling is transmitted to said blade.
[0012] Preferably, said coupling has travel extending toward said blade.
[0013] Preferably, said coupling has linear travel extending toward said blade.
[0014] Preferably, said coupling has linear travel extending substantially in the same direction of the intended cut into the workpiece. This would typically be transverse to the surface of the workpiece, assuming a flat workpiece surface. In this manner, the coupling acts to set up a resonance between the output coupling and the blade, which has been found unexpectedly to enhance the cutting action.
[0015] Preferably the coupling includes a dampener to dampen movement along its travel.
[0016] Preferably the coupling is biased to a position along its travel.
[0017] Preferably, said coupling is a spring biased sliding coupling.
[0018] In one arrangement the coupling may have a unidirectional bias, to urge the blade toward the workpiece, so that the coupling absorbs jarring impact forces from the blade; however, in the most preferred form the coupling has a bidirectional bias, so that the coupling suspends the blade from the output coupling.
[0019] A coupling with a unidirectional bias may use a single compression coil spring to bias the blade toward the cut and provide some shock absorbing. With a unidirectional bias it may require a resilient buffer located between parts at the extremes of travel of said coupling, in order to absorb impact forces to increase the life of the components in the coupling, if not to minimise noise.
[0020] A coupling with a bidirectional bias may use a single compression coil spring or two compression springs to bias the blade to a central position along the extent of travel of the spring suspension coupling. This arrangement urges the blade of the cutting tool toward the cut, and provides some shock absorbing, and also stores and releases energy where resistance encountered by the blade is overcome, and also assists to avoid the coupling slamming to the end of its travel.
[0021] Alternatively, the coupling with a bidirectional bias may use a flat spring which undergoes flexure when subject to deflection from the central position.
[0022] However in the most preferred arrangement, the coupling uses at least one flat spring to suspend said blade from said output coupling toward a central position along the extent of travel of the coupling. The output coupling operates in a reciprocating manner, and the blade may bounce, suspended by the flat spring(s).
[0023] Preferably the orbital, oscillatory or impact motion of the blade is elliptical with its long axis extending substantially in the direction that the cutting edge or teeth of the blade extend, and the travel of the coupling extending linearly in a direction extending across the long axis.
[0024] Preferably the orbital, oscillatory or impact motion of the blade is elliptical with its short axis extending substantially in the direction of the linear travel of the coupling.
[0025] In either arrangement of unidirectional bias or bidirectional bias, preferably the maximum extent of travel in the coupling is less than the oscillatory excursion of the output coupling in the same direction of travel as the coupling.
[0026] Preferably the compression spring strength is selected so that at maximum no-load operating speed of the cutting tool, when the compression spring is under compression, the coupling will not reach the end of its travel.
[0027] Alternatively the compression spring strength is selected so that at maximum no-load operating speed of the cutting tool, when the compression spring is under compression, the coupling will just reach the end of its travel, but not impact with the end of its travel.
[0028] As a further alternative, preferably the compression spring strength is selected so that at maximum no-load operating speed of the cutting tool, when the compression spring is under compression, the coupling will reach the end of its travel, and resilient compressible buffers are provided in said coupling to absorb any impact forces imparted at the end of the travel.
[0029] In practice the selected spring strength is determined by a number of factors. For maximum efficiency and effectiveness of the cutting tool, the springs should compress to the maximum extent at no load full operational speed. Due to various factors such as variation in maximum motor speed between motors, and the effect of blades having different weights, it may be desirable to allow the coupling to reach the end of its travel at maximum no-load operating speed of the cutting tool, in which case resiliently flexible stops should be incorporated into the couplings in order to prevent premature failure.
[0030] Preferably the blade is mounted to a mounting portion extending from one end of the coupling, and the other end of the coupling extends to a pivot point to restrain movement from the output coupling.
[0031] Preferably the pivot point is provided by a resilient mount that allows motion in the substantial direction extending between the output coupling and the pivot point, while restraining motion in any other direction. The resilient mount may be formed by a strip of spring steel or the like that is flexible in the direction of movement of the coupling, but resists movement in other directions, and is inextendable under tension or compression.
[0032] Preferably the output coupling transmits a circular orbital motion to said coupling. The effect of the above described pivot action is to translate the circular orbital motion to an elongated elliptical motion at any point of the blade. The mechanism between the input coupling and the output coupling that achieves this is a crankshaft having its output coupling axis offset from the input coupling axis.
[0033] Preferably said coupling comprises said output coupling mounted for linear travel relative to a body, said output coupling being biased by at least one spring, and having a bearing for connecting to said crankshaft.
[0034] Preferably said coupling comprises said output coupling contained within a housing in said body, mounted for linear travel, and being biased by at least one spring member, and having a bearing for connecting to said crankshaft.
[0035] Preferably said output coupling is mounted for linear travel relative to said body on a bearing surface.
[0036] Preferably said bearing surface comprises a journal surface machined into said output coupling.
[0037] Preferably said linear travel bearing surface is provided by at least one aperture extending through said output coupling, each aperture co-operating with a pin which is secured to said mounting portion.
[0038] Preferably said output coupling is biased by a said spring located at each end to suspend said output coupling relative to said body, for substantially linear travel.
[0039] Any or each said at least one spring may comprise a flat spring which undergoes flexure when subject to deflection from its rest position. The flat spring may allow linear or arcuate movement but linear movement is preferred.
[0040] However in the most preferred arrangement, the coupling uses at least one flat spring to suspend said body (and hence said blade) from said output coupling. Preferably said at least one flat spring comprises a pair of springs. The pair of flat springs may be configured to restrain said coupling for linear or arcuate movement, but it is preferred that they restrain said coupling for linear movement, rather than arcuate movement.
[0041] Preferably body comprises a housing and said output coupling is suspended within said housing by a pair of flat springs.
[0042] Preferably said coupling comprises two flat springs, one located near or at opposite ends of said output coupling. Preferably these flat springs extend across the extent of travel of the output coupling, most preferably normal thereto.
[0043] Preferably the flat springs are secured at three locations therealong, being toward either end to secure to said body and being centrally located to secure to said output coupling. There may be securing apertures or a single aperture provided at each of the three locations.
[0044] Preferably the three locations are located substantially in-line.
[0045] While the springs are flat, preferably the flat springs have a flat body that between adjacent locations, deviates away from the line intersecting the three locations. This allows a component of torsion in the flat springs to be introduced through movement in the coupling. In addition, due to the two locations toward either end where the flat spring is secured to the body being fixed relative to each other, movement of the coupling will also place the flat springs under tension through the curvature in their body between adjacent apertures.
[0046] The flat springs may be visualised as being shaped approximately in a W or E or 3 shape with three apertures in-line located approximately near the end of each leg, at the three locations. W or E shaped configurations are not so preferred since the spring can fracture at the sharp corners.
[0047] Preferably between adjacent locations, the flat body deviates away from the line intersecting the three locations in a smoothly curving configuration. This smoothly curving structure avoids stresses that can occur at sharp corners.
[0048] By way of explanation, in a most preferred embodiment, the input coupling is a crankshaft which is driven by a rotary motor, the output coupling is a cam follower which does not rotate, but moves to and fro, and the body is suspended relative to the output coupling by spring members. The output coupling and the body together form a spring suspension coupling. A blade is attached depending from the body at one end of the spring suspension coupling. The body is restrained from rotating with the input coupling by the spring members and by a pivot point mount located opposed from the blade, depending from the body at the other end of the spring suspension coupling. As a result of the provision of the pivot point, the output coupling prescribes an elliptical path, and this movement is exaggerated at the blade cutting edge, which is located further from the pivot point. The location of ends of the spring suspension coupling, is determined by reference to the major direction of reciprocating motion, by the spring suspension coupling as restrained by the pivot point. The blade is preferably attached to the body at said one end by a mounting portion, which may include fasteners allowing quick release of the blade.
[0049] Preferably said resiliently flexible stops are provided by o-rings fitted on said pin or pins, located between said component and said mounting portion. The o-rings are compressed axially between the component and mounting portion, should the component reach the end of its linear travel within the mounting portion.
[0050] Preferably said driving mechanism has said input coupling for transmission of rotary motion from a motor, and said driving mechanism has a first said output coupling to transmit resultant orbital, oscillatory or impact motion to a first blade, wherein said cutting tool mechanism includes located between said first output coupling and said first blade, a first said coupling through which the motion of said output coupling is transmitted to said blade, and said driving mechanism has a second said output coupling to transmit resultant orbital, oscillatory or impact motion to a second blade, wherein said cutting tool mechanism includes located between said second output coupling and said second blade a second coupling through which the motion of said second output coupling is transmitted to said second blade.
[0051] Preferably the first output coupling and the second output coupling are mounted about axes located opposite the axis of the input coupling.
[0052] Also in accordance with the present invention, there is provided a cutting tool incorporating two cutting tool mechanisms as described above, located side by side, wherein the input couplings of both said mechanisms comprise a common crankshaft having journals each connected for rotation with a cam follower to form the output coupling of each said cutting tool mechanism, where the journals of said crankshaft are out of phase.
[0053] Preferably the journals of said crankshaft are 180° out of phase.
[0054] While the coupling is described as a spring suspension coupling or a sliding coupling or a combination of both, in effect the coupling is a guided coupling which allows to and fro give between the output coupling and the blade, into the cut being made. Where in one embodiment, the flat springs guide the movement of the blade relative to the output coupling of the tool, in an alternative embodiment, as will be seen, the coupling has bearing surfaces to guide the movement of the blade relative to the output coupling of the tool. In such a coupling, coil springs provide the suspension, but not the guiding function. In a further embodiment, providing that there is some sort of slide coupling arrangement to provide the guidance, the springs could be dispensed with or replaced with rubber or other compressible material.
BRIEF DESCRIPTION OF DRAWINGS
[0055] Three preferred embodiments of the invention will now be described in the following description of power saws for cutting concrete, brick and the like, made with reference to the drawings in which:
[0056] FIG. 1 is a perspective view of an electrically operated hand held power saw according to the first embodiment;
[0057] FIG. 2 is an opposite side perspective view of the electrically operated power saw of FIG. 1 showing drive to the input coupling;
[0058] FIGS. 3 to 6 are side elevations showing the motion sequence of a blade and associated driving mechanism and spring suspension coupling;
[0059] FIG. 7 is a perspective view of a pair of blades of the power saw with their associated spring suspension couplings and driving mechanism;
[0060] FIG. 8 is a part exploded view of the parts shown in FIG. 7 ;
[0061] FIG. 9 is a view showing the path traced by the blade in the embodiment operating under no load at low speed;
[0062] FIG. 10 is a view showing the path traced by the blade in the embodiment operating under no load at high speed;
[0063] FIG. 11 is a view showing the path traced by the blade in the embodiment operating under load at high speed;
[0064] FIG. 12 is a perspective view of a plunge cut blade of a power saw of the second embodiment, with its associated spring suspension coupling and driving mechanism;
[0065] FIGS. 13 to 16 are a side view of showing the mechanism of an electrically operated power saw according to the third and most preferred embodiment;
[0066] FIG. 17 is a perspective view of the mechanism of FIGS. 13 to 16 ; and
[0067] FIG. 18 is an exploded perspective view of the mechanism of FIG. 17 ; and
[0068] FIG. 19 is a plan view of the flat springs used in the third embodiment.
DESCRIPTION OF EMBODIMENTS
[0069] The cutting tool 11 according to the first embodiment has a body 13 housing an electric motor, a handgrip portion 15 at the rear of the body 13 incorporating a control switch 17 with or without variable speed control for controlling the electric motor, a transmission case 19 at the front of the body 13 , a hand grip 21 atop the transmission case 19 , and a pair of blades 23 and 25 arranged side by side, extending from underneath the transmission case 19 . Whether the switch 17 incorporates a variable speed controller depends on the application of the tool. For most concrete cutting operations a constant speed is sufficient
[0070] The transmission case 19 houses a bevel reduction-gear assembly to translate the axis of rotary motion of the electric motor, and a reduction belt drive 27 leading to a large pulley 29 , together the bevel reduction-gear assembly and reduction belt drive 27 reduce the angular velocity of the electric motor (and multiply the torque). The reduction belt drive 27 and associated pulleys can be toothed, in order to prevent slippage, but a v-belt without toothed pulleys can be advantageous in applications where the blades might jam, in which circumstances the reduction drive belt would double as a clutch mechanism.
[0071] The large pulley 29 is directly connected to the driving mechanism 31 of the cutting tool 11 , in effect forming part of the input coupling 33 . The driving mechanism 31 has a crankshaft 35 having two journals 37 and 39 off-set from the central axis of the crankshaft by about 2 mm, and offset from each other by 180° relative to the central axis of the crankshaft 35 . The crankshaft 35 is supported for rotation on roller bearings 40 see FIG. 8 ).
[0072] The driving mechanism 31 has two output couplings formed by components in the cam followers 41 and 43 having cylindrical bearing surfaces 45 and 47 respectively that co-operate with journals 37 and 39 respectively (see FIGS. 7 and 8 ). It should be noted that in the part views shown in FIGS. 3 to 6 , the journal 37 has been omitted from the end view of the crankshaft 35 , while the end of the crankshaft 35 is shown to provide a reference point for journal 39 in the motion sequence illustrated in FIGS. 3 to 6 . The cam followers 41 and 43 each have linear travel bearing surfaces formed by apertures 49 extending through the cam followers that mate for sliding movement with bearing surfaces 50 on pins 51 that when assembled each extend through an aperture 49 , and contained within a housing 53 , each located in mounting portions in the form of connecting rod 55 and 57 .
[0073] The housing 53 in connecting rod 55 contains cam follower 41 for sliding vertical movement, and the housing 53 in connecting rod 57 contains cam follower 43 for sliding vertical movement. The pins 51 each receive resiliently flexible stops in the form of o-rings 58 over the exposed ends of the pins 51 connecting rods 55 and 57 , the o-rings 58 locating between the cam followers 41 , 43 and the connecting rods 55 , 57 respectively, to prevent metal to metal contact at the ends of the travel of the connecting rods 55 , 57 . The pins 51 are received in bushes 59 press-fit into the connecting rods 55 and 57 , at the top and bottom of the housing 53 .
[0074] Cam follower 41 is biased to a central position within the housing 53 in connecting rod 55 by an upper spring 60 and a lower spring 61 received in recesses 63 in the connecting rod 55 and circular recesses 65 in the cam follower 41 . Similarly cam follower 43 is biased to a central position within the housing 53 in connecting rod 57 by an upper spring 60 and a lower spring 61 received in recesses 63 in the connecting rod 55 and circular recesses 65 in the cam follower 41 . The assemblies of cam follower 41 and connecting rod 55 on the one hand and cam follower 43 and connecting rod 57 on the other hand, are mirror images of each other, but are otherwise identical.
[0075] The assembly of cam follower 41 co-operating with journal 37 forms one output coupling, while the assembly of cam follower 43 co-operating with journal 39 forms another output coupling.
[0076] The connecting rod 55 has a bevelled portion on its outside, below the housing 53 , to which blade 25 is affixed using in-hex machine screws 67 . Above the housing 53 , the connecting rod 55 extends via a connecting arm 69 to a pivot point provided at an in-hex machine screw mounting point 71 attaching to a strip of spring steel 73 which is bolted to the cutting tool 11 inside the transmission case. Similarly, the connecting rod 57 has a bevelled portion on its outside, below the housing 53 , to which blade 25 is affixed using in-hex machine screws 75 . Above the housing 53 , the connecting rod 57 extends via a connecting arm 69 to a pivot point provided at an in-hex machine screw mounting point 77 attaching to a strip of spring steel 79 which is also bolted to the cutting tool 11 inside the transmission case.
[0077] The arrangement of the pivot point 71 operates to fix the movement of the connecting rod 55 relative to the pivot points. With the strip of spring steel 73 being inextendible and incompressible, allowing only vertical movement in the direction extending between the central axis of the bearing surface 45 of the cam follower 41 and the pivot point 71 , the blade cutting tips 81 follow an elliptical path 83 , which at low motor speed is as shown in FIG. 9 .
[0078] The same applies for the arrangement of the pivot point 77 operating to fix the movement of the connecting rod 57 relative to the pivot points, with the strip of spring steel 79 allowing only vertical movement in the direction extending between the central axis of the bearing surface 47 of the cam follower 43 , causing the blade cutting tips 81 to follow an elliptical path 83 , which at low motor speed is as shown in FIG. 9 . The strips of spring steel 73 and 79 each have an aperture 84 to bolt the strips of spring steel 73 and 79 to the inside of the transmission case 19 .
[0079] The assembly of cam follower 41 co-operating with connecting rod 55 , and sprung with springs 59 and 61 form a biased slide/spring suspension coupling with bidirectional bias between the connecting rod 55 and blade 25 . Similarly, the assembly of cam follower 43 co-operating with connecting rod 57 , and sprung with springs 59 and 61 form a biased slide/spring suspension coupling with bidirectional bias between the connecting rod 57 and blade 23 .
[0080] The enhancement provided by the embodiment is that the cam now connects via the biased slide/spring suspension coupling that allows the blade/conrod assembly to move a defined distance in the same plane (vertical) as the pivot point, while not allowing any movement in the (horizontal) plane normal to the direction of movement allowed at the pivot point. In other words, where the cam is connected to the conrod/blade assembly, it is sprung so that inertia produced by the cam allows the conrod/blade assembly to move beyond the orbit in the vertical direction but is confined to the extent of the orbit in the horizontal plane.
[0081] Referring to FIG. 9 , the elliptical path 83 of the blade tooth orbit is shown at low motor speed. Due to the stiffness of the springs 59 and 61 , this path is more or less identical to the path of the applicant's prior art cutting tool, the original Allsaw.
[0082] However as speed increases when free running, the elliptical path of the blade tooth orbit changes under the effect of the biased sliding/spring suspension mechanism, causing the short axis of the ellipse to increase in length, allowing the teeth to move further outward in the vertical direction, and the shape of the ellipsis becomes skewed, but the elliptical path is constrained in the horizontal (long axis) direction. At maximum free running speed the elliptical path 85 will become more like that shown in FIG. 10 . This deviation from the elliptical path shown in FIG. 10 is facilitated by a combination of the inertia of the con rod assembly and robust springs which at low speeds would return the path of the teeth to the original elliptical path 93 shown in FIG. 9 . FIG. 9 represents the inner limit of the elliptical tooth path 83 and FIG. 10 represents the outer limit of any elliptical tooth path 85 .
[0083] If the teeth were brought into contact with any material while operating at full speed, the teeth would either penetrate the material or be allowed to deviate from its original path if the material is too hard to penetrate. The result is that when striking hard material, the reaction is very smooth. In such circumstances, the tooth path 87 has been observed and is shown in FIG. 11 .
[0084] Further, when striking brittle material such as rock or concrete, the sudden change in tooth path releases energy into the material causing a chip to be produced. The high frequency of this chipping action results in a smooth cutting action even in the harder materials.
[0085] The second embodiment illustrated in FIG. 12 is identical to the first embodiment except that there is a single blade 23 which is a plunge cut style blade intended for uses such as cutting recesses in brickwork for installing electrical back boxes for switches and power points, or cutting away mortar in order to replace damaged bricks in brickwork. In this second embodiment, the driving mechanism 31 has a single output coupling formed by cam follower 43 contained in housing 53 in connecting rod 57 . To counterbalance the weight of the offset journal 39 and its associated cam follower 43 , offset journal 37 is fitted with a further output coupling formed by cam follower 41 contained in housing 53 in connecting rod 55 to which is fixed a counterweight 89 , so the entire mechanism is balanced.
[0086] The third embodiment is illustrated in FIGS. 13 to 18 . Where like parts have the same form and function as the first embodiment, the same numbering will be used. The third embodiment has the same features of the cutting tool 11 according to the first embodiment shown in FIGS. 1 and 2 , having a body 13 housing an electric motor, a handgrip portion 15 at the rear of the body 13 incorporating a control switch 17 for controlling the electric motor, a transmission case 19 at the front of the body 13 , a hand grip 21 atop the transmission case 19 , and a pair of blades 23 and 25 arranged side by side, extending from underneath the transmission case 19 .
[0087] As in the first embodiment, referring to FIG. 2 , the transmission case 19 houses a bevel reduction-gear assembly partly shown as 26 , to translate the axis of rotary motion of the electric motor, and a reduction belt drive 27 leading from a small pulley 28 to a large pulley 29 , together the bevel reduction-gear assembly and reduction belt drive 27 reduce the angular velocity of the electric motor (and multiply the torque). The reduction belt drive 27 and associated pulleys 28 and 29 is a v-belt to allow slippage in the event of the blades 23 and 25 jamming. The small pulley 28 occludes the bevel gear on the shaft of the motor, the bevel gear on the shaft of the motor engaging with the larger bevel gear 26 .
[0088] The large pulley 29 is directly connected to the driving mechanism 31 of the cutting tool 11 , in effect forming part of the input coupling 33 . The driving mechanism 31 has a crankshaft 35 having two journals 37 and 39 off-set from the central axis of the crankshaft by about 2 mm, and offset from each other by 180° relative to the central axis of the crankshaft 35 .
[0089] The driving mechanism 31 has two output couplings formed by cam followers 141 and 143 having cylindrical bearings 145 and 147 respectively that co-operate with journals 37 and 39 respectively (see FIGS. 17 and 18 ). It should be noted that in the part views shown in FIGS. 13 to 17 , the journal 37 is hidden behind the left hand side blade and mechanism assembly, but can be seen in FIG. 18 . The cam followers 141 and 143 are each suspended from two flat springs 151 and 153 , one 151 located at the top of each cam follower 141 and 143 and the other 153 located at the bottom of each cam follower 141 and 143 .
[0090] The flat springs 151 and 153 are each secured through an aperture 155 located at a central location to their cam follower 141 143 by an in-hex machine screw 157 with a locking washer to prevent shaking loose during operation. The flat springs 151 and 153 are also each secured through apertures 161 and 163 located equidistant from the aperture 155 at either end of the flat springs 151 and 153 , by in-hex machine screws 165 and 167 with locking washers, to a body in the form of a housing 53 .
[0091] The cam followers 141 and 143 and their respective housings 53 are suspended relative to each other, and together form a biased spring suspension coupling, with the springs 151 and 153 both suspending these parts relative to each other and biasing them toward a central position which the housings 53 may oscillate either side of when the crankshaft 35 is rotated under operation. This arrangement differs from the first embodiment in that journal surfaces are not required for controlling the relative movement of the cam followers 141 and 143 and their respective housings 53 .
[0092] Pieces of 2 mm thick polyurethane foam rubber disc 168 located above the top screw 157 and below the bottom screw 157 cushion any impact of the screws 157 with proximal portions of the castings that form the housings 53 . These cushion any impact that otherwise might occur between the screws 157 and the housings 53 in the event that the coupling undergoes an excessive excursion.
[0093] Each housing 53 has a mounting portion 169 located underneath, also secured by screws 165 and 167 , each mounting portion 169 having a blade 23 or 25 secured thereto by an in-hex machine screw 171 which secures into a threaded aperture in a rectangular plate member 172 .
[0094] The rectangular plate member 172 is formed with sloping vertical edges. The blade is formed with a bifurcation at its top, leading to mounting fingers 173 which have opposed bevelled inner edges 174 . The opposed bevelled edges 174 of the blade match the sloping vertical edges of the rectangular plate member 172 in an interference fit when the in-hex machine screw 171 is tightened in the rectangular plate member 172 , to securely mount the blade. The mounting portions 169 are each formed with a machined recess to match the blade shape and securely flush mount the blade, providing security against the blade undergoing in-line torsion during operation. The arrangement of the in-hex machine screw 171 , the rectangular plate member 172 , and the mounting portion 169 , co-operating with the fingers 173 of the blade provides a quick release mechanism allowing simple blade changing with the release of the single screw 171 .
[0095] The housing 53 contains cam follower 141 , restrained by their springs 151 and 153 for linear vertical movement, and the other housing 53 contains cam follower 143 , restrained by their springs 151 and 153 for linear vertical movement. The assembly of cam follower 141 co-operating with journal 37 forms one output coupling, while the assembly of cam follower 143 co-operating with journal 39 forms another output coupling.
[0096] Above each housing 53 , a connecting arm 69 extends to a pivot point provided at an in-hex machine screw mounting point 71 . 77 attaching to a strip of spring steel 73 , 79 which are bolted through apertures 84 to mounting points in the cutting tool 11 inside the transmission case.
[0097] Each connecting arm 69 , body 53 and mounting portion 169 forms a connecting rod 55 , 57 extending between their respective pivot points which operate to fix the movements of the connecting rods 55 , 57 relative to their respective pivot points. With the strips of spring steel 73 , 79 being inextendible and incompressible, allowing only vertical movement in the direction extending between the central axes of the journals 37 , 39 and the pivot points of the respective assemblies, the blade cutting tips 81 of each blade follow an elliptical path 83 , but 180° out of phase with each other. This elliptical path, at low motor speed, is as shown in FIG. 9 .
[0098] The flat springs 151 and 153 have their apertures 161 , 155 and 163 located in-line and spaced evenly apart. The body 175 of the flat springs 151 , 153 that extends between adjacent apertures 161 and 155 and the body 177 of the flat springs 151 , 153 that extends between adjacent apertures 163 and 155 , both deviate from the straight line extending between the apertures 161 , 155 and 163 to take on planar curved forms in their configuration. This is largely to provide clearance from the housing 53 , but gives rise to an additional benefit in that when the flat springs 151 and 153 undergo deflection, there is a combination of effects that enhance their operation compared with a linear flat spring. These effects are greater effective length of the distances between adjacent apertures, torsion occurring between adjacent apertures 161 and 155 and between adjacent apertures 163 and 155 due to the curvature in the body portions 175 and 177 , and tension between adjacent apertures 161 and 155 and between adjacent apertures 163 and 155 on account of the distance between the adjacent apertures increasing. It should be understood that the deflection of the bodies relative to the cam followers as limited by the flat springs 151 and 153 is only about 1 mm in total.
[0099] In the tool according to all of the embodiments, the flat springs 73 , 79 , 151 and 153 are manufactured from 1.2 mm thick spring steel. The spring steel sheet from which the flat springs are manufactured may be between 1 mm and 2 mm, or can be thicker longer. The springs 60 and 61 are wound from 1.5 mm diameter spring steel wire. The crankshaft 35 and cam followers 141 and 143 are formed from 4140 steel alloy, while the remaining parts are cast from aluminium alloy.
[0100] It should be noted that for this particular type of cutting saw as described and illustrated in the embodiments, the amount of travel in the vertical (short axis) needs to be less that the orbit of the cam. In the case of the embodiment, the cam has a 2 mm offset creating a 4 mm orbit. Having less than 4 mm of travel causes the vertical (short axis) motion to synchronise with the orbit of the cam. If the sprung conrod assembly were allowed to travel further than the orbit of the cam, it will seek its natural frequency independent of the cam resulting in an uncontrolled or random tooth path which has proven to be not helpful to the cutting action.
[0101] One other aspect that needs to be understood is the contribution that the selection of the springs controlling the vertical or short axis makes to the cutting action.
[0102] When operated at running speed, the inertia of the conrod/blade assembly needs to be countered by springs of sufficient strength that they are fully compressed at both the top and bottom of the short axis. Ideally they fully compress but exactly resist the conrod assembly from slamming into the vertical (short axis) limits top and bottom. It has been unexpectedly found that the lag between the inertia of the conrod assembly and the rotation of the cam results in the spring releasing its energy as the spring expands thus adding extra velocity to the downward thrust of the blade, further improving the cutting efficiency of the action.
[0103] While the above described embodiment describes using two blades side by side to balance the action for heavy blades. In the prior art devices produced by the inventor and applicant, it was not possible to use a single blade because the reaction from a single blade is too violent to effect a suitable cutting action. With the new invention however, the spring suspension of the con rod/blade assembly allows a very smooth cutting action as the con rod/blade assembly is allowed to deviate from the elliptical path without forcing a reaction through the whole machine. It is thus now possible and often desirable to use just a single blade to effect a narrower cut.
[0104] The invention significantly improves the cutting action of this style of oscillatory power tool, showing a superior ability to cut harder materials such as stone and concrete. The biased spring suspension mechanism provides a smoother cutting action with less impact reaction through the tool, and provides better control. In addition the invention opens up the possibility of making a tool having the same cutting action but using a single blade only as opposed to two juxtaposed blades.
[0105] It should be appreciated that the scope of the invention is not limited to the specific embodiment disclosed herein, and that changes may be made without departing from the spirit and scope of the invention.
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A cutting tool mechanism and cutting tool ( 11 ) including the mechanism ( 31 ), for cutting hard material such as concrete and stone is disclosed. The tool ( 11 ) has one or two blades ( 23 ), ( 25 ) each driven by a mechanism ( 31 ). Each mechanism ( 31 ) has an input coupling 35 for transmission of rotary motion from a motor, and an output coupling ( 141 ), ( 143 ) to transmit resultant orbital, oscillatory or impact motion to the blade ( 23 ), ( 25 ). A suspension or sliding coupling located between the output coupling ( 141 ), ( 143 ) and the blade ( 23 ), ( 25 ), is provided, through which motion to the blades is transmitted. The suspension or sliding coupling absorbs impacts of the blades with the material being cut, rendering the tool more controllable.
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FIELD OF THE INVENTION
The present invention relates to a method of using VDSL zipper duplex transmission in an unsynchronised mode, a system employing VDSL zipper duplex transmission, in an unsynchronised mode, over a common twisted pair cable, a transmission system employing the method, a receiver for use with the transmission system, a transmitter for use with the transmission system and a modem, incorporating a receiver and transmitter, for use with the transmission system.
BACKGROUND OF THE INVENTION
In our co-pending patent application WO 9706619, there is described a procedure for suppressing near-end crosstalk (NEXT) when using duplex communication, in twisted pair wire networks, in which different subcarriers are used in the two transmission directions, and in which the subcarriers are orthogonal. Preferably a number of sub-carriers are transmitted in each transmission direction. Alternate sub-carriers are used in each direction. The number of sub-carriers used in one transmission direction may be greater than the number used in the other transmission direction.
In our co-pending patent application, referenced above, the use of Zipper VDSL with time synchronization is described. The present invention complements the earlier invention, in that it enables VDSL Zipper duplex transmission, as described in our co-pending patent application, without time synchronization between different modem pairs over the same twisted copper pair cable, i.e. in the same binder group.
Zipper is a time-synchronized frequency division duplex implementation of discrete multi tone (DMT) modulation. Two communicating Zipper modems transmit DMT symbols simultaneously with a common clock. The Zipper scheme implies that every carrier, in the total set of carriers in the DMT signal, is exclusively chosen to be used for either for the upstream, or the down-stream, direction. When all transmitters are time synchronized, the near end cross-talk (NEXT) and near end echoes, injected into the received signal, are orthogonal to the desired signal. To ensure the orthogonality between the signal and all the noise sources originating from DMT signals in the opposite direction, the guard time, with cyclic extension of the symbols between consecutive symbols, must be dimensioned for the maximum propagation delay of the channel. Further, the size of the guard time is minimised by applying timing advance.
Several duplex VDSL systems may share the same twisted pair copper cable. Such systems are referred to as belonging to the same binder group. VDSL systems, using Zipper, which belong to the same binder group, are affected by line attenuation, near end echo and crosstalk. In known Zipper transmission systems, when timing advance is used, all transceivers, in a binding group, start the transmission of each frame at the same time.
There are three types of signal that affect the length of the cyclic extension in each frame:
the received signal; the echo signal caused by imperfect balance of the hybrid and impedance discontinuities in the line; and the NEXT signal.
Orthogonality, between the received signal, the echo signal and the NEXT signal, is preserved if each sampled DMT symbol is disturbed by a single frame from each one of the near-end transmitters. Because of this, in order to preserve orthogonality, the cyclic extension has to be dimensioned to cover all impulse responses from the line, the echoes and the NEXT.
SUMMARY OF THE INVENTION
However, in certain situations it may be difficult, for practical reasons, or otherwise undesirable, to provide and maintain time synchronization between all transmitters in the same binder group. It is therefore desirable to enable Zipper modems, if necessary, to operate in a non-synchronized mode. In other words, only pairwise syncnronisation is maintained between a VTU-O and VTU-R pair. The present invention provides this option for Zipper modems and systems employing Zipper modems. Thus, the present invention permits different users to transmit time asynchronous DMT frames in the same binder group. However, although this is always possible, a noticeable performance penalty can be expected in many situations because of increased NEXT. One way in which the present invention mitigates increased NEXT is by pulse shaping of DMT frames prior to transmission and providing additional pulse shaping at the receiver. Using pulse shaping at the transmitter has the additional advantage of higher suppression of the side lobes of the DMT spectrum. This increases spectral compatibility with other systems, such as, ADSL and CAP-VDSL.
According to a first aspect of the present invention, there is provided a telecommunications transmission system using zipper having at least two VDSL systems, each comprising a pair of zipper modems, said at least two VDSL systems belonging to a binder group common to both VDSL systems, characterised in that said telecommunications transmission system is adapted to:
handle zipper transmissions transmitted in said binder group; at least partly mitigate NEXT; and permit transmissions in a first VDSL system which are asynchronous with transmissions in at least a second VDSL system.
DMT frames may be pulse shaped prior to transmission.
Said pulse shaping may produces an improved suppression of side lobes of said DMT's spectrum.
A cyclic extension may be added to DMT symbols, said cyclic extension comprising:
a suffix which is greater than, or equal to, a channel's propagation delay; and a prefix which is greater than, or equal to, a guard time needed to eliminate inter-symbol interference.
Said pulse shaping may be produced by forming pulse shaped wings on a DMT frame in cyclic extensions of the DMT frame.
Said pulse shaped wings may be in the form of a raised cosine pulse.
Said pulse shaping may be performed at a transmitter, after addition of a cyclic prefix and cyclic suffix, to a symbol and prior to digital to analogue conversion.
A DMT signal received by a receiver may be windowed to further reduce NEXT.
Said windowing may be performed by:
multiplying μ samples at the beginning and end of a block of 2N+μ samples; folding and adding μ/2 samples from the beginning of the 2N+μ block of samples to the end of the 2N remaining samples; and folding and adding μ/2 samples from the end of the 2N+μ block of samples to the beginning of the 2N remaining samples.
The same number of subcarriers may be used for transmission in the up stream direction as are used for transmission in the down stream direction.
A different number of sub-carriers may be used for transmission in the up stream and down stream directions.
According to a second aspect of the present invention, there may be provided, in a telecommunications transmission system using zipper and having at least two VDSL systems, each comprising a pair of zipper modems, said at least two VDSL systems belonging to a single binder group common to both VDSL systems, a method of transmission characterised by permitting zipper transmissions of said first and, at least, said second VDSL transmission systems, to be transmitted in said single binder group, where transmission in said first VDSL system are asynchronous with zipper transmission in said second VDSL system and in which the effects of NEXT are, at least partly, mitigated.
DMT frames may be pulse shaped prior to transmission.
Said pulse shaping may produce an improved suppression of side lobes of said DMTs spectrum.
A cyclic extension may be added to DMT symbols, said cyclic extension comprising:
a suffix which is greater than, or equal to, a channel's propagation delay; and a prefix which is greater than, or equal to, a guard time needed to eliminate inter-symbol interference.
Pulse shaped wings may be formed on a DMT frame in the cyclic extensions of the DMT frame.
Said pulse shaped wings may be formed as a raised cosine pulse.
Said pulse shaping may be performed at a transmitter after addition of a cyclic extension to a symbol and prior to digital to analogue conversion.
A DMT signal received by a receiver may be windowed to further reduce NEXT.
The following steps may be used to perform said windowing:
multiplying μ samples at the beginning and end of a block of 2N+μ samples; folding and adding μ/2 samples from the beginning of the 2N+μ block of samples to the end of the 2N remaining samples; and folding and adding μ/2 samples from the end of the 2N+μ block of samples to the beginning of the 2N remaining samples.
The same number of sub-carriers may be transmited in both an upstream and down stream direction.
A different number of sub-carriers transmited in the up stream and down stream directions.
According to a third aspect of the present invention, there is provided a transmitter, for use in a transmission system as set forth in any preceding paragraph, characterised in that said transmitter comprises an a b-bit buffer and encoder for receiving an input bit stream at a rate of R bit/s, a n-point IDFT processor for receiving an output from said b-bit buffer and encoder, extension means for adding a cyclic extension to an output of said IDFT processor, a pulse shaper for shaping a DMT symbol output from said extension means, and a digital to analogue converter and low pass filter for converting a DMT symbol received from said pulse shaper to analogue form and passing said DMT to a transmission channel.
Said pulse shaper may form pulse shaped wings on said DMT symbol as raised cosine pulses.
According to a fourth aspect of the present invention, there is provided a receiver, for use in a transmission system as set forth in any preceding paragraph, characterised in that said receiver includes an analogue to digital converter for digitising a DMT symbol received from a transmission channel, a windowing unit connected to an output of said analogue to digital converter, a stripper unit for removing cyclic extensions to said DMT symbol, an n-point DFT processor for receiving an output from said stripper unit, a frequency domain equalisation unit for receiving an output from said n-point DFT unit and decoder, and a b-bit buffer for receiving an output from said frequency domain equalisation unit and outputting a bit stream at R bit/s.
Said windowing unit may perform the following operations:
multiplying μ samples at the beginning and end of a block of 2N+μ samples; folding and adding μ/2 samples from the beginning of the 2N+μ block of samples to the end of the 2N remaining samples; and folding and adding μ/2 samples from the end of the 2N+μ block of samples to the beginning of the 2N remaining samples.
According to a fifth aspect of the present invention, there is provided a modem, for use in a transmission system as set forth in any preceding paragraph, characterised in that said modem includes a transmitter as set forth in any preceding paragraph.
Said modem may include a receiver, as set forth in any preceding paragraph.
Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates the generation of interference signals, cross-talk and echo, that affect the orthogonality of Zipper.
FIG. 2 illustrates sampling, at the VTU-O side, of a received frame disturbed by frames from near end transmitters.
FIG. 3 illustrates a DMT transmitter/receiver pair for down-stream transmission, exemplifying symmetric communication where every second sub-carrier is used, respectively, for the up (u), and down-stream (d), directions.
FIG. 4 illustrates the frame format for zipper.
FIG. 5 illustrates non-orthogonal NEXT.
FIG. 6 illustrates pulse shaping of the DMT frame.
FIG. 7 is a schematic illustration of the pulse shaping process in the transmitter and the windowing process in the receiver.
FIG. 8 illustrates windowing of a received DMT frame.
FIG. 9 illustrates asynchronous non-orthogonal NEXT with and without windowing and pulse shaping.
DETAILED DESCRIPTION
To fully appreciate the operation of the present invention it is necessary to consider the invention disclosed in our earlier co-pending patent application WO 9706619. As previously explained, the present invention enables Zipper to be used in a manner in which VDSL systems operating in the same binder group can operate without mutual synchronisation between each system.
Zipper, as disclosed in our co-pending patent application WO 9706619, is a time-synchronized frequency-division duplex implementation of discrete multi tone (DMT) modulation. Two communicating Zipper modems transmit DMT symbols simultaneously with a common clock. The Zipper scheme implies that every carrier, in the total set of carriers in the DMT signal, is selected for use in either the up-stream, or the down-stream, direction. When all transmitters are time synchronized, the near end cross-talk (NEXT) and near end echoes injected into the received signal, are orthogonal to the desired signal. To ensure that orthogonality is maintained between the signal and all the noise sources, originating from DMT signals in the opposite direction, the guard time with cyclic extension of the symbols, between consecutive symbols, must be dimensioned for the maximum propagation delay of the channel. Further, the size of the guard time is minimized by applying timing advance.
FIG. 1 depicts how two VDSL systems, sharing the same cable, i.e. in the same binder group, are affected by line attenuation, near end echo and cross-talk. Sources of interference that can be identified include:
echo generated within the hybrids and passed from the transmitters to the receivers; NEXT which passes between the transmitter-receiver pairs at the near end; and FEXT which passes between the transmitter-receiver pairs at the far end and is transmitted over the full cable length.
When timing advance is used, all transceivers start the transmission of each frame at the same time. There are three types of signals that affect the length of the cyclic extension in each frame: the received signal, the echo-signal due to imperfect balance of the hybrid and impedance discontinuities in the line, and finally the NEXT signal. FIG. 2 shows sampling at the VTU-O side of received frame disturbed by frames from near-end transmitters.
As can be seen from FIG. 2 , the orthogonality between the desired part of the received signal and the disturbances (interference signals) is preserved if each sampled DMT symbol is disturbed by a single frame from each one of the near-end transmitters. As a consequence, to preserve orthogonality, the cyclic extension has to be dimensioned to cover all impulse responses from the line, the echoes, and the NEXT.
The management of the capacity split between up-stream and down-stream is performed by assigning individual carriers for both directions. For example, if a fully symmetric service is required, sub-carriers with even indices can be assigned to the up-stream and sub-carriers with odd indices can be assigned to the down-stream. Similarly, for an asymmetric 8:1 split, each ninth carrier can be assigned to the up-stream and the other carriers assigned to the down-stream. However, for the sake of spectral compatibility with other existing and future systems, operating on the same cable, alternative carrier assignments can be used.
The transmission and reception of symbols is performed simultaneously at both ends by the VTU-O and by the VTU-R. For down-stream transmission the bit stream is encoded by the VTU-O transmitter into a set of quadrature amplitude modulated (QAM) sub-symbols, where each QAM sub-symbol represents a number of bits determined by the signal-to-noise ratio (SNR) of its associated down-stream sub-channel, the desired overall error probability, and the target bit rate. The set of sub-symbols is then input, as a block, to a complex-to-real discrete Fourier transform (IDFT) processor, see FIG. 3 . Following the IDFT, a cyclic prefix is added to the output samples to eliminate intersymbol interference, and a cyclic suffix is appended to the output samples to maintain orthogonality between the desired signal and near-end distorting signals. The result is then converted from digital to analog format and applied to the channel.
Thus, the input bit stream, see FIG. 3 , enters a b-bit buffer and encoder, from which its is passed to the N-point IDFT processor and thence to the cyclic extension adder. Following which the signal is passed via the DAC and lowpass filter to the channel.
At the VTU-R receiver, after analog-to-digital conversion, the cyclic prefix and suffix are stripped, and the samples are transformed back to the frequency domain by a DFT. Each output value used for down-stream transmission is then scaled by a single complex number to compensate for the magnitude and the phase of each down-stream sub-channel's attenuation, and a detector decodes the resulting symbols. The multiplication with this set of complex numbers, one per down-stream sub-channel, is called frequency-domain equalization (FEQ). FIG. 3 shows a block diagram of a DMT transmitter and receiver pair, assuming a noiseless channel.
In the steady-state, the subchannel SNRs are monitored in a data-driven manner by the VTU-R during down-stream symbol periods, and the bit distribution is modified, as necessary, at the VTU-O, to optimize system performance. Upon detecting a degradation, or improvement, in one, or more, sub-channel SNRs, the VTU-R computes a modified bit distribution that better meets the desired error performance. Depending on the SNR of a degraded sub-channel, some, or all, of its bits may be moved, via a bit swap algorithm, to one, or more, other sub-channels that can support additional bits. The bit distribution change is reported to the VTU-O, where it is implemented.
For up-stream transmission, the roles of the VTU-O and VTU-R are reversed, that is, transmission and reception are performed on the up-stream set of sub-channels and the operations described above are the same.
The frequency range from zero to 11.04 MHZ is partitioned into 2,048 sub-channels. The Nyquist carrier (sub-channel 2,048) and the dc carrier (sub-channel 0 ) are not be used for data.
Transmission may occur on up to 2047 sub-carriers, although those sub-carriers overlapping the POTS, ISDN, and amateur radio frequency bands are typically not used in the default configuration. The lowest sub-channel available to support data transmission is dependent on the POTS/ISDN splitter design.
The frame format for Zipper comprises two parts, namely:
the DMT symbol; and the cyclic extension.
Orthogonality is maintained between the received signal and interfering DMT signals transmitted in the opposite direction, if they are sufficiently aligned in time. This requirement is fulfilled by the addition of a cyclic extension to the DMT symbol and the use of timing advance (TA). For the ease of description, the cyclic extension can be divided into a cyclic prefix and a cyclic suffix, where:
the suffix is greater than, or equal to, the propagation delay of the channel; and the prefix is greater than, or equal to, the guard time needed to eliminate inter-symbol interference.
FIG. 4 illustrates the frame format for zipper.
When timing advance is used all transmitters commence transmission at the same time. The suffix part of the cyclic extension can be treated as an extra guard time required to maintain orthogonality between the up and down-stream channels along the wire line. To fulfil the orthogonality requirement at the receiver, the cyclic extension (prefix+suffix) must also cover the impulse response of the NEXT and the echo signal.
The first L cs samples of the IDFT output are appended to the block of 4096 time-domain samples x k . The last L cp samples of the IDFT output are prepended to the block. The frame of samples is then read out to the digital-to-analog converter (DAC), see FIG. 3 , in sequence. That is, the subscripts k of the DAC samples in the sequence are (4096-L cp ), . . . , 4095, 0, 1, . . . 4094, 0, 1, . . . (L cs −1).
The length of the cyclic extension (L cp and L cs ) is typically a programmable entity set by the network operator.
In order to maximize high duplex efficiency, timing advance can be used so that the VTU-O transmitters and the VTU-R transmitters start transmitting each DMT frame at the same time. During the reception, a DMT symbol is only disturbed by single symbols, not affected by IFI, in the other direction due to the cyclic extension.
Zipper is a duplexing scheme based on the Discrete Multitone Modulation (DMT) line-coding technique and was invented at Telia Research in 1995. A patent application, SE 952775 (corresponding to WO9706619) was filed on 4 th August 1995.
In certain situations, it may be difficult for practical reasons, or it may be undesirable, to provide and maintain time synchronization between all transmitters in the same binder group. It is therefore desirable to provide an option for Zipper modems which enables them to operate in a non-synchronized mode, where only pairwise synchronization is maintained between a VTU-O and VTU-R pair. Thus, the present invention allows different users to transmit time-asynchronous DMT frames in the same binder group. However, although this is always possible, a noticeable performance penalty, due to increased NEXT, is to be expected in many situations. One possible method of mitigating this is to use pulse shaping of the DMT frames prior to transmission and additional pulse shaping in the receiver. The use of pulse shaping at the transmitter results in a higher suppression of the side lobes of the DMT signal spectrum and gives higher spectral compatibility with other systems, for example, ADSL and CAP-VDSL.
When different pairs of transceivers (modems) operating in the same binder group are asynchronous, interference from NEXT will be introduced, because, the NEXT becomes non-orthogonal and therefore degrades the performance. The reason for the NEXT becoming non-orthogonal is that the received and sampled DMT frame will include NEXT from two consecutive DMT frames which are discontinuous, as depicted in FIG. 5 .
In order to be able to operate in a non-synchronized mode it is necessary to suppress the NEXT by narrowing its out-of-band spectrum which interferes with the spectrum of the received signal. This can be effected by pulse shaping the DMT frame before transmission.
Pulse shaping a DMT frame is performed by forming pulse-shaped wings, e.g. from a raised cosine pulse, in the cyclic extensions of the frame as shown in FIG. 6 .
With pulse shaping a continuous phase is created between succeeding frames which suppresses the NEXT-interfering subcarriers' side lobes.
The pulse shaping operation is performed at the transmitter after the cyclic extension is added to the symbol and before the digital to analog conversion (DAC) is performed. The position of the pulse shaping unit is depicted in FIG. 7 which shows a block diagram of a transceiver/modem according to the present invention. The construction and operation of a VDSL modem will be immediately apparent to those skilled in the art from, FIG. 7 , without further explanation. However, for the sake of completeness a brief description of FIG. 7 is set out below.
The transmitter arm of the modem is shown at the top of FIG. 7 . The input bit stream, at Rbits/s, is passed to a n-bit buffer and encoder from whence a parallel signal, Xd 1, k , Xu 2, k =0 . . . Xd N−1, k , Xu N, k =0, is passed to an n-point IDFT processor. The output from the IDFT processor, x 1 ,k , X 2, k . . . X N, k , is then passed to a unit, P/S, where the cyclic extensions, both prefix and suffix, are added to the DMT symbol. The DMT symbol with cyclic extensions then passes to a pulse shaping unit where the pulse is shaped as described above. The DMT symbol is then passed to a digital to analogue convertor and low pass filter and thence to the transmission channel.
The receiver arm of the modem is shown at the bottom of FIG. 7 . An incoming signal from the channel is first passed, via a low pass filter and analogue to digital convertor, to a windowing unit, see below for further details. The symbols are then passed to a stripper unit which strips off the cyclic extensions, both prefix and suffix, and thence, as a signal y 1, k , y 2, k . . . y N, k , to a n-point DFT processor. The signal, Yd 1, k , Yu 2, k . . . Yd N−1, k , Yu n,k , is then passed to a frequency domain equaliser, FEQ, see the description of FIG. 3 , and thence to a decoder and n-bit buffer, as a signal Xd 1, k , XU 2, k . . . Xd N−1, k , XU N, k , which outputs the received data stream at R bits/s.
Windowing the received DMT frame, as shown in FIG. 8 , further suppresses the non-orthogonal NEXT. The windowing is performed by multiplying μ samples, at both the beginning and end of the 2N+μ block of samples. The μ/2 samples from both ends are folded and added to the 2N remaining block of samples at the opposite ends as shown in FIG. 8 . As with the pulse shaping of the DMT frames in the transmitter, the windowing in the receiver creates a continuous phase of the non orthogonal NEXT signals. The positioning of the windowing is shown in FIG. 8 .
FIG. 9 shows the combined effect, on the non-orthogonal NEXT, of pulse shaping the DMT-frame in the transmitter and windowing the received frame in the receiver. FIG. 9 also shows the signal energy, the NEXT reference signal without pulse-shaping and windowing, the NEXT signal after pulse-shaping and windowing and the FEXT signal at each sub-carrier. As seen in the figure, more than 25 dBm/Hz further suppression can be obtained by both pulse shaping and windowing.
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Zipper is the time-synchronized frequency-division duplex implementation of discrete multi-tome (DMT) modulation. Two communicating Zipper modems transmit DMT symbols simultaneously with a common clock. When all transmitters are time synchronized, the near end cross-talk (NEXT) and near end echoes injected into the received signal are orthogonal to the desired signal. The present invention provides a telecommunications transmission system using zipper and having at least two VDSL systems. Each VDSL system comprises a pair of zipper modems communicating over a cable transmission path. The telecommunications transmission system handles zipper transmission transmitted over the common cable; at least partly mitigates NEXT; and permits transmissions in a first VDSL system which are asynchronous with transmissions in a second VDSL system.
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RELATED APPLICATION
This application is related to an application entitled "Mold Press with Dielectric Electrodes", Mr. David R. Stewart inventor, filed Aug. 31, 1988, Ser. No. 239,104.
BACKGROUND OF THE INVENTION
The mechanical properties of thermoplastic articles of manufacture may be improved by stretching the thermoplastic within an optimum temperature range. For example, when producing thermoplastic fibers, it is common to stretch the fiber by drawing the fiber through a die, which reduces the diameter of the fiber and orientes the polymer molecules in the direction of drawing. This is commonly done using rollers. A first roller is temperature regulated so as to hold the temperature of the fiber at the desired temperature and a second roller is run at a speed faster than the first roller in order to stretch the fiber. The temperature at which the fiber is stretched is very important in that it determines the degree of orientation of the polymer molecules and therefore the strength and feel of the fiber.
This same method is used to stretch thermoplastic film(s) or sheet(s) or laminates formed therefrom and again it is important that the temperature be controlled in order to optimize the mechanical properties. As used herein in this specification and the claims, a laminate shall mean a laminated sheet, film, fiber, coaxial fiber, billet, etc.
Blow molding, thermoforming and the solid phase forming processes also require temperature control in order to obtain the correct melt strength and/or orientation during the forming of the article.
This is especially true during the solid phase forming processes since the thermoplastic material must be formed at temperatures just below the melt or softening point of the billet or sheet in order to obtain the optimum properties.
All of the above stretching processes typically involve the use of laminates or coaxial fibers of one or more thermoplastics. Heating the laminate or coaxial fibers and stretching them for any of the stretching processes is done while all of the layers of the thermoplastic are essentially at the same temperature.
Thus, the sheet, billet, or fiber is heated before stretching by applying sufficient thermal energy to the surface of the article to allow the article to reach an essentially even temperature profile (i.e. the temperature profile indicated by line T6 in prior art FIG. 1 where both sides are heated, or indicated by line Ts in prior art FIG. 2 where one side is heated) before stretching.
In most situations, the temperature differences between any two portions of the laminate and the time intervals between heating and stretching are such that all portions of the laminate are essentially at the same temperature during the stretching operation. In fact, it is usually the object of stretching process to get as small a temperature gradient as possible across the cross section of the sheet, film, fiber or billet during its stretching process.
It is possible to obtain a temperature gradient across the cross section of the material by heating the surface of the sheet, film, fiber or billet at a high temperature and stretching immediately. This type of heating will give a temperature profile which resembles that shown by lines T1-T5 in FIG. 1 or T0-T9 in FIG. 2. The line labelled TO in FIG. 2 describes the temperature profile at the initial stage of heating.
When one has a laminated sheet, film, fiber or billet made of two or more diverse thermoplastics whose optimum process temperatures are different, it is necessary to choose a temperature at which to process the laminate which is either best for one or another of the materials in the laminate or to choose a temperature somewhere between the optimum for each of the materials, i.e. optimum for neither. It is possible that the two materials have such diverse process temperature requirements that it is impossible to find a temperature which is appropriate for stretching. For example, when making containers, it would be desirable to use a laminate which comprises a polypropylene layer positioned adjacent an ethylene/vinyl alcohol copolymer layer. If such a laminate could be thermoformed at the optimum processing temperatures for both thermoplastics the resulting shaped laminate would exhibit excellent strength and impact properties and superior barrier properties. In most instances, however, the container maker is forced into using an ethylene/vinyl alcohol copolymer with a lower than desired vinyl alcohol content in order to get the ethylene/vinyl alcohol copolymer to process at the temperature at which they wish to process the polypropylene.
A process need be developed that allows the different layers of a laminate to be heated to their different optimum processing temperatures, prior to shaping the laminate into the desired article of manufacture. Such a process should allow each individual layer to be quickly heated to a desired narrow temperature range before the stretching process, to prevent the temperatures of adjacent layers from drifting towards one another due to conduction between the layers.
SUMMARY OF THE INVENTION
A laminate having at least one non-dielectrically heatable first material, (processable at an optimum starting temperature), and at least one dielectrically-heatable second material, (processable at a higher optimum finish temperature), is initially brought to its starting temperature. The dielectrically heatable second material is then heated to its finish temperature, by being subjected to radio frequency (RF) or microwave radiation at selected frequency(s). The laminate is then stretched so as to shape the laminate while the first material and second material are at or near to their optimum processing temperatures.
In one embodiment of this invention, a flat laminate formed from a first thermoplastic material layer and a second thermoplastic material layer is brought to the optimum processing starting temperature of the first material, by any heating or cooling method. For example, both laminate layers may be heated to the starting temperature in an infrared, electric resistance, or gas oven, or air-cooled after the layers are extruded. The second material layer is then heated to its optimum processing finish temperature by radio frequency or microwave radiation, such that both layers are at or near to their optimum processing temperature(s).
The laminate is then stretched or formed, before the layer heated to the higher finish temperature has transferred much of its heat to the layer heated to the lower starting temperature. Each laminate layer can be heated to a different temperature prior to the stretching process and a more optimum processing of the two or more layers can be achieved. The field strength of the radio frequency or microwave radiation is adjusted to that needed in order to heat the desired layer(s) from the starting temperature to the final temperature at the desired rate.
The invention provides a method of processing laminates wherein laminates which previously had not been processable may now be processed.
It is therefore an object of the present invention to manufacture articles consisting of shaped thermoplastic laminates having improved mechanical properties.
It is a feature of the present invention to dielectrically heat selected layers of the laminate to their optimum processing temperature immediately prior to stretching the laminate.
These and other features, objects, and advantages of the present invention will become apparent from the following detailed description, wherein reference is made to the Figures in the accompanying drawings.
IN THE DRAWINGS
FIG. 1 is a graphical representation of the temperature variation over time of a laminate cross section with heat sources placed at each side.
FIG. 2 is a graphical representation of the temperature variation over time of a laminate cross section with one heat source placed at one side.
FIG. 3 is a graphical representation of the temperature variation of a laminate cross section when the center EVAL F layer has reached the finish temperature due to dielectric heating.
DETAILED DESCRIPTION
A portion of the layer materials which typically make up the sheet, film, fiber and/or billet laminate is typically selected from polyolefins, such as polypropylene, polyethylene, polybutene, polybutadiene, polyisoprene, and their copolymers. These materials are essentially transparent to RF and/or MW heating and are therefore not heatable by dielectric heating. These materials are combined in the laminate with dielectrically-heatable layer materials formed for example from polyvinyl chlorides, polyvinylidiene chlorides, nylons, polyvinyl alcohols, acrylonitrile, cellulose, etc. which have polar moieties and therefore will heat at certain RF and/or MW frequencies.
Referring now to FIG. 3 an example of a laminate layer sequence heatable according to the teachings of the present invention would be a 20 mil layer of polypropylene, a 20 mil scrap layer, a 2 mil adhesive tie layer, a 40 mil EVAL F layer, (EVAL being ethylene vinyl alcohol copolymer), a 2 mil adhesive tie layer, a 20 mil scrap layer and a 20 mil polypropylene layer. The adhesive tie layer material is a propylene/maleic anhydride graft copolymer, and the scrap layer material is a blend of the regrind of all of the materials. This stack of layers can be in the form of a billet which had been stamped (cut) out of sheets of the layer material(s).
In a preferred embodiment the billet is heated in an electric resistance heated oven to the processing temperature of polypropylene, 155° C. It is then transferred to a dielectric heater and irradiated with a frequency of 100 MHz for 20 seconds. At this point the polypropylene layer, which did not heat by dielectric radiation, is at a starting temperature of 155° C. and the EVAL F layer, which did heat dielectrically, is at a finish temperature of 185° C. The billet is then quickly transferred to a solid phase pressure-forming mold and a cup made. At the end of the forming cycle the temperature of the polypropylene layer was between 150° C. and 155° C. and the temperature of the EVAL F layer was between 165° C. and 185 ° F. Thus, the two layers had been stretched at a temperature which resulted in the desired orientation for each layer.
If one had attempted to process this billet at the temperature best for EVAL F, i.e. 170 to 185 ° C., the polypropylene would have been above its melting point, i.e. it would not have been solid phase formed. In fact, it would have been above its best thermoforming or blow molding temperature. If one had tried to process the laminate at 155° C., one would have been so far below the processing temperature of EVAL F that the thermoplastic material would neck and/or tear, thereby destroying the barrier properties of the laminate.
The scrap layer will heat slower than the EVAL F layer because the concentration of the polar -OH moiety is less. The adhesive layer, which contains maleic anhydride moieties, will not heat at the frequency at which the EVAL F layer will heat. The scrap layer and the adhesive tie layer help insulate the polypropylene from the EVAL F.
In another embodiment of this invention, a second polyolefin or second layer may be added to the multilayer laminate to help insulate the dielectrically-heatable layer from the non-dielectrically heatable layer. For example, a polypropylene/ polyethylene/ EVAL F/ polyethylene/ polypropylene laminate can be used where the polyethylene layer insulates the EVAL F and polypropylene from each other.
In another embodiment of the invention, three thermoplastic materials comprising polyvinylidene floride (KYNAR®), EVAL®, and polypropylene, are combined to make a laminate whereby frequencies and field strengths can be chosen so that three different temperatures can be obtained in the three different material layers. The laminate so formed can be brought to a starting temperature of 150° C., then a first dielectric radiation field having a first frequency of 30 MHz and a first field strength of 3000 volts/cm, and a second dielectric radiation field having a second frequency of 100 MHz and a second field strength of 5000 volts/cm may be simultaneously applied to the billet so as to heat the KYNAR to a first finish temperature between 170-180° C. and the EVAL to a second finish temperature between 180° C. to 190° C. It is preferred that where there are two different layers that heat dielectrically, that a dielectrically transparent and/or insulating layer separates the two heatable layers.
It is possible to take advantage of the temperature/frequency dependence of the loss factor for a particular polymer so that, for example, a layer of a laminate can be heated at a frequency such that as the temperature goes up, the heat input goes down and a certain minimum temperature is the maximum reachable at that frequency. This could be used to bring the whole laminate to the starting temperature. Then just before one is ready to process, the frequency is changed to one where a layer is known to have a high heat loss so as to kick the temperature of that layer to its preferred finish temperature.
Frequency change with temperature can also be used to increase the rate at which a layer is heated.
It is preferred that the time between starting to kick the temperature of a layer or layers from the starting temperature to the finish temperature be as short as possible. This will minimize the exchange of heat between the layers by conduction. To minimize the heatup time, one may follow the shift of loss factor with temperature by heating at two or more frequencies. Where, for example, two frequencies are used, it is preferred that the first frequency is approximately one of maximum heat gain at the starting temperature and the second frequency is closer to the maximum heat gain at the finish temperature.
When there is some heat exchange between the layers in the time period between kicking the temperature and processing, it is possible to heat the entire laminate to a starting temperature several degrees below the preferred processing temperature of the layer having the lowest processing temperature, and then to dielectrically heat the dielectrically heatable layers to their finish temperature, and then to stretch the laminate. The lower temperature layer will have its temperature raised several degrees by the dielectrically heated layer via conduction.
It should be recognized that the temperature gradient shown in FIG. 3 is novel in that the outside of the sheet, film, fiber or billet is at a lower temperature than the inside.
In another embodiment of the invention, the laminate comprises at least two plastics that will heat at different frequencies, i.e. plastic A will heat at frequency X and not Y and plastic B will heat at frequency Y and not X. This laminate is heated simultaneously at frequencies X and Y at field strengths that will simultaneously bring the two layers to the desired temperature at the same time. That is, the field strength at X and the field strength at Y will be adjusted to heat the layers at a rate such that both layers reach their respective processing temperatures at the same time, i.e. at the moment of processing.
The temperature difference between two adjacent layers at the time of stretching can be between 20 and 30 degrees Centigrade, with or without an insulating layer therebetween.
Many other variations and modifications may be made in the apparatus and techniques hereinbefore described by those having experience in this technology, without departing from the concept of the present invention. Accordingly, it should be clearly understood that the apparatus and methods depicted in the accompanying drawings and referred to in the foregoing description are illustrative only and are not intended as limitations on the scope of the invention.
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A laminate having at least one non-dielectrically heatable first material, (processable at an optimum starting temperature), and at least one dielectrically-heatable second material, (processable at a higher optimum finish temperature), is initially brought to its starting temperature. The dielectrically heatable second material is then heated to its finish temperature, by being subjected to radio frequency (RF) or microwave radiation at selected frequency(s). The laminate is then stretched so as to shape the laminate while the first material and second material are at or near to their optimum processing temperatures.
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TECHNICAL FIELD
The invention relates to a hearing device. The hearing device can be a hearing aid, worn in or near the ear or (partially) implanted, a headphone, an earphone, a hearing protection device, a communication device or the like. The invention relates furthermore to a method of operating a hearing device and the use of MIDI—i.e., Musical Instrument Digital Interface—compliant data in a hearing device.
STATE OF THE ART
Today, many hearing devices, e.g., hearing aids, are capable of generating some simple acoustic acknowledge signals, e.g., a beep or double-beep signaling that a first or a second hearing program has been chosen by the user of the hearing device.
In WO 01/30127 A2 a hearing aid is disclosed, which allows to feed user-defined audio-signals into the hearing device, which user-defined audio-signals can then be used as acknowledge signals.
U.S. Pat. No. 6,816,599 discloses an ear-level electronic device within a hearing aid, capable of generating electrical signals representing music. By means of a pseudo-random generator extremely long sequences of music can be created which can produce a sensation of relief to persons suffering tinnitus.
In the world of electronic music, where music synthesizers, electronic keyboards, drum machines and the like are used, the Musical Instrument Digital Interface (MIDI) protocol has been introduced in 1983 by the MIDI Manufacturers Association (MMA) as a new standard for digitally representing musical performance information. A number of specifications of MIDI-related data formats have been issued by the MMA within the last 10 to 20 years. Within the last couple of years, MIDI-compliant data (MIDI data) have found application in mobile phones, where MIDI data, in particular data compliant with the Scalable Polyphony MIDI (SP-MIDI) specification, introduced in February 2002, are used for defining telephone ring tones.
SUMMARY OF THE INVENTION
One object of the invention is to create a hearing device that provides for an alternative way of defining sound information to be perceived by a user of the hearing device.
Another object of the invention is to provide for a hearing device with an enhanced compatibility to other equipment.
Another object of the invention is to provide for a hearing device which can easily be individualized and adapted to a user's taste and preferences.
These objects are achieved by a hearing device according to patent claim 1 .
In addition, the respective method for operating a hearing device and the use of MIDI compliant data in a hearing device shall be provided.
The hearing device according to the invention is MIDI compatible, i.e., Musical Instrument Digital Interface compatible.
MIDI specifications are defined by the MIDI Manufacturers Association (MMA). In 1983 the Musical Instrument Digital Interface (MIDI) protocol was introduced by the MMA.
In the MMA various companies from the fields of electronic music and music production are joined together to create MIDI standards and specifications assuring compatibility among MIDI-compatible products. Since 1985 the MMA has issued about 11 new specifications and adopted about 38 sets of enhancements to MIDI.
Unlike MP3, WAV, AIFF and other digital audio formats, MIDI data do not (or at least not only) contain recorded sound or recorded music. Instead, music is described in a set of instructions (parameters) to a sound generator, like a music synthesizer. Therefore, playing music via MIDI (i.e., using MIDI data) implies the presence of a MIDI-compatible sound generator or synthesizer. MIDI data usually comprise messages, which can instruct the synthesizer, which notes to play, how loud to play each note, which sounds to use, and the like. This way, MIDI files can usually be very much smaller than recorded digital audio files.
The current MIDI specification is MIDI 1.0, v96.1 (second edition). It is available in form of a book: ISBN 0-9728831-0-X. Originally, the MIDI specification defined a physical connector and, in what can be referred to as the MIDI Message Specification, also named MIDI protocol, a message format, i.e., a format of MIDI messages. Some years later, a file format (storage format) called Standard MIDI is File (SMF) was added. An SMF file contains MIDI messages (i.e., data compliant with the MIDI protocol), to which a time stamp is added, in order to allow for a playback in a properly timed sequence.
MIDI specifications or MIDI-related specifications (companion specifications), issued by the MMA, of (potential) interest for the invention comprise at least the following ones:
the MIDI protocol defining MIDI messages (see above) the Standard MIDI file format (SMF), see above; the MIDI Machine Control specification (MMC), meant for controlling machines like mixing consoles or other audio recording equipment; the MIDI Show Control specification (MSC), meant for controlling lamps and machines like smoke machines; the MIDI Time Code specification (MTC), for synchronizing MID equipment; the General MIDI Specifications (GM/GM 1, GM 2, GM Lite), defining several minimum requirements (e.g., on polyphony) and allocation of standard sounds, in order to assure some standard performance compatibility among MIDI instruments so as achieve similarly sounding results when using different platforms; the Scalable Polyphony MIDI specification (SP-MIDI, issued February 2002, corrected November 2001), which defines MIDI messages allowing a sound generator to play, in a well-defined way, music that usually would require a higher polyphony (i.e., a higher number of simultaneously generatable sounds) than the sound generator is capable of producing; in other words, depending on the available polyphony of the sound generator, tones are played and not played, in a well-defined way; a file format called DownLoadable Sounds Format (DLS Level 1, DLS-1, version 1.1b issued September 2004, DLS Level 2, DLS-2, version 2.1, amended November 2004), which defines a way of providing sounds (samples, WAV files) and articulation parameters for the sounds, so that at least a part of the notes of a MIDI song can be heard with original sounds instead of with sounds given by the sound generator, which are often not very close to the original; a file format called eXtensible Music Format (XMF), version 2.0 issued in December 2004, which defines a standard for gathering in one single file a number of different data (e.g., SMF files and DLS data) required to assure a consistent audio playback of MIDI note-based information on various platforms; the SMF w/DLS File Format Specification (February 2000) defining a file format for bundling an SMF file with DLS data, known as RMID file format, which is outdated today and, since November 2001, recommended to be replaced by the XMF file format (see above); the DLS format for mobile devices (MDLS) issued September 2004, based on DLS-2; the Mobile XMF specification, version 2.0 issued September 2004 together with MDLS; and the Standard MIDI File (SMF) Lyrics Specification (SMF Lyric Meta Event Definition), issued January 1998, which defines a recommended way of implementing lyrics in SMF files.
MIDI specifications, definitions, recommendations and further information about MIDI can be obtained from the MMA, in particular from via the internet at http://www.midi.org.
Through providing the hearing device with MIDI compatibility, a new way of defining sound in a the hearing device is provided, in particular a new way of defining sound information to be perceived by a user of the hearing device. The hearing device is provided with an enhanced compatibility to other equipment, in particular other MIDI compatible equipment. The hearing device can easily be individualized and adapted to the user's taste and preferences. A well-tested and efficient way of representing sound is implemented into the hearing device, which can be advantageous, in particular when the sound is complex, e.g., due to polyphony or length and number of notes to be played, respectively.
The term MIDI data shall, at least within the present patent application, be understood as data compliant with at least one MIDI specification (or MIDI-related specification), in particular with one of those listed above.
More specifically, the term MIDI data can be interpreted as data compliant with the (current) MIDI protocol, i.e., MIDI messages (including data of SMF files).
The hearing device according to the invention can be adapted to comprising MIDI data.
The hearing device can be adapted to
communicating and/or loading and/or storing and/or interpreting and/or generating: data compliant with the MIDI Protocol (messages compliant with the MIDI Message Specification; MIDI messages), and/or Standard MIDI Files, and/or files in the eXtensible Music Format, and/or Mobile XMF files, and/or data compliant with the SP-MIDI specification, and/or DLS data, i.e., data compliant with the DownLoadable Sounds Format, and/or Mobile DLS data, and/or MMC data, and/or MSC data, and/or MTC data, and/or General MIDI data, and/or RMID files, and/or files compliant with the SMF Lyric Meta Event Definition.
The hearing device can comprise a MIDI interface. The MIDI interface allows for a simple communication of MIDI data with other devices.
The hearing device can comprise a sound generator adapted to interpreting MID data. An efficient control of the sound generation can thus be achieved, which, in addition, is compatible with a wide range of other sound generators. The hearing device can comprise a unit for interpreting MIDI data. That unit may be realized in form of a processor or a controller or in form of software. MIDI data can be transformed into other information, e.g., information to be given to a sound generator within the hearing device so as to have a desired sound or piece of music played.
One way of using MIDI data in a hearing device is in conjunction with the generation of sound to be perceived by the hearing device user. E.g., acknowledge sounds, also called feedback sounds, which are played to the user upon a change in the hearing device's function, e.g., when the user changes the loudness (volume) or another setting or is program, or when some other user's manipulation shall be acknowledged, or when the hearing device by itself takes an action, e.g., by making a change, e.g., if, in the case of a hearing aid, the hearing aid chooses, in dependence of the acoustical environment, a different hearing program (frequency-volume settings and the like), or when the hearing device user shall be informed that a hearing device's battery is low.
It is also possible to use MIDI in a hearing device in conjunction with musical signals to be played to the user of the hearing aid. And it is also possible to use MIDI in a hearing device in conjunction with guiding signals, which help to guide the user, e.g., during a fitting procedure, during which the hearing device is adapted to the user's hearing preferences.
Furthermore, according to today's trend to individualization, it is possible to personalize a hearing device by aid of MIDI. E.g., said acknowledge sounds could be loaded into the hearing device in form of MIDI data. From the hearing device manufacturer or from a third party, the hearing device user could receive, possibly against payment, MIDI data for such sounds, chosen according to the user's taste.
It is possible to load such MIDI data to the hearing device, which define the sound to be played to the hearing device user when the user's (possibly mobile) telephone rings. And even, a number of ring sounds can be loaded into the hearing device, wherein the sound to be played to the hearing device user when the user's telephone rings, is chosen in dependence of the person who calls the hearing device user, or, more precisely, depending on the telephone number of the telephone apparatus from which the hearing device user is called.
This may be accomplished, e.g., by either sending MIDI data to the hearing device upon an incoming call in the telephone, or by having MIDI data stored in the hearing device, which describe ring tones, and upon an incoming call in the telephone, the hearing device receives not the actual MIDI data, but a link instructing the hearing device, which of the MIDI-based ring tones stored in the hearing device to play to the hearing device user.
In addition, it is possible to use MIDI data in a hearing device in conjunction with speech synthesis. E.g., speech signals stored in the hearing device could be addressed or controlled by MIDI data. Or speech signals, be it synthesized or sampled, could be encoded in MIDI, e.g., using the DownLoadable Sounds Format (DLS) of MIDI.
Furthermore, it is possible to listen to music (pop, classic or others) encoded in MIDI with the hearing device. A hearing device comprising a sound generator could interpret MIDI data loaded into the hearing device and generate the corresponding music thereupon. Various musical pieces and works are today already available in form of MIDI data. Music could thus be generated within the hearing device and played to the hearing device user without the need for external sound generators like Hifi consoles or music synthesizers plus amplifiers. The MIDI DLS standard could be used here to achieve a particularly good and realistic audio reproduction.
In several of the above-described embodiments, the hearing device can be considered to comprise a converter for converting MIDI data into audio signals to be perceived (usually after an electro-mechanical conversion) by the hearing device user. Such a converter can be or comprise a signal processor, e.g., a digital signal processor (DSP), the converter can be or comprise a controller plus a sound generator or a controller plus a DSP. Also a sound memory may be comprised in the converter.
The hearing device is typically an ear level device. It may be worn partially or in full in or near the user's ear, or it may fully or in part be implemented, e.g., like a cochlea implant.
A hearing system according to the invention comprises a hearing device according to the invention. It may comprise one or more external microphones, a remote control or other parts.
According to the invention, the method of operating a hearing device, comprises at least one of the following steps:
communicating MIDI data; loading MIDI data; storing MIDI data; interpreting MIDI data; generating MIDI data;
wherein MIDI stands for Musical Instrument Digital Interface.
In one embodiment, the method comprises the step of generating sound in said hearing device based on said interpretation of said MIDI data.
The advantages of the methods correspond to the advantages of corresponding hearing devices.
Further preferred embodiments and advantages emerge from the dependent claims and the figures.
BRIEF DESCRIPTION OF THE DRAWINGS
Below, the invention is illustrated in more detail by means of embodiments of the invention and the included drawings. The figures show:
FIG. 1 a block diagram of a first hearing device;
FIG. 2 a block diagram of a second hearing device.
The reference symbols used in the figures and their meaning are summarized in the list of reference symbols. Generally, alike or alike-functioning parts are given the same reference symbols. The described embodiments are meant as examples and shall not confine the invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a block diagram of a hearing device 1 , e.g., a hearing aid, a hearing protection device, a communication device or the like. It comprises an input transducer 3 , e.g., as indicated in FIG. 1 , a microphone for converting incoming sound 5 into an electrical signal, which is fed into a signal processor 4 , in which the signal can be processed and amplified. It is, of course, possible to foresee a telephone coil as an input transducer. An amplification may take place in a separate amplifier. The processed amplified signal is then, in an output transducer 2 , converted into a signal 6 to be perceived by the user of the hearing device. When, e.g., the transducer 2 is a loudspeaker, the signal 6 is an acoustical wave. In case of an implanted device 1 , the signal 6 can be an electrical signal.
The device 1 of FIG. 1 furthermore comprises a user interface 12 , through which the hearing device user may communicate with the hearing device 1 . It may comprise a volume wheel 13 and a program change button 14 . A controller 18 , which controls said signal processor (DSP) 4 , can receive input from said user interface 12 . Said controller 18 can communicate with the signal processor via MIDI data 20 . For example, a sound signal to be played to the user when the user selects a certain program (via said program change button 14 ), can be encoded in such MIDI data 20 . The DSP 4 can function as a converter for converting MIDI data 20 into sound, that sound is to be perceived by the user after it has been converted in output transducer 2 . For example, the MIDI data 20 instruct the DSP 4 to play a certain melody by passing to the DSP 4 the information, which sound wave to use, and for which duration and at which volume (loudness) to generate sound at which pitch. Also other instructions to the DSP 4 can be encoded in the MIDI data 20 .
The embodiment of FIG. 1 exemplifies a rather internal use of MID data within a hearing device.
FIG. 2 shows a hearing device 1 , which can communicate MIDI data 20 with external devices. In addition to an input transducer 3 , the hearing device 1 comprises an infrared interface 10 and a bluetooth interface 11 for receiving external input and possibly send output, e.g., MIDI data, to an external device. Bluetooth is a well-known wireless standard in computing and mobile communication. Other interfaces, e.g., a radio frequency/FM interface, may be provided, and some interfaces may be embodied as an add-on to the hearing device. A multiplexer 9 is provided for selecting, which signals to forward to a DSP 4 and a controller 18 , respectively. A user interface 12 like the one in the embodiment of FIG. 1 may also be provided.
The hearing device 1 can receive MIDI data 20 , as indicated in FIG. 2 from a mobile phone 30 , from a computer, or from another device via said infrared interface 10 . The hearing device 1 can receive MIDI data 20 , as indicated in FIG. 2 from a computer 40 , from a mobile phone, or from another device via said Bluetooth interface 11 . The computer may be adapted to be connected to the world wide web 50 , from where suitable MIDI data could be loaded into the computer and then communicated to the hearing device 1 .
Of course, besides wireless connections, the hearing device 1 may also have the possibility to have a wire-bound connection for communicating with external or added-on devices.
The controller 18 not only gives instructions to the DSP 4 , but has associated a MIDI data memory 16 for storing MIDI data 20 , and a sound memory 17 , in which sound data like digitally sampled sounds can be stored. A sound generator 8 is provided, which is controlled by controller 18 and can access said sound memory 17 . In the DSP 4 , sound generated by the sound generator 8 can be processed and, after amplification, fed to the output transducer 2 .
The MIDI data memory 16 may store externally-loaded MIDI data or MIDI data generated in the hearing device 1 . The sound memory 17 may store externally-loaded sounds, e.g., loaded via MIDI DownLoadable Sounds (DLS) data, or may store pre-programmed sounds (pre-stored sounds). The memories 16 and 17 can, of course be realized in one single memory and/or be integrated, e.g., in the controller 18 .
The arrows indicating the interconnection of the various parts of the hearing devices in FIGS. 1 and 2 may partially be realized as bidirectional interconnections, even if in FIGS. 1 and/or 2 the corresponding arrow may only be unidirectional.
One of many ways to make use of MIDI data 20 in the hearing device 1 may be to load via one of the interfaces 10 , 11 MIDI data describing a telephone ring tone and store the MIDI data in the MIDI data memory 16 and recall said MIDI data when the mobile phone 30 informs the hearing device 1 that a telephone call is arriving. The ring tone (music and possibly also sound) encoded in the MIDI data is thereupon played to the hearing device user by the sound generator 8 via the DSP 4 and the transducer 2 .
Another use of MIDI data 20 in the hearing device 20 is to receive via one of the interfaces 10 , 11 from, e.g., the computer 40 , MIDI data, which describe a piece of music the user wants to listen to. The sound memory 17 may contain (pre-stored) sounds according to the General MIDI standard (GM). The controller 18 instructs the sound generator to generate notes according to the MIDI data 20 with sounds from the sound memory 17 having the General MIDI sound number given in the MIDI data 20 . This way, musical pieces can be generated, according to loaded MIDI instructions, fully within the hearing device 1 . Of course, it is also possible to load all MIDI data for the piece of music first, store them in the MIDI data memory 16 , and play them later, e.g., upon a start signal provided by the user through a user interface, like the user interface 12 in FIG. 1 .
Another use of MIDI data 20 in the hearing device 20 is to load via one of the interfaces 10 , 11 MIDI data 20 , which contain speech sounds, e.g., when the MIDI data 20 are MIDI DLS data. For example, to different (musical) keys (C4, is C#4, . . . ) a sampled sound of different vowels and consonants can be assigned, or even syllables, full words or sentences. By means of sounds of such a sound set, the user could be informed about the status of a hearing device's battery or about some user manipulation of a user interface or the like in form of speech messages like “battery is low, please insert a new battery soon” or “volume is adjusted to 8”. The text would be encoded in sequences of musical keys, with durations, loudness volumes and so on, just like a piece of music, in MIDI data.
Many further useful uses of MIDI data in a hearing device are possible.
LIST OF REFERENCE SYMBOLS
1 hearing device
2 transducer, output transducer, loudspeaker, receiver
3 transducer, input transducer, microphone
4 signal processor, digital signal processor, DSP
5 sound, incoming sound, incoming audio signal
6 signals to be perceived by the user, sound, outgoing sound
8 sound generator
9 multiplexer
10 infrared interface
11 Bluetooth interface
12 user interface, set of controls
13 control, volume wheel
14 control, program change knob
16 MIDI data memory
17 sound memory
18 controller, processor chip
20 MIDI data, MIDI file, MIDI message
30 cellular phone, mobile phone
40 computer, personal computer
50 worldwide web, www
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The hearing device is MIDI-compatible, wherein MIDI stands for Musical Instrument Digital Interface. The hearing device can be adapted to communicating and/or loading and/or storing and/or interpreting and/or generating data compliant with the MIDI Protocol, also referred to as MIDI messages. Acknowledge sounds of the hearing device an be controlled by MIDI data, or music can be played to a user of the hearing device based on MIDI data. The hearing device can be a hearing aid, a headphone, an earphone, a hearing protection device, a communication device or the like.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of and claims priority benefit to U.S. patent application Ser. No. 12/929,826, filed Feb. 17, 2011, allowed, which is a continuation of U.S. Ser. No. 12/285,802, filed Oct. 14, 2008, now U.S. Pat. No. 7,952,449, which application in turn is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2008-0181883, filed Jul. 11, 2008, the entire contents of which are incorporated herein by reference.
BACKGROUND
[0002] 1. Field
[0003] The embodiment discussed herein is directed to a coaxial connector for transmitting an electric signal.
[0004] 2. Description of the Related Art
[0005] Generally, a coaxial connector is used to connect signal lines for transmitting a high-speed (radio frequency) electric signal. An inner conductor serving as a signal line is provided in a central part of a coaxial connector, and an outer conductor serving as a grounding line is provided to surround the inner conductor. A dielectric material is filled between the inner conductor and the outer conductor. An outer diameter of the inner conductor and an inner diameter of the outer conductor are set to predetermined diameters so as to match a specific impedance (for example, 50Ω).
[0006] In the above-mentioned coaxial connector, there is a cutoff frequency fc at which a signal having a frequency higher than a fixed frequency cannot be transmitted. The cutoff frequency fc is determined by the outer diameter of the inner conductor, the inner diameter of the outer conductor, and a specific dielectric constant of the dielectric material filled between the inner conductor and the outer conductor. The cutoff frequency fc becomes higher as the diameters become smaller and the specific dielectric constant becomes lower. Accordingly, in order to transmit a radio frequency signal, it is necessary to make the diameter of the coaxial connector small and make the specific dielectric constant of the filled dielectric material low. Generally, in order to obtain a radio frequency transmission band of about more than 60 GHz, the outer diameter of the inner conductor is reduced to about 1 mm and an air (∈r=1.0) is used as a dielectric material.
[0007] In recent years, miniaturization and speeding up have progressed in measuring instruments and optical transmission and reception devices that handle a high-speed (radio frequency) electric signal. With such a progress, there is a demand for miniaturizing coaxial connectors used for those devices are required. Although connectors having a screw-type connecting part, which are represented by a 2.92 mm connector or a 1.85 mm connector, were in popular use, connectors having a push-on type connecting part, such as an SMP connector or an SMPM connector, have become popular with the demand for miniaturization (for example, refer to Non-Patent Document 1).
[0008] In many cases, a coaxial connector used for connection between measuring instrument or devices is provided with functions such as a DC block or a frequency filter. The DC block is provided for interrupting a direct current component and to transmit only an alternating current (AC) signal. The frequency filter is provided for attenuating a specific frequency component of a signal.
[0009] Specifically, the DC block and the frequency filter are formed by inserting a capacitor in the middle of the inner conductor. For example, it is suggested to divide the inner conductor into a first inner conductor and a second inner conductor and connecting the first and second inner conductors with two flat-plate capacitors located therebetween in series (for example, refer to Patent Document 1). Additionally, it is suggested to divide the inner conductor into a first inner conductor and a second inner conductor while forming surfaces parallel to the axis and connecting the first and second inner conductors with a dielectric material located therebetween (for example, refer to Patent Document 2).
[0010] According to the structures of the DC blocks, a strength of a connecting part (a part where the DC block is formed) between the first inner conductor and the second inner conductor is small, and the connecting part may be damaged due to a thermal stress of the inner conductor or the like. Thus, it is suggested to provide a stress relaxation mechanism for absorbing and relaxing a stress in the axial direction (for example, refer to Patent Document 3)
[0011] Patent Document 1: U.S. Pat. No. 6,496,353
[0012] Patent Document 2: U.S. Pat. No. 7,180,392
[0013] Patent Document 3: U.S. Pat. No. 5,576,675
[0014] Non-Patent Document 1: U.S. military standard MIL_STD — 348A
[0015] If a capacitor is interposed in the middle of the inner conductor as mentioned above, it is difficult to equalize an impedance between the capacitor and the outer conductor and an impedance between the inner conductor and the outer conductor. That is, a distance between the inner conductor and the outer conductor, which is set to maintain a predetermined impedance, is changed at the portion of the capacitor, which results in a change in the impedance. Accordingly, an impedance mismatch occurs at the portion where the capacitor is provided, which causes degradation of a radio frequency signal transmission characteristic.
[0016] Accordingly, it is desirous to develop a small coaxial connector having a structure in which, even if a capacitor is inserted in a middle of an inner conductor, an impedance mismatch at a portion where the capacitor is provided is suppressed.
SUMMARY
[0017] There is provided a coaxial connector comprising: a first inner conductor and a second inner conductor; a capacitor connecting between the first inner conductor and the second inner conductor; an outer conductor extending along and surrounding the first inner conductor, the second inner conductor, and the capacitor; a first dielectric material filled in a gap between the outer conductor and the first and second inner conductors; a support member supporting the first and second inner conductors with respect to the outer conductor; and a second dielectric material for impedance matching provided between the capacitor and the outer conductor.
[0018] There is provided a radio frequency signal transmission method for transmitting a radio frequency signal through an inner conductor serving as a signal line, the radio frequency signal transmission method comprising: causing the radio frequency signal to be input to and propagate through the inner conductor, an impedance between the inner conductor and an outer conductor serving as a grounding line being adjusted to a predetermined impedance; and causing a component of the radio frequency signal to propagate through a capacitor provided in a middle of the inner conductor, an impedance at a portion of the capacitor installed being adjusted to match said predetermined impedance by a dielectric material provided around said capacitor.
[0019] Additional objects and advantages of the embodiment will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The object and advantages of the embodiment will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims.
[0020] It is to be understood that both the foregoing general description and the following detailed description are exemplary explanatory only and are not restrictive of the invention, as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 is a cross-sectional view of a coaxial connector having a basic structure;
[0022] FIG. 2 is a circuit diagram of an equivalent circuit of a transmission path of the coaxial connector illustrated in FIG. 1 ;
[0023] FIG. 3 is a cross-sectional view of a coaxial connector according to a first embodiment;
[0024] FIG. 4 is a cross-sectional view of a first variation of the coaxial connector illustrated in FIG. 3 ;
[0025] FIG. 5 is a cross-sectional view of a second variation of the coaxial connector illustrated in FIG. 3 ;
[0026] FIG. 6 is a cross-sectional view of a third variation of the coaxial connector illustrated in FIG. 3 ;
[0027] FIG. 7 is an illustration indicating a manufacturing method of the coaxial connector illustrated in FIG. 6 ;
[0028] FIG. 8 is a graph indicating the impedance of a coaxial connector acquired by an electromagnetic field simulation;
[0029] FIG. 9 is a graph indicating a reflection characteristic and a transmission characteristic of a coaxial connector acquired by an electromagnetic field simulation;
[0030] FIG. 10 is a graph indicating actual measurement values of a reflection characteristic and a transmission characteristic of a coaxial connector;
[0031] FIG. 11 is a cross-sectional view of a coaxial connector according to a second embodiment;
[0032] FIG. 12 is a cross-sectional view of a coaxial connector according to a third embodiment;
[0033] FIG. 13 is a cross-sectional view of a coaxial connector according to a fourth embodiment;
[0034] FIG. 14A is a cross-sectional view of a connector when the structure of the coaxial connector illustrated in FIG. 6 is applied to a connector having a fitting part (connecting part) of a push-type in a state before the connector is connected to another connector; and
[0035] FIG. 14B is a cross-sectional view of the connector shown in FIG. 14A in a state after the connector is connected to another connector.
DESCRIPTION OF EMBODIMENTS
[0036] Preferred embodiments of the present invention will be explained with reference to the accompanying drawings.
[0037] A description will now be given, with reference to FIG. 1 , of a basic structure of a coaxial connector. The coaxial connector illustrated in FIG. 1 includes an inner conductor 2 , an outer conductor 4 surrounding the inner conductor 2 and a dielectric material 3 as a first dielectric material filled in a gap between the inner conductor 2 and the outer conductor 4 . The inner conductor 2 and the outer conductor 4 are formed of an electrically conductive metal such as a copper alloy. A predetermined gap is formed between the inner conductor 2 and the outer conductor 4 . It is preferable that a material having a small specific dielectric constant ∈r is filled in the gap. In many cases, a fluorocarbon resin is used as the material having a small specific dielectric constant ∈r to be filled in the gap. However, the gap may be an air gap. In such a case, an air in the gap corresponds to the material filled in the gap. Here, it is assumed that an air is filled in the gap between the inner conductor 2 and the outer conductor 4 , and an air is filled in the gap as the dielectric material 3 .
[0038] The inner conductor 2 is divided into two portions, i.e., an inner conductor 2 A and an inner conductor 2 B, and a capacitor 6 is inserted between the inner conductor 2 A and the inner conductor 2 B. The capacitor 6 is connected and fixed to the inner conductor 2 A and the inner conductor 2 B by a joining material such as a solder 8 . Although a laminated ceramic chip capacitor, which is formed as a mount part to be mounted to a generally used substrate, is used as the capacitor 6 , the capacitor 6 is not limited to such a chip capacitor. It should be noted that, in the example illustrated in FIG. 1 , the inner conductors 2 A and 2 B are mechanically connected to each other by joining and fixing them with the capacitor 6 interposed therebetween. Thus, a connecting strength of the inner conductors 2 A and 2 B is equal to a connecting strength of the solder 8 .
[0039] The inner conductor 2 into which the capacitor 6 is incorporated is fixed to the outer conductor 4 via a support member 10 . It is preferable to use a resin as a material to form the support member 10 . Since a specific dielectric constant ∈r of a resin is generally 2 to 4 (∈r=2 to 4), the specific dielectric constant ∈r of the portion where the support member 10 is provided is larger than that of portions (air gap) other than the portion where the support member 10 is provided. Thus, impedance matching is achieved by enlarging the gap by providing grooves to the inner conductor 2 and the outer conductor 4 where the support member 10 is provided. It should be noted that the grooves serve as engaging portions for attaching the support member 10 to the inner conductor 2 and the outer conductor 4 .
[0040] A circuit illustrated in FIG. 2 is an equivalent circuit of a signal transmission path in the structure of the coaxial connector illustrated in FIG. 1 . Because outer diameters of internal electrodes of the capacitor 6 are smaller than an outer diameter of the inner conductor 2 , a width of the gap between the capacitor 6 and the outer conductor 4 is larger than a width of a gap in other portions. Thus, a parasitic capacitance (a capacitor Cp of FIG. 2 ) generated by the capacitor 6 being provided is smaller than an electrostatic capacitance (a capacitor Cn of FIG. 2 ) generated between the inner conductor 2 and the outer conductor 4 .
[0041] Here, on the assumption that the equivalent circuit illustrated in FIG. 2 is a single distribution constant circuit, an impedance Z thereof is represented by Z=(L/C) 1/2 where L is an inductance per unit length and C is a capacitance per unit length. According to the equation, the inductance dependency is large, that is, it is regarded that an inductance Lp is increased as a capacitance Cp is decreased, and, thus, the impedance Z is increased. That is, the impedance in the portion where the capacitor 6 is provided is larger than impedances of other portions, which causes generation of an impedance mismatch.
[0042] If an impedance mismatch occurs as mentioned above, a reflection of a radio frequency signal occurs in that portion, which results in a degradation of a radio frequency signal transmission characteristic. Thus, the impedance of the portion where the capacitor 6 is provided is matched by adjusting the parasitic capacitance Cp of the capacitor 6 so as to improve the radio frequency signal transmission characteristic.
[0043] FIG. 3 is a cross-sectional view of a coaxial connector according to a first embodiment. A basic structure of the coaxial connector 20 illustrated in FIG. 3 is the same as that of the coaxial connector illustrated in FIG. 1 , and parts that are the same as the parts illustrated in FIG. 1 are given the same reference numerals and descriptions thereof will be omitted.
[0044] In FIG. 3 , a dielectric material ring 22 as a second dielectric material is attached to an outer circumference of the capacitor 6 . The dielectric material ring 22 serves as a material for matching the parasitic capacitance Cp of the capacitor 6 . The dielectric material ring 22 can be formed of any material having an insulation property and a specific dielectric constant larger than the specific dielectric constant of the dielectric material 3 (in this case, larger than the specific dielectric material ∈r=1 of air). For example, the dielectric material ring 22 may be formed of the same fluorocarbon resin as the support member 10 or a rubber such as a fluorocarbon rubber. Although the dielectric material ring 22 is described as a ring, the same effect can be obtained if it is a semi-circular shape or a shape to be applied partially around the capacitor 6 .
[0045] By arranging the dielectric material ring 22 around the capacitor 6 , the parasitism capacitance Cp generated between the capacitor 6 and the outer conductor 4 can be increased. Therefore, the impedance matching can be achieved in the portion where the capacitor 6 is provided. That is, the impedance can be constant (for example, a specific impedance of 50Ω) also in the portion where the capacitor 6 is provided by arranging the dielectric material ring 22 having a large specific dielectric constant ∈r around the capacitor 6 , thereby suppressing reflection of a radio frequency signal. As a result, even if the capacitor 6 is provided in the middle of the inner conductor 2 , reflection of a radio frequency due to an impedance change can be reduced, and the radio frequency signal transmission characteristic of the coaxial connector 20 can be maintained well.
[0046] It should be noted that, like a coaxial connector 20 A illustrated in FIG. 4 , concave portions of a size almost equal to the outer configuration of the capacitor 6 may be formed in the end surfaces of the inner conductors 2 A and 2 B so that the capacitor 6 is joined to the inner conductors 2 A and 2 B by a solder or the like after fitting the capacitor 6 in the concave portions. Thereby, strength of the connecting part by the capacitor 6 can be increased. The concave portions may be recesses or notches of a channel shape, or may be formed by members connected to the inner conductors 2 A and 2 B.
[0047] Here, if the outer diameter of the capacitor 6 is close to or larger than the outer diameter of the inner conductors 2 A and 2 B and the end surfaces of the inner conductors 2 A and 2 B do not have a sufficient size to form the concave portions, the outer diameter of the inner conductors 2 A and 2 B may be increased so as to form the large diameter portions like a coaxial connector illustrated in FIG. 5 . In such a case, it is necessary to form concave portion 4 a on the inner surface of the outer conductor 4 at a position facing the large diameter portions having a large diameter near the end surfaces of the inner conductors 2 A and 2 B. That is, it is necessary to set the impedance to a desirable value by a distance between the outer conductor 4 and each of the inner conductors 2 A and 2 B even in the portions having the large diameter near the end surfaces of the inner conductors 2 A and 2 B.
[0048] Further, like a coaxial connector 20 C illustrated in FIG. 6 , grooves formed in the inner surface of the outer conductor 4 into which the support members 10 are fit and the above-mentioned concave portion 4 a for impedance matching may be formed as a single groove or concave portion by shifting the support members 10 toward the connecting part of the capacitor 6 . Thereby, the portion where the capacitor 6 is provided can be made small, which permits the entire coaxial connector 20 C to be made small. Additionally, since the configuration of the inner surface of the outer conductor 4 can be simplified, cutting work of the outer conductor 4 can be performed easily.
[0049] A description will now be given, with reference to FIG. 7 , of an example of an assembling method of the coaxial connector 20 C illustrated in FIG. 6 . According to the assembling method indicated in FIG. 7 , the outer conductor 4 is divided into two pieces, outer conductors 4 A and 4 B, so that the outer conductors 4 A and 4 B are fit to each other to be a single piece forming the outer conductor 4 . Although a description will be given of a fitting method of the outer conductors 4 A and 4 B using press-fitting here, the assembling method is not limited to the press-fitting and may include fitting by screw and electrical or physical connection.
[0050] First, as illustrated in FIG. 7 -( a ), the capacitor 6 on which the dielectric material ring 22 is fit is inserted into the concave portions of the end surfaces of the inner conductors 2 A and 2 B, and fixed by solder or the like so as to form an inner conductor assembly 2 C. Then, the support members 10 are attached to the inner conductors 2 A and 2 B of the inner conductor assembly 2 C, respectively. Thereafter, as illustrated in FIG. 7 -( b ), the inner conductor assembly 2 C is assembled to the outer conductor 4 B so that the support member 10 fits in the concave portion 4 a of the outer conductor 4 B. Then, as illustrated in FIG. 7 -( c ), the outer conductor 4 A is press-fitted into the outer conductor 4 B. Thereby, as illustrated in FIG. 7 -( d ), the outer conductor 4 is formed and the inner conductor assembly 2 C is fixed inside the outer conductor 4 in a state where the support members 10 are fixed to the concave portion 4 a in the inner surface of the outer conductor 4 .
[0051] As mentioned above, the small-size coaxial connector 20 C can be assembled very easily by press-fitting the outer conductor 4 A into the outer conductor 4 B after inserting the inner conductor assembly 2 C into the outer conductor 4 B. The assembling method by press-fitting the two-divided outer conductors can be applied to other coaxial connectors mentioned above, and is also applicable to coaxial connectors explained below.
[0052] FIG. 8 is a graph indicating the impedance acquired by an electromagnetic field simulation using the coaxial connector 20 C of the structure illustrated in FIG. 6 as a model. In the graph of FIG. 8 , a solid line indicates the impedance of the coaxial connector 20 C provided with the dielectric material ring 22 , and a dashed line indicates the impedance of a coaxial connector, which is not provided with the dielectric material ring 22 .
[0053] As apparent from the graph of FIG. 8 , an impedance change at the portion where the capacitor 6 is provided is suppressed by providing the dielectric material ring 22 . That is, by providing the dielectric material ring 22 , impedance matching can be achieved and an impedance mismatch can be suppressed.
[0054] FIG. 9 is a graph indicating a reflection characteristic S 11 and a transmission characteristic S 21 acquired by an electromagnetic filed simulation using the coaxial connector 2 C of the structure illustrated in FIG. 6 as a model. In the graph of FIG. 9 , solid lines indicate the reflection characteristic S 11 and the transmission characteristic S 21 of the coaxial connector 20 C provided with the dielectric material ring 22 , and dashed lines indicate the reflection characteristic S 11 and the transmission characteristic S 21 of a coaxial connector, which is not provided with the dielectric material ring 22 . The two curves (solid line and dashed line) indicated in a lower part of the graph indicate the reflection characteristic S 11 , and the generally flat two curves (solid line and dashed line) indicated in an upper part of the graph indicate the transmission characteristic S 21 .
[0055] The transmission characteristic S 21 of the coaxial connector, which is not provided with the dielectric material ring 22 is indicated by the dashed line, which indicates that the transmission characteristic S 21 decreases as the frequency increases. On the other hand, the transmission characteristic S 21 of the coaxial connector 20 C provided with the dielectric material ring 22 is almost zero over the entire band, which indicates that there is almost no transmission loss. Thus, it can be appreciated that the transmission characteristic S 21 in the radio frequency band is improved by providing the dielectric material ring 22 .
[0056] The reflection characteristic S 11 of the coaxial connector, which is not provided with the dielectric material ring 22 , indicates that it is below −20 dB in the portion where the frequency is low but reflection increases higher than −20 dB at a frequency exceeding 20 GHz. On the other hand, the reflection characteristic S 11 of the coaxial connector 20 C provided with the dielectric material ring 22 is below −20 dB in a radio frequency band from a low frequency to about 55 GHz. Thus, it can be appreciated that the reflection characteristic S 11 in the radio frequency band is greatly improved by providing the dielectric material ring 22 .
[0057] The coaxial connector 20 C of the structure illustrated in FIG. 6 was fabricated and the reflection characteristic S 11 and the transmission characteristic S 21 were measured, and a result indicated in the graph of FIG. 10 was obtained. It can be appreciated from the graph that the reflection characteristic S 11 was below −20 dB in a radio frequency band from a low frequency to about 55 GHz, which indicates that the reflection characteristic S 11 was greatly improved. On the other hand, since the transmission characteristic S 21 was maintained at a value of almost zero to the frequency of about 60 GHz, it was confirmed that a good transmission characteristic was maintained also in a radio frequency band.
[0058] A description will now be given, with reference to FIG. 11 of a coaxial connector according to a second embodiment. In FIG. 11 , parts that are the same as the parts illustrated in FIG. 6 and FIG. 7 are given the same reference numerals, and descriptions thereof will be omitted.
[0059] Although the coaxial connector 20 D according to the second embodiment has the same structure as the above-mentioned coaxial connector 20 C, it differs in that the dielectric material ring 22 is replaced by a modified dielectric material ring 24 . The modified dielectric material ring 24 does not have a shape to be attached to an outer circumference of the capacitor 6 , but is made in a shape to cover circumferences of the inner conductors 2 A and 2 B. The length of the modified dielectric material ring 24 is equal to a distance between the support members 10 , and opposite ends of the modified dielectric material ring 24 are brought into contact with the respective support members 10 .
[0060] The thickness of the modified dielectric material ring 24 is set so that impedances between sections B, C and D are equal to the impedance of a section A. Specifically, the thickness of the modified dielectric material ring 24 in the section C is small and the thickness of the modified dielectric material ring 24 in the section D is large so that the portion of the modified dielectric ring 24 in the section D forms a protruding part. Although the protruding part of the modified dielectric material ring 24 protrudes outwardly, it may protrude inwardly so as to maintain a desired thickness. Also the cross-section of the modified dielectric material ring 24 is not always required to be a square shape as illustrated in FIG. 11 . The modified dielectric material ring 24 can be various shapes in order to achieve impedance matching.
[0061] According to the present embodiment, the modified dielectric material ring 24 is interposed between the support members 10 , and the joint part between the inner conductors 2 A and 2 B can be strengthened by the modified dielectric material ring 24 . That is, if a force to compress the capacitor 6 is applied to the inner conductors 2 A and 2 B when connecting and disconnecting the coaxial connector, a portion of the force can be absorbed by the modified dielectric material ring 24 , which can reduce a force applied to the capacitor 6 and the joint part.
[0062] A description will be given below, with reference to FIG. 12 , of a coaxial connector according to a third embodiment. In FIG. 12 , parts that are the same as the parts illustrated in FIG. 6 and FIG. 7 are given the same reference numerals, and descriptions thereof will be omitted.
[0063] Although the coaxial connector 20 E according to the third embodiment has the same structure as the above-mentioned coaxial connector 20 C, it differs in that an adhesive 26 is provided to an outer circumference of the capacitor 6 instead of the dielectric material ring 22 . By using a resin such as, for example, an epoxy resin as for the adhesive 26 , an electrostatic capacitance can be adjusted to achieve the impedance matching as the same as the dielectric material ring 22 .
[0064] The adhesive 26 may be provided by applying onto the outer circumference of the capacitor 6 and cured, or may be provided on the circumference of the capacitor 6 over an entire area between the inner conductors 2 A and 2 B. If the adhesive 26 is provided to only the outer circumference of the capacitor 6 , the capacitor 6 can be strengthened by the adhesive 26 . If the adhesive 26 is provided to cover the outer circumference of the capacitor 6 and the joint part of the capacitor 6 , the capacitor 6 is strengthened and also the joint part is strengthened.
[0065] A description will be given below, with reference to FIG. 13 , of a coaxial connector according to a fourth embodiment. In FIG. 13 , parts that are the same as the parts illustrated in FIG. 11 and FIG. 12 are given the same reference numerals, and descriptions thereof will be omitted.
[0066] The coaxial connector 20 F according to the fourth embodiment is a combination of the modified dielectric material ring 24 illustrated in FIG. 11 and the adhesive 26 illustrated in FIG. 12 . The adhesive 26 is filled in a space between the modified dielectric material ring 24 and the outer circumference of the capacitor 6 , and the joint part of the capacitor 6 is strengthened strongly by the modified dielectric material ring 24 and the adhesive 26 .
[0067] The structures of the above-mentioned coaxial connectors 20 to 20 F can be used for a connector having a fitting part (joint part) of a push-on type such as SMP or SMPM. The specifications of SMP and SMPM are provided in U.S. military standard MIL_STD — 348A. FIGS. 14A and 14B are cross-sectional views of a coaxial connector when the structure of the coaxial connector 20 C illustrated in FIG. 6 as an example is applied to a connector 30 having a fitting part (joint part) 30 a of a push-on type. FIG. 14A illustrates a state before the connector 30 is connected to another connector 32 . FIG. 14B illustrates a state after the connector 30 is connected to the connector 32 .
[0068] In FIGS. 14A and 14B , a fitting part (joint part) 30 a is formed on each of opposite ends of the connector 30 having the structure of the coaxial connector 20 C. The fitting part (joint part) 30 a is configured to be fitted to a fitting part (joint part) 32 a of the connector 32 . The connector 30 can be connected to the connector 32 quickly and easily by placing the fitting part 30 a of the connector 30 to opposite to the fitting part 32 a of the connector 32 and pushing the fitting part 30 a into the fitting part 32 a.
[0069] It should be noted that, by using the above-mentioned coaxial connectors 20 to 20 F, a radio frequency signal transmission method to transmit a radio frequency signal while suppressing a signal degradation can be achieved. That is, when transmitting a radio frequency signal through a signal transmission path in which the outer conductor 4 as a grounding line is provided around the inner conductor 2 as a signal line, a method of transmitting a radio frequency signal while maintaining excellent reflection characteristic and transmission characteristic to suppress a signal degradation can be achieved.
[0070] In the radio frequency transmission method, first, a radio frequency signal is input to and caused to propagate through the inner conductor 2 as a signal line provided with a predetermined impedance. Then, the radio frequency signal is caused to propagate further through the capacitor 6 inserted in the middle of the inner conductor 2 . While the radio frequency signal propagates through the capacitor 6 , a component of the radio frequency signal is limited by the capacitor 6 . That is, a DC component of the radio frequency signal is removed by the capacitor 6 , or only a frequency component of a certain band is removed by the capacitor 6 . Because a dielectric material (the dielectric material ring 22 , the modified dielectric material ring 24 , the adhesive 26 ) is provided on the outer circumference of the capacitor 6 and the impedance of the portion where the capacitor 6 is provided is matched, a reflection of the radio frequency signal hardly occurs and the radio frequency signal is transmitted without attenuating in the portion where the capacitor 6 is provided.
[0071] All examples and conditional language recited herein are intended for pedagogical purposes to aid the reader in understanding the principles of the invention and the concepts contributed by the inventor to furthering the art, and are to be construed a being without limitation to such specifically recited examples and conditions, nor does the organization of such examples in the specification relates to a showing of the superiority and inferiority of the invention. Although the embodiment(s) of the present invention (s) has(have) been described in detail, it should be understood that the various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention.
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A coaxial connector that includes: a first inner conductor and a second inner conductor; a capacitor that is electrically coupled to the first inner conductor and the second inner conductor; an outer conductor that surrounds the first and second inner conductors, and the capacitor; a first support member that fixes the first inner conductor to the outer conductor; a second support member that fixes the second inner conductor to the outer conductor; a first dielectric material that is provided between the outer conductor and the first inner conductor and between the outer conductor and the second inner conductor, and a second dielectric material that is provided between the outer conductor and the capacitor.
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This application is a continuation, of application Ser. No. 07/738,517 filed Jul. 31, 1991, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention describes an efficient method for assaying nucleic acids employing fluorescence.
2. Related Art
In medical and biological fields, a DNA or RNA probe complexed with a radioactive isotope has been employed as a means of detecting nucleic acids. This technique comprises hybridizing the labeled probe with a target nucleic acid, followed by detecting the target nucleic acid by autoradiography. This isotope method has numerous drawbacks which are serious obstacles to the application and development of this technology. The drawbacks of the isotope method are as follows:
(a) The nucleic acid hybridization method lacks spatial resolution sufficient to reveal the relative positional relationship between contiguous signals.
(b) Experimental procedures using isotope can only be performed in isotope laboratories equipped with special facilities. This hinders the application of the hybridization method, particularly for clinical applications.
(c) Use of isotope is dangerous for laboratory workers even under controlled laboratory conditions. In addition, a danger for non-laboratory workers also exists because of radioactive wastes.
(d) An extended period (several weeks to several months) may be required for detection, such that application to rapid clinical diagnosis is difficult.
(e) Radioactivity decays with a definite half-life period. Accordingly, experiments must be scheduled around a purchase date of isotope. If the schedule chart is slightly altered, there is a danger of wasting isotope or experimental results on a large scale.
(f) To enhance detection sensitivity, significant quantities of radioactivity must be incorporated in a nucleic acid probe. However, this highly radioactive nucleic acid is unstable and easily suffers from radioactive disintegration.
(g) In general, isotope is extremely expensive. This prevents general use of the hybridization method.
In view of such drawbacks, DNA or RNA labeling methods in place of employing radioactive isotope have been developed. For example, BLU GENE KIT™, commercially available from Bethesda Research Laboratories Inc. (BRL Inc.), is known. Additionally, "Nucleic Acid Probe And Use Thereof" is disclosed in Japanese Patent Application Laid-Open No. 60-226888.
However, these techniques do not eliminate all of the drawbacks described above. In particular, detection sensitivity is not comparable to that of the isotope method. In the above labeling, the detection sensitivity is "10 -12 g DNA," slightly inferior to the "10 -13 g DNA" of the isotope method.
An object of the present invention is to provide a method for assaying nucleic acids which eliminates the drawbacks of the isotope method and which also provides excellent detection sensitivity.
SUMMARY OF THE INVENTION
The present invention provides a method for assaying nucleic acids or similar compounds comprising binding phosphatase to a sample (e.g. nucleic acids), reacting the phosphatase with 3-hydroxy-2-naphthoic acid-2'-phenyl anilide phosphate, irradiating the reaction products with an excited light, and detecting the fluorescence emitting therefrom.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 shows the test results obtained in Example 1.
FIG. 2 shows the test results obtained in Example 1.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
It is preferable in the present invention to employ a 3-hydroxy-2-naphthoic acid-2'-phenyl anilide phosphate to which a phosphatase is bound. Examples of phosphatases include alkali phosphatase and acid phosphatase.
Sample compounds which can be detected by the method of the present invention comprise nucleic acid (DNA or RNA), protein, and immunological detection of a chemical compound using antibody.
An example of a 3-hydroxy-2-naphthoic acid-2'-phenyl anilide phosphate includes the basic skeleton shown by Formula (I). ##STR1##
In the assay method according to the present invention, a 3-hydroxy-2-naphthoic acid-2'-phenyl anilide phosphate is reacted with a phosphatase, followed by irradiation with an excited light, whereby the dephosphating product of the 3-hydroxy-2-naphthoic acid-2'-phenyl anilide phosphate emits fluorescence. The emitted fluorescence can then be detected.
The 3-hydroxy-2-naphthoic acid-2'-phenyl anilide phosphate is reacted with a phosphatase combined with a sample (e.g. nucleic acids) on a membrane filter made of nylon. This produces a dephosphating product of the 3-hydroxy-2-naphthoic acid-2'-phenyl anilide phosphate, which adheres to the nylon membrane filter and displays fluorescence. The fluorescence and the pattern thereof (spots, and bands produced by electrophoresis) are then detected by irradiation with an excited light.
In the present invention, intense fluorescence can be obtained by employing a 3-hydroxy-2-naphthoic acid-2'-phenyl anilide phosphate to improve detection sensitivity; for example, 3×10 -14 g (0.03 pg) of DNA is detectable. No isotope is used in this method, and therefore, the drawbacks of the prior art are eliminated.
Thus, a method for assaying nucleic acids or similar compounds which provides excellent detection sensitivity is described. Further, the present invention provides the dephosphating product of a 3-hydroxy-2-naphthoic acid-2'-phenyl anilide phosphate in a high yield.
EXAMPLES
Example 1
To verify the effectiveness of a 3-hydroxy-2-naphthoic acid-2'-phenyl anilide phosphate as a probe for nucleic acids, the DNA Labeling and Detection Kit of Boehringer Mannheim and 3-hydroxy-2-naphthoic acid-2'-phenyl anilide phosphate were used to detect DNA on a nylon membrane filter.
DNA was labeled with digoxigenin (Dig), diluted, and spotted on the nylon membrane filter. Each of the spots included 50 ng (50×10 -9 g) DNA of herring spermatozoa. 0.08 to 25 pg of Dig-labeled DNA was employed. The results are shown in FIG. 1. 0 pg in the Figure represents a blank test. Reference numeral 1 designates a carrier filter for a specimen of nucleic acids, and reference numeral 11 designates fluorescence sensitized portions. "+" represents detection of DNA; "±" represents that DNA cannot distinctly be detected; and "-" represents that DNA cannot be detected. The results shown in FIG. 1 demonstrate that DNA could satisfactorily be detected in 0.08 pg of sample.
Using a smaller amount of DNA, a second experiment was conducted on 0.015 to 0.25 pg of Dig-labeled DNA in the same manner as described above. The test results are shown in FIG. 2. Satisfactory detection was obtained in a 0.03 pg (30 fg) sample.
In the first experiment, a conventional color development detection using azo-color, Fast Blue BB™ (of POLYSCIENCE, INC.) was employed. The detectable spot included 0.5 pg (0.5×10 -12 g) of DNA.
Example 2
A 3-hydroxy-2-naphthoic acid-2'-phenyl anilide phosphate was produced by the following processes.
According to the description of Enzyme Histochemistry, 5 g (0.027 mol) of 2-hydroxy-3-naphthoic acid, 40 ml of dehydrated xylene, and 0.023 mol of 3,5-dimethyl aniline were stirred in a 100 ml NASU flask provided with a Graham condenser at 80° C. for 10 minutes. 0.01 mol of phosphorous trichloride was then added to the flask and the resultant mixture was refluxed for 2 hours. Thereafter, the reaction solution was decanted in the hot state to skim the supernatant fluid. After cooling the fluid at 4° C., the fluid was filtered, and the precipitates thus obtained were eluted with xylene and then water. The precipitates were then neutralized with a 2% aqueous solution of sodium carbonate, and xylene was removed from the precipitates by boiling.
The precipitates were brought to pH 9 with a 2% aqueous solution of sodium carbonate, filtered, and cooled. The precipitates thus obtained were eluted with water and added to a 3% HCl solution, heated, filtered, and cooled. The precipitates were then washed with hot water and dried.
Next, the precipitates were recrystalized to produce 3-hydroxy-2-naphthoic acid-2'-biphenyl anilide, shown by the following formula (II). ##STR2##
1 g of this naphthol AS derivative was dissolved in 8 ml of pylidine. After stirring this solution at 0° C. for 30 minutes, phosphorus oxychloride (2.5 eg), cooled similarly, was added and stirred at 0° C. for 4 hours. Ice was then added to the solution to terminate the reaction.
The reaction product obtained was purified on a reverse phase silica gel column, followed by purification on a normal phase silica gel column, to produce 3-hydroxy-2-naphthoic acid-2'-phenyl anilide phosphate, shown by the following formula (III). ##STR3##
|
A method for assaying nucleic acids or similar compounds comprises binding a sample such as a nucleic acid to phosphatase; reacting the phosphatase with a 3-hydroxy-2-naphthoic acid-2'-phenyl anilide phosphate; irradiating the reaction product with an excited light; and detecting fluorescence emitted therefrom.
| 2
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CROSS-REFERENCE TO RELATED APPLICATIONS
Not Applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable.
BACKGROUND
The present invention relates to the preparation of co-salts of polyunsaturated fatty acids (PUFA) and another anion such as citrate, phosphate, lactate, fumarate, gluconate, carbonate, bicarbonate, malate, or other anions of common acids and the co-precipitated salts of the fatty acid and the anion. The present invention particularly relates to mixtures of monovalent and divalent metal salts rich in omega-3 and omega-6 fatty acids including eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), docosapentaenoic acid (DPA), eicosatetraenoic acid (ETA), heneicosatetraenoic acid (HPA), linoleic acid (LA), alpha linolenic acid (ALA) and arachidonic acid (ARA), in general known as omega-3 or -6 fatty acids.
Several salts, such as calcium, magnesium, copper, zinc, iron, manganese, potassium, ammonium, sodium, and several others have long been recognized as beneficial mineral nutrients for humans and certain companion animals and livestock, such as dogs, cats, cattle, horses, goats, pigs, birds, fish and others. Calcium is known to be essential for the maintaining of bones and teeth. It is also responsible for a normal heartbeat and helps regulate blood pressure. The divalent cation magnesium acts as a calcium antagonist at the cell membrane level which is necessary to maintain normal electrical potentials and to coordinate muscle contraction-relaxation responses. Additionally, magnesium has roles in energy metabolism as a required cofactor for enzymes that catalyze fatty acid synthesis, protein synthesis, and glucose metabolism. Copper is utilized as an enzyme for many biochemical reactions within the biological system of birds and mammals. Copper deficiency is known to cause anemia, bone disorders, neonatal ataxia, cardiovascular disorders, and many other maladies due to the inability of certain enzymes functioning properly.
Zinc also is essential for protein synthesis, integrity of cell membranes, maintenance of DNA and RNA, tissue growth and repair, wound healing, taste acuity, prostaglandin production, bone mineralization, proper thyroid function, blood clotting and cognitive functions.
A variety of omega-3 fatty acids have been identified as desirable for producing a diversity of nutritional and physiological benefits in humans and lower animals and accordingly have found value as nutritional supplements for a wide variety of animals. In certain animals, omega 3 fatty acids, for example, have been discovered to promote fertility, promote healthy skin and coat, reduce inflammation, and have other nutritional and physiological properties as well. In humans, it is believed that omega-3 fatty acids such as EPA and DHA support healthy cardiovascular function and are important for visual and neuronal development, support healthy blood levels of cholesterol, triglycerides and very low density lipoproteins, ease the inflammation associated with overuse of joints, and improve carbohydrate metabolism. The FDA allows the following claim to be added to products that contain omega-3:
“Supportive but not conclusive research shows that consumption of EPA and DHA omega-3 fatty acids may reduce the risk of coronary heart disease.”
In developing fetuses and children, omega-3 fatty acids have been shown to be necessary for the eyes, brain, and developing central nervous system. In adults, omega-3 fatty acids have been shown to maintain normal cardiovascular function and maintain healthy brain and immune system function.
It has also been shown that supplementing the diet of livestock with omega-3 fatty acids will alter the livestock fatty acid profile, so that, for example, feeding dairy cows and beef cattle a source of these unsaturated fatty acids will yield dairy and beef products for human consumption enriched with the beneficial polyunsaturated fatty acids (PUFA).
BRIEF SUMMARY
Generally salts of PUFA's have poor flow and processing characteristics. We have found that Ca and Mg salts of mixed anions comprised of a portion of omega fatty acids and a portion of at least one co-anion such as citrate and phosphate yield new chemical entities that are easy to handle during manufacture, and thus are easier to centrifuge, wash, and dry. Other salts of mixed cations, such as salts of Cu, Zn, Na, K, Mn Fe, Cu, NH 4 should also produce acceptable products. Other co-anions include, lactic acid, fumaric acid, malic acid, gluconic acid, acetic acid, ascorbic acid, aspartic acid, carbonic acid, sulfuric acid, phosphoric acid, formic acid, propionic acid, succinic acid, adipic acid, salicyclic acid, benzoic acid, phthalic acid, maleic acid, malonic acid, pyruvic acid, sorbic acid, caprylic acid, glutaric acid, pimelic acid, glucoheptanoic acid, glycerophosphoric acid, glutamic acid, glutathione, lecithin, phenylalanine, valine, leucine, isoleucine, threonine, methionine, lysine, arginine, histidine as well as others. The polyprotic acids may be present in their respective states of protonation. The co-salt products are free flowing and do not tend to agglomerate (cake) in storage. The co-salt may be crystalline. The resultant co-salt product will be easy to blend with other products to produce dietary supplements. These novel co-salt products may also tablet very well and may be added to current dietary supplement tablets.
Briefly stated, a co-salt of the claimed invention is comprised of at least a PUFA anion and at least one non-fatty acid co-anion. The co-anion is less waxy, less hydrophobic and more structurally rigid than the PUFA anion. The co-salt contains at least one cation which is ionically bonded with the PUFA anion and at least one co-anion.
The co-salt has an infrared spectra in which characteristic modes for the co-salt are off-set from corresponding characteristic modes for an admixture of the fatty acid salt and co-anion salt of the co-salt. Thus, for example, in a calcium phosphate co-salt, in which the co-salt has a calcium fatty acid salt component and a calcium phosphate component, the characteristic P—O stretching mode for the phosphate group in the co-salt is shifted relative to the characteristic P—O stretching mode for the phosphate group for an admixture of calcium fatty acid salt and calcium phosphate. Similarly, the COO − modes for the co-salt are off-set from the COO − modes for the calcium fatty acid salt.
The fatty acid anion and the co-anion vary in relative concentrations from about 10% fatty acid anion and 90% co-anion to about 90% fatty acid anion and 10% co-anion; and preferably the co-salt is about 40% to about 80% fatty acid anion and about 60% to about 20% co-anion. The cation is chosen from the group consisting of calcium, magnesium, zinc, iron, manganese, copper, potassium, sodium, ammonium, and combinations thereof.
At least one co-anion is chosen from the group consisting of citric acid, lactic acid, phosphoric acid, fumaric acid, malic acid, gluconic acid, acetic acid, ascorbic acid, aspartic acid, carbonic acid (as carbonate and bicarbonate), sulfuric acid (as both sulfate and bisulfate ions), phosphoric acid (monobasic, dibasic and tribasic), formic acid, propionic acid, succinic acid, adipic acid, salicyclic acid, benzoic acid, phthalic acid, maleic acid, malonic acid, pyruvic acid, sorbic acid, caprylic acid, glutaric acid, pimelic acid, glucoheptanoic acid, glycerophosphoric acid, glutamic acid, glutathione, lecithin, phenylalanine, valine, leucine, isoleucine, threonine, methionine, lysine, arginine, histidine, and the like and combinations thereof.
The fatty acid anion comprises at least one omega-3 or omega-6 fatty acid. The co-salt is least 5% by weight omega-3 or omega-6 fatty acids; and preferably, 15% to 95% omega-3 or omega-6 fatty acids.
The omega-3 fatty acid is chosen from the group consisting of alpha-linolenic acid (C18:3, n-3), eicosatetraenoic acid (C20:4, n-3), moroctic acid (C18:4, n-3), eicosapentaenoic acid (EPA) (C20:5, n-3), heneicosapentaenoic acid (C21:5, n-3), docosapentaenoic acid (C22:5, n-3), and docosahexaenoic acid (DHA) (C22:6, n-3), and combinations thereof. The omega-6 fatty acid is chosen from the group consisting of linoleic acid 18:2 (n-6), eicosatrienoic acid 20:3 (n-6), arachidonic acid 20:4 (n-6), and combinations thereof.
In accordance with one aspect, the fatty acid anion comprises a complex mixture of multiple omega fatty acid anions and other fatty acid anions. This complex mixture of fatty acids can be derived from:
(a) fish oils, seed oils, or microbial oils, or
(b) esters of fish oils, seed oils, or microbial oils, or
(c) triglycerides resulting from the re-esterification of purified esters from fish oils, seed oils, microbial oils.
In accordance with one aspect of the co-salt, the fish oil is 18% by weight EPA and 12% by weight DHA.
In accordance with one aspect of the co-salt, the ratio of the fatty acid anion to the non-fatty acid co-anion ranges from about 50:50 to 70:30, the cation for the salts is calcium or magnesium, the non-fatty acid salt is citrate or phosphate; and the omega-3 fatty acid content comprises about 15-47% of the weight of the co-salt.
The co-salt is produced by forming a salt solution comprised of a soluble fatty acid salt and a soluble non-fatty acid salt; adding a water solution of MX or MX 2 to the salt solution to form a reaction solution, where M is a divalent or monovalent cation, or mixtures of divalent and/or monovalent cations, and X is a water soluble anion; and then filtering the co-salt precipitate from the solution. After the precipitate has been filtered, it can be dried. It will be appreciated that the soluble fatty acid salt may, in fact, be a mixture of fatty acid salts.
The MX or MX 2 is added to the salt solution in an equimolar amount of the cation to the combined molar amount of the anions of salt solution.
In accordance with one aspect of the method, the salt solution is formed by combining a solution of a soluble fatty acid salt and a solution of a soluble non-fatty acid salt. In a preferred method, the soluble non-fatty acid salt solution is added to the soluble fatty acid salt in solution. In accordance with another aspect of the method, the salt solution is formed by producing an anion solution comprised of a fatty acid anion and a non-fatty acid anion; and adding a cation to the anion solution which will combine with the fatty acid and non-fatty acid to form soluble fatty acid salts and soluble non-fatty acid salts. The salt solution comprises sodium, potassium or ammonium fatty acid and non-fatty acid salts. Hence, in the second method of forming the salt solution, the cation is sodium, potassium or ammonium.
In the cation solution which is added to the salt solution, M is chosen from the group consisting of Ca, Mg, Cu, Zn, Fe, Mn, K, Na, NH 4 and combinations thereof; and X is chosen from the group consisting of Cl − , NO 3 − , SO 4 −2 , acetate, formate, carbonate, bicarbonate, and the like and combinations thereof.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 shows X-ray Diffraction Patterns of (1) a 50:50 Calcium Citrate Calcium/Fatty Acid Co-Salt (bottom line) prepared in accordance with the claimed invention; (2) Calcium Citrate (top line) and (3) a 50:50 admixture of Calcium Fatty Acid Salt and Calcium Citrate salt (middle line);
FIG. 2 is an infrared spectra of calcium citrate tetrahydrate, a calcium salt derived from an omega-3 fish oil, and a co-precipitated calcium co-salt containing citrate anion and an omega-3 anion; and
FIG. 3 is an infrared spectra of calcium phosphate tribasic, a calcium salt derived from omega-3 fish oil, and a co-precipitated calcium co-salt containing phosphate and the omega-3 anion.
Corresponding reference numerals will be used throughout the several figures of the drawings.
DETAILED DESCRIPTION
The following detailed description illustrates the invention by way of example and not by way of claimed limitation. This description will clearly enable one skilled in the art to make and use the claimed invention, and describes several embodiments, adaptations, variations, alternatives and uses of the claimed invention, including what we presently believe is the best mode of carrying out the claimed invention. Additionally, it is to be understood that the claimed invention is not limited in its application to the details of construction and the arrangements of components set forth in the following description or illustrated in the drawings. The claimed invention is capable of other embodiments and of being practiced or being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.
It has been found that co-precipitated anion co-salts can be produced that yield easy to handle free flowing compounds. These co-precipitated salts can be comprised of a cation such as Ca or Mg and a mixture of at least one fatty acid anion and at least one non-fatty acid co-anion. Other cations, such as Fe, Mn, K, Cu, Zn, and Na or other divalent or monovalent metal ions may also be acceptable. The fatty acid anion for the co-salt can be a mixture of omega fatty acids obtained from commercial fish oils or seed oils or their esters or re-esterified products by saponification as well as DHA/EPA enhanced fatty acids or esters that are commercially available. These fatty acids can be obtained from microbial products (algae) as well. The mixture of omega fatty acids can include alpha-linolenic acid, moroctic acid, eicosatetraenoic acid, eicosapentaenoic acid (EPA), heneicosapentaenoic acid, docosapentaenoic acid, docosahexaenoic acid (DHA), arachidonic acid (ARA), and alpha linoleic acid. The co-anion of the co-salt can be selected from any of a large number of commercial acids such as citric, lactic, phosphoric, fumaric, malic, gluconic, carbonic, sulfuric, and the like. Acetic acid, ascorbic acid and aspartic acid or any other organic or inorganic acid that will form salts with the above-noted cations can be used for the second anion. Additionally, formic acid, propionic acid, succinic acid, adipic acid, salicyclic acid, benzoic acid, phthalic acid, maleic acid, malonic acid, pyruvic acid, sorbic acid, caprylic acid, glutaric acid, pimelic acid, glucoheptanoic acid, glycerophosphoric acid, glutamic acid, glutathione, lecithin, phenylalanine, valine, leucine, isoleucine, threonine, methionine, lysine, arginine, histidine could be used as well. It will be understood that the polyprotic acids may be present in their respective states of protonation. The final product (i.e., the co-salt) is granular and free flowing, and can be utilized in products that are meant to be fortified with mineral salts and omega fatty acids. The product can be crystalline (or can exhibit some degree of crystallinity).
In practice, a complex and variable mixture of omega fatty acids is expected to be used in producing the mixture. Thus, for example, a final product of a 50:50 co-precipitated calcium co-salt with citric acid and omega-3 acid anions will contain various mixtures of the individual fatty acids obtained from the original oil. For example, menhaden oil, a common fish oil, can provide the acids found in Table 1, below.
TABLE 1
MENHADEN OIL - TYPICAL FREE FATTY ACID PROFILE
Fatty Acid
Weight % in
(Chain Length:Number of Double Bonds)
Menhaden Oil
Myristic Acid 14:0
10.86
15:0
0.67
Palmitic Acid 16:0
18.20
Palmitoleic 16:1 (n-7)
13.79
16:2 (n-4)
2.35
16:4 (n-1)
2.34
17:0
0.64
Stearic Acid 18:0
2.89
Oleic Acid 18:1 (n-9)
9.60
18:1 n-7
3.57
18:2 n-6
1.60
Linoleic Acid 18:2 (n-6)
1.60
alpha-Linolenic Acid 18:3 (n-3)
1.23
Stearidonic Acid 18:4 (n-3)
3.63
20:1 (n-9)
1.53
Eicosatrienoic Acid 20:3 (n-6)
0.19
Arachidonic Acid 20:4 (n-6)
0.89
20:4 (n-3)
1.43
Eicosapentaenoic Acid 20:5 (n-3) (EPA)
13.87
Docosapentaenoic Acid 22:5 (n-3)
1.86
Docosahexaenoic Acid 22:6 (n-3) (DHA)
7.10
Reference: Yang, L. Y.; Kuksis, A.; Myher, J. J., Journal of Lipid Research, Vol. 31, 1990, p. 37
Each of these fatty acids will be contained in the final product as the salt of the particular fatty acid in the same mole ratio found in the original oil. The mixture of fatty acids has a fixed average molecular weight that is determined by titration. The total variety of acid anions obtained from each oil will be called, for ease, “omega-ate” when these anions are incorporated in a salt. For example, in a 50:50 co-salt of calcium citrate with the fatty acids of the above fish oil, the initial amount of DHA would be 50% of 7.1% or 3.55% based on the chart above factored down to account for the calcium and water in the final product. The co-anion would be citrate and the mixture of the above fatty acids from the fish oil would be “omega-ate”.
In naming these co-precipitated co-salts, the nominal ratio, (say for a 70:30 co-salt) describes the relative weights of the two salts present in the product. The first value describes the weight percent of the fatty acid salt. The second value describes the weight percent of the non-fatty acid salt. For example, a “70:30 calcium citrate co-salt” would describe a co-salt comprised of 70% by weight calcium omega-ate salt and 30% by weight calcium citrate.
The Tables 3-5 below show results of calculations of theoretical total percent of calcium (or magnesium) of the co-precipitated salt using fish oil having different amounts of omega fatty acids and for varying ratios of the free fatty acid to the secondary non-free fatty acid anion. The calculations are based on a single admixture of a calcium fatty acid salt and calcium citrate-tetrahydrate. Tables 3-5 are intended to depict the range of possible product concentrations of both the mineral nutrient, either calcium or magnesium, and the omega-3 content from varying the omega-3 content of the starting fish oil or from varying the ratio of the two anions. Table 2 below is a two-axis table showing, along the vertical axis, the various co-anions that can be used, and along the horizontal axis, the various cations that can be used in the production of the co-salt. It will be understood that any co-salt produced will also include a fatty acid component as well.
TABLE 2
Co-anion - Cation table
Ca
Mg
Cu
Zn
Fe
Mn
K
Na
NH 4
citric acid
lactic acid
phosphoric acid
fumaric acid
malic acid
gluconic acid
acetic acid
ascorbic acid
aspartic acid
carbonic acid
sulfuric acid
formic acid
propionic acid
succinic acid
adipic acid
salicyclic acid
benzoic acid
phthalic acid
maleic acid
malonic acid
pyruvic acid
sorbic acid
caprylic acid
glutaric acid
pimelic acid
glucoheptanoic acid
glycerophosphoric acid
glutamic acid
glutathione
lecithin
phenylalanine
valine
leucine
isoleucine
threonine
methionine
lysine
arginine
histidine
In preparing the co-salt, any of the cations can be paired with any of the co-anions. Thus, the co-salt can be made using calcium as the cation and citric acid as the co-anion. Alternatively, sodium can be used as the cation with ascorbic acid as the co-anion. Further, although the examples below disclose compounds which use only a single co-anion and only a single cation, the co-salt can be formed using two or more cations and/or using two or more co-anions. Hence, for example a co-salt could be prepared using, as anions, an omega-ate, citric acid and malic acid. Similarly, a co-salt could be prepared using calcium and magnesium as cations. If a single cation (e.g., calcium) is used with the two co-anions (e.g., citric acid and malic acid), a calcium-omega-ate/malate/citrate co-salt would be produced. If only one secondary anion (e.g., citric acid) and two cations (e.g., calcium and magnesium) were used, a calcium/magnesium-omega-ate/citrate co-salt would be produced. Finally, if two secondary anions (e.g., citric acid and malic acid) and two cations (e.g., calcium and magnesium) were used, the resulting co-salt would be a calcium/magnesium-omega-ate/citrate/malate co-salt would be produced. The co-salt could also be prepared using more than two cations and/or more than two secondary anions.
The concentration of the omega-3 of the co-salt is fixed by the origin of the free fatty acid (FFA). For the “70:30 calcium citrate co-salt” example of Table 3, below, if the original free fatty acid contained 30% EPA+DHA, then the final product would contain 21% by weight calcium salts of EPA+DHA, and would contain 10.9% by weight calcium. As can be appreciated, the percent by weight calcium in the co-salt includes the calcium in both the fatty acid salt and the non-fatty acid salt.
The ratio of the FFA anions to the non-fatty acid anion can range from about 90% FFA by weight (i.e., about a 90:10 ratio) to about 90% non-fatty acid by weight (i.e., about a 10:90 ratio). Thus, for example, in a citrate co-salt, a co-salt can be produced that contains about 90% fatty acid and about 10% of the citrate (about 90:10) while a product at the opposite end of the range can contain about 10% fatty acid and about 90% citrate (about 10:90). Table 3 summarizes an example of the range of products made from a 35% omega-3 fish oil and citrate anions with calcium as the metal ion.
TABLE 3
% Omega-3 Salt and % Calcium Contents
for Various Co-Salt Compositions
Wt % Ca-ω-3
Total wt %
wt %
Total
Wt %
as
as
Ca-ω-3*
Calcium
wt %
Ca-FFA
EPA
DHA
(EPA + DHA)
Citrate
Calcium
10
1.8
1.2
3.0
90
19.6
30
5.4
3.6
9.0
70
16.7
45
8.1
5.4
13.5
55
14.5
50
9.0
6.0
15.0
50
13.8
60
10.8
7.2
18.0
40
12.3
65
11.7
7.8
19.5
35
11.6
70
12.6
8.4
21.0
30
10.9
90
16.2
10.8
27.0
10
8.0
*This column contains the % by weight calcium EPA + DHA. Actual EPA + DHA content, as the free acid, is calculated based on the starting average free fatty acid molecular weight. For example, a 1,000-mg tablet of a “70:30 calcium citrate co-salt” would contain 196-mg EPA + DHA, and 109-mg calcium.
Table 4 shows the same 35% omega-3 fish oil product using magnesium phosphate as the co-salt.
TABLE 4
% Omega-3 Salt and % Magnesium Contents
for Various Co-Salt Compositions
wt % Mg-Ω-3
wt %
as
as
Total % Mg-Ω3
wt % Mg
total
Mg-FFA
EPA
DHA
(EPA + DHA)
Phosphate
wt % Mg
30
5.4
3.6
9.0
70
15.7
45
8.1
5.4
13.5
55
13.2
50
9.0
6.0
15.0
50
12.4
60
10.8
7.2
18.0
40
10.7
65
11.7
7.8
19.5
35
9.9
90
16.2
10.8
27.0
10
5.8
If the omega-3 percentage in the starting oil is increased to 65%, the results in Table 5 are produced for an array of calcium phosphate co-salts:
TABLE 5
% Omega-3 Salt and % Calcium Contents
for Various Co-Salt Compositions
wt % Ca-Ω-3
wt %
as
as
Total % Ca-Ω3
wt % Ca
total
Ca-FFA
EPA
DHA
(EPA + DHA)
Phosphate
wt % Ca
30
11.7
7.8
19.5
70
29.8
45
17.6
11.7
29.3
55
24.8
50
19.5
13.0
32.5
50
23.1
60
23.4
15.6
39.0
40
19.7
65
25.4
16.9
42.3
35
18.1
90
35.1
23.4
58.5
10
9.7
It is clear that there is a wide variety of products that will contain different amounts of the cation and the omega-ate anions.
Evidence of New Compound:
FIG. 1 shows X-ray Diffraction Patterns of (1) a 50:50 Calcium Citrate Calcium/Fatty Acid Co-Salt (bottom line) prepared in accordance with the method described below; (2) Calcium Citrate (top line) and (3) a 50:50 admixture of Calcium Fatty Acid Salt and Calcium Citrate salt (middle line). An admixture is defined simply as a mixture in which the mixture components (calcium fatty acid salt and calcium citrate salt in this example) are dry-blended together. As seen from FIG. 1 , the X-ray diffraction patterns indicate that there is some crystallinity in the co-salt. The X-ray diffraction of FIG. 1 makes clear that the 50:50 precipitated co-salt product is different from a 50:50 dry blend or admix of the calcium citrate and calcium fatty acid salt.
FIG. 3 shows the infrared spectra of calcium phosphate (top line), a calcium salt derived from fish oil (middle line), and a co-precipitated calcium salt containing phosphate ion and an omega-ate anion (bottom line). The strong band at 1026 cm−1 in the spectrum of calcium phosphate is characteristic of a P-O stretching mode for an ionic phosphate group (tetrahedral symmetry). The shift to lower wave numbers (5 cm−1) observed for the P-O stretching mode of the phosphate ion in the spectrum of the co-precipitated salt demonstrates that a novel calcium omega-ate phosphate co-salt has formed. The bands of interest in the spectrum of the Ca omega-ate co-salt are the asymmetric and symmetric COO— stretching modes centered at 1540 cm−1 and 1434 cm 1, respectively, in the middle line. The shift to higher wave numbers in the spectrum of the co-precipitated co-salt also indicate a novel calcium omega-ate phosphate co-salt has been formed as opposed to a simple mixture of the two salts.
FIG. 2 shows the infrared spectra of calcium citrate (top line), a calcium salt derived from omega-ate fish oil fatty acids (middle line), and a co-precipitated calcium co-salt containing citrate and omega-ate anions (bottom line), hereafter called calcium citrate 50:50 co-salt. The bands of interest are the asymmetric and symmetric COO— stretching vibrations centered at approximately 1550 cm−1 and 1430 cm−1, respectively, in the middle line, and the wagging and scissoring modes in the region of 600 to 1310 cm−1, which are more well defined in the spectra of calcium citrate (top line) and the co-precipitated co-salt (bottom line). The change in splitting patterns and shifts in wave number of the COO— stretching vibrations observed in the spectrum of the co-precipitated salt relative to the same modes in the spectra of calcium citrate or calcium omega-ate demonstrate the formation of a novel compound, as opposed to a simple mixture of the two salts. For example, the symmetric COO— stretching vibrations mode is characterized by a strong doublet observed at 1433 cm−1 and 1386 cm−1 in the spectrum of calcium citrate, whereas the symmetric COO— stretching vibrations mode is characterized by a unique singlet at 1429 cm−1 in the spectrum of the co-precipitated co-salt. Furthermore, the wagging and scissoring modes observed in the region of 600 cm−1 to 1310 cm−1 remain well defined in the spectrum of the co-precipitated co-salt but are shifted to higher wave numbers, further demonstrate the formation of a novel species.
General Preparation and Working Examples:
The co-precipitated co-salt is produced by preparing a solution of a soluble fatty acid (omega-ate) salt and a co-anion salt. The salt solution is prepared at ambient or room temperature (i.e., approximately 25-32° C.) The salt of the anions can be a sodium salt. Potassium or ammonium are expected to work as well. The soluble salt solution can be prepared two ways. In a first method, a co-anion salt solution is added to a fatty acid salt solution. In a second method, the anions (i.e., the omega-ate ions and the co-anion) are combined and, for example, a sodium solution (i.e., an NaOH solution) is added to the anion solution to form the fatty acid and co-anion salts. In the first noted method, the sodium salt solution of the free fatty acid can be derived from saponifying fish oils, the ethyl or methyl esters of fish oil fatty acids or from transesterification of those oils. The same technique can be applied to seed oils, microbial oils and re-esterified omega-3 acid products. Possible choices for co-anions include citric acid, lactic acid, phosphoric acid, fumaric acid, malic acid, gluconic acid, acetic acid, ascorbic acid, aspartic acid, carbonic acid, or sulfuric acid, formic acid, propionic acid, succinic acid, adipic acid, salicyclic acid, benzoic acid, phthalic acid, maleic acid, malonic acid, pyruvic acid, sorbic acid, caprylic acid, glutaric acid, pimelic acid, glucoheptanoic acid, glycerophosphoric acid, glutamic acid, glutathione, lecithin, phenylalanine, valine, leucine, isoleucine, threonine, methionine, lysine, arginine, histidine and the like and combinations thereof. As noted above, the polyprotic acids may be present in their respective states of protonation. This soluble salt solution is viscous.
After the soluble salt solution has been prepared, an exchange reaction is performed in which, with vigorous stirring, a water solution of MX or MX 2 is added (where M can be Ca, Mg, Cu, Zn, Fe, Mn, or other divalent cations and X is a water soluble anion such as Cl − , NO 3 − , SO 4 −2 , acetate, formate, and the like). The co-salt immediately begins precipitating with the addition of the metal salt solution (different metal salts have slightly different solubilities). After addition of at least a stoichiometrically equivalent amount of cation to the combined molar amount of the two anions, the solution is digested for an hour. It is then filtered, washed with water, and dried. The final product is a solid free flowing material.
Without the second anion, it has been demonstrated that many of the metal salts of the pure oils are waxy and do not filter or dry well. They also do not blend well with other products. The reaction of the second anion contributes to improved handling properties of these products.
EXAMPLES
Table 6 below presents experimental data showing various co-salts that have been produced employing the general co-precipitation procedure described above. Specific and detailed “working examples”, described later, elaborate on the concept. In addition, Table 6 provides the theoretical weight percents of the omega-3 fatty acid (i.e., combined EPA and DHA) and the theoretical weight percent of the cation (i.e., calcium or magnesium). As described above, the theoretical weight percents are calculated assuming an admixture of the omega-ate salt with calcium citrate tetrahydrate, calcium phosphate, and magnesium phosphate.
TABLE 6
Summary of Analysis of Composition of Co-Salts Prepared by Coprecipitation
Total %
% Moisture Wt
Theoretical Wt %
Theoretical
Co-Salt Description
% DHA
% EPA
[EPA + DHA]
wt % cation
Loss by TGA
EPA + DHA
wt % Cation
Calcium Citrate Co-Salts
% Ca-
% Ca-FFA
Citrate
10
90
1.31
1.66
3.0
20.4
3.0
19.6
10
90
0
0.1
0.1
18.0
3.0
19.6
52
48
7.69
8.80
16.5
12.0
7.4
18.7
13.5
50
50
4.98
6.54
11.5
12.6
3.0
13.8
50
50
4.24
6.04
10.3
50
50
2.06
3.39
5.5
12.0
3.7
15.0
13.8
70
30
9.66
12.05
21.7
10.6
2.3
21.0
10.9
70
30
3.38
4.95
8.3
10.1
4.0
21.0
10.9
90
10
10.96
13.93
24.9
7.0
2.0
27.0
8.0
Calcium Phosphate Co-Salts
% Calcium
% Ca-FFA
Phosphate
50
50
6.67
8.26
14.9
20.8
2.0
15.0
23.2
70
30
9.06
11.21
20.3
14.7
6.0
21.0
16.5
30
70
3.82
4.78
8.6
26.6
2.5
9.0
29.9
50 (high
50
10.40
35.96
46.3
20.8
2.2
47.0
23.0
ω-3-FFA)
Magnesium Phosphate Co-Salts
% Mg-
% Mg-FFA
Phosphate
50
50
6.87
8.38
15.3
9.7
5.7
15.0
12.3
50
50
6.31
7.94
14.3
10.7
15.0
12.3
6.19
7.70
13.9
11.0
15.0
12.3
(All %- values are weight %)
The fact that the experimental data differed from the theoretical calculations, as shown in Table 6 above, is further evidence that the co-salt is a novel compound and not simply an admixture of two salts.
Working Example A
Preparation of 50:50 Calcium Omega-3 Salt: Calcium Citrate Tetrahydrate Co-Salt
1. Preparation of Free Fatty Acid Sodium Salt Solution: Assemble a round bottom 2-Liter three-necked flask equipped with a motor-driven Teflon paddle stirrer, a nitrogen purge inlet, a heating mantle, and a 130-mL capacity addition funnel with pressure-equalizing sidearm. Purge thoroughly with nitrogen. Then add 320-mL's degassed deionized water. Continue a slow nitrogen purge throughout the remaining steps. 2. Next, add 46.9 grams of a “free fatty acid” mixture derived from menhaden oil by saponification and having an average equivalent weight of 288 grams/mole. 3. Adjust the temperature of the stirring mixture to 30-32° C. Then add dropwise a solution of 13.0 grams 50% sodium hydroxide dissolved in 100-mL's of degassed deionized water. 4. Preparation of Trisodium Citrate Solution: In a separate 400 mL glass beaker equipped with a magnetic stirbar, and using a stirrer/hot-plate, make a solution by mixing 150-mL's deionized water, 33.7 grams citric acid, and 42.0 grams 50% sodium hydroxide. Use a cooling water bath to cool the solution to 30-32° C. 5. Over a 10-minute period and with rapid stirring, add all of the “Trisodium Citrate solution” to the “Free Fatty Acid Sodium Salt solution”. As the addition proceeds, add 200 mL's more degassed deionized water to the stirring mixture. 6. When the addition of the “Trisodium Citrate solution” to the “Free Fatty Acid Sodium Salt solution” is complete, continue rapid stirring of the somewhat viscous solution. 7. Next, begin the dropwise addition of 163 mL's of a 21.5% aqueous solution of calcium chloride. The addition rate is such that about one hour is required for complete addition of the 163-mL's of calcium chloride solution. Precipitation occurs throughout the addition. The final resulting reaction mixture is a thick slurry of white solids. 8. Stir for an additional one hour. 9. Collect the product by vacuum filtering the slurry on a 12.5-cm Buchner Funnel, using a Fisherbrand number 6, glass fiber filter medium. Wash the product with 200-mL's degassed deionized water. 10. Dry the wet product in a vacuum oven to constant weight. The theoretical weight of dry product is 100-grams. Actual obtained dry weight is 98.5-grams.
Product Analysis:
50:50 Calcium Omega-3 Salt: Calcium Citrate Co-Salt
% Calcium=12.6%
% EPA+DHA, by GC Analysis, as fatty acid methyl esters (FAMES)=11.5%
Theoretical Expected % [EPA+DHA]=15.0%
Thermogravimetric Analysis of % Weight Loss on Heating to 120° C.=3.0%
The product is a solid free flowing material.
Working Example B
Preparation of 50:50 Calcium High-Omega-3 Salt: Calcium Phosphate Co-Salt
1. Preparation of Free Fatty Acid Sodium Salt Solution: Assemble a round bottom 2-Liter three-necked flask equipped with a motor-driven Teflon paddle stirrer, a nitrogen purge inlet, a heating mantle, and a 130 mL capacity addition funnel with pressure-equalizing sidearm. Purge thoroughly with nitrogen. Then add 320 mL's degassed deionized water. Continue a slow nitrogen purge throughout the remaining steps. 2. Next, add 47.1 grams of a “free fatty acid” mixture derived by saponification from a highly refined re-esterified fish oil. The free fatty acid has an average equivalent weight of 313 grams/mole. The gas chromatographic assay of the starting re-esterified oil, by fatty acid methyl ester (FAME) analysis was 94% (EPA+DHA). 3. Adjust the temperature of the stirring mixture to 29-31° C. Then add dropwise a solution of 11.5 grams 50% sodium hydroxide dissolved in 100-mL's of degassed deionized water. Adjust the temperature of the solution to 30° C. 4. Preparation of Trisodium Phosphate Solution: In a separate 600-mL glass beaker equipped with a magnetic stirbar, and using a stirrer/hot-plate, make a solution by adding 420-mL's deionized water, followed by 34.6 grams 85% Phosphoric Acid. To the diluted Phosphoric Acid solution, add dropwise 72.5 grams 50% Sodium Hydroxide (0.906 mole). Use a cooling water bath to cool the solution to 30-32° C. 5. Over a 10-minute period and with rapid stirring, add all of the “ Trisodium Phosphate solution ” to the “ Free Fatty Acid Sodium Salt solution ”. As the addition proceeds, add 300-mL's more degassed deionized water to the stirring mixture. 6. When the addition of the “ Trisodium Phosphate solution ” to the “ Free Fatty Acid Sodium Salt solution ” is complete, continue rapid stirring of the somewhat viscous solution. Adjust the temperature to 26° C. 7. Next, begin the dropwise addition of 260-mL's of a 21.5% aqueous solution of calcium chloride. The addition rate is such that about one hour is required for complete addition of the 260-mL's of calcium chloride solution. Precipitation of very small, white solids occurs throughout the addition. The final resulting reaction mixture is a thick slurry of white solids. 8. Stir for an additional one hour. 9. Collect the product by vacuum filtering the slurry on a 12.5-cm Buchner Funnel, using a Fisherbrand number 6, glass fiber filter medium. Wash the product with 300-mL's degassed deionized water. 10. Dry the wet product in a vacuum oven to constant weight. The theoretical weight of dry product is 100-grams. Actual obtained dry weight is 102-grams.
Product Analysis:
50:50 Calcium High-Omega-3 Salt: Calcium Phosphate Co-Salt:
% Calcium=20.8%
% EPA+DHA, by GC Analysis, as fatty acid methyl esters (FAMES)=46.3%
Theoretical Expected % [EPA+DHA]=47.0%
Thermogravimetric Analysis of % Weight Loss on Heating to 120° C.=2.2%
The product is a solid free flowing material.
Working Example C
Preparation of 50:50 Magnesium Omega-3 Salt: Magnesium Phosphate Co-Salt
1. Preparation of Free Fatty Acid Sodium Salt Solution: Assemble a round bottom 2-Liter three-necked flask equipped with a motor-driven Teflon paddle stirrer, a nitrogen purge inlet, a heating mantle, and a 130-mL capacity addition funnel with pressure-equalizing sidearm. Purge thoroughly with nitrogen. Then add 320-mL's degassed deionized water. Continue a slow nitrogen purge throughout the remaining steps. 2. Next, add 46.9 grams of a “free fatty acid” mixture derived from menhaden oil by saponification and having an average equivalent weight of 288 grams/mole. 3. Adjust the temperature of the stirring mixture to 30-32° C. Then add dropwise a solution of 13.0 grams 50% sodium hydroxide dissolved in 100-mL's of degassed deionized water. 4. Preparation of Trisodium Phosphate Solution: In a separate 600-mL glass beaker equipped with a magnetic stirbar, and using a stirrer/hot-plate, make a solution by adding 420-mL's deionized water, followed by 32.6 grams 85% Phosphoric Acid. To the diluted Phosphoric Acid Solution, add dropwise 67.9 grams 50% Sodium Hydroxide. Use a cooling water bath to cool the solution to 30-32° C. 5. Over a 10-minute period and with rapid stirring, add all of the “Trisodium Phosphate solution” to the “Free Fatty Acid Sodium Salt solution”. As the addition proceeds, add 200-mL's more degassed deionized water to the stirring mixture. 6. When the addition of the “Trisodium Phosphate solution” to the “Free Fatty Acid Sodium Salt solution” is complete, continue rapid stirring of the somewhat viscous solution. Adjust the temperature to 26° C. 7. Prepare an aqueous solution of magnesium chloride at a concentration of 16% by weight, on an anhydrous MgCl 2 basis. 8. Next, begin the dropwise addition of 318-g of the 16% magnesium chloride solution to the stirring mixture of trisodium phosphate and free fatty acid sodium salts. The addition rate for the magnesium chloride solution is such that about one hour is required for complete addition of the 318-g of solution. Precipitation of very small, white solids occurs throughout the addition. 9. Once the addition of the magnesium chloride solution is complete, stir the slurry for 1.5 hours at 25-27° C. The final resulting reaction mixture is a thick slurry of white solids. 10. Collect the product in two separate loads on a lab-scale “IEC Clinical Centrifuge” having a stainless steel basket with a diameter of 5-inches, and using a polypropylene cloth as the filter medium. Each load is washed with 150-mL's deionized water. 11. Dry the wet product in a vacuum oven to constant weight. The theoretical weight of dry product is 100-grams. Actual obtained dry weight is 75-grams, since a portion of the product slurry was used for testing the centrifuge cloth prior to filtration.
Product Analysis:
50:50 Magnesium Omega-3 Salt: Magnesium Phosphate Co-Salt
% Magnesium=9.7%
% EPA+DHA, by GC Analysis, as fatty acid methyl esters (FAMES)=15.3%
Theoretical Expected % EPA+DHA=15.0%
Thermogravimetric Analysis of % Weight Loss on Heating to 120° C.=5.7%
The product is a solid free flowing material.
Working Example D
Preparation of 90:10 Calcium Omega-3 Salt: Calcium Citrate Tetrahydrate Co-Salt
1. Preparation of Mixed Sodium Salt Solution: Assemble a round bottom 2-Liter three-necked flask equipped with a motor-driven Teflon paddle stirrer, a nitrogen purge inlet, a heating mantle, and a 130-mL capacity addition funnel with pressure-equalizing sidearm. Purge thoroughly with nitrogen. Then add 600-mL's degassed deionized water. Continue a slow nitrogen purge throughout the remaining steps. 2. Next add 6.74-grams citric acid. 3. Next, add 84.1 grams of a “free fatty acid” mixture derived from menhaden oil by saponification and having an average equivalent weight of 288 grams/mole. 4. Adjust the temperature of the stirring mixture to 30-32° C. Then add dropwise a solution of 32.0 grams 50% sodium hydroxide dissolved in 100-mL's of degassed deionized water. 5. Cool the solution to <30° C. 6. Exchange Reaction: Next, begin the dropwise addition of 100-mL's of a 21% aqueous solution of calcium chloride. The addition rate is such that about 45-minutes is required for complete addition of the 100-mL's of calcium chloride solution. Precipitation occurs throughout the addition. The final resulting reaction mixture is a thick slurry of white solids. 7. Stir for an additional one hour. Then, shut off the agitator and allow to sit overnight under nitrogen blanket. 8. Collect the product by vacuum filtering the slurry on a 12.5-cm Buchner Funnel, using a Fisherbrand number 6, glass fiber filter medium. Wash the product with 200-mL's degassed deionized water. 9. The wet product was next reslurried in 400-mL's degassed deionized water. Then, it was again collected on a Buchner Funnel employing a Fisherbrand No. 6 glass fiber filter. 10. Dry the wet product in a vacuum oven to constant weight. The theoretical weight of dry product is 100-grams. Actual obtained dry weight is 104-grams.
Product Analysis:
90:10 Calcium Omega-3 Salt: Calcium Citrate Co-Salt
% Calcium=7.0%
% EPA+DHA, by GC Analysis, as fatty acid methyl esters (FAMES)=24.9%
Theoretical Expected % [EPA+DHA]=27.0%
Thermogravimetric Analysis of % Weight Loss on Heating to 120° C.=2.0%
The product is a solid free flowing material.
The working examples A-D use a fish oil that is either 30% or 94% by weight omega-3 fatty acids; they use citrate or phosphate as the co-anion, and calcium or magnesium as the mineral. There were two experiments in which co-salts did not form. In the first, a 50:50 magnesium citrate co-salt was attempted. The procedure gave two distinct salts. It is believed that one factor that may have resulted in the inability to produce a co-salt was the fact that at the temperatures under which the experiment was conducted (i.e., about 30° C.), magnesium citrate stays in solution and the omega-3 citrate precipitates out. It is believed that if the experiment were conducted at a somewhat hither temperature or that if a lower ratio of omega-3 fatty acid were used, that a co-salt would have formed. In the second, a 50:50 calcium citrate co-salt was attempted to be made using a fish oil that was 94% omega-3 fatty acid by weight (that is, the oil had a very high concentration of omega-3 fatty acids). Calcium citrate co-salts did not form when the fatty acid starting material had an omega-3 concentration above about 50%. However, if the starting material is less than 50% omega-3 fatty acid, the calcium citrate co-salt was formed. In fact, as seen in Table 6, calcium citrate co-salts were formed.
Working Example B used a fatty acid starting material that was about 94% fatty acid by weight. Hence, co-salts can be formed using highly concentrated (or very pure) omega-3 fatty acid compositions.
As various changes could be made in the above constructions without departing from the scope of the claimed invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. For example, although the working examples use a fish oil that 35% or 65% omega-3 fatty acids by weight, the starting oil could have an omega-3 content as low as 5% by weight and as high as 100% by weight (i.e., pure omega-3 fatty acid). This example is merely illustrative.
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A co-salt of a polyunsaturated fatty acid and a non-fatty acid is formed as a precipitate. The co-salt formed is free flowing and does not tend to agglomerate (cake) in storage. The resultant co-salt product will be easy to blend with other products to produce dietary supplements. These novel co-salt products may also tablet very well and may be added to current dietary supplement tablets.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a Continuation Application of prior of application Ser. No. 12/343,860, filed on Dec. 24, 2008 in the United States Patent and Trademark Office, which claims the benefit of Korean Patent Application No. 2008-0027810, filed on Mar. 26, 2008 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an image reading apparatus, and a multi-functional machine having the same, and, more particularly, to an image reading apparatus with improved reliability of a document discharging operation, and a multi-functional machine having the same.
2. Description of the Related Art
An image reading apparatus reads an image recorded on a document through an image sensor. Devices containing image reading apparatuses include copiers, scanners, fax machines, multi-functional devices, and similar image reading machines. In order to read information from the document, the image reading machine must either move a reading unit relative to a stationary document or the document relative to a stationary reading unit. An image reading machine in which the document moves is known as a “sheet feed type”.
The sheet feed type image reading machine includes an automatic document feeder which feeds the document through the machine. The document fed by the automatic document feeder is scanned by the reading unit and, once scanned, discharged to the outside. If the document is not fully discharged from the unit, the stalled document may cause the subsequently scanned and discharged document(s) to jam or shuffle out of sequence.
Many image reading machines discharge a document using a dedicated discharge roller disposed at the downstream side of the reading unit after reading an image. While the dedicated rollers may ensure the discharging of the documents, the space required for the installation of the dedicated rollers places a limit on reduction of the size of the image reading machine.
Some image reading machines discharge documents without using a discharge roller. If a document outlet of the image reading machine is positioned a sufficient distance below the reading unit, the document's own weight propels it downward to the document outlet. This configuration however unfortunately also places a limit on the minimum size of the image reading machine, particularly in the vertical dimension.
BRIEF DESCRIPTION OF THE DRAWINGS
Various aspects and advantages of the embodiments of the invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings, of which:
FIG. 1 illustrates a configuration of a multi-functional machine including an image reading machine according to an embodiment of the invention;
FIG. 2 illustrates a perspective view of the image reading machine of FIG. 1 according to an embodiment of the invention;
FIG. 3 illustrates an enlarged view of a portion of FIG. 1 ;
FIG. 4 is a diagram illustrating a document discharging operation according to an embodiment of the invention;
FIG. 5 illustrates a perspective view of a partial configuration of an image reading machine according to another embodiment of the invention; and
FIG. 6 illustrates a perspective view of a partial configuration of an image reading machine according to another embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will now be made in detail to exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. While the embodiments are described with detailed construction and elements to assist in a comprehensive understanding of the various applications and advantages of the embodiments, it should be apparent however that the embodiments can be carried out without those specifically detailed particulars. Also, well-known functions or constructions will not be described in detail so as to avoid obscuring the description with unnecessary detail. It should be also noted that in the drawings, the dimensions of the features are not intended to be to true scale, and may be exaggerated for the sake of allowing greater understanding.
As shown in FIGS. 1 and 2 , an example multi-functional machine 1 may include a main body 10 , an image reading apparatus 100 which reads image information from the document, and a printing apparatus 200 which prints an image on a printing medium. FIG. 2 omits an upper cover 20 and a white roller 126 which are present in FIG. 1 . Although an image reading machine is described in this embodiment as a part of a multi-functional machine including a facsimile function, the following description may be applied to other embodiments of a multi-functional machine having no facsimile function, a copying machine, a scanner and various other machines which read an image recorded on the document through a reading unit.
The main body 10 defines an external appearance of the multi-functional machine 1 . Various parts forming the image reading apparatus 100 and the printing apparatus 200 may be supported in and/or on the main body 10 .
The multi-functional machine 1 may include a printing apparatus 200 , which prints an image on a printing medium according to the image read by the image reading apparatus 100 or according to a fax image received from an external communication network. The printing apparatus 200 may include a paper loading tray 210 , a paper pickup roller 220 , a paper feed roller 230 , a printing unit 240 and a paper discharge roller 250 . In a printing operation, a printing medium such as paper S may be loaded on the paper loading tray 210 , picked up sheet by sheet by the paper pickup roller 220 , and transferred toward the paper feed roller 230 . The paper feed roller 230 may align the paper and supply the aligned paper to the printing unit 240 . The printing unit 240 may include, in this so called ink-jet printing example, a print head 241 having a nozzle through which droplets of ink may be sprayed. Other types of printing unit, for example, and electro-photographic type printing unit may alternatively be used. In the ink-jet type example, the printing unit 240 may print an image on the paper while reciprocating in a width direction of the transferred paper. The paper discharge roller 250 may discharge the paper to the outside of the main body 10 through a paper discharge port 12 .
An upper cover 20 may be installed on the main body 10 . The upper cover 20 may be rotatably coupled to the main body 10 through a hinge shaft 21 disposed at one end portion of the upper cover 20 , or it may be coupled by some other means. A number of control keys 22 may be disposed on a surface of the upper cover 20 to allow a user to control the multi-functional machine 1 .
A document feed path 123 of the image reading apparatus 100 may be defined between an upper surface 11 of the main body 10 and the upper cover 20 . A user may separate the upper cover 20 from the main body 10 to remove a document jammed in the document feed path 123 or to clean various parts installed on the inside of the main body 10 .
The image reading apparatus 100 may include a reading unit 110 which reads image information from the document, and an automatic document feeder 120 , which may automatically feeds the document to enable a continuous reading operation.
The reading unit 110 may be disposed on the document feed path 123 . As shown in FIG. 3 , the reading unit 110 may include a reading sensor 111 , which reads image information from the document fed from the automatic document feeder 120 , and a glass portion 112 , which is disposed on the reading sensor 111 to be in contact with the document. The glass portion 112 may be made of any transparent material that allows the information on the document to pass to the reading sensor 111 . The reading sensor 111 may employ a contact image sensor (CIS), a charge coupled device (CCD), or other imaging sensor.
The automatic document feeder 120 may include a document inlet 121 , which receives the document, a document outlet 122 which discharges the document, a document feed path 123 provided between the document inlet 121 and the document outlet 122 , and rollers which may be disposed on the document feed path 123 to feed the document. The document inlet 121 may be disposed on one side of the document feed path 123 . The document outlet 122 may be disposed on an opposing side of the document feed path 123 . A document loading tray 124 , on which a document D may be loaded, may be disposed adjacent to the document inlet 121 . The document feed path 123 may be inclined toward the document outlet 122 from the document inlet 121 .
The rollers adapted to feed the document may include a document feed roller 125 , which picks up a document D loaded on the document loading tray 124 sheet by sheet to supply the document D to the document feed path 123 , and a white roller 126 , which feeds the document through the document feed path 123 . The white roller 126 may face the reading unit 110 , and maintain the document in contact with the glass portion 112 . The white roller 126 and the reading unit 110 may be disposed in proximity to the document outlet 122 . According to an embodiment, the white roller 126 may be disposed above the reading unit 112 . After the rear end portion of the document passes the location where the white roller 126 is nearest to the glass portion 112 , the document no longer receives a discharging force from the white roller 126 . When the document being discharged encounters a sufficient friction with the surface B (see FIG. 4 ), onto which the document is being discharged or with other documents already piled on the surface B, the document may remain in the document outlet 122 without being fully discharged.
FIGS. 1 to 3 depict an embodiment, in which the image reading apparatus 100 may include at least one guide member 130 , which may generate a widthwise curl on the trailing end of the document as the document is being discharged through the document outlet 122 . When the document fails to be fully discharged, the curl of the document may allow a next discharged document to push the stalled document through the document outlet 122 .
In one embodiment of the invention, the at least one guide member 130 may include a first guide rib 131 and a second guide rib 132 which are disposed at the document outlet 122 . The first guide rib 131 and the second guide rib 132 may protrude toward the document feed path 123 and lift the document by interfering with the document as it is discharged through the document outlet 122 . The first guide rib 131 and the second guide rib 132 may have a guide surface 133 facing the document feed path 123 . The guide surface 133 guides the leading end of the document moving through the document feed path 123 such that the document may smoothly pass over the first guide rib 131 and the second guide rib 132 . As seen in the embodiment shown in FIG. 3 , the guide surface 133 may be formed in a convexly curved surface inclined upward in the moving direction of the document.
The first guide rib 131 may be disposed at one side of the document outlet 122 to slightly lift up one widthwise end portion of the document discharged through the document outlet 122 , and the second guide rib 132 may be disposed at the other side of the document outlet 122 to slightly lift up the other end portion of the document. When the trailing end portion of the document is lifted up by the first guide rib 131 and the second guide rib 132 , the trailing end portion of the document is unstably supported in the document outlet 122 , and the document can be easily separated from the document outlet 122 .
FIG. 4 illustrates an example of a document discharge process according to an embodiment of the invention. A trailing end portion DT of a document D 1 may remain in the document outlet 122 . The curl generated on the trailing end portion DT of the document D 1 by the first guide rib 131 and the second guide rib 132 may allow the leading end portion DL of the next discharged document D 2 to push the document D 1 through the document outlet 122 . Thus, it is possible to prevent a document jam or shuffle.
FIG. 5 depicts an alternate embodiment of the invention. In this embodiment, a multi-functional machine 2 may include a first guide rib 131 a and a second guide rib 132 a which are disposed at central portions of the document outlet 122 to slightly lift a central portion of the document discharged through the document outlet 122 . Although this embodiment has a difference in the shape of the curl generated in the document from the embodiment of FIG. 2 , namely the direction of the curl, the document discharging is carried out in substantially the same manner as the embodiment of FIG. 2 and FIG. 4 . That is, when a document is stalled at the document outlet 122 , the curl generated on the trailing end portion DT of the document D 1 by the first guide rib 131 a and the second guide rib 132 a may allow a leading end portion DL of the next discharged document D 2 to push the document D 1 through the document outlet 122 .
Although two guide ribs are installed on the document outlet in the above embodiments, the number of the guide ribs may vary. For example, the embodiment shown in FIG. 6 contains one guide rib 131 c installed on the document outlet 122 . The guide rib 131 c may be installed at the central portion of the document outlet 122 to slightly lift up the central portion of the document discharged through the document outlet 122 , and produce a curl. However, the guide rib 131 c may alternatively be disposed on the left or right side of the document outlet 122 , and perform substantially the same function.
Although embodiments of the present invention have been shown and described, those skilled in the art can appreciate that changes may be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.
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An image reading apparatus with a structure capable of reliably discharging a document, and a multi-functional machine having the same are disclosed. The image reading apparatus includes a document feed path having a document outlet, a reading unit which reads an image of a document fed through the document feed path, and a guide member which is disposed at the document outlet downstream of the reading unit to form a curl on the trailing end portion of the document. The curl formed on the document may make it possible for a subsequent document being discharged to push the curled document out of the document outlet.
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This is a division of application Ser. No. 670,169, filed 11/13/84, now U.S. Pat. No. 4,597,787 granted 7/1/86.
FIELD OF THE INVENTION
The invention is concerned with the manufacture of so-called optical fibres also known as optical waveguides which are used as transmission lines in data communication transmissions and systems. Such fibres may have a radially varying composition such that the refractive index increases in a continuous or stepped manner for the periphery to the core.
DESCRIPTION OF THE PRIOR ART
Optical fibres may be produced from so-called preforms, e.g. in apparatus known in the art as "drawing tower" in which the preform is heated to the softening temperature and a fibre is drawn therefrom. By way of example, a preform having a usable length of 75 cm and a diameter of about 16 mm may be drawn into a continuous fibre of 8 to 10 km length.
By one known process, the so-called inside process preforms are made from high purity silica tubes serving as starting members by depositing on the inner surface thereof successive light transmitting layers of varying compositions such that in the end product the index of refraction increases from the periphery inwards. After the said deposition operation, the tube is caused to collapse into a cylindrical rod.
Thus it is known to produce preforms having a cladding of fused silica and a core of doped fused silica (see for example U.S. Pat. No. 3,619,915 assigned to Corning Glass Works). According to a known process for making such preforms pure silica particles are formed into a continuous transparent phase by a high temperature fusion operation, the required temperature being close to the softening point of pure silica, i.e. about 1600° to 1700° C. Where the fusion takes place inside the silica tube, the latter is likely to deform in consequence of such high temperatures.
By another known method a transparent silica layer is deposited on the inner face of a suitable silica tube by means of a heterogeneous chemical vapor deposition (CVD) operation using plasma activated by radio frequency or a microwave cavity to provide the necessary energy. The reaction takes place on the inner face of the tube and a solid transparent layer is formed instantaneously. The tube wall is kept at a temperature of 800° to 1200° C. in order to ensure the desired quality of the deposited silica layer. This process is expensive and cumbersome.
Two typical methods for the production of optical fibre preforms are described in U.S. Pat. No. 3,823,995 (Corning Glass Works) and U.S. Pat. No. 4,217,027 (Bell Telephone Laboratories Inc.).
The said Corning patent describes a method of forming an optical fibre preform comprising applying to a substantially cylindrical tubular starting member having a smooth inside surface a plurality of distinct and successive layers of particulate material, each of which has a different composition from the preceding layer so as to form a structure having a stepped, radially varying composition. The tubular product obtained in this way is then collapsed into a rod and the latter is subjected to a fibre drawing operation. For the deposition of the individual layers a number of techniques are mentioned such as radio frequency sputtering, deposition of soot by the flame hydrolysis method which is then sintered, chemical vapor deposition (CVD) and deposition of a glass frit. All these methods involve by definition fusing of pure silica particles or slightly doped silica particles in order to obtain continuous transparent layers, fusion temperatures of 1600° C. or even higher being required. Because of the high temperatures required to consolidate pure silica particles, the practical performance of the CVD method in the manner described in the Corning patent is difficult and cumbersome because under such high temperatures the tube is liable to deform, especially if deposition is effected inside the tube, and special means and precautions have to be applied to avoid deformation.
The Bell patent discloses a specific technique referred to in the art as modified chemical vapor deposition (MCVD). According to that method a moving stream of a vapor mixture including at least one compound that is a glass-forming precursor and an oxidizing medium is introduced into a silica tube while heating the tube so as to react the said mixture and produce glassy particles in the gas phase which form a deposit on the inner surface of the tube, the heating of the tube and the contents being effected by a moving hot zone produced by a correspondingly moving heat source external to the tube, combustion within the tube being avoided and the temperature within the hot zone, the composition of vapor mixture and the rate of introduction of the vapor mixture being maintained at values such that at least a part of the reaction takes place within the gaseous mixture at a position spaced from the inner walls of the tube thereby producing a suspension of oxidic reaction product particulate material, whereby the particulate material while travelling downstream comes to rest on the inner surface of the tube. Here again the temperature required for the fusion of the particulate material prevailing near the inner surface of the tube is of the order of 1600° C. or higher, and the final multi-layer product has to be collapsed into a rod which is then drawn into an optical fibre. Similar as in the Corning process also in the MCVD process it is difficult to form inside the tube a transparent pure silica layer because of the high temperatures required.
A common feature to all prior art products and processes for the production of an optical fibre preform by fusion of particulate silica is the operation at an elevated temperature of about 1600° C. or even higher, such temperatures being required in order to achieve vitrification of the initial particulate material deposited on the inner wall of the tube so as to form a continuous homogenous transparent silica glass layer. However such a high temperature may produce initial viscous deformation in the glass tube which is a substantial cause for geometrical instability during the collapse of the tube into a rod, resulting in an eliptical cross-section of the preform and consequently also of the fibre drawn therefrom, which seriously damages the signal transmission capabilities of the fibre.
Moreover, in known processes such as the Corning and Bell processes the deposition efficiency is quite low and for some silica dopant such as Ge may be as low as 10%, which is due mainly to undeposited vaporous reaction products which escape with the residual gases leaving the tube. Also the said Corning and Bell processes as well as other CVD processes activated by plasma or otherwise were conceived at a time when it was quite difficult to obtain high purity materials, and therefore it was advantageous to use methods such as CVD or MCVD which result in very pure reaction products. Nowadays in view of the fast growing need for high purity electronic grade materials, such materials are readily available and can be used directly for the production of optical fibre preforms.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a process for the production of optical fibre preforms using a commercially available silica tube as starting member and conducting the deposition in such a way and at such temperatures that the tube is not deformed during the deposition operation. It is another object of the invention to devise the production of optical fibre preforms in such a way as to avoid the intermediary formation of particulate material, e.g. particulate silica, and thereby to avoid fusion of particulate material. It is a further object of the present invention to provide a process as specified with a higher deposition efficiency than in accordance with the prior art.
In accordance with the invention there is provided a process for the production of an optical fibre preform comprising depositing on the inner surface of a silica tube at least one layer of material that is transparent to the light to be guided by the optical fibre to be drawn from the preform such that the index of refraction increases from the periphery towards the interior, and upon completion of the deposition collapsing the tube into a rod, characterised by a cycle of operations comprising:
(i) establishing a system comprising said tube and at one end thereof (feed end) a vessel with at least one chamber holding material to be deposited on the inner wall of the tube, said material being characterised in that under the operative pressure and temperature the transition from the gaseous to the solid phase leads through the liquid phase;
(ii) establishing inside said system a reduced pressure within the range of 10 -8 to 10 3 microns Hg;
(iii) heating said system to a temperature of 900° to 1500° C. thereby to cause evaporation of said material from said chamber to the tube, the vacuum inside the system being so controlled that evaporation occurs at a temperature at which the tube does not deform in any appreciable manner;
(iv) creating a cooler zone inside said tube by external cooling which cooler zone is moved in uniform axial motion from the far (exhaust) end of the tube towards the feed end thereof thereby to cause deposition of the evaporated material by condensation as a viscous liquid layer on the inner surface of the tube; and
(v) causing said viscous layer to solidify.
Where the deposited material is in an oxidizable form, e.g. elemental silicon, germanium and the like, the invention further provides that upon completion of said deposition pure oxygen is continously flown through the system in the direction from the feed end towards the exhaust end thereof thereby to cause oxidation of said deposited layer.
Evaporation of the material inside said chamber may be enhanced by supplying additional non-thermal energy such as electron beams, RF microwaves, etc. Such additional energy is not absorbed by the silica tube and where the material to be evaporated is, for example, a metal such as Si or Ge, it is taken up by the metal whereby the rate of evaporation is significantly increased.
The materials used in the new process for the manufacture of optical fibre preforms in accordance with the invention have all the common feature that within the specified vacuum range their melting temperature is lower than their evaporation temperature, the latter being less than 1500° C.
Inside the cooler zone the temperature is selected to be below the boiling point and in consequence the evaporated hot gases are condensed as liquid layers on the selected cooler zone of the inside face of the silica tube. The formation of such a characteristic liquid layer is substantially different from known processes in which a particulate material is deposited in the tube.
Thus in accordance with the invention the evaporation of the material to be deposited and deposition thereof inside the tube are physical phenomena which proceed essentially without any chemical reaction in the vapor phase. The new method for manufacture of optical fibre preforms and consequently also the manufacture of the optical fibres themselves is accordingly fundamentally distinguished from the known CVD and MCVD or plasma CVD methods in which the deposition occurs concurrently with a chemical reaction in the vapor phase. Accordingly the new method according to the invention will be referred to hereinafter as physical vapor deposition (PVD) as opposed to the prior art chemical vapor deposition (CVD) and modified chemical vapor deposition (MCVD). Further details on physical vapor deposition processes are given in "Vapor Deposition" by Powell, Oxley and Blecher, 1966 and "Handbook of Thin Film Technology" by Maissel and Glang, 1970 (McGraw Hill Book Co., Inc.).
In practice the chamber or chambers will also be of silica and preferably a vessel holding one or several such chambers is fused together with the silica tube into one continuous system. The tube itself may, for example, have an outside diameter of up to 40 mm and a thickness to outside diameter ratio of from 1:20 to 1:4.
The material for deposition to be placed inside said chamber or chambers will as a rule be solid and may for example be in the form of a powder or filament and be placed into the chambers either directly or by means of a carrier vessel such as, for example, a carrying boat.
During operation the tube-chamber system is preferably rotated continuously about its longitudinal axis at a uniform speed of revolution ranging, for example, from 10 to 200 rpm.
Where in accordance with the invention it is desired to produce a multi-layer preform comprising two or more different layers, it is possible to repeat the operation several times, each time with a different material. It is also possible to make a closed system with two or more chambers, to load into each of them a different material such that the one with the lowest boiling point will be closest to the tube and the one with the highest boiling point will be furthest away from the tube. The operation will then be repeated in cycles, the operational temperatures being raised and/or the operational pressure being further reduced from one cycle to the next.
Where evaporation of the material is enhanced by auxiliary means such as RF, microwaves an electron beam etc. as specified, the source of such additional energy may be in the form of a ring surrounding the tube. Initially the ring is placed around the chamber holding the material to be evaporated so as to enhance evaporation and then the ring may be moved several times back and forth along the tube so as to facilitate even distribution of the vapour inside the tube prior to condensation.
In accordance with one embodiment of the invention the material to be evaporated is introduced into the tube in form of a filament and is spun in axial direction inside the tube in the chamber between vacuum-tight terminals so as to be connectable outside the chamber to an electric current supply. When electric current is passed through the filament the rate of evaporation is increased.
Due to the fact that in accordance with the invention the entire operation is conducted in a sealed system under reduced pressure the evaporation temperature becomes sufficiently low so as not to deform the tube and the deposition efficiency in each layer is close to 100%, as opposed to much higher reaction temperatures and considerably lower deposition efficiencies--occasionally as low as 10%--in the CVD and MCVD method.
In addition to oxygen it is also possible, if desired, to pass other gases through the system after the deposition of said liquid viscous layer, either prior to or after the flow of oxygen. Examples of such gases are fluorine and chlorine and they may serve to create by chemical reaction dopants or getters inside the deposited layers.
Examples of materials that can be deposited as liquid layer condensate by the PVD method according to the invention are pure metals of Si and Ge and combinations thereof. These materials are oxidized after being deposited. Examples of oxides that can be deposited by the PVD method are B 2 O 3 . The melting point and various boiling points in vacuo of these materials are shown in Table "A" together with the evaporation rate equation.
TABLE "A"______________________________________ Equilibrium Pressure P* in microns Hg (columnMater- M.P. heads) B.P. °C. (columns)ial °C. 40 30 20 10 5 0.7 0.5 0.4______________________________________Si 1410 1430 1410(Ref 1)Si 1580 1450 1430 1415(Ref 2)Ge 937 1530 1505 1460 1430(Ref 1)Ge 1440 1410(Ref 2)B.sub.2 O.sub.3 460 1270 1255(Ref 1)______________________________________ Ref. 1 = "Balzers" Catalogue "Coating Materials" 84/86 (published by Balzers A.G., Lichtenstein) Ref. 2 = "Handbook of Thin Film Technology" by Maissel and Glang (1970), McGraw Hill Book Co., Inc.
The evaporation rate equation is (Ref. 2) ##EQU1## dN e =number of molecules having an individual mass m evaporating from surface area A e during time dt at temperature T(°k) at which the equilibrium pressure is P*, under vacuum P (k is the Bolzman coefficient).
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described with reference to the annexed drawings in which:
FIG. 1 is a diagrammatic elevation of an apparatus for carrying out the method according to the invention;
FIG. 2 is a cross-section through a hollow silica tube with inner deposits according to the invention; and
FIG. 3 is a fragment of a collapsed preform rod made from a hollow tube according to FIG. 2.
DESCRIPTION OF PREFERRED EMBODIMENTS
The apparatus shown in FIG. 1 comprises an oblong furnace 1 within which is located a silica tube 2 having fused to its feed end a vessel 3 comprising three aligned chambers 4, 5 and 6, each chamber having a valved control inlet for charging the material to be evaporated. The assembly 2,3 is fitted at both ends with tubular extensions 7 and 8 having mounted thereon pulleys 9 and 10 for connection by mechanical means such as belts (not shown) to a driving motor (not shown) whereby the assembly 2,3 is rotatable about its longitudinal axis. Near the feed and exhaust ends of assembly 2,3 there are provided control valves 11 and 12, respectively.
At their ends the tubular extensions 7 and 8 are connected to links 13 and 14, respectively, each of which is so designed that while the assembly 2,3 rotates the connector remains static. The other end of connector member 13 is connected to a manifold 15 fitted with control valves 16, 17 and 18 and serving for the supply of gases. The exhaust side of connector member 14 leads to a vacuum pump and exhaust.
Furnace 1 is fitted with a plurality of nipples 19 (only some of which are shown), each nipple 19 being connected via a hose 20 to a supply of cold gas which is adapted for injection of cold gas into the furnace. All nipples may be automatically opened in a predetermined sequence and rate by programmed control means as known per se (not shown).
The apparatus further comprises an annular source of non-thermal energy 24, e.g. a resonator adapted (in a manner not shown) to travel back and forth along the assembly 2,3.
The PVD operation with an apparatus according to FIG. 1 proceeds as follows:
Assuming that it is desired to produce two layers, a first layer of pure silica and a second one of silica doped with germania (GeO 2 ) which serves to increase the refractive index, a silicon powder is introduced into chamber 6, valve 11 is sealed while valve 12 remains open and a desired vacuum is applied e.g. of the order of 0.4 micron Hg. The temperature of furnace 1 is set at 1450° C. whereupon the Si boils and evaporates into the silica tube 2.
Optionally additional, non-thermal energy may be introduced by means of resonator 24 whereby while it is positioned around the evaporation chamber, the rate of evaporation is increased. Upon completion of the evaporation and prior to cooling (see below) the annular resonator 24 may be moved back and forth along tube 2 in order to facilitate even distribution of vapour inside the tube.
In FIG. 1, furnace 1 is shown to have two zones A and B, zone A being the hot zone and zone B the cooler zone. The temperature inside zone B is reduced by the injection of a cooling gas via hoses 20 and nipples 19. At the beginning of the operation the length L of zone B is 0 and a short while after the beginning of the boiling of silicon inside chamber 6, cooling gas is successively injected into the various nipples 19 beginning with the rightmost one and gradually progressing from right to left (with reference to FIG. 1). In this way the interface 21 between the hot zone A and the cooler zone B moves gradually and in uniform motion from right to left so that the length L of zone B increases while the length of zone A gradually diminishes and the operation is so conducted that upon termination of the evaporation of silicon from chamber 6 the interface 21 has reached that chamber. In the particular case of silicon the cooling operation is so controlled that the temperature prevailing inside zone B around the tube 2 is 1415° C. At this temperature pure silicon condenses on the inner side of tube 2 in the form of a viscous liquid.
Upon termination of liquid silicon deposition on the inner side of tube 2 valves 17 and 11 are opened and pure oxygen is passed through the system 2,3 whereby the silicon is oxidized into silica SiO 2 .
In a second stage germanium power is introduced into chamber 5 and the operation is repeated, valves 17 and 11 being shut, the pressure inside the system 2,3 being now set at 10 microns Hg. The GeO 2 that forms upon oxidation of the initially deposited germanium diffuses partly into the SiO 2 substrate and the duration and temperatures of operation may be so controlled that in the end result there form two layers 22 and 23, the former being of pure SiO 2 and the latter of SiO 2 doped with GeO 2 . Alternatively it is possible to conduct the process in such a way that the GeO 2 diffuses homogenously into the entire SiO 2 layer to form a uniform GeO 2 doped SiO 2 layer.
Inlets 16 and 18 of manifold 15 serve for the optional introduction of other gases. Thus, for example, chlorine may be injected through valves 16 at the beginning of the operation for the complete dehydration of tube 2. Where this is not practical because of the corrosive effect of chlorine, nitrogen may be used instead.
Valve 18 may serve for the introduction of fluorine, to produce in situ silicon fluoride as dopant of the cladding layer, in order to obtain, if desired a layer with a refractive index smaller than that of undoped silica.
The two cladding layers produced by the two-stage cladding operation described above are shown in FIG. 2. At the end of the cladding operation the furnace 1 is removed from the system 2,3 and tube 2 is severed from vessel 3 and is then collapsed in a manner known per se to produce a rod as shown in FIG. 3.
The invention is further illustrated by the following examples. In these Examples all indications of rates of layer formation are theoretical averages.
EXAMPLE 1
An apparatus was used as in FIG. 1 comprising three chambers. Chamber 6 was charged with 14 gr of pure fine Si powder (average particle diameter 40 microns), having properties as shown in Table "A" (Ref. 2). The silica tube was 1 meter long, the outer diameter was 25 mm and the wall thickness 3 mm. The furnace temperature was maintained at 1450° C. (P*=0.7 microns Hg). The sealed system was evacuated to a vacuum of 0.4 micron Hg and revolved at a speed of 60 rpm. The gas cooling device was set to create a cool zone "B" having a temperature of 1410° C. or less, the front of which moved towards chamber 6 at a speed of 2 cm/min. A silicon layer was condensed on the inner wall of the tube in zone "B" at the rate of about 100 microns/h along the tube and at the end of one hour of evaporation a layer of pure silicon of 0.1 mm had formed. The oxidation into silica was performed by introducing pure oxygen gas at a rate of 0.5 lit/min at 1100° C. Oxidation was completed after 15 min. A 100 microns thick layer of pure clear silica resulted along the tube.
EXAMPLE 2
The product tube of Example 1 was used for further cladding. 1 gr of pure Germanium powder (average particle diameter=80μ and having properties as in Table "A" (Ref. 2)) was charged into chamber 5 and the process described in Example 1 was repeated, setting the vacuum at 10 microns Hg and maintaining the furnace temperature at 1440° C., P* being 20 microns Hg. The process rates were as in Example 1, except that the rate of travelling of zone "B" was 18 cm/min, and in this way a 7 micron thick liquid Ge layer was initially obtained along the tube which was then converted into in GeO 2 by oxidation conducted similar as in Example 1.
During oxidation, the GeO 2 was diffused into the deposited SiO 2 layer, resulting in an outer transparent GeO 2 doped SiO 2 layer with a higher index of refraction in comparison to the underlying pure silica layer.
EXAMPLE 3
In a first cycle the process was conducted as in Example 1 followed by a second cycle as in Example 2 using, however, only 0.1 gr of Ge and the process rates were changed accordingly. In a third cycle Example 1 was repeated with parameters adjusted for a 50 micron layer and in a fourth cycle Example 2 was repeated with 0.2 gr of Ge and the process rates being adjusted accordingly. Further cycles followed in a similar way to yield the desired number of layers and the amount of Ge was increased each time to obtain richer GeO 2 doping, thereby obtaining a so-called graded refraction index profile.
EXAMPLE 4
Codeposition of Si and Ge. 14 gr Si was charged into chamber 6 and 1 gr Ge into chamber 5. At first the vacuum was set at 10 microns Hg until all the germanium was evaporated and condensed and then at 0.4 microns Hg. whereupon Si was evaporated and condensed. There then followed oxidation and in this way a GeO 2 doped SiO 2 layer was obtained.
EXAMPLE 5
Codeposition of several layers. Si and Ge were charged into chambers 6 and 5, respectively. In order to obtain grading of the refraction index evaporation was started at a lower vacuum and temperature of zone "A" and raised gradually after each pass of zone "B" up to the upper limit of 1450° C. and 0.1 microns Hg, whereby the relative rates of evaporation of Si and Ge were changed. Each pass of the cooling zone "B" was followed by an oxidation step. In this way successive layers of varying composition and indices of refraction were formed resulting from the gradual change of the amount of GeO 2 in SiO 2 such that the indices of refraction increased gradually from the periphery towards the centre.
EXAMPLE 6
The procedure of Example 1 was repeated with, however, additional non-thermal energy supply, e.g. by means of a resonator like 24 in FIG. 1 which is operated in the manner described with reference in FIG. 1. All Si was evaporated within 5 min. The front of zone B (FIG. 1) moved at a rate of 10 cm/min. and a Si layer was formed at a rate of 10 microns/min.
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Manufacture of optical fibre preforms. A material such as Si, Ge and B 2 O 3 is evaporated in vacuo into a silica tube and is made to condense therein as a viscous liquid which is then oxidized. The operation may be repeated several times with different materials. In this way the tube is clad from within in such a way that the optical index of refraction increases from the periphery inwards. Upon completion of the cladding the tube is collapsed into a rod which is then used for drawing optical fibres.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a high molecular weight polyether polyol, and more particularly to a high molecular weight polyoxyalkylene polyol and the method of preparing same.
2. Description of the Prior Art
The maximum molecular weight of base catalyzed oxide polymer is limited by the ratio of the rate of propagation to transfer. Therefore, only limited molecular weights of these products can be achieved by a direct oxyalkylation reaction. To obtain products of higher molecular weight other chemical methods are necessary.
One of these methods is by reaction with bis epoxides, as disclosed in U.S. Pat. No. 2,990,396. This patent discloses the reaction of polyoxyalkylene polyols with an organic polyepoxide compound. Wide ranges of products are obtained depending upon the ratio of polyepoxide to polyoxyalkylene polyol. Each time an interaction of an alcohol group of the polyoxyalkylene polyol with an epoxy group occurs, a secondary alcohol group is created which can react with epoxide to provide cross-linking. This is particularly the case when amount of polyepoxide is in a large excess over equivalent amounts, and the patent is directed primarily to these cross-linked products.
SUMMARY OF THE INVENTION
It has now been found that excellent high molecular weight polyoxyalkylene polyols are obtained when cross-linking is minimized. In this way, high molecular weight polyoxyalkylene polyols are prepared which are closely related to the structure of high molecular weight polyoxyalkylene glycols, except that additional secondary alcohol groups are provided at fixed spaced locations on the long chain molecules.
In accordance with the process form of the invention, a polyoxyalkylene glycol is provided in the complete dialcoholate form. Then the dialcoholate is reacted with a diepoxy compound in substantially equivalent amounts under anhydrous conditions. Preferably, the diepoxy compound is an alkylene glycol bis glycidyl ether, or a polyoxyalkylene glycol bis glycidyl ether. In addition, an important process step is the bringing together of both reactants all at once under appropriate agitation. After the reaction is completed, the alcoholate groups can be converted back to alcohol groups by ion exchange or acid neutralization.
It has been found that the use of catalytic amounts of alcoholate does not provide nearly as high molecular weight product as the use of equivalent amounts for the same proportions of polyalkylene glycol and diepoxide through the ranges of excess polyalkylene glycol and equivalent amount. The differences are rather marked, with the equivalent amounts providing polymers several times larger than the catalytic amounts. Studies of the structures show that the catalytic amounts provide branched structures whereas equivalent amounts of alcoholates provide nearly straight chain structures even up to equal proportions of reactants. Excess diepoxide will theoretically provide branching, since the primary alcohol sites are used up by the reaction of equivalent amounts.
Thus it is a primary object of this invention to provide very high molecular weight polyoxyalkylene polyols characterized by long, primarily straight, chain structures. This is achieved by combining three process features in the polymerization reaction. First, the equivalent amounts are used of alkali, i.e., complete conversion of the glycol alcohols to dialcoholates. Second, substantially equivalent amounts of the dialcoholates and diepoxides are used. Finally, all of the diepoxide and the dialcoholate are added substantially all at once with immediate mixing. When these conditions are observed, branch reactions are minimized, and very high molecular weight products are obtained.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The first step in the process of the invention is the conversion of the polyoxyalkylene glycol to the corresponding dialcoholate. This step may be achieved by any of the known methods for converting alcohols of the class involved to alcoholates. Conveniently, the conversion is achieved by reaction with an alkali metal such as sodium, potassium or lithium.
The polyoxyalkylene glycols utilized in this invention are those having the formula:
H--O(RC.sub.2 H.sub.3 --O).sub.n --H
in which R is hydrogen or methyl, and n is an integer high enough to provide a molecular weight for the glycol in excess of 500. It will be appreciated that the molecules in any composition will not be exactly alike and that the values for n may be different integers and will be expressed as an average. Similarly, R may be hydrogen and methyl in the same molecule and the proportions will again be expressed as an average. Thus the class includes polyoxyethylene glycol, polyoxypropylene glycol and polyoxyalkylene glycols in which the alkylene groups are a mixture of ethylene and propylene. These mixed groups may be at random or in blocks. Such compositions are well known and many different ones are available commercially.
The conversion of the alcohol groups to alcoholate groups is preferably carried out by contacting the polyoxyalkylene glycol with an alkali metal in an organic solvent inert to the reactants. Typically, the reaction is carried out in a nitrogen atmosphere under anhydrous conditions to protect the alkali metal and minimize formation of undesirable alkali metal oxides and hydroxides. After the conversion is achieved, compounds are obtained which have the general formula:
M--O(RC.sub.2 H.sub.3 O).sub.n --M
wherein M is an alkali metal such as sodium, potassium or lithium, R is hydrogen or methyl and n is an integer high enough to provide a molecular weight in excess of about 500.
The diepoxy compounds utilized in this invention include ethers having terminal epoxy groups. This class of diepoxide has been found to provide the predominantly long chain products obtainable by this invention. Thus suitable epoxides may be expressed by the formula: ##STR1## wherein Z is --O--; --O(CH 2 ) p --O-- where p is 2-10; or --O(RC 2 H 3 --O) m , where R is hydrogen or methyl, and m is an integer from 1 to 5. The preferred diepoxides are the bis glycidyl ethers of glycols such as ethylene glycol, propylene glycol, diethylene glycol, 1,4-butanediol and the like because they provide units in the final chain similar to those in the polyoxyalkylene glycol reactant.
By way of illustration, it is believed that the following reaction mechanism occurs with the first reaction being as follows: ##STR2## After this coupling, it is noted that a secondary alcoholate group is formed. However, any coupling on this secondary alcoholate group will produce undesirable branching. It will also be appreciated that if the amount of diepoxide is substantially less than equivalent the reaction will terminate at a lower molecular weight because the diepoxide will be used up. For example, an equivalent ratio of 0.5:1.0 should provide an average product containing two polyoxyalkylene glycol units and one unit from the diepoxide, and this is true with or without branching. On the other hand, if the ratio of diepoxide is substantially greater, say 2:1, considerable branching will occur.
When the ratio of reactants is equivalent, it is possible to obtain very high molecular weights. However, this can only happen when branch reactions are minimized, because branch reactions use up the diepoxide equivalence and cause a reduced molecular weight product.
It has been found that when the reaction of polyoxyalkylene glycol and diepoxides of the class defined are reacted with catalytic amounts of an alkali metal such as sodium, considerable branch reactions occur. When equivalent amounts of reactants are used, equivalent amounts of alkali metal provide molecular weights many times as high as with catalytic amounts, with the other reaction conditions being the same. In addition, it is found that if the diepoxide is added gradually, considerable reduction in molecular weight occur. Accordingly, the gradual addition of one reactant to another also causes branch reactions. Therefore, it is important to combine these reactants substantially all at once with rapid mixing.
Straight chain products prepared according to the reaction of the invention would have the following formula: ##STR3## with y being a large integer, and M, R, Z and n being as defined above.
The last step is the conversion of the alcoholate back to the alcohol form. This may be achieved by any known procedure, such as by cation exchange or simply by acid neutralization. After reconversion, the theoretical formula would be ##STR4## with R, Z, n and y being as hereinabove defined.
When the reaction process is carried out in accordance with the invention, it is believed the high molecular weight product obtained is substantially composed of straight chain molecules. However, it is likely that at least some branching occurs, and the exact structures are likely to vary somewhat.
In general, it is preferred to carry out the reaction in the presence of an organic solvent which is inert to the reactants. However, it is possible to carry out the process without using any solvent. Typical solvents that may be employed include xylene, toluene, the diethyl ethers of ethylene and diethylene glycol, and dioxane. The reaction temperature is not critical, and may range from about 25° to about 250° C. Preferably, the temperature is kept between 50° and 150° C., and is conveniently carried out at the reflux temperature of the mixture in the solvent utilized. The pressure is not critical, and therefore the reaction will usually be conducted at atmospheric pressure.
Typically, the reaction will be carried out in a nitrogen atmosphere. In addition, care should be taken to retain all ingredients in an anhydrous condition until the final step of converting the alcoholate groups back to alcohol.
The products obtained are not only of high molecular weight, but are generally water soluble. This is true even with products made from certain polyoxypropylene polyols, which are hydrophobic as starting materials, probably due to the higher oxygen:carbon ratio in the selected diepoxides used and the secondary alcohol groups. Therefore, the highly viscous products may be used as hydrolubes. In addition, the products may be used for making further resins through the polyol groups such as polyesters and polyurethanes. The products also have good lubricating qualities, and may be used as suspending, thickening, dispersing, and coagulating agents in aqueous solutions.
The invention described above is more fully illustrated in the following specific examples, in which parts are by weight unless otherwise indicated. The examples are to be interpreted as illustrative only and not in a limiting sense.
EXAMPLE 1
A 1-liter, four-neck flask is provided with a stirrer, nitrogen inlet, a condenser and a collector for azeotrope. 100 grams (0.1 mole) of a polyoxypropylene glycol of about 1000 molecular weight and 400 milliliters of xylene are added to the flask. The mixture is refluxed for about one hour under a nitrogen atmosphere and agitation by stirring to remove traces of water. Then, 4.6 grams (0.2 mole) of sodium metal are added slowly in small pieces and reacted for approximately 6 hours under reflux. A solution of 17.4 grams (0.1 mole) of glycol bis glycidyl ether and 80 milliliters of dry xylene are added all at once. A viscous product is formed quickly, and the reaction mixture is kept for 30 minutes under weak reflux to complete the reaction. This viscous reaction product is then purified by ion exchange. All solvents are evaporated and a yellow, very viscous, water-soluble oil is obtained.
The product is obtained in a yield of 116.6 grams with the maximum theoretical yield being 117.4 grams. The Gardner Viscosity of the product is 14,800-38,000 CST, and the cloud point (1%) is 21°-22° C.
EXAMPLES 1 a-1 k
The procedure of Example 1 is repeated a number of times utilizing the same reactants, but varying the amounts of alkali to illustrate the difference between equivalent amounts and catalytic amounts. In addition, the proportion of reactants, method of addition, and amount of solvent was also varied. The results of these examples are shown in Table I below.
Table I__________________________________________________________________________Polypropylene Glycol GardnerGlycol Na Bis Glycidyl Xylene, Reaction, Viscosity,Example(gms.) (gms.) Ether (gms.) (ml.) Time CST__________________________________________________________________________1 a. 100 4.6 15.3 400 30 min. 14,8001 b. 100 4.6 15.8 1000 1 hr. 3,6201 c. 100 4.6 7.5 400 30 min. 6271 d. 100 4.6 11.8 400 30 min. 1,7601 e. 100 0.43 15.3 400 90 min. 8841 f. 100 0.58 24.2 400 90 min. 2,2701 g. 100 0.46 15.3 400 Dropwise, 627 then 60 min.1 h. 100 4.6 15.3 400 Dropwise, >6,340 then 60 min.1 i. 100 4.6 19.3 400 10 min. Gel1 j. 100 0.46 8.7 400 90 min. 400-4351 k. 500 22.6 65 None 90 min. ˜59,000__________________________________________________________________________
In Examples 1 a-1 d and 1 h, 1 i, and 1 k equivalent amounts of sodium are used; while catalytic amounts are used in Examples 1 e, 1 f, 1 g, and 1 j. A comparison of results illustrates that catalytic amounts of sodium do not provide the desired high molecular weight products. Note that Example 1 a (which has 88% of the equivalent amount of glycol bis glycidyl ether) and Example 1 e differ only in the amount of sodium and the length of reaction time (1 e kept longer), yet the viscosity of the product of Example 1 a is more than 16 times as high as that of Example 1 e. Example 1 b illustrates the effect of excessive solvent, and Examples 1 c and 1 d illustrate the reduction in viscosity when the amounts of glycol bis glycidyl ether is substantially less than the equivalent amount. Examples 1 g and 1 h show the loss in viscosity when the glycol bis glycidyl ether is added dropwise rather than all at once. Example 1 g shows a further decrease in viscosity when the second reactant is added dropwise and catalytic amounts of alkali are used. Comparison of 1 g and 1 e shows reduction in viscosity when the glycol bis glycidyl ether is added dropwise and catalytic amounts of alkali are used. Example 1 i shows the production of a gel very quickly when equivalent amounts of alkali are used and a slight excess (11%) over the equivalent amount of glycol bis glycidyl ether is used. Example 1 k illustrates that the reaction may be carried out without the use of solvents, if desired.
From the above examples it is seen that the desired high molecular weight compound mixture is obtained by observing three important procedures. First, the amount of alkali used is an equivalent amount rather than a catalytic amount. Second, the amount of glycol bis glycidyl ether should be substantially equivalent. Last, the equivalent amounts of glycol bis glycidyl ether and alcoholate should be combined all at once. It is also to be noted that the final product is water soluble even though it is made from hydrophobic polypropylene glycol.
EXAMPLE 2
A 2-liter, four-neck flask is equipped with a stirrer, nitrogen inlet, a condenser and a collector for azeotrope. 400 grams of a polyoxyalkylene glycol and 800 milliliters of xylene are added to the flask. The polyoxyalkylene glycol is a block copolymer of ethylene oxide and propylene oxide having an average molecular weight for its polyoxypropylene blocks of 1750, and having about 80% (by weight) of polyoxyethylene in the total molecule as the terminal portions thereof. Such polyoxyalkylene glycol is a surfactant sold by BASF Wyandotte Corporation of Wyandotte, Michigan, under their PLURONIC trademark as "PLURONIC F-68" polyol. Thus the molecular weight of the polyoxyalkylene glycol is about 8750, and 400 grams is about 0.046 mole, however, it will be appreciated that the molecular weight is an average and that it will vary somewhat. This mixture is refluxed under a nitrogen atmosphere with stirring to remove water traces.
To the refluxed solution is then added 2.3 grams of sodium metal (0.1 mole), and the mixture is reacted for about 6 hours under reflux. Then 7.83 grams (0.09 eq. wt.) of glycol bis glycidyl ether dissolved in 50 milliliters of dry xylene is added all at once at 140° C. and reacted for about 30 minutes. The reaction mixture becomes very viscous. The alcoholate is then neutralized by adding 10 grams of concentrated hydrochloric acid in 500 milliliters of isopropanol. After evaporation, a tough, water-soluble resin is obtained.
The viscosity at a concentration of 5% in water is as follows: Brookfield -- 20° C., Spindle No. 2, 20 RPM = 36 centipoises; Relative Viscosity ην -- 25° C., Tube 200 = 128.5 seconds. The cloud point (1%) is 56°-57° C.
EXAMPLES 2 a-2 f
The procedure of Example 2 is repeated a number of times utilizing the same reactants, but varying the amounts of alkali to illustrate the difference between equivalent amounts and catalytic amounts. In addition, the proportion of reactants and type of solvent was also varied. The results of these examples is shown in Table II below.
Table II__________________________________________________________________________Amount of Amount of ηΓ BrookfieldSodium Diepoxide Solvent Tube 200 Sp. 2, 20° C.Example(gms.) (gms.) 800 ml. 25° C., sec. 20 RPM, CPS CP (1%)__________________________________________________________________________2 a .23 4.35 Xylene 24.2 14 98-99° C.2 b .23 8.7 Xylene 30.2 14 84-85° C2 c 2.3 4.35 Xylene 36.5 14 74-75° C.2 d 2.3 6.52 Xylene 60.0 16 58-59° C.2 e 2.3 8.7 Xylene 236.4 58 56-56.5° C.2 f 2.3 7.83 Toluene 172.8 42 56.5-57° C.__________________________________________________________________________
Table II illustrates that catalytic amounts of alkali do not provide the desired high molecular weight products, whereas substantially equivalent amounts do. In addition, the data shows that the amount of diepoxide should be substantially equivalent to the amount of alcoholate.
From the foregoing description, it is seen that we have shown and described a new composition and process for preparing same. While we have described herein certain embodiments of our invention, we intend to cover as well any change or modification therein which may be made without departing from the spirit and scope of the appended claims.
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New polyether polyols of predetermined structure are prepared by reacting polyether bis alcoholates with selected bis epoxides. Specifically, a polyoxyalkylene glycol is converted to the bis alcoholate, and then the bis alcoholate is reacted with an equivalent amount of a glycol bis glycidyl ether, with the reactants being mixed together all at once. The polyether polyalcoholate thus obtained is converted to a high molecular weight polyether polyol by acid neutralization or ion exchange.
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DEDICATORY CLAUSE
The invention described herein may be manufactured, used and licensed by or for the Government for governmental purposes without the payment to us of any royalties thereon.
BACKGROUND OF THE INVENTION
Remote imaging systems are in use in many applications ranging from convenience store monitoring cameras to sophisticated imaging systems on satellites in space. Such systems typically consist of an imaging sensor comprised of light-gathering optics, a detector array and support electronics that produces an electronic video signal that is transmitted to a remote site for human operator viewing and recording. The imaging sensor is often rotated about one or more axes (usually using a set of gimbals) or translated in space to view an area that is larger than that covered by the sensor's optical field of view. In many systems the gimbals are controlled by gyroscopes to isolate the base motion of the sensor platform from the image, thus providing a stable image for the operator. Often, the sensor optical system contains a zoom lens or switchable elements that allow the field of view to be changed for greater resolution or for a larger field of view coverage. By these means the operator is able to view different portions of the observable space (commonly called the “target space” or “target area”) at the resolutions needed to detect and recognize items of interest. In most applications, the images received from the remote sensor are recorded on videotape for later viewing and/or processing by observers at different remote sites.
Existing remote imaging systems lack the capability to produce much higher resolution and larger field of view combinations without the use of expensive and heavy switchable optical elements and gimbals. Such a combination of concurrent high resolution and large field of view is desired without significant increases in transmission system bandwidth or in degradation of image stability. Further, there is a need to be able to record the images in such a manner that any portion of the imaged target space is viewable almost instantly and can be sent to observers at remote sites. Lastly, all of these needs should be met at a cost that is affordable and scalable, as the application requires.
SUMMARY OF THE INVENTION
The Remote Mosaic Imaging System having High-Resolution, Wide Field-of-View and Low-Bandwidth, hereinafter referred to as the “Remote Mosaic System,” utilizes a plurality of remote sensors to create a plurality of images. Readily available and inexpensive commercial imaging sensors, such as the sensors commonly used in hand-held camera recorders (“camcorders”) can be used to create input images without zoom lenses, field of view-changing mechanisms or gimbals. The use of such sensors significantly decreases the cost of the system while greatly increasing the capabilities of the imaging system to cover virtually any target space with virtually any desired resolution.
Furthermore, as described in detail below, the “Remote Mosaic System” uses image frame synchronization and multiplexing to reduce the bandwidth needed to transmit the plurality of images to a remote location. Because the sensors can be physically mounted on the same platform, the image relationships from one sensor to an adjacent sensor are accurately fixed, thereby easing the subsequent mosaic-processing burden.
DESCRIPTION OF THE DRAWING
FIG. 1 is a diagram of a preferred embodiment of the “Remote Mosaic System.”
FIG. 2 presents a block diagram of the timing generator.
FIG. 3 illustrates the function of multiplexer 12 in detail.
FIG. 4 shows the details of workstation 16 .
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawing wherein like numbers represent like parts in each of the several figures and arrows indicate the direction of signal travel, the following describes in detail the structure and operation of the Remote Mosaic System.
The Remote Mosaic System uses to advantage well-known image mosaicing technologies such as that taught by Peter J. Burt et al in U. S. Pat. No. 5,649,032. Mosaicing is the process of taking a plurality of images that partially overlap and combining or “stitching” them together at the overlap points to form a larger composite, seamless image mosaic.
To date, sensor systems performing mosaicing have used a single imaging sensor to generate the necessary plurality of images that are then combined into the mosaic image. Although this can indeed result in coverage of the target area with good resolution, total coverage can be time consuming because of the number of sensor passes required to cover the target area completely, each pass collecting one “image strip.” Further, if the imaging sensor is mounted on a moving platform such as an airplane, it may be difficult to aim the sensor with the precision required to ensure that the image strips overlap sufficiently for accurate mosaicing. Even though the Remote Mosaic System uses multiple imaging sensors, in some cases it may still be necessary to make multiple passes in order to cover the entire target space due to a large target area or any existing viewing obstructions or low visibility. However, each pass can result in a much wider image strip, thus requiring fewer passes. In addition, with larger image strips, less precision is required to aim the sensor system to ensure strip overlap.
FIG. 1 is a block diagram of a preferred embodiment of the Remote Mosaic System. A pre-selected number, N, of electro-optical imaging sensors 10 , which may be inexpensive commercial imaging sensors, are mounted on a remote sensing platform (not shown in the figure) such that their fields of view of target area 9 overlap by an amount (typically small and shown in the figure as X's in target area 9 ) that is amenable to the mosaicing process. N may be as small as one or as large as needed to fulfill the requirements of the system. The outputs (video frames of the target area) obtained by the sensors are fed simultaneously into multiplexer 12 which, however, allows only one of the sensor outputs to pass through it at a time. The multiplexer also tags each video frame with the sensor number (typically into the vertical blanking area) to indicate which sensor generated which image. This tagging enables the images to be placed correctly in the subsequently resulting mosaic. Timing generator 11 , coupled between each of the imaging sensors and the multiplexer, synchronizes any necessary scanning activities of the N sensors as well as causing multiplexer 12 to progress to the output of the next sensor during the vertical retrace period of the sensors. This ensures that minimum time is lost waiting for the next sensor's start-of-frame. Imaging sensors 10 , timing generator 11 and multiplexer 12 are typically located remotely.
As illustrated in FIG. 2, timing generator 11 is comprised of oscillator 20 , synchronization signal counter 21 , decoder 22 and sensor counter 23 . In operation, oscillator 20 , which may be a typical stable oscillator made of a quartz crystal, outputs a precise series of pulses at a normal video field rate which defines the start of each image segment by an imaging sensor. These pulses are input to synchronization signal counter 21 which, in response to the pulses, outputs parallel digital word that represents a particular image segment from a particular sensor among imaging sensors 10 . The synchronization signal counter resets itself when oscillator 20 has output enough pulses to account for a complete round of image production from all imaging sensors 10 and restarts the counting process for the next complete round of production of input images from the sensors. Decoder 22 receives the parallel digital word from the synchronization signal counter and produces timing signals that are input to imaging sensors 10 to synchronize the production of input images from the sensors. The decoder also produces end-of-frame pulses that are input to sensor counter 23 . The sensor counter is a synchronous digital counter with reset capability that counts the end-of-frame pulses being input from decoder 22 and, when it has received N pulses, resets itself and restarts the counting process. The current sensor number, produced by the sensor counter in response to input from the decoder, represents the i th sensor and is input to multiplexer 12 to cause the multiplexer to transmit therethrough the image from the i th sensor to video transmitter 13 .
FIG. 3 illustrates the function of multiplexer 12 in detail. As shown in FIG. 1, the outputs of the N imaging sensors 10 form the image inputs to Multiplexer 12 , which is composed of electronic switch 30 and mixer 31 . Electronic switch 30 and mixer 31 may be analog devices or digital devices depending on whether the sensor image inputs are analog or digital. Electronic switch 30 and mixer 31 also accept the current sensor number from timing generator 11 . Electronic switch 30 uses the current sensor number to control the position of the switch, thus selecting only one image input to feed into the mixer 31 at any instant of time. The mixer uses the current sensor number to embed a particular signal into the image, thereby tagging the image, prior to transmitting the image to video transmitter 13 . This particular signal can be decoded by image processor 15 to aid the mosaicing process. Because the image from only one imaging sensor is output from multiplexer 12 at any given instant, the system bandwidth is equivalent to that of one of the N imaging sensors 10 .
The tagged output of multiplexer 12 feeds the video transmission system which is typically comprised of conventional video transmitter 13 and video receiver 14 with a suitable transmission medium 7 between the transmitter and receiver. Depending on the application of the Remote Mosaic System, transmission medium 7 could be as simple as air for wireless transmission, a wire connecting multiplexer 12 and image processor 15 or as complex as a satellite orbiting in space. In case of wireless transmission, video transmitter 13 and video receiver 14 can be conventional wireless units such as DSX 2427NA video transmitter and DSR-15249-24 video receiver, respectively, made by Dell Star Technologies, Inc. If standard coaxial cable is chosen as transmission medium 7 , a simple analog video cable driver and receiver (such as a Maxim Integrated Products Inc., part number MAX408) may be used. If imaging sensors 10 have digital outputs, either inherently or by the use of a separate analog-to-digital converter, video transmitter 13 and video receiver 14 may consist of conventional digital modems or conventional Local Area Network (LAN) circuits.
Bandwidth reduction is achieved for the transmission from transmitter 13 to receiver 14 because the transmitter 13 transmits only one image frame at a time and transmits it at the rate at which it is produced. Image processor 15 receives video frames from video receiver 14 one at a time, decodes the sensor number from each video frame it receives and stitches together the frames to form the mosaic according to well-known mosaicing processes such as that taught by Peter J. Burt et al in U.S. Pat. No. 5,649,032. Because all of the classical elements of currently known mosaicing techniques are utilized in the Remote Mosaic System, the invention retains the inherent capability of such techniques to eliminate image instability due to image system platform motion. It further retains the ability to produce a mosaic that effectively results in a compressed digital image. This compressed digital image is rapidly scrollable to any point and any sub-image may be readily extracted from it for transmission to another remote observer.
The output of image processor 15 is input to workstation 16 (a high-performance Windows-based Personal Computer or Unix-based workstation) which contains a high-capacity disk drive. Workstation 16 serves as a temporary storage facility for image processor 15 as the processor builds the mosaic as well as providing the mosaic (both as it is being constructed and post-construction) to display unit 17 which usually is the workstation's normal console display. Both during and post-construction, the operator can scroll and zoom the mosaic to view the portions he needs at the resolution he wants. Further, since the mosaic is already a digital image in the memory of workstation 16 , any portion of the mosaic image can be selected by the operator and sent digitally to other observers.
FIG. 4 shows the details of workstation 16 . Central Processing Unit 40 , when loaded with conventional software, controls the operation of all elements of workstation 16 through computer bus 41 . Graphics board 42 receives mosaic image data from mass storage device 44 , buffers the image in its on-board memory and generates the signals required to drive display unit 17 . Because graphics board 42 contains its own memory, it can cause the mosaic to scroll rapidly through the mosaic image as commanded by the operator through operator interface 45 and central processing unit 40 . Additionally, graphics board 42 can be used to zoom and de-zoom the mosaic image, as the operator requires. Image processor interface board 43 receives mosaic images from image processor 15 and sends them to the mass storage device 44 . In some versions of the invention, it may also be desirable to send portions of a mosaic image from mass storage device 44 to image processor 15 . This may be necessary when processing large mosaic images containing many image strips. Combining a large number of image strips together into a large mosaic often requires a correspondingly large amount of temporary image storage which can be provided economically by mass storage device 44 . In such cases, image processor interface board 43 may transfer these temporary images from mass storage device 44 to image processor 15 . Operator interface 45 may contain a conventional keyboard, mouse, trackball, etc. as required for the operator to interact with workstation 16 . Lastly, display unit 17 may be any conventional video display such as those made by Sony Corporation, ViewSonic Corporation, and others. Because the mosaic image is rapidly scrollable, the resolution of the display need not match the resolution of the mosaic. This allows the use of low cost displays or displays that must be physically small due to weight or size constraints.
Although a particular embodiment and form of this invention has been illustrated, it is apparent that various modifications and embodiments of the invention may be made by those skilled in the art without departing from the scope and spirit of the foregoing disclosure. Accordingly, the scope of the invention should be limited only by the claims appended hereto.
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The Remote Mosaic Imaging System having High-Resolution, Wide Field-of-View and Low Bandwidth (“Remote Mosaic System”) uses image frame synchronization and multiplexing to reduce the bandwidth needed to transmit the plurality of images to a remote location. The Remote Mosaic System employs a plurality of remote sensors to create a plurality of images. The use of readily available and inexpensive commercial imaging sensors significantly decreases the cost of the system while greatly increasing the capabilities of the imaging system to cover virtually any target space with virtually any desired resolution.
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BACKGROUND OF THE INVENTION
The present invention relates to an improved method and apparatus for the calibration and quality control of a spectrophotometer and particularly an ELISA spectrophotometer used in a clinical laboratory.
Spectrophotometers, including micro titer plate readers, are a well known tool in the analytical chemistry laboratory. One type of commercially available spectrophotometer is the ELISA spectrophotometer which typically comprises a plurality of light sources and detectors commonly arranged in a column of eight. The ELISA spectrophotometer can be used to analyze the photometric density produced by assay of biological materials. These assays are arranged as an assay plate having a number of columns corresponding to the number of channels of the ELISA spectrophotometer and a number of rows. Typically the ELISA spectrophotometer comprises an 8×12 matrix of 96 cells. The ELISA spectrophotometer now typically includes a microprocessor analyzing and recording the output of each channel for each assay well of a sample plate.
The ELISA spectrophotometer is a relatively recent addition to the analytical laboratory. An even more recent development has been the introduction of the ELISA spectrophotometer into the clinical laboratory. For example, the immuno-chemical identification of exposure to hepatitis B virus, the Herpes virus, and the HIV virus, and the "AIDS" virus, uses an ELISA spectrophotometer. The significance of photometric measurements made with an ELISA spectrophotometer now have implications that directly relate to the control of infectious epidemics. The measurement integrity of an ELISA spectrophotometer is therefore a matter of considerable concern to laboratory technicians, regulatory agencies and the general public.
The ELISA spectrophotometers used in clinical laboratories, however, are generally not equipped to insure proper calibration or quality control. Calibration is defined as the integrity of the normal operation of the instrument and relates to the spectrophotometer itself. Quality assurance is defined as the integrity of the results produced by a laboratory technician using a properly functioning spectrophotometer. At present, the calibration of an ELISA spectrophotometer is established once at the factory when manufactured. Generally no provision is made for confirming calibration after the spectrophotometer leaves the factory. Quality assurance is left to each individual clinical laboratory and laboratory technician.
The calibration of an ELISA spectrophotometer can be compromised through both electronic and optical errors. Electrical errors arise from a variety of causes. An ELISA spectrophotometer employs filters of predetermined density and color. An electronic mechanism selects among the filters. A failure in the selection mechanism may result in the wrong filter being inserted. A laboratory technician would not notice the malfunction even if he could view the filter.
Alternately, the electronic memory that serves the microprocessor of the ELISA spectrophotometer may fail. Such a failure would most likely remain undetected using current calibration techniques. At present, an ELISA is calibrated by "blanking" the channels to establish a base line for zero optical density. A defective memory would likely read zero during "blanking". Nothing about the reading would necessarily indicate that the ELISA was defective. A memory defect used in the context of HIV screening would preclude the production of any positive test results. Individuals exposed to a virus would test free of infection whether or not such is true.
Yet another source of electronic error is the connection between the ELISA spectrophotometer and its microprocessor. The microprocessor of a personal computer often analyzes the output of the ELISA spectrophotometer and serves as the microprocessor for the ELISA. The transmission line between the spectrophotometer and personal computer normally uses a "hand-shake" protocol in which the photometer generates a check sum which is then exchanged with the computer. However, most programs used to analyze the output of an ELISA spectrophotometer do not analyze the check sum. Any transmission error thus goes unrecognized.
Optical errors can originate from a number of sources. For example, dust can obstruct a channel of an ELISA spectrophotometer and thus reduce its throughput efficiency. Alternately, the light source for a particular channel may become erratic and produce "jumps" in output or "burn hot" and produce a consistently high signal. This type of erratic output cannot be corrected using baseline subtraction.
Yet another source of potential optical error involves the deterioration of the filters of the ELISA spectrophotometer. This deterioration can take many forms such as, for example, the formation of cracks. Filter deterioration which is not necessarily noticed by the human eye can nevertheless give erroneous readings.
Optical errors can produce either false positives or false negatives depending on the test being run. The resulting misdiagnosis is traumatic to the patient involved and results in a substantial expenditure of time and resources to correct.
A second type of error in an ELISA spectrophotometer measurement is human error. A filter could be improperly inserted due to any number of reasons such as improper labeling or a defective selecting mechanism. A laboratory technician also could select the wrong filter for a given measurement. In either event, the error is not readily apparent using base line substraction because the values of the baseline measurements are substantially lower than those corresponding to a sample. Inserting the wrong filter causes all samples in a particular assay to appear "normal". The purpose of the assay is compromised and individuals are again diagnosed as being free of infectious diseases whether or not such is true.
The near total absence of calibration and quality assurance controls for ELISA spectrophotometers is uncharacteristic of the clinical laboratory. Stringent governmental regulation is more the norm than the exception. These regulations typically include frequently documented calibration tests of pipettes, scales, etc. Records must also be kept documenting preventive maintenance performed on the equipment as well as identifying the equipment used to obtain the quality control and calibration measurements. For example, radiochemical procedures use stable radioisotopes in combination with the counting equipment for daily quality assurance and calibration measurements. Records are maintained for review by the appropriate government regulatory agency. Likewise, test tube immunochemical procedures employ a series of sealed test tubes having dilutions of known color for use in a one channel photometer. The quality assurance measurements and calibrations are comparable to that required for radiochemical procedures.
The quality assurance and calibration confirmation procedures employed with a single channel photometer are not adequate for more complicated clinical procedures. For example, primitive "spot-check" calibration and baseline measurements are adequate for an ELISA spectrophotometer when used in an analytical laboratory. A skilled researcher could readily determine if his equipment or his procedure were defective since he would be highly familiar with the equipment and would have some idea of what result to expect. However, the clinical laboratory technician must analyze unknown samples without intuition. Errors are not apparent. Any errors on spectrophotometric measurement become matters of public health concern rather than simply setbacks to research.
A need exists in the art for a method and apparatus for the calibration and quality assurance of ELISA and similar spectrophotometers that will work reliably and quickly in a clinical laboratory. This need was at least partially satisfied by the apparatus for the calibration and quality assurance of ELISA and similar spectrophotometers disclosed in commonly assigned U.S. Pat. No. 4,892,405. In a particular embodiment of the apparatus disclosed in U.S. Pat. No. 4,892,405, color filters are added to the wells of an ELISA sample holder. We have discovered an improved apparatus and method for the calibration and quality assurance of ELISA and similar spectrophotometers.
SUMMARY OF THE INVENTION
The present invention relates to an apparatus for the calibration and quality assurance of a multichannel spectrophotometer, particularly an ELISA spectrophotometer. The apparatus is particularly well adapted for use in a clinical laboratory which performs many repetitive tests on unknown samples. The invention allows the clinical laboratory to keep detailed records of the type normally required by governmental regulatory authorities.
The invention uses a sheet of photographic film, preferably color film with dimensions corresponding to the dimensions of an ELISA sample holder, selectively exposed in the presence of a color filter, to produce a filter or a series of filters that has/have a known first color and linearly increasing optical density. The ability of the photometer to measure this linearly increasing optical density is evaluated b comparing the measurements generated by the photometer to the known increase in optical density from filter to filter. This linearity test also ensures the alignment of the spectrophotometer. Exposure to produce an additional one or more filters of a second color permits checking the color response of the spectrophotometer. An algorithm determines whether the response follows a linear increase in the optical density of the first color and records an appropriate change in optical density using filters of the second color.
The present invention has particular applicability to ELISA spectrophotometry. The ELISA sample holder typically comprises a 8×12 matrix of 96 individual sample wells. Thus preferably the film has about the same dimensions as an ELISA sample holder and is preferably exposed to produce at least part of an 8×12 matrix corresponding to the matrix on the typical ELISA sample holder. If desired the film may be exposed to generate substantially circular filters corresponding to the 12 columns and 8 rows of the sample plate permitting multiple filters for each optical density and color as well as two columns of zero optical density for each row of the photometer. Test results of high quality are thus easily obtained at minimal cost. The optical density of the first color is linearly increased by selectively increasing the length of time the film is exposed to produce the additional filters. The QC plate is thus highly accurate while also being extremely low in cost to produce as well as simple and rugged.
The signals generated by the detectors of the ELISA spectrophotometer using the QC plate are analyzed using algorithms written in the form of a software program and executed on an appropriate computer such as a microprocessor. These algorithms are designed to assure the integrity and consistency. The resulting output is a combined calibration and quality control analysis that instantly informs an operating technician whether the ELISA spectrophotometer is free of a large number of potential sources of error. The resulting output can be printed and retained to satisfy typical governmental regulatory requirements.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an ELISA spectrophotometer;
FIG. 2 shows a top view of an embodiment of the present invention for an ELISA spectrophotometer;
FIG. 3 shows a cross section of an embodiment of the present invention; and
FIGS. 4-6 show a flow chart for analyzing the output of the spectrophotometer generated using an embodiment of the present invention such as depicted in FIG. 2.
DETAILED DESCRIPTION
FIG. 1 shows a conventional ELISA spectrophotometer, EAR 400 FW, manufactured by SLT Labinstruments G.m.b.H, of A-5082 Grodig/Salzburg, Austria. The sample holder 1 is shown in a position prior to being read by the ELISA spectrophotometer. For reading, the sample holder may be fed into the spectrophotometer through a slot 3.
FIG. 2 shows an enlarged view, from the top, of a piece of film, having a length and width about the same as the length and width of an ELISA sample holder. As shown in FIG. 2, the film has been selectively exposed, in the presence of a color filter, to comprise filters corresponding to a plurality of sample wells arranged in a matrix of 8 rows and 12 columns. Preferably, the filters are centered at the point corresponding to the center of each sample well in a standard ELISA sample holder. Also, preferably the diameter of the filters is approximately the same or smaller than the diameter of the sample well, however as will be obvious to those of ordinary skill in the art the filters may have a diameter larger than the diameter of the sample well in a standard ELISA sample holder. As will be also understood by those of ordinary skill in the art, the present invention includes embodiment wherein the film is selectively exposed to produce one or more filters in different size arrays.
The configuration of an 8×12 matrix is standard for an ELISA spectrophotometer. Columns 1 and 2 contain a zero optical density filter that can be produced most simply by not exposing that portion of the film. Columns 3-10 contain linearly increasing densities of the first color optical filter produced by increasing the exposure time of the film. Columns 11 and 12 contain filters of a second color.
FIG. 3 shows a cross section of the film shown in FIG. 2. As shown in FIG. 3, the film may be preferably enclosed in sheet of clear glass or plastic.
FIGS. 4-6 show the flow chart for the preferred analysis to be conducted on the output of the ELISA spectrophotometer using the QC plate shown in FIGS. 2 and 3. The flowcharts implement mathematical operations that are well known in the art as found in Walpole, et al., Probability and Statistics for Engineer and Scientists, McMillan, Inc. (1985), incorporated herein by reference.
Referring to FIG. 4, the program starts at step 300 and inputs an array of numbers at step 310. The array corresponds to the absorbance values obtained from each filter of the QC plate. The data is stored in a 96 element matrix for the embodiment of the present invention shown in FIG. 2. The absorbance values from the 16 elements in the first two columns is averaged and subtracted from each element in the matrix at step 320. This step constitutes the conventional baseline measurement used in prior art analysis routines.
The program of the present invention proceeds to determine a linear regression at step 330 for each row of the matrix, corresponding to at least one channel of the spectrophotometer. The values for the linearly increasing optical density filters are compared against a linear model in the form Y=A+Bx. A statistical determination of the slope for columns 1-10 of each row is computed at step 340. The comparison is performed for each row of the array having linearly increasing optical density filters. The necessary statistics are determined at step 340. These mathematical operations are known in the art and disclosed, for example, on pages 315-31 of Walpole, et al. Whether the slope corresponds to the known value is determined at step 350. If not, flag 1 is set at step 360. At step 370, the Y intercept is compared against its predetermined value of zero. At step 390 the process is reiterated for each row of the QC plate.
Referring to FIG. 5, a two way analysis of variance is conducted on the measurements from the zero optical density filters. The analysis of variance determination is known in the art as disclosed, for example, on pages 393-444 of Walpole, et al. The data for the zero density optical filters in the first column are analyzed to determine whether the average of the first column is significantly different than the average absorbence of the second column. If it is, then a defect exists and flag 3 is set. Then a determination of whether the average absorbence of any row in the first column pair is significantly different than the average absorbence of any other row in the first column pair is made. The significance test itself is known in the art as disclosed, for example, on pages 434-444 of Walpole, et al. If the average values are significantly different, the spectrophotometer is not operating correctly and flag 4 is set. The process is iterated for each column pair of the test data from the QC plate.
Alternatively, referring to FIGS. 5(a) and 5(b) , a coefficient of variation (CV) check and a range check are performed on the measurements from the zero optical density filters. The data for each pair of wells is analyzed to calculate the average of the pair of wells and the coefficient of variation for the wells. Based on pre-established limits for acceptable CV and borderline CV, flags are set to indicate the number of pairs of wells that are unacceptable and the number of pairs of wells that are borderline. If one or more pairs of wells are unacceptable or, two or more pairs of wells are borderline, then a defect exists and flag 3 is set. From the average values calculated, a range is determined. If the range is wider than a pre-established limit, then a defect exists and flag 4 is set. The process is iterated for each column pair of the test data from the QC plate.
Referring to FIG. 6, a conditional step determines whether the absorbance values from the linearly increasing optical density filters really do increase linearly using an analysis of variance on a linear regression model for rows 1-8 and columns 1-10. If not, the spectrophotometer is not operating properly and a flag 5 is set. A non-linear operation of the photometer indicates that it is not operating properly because the QC plate should generate a linear response. Finally, whether the average absorbence values obtained using the second color optical density filter is significantly different from a predetermined standard absorbence value is determined. If there is a significant difference, the spectrophotometer is not operating properly and flag 7 is set. Flags 1-7 are analyzed. An output is generated to indicate whether the photometer is operational. If any of flags 1-7 are set, the output will indicate that the photometer is not operational. Further, the flags 1-7 can be used to generate diagnostic codes to help in determining the source of error in the spectrophotometer.
The foregoing program can be implemented on a standard personal computer. The PC receives its input directly from the spectrophotometer and generates its output using a standard printer. The use of a PC to control an ELISA spectrophotometer is well known in the art.
The foregoing QC plate has numerous advantages over the prior art. Specifically, the sample wells of the QC plate correspond in number and location to those used to make laboratory observations. The ability of the spectrophotometer to position the QC plate is thus checked along with the additional electrical and optical error sources noted in the background to this invention. The accuracy of the calibration and quality assurance check obtained with the ELISA spectrophotometer thus have the accuracy and stability over time normally expected of a clinical laboratory.
EXAMPLE
An apparatus for the calibration and quality assurance of a multichannel spectrophotometer, according to the present invention may be produced as follows.
A piece of color slide film, having a length and width roughly approximating the length and width of a standard ELISA sample well plate, is placed in a holder which will allow the film to be exposed to light.
A mask, formed of a material which blocks the transmission of light, is prepared. The mask has a plurality of substantially circular holes, having a center corresponding to the center of the sample wells in a standard ELISA sample well plate, arranged in an row by 12 column matrix corresponding to the 8 by 12 matrix of a standard ELISA sample well plate. The mask also has means for selectively blocking all or part of the matrix of holes.
The mask is placed over the film in a manner wherein the means for selectively blocking all or part of the matrix of holes in the mask may be manipulated to allow light to pass through all or part of the holes in the matrix to expose portions of the film.
The mask and film are then placed in a chamber, or dark room, wherein the mask and film may be exposed to colored light. To produce an apparatus for the calibration and quality assurance of a multichannel spectrophotometer the blocking means on the mask are moved to expose 2 columns of holes in the 8 by 12 matrix. The mask and film are then exposed to color light for a fixed time period. The blocking means on the mask are then moved to expose an additional 2 columns of holes in the 8 by 12 matrix. The mask and film are then re-exposed to the colored light for an additional time period. Thus, portions of the film corresponding to the first 2 columns of holes in the mask, are exposed twice and portions of the film corresponding to the second 2 columns of holes in the mask are exposed once, thereby creating 2 columns of darker filters on the film and 2 columns of lighter filters on the film. The blocking means on the mask are then moved again to expose an additional 2 columns of holes in the 8 by 12 matrix and the mask and film are re-exposed to color light for an additional time period. This step is repeated until 10 columns of filters are created on the film, with each set of 2 columns being exposed to the color light for a decreasing exposure time. The portion of the film corresponding to the last 2 columns of the 8 by 12 matrix is not exposed to the colored light so that clear filters are produced. The film corresponding to the last 2 columns may be reversed masked to produce substantially circular clear filters corresponding to the last 2 columns of the 8 by 12 matrix of sample wells in a standard ELISA sample well plate.
In this fashion an apparatus for the calibration and quality assurance of a multichannel spectrophotometer is created having an 8 by 12 matrix of filters corresponding to the 8 by 12 matrix of sample wells in a standard ELISA spectrophotometer sample well plate.
By a similar method, the film corresponding to two columns of the 8 by 12 matrix may be exposed to a light of a different color to produce an apparatus according to the present invention having filters of two different colors.
The film thus produced may be encased in clear plastic for protection or used as a "master" to produce additional apparatus for the calibration and quality assurance of a multichannel spectrophotometer.
The principles, preferred embodiments and modes of operation of the present invention have been described in the foregoing specification. The invention which is intended to be protected herein should not, however, be construed as limited to the particular forms described as these are to be regarded as illustrative rather than restrictive. Variations and changes may be made by those skilled in the art without departing from the spirit of the invention. Accordingly, the foregoing detailed description should be considered exemplary in nature and not as limiting to the scope and spirit of the invention set forth in the appended claims.
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An apparatus for the calibration and quality assurance of a multichannel spectrophotometer, particularly an ELISA spectrophotometer, comprises film selectively exposed in the presence of a color to produce a series of filters having a known first color and linearly increasing optical density. The response of the spectrophotometer is measured against the known color and linearly increasing optical density. Additional filters of at least one additional color permit checking the color response of the spectrophotometer. An algorithm determines whether the response conforms to predetermined conditions. An output is produced to provide a record of the calibration and quality assurance of the spectrophotometer. The invention has particular utility for conducting calibration and quality assurance of ELISA spectrophotometers used in clinical laboratory screening for infectious diseases, such as Hepatitis B. and the AIDS viruses.
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