A pivot pin bearing/seal especially adapted for supporting the rotor of a disposable filtration cartridge of a continuous-flow plasmapheresis blood separation system includes a lubricious plastic pivot pin injection molded with a recess at its end. The recess is surrounded by a sharp circular inside edge. A stainless steel eyelet, deep drawn from successive dies, is loosely inserted into the pin recess, a radial outer surface defined at the junction between the eyelet shank and the eyelet flange contacting the pin sharp edge. The eyelet rotates relative to the pin, the circular line path of rotational contact being defined by the smooth curved surface under the flange of the eyelet and the sharp inside edge surrounding the pin recess which quickly burnishes to a good rotational seal. A silicon elastomer seal ring is disposed between the eyelet flange and the rotating filtration rotor to establish a fluid-tight essentially non-rotating seal between the eyelet and the rotor (and therefore causing the eyelet to rotate with the rotor relative to the pin). Coaxial sealing structures may be provided in cascade-type filter cartridges.

Much research and development effort has been devoted to perfecting new and better techniques for filtering biological fluids and for separating the constituent parts of such fluids. Especially important are techniques for separating whole blood into its constituent elements ("hemapheresis"). Although most hemapheresis has been performed in the past by centrifuging batches of whole blood, batch processing is very expensive and time-consuming. Batch processing is now being replaced, wherever possible, by more efficient, continuous-flow blood filtration techniques. See, for example, application Ser. No. 449,470, filed Dec. 13, 1982, entitled "Blood Fractionation System and Method"; application Ser. No. 591,925, filed Mar. 21, 1984, entitled "Method and Apparatus for Separation of Matter from Suspension", abandoned,; U.S. Pat. No. 3,519,201, entitled "Seal Means for Blood Separator and the Like" issued in 1970 to Eisel et al; and U.S. Pat. No. 4,303,193 to Latham, Jr. entitled "Apparatus for Separating Blood into Components Thereof".
Continuous-flow blood filtration systems receive a flow of whole blood from a subject, and couple this blood flow to a rotating rotor or spinner rotatably disposed within a fluid-tight housing. The spinning rotor separates the whole blood into its component parts (e.g., in plasmapheresis, the whole blood is separated into packed red blood cells and plasma), and the separated component parts are discharged through different outlets of the housing.
Others have sought to develop reliable pivot bearing arrangements for rotatably supporting the rotor of a fluid filtration system within a housing -- see, for example, U.S. Pat. No. 3,448,858 to Delcellier et al for an example of one such pivot bearing arrangement. Those developing continuous-flow plasmapheresis devices for commercial production have searched for a suitable inexpensive and reliable pivot pin bearing which can rotatably support a separation rotor within a housing and couple fluid flow to/from the rotor -- and also prevent the coupled fluid flow from escaping from the bearing (except through a fluid discharge outlet) while isolating the coupled fluid flow from fluid outside of the bearing.
Sterility is an absolute requirement in continuous-flow type plasmapheresis devices. It is desirable (if not essential) that parts of the plasmapheresis system which are actually exposed to blood flow be disposable so that disease will not be spread from one donor to another. Known sealing pivot pin bearings which reliably rotatably support the separation rotor within a housing and also couple fluid flow to/from the rotating rotor are relatively expensive to manufacture, increasing the cost of disposable continuous-flow plasmapheresis filtration cartridges.
Because the filtration cartridges are discarded after only one use, extended bearing life is not a concern. Only 25-45 minutes of continuous operation is required for plasmapheresis (the filtration cartridge should have a life of 2 hours if used for plateletapheresis, a life of 4 hours if used for certain therapeutic procedures, and a life of up to 6 hours if used for autotransfusion). The pivot pin bearing must perform absolutely reliably throughout its expected life, since premature excessive wear can make the extracted blood unusable and/or interrupt the extraction and filtration process. The sealing pivot pin bearings used in filtration cartridges must also be sterilizable (e.g., by exposure to gamma radiation), and cannot damage the biological fluid flowing through them.
The assignee of the subject application has searched for years for a reliable, inexpensive bearing structure meeting the above requirements for use in its continuous-flow blood filtration system (of the type disclosed in, for example, U.S. Patent Application Ser. No. 591,925 of Schoendorfer). A brief description of that blood filtration system and the stainless steel pivot pin bearings previously used will now be presented in conjunction with FIG. 1 (although a much more detailed discussion of that system may be found in the above-cited, commonly-assigned U.S. patent application).
FIG. 1 is an elevated, perspective view in partial cross-section of a prior art filtration-type plasmapheresis system 10. Plasmapheresis system 10 includes a disposable filtration cartridge 12 and a magnetic driving assembly 14.
Cartridge 12 includes a generally cylindrical, vertically-oriented housing 16 within which an elongated cylindrical rotor ("spinner") 18 is rotatably supported in a vertical orientation between an upper pivot bearing 20 and a lower pivot bearing 22. Rotor 18 rotates within housing 16 about a generally vertical axis 19 of rotation axial to the rotor.
A ring 24 of magnetic material integral to the upper vertical end 26 of rotor 18 is acted upon by a rotating magnetic field generated by external, rotating magnetic drive member 28 (which slides over the housing upper end), causing rotor 18 to rotate relative to housing 16. Magnetic drive member 28 rotates at a predetermined angular velocity (3600 rpm in the preferred embodiment) in response to torque applied to it by a drive motor 30.
Rotor 18 has an internal cavity 31 within it bounded by a grooved cylindrical wall 34. A membrane-type filter 36 covers the outer surface 35 of grooved wall 34. A network of channels 33 formed in the outer wall surface 35 channels fluid trapped between the filter 36 and the outer wall surface into a lower cavity 32 at the rotor lower end 27.
When system 10 is operating, whole blood is delivered to an upper end 37 of housing 16 via a whole blood inlet port 38. The whole blood flows from inlet port 38 into housing 16 and downward into contact with filter 36. Due to the rotation of rotor 18 and the effect of filter 36, whole blood in the space 40 between filter 36 and an inner wall 42 of housing 16 is separated into packed red blood cells (which remain in space 40), and plasma (which flows through filter 36 into a space between grooved wall 34 and the filter). The packed red blood cells continue to flow downward to the lower end 44 of housing 16 and flow out of the housing through a packed blood cell outlet 46. The plasma is channelled by the grooves in rotor wall 34 and channels 33 and flows downward into lower cavity 32.
A lower cap 48 terminating the lower end 44 of housing 16 defines a bore 50 of predetermined length aligned with the axis 19 of rotor rotation. Bore 50 terminates in a circular interior wall (annulus) 52 having a circular orifice 54 defined through its center (terminating interior annulus 52 blocks all but the center of bore 50).
A plasma outlet 56 is defined in lower cap 48 (in communication with bore 50 at the other side of annulus 52). Plasma is discharged from housing 16 through plasma outlet 56. The lower end 58 of lower pivot pin 22 (the pivot pin being vertically oriented in the embodiment shown) is press-fitted into bore 50 and abuts obstructing annulus 52. The upper end 60 of lower pivot pin 22 is rotatably disposed within a bore 62 at the rotor lower end 64 and aligned with the axis 19 of rotor rotation. Rotor 18 spins with respect to lower pivot pin 22 and is supported above and spaced away from housing lower cap 48 by this pin.
Axial bore 62 defined at the rotor lower end 64 terminates in a ridge or annulus 66 having an orifice 68 defined therethrough. Orifice 68 is in fluid communication with rotor cavity 32. A fluid passageway 70 is defined axially through lower pivot pin 22. An O-ring or other resilient seal 72 (Viton elastomer is preferably used) is disposed between annulus 66 and the upper end 60 of lower pivot pin 22. Seal 72 defines a hole centrally therethrough which communicates orifice 68 with passageway 70. Cavity 32 is thus in fluid communication with plasma outlet 56 via orifice 68, the hole through O-ring 72, passageway 70 defined axially through lower pivot pin 22, and orifice 54.
Lower pivot bearing 22 rotatably supports rotor 18 and provides a sealed fluid passageway through which the plasma within rotor cavity 32 can escape. The lower pivot pin upper end is loosely fitted into bore 62 to permit rotor 18 to rotate relative to the pin--the pin being fixed with respect to housing 16 because it is press-fitted into bore 50. O-ring 72 establishes a fluid-tight seal between annulus 66 and the upper end 60 of lower pivot pin 22 which prevents plasma from escaping from cavity 32 except through pin passageway 70. The fluid-tight seal between annulus 66, O-ring 72 and the pin upper end 60 also prevents packed red blood cells collected in space 40 near the housing lower end 44 from flowing upward into bore 62 (between pin 22 and the wall defining the bore) and into contact with the plasma.
The axial downward force exerted on O-ring 72 by rotor 18 insures that a fluid-tight seal exists between annulus 66 of rotor 18, O-ring 72 and the upper end 60 of lower pin 22. This downward force is derived in part from the force of gravity exerted on rotor 18 and in part from the downward component of the rotating magnetic field exerted on the rotor by magnetic drive member 28. Despite this downward force, pin upper end 60 does not wear appreciably over the life of cartridge 12 if the pin is made of hard stainless steel.
Upper pivot pin 20 may be solid (since no fluid passes through it in the embodiment shown), but preferably has a passageway 84 axially defined therethrough so that the upper pivot pin and lower pivot pin 22 can have the same structure--and are thus interchangeable (to reduce manufacturing, inventory and assembly costs). An O-ring and orifices could be provided at the upper end 26 of rotor 18 (as they are provided at the lower end 64 of the rotor) if fluid coupling through upper pin 20 is desired.
As will now be understood, the fluid-tight seal between annulus 66 of rotor 18 and upper end 60 of lower pivot pin 22 is absolutely critical to the proper operation of system 10. The downward axial force applied to O-ring 72 by rotor 18 can cause the O-ring and/or the upper end 60 of pin 22 to wear, in turn causing the fluid-tight seal to degenerate, if the pin is made of improper material. Leakage of this seal can make the plasma 56 discharged from outlet 56 unusable. Moreover, wear of pin upper end 60 can close passageway 70, interrupting the entire filtration operation (to the distress and discomfort of the donor).
The assignee of the subject invention has used precision stainless steel pins 22 and Viton O-rings 72 in the past to provide pivot pin bearings with great wear resistance which overcome problems caused by wear. Unfortunately, precision stainless steel pins are expensive to manufacture and Viton material is also very expensive--substantially increasing the cost of cartridge 12.
The fabrication of these prior art precision stainless steel pivot pins 20, 22 are described in detail in copending commonly-assigned application Ser. No. 722,707. Initial raw material costs for stainless steel pins are relatively high, and machining, polishing, cleaning and other treatment of the stainless steel to produce a finished pin further increases installed cost. Moreover, a large percentage of completed pins are unacceptable for use because of the very close dimensional tolerances necessary to guarantee proper mating of the pins with rotor 18 and housing 16.
Application Ser. No. 722,797 of Schoendorfer and Williamson, now U.S. Pat. No. 4,675,106, discloses a novel injection-molded plastic pivot bearing design suitable for replacing precision stainless steel pivot pins. Such injection-molded pivot pins are formed from a hard plastic having a low coefficient of friction. By choosing an appropriate plastic material for the pin (e.g., nylon 6/6 and RL 4730 polyamide-based polymer modified with PTFE and silicon), the pin has a lubricious wear-resistant characteristic and will not create "hot spots" on relative rotating parts or shed debris. When used in conjunction with an O-ring seal fabricated of a Viton material (a series of fluoroelastomers based on the copolymer of vinylidene fluoride and hexafluropropylene marketed by Dupont), the force applied by rotor 18 on the lower plastic pin and O-ring together provides adequate fluid-tight sealing.
Such a fluid-tight seal lasts long enough to permit the separation and collection of a required amount of plasma. Because cartridge 12 is discarded after one use, self-destruction of the pivot pin bearing due to wear from a few hours of continuous rotation of rotor 18 is of no consequence in blood filtration applications.
Although the pivot pin bearing design described in copending application Ser. No. 722,707, (now U.S. Pat. No. 4,675,106) is successful in its own right and works well for its intended purpose, the Viton seal this design uses is very expensive, and its components must be closely inspected for use in blood filtration applications. It would be highly desirable to provide a low-cost injection molded plastic pivot pin bearing structure which exhibits acceptable wear, is more tolerant of elastomer formulations for the seal ring, and is inexpensive and relatively easy to fabricate to the precise dimensional tolerances required in a disposable plasmapheresis filtration cartridge.

Pivot pin bearing/seal with loose eyelet especially suited for disposable continuous flow blood filtration system cartridges


This patent discloses methods of manufacturing rotors particularly adapted for use in hermetically sealed motor-compressor units of the type to be utilized for refrigeration applications. Previously known standard manufacturing steps are followed in producing a rotor having counterweights at one end thereof secured to the rotor by any suitable fastening means. Practice of the present invention results in rotors that include a shroud overlying the counterweights. In the manufacture of the shroud itself, I locate a centrally disposed region and define such region by piercing the shroud material along a major portion of its perimeter, but retain at least two tabs or ears which interconnect the centrally disposed portion of the shroud with the remainder of the shroud. The resulting shroud preferably has a centrally disposed portion which then may be separated from the remainder of the shroud by fracturing the interconnecting tabs in order to expose the rotor shaft.. Thereafter, the shaft may be pressed out of the rotor, and the central portion of the shroud retained. Subsequently, the central portion of the shroud is relocated on the remainder of the shroud, pressed into position, and refastened by any suitable means, such as, but not limited to, spot welds, silver solder, brazing, etc. The rotor having a reassembled shroud then is usable in a reassembled compressor.

The present invention relates generally to dynamoelectric machines, and, more particularly, to improved rotor structures in dynamoelectric machine structures which are hermetically sealed within an assembly such as a refrigeration compressor.
In refrigeration compressors of the hermetically sealed type, stators and rotors which comprise electric motor parts are mounted so as to operatively drive a shaft which is connected to a compressor mechanism. Such compressor mechanism may be of the reciprocating piston type as shown, for example, in Cheers U.S. Pat. No. 3,663,127 which issued May 16, 1972. On the other hand, such compressor units may be of the type known in the industry as rotary compressors. In many compressors, the shaft itself is hollow and such an arrangement is illustrated in the above-referenced Cheers U.S. Pat. No. 3,663,127. An axially extending hole in the shaft may be utilized for numerous different functions. Typically, for example, the hole may be utilized to provide a passage through which lubricating oil may pass and thence be circulated from one end of the shaft to another. This type of arrangement is illustrated and discussed in some detail in the above-referenced Cheers patent. As will be understood by persons skilled in the art, rotors used in these types of applications usually are provided with rivets or other fastening means which are utilized to secure counterbalance weights. The counterbalance weights then provide the function of counterbalancing unbalances in the rotor structure per se, and/or unbalances associated with masses that are attached to the rotor shaft. One such mass may, for example, be a crank shaft and one or more pistons (along with connecting structure therefor) which are attached to the crankshaft. Counterbalance weights and methods of attaching the same are illustrated and decribed in McCroskey et al U.S. Pat. No. 3,965,382 which issued June 22, 1976 (as well as in the above-referenced Cheers patent).
Prior to the present invention, others have suggested and presumably used in commercial practice, shrouds which were attached to the top of the rivets or other fastening means that were provided to hold balance weights in place on the rotor structure. These shrouds, known by others prior to the present invention, were intended to give support to exceptionally heavy counterweights on the rotor. In addition, the shrouds that were suggested by others would serve an additional desirable function of deflecting refrigerant gas in the area of the shroud. It apparently has been concluded that it would be desirable to prevent any high pressure gas within the compressor unit from being directed axially downwardly along the rotor shaft.
Carter U.S. Pat. No. 2,875,694 which issued Mar. 3, 1959 illustrates an end closure plate disposed above the end of a hollow rotor shaft. Even though Carter relates to an art generally nonanalogous to the hermetically sealed refrigerator compressor art, a review of the structure shown by Carter will be helpful to an understanding of the relationships of parts that have been described hereinabove. Still other patents in nonanalogous arts are broadly addressed to methods of attaching counterweights. One such patent, for example, is McClendon U.S. Pat. No. 2,993,386 which is related to the nonanalogous art of mounting balance weights to motor vehicle brake drums.
Other patents of which I am aware that generally illustrate hermetically sealed refrigeration compressor motor parts are Smith U.S. Pat. No. 2,089,626 of Aug. 10, 1937; Hurst et al U.S. Pat. No. 3,584,980 of June 15, 1971; Heitchue U.S. Pat. No. 3,616,384 which issued Oct. 19, 1971; Leffers et al U.S. Pat. No. 3,664,461 which issued May 23, 1972; and Mitch U.S. Pat. No. 4,091,638 which issued May 30, 1978.
Of the above patents, the 1937 patent of Smith illustrates generally the type of apparatus referred to hereinabove (including balance weights). The Hurst et al patent clearly illustrates a piston type compressor utilizing a rotor shaft having oil pumping passages therein; and the Heitchue patent illustrates a piston type compressor having a piston attached to the upper end of the rotor shaft. The Leffers et al patent, on the other hand, describes in some detail the lubricating arrangements for hermetically sealed compressor motor parts; while the Mitch patent is concerned with cooling of hermetically sealed compressor motor parts. The Mitch patent is also of interest at least to the extent that it illustrates a cap member denoted by the numeral 72 in the Mitch patent which extends above the drive shaft of the compressor and seals off the shaft which is provided with oil passages.
As indicated hereinabove, prior to the present invention others have suggested the use of shrouds that would both structurally reinforce rotor structures having exceptionally heavy counterweights as a part thereof, and that would deflect gas in the area of the end of the rotor. Work performed by others utilizing such arrangements identified new problems associated with such shroud usage. More specifically, it was found that for one reason or another it might, on occasion, be desirable to disassemble the motor parts of a given compressor wherein a shroud had been utilized.
The actual assembly of motor parts in a compressor usually involves press fitting a rotor body onto a shaft; and disassembly of such parts requires that the end of the shaft be accessible for tools and fixtures which are to be utilized to press the shaft back out of the rotor. However, when shrouds are provided at the end of the shaft, the shaft end becomes inaccessible. As a solution to this problem, others have suggested that the shroud be provided with a hole in the center thereof which would permit access to the end of the rotor shaft in the event that it was desired to press the shaft out of the rotor. This suggested solution however was not fully satisfactory for the reason that gasses within the compressor would then have access to the end of the shaft and the interior of the rotor through the centrally disposed opening in the shroud.
Still another suggestion or remedy for correcting the exposed shaft and shaft accessibility problems involved the suggestion of providing spring loaded closure plugs which would be snapped into a hole in the center of a rotor shroud. It has been thought, however, that such an arrangement would be unsatisfactory since the spring loaded plugs could contribute to vibration, and/or might in fact be dislodged during motor operation. To simplify the disclosure that is presented herein, and which was conceived against the background of all of the preceding description; it is now noted that the entire disclosures of all of the above cited references are incorporated herein by reference-with the exception of that art which has been specifically indicated to be directed to nonanalogous subject matter.
It should now be understood that it would be desirable to provide a rotor for a hermetically sealed compressor wherein the rotor includes a shroud disposed to cover the end of a shaft subsequently assembled with the rotor. More specifically, it would be desirable that such shroud be closed in the central portion thereof to prevent exposure of the end of the shaft to gases in that area. In addition, it would be desirable that the shroud be devised such that the rotor could be disassembled from the shaft by pressing against the end of the shaft under the shroud without destroying the usefulness of the rotor in a subsequently reassembled compressor. Moreover, it would be desirable to provide new and improved rotor constructions and methods of making the same whereby the rotor structure, including the shroud supplied therewith, would be completely reusable in a reassembled compressor environment with the shroud protecting the end of the shaft from gases being directed thereon and all without requiring the use of auxiliary caps or plugs.
Accordingly, it is an object of the present invention to provide new and improved rotor structures usable in a sealed compressor environment wherein a shroud on the end of the rotor will be effective to deflect gases from the end of the rotor shaft, and yet wherein such structure may be readily separated from a press fit shaft without destroying the rotor, shaft, or shroud; and yet wherein the rotor and shroud may be reassembled on the same shaft or a different shaft with the shroud structure performing the same desired deflection function in the subsequently reassembled environment.
Another object of the present invention is to provide (for use in a new and improved method of salvaging and re-using shrouded rotors in compressor assemblies) new and improved rotor assemblies.

Rotor assembly having shroud with replaceable knock-outs


There are provided a hard film-coated member excellent in wear resistance and adhesion, and a jig for molding. The hard film-coated member includes: a base material including an iron base alloy containing Cr; a first film layer formed with a film thickness of 1 to 10 μm on the surface of the base material; and a second film layer formed with a film thickness of 2 to 10 μm on the surface of the first film layer. The first film layer includes Cr1-a-bMaBb(CcN1-c), wherein M is one or more elements selected from W, V, Mo, Nb, Ti, and Al, and a, b, and c each denote the atomic ratio, and satisfy: 0≦a≦0.7; 0≦b≦0.15; 0≦c≦0.5; and 0.3≦1-a-b. The second film layer includes Nb1-d-e-fCrdAleLf(CgN1-g), wherein L is one or more elements selected from Si, Y, and B, and d, e, f, and g each denote the atomic ratio, and satisfy: 0.05≦1-d-e-f≦0.5; 0.05≦d≦0.5; 0.4≦e≦0.7; 0≦f≦0.15; and 0≦g≦0.5.

1. Field of the invention
The present invention relates to a hard film-coated member coated with a hard film on the surface thereof, and a jig for molding using the member.
2. Description of the Related Art
Conventionally, jigs for metal working such as dies have been improved in wear resistance and seizure resistance by a nitriding treatment. Further, in recent years, a study has been conducted on the improvement of the wear resistance and the seizure resistance by gas phase coating such as PVD in place of a nitriding treatment. For example, JP-A No. 2000-144376 discloses a hard film improved in wear resistance by the formation of a composite nitride containing two or more of Cr, Al, Ti, and V. Whereas, JP-A No. 2002-307128 and JP-A No. 2002-307129 disclose a coated jig for warm working excellent in wear resistance or seizure resistance, including a coated layer formed of one or more nitrides, carbides, and carbonitrides of Ti, V, Al, Cr, and Si formed therein, and, optionally, a sulfide layer including Ti and Cr, and the balance of Mo further formed thereon. Further, JP-A No. 2000-1768 discloses a hard film excellent in wear resistance and seizure resistance, including a surface layer containing MoS2 as a main component on a high hardness film; and an article with the film. Further, JP-A No. 2006-124818 discloses a hard film including (Xc, M1-c)(BaCbN1-a-b), where M is one or more of W and V, and X is one or more of elements of Groups 4A and 5A, Al, Si, Fe, Co, and Ni; and a formation method thereof.
However, the hard film including a composite nitride containing two or more of Cr, Al, Ti, and V described in JP-A No. 2000-144376 has high hardness, and is excellent in wear resistance, but is insufficient in seizure resistance. Thus, when plastic working of a metal is carried out under a high surface pressure, or in other cases, the hard film cannot withstand use in a severe environment. Whereas, the coated layer including one or more nitrides, carbides, and carbonitrides of Ti, V, Al, Cr, and Si disclosed in JP-A No. 2002-307129 also similarly has high hardness, but is inferior in seizure resistance.
Then, when the sulfide layer is formed as described in JP-A No. 2002-307128 or JP-A No. 2000-1768, the sulfide is soft, and it is excellent in sliding property (wear resistance) at the beginning of use, but wears with time in use. Thus, the wear resistance cannot be kept over a long period. Whereas, also for the hard film including (Xc, M1-c)(BaCbN1-a-b) described in JP-A No. 2006-124818, as with the case of the sulfide layer, the sliding property (wear resistance) is excellent at the beginning of use, but the wear resistance cannot be kept over a long period.
Further, when the coated layer including nitride, carbide, and carbonitride selected from one or more of Ti, V, Al, Cr, and Si of JP-A No. 2002-307128 or JP-A No. 2002-307129 is directly formed on a low-hardness iron type base material, unfavorably, peeling tends to occur (adhesion decreases) due to a difference in elasticity and plastic deformation behavior from the base material.

Hard film-coated member and jig for molding


A sensing system for detecting degradation of a machine fluid is disclosed. The sensing system may comprise a tag having electrical contacts. The tag may be configured to transmit a wireless signal when the electrical contacts are in electrical communication. The sensing system may further comprise a dissolvable element separating the electrical contacts and obstructing electrical communication between the electrical contacts. The dissolvable element may be configured to dissolve and allow electrical communication between the electrical contacts when an acid content of the machine fluid reaches a level indicative of the degradation of the machine fluid.

Many machines and equipment circulate fluids that perform various functions such as lubricating moving parts, transferring heat, separating moving parts, absorbing contaminants, and powering hydraulic motors and hydraulic cylinders. Such fluids may include engine oil, transmission fluid, hydraulic fluid, and coolant fluid. For instance, engine oil and transmission fluid may lubricate moving parts such as gears and pistons, while hydraulic fluid may power hydraulic cylinders, such as those used to raise and lower an implement of an earth-moving machine. However, as the machine operates and with extended hours of machine operation, such fluids may degrade due to oxidation, thermal breakdown, and/or contamination. For example, as an engine oil degrades, the acidity of the oil may increase, leading to an increase in the viscosity of the oil and eventual formation of sludge and varnish. When the acid content of the engine oil reaches a certain level, it may signify that the engine oil has reached its useable life and needs to be replaced with fresh oil.
The machine or equipment may also include one or more filters that collect contaminants such as particles and debris that have accumulated in the fluids to protect bearing surfaces, engine liners, and/or other engine parts from wear. Although such filters may extend the period of service of the fluid, they may not be equipped to detect when the fluid has reached its useable life and needs to be replaced.
U.S. Pat. No. 7,043,402 discloses a sensing system for real-time monitoring of the quality of engine lubricating oil. In particular, the sensing system includes at least two electrodes installed on a port of a lubricating oil reservoir that monitor the quality of the lubricating oil based on impedance measurements. Other sensing systems for monitoring machine fluid quality may be complex and/or expensive to implement.
Thus, there is a need for improved sensing systems for detecting degradation of machine fluids.

Sensing system for detecting machine fluid degradation


Reagents to cause swelling of coarsely ground vulcanized rubber, and a method of using the reagents is disclosed. Reagents which cause rubber to swell but which do not attack or react with rubber include various hydrocarbons, ketones and lactones. Specifically useful are benzene, cyclohexanone, cyclohexane, toluene, xylene, hexane, heptane, acetone, gasoline, paramethadione, ethyl acetate, methyl ethyl ketone and amyl acetate. It is taught that specific reagents work most effectively with specific types of rubbers, and that mixtures of reagents, preferably reagents having the same polarity, may be used. The reagent of the present invention is mixed with the coarsely ground rubber powder for about five minutes or more, causing the rubber particles to approximately double in size. Preferably, the reagent is substantially fully absorbed by the rubber. The swollen rubber is then suitable for further processing, namely, grinding into a superfine powder. The soaking and processing of the rubber is conducted in an enclosed system to that the reagent can be recovered and recycled. A crystalloid salt, such as zinc carbonate may be added to the mixture to assist the grinding process.

The present invention relates to reagents for causing rubber to swell in order to facilitate recycling of rubber.
It is estimated that 15,000,000 tons or more of vulcanized rubber products are discarded annually. Approximately half this amount is in the form of rubber tiresxe2x80x94upwards of 700 million tires are discarded per year worldwide. It is estimated that there are as many as three billion waste tires in the U.S. alone. The handling and disposal of this large volume of rubber products is a significant environmental problem, and the desirability of recycling waste rubber is evident. Unfortunately, the very properties which make vulcanized rubber so useful make it extremely difficult to recycle. Specifically, rubber does not melt, age or decompose and is designed to be used in extreme environmental conditions. Rubber used in tires is highly elastic and tenacious in a temperature range of xe2x88x9250xc2x0-+150xc2x0 C., and is highly resistant to attack by most common chemical substances. While significant research has been devoted to investigating techniques for recycling rubber, to date only a small percentage of waste rubber is recycled.
One avenue of investigation has been directed to forming rubber powders from waste rubber by grinding the rubber. The rubber powders are then added to a raw rubber mix to form new rubber. This technique has important potential cost savings because the rubber powder reduces the energy and processing required to make new rubber. Currently, rubber powder is used in making many rubber products, including tires, hoses, rubber bands, etc. In addition, rubber powders can be added to other products, such as building materials, to improve their properties.
The amount of rubber powder that can be added to a raw rubber mix during rubber production is highly dependant on the size and shape of the rubber particles which comprise the powder. Specifically, it is known that superfine rubber particles (particles having a diameter of about 200 xcexcm or less) may be added in significantly higher percentages than larger particles. However, traditional grinding techniques produce rubber particles having a diameter in excess of 600 xcexcm. To date, addition of rubber powder having particles in excess of 600 xcexcm has not been accepted by producers of rubber products, because rubber made with large particles has poor properties. Rubber powder consisting of particles in the range of 200-400 xcexcm may be added in an amount of up to 10% without adversely affecting the quality of the rubber produced.
Finer grain rubber particles may be produced by grinding the rubber at extremely low temperatures (for example, using liquid nitrogen) such that the rubber loses its elasticity. However, due to the energy required to cool the rubber to a sufficiently low temperature, it is uneconomically expensive to form rubber powder in this way.
The inventor of the present invention has previously disclosed a technique for grinding rubber which employs a reagent to cause the rubber to swell. The swollen rubber is more rigid and, therefore, more easily ground into fine particles. The prior disclosure teaches soaking coarsely ground rubber in a non-polar reagent for 5-30 seconds, and then performing further grinding of the resulting swollen powder to achieve a rubber powder with particles having a mean diameter as low as 10 xcexcm. This disclosure further teaches that such a rubber powder can be mixed with raw rubber in excess of 40% without impairing the physical properties of the rubber. The prior disclosure suggests the use of toluene, xylene, carbon tetrachloride, carbon trichloride, acetone, ethyl alcohol or mixtures thereof. Toluene and xylene were thought, at the time of the prior disclosure, to be particularly good. However, at the time of the prior disclosure the inventor had not arrived at an optimal reagent system for use in his invention, nor had he optimized the soaking process, nor had he investigated the optimal reagents to use with various types of vulcanized rubber.
Accordingly, one object of the present invention is to provide an optimized reagent system for soaking rubber particles to cause them to swell.
Another object of the present invention is to provide a method for soaking rubber particles in a reagent to cause them to swell.
Yet another object of the present invention is to provide reagent mixtures for causing rubber to swell which are optimized for different types of vulcanized rubber.
The foregoing objects of the invention, and others that will be apparent to those skilled in the art, are realized in the present method for causing rubber particles to swell. In its basic aspect, the present invention comprises a method for causing rubber particles to swell, comprising the steps of mixing coarsely ground rubber particles with a swelling reagent comprising an organic solvent, soaking the mixture for at least five minutes, or until the rubber particles have increased in size by at least 100%, and, if necessary, removing any excess swelling reagent from said mixture. At least two parts of the swelling reagent is used for each part of rubber powder. Preferably, the weight ratio of reagent to rubber is between 2.5-3.5 to 1, so that substantially all of the reagent is absorbed by the rubber. Preferably, the swelling reagent comprises a hydrocarbon, a ketone or a lactone, more specifically a member of the group consisting of benzene, cyclohexanone, cyclohexane, toluene, xylene, hexane, heptane, acetone, gasoline, paramethadione, ethyl acetate and amyl acetate. Most preferred are benzene, cyclohexanone or cyclohexane, and may comprise a mixture of reagents, preferably reagents having the same polarity.
For natural rubber, isoprene rubber, butadiene styrene rubber or 3-polybutadiene rubber, benzene is preferred; for chloroprene rubber or acrylonitrile rubber, cyclohexanone is preferred; and for butyl rubber or ethylene propylene rubber cyclohexane is preferred. When processing different types of rubbers, a mixture comprising at least two of these compounds is preferred.
In order to facilitate removal and recovery of the reagent from the mixture after grinding, the method is performed in an enclosed system and the mixture is heated while applying a vacuum to the enclosed system.
According to the present invention, a reagent is mixed with coarsely ground rubber particles in order to cause the rubber particles to swell. The swollen rubber particles are substantially less elastic than unswollen rubber and can be ground into a superfine powder which, is suitable for recycling, as by incorporating the superfine powder into new rubber being produced.
The present invention starts with coarsely ground rubber particles, i.e., particles having a mean diameter in the range of about 500 xcexcm to 1,500 xcexcm. Methods of grinding rubber to form rubber particles in this size range are well known in the art and need not be described in detail. For example, a conventional high speed shearing roller crusher may be used. While practical considerations make it desirable to start with particles in the range stated, there is no reason why the starting particles cannot fall outside of this range.
The coarsely ground particles are placed into a soaking vessel which is, preferably, part of an enclosed system which is configured to automate the entire process. As described in greater detail below, the system is enclosed to facilitate reagent recovery.
A swelling reagent is then mixed with the coarsely ground rubber particles in the soaking vessel. The swelling reagents that have been found to be effective are various organic solvents, including hydrocarbons, ketone and lactones. Specifically, benzene, cyclohexanone, cyclohexane, toluene, xylene, hexane, heptane, acetone, gasoline, paramethadione, ethyl acetate, methyl ethyl ketone and amyl acetate have been found to be effective. The reagent that is selected should be a compound which causes the rubber particles to swell, but which does not attack or react chemically with the rubber. Preferably, the reagent used with a particular type of rubber should have the same polarity as the rubber. Particularly preferred reagents are benzene, cyclohexanone, cyclohexane, with benzene being preferred for use with comprise natural rubber, isoprene rubber, butadiene styrene rubber or 3-polybutadiene rubber, cyclohexanone being preferred for use with chloroprene rubber or acrylonitrile rubber, and cyclohexane being preferred with butyl rubber or ethylene propylene rubber. Two or all three of these reagents, or other reagents, may be mixed in order to process rubber mixtures of various types. When mixing reagents it is preferred to use combine reagents of the same polarity. The coarse rubber particles are soaked in the swelling reagent(s) for a sufficiently long time to cause the particles to increase in size by at least 100%. The exact amount of time required to do this will vary according to the size of the particles, the type(s) of rubber, and the nature of the reagents. However, nornmally the particles should be allowed to soak for at least five minutes. The mixture of rubber particles and reagent may be stirred during this time to ensure that all of the rubber particles come in full contact with the reagent. Preferably, at least twice the volume of the reagent is used as rubber, i.e., at least two parts by weight of reagent are used for one part of rubber particles. In the preferred embodiment of the present invention, the quantity of regent that is used is an amount which is small enough to be fully absorbed by the rubber particles without excess while causing the rubber particles to swell in size by 100%. It is preferably that substantially all of the reagent be absorbed so that it is not necessary to filter or otherwise take steps to separate excess reagent from the swollen rubber particles prior to further processing, e.g., grinding. Normally, the amount of solvent will fall in the range of 2.5 to 3.5 times the amount of rubber, by weight.
The selection and handling of the reagents used in connection with the present invention should take in account health and safety considerations. Whenever possible, preference should given to reagents with the least toxicity, lowest flammability and best handling characteristics. Also, whenever possible, a single reagent, rather than a reagent mixture, should be used. Use of a single reagent makes it easier to collect, condense and recycle the reagent. However, multiple reagents, i.e., a reagent mixture, may be used where necessary to reduce toxicity or when special types of rubbers are included in the rubber mix being recycled.
In the preferred embodiment, after the step of soaking the rubber particles has been completed there is substantially no excess reagent, i.e., substantially all of the reagent has been absorbed. In a less preferred embodiment, any unabsorbed reagent is drained or filtered from the mixture and recovered, preferably for recycling. As noted the step of soaking is conducted in an vessel which is part of an enclosed system, so that any vapors emanating from the mixture may be captured for recovery and recycling. As noted the purpose of soaking the rubber particles is to facilitate further processing, i.e., grinding of the swollen particles to create a superfine rubber powder. According to the present invention, further processing of the particles occurs within the enclosed system so as to prevent the escape of reagent vapors, and thereby permit the recovery and recycling of the reagents. After the rubber particles have been processed, i.e., ground to a superfine powder, the processed rubber is heated causing the absorbed reagent to evaporate. Again, heating of the processed rubber is performed within the same enclosed system so that the reagent can be recovered and recycled after it evaporates. A slight vacuum is applied to the system to facilitate the recovery process.
After the reagent is absorbed by the rubber, a material, preferably a crystalloid salt may be added to enhance grinding. Particularly preferred is zinc carbonate because it is compatible with subsequent rubber processing. In one embodiment of the present invention, up to 5% by weight of zinc carbonate is added.

Reagents for swelling rubber and method of using

Nanjing Weilong Industrial Co. Ltd. Jiang su Tong Xin Plaza, No. 198, Ji Qing Road


‘NCCO1’ is a new cultivar of smokebush is disclosed, characterized by a compact habit, dark purple foliage, and large, purple inflorescences. The new variety is a Cotinus coggygria, typically produced as an outdoor ornamental plant.

The present invention comprises a new and distinct smokebush cultivar hereinafter referred to by the cultivar name 'NCCO1'. This new smokebush was developed through a breeding program at Mills River, N.C. 'NCCO1' was selected from a population of seedlings grown from an open-pollinated, unnamed, Cotinus coggygria. The first asexual propagation of 'NCCO1' was carried out in July 2009 by rooting stem cuttings at a research nursery in Mills River, N.C. and has been asexually reproduced repeatedly by vegetative cuttings and tissue culture over a 8 year period. 'NCCO1' roots from softwood cuttings treated with a basal dip of 6,000-8,000 ppm indole butyric acid (potassium salt) in water. 'NCCO1' has been found to retain its distinctive characteristics through successive asexual propagations.


A method for providing a model of surroundings for a vehicle includes providing a model of the surroundings based on sensor measurements by sensors of the vehicle, wherein the model of the surroundings provides information relating to an occupation of the surroundings by one or more objects, including information regarding a type of object in the surroundings of the vehicle. The method includes determining a region of the surroundings for which no information relating to occupation by objects is provided by the model of the surroundings, wherein the region is within a distance limit for which the sensors can provide sensor measurements relating to the occupation by objects, and checking whether a phantom object is to be added to the model of the surroundings in the region based on the type of object and predefined regulations, wherein the phantom object is an object which was not determined on the basis of sensor measurements. In the event the phantom object is determined to be added, the method further includes determining the occupation by the phantom object in the region of the surroundings, and generating an extended model of the surroundings by adding information relating to the occupation by the phantom object to the model of the surroundings, and then providing the extended model of the surroundings.

The invention relates to a method for providing a model of the surroundings for a vehicle, to a corresponding computer program and a computing apparatus and to a vehicle for the same purpose.
In future, motor vehicles will have an abundance of driver assistance systems which warn the driver of collisions, for example, and possibly also attempt to avoid collisions by means of interventions. Examples of such driver assistance systems are an emergency brake assistant, a lane-keeping assistant, a blind spot assistant, a parking assistant and a so-called automatic cruise control (ACC) assistant, in particular for freeway journeys. In addition, highly automated driving, that is to say the movement of a vehicle without (or substantially without) human intervention, also presupposes knowledge of the surroundings of the vehicle. In order to provide these functions, knowledge of the surroundings of the vehicle is decisive for driver assistance systems. For this purpose, the surroundings are scanned or recorded using one or more sensors such as radar, lidar, camera, ultrasonic sensors or similar sensors known from the prior art. The occupation of the surroundings by objects is then detected with the aid of the sensor measurements with the aid of signal processing methods which are likewise known in the prior art. The occupation indicates that the surroundings cannot be traversed by the vehicle in a particular section and therefore indicates the position of the object. The type of objects is additionally detected, that is to say whether the objects are pedestrians, vehicles, road boundaries, etc. The detected occupation and the types of objects are used to create a model of the surroundings which provides information relating to the occupation of the surroundings by objects, that is to say, in particular, those sections of the surroundings which are occupied by objects, and the type of objects.
One concept for highly automated driving on freeways on the basis of a model of the surroundings is presented, for example, in "A legal safety concept for highly automated driving on highways" by Benoit Vanholme, et al., Intelligent Vehicles Symposium (IV), 2011 IEEE, Jun. 5-9, 2011, pages 563-570. Such a concept is likewise presented in the dissertation "Highly Automated Driving on Highways based on Legal Safety", University of Evry-Val-d'Esssonne dated Jun. 18, 2012 by Benoit Vanholme. This publication also presents the concept of phantom objects. In this publication, a phantom object is a fictitious object which is assumed at a distance for which no occupation can be created with the aid of the sensors of the vehicle because the measurement range of the sensors has been exceeded.
In addition, when creating a model of the surroundings, the problem exists that no objects can be detected in regions of the surroundings which are concealed by objects in so far as the objects prevent sensor measurements in these regions. The model of the surroundings does not provide any information relating to the occupation by objects for these regions. For example, a stopped bus may conceal a pedestrian in front of the bus. Consequently, no information relating to this pedestrian would be present in the model of the surroundings. If the pedestrian then emerges behind the bus, his occupation will suddenly appear in the model of the surroundings and will cause a possibly severe and sudden reaction by the driver assistance systems. There is also an increased risk of an accident.
An object of the invention is to enable driver assistance systems based on models of the surroundings to take into account possible concealed objects.
In one aspect, a method for providing a model of the surroundings for a vehicle comprises: providing a model of the surroundings which was obtained on the basis of sensor measurements by sensors of the vehicle, the model of the surroundings providing information relating to the occupation of the surroundings by objects and, in particular, the type of objects in the surroundings of the vehicle; determining a region of the surroundings for which no information relating to occupation by objects is provided by the model of the surroundings, the region being within a distance limit for which the model of the surroundings could provide information relating to the occupation by objects on the basis of sensor measurements; checking whether a phantom object needs to be added to the model of the surroundings in the region, in particular using a predefined regulation; if a phantom object needs to be added: determining the occupation by the phantom object in the region of the surroundings, and generating an extended model of the surroundings by adding information relating to the occupation by the phantom object to the model of the surroundings; providing the extended model of the surroundings. The type of object may also relate only to whether the object is moving or is stationary.
A virtual object, a phantom object, is therefore assumed in the model of the surroundings for the concealed region of the surroundings. Phantom objects are, in particular, assumptions of concealed other road users and therefore a safety measure. This assumption compensates for the "blindness" of the sensor systems for concealed regions. Driver assistance systems, in particular systems for highly automated driving, can therefore take the object into account in their planning and function. The precautionary measure of the driver assistance systems is therefore moved to the model of the surroundings by the respective driver assistance system itself in one implementation. The safety measure in the model of the surroundings would therefore have an effect on all driver assistance systems which use the model of the surroundings. In addition, phantom objects can also be added by a driver assistance system or by a component between the creation of the surroundings and the driver assistance system.
As a result of the inclusion of the phantom objects, driver assistance systems can adapt their function in the best possible way to the traffic situation (for example can limit the speed) and can therefore avoid possible accidents or drastically reduce damage. In one typical implementation, a phantom object can be distinguished from a real object (detected using sensor measurements) in the model of the surroundings. The phantom object is therefore indicated as such. Driver assistance systems can now include phantom objects differently than real objects in their function, in particular journey planning or trajectory planning and selection, and therefore do not react to phantom objects to the same extent as they do for real objects. For example, a driver assistance system would not plan any delay in the journey planning for a relatively slow phantom object (even though it would do so for a relatively slow real object) but would nevertheless plan, in the journey planning (for example for future travel trajectories or speeds), that an accident can be avoided or mitigated if it subsequently emerges, on the basis of sensor measurements, that a real object is at the occupation of the phantom object. In an alternative implementation, a probability for its actual existence is assigned to each object in the model of the surroundings. This probability can generally be set lower for phantom objects than for objects which have been detected using sensor measurements.
When checking whether a phantom object can be assumed in a concealed region, it is advantageously assumed that the phantom objects, that is to say pedestrians or cyclists, for example, comply with the traffic rules or at least behave in a predictable manner (and in the process do not comply with the traffic rules). It is assumed, for example, that a pedestrian is on a pedestrian crossing which is concealed by a vehicle. At the same time, a phantom object need not be assumed for each concealed region. For example, a pedestrian is not automatically assumed as a phantom object behind a freeway pillar on a freeway.
In one development, the checking operation comprises the determination of whether an object in the surroundings prevents sensor measurements by sensors of the vehicle in the region at least in such a manner that no information can be provided by the model of the surroundings for this region. The region is therefore concealed by the object for sensor measurements and the object is a concealing object.
In one development, the determination of the occupation by the phantom object in the region of the surroundings comprises: determining the type of preventing object and determining an assumption with respect to the occupation by the phantom object and an assumption with respect to the type of phantom object with the aid of a pre-stored assignment. The assignment may specify rules or regulations regarding where the phantom object should be placed and where its occupation is. The occupation can be oriented to the model of the surroundings and its limits and to the preventing objects. The computing means are set up to use these rules or regulations in order to determine the occupation by the phantom object.
The assignment may specify a rule for the occupation by the phantom object, the rule spatially relating the occupation to the region and/or the object, in particular. A separate rule can be specified for each type of concealing object.
The type of preventing object may also relate to the difference between a stationary object and a moving preventing object. Therefore, only two types may exist in some implementations: a stationary object and a moving preventing object.
In one implementation, the checking operation also takes into account the type of preventing object, in particular using a predetermined list. A phantom object can therefore be assumed for some preventing objects and cannot be assumed for others. If the preventing object is a bus, a phantom object in front of the bus can be assumed. If the preventing object is a bush on a traffic island, for example, no phantom object needs to be assumed behind this bush.
The method can also comprise: determining the type of phantom object to be added and, in particular, its occupation of the surroundings on the basis of the type of preventing object, in particular using a predetermined assignment which comprises the list, in particular. If a bus is the preventing object, for example, a pedestrian can be assumed as the type of phantom object in front of the bus but not a motorcyclist. The type of phantom object can depend on a predetermined assignment. The assignment links the type of object to the type of phantom object. The type of object alone can be understood as meaning a list indicating the types of preventing objects for which phantom objects are assumed. Furthermore, the occupation of the surroundings by the phantom object, that is to say its position, is determined, in particular. The occupation can be determined using the distance limit, with the result that the occupation is positioned precisely on the far side of the limit for which sensor measurements are still available, in other words: precisely within the region or at the boundary of the region (for example 1 m or 0.5 m away from the boundary of the region). The occupation by the phantom object can be specified by means of a pre-stored assignment.
Furthermore, the type of phantom object to be added can be determined on the basis of the type of environment and/or the time of day. For example, in the environment of a school, a (playing) child can be assumed as a phantom object (which moves onto the road from the concealed region) behind a parked and preventing vehicle during the day. Conversely, a pedestrian is not assumed behind a vehicle on a country road at night.
In one preferred development, the checking operation also takes into account whether the traffic rules or predefined further rules applicable in the region provide for other road users to be in the region. The checking aspect with respect to the traffic rules can be carried out on the basis of detected road markings (for example part of a zebra crossing or a road marking and its assumed continuation). The checking aspect with respect to the further rules can be carried out on the basis of predefined regulations. In order to avoid providing too many phantom objects in the extended model of the surroundings, phantom objects are assumed only where they can also be expected in all probability, that is to say only in a concealed region in which the traffic rules or the predefined further rules simultaneously provide for other road users. For example, pedestrians can be expected at a pedestrian crossing concealed by a stationary vehicle or in front of a stationary bus or an automobile can be expected in front of a truck to be overtaken. In this case, other road users cannot only be assumed where the traffic rules provide for this, but also where they are typically situated, that is to say in front of a stationary bus without a pedestrian crossing, for example. In order to ensure a useful method of operation of driver assistance systems, all possible phantom objects should not be included irrespective of traffic rules or other rules, that is to say no collapsing bridges or a group of drivers traveling in the wrong direction on the freeway. The methods of operation of driver assistance systems would otherwise be greatly jeopardized. When selecting the further rules (which go beyond the traffic rules), a balance between defensiveness and assertiveness is advantageously found. Another rule is, for example, that, although the other road user does not comply with the traffic rules, he nevertheless behaves in a predictable manner and is subjectively defensive.
In one development, the method also comprises: if a phantom object needs to be added: determining the direction of movement, a plurality of possible future trajectories of the phantom object and their associated occurrence probabilities and/or the behavior of the phantom object to be added; and supplementing the extended model of the surroundings with information relating to the direction of movement. The direction of movement can be determined using the type of preventing object and the arrangement of the objects on the road. The possible future trajectories and their occurrence probabilities and the behavior can likewise be determined using the type of preventing object and the arrangement of the objects on the road. In this case, it is possible to resort to pre-stored scenarios (typical constellations of types and arrangements). It can therefore be assumed, for example, that a pedestrian concealed by a stopped bus crosses the road. A "worst-case" assumption can always be made for the direction of movement, that is to say the direction of movement is on a collision course with the direction of travel of the vehicle. A driver assistance system would then be set up (also when taking a plurality of trajectories into account) to minimize the risk of collision.
In another aspect, a computer program causes a computer to carry out one of the methods above during the execution of the computer program.
In another aspect, a computing apparatus comprises electronic computing means which are set up to carry out one of the methods above. The electronic computing means may be a computer, a microcontroller or dedicated circuits. The computing apparatus may be caused to carry out the method by a computer program.
In yet another aspect, a motor vehicle comprises sensors for detecting objects in the surroundings of the vehicle and above computing means.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawing.

Bayerische Motoren Werke Aktiengesellschaft


A downhole pressure fluctuating tool having an improved acoustical circuit using a fluid oscillator to generate out-of-phase pressure fluctuations in two output legs, one connected to an acoustical compliance inside the tool and the other connected to an acoustical compliance exterior of the tool in a cavity partially formed by the wall of the well. An acoustical inertance with a pressure node at its midregion connects the two acoustical compliances, and said midregion communicates with the annulus between the body of the tool and the wall of the well to discharge fluid from the body at the pressure node to minimize acoustical losses in the annulus.

1. Field of the Invention
This invention relates in general to downhole tools used in boreholes and wells, and in particular to tools using fluid-driven acoustical oscillators and circuits to generate pressure fluctuations of large amplitude.
2. Background Information
In U.S. Pat. No. 3,405,770, Drilling Method and Apparatus Employing Pressure Variations in a Drilling Fluid, Oct. 15, 1968, are disclosed improved means for drilling boreholes in the earth by effecting elastic vibrations in the drilling fluid surrounding a rotating drill bit. In the preferred embodiment the fluid pressure at the borehole bottom is cyclically decreased, while simultaneously jet velocity and bit load are cyclically increased through the use of a bistable fluid oscillator, a coupler and resonators which cooperate to generate large fluid pressure fluctuations at the borehole bottom while minimizing acoustical energy transfer upward through the drilling fluid. The output of each of the two legs of the oscillator is fed into a cavity around the bit, after the phase of one output leg is inverted. Acoustical filters in the form of Helmholtz resonators C and D are connected respectively with the fluid passage or axial bore 121 with apertures 119 inside the tool leading to the bit and with the annulus with apertures 131 to minimize pressure losses and enhance efficiency.
Another apparatus and method used to isolate the out-of-phase pressure fluctuations of the output legs of a bistable fluidic oscillator are disclosed in U.S. Pat. No. 3,441,094, Drilling Methods and Apparatus Employing Out-Of-Phase Pressure Variations in a Drilling Fluid, Apr. 29, 1969.
Well stimulation apparatus and methods using the same general approach are disclosed in U.S. Pat. No. 3,520,362, Well Stimulation Method, July 14, 1970, in U.S. Pat. No. 3,842,907, Acoustic Methods for Fracturing Selected Zones in a Well Bore, Oct. 22, 1974, and in U.S. Pat. No. 3,850,135, Acoustical Vibration Generation Control Apparatus, Nov. 26, 1974.
A logging method which utilizes similar apparatus is disclosed in U.S. Pat. No. 3,860,902, Logging Method and system, Jan. 14, 1975, and a system for detecting the position of an acoustic generator in a borehole is disclosed in U.S. Pat. No. 3,876,016, Method and System for Determining the Position of an Acoustic Generator in a Borehole, Apr. 8, 1975.
Field experience and laboratory studies have been used to demonstrate the effectiveness of the above apparatus and methods for generating large pressure fluctuations useful in drilling, well treatment and logging. In the demonstrations a fluidic oscillator was used to alternately direct fluid between an exterior cavity and an interior cavity inside the too, with appropriate acoustical annulus filter means located one-quarter wavelength above, or above and below, the exterior cavity to minimize power dissipation in the annulus. The version of the tool shown in U.S. Pat. No. 3,520,362 is being used with successful results for well stimulation in a cased hole.


A level shift circuit includes: an electrothermal converter converting a first electric signal with a first reference potential as a reference to heat; a thermoelectric converter converting the heat from the electrothermal converter to a second electric signal with a second reference potential which is different from the first reference potential as a reference; and an insulating region electrically insulating the electrothermal converter from the thermoelectric converter.

Field
The present invention relates to a level shift circuit and a drive circuit.
Background
Level shift circuits for shifting the level of a drive signal from a low-potential side to a high-potential side are used to drive a semiconductor switching device on the high-potential side in drive circuits such as inverter apparatuses. Generally, HVICs (High Voltage Integrated Circuits), photocouplers, micro-transformers or the like are used as such level shift circuits (for example, see Patent Literature 1: JP 2003-115752 A).
An HVIC is constructed of PN junction isolation and electrically transmits a signal using a semiconductor device such as a MOSFET. A photocoupler is constructed of a light-emitting device such as a light-emitting diode and a light-receiving device such as a phototransistor, and transmits an electric signal by converting it to light. A micro-transformer is constructed of a coil and transmits an electric signal by converting it to magnetism.
However, with the HVIC, since the high-potential side is not electrically insulated from the low-potential side, noise on the high-potential side may transmit to the low-potential side. Since the photocoupler has a 2-chip configuration including the light-emitting device and the light-receiving device, it is difficult to miniaturize the photocoupler. The micro-transformer is also constructed of a plurality of chips just like the photocoupler, and so the micro-transformer is not only difficult to miniaturize but also more expensive than the HVIC and photocoupler.


A method for fabricating an integrated circuit having at least one integrated circuit component fabricated in a silicon substrate and a second device that is to be fabricated on a silicon oxide layer that covers the integrated circuit component. The integrated circuit component has a terminal that is to be connected a corresponding terminal on the second device. The second device includes an electrode structure in contact with a dielectric component that includes a layer of ferroelectric material. In the method of the present invention, a boundary layer comprising non-conducting polysilicon is deposited over the silicon oxide layer. The electrode structure is then fabricated by depositing one or more layers over the boundary layer. The ferroelectric layer is then deposited over the electrode structure and etched to provide the dielectric component. The boundary layer is then removed utilizing an etchant that etches silicon oxide much slower than polysilicon.

Ferroelectric capacitors or capacitor-like structures are of increasing interest in a number of integrated circuit applications. For example, as the feature size of DRAM memory cells is decreased in attempts to increase the density of DRAM based memories, the physical dimensions of the capacitors used to store the charge representing the data are also decreased. Since there is a minimum capacitance below which the DRAM cell will not operated satisfactorily, either a multilayer capacitor structure or a capacitor structure having an increased dielectric constant is needed. The former solution would substantially increase the cost of the memories; hence, there has been significant interest in utilizing capacitors with increased dielectric constants. Ferroelectric based capacitors based on lead zirconate titanate (PZT) that has been doped to be paraelectric at the operating temperature of the DRAMs have dielectric constants greater than 100. Hence, PZT-based capacitors are attractive candidates for replacing the conventional capacitors currently used in DRAMs.
Non-volatile memories based on PZT dielectric capacitors in which the dielectric is doped to be a ferroelectric at the operating temperature of the device have also attracted considerable interest because of the retention of the data in the absence of power. In addition, non-volatile memories based on a ferroelectric field effect transistor may also be used. Such a transistor structure is described in U.S. Pat. No. 5,070,385. This type of transistor may be viewed as a ferroelectric capacitor in which the top electrode is replaced by a semi-conductor layer having two contacts constructed thereon.
All of these memory cells require the construction of a ferroelectric capacitor adjacent to, or over, a CMOS transistor. In practice, the CMOS transistors are, constructed on a conventional silicon substrate and then covered with a silicon dioxide layer. The ferroelectric capacitor structures are then constructed on the SiO.sub.2 layer. The ferroelectric capacitor construction requires that a multi-layer structure constructed over the SiO.sub.2 layer be etched back to the SiO.sub.2 layer in selected regions. The multi-layer structure includes layers of platinum and PZT based compounds. The preferred etchant is a dry plasma etch, since such etching systems do not undercut the electrodes of the ferroelectric capacitor.
To etch the ferroelectric oxides of interest, a combination of fluorine and chlorine must be used in the plasma. Such plasma etchants etch SiO.sub.2 much faster than PZT compounds. Hence, any irregularities in the multi-layered structure will be transferred to the underlying SiO.sub.2. Furthermore, these irregularities will be magnified in the process because of the faster etch rates in SiO.sub.2. Such irregularities in the SiO.sub.2 layer cause problems when subsequent metal layers are applied to connect the various components.
Broadly, it is the object of the present invention to provide, an improved method for constructing a device having a ferroelectric layer that must be etched.
It is a further object of the present invention to provide a method for constructing a ferroelectric capacitor that allows the above described multi-layer stack to be etched leaving a flat SiO.sub.2 layer in the etched regions.
It is a still further object of the present invention to provide a method for constructing a ferroelectric capacitor that allows the multi-layer stack to be etched using a dry plasma etch.
These and other objects of the present invention will become apparent to those skilled in the art from the following detailed description of the invention and the accompanying drawings.

Method for constructing ferroelectric capacitor-like structures on silicon dioxide surfaces


A pulse signal delay device provides a fixed gate delay time in a digital integrated circuit (such as a CMOS circuit) independently of changes in a power supply voltage or environmental temperature. The device includes a series connection of delay units each having a minimum unit delay time and a circuit for continuously measuring the delay time of each delay unit, wherein a desired delay time is multiplied by the reciprocal of the delay time of each delay unit, and the number of stages of the delay units required for a predetermined delay time is automatically selected on the basis of the multiplication result, thus achieving a stabilized delay time.

1. Field of the Invention
The present invention relates to a delay device capable of managing the delay time thereof which can not be accurately defined otherwise, and more particularly to a delay device for delaying a pulse signal using the gate delay in an integrated circuit. The present invention also relates to a phase detector for a pulse signal and a clock generator using the above delay device.
2. Description of the Prior Art
In digital circuit design, frequently, a digital signal such as a pulse signal is delayed by a minute time period in such an arrangement of multi-stage connection of non-inverter TTL (Transistor Transistor Logic) gates having a relatively stabilized delay characteristic.
In JP-A-58-220588 (Reference No. 1), the above arrangement is applied to the clock generator for a time base corrector. In the time base corrector, it is important to provide a high phase accuracy of a generated clock with respect to an input video signal. In view of this, in the above clock generator, the generated clock is applied to a pulse delay device in multi-stage connection of non-inverter gates to prepare several kinds of clocks having different phases; the clock having the most coincident phase with the input video signal is selected among these clocks to prepare the clock with high phase accuracy.
If such a circuit arrangement is designed discretely using TTL devices, unevenness of the delay time thus generated is negligibly small. On the other hand, if this circuit is designed in an integrated circuit comprising CMOS's, the unevenness is noticeably large; this is very problematic.
Most of the gate arrays or standard cells in the latest digital integrated circuits are designed using CMOS's. However, CMOS has a defect that its gate delay characteristic is greatly influenced by a power supply voltage, environmental temperature, or electrical load. It has been generally believed that it is impossible to take a constant delay time using gate delay in the digital integrated circuit.
Meanwhile, disclosed in the proceedings (Reference No. 2) for the 1989 national conference of the institute of television engineers of Japan is a method of positively using the changing characteristic of a power supply voltage versus a gate delay time to provide a circuit for controlling the power supply voltage, thereby controlling the delay time so that it is maintained constant. However, in the case of an application of an integrated circuit, it is very difficult to control the power supply voltage within the integrated circuit.
The most common technique of detecting the phase of a pulse signal was to use a charge pumping circuit (to change a phase difference into a voltage) in an analog circuit design. However, to implement it in a digital integrated circuit was difficult for the above reason.
Further, in a clock generator used to generate e.g. a color subcarrier in a
system, it is difficult in terms of the synchronization accuracy of the clock to phase-modulate a horizontal synchronization signal to directly generate the color subcarrier. In view of this, it was proposed in JP-A-54-44431 (Reference No. 3) to generate the color subcarrier using a technique such as digital phase modulation.

Pulse signal delay device, and pulse signal phase detector and clock generator using the device

Matsushita Electric Industrial Co., Ltd.


An endless track conveyor apparatus having steps (1, 2) is driven by a drive chain (6) circulating along an endless travelling track (A, B-M, N, A) made up of an ascending section, a descending section, and U-turn sections connecting these ascending and descending sections. The endless track conveyor apparatus includes a driven medium having a number of piled-up slats (50), each of which is swingably supported on a conveyor frame. The driven medium engages with teeth provided on either the upper or the lower side of a chain link of the drive chain (6) provided at the ascending section (C-D) of the travelling track. The passive medium transmits the drive power of the drive chain (6) to the conveyor frame. Therefore, the endless track conveyor apparatus travels along the travelling track. On the other hand, at the descending section (J-K) of the travelling track, the load acting on the conveyor apparatus is converted into rotational motion. This rotational force is then reversed by a reversal transmission mechanism (8, 90-92, 107, 108) to transmit this rotational force to a rotational axis (105) which drives the drive chain (6).

An escalator, in which treads are held level, and tracks for going trip and return trip are integrally constructed, is well known. Driving mechanism of such an escalator, however, fundamentally relies on a flexible chain. A disadvantage of the flexible chain resides in difficulty in putting it to practical use. The inventor of present application has already applied for a patent right to the Japanese Patent Office, regarding the invention relating to an endless track conveyor apparatus utilizing a parallel link mechanism with flexible links (the Japanese Patent Application No. HEI 1-230458/1989, which is later published as the Laid-open Japanese Patent Application No. HEI 3-95095/1991). Furthermore, the inventor of this application has applied for a patent right to the Japanese Patent Office, regarding the invention relating to an endless track conveyor apparatus utilizing flexible connecting links and auxiliary guide rails capable of keeping the treads level (the Japanese Patent Application No. HEI 1-241770/1989, which is later published as the Laid-open Japanese Patent Application No. HEI 3-106790/1991). These prior arts basically rely on a method, in which driving power is derived from "pushing" force. In this method, therefore, the connecting links and treads are required to have the rigidity of the connecting links and the treads. However, increasing the rigidity entails a disadvantage such that overall weight of the apparatus increases correspondingly. Furthermore the driving mechanism used in these prior arts employs gears or the like means; therefore, accuracy requirement to be met is too high to put the apparatus to practical use.

Drive mechanism for an endless track conveyor apparatus


A system and method to partially vaporize a process or feed water stream does so in a liquid pool zone of a vessel as the stream comes into contact with a heating medium that is less volatile than the process stream. To keep the pool hot, the heating medium can be recirculated through a heater of a pump-around loop or a heater can be placed in the liquid pool. As the process stream is partially vaporized, any solids present in the process stream together with the unvaporized process or feed water stream move into the heating medium. These solids and unvaporized liquids may be further removed from the heating medium in the pool or in the pump-around loop. The vaporized process stream can be further condensed. Any heat recovered can be used to pre-heat the process stream or in the pump-around loop's heater in case of mechanical vapor recovery.

This disclosure is in the field of vaporization and desalination processes such as, but not limited to, those used in mono ethylene glycol ("MEG") reclamation applications, seawater desalination applications, total dissolved solids reduction applications, and general process water treatment for reuse or disposal.
Current vaporization and desalination processes are complicated, expensive, and typically require extensive pretreatment. In some cases, the cost of pretreatment exceeds the cost of the actual vaporization or desalination processes. U.S. Pat. No. 8,652,304 B2 ("Nazzer") discloses a method of extracting dissolved or undissolved solids from a mixture of water and a process liquid or stream. The mixture is introduced into a mixing zone within or upstream of a separation vessel where it is further mixed with a recycle fluid extracted from a liquid pool zone of the separator vessel and pumped through a heat exchanger.
Vaporization occurs in this mixing zone (where more than 99% of the volatile components of the feed stream are vaporized). The resulting stream is then transferred to the separator vessel in which the vapor is separated, with the solid and liquid components falling into the liquid pool zone of the separator vessel. A portion of these solids and liquids that bond to these solids then passes through a stripping zone of the separator vessel. Water residing within the stripping zone displaces the liquids bound to the solids and an aqueous waste stream with dissolved or nondissolved solids results.
Because this method requires a mixing zone for vaporization outside of the liquid pool, the required equipment is difficult to design and prone to scaling and plugging. The method also does not allow for vaporization within the liquid pool and requires the heating medium—i.e., the recycle fluid, lighter than the water in the stripping zone—to be recycled at a rate of at least ten times that of the process feed rate. This high recycle rate is required because the method must limit the temperature difference between the recycle fluid and the process stream in order to avoid thermal degradation effects. Additionally, the method does not allow for partial vaporization with a blowdown.
Last, the method requires a stripping zone for solids removal. A stripping zone is prone to corrosion because of unvaporized (solids) components from the process stream. The stripping zone also presents safety concerns due to the risk of higher temperature oil contacting water. To reduce the safety concern, the oil must be cooled before it touches the water in the stripping zone, but cooling the oil increases its viscosity and ineffective solids separation results. The stripping zone does not allow for partial vaporization because partial vaporization can bring an extensive amount of unvaporized process liquid into the stripping zone.

This patent is subject to a terminal disclaimer.

System and method to partially vaporize a process stream by mixing the stream with a heating medium


Recording is performs that suppresses ink discharge position deviation between scans while suppressing graininess in a case of using multiple types of ink.

Field of the Invention
The present invention relates to a recording apparatus and a recording method.
Description of the Related Art
There is conventionally known a recording apparatus that records images by discharging ink onto a recording medium by driving recording elements, using a recording head having a recording element row where multiple recording elements that generate energy for discharging ink are arrayed. There also is known so-called multi-pass recording in such recording apparatuses, where multiple recording scans are performed as to a unit region to form images.
On the other hand, there is commonly known the so-called time-division driving method for a driving methods of multiple recording elements within a recording element row, where the multiple recording elements are divided into multiple driving blocks, and the recording elements belonging to different driving blocks are driven at different timings from each other. This time-division driving method enables the number of recording elements being driven at the same time to be reduced, thereby enabling a recording apparatus to be provided with the size of the driving power source suppressed.
In a case of recording using the above multi-pass recording, there are cases where discharging position deviation of ink occurs among one type of scan and another type of scan in the multiple scans over a unit region, due to various factors. For example, in a case where floating (cockling) of the recording medium occurs in an arrangement where the recording head is reciprocally scanned in the forward direction and backward direction, the ink discharge direction slightly shifts between the forward direction and backward direction, so there is ink discharge position deviation between a region where recording has been performed by a forward direction scan and a region where recording has been performed by a backward direction scan.
In comparison with this, Japanese Patent Laid-Open No. 2013-159017 describes an arrangement to suppress ink discharge position deviation among two types of scans such as forward scan and backward scan described above. In this arrangement recording data is generated where ink is discharged in the same pixel region by these two types of scans, and further the above-described time-division driving is performed so that the landing positions of dots formed by each of the driving blocks in each of the two types of scans differ from each other. Now, in order for the landing positions of dots formed by each of the driving blocks to differ in a case of the recording head being reciprocally scanned in the forward direction and backward direction, the driving order of multiple driving blocks when scanning in the backward direction is described as being different from the reverse order of the driving order of multiple driving blocks when scanning in the forward direction. Also, in order for the landing positions of dots formed by each of the driving blocks to differ in a case of the recording head being scanned only in one direction, the driving order of multiple driving blocks in a certain type of scan is described as being different from the driving order of multiple driving blocks in another certain type of scan. According to Japanese Patent Laid-Open No. 2013-159017, recording can be realized where ink discharge position deviation between two types of scans is suppressed when performing recording using multi-pass recording and time-division driving.
However, Japanese Patent Laid-Open No. 2013-159017 only describes controlling the driving order of the driving blocks of the recording element row to discharge one certain type of ink. In other words, Japanese Patent Laid-Open No. 2013-159017 makes no mention of how to set the driving order of driving blocks among recording element rows that each discharge ink, in a case of discharging multiple types of ink. Accordingly, while Japanese Patent Laid-Open No. 2013-159017 can suppress ink discharge position deviation among two types of scans when discharging one type of ink, image defects may occur in a case of discharging multiple types of ink.
More specifically, Japanese Patent Laid-Open No. 2013-159017 does not describe the relationship between the driving order of a recording element row discharging cyan ink and the driving order of a recording element row discharging magenta ink, so discharge position deviation between cyan ink and magenta ink may not be suppressed. Further, Japanese Patent Laid-Open No. 2013-159017 does not describe the relationship between the driving order of a recording element row discharging ink with a large dot size and the driving order of the recording element row discharging ink with a small dot size, so discharge position deviation between ink with a large dot size and ink with a small dot size may not be suppressed.

Recording apparatus for reducing discharge position deviation of discharged ink, and recording method for the same


Compounds of the structure ##STR1## wherein R is selected from the group consisting of hydrogen, alkyl radicals of 1-6 carbon atoms, the phenyl radical, and the benzyl radical; and wherein R' is selected from the group consisting of the phthalimido radical and the succinimido radical and of the structure ##STR2## wherein X is CH.sub.2 or C.dbd.O; R" is H, --CH.sub.2 CH.sub.3, --C.sub.6 H.sub.5, --CH.sub.2 C.sub.6 H.sub.5, --CH.sub.2 CH.dbd.CH.sub.2, or ##STR3## and hydrolysis products of said compounds wherein R" is H and the piperidino ring or both the piperidino and the imido ring are hydrolyzed are useful for the control of abnormal concentrations of TNF .alpha. manifested in septic shock, cachexia and HIV infection without substantially effecting the concentration of other cytokines.

Debilitation, i.e. loss of weight, strength, vascular weakness, and other symptoms are natural sequelae of many diseases which afflict humans. These may include, for example bacterial infections such as tuberculosis; viral infections, particularly retroviral infections including HIV infections such as AIDS; various forms of arthritis particularly rheumatoid and degenerative; ulcerative colitis; regional enteritis; and the like. Human patients with these symptoms may present with an acute condition such as septic shock or with a chronic condition such as cachexia.
U.S. Pat. No. 2,830,991 describes a class of therapeutic agents of the general formula I ##STR4## wherein R is selected from the group consisting of hydrogen, alkyl radicals containing 1-6 carbon atoms, the phenyl radical, and the benzyl radical; and wherein R' is selected from the group consisting of the phthalimido radical and the succinimido radical.
The subject matter of this patent and of any other patents or publications identified in this disclosure are incorporated herein by reference.
Preferred compounds within the scope of the above formula I, for use in this invention are:
3-phthalimido-2,6-dioxo-1-ethyl piperidine PA1 3-phthalimido-2,6-dioxo-1-phenyl piperidine PA1 3-phthalimido-2,6-dioxo-1-benzyl piperidine PA1 3-phthalimido-2,6-dioxo-1-allyl piperidine PA1 3-phthalimido-2,6-dioxo-piperidine
As described in the patent, the compounds are produced by reacting an aliphatic dicarboxylic acid, which contains five carbon atoms in a straight chain, the methylene groups of which are substituted by the substituents in accordance with the appropriate general formula, with urea or substitution products thereof or with a primary amine or an acid amide in such manner that water is split off and the ring is closed. If an amino group is present in the aliphatic chain, this group must not exist in free form in this stage of the process, since otherwise there is the danger of this amino group participating in an undesirable manner in the reaction. Instead of using the dicarboxylic acid, it is also possible to employ functional derivatives thereof, such as acid halides, acid esters and acid amides.
Compounds of the glutaminic acid series may be used as starting materials for the present invention. In this case also, the acid halides, esters and amides of glutaminic acid may be employed instead of the acid itself. It is known that glutaminic acids tends to form 5-membered rings with a free amino group. This reaction is undesirable for the purposes of the present invention. The amino group must therefore be substituted or protected prior to the ring-closing reaction. The protection of the amino group may be carried out, when using products of the glutaminic acid series, by introducing the phthalyl, succinyl or like radical in a manner known per se. The proportions of the components used for the ring formation must be such that at least 1 mol of the compound yielding the imide nitrogen is used to one mol of the glutaminic acid component.
The first compound listed above is prepared by reacting 27.7 g. of N-phthalyl glutaminic acid with 66 g. of a 33% solution of ethyl amine in water and slowly heating in an oil bath 160.degree.-180.degree. C., the mixture being maintained at this temperature for 15 to 20 minutes. The reaction product is recrystallised from alcohol by fractionation. It melts at 209.degree. C.
The last compound listed above prepared by reacting 13 g. of phthalyl glutaminic acid anhydride and 6 g. of urea in 75 cc. of absolute xylene for 4 hours at the boiling point of the mixture. Formation of a sublimate takes place with evolution of ammonia and carbon dioxide. The xylene is then distilled off in vacuo and the residue recrystallized from 95% alcohol by fractionation. In addition to some phthalimide and phthalyl glutamine, the required N.sub.2 -phthalyl glutaminic acid imide is obtained, having a melting point of 269.degree.-271.degree. C.
In the patent, the compounds are disclosed as having low toxicity and as useful for certain spasmolytic and antihistaminic effects. The compound 3-phthalimido-2,6-dioxopiperidine is disclosed as being particularly useful as a sedative. This compound was marketed as a sedative under the generic name thalidomide. It was subsequently discovered to be teratogenic and was withdrawn from the market.
Despite its teratogenicity, thalidomide has long been employed for the treatment of erythema nodosum leprosum (ENL) an accute inflammatory state occurring in lepromatous leprosy. See, for example Mellin, G. W., and M. Katzenstein. N. Engl. J. Med. 267:1184 (1962). More recently, it has been shown to be useful in the treatment of graft-versus-host disease by Vogelsany, G. B., S. Taylor, G. Gordon and A. D. Hess. Transplant Proc. 23:904 (1986); for treatment of reheumatoid arthritis by O. Gutierrez-Rodriguez, P. Starusta-Bacai and O. Gutierrez-Montes. The Journal of Rheumatology 16:2 158 (1989); and for treatment of aphthous ulceration in patients positive for HIV antibody. Brit. Med. J. 298:432 (1989).
The tumor necrosis factor (TNF-.sub..alpha.) is one of several cytokines released mainly by mononulear phagocytes together with several other cytokines in response to stimuli to the immune system. It is required for a cell mediated immune response to overcome infections. As its name suggests, it is associated with the destruction of tumor cells. It is not present in measureable amounts in normal sera, but appears, often very rapidly, in response to immunostimulators such as bacterial and viral infections, particularly HIV infections. In the case of chronic infection it may be found in the sera at relatively high or low levels for extended periods of time. It may also appear suddenly in high concentrations in response to release of a toxin by an invading bacteria. It is markedly elevated in ENL.
TNF-.sub..alpha. has been recognized as manifesting a dose dependent toxicity. If present at low levels for too long a period it results in cachexia. At high levels even for a short time it results in septic shock.
Cachexia is a general weight loss and wasting occurring in the course of a chronic disease. More specifically, it is a weight loss not accounted for by decreased caloric intake. It is associated with cancer, the opportunistic infections of AIDS, inflammatory diseases, parasitic diseases, tuberculosis, high dose IL-2 therapy and the like. It is a chronic condition related to chronic diseases.
Septic shock is an acute condition usually, but not always attributed to infection or to toxic substances in the tissue. It is characterized by hypotension due to loss of vascular tone. It may result in patient collapse, or even death if not treated promptly and efficiently.
The retroviruses are a broad group of RNA viruses which, during their replication, employ the reverse transcription enzyme (RT) to convert a RNA message to DNA. The retroviridae family of viruses includes lentiviruses (visna, maedi, progressive pneumonia virus -"slow viruses"), spumaviruses (foamy viruses) and oncornaviruses (types A, B, C, D, RNA tumor viruses). The retroviruses have been shown to infect murine, avian, feline, primate, and human species.
The human immunodeficiency virus (HIV-1) or human T-Cell lymphotropic viruse (HTLV-III) which causes Acquired Immune Deficiency Syndrome (AIDS), AIDS related complex (ARC) and other AIDS related diseases is a retrovirus. TNF-.sub..alpha. functions in an autocrine manner in the induction of HIV-1 expression (G. Poli et al, PNAs Vol 87 p 782, 1990).
It is apparent, therefore, that it is necessary to control the concentration of TNF-.sub..alpha. in the sera to avoid the debilitating effects of abnormal concentrations of this cytokine including, for example, cachexia and septic shock.
Other cytokines which are necessary for a proper immune response are also produced by mononuclear phagocytes. These include, for example, various interleukins such as IL-1, IL-6, IL-8 and the granulocyte macrophage colony stimulating factor, GM-CSF. Still other cytokines are produced by the T-cells. It is desirable to control the concentration of TNF without appreciably affecting the concentration and activity of other cytokines.
Heretofore, antiinflammatory and immunosuppresive steroids such as prednisolone and dexamethasone have been employed to treat the debilitating effects of TNF-.sub..alpha.. Unfortunately, these therapeutic agents also block the production of other cytokines so that the patients become susceptible to life threatening infections.

Method of treating abnormal concentrations of TNF .alpha.