In lithium iodine electrochemical cells, control of polyvinylpyridine film thickness and/or polyvinylpyridine film surface area coverage and/or control of the quantity thereof on or with respect to the lithium anode operative surface directly affects cell voltage characteristics during discharge, allowing the tailoring of the voltage characteristics near cell end-of-life (EOL) in a useful way.

This invention relates specifically to lithium-iodine cells, including lithium anodes and an iodine-poly (2-vinylpyridine) complex cathode or similar cathode material. The operative surface(s) of the lithium anode is coated or otherwise covered with a layer of polymeric organic electron donor material such as poly (2-vinylpyridine), sometimes referred to as P2VP, other materials being known in the art. Briefly, the poly (2-vinylpyridine) or other polymeric organic donor material on the lithium anode may be applied by painting or otherwise depositing a coating of the polymer dissolved in tetrahydrofuran at room temperature. Such an arrangement is more fully described in U.S. Pat. Nos. 3,957,533 and 4,071,662, both to Mead, et al. Alternatively, a self-supporting film of polymeric organic donor material such as poly (2-vinylpyridine) may be placed over the operative anode surfaces. Such film is typically extruded. This is more fully described in U.S. Pat. No. 4,182,798 to Skarstad, assigned to the same assignee as this invention. The term "operative surface(s)" refers to those surface areas of the anode which are exposed in the cell to cathode material.
General teachings concerning cathode materials for lithium iodine cells may be found in U.S. Pat. No. 4,340,651 to Howard, et al. also assigned to the same assignee as this invention. As an example of cathode material, a mixture of iodine and poly (2-vinylpyridine) is heated at an elevated temperature for a time adequate to form a complex composition. The cathode material is then poured into a cell container into which a lithium anode having a coating or film of poly (2-vinylpyridine) thereon (a preferred polymeric organic donor material) has been previously positioned. The cell container is then hermetically sealed. Such cells, in a relatively thin form having a thin planar anode having, most often, two opposed major lateral surfaces, have found particular application in the medical field for heart pacemakers and other medical devices.
Lithium-iodine cells for medical applications have typically been case-positive with cathode material on two sides of a central lithium anode resulting in relatively highly efficient cells. Such cells are so efficient in discharge that they tend to exhaust most of the cell capacity before exhibiting rapid voltage decay at end-of-life (EOL).

Lithium-iodine electrochemical cells with improved end of life characteristics


An ink applicator or donor is provided in which a belt tracks the surface of a prim member over a defined distance of the print member. A geometric conformance device is located inside the belt to ensure that the belt is equidistantly spaced apart from the print member surface.

Developing or donor rollers for printers are well known, these rollers often being electrostatically charged to carry charged ink toner from a toner supply to a print cylinder. A latent electrostatic image carried on the print cylinder then attracts the toner from the donor roll onto the print cylinder. The image is thereby developed on the print cylinder.
For example, U.S. Pat. No. 5,315,061 to Suzuki et al. shows a developing roller having a conductive surface with dielectric bodies thereon. A charged toner is attracted to the roller by micro fields which arise between the dielectric bodies and the conductive surface. The toner then is transferred to a print belt which carries a latent image to be developed. A doctor blade can limit the thickness of the ink carried by the developing roller.
In prior art systems using a developing roller, such as the '061 patent, the developing roller only contacts the print member surface in a single location.
However, proper development of an image requires a certain minimum time for the latent image on the print surface to attract the necessary ink or toner. By contacting only a single location of the print surface, the developing rollers of the prior art are limited by the time necessary to develop properly the image on the print surface.
The developing roll prior art devices thus limit the speed and quality of the developed image, since the quality of the developed image, the narrowness and repeatability of its various tolerances, the insensitivity to ambient conditions during development, and the brevity of time or "speed" with which development can be accomplished depend largely on the nature of the ink applicator and its interaction with the print member.
U.S. Pat. No. 3,689,933 shows a developing station which covers a larger area of a print cylinder surface than a developing roller. However, the specifics of the developing station, including its reliability and quality, are not described.
European Patent Application 0141 663 shows a donor roller contacting a print surface at a single tangential point of a print cylinder. It also describes that an endless belt may be substituted for the donor roller, although this belt as well presumably would only contact the print cylinder at one point.

Belt applicator for developing ink or toner on a print member


A method for winding into an electrochemical cell, a plurality of flexible strip members each having a leading end portion, including the steps of positioning a first and second arbor half to face each other but not in contact, feeding the leading end portions between the first and second arbor halves, bringing the arbor halves together to capture at least a portion of the leading end portions, rotating the first and second arbor halves to wrap the leading end portions around a first curvilinear driving surface of the first arbor half, and applying pressure with a roller to the flexible strip members during at least a portion of the time the arbor halves are rotating. An electrochemical cell having a central opening extending the length of the axis of the cell is also described.

In general, this invention relates to methods for winding into an electrochemical cell, a plurality of flexible strip members as well as electrochemical cells produced by such methods. More particularly, this invention relates to a method for winding into an electrochemical cell, a plurality of flexible strip members each having a leading end portion, that includes bringing a first generally flat surface of a first arbor half toward a second generally flat surface of a second arbor half along a direction generally perpendicular to the first generally flat surface, to capture at least a portion of the leading end portions therebetween, and rotating the first and second arbor halves with the leading end portions captured, to wrap the leading end portions around a first curvilinear driving surface of the first arbor half; and it relates to an electrochemical cell, produced by such a method, having a central opening that extends the length of the axis of the cell and is circumscribed by a first conducting flexible plate of the cell.
Various techniques and apparatuses for spirally winding electrochemical cells into a generally cylindrical "jelly roll" configuration are known. Typically, a mandrel or split arbor is used to wind the strip-like components of the electrochemical cells. These mandrels or split arbors are either solid with grooves or notched lands, clothespin shaped, or split into two separate halves which slide together (concurrently or at different times) along the same direction to grab and hold the strip-like components for winding. Even if the two arbor halves are tapered such that their tips have the smallest cross-section (see FIG. 6 of U.S. Pat. No. 4,203,206 and FIG. 1 of U.S. Pat. No. 4,559,700), this sliding motion often causes the strip-like components to be pushed-out of, or to buckle between, the arbor halves. Additionally, since the known split arbors slide together, the strip-like cell components must be either (1) fed between the arbor halves in a "pre-sandwiched" form or (2) positioned against an arbor half and held tightly together by some means as shown in FIG. 7C in U.S. Pat. Nos. 4,203,206 and 4,360,140. This adds another step to the winding process and adds another mechanism to the winding apparatus, thus slowing down, adding costs to, and increasing the complexity of the winding process.
Repeatability of high-quality wound cells is low for the known winding processes and apparatuses. In particular, as the arbor halves are pulled from a wound jelly roll, oftentimes the inside windings pull out with the arbor halves causing "spiralling" of the cell. These cells must be scrapped. Furthermore, it is desirable to configure the cells so that cells can easily and quickly be filled with a maximum specified amount of electrolyte. Since cells are usually filled with electrolyte through their centers, it is difficult to easily and quickly fill cell configurations produced by known jelly roll winding processes because the centers of these cell configurations are "filled" with separator material (see FIGS. 7D and 7E of U.S. Pat. Nos. 4,203,206 and 4,360,140) or jelly roll components (see FIG. 15 of U.S. Pat. No. 2,506,314 or FIGS. 24 and 25 of U.S. Pat. No. 2,340,340). A desirable electrochemical cell configuration can be produced by grabbing and winding the leading ends or edges of the malleable conducting plates or electrodes to be wound. However, known cell winding processes and apparatuses do not grab and hold the leading ends or edges of the malleable conducting plates or electrodes because this will cause the leading ends to crack. Therefore, the known processes include methods, where, only the separator strips are grabbed and wound prior to introducing any malleable conducting plates or electrodes (see FIG. 7E of U.S. Pat. Nos. 4,203,206 and 4,360,140).
It is a primary object of this invention to provide a method for winding an electrochemical cell capable of efficiently producing quality cells. It is another object to produce an electrochemical cell by such a method having a configuration that is less costly to make and may extend the life of the cell.

Method of winding an electrochemical cell and cell produced by the method


Polymer blend materials composed of an aromatic polyamide and flexible polyamide wherein the aromatic polyamide molecules are uniformly dispersed in a matrix of the flexible polyamide which are produced by first blending the flexible polyamide and monomer(s) for the aromatic polyamide in a solvent, then next polymerizing the monomer(s) in the presence of a phosphite compound, resulting in a transparent gel product capable of being fabricated into useful shaped articles without causing marked phase separation observed in polymer blend materials obtained by conventional coagulation method. The in situ formed aromatic polyamide is uniformly dispersed in the flexible polyamide matrix even in fabricated forms, giving improved transparency over the starting flexible polyamide and improved resistance toward chemicals such as acids, especially after heat treatment.

Polymer blend materials composed of dispersed rigid-rod polymers, such as certain types of aromatic polyamides and a flexible polymer matrix, are gaining increased attention as new materials wherein the host matrix polymer is modified at the molecular level by the incorporation of the rigid-rod polymer in a dispersed form. Such a polymer blend material is expected to exhibit not only some of the benefits of a rigid-rod polymer as regards mechanical properties, thermal stability, resistance toward chemicals, and other properties, but also the benefits of a flexible polyamide, such as moldability. For example, improvement in tensile properties of a flexible polymer by blending a rigid-rod polymer therein has been reported. The exact definition of "rigid-rod" is given by using the term "rigid" in Japan Patent (Not examined) No. 52-131436 and U.S. Pat. No. 4,228,218. All of the polymers which are not rigid-rod ones are defined as flexible polymers. Polymer blend materials, including rigid-rod polymeric molecules dispersed at the microscopic level, are of great interest as novel materials for many applications.
However, it is commonly difficult to disperse one polymer in another polymer. Phase separation or aggregation thermodynamically inevitable. Several efforts have been examined to overcome the difficulty of blending rigid-rod polymers with flexible polymers. A coagulation method is conventionally employed for the preparation of polymer blend materials which include a rigid-rod polymer. In this method, a homogeneous solution including a rigid-rod polymer and a flexible polymer are put rapidly into a poor solvent, resulting in a precipitate of polymer blend materials. The coagulation process is insufficient to achieve the fine dispersion of rigid-rod polymers because entropy-driven demixing might take place during coagulation even though nonequilibrium solidification is expected.
As for polymer blend materials composed of poly(p-phenyleneterephthalamide) [PPD-T] and nylon, which are of concern in the present invention, the formation of 30 nm-diameter microfibrils of PPD-T are observed for blends of PPD-T/nylon obtained by a coagulation method as is previously reported in J. Macromol. Sci. Phys., B17(4), 591 (1980).
Moreover, a coagulation method involves another disadvantage. A rigid-rod polymer such as poly(p-phenyleneterephthalamide) [PPD-T] usually requires strong acids as solvents due to its poor solubility. To prepare homogeneous solutions, a large amount of strong acid solvent, e.g., sulfuric or methanesulfonic acid, must be employed. However, the use of strong acids induces polymer degradation and is not economical for obtaining a large amount of polymer blend materials, especially for industrial processes.
Alternatively, a comparatively new method of blending a rigid-rod polymer in a matrix polymer is known wherein the rigid-rod polymer is synthesized in situ in the presence of the matrix polymer.
In these methods, rigid-rod polymers are synthesized in a dissolved or molten matrix of flexible polymer. For example, Ogata et al. synthesized rigid-rod polyamides such as PPD-T and PBA [poly(p-benzamide)] and rigid-rod polyesters such as PHB [poly(p-hydroxybenzoate)], etc., in the presence of matrix polymers such as polyarylate and elastomers dissolved in chlorohydrocarbons etc., which, however, resulted in a suspension of rigid rod polymer, resulting in opaque films containing large aggregations of 500 nm or more, as is described in Polym. J., 22(2), 85 (1990), Chem. Mater. 4, 1123 (1992), J. Polym. Sci., Part A: Polym. Chem., 31, 597 (1993). Rosch reported that a mixture of PBA and PABC [poly(p-aminobenzoyl- caprolactam)] was formed in situ in a nylon matrix, resulting in a phase separated structure between nylon 6 and PBA/PABC [Polym. Prepr. 33(1), 370 (1992)]. It is true that these attempts are considered to be advantageous in that conventional aprotic solvents or no solvent is employed to produce polymer blend materials including rigid-rod polymers, but such observations led to the conclusion that no fine dispersion of rigid-rod polymers at a nanometer level was obtained which thereby brings about poor transparency.
It is obvious that even with these methods, including the in situ methods conventionally employed to date, entropy driven demixing of polymers occurs to some extent. A production method of the polymer blend materials including rigid-rod polymers without using strong acids and giving uniformly dispersed forms of aromatic polyamides therein has not been established and such systems are still desired.
The present invention relates to polymer blend materials produced by in situ synthesis of a rigid-rod polyamide through the phosphorylation polycondensation reaction in the presence of a soluble polyamide. The phosphorylation polycondensation reaction in the presence of a dissolved polymer matrix has been previously reported as follows. The synthesis in a poly(4-vinylpyridine) matrix and a poly(ethyleneoxide) matrix, respectively, has been described in Journal of Polymer Science: Polymer Chemistry Edition, Vol. 18, 851 (1980), and Journal of Polymer Science: Polymer Chemistry Edition, Vol. 18, 1099 (1980). The synthesis in the matrices of poly(vinylpyrrolidinone), poly(4-vinylpyridine) and poly(ethyleneoxide) has been described in Journal of Polymer Science: Polymer Chemistry Edition, Vol. 18, 2875 (1980).
However, these methods are quite different from the present invention. In particular, polyamides are not employed as matrix polymers, the matrix polymers are merely employed as reaction promoters to produce high-molecular-weight aromatic polyamides, and improved transparency and improved resistance toward chemicals of resultant polymer blend materials over the starting matrix polymers, which were discovered in the present invention, are not mentioned. Additionally, transparent gel formation during the synthesis and fine dispersion of the synthesized aromatic polyamides in the matrix polymers, which were discovered in the present invention, are not mentioned. Furthermore, the polymers which are employed are water soluble, and therefor do not remain in the final product.
The above mentioned in situ reaction was conducted by using N-methyl-2-pyrrolidinone ("pyrrolidinone" is also referred to as "pyrrolidone") as a solvent suitable for the phosphorylation reaction and capable of dissolving the matrix polymers. Although it is known that polyamides such as nylon 6 could dissolve in amide type solvents at the boil such as N-methyl-2-pyrrolidinone as was described in U.S. Pat. No. 2,958,677, however, the in situ synthesis through the phosphorylation reaction in the presence of polyamides such as nylon 6 has not been examined.
It should be mentioned that the present invention is mainly aimed towards a polymer blend material composed of a rigid-rod aromatic polyamide and a flexible aliphatic polyamide. However, the present invention is found to be effective also for a polymer blend material from a nonrigid-rod aromatic polyamide and a polyamide which is simply soluble in a certain solvent. Therefore, in a broad sense, the present invention relates to a polymer blend material comprising an aromatic polyamide and a soluble polyamide as the title indicates.

Polymer blend materials composed of an aromatic polyamide and a soluble polyamide

Dainippon Ink and Chemicals, Incorporated


A master coupling link assembly comprises a master coupling link and at least one sub-coupling link. The master coupling link has a first eye dimensioned to receive a lifting hook and at least two second eyes separated from the first eye. The at least one sub-coupling link is coupled to the master coupling link at one of the at least two second eyes, and the sub-coupling link is formed with the master coupling link.

Master links or master coupling links are typically a single connection point to which a crane or hoist hook can be attached. Conveniently, master coupling links allow for slings, chains or other forms of tension elements extending to various locations on a load to be coupled together in a way that permits a wide range of adjustment for each such element. U.S. Pat. No. 4,068,467 discloses one such master link.
Master links are subject to great loads and stresses. In addition, master links are used in environments where providing for speeding rigging and de-rigging is advantageous. Conventionally available master coupling links do not provide a sufficiently robust yet flexible solution.


Symmetrical cross coupled PLL circuits provide pseudo-synchronization between two independent clock signals, especially for use in fault tolerant applications. Independent oscillators provide input signals to each of the PLL circuits. The PLL circuits include divide circuitry that provide output signals at some sub multiple of the input clock signals. The phase relationship between the output clock signals from the cross coupled PLL circuits is monitored by phase detector circuits. If the phase of one output clock signal is determined to be advanced relative to the other output clock signal, the phase of that output clock signal is retarded by temporarily increasing the divide ratio of the PLL circuit producing the phase advanced signal.

This invention relates generally to a system and method for maintaining two or more clocks in pseudo-synchronization, and more specifically to a system and method using cross coupled phase lock loop circuits to maintain clocks in pseudo-synchronization, the system and method being especially applicable to fault-tolerant applications. The invention further relates to a system and method for maintaining the pseudo-synchronized clocks synchronized to a system clock.
Phase lock loop (PLL) circuits are devices that allow one clock (the slave clock) to lock onto or follow another clock (the master clock) in frequency and in phase. PLL circuits are often used in fault-tolerant systems that require redundancy. Redundant channels are provided, for example, in aircraft navigation and control systems to ensure that these systems remain operative even if a fault occurs in one of the channels. Upon the occurrence of a fault in one channel, the system employs the other channel to remain operative. The use of the master/slave concept provides a clock signal having the same frequency and phase relationship for each of the channels so that communication between the channels can be maintained.
There are a number of problems associated with the conventional master/slave PLL concept. In order to achieve complete redundancy, as is often required in fault-tolerant applications, it is desirable to have fully independent channels. With fully independent channels, each channel is provided with and runs on its own separate oscillator. In the conventional PLL structure, however, only a single oscillator is used and multiple clock signals are generated and synchronized to that single oscillator. Such a system results in lack of total redundancy because of serial operations based on the single oscillator. If the single oscillator fails, for example, the redundancy is inoperative. Additionally, in a conventional master/slave clock arrangement, the slave PLL must be able to either advance the phase or retard the phase in response to the performance of the master PLL. This can result in an instantaneous clock signal frequency greater than the nominal clock signal frequency. All devices utilizing the clock signal must therefore be over designed for this higher frequency and such over design can result in increased cost and complexity.
In the prior art, if two independent oscillators were employed to generate two independent clock signals to achieve total redundancy and PLLs were used to synchronize the two clock signals, such prior solutions resulted in instability of the system. For example, if the phase of the clock signal used by a first channel A was detected to be advanced by 90xc2x0 relative to the phase of the clock signal used by a second channel B, the PLL for channel A might attempt to retard the phase of its clock signal by 90xc2x0 to align with the clock signal of channel B. Simultaneously the channel B PLL might attempt to advance the phase of its clock signal by 90xc2x0 to align with the clock signal of channel A. The result after both corrections are made would be a relative phase of xe2x88x9290xc2x0. The process then repeats itself in reverse. The loop thus becomes unstable.
Thus, a need exists for a system and method to achieve pseudo-synchronization between two or more totally independent clock signals that overcomes the deficiencies of prior solutions.
In accordance with one embodiment of the invention, two PLL circuits, each associated with an independent channel, are cross coupled. Each channel also includes an independent oscillator, each providing a clock signal having a nominal frequency nf. Each PLL operates by dividing the input clock signal to generate an output clock signal having a nominal frequency f. Phase information is exchanged between the two PLLs at a frequency (1/m) f. A phase detector measures the relative phase relationship between the two exchanged clock signals and then adjusts the phase of the PLL output if the phase difference exceeds a predetermined value. If the phase difference exceeds the predetermined value, the phase of the leading clock signal is retarded by temporarily increasing the divide ratio of the PLL providing the advanced phase clock signal.


An improved image registration system for a multicolor inkjet printer/plotter. The inventive system comprises a carriage assembly for retaining multiple inkjet cartridges. Each cartridge has a plurality of nozzles adapted to eject ink in response to the application of an electrical signal thereto. A first mechanism is provided for moving said carriage assembly means in a first axis. A second mechanism is provided for moving print media in a second axis transverse to the first axis, said first axis being a scan axis and said second axis being a media axis. A first position encoder senses the position of the carriage assembly in the first axis and a second position encoder senses the carriage assembly in the second axis and providing position encoder signals in response thereto. A control circuit provides electrical signals which cause the nozzles in the inkjet cartridges to eject ink onto the media and create an image thereon in response to timing signals. The inventive system includes a sensor module which optically senses the image and provides a set of sensed signals in response thereto. The sensed signals are processed to provide timing signals for use in correcting the image misregistration.

1. Field of the Invention
The present invention relates to printers and plotters. More specifically, the present invention relates to inkjet printers and plotters having multiple pens for multi-color operation.
While the present invention is described herein with reference to illustrative embodiments for particular applications, it should be understood that the invention is not limited thereto. Those having ordinary skill in the art and access to the teachings provided herein will recognize additional modifications, applications, and embodiments within the scope thereof and additional fields in which the present invention would be of significant utility.
2. Description of the Related Art
Inkjet printer/plotters, such as those sold by Hewlett Packard Company, offer substantial improvements in speed over the conventional X-Y plotter. Inkjet printer/plotters typically include a pen having an array of nozzles. The pens are mounted on a carriage which is moved across the page in successive swaths. Each inkjet pen has heater circuits which, when activated, cause ink to be ejected from associated nozzles. As the pen is positioned over a given location, a jet of ink is ejected from the nozzle to provide a pixel of ink at a desired location. The mosaic of pixels thus created provides a desired composite image.
Inkjet technology is now well known in the art. See, for example, U.S. Pat. No. 4,872,027, entitled PRINTER HAVING IDENTIFIABLE INTERCHANGEABLE HEADS, issued Oct. 3, 1989, to W. A. Buskirk et al. and U.S. Pat. No. 4,965,593, entitled PRINT QUALITY OF DOT PRINTERS, issued Oct. 23, 1990, to M. S. Hickman, the teachings of which are incorporated herein by reference.
Recently, full color inkjet printer/plotters have been developed which comprise a plurality of inkjet pens of diverse colors. A typical color inkjet printer/plotter has four inkjet pens, one that stores black ink, and three that store colored inks, e.g., magenta, cyan and yellow. The colors from the three color pens are mixed to obtain any particular color.
The pens are typically mounted in stalls within an assembly which is mounted on the carriage of the printer/plotter. The carriage assembly positions the inkjet pens and typically holds the circuitry required for interface to the heater circuits in the inkjet pens.
Full color printing and plotting requires that the colors from the individual pens be precisely applied to the media. This requires precise alignment of the carriage assembly. Unfortunately, mechanical misalignment of the pens in conventional inkjet printer/plotters results in offsets in the x direction (in the media or paper axis) and in the y direction (in the scan or carriage axis). This misalignment of the carriage assembly manifests as a misregistration of the print images applied by the individual pens. In addition, other misalignments may arise due to the speed of the carriage, the curvature of the platen and/or spray from the nozzles.
One conventional approach for aligning the pens involves the use of optical drop detectors. This technique is described and claimed in U.S. Pat. No. 4,922,270, issued May 1, 1990, to Cobbs et al. and entitled Inter Pen Offset Determination and Compensation in Multi-Pen Thermal Ink Jet Printing Systems, the teachings of which are incorporated herein by reference. The optical drop detectors detect the position of each ink drop as it leaves the pen. The system then calculates the point of impact of the drop on the print media. Unfortunately, the actual impact point often differs substantially from the calculated impact point due to angularity. Angularity results from the movement of the pen in the scan axis as ink is being ejected. That is, there is a delay between the time that the drop of ink is ejected and the time that the drop impacts the media. This flight time delay causes the drop to traverse an angular path toward the media. If not accurately calculated and corrected, this would cause a distortion in the print image. However, inasmuch as accurate calculation and correction has heretofore been difficult to achieve, this technique has been found to be inadequate for current product specifications for full color printing.
In another conventional approach, a test pattern is printed and the print image is sensed optically to determine the degree of image misregistration. This technique is disclosed and claimed in copending U.S. patent application Ser. No. 07/786,145, entitled Automatic Print Cartridge Alignment Sensor System, filed Oct. 31, 1991 by Robert D. Haselby (the teachings of which are incorporated herein by reference). However, this system is slow in that it required a self-calibration reference pattern for aligning the sensor.
Thus, there is a need in the art for systems and techniques for providing accurate image registration in multicolor, multi-pen inkjet printer/plotters.

Multiple inkjet print cartridge alignment by scanning a reference pattern and sampling same with reference to a position encoder


The combined base member and bit holder with protected retainer which comprises this invention includes a bit holder adapted to receive the shank of a suitable cutting bit. The bit holder has a head which permits movement of the bit holder within the base member so as to expose means to receive a retaining member while that portion of the bit holder protrudes beyond the base member. The base member is provided with an opening or recess to receive the retainer so as to prevent accidental dislodgement. After installation of the retainer the bit holder is moved within the base member so as to engage the retainer at least partly in the recess provided in the base member for it, whereafter a spacer is driven between the head of the bit holder and body of the base member to hold the bit holder in place. A boss may be provided on the base member to prevent undue movement of the spacer. Means may also be provided in conjunction with the boss and/or base member to prevent the legs of the spacer from being spread so that the spacer also is prevented from accidental dislodgement. The bit holder may be provided with a flat to let it pass by the boss or it may be provided with a notch to receive the boss when the bit holder is moved to its initial position for installation of the retainer.

The present invention is especially applicable to mining machines and the like of the type having a primary drive member to which is affixed one or more base members each adapted to receive a bit lug which in turn receives a bit or cutting tool. The drive member, which in turn is driven by appropriate mechanisms, may take a number of forms such as a chain, a rotating wheel, a rotating drum, or a rotating arm and the like. The bits or cutting tools, which may also be those found in machinery other than mining, such as road working and earth moving equipment, may also take various forms such as mining machine cutter bits, road ripping elements, digger teeth and the like.
The bit lug, also known in the trade as a bit block or bit holder, may receive various kinds of bits or cutting elements. To this end the lug is provided with a perforation designed to receive the shank of the particular style of bit for the particular work to be performed. The precise relationship between the bit lug and bit does not constitute a direct part of the instant invention. Various means may be provided for retaining the bit or cutting element within the lug; again these do not constitute a direct part of the instant invention. By the same token the invention is not directly concerned with the particular kind of equipment to which the base member, that which receives the bit lug, is affixed. The invention is primarily concerned with the manner by which the bit lug is secured within a cavity provided for it in the base member. As indicated herein, means are provided to retain the bit lug within the base member and the invention is directly concerned with protecting these latter means.
No search of the prior United States patent art has been made in connection with this invention. It is known, however, that there are many patents which show various relationships between bit lugs and base members. Prior art workers recognized the importance of providing arrangments by means of which the bit lug itself, as distinguished from the bit per se, could be easily and readily removed from the respective base member in which it was mounted. A number of "pin-on", "wedge-on" and other arrangements were developed for accomplishing such result. U.S. Pat. No. Re. 28,310 discloses a popular "pin-on" arrangement for securing a bit lug to a base member. Various "wedge-on" arrangements are shown in U.S. Pat. Nos. 3,342,531; 3,834,764; 4,057,294; 4,275,929 and 4,337,980. (Patents such as U.S. Pat. Nos. 3,397,012 and 3,622,206 disclose various means and arrangements for enabling quick and easy removal of a bit from a bit lug. Other such means and arrangements are shown in U.S. Pat. Nos. 2,965,365 and 3,114,537.)
There is other art which is at least indirectly pertinent. U.S. Pat. Nos. 3,679,265 and 3,888,133, for example, show chains made up of various interdigitated bit-carrying links, connecting links, spacers, connecting pins and retaining means. U.S. Pat. No. 3,888,133 is of interest in that it does disclose an arrangement by which the means to retain a connecting pin within a number of connecting links, bit-carrying links and spacers is prevented from being accidentally dislodged and is protected from wear. Some of the principles of this latter patent are adopted for use in the instant invention. In this connection, U.S. Pat. No. 3,397,012 (FIG. 12) is also of interest.

Combined base member and bit holder with protected retainer


A memory cell is formed in which N channel transistors A and P channel transistors B having respectively different conduction types are alternately fitted. The channel section of the N channel transistor A and the P-type drain 7a of the P channel transistor B are commonly used in a shared manner, and the channel section of the P channel transistor B and the N-type source 5b of the N channel transistor A are commonly used in a shared manner; thus, it is possible to achieve high integrity. Moreover, the junction between the adjacent P-type drain 7a and N-type source 5b is always maintained in a reverse bias state so that the P-type drain 7a and the N-type source 5b are separated. With this arrangement, the separation area between the respective transistor elements is minimized so that it is possible to provide a semiconductor device which can achieve miniaturization and high integrity.

In general, a ROM (Read Only Memory), utilized for writing various pieces of program information, has a MOS (Metal Oxide Semiconductor) transistor construction having a gate, a source and a drain combined in a matrix format, that is, a construction which has laminated metal, oxide (insulator) and semiconductors, and which cuts off or connects the source and the drain of the memory-use transistor, or sets two types of threshold values, in accordance with written information, so that it detects a current flowing between the drain and the source in a manner so as to correspond to "1" and "0" in stored information.
For example, as shown in FIGS. 7(a) and 7(b), such a conventional mask ROM of an NOR type with high integrity includes a P-type semiconductor (Si) substrate 51, N-type semiconductor areas 57, and gate electrodes 59. Here, the N-type semiconductor areas 57, formed into a plurality of stripes in one direction, are formed on an upper portion of the P-type semiconductor substrate 51, and the gate electrodes 59, formed into a plurality of stripes that extend perpendicular to these N-type semiconductor areas 57 through a gate oxidation film 58, are also installed on the upper portion of the P-type semiconductor substrate 51. Memory cells are placed at intersections between the N-type semiconductor areas 57 and the gate electrodes 59.
Source areas and drain areas, made of the adjacent N-type semiconductor areas 57, are located below the respective gate electrodes 59, and operation channels 54 are formed between the source areas and the drain areas. In the case when the threshold voltage of each operation channel 54 is preliminarily set to a predetermined value for each portion, upon application of a voltage not less than the predetermined value to the gate electrodes 59 through word lines A1, A2 . . . , the operation channels 54 are allowed to conduct, and electrons are allowed to shift from the source side toward the drain side (in this case, bit lines f1, f2 . . . , have been preliminarily set so as to satisfy drain voltage>source voltage); thus, a drain current is allowed to flow. Consequently, the writing process for information "1" is carried out.
In other words, when a positive voltage is applied to the gate electrodes 59, in the operation channel 54, a positive hole of the P-type semiconductor substrate 51 is pushed inward, and in contrast, a negative charge that is an electron is induced. When the positive voltage of the gate electrodes 59 increases, the number of electrons in the operation channel 54 increases, with the result that an N-type transmitting layer is formed, and this allows the source area and the drain area that have the same N-type to conduct, thereby allowing a current to flow. Here, these transistors that form the N-type transmitting layer as the operation channel 54 are referred to as N-channel transistors. In contrast, those transistors that form the P-type transmitting layer as the operation channel 54 are referred to as P-channel transistors.
Here, in the case when boron (B) ions, which form an impurity to Si, are injected into the operation channel 54, since B is trivalent while Si is tetravalent, in this boron (B) ion injected area 55, there is a lack of one electron in order to form a covalent bond with an Si atom. Here, an attempt is made to compensate for the lack of one electron by gaining one electron from an adjacent Si atom so as to complete the covalent bond. As a result, a positive hole is formed at the original Si position.
When the concentration of boron (B) ions in the operation channel 54 is made high, the number of positive holes increases, with the result that even upon application of a predetermined positive voltage to the gate electrode 59 as described above, there is no increase in the number of electrons. This makes it possible to write information "0".
In other words, in the mask ROM, data is fixed at the time of manufacturing a device. Therefore, as described above, when an attempt is made to write "0" upon application of a predetermined voltage, boron (B) ions are preliminarily injected into the operation channel 54 at a high concentration at the time of the manufacturing process thereof.
However, in the above-mentioned semiconductor device, as illustrated in FIG. 7(a), the mask ROM of the NOR type needs 2F in the lateral direction pitch X per bit, and also needs 2F in the longitudinal direction pitch Y per bit, in the case of design rule F. For this reason, the area of the mask ROM of the NOR type occupies 4F.sup.2 per bit, raising problems in achieving a small-size, highly integrated device.
Here, F in the above-mentioned design rule F refers to a dimension, for example, given as F=0.25 .mu.m.


An emergency exit door assembly for a vehicle. The door assembly can include a door panel that is movably coupled to the wall of the vehicle. The door panel can have an inner surface and an outer surface. The door panel can be configured for selective movement between a closed position and an open position in which an opening within the wall is exposed. A headboard component can be incorporated into the door panel, and a bed pedestal within the vehicle can be positioned in proximity to the headboard component when the door panel is in a closed position.

Motorhomes and other recreation vehicles are typically made with a single door. This single door is typically located near the driving area for efficiency. Being the only door, the single door provides access to all spaces of the recreational vehicle. Thus, to access all spaces of the recreational vehicle, a user may have to traverse other living spaces in the vehicle. The requirement to traverse other living spaces can become an issue in the case of an emergency such as a fire. For example, the fire may be near the single door thus making a safe exit from the vehicle dangerous. Thus, there is a need for an emergency exit that provides for emergency egress from the recreational vehicle. Additionally, there is a need for an emergency exit that provides passengers a simple and safe egress route from within the recreational vehicle. Furthermore, there is a need for an emergency exit that can be efficiently integrated with the living space of the recreational vehicle, taking into consideration the recreational vehicle's inherent size constraints.

Systems and methods for egress from a motor home


A programmable viticulture management system includes a mechanized device for removing excess undesired portions of plants advances through a vineyard to perform control operations on two rows or half-rows of grape vines simultaneously. Accessories mount to the mechanized device and include various engagement members for engaging the vines. A control system automatically varies the velocity of the engagement members in relation to the vehicle speed. The control system also receives various inputs and provides information on multiple growth control practices.

1. Field of the Invention
The present invention relates to an automated vineyard management system for managing grape quality and yield while lessoning dependence on manual labor to accomplish required practices.
2. Description of the Prior Art
Heretofore, grapes have been primarily cultivated utilizing manual labor with the various trimming, thinning and other removal of excess portions of the grape vine foliage accomplished primarily by hand. Although some of the steps in grape cultivation have been mechanized, an overall system providing for management and control of the devices utilized for the various operations have been limited to devices dedicated to a specific step. Moreover, the various operations have not been coordinated into one coherent system while providing management information and feedback to control the mechanized operations.
Although dedicated agricultural implements have been utilized in the past, a system has not been provided that coordinates the various operations. Moreover, prior systems have not provided management to control the various operations to arrive at a desired yield that maximizes fruit quality. Heretofore, there have not been systems that would allow for controlling the speed of the machinery, as well as accounting for the variety of grape, the desired yield and other viticultural characteristics.
It can be seen that a new and improved management system is needed for cultivation of grapes that minimizes the labor needed and that utilizes mechanical methods for controlling production. A management system should provide for controlling various machinery and for measuring the effects of the machinery for certain processes. Such a system should also provide for vehicle management controls that maintain predetermined operational parameters. A management system should also track historical data to aid in conducting various cultivation operations and the level at which the mechanized systems should be operated. The present invention addresses these problems as well as others associated with mechanized grape cultivation.


The invention relates to such semiconductor devices comprising: a wiring layer with a predetermined pattern formed over a major surface of a semiconductor substrate through an insulating film, a diffusion layer formed under a contact hole formed in said insulating film in an adjacent region of the wiring layer, and a conductive layer deposited into said contact hole in a state of being connected to said wiring layer.

This invention relates to semiconductor devices and a fabrication method thereof, for example, to static RAMs (Random Access Memories).
Conventionally static RAMs, for example, have severe restrictions on pattern layouts, because many wirings such as ground wires and bit lines have to be passed through regions of small area. Thus, in silicon gate MOS integrated circuits, a so called "direct contact" method is generally known, in which gate electrodes are not connected to diffusion layers (sources, drains, or regions corresponding thereto) by conventional metal wiring layers such as Al or the like but are connected directly to the diffusion layers using polysilicon or the like. By using the direct contact method, pattern layouts in said static RAMs or the like is defined more freely, and the degree of integration increases, because metal wiring layers such as, for example, power source supply wires, can be disposed directly over connecting parts or the like of the gate electrodes and the diffusion layers.
However, semiconductor devices fabricated by said direct contact method have several serious problems which cannot be avoided in their processes. Hereinbelow, an example of a fabrication process of semiconductor devices by the direct contact method and its problems will be discussed in regard to FIGS. 5A to 5H. To facilitate the understanding, the figures are partly exaggerated.
First, as shown in FIG. 5A, a field oxide film 2 for element separation is grown on a P type silicon substrate 1 by a well-known LOCOS (Local Oxidation of Silicon) method, and then a gate oxide film 3 is formed by thermal oxidation.
Next, after a predetermined area is covered by, for example, a photoresist 30, as shown in FIG. 5B, the gate oxide film 3 in a predetermined area is etched away as shown in FIG. 5C (this forms a predetermined contact part 4).
Next, as shown in FIG. 5D, a polysilicon layer 5 is deposited on the entire face including the contact part 4 by a well-known CVD (Chemical Vapor Deposition) method; and the polysilicon layer 5 is doped by, for example, phosphorus or the like to be N type; and then after a predetermined area is covered by a photoresist 40, a pattern is defined by, for example, a dry etching in order to leave only a predetetermined polysilicon layer 5a (wiring layer) and 5b (gate electrode) as shown in FIG. 5E. At this time, the P type silicon substrate 1 is also etched by patterning to form a recessed part 4a as shown in the figure. The recessed part 4a in the figure is exaggerated to facilitate the understanding as said in the above. Also, 4b in the figure is a connecting region of the polysilicon layer 5a and the P type silicon substrate 1 (that is, an N.sup.+ type diffusion region which will be described later).
Next, as shown in FIG. 5F, the gate oxide film 3 is a predetermined region is etched away except directly below the polysilicon layer 5b, using the above photoresist 40.
Next, a predetermined area is selectively ion implanted with an N type impurity (for example As) 50 and is annealed (thermal treatment) to form N.sup.+ type diffusion region 6 and 7 (source region and drain region) as shown in FIG. 5G; and furthermore, an interlevel insulating layer 8 (a phosphorus glass film such as, for example, PSG (Phosphosilicate Glass or BPG (Borophosphosilicate Glass) is deposited as shown in FIG. 5H.
Below are the problems which are found after variously examining devices obtained by the fabrication process described in the above.
(1) As shown in FIGS. 5G and 5H, in addition to the above recessed part 4a, the above connecting area 4b in the contact part 4 requires a predetermined region (area) in order to secure connection characteristic of the polysilicon layer (wiring layer) 5a and the N.sup.+ type diffusion region (source region) 6. Therefore, device size reduction has naturally a limit, which is disadvantageous to high degree of integration. PA1 (2) With regard to the above FIG. 5B, when the gate oxide film 3 in the predetermined region (the contact part 4 in FIG. 5C) is removed, the other region (where a gate electrode 5b will be formed later) covered with the photoresist 30 as shown in the figure; and because this photoresist 30 is an organic substance, it also contaminates the gate oxide film 3 in the region which should form the gate electrode 5b (this will significantly lower the reliability of devices). Therefore, the gate oxide film 3 needs to be cleaned in the state shown in FIG. 5C by using various cleaning methods, which will also be very disadvantageous in the process. PA1 (3) Furthermore, with regard to the above FIG. 5C, in the contact part 4 with the gate oxide film 3 in the predetermined area being etched away, a natural oxide film is formed because the below lying P type silicon substrate 1 is exposed. In order to stabilize the connecting characteristic of the P type silicon substrate 1 and the polysilicon layer 5 deposited later in FIG. 5D, the above natural oxide film has to be removed by a wet etching or the like with a water solution of, for example, HF (hydrogen fluoride) or the like, just before the polysilicon layer 5 is deposited (this will be, of course, disadvantageous in the process like the above (1)). However, when the natural oxide layer is etched away, the gate oxide film 3 is also etched; and the thickness of the gate oxide film 3 on which the gate electrode 5b should be formed becomes uneven, so that the reliability of the devices is significantly lowered. PA1 (4) As described in the above, in a mask process of the photoresist 40 or the like in FIG. 5E, the contact part 4 has to have a given excess region (area), when considering a contact part 4 wider than the contact area of the polysilicon layer 5a, or an alignment difference, or the like. For example, if the P type silicon substrate 1 is exposed by the above alignment difference or the like, a dry etching or the like etches also the underlying P type silicon substrate 1 (the recessed part 4a), which significantly lowers the reliability of the devices.
A purpose of the invention is to provide semiconductor devices which are highly reliable and permit high degrees of integration, and a fabrication method thereof.

Method of making semiconductor device employing self diffusion of dopant from contact member for augmenting electrical connection to doped region in substrate


The present invention provides a process for forming a solder mask on an electric circuit board without any defects. The process comprises forming an electric circuit on a substrate, coating a negative type photosensitive solder resist on the obtained electric circuit board, and then exposing to light through a negative film followed by developing, characterized in that the negative type photosensitive solder resist is electrodepositable and said coating of the solder resist is conducted by electrocoating the resist on an electroconductive transfer substrate which is different from the electric circuit board and then transferring the coated film onto the electric circuit board.

A printed circuit board is a board on which a copper thin film is patterned as an electric circuit. In order to electrically connect with electric elements, a soldering process wherein the circuit is soldered with the electric elements is necessary. It, however, is very difficult to solder on the fine and complicated electric circuit. Accordingly, it is proposed that the portions not to be soldered are covered with a solder mask which is a protective layer having high heat resistance, and that the portions to be soldered are not covered with the solder mask. The solder masked electric circuit board is directly dipped in a solder bath to connect with the electric elements.
The solder mask is generally formed by coating a negative type photosensitive solder resist on the surface of the circuit board followed by exposing to light though a negative film and developing. The coating process of the negative type photosensitive solder resist is classified into three type, i.e. a printing process, a dry film process and a liquid resist process. In the printing process and the liquid resist process, it is essential to employ a liquid resist, thus the edge (corner) portion of the copper film being not covered with the resist. Also, there may be through-holes present in the electric circuit board, but the liquid resist may flow into the through-holes. In the dry film process wherein a dried film of the photosensitive resist is covered on the electric circuit board, some air spaces are formed between the dried film and the board due to the thickness of the copper film. It may happen that solder invades into the air spaces or that the air in the air space expands to cause blisters. Accordingly, masking effects are not ensured sufficiently also in the dry film process.

Production of solder masked electric circuit boards


A portable card reader designed to be carried in a wallet or purse has an electromagnetic head that reads information from a magnetic strip of a card or information is read from the card by an array of Hall sensors. In a further embodiment, the card reader uses a magnetic sensor based on magnetoresistive sensing of magnetic transitions of a magnetic stripe, suitable for use with small, portable electronic devices. In each embodiment, the information read from the card may be converted to a sequence of electronic bursts of predetermined frequency, preferably in the audible or ultrasound range. The sound signals are output by a speaker to the microphone of a telephone. The signal is then transmitted over the telephone lines to a remote receiver. The receiver then converts the sound bursts into signal pulses, which can be read using the computer software of a conventional card reader.

1. Field of the Invention
The present invention relates to an apparatus for reading information stored on a magnetic strip card and transmitting the data to a remote location. More particularly, the present invention relates to the fabrication of a high resolution, low profile credit card reader, especially for use with a credit card, phone card, or the like.
2. Description of the Related Art
Plastic cards having electronically stored data are widely used to perform a large variety of tasks, from being used as conventional credit, telephone, or bank cards to use as a security key to operate a door lock. Other types of cards are gasoline credit cards, building, room and/or elevator security access cards, personnel cards, Automated Teller Machine (ATM) cards, debit cards and cash cards. For purposes of this application, however, these cards will be generically referenced as xe2x80x9cauthorization cardsxe2x80x9d or just xe2x80x9ccards.xe2x80x9d
Authorization cards fall into three general categories: magnetic, electronic or xe2x80x9csmart cards,xe2x80x9d and passive electronic cards. Confidential information, such as a unique account or card number, is typically stored on the card. In addition, the card number is printed on the face of the card, usually together with other security information such as the owner""s name, the card""s expiration date, and/or a Personal Identification Number (PIN).
In order to complete a given transaction at the point of sale, the card number and/or other confidential information is transmitted from the card to a card reader for recognition and authorization by running the card through the card reader.
Problems arise with the use of conventional inductive read head credit card readers, particularly when they are attached or connected to such devices as personnel computers, laptops, hand held computing devices and cell phones. The prior art inductive read head is not well suited to such small portable electronic devices. The strength of the signal from an inductive head depends on the rate of travel of the magnetic stripe past the gap in the magnetic core of the head. The faster the travel, the larger the voltage induced in the pickup coil of the head. The card must be guided during its motion so that the magnetic stripe is moving in close proximity to (usually in contact with) the pole tips of the head core. The required motion and control is usually obtained by holding or affixing the card reader firmly to a surface and swiping the card through the guide slot. The guide slot is generally longer than the credit card (80 mm) and about 10 mm deep. The size and shape of the device make it difficult to integrate with small portable electronic devices. Also the motion required is sometimes incompatible with the operation of the device. For example, it would be difficult to swipe a credit card through an inductive card reader attached to the side of a cell phone while carrying out voice communication with the merchant.
Fabrication of credit card readers, which typically relies upon photolithography, is also a rather exacting process involving a series of steps. A simpler method of fabrication that does not require lithography would be desirable.
It is therefore a primary object of the present invention to provide a method for fabricating a low profile credit card reader suitable for use with small devices.
It is a further object of the invention to provide a method for fabricating a high resolution magnetoresistive sensor for reading magnetically stored digital information on a credit card without lithography.
It is a further object of the invention to provide a card reader having an output that is independent of the speed of motion of the card with respect to the sensor.
It is a further object to provide a card reader that is less subject to mechanical wear.
It is yet another object of the invention to provide a card reader capable of large voltage signals.
It is another object of the invention to provide a card reader that can operate in conjunction with existing magnetic cards.
It is still another object of the invention to provide a thin profile card reader suitable for small portable electronic devices through the use of magnetoresistive sensing elements.
It is another object of the invention to provide means for reading data stored on an authorization card and sending the data over a telephone to a remote card reader receiver.
It is a further object of the invention to provide a card that generates a sound that is converted to an electronic signal that can be transmitted over a telephone line, and to provide a card reader that is portable and lightweight and can be carried in a pocket, wallet or purse.
In accordance with the above objects, the present invention is a portable card reader that is designed to be carried in a wallet or purse. In a first embodiment, the card reader has an electromagnetic head that reads information from a magnetic strip of a card. In a second embodiment, information is read from the card by an array of Hall sensors. In a further embodiment, the card reader uses a magnetic sensor based on magnetoresistive sensing of magnetic transitions of a magnetic stripe. In each embodiment, the information read from the card may be converted to a sequence of sound bursts of predetermined frequency, preferably in the audible or ultrasound range. The sound signals are output by a speaker to the microphone of a telephone. The signal is then transmitted over the telephone lines to a remote receiver which converts the sound bursts into signal pulses which can be read using the computer software of a conventional card reader.
The present invention is also directed to a method for fabricating a credit card reader that offers both high resolution and low profile. The card reader uses a magnetic sensor based on magnetoresistive sensing of the magnetic transitions of a magnetic stripe.

Fabrication of a high resolution, low profile credit card reader and card reader for transmission of data by sound


A virtual beacon system that provides proximity alerts is described. The proximity alerts are based on the location of a mobile device (100) and a location of interest. The method may include the steps of providing sensor readings for signals, calculating a mobile device location, determining the distance between a mobile device and a product location (202) and generating a proximity trigger (208). A described virtual beacon system includes a monitoring access point (104) for providing sensor readings and transmitting proximity triggers, a location cloud service (106) for calculating a mobile device (100) location and proximity alert service (108) for generating proximity triggers based on the mobile device location.

Proximity beacon support (including, but not restricted to, Bluetooth beacon support) has been added to mobile phone operating systems. Beacons are transmitters that may be located near points of interest. The beacons allow passing receivers to be notified that they are near those points of interest. The beacons may be fixed or mobile depending on the application.
Proximity beacon support is available to mobile app developers through APIs (application programming interfaces) for region monitoring and proximity ranging. Region monitoring enables mobile apps to register proximity triggers that call back when the mobile operating system detects a particular beacon is within range of the mobile device. Ranging enables the measurement of the mobile device's proximity to that beacon. Mobile applications that have exited or are paused in the background can be awoken by the operating system's region monitoring function to perform actions that are relevant to the phone being near a particular location. These actions include providing special offers or other notices of nearby products or attractions, triggering analytical or audit functions, such as to record the presence of a device in a secure part of a research facility, or to enable of disable functions such as wireless access for phones being used in the vicinity of a driver's seat in a car.
There are a number of problems associated with proximity beacon systems. One problem is that that the beacons themselves can be inconsistent in triggering region monitoring events. Additionally, the "beacon based ranging" used to estimate location can be inaccurate. The ranging functions rely on techniques such as received signal strength indication (RSSI), which are very susceptible to interference, signal attenuation and multipath effects. These inaccuracies become compounded; so the further the mobile device is from a beacon the less accurate the proximity measurement is. In addition, the cost of purchasing the large numbers of beacons in a venue can become onerous and the cost of the labor to deploy and maintain the beacons, including replacing batteries periodically, can become prohibitive. This restricts the number of beacons that can be economically deployed.
Lastly, the operation of ranging functions tends to consume a significant amount of power based on much more intense use of the radio used to monitor the beacons. This depletes the life of the mobile device's battery. Thus, there is a need for a method and apparatus for delivery location based alerts without the use of proximity beacons.


A length artifact has a first side wall, a second side wall, and a base portion, the first side wall and the second side wall separated by an air gap at least four millimeters wide, the base portion being attached to a bottom of the first side wall and the second side wall, the base portion further having a first platform region that includes a first nest and a second platform region that includes a second nest, the first nest and the second nest configured to accept a spherical surface of a retroreflector target.

The present disclosure relates to a length artifact to determine the measurement errors associated with a three-dimensional (3D) measurement instrument and with methods of measurement using the length artifact.
Portable metrology instruments, such as portable laser trackers and articulated arm coordinate measuring machines (AACMMs), find widespread use in the manufacturing or production of parts where there is a need to rapidly and accurately verify the dimensions of the parts during various stages of the manufacturing or production (e.g., machining). Portable metrology instruments represent an improvement over known stationary or fixed, cost-intensive and relatively difficult to use measurement installations, particularly in the amount of time it takes to perform dimensional measurements of relatively complex parts.
A laser tracker is in a class of instruments that measure coordinates of a point by sending a beam of light to the point. The beam of light may impinge on a retroreflector target in contact with the point. The laser tracker determines the coordinates of the point by measuring the distance and the two angles to the target. The distance is measured with a distance-measuring device such as an absolute distance meter (ADM) or an interferometer. The angles are measured with an angle-measuring device such as an angular encoder. A gimbaled beam-steering mechanism within the instrument directs the laser beam to the point of interest. A related instrument is a total station (tachymeter) that measures to either a retroreflector or a point on a diffusely scattering surface. Laser trackers, which typically have accuracies on the order of a thousandth of an inch and as good as one or two micrometers under certain circumstances, are usually much more accurate than total stations. The broad definition of laser tracker, which includes total stations, is used through this application.
Ordinarily the laser tracker sends a laser beam to a retroreflector target. A common type of retroreflector target is the spherically mounted retroreflector (SMR), which comprises a cube-corner retroreflector embedded within a metal sphere. The cube-corner retroreflector comprises three mutually perpendicular mirrors. The vertex, which is the common point of intersection of the three mirrors, is located at the center of the sphere. Because of this placement of the cube corner within the sphere, the perpendicular distance from the vertex to any surface on which the SMR rests remains constant, even as the SMR is rotated. Consequently, the laser tracker can measure the 3D coordinates of a surface by following the position of an SMR as it is moved over the surface. Stating this another way, the laser tracker needs to measure only three degrees of freedom (one radial distance and two angles) to fully characterize the 3D coordinates of a surface.
Periodically it is desirable to evaluate the performance of a 3D measuring instrument. One way to do this is to measure a length artifact, also known as a length standard or a reference length, and to compare a length of the artifact as obtained from a calibration to the length as obtained from a measurement with the 3D measuring instrument. The difference between the measured and calibrated length values is the error, which is an indicator of performance of the 3D measuring instrument. Today, there is a need for a length artifact that is stable, easily calibrated, and easily measured with a 3D measuring instrument such as a laser tracker, articulated arm CMM, or similar device.
Accordingly, while existing length artifacts are suitable for their intended purposes, the need for improvement remains, particularly in providing an improved length artifact and method of measuring with a 3D measuring device.

Length artifact and method of measurement


A method apparatus for determining the length of a roll of sheet material, including a side surface at which the edge of each of the plurality of layers of sheet material is exposed wherein the side surface of the roll of sheet material is exposed to a source of radiation and the radiation reflected from the edges of the roll is scanned in a radial direction to establish a first signal indicative of the reflected radiation and the number of edges of layers of sheet material. The length of the roll of sheet material is calculated using the sensed number of layers of sheet material in the roll. The method and apparatus are similarly adapted to determine the number of layers of sheet material in a stack of sheet material.

Sheet material, such as sheet steel which is sold in a coiled roll, is sold by the pound. The length of the roll of material is calculated using the density of the steel, roll weight and gauge. Variations in the nominal gauge of the steel lead to unacceptable errors in length calculations. It has been found, for example, that 0.26 gauge galvanized sheet steel varies in thickness between 0.0187 and 0.0247, and 30 gauge galvanized sheet steel varies between 0.0127 and 0.0187. These variations in thickness provide unacceptable errors in the present way in which the length is calculated. For example, due to non-uniformity in the thickness of the steel, a 5 on roll of 48" width 28 gauge galvanized steel can vary in length between 3,808 feet and 4,864 feet. Thus, there can be a considerable difference in the length of two like gauge and like weight rolls of steel. Coiled rolls of sheet metal are bought by the pound and then the sheet metal is used by the square foot to manufacture various products. Difference in the length of the rolls is critical in the use of the sheet metal in calculating the cost of items manufactured from the sheet material.


A circuit board is wave soldered as it is carried by a conveyor through a solder wave established in a solder reservoir. Disposed on both sides of the solder wave are gas plenums which discharge shield gas. The gas plenums include orifices for directing shield gas (i) at high velocity toward the solder wave to protect the solder wave with an atmosphere of shield gas, and/or (ii) upwardly toward an underside of the circuit board to strip entrained air therefrom. The solder wave is generated by a pump driven by a drive shaft that extends downwardly into the solder reservoir. An upper portion of the drive shaft is surrounded by a stationary hollow sleeve which projects into the solder reservoir to restrict the churning of the solder during rotation of the drive shaft. A shield gas is introduced into the sleeve to inert the solder being churned. An enclosure is positioned above the solder reservoir having an inlet and an outlet through which the circuit boards are conveyed. Curtains are positioned across portions of the inlet and outlet not occupied by the conveyor, the curtains being automatically adjusted when the width of the conveyor is adjusted.

The present invention relates to methods and apparatus for providing a non-oxidizing atmosphere at the surface of a wave soldering bath to discourage the formation of oxides on the liquid solder surfaces.
Wave soldering machines have been introduced for a long time in the industry to automatically solder components on a printed circuit board which operation was previously done by hand. A usual wave soldering machine comprises at least one preheating zone to preheat the printed circuit board, at least one soldering zone to solder the components to the board by coating the bottom side of the printed circuit board with molten solder contained in a solder pot, and at least one cooling zone where the solder is solidified. This soldering process, or coating process, is usually conducted in the presence of a fluxing agent which agent is used to improve the wetting of the copper surface on the bottom of the printed circuit board which surface needs to be joined or coated. The fluxing agents are usually corrosive and the excess or residue of these agents must be cleaned after the wave soldering operation.
Low residue no-clean fluxes or flux-less processes have been developed wherein it is possible to carry out the wave soldering process without the inconvenience of standard fluxing agents, under a substantially oxygen-free atmosphere, such as nitrogen.
U.S. Pat. No. 3,705,457 discloses one of the earliest wave soldering processes, including injection of an inert gas to avoid oxidation of the metallic surfaces of the printed circuit board.
U.S. Pat. No. 4,538,757 discloses a wave soldering process under a reducing atmosphere comprising nitrogen and hydrogen, and nitrogen curtains at entrance and exit of the machine to inhibit atmosphere exchange with the ambient air.
U.S. Pat. No. 4,606,493 discloses a method and apparatus for soldering printed circuit boards under an inert gas atmosphere to prevent oxidation of the electrical (usually copper) connections due to the heat produced during soldering and reduce the occurrence of thermal stress defects in the circuit carrier. To this end, an inert gas is injected through slits to provide a plurality of jets of high velocity which impinge the bottom side of the printed circuit board. As a condition of operation, the temperature of the inert gas jets is about twice as high as the temperature of the molten solder in the solder pot (600.degree. C.).
U.S. Pat. No. 4,646,958 discloses a solder reflow, or solder chip process which is carried out in a flux-less or flux free system, under an atmosphere comprising nitrogen and saline, or hydrogen and saline.
U.S. Pat. No. 4,821,947 discloses a process to coat a molten metal to a metal-comprising surface without using a flux. This process is carried out in an inert atmosphere in which the temperature is sufficiently low that no damage is done to the metal-comprising surface, and no damage is done to materials such as components adjacent to the metal-comprising surface.
U.S. Pat. No. 5,071,058 discloses a process for conducting a joining/coating operation which is carried out in a controlled oxidizing atmosphere, having an oxidation capability greater than that required to oxidize a metal-comprising filler material used for joining or coating, but having less oxidation capability than that of air. In case of a wave soldering process the oxygen content in the inert gas atmosphere is at least 10 ppm and preferably at least 500 ppm.
U.S. Pat. No. 5,121,875 discloses a short hood for wave soldering machines, wherein preheating of the printed circuit boards is carried out under air. In this process a no-clean flux is used and an oxygen concentration which is less than 5% is recommended at the solder pot.
U.S. Pat. No. 4,921,156 discloses an apparatus having a soldering chamber and comprising means to inject a protective gaseous atmosphere in the soldering chamber and sealing skirt means protruding downwardly into the pool of molten metal solder. Preferably the protective gaseous atmosphere is comprised of nitrogen and possibly of some reducing agent.
U.S. Pat. No. 4,746,289 discloses a process for treating parts under a non-reactive atmosphere with laminar flow conditions. The laminar flow conditions disclosed in this patent usually apply for inert gas injection in wave soldering machines.
In sum, a substantially oxygen-free atmosphere has been achieved by a so-called fully inerted wave soldering system, and a dross reduction boundary system.
The fully inerted wave soldering systems currently uses a tunnel type of system. That type of system is very expensive and time-consuming to install. Because this type of machine uses a tunnel, the access to the assemblies being soldered is greatly reduced. To achieve the desired results that type of system must operate at very high gas flow rates (over 1500 scfh). By doing this, the oxygen ppm level in the inerting system is kept low, thus yielding the desired results. If the flow rate is reduced, the atmosphere becomes unstable and benefits are lost. The primary goal of the fully inerted system is keep the oxygen ppm level below approximately 100 ppm. This then would yield the maximum dross reduction with the greater wettability for soldering.
The dross reduction boundary inerting system was developed to address the problems of the fully inerted system. The design was such that it can be easily installed and is much lower in cost. The other goal of this system was to have a reduced inerting gas flow rate. While those goals appear to have been met, the performance of that system is greatly reduced as compared to that of the fully inerted system. Because the boundary inerting system depends on a circuit board being present for the inerting to take place, the actual inerting effect is never fully achieved. The dross reduction of such a system is typically at best 70% (with reference to a solder pot operating without an inerting gas) with only marginal if any improvements in wettability.
Examples of a dross reduction boundary inerting system can be found in U.S. Pat. Nos. 5,203,489 and 5,240,169. There is disclosed therein a system in which solder waves are established by wave pumps in a solder reservoir. A conveyor transports circuit boards so that their undersides pass through the solder waves. As depicted in FIG. 10, a cover plate C extends across the top of the reservoir R and includes recesses to accommodate the solder waves. On the sides of each solder wave there is thus formed a chamber CH bordered on its top by the cover, on its bottom by the solder reservoir, one side by the solder wave, and on an opposite side by either (i) a stationary wall (of the solder pot or solder pot housing), or (ii) another solder wave (in the case where the chamber is situated between two solder waves). Each chamber includes a gas outlet defined by a gap G formed between the solder wave SW and an edge of the cover slot.
Disposed within each chamber is a gas discharge pipe P extending parallel to the length of the solder wave. A shield gas is discharged from orifices in the gas discharge pipe to create an inert atmosphere within the chamber CH. A flow F of shield gas exits the chamber through the outlet. That gas flow is intended to provide an inert blanket across the portion of the wave side which projects above the gap G when a circuit board is present. However, when no circuit board is present, the portion TS of the top surface of the wave which curves away from the gap G is exposed to any ambient oxygen which may be present in the ambient atmosphere, whereupon dross can be formed. In the case of soldering operations in which there occurs a wide spacial gap between successive circuit boards being conveyed to the solder pot, it is not unusual for the solder wave pumps to be deactivated between the soldering of successive boards in order to minimize dross formation.
Furthermore, the behavior of the gas flow F emerging from the chamber can actually promote the formation of dross on the solder wave. In that regard, the pressure difference between the gas in the discharge pipe on the one hand and the atmosphere disposed above the chamber outlet, on the other hand, is relatively low. As a result, the velocity of the gas traveling within the chamber toward the outlet is relatively slow. Due to its slow travel, the gas will be significantly heated by the hot solder wave. Consequently, the hot gas flow F emerging from the gap G has a tendency to rapidly rise and create a free swirling convection current CC which draws the cooler atmosphere (and any oxygen contained therein) downwardly toward the solder wave, thus resulting in the formation of dross.
Another region in which dross is formed in the solder is at the place where the drive shafts for the wave pumps enter the solder reservoir. The rotation of those shafts produces a churning of the solder, whereby oxidation is promoted.
It will be appreciated that the dross formed in the solder eventually builds up to a level requiring that the solder pot be shut-down to enable the dross to be skimmed off the top of the solder reservoir. The frequency at which those costly shut-downs occur is a function of the rate of dross formation.
Therefore, it would be desirable to minimize the rate of dross formation beyond the rates currently achieved.

Process and apparatus for the wave soldering of circuit boards


A clock recovery network uses a voltage proportional to the incoming symbol rate as a coarse tuning signal to control the tuned center frequency of a voltage controlled oscillator. The incoming data is used to positively synchronize the oscillator to the incoming data stream.

In conventional modems, the clock recovery network has been designed to operate at high frequencies, e.g., above 10 MHz, or low frequencies. The high frequency clock recovery networks have proven quite acceptable but typically utilize delay elements. To operate these high frequency clock recovery circuits at lower frequencies requires that larger delay elements be utilized, and below approximately 10 MHz the required size of the delay element becomes unacceptable. For this reason, separate clock recovery networks have been designed for low frequency systems, these low frequency clock recovery networks typically incorporating phase lock loops with multiple control elements whose repeated adjustments become tedious and are often impractical.
In order to overcome this difficulty, I have invented a clock recovery network which is effectively useful at both low and high frequencies, and I have disclosed such a clock recovery network in my co-pending and concurrently filed application Ser. No. 79,654 entitled Clock Recovery For QPSK Modems and assigned to the same assignee as the present application. This co-pending application is incorporated herein by reference as if fully and completely repeated hereinbelow.
The present invention is an improvement in the clock recovery network disclosed in my co-pending application, and is directed to the use of such a clock recovery network in a universal modem. In present modems, the clock recovery network is designed to operate only at a single frequency, and in order to accomodate different bit rates, the clock recovery network must be replaced. Even in the clock recovery network disclosed in my co-pending application, the Synchronized Voltage Control Oscillator (SVCO) is tuned to a center frequency in the vicinity of the clock frequency to be recovered, and the incoming data stream is then used to positively synchronize the oscillator with the incoming data. If a different bit rate is to be employed, the oscillator would have to be replaced with a different oscillator tuned to a different center frequency. This requirement of replacing the clock recovery network in order to accomodate different bit rates can be quite troublesome in a universal modem which may be operated frequently at different bit rates.

Universal clock recovery network for QPSK modems


A sewage aeration system comprising a header pipe, plenums of synthetic thermoplastic or thermoset resin with side walls inclined upwardly and outwardly to diffusion element support means, generally horizontal diffusion elements free of through-holes other than air diffusion pores, retaining means securing the elements about their peripheries to the plenums, sealing means adjacent the peripheries of the diffusion elements and airflow regulator members which terminate in the plenums beneath the horizontal diffusion elements.

Heretofore a variety of designs have been proposed for sewage aeration systems comprising a header pipe, a holder, a porous diffusion element, means for retaining the diffusion element in the holder, sealing means and air flow regulator means. Examples may be found for instance in U.S. Pat. Nos. 2,346,367, 3,083,953, 3,532,272, 3,733,064, 3,970,731 and 4,007,240.
Experience with commercially available sewage aeration systems of the above mentioned type, as well as careful study and experimentation, have shown that such systems suffer from one or more shortcomings alone or in combination. Among these are tendencies to produce excessive quantities of large bubbles, with resultant impairment of oxygen transfer efficiency; expense and complexity of system components; complexity and labor costs associated with field installation; a certain tendency to cause breakage of diffusion elements during installation; lack of uniformity of distribution among diffusion elements; lack of uniformity in the distribution of air flow across individual diffusion elements; and other difficulties. The purpose of the present invention is to reduce or eliminate these difficulties and provide an improved sewage aeration system.


A tribosystem for radial and axial foil bearings includes a first structural component part; and a second structural component part interacting with the first part. The first and second parts are in a dry frictional unidirectional sliding contact with one another until an air film is formed. A surface of at least one of the first and second parts being exposed to the dry frictional contact contains at least partly at least one of a metallic bound (Ti,Mo)(C,N), Tin-2Cr2O2n-1 with 6≦n≦9 and solid solution of TiO2—Cr2O3.

Leaf- or bump-type foil air bearings are self-acting, compliant surface bearings. When in operation, they support load on an air film. Benefits of foil air bearings include reduced cost, higher speed, lower weight, higher efficiency and greater accommodation for misalignment and distortion. During start-up and shutdown, however, unlubricated dry high-speed sliding contact occurs between e.g. the shaft and foil surfaces, causing wear, until the air film was formed. The lift-off speeds depend from design and diameter, but range typically from 8 m/s to 15 m/s. A wear resistant coating is therefore required for durable, long-term operation. They accumulate up to 100,000 starts and stops.
The foils thicknesses are below 200 μm and a wear loss of 25% of this thickness is only tolerable otherwise the damping characteristics change. Additional, the use of coated shafts in air foil bearings is considered to be necessary, since special shaft super-alloys like, INX-750, René41, INC909 or MA956 tend at 800° C. to adhesive (Literature 1) material transfer, when sliding unlubricated against INX-750.
The substitution of chromium carbide (U.S. Pat. No. 5,034,187) in the NASA PS200-series self-lubricating coating based on 30%-70% chromium carbide, 5%-20% soft and nobles (Ag) metals, 5%-20% fluorides and 20%-60% metallic binder by chromium oxides leading to the NASA PS300 series (U.S. Pat. No. 5,866,518) generic composed of 60-80% Cr2O3, fluoride of gr. I and II, Ag, Au, Pt, Pd, Rh or Cu and NiCr binder seems to be motivated by cost and process aspects. The porosity of a sintered PM212 was 22% by volume. The NASA-series PS302 to PS321 present a binder rich (41-60 wt.-% of NiCr, ˜METCO 443) concept.
The use of solid lubricant coatings composed of 20-23% BaF2+13-15% CaF2+33-38% Cr2O3+25-33% Ag in a heat resistant Ni-binder (23, 5Ni17Co12, 5Cr0, 5Al) was first presented by S. Niizeki et al. in literature 3, S. Niizeki, T. Yoshioka, H. Mizutani, H. Toyota, T. Hashimoto, Development of solid lubricants for high temperature rolling ceramic bearings (part I): Various solid lubricants based on fluorid compounds, Japanese Journal of Tribology, Vol. 40, No. 12, 1995, S. 1277-1287.
The wear rates for the couple INX-750/PS304 at 25° C. and 500° C. in a narrow range of 1.6-2.4 10−4 mm3/Nm were measured in the trust-washer rig under P×V-values of 0.11-0.22 MPa×m/s by NASA.
The PV factor or P×V value is the product of bearing pressure and surface velocity traditionally expressed in (lb/in2)×(ft/min) or in the ISO equivalent in Pa×m/s. It characterizes the mechanical input in a sliding bearing as severity of design or the maximum mechanical input that the tribomaterials can support. The term μPV is equivalent to the heat generated in W/mm2. It describes a barrier between low wear and high wear regimes. As well as the upper value of a load-bearing materials PV product above which a material fails to function satisfactorily. High PV-values mean high load capacities of the bearing.
The world wide used wear rate or wear coefficient in [mm3/Nm] describes the wear expectation of a couple under certain operating conditions, but is not a material property. It is defined as the ratio of the wear volume divided by the acting normal force and effective sliding distance.
For definition of wear rate and PV-value, please see: ASM handbook "Friction, Lubrication and Wear Technology, volume 18, October 1992, ISBN 0-87170-380-7 or
ASTM G40-01 "Standard Terminology Relating to Wear and Erosion".
U.S. Pat. No. 5,370,719 is directed to cutting inserts and displays results from milling test. They form open tribosystems. Since the normal load on the cutting edge is unknown, wear rates cannot be calculated using the wear scar width.
The patent application DE Patent No. 195 30 517 discloses also a monophasic coating composed of (Ti,Mo)(C,N) deposited on steel for cutting tools. In the common understanding of metallurgist is "steel" distinct from a super alloy based on nickel or cobalt.
The patent applications related to titanium carbonitride or titanium-molybdenum carbonitride cermets cover cutting tool inserts. Cutting tools form an open tribosystems, where the cutting tool interacts continuously with the working peace, which itself enters into contact mainly or only one time. The working peace consists consequently not of the cermets.
The foil bearing itself represents a closed tribosystems composed of two periodically interacting surfaces, which is distinct different from an open one.
DE Patent No. 195 48 718 discloses lubricious oxide (LO) coatings for the tribological stressed surfaces in liquid lubricated internal combustion engines. The LO can be deposited as coatings or form LO by tribooxidation on substrates, like (Ti,Mo)(C,N). The type of binder is not mentioned. The LOs aim to substitute extreme pressure (ep) and anti-wear (aw) additives as well as polymeric viscosity index improvers in liquid lubricants (engine oils). In consequence, these LOs run under mixed/boundary and/or hydrodynamic liquid lubrication and not under dry friction (unlubricated) or at high temperatures as in the foil bearing.
U.S. Pat. No. 6,020,072 and U.S. Pat. No. 6,017,592 disclose a dry running hinge joints for aerospace applications up to 1600° C., which operate obviously at low speeds (v<0.5 m/s) and are unable to form an aerodynamic film. Tribooxidation or static oxidation form soft reaction layers on specific materials, like (TiMo)(C,N), typically Magnélli-type phases as substoichiometric oxides forming distinct planar oxygen defects. The type of binder for use as thermal sprayed coating is not mentioned. The substrates are made of SiC, HfC and C-SiC composites. The first and second component forming the closed tribosystem (hinge joint) use the coatings disclosed in these patent applications. As coating, also Tin-2Cr2O2n-1 is disclosed without any data about the tribological behavior for sliding velocities above 1 m/s.
US Patent Published Application No. US2004/113520 disclose (Ti,Mo)(C,N)+8-20% Ni/Mo-binders (TM 8, 10, 20 grades of Sandvik Hard Materials) for piezoelectric high-power or vibration motors. The tribosystems in these motors perform by nature a linear, oscillating motion with strokes below 15 μm at oscillating frequencies of 20-40 kHz. The significant differences to foil bearings are the 1.000 times greater generation of frictional heat during dry sliding of foils and the fact of needing coefficient of friction greater than 0.5. The piezomotor is unable to form an aerodynamic film.
DE Patent No. 196 40 789 discloses coatings for liquid lubricated piston rings in internal combustion engines composed of 50-95% by volume (Ti,Mo)(C,N) hard phase with Ni,Co,Fe-binders, which were as example deposited using powders composed of 59.6 weight-% TiC0.7N0.3, 12.0 weight-% Mo2C and 28.4 weight-% Ni.
The results in L.-M. Berger et al "Hartmetallähnliche Schichten gegen Verschleiβ and Korrosion", Maschinenmarkt No. 8, 1996, for abrasion resistance tests according to ASTM G65-85 or of erosion tests with an open tribosystem of cermets and hard metals can't be transferred to the air foil bearing, as no third bodies (abrasives) are welcome or abrasives will impact in bearing surfaces in a aerodynamic foil bearing and of course are not there present, since particle in the size of the air film will cause damage and block the tribosystem.
The results of Skopp, A. and M. Woydt "Ceramic and Ceramic Composite Materials with Improved Friction and Wear Properties", Tribology Transactions, Vol. 38(2), 1995, p. 233-242 of the unlubricated tribological behaviour in air of self-mated TM10 (RPK of smooth rotating disks ˜0.025 μm) sliding couples up to 800° C. and 3.68 m/s can't be taken into consideration, as they were achieved using a monolithic (Ti,Mo)(C,N) with a binder composed of 13% by weight of nickel and 2% by weight of molybdenum.
Magnélli-type phases of (Ti,V)nO2n-1 or (W,Mo)nO3n-1 are unsuited for temperatures in air above 400-450° C. as they reoxidize to the stoichiometric composition. This can be overcomed by the use of Tin-2Cr2O2n-1, with 6≦n≦9, which is oxidatively stable up to 1000° C. and above.
The state-of-the-art for sliding materials for foil bearings, especially established by the PS30x-coatings, disclose wear rates limited to 10−5 mm3/Nm.

Tribomaterials for axial and radial foil bearings