Selected U.S. Patent Abstracts

Abstract: A voltage controlled oscillator (VCO) operating as a variable length, variable delay, ring oscillator having a current starved inverter and an anti high-gain circuit for each stage. A VCO feedback signal is compared with a reference frequency obtained, for example, from a system crystal oscillator. A phase and frequency detector monitors these two input signals and issues "up" or "down" commands to a digital counter. This digital counter delivers select signals via a decoder and also drives a Digital to Analog Converter ("DAC"). The digital select signal from the counter chooses an operational stage from the multi-stage, tandem-connected VCO. A broadband operation for the VCO is achieved by overlapping the individual frequency ranges associated with each of the individual stages. The DAC moves the operation along each selected frequency range associated with a selected stage until a system lock between the VCO output and the crystal references is achieved.

Abstract: An electronic switch to be used in BiCMOS circuitry when CMOS stages are controlled by logic output from (bipolar) TTL stages. Its purpose is to avoid the static leakage current I(cct) which can occur in a CMOS stage when the pulldown transistor is turned on while the pullup transistor is not completely turned off. This is a problem which arises when CMOS and TTL stages are coupled; the logic-high output from a TTL stage is sufficient in magnitude to turn on the CMOS pulldown transistor but not to turn off the CMOS pullup transistor. The present invention introduces an ancillary input to the subcircuit encompassing the CMOS input stage and also an ancillary output from one of the CMOS stages of the subcircuit (typically an output buffer) encompassing the TTL output stage. The ancillary output is chosen so as to provide a CMOS logic-high signal whenever the TTL stage is outputting a TTL logic-high signal. The ancillary input is connected to the control node of a switching transistor interposed between V(cc) and the CMOS input stage's pullup transistor. In this manner, the source of I(cct) is interrupted immediately after the CMOS stage is switched from pull-up mode to pull-down mode. The invention has particular applicability to latched transceivers, where the CMOS input stage is located in the latch circuit and the TTL in the tristate output buffer circuit.

Abstract: A collet-and-shank assembly for gripping a work piece or tool used in rotary cutting equipment. The assembly includes a dual-threaded nut that enables the machine operator to lock and release the device from a single end. The dual-threaded nut is completely recessed within the shank, thereby reducing the overall length of the assembly and increasing the available working space. In the preferred embodiment of the collet-and-shank assembly, the dual-threaded nut has an interior right-hand threading corresponding to the outside threading of a section of the collet. The exterior of the dual-threaded nut has a threading orientation opposite to that of the interior region, corresponding to the threading of an interior section of the shank. When the exterior of the dual-threaded nut is threaded into the shank and the collet is threaded into the interior of the dual-threaded nut, the collet is affixed to the shank, and the work piece or tool is also locked within the collet. Utilization of fixed inside shank and outside collet dimensions where the dual-threaded nut joins the two eliminates the need to provide a supplemental adapter when, for example, a small tool or work piece must be used in a large turret or spindle hole.

Abstract: A relief printing technique wherein the material to be printed on is placed between an inked relief and a supporting assembly comprising a dressing web and a second relief reproducing the pattern of the printing relief.

Abstract: A towable road tender device for grading unpaved roadway surfaces. The tender device may be hitched to commercial vehicles but is particularly suited for use with private vehicles, such as small tractors and pickup trucks. A set of relatively lightweight frames reduce the weight to be pulled by the vehicle. The towable road tender device is sized to be operated using small-scale power take-off units commonly available in private vehicles, such as, for example, the power units of conventional front-end plows. The set of lightweight frames includes a support frame that secures the tending tool, a wheel frame that pivots the rear towing wheels either toward or away from the support frame, and an attachment frame joining the other two frames to a hitch on the towing vehicle. The attachment frame is designed to keep the support frame parallel to the plane of the underlying roadway surface as that support frame is raised or lowered. The height differential between the hitch of the towing vehicle and the support frame normally results in a lifting of the front of the support frame and a reduction in the bearing weight of the tending tool on the roadway surface. The attachment frame of the present invention eliminates this problem by pivoting upward when the tending tool is lowered down to the roadway surface. This pivoting not only eliminates the lifting, it enhances the bearing capacity of that tool.

Abstract: A changeable grid system kit for constructing three-dimensional toy and scale model designs, including a base component fabricated of a tough, resilient material, slots formed in the top face of the base, and slats which are insertable into the slots. The invention is designed to ensure that there is little or no loss in the tight fit between the slats and the base material after repeated insertion and removal of the slats. The base material is selected so as to avoid fracturing or splintering caused by repeated use or incidental contact. One such material is a closed-cell crosslinked polyethylene foam. In one embodiment of the invention, the base component is placed vertically such that the slats extend from the slots to form quasi-horizontal surfaces. In this orientation the present invention may be used as an educational tool to illustrate such physical principles as gravity, friction, and the like. A ball may be rolled down pathways created by insertion of the slats into the slots in a variety of configurations, thereby illustrating the principles noted and encouraging experimentation by the student.

Abstract: An improved Schottky diode structure (4) is formed by retrograde diffusing an N(^+) concentration of relatively fast diffusing atoms, preferably Phosphorus atoms, to form a localized diode NWell (6) as the diode substrate for the diode. A buried diode layer (5) formed of relatively slow diffusing N type atoms, preferably Antimony atoms, underlies the diode NWell and electrically couples the diode junction (7) to the diode ohmic contact (9). A diode ohmic contact region (31) underlies the ohmic contact, further coupling the diode junction to the ohmic contact. Preferably, the diode junction is a Platinum-Silicide junction. The improved Schottky diode structure may be formed as part of a BICMOS integrated circuit fabrication process wherein the buried diode layer may be formed at the same time as a buried collector layer of a bipolar transistor structure, the diode NWell may be formed at the same time as an NWell of a CMOS transistor structure and the diode ohmic contact region may be formed at the same time as a collector sink region. In the BICMOS fabrication process the buried collector layer definition mask is also a buried diode layer definition mask, the retro NWell definition mask is also a diode NWell definition mask, the collector sink definition mask is also a diode ohmic contact region definition mask, and the BICMOS contacts definition mask is also a diode junction and ohmic contact definition mask.

Abstract: A circuit to be used with tristate output buffers as a means of diverting from the output pulldown transistor control nodes Miller Current arising while the output buffer is being switched from the low-active state L to the inactive state Z. The circuit complements a DC Miller Killer circuit, relieving the latter from having to deal with this transient, and hence permitting a down-sizing of the DCMK transistor. The net effect is a significantly faster L.fwdarw.Z transition for the tristate buffer and a slightly faster Z.fwdarw.L transition, all accomplished without degrading the DC Miller Killer protection against L.fwdarw.H bus transitions.

The key to the present invention is its use of the time interval between the respective, sequential switching of the enable buffer outputs, E and EB following the application of a disable signal to this enable buffer. The present invention includes circuitry which ensures that its Miller Killer transistor is conducting only during the transient associated with the L.fwdarw.Z switching. One embodiment for accomplishing this is to connect the control node of an "LZ/ACMK" transistor to the high-potential power rail through two control transistors wired in series. Then, by arranging the circuitry so that both control transistors are conducting only when E and EB are both logic-low, a situation which arises only in the midst of a transition of the output buffer into its Z state, the desired AC operation of the present Miller Killer is achieved.

Abstract: This invention relates to an improvement in an apparatus for directing the flow of water from the penstock to the vanes of a hydraulic turbine, generally referred to as a wicket gate, and a method for making the improved wicket gate. The improved wicket gate comprises a rotatable planar body made either of a high-strength plastic material or metal, onto which a viscoelastic material is affixed. The improvement lies in the application of the viscoelastic material to the rotatable planar body in such a way that the viscoelastic material becomes an integral component of the rotatable planar body. This improvement extends the maintenance life cycle by reducing marine growth, erosion and pitting caused by cavitation.

Abstract: A circuit to be used with bistate and tristate output buffers as a means of diverting from the output pulldown transistor Miller Current arising while the output buffer is powered down. Its purpose is to avoid loading the common bus to which the output buffer is attached, in particular under the circumstances where other output buffers on the bus are causing transitions to occur and the buffer of interest has been powered down. In its preferred embodiment the invention utilizes a MOS transistor coupled between the output pulldown transistor and the lower potential power rail of the output buffer. This MOS transistor is controlled by another MOS transistor coupled to output V(OUT) of the buffers. This driver transistor is controlled by the high potential power rail of the buffer and so turns on the Miller Current Discharge Transistor only when the buffer is powered down. The invention also encompasses a discharge transistor coupled to the data input V(IN) to ensure that the Miller Current Discharge Transistor never pulls the of the output pulldown when the buffer is in its active low state.

Abstract: A photodetection system and related circuitry designed to sense the intrusion of an opaque object in a light plane. Upon sensing the intrusion, the system quickly initiates a machine-stopping sequence prior to the opaque object coming into contact with the machine while that machine is operating. The system comprises a SYSTEM microcontroller and a WATCHDOG microcontroller, both of which operate an output control device of the light curtain switch of the invention, wherein the output control device comprises a plurality of electromechanical relays. Both microcontrollers also perform system hardware and software integrity checks. Furthermore, the WATCHDOG microcontroller evaluates the performance of the SYSTEM microcontroller by transmitting a false intrusion signal to a photosource, determining whether the false signal has been detected, and then verifying that the SYSTEM microcontroller has initiated the machine-stopping sequence. The machine-stopping sequence may be overridden by the WATCHDOG microcontroller, or it may be initiated if the false signal is not detected. The combination of electronic, mechanical, and optical modules of the present invention provides improved reliability and accuracy. In addition, the SYSTEM microcontroller and the WATCHDOG microcontroller are designed so as to reduce the system's sensitivity to spurious signals.

Abstract: An interconnection system for connecting leadless grid arrays of integrated circuits with leadless grid arrays of printed circuit boards. The system includes an insulative socket, flexible conductive elements and a compression lid. The insulative socket is temporarily affixed to the printed circuit board as the conductive elements, retained on a flexible carrier, are inserted into cavities of the socket. The cavities of the socket have inside dimensions greater than the outside dimensions of the conductive elements. After the conductive elements have been affixed to the printed circuit board, the flexible carrier is taken off of the elements and the insulative socket may be removed for visual inspection of the connection between the contact pads of the circuit board and the conductive elements. The integrated circuit is placed on top of the conductive elements such that contact pads of the circuit are properly aligned with appropriate contact pads of the printed circuit board. The compression lid is placed over the integrated circuit and affixed to the printed circuit board so as to secure the contact pads of the integrated circuit to the conductive elements.

Abstract: A device for marking cutaneous landmarks as a means of identifying under x-radiography pathological deep structures of the small bones of the foot that comprises affixing a radiopaque material to an adhesive tape and placing the radiopaque material over a cutaneous landmark on a patient's foot and then x-raying the highlighted area. The radiopaque material is formed into any one of a variety of shapes, such as a circle, triangle or square, so as to provide a marker that completely encompasses the cutaneous landmark. A series of such markers is affixed to a roll of tape with an adhesive backing, or provided in pre-cut form, for ease of dispensation and attachment to the patient's foot.

Abstract: A circuit for use in connection with tristate output buffers in order to provide concurrently for fast discharge of the output pulldown transistor base and at the same time for building in protection against reverse breakdown in the pulldown transistor. The innovation consists of providing a two discharge paths to ground for the base of the output pullup transistor. A low-capacitance path is activated only while the output buffer is in its active mode. In the preferred embodiment of the invention, this low discharge path consists of two CMOS transistors in series, one of which is controlled by the enable signal input E of the buffer circuit and the other by the data signal input V(IN) of the buffer circuit. The other path to ground is available whenever the data signal input V(IN) is low, regardless of whether the buffer is in its active or inactive mode. This other path provides discharge protection for the base of the pullup transistor for the buffer in its inactive mode, and has incorporated into it reverse breakdown protection in the form of voltage drop devices such as forward-biased diodes.

Abstract: An improved Schottky diode structure (4) is formed by retrograde diffusing an N(^+) concentration of relatively fast diffusing atoms, preferably Phosphorus atoms, to form a localized diode NWell (6) as the diode substrate for the diode. A buried diode layer (5) formed of relatively slow diffusing N type atoms, preferably Antimony atoms, underlies the diode NWell and electrically couples the diode junction (7) to the diode ohmic contact (9). A diode ohmic contact region (31) underlies the ohmic contact, further coupling the diode junction to the ohmic contact. Preferably, the diode junction is a Platinum-Silicide junction. The improved Schottky diode structure may be formed as part of a BICMOS integrated circuit fabrication process wherein the buried diode layer may be formed at the same time as a buried collector layer of a bipolar transistor structure, the diode NWell may be formed at the same time as an NWell of a CMOS transistor structure and the diode ohmic contact region may be formed at the same time as a collector sink region. In the BICMOS fabrication process the buried collector layer definition mask is also a buried diode layer definition mask, the retro NWell definition mask is also a diode NWell definition mask, the collector sink definition mask is also a diode ohmic contact region definition mask, and the BICMOS contacts definition mask is also a diode junction and ohmic contact definition mask.

Abstract: The invention is an extendable compartment apparatus installed in a vehicle in such a manner that a platform can be cantilevered out from the vehicle body on an interlocking rail and bearing system. The apparatus includes a glidable platform, channel section stationary rails and angle section glidable rails. The glidable rails move along bearings which are located at the outermost end of the stationary rails and at the innermost end of the glidable rails, respectively. The glidable rails are limited in their movement such that they remain within the stationary structure along approximately one-third of their length. The platform can be mechanized using a DC motor and a rack-and-pinion gear system or worm gear. Finally, the glidable platform can be enclosed using side walls, a back wall, and a roof and thereby made weatherproof for use in combination with a camper vehicle.

Abstract: A wheeled storage box/cargo carrier used to transport small watercraft of the type including sailboards, canoes, and small sailboats comprising a storage container and detachable components. The carrier of the present invention may be pulled by hand, and a bicycle towing clamp enables the user to pull the carrier by bicycle. Large semi-pneumatic wheels permit the user to maneuver the carrier in locations that are otherwise inaccessible by motorized vehicles, such as through soft sand and over rough terrain. All of the components of the carrier are detachable and may be stored within said storage container. The storage container, in turn, is storable within or upon the watercraft. Most of the components of the present invention are fabricated of plastic or non-ferrous metals to reduce the detrimental effects of corrosion.

Abstract: Apparatus and process for the removal of moisture from cellulosic products such as pulp, paper and molded articles, and textile products, wherein gaseous water (steam) in a superheated state is utilized in an energy efficient manner as the drying medium. The apparatus is an enclosed system the operates continuously to dry the products while preventing air contamination from entering the apparatus and thereby reducing its drying efficiency. The apparatus comprises a plurality of drying sections wherein the number of drying sections connected in series is a function of the type and volume of the product or products to be dried. Within each drying section there exists indirect steam heating means, steam-recirculation means, an individual steam-supply chamber, and sections of a steam-return chamber which is open and common to all drying sections in the series. Air/vapor lock chambers at both ends of the apparatus prevent air incursion into the drying sections and at the same time permit a slight amount of excess steam from within the drying sections to vent out of the apparatus. Steam-condensing means located substantially entirely within the drying sections of the apparatus is utilized to recover a large percentage of the energy of the heat of vaporization. The process described herein involves conveying the products into the apparatus and directing the drying steam from the steam-supply chamber onto the products and drawing the spent steam away from the products. The spent steam, which comprises the drying steam in combination with the steam formed by the liberation of moisture from the products, is partially recirculated past the indirect heating means and back into the steam-supply chamber, and partially condensed by the internal steam-condensing means. The velocity at which the drying steam is directed onto the products can be varied in accordance with the type of product to be dried.

Abstract: Apparatus and process for the complete breaking down and incineration of tires and other difficult-to-dispose-of-waste products in an energy-efficient manner. Small particles of the waste material are directed into a furnace of novel design. Within the furnace, the particles are incinerated and thereby converted to combustion gas products. The combustion gas products exiting from the furnace are then transferred to an energy recovery/utilization means, such as a boiler. The small particles are specifically directed into a coiled ignition tube located completely within the furnace. As the particles travel in a downwardly spiraling motion through the ignition tube they come in contact with its heat-conducting interior walls. By forcing the particles to contact the interior walls, the ignition tube of the present invention leads to an efficient incineration of those particles. Everything which exits the ignition tube at a lower section of the furnace, including any residual particles and any unoxidized gases, is drawn up past the hot ignition tube and out at upper section of the furnace. In this way, the effective dwell time at high temperatures ensures that the final particulate matter is consumed within the furnace. Additionally, the furnace may be contoured so that all gases and particles exiting the ignition tube are forced to contact the hot ignition tube's external walls.

Abstract: A process and apparatus for reducing sludges, especially those sludges containing heavy metals and generated in electroplating, to a solid state where the toxic constituents of the waste are prevented from leaching. The process involves mixing a metallic soap with the sludge and then using low-temperature induction heating to form coacervate bonds that encapsulate the toxic waste particles in a pumice-like matrix. The apparatus allows a small amount of metallic soap to be thoroughly mixed through sludge and a continuous ribbon of the resulting putty-like waste to be fed into a series of microwave drying ovens and evacuation chambers. After the drying and dewatering sequences, the apparatus extrudes a pumice-like solid suitable for disposal in accordance with EPA regulations.

Abstract: A remotely controlled system for the operation of a vehicle wherein a limited physical input is translated into desired vehicle movement. The invention uses a unitary manipulator with two axes of movement to direct the steering, acceleration and braking functions of the vehicle. The surplus current available from the main battery of the vehicle powers the control system. The steering function of the invention involves the conversion of a mechanical input into a frequency-based signal which is processed by a primary steering microprocessor. This microprocessor in turn directs a frequency-based motor controller to operate a motor which rotates a steering shaft of the vehicle. The acceleration and braking functions operate in the same way, wherein a primary acceleration microprocessor acts upon a frequency-based signal to direct a frequency-based motor which is connected to the accelerator and brake pedals of the vehicle. In order to provide a smooth transition from the manipulator input to motor operation, the motors of the present invention are preferably stepper motors. The invention can be disengaged to permit standard operation of the steering wheel and accelerator and brake pedals of the vehicle.

Abstract: An improved power-up circuit for exerting control over output buffer devices in such a way as to disable these buffer devices during the period when the extended circuit is vulnerable to transient effects as the common power supply voltage V(cc) is rising during the "power-up" or "power-down" of the extended circuit. One particular such transient effect is the loading down of the power supply due to the buffer devices being in the current-sourcing and in the current-sinking states simultaneously. One improvement over the earlier circuitry is the provision of an asymmetry in the values of V(cc) at which control is transferred between the power-up circuit and the rest of the circuit as V(cc) is rising during power-up and as V(cc) is falling during power-down, respectively. In particular, the design of the present circuit allows control to be exerted over the buffer devices up to a relatively high value of V(cc) during power-up without exposing the extended circuit to the risk of being inadvertantly disabled upon the occurrence of noise-induced dip in V(cc) after the power supply voltage is up to its operating range. The asymmetry or hysteresis allows the cut-in voltage of the present circuit (during power-down) to be set at a lower value than the cut-out voltage (during power-up). The hysteresis is established by use of a second transistor in the power-up circuit which switches off at the same time that the threshold transistor switches on. A second improvement offered by the present circuit is the speed with which the cutting in and cutting out occurs. This speed is effected by the positive feedback means by which the second transistor is coupled with the switching transistor. As a consequence, the speed of switching is made independent of the edge rate of V(cc).

Abstract: A process and apparatus for reducing sludges, especially those sludges containing heavy metals and generated in electroplating, to a solid state where the toxic constituents of the waste are prevented from leaching. The process involves mixing a metallic soap or hydroxide with the sludge and then using low-temperature induction heating to form coacervate bonds that encapsulate the toxic waste particles in a pumice-like matrix. The apparatus allows a small amount of metallic soap to be thoroughly mixed through sludge and a continuous ribbon of the resulting putty-like waste to be fed into a series of microwave drying ovens and evacuation chambers. After the drying and dewatering sequences, the apparatus extrudes a pumice-like solid suitable for disposal in accordance with EPA regulations.

Abstract: A cleaning apparatus for cleaning under water structures that comprises a cylindrical brush having a plurality of bristles that extend radially outward, a sealed electric motor for axially rotating the cylindrical brush and a winch and cables to raise and lower the cylindrical brush as it cleans the under water structure. A substantially rectangular trough is displaced below the cleaning apparatus to collect debris that is removed from the underwater structure as the structure is being cleaned.