Patents Represented by Attorney, Agent or Law Firm Thomas L. Bohan
  • Patent number: 5644460
    Abstract: Device for protecting against circuit-damaging voltage spikes at input nodes and output nodes of electrical circuits and between high- and low-potential power rails. The voltage spikes are of the type identified generally as electrostatic discharges. The device includes a plurality of semiconductor elements, which are preferably bipolar transistors, coupled to the power rails and an input node or an output node of the circuit such that all types of electrostatic discharges can be diverted using the single device of the present invention. In the preferred embodiment of the invention the transistors have a common collector, their bases are open, and they are configured so that the emitter of one transistor is coupled to the high-potential power rail, the emitter of a second transistor is coupled to the low-potential power rail, and the emitter of a third transistor is coupled to the node to be protected.
    Type: Grant
    Filed: May 13, 1996
    Date of Patent: July 1, 1997
    Assignee: National Semiconductor Corporation
    Inventor: Stephen W. Clukey
  • Patent number: 5635784
    Abstract: An ultrasonic imaging device including a bearingless levitating rotor for rotating a reflective mirror. The device may be used to image from within a hollow object and is particularly suited for use in intravascular imaging. The levitation of the rotor is achieved by forming the rotor as a permanent magnet structure having three distinct magnet regions, two having opposing dipole moments axial to the rotor orientation and one having a dipole moment transverse to the rotor orientation, the transverse magnetic region lying between the first and third magnetic regions. The rotor is radially centered within a housing using passive magnetic suspension elements, including permanent magnet stators at opposite ends of the housing. The rotor is axially positioned within the housing with an active servo feedback controller. Position-drive and sense coils are used to move and detect the positioning of the rotor. Rotation drive coils operate on the transverse magnetic region to cause the rotor to spin.
    Type: Grant
    Filed: February 13, 1995
    Date of Patent: June 3, 1997
    Inventor: Joseph B. Seale
  • Patent number: 5627801
    Abstract: An acoustic resonance chamber in an underwater pinger is designed to enhance the acoustic emission from the pinger. An electro-acoustic transducer of the pinger is positioned away from a reflective surface of the pinger housing by a distance chosen in proportion to the wavelength of the fundamental frequency of the acoustic emission. This creates a resonant condition at the transducer, maximizing the acoustic output. This design also causes a maximum transfer of the acoustic wave through the pinger housing and into the surrounding water.
    Type: Grant
    Filed: July 20, 1995
    Date of Patent: May 6, 1997
    Inventor: David N. Saunders
  • Patent number: 5624009
    Abstract: A wheelchair lift system enabling wheelchair accessibility between stair levels for persons incapable of traversing stairs under their own power. The key of the invention is a free-rolling, wheeled platform suspended between two arcuate tracks which are lifted and lowered by synchronized, reversible, worm-gear drive mechanisms. The platform and tracks are mounted on a frame in which also resides peripheral equipment needed to raise and lower the system. A seven-foot-high portal frame supports the drive mechanism which comprises pivoting, worm-gear type drive motors, turning long worm-gears extending vertically downward from the top of the frame to the floor and engaging pivoting worm-gear heads that are attached to the arcuate tracks, while allowing normal access to the stairs.
    Type: Grant
    Filed: February 14, 1996
    Date of Patent: April 29, 1997
    Inventors: Kevin S. Benjamin, Kurt H. Cushwa
  • Patent number: 5624409
    Abstract: A dynamic controller for quantitative rapid-pulse flow control over a wide dynamic range (1000-to-1) forms a fluid path from a pressurized source to a sink. The fluid path travels, typically in a disposable cassette, from the pressure source via a fast (one millisecond) on-off source control valve into a volume-displacement interface area, thence to a fast on-off load control valve and on to the sink. The load control valve may be replaced by a passive flow restrictor where less dynamic range is required. From the reusable controller side, fast actuators are energized to open the normally-closed valves. A volume sensor mates with the volume-displacement interface area. This sensor uses an incompressible transfer fluid, typically different than and isolated from the deliverable fluid by membranes, to transmit volume displacement change into a transducer area for conversion from volume to a measurable electrical signal, typically a frequency.
    Type: Grant
    Filed: June 10, 1994
    Date of Patent: April 29, 1997
    Assignee: FluidSense Corporation
    Inventor: Joseph B. Seale
  • Patent number: 5617808
    Abstract: A portable boat for all commercial and recreational uses, with particular application to shallow water situations. The boat comprises a multi-tube flotation perimeter hull constructed of connected, epoxy-laminated foam cores and totally encased with a vinyl polyester fabric; a reinforced floor portion and, a full rear transom means. This water craft is strong, yet flexible, unsinkable and virtually impervious to punctures and abrasion damage. These positive benefits are accomplished without sacrificing the advantages of lightweight construction and ease of transportation.
    Type: Grant
    Filed: July 5, 1996
    Date of Patent: April 8, 1997
    Inventor: Glenn R. Robinson
  • Patent number: 5615942
    Abstract: A light socket adapter designed for use with fluorescent tubular lamps. The light socket adapter includes a lamp socket, an adjustable support element, and an adjusting device. The adjusting device includes a first adjusting component connected to the lamp socket and a second adjusting component connected to the support element. The first adjusting component is detachably and rotatably connected to the second adjusting component allowing the positioning of the lamp socket at any desired angle relative to the second adjusting component. The light socket adapter optionally includes a middle connecting component for use between the first adjusting component and the second adjusting component. The middle connecting component allows positioning of the lamp socket at any desired angle relative to the support element.
    Type: Grant
    Filed: June 5, 1995
    Date of Patent: April 1, 1997
    Inventor: John P. Langis
  • Patent number: 5617048
    Abstract: A power-up circuit with hysteretic characteristics for regulating the activation of one or more output buffers of an extended logic circuit. The hysteresis of the power-up circuit of the invention permits turn on of a switching transistor of the circuit at one threshold voltage level and maintains the active state of that switching transistor until a second lower threshold voltage level. The hysteresis is achieved by providing two separate and electrically isolated control paths that are connected to the control node of the switching transistor. The first control path includes a plurality of diode devices designed to regulate the power supply level required to turn on the switching transistor. The second control path also includes diode devices but in lesser numbers so that, once the switching transistor is turned on by the first control path, it remains on in spite of fluctuations at the power supply rail.
    Type: Grant
    Filed: March 13, 1996
    Date of Patent: April 1, 1997
    Assignee: National Semiconductor Corporation
    Inventors: Michael G. Ward, Roy L. Yarbrough, Jay R. Chapin
  • Patent number: 5608929
    Abstract: A positioning device for people in hospital beds is disclosed. The device includes a sheet which is placed under the patient. This is connected by rope to an apparatus on the headboard of the bed. Either by the bed's existing motor, or an independent motor, the patient is moved up in bed towards the headboard. This action eliminates the need for two or more people for the job of positioning a person in bed. The chance of an on-the-job injury is also greatly reduced with this positioning aid.
    Type: Grant
    Filed: January 11, 1996
    Date of Patent: March 11, 1997
    Inventor: Lawrence Crane
  • Patent number: 5609678
    Abstract: Solvent formulations used in thinning oil-based resins and in cleaning equipment contaminated with oil-based resins include mixtures of constituents with low-, or no-toxicity and flash points generally considered to be above flammability levels. The formulations are compatible with such resins and further have drying characteristics suitable for most users. The solvating power and drying characteristics of these formulations are equivalent to turpentine and mineral spirits, but without the safety concerns associated with those thinners. The formulation components of the present invention include propylene glycol ethers comprising no more than 60% by weight of the solvent mixture, no more than 10% by weight of an isoalkane compound, and no more than 30% by weight of an oxidizing oil, and no more than 30% by weight of an odor-masking compound, preferably d-limonene.
    Type: Grant
    Filed: May 9, 1995
    Date of Patent: March 11, 1997
    Assignee: American Color Company
    Inventor: Leo M. Bergman
  • Patent number: 5592113
    Abstract: An error-limiting circuit for regulating the time required to bring the output signal of a control system such as a phase-locked loop device into conformance with a reference input signal. For a phase-locked loop system the error-limiting circuit is a phase-error-limiting circuit that provides for a gradual changing of the signal frequency of a voltage-controlled oscillator of the phase-locked loop device so that frequency synchronization of subsequent devices coupled to the phase-locked loop with the reference signal is ensured. The phase-error-limiting circuit forms part of the phase-frequency detector that is coupled to a charge pump that outputs current to a loop filter that in turn effectively controls the voltage-controlled oscillator. The phase-error-limiting circuit acts to assert or de-assert as required an error-correcting UP or DOWN signal to the charge pump.
    Type: Grant
    Filed: March 28, 1995
    Date of Patent: January 7, 1997
    Assignee: National Semiconductor Corp.
    Inventors: Duane G. Quiet, E. Wayne Porter
  • Patent number: 5578260
    Abstract: A system and method for making an impression of a foot, an ankle, and a lower leg to be used in the fabrication of custom-made shoes. The system has a molding component made of a compressible foam or a combination of compressible foams made into prefabricated pieces, and a protective component made of plastic, cardboard, or other disposable material enclosing the molding component. The protective component may be securely affixed to the molding component and is designed to be used for mailing or storing the foot-ankle-lower leg impression.
    Type: Grant
    Filed: October 6, 1994
    Date of Patent: November 26, 1996
    Inventor: Danforth DeSena
  • Patent number: 5565807
    Abstract: A BiCMOS power-up circuit for delaying the operation of an extended circuit until the voltage available to the high-potential power rail of the extended circuit is sufficiently high that all elements of the extended circuit will be powered at a high enough voltage to function correctly. The power-up circuit of the present invention has its most direct application to three-state output buffers connected to a common bus, and in this context this circuit can maintain the output buffers in their high-Z, inactive state until the voltage available from the circuit-energizing power-supply has risen high enough that all of the stages of the buffers will operate correctly, and in particular will not be current-sourcing and current-sinking simultaneously.
    Type: Grant
    Filed: September 16, 1994
    Date of Patent: October 15, 1996
    Assignee: National Semiconductor Corporation
    Inventor: Michael G. Ward
  • Patent number: 5559664
    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.
    Type: Grant
    Filed: June 7, 1993
    Date of Patent: September 24, 1996
    Assignee: Frost Controls, Inc.
    Inventors: James Dogul, Sandip Sarkar, Frederick Thomson, Robert Thomson
  • Patent number: 5559707
    Abstract: A computer aided routing system (CARS) determines a travel route between a user selected travel origin and travel destination following user selected waypoints along the way. A CARS database incorporates travel information selected from a range of multimedia sources about the transportation routes, waypoints, and geographically locatable points of interest (POIs) selected by the user along the travel route. The CARS software permits user selection of specified POI types within a user defined region of interest and user selection of particular POIs from the selected types within the region of interest. The transportation routes, waypoints, POIs and region of interest are identified in the computer by coordinate locations of a selected geographical coordinate system. The CARS software is constructed to present a user customized travelog for preview on the computer display of the user defined travel route.
    Type: Grant
    Filed: January 31, 1995
    Date of Patent: September 24, 1996
    Assignee: DeLorme Publishing Company
    Inventors: David M. DeLorme, Keith A. Gray
  • Patent number: 5553684
    Abstract: A remotely-controlled system for the operation of the gas and brake pedals of a vehicle wherein a limited physical input is translated into desired vehicle acceleration and braking. A single joystick lever is linked electronically to mechanical components connected to the gas and brake pedals so as to operate those pedals in a fly-by-wire manner. The joystick lever is optionally tied to a feedback mechanism that permits the driver to adjust the resistance felt upon movement of the lever. In that way, the feel for the vehicle's operation can be experienced more readily. The control system of the present invention permits able-bodied operation of the vehicle without any interference.
    Type: Grant
    Filed: August 29, 1994
    Date of Patent: September 10, 1996
    Inventor: Scott A. Bolduc
  • Patent number: 5549782
    Abstract: A laminating apparatus is disclosed which is particularly suited to mount holograms on plastic cards. The apparatus comprises a planar support supporting the work pieces to be laminated. A press stamp has a shape of a sector of a circular cylinder wall and is driven by means of a special gear to perform a hobbing motion along the to-be-laminated area.
    Type: Grant
    Filed: June 17, 1994
    Date of Patent: August 27, 1996
    Assignee: MELZER Maschinenbau GmbH
    Inventor: Bernhard Baist
  • Patent number: 5536966
    Abstract: An improved Schottky transistor structure (6), including a bipolar transistor structure (7) and a Schottky diode structure (8), is formed by retrograde diffusing relatively fast diffusing atoms to form a localized retrograde diode well (9) as the substrate for the Schottky diode structure. An expanded buried collector layer (11) formed of relatively slow diffusing atoms underlies the base and collector regions of the bipolar transistor structure (7) and the retrograde diode well (9). A diode junction (10) is formed by expanding the base contact of the bipolar transistor structure to include the surface of the retrograde diode well. Preferably, the diode junction is a Platinum-Silicide junction.
    Type: Grant
    Filed: August 15, 1994
    Date of Patent: July 16, 1996
    Assignee: National Semiconductor Corporation
    Inventors: Murray J. Robinson, Christopher C. Joyce, Timwah Luk
  • Patent number: 5533381
    Abstract: Volume of a working liquid in a sensing chamber is measured via a first mechanical resonance frequency. A second resonance may be measured to discriminate interacting volume and density effects, yielding corrected volume, density, and liquid mass. A probability of bubbles present in the liquid is indicated by an abnormal combination of first and second resonances. Determination of a frequency and an associated phase angle near a resonance may be used to discriminate interacting volume and viscosity effects, yielding corrected volume and viscosity. One boundary of the sensing chamber is a deformable plate, which may be rippled to increase the range of linear volumetric compliance. A second boundary paralleling the plate captures a thin variable-thickness fluid layer. Vibrations in the plate cause amplified fluid vibrations parallel to the plate surface, causing a high, thickness-sensitive fluid inertia that lowers plate resonance frequencies in a volume-sensitive manner.
    Type: Grant
    Filed: June 10, 1994
    Date of Patent: July 9, 1996
    Inventor: Joseph B. Seale
  • Patent number: 5521789
    Abstract: An enhanced bipolar-transistor apparatus for protecting electronic devices from electrostatic discharge damage. The apparatus is built around a bipolar transistor coupled between a power rail and the circuit to be protected. The protection is based on the high-current-capacity path through the bipolar transistor which is opened up either by collector-to-emitter punch-through in the bipolar transistor or by the bipolar transistor going into normal conduction upon being turned on by a switch coupled to the base of the bipolar transistor. In the preferred embodiment the switch is a MOS transistor that is designed to undergo source-to-drain breakdown at a fixed threshold voltage, whereupon it activates the bipolar transistor which in turn discharges the overvoltage.
    Type: Grant
    Filed: March 15, 1994
    Date of Patent: May 28, 1996
    Assignee: National Semiconductor Corporation
    Inventors: James R. Ohannes, Stephen W. Clukey, E. David Haacke, Roy L. Yarbrough