Patents by Inventor R. Davidson

R. Davidson has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 4873469
    Abstract: A switch assembly actuated by passive infrared radiation for operating a light in a space, the switch assembly including an optical system which senses infrared radiation over a 180.degree. range in horizontal plane including two separate vertical fields of view, a generally horizontal "look-out" field and a vertical semi cone-shaped "look-down" sensing field for directing to a common sensing element passive infrared radiation produced by a person moving within the sensing field of the switch assembly, the sensing element connected to a control circuit which responsively turns on the light, maintains the light on while the person remains in the space, and turns the light off automatically when the person leaves the space. The switch assembly includes a one-piece optical shell enclosed within a housing which is adapted for installation in a conventional light switch box in room.
    Type: Grant
    Filed: October 14, 1987
    Date of Patent: October 10, 1989
    Assignee: Pittway Corporation
    Inventors: William A. Young, Wai-Shing Ko, Curtis R. Davidson, Thomas Whitehurst
  • Patent number: 4849128
    Abstract: An aqueous composition for conditioning an aqueous system, for example a sewage slurry, comprises an alkaline earth metal hydroxide, e.g. lime, and an anionic oligomeric polyelectrolyte, e.g. a salt of polyacrylic acid which composition has at least 40% by weight of particulate solid materials. Other components may include a weighting agent, e.g. calcium carbonate, a cationic flocculant, e.g. a polyacrylamide, and a base such as sodium hydroxide.
    Type: Grant
    Filed: April 30, 1984
    Date of Patent: July 18, 1989
    Assignee: Blue Circle Industries Limited
    Inventors: Alban Timmons, Richard R. Davidson
  • Patent number: 4816805
    Abstract: Signal processing techniques are disclosed for applications such as finite impulse response filtering. After initial processing in residue number system (RNS) channels, the signals are converted from residue form to a true external representation of the filter output. The conversion employs a chinese remainder theorem decoder and shift accumulator controlled to utilize adaptive modulo reduction. As a consequence, each modulus function value is reduced during computation when it exceeds the modulus and not at the end of the function evaluation. This reduces hardware requirements by minimizing the arithmetic word length. In implementing the technique, each function value is tested to see if it is within a modulus range and the corresponding modulus value is subtracted if it is not. This is done as many times as is necessary to bring each function value within the range.
    Type: Grant
    Filed: February 2, 1987
    Date of Patent: March 28, 1989
    Assignee: Grumman Aerospace Corporation
    Inventors: William M. Vojir, Joel R. Davidson
  • Patent number: 4718268
    Abstract: A method of detecting contraband substances in freight cargo containers in which the container is agitated to disturb particulates therein, and air containing such particulates is then sampled and the particulates collected. The collected particulates include naturally occurring particulates which have absorbed vapors of the contraband substance during the entire time that the container has been closed, and also include particulates of the contraband substance itself. The collected particulates are then heated to a temperature above 160.degree. C. to drive off vapors indicative of the contraband substance and the vapors are analyzed in a mass analyzer.
    Type: Grant
    Filed: June 4, 1985
    Date of Patent: January 12, 1988
    Assignee: British Aerospace Public Limited Company
    Inventors: Neil M. Reid, William R. Davidson
  • Patent number: 4711727
    Abstract: An aqueous slurry of mineral particles, for example calcium carbonate and/or calcium hydroxide, has a mineral solids concentration of at least 40% m/m and contains an agent that maintains the slurry at a pumpable viscosity but that acts as a flocculant upon dilution of the slurry. Suitable agents include cationic and amphoteric polyelectrolytes having nitrogen-containing groups, for example polyamines and dimethyl diallyl ammonium chloride polymers. The slurries may contain other components, for example a synthetic hectorite or a dispersing agent such as a polyacrylate, polymethacrylate or polyphosphate. The slurries are useful in papermaking and in the treatment of sewage.
    Type: Grant
    Filed: July 29, 1986
    Date of Patent: December 8, 1987
    Assignee: Blue Circle Industries, PLC
    Inventors: Kenneth B. Matthews, Christine A. Beckett, David E. Smith, Richard R. Davidson
  • Patent number: 4619055
    Abstract: A cushioning pad or mat for protecting the human foot and body while walking or standing. The mat is of a bonded, multi-layer construction with an upper moisture-absorbing layer, an intermediate resilient layer of foam rubber which will mold to the individual's particular foot contour and irregularities and a lower shock-absorbing layer of soft natural latex rubber which is resilient and has memory. Air holes are provided at spaced intervals through the mat and the special cellular design provides a bellows action to enhance the flow of air around and through the mat as well as to improve blood circulation in the extremities of the user. In the preferred embodiment, the mat is configured as an insole for insertion of footwear. In other embodiments, the mat may be used as protective knee pads, helmet liners and the like.
    Type: Grant
    Filed: October 29, 1984
    Date of Patent: October 28, 1986
    Inventor: Murray R. Davidson
  • Patent number: 4610801
    Abstract: An aqueous slurry of mineral particles, for example calcium carbonate and/or calcium hydroxide, has a mineral solids concentration of at least 40% m/m and contains an agent that maintains the slurry at a pumpable viscosity but that acts as a flocculant upon dilution of the slurry. Suitable agents include cationic and amphoteric polyelectrolytes having nitrogen-containing groups, for example polyamines and dimethyl diallyl ammonium chloride polymers. The slurries may contain other components for example a synthetic hectorite or a dispersing agent such as a polyacrylate, polymethacrylate or polyphosphate. The slurries are useful in papermaking and in the treatment of sewage.
    Type: Grant
    Filed: October 22, 1985
    Date of Patent: September 9, 1986
    Assignee: Blue Circle Industries PLC
    Inventors: Kenneth B. Matthews, Christine A. Beckett, David E. Smith, Richard R. Davidson
  • Patent number: 4590829
    Abstract: A food slicing method and apparatus includes blades mounted on a shaft for rotation therewith, the blades successively converging and diverging to slice the food pieces as the shaft rotates. An inlet flume conveys the food pieces to and through the rotating blades. A flighted conveyor within the flume submerges the food pieces at the flume inlet and releases them at the bottom of the flume to float upward, oriented according to their buoyancy before entering the blades. In one embodiment, the blades are mounted on a curved shaft which rotates about a longitudinal axis of symmetry to cause the blades to converge on the inward side of the shaft and diverge on the outward side. The blades engage a synchronously counterrotating drum to slice the food pieces as they enter on the inward side of the shaft. As the blades diverge, the majority of the slices fall free of the blades.
    Type: Grant
    Filed: June 15, 1984
    Date of Patent: May 27, 1986
    Assignee: Amfac Foods Monterey, Inc.
    Inventors: Arthur R. Davidson, Richard S. Livermore
  • Patent number: 4580440
    Abstract: A method of detecting contraband substances in freight cargo containers in which the container is agitated to disturb particulates therein, and air containing such particulates is then sampled and the particulates collected. The collected particulates include naturally occurring particulates which have absorbed vapors of the contraband substance during the entire time that the container has been closed, and also include particulates of the contraband substance itself. The collected particulates are heated to drive off vapors indicative of the contraband substance and the vapors are analyzed in a mass analyzer.
    Type: Grant
    Filed: July 17, 1984
    Date of Patent: April 8, 1986
    Assignee: British Aerospace Public Company Limited, Bracknell Division
    Inventors: Neil M. Reid, William R. Davidson
  • Patent number: 4552448
    Abstract: An apparatus which advances a sheet into registration with information developed on a moving member. A sheet gripper transports the sheet in a recirculating path. The sheet gripper is detachably coupled to the member over a portion of the path of movement thereof to place the sheet in registration with the information developed on the member. Thereafter, the sheet gripper is decoupled from the member to move independently thereof.
    Type: Grant
    Filed: February 27, 1984
    Date of Patent: November 12, 1985
    Assignee: Xerox Corporation
    Inventor: James R. Davidson
  • Patent number: 4434729
    Abstract: A work manipulating mechanism for a sewing machine attachable to the presser bar thereof which utilizes a pair of spaced apart endless belts on a first drive plate to feed an endless quantity of work material through a sewing machine in the formation of an ornamental pattern or monogramming, the first drive plate being shiftable in an orthogonal direction by a second drive plate attachable to the presser bar of a sewing machine. The first drive plate may be shifted by a rack and pinion connection to a stepper motor supported on the second drive plate, and the work material may be shifted by a stepper motor connected to one of a pair of shafts carrying sprockets encircled by the endless belts in contact with the work material.
    Type: Grant
    Filed: December 29, 1980
    Date of Patent: March 6, 1984
    Assignee: The Singer Company
    Inventor: Donald R. Davidson
  • Patent number: 4407589
    Abstract: A method and apparatus for correcting errors in an electronic digital timepiece that includes an oscillator which has a 2.sup.n frequency output, an n-stage frequency divider for reducing the oscillator output frequency to a time keeping frequency, and means for displaying the count of the time keeping frequency. The error E in the time of the timepiece for an arbitrary period of time T is determined. A computer computes a new adjustment value N+(2.sup.n-m +N)E/T where N is the preceding adjustment value and m is a nonnegative integer less than n. Then the 2.sup.n-m divisor of the first n-m stages of the n-stage frequency divider is adjusted in an amount equal to the new adjustment value. In first and second embodiments of the invention the timepiece is synchronized with a time standard at the beginning of the period of time T.
    Type: Grant
    Filed: February 13, 1981
    Date of Patent: October 4, 1983
    Inventors: John R. Davidson, Joseph S. Heyman
  • Patent number: 4386573
    Abstract: An embroidery attachment for a sewing machine having electronic controls influencing the stitch forming instrumentalities. The attachment work holding frame is shifted by operative connections with the stitch forming instrumentalities. Alternative constructions are disclosed utilizing electronically controlled sewing machine needle bar and feed dog movements to drive the embroidery attachment.
    Type: Grant
    Filed: October 20, 1982
    Date of Patent: June 7, 1983
    Assignee: The Singer Company
    Inventors: Donald R. Davidson, Gerhard Reinert
  • Patent number: 4380961
    Abstract: A variable pull-off mechanism for a sewing machine is provided with a thread pull-off disc on a rotatably mounted shaft which is concentric with the drive shaft of a vertical axis looptaker. The disc is formed with thread catching edges which engage and pull-off thread from a bobbin as the disc is oscillated between a fixed and a controllable position in accordance with the operation of a servomotor responsive to various control signals.
    Type: Grant
    Filed: March 23, 1981
    Date of Patent: April 26, 1983
    Assignee: The Singer Company
    Inventors: Gerhard Reinert, Donald R. Davidson
  • Patent number: 4372237
    Abstract: A monogram sewing system comprising a monogram sewing machine capable of needle feeding as well as underbed feed dog feeding of the work piece, an articulated presser foot, and a work holding frame for constraining feeding motion of the work piece to translatory motion.
    Type: Grant
    Filed: December 24, 1981
    Date of Patent: February 8, 1983
    Assignee: The Singer Company
    Inventors: Peter J. Totino, Donald R. Davidson
  • Patent number: 4360416
    Abstract: A gas generating apparatus and method is described which utilizes a novel catalytic halogen evolving electrode for electrochemical systems, such as an electrolysis cell for the generation of chlorine. The electrochemical cells include a catalytic cathode and an improved catalytic anode positioned on opposite sides of, and bonded to, a solid polymer electrolyte membrane. A source of direct current potential between the cathode and the anode and means for removing gas from at least one of the electrodes are provided. The improved catalytic anode is an alloy of ruthenium oxide and manganese oxide.
    Type: Grant
    Filed: April 27, 1981
    Date of Patent: November 23, 1982
    Assignee: General Electric Company
    Inventors: Craig R. Davidson, John M. Sedlak
  • Patent number: 4333805
    Abstract: A gas generating apparatus and method is described which utilizes a novel catalytic halogen evolving electrode for electrochemical systems, such as an electrolysis cell for the generation of chlorine. The electrochemical cells include a catalytic cathode and an improved catalytic anode positioned on opposite sides of, and bonded to, a solid polymer electrolyte membrane. A source of direct current potential between the cathode and the anode and means for removing gas from at least one of the electrodes are provided. The improved catalytic anode is an alloy of ruthenium oxide and manganese oxide.
    Type: Grant
    Filed: April 27, 1981
    Date of Patent: June 8, 1982
    Assignee: General Electric Company
    Inventors: Craig R. Davidson, John M. Sedlak
  • Patent number: 4316562
    Abstract: A button attaching tool is provided with a base, a pair of needles which have collapsible and expandable thread receiving eyes and which project from the base for use in penetrating a layer of material and the holes of a button to be attached to the material, and a member for stripping the material and button from the needles.
    Type: Grant
    Filed: May 2, 1980
    Date of Patent: February 23, 1982
    Assignee: The Singer Company
    Inventors: Donald R. Davidson, Wesley R. Peterson
  • Patent number: 4296698
    Abstract: A button attaching hand tool is provided with a box-like structure which includes a fixed and adjustable needle, and which includes a button storage compartment. A slidable shroud on the box-like structure for extricating a button and material from the needles is movable between a position in which an operator is shielded from injury by the needles and another position in which the needles are exposed for button sewing use.
    Type: Grant
    Filed: July 14, 1980
    Date of Patent: October 27, 1981
    Assignee: The Singer Company
    Inventors: Donald R. Davidson, Walter H. W. Marsh
  • Patent number: 4289591
    Abstract: A gas generating apparatus and method is described which utilizes a novel catalytic oxygen evolving electrode for electrochemical systems, such as an electrolysis cell for the generation of oxygen. The electrochemical cells include a catalytic cathode and an improved catalytic anode positioned on opposite sides of, and bonded to, a solid polymer electrolyte membrane. A source of direct current potential between the cathode and the anode and means for removing gas from at least one of the electrodes are provided. The improved catalytic anode is an alloy of ruthenium oxide and manganese oxide.
    Type: Grant
    Filed: May 2, 1980
    Date of Patent: September 15, 1981
    Assignee: General Electric Company
    Inventors: Craig R. Davidson, John M. Sedlak