Patents by Inventor David R. Stevens

David R. Stevens 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).

  • Publication number: 20240146208
    Abstract: The disclosure relates to an electrical power system with current fault protection provided by current limiting diodes. Example embodiments include an electrical power system comprising: an electrical machine; an AC:DC power electronics converter connected to receive an input AC supply from the electrical machine and provide an output DC supply across first and second output terminals; a DC bus connected to first and second output terminals of the AC:DC power electronics converter; a load connected across the DC bus; a first circuit breaker switch and a first current limiting diode connected in series between the AC:DC power electronics converter and the DC bus; and a second circuit breaker switch and a second current limiting diode connected in series between the DC bus and the load, wherein the first current limiting diode is configured to limit current to a higher level than the second current limiting diode.
    Type: Application
    Filed: October 17, 2023
    Publication date: May 2, 2024
    Applicant: ROLLS-ROYCE plc
    Inventors: David R. TRAINER, Mark SWEET, Gian INCERPI, Jonathan M. STEVENS
  • Patent number: 6307955
    Abstract: An electronic signature management system includes a graphic tablet digitizer for signaling position coordinates of a stylus being moved to produce a handwritten signature, a clock circuit of the digitizer defining a fixed interval between successive stylus position measurements, a computer processor electrically interfaced with the tablet and programmed for receiving and storing a multiplicity of the coordinates in sequential order as an electronic signature forming a time history of the stylus movement.
    Type: Grant
    Filed: December 18, 1998
    Date of Patent: October 23, 2001
    Assignee: Topaz Systems, Inc.
    Inventors: Anthony E. Zank, David R. Stevens
  • Patent number: 5565495
    Abstract: Selegiline, or a pharmaceutically acceptable salt form of selegiline, is administered to mammals commencing at a point in time at which at least 50% of the mammal's life span is completed, with the administration continuing on a periodic but regular basis over the remaining life span of the mammal. The treatment, which shifts the survival curve, is especially useful for dogs.
    Type: Grant
    Filed: September 6, 1994
    Date of Patent: October 15, 1996
    Assignee: Deprenyl Animal Health, Inc.
    Inventors: David R. Stevens, William W. Ruehl
  • Patent number: 5561163
    Abstract: Selegiline and pharmaceutically acceptable analog forms thereof are used as treatments for hearing loss in mammals, especially dogs.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: October 1, 1996
    Assignee: Deprenyl Animal Health, Inc.
    Inventors: William W. Ruehl, David R. Stevens
  • Patent number: 5535314
    Abstract: A video image processor (100) for processing video images performing the steps of generating video images (103) with a multi-spectral video source (102), converting analog color data contained in the generated video images (103) to digital color data for subsequent signal processing, extracting the digital color data from designated areas of the generated video images and utilizing the extracted digital color data for identifying a color distinguishable from a background color. Thus, the video image processor (100) processes the generated video images and has an intrinsic immunity to the effects of shadows by exploiting multi-spectral color information to distinguish, for example, a passing vehicle from the roadway 116. In a preferred embodiment, the video image processor (100) includes a multi-spectral video source (102) for generating the video images.
    Type: Grant
    Filed: November 4, 1991
    Date of Patent: July 9, 1996
    Assignee: Hughes Aircraft Company
    Inventors: James F. Alves, Gerry R. Cacnio, David R. Stevens
  • Patent number: 5493072
    Abstract: A series connected capacitive graded high voltage cable terminator and suspension insulator made up of a number of individual modules each made by molding an insulating material between and around two flat, parallel plates molded of conductive material. The modules are connected in series by stacking them and the cable shield is introduced at one end while the bare conductor emerges from the stack cap. The electrical stress is uniformly divided by the number of capacitors in the series. The stack can also be used to suspend a bare high voltage conductor from a grounded tower.
    Type: Grant
    Filed: June 15, 1994
    Date of Patent: February 20, 1996
    Assignee: Amerace Corporation
    Inventor: David R. Stevens
  • Patent number: 5387615
    Abstract: Use of L-deprenyl for treatment of immune system dysfunction for mammals.
    Type: Grant
    Filed: August 27, 1993
    Date of Patent: February 7, 1995
    Assignee: Deprenyl Animal Health, Inc.
    Inventors: Norton W. Milgram, David R. Stevens, Gwendolyn O. Ivy
  • Patent number: 5276057
    Abstract: Use of l-deprenyl for treatment of immune system dysfunction for mammals.
    Type: Grant
    Filed: November 12, 1992
    Date of Patent: January 4, 1994
    Assignee: Deprenyl Animal Health, Inc.
    Inventors: Norton W. Milgram, David R. Stevens, Gwendolyn O. Ivy
  • Patent number: 5215475
    Abstract: Devices for use with high voltage system components for the safe expulsion of conductive moisture within such components include elbow and T-shaped connector bodies composed of insulating elastomeric bodies covered with conductive elastomer layers. The horizontal legs include all components normally found in such components. The bore of the vertical leg provides a circuitous passage from the horizontal leg to a container or the soil for the collection of such moisture. The circuitous path prevents the moisture from leaving as a stream and the grounded metal cap at the vertical leg extremity discharges any charge carried by the moisture. The circuitous path can be provided by modules each having a curved, linear or combined path such that the total path is longer than the length of the vertical leg. A vacuum access port can provide a means to draw out the moisture if gravity is insufficient to withdraw the moisture from the high voltage system components.
    Type: Grant
    Filed: July 2, 1992
    Date of Patent: June 1, 1993
    Assignee: Amerace Corporation
    Inventor: David R. Stevens
  • Patent number: 5106619
    Abstract: Vaccines employing inactivated viruses having improved retention of antigenic characteristics are prepared by psoralen-inactivation of the live virus in a non-oxidizing atmosphere. By excluding oxygen and other oxidizing species from the inactivation medium, degradation of the antigen characteristics resulting from irradiation with ultraviolet light is largely prevented. The resulting inactivated viruses are employed in vaccine preparations for the inoculation of susceptible hosts to inhibit viral infection.
    Type: Grant
    Filed: January 10, 1990
    Date of Patent: April 21, 1992
    Assignee: Diamond Scientific Co.
    Inventors: Gary P. Wiesehahn, Richard P. Creagan, David R. Stevens, Richard Giles
  • Patent number: 4946393
    Abstract: The invention is the provision of an access to the interior of a high voltage separable connector component by providing a projection of insulating elastomeric material integral with the insulating material of the body of the component and in engagement with the conductive elastomeric material shield of such component. A bore extends through the projection from a free, remote face to the component interior. The bore can be straight walled and if desired can be fitted at its remote end with appropriate fittings to permit external devices or internals to interact with the elements within said component body.
    Type: Grant
    Filed: August 4, 1989
    Date of Patent: August 7, 1990
    Assignee: Amerace Corporation
    Inventors: Alan D. Borgstrom, David R. Stevens
  • Patent number: 4791062
    Abstract: Novel vaccines for feline viral rhinotracheitis are prepared by psoralen inactivation of live Feline Herpesvirus I by exposure to ultraviolet radiation in the presence of an inactivating furocoumarin. The resulting inactivated viruses are suitable as the immunogenic substances in vaccines, which vaccines are useful for inoculation of hosts susceptible to feline virus rhinotracheitis.
    Type: Grant
    Filed: July 6, 1987
    Date of Patent: December 13, 1988
    Assignee: Diamond Scientific Co.
    Inventors: Gary P. Wiesehahn, Richard E. Giles, David R. Stevens
  • Patent number: 4693981
    Abstract: Vaccines employing inactivated viruses having improved retention of antigenic characteristics are prepared by psoralen-inactivation of the live virus in a non-oxidizing atmosphere. By excluding oxygen and other oxidizing species from the inactivation medium, degradation of the antigen characteristics resulting from irradiation with ultraviolet light is largely prevented. The resulting inactivated viruses are employed in vaccine preparations for the inoculation of susceptible hosts to inhibit viral infection.
    Type: Grant
    Filed: October 7, 1985
    Date of Patent: September 15, 1987
    Assignee: Advanced Genetics Research Institute
    Inventors: Gary P. Wiesehahn, Richard P. Creagan, David R. Stevens, Richard Giles
  • Patent number: 4556556
    Abstract: Novel vaccines for vesicular stomatitis virus are prepared by psoralen inactivation of the live virus under mild conditions in an inert atmosphere. The resulting inactivated virus can be used as a vaccine for inoculation of susceptible hosts to inhibit VSV infection.
    Type: Grant
    Filed: March 23, 1984
    Date of Patent: December 3, 1985
    Assignee: Advanced Genetics Research Institute
    Inventors: Gary P. Wiesehahn, Richard E. Giles, David R. Stevens
  • Patent number: 4545987
    Abstract: Novel vaccines of double-stranded RNA viruses are prepared by psoralen inactivation under mild conditions in an inert atmosphere, optionally in the presence of a mild singlet oxygen scavenger. The resulting inactivated virus can be used as a vaccine for inoculation of hosts to provide for the stimulation of the immune system to the virus.
    Type: Grant
    Filed: December 20, 1983
    Date of Patent: October 8, 1985
    Assignee: Advanced Genetics Research Institute
    Inventors: Richard E. Giles, David R. Stevens, Gary P. Wiesehahn
  • Patent number: 4006288
    Abstract: A connector construction having component parts adapted to be assembled in the field at the termini of a pair of high voltage shielded electrical cables includes a pair of sleeves of elastomeric material adapted to be secured over the insulating jacket on each of the cable ends, connector means for joining the conductive cores of the cables, a housing adapted to overlie the sleeves and the connector means and defining an interior chamber surrounding the connector means, and a pair of retaining members adapted to be directly affixed to each of the conductive cores respectively, in an abutting relation to the terminus of a corresponding sleeve and cable insulating jacket for precluding axial movement of the sleeve toward the cable termini.
    Type: Grant
    Filed: December 5, 1975
    Date of Patent: February 1, 1977
    Assignee: Amerace Corporation
    Inventor: David R. Stevens