Patents by Inventor David W. Hawkes

David W. Hawkes 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).

  • Electrical circuit testing
    Patent number: 4301403
    Abstract: A method of testing operation of an electrical circuit involves supplying a test signal to circuit terminals (1 to 4), which signal may be a pulsed signal, to the circuit, thereby to switch off a switch component (ZD1). When the circuit is in this condition, further test signals may be applied to the terminals (1 to 4) to test operation of other circuit components (11, 12, 13, ZD2). The method is particularly applicable to circuits, e.g. diode safety barriers, that are encapsulated and require testing after encapsulation, when only terminals (1 to 4) are exposed for connection into an external circuit.
    Type: Grant
    Filed: December 21, 1979
    Date of Patent: November 17, 1981
    Assignee: Measurement Technology Ltd.
    Inventors: David W. Hawkes, Ian C. Hutcheon
  • Single-direction diverting pusher element for a sorting conveyor
    Patent number: D411363
    Type: Grant
    Filed: January 9, 1998
    Date of Patent: June 22, 1999
    Assignee: The Buschman Company
    Inventors: Paul L. Black, Martin A. Heit, David W. Hawke, James W. Halsey, Allen C. Brown, Raymond R. Neiser
  • Dual-direction diverting pusher element for a sorting conveyor
    Patent number: D411680
    Type: Grant
    Filed: January 9, 1998
    Date of Patent: June 29, 1999
    Assignee: The Buschman Company
    Inventors: Paul L. Black, Martin A. Heit, David W. Hawke, James W. Halsey, Allen C. Brown, Raymond R. Neiser