Patents by Inventor John P. Doughty

John P. Doughty 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).

  • Combined smoke and gas detection apparatus
    Patent number: 4688021
    Abstract: A combined smoke and gas detector utilizes a conventional smoke detector IC (44) which is operable to drive a piezo element (46) and an LED (94) to provide indication of a smoke or gas detection. An ionization chamber (58) is operable to detect smoke and a gas detector (98) is operable to detect gas. A comparator (104) detects the output of the gas detector (98) for input to the logic circuitry of the IC (44). The LED (94) is modulated to provide a distinction between gas detection and smoke detection in addition to the tone output from the piezo element (46).
    Type: Grant
    Filed: March 11, 1986
    Date of Patent: August 18, 1987
    Assignee: BDC Electronics
    Inventors: Robert H. Buck, Kent G. Cowan, John P. Doughty, Stephen E. Marshall