Patents by Inventor Phillip L. Harden

Phillip L. Harden 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: 4206450
    Abstract: A security system which includes closed loop fire detection circuitry, having a continuous monitor of the pyrogenic sensors, closed loop intrusion detection circuitry, a multiple tone audible alarm generator, a coded keyboard digital electronic lock circuit, and a fail-safe alternating current, direct current power supply which includes a battery, battery charging circuit, and a system testing facility. The audible alarm circuitry includes a modulated tone frequency generator and a modulating circuit operable between a plurality of states in response to different alarm conditions. The fire and intrusion circuits include filter circuits to prevent spurious operation, and feedback latching circuits for generating continuous alarm signals in response to a breach of the system. The entire circuit is fabricated with solid state electronic components including micro-electronic circuitry.
    Type: Grant
    Filed: December 26, 1974
    Date of Patent: June 3, 1980
    Assignee: Bowmar Instrument Corporation
    Inventors: Phillip L. Harden, William E. Hunkler, John L. Schnieders, John E. Weber
  • Patent number: 4163138
    Abstract: A flush lighted flat keyboard assembly including a printed circuit board having conductors on one side. Resilient dome switch elements are supported on the one side of the board in spaced-apart relationship in peripheral contact with certain conductors to make center contact with other conductors upon the application of force thereon. Another printed circuit board has one side in facing relationship with the first board and has openings therein respectively in alignment with the switch elements. Light sources are mounted on the other side of the second board which has conductors thereon connected to energize the light sources. A flexible switch-actuating member has one side in facing relationship with the other side of the second board and has switch-actuating projections extending therefrom through the second board openings toward the switch elements. The one side of the actuating member also has isolator projections thereon intermediate the switch-actuating projections, which extend toward the second board.
    Type: Grant
    Filed: March 17, 1978
    Date of Patent: July 31, 1979
    Assignee: Bowmar Instrument Corporation
    Inventor: Phillip L. Harden
  • Patent number: 4071718
    Abstract: A flat keyboard assembly including a printed circuit board having conductors on one side thereof. Resilient dome switch elements are supported on the one side of the board in spaced-apart relationship in peripheral contact with certain conductors and adapted to make center contact with other conductors upon the application of force thereon. A sheet of relatively thin insulating material covers the one side of the board, the dome elements and the conductors thereon. A switch-actuating member formed of relatively thin, flexible insulating material is in facing relationship with the insulator sheet and has switch-actuating protrusions thereon respectively in alignment with the switch elements and extending toward and contacting the insulator sheet. The actuating member also has isolator protrusions thereon intermediate the switch-actuating protrusions and respectively in alignment with the spaces between the dome elements and extending toward the insulator sheet.
    Type: Grant
    Filed: October 22, 1976
    Date of Patent: January 31, 1978
    Assignee: Bowmar Instrument Corporation
    Inventor: Phillip L. Harden