Patents by Inventor Doyle W. Hand

Doyle W. Hand 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).

  • Electronic delay timer and alarm system
    Patent number: 5165107
    Abstract: A time delay and alarm system is provided to ensure safe operation of periodically activated apparatus having potentially dangerous moving parts. The system preferably employs a 555 type integrated timer circuit, a horn, and a pulse generator which causes the horn to produce a cyclical sound.
    Type: Grant
    Filed: July 2, 1990
    Date of Patent: November 17, 1992
    Inventors: Doyle W. Hand, Thomas M. Holt