Patents by Inventor Richard M. Sheff

Richard M. Sheff 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: 4075624
    Abstract: An electronic siren including yelp and wail oscillators, means for mixing the signals from the yelp and wail oscillators, and an amplifier output circuit for broadcasting the mixed yelp and wail signals. The wail oscillator is adapted to operate automatically or may be operated manually by means of a push button or from remote switching means. The wail oscillator may also be switched to operate with a siren sound or a horn sound having a variable pitch. The amplifier output circuit is also utilized as an output circuit for a variable volume microphone or radio input signal thereto. Additional amplifier structure for increasing the output of the electronic siren is also provided in accordance with the invention.In operation, the electronic siren will provide a microphone or radio output, a manually selected automatic siren or horn sound output from the wail oscillator, the output of both the wail and yelp oscillators simultaneously, or the output of the yelp oscillator.
    Type: Grant
    Filed: May 15, 1974
    Date of Patent: February 21, 1978
    Inventor: Richard M. Sheff