Patents by Inventor Thomas L. Flack

Thomas L. Flack 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: 4460003
    Abstract: A coin presence sensing apparatus comprises one or more ringing electronic oscillator circuits at least some of which include an inductor having a dumbbell shaped core adjacent a coin passageway. A pulse generating circuit is provided to selectively pulse each oscillator circuit. After the oscillator is pulsed, it begins to oscillate. Coin proximity during the time the oscillating circuit oscillates is determined by comparing the output of the oscillating circuit with the output of an oscillating circuit having a reference inductor isolated from coins.
    Type: Grant
    Filed: August 21, 1981
    Date of Patent: July 17, 1984
    Assignee: Mars, Inc.
    Inventors: Elwood E. Barnes, Thomas L. Flack