Patents by Inventor Timothy Allen Callahan

Timothy Allen Callahan 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).

  • Train noise elimination system
    Patent number: 6619593
    Abstract: A two-piece, compact wireless railroad grade crossing motorist warning device comprising: a transmitter that transmits a non-audible analog radar beacon signal to be installed on a train and a receiver to receive the non-audible analog radar beacon to be installed on a motor vehicle. The receiver warns the motor vehicle operator of the train approaching a nearby railroad highway intersection without substantially increasing the ambient noise level in the surrounding community adjacent to the intersection.
    Type: Grant
    Filed: November 13, 2001
    Date of Patent: September 16, 2003
    Inventor: Timothy Allen Callahan