Patents by Inventor Bobby Stilwell

Bobby Stilwell 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).

  • Ringing interface card for telephone test equipment
    Patent number: 4647724
    Abstract: The present invention is directed toward a new type of ringing interface card which overcomes the inability of known cards for testing multi-party service and which enable a technician to measure the ringing frequency and simultaneously to detect which of the tip and ring conductors receives the ringing signal.
    Type: Grant
    Filed: March 25, 1985
    Date of Patent: March 3, 1987
    Assignee: GTE Service Corporation
    Inventor: Bobby Stilwell