Patents by Inventor L. Duane Gregory

L. Duane Gregory 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).

  • Cordless telephone system
    Patent number: 4039760
    Abstract: A duplex voice communication link including controls therefor as provided between a Base Station connected directly to a telephone line of a telephone exchange and a Mobile Unit consisting of a small, compact cordless telephone instrument containing transmitter, receiver and control circuits powered by a rechargeable battery pack. A single logic tone is transmitted and detected for all logical control for ring signals, on-hook and off-hook signals and dial pulses.
    Type: Grant
    Filed: March 11, 1974
    Date of Patent: August 2, 1977
    Assignee: Teletronics United Inc.
    Inventors: L. Duane Gregory, Douglas G. Talley