Patents by Inventor Fred E. Clark, Jr.

Fred E. Clark, Jr. 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).

  • Echo suppressor with SF transmission and regeneration
    Patent number: 4115668
    Abstract: An interface unit for a four wire telephone circuit includes an echo suppressor. A filter circuit is connected to the transmit line drop side to detect voice and SF signals and to selectively couple a regenerated SF signal and the voice signal to the line side of the transmit line. A passive filter is selectively coupled to the receive side to attentuate voice echo but bypass SF signals.
    Type: Grant
    Filed: April 29, 1977
    Date of Patent: September 19, 1978
    Assignee: Harvey Hubbell Incorporated
    Inventors: Ambroz K. Skrovanek, Fred E. Clark, Jr.