Patents by Inventor Edmund T. Klemmer

Edmund T. Klemmer 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).

  • Method and circuitry for encoding telephone ringing signals
    Patent number: 4477697
    Abstract: The method and apparatus encodes telephone ringing to identify both the origin and destination of a received call. The ring envelope of the ringing signal is divided into two segments. During the first segment, call origin information is encoded by varying the number of pulses or the pulse widths of a fixed frequency signal. Call destination information is encoded by time division multiplexing different frequencies into subsegments of the second segment.
    Type: Grant
    Filed: November 22, 1982
    Date of Patent: October 16, 1984
    Assignee: AT&T Bell Laboratories
    Inventors: Thomas H. Judd, Michael C. King, Edmund T. Klemmer, Martin H. Singer