Patents by Inventor Frank S. Boxall

Frank S. Boxall 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).

  • Rearrangeable digital signal space division switching system
    Patent number: 4804956
    Abstract: A digital signal space division switching system in which signal blocking to new connections is avoided by rearranging existing connections. The rearrangement is accomplished without disturbing existing traffic and without requiring alternate paths to temporarily support existing traffic on rearranged signal paths. Multiple rearrangements are executed simultaneously.
    Type: Grant
    Filed: March 31, 1986
    Date of Patent: February 14, 1989
    Assignee: General Signal Corporation
    Inventor: Frank S. Boxall
  • Hybrid circuit using current mirror circuits
    Patent number: 4203012
    Abstract: A direct coupled transformerless hybrid for providing signal conversion between a balanced bidirectional transmission path and separate incoming and outgoing unidirectional transmission paths, for providing direct current to the bidirectional transmission path, for suppressing longitudinal mode signals originating in the bidirectional transmission path, and for providing signal balance to suppress transmission of reflected echoes from the incoming unidirectional transmission path to the outgoing unidirectional transmission path.
    Type: Grant
    Filed: July 10, 1978
    Date of Patent: May 13, 1980
    Inventor: Frank S. Boxall
  • Multi-channel differential pulse code modulation system
    Patent number: 4039948
    Abstract: A multi-channel differential pulse code modulation system providing communication between a plurality of analog signal sources and corresponding signal sinks employing time shared differential pulse code modulation encoders and decoders.
    Type: Grant
    Filed: June 19, 1974
    Date of Patent: August 2, 1977
    Inventor: Frank S. Boxall
  • Central office switching system with remote line switch
    Patent number: 4038498
    Abstract: A telephone subscriber system in which a concentrating portion of the central office telephone switching network is remotely located and connects to the remainder of the switching network at the central office via concentrated voice transmission paths and via multichannel data links which forward control and status signals between the two portions of the switching network.
    Type: Grant
    Filed: April 12, 1976
    Date of Patent: July 26, 1977
    Inventor: Frank S. Boxall
  • Hybrid circuit
    Patent number: 4004109
    Abstract: A direct coupled transformerless hybrid for providing signal conversion between a balanced bidirectional transmission path and a pair of unbalanced unidirectional transmission paths, for providing direct current to the bidirectional transmission path, for suppressing longitudinal mode signals supplied by the bidirectional transmission path, and for providing signal balance to suppress transmission of reflected echoes from the incoming unidirectional transmission path to the outgoing unidirectional transmission path.Of the several embodiments disclosed each includes a plurality of current mirror circuits, some of which include elements of complementary conductivity type to the elements of the remaining current mirror circuits. Each current mirror circuit has a voltage supply terminal, an input terminal, at least one output terminal, and means for supplying a current to the output terminal proportional to the current at the input terminal.
    Type: Grant
    Filed: May 9, 1975
    Date of Patent: January 18, 1977
    Inventor: Frank S. Boxall
  • Time shared delta modulation system
    Patent number: 3949298
    Abstract: A multi-channel delta modulation system providing communication between a plurality of analog signal sources and corresponding signal sinks employing a time shared delta modulation encoder and decoder.
    Type: Grant
    Filed: February 22, 1974
    Date of Patent: April 6, 1976
    Inventor: Frank S. Boxall