Patents by Inventor Donald Brittain

Donald Brittain 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).

  • Electronic gating control for manual telephone switchboard
    Patent number: 4819262
    Abstract: A gating circuit for operation in conjunction with a manual cord telephone switchboard to service multiple operational modes of a subscriber telephone connected for telephone communication to a central office. In one mode, an internal intercom connection is established between the subscriber telephone and the switchboard. In a second mode a secretarial service connection is established allowing direct communication between the switchboard and the central office. A ring detection circuit detects when the subscriber telephone has been rung from the central office.
    Type: Grant
    Filed: October 28, 1987
    Date of Patent: April 4, 1989
    Assignee: Guardian Telecommunications Systems, Inc./VASA Engineering
    Inventors: Donald Brittain, Germain Boutin