Patents by Inventor Erling T. Sund

Erling T. Sund 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).

  • Test arrangement for automatic number identification systems
    Patent number: 4278849
    Abstract: A testing arrangement for automatic number identification apparatus is disclosed in a step-by-step telephone system. The "M" leads which apply identification tones to the sleeves of calling lines are periodically scanned for trouble conditions. If an "M" lead is held busy more than a predetermined interval indicating a fault, the test arrangement interrupts the sleeve to release the line finder and the maintenance personnel are notified. The "M" lead is then available for identifying other lines.The test arrangement periodically tests itself by simulating faults on all "M" leads.
    Type: Grant
    Filed: November 19, 1979
    Date of Patent: July 14, 1981
    Assignee: Bell Telephone Laboratories, Incorporated
    Inventor: Erling T. Sund