Patents by Inventor Tom Walter Carlson

Tom Walter Carlson 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).

  • Citizens alarm system
    Patent number: 4040013
    Abstract: A combined police and fire alarm system has provision for voice communication between street corner boxes and a central station via existing telegraphic cables. The boxes automatically transmit identification signals to the central station upon being activated. The central station can check out the boxes by causing them to transmit their identification signals and an audio test signal.
    Type: Grant
    Filed: January 9, 1975
    Date of Patent: August 2, 1977
    Assignee: North American Philips Corporation
    Inventor: Tom Walter Carlson