Patents by Inventor George F. Hafer

George F. Hafer 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).

  • Private automatic business exchange
    Patent number: 5070523
    Abstract: The invention interfaces a two-wire line to many smart terminals, modems or telephones only one of which is in use at a time. The invention is used by electric utilities in substations to automatically transfer stored data originating in the substation to a central control room.
    Type: Grant
    Filed: May 22, 1989
    Date of Patent: December 3, 1991
    Assignee: Da-Tel Research Co., Inc.
    Inventors: George F. Hafer, Lanham P. Rattan
  • Frequency shift demodulator
    Patent number: 5015961
    Abstract: The invention improves the ability of the FS demodulator-circuit of an FS digital transmission system so as to withstand noise with low error count. The invention uses two different types of all pass networks and a phase measuring circuit to average random noise and enhance the desired FS frequencies.
    Type: Grant
    Filed: August 3, 1990
    Date of Patent: May 14, 1991
    Assignee: Da-Tel Research Company, Incorporated
    Inventors: Robert E. Springer, George F. Hafer, Everett A. Gilbert