Patents by Inventor Jack D. Gifford

Jack D. Gifford 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).

  • Metal detector apparatus utilizing controlled phase response to reject ground effects and to discriminate between different types of metals
    Patent number: 4486713
    Abstract: Metal detector apparatus includes a controlled phase responsiveness to allow operation with reduced ground effects while discriminating between different types of metals. A phase relationship is predetermined that will reject unwanted signals from mineralized ground and trash metals and will be responsive to the signals from desired metals. The algebraic relationship between two signals is determined so that only input signals falling within the desired algebraic relationship are used to provide an output signal.
    Type: Grant
    Filed: September 28, 1981
    Date of Patent: December 4, 1984
    Inventor: Jack D. Gifford