Patents by Inventor James W. Maddock

James W. Maddock 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).

  • Pressure transducer with capacitor pick-up means
    Patent number: 4084439
    Abstract: A pressure transducer includes an electromagnetic drive coil which vibrates a thin walled cylinder at a natural vibrational mode. A capacitor unit senses the vibrational frequency of the cylinder and gives an output signal corresponding to the pressure differential between a fluid contained within the cylinder and a vacuum reference that is maintained adjacent to the exterior surface of the cylinder. Electric heaters maintain a constant operating temperature of the transducer.
    Type: Grant
    Filed: January 3, 1977
    Date of Patent: April 18, 1978
    Assignee: King Radio Corporation
    Inventors: Robert D. Teter, James W. Maddock, Paul L. Rothers