Patents by Inventor Laurence R. Riddle

Laurence R. Riddle 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).

  • Patent number: 5394376
    Abstract: An apparatus for reducing acoustic radiation from an enclosure containing a fluid includes one or more vibration sensors in communication with surfaces of the enclosure. The vibration sensors feed signals corresponding to detected vibrations in the surface to a radiation filter. The radiation filter assigns weights to the signals and generates a summation signal which is then input to a control unit, with the summation signal ideally representing only those vibrations that will actually radiate from the enclosure. The control unit uses a reference signal and the summation signal to calculate a cancellation waveform to offset the cause of the detected vibrations. The cancellation signal is input to a fluid displacement unit which applies pressure oscillations to the fluid corresponding to the cancellation waveform.
    Type: Grant
    Filed: December 17, 1993
    Date of Patent: February 28, 1995
    Assignee: Martin Marietta Corporation
    Inventors: Laurence R. Riddle, John M. Sewell, Paul H. Kurtz