Patents by Inventor Andrew R. Powell

Andrew R. Powell 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).

  • Method of reducing the adaption time in the cancellation of repetitive vibration
    Patent number: 4417098
    Abstract: A method of reducing the adaption time needed to adapt a synthetically generated secondary waveform so that it nulls a primary repetitive waveform (e.g. noise) from a source (1) of vibration, the secondary waveform generation (5) being synchronized by the source (1). The clarity and/or the amplitude of at least a part of the signal resulting from interaction between the primary and secondary waveforms is sensed (6) and used (7, 8) to reshape the secondary waveform. The invention finds application in the cancelling of repetitive vibrations (e.g. in quietening the driving cab of a vehicle).
    Type: Grant
    Filed: April 16, 1981
    Date of Patent: November 22, 1983
    Assignee: Sound Attenuators Limited
    Inventors: George B. B. Chaplin, Andrew R. Powell, Roderick A. Smith