Patents by Inventor David D. Logan

David D. Logan 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: 9282410
    Abstract: An electro-dynamic loudspeaker transducer's motor structure includes a magnetic circuit having a pole with minimal reluctance that allows the use of larger magnets and thicker front plates, thus generating higher flux density in the voice coil gap. The lower reluctance is achieved by increasing the pole piece's outside diameter at all points outside of the voice coil gap and the area swept out by the voice coil at maximal inward excursion. Increasing the pole's diameter over a substantial amount of the pole's distally projecting length (but not extending into the magnetic gap), provides an increased cross sectional area and a reduced magnetic circuit reluctance.
    Type: Grant
    Filed: July 22, 2014
    Date of Patent: March 8, 2016
    Inventors: Timothy A. Gladwin, Jason B. Cochrane, David D. Logan
  • Publication number: 20150030199
    Abstract: An electro-dynamic loudspeaker transducer's motor structure includes a magnetic circuit having a pole with minimal reluctance that allows the use of larger magnets and thicker front plates, thus generating higher flux density in the voice coil gap. The lower reluctance is achieved by increasing the pole piece's outside diameter at all points outside of the voice coil gap and the area swept out by the voice coil at maximal inward excursion. Increasing the pole's diameter over a substantial amount of the pole's distally projecting length (but not extending into the magnetic gap), provides an increased cross sectional area and a reduced magnetic circuit reluctance.
    Type: Application
    Filed: July 22, 2014
    Publication date: January 29, 2015
    Inventors: Timothy A. GLADWIN, Jason B. Cochrane, David D. Logan