Patents by Inventor Richard Janis Drysdale

Richard Janis Drysdale 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).

  • Apparatus for acoustic loading of a diaphragm
    Patent number: 7639830
    Abstract: An apparatus acoustic loading of a diaphragm is disclosed. The apparatus comprises a rear face having a shape corresponding to a shape of a compression side of the diaphragm, a front face opposite to the rear face along an axis of symmetry, and a plurality of voids formed between the rear face and the front face. The plurality of voids are arranged so that their intersection with rear face forms a plurality of inlets, the plurality of inlets defining a higher compression ratio in the proximity of a voice coil compared to a compression ratio defined in at least a portion of the remaining area of the diaphragm.
    Type: Grant
    Filed: March 2, 2006
    Date of Patent: December 29, 2009
    Assignee: Cogent True-To-Life Loudspeakers, Incorporated
    Inventors: Stephen Frederick Schell, Richard Janis Drysdale