Patents by Inventor Alan H. Purdy

Alan H. Purdy 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).

  • Acoustically non-resonant pipe
    Patent number: 6364055
    Abstract: A non-resonant pipe assembly comprised of two acoustical pipe paths in phase opposition. One pipe path by its physical presence will act as a half wave. The other pipe path is longer than the first by an odd integer multiple of the first path.
    Type: Grant
    Filed: September 26, 2000
    Date of Patent: April 2, 2002
    Inventor: Alan H. Purdy