Patents by Inventor David A. Bierig

David A. Bierig 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).

  • Rotatable spar
    Patent number: 4503796
    Abstract: A rotatable spar apparatus for controlling and adjusting sail shape which includes a curved, rigid spar which is arranged to reverse its curvature when tacking. Additionally by controlling the degree of rotation it may be used as a draft control device.
    Type: Grant
    Filed: April 2, 1982
    Date of Patent: March 12, 1985
    Inventor: David A. Bierig