Patents by Inventor W. Fred Lettau

W. Fred Lettau 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).

  • Tapered block thickness gauge
    Patent number: 4107849
    Abstract: A gauge for measuring the rate of taper and the radius of the inside surface of a tapered, arcuate brake block has a base plate which pivotally mounts a swing arm with an indicator for visually reading the variation of the radius of the internal surface from a specified radius. The gauge also has a pair of rest bars mounted on the base plate to support the brake block at the specified radius at first and second measuring points. The indicator is swept over the brake block to detect variations of the inside brake block surface from the specified radius.
    Type: Grant
    Filed: June 10, 1977
    Date of Patent: August 22, 1978
    Assignee: Abex Corporation
    Inventor: W. Fred Lettau