Patents by Inventor Harold H. Holl

Harold H. Holl 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).

  • Breather cap
    Patent number: 4175671
    Abstract: A breather cap has a resilient element which is expanded radially by the movement of first and second plates toward one another. Air can pass through the breather cap and is filtered by a filter device provided in the breather cap.
    Type: Grant
    Filed: May 1, 1978
    Date of Patent: November 27, 1979
    Assignee: Caterpillar Tractor Co.
    Inventors: Harold H. Holl, Walter R. Hupe