Patents by Inventor Ralph R. Rigg

Ralph R. Rigg 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).

  • Refrigerator forced air condenser filter
    Patent number: 4047393
    Abstract: A refrigerator machinery compartment air filter for a forced air condenser operative to maintain the proper air flow over the heat transfer surfaces insuring efficient operation. The filter has two sections connected by a flexible hinge allowing for ready insertion and removal from the front of the compartment for ease of cleaning.
    Type: Grant
    Filed: October 8, 1976
    Date of Patent: September 13, 1977
    Assignee: General Motors Corporation
    Inventors: Robert S. Hanson, Ralph R. Rigg