Patents by Inventor Herbert R. Ratch

Herbert R. Ratch 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).

  • Heat exchanger
    Patent number: D309344
    Type: Grant
    Filed: December 12, 1988
    Date of Patent: July 17, 1990
    Inventors: Herbert R. Ratch, Margo B. Ratch, David E. Lumbert