Patents by Inventor Francis E. Caldwell

Francis E. Caldwell 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).

  • Patent number: D262759
    Type: Grant
    Filed: October 2, 1978
    Date of Patent: January 26, 1982
    Inventors: Francis E. Caldwell, Robert E. Hagan