Patents by Inventor David H. Willis

David H. Willis 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).

  • Self drying pet litter box
    Patent number: 4696257
    Abstract: A self drying pet litter box includes a foraminous panel supported above the bottom of a box like container to facilitate circulation of air through particulate litter material supported on the panel.
    Type: Grant
    Filed: August 20, 1986
    Date of Patent: September 29, 1987
    Assignee: John F. Neary
    Inventors: John F. Neary, John T. Peddy, David H. Willis