Patents by Inventor Duaine E. Smith

Duaine E. Smith 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).

  • Cat litter box
    Patent number: D246392
    Type: Grant
    Filed: July 21, 1975
    Date of Patent: November 15, 1977
    Inventor: Duaine E. Smith