Patents by Inventor Thomas F. Caldwell

Thomas F. 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).

  • Disposable litter tray
    Patent number: 4846105
    Abstract: Cat litter is packaged and sold in a rectangular carton made of cardboard and having two opposing end flaps and two opposing side flaps. When opened, the flaps form upright side walls and enable the carton to be used as a litter tray. A reusable pastic collar is adapted to slip over the flaps to hold the flaps open and to rigidify the carton during use.
    Type: Grant
    Filed: May 27, 1987
    Date of Patent: July 11, 1989
    Inventor: Thomas F. Caldwell