Patents by Inventor Joan E. Polsen

Joan E. Polsen 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).

  • Animal litter box liner
    Patent number: 5121712
    Abstract: An animal litter box liner of flexible, sheet-like material is provided with holes of an appropriate size and location for allowing clean, dry litter to sift therethrough while simultaneously retaining clumps of urine-soiled litter and feces within the liner as it is lifted from a litter pan.
    Type: Grant
    Filed: July 2, 1991
    Date of Patent: June 16, 1992
    Assignee: Alfa-Pet, Inc.
    Inventors: Benjamin M. Schulein, Jr., Joan E. Polsen