Patents by Inventor Joseph F. Pertz

Joseph F. Pertz 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).

  • Trench shield assembly
    Patent number: 5277522
    Abstract: A trench shield has a pair of upright shields laterally spaced from each other with spreaders. Each shield has a frame supporting side walls and a horizontal earth penetrating blade. A pounding rail is releasably mounted on a channel top member of the frame. The pounding rail is an inverted channel member located in the channel of the top member. Rods secured to opposite sides of the pounding rail cooperate with the top member to retain the pounding rail on the top member and allow removal of the pounding unit from the top member. Collars secured to opposite ends of the frame accommodate the spreaders.
    Type: Grant
    Filed: June 2, 1992
    Date of Patent: January 11, 1994
    Assignee: Empire Manufacturing, Inc.
    Inventor: Joseph F. Pertz