Patents by Inventor Robert J. Schieferstein

Robert J. Schieferstein 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).

  • Patent number: 4197875
    Abstract: A ball check valve is described having a fluid port, a ball moveable toward and away from the port, a seating surface surrounding the port and an elastomeric sealing element. The seating surface has a conical annular surface extending radially outwardly away from the ball and an annular ridge between the port and the conical surface. The sealing element has an outer sealing surface for contacting the conical seating surface and an annular groove for receiving the seating surface ridge. On its ball side, it has an annular outer surface and an inner sealing surface for contacting the ball. A sealing element retainer contacts the outer portion of the elastomeric sealing element outer surface on its ball side to hold it in position.
    Type: Grant
    Filed: May 16, 1978
    Date of Patent: April 15, 1980
    Assignee: Liquid Metronics Incorporated
    Inventors: Robert J. Schieferstein, Enrique L. Kilayko