Patents by Inventor Robert L. Duke

Robert L. Duke 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: 5324001
    Abstract: A sewage transfer system connecting the sewer outlet of a recreational vehicle to a remote sewer collection inlet that include a primary sewer line to connect the vehicle sewer outlet; an L-shape rigid pipe associated with the primary sewer line; and a hub, washer and clamping device to connect the L-shaped rigid pipe in a gas-tight and water-tight connection to the sewer inlet.
    Type: Grant
    Filed: November 2, 1993
    Date of Patent: June 28, 1994
    Inventor: Robert L. Duke
  • Patent number: 5083758
    Abstract: A plumbing tool having a suction producing effect allows for the convenient installation of plumbing components which are mounted on barriers such as within sinks which cannot be conveniently held in place by a lone individual during installation. The suction device acts as an extra "band" to allow the plumber to install and assemble components on opposite sides of sinks in a quick, safe efficient manner.
    Type: Grant
    Filed: February 15, 1990
    Date of Patent: January 28, 1992
    Inventor: Robert L. Duke
  • Patent number: 4844121
    Abstract: A temporary sewage line assembly is provided for an RV or other vehicles which may be utilized in a variety of hook ups. The assembly includes an elongated, reducing connector, a wash outlet on the connector, a telescoping conduit which pivotally attaches to the connector and a downspout for fitting within a stationary sewer line. The sewage assembly is formed from a rigid plastic which is constructed not to leak and which can be easily cleaned after use and disassembled.
    Type: Grant
    Filed: October 12, 1988
    Date of Patent: July 4, 1989
    Inventor: Robert L. Duke
  • Patent number: D306896
    Type: Grant
    Filed: October 22, 1987
    Date of Patent: March 27, 1990
    Inventor: Robert L. Duke
  • Patent number: D311315
    Type: Grant
    Filed: November 13, 1987
    Date of Patent: October 16, 1990
    Inventor: Robert L. Duke
  • Patent number: D317643
    Type: Grant
    Filed: December 4, 1989
    Date of Patent: June 18, 1991
    Inventor: Robert L. Duke
  • Patent number: D400769
    Type: Grant
    Filed: June 24, 1996
    Date of Patent: November 10, 1998
    Inventor: Robert L. Duke