Patents by Inventor Fred L. Laqua

Fred L. Laqua 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).

  • Bypass valve for a displacement pump
    Patent number: 4859155
    Abstract: A displacement pump bypass valve having an integral pressure modulator in a piston of the valve, the piston located in a bore formed through the pump housing between the pump inlet and pump outlet, the piston having an internal, cylindrical expansion chamber which fluidly communicates with the pump outlet via an opening formed through one end of the piston. A modulator disc is located in the expansion chamber for axial movement therein to vary the expansion chamber volume, and a spring in the expansion chamber urges the modulator disc toward the opening in the expansion chamber.
    Type: Grant
    Filed: October 21, 1987
    Date of Patent: August 22, 1989
    Assignee: Great Plains Industries, Inc.
    Inventor: Fred L. Laqua
  • Gear-pump assembly for liquid products
    Patent number: D308209
    Type: Grant
    Filed: November 17, 1987
    Date of Patent: May 29, 1990
    Assignee: Great Plains Industries, Inc.
    Inventors: Fred L. Laqua, Robert E. Hall
  • Pump assembly for high-viscosity liquid products
    Patent number: D308385
    Type: Grant
    Filed: November 10, 1987
    Date of Patent: June 5, 1990
    Assignee: Great Plains Industries, Inc.
    Inventors: Frank J. Russold, Fred L. Laqua
  • Piston hand pump for fuel, oil and chemicals
    Patent number: D308567
    Type: Grant
    Filed: November 10, 1987
    Date of Patent: June 12, 1990
    Assignee: Great Plains Industries, Inc.
    Inventors: Frank J. Russold, Fred L. Laqua