Patents by Inventor Jeffrey R. Girard

Jeffrey R. Girard 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).

  • Hydraulic gravitational load energy recuperation
    Patent number: 7249457
    Abstract: A hydraulic system has gravitional load energy recuperation by opening a recuperation piloted valve with a pilot pressure supplied by a hydraulic pump so as to drive a recuperation hydraulic motor with a source of fluid pressurized by gravity from the load. The recuperation hydraulic motor drives the mechanical drive train of the prime mover that drives the pump that supplies the load, and other pumps that supply other loads.
    Type: Grant
    Filed: February 16, 2006
    Date of Patent: July 31, 2007
    Assignee: Timberjack Inc.
    Inventors: Calin L. Raszga, Ulf Bergquist, Jeffrey R. Girard
  • Anti-stall pilot pressure control system for open center systems
    Patent number: 7165397
    Abstract: A hydraulic control system has a pilot pressure supply circuit that applies a pressure differential dependent on engine speed to opposite sides of an anti-stall valve to turn off the pilot flow when the pressure differential falls below a certain value, resulting in holding the positions of the hydraulic devices being controlled until engine speed recovers.
    Type: Grant
    Filed: November 9, 2004
    Date of Patent: January 23, 2007
    Assignee: Timberjack, Inc.
    Inventors: Calin L. Raszga, Jeffrey R. Girard, Ulf Bergquist