Patents by Inventor Walter K. Rolf

Walter K. Rolf 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: 7762923
    Abstract: A shift assisted brake control system for a power machine or vehicle is disclosed. In illustrated embodiments, the shift assisted brake control system employs a shift assisted brake sequence. In illustrated embodiments, the shift assisted brake sequence shifts an operating speed of a hydrostatic transmission or motor from a high speed to a low speed upon activation of a brake switch or device. This reduces impact or wear to the brake mechanism. In illustrated embodiments, the transmission or motor remains at the low speed for a pause period and following the pause period, the transmission or motor is shifted to the high speed.
    Type: Grant
    Filed: December 1, 2006
    Date of Patent: July 27, 2010
    Assignee: Clark Equipment Company
    Inventors: Scott N. Schuh, Cody E. Franzen, Gerald M. Berg, Jeret L. Hoesel, Walter K. Rolf, Spencer L. Mindeman, Timothy D. Hulm
  • Patent number: 7614223
    Abstract: A method of operating a hydraulic motor. In one embodiment, the method includes measuring a temperature of hydraulic fluid associated with the hydraulic motor and comparing the measured temperature of the hydraulic fluid to a first temperature threshold. The method also includes controlling an operational state of one or more hydraulic motor functions based at least partially on the comparison of the measured temperature of the hydraulic fluid and the first temperature threshold.
    Type: Grant
    Filed: March 30, 2007
    Date of Patent: November 10, 2009
    Assignee: Clark Equipment Company
    Inventors: Joseph A. St. Aubin, Jeret L. Hoesel, Walter K. Rolf
  • Patent number: 7571605
    Abstract: A system and method for substantially simultaneously shifting the speed of a plurality of multiple-speed motors that have shifting valves. The system and method includes substantially simultaneously applying an equal shifting force to all shifting valves, resisting shifting of all shifting valves with an equal biasing force arising from deflection of springs contained in springs chambers, and fluidly communicating all spring chambers with a common receptacle to equalize the pressure in all spring chambers.
    Type: Grant
    Filed: January 3, 2007
    Date of Patent: August 11, 2009
    Assignee: Clark Equipment Company
    Inventors: Joseph A. St. Aubin, Jeret L. Hoesel, Walter K. Rolf
  • Publication number: 20080236153
    Abstract: A method of operating a hydraulic motor. In one embodiment, the method includes measuring a temperature of hydraulic fluid associated with the hydraulic motor and comparing the measured temperature of the hydraulic fluid to a first temperature threshold. The method also includes controlling an operational state of one or more hydraulic motor functions based at least partially on the comparison of the measured temperature of the hydraulic fluid and the first temperature threshold.
    Type: Application
    Filed: March 30, 2007
    Publication date: October 2, 2008
    Inventors: Joseph A. St. Aubin, Jeret L. Hoesel, Walter K. Rolf
  • Publication number: 20080161152
    Abstract: A system and method for substantially simultaneously shifting the speed of a plurality of multiple-speed motors that have shifting valves. The system and method includes substantially simultaneously applying an equal shifting force to all shifting valves, resisting shifting of all shifting valves with an equal biasing force arising from deflection of springs contained in springs chambers, and fluidly communicating all spring chambers with a common receptacle to equalize the pressure in all spring chambers.
    Type: Application
    Filed: January 3, 2007
    Publication date: July 3, 2008
    Applicant: CLARK EQUIPMENT COMPANY
    Inventors: Joseph A. St. Aubin, Jeret L. Hoesel, Walter K. Rolf