Patents by Inventor Stephen C. Frantz

Stephen C. Frantz 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).

  • Housing for a rotary hydraulic unit with a servo piston
    Patent number: 6715997
    Abstract: A variable displacement hydraulic power unit has a housing and a rotating piston block with a rotatable axis and a servo piston bore having a reciprocal piston therein with the bore extending in a direction parallel to the rotatable axis of the rotating piston block. The housing and servo piston each have adjacent open ends. A single integral cover is attached to the housing to cover close and close the open ends of both the housing and the piston bore.
    Type: Grant
    Filed: April 19, 2002
    Date of Patent: April 6, 2004
    Assignee: Sauer-Danfoss Inc.
    Inventors: Stephen C. Frantz, Robert J. Klinkel
  • Control system for hydrostatic pump
    Patent number: 6640687
    Abstract: A non-feedback proportional system is provided to achieve desired operating characteristics which will allow the control of a hydrostatic transmission to closely approximate the control performance of a displacement feedback control system by establishing certain parameters relating to (1) the servo spring rate; (2) the valve plate index; (3) valve plate crossport/trap; (4) valve plate porting geometry; (5) swashplate offset; and (6) piston bore volume.
    Type: Grant
    Filed: August 9, 2002
    Date of Patent: November 4, 2003
    Assignee: Sauer-Danfoss Inc.
    Inventors: Stephen C. Frantz, Shannon D. Carver, Craig C. Klocke, Dennis M. Greene
  • Axial servo control
    Publication number: 20020157530
    Abstract: A variable displacement hydraulic power unit has a housing and a rotating piston block with a rotatable axis and a servo piston bore having a reciprocal piston therein with the bore extending in a direction parallel to the rotatable axis of the rotating piston block. The housing and servo piston each have adjacent open ends. A single integral cover is attached to the housing to cover close and close the open ends of both the housing and the piston bore.
    Type: Application
    Filed: April 19, 2002
    Publication date: October 31, 2002
    Applicant: Sauer-Danfoss Inc.
    Inventors: Stephen C. Frantz, Robert J. Klinkel