Patents by Inventor J. David Pratt

J. David Pratt 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).

  • Zero turn transaxle
    Patent number: 7328576
    Abstract: A transaxle comprised of a hydrostatic transmission mounted in a transmission housing and having a pair of hydraulic pumps and hydraulic motors operatively connected together through a center section mounted in the housing. First and second axle housings are mounted on opposite ends of the transmission housing, with output axles mounted in the axle housings and connected to the respective hydraulic motors.
    Type: Grant
    Filed: May 25, 2007
    Date of Patent: February 12, 2008
    Assignee: Hydro-Gear Limited Partnership
    Inventors: Thomas J. Langenfeld, Shane A. Deters, Daryl Smothers, J. David Pratt
  • Bypass mechanism for a hydraulic drive apparatus
    Patent number: 7225617
    Abstract: A hydraulic drive apparatus having a center section located in a housing includes a hydraulic pump and motor disposed thereon and in fluid communication with a hydraulic porting system in the center section. The pump is driven by an input shaft extending out of the housing and the motor drives an output shaft that is generally perpendicular to the input shaft. A bypass actuator extends into the center section perpendicular to both the input shaft and the output shaft. Rotation of the bypass actuator acts to lift the hydraulic motor from the center section to break the hydraulic interface between the hydraulic motor and the hydraulic porting system. The center section may include a second pump and motor with a second hydraulic porting system and a second bypass actuator.
    Type: Grant
    Filed: February 21, 2006
    Date of Patent: June 5, 2007
    Assignee: Hydro-Gear Limited Partnership
    Inventors: Thomas J. Langenfeld, Matthew C. Roney, Shane A. Deters, Daryl Smothers, J. David Pratt, Raymond Hauser
  • Zero turn transaxle
    Patent number: 7047736
    Abstract: A transaxle comprised of a hydrostatic transmission mounted in a transmission housing and having a pair of hydraulic pumps and hydraulic motors operatively connected together through a center section mounted in the housing. First and second axle housings are mounted on opposite ends of the transmission housing, with output axles mounted in the axle housings and connected to the respective hydraulic motors.
    Type: Grant
    Filed: December 9, 2004
    Date of Patent: May 23, 2006
    Assignee: Hydro-Gear Limited Partnership
    Inventors: Thomas J. Langenfeld, Matthew C. Roney, Shane A. Deters, Daryl Smothers, J. David Pratt, Raymond Hauser
  • Zero turn transaxle
    Patent number: 6843056
    Abstract: A transaxle comprised of a hydrostatic transmission mounted in a transmission housing and having a pair of hydraulic pumps and hydraulic motors operatively connected together through a center section mounted in the housing. First and second axle housings are mounted on opposite ends of the transmission housing, with output axles mounted in the axle housings and connected to the respective hydraulic motors.
    Type: Grant
    Filed: March 11, 2003
    Date of Patent: January 18, 2005
    Assignee: Hydro-Gear Limited Partnership
    Inventors: Thomas J. Langenfeld, Matthew C. Roney, Shane A. Deters, Daryl Smothers, J. David Pratt, Raymond Hauser