Patents by Inventor Douglas G. Williams

Douglas G. Williams 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: 6895748
    Abstract: A hydrostatic transmission including a pump, a motor, and a center section provided with a conduit through which the pump and motor are in fluid communication and a valve. The pump, motor and center section are disposed in a housing having a plurality of walls which at least partially define a sump, the conduit being in fluid communication with the sump through the valve when the valve is open. A hydraulic disconnect mechanism is provided which includes a substantially rigid first portion, and a second portion operatively engaged with the first portion and being at least partially resilient. The valve is operably engaged with and opened by the second portion in response to the first portion being in an engaged position, and the valve is not operably engaged with the second portion when the first portion is in a disengaged position.
    Type: Grant
    Filed: March 20, 2003
    Date of Patent: May 24, 2005
    Assignee: Tecumseh Products Company
    Inventors: Douglas G. Williams, C. Paul Cox, Kevin L. Johnson
  • Publication number: 20040182075
    Abstract: A hydrostatic transmission including a pump, a motor, and a center section provided with a conduit through which the pump and motor are in fluid communication and a valve. The pump, motor and center section are disposed in a housing having a plurality of walls which at least partially define a sump, the conduit being in fluid communication with the sump through the valve when the valve is open. A hydraulic disconnect mechanism is provided which includes a substantially rigid first portion, and a second portion operatively engaged with the first portion and being at least partially resilient. The valve is operably engaged with and opened by the second portion in response to the first portion being in an engaged position, and the valve is not operably engaged with the second portion when the first portion is in a disengaged position.
    Type: Application
    Filed: March 20, 2003
    Publication date: September 23, 2004
    Inventors: Douglas G. Williams, C. Paul Cox, Kevin L. Johnson
  • Publication number: 20040123594
    Abstract: A hydrostatic transmission including a fluid motor in communication with a variable displacement fluid pump having a first displacement rate and a second greater displacement rate, a pump block having at least one fluid conduit through which fluid flows from the pump to the motor, an external fluid sump, a cylindrical pintle fixed to the block having a first bleed hole and a second bleed hole in communication with the first bleed hole, and a ring in sliding engagement with the pintle and having a slot in selective communication with the second bleed hole. The conduit and the sump are in communication through the bleed holes and the slot at the first displacement rate, and the fluid conduit and the sump are out of fluid communication at the second displacement rate.
    Type: Application
    Filed: December 30, 2002
    Publication date: July 1, 2004
    Inventors: Douglas G. Williams, C. Paul Cox
  • Patent number: 6729443
    Abstract: A transaxle for a small utility vehicle or implement, including a casing, at least one rotatable shaft disposed in and extending from the casing, at least one brake disc rotatably fixed to the rotatable shaft for rotation therewith, and at least one braking mechanism with at least a portion of the braking mechanism being externally mounted on the casing proximate the rotatable shaft. The braking mechanism includes at least one friction puck disposed proximate the brake disc, and a brake shaft including a cam surface having a longitudinal edge, wherein the brake shaft has an engaged position in which the longitudinal edge is in operative engagement with the friction puck and the friction puck is in pressing engagement with the brake disc and a disengaged position in which the longitudinal edge is out of operative engagement with the friction puck.
    Type: Grant
    Filed: April 11, 2002
    Date of Patent: May 4, 2004
    Assignee: Tecumseh Products Company
    Inventors: Richard T. Ruebusch, Kevin L. Johnson, Douglas G. Williams, Phillip G. Ross
  • Publication number: 20020178708
    Abstract: A self-propelled, walk-behind implement including a body, an engine attached to the body and having an output shaft, ground-engaging drive wheels, and a transaxle. The transaxle includes a housing, a input shaft extending into the housing and selectively operatively engaged with the output shaft, an axle having an axis of rotation and extending through the housing, the drive wheels coupled to the axle, a rotatable driving member disposed within the housing and engaged with the input shaft, and a driven member disposed within the housing and driven by the driving member. The driven member has a first axial position along the axle in which the driven member is not engaging the axle and the axle is freely rotatable, and a second axial position in which the driven member is in operative engagement with the driving member and the axle and the input and output shafts are operatively engaged.
    Type: Application
    Filed: May 14, 2002
    Publication date: December 5, 2002
    Inventors: Douglas G. Williams, Kevin L. Johnson
  • Publication number: 20020179379
    Abstract: A transaxle for a small utility vehicle or implement, including a casing, at least one rotatable shaft disposed in and extending from the casing, at least one brake disc rotatably fixed to the rotatable shaft for rotation therewith, and at least one braking mechanism with at least a portion of the braking mechanism being externally mounted on the casing proximate the rotatable shaft. The braking mechanism includes at least one friction puck disposed proximate the brake disc, and a brake shaft including a cam surface having a longitudinal edge, wherein the brake shaft has an engaged position in which the longitudinal edge is in operative engagement with the friction puck and the friction puck is in pressing engagement with the brake disc and a disengaged position in which the longitudinal edge is out of operative engagement with the friction puck.
    Type: Application
    Filed: April 11, 2002
    Publication date: December 5, 2002
    Inventors: Richard T. Ruebusch, Kevin L. Johnson, Douglas G. Williams, Phillip G. Ross