Patents by Inventor Daniel T. Mather

Daniel T. Mather 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).

  • Publication number: 20030121256
    Abstract: In a fluid system, a source of pressurized fluid operably communicates with first and second actuators. First and second control valves control fluidly communicates with the first and second actuators. A first pressure compensating valve fluidly communicates with the first control valve and first actuator. A first signal conduit fluidly communicates with fluid flow being directed by the first control valve to the first pressure compensating valve and first actuator. A second pressure compensating valve fluidly communicates with the second control valve and second actuator. A second signal conduit fluid communicates with fluid flow being directed by the second control valve to the second pressure compensating valve and second actuator. A control signal pressure generated from a greater of a first signal pressure carried by the first signal conduit and a second signal pressure carried by the second signal conduit fluidly communicates with the first and second pressure compensating valves.
    Type: Application
    Filed: August 26, 2002
    Publication date: July 3, 2003
    Applicant: Caterpillar Inc.
    Inventor: Daniel T. Mather
  • Patent number: 6293181
    Abstract: A control system is provided with a float condition to permit a double acting hydraulic cylinder to freely extend or retract in response to external forces acting on the hydraulic cylinder. The system includes a pair of pilot operated poppet valves disposed between the opposite sides of the hydraulic cylinder and a directional control valve. The pilot condition is obtained by opening a pair of pilot operated control valves to vent the control chambers of the poppet valves to a tank through a pair of float check valves. The float check valves are operative to prevent higher pressure fluid from being transmitted from the tank to the control chambers of the poppet valves when a negative pressure occurs in the side of the hydraulic cylinder that is connected to the control chamber.
    Type: Grant
    Filed: September 21, 1999
    Date of Patent: September 25, 2001
    Assignee: Caterpillar Inc.
    Inventors: Thomas J. Hajek, Jr., Srikrishnan T. Tolappa, Daniel T. Mather
  • Patent number: 5546847
    Abstract: A hydraulic cylinder snubbing arrangement includes a pilot operated control valve having a predetermined snubbing position at which flow exhausted from a hydraulic cylinder actuating chamber must pass through a plurality of flow restricting orifices in a valve spool when the hydraulic cylinder is retracted to a predetermined position. The valve spool is shifted to the snubbing position automatically by reducing the fluid pressure in a pilot chamber at the end of the valve spool to a predetermined level so that a snubber spring device resiliently moves the spool from a lower or float position. By forcing the fluid to pass through the restricted flow path created by the orifices, the gravity induced velocity of the hydraulic cylinder is greatly reduced as the hydraulic cylinder approaches its end of stroke position.
    Type: Grant
    Filed: September 12, 1995
    Date of Patent: August 20, 1996
    Assignee: Caterpillar Inc.
    Inventors: Charles E. Rector, Steven R. Wells, Daniel T. Mather, Robin S. Arndt