Patents by Inventor Douglas M. Gage

Douglas M. Gage 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: 5024140
    Abstract: The invention is directed to a hydraulic control mechanism for a work vehicle. The work vehicle is provided with a work implement that is operated by a hydraulic actuator. The positioning of the work actuator is controlled by a pilot control system that supplies a pilot control signal to the end caps of a main hydraulic control valve. The mechanism comprises two pressure sensing valves which control the flow of hydraulic fluid from a fixed displacement pump to move the hydraulic actuator, and the flow of hydraulic fluid from a variable displacement pump to hold the hydraulic actuator.
    Type: Grant
    Filed: October 30, 1989
    Date of Patent: June 18, 1991
    Assignee: Deere & Company
    Inventor: Douglas M. Gage
  • Patent number: 5018935
    Abstract: A check valve assembly having first and second check valves and an unseating spool is positioned between a control valve and a rotary motor. The unseating spool is elongated so that it continually contacts the valve elements of the check valves. The check valve hydraulically coupled to the higher pressure supply/return line drives the unseating spool against the valve element of the other check valve opening it and connecting the associated supply/return line having lower hydraulic pressure to reservoir through the direction control valve.
    Type: Grant
    Filed: November 9, 1989
    Date of Patent: May 28, 1991
    Assignee: Deere & Company
    Inventor: Douglas M. Gage
  • Patent number: 4949802
    Abstract: The present invention is directed to a mechanical hydraulic pressure dampening devices for use in a steering system of an articulated self-propelled work vehicle. The dampening devices are hydraulically positioned between the steering cylinders of the work vehicle and absorb hydraulic pressure spikes in the steering system. In the preferred embodiment, the pressure dampener comprises a pressure accumulator that is fluidly coupled to the steering cylinder by a shuttle check valve. The shuttle check valve shifts in response to a pressure spike so that it can be absorbed by the pressure accumulator. In a second embodiment, the pressure dampener comprises a cylinder having two pistons that are biased into a normal position by a spring extending between the pistons. Spaces are formed on either side of the pistons and are hydraulically coupled to the steering cylinders. A central space formed between the two pistons is hydraulically coupled to a sump return line.
    Type: Grant
    Filed: December 12, 1989
    Date of Patent: August 21, 1990
    Assignee: Deere & Company
    Inventor: Douglas M. Gage
  • Patent number: 4915186
    Abstract: The present invention is directed to a mechanical hydraulic pressure dampening devices for use in a steering system of an articulated self-propelled work vehicle. The dampening devices are hydraulically positioned between the steering cylinders of the work vehicle and absorb hydraulic pressure spikes in the steering system. In the preferred embodiment, the pressure dampener comprises a pressure accumulator that is fluidly coupled to the steering cylinder by a shuttle check valve. The shuttle check valve shifts in response to a pressure spike so that it can be absorbed by the pressure accumulator. In a second embodiment, the pressure dampener comprises a cylinder having two pistons that are biased into a normal position by a spring extending between the pistons. Spaces are formed on either side of the pistons and are hydraulically coupled to the steering cylinders. A central space formed between the two pistons is hydraulically coupled to a sump return line.
    Type: Grant
    Filed: October 25, 1988
    Date of Patent: April 10, 1990
    Assignee: Deere & Company
    Inventor: Douglas M. Gage
  • Patent number: 4898078
    Abstract: The present invention is directed to a hybrid hydraulic system for a work vehicle having both an open center hydraulic circuit and a close center hydraulic circuit. An internal combustion engine drives a fixed displacement pump and a variable displacement pump. The fixed displacement pump provides hydraulic fluid to the open center circuit which directs hydraulic fluid to a steering circuit and the working circuit through a priority valve. The variable displacement pump provides hydraulic fluid to the close center circuit which directs hydraulic fluid to a braking circuit and a pressure reduction circuit. The pressure reduction circuit directs hydraulic fluid to a pilot control system, a clutch cutoff and a differential lock out. Both pumps receive hydraulic fluid from a common sump and a common suction line. The braking circuit comprises two independent braking circuits.
    Type: Grant
    Filed: October 27, 1988
    Date of Patent: February 6, 1990
    Assignee: Deere & Company
    Inventors: Douglas M. Gage, Stuart L. Neagle
  • Patent number: 4838314
    Abstract: The secondary steering system comprises a structure to prevent the reverse flow of fluid in the fluid bypass path around the fluid meter and provide a supply line from the reservoir to the pressurized fluid line. The supply line supplies hydraulic fluid to the fluid meter of the controller when hydraulic pressure has been lost. The fluid meter can then be manually driven by the operator to supply pressurized hydraulic fluid to the steering cylinders.
    Type: Grant
    Filed: October 12, 1988
    Date of Patent: June 13, 1989
    Assignee: Deere & Company
    Inventor: Douglas M. Gage
  • Patent number: 4809586
    Abstract: The present invention is directed to a hybrid hydraulic system for a work vehicle having both an open center hydraulic circuit and a close center hydraulic circuit. An internal combustion engine drives a fixed displacement pump and a variable displacement pump. The fixed displacement pump provides hydraulic fluid to the open center circuit which directs hydraulic fluid to a steering circuit and the working circuit through a priority valve. The variable displacement pump provides hydraulic fluid to the close center circuit which directs hydraulic fluid to a braking circuit and a pressure reduction circuit. The pressure reduction circuit directs hydraulic fluid to a pilot control system, a clutch cutoff and a differential lock out. Both pumps receive hydraulic fluid from a common sump and a common suction line. The braking circuit comprises two independent braking circuits.
    Type: Grant
    Filed: September 11, 1987
    Date of Patent: March 7, 1989
    Assignee: Deere & Company
    Inventors: Douglas M. Gage, Stuart L. Neagle
  • Patent number: 4781219
    Abstract: A fluid controller (17) is disclosed for controlling the flow of fluid to a steering cylinder (19). The controller includes a fluid meter (51) and a valving arrangement (49) including a valve spool (65) and a sleeve (67). The valving (49) defines a main fluid path including a main variable flow control orifice (121), a variable flow control orifice (123), the fluid meter (51), the steering cylinder (19), and a variable flow control orifice (125). In accordance with the invention, the valving (49) defines a dampening fluid path including a variable dampening orifice (133), the dampening fluid path being in parallel with the main fluid path to dampen pressure spikes in the main fluid path. The size of the variable dampening orifice (133), and the flow therethrough, is a function of the relative displacement between the spool (65) and sleeve (67), whereby the timing and amount of the dampening flow and the relationship thereof to the gain curve of the main fluid path can be selected as desired.
    Type: Grant
    Filed: April 13, 1987
    Date of Patent: November 1, 1988
    Assignee: Eaton Corporation
    Inventors: Donald M. Haarstad, Douglas M. Gage
  • Patent number: 4625751
    Abstract: A hydraulic circuit includes as its major constituents a pump supplying hydraulic fluid to a main steering valve and to an auxiliary function valve through a priority valve. The priority valve allows the main steering valve to preempt the auxiliary function valve on demand. A secondary valve is provided to allow an accumulator to discharge hydraulic fluid to the main steering valve should the hydraulic circuit experience a loss of pressure and flow. Electrical circuit means are provided to warn the operator that the hydraulic circuit has lost pressure and flow.
    Type: Grant
    Filed: March 6, 1985
    Date of Patent: December 2, 1986
    Assignee: Deere & Company
    Inventor: Douglas M. Gage
  • Patent number: 4326558
    Abstract: A hydraulic fluid power system includes an accumulator which stores a reserve of pressure fluid at pump standby pressure. The charging and discharging of the accumulator is controlled by an emergency steering valve which is operable in response to a predetermined minimum fluid pressure outputted by the steering pump to discharge the stored fluid for emergency steering. The emergency steering valve also has components which serve as a pressure switch which is actuated to complete a circuit through an indicator light whenever the emergency steering valve moves to effect the discharge of the accumulator. The steering valve components are arranged so that premature actuation of the indicator light during pressure drops of short duration are avoided.
    Type: Grant
    Filed: November 24, 1980
    Date of Patent: April 27, 1982
    Assignee: Deere & Company
    Inventor: Douglas M. Gage
  • Patent number: 4303089
    Abstract: A hydraulic fluid power steering system includes an accumulator which stores a reserve of pressure fluid at pump standby pressure. The charging and discharging of the accumulator is controlled by an emergency steering valve which is operable in response to a predetermined minimum fluid pressure outputted by the steering pump to discharge the stored fluid for emergency steering. The emergency steering valve also has components which serve as a pressure switch which is actuated to complete a circuit through an indicator light whenever the emergency steering valve moves to effect the discharge of the accumulator.
    Type: Grant
    Filed: October 14, 1980
    Date of Patent: December 1, 1981
    Assignee: Deere & Company
    Inventors: Douglas M. Gage, Warren L. Thompson