Hydraulically operated vehicle

Claim 2

In a hydraulically operated wheeled vehicle including a hydraulic pump for supplying a varying rate of fluid flow, said pump including a rotatably mounted input shaft, said shaft being rotatable in a clockwise direction and counterclockwise direction, at least one hydraulic drive motor operatively connected to said pump and adapted to drive a wheel of said vehicle in a forward direction and a rearwaRd direction, the direction of said wheel drive being dependent upon the direction of rotation of the input shaft of said pump, means for driving said pump, and operator means for signalling a command input rotation to said pump input shaft, the improvement which comprises linkage means interposed between said signalling means and said pump input shaft, said linkage means comprising a lever arm mounted to said input shaft and adapted to rotate with said shaft about a shaft axis, said shaft and said lever arm having a neutral position, said lever arm being operatively connected to said signalling means, and means for varying the effective pivot point of said lever arm with respect to said input shaft so that the force required to rotate said input shaft in the clockwise direction is materially different from the force required to rotate said input shaft in the counterclockwise direction from the neutral position.

Claim 3

The improvement of claim 1 wherein said effective pivot point varying means comprises a bar having a first end and a second end, said bar being positioned near said input shaft and being pivotally mounted to said pump at one of said first and second ends, and pivot means operatively connected between said input shaft and said bar, said pivot means including a pair of bearings, respective ones of said bearings being positioned outboard and on opposite sides of said input shaft, one of said bearings abutting said bar as said input shaft is rotated clockwise from the neutral position and the other of said bearings abutting said bar as said shaft is rotated in a counterclockwise direction from the neutral position.

Claim 4

The improvement of claim 2 further characterized by centering means operatively connected between the other of said first and second ends of said bar and said pump, said centering means positioning said bar at the neutral position in the absence of any force stimulus on said input shaft.

Claim 5

The improvement of claim 3 wherein said operator signalling means comprises a foot pedal pivotally mounted to said vehicle.

Claim 6

The improvement of claim 3 wherein said pivot means comprises a support plate mounted to said input shaft, said bearing pair being mounted to said support plate on opposite sides of said shaft, at least an individual one of said bearing pair being in physical contact with said bar in all positions of said input shaft.

Claim 7

The improvement of claim 1 further characterized by a pair of hydraulic motors operatively connected to said pump and adapted to drive individual wheels of said vehicle, and a valve member axially aligned with said wheel motors, said valve member having two channels for fluid flow therein between respective ones of said wheel motors and said pump, and means for interconnecting said channels, said valve member including a block structure having two inputs and four output connections, said means for interconnecting said channels comprising a threaded member closing said interconnecting means in a first position of said threaded member.

Claim 8

A hydraulically operated vehicle comprising: a frame, said frame being supported by at least three wheels, at least two of said wheels being axially aligned on opposite sides of one end of said frame; a hydraulic distribution system axially aligned with said wheels for driving said wheels, said hydraulic distribution system comprising first and second drive motors hydraulically connected to a distribution valve member, said valve member being axially aligned with said drive motors; a pump operatively connected to said drive motors through said distribution valve member, said pump including a variable swash plate and a rotatable shaft operatively connected to said swash plate; means for driving said pump; means for signalling pump output direction operatively connected to said shaft; and means for requiring a first force signal for commanding a first pump output direction and for requiring a materially different second force siGnal for commanding a second pump output direction, said force requiring means being mounted to said pump and being operatively connected to said signalling means.

Claim 9

A hydraulically operated vehicle comprising: a frame, said frame being supported by at least three wheels, at least two of said wheels being axially aligned on opposite sides of one end of said frame; a hydraulic distribution system axially aligned with said wheels for driving said wheels, said hydraulic distribution system comprising first and second drive motors hydraulically connected to a distribution valve member, said valve member being axially aligned with said drive motors; a pump operatively connected to said drive motors through said distribution valve member, said pump including a variable swash plate and a rotatable shaft operatively connected to said swash plate; means for driving said pump; means for signalling pump output direction operatively connected to said shaft; and means for requiring a first force signal for commanding a first pump output direction and for requiring a materially different second force siGnal for commanding a second pump output direction, said force requiring means being mounted to said pump and being operatively connected to said signalling means.

Claim 10

The vehicle of claim 7 further characterized by means for automatically returning said pump to a neutral position in the absence of any force signal stimulus, said return means being operatively connected between said force requiring means and said pump.

Claim 11

The vehicle of claim 8 wherein said means for varying the force of the signal stimulus comprises a bar having a first end and a second end positioned adjacent but spaced from said shaft, said bar being attached to said pump at one of said first and said second ends, and means for controlling pump output direction, said output direction controlling means comprising a lever arm operatively connected to said shaft and pivot means operatively connected between said input shaft and said bar.

Claim 12

The vehicle of claim 9 wherein said distribution valve member comprises a block structure having two input channels and four output channels, each of said input channels being operatively connected to two opposite output channels, an interconnection channel between said four output channels, and a threaded member threadedly mounted in said interconnection channel between a first position closing said interconnection channel and a second position opening said interconnection channel, thereby permitting free wheel operation of said vehicle.

Claim 13

In a hydraulically operated wheeled vehicle including a hydraulic pump, at least two hydraulic motors operatively connected to said pump, said pump having an input shaft and a hydraulic output adapted to drive individual ones of a plurality of wheels of said vehicle, at least two of said wheels being aligned so as to define a wheel axis, means for driving the pump and operator means for signalling a command input to said input shaft, the improvement comprising a distribution valve member aligned with said wheel axis, said valve member having two channels for fluid flow therein between respective ones of said wheel motors and said pump, and means for interconnecting said channels, said valve member including a block structure having two input and four output connections, an interconnection channel between said four output channels and a threaded member threadedly mounted in said interconnection channel between a first position closing said interconnection channel and a second position opening said interconnection channel and allowing fluid flow between said four output channels, thereby permitting free wheel operation of said vehicle.

Claim 14

In a hydraulically operated wheeled vehicle including a hydraulic pump, at least two hydraulic motors operatively connected to said pump, said pump having an input shaft and a hydraulic output adapted to drive individual ones of a plurality of wheels of said vehicle, at least two of said wheels being aligned so as to define a wheel axis, means for driving the pump and operator means for signalling a command input to said input shaft, the improvement comprising a distribution valve member aligned with said wheel axis, said valve member having two channels for fluid flow therein between respective ones of said wheel motors and said pump, and means for interconnecting said channels, said valve member including a block structure having two input and four output connections, an interconnection channel between said four output channels and a threaded member threadedly mounted in said interconnection channel between a first position closing said interconnection channel and a second position opening said interconnection channel and allowing fluid flow between said four output channels, thereby permitting free wheel operation of said vehicle.

Claim 15

The improvement of claim 11 further characterized by means for varying the force of a signal stimulus required for signalling a command input to said input shaft operatively connected between said pump and said pump input shaft.

Claim 16

The improvement of claim 12 wherein said pump is further characterized by a variable swash plate operatively connected to said input shaft, and means for automatically returning said pump to a neutral position in the absence of any signal stimulus.

Claim 17

The improvement of claim 13 wherein said means for varying the force of a signal stimulus required for signalling a command input to said shaft comprises a bar having a first end and a second end, said bar being positioned adjacent but spaced from said input shaft and attached to said pump at one of said first and said second ends.

Claim 18

A hydraulically operated vehicle comprising: a frame, said frame being supported by at least three wheels, at least two of said wheels being axially aligned on opposite sides of one end of said frame; a hydraulic distribution system axially aligned with said wheels for driving said wheels, said hydraulic distribution system comprising first and second drive motors hydraulically connected to a distribution valve member; a pump operatively connected to said drive motors through said distribution valve member, said pump including a variable swAsh plate and a shaft operatively connected to said swash plate, the output of said pump being adapted to power said drive motors in a first direction of movement and a second direction of movement; means for driving said pump; means for signalling pump output direction operatively connected to said shaft, said direction signalling means comprising a lever arm operatively connected to said shaft, and pivot means operatively connected to said input shaft, said pivot means including first and second bearings positioned on opposite sides of said shaft; and means for varying the force of the signal stimulus required for commanding pump output direction mounted to said pump and operatively connected to said signalling means such that the first direction of movement of said drive motors requires a substantially greater force for the signal stimulus than the force required for the signal stimulus directing the second direction of movement of said drive motors, said force varying means comprising a bar having a first end and a second end, said bar being positioned adjacent, but spaced from said input shaft and rotatably attached to said pump at its first end, at least one of the bearings of said pivot means being in abutment with said bar in all positions of said swash plate.

Claim 19

A hydraulically operated vehicle comprising: a frame, said frame being supported by at least three wheels, at least two of said wheels being axially aligned on opposite sides of one end of said frame; a hydraulic distribution system axially aligned with said wheels for driving said wheels, said hydraulic distribution system comprising first and second drive motors hydraulically connected to a distribution valve member; a pump operatively connected to said drive motors through said distribution valve member, said pump including a variable swAsh plate and a shaft operatively connected to said swash plate, the output of said pump being adapted to power said drive motors in a first direction of movement and a second direction of movement; means for driving said pump; means for signalling pump output direction operatively connected to said shaft, said direction signalling means comprising a lever arm operatively connected to said shaft, and pivot means operatively connected to said input shaft, said pivot means including first and second bearings positioned on opposite sides of said shaft; and means for varying the force of the signal stimulus required for commanding pump output direction mounted to said pump and operatively connected to said signalling means such that the first direction of movement of said drive motors requires a substantially greater force for the signal stimulus than the force required for the signal stimulus directing the second direction of movement of said drive motors, said force varying means comprising a bar having a first end and a second end, said bar being positioned adjacent, but spaced from said input shaft and rotatably attached to said pump at its first end, at least one of the bearings of said pivot means being in abutment with said bar in all positions of said swash plate.

Claim 20

The vehicle of claim 15 further characterized by means for automatically returning said pump to a neutral position in the absence of any signal stimulus operatively connected between the second end of said bar and said pump.

Claim 21

The vehicle of claim 16 wherein said distribution valve member is axially aligned with said drive motors.

Claim 22

The vehicle of claim 17 wherein said distribution valve member comprises a block structure having two input channels and four output channels, each of said input channels being operatively connected to two opposite output channels, an interconnection channel between said four output channels and a member threadedly mounted in said interconnection channel between a first position closing said interconnection channel and a second position opening said interconnection channel, thereby permitting fluid flow between said four output channels within said block structure.