Automatic steering system

Claim 2

For a tractor that is usually operated to travel in a longitudinal direction and has a steerable ground engaging wheel and a hydrostatic steering system that includes a two-way piston cylinder combination connected to a steerable wheel and a first hydraulic circuit for applying fluid under pressure to the cylinder and return fluid from the cylinder in response to the manual steering of the tractor, said first hydraulic circuit including a source of fluid under pressure, and hydraulic lines connected to the opposite ends of the cylinder, an automatic steering system that includes a second hydraulic circuit having pressure line means connected to said source, a return first line, a second line connected to one of the said lines of the first hydraulic circuit, a third line connected to the other of the said lines of the first hydraulic circuit, and operatable control valve means movable between a first position blocking fluid flow from the pressure line means to either of the second and third lines, a second position fluidly connecting the pressure line means to the second line and the third line to the first line, and a third position fluidly connecting the pressure line means to the third line and the second line to the first line, and guide means mounted on the tractor for following a furrow or the like for operating the control valve means between its positions to control the flow of fluid through the first, second and third lines and thereby through the said line of the first hydraulic circuit to automatically steer the tractor.

Claim 3

The apparatus of claim 1 further characterized in that said control valve means comprises a four-way rotary control valve.

Claim 4

The apparatus of claim 1 further characterized in that the above guide means includes a frame mounted on the tractor, a guide element to follow in a furrow or the like, guide arm means movably mounted on the frame for mounting the guide element for lateral movement relative the tractor, a tie rod having one end portion connected to the guide arm means for movement therewith and an opposite end portion, and means for connecting said opposite end portion to the control valve means for operating the valve means between its positions as the tie rod moves.

Claim 5

The apparatus of claim 3 further characterized in that the first mentioned guide means includes mounting means mounted on the frame for mounting the opposite end portion for slidably and pivotal movement relative the frame and resilient means mounted on the tie rod for resiliently urging the tie rod to slide relative the mounting means to a datum position relative thereto to thereby resiliently retain the guide arm in a datum lateral position relative the tractor.

Claim 6

The apparatus of claim 4 further characterized in that mounting means includes a tubular portion having the tie rod end portion slidably extended therethrough, a first and second collar mounted on the tie rod opposite end portion in fixed positions spaced from the tubular portion and on opposite sides thereof, a first spring on the tie rod bearing against the first collar and the tubular portion and a second spring on the tie rod bearing against the second collar and the tubular portion.

Claim 7

The apparatus of claim 5 further characterized in that the guide arm means includes a guide arm having a first end portion mounting the guide element and a second end portion, universal joint means for mounting the guide arm second end portion on the frame for pivotal movement about a generally vertical axis and a horizontal axis and ram means mounted on the frame and connected to the guide arm for selectively pivoting the guide arm about said horizontal axis to move the guide element between a ground engaging position and an elevated position relative thereto.

Claim 8

The apparatus of claim 6 further characterized in that said mounting means includes universal joint means for mounting the tubular portion on the frame and that the tie rod one end portion is pivotally connected to the guide arm.

Claim 9

The apparatus of claim 6 further characterized in that said ram means includes a ram cylinder, and that said pressure line means includes a fourth line connected to the pressure source, a fifth line connected to the first control valve means for applying fluid under pressure thereto, a return sixth line and second line means connected to the ram cylinder for conducting fluid to and from the ram cylinder, and second control means connected to the fourth, fifth and sixth lines and the second line means for selectively blocking flow of fluid under pressure from the fourth line to the sixth line while connecting the fourth line to the second line means for applying fluid under pressure to the ram cylinder for moving the guide arm to the guide arm elevated position and a second position connecting the second line means to the return line and the fourth line to the sixth line, said second control valve means in its second and third positions fluidly connecting the sixth line to the second line and third line respectively.

Claim 10

For a tractor having a steerable ground engaging wheel and a hydrostatic steering system that includes a two-way piston cylinder combination connected to the steerable wheel for turning it to steer the tractor, and a manually controlled first hydraulic circuit for applying fluid under pressure to the cylinder and return fluid from the cylinder in response to manual steering of the tractor, said first circuit including a source of fluid under pressure, a first line connected to one end of the cylinder and a second line connected to the other end of the cylinder, an automatic steering system that includes a guide element, a frame connected to the tractor, means for mounting the guide element on the frame for vertical movement between a ground engaging position and an elevated position and lateral movement independent of the vertical movement, ram means mounted on the frame and connected to the guide element mounting means, first control valve meanS fluidly connected to said first circuit and operable between a first position for applying fluid under pressure to either of the first and second lines, a second position for applying fluid under pressure to the first line and return fluid from the second line and a third position for applying fluid under pressure to the second line and return fluid from the first line, control means connected to the guide means and the first control valve means for operating the first control valve means between its position in response to the movement of the guide means when the guide element moves laterally, and manually operated second control valve means connected to said circuit, said first control valve means and said ram means and operable between a first position applying fluid under pressure from the pressure source to the first control valve means to pass therethrough when the first control valve means is in either of its second and third positions while blocking the flow of fluid under pressure to said ram means and a second position blocking the flow of fluid under pressure to flow through the first control valve means to either of the first and second lines and applying fluid under pressure to the ram means for moving the guide means to elevate the guide element.

Claim 11

For a tractor having a steerable ground engaging wheel and a hydrostatic steering system that includes a two-way piston cylinder combination connected to the steerable wheel for turning it to steer the tractor, and a manually controlled first hydraulic circuit for applying fluid under pressure to the cylinder and return fluid from the cylinder in response to manual steering of the tractor, said first circuit including a source of fluid under pressure, a first line connected to one end of the cylinder and a second line connected to the other end of the cylinder, an automatic steering system that includes a guide element, a frame connected to the tractor, means for mounting the guide element on the frame for vertical movement between a ground engaging position and an elevated position and lateral movement independent of the vertical movement, ram means mounted on the frame and connected to the guide element mounting means, first control valve meanS fluidly connected to said first circuit and operable between a first position for applying fluid under pressure to either of the first and second lines, a second position for applying fluid under pressure to the first line and return fluid from the second line and a third position for applying fluid under pressure to the second line and return fluid from the first line, control means connected to the guide means and the first control valve means for operating the first control valve means between its position in response to the movement of the guide means when the guide element moves laterally, and manually operated second control valve means connected to said circuit, said first control valve means and said ram means and operable between a first position applying fluid under pressure from the pressure source to the first control valve means to pass therethrough when the first control valve means is in either of its second and third positions while blocking the flow of fluid under pressure to said ram means and a second position blocking the flow of fluid under pressure to flow through the first control valve means to either of the first and second lines and applying fluid under pressure to the ram means for moving the guide means to elevate the guide element.

Claim 12

The apparatus of claim 9 further characterized in that said first control valve means comprises a third line fluidly connected to the first line, a fourth line fluidly connected to the second line and a first valve operable between the first valve means positions and having separate ports fluidly connected to the third and fourth lines respectively, and that the second control valve means includes a second control valve operable between the second valve means positions and having at four separate ports, pressure fifth line fluidly connecting one of the second valve ports to the pressure source, a pressure sixth line fluidly connecting a second of the second valve ports to the first valve, a seventh line fluidly connecting a third of the second valve ports to the ram means and a return line connected to the first valve, a fourth of the second valve ports and to the first circuit.

Claim 13

The apparatus of claim 9 further characterized in that the first valve means includes a control valve and a lever for operating the valve between the first control valve means positions, that the control means for the guide means includes a tie rod having one end portion pivotally connected to the guide means to move therewith and a second end portion and means for connecting the second end portion to the lever to move the lever in the proper direction for operating the control valve between its positions to automatically steer the tractor when the guide element is tracking in a furrow or the like.

Claim 14

The apparatus of claim 11 further characterized in that the means connected to the second end portion includes means mounted on the frame for mounting the tie rod second end portion for slidably and pivotal movement relative the frame, and first and second resilient means mounted on the second end portion on opposite sides of the tie rod mounting means to resiliently urge the tie rod to a given slidable position relative the tie rod mounting means to thereby resiliently urge the guide means to a datum lateral position relative the tractor.

Claim 15

The apparatus of claim 12 further characterized in that the means for connecting the lever to the tie rod comprises a push-pull cable and that the first valve comprises a four-way rotary valve and that the guide element comprises a disc.

Claim 16

The apparatus of claim 12 further characterized in that the guide means comprises a generally longitudinally elongated guide arm having a first end portion, an intermediate portion and a second end portion and universal joint means for mounting the guide arm first end portion on the frame for pivotal movement about a vertical axis and a pivot axis at right angles to the vertical axis, said tie rod first end portion being connected to the intermeDiate portion for pivotal movement relative thereto about a generally vertical axis when the guide element is in a ground engaging position.

Claim 17

A tractor having a chassis, a ground engaging steerable wheel mounted on the chasis, a two-way piston cylinder combination, including a cylinder, connected to the steerable wheel for steering it, a manually operated steering wheel, a frame mounted on the chassis to extend laterally outwardly thereof, a generally longitudinally elongated guide arm having a first end portion and a second end portion, universal joint means for mounting the guide arm first end portion for pivotal movement about a generally vertical axis and a horizontal axis at about right angles to the direction of elongation of the guide arm, a ram connected to the guide arm for selectively pivoting the guide arm about said horizontal axis for varying the elevation of the second end portion, means for mounting the ram on the frame, a guide element for engaging the ground to follow a furrow or the like, means for mounting the guide element on the second end portion, a tie rod having one end pivotally connected to the guide arm intermediate its end portions to move with the guide arm and an opposite end portion, and an operable hydraulic circuit connected to said cylinder and said ram for applying fluid under pressure to the appropriate end of the cylinder for steering the ground engaging wheel in response to manually steering and movement of the tie rod second end portion and selectively applying fluid under pressure to said ram for pivoting the guide arm about said horizontal axis.

Claim 18

A tractor having a chassis, a ground engaging steerable wheel mounted on the chasis, a two-way piston cylinder combination, including a cylinder, connected to the steerable wheel for steering it, a manually operated steering wheel, a frame mounted on the chassis to extend laterally outwardly thereof, a generally longitudinally elongated guide arm having a first end portion and a second end portion, universal joint means for mounting the guide arm first end portion for pivotal movement about a generally vertical axis and a horizontal axis at about right angles to the direction of elongation of the guide arm, a ram connected to the guide arm for selectively pivoting the guide arm about said horizontal axis for varying the elevation of the second end portion, means for mounting the ram on the frame, a guide element for engaging the ground to follow a furrow or the like, means for mounting the guide element on the second end portion, a tie rod having one end pivotally connected to the guide arm intermediate its end portions to move with the guide arm and an opposite end portion, and an operable hydraulic circuit connected to said cylinder and said ram for applying fluid under pressure to the appropriate end of the cylinder for steering the ground engaging wheel in response to manually steering and movement of the tie rod second end portion and selectively applying fluid under pressure to said ram for pivoting the guide arm about said horizontal axis.

Claim 19

The apparatus of claim 15 further characterized in that the ram includes a ram cylinder, that the frame includes an upright laterally outwardly of the frame, said upright having an upper end portion, and that the ram mounting means comprises means for mounting the cylinder on said upper end portion for pivotal movement about a generally vertical axis and a generally horizontal axis.

Claim 20

The apparatus of claim 15 further characterized in that there is provided tie rod mounting means for mounting the tie rod second end portion on the frame for slidable movement, and first and second resilient means on the tie rod respectively on opposite sides of the tie rod mounting means for resiliently urging the tie rod to a given slidable position relative the tie rod mounting means.

Claim 21

The apparatus of claim 15 further characterized in that said hydraulic circuit includes a reservoir, a pump fluidly connected to the reservoir, a pressure first line fluidly connected to the pump, a second line fluidly connected to one end of the cylinder, a third line fluidly connected to the second end of the cylinder, return line means connected to said reservoir, an operable first control valve having a neutral first position, a second position for fluidly connecting the first line to the second line and the third line to the return line means and a third position for fluidly connecting the first line to the third line and the second line to the return line means, means for connecting the steering wheel to the first valve for operating the first valve between its positions in response to turning the steering wheel and hydraulic circuit means fluidly connected to said lines and line means in parallel to the control valve for applying fluid under pressure to one of the second and third lines and return fluid from the other in response to movement of the tie rod moving with the guide arm about said vertical axis.

Claim 22

The apparatus of claim 18 further characterized in that the circuit means includes a second control valve having an inlet port fluidly connected to the first line, an outlet port fluidly connected to the return line means, and a ram port fluidly connected to the ram, and a valve member manually operable between a first position fluidly connecting the inlet port to the ram port and blocking fluid communication between the ram port and the return port, and a second position fluidly connectiNg the ram port to the return port and blocking fluid communication between the ram port and the inlet port.

Claim 23

The apparatus of claim 18 further characterized in that said circuit means includes fourth and fifth pressure and return lines fluidly connected to the second and third lines respectively, a pressure sixth line connected to said first line and control means for controlling the flow of fluid under pressure from the sixth line to the fourth and fifth lines respectively and the return of fluid from the fifth and fourth lines respectively to the return line means.

Claim 24

The apparatus of claim 20 further characterized in that the last mentioned control means includes a second control valve operable between a first position fluidly connecting the fourth line to the sixth line and the fifth line to the return line means, a second position fluidly connecting the fifth line to the sixth line and fourth line to the return line means and a neutral third position blocking fluid flow from the sixth line to either of the fourth and fifth lines, and means connected to the tie rod opposite end for operating the second control valve between its positions.

Claim 25

The apparatus of claim 21 further characterized in that said circuit means includes a third control valve having an inlet port and an outlet port forming part of the sixth line, a return line port fluidly connected to the return line means and a ram port fluidly connected to the ram, and a manually operated valve member movable between a position blocking fluid flow between the inlet and outlet ports while fluidly connecting the inlet port to the ram port and a second position fluidly connecting the inlet port to the outlet port and the ram port to the return port, and that a flow control is provided in the sixth line to restrict the flow of fluid therethrough to permit the steering through the operation of the first valve overriding the steering control provided through the operation of the second valve.

Claim 26

For a tractor having a steerable wheel, a two-way piston cylinder combination for steering the steerable wheel, a motor driven pump and a reservoir fluidly connected in series, a first line fluidly connected to the pump, a second line fluidly connected to one end of the cylinder, a third line fluidly connected to the reservoir, a fourth line fluidly connected to the other end of the cylinder, first operable valve means for selectively controlling the flow of fluid under pressure between the first line and one of the second and fourth lines and the return of fluid from the other of the fourth and second lines to the third line, and manually operated steering means for controlling the valve means, an automatic steering system that includes a fifth line fluidly connected to the first line, a sixth line fluidly connected to the second line, a seventh line for returning fluid to the reservoir, an eighth line fluidly connected to the fourth line, operable second valve means fluidly connected to the fifth through eighth lines that is operable between a first position to block fluid flow between any of the fifth through eighth lines, a second position to fluidly connect the fifth line to the sixth line and the seventh line to the eighth line, and a third position to fluidly connect the fifth line to the eighth line and the sixth line to the seventh line, and sensing means mounted on the tractor to follow a marked path as the tractor advances and operates the second valve means between its positions to control the flow of fluid in the fifth through eighth lines to and from the ends of the cylinder to maintain direction of travel of the tractor nearly parallel to the adjacent part of said path.

Claim 27

For a tractor having a steerable wheel, a two-way piston cylinder combination for steering the steerable wheel, a motor driven pump and a reservoir fluidly connected in series, a first line fluidly connected to the pump, a second line fluidly connected to one end of the cylinder, a third line fluidly connected to the reservoir, a fourth line fluidly connected to the other end of the cylinder, first operable valve means for selectively controlling the flow of fluid under pressure between the first line and one of the second and fourth lines and the return of fluid from the other of the fourth and second lines to the third line, and manually operated steering means for controlling the valve means, an automatic steering system that includes a fifth line fluidly connected to the first line, a sixth line fluidly connected to the second line, a seventh line for returning fluid to the reservoir, an eighth line fluidly connected to the fourth line, operable second valve means fluidly connected to the fifth through eighth lines that is operable between a first position to block fluid flow between any of the fifth through eighth lines, a second position to fluidly connect the fifth line to the sixth line and the seventh line to the eighth line, and a third position to fluidly connect the fifth line to the eighth line and the sixth line to the seventh line, and sensing means mounted on the tractor to follow a marked path as the tractor advances and operates the second valve means between its positions to control the flow of fluid in the fifth through eighth lines to and from the ends of the cylinder to maintain direction of travel of the tractor nearly parallel to the adjacent part of said path.

Claim 28

The apparatus of claim 23 further characterized in that a flow control is provided in the fifth line to restrict flow therethrough to permit manual steering overriding automatic steering, and that a pressure regulator is provided in the seventh line to block the complete drainage of fluid from the sixth and eighth lines when they Are respectively fluidly connected to the seventh line.