Pick-up-type drawbar assembly

Claim 2

A drawbar assembly in combination with a tractor having a normal direction of travel, comprising: a drawbar extending in the normal direction of travel; vehicle hitch-engaging means carried by said drawbar; connecting means securing said drawbar to said tractor for movement between first and second positions wherein said hitch-engaging means is respectively disposed in a raised towing condition and a lowered vehicle hitch-engaging condition, said second position being located downwardly and rearwardly from said first position; said connecting means including means for constrainingly guiding said hitch-engaging means along a smooth arcuate path which is concave, as viewed facing the rear of the tractor, and curves downwardly and rearwardly from the first to the second position of the hitchengaging means and power means for moving said drawbar between its first and second positions.

Claim 3

The invention defined in claim 1 wherein said connecting means include said power means and only two pivotal connections with said drawbar.

Claim 4

The invention defined in claim 1 wherein there is a transverse opening in said drawbar, locking means supported by said tractor and including a locking bolt disposed for reciprocable movement in and out of said opening when said drawbar is in said first position and said locking means further including powered actuating means for selectively shifting said locking bolt into and out of said opening.

Claim 5

The invention defined in claim 3 wherein said actuating means includes means for automatically inserting said locking bolt into said opening in response to said drawbar being located in said first position.

Claim 6

In combination with a tractor drawbar assembly of the type including a drawbar movable between a lowered vehicle hitch-engaging position and a raised transport position, a safety lock comprising: an opening in said drawbar; a locking bolt; a fluid chamber slidably receiving said bolt in piston fashion and being fixed to dispose said bolt for reciprocal movement into and out of said opening when said drawbar is in the transport position; means biasing said bolt toward one end of said chamber and out of engagement with said opening; fluid pressure supplying means including fluid passage means connected to said one end of said chamber; said fluid pressure supplying means further including means responsive to the drawbar reaching said transport position for causing the fluid pressure to rise above a predetermined level; a first one-way check valve in said fluid passage means operative for permitting flow into said one end of said chamber, for shifting said bolt against the bias means and into the opening, only when the fluid pressure in said passage means is above said predetermined level; means for selectively connecting said fluid pressure supplying means to exhaust and a second one-way check valve in said passage means operative for permitting fluid to exhaust from said one end of said chaMber to permit the bolt to be moved out of said opening by said bias means.

Claim 7

In combination with a tractor drawbar assembly of the type including a drawbar movable between a lowered vehicle hitch-engaging position and a raised transport position, a safety lock comprising: an opening in said drawbar; a locking bolt; a fluid chamber slidably receiving said bolt in piston fashion and being fixed to dispose said bolt for reciprocal movement into and out of said opening when said drawbar is in the transport position; means biasing said bolt toward one end of said chamber and out of engagement with said opening; fluid pressure supplying means including fluid passage means connected to said one end of said chamber; said fluid pressure supplying means further including means responsive to the drawbar reaching said transport position for causing the fluid pressure to rise above a predetermined level; a first one-way check valve in said fluid passage means operative for permitting flow into said one end of said chamber, for shifting said bolt against the bias means and into the opening, only when the fluid pressure in said passage means is above said predetermined level; means for selectively connecting said fluid pressure supplying means to exhaust and a second one-way check valve in said passage means operative for permitting fluid to exhaust from said one end of said chaMber to permit the bolt to be moved out of said opening by said bias means.

Claim 8

The invention defined in claim 5 wherein said means responsive includes, at least one extensible and retractable hydraulic actuator having at least one work port and being operatively connected between the tractor and the drawbar for moving the drawbar from said lowered position to said raised position when fluid pressure is applied to said work port; said pressure supply means including pump means operatively connected for selectively supplying fluid under pressure to said work port; the actuator being of such size and of such location relative to the drawbar that the pressure developed in said work port, during raising of the drawbar, normally remains below said predetermined level; stop means for engaging said drawbar when said drawbar reaches said raised position and for stopping the movement of said actuator, the actuator being selected such that said stopping causes the pressure in the work port, and consequently the pressure applied by said pressure supply means, to increase above said predetermined level, whereby the locking bolt is automatically shifted into the opening when said drawbar reaches the raised position.

Claim 9

The invention defined in claim 6 wherein said locking bolt has a cylindrical head, and wherein said chamber is cylindrical and slidably receives said head; said fluid passage means including an inlet to the end of said chamber remote from said one end, the passage of said bolt interconnecting the fluid chamber portions at the opposite sides of said head, and an outlet from said one end of the chamber, and said first and second one-way check valves being located respectively in said passage and in said outlet.

Claim 10

The invention defined in claim 7 wherein a conduit interconnects said inlet and outlet.

Claim 11

The invention defined in claim 6 wherein said opening extends transversely through said drawbar and is elongated in the direction of travel of the tractor, whereby lost motion is provided between said drawbar and the locking bolt when the locking bolt is inserted in said opening, and said hydraulic actuator being positioned so as to cushion draft loads applied to said drawbar.

Claim 12

A drawbar assembly in combination with a tractor comprising: a drawbar; vehicle hitch-engaging means carried by said drawbar; connecting means securing said drawbar to said tractor for movement between first and second positions wherein said hitch-engaging means is respectively disposed in a raised towing condition and a lowered vehicle hitch-engaging position; power means for moving said drawbar between said first and second positions; a motive force connected to said power means and normally remaining below a first force level during raising of the drawbar from said second to said first position; means causing said motive force to increase above said first force level once said drawbar reaches said first position; a transverse opening being in said drawbar; locking means supported by said tractor including a locking bolt disposed for reciprocable movement into and out of said opening when said drawbar is in said first position; actuating means for automatically inserting said locking bolt into said opening when said drawbar is located in said first position; said actuating means being connected to said motive force and including means responsive only to forces above said first force level for causing said automatic insertion of said bolt.

Claim 13

A drawbar assembly in combination with a tractor comprising: a drawbar; vehicle hitch-engaging means carried by said drawbar; connecting means securing said drawbar to said tractor for movement between first and second positions wherein said hitch-engaging means is respectively disposed in a raised towing condition and a lowered vehicle hitch-engaging position; power means for moving said drawbar between said first and second positions; a motive force connected to said power means and normally remaining below a first force level during raising of the drawbar from said second to said first position; means causing said motive force to increase above said first force level once said drawbar reaches said first position; a transverse opening being in said drawbar; locking means supported by said tractor including a locking bolt disposed for reciprocable movement into and out of said opening when said drawbar is in said first position; actuating means for automatically inserting said locking bolt into said opening when said drawbar is located in said first position; said actuating means being connected to said motive force and including means responsive only to forces above said first force level for causing said automatic insertion of said bolt.

Claim 14

A drawbar assembly in combination with a tractor, comprising: a drawbar; vehicle hitch-engaging means carried by said drawbar; connecting means securing said drawbar to said tractor for movement between first and second positions wherein said hitch-engaging means is respectively disposed in a raised towing condition and a lowered vehicle hitch-engaging condition, said second position being located downwardly and rearwardly from said first position; said connecting means including power means for moving said drawbar between said first and secoNd positions; said power means including at least one extensible and retractable rod fixed for horizontal fore-and-aft movement; and said drawbar being in the form of a two-armed lever having one end pivotally connected to said rod whereby said one end of said drawbar will be moved in a straight line.

Claim 15

A drawbar assembly in combination with a tractor, comprising: a drawbar; vehicle hitch-engaging means carried by said drawbar; connecting means securing said drawbar to said tractor for movement between first and second positions wherein said hitch-engaging means is respectively disposed in a raised towing condition and a lowered vehicle hitch-engaging condition, said second position being located downwardly and rearwardly from said first position; said connecting means including power means for moving said drawbar between said first and secoNd positions; said power means including at least one extensible and retractable rod fixed for horizontal fore-and-aft movement; and said drawbar being in the form of a two-armed lever having one end pivotally connected to said rod whereby said one end of said drawbar will be moved in a straight line.

Claim 16

The invention defined in claim 11 wherein said connecting means includes at least one crank having one end pivotally connected intermediate the ends of said drawbar and having the other end mounted for vertical, fore-and-aft pivoting movement about a fixed transverse axis above said drawbar; said crank and said rod being positioned in such relationship to each other and to the drawbar that said hitch-engaging means will follow a curved path when said drawbar is moved between said first and second positions by respective extension and retraction of said rod.

Claim 17

The invention defined in claim 11 wherein said power means includes a pair of parallel-arranged extensible and retractable rods disposed for horizontal fore-and-aft movement; said drawbar being pivotally connected at its forward end to the forward end of said rods for relative pivotal movement about a transverse axis, said connecting means including a pair of parallel cranks, each having one end pivotally connected intermediate the ends of drawbar and having the other end mounted for vertical fore-and-aft pivoting movement about a fixed transverse axis above said drawbar; said cranks and said rods being positioned in such relationship to each other and to the drawbar that said hitch-engaging means will follow a curved path when the drawbar moves between said first and second positions by extension or retraction of said rods.

Claim 18

A drawbar assembly in combination with a tractor, comprising: a drawbar; vehicle hitch-engaging means carried by said drawbar; connecting means securing said drawbar to said tractor for movement between first and second positions wherein said hitch-engaging means is respectively disposed in a raised towing condition and a lowered vehicle hitch-engaging condition, said second position being located downwardly and rearwardly from said first position; said drawbar being mounted for movement in the longitudinal center plane of the tractor and said connecting means includes a pair of extensible and retractable hydraulic actuators fixed to the underside of the tractor in side-by-side fore-and-aft extending relationship at the opposite sides of said longitudinal center plane; the piston rods of said actuators extending forwardly and being pivotally connected at their forward ends to the forward end of said drawbar, at least one crank having one end pivotally connected intermediate the ends of said drawbar and having the other end mounted for vertical, fore-and-aft pivotal movement about a fixed transverse axis above said drawbar; said crank and said actuators being positioned in such relationship to each other and to the drawbar that said drawbar will be held closely adjacent said actuators when the actuators are in the condition for holding said drawbar in said first position.

Claim 19

A drawbar assembly in combination with a tractor, comprising: a drawbar; vehicle hitch-engaging means carried by said drawbar; connecting means securing said drawbar to said tractor for movement between first and second positions wherein said hitch-engaging means is respectively disposed in a raised towing condition and a lowered vehicle hitch-engaging condition, said second position being located downwardly and rearwardly from said first position; said drawbar being mounted for movement in the longitudinal center plane of the tractor and said connecting means includes a pair of extensible and retractable hydraulic actuators fixed to the underside of the tractor in side-by-side fore-and-aft extending relationship at the opposite sides of said longitudinal center plane; the piston rods of said actuators extending forwardly and being pivotally connected at their forward ends to the forward end of said drawbar, at least one crank having one end pivotally connected intermediate the ends of said drawbar and having the other end mounted for vertical, fore-and-aft pivotal movement about a fixed transverse axis above said drawbar; said crank and said actuators being positioned in such relationship to each other and to the drawbar that said drawbar will be held closely adjacent said actuators when the actuators are in the condition for holding said drawbar in said first position.

Claim 20

The invention defined in claim 14 wherein a second crank is disposed parallel to said one crank, and wherein a pair of transverse pins are fixed to the opposite lateral sides of the cylinders of said actuators, said one and second cranks respectively having one of their ends pivotally mounted on said pair of pins; a transverse shaft intermediate the end of and connected to said drawbar, and the other ends of said cranks being pivotally mounted on said shaft.

Claim 21

The invention defined in claim 15 wherein said hitch-engaging means includes an upwardly-opening draw hook fixed to the rear end of said drawbar, stop means positioned for engagement by said draw hook when the draw hook is moved to said first position; said drawbar, when in said first position, including a first arm extending horizontally between said draw hook and said transverse shaft and a second arm angled upwardly from said transverse shaft to the pivOtal connection between the pistons and rods and the drawbar whereby sufficient working clearance is provided beneath the tractor when the drawbar is in the raised transport position.

Claim 22

The invention defined in claim 14 and further including safety means for locking the drawbar in said first position, said safety means including a transverse opening in said drawbar, said opening being elongated in the direction of travel of said tractor, locking bolt means including a locking bolt adapted for insertion into said opening when said drawbar is in said first position, said locking bolt being loosely received in said opening so as to provide lost motion in said direction of travel between the drawbar and the locking bolt and said actuator being disposed so as to cushion draft loads applied to said drawbar.