Mechanism for adjusting the position of a semitrailer coupler on a semitrailer tractor

Claim 2

In a coupling arrangement for coupling a semitrailer to a tractor including a guide member on said tractor, a coupling member mounted on said guide member for movement in the normal direction of tractor travel, and locking means for locking said members to each other in each of a plurality of positions spaced in said direction, the improvement which comprises: a. selector means on one of said members for selecting one of said positions while said coupling member is in another position; b. lock actuator means on the other member engageable with said selector means during said movement of said coupling member and responsive to engagement with said selector means in the selected position of the coupling member for actuating said locking means and for thereby locking said members to each other; c. manually operated withdrawing means for withdrawing said locking means and for thereby unlocking said members for relative movement; and d. blocking means preventing manual actuating of said locking means.

Claim 3

In an arrangement as set forth in claim 1, said selector means being mounted on said guide member.

Claim 4

In an arrangement as set forth in claim 2, said selector means including a bar member, a selector member movable on said bar member in said direction and engageable with said lock actuator means, and releasable means for securing said selector member on said bar member against movement in said direction in each of a plurality of selected positions respectively corresponding to said positions of said coupling member.

Claim 5

In an arrangement as set forth in claim 3, said selector member having a cam face, and said lock actuator means including a pivotally mounted member angularly displaced by engagement with said cam face.

Claim 6

In an arrangement as set forth in claim 3, said lock actuator means being electrically operated, and including a switch engageable with said selector member for operating said lock actuator means.

Claim 7

In an arrangement as set forth in claim 3, cooperating indicia on said selector member and on said bar member for indicating the permissible load of said trailer in each of said positions of the coupling member.

Claim 8

In an arrangement as set forth in claim 1, said blocking means including latch means for holding said withdrawing means in a position in which said locking means are withdrawn and said members are unlocked, said selector means cooperating with said latch means for releasing said withdrawing means from said position of the same in the selected position of the coupling member.

Claim 9

In an arrangement as set forth in claim 7, said blocking means further including means making said latch means inaccessible to an operator''s hand.

Claim 10

In an arrangement as set forth in claim 7, said locking means including a locking member, said guide member being formed with a row of openings spaced in said direction, said locking member being mounted on said coupling member for movement along said row when said coupling member moves in said direction; said lock actuator means including biasing means biasing said locking member toward engagement with said openings in said row, said withdrawing means withdrawing said locking member from the engaged opening when operated.

Claim 11

In an arrangement as set forth in claim 8, said means making the latch means inaccessible including a casing formed with opposite apertures; said withdrawing means including an elongated rod member received in said apertures for longitudinal movement through said casing, a handle on a portion of said rod member outside said casing, and connecting means connecting said rod member to said locking means for withdrawing said locking means in response to longitudinal movement of said rod member in one direction into a predetermined position, and for releasing said locking means in response to movement of said rod member from said predetermined position into a locking position in a direction opposite to said one direction; an abutment on said rod member, said abutment being in said casing when said rod member is in said predetermined position thereof; said latch means including a latch member movably mounted in said casing and biased toward engagement with said abutment for thereby holding said rod member in said predetermined position thereof; cooperating cam means on said selector means and on said latch member for disengaging said latch member from said abutment and for thereby releasing said rod member for movement in said opposite direction away from said predetermined position when said guide member and said coupling member are in the selected position.

Claim 12

In an arrangement as set forth in claim 9, a blocking member longitudinally spaced on said rod member from said abutment, another latch member movably mounted on the outside of said casing and biased toward a position in which said other latch member engages said blocking member and thereby holds said rod member in said locking position against a pulling force applied to said handle.