Automatic antijackknifing control for articulated vehicles

Claim 1

In combination with a tractor and trailer, an antijackknife coupling comprising: a coupling plate secured to said trailer and having a plurality of coupling pins depending therefrom; a baseplate secured to the tractor and having a vertical spindle thereon; a pair of arcuate brake shoes, positioned on the base plate and having a pair of their adjacent ends pivotally secured together by movable linkage means; an hydraulic cylinder having three movable pistons mounted on the base plate, and having an actuating rod with a projecting cam follower; the pistons including one piston secured to the actuating rod, and pistons secured to each of said brake shoes; a cam, having a central indentation therein mounted on the spindle, the cam follower being engaged against said indentation when the tractor and trailer are aligned; a drum mounted on the spindle rotatably and secured to the cam, movement of the cam responsive to misalignment of the tractor and trailer resulting in movement of the cam follower and actuating rod and resulting in movement of the pistons secured to the brake shoes to move the brake shoes into contact with the drum; and a bearing plate secured to the drum and having guide slots therein receiving said coupling pins of said coupling plate.