Abstract: A new linked articulation (LA) system for the connection of a leading trailer to a following full trailer in the heavy truck field. LA systems including the present invention constrain the front of the following full trailer to a position on an imaginary extension of the leading trailer's centerline. In the prior art devices, a telescoping `stiffening member` keeps the front portion of the second full trailer on the required line. The present invention uses a rigid and non telescoping tow bar to keep the front of the second trailer on the required line. The tow bar connects the frame of the first trailer to the frame of the second trailer and therefor also does the actual towing.In both the present invention and the prior art LA systems the front of the second trailer is supported by a steerable axle assembly called a `dolly`.

Abstract: A tow vehicle (3) and trailer vehicle (5) are connected by a four-bar hitch which has one arm (1) aligned longitudinally with the central longitudinal axes (12,13) of the vehicles, and a steering arm (6) which is laterally spaced from the main arm. Pivots, (7,8) at the front and rear ends of the steering arm are forwardly offset with respect to the corresponding pivots (2,4') of the main arm. The length of the main arm is no greater then about 1.5 times the length of the steering arm. The rear pivot (8) of the steering arm is offset laterally and forwardly from the rear pivot (4') of the main arm, so that the lateral offset is greater than the forward offset. An embodiment is disclosed wherein the forward pivot on the steering arm is laterally shiftable toward the forward pivot on the main arm to reduce the offtracking of the trailer for certain maneuvering and driving situations.

Abstract: A four-bar link trailer hitch comprising main and steering members, spaced apart and pivotally connected at their rearward ends to the trailer, and pivotally connected at their forward ends to the rearward end of a truck or the like. The main arm lies substantially upon the center line, as viewed in plan, and the steering arm is placed to one side, closer to the centerline at the forward end than the rear. Most of the towing load and any tongue weight is taken by the main arm. The steering arm serves to locate the trailer laterally.