Patent ID: 8262118

Claim:
A truck tractor and removable body unit system selectively configurable as a fixed body or an articulated truck-trailer combination, comprising: a truck tractor having a frame supporting a drive axle and a steer axle and having a fifth wheel mounted on the frame, a body unit having a body mounted on a frame, the frame supported by an axle and having a king pin for releasably engaging a fifth wheel, a coupling mechanism for releasably coupling the truck tractor frame and the body unit frame while allowing relative vertical pivoting movement between the truck tractor and body unit about the king pin and fifth wheel, and constraining relative lateral movement, the coupling mechanism releasably coupling a rear of the truck tractor frame to a location on the body unit spaced from the king pin, wherein, the coupling mechanism comprises a pair of laterally extending pins mounted to opposite sides of one of the truck tractor frame and body unit frame and a pair of coupling plates mounted to opposite sides of the other of the truck tractor frame and body unit, the coupling plates each including a vertically oriented slot shaped to accept a pin and allow relative vertical movement of the pin in the slot; and an adjustable spring mounted to one of the truck tractor and body unit to act between the truck tractor frame and the body unit frame to adjust a loading between the truck tractor frame and body unit.