Unitary coupling for articulated vehicles

Claim 1

A compact, unitary coupling for an articulated vehicle having front and rear sections, the coupling permitting articulation of the vehicle sections about a central vertical axis comprising an annular coupling member having a cylindrical portion trunnion mounted in a longitudinal bore formed on one of the vehicle sections by means of a pair of longitudinally spaced apart bearings, to permit oscillation between the two vehicle sections, the bearings being of relatively large diameter and being arranged relatively close together to achieve a compact configuration for the coupling, one of the bearings arranged adjacent the articulated axis being of greater diameter than the other bearing to facilitate assembly of the unitary coupling with the one vehicle section, an outer surface of the cylindrical coupling member portion and the longitudinal bore in the one vehicle section being stepped to receive the bearings of different diameters for supporting the coupling member portion in the bore, the coupling member integrally including a first pair of diametrically opposed brackets which are pivotally coupled to respective portions of the other vehicle section, the coupling member also integrally including a second pair of diametrically opposed brackets offset relative to the first pair of brackets for pivotal connection with the other vehicle section by means of steering motor means, the coupling member also integrally including first stop surfaces arranged for interaction with stop means of the one vehicle section to limit relative oscillatory movement of the vehicle sections and second stop surfaces arranged for interaction with stop means on the other vehicle section, and a central drive shaft being mounted within the coupling member by bearing means and connected with separate drive shafts in the two vehicle sections by universal joints.