Angled roll axis suspension for off-road vehicles

Abstract

An off-road vehicle of the large relatively slow earthmoving type having a rear frame with a set of wheels and having, at its forward end, a front frame, for example in the form of an axle assembly, mounting a set of steerable wheels and with means for driving at least one set of wheels. A suspension coupling in the form of a fore-and-aft extending hinge joint is interposed between the two frames to accomodate relative rolling movement. Such hinge joint is positioned adjacent the front wheels and is angled downwardly so that the hinge axis, when extended, intersects the ground at a position which is substantially centered with respect to the rear wheels, with the result that the steering direction remains substantially constant in spite of engagement of humps and hollows by individual ones of the wheels. Alternate embodiments of the invention utilize different drives, steering gear, and cab location. specifically the invention is usable with wagon type steering, Ackermann steering, skid steering or articulated steering, and the drive may be either two-wheel or four-wheel, with tandem wheels or tracks being optional. The cab may be mounted for rolling movement with the rear axle or front axle and either ' steered' or 'unsteered.' The invention is described in connection with both sprung and unsprung axle versions.