Abstract: In articulated machines it has long been a desire to provide a steering system that will permit the incorporation of machine controls into a steering wheel assembly and yet provide the operator with mechanical feedback through the steering wheel. The present invention accomplishes this goal by providing a steering wheel assembly on a first frame of the machine and a control valve on the second frame that articulates with respect to the first. The steering wheel assembly and control valve are connected by a shaft assembly that includes a pair of constant velocity U-joints interposed along the length thereof. The shaft assembly translates substantially equal amounts of rotation between the steering wheel assembly and the control valve. The control valve is operable in a first and second condition, depending upon the amount of rotation of the steering wheel assembly, to provide different modes of steering that compliment the operation of the machine.

Abstract: An electrohydraulic control device for a drive train of a vehicle is provided. The drive train includes an engine, a transmission, a source of pressurized fluid, and an input clutch connected between the engine and the transmission. The control device senses the rotational output speed of the engine and responsively engages and disengages the input clutch as a function of the engine speed.