Drive control apparatus for vehicles

Claim 1

Control apparatus for a hydraulic drive mechanism for a vehicle including a frame and a pair of rotary members at opposite sides of the frame, said drive mechanism including a pair of hydraulic drive motors each connected to a different one of said rotary members, a pair of variable displacement pumps each hydraulically coupled to a different one of said motors and each having a pivotally mounted displacement control arm thereon movable in directions to control operation of its respective pump to impart infinitely variable speed to its respective motor selectively in forward and reverse directions or rotation, and means for driving said pumps, said control apparatus comprising: a. An elongated control rod having a handle at one of its opposite ends; b. mounting means mounting said control rod for swinging movements on an axis extending transversely of said control rod and for pivotal movements on an axis extending longitudinally of said control rod; c. a control bar fixed on said rod in longitudinally spaced relation to said mounting means and extending in diametrically opposite directions transversely of said control rod and generally transversely of said vehicle; d. a pair of rigid links connected to said control bar at generally diametrically opposite sides of said longitudinally extending axis and each to a different one of said control arms for imparting pivotal movements to said control arms selectively to control the rate of forward and rearward speed of the vehicle responsive to swinging movements of the control rod on said transverse axis and to control the steering of the vehicle responsive to pivotal movements of the control rod on said longitudinal axis; e. front and rear pairs of stop elements each engaging said control bar adjacent a different end thereof to limit said movements of the control rod in directions away from said neutral position thereof; f. and yielding means urging said control rod toward a neutral position intermediate the limits of both swinging and pivotal movements thereof, said links disposing both said control arms in neutral positions between forward and reverse directions of pumping movement of their respective pumps when said control rod is moved to said neutral position thereof.