Abstract: An apparatus for cushioning a body of a dump vehicle when the body is lowered, including structure defining a fluid passageway between first and second end portions of the structure. The structure is adapted to be disposed in a fluid pressure operated actuator used to raise and lower a body of a dump vehicle. When the structure is disposed in such actuator the passageway extends in a longitudinal direction of such actuator and the second end portion communicates with an interior of such actuator. A cushioning spool is adapted to be connected to such actuator for moving in the longitudinal direction into the passageway. A poppet includes an orifice that receives the spool for enabling the poppet to be slidably movable on the spool in the longitudinal direction.

Abstract: A hydraulic circuit for pitch and tilt control of a dozer blade attached to push arms on a vehicle with a pitch ram connected between one push arm and the blade and a dual actuator consisting of a second pitch ram and a tilt ram connected at their head ends. A pitch valve directs hydraulic fluid to and from the pitch rams with a diverter/combiner valve interposed therebetween to assure a flow of fluid either to said rams or from said rams at equal rates. Pilot-operated check valves hydraulically lock the pitch rams until opened by pressure directed from said pitch valve. Tilt and lift valves directs fluid pressure to and from the tilt ram and a lift ram respectively with regeneration capability for both tilt and lift functions.

Abstract: A control means for a variable displacement pump (12) driven by an engine (10) and having a servo-cylinder (78) determining the displacement of the variable pump (12). A charge pump (14) is driven by the engine (10) and supplies charge pressure to the variable pump (12) through an orifice (40). Pilot conduits (42,44) on each side of the orifice (40) sense the pressure drop due to flow and relay the resulting signals to each end of a metering spool (52) in a speed control valve (46), which is arranged to control the pressure in the servo-cylinder (78). A spring (90) biases the servo-cylinder (78) toward an extreme position for the variable pump (12) and opposes the pressure directed to the servo-cylinder (78) by the speed valve (46) in order to provide a smooth transition between the extreme positions for pump displacement.

Abstract: A circuit for controlling pitch and tilt of a dozer blade in which two cylinders are connected between the dozer blade and the dozer push arms. One cylinder only is extended and retracted to achieve tilt, and both cylinders are operated in unison to achieve pitch with divider valves assuring that equal volumes of hydraulic fluid reach each cylinder and are expelled from each cylinder. Extension and retraction is selectively determined by a directional control valve, while a selector valve determines whether both cylinders or only one cylinder is connected with the directional control valve.