Abstract: A power-assist hydraulic system for use in connection with a linkage extending through a housing and mechanically coupled to an actuated member. The power-assisted hydraulic system includes a double-acting hydraulic cylinder having a rod configured for interconnection to the actuated member, an accumulator for storing pressurized hydraulic fluid and a rotary valve. The rotary valve has a valve interface for selectively connecting the hydraulic cylinder to the accumulator. The rotary valve has at least one valve piston for receiving pressurized hydraulic fluid to maintain a hydraulic balance at the valve interface. A sleeve having a bore through which the linkage can extend is mechanically coupled and movably mounted with respect to the rotary valve for moving the rotary valve between a neutral position and first and second rotated positions in response to forces between the linkage and housing.

Abstract: A hydraulic control system configured for use with a towed vehicle hydraulic brake system controls the pressure of the hydraulic fluid provided to the brake as a function of an operator-selected input. A hydraulic pressure control manifold is coupled between a pump and the towed vehicle brake and controls the pressure of the hydraulic fluid supplied to the brake with a plurality of pressure relief check valves interconnected in a parallel hydraulic circuit between the pump and the brake. A plurality of on-off valves are connected in a series hydraulic circuit with the check valves. The pressure relief levels of the check valves correspond to a plurality of towed vehicle braking forces. An operator of a towing vehicle chooses a desired one of the plurality of braking forces through a selector switch.

Abstract: A power-assisted hydraulic steering system for use in connection with a vehicle having a steering linkage which couples a steering wheel to a vehicle steering actuator, an electrically actuated hydraulic pump, and a tank of hydraulic fluid. The steering system includes a boost cylinder connected to the steering actuator, a hydraulic spool valve fluidly coupling the pump and tank to the boost cylinder, and a switch coupled to the pump. A spool which is mechanically coupled to the steering actuator is mounted within the valve for reciprocal motion between neutral, extended and retracted positions, and is biased to the neutral position by a centering spring which establishes a power-assist threshold. The switch senses the position of the spool, and switches the pump on when the spool is in the extended and retracted positions.

Abstract: A brake system for use in connection with a vehicle including a hydraulic internally boosted master cylinder, a hydraulic pump, and hydraulic brakes wherein the master cylinder controls hydraulic fluid pressure to the brakes and has a primary or sensing piston, a modulator stem, and a secondary pistons, with the sensing piston responsive to a mechanical input force to urge the secondary piston forwards increasing the hydraulic fluid pressure applied to the brakes. In a second embodiment, the internally boosted master cylinder further includes a tertiary piston movable by hydraulic pressure between retracted and extended positions and biased toward the retracted position by a tertiary piston return spring. The tertiary piston controls hydraulic pressure applied to one or more brakes independent of the brakes controlled by the secondary piston.

Abstract: A pressure-responsive hydraulic control system (10) has a load-sensing flow-compensated pump (S) connected to a plurality of work sections; with a direction control valve (26, 26') and a pressure compensator valve in each work section; and with a flow-regulated logic check system (45); a flow-metered logic check system (40); an isolation circuit (60, 160, 260); and an induced load check system (70). Each pressure compensator valve is supplied flow-metered fluid from the respective direction control valve and supplies flow-regulated fluid to a hydraulic motor. The flow-regulated logic check system (45) provides a flow-regulated maximum output signal, and the flow-metered logic check system (40) provides a flow-metered maximum output signal.

Abstract: A brake system with a hydraulic pilot brake valve for use in connection with a vehicle requiring finite brake control with high volume pressure control. The brake system includes the hydraulic pilot brake valve, a main hydraulic system, a control hydraulic system, and hydraulic brakes. The main hydraulic system includes a belt-driven hydraulic pump, a tank of hydraulic fluid, and an accumulator. The control hydraulic system includes an electrically actuated hydraulic pump and a tank of hydraulic fluid. The pilot brake valve is designed to control the flow of hydraulic fluid from the main hydraulic system to the hydraulic brakes, and includes a modulator chamber and a primary chamber. The modulator chamber houses a modulator piston valve, and the primary chamber houses a primary input piston which extends into a sleeve chamber of a sleeve. The modulator piston valve controls a modulating fluid flow from the control hydraulic system to generate amplified input forces on the input piston in the primary chamber.

Abstract: A connector (10, 110) for joining a plurality of elements (15, 20; 115, 120) having attachment apertures (19, 21; 119, 121) therein including, a pin (25; 125, 125') having a radially extending head (27; 127) and a shank (26; 126, 126') extending axially from the head and having a tapering outer surface (29; 129, 129') over at least a portion of the axial extent thereof, a sleeve (35, 135) insertable in the attachment apertures and having a tapering inner surface (38; 138, 138') over at least a portion of the axial extent thereof for engaging the tapering outer surface of the pin, a discontinuity (37, 137) in the sleeve extending at least a portion of the axial extent thereof, and fastener (45, 50; 145, 150) for axially displacing the sleeve relative to the pin selectively to expand and to permit reduction in the diameter of at least a portion of the outer surface of the sleeve.