Husco International, Inc.

Applied Power Inc.

Eric Norman Griesbach

Jeffrey A Rogala

David Schedgick

Xudong Yu

Andreas S Pack

Bradley James Kramer

James E Olsen

Douglas C Blotz

The hitch on a vehicle is moved by a hydraulic actuator. A method for controlling the hydraulic actuator defines a draft force setpoint in response to separately averaging two forces acting on lateral sides of the hitch, while operating in a configuration mode. During regular operation, a draft load is calculated from sensing those two forces and deriving a draft force error from difference between the draft load and the draft force setpoint. The draft force error is used to control fluid flow to and from the hydraulic actuator. One aspect of the control method derates the draft force error as the hitch moves beyond a predefined threshold position.

Draft control method for operating an earth moving machine

A suspension system isolates the operator cab or seat from vibrations in the chassis of a vehicle. At least one hydraulic actuator is connected between the cab or seat and the vehicle chassis. An accumulator is coupled to the hydraulic actuator and acts as a hydraulic spring to attenuate high frequency vibrations. An electrically operable, three-position, closed-center control valve selectively connects the hydraulic actuator to a source of pressurized hydraulic fluid or a reservoir. Sensors detect acceleration and displacement of the cab or seat to which a controller responds by operating the valve. That control of the valve actively drives the hydraulic actuator to produce motion that counters the relatively low frequency vibrations from the chassis.

Active vehicle suspension with a hydraulic spring

A vehicle suspension has one or more hydraulic cylinders connecting an axle to a frame of the vehicle and each cylinder has a first and second chambers. The suspension operates in either a regeneration mode, in which a fluid path is provided between the first and second chambers, and a double acting mode, in which the first and second chambers are isolated from each other and fluid flows between each chamber and a separate accumulator. The selection between the regeneration and double acting modes is made in response to the pressure level in the cylinder as determined by a pressure sensor of a closed loop control system or by the pressure versus current characteristics of a electrically operated valve in the suspension for a loop control system. The hydraulic system also is able to raise and lower the suspension as necessary due to changes in the load carried by the vehicle.

Dual mode regenerative suspension for an off-road vehicle

A valve assembly has a single piece body that houses a plurality of hydraulic valves. Each valve includes a spool which controls the flow of fluid between a pair of work ports in one side of the body and a pump inlet and a tank outlet. The valves are operated by selectively applying pressurized fluid to one end or the other of the spool. That pressure is provided by a conduit or a pilot valve that is attached to a control port in the one side of the body. Because the majority of the connections to the valve assembly are made to the one side of the body access is only required to that side.

Multiple hydraulic valve assembly with a monolithic block

A hydraulic system for opening and/or closing the rear lift gate of a vehicle uses a double or single acting gas charged hydraulic cylinder. If double acting, a second piston separates the head side of the cylinder into hydraulic and gas chambers. A unidirectional (for the single acting cylinder) or a bidirectional (for the double acting cylinder) drives a pump to operate the cylinder. A solenoid actuated on-off valve selectively communicates the ports of the cylinder with tank pressure. A gas charge accumulator may also be provided. In the double acting embodiment, a two way ball shuttle valve which is vented in the center provides alternating communication between the two cylinder ports.

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North Prairie, WI, United States of America

Eric Norman Griesbach