Automotive hydraulic system and method for driving a hydraulic accessory in parallel with a power steering unit
OwnerA. Keith Campbellinventor
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Abstract
An automotive hydraulic system having a power steering unit of a vehicle connected in parallel with an externally mounted, hydraulic-cylinder-powered accessory, such as a liftgate, snow plow or dump bed. The vehicle's power steering pump supplies the required hydraulic fluid to the power steering unit and to a cylinder in the accessory, simultaneously in the preferred embodiment and alternately in another. A preferred valve assembly is disclosed which includes a priority flow control valve and a three-position, four-way accessory control valve mounted together in a manifold designed for connection to the vehicle's power steering pump, power steering unit, and hydraulic fluid reservoir, and to a double-acting hydraulic cylinder in the accessory.
Claims12
An automotive hydraulic system for driving a power steering unit of a vehicle in parallel with a hydraulic-cylinder-powered accessory having a hydraulic cylinder, comprising:
- a power steering unit having a control valve responsive to operation of a steering wheel;
- a hydraulic pump having an internal flow control;
- a hydraulic fluid reservoir having an outlet connected to said hydraulic pump;
- a supply line interconnecting said hydraulic pump and said power steering unit;
- a return line interconnecting said power steering unit and said fluid reservoir;
- and
- a hydraulic accessory drive circuit connected in parallel with said power steering unit, said hydraulic accessory drive circuit having an accessory control valve having an inlet connected to said hydraulic pump, an outlet connected to said fluid reservoir, first accessory port means for connecting to a hydraulic cylinder, and valve means for selectively connecting either of said inlet and said outlet to said first accessory port means,
- whereby hydraulic fluid is allowed to flow from said hydraulic pump selectively into said hydraulic cylinder to thereby control the accessory with power from the power steering system of the vehicle.
Dependencies are inferred from the claim text.