The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 24, 1987
Filed:
Aug. 28, 1985
Frederick J Adams, Clevedon, GB;
TRW Cam Gears Limited, Hitchin, GB;
Abstract
A vehicle control system has a system part 5 with a pump 6 feeding an open centre valve 4 which controls power assistance for vehicle steering. A second system part 11 has a pump 16 feeding an accumulator 13 and a closed centre valve 10 which controls operation of a clutch or brake booster 2. The pumps 6 and 16 are simultaneously driven by a motor 18. A by-pass valve 21 in conduit 20 is responsive through a pressure transducer 22 and an electrical control unit 19 to pressure in the accumulator 13 so that when the accumulator pressure attains a predetermined value the by-pass valve 21 opens communication between the output from pump 16 and a reservoir 7 to relieve the load on the motor 18. A pressure regulating valve 23 is provided in the steering system part 5. The valve 23 is responsive to pressure from the output of the second pump 16 through conduit 28 and permits the output from the pump 6 to flow by way of conduits 24 and 9 to the reservoir 7 when the pressure from the pump 16 attains a predetermined value so that the pressure available to the valve 4 is less than the maximum pressure available from the output of the pump 6 and the load on the motor 18 which is attributable to it driving the pump 6 is relieved. The valve 23 is preferably a spring loaded spool valve displaceable by expansion of a chamber through the admission of fluid from conduit 28.