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:
Dec. 09, 1986
Filed:
Apr. 26, 1985
Frederick J Adams, Clevedon, GB;
Kenneth J Heap, Cheddar, GB;
TRW Cam Gears Limited, Clevedon, GB;
Abstract
A power assistance steering system 10 for a vehicle comprises steering gear 12 having an internal hydraulic ram supplied with hydraulic fluid by a pump 14 from a reservoir 16 via a solenoid valve 18 controlled by a micro-processor 20 which also controls an electric motor 22 for driving pump 14. Steering input torque is sensed by a torque sensor 36 and steering direction is sensed by a direction switch 34. Output signals from these devices are fed to micro-processor 20 which controls solenoid valve 18 and pump motor 22 accordingly, varying the motor speed in accordance with the pressure requirements of the steering ram as sensed by the torque sensor. In a further embodiment the pump is driven at a constant speed and a proportional control valve 74 is controlled by a micro-processor 78 to vary the fluid pressure supply.