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:
Aug. 23, 1994
Filed:
Jan. 08, 1993
Eugen Eberhart, Dusseldorf, DE;
TRW Fahrwerksysteme GmbH & Co. KG, Dusseldorf, DE;
Abstract
A power steering device supplies hydraulic oil to the left and right chambers (6,7) of a servo cylinder (3) by means of a pump (10) via a rotary slide valve (9), whereby a reaction piston (18) that is stressed by a pressure spring (19) is arranged between an input shaft (14) and a control sleeve (15) of the rotary slide valve (9). In order to create a simply constructed hydraulic reaction system for this power steering device, it is suggested that a ratio pressure control valve (VDRV) (30) to reduce the system pressure (P) to a lower reaction pressure (P2) and a variable stop (29) to control the hydraulic retroactive moment as a function of the speed are arranged in a line (31) between the pump (10) and the rear side of the reaction piston (18) that is stressed by the pressure spring (19). The invention furthermore suggests that a variable stop (34) to control the return pressure (PR) as a function of the speed is arranged in a line (PR) between the front side of the reaction piston (18) and a tank (27).