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:
Sep. 05, 1995
Filed:
Feb. 28, 1994
Hiroto Sasaki, Nara, JP;
Osamu Sano, Nara, JP;
Koyo Seiko Co., Ltd., Osaka, JP;
Abstract
The hydraulic control valve 30 of a hydraulic actuator 20 for generating steering assist force comprises a first valve member 31 and a second valve member 32, both of which are rotatable relative to each other in response to steering resistance. Throttling portions are formed of spaces between axially extending edges defined by slots of the first valve member and axially extending edges defined by slots of the second valve member. The first hydraulic oil outlet slot 51b is located between a right turn slot 50a and a left turn slot 50b. The second hydraulic oil outlet slot 51c is located between communication slots 50c. Hydraulic oil feed slots 51a are located between a right turn slot 50a and a communication slot 50c and between a left turn slot 50b and a communication slot 50c. A closing angle of at least one type of second group throttling portions A', B', C' and D' is set larger than a closing angle of each of a first group throttling portions A, B, C and D. A variable throttle valve 60, capable of varying the flow area of its own throttling portion in response to driving conditions, is disposed between the second group throttling portions A', B', C' and D' and the tank 71.