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:
Mar. 14, 2000
Filed:
Feb. 13, 1997
Norihiro Saita, Isehara, JP;
Tatsuyoshi Maruyama, Atsugi, JP;
Toshinori Aihara, Hadano, JP;
Tadaharu Yokota, Samukawa, JP;
Unisia Jecs Corporation, Atsugi, JP;
Abstract
A steering power assist apparatus is comprised of a power cylinder whose operation is controlled by the a flow rate control valve, a first control valve and a second control valve. The flow rate control valve is connected to a discharge side of a hydraulic pump and controls the amount of the hydraulic oil to be supplied to the first and second control valves according to a load pressure. The first control valve constituted by choke valves is disposed downstream of the flow rate control valve and controls the amount of the hydraulic oil supplied to the second control valve according to a steering torque. The second control valve constituted by choke valves is disposed downstream of the flow rate control valve and controls the amount of the hydraulic oil to the power cylinder according to a steering torque. The choke valves of the second control valve are fully closed after the choke valves of the first control valve are fully closed.