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:
Oct. 24, 1989
Filed:
Jun. 29, 1988
Nissan Motor Co., Ltd., Yokohama, JP;
Abstract
A variable assist power steering system employing a fluid distributor circuit of the open center type is disclosed. The fluid distributor circuit includes two parallel fluid flow paths connected to both chambers of a power cylinder respectively to produce a pressure differential between the both cylinder chambers in response to steering torque. For modulating the valve characteristics, two additional variable flow restrictors are arranged in series with two main variable flow restrictors and two bypass paths are arranged to bypass the main variable flow restrictors, respectively. The bypass paths are provided with variable flow orifice valves, respectively, which valves are controlled in response to a turning direction of a steering wheel and also to some external signal, such as vehicle speed.