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. 08, 2006
Filed:
Apr. 13, 2005
Tadaharu Yokota, Kanagawa, JP;
Masakazu Kurata, Yokohama, JP;
Michiya Hiramoto, Yokohama, JP;
Yukio Sudo, Kanagawa, JP;
Tadaharu Yokota, Kanagawa, JP;
Masakazu Kurata, Yokohama, JP;
Michiya Hiramoto, Yokohama, JP;
Yukio Sudo, Kanagawa, JP;
Hitachi, Ltd., Tokyo-to, JP;
Abstract
A power steering system for a vehicle. The system includes a hydraulic power cylinder, first and second hydraulic lines, a bypass passage through which the first and second hydraulic lines are connected with each other, and a flow passage change-over device adapted to close the bypass passage during steering assisting. A supply passage and a return passage are disposed in parallel with each other to form part of each of the first and second hydraulic lines. The flow passage change-over device is disposed in each of the first and second hydraulic lines. A differential pressure regulating valve is disposed in each of the return passages and adapted to allow hydraulic fluid to flow toward the hydraulic pressure source in a condition where pressure on side of the hydraulic power cylinder becomes higher than a set pressure or higher than pressure on side of the hydraulic pressure source.