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:
Nov. 16, 2004
Filed:
Dec. 11, 2002
Takashi Nezu, Kanagawa, JP;
Yohei Katayama, Kanagawa, JP;
Tokico Ltd., Kanagawa-ken, JP;
Abstract
A piston connected to a piston rod is slidably fitted in a cylinder having a hydraulic fluid sealed therein. First and second poppet valves having different valve opening characteristics are provided in first and second extension main passages, respectively. A pilot control valve is provided in a sub-passage. The control pressure of the pilot control valve is adjusted by a proportional solenoid, thereby controlling damping force. At the same time, the pressure at the upstream side of the pilot control valve is introduced into back-pressure chambers to adjust the valve opening pressures of the first and second poppet valves. Because the first and second poppet valves are sequentially opened or closed, damping force can be controlled stepwisely, and ideal damping force characteristics can be obtained.