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. 27, 1990
Filed:
Jul. 11, 1988
Jacques M Sirven, 78000 Versailles, FR;
Other;
Abstract
A damper includes a cylinder containing a hydraulic fluid inside which is a piston defining first and second chambers in the cylinder, the second chamber containing the piston rod. A hydraulic fluid reservoir communicates selectively with the first chamber. A reference chamber contains a gas at substantially constant pressure. A control valve is acted on by the pressure of fluid in the first chamber (tending to open the valve), by a return spring, by the pressure in the reference chamber and by the pressure of fluid in the second chamber (tending to close the valve). A flow restrictor between the reservoir and the first chamber enables hydraulic fluid to flow only from the first chamber to the reservoir. It defines a control pressure to open the valve in response to the rate of inward movement of the piston rod exceeding a predetermined limit value. The flow rate permitted by the flow restrictor is variable so that the valve can open at rates of inward movement different to the predetermined limit value. This varies the damper characteristics in compression. The damper characteristics can also be varied in expansion.