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:
Jul. 09, 2013
Filed:
Mar. 16, 2011
Steffen Heyn, Niederwerm, DE;
Bernd Zeissner, Volkach, DE;
Steffen Heyn, Niederwerm, DE;
Bernd Zeissner, Volkach, DE;
ZF Friedrichshafen AG, Friedrichshafen, DE;
Abstract
A vibration damper with stroke-dependent damping force includes a cylinder in which a piston rod with a piston is axially movable. The piston divides the cylinder into two work spaces filled with damping medium. A bypass between the work spaces is opened or closed depending on the piston position. The piston has a damping valve for at least one through-flow direction formed by a valve body that partially covers a through-flow channel in the damping valve. The valve body has first and second pressure-actuated surfaces on opposite sides of the valve body. The action of the second pressure-actuated surface depends on the position of the piston in relation to the bypass. The first pressure-actuated surface exerts a lifting force and the second pressure-actuated surface exerts a closing force on the valve disk. The second pressure-actuated surface is connected to a control space and a connection channel that overlaps with the bypass depending on the stroke position of the piston.