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. 28, 2015
Filed:
Jul. 19, 2013
Dirk Litterscheid, Eitorf, DE;
Johannes Hoof, Wiehl, DE;
Reinhard Sonnenburg, Burkardroth, DE;
ZF Friedrichshafen AG, Friedrichshafen, DE;
Abstract
A vibration damper includes a piston rod which is axially movable in a cylinder and at which is arranged a housing in which an auxiliary piston is axially movably supported, wherein the auxiliary piston is connected to a piston rod portion at which a main piston is arranged, wherein the auxiliary piston and the main piston are outfitted with damping valves which generate a damping force for both movement directions of the piston rod and piston rod portion, wherein the main piston divides the cylinder into a working chamber on the piston rod side and a working chamber remote of the piston rod, both of which working chambers are filled with damping medium, and the auxiliary piston divides the housing into two auxiliary chambers, wherein the auxiliary piston generates a damping force over its entire stroke path, which damping force is always greater than the damping force of the main piston at an identical stroke speed.