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:
Apr. 29, 2008
Filed:
Feb. 23, 2005
Hubert Beck, Eitorf, DE;
Hubert Beck, Eitorf, DE;
ZF Friedrichshafen AG, Friedrichshafen, DE;
Abstract
Spring strut unit for suspension systems of motor vehicles with a fastening connection on the body side and another fastening connection on the wheel side; with a helical spring supported between the body and the wheel; and with a vibration damper installed between the body-side fastening connection and the wheel-side fastening connection. The vibration damper includes a working cylinder, a damping piston attached to a piston rod, damping valves installed in the damping piston, and a compensating space. The helical spring can be pretensioned by a ring-shaped cylinder, which can be actuated by a hydraulic medium. A pump rod is mounted in a permanent axial position in the working cylinder of the vibration damper and cooperates with a cavity in the piston rod to form a pump space. Axial movements of the piston rod cause damping medium to be conveyed through flow connections from one of the working spaces of the working cylinder via the pump space and through a flow connection of the pump rod into the ring-shaped cylinder.