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:
May. 13, 2008
Filed:
Sep. 30, 2005
Hubert Beck, Eitorf, DE;
Hubert Beck, Eitorf, DE;
ZF Friedrichshafen AG, Friedrichshafen, DE;
Abstract
A self-pumping hydropneumatic spring strut unit includes a working cylinder filled with oil under pressure and a piston and rod unit displaceable in the cylinder so as to define two working spaces in the cylinder, and high-pressure and low pressure chambers surrounding the cylinder. The strut unit further has a piston pump operable to transport a working medium from the low-pressure chamber into the one working space which is in flow communication with the high-pressure chamber. The piston pump has a cylinder defined by the inner surface of the piston rod unit, and a hollow pump rod coupled to the working cylinder and having a flow channel in communication with the low-pressure chamber. The flow channel has a deregulating opening on the working space and a throttle in flow communication with the deregulating opening. A filter device protects the throttle from impurities carried by the oil during flow from the deregulating opening to the low pressure chamber.