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:
Mar. 05, 1991
Filed:
Mar. 14, 1990
Rudolf Polster, Baiersdorf, DE;
Werner Schmidt, Herzogenaurach, DE;
INA Walzlager Schaeffler KG, , DE;
Abstract
A hydraulic actuating element particularly for a belt tightener having a pressure chamber arranged behind a piston guided in a cylinder, a reservoir separated from the pressure chamber by a check valve, the cylinder and the reservoir being completely oil filled, the outside of the reservoir being defined by a bellows, a leakage gap between the piston and the cylinder being open towards the reservoir and at its one side towards the pressure chamber, whereby a compression spring acts to urge apart the piston and cylinder, characterized in that the reservoir (13) surrounds the cylinder (2) and being limited by the bellows (12) at its outside, the bellows (12) being sealingly secured at one end to a base element (10) secured to the cylinder (2) and at its other end to a base element (11) secured to the piston (1), and that the leakage gap (3) at its other side (17) is externally shielded by the bellows (12) and open to the reservoir (13).