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. 18, 2000
Filed:
Apr. 14, 1998
Dieter Goppelt, Aurachtal, DE;
Mike Kohrs, Wilthen, DE;
Jochen Auchter, Aurachtal, DE;
Joachim Matuschka, Emskirchen, DE;
INA Walzlager Schaeffler oHG, , DE;
Abstract
A device for varying the opening and closing times of gas exchange valves of an internal combustion engine, comprising a drive unit (2) which is in driving relationship with a crankshaft through a traction element and a driven unit (14) connected to an intake or exhaust camshaft, there being arranged within the device (1), a coupling element (18) by which a rotationally fixed, force-transmitting connection can be established between the drive unit (2) and the driven unit (14) when the pressure of the hydraulic medium falls below a level required for the displacement of the adjusting piston (9), the coupling element (18) being configured as a locking piston (19) which can be displaced on the one hand by hydraulic pressure and on the other hand by an auxiliary energy and comprises on an end face (26) a number of concentrically arranged extensions (27) which are associated to complementary recesses (35) of a locking ring (34) in the housing (6) to avoid noise generation on starting of the internal combustion engine caused by an inadequate hydraulic clamping-in of the adjusting piston (9).