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. 04, 1997
Filed:
Aug. 17, 1995
Alfred Trzmiel, Grafenberg, DE;
Wolfgang Stephan, Zizishausen, DE;
Thomas Alber, Leinfelden-Echterdingen, DE;
Andreas Jaksch, Esslingen, DE;
Olaf Fiedler, Remchingen, DE;
Dr.Ing. h.c.F. Porsche AG, Weissach, DE;
Abstract
A variable valve timing camshaft drive system is provided with an adjusting device arranged between the loose end and the load end of a chain which is operative between chain wheels of two parallel camshafts of an internal-combustion engine. For tightening the chain and influencing the relative rotating position of a camshaft--variable valve timing--the device comprises a first hydraulic piston and a second hydraulic piston. The first hydraulic piston can be alternately acted upon by pressure and, in the process, takes up two end positions. By means of a third hydraulic piston, the first hydraulic piston may also be fixed in an intermediate position.