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:
Aug. 10, 2004
Filed:
Jul. 10, 2003
Robert Schmidt, Fellbach, DE;
Holger Steffen, Stuttgart, DE;
Thomas Stolk, Kirchheim, DE;
Alexander von Gaisberg-Helfenberg, Fellbach, DE;
DaimlerChrysler AG, Stuttgart, DE;
Abstract
In an operating system for a hydraulic valve clearance control element of an internal combustion engine, which includes a hydraulic fluid having a pressure that depends on the engine operating state and wherein the hydraulic clearance control element includes a pressure chamber in which a hydraulic fluid volume is maintained for adjusting the length of the hydraulic clearance control element and means for maintaining the fluid volume when, after engine shut down, the pressure of the hydraulic fluid supplied by an engine fluid pressure source drops below a certain value so as to maintain the hydraulic clearance control element at its operating length during engine shutdown, means are arranged on the hydraulic fluid supply line to the hydraulic valve clearance control element for releasing hydraulic fluid to reduce its pressure below the certain value immediately upon engine shut down to safely maintain the hydraulic clearance control elements at their operating length.