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:
Feb. 17, 2004
Filed:
Sep. 24, 2002
Thomas Kammerdiener, Graz, AT;
Ludwig Buergler, St. Radegund, AT;
AVL List GmbH, Graz, AT;
Abstract
A variable valve drive for a cam-actuated lift valve of an internal combustion engine which is loaded by a closing pressure against the direction of opening, includes a hydraulic power generating device acting on the lift valve against the closing force with a control piston arranged longitudinally displaceable in a cylinder and adjacent to a hydraulic control chamber, a stroke of the lift valve produced by an actuating cam being at least reducible by removing hydraulic liquid from the control chamber by means of a control valve. In order to arrange the valve stroke and valve opening as free as possible in the simplest possible way the control chamber is connectable with a high pressure level preferably by means of the control valve.