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:
Jun. 16, 1998
Filed:
May. 19, 1997
Ulrich Letsche, Stuttgart, DE;
Daimler-Benz AG, Stuttgart, DE;
Abstract
In a hydraulic operating mechanism for a valve which comprises a valve stem with first spring means acting on the valve stem in the valve closing direction, and second spring means acting at least intermittently on the valve stem in a valve opening direction, the compressing force of the second spring means is controlled hydraulically during the operation of the valve control device. In order to keep the control forces required for operating the valve as low as possible over its entire operating range, the second spring means comprises a spring combination composed of at least two springs which have different spring forces providing for a maximum spring force of the second spring means at the start of the valve opening stroke.