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. 27, 1990
Filed:
Apr. 26, 1989
Helmut Motzer, Leinfelden-Echterdingen, DE;
Herion-Werke KG, Fellbach, DE;
Abstract
A hydraulic safety valve which is controlled by two electromagnetically actuatable pilot valves is provided with two valve bodies movable in opposite direction towards each other and including control pistons for regulating the connection between one pump port, two working ports and two tank ports. Upon occurrence of a faulty switching, the valve bodies move into a hydraulically locked end position. One of both pilot valves is designed as a proportional pressure differential valve and the control pistons associated therewith are provided with fine control notches so that the valve can be proportionally controlled to thereby allow a control of the pressure buildup, the speed and direction of motion of a consumer which is connected to the valve.