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:
Jul. 26, 1983
Filed:
Mar. 24, 1981
Walter Weirich, Dortmund, DE;
Werner Grommas, Dortmund, DE;
Gewerkschaft Eisenhutte Westfalla, Lunen, DE;
Abstract
A hydraulic control system for a mine roof support unit has a control valve assembly for controlling the hydraulic appliances of the unit, and an actuator for actuating the control valve assembly. The actuator has a valve block provided with a plurality of pairs of spool valves. The spool valves of each pair are detachably fixed in a pair of generally parallel bores formed in the valve block. Each pair of spool valves is provided with a respective rocker arm for actuating purposes. Each of the rocker arms is mounted on a respective cover plate, which covers the mouths of the corresponding pair of bores, and which is detachably secured to the valve block.