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. 27, 1985
Filed:
Apr. 24, 1984
Walter Weirich, Dortmund, DE;
Michael Dettmers, Kamen, DE;
Gewerkschaft Eisenhutte Westfalia, Lunen, DE;
Abstract
A compact hydraulic control device for use with mining apparatus is composed of a housing block containing tappet-operated valves. A multi-part cam shaft serves selectively to operate the valves by displacing the tappets by manual control effected by external levers. To automatically restore the cam shaft back into a neutral position as a 'dead-man's handle' restoring system use is made of a pair of piston and cylinder assemblies mounted as detachable cartridges in parallel locations within bores in the housing block and having push rods which act on a cam of the cam shaft under the action of hydraulic or pneumatic pressure medium.