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. 30, 1987
Filed:
Feb. 05, 1985
Applicant:
Inventors:
Karl Krieger, Wuppertal, DE;
Werner Reinelt, Bochum, DE;
Assignee:
Hermann Hemscheidt Maschinenfabrik GmbH & Co., Wuppertal, DE;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
E21D / ; E21D / ;
U.S. Cl.
CPC ...
405302 ; 405291 ; 91524 ; 91527 ;
Abstract
Valves regulating the supply of hydraulic fluid to hydraulic cylinders of an hydraulic walking mine-roof support are controlled by apparatus comprising an axially-movable switching shaft provided with cams which is rotatable into successive switching stations where it is immobilized by spring-loaded stop pins to that the cams bear on tappets to actuate the respective valves, there being a switching spring acting on the shaft to return the shaft to its initial position of rest after it has been axially displaced and rotated out of that position of rest.