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:
Apr. 12, 1983
Filed:
Sep. 09, 1980
Applicant:
Inventors:
Assignee:
Gewerkschaft Eisenhutte Westfalia, Lunen, DE;
Primary Examiner:
Int. Cl.
CPC ...
E21D / ;
U.S. Cl.
CPC ...
405299 ; 405291 ;
Abstract
A roof support unit has a pair of spaced floor girders and an advance mechanism comprising a hydraulic advance ram and a pair of relay rods connected, at one end, to a head-piece which is attached to a longwall conveyor. The other ends of the relay rods are attached to a guide element which is slidably guided by a pair of guide rails attached to the mutually-facing sides of the floor girders. The hydraulic advance ram is pivotally attached to the guide element and to the floor girders. Means are provided for aligning the ends of the floor girders remote from the head-piece when the hydraulic advance ram is pressurized.