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. 13, 1985
Filed:
Sep. 21, 1983
Walter Weirich, Dortmund, DE;
Michael Dettmers, Kamen, DE;
Gewerkschaft Eisenhutte Westfalia, Lunen, DE;
Abstract
A mine roof support has a main roof-engaging structure 2 carried by hydraulic props 6 in known manner and an auxiliary roof-engaging structure at the front end of the main roof engaging structure. The auxiliary roof-engaging structure can be swung up and down and is itself of multi-part construction with one component 7 directly linked to the main structure and another selectively extendible forward component 8 mounted to the one component. One hydraulic piston and cylinder unit 9 is provided for swinging the auxiliary structure and for setting the structure against the roof and another such unit 10 is provided for selectively extending and retracting the forward component thereof. A hydraulic control arrangement 16-18 associated with the units ensures that when the forward component is being advanced the roof setting pressure acting on the auxiliary structure is automatically reduced.