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:
Jan. 09, 1990
Filed:
Jan. 19, 1989
Applicant:
Inventor:
Andreas Rachel, Wuppertal, DE;
Assignee:
Herman Hemscheidt Maschinenfabrik GmbH & Co., Wuppertal, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
E21D / ;
U.S. Cl.
CPC ...
405302 ; 405291 ; 299 11 ;
Abstract
An electro-hydraulic control system for self-advancing mine-roof supports in a high-output longwall mine is used to form a sequence zone behind the mining machine whereby individual supports simultaneously operate in the sequence of prop drawing, advancing and setting so that, during the sequence, the roof in the sequence zone is supported by at least each second support with the length of the sequence phase so depending on the cutting speed of the mining machine that it increases with increasing speed to ensure that the roof exposed by the mining machine is supported without delay.