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. 26, 1993
Filed:
Jun. 18, 1991
Applicant:
Inventors:
Guy Geuns, Wuppertal, DE;
Werner Reinelt, Bochum, DE;
Assignee:
Hermann Hemscheidt Maschinenfabrik GmbH & Co., Wuppertal, DE;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
F01B / ; F01B / ;
U.S. Cl.
CPC ...
9117 / ; 91459 ; 91518 ; 91447 ; 417303 ; 417442 ; 60427 ;
Abstract
A control system for longwall face support frames as used in mines, the system comprising pushing rams which are adapted to be actuated at two different pressures (for example, a low pressure of about 70 to 120 bar for non-defined cutting and a high pressure of 120 to 350 bar for defined cutting) with each pushing ram being individually actuatable by a respective non-return valve arrangement, the pushing rams being connected by a common pressure line to an hydraulic pressure unit.