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:
Dec. 11, 1990
Filed:
Aug. 08, 1989
Applicant:
Inventors:
Foster Lewins, Mickleover, GB;
Timothy S Gammons, Ripley, GB;
Assignee:
Coal Industry (Patents) Limited, London, GB;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
E21C / ; E21C / ;
U.S. Cl.
CPC ...
299-1 ; 33367 ; 340689 ;
Abstract
The trailing drum of a double-ended ranging drum shearer is steered in a seam by producing an algorithm which determines, as a result of information derived from signals from the machine dependant on its tilt, direction and amount of movement along a face being cut. The height of the leading drum is used as a reference from which to determine the optimum position of the trailing drum in order that a constant quality of desired mined material is obtained.