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. 08, 1980
Filed:
Jun. 22, 1978
Applicant:
Inventors:
Assignee:
Taiheiyo Engineering Inc., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
E21C / ;
U.S. Cl.
CPC ...
299 11 ; 299 12 ; 299 19 ;
Abstract
A safety wall treating method employed in the coal mining operation at the long wall face of a coal mine comprises shearing the long wall face leaving safety wall(s) at one or both side(s) of the face but shearing through the safety wall(s) at regular intervals to form intake or exhaust openings communicating with intake or exhaust tunnels.