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. 23, 1979
Filed:
Jun. 20, 1977
Applicant:
Inventor:
Leslie C Lang, Beaconsfield, CA;
Assignee:
Canadian Industries Limited, Montreal, CA;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F42B / ;
U.S. Cl.
CPC ...
102 23 ; 299 13 ;
Abstract
A novel method of excavating underground chambers in strong rock is provided which is particularly suitable for use in stope and pillar mining operations. The method takes advantage of blasting techniques and specifically the use of large diameter spherical explosive charges by locating a spherical charge in a cavity provided in the ceiling or roof of an underground chamber. Upon detonation of the charge, an optimum volume of cavity is produced in the chamber ceiling from which well fragmented ore rock is displayed by gravity to the floor of the chamber from where it is easily removed.