A DOWN-THE-HOLE DRILL TOOL FOR DRILLING IN ADVANCE OF A CASING TUBE

摘要

the invention relates to a drilling tool ", which is designed to dig a hole in the casing by a drag (15).the drilling tool includes a drill core (12) and a pilot alu00e9soire (14), and a guide (17, 17 ', 17', 17 ', 17', 37) for guiding a drilling tool and the well casing (15) with the other, and a shaft (11, 11 ', 11', 11 '') intended to be connected to a hammer perfora from (23)). the invention relates to a guide unit and a battery module itself.in the drilling tools known to the model mentioned above, the threaded connection, for example, between the guide and the support of the alu00e9soire, is the weak point.to overcome this problem, the present invention provides a structural design of a drilling tool of the type in question, which avoids the threaded connections in the parts of the drilling tool, which is subjected to bending forces.the present invention is characterized in that the shaft (11, 11 ', 11', 11 '') and the pilot drill (12) form a single unit, and that the guide (17, 17 ', 17', 17 ', 17', 37 removable) is mounted on the shaft (11, 11 ', 11', 11 '').