DRILL TOOL Russian patent published in 2014 - IPC E21B10/56 

FIELD: mining.

SUBSTANCE: drill tool comprises body with holes to receive inserts including stepped cylindrical stem with lengthwise groove at its end, working head and insert retainer composed of the bush fitted in the body bore with interference larger than that of the root in bush and aligned with root and rod bush fitted in aligned grooves, Insert stem has though radial channel connected with its lengthwise grove, Channel diameter corresponds to rod crosswise size and exceeds the stem lengthwise groove sixe. The channel is shifted from stem end towards the insert working head.

EFFECT: higher reliability of coupling.

2 dwg