METHOD FOR INCREASE OF LIFE TIME OF A DRILL CROWN

摘要

A method for increase of time life of a drill crown consists in that the surface that destructs the rock is equipped with hard-alloy cutters with openings of frontal and side washing, and connection section with inner left or round-support thread is placed with displacement towards the depth of the crown, with formation of thread-free section. Additionally for the thread-free section diameter is set as equal to diameter of the drill rod column or diameter of circle described round the n-hedron of the rod column at its n-facet realization, with provision of the length of the section enough to cover the surface of the column at the place of its transition to pre-thread section.