ROLLING DRILLING BIT Russian patent published in 2010 - IPC E21B10/08 

FIELD: mining.

SUBSTANCE: invention concerns rock destruction tool, namely small-diametre rolling drilling bits. Rolling drilling bit includes legs and cutters, which are installed on trunnions with thrust shoulders at the bottom. At that, inner backs of legs are formed with two crossing planes, one of which is parallel to the trunnion shoulder, and the other one forms together with the shoulder plane an acute angle with the top at the crossing point of jointing plane of legs with the shoulder plane. Acute angle α value is determined by mathematical formula.

EFFECT: improving operating reliability of the bit and simplifying its manufacturing technology.

1 dwg