THREE-CONE ROLLING DRILLING BIT Russian patent published in 2011 - IPC E21B10/16 

FIELD: mining.

SUBSTANCE: drilling bit includes legs with parallel offset inclined trunnions, which are installed on them by means of retaining bearing of conical cutter with a crown; cast or milled teeth of the above legs are installed at an angle to longitudinal axis of trunnion. Each conical cutter is provided with teeth with right-hand and left-hand inclination. The above teeth are made so that axial load on bearing assembly of each bit cutter, which appears as a result of rock destruction force of inclined teeth of one cutter crown, can be compensated with axial force which had the same value and was opposite in direction and which appeared simultaneously at operation of the rest crowns of the same cutter, i.e. total constituent of axial force appearing as a result of rock destruction force with cutter crowns with inclined teeth at its sliding along the bottomhole on each bearing assembly of the bit shall be equal to zero.

EFFECT: higher operating efficiency of the bit by providing the hole making in the specified direction.

2 dwg