CONE DRILL BIT FOR REACTIVE TURBODRILLING Russian patent published in 1997 - IPC

FIELD: cone drill bits for drilling wells of large diameter, mainly, in rocks of mean and high hardness. SUBSTANCE: cone drill bit has body and roller cutters attached to inclined pins with nose, middle and peripheral teeth rows, reinforced working members. Half of taper angle β_o of nose teeth row of each roller cutter is connected with angle of inclination Φ_o of pin axis to axis of drill bit by relation β_o=90 deg - Φ_o, and taper angles of middle teeth row 2β₁ and peripheral 2β₂ are reducing in direction of from nose teeth 2 row to peripheral one. Half of taper angle of middle and peripheral teeth rows are determined by formulas given in the invention description. EFFECT: higher efficiency. 2 dwg