DRILL BIT Russian patent published in 2007 - IPC E21B10/16 

FIELD: rock-cutting tools, particularly cone drilling bit cutting structures.

SUBSTANCE: drill bit comprises cutters provided with central, pre-peripheral and peripheral steel milled teeth crowns and reaming gage hard-alloy teeth. Cutter having the longest peripheral crown teeth has additional hard-alloy teeth arranged at valley bottoms between peripheral teeth in staggered order with respect to reaming gage teeth so that the additional hard-alloy teeth flush with inner ends of peripheral crown teeth. Cutter having pre-peripheral crown has additional hard-alloy teeth installed on valley bottoms between pre-peripheral crown teeth so that the additional hard-alloy teeth are flush with inner ends of teeth thereof.

EFFECT: increased service life and penetration speed due to improved uniformity of drilling bit cutting structure strength reserve distribution along drill bit radius.

5 dwg