THREE-CONE ROCK BIT Russian patent published in 2010 - IPC E21B10/16 

FIELD: mining.

SUBSTANCE: rock bit cones are equipped with central and peripheral crowns of hard-alloy cogs. At one cone, peripheral crown is single-row, at the other - double-row with staggered arrangement of cogs in peripheral and pre-peripheral rows, at the third one - double-row with group arrangement of staggered cogs with pre-peripheral row cogs arranged pairwise between groups. At inverted tapers of cones, in the clear of peripheral crown cogs there are through slots arranged with depth of not less than cones barrier relative to legs. Width of slots on the first cone equals distance in the clear between bases of peripheral row cogs, and at the second and third cones it equals diametre of pre-peripheral row cogs. In each slot of the second and third cones, apart from slots opposite to pairwise cogs of per-peripheral row, in the clear of peripheral row cogs with displacement by two thirds of angular pitch in direction opposite to direction of cone rotation, and at equal distance from slot boards there are auxiliary cogs installed, one for each, normally towards surface of slots and aflush with surface of inverted cone and cone end. At the third cone in the clear of pairwise cogs of pre-peripheral row, at the ledges between cogs, there are cutting cogs installed, at the same time in slots adjacent to them normally to their surfaces and at the same distance from slot sides there are auxiliary cogs installed, one for each, aflush with surfaces of inverted taper and with external surface of cone body.

EFFECT: improved efficiency of well wall damage and wear resistance of inverted tapers of cones with artificial change of well curvature through development of radial load at rock bit.

13 dwg