Patent ID: 6276467
Filing Date: 2001-08-21
Classification: E21B

Abstract:
A percussive rock drill bit comprising:a bit body forming a front cutting face and a peripheral surface, at least one passage intersecting the front cutting face for conducting a flushing/cooling medium to the front cutting face, the peripheral surface having circumferentially spaced flushing grooves formed therein, portions of the bit body disposed between successive flushing grooves comprising wings, each wing having a leading edge and a trailing edge;a plurality of button inserts mounted in the bit body, the button inserts formed of a material harder than the material of the bit body, some of the button inserts constituting gauge inserts and mounted in the wings, there being only one gauge insert mounted in each wing, wherein the cutting face includes a radial channel associated with the at least one passage for conducting flushing/cooling medium from the passage to one of the flushing grooves, one of the wings being situated immediately behind the one flushing groove, the gauge insert mounted in the one wing constituting an offset gauge insert which is offset circumferentially from a center of the one wing in a direction away from the leading edge, by a distance equal to at least five percent of a circumferential length of the wing.