Patent ID: 6176332
Filing Date: 2001-01-23
Classification: E21B

Abstract:
A rotatable cutting bit for penetrating an earth formation, the rotatable cutting bit comprising:an elongate bit body having a forward end and a rearward end, the bit body defining a peripheral surface;the bit body having a first cutting insert affixed thereto at the axially forward end thereof, and the first cutting insert having a first leading cutting edge and a first side clearance cutting edge;the first cutting insert being attached to the bit body so that the first side clearance cutting edge radially extends past the peripheral surface of the bit body so as to engage the earth formation;at least a portion of the first leading cutting edge being arcuate;the first cutting insert includes a top surface and a leading surface, the leading surface and the top surface intersecting so as to define the leading cutting edge at the intersection thereof; and a bevelled surface and the leading surface intersecting so as to define the first side clearance cutting edge at the intersection thereof.