| 摘要 |
A drill bit (10), and a cutter (28) for a drill bit, are provided, wherein the cutter (28) will encounter the formation with cutting surfaces of differing rake angles to optimize cutting efficiency. In most circumstances, the cooperating cutters (28) will have differing, positive, and negative or neutral rakes. Cutters (28) of differing rakes may be cooperatively paired on a drill bit (10) such that the portion of a formation (18) which is affected by the action of one cutter (28) may be similarly affected by the operation of the other cutters (28). <IMAGE> <IMAGE> |
