| 摘要 |
<p>A drill bit includes a body which is rotatable, in use, about a body axis for drilling, and a cutting element 10 comprising a superhard portion 4 with a cutting face and fixed to an underlying substrate 5. The cutting element 10 is secured to the drill body so as to be moveable in a direction of movement when the drill bit is rotates, the cutting element 10 further being rotatable about a cutting element axis 7 thereof. The cutting element axis 7 extends away from the superhard material 4 through the substrate 5, and the cutting element axis 7 is tilted towards the direction of movement. The arrangement is such that the cutting element 10 has a leading surface (2a, fig 8) which bears against the formation and a trailing surface (2b, fig 8) which is spaced from the formation.</p> |
