| 摘要 |
<p>A roof-bolt drill bit has a bit body rotatable about a central axis and at least one coupling pocket defined in the bit body. At least one coupling pocket is defined in the bit body, the at least one coupling pocket being defined by a pocket back surface, a first pocket side surface having a substantially planar surface extending from the pocket back surface, and a second pocket side surface having a substantially planar surface extending from the pocket back surface, the second pocket side surface being nonparallel to the first pocket side surface. The first pocket side surface extends at an angle of between approximately 45° and approximately 90° relative to the second pocket side surface and the first pocket side surface and the second pocket side surface are separated from one another.</p> |
