| 摘要 |
Disclosed herein is a rotary-percussion earth boring bit that has an improved geometric configuration to minimize fatigue failures and reduce manufacturing costs. The body of the bit is formed of a single mass of metal through which extends a single air course, without intermediate deflection or intersection, from a central portion of the upper, anvil surface to the face of the bit. The air course intersects this face in an off-set relationship with the axis of rotation of the bit. Button type inserts are included in the face and one insert is adjacent to both the air course and the centerline of the bit.
|
