| 摘要 |
In one aspect of the invention a rotary mine roof drilling apparatus has an arm attached to and intermediate a drill bit and a platform. The apparatus also has a thrusting mechanism adapted to push the drill bit into a mine roof. The drill bit has a bit body intermediate a shank and a working surface. The working surface has a cutting element with a carbide substrate bonded to a diamond working end with a pointed geometry; and the diamond working end has a 0.050-0.200 inch apex radius.
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