| 摘要 |
A roller cutter rock bit includes a cutter constructed with a relief adjacent the cutter heel and gage inserts which each include elongated gage and bottom hole cutting edges which are separated from each other by an obtuse included angle. The edges serve to cut both the bottom of the borehole and the wall when changing the direction of drilling. Both the gage cutting edge and the bottom cutting edge of each gage insert are shaped so as to aggressively cut formation material.
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