Patent ID: 8240404

Claim:
A rotary mine roof drilling bit, comprising: a bit body intermediate a shank and a working surface, the shank being adapted for attachment to a driving mechanism; the working surface comprising a plurality of polycrystalline diamond enhanced cutting elements comprising a carbide substrate bonded to the diamond at a non-planar interface; carbide bolsters disposed intermediate the bit body and the plurality of cutting elements; and at least one of the plurality of the cutting elements comprises a pointed geometry that comprises a 0.050 to 0.125 inch radius and a thickness greater than 0.100 inches; wherein the carbide bolsters comprise a substantially straight cylindrical portion at least mostly disposed below the surface of the bit body, a top end and a bottom end, the top end narrowing from the cylindrical portion with a substantially annular concave curve to a planar interface adapted for bonding to a carbide substrate, and the bottom end narrowing from the cylindrical portion to a stem.