Patent ID: 8286736

Claim:
A drill bit defining a longitudinal center axis and including an axial trailing end configured for attachment to an end of an elongate drill rod, and an axial leading end including a pair of axially forwardly extending abutment elements, each abutment element having circumferential leading and trailing ends with reference to a direction of drilling rotation; each abutment element having an axially forwardly open slot formed therein for separating the respective abutment element into circumferential leading and trailing portions on which the circumferential leading and trailing ends are respectively disposed; each slot being situated closer to the circumferential leading end than to the circumferential trailing end, wherein the circumferential trailing portion is of greater width in the circumferential direction than is the circumferential leading portion; said slots being diametrically opposed and receiving respective drill tip portions which project axially forwardly from the respective slots; each circumferential trailing portion extending axially forwardly farther than the associated circumferential leading portion; each drill tip portion being secured by adhesive to the respective circumferential leading and trailing portions, wherein a substantial portion of a surface of the drill tip portion adjacent to the respective circumferential leading portion is in contact said respective circumferential leading portion.