Patent ID: 7766103

Claim:
A drill bit rotatable about a drilling axis, comprising: a bit body including a reamer part; a leading end and a trailing end spaced apart in a direction of the drill axis; and a plurality of first rock machining means disposed on the reamer part, wherein the plurality of first rock machining means include, relative to a direction of rotation, a leading first rock machining means and at least one trailing first rock machining means, the leading first rock machining means and the trailing first rock machining means are angularly spaced apart from one another about the drill axis, wherein at least one of the trailing first rock machining means is also axially spaced from the leading first rock machining means in a direction towards the leading end of the drill bit, and wherein the bit body has an outer surface extending between said leading and trailing ends and which, in a cross-section perpendicular to the drilling axis, is not uniformly radially displaced from the drilling axis, the outer surface incorporating a bearing region which forms the outermost radial part of the outer surface, wherein the bearing region extends angularly about the drilling axis.