Patent ID: 9359821
Filing Date: 2016-06-07
CPC Classification: E21B

Claim Text:
1. A drill bit comprising: a bit body, including an outer bit body and an inner bit body rotationally secured to the outer bit body, wherein the outer bit body surrounds the inner bit body; a plurality of annular blades coupled to the outer bit body; a plurality of gauge pads coupled to the outer bit body and defining an outer cutting diameter; a circumferentially continuous gauge ring coupled to the outer bit body and defining an inner cutting diameter, wherein the plurality of annular blades includes a cutting face that extends from the outer cutting diameter to the inner cutting diameter; an inner cutting structure formed on the inner bit body and recessed into the outer bit body, wherein the inner cutting structure has a maximum diameter substantially equal to the inner cutting diameter; and a junk slot disposed across the outer bit body between two adjacent annular blades, wherein the junk slot provides a conduit to move formation cuttings from the inner cutting structure to an outer surface of the bit body.