Patent ID: 9133667
Filing Date: 2015-09-15
Classification: E21B

Abstract:
1. A drill bit for drilling a hole through earth and hard materials, said drill bit comprising: a bit body having a first end, a second end spaced apart from said first end, a middle section between said first end and said second end, said bit body having a longitudinal axis, said bit body including a bore extending from said first end towards said second end; a connection means configured to couple said bit body to a rotation means for providing rotational torque to said bit body, said connection means being located at said first end; a cutting head at said second end, said cutting head including: a plurality of cutters, each of said cutters having a cutter tip centered about a cutter axis and terminating in a cutter point, each of said cutters being mounted into a cutter receptacle at an individual pitch angle relative to said cutting face and with said cutter tip being pointed in a direction of intended rotation of said drill bit, said pitch angle being measured between a reference line in the direction of intended rotation in the plane perpendicular to said longitudinal axis of said bit body and said cutter axis, said individual pitch angles each being an acute angle opening away from said reference plane, wherein at least one cutter has a first individual pitch angle different from at least one other cutter; and said plurality of cutter points together defining a projected cutting surface.