Percussion drill bit

A percussion drill bit adapted for drilling particularly hard matter such as rock, comprising:

• a. a substantially solid body having a relatively flat face at its forward end, and the face including three plateaus separated by three radial relief channels of substantial depth, with the outer ends of said relief channels intersecting major spiral grooves extending along the sides of the bit, and the cross-sectional areas of said relief channels and the major grooves being approximately the same at their intersection, and the sides of said body constituting a frustram of a cone, with the narrow portion of the cone being at the base of the body, and the face of said body further having a circular center portion which is recessed with respect to the plateaus, with the diameter of said center portion being about one-third of the diameter of said body;
• b. a flow passage extending through the body of the drill bit for the delivery of drilling fluid to the face of the bit, and said passage terminating on the face within the recessed center;
• c. a plurality of hardened inserts widely distributed across the face and protruding therefrom, with the radial spacing of said inserts with respect to the longitudinal axis of the body being such that there is an overlap of the tracks of each insert by the track of another insert as the body is rotated about its longitudinal axis, whereby there is essentially no portion of the rock area underneath a drill bit that is not subject to being contacted by a hardened insert;
• and
• d. a plurality of relatively shallow minor grooves extending spirally and rearwardly along the sides of the bit from a region near the face of the bit to the base thereof, with there being at least one minor groove extending adjacent each of the major grooves along the sides of the bit.

A percussion drill bit adapted for drilling particularly hard matter such as rock comprising:

• a. a substantially solid body having a relatively flat face at its forward end, and the face including a plurality of plateaus separated by radial relief channels, with the outer ends of said relief channels intersecting major spiral grooves extending along the sides of the bit, and the cross-sectional areas of said relief channels and the major grooves being approximately the same at their point of intersection, and the sides of said body constituting a frustrum of a cone having an included angle of about 14.degree. , with the narrow portion of the cone being at the base of the body, and the face of said body further having a center portion which is recessed with respect to the plateau portion;
• b. a plurality of flow passages extending through the body of the drill bit for the delivery of drilling fluid to the face of the bit, and said passages terminating on the face near either the relief channels or the recessed center;
• and
• c. a plurality of hardened inserts widely distributed across the face and protruding therefrom, with the configuration of each plateau and its associated inserts being slightly different than the other plateaus and their associated inserts.

A percussion drill bit adapted for drilling particularly hard matter such as rock, comprising:

• a. a substantially solid body having a relatively flat face at its forward end, and the face including a plurality of plateaus separated by radial relief channels, with the face of the bit being divided by three relief channels so as to provide three plateaus, and there being at least one of the plateaus with a size which is significantly different from the other plateaus, with the outer ends of said relief channels intersecting major spiral grooves extending along the sides of the bit, and the cross-sectional areas of said relief channels and the major grooves being approximately the same at their point of intersection, and the sides of said body constituting a frustrum of a cone having an included angle of about 14.degree., with the narrow portion of the cone being at the base of the body, and the face of said body further having a center portion which is recessed with respect to the plateau portions;
• b. a plurality of flow passages extending through the body of the drill bit for the delivery of drilling fluid to the face of the bit, and said passages terminating on the face near either the relief channels or the recessed center;
• and
• c. a plurality of hardened inserts widely distributed across the face and protruding therefrom.