Diamond-tipped drill bit for drilling machines has head with hemispherical recess and inner V-section groove for lubricating fluid delivered through inner channel

摘要

The drill bit is made with a head (10a) that has a hemispherical recess (10c) in its front face (10b), and a V-section groove (10d) in one side of the recess to receive a lubricating fluid delivered through a central channel (10e) in the shank of the bit. The diameter of the hemispherical recess open end is smaller than the diameter of the head, so that it leaves a peripheral crown (10f) round the outside of the head. The V-section groove has its sides at an angle of about 45 degrees.