DRILL BIT Russian patent published in 2009 - IPC E21B10/02 

FIELD: mining.

SUBSTANCE: present invention pertains to drill bits meant for drilling with continuous removal of core material. The drill bit has a body with a working end, which is fitted with well and core-forming cutters, displaced from diametral planes, parallel their cutting edges, to the side opposite the direction of rotation of the drill bit, and slanted radial channels, linking the inner cavity of the body with an annular space through mud outlet grooves at the end of the body. The bottom of the mud outlet grooves at the working end is in form of Archimedes' spiral. Their surface area along the groove on the side of the centre increases according to the following relationship: S₁/S₂=a·I₁/I₂, where S₁ and S₂ - is the cross sectional area of the radial groove at distance I₁ and I₂ from the outer diameter of the drill bit on the side of the centre, a=(0.9-1.3) is a proportionality constant, which depends on physical and mechanical properties of the drilled rocks and diameter of the drill bit.

EFFECT: increased efficiency of the drill bit.

2 dwg