CROWN BIT Russian patent published in 2013 - IPC E21B10/02 

FIELD: mining.

SUBSTANCE: crown bit comprises a crown ring, the end of which is divided by washing slots into sectors, reinforced with well and core forming cutters. The feature of the crown bit is the fact that well and core forming cutters are made in plan as rectangular trapezoids, the smaller bases of which are turned towards rotation of the crown. At the same time their inclined sides facing each other are made as concave or in the form of a straight line and are displaced in the radial direction one from another. At the same time side faces of well and core forming cutters in plan are serrated.

EFFECT: increased efficiency of crown bit operation.

4 cl, 5 dwg