DIAMOND CROWN BIT Russian patent published in 2013 - IPC E21B10/48 

FIELD: mining.

SUBSTANCE: diamond crown bit comprises a body and a matrix separated by wide and narrow washing slots into working sectors of different length, larger of which are reinforced with large diamonds compared to sectors of smaller length. Sectors of larger length are equipped with communicated additional washing slots at the end and side surfaces and are equipped with well and core-calibrating inserts with a flat side face, every of which is matched with a slack side of additional side slots. As a version, additional washing slots at the end of long sectors are arranged in the form of a spiral of Archimedes, the convex part of which is directed towards the external surface of the crown body. As a version, additional washing slots on side surfaces of long sectors are arranged as inclined to a longitudinal axis of the crown for directing the flow of washing liquid to the side opposite to direction of crown rotation.

EFFECT: invention provides for optimal arrangement for washing of matrix of sectors with larger length, increased efficiency of crown operation, increased drifting and mechanical speed of drilling.

3 cl, 1 dwg