CROWN BIT Russian patent published in 2012 - IPC E21B10/38 E21B10/60 

FIELD: mining.

SUBSTANCE: crown bit comprises a body with hard-alloy cutters and a hollow tail with axial and radial channels for supply of a cleaning agent, output holes of which are arranged above the end surfaces of hard-alloy cutters and are connected to grooves made on a side surface of the body. Its body is made with additional channels for supply of a cleaning agent that connect a tail cavity with a body end by longitudinal sludge-removal slots on the outer surface of the body and additional grooves at the body end, at the same time the sludge-removal slots are connected to main and additional grooves. Besides the main and additional grooves accordingly on the side surface and the body end are made on a section between radial and additional channels for a cleaning agent and sludge-removal slots and are directed relative to cleaning channels to a side opposite to direction of body rotation.

EFFECT: increased efficiency of operation.

2 cl, 2 dwg