DRILLING BIT Russian patent published in 2006 - IPC E21B10/02 

FIELD: well drilling equipment, particularly drill bits adapted to drill in fractured ground and in ground of variable hardness.

SUBSTANCE: drilling bit comprises body with cuts made in lower part thereof and inclined in direction opposite to body rotation direction. The cuts divide drilling bit into sectors reinforced with cutters. The drilling bit also has guiding bush arranged in body interior. The bit is provided with additional bush arranged from outer body side and coaxial with guiding bush. The guiding bush has inclined radial channels to communicate bit interior with cavity defined by guiding and additional bushes. Radial channels may be aligned with inclined body cuts.

EFFECT: increased drilling bit durability due to prevention of body sectors displacement in radial direction and due to improved face cleaning of sludge.

2 cl, 2 dwg