DIAMOND DRILLING BIT Russian patent published in 2006 - IPC E21B10/46 

FIELD: rock cutting tools, particularly diamond drilling bits adapted for well drilling along with well purging with air or water-air mixtures.

SUBSTANCE: drilling bit comprises body and diamond-containing matrix connected to the body and provided with purging slots. Through orifices made as convergent-divergent channels with abrupt expanded sections located at body are formed along matrix contour. Inner matrix wall is cut and defines air discharge orifices. The matrix is provided with stiffening ribs arranged between convergent-divergent channels and supported by outer body wall.

EFFECT: increased wear resistance due to improved cooling ability.

4 dwg