| 摘要 |
FIELD: mining.SUBSTANCE: drill bit comprises a housing with central and lateral channels for the passage of the washing agent to the peripheral rock cutting inserts mounted in the housing, and a centring coal-cutting bit mounted in a central hole made in the leading part of the housing. In the housing along the generator of the cylindrical surface of its central hole the longitudinal channels are formed, with which the said central channel is connected to the surface of the central leading part of the housing, forming the cams in the area of the said central hole.EFFECT: improvement of efficiency of the drill bit operation, improvement of cleaning from drill cuttings, and ensuring stability of conditions of fastening the central coal-cutting bit by cooling the central leading part of the housing.2 cl, 2 dwg |
