Annular core bit for drilling hard substances comprises a core bit body provided on its inner/outer side with a groove that extends over the length of the core bit body and ends in the region of an abrasive material or rinsing medium inlet

摘要

Annular core bit, especially a diamond core bit (2), comprises a tubular core bit body (6) defining a cylindrical cavity (14) for a drilling core. The free end of the core bit is coated with an abrasive material (10) and the opposite-lying end is provided with an inlet (26) for feeding liquid or gaseous rinsing medium into the cavity. The core bit body is provided on its inner side (16) facing the cavity and/or on its outer side (18) facing away from the cavity with at least one groove (40, 42) that extends over the entire axial length of the core bit body and ends in the region of the abrasive material or the inlet. Preferred Features: The groove extends in a helical line over the inner and/or outer side of the core bit body.