Drillbit for mining and tunnelling is radially studded at an angle to drilling axis and set back from front studs in two-stage drillbit on carriage with drillrod feeder.

摘要

The drillbit (7) has additional studs (11) on its radial face (10) with the studs at an angle relative the drilling axis (14) and set back (11) from the bit front (12) studs (13) in the drilling direction. The drillbit is at the front of the carriage feeder unit used to set and withdraw the drillrods coupled from inner and outer pipes. Two leading studs at the front (12) of the bit stand axi-parallel to the drilling axis (14). The bit operates in two stages (15) graded (16) at an angle to the drilling axis (14). Studs (18) on radial face (10) are set back from the rear stage (15) in the direction of drilling.