| 摘要 |
FIELD: mining. ^ SUBSTANCE: directed drilling system contains primary drill bit designed with possibility of rotation around axis of primary bit, pilot drill bit designed with possibility of rotation around axis of pilot bit being in fact parallel to axis of primary bit. Axis of pilot bit is in fact parallel to axis of primary bit and is displaced from axis of primary bit during operation, and to device for adjusting position of pilot bit axis in relation to primary bit axis. ^ EFFECT: improving system reliability. ^ 13 cl, 4 dwg |
