| 摘要 |
A directable boring bar 1 has an inner rotatable portion 3 and an outer stationary portion 4 mounting inclination meters 14. Control rails 9 extending along the bar 1 are moved outwards by hydraulic rams 10, 11 to control the direction of the bar. Hydraulic pressure and electrical power are generated from the rotation of the inner portion 3. <IMAGE> |
