| 摘要 |
<p>The tool holder pref. rotated by a fluid turbo motor is provided with a part circular shoe pivotally mounted at the end remotre from the tool and extending longitudinally along the holder towards the tool. The outer surface of the shoe engages the bone wall during boring and the shoe is provided with cylinders moveable under pressure, transversely of the axis of rotation against the tool holder thereby to apply a transverse force to the tool.</p> |
