| 摘要 |
The tool unit (12) is mounted on a rotary body (4) driven by a motor (9) and centrifugal force moves its cutting side (14, 16) in the direction of the tube, on the axis of rotation. The centre of mass (26) of the tool unit is positioned on a side of the axis of rotation diametrically opposite the cutting side through location of a weight (18), forming part of the tool unit and movable with it. A spring on the cutting side preferably acts on the tool unit against the weight. |
