| 摘要 |
Free ends of cables (6,6') of the counterweight system are attached to coiling drums (31,32), between which is a torsion spring (4). One free end is linked to one of the drums and the other free end is linked to the spindle (7) carrying the drums. Between the spindle and the torsion spring is at least one spacer member (9). Preferably the outside diameter of the spacer member is smaller than the inside diameter of the torsion spring. A protective tube (5) can be fixed over the torsion spring and the free ends of the coiling drums. |
