| 摘要 |
PURPOSE:To prevent the distortion of a strut when a leader turns by a method in which a stopper having a pin whose projection length can be adjusted by shims is provided between the upper ends of struts and the movement of the struts is stopped. CONSTITUTION:When a leader 27 turns inside a holder 33, the holder 33 also is about to turn and struts 34 and 35 also are about to turn around the lower fitting portion (not illustrated). However, since skirts 41A and 41B whose projection length is adjusted by shims 46A and 46B on both ends of the pin 42 of a stopper 40 come into contact with the brackets 35A and 35B of the struts 34 and 35 and the rotation of the struts 34 and 35 is stopped, the distortion of the struts 34 and 35 can be prevented. Since, when the height of the leader 27 is increased, the distance between the struts 34 and 35 becomes smaller, the shims 46A and 46B are exchanged with thin ones to make the apertures between the skirts 41A and 41B of the pin 42 and the brackets 34A and 35B proper. Inversely, when the leader is lowered, the shims 46A and 46B are exchanged with thick ones. |
