| 摘要 |
PURPOSE:To improve the state of contact between a driving cable and a driving shaft and prevent a trouble such as abnormal wear, etc. by providing the cable contact part of the driving shaft with an opening in which a connecting portion is placed. CONSTITUTION:An electrode 10 is hung by a driving wire 30 through the medium of a connecting portion 20. The driving wire is wound around a pulley 40. A part of the pulley is provided with an opening 42 in which the connecting portion 20 is entirely placed. As a result, the connecting portion 20 and the pulley 40 do not strongly rub each other and are protected from abnormal wear. To provide the driving shaft with the opening in which the connecting portion is placed, some gears are nicked, the gap between gears is increased to keep the connecting portion out of contact with the gears, a recess is provided on the driving shaft, or the like is effected. |
