| 摘要 |
PROBLEM TO BE SOLVED: To limit displacement per roll and prevent deterioration caused by repeated expansion and contraction in a specific portion in a spiral electric wire. SOLUTION: A cylinder member 1 made of a flexible material has a shape of bellows, an electric wire 10 is fixed to the peaks of a wave form and to a cylinder member 2 made of an elastic material, to constitute the spiral electric wire. When one end of the spiral electric wire is fixed and pulling force is applied to the other end, the bellows-shaped cylinder member 1 is extended, displacement per roll is made uniform, and fatigue caused by expansion and contraction in only the specific portion is prevented. |
