Expansion / contraction device and elevating device provided with the expansion / contraction device

摘要

PROBLEM TO BE SOLVED: To provide a stretchable device having a simple configuration which can suppress a fluid amount in the stretchable device from exceeding a predetermined amount.SOLUTION: A stretchable device 1 includes: a stretchable member 2 which can stretch and shrink; a fluid pipe 3 connected to the stretchable member 2 and that supplied a fluid into the stretchable member 2; and a filling amount controlling mechanism 4 for controlling a supply of the fluid into the stretchable member 2 when the stretchable member 2 reaches a predetermined stretched state. The filling amount controlling mechanism 4 includes a discharge member 41 provided to the fluid pipe 3 and a moving member 42 which moved according to a change in volume of the stretchable member 2. The discharge member 41 includes a discharge part 41a which a discharge the fluid in the fluid pipe 3 to outside of the fluid pipe 3, and a switching part 41b which can switch between a discharge state in which the fluid is discharged from the discharge part 41a and a close state in which the discharge part 41a is closed.SELECTED DRAWING: Figure 1