PROBLEM TO BE SOLVED: To provide a buffer capable of easily changing a relative position of an outer cylinder and internal member.SOLUTION: A buffer 9A includes a communication passage 9d communicating between an internal space 4a of a support rod pipe 4 and the outside, a valve body 9e covering an opening part 9d1 of the communication passage 9d, and a communication hole 9e1 having a smaller diameter than the communication passage 9d. In insertion operation of an upper stage pipe 5 to the support rod pipe 4, the valve body 9e closes the opening part 9d1, and then air in the internal space 4a flows to the communication passage 9d through the communication hole 9e1. In pull-out operation, the valve body 9e opens the opening part 9d1, and then air in the communication passage 9d directly flows to the internal space 4a.SELECTED DRAWING: Figure 3COPYRIGHT: (C)2017,JPO&INPIT【課題】外筒と内部材との相対位置を変化させやすい緩衝装置を提供する。【解決手段】緩衝装置9Aは、支柱パイプ4の内部空間4aと外部とを連通させる連通路9dと、連通路9dの開口部9d1を覆う弁体9eと、連通路9dよりも小径の連通孔9e1とを備える。上段パイプ5の支柱パイプ4への挿入動作時には、弁体9eが開口部9d1を閉鎖し、連通孔9e1を介して内部空間4aの空気が連通路9dへ流れる。引き抜き動作時には、弁体9eが開口部9d1を開放し、連通路9dの空気が直接内部空間4aへ流れる。【選択図】図3
