PROBLEM TO BE SOLVED: To provide a clamper and an expansion and contraction mechanism, which can perform easily and definitely clamping and unclamping between an inner member and an outer member.SOLUTION: The clamper includes: a pair of clamp mechanisms which are inserted between an outer member and an inner member mounted to be linearly put in and out to the outer member, and are each configured to prohibit one relative movement in one direction among two directions of the inner member coming out and going into the outer member, while allowing the relative movement in the other direction, wherein their directions of prohibiting relative movements are opposite to each other and a unclamp mechanism for invalidating the mechanism of prohibiting the relative movement of the inner member to the outer member of the pair of the clamp mechanisms and allowing the relative movement of the inner member to the outer member.COPYRIGHT: (C)2013,JPO&INPIT【課題】インナー部材とアウター部材間のクランプ、アンクランプの操作を簡単に、かつ確実に行うことができるクランパ及び伸縮機構を提供する。【解決手段】アウター部材と、該アウター部材内に直線的に出し入れ可能に組み付けられるインナー部材との間に装着され、前記アウター部材に対してインナー部材が突出する方向と没入する方向の2方向のうち、一方向の相対移動を阻止し、かつ他方向の相対移動は許容する構成で、相対移動を阻止する方向が互いに逆方向の一対のクランプ機構と、前記一対のクランプ機構の前記アウター部材に対するインナー部材の相対移動を阻止する機能を、無効にして前記アウター部材に対するインナー部材の相対移動を可能とするアンクランプ機構と、を備えていることを特徴とする。【選択図】図1
