PROBLEM TO BE SOLVED: To provide a positioning member which can surely position a plunger to a barrel, and can prevent the plunger from falling from the barrel when being removed in a syringe made of glass.SOLUTION: This positioning member 1 is equipped with a holding section 11 which is fitted on the barrel 3, an extended section 12 which is extended to the proximal end side, a proximal end side suppressing section 13 on the proximal end side of a flange section 44 on the plunger side, and a flank side suppressing section 14 which projects forward from the distal end of the proximal end side suppressing section 13. The extended section 12 has a front side suppressing section 12a which comes into contact with the front surface of the flange section 44. When the positioning member 1 is pulled in a direction shown by arrow under a state shown by the figure, the flank side suppressing section 14 cannot be removed by coming into contact with the flange section 44, and therefore, the plunger 4 can be prevented from falling. When the positioning member 1 is removed, the plunger 4 moves to the barrel 3 side if the state that the top and the bottom shown in the figure are reversed is made, and the positioning member 1 can be removed as the flank side suppressing section 14 does not come into contact with the flange section 44 even when the positioning member 1 is pulled in the direction shown by the arrow.COPYRIGHT: (C)2010,JPO&INPIT【課題】ガラス製のシリンジにおいて、バレルに対してプランジャを確実に位置決めでき、取り外す際にはバレルからプランジャが落下しないようにできる位置決め部材を提供する。【解決手段】位置決め部材1は、バレル3に装着される保持部11と、基端側に延出される延出部12と、プランジャ側のフランジ部44の基端側の基端側抑止部13と、その先端から前方に突出する側方側抑止部14とを備える。延出部12は、フランジ部44の前面に当接する前方側抑止部12aを有する。図の状態で位置決め部材1を矢印の方向に引くと、側方側抑止部14がフランジ部44に当接して取り外せないため、プランジャ4の落下を防止できる。位置決め部材1を取り外す際には、図の上下を逆にした状態にすれば、プランジャ4がバレル3側に移動し、位置決め部材1を矢印の方向に引いても側方側抑止部14がフランジ部44に当接することなく取り外すことができる。【選択図】図3
