PROBLEM TO BE SOLVED: To provide a metered-dose sprayer of syringe shape which dispenses the content in small quantities.SOLUTION: A plunger has a piston holding member 40 having a piston, and a plunger operation member 50 positioned at the rear end of the holding member. The holding member includes a holding portion body 41 for holding the piston, the holding portion body is integrally provided with a shaft 42 integrally extending backward, and a plurality of arms 43 opposed to each other across the shaft and deformed and restored, and the arm is provided with a sliding projection 44 and a locking projection 45. The operation member is formed with an inner space R2 for housing the shaft and a notch 54, the notch has a butting end surface 55 formed as a pressing surface for pressing a free end 43e of the arm, restricting the arm between the butting end surface and the syringe, and generating flexible deformation from the sliding projection. When the pressing is released, the plunger operation member is pushed back by a restoration force starting from the sliding projection elastically deformed, and the locking of the locking projection is released.COPYRIGHT: (C)2014,JPO&INPIT【課題】内容物を小分けして取り出すことのできる、定量シリンジ型噴出器を提供する。【解決手段】プランジャは、ピストンを有するピストン保持部材40と、保持部材の後端にプランジャ操作部材50とを有する。保持部材は、ピストンを保持する保持部本体41を備え、保持部本体に、後方に向かって一体に伸びるシャフト42と、シャフトを挟んで対向する変形及び復元が可能な複数のアーム43が一体に設けられているとともに、アームに摺動突起44と係止突起45が設けられている。操作部材は、シャフトを収納する内部空間R2と切欠き54を形成し、切欠きの突き当たり端面55を、アームの自由端43eを押圧してアームをシリンジとの間で拘束することで摺動突起を起点にした撓み変形を生じさせる押圧面に形成し、当該押圧の解除に伴いプランジャ操作部材が撓み変形の摺動突起を起点にした復元力によって押し戻されることで、係止突起の係止を解除する。【選択図】図3
