PROBLEM TO BE SOLVED: To solve the problem that variations of discharged quantity of a medical fluid occur when the medical fluid is sucked in from a vial or an ampule and a portion of the medical fluid in a syringe is discharged from the needle of the syringe to remove air bubbles in the syringe, which is called as an air vent operation before injection.SOLUTION: In a quantitatively discharging container, a first groove part is formed in the longitudinal direction of either one of a syringe or a piston and a first protrusion part is formed on the other one and the first groove part and the first protrusion part are fitted in movably in the front and rear direction to each other and also a contact step part, which is in contact with the first protrusion part in the longitudinal direction, is provided on the first groove part and also the piston is constituted of a piston part and a pressing operation part and also a second groove part is formed in the longitudinal direction of either one of the piston part or the pressing operation part and a second protrusion part is provided on the other one and the second groove part and the second protrusion part are fitted in to be movable in the front and rear direction and to be rotatable to each other and also a contact step part, with which the second protrusion part is in contact, is provided in the longitudinal direction of the second groove part.COPYRIGHT: (C)2013,JPO&INPIT【課題】 バイアルやアンプルから薬液を吸引し、投薬に先立って、泡抜き動作と呼ばれる注射筒内の気泡を抜くため注射筒内の薬液の一部を注射針から排出する時、排出される薬液量にばらつきが発生していた。【解決手段】 シリンジ又はピストンの何れか一方の長手方向には第1溝部を形成し、他方には第1突出部を設け、前記第1溝部と第1突出部とを相対的に前後動可能に嵌挿させると共に、前記第1溝部には前記第1突出部と長手方向で当接する当接段部を設け、また、前記ピストンをピストン部と押圧操作部とから構成すると共に、それらピストン部、又は押圧操作部の何れか一方の長手方向には第2溝部を形成し、他方には第2突出部を設け、それら第2溝部と第2突出部とを相対的に前後動、且つ、回転可能に嵌挿させると共に、その第2溝部には第2突出部が当接する当接段部を長手方向に設けた定量吐出容器。【選択図】 図1
