The liquid medicine (M) the automatic injector in order to prescribe dosage as for (1), in order the - injection needle (12), the plunger (9), and the syringe barrel (11) stopper in order to seal (10) could have to store the being full syringe (5), in order it is laid out substantially the housing of the cylindrical shape the syringe (5) proximal direction (P) to advance in order to interpose the needle in (2) and the - injection region, and the medicine (M) the plunger in order to make dosage the injection region displace (9) release possibly the coupling the Drive means which are done (8) withIt has. Drive means (8), after the injecting way the injection needle (12) you surround, in order the needle shroud (3) safe position (PS) to the plunger (9) from decoupling to be done in order to advance, it is laid out. According to this invention, Drive means (8), in order proximal direction (P) the thrust color (7) to turn at the time of translation, the 1st tongue (7.1) and the 1st crevice (6.2) through the slant face engagement section, in order the plunger (9) release possibly the coupling to be done, the thrust color which is laid out (7) it hits. The thrust color (7) 1st and/or the 2nd salient (7.2 and 7.3) guiding, the thrust color (7) in order to prevent revolution, the gap of one longitudinal direction (G1 and G2) is provided at least. The gap of circumferential direction (G3), when removing the automatic injector (1) from the injection region, the thrust color (7) coming off, the plunger (9) with engagement in order to make that it turns possible, it is laid out.< Choice figure > Drawing 3液体薬剤(M)の用量を投与するための自動注射器(1)は、- 注射針(12)、プランジャ(9)、およびシリンジ外筒(11)を封止するためのストッパ(10)を備える充済みシリンジ(5)を収容するように配置される実質的に円筒形のハウジング(2)と、- 注射部位に針を挿入するためにシリンジ(5)を近位方向(P)に前進させるため、および薬剤(M)の用量を注射部位に変位させるためのプランジャ(9)に解除可能にカップリングされる駆動手段(8)とを備える。駆動手段(8)は、注射後注射針(12)を囲むように針シュラウド(3)を安全な位置(PS)へ前進させるためにプランジャ(9)からデカップリングされるように配置される。本発明によれば、駆動手段(8)は、近位方向(P)の並進運動時にスラスト・カラー(7)を回転させるように、第1の舌部(7.1)および第1の凹部(6.2)
