The present invention relates to a power unit for a medicament delivery device comprising a power body (24) having opposite proximal and distal ends, a plunger rod driver (44) coaxial and movably arranged in relation to said power body, a plunger rod (72) coaxial and movably arranged in relation to said plunger rod driver, a force spring element (78) operably connected between said plunger rod (72) and said power body wherein the plunger rod driver comprises first holding elements (66, 68) arranged to interact with second holding elements (76) on said plunger rod (72) and with the power body for releasibly holding said plunger rod (72) with said force spring element (78) in an injection tensioned state third holding elements (56) arranged to interact with fourth holding elements (41) on said power body (24) for releasibly holding said plunger rod driver in a penetration tensioned state first attachment elements (52) arranged to interact with second attachment elements (108) on a medicament container holder (92), capable of attaching the two attachment elements together and first blocking elements (62) arranged to interact with second blocking elements (43) on said power body (24), for blocking any movement of said plunger rod driver (44) in the distal direction after the plunger rod driver is released from a penetration tensioned state.本發明係關於一種用於藥劑輸送裝置的動力單元,其包含一動力本體(24),其具有相反的近端及遠端、一柱塞桿驅動器(44),其相關於該動力本體被同軸地且可活動地設置、一柱塞桿(72),其相關於該柱塞桿驅動器被同軸地且可活動地設置、一施力彈簧件(78),其被可操作地連接在該柱塞桿(72)和該動力本體之間;其中該柱塞桿驅動器包含第一固持件(66,68),其被設置來和該柱塞桿(72)上的第二固持件(76)及和該動力本體互動,用以在一注射緊繃狀態下用該力彈簧件(78)來可釋放地固持該柱塞桿(72);第三固持件(56)其被設置來和該動力本體(24)上的第四固持件(41)互動,用以在一刺入緊繃狀態下可釋放地固持該柱塞桿驅動器;第一附裝件(52),其被設置來和一藥劑容器固持器(92)上的第二附裝件(108)互動,其能夠將兩個附裝件附著在一起;及第一阻擋件(62),其被設置來和該動力本體(24)上的第二阻擋件(43)互動,用以在該柱塞桿驅動器從一刺入緊繃狀態被釋放之後阻擋該柱塞桿驅動器(44)在朝向遠端的方向上的任何運動。10‧‧‧外殼24‧‧‧動力本體44‧‧‧柱塞桿驅動器72‧‧‧柱塞桿78‧‧‧施力彈簧件88‧‧‧藥劑容器90‧‧‧引導銷92‧‧‧藥劑容器固持器118‧‧‧藥劑輸送件罩殼136‧‧‧藥劑輸送件罩殼施力件144‧‧‧端壁
