The present disclosure relates to a administration assembly for a medicament delivery device, comprising: an elongated tubular delivery member cover (7), a cartridge holder (11) having a cartridge blocking protrusion (11b) configured to prevent the medicament cartridge (31) from moving proximally until being subjected to a proximally directed force, a needle assembly (13) comprising a double-edged needle having a proximally extending needle portion (13a) and a distally extending needle portion (13b), wherein the needle assembly (13) is configured to be assembled with the cartridge holder (11) so that the distally extending needle portion (13b) extends into the cartridge holder (11), and an administration mechanism including a plunger rod (27) configured to be proximally biased, wherein the delivery member cover (7) is configured to be linearly displaced in the distal direction relative to the cartridge holder (11), and wherein the delivery member cover (7) is configured to activate the administration mechanism when moved in the distal direction, causing the administration mechanism to move the cartridge holder (11) in the proximal direction and to subsequently move the plunger rod (27) in the proximal direction inside the cartridge holder (11) with a force larger than a threshold value.本發明關於一種用於藥物輸送裝置的施用組合體。該施用組合體包含：修長管狀輸送構件遮蔽件(7)；匣保持器(11)，具有匣阻擋凸部(11b)，該匣阻擋凸部被建構用於防止藥物匣(31)朝近側運動，直到藥物匣受到朝近側的力為止；針組合體(13)，包括雙刃針，該雙刃針具有近側延伸針部(13a)和遠側延伸針部(13b)，其中該針組合體(13)被建構用於被組合於該匣保持器(11)，使得該遠側延伸針部(13b)延伸進入該匣保持器(11)；和施用機構，包括柱塞桿(27)，該柱塞桿被建構用於朝近側偏壓。其中該輸送構件遮蔽件(7)被建構用於相對於該匣保持器(11)朝遠側方向線性位移；且其中該輸送構件遮蔽件(7)被建構用於當該輸送構件遮蔽件朝該遠側方向運動時，啟動了該施用機構，造成該施用機構朝該近側方向運動該匣保持器(11)，且接下來以大於臨界值的力將該匣保持器(11)內側的該柱塞桿(27)朝該近側方向運動。
