| 摘要 |
An autoinjector (100) for expelling a single dose of drug from a held cartridge (600) comprising a piston (630), the autoinjector comprising: a) a base (200, 220), b) a needle (500) that is fixedly mounted relative to the base (200, 220), c) a plunger (310, 320, 400) adapted for cooperation with the piston (630), d) an actuating spring (330) arranged to act on the plunger (310, 320, 400) to drive the piston (630) distally, and e) a needle shield (350, 380) axially movable relative to the base (200, 220) between an extended position and a collapsed position. In an initial state, a thread (325) of the plunger (310, 320, 400) engages a base thread (205) to maintain the plunger in an initial axial position. The autoinjector defines a lock (320, 328, 380, 388) that is released when the needle shield (350, 380) is moved from the extended position to the collapsed position. The lock (320, 328, 380, 388) releases to enable relative rotation between plunger thread (325) and base thread (205) causing release of the plunger (310, 320, 400) from the initial axial position and expelling the dose of the drug. |
