Auto-injector that can be filled from a vial

摘要

A syringe sub-assembly of an auto-injector has a housing 111 containing a sliding syringe chamber 112 with an exit aperture 114 connected to a needle 115. Within the chamber is a stopper 113 fixed to the housing. Slidably mounted on the housing is a docking sleeve or port 118 for receiving the head 120 of a vial 119. When the vial is moved into engagement with the sub-assembly (figure 3) it slides the port and the chamber to their most proximal extent, preferably compressing a spring within the housing. The vial couples with the port and, once the engaging force is removed, the chamber, port and vial are all propelled distally by the spring (figure 5). The relative motion of chamber and stopper draws in fluid from the vial. A drive subassembly is then attached to perform the injection.