US Patent 9028453 Reusable auto-injector

An injection device comprises a first sub-assembly. The first sub-assembly comprises a chamber for holding a fluid. The chamber comprises an inner surface and an exit aperture. The first sub-assembly comprises a stopper movably disposed within the chamber and having an outer surface substantially in contact with the inner surface about its perimeter. The first sub-assembly comprises an adapter adapted to transfer fluid into the chamber.