US Patent 10052436 Automatic injection device

A medicament injection device arranged to receive a replaceable container subassembly includes front and rear housings releasably connectable to each other. A reloadable drive mechanism is accommodated in the rear housing for acting on the plunger of a replaceable container subassembly for expelling medicament. A needle hider front is slidably arranged within the front housing. A needle shield remover is arranged to connect with a needle shield of the replaceable container subassembly and to be removably inserted into a proximal end of the front housing through the needle hider front. The needle shield remover is adapted to interact with the reloadable drive mechanism such that a user can reload the drive mechanism.