US Patent 11559630 Auto-Injector

An auto-injector for administering a dose of a liquid medicament (M) is presented having an elongate case, a carrier subassembly comprising a tubular carrier slidably arranged inside the case, where the carrier adapted to contain a syringe with a hollow injection needle. The injector also has, a drive spring and a plunger for forwarding load of the drive spring to a stopper of the syringe, wherein the syringe is lockable for joint axial translation with the carrier. A control spring is arranged around the carrier for translating the carrier in a proximal direction (P) for advancing the needle beyond a proximal end of the auto-injector, and a trigger button is used for releasing the control spring on actuation.