Patent attributes
An auto-injector for administering a dose of a liquid medicament has a tubular chassis telescopable in a tubular case, a carrier subassembly comprising a tubular carrier slidably arranged relative to the chassis inside the case, where the carrier adapted to contain a syringe with a hollow injection needle. The injector 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. There is also a trigger button arranged distally or laterally in or on the case, a control spring arranged around the carrier, and a needle extension control mechanism for coupling a proximal end of the control spring to either the carrier for advancing it for needle extension or to the chassis for needle retraction depending on the relative axial position of the carrier and the chassis.
