Patent attributes
An auto-injector for administering a dose of a liquid medicament includes a case and a carrier subassembly with a carrier slidably arranged inside the case. The carrier can contain a syringe with a hollow injection needle, a drive spring and a plunger for forwarding drive spring load to a syringe stopper. The syringe can jointly, axially translate with the carrier. The drive spring acts between the carrier and the plunger. In an initial state, the plunger is locked to the carrier by a ramped engagement to the carrier and is prevented from rotating out of this engagement depending on a longitudinal position of the carrier in the case. The plunger can be released for rotating out of the ramped engagement when the needle reaches nearly a predefined injection depth on translation of the carrier in the proximal direction for advancing the needle beyond a proximal end of the auto-injector.
