Patent attributes
An auto-injector includes a chassis and a carrier subassembly. The carrier subassembly includes a carrier arranged inside a case, a drive spring, a plunger comprising a ramp member, the plunger configured to be pushed in a proximal direction by the drive spring, and a ramp attached to the carrier, wherein the ramp member on the plunger in an initial state is locked to the ramp on the carrier to form a ramped engagement to the carrier, the plunger prevented from rotating out of the ramped engagement depending on a relative longitudinal position of the carrier relative to the chassis, wherein the plunger is arranged to be released and to rotate out of the ramped engagement upon the carrier translating a pre-defined distance in a proximal direction relative to the chassis.