Patent attributes
An injection device comprises a pre-filled syringe and a safety mechanism for providing needle safety for an injection needle of the syringe. The syringe comprises a barrel containing the liquid and a stopper disposed within the barrel. The needle is attached to a distal end of the barrel. The safety mechanism comprises a substantially cylindrical housing adapted to contain the syringe, a plunger to expel the liquid through the injection needle, and an energizable biasing member arranged between the housing and the syringe. The energized biasing member is capable of biasing the syringe with respect to the housing in a proximal direction and a retaining mechanism for retaining the syringe with respect to the housing in a first retracted position in an advanced position and in a second retracted position.