Patent ID: 8920383

Claim:
A mechanism for preventing setting of a dose which exceeds the amount of a medicament in a reservoir in an injection device, wherein a dose is set by rotating a dose setting member of a dose setting mechanism, the mechanism comprising: a piston rod having a threaded outer surface, wherein the piston rod rotates and translates axially forward during expelling of medication from the reservoir; a limiter that prevents the setting of a dose which exceeds the amount of medication in a reservoir in the device, the limiter defining a passage for the piston rod; a driver defining a passage for the limiter, the driver being coupled to the dose setting member such that rotation of the dose setting member during dose setting causes the driver to rotate; and wherein the limiter is coupled to the driver and the piston rod such that relative rotation between the driver and the piston rod during dose setting causes the limiter to move towards a stopping position.