PRESSURE RELIEVE MECHANISM FOR A MEDICAL DELIVERY DEVICE

摘要

The present invention relates to a pressure relief mechanism for a medicament delivery device, which delivery device comprises a medicament container (12), a threaded plunger rod (14) capable of acting on said container (12) for expelling a dose of medicament, a threaded nut (20) arranged to cooperate with said plunger rod (14), wherein said pressure relief mechanism comprises at least one alteration in the pitch (18) of the threads of the plunger rod around its circumference.