DRIVE MECHANISM FOR USE IN A DRUG DELIVERY DEVICE, DRUG DELIVERY DEVICE AND METHOD OF MANUFACTURING OR ASSEMBLAGE OF THE DRUG DELIVERY DEVICE

摘要

A drive mechanism for use in a drug delivery device comprising: a housing; a drive member movable longitudinally and non-rotatable with respect to the housing; a piston rod that is non-rotatable with respect to the housing and having at least one set of teeth, a rotating means releasably engaged with the piston rod and engaged to the drive member and engaged to the housing I wherein the rotating means is selected from the group of (I) to (ii), (i) a gear the axle of which is engaged with the set of teeth of the ' piston rod, (ii) a pulley comprising a belt and a wheel the axle of which is engaged with the set of teeth of the piston rod; characterized in that, a) when the drive member moves proximally with respect to the housing the rotating means moves proximally with respect to the piston rod; b) when the drive member moves distally the rotating means moves distally displacing the piston rod towards the distal end of the device.