Sanofi
Drive mechanism and drug delivery device herewith

Abstract:

The present disclosure is generally directed to a drive mechanism for use in a drug delivery device having a cylindrical cartridge, i.e. a handheld injection device for selecting and dispensing a number of user variable doses of a medicament. The drive mechanism includes a base element, a toothed piston rod, which is guided within and movable relative to the base element, and a drive gear having a pinion, which is rotatably held in the base element and in meshed engagement with the toothed piston rod. The toothed piston rod includes multiple rigid rod pieces which are connected by hinges. The rigid rod pieces comprise a flat plate provided with a straight toothed rack.