Patent ID: 6994692

Claim:
A drive mechanism for an injection device in which a piston is successively moved in relation to a first end of a medicament cartridge containing a medicament selectively to drive a bung closing the first end of the medicament cartridge into the medicament cartridge to expel medicament through a delivery member located at a second end of the medicament cartridge, the drive mechanism comprising: a piston member, a semi-rigid belt connected at the first end to the piston member, a belt drive means to drive the semi-rigid belt and a dose setting mechanism to control the driving of the semi-rigid belt, wherein the belt drive means comprises a first cable means connected at the first end to a rotatable spool and at the second end to a fixed point on the housing, guide means within which the semi-rigid belt is adapted to be guided, a stopper movably located within the guide means, such that rotation of the spool causes the first cable means to move the stopper within the guide means to drive the semi-rigid belt.