Sanofi
Drive mechanism and injection device herewith

Abstract:

A drive mechanism suitable for an injection device includes a housing, a piston rod at least axially movable relative to the housing, and a drive member which is coupled to the housing via a first clutch such that a relative rotation of the drive member about an axis of rotation with respect to the housing is prevented during dose setting and is allowed during dose dispensing. The drive member engages the piston rod such that a rotation of the drive member causes an axial movement of the piston rod. Re-engagement of the first clutch causes rotation of the drive member with respect to the housing in a direction moving the piston rod in the proximal direction.