Dose setting mechanism and injection device

Abstract

A dose setting mechanism (1) for a resettable drug delivery device is provided com-prising a dose setting member (3) and a drive member (4) for driving a piston rod in a distal direction during dose dispensing, wherein the drive member (4) comprises a proximal drive member (4‖) and a distal drive member (4'). Further, a first clutch is provided for releasably coupling the proximal drive member (4‖) and the distal drive member (4'). A spring means (7) biases the proximal drive member (4‖) and the distal drive member (4') in the coupled state during dose setting and dose dispensing. According to one aspect of the invention engaging means (3a, 4a) are provided associated to the proximal drive member (4‖) and to the dose setting member (3), wherein the engaging means (3a, 4a) are designed and arranged such that the proximal drive member (4‖) entrains the dose setting member (3) in the distal direction during dose setting but allows a relative axial movement of the proximal drive member (4‖) with respect to the dose setting member (3) in the proximal direction. Further, the invention refers to an injection device with such a dose setting mechanism.