Drive mechanism for a drug delivery device and drug delivery deviceThe drive mechanism comprises a piston rod (7), a dose member (12) with a thread engaging a corresponding thread of the body (1) to allow a helical movement of the dose member with respect to the body, a drive sleeve (11) rotationally coupled to the dose member, and stop means (14, 16) provided to restrict or inhibit a movement of the drive sleeve in the proximal direction and in the distal direction with respect to the body, the drive sleeve and the piston rod being unidirectionally coupled.
