A medication injecting apparatus has a cartridge housing and a drive housingthat isthreadedly connected to the cartridge housing for axial displacement relativeto oneanother. The drive housing has a helical-shaped passage and a flexible drivemember isslidingly disposed within the helical-shaped passage and extends axiallyoutwardlytherefrom toward the cartridge housing. The flexible drive member is movablein theaxial direction relative to the drive housing during dose setting and isaxially fixedrelative to the drive housing during injecting. A clutch has an engagedposition and adisengaged position. The flexible drive member is axially fixed relative tothe drivehousing when the clutch is in the engaged position and the flexible drivemember ismovable relative to the drive housing when the clutch is in the disengagedposition.
