A lead screw, a lead screw nut (7) and a drive member (8) are aligned with an axis defining an axial direction and an opposite axial direction. A coupling between the lead screw and the lead screw nut allows a helical movement of the lead screw with respect to the lead screw nut at least in the axial direction. The lead screw is coupled with the drive member, the coupling generating a helical movement of the lead screw with respect to the drive member when the drive member is moved in the axial direction with respect to the lead screw. A dispense stop feature (19) of the lead screw nut and a dispense stop feature (20) of the drive member prevent the generation of the helical movement of the lead screw when a specified end position of the drive member is approached.
