An assembly for a drug delivery device (1) is described, the assembly adapted to eject a drug from the cartridge (4) during a dose delivery operation of the assembly and a cartridge (4) containing multiple doses of drug. And a disposed piston rod (9), the piston rod (9) including a thread (9a). The assembly further includes a nut member (13) that is adapted and arranged to be rotated relative to the piston rod (9) about an axis of rotation (7) during a dose setting operation of the assembly. The nut member (13) is thereby moved from the start position to the final position relative to the piston rod (9) by mechanical cooperation of the nut member (13) with the thread (9a). 9) is displaced in the axial direction along. The assembly further includes a final dose stop mechanism adapted and arranged to prevent a user from setting a dose of drug in excess of the remaining drug amount in the cartridge (4), the final dose stop mechanism comprising a piston At least one first interaction member (16) and at least one second interaction member (17) provided by the rod (9) and at least one first interaction member provided by the nut member (13). A stop member (18) and at least one second stop member (19). The interaction member (16, 17) and the stop member (18, 19) include a nut member (13) and a piston rod (9). ) In a final position relative to each other, thereby providing a nut member (1 for setting the dose of the drug) ) And further relative movement between the piston rod (9) is prevented. In addition, a drug delivery device (1) is described.薬物送達デバイス（１）用のアセンブリが述べられており、このアセンブリは、複数用量の薬物を含むカートリッジ（４）と、アセンブリの用量送達操作中にカートリッジ（４）から薬物を排出するように適応および配置されたピストンロッド（９）とを含み、ピストンロッド（９）は、ねじ山（９ａ）を含む。アセンブリは、ナット部材（１３）をさらに含み、ナット部材（１３）は、アセンブリの用量設定操作中に回転軸（７）の周りでピストンロッド（９）に対して回転されるように適応および配置され、ナット部材（１３）は、それにより、ねじ山（９ａ）とのナット部材（１３）の機械的協働により、ピストンロッド（９）に対して開始位置から最終位置に向けてピストンロッド（９）に沿って軸方向に変位される。アセンブリはさらに、カートリッジ（４）内の残りの薬物量を超える薬物の用量を使用者が設定するのを防止するように適応および配置された最終用量ストップ機構を含み、最終用量ストップ機構は、ピストンロッド（９）によって提供される
