The present invention is generally a method of assembling a drive spring (90), particularly to a drug delivery device, wherein the component (60a) to which the drive spring (90) is attached is rotated in a first direction and then the component ( It is directed to a method comprising the steps of rotating 60a) in the opposite direction and then attaching rotation stops (60b, 62). Furthermore, the present invention is directed to a drug delivery device for selecting and dispensing several user variable doses of medication, including a pre-charged drive spring (90).本発明は、一般に、駆動ばね（９０）を特に薬物送達デバイスに組み付ける方法であって、駆動ばね（９０）が取り付けられる構成部材（６０ａ）を第１の方向へ回転させ、次に構成部材（６０ａ）を反対方向へ回転させ、次に回転止め具（６０ｂ、６２）を取り付ける工程を含む方法を対象とする。さらに、本発明は、プレチャージ（ｐｒｅ－ｃｈａｒｇｅ）された駆動ばね（９０）を含む、薬剤のいくつかのユーザ可変用量を選択し投薬するための薬物送達デバイスを対象とする。
