A drive mechanism for a delivery device (11), a driving member for driving the piston rod (13) (17) disengaged from the drive member (17) in a dose setting condition, dose delivery is movable in the driving direction in the state, a dose setting member movable (19, 35), in a dose-delivery state, the driving direction of movement of the dose setting member (19, 35), transmitted to the drive member (17) to engage with the drive member (17) as can be, the dose setting member and the (19, 35) setting the direction of the movement of the dose setting member (19, 35) places a load on the spring member (21) in a dose-setting state in a concatenated spring member in the dose setting member (19, 35) (21), the spring force of the spring member the load is applied (21), drives the dose setting member (19, 35) in a dose delivery state as to drive in the direction, and a spring member, the drive mechanism送達デバイス用の駆動機構(11)であって、ピストンロッド(13)を駆動するための駆動部材(17)と;用量設定状態において駆動部材(17)から係合解除され、用量送達状態において駆動方向に可動である、可動の用量設定部材(19、35)であって、用量送達状態において、用量設定部材(19、35)の駆動方向の動きが、駆動部材(17)に伝えられるように駆動部材(17)と係合する、用量設定部材(19、35)と;用量設定部材(19、35)の設定方向の動きが用量設定状態においてばね部材(21)に負荷をかけるように用量設定部材(19、35)に連結されたばね部材(21)であって、負荷がかけられたばね部材(21)のばね力は、用量送達状態において用量設定部材(19、35)を駆動方向に駆動する、ばね部材とを含む、駆動機構。
