The invention refers to an auto-injector (1) for administering a dose of a liquid medicament (M), comprising: -a tubular chassis (2) telescopable in a tubular case (12), -a carrier subassembly comprising a tubular carrier (7) slidably arranged relative to the chassis (2) inside the case (12), the carrier (7) adapted to contain a syringe (3) with a hollow injection needle (4), a drive spring (8) and a plunger (9) for forwarding load of the drive spring (8) to a stopper (6) of the syringe (3), wherein the syringe (3) is lockable for joint axial translation with the carrier (7), -a control spring (19) arranged around the carrier (7) for translating the carrier (7) in a proximal direction (P) for insertion of the needle (4) through the chassis (2) into an injection site, wherein the control spring (19) is arranged to bias the case (12) against the chassis (2) in a distal direction (D) so as to extend the chassis (2) out of a proximal end (P) of the case (12), wherein an insertion depth of the needle (4) is defined by the carrier (7) abutting the chassis (2) in a predefined position, wherein the case (12) is arranged to release or allow release of the control spring (19) for needle insertion on translation of the case (12) in the proximal direction (P) relative to the chassis (2) against the bias into an advanced position.本發明相關於一種自動注射器(1)，供給一液體藥劑(M)的劑量，包含：一管狀底座(2)，可伸縮於管狀外殼(12)中；一載體次組件(2)，包含：一管狀載體(7)，被設置以可相對於該外殼(12)內的該底座(2)滑動，該載體(7)適於容納一具有中空注射針(4)的針筒(3)；一驅動彈簧(8)以及一柱塞(9)，用以傳遞該驅動彈簧(8)的負載至該針筒(3)的一停止器(6)，其中該針筒(3)係可鎖定，用來與該載體(7)聯合軸向移位；一控制彈簧(19)，繞著該載體(7)設置，用來移位該載體(7)於一近端方向(P)而通過該底座(2)將該針(4)插進入一注射部位，其中控制彈簧(19)被設置以於一遠端方向(D)偏壓外殼(12)抵著該底座(2)，以便將該底座(2)延伸出該外殼(12)的一近端(P)，其中該針(4)的一插入深度藉由該載體(7)緊靠該底座(2)於一預先界定位置界定，其中該外殼(12)設置來釋放或容許釋放該控制彈簧(19)以在外殼(12)於近端方向(P)相對於底座(2)的移位抵抗該偏壓進入一前進位置時讓針插入。
