An injection device comprises a casing, a syringe carrier located within a proximal end of the casing and being movable along a longitudinal axis of the device between a stowed position and a needle insertion position, and a drive assembly located within a distal end of the casing and being movable by an insertion driver in order to move the syringe carrier and a loaded syringe from a stowed position to a needle insertion position. The device further comprises a first formation fixed relative to the casing and a second formation fixed relative to an insertion tube of the drive assembly, the first and second formations defining between them a plurality of stop positions for the insertion tube relative to the casing, spaced along the direction of said longitudinal axis, to prevent significant rearward movement of the insertion tube along said axis when a plunger of a firing cartridge is released from a reaction assembly of the cartridge.本發明提供了一種注射裝置係包含：一殼體；一注射器托架，係位於該殼體之近端內，藉以容納一注射器並且可於一裝載位置與一針頭插入位置之間在該注射裝置之一縱向軸上移動；以及一驅動組件，係位於該殼體之遠端內並透過一插入驅動器在該縱向軸上移動，藉以將該注射器托架及一裝載注射器從該裝載位置移動至該針頭插入位置。這種注射裝置還包含：一第一結構與一第二結構，其中該第一結構相對於該殼體固定，且該第二結構相對於該插入管固定，該第一結構與該第二結構之間限定了該插入管相對於該殼體之複數個止動位置，藉以在該作用力組件釋放該柱塞時防止該插入管沿該縱向軸向後移動。
