IMPROVED INJECTION DEVICE

An injection device comprising an outer housing configured to receive a syringe, the syringe having a barrel for containing medicament, a stopper that is axially moveable in the barrel, and a needle in fluid communication with the barrel. A plunger rod is axially moveable within the outer housing and configured for axially moving the stopper of the syringe when received in the outer housing. A needle shield is axially moveable relative to the outer housing between a needle covering position and a needle exposing position to selectively provide a needle enclosure, the needle exposing position being axially rearward of the needle covering position. A biasing means for biasing the needle shield axially forwardly toward the needle covering position is provided. A locking member is axially moveable in the outer housing from a first axial position to a second axial position in response to forward axial movement of the plunger rod. A locking sleeve is axially movable relative to the outer housing between a non-locking position and a locking position, the locking position being axially rearward of the non-locking position, in which axial movement of the locking sleeve is selectively limited by the locking member when in the second axial position. In a first configuration the needle shield is in the needle covering position and the locking sleeve is in the non-locking position so that at least a portion of the needle shield is axially slideable within the locking sleeve to permit rearward axial movement of the needle shield from the needle covering position to the needle exposing position. In a subsequent configuration the needle shield is in the needle covering position and the locking sleeve is in the locking position so that the needle shield is prevented from moving axially rearwardly by interference with the locking sleeve. La présente invention concerne un dispositif d'injection qui comprend un boîtier externe configuré pour recevoir une seringue, la seringue ayant un cylindre destiné à contenir un médicament, un bouchon qui est axialement mobile dans le cylindre, et une aiguille en communication fluidique avec le cylindre. Une tige de piston est axialement mobile à l'intérieur du boîtier externe et configurée pour déplacer axialement le bouchon de la seringue lorsqu'elle est reçue dans le boîtier externe. Une protection d'aiguille est axialement mobile par rapport au boîtier externe entre une position de recouvrement d'aiguille et une position d'exposition d