INJECTOR DEVICE

An injector device comprising an elongate housing having a proximal end and a distal end, and configured to receive a container of medicament, a needle sleeve mounted within the housing and moveable between an extended position in which the needle sleeve at least partially extends from the distal end of the housing, and a retracted position in which the needle sleeve is received further within thehousing than in the extended position;, a piston rod moveable longitudinally within the housing, a piston spring configured to bias the piston rod towards a distal end of the housing to engage a container of medicament when received within the housing, and a release mechanism configured to control actuation of the piston rod. The release mechanism comprises a locking arm moveable between a lockedposition in which the locking arm is in cooperating engagement with the piston rod and prevents movement of the piston rod, and a release position in which the locking arm is out of engagement with the piston rod so that the