摘要 |
An injection device (110) is described having a housing (112) that receives a syringe (114). The syringe is biased by a return spring (126) from an extended position in which the needle (118) extends from the housing through an exit aperture (128) to a retracted position in which it does not. A drive spring (130) acts via a drive to advance the syringe from its retracted position to its extended position and discharge its contents through the needle and a return spring, brought into play when the drive has reached a nominal return position, restores the syringe to its retracted position. A releasable locking mechanism retains the syringe in its retracted position. A sleeve (119) projects from the exit aperture and can be depressed to release the locking mechanism. A trigger (300) has a rest position, in which it engages the drive, retaining it in a position corresponding to the retracted position of the syringe, and a depressed position, in which it no longer causes the drive to be so retained. |