Patent ID: 7465289

Claim:
A syringe firing mechanism for a syringe held within a housing, the housing incorporating a drive spring acting on a drive member provided with a release trigger which, when released, enables the drive member to act on a plunger of the syringe under the bias of the drive spring, firstly to drive the body of the syringe forwardly to cause the needle portion of the syringe to move out of the housing and secondly to cause a dose to be ejected from the syringe, the housing also incorporating a return spring to provide a reverse bias on the syringe body to enable the needle portion of the syringe to be withdrawn into the housing after ejection of a dose, and a cover positioned over the rear of the housing, which moves in a first direction towards the syringe to actuate the release trigger or to provide access for actuation of the release trigger, and which moves subsequently in the reverse direction and actuates a release mechanism which will free the plunger from the drive member to allow the syringe to be withdrawn into the housing under the bias of the return spring.