US Patent 7112187 Injecting device

An injection device having an elongated body, including a container with medicament, elements for connecting a needle to the container, actuating elements capable of injecting a dose of medicament upon activation, activating elements capable of activating the actuating elements, a needle shield arranged to the body and slidable between an extended and a retracted position in relation to the body. The needle shield is designed and arranged such that, upon penetration of the needle into a patient, when moved to its retracted position, acts on the activating elements, which in turn activates the actuating elements and injects a dose.