US Patent 8376998 Automatic injection device

An automatic injection device including a housing element, at least one resilient element arranged to be located within the housing element, a syringe including at least one syringe piston, a needle guard adapted for selectable positioning with respect to the housing element and a selectable driving element adapted, when actuated, to be driven by the at least one resilient element for initially displacing the syringe relative to the housing element from a non-penetration position to a penetration position and thereafter displacing the at least one syringe piston in the syringe to effect drug delivery and displacing the needle guard into a needle guarding position.