Syringe having a hinged needle shield

Abstract

A syringe assembly includes a syringe barrel having an elongate body, a tip on its distal end surrounded by a barrel collar. A needle assembly includes a needle cannula attached to a hub having a cavity in its open proximal end. The hub is attached to the barrel with the barrel tip in the hub cavity. A plunger having a stopper positioned in fluid tight engagement on the inside of the barrel. A collar is rotatably connected to the outside surface of the barrel collar. An elongate needle shield is hingedly connected to the collar. The needle shield includes two side walls defining a longitudinal opening and a recess. A needle shield is capable of pivoting about the collar from an open position to a closed position wherein the distal end of the needle cannula is in the recess of the needle shield. Structure is provided to lock the needle shield to the collar and to trap the needle cannula in the needle shield when the needle shield is in the closed position. Structure is provided to prevent over-rotation of the needle shield past the needle protecting position and to guide a needle cannula into the recess of the needle shield. An over-center hinge facilitates moving the needle shield to the closed position.