Syringe assembly

Abstract

A syringe assembly includes a barrel having an open proximal end, a chamber for retaining fluid and a tip portion extending from a distal end of the barrel having a passageway therethrough communicating with the chamber. A needle cannula having a distal end extends outwardly from the tip portion and includes a lumen in fluid communication with the passageway. A needle shield assembly includes a resilient needle sheath having an open proximal end, a closed distal end, a sidewall defining a receptacle therein and an annular flange extending radially outwardly from the proximal end of the needle sheath. The needle sheath is positioned within an elongate rigid shield having an open proximal end, a distal end and a sidewall therebetween. Structure for holding the sheath within the shield includes a flange-receiving aperture in the needle shield sidewall adjacent to the open proximal end. The aperture includes a ledge on its proximal side for engaging the proximal side of the flange for holding the sheath in the shield. Structure is also provided for deflecting the annular flange causing more of the annular flange to project into the flange-receiving aperture than if the structure were not included. The needle shield assembly is positioned with the distal end of the cannula engaging the cannula sealing distal end of the sheath and the proximal end of the sheath removably engages the tip portion of the barrel to hold the shield assembly on the barrel while simutaneously sealing the lumen of the cannula.