Abstract: A plunger for a retracting needle syringe includes a hollow elongate body portion having a proximal end, a distal end, and a side wall therebetween defining a cavity. The distal end includes a distal wall having an inside surface and an outside surface. A stopper, at the distal end of the body portion, includes a peripheral portion performing a seal with the inside surface of a syringe barrel and at least one radial element extending from about a center of the outside surface of the distal wall to the peripheral portion. The distal end of the body portion includes at least one primary chamfer in the cavity at an intersection of the inside surface of the distal wall and the side wall. The chamfer is positioned under the at least one radial element for supporting the distal wall and the radial element when a hollow sleeve in the syringe barrel cuts through the end wall plunger. A secondary, smaller chamfer on each side of the primary chamfer is also provided.

Abstract: A single use syringe assembly includes a barrel having a chamber for retaining fluid, an open proximal end and a distal end including an elongate tip extending distally therefrom having a passageway therethrough in fluid communication with the chamber. A needle cannula having a lumen therethrough is connected to the elongate tip so that the lumen is in fluid communication with the passageway. An elongate needle shield having a longitudinal opening therein is hingedly connected to the barrel. A needle shield is capable of pivoting from an open position or a closed needle protecting position. The plunger including an elongate body portion and a stopper is slidably positioned in fluid-tight engagement with the inside surface of the barrel. Structure is provided for locking the plunger in the barrel by applying distally directed force to the plunger after fluid has been delivered from the chamber.

Abstract: A shieldable needle assembly of the present invention includes an elongate needle with a proximal and a distal end that has an outside surface and a hollow bore therethrough. The assembly has a hub fixedly attached at the proximal end of the needle for attaching the assembly to a fluid handling device so that the bore of the needle is in fluid communication with the fluid handling device. The assembly has a guard disposed for selective slidable movement on the needle between a proximal position wherein the distal end of the needle is exposed and a distal position wherein the distal end of the needle is substantially protected from inadvertent exposure. The guard has a passageway therethrough sized to form a substantially fluid tight seal about the outside surface of the needle.