Abstract: A safety syringe is disclosed. The safety syringe has a retractable needle facility incorporated therein, the syringe comprising a barrel and plunger and needle assembly. The needle is caused to retract into the barrel of the syringe upon completion of injection once it has been used, by means of engagement between the needle assembly and the end of the plunger. Locking means preferably in the form of a locking bush is provided in the body of the syringe to engage the plunger once it is retracted after use, so that the syringe is rendered incapable of being used further.

Abstract: Means to control the retraction of an auto-retractable safety syringe to minimise splashback or splatter is disclosed. The end of a hollow plunger (11) is covered by a sealing member (14) that, upon retraction, is dislodged so that the needle assembly and seal enters the hollow plunger. Three methods by which the auto-retraction is controlled are disclosed. Firstly there is provided a taper within the inside of the hollow plunger which creates varying resistance of movement to the sealing member. Secondly there is provided a bleed hole (15) at the upper end of the plunger, whereby the air is allowed to escape. Thirdly, there is provided on or more grooves (16) in the periphery of the plunger seal so that air is allowed to be released, thereby reducing the pressure in the plunger and hence the possibility of splashback.

Abstract: A safety syringe having a retractable exchange needle is disclosed. The safety syringe (11) has a retractable needle (14) incorporated therein. The syringe barrel (12) has a plunger (13) slideably located therein, with piston means 26 located towards the end of the plunger remote from the end of the barrel from which the plunger extends. The needle (14) has a needle hub (15) integral with the needle. The plunger has engagement means in the form of a clip (22) having barbed means (24) associated therewith and located on its end to engage with the needle hub in order to retract the needle from an in use position into the syringe barrel after the syringe has been used.

Abstract: A retractable syringe (11) is disclosed wherein the needle (14) is located initially in a first storage position enclosed within the syringe body (12). In a second in-use position, the needle extends from the body of the syringe. To move needle from first to second position, the plunger (13) connects the needle boss (15) with the syringe body ens (16). The plunger is then disengaged from the needle boss enable the plunger to be withdrawn and thereby take in fluid into the syringe. Upon completion of injection the plunger engages with the needle boss enabling the plunger to be withdrawn, the needle remaining attached. Engaging the plunger to the needle boss requires the same amount of force as to perform the injection. Lateral forces act to engage the needle boss and the end of the plunger, for example by utilising a cam mechanism in the form of a finger lock device (26).