Abstract: A single use disposable medical syringe is constructed and operated in a manner which prevents transmission of infection by the syringe after its use for inoculation. The syringe is marketed in a sterile package ready for use. The syringe needle is then covered by a shield. The syringe plunger assembly is then releasably locked to the barrel of the syringe. Following opening of the sterile package and removal of the needle shield, the plunger assembly is operated to fill the syringe barrel with medication and to inject the patient. Following injection, a piston head housing is unlocked from the syringe barrel and the plunger assembly is retracted toward the rear of the barrel and becomes automatically locked in this position with the piston head housing. The needle is disposed within the barrel rearwardly of a safety shield on the forward end of the barrel containing a safety membrane.

Abstract: To replace the customary short flexible tube with attached needle at one end and larger tube connector at its other end, a packaged sterile blood donor assembly is provided. The assembly includes a rigid body having a bore and being equipped at its forward end with a needle and at its rear end with a tube connector having a safety reversible cap. An exterior sleeve on the rigid body is lockable in two positions thereon with the needle in an exposed use position and with the needle retracted and locked in a safety non-use position rearwardly of a safety shield and elastic membrane on the forward end of the exterior sleeve. A discardable needle shield is also provided on the assembly.

Abstract: A sterile barrel and piston assembly with attached aspirating needle is delivered ready for use. Following removal of a needle shield and a reversible safety cap from the rear of the piston, the needle is inserted in a vein and evacuated blood sample tube is inserted in the piston to be penetrated by the rear end of the needle. Following removal of the needle from the vein and removal of the evacuated tube now containing a blood sample, the piston is turned in one direction relative to the barrel of the device to release a first lock between the barrel and piston, followed by retraction of the piston and turning of the piston in the same direction to activate a second lock between the barrel and piston. The safety cap is reversed and re-applied to the rear of the piston where it becomes permanently locked in place. The needle is now safely enclosed within the barrel rearwardly of a safety shield and membrane on the front of the barrel.