HYPODERMIC SAFETY SYRINGE WITH RETRACTING NEEDLE SYSTEM

摘要

A hypodermic safety syringe, includes a barrel (1a) having an open end, a cone shaped end and an interior surface. A hollow needle and carriage assembly is temporarily attached and is restrained by four catches extending from the interior tapered surface. A plunger assembly (2a-2f) is reciprocally received into the barrel and is in air-tight engagement with the interior surface of the barrel. Thus, an interior chamber is formed in the barrel whereby liquids are retrieved and emitted through the hollow needle. A cavity within the plunger contains a spring (3c) and retraction guide (3a) assembly with a mating member corresponding to mating members extending from the needle carriage (4b). As the mating members contact and become captured the needle and carriage assembly is released by the approaching plunger assembly. At the end of the injection stroke small spherical bearings (2b), in locking contact with the retraction guide (3a), are caused to move outward and into a radially concave interior surface releasing the retraction guide. Thus rendering the syringe safe for handling and transport to disposal.