Prefilled retractable syringe, plunger and needle assembly therefor

• Main Authors: JOSEPH KAAL, RICHARD SOKOLOV, HUW WALLIS, STEVE CHI TRUONG, CRAIG THORLEY, CHRISTOPHER RAFFERTY, ERNESTO HUESO
• Format: Patent
• Language: English
• Published: 08.01.2009
• Subjects: DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROMTHE BODY; HUMAN NECESSITIES; HYGIENE; MEDICAL OR VETERINARY SCIENCE

A retractable syringe, plunger and releasable needle assembly including a retractable needle, a needle seal, a retaining member and an ejector member. The retaining member has a mating surface for mounting to a complementary mating surface of an interior wall of a syringe barrel. The plunger comprises a plunger outer, a plunger rod frangibly connected to a controlling member, a spring and a unitary plunger seal capable of engaging the retractable needle, wherein the plunger rod, plunger outer and the controlling member co-operate to releasably maintain the spring in an initially compressed state. After delivery of fluid contents of the syringe, the plunger forces the ejector member to release the retractable needle from the retaining member. Decompression of the spring at the end of depression of the plunger facilitates retraction of the retractable needle when engaged with the unitary plunger seal.