| abstract |
A retractable syringe, plunger and releasable needle release assembly are provided. Retractable syringes typically have a glass tube and are pre-filled with fluid content before use. The releasable needle retention system includes a retractable needle, a needle seal, a retention member, and an ejector member operable to release the retractable needle from the retention member. The holding member has a mating surface for attaching to a complementary mating surface of the inner wall of the syringe barrel. The plunger includes a plunger sheath, a plunger rod that is breachably connected to the control member, a spring, and a single body plunger seal that can engage with a retractable needle. The plunger rod, plunger sheath and control member cooperate to maintain the biasing member in an initially compressed state. After delivery of the flowable contents of the syringe, the plunger squeezes the ejector member to release the retractable needle from the retaining member. The restoration of the spring at the end of the plunger lowering facilitates the retracting of the retractable needle upon engagement with the single body plunger seal. The double locking system prevents reuse of the syringe after needle retraction. |