SYRINGE HAVING A SPRING ACTION PLUNGER ROD

摘要

A syringe assembly (10) including a syringe barrel (12) defining a chamber (20) having a stopper (22) therein is disclosed. The syringe assembly includes a plunger rod (30) associated with the stopper, the plunger rod includes an outer sleeve (32) having a distal end (34) interconnected to the stopper and a sidewall portion (38) defining an opening (36) therein. The plunder rod also includes an inner sleeve (40) disposed within the outer sleeve including a longitudinally extending track (42) in alignment with the opening in the outer sleeve. The inner sleeve is adapted for telescopic movement with respect to the outer sleeve. The plunger rod also includes a spring (44) mounted in association with the inner sleeve. The syringe assembly further includes a holding mechanism (46) associated with the plunger rod and configured for cooperation with the inner and outer sleeves. Relative movement between the inner and outer sleeves causes the plunger rod to transition from a collapsed position to an extended position.