FOLDED PLUNGER AUTO RETRACTABLE SYRINGE FOR SINGLE USE

摘要

The present subject matter relates to an auto retractable safety syringe (100) for single use which includes a needle carrier assembly (108) and a folded plunger assembly (200) respectively for inserting in an outermost barrel (110). The folded plunger assembly (200) is provided with an inner plunger barrel (102), an outer plunger barrel (104) and a plunger plug (106). The inner plunger barrel (102) is provided with at least one oppositely positioned circumferential C-groove (122) on outer surface at its proximal end P, a pair of oppositely positioned finger locks (118 and 120) on either end to get engaged with an outer plunger barrel (104), and a piston seal holder (114) structured at the proximal end P for holding a piston seal (116). The outer plunger barrel (104) includes at least one pair of oppositely positioned finger locks (156 and 158) on both ends and a second piston seal holder (124) at proximal end P for holding another piston seal (126). The folded plunger assembly is also provided with the plunger plug (106) which is designed with at least one uniform circumferential groove (136) wherein the plunger plug (106) is centrally designed with a longitudinally furrowed knob (140) at its proximal end P. The present subject matter also discusses about the needle carrier assembly (108) for housing in the outermost barrel (110) in which the needle carrier assembly (108) includes a seat and internal locking arrangement (148) provided in a central axial passage opening designed in a cavity (146) at the distal end D to snap lock the furrowed knob (140) present in the plunger plug (106), a needle (152) provided with a needle cover (154) at the proximal end P of the needle carrier assembly (108), and the elastic O-rings (132) to support and hold the needle carrier assembly 108 inside the outermost barrel (110), and to dislodge the assembly on completion of injection. The present invention further explains that the outermost barrel (110) designed to receive the folded plunger assembly (200) alter getting in the needle carrier assembly (108), wherein the outermost barrel (110) is provided with a finger rest (128), a uniform obtuse-angled L-shaped inner circumferential conical groove (130) and a conical jacket opening (134) at the proximal end of the outermost barrel (110).