Patent ID: 6991618
Filing Date: 2006-01-31
Classification: A61M

Abstract:
1. A single use syringe assembly comprising: a barrel having an inside surface defining a chamber for retaining fluid, and open proximal end and a distal end having a passageway in communication with said chamber; a plunger rod assembly including an elongate body portion having a proximal end, a distal end, first and second adjoining portions, said first portion being distal of said second portion and having a smaller diameter than said second portion, a first shoulder separating said first and second portions, and a stop surface at the distal end of said first portion, and a stopper mounted to said elongate body portion proximate said distal end, said stopper being slidably positioned in substantially fluid tight engagement with said inside surface of said barrel, said elongate body portion extending outwardly from said open proximal end of said barrel; and a generally trough-shaped locking element positioned within said barrel, said locking element defining a channel, a distal end and a proximal end, said elongate body portion of said plunger rod assembly extending through said channel; one or more barbs extending from said locking element, said one or more barbs engaging said inside surface of said barrel for substantially preventing said locking element from moving proximally with respect to said barrel but allowing movement of said locking element towards said distal end; wherein said distal end of said locking element is engageable with said stop surface and said proximal end of said locking element is engageable with said first shoulder such that said locking element is movable towards said distal end of said barrel as said plunger rod assembly is advanced, and a spring member attached to said locking element and urging said one or more barbs towards said inside surface of said barrel.