Patent ID: 6663593
Filing Date: 2003-12-16
Classification: A61M

Abstract:
A non-reusable syringe, comprisinga generally cylindrical hollow barrel adapted for mounting an injection needle thereon at a proximal end thereof; a plunger adapted for longitudinal displacement within said barrel, formed at its proximal end with a plurality of radially flexible claws which, in an unflexed configuration, are spaced from each other by a space of predefined radius; an elastomeric piston having an outer rim adapted to engage against an inner surface of said barrel, said piston being formed on a distal surface thereof with a central recess including an annular internal groove adapted, during a normal configuration of said piston, to receive and engage said claws; and a bolt having a head portion and a shank portion, said shank portion being dimensioned to fill said space of predefined radius between said claws, and said head portion being dimensioned radially larger, to keep said bolt seated between said claws during a first fluid-charging stroke of said syringe, whereby, during a fluid-injecting stroke of said plunger, fluid pressure expels said bolt from between said claws and said elastomeric piston deforms, causing said claws to flex radially inward and to lose engagement with said annular groove, said plunger thereby detaching from said piston and rendering a second charging stroke of said syringe impossible.