Patent ID: 6053894
Filing Date: 2000-04-25
Classification: A61M

Abstract:
A hypodermic syringe comprised of:a) a hollow cylindrical body portion, one end terminating in an outlet tube of a diameter smaller than the diameter of the cylindrical body portion;b) a hollow hypodermic needle communicating with the outlet tube of said body portion;c) a primary piston comprising an elastomeric material disposed within and adapted for reciprocal movement within said cylindrical body;d) shaft means attached to said primary piston and extending outwardly of the end of said body portion opposite the outlet tube and operative to impart reciprocating movement to said primary piston to ward and away from the outlet tube of said body portion; ande) an auxiliary piston carried by and positioned within said primary piston, said auxiliary piston adapted to puncture the elastomeric material of said primary piston and enter the interior of the outlet tube of said body portion after said primary piston contacts the outlet tube.