Patent ID: 6468250
Filing Date: 2002-10-22
Classification: A61M,Y10S

Abstract:
A dual-chamber safety hypodermic syringe comprising:a needle assembly, said needle assembly comprising a needle hub and a needle cannula mounted in said needle hub, said needle hub is attached to a neck and an inlet on said neck is in communication with said needle cannula, and a handle extends from a peripheral surface of said needle hub; and a barrel, said barrel comprising a front side, a rear side, a medicine chamber and a needle chamber respectively extended in an axial direction, an outlet in the front side of said barrel, said needle chamber having a front open side connected to said outlet and a rear open side extended through the rear side of said barrel, said medicine chamber having a closed front side and a rear open side extended to through the rear side of said barrel, a guide hole communicated between said medicine chamber and said needle chamber, a longitudinal sliding slot disposed in parallel to and in communication with said needle chamber, and a front retaining hole extended sideways from a front end of said longitudinal sliding slot; wherein said needle assembly is slidably mounted in said needle chamber such that when said handle is moved forwards along said longitudinal sliding slot and engaged into said front retaining hole, said needle assembly is locked in an extended position to hold said needle cannula outside said barrel and to keep said inlet in communication with said guide hole for enabling a liquid medicine or blood to pass through said medicine chamber, said guide hole, said inlet and said needle cannula; and wherein said barrel further comprises a plug sealed to the rear open side of said needle chamber, and a spring device connected to between said plug and the needle hub of said needle assembly.