Patent ID: 6497679
Filing Date: 2002-12-24
Classification: A61M

Abstract:
A safety hypodermic syringe comprising:a barrel, said barrel comprising an inside wall defining a receiving chamber, said inside wall comprising a rear section, a front section of diameter relatively smaller than the rear section of said barrel, a step connected between the rear section and front section of the inside wall of said barrel, a stop means suspended within the front section of the inside wall of said barrel, and at least two connecting ribs radially connected between the front section of the inside wall of said barrel and said stop means; and a needle cannula holder, said needle cannula comprising a front extension hub inserted through said stop means of said barrel and holding a needle cannula, a rear section fitting the inner diameter of the rear section of the inside wall of said barrel, a front section axially connected between the rear section of said needle cannula holder and said front extension hub and fitting the inner diameter of the front section of the inside wall of said barrel, a step formed between the front section and the rear section of said needle cannula holder and adapted for stopping at the step of said barrel, a shoulder formed between said front extension hub and the front section of said needle cannula holder and stopped at a rear side of said stop means of said barrel, and locating means protruded from the periphery of said front extension hub and stopped at a front side of said stop means of said barrel; when said needle cannula holder is pushed forwards after the service of the safety hypodermic syringe, said shoulder is forced against said connecting ribs to break said connecting ribs and to separate said stop means from the inside wall of said barrel, for enabling said needle cannula holder and said needle cannula to be further pulled backwards into the inside of said barrel.