Patent ID: 8313458

Claim:
A needle-retracted controlled safety syringe, comprising a syringe barrel, a needle carrier which carries a needle, a sleeve which covers said needle carrier and a plunger, wherein: said plunger comprises a barrel-like plunger comprising: a barrel comprising a front portion which is fitted over a sealing rubber pad; a needle retracted trigger; and a supporting member; wherein: a slotted hole is disposed at a wall of the front portion of said barrel; a bearing piece is disposed in said slotted hole; one end of said bearing piece is connected to a front side wall of said slotted hole; said bearing piece is deflected laterally towards an interior of said barrel such that said bearing piece is resettable in order to support said needle retracted trigger; said needle retracted trigger is disposed at a front end of a cavity of said barrel and is supported on said bearing piece which has been deflected laterally; said supporting member is disposed in said barrel, a front end of said supporting member supporting said bearing piece which has been deflected laterally, and a rear end of said supporting member comprises a base for sealing the opening at the rear end of said barrel; said barrel and said supporting member each comprising a snap-in structure respectively, which are releasably engaged cooperatively with one another; and said supporting member translates backwards under the action of a needle retraction force so that said bearing piece is returned to a position wherein said needle retracted trigger and said needle are retracted backwards to the interior of said barrel; said syringe barrel is made of one of glass and cycloolefin copolymers; and said needle carrier, said sleeve which covers said needle carrier and said needle retracted trigger are made of one of stainless steel, glass and cycloolefin copolymers, or are each coated with a layer of polytetrafluoroethylene by means of plating or dipping.