Patent attributes
A plunger of a syringe characterized by a hook unit formed integrally at the front end of the stopper of thereof. The hook unit comprises a central rod and a push wing extended outwardly from a lateral wall of the central rod. The push wing can be attached to the central rod by a lateral force, which is urged during an insertion process, so that the hook unit will be inserted into a receptacle formed at the rear end of the needle hub in the axial direction. The receptacle has an entrance hole and a cavity lager then the hole, whereby the flexible push wing will be extended again after the unit is in the cavity, forming a locked configuration. As the plunger is pulled back, the needle mount will be pulled into the needle barrel accordingly, achieving a function of self destruction.
