Patent ID: 7090657

Claim:
An auto-disable safety syringe, comprising: a needle; a needle seat connected to said needle; a seal; a plunger; a piston connected to one end of said plunger; a barrel, said plunger and said piston being capable of fitting and reciprocating inside said barrel, said barrel being formed at a bottom end thereof with a finger grip, a needle seat chamber being formed in front of a large top cover provided at a top end of said barrel, a small top cover formed at a top end of said needle seat chamber being provided with a splined hole, said splined hole being provided with plural protruding teeth on an inner wall thereof, and grooves of said splined hole being formed between adjacent protruding teeth respectively; a plunger positioning plate capable of fitting over said finger grip of said barrel; said needle seat being formed with a conical fitting and a ring block at a front end and a rear end thereof respectively, said needle seat being formed on an outer wall thereof with splined teeth capable of passing through said grooves, and a neck for embedding said seal being formed between said splined teeth and said ring block; and a locking groove being provided at a top end of an inner cavity of said ring block, said inner cavity being formed with spiral grooves in an inner wall thereof, a connecting head of said plunger being formed at a top end thereof with a locking head which forms a locking mechanism together with said locking groove, and said connecting head being provided on a side wall thereof with protrusions for engaging with said spiral grooves respectively.