Reuse prevention injection device

Abstract

A disposable injection device may include a syringe barrel having a cylinder-shaped internal structure; a plunger rod which is coupled to the syringe barrel and movably disposed to make a sliding reciprocating motion to inject a medicine contained inside; and an adaptor which is coupled to an upper end portion of the syringe barrel to prevent separation of the plunger rod coupled to the syringe barrel, wherein when the plunger rod moves toward a syringe needle coupled to a lower end of the syringe barrel, a locking flange protruding in a radial direction of the plunger rod is inserted into a flange locking hole passing through the adaptor, and subsequently when the plunger rod is pulled in a rearward direction, the locking flange is fit into the flange locking hole to restrain movements in the rearward direction, thereby preventing syringe reuse.

Dependencies are inferred from the claim text.