| 摘要 |
<p>An improved safety syringe comprises a hollow barrel (1), a push rod (2), a rubber plug (3) and a needle hub (4). A locking ring (7) under the needle hub movably matches the inner wall of the barrel. The front end of the push rod is formed with a conical platform (211). Elastic supporting claws (6) at the lower end of the needle hub, clamp into grooves set in the inner wall of the barrel. The outer wall of the locking ring presses against the elastic supporting claws. At least two flanges (612) set at the lower end of the needle hub match with shoulders (613) on the inner wall of the barrel. An inner hole of the locking ring is provided with an elastic detent (8) that can be clamped with the conical platform. After injecting, the conical platform in the front end of the push rod is clamped with the elastic detent in the locking ring, and the locking ring slides downward by pulling the push rod down to make the needle hub separate from the inner wall of the barrel. By using the syringe with the above structure, the needle hub won't rush out of the barrel under the pushing force after injecting because the flanges set on the needle hub match with the shoulders on the wall of the barrel, and there will be less injection liquid remained in the barrel after injecting.</p> |
