| 摘要 |
A disposable safety syringe includes a barrel body, a needle seat holding a needle in position, a plunger body, having an interior cavity, slidably mounted in the barrel body, and a needle retraction device including an end stopper, having a retraction ring, mounted in the plunger body, a compression spring mounted at the end stopper, and a retraction head integrally downwardly and integrally protruding from a bottom end of the needle seat to align with the retraction ring, wherein when the plunger body is kept moving towards the upper portion of the barrel body after the injection operation is completed, the retraction head is engaged with the retraction ring to couple the needle seat with the end stopper, such that the compression spring pushes the end stopper into the plunger body to retract the needle seat and the needle into the plunger body.
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