| 摘要 |
<p>A hypodermic syringe having an automatically retractable needle assembly (15), releasably activated upon voiding the syringe of fluid material. The syringe includes a variable force spring (20), added mass (22) or a friction O-ring (23) to control the speed of the retracting needle (15) upon activation of the release clamps (14) by the plunger extention (13).</p> |
