DISPOSABLE SYRINGE HAVING A RETRACTABLE NEEDLE

摘要

A disposable syringe having a retractable needle and a spring (17) for automatically withdrawing the plunger (1) from the barrel after injection, wherein plunger-locking projections (19) prevent the plunger from being reinserted into the sleeve. The projections pierce the plunger automatically when excessive force is exerted thereon, whereby the plunger (1) is damaged and the syringe is rendered useless.