| 摘要 |
A non-reusable hypodermic syringe includes a body having a front end, a rear end and an inner wall extending from the front end to the rear end, a needle extending from the front end. A plunger assembly includes a rod member having a rearward end extending from the rear end of the body and a forward end within the body and a head portion integral with the forward end of the rod member. The head portion has an outwardly facing circumferential groove therearound. An O-ring is seated in and protrudes outwardly from the outwardly facing groove and engages the inner wall of the body. The body has an inwardly facing circumferential groove adjacent the front end of the body and positioned to receive the O-ring therein when the grooves confront each other, thereafter to resist movement of the rod member in the filling direction away from the front end of the body, thereby rendering the syringe non-reusable. A deflectable cap is affixed to the face of the head member or is seated in the front end of the body. The cap is deflectable as the grooves approach each other, so that a user can sense a change in the syringe action and realize that slight further movement of the rod member toward the front end wall achieve non-reusability.
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