SINGLE USE SAFETY SYRINGE Russian patent published in 2004 - IPC

FIELD: medical engineering. SUBSTANCE: device has a cap for closing needle sliding along syringe cylinder. The cap is hold in its rest state by means of holding tongues catching the cap at its posterior rim. Posterior flange of plunger rod moves the holding tongues radially apart to make the cap closing the needle free at the final stage of plunger movement in making injection. The cap moves forward along the axis by means of spring to a projecting safety position in which it completely closes the needle and becomes fixed by means of ring for clamping the cap manufactured on the frontal end of the syringe. The ring for clamping the cap is manufactured for this purpose as one having peripheral electrode tongues engageable with corresponding holding teeth on the internal part of the cap for closing the needle that hinders any backward movement along the axis of the cap for closing the needle. The ring for clamping the cap has restricting rest member engageable with the internal projection of the cap for closing the needle and hinders in performing any additional forward movement along the cap axis. EFFECT: automatic arrest of syringe plunger rod. 13 cl, 8 dwg