| 摘要 |
In the present invention, there is disclosed a syringe comprising a barrel (1) having a plunger (7) in slidable and sealing engagement therewith. In order to provide an autodestruct system, so that the syringe can be used once only, being rendered disabled after one normal use, the barrel (1) has means (10, 11; 29), interrupting the cylindrical surface of its inner wall in the form of grooves (10, 11) or a projection (29), and the plunger (7) has a locking means (17, 20) which operates on engagement with a groove (10, 11) or projection (29) on withdrawal of the plunger (7) to prevent further withdrawal movement. The locking means (17, 20) is provided on the head (14) of the plunger (7) adjacent an elastomeric sealing cap (15), is separated from a packing wherein its structure is such that the barrel is made as a stamping from one piece and the piston (7) along with the locking means (17, 20) is also made as a stamping of one piece. The locking means may comprise a pair of flukes (17) or a cross-shaped disc (20). |
