| 摘要 |
A syringe comprises 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 interrupting the cylindrical surface of its inner wall in the form of grooves (10, 11) or projecting (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. (Figs 1,14,17,20 not shown). The plunger (17) is a one-piece moulding, and is made in apparatus comprising a two-part moulding tool, each part (30) bearing an impression of a portion of the plunger (7) such that the two parts cooperate to make the whole plunger (7), each part (30) having a removable insert (36) bearing the impression for the locking means (17, 20) for the respective plunger portion. |
