| 摘要 |
The syringe has an end piece (4) with flexible tabs (9) extending inward and terminated by lugs (10). A hollow mobile element (16) with nozzle (20) attached in a moderately firm manner at its end can slide between the tabs. It is stopped at the rear by lugs (10), and its cavity (23) features ridges (24). The piston (2) has an extension comprising several parts: a smooth wide segment (26) can engage the lugs (10), a segment (28) with ridges (29) can slide into the cavity (23). When the piston (2) reaches the end of its travel, it pushes and releases nozzle (20) from the mobile element (16) enabling a segment (30) fitted with barbs (31) to slide into the passage of nozzle (20). After the injection has been made, the segment (26) separates the lugs (10) and releases mobile element (16) to the rear. Ridges (29 and 24) and engagement of barbs (31) with nozzle (20) ensure that the mobile element-nozzle-holder assembly (16, 20, 19) and the needle are pulled back into the syringe by the piston. |
