| 摘要 |
The injection needle (14) is inserted through a central passage in the protective casing (20) to a position in which its point (16) produced by chamfering is outside the cannula tube. For reciprocal engagement between the injection needle and the protective casing with the needle point located outside the casing for withdrawal of the casing out of the cannula together with the injection needle, stop components are provided on the needle and casing for mutual engagement, i.e. a crossways positioned extension surface (19) on the needle and two elastically pliable hooks in the casing. The free ends of the hooks are directed towards the one or the other end of the protective casing and are formed with an extension surface inserting into a passage through the protective casing. The distance between the hook extension surfaces is at least as great as the distance between the injection needle extension surface and the point. |
