| 摘要 |
A skin pricker for blood sampling has a barrel (1) housing a lancet (2) which can be pushed back against a spring to a primed condition, by an elongate cap (4) over its needle tip there to be held by a trigger. The cap (4) is removed by twist and pull action. The lancet body (5, 6) has integrally formed spring arms (8, 18) extending rearwardly and alongside, and when the lancet (2) is fired these are momentarily flexed inwardly as their tips (9, 19) snap past abutments (11) within the barrel (1). These act as ratchets, providing a first defence against re-priming of the pricker. If that first defence is overcome by a substantial rearward force on the lancet, the spring arms rearward pointing V's which wedge between the abutments (11) and the lancet body (6). The cap (4) may have a weakness (20, 21) leaving it rigid enough for the initial priming but which causes it to buckle if used to try to overcome the ratchet. |
