| 摘要 |
A skin pricker has a housing (1) for a lancet (5) which, when released from a rearward cocked position, is propelled forwards by a spring momentarily to project its tip (3). During the forward motion a peg (12) within the housing (1) passes along a slot (10) in the lancet and, just before the tip (3) projects, snaps through a neck (11) at the rear end of the slot. If the lancet (5) is then pushed back, the peg (12) cannot re-enter the slot (10): instead it wedges the lancet sideways and, before it can be re-cocked, traps the lancet behind an abutment (13) ensuring that the tip (3) cannot be re-exposed. There can also be an arrangement (18, 21) whereby the lancet (5) cannot be prematurely pulled forwards by its cap (4) for the tip (3) and thus allow the peg (12) to escape the slot (10) before the pricker has been cocked and fired. |
