| 摘要 |
<p>A syringe (10) comprises a barrel (11) containing an internal cylindrical body (12) containing a liquid (14) and communicating with a delivery needle (15). The needle (15) is covered before use by a removable sheath (16), and after the sheath (16) is removed, the needle (15) is concealed by a displaceable sleeve (20). In use the sleeve (20) is pressed against the skin by applying pressure while holding the barrel (11). The sleeve (20) is thereby retracted into the barrel (11) allowing the needle (15) to penetrate the skin. The movement of the sleeve (20) also activates a gas generator (17) which expels the liquid (14) from the needle (15). When delivery is complete and the syringe (10) is taken from the skin, a coil sprint (22) moves the sleeve (20) back to the starting position again concealing the needle (15). The coil spring (22) is torsionally biased before use and causes a rotational movement of the sleeve (20) relative to the barrel (11) when the sleeve (20) moves into and out of the barrel (11). This rotational movement engages a locking mechanism which prevents further movement of the sleeve (20) and thereby permanently conceals the needle (15).</p> |
