| 摘要 |
A single-use syringe (1) is provided. The plunger (14) is rod-like and made with a plurality of cylindrical ratchet teeth (28). A locking spring clip (6) made from a resilient material is dangled on said ratchet portion of the plunger, and the location of the locking spring clip determines the maximum dosage which can be administered by the syringe. In use, a first withdrawal of the plunger with respect to the barrel (8) allows medication to be drawn into the cavity of the barrel since the camming tooth (21) of the locking spring clip glides by radial flexing over the surface of the ratchet teeth and, yet, the locking spring is maintained in relative position along the barrel by outwardly directed contact points (18) embedded into the interior sidewall (17) of the barrel. During administration of the medication, the locking spring clip moves along with the plunger since the interiorly directed camming tooth cooperates with the base of a ratchet tooth and is carried therealong. A second reciprocation is blocked, once the locking spring clip has been moved to its full distal position, carried there by the ratchet tooth pushing against the camming tooth of the locking spring.
|
