| 摘要 |
A syringe (10) has a plunger (20), a barrel (11) and a collar (40, 50) with two pawls (42A, 42B). The plunger has two opposed ratchets (23A, 23B) that align with the one each of the pawls and thereby or impede, withdrawal of the plunger during or following depression of the plunger. The barrel has a collar with an inner (50) and an outer member (40) that are incapable of rotation relative with respect to each other. The outer member has the two pawls (42A, 42B) and two fingers that slidably engage opposed guide slots (28) on the plunger to thereby prevent or minimize rotation of the plunger relative to the collar. The inner member of the collar is operable to prevent engagement of the plunger ratchet by the two pawls until the plunger is depressed. |
