摘要 |
A syringe or cartridge having a hollow barrel with an open end and a second end suitable for attaching a needle assembly. A master plunger assembly that includes a master plunger and a plunger member is mounted in the barrel for longitudinal movement therein. A slave plunger is mounted in the barrel for longitudinal movement therein, and is located between the master plunger assembly and the second barrel end so as to define two chambers. The first chamber a liquid chamber and is between the slave plunger and the second barrel end, and the second chamber is a pneumatic chamber and is between the slave plunger and the master plunger assembly. The liquid-containing chamber is suitable for containing a liquid to be dispensed from the syringe, and the pneumatic chamber contains a gas such as air. When the liquid-containing chamber contains a liquid to be dispensed, a user applying selective pressure to the plunger member will cause the master plunger assembly to slide towards the slave plunger and compress the gas against the slave plunger. The slave plunger will as a result of this pressure slide towards the second barrel end as the gas decompresses and apply pressure against the liquid as a result thereof. The liquid will then be dispensed out of the syringe or cartridge via a needle attached to the barrel end.
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