| 摘要 |
Apparatus for injecting dental local anaesthetic comprises a chamber 18 holding a cartridge 26 containing 1.8ml of anaesthetic. To make an injection, a plunger 22 attached to a slidable bung 28 of the cartridge 26 is depressed in the direction of arrow A to deliver the anaesthetic by way of a needle 20 having a tail 20 perforating a septum 12 at the forward end of the cartridge 26. The chamber 18 is configured and arranged to hold a standard (2.2ml) cartridge as a snug fit therein but a tubular packing piece 24 allows it to accommodate the 1.8ml cartridge 26. Aspiration can be carried out before the injection is administered, by slightly retracting the plunger 22, and different sizes of packing pieces may be used in association with different sized cartridges. |
