MOTORIZED SYRINGE FOR USE WITH TWO TYPES OF DENTAL ANESTHETIC SOLUTION-CONTAINING CARTRIDGES

摘要

Provided is an electric syringe to be used with two kinds of dental anesthetic solution-containing cartridges, wherein the cartridge holder is configured so as to be capable of being used with both cartridges containing 1.0 mL and 1.8 mL of anesthetic solution and the syringe is configured so that the rubber plunger stopper of the 1.8 mL cartridge can be pushed with a push rod of the length necessary for pushing the rubber plunger stopper of the 1.0 mL cartridge. The cartridge holder (4) used in the electric syringe to be used with two kinds of dental anesthetic solution-containing cartridges is configured so as to be usable with both a 1.0 mL cartridge (3b) and a 1.8 mL cartridge (3a). The push rod (6) has a 1.0 mL cartridge-setting position and a 1.8 mL cartridge-setting position that is drawn back from said position so that the movement of the push rod ends at the same position for both the 1.0 mL cartridge and the 1.8 mL cartridge, and comprises: a bottomed sleeve (22), which accepts the back end of the push rod when pushed back from the ending position and when the push rod is in the 1.0 mL cartridge-setting position, is not affected by the back end face of the push rod but when the push rod is pushed back to the 1.8 mL cartridge-setting position, is pushed backward by the back end face of the push rod; and a returning spring (23) for moving the sleeve together with the push rod forward during forward movement of the push rod.