Dental syringe

Claim 1

A precision injection system for intraligmental anesthesia and the like comprising, an intraligmental syringe having a tubular handle portion and at least one exchangeable tubular headpiece mountable on and dismountable from the handle portion for exchange thereof with other individual headpieces, means for removably and releasably mounting the headpiece coaxially with the tubular handle portion extending longitudinally therefrom for jointly defining therewith a tubular syringe, the headpiece having at an end thereof a threaded nozzle for removably mounting individual replaceable injection needles each having a needle point, the headpiece defining a viewing chamber for carpule control and dimensioned for receiving therein and containing a carpule cartridge with contents therein to be injected, a dosing plunger housed in the handle portion in a retracted starting position, a servo-dosing lever mounted externally on the tubular handle portion for activating the dosing plunger for incremental gradual advancing movement axially out of said handle portion from the starting position into said viewing chamber of the headpiece to effect delivery of metered quantities of contents of the carpule cartridge for flow through the needle point of an injection needle in dependence upon the incremental axial advancing movement of the dosing plunger, activating means on the tubular handle portion coactive with the servo-dosing lever and dosing plunger for activating the dosing plunger incrementally each time the servo-dosing lever is depressed, and means comprising a resetting key on the handle portion actuatable manually for semiautomatic retraction of the dosing plunger to the retracted starting position.