Prestressed cylindrical piezoelectric ultrasonic scaler

摘要

The scaler includes a transducer and an energizing circuit. The transducer includes a tubular piezoelectric transducer element which is maintained in compressive stress when energized by an axial tension bolt adapted to mount a vibratory work tool. The energizing circuit drives the transducer element at its resonant frequency and maintains resonant frequency within an optimum band width, despite changes in capacitive reactance of the transducer element produced by torque applied thereto as the work tool is pressed against an object. A fluid delivery system delivers fluid to the work tool via the tension bolt to effect scaling.