Abstract: A dental handpiece assembly comprising a handgrip and a detachable headpiece. The front end of the handgrip includes an arm that extends forward and below the headpiece. The headpiece carries a dental tool and the handgrip supplies cooling water and air through the extended arm to outlets close to the tool. This arrangement has the advantage that the detachable headpiece does nto need to include passageways for the cooling water and cooling air.

Abstract: A hand held device for generating ultrasonic vibrations comprises an elongated tubular casing having therein a piezoelectric vibrator element and a generator that develops an electrical signal having a predetermined ultrasonic frequency that excites the piezoelectric vibrator element into ultrasonic vibration. A work tool protrudes from the casing and is vibrationally coupled to the piezoelectric vibrator element by a vibratory rod and the rod transmits the vibration from the piezoelectric vibrator element to the work tool. A cooling system is disposed within the casing and flows a cooling agent through the device to cool both the piezoelectric vibrator element and the generator and the cooling agent is discharged from the device in atomized form through an opening in the work tool.

Abstract: A hand held device for generating ultrasonic vibrations comprises an elongate tubular casing having therein a piezoelectric vibratory element comprising an elongate bar of piezoelectric material and a generator that develops an electrical signal having a predetermined ultrasonic frequency that excites the piezoelectric vibratory element into ultrasonic vibration. The piezoelectric vibratory element also functions as the dielectric of a capacitor which constitutes part of the generator and which determines the ultrasonic frequency of the electrical signal output of the generator. A work tool protrudes from the casing and is vibrationally coupled to the piezoelectric vibrator element by a vibratory rod which transmits the vibrations from the piezoelectric vibratory element to the work tool.