Patent ID: 6760945
Filing Date: 2004-07-13
Classification: A61C

Abstract:
An electric toothbrush comprising:a brush head assembly; a housing; a frame enclosed by the housing; a power supply contained within the housing; an electric coil and core that is secured relative to the frame and electrically connected to the power supply through a control circuit that creates an alternating flow of current in the coil; an elongated driveshaft having a distal end that is connected to the brush head assembly and an internal end that is disposed within the housing; a torsion bar clamped by an anchoring plate to the frame at a first end; a magnet plate having first and second ends, the magnet plate is connected to one of the torsion bar or the driveshaft; at least one magnet arranged on the magnet plate, the magnet being aligned relative to a central axis of the driveshaft, the magnet being located at a radially spaced location relative to the central axis of the shaft, wherein the alternating flow of current in the electric coil at a predetermined frequency causes the first and second ends of the armature magnet plate to be alternately attracted to the coil and core causing the torsion bar to twist and causing the driveshaft to oscillate in an oscillatory rotary motion.