US 5,613,259 A · High frequency electric toothbrush

Abstract

An electric oscillating tool, having particular but not necessarily exclusive utility as an electric toothbrush, for driving a brush head assembly or end effector with a resonant mechanism at high frequencies. The electric toothbrush includes handle housing, an electromagnetic motor mounted in the housing, and a mechanical oscillator acted upon by the motor. One end of the mechanical oscillator extends outwardly through an opening in the handle housing while the other end is attached to the housing inside the chamber. The end effector/brush head assembly attaches to the extending end of the mechanical oscillator. A power source supplies an alternating current drive signal to the motor, in turn causing the armature and the mechanical oscillator to oscillate and drive the brush head assembly. Control circuitry senses the frequency of oscillation of the mechanical oscillator and controls the frequency of the drive signal to maintain the mechanical oscillator at resonance under the variety of loads imposed during use.

Claims18

Dependent claims

An oscillating tool comprising:

a. a tubular handle housing defining an interior chamber and an axial opening at one end thereof,
b. an electromagnetic motor mounted in said chamber, said motor including an oscillatable armature,
c. a mechanical oscillator having a first end and a second end, said mechanical oscillator integrally formed with said armature, said mechanical oscillator having a resonant frequency, said first end of said mechanical oscillator extending outwardly beyond said housing through said opening, and said second end being operably attached to said handle housing,
d. a power source operatively connected to said motor, said power source supplying an alternating current drive signal to said motor actuating said armature and said mechanical oscillator to effect oscillation thereof,
e. an oscillation sensor mounted on said housing in juxtaposition with said armature and generating a sensor signal in response to the oscillation of said armature, and
f. a control circuit receiving said sensor signal and altering the frequency of said drive signal applied to said motor in response to said sensor signal.

3 more elements

An oscillating tool comprising:

a. a handle housing defining an interior chamber;
b. an electromagnetic motor having a oscillatable armature, said armature having a portion positioned in said interior chamber;
c. a drive shaft integrally formed with said armature and extending longitudinally inside said interior chamber, and having an upper end extending through said housing;
d. a spring having an upper end operably attached to said handle housing and a lower end attached to a lower end of said drive shaft, said drive shaft and spring in conjunction having a resonant frequency,
e. a power source operatively connected to said motor, said power source supplying an alternating current drive signal to said motor for actuating said armature and said drive shaft and said spring to effect oscillation thereof,
f. an oscillation sensor mounted in said housing in juxtaposition with said armature and generating a signal in response to the oscillation of said armature, and
g. a control circuit receiving said sensor signal and altering the frequency of said drive signal applied to said motor in response to said sensor signal.

4 more elements

Dependencies are inferred from the claim text.

High frequency electric toothbrush

Life of this patent

High frequency electric toothbrush

Life of this patent

Abstract

Claims18