MECHANICALLY-DRIVEN, SONIC TOOTHBRUSH SYSTEM

• US 20120279002A1
• Filed: 05/02/2012
• Published: 11/08/2012
• Est. Priority Date: 05/02/2011
• Status: Active Grant

• Current Assignee: Water Pik Incorporated (Church & Dwight Company Incorporated)
• Original Assignee: Water Pik Incorporated (Church & Dwight Company Incorporated)
• Inventors: Sokol, Gary L., Luettgen, Harold A.
• Granted Patent: US 8,943,634 B2
• Time in Patent Office: Days
• US Class Current: 15/22.1
• CPC Class Codes: A61C 17/20 using ultrasonics
• CPC Class Codes: A61C 17/26 driven by electric motor
• CPC Class Codes: A61C 17/3418 Rotation around the axis of the toothbrush handle
• CPC Class Codes: A61C 17/3481 Vibrating brush body, e.g. by using eccentric weights

Abstract

A sonic toothbrush system includes an electric motor, a brush shaft, and a drive assembly. The electric motor includes a drive shaft. When the electric motor is caused to operate, the drive shaft continuously rotates until the motor is caused to stop. The drive assembly is coupled between the drive shaft and the brush shaft. The drive assembly is configured to convert the rotation of the drive shaft into sonic oscillation of a toothbrush head supported on an end of the brush shaft.

Claims

1. A sonic toothbrush comprising

an electric motor including a drive shaft, wherein, when the electric motor is caused to operate, the drive shaft continuously rotates until the motor is caused to stop;

a brush shaft; and

a drive assembly coupled between the drive shaft and the brush shaft and configured to convert the rotation of the drive shaft into sonic oscillation of a toothbrush head supported on an end of the brush shaft.

2. The sonic toothbrush of claim 1, wherein the drive assembly includes a coupler and an eccentric pin, wherein the coupler has a first end and a second end, the first end operably coupled to the brush shaft and the eccentric pin rotationally received within the second end, the rotation of the drive shaft causing the eccentric pin to rotate within the second end, the rotation of the eccentric pin causing the coupler to oscillate.

3. The sonic toothbrush of claim 2, wherein the drive assembly further comprises a crank arm interconnected between the drive shaft and the coupler.

4. The sonic toothbrush of claim 3, wherein the crank arm is fixedly connected to the drive shaft on a first side and fixedly connected to a rearward end shaft of the eccentric pin on a second side opposite the first side.

5. The sonic toothbrush of claim 4, wherein the rearward end shaft of the eccentric pin is axially aligned with an axis of the drive shaft and a mid portion of the eccentric pin is axially offset from the axis of the drive shaft.

6. The sonic toothbrush of claim 3, wherein the crank arm further comprises an additional weight component to alter a center of mass of the drive assembly and impart a balance or an imbalance to the drive assembly.

7. The sonic toothbrush of claim 2, wherein the drive assembly further comprises a rocker arm pivotably interconnected between the coupler and the brush shaft.

8. The sonic toothbrush of claim 7, wherein the rocker arm pivotably connects to the coupler at a first axis of rotation and the brush shaft pivotably connects to the coupler at a second axis of rotation.

9. The sonic toothbrush of claim 7, wherein the rocker arm further comprises an additional weight component to alter a center of mass of the drive assembly and impart a balance or an imbalance to the drive assembly.

10. The sonic toothbrush of claim 2 further comprising

a crank arm interconnected between the drive shaft and the coupler;

a rocker arm interconnected between the coupler and the brush shaft;

one or more additional weight components attached to either the crank arm or the rocker arm, or both, to alter a center of mass of the drive assembly and impart a balance or imbalance to the drive assembly.

11. The sonic toothbrush of claim 1 further comprising

a handle portion housing the electric motor;

and

a power source housed within the handle portion and electrically connected with the electric motor.

12. The sonic toothbrush of claim 1 further comprising a bracket to which the electric motor is attached and to which the brush shaft is rotationally mounted.

13. The sonic toothbrush of claim 1, wherein the electric motor continuously rotates at a speed of between 12,000 rpm and 18,000 rpm.

14. A sonic toothbrush providing oscillating bristle motion comprising

a continuously rotating drive system;

a brush shaft; and

a linkage between the drive system and the brush shaft that provides oscillating, sonic speed output motion to the brush shaft with an extremely low level of mechanical vibration and noise.

15. The sonic toothbrush of claim 14, wherein the linkage further comprises one or more removable mass components that may be removed and replaced with other removable mass components of differing mass to alter a center of mass of the linkage and impart a balance or an imbalance to the linkage.

16. The sonic toothbrush of claim 14, wherein an output shaft of the drive system is axially offset from an axis of the brush shaft.

17. The sonic toothbrush of claim 14, wherein the linkage comprises a cam that causes a portion of the linkage to revolve about an output shaft of the drive system.

18. The sonic toothbrush of claim 14, wherein an oscillating motion of the brush shaft is between 200 and 300 cycles per second.

19. A method of designing a sonic toothbrush having a continuously rotating drive system, a brush shaft, and a linkage between the drive system and the brush shaft, the method comprising

performing a finite element analysis on the linkage;

determining a weight distribution in the linkage based upon the finite element analysis to position a center of mass of the linkage and impart a balance or a selected imbalance to the linkage.

20. The method of claim 19 further comprising adjusting one or more replaceable weights within the linkage to alter the center of mass or alter the selected imbalance.