JP2007044478A - Charging stand for electric toothbrush - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem, wherein a rechargeable electric toothbrush is charged by being set in a charger with a toothbrush part side up in the conventional manner, and consequently moisture intrudes into the main body of the toothbrush, which causes corrosion of wiring or electric leakage and hardly gives durability. <P>SOLUTION: The toothbrush part of the rechargeable electric toothbrush is arranged in the lower part and a power source unit (a storage battery) and a charging unit are arranged in the upper part of a charging stand for the rechargeable electric toothbrush. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a charging stand for an electric toothbrush in which a toothbrush portion is driven by a motor.

Conventionally, a charging stand for an electric toothbrush has been structured to charge with the toothbrush portion facing up. The reason is as follows: (1) The charging unit and the battery unit are both heavier and are more stable when placed at the bottom.
(2) It is easier to dry and clean when the toothbrush part is on top.

Problems the invention is trying to solve

The conventional electric toothbrush has the following problems.
1. To charge with the toothbrush part 1 up, in the structure in which the toothbrush part 1 is placed up and the power take-out part 15 is placed down like a conventional product, the polishing powder and moisture held in the toothbrush part 1 are the power take-out part 15 Stop at.
2. The battery unit 7 of the electric toothbrush is repeatedly discharged when the toothbrush is used, and repeatedly charged when set on the charging stand 13. The temperature of the battery unit 7 rises during charging, and gradually decreases with the completion of charging, and eventually returns to room temperature. That is, the battery unit 7 repeats the room temperature and the high temperature state by repeating charging and discharging. As a result, the pressure in the housing 14 fluctuates, and moisture that remains in the power take-out portion 15 is gradually sucked into the interior. As a result, scouring powder and moisture adhering to the periphery of the power take-off shaft 4 flow into the housing 14 from the power take-out portion 15, causing wiring corrosion and electric leakage.
3. In general, mechanical parts operating in a sealed space raise the temperature of the space by Joule heat or frictional heat. This causes the internal gas to expand, increasing the pressure in the housing 14 that forms the sealed space, and thus rupturing. In order to prevent this, generally, a hole connecting this space (the casing 14) and the outside is passed through. This hole is called a breather (air hole).
4. Since the electric toothbrush is washed with water, such a breather cannot be provided, and no hole is provided to prevent moisture from entering. The power takeout portion 15 is also sealed with an O-ring 2 for shaft sealing.
5. Since the O-ring 2 is a donut-shaped elastic body made of rubber, it wears if the power take-out shaft 15 repeats a swinging motion. If the pressure difference between the outside air and the housing 14 is large, the pressure difference between the outside air and the housing 14 is eliminated by elastic deformation. This means that external scouring powder and moisture enter the housing 14.

Means to solve the problem

  When charging the rechargeable electric toothbrush, the charging unit 8 is not set down and the toothbrush part 1 is set up as in the conventional case. Even if the unit 8 is set so as to be on the upper side and the temperature in the case 14 rises during charging or the temperature in the case 14 changes after the completion of charging, The structure is such that moisture or the like that stagnates around 15 can be quickly dropped and moisture does not enter the housing 14.

An embodiment of the present invention will be described with reference to FIGS.

FIG. 2 is a cross-sectional view of the rechargeable electric toothbrush of the present invention set in a charged state.
The cross-sectional part of FIG. 3 shows the fitting state of the storage battery unit 7 and the charging unit 8 and can be set only in a certain direction. (Rotation direction regulation)
The toothbrush portion 1 in FIG. 5 is also structured to engage with the power take-off shaft 4 but is set so as to face a certain direction (the brush portion is upward). (Drain hole 11 is below)
Therefore, when the toothbrush is set in the charging unit 8 immediately after use, the moisture remaining in the toothbrush portion 1 falls down as it is and does not flow into the housing 14.

      State diagram set on the charging stand 13 of a conventional electric toothbrush       The state figure set to the charging stand 13 of the electric toothbrush of this invention       Sectional view of fitting part during charging of the battery unit 7 and the charging unit 8 (A-A section)       Cross section of the electric toothbrush drop prevention projection 10 (B-B cross section)       Cross section of toothbrush mating section (C-C cross section)

Explanation of symbols

1: Toothbrush part 2: Sealing part (O-ring)
3: Electric motor 4: Power take-out shaft 5: Switch 6: Control unit 7: Power supply unit (including storage battery unit)
8: Charging unit 9: Charging fitting portion 10: Drop prevention protrusion 11: Drain hole 12: Toothbrush fitting portion 13: Charging stand 14: Housing 15: Power take-out portion

Claims (1)

An electric toothbrush with a built-in storage battery and charging the storage battery in an inductive charging method in a non-contact manner. Charging stand for toothbrushes.

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