JPH0518973Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Technical Field) The present invention relates to an electric toothbrush, and more particularly to an electric toothbrush in which a toothbrush attached to a drive shaft reciprocates in the direction of the drive shaft.

(Background technology) Conventionally, this type of electric toothbrush
-43981, etc., and these electric toothbrushes use a waterproof cap to keep the area around the drive shaft waterproof. This waterproof cap is usually formed into a substantially conical shape, the center part of which is fitted onto the drive shaft, and the outer peripheral edge of the lower end is attached to the upper end of the main body housing. It is pulled vertically as it reciprocates, and if the drive shaft is tilted or the thickness of the waterproof cap is not constant, the waterproof cap will change shape unevenly. In other words, when the drive shaft moves downward, the waterproof cap is not recessed concentrically with respect to the drive shaft, but is recessed in a partially biased state, which applies uneven and excessive force to the waterproof cap, causing its deterioration. The disadvantage is that it promotes this and shortens lifespan. In addition, such a phenomenon is not desirable in terms of appearance, and the forced deformation of the waterproof cap increases energy loss and reduces the efficiency of the electric toothbrush as a whole.

In particular, when you turn off the electric toothbrush to stop its operation, if the drive shaft moves downward and unreasonable force is applied to the waterproof cap, the deterioration of the waterproof cap will progress further. It was hot.

(Purpose of the invention) The present invention was proposed in view of the above points, and its purpose is to easily deform the waterproof cap that follows the drive shaft, prevent its deterioration, and extend its life. An object of the present invention is to provide an electric toothbrush with improved appearance and overall efficiency.

(Disclosure of the invention) The invention will be described below with reference to the drawings. First of all
1 to 5 show an embodiment of the present invention, and FIGS. 1 and 2 show the structure of a waterproof cap 1. FIG. In these figures, the waterproof cap 1 is integrally molded from rubber or the like, and includes a large-diameter mounting cylinder 2 that is attached to the upper end of a casing 6, which will be described later, and a large-diameter mounting cylinder 2 that is attached to the upper center of the mounting cylinder 2. It is composed of a small-diameter shaft holding cylindrical portion 3 and a circumferential side portion 4 having a conical circumferential surface shape that connects these mounting cylindrical portion 2 and shaft holding cylindrical portion 3, and has an approximately conical shape as a whole. The circumferential side part 4 has a circumferential side part 4.
An annular thin wall portion 5 that is thinner than other portions of the
is formed concentrically with a drive shaft 24, which will be described later.

Therefore, the shaft holding cylinder part 3 is fitted onto a drive shaft 24, which will be described later.
4 can be moved up and down as the drive shaft 4 moves up and down, and at this time, the circumferential side portion 4 is bent at the thin wall portion 5 as a boundary, as shown in FIG. 2, and is deformed concentrically with respect to the drive shaft 24. .

Next, the overall structure of an electric toothbrush using this waterproof cap 1 will be described in detail with reference to FIGS. 3 and 4. In these figures, 6 is a cylindrical casing in which a motor 7 and a storage battery 8 are housed. Output shaft 7a of motor 7
A pinion 9 is meshed with the pinion 9, and the pinion 9 has a shaft hole 11 in the center, as shown in detail in FIG. A face gear 10 having a cam groove 12 formed therein is engaged with the face gear 10.

The eccentric cam 13 disposed close to the face gear 10 is formed into a substantially cylindrical shape as shown in FIG. A hole 15 is formed. Here, the boss 14 is the face gear 1
It is slidably engaged with the cam groove 12 of 0,
The eccentric cam 13 and the face gear 10 are connected to a support shaft 16 (see FIG. 3) that is press-fitted into the shaft hole 11 through the elongated hole 15.
The support shaft 16 is integrated by penetrating the support shaft 16
Both ends are pivotally supported on the inner surfaces of chassis 17 and chassis 18. Note that the chassis 17 and the chassis 18 are connected and fixed by a method such as an undercut.

Further, as shown in FIG. 4, the eccentric cam 13 is slidably engaged with a perfect circular engagement portion 20 of a drive element 19 housed inside the casing 6, and the Eccentric cam 13, face gear 1
A drive mechanism section 21 is constituted by the 0, pinion 9, and the like. The drive element 19 is held between the chassis 17 and 18 via a ball 22, as shown in FIG.
7 and is positioned and fixed.

Next, the above-mentioned waterproof cap 1 is attached by fitting its mounting cylinder portion 2 to the upper end of the casing 6 and then attaching the annular ring 23. On the other hand, a drive shaft 24 is fitted into the upper end of the driver 19, and this drive shaft 24 passes through a hole in the shaft holding cylinder 3 of the waterproof cap 1 in a watertight manner, and a toothbrush 25 is attached to the upper end of the drive shaft 24. connected. This toothbrush 25 is formed by implanting a large number of brushes 27 made of nylon or the like on the tip of a long handle 26 made of a synthetic resin material such as plastic.
The drive shaft 24 is detachably attached by fitting the tip of the drive shaft 24 into a recess 29 formed at the lower end of the handle 26 . In addition, in FIG. 3, 28 indicates a switch.

In this embodiment, the motor 7, storage battery 8, and drive mechanism section 2 are placed on the chassis 17 during assembly.
1 can all be incorporated, making assembly work easy, and
The waterproof cap 1 has an annular ring 23 attached to the mounting tube 2 in advance, and then a casing 6 is attached from below.

Next, to explain this operation, the rotation of the motor 7 is transmitted to the face gear 10 via the pinion 9, and then converted into reciprocating motion by the eccentric cam 13 and the driver 19, thereby causing the drive shaft 24 and the toothbrush to rotate. 25 reciprocates. Here, by configuring the motor 7 to be capable of forward and reverse rotation, the cam groove 12 formed in the face gear 10, the boss 14 that engages with this cam groove 12, the long hole 15 of the eccentric cam 13, and the support shaft 16 etc., the amount of reciprocating motion of the toothbrush 25 can be made variable.

When the toothbrush 25 reciprocates in this manner, the presence of the thin walled portion 5 concentric with the drive shaft 24 on the circumferential side portion 4 of the waterproof cap 1 facilitates deformation in this portion, as shown in FIG. As shown in FIG. 3, the waterproof cap 1 quickly deforms and returns repeatedly without being subjected to excessive force. Additionally, as the toothbrush 25 reciprocates, force is concentrated on the mounting cylinder part 2 and shaft holding cylinder part 3 of the waterproof cap 1 in the past, and these parts tend to deteriorate, but the thin wall part 5 is effective against these parts. Since it absorbs and disperses the force applied to the mounting tube 2, it is possible to prevent deterioration of the mounting tube 2 and the like.

Next, FIG. 6 shows another embodiment of the present invention, in which a convex thick wall is provided on the circumferential side 4' of the waterproof cap 1', which is thicker than other parts. A portion 5″ is formed concentrically with the drive shaft 24,
As a result, a thin wall portion 5' that is concentric with the drive shaft 24 is formed in a portion other than the thick wall section 5'',
The other structural members are the same as in the previous embodiment. According to this embodiment, the rigidity of the thick wall portion 5'' formed in a convex shape is high, and deformation is likely to occur in the concentric thin wall portion 5' other than the thick wall portion 5'' in the circumferential side portion 4'. Therefore, as in the previous embodiment, the peripheral side portion 4' deforms easily.

(Effect of the invention) As described above, according to the invention, in the electric toothbrush in which the toothbrush is attached to the drive shaft protruding from the end of the casing and the toothbrush is reciprocated in the axial direction of the drive shaft, the a small-diameter shaft-holding cylindrical portion into which the drive shaft fits; a large-diameter mounting cylindrical portion attached to the circumferential side end of the casing; and a generally truncated conical shape that connects the shaft-holding cylindrical portion and the mounting cylindrical portion. Since the thin-walled portion is provided on the circumferential side of the waterproof cap concentrically with the drive shaft, the deformation adjustment portion formed in this manner allows the deformed portion, that is, the thin-walled portion, to be adjusted. The waterproof cap can be deformed almost concentrically at all times, which has the effect of preventing unreasonable deformation of the waterproof cap and preventing its deterioration and damage.

Furthermore, since the waterproof cap has an annular thin-walled part, it looks good when deformed, and since no excessive load is applied to the thin-walled part, there is no loss of energy, and there is no inconvenience such as excessive load being applied to the motor. There are also effects such as being resolved.

[Brief explanation of the drawing]

Figures 1 to 5 show an embodiment of the present invention, in which Figure 1A is a vertical sectional view of the waterproof cap, Figure 1B is a bottom view, and Figure 2 is an explanation showing the deformed state of the waterproof cap. 3 is a vertical sectional view showing the overall structure, FIG. 4 is a sectional view taken along line AA in FIG. 3, FIG. 5 is an exploded perspective view of the main parts, and FIG. A vertical cross-sectional view of the waterproof cap in the example, and the same figure is a plan view. 1, 1'...Waterproof cap, 2...Mounting cylinder part,
3... Shaft holding cylinder part, 4, 4'... Circumferential side part, 5,
5'... Thin wall part, 6... Casing, 24... Drive shaft, 25... Toothbrush.

Claims (1)

[Scope of utility model registration request] A toothbrush is attached to a drive shaft protruding from an end of a casing, and the toothbrush is reciprocated in the axial direction of the drive shaft. The waterproof cap includes a large-diameter mounting cylinder attached to an end of the circumferential side of the casing, and a substantially truncated conical circumferential side that connects the shaft holding cylinder and the mounting cylinder. An electric toothbrush characterized in that a thin wall portion is disposed on a circumferential side of the toothbrush concentrically with the drive shaft.