JPH07116020A - Motor-driven toothbrush - Google Patents

Abstract

PURPOSE:To provide a motor-driven toothbrush capable of rotating a rotary brush body surely without disengagement between a rack and a pinion. CONSTITUTION:A rotary brush 11 is arranged to rotate freely at the tip of an attachment 10 connected to a drive shaft 8. An extension bar 15 relatively movable with respect to the attachment 10 while it is put inside the attachment 10 and connected to a fixed shaft 9 in a case 1 when the attachment 10 is connected to the drive shaft 8. A pinion 13 is arranged at the rotary shaft of a rotary brush body 11 while a rack 15a is formed. At the rear side restriction means 20 for preventing the rack 15a from being displaced to the opposite side to the pinion 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric toothbrush.

[0002]

2. Description of the Related Art A large number of electric toothbrushes have been proposed in the past, and a wide variety of electric toothbrushes are commercially available to date. Among them, the representative one is
An attachment having a brush body at its upper end is provided so as to be movable and detachable relative to the case, and is driven in the longitudinal direction by a motor provided inside the case. Alternatively, instead of the attachment, there is one in which the brush body itself is driven. For example, Japanese Examined Patent Publication No. 61-55963 discloses an electric toothbrush in which the tips of the brushes vibrate finely. Further, Japanese Patent Application Laid-Open No. 61-64204 discloses an electric toothbrush that reciprocates a toothbrush attached to a drive shaft in the axial direction or the direction perpendicular to the axis.

Further, Japanese Patent Laid-Open No. 61-79410 discloses an electric toothbrush in which the stroke of the axial reciprocating motion applied to the toothbrush is variable. Among the above-mentioned conventional techniques, the one that gives fine vibration to the toothbrush absorbs this fine vibration when the toothbrush body is strongly held, and the vibration displacement of the brush becomes close to zero, resulting in tooth brushing. The action is reduced. Further, in the case where the attachment portion having the brush body (the portion corresponding to the handle of a normal toothbrush) is given a motion, the brush body itself is fixed to the attachment and is immovable. Further, in the case where the brush body itself is made to rotate, the attachment portion having the brush body is immovable. In view of such a situation, the applicant of the present application, in Japanese Patent Application No. 5-35301, gives an attachment having a brush body a reciprocating motion in the axial direction, and at the same time, rotates the brush body itself provided in the attachment. We propose an electric toothbrush with excellent brushing effect by giving exercise. In this earlier application, FIG.
As shown in FIG. 1, the pinion 13 provided on the rotary shaft of the rotating brush body (not shown) rotatably provided at the tip of the attachment 10 is fixedly provided on the extension bar 1
By rolling on the rack 15a provided at the tip of No. 5, the rotating brush body reciprocally rotates on the attachment 10.

[0004]

As shown in FIG. 1, when the length of the rack 15a itself (the length in the vertical direction in FIG. 1) is large, the rack 15a is displaced to the side opposite to the side where the pinion 13 is located. May occur (broken line in FIG. 1). If the rack 15a is displaced in this way, the engagement between the rack 15a and the pinion 13 will be disengaged, and as a result, even if the attachment 10 reciprocates in the vertical direction (axial direction), the rotary brush body will not move. There is a possibility that a problem such as not rotating on 10 may occur. The object of the present invention is to provide the rack 15a on the side opposite to the side on which the pinion 13 is located (see FIG.
It is intended to provide an electric toothbrush that can prevent the displacement of the rack 15a and the pinion 13 reliably and can reliably rotate the rotating brush body.

[0005]

In order to solve the above-mentioned problems, an electric toothbrush according to the present invention has a drive shaft supported movably in an axial direction inside a case, and a drive model provided inside the case. The rotation of the rotor is converted into reciprocating motion by the first motion conversion mechanism and transmitted to the drive shaft, and the rotary brush is rotatably provided at the tip of the attachment connected to the drive shaft. Yes, it is connected to a fixed shaft that is provided inside the attachment and that is fixedly provided inside the case when the attachment is connected to the drive shaft, and is movable relative to the attachment. A rack is provided on the extension bar, and a pinion provided on the rotary shaft of the rotating brush body is provided so as to mesh with the rack and the rack is provided on the back side of the rack. Click is characterized in that the regulating means for preventing the displacement to the side opposite to the pinion is provided. Preferably, a rolling bearing is used as the regulation means. More preferably, the front end and the rear end of the rolling bearing are provided with ribs to which the extension bars fit.

[0006]

EXAMPLE A first example of the present invention will be described with reference to FIGS. As shown in FIGS. 2 and 3, a DC motor 2 driven by a dry battery (not shown) is provided through a support member 3 inside a hollow cylindrical case 1 having an opening 1a at its upper end. is there. The support member 3 has a bevel gear 4 and a shaft 5
It is provided rotatably through. The teeth of the bevel gear 4 mesh with the motor pinion 6 provided on the DC motor 2.

An eccentric cam 4a is integrally formed on the side surface of the bevel gear 4, and a cam follower 7 is attached to the eccentric cam 4a.
Are engaged. As shown in FIG. 1, the cam follower 7 has an opening 7a having a height equal to the diameter of the eccentric cam 4a.
The eccentric cam 4a is fitted in the opening 7a. One-way rotation about the shaft 5 of the bevel gear 4 is converted into vertical reciprocating motion by the cam follower 7 that follows the rotation of the eccentric cam 4a. The eccentric cam 4a and the cam follower 7 constitute a first motion conversion mechanism that converts the rotation of the DC motor 2 into a reciprocating motion. A hollow drive shaft 8 is slidably supported in the upper center of the support member 3 along the axial direction (vertical direction in FIG. 2). The lower end of the drive shaft 8 is connected to the arm portion 7b above the cam follower 7, and the vertical reciprocating motion of the cam follower 7 is transmitted to the drive shaft 8. A fixed shaft 9 is coaxially penetrated through the hollow inside of the drive shaft 8, and a lower end portion of the fixed shaft 9 is bent in an L shape and protrudes from a cutout portion 8a of the drive shaft 8. The protruding end 9 a is fixed to the inner wall of the support member 3. In addition,
Water that has entered through the upper opening 1a of the case 1 is not supported by the support member 3
This prevents the DC motor 2 and the bevel gear 4 from entering the case 1 provided therein. An attachment 10 having an opening 10a at the lower end is detachably attached to the tip of the drive shaft 8 via a connecting adapter 16 described later. Therefore, the attachment 10 is reciprocally driven in the vertical direction relative to the case 1 integrally with the drive shaft 8. A shaft 12 is provided inside the tip of the attachment 10. A rotary brush body 1 having a plurality of brushes via the shaft 12.
1 is rotatably and detachably attached to the attachment 10. A pinion 13 that rotates integrally with the rotating brush body 11 is pivotally supported on a shaft 12 that is the center of rotation of the rotating brush body 11. Inside the attachment 10, a plurality of convex portions 10b are formed. This convex portion 10b
Thus, the extension bar 15 is supported inside the attachment 10 so as to be slidable along its axial direction (the vertical direction in FIG. 1). An upper end portion of the extension bar 15 is bent in an L shape, and a rack 15a that meshes with a tooth portion of the pinion 13 is formed in the bent portion. A water drain hole 10c for draining water that has entered between the attachment 10 and the rotating brush body 11 is formed on the outer peripheral surface of the attachment 10. A connection adapter 16 having a through hole 16a in the center thereof is fixed to the lower portion of the attachment 10. As shown in FIG. 4, the lower end of the through hole 16a of the connecting adapter 16 is adapted to be connected to the upper end of the drive shaft 8 when the attachment 10 is inserted into the upper end opening 1a of the case 1. Therefore,
The attachment 10 is reciprocally driven in the up-down direction relative to the case 1 integrally with the drive shaft 8. In addition, the connection adapter 16 is connected to the drive shaft 8 in this way.
When mounted on, the upper end of the fixed shaft 9 penetrating the drive shaft 8 protrudes through the through hole 16a of the connection adapter 16 and enters the inside of the attachment 10. Stretch bar
A coupling coupler 17 having an opening 17a at its lower end is fixedly attached to the lower end of 15. The opening 17a of the connecting coupler 17 is the connecting adapter 1 of the attachment 10.
When 6 is mounted on the drive shaft 8, it is connected to the upper end of the fixed shaft 9. Therefore, the attachment 10 integrally moves with the drive shaft 8 in the vertical direction with respect to the case 1, but the extension bar 15 connected with the fixed shaft 9.
Remains immobile with respect to case 1. Therefore, as shown in FIG. 3, as the attachment 10 moves up and down, the pinion 13 that meshes with the rack 15a at the upper end of the extension bar 15 reciprocally rotates about the shaft 12. The rotary motion of the pinion 13 is directly transmitted to the rotary brush body 11, and the rotary brush body 11 reciprocally rotates on the attachment 10. In this way, the pinion 13 and the rack 15a
By, the vertical direction of the attachment 10 (axial direction)
It constitutes a second motion conversion mechanism for converting the reciprocating motion of the above into a rotary motion. As shown in FIGS. 2, 4 and 5, inside the tip of the attachment 10, a restricting means for engaging with the surface 15b on the opposite side of the rack 15a and restricting the displacement of the rack 15a to the left in FIG. The rolling bearing 20 is
It is rotatably supported on the fixed shaft 21. Here, the rolling bearing 20 has a pipe shape, and its outer peripheral surface is
It is always engaged with the opposite surface 15b of the rack 15a.
Next, the operation will be described. Grasping the outer peripheral surface of the case 1 and turning on a switch (not shown), the DC motor 2
Rotates. The rotation of the DC motor 2 is converted into reciprocating motion in the longitudinal direction of the case 1 by the eccentric cam 4a and the cam follower 7 which are the first motion converting mechanism, and is driven through the motor pinion 6 and the bevel gear 4. The attachment 10 that is transmitted to the shaft 8 and is integral with the drive shaft 8 reciprocates in the vertical direction with respect to the case 1. When the attachment 10 moves in the vertical direction, the pinion 13 meshing with the rack 15a at the upper end of the extension bar 15 connected to the fixed shaft 9 fixed to the case 1 reciprocally rotates about the shaft 12, The rotary brush body 11 reciprocally rotates at the tip of the attachment 10. Here, as shown in FIGS.
Since the surface 15b on the opposite side of 5a is always engaged with the outer peripheral surface of the rolling bearing 20 which is rotatably supported,
As shown in (Conventional structure), even if the length of the rack 15a itself (the length in the vertical direction in FIG. 1) is large, the rack 15a
Displacement of a to the side opposite to the side where the pinion 13 is located is restricted, and the engagement between the rack 15a and the pinion 13 will not be disengaged. Next, a second embodiment of the present invention will be described with reference to FIG. Here, the substantially same parts as those in the first embodiment described above are designated by the same reference numerals, and the description thereof will be omitted. At the front end and the rear end of the rolling bearing 30,
Ribs 30a that engage the opposite surface 15b of the rack 15a
And 30b are integrally formed. Therefore, the surface 15b on the opposite side of the rack 15a is formed on the rolling bearing 3
The rack 15a is positioned in the recess formed between the ribs 30a and 30b, and the rack 15a is restricted from displacing to the side opposite to the side where the pinion 13 is located. It is also possible to prevent swinging in the vertical direction of FIG. 6).

[0008]

As described above, according to the electric toothbrush of the present invention, the rack is provided with the regulating means for preventing the rack from displacing to the side opposite to the pinion on the back side. Even if the length of itself is large, the rack is restricted from displacing to the side opposite to the side where the pinion is located, and the engagement between the rack and the pinion does not come off.
It is possible to provide an electric toothbrush with an excellent toothbrushing effect that can reliably rotate the rotating brush body with a simple configuration and at low cost (the effect of claim 1). Further, if the above-mentioned regulation means is a rolling bearing, sliding between the back side of the rack and the regulation means can be made smooth (effect of claim 2). Furthermore, by providing ribs at the front end and the rear end of the above-mentioned rolling bearing, it is possible to restrict the rack from displacing to the side opposite to the side where the pinion is located, and at the same time the rack moves in the front-back direction (the direction of the pinion rotation center axis). ) Can also be prevented (effect of claim 3).

[Brief description of drawings]

FIG. 1 is an enlarged sectional view of a main part showing a conventional configuration.

FIG. 2 is a sectional front view showing a first embodiment.

3 is a cross-sectional view taken along the line AA of FIG.

FIG. 4 is an enlarged cross-sectional view of a main part.

5 is a sectional view taken along line BB of FIG.

FIG. 6 is an enlarged cross-sectional view of a main part showing a second embodiment.

[Explanation of symbols]

 1 case 2 drive motor 4a, 7 1st motion conversion mechanism 8 drive shaft 9 fixed shaft 10 attachment 11 rotating brush body 13, 15a 2nd motion conversion mechanism 15 extension bar 20, 30 regulating means (rolling bearing ) 30a, 30b rib

Claims (3)

[Claims] 1. A drive motor provided inside the case,
A drive shaft supported movably in the axial direction inside the case; a first motion conversion mechanism for converting the rotation of the drive motor into a reciprocating motion and transmitting the reciprocating motion to the drive shaft; and the drive shaft. An attachment to be connected, a rotating brush body rotatably provided at the tip of the attachment, and a fixed inside the case when the attachment is provided inside the attachment and the attachment is connected to the drive shaft. An extension bar that is connected to a fixed shaft provided and is movable relative to the attachment,
The rack provided on the stretch bar and a pinion that meshes with the rack and is provided on the rotary shaft of the rotary brush body are provided, and the rack is opposite to the pinion on the back side of the rack. An electric toothbrush, characterized in that a regulating means is provided for preventing the toothbrush from being displaced to the side. 2. The electric toothbrush according to claim 1, wherein the restricting means is a rolling bearing. 3. The front end and the rear end of the rolling bearing are
The electric toothbrush according to claim 2, wherein each of the ribs to which the extending bar is fitted is provided.