JPH06165713A - Motor tooth brush - Google Patents

Abstract

PURPOSE:To provide a motor tooth brush for preventing teeth and gums from injuries by interrupting power transmission according to the overload caused by a tooth brush body pressed against the teeth and gums so hard that it has a bad influence upon them. CONSTITUTION:In a motor tooth brush, the movement of a tooth brush body A is changed over between a buss system one and rolling system one by changing over the rotational direction of a motor 1. A leaf spring 7 is interposed between a crown gear 6 needed for changing the rotational direction of the motor 1 and an eccentric cam body 8 to give reciprocating straight movement needed for the buss motion and rolling motion of the tooth brush body A to a cam follower 13 so that both gear and cam body are normally connected to each other with a predetermined frictional force by an elastic force of the leaf spring 7 to be rotated integrally. When an overload is applied to the tooth brush body A, a rotation blocking force caused along with the overload overcomes the frictional force to idle the crown gear 6 so that the power transmission from the motor 1 to the tooth brush body A is interrupted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to, for example, a toothbrush body in which bristles which have been bristled in a normal form are reciprocally rotated about an axis or reciprocated linearly in an axial direction, or toothbrushes themselves which are flocked on a circumference are themselves provided. The present invention relates to an electric toothbrush for assisting tooth brushing by rotating or reciprocally rotating the shaft around its axis.

[0002]

2. Description of the Related Art Various electric toothbrushes of this kind have been developed according to their purpose. For example, a reciprocating rotary motion of a normal form toothbrush is generally called a rolling system, and a reciprocating linear motion of the toothbrush in an axial direction is called a bath system. Further, a scrub type electric toothbrush has been developed and put into practical use, in which the toothbrush body itself having the bristles planted on the circumference is rotated or reciprocally rotated about its axis.

The various movements of the toothbrush body are mechanically converted from the rotational movement of the motor by a movement conversion mechanism for supplying a rotational movement or a movement movement corresponding to the desired movement of the toothbrush body to the drive shaft. Will be realized. Further, among the various electric toothbrushes, there is one in which the motion of the toothbrush body can be switched variously by a switch operation. Furthermore, an electric toothbrush has been developed in which the speed of movement of the toothbrush body can be increased or decreased by a switch in consideration of the influence on the teeth and gums.

[0004]

When brushing teeth with these electric toothbrushes, the toothbrush body tends to be strongly pressed against the teeth and gums because the toothbrushing effect can be efficiently obtained. However, even if the toothbrush body is pressed so strongly as to have a bad effect on the teeth and gums, the movement of the toothbrush body does not always stop, and if the tooth brushing operation is continued in such a state, the teeth and gums are naturally damaged. I will let you.

Further, in the electric toothbrush in which the movement speed of the toothbrush body is variable, even if the movement speed of the toothbrush body is slowed down, when the toothbrush body is strongly pressed so as to adversely affect the teeth and gums, As long as the motion does not stop, the same problem as above occurs regardless of the slow motion speed. Further, with respect to overload when the toothbrush body is pressed so strongly as to adversely affect the teeth and gums, bending occurs at the connecting portion between the toothbrush body and the drive shaft, causing the user to recognize the overload. Such an electric toothbrush has also been proposed. However, this electric toothbrush has a problem that the structure becomes very complicated and thus the cost becomes high.

The present invention has been developed in view of these problems, and the tooth transmission is interrupted by shutting off power transmission in response to overload when the toothbrush body is pressed so strongly that it adversely affects the teeth and gums. An object of the present invention is to provide a low-cost electric toothbrush capable of preventing damage to the teeth and gums.

[0007]

SUMMARY OF THE INVENTION An electric toothbrush according to the present invention comprises a motor, a drive shaft which is connected to the toothbrush and is rotatable or movable in accordance with a desired motion of the toothbrush, and a rotary motion of the motor. A motion converting mechanism for converting the above into a rotational motion or a moving motion in accordance with the desired motion of the toothbrush body, an overload applied to the toothbrush body in the power transmission path between the motor and the drive shaft. According to the above, a power transmission cutoff mechanism for cutting off the transmission of power is provided.

[0008]

In the electric toothbrush of the present invention, the power transmission cutoff mechanism for cutting off the power transmission according to the overload applied to the toothbrush body is provided in the power transmission path between the motor and the drive shaft. The lower limit of the load is set to a load that strongly pushes the toothbrush body against the teeth and gums and adversely affects them, and when an overload of more than this load is applied to the toothbrush body, the transmission of power is cut off and the toothbrush body is stopped. With the structure, it is possible to prevent damage to the teeth and gums. Further, by adopting a specific means such as a friction contact structure for such an overload power transmission / interruption mechanism, the structure is simplified and an increase in cost can be suppressed.

[0009]

1 and 2 show an embodiment of the electric toothbrush according to the present invention. In this electric toothbrush, the bus system and the rolling system can be switched by switching the rotation direction of the motor. In these drawings, the motor 1 is attached to the casing 21 so that the rotation shaft 20 thereof projects inside the casing 21, and the pinion 2 is attached to the rotation shaft 20. Further, in the casing 21, a drive shaft 3 for driving the toothbrush body A by connecting the toothbrush body A on an axis parallel to the axis of rotation of the rotary shaft 20 of the motor 1 is disposed in front of the rotary shaft 20 of the motor 1. The drive shaft 3 is attached to the casing 21 by a bush 22 shown in phantom in FIG. 1 so as to be rotatable about its own axis and linearly movable in its axial direction. A connecting body 23 of the toothbrush body A that is planted on the tip end portion of the drive shaft 3 that protrudes from the casing 21 is detachably attached to the tip end portion of the drive shaft 3 that extends in the axial direction. A substantially cylindrical support body 4 that firmly holds the drive shaft 3 is tightly fitted to the rear end portion of the drive shaft 3 that protrudes inside the casing 21. By swinging, the toothbrush body A can be moved in a bath method or a rolling method.

On the other hand, at a predetermined position of the casing 21, a central shaft 5 whose axis is orthogonal to the rotary shaft 20 of the motor 1 is arranged. A crown gear 6 meshing with a pinion 2 mounted on a rotary shaft 20 of the motor 1 is rotatably mounted on the central shaft 5 with its tooth portion 24 facing downward. A circular penetrating recess 25 is formed in the center of the crown gear 6, and the central shaft 5 penetrates into the penetrating recess 25.

An eccentric cam body 8 which is eccentrically rotated with respect to the axis of the crown gear 6 is attached to the crown gear 6 via a ring-shaped leaf spring 7 having a predetermined elastic coefficient. The eccentric cam body 8 has a disc-shaped pressing portion 9 housed inside the tooth portion 24 of the crown gear 6, and a projection portion provided above the center of rotation of the pressing portion 9 to protrude from the crown gear 6. A cylindrical penetrating portion 10 sized to be tightly penetrated into the penetrating recess 25, and a cylindrical cam portion 11 eccentric to the axis of the pressing portion 9 and protruding below the pressing portion 9. Become. Then, the central shaft 5 is passed through a through hole 26 that vertically passes through the eccentric cam body 8 through the axis of the pressing portion 9. In the eccentric cam body 8, the ring-shaped leaf spring 7 is housed in a circumferential storage groove 27 formed on the upper surface of the pressing portion 9, and the penetrating portion 10 is formed in the penetrating concave portion 25 of the crown gear 6. The leaf spring 7 which penetrates through and pushes the leaf spring 7 to a position where a predetermined elastic force is generated, and the stop ring 12 is fitted on the outer circumference of the through protrusion of the through portion 10 to position the both. , The pressure gear 9 and the crown gear 6 are fixed so that a predetermined pressure force is generated between them. As a result, the two are connected at least to the circumferential force only by the frictional force generated between them and the leaf spring 7, so that the crown gear 6 and the eccentric cam body 8 are connected to each other. When a rotational force in the opposite direction is generated or a rotational blocking force that blocks one rotational force is generated and the rotational force difference exceeds the frictional force, both of them slip. This mechanism corresponds to the power transmission cutoff mechanism in the present invention.

A cam follower 13 is fitted on the cam portion 11 of the eccentric cam body 8. This cam follower 13
Is a box having an inner space of an oval cross section corresponding to the outer diameter of the cam portion 11, and the cam portion 1 is placed in the box.
1 is interpolated. Further, below the cam follower 13, a cylindrical body portion 14 coaxial with the vertical axis of the box body is provided so as to project. A long hole 15 is formed at the center of the oval bottom surface 28 of the cam follower 13 in the short axis direction of the oval cross section, that is, in the direction orthogonal to the long axis of the cam follower 13. The central axis 5 is penetrated through. Further, of the outer peripheral surface of the cylindrical body portion 14, a notch is formed on the lower end side of the outer peripheral surface over a section having a circumferential angle of about 90 ° between the left oblique front side and the right oblique front side in FIG. A recess 16 is formed.

A cylindrical holder 17 is fitted on a cylindrical portion 14 projecting downward from the cam follower 13. The cylindrical portion 14 is provided on the inner peripheral surface of the holder 17.
Of the notch recessed portion 16 and restricts the rotational positions of the cylindrical body portion 14 and the cam follower 13 by the regulating protrusions 18.
Is provided so as to project from the diagonally right front side in FIG. 1 toward the center of the holder 17. In addition, of the outer peripheral surface of the holder 17, FIG.
From the left diagonal front side, that is, from the position orthogonal to the restriction protrusion 18, a swing shaft 19 is provided so as to be bridged between two opposed restriction flanges 30.

On the swing shaft 19, a swing guide protrusion 31 projecting from a support 4 supporting the drive shaft 3 is fitted. The lower end portion of the swing guide protrusion 31 is formed into a bifurcated shape, and the swing shaft 19 is swingably fitted in a fitting recess 32 formed between the bifurcated portions. Further, both end faces in the axial direction of the swing guide protrusion 31 are in close contact with the two opposing regulating flanges 30.

A primary battery, a secondary battery, a solar battery, or the like is used as a power source for driving the motor 1.
Next, the operation of this electric toothbrush will be described. Here, in order to facilitate understanding of the description, the toothbrush body A side direction is defined as the front and the motor 1 side direction is defined as the rear. First, the motor 1
1 is rotated in the direction of arrow a in FIG.
1, the crown gear 6 meshing with the rotation of the pinion 2 is rotated in the direction of arrow b in FIG. 1, and the cam portion 11 of the eccentric cam body 8 integrally attached to the crown gear 6 is rotated. Also rotates in the direction of arrow c in FIG.

However, when the cam portion 11 rotates in the direction of arrow c in FIG. 1, the cam follower 1 fitted in the cam portion 11 is rotated.
A frictional force between the two causes a force to rotate them in the direction of arrow d in FIG. As a result, the cylindrical body portion 14 and the cam follower 13 rotate such that the outer peripheral surface of the cylindrical body portion 14 projecting from the cam follower 13 is along the inner peripheral surface of the holder 17. Due to this rotation, the cylindrical body portion 1
When the regulating protrusion 18 projecting from the inner peripheral surface of the holder 17 comes into contact with the end portion of the notched concave portion 16 formed on the outer peripheral surface of the holder 4 on the right oblique front side in FIG. 1, the cylindrical body portion 14 Also, the rotation of the cam follower 13 is restricted. In this state, the long axis of the long hole 15 formed in the bottom surface of the cam follower 13 is oriented in the front-back direction of the electric toothbrush as shown in FIGS.

As described above, even if the rotational movement of the cam follower 13 is restricted and the elongated hole 15 is oriented in the front-rear direction, the cam portion 11 of the eccentric cam body 8 further performs eccentric rotational movement with respect to the central axis 5. With this eccentric rotation movement, the cam follower 1
3 makes a reciprocating linear motion in a direction restricted by the central shaft 5 and the elongated hole 15, that is, in the front-back direction of the toothbrush. The reciprocating linear motion indicated by the arrow ee in FIG. 1 is transmitted to the support 4 via the holder 17, the regulating flange 30, and the swing guide protrusion 31, so that the drive supported by the support 4 is performed. Axis 3
Moves reciprocally in the front-rear direction, and the toothbrush body A moves in a bath.

On the other hand, when the motor 1 is rotated in the direction of arrow f in FIG. 1, that is, in the direction opposite to the above by reversing the connection electrode of the primary battery, the crown gear 6 also moves in the opposite direction via the pinion 2, That is, the eccentric cam body 8 rotates in the direction of arrow g in FIG. 1, and the cam portion 11 of the eccentric cam body 8 also eccentrically rotates in the direction of arrow h, which is the opposite direction to the above. With the eccentric rotational movement of the cam portion 11, a rotational force in the direction of arrow i is generated in the cam follower 13, so that the outer peripheral surface of the cylindrical body portion 14 follows the inner peripheral surface of the holder 17. Then, the cam follower 13 rotates, and eventually the regulating protrusion 18 comes into contact with the left oblique front end portion of the cutout concave portion 16 in FIG. 1 to stop the rotation of the cam follower 13. In this state, the elongated hole 15 formed on the bottom surface of the cam follower 13 faces in the direction (side) orthogonal to the front-back direction of the toothbrush.

In this way, even if the rotational movement of the cam follower 13 is restricted and the elongated hole 15 is oriented laterally, the cam portion 11 makes an eccentric rotational movement with respect to the central axis 5,
The eccentric rotary motion transmitted to the cam follower 13 is the central axis 5
Is converted into a reciprocating linear motion in a direction regulated by the slot 15 and the lateral direction of the toothbrush. In FIG. 1, an arrow j-
The reciprocating linear motion shown in the j direction is transmitted to the holder 17 and the swing shaft 19. Here, since the drive shaft 3 is restricted from moving in the direction orthogonal to the axis by the bush 22, the reciprocating linear motion of the swing shaft 19 in the direction of arrow j-j causes the swing shaft 19 to swing. Through the motion of sliding up and down along the fitting recess 32 of the guide protrusion 31, it is converted into a reciprocating rotary motion in the direction of the arrow kk about the axis of the drive shaft 3, that is, a reciprocating oscillating motion. As the drive shaft 3 reciprocally swings, the toothbrush body A makes a rolling motion.

However, when a strong load is applied to the toothbrush body A by strongly pressing the toothbrush body A against the teeth or gums during the bass-rolling motion of the toothbrush body A, the drive shaft 3 swings. A force acts to prevent the dynamic movement or the reciprocating linear movement. The cam follower 13
In order to prevent the reciprocating linear movement of the eccentric cam body 8, the eccentric rotational movement of the cam portion 11 of the eccentric cam body 8 is suppressed, and the force for suppressing the rotation of the crown gear 6 acts. When this rotation restraining force becomes larger than the frictional force between the eccentric cam body 8 and the crown gear 6 by the leaf spring 7, both of them slip and the crown gear 6 idles, thereby transmitting power from the motor 1 to the drive shaft 3. The power transmission of the path is cut off. On the other hand, when the load applied to the toothbrush body A becomes small, the rotation suppressing force for suppressing the eccentric rotational movement of the cam portion 11 of the eccentric cam body 8 becomes small and the friction between the crown gear 6 and the eccentric cam body 8 by the leaf spring 7 again. The force becomes larger than the rotation restraining force, the two rotate together, and the toothbrush body A resumes the bass-rolling motion.

The power transmission cutoff mechanism of this embodiment can be easily replaced by a friction clutch or the like, and a structure other than the structure for transmitting power by friction force can be easily adopted. In short, if the toothbrush body is overloaded, any structure can be adopted as long as the movement of the toothbrush body is stopped in the power transmission path from the motor to the toothbrush body.

In the above embodiment, the toothbrush body is a bath.
Although only the electric toothbrush that makes a rolling motion has been described in detail, the electric toothbrush of the present invention can be expanded to any device that transmits a desired motion to the toothbrush body by converting the rotational motion of the motor.

[0023]

As described above, according to the electric toothbrush of the present invention, the power transmission cutoff mechanism provided in the power transmission path between the motor and the drive shaft strongly presses the toothbrush body against the teeth or gums. If an overload, which is more than the load that adversely affects them, is applied as a reaction force to the toothbrush body, the transmission of power can be blocked and damage to the teeth and gums can be prevented. Therefore, the structure should be simplified. It is possible to suppress the cost increase, and it is easy to put into practical use.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a power transmission path showing an embodiment of an electric toothbrush of the present invention.

FIG. 2 is a vertical cross-sectional view showing the internal structure of the electric toothbrush of FIG.

[Explanation of symbols]

 1 is a motor 2 is a pinion 3 is a drive shaft 4 is a support body 5 is a central shaft 6 is a crown gear 7 is a leaf spring 8 is an eccentric cam body 9 is a pressing portion 10 is a penetrating portion 11 is a cam portion 12 is a stop ring 13 is a cam follower 14 is a cylindrical body portion 15 is a long hole 16 is a notched concave portion 17 is a holder 18 is a regulating protrusion 19 is a swing axis A is a toothbrush body

Claims (1)

[Claims] 1. A drive shaft which is connected to a motor and a toothbrush body and is rotatable or movable according to a desired movement of the toothbrush body, and a rotational movement of the motor according to a desired movement of the toothbrush body. An electric toothbrush provided with a motion converting mechanism for converting into a rotary motion or a moving motion, the power transmission for interrupting the power transmission in the power transmission path between the motor and the drive shaft according to an overload applied to the toothbrush body. An electric toothbrush having a blocking mechanism.