GB2366995A

GB2366995A - A power toothbrush neck

Info

Publication number: GB2366995A
Application number: GB0023493A
Authority: GB
Inventors: Ka Nam Ho
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-09-25
Filing date: 2000-09-25
Publication date: 2002-03-27
Anticipated expiration: 2020-09-25
Also published as: GB2366995B8; GB2366995A8; GB2366995B; GB0023493D0

Abstract

A neck 5 for a powered toothbrush comprises an elongate substantially rigid spindle housing 6 surrounding an elongate rotatable spindle 8 having a first end rotatable about a first axis of rotation and a second end rotatable about a second axis of rotation wherein the two axes of rotation are not collinear. Preferably the spindle is flexible, may be made of a plastic material such as nylon and lies along the central axis of the curved spindle housing. A universal joint may link the two spindle ends adjacent a bend in the spindle housing. Guides 10 may be provided which protrude inwardly from the spindle housing to form bearing surfaces and define an opening through which the spindle passes. Preferably one end of the spindle terminates in a bulb 12 received in a groove in the brush head (20, Fig 4) and which rotates during operation. Advantageously the curved neck of the toothbrush allows effective cleaning of the teeth.

Description

"A Powered Toothbrush" THIS INVENTION relates to powered toothbrushes, and more particularly to toothbrushes or plaque removers with moveable bristles powered by a motor.

Powered toothbrushes, particularly toothbrushes powered by electric motors, have become increasingly common in recent years. The bristles of such a toothbrush oscillate rapidly, so that a user simply presses the bristles against his or her teeth, which are cleaned by the motion of the bristles. This reduces the effort and dexterity required in brushing one's teeth. Electric toothbrushes are particularly useful for elderly or disabled people.

Many people find that, due to the shape of the human jaw, it is difficult to brush all of one's teeth (and particularly one's molar teeth) effectively using a toothbrush with a straight neck. In order to alleviate this problem, many conventional, non-powered toothbrushes are now provided with one or more bends in the necks thereof, to allow a user of such a toothbrush to brush all of his or her teeth easily and effectively.

Powered toothbrushes generally comprise a base, having an electric motor therein, and a head having a face on which bristles are mounted. A straight neck extends between the base and the head. A spindle, typically of steel or another similarly rigid material, is contained in the neck and is connected to the motor in the base of the toothbrush such that the motor, when activated, rotates the spindle. The spindle is connected to the head in such a way that rotation of the spindle causes the desired oscillatory motion of the face on which the bristles are mounted.

This arrangement is unsuited to the incorporation of a bend in the neck of the powered toothbrush.

It is an object of the present invention to combine the convenience of a powered toothbrush with the advantages of providing a bend in the neck of a toothbrush.

Accordingly, the present invention provides a neck for a powered toothbrush comprising: an elongate and substantially rigid spindle housing having a curved portion; and an elongate spindle substantially surrounded by the spindle housing and rotatable therein, the spindle having a first end rotatable about a first axis of rotation and a second end rotatable about a second axis of rotation, the two axes of rotation not being collinear. Advantageously, the axes or rotation of the first and second ends of the

spindle subtend an angle of at least 10'to 150.

Preferably, the spindle is a flexible spindle.

Conveniently, at least a portion of the spindle describes a curve, the spindle being rotatable while so curved.

Advantageously, the radius of curvature of the curved portion of the spindle is between 200mm and 500mm.

Preferably, the radius of curvature of the curved portion of the spindle is approximately 250mm. Conveniently, at least a portion of the spindle housing describes a curve.

Advantageously, the radius of curvature of the spindle housing is substantially the same as the radius of curvature of the spindle.

Preferably, the two ends of the spindle are linked to one another by a universal joint. Conveniently, the spindle housing has a bend therein.

Advantageously, the bend in the spindle housing is located adjacent the universal joint.

Preferably, a plurality of joints are interposed between the two ends of the spindle.

Conveniently, at least one end of the spindle is rotationally mounted on the spindle housing.

Advantageously, the neck further comprises at least one guide protruding inwardly from an inner surface of the spindle housing and providing an aperture through which the spindle passes.

Preferably, the at least one guide is provided near one end of the spindle housing.

Another aspect of the present invention provides a neck according to the above in combination with a brush head.

Conveniently, a portion of the spindle engages with a portion of the brush head, wherein rotation of the spindle causes motion of the brush head.

Advantageously, rotation of the spindle causes oscillatory motion of the brush head.

Preferably, the portion of the spindle comprises an off-axis portion at an end thereof, and the brush head comprises an elongate groove, the off-axis portion being received in the elongate groove.

A further aspect of the present invention provides a toothbrush comprising a neck and brush head according to the above, attached to a base.

Conveniently, the neck and brush head are removably attached to the base.

Advantageously, the neck is attached to the base at a first end thereof and attached to the brush head at a second end thereof.

Preferably, the base comprises a motor and drive shaft, the drive shaft being rotationally coupled to the spindle. Conveniently, the base comprises a handle of the toothbrush.

In order that the present invention may be more readily understood, embodiments thereof will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a cross-sectional side view of a part of a base of a toothbrush embodying the present invention; Figure 2 is a cross-sectional side view of the components of a toothbrush neck embodying the present invention, a central spindle being shown in elevation; Figure 3 is a cross-sectional side view of the components of a brush head embodying the present invention; Figure 4 is a cross-sectional side view of the brush head of Figure 3 fixed to the toothbrush neck of Figure 2; Figure 5 is a cross-sectional side view of the brush head and toothbrush neck of Figure 4 in combination with the base of Figure 1; and Figure 6 is a plan view an upper part of the toothbrush neck of Figure 2 in a first configuration in combination with the brush head of Figure 3.

Figure 7 shows a second configuration of the components of Figure 6; and Figure 8 shows a third configuration of the components of Figure 6.

Turning to Figure 1, an upper portion of an elongate and substantially cylindrical base 1 of a toothbrush embodying the present invention is shown, in which a battery (not shown) and electric motor 2 are housed. The base 1 is shaped so that it may be comfortably held by a user during use of the toothbrush, and acts as the handle of the toothbrush. The lower portion of the base which is not shown has a flat end to enable the base to be stood upright on a flat surface. Additionally, the battery within the base may be a rechargeable battery, the base being connectable to a recharging unit.

The motor 2 is provided with a drive shaft 3, which is rotatably drivable by the motor 2 and which extends away from the motor 2 along a central longitudinal axis of the base 1. The drive shaft 3 projects out of the upper portion of the base 1. The exposed end of the drive shaft 3 carries a rounded rubber head 4.

Figure 2 shows a toothbrush neck 5 embodying the present invention.

The neck 5 comprises an elongate hollow spindle housing 6, a proximal end 7 thereof being open. The spindle housing 6 describes a curve, the radius of the curve being between 200mm and 500mm.

An elongate spindle 8 is located within the spindle housing 6, the spindle also being curved to the same extent as the spindle housing 6, i. e. with a radius of curvature of between 200mm and 500mm so as to follow the curvature of the spindle housing. In a preferred embodiment of the invention, the radius of curvature of the spindle is 250mm. The spindle 8 lies along the central axis of the spindle housing 6. Both ends of the spindle 8 are held within the spindle housing 6 by bearing surfaces which enable the spindle 8 to rotate with respect to the spindle housing 6. The rotational mounting of the spindle at either end thereof facilitates the positioning of the spindle 8 along the central axis of the spindle housing 6, the curvature of the spindle following that of the spindle housing 6. The rubber head 4 has a slightly larger diameter than the interior of the socket 9. An elongate cylindrical socket is formed at a proximal end of the spindle 8. The longitudinal axis of the socket 9 is collinear with the longitudinal axis of the spindle 8. The interior of the socket 9 is cylindrical and of similar shape to the rubber head 4 on the drive shaft 3.

Near to a distal end of the neck 5, guides 10 protrude inwardly from the spindle housing 6 to form bearing surfaces and to define an opening 11 through which the spindle 8 passes. The opening 11 lies on the central axis of the spindle housing 6. The spindle 8 terminates, at a distal end thereof which protrudes beyond the guides 10, in an enlarged bulb 12 of the spindle 8.

Referring now to Figures 6 to 8, the spindle 8 terminates at the distal end thereof in the bulb 12 which is asymmetric about the longitudinal axis of the spindle. The outer surface of the bulb 12 provides a cam surface and is received in an elongate groove in a brush head as described below to cause the bulb 31 to perform a circular motion and hence result in an oscillatory rotational motion of the brush head 20. The bulb 12 is an off-axis with respect to the central axis of the spindle 8.

The movement of the groove 28 from side to side in this manner causes the cylindrical body 21 of the brush head 20 to perform an oscillating rotational motion about the pin 24, hence providing the movement of the brushes 22 necessary to clean a user's teeth.

The spindle housing 6 terminates at the distal end thereof in a head 15 of the neck 5. The head 15 comprises a mating face 16 that is adapted to have a brush-carrying portion attached thereto, as will be described below.

The mating face 16 of the head 15 has a circular bore 17 therein, the bore 17 comprising an inner portion 18 having a first radius and an outer portion 19 having a second radius, the second radius being greater than the first radius. The bore 17 is located beyond the distal end of the spindle 8.

Turning to Figure 3, a brush head 20 for use with the present invention comprises a substantially cylindrical body 21 having a plurality of brushes 22 mounted on a front surface 23 thereof. In a preferred embodiment of the invention, the brushes 22 are arranged in an inner ring of brushes 22, close to the centre of the front surface 23 of the cylindrical body, and an outer ring of brushes 22, close to the edge of the front surface 23. However, a skilled person will realise that any appropriate arrangement of brushes may be made on the front surface 23 of the cylindrical body 21.

A pin 24 is inserted and firmly retained in a hole 25 in a rear surface 26 of the cylindrical body 21, the hole 25 being located at the axis of symmetry of the cylindrical body 24. Around a portion of the shaft of the pin 24 that protrudes outside the cylindrical body 21, a pin bearing 26 is provided, the pin bearing 26 being freely rotatable with respect to the pin 24. The pin bearing 26 is held in place by a head 27 of the pin 24, which is substantially wider than the shaft thereof and wider than the hole in the pin bearing 26 through which the shaft of the pin 24 passes.

At one edge of the cylindrical body 21 of the brush head 20, an elongate groove 28 is provided, being elongate in a direction parallel with the axis of symmetry of the cylindrical body 21, the groove 28 protruding past the rear surface 26 of the cylindrical body 21.

The brush head 20 is attached to the neck 5 as seen in Figure 4. The pin bearing 26 is received with an interference fit in the outer portion 19 of the bore 17. In this manner, the brush head 20 is freely rotatable with respect to the neck 5 about the pin bearing 26. When the neck 5 and brush head 20 are connected to one another, the bulb 12 of the spindle 8 is received in the elongate groove 28 provided on the brush head 20.

Figure 5 shows the neck 5 and brush head 20, connected together as described above and attached to the base 1 to form a toothbrush 29 embodying the present invention. The drive shaft 3 of the base 1 passes through the open, proximal end 7 of the neck 5, and the enlarged rubber head 4 on the drive shaft 3 is received in the socket 9 at the proximal end of the spindle 8. Due to the interference fit between the rubber head 4 on the drive shaft 3 and the socket 9 in the spindle 8 there is sufficient friction between these components to ensure that rotation of the drive shaft 3 causes rotation of the spindle 8.

The open end 7 of the neck 5 fits over the upper part of the base 1 and snap fits thereon by virtue of a pin 30 provided on the inner surface of the open end 7. The pin 30 is received in an indent on an outer surface of the base 1. A person of ordinary skill in the art will immediately realise that the present invention is not limited to this precise method of attachment. In particular, the neck 5 may be attached to the base 1 such that the two components are easily detachable from one another. This feature is particularly useful if the neck 5 and the brush head 20 are to be sold separately with replacement neck 5 being sold to replace worn out or broken brush heads 20.

In operation of the toothbrush 1, a switch (not shown) on the base is pressed to activate the motor 2 in the base 1. This drives the drive shaft 3 rotationally. As described above, this movement causes rotational movement of the spindle 8. The spindle 8 is formed from a flexible material so that the spindle 8 is able to rotate about the longitudinal axis thereof whilst maintaining alignment with the curvature of the spindle housing 6. A suitable material from which the spindle 8 might be made is a plastic, such as nylon.

As the spindle 8 rotates, the asymmetric bulb 12 thereof describes an eccentric circular motion. Since the elongate groove 28 is elongate in the direction parallel to the axis of symmetry of the cylindrical body 21 of the brush head 21, movement of the off-axis portion 12 of the spindle 8 in this direction does not cause movement of the groove. However, movement of the off-axis portion 8 of the spindle 8 in a direction perpendicular to this (i. e. parallel with the front surface 23 of the brush head 20) causes the groove 28 to move from side to side.

Figures 6 to 8 show how, as the spindle 8 rotates, how the eccentric motion of the bulb 12 in a direction parallel to the front surface 23 of the brush head 20 causes the brush head 20 to perform a reciprocating oscillatory motion.

Arrows on Figures 6 to 8 show the direction of motion of both the spindle 8 and the brush head 20.

It will be clear to a person skilled in the art that other cam devices in addition to the bulb 12 would be appropriate for converting the rotational motion of the spindle into a useful tooth-cleaning motion of the brush head 20 in a toothbrush embodying the present invention.

The curve provided in the spindle housing 6 of the neck 5 reduces the effort required by the user to clean all of his or her teeth effectively. It will be clear to a person skilled in the art that the present invention provides a toothbrush that combines the efficiency and convenience of powered toothbrushes with the advantages of a toothbrush with a curved neck thereby allowing a uniquely simple and thorough cleaning of teeth and/or removal of plaque.

It will be clear to a person of ordinary skill in the art that the present invention is not limited to the abovedescribed embodiment, and that any method of transmitting rotational movement through an angle may be used to put the present invention into effect. For example, it is envisaged that the spindle may have a universal joint disposed between the ends thereof, so that the spindle describes an angle at one point along the length thereof but is otherwise substantially straight. More than one universal joint may be provided, so that the toothbrush neck may contain as many bends as are required.

In the present specification"comprises"means"includes or consists of and"comprising"means"including or consisting of.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

CLAIMS 1. A neck for a powered toothbrush comprising: an elongate and substantially rigid spindle housing; and an elongate spindle substantially surrounded by the spindle housing and rotatable therein, the spindle having a first end rotatable about a first axis of rotation and a second end rotatable about a second axis of rotation, the two axes of rotation not being collinear.
2. A neck according to Claim 1, wherein the axes or rotation of the first and second ends of the spindle subtend an angle of at least 10'to 15'.
3. A neck according to Claim 1 or 2, wherein the spindle is a flexible spindle.
4. A neck according to Claim 3, wherein at least a portion of the spindle describes a curve, the spindle being rotatable while so curved.
5. A neck according to Claim 4, wherein the radius of curvature of the curved portion of the spindle is between 200mm and 500mm.
6. A neck according to Claim 5, wherein the radius of curvature of the curved portion of the spindle is approximately 250mm.
7. A neck according to any of Claims 4 to 6, wherein at least a portion of the spindle housing describes a curve.
8. A neck according to Claim 7, wherein the radius of curvature of the spindle housing is substantially the same as the radius of curvature of the spindle.
9. A neck according to Claim 1 or 2, wherein the two ends of the spindle are linked to one another by a universal joint.
10. A neck according to Claim 9, wherein the spindle housing has a bend therein.
11. A neck according to Claim 11, wherein the bend in the spindle housing is located adjacent the universal joint.
12. A neck according to any one of Claims 9 to 11, wherein a plurality of universal joints are interposed between the two ends of the spindle.
13. A neck according to any preceding claim, wherein at least one end of the spindle is rotationally mounted on the spindle housing.
14. A neck according to any preceding claim, further comprising at least one guide protruding inwardly from an inner surface of the spindle housing and providing an aperture through which the spindle passes.
15. A neck according to Claim 14, wherein the at least one guide is provided near one end of the spindle housing.
16. A neck according to any preceding claim in combination with a brush head.
17. A neck and brush head according to Claim 16, wherein a portion of the spindle engages with a portion of the brush head, wherein rotation of the spindle causes motion of the brush head.
18. A neck and brush head according to Claim 17, wherein rotation of the spindle causes oscillatory motion of the brush head.
19. A neck and brush head according to Claim 17 or 18, wherein: the portion of the spindle comprises an off-axis portion at an end thereof ; and the brush head comprises an elongate groove, the off-axis portion being received in the elongate groove.
20. A toothbrush comprising a neck and brush head according to any one of Claims 16 to 19, attached to a base.
21. A toothbrush according to Claim 20, wherein the neck and brush head are removably attached to the base.
22. A toothbrush according to Claim 20 or 21, wherein the neck is attached to the base at a first end thereof and attached to the brush head at a second end thereof.
23. A toothbrush according to any one of Claims 20 to 22, wherein the base comprises a motor and drive shaft, the drive shaft being rotationally coupled to the spindle.
24. A toothbrush according to any one of Claims 20 to 23, wherein the base comprises a handle of the toothbrush.
25. A neck substantially as hereinbefore described, with reference to accompanying Figures 2 and 4 to 8.
26. A toothbrush substantially as hereinbefore described, with reference to accompanying Figure 5.
27. Any novel feature or combination of features disclosed herein.