GB2332366A

GB2332366A - Toothbrush

Info

Publication number: GB2332366A
Application number: GB9727086A
Authority: GB
Inventors: Malcolm Webber; Brian Wilson; William Jackson
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-12-22
Filing date: 1997-12-22
Publication date: 1999-06-23
Also published as: GB9802351D0; GB2332366A9; GB9727086D0; GB2332617A

Abstract

A toothbrush 1 for mounting on a finger includes a grip portion 3 comprising an engagement aperture 5 for engaging a pad of a finger and a saddle section 7 wrapping around the finger behind the first finger joint. The brush of the toothbrush is mounted ahead of the tip of the finger on an arm 4 connected to the grip portion 3.

Description

2332366 TOOTHBRUSH This invention relates to a toothbrush suitable for

mounting on a finger.

A recognised problem in the f ield of dental hygiene is the problem that most people do not clean their teeth properly. It is well known that ineffectively cleaned teeth are a common course of tooth decay and gum disease while improper teeth cleaning can result in physical damage to and erosion of the gums causing sensitive teeth and, again, potentially leading to gum disease.

One approach to improving the quality of teeth cleaning has been to provide new designs of toothbrush which will make proper cleaning easier and reduce the tendency to employ improper cleaning techniques.

It has been proposed that a toothbrush could be mounted on the end of a f inger instead of being mounted on a handle. A typical proposed finger mounted toothbrush is illustrated in figure 7. This comprises a substantially cylindrical hollow gripping member 20 on which a brush 21 is mounted. In use, a finger is pushed into the gripping member 20 until the compression of the finger inside the grip member 20 generates sufficient friction to hold the toothbrush in place. The finger is then manipulated to use the brush 21 to clean the teeth.

Toothbrushes of this finger mounted type suffer from a number of problems. Firstly,' the amount of compression of the finger inside the gripping element 20 required to hold the toothbrush in place is large and as a result toothbrushes of this type are uncomfortable to use. Further, in practice it is difficult to comfortably manoeuvre the finger mounted toothbrush inside the users mouth to clean all of the teeth.

The present invention is intended to provide a finger mounted toothbrush overcoming these problems, at least in part.

This invention provides a toothbrush comprising a grip portion suitable for fitting around a finger and a brush portion attached to the grip portion, in which the brush portion is located such that when the grip portion is fitted around a finger the brush portion lies beyond the finger tip.

This provides the advantage that because the brush element lies beyond the finger tip, when using toothbrush it is not necessarily to place both the brush element and the finger one behind the other adjacent to the teeth, as is necessary with known finger mounted toothbrushes. This makes using the toothbrush simpler and more convenient because the clearance required between the upper and lower teeth and between the teeth and the soft mouth parts is reduced. This is because only the brush element or the finger needs to move between the upper sets of teeth or the teeth and soft mouth parts at any one location instead of both the finger and the brush element having to be accommodated together at the same location.

Preferably, the grip portion comprises an engagement section suitable for engaging the pad of the finger and a plurality of surfaces located relative to the engagement section such that when a pad of the finger is engaged in the engagement section respective contact surfaces can contact the back and sides of the finger at or behind the first finger joint. This allows the location of and forces applied through the toothbrush to be controlled by articulation of the second finger joint, giving better control of the movement of and forces applied through the toothbrush.

Preferably, the plurality of contact surfaces are provided by the interior of a saddle section arranged to pass around a finger engaged by the engagement section at or behind the first finger joint.

- 2 i Advantageously, the engagement section comprises an aperture passing through the grip portion and the aperture has a bevelled edge.

Preferably the saddle section is broken by a slot extending from the engagement aperture to the end of the saddle section.

Preferably the saddle section is a tube having a circular cross section and tapering towards the brush portion.

Preferably an abutment surface is provided adjacent to the engagement section, the abutment surface being located such that when a pad of a finger is engaged in the engagement section the tip of the finger can bear against the abutment section.

Preferably, the brush portion is attached to the grip portion by an arm.

Preferred embodiments of the invention will now be described, by way of example only, with reference to the accompanying diagrammatic figures, in which:

Figures la and lb show perspective views of a toothbrush according to a first embodiment of the invention from above and below respectively; Figure 2 shows a side view of the tooth brush of f igures 1; Figure 3a and 3b show perspective views of a grip portion of the toothbrush of figures 1 from above and below respectively; Figure 4 shows a top plan view of the toothbrush of figures 1; Figure 5 shows a longitudinal cross sectional side view of a second embodiment of a toothbrush according to the invention; Figure 6 shows a longitudinal cross sectional perspective view of the toothbrush of figure S; and, Figure 7 shows a cross section through a known toothbrush.

- 3 A tooth brush according to a first embodiment of the invention will be described with reference to figures 1 to 4.

A f inger mounted toothbrush 1 according to a first embodiment of the invention comprises a brush portion 2 and a grip portion 3 linked by a support arm 4.

The grip portion 3 is formed by a cylindrical hollow tube having a diameter sufficient to allow a finger to fit within and be gripped by the grip portion 3 without the finger being uncomfortably squeezed by the grip portion 3. In the lower surface of the grip portion 3 an aperture 5 is formed having a levelled rim 6. The aperture 5 is oval in shape having its long axis parallel to the longitudinal direction of the support arm 4.

The aperture 5 is sized to engage the pad of a finger to locate the toothbrush 1 on the users finger in use.

Behind the finger pad engaging aperture 5 the grip portion 3 comprises a saddle section 7 formed by a tube circular in cross section and broken by a slot section 8 linking the engagement aperture 5 to the end of the tubular saddle section 7. As a result of the slot section 8 the broken loop formed by the saddle section 7 acts as a circular spring. The tube forming the saddle section 7 is slightly tapering, getting narrower towards the brush portion 2 and support arm 4. The support arm 4 extends out from the grip portion 3 and supports the brush portion 2.

The use of a slot section 8 allows the toothbrush 1 to be used with a wider range of finger sizes and helps to prevent the toothbrush 1 becoming stuck if a too large finger is forced into it.

When the toothbrush is placed on a finger, the saddle section 7 passes around the finger at or behind the first finger joint. The saddle section 7 then acts as a circular spring to grip the user's finger holding the - 4 1:

toothbrush 1 on the user's finger.

The brush portion 2 comprises a large number of bristles 9 embedded in and supported by a rigid backing and support plate 10, as is conventional in the field of toothbrushes.

Where the grip portion 3 is connected to the support arm 4, the bevelled rim 6 of the aperture 5 is continued upwards from the aperture 5 to form a sloping abutment surface 11 which contacts the finger tip of a finger placed within the grip portion 3.

In order to use the toothbrush 1 the user 1 s finger is inserted into the grip portion 3 until the pad of the finger is engaged by the aperture 5 and the tip of the finger is in contact with the abutment surface 11. The size of the grip portion 3 relative to the user's finger should be such that the saddle section 7 of the grip portion 3 will compress the users finger slightly. The provision of the slot 8 breaking the saddle section 7 so that it does not form a full circular tube allows the saddle section 7 to act as a circular spring and allows the sides of the saddle section 7 to be easily spread apart by the user's finger when inserted so that even when the user's finger is larger than the internal size of the saddle section 7 the force required to insert the user's finger into the grip portion 3 of the toothbrush and the resulting pressure on the users finger will not be sufficient to cause discomfort.

It is not essential that the user's finger be large enough that it is gripped by the saddle section 7. However, this is advantageous because it allows the toothbrush 1 to stay on the user's finger when not actually cleaning the user's teeth without any effort or attention from the user.

When the toothbrush 1 is used, vertical forces acting on the toothbrush 1 through the face of the brush element 9 in the direction of the arrow A in f igure 2, - such as those produced by pressing the brush element against the user's teeth to clean them, will be transmitted back along the support arm 4 and will cause the toothbrush to pivot around the pad of the user,s f inger engaged with the aperture 5 to bring the top of the saddle section 7 into contact with the back of the user's finger at or behind the first finger joint.

Similarly, lateral forces acting on the toothbrush 1 through the brush element 9 in the directions of the arrows B in figure 4 will be transmitted along the support arm 4 and will pivot the toothbrush 1 around the pad of the user's finger where it is engaged in the aperture 5 and urge a respective one of the sides of the saddle portion 7 against a respective side of the user's finger at or behind the first finger joint.

In the case of vertical or lateral forces, the saddle 7 will be urged against the user's finger. Depending upon the size of the users finger this may cause the toothbrush 1 to pivot to bring the saddle section 7 into contact with the users finger or the saddle section 7 may already be in contact with the users finger.

Longitudinal forces acting on the toothbrush 1 through the brush element 9 in the directions of the arrows C in f igure 4 will be transmitted along the support arm 4 to the grip portion 2 and will be absorbed by friction due to the engagement of the pad of the user's finger in the aperture 5 and by friction between the top of the saddle section 7 and the back of the user's finger. Further, where the user's finger is large enough to entirely fill the saddle section 7, or where longitudinal and lateral forces are acting on the toothbrush 1 simultaneously, longitudinal forces will also be absorbed by friction between the or both sides of the saddle section 7 and the corresponding sides of the user's finger. Finally, longitudinal forces acting on the toothbrush 1 to urge it towards the users finger will also 1 be resisted by the sloping abutment surface 11 bearing against the user's finger tip.

If the longitudinal forces acting on the toothbrush 1 aresufficient to cause the toothbrush 1 to move relative the user's finger, the frictional forces holding the toothbrush in place on the user's finger can be increased by flexing the first finger joint, bracing the user's finger between the surface 6 around the engagement aperture 5 and the top of the saddle section 7. In practice, it has been found that such a flexing action is automatic if longitudinal movement of the toothbrush is felt.

Thus, all of the forces acting on the toothbrush 1 while cleaning the teeth are transmitted to and absorbed by the users finger, thus ensuring full control of the toothbrush 1 to allow effective teeth cleaning.

As explained above, longitudinal movement of the toothbrush 1 relative to the user's finger is primarily resisted by frictional forces between the saddle section 7 and the user's finger and by the engagement of the pad of the user's finger in the aperture 5. Although longitudinal movement of the toothbrush 1 towards the user 1 s f inger can also be resisted by the abutment surf ace 11 bearing against the tip of the user's finger the primary purpose of the abutment surface 11 is to prevent the user 1 s f inger being inserted too f ar into the grip portion and to ensure that the user's finger is properly located to allow engagement of the pad of the user's finger in the aperture 5.

The location of the brush portion 2 separated from the grip portion 3 by the support arm 4 so that the brush portion 2 lies beyond the user's finger tip instead of being placed adjacent and parallel to the user 1 s f inger as in the prior art reduces the amount of clearance required by the brush portion 2 to clean the teeth. Since providing such clearance for brushing requires the user to - 7 1 1 open their mouth to provide sufficient clearance between the lower and upper sets of teeth and to move the sof t mouth parts to provide sufficient clearance between the teeth and the sof t mouth parts, ease and comfort of use are greatly improved by the reduction in required clearance.

The precision with which the brush element 9 can be positioned and the degree of control over the forces applied through the brush element 9 during brushing are both improved by making the support arm 4 as short as possible. The support arm 4 could even by eliminated and the brush portion 2 mounted directly in the end of the grip portion 3. However, it is preferred that the length of the support arm 4 be sufficient to allow the user's teeth to be cleaned without the user's finger actually having to be placed inside the users mouth. This reduces the clearances required for teeth cleaning because the support arm portion 4 is thinner than the user's finger. Further, it is desirable that it should be unnecessary for the user to place their finger inside their mouth because some people are unhappy with the idea of placing their fingers in their mouths while cleaning their teeth.

The toothbrush 1 is supported and manipulated by a single finger and as a result the movement of and forces applied to the brush element 9 while cleaning teeth can be more accurately controlled than with a toothbrush having a handle grip for the whole hand. In particular, the tendency to apply excessive force through the brush element 9 to the teeth, which excessive force can cause damage to the teeth and gums, is greatly reduced by the toothbrush 1 being mounted on and manipulated by a single finger rather than the entire hand.

The saddle section 7 of the grip portion 3 of the toothbrush 1 straddles the first finger joint so that the location and forces applied to the toothbrush are controlled by articulation of the second finger joint 8 while the first joint can flex within the grip portion 3 allowing for improved user comfort and finer control of the movement of and forces applied to the brush element 9.

Figures 5 and 6 show a cut away side view and cut away perspective view respectively of a second embodiment of the toothbrush according to the invention. The toothbrush according to the second embodiment has a longer support arm 4 and a longer saddle section 7 than the first embodiment. Otherwise this design is similar to the figures first embodiment.

The use of a longer support arm 4 and saddle section 7 increases the range of user finger lengths and mouth sizes for which the toothbrush 12 can conveniently be used. However, the lengthening of the support arm portion 4 will reduce the precision with which the position of and forces exerted through the brush element 9 can be controlled.

In both embodiments of the toothbrush 1 and 12, the grip portion 3 is cut away ahead of the saddle section 7 to expose the top of the user's finger tip. The main advantage of cutting away the back of the grip portion 3 is to reduce the clearance required to use the toothbrush and to ensure that all surfaces of the toothbrush which are moved in and out of the mouth in use are gently sloped to avoid injury to the user's lips or unpleasant jarring impact with the user's teeth. Cutting away of the back of thee grip portion 3 also reduces the weight of the toothbrush and eases freeing of a trapped finger if the toothbrush should be forced over a finger which is too large. However, the use of a cut away portion is not essential.

In the illustrated examples, the support arm 4 is a simple longitudinal member. Alternatively, the support arm 4 could include a convoluted portion to limit the amount of load which could be applied to the users teeth through the brush element 9. Such convoluted brush 9 support elements toothbrushes.

are well known in the field of

In the illustrated examples the support arm 4 is substantially straight and the brush portion 2 is substantially parallel to the end of the user's finger. This is not essential. If preferred, the support arm 4 could be formed in a curved or double curved shape to vary the position of the brush portion 2 relative to the grip portion 3 and/or the brush portion 2 could be placed at an angle to the end of the user's finger.

In the illustrated examples the saddle section 7 is circular in cross section. This is convenient. However, it may be preferred to make the saddle section 7 elliptical in cross section, the long axis of the ellipse being vertical. This improves control and user comfort by causing the user's finger to be gripped more tightly laterally between the sides of the saddle section 7 than vertically between the top and bottom of the saddle section 7. This would allow the gripping of the user's f inger between the sides of the saddle section 7 to be increased without increasing the overall degree of squeezing of the user's finger to uncomfortable levels. The increased clearance around the user's finger between the top and bottom of the saddle section 7 can be compensated for by flexing of the first finger joint.

In the illustrated examples the grip portion 3 has an essentially constant wall thickness. This is not essential and the wall thickness could be varied from point to point across the grip portion 3 in order to control the flexing of the toothbrush and increase the range of finger sizes which can comfortably be accommodated.

In the illustrated embodiment the pad of the user's finger is engaged by an engaging surface formed as a bevelled rim 6 of an aperture 5. This is not essential and the aperture 5 could be replaced by a recess or other internal profiling of the grip portion 3 to provide a finger pad engaging surface. However, the use of an aperture edge to form the finger engaging surface allows the toothbrush to be used with a wide range of f inger sizes and shapes.

The illustrated embodiments can be integrally formed from a single plastics material by injection moulding. Alternatively, different parts of the toothbrush could be made of different plastics materials having different properties to improve user comfort and control. Further, the toothbrush could be made in two parts having a brush portion separate from the rest of the toothbrush. This allows a user to buy a toothbrush body having a grip portion closely matching the user's finger size, which could be used indefinitely, and to replace the brush portion as the brushes wore out. This would make it economically feasible to make the grip portions in a much wider range of sizes than would be practical if the entire toothbrush was unitary and was intended to be disposed of and replaced when the brush wore out.

In the illustrated examples the grip portion is a partial tube widening slightly from the aperture 5 back towards the saddle section 7. This gradual widening matches the general profile of the user's finger and helps to prevent an excessively large finger becoming stuck. However, this is not essential.

The toothbrush could incorporate a toothbrush dispenser supplying toothbrush to the brush element 9.

The illustrated embodiments are examples of the invention only and it will be understood by the person skilled in the art that variations are possible.

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Claims

1. A toothbrush comprising a grip portion suitable for fitting around a finger and a brush portion attached to the grip portion, in which the brush portion is located such that when the grip portion is fitted around a finger the brush portion lies beyond the finger tip.

2. A toothbrush as claimed in claim 1 in which the grip portion comprises an engagement section suitable for engaging the pad of a finger and a plurality of contact surfaces located relative to the engagement section such that respective contact surfaces can contact the back and sides of the finger at or behind the first finger joint.

3. A toothbrush as claimed in claim 2, in which the plurality of contact surfaces are provided by the interior of a saddle section arranged to pass around a finger engaged by the engagement section at or behind the first finger joint.

4. A toothbrush as claimed in claim 2 or claim 3 in which the engagement section comprises an engagement aperture passing through the grip portion.

5. A toothbrush as claimed in claim 4, in which the aperture has a bevelled edge.

6. A toothbrush as claimed in any one of claims 3 to 5, in which the saddle section is broken by a slot.

7. A toothbrush as claimed in claim 6, when dependent on claim 4 or claim 5, in which the slot extends f rom the engagement aperture to an end of the saddle section.

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8. A toothbrush as claimed in any one of claims 3 to 7, in which the saddle section is a tube having a circular cross section and tapering towards the brush portion.

9. A toothbrush as claimed in any one of claims 2 to 8, in which an abutment surface is provided adjacent the engagement section, the abutment surface being located such that when a pad of a finger is engaged in the engagement section the tip of the finger can bear against the abutment surface.

10. A toothbrush as claimed in any preceding claim, in which the brush portion is attached to the grip portion by an arm.

11. A toothbrush substantially as shown in or as described with reference to figures 1 to 4 ofthe accompanying drawings.

12. A toothbrush substantially as shown in or as described with reference to figures 5 and 6 ofthe accompanying drawings.

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