WO1998038889A2

WO1998038889A2 - Toothbrush

Info

Publication number: WO1998038889A2
Application number: PCT/EP1998/001291
Authority: WO
Inventors: Hans Kramer
Original assignee: Smithkline Beecham Consumer Healthcare Gmbh
Priority date: 1997-03-06
Filing date: 1998-03-02
Publication date: 1998-09-11
Also published as: JP2002512540A; WO1998038889A3; ZA981870B; TW431151U; AU7426798A

Abstract

A toothbrush in which the bristles project to at least two distinct heights from the bristle face, and the bristles which project to the greatest height are feathered bristles with their free ends split to produce soft fine strands.

Description

Toothbrush

This invention relates to toothbrushes, in particular to hand held toothbrushes for manual use. In particular the invention relates to the bristle group on the toothbrush head. Toothbrushes generally comprise a grip handle and a bristle bearing head, from a bristle face of which project bristles, the head and handle being disposed along a longitudinal axis, generally with a thinned neck in between the head and handle.

Usually the bristles are all of substantially the same length, so that the free ends of the bristles lie generally in a flat plane substantially parallel to the longitudinal axis. However bristle groups are known in which the free ends of the bristles lie in a "square wave" or "castellated" arrangement of alternating long and short tufts e.g. as disclosed in DE P 44 09 395, US 3,229,318 and US 4,672,706.

Also bristle groups are known in which the free ends of the bristles lie in a "triangular wave" or "zig zag" arrangement of sharp peaks with troughs in between, e.g. as disclosed in US 3,188,673, US 2,797 424, US 74560 and WO

91/19437 among others.

Bristles are normally made of resilient flexible plastics material filaments with solid rounded ends. However a bristle material called "feathered filaments" is known and available from DuPont under the Trade Mark "Tynex" . These feathered filaments can be split at the ends such that the end, remote from the toothbrush head, of each such feathered bristle filaments is divided longitudinally into numerous fine soft fine strands. See for example the DuPont publication "Tynex

Shapes & Textures Toothbrush Filaments" (1996). It is an object of this invention to provide a toothbrush with an improved cleaning effect of the interdental spaces, and this is unexpectedly achieved in the present invention as described below.

According to this invention a toothbrush is provided, from a bristle face of the head of which project a group of bristles, characterised in that the bristles in the group project to at least two distinct heights from the bristle face, and the bristles of the group which project to the greatest height are feathered bristles. The feathered bristles may be provided on the toothbrush of the invention as sold with their ends already in the form of numerous fine soft fine strands, or alternately the toothbrush may be supplied to the user with the bristle ends unsplit, and the bristles may split at their ends remote from the bristle face into numerous fine soft fine strands during use, e.g. as a result of the forces and conditions experienced by the bristles during toothbrushing.

The non-feathered bristles may be essentially conventional bristles as normally used on toothbrushes, preferably having their ends remote from the bristle face end-rounded. The distinct heights to which the bristles project may differ in their respective height by 5-30%, e.g. 5-20%, typically 5-10% of the average height to which the bristles project from the bristle face of the toothbrush of the invention.

In a preferred embodiment of the invention the bristles of the group are disposed in discrete tufts which project to two distinct heights from the bristle face, i.e. of higher and less high tofts, and the higher tofts are comprised of feathered bristles with their free ends split to produce soft fine strands.

Preferably the tofts of the group are arranged in a longitudinally aligned "square wave" or "castellated" form of a pattern of higher feathered and less high non-feathered tofts. For example the tofts of the group may be arranged in a longitudinally alternating pattern of laterally, i.e. widthways perpendicular to the longitudinal axis of the toothbrush, extending rows, or groups of laterally extending rows, of higher feathered and less high non-feathered tufts. For example the tufts of the group may be arranged in a longitudinally alternating pattern of laterally extending groups of rows of higher and less high tofts. For example the tofts of the group may comprise laterally extending rows of tofts, and one or more such rows of higher, feathered, tufts may alternate longitudinally with one or more rows of less high non-feathered tofts. For example the group may comprise higher single laterally aligned rows of feathered tofts alternating with single alternating rows of less high non-feathered tufts. In one form of this group the row nearest the base of the head (facing the handle) and the row nearest the tip may be longer feathered bristles, or alternatively they may be shorter non-feathered bristles. The feathered bristles in the toothbrush of this embodiment having a square wave form may be higher than the less high non-feathered bristles by about 5-30% , e.g. 5-20% , typically 5-10% of the average length of the bristles. In terms of distance feathered bristles in the toothbrush of this embodiment having a square wave form group may be higher than the less high non-feathered bristles by typically 0.5-4 mm, e.g. ca. 1.5 mm. The whole or part of that length of the feathered bristles which projects higher than the free ends of the non feathered bristles may be feathered, i.e. with their free ends split to produce soft fine strands. Alternative arrangements of bristles are within the scope of this invention. For example the toothbrush may have the free ends of its bristles in its group lying in a "triangular wave" or "zig zag" arrangement of sharp peaks with troughs in between, for example individual tufts of bristles may have their free ends in a conical or gable shape (e.g. with the ridge of the gable oriented laterally), which may be symmetrical or asymmetrical about the bristle length axis, and the highest parts of the peaks, e.g. the highest about 5-30% , e.g. 5-20% , typically 5-10% of the bristles, may be feathered. For example the peak itself and optionally the parts of the bristles immediately adjacent to the peak may be feathered.

All the tofts of bristles in the toothbrush may be included in such a group of tofts as described above, referred to for convenience hereinafter as the "first group" . Alternatively only part of the entire bristle group of the toothbrush of the invention may be included in such a first group, and the toothbrush may have a first group of bristles as described above, combined with groups of bristles in other arrangements to that of the said first group.

In a particularly preferred form of the invention such a first group of bristles, e.g. a square wave or zig-zag form first group, preferably a square wave or castellated form first group, is combined with a second group of bristles located at the tip end of the first group, the second group being in plan on the bristle face a distinct cluster of tofts, or a distinct single toft of larger cross section than that of the tofts in the first group, the cluster or toft being of a polygonal or rounded shape in plan. Such a cluster may for example comprise a polygon of tofts, e.g. a hexagon, pentagon, quadrilateral, heptagon or octagon, which may be regular or irregular in shape and/or in the length of its sides, preferably surrounding a central toft. Alternatively the polygonal cluster may comprise a number of closely longitudinally spaced lateral rows of tofts, for example with these lateral rows interpenetrating longitudinally. Such a cluster may comprise tufts which are longitudinally or laterally spaced differently to the tofts of the first group.

Preferably this polygonal cluster comprises a hexagon of tofts with a central toft, or a quadrilateral of tufts, and is combined with a square wave form first group located between this cluster and the base end of the head.

Rounded shapes of such a cluster include circular, semicircular, oval and half-oval.

A single distinct toft may comprise a single polygonal or rounded tuft larger in cross section than the individual tufts of the first group. By "rounded" is included inter alia circular, semi circular, oval, semi oval, "U" shaped and "C" shaped etc., with the limbs of the U or C facing the base of the head.

Preferably the bristles in the second group are higher than the less high non- feathered bristles of the first group, preferably being of the same length as the higher feathered bristles. Alternatively the bristles in the second group may be less high than the higher feathered bristles, or may be of a height unrelated to the height of either the higher feathered or less high non-feathered bristles. The tofts in the second group may for example be spaced together more closely than are the tofts in the first group. The bristles in this second group may be feathered or non-feathered, for example non-feathered. In one form of the toothbrush of this invention the first group comprises 6-

10 lateral rows of tufts made up of the said alternating pattern of square wave or castellated -form tofts, with a second group in the form of a cluster of tofts at the tip end. For example the toothbrush may comprise 7-9 rows of tofts in a first group starting at the base end and ending at its tip end with a higher feathered row of tofts, including longer feathered tofts with shorter non-feathered tofts alternating with these. At the tip end of this pattern the second group may be in the form of a cluster of tofts comprising a hexagon with a central tuft or the said quadrilateral of tufts.

The head of the toothbrush may taper, being wider at its end nearest the handle than at the tip remote from the handle, such that the width of the second group of tufts is less than the width of the first group immediately adjacent to the first group. This tapering may be in a wedge-shaped manner.

A suitable arrangement of tufts on the bristle face of the toothbrush is that disclosed in DE 44 09 395, the contents of which are included by reference. Such a bristle arrangement for example has a toothbrush head from which all the bristles project at right angles, a first group of bristles towards the handle being grouped together in tufts arranged in transverse rows extending at right angles to the longitudinal axis of the toothbrush head, the height of the bristles of the first group oscillating up and down, the height of the tufts of the first group alternating in successive transverse rows between two different height levels; a second group of bristles located at the free end of the toothbrush head forming a rounded cluster of bristles and the distance between the first and second group being the same as or smaller than the same distance(s) between the transverse rows of the first group.

For example the tufts of the first group may be arranged in nine widthways aligned rows, the rows successively having 5, 5, 5, 4, 4, 4, 3, 3, 3 tufts in each row counting from the base of the head, being successively alternately long "1" (feathered) and short "s" tufts, i.e. a 51, 5s, 51, 4s, 41, 4s, 31, 3s, 31 arrangement.

The feathered bristles may be of circular cross section, of a diameter similar to conventional non-feathered bristles. The feathered and non-feathered bristles may have a diameter of typically 0.10-0.25 mm, for example the higher bristles, feathered and non feathered may have a diameter 0.15-0.20 mm and the less high bristles may have a diameter of 0.17-0.25 mm.

The bristle face of the toothbrush of the invention may be substantially planar, and the difference in height between the feathered and non-feathered bristles may be achieved by the feathered bristles being longer and hence extending further from the bristle face. Alternately or additionally the bristle face may be non-planar, e.g. having parts which are respectively displaced to greater and lesser extents from the longitudinal axis of the toothbrush, and the higher, feathered bristles may extend from these more displaced parts.

The head and handle of the toothbrush of this invention may also include features known by themselves in the art but novel in combination with the bristle configuration of this invention. For example the handle of the toothbrush, the head, and/or the link between the head and handle of the toothbrush may incorporate features which modify flexibility, for example as disclosed in PCT/EP92/00645 , EP 0336641, WO 92/17093, PCT/EP96/03721, WO 97/24048, WO97/25899, WO 97/25900, the contents of which are hereby incorporated by reference. The toothbrush of this invention may be made by conventional techniques and materials, e.g. by injection moulding of plastic materials, and of elastomer grip pads on the grip handle and flexible composite plastics material-elastomer material links between the head and grip handle. The bristles may be fixed into the head by means of conventional techniques, e.g. with small metal clips jammed into socket holes in the head, or by fusing the fixed ends of the bristles into the head material. The invention will now be described by way of example only with reference to the accompanying drawings which show:

Fig 1 - an enlarged view of the feathered end of a feathered bristle. Fig 2 - a side view of the head of a toothbrush of this invention. Fig 3 - a plan view of the head of a toothbrush of this invention.

Fig 4 - a side view of an alternative type of toft of feathered bristles of a toothbrush of this invention. Referring to Fig. 1, the region at the end remote from a toothbrush head, of an individual feathered bristle 1 (generally) is shown. The bristle material is commercially available and is made of the material Tynex™ supplied by DuPont, and is made with small voids and weld lines that run along the length of the bristle. This enables the end 2 of the bristle to split into numerous soft, fine strands 3. The lower part 4, of the bristle 1 is not split in this way but is a solid bristle. Such splitting may occur during use of the toothbrush. Referring to Figs 2 and 3, a toothbrush head 5 is shown in a side view, a base end 6 of which longitudinally adjoins a grip handle (not shown) via a thinned neck 7, the head having a tip end 8. From a bristle face 9 of the head project bristles arranged in discrete tufts 10 of bristles, the tufts being of substantially circular cross section as shown in Fig 3. The toothbrush has a longitudinal axis A- A, a width direction B--B perpendicular to the axis A--A, and being in the plane of the paper of Fig. 3, and a height direction C--C perpendicular to both the axis A--A and the width B--B, i.e. being in the plane of the side view Fig. 2.

The tofts 10 are arranged in a first group of a longitudinally alternating arrangement of laterally aligned rows of less high shorter tofts 10A and laterally aligned rows of higher longer tofts 10B, and at the tip end of this first group there is a second group in the form of a distinct cluster of tofts IOC in a hexagon around a single central tuft 10D.

In the first group the shorter tofts 10A are tofts of non-feathered bristles, being bristles having a substantially solid rounded end. The tufts 10B are tofts of feathered bristles 1 as shown in Fig. l. The length of the non feathered bristles in tofts 10A is ca. 9 mm, and the length of the feathered bristles in tofts 10B is ca. 11 mm. The whole part 2 A of the feathered bristles in the tofts 10B which projects higher than the free ends of the non feathered bristles 10A is feathered, i.e. the ends 2 of the individual bristles in the region 2A of the tofts 10B are split into numerous soft, fine strands 3, whereas in the lower part 4A, of the tufts 10B the individual bristles 1 in the tofts 10B are not split in this way but is a solid bristle. The tofts IOC are non-feathered and have a length substantially the same as that of the feathered bristles 10B.

As seen in Figs 2 and 3 the alternating arrangement comprises five laterally aligned rows 10B of feathered bristles, and four laterally aligned rows 10A of shorter non-feathered bristles, the arrangement starting at the base end with a row of longer tofts 10B of feathered bristles. These rows 10A, 10B, starting from the base end 6, contain respectively 5, 5, 5, 4 , 4, 4, 3, 3, 3, tofts. The spacing, both laterally and longitudinally, of the tofts IOC in the tip cluster is closer than the spacing of the tofts 1A, 10B. Referring to Fig 4, an alternative toft configuration is shown. In Fig 4 part only of the bristle face 9 of a toothbrush head 5 is shown. The toothbrush of Fig 4 has tofts 10 E extending from its bristle face 9. The free ends of the bristles in these tufts 10E lie in a "triangular wave" or "zig zag" arrangement of sharp peaks 11 with troughs 12 in between. This is achieved by individual tofts 10E of bristles having their free ends in a gable shape with the ridge of the gable oriented laterally, i.e. perpendicular to the axis A--A, these peaks 11 being symmetrical about the bristle length axis A- A. The highest parts of the bristles in the tofts 10E, i.e. the peak 11 itself and the parts of the bristles immediately adjacent to the peak 11 are feathered, i.e. in the region 2B of the toft 10E the ends of the bristles are split into numerous soft, fine strands 3. The bristles in the lower part 4B, of the tuft 1 are not split in this way but are solid bristles.

In use the toothbrush of this toothbrush is used for toothbrushing in exactly the same manner as a conventional toothbrush, and the higher feathered bristles in tufts 10B and peaks 11 more advantageously clean the interdental spaces between the teeth.

Claims

Claims:

1. A toothbrush, from a bristle face of the head of which project a group of bristles, characterised in that the bristles in the group project to at least two distinct heights from the bristle face, and the bristles which project to the greatest height are feathered bristles with their free ends split to produce soft fine strands.

2. A toothbrush according to claim 1 characterised in that the said distinct heights to which the bristles project differ in their respective height by 5-30% of the average height to which the bristles project from the bristle face of the toothbrush.

3. A toothbrush according to claim 1 or 2 characterised in that the shorter tofts are comprised of non-feathered bristles.

4. A toothbrush according to any one of claims 1 to 3 characterised in that the bristles of the first group are disposed in discrete tofts which project to two distinct heights from the bristle face, the higher tofts are comprised of feathered bristles with their free ends split to produce soft fine strands and the less high tufts are comprised of bristles having non-feathered ends.

5. A toothbrush according to claim 4 characterised in that the tofts of the first group are arranged in a "square wave" form of an alternating pattern of higher and less high tofts.

6. A toothbrush according to claim 5 characterised in that the tofts of the first group are arranged in a longitodinally alternating pattern of higher and less high tofts or groups of laterally extending rows of tofts.

7. A toothbrush according to claim 6 characterised in that the tofts of the first group comprise laterally extending rows of tofts, and one or more such rows of higher, feathered, tofts alternate longitodinally with one or more rows of less high non-feathered tofts.

8. A toothbrush according to claim 7 characterised in that the first group comprises higher single lateral rows of feathered tofts alternating with single alternating rows of less high non-feathered tofts.

9. A toothbrush according to claim 7 characterised in that the row nearest the base of the head (facing the handle) and the row nearest the tip, may be longer feathered bristles.

10. A toothbrush according to any one of claims 5 to 9 characterised in that the feathered bristles in the toothbrush of this embodiment having a square wave form first group are higher than the less high non-feathered bristles by about 5-30% .

11. A toothbrush according to any one of claims 1 to 4 characterised in that the toothbrush has the free ends of its bristles in its first group lying in a "triangular wave" or "zig zag" arrangement of sharp peaks with troughs in between.

12. A toothbrush according to claim 11 characterised in that individual tufts of bristles have their free ends in a conical or gable shape and the highest parts of the peaks are feathered.

13. A toothbrush according to any one of the preceding claims characterised in that all the tofts of bristles in the toothbrush comprise a square wave or zig-zag form first group of tofts.

14. A toothbrush according to any one of claims 1 to 12 characterised in that the toothbrush has a first group of bristles combined with groups of bristles in other arrangements to that of the said first group.

15. A toothbrush according to claim 14 characterised in that a first group of bristles is combined with a second group of bristles located at the tip end of the first group, the second group being in plan on the bristle face a distinct cluster of tofts, or a distinct single toft of larger cross section than that of the tofts in the first group, the cluster or toft being of a polygonal or rounded shape in plan.

16. A toothbrush according to claim 15 characterised in that a second group is present in the form of a cluster comprising a polygon of tofts surrounding a central toft.

17. A toothbrush according to claim 16 characterised in that the polygonal cluster comprises a hexagon of tofts with a central tuft and is combined with a square wave form first group located between this cluster and the base end of the head.

18. A toothbrush according to any one of claims 15 to 17 characterised in that the bristles in the second group are higher than the less high non-feathered bristles of the first group.

19. A toothbrush according to any one of claims 15 to 18 characterised by comprising 6-10 lateral rows of tufts made up of an alternating pattern of waveform tofts, with a second group in the form of a cluster of tofts at the tip end.

20. A toothbrush according to claim 19 characterised by 7-9 rows of tofts in a first group starting at the base end and ending at its tip end with a higher feathered row of tufts, including longer feathered tofts with shorter non-feathered tofts alternating with these, and at the tip end of this pattern a second group in the form of a cluster of tufts comprising a hexagon with a central toft or the said quadrilateral of tufts.