JP3305329B2 - toothbrush - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a bristle arrangement for a toothbrush, in particular heads arranged in separate groups separated by a gap extending from one side of the head to the other. The present invention relates to a toothbrush having a bristle bundle. The arrangement and orientation of the bristle bundles allows the groups to operate without substantial interference from adjacent bristle bundles while maintaining a high overall density of the bristle bundles in the toothbrush head.

BACKGROUND OF THE INVENTION Effective brushing requires both good contact of the bristles with the entire tooth surface and the penetration of the bristles into the interdental and other gaps. A typical toothbrush having a uniform bristle bundle gap across the brush head provides good bristle contact, but the penetration between adjacent bristle bundles limits penetration into the interdental area That is, the entire set of bristles tends to move as an integral array.

Various arrangements of the bristles of the toothbrush head have been described with the aim of improving the quality of brushing.

For example, WO 91/19437 describes a toothbrush having a three-dimensional profile of a bristle to improve interdental cleaning. EP-A-449,653 and EP-A-449,655 disclose brushes having bristles bundles planted at a certain angle to the toothbrush head and to one another to clean the gingival margin and interdental area. are doing. It also states that the bristle bundles cannot structurally support each other, allowing the individual bundles to enter the interdrum gap and interdental space without being disturbed by the surrounding bristle bundles. WO96 / 0
1578 describes a multi-stage bristle bundle intended to stimulate the gums and provide a unique oral sensation that signals effective cleaning. WO 96/15696 is directed to a toothbrush having a strip of flexible and resilient material protruding from the head and enhancing the cleaning effect of the teeth.

Another approach to improving cleaning involves modifying the shape or behavior of the toothbrush head. For example, WO
91/19438 discloses a toothbrush with a weakened area in the head that is deformed to fit the individual size and shape of the user's dentition. Bristle rows are eliminated in weak areas. WO 96/02165 and other documents cited therein conform to the user's teeth during brushing,
Or describes a brush with a flexible head that can be adapted.

WO94 / 09677 is also to improve toothpaste performance,
FIG. 11 shows another modification in which rectangular bristles in two general orientations are used for the same brush head.
The above document outlines the prior art which describes the use of rectangular bristles to obtain different brushing characteristics for different brush movements.

Apart from these, the use of toothbrushes has received much attention from dentists over the years. Preferred methods of toothbrushes, such as bath and rolling methods, are described in NO Harrison and AG Christen, "Basic Preventive Dentistry," 4th Edition, Appleton & Lange (Ap.
pleton & Lange).

Despite the above and other literature on toothbrushes, there is still a need for improved brush structures.

Accordingly, it is an object of the present invention to provide a toothbrush in which the bristle bundle can move independently while maintaining a high overall density of the bristle bundle.

It is a further object of the present invention to provide a toothbrush that allows the bristles bundle to move independently while achieving a favorable orientation of the bristles with respect to the tooth surface during brushing.

It is a further object of the present invention to provide a toothbrush having a bristle arrangement wherein the head is comfortable in the mouth and which aids in improved cleaning.

SUMMARY OF THE INVENTION According to the present invention, there is provided a handle and a head attached to one end thereof, the head comprising a handle end, a free end and a plurality of bristle bundles extending therefrom. Surface, wherein each of the bristle bundles has a base and a free end, and is a toothbrush having one or more bristles, the bristle bundles comprising groups separated by a lateral gap. The distance between the bases of the bristle bundles in the same group is less than 1.3 mm, and the distance between the bases of the bristle bundles between groups is 1.3 mm to 5 mm
And the distance between the free ends of the bristle bundle between groups is at least 0.5 mm.

According to a second aspect of the invention, the handle comprises a handle and an elastically flexible head attached to one end thereof, the head comprising a handle end, a free end and a plurality of bristles bundles therefrom. A toothbrush having an extending flocked surface, each of the bristles bundles having a base and a free end, and having one or more bristles, wherein the bristle bundles are separated from each other by a lateral gap. Arranged in separate groups, the distance between the bases of the bristle bundles within the same group is less than 1.3 mm, and the distance between the bases of the bristle bundles between groups is in the range of 1.3 mm to 5 mm A toothbrush is provided.

This arrangement allows independent movement of the bristle bundle while maintaining a high density of the bristle bundle in the brush head.

DETAILED DESCRIPTION OF THE INVENTION The toothbrush of the present invention may be an integral toothbrush such as a conventional manual structure, a toothbrush having a replaceable head as in an electric toothbrush, or a head portion that can be fixed, but a replaceable It may have a bristle support insert. The toothbrush has a handle and a head attached to one end of the handle. The structure of the handle is not critical to the invention and is generally of a conventional elongated shape. Preferably, it is ergonomically designed to incorporate features such as an elastomer insert to improve the grip of the user and a thumb or index finger to improve operability. In a preferred embodiment, the handle includes a neck portion that is sufficiently curved to allow the free working end of the bristles to be substantially coplanar with the handle, as described below.

The head portion of the toothbrush has a flocked surface from which a plurality of bristle bundles extend, a free end having a pointed end, and a handle end. The head further has two opposing sides extending from the free end of the head to the handle end.
The handle end may be connected to an elongated handle as in an integral toothbrush, or may be connected to a separate handle. In each case, the longitudinal axis of the handle defines the longitudinal axis of the head portion, and the free end and the handle end are located at both ends of the longitudinal axis. The head also has a transverse axis orthogonal to the longitudinal axis and substantially parallel to the flocked surface. In the specification, the terms “horizontal axis” and “long axis” mean directions parallel to the horizontal axis and the longitudinal axis, respectively, unless otherwise specified. Suitably, the head itself is also elongated and its major axis is also the longitudinal axis. The toothbrush head can also have a replaceable insert that fits within the support frame, as described in EC-A-704,179. In this latter case, "head" means a frame and insert assembly that is assembled for use when brushing teeth.

As used herein, "bristle bundle" refers to a set of one or more bristles that are fixed to a brush at a common location. The bristles used herein can be made of any material known in the art. Here, suitable bristle materials include polyester and nylon,
For example, STP's Dupont Tynex
(Registered trademark) 612 and Stylon (registered trademark) 6
There are twelve. The bristles preferably have a circular cross section, but may have other cross sections, including, but not limited to, rectangular, hexagonal and three-chamber. Further, the diameter and length of the bristle can vary within the usual dimensions known to those skilled in the art. In a preferred embodiment, the bristles have a diameter between 0.1 mm and 0.25 mm, and between 7 mm and 15 mm, preferably between 9 mm and
12 mm long circular cross section, each bristle bundle about 10
It has from about 50 bristles. In such an embodiment, each bundle is substantially circular with a diameter of about 1 mm to about 2 mm. Cutting the bristle and rounding the ends can be done using any of the methods well known in the art. As used herein, the term "brissle" is
Includes another flexible strip of cleaning material as described in WO 96/15696. In such a case, it would be appropriate for the bundle to consist of just one bristle. Attachment of the bristle bundle to the brush head can be performed using any method known in the art, such as fusing, stapling, or injection molding.
The preferred method here is stapling and fusing.
Each bristle bundle has a base and a free end, the free end of the bundle forming a working surface used to clean teeth. The "base" of the bundle used here is the portion where the bundle contacts the surface of the brush head. It will be appreciated that a portion of the bundle extends below the base into the brush head to secure the bristle bundle within the head. To accommodate that portion of the bristle bundle in this way, it is preferred that the head portion has a preformed flocked hole. The flocked holes may be of any cross section, including square and rectangular, but circular is preferred. Its depth and diameter are chosen by those skilled in the art according to the bristle bundle inserted therein. Bristles inserted into a common flocking hole are considered to be fixed at a common location and are considered to be part of the same bundle.

The head portion has a length L, and the length is perpendicular to the longitudinal axis of the head portion at a position near the point closest to the handle, from the tip of the free end, at the base of the bundle or bundle array closest to the handle. It is measured up to the line drawn. In general, L is about
It is in the range of 15mm to about 35mm, preferably about 20mm to about 30mm.

The bristle bundles are arranged in a plurality of groups N,
Each group is separated from its neighbors by a lateral gap, but there are N-1 gaps. N is at least 2, preferably 3 to 5, and more preferably 4.
Each group consists of one or more bundles, preferably from about 5 to about 20 bundles, more preferably from about 7 to about 12 bundles. The total number of bundles is suitably from about 25 to about 50, preferably from about 30 to about 40, and more preferably about 35. "Transverse gap" means the area on the flocked surface that extends from one side of the head to the other and is free of clumps, so that each gap is located on each side of the head. Two ends. The lateral gap can be linear or non-linear and is determined by the pattern of the bundle on the flocked surface. The straight line drawn between the two ends of the gap is preferably parallel to the horizontal axis of the head,
The direction may be oblique to the horizontal axis.

Within each group, the distance between the bases of adjacent bundles is less than 1.3 mm, preferably 0.6 mm to 1.2 mm, more preferably 0.8 mm
To 1.1 mm. The distance between the bases of the bundle referred to herein is measured between the bundle edges along a straight line drawn between the centers of the bundles along the flocked surface. The distance between the free ends of the bundle referred to herein is measured between the bundle edges along a straight line drawn from the free end of the short bundle parallel to the flocking surface and between the centers of the bundles. Unless clearly defined differently, the distance between bundles refers to the distance between the bases of adjacent bundles. "Adjacent bundles" are the bundles that are closest.

The distance between the bases of adjacent bundles of adjacent groups, the distance measured across the gap between the groups, and the gap between the groups is from about 1.3 mm to about 5 mm, preferably from about 1.5 mm to about 3.5 mm, more preferably It is in the range from about 1.7mm to about 3mm. Although there is some variation between individual bundle pairs, if pairs members belong to different groups, all pairs are at least 1.3 mm apart at their base.

By relatively increasing the distance between the bundles of adjacent groups, the bundle groups can operate independently of one another. That is, a bundle of one group does not substantially interfere with a bundle of an adjacent group.
For this reason, in particular, the bundles at the periphery of the group penetrate well into the interdental and other gaps. Nevertheless, by reducing the distance between the bundles in the group, the overall density of the bundles is maintained at a relatively high level. This allows, in particular, a good covering of the individual tooth surfaces by the bristles.

To maximize the benefits of the present invention, it is necessary that the bundle not only be separated at the base, but also at its free end not to interfere with the individual movements when using the brush. is there. For a conventional stiff brush head, the distance between the free ends of the bundle between groups should be at least 0.5 mm, preferably at least 1 mm, more preferably at least 1.7 mm. This condition is that the bundles are parallel to each other,
And automatically when the bristles in the bundle do not spread towards the free end.

The bundle can be substantially perpendicular to the flocked surface of the toothbrush head or can be inclined at a greater angle. By “substantially perpendicular” is meant that the central axis of the bundle is oriented at an angle of less than 10 ° to a perpendicular passing through the center of the flocked surface. Preferably, at least 70%, more preferably at least 80%, of the bundle is substantially perpendicular to the flocked surface of the toothbrush head. In a particularly preferred embodiment, the entire bundle is substantially perpendicular to the flocking surface of the toothbrush head so that they are all essentially parallel to each other. Bundles that are nearly perpendicular to the flocked surface generally make good contact with the tooth surface, thus providing good cleaning. They are also less prone to "flattening", ie, less prone to flattening bristle bundles with repeated use. The flattened bundles have an unsightly appearance and impair the brush cleaning effect. However, some bundles can be tilted more than 10 ° with respect to the flocking surface. For example, it is desirable to incline some of the bundles of the outer longitudinal row to the side of the brush head, so that the gingival margin can be gently cleaned. Preferably, the bundles are not tilted in a direction approaching each other, especially across the gap between the groups, as this would detract from the advantages of the present invention.

As described below, in the elastically-flexible brush head portion, it is possible to alleviate the need to make the distance between the free ends of the bundle between groups at least 0.5 mm. This means that when pressure is applied to the brush during use, it becomes more convex,
This is because the free ends of the bundle tend to move away from each other. However, the free end of the bundle is still at least 0.5m
m, preferably at least 1 mm, more preferably at least 1.5 mm spacing.

The overall density of the brush head bundle is a function of the size of the head and the number of bundle groups and the size of the gap between the groups. In a preferred embodiment, the average distance (G) between adjacent bundles in an adjacent group is from about 0.15 · L / (N−1) to about 0.3 · L /
(N-1). That is, the smaller the number of groups, and thus the smaller the number of gaps between groups, the larger the gap can be, but if the gap exceeds 5 mm, significant improvement in individual movement of the bundle group will not be obtained, They waste space. The average distance between adjacent bundles in adjacent groups is determined by taking the numerical average of the distances between adjacent bundles in a pair, if one bundle is located on each side of the gap between groups.

Both the overall density of the bristle bundle and the degrees of freedom of the individual bundles operating independently of each other are also influenced by the shape of the bundles and the arrangement of the bundles within the bundle. Although a rectangular group of bristles with bristle bundles arranged in a conventional straight row can be used, good results are obtained if the bundles in the same group are at least partially offset from each other along the horizontal axis. "At least partially offset" means that for any bundle at least 50% of the width of the bundle measured along the longitudinal axis, 1.3 mm when measured along a line parallel to the horizontal axis, preferably Means that no other bristle bundles are present within 1.5 mm. In particular,
The distance to the next bundle is at least 70% of the width of the bundle, more preferably at least 100% and more than 1.3mm, preferably 1.5mm
Longer. In a preferred embodiment, at least 50%, more preferably at least 70%, of the total number of bundles is at least partially offset in either of two directions along the horizontal axis. Thus, when brushing using the recommended bath method of placing the toothbrush along the teeth and moving it up and down, the bundles can easily pass each other and the resistance to up and down movement is the longitudinal movement of the brush. Smaller than the case. One way to achieve such a staggered arrangement is to arrange the bundle groups in a parallelogram shape, in which case the gap between the groups is substantially linear, but the The direction is inclined with respect to the longitudinal axis and the horizontal axis. In a preferred configuration, one or more of the groups of bundles is in a crescent or chevron arrangement. "Crescent" and "angle" are symmetrical about the longitudinal axis, but at least two longitudinal bundle rows in the array are longitudinally separated from adjacent ones by a distance of at least 20% of the average width of the bundle. , So that the entire group has an almost arc-shaped or "V" -shaped appearance with the apex located on or near the central longitudinal axis. The overall density of the bundle is maintained by grouping the groups in a bite-shaped manner such that the gaps between groups are approximately parallel to each other. In a preferred embodiment, this is achieved by placing at least N-1 bundles in a crescent array. A group of one end, preferably the group closest to the handle end, need not be so formed. It can be, for example, oval, diamond or circular. A further advantage of crescent or chevron bundles is that they can make better use of the space at the sharp or rounded free end of the brush head. For this reason, it is particularly preferred to point the crescent-shaped or chevron-shaped top toward the free end of the head.

The working surface formed by the free end of the bundle can be any suitable shape, such as planar, concave or corrugated. Preferably, it is processed into a waveform as described in WO91 / 19437. More preferably, a portion of the outer bundle row has a raised profile, as described in WO 96/07343.

The toothbrush head of the invention is preferably elastically flexed, for example as described in WO 96/02165.
"Elastically flex" means that when the handle end is fixed just behind the last bristle row and a free end of at least 2 Newtons is applied to the free end of the head,
゜, preferably at least 5 °, more preferably at least 10 ° (flexing angle), and when the 3 Newton's force is removed, the free end of the head portion is returned to its original position without external force. Means to return to. The deflection angle is less than 40 °, preferably less than 30 °, more preferably less than 20 °. This has been found to provide an acceptable degree of flexibility for the user without exposing the hinge and elastomeric segment joints to excessive stress. Further, it is preferable that the toothbrush head portion has a concave flocked surface without stress. The elastically flexing brush head can be well adapted to various contours of the teeth,
Helps individual bundles penetrate between teeth and other gaps. Further, it is preferable that the flocked surface of the toothbrush head is concave along the longitudinal direction without stress. The radius of curvature can be varied along the length of the head. The radius of curvature is preferably 10 mm to 500 mm, more preferably 15 m
m to 250 mm, especially 25 mm to 150 mm.

A further advantage of having a relatively large gap between the groups is that the gap can form a lateral groove in the flocking surface to allow the head to flex as described in WO 96/02165. That is. The grooves allow the head portion to flex or bend. The grooves may be linear or non-linear, but preferably follow the shape of the gap.

In the preferred embodiment herein, the toothbrush head is provided with a lateral groove in each gap between the bundles, so that the head can bend along the longitudinal axis. this is,
When pressed against the teeth, the toothbrush head flexes to have a convex profile along the longitudinal axis. This is particularly suitable for brushing the lingual or medial side of the teeth. Preferably, there is a corresponding groove on the back of the brush, WO96
The groove is preferably filled with an elastomer, as described in US Pat. A preferred method of constructing a flexible brush head is in accordance with our co-pending UK Patent Application No. 9601013 and is briefly summarized below to illustrate the best embodiment of a brush according to the present invention. You.

The brush head portion has a pair of opposing surfaces, one of which is a flocked surface, on which bristles are attached and extend therefrom. The head portion has two or more segments flexibly connected by grooves between them so that the brushing action allows the head portion to flex and conform, for example, to the various contours of the teeth of an individual user. Like that. The head further has an elastomer filled in at least one surface of the groove. The elastomer improves the elasticity of the head by acting like a spring, so that when the force applied to bend the head is removed, the head returns to its original shape in a short time. The grooves form hinges between the segments.
The hinges are preferably located between the faces and are preferably at least about 10% of the depth of the head from each face, rather than being in the same plane as any of the faces. Elastomers can also limit the degree of bending, so that when high levels of force are applied, the deflection of the head is limited, reducing the appearance of excessive strain on the hinges, and thus the durability of the product. Improve the performance.

The head and handle are generally conventional in the manufacture of toothbrushes, but preferably have a modulus of elasticity of at least about 500 MP.
a, more preferably made from a relatively incompressible material of at least about 1000 MPa, especially a plastic material. Suitable plastics materials include, for example, polyamides and polypropylenes. Polypropylene is preferred. Suitable polypropylene has an elastic modulus (ISO178) of 1500
There are the "Polypropylene PM1600" from MPa (sold by Shell) and the April 3400MA1 from Elf Atochem. Preferably, Boehringer
A blowing agent such as Boehringer-Mannheim's Hydrocerol HP20DP may comprise from about 1% to about 3%, preferably from about 1.5% to about 2.5% by weight of polypropylene.
At the level of polypropylene. The blowing agent aids the flow of the polypropylene during molding and in particular helps to ensure a uniform formation of the hinge. The handle itself is generally rigid and can be formed into a shape conventional in the manufacture of toothbrushes. Optionally, as is known in the art, the handle may be provided with a neck portion that is more flexible than the rest thereof, but when using a force on the head portion during use, the teeth When brushing the head, provided that the remaining portion of the handle has sufficient rigidity that the head portion still bends in the manner and range described below.

The toothbrush head has a groove on the flocked surface and the opposite surface, and the groove is a space between the segments.
The grooves allow the head to flex, ie, bend.
The grooves may be oriented in a direction transverse or parallel to the longitudinal axis of the handle, and may be linear or non-linear, such as curved or zig-zag. The non-linear groove helps offset the compressive stress of the elastomeric material filling the groove as the head bends. "Lateral groove"
May include a groove whose main axis, defined by the straight line connecting the start and end points of the groove, is offset from the horizontal axis of the head by no more than 45 °. Similarly, "longitudinal groove"
May also include grooves whose main axis is offset from the longitudinal axis of the head by an angle within 45 °.

In a preferred embodiment, the brush head is one on each side.
With the lateral grooves described above, the head can bend along the longitudinal axis. This allows the brush head to flex to have a convex profile along the longitudinal axis when pressed against the teeth. This is particularly suitable when brushing the lingual or inner surface of the teeth.

The brush head may also have one or more longitudinal grooves. The longitudinal grooves can deflect, for example, the outer row of longitudinal bristle rows away from the inner ones.

In a particularly preferred embodiment, the brush head portion has lateral grooves provided on each of the two sides so that the head portion can bend along the longitudinal axis, and allows the elastomer to flow from groove to groove during the molding process. To have at least one longitudinal groove connecting the lateral grooves. In a one-piece brush having a co-molded handle, by extending this longitudinal groove along the handle, a mold elastomer commonly used in supplying elastomer to form a hand grip is provided. The injection point can also be used to inject the elastomer for the head groove. Preferably, the longitudinal groove extends on the back of the head part, i.e. on the side opposite to the flocking surface, so that it does not interfere with the flocking.

One groove of the two opposing surfaces may be directly opposed to the groove of the other surface, or may be partially or completely displaced. Preferably, the grooves are directly opposed or only partially offset.

The groove separating the segments of the head also forms a hinge, which is the area where the head is thinner at the base of the groove.

The width and depth of the grooves can be made variable, and the distance between the grooves can also be changed. In this way, the flexibility of the head along its length and / or width can be varied. Preferably, only the lateral grooves are modified in such a manner. By changing the depth of the groove, the position and thickness of the hinge connecting the segments are adjusted. For a toothbrush head having a thickness of about 4 mm to about 6 mm, typically about 5 mm, a suitable groove depth is in the range of about 1.4 mm to about 3 mm, preferably about 1.5 mm to about 2.8 mm. Suitable hinge thicknesses range from about 0.4 mm to about 2.0 mm, preferably from about 0.5 mm to about 1.5 mm. If a lateral groove is used, it is desirable that the hinge closer to the handle be less flexible than the hinge further away. In this way, the bending of the head portion can be made more uniform.
The change in flexibility is achieved by changing the thickness of the hinge. In a preferred embodiment, the hinge closest to the handle has a thickness of about three times, and preferably up to about twice, the hinge farthest from the handle. An example of a hinge thickness of a toothbrush having three lateral grooves is about 1.1 mm, 0.6 mm and
0.6 mm. If the same hinge is used along the brush head, deflection of the head tends to occur primarily at the hinge closest to the handle. The depth of the flocked surface groove can be changed to that of the opposite side. Preferably, the grooves on the flocking surface are not deeper than the grooves on the opposite side. In embodiments where the grooves on both sides contain elastomer, this results in more elastomer undergoing compression than elastomer undergoing tension. The elastomer at the junction between the segments is stronger under compression than under tension.

Increasing the width of the grooves increases their flexibility, because they increase the gap between the segments and thus the length of the hinges. However, it is preferable to implant the bristles in the segments, rather than in the elastomer, so for a fixed size head, increasing the length of the groove will reduce the space for the bristles. Suitable groove width is about
It is in the range of 0.3 mm to about 3.0 mm, preferably about 1.2 mm to about 2.0 mm. The groove is tapered slightly inward toward the bottom of the groove for ease of molding, from about 3 to about
It is preferred that it be narrowed at an angle of 10 °. As the brush flexes, the width of the groove changes faster at the top of the groove than at the bottom of the groove, with the relative change being a function of the width and depth of the groove. Since this change in groove width results in compression or tension of the elastomer in the groove, for a given elastomer, the groove geometry may be used to adjust the flexibility of the head. You will understand.

The hinges can be the full length of the groove, but when the grooves in these areas have the full depth of the head, one or more gaps can preferably be provided in the hinge, i.e. on its sides. This has the advantage that a single injection point for the elastomer can be used when molding the head. This gap allows the elastomer to flow from one surface to the other during the molding process. In a preferred embodiment, the hinges are discontinuous when two or more hinges, preferably exactly two, connect each segment to an adjacent segment or handle. In this embodiment, there are gaps between the hinges and on each side. In the case of a linear groove, the hinge width is generally not important if a gap can still be formed, but a wide hinge may be distorted when used in a non-linear groove. Suitable hinge widths are from about 0.5 mm to about 4.0 mm, preferably about 1.0 m
m to about 3.0 mm.

Each hinge should be at least about 10
%, Preferably at least about 20%, more preferably at least about 30%. The distance from the surface to the hinge is measured by a perpendicular drawn from the top of the surface to the nearest interface at the center of the hinge.
Providing the hinges away from the faces of the brushes means that they undergo less tension or compression when the heads flex, and improves their durability. In a particularly preferred embodiment, the brush head portion comprises lateral grooves arranged in pairs such that one of each pair is on each side and directly opposite the other of the pair, between which the By connecting the segments with one or more hinges, each hinge has between at least two surfaces at least about a depth of the head from each surface.
10%, preferably at least about 20%, more preferably at least about 30%.

The grooves on at least one side of the brush contain an elastomer. This can be done in a separate injection molding stage after the molding of the head segment is completed. Preferably, all elastomers are injected from a single injection point. However, separate elastomer injection points in the mold to supply the elastomer for the individual elastomeric members in the head portion, e.g., one that supplies the elastomer to the flocking surface, and another that supplies the elastomer to the opposite surface An injection point can be provided. Thus, when the head deflects in a direction perpendicular to both surfaces, the elastomer is placed in either a tensioned or compressed state. The elastomer has the effect of limiting the flexibility of the head, thereby reducing the stretching or compression of the hinge,
In addition, the effect of limiting the stress at the joint between the elastomer and the segment of the head portion is also exerted. For this reason, a head part with higher durability can be obtained. Preferably, the grooves on both the flocked and opposing surfaces are filled with an elastomer so that the elastomer is compressed no matter which direction is selected. Of course, the elastomer on the opposite side is placed under tension, but the tensile stress on the joint between the elastomer and the segments is limited and distributed between the hinge material.

After molding of the head segment is complete, it is generally preferred that a separate molding step completely fills all grooves with elastomer. Filling the grooves completely has the advantage of avoiding contamination of the grooves, for example due to the attachment of toothpaste. However, the grooves need only be partially filled if enough elastomer is used to provide an effective relaxation of the flexibility of the head.

Suitable elastomers include thermoplastic elastomers having a Shore hardness of 30 to 80 and an elastic modulus of less than about 500 MPa, preferably less than about 300 MPa, such as Santoprene (Santopren).
e) and Thermoflex. As an example of elastomer, elastic modulus (ISO178) is 100MPa,
"PTS Thermoflex 7" with hardness (ISO868) of 80 Shore A
5 "(sold by Plastic Thechnologie Service, Germany). Elastomers PL12291, PL12292 and PL12293 (Multibase, SA, France)
int Laurent Du Pont) is also suitable for use here. In general, selecting an elastomer based on a polymer of the same chemical type as the material for the head segment can facilitate bonding between the elastomer and the head segment. For example, when the head segment is made from polypropylene, the elastomer is preferably based on polypropylene. Optionally, the elastomers are mixed with a suitable plasticizer or blowing agent to enhance their compressibility. The color of the elastomeric material can be the same as the color of the head segment, but can also be a different color to give a noticeable stripe or other pattern.

The invention will now be described, by way of example only, with reference to the accompanying drawings, in which FIG. 1 shows a first embodiment of the invention showing the arrangement of a bundle on a toothbrush head. FIG.

FIG. 2A is a plan view of another embodiment in which a lateral groove provided in a gap between bundles is filled with an elastomer.

FIG. 2B is a side view of the embodiment of FIG. 2A, without showing the elastomer in the groove closest to the handle to expose the hinge.

FIG. 3 is a perspective view of a toothbrush head according to the present invention.

FIG. 4 is a schematic plan view illustrating the measurement of the bundle offset along the horizontal axis.

Referring to FIG. 1, the toothbrush head 1 includes a rounded free end 2 having a point 3, a handle end 4, and a side 5 extending from the free end to the handle end. A plurality of bristle bundles 6 extend from the flocking surface 7. The bundles are arranged in four groups separated from one another by gaps 8. The three groups closest to the free end are each in a crescent arrangement. The group closest to the handle end is generally oval or rhombic.

Within each group, the bundles are relatively closely spaced, and the distance T between the bases of adjacent bundles varies from 0.6 mm to 1 mm.
Since the adjacent bundles of adjacent rows are offset from one another along the horizontal axis, their free ends can easily move across each other when brushing in a bus manner. The distance between the bases of adjacent bundles in adjacent groups varies from 1.9 mm to 3 mm. The length L of the head is 29.6 mm.

Referring to FIGS. 2A and 2B, the toothbrush head 1 is
It has a groove 9 filled with an elastomer, which makes the head part 1 elastically flexible. With the handle end fixed just behind the last horizontal row of bristle, when a force of 3 Newton is applied to the tip of the free end of the head, the free end bends within 15 °, When the 3 Newton force is removed, the free end of the head returns to its original position without applying any external force. The flocking surface of the head portion is concave in the longitudinal direction without stress, and has a radius of curvature of 75 mm.
A groove 9 divides the head into a plurality of segments 10.
The segments are connected only by a pair of thin hinges 11. For the sake of clarity only, only the hinge inside the groove closest to the handle end is shown, the others are hidden by elastomer. The bundles are arranged in four groups separated from one another by gaps 8. The three groups closest to the free end are each in a crescent arrangement. The group closest to the handle end is generally oval or rhombic. The bundles are all substantially perpendicular to the flocked surface, i.e., the central axis of each bundle forms an angle of less than 10 ° with respect to the perpendicular indicated by ZZ in FIG. I have. As a result, the distance (F) between the free ends of the bundle is essentially the same as the distance between the bases. In an unstressed state, the flocked surface of the head is concave, so that the bundle at each end of the head is parallel to the central axis (ZZ) and to each other, but at their attachment points, Not vertical. According to a further aspect of the invention, it is preferred to form a curved brush head with flocking holes all parallel to the axis Z-Z in the axial direction. This has the advantage that the pins used to form the flocking holes in the molding process are more easily removed from the forming brush body without distortion of the flocking holes. .

FIG. 3 shows an embodiment of a brush head having a horizontal axis (XX) and a longitudinal axis (YY), in which 35 bristle bundles 6 are arranged in four groups and are arranged in groups. A lateral gap 8 is provided between them. The bundles are arranged in four groups separated by gaps 8. Each group is in a crescent-shaped arrangement. All the bundles are perpendicular to the flocking surface of the head and are approximately the same length so that their free ends 12 form a flat working surface. Within each group, the spacing of the bundles is relatively narrow, and the bases 13 of adjacent bundles
The distance between varies between 0.7 mm and 1 mm. The bundle is symmetrically arranged with respect to the longitudinal axis Y-Y of the head portion. Regardless of which direction along the horizontal axis is selected, for 30 bundles, at least 60% of the width of each bundle must be within 1.3 mm of the other measured within a line parallel to the horizontal axis. Bundle does not exist. Due to symmetry, the middle two bundles in a row containing four bundles are on the same horizontal axis. Free end 2 of head
Are slightly offset from each other. The head part has a transverse groove 9 located in the gap between the groups and filled with elastomer.

FIG. 4 shows a partial plan view of the head portion, in which only three bundles 14, 15 and 16 are shown for clarity.
The horizontal axis is orthogonal to the longitudinal axis (Y-Y). Bundle 14 has a width W measured along the longitudinal axis. When viewed in the X direction along the horizontal axis, for 70% of width W, the bundle adjacent to bundle 14 is bundle 16, which is at least 2 m for full width W.
m away. However, for 30% of width W, bundle 1
The four lateral protrusions overlap the bundle 15, which is separated by less than 1.3 mm along the X direction. The same analysis, bunch 16
Also applies to bundle 15 for. In the case of bundle 16, it is in the outer row, so there is no bundle in the X direction.

Continuation of the front page (72) Inventor Shenton, Simon Philippe Berkshire, S.L.1, 5, S.N., Slow, Chippenham, Eglimont, Gardens 5 (56) References Table 6-507792 (JP, A) United States Patent 3188672 (US, A) UK Patent 471387 (GB, B) (58) Fields investigated (Int. Cl. ⁷ , DB name) A46B 9/04

Claims (8)

(57) [Claims] 1. A handle and a head attached to one end of the handle, the head having a handle end, a free end, and a flocked surface from which a plurality of bristle bundles extend. Wherein each of said bristle bundles has a base and a free end;
And a toothbrush having one or more bristle bundles, wherein the bristle bundles are arranged in groups separated by a lateral gap, between the bases of the bristle bundles in the same group. The distance of 1.
Less than 3 mm, the distance between the bases of the bristle bundle between groups is 1.3 mm
And the distance between the free ends of the bristle bundles between groups is at least 0.5 mm, and the average distance G between bundles of adjacent groups is the length of the head section L And a function of the total number N of bundle groups, from about 0.15 · L / (N-1) to about
Toothbrush that is in the range of 0.3 · L / (N-1). 2. A flocked surface having a handle and an elastically flexible head attached to one end thereof, the head having a handle end, a free end and a plurality of bristles bundles extending therefrom. A toothbrush having a base and a free end and having one or more bristle bundles, wherein the bristle bundles are separated from each other by a lateral gap. The distance between the bases of the bristle bundle in the same group is 1.
Less than 3 mm, the distance between the bases of the bristle bundle between groups is 1.3 mm
And 5 mm, and the average distance G between bundles in adjacent groups is a function of the length L of the head section and the total number N of bundle groups, from about 0.15 · L / (N−1) to about 0.15 · L / (N−1).
Toothbrush that is in the range of 0.3 · L / (N-1). 3. A handle and a head attached to one end of the handle, the head having a handle end, a free end, and a flocked surface from which a plurality of bristles bundles extend. Wherein each of said bristle bundles has a base and a free end;
And a toothbrush having one or more bristle bundles, wherein the bristle bundles are arranged in groups separated by a lateral gap, between the bases of the bristle bundles in the same group. The distance of 1.
Less than 3 mm, the distance between the bases of the bristle bundle between groups is 1.3 mm
And the distance between the free ends of the bristle bundle between groups is at least 0.5 mm, and one or more groups of the bundle form a crescent or chevron arrangement. Toothbrush. 4. A flock surface having a handle and an elastically flexible head mounted at one end thereof, the head having a handle end, a free end and a plurality of bristles bundles extending therefrom. A toothbrush having a base and a free end, and having one or more bristles, wherein the bristle bundles are in groups separated by a lateral gap. The distance between the bases of the bristle bundle in the same group is 1.
Less than 3 mm, the distance between the bases of the bristle bundle between groups is 1.3 mm
A toothbrush that is within the range of 5 to 5 mm, and wherein one or more groups of the bundle form a crescent or chevron arrangement. 5. The toothbrush according to claim 1, wherein the head portion further comprises one or more grooves disposed in the lateral gap. 6. The toothbrush according to claim 1, wherein at least 80% of the bundle is oriented substantially perpendicular to the flocked surface. 7. A toothbrush according to claim 1, wherein at least N-1 groups of the bundle form a crescent or chevron arrangement. 8. The toothbrush according to claim 3, wherein a crescent-shaped or chevron-shaped apex faces the free end of the head portion.