WO2025237548A1

WO2025237548A1 - Oral care implement

Info

Publication number: WO2025237548A1
Application number: PCT/EP2025/051979
Authority: WO
Inventors: Babu Cherian; Arunima Gupta; Neumesh KOOVALAM PARAMBATH; Biswa Ranjan SWAIN
Original assignee: Unilever Global IP Ltd; Unilever IP Holdings BV; Conopco Inc
Current assignee: Unilever Global IP Ltd; Unilever IP Holdings BV; Conopco Inc
Priority date: 2024-05-17
Filing date: 2025-01-27
Publication date: 2025-11-20
Anticipated expiration: 2026-11-17

Abstract

The present invention discloses a head for an oral care implement. The head in accordance with the invention has an arrangement of bristle tufts on the mounting surface, wherein said mounting surface comprises a central array of tufts in the central zone comprising at least five inner bristle tufts extending radially around a reference point or around a central bristle tuft on the reference point; and one or more peripheral bristle tufts in the peripheral zone. According to the invention, any one of the inner bristle tufts or the central bristle tuft in the central zone occupies no more than 7% of total surface area of the mounting surface and the inner bristle tufts and the central bristle tuft, when present collectively occupy at least 12% of total surface area of the mounting surface. The head according to the invention provides a denser yet flexible central zone which in turn provides better brush movement, soft feel, and efficacious cleaning.

Description

ORAL CARE IMPLEMENT

Field of the Invention

The present invention relates in general to the field of oral care. More particularly, the present invention relates to a head for an oral care implement having an improved bristle pattern.

Background of the Invention

A number of oral care implements with different bristle patterns or arrangement of cleaning elements is known in the art. Different users have different preferences, some prefer harder cleaning while others prefer softer feel of the brush. While feel is important, effective cleaning of plaque, and debris inside the buccal cavity is also important.

In the past, there have been innovations around using different kinds of filaments, different diameters, and around arrangement of bristle tufts on the head. Some of these innovations have been around development of structures in head for better retention of toothpaste for cleaning and polishing teeth.

KR 2005 0117837 discloses a toothbrush head comprising a combination of two moon shaped bundles with a round circular shaped bundle at the front end. It also discloses several oblique hair bundles planted at an angle of 5 to 15 degrees at the front end and a plurality of circular hair bundles centered around a round circular hair bundle at a backward position.

US 2019/000223 A1 discloses a head for oral care implement having filaments with cross shaped cross-sectional area extending in a plane substantially perpendicular to the longitudinal axis having four projections and four channels. It also discloses a low packing factor for tufts with these filaments.

US 2021/0227963 discloses a head with a central bristle tuft and plurality of perimetric bristle tufts that are arranged to circumferentially surround the central bristle tuft.

Despite these, there is still a need to have oral care implements with better bristle configurations and patterns that allow not only good retention of toothpaste on the bristles but also efficacious cleaning. Additionally, the oral care implement should provide a gentle or softer feel when used by consumers. Summary of the Invention

In an aspect, provided is a head (502) for an oral care implement (600), having a distal end (503) and a proximal end (504), said proximal end (504) connected to a handle (501), said head (502) having a mounting surface (510) with a longitudinal axis (AA) running along a length of the handle (501) defining a left side (514) and a right side (515) of the mounting surface (510) and a transverse axis (BB) extending in a plane that is perpendicular to the longitudinal axis (AA), said mounting surface (510) having a central zone and a peripheral zone, said mounting surface (510) comprising:

(i) a central array of tufts in the central zone comprising at least five inner bristle tufts (530), extending radially around a reference point (535) or around at least one central bristle tuft (536) on the reference point (535);

(ii) one or more peripheral bristle tufts (540, 550) in the peripheral zone; wherein any one of the inner bristle tufts (530) or the central bristle tuft (536) in the central array of tufts occupies no more than 7% of total surface area of the mounting surface (510); the central array of tufts occupy at least 10% of total surface area of the mounting surface (510); and the central array of tufts and the peripheral bristle tufts (540, 550) collectively occupy at least 35% of the total surface area of the mounting surface (510).

The head in accordance with the invention allows for effective cleaning of the whole buccal cavity. The claimed arrangement of bristle tufts not only ensures cleaning of the buccal cavity but also a softer feel desired by many consumers. The claimed bristle arrangement has a denser but flexible center which allows for enough movement of the bristles to allow sufficient cleaning as well softer feel on the teeth surfaces.

Brief description of the

Figure 1 is a perspective view of an oral care implement according to one aspect of the invention;

Figure 2 is a top plan showing enlarged view of the head of the oral care implement according to the embodiment of Figure 1;

Figure 3 is a top plan showing enlarged view of a head of an oral care implement according to an alternative embodiment of the invention;

Figure 4 is a top plan showing enlarged view of a head of an oral care implement according to an alternative embodiment of the invention;

Figure 5 is a top plan showing enlarged view of a head of an oral care implement according to an alternative embodiment of the invention; Figure 6 is a top plan showing enlarged view of a head of an oral care implement according to an alternative embodiment of the invention;

Detailed Description of the Invention

As used herein the term “comprising” encompasses the terms “consisting essentially of” and “consisting of’. Where the term “comprising” is used, the listed options or components need not be exhaustive. Unless otherwise specified, numerical ranges expressed in the format "from x to y" are understood to include x and y. In specifying any range of values or amounts, any particular upper value or amount can be associated with any particular lower value or amount. Except in the examples or where otherwise explicitly indicated, all numbers are to be understood as modified by the word “about”. As used herein, the indefinite article “a” or “an” and its corresponding definite article “the” means at least one, or one or more, unless specified otherwise. The various features of the present invention referred to in individual sections above apply, as appropriate, to other sections mutatis mutandis. Consequently, features specified in one section may be combined with features specified in other sections as appropriate. Any section headings are added for convenience only and are not intended to limit the disclosure in any way. The invention is not limited to the embodiments illustrated in the drawings.

Accordingly, features mentioned in the claims if followed by reference numerals, such numerals are included solely for the purpose of enhancing the intelligibility of the claims and are in no way limiting to the scope of the claims. The examples are intended to illustrate the invention and are not intended to limit the invention to those examples per se.

It should be noted that relative terms such as central, center, left, right, corner(s), distal, proximal, a reference point, a central zone, a central array, a peripheral zone, rear, top, front, lateral etc. are merely used to explain relative positions are not intended to be limiting. These relative terms are used for convenience of description only and do not require the device to be constructed in a particular orientation unless otherwise stated. Terms such as ‘attached’, ‘anchored’ ‘connected’, ‘connectable’, ‘mounted’ and similar refer to a relationship where one structure is secured to another both by movable or rigid attachments or relationship, either directly or indirectly and should not be construed as limiting as per the described aspects of the invention.

The present invention describes a head (502) for an oral care implement (600), having a distal end (503) and a proximal end (504), said proximal end (504) connected or connectable to a handle (501), said head (502) having a mounting surface (510) with a longitudinal axis (AA) running along a length of the handle (501) defining a left side (514) and a right side (515) of the mounting surface (510) and a transverse axis (BB) extending in a plane that is perpendicular to the longitudinal axis (AA), said mounting surface (510) having a central zone and a peripheral zone, said mounting surface (510) comprising:

(i) a central array of tufts in the central zone comprising at least five inner bristle tufts (530), extending radially around a reference point (535) or around at least one central bristle tuft (536) on the reference point (535); and

(ii) one or more peripheral bristle tufts (540, 550) in the peripheral zone; wherein any one of the inner bristle tufts (530) or the central bristle tuft (536) in the central array of tufts occupies no more than 7% of total surface area of the mounting surface (510); the central array of tufts occupy at least 12% of total surface area of the mounting surface (510); and the central array of tufts and the peripheral bristle tufts (540, 550) collectively occupy at least 35% of the total surface area of the mounting surface (510).

Oral care implement means and includes all implements for oral care. It is preferred that the implement is a manual toothbrush, electronic toothbrush, powered toothbrush, tongue cleaner or an interdental brush. Depending on the purpose and application of the oral care implement the present invention could be used on the head of any kind of oral care implement. Any kind of handle useful as an oral care implement could be attached to the head of the present invention. When replaceable, the head is usually connected to the handle through a neck partby reversible means. In a preferred aspect, the head, the neck part, the handle part are formed integrally as a single unit.

Referring to Figure 1 , a top view of an oral care implement, particularly a toothbrush (600) is illustrated according to one embodiment of the invention. The toothbrush (600) generally comprises a handle (501) and a head (502). The head (502) has a distal end (503) and a proximal end (504) (not shown in figure 1). The proximal end of the head (504) is the end which is connected or connectable to the handle (501) and distal end (503) is the opposite end. Whilst shown as elliptical in figure 1 , the handle of the oral care implement may have a wide variety of shapes and designs. It may be oval, round, flat, elliptical, or elongated shape.

In the embodiment shown in Figure 1 , the head, the handle part and the neck part are formed together as an integral unit to make the toothbrush (600) using injection molding. In alternative aspects, the handle (501) and the head (502) can also be manufactured separately as components and can be connected at a later stage in manufacturing using any known technique, including but not limiting to thermal welding, sonic welding, a tight-fit assembly, a coupling sleeve, adhesion, or fasteners. Furthermore, other manufacturing techniques may be used in place of and/or in addition to injection molding to create the handle (501) and/or the head (502) (or components thereof), such as milling and/or machining.

Figure 2 is a top plan view showing enlarged front face of the head (502) of the oral care implement (600) according to the embodiment of figure 1. In this figure, shown is a head (502) having a distal end (503) and a proximal end (504), the proximal end connected or connectable to a handle. The head (502) of the oral care implement (600) has a mounting surface (510) and a rear surface (512) (not shown in figures) positioned opposite the mounting surface and one or more lateral surfaces (513). The mounting surface (510) may also be called as front surface, also being on that face of the handle, where the thumb is placed during use. The rear surface is accordingly the face lying opposite. The rear surface of the head may or may not have tongue cleaning elements. The lateral surfaces (513) are the surfaces which are visible when viewed sideways, i.e. , the surfaces appearing in between the mounting surface and the rear surface. A longitudinal axis (AA) runs along the head and in the direction of the length of the handle conceptually demarcating the mounting surface into a left side (514) and a right side (515). Said left and right sides can be interchangeably defined based on how the face is viewed. The longitudinal axis (AA) is a reference line that is generally coextensive with the three-dimensional center line of the handle (501) and the head (502). The axis (AA) may be linear or non-linear. The left side (514) and the right side (515) of the mounting surface can be of any contour or shape and need not necessarily be symmetrical or mirror images. The left side (514) and the right side (515) can also be of any size, with one being larger than the other. A transverse axis (BB) extends in a plane that is substantially perpendicular to the longitudinal axis (AA). The transverse axis BB is equidistant from the distal end (503) and the proximal end (504). The transverse axis BB further conceptually demarcates the mounting surface into a top and a bottom side, where the top side is the one which is on the distal end (503) and the bottom side is on the proximal end (504).

The mounting surface (510) has a central zone and a peripheral zone, each zone comprising a plurality of bristle tufts. Each bristle tuft has bristles or cleaning elements with an anchoring end connected to the mounting surface and an opposite free end.

The reference point (535) is located at a point generally formed by intersection of the longitudinal axis (AA) and transverse axis (BB) of the mounting surface. Such a reference point is in the central zone of the head but it’s exact position may vary depending on the shape of the head. For example, when the head is circular, the reference point (535) may or may not coincide with the center of the circle. In a preferred aspect, when the head or the mounting surface is oval or elliptical in shape, the reference point (535) is formed by intersection of the major axis and minor axis. It can however be slightly away, about 0-20% away from such center or such intersection of major axis and minor axis in all four directions, for example the reference point (535) can be present at a point which is about 0-20% to the left of the center point. In another embodiment, this variation may range from 0-10%, or more preferably 0-5% from the center. It is to be also understood that circular or oval head is only mentioned here as an example and the reference point may be present as per the shape of the head based on similar intersection of lines in AA and BB axis. It is also to be understood that that the reference point is only a position on the mounting surface (no actual point visible or demarcated on the mounting surface) around which the inner bristle tufts extend radially, and bristle tuft may or may not be present on the reference point.

In the embodiment shown in figure 2, the mounting surface (510) shows six inner bristle tufts (530) as an example of at least five inner bristle tufts extending radially around a reference point (535) in the central zone of the mounting surface. These six inner bristle tufts (530) are arranged in a star shaped pattern. For ease of depiction, only two inner bristle tufts are marked in the figure 2 as (530). There are plurality of peripheral bristle tufts in the peripheral zone. Shown as an example in figure 2 are two toe bristle tufts (540), one each located at the distal end (503) and the proximal end (504) and six further bristle tufts (550) located on the outer circumference of the mounting surface (510). Three of these further bristle tufts(550) are located on the left side (514) of the mounting surface and three are on the right side (515) of the mounting surface.

Figure 3 is a top plan view showing the front face of the head of the oral care implement according to another embodiment of the invention. Shown in figure 3 are six inner bristle tufts (530a) extending radially around a central bristle tuft (536) as an example of at least three inner bristle tufts as claimed. The head according to this embodiment has in the peripheral zone, two toe bristle tufts (540a) one each at the distal and the proximal end on the mounting surface. The mounting surface further has six further bristle tufts (550a) arranged on the outer circumference, with three further bristle tufts on the left side and three further bristle tufts on the right side of the mounting surface. The central bristle tuft (536) has a substantially circular or oval shape and the inner bristle tufts (530a) have parabolic or hyperbolic shape with the curve facing towards the outer circumference of the mounting surface. In the figures 2 and 3, two of the further bristle tufts (550, 550a) are present on the on the transverse axis (BB) that extends through the reference point (535) or the central bristle tuft (536).

Shown in figure 4 are inner bristle tufts (530a) extending radially around two central bristle tufts (536x) and (536y) as an example of claimed invention. The head according to this embodiment has two toe bristle tufts (540a), six inner bristle tufts (530a) and six further bristle tufts similar to the arrangement shown in figures 2 and 3. The two central bristle tufts (536x) and (536y) together make a substantially circular or oval shape. The inner bristle tufts (530a) have parabolic or hyperbolic shape with the curve facing towards the outer circumference of the mounting surface.

Figure 5 shows three central bristle tufts (536x), (536y) and (536z) arranged in a manner that together make a substantially circular or oval shape. The head according to this embodiment also shows without limitation six inner bristle tufts (530a), two toe bristle tufts (540a) and six further bristle tufts (550a) similar to those shown in figures 2-4.

Figure 6 shows four central bristle tufts (536x), (536y), (536w) and (536z) arranged in a manner that they together form a substantially circular or oval shape on the reference point (535). The head according to this embodiment also shows without limitation six inner bristle tufts (530a), two toe bristle tufts (540a) and six further bristle tufts (550a) similar to those shown in figures 2-5.

It is to be noted that for ease of understanding, the inner bristle tufts, the toe bristle tufts and the further bristle tufts are marked as (530a) (540a) and (550a) in figures 4-6, but they may not necessarily be of same size, shape and contour as those shown in figure 3 or figure 2. Similarly, no one central bristle tuft may be identical to another central bristle tuft and may be present in varying sizes and shapes.

For ease of depiction, only two inner bristle tufts and three further bristle tufts are marked in the figures 4-6 but a person skilled in the art would understand that there is no limitation with respect to this marking.

Head

The head (502) of the oral care implement (600) includes cleaning elements or bristles either attached directly to the head or through a head plate. While the bristles shown in the figures is suited to be used with a toothbrush, it is to be understood that structural and functional modifications may be made without departing from the scope of the present invention and the invention may be embodied into any kind of oral care implements, for example such as those used to clean oral soft tissue, such as a tongue, gums, or cheeks. The bristles can be connected to the head (502) in any manner known in the art. For example, anchor free tufting (AFT), direct molding or staple technology. In a preferred aspect, the bristles could be mounted to bristle tufts or sections by extending through suitable openings in the bristle tufts or into a head plate with suitable tuft openings and then the head plate could be connected to the head (502) of the toothbrush (600) which is formed as an integral unit with the handle (501).

Covered within the scope is any shape of the head (502). Preferably, the head (502) is elliptical or oval with major axis running along the longitudinal axis (AA) along the length of the handle and minor axis being transverse to the longitudinal axis along the axis (BB).

The mounting surface (510) is the surface of the head on which the bristles are mounted or attached to the head directly or indirectly. The mounting surface (510) can be present directly on the head (502) of the oral care implement or the mounting surface can be on a separate plate attachable to the head of the oral care implement. The bristles are generally anchored to the mounting surface and have an anchored end and an opposite free end. The total surface area of the mounting surface is calculated by calculating the surface area of the base (head or head plate) where tufts are created, or bristles are mounted. Such area is usually measured by commercially available CAD software. The surface area of any one bristle tuft is calculated by measuring the surface area of the shape of the tuft by commercially available CAD software.

The head (502) and the mounting surface (510) are generally of different contours, circular or a shape deviating from circular. The head (502) and the mounting surface (510) are preferably of the same shape, but they can be of different shapes as well. Preferably, the head (502) and the mounting surface (510) are oval or elliptical in shape.

In an aspect, the head or the mounting surface has plurality of bristle tufts ranging from 4 to 35 bristle tufts, preferably from 6 to 30 bristle tufts, more preferably from 10 to 20 bristle tufts. The plurality of bristle tufts comprises inner bristle tufts, central bristle tuft, peripheral bristle tuft(s), and further bristle tuft(s). In addition to these and without limitation, there could be other types of bristle tufts present in the plurality of bristle tufts. Inner bristle tufts

The invention contemplates at least five inner bristle tufts extending radially around a reference point or a central bristle tuft. This radial arrangement either around a reference point or around a central bristle tuft forms a central array of tufts in the central zone. In a preferred aspect, the head according to the invention comprises a central array of tufts comprising at least five inner bristle tufts, more preferably at least six inner bristle tufts, even more preferably at least eight inner bristle tufts.

In another aspect, the head according to the invention comprises from five to twelve inner bristle tufts, preferably six to ten, more preferably five to nine inner bristle tufts, still more preferably six to eight bristle tufts.

Any shape, size and contour of inner bristle tufts (530) in a central array of tufts is within the scope of the invention as long as they are radially present around a reference point or the central bristle tuft(s). The inner bristle tufts can extend radially inwards or outwards. A person skilled would know extending radially generally implies arrangement in a pattern that go out from a central point towards the edge of a circle or oval, but obvious modifications are within the scope of the invention.

In one aspect, the inner bristle tufts (530) are non-circular and elongated in shape. In an aspect, the inner bristle tufts may be triangular shaped with a vertex pointing towards the reference point or the central bristle tuft. In yet another aspect, the inner bristle tufts (530) are elongated oval shaped with one or more pointed vertices. In the embodiment shown in figure 2, three inner bristle tufts (530) are elongated petal shaped, whereas three of them have four unequal edges and rounded vertices, pointing towards the reference point (535). In the embodiment shown in figure 3, the inner bristle tufts (530) have a shape that resembles a parabola or hyperbola, i.e. , having a U-shaped curve or inverted U shape with a vertex pointing towards the outer circumference of the mounting surface and the head. In another aspect, all the inner bristle tufts are of similar shape, preferably elongated with one or more vertices. In yet another aspect, the inner bristle tufts are petal shaped with one or more pointed vertices. In yet another aspect, the inner bristle tufts are diamond shaped.

The inner bristle tufts in a central array of tufts are not necessarily equidistant from the reference point or the centre bristle tuft. In other words, the distance when measured from the reference point (or centre point of the centre bristle tuft) to the point X formed on boundary of any inner bristle tuft, X being the closest to the reference point (or the centre bristle tuft) can vary from one inner bristle tuft to another inner bristle tuft.

The inner bristle tufts in a central array of tufts are arranged around the reference point (535) or the central bristle tuft (536) on the reference point in any kind of arrangement, preferably in a ring or circumferential form. In the embodiment shown in figures 2 and 3, the mounting surface (510) comprises six inner bristle tufts (530, 530a) arranged in a star shaped pattern, extending radially around the reference point (535) or around the central bristle tuft (536). The inner bristle tufts (530, 530a) are called inner bristle tufts as they arise in a central zone however, this does not limit a possibility that some part of the inner bristle tuft touches the outer circumference of the mounting surface or overlap into the peripheral zone.

Central bristle tuft

In one aspect of the invention, the inner bristle tufts (530) extend radially around a central bristle tuft (536), which is optionally present on the reference point (535). The central bristle tuft (536) can be of any shape or contour, preferably, the central bristle tuft (536) is substantially circular or oval. In accordance with the invention, there can also be more than one central bristle tuft. When more than one central bristle tuft is present, such bristle tufts together forming a substantially circular or oval shape around which the inner bristle tufts extend radially. The central bristle tuft (536) when present helps in polishing away surface stains to whiten the teeth.

In one aspect, any one of the inner bristle tufts or the central bristle tuft in a central array of tufts in the central zone occupies no more than 7% of the total surface area of the mounting surface, preferably no more than 6%, more preferably no more than 5%, even more preferably no more than 4%.

In an aspect, any one of the inner bristle tufts (530, 530a) or the central bristle tuft (536) in the central zone occupies about 0.1-7% of total surface area of the mounting surface, preferably about 0.3 to 6%, more preferably about 0.5 to 5%, even more preferably 1% to 5%, still more preferably 1% to 4%.

In another aspect, the central array of tufts collectively occupy at least 10% of the total surface area of the mounting surface (510), preferably at least 12%, more preferably at least 14%, even more preferably at least 15%, still preferably at least 16%, still more preferably at least 17%, still more preferably at least 18%. In another aspect, the plurality of inner bristle tufts and the central bristle tuft when present collectively occupy about 10% to 30% of the total surface area of the mounting surface (510), preferably about 12 % to 25%, more preferably about 14% to 25%, even more preferably about 15% to 25%, still preferably about 16 to 25%, still more preferably about 17 to 23%, still more preferably about 18 to 22%.

A denser central zone helps in better cleaning of the teeth surfaces while the smaller sizes of the inner bristle tufts and the center tuft, when present allows for more flexibility.

In an aspect according to the invention, the inner bristle tufts (530) extend radially around a reference point (535) or the central bristle tuft to form a central array of tufts. One or more such arrays may be present. In a preferred aspect according to the invention, only one such central array of tufts is present on the mounting surface.

The term ‘central array of tufts’ is used to describe the arrangement of inner bristle tufts around the reference point or around a central bristle tuft and by no means should be construed as limiting to the invention.

Peripheral bristle tufts

In accordance with the invention, the mounting surface comprises one or more peripheral bristle tufts (540, 550). In an aspect, the peripheral bristle tufts comprises one or two toe bristle tufts (540) near the distal end and/or the proximal end. In another aspect, the peripheral bristle tufts comprises one or more further bristle tufts (550).

Any shape of peripheral bristle tufts is within the purview of the invention. Preferably, the peripheral bristle tufts are non-circular with at least one angled edge generally taking the shape of the outer circumference of the mounting surface.

In another preferred aspect, two or more peripheral bristle tufts together form a shape matching the outer contour of the mounting surface.

In another aspect, one or more peripheral bristle tufts are elongated with one or more vertices.

In yet another aspect, one or more peripheral bristle tufts are petal shaped with one or more pointed vertices. In yet another embodiment, the peripheral bristle tufts are diamond shaped. It is pertinent to note that the peripheral bristle tufts are called ‘peripheral’ only due to their location on the mounting surface and any two peripheral bristle tufts may or may not be of same shape, size and contour. Any one peripheral bristle tuft does not necessarily be of same shape and cross-sectional area as the other peripheral bristle tuft.

In an aspect of the invention, there is at least one toe bristle tuft, preferably, the toe bristle tuft is at the distal end. Preferably, there are two toe bristle tufts, arranged opposite to each other, one each at the distal and the proximal end.

In a preferred aspect, the outer contour of the mounting surface matches the contour of the head, and the toe bristle tuft is located on the outer circumference of the mounting surface such that it also matches the contour of the head.

In another preferred aspect, the toe bristle tuft at the distal end is slightly pointed towards the distal end to allow better penetration to the teeth located innermost of the jaw.

In a preferred aspect, the toe bristle tuft at the distal end or the proximal end occupies a surface area on the mounting surface which is same as or larger than the surface area occupied by any one of the inner bristle tufts or the central bristle tuft.

In another preferred aspect, the toe bristle tuft is immediately adjacent to at least one inner bristle tuft (530) and immediately adjacent the outer circumference of the mounting surface (510).

More preferably, the toe bristle tuft at the proximal end is immediately adjacent to at least one inner bristle tuft radiating from the reference point or the central bristle tuft towards the proximal end and the toe bristle tuft at the distal end is immediately adjacent to at least one inner bristle tuft radiating from the reference point or the central bristle tuft towards the distal end and both said toe bristle tufts (540) are immediately adjacent the outer circumference of the mounting surface (510).

In the exemplified embodiment, the outer circumference of the front surface (510) of the head (502) is delineated with an oval-shaped line. The outer circumference may accordingly be delineated with boundaries having oval or any other shape according to various embodiments.

By the term “immediately adjacent” means that there are no intervening bristle tufts located between the two elements that are noted as being immediately adjacent. For example, when the toe bristle tuft (540) at the proximal end is immediately adjacent to at least one inner bristle tuft 530 radiating towards proximal end, there are no cleaning elements located between the toe bristle tuft (540) at the proximal end and that inner bristle tuft (530). Similarly, because the toe bristle tuft (540) is immediately adjacent to the outer circumference of the mounting surface (510) of the head (502), there are no cleaning elements located between the toe bristle tuft (540) and the outer circumference of the mounting surface (510) of the head (502). In some embodiments, this applies only to proximal end, only to distal end or both proximal and distal end.

In one aspect, the mounting surface comprises at least two further bristle tufts (550) different from the toe bristle tuft (540) at the distal and/or proximal end. These further bristle tufts (550) are located near the outer circumference of the mounting surface, such that at least one further bristle tuft is located on the left side of the mounting surface and at least one further bristle tuft is located on the right side of the mounting surface.

Preferably, there are at least four further bristle tufts (550), two on the left side and two on the right side of the mounting surface. In a preferred aspect, such further bristle tufts are located at four corners or vertices of the mounting surface (510). Such four further bristle tufts help to reach hard to reach areas of buccal cavity including spaces in between teeth. In a preferred aspect, further bristle tufts (550) are polygonal in shape with one the edges taking shape of the outer contour of the mounting surface. In another preferred aspect, the further bristle tufts (550) are elongated with one or more vertices. In yet another aspect, one or more further bristle tufts are petal shaped with one or more pointed vertices. In yet another embodiment, the further bristle tufts are diamond shaped.

In yet another aspect, the four further bristle tufts (550) are immediately adjacent to at least one inner bristle tuft (530), immediately adjacent to at least one peripheral bristle tuft (540) and immediately adjacent to the outer circumference of the mounting surface (510). In a preferred aspect, the four further bristle tufts (550) are at each corner of the mounting surface such that they intersperse between two inner bristle tufts (530).

As shown in figures 2 and 3, where shape of the head is oval or elliptical or circular, such four further bristle tufts (550) are present at four corners, such that two of the further bristle tufts (550) are located adjacent to the peripheral bristle tuft (540) at the proximal end (504), one on its left and one on its right side and two further bristle tufts (550) are located adjacent to the peripheral bristle tuft (540) at the distal end (503), one on its left side and one on its right side. In another aspect, the mounting surface comprises at least two further bristle tufts located on the same transverse axis that extends through the reference point or the central bristle tuft, one each on the left and right side. Preferably, the two further bristle tufts located on the transverse axis BB that runs through the reference point or the central bristle tufts are polygonal, more preferably triangular with sharp or rounded corners. These further bristle tufts (550) located on the transverse axis BB near the circumference of the mounting surface help in cleaning the gum line.

In one aspect of the invention, the one or more peripheral bristle tufts (540, 550) collectively occupy at least 10% of the total surface area of the mounting surface.

In another aspect, the one or more peripheral bristle tufts (540, 550) collectively occupy from about 10% to 65% of the total surface area of the mounting surface, preferably about 15% to 40%, more preferably about 25% to 40%.

In one aspect, the further bristle tufts (550) collectively occupy at least 10% of the total surface area of the mounting surface, preferably at least 12%, more preferably at least 13% of the total surface area of the mounting surface.

In another aspect, the further bristle tufts collectively occupy from about 10% to 30% of the total surface area of the mounting surface, preferably about 12% to 25%, more preferably about 13% to 25%.

In another aspect, the inner bristle tufts (530), the central bristle tuft (when present) (536) in the central zone and the one or more peripheral bristle tufts (540, 550) in the peripheral zone collectively occupy at least 35% of the total surface area of the mounting surface, preferably at least 40%, more preferably, at least 45% of the total surface area of the mounting surface.

In yet another aspect, the inner bristle tufts (530), the central bristle tuft (when present) (536) in the central zone and the one or more peripheral bristle tufts (540, 550) in the peripheral zone collectively occupy from about 35% to 75% of the total surface area of the mounting surface, preferably about 40% to 65 %, more preferably, about 45% to 60% of the total surface area of the mounting surface.

In the embodiments shown in Figures 2-6, the arrangement of inner bristle tufts and peripheral bristle tufts is generally symmetrical around axis AA, however, non-symmetrical arrangement is also within the purview of the invention. The further bristle tufts on the left side and the right side allows for cleaning of hard-to-reach teeth surfaces as well as cleaning in-between teeth in a gentle way.

In an alternative aspect, the mounting surface (510) comprises bristle tufts arranged in substantially concentric rings, wherein the central bristle tuft (536) if present is the inner most, followed by the inner bristle tufts (530) and followed by the peripheral bristle tuft(s) (540) and further bristle tufts (550). In another aspect, the further bristle tufts (550) are interspersed between the inner bristle tufts (530) and the peripheral bristle tufts (540) such that the further bristle tufts (530) appear partially on the inner most ring of the tufts and partially on the outermost ring on the mounted surface (510).

In another aspect, the further bristle tufts (550) are interspersed between any two radially extending inner bristle tufts (530). The interspersed bristle tufts however may or may not be aligned in the same axis as the inner bristle tufts (530).

Bristles type and material

Any material suitable for making the bristles is within the scope of the invention. In one aspect, the bristles are made from synthetic or natural materials. In an aspect, the bristle material is selected from nylon, polybutylene terephthalate (PBT), polypropylene (PP), Polyethylene terephthalate (PET), Boar bristles, Bamboo fiber bristles, Silicone bristles, polylactic acid (PLA) and/or combinations thereof. The bristles could be of any diameter suitable for making oral care implements. In a preferred aspect, the bristles are made from Nylon or PBT, more preferably a combination of nylon and PBT in different tufts.

Further, any kind of cross section of the bristles is under the purview of the invention. The bristles could be circular or any non-circular in cross-sectional shape. Moreover, the bristles in each of the tufts can be round-end, multi-tip or tapered or a combination thereof. Preferably, the head comprises a combination of two or more kinds of bristles in different tufts. More preferably, one or more or all inner bristle tufts (530) comprise round end or multi-tip bristles and one or more or all peripheral bristle tufts comprise tapered bristles. Even more preferably, one or more or all inner bristle tufts (530) comprise multi-tip, such as tri-tip or tetra-tip bristles whereas one or more or all peripheral bristle tufts and/or one or more or all further bristle tufts comprise tapered bristles. As may be understood by person skilled, the bristle tufts may have bristles of varying or similar lengths. In a preferred aspect, each of the inner bristle tufts in the central zone have bristles of varying lengths as measured from free to anchored ends to form an inclined surface sloping up towards the reference point or the central bristle tuft, when present. In yet another preferred aspect, the inner bristle tufts arranged around the reference point or the central bristle tuft together with the central bristle tuft, if present, collectively forms a dome shaped outer contour when viewed from any side. More preferably, all the inner bristle tufts extending radially from the reference point or from a central bristle tuft collectively form a dome shaped outer contour when viewed from any side. Such an arrangement provides higher cleaning yet gentle feel on the teeth surfaces.

In one aspect, the peripheral bristle tufts have bristles of similar or varying lengths. Preferably the peripheral bristle tufts have bristles of varying lengths as measured from free to anchored ends to form an inclined surface sloping down or sloping up towards the central zone. Preferably, the peripheral bristle tufts form an inclined surface that is sloping towards the central zone of the mounting surface.

As may be understood by a person skilled, bristles are generically called bristles and could also be called alternatively as cleaning elements, filaments, or teeth cleaning elements. Any structure that can be used in head of oral care implements to clean could be called bristles.

Method of manufacture

All parts of the oral care implement, particularly toothbrush according to the invention are either unitarily constructed together from an identical material or constructed separately from different materials. Preferably, the head of the oral care implement is unitarily formed with the handle by injection moulding technique.

The bristles are planted on the head either directly via tufting or through a separately tufted head plate by techniques known in the art such as anchor free technology, PTt (Pressure tufting), staple technology etc. Preferably, the bristle tufts are also made by the injection moulded technology to which the bristles are then mounted via the anchor free or direct staple technology.

Bristles type and material

Any material suitable for making the bristles is within the scope of the invention. In one aspect, the bristles are made from synthetic or natural materials. In an aspect, the bristle material is selected from the group comprising nylon, polybutylene terephthalate (PBT), polypropylene (PP), Polyethylene terephthalate (PET), Boar bristles, Bamboo fiber bristles, Silicone bristles, polylactic acid (PLA) or combinations thereof. Such bristles can also be fibre bristles, rigid bristles, spiral bristles, elastomeric or polymer protrusions, co-extruded filaments, flag or crimped bristles, with or without anti-bacterial compounds and combinations thereof. The bristles could be of any diameter suitable for making oral care implements. In a preferred aspect, the bristles are made from Nylon or PBT, more preferably a combination of nylon and PBT in different tufts.

Further, any kind of cross section of the bristles is under the purview of the invention. The bristles could be circular or any non-circular in cross-sectional shape. Moreover, the bristles in each of the tufts can be round-end, multi-tip or tapered or a combination thereof.

As may be understood by person skilled, the bristle tufts in the central zone and the peripheral zone may have bristles of varying or similar lengths. In one aspect, the inner bristle tufts have bristles of varying lengths such that they form a sloping surface which is sloping upwards towards the reference point or the central bristle in the central zone of the mounting surface. In another aspect, the inner bristle tufts arranged around the reference point or the central bristle tuft together with the central bristle tuft, if present, collectively forms a dome shaped outer contour when viewed laterally. Preferably, the toe bristle tufts have bristles of varying lengths such that they form a sloping surface which is sloping downwards towards the reference point or the central bristle in the central zone of the mounting surface.

As may be understood by a person skilled, bristles are generically called bristles and could also be called alternatively as cleaning elements or filaments. Any structure that can be used in head of oral care implements to clean could be called bristles.

Method of manufacture

All parts of the oral care implement, particularly toothbrush according to the invention are either unitarily constructed together from an identical material or constructed separately from different materials. Preferably, the head of the oral care implement is unitarily formed with the handle by injection molding technique.

The head in accordance with the claimed invention allows for effective cleaning of the whole buccal cavity. The bristles in the bristle tufts in the central zone of the mounting surface effectively clean the teeth surfaces, whereas the bristles in the peripheral bristle tufts allow for better reach to farther teeth and dislodge the plaque.

The present inventors have found that while a denser central zone is efficacious for cleaning, however, having a very large single central tuft reduces flexibility and movement of bristles to clean tooth surfaces. Tooth surfaces are rarely even and flat and therefore a good flexibility of bristles is desirable. In accordance with the claimed invention, any one of the inner bristle tufts or the central bristle tuft in the central zone occupies no more than 7% of total surface area of the mounting surface. Further, the inner bristle tufts and the central bristle tuft, when present collectively occupy at least 10% of total surface area of the mounting surface. This ensures flexibility in the dense central zone due to both size of any individual tuft as well as the radial arrangement of the inner bristle tufts around the reference point or around the central bristle tuft(s). This flexibility improves brushing motion regardless of brushing technique. The flexibility in this central zone also allows gentleness of the brush on the gums, and effective polishing away of the surface stains, ultimately whitening the teeth. While the radially extending inner bristle tufts allow for a denser central zone, the space between any two inner bristle tufts also allows for better cleaning of the brush after each use, in turn reducing the microbial contamination of the head. This in turn reduces need for frequent replacement of the brush and ultimately reducing plastic waste to the environment.

Claims

1. A head (502) for an oral care implement (600), having a distal end (503) and a proximal end (504), said proximal end (504) connected to a handle (501), said head (502) having a mounting surface (510) with a longitudinal axis (AA) running along a length of the handle (501) defining a left side (514) and a right side (515) of the mounting surface (510) and a transverse axis (BB) extending in a plane that is perpendicular to the longitudinal axis (AA), said mounting surface (510) having a central zone and a peripheral zone, said mounting surface (510) comprising:

2. The head (502) according to claim 1 , wherein any one of the inner bristle tufts (530) or the central bristle tuft (536) in the central array of tufts occupies no more than 5% of the total surface area of the mounting surface (510).

3. The head (502) according to claims 1 or 2, wherein the central array of tufts comprises at least six inner bristle tufts (530).

4. The head (502) according to any of claims 1-3, wherein the central array of tufts occupy at least 15% of total surface area of the mounting surface (510).

5. The head (502) according to any of claims 1-4, wherein the one or more peripheral bristle tufts comprises one or two toe bristle tufts (540) near the distal end (503) and/or the proximal end (504).

6. The head (502) according to claim 5, wherein the toe bristle tuft (540) is immediately adjacent to at least one inner bristle tuft (530) and immediately adjacent the outer circumference of the mounting surface (510).

7. The head (502) according to any of claims 1-6, wherein the one or more peripheral bristle tufts comprises one or more further bristle tufts (550) different from the toe bristle tuft (540), preferably at least four further bristle tufts (550), wherein two further bristle tufts are on the left side (514) and two further bristle tufts are on the right side (515) of the mounting surface (510).

8. The head (502) according to any of claims 1-7, wherein the one or more peripheral bristle tufts (540, 550) collectively occupy at least 10% of the total surface area of the mounting surface (510).

9. The head (502) according to any of claims 1-8, wherein the central array of tufts and the one or more peripheral bristle tufts (540, 550) in the peripheral zone collectively occupy at least 40% of the total surface area of the mounting surface (510).

10. The head (502) according to any of claims 1-9, wherein the inner bristle tufts (530) are non-circular in shape.

11. The head (502) according to any of claims 1-10, wherein the mounting surface (510) comprises more than one central bristle tuft (536x, 536y) in the central zone arranged in a manner that forms a substantially circular or oval configuration on the reference point (535).

12. The head (502) according to any of preceding claims, wherein the toe bristle tuft (540) at the distal end (503) or the proximal end (504) occupies a surface area on the mounting surface which is same or larger than the surface area occupied by any one of the inner bristle tufts (530) or the central bristle tuft (536).

13. The head (502) according to any of preceding claims, wherein the peripheral bristle tufts (540, 550) have bristles of varying lengths as measured from free to anchored ends to form an inclined surface sloping down towards the central zone.

14. The head (502) according to any of preceding claims, wherein each of the inner bristle tufts (530) in the central zone have bristles of varying lengths as measured from free to anchored ends to form an inclined surface sloping up towards the reference point (535) or the central bristle tuft (536).

15. The head (502) according to any of the preceding claims, wherein the oral care implement (600) is a manual toothbrush.