Patent Grant
9655435
This invention relates to toothbrushes, in particular to the bristle configuration of toothbrush heads. Especially this invention relates to improved toothbrush bristle configurations comprising tapered bristle filaments.
Toothbrushes are well known articles generally comprising a head for insertion in the user's mouth and a grip handle to be held during use, with a neck region in between. The toothbrush head normally has a surface, termed herein the “bristle surface” from which bristles extend from a lower end of the bristles closest to the bristle surface to an upper end distant from the bristle surface. Toothbrush bristles are also well known articles, generally comprising a filament of a stiff but flexible material, disposed in tufts of plural filaments extending from the bristle surface. The polyamide Nylon is very frequently used as a toothbrush bristle material.
Although in most toothbrushes the bristle filaments have the same cross-section along their entire length from their lower to their upper end except for the extreme upper end which is end-rounded, it is also known to use tapered bristles which decrease in their cross section toward their upper end in a shallow generally conical sloping profile. Tapered bristles, being thinner at their upper end, have different bending and flexibility characteristics to non-tapered filaments. In particular tapered bristles are known for efficacy in reaching into the spaces between the teeth, the so called “interproximal” spaces. For example such bristles are disclosed in EP-A-1 234 525, EP-A-1 415 572, U.S. Pat. No. 6,546,586, WO-A-97/42853, WO-A-97/42854, WO-A-01/32053, WO-A-01/82741, EP-A-0 596 633 among others.
Particular relative dispositions of the tapered bristles on the bristle surface are also known. For example U.S. Pat. No. 6,546,586 discloses a toothbrush head in which each tuft comprises plural bristle filaments made of polybutylene terephthalate in the form of shorter filaments of uniform cross section and longer filaments which taper toward their upper end. It is known to combine tapering and non-tapering bristles on a toothbrush head, e.g. from US-A-2006/0096053 which discloses a head for an electric toothbrush. It is also known from other disclosures to combine long and short bristle filaments in a tuft e.g. U.S. Pat. No. 3,103,679, WO-A-96/16571 and DE-A-35 28 596.
Generally there are two methods of producing such tapered bristles. One method is to chemically erode the ends of the bristle filaments. The other is to mechanically abrade them to a taper. It has previously been found difficult to accurately mechanically abrade bristle filaments in situ on a toothbrush head, particularly to achieve differences in length between tapered and non-tapered bristles. A known toothbrush of the type disclosed in WO-A-96/16571 is known to have been unsuccessful commercially because of poor mouth feel. However recent new mechanical bristle abrasion technologies have opened up new possibilities for exploring variations in length, inclination, tufting patterns etc. of tapered toothbrush bristles, especially in combination with non-tapered bristles.
It is an object of this invention to explore the possibilities of toothbrush heads with combinations of tapered and non-tapering bristles, especially with the intention of providing an improved toothbrush head incorporating tapered bristle filaments, e.g. providing tooth cleaning, particularly in the interproximal spaces, at the gingival margin, in subgingival access, and also having manufacturing advantages. Other objects and advantages of the invention will be apparent from the following description.
According to a first aspect of this invention a toothbrush head is provided having a bristle surface from which extend plural tufts of bristles, said bristles being arranged in plural tufts each of which contains plural bristles, said bristles comprising plural tapered bristles and plural non-tapered bristles, characterized in that said non-tapered bristles extend to two different lengths from the face, being a first greater length LN1 and a second shorter length LN2.
The invention will now be described by way of example only with reference to the accompanying figures.
The term “tapered bristles” is a term of the toothbrush bristle art, a synonym being “pointed bristles” as for example used in US-A-2006/0096053, or “needle shaped bristles” as for example used in EP 1 425 989B. Such “tapered bristles” have a generally conical tapered profile over a substantial part of their length remote from the bristle face, e.g. 10-50% of their length remote from the bristle surface. “Non tapered bristles” are differentiated from such tapered bristles in having a substantially uniform cross section along their length, except that conventionally their extreme ends remote from the bristle surface are rounded to help prevent damage to users' soft tissues by otherwise jagged ends. In the art, bristles which are merely end rounded in this conventional manner are not considered to be “tapered bristles”.
In the toothbrush head of this invention the non-tapered bristles may for example extend to substantially only two discrete lengths LN1 and LN2, so that all of the non-tapered bristles are either only substantially of the length LN1 or LN2, with no continuum of lengths of non-tapered bristles between these two lengths.
In the toothbrush head of this invention the tapered bristles may also for example extend to two different lengths from the face, being a first greater length LT1 and a second shorter length LT2. For example such tapered bristles may extend to substantially only two discrete lengths LT1 and LT2, so that all of the tapered bristles are either only substantially of the length LT1 or LT2, with no continuum of lengths of tapered bristles between these two lengths.
The present invention may be realized in various embodiments.
In one embodiment, one or more of the plural tufts may each comprise plural tapered bristles and plural non-tapered bristles in which the non-tapered bristles extend to two different lengths from the face, being a first greater length LN1 and a second shorter length LN2.
In this embodiment, in such one or more tuft, the tapered bristles may all be of substantially the same length LT, which may be longer than the first greater length LN1 of the non-tapered bristles. Alternatively in this embodiment, within such one or more tuft, the tapered bristles may be of two or more respectively greater and shorter lengths LT1 and LT2, and both LT1 and LT2 may be greater than the first greater length LN1 of the non-tapered bristles.
In another embodiment the tufts on the bristle surface comprises tufts which contain the non-tapered bristles, and in such tufts the non-tapered bristles extend to the two different lengths from the face, being the first greater length LN1 and the second shorter length LN2, and the tapered bristles are contained in tufts discrete from these. Such tufts which contain tapered bristles may contain only tapered bristles.
In this embodiment, in tufts containing tapered bristles the tapered bristles may all be of substantially the same length LT, which may be longer than the first greater length LN1 of the non-tapered bristles. Alternatively in this embodiment, within such one or more tuft containing tapered bristles, the tapered bristles may be of two or more respectively greater and shorter lengths LT1 and LT2, and both LT1 and LT2 may be greater than the first greater length LN1 of the non-tapered bristles.
In another embodiment the tufts on the bristle surface comprises tufts which contain the non-tapered bristles being only of the first greater length LN1, and tufts which contain non-tapered bristles being only of the second shorter length LN2, and the tapered bristles are contained in tufts discrete from these tufts containing non-tapered bristles.
In this embodiment, in tufts containing tapered bristles the tapered bristles may all be of substantially the same length LT, which may be longer than the first greater length LN1 of the non-tapered bristles. Alternatively in this embodiment, within such one or more such tuft, the tapered bristles may be of two or more respectively greater and shorter lengths LT1 and LT2, and both LT1 and LT2 may be greater than the first greater length LN1 of the non-tapered bristles.
In these latter two embodiments one or more tufts containing non-tapered bristles may alternate longitudinally with one or more tufts containing tapered bristles. In the last-mentioned embodiment one or more tufts which contain non-tapered bristles of the first greater length LN1, may alternate longitudinally with one or more tufts which contain the non-tapered bristles of the second shorter length LN2.
In another embodiment the tufts on the bristle surface comprise tufts which contain non-tapered bristles being of the first greater length LN1, and tufts which contain non-tapered bristles of the second shorter length LN2, and such tufts may also contain tapered bristles.
For example in this last embodiment only the tufts which contain non-tapered bristles of the first greater length LN1 may also contain the tapered bristles. Alternatively only the tufts which contain the non-tapered bristles of the second shorter length LN2 may also contain the tapered bristles. Alternatively both the tufts which contain non-tapered bristles of the first greater length LN1 and the tufts which contain the non-tapered bristles of the second shorter length LN2, may also contain the tapered bristles.
For example in this last embodiment the tapered bristles may all be of substantially the same length LT, which may be longer than the first greater length LN1 of the non-tapered bristles. Alternatively in this embodiment, the tapered bristles may be of two or more respectively greater and shorter lengths and such greater and shorter lengths may both be greater than the first greater length LN1 of the non-tapered bristles. Alternatively in this embodiment the tapered bristles may be of two or more respectively greater and shorter lengths LT1 and LT2, and both LT1 and LT2 may be greater than the first greater length LN1 of the non-tapered bristles. For example the difference between LT1 and LT2 may correspond to the difference between LN1 and LN2.
According to a second aspect of this invention a toothbrush head is provided, being connected to or connectable to a toothbrush grip handle to thereby define a head-grip handle longitudinal direction, the head being elongate in the longitudinal direction and having a width direction across the head perpendicular to the longitudinal direction, the head having a bristle surface from which plural tufts of bristles extend, the plural bristle tufts comprising;
at least one first tuft which is inclined in a direction having a longitudinal component at 75-85° to the bristle surface such that the ends of the bristles remote from the bristle surface are longitudinally further from the handle than the ends closest to the bristle surface,
at least one second tuft, widthways distanced from the first tuft, the second tuft being inclined in a direction having a longitudinal component at 75-85° to the bristle surface such that the ends of the bristles remote from the bristle surface are longitudinally closer to the handle than the ends closest to the bristle surface,
wherein in that at least one first tuft and/or at least one second tuft comprises tapered bristles,
and wherein the plural first tufts comprise first tufts having a greater length and first tufts having a lesser length, and the plural second tufts may comprise second tufts having a greater length and second tufts having a lesser length.
In this aspect preferably there are plural first tufts arranged along a line extending with a longitudinal direction component along the bristle surface, and plural second tufts arranged along a line extending with a longitudinal direction component along the bristle surface, the line of first tufts being widthways distanced from the line of second tufts. Such a line may be parallel to the longitudinal direction, at an acute angle to the longitudinal direction, curved, zig-zag or sinuous. Across the width of the toothbrush head there may be plural such pairs of lines of first and second tufts.
In this aspect the respective greater lengths may be the same. The respective lesser lengths may be the same. In this embodiment the greater length of the first and second tufts may be the same, and the lesser length of the first and second tufts may be the same.
In this aspect, in a line of first tufts, individual tufts of the greater length may alternate longitudinally with tufts of the lesser length. Similarly in a line of second tufts, individual tufts of the greater length may alternate longitudinally with tufts of the lesser length. Alternatively, in a line of tufts, individual tufts of the greater or lesser length may alternate longitudinally with two or more tufts of respectively the lesser or greater length. Alternatively, in a line of tufts, two or more tufts of the greater or lesser length may alternate longitudinally with two or more tufts of respectively the lesser or greater length. In this embodiment suitably the length of the tapered bristles is greater than the lesser length of the first and second tufts, preferably greater than the greater length of the first and second tufts.
In this aspect preferably the angle of inclination is 78-82° to the bristle surface. Preferably all of the tufts are inclined at the same acute angle of inclination to the bristle surface, although first and second tufts are inclined in opposite directions.
In a third aspect of this invention the toothbrush head has a bristle surface from which plural tufts of bristles extend, the plural bristle tufts comprising;
at least one first tuft which is inclined in a direction having a longitudinal component at 75-85° to the bristle surface such that the ends of the bristles remote from the bristle surface are longitudinally further from the handle than the ends closest to the bristle surface,
at least one second tuft, widthways distanced from the first tuft, the second tuft being inclined in a direction having a longitudinal component at 75-85° to the bristle surface such that the ends of the bristles remote from the bristle surface are longitudinally closer to the handle than the ends closest to the bristle surface,
the plural first tufts comprise tufts comprising non-tapered bristles having a greater length LN1 and tufts comprising non-tapered bristles having a lesser length LN2,
and at least one first tuft and/or at least one second tuft also comprises tapered bristles.
In this aspect the respective greater lengths LN1 of non-tapered bristles in first and second tufts may be the same. In this embodiment the respective lesser lengths LN2 of non-tapered bristles in the first and second tufts may be the same.
In this aspect individual first tufts including non-tapered bristles of the greater length LN1 may alternate longitudinally with first tufts including non-tapered bristles of the lesser length LN2. Similarly in a line of second tufts, individual second tufts including non-tapered bristles of the greater length LN1 may alternate longitudinally with second tufts including non-tapered bristles of the lesser length LN2.
Alternatively individual first tufts including non-tapered bristles of the greater length LN1 or lesser length LN2 may alternate longitudinally with two or more tufts including non-tapered bristles of respectively the lesser or greater length.
Alternatively, two or more tufts including non-tapered bristles of the greater LN1 or lesser LN2 length may alternate longitudinally with two or more tufts including non-tapered bristles of respectively the lesser length LN2 or greater length LN1.
In this aspect suitably the length LT of the tapered bristles is greater than the lesser length LN2 of the non-tapered bristles preferably greater than the greater length LN1 of the non-tapered bristles.
In an embodiment longer tapering bristles and shorter tapering bristles differ in length by 7 mm or less, e.g. 4 mm or less, for example 2 to 4 mm.
Typically the length to which the shorter tapering bristles extend from the bristle surface is 9+/−1 mm and the length to which the shorter tapering bristles extend from the bristle surface is 13+/−1 mm.
Typically the tapering bristles may be circular in cross section, typically 0.1-0.25 mm, e.g. 0.15-0.20 mm, at maximum. This is a typical standard dimension for toothbrush bristle filaments. In one construction each tuft may contain 2-12 longer tapering bristles, and 20-30 shorter tapering bristles.
It has been found that in a tuft which contains both non-tapering and tapering bristles, 5-7 tapering bristles and 26-28 non-tapering bristles in the tuft is a suitable number for an optimized effect.
It is found that this range of numbers of longer and shorter tapering bristles in the tufts can be advantageous in providing an acceptable mouth feel and in getting the longer bristles in between the teeth. Too few longer bristles may not feel comfortable to the user, too many and it may not be easy to get a larger number of the longer bristles between the teeth.
The longer and shorter tapering bristles may be disposed within tufts in various ways. For example the longer bristles may be disposed predominantly about the central longitudinal axis of the tuft. For example alternatively the longer bristles may be disposed essentially randomly within the tuft.
In the toothbrush head of this invention the tufts comprising tapering bristles may be disposed in various ways on the bristle surface of the head. For example all of the tufts on the toothbrush head may comprise such tufts, and may be disposed in a conventional pattern on the bristle surface. For example such tufts may be disposed in a pattern on the bristle surface of the head in combination with tufts comprising only non-tapered bristles.
Typically the tapering bristles may be made of polyamide, e.g. Nylon, particularly the material Tynex™. This is inter-alia due to the current state of optimization of available machines capable of abrading the ends of bristle filaments to a tapering profile, and the properties of such bristle filament materials as Tynex™.
In a preferred process, the toothbrush head of this invention may be made by a process in which the bristles which are to become tapered bristles are first fixed into the face and the upper ends of the bristles are then mechanically abraded into a tapered shape. Machines able to do such mechanical abrasion are known in the toothbrush manufacturing art.
This fixing may for example be by insertion into tuft socket holes in the face, or by the so-called “anchorless” process in which the bristles are fixed into the hot fluid plastics material of the head during the injection moulding process in which the head is made.
Alternatively bristle filaments may be purchased in an already tapered form. There are two main types of such commercially available tapering bristle filaments.
Double ended bristle filaments are tapered at both ends and are normally mounted in a toothbrush bristle surface by folding them in the middle into a “U” shape and setting the folded middle region of the “U” shape in a socket hole in the bristle surface using a conventional “anchor”. In the toothbrush heads of this invention the tapering and non-tapering bristle filaments may comprise such double-ended filaments, conventionally folded in a “U” shape with the bend of the “U” inserted into the socket hole and retained therein by a conventional metal anchor. In such a construction each length of “U” shaped filament provides two bristles extending from the bristle surface.
Single ended bristle filaments are tapered at only one end and are normally mounted in a toothbrush bristle surface by folding them close to the non-tapered end into a “J” shape and setting the folded end region of the “J” shape in a socket hole in the bristle surface using a conventional “anchor”.
In a further aspect the present invention provides a toothbrush provided with a head as described herein.
The handle and head of the toothbrush of this invention may be made of known materials such as plastics materials and elastomer materials and may incorporate known features. For example the handle may incorporate features which modify the flexibility of the handle, for example the folded region disclosed in EP-A-0336641. For example the connection between the head and handle may be a flexible connection, for example as disclosed in WO-A-97/24949. For example the head of the toothbrush may be divided into flexibly-linked segments for example as disclosed in WO-A-97/07707. For example the connection between the head and handle may be a flexible connection, and the head of the toothbrush may be divided into flexibly-linked segments for example as disclosed in WO-A-98/37788.
The toothbrush of the invention may be a manual toothbrush, i.e. to be brought into contact with the user's head solely by hand action, or the toothbrush may be a power toothbrush in which the bristles of the head are moved by an electric, e.g. battery powered, motor.
In
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In
In
In the embodiments of
In
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In
In
In the embodiments of
In
The first tufts 1241 and second tufts 1242 are arranged in respective lines extending with a longitudinal direction component along the bristle surface 123. Such an arrangement is more clearly shown in the plan view
As seen in
The first and second tufts 1241 and 1242 which contain non-tapered bristles of the greater length LN1 also comprise tapered bristles 125 and these tapered bristles have a length LT greater than the length LN1 of the non tapered bristles therein such that the tapered bristles 125 extend beyond the ends of the non-tapered bristles therein.
As shown in
Longitudinally between the tufts 1241, 1242 of greater length LN1 which contain tapered bristles 125 are shorter tufts of length LN2 which do not contain tapered bristles but only non-tapered bristles.
In the construction shown in
Referring to
Referring to
Referring to
Analogous to
It will be immediately apparent to those skilled in the art that tufts containing tapered bristles may be provided only in the widthways outermost lines of tufts can be provided in other dispositions of tapered bristles e.g. as shown in
For example, referring to
Typically in
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