Note: Descriptions are shown in the official language in which they were submitted.
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HEAD FOR AN ORAL CARE IMPLEMENT
FIELD OF THE INVENTION
The present disclosure is concerned with a head for an oral care implement and
in
particular with such a head comprising at least one tuft having filaments of
different types.
BACKGROUND OF THE INVENTION
Tufts composed of a plurality of filaments for oral care implements, like
manual and
powered toothbrushes are well known in the art. Generally, the tufts are
attached to a mounting
surface of a head intended for insertion into a user's oral cavity. A grip
handle is usually
attached to the head, which handle is held by the user during brushing. The
head is either
permanently connected or repeatedly attachable to and detachable from the
handle.
It is known that filaments forming one tuft often have substantially the same
dimensions
and characteristics. While toothbrushes comprising these types of tufts clean
the outer buccal
face of teeth adequately, they are not as well suited to provide adequate
removal of plaque and
debris from the gingival margin, interproximal areas, lingual surfaces and
other hard to reach
areas of the mouth.
Tufts composed of two different types of filaments, so called tuft-in-tufts,
are also known
in the art. In general, each type of filament is arranged in a group, wherein
an inner group is
substantially coaxially enclosed by an outer group to form the tuft. For
example, a toothbrush
head is known having a bristle surface from which tufts comprising plural
filaments extend in a
filament direction. Each tuft comprises shorter filaments having a cross
section which does not
taper from their lower end toward their upper end and longer filaments which
taper from their
lower end toward their upper end. The longer bristles are surrounded by the
shorter bristles.
The tuft-in-tufts known in the art, in particular the longer filaments located
in the central
region of the tuft, show substantially isotropic bending stiffness. However,
on the one hand, a
relatively low bending stiffness results in reduced efficiency of interdental
cleaning performance,
and, on the other hand, in case the bending stiffness is relatively high, a
risk may occur to injure
the gums of the user.
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It is an object of the present disclosure to provide a head for an oral care
implement
which provides improved cleaning properties, in particular with respect to
intc.Tproximal and
gingival marginal regions of teeth. It is also an object of the present
disclosure to provide an oral
care implement comprising such head.
SUMMARY OF THE INVENTION
In accordance with one aspect, a head for an oral care implement is provided
that
comprises:
- at least one tuft extending from a mounting surface of the head and
having an outer lateral
area,
- the tuft comprising a first group of filaments defining a first lateral
area, and at least a
second group of filaments defining a second lateral area,
- the filaments of the first group having a first length and the filaments
of the second group
having a second length, the first length being different from the second
length, wherein
- the outer lateral area of the tuft is composed of at least a section of the
first lateral area
and of at least a section of the second lateral area.
In accordance with one aspect, an oral care implement is provided that
comprises such
head.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is described in more detail below with reference to various
embodiments
and figures, wherein:
Fig. 1 shows a top view of a first example embodiment of a tuft;
Fig. 2 shows a top view of a second example embodiment of a tuft;
Fig. 3 shows a top view of a third example embodiment of a tuft;
Fig. 4 shows a top view of a fourth example embodiment of a tuft;
Fig. 5 shows a top view of a fifth example embodiment of a tuft;
Fig. 6 shows a perspective view of the tuft of Fig. 1;
Fig. 7 shows a side view of one of the tufts of Fig. 1 to 4;
Fig. 8 shows a side view of one of the tufts of Fig. 1 to 4;
Fig. 9 shows a side view of one of the tufts of Fig. 1 to 4;
Fig. 10 shows a perspective view of the tuft of Fig. 1;
Fig. 11 shows a schematic top view of a first embodiment of an oral care
implement;
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Fig. 12 shows a schematic top view of a second embodiment of an oral care
implement;
Fig. 13 shows a schematic top view of a third embodiment of an oral care
implement;
Fig. 14 shows a schematic front view of the oral care implement of Fig. 13;
Fig. 15 shows a schematic side view of the oral care implement of Fig. 13;
Fig. 16 shows a schematic perspective view of the oral care implement of Fig.
13; and
Fig. 17 shows detail I of Fig. 16.
DETAILED DESCRIPTION OF THE INVENTION
A head for an oral care implement in accordance with the present disclosure
comprises at
least one tuft which extends from a mounting surface of the head and has an
outer lateral area. In
the context of this disclosure the term "outer lateral area" means the outer
lateral surface of the
tuft excluding the base/bottom and the top surface of the tuft. The tuft may
have a circular or
non-circular cross-section (the cross-section being perpendicular to length
extension of the tuft)
and is defined by its outer lateral area. For example, the cross-sectional
shape can be ellipsoid,
squared, rectangular, triangular, cross-shaped, or it can be a prolate
ellipsoid with flattened long
sides, even though other shapes may be considered as well. The cross-section
of the tuft may
have a width from about 2 mm to about 4 mm and a depth from about 2 mm to
about 4 mm.
The tuft comprises a first group of filaments which have a first lateral area,
and at least a
second group of filaments which have a second lateral area. The first group
and the second
group of filaments are arranged in a manner that each of the groups forms at
least a portion of the
outer lateral area of the tuft, i.e. both groups are exposed with their first
and second lateral area,
respectively, to the outer surface of the tuft. Thus, at least one section of
the first lateral area and
at least one section of the second lateral area form at least a portion of the
outer lateral area of the
tuft. In other words, the first group of filaments is partially surrounded by
or partially abuts on
the second group of filaments. Neither the first nor the second group of
filaments is completely
surrounded by the respective other group.
The filaments of the first group have a first length and the filaments of the
second group
have a second length which is different to the first length. The length of a
filament is defined by
the extension of the filament measured from its lower end being secured at the
mounting surface
of the head to its upper free end.
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In other words, the tuft is composed of at least two types of separated/single
or isolated
filaments which differ in terms of length and which are arranged in respective
groups. In the
context of this disclosure, a "group of filaments" means at least 10 single
filaments having
substantially the same length. In some embodiments, the group of filaments
having the shorter
length comprises at least three times the number of filaments of the other
group having the
greater length.
In the present context, the term "substantially" refers to an arrangement of
elements or
features that, while in theory would be expected to exhibit exact
correspondence or behavior,
may, in practice embody something slightly less than exact. As such, the term
denotes the degree
by which a quantitative value, measurement or other related representation may
vary from a
stated reference without resulting in a change in the basic function of the
subject matter at issue.
The filaments of greater/increased length may assure access to narrow spaces
and are able
to penetrate into the gaps between teeth and remove plaque and other residues
more effectively.
In order to clean the teeth effectively during brushing, appropriate contact
pressure has to
be provided between the free end of the tuft and the teeth. Generally, the
contact pressure
depends on the bending stiffness and the displacement of the filaments, while
the bending
stiffness of a single filament depends on the length of the filament, the
diameter of the filament
and the Young' s-modulus of the filament material. The bending stiffness CF of
a single filament
is defined by:
3 EJ
13
with E = Young's modulus, J= moment of inertia, 1= length of the filament,
while for a
cylindrical filament
7t A.
64
For an entire tuft with n filaments the bending stiffness CT of the tuft is
approximately given by
the sum over the bending stiffness of the filaments of the tuft:
37r E d4
CT =1CF =1--
64 13
n n
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Generally, filaments with greater length show lower bending stiffness compared
to
filaments having a shorter length. In order to compensate said reduction in
bending stiffness, the
diameter of a filament could be increased. However, relatively long and
relatively thick
5 filaments may injure the gums or may cause damages to the soft tissues of
the oral cavity.
In order to overcome this drawback the tuft in accordance with the present
disclosure has
a group of filaments with increased/greater length but with identical diameter
(in case cylindrical
filaments are used) to provide better penetration of said filaments into
interdental spaces. In
order to provide sufficient bending stiffness of these filaments at least in
one direction, the group
of filaments having the greater length abuts on the other group of filaments
having the shorter
length. The bending stiffness of the group of greater filaments is higher in
the direction where
the group of greater filaments abuts on the group of shorter filaments and
vice versa, i.e. the
bending stiffness of the group of greater filaments is lower in the direction
where the group of
shorter filaments does not surround/abut on the group of longer filaments. In
other words, the
group of greater filaments show higher bending stiffness in the direction
where they are
supported by the group of shorter filaments as the shorter filaments have to
bend away when the
longer filaments are bend in the direction toward the shorter filaments ¨ the
group of shorter
filaments act like a counterforce. In case the group of longer filaments is
bend in a direction
where said group does not abuts on the group of shorter filaments, the group
of shorter filaments
does not support the longer filaments. The group of shorter filaments does not
act as a
counterforce and, thus, the bending stiffness in said direction is lower.
The resulting bending stiffness of the group of filaments having greater
length is defined
in a first direction x (longer filaments abut on shorter filaments) and in a
second direction y
(longer filaments do not abut on shorter filaments) by:
37r E clt 137r E cl
+ o4
CTX =ICFi + CFO = --
64 /3 64 /3
n, no n, no
37r E
CTy CF, = 1 4
n, n,
while index i indicates the longer filaments and index o indicates the shorter
filaments.
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In other words, the group of filaments having greater length shows anisotropic
bending
stiffness. The different groups of filaments act like a stapled leaf spring by
adding up their
individual bending stiffness to the resulting overall bending stiffness of the
tuft. Therefore,
regular or thin filaments can be used in an interior part of the tuft in order
to access and clean
narrow interdental spaces when the head of the oral care implement is moved
forward and
backward on the occlusal, buccal and lingual surfaces of the teeth. Due to the
anisotropic
bending stiffness of the group of filaments having a greater length, better
cleaning effects can be
provided.
In some embodiments, the tuft may be arranged on the mounting surface of the
head in a
manner that higher bending stiffness is provided in a brushing direction where
the risk of injury
to gums is relatively low, like in a direction parallel to the longitudinal
extension of the head in
order to clean the occlusal, buccal and lingual surfaces of the teeth with
higher force in a forth
and back movement (x-direction). Lower bending stiffness may be provided in a
direction
orthogonal to the longitudinal extension of the head (y-direction) in order to
provide a more
gentle brushing when the head is moved from the teeth to the gums and vice
versa. In other
words, the bending stiffness is higher in the direction x along the occlusal,
buccal and lingual
surfaces of the teeth, while the bending stiffness is lower when the tuft is
moved in a sideward
direction y, i.e. between the teeth and the gums and vice versa. The lower
bending stiffness in
the sideward direction y may reduce the risk of injury of gums and/or other
soft tissues of the oral
cavity. In other words, the tuft of the head for the oral care implement may
ensure high cleaning
performance for forth and back movement while the lower bending stiffness in
the sideward
direction y may protect the gums.
Each of the different groups of filaments may have a specific
topography/geometry at its
free ends, i.e. at their upper top surfaces, which may be shaped to optimally
adapt to the teeth
contour. For example, at least one group of filaments may have a topography,
i.e. an upper top
surface which is chamfered or rounded in one or two directions, pointed or
formed linear.
The filaments may be made of nylon with or without an abrasive such as kaolin
clay,
polybutylene terephtalate (PBT) with or without an abrasive such as kaolin
clay and/or from
nylon indicator material colored at the outer surface. The coloring on the
nylon indicator
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material is slowly worn away as the filament is used over time to indicate the
extent to which the
filament is worn.
Optionally, the head for the oral care implement may further comprise at least
one
thermoplastic elastomer element for cleaning and/or massaging the teeth and/or
soft tissues of the
oral cavity. The thermoplastic elastomer element may be made up of a unitary
structure or of a
number of substructures. For example, the thermoplastic elastomer element may
comprise a
large unitary bristle, i.e. a nub, or a number of smaller bristles. The
thermoplastic elastomer
element may also comprise a fin, cup, like a prophy cup, or a curved or
straight wall.
In some embodiments the first length of the first group of filaments is
greater than the
second length of the second group of filaments. The difference in length
between the first and
the second length may be from about 1 mm to about 3 mm, optionally from about
1 mm to about
2 mm, further optionally about 1.5 mm. The length of the shorter filaments
measured from the
mounting surface to their upper free ends may be from about 8 mm to about 12
mm, optionally
from about 10 mm to about 11 mm, further optionally about 10.5 mm.
In some embodiments, the tuft further comprises at least a third group of
filaments having
a third lateral area. Thus, the tuft comprises at least three groups of
filaments, wherein at least
the first and the second group differ in terms of length. The filaments of the
third group may
have a length which is equal to the first or second length, or the filaments
of the third group may
have a third length which is different to the first and second length. The
first group of filaments
is neither completely enclosed by the second nor by the third group of
filaments. This provides a
tuft for a head for an oral care implement having a group of filaments with
greater length for
cleaning interdental areas while the bending stiffness of this group can be
adjusted in different
directions. For example higher bending stiffness can be provided in a brushing
direction along
the longitudinal extension of the head, i.e. for brushing the occlusal, buccal
and lingual surfaces
of the teeth, and a lower bending stiffness in an orthogonal direction
thereto, i.e. for brushing in a
sideway direction from the teeth to the gums and vice versa.
In some embodiments, the outer lateral area of the tuft is composed of at
least one section
of the first lateral area of the first group of filaments, at least one
section of the second lateral
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area of the second group of filaments and at least one section of the third
lateral area of the third
group of filaments. In some embodiments, the first group of filaments having
longer filaments is
sandwiched between the second and the third group of filaments. The term
"sandwiched" shall
mean that the first group of filaments is centrally located and forms at two
opposite sides the
outer lateral surface of the tuft. In some embodiments, the filaments of the
third group have a
third length being substantially equal to the second length of the second
group of filaments. The
first group having a greater length may form a wiping element which may be
aligned orthogonal
to the longitudinal direction of the head, i.e. across the width of the head.
In the context of this
disclosure, the term "wiping element" is directed to a section of the first
group of filaments
which projects above the upper top surfaces of the second and third group of
shorter filaments.
This protruding section may flap in different directions during the brushing
process thereby
wiping over the teeth. In some embodiments, the wiping element has a
rectangular or oval cross-
sectional shape in order to facilitate penetration of the longer filaments
into interdental areas.
While the wiping element is designed to reach deeply into the interdental
areas, the groups of
shorter filaments are designed to clean the occlusal, buccal and lingual
surfaces of the teeth when
the head of the oral care implement is moved forward and backward, i.e. in a
forward and reverse
direction x. In said forward and reverse direction x, the longer filaments
abut on the outer
filaments of the second and third group, respectively. Thus, the group of
filaments having a
greater length shows higher bending stiffness when the oral care implement is
moved along its
longitudinal axis and lower bending stiffness when the oral care implement is
moved sideward,
i.e. orthogonal to the longitudinal axis.
Alternatively, the first group of filaments being centrally located does not
extend
completely through the cross-section of the overall tuft. In other words, the
outer lateral area of
the tuft is composed of one connected section of the first lateral area of the
first group of
filaments, one connected section of the second lateral area of the second
group of filaments and
one section of the third lateral area of the third group of filaments. Such an
arrangement of
filaments provides increased anisotropic bending stiffness in several
directions.
In addition or alternatively, the group of filaments having the greater length
may have a
first bending stiffness in a first direction x and a second bending stiffness
in a second direction y,
the first direction x being substantially orthogonal to the second direction y
and the first bending
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stiffness is higher than the bending stiffness. In addition, the first
direction x of the first bending
stiffness may be substantially parallel to the longitudinal extension of the
head.
In some embodiments, the cross-section of the first group of filaments (the
cross-section
being perpendicular to length extension of the group of filaments) has a width
from about 2 mm
to about 4 mm, optionally about 3.5 mm and a depth from about 0.6 mm to about
0.8 mm,
optionally about 0.7 mm. This relatively small depth may ensure deep
penetration of the longer
filaments into narrow, hard to reach areas between the teeth while the
relatively great width may
ensure that the longer filaments clean the teeth in the interdental area over
their width.
In addition or alternatively, the filaments of the greater length may be
tapered filaments
having a pointed tip. Tapered filaments may achieve optimal penetration in
areas between two
teeth as well in gingival pockets during brushing and may provide improved
cleaning properties.
In some embodiments, the tapered filaments may have an overall length
extending above the
mounting surface of about 10 mm to 16 mm and a tapered portion of about 5 mm
to 10 mm
measured from the tip of the filament. The pointed tip may be needle shaped,
may comprise a
split or a feathered end. The tapering portion may be produced by a chemical
and/or mechanical
tapering process.
In addition or alternatively, the filaments of the first group and the
filaments of the second
group may further differ from each other at least in one of the following
characteristics: diameter,
bending stiffness, material, texture, cross sectional shape, color and
combinations thereof. The
filaments may be crimped, notched, dimpled, flocked or may comprise a series
of ribs, for
example. Textured filaments tend to enhance cleaning effects on the teeth. The
filaments may
have a circular or non-circular cross-section, in particular the filaments may
have a diamond-
shaped cross-section, triangular cross-section or a cross-section that can be
described as a prolate
ellipsoid with flattened long sides. Further, the filaments may be flagged at
their free ends or
may also be hollow. The filaments may be made up from nylon with or without an
abrasive such
as kaolin clay, from polybutylene terephtalate (PBT) with or without an
abrasive such as kaolin
clay or from nylon indicator material colored at the external surface. The
coloring on nylon
indicator material is slowly worn away as the filament is used over time to
indicate the extent to
which the filament is worn. The filaments may have a diameter from about 0.1
to about 0.3 mm,
optionally from about 0.15 mm to about 0.2 mm. Optionally, the filaments of
the third group
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may also differ from the filaments of the first and/or second group at least
in one of the
characteristics cited above.
In addition or alternatively, the at least one tuft may be inclined with
respect to the
5 mounting surface of the head. In other words, the at least one tuft may
be oriented at an angle a
relative to that portion of the mounting surface of the head from which it
extends. The tuft is
angled relative to an imaginary line which is tangent to or co-planar with the
mounting surface of
the head through which the tuft is secured to the head. The at least one tuft
may be oriented at an
angle a in a direction that is substantially parallel to the longitudinal
extension of the head and/or
10 orthogonal thereto, i.e. across the width of the head. In some
embodiments, one or more tufts are
tilted in the direction that is substantially parallel to the longitudinal
extension of the head. The
at least one inclined tuft may have better cleaning properties, in particular
with respect to
interdental areas, as the inclination of the tuft facilitates that the longer
filaments may slide into
small gaps between the teeth to clean the interdental areas, while the shorter
filaments may clean
the occlusal, buccal and lingual surfaces of the teeth. In some embodiments,
the head comprises
a plurality of tufts, wherein at least one tuft is angled in a direction
toward the handle and at least
one tuft is angled in a direction away from the handle. The cleaning
efficiency is even further
improved if more than one row of angled tufts is consecutively arranged.
Further, the tufts can
also be oriented at two or more different angles a and can also be angled in
different directions
such as along the length of the head, across the width of the head or part way
between the length
and the width of the head.
The inclination angle a between the tuft and the mounting surface of the head
may be
from about 45 to about 89 , optionally from about 60 to about 85 , further
optionally from
about 65 to about 83 , even further optionally from about 70 to about 80 ,
even further
optionally from about 72 to about 78 , even further optionally about 74 ,
about 75 or about
76 .
In addition or alternatively, the tuft may be attached to the head by means of
a hot tufting
process. One method of manufacturing the oral care implement may comprise the
following
steps: In a first step, tufts are formed by providing a desired amount of
filaments. In a second
step, the tufts are placed into a mold cavity so that ends of the filaments
which are supposed to be
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attached to the head extend into said cavity. The opposite ends of the
filaments not extending
into said cavity may be either end-rounded or non-end-rounded. For example,
the filaments may
be not end-rounded in case the filaments are tapered filaments having a
pointed tip. In a third
step the head or an oral care implement body comprising the head and the
handle is formed
around the ends of the filaments extending into the mold cavity by an
injection molding process,
thereby anchoring the tufts in the head. Alternatively, the tufts may be
anchored by forming a
first part of the head ¨ a so called "sealplate" ¨ around the ends of the
filaments extending into
the mold cavity by an injection molding process before the remaining part of
the oral care
implement is formed. Before starting the injection molding process the ends of
the tufts
extending into the mold cavity may be optionally melted or fusion-bonded to
join the filaments
together in a fused mass or ball so that the fused masses or balls are located
within the cavity.
The tufts may be held in the mold cavity by a mold bar having blind holes that
correspond to the
desired position of the tufts on the finished head of the oral care implement.
In other words, the
tufts attached to the head by means of a hot tufting process are not doubled
over a middle portion
along their length and are not mounted in the head by using an anchor/staple.
The tufts are
mounted on the head by means of an anchorfree tufting process.
The oral care implement may be a toothbrush comprising a handle and a head
according
to any of the embodiments described above. The head extends from the handle
and may be either
repeatedly attachable to and detachable from the handle or the head may be non-
detachably
connected to the handle. The toothbrush may be an electrical or a manual
toothbrush.
The following is a non-limiting discussion of example embodiments of tufts and
oral care
implements in accordance with the present disclosure, where reference to the
Figures is made.
Fig. 1 shows a top-down view of a first example embodiment of a tuft 10 for a
head 12,
13, 19 of an oral care implement 14, 15, 17 as shown in Fig. 11 and 13 to 17.
The tuft 10
comprises three groups of filaments 16, 18, 20, wherein the filaments of the
first group 16 are
longer than the filaments of the second and third group 18, 20. The first
group 16 is sandwiched
between the second and third group 18, 20. The first group 16 has a first
lateral area 24, the
second group 18 has a second lateral area 26 and the third group 20 has a
third lateral area 28.
The outer lateral area 22 of the tuft 10 is composed of two sections 72, 74 of
the first lateral area
24 of the first group 16, one section 76 of the second lateral area 26 of the
second group 18 and
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one section 78 of the third lateral area 28 of the third group 20. A section
80 of the second lateral
area 26 of the second group of filaments 18 abuts on a section 82 of the first
lateral area 24 of the
first group of filaments 16 whereas a section 84 of the third lateral area 38
of the third group of
filaments 20 abuts on another section 86 of the first lateral area 24 of the
first group of filaments
16. The cross sectional shape of tuft 10 is elliptical with flattened sides.
These flattened sides
are provided by a rectangular shape of the first group 16 of filaments whereas
the second and
third group 18, 20 have a semicircular shape. This arrangement of filaments
provides a first
group of filaments 16 with anisotropic bending stiffness properties revealing
the advantages
described above. The bending stiffness of the tuft 10 is indicated by arrow 56
in the x-direction
and by arrow 58 in the y-direction. As illustrated in Fig. 1, the bending
stiffness is higher in the
x-direction (longer filaments abuts on the shorter filaments) than in the y-
direction (longer
filaments do not abut on the shorter filaments).
Fig. 2 shows a second example embodiment of a tuft 30 which differs from the
first example embodiments of tuft 10 in that the first group of filaments 16
has a cross-sectional
width which is wider than that of the first example embodiment of tuft 10. The
width of the first
group of filaments 16 extends beyond the width of the cross-sectional area of
the second and
third group 18, 20. The cross-sectional shape of the first group 16 has a
depth which is below the
diameter of a standard tuft and a width which is larger compared to a standard
tuft. This
relatively small depth may ensure deep penetration of the longer filaments
into narrow, hard to
reach areas between the teeth while the relatively great width may ensure that
the longer
filaments clean the teeth in the interdental area over their width.
Fig. 3 shows a third example embodiment of a tuft 32 which differs from the
first
example embodiment of tuft 10 in that the cross-sectional shape of tuft 32 is
rectangular.
Fig. 4 shows a fourth example embodiment of a tuft 34 similar to the first
example
embodiment of a tuft 10. However, the first group of filaments 16 does not
reach completely
through the cross section of the overall tuft 34. Thus, the outer lateral area
22 of tuft 34 is
composed of one section 72 of the first lateral area 24 of the first group of
filaments 16, one
section 76 of the second lateral area 26 of the second group of filaments 18
and one section 78 of
the third lateral area 28 of the third group of filaments 20. This arrangement
of filaments further
enhances the anisotropic bending stiffness behavior of the first group of
filaments 16. The
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bending stiffness is indicated by arrow 60 in the +x-direction, by arrow 62 in
the +y-direction
and by arrow 64 in the opposite -y-direction. As shown in Fig. 4, the bending
stiffness in
direction +y is lower than in the opposite direction -y whereas the bending
stiffness in direction
+x is higher than in direction +y. Such tufts can be arranged on the
toothbrush head at an outer
region of the field of tufts.
Fig. 5 shows a fifth example embodiment of a tuft 36 which differs from the
third
example embodiment of tuft 32 in that tuft 36 comprises only a first and a
second group of
filaments 16, 18, both groups forming a rectangular cross-sectional shape.
Such an arrangement
creates strong anisotropic bending stiffness properties of the first group of
filaments 16. The
longer filaments of the first group 16 abuts on the shorter filaments of the
second group 18 in one
direction only, namely in the opposite direction of direction x. The bending
stiffness is indicated
by arrow 66 in the +x-direction, by arrow 68 in the opposite direction -x and
by arrow 70 in the
+y-direction. The bending stiffness in direction +x is lower compared to the
opposite direction
-x. The bending stiffness in direction +y is higher than in direction +x and
lower than in the
opposite direction -x. If tuft 36 is moved in direction +x the longer
filaments will be supported
by the shorter filaments. The higher bending stiffness forces the longer
filaments to penetrate
into interdental gaps and other narrow spaces. If tuft 36 is moved in the
opposite direction -x the
longer filaments show lower bending stiffness as they are not supported by the
shorter filaments
and, thus, the loner filaments can gently move over the teeth surface without
creating a stuttering
effect.
Figs. 6 and 10 show two different geometries of the first group of filaments
16 which may
be implemented into tuft 10 of Fig. 1. The first group of filaments 16 may
have the form of a
wiping element 38 as illustrated in Fig. 6 or may have the form of a fin 40 as
shown in Fig. 10.
The second and third group of filaments 18, 20 may have the same length and
may have a
semicircular cross-section. These tufts 10 may be adapted to the teeth
contour.
Figs. 7 to 9 show side views of tufts 10, 30, 32, 34 of Figs. 1 to 4.
According to Fig. 7,
the first group 16 consists of filaments having greater length whereas the
second and third group
18, 20 consist of shorter filaments each having the same length. The tuft
according to Fig. 8 is
similar to the tuft shown in Fig. 7, however the upper top surface of the
second and third group
18, 20 are chamfered at the outer region of the tuft. The tuft according to
Fig. 9 is also similar to
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14
the tuft shown in Fig. 7, however the filaments of the second group 18 are
greater compared to
the filaments of the third group 20. Further, the upper top surface of the
second group 18 shows
a slightly curved profile at the outer region of the tuft and the upper top
surface of the third group
20 is slanted at the outer region of the tuft. These tufts 10, 30, 32, 34 may
be adapted to the teeth
contour.
Fig. 11 shows an oral care implement 14, which could be a manual or an
electrical
toothbrush 14 comprising a handle 42 and a head 12 extending from the handle
42 in a
longitudinal direction. A plurality of tufts 10, 34 are secured to the head 12
by means of a hot
tufting process. The tufts 10, 34 extend from a mounting surface 44 of the
head 12. The head 12
comprises two different example embodiments of tufts, namely the first example
embodiment of
tuft 10 illustrated in Fig. 1 and the fourth example embodiment of tufts 34
outlined in Fig. 4. The
first example embodiment of tufts 10 are arranged in a central portion of the
mounting surface 44
and the fourth example embodiment of tufts 34 are arranged along the outer
longitudinal edge of
the mounting surface 44 of the head 12. Tufts 10 are secured to the mounting
surface 44 in a
manner that the extension of the first group of filaments 16 is orthogonal to
the longitudinal
extension 46 of the head 12. Thus, the bending stiffness of the first group of
filaments 16 is
higher in the direction of the longitudinal extension 46 of the head 12 than
in the direction
orthogonal thereto.
Tufts 34 are also secured to the mounting surface 44 in a manner that the
extension of the
first group of filaments 16 is orthogonal to the longitudinal extension 46 of
the head 12. Further,
the section 72 of the first lateral area 24 of the first group of filaments 16
comprised by the outer
lateral area 22 of the tuft 34 faces the central part of the mounting surface
44, i.e. this section 72
of the first lateral area 24 faces tufts 10.
Toothbrush 14 having this arrangement of tufts 10, 34 may provide high
interdental
cleaning capabilities. The longer filaments of the first group 16 penetrate
into interdental spaces
when the toothbrush 14 is moved back- and forward. Generally, the longer
filaments of the first
group 16 do not reach the gums, however in case of contact, they may bend away
due to reduced
bending stiffness in a brushing direction from the teeth to the gums. Gums and
other soft tissues
are protected from getting injured by the longer filaments.
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The head 13 of a toothbrush 15 shown in Fig. 12 comprises five different types
of tufts
36, 48, 50, 52, 54 secured on the mounting surface of the head 13.
In the toe region at the distal end of the head 13, i.e. furthest away from
the handle 42,
5 one crescent-shaped tuft 48 is attached to the head 13. The crescent-
shaped tuft 48 is angled by
about 810 or less to an imaginary line which is tangent to or co-planar with
the mounting surface
44 of the head 13 through which the crescent-shaped tuft 48 is secured to the
head 13. The
crescent-shaped tuft 48 is tilted away from the handle 42. The crescent-shaped
tuft 48 extends
past the end of the head 13 of the toothbrush 15 and, thus, may clean molars
(e.g. wisdom teeth
10 and second molars) in the back of the oral cavity in a more sufficient
manner. In some
embodiments, the crescent-shaped tuft 48 is made up of filaments formed of PBT
with an
abrasive such as kaolin clay particles mixes throughout the PBT. In some
embodiments, the
crescent-shaped tuft 48 has a cross-section which is at least four times as
large as any other tuft
36, 50, 52, 54 secured to the head 13.
Along the outer longitudinal edge of the head 13 there are two further types
of tufts 50, 52
arranged in an alternating manner. These types of tufts 50, 52 are angled
toward the handle 42
relative to an imaginary line which is tangent to or co-planar with the
mounting surface 44 of the
head 13. Tufts 50 have a rectangular cross-sectional shape with rounded ends.
Tufts 50
comprise filaments which may be formed of PBT with an abrasive, such as kaolin
clay particles
mixes throughout the PBT. There are between six to twelve tufts 50 secured to
the mounting
surface 44 of the head 13. Tufts 52 have a circular cross-sectional shape and
comprise filaments
which may consist of a nylon indicator material. In some embodiments, these
filaments are blue
colored on their external surface. The color is slowly worn away as the
toothbrush is used over
time to indicate the extent to which the filaments are worn. There are between
six to twelve tufts
52 secured to the mounting surface 44 of the head 13.
Moreover, three to six tufts 36 of Fig. 5 are arranged in a central row along
the
longitudinal extension 46 of the head 13 between tufts 50 and 52. Tufts 36 are
angled in a
direction away from the handle 42 and are arranged in a manner that the first
group of filaments
16 are oriented orthogonal with respect to the longitudinal extension 46 of
the head 13. In some
embodiments, these tufts 36 are made of PBT with an abrasive, such as kaolin
clay particles
mixes throughout the PBT. Between crescent-shaped tuft 48 and tuft 36 a single
further tuft 54 is
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secured on the mounting surface 44. Said tuft 54 is similar to tuft 36,
however tuft 54 is merely
composed of filaments having the same length in order to avoid that filaments
of tuft 48 and 36
intermingle during a forward and backward motion of the toothbrush 15.
The tufts 36, 48, 50, 52, 54 attached to the head 13 of Fig. 12 may have an
inclination
angle a between the respective tuft 36, 48, 50, 52, 54 and the mounting
surface 44 of the head 13
of about 45 to about 89 , optionally from about 60 to about 85 , further
optionally from about
65 to about 83 , even further optionally from about 70 to about 80 , even
further optionally
from about 72 to about 78 , even further optionally about 74 , about 75 or
about 76 .
In a forward motion of the toothbrush 15 the longer filaments of the first
group 16 of tufts
36 are supported by the shorter filaments of the second group 18 resulting in
higher bending
stiffness. The higher bending stiffness helps to drive the longer filaments of
the first group 16
deeply into narrow spaces. On a backward motion the bending stiffness of the
longer filaments is
lower and, thus, the longer filaments of the first group 16 may gently move
over the teeth surface
without creating a stuttering effect.
The toothbrush according to Fig. 12 may provide improved removal of plaque and
debris
from the gingival margin, interproximal areas, lingual surfaces, the outer
buccal face and
rearward molars.
The head 19 of the toothbrush 17 according to Figs. 13 to 17 comprises three
different
types of tufts 10, 48, 52. The first type of tuft 10 (first example
embodiment) is illustrated in
Figs. 1 and 6. The other type of tufts 48, 52, namely the crescent-shaped tuft
48 and tuft 52 are
the same as described with respect to Fig. 12. The crescent-shaped tuft 48 is
secured in the toe
region at the distal end of the head 19, i.e. furthest away from the handle
42. A first row of first
example embodiment of tufts 10 alternating with tufts 52 is arranged in the
central part of the
mounting surface 44. All tufts 10, 52 of the first row are angled toward the
handle 42. A second
and a third row of first example embodiment of tufts 10 alternating with tufts
52 are arranged on
each side of the first row and are angled in the opposite direction, i.e. away
from the handle 42.
Each tuft 10 of the first row alternate with one tuft 52. Each tuft 10 of the
second and third row
alternate with two tufts 52, except of the last tuft 10 proximal to the handle
42 which alternate
only with one tuft 52.
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The first example embodiment of tufts 10 are arranged on the mounting surface
44 of the
head 19 in a manner that the first group of filaments 16 extends orthogonal to
the longitudinal
extension 46 of the head 19. Consequently, the first group of filaments 16
shows a higher
bending stiffness when the toothbrush 17 is moved along its longitudinal
extension and a lower
bending stiffness when the toothbrush 17 is moved orthogonal thereto, i.e.
from the teeth to the
gums and vice versa. This may ensure higher cleaning performance for forth and
back
movement while the lower bending stiffness in the sideward direction ensures a
protection of the
gums.
The tufts 10, 48, 52 attached to the head 19 according to Figs. 13 to 17 may
have an
inclination angle a between the respective tuft 10, 48, 52 and the mounting
surface 44 of the head
19 of about 45 to about 89 , optionally from about 60 to about 85 , further
optionally from
about 65 to about 83 , even further optionally from about 70 to about 80 ,
even further
optionally from about 72 to about 78 , even further optionally about 74 ,
about 75 or about
76 .
The dimensions and values disclosed herein are not to be understood as being
strictly
limited to the exact numerical values recited. Instead, unless otherwise
specified, each such
dimension is intended to mean both the recited value and a functionally
equivalent range
surrounding that value. For example, a dimension disclosed as "40 mm" is
intended to mean
"about 40 mm."
