Note: Descriptions are shown in the official language in which they were submitted.
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18745.1
Product With Bristles
The invention concerns brushware comprising a bristle support
and bristles connected therewith, at least part of which are
combined into bristle groups, wherein the separation between
the bristles is smaller than the separation between the
geometrical centers of neighboring bristle groups.
Brushware in accordance with the invention includes brushes
of any type such as tooth, body, cleaning brushes, applicator
brushes, paint brushes and technical brushes e.g. polishing
and grinding brushes. The bristles of this brushware are
usually combined into groups in the form of bundles or
bristle fields. Brushware is known (EP 0 813 374 = US
5,974,619) having bristle stock formed of individually
standing bristles which are disposed on the bristle support
at small separations from each other.
The free ends of the bristles of the above-mentioned
brushware are usually disposed in a flat envelope surface
which produces good surface action on the surface to be
treated or processed, if this surface is also planar. If the
surfaces are uniformly curved, at least a plurality of
bristles are effective at the same time. If the surface to be
treated or processed has an interrupted curvature or
comprises narrow depressions and gaps, only individual
bristles can penetrate therein in response to application of
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' sufficiently strong pressure. The increased pressure causes
damage to neighboring surfaces.
Attempts have been made to solve this problem by disposing
the free ends of the bristles of one bristle group in a non-
planar envelope surface, with the free ends of bristles in
different groups being optionally disposed in different
envelope surfaces (EP 0 346 846 = US 4,979,782, EP 0 716
821). In this case, the shorter bristles are supported on the
surface to be treated or processed, while the longer bristles
can penetrate into depressions, gaps or the like. This
bristle stock "topography" has shown beneficial effects, in
particular with tooth brushes for reaching the tooth surfaces
of largely different curvatures in the buccal, lingual and
labial region of the oral cavity as well as those of the
interdental spaces and the rugged chewing surfaces of the
molars.
Tooth brushes having such a topography largely permit
satisfactory dental hygiene. However, in particular, the
interdental spaces of the molars are insufficiently cleaned.
This is also the case for pronounced, rugged chewing surfaces
of the molars and the so-called fissures on other tooth
surfaces. Taking this into consideration, a plurality of
individually standing longer bristles would have to be
provided and the length of projection past the residual
bristle stock would have to be correspondingly large. These
projecting bristle ends, without lateral support, wear more
quickly due to friction and also quickly lose their original
,
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' orientation due to the higher bending stress causing them to
bend or even break. The more rapid wear results, in
particular, in irregular wear of the bristle tips which
should be evenly rounded to prevent damage to the tooth
surface and injury of the gingiva.
It is the underlying purpose of the invention to propose a
design for brushes of all kinds, wherein the bristles are
equally effective on both the surface to be treated or
processed as well as in depressions or gaps.
This object is achieved in accordance with the invention in
that the separation of the geometrical center of at least one
bristle group from the geometrical center of at least one
neighboring bristle group is substantially equal to or
greater than the product between the average number of
bristles in the two bristle groups and the average diameter
of these bristles.
With brushware having a plurality of bristles conventionally
arranged in a bundle, the bristles accumulate in the
insertion region of gaps or depressions and only individual
outer bristles of the bundle are capable of deep penetration,
since the number and density of the bristles in the bundle is
large compared to the separation between the bundles. The
bristles cannot deflect sufficiently when sweeping over
depressions or gaps but rather support each other in the
predetermined bundle shape. The invention suggests a
relationship between the bristle number in the bristle
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groups, the bristle diameter and the separations between the
bristle groups which is such that, when sweeping over gaps or
depressions, the bristles can be oriented linearly behind one
another in the brushing direction in consequence of their
length and flexibility. Most or all of the bristles of
bristle groups, disposed one behind the other, can follow the
course of the gap or depression and are equally introduced
therein through the lateral delimitation of the depression.
This occurs, in particular, independent of the shape and
cross-section of the mounting surface of the bristle group.
Moreover, the bristles of the neighboring groups fulfil their
brushing function on the surfaces neighboring the gap or
depression. Brushware in accordance with the invention is
distinguished from conventional brushes in that the
relationship proposed in accordance with the invention
generally results in a smaller number of bristles in a group
and a larger separation between the groups.
The bristle groups designed in accordance with the invention
are preferably formed as bundles having a circular cross-
section. The bristles of a bristle group can also have a
different e.g. triangular, polygonal or strip-like cross-
section, wherein the circular cross-sectional envelope
constitutes the diameter for the inventive relation between
diameter, number of bristles in the bristle groups and their
separation.
Preferably, those bristle groups having a substantially equal
or larger separation between their geometrical centers than
,
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the product between the average number of bristles of
neighboring bristle groups and the average diameter of these
bristles, are disposed on the bristle support in the corners
of a triangle or polygon, in particular of a rectangle,
having optionally different side lengths, with the shortest
side length exhibiting the inventive relationship for the
separation between bristle groups.
Alternatively, the bristle groups whose separations between
their geometrical centers is substantially equal to or larger
than the product between the average number of bristles of
neighboring bristle groups and the average diameter of these
bristles, are linearly disposed on the bristle support.
In this design, the linearly disposed bristle groups can form
a complete bristle stock in several parallel lines or such
linear arrangements may only be provided in regions of the
bristle support. If the brush has a preferred working
direction, this linear arrangement may be optionally provided
in the working direction only. A preferred working direction
obtains e.g. in red/white tooth care, wherein the bristle
head is moved transverse to its longitudinal direction, from
the gums towards the teeth. The same is true for application
brushes of all kinds and with bristles for cleaning profiled
surfaces or surfaces which are interrupted by regular gaps,
depressions or the like, such as e.g. brushes for cleaning
gaps between tile surfaces.
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The number of bristles in the bristle groups can be the same
or differ. The diameters of the bristles in the bristle
groups can also be the same or differ. The separation between
neighboring bristle groups must be adjusted accordingly.
The inventive design of the groups and their arrangement can
also be combined with conventional arrangements in one
individual brushware, e.g. a tooth brush. One combination
comprising individually standing bristles (EP 0 813 347 = US
5,974,619) is particularly effective. The individually
standing bristles can be combined into at least one bristle
field with the bristles being disposed at small separations
from one another. These separations can be on the order of
the bristle diameter.
A further optimization can be achieved when the free ends of
the bristles of at least one bristle group are disposed in a
non-planar envelope surface. This envelope surface can be
convex or concave, wherein conical or partially spherical
envelope surfaces are particularly advantageous.
The free ends of the bristles of different bristle groups can
also disposed in different envelope surfaces, optionally, at
different heights with respect to the surface of the bristle
support.
Basically, the bristles can have any cross-sectional shape or
bristles having a round cross-section can be mixed in one
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bristle group with bristles having other cross-sectional
shapes. If the bristles are not round, the separation between
the bristle groups depends on the diameter of the envelope
circle of the bristle cross-section.
The bristles of a bristle group can be individually connected
to the bristle support or their ends can be connected and
commonly joined to the bristle support. The bristle groups
can be connected to the bristle support through all above-
mentioned mechanical or thermal methods. The use of cassette-
like holding means with a hole pattern corresponding to the
complete bristle stock is recommended, wherein the bristles
and bristle groups are exactly pre-positioned according to
number and arrangement before being connected to the bristle
support using the cassette (EP 0 293 665 = US 4,954,305).
The invention is described below with reference to the
embodiments shown in the drawing.
Fig. 1 shows a section of a bristle field of a
conventional tooth brush having round bristles on a
scale of approximately 10:1;
Fig. 2 shows a section corresponding to Fig. 1 of the
bristle field of a conventional tooth brush, which
comes closest to the invention, on a scale of
approximately 10:1;
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Figs. 3
through 6 show one plan view (a) each onto a bristle group in
the initial position and one plan view (b) each
onto two neighboring bristle groups in the
arrangement in accordance with the invention and
during use;
Fig. 7 shows a plan view onto the chewing surface of
neighboring teeth having an interdental space when
cleaning with a conventional tooth brush;
Fig. 8 shows a side view of the representation in
accordance with Fig. 7;
Fig. 9 shows a plan view onto the chewing surface of
neighboring teeth when using a tooth brush with the
inventive arrangement of the bristle groups;
Fig. 10 shows a side view of the representation of Fig. 9;
Fig. 11 shows a side view of neighboring teeth having
interdental spaces when cleaning with a tooth brush
of conventional design using the red/white method;
Fig. 12 shows a representation according to Fig. 11 when
cleaning with a tooth brush with the inventive
arrangement of the bristle groups;
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Fig. 13 shows, in a highly enlarged scale, a sectional view
of a fissure when using a conventional tooth brush;
Fig. 14 shows a representation in accordance with Fig. 13
when using a tooth brush with the inventive
arrangement of the bristle groups and bristles;
Fig. 15 shows a perspective view of an individual bristle
group in accordance with the invention during
application corresponding to Fig. 14.
The drawing shows only bristle groups in the form of bundles
with circular cross-section and bristles with equally
circular cross-section for reasons of clarity. In the
following description, the bundle diameter is always
characterized with "D", the bristle diameter with "d", the
separation between the bundles with "x", and the number of
bristles with "n". The bundles and bristles must not be round
but can also have a different cross-sectional shape, wherein
the envelope circle of the bundle cross-section has the
diameter D and the bristle cross-section has an envelope
circle of diameter d.
The section of a bristle field of a conventional tooth brush
shown in Fig. 1 consists of bristle groups in the form of
round bundles 1 which consist of a plurality of bristles 2.
The bundles 1 have the diameter D and the bristles 2 the
diameter d. The bundles 1 are mounted at a separation x from
one another on a partially represented bristle support 12.
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Conventional tooth brushes usually have equal separations x
between all bundles in the mounting plane on the bristle
support. Fig. 1 also shows a mechanical mounting method
wherein the bristles 2 of a bundle 1 are looped and mounted
in a hole of the bristle support 12 by means of an anchorage.
This method is called "punching" in brush technology.
In the known tooth brush according to Fig. 1, each bundle 1
contains approximately 42 bristles with a diameter d=0.20mm.
The bundle diameter is D=1.6mm and the separation between the
bundles 1 is x=2.6mm. The filling degree of the bundles
(bristle cross-sectional surface relative to the bundle
surface) is approximately 65s which gives a bristle density
of 791 bristles per cm2.
Fig. 2 shows a conventional arrangement for a tooth brush
having the smallest bundle diameter and the smallest number
of bristles per bundle. Each bundle 1 of this arrangement
comprises n=16 bristles 2 with a diameter d=0.20mm. The
bundle diameter is D=l.Omm and the separation between the
bundles is x=l.6mm. The bristle density is 796 bristles per
cm2 .
If a bristle arrangement in accordance with Fig. 1 or 2 is
moved in a direction parallel to the mounting plane, the
circular cross-section of the bundles 1 is deformed in that
the outer bristles disposed perpendicular to the direction of
motion are displaced towards the rear and the cross-section
of the bundle widens from those bristles advancing in the
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direction of movement towards those bristles trailing with
respect to the direction of movement. This will be described
in more detail below with reference to Figs. 7,8 and 11.
Figs. 3 through 6 show the inventive bristle or bundle
arrangement. Fig. 3a) shows a bundle 1 with a number n=3 of
bristles 2 having a diameter d. The bundle diameter D is
shown with broken lines. The mounting surface of the bundle 1
on the bristle support is also indicated. Fig. 3b) shows this
mounting surface as cross-hatched. The separation between
neighboring bundles is at least x=n~d but can also be larger.
If such a bristle or bundle arrangement is moved in one
direction, the bristles can be aligned in a linear fashion,
one behind the other, and in the brushing direction due to
their length and flexibility, in particular, in response to
resistance from the side (shown in Fig. 3b)).
Figs. 4a) and Fig. 5a) show a bundle 1 with n=4 and n=5
bristles 2. The separation between neighboring bristles is
herein also x>_n~d.
Fig. 6a) shows two neighboring bundles having different
numbers of bristles. The larger bundle 10 (on the left)
comprises a number n=6 of bristles 2, the right smaller
bundle 11 comprises a number n=3 of bristles 2. In this case,
the separation x (Fig. 6b) is calculated from the average
number of bristles (the sum is 9, the average 4.5) and the
bristle diameter d. In this fashion, linear alignment of the
bristles 2 in the brushing direction is also possible for
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bundles having differing numbers of bristles. To prevent
excessive separation between the bundles, the bristle number
per bundle should preferentially be limited for a given
predetermined bristle diameter.
If a linear arrangement of the bristles in accordance with
the invention were intended for the conventional tooth brush
of Fig. 1, the separation x of the bundles would have to be
approximately 8.4mm instead of 2.6mm.
Fig. 7 shows a plan view onto the chewing surface of teeth,
e.g. of the molars. Neighboring teeth are designated with 4
and the interdental space between them with 5. The effect of
a conventional tooth brush is also shown, by way of example,
in the form of three bundles 1 disposed one behind the other
and comprising seven bristles 2 each. The separation x
between the bundles 1 is smaller than the product of the
average number of the bristles 2 of neighboring bundles 1 and
the bristle diameter. If such a bristle arrangement is moved
over the chewing surface of the teeth 4 in the direction of
the arrow 6, the bristles of the advancing bundle 1 will
penetrate into the interdental space 5 but the bristles of
the subsequent bundles will accumulate on the narrow portion
leading to the interdental space 5 (see Fig. 7). The side
view of Fig. 8 shows that the bristles increasingly bend
going towards the trailing bristles and opposite the brushing
direction 6.
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In the inventive arrangement, wherein the separation x is
equal to or larger than the product between the average
number of bristles 2 of neighboring bundles and the diameter
of the bristles, the bristles will not accumulate at the
insertion region of the interdental space 5 during brushing
in direction 6. Rather, the bristles of all bundles are
linearly aligned such that the interdental space 5 is
completely accessed by the bristles in one single brushing
movement in one direction.
The same is true for the red/white method shown in Figs. 11
and 12. In a conventional tooth brush having a bristle
arrangement in accordance with Fig. 11, only individual
bristles of the advancing bundle penetrate into the
interdental space 5 between the teeth 4, as indicated by
brushing direction 6. If the tooth brush is not precisely
guided but slightly inclined, as indicated by brushing
direction 7, still fewer bristles penetrate into the
interdental space 5. In any event, the edge of the gingiva 8
is not reached.
In the inventive arrangement of the bundles 1 in accordance
with Fig. 12, the bristles in the bundles are aligned one
behind the other, independent of the brushing direction 6 or
7 and can thereby penetrate into the interdental space 5 up
to the gingiva edge 8.
Figs. 13 and 14 show a highly enlarged section of a tooth 4
having a fissure 9. Such fissures are usually funnel-shaped
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and have varying longitudinal extensions. In a tooth brush
with conventional bristle arrangement, the bristles 2 of the
bundles 1 engaging into the fissure 9 from above, already
accumulate in the narrowing introductory region of the
fissure 9 while, in the inventive arrangement in accordance
with Fig. 14, at least part of the bristles 2 penetrate to
the bottom of the fissure 9, due to their possible linear
arrangement.
This is clearly shown in the perspective representation of
Fig. 15, which again shows a section of a tooth 4 having an
idealized linear fissure 9. The bristles 2 of the bundle 1
are linearly aligned and, as illustrated, part of the
bristles 2 penetrate to the bottom of the fissure 9.
