Note: Descriptions are shown in the official language in which they were submitted.
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TOOTHBRUSH
The invention relates generally to the field of oral care, and in particular
to toothbrushes. More particularly, the invention relates to a toothbrushes
with a three-
dimensional bristle profile to provide improved cleaning of interproximal and
gingival
marginal regions of teeth.
Toothbrushing and flossing are fundamental steps in achieving good oral
hygiene. The practice of flossing, unfortunately, has not met with widespread
acceptance among the general populace even though it is acknowledged by the
general
populace that flossing is something that should be completed as part of good
oral
hygiene. Furthermore, even people who floss oftentimes do not perform adequate
flossing in hard to reach areas of the mouth. Unfortunately, while most
commercially
available toothbrushes clean the outer buccal face of teeth adequately, they
fail to
provide improved cleaning of plaque and debris from the gingival margin, inter-
proximal areas, lingual surfaces and other hard to reach areas of the mouth.
One reason that such toothbrushes do not adequately clean the rear-most
molars (e.g. wisdom teeth or second molars) is that the one or more tufts
secured to
the toothbrush head at a location most distal from the toothbrush handle are
not angled
towards a direction along which the head extends from the handle. As such,
these tufts
cannot extend far enough past the end of the head of the toothbrush to
sufficiently
clean the molar teeth in the back of the mouth.
Additionally, in those brushes having tufts of bristles which angle
towards the handle and other tufts which angle away from the handle, all of
such tufts
are essentially the same length and have the same cross-section. Consequently.
while
these angled tufts may clean one part of the teeth in a satisfactory manner,
other parts
of the teeth will not be cleaned sufficiently due to the homogeneous length,
spacing
and cross-section of the tufts.
Further, prior art toothbrushes disclose tufts of bristles having at most
three different types of cross-sections. However, there are more than three
parts of
the teeth which need to be cleaned by a brush (e.g. the outer buccal face,
gingival
margin, interproximal areas, lingual surfaces and rearward most molars). As
such,
prior art brushes do not provide tufts of sufficiently varied cross-section
specifically
designed to clean all areas of the teeth.
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The present invention is directed to overcoming one or more of the problems
set forth
above. Briefly summarized, according to one aspect of the present invention, a
toothbrush
includes a handle, a head extending from the handle, and a plurality of tufts
of bristles secured
to the head. Three of the tufts are each at an acute angle relative to an
imaginary line which is
tangent to or co-planar with a surface of the head through which the three
tufts are secured to
the head. The three tufts are angled and aligned substantially toward the same
direction, the
direction being substantially parallel with the handle, the direction being
substantially toward
or away from the handle. A first one of the tufts has a length. A second one
of the tufts is
adjacent to the first tuft and has a length shorter than the length of the
first tuft. A third one of
the tufts is adjacent to the first tuft and has a length shorter than the
Length of the first tuft. A
fourth tuft is secured to the head at a location such that no other tuft is
secured to the head at a
location which is more distal from the handle than the location where the
fourth tuft is secured
to the head. The cross-sectional area of the fourth tuft is at least four
times as large as the
cross-sectional area of any other tuft secured to the head.
According to another aspect of the invention, a toothbrush includes a handle,
a head
extending from the handle, and three tufts of bristles secured to the head.
Each tuft is at an
acute angle relative to an imaginary line which is tangent to or co-planar
with a surface of the
head through which the tufts are secured to the head. Two of the tufts differ
in cross-section,
the three tufts being angled and aligned substantially toward the same
direction, the direction
being substantially parallel with the handle, the direction being
substantially toward or away
from the handle. A first one of the tufts has a length. A second one of the
tufts is adjacent to
the first tuft and has a length shorter than the length of the first tuft. A
third one of the tufts is
adjacent to the first tuft and has a length shorter than the length of the
first tuft.
According to a third aspect of the invention, a toothbrush includes a head
with
a frontal free end and a rearward section, a handle connected to the head, and
tufts of bristles
arranged in longitudinal rows on the rearward section of the head, tufts in a
first row being
tilted in a first direction towards the free end of the head, and tufts in a
second row being tilted
towards a second direction opposite the first direction. A further tuft of
bristles secured to the
frontal free end of the head is tilted towards the first direction, the
further tuft having a first
length. The tufts on the rearward section of the head either have the first
length or a second
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length, the first length being longer than the second length. Each
longitudinal row includes
tufts of bristles of the first and second lengths, adjacent tufts in a
longitudinal row having the
first and second length.
These and other aspects, features and advantages of the present invention will
be more
clearly understood and appreciated from a review of the following detailed
description of the
preferred embodiments and appended claims, and by reference to the
accompanying drawings.
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invention will be more clearly understood and appreciated from a review of the
following detailed description of the preferred embodiments and appended
claims, and
by reference to the accompanying drawings.
FIG. 1 is a perspective view of a toothbrush according to the present
invention;
FIG. 2 is a top view of the toothbrush of FIG. 1;
FIG. 3 is a side view of the toothbrush of FIG. 1;
FIGs. 4 and 5 are partial side views of the head and respective portions
of the tufts of the toothbrush of FIG. 1;
FIG. 6 is a partial sectional view of the head of the toothbrush taken
along the lines of 6-6 of FIG. 3; and
FIG. 7 perspective view of the head and a portion of the handle of the
toothbrush of FIG. 1.
Beginning with FIGS. 1-3, a toothbrush 10 includes a handle portion 12
and a head portion 14 which extends from the handle in a direction D. The
overall
length of toothbrush 10 is preferably about 7.7 inches while the width of head
14 at its
widest portion is preferably about 0.5 inches. A main portion 16 of handle 12,
and
head 14 are made of a unitary piece of polypropylene. Remaining portions of
handle
12, including thumb gripping portion 18, optional Trademark 24 (preferably
about .83
inches long) and finger gripping portion 20 are preferably made of a
thermoplastic
elastomer, preferably kraton rubber (a hydrogenated or unhydrogenated oil
filled block
co-polymer of styrene and butadiene or isoprene having a shore A hardness of
between
about 5 and about 70). Thumb gripping portion 18 and a portion of finger
gripping
portion 20 have a series of seventeen raised ribs 22 which aid in the
gripability~ of the
handle. Ribs 22 are preferably .OS inches in width.
With reference to FIGs. 3-7, a plurality of tufts 26 of bristles are
secured to head 14 of the toothbrush. Each tuft is made up of a large number
of
bristles, and all of the bristles are preferably end-rounded. There are five
different
types of tufts secured to the head each tuft type having a cross-section which
differs in
both area and shape to the other tuft types.
A first type of tuft, type 28, is made up of bristles formed of poly-
butylene-terephthalate (PBT) with an abrasive such as kaolin clay particles
mixed
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throughout the PBT. These bristles are between about .005 to .009 inches in
diameter,
preferably .007 inches in diameter. The length of these bristles. measured
from surface
30 of head 14, is about .440 inches. The cross-sectional tufted area for tuft
28 is about
0.0373 square inches, providing a tuft volume measured from the head surface
of about
S .0164 cubic inches (preferably this volume is between about .O1 ~ and .018
cubic
inches). There is only one type 28 tuft secured to head 14 and it is located
more distal
from handle 14 than any other tuft.
A second type of tuft, type 32, is made up of nylon IndicatorsT"'' type
bristles which are formed of 6.12 nylon and colored blue on their external
surface. As
is well known in the art, the blue coloring on these bristles is slowly worn
away as the
brush is used over time to indicate the extent to which the toothbrush is
worn. These
bristles are between about .005 to .009 inches in diameter, preferably .007
inches in
diameter. The length of these bristles, measured from surface 30 of head 14,
is about
.350 inches. The cross-sectional area of each tuft 32 is about 0.0045 square
inches.
As shown in FIG. 6, type 32 tufts have a round cross-section. There are
between 8
and 12 type 32 tufts secured to head 14.
A third type of tuft, type 34, is made up of bristles formed of PBT with
an abrasive such as kaolin clay particles mixed throughout the PBT. These
bristles are
between about .005 to .009 inches in diameter, preferably .007 inches in
diameter.
The length of these bristles, measured from surface 30 of head 14. is about
.440
inches. The cross-sectional area of each tuft 34 is about 0.0027 square
inches. There
are between eight and twelve type 34 tufts secured to head 14. As shown in
FIG. 6,
type 34 tufts are rectangular in shape with rounded ends.
A fourth type of tuft, type 36, is made up of bristles formed of ~PBT
with an abrasive such as kaolin clay particles mixed throughout the PBT. These
bristles are between about .005 to .009 inches in diameter, preferably .007
inches in
diameter. The length of these bristles, measured from surface 30 of head 14,
is about
.440 inches. The cross-sectional area of each tuft 36 is about 0.0040 square
inches.
There are between four and six type 36 tufts secured to head 14. As shown in
FIG. 6,
type 36 tufts are rectangular in shape with rounded ends, and are wider across
the head
than type 34 tufts.
A fifth and final type of tuft, type 38, is made up of bristles formed of
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PBT with an abrasive such as kaolin clay particles mixed throughout the PBT.
These
bristles are between about .005 to .009 inches in diameter, preferably .006
inches in
diameter. The length of these bristles, measured from surface 30 of head 14,
is about
.350 inches. The cross-sectional area of each tuft 38 is about 0.0084 square
inches.
There are between four and six type 38 tufts secured to head 14. As shown in
FIG. 6,
type 36 tufts are rectangular in shape with rounded ends, and are wider than
type 36
tufts.
Based on the cross-sectional areas of the various tufts described above,
tuft type 28 has a cross-section which is more than four times as large as any
other tuft
secured to head 14. Although specific materials were described above from
which the
bristles of each tuft are made, other materials can be used. As such, any of
the bristles
attached to head 14 could be made from, for example, PBT with or without an
abrasive such as kaolin clay, 6.12 nylon with or without an abrasive, or nylon
Indicator'"' material with or without an abrasive.
Additionally, the bristles within a tuft and between tufts can have
varying lengths, diameters, cross-sectional shapes, cross-sectional areas,
colors and be
made of differing materials.
As best seen in FIGS. 2, 4 and 5 and seven, all of the tufts on head 14
are angled either towards direction D or towards the direction opposite of
direction D
by preferably less than about 81 degrees, more preferably between about 69
degrees to
about 81 degrees. and most preferably by about 75 degrees, relative to an
imaginary
straight line 40 which is tangent to surface 30 of head 14. If surface 30 was
flat,
rather than curved, then line 40 would be co-planar with surface 30. Two outer
rows
of tufts 42 are angled towards direction D away from handle 12. An inner rovi~
of tufts
44 are angled opposite direction D towards handle 12 with the exception of
large tuft
28 which is tilted towards direction D away from handle 12.
Toothbrush 10 can be made by the following process which is generally
understood by those skilled in the art. Each of the tufts of bristles are
formed by
gathering together a desired amount of bristles of a selected material, length
and
diameter. The tufts are then inserted into apertures in part of a mold of an
injection
molding machine. An end of the tuft which is or will project into the mold
cavity is
then melted to join the bristles together in a fused mass or ball at that end
of the tuft.
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The mold part bearing the tufts is then joined with another portion of the
mold which
together define a cavity used to form main portion 16 of the toothbrush. The
fused
masses of the tufts are located just within the cavity.
Polypropylene is then injected into the cavity to form portion 16 of
toothbrush 10. The polypropylene is then cooled at which point the partially
finished
toothbrush is moved to a second injection molding station. The cooled,
hardened
polypropylene secures the fused masses of the tufts to head 14 of the
toothbrush. At
the second molding station, the partially finished brush is put into a second
mold
having cavities to form the thumb gripping portion 18, trademark 24 and finger
gripping portion 20. A thermoplastic elastomer is then injected into the mold
after
which the elastomer is cooled and finished toothbrush 10 is removed from the
mold.
The toothbrush is then packaged.
