U.S. patent application number 13/545660 was filed with the patent office on 2012-11-01 for toothbrush and manufacturing method thereof.
This patent application is currently assigned to BEST HWASUNG CO., LTD.. Invention is credited to Sung-Wook KWON, Young-Jun KWON.
Application Number | 20120272469 13/545660 |
Document ID | / |
Family ID | 47066754 |
Filed Date | 2012-11-01 |
United States Patent
Application |
20120272469 |
Kind Code |
A1 |
KWON; Young-Jun ; et
al. |
November 1, 2012 |
TOOTHBRUSH AND MANUFACTURING METHOD THEREOF
Abstract
A toothbrush includes a head and a plurality of bristles. Each
bristle includes a first end exposed outside the head of the
toothbrush, and a second, opposite end being placed in the head of
the toothbrush. The second ends of the bristles are fused together,
in bundles, to be thermally attached directly to the head of the
toothbrush and/or to define a continuous layer in which at least
some of the bundles are also fused together.
Inventors: |
KWON; Young-Jun; (Paju,
KR) ; KWON; Sung-Wook; (Seoul, KR) |
Assignee: |
BEST HWASUNG CO., LTD.
Paju-si
KR
|
Family ID: |
47066754 |
Appl. No.: |
13/545660 |
Filed: |
July 10, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11586631 |
Oct 26, 2006 |
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13545660 |
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10627913 |
Jul 28, 2003 |
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11586631 |
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Current U.S.
Class: |
15/167.1 |
Current CPC
Class: |
A46B 9/045 20130101;
A46B 2200/1066 20130101; A46D 3/045 20130101; A46D 1/0284 20130101;
A46B 3/04 20130101; A46B 3/06 20130101; A46D 3/005 20130101; A46D
1/0276 20130101 |
Class at
Publication: |
15/167.1 |
International
Class: |
A46B 9/04 20060101
A46B009/04 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 3, 2002 |
KR |
10-2002-76349 |
Claims
1. A toothbrush, comprising: a head; and a plurality of bristles,
each of said bristles comprising a tapered first end exposed
outside the head of the toothbrush, and a second, opposite end
being placed in the head of the toothbrush, wherein the second ends
of the bristles are fused together, in bundles, to be thermally
attached directly to the head of the toothbrush.
2. The toothbrush of claim 1, wherein the head of the toothbrush
further comprises a head insert which comprises opposite first and
second surfaces, and a plurality of through holes extending from
the first surface to the second surface of said head insert; and
each of said bundles comprises several said bristles received in
one of the through holes, with the respective second ends of the
bristles protruding beyond the second surface of the head insert
and defining a fused portion which is larger than a diameter of the
respective through hole and which is thermally attached to the head
insert.
3. The toothbrush of claim 2, wherein several of said bundles are
fused together at the respective fused portions to define a
continuous layer that extends across the respective through holes
in which said several bundles are received.
4. The toothbrush of claim 3, wherein all of said bundles are fused
together at the respective fused portions to define a continuous
layer that extends across all said through holes.
5. The toothbrush of claim 2, further comprising a handle having a
head insert opening in which said head insert is mounted.
6. The toothbrush of claim 1, wherein, said bristles are polyester
resin bristles.
7. The toothbrush of claim 1, wherein each said bristle is tapered
only on said first end thereof and further comprises a first
non-tapered portion positioned between the tapered first end and
the head of the toothbrush; and in each said bristle: the tapered
first end has a length of from 4 mm to 8 mm and a tip thickness of
0.01 mm to 0.08 mm; the first non-tapered portion has a thickness
of 0.1 mm to 0.2 mm along a length thereof; and a total length of
the first non-tapered portion and the tapered first end is from 7
mm to 13 mm.
8. The toothbrush of claim 7, wherein said bristles comprise first
bristles and second bristles; in each of said first bristles, the
tip thickness of the tapered first end is 0.01 to 0.03 mm; and in
each of said second bristles, the tip thickness of the tapered
first end is 0.03 to 0.08 mm.
9. The toothbrush of claim 7, wherein, in each of at least some of
said bristles, the tip thickness of the tapered first end is 0.01
to 0.03 mm.
10. The toothbrush of claim 7, wherein, in each of at least some of
said bristles, the tip thickness of the tapered first end is 0.03
to 0.08 mm.
11. The toothbrush of claim 7, wherein the bristles differ in
length by 1 to 10 mm.
12. The toothbrush of claim 1, wherein each said bristle is tapered
only on said first end thereof, and the tapered first end defines
the entire length of the bristle that is exposed outside the head
of the toothbrush; and in each said bristle: the tapered first end
has a length of 7 mm to 8 mm and a tip thickness of 0.01 mm to 0.08
mm.
13. The toothbrush of claim 2, further comprising: a toothbrush
body; wherein the fused portions of the bundles of the bristles and
the head insert are molded together with the toothbrush body.
14. The toothbrush of claim 1, further comprising: a toothbrush
body having said head; wherein the fused second ends of the
bristles are directly molded together with the head of the
toothbrush body.
15. A tooth brush made by a method comprising the steps of:
inserting a plurality of bristles into each of a plurality of
through holes defined between an upper surface and a lower surface
of a head insert, said lower surface being near to a bottom of the
head insert, each of said bristles defining a non-tapered portion
at a first end and a tapered portion at a second end opposite to
the first end thereof, said non-tapered portion being received into
the through hole; and maintaining the tapered portions of the
bristles outside and away from the upper surface of the head insert
and the non-tapered portion of the bristles to protrude from the
lower surface of the head insert; thermally fusing the non-tapered
portion of the bristles protruding from the lower surface of the
head insert, thereby fixing the bristles to the head insert;
attaching the bottom of the head insert to an upper metal mold;
combining the upper metal mold with a lower metal mold; and
injecting resin into the lower metal mold through an inlet, thereby
attaching the head insert to a head of the toothbrush.
16. A tooth brush made by a method comprising the steps of:
inserting a plurality of bristles into each of a plurality of
through holes defined between a top part and a bottom part of a
lower metal mold, each of said bristles defining a non-tapered
portion at a first end and a tapered portion at a second end
opposite to the first end, said non-tapered portion being received
into the through hole to protrude 2 to 5 mm from the bottom part of
the lower metal mold; and maintaining the tapered portion of the
bristles outside and away from the top part of the lower metal
mold; thermally fusing the protruded non-tapered portion of the
bristles; combining an upper metal mold with the lower metal mold;
and injecting resin into the upper and lower metal molds, thereby
fixing the bristles directly to a head of the toothbrush.
17. A toothbrush, comprising: a head; and a plurality of bristles,
each of said bristles comprising a tapered first end exposed
outside the head of the toothbrush, and a second, opposite end
being placed in the head of the toothbrush, wherein the head of the
toothbrush further comprises a head insert which comprises opposite
first and second surfaces, and a plurality of through holes
extending from the first surface to the second surface of said head
insert; several said bristles are received in each of the through
holes to form a bundles of the bristles, with the respective second
ends of the bristles protruding beyond the second surface of the
head insert and being fused together into a fused portion which is
larger than a diameter of the respective through hole; and at least
some of said bundles are also fused together at the respective
fused portions to define a continuous layer that extends across the
respective through holes in which said at least some bundles are
received.
18. The toothbrush of claim 17, wherein all of said bundles are
fused together at the respective fused portions to define a
continuous layer that extends across all said through holes.
19. The toothbrush of claim 17, wherein the fused portions of at
least some of said bundles are thermally attached to the head
insert.
20. The toothbrush of claim 17, wherein each said bristle is
tapered only on said first end thereof.
21. The toothbrush of claim 17, wherein each said bristle is
tapered only on said first end thereof and further comprises a
first non-tapered portion positioned between the tapered first end
and the head of the toothbrush; and in each said bristle: the
tapered first end has a length of from 4 mm to 8 mm and a tip
thickness of 0.01 mm to 0.08 mm; the first non-tapered portion has
a thickness of 0.1 mm to 0.2 mm along a length thereof; and a total
length of the first non-tapered portion and the tapered first end
is from 7 mm to 13 mm.
22. The toothbrush of claim 1, wherein said bundles have different
shapes selected from the group consisting of rectangle, triangle,
circle, oval, and trapezoid.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation in part of U.S. Ser. No.
11/586,631, filed on Oct. 26, 2006 which is a divisional of U.S.
Ser. No. 10/627,913, filed on Jul. 28, 2003 which, in turn, is
based on and claims priority from Korean Patent Application No.
2002-76349 filed on Dec. 3, 2002. The above listed applications, in
their entirety, are incorporated herein by reference.
BACKGROUND
[0002] 1. Technical Field
[0003] The present disclosure relates generally to a toothbrush and
a manufacturing method thereof.
[0004] 2. Description of the Related Art
[0005] Since the introduction of a toothbrush tufted with tapered
bristles for effective plaque removal and prevention of damage to
gums during teeth brushing, its verified effectiveness has recently
made this toothbrush popular.
[0006] For fabrication of such a traditional toothbrush, 28 to 33
mm long bristles, which are needle-shaped on one end t and
non-needle-shaped on the other end n, are folded over such that the
needle-shaped portion is longer than the non-needle-shaped portion,
as illustrated in FIGS. 1A and 1B. The folded portions are picked
up by means of a cut wire and fixedly inserted into fixing holes in
the head of the toothbrush. The toothbrush manufacturing method is
disclosed in Japanese Patent Open-Laid No. Sho 61-10495.
[0007] As illustrated in FIG. 2, another traditional toothbrush is
made by folding needle-shaped bristles, which are 28 to 33 mm long
and tapered 4 to 8 mm on both ends, in two equal halves and
planting them in the above-described manner. This toothbrush
manufacturing technique is disclosed in Japanese Patent Open-Laid
No. Hei 5-15834.
[0008] In Korea Patent No. 311360, the present inventor disclosed a
toothbrush tufted with ordinary bristles tapered on both ends and
at least one 1 to 10 mm longer bristle 62 of the same shape.
[0009] The above techniques, though they have their own benefits
and drawbacks, commonly boast excellent plaque removal and improved
health of gums.
[0010] The following shortcomings are observed by the present
inventor(s) in terms of one or more of complex manufacturing, high
inferior goods rate, and thus high production cost, for the
following reasons.
(1) In order to shape ordinary polyester bristles into needles, the
tips of the bristles are treated with a chemical such as caustic
soda or sulphuric acid. During this process, the total length and
tapered length of the bristles are difficult to control, thereby
resulting in many inferior bristles. (2) In the case of a today's
popular needle-shaped toothbrush tufted with bristles tapered on
both ends, both tips of the bristles are treated in the
above-described manner, for needle shaping. Even if one tip of a
bristle is successfully tapered, the failure of the other tip leads
to the whole failure of the bristle. (3) There are no appropriate
applications for utilizing bristles having wrong lengths.
[0011] Besides, the traditional toothbrush bristles are planted in
simple patterns and not tightly fixed, as illustrated in FIG. 4. As
a result, the bristles often fall out of the brushes. The cause is
identified that the bristles are folded by half, picked up with a
wire, and pushed into fixing holes 10 by inserting the wire
itself.
SUMMARY
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Several exemplary embodiments of the present invention will
become more apparent from the following detailed description when
taken in conjunction with the accompanying drawings in which:
[0013] FIG. 1A is a side view of a folded 23 to 33 mm long bristle
which is needle-shaped on one end and non-needle-shaped on the
other end, before planting;
[0014] FIG. 1B is a partial enlarged view of bristles as
illustrated in FIG. 1A planted in a toothbrush head;
[0015] FIG. 2 is a side view of a folded 28 to 33 mm long bristle
which is tapered 4 to 8 mm on both ends like needles, before
planting;
[0016] FIG. 3 is a schematic view illustrating a toothbrush tufted
with ordinary both-end tapered bristles and 1 to 10 mm longer
ones;
[0017] FIG. 4 is a plan view of a traditional bristle planting
pattern for a toothbrush;
[0018] FIG. 5 is a side view of a needle-shaped bristle tapered
only on one end according to one or more embodiments of the present
invention;
[0019] FIG. 6 is a perspective view of needle-shaped bristles as
illustrated in FIG. 5 vertically loaded in a cylindrical
container;
[0020] FIG. 7 is a side sectional view of a primary bristle holder
for use in manufacturing a toothbrush according to one or more
embodiments of the present invention;
[0021] FIG. 8 is a side sectional view of a secondary bristle
holder for use in manufacturing the toothbrush according to one or
more embodiments of the present invention;
[0022] FIG. 9 is a side sectional view of a head insert for use in
manufacturing the toothbrush according to one or more embodiments
of the present invention;
[0023] FIG. 10 is a side sectional view of a pusher having
inserting poles matching through holes formed in the primary
bristle holder;
[0024] FIG. 11 is a view illustrating transfer of the needle-shaped
bristles from the primary bristle holder to the secondary bristle
holder and the head insert;
[0025] FIG. 12 is a view illustrating thermal fusion of the
needle-shaped bristles together and/or to the head insert;
[0026] FIG. 13 is a perspective view of a toothbrush handle before
the head insert is attached;
[0027] FIG. 14 is a perspective view of the toothbrush tufted with
the bristles tapered only one end;
[0028] FIG. 15 is a view illustrating attachment of the head insert
to the toothbrush handle by injection molding;
[0029] FIG. 16 is a view illustrating partial thermal fusion of the
bristles;
[0030] FIG. 17A is a schematic top view of bristles thermally
attached to the head insert in accordance with one or more
embodiments, and FIG. 17B is a cross-sectional view taken along
line 17-17 in FIG. 17A;
[0031] FIG. 18A is a schematic top view of bristles thermally
attached to the head insert in accordance with one or more
embodiments, and FIG. 18B is a cross-sectional view taken along
line 18-18 in FIG. 18A; and
[0032] FIG. 19 is a schematic top view showing various bundle
configurations in accordance with an exemplary embodiment.
DETAILED DESCRIPTION
[0033] Several exemplary embodiments of the present invention will
be described herein below with reference to the accompanying
drawings. In the following description, well-known functions or
constructions are not described in detail for the sake of
simplicity.
[0034] As used herein, two originally separate elements are
"thermally fused" or "thermally fused together" or "fused together"
or "fused" when they are joined by melted and then solidified
materials (including but not limited to plastics, especially
polyester) of both elements. The term "fusion" or "thermal fusion"
or "fused portion" means a structure resulted from several elements
being fused together.
[0035] As used herein, two originally separate elements are
"thermally attached" when a melted material (including but not
limited to plastics, especially polyester) of at least one element
adhered to the other element and then solidified. The term "thermal
attachment" means a structure resulted from several elements being
thermally attached with each other. Accordingly, the term
"thermally attached" and "thermal attachment" cover "thermally
fused" and "fused portion" respectively.
[0036] A toothbrush according to one or more embodiments of the
present invention is comprised of one-end tapered bristles formed
of polyester resin to be 13 to 18 mm in total length and 4 to 8 mm
in tapered length. To manufacture the toothbrush, the non-tapered
portions of the bristles are pushed down into through holes
arranged in a planting pattern in a bristle holder. Portions of the
bristles protruding beyond the bottom of the bristle holder are
thermally fused to thereby fix, at least temporarily, the bristles
to the bristle holder. The bristle holder is then attached to the
head of the toothbrush.
[0037] FIG. 5 is a side view of a single needle-shaped bristle 60
which is 13 to 18 mm in length and 4 to 8 mm in tapered length
according to one or more embodiments of the present invention. As
compared to a traditional both-end tapered bristle, the bristle 60
is tapered only on one end and shorter by half with the same
tapered length. The one-end tapering diminishes a bristle failure
rate involved with tapering.
[0038] Since the bristle 60 is planted 5 to 6 mm deep in a
toothbrush head, it is then 7 to 13 mm high from the surface of the
toothbrush head.
[0039] The tapered tip of the bristle 60 is 0.01 to 0.08 mm thick.
The tapered tip thickness is preferably 0.01 to 0.03 mm to allow
the bristles to reach deep between teeth and into gum pockets, and
0.03 to 0.08 mm for thorough cleansing. Both features can be
obtained by planting the two types of bristles in combination, or
grinding bristles by means of a mesh paper (i.e. sandpaper) after
planting, which will be described later.
[0040] In some embodiments, it is preferable to form the bristles
of polyester resin, specifically PET (Polyethylene Terephthalate)
or PBT (Polybuthylene Terephthalate) resin. Other materials, such
as Nylon, acryl, and PP (Polypropylene) resin, are not excluded and
may be used in other embodiments (especially where non-tapered
bristles are used), although such materials are inferior in terms
of water resistance, durability, and strength, and bristles formed
of such a material may be entangled when they are immersed in a
strong acid or alkaline solution, for tapering, resulting in
difficult processing.
[0041] FIG. 6 is a view illustrating the bristles 60 loaded
vertically in a cylindrical plastic container 61. The loaded
bristles 60 are held in a primary bristle holder 20 as illustrated
in FIG. 7, transferred to a secondary bristle holder 30 as
illustrated in FIG. 8, and then transferred to a head insert 50 as
illustrated in FIG. 9. The primary bristle holder 20, the secondary
bristle holder 30, and the head insert 50 include through holes 21
of the same shape. The primary and secondary bristle holders 20 and
30 are formed of a metal, whereas the head insert 50 is preferably
formed of plastic though a metal can be used.
[0042] Since the primary and secondary bristle holders 20 and 30
function to transfer the bristles 60 to the head insert 50, they
are of a metal due to its excellent durability. The head insert 50
is formed of plastic because it is attached to a toothbrush body
70, with the bristles 60 planted therein.
[0043] The bristles 60 are held in the primary bristle holder 20 by
pushing the bristles 60 into the primary bristle holder 20 with a
pusher 40 having inserting poles 41 matching the through holes 21
of the primary bristle holder 20, as illustrated in FIG. 10.
[0044] Referring to FIG. 11, the bristles 60 are then transferred
from the primary bristle holder 20 to the head insert 50 through
the secondary bristle holder 30 by pushing the bristles 60 held in
the primary bristle holder 20 to the secondary bristle holder 30
and then the head insert 50 with the pusher 40, while matching the
through holes 21, in alignment, of the primary and secondary
bristle holders 20 and 30 and the head insert 50. Here, the
non-tapered portions n of the bristles 60 are upward.
[0045] Referring to FIG. 12, the bristles 60 protruding from the
head insert 50 are thermally fused together into one or more fused
portions 135, each of which is directly attached to the head insert
50. Each fused portion 135 includes protruding portions of bristles
60 which have been melted and then solidified into a single body.
While being melted, the protruding portions of the bristles 60 flow
or deform around the respective through holes 21. As a result, the
subsequently formed fused portion 135 is larger than the dimension
of the respective through hole 21, thereby preventing the bundle of
the bristles 60 from falling off the head insert 50 during
subsequent processing.
[0046] In some embodiments, a portion of the head insert 50 is also
thermally fused into one or more fused portions 135 of the bristles
60. That is, while the bristles 60 protruding from the head insert
50 are being melted, the adjacent portion of the head insert 50 is
also melted, at least partially. Upon solidification, the at least
partially melted adjacent portion of the head insert 50 and the
melted portions of the bristles 60 together form a common fused
portion.
[0047] In some embodiments, one or more fused portions 135 bristles
60 and an adjacent portion of the head insert 50 are thermally
attached to each other. That is, while the bristles 60 protruding
from the head insert 50 are being melted, the adjacent portion of
the head insert 50 is not melted. Upon solidification, the melted
portions of the bristles 60 together form a fused portion 135
which, while still in the melted or soften state, adheres to the
adjacent portion of the head insert 50 to form a thermal attachment
with the head insert 50.
[0048] Whether or not the bristles 60 and the head insert 50 are
fused together or are thermally attached depend on the respective
materials of the bristles 60 and head insert 50 as well as on the
conditions, such as temperature, duration, pressure, etc., in the
process disclosed above with respect to FIG. 12. Subsequent
processing and/or packaging and/or use of the tooth brush may
subject the common fused portion or the thermal attachment between
the bristles 60 and the head insert 50 to an appropriate force that
separates the head insert 50 from the fused portion(s) 135.
However, the larger size of the fused portion(s) 135 compared to
the respective through holes 21 prevents the bundle(s) of the
bristles 60 from falling off.
[0049] During the process disclosed above, the length of the
bristles 60 is controllable to some extent. That is, short bristles
60 are thermally fused while they are protruded to a short length,
for example, 1 mm or less, and long bristles 60, while they are
protruded to a long length, for example, about 3 mm. In the case of
very long bristles, they are thermally fused in the above manner
and then their tips are cut, followed by grinding with a mesh
paper. Therefore, an available length range for the one-end tapered
bristles 60 is widened.
[0050] When the bristles differ in length after planting, the tips
of longer ones are cut and ground by a mesh paper. Thus, the length
and tip thickness of the bristles are controlled. In this case,
bristles having a tip thickness of 0.01 to 0.03 mm coexist with
ones having a tip thickness of 0.03 to 0.08 mm. As a result, the
bristles reach deeper between teeth and into gum pockets and clean
the surfaces of the teeth thoroughly.
[0051] To reach deeper into the gum pockets, the bristles can be
planted such that they differ in length by 1 to 10 mm. That is, the
planting of long bristles and short bristles with a 1 to 10 mm
length difference makes the longer ones reach further between teeth
or into gum pockets.
[0052] The head insert 50 having the bristles 60 fixed thereto is
attached to the head of the toothbrush body 70 by one or more of
adhesive, mechanical engagement, ultrasonic bonding or high
frequency bonding.
[0053] Considering product yield, the ultrasonic or high frequency
boding is more preferable. In this case, a head insert opening 51
is preferably formed in the head of the toothbrush body 70, so that
the head insert 50 can be mounted in the head insert opening 51, as
illustrated in FIG. 13. The thus-completed toothbrush is
illustrated in FIG. 14.
[0054] An alternative way of fixing the head insert 50 with the
bristles 60 to the toothbrush body 70 is, as illustrated in FIG.
15, to combine a lower metal mold 90 to an upper metal mold 80 with
the bottom of the head insert 50 fixed thereto, injecting resin
into the lower metal mold 90 through an inlet 91, so that the head
and handle of the toothbrush are integrally formed and at the same
time, the head insert 50 is tightly combined with the toothbrush
head. This fixing method advantageously enables manufacture of
various types of toothbrushes using metal molds for the toothbrush
head and handle of different shapes, increases process efficiency,
prevents introduction of foreign materials due to formation of no
junction gaps, and makes it possible to reduce the thickness of the
toothbrush head, thus allowing easy thorough teeth brushing.
[0055] Another way of planting the bristles 60 in a toothbrush body
is that the non-tapered portions of the bristles 60 are inserted
into through holes in the lower metal mold 90, protruding 2 to 5 mm
from the metal mold 90, these protrusions are thermally fused, an
upper metal mold (not shown) is combined with the lower metal mold
90, and then resin is injected so that the bristles 60 are attached
directly to the toothbrush body, as illustrated in FIG. 16. This
method also offers the benefits that the toothbrush head is
integrated into the toothbrush handle, product yield is increased,
no junction gaps are produced to thereby prevent introduction of
foreign materials, and reduces the thickness of the toothbrush
head.
[0056] In some embodiments, the bristles 60 protruding from the
head insert 50 are thermally fused into fused portions 135 as
exemplarily illustrated in FIGS. 12, 17A, 17B and also denoted in
FIGS. 17A, 17B. Like the embodiment exemplarily illustrated in FIG.
12, the fused portions 135 have a larger diameter than the holes in
the head insert 50, thereby preventing the bundles of bristles 60
from falling off the head insert during subsequent processing. Like
the embodiment exemplarily illustrated in FIG. 12, the fused
portions 135 may or may not be thermally attached to or fused with
the head insert 50, depending on the material of the head insert 50
and/or the fusion temperature of the bristles 60.
[0057] As exemplarily illustrated in FIGS. 17A, 17B, several fused
portions 135 are separated or spaced from each other, while other
fused portions 135 are further fused together into a continuous
layer 136 that extend across, i.e., covers, multiple holes of the
head insert 50. The bundles joined by the continuous layer 136 are
more firmly attached, mechanically and/or thermally, to the head
insert than the other, separated bundles. Thus, the cleaning
effect(s) of the bundles joined by the continuous layer 136 may be
different from the cleaning effect(s) of the other, separated
bundles.
[0058] The formation of the continuous layer 136 depends on various
factors, including but not limited to, the fusion conditions, the
length and material property of the protruding portions of the
bristles 60, the density (i.e., number of holes per unit area) of
the through holes in the head insert 50 etc. By varying one or more
of the disclosed and/or any other factors, the number, position,
size, shape, thickness etc. of the continuous layer 136 can be
varied, resulting in various cleaning effects of the
toothbrush.
[0059] FIGS. 18A and 18B show an embodiment in which all bundles
are fused together into a continuous layer 136 that extend across,
i.e., covers, all holes of the head insert 50. In the particularly
illustrated embodiment, the continuous layer 136 covers the entire
bottom of the head insert 50 and further engages the side walls of
the head insert 50, to more firmly fix the bundles to the head
insert 50.
[0060] In some embodiments, the bristles in the fused portions 135
and continuous layer 136 no longer retain their original shapes and
cannot be separated from each other. In some embodiments, the
thermal attachment of the fused portions 135 and continuous layer
136 with the head insert 50 may be broken, resulting in potential
slight movements of the bundles relative to the head. Such
potential slight movements, if indeed exist, are greatly limited by
the manner the bundles are joined together by the continuous layer
136 (especially in the embodiment disclosed with respect to FIGS.
18A, 18B), and/or by a cover (not shown) that is fit to the head
insert 50 (from above in FIGS. 12, 17B, 18B) to cover the fused
portions 135 and continuous layer 136.
[0061] It should be noted that since thermal attachment or fusion
is used for fixing the bristles 60 to the head insert 50, the
bundles of the bristles 60 is easily configurable to be of any
shape and/or size and/or position and/or bristle density (bundle
strength), thereby permitting various designs of such bundles to be
made with great flexibility in size, shape, position, bristle
density, not to mention length and taperness as disclosed above.
The result is that cleaning effects of the toothbrush can be
enhanced and/or customized as desired. An example of possible
bundle configurations is given in FIG. 19 which is a top view of a
tooth brush in accordance with an exemplary embodiment. In FIG. 19,
bundles 191-196 of various sizes, shapes, positions are included in
a tooth brush. Although shapes such as rectangle, oval, triangle,
trapezoid etc. are depicted any other shapes are within the scope
of the instant application. Further, bundles of the same or similar
shapes are positionable in any desired directions as exemplarily
illustrated at 191 and 192, or have any desired sizes as
exemplarily illustrated at 193 and 194. As noted herein, color,
length, taperness, material, density (number of bristles per unit
area) of bristles 60 are variable from bundle to bundle and/or
within the bundle(s) itself/themselves.
[0062] The above disclosed "free design" feature is hardly
obtainable, if at all, with the known technique of fixing bristles
60 via folding and clipping etc. The reason is that a folded bundle
generally has a symmetrical configuration about the folding line,
and is difficult to fit in holes of certain sizes and shapes (such
as 195, 196 in FIG. 19) which, in turn, may cause the bundle to be
loose or fall off easily. A tooth brush with such loosely fixed
bristles might cause discomfort to the user or can even hurt the
user's gum and tissues in use.
[0063] In contrast, in embodiments of the instant application,
simply by varying sizes, shapes, positions of the through holes 21,
bundles of corresponding configurations are easily obtainable with
numerous advantages discussed herein, e.g., enhanced plaque removal
effects and/or aesthetic appearance (when bundles of multiple
colors and/or shapes are included).
[0064] The structures disclosed above with respect to FIGS. 17A-19
are applicable not only to the method of manufacturing toothbrushes
exemplarily disclosed with respect to FIG. 12, but also to all
other manufacturing methods disclosed herein, especially with
respect to FIGS. 15-16.
[0065] As described above, the toothbrush according to one or more
embodiments of the present invention is tufted with needle-shaped
bristles tapered only on one end, as compared to the traditional
toothbrush having both-end tapered bristles. Therefore, an inferior
goods rate is remarkably dropped and thus product cost can be
reduced by 30% or more.
[0066] However, it is within the scope of the present invention to
provide toothbrushes that, according to some other embodiments, are
tufted with bristles that are not tapered at either end.
Toothbrushes according to further embodiments of the present
invention are tufted with a mix of one-end-tapered bristles and
non-tapered bristles.
[0067] Furthermore, a bristle planting pattern and the number of
the needle-shaped bristles can be freely controlled, thereby
enabling the bristles to clean away hard-to-reach plague. The use
of thermal fusion instead of a cut wire leads to tighter fixing of
the bristles. Even needle-shaped bristles which are failed in
length control can be utilized for fabrication of the
toothbrush.
[0068] Thus, one or more embodiments provide a toothbrush tufted
with needle-shaped and/or non-tapered bristles, which is
manufactured in a simplified process at a diminished failure
rate.
[0069] One or more embodiments provide a method of utilizing
bristles having wrong lengths for manufacture of a toothbrush.
[0070] One or more embodiments provide a method of fixing bristles
more tightly in a toothbrush.
[0071] One or more embodiments provide a method of freely designing
a bristle planting pattern and adjusting the number of bristles for
a toothbrush.
[0072] While exemplary embodiments of the invention have been shown
and described, it will be understood by those skilled in the art
that various changes in form and details may be made therein
without departing from the spirit and scope of the invention as
defined by the appended claims.
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