U.S. patent application number 11/722488 was filed with the patent office on 2010-03-11 for toothbrush brushhead for a power toothbrush with angled bristles.
This patent application is currently assigned to KONINKLIJKE PHILIPS ELECTRONICS N.V.. Invention is credited to William Bryant, Joseph W. Grez, Scott Hall.
Application Number | 20100058548 11/722488 |
Document ID | / |
Family ID | 36215468 |
Filed Date | 2010-03-11 |
United States Patent
Application |
20100058548 |
Kind Code |
A1 |
Grez; Joseph W. ; et
al. |
March 11, 2010 |
TOOTHBRUSH BRUSHHEAD FOR A POWER TOOTHBRUSH WITH ANGLED
BRISTLES
Abstract
The brushhead, which has a rotating action, includes a bristle
plate and three separate sets of bristle tufts. A first set of
bristle tufts extends longitudinally down the approximate center of
the brushhead and is arranged to extend vertically from the base
plate. The second and third sets of bristle tufts are arranged on
opposing sides of the first set of bristle tufts, with the second
and third sets of bristle tufts being arranged at an angle
outwardly, in opposing directions, from the first set of bristle
tufts, the angle being in the range of 5.degree.-45.degree.. The
length of all the bristle tufts is established so that the tips of
the bristles in the first, second and third sets of bristle tufts
form a shallow arc.
Inventors: |
Grez; Joseph W.; (North
Bend, WA) ; Bryant; William; (North Bend, WA)
; Hall; Scott; (Issaquah, WA) |
Correspondence
Address: |
PHILIPS INTELLECTUAL PROPERTY & STANDARDS
PO BOX 3001
BRIARCLIFF MANOR
NY
10510-8001
US
|
Assignee: |
KONINKLIJKE PHILIPS ELECTRONICS
N.V.
EINDHOVEN
NL
|
Family ID: |
36215468 |
Appl. No.: |
11/722488 |
Filed: |
December 21, 2005 |
PCT Filed: |
December 21, 2005 |
PCT NO: |
PCT/IB2005/054363 |
371 Date: |
November 30, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60638227 |
Dec 22, 2004 |
|
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|
Current U.S.
Class: |
15/22.1 |
Current CPC
Class: |
A46B 9/04 20130101; A46B
2200/1066 20130101; A61C 17/22 20130101 |
Class at
Publication: |
15/22.1 |
International
Class: |
A46B 13/00 20060101
A46B013/00 |
Claims
1. A brushhead for a power toothbrush in which the brushhead is
driven in a side-to-side motion, comprising: a brushhead base
plate; a plurality of lateral rows of bristle tufts, each row
comprising: a first set of bristle tufts set into the base plate
substantially vertically; a second set of bristle tufts set into
the base plate extending along one side of the first set of bristle
tufts and angled outwardly therefrom at an angle within the range
of 5.degree.-15.degree.; and a third set of bristle tufts set into
the base plate extending along the opposing side of the first set
of bristle tufts and angled outwardly therefrom within the range of
5.degree.-15.degree., wherein the bristle tufts in the second and
third sets are set into the base plate a horizontal distance "r" in
the range of 1.2 mm to 4 mm from the center of rotation of the
brushhead.
2. The bristle configuration of claim 1, wherein the angle of the
bristles is approximately 10.degree..
3. The bristle configuration of claim 1, wherein the length of the
bristles in the first, second and third sets of bristles is such
that the tips of the bristles from a shallow arc centered on the
axis of rotation of the brushhead base plate.
4. A brushhead for a power toothbrush in which the brushhead is
driven in a side-to-side motion, comprising: a brushhead base
plate; a plurality of lateral rows of bristle tufts, each row
comprising: a first set of bristle tufts set into the base plate
substantially vertically, arranged in the longitudinal direction of
the base plate; a second set of bristle tufts set into the base
plate extending along one side of the first set of bristle tufts
and angled outwardly therefrom; and a third set of bristle tufts
set into the base plate extending along the opposing side of the
first set of bristle tufts and angled outwardly therefrom, wherein
there is a difference in length between the bristles in adjacent
tufts of bristle in the second and third sets of bristles in the
range of 0-1.25 mm and an angular difference between the action
angle and the bristle angle of the bristle tufts in the range of
0.degree.-21.degree..
5. The brushhead of claim 4, wherein the second and third sets of
bristle tufts are arranged on the bristle plate to be offset from
the center of rotation of the bristle plate.
6. The brushhead of claim 4, wherein the amplitude of movement of
the brushhead and the speed of the brushhead can be increased by
approximately 15-30 percent without increasing discomfort to the
users.
7. The brushhead of claim 4, wherein the angular difference is
within the range of 17.degree.-21.degree..
Description
[0001] This invention relates generally to brushheads for
toothbrushes, and more specifically concerns a brushhead with a
particular bristle arrangement on the brushhead.
[0002] Certain power toothbrushes, for example, sonic (acoustic)
energy toothbrushes such as shown and described in U.S. Pat. No.
5,378,153, which is owned by the assignee of the present invention,
provide a selected amount of acoustic energy to the teeth for
cleaning, by bristle-fluid interaction, in addition to scrubbing
action by the tips of the bristles being in direct physical contact
with the teeth. The acoustic energy provided to the teeth is
particularly effective in cleaning hard-to-reach places, such as
between the teeth and into the gingival areas. Acoustic energy thus
is desirable for overall effective teeth cleaning. Increasing the
applied acoustic energy, which increases the cleaning effect, can
be accomplished in one way by increasing the speed of the bristles.
However, there are significant limitations on increasing bristle
speed, because as bristle speed increases, so does discomfort to
the user and also abrasion of the teeth and/or the gums.
[0003] It is thus desirable to increase the bristle speed, in order
to increase acoustic energy cleaning, without correspondingly
increasing the discomfort to the user or abrasion to the teeth
and/or gums. This is accomplished by the particular bristle
arrangements shown and described herein.
[0004] Accordingly, the present invention comprises a brushhead for
a power toothbrush in which the brushhead is driven in a
side-to-side motion, comprising: a brushhead base plate; a
plurality of lateral rows of bristle tufts, each row comprising: a
first set of bristle tufts set into the base plate substantially
vertically; a second set of bristle tufts set into the base plate
extending along one side of the first set of bristle tufts and
angled outwardly therefrom at an angle within the range of
5.degree.-15.degree.; and a third set of bristle tufts set into the
base plate extending along the opposing side of the first set of
bristle tufts and angled outwardly therefrom within the range of
5.degree.-15.degree., wherein the bristle tufts in the second and
third sets are set into the base plate a horizontal distance "r" in
the range of 1.2 mm to 4 mm from the center of rotation of the
brushhead.
[0005] FIGS. 1A and 1B show a bristle arrangement where the center
line of the bristles is located a distance from the center of
motion of a rotating brushhead.
[0006] FIGS. 2A and 2B show an angled bristle arrangement where the
center line of the bristles passes through the center of rotation
of a rotating brushhead.
[0007] FIG. 3 shows a brushhead arrangement of the present
invention.
[0008] FIG. 4 shows a power toothbrush which could use the bristle
arrangement of FIG. 3.
[0009] FIG. 5 is a graph of bristle effectiveness involving bristle
mounting angle and the bristle distance from the center of the
brushhead.
[0010] FIG. 6 is a cross-section showing a bristle plate and a
bristle mounted in a particular angular orientation on the bristle
plate which incorporates a future of the present invention.
[0011] FIG. 7 is a cross-section showing a bristle plate with
another bristle arrangement.
[0012] FIG. 8 is a graph of bristle effectiveness involving change
in the bristle "action" length against the difference between the
"action" angle and the "bristle" angle.
[0013] FIG. 4 shows a power toothbrush which could use the bristle
arrangement of the present invention. The power toothbrush 10
includes a handle portion 12 and a head portion 14. Head portion 14
includes an extending brushhead arm 16, at the remote end of which
brushhead 18 is mounted. Arm 16, in operation, is rotated through
an arc of selected amplitude by a drive system located in the
handle. The drive system is not shown in detail. The drive system
may be any one of various arrangements, including a motor with a
rotating armature or an electromagnetic driver, such as shown in
the '153 patent. It should be understood that the present invention
is not limited to a particular drive system.
[0014] FIGS. 1A and 1B show a conventional bristle arrangement,
including a bristle plate 23, where the bristles (one bristle tuft
25 is shown for illustration) are located a distance "r" from the
center of rotation of the brushhead. Each bristle tuft includes a
number of individual bristles, typically between 10 and 50. In this
arrangement, a large force is generated by the tops of the bristles
in the bristle tufts on the teeth surface 26, due to compression of
the bristle during operation.
[0015] FIGS. 2A and 2B show another conventional bristle
arrangement, including a bristle plate 27, in which the bristles
(one bristle tuft 28 is shown) are angled, extending from in effect
the center of rotation 29 of the brushhead (bristle plate). In this
arrangement, there is no compressive loading by the bristle tips on
the teeth and hence little, if any, scrubbing action on the
teeth.
[0016] FIG. 3 shows the brushhead configuration of the present
invention. The brushhead 30 includes a bristle plate 32, which can
have various configurations, with a plurality of bristle tufts
shown mounted therein. In the embodiment shown, the plurality of
bristles includes three sets of bristle tufts (38, 40, and 42), at
one longitudinal location along the bristle plate. The first set
shows two bristle tufts, off the center line of the bristle plate,
while the second and third sets include only one tuft. The term
"set" herein includes one tuft. There could, however, be more than
one tuft in each set. In one brushhead embodiment, comprising a
plurality of lateral rows of bristle tufts, each row includes one
bristle tuft in the second and third sets of bristle tufts and
between zero and two bristle tufts in the first set of bristle
tufts. The rows with zero tufts in the first set will be in the
first rows and the last one/two rows. Other brush configurations
are of course possible.
[0017] The first set of bristle tufts 40 (two tufts are shown)
extend vertically upwards from bristle plate 32, approximately 1.2
cm. high. Each bristle tuft contains approximately 10-50 bristles.
Typically, the bristles will be made of nylon, and will be in the
range of 0.004-0.009 inches in diameter.
[0018] The second and third sets of bristle tufts (38 and 42, with
one tuft shown in each set) are located on opposite sides of the
first, mid-position bristle tuft set 40. The second and third sets
of bristle tufts are substantially identical to each other and are
similar to the bristles in the first set, being also made of nylon
and having approximately the same diameter as the first set. The
second and third sets of bristle tufts, however, are oriented at an
angle to the vertical, as shown in FIG. 3. In the embodiment shown,
this angle is in the range of 5.degree.-15.degree., preferably
10.degree.. The angle from the vertical for the bristle tuft sets
is the same for both the second and third sets of bristle tufts,
except in opposing directions.
[0019] The length of the bristles in the second and third sets of
bristles is such that when the brushhead is at rest, as shown in
FIG. 3, the tips of all the bristles (the bristles in first, second
and third sets of bristle tufts) form a shallow arc, with the
center of the arc being the center of motion of the bristle
tufts.
[0020] FIG. 5 shows a graph of bristle angle versus radius of
movement action, providing a region of effective action of the
toothbrush. The range of effectiveness for "r" (distance from
center of brushhead) is 1.2 mm to 4 mm, while the range of
effectiveness for bristle angle is between 0.degree.-8.degree. for
an r of 1.2 mm and between 5.degree.-50.degree. for an r of 4 mm.
Within the rectangle 60, defined by the above limits, brushing
experience is good.
[0021] FIG. 6 shows another bristle arrangement, including a
bristle plate 61 in which a bristle tuft 62 is mounted at point 64,
angled from the center of rotation 66 of the brushhead, and having
both what is referred to herein as an "action angle" (the angle
"BAC"), where the line "CE" is perpendicular to the longitudinal
axis of the bristle plate and extends through the bristle plate
center of rotation A, and a "bristle mounting angle" (the angle
"BEC"), where the line BE extends through the mounting point D of
the bristle tuft on the bristle plate.
[0022] The angular difference between the action angle and the
bristle angle (the "delta" angle ABE) has a direct and significant
influence on the performance of the toothbrush. In a normal bristle
configuration there is the potential for the bristles to bend
and/or be dragged across a tooth surface, as opposed to a "dig"
and/or "buckle" action against the surface. The most efficiently
performing bristle arrangement will have a hypothetical delta angle
of 0.degree.; it has been established in this present invention
that the upper limit of an efficiently performing bristle
arrangement is with a delta angle of 21.degree.. A practical and
preferred range for the delta angle is 17-21.degree..
[0023] FIG. 7 shows another bristle arrangement, including a
bristle plate 70, in which two adjacent bristle tufts 72, 74 are
angled from the center of rotation A of the brushhead (bristle
plate 70). FIG. 7 illustrates "action lengths" of bristle tufts 72
and 74, action lengths being the distance between the respective
tips of the bristle tufts 72 and 74 and the axis of rotation
[0024] A of the bristle plate.
[0025] Considering adjacent tufts of bristles (as viewed in the
plane perpendicular to the axis of rotation), such as bristle tufts
72 and 74, as the bristles move against the teeth, differences in
action length between two adjacent tufts have to be accommodated as
the longer tuft comes into position by flexing of tufts or moving
of the brush by the user (or in reaction to the impact of the
longer action length tuft in a space previously accommodating the
smaller one). The flexing or impact will be detrimental to the
experience of the user as well as brush performance (energy is
wasted). The most efficiently performing brush will have a zero
change in action length from adjacent tuft to adjacent tuft. It has
been established by the inventors herein that the most efficiently
performing toothbrush will have an upper limit of 1.25 mm in the
change of action length from bristle tuft to adjacent bristle
tuft.
[0026] FIG. 8 is a graph of change in action length between
adjacent tufts versus the angular difference (delta angle) between
the action angle and the bristle angle discussed above relative to
the arrangement of FIG. 6. As noted above, the range of
effectiveness for the change in action length is 0 mm to 1.25 mm,
while the range of effectiveness of the delta angle is 0.degree. to
21.degree.. These two ranges produce a rectangular region 80, where
brushing experience is good.
[0027] The angled bristle arrangement has an important cleansing
effect during operation of the toothbrush. It provides users an
enhanced brushing experience. The amplitude of the brush motion, as
well as the frequency of the motion, can be increased, to increase
the speed of the bristles, which improves cleaning, without causing
discomfort to the user or abrasion to the user's mouth/gum tissues.
The end loading of the bristles which causes the discomfort is a
function of the impact angle created by the angled bristles. When
the bristles are angled away from the direction of motion, but
offset from the center of rotation of the brushhead, the end
loading of the bristle tips is decreased to some extent, resulting
in weaker forces to the teeth. This weaker loading provides less
mechanical cleaning action on the teeth, but does decrease the
acoustic energy transfer to the teeth.
[0028] The acoustic energy transfer can now be increased by
increasing the speed and/or amplitude of the bristle motion,
without discomfort, which is caused by the mechanical scrubbing
action. As an example, the amplitude of the brush movement can be
increased from approximately 13.degree. to 16.degree., an increase
in the range of 15-30 percent. At the same time; or independently,
the speed of the brushhead can be increased, by approximately 15-30
percent. Both the amplitude and speed of the brushhead can be
increased if desired.
[0029] Hence, a new bristle arrangement has been disclosed, using a
radially angled bristle arrangement, which permits an increase of
velocity or amplitude of the rotational brushhead (with bristles)
motion, which in turn results in enhanced cleaning, without
discomfort and/or abrasion to the tissues.
[0030] Although a preferred embodiment of the invention has been
disclosed for purpose of illustration, it should be understood that
various changes, modifications and substitutions can be
incorporated in the embodiment without departing from the spirit of
the invention which is defined by the claims which follow:
* * * * *