Note: Descriptions are shown in the official language in which they were submitted.
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1 This invention relates to toothbrushes. ~ore
particularly this invention concerns a toothbrush having two-brush; ~
heads.
Two-brush head toothbrushes are already well ]cnown and
normally include a handle which is provided with two bristle-sides
~ which are arranged at a front end of the handle. The two bristle
`- sides are arranged opposite to each other, thereby defininy a V-
shape form so that bristle-bundles provided at the bristle sides
form an intermediate cleft.
It has been recognized that these toothbrushes are
not satisfactory with respect to convenience, comfort and efficiency
of cleansing of the inner or outer side of the teeth as well as the
cleansing of the crowns togather with tooth cavities and gingival
margins. During the course of brushing the teeth it is very im-
portant to properly brush the tooth-cavities and spaces between the
teeth, which are sometimes very narrow and almost inaccessible.
Under these circumstances a toothbrush must have a possibility to
be reciprocated along the teeth as well as moved up and down, to
obtain the most desirable brushing effect and to remove tartar and
food remnants from the spaces between the teeth, as well as from
necks and cavities of the teeth-.
It is a general object of this invention to overcome
the above-described disadvantages.
More particularly, it is an object of the invention
,~ to provide an improved toothbrush for convenient, comfortable and
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efficient cleansing of all surfaces of the teeth, together with
tooth cavities and gingival margins.
A further object of the present invention is to provide
a toothbrush which enables a user to reach all the teeth without
discomfort and which permits the reciprocating movement of such a
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` 1 toothbrush along the teeth as well as up and down, in order to
get efficient brushing of all surfaces of the teeth.
Pursuant to these objects, and others which will
become apparent hereinafter, one Eeature of the present invention
resides in a toothbrush which comprises an elongated handle which
has a longitudinal axis, a front end and a rear end, a U-shaped
~ head which is coaxial with the front end of the handle. The head
`~- has two opposite bristle-carrying portions located to opposite
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sides of the axis and each of the bristles-carrying portions has a
` 10 front-edge inclined at an acute angle to the axis. The bristles-
carrying portions are provided with a plurality of bristle tufts
which are spaced from each other and project inwardly from the
bristle-carrying portions. The tufts are arranged in a first plu-
rality of rows substantially parallel to the front edge and in a
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~ second plurality of rows parallel to the axis. The first and second
:`- plurality of rows intersects each other at four corner points and
the axes of the tufts of bristIes at the four corner points which
extend with inclination toward each other. The ends of the bristles
in the second plurality of rows on the opposite bristle-carrying
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portions are arranged so as to define an acute gap therebetween.
In accordance with another feature of the present invention the
~- handle has rearwardly of the head a portion curved transversely to
the axis, so that the end of the handle and the middle of the head
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~`- are lying on one and the same axis.
- Another advantageous feature of the present invention
,J','', resides in providing the front end of the head of the handle with
a slope rearwardly towards the rear end of the handle. This feature
renders it possible to reach the rear molars without difficulty and
~ ` discomfort.
;~ 30 According to another advantageous feature of the
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1 present invention a toothbrush is provided with coupling means
at the rear end of the handle for coupling means therefor for
oscillating the toothbrush about the axis. In other words, the
head receives an oscillating movement from the means connected to
-- the rear end of the handle, which means can be mechanical or
electrical one. This movement is transmitted to the brush-elements
of the head. Besides this an additional movement of the brush
relative to its longitudinal axis is possible, as well as up and
down, that is an oscillating movement of the toothbrush along the
rows of the teeth, whereby obtaining an efficient but still comfor-
`table cleansing of all surfaces of the teeth together with tooth
~- cavities and gingival margins.
FIG. 1 is a perspective view of a toothbrush in
accordance with the pxesent invention;
FIG. 2 is a longitudinal view of the toothbrush
viewed from the back;
~ FIG. 3 is a longitudinal sectional view of the tooth-
- brush;
FIG. 4 is a front view of a bristle-carrying portion;
20 FIG. 5 is a view of bristles, arranged for cleaning
the teeth;
FIG. 6 is a view of bristles, arranged advantageously
for cleansing and massaging the gingival;
FIGS. 7a through FIG. 7f, FIG. 14, FIG. 15 show
usage of the toothbrush;
FIG. 8, FIG. 9, FIG. 10, FIG. 11, FIG. 12, FIG. 13
show steps of a method of making the toothbrush in accordance with
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pthe present invention. ;
`Referring now to the drawings and first to FIG. 2
` 30 thereof, it may be seen that the reference numeral 1 is used to
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1 designate a handle which has a rear end and a front end~ The
.. front end of the handle is provided with a U-shaped head which has
: two opposite arms 2 and 3. The a:rms are provided to carry bristle
.~ bundles 7, so that the bundles of different arms de~ine a gap 5
: (see FIG. 1) therebetween.
In contrast, to the prior art toothbrushes, which have
a handle which is bent only upwarclly at its rear portion, the handle
i.` 1 of the present invention is bent in such a portion 8 between the
s. end 10 of the handle 1 and the U-shaped head carrying the bristle-
.. 10 bundles, that that end 10 of the head (2, 3) are coaxial, that is
they have one and the same axis X-Y (see FIG. 3) of symmetry.
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.~ . The front ends of both arms 2 and 3 are provided with
.. ~ a slope 11 inclined rearwardly relative to the longitudinal axis 9
. o the handle to thereby make it possible to reach the area of the
~ rear molars. Transition zones 30 and a different thickness 31 of
~: the handle along its length are provided to insure convenience,
comfort and efficiency of the toothbrush in its usage.
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The rear end of the handle 1 is provided with coupling
. means for connecting to a suitable driving arrangement for subjecting .
..`i 20 the toothbrush to oscillating movement around the axis 9.
:: - The coupling means can be, for example, accomplished
,s....... as a socket-switch connection 10, or handgrip 22. The driving ar- ..
rangement can be any conventional device, either mechanical or
~l electrical. ~`
The bristle bundles 7 project inwardly from kristle-
.1 carrying arms 2 and 3 and they are spaced .from each other so that
.. they bound a first plurality of rows parallel to the front edge of
the head and a second plurality of rows parallel to the longitudinal
axis 9 (see FIG. 1). The ~irst and second plurality of rows inter-
sect each other at four corner points and are inclined toward each
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1 other, thereby defining -- if viewed transversely as show~ in
FIG. 4 -- a rhomboid form. Such an arrangement of tufts h~s the
advantage, that it facilitates brushing of the spaces between teeth,
which sometimes are very narrow. The ends of bristles in the second
plurality of rows on the opposite bristle-carrying arms 2 and 3 are
arranged so as to define an acute gap 5 therebetween.
The ends of the bristles are drawn back vertically
and/or transversely to the longitudinal axis 9 (see FIGS. 10 and 11)
to define a first imaginary edge 40 positive relative to the axis
10 9 as well as a second imaginary edge 41 which is negative relative
to the axis 9. T,~hen the bristles 7 are folded on the arms 2 and 3
- they define different bristle positions (see FIGS. 6 and 13) rela-
~ tive to the axis 9. The position sho~n on FIGS. 5 and 12 is advan-
-~ tageous for cleansing all surfaces of the teeth, whereas the posi-
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tion shown in FIGS. 6 and 13 is partlcularly advantageous for
cleansing and massaging of the gingival. The bristles which are
arranged in interim bristle rows with a negative inclination rela-
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tive to the axis 9, are operative when the gingival is being
~-; brushed. This row performs a care effect for the gingival, where-
as the upper rows perform cleansing and massaging effects.
Important cleansing in the spaces between the teeth
and in the gingival spaces as well as tooth cavities will be ob-
tained by penetrating of the bristles into said cavities and spaced ;
~ when applying to the toothbrush an additional oscillation about the
;~; axis 9.
- During operation, for example during brushing of the
incisors 14 (see FIG. 7a), the bLush executes an an~ular mov~ment 12
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back and ~orth along the axis 9. Meanwhile the bristles 7 are
oscillated in order to pass through into tooth-cavities, tooth-
spaces and fissures 17 from the front and back side of the teeth,
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1 and also to massacJe the gingival 20. As a result of these motions
the brush removes all film and food particles and stimulates
circulation. The oscillating brush can be just pushed along the
teeth and the brush will be automatically guided by the curve of
the row of teeth. An excellent cleansing as well as massage of the
- gingival will be accomplished mechanically as shown on FIGS. 7a
through 7f, at 14 and 15, by applying light pressure to the handle.
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A method of making a toothbrush according to the
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present invention is as follows: (see FIGS. 8, 9, 10, 11, 12, 13).
A workpiece of synthetic plastic material is shaped
for example injection molded, in order to obtain a flat-shaped
' handle provided with a fork-shaped head. The portion of the handle
from the middle of the latter up to the front end thereof is then
offset relative to the longitudinal axis of the handle, so as to
foxm a curve 39.
The partly finished curve portion 8 is then sukjected
to the final shaping, for example, by thermoplastic treatment 37,
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; so as to fold and shape towards each other (38) the two arms 2 and
3 of the fork-shaped head. The head as folded has a common axis X-Y
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~- 20 (a). The folding can be accomplished in a forming die. The portion
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,~ 36 which has the form of a blunt point, renders it possible to per-
'~ form deformation of the fork-shaped head without creating any
creases in the material of the same.
The installing of the bristle bunches is effected with
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a flat axis either normally or at any different angles to the head
and the bristles are then trimmed at any desired inclination relative
to the axis of the handle. These steps are carried out before
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