Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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Toothbrush Having Controlled
Head Movement
Field of the Invention
The present invention relates to toothbrushes and in particular to
toothbrushes whose head position can be manipulated by applying
pressure to specific segments of the handle.
Background of the Invention
Conventional toothbrushes comprise uniform tufts of bristles each
having a first end which is held captive in and fixed to a brush head,
and a second end which is free and which is used for brushing. The
free ends of the various tufts present a surface envelope which is
capable of slight deformation by the bristles bending when they come in
contact with a surface to be brushed, but which is incapable of
adequately matching a surface having a complex shape. Such a
complex surface is present in the mouth, wherein the teeth generally lie
in a "C" shaped curve within the upper and lower jaw, each row of teeth
consequently having a convex outer curve and a concave inner curve.
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In toothbrushing the desire of users to cause the bristles to conform
to the teeth is expressed by the forceful application of the brush to
adequately deform the bristles to the arcuate contours of the dentiture.
Such forceful application of the brush against the teeth merely leads to
excessive wear of the tooth surfaces and gums, without adequate
conformation of the brush to the teeth to provide the desired cleaning.
Toothbrushes having a flexibly neck located between the brush head,
containing the bristles, and the handle have been disclosed in the prior
art to provide conformation of the brush to the contours of the
dentiture. Examples of such flexibly neck toothbrushes include the
toothbrushes disclosed in U.S. Patents 759,490 and 4,520,526. U.S.
759,490 creates neck flexibility by interposing a flexibly resilient
material between a rigid brush head and handle, which flexibly resilient
material may be reinforced with a second such type of material. U.S.
4,520,526 creates neck flexibility by the alternatives of either removing
part of the material from the top and bottom of the neck portion of the
brush, or having an oval shaped hollow in the neck extending from one
side to the other. Such flexibly resilient toothbrush necks permit the
bristle head to yield relative to the handle when the user, whereby the
danger of injury to the teeth and gums is reduced, applies excessive
force. However, such flexure means do not allow the user the ability to
control the contour of the brush head to the particular arch of the oral
surface being brushed, to avoid the need to apply excessive force in the
first instance.
U.S. Patent 4,333,199 discloses a toothbrush whose head is pivotally
mounted on a coiled spring above a recessed handle, such that the
head is adapted to rotate and tilt as it is applied to the teeth. While
such flexing action will allow the brush head to generally follow the
arch of the oral surface being brushed, it provides no direct control by
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the user of the moving, tilting, and rotating action of the toothbrush
head.
PCT International Application WO 89/ 10076, discloses a toothbrush
having the capability of varying the angle between the brush head and
the handle in order to position the brush head in parallel with a
arcuate section of the dentiture. WO 89/ 10076 discloses a toothbrush
having a handle pivotally connected to the head, wherein the handle is
formed of a pair of spaced apart, rigid, upper and lower sides, which
sides are pivotally linked together to be movable lengthwise relative to
each other. Alternatively, the spaced apart, rigid, upper and lower
sides may be connected by means of an elastic spacer layer, which will
also allow them to be movable lengthwise relative to each other. Use of
a such a pivotally connected handle and head, controlled by the
lengthwise movement of the rigid sides of the toothbrush, to accurately
control the position of the toothbrush head is difficult at best. Such
lack of precise control is due to the fact that pivoting linkages, which
lack rigidity or resistance will tend to move the head excessively; while,
the alternative use of an elastic layer will limit the movement of the
head proportional to the degree of elasticity therein.
There is a need in the art for a toothbrush, wherein the user, to
position the head in conformity with the arcuate configuration of the
dentiture can more precisely control the position of the toothbrush
head.
Summary of the Invention
The present invention encompasses a toothbrush comprised of an
elongated handle formed of a relatively rigid, generally S-curved
longitudinal backbone section, extending at one end into a relatively
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straight neck with a flattened head portion containing a plurality of bristle
tufts
extending therefrom; wherein, the generally S-curved longitudinal backbone is
opposed by a corresponding generally S-curved section of a relatively
resiliently
flexible elastomeric material, such that the opposed S-curves form a generally
elongated figure 8 having extending transversely therethrough an upper and a
lower aperture. During brushing of the teeth, the user can manipulate, i.e.
apply pressure to, the upper relatively rigid S-curve backbone or to the
opposed
resiliently flexible elastomeric section, while simultaneously compressing an
opposite rigid and/or elastomeric section, to position the bristle bearing
toothbrush face in a controlled manner to conform to the arcuate configuration
of the dentiture.
The present invention also encompasses a toothbrush comprised of an
elongated handle formed of a relatively rigid backbone section which defines a
first side of an aperture and a resiliently flexible elastomeric section which
defines a second side of the aperture. The relatively rigid backbone section
extends at one end into a base and extends at the other end into a neck
portion
provided with a flattened head portion with an upper face having extended
therefrom a plurality of bristle tufts.
Brief Description of the Drawings
Fig. 1 is a longitudinal perspective view, showing the a first embodiment of
the toothbrush of the present invention with an arbitrarily curved bristle
pattern, a sufficiently c 1 ear elastomer about the handle and extending to
the
base of the neck, such that the S-curved relatively rigid backbone is visible,
and a broadened base.
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Fig. lA is a perspective view of the toothbrush of Fig. 1, wherein a vertical
plane and horizontal plane have been added; the vertical plane being
perpendicular to the face of the toothbrush and through the longitudinal axis;
A-A.
Fig. 2 is a cross-section side plan view, showing a second embodiment of the
toothbrush of the present invention, with a typical flat bristle pattern and a
broadened base.
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Fig. 3 is a cross-section side plan view, showing a third embodiment
of the toothbrush of the present invention, with a typical flat bristle
pattern and a broadened base.
Fig. 4.is a cross-section side plan view, showing a fourth embodiment
of the toothbrush of the present invention, with a typical flat bristle
pattern and a broadened base.
Fig. 5 is a perspective view of the toothbrush of Fig. 1, shown from a
broadened base and extending to the head thereof, with an arbitrary
bristle pattern.
Fig. 6 is a cross-section side plan view, showing a fifth embodiment
of the toothbrush of the present invention, with a typical flat bristle
pattern and a broadened base.
Fig. 7 is a cross-section side plan view, showing a sixth embodiment
of the toothbrush of the present invention, with a typical flat bristle
pattern and a broadened base.
Fig. 8 is a cross-section side plan view, showing a seventh
embodiment of the toothbrush of the present invention, with a typical
flat bristle pattern and a broadened base.
Fig. 9 is a cross-section side plan view, showing an eighth
embodiment of the toothbrush of the present invention, with a typical
flat bristle pattern and a broadened base.
Fig. 10 is a cross-section side plan view, showing a ninth
embodiment of the toothbrush of the present invention, with a typical
flat bristle pattern and a typical narrowed toothbrush base.
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Detailed Description of the Invention
Referring now to the drawings, wherein like reference numerals refer
to the same or similar elements among the several figures, and in
particular referring to Fig l; wherein there is shown a toothbrush, 12.
Fig. 1 is a perspective view of a toothbrush of the present invention
about a longitudinal axis A-A, with an upper side, 13, and an opposed
lower side, 15, wherein the toothbrush has a head, 14, integral to and
extending from a neck, 16, which neck is integral to and extending
from a handle, 18, which handle is integral to and extending from a
base, 24. The head, 14, having a face, 20, on the upper side, 13,
thereof; from which face extend rows of bristle tufts, 22, transverse to
the longitudinal axis A-A.
In accordance with the present invention, the head, 14, can flex
relative to the handle, 18, in the vertical plane, identified as V in Fig.
lA; but, is substantially rigid relative to the handle in the horizontal
plane, identified as H in Fig. 1. Such flexibility is due to the fact that
the handle, 18, is multi-sectional, that is formed in sections of at least
two materials having significantly different modulus of elasticity; one
section being formed of a relatively rigid plastic and the other section
being formed of a resiliently flexible elastomer. The relatively rigid
plastic section comprises a generally S-curved longitudinal backbone,
26, extending from the neck of the toothbrush to the broadened base,
24, thereof. The resiliently flexible elastomeric section is also in the
general shape of an S-curve, 28, and in opposed relation to the
generally S-curved longitudinal backbone, 26, such that the opening of
the generally S-curved rigid longitudinal backbone are closed by the
generally S-curves of the resilient flexibly elastomeric section, 28.
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Together, the S-curved rigid longitudinal backbone, 26 and opposed
generally S-curved resilient flexibly elastomeric section, 28, form a
generally elongated figure 8-shape. The interlocking S-curves that form
the generally figure 8-shape handle define two apertures, an upper
aperture, 30, more proximate to the neck, 16, and a lower aperture, 32,
more proximate to the base, 24; both apertures are preferably
approximately equal in cross-sectional area.
The apertures, 30 and 32, are of sufficient cross-sectional area such
that when the user applies a greater force to the relatively rigid
backbone section, 26, about the upper aperture, 30, than to the
opposed relative resiliently flexible section, 28, about the upper
aperture, 30, or to the opposed relatively rigid backbone section about
the lower aperture, 32, the connected bristle bearing head, 14, deflects
to a position in the direction of the upper side, 13, of the toothbrush.
The forces involved in this manipulation by the user are illustrated in
Fig. 1 by the opposed arrows at an acute angle to the longitudinal axis
A-A. Correspondingly, the user can apply a greater force, at an
appropriate angle, to the relatively resiliently flexible section, 28, about
the upper aperture, 30, than to the corresponding relatively rigid
backbone, 26, about the upper aperture, 30, such that the bristle
bearing head, 14, will deflect to a position in the opposite direction, i.e.
away from the upper side, 13, of the toothbrush.
The interlocking S-curve sections that form the handle are shown in
Fig. 1 as being substantially equally spaced about the longitudinal axis
A-A; however, in alternate embodiments of the present invention, the
interlocking S-curves can be more forward of the longitudinal axis A-A,
Fig. 2, or more behind the longitudinal axis A-A, Fig. 3. Further, while
in Fig. 1 the apertures 30 and 32 are generally oval with a relatively
narrow transverse axis in relationship to a longer longitudinal axis,
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which longer longitudinal axis may be aligned with or at an acute angle
to the longitudinal axis A-A of the toothbrush; these apertures can be
rounder, with much greater transverse axial length in relationship to
their longitudinal axial length, such as shown in Fig. 2. Alternatively,
the apertures, 30 and 32, can be crescent shaped as illustrated in Fig.
8.
In accordance with the present invention the head, 14, the neck, 16,
the S-curved backbone, 26, and the base, 24, are molded as an integral
work-piece of relatively rigid polypropylene or other plastic with a
similarly relatively rigid structure, such as a polyamide, i.e. nylon; or a
polyester or a co-polyester, such as polyethylene terephthalate (PET), or
a polycyclohexylene dimethylene terephthalate that is acid modified
(PCTA); or a cellulosic plastic; or styrene acrylonitrile (SAN) or
acrylonitrile butadiene styrene (ABS). The polypropylene or other rigid
plastic is preferably of a Shore A Hardness ranging from 40 to 110,
more preferably 60 to 110 and most preferably from 80 to 100.
Suitable polypropylene is available from Huntsman Corporation,
Longview, Texas, 75603 under the trade-designation Huntsman
Polypropylene P4G3Z-039.
The relatively resiliently flexible elastomeric S-curve section, 28, may
be molded of a variety of elastomeric materials, most especially
thermoplastic elastomers (TPE). Acceptable TPE materials for the
relatively resiliently flexible S-curved elastomeric section, 28, including
styrene-ethylene/butylene-styrene (SEBS) Type styrene block
copolymers, such as styrene-butadiene-styrene, styrene-
isoprenestyrene, and related copolymers, as well as, thermoplastic
polyurethane (TPU) or a thermoplastic vulcanate (TP~ which consists
of a mixture of polypropylene and EPDM (ethylene propylene dime
monomers) which is available as Santoprene (brand), described in U.S.
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Patent 5,393,796; or Vyram (brand), another TPV consisting of a
mixture of polypropylene and natural rubber, both Santoprene and
Vyram being elastomers marketed by Advanced Elastomer Systems LP,
Akron, Ohio 44311. Another, and preferred TPE is Dynaflex 66713
(brand), .marketed by GLS Corp., Cary, Illinois 60013. These and other
suitable elastomers have, typically, a Shore A hardness of from about 1
to 94, with about 15 to 60 being a preferred, and about 15 to 40 being
most preferred.
The resiliently flexible elastomeric material can be overmolded about
the handle, 18, as shown in Fig. 4, a cross-section view, as the
elastomic overmolded region. The resiliently flexible elastomic S-curved
section is shown in Fig. 4 as areas, 38 and 40, which are separated in
the cross-section shown by the generally elongated S-curved relatively
rigid backbone, 26. The degree of flexibility of both the relatively rigid
backbone section, 26, and of the resiliently flexible elastomeric S-curve
section, areas 38 and 40, can be further controlled by varying the
thickness thereof, i.e. to provide more or less flexibility.
If a substantially clear appearance is desired for the relatively rigid
components of the toothbrush, i.e. the toothbrush head, 14, the neck,
16, the relatively rigid generally S-curved backbone section, 26, and the
base, 24, can be of polyester, such as polyethylene terephthalate or a
copolyester, such as PCTA polyester or SAN, or a cellulosic plastic,
such as cellulose acetate propionate (CAP). If a substantially clear
appearance is desired for the resiliently flexible elastomeric components
of the toothbrush, i.e. the resiliently flexible S-curved elastomeric
section, 28, certain TPE, or TPUS, or ethylene vinyl acetate (EVA)
materials can be used. A preferred substantially clear TPE is available
from Teknor Apex Company, Pawtucket, Rhode Island 02861, sold
under the trade-designation 96-E0807A-03NT WAT CLR.
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Alternative embodiments of the present invention can contain within the
upper and lower segments of the generally figure 8 shaped handle, 18, not only
the two apertures previously discussed; but, also within each segment a single
aperture or a grouping of a plurality of apertures, i.e. three, four, five or
six
apertures. In the case of either a single or such a grouping of apertures in
the
handle, 18, the relatively rigid backbone forms a first side of each aperture
or
grouping of apertures and a relatively resilient flexible elastomer forms the
second side of each aperture or grouping of apertures. The apertures) may be
generally crescent, generally oval or generally round, with their longitudinal
axis generally aligned with or at an acute angle to the longitudinal axis of
the
toothbrush A-A. Such multiple apertures may all be located substantively
about the longitudinal axis of the toothbrush, or on either side thereof.
Illustrative illustrations of such alternative embodiments are shown in Figs.
6,7
and 9.
Likewise, further alternative embodiments of the invention can have a
handle having a longitudinal axis, an upper side and a lower side and
containing a relatively rigid backbone section which defines a first side of
an
aperture and a resiliently flexible elastomeric section which defines a second
side of. the aperture. The aperture itself may be oval, round or generally
crescent shaped. The longitudinal axis of the aperture may be generally
parallel to the longitudinal axis of the handle. Alternatively, where the
aperture
is oval in shape, the longitudinal axis of the aperture may be aligned at an
acute angle with the longitudinal axis of the toothbrush. The relatively rigid
backbone section and the relatively resiliently flexible elastomeric section
are
molded in much the same way and have much the same material properties as
the S-curved backbone 26 and relatively resiliently flexible elastomeric S-
curve
section 28, respectively, described previously.
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As the embodiment of the present invention containing a broadened base
taken with the overall dual component construction add significantly to the
weight of a typical toothbrush, the base can be hollow to minimize the
additional weight. As shown in Fig. 5, such a hollow base can be formed of an
inner injection molded relatively rigid polypropylene shell, 34, surrounded by
the resilient flexibly elastomeric material, 36 which comprises the
resiliently
flexible elastomeric material. Alternatively, as shown in Fig. 10, the present
invention may contain a typical narrowed toothbrush base, reducing
incremental weight.
Multi-section component toothbrushes of the present invention can be
molded by conventional injection molding technology, which is well known in
the art. For example, in accordance with the present
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invention, the resiliently flexible elastomeric material section may be
overmolded about the handle, 18, by a second injection step, after the
first step of injection molding the frame or skeleton, which is comprised
of the hard bristle implanting head, 14, neck, 16, relatively rigid handle
backbone section, 26, and base, 24. In this second injection step the
frame is positioned in a second mold into which the resiliently flexible
elastomeric material is inj ected about the handle, 18, thereof; more
specifically, about the relatively rigid backbone section, 26, extending
from the base, 24, to the base of the neck, 16.
Facilitation of the two step injection molding of toothbrushes of the
present invention can be by using a two component mold. Two
component molds are available from numerous suppliers, including
Machines Boucherie N.V., Izegem, Belgium; Anton Zahoransky GmbH
8y Company, Todtnau, Germany; or Braun Formenbau GmbH,
Bahlingen, Germany; which molds can be mounted in typical injection
molding machines for such implementing the two step injection
process, such machines including 300 ton, two component injection
molding machines available from Engel Vertriebsgesellschaft mbH,
Schwertberg, Austria or Netstal-Maschinen AG, Nafels, Switzerland.
The toothbrush bristles may be implanted in the toothbrush face, 20,
using either typical staple technology or using more modern non-staple
technology as disclosed in U.S. Patents 4,635,313, 4,637,660,
4,954,305, 5,045,267, 5,609,890, 5,390,984, 5,533791, and
5,823,633. Such non-staple technology involves processes wherein the
bristle tufts, 22, are fused into the toothbrush head, 14, by heating
both the bristle tufts, 22, and the toothbrush head, 14, which are then
brought together in a fusion process; or, wherein the ends of the bristle
tufts, 22, are pre-positioned in the injection mold prior to the
introduction of the toothbrush material, which toothbrush material is
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subsequently injected about the ends of the bristle tufts, 22, locking
the bristle tufts, 22, in place in the toothbrush head, 14.
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