Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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COSMETIC APPLICATOR HEAD WITH DYNAMICALLY ADJUSTABLE DUROMETER
BACKGROUND OF THE INVENTION
1. FIELD OF THE INVENTION
The present invention relates generally to cosmetic applicators, and in
particular, to a
cosmetic applicator with a dynamically adjustable flexibility. The applicator
includes
piezoelectric fibers that are capable of changing durometer in response to a
change in a
supply of electricity or a change in an electric or magnetic field.
2. DESCRIPTION OF THE PRIOR ART
Conventional cosmetic applicators such as mascara brushes have a set or fixed
degree of flexibility or stiffness at a specified temperature that is dictated
by the type of
material (e.g., plastic or elastomer), the mass, geometry and durometer of the
selected
material, and the thickness of the structural member (e.g., the diameter of a
mascara brush
bristle or tine). Durometer is a measure of the hardness of a material. The
parameters that
establish the hardness of the applicator structures (e.g., the bristles, tines
or other structures)
of a conventional cosmetic applicator are, therefore, selected and established
during the
product engineering and manufacturing process. Once manufactured, there is
little that an
end-user can do to change the established durometer or hardness of an
applicator.
The degree of hardness of a component of a cosmetic applicator may often have
an
effect on the application characteristics of a product formula, or on the
effectiveness of a
particular application process. Generally speaking, hardness is a property of
the material
used for making a component, while flexibility or stiffness is property of the
material (including
hardness) combined with the geometry of the component (i.e., the mass,
structure,
configuration and shape of the component). The hardness, or conversely, the
softness, of a
material used to make a component has a direct effect on determining the
flexibility or
stiffness of that component. The forgoing notwithstanding, the hardness of a
material used
in a component may also be referenced herein relative to stiffness of the
component, or
conversely referenced relative to the flexibility of the component. For
example, it is believed
that softer, more flexible bristles are better suited for depositing heavy
loads of mascara
product onto lashes, while stiffer, less flexible bristles are better suited
for 'doctoring' the
deposited mascara product, i.e., the stiffer less flexible bristle are better
suited for combing
through lashes to separate lashes, and remove clumps or excess mascara. See
for example
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U.S. Pat. No. 6,481,445 to Miraglia. To accommodate this phenomena, users
often deposit
mascara product with a first applicator that has softer, more flexible
bristles, and then 'doctor'
the deposited mascara product with a brush applicator or comb-type applicator
that has
stiffer, less flexible bristles or tines. This is both inconvenient and more
time consuming for
the user.
Accordingly, there is a need for a cosmetic applicator that has bristles or
tines capable
of changing durometer from soft and relatively flexible for depositing
operations, to relatively
stiff and less flexible to better doctoring and clump removal operations after
mascara is
deposited.
BRIEF SUMMARY OF THE INVENTION
The applicator of the present invention includes bristles, tines or other
applicator
components with selectively changeable durometer to allow the relative
flexibility or stiffness
to be adjusted by the user. The bristles, tines or other applicator components
are made
directly from or incorporate within their structure piezoelectric ceramic
fibers. The relative
flexibility or stiffness of the piezoelectric fibers can be adjusted by
subjecting the fibers to an
electric current, or an electric or magnetic field, to cause the fibers to
gain or lose flexibility in
proportion to the strength of the current or field, and according to the
polarity of the current or
field. Selectively variable stiffness or hardness of an applicator can offer
multiple ways to use
the same applicator, and can yield different beneficial results based on
desired application
circumstance.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional elevation view of a first embodiment of the
applicator of the
present invention together with a container for containing product;
FIG. 2 is a more detailed elevation view of the first embodiment of the
applicator shown in
FIG. 1;
FIG. 3 is a perspective view of the first embodiment of the applicator shown
in FIG. 2 during
assembly of the applicator;
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FIG. 4 is a side elevation view of the first embodiment of the applicator
shown in FIG. 2 during
assembly of the applicator;
FIG. 5 is a cross-sectional elevation view of a second embodiment of the
applicator of the
present invention together with a container for containing product;
FIG. 6 is a more detailed cross-sectional elevation view of a second
embodiment of the
applicator shown in FIG. 5;
FIG. 7 is an elevation view of the second embodiment of the applicator shown
in FIG. 5;
FIG. 8 is a cross-sectional elevation view of a third embodiment of the
applicator of the
present invention together with a container for containing product; and
FIG. 9 is an elevation view of the third embodiment of the applicator shown in
FIG. 8.
DETAILED DESCRIPTION OF THE INVENTION
A first embodiment of an applicator 1 according to the invention is shown
generally in
FIGS. 1-4. The applicator 1 may be free-standing, or as illustrated in FIG. 1,
may be part of a
product package that includes a container 50 containing a cosmetic product. As
shown in
FIG. 1, the applicator 1 includes an applicator head 2 connected to a handle 6
by a rod 4.
The handle 6 includes a hollow shell portion 7 having sufficient dimensions to
contain
additional components of the applicator, and to fit comfortably in the user's
hand or fingers.
The applicator head 2 may be in the form of, for example, a twisted wire brush
3 or a molded
applicator head 9 (see FIG. 5). The applicator head 2 may take on other forms,
such as, for
example, a wand, a spatula, a puff, a comb, or a roller (not shown). The
applicator head 2 is
adapted for applying any cosmetic product, such as, for example, mascara. The
applicator
head 2 may be a relatively flat, expanded surface, e.g., the spatula, or may
be a surface with
tines, ridges, bristles, clearances or other details suitable and adapted for
facilitating the
loading, depositing and doctoring of cosmetic product on an application target
such as, for
example, eyelashes, eyebrows, hair, skin, lips, nails, etc.
Importantly, the application head 2 includes a component or components
comprised of
at least one selectively reactive material, such as, for example a
piezoelectric material,
adapted to change at least one of shape, volume, rigidity and orientation of
the applicator
head or a portion thereof in response to a change in supplied stimulus, such
as, for example,
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electric current. The selectively reactive material may comprise a component
or a portion of a
component. For example, as illustrated in FIG. 1, the piezoelectric material
may comprise a
fiber or fibers used as a brush bristle or bristles, e.g., gripped in a
conventional twisted wire
core. Alternatively, as illustrated for example in FIG. 5, the selectively
reactive material may
be incorporated into molding compounds such that the material can be
integrally molded into
components such as tines or other relief structures of molded applicator
heads. As yet
another alternative, selectively reactive materials such as fibers can be over
molded with
elastic materials to form, for example, tines with a piezoelectric core. For
example, the
piezoelectric fibers may be molded in place within the tines, or may be
inserted in bores in the
tines. Alternatively, the piezoelectric material may comprise a surface veneer
or layer of the
tines or other structure of the applicator structure.
As an example, a first embodiment of the applicator 1 includes an applicator
head 2
that is of the twisted wire core variety and is shown at reference number 3 in
FIGS. 1-2.
Twisted wire brush 3 has a twisted wire core 12 with proximal end 14 and a
distal end 22. As
shown in Fig. 1, the proximal end 14 of the applicator head 2 is adapted to be
mounted in a
bore 16 on the rod 4 that is in turn connected to the handle 6. A lumen 42 may
be provided in
the rod 4 in axial alignment and fluid communication with the bore 16,
extending from the
bore 16 to the shell 7 to accommodate a circuit, a circuit board or conductors
between the
handle 6 and the applicator head 2. The handle 6 may include a skirt 8 with
internal threads
10 adapted to cooperatively engage corresponding external threads 51 on a neck
52 of a
cosmetic composition container 50 such that the handle 6 serves as a cap for
the container
50. When the handle 6 is secured on the neck 52 of the container 50 the
applicator head 2 is
immersed in cosmetic product stored in the container 50.
As illustrated in Figs. 3 and 4, the twisted wire core 12 is initially formed
from a U-
shaped wire 13, i.e., a wire folded back on itself to form two legs, 15 and
17. The applicator
head 3 further comprises a plurality of individual bristles 18 (illustrated
schematically in FIGS.
1 and 2) trapped between the legs 15 and 17 when the legs 15 and 17 are
twisted together to
form the core 12. The plurality of bristles 18 trapped in the twisted wire
core form a bristle
array 20. The process for making such a brush is well known and described in
more detail in
prior art patents such as U.S. Pat. Nos. 6,481,445 to Miraglia, 4,733,425 to
Hertel et al. and
4,861,169 to Schrepf, each incorporated herein by reference in its entirety.
By virtue of the
process for making the applicator head, i.e., twisting the legs 15 and 17 to
capture the bristles
18 in the core 12, the bristles 18 are fixed in the twisted wire core 12 such
that each of the
plurality of bristles 18 is in direct contact with immediately adjacent
bristles 18 of the plurality
of bristles.
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In the first embodiment, all or at least some of the plurality of bristles 18
are made
from a piezoelectric material, i.e., all or at least some of the plurality of
bristles 18 are
piezoelectric fibers 19. Electric current is supplied to the selectively
reactive material, i.e., the
piezoelectric fibers 19, via a circuit 11. The current may be an alternating
or direct current,
depending on the requirements of the particular selectively reactive material.
If alternating
current is used, it is believed that a 'pulsing' hardness or shape change can
be achieved.
The circuit 11 includes a power source 5, such as, for example, a battery 21,
a capacitor (not
shown) or a connection to an external electric grid (not shown). In general,
the power source
5 is connected to the piezoelectric material via at least two conductors, a
feed conductor 23
and a return conductor 24, in the form of wire leads or a printed circuit
board or boards. A
lumen 42 may be provided in the rod 4 in axial alignment and fluid
communication with the
bore 16, extending from the bore 16 to the shell 7 to accommodate passage of
the feed
conductor 23 and a return conductor 24 from the handle 6 to the applicator
head 2.
Preferably, to amplify and thereby increase the effectiveness of the change in
durometer, the piezoelectric material, part or component is polarized. Piezo
material, parts or
components may be polarized by applying a polarizing treatment (referred to as
"poling") to
the piezoelectric ceramic material, part or component. The purpose of poling a
piezoelectric
material, part or component is to force an alignment of all of the individual
dipole moments
(pole vectors) inherent in the individual piezoelectric crystal structures
within the material, part
or component into a similar general direction or orientation. The
piezoelectric material, part or
component is exposed to an environment where a) the temperature is close to
but below the
material's Curie point (temperature at which spontaneous polarization is lost
in piezoelectric
materials) and also b) electrodes are applied to the part, and a powerful
direct current (DC)
electric field is applied which forces the dipoles to align. Non-parallel
dipoles exposed to this
electrical field will experience a torque that causes them to be turned to a
parallel
configuration. The electric field is then removed, and the dipoles will remain
almost
completely aligned, with a minute amount of random direction in some dipoles.
The
polarizing treatment is preferred for the cosmetic applicators discussed
herein because it
amplifies the change in the durometer of the material. For example, for a
poled material with
a positive piezoelectric coefficient, also known as a piezoelectric modulus,
if a voltage of the
same polarity of the poling voltage is applied to the ceramic fibers in the
direction of the poled
voltage, the shape of tines or bristles will become dramatically softer and
more pliable. The
converse also works, for example, for a poled material with a positive
piezoelectric coefficient,
if a voltage of the opposite polarity is applied, i.e., the shape or bristles
will become
dramatically stiffer and more rigid. Most piezoelectric materials have a
positive piezoelectric
coefficent; the material PZT is an example. There are some piezoelectic
materials such as
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PVDF that have a negative piezoelectric coefficient, and will function, but in
the inverse to the
applied voltage and polarity discussed above. Also, it is possible to apply an
AC (alternating
current) voltage to the brush, which will cause the brush to stiffen and
soften at a pulsing rate
that matches the frequency of voltage that is applied.
The circuit 11 further includes a control 25 for selectively changing the
power supplied
to the piezoelectric fibers or material. The control may take the form of a
simple bi-pole
switch to selectively turn on or turn off the electric current. Alternatively,
the control may be a
potentiometer or rheostat to control resistance (this can also function as a
position
determining transducer for large changes in durometer). An indicator 26 such
as a light
emitting diode or an indicator gauge may be provided to show that the device
is working and
may provide other information such as the state of charge of the power source.
The power
source 5 (e.g., the battery 21), the control 25 (the switch or rheostat), and
the indicator 26
(the light or gauge) are preferably located on or in the handle 6, but may be
located at any
convenient place on the applicator. For example, the control may include a
knob 54 at a
closed end 53 of the handle 6 connected to a rheostat 55 that also serves to
turn the power
on and off.
In the embodiment shown in FIGS. 1-4, the circuit 11 within the twisted wire
brush
head 3 comprises a feed lead 28 connected to feed conductor 23 and a return
lead 29
connected to return conductor 24. Feed lead 28 has an insulating jacket 31
covering most of
its length. At each end of the feed lead 28 there is a clearance in the jacket
31 to allow the
transmission of electric current. At a distal end 32 of the feed lead 28, a
clearance in the
insulating jacket 31 defines an exposed portion 34 of the feed lead that is
adapted to contact
the piezoelectric fibers 19 (bristles 18). At a proximal end 33 of the feed
lead 28, a clearance
in the insulating jacket 31 defines an exposed portion 35 of the feed lead 28
that is adapted to
connect to the feed conductor 23 of the circuit 11, for example, by way of a
butt connector 56.
The return lead 29 may be formed from leg 15 of the U-shaped wire 13 of the
twisted wire
core 12. Alternatively, the return lead may be a separate structure. The wire
of the twisted
wire core 12 (i.e., legs 15 and 17 of the u-shaped wire 13) also has an
insulating jacket 36
covering substantially all of its length. At the distal end 22 of the twisted
wire core 12, a
clearance 37 in the insulating jacket 36 defines an exposed portion 38 of the
return lead 29.
At the proximal end 14 of the twisted wire core 12, a clearance in the
insulating jacket 36 on
the leg 15 defines an exposed portion 30 adapted to connect to the return
conductor 24, for
example, by way of a butt connector 57. It will be understood that the feed
lead 28 and feed
conductor 23 may be integrally formed as a single, freestanding wire or a
single conductor on
a printed circuit board, eliminating the need for butt connector 56.
Similarly, the return lead
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29 and return conductor 24 may be integrally formed as a single, freestanding
wire or a single
conductor on a printed circuit board, eliminating the need for butt connector
57. Electric
current is supplied, for example, from the battery 21 through the feed
conductor 23 into the
feed lead 28 through the exposed portion 35. The electric current is further
transmitted
through the feed lead 28 through the exposed portion 34 into the piezoelectric
bristles 19.
The current transmits through contacting adjacent piezoelectric bristles to
exit into exposed
portion 38 of the return lead 29 and continues through exposed portion 30 to
transmit into
return conductor 24, and through return conductor 24 to the battery, thus
completing the
circuit. When the electric current is applied to the piezoelectric bristles
19, the bristles 19
change at least one of shape, volume, rigidity or orientation.
In Figs. 5-7, the applicator head 2 is an injection molded mascara brush that
has a
molded applicator head 9 preferably having tines 27 extending from a body 39.
The tines 27
are adapted for loading, applying and doctoring a cosmetic such as, for
example, mascara.
The molded applicator head has a distal end 41 and, opposite the distal end
41, a proximal
end 40 that is adapted to connect the molded applicator head 9 to a rod 4
(similar to that
shown in FIG. 1). The rod 4 may be hollow to accommodate a feed conductor 23
and a
return conductor 24. The conductors 23, 24 may be placed in a lumen 42 running
along the
axis of the rod 4, i.e., inside the hollow stem. Referring now to Figs. 5-7,
the molded brush
head comprises two major components ¨ an outer part 43 and an inner part 44.
The outer
part 43 includes portions of the exposed surfaces of the brush head, including
the tines 27.
The inner part 44 forms a backbone of the brush head, supporting the outer
part 43, and is
made of an electrical insulator material. The outer part 43 comprises
piezoelectric material.
The inner part 44 may be made from any suitable material or materials, such
as, for example,
any suitable plastic or ceramic that forms a good electrical insulator. The
inner part 44 can be
made by conventional, well known means for molding plastic. The outer part 43
is made from
a piezoelectric material. The preferred method for making the outer part 43 is
ceramic insert
molding by ceramic injection molding (CIM), and from metal, the preferred
method is metal
injection molding (MIM). CIM and MIM are methods of powder injection molding.
Extremely
small (micro to nano scale) metal, ceramic or carbide powders are mixed into a
binder and
injected into the mold to form an initial shape. After the initial shape is
made, the binders are
chemically removed (e.g., with a solvent). The shape is then heated to a point
where the
powder material is sintered together without changing the initial shape.
Alternatively, the
molded brush head 9 may be manufactured by press molding, transfer molding,
compression
molding or other insert molding techniques, all of which are well known
methods of molding.
The outer part 43 can be overmolded onto the inner part 44.
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Ceramic and polymer parts or components for brushes that exhibit piezoelectric
properties can also be created using additive manufacturing processes.
Additive
manufacturing includes any process of joining materials to make objects from
three
dimensional model data. This process is typically layer based, with each layer
bound to the
layer before it via sintering, melting, binding (adhesive), aerosol jetting,
inkjet technology,
impact, and deposition of materials via energy waves and fields. Examples of
these
processes for additively manufacturing ceramics, metals, and polymers are SLS
(Selective
Laser Sintering), LENS (Laser Engineered Net Shaping), M3D (Maskless Mesoscale
Materials Deposition), EFAB Technology, Ultrasonic Consolidation, SLA
(Stereolithography),
FDM (Fused Deposition Modeling), Direct Metal Deposition, and EBM (Electron
Beam
Melting) for examples. As with conventional manufacturing process such as MIM
or CIM
mentioned before, the additive manufactured parts or components are preferably
also
subjected to a polarizing treatment to align the dipole moments in the
piezoelectric crystal
structures in the material.
In the embodiment shown in FIGS. 5 -7, there are two rows of tines 45 and 46
extending from one side of the brush head. However, it will be understood that
any suitable
number or arrangement of tines is possible. For example, in an alternative
embodiment
shown in FIGS. 8 and 9, explained in greater detail below, there are two rows
of tines 145
and 146, each row extending from an opposite side of the brush head. The tines
may be
arranged in straight rows or curved rows, such as, for example, a row of tines
that spirals
around a longitudinal axis of the applicator head (not shown). The tines may
be arranged in
one or more arrays, i.e., groups of tines that are electrically, conductively
connected to each
other. For example, in the embodiment shown in FIG. 6, each of the two rows
45, 46 of tines
may be an array of tines, 47, 48, respectively. Both tine arrays 47, 48 may be
connected to
the same circuit, or each tine array 47 and 48 may be connected to a separate
circuit so that
each tine array 47 and 48 can be selectively and separately activated and set
to a particular
durometer. In this way, each tine array 47 and 48 may be selectively and
individually set to
the same durometer or a different durometer.
At the proximal end 40 of the applicator head 2, a reduced diameter portion
defines a
pin 49 dimensioned to be received in the bore 16 of the rod 4 to secure the
applicator head 2
to the rod 4. The pin 49 can be secured in the bore 16 by any known means,
such as, for
example, adhering, friction fit, sonic welding, etc.
From proximal end 40 the outer part 43 extends along a lower side of the
applicator
head 2 to the distal end 41 where it wraps around the distal end and extends
along the upper
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side back to the proximal end 40. The tines 27 are integrally formed with the
portion of the
outer part 43 that extends along the upper side of the applicator head 2. On
the lower side of
the applicator head 2 a portion of the outer part 43 of the body serves as the
feed lead 28
while a portion of the outer part 43 on the upper side of the applicator head
2 serves as the
return lead 29. The feed lead 28 is adapted to be connected to the feed
conductor 23 by butt
connector 56. Similarly, the return lead 29 is adapted to be connected to the
return conductor
24 by butt connector 57. The electrical circuit from the power source 5 is
completed by
connecting the feed conductor 23 to the feed lead portion 28 of the outer part
43, and
connecting the return conductor 24 to the return lead portion 29 of the outer
part 43. In this
way, electricity flows from the feed conductor 23 into the outer part 43 where
it is applied to
the tines 27. From the outer part 43 the current flows back to the return
conductor 24 to
complete a loop. The purpose of this loop is to run an amount of electrical
current through
the piezoelectric ceramic material of the tines 27 to effect the change in the
material, such as,
for example, changing the durometer of each tine. For example, a useful
cosmetic applicator
durometer could be selected to begin (static and without current) at 72 Shore
D durometer.
This would be the maximum stiffness of each brush tine as determined by the
selection of the
piezoelectric material in combination with the molded material of the
applicator portion.
In Figs. 8-9, the applicator head 2 is an injection molded mascara brush that
has a
molded applicator head 109 preferably having tines 127 extending from a body
139. The
tines 127 are adapted for loading, applying and doctoring a cosmetic such as,
for example,
mascara. The molded applicator head has a distal end 141 and, opposite the
distal end 141,
a proximal end 140 that is adapted to connect the molded applicator head 109
to a rod 4.
The rod 4 may be hollow to accommodate a feed conductor 23 and a return
conductor 24.
The conductors 23, 24 may be placed in a lumen 42 running along the axis of
the rod, i.e.,
inside the hollow stem. Referring now to Fig. 9, the molded brush head
comprises two major
components ¨ an outer part 143 and an inner part 144. The outer part 143
includes portions
of the exposed surfaces of the brush head, including the tines 127. The inner
part 144 forms
a backbone of the brush head, supporting the outer part 143, and is made of an
electrical
insulator material. The outer part 143 comprises piezoelectric material. The
inner part 144
may be made from any suitable material or materials, such as, for example, any
suitable
plastic or ceramic that forms a good electrical insulator. The inner part 144
can be made by
conventional, well known means for molding plastic. The outer part 143 is made
from a
piezoelectric material. The preferred method for making the outer part 143 is,
from ceramic,
insert molding by ceramic injection molding (CIM), and from metal, the
preferred method is
metal injection molding (MIM). CIM and MIM are methods of powder injection
molding.
Extremely small (micro to nano scale) metal, ceramic or carbide powders are
mixed into a
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binder and injected into the mold to form an initial shape. After the initial
shape is made, the
binders are chemically removed (e.g., with a solvent). The shape is then
heated to a point
where the powder material is sintered together without changing the initial
shape.
Alternatively, the molded brush head 109 may be manufactured by press molding,
transfer
molding, compression molding or other insert molding techniques, all of which
are well known
methods of molding. The outer part 143 can be overmolded onto the inner part
144.
In the embodiment shown in FIGS. 8 and 9, there are two rows of tines 145 and
146,
each row extending from an opposite side of the brush head. However, it will
be understood
that any suitable number or arrangement of tines is possible. For example, in
an alternative
embodiment shown in FIGS. 5 and 6, explained in greater detail above, there
are two rows of
tines 45 and 46, each row extending from the same side of the brush head. The
tines may be
arranged in straight rows or curved rows, such as, for example, a row of tines
that spirals
around a longitudinal axis of the applicator head (not shown). The tines may
be arranged in
one or more arrays, i.e., groups of tines that are electrically, conductively
connected to each
other. For example, in the embodiment shown in FIGS. 7 and 8, each of the two
rows 145,
146 of tines may be an array of tines, 147, 148, respectively. Both tine
arrays 147, 148 may
be connected to the same circuit, or each tine array 147 and 148 may be
connected to a
separate circuit so that each tine array 147 and 148 can be selectively and
separately
activated and set to a particular durometer. In this way, each tine array 147
and 148 may be
selectively and individually set to the same durometer or a different
durometer.
At the proximal end 140 of the applicator head 2, a reduced diameter portion
defines a
pin 149 dimensioned to be received in the bore 16 of the rod 4 to secure the
applicator head
2 to the rod 4. The pin 149 can be secured in the bore 16 by any known means,
such as, for
example, adhering, friction fit, sonic welding, etc.
From proximal end 140 the outer part 143 extends along a lower side of the
applicator
head 2 to the distal end 141 where it wraps around the distal end and extends
along the
upper side back to the proximal end 140. The tines 127 are integrally formed
with the portion
of the outer part 143 that extends along the lower and upper side of the
applicator head 2.
The outer part 143 of the body serves as both the feed lead 28 on the one side
of the
applicator head 2 and the return lead 29 on the opposite side of the
applicator head. The
feed lead 28 is adapted to be connected to the feed conductor 23. Similarly,
the return lead
29 is adapted to be connected to the return conductor 24. The electrical
circuit from the
power source 5 is completed by connecting the feed conductor 23 to the feed
lead portion 28
of the outer part 143, and connecting the return conductor 24 to the return
lead portion 29 of
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the outer part 143. In this way, electricity flows from the feed conductor 23
into the outer part
143 where it is applied to the tines 27 on both sides of the applicator head
2. From the outer
part 143 the current flows back to the return conductor 24 to complete a loop.
The purpose of
this loop is to run an amount of electrical current through the piezoelectric
ceramic material of
the tines 27 to effect the change in the material, such as, for example,
changing the
durometer of each tine. For example, a useful cosmetic applicator durometer
could be
selected to begin (static and without current) at 72 Shore D durometer. This
would be the
maximum stiffness of each brush tine as determined by the selection of the
piezoelectric
material in combination with the molded material of the applicator portion.
As noted above, the control 25 may be in the form of a simple bipole switch to
selectively turn on or turn off the electric current. Alternatively, the
control 25 may be a
potentiometer or rheostat 55 to control resistance (this can also function as
a position
determining transducer for large changes in durometer). For example, as the
control 25 in
the form of a rheostat 55 is adjusted after the circuit is activated, and
electric current is
passed through the piezoelectric material in quantities selected according to
the rheostat 55,
the material softens respectively. Accordingly, the user may dial down to, for
example, a
durometer of 20 Shore A (very soft and flexible) more suitable for application
purposes. After
applying cosmetic with the relatively softer diameter, the rheostat could be
re-adjusted by the
user to, for example, yield a durometer of 72 Shore D to achieve a relatively
stiffer applicator
more suitable for combing and separation of lashes. The higher durometer in
the Shore D
range would still allow the applicator to pass through a wiper and wipe
effectively, but the
ability to drop the durometer into the Shore A range can give specific
abilities that a more rigid
brush does not have (especially after being inundated in the mascara and then
passed
through the mascara wiper). For example, a stiffer brush may be able to
lengthen and curl,
but not volumize especially well. A softer brush may load and deposit more
product and
therefore volumize more effectively, but may yield more clumps or may not be
able to "touch
up" as well as a stiff brush can. Being able to selectively dial between
durometers allows the
user to approach conditional or progressively changing application situations
with an inherent
flexibility that a single conventional brush cannot provide. An example of
this kind of flexibility
would be to be able to adjust the brush to execute different steps in the
application process.
A first step could be volumizing and loading the lashes with mascara, which
could benefit
from a soft brush. The second step is to curl the lashes, which could benefit
from a stiffer
durometer, and the third step could be to separate the lashes with a very
stiff durometer
(which by itself would be very inefficient for loading the lashes in that it
would pull most of
what it loaded away because of its stiffness.
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While discussed in the context of piezoelectric materials above, other
materials may
be capable of providing selectively reactive changes in durometer, shape,
volume or
orientation. The term "selectively reactive material" as used herein means any
material
adapted to change structurally at least one of shape, volume, rigidity or
orientation in
response to application or removal of a quantity of energy. For example, the
selectively
reactive material may be a piezoelectric, ferroelectric or pyroelectric
reactive material. See,
for example, descriptions of selectively reactive materials in the book Solid
State Physics:
Advances in Research and Applications Volume 27, 1972 by Frederick Seitz,
incorporated
herein by reference in its entirety. Examples of materials that exhibit
ferroelectric properties
are certain nylons (e.g., Nylon 5,10), Polytrifluoroethylene, and
Polyvinylidene Fluoride
(PVDF), and Poly(methyl) methacrylate (PMMA). Examples of pyroelectric
materials are
those including polar crystals. The pyroelectric effect occurs when these
crystals are heated
or cooled, changing the polarity of the crystal, which creates a voltage
across the crystal.
Specific examples of materials that exhibit the pyroelectric effect are
tourmaline, bone and
tendon. The piezo materials used could have a positive piezoelectric
coefficient (e.g., PZT)
or a negative coefficient (e.g., PVDF).
Accordingly, in one embodiment, the applicator that is adapted for applying a
cosmetic
product, such as mascara, comprises a handle and an applicator portion
extending from the
handle. The applicator portion has an applicator structure including at least
one selectively
reactive material selected from a piezoelectric, ferroelectric or pyroelectric
reactive material.
The reactive material is adapted to change at least one of shape, volume,
rigidity and
orientation of the applicator structure in response to application or removal
of an appropriate
quantity of energy. Means for supplying or removing the quantity of energy are
also provided,
as well as control means for selectively controlling the quantity of energy
supplied to or
removed from the selectively reactive material. Preferably, the selectively
reactive material is
a piezoelectric material, and more preferably, the piezoelectric material is a
ceramic-
piezoelectric material.
In accordance with the invention, the applicator portion may comprise any
applicator
structure that is suitable for application of cosmetic products, such as, for
example, a brush
with bristles, a wand, a spatula, a puff, a comb, or a roller. As used herein,
the term
applicator structure can include the entire applicator portion as in any of
the foregoing
examples, or can refer to any part of the applicator portion, such as, for
example, a tine of a
molded brush, a bristle of a twisted wire brush, a surface of a spatula or
roller, or a porous
structure of a puff, in whole or in part. The applicator portion may have a
surface or surfaces
that are adapted for loading, transporting, applying, exfoliating, buffing,
finishing and
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polishing. The surface may be enhanced with clearances, grooves, stippling,
etc. to facilitate
the loading, transport and application of cosmetic product.
The quantity of energy is selected from one of electrical, kinetic, thermal,
magnetic or
light energy. A ferromagnetic material has a permanent magnetic moment. The
moment of a
ferromagnetic material is present even in the absence of an external magnetic
field affecting it
(like a household magnet). The quantity of energy may be supplied, for
example, as an
alternating or direct current directly to the reactive material, or the energy
may be supplied as
an energy field, e.g., an electrical or magnetic field established via known
circuits or
components such as coils. When the piezo material is a light activated shape
memory
polymer (LASMP), optical energy may be provided in the form of light from an
incandescent
bulb, a laser, a light emitting diode (LED) or other suitable light source.
The piezoelectric material may be provided in the form of at least one fiber.
The
material may alternatively be provided in sheet-like form or as a laminate or
bar stock, shapes
that are very conducive to specifically directing how the materials will move
and react to
external forces placed upon them after durometer changes take place. The
fibers involved
can be any shape profile as well. This could be a bar, "C" or "U" shape,
sigmoidal, tube,
triangular or trilobal, square, any other polygon, etc.
The handle 6 may be attached to the applicator portion by a rod 4. The rod may
be
hollow, with a lumen 42 to provide an internal channel to run conductors,
circuit, a circuit
board or circuit boards between the handle and the applicator head 2.
Alternatively, the rod 4
may be substantially solid and over-molded onto the conductors, circuit,
circuit board, etc.
The applicator head 2 may be selectively removable from the handle 6, at
either end
of the rod 4 or at the handle. The applicator head 2 may be removable so that
it is
replaceable. Or alternate applicator heads 2 may be provided with the handle 6
in a kit so
that a single handle 6 can be used with, for example, a brush applicator
portion, a spatula
applicator portion, etc.
The control means 25 is selected from at least one of a switch, a
potentiometer, a
rheostat and an integrated circuit. The integrated circuit may be adapted to
selectively
provide the quantity of energy in continuous or pulsed mode, i.e., the current
and frequency
are controlled. The pulsed mode may be uniform or cyclical (this is
continuous), gradual
(increasing or decreasing), or syncopated (rhythmic, containing strong or weak
accents
and/or rests).
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There are several different flexible ceramic configurations possible for an
applicator.
A mascara applicator is described herein, but other types of applicators and
cosmetic
surfaces such as brushes, wands, spatulas, puffs, combs, exfoliating,
depilatory, buffing,
finishing, or polishing surfaces for example, could incorporate the reactive
material in any
number of ways. For example, a spatula could have at least one surface made
from a sheet
of reactive material. The material could be so arranged as to cause the
spatula to 'cup' or
flatten, or display a degree of change in stiffness or flexibility in response
to the changes in
current.
For mascara application, the applicators can be constructed much like a
conventional
twisted wire brush, i.e., they may be composed of multiple extruded fibers
that are twisted
conventionally along an axis into a brush. A power source and circuits are
added to effect the
change. If fibers are used, the brush can be purely piezoelectric (e.g.,
ceramic) fibers, or a
mix of piezoelectric and conventional fibers for specific effects. The
electricity to the
piezoelectric material of the extruded fibers can be achieved by attaching one
of the two wires
from the handle or stem to the distal end of the mascara brush, with the other
wire attached to
the base of the wire embedded within the handle or stem.
The applicator could consist of one or more flexible ceramic rows or arrays of
tines,
teeth, threaded surfaces, or other geometries conducive to application. These
tines or teeth
could be microns in length and/or width up to 30mm in length. The applicator
could have
conventional plastic tines that do not change durometer which are embedded in
flexible
ceramic surfaces that will allow the tines to "float" as the durometer is
changed by the addition
of energy. The flexible surfaces are the foundation that the rigid tines are
supported in.
When energy is added, the foundation can become softer or harder allowing the
tines to
function independently when acted upon. This foundation material could be a
constant
thickness or density across the area that the tines are placed, or it could
gradually increase,
decrease, or otherwise have a changing condition that would allow the tines to
have different
levels of mobility.
The applicator can be fully composed of flexible ceramic material, or be a
hybrid
containing conventional materials (thermoset and/or thermoplastic polymers and
elastomers,
metals, etc.) mixed with flexible ceramic components. This hybrid could be
created by bi-
injection (plastic and piezoelectric ceramic), insert molding (plastic around
a piezoelectric
ceramic part), or by assembly (a plastic tube within the piezoelectric
ceramics or piezoelectric
ceramics with a plastic tube or clearance). Additional plastics and elastomers
that can be
used could be polyolefins, fluoropolymers, and vinyls as well.
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The durometer range that can be applied could be any range within the Shore A
Durometer range (softer), the Shore D Durometer range (harder), the Rockwell
Hardness
region of measurement (hardest) or any durometer emulation across any
combination of the
previously mentioned ranges. Examples of "hardness" are: Shore hardness
applies to softer
or more flexible plastics, rubbers and elastomers; and Rockwell Hardness
applies to
measuring "harder" plastics such as Nylon, Acetal (Delrin), Polystyrene (PS),
or
Polycarbonate (PC).
When the selectively reactive material is, for example, piezoelectric
material, it
functions either by the piezoelectric effect or via the inverse piezoelectric
effect. The
piezoelectric effect is where the materials of the applicator are subject to
expansion and
compression that causes the material to become polarized, and generate
voltages of opposite
polarity; any energy generated is proportionate to the mechanical force
applied to the
material. Voltage is created by a change in the dipole movement by mechanical
energy
applied to the material.
The inverse piezoelectric effect occurs when the applicator material is
subject to an
electrical field, and the material actually expands or contracts based on the
field's polarity,
and this effect is also proportionate to the strength of the electrical field.
For the best mode
(inverse piezoelectric effect) we would apply a voltage of the same polarity
as the polarizing
voltage of the material (this is the voltage applied to the "inert" ceramic
(for example) material
to make it piezoelectric) to the material. When this voltage is applied to a
mascara brush
fiber, its length will increase and the diameter of the fiber will narrow
accordingly. If the same
voltage is applied but with the opposite polarity, the brush fiber will
shorten, and the diameter
of the fiber would expand (broaden or bulge) with the change. In short,
electrical energy is
converted into mechanical energy that manipulates the mascara brush. An
interesting aspect
of this application could be to apply an alternating voltage to the fibers,
which would cause
them to expand and contract, or increase and decrease durometer cyclically at
the frequency
of the voltage that we would apply. This is basically how piezoelectric motors
work, but in this
case we are applying it to mascara brush fibers.
The piezoelectric material may have a defined natural frequency that is
determined by
its shape and size. This frequency is how the material naturally tends to
oscillate, and this
frequency can be changed by electrical current (voltage changes vibration
amplitude). The
selectively reactive material could comprise any crystalline material that
represent any of the
thirty two crystal classes. Twenty-one of these crystal classes (crystalline
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groups) have direct piezoelectric effects and would represent what is likely
the composition of
the best types of materials for this purpose. The 21 crystal classes are 1, 2,
m, 222, mm2, 4,
4, 422, 4 mm, 42m, 3, 32, 3m, 6, 6, 622, 6 mm, 62m, 23, 43m and 432.
The selectively reactive material incorporated in the bristles, tines or other
structure
can be affected by either a sustained electric field, or a pulsed field that
can create direct and
converse piezoelectricity to create an oscillating effect in the durometer
change.
Some suggested selectively reactive materials that would be suitable for the
present
invention include:
Naturally occurring materials: Bone, Enamel, Dentin, Wood (piezoelectric
texture),
Silk, Topaz, Quartz, Cane Sugar, Berlinite, Rochelle Salt, Tourmaline-Group
materials;
Synthetically materials: Langasite (La3Ga5Si014) and Gallium Orthophosphate
(GaPO4) (both are synthetic quartz crystals);
Ceramics: Barium Titanate (BaTiO3), Lead Titanate (PbTiO3), Lead Zirconate
Titanate (PbZrTiO3) aka PZT, Potassium Niobate (KNb03), Lithium Niobate
(LiNb03),
Lithium Tantalate (LiTa03), Sodium Tungstate (Na2W03), Ba2NaNb505, Pb2KNb5015,
Sodium Potassium Niobate (NaKNb), Bismuth Ferrite (BiFe03), Sodium Niobate
(NaNb03);
Polymers: Polyvinylidende Fluoride (PVDF).
There are several possible methods/configurations to manipulate the
applicator. For
example, the durometer/flexibility of the brush can be adjusted by a simple
single or bi-pole
switch (off/on), or multiple poles and/or multiple throw switches with several
different current
settings. Alternatively, the durometer/flexibility of the brush can be
adjusted by a
potentiometer or rheostat, or digitally by an integrated circuit. An
integrated circuit or other
suitable electronic control could be used to manipulate the durometer,
including in a pulse,
pattern or program of energy delivery that would cause the durometer to change
as a
frequency. This pulse could have consistent frequency intervals, could
increase or decrease
over time (gradual), or be syncopated (rhythmic stresses and/or rests). This
pulsing
frequency will not function as a free standing "vibration" (only the
flexibility is changing) but
the effects of the durometer change will be apparent when contact by the
tines, tips, or
bristles contact the eyelashes, and the force of the eyelashes effects
movement on the
dynamically changing flexibility of the mascara brush. The changes would be
proportionate
to the measurement of the material's electric dipole moment (a measure of the
system's
overall state of polarity).
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Alternatively, the durometer could be changed by magnetism (electromagnetic
field) ¨
introducing a magnetic field, and/or reversing polarity can be methods to
change the flexibility
of the applicator.
Power can be supplied to the applicator using batteries, solar power, kinetic
power
(from a piezo effect by bending, vibration, agitation, etc. of piezo based
materials), or from
other suitable sources, such as a connection to a commercial power grid.
Cosmetic applicators are often created as a matrix of several different
applicator
surfaces, whether they are tines, bristles, discs, etc., and for these shapes,
different
durometers of material may be selected within a predicted range. To create
effective
applicators for more customer specific needs (ethnographic, genetic,
application specific like
volumizing or curling, etc.), a manufacturer would be required to produce many
different
levels of flexibility in the applicator components. Offering too many levels
of choice reduces
manufacturing efficiency, and may lead to consumer confusion as to what is
best for a
particular need. The present invention provides the consumer flexibility in
terms of selecting
a particular durometer brush, while limiting the number of variations a
manufacturer must
produce. The present applicator allows manipulation by the user of the
durometer of
cosmetic applicators that is dynamic and interactive. The user can choose an
appropriate
setting and either stay with this setting, or change settings depending on
changing needs
through out the course of a day, over multiple applications, the life of the
product, etc. In
terms of manufacturing, only one version is produced, because the device is
infinitely
customizable in the hands of the consumer.
Being able to change the durometer of a cosmetic applicator allows for a
consumer-
specific customizable application. For example, a mascara brush can be
adjusted to lengthen
and separate at a stiffer durometer setting, and volumize and load the lashes
with mascara at
a lower durometer setting. Other benefits could include different levels of
skin care from skin
exfoliation at high durometer settings to skin conditioning and finishing at
low durometer
settings.
The method to dynamically adjust durometer on a cosmetic applicator may be
used
for cosmetic/treatment/pharmaceutical packages such as mascaras, eye liner,
eye shadow,
lip gloss, treatments, hair care, sun protection/tanning, foundations,
concealers, hand or body
creams, nail polish, exfoliants and skin care applications.
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It is understood that various modifications and changes in the specific form
and
construction of the various parts can be made without departing from the scope
of the
following claims.
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