Brush for applying a cosmetic product and make-up device comprising it

A brush which includes a straight wand defining a major axis; a flexible core which defines the length of the brush, the core including a first end and a second end, the first end being secured to the wand. A plurality of bristles are inserted radially into this core, the end of the bristles defining an envelope surface of the brush, the envelope surface having a first end and a second end, wherein the core is curved in a plane of curvature and the envelope surface of the brush over at least part of its length has a cross-section of elongate shape in the direction of an axis of greatest length perpendicular to the plane of curvature.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The invention relates to a brush, particularly a brush for applying the 
cosmetic product to keratinous fibers, especially for applying mascara to 
the eyelashes or a dye to the hair, and to a make-up device comprising 
this brush, the brush having a curved core. 
2. Discussion of the Background 
A brush for applying a cosmetic product customarily comprises an elongate 
core, formed by a helical twist of two branches of a metal wire which has 
been bent into a U before the branches were twisted, and bristles inserted 
radially into this core and gripped between these twisted branches. Such 
brushes may be of various shapes and have cutouts. 
When these brushes are used to apply mascara to the eyelashes, such shapes 
and such cutouts are designed to make it up possible to obtain a heavier 
or lighter make-up effect, with varying amounts of lengthening and of 
curling of the eyelashes. 
Brushes in the shape of a fragment of a torus are known, these brushes 
being obtained by twisting the core of a cylindrical brush into an arc of 
a circle. Such brushes have a convex face, a concave face, and two more or 
less flat faces. Such brushes are not very easy to handle because if the 
user twists the wand of such a brush about its axis between her fingers in 
order, for example, to apply a product to her eyelashes, she has to 
continually correct the distance between the brush and the eyelashes. With 
these brushes, it is difficult to apply make-up in the comer of the eye 
without overspill onto the eyelid and the side of the nose. Furthermore, 
it has been observed that such a brush tends to coat the eyelashes without 
spreading the product out very much. Brushes obtained by twisting the core 
of a cylindro-conical brush into a circular arc display the same 
drawbacks. 
SUMMARY OF THE INVENTION 
It has therefore become desirable to have use of brushes that allow the 
eyelashes to be engaged fully by the brush in order to spread out the 
product correctly and separate the lashes properly. Another object of the 
invention is to provide a brush which is still simple and economical to 
apply and practical to use. 
The present invention is based on the discovery of novel brushes for 
applying a cosmetic product which, when used to apply mascara to the 
eyelashes, make it possible to obtain a make-up effect with a great deal 
of curling and lengthening and with a product spread out along the entire 
length of the lash. These brushes are, moreover, very easy to handle and 
allow make-up to be applied with ease to the corner of the eye. 
An object of the invention is to provide a brush comprising a straight wand 
defining a major axis (X--X); a flexible core which defines the length of 
the brush, this core comprising a first end and a second end, the first 
end being secured to the wand; a plurality of bristles inserted radially 
into this core, the end of the bristles defining an envelope surface of 
the brush, this envelope surface having a first end and a second end, the 
brush being characterized in that the core describes a curve (C) in a 
plane of curvature (P) and in that the envelope surface of the brush over 
at least part of its length has a cross section of elongate shape in the 
direction of an axis of greatest length (Z--Z) perpendicular to the plane 
of curvature (P). 
The cross-section of the envelope surface is intended to mean a section 
through the envelope surface on a plane perpendicular to the core. 
Preferably the curve (C) is more or less circular. That part of the brush 
which is in the concave part f the curve (C) forms a hollow. That part of 
the brush which is on the opposite side forms the back of the brush. As 
the cross-sections of the envelope surface of the brush are elongate, in 
the direction of the axis of greatest length, in the direction 
perpendicular to the plane (P) of twisting of the core, the brush 
according to the invention has two broad flattened faces, one being in the 
hollow of the brush and the other in the back of the brush. The face that 
is in the hollow of the brush is very close in shape to the contour of the 
eyelashes. Furthermore, it contains short and therefore not very flexible 
bristles. It can therefore engage the eyelashes along the entire width of 
the eyelid, coat them with product, lengthen them and curl them. As the 
distance between the two faces is shorter than the width of the brush, the 
brush can slip easily into the comer of the eye to apply make-up to the 
eyelashes without overspill around the comer of the eye. The sides of the 
brush, which have longer, and therefore more flexible, bristles than the 
faces, but which are not as wide, give very effective combing and 
separation of the lashes. The back of the brush, just like the hollow, 
allows the make-up or care product to spread by engaging the lash over a 
significant portion of the length of the lash. As this back is domed, it 
encourages the curling of the lash. 
The very pronounced and markedly differing characteristics of the faces and 
of the sides give this brush a surprising dynamic behavior. When the user 
turns the brush between her fingers, the lashes are alternately coated and 
curled, then combed out with uncustomary intensity. 
Preferably, the core is central with respect to each cross-section. 
In a first alternative form of the invention, provision may be made for the 
cross-section to have at least two sides in the direction of the axis of 
greatest length (Z--Z), these sides being more or less parallel to the 
axis (Z--Z). 
In a second alternative form of the invention, provision may be made for 
the cross section to have at least two sides in the direction of the axis 
of greatest length (Z--Z), these sides having a convex shape. According to 
this alternative form, provision may be made for the sides of the cross 
section to have two ends, the width of the section in the direction of the 
axis (Y--Y) perpendicular to the axis of greatest length (Z--Z) at these 
ends being more or less zero. 
Irrespective of the alternative form of the invention, it is preferable for 
the cross-section to have at least two sides in the direction of the axis 
(Y--Y), this axis being perpendicular to the axis of greatest length 
(Z--Z), these sides having a convex shape. 
Advantageously, the cross -section has a maximum width (D) in the direction 
of the axis of greatest length (Z--Z) and a maximum width (d) in the 
direction of the axis (Y--Y), widths D and d satisfying the relationship: 
EQU D&gt;1.5d 
More preferably still, D and d satisfy the relationship: 
EQU D&gt;2d 
The longer length D can vary along the core. In order to make the make-up 
characteristics described hereinabove more pronounced, brushes in which 
the envelope surface has an elongate cross section over at least 50% and 
preferably 75% of its length are preferred. 
Advantageously, the brushes according to the invention are designed in such 
a way that, for each cross section, the axis of greatest length and the 
axis of greatest width are perpendicular. 
For greater ease of handling, provision is preferably made for the ends of 
the core to be aligned with the axis X--X. 
Another object of the invention is to provide a method of manufacturing a 
brush as described hereinabove, the method being characterized in that it 
comprises the following steps: 
(i) producing a starting brush comprising a straight wand defining a major 
axis (X--X); a flexible core which defines the length of the brush, this 
core comprising a first end and a second end, the first end being secured 
to this wand, the core being straight and aligned with the wand, the 
bristles thereof being inserted radially into this core with the end of 
the bristles defining an envelope surface of the starting brush. 
(ii) trimming the bristles of the starting brush in such a way that the 
envelope surface of the brush over at least part of its length has a cross 
section of elongate shape in the direction of an axis of greatest length 
(Z--Z), 
(iii) giving the core a main twist in the plane perpendicular to the axis 
of greatest length (Z--Z) and passing through the wand. 
Preferably, in a fourth step: 
(iv) a secondary twist is given to that end of the core which is secured to 
the wand in order to align the second end of the core with the main axis 
(X--X). 
Steps (i) and (ii) are preferably carried out in such a way that the core 
is central with respect to the faces of the straight trimmed brush. 
The starting brush is preferably trimmed in such a way that the envelope 
surface has an elongate cross-section over at least 50% and preferably 75% 
of its length. 
In a preferred embodiment of the invention, step (iii) is carried out in 
such a way as to give the core a more or less circular main twist. 
Furthermore, the bristles of the brushes according to the invention may be 
of any kind: bristles of different lengths, of different diameters or of 
different sections and of different materials, bristles with tapered ends, 
with forked ends, or shaped like a hairpin, or bristles that have 
undergone any sort of treatment known to those skilled in the art. 
Provision may also be made for the brush according to the invention to 
contain alternating rows of short bristles and of long bristles, only the 
long bristles being involved in defining the envelope surface of the 
brush. This kind of alternative form of the invention makes it possible to 
accentuate the coating of the eyelash with product by the brush of the 
invention. 
The helical twisting of the two branches of metal wire that forms the core 
may be with a right-hand twist as is customarily practiced in the 
manufacture of make-up brushes, or with a left-hand twist, as per the 
teachings of French patent application 2701198. To manufacture a brush 
with a left-hand twist, the branches of the core are twisted by turning to 
the left to form turns that turn in the clockwise direction about the core 
in a direction from the wand towards the end of the brush. 
Another object of the invention is to provide a make-up device comprising a 
mascara reservoir and a mascara-applicator member as described 
hereinabove. 
Owing to its special shape, when the brush passes through a wringing 
device, its sides are very well wrung out, while its faces are wrung out 
to a lesser extent. In particular, the faces are wrung asymmetrically on 
account of their curvature. This special feature allows the user, 
depending on which of the faces she uses, to apply make-up with a 
heaviness and intensity that can vary along the entire length of the 
eyelid. 
The flexibility of the bristles and the flexibility of the core can be 
altered to encourage or discourage wringing-out of the brush.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The brush 100 depicted in FIGS. 1 and 1A comprises a straight wand 101 
defining a main axis X--X. Fixed by force-fitting to the end 101.1 of this 
wand 101 is a core 102 (which has been depicted in these figures even 
though it is inside the brush) which is elongate, formed by the helical 
twisting of two branches of a metal wire 103 which has been bent into a U 
before the branches were twisted. The axis of the core 102 coincides with 
the main axis X--X. Bristles 104 are inserted radially between the 
branches of the wire 103. When the branches of the wire 103 are twisted, 
the bristles are clamped and held between the helical turns of the core 
102. The ends of the bristles 104 define the surface 105 of the brush. 
This is a convex axisymmetric surface which has the shape of a rugby ball 
and the ends of which consist of two right cross-sections: the disk 106.a 
with a center 108.a and the disk 106.b with a center 108.b. 
Using a trimmer, two more or less flat parallel faces are cut in the brush 
of FIG. 1A over practically the entire length (measured along the axis 
X--X) of the brush. Depicted in FIG. 1A is the intersection (.gamma.) 
between the surface 105 of the brush and the trimming plane. This yields a 
trimmed brush depicted in FIGS. 1B and 1C. 
For elements of FIGS. 1B and 1C which are common to those of FIG. 1A, the 
reference numbers in FIGS. 1B and 1C are the same as those in FIG. 1A, 
increased by 10. 
The brush depicted in FIGS. 1B and 1C has two mutually parallel faces 119 
which are also parallel to the axis X--X. These two faces are equidistant 
from the core 112. The distance between the two faces is represented by 
the symbol d. The two faces are joined by rounded edges 120. In the region 
where the faces 119 have cutouts, the sections of the brush on a plane 
perpendicular to X--X consist of curves 115C depicted in FIG. 1C which are 
more or less rectangular, with a long length D in the direction of the 
axis of greatest length Z--Z and the greatest width d measured along the 
axis of greatest width Y--Y with D&gt;1.5d. The two faces do not extend as 
far as the ends 117a and 117b of the brush. At these ends, the sections 
116a, 116b of the brush are circular wherein a width dimension of a 
cross-section in the direction of an axis perpendicular to the axis X--X 
at these ends is substantially zero. The curve 115C is symmetric with 
respect to the axis of greatest length Z--Z and the axis of greatest width 
Y--Y. 
Using an appropriate tool, for example by pressing the core longitudinally 
around a metal cylinder, the core 112 is given a first twist in the plane 
perpendicular to the faces 119 between the sections 116.a and 116.b, in 
such a way that the core has more or less the shape of an arc of a circle, 
and then it is given a second twist, in the same plane, between the end 
111.1 of the wand and the center 118.a of the end section of the brush, so 
as to align the center 118.b of the other end of the brush with the main 
axis X--X, like the first end 118.a. 
This operation yields a brush 120 according to the invention and depicted 
in FIGS. 1D and 1E. In these figures, the reference numbers given to 
elements which are similar to those in FIGS. 1B and 1C are those of FIGS. 
1B and 1C increased by 10. 
The brush in FIGS. 1D and 1E is more or less in the shape of an elongate 
spoon. The core 122 describes a curve C.sub.1 which is more or less an arc 
of a circle. However, its ends 128.a and 128.b are aligned with the main 
axis X--X. The brush comprises two faces 129a, 129b, one of them, 129a, 
forming the back and the other face, 129b, forming the hollow bowl of the 
spoon. These two faces are joined by rounded edges 120. The surface 125 of 
the brush is generated by a series of curves 115c, as depicted in FIG. 1C, 
which progress along the core 122. These curves are more or less 
rectangular, with their axes of greatest length (Z--Z) being mutually 
parallel. At its ends 127a, 127b, the brush is generated by circular 
curves. 
FIG. 2A is differentiated from FIG. 1A by the fact that the surface 205 of 
the starting brush is in the shape of a cone frustum. 
Using a trimmer, two secant rounded faces are cut in the brush of FIG. 2A 
along the entire length (measured along the axis X--X) of the brush. This 
yields a trimmed brush depicted in FIGS. 2B and 2C. 
For elements of FIGS. 2B and 2C which are common to FIG. 2A, the reference 
numbers in FIGS. 2B and 2C are the same as those in FIG. 2A increased by 
10. 
The brush depicted in FIGS. 2B and 2C has two rounded and secant faces 219. 
These two faces are symmetric with respect to the core 212. The width 
between the extremes of the two faces is represented by symbol d. Width d 
is more or less constant from one end of the brush to the other. The two 
faces are joined by edges 220 which end in ridges 220a. The sections of 
the brush on a plane perpendicular to X--X consist of curves 215c depicted 
in FIG. 2C which are more or less eye-shaped, with the long length D along 
the axis of greatest length Z--Z and greatest width d measured along the 
axis of greatest width Y--Y. D increases from a first end 216b as far as a 
second end 216a with D&gt;2d on the curve 215c depicted in FIG. 2C. The two 
trimmed faces extend as far as the end sections 216a and 216b of the 
brush. The curve 215c is symmetric with respect to the axis of greatest 
length Z--Z and the axis of greatest width Y--Y. 
Using an appropriate tool, for example by pressing the core longitudinally 
around a metal cylinder, the core 212 is given a first twist in the plane 
perpendicular to the faces 219 between the sections 216.a and 216.b, in 
such a way that the core has more or less the shape of an arc of a circle, 
and is then given a second twist, in the same plane, between the end 211.1 
of the wand and the center 218.a of the end section of the brush, so as to 
align the center 218.b of the other end of the brush with the main axis 
X--X, like the first end 218.a. 
This operation yields a brush 200 according to the invention and depicted 
in FIG. 2D. In this figure, the reference numbers given to elements that 
are similar to those in FIGS. 2B and 2C are those of FIGS. 2B and 2C 
increased by 10. 
The brush in FIG. 2D is more or less in the shape of an elongate spoon; the 
core 222 describes a curve C.sub.2 which is more or less an arc of a 
circle. However, its ends 228.a and 228.b are aligned with the main axis 
X--X. The surface 225 of the brush comprises two faces 229a, 229b, one of 
them, 229a, forming the back and the other, 229b, forming the hollow bowl 
of the spoon. These two faces are joined by a ridge 230a. The surface 225 
of the brush is generated by a series of curves 215 as depicted in FIG. 
2C, which progress along the core 222. These curves are more or less 
eye-shaped, with their axes of greatest length (Z--Z) mutually parallel. 
In the two embodiments of the invention described hereinabove, use was made 
of starting brushes with the shape of a rugby ball and a frustoconical 
shape, but it is also possible to use an elongate starting brush with a 
shape chosen from: a cylinder, two cones joined together by the bases of 
the two identically-sized cones, a fish as described for example in the 
French patent application FR-A-2730910, a peanut, an obus (shell shaped) 
or a teardrop. 
The device for applying make-up to the eyes depicted in FIG. 3 comprises a 
cylindrical reservoir 320 which has a threaded neck 324 surmounted by a 
seal 325 and which is full of a mascara 315. In its neck, the reservoir 
320 has a wringing device 321, the wringing device being held in position 
in the neck by a rim 326 that interacts with the shoulder separating the 
neck from the reservoir 320 proper. The wringing device 321 consists, in a 
known manner, of a flexible and elastic material. An applicator is 
intended to interact with the reservoir 320. This applicator consists of 
means 323 for holding which supports the applicator member 330, comprising 
a wand 322 and an applicator member 301 which are identical to those 
depicted in FIGS. 1D or 2D. The means 323 for holding is in the form of a 
cap and has a screw thread 323a which interacts with the screw thread 324a 
on the neck of the reservoir. The reservoir 320 can be closed and sealed 
by screwing the means 323 holding onto the neck 324 of the reservoir 
provided with its seal 325. 
When the applicator member 330 is pulled out of the reservoir, the 
applicator member which is in the form of a brush laden with mascara 
passes through the wringing device 321. The latter wrings out the bristles 
on the back of the brush more than it wrings out the bristles in the 
hollow of the brush. The bristles on the sides of the brush are very much 
wrung out. 
While applying the mascara to the eyelashes, the brush coats the lashes 
with product on both faces, then spreads out the product, lengthens and 
curls the lash with its back and hollow faces, and combs using its sides. 
As the bristles on the sides are very long compared with the rest of the 
bristles of the brush and the comb is not very thick, the lashes are 
engaged very well during this combing-out, which is very effective. 
Compared with the brushes known from the prior art that are convex overall, 
the brush according to the invention offers the advantages of being very 
easy to use, of applying make-up to all of the hairs on the eyelid without 
overspill, and of providing a very lengthening and very curling make-up 
effect with good separation.