EP2923601B1 - Applicator for a cosmetic product, in particular mascara and method of producing such an applicator - Google Patents

Description

The invention relates to an applicator for a cosmetic product, in particular mascara. The invention further relates to a method for the manufacture of such an applicator.

The applicators for mascara can be injection molded of plastic, they are then commonly called "plastic brushes". They can also be obtained from fibrous elements held between the longitudinal portions of a twisted metal pin; they are then commonly called "fiber brushes". The applicators for mascara have a core, or central portion, and spikes extending radially around said core. The ends of said spikes usually form envelopes in a direction of longitudinal extension of said brush. The spikes of twisted brushes are commonly called "fibers"

The document FR2811525 discloses a device for applying a product to keratinous fibers, in particular eyelashes or eyebrows, comprising a tail, of X axis, one end of which connects to an application portion, suitable for applying the product to said fibers, said application portion comprising at least two faces each delimited by two longitudinal edges, and extending over at least a part of the length of the application portion, at least a first face forming with the X axis a non-zero angle α whose vertex is turned away from the vertex of a non-zero angle β formed by at least one second face with said axis X.

The document US6237609 discloses a mascara brush having a curved core.

The document US20080184512 discloses an applicator for applying a product to the eyelashes or eyebrows, comprising a brush having bristles, a core having a straight portion from which the bristles extend, the bristles having free ends which define an envelope surface, the bristle envelope surface extending along a longitudinal axis not parallel to the longitudinal axis of the rectilinear portion of the core and having at least one cross section of flattened shape along a median plane, the envelope surface defining at least one face parallel to the longitudinal axis of the soul.

The document US20020124860 shows a brush for applying a product to the keratinous fibers, in particular for applying mascara to the eyelashes, characterized in that it has a variable cross section and in that its curvature is non-constant.

It is in particular known twisted brushes to promote the curvature of the eyelashes. They include a curved core according to the desired curvature.

The invention proposes to make a twisted brush allowing such an effect makeup while adding a complementary effect.

Thus, the invention relates to an applicator for a cosmetic product, in particular for mascara, comprising a twisted core and fibers which extend from the core while being held by said core, said core having a principal longitudinal extension direction , said main axis, said core being rectilinear along said main axis, said fibers forming an envelope with their free end, said envelope comprising, along said main axis, a substantially concave face and a substantially convex opposite face, said envelope comprising in addition at least two substantially convex faces, opposite and substantially symmetrical with respect to a plane comprising said main axis, a section of said envelope made transversely to the main axis, said cross section, having a polygonal shape along said main axis.

The applicator of the invention thus proposes a particular arrangement of fibers which improves the curvature of the eyelashes of the user of such an applicator, while allowing them to be optimally loaded.

Indeed, the concave face of said applicator makes it possible to curve the eyelashes. Such a concave face is usually obtained from fibers that have the same radial extension from a curved core. Here, the concave face is obtained from fibers having different radial extensions from a core, the latter being rectilinear in contrast to the curved cores of the prior art. Thus, the applicator of the invention has the advantage of charging the eyelashes of the user optimally because its concave face has fibers of small radial extensions which have a high charging power.

The particular arrangement of the fibers of the applicator of the invention also allows the combing of the eyelashes, curved and loaded by the concave face; indeed, said applicator has a convex face, also formed from fibers having different radial extensions from the straight core. It is said convex face that gives this painting power to the applicator of the invention.

In other words, the fibers defining said concave and convex faces of the envelope extend radially asymmetrically with respect to the core.

The use of a twisted brush allows, in addition, a greater density of fibers than with the pins of the plastic brushes.

• lesdites faces présentent chacune un plan de symétrie comprenant l'axe principal,
• lesdites faces sont chacune générée par une droite, dite droite génératrice, orthogonale à l'axe principal et orthogonale au plan de symétrie de ladite face,
• la forme de la section transversale de l'enveloppe est un quadrilatère, notamment un rectangle, voire un carré,
• ladite enveloppe comporte quatre faces dont trois convexes,
• l'âme présente une extrémité distale et une extrémité proximale, l'extrémité proximale étant opposée à l'extrémité distale le long de l'axe principal,
• lesdites fibres sont réparties le long de l'âme, sur une partie substantielle de sa longueur à partir de l'extrémité distale,
• ladite âme est constituée d'une tige torsadée,
• ladite extrémité proximale de l'âme est prolongée par une portion de la tige dépourvue de fibres,
• ladite enveloppe présente des chanfreins au niveau d'au moins une de ses faces, à l'extrémité distale de ladite âme,
• l'applicateur forme une brosse.

According to various embodiments of the invention, which may be taken together or separately:

• said faces each have a plane of symmetry comprising the main axis,
• said faces are each generated by a straight line, said generator line, orthogonal to the main axis and orthogonal to the plane of symmetry of said face,
• the shape of the cross section of the envelope is a quadrilateral, in particular a rectangle, or even a square,
• said envelope has four faces including three convex,
• the core has a distal end and a proximal end, the proximal end being opposite to the distal end along the major axis,
• said fibers are distributed along the core, over a substantial part of its length from the distal end,
• said core consists of a twisted rod,
• said proximal end of the core is extended by a portion of the fiber-free stem,
• said casing has chamfers at at least one of its faces, at the distal end of said web,
• the applicator forms a brush.

The invention also relates to a process for the manufacture of an applicator for a cosmetic product, in particular mascara, said process comprising:
a step of positioning a plurality of fibers between longitudinal portions of a spindle, and then a first step of twisting said spindle to form a twisted spindle having fibers extending radially around it, the ends of said fibers forming a cylindrical envelope extending in a direction of longitudinal extension around said pin, said main axis, then a step of cutting the fibers, so that said fibers form an envelope with their free end, said envelope comprising, along said main axis, a substantially concave face and a substantially convex opposite face, said envelope further comprising at least two substantially convex faces, opposite and substantially symmetrical with respect to a plane comprising said main axis, a section of said envelope made transverse to the main axis, said cross-section, having a polygonal shape ong of said main axis, the pin being kept rectilinear.

• ledit procédé comprend une seconde étape de torsion de ladite broche après ladite étape de découpe des fibres,
• ladite découpe est à commande numérique.

According to various embodiments of the invention, which can be taken together or separately:

• said method comprises a second step of twisting said pin after said step of cutting fibers,
• said cutout is numerically controlled.

The invention also relates to an assembly comprising an applicator as described above and a receptacle for a cosmetic product, in particular mascara, capable of containing such an applicator.

The invention will be better understood, and other objects, details, features and advantages thereof will become more clearly apparent in the following detailed explanatory description of at least one embodiment of the invention given to As a purely illustrative and non-limiting example, with reference to the accompanying schematic drawings.

• la figure 1 est une vue de face d'un exemple de réalisation d'un applicateur selon l'invention,
• la figure 2 représente l'applicateur de la figure 1 après que celui-ci ait été tourné d'un quart de tour autour de son axe longitudinal.

On these drawings:

• the figure 1 is a front view of an exemplary embodiment of an applicator according to the invention,
• the figure 2 represents the applicator of the figure 1 after it has been turned a quarter turn around its longitudinal axis.

The invention relates to an applicator 10 for a cosmetic product, in particular mascara, comprising a twisted core 12 and fibers which extend from the core 12 while being held by said core 12.

The core 12 is here formed by a metal rod, or pin, having two branches, or longitudinal portions, optionally interconnected by a curved portion. Said metal rod is, for example, folded in two so as to form a "U", the branches of the U is then twisted together.

The fibers extend from the core 12 between a distal end 16 and a proximal end 14 of the core 12. The fibers each have a free end and form an envelope E with. The Figures 1 and 2 illustrate in particular an embodiment of envelope E according to the invention. Envelope printing will of course be more or less present depending on the density of the fibers.

The applicator 10 extends in a principal direction of longitudinal extension, or main axis, which is marked X on the Figures 1 and 2 . This axis X is also the axis of the soul 12. The soul 12 will be straight.

Thus, the fibers extend transversely to the X axis, in particular radially, from the core 12, to form the envelope E with their free end, between the distal end 16 and the proximal end 14 of the core 12. These ends 14, 16 are opposite to the axis X and are spaced along said axis X by a distance marked H on the figure 1 . Said distance H is, for example, between 22mm and 30mm, and substantially equal, for example, to 26mm or 27mm. he It should be noted that the proximal end 14 is here extended by a portion 13 of the rod 12 without fibers.

As illustrated on the Figures 1 and 2 , the envelope E has curved faces F1-F4 having a slope, or variable inclination, of said distal end 16 at said proximal end 14.

According to the invention, said envelope E comprises, along said main axis X, a substantially concave face F1 and a substantially convex face F3, opposite.

The concave face is marked F1 on the figure 1 . This concave face F1 has an extremum in the vicinity of an intermediate line 15 located between the distal end 16 and proximal ends 14. Said intermediate line 15 belongs to a plane substantially orthogonal to the X axis which comprises an intermediate point of the X axis , said point being advantageously equidistant from said ends 14, 16. The distance h15 separating the proximal end 14 of this intermediate line 15, along said axis X, is substantially equal, for example, to 13 mm. This intermediate line 15 is an imaginary line which follows the periphery of the envelope E.

On the figure 1 the convex face, opposite the concave face F1, is marked F3. This convex face F3 has an extremum, for example in the vicinity of the intermediate line 15. By opposite face is meant the face F3 which is opposite to the concave face F1 with respect to the core 12. In other words, the opposite faces F1, F3 are not in contact.

The figure 2 illustrates the applicator 10 when viewed from the side with respect to the figure 1 . There can be observed the shape of two faces F2, F4 which are the faces connecting said two faces F1, F3 concave and convex which have just been described. These faces F2, F4 will be called bonding faces thereafter.

In the embodiment shown here, these two connecting faces F2, F4 are substantially convex. Said two connecting faces F2, F4 have, in particular, an extremum in the vicinity of the intermediate line 15.

It should be noted that figure 1 illustrates the face F2 by its contours, in a plane (that of the sheet); however, the curvature in the space of said face F2 is visible on the figure 2 where she is represented in profile.

Similarly, the concave face F1, illustrated on the figure 2 by its outlines, presents a curvature in space that is particularly visible on the figure 1 .

The envelope E which has just been described has two pairs of faces F1, F3 and F2, F4. One of the pairs of faces comprises faces F2, F4 symmetrical with respect to a median plane comprising the core 12; these are the so-called connecting faces F2, F4. The faces F1, F3 of the other pair follow substantially the same curve along the main axis X (see figure 1 ).

It should be noted that this embodiment is not limiting and the applicator 10 may have three or even four or six pairs of symmetrical faces in pairs, this without departing from the scope of the invention, the moment that it comprises a pair of faces, one of which is substantially concave F1 and the other substantially convex F3.

It should be noted that said F1-F4 faces are advantageously generated by a straight line, said generator line, orthogonal to the core 12 and orthogonal to the plane of symmetry of each of said F1-F4 faces. Thus, the envelope has a cross section in a plane substantially orthogonal to said axis X, whose shape is a polygon, all along said core 12, from said distal end 16 to said proximal end 14, said shape being in particular a quadrilateral , or even a rectangle, in particular at the intermediate line 15.

The concave face F1 thus obtained, while the core 12 is advantageously rectilinear, provides a better effect than that obtained with the twisted brushes usually used to bend eyelashes. Indeed, when a user seeks to curl his eyelashes optimally, it is advisable to focus on mascaras that have the particular property of quickly drying in the open, this in order to quickly freeze the curved shape of eyelashes so drawn.

Twisted brushes having a curved core having fibers of the same radial extension all along said curved core, when they are used with a cosmetic product which dries rapidly, have the disadvantage of poorly, even failing to return said product to the lashes. Thus, these twisted brushes curved core can not be used optimally.

In contrast, the applicator according to the invention - thanks to its concave face F1 formed using fibers which do not have the same radial extension from the core 12, along the main axis X, which is itself substantially rectilinear - allows the use of said applicator with cosmetics which have the particular property of drying quickly in the open air. The makeup effect obtained with the applicator of the invention is then optimized, namely it allows to curve the eyelashes while loading them with a cosmetic product that is particularly suitable for this application.

The F1-F4 faces are further advantageously delimited by disjointed lateral edges. In other words, the F1-F4 faces are delimited by edges - the lateral edges - which are curves set in a three-dimensional orthonormal Cartesian coordinate system, one of said dimensions being coincident with the direction of said axis X, the coordinates of said curves. parametrized moving in the three directions of said Cartesian coordinate system and said parametric curves not being merged at any point between said distal end 16 and proximal ends 14.

Said edges therefore have a complex layout although obtained with faces that remain easy to achieve. This pattern is particularly advantageous for hanging eyelashes and lengthen them.

To facilitate the return of the brush 10 in its receptacle, the envelope of the applicator 10 may have chamfers 20 at some of its faces, at the distal end 16 of the core 12. In fact, the Distal end 16 is usually the one through which contact with the receptacle is made when the user tidies the applicator 10 after use. Preferably, the envelope comprises at least one face with a chamfer 20, namely the substantially concave face F1. The height of this chamfer 20 will be less than or equal to 5mm.

It is interesting to note that the width of the envelope E is functionally related to the advantages of the applicator 10; said width varies along the X axis, between extremes, said extremes being marked dmax , dmin on the Figures 1 and 2 . dmax , dmin correspond, moreover, to the bulk of the envelope E, in particular to at least one of the dimensions of the cross section of the envelope E, said cross section being made at different points of the main axis X.

Thus, the following formula will be advantageously respected: $$\mathrm{0,125}\le \raisebox{1ex}{$\mathit{dmin}$}\!\left/ \!\raisebox{-1ex}{$\mathit{dmax}$}\right.\le \mathrm{0.625.}$$

For example, dmax will be between 6 and 8mm and dmin will be between 3 and 4.5mm.

The invention also relates to a process for the manufacture of an applicator for a cosmetic product, in particular mascara, for example that which has just been described.

This method first comprises a step of positioning a plurality of fibers between longitudinal portions of a spindle (not shown). The fibers are distributed in such a way that said longitudinal portions pass substantially in the middle of each of said fibers.

The next step of said method is a first step of twisting said pin to form a twisted pin having fibers extending radially around it. The ends of said fibers then form a cylindrical envelope extending in a direction of longitudinal extension around said pin. The fibers are distributed as fiber turns because of the twisting of the spindle.

The following step is a step of cutting the fibers, so that said fibers form an envelope E with their free end, said envelope E comprising, along said main axis, a substantially concave face F1 and a face F3 substantially convex, opposite, forming in particular an envelope E such as that described above. Said cutting may be numerically controlled. During all these operations, the twisted spindle is kept rectilinear.

Advantageously, the portion of the fiber-free spindle which extends the proximal end 14 will be intended to be fixed inside a hollow rod, itself linked to a handle by which the user will manipulate said applicator. Said portion is twisted or not.

It should be noted that the applicator of the invention advantageously forms a brush.

It should also be noted that variant embodiments are of course possible. In particular, it is also conceivable, in an embodiment not illustrated here, to provide the envelope E in a helical form. In other words, the edges of the faces described above can follow a helix from the proximal end 14 to the distal end 16 of the applicator 10, for example by a second step of twisting the method according to the invention. The concave face is then a left surface.

Claims (7)

1. Applicator (10) for cosmetic product, in particular mascara, comprising a twisted core (12) and fibres that extend from the core (12) by being maintained by said core (12), said core (12) having a main longitudinal extension direction, referred to as the main axis (X), said core (12) being straight along said main axis (X), said fibres forming an envelope (E) with the free end thereof, said envelope (E) comprising, along said main axis (X), a substantially concave face(F1) and a substantially convex face (F3), opposite, said envelope (E) further comprising at least two substantially convex faces (F2, F4), opposite and substantially symmetrical with respect to a plane comprising said main axis (X), a section of said envelope (E) produced transversally to the main axis (X), referred to as the transversal section, having a polygonal shape along said main axis (X).
2. Applicator (10) according to the preceding claim, wherein said faces (F1, F3) each have a plane of symmetry comprising the main axis (X).
3. Applicator (10) according to any one of claims 1 or 2, wherein said faces (F1, F3) are each generated by a line, referred to as the generator line, orthogonal to the main axis (X) and orthogonal to the plane of symmetry of said face (F1, F3).
4. Applicator (10) according to claim 1, wherein the shape of said cross section is a quadrilateral.
5. Applicator (10) according to any one of the preceding claims, wherein said envelope (E) comprises four faces (F1-F4) of which three are convex (F2-F4).
6. Method for manufacturing an applicator (10) for cosmetic product, in particular mascara, said method comprising:

   - a step of positioning a plurality of fibres between longitudinal portions of a pin, then

   - a first step of twisting of said pin to form a twisted pin having fibres extending radially around it, the ends of said fibres forming a cylindrical envelope extending in a longitudinal extension direction about said pin, referred to as the main axis (X), then

   - a step of cutting fibres, such that said fibres form an envelope (E) with the free end thereof, said envelope (E) comprising, along said main axis (X), a substantially concave face(F1) and a substantially convex face (F3), opposite, said envelope (E) further comprising at least two substantially convex faces (F2, F4), opposite and substantially symmetrical with respect to a plane comprising said main axis (X), a section of said envelope (E) produced transversally to the main axis (X), referred to as transversal section, having a polygonal shape along said main axis (X), the pin being kept straight.
7. Assembly comprising:

   - a receptacle for cosmetic product, in particular mascara, capable of containing an applicator (10) according to any one of claims 1 to 5, and

   - an applicator (10) according to any one of claims 1 to 5.

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