WO2016202929A1

WO2016202929A1 - Mascara brush

Info

Publication number: WO2016202929A1
Application number: PCT/EP2016/063909
Authority: WO
Inventors: Davide Manici; Eric Caulier
Original assignee: L'oreal
Priority date: 2015-06-19
Filing date: 2016-06-16
Publication date: 2016-12-22
Also published as: FR3037489B1; FR3037489A1

Abstract

The present invention relates to a brush (10) for applying a product (P) to the eyelashes and/or eyebrows, comprising a twisted core (40) and bristles (41) supported by the core, the envelope surface (S) defined by the free ends of the bristles defining at least one helical groove (50) around the longitudinal axis (X) of the core, the longitudinal axis of the core being curved at least along part at least of said groove.

Description

Mascara brush

The present invention relates to brushes for applying a cosmetic product to the eyelashes or eyebrows, in particular a makeup or care product, for example mascara, and to corresponding packaging and application devices.

A very large number of applicators are known in which the brush comprises a core formed by two branches of a metal wire that are twisted together and grip bristles.

Since the bristles used are generally the same length, once the branches are twisted, the brush has an envelope surface in the form of a cylinder of revolution. Such a form has limited effectiveness in terms of loading the eyelashes and separation. Efforts have thus been made to give the envelope surface more complex shapes so as to form on the brush, after wiping, zones that are more heavily laden with product, making it possible to properly load the eyelashes, and zones that are less heavily laden, these being usable to separate the eyelashes. Finding the shape that results in the optimum makeup result requires numerous tests, since many factors come into play.

In addition, it is economically advantageous for the brush to be able to be manufactured easily and quickly.

Lastly, the brush must be simple to use.

Numerous brushes have been proposed, with notches machined in the longitudinal direction of the core. The patent application FR 2 605 505 discloses a brush in which the envelope surfaces of the regions situated between two crests are planar surfaces or surfaces with a concave profile. An envelope surface is thus obtained which, in cross section, has various shapes such as a triangle, a square or a hexagon, with straight or concave sides.

It is known from US 5 595 198 to produce a brush with helical grooves. The latter are produced by firstly machining a blank with two rectilinear and diametrically opposite longitudinal grooves. The core is then twisted about its axis, which transforms the rectilinear grooves into longitudinal grooves.

US 6 279 583 provides a similar teaching.

US 5 551 456 discloses a brush obtained by twisting a blank that has a flattened cross section.

To date, there is still a need to improve brushes for applying a cosmetic product to the eyelashes and/or eyebrows, in particular to benefit from brushes that are capable of satisfactorily making up the eyelashes and eyebrows, by providing a sufficient load of product, and that are easy to use.

The invention aims to meet this need and relates, according to one of its aspects, to a brush for applying a product to the eyelashes and/or eyebrows, comprising a twisted core and bristles supported by the core, the envelope surface defined by the free ends of the bristles defining at least one helical groove around the longitudinal axis of the core, the longitudinal axis of the core being curved at least along part at least of said groove. The brush preferably comprises more than one helical groove, preferably four grooves, and these grooves are preferably equally distributed around the longitudinal axis of the brush. The grooves preferably have a V shape cross section.

By virtue of the invention, a brush is obtained that comprises at least one product storage zone in said groove, for providing a sufficient charge of product, and at least one zone that is loaded with less product, outside said groove, and that can be used for separating the eyelashes and/or eyebrows.

The helical path of the groove ensures gradual loading of the eyelashes.

The fact that the core is curved makes it possible for the wiping to be nonuniform as the brush passes the wiping member and to have zones that are wiped unequally.

The user thus has available, on the brush, zones which are loaded to a greater or lesser extent with product, since they are wiped to different extents, and which can optionally be used depending on the desired result.

Moreover, the curvature of the core can help the user to align the latter at an angle with respect to the row of eyelashes to be made up, which makes the brush easier to use to achieve reproducible making up.

The term "helical" is to be understood as meaning a groove which runs around the longitudinal axis of the core as it proceeds along the latter. It can be a helix with a fixed or variable pitch and/or with a constant or variable radius.

The pitch is preferably fixed if one considers the helix defined by the bottom of the groove.

The radius of the helix is preferably fixed if one considers the same helix. The bottom of the groove can thus be situated at a constant distance from the core, all the way along the groove. The depth of the groove, with respect to the envelope surface outside the groove, can be variable.

A "groove" is to be understood as meaning a hollowed out relief when the brush is observed in cross section.

The longitudinal axis of the brush can be curved along the entire length of the envelope surface. In other words, the entire portion of the core carrying bristles is curved at every point of this portion.

The helical groove can extend along the entire length of the envelope surface, preferably continuously, that is to say it is not interrupted as it proceeds along the longitudinal axis of the core.

The core can be of constant curvature where it is curved.

The longitudinal axis of the core preferably extends in a plane where the core is curved. This plane can intersect an end of the one or more helical grooves, preferably the proximal end thereof.

The helical groove can be obtained by twisting a brush blank around the longitudinal axis of the core, before the core is curved, this blank having a rectilinear groove on its envelope surface, this groove giving rise to said helical groove after curvature.

The invention also relates to an applicator comprising a stem with, at one end, a brush according to the invention.

The invention further relates to a packaging device comprising:

- a container holding a cosmetic product to be applied to the eyelashes and/or eyebrows,

- an applicator according to the invention, as defined above,

The container can be provided with a wiping member for removing the excess product present on the brush.

The invention likewise relates to a method for manufacturing a brush, comprising the steps of:

a) producing a brush blank having a core with a rectilinear longitudinal axis and an envelope surface having at least one helical groove extending along at least part of the envelope surface, b) curving the core at least in a region extending along at least part of the helical groove.

The curving is preferably carried out about an axis of curvature that is perpendicular to the longitudinal axis of the core.

The core can be curved entirely in one plane.

The method according to the invention can comprise the production of at least one rectilinear groove on the blank being formed and the twisting of said blank being formed about its longitudinal axis to transform the rectilinear groove into a helical groove and to arrive at the blank of step a) above.

The core can be curved in an aligned manner at an angle with respect to the helical groove. Thus, all the bushes manufactured according to an illustrative embodiment of the invention are curved in the same way with respect to the helical groove. The curving of the core can thus be carried out in a plane positioned in alignment with respect to the helical groove, in particular with respect to its proximal end. For example, the angular offset between the plane of curvature of the core and the proximal end of the helical groove is 0°. Alternatively, the plane of curvature contains the proximal end of another helical groove.

The invention may be better understood on reading the following detailed description of a non-limiting illustrative embodiment thereof and on examining the appended drawing, in which:

- Figure 1 shows an example of a packaging and application device according to the invention, in schematic longitudinal section,

- Figure 2 is a side view of an example of a brush according to the invention,

- Figure 3 shows a blank used in the manufacture of the brush,

- Figure 4 is a perspective view of the blank, after a first treatment step,

- Figure 5 is a front view along V in Figure 4,

- Figure 6 shows a perspective view of the treated blank from Figure 4, after the core has been twisted, and

- Figure 7 is a front view along VII in Figure 6.

In the rest of the description, identical elements or elements having equivalent functions bear the same reference signs. Their description is not repeated for each of the figures, only the main differences between the embodiments being mentioned. The packaging and application device 1 shown in Figure 1 has a container 2 holding a product P to be applied to the eyelashes or eyebrows and an applicator 3 which, in the example in question, can be fixed removably to the container 2. The product P comprises, for example, one or more pigments, in particular an iron oxide. It is preferably a mascara.

The applicator 3 comprises a stem 5 of longitudinal axis Y, which stem 5 is provided at a distal end 5 a with a brush 10 according to the invention and is provided at the other end with a gripping member 11, which likewise forms a cap for closing the container 2 in a sealed manner. As can be seen in particular in Figure 1, the latter has a body 13 which is provided at the top with a threaded neck 14 onto which the gripping member 11 can be screwed in order to close the container 2. In a variant, the applicator can be fixed to the container in some other way.

As is shown, the neck 14 is able to receive a wiping member 20 which, for example, is attached thereto. This wiping member 20 has a lip 26 defining a wiping orifice with a diameter adapted to that of the stem 5.

The brush 10 can be fixed, in a conventional manner, in a seat provided at the distal end 5a of the stem 5, which is advantageously made of a thermoplastic material.

The brush 10 has a twisted metal core 40 formed by two branches which are twisted together and which between them grip bristles 41.

The core 40 is fixed at one end in the corresponding seat of the stem 5 by a portion of the core that does not have bristles, it being possible for said portion to have a length in the order of 8 mm, for example.

As is illustrated in Figure 2, the free ends of the bristles 41 define an envelope surface S of the brush 10.

The longitudinal axis X of the core 40 of the brush 10 is curved on its part 40c carrying the bristles 41. More particularly, the core 40 is curved along the entire length of this part carrying the bristles 41, which is of constant radius of curvature R and measures for example between 30 and 40 mm, for example of the order of 35 mm. The portion 40a of the core, which serves for fixing in the stem, is rectilinear with an axis Y. In the example illustrated, the distal end 40b of the core 40 is situated on the axis Y, but it could be otherwise situated. The longitudinal axis X of the portion 40c of the core carrying the bristles extends entirely on the same side of a plane M containing the axis Y perpendicular to the plane of Figure 2.

The envelope surface S defines at least one helical groove 50 which extends along the entire length of the portion 40c of the core carrying the bristles and which makes a half turn about the longitudinal axis X of the core between the distal and proximal ends thereof.

In the example in question, the brush 10 comprises four such helical grooves 50 distributed at equal angles around the axis X.

It will be noted from Figure 2 that the proximal end of at least one helical groove 50 is situated substantially in the plane on the side of which the longitudinal axis X of the curved portion 40c of the core extends.

The distal end 50b of the diametrically opposite groove 50 is situated substantially in this same plane.

The bush 10 can be manufactured by proceeding as follows.

Firstly, a brush blank 10^ as shown in Figure 3 is formed by machining a brush with a cylindrical envelope surface of revolution about the longitudinal axis X. This blank 10^ shown in Figure 3 has a biconical overall shape, with a substantially conical distal portion 60 converging towards the distal end 40b of the core, the envelope surface of this portion 60 not being strictly conical but having an outwardly curved convex profile with radius of curvature Rl in the plane of Figure 5, for example greater than or equal to 100 mm, for example of the order of 125 mm.

The blank 10^ has a proximal portion 62 with a substantially conical shape converging towards the proximal end of the brush. In the example in question, this proximal portion is not strictly conical but has an outwardly curved concave profile of radius of curvature R2 in the plane of Figure 3 greater than or equal to 100 mm, for example of the order of 120 mm.

The portions 60 and 62 are connected by an intermediate portion 61 which is shorter than the portions 60 and 62 and which at its top has a radius of curvature R3 of for example between 5 and 10 mm, for example of the order of 8 mm.

The total length L of the portion 40c of the core carrying bristles is for example between 25 and 30 mm, for example of the order of 27 mm. The greatest diameter D of the blank 10^ is, for example, between 8 and 10 mm, for example of the order of 9 mm.

The diameter d of the distal end face of the blank 10^ is, for example, between 4 and 6 mm, for example of the order of 5 mm.

The greatest diameter D is measured at a distance / from the proximal end of the portion 40c of the core, for example of between 10 and 15 mm, for example of the order of 12 mm in the example in question.

Once the blank 10^ has been produced, the grooves 50 are machined in it in the rectilinear state as illustrated in Figures 4 and 5, in order to obtain a blank 10^² visible in Figures 4 and 5. In the example in question, these grooves 50 are four in number and are distributed at equal angles about the axis X of the blank.

Each groove 50 has, in cross section, a V-shaped profile as illustrated in Figure 5, with opposite flanks 51 which between them form an angle a, for example equal to 60°.

The depth of each of the grooves 50 corresponds substantially to the difference D-d and, as can be seen in Figure 5, can be slightly greater than D-d.

Once the grooves 50 have been produced in order to obtain the blank 10^² the portion 40c of the core is twisted about its axis X, which deforms the whole brush and in particular the grooves 50, which assume a helical configuration as shown in Figures 6 and 7.

In the example in question, this twisting entails a half turn between the proximal end and the distal end of the core portion 40c. The blank 10^ is obtained.

Finally, according to the invention, the core is curved along at least part of its length on the portion 40c in order to obtain the brush 10 shown in Figure 2. The curvature takes place in a plane which corresponds to the plane of Figure 2 and which is designated C in Figure 5, this plane intersecting two diametrically opposite grooves 50 by passing through the bottom of these grooves. It is thereby ensured that the end of one of the grooves is included in this plane and also the end of the other diametrically opposite groove, taking into consideration the 180° twisting imparted to the blank 10^²

The curvature of the core allows the user to more easily position the reservoirs of product, which are constituted by the helical grooves 50, with respect to the eye. The radius of curvature R of the axis X of the core can generally be between 30 mm and 200 mm.

The invention is not limited to the illustrative embodiment that has just been described.

The number of helical grooves 50 is not limited to four and may be lower, for example two or three helical grooves, or higher.

The pitch of the helical grooves 50 can be adjusted in such a way that each helical groove extends, for example, between a quarter of a turn along the entire length of the core portion 40c carrying the bristles, up to 3 complete turns.

The profile of the grooves 50 can be other than V-shaped and can, for example, have a rectangular shape, a semicircular shape or another shape.

At the bottom of the groove 50, the width w is 0.4 mm for example, while at the top of the groove, measured between the two opposite flanks 51 thereof, it is 4.5 mm for example.

The distance between the bottom of a groove and the longitudinal axis X of the core is, for example, between 2 and 7 mm, the latter value preferably being that of a brush whose greatest diameter D is equal to 12 mm.

The shape of the blanks 10^ or 10^ produced before the curvature of the core can be obtained by cutting out the bristles with the aid of a milling device or by laser or by any other suitable technique.

A helical groove 50 can have a constant cross section along the core or, alternatively, a cross section that changes along the core; for example, the depth of the helical groove can vary along the core, or its shape can vary.

The expression "comprising a" should be understood as being synonymous with "comprising at least one".

Claims

1. Brush (10) for applying a product (P) to the eyelashes and/or eyebrows, comprising a twisted core (40) and bristles (41) supported by the core, the envelope surface (S) defined by the free ends of the bristles defining at least one helical groove (50) extending around the longitudinal axis (X) of the core, the longitudinal axis of the core being curved at least along part at least of said groove.

2. Brush according to Claim 1, comprising a plurality of said helical grooves, preferably 4 grooves.

3. Brush according to Claim 2, the grooves being equally distributed around the longitudinal axis of the

4. Brush according to anyone of the preceeding Claim, the grooves having a V shape in cross section.

5. Brush according to anyone of Claim 1 to 4, the longitudinal axis (X) of the brush being curved along the entire length of the envelope surface (S).

6. Brush according to anyone of Claim 1 or 5, the helical groove (50) extending along the entire length of the envelope surface.

7. Brush according to any one of the preceding claims, the core (40) being of constant curvature where it is curved.

8. Brush according to any one of the preceding claims, the longitudinal axis

(X) of the core extending entirely in the same plane (C) where the core is curved.

9. Brush according to Claim 8, said plane (C) intersecting the proximal end of the helical groove.

10. Brush according to any one of the preceding claims, the groove (50) extending around a quarter of a turn to 3 turns, preferably a half turn.

11. Applicator comprising a stem (5) with, at one end, a brush (10) as defined in any one of the preceding claims.

12. Packaging and application device (1), comprising:

- a container holding a cosmetic product (P) to be applied to the eyelashes and/or eyebrows,

- an applicator as defined in claim 11.

13. Method for manufacturing a brush according to any one of Claims 1 to 10, comprising the steps of:

- a) producing a brush blank 10^ having a core with a rectilinear longitudinal axis (X) and an envelope surface (S) having at least one helical groove (50) extending along at least part of the envelope surface,

- b) curving the core at least in a region extending along at least part of the helical groove.

14. Method according to the preceding claim, comprising the production of at least one rectilinear groove (50) on the blank being formed 10^ and the twisting of said blank being formed about its longitudinal axis to transform the rectilinear groove into a helical groove.

15. Method according to either of Claims 13 and 14, the core being curved in an aligned manner at an angle with respect to the helical groove (50).

16. Method according to Claim 15, the curving of the core being carried out in a plane (C) positioned in alignment with respect to the helical groove (50), in particular with respect to its proximal end (50a), in particular in a plane containing the proximal end (50a) or containing the proximal end of another helical groove.