Login| Sign Up| Help| Contact|

Patent Searching and Data


Title:
BRUSH FOR APPLYING A PRODUCT TO THE EYELASHES OR EYEBROWS
Document Type and Number:
WIPO Patent Application WO/2018/114851
Kind Code:
A1
Abstract:
The present invention relates to a brush (10) for applying a product to the eyelashes and/or eyebrows, comprising: - a core (40), notably a twisted core, that extends along a longitudinal axis (X), and - bristles that are held by the core (40) in a portion of the core bearing the bristles, the bristles having free ends that define an envelope surface (S), the envelope surface (S) being configured in such a way that, over at least part of the portion of the core that bears the bristles, when progressing about the longitudinal axis (X) of the core (40), at least one convex portion (50, 52; 55, 57) and at least one concave portion (51; 56) that, where they meet, form a point of inflection (54; 54'), are encountered in succession in cross section in a plane perpendicular to the longitudinal axis (X) of the core, notably over a predefined angular range (α; α') of 180°.

Inventors:
SCHREIBER, Camille (L'OREAL Campus Charles Zviak 9, rue Pierre Dreyfus, CLICHY, 92110, FR)
BERHAULT, Alain (L'OREAL Campus Charles Zviak 9, rue Pierre Dreyfus, CLICHY, 92110, FR)
Application Number:
EP2017/083388
Publication Date:
June 28, 2018
Filing Date:
December 18, 2017
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
L'OREAL (14 Rue Royale, PARIS, 75008, FR)
International Classes:
A46B3/18; A45D34/04; A46B1/00; A46B9/02
Attorney, Agent or Firm:
CABINET NONY (11 rue Saint-Georges, PARIS, 75009, FR)
Download PDF:
Claims:
CLAIMS

1. A brush (10) for applying a product to the eyelashes and/or eyebrows, comprising:

- a core (40), notably a twisted core, that extends along a longitudinal axis (X), and

- bristles (41) that are held by the core (40) in a portion (43) of the core bearing the bristles, the bristles (41) having free ends that define an envelope surface (S),

the envelope surface (S) being configured in such a way that, over at least part of the portion (43) of the core that bears the bristles, when progressing about the longitudinal axis (X) of the core (40), at least one convex portion (50, 52; 55, 57) and at least one concave portion (51; 56) that, where they meet, form a point of inflection (54; 54'), are encountered in succession in cross section in a plane perpendicular to the longitudinal axis (X) of the core, notably over a predefined angular range (a; a') of 180°,

in which brush, over said at least one part of the portion (43) of the core bearing the bristles, the envelope surface (S) exhibits symmetry about a midplane (M) extending along the longitudinal axis (X), and in which a cross section of the brush exhibits at least one lash-catching edge corner (53, 58) formed by the vertex of a sharp-angled corner that is salient in cross section.

2. The brush as claimed in claim 1, characterized in that the envelope surface

(S) exhibits, over said angular range (a; a') of 180°, a portion in the overall shape of an S when viewed in cross section.

3. The brush as claimed in one of the preceding claims, in which said at least one convex portion (50, 52; 55, 57) extends over an angular extent (β) in excess of 10°, even in excess of 20°, or even of 30°.

4. The brush as claimed in any one of the preceding claims, said convex and concave portions extending along the entire length (L) of the portion (43) of the core bearing the bristles.

5. The brush as claimed in any one of the preceding claims, in which the envelope surface (S) exhibits, on said at least one part of the portion (43) of the core bearing the bristles, the overall shape of a fish when viewed in cross section.

6. The brush as claimed in any one of the preceding claims, the envelope surface (S) comprising a single concave portion (51; 56) over said angular range (a; a') of 180°.

7. The brush as claimed in any one of the preceding claims, the envelope surface (S) comprising two convex portions (50, 52; 55, 57) over said angular range (a; a') of 180°.

8. The brush as claimed in any one of the preceding claims, the radius of curvature of the or each convex portion being comprised between 0.4 mm and 5 mm, and the radius of curvature of the or each concave portion being comprised between 0.4 mm and 5 mm.

9. The brush as claimed in any one of the preceding claims, in which said predefined angular range (a; a') of 180° extends between two points on the contour that define a largest-dimension diameter of a cross section of the brush.

10. The brush as claimed in any one of the preceding claims, in which at least one convex portion (50; 55) coincides at least partially with a portion of the circle (C) inside which a cross section of the brush can be inscribed.

11. The brush as claimed in any one of the preceding claims, in which the catching edge (53, 58) belongs to the circle (C) inside which the cross section of the brush is inscribed.

12. A packaging and application device (1) comprising:

- a container (2) containing a cosmetic product (P) to be applied to the eyelashes or eyebrows,

- a brush (10) as claimed in any one of the preceding claims.

13. A method for manufacturing a brush (10) as claimed in any one of claims 1 to 11, comprising the steps of:

a. producing a twisted-core brush blank, with rectilinear longitudinal axis (X), notably having a cross section of cylindrical shape over at least part of the portion (43) of core bearing the bristles,

b. cutting the bristles in such a way as to form the convex and concave portions over all or part of the length (L) of the portion of core bearing the bristles, in order to obtain the brush (10).

Description:
BRUSH FOR APPLYING A PRODUCT TO THE EYELASHES OR EYEBROWS Field of the invention

The present invention relates to brushes for applying a cosmetic product to the eyelashes or eyebrows, notably a makeup or care product, for example mascara, and to packaging and application devices comprising such a brush.

Prior art and objectives of the invention

A large number of applicators, in which the brush comprises a core formed by two arms of a metal wire that are twisted together and grip bristles, are known. Since the bristles used are generally the same length, once the arms are twisted, the brush has an envelope surface in the form of a cylinder of revolution. Such a cylinder of revolution shape has limited effectiveness in terms of loading the eyelashes with product and in terms of 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 or are laden little, these being usable to separate the eyelashes. Finding the shape that results in the optimum makeup result requires numerous tests, since there are a large number of factors involved.

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

FR 2 605 505 describes a mascara brush comprising facets forming edge corners between them.

FR 2 755 593 relates to a brush of which the core describes a curve in a plane of curvature and the envelope surface of the brush exhibits, over at least a large proportion of its length, a cross section of elongate shape along an axis of greatest length parallel to the plane of curvature.

FR 2 916 950 describes an applicator for applying a product to the eyelashes and/or eyebrows, comprising an application element having an envelope surface exhibiting a first and a second cross section which are substantially polygonal, at least one first vertex of the first cross section being connected to at least one second vertex and to a third vertex of the second cross section by respective edge corners, with the second and third vertices being angularly offset about the longitudinal axis of the application element. FR 3 019 016 proposes an applicator of the brush type, the envelope surface of which comprises curved faces which alternate about the main axis, a cross section exhibiting a substantially polygonal shape with edge corners between the curved faces.

FR 2 991 560 discloses an applicator having a brush comprising a core and bristles that are retained in a portion of the core. Each bristle has a free end, and free ends of the bristles define an envelope surface of general flattened form according to a flatness plane. The envelope surface defines two opposed principal faces. Each principal face presents a longitudinal notch extending on half of the length of the portion of the core carrying the bristles. An edge and the notches are not parallel to a longitudinal axis of the core.

FR 2 932 657 concerns an applicator having a stem and a brush at the end of this stem, the brush being at least 30 % wider than it is thick in cross section.

FR 2 980 677 relates to a brush having a core extending along a longitudinal axis, wherein the core includes two branches of a wire folded onto itself and twisted together to define turns. Bristles are held between the turns of the core, and a tip defining a distal end of the applicator is crossed by the wire of the core. The tip includes a passage in which the wire of the core penetrates, where the wire of the core is engaged with force through the tip, and the tip is moulded on the wire of the core.

EP 2 229 839 discloses an applicator having a brush fixed on a distal portion of a stem and including a core carrying bristles. The core extends along a curved longitudinal axis completely contained in a plane and includes different concave curvatures towards opposite sides. The axis traverses a rectilinear longitudinal axis of the stem.

There is a need to make it easier to apply makeup along the upper and lower rows of the eyelashes.

There is also a need to improve brushes, notably to benefit from brushes that are capable of satisfactorily making up the eyelashes or eyebrows, by providing a sufficient load of product and satisfactory combing.

Brush

The present invention, according to one of its aspects, relates to a brush for applying a product to the eyelashes and/or eyebrows, comprising:

- a core, notably a twisted core, that extends along a longitudinal axis, and

- bristles that are held by the core in a portion of the core bearing the bristles, the bristles having free ends that define an envelope surface, the envelope surface being configured in such a way that, over at least part of the portion of the core that bears the bristles, when progressing about the longitudinal axis of the core, at least one convex portion and at least one concave portion that, where they meet, define a point of inflection, are encountered in succession in cross section in a plane perpendicular to the longitudinal axis of the core, notably over a predefined angular range of 180°.

Within the meaning of the invention, a "convex portion" and a "concave portion" are understood to be a "portion that is convex toward the outside" and a "portion that is concave toward the outside", respectively, that is to say as seen by an observer looking at the brush in the plane of section.

The convexity of the convex portion of the envelope surface means that the envelope surface in this convex portion lies below its tangents at every point on the convex portion.

The concavity of the concave portion of the envelope surface means that the envelope surface in this concave portion lies above its tangents at every point on the concave portion.

According to the invention, the convex and concave portions where they meet form a point of inflection, namely a point at which the envelope surface crosses its unique tangent at this point. This point of inflection is the limit, the boundary between these convex and concave portions which are contiguous with one another. There is therefore an inversion of the direction of curvature to pass from the convex portion to the concave portion and vice versa. The point of inflection creates an imperceptible or barely perceptible boundary without forming a pronounced longitudinal edge corner between the convex and concave portions.

The convex and concave portions may promote the application and the transfer of the product, notably mascara, onto the eyelashes or eyebrows. By virtue of the invention, a brush is available that offers a reserve of product, in the concave portion, and a combing zone, less heavily laden with product, in the convex portion.

The convex portion forms, on said at least one part of the portion of the core bearing the bristles, a projecting relief. The concave portion forms, on said at least one part of the portion of the core bearing the bristles, a recessed relief. The envelope surface may thus exhibit an alternation of projecting and recessed reliefs. The boundary between projecting relief and recessed relief may be barely perceptible or even imperceptible, being generated merely by an inversion in the direction of curvature at the point of inflection, as described above, or alternatively may be more pronounced in the form of an edge corner. One and the same brush may comprise several boundaries between a convex portion forming a projecting relief and a concave portion forming a recessed relief. Of these, some boundaries may be barely perceptible or imperceptible, being formed by points of inflection, while others on the other hand may be formed by clearly visible edge corners.

Unlike the point of inflection, the or each edge corner forms the vertex of an acute angle, where the envelope surface has two very distinct tangents one on each side thereof.

The envelope surface may exhibit, notably over said angular range of 180°, a portion in the overall shape of an S when viewed in cross section.

What is meant in the invention by "cross section" is a "cross section perpendicular to the longitudinal axis of the core", in a plane of section.

At least one cross section may exhibit symmetry about a diametrical plane. In said at least one part of the portion of the core bearing the bristles, the envelope surface may exhibit symmetry about a midplane extending along the longitudinal axis. Such symmetry may allow the brush to be used indifferently left-handed or right- handed, or over an angular range chosen by the user.

Said at least one convex portion may extend over an angular extent in excess of 10°, notably in excess of 20°, or even of 30°.

Said convex and concave portions may extend along the entire length L of the portion of the core bearing the bristles. As an alternative, only a part of this portion, for example at least 50% of the length thereof, better still at least 60%, or even at least 70% comprises the convex and concave portions. The convex and concave portions may extend along less than 95% of the length L of the portion of the core bearing the bristles, or even along less than 90%>, or even along less than 80%>.

The convex or concave portions may extend as far as the proximal end of the portion of the core bearing the bristles.

The envelope surface may exhibit, on said at least one part of the portion of the core bearing the bristles, the overall shape of a fish when viewed in cross section. In that case, the brush may exhibit symmetry about the midplane. In that case also, there may be, separating the various convex and concave portions that follow on from one another around the entire periphery of the envelope surface of the brush, two points of inflection forming imperceptible or barely perceptible boundaries, at the body of the fish, and two edge corners at the tail of the fish.

The envelope surface may comprise a single concave portion over said angular range of 180°.

The envelope surface may comprise two convex portions over said angular range of 180°. In this case, they may be separated from one another by a concave portion.

The radius of curvature of the or each convex portion may be comprised between 0.4 mm and 5 mm, preferably 2 mm. The radius of curvature of the or each concave portion may be comprised between 0.4 mm and 5 mm, preferably 2 mm. The radius of curvature is measured in the plane of section.

Said predefined angular range of 180° may extend between two points on the contour that define a largest-dimension diameter of a cross section of the brush.

The envelope surface of the brush may be inscribed inside a cylinder of revolution.

At least one convex portion may coincide with a portion of the circle inside which the cross section of the brush can be inscribed.

The brush may exhibit at least one edge corner referred to as the lash-catching edge corner. This edge corner may be defined by the boundary between a convex portion and a concave portion of the envelope surface. The edge corner may be formed by the vertex of a salient corner. The catching edge corner may belong to the circle inside which the cross section of the brush can be inscribed.

The envelope surface may comprise a frustoconical or ogee-shaped distal portion with a cross section that becomes smaller toward the free end of the core. The frustoconical or ogee-shaped distal portion may extend over a length greater than one quarter of the length L of the portion of the core bearing the bristles, better still more than one third of the length of the portion of the core bearing the bristles, and even better still more than half of the length L of the portion of the core bearing the bristles.

The brush may be chamfered at its proximal and/or distal ends. In one exemplary embodiment, the brush is chamfered at its distal and proximal ends.

The core of the brush may be rectilinear or curved. Preferably, it is rectilinear. The core may have a proximal end fixed to the stem of the applicator, and a distal end. The latter may be situated on the longitudinal axis of the stem to which the core is attached. At its opposite end from the brush, the stem may be fastened to a cap for closing a container.

Preferably, the core is a twisted core. The expression "twisted core" should be understood as meaning a core formed by twisting together two arms of a metal wire, in a conventional manner, the bristles being clamped between the arms.

According to another of its aspects, independently of or in combination with all or part of the above, the invention further relates to a brush for applying a product to the eyelashes and/or eyebrows, comprising:

- a core, notably a twisted core, that extends along a longitudinal axis, and

- bristles that are held by the core in a portion of the core bearing the bristles, the bristles having free ends that define an envelope surface,

the envelope surface being configured in such a way that, over at least part of the portion of the core that bears the bristles, when progressing about the longitudinal axis of the core, at least one convex portion and at least one concave portion are encountered in succession in cross section in a plane perpendicular to the longitudinal axis of the core, notably over a predefined angular range of 180°, said at least one convex portion extending over an angular extent in excess of 10°, notably in excess of 20°, or even of 30°.

Device

According to another of its aspects, in combination with the above, the invention further relates to a packaging and application device comprising:

- a container containing a cosmetic product to be applied to the eyelashes or eyebrows,

- a brush as defined above.

The container may be provided with a wiping member for removing the excess product present on the stem and on the brush. This wiping member comprises, for example, a lip made of an elastomer material, defining a wiping orifice which preferably has a circular cross section, the diameter of which corresponds substantially to that of the stem. Method for manufacturing a brush

According to another of its aspects, in combination with the above, the present invention further relates to a method for manufacturing a brush as defined above, comprising the steps of:

a. producing a twisted-core brush blank, with rectilinear longitudinal axis, notably having an envelope surface with a cylindrical shape, preferably a shape exhibiting symmetry of revolution, over at least part of the portion of the core bearing the bristles, b. cutting the bristles in such a way as to form the convex and concave portions over all or part of the length L of the portion of core bearing the bristles, in order to obtain the brush, for example by milling, particularly by moving a cutting tool parallel to the longitudinal axis of the core.

A subsequent step may involve bending the longitudinal axis of the core so as to make it curved.

Makeup method

A further subject of the invention is a makeup method, in which a brush according to the invention, as defined above, is loaded with product, notably with cosmetic, makeup or care product, and then the product is applied to the surface to be made up, notably the eyelashes or the eyebrows, preferably by performing a translational movement of the brush with respect to the surface to be made up, notably with respect to the row of eyelashes or eyebrows. The translational movement may be performed transversely, notably substantially at right angles to the longitudinal axis X of the core.

The translational movement of the brush makes it possible to bring the surface to be made up into contact with a zone of the brush that is very heavily laden with product, in particular a concave portion, and then with a zone that promotes combing, in particular a convex portion.

The method may involve the step of performing a rotational movement of the brush, notably prior to the translational movement, after the brush has been brought into contact with the eyelashes or eyebrows, notably with the base, the root, of the eyelashes or eyebrows. Detailed description

The invention may be understood better from reading the following detailed description of nonlimiting exemplary embodiments thereof and from studying the appended drawing, in which:

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

- figure 2 is a cross section of one example of a brush according to the invention,

- figures 3 and 4 schematically illustrate application of make up using the brush of figure 2, and

- figures 5 and 6 are views similar to figure 2 of alternative forms of embodiment.

In the rest of the description, identical elements or elements having identical functions bear the same reference sign. 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 comprises a container 2 containing a product P to be applied to the eyelashes or the eyebrows and an applicator 3 which may, in the example in question, be fixed removably to the container 2. The product P comprises, for example, one or more pigments, notably an iron oxide. It is for example a mascara.

The applicator 3 comprises a stem 5, of longitudinal axis Y, provided at a distal end 5 a with a brush 10 according to the invention and at the other end with a gripping member 11 , which likewise forms a cap for closing the container 2 in a sealed manner. 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 sealed manner. In an alternative form the applicator can be fixed to the container in some other way.

The neck 14 may accommodate, as illustrated, a wiping member 20 which is for example inserted into the neck 14. This wiping member 20 comprises a lip 26 that defines a wiping orifice having a diameter adapted to that of the stem 5. The brush 10 may be fixed, in a conventional manner, in a seat provided at the distal end 5 a of the stem 5, which is advantageously made of a thermoplastic material. The brush 10 comprises a twisted metal core 40 comprising a portion 43 bearing bristles 41. The core is fixed at a proximal end 40a in the corresponding seat of the stem 5, via a portion without bristles that may have a length of around 8 mm. The core bearing the bristles has a free distal end 40b.

The bristles 41 extend along a length L of the core of preferably between 25 mm and 35 mm, for example equal to 30 mm.

The core 40 is formed conventionally by two arms of a metal wire folded in a U- shape, the bristles 41 being held between the turns of the core 40. The diameter of the metal wire is for example between 0.1 and 1 mm. The diameter of the bristles is for example between 0.06 and 0.35 mm.

The core 40 of the brush 10 is rectilinear in the example in question, extending along a rectilinear longitudinal axis X. As an alternative, it is curved. The free ends of the bristles 41 define, as illustrated in figure 2, an envelope surface S of the brush 10. The maximum radius of the envelope surface S, corresponding to the radius of the smallest cylinder of revolution in which the brush can be inscribed, is between 3 mm and 6 mm, for example 4.5 mm.

As illustrated in figure 2, the envelope surface S exhibits, in this example over a predefined angular range a of 180°, at least one convex portion 50 and at least one concave portion 51. The envelope surface S comprises a point of inflection 54 between the convex portion 50 and the concave portion 51 that are contiguous with one another, at which point the envelope surface S crosses its tangent T at this point of inflection 54, this point forming the point at which the convex 50 and concave 51 portions meet. The convex portion 50 covers an angular extent in excess of 10°, in this example an angular extent β of between 60° and 90°. The concave portion 51 itself covers an angular extent γ of between 60° and 120°.

In this example there is also a second convex portion 52, separated from the convex portion 50 by the concave portion 51. The boundary between the concave portion 51 and the convex portion 52 forms a catching edge corner 53 on the angular range a.

The envelope surface S exhibits a portion in the overall shape of an S in the angular range a when viewed in figure 2, formed by the convex portion 50 and the concave portion 51. It should be noted in this example that the envelope surface is symmetric about a midplane M containing the largest diameter D passing through the core. The cross section of the envelope surface S can be inscribed inside a circle C, the envelope surface S being inscribed inside a cylinder of cross section corresponding to the circle C. As can be seen, in this embodiment, the convex portion 52 is formed by part of the circle C and part of the convex portion 50 is also formed by part of the circle C, diametrically opposite the convex part 52.

The boundary between a concave part 51 and a convex part 52 is formed by an edge corner 53 formed by the vertex of a sharp-angled corner that is salient in cross section.

With respect to the axis formed by the largest-dimension diameter D, the envelope surface S is symmetric, thus exhibiting, as can be seen in figure 2, the overall shape of a fish with a head formed by the convex portion 50 and a convex portion 55 which is symmetric therewith, and a tail formed on the one hand by the concave portion 51 and a concave portion 56 which is symmetric therewith and on the other hand by the convex portion 52 and a convex portion 57 which is symmetric therewith. The convex portions 50 and 55 are situated adjacent to one another, as are the convex portions 52 and 57. It should be noted that this symmetry in the plane of a cross section illustrated in figure 2 can be reproduced over the entirety of the length L of the portion of the core 40 bearing the bristles 41, or over just part of this length.

It should also be noted that the envelope surface S exhibits an edge corner 58 which is symmetrical with the edge corner 53, and a point of inflection 54' that is symmetrical with the point of inflection 54, about the diameter D in figure 2.

The cross section of the envelope surface S exhibits, over an angular range a' also of 180°, which is symmetric with the angular range a, the convex portion 55, the concave portion 56, separated from the convex portion 55 by the point of inflection 54', and the convex portion 57, separated from the concave portion 56 by the edge corner 58.

The convex portions 50 and 55 may each be divided into two portions, namely a first portion 60 and a second portion 61 that is symmetric about the diameter D, which do not extend on the circle C but inside the latter, and convex portions 62 and 63 that together form an arc of the circle C inside which the cross section of the brush can be inscribed.

By virtue of the invention, the product, notably mascara, is transferred increasingly quickly from the brush to the eyelashes or the eyebrows of the top and bottom eyelids G of the eye O. Along the entire length of the brush, in this example, the most heavily laden zone formed by the concave portions 51 and 56 allows the supply of product while the more comprehensively wiped zone with longer bristles of the convex portions 50 and 52, 55 and 57 allows the combing of the lashes. In addition, the more slender part formed by the concave portions 51 and 56 allows the making-up of the bottom lashes and allows access to the root of the top lashes, particularly via the catching edges 53, 58.

The hand movements involved in applying makeup using the brush according to the invention have been illustrated in figures 3 and 4. In a catching phase, one of the lash- catching edge corners 53 or 58 provided on the brush and possibly the convex entry portion formed by the arc of a circle C of the convex portions 52 and 57 is brought into contact with the root of the lashes by positioning the midplane M of the brush, passing through the diameter D, substantially perpendicular to the lashes. The brush is then rotated in the clockwise direction, for example about its longitudinal axis X, which rotation has been performed between figures 3 and 4, as can be seen.

The brush now has its midplane M substantially parallel to the lashes, as can be seen in figure 4. An application phase performed now involves a translational movement along the lashes K toward and as far as their free ends, in the direction of the arrow illustrated in this figure. In this application phase, the portions of the lashes K covered by the brush successively encounter the convex entry portion formed by the convex portions 52 and 57 and the catching edges, for example the catching edge 53 as visible in figure 4, the concave portion 51 (or 56) laden with mascara and then the convex separation and combing portion formed by the convex portions 50 and 55. The concave portions 51 and 56 are able to become loaded by accumulating product that has been less comprehensively wiped off by the wiping member 20. The convex portions 60 and 61 have the role of combing and separating the eyelashes or eyebrows. The convex portions 62 and 63 form an exit convex portion, at which the brush can be extracted from the lashes.

The more slender part formed by the concave portions 51 and 56 and the lash- catching edge corner 53 or 58 can be used for the making-up of lashes at the bottom of the eye, which are finer and shorter than the lashes at the top of the eye. A similar set of hand movements to those used for the top lashes can be used for making up the lashes at the bottom of the eye. Thus, by virtue of the invention, without turning the brush and simply using a translational movement illustrated by the arrow in figure 4, it is possible to pass on from a loading zone formed by the concave portions 51 and 56 to a combing zone formed by the convex portions 60 and 61.

The brush illustrated in figures 2 to 4 has been embodied by cutting a blank of which the envelope surface S of the bristles forms a cylinder of cross section corresponding to the circle C. The vertical cuts along all or part, in this example along all, of the length L of the portion of the core bearing the bristles, have been made symmetrically about the vertical midplane M of the brush passing through the core.

As an alternative, only part of the length of the portion of the core bearing the bristles comprises such cuts.

In the example illustrated, the core is rectilinear but it could be curved without departing from the scope of the invention.

Symmetry may allow the brush to be held left-handed or right-handed, according to the wishes of the user.

In the alternative form illustrated in figure 5, only the angular range a of 180° comprises a concave portion and at least one convex portion, which are separated by the point of inflection 54. In this example there is no symmetry about the diameter D passing through the core 40. Also, only the catching edge corner 53 and a succession of convex 50, concave 51 , then convex 52 portions are present. The rest of the cross section of the brush, namely in the 180° angular part that is the complement of the angle a, is still inscribed inside the circle C and exhibits a circular shape.

In the example illustrated in figure 6, the cuts to the brush have been made in such a way as to form, in the angular range a, only a convex portion 50 followed, after the point of inflection 54, by a concave portion 51 ending with a lash-catching edge corner 53. In this example there is axial symmetry about the diameter D passing through the core 40.

Of course, other combinations of concave and convex portions are possible without departing from the scope of the invention.

Generally, the envelope surface S can comprise a varying number of concave portions and of convex portions and it is possible for the latter not to be identical to those illustrated in figures 2, 5 and 6. The ends 40a and 40b of the envelope surface S may be chamfered. This can make it easier for the brush to pass through the wiping member 20. The chamfer at the distal end and the chamfer at the proximal end may be different. The chamfer at the distal end may, notably, be less inclined than that at the proximal end. In an alternative form, it is possible for the brush not to have such end chamfers.

The invention is not limited to the illustrative embodiments that have just been described, the features of which may be combined with one another within alternative forms that are not illustrated.