Title: Device for treating the hair

Technical field

The present invention relates to devices for treating the hair, and more particularly, but not exclusively, those intended for shaping the hair, in particular for curling and/or straightening the hair.

The invention relates more particularly to curling devices having two jaws that are movable with respect to one another and are able to take up a spaced-apart configuration for introducing a lock of hair between said jaws and a moved-together configuration for treating the lock.

Prior art

Numerous devices of this type have already been proposed. These devices generally have heating plates on their external surfaces around which the locks of hair are wound in order to be curled.

Some devices also have internal heating plates, between which the locks can be gripped during curling and/or for straightening the hair.

In some cases, the hair is treated without using the external heating plates, which may nonetheless be hot during the treatment. The user must then avoid contact with these hot surfaces to avoid burning the skin or the scalp.

US20060037625 discloses the application, using an adhesive, of a thermal protection material to the hot surfaces.

KR20-0246302, KR200398545, KR10-0712248, CN203676383 and CN110338540 describe the possibility of mounting thermal protection covers, removably, on the heating surfaces to protect the user.

There is a need to improve the protective covers of hair treatment devices, in particular to facilitate mounting and removal of these covers.

There is thus a need to further improve devices for treating the hair, in particular in order to benefit from a safe, versatile, efficient device that is simple and comfortable to use, operates reliably and has a cost compatible with mass distribution.

There is also a need for a hair curling device that can also be used effectively as a straightener.

Disclosure of the invention The present invention meets all or some of these needs by virtue, according to one of its aspects, of a device for treating the hair, in particular for shaping, in particular curling the hair, having: two hair treatment jaws that are movable relative to one another between a spaced-apart configuration for inserting hair to be treated between said jaws and a moved-together configuration for treating the hair, an external treatment member having an external surface for heating the hair, which extends over one of the two jaws towards the exterior of the two jaws, a thermal protection cover mounted removably by being clip-fastened on the device so as to at least partially cover the external heating surface, the cover having a recess configured to form a preferential deformation zone of the cover when it is fitted on the device.

The protective cover makes it possible to protect the access to the hot surface of the external heating surface when it is not being used for a treatment, for example, when the device is being used for straightening, while making it possible to remove this protection when the external heating surface is being used in particular for curling the hair or making it wavy.

In use, the cover prevents accidental contact of the user’s head, ears, cheeks, neck or fingers with the external heating surface, without impeding or complicating or detracting from the use of the device.

This results in an efficient device that can be used to straighten or curl the hair while protecting the user from burns depending on the type of use. Use is therefore safer compared to prior art products.

Moreover, the recess in the cover makes mounting and removal of the cover on/from the device easier and more reliable, while being less expensive to produce.

The device may have two arms, the distal parts of which each form one of the two jaws; these two arms are preferably hinged together at their proximal ends, opposite to the jaws, and may each have a gripping area, next to the hinge, from which the jaw extends and on which the user can press to move the jaws between the spaced-apart and moved- together configurations.

Preferably, each jaw has an elongate shape and extends along a longitudinal axis, which is preferably a rectilinear axis. The device may thus have an elongate shape along a longitudinal, preferably rectilinear, axis in the moved-together configuration of the jaws.

External treatment member

The device may have two external treatment members that each extend over one of the jaws and each have at least one external hair heating surface extending over the respective jaw towards the exterior of the device, preferably being on opposite sides to one another on the device in the moved-together configuration of the jaws, the device having two thermal protection covers that are mounted removably on the device and are each arranged on one of the two external heating surfaces so as to at least partially cover said external heating surface, each cover having a recess configured to form a preferential deformation zone of the cover when it is fitted on the device.

Preferably, when there is only one external treatment member having an external heating surface, this member extends over the jaw having the lateral recess.

The or each external treatment member may have an external plate extending over the external surface of the corresponding jaw and having a shape substantially complementary to the latter. The external plate or plates have an external surface for contact with the hair at least partially defining the external heating surface of the external treatment member.

The or each external plate may be made of a material that is a good conductor of heat, the external heating surface or surfaces exhibiting a temperature for example greater than 50°C, better still between 55° and 150°C when the device is in use, for example around 90°C.

The or each external surface may be made of metal, or of ceramic, preferably of stainless steel, for example stainless steel 304 according to the standard JISG4305.

The or each external plate may have a thermal conductivity of at least 20 W.nT ^K’ ¹ . Such conductivity allows rapid heating of the external heating surface or surfaces and effective application of heat to the hair.

The or each external heating surface may be elongate along a longitudinal axis of the jaw bearing it.

The external heating surface or surfaces and the internal heating surface or surfaces may at least partially have one and the same space requirement in the median plane of the device extending between the two jaws in the moved-together configuration of the jaws. This makes it possible to use both the internal and external surfaces to treat one and the same lock of hair, if desired, for example during a curling operation.

Preferably, the two external heating surfaces are substantially the same length along their respective jaws.

Preferably, the or each external heating surface has an outwardly convex shape, in particular a semicylindrical shape.

The or each external plate may have fastening elements configured to cooperate with complementary elements of the corresponding jaw; the or each external plate may have inwardly curved longitudinal edges configured to be fastened to the external body of the jaw, in particular by fitting in corresponding longitudinal grooves extending over the external body of the jaw along the longitudinal axis of the jaw. Such fastening of the external plate or plates via curved edges makes it possible not to have a salient edge comer of the external plate or plates coming into contact with the hair wound around the jaw.

Preferably, the external treatment member extends over only a part of the external surface of the jaw, in particular over the part of the external surface of the jaw that is oriented at least partially towards the opposite side from the internal heating surface of the jaw.

Preferably, the or each external plate is separate and distinct from the or each internal plate.

The internal heating surface and the external heating surface that are borne by the same jaw may be heated by thermal conduction via one and the same heat source extending in said jaw.

In a variant, the external heating surface and the internal heating surface that are borne by the same jaw may be heated by respective separate heat sources.

One of the jaws, in particular each jaw, may have a distal portion that does not have an external and/or internal plate for heating the hair, in particular with a sufficient length to be grasped by the user. This distal portion may allow the user to grasp the device in its distal part without burning themselves, this being particularly useful when the device has a member that exerts a pulling force on the hair, such as a comb, as will be shown below, since a greater force may then be necessary to move the device along the hair. Said distal portion that does not have an external and/or internal plate for heating the hair may extend along a length, along a longitudinal axis of the device, of between 10 mm and 50 mm, preferably between 20 and 40 mm, advantageously between 25 mm and 30 mm.

Said distal portion that does not have an external and/or internal plate for heating the hair may have one or more reliefs that make it possible to keep the finger on the distal portion while limiting the risk of contact with the external heating surface or surfaces.

The length of the or each external treatment member may be between 50 mm and 150 mm, preferably between 80 and 100 mm, advantageously around 88 mm.

The external treatment member, in particular the entire external surface of the jaw over which the external treatment member extends, may be free of projecting combing teeth, in particular free of any projecting relief, preferably smooth, over a length greater than or equal to 50% of its length, better still greater than or equal to 80% of its length, still better still over its entire length.

The external treatment member may be in one-piece.

The width of the jaw carrying the external treatment member, at the level of external treatment member, may be smaller than the width of the other jaw at the same level.

The external treatment member may extend laterally over the entire width of the jaw.

The side edges of the jaw, on which the external treatment member extends, may extend laterally strictly between the side edges of the other jaw over the entire length of the external treatment member, in particular the side edges of the other jaw may face each a hollow zone of the jaw on which the external treatment member extends.

External guiding portion

At least one jaw, preferably each of the two jaws, may have an external hair guiding portion. The or each external guiding portion may be delimited laterally in the proximal and/or distal part of the jaw, better still in the proximal and distal part of the jaw, by a stop surface such as a shoulder. The or each external heating surface may extend, at least partially, better still entirely in the external hair guiding portion of the corresponding jaw. Preferably, the length of the external guiding portion along the longitudinal axis of the jaw is substantially equal to the length of the corresponding external heating surface along the longitudinal axis of the jaw. As a result, the or each external hair guiding portion may form a visual reference for the user, indicating the external treatment zone, thereby helping to position the hair properly.

At least one stop surface may comprise a flat portion, particularly in a plane transverse to the jaw, particularly flat over a width at least equal to 50% of the width of the jaw, preferably 80% of the width of the jaw, better still 100%, at the level of said stop surface.

The or each guiding portion may be formed at least partially, preferably entirely, by the lateral recess on one side of one of a jaw, the other side of said jaw being deprived of lateral recess.

The or each guiding portion may extend over the outer surface of the corresponding jaw, in particular in cross section over the entire outer surface of the jaw. The or each stop surface may extend transversely to the external surface of the jaw, in particular extend in a plane forming a non-zero angle, in particular between 70° and 110°, with the longitudinal axis of the jaw, and in particular extend in a plane substantially orthogonal to the longitudinal axis of the jaw. The or each stop surface may extend around the entire circumference of the jaw, in particular over the entire outer surface of the jaw in section in its plane of extension.

Lateral recess

One of the jaws may have a lateral recess along at least a part of the jaw, the lateral recess facing at least a part of the other jaw and being delimited in a proximal and/or distal part of the jaw by a guiding surface affording an obstacle to contain the hair to be treated within the lateral recess.

The lateral recess may be delimited in both the proximal and distal part by a guiding surface affording an obstacle to contain the hair to be treated within the lateral recess. The fact that the lateral recess is delimited by guiding surfaces on these two sides allows excellent guidance and optimal keeping of the hair in the recess while limiting the risk of it escaping from the recess.

The external surface of the jaw having the lateral recess may not have a salient longitudinal edge corner extending outwardly from the jaw. The outer surface of the jaw at the recess may thus be curved and continuous without a slope discontinuity with the rest of the surface of the jaw.

The or each guiding surface may have a variable height. The greatest height of the guiding surface or surfaces may be between 0.5 mm and 1 cm, better still between 1 mm and 5 mm. Preferably, the height is at a maximum, for example equal to 5 mm, at its lateral part. In other words, the lateral recess forms an indentation of 5 mm maximum depth.

Preferably, the jaw having the lateral recess has a width measured, at the lateral recess, parallel to the median plane of the device defined by the internal treatment surface in the moved-together configuration of the jaws, that is less than or equal to the width of the other jaw, and in particular has a width of between 50% and 95%, better still between 70% and 90%, of the width of the other jaw.

The lateral recess may extend in the guiding portion of the corresponding jaw, the guiding surface or surfaces being formed by the stop surface or surfaces of the guiding portion.

Thus, the stop surface or surfaces of the jaw having the lateral recess may have a variable height, in particular a greater height at the lateral recess. The variation in height of the stop surface or surfaces may be substantially continuous.

Preferably, away from the recess, the height of the stop surface or surfaces is substantially constant. In a variant, the stop surface or surfaces may have a variable height around the or each jaw, even away from the lateral recess.

Away from the recess, the greatest height of the stop surface or surfaces may be between 0.2 mm and 4 mm, better still between 0.5 mm and 2 mm.

The or each stop surface delimiting the external hair guiding portion may be at least partially formed by a rib extending over the external surface. The rib is, preferably, thicker opposite the internal heating surface or surfaces than laterally with respect to the internal heating surface or surfaces.

The or each external guiding portion may be set back with respect to a base level of the jaw bearing it, the base level of the jaw being the level of the jaw away from the external guiding portion and from the rib, where appropriate. The guiding portion is therefore a recessed portion of the jaw.

Removable cover

The or each cover may cover the entire corresponding external heating surface.

The or each cover may have a shape complementary to that of the corresponding external heating surface, in particular a curved shape, in cross section.

The cover may extend along a longitudinal axis, preferably intended to correspond to the longitudinal axis of the arms of the styling device when the cover is fitted on the latter, said recess having an elongate shape along a direction forming a non-zero angle with the longitudinal axis of the cover, in particular a right angle with the longitudinal axis of the cover. This makes it possible to give the cover a certain deformation elasticity, by elastic deformation of the material of which the cover is made along the longitudinal axis in order to make the operation of fitting and/or removing the cover easier.

The recess may be formed by a zone of reduced thickness or, preferably, be a through-recess, that is to say one made all the way through the thickness of the cover.

The recess may be symmetric with respect to a plane transverse to the longitudinal axis of the cover. Optionally, the notch has one or more waves at the surface of the cover.

The recess may have a width that is substantially constant along its entire length.

The width of the recess may be between 0.1 and 3 mm, preferably between 0.5 and 2 mm, and is for example equal to 1 mm.

The recess may extend over at least 50%, better still at least 70% of the developed width of the cover.

The term “developed” means when the cover is fictitiously spread out to extend along a plane.

The recess may extend over the cover at a distance from one of the proximal or distal ends of the cover of less than or equal to 25% of the length of the cover. For example, the recess is situated at a distance of between 1 and 20 mm, preferably between 1 and 10 mm, for example 3 mm, from one of the proximal or distal ends of the cover. This makes it possible to limit the size of the elastically deformed zone.

Preferably, the cover has a gripping protrusion extending from the external surface of the cover when it is mounted on the jaw. The gripping protrusion may extend over one of the proximal or distal ends of the cover. Alternatively, the gripping protrusion extends at a distance from one of the proximal or distal ends of the cover of less than or equal to 25% of the length of the cover.

Preferably, the gripping protrusion and the recess extend respectively close to opposite longitudinal ends of the cover.

The cover may be configured to be mounted on the jaw such that the gripping protrusion is located close to the longitudinal end of the cover extending on the proximal side of the jaw. In other words, the gripping protrusion is situated close to the gripping zone of the styling device, or on the side of the hinge of the latter. This allows the user to detach the cover with the hand (in particular the thumb) holding the handle of the device by way of a single motion and therefore makes it easier to handle the cover.

The cover and the jaw may have complementary reliefs for fastening the cover to the jaw; the cover may in particular have first, preferably protruding, reliefs extending at its two longitudinal ends, arranged so as to cooperate with second, complementary, preferably recessed, reliefs on the rest of the device, to ensure the fastening of the cover to the rest of the device. Such first reliefs may have a thickness equal to or less than the thickness of the longitudinal end of the cover.

The second reliefs may have the same dimensions.

In a variant, the second reliefs have different dimensions, for example to ensure foolproofing.

The first reliefs may extend from the corresponding longitudinal end of the cover along a direction parallel to the longitudinal axis of the cover.

The second reliefs may extend from or in the stop surfaces of the external guiding portion.

Preferably, the cover is symmetric with respect to a longitudinal median plane.

The cover may have a, preferably variable, thickness of between 0.5 mm and 2 mm, preferably between 1 mm and 1.5 mm. Preferably, the cover is, in cross section, thicker at the centre than at its longitudinal edges.

The cover is preferably made of a material that is resistant to a temperature of at least 60°C, better still at least 100°C.

The cover may be made of reinforced or non-reinforced plastic, in particular of polybutylene terephthalate (PBT) or polyamide (PA), with or without glass fibres.

The cover may have stiffening ribs.

The cover may have interior stiffening ribs. These ribs make it possible to enhance the thermal insulation by providing a layer of air between the external surface and the cover.

Preferably, the cover is configured to be mounted on the device by cooperation of the first relief extending at one longitudinal end of the cover, in particular the opposite one to the gripping protrusion, with the second relief and by pivoting of the cover on the rest of the device about a pivot axis, in particular transverse with respect to the median plane of the cover, in order to snap-fasten the first relief extending at the other longitudinal end of the cover in the complementary second relief on the rest of the device. During fitting, the preferential deformation zone formed by the recess allows local and controlled deformation of the cover. This deformation occurs in particular when the user exerts pressure from the gripping protrusion. By virtue of this movement, the first relief on the gripping protrusion side may, during pivoting, come to face the corresponding second relief.

Once pivoting is complete, when the cover is in contact with the external surface, the longitudinal pressure is released, allowing the cover to return to its initial shape. The first relief on the gripping protrusion side then cooperates with the corresponding second relief.

To remove the cover, the reverse operation is carried out.

Thus, by virtue of this local, elastic and controlled deformation, that is to say deformation provided by the designers of the cover, a functional clearance along the longitudinal axis appears when the user fits the cover on or removes it from the device, thereby making the operations of fitting and removing the cover remarkably easier. Moreover, such deformation makes it possible to compensate and take into account the manufacturing tolerances of the different parts, thus ensuring proper fitting and removal for all cover/device pairings.

Moreover, by virtue of the simplification of these operations, the user is further encouraged to use the thermal protection cover or covers when they are not using the external treatment surface or surfaces, since they know that the fitting and removal operations will be simple and intuitive. The risk of burning the cheeks, hands, ears, neck or scalp during straightening operations in particular (or any other operation that does not require the use of external surface(s)) is thus reduced.

Internal treatment member

The device may comprise at least one internal treatment member having an internal surface for heating the hair to be treated, which extends over one of the two jaws towards the other of the jaws in the moved-together configuration of the two jaws and is configured to come into contact with the hair extending between the two jaws in the moved- together configuration thereof.

The device may have an internal counter-bearing surface, facing the internal heating surface in the moved-together configuration of the jaws, which is intended to grip, with the internal heating surface, the hair to be treated in the moved-together configuration of the jaws. The internal counter-bearing surface may have a shape complementary to the internal heating surface.

Preferably, the internal heating surface and the counter-bearing surface are substantially the same length and/or the same width.

The internal counter-bearing surface may also be an internal heating surface of an internal treatment member, the device having, in this case, two internal treatment members that each extend over one of the jaws and each have at least one internal heating surface, the internal heating surfaces facing one another and being configured to grip the hair between them in the moved-together configuration of the jaws.

Preferably, the internal heating surface and the counter-bearing surface have an elongate shape along the jaw that bears them, in particular along an axis parallel to a longitudinal axis of this jaw.

Preferably, the internal heating surface and the counter-bearing surface have treatment surfaces coming into contact with the hair that are substantially planar.

In a variant, the internal heating surface and the counter-bearing surface are not planar, being in particular curved, recessed or wavy.

The internal heating surface may have surface reliefs, in particular protruding reliefs such as teeth. In this case, the counter-bearing surface may be planar or also have surface reliefs, in particular protruding reliefs extending between the protruding reliefs on the internal heating surface in the moved-together configuration of the jaws.

Preferably, the internal heating surface has a treatment surface coming into contact with the hair which has a substantially rectangular shape.

The or each internal treatment member may have an internal plate extending between the jaws having a contact surface with the hair, the contact surface with the hair forming the internal heating surface.

The internal plate or plates may be made of a material that is a good heat conductor, the internal heating surface or surfaces exhibiting a temperature for example greater than 50°C, preferably between 90°C and 230°C in use, advantageously between 180°C and 210°C. The or each internal plate may be made of metal, preferably aluminium, in particular with hard anodization.

The or each internal plate may have a thermal conductivity of at least 20 W.nT ^K’ ¹ . Such conductivity allows rapid heating of the or each internal heating surface and effective heat transfer to the hair extending between the internal heating surface and the counter-bearing surface.

The internal treatment member or members may be mounted on the corresponding jaw by being inserted into a housing in the jaw that opens towards the other jaw.

The or each internal treatment member may have a support bearing the internal plate, the support being mounted in the housing in the corresponding jaw.

The internal treatment member or at least one of the internal treatment members, in particular the support or at least one of the supports, may be able to move in translation in the housing along an axis perpendicular to a median plane of the device extending between the two jaws in the moved-together configuration of the jaws and/or by tilting in the housing. The maximum height of tilting and/or of movement in translation from the rest position of the or each treatment member may be between 0.5 mm and 5 mm.

The term “tilting” should be understood as meaning that the internal treatment member or at least one of the internal treatment members, in particular the support or at least one of the supports, can exhibit a rotary movement about at least one axis, it being possible for the movement of the or of each internal treatment member to be a more complex movement, with rotary components about several axes, in particular about or parallel to the longitudinal axis of the or each internal treatment member and/or about or parallel to a transverse axis of the housing. In a manner known per se, the internal treatment member or at least one of the internal treatment members may for example be mounted on a ball joint. The tilting of the internal treatment member or of at least one of the internal treatment members makes it possible to exert a more uniform pressure along the entire length of the internal heating surface and to take into account the closing angle of the jaws depending on the thickness of the hair. This allows uniform application of the heat and pressure to the hair.

The internal treatment member or at least one of the internal treatment members, in particular the support or at least one of the supports, may be mounted in contact, in the housing, with a support means configured to allow the movement of the corresponding internal treatment member in the housing. The support means may be as described in FR3011449.

The support means may be rigid; in a variant, it is elastically deformable. In a further variant, the support means has a zone in which contact is made rigidly and one or more zones in which contact is made with one or more elastic return members which are designed for example to return the corresponding treatment member into a predefined rest position when there is no mechanical loading by the applicator member. The elastic return member or members may be coil springs or leaf springs.

Preferably, the support means allows the internal treatment member to tilt in the housing and has a protruding relief at the bottom of the housing and/or of the corresponding treatment member, in particular of the corresponding support. The protruding relief may be hemi-spherical, or in the shape of a substantially conical tooth, or in the form of a halfcylinder oriented perpendicularly to the longitudinal axis of the internal treatment member.

In a variant or in addition to the protruding relief, the support means has at least one spring, in particular a leaf spring, disposed in the housing, for example fastened to the bottom of the housing or fastened to the internal treatment member, in particular to the support. The support means may have at least two springs, in particular two coil springs that are disposed in the housing, fastened to the bottom of the housing or fastened to the internal treatment member, in particular to the support, and disposed in particular close to the axial ends of the corresponding internal treatment member. It is then possible for the internal treatment member to tilt on account of the elastically deformable nature of the springs.

The internal treatment member or at least one of the internal treatment members may be able to move along an axis perpendicular to the median plane of the device extending between the jaws in the moved-together configuration of the jaws from a high position along a maximum depression travel defined by a relief of the corresponding internal treatment member, coming into contact with the bottom of the housing, and/or by cooperation between ribs and lateral grooves of the housing and of the internal treatment member, in particular of the support, the grooves being wider than the corresponding ribs, such that the ribs are able to move in translation in the grooves along the abovementioned axis between two positions.

The internal treatment member may extend laterally strictly between the two side edges of the external treatment member.

The internal treatment member may extend laterally strictly between the two side edges of the outer surface of the jaw on which the internal treatment member extends.

Internal treatment member rear structure

The internal treatment member or at least one of the internal treatment members, in particular the internal plate or at least one of the internal plates, and preferably each of them, has, between the jaws, a first lateral edge and a second lateral edge opposite to the first lateral edge.

The device may include a recess in the jaw between the first or second, preferably the first, lateral edge of the internal treatment member and the outer surface of the jaw carrying the corresponding internal treatment member and adjacent to the corresponding internal treatment member.

Said recess may be configured so that, when hair under mechanical tension between the said lateral edge and the said outer surface of the jaw, at least a portion of the hair is free from contact with the device at the recess level.

Said recess may be in the form of a groove extending substantially along the longitudinal axis of the corresponding jaw between the internal surface of the treatment member and the said outer surface of the jaw.

The first lateral edge may be configured such that an angle formed between a median plane of the device, extending between the jaws in the moved- together configuration of the jaws, and hair under mechanical tension, bearing on the first lateral edge of the corresponding internal treatment member, in particular of the corresponding internal plate, and on an outer surface of the jaw bearing the corresponding internal treatment member, this outer surface being adjacent to and separate from the corresponding internal treatment member, in particular from the corresponding internal plate, is less than or equal to 120°, better still less than or equal to 110°, and strictly greater than 90°, better still greater than or equal to 95°, better still equal to 105°±5°, better still equal to 105°±3°, notably at rest.

When the internal treatment member or at least one of the internal treatment members, in particular the support or at least one of the supports, is able to move in translation in the housing along an axis perpendicular to a median plane of the device extending between the two jaws in the moved-together configuration of the jaws and/or by tilting in the housing, the device may be configured such that, whatever the position of the internal treatment member is in the housing, the angle mentioned above for hair under mechanical tension bearing on the first lateral edge of the corresponding internal treatment member and on an outer surface, adjacent to and separated from the corresponding internal treatment member, of the jaw bearing the corresponding internal treatment member are respected. The angle formed between a median plane of the device, extending between the jaws in the moved-together configuration of the jaws, and hair under mechanical tension, bearing on the first lateral edge of the corresponding internal treatment member and on an outer surface, adjacent to and separated from the corresponding internal treatment member, of the jaw bearing the corresponding internal treatment member, is designed to ensure the best curling and proximity to the root of the hair in all the configuration of use of the device, even in the case wherein the internal treatment member or at least one of the internal treatment members, in particular the support or at least one of the supports, is moved in translation.

Said outer surface may be offset from the internal treatment member by a nonzero distance when the device is viewed along its longitudinal axis.

The first lateral edge may extend so that it forms a protruding lateral relief.

The expression “hair under mechanical tension ' should be understood as meaning that the hair extends along a straight line between the first lateral edge and the adjacent outer surface of the jaw bearing the corresponding internal treatment member. In other words, the above angle is thus defined between the median plane defined between the jaws in the moved-together configuration of the jaws and a fictitious plane in contact with the first lateral edge, for the one part, and with the adjacent outer surface of the same jaw, for the other part. This mechanical tensioning is realized in particular by virtue of the internal treatment member or members by gripping and by virtue of the movement of the device along the lock of hair.

Such an angle with the outer surface of the jaw makes it possible for a curl to be well formed during the curling of the hair, by the hair bearing on the first lateral edge and an adjacent outer surface of the jaw, in particular like the loops created with a blade passed over a gift ribbon. Moreover, with such an angle, the first lateral edge is relatively close to the outer surface of the jaw, without however protruding beyond the latter. This makes it possible, in particular during the straightening of the hair, to bring the first lateral edge close to the scalp, and therefore to increase the portion of hair treated, without, however, touching the scalp. This therefore allows treatment as close as possible to the roots of the hair while maintaining the user’s comfort, in spite of the temperature of the internal surface or surfaces. The first and the second lateral edge of the or each internal treatment member may each extend along a longitudinal axis of the jaw bearing the corresponding internal surface.

The first lateral edge may be closer to the outer surface, adjacent thereto, of the jaw bearing the internal treatment member than the second lateral edge is to the outer surface, adjacent thereto, of said jaw. In other words, the or each internal treatment member may be laterally offset upstream or downstream, preferably downstream, the hair being moved from upstream to downstream during the treatment.

The two internal treatment members may have one and the same space requirement in the median plane of the device extending between the two jaws in the moved- together configuration of the jaws.

Each internal plate, or at least one of the internal plates, may protrude laterally from the abovementioned housing at the first lateral edge by a distance greater than or equal to 0.5 mm, preferably greater than or equal to 0.8 mm, and/or less than or equal to 2 mm, better still less than or equal to 1.3 mm. For example, each internal plate, or at least one of the internal plates, may protrude laterally from the abovementioned housing at the first lateral edge by a distance of 1 mm.

Each internal plate, or at least one of the internal plates, may protrude laterally from the abovementioned support at the first lateral edge by a distance greater than or equal to 1 mm, preferably greater than or equal to 1.5 mm, and/or less than or equal to 3 mm, better still less than or equal to 2 mm.

The support of the or each internal treatment member may, at rest, extend towards the other jaw, in particular with a height at rest of between 1 mm and 8 mm, preferably between 2 mm and 5 mm, in particular greater than or equal to the maximum height of tilting and/or movement in translation.

The internal treatment member borne by the support may be spaced apart by more than 4 mm from the opening of the housing of the support towards the other arm.

The term “at rest” is understood as meaning in the spaced-apart configuration of the jaws.

Preferably, the, at least one or each internal treatment member, in particular the, at least one or each internal plate, is asymmetric with respect to a median plane of the housing of the corresponding jaw, orthogonal to the median plane of the device extending between the jaws in the moved-together configuration of the jaws, and in particular may exhibit a transverse distance between the first lateral edge and the transverse median plane of the housing greater than that between the second lateral edge and the transverse median plane of the housing.

The, at least one or each internal treatment member, in particular the, at least one or each internal plate, may be spaced apart from a plane lying laterally on the outer surfaces, adjacent to and separate from the corresponding internal treatment member, of the two jaws by a distance at rest that is less than or equal to 6 mm, better still less than or equal to 5.5 mm.

The first lateral edge of the or of each internal treatment member is, preferably, on the opposite side of the internal treatment member from the recess. The first lateral edge of the internal treatment member or of at least one of the internal treatment members, in particular of the internal plate or of one of the internal plates, may have an edge comer configured to come into contact with hair under tension bearing on the first lateral edge and the adjacent outer surface of the jaw bearing the internal treatment member. The edge comer may protmde, be chamfered or be rounded with a radius of curvature less than or equal to 3 mm, preferably less than or equal to 2 mm, advantageously equal to 1.5 mm. Such an edge comer makes it easier to curl the hair or make it wavy and makes it possible to achieve good shaping, in particular curling, results.

Additional treatment member

The device may have an additional hair treatment member extending from one of the two jaws towards the other jaw in the moved-together configuration of the two jaws and arranged on said jaw laterally with respect to the internal treatment member in the moved-together configuration of the jaws.

The external surfaces of the jaws may be deprived of any additional treatment member other than the external treatment member(s) mentioned above.

The additional treatment member makes it possible to add to the straightening or curling an additional treatment for improving the quality of the curling or straightening treatment. The fact that it is arranged laterally with respect to the internal plate allows the treatments by the internal plate and by the treatment member not to be simultaneous but in succession, this being advantageous in particular for improving straightening. Preferably, the additional hair treatment member extends over the jaw opposite the one bearing the recess. It may extend at least partially in the part of the jaw facing the lateral recess.

The additional treatment member may have a protruding element, in particular a comb, which extends from the jaw at least partially in the direction of the other jaw. The protruding element may be accommodated at least partially, in particular at least at its end, in the recess when the device is in the moved-together configuration of the jaws. This makes it possible to obtain a device that is particularly compact while improving the styling result and the ergonomics of the appliance, as will be described in detail below. The additional treatment member may extend parallel to a longitudinal axis of the corresponding jaw along the or each internal heating surface in the moved-together configuration of the jaws, being separated from the latter.

The term “separated” should be understood as meaning that the treatment member is offset from the heating surface by a non-zero distance, when the device is viewed along its longitudinal axis.

The additional treatment member may have at least one steam outlet and/or a cosmetic product applicator member and/or a member that exerts a pulling force on the hair, in particular a comb.

When the additional treatment member has a cosmetic product applicator member, the cosmetic product applicator member may have a porous member soaked with a cosmetic composition, in particular fed with product by a reservoir in contact with the porous member or with the aid of a dispensing mechanism which is actuated automatically or manually while the device is being used. The cosmetic product applicator member may be a refill mounted removably on the device.

The cosmetic composition may be a composition for cleaning, dyeing, bleaching, conditioning or shaping the hair. Preferably, the use of the device involves the application of at least one composition for shaping the hair. This composition for shaping the hair may be a composition for curling, setting, relaxing or straightening the hair, preferably for relaxing or straightening the hair.

The cosmetic composition may contain at least one active agent chosen from reducing agents, in particular thiols, oxidizing agents, in particular hydrogen peroxide or persalts (for example persulfates), colouring agents, in particular pigments, direct dyes or oxidation dyes. The cosmetic composition may also contain at least one active agent chosen from temporary shaping agents, in particular styling polymers that are preferably anionic, amphoteric or non-ionic, conditioning agents, in particular silicones, mineral or plant oils, plant waxes, cationic surfactants and cationic polymers, alkaline agents and acids.

Preferably, the cosmetic composition contains at least one agent chosen from oxidizing agents, reducing agents or alkaline agents of the hydroxide type.

Preferably, the additional treatment member has at least one steam outlet, in particular a longitudinal row of steam outlets or an elongate steam outlet, in particular in the form of a slot, along the longitudinal axis. The steam outlet or outlets extend preferably over the jaw that does not have the recess. The steam outlet or outlets preferably face an internal surface of the other jaw that is separate from the internal heating surface. The internal surface facing the steam outlet or outlets may have a steam containment hollow or groove facing the steam outlet or outlets. Alternatively or in addition, the steam outlet or outlets may extend in a hollow or a groove in the jaw that bears them.

Preferably, the additional treatment member has a comb. The latter extends preferably over and from the jaw that does not have the lateral recess in the direction of the other jaw. Preferably, it extends at least partially facing the lateral recess in the moved- together configuration of the jaws.

The comb may improve the distribution of the hair over the device for the treatment by the internal surface and/or the external surface, thereby improving in particular the distribution of the heat over the hair and the uniformity of the treatment of the hair.

The comb may be arranged on the corresponding jaw such that the distal end of its teeth is spaced apart by a non-zero distance from hair wound under tension around the two jaws in the moved-together configuration of the jaws.

The distal end of the teeth of the comb may be spaced apart, in the moved- together configuration of the jaws, from the jaw opposite the one bearing the comb, by a non-zero distance.

The comb may be spaced apart from the internal treatment member by a distance, measured between the edge of the internal treatment member, in particular of the internal plate, on the comb side and the base of the teeth on the internal treatment member side, of between 5 mm and 15 mm, preferably between 8 and 9 mm. The height of the teeth of the comb may be between 5 and 10 mm, preferably between 7 and 9 mm.

The comb may be removable, in particular mounted by sliding in a housing such as a longitudinal groove in the jaw. The comb may be kept in the housing by cooperation of shapes between the base of the comb and the longitudinal groove; in particular the base of the comb may have a relief cooperating with a complementary relief of the housing. The comb may have a gripping extension extending out of this housing when it is mounted on the corresponding jaw, making it easier to extract the comb from and insert it into its housing.

Preferably, the additional treatment member has a comb as described above and one or more steam outlets as described above, the steam outlet or outlets extending between the comb and the internal surface or surfaces for heating the hair. Such implantation makes it possible to clearly distinguish the treatment of each element.

Treatment method

A further subject of the invention is a method for treating the hair with the aid of one of the devices as defined above. The method may be straightening or curling the hair or making it wavy. The method for treating the hair may involve the insertion of a lock of hair between the two jaws and/or against at least a part of the external heating surface of the device and the movement of the device along the lock of hair, preferably from the root to the tip thereof, in particular keeping said device in the moved-together configuration of the jaws.

The method may involve the movement of the device along a lock of hair to carry out at least a heat treatment of the lock of hair by gripping between the two jaws and bearing against the internal surface by way of the counter-bearing and/or external surface of the device.

The method may also have a step during which the device is made to rotate about its longitudinal axis so as to wind the hair around one or more external heating surfaces.

The lock of hair entering the treatment device and leaving the treatment device has preferably undergone a change in orientation about the device greater than or equal to 150°, in particular greater than or equal to 200°, even better still greater than or equal to 250°. The curling angle may be at least 270°.

During the heat treatment by the external heating surface, the lock of hair may be guided against the external plate by the guiding portion of the device. Preferably, the additional treatment member has at least one steam outlet and the step of treatment with the additional treatment member involves a steam application step.

When the additional treatment member has a comb and one or more steam outlets, the treatment step with the additional treatment member may involve a step of combing the hair and a steam application step, the combing step preferably being carried out before the steam application step as the device moves over the lock of hair.

The method may involve the winding of the lock of hair around the two jaws in the moved-together configuration of the jaws, in particular when the device has an external heating surface on each of the jaws.

The steps of the method are preferably carried out in succession along the lock of hair, in particular from the root of the hair to the tip, in the following order:

Optionally combing and/or steam treatment / internal heat treatment / guidance of the hair / external heat treatment by winding over one or two jaws, or

Optionally combing and/or steam treatment / internal heat treatment / bearing against the first edge of the internal plate or of one of the internal plates / external heat treatment by the external heating surface of one of the jaws / guidance by the recess / optionally external heat treatment by the external heating surface of the other jaw.

The steam application is carried out, preferably, with a steam flow rate of less than or equal to 1 g/min.

The method may involve the thermal protection of the external heating surface or surfaces in order to prevent contact with the external heating surface or surfaces, in particular during hair straightening. This step is carried out in particular by fitting the cover as described above over the or each external heating surface of the device and/or removing the cover from the or each external heating surface of the device by pivoting the cover about a pivot axis perpendicular to the longitudinal axis of the device and parallel to the median plane of the device extending between the jaws in the moved-together configuration of the latter. The cover may be removed with the aid of the hand holding the device at the handle of the device.

The method may involve the application of a pressure to the distal end of the jaws in order to keep the jaws in the moved-together configuration so as to exert a greater force on the hair in said configuration of the jaws. The method may involve the fitting of the end piece or pieces as described above on the distal end of one or of both jaws before the application of said pressure.

Brief description of the drawings

The invention may be understood better from reading the following detailed description of non-limiting exemplary embodiments thereof and from examining the appended drawing, in which:

[Fig 1] Figure 1 illustrates a perspective view of an example of a device according to the invention,

[Fig 2] Figure 2 illustrates a perspective view of the distal end of the device in Figure 1,

[Fig 3] Figure 3 illustrates a view in cross section of an example of a device according to the invention,

[Fig 4] Figure 4 is an enlarged view of Figure 3 in the region of the treatment member,

[Fig 5] Figure 5 illustrates a perspective and partial view of the distal end of the device in Figure 1,

[Fig 6] Figure 6 is an enlarged view of Figure 3,

[Fig 7] Figure 7 illustrates an enlarged view of an edge of one of the internal plates of the device in Figure 3,

[Fig 8] Figure 8 illustrates, in isolation, the internal plates and the housings of the device in Figure 3,

[Fig 9] Figure 9 illustrates a perspective view of an example of a thermal protection cover according to the invention,

[Fig 10] Figure 10 illustrates a perspective view of another example of a thermal protection cover according to the invention,

[Fig 11] Figure 11 illustrates a perspective view of the distal end of a device having thermal protection covers according to the invention,

[Fig 12] Figure 12 is a view in longitudinal section of the device in Figure 11,

[Fig 13] Figure 13 illustrates a perspective enlarged view of the device in Figure 11 in the region of a shoulder,

[Fig 14] Figure 14 illustrates a perspective enlarged view of the device in Figure

11 in the region of another shoulder, and [Fig 15] Figure 15 illustrates a side view of the fitting of a thermal protection cover on a device according to the invention.

Detailed description

In the rest of the description, elements that are identical or have identical functions bear the same reference signs. For the sake of conciseness of the present description, they are not described for each of the figures, only the differences between the embodiments being described.

Figures 1 and 2 show an example of a hair treatment device 2 according to the invention.

This device 2 has two jaws 3 and 4 that are movable with respect to one another between a spaced-apart configuration (not shown) for the introduction of a lock of hair between said jaws, and a moved-together treatment configuration, illustrated in Figure 1.

The jaws 3 and 4 are borne by an upper arm 5 and a lower arm 6, respectively, which, in the example in question, are connected together at one of their ends by a hinge 8, the device 2 thus forming tongs.

The arms 5 and 6 define, between the hinge 8 and the jaws 3 and 4, respective half-handles 10 and 11 on which the user can press in order to move the jaws 3 and 4 together and thus grip the hair extending between the two jaws.

The width of the arms 5 and 6 at the half-handles 10 and 11 is less than that at the jaws 3 and 4. In a variant, the widths could be substantially identical, or the width of the arms 5 and 6 at the half-handles 10 and 11 could even be greater than that at the jaws 3 and 4.

The jaws 3 and 4 each have a convex outer surface and a substantially planar inner surface.

An elastic return member (not visible) is preferably provided to return the jaws 3 and 4 to a spaced-apart configuration, this elastic return member being for example a spring disposed around a hinge pin 8.

The invention is not limited to a particular manner of connecting the arms 5 and 6 together and the jaws 3 and 4 may be rendered able to move in some other way without departing from the scope of the present invention. However, the presence of a hinge is largely preferred for the ergonomics it provides. The device 2 extends, for example, along a longitudinal axis X. The device 2 has a line 17 designed to be able to supply the energy necessary for operation of the device. The line 17 may thus be an electric cord designed to connect the device to the electric mains. Without departing from the scope of the invention, the line could also be a fluidic line designed to supply the device with fluid (water for example).

The device may have a water reservoir for the production of steam.

A user interface (not shown in the figures) may be present on the device 2 in order to allow the user to control the operation of the device.

Heating plates

The device 2 may have an internal surface 45 for heating hair to be treated, on each of the two jaws 3 and 4 facing the other of the jaws, and facing one another in the moved-together configuration of the jaws 3 and 4 so as to define, between them, a heated treatment zone in the moved-together configuration of the two jaws 3 and 4. The two internal heating surfaces 45 are, for example, configured to grip between them the hair extending between the two jaws 3 and 4 in the moved-together configuration of the two jaws 3 and 4.

The two internal heating surfaces 45 are substantially planar, but do not have to be. They could have complementary wavy shapes or complementary curved shapes for example.

The internal heating surfaces are, in the example illustrated, formed by the contact surface of internal plates 16 made of a heat conducting material that each extend over one of the jaws. Each internal plate 16 constitutes an internal treatment member of the device.

In a variant that is not illustrated, only one of the jaws 3 or 4 may bear an internal plate 16 having a heating contact surface facing a counter-bearing surface of the other jaw 3 or 4. The counter-bearing surface may be formed by the body of the jaw or by an element attached to the jaw.

In the example illustrated, the internal plates 16 are each mounted in the cavity 30 of a support 9, which itself is mounted in a housing 38 of the corresponding jaw 3 or 4. The internal plates 16 are each mounted fixedly on the support 9. At least one of the supports 9 is mounted so as to be movable in its housing, as will be set out below. In a variant that is not illustrated, the internal plates may be mounted directly in the housing and optionally be movable in the corresponding housing, or the internal plates may be mounted on the support while being movable in the cavity, the support being fixed in the housing.

At least one of the supports 9 is movable perpendicularly to the longitudinal axis of the jaw in its housing 38, between a high position spaced apart from the bottom of the housing and a low position moved together therewith.

The travel of the support 9 and the tilting thereof advantageously make it possible to position the internal heating surface 45 in the closed position of the device, such that the hair is gripped substantially uniformly and effectively during the treatment between the internal heating surfaces, thereby improving the straightening of the hair by the device.

The support 9 bears against a support means 140 that extends in the housing 38, allowing the support to carry out a tilting movement and, in the open position of the arms 5 and 6, keeping the support 9 in the high position.

The support means 140 may have one or more springs 141, in particular a spring as illustrated, extending between the bottom of the housing 38 and the support 9, or a leaf spring fixed in an indentation in the support 9 or in the bottom of the housing 38. The support means may, in a variant or additionally, have a protruding relief between the support 9 and the bottom of the housing 38, allowing the tilting movement and limiting the travel of the support in the housing. For example, in the example illustrated, the support means has a ball joint compressed by a spring, as is described in the patent application FR3011449.

The support 9 that is movable perpendicularly to the longitudinal axis may have a peripheral seal 33 providing sealing between the support 9 and the housing 38 while allowing the support 9 to move in the housing, as was described above. Such a seal allows in particular the sealing of the housing with respect to the steam output by one or more steam outlets, as will be described below.

The device 2 has two external surfaces, formed by external plates 13, for heating the hair to be treated, which each extend over one of the two jaws 3 and 4 towards the exterior of the device 2 in the moved-together configuration of the two jaws 3 and 4, in particular over the convex outer surface of the jaw 3 or 4, and are on opposite sides to one another on the device 2 in the moved-together configuration of the jaws 3 and 4.

Each external plate 13 is disposed on a face of the corresponding jaw 3 and 4 that faces away from the face receiving the internal plate 16 borne by the same jaw 3 or 4. In the example illustrated, the external plates 13 are made of stainless steel and the internal plates 16 are made of aluminium. However, other materials that are good conductors of heat, in particular other metals, could be used.

The external plates 13 may be metal sheets that are flexible or preformed so as to have a convex shape complementary to the external surface of the jaw 3 and 4.

The external plates 13 may be in one-piece.

The external plates 13 may be free of any projecting combing teeth.

The width of the jaw 3 at the level of external plates 13 may be smaller than the width of the other jaw 4 at the same level.

The external plates 13 may extend laterally over the entire width of the jaw 3 and 4.

The side edges of the jaw 3 may extend laterally strictly between the side edges of the other jaw 4 over the entire length of the external plates 13, in particular the side edges of the other jaw 4 faces a hollow zone of the jaw 3.

The external plates 13 are fixed to the jaw 3 or 4 by any suitable means. For example, the external plates 13 have longitudinal edges 90 that are curved inwardly and configured to each be fixed in a groove or a corresponding lateral housing 91 of the corresponding jaw 3 or 4.

The external plates 13 and the internal plates 16 are preferably elongate along the longitudinal axis Y1 or Y2 of each of the jaws 3 and 4.

The external plates 13 and the internal plates 16 are at least partially superposed on one another along an axis perpendicular to the longitudinal axis X of the device 2.

The internal plates 16 extend between the two side edges of the external plates 13.

The device 2 may, as illustrated, have a distal portion, at the opposite end from the hinge 8, which does not have a heating plate. This distal part may be domed and be wide enough to be able to be grasped by a hand, in particular while the device 2 is being used.

The internal plates 16 may be heated at a temperature greater than 50°C, better still between 90°C and 230°C.

The external plates 13 may be heated at a temperature greater than 50°C, better still between 60 and 100°C. 1

In the example illustrated, the internal plate 16 and the external plate 13 borne by the same jaw 3 or 4 are heated by thermal conduction by a single heat source 14 extending in said jaw and visible in Figure 3. However, this does not have to be the case, and the device 2 could in particular have several heat sources, respectively for the internal plates and the external plates.

In the example illustrated in Figure 3, each internal plate 16 has a first lateral edge 31 and a second lateral edge 36 opposite to the first edge 31, the edges 31 and 36 extending parallel to the longitudinal axis Y1 or Y2 of the corresponding jaw. The internal plates may be off-centre on the corresponding jaw such that the first edge 31 is closer to the adjacent lateral edge 100 of the corresponding jaw than the second edge 36 is to the adjacent lateral edge 101 of the corresponding jaw.

The internal plates 16 may protrude beyond the housing 38 laterally on both sides of the jaw and have a lateral extension defining the first lateral edge 31 that is longer in cross section of the device than the lateral extension defining the second edge 36.

As illustrated in Figure 6 for the jaw 3, the first edge 31 may be configured such that, when the spring 141 is not compressed, an angle P formed between a median plane Z of the device 2 extending between the jaws 3 and 4 in the moved-together configuration of the jaws 3 and 4 and hair under tension bearing on the first edge 31 of the internal plate 16 and on an adjacent outer surface of the jaw 3 or 4 bearing the internal plate, illustrated by the plane C, is less than or equal to 120° and strictly greater than 90°, better still equal to 105°±5°, better still equal to 105°±3°, notably at rest, for example equal to 105°.

As visible on figure 6, the device 1 comprises a groove between the first lateral edge 31 of the internal plate 16 and said adjacent outer surface of the jaw 3 or 4 bearing the internal plate 16 and that extends substantially along the longitudinal axis of the corresponding.

Said adjacent outer surface is offset from the internal plate 16 by a non-zero distance when the device 1 is viewed along its longitudinal axis.

The first lateral edge 31 extend so that it forms a protruding relief on the jaw 3 or 4.

The internal plates 16 may protrude laterally at rest from the housing 38 at the first edge 31 only by a width Ls of 1 mm. As illustrated in Figure 6, each internal plate 16 may be spaced apart, at rest, from a plane P lying laterally on the adjacent outer surface of the two jaws 3 and 4 by a distance Dp less than or equal to 6 mm, better still less than or equal to 5.5 mm.

The first edge 31 of the internal plate 16 of the jaw 3 may have an edge comer 40 configured to come into contact with hair under mechanical tension during the treatment. This hair is depicted by the plane C lying on the first edge 31 of the internal plate 16 and on an adjacent outer surface of the jaw 3. The edge comer 40 may be rounded with a radius of curvature equal to 1.5 mm.

The support 9 may protrude, at rest, from the jaw 3 or 4 in the direction of the other jaw 3 or 4 by a height Hl of at least 2 mm, for example 4 mm.

This distance makes it possible to avoid contact between the surface of the plate protmding beyond the support 9 of the plate and the surface of the jaw bordering the housing 38 facing said surface of the plate during the movement of the support 9 in the housing 38 via the spring 141.

As illustrated in the enlarged view in Figure 7, the first edge 31 having the edge comer 40 may have a second, planar part 122 that is oriented away from the jaw 4. This part 122 is parallel to the surface 45 of the internal plate 16.

The second part 122 extends, for example, from the edge comer 40 to a rib 125 of the internal plate 16, this rib 125 engaging in the seal 33 of the support 9 of the jaw 3.

Each internal plate 16 has a plurality of these ribs 125, as illustrated in Figure 8. For example, a rib 125 is formed by a curve in the internal plate 16 at its second edge 36.

The thickness Eb of the first edge 31 bearing the edge corner 40 is less than the thickness Ep of the internal plate 16, away from the various ribs 125.

As illustrated in Figure 8, each internal plate 16 has a cavity 130 configured to receive the heating element 14. This cavity 130 is formed by two parallel walls 131 extending orthogonally to the surface 45 and a wall 132 connecting the two walls 131.

For example, as illustrated in Figure 8, each wall 131 has reliefs 135 that help to keep the internal plates 16 on the support 9.

As illustrated in Figure 8, the first edge 31 of the internal plate 16 of the jaw 4 is not in contact with the support 9, unlike the second edge 36.

The first edges 31 and the second edges 36 are, for example, offset transversely from one another by a non-zero distance Db. The first edge 31 of the internal plate 16 of the jaw 4 may be curved without having a protruding edge corner.

The second edges 36 of the internal plates 16 of the jaws 3 and 4 do not extend laterally with respect to the housings 30 and are curved so as not to have a protruding edge comer.

The position and the shape of the first edges 31 and in particular of the edge comer 40 allow, during curling, an improvement in the result since it increases the bending angle of the hair and produces, on passing over the edge corner 40, an effect equivalent to that obtained by a protmding edge comer passing at a particular angle over a gift ribbon.

Moreover, the internal plates 16 protmde beyond their support 9, the first edge 31 is closer to the adjacent outer surface 32, making it possible to move closer to the roots of the hair to be treated compared with appliances of the prior art.

The radius of curvature with respect to the longitudinal axis Y1 of the external plate 13 of the jaw 3 may be smaller than that of the external plate 13 of the jaw 4 with respect to the longitudinal axis Y2.

External guiding portion

In the examples illustrated, each jaw 3 and 4 has an external hair guiding portion delimited longitudinally, on each of its two sides, by a stop surface 18 formed by a shoulder. The external hair guiding portion is defined, for example, by the external plates 13.

The stop surface 18 may comprise a flat portion, particularly in a plane transverse to the jaw, particularly flat over a width at least equal to 50% of the width of the jaw, preferably 80% of the width of the jaw, better still 100%, at the level of said stop surface 18.

The shoulders 18 may have a variable height He, for example varying between 0.5 mm on the external surface of the jaw extending laterally with respect to the internal plate 16 and 2 mm on the external surface of jaw opposite to the internal plate 16.

Each shoulder 18 may be formed by ribs delimiting the external hair guiding portion. The rib is, preferably, thicker on the opposite side from the internal plates 13 than on the sides of the internal plates 13.

Each external guiding portion is set back with respect to the base level of the jaw 3 or 4, defined as the level of the jaw 3 or 4 away from the shoulders 18. Thus, each guiding portion has a visible width h and h, illustrated in Figure 3, that is smaller than and set back from the rest of the jaw 3 or 4.

The external plates 13 may extend along the entire length of the external guiding portion.

One of the jaws may have a lateral recess 170 forming a hair guiding zone at the corresponding guiding portion. The recess 170 is delimited laterally by the stop surfaces in the proximal and distal part of the jaw delimiting the guiding portion. These stop surfaces form, at the shoulder, guiding surfaces 20 with a greater height, making it possible to keep the hair in the recess 170. The recess 170 extends laterally with respect to the jaw and faces a part of the other jaw 3 or 4. As a result, a part of the internal surface 16 of the other jaw 3 or 4 gives onto the recess 170, making it possible to have at least a part of an additional treatment member extending from the other jaw into the recess 170, in particular a comb, as will be shown below, and affords new treatment possibilities. Preferably, the recess 170 has a uniform depth along the longitudinal axis of the device X such that the outer surface of the jaw has a substantially cylindrical shape along the recess 170, meaning that it has an identical cross section along the recess 170.

On account of the presence of the recess 170, the width h of the jaw bearing the recess is smaller at said recess 170 than the width h of the other jaw facing said recess 170. The width h is between 30 mm and 50 mm and is, for example, equal to 38 mm. The width I2 is between 40 mm and 60 mm and is, for example, equal to 47 mm.

In a variant that is not illustrated, the hair guiding zone may not be a recess, specifically a zone of the jaw delimited laterally by one or two guiding surfaces in the proximal and/or distal part of the jaw.

Additional treatment member

In the examples illustrated, the device 2 has an additional hair treatment member 12 that extends from the jaw 4 towards the other jaw 3 in the moved- together configuration of the two jaws 3 and 4 and is arranged on said jaw 4 laterally with respect to the internal plate 16.

The additional treatment member is only present on the internal part of the jaw 4. The external parts of the jaws, 3 and 4 are deprived of any additional member other than the external plate 13. The member 12 extends longitudinally and parallel to the longitudinal axis Y2 along the second edge 36, opposite to the first edge 31, of the internal plate 16 of the jaw 4, being separated from this internal plate 16, when the device 2 is viewed along its longitudinal axis X.

The member 12 may have a steam outlet 21 and a comb 22, as illustrated in Figure 3.

The comb 22 may be disposed, removably, in a housing such as a longitudinal groove 35, visible in Figure 2. The user can thus change or remove the comb 22 as desired.

The groove 35 may have a rectangular cross section and open out at the distal end of the jaw 4.

The comb 22 may have, in the distal part of the device 2, an element 46 that makes it possible to grasp the comb 22 when it is being introduced into the groove 35 or extracted therefrom

The comb 22 may extend, for example, along the entire length of the guiding portion. In a variant, it could extend over only a part of the guiding portion.

The steam treatment may be ensured by virtue of a vaporization member formed by an element heating an evaporation chamber 19 supplied with water by a reservoir situated in one arm of the device, or, in a variant, by a remote reservoir. The device may have an electrically driven pump, preferably a peristaltic pump, that draws up the water to be sent to the device 2 from a reservoir of water. The pump is for example as disclosed in the publication FR 2 967 018. The evaporation chamber may be produced in accordance with the teaching in the application EP 2449909A1 or in a different way.

The evaporation chamber 19 may be disposed on one of the arms, namely the lower arm 6 in the example in question, and the steam outlet 21 is provided on the same arm 6.

The steam outlet 21 may be in the form of a strip, with a shape that is elongate in a direction parallel to the longitudinal axis Y2.

The strip may have several orifices for spraying steam, for example between 4 and 10 orifices, preferably 7, which are preferably distributed evenly along the strip and each have an axis oriented substantially perpendicularly to the median treatment plane. The vaporization member is electrically powered and a temperature sensor is advantageously disposed in the evaporation chamber 19. The device is designed to keep the temperature of the evaporation chamber at a value of between 110°C and 130°C.

The steam produced which passes out of the outlets 21 is partially contained between the steam outlet 21, the internal heating plates 16 and the other jaw 3, in particular by virtue of the presence of a containment groove 500, visible in Figure 3. This partial containment improves the application of the steam to the hair.

The comb 22 may be disposed facing the recess 170 of the other arm 5, illustrated in Figure 2, such that the end of its teeth are accommodated in the recess 170.

The comb 22 may be arranged on the jaw 4 such that the distal end 23 of the teeth of the comb is spaced apart by a non-zero distance from hair wound around the two jaws 3 and 4.

To this end, the comb 22 is configured such that, for any cross section of the device in the moved-together configuration of the jaws, for example that in Figure 4, the tangent T, which may for example fictitiously represent the hair, to the two jaws 3 and 4, extending on the side of the device bearing the comb 22, is at a distance from the comb 22.

The smallest distance Dd between the distal end 23 of the teeth of the comb 22 and the tangent T may be greater than or equal to 0.5 mm, better still greater than or equal to 1 mm, for example equal to 3 mm.

When the user winds hair around the jaws 3 and 4, in particular when curling, the hair under tension follows, between the two jaws 3 and 4, the tangent T. Thus, the wound hair does not pass through the comb 22, making the styling operation easier.

The distal end 23 of the teeth of the comb 22 is, for example, offset laterally, in the moved-together configuration of the jaws 3 and 4, from the opposite jaw 4, in this case from the jaw at the recess 170 by a distance Dde greater than or equal to 0.5 mm, preferably greater than 1 mm. This ensures that the teeth of the comb 22 cannot interfere with the jaw 4 at the recess 170.

The height Hde of the teeth of the comb 22 may be between 5 mm and 15 mm, preferably between 7 and 10 mm, for example around 8 mm.

The teeth of the comb 22 may have a rectangular cross section. In the example illustrated, the combination of the external guiding portion, of the edge corner 40 and of the heat from the external plates 13 produces high quality curling of the hair.

In addition, the device 2 may also operate as a straightener, without any loss of straightening quality compared with a conventional device dedicated only to straightening the hair.

Thermal protection cover

As illustrated in Figures 3 and 9 to 15, the device 2 has a thermal protection cover 70, for example two, made of polyamide and resistant to a temperature of at least 60°C.

Each cover 70 is mounted removably by being clip-fastened on one of the jaws 3 and 4 so as to entirely cover the corresponding external plate 13.

The cover 70 may be symmetric with respect to a longitudinal median plane.

Each cover 70 may have a recess, also referred to as a notch, 71 configured to form a preferential deformation zone 72 of the cover 70 when it is fitted on the device 2. A recess or notch is understood to be a zone in which there is less material compared with the rest of the cover, so as form a zone of mechanical weakness. This makes it possible to create a zone of elastic, localized and controlled deformation.

Each cover 70 may have a curved shape complementary to that of the corresponding external plate 13. The preferential deformation zone is thus highly advantageous here since a domed cover is known to be intrinsically more rigid than a flat cover.

Each cover 70 has for example a thickness of around 1 mm at the longitudinal edges and 1.5 mm at the centre.

Each cover 70 extends along a longitudinal axis W, said recess 71 having an elongate shape transversely to the longitudinal axis of the cover, for example forming a right angle with the longitudinal axis W.

As illustrated in Figures 9 to 11, the recess 71 is a through-recess and is symmetric with respect to a plane transverse to the longitudinal axis W of the cover 70. The recess 71 extends over at least 70% of the developed width of the cover 70. Such a recess proportion represents a very good compromise between easy fitting/removal of the cover and durability and reliability of the cover. Specifically, the cover must not tear owing to fatigue, following excessive elastic deformations. For example, as illustrated in Figure 11, the recess 71 is straight. In a variant, as illustrated in Figures 9 and 10, the recess 71 has several waves.

Each recess 71 may extend over the cover 70 at a distance from one of the longitudinal ends of the cover 70, in particular the distal end 73 of the cover 70, of less than or equal to 25% of the length Gc of the cover 70. The length Gc of the cover 70 corresponds to the length of the external treatment surface 13 of the device and, in this regard, is between 50 mm and 150 mm, preferably between 80 and 100 mm, advantageously around 88 mm. This location represents a very good compromise between easy fitting/removal of the cover and durability and reliability of the cover 70. Specifically, the cover must not tear owing to fatigue, following excessive elastic deformations.

Each cover 70 may have a gripping protrusion 75 extending from the external surface of the cover 70 at a distance of less than or equal to 25% of the length Gc of the cover 70 from the longitudinal end 74 opposite to the longitudinal end 73.

Thus, when the cover 70 is mounted on the jaw 3 or 4, the protrusion 75 is situated close to the longitudinal end of the cover 70 extending towards the half-handles 10 and 11. This makes it possible for example to detach the cover 70 with one finger of the hand holding the half-handles 10 and 11 in a single motion, thereby making handling easier.

As illustrated in Figure 9, the protrusion 75 may extend orthogonally to the cover 70 with a constant thickness and a domed outer surface.

As illustrated in Figure 10, the protrusion 75 may have a domed shape along the longitudinal axis W of the cover 70.

As illustrated in Figure 11, the protrusion 75 may be in the form of a tongue, in particular a wavy tongue, extending from the outer surface of the cover at an angle that is not a right angle.

Each cover 70 may have first protruding reliefs 77 extending at its two longitudinal ends 73 and 74 and designed to cooperate with second recessed reliefs 80 in the rest of the device 2, these being particularly illustrated in Figures 13 and 14.

The first reliefs 77 may extend parallel to, and preferably along, the longitudinal axis W of the cover 70.

Each first relief 77 has a thickness less than the thickness of the longitudinal end

73 or 74 of the cover 70. The second reliefs 80 may be in the shoulders 18 on opposite sides of the external plate 13. Thus, the first reliefs 77 on the cover extend into the shoulders 18.

As illustrated in Figure 15, the cover 70 is configured to be mounted on the device 2 by the cooperation of the first relief 77 extending at the longitudinal end 73 of the cover 70, in particular the end opposite to the protrusion 75, with the complementary second relief 80 and by the cover 70 being pivoted, on the rest of the device 2, about a pivot axis A transverse to the median plane of the cover 70.

The pivot axis A may be orthogonal to the longitudinal axis W of the cover 70 and situated at the first relief 77 on the cover 70 at the end 73 towards the recess 71.

During this operation of mounting the cover 70, the zone 72 deforms elastically towards the interior of the cover 70, allowing a slight displacement of the first relief 77 on the cover 70 towards the protrusion 75 along the longitudinal axis W of the cover 70. This deformation occurs when the user exerts a longitudinal pressure from the gripping protrusion 75. By virtue of this movement, the first relief 77 on the gripping protrusion 75 side may, during pivoting, not come to butt against the shoulder 18.

Thus, the longitudinal displacement of the first relief 77 on the cover 70, which is temporary when the user applies a longitudinal pressure, makes it possible to temporarily reduce the length of the cover, considerably facilitating its insertion into (or removal from) its housing, advantageously delimited by the stop surfaces 18.

During the pivoting of the cover 70, at least a part of the longitudinal edge 73 close to the first relief 77 bears on the shoulder 18.

Once pivoting has been completed, when the cover 70 is contact with the plate 13, the longitudinal pressure is released by the user, allowing the zone 72 to return to its initial shape by elasticity. The first relief 77 on the side of the gripping protrusion 75 then engages, during this releasing, in the second relief 80 of the shoulder 18 which faced it before the pressure was released.

The first reliefs 77 thus positioned in the second reliefs 80 make it possible to keep the cover 70 on the jaw 3 or 4. Moreover, the edges 73 and 74 are, at least partially, in contact with the shoulders 18.

To remove the cover 70, the reverse operation is carried out.

Methods To curl or straighten hair with the aid of the device 2, a lock of hair may be moved over the device 2 between the internal plates 16 and/or by passing over one external plate or the external plates 13, passing or not passing through the treatment member 12.

The hair treatment method for curling may involve the movement of the device 2 along a lock of hair from the root to the tips to carry out the following successive steps: a. A treatment of the lock of hair with the member 12, in order to comb the hair in the comb 22 and to apply steam via the outlet 21, and b. A first thermal treatment of the lock of hair by contact between the internal plates 16 of the device 2. c. A second thermal treatment of the lock of hair applying tension against the external plate 13 of the jaw 3.

Preferably, the lock of hair undergoes a change in orientation about the device 2 of at least 270° during the treatment.

At the end of step b of thermally treating the hair between the internal plates 16, the lock of hair undergoes, between the first edge 31 and the adjacent outer surface 32 of the jaw 3 around which the lock of hair is wound, a change of orientation of 100°.

At the end of step b of heating the hair on the internal plates 16, the hair is moved over the edge comer 40, making it possible to produce the abovementioned gift ribbon effect.

Another application of heat on the external plate 13 of the jaw 4 could also be carried out.

During step c, the hair is correctly contained in the external guiding portion by virtue of the recess 170 and the shoulders 18.

For this curling method, it is possible to use the end pieces 50 in order to have better handling of the device 2, without the risk of burns.

In the case of a hair treatment method for straightening, this may involve the movement of the device 2 along a lock of hair from the root to the tips to carry out the following successive steps: a. A treatment of the lock of hair with the member 12, in order to comb the hair in the comb 22 and then to apply steam via the outlet 21, and b. A first thermal treatment of the lock of hair by contact between the internal plates 16 of the device 2. In this method, the user does not need external plates 13. Therefore, before carrying out the straightening method, they can clip-fasten the covers 70 in order to protect themselves from the heat from the external plates 13.

The invention is not limited to the examples that have just been described. The device may have a cosmetic product applicator member that is or is not removable, having a porous element configured to come into contact with the hair between the jaws in the moved-together configuration of the latter.