DEVICE FOR TREATING THE HAIR

Abstract

A device for treating the hair, in particular for curling the hair, including 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 hair treatment member having at least one 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 deformation zone of the cover when it is fitted on the device.

Claims

1. A device for treating the hair, comprising: 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 hair treatment member having at least one 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.

2. The device according to claim 1, having 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, 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.

3. The device according to claim 1, wherein the or each cover covers the entire corresponding external heating surface by having a shape complementary to that of the corresponding external heating surface.

4. The device according to claim 1, wherein the cover extends along a longitudinal axis, said recess being elongate along a direction forming a non-zero angle with the longitudinal axis of the cover.

5. The device according to claim 1, wherein the cover has a gripping protrusion extending from the external surface of the cover when it is mounted on the jaw.

6. The device according to claim 1, wherein the cover and the jaw have complementary reliefs for fastening the cover to the jaw.

7. The device according to claim 1, wherein the cover is symmetric with respect to a longitudinal median plane.

8. The device according to claim 1, having on the or each jaw an external hair guiding portion delimited laterally in the proximal and/or distal part of the jaw by a stop surface.

9. The device according to claim 1, wherein the cover has a thickness of between 0.5 mm and 2 mm.

10. The device according to claim 1, having 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.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0169] 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:

[0170] FIG. 1 illustrates a perspective view of an example of a device according to the invention,

[0171] FIG. 2 illustrates a perspective view of the distal end of the device in FIG. 1,

[0172] FIG. 3 illustrates a view in cross section of an example of a device according to the invention,

[0173] FIG. 4 is an enlarged view of FIG. 3 in the region of the treatment member,

[0174] FIG. 5 illustrates a perspective and partial view of the distal end of the device in FIG. 1,

[0175] FIG. 6 is an enlarged view of FIG. 3,

[0176] FIG. 7 illustrates an enlarged view of an edge of one of the internal plates of the device in FIG. 3,

[0177] FIG. 8 illustrates, in isolation, the internal plates and the housings of the device in FIG. 3,

[0178] FIG. 9 illustrates a perspective view of an example of a thermal protection cover according to the invention,

[0179] FIG. 10 illustrates a perspective view of another example of a thermal protection cover according to the invention,

[0180] FIG. 11 illustrates a perspective view of the distal end of a device having thermal protection covers according to the invention,

[0181] FIG. 12 is a view in longitudinal section of the device in FIG. 11,

[0182] FIG. 13 illustrates a perspective enlarged view of the device in FIG. 11 in the region of a shoulder,

[0183] FIG. 14 illustrates a perspective enlarged view of the device in FIG. 11 in the region of another shoulder, and

[0184] FIG. 15 illustrates a side view of the fitting of a thermal protection cover on a device according to the invention.

DETAILED DESCRIPTION

[0185] 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.

[0186] FIGS. 1 and 2 show an example of a hair treatment device 2 according to the invention.

[0187] 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 FIG. 1.

[0188] 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.

[0189] 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.

[0190] 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.

[0191] The jaws 3 and 4 each have a convex outer surface and a substantially planar inner surface.

[0192] 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.

[0193] 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.

[0194] 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).

[0195] The device may have a water reservoir for the production of steam.

[0196] 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

[0197] 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.

[0198] 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.

[0199] 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.

[0200] 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.

[0201] 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.

[0202] 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.

[0203] 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.

[0204] 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.

[0205] 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.

[0206] 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.

[0207] 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.

[0208] 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.

[0209] 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.

[0210] 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.

[0211] The external plates 13 may be in one-piece.

[0212] The external plates 13 may be free of any projecting combing teeth.

[0213] 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.

[0214] The external plates 13 may extend laterally over the entire width of the jaw 3 and 4.

[0215] 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.

[0216] 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.

[0217] 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.

[0218] 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.

[0219] The internal plates 16 extend between the two side edges of the external plates 13.

[0220] 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.

[0221] The internal plates 16 may be heated at a temperature greater than 50 C., better still between 90 C. and 230 C.

[0222] The external plates 13 may be heated at a temperature greater than 50 C., better still between 60 and 100 C.

[0223] 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 FIG. 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.

[0224] In the example illustrated in FIG. 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.

[0225] 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.

[0226] As illustrated in FIG. 6 for the jaw 3, the first edge 31 may be configured such that, when the spring 141 is not compressed, an angle 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 1055, better still equal to 1053, notably at rest, for example equal to 105.

[0227] As visible on FIG. 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.

[0228] 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.

[0229] The first lateral edge 31 extend so that it forms a protruding relief on the jaw 3 or 4.

[0230] 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.

[0231] As illustrated in FIG. 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.

[0232] The first edge 31 of the internal plate 16 of the jaw 3 may have an edge corner 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 corner 40 may be rounded with a radius of curvature equal to 1.5 mm.

[0233] 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.

[0234] This distance makes it possible to avoid contact between the surface of the plate protruding 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.

[0235] As illustrated in the enlarged view in FIG. 7, the first edge 31 having the edge corner 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.

[0236] The second part 122 extends, for example, from the edge corner 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.

[0237] Each internal plate 16 has a plurality of these ribs 125, as illustrated in FIG. 8. For example, a rib 125 is formed by a curve in the internal plate 16 at its second edge 36.

[0238] 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.

[0239] As illustrated in FIG. 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.

[0240] For example, as illustrated in FIG. 8, each wall 131 has reliefs 135 that help to keep the internal plates 16 on the support 9.

[0241] As illustrated in FIG. 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.

[0242] The first edges 31 and the second edges 36 are, for example, offset transversely from one another by a non-zero distance Db.

[0243] The first edge 31 of the internal plate 16 of the jaw 4 may be curved without having a protruding edge corner.

[0244] 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 corner.

[0245] The position and the shape of the first edges 31 and in particular of the edge corner 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 protruding edge corner passing at a particular angle over a gift ribbon.

[0246] Moreover, the internal plates 16 protrude 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.

[0247] 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

[0248] 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.

[0249] 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.

[0250] 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.

[0251] 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.

[0252] 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 l.sub.1 and l.sub.2, illustrated in FIG. 3, that is smaller than and set back from the rest of the jaw 3 or 4.

[0253] The external plates 13 may extend along the entire length of the external guiding portion.

[0254] 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.

[0255] On account of the presence of the recess 170, the width l.sub.1 of the jaw bearing the recess is smaller at said recess 170 than the width l.sub.2 of the other jaw facing said recess 170. The width l.sub.1 is between 30 mm and 50 mm and is, for example, equal to 38 mm. The width l.sub.2 is between 40 mm and 60 mm and is, for example, equal to 47 mm.

[0256] 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

[0257] 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.

[0258] 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.

[0259] 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.

[0260] The member 12 may have a steam outlet 21 and a comb 22, as illustrated in FIG. 3.

[0261] The comb 22 may be disposed, removably, in a housing such as a longitudinal groove 35, visible in FIG. 2. The user can thus change or remove the comb 22 as desired.

[0262] The groove 35 may have a rectangular cross section and open out at the distal end of the jaw 4.

[0263] 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

[0264] 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.

[0265] 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.

[0266] 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.

[0267] 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.

[0268] 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.

[0269] 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.

[0270] 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 FIG. 3. This partial containment improves the application of the steam to the hair.

[0271] The comb 22 may be disposed facing the recess 170 of the other arm 5, illustrated in FIG. 2, such that the end of its teeth are accommodated in the recess 170.

[0272] 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.

[0273] 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 FIG. 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.

[0274] 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.

[0275] 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.

[0276] 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.

[0277] 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.

[0278] The teeth of the comb 22 may have a rectangular cross section.

[0279] 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.

[0280] 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

[0281] As illustrated in FIGS. 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.

[0282] 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.

[0283] The cover 70 may be symmetric with respect to a longitudinal median plane.

[0284] 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.

[0285] 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.

[0286] Each cover 70 has for example a thickness of around 1 mm at the longitudinal edges and 1.5 mm at the centre.

[0287] 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.

[0288] As illustrated in FIGS. 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.

[0289] For example, as illustrated in FIG. 11, the recess 71 is straight. In a variant, as illustrated in FIGS. 9 and 10, the recess 71 has several waves.

[0290] 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.

[0291] 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.

[0292] 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.

[0293] As illustrated in FIG. 9, the protrusion 75 may extend orthogonally to the cover 70 with a constant thickness and a domed outer surface.

[0294] As illustrated in FIG. 10, the protrusion 75 may have a domed shape along the longitudinal axis W of the cover 70.

[0295] As illustrated in FIG. 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.

[0296] 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 FIGS. 13 and 14.

[0297] The first reliefs 77 may extend parallel to, and preferably along, the longitudinal axis W of the cover 70.

[0298] Each first relief 77 has a thickness less than the thickness of the longitudinal end 73 or 74 of the cover 70.

[0299] 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.

[0300] As illustrated in FIG. 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.

[0301] 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.

[0302] 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.

[0303] 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.

[0304] 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.

[0305] 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.

[0306] 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.

[0307] To remove the cover 70, the reverse operation is carried out.

Methods

[0308] 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.

[0309] 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: [0310] 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 [0311] b. A first thermal treatment of the lock of hair by contact between the internal plates 16 of the device 2. [0312] c. A second thermal treatment of the lock of hair applying tension against the external plate 13 of the jaw 3.

[0313] Preferably, the lock of hair undergoes a change in orientation about the device 2 of at least 270 during the treatment.

[0314] 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.

[0315] At the end of step b of heating the hair on the internal plates 16, the hair is moved over the edge corner 40, making it possible to produce the abovementioned gift ribbon effect.

[0316] Another application of heat on the external plate 13 of the jaw 4 could also be carried out.

[0317] During step c, the hair is correctly contained in the external guiding portion by virtue of the recess 170 and the shoulders 18.

[0318] 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.

[0319] 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: [0320] 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 [0321] b. A first thermal treatment of the lock of hair by contact between the internal plates 16 of the device 2.

[0322] 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.

[0323] The invention is not limited to the examples that have just been described.

[0324] 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.