Steam treatment device for hair, notably for curling and / or straightening

Abstract

The invention relates to a device for treating hair, comprising: at least one steam outlet configured to face or come into contact with the hair, a vaporization system including a vaporization chamber in fluidic communication with the steam outlet, a liquid supply member having a fluid outlet extending inside the vaporization chamber and designed to supply liquid to the vaporization chamber in a liquid supply zone of the vaporization chamber, the liquid supply zone extending at least over the entire length of the fluid outlet of the supply member inside the vaporization chamber, a heating structure of the vaporization chamber housed in the device and overlapping the vaporization chamber in a heat exchange zone of the vaporization chamber distinct from the liquid supply zone.

Description

[0001] Description

[0002] Title: Steam treatment device for hair, notably for curling and / or straightening

[0003] The present invention relates to a device for treating hair, notably for curling and / or straightening, in particular through application of steam, and the corresponding treatment method.

[0004] Prior art

[0005] Many types of hair- styling appliances or accessories for shaping hair, notably by straightening, curling or crimping, are known, for example straightening or curling irons.

[0006] To enhance the treatment, some appliances provide for steam to be distributed towards a lock of hair or the whole head of hair. Applications WO2014064660, EP2959793, EP2765884 and EP2449911 describe for example steam treatment devices for hair comprising a liquid reservoir, and wherein one jaw comprises a vaporization system, and a system for distributing steam towards a lock of hair. A liquid, typically water or a cosmetic product for hair, is stored in the reservoir and is injected into the vaporization system comprising a chamber, through a pipe. Under the action of heating means, in contact with the vaporization chamber, the liquid changes to the vapour state and can reach the distribution system, comprising a plurality of orifices in the form of slots oriented so as to spray the steam onto a lock of hair gripped between the two treatment surfaces. However, a rapid increase in the temperature of the liquid, which may contain minerals, in the vaporization chamber can cause a gradual depositing of limescale or scale inside or at one end of the pipe, until it becomes blocked. This causes the styling appliance to malfunction and shortens the service life of the styling appliance.

[0007] International application WO2020 / 127852 describes an appliance including a vaporization chamber and a distribution chamber, the vaporization chamber being supplied with fluid by a pipe having an opening along the pipe and / or a hydrophobic layer below the injection point of the liquid into the vaporization chamber. Such features notably increase the service life of these devices by limiting obstruction of the pipe.

[0008] There is therefore still a need for a device for treating hair by at least one application of steam in which the service life is improved by limiting the scaling of the liquid supply from the steam outlet, while having a simple structure.

[0009] Disclosure of the invention The invention addresses this need with a device for treating hair, notably for curling and / or straightening hair, including:

[0010] - at least one steam outlet configured to face or come into contact with the hair,

[0011] - a vaporization system including a vaporization chamber in fluidic communication with the steam outlet,

[0012] - a liquid supply member having a fluid outlet extending inside the vaporization chamber and designed to supply liquid to the vaporization chamber in a liquid supply zone of the vaporization chamber, the liquid supply zone extending at least over the entire length of the fluid outlet of the supply member inside the vaporization chamber,

[0013] - a heating structure of the vaporization chamber housed in the device and overlapping the vaporization chamber in a heat exchange zone of the vaporization chamber distinct from the liquid supply zone.

[0014] “In fluidic communication ” means that fluid is able to flow directly or indirectly between the two.

[0015] The fact that the heat exchange zone is distinct from the liquid supply zone in the vaporization chamber means that the hottest zone in the vaporization chamber need not be in the liquid supply zone, which limits the formation of limescale in this zone and thus delays the obstruction of the liquid supply member by the limescale that would have formed in this zone. Indeed, it is generally recognized that limescale forms more rapidly in the zones subjected to greater heat exchange. The invention therefore moves the largest heat exchange zone away from the water supply zone of the vaporization chamber. This notably limits the risk of malfunction by steam stoppage and the frequency of maintenance to descale the device, which therefore reduces handling.

[0016] Preferably, the device is a device for shaping hair, notably curling and / or straightening.

[0017] Preferably, the treatment device is elongate along a main axis. In a variant, the treatment device has a different, non-elongate shape.

[0018] Preferably, the treatment device includes a handpiece having a handle and a head. The handle facilitates gripping of the device and allows additional elements to be inserted into the device, notably a user interface, a reservoir of fluid to be vaporized, and optionally a reservoir of cosmetic product. Preferably, the head includes the vaporization chamber and the heating structure. The head of the treatment device may be of any shape in cross section. Preferably, the cross section of the head of the treatment device is substantially polygonal, in particular substantially rectangular or substantially square, or substantially oval or circular. Other cross-sectional shapes are possible, such as a cross section with a polygonal outline on one side and a non-polygonal, notably rounded, for example circular, outline on the other side. Preferably, the head of the device has a generally flattened shape in cross section.

[0019] Preferably, the device, notably the head of the device, includes a hair-treatment soleplate configured to come into contact with or to face the hair and having the steam outlet. Preferably, said treatment soleplate includes a base having a substantially planar or substantially outwardly convex external surface. Preferably, said treatment soleplate has, when viewed from the front, a substantially polygonal, notably rectangular or square, outline, but can also be circular or oval.

[0020] The device may include a reservoir of fluid to be vaporized incorporated into the handpiece, notably into the handle thereof as mentioned above. In a variant, the device includes a base in fluidic communication with the handpiece, notably with the handle thereof, into which the reservoir of fluid to be vaporized is incorporated. In another variant, the device is connected, notably by the handle thereof, to an external liquid supply, notably to an external water outlet.

[0021] Preferably, the device is a hair straightening and / or curling device.

[0022] The device may include at least one treatment surface configured to come into contact with or face a portion of the lock of hair.

[0023] The device may include two jaws arranged to face each other and articulated together between a closed treatment configuration and an open configuration in which the hair is engaged between the jaws. At least one of the jaws includes an internal treatment member, defining notably the treatment soleplate, including an internal treatment surface configured to come into contact with or face a portion of the lock of hair in the closed configuration.

[0024] The treatment surface may be a heat treatment surface, the treatment member being notably a heating plate facing the other jaw.

[0025] At least one of the jaws may include the vaporization chamber and the heating structure. Preferably, the other jaw has no steam outlet and no steam chamber.

[0026] The jaws can each be held by an arm, the two arms being connected to each other, notably by an articulation at one end thereof, in order to adopt the closed or open configuration of the jaws. The two arms can each include a half-handle on the articulation side and one of the jaws on the free-end side.

[0027] Preferably, the fluid to be vaporized is water, preferably water that is not demineralized, and not distilled.

[0028] Supply member

[0029] The supply member for the fluid to be vaporized may be connected to a reservoir containing liquid, notably water.

[0030] Preferably, the supply member is a liquid supply conduit that extends partially inside the vaporization chamber and is designed to define a supply zone in the vaporization chamber, in which supply zone the conduit extends.

[0031] The vaporization chamber may extend along a main axis, notably a longitudinal axis, the supply member, notably the conduit, extending partially inside the vaporization chamber at least partially along the main axis.

[0032] The supply member, notably the supply conduit, may have a free end forming an injection point for injecting the liquid into the vaporization chamber.

[0033] Additionally or alternatively, the side wall of the supply member, notably of the supply conduit, may be at least partially open from a free end, the lateral opening notably having a shape that allows the liquid from the reservoir to flow into the vaporization chamber in the event of accumulation and depositing of limescale at the free end of the supply member, notably of the supply conduit. This limits the obstruction of the supply member by allowing the liquid to flow into the vaporization chamber through a lateral opening.

[0034] The opening may include at least one slot extending along an axis substantially parallel to the supply member, notably to the supply conduit, preferably at least two slots extending on either side of the supply member, notably of the supply conduit, the at least two slots forming a plane preferably extending parallel to the internal surface of the vaporization chamber.

[0035] The opening may be a cut-out over a half-section of the supply member, notably of the supply conduit, extending along an axis substantially parallel to the supply member, notably to the supply conduit, and preferably the supply member, notably the supply conduit, is arranged in the vaporization chamber such that the cut-out is on the side opposite to the surface of the vaporization chamber heated by the heating structure.

[0036] The free end of the supply conduit may be bevelled.

[0037] A ratio between a height of the vaporization chamber and an internal diameter of the supply conduit may be between 0.55 and 0.75.

[0038] Liquid supply zone and heat exchange zone

[0039] Preferably, the vaporization chamber extends along a main axis, notably a longitudinal axis.

[0040] The heat exchange zone and the liquid supply zone may be separated along the main axis of the vaporization chamber.

[0041] Preferably, the liquid supply zone extends inside the vaporization chamber over the entire length of the supply member in the vaporization chamber, notably from a wall delimiting the vaporization chamber including an inlet to a free end of the supply member, notably of the supply conduit.

[0042] The heat exchange zone may correspond exactly to the zone overlapping the heating structure.

[0043] The heat exchange zone may extend over less than 80%, preferably less than 70%, even more preferably less than 60% of the length of the vaporization chamber.

[0044] The heat exchange zone may extend over a length of between 20% and 80% of the length of the vaporization chamber.

[0045] Preferably, the heat exchange zone is spaced apart from the supply zone by a non-zero distance along the main axis of the vaporization chamber that is notably greater than or equal to 5% of the length of the vaporization chamber, preferably greater than or equal to 10% of the length of the vaporization chamber along the main axis.

[0046] Vaporization chamber

[0047] Preferably, the vaporization chamber extends along a main axis, notably a longitudinal axis, parallel to the main axis of the device.

[0048] Preferably, there is a single vaporization chamber in the device.

[0049] Preferably, the vaporization chamber consists of a single cavity in the device.

[0050] The vaporization chamber may be delimited by a hollow body. The hollow body may be in several parts, notably a cavity body forming the cavity of the vaporization chamber and a closing wall of the cavity extending notably between the cavity body and the treatment surface. The cavity body may be a one-piece part. In a variant, the hollow body is a one- piece part.

[0051] The vaporization chamber may have no elements for absorbing the liquid to be vaporized. This makes the device easier to manufacture and more lightweight. It is thus easier to handle and, in the case of a brush, makes it possible to brush the hair in several directions. The vaporization of the water is also facilitated and the formation of scale limited.

[0052] Preferably, the vaporization chamber includes a first vaporization volume and a second vaporization volume in fluidic communication with the first vaporization volume, the supply member extending inside the first volume. The first and second vaporization volumes are joined by a passage having a cross section smaller than at least one cross section of the first vaporization volume. The presence of two vaporization volumes separated from one another by a reduction in cross section makes it possible to limit the passage of liquid water from the first vaporization volume to the second vaporization volume, and to hold back any particles of limescale that may form in the first vaporization volume. The first and second vaporization volumes may be of identical width and longitudinally continuous along the main axis of the vaporization chamber. The passage of reduced cross section may be formed by a relief projecting from one of the walls, notably the upper or lower wall.

[0053] The volume of the vaporization chamber may be between 3000 mm3and 20 000 mm3. The second vaporization volume may have a volume greater than or equal to 5%, preferably greater than or equal to 8%, and more preferably greater than or equal to 10% of the total volume of the vaporization chamber. Such a vaporization chamber can hold enough steam to ensure efficient treatment of the hair while keeping the device sufficiently compact and lightweight.

[0054] The heat exchange zone may overlap the first and second volumes of the vaporization chamber. The heat exchange zone may extend through substantially all of the second volume and in a portion of the first volume.

[0055] The vaporization chamber can be devoid of cavities for receiving the heating structure.

[0056] Heating structure

[0057] Preferably, the heating structure is disposed on the device outside of the vaporization chamber. The heating structure can be external to the hollow body of the vaporization chamber.

[0058] The heating structure may include a flat surface in contact with an external surface of the hollow body of the vaporization chamber.

[0059] Preferably, the heating structure is made up of one or more heating elements designed to heat an upper or lower wall delimiting the vaporization chamber, notably by being in contact or via a heat transmission element or layer, notably a thermal paste.

[0060] The heating element or elements may extend between the vaporization chamber and the treatment surface, notably the internal surface of the jaw carrying said heating element, said jaw preferably including an internal heating plate. Thus, the heating element or elements simultaneously heat the treatment surface and the vaporization chamber. In a variant, the heating element or elements are in contact with the wall of the vaporization chamber opposite the treatment surface. In another variant, the heating structure includes at least two heating elements on either side of the vaporization chamber.

[0061] Preferably, the heating structure overlaps the vaporization chamber without projecting beyond the vaporization chamber.

[0062] The heating element or elements of the heating structure may be positive temperature coefficient (PTC) heaters or ceramic heaters, notably metal ceramic heaters (MCH).

[0063] Preferably, the heating structure is configured to heat the vaporization chamber such that, during use, notably as the liquid is entering the vaporization chamber, the temperature in the heat exchange zone is always greater than or equal to the vaporization temperature of the fluid to be vaporized. The heating structure may be configured to heat the heat exchange zone to a temperature of between 100°C and 200°C, preferably to a temperature of between 110°C and 180°C.

[0064] The heating element or elements may have electrical power greater than or equal to 50 W, or even 100 W, 200 W or 500 W. In particular, the heating power of the heating elements is selected so that, taking into account the incoming liquid flow rate and the temperature of the liquid, all of the liquid is continuously vaporized in the vaporization chamber as it arrives.

[0065] Device The device may include a single steam outlet, which is notably elongate and extends parallel to the main axis of the device and / or of the vaporization chamber. In a variant, the device includes a plurality of steam outlets extending along at least one row of steam outlets extending parallel to the main axis of the device and / or of the vaporization chamber.

[0066] The vaporization system may include a steam distribution chamber distinct from the vaporization chamber, which is in fluidic communication with the vaporization chamber and which supplies steam to the steam outlet or outlets, the steam outlet or outlets opening directly into the distribution chamber.

[0067] Preferably, there is a single distribution chamber in the device.

[0068] The vaporization chamber and the distribution chamber may form a block, the heating element being disposed on the device outside from said block.

[0069] The distribution chamber may extend beside the vaporization chamber. The vaporization chamber and the distribution chamber may have planes of extension that are parallel to each other.

[0070] In a variant, the device may include several distribution chambers parallel to one another and in fluidic communication with the vaporization chamber, each supplying steam to at least one steam outlet.

[0071] Preferably, the distribution chamber includes an elongated hollow body forming a steam distribution rail, the hollow body including a steam inlet, preferably at one of the ends thereof, in fluidic communication with the vaporization chamber, notably at the end thereof opposite the supply member.

[0072] The body of the distribution chamber may include a partition wall common to the body of the vaporization chamber. Said wall of the vaporization chamber may constitute a side wall of the distribution chamber, the two chambers being connected to one another by an opening in said wall.

[0073] The body of the vaporization chamber and / or of the distribution chamber may be made from a thermally conductive material, notably from metal. Preferably, the thermally conductive material has a thermal conductivity greater than 10 Wm^K'1, preferably greater than 50 Wnr'K’1, and more preferably greater than 100 Wnr'K’1.

[0074] Preferably, the heating structure does not overlap the distribution chamber. The vaporization chamber may include an internal surface covered at least in part by a hydrophobic layer positioned at least in the liquid supply zone. The hydrophobic layer may include polytetrafluoroethylene (PTFE) and may be positioned only below in the liquid supply zone, notably only at the free end of the conduit and over a surface area of between 10 mm2and 2000 mm2, preferably between 100 mm2and 1000 mm2, and more preferably between 500 mm2and 600 mm2, for example 552 mm2.

[0075] Preferably, the device, notably the handpiece, includes a member for detecting the configuration of the jaws to detect whether the jaws are in the closed treatment configuration or the open configuration, notably a proximity sensor or a Hall-effect sensor.

[0076] The detection member may be arranged between the two arms at the halfhandles.

[0077] The device may include a system for supplying the vaporization chamber with liquid, notably a pump. The supply system may be configured to supply the vaporization chamber depending on the temperature of said vaporization chamber and / or depending on the time elapsed since the device was started up and / or depending on the configuration of the jaws. The supply system may be configured to supply the vaporization chamber only when the temperature of the chamber is above a predefined temperature threshold and / or when the time elapsed since the device was started up is greater than or equal to a predetermined time, corresponding notably to the time taken for the vaporization chamber to reach a predefined temperature threshold. The temperature of the vaporization chamber may be measured using a sensor positioned therein or at the interface between the heating structure and the vaporization chamber.

[0078] Controlling the intake of water as a function of temperature limits the risk of applying liquid water instead of steam.

[0079] The supply system for the vaporization chamber may be configured to supply the vaporization chamber only when the jaws are in the closed configuration. The supply system may be configured to be activated only if the member for detecting the configuration of the jaws detects that the jaws are in the closed configuration, or to be inhibited if the member for detecting the configuration of the jaws detects that the jaws are in the open configuration.

[0080] Preferably, the supply system is configured to operate at a constant predetermined flow rate. The device may include a steam control member configured to control whether steam is applied to the hair or not. For example, the steam control member may control the intake of water into the vaporization chamber. When the user wishes to apply steam to their hair, they can actuate the steam control member which then for example commands a pump connected to the reservoir to bring liquid into the vaporization chamber. As explained above, this liquid can be supplied to the vaporization chamber depending on certain additional conditions as described above, notably a given temperature of the chamber, after a given time since switching on and / or depending on the configuration of the jaws. The control member may be controlled by the user via a selector, for example a button with two or three positions.

[0081] The device according to the invention may include an electrical power supply. For example, electrical power is supplied by means of accumulators and / or batteries and / or by means of an electrical cable connected to a mains socket or to a mains adapter.

[0082] The electrical power supply may notably be used to supply power to the heating structure, directly or indirectly via a control circuit.

[0083] The body of the vaporization chamber may be removably mounted on the device. The same may be true for the heating plate if it is present on the same jaw and / or for the heating structure. They may be removed successively or together form a block that can be removed directly. This facilitates maintenance of the device.

[0084] Treatment method

[0085] According to another aspect thereof, the invention also relates to a method for treating hair using a device as described above, including applying steam to the hair via the steam outlet or outlets.

[0086] Preferably, the total steam flow from the steam outlet or outlets may be substantially constant as long as the vaporization chamber is supplied with liquid.

[0087] Preferably, the method is a hair straightening or curling treatment.

[0088] Preferably, the temperature during application of the steam is higher in the heat exchange zone than in the supply zone. The temperature in the heat exchange zone may be greater than or equal to the vaporization temperature of the liquid and the temperature in the supply zone may be lower than the vaporization temperature of the liquid.

[0089] The features of the device described above apply to the method in combination or separately from each other. Preferably, the method includes detecting the configuration of the jaws, and the steam is applied depending on the configuration of the jaws, steam application notably being activated only when the jaws are in the closed configuration.

[0090] The method may be repeated several times in order to completely treat some or all the hair.

[0091] The method may include one or more steps of rinsing the hair.

[0092] The method may include at least one step of applying a cosmetic product to the lock of hair before or after using the device according to the invention, in particular a brush, and preferably before.

[0093] The cosmetic product may be a composition for cleaning, dyeing, bleaching, conditioning or shaping the hair. Preferably, the cosmetic product is a hair shaping composition, notably a composition for curling, setting or, preferably, relaxing or straightening hair.

[0094] The cosmetic products that may be used according to the method of the invention may be liquids, gels, milks or creams in the form of single emulsions (O / W or W / O) or multiple emulsions, or solids.

[0095] The cosmetic product may contain one or more active agents selected from reducing agents and, in particular, thiols, oxidizing agents and, in particular, hydrogen peroxide or persalts such as persulfates, colouring agents and, in particular, pigments, direct dyes or oxidation dyes, temporary shaping agents and, in particular, styling polymers that are preferably anionic, amphoteric or non-ionic, conditioning agents and, in particular, silicones, mineral or plant oils, plant waxes, cationic surfactants or cationic polymers, alkaline agents or acids. Even more preferably, the cosmetic product contains one or more agents selected from oxidizing agents, reducing agents or alkaline agents of the hydroxide type.

[0096] Brief description of the drawings

[0097] Other features, objectives and advantages of the invention are set out in the detailed description below and in the attached drawings, given by way of non-limiting example, in which:

[0098] [Fig. 1] is an overview of a hair treatment device as described in the present invention, [Fig. 2] is a perspective view of a vaporization system according to an embodiment of the present invention,

[0099] [Fig. 3] is a top view of the vaporization system according to the embodiment in Figure 2, with the heating structure extending under the vaporization system shown using dotted lines,

[0100] [Fig. 4] shows the vaporization system shown in Figure 3 in cross section along the axis A-A, in use with no limescale in the vaporization chamber,

[0101] [Fig. 5] shows the vaporization system shown in Figure 3 in cross section along the axis A-A, in use after a given usage time, and

[0102] [Fig. 6] shows a variant vaporization system in cross section, in use after a given usage time.

[0103] Detailed description

[0104] Throughout the remainder of the description, elements that are identical or have identical functions bear the same reference signs. For the sake of the conciseness of the present description, they are not described for each of the figures, with only the differences between the embodiments being described.

[0105] For the sake of clarity, the figures do not always show the actual proportions.

[0106] Figure 1 is an exploded perspective view of a treatment device 1, notably for shaping hair, in particular for straightening, using steam to shape the hair.

[0107] The device 1 illustrated is a hair straightener. However, the invention is not limited to such a device. A person skilled in the art could easily apply the invention to a different shaping device, notably to a curling or brushing device.

[0108] In the example illustrated, the device includes a first arm 2 and a second arm 3 articulated together by means of a hinge 20. The two arms 2 and 3 each include a proximal part in the form of a half-handle including the articulation and a distal part forming respectively a first jaw 5 and a second jaw 6 facing each other. The maximum opening angle (not illustrated) between the first arm and the second arm is between 5° and 60°, preferably between 10° and 20°, and more preferably approximately 15°. The jaws 5 and 6 can assume an open configuration corresponding to the maximum opening angle and a closed treatment configuration. The articulation 20 may include an elastic member for holding the jaws 5 and 6 in the open configuration when at rest. The user must therefore mechanically bring the jaws together to adopt the closed configuration and treat the hair. A first treatment surface, not shown, is carried by the first jaw 5 and a second treatment surface 4 is carried by the second jaw 6, the first surface and the second surface being intended to grip a lock of hair between them when the jaws 5 and 6 are in the closed configuration.

[0109] The first treatment surface and the second treatment surface 4 are generally complementary surfaces. They may have different shapes depending on the intended use of the styling appliance 1, and are preferably interchangeable. Typically, the treatment surfaces are flat where the treatment device 1 is used as a straightening appliance, or curved (not shown) where used as a curling appliance, or wavy (not illustrated) where used as a crimping appliance. A curling appliance is for example described in document EP0619087. The treatment surfaces may also be uneven, i.e. include a plurality of protuberances such as, for example, teeth or spikes (not illustrated).

[0110] The steam treatment device also comprises a liquid reservoir, typically a water reservoir (not shown in Figure 1), or a reservoir containing a cosmetic agent, which may be embedded in one of the jaws, or which may alternatively be arranged at a distance from the appliance in a so-called remote base, as provided for in document EP3025610.

[0111] As illustrated in Figures 2 and 3, the liquid reservoir is in fluidic communication with a liquid vaporization system 7 via a supply conduit 74. Advantageously, the liquid reservoir is incorporated into the jaw comprising the liquid vaporization system 7.

[0112] The vaporization system 7 comprises at least one vaporization chamber 71 occupying a continuous volume in which vaporization takes place, i.e. a defined uninterrupted volume. The vaporization chamber 71 may be substantially parallelepipedic, and for example have a rectangular, square or trapezoidal cross section. This provides a good compromise between the compactness and the efficiency of the vaporization system.

[0113] The vaporization chamber 71 for example extends along a main axis X parallel to a longitudinal axis L of the device.

[0114] A free end of the supply conduit 74 forms an injection point 75 in the main vaporization chamber 71 in a liquid supply zone Zi, illustrated in Figure 3. Preferably, the supply conduit 74 projects into the vaporization chamber 71, and the liquid contained in the reservoir can be injected into the main vaporization chamber 71 from this injection point. The supply conduit 74 is therefore distinct from the vaporization chamber 71, i.e. it is not the same part. Typically, the liquid contained in the reservoir is water, or a cosmetic product. As illustrated, the liquid supply zone Zi extends inside the vaporization chamber 71 over the entire length of the supply conduit 74 which projects into the vaporization chamber 71 between a wall 100 of the vaporization chamber behind the supply conduit 74 and including an inlet 101 of the supply conduit 74 to the free end 75 of the supply conduit 74.

[0115] In this example, the liquid supply zone Zi extends over a length Li along the main axis X that is less than 50% of the length V of the vaporization system 7. The supply conduit 74 also extends over a length along the main axis X that is less than 50% of the length V of the vaporization system 7. This is advantageous in that it ensures that the zone in which vaporization is most effective is large enough to vaporize all of the liquid. However, it could be otherwise, notably in the case of a longer supply conduit 74.

[0116] The hair-styling appliance further comprises a steam distribution system 7' which is in communication with the vaporization system 7 and includes one or more orifices 77 for distributing steam towards a lock of hair. The distribution system 7' may for example comprise a distribution chamber 76 in vapour communication with the vaporization chamber 71, and in which the at least one steam distribution orifice 77 is arranged. The distribution chamber 76 may extend beside the vaporization system 7, preferably over substantially the entire length of the vaporization system 7. This provides a compromise between the compactness and the efficiency of the vaporization system 7 and the distribution system 7'.

[0117] The vaporization chamber 71 is preferably a compartment heated by a heating structure 8, for example a heating means 8 arranged in contact with the vaporization chamber 71, enabling the liquid injected into the vaporization chamber 71 to be vaporized, independently of the heating of other components of the hair- styling appliance 1.

[0118] The heating structure 8 may for example be positioned under the vaporization system 7 as shown in the exploded view in Figure 1.

[0119] The heating structure 8 may be arranged against the largest external surface of the vaporization system 7, preferably placed opposite the distribution orifices 77, and may extend so as to be pressed at least partially against lateral surfaces of the vaporization system 7.

[0120] As illustrated, the heating structure 8 is separated, along the main axis X, from the supply conduit 74, notably from the end 75 of the supply conduit in the vaporization chamber. This enables the heating structure 8 to form, in the vaporization chamber 71, a heat exchange zone Zc directly opposite the heating structure through the bottom wall of the vaporization chamber. This heat exchange zone Zc is distinct and separated from the liquid supply zone Zi.

[0121] For example, the heat exchange zone Zc is spaced apart from the supply zone by a distance Dz along the main axis X of the vaporization chamber 71 that is greater than 5% of the length V of the vaporization chamber 71.

[0122] The heat exchange zone Zc extends, in this example, along the main axis X over a length Lc of less than 60% of the length V of the vaporization system 7.

[0123] In general, vaporization takes place in the vaporization system 7 and in the steam distribution system 7'.

[0124] Preferably, the vaporization system 7 has a maximum external volume of 110x35x12.5 mm, and has an internal volume sufficient for storing the limescale contained in at least 35 litres of hard water of hardness 28°f. The heating structure 8 is for example designed to vaporize water in a sequence of 10 seconds continuously and 10 seconds of rest with a flow rate of around 1 g / min ± 0.5 g / min.

[0125] The vaporization system 7 may include a body 10 delimiting the vaporization chamber 71 and the distribution chamber 76. The body 10 may be made of a metal, an alloy or any heat-conducting material. Typically, the body of the vaporization chamber 10 is made of aluminium and may be made by moulding or extrusion.

[0126] The body 10 may comprise several parts, notably at least one cover 12. According to the exploded view shown in Figure 1, the vaporization system 7 comprises a first part that comprises the vaporization chamber 71 and is pressed against the heating structure 8, on which is placed a second part, in this case a cover 12, comprising orifices that are connected to the steam distribution orifices 77. Preferably, the various parts are sealed, for example by a silicone gasket.

[0127] Advantageously, a leaf spring enables the heating structure 8 to be compressed by the vaporization system 7, to guarantee permanent contact and optimum operation.

[0128] The heating structure 8 may typically be a positive temperature coefficient (PTC) heater or ceramic heater, but more generally any system enabling the vaporization chamber 71 to be heated in accordance with the intended purpose. The heating structure 8 may be regulated by a thermistor, for example a negative temperature coefficient (NTC) thermistor, operating as a temperature sensor, preferably arranged above the injection point. The thermistor can make the hair-styling appliance 1 safer by inhibiting the injection of liquid under specific conditions, for example depending on the temperature of the heating structure 8. Typically, a lower temperature limit is approximately 95°C and an upper temperature limit is approximately 130°C, or, in a reduced temperature range, a lower temperature limit is 105 °C and an upper temperature limit is 120°C or even 110°C.

[0129] Advantageously, the supply conduit 74 is centred on the longitudinal axis X of the vaporization chamber 71. The end of the supply conduit 75 forming the injection point is arranged substantially at the first third of the length of the vaporization chamber 71 along the main axis X.

[0130] It is beneficial to move the injection point away from the steam distribution means 7' to limit the risk of ejecting hot water that has not had time to vaporize. Preferably, the supply conduit 74 has an external wall at least 1 mm away from the internal wall of the vaporization chamber 71, and the height of the vaporization chamber is greater than 8 mm, in order to limit limescale deposits from the free end 75 of the supply conduit 74 and therefore premature blocking.

[0131] The supply conduit 74 may be made of a material comprising or coated with a material to which the limescale adheres poorly, so as to limit limescale deposits. Typically, the material chosen may be polytetrafluoroethylene (PTFE, also known under the registered trademark Teflon®) which has the advantage of having excellent non-stick properties while being very heat resistant. Preferably, at least one internal wall of the supply conduit 74 is coated with PTFE, thereby making the supply conduit 74 resistant to high temperatures, notably above 300°C, and have an internal wall with a very low coefficient of friction, which limits limescale deposits on the internal wall of the supply conduit 74.

[0132] The supply conduit 74 preferably has a large internal cross section to prevent premature blocking of the free end 75 of the supply conduit 74 for example. The internal cross section may typically have a diameter greater than 3 mm, preferably greater than 4 mm. In order to limit the transfer of heat from the walls of the vaporization chamber 71 to the liquid, the wall of the supply conduit 74 may advantageously be more than 1 mm thick. A ring with an internal cross section of 6 mm and an external cross section of 7 mm made of polyphenylene sulfide (PPS) may be attached to the supply conduit 74 to limit the heat transfer to the internal wall of the supply conduit 74.

[0133] Preferably, a ratio between the height of the vaporization chamber 71 and the diameter of the internal cross section of the supply conduit 74 is between 0.55 and 0.75, typically, the ratio is about 0.6 for a height of 4.9 mm and an internal diameter of 3 mm. Indeed, these dimensions have been optimized to guarantee the best possible resistance to scaling while limiting the dimensions of the various components.

[0134] Advantageously, the portion forming the free end 75 of the supply conduit 74 may have a specific shape allowing any accumulation of limescale to be concentrated in a specific zone, while providing a zone where the liquid can continue to enter the vaporization chamber 71 without being hindered by the accumulation of limescale.

[0135] For example, the free end 75 of the supply conduit 74, which free end forms the injection point, is bevelled, as illustrated in Figure 4. Alternatively or additionally, the supply conduit 74 may comprise an opening extending substantially along the supply conduit from the free end 75 forming the injection point. The opening is shaped to allow the liquid coming from the reservoir to flow into the vaporization chamber 71 even in the event of accumulation and depositing of limescale at the free end 75 of the supply conduit 74.

[0136] In an example embodiment, the opening in the supply conduit 74 is a cut-out over a half-section of the supply conduit 74, extending along an axis substantially parallel to the supply conduit 74. In the example embodiment illustrated in Figures 2 to 5, the supply conduit 74 is arranged in the vaporization chamber 71 so that the cut-out is on the side opposite to the wall forming the bottom of the vaporization chamber 71. Typically, in an example embodiment where the vaporization chamber 71 is closed by a plate forming a cover 12, this means that the cut-out in the supply conduit 74 is then oriented towards the plate forming the cover 12.

[0137] According to a preferred but not obligatory example embodiment, the internal surface of the vaporization chamber 71 is covered at least in part by a hydrophobic layer 9, notably made of polytetrafluoroethylene (PTFE), positioned at least under the injection point on the bottom surface of the body 10, which surface is closest to the water outlet. The hydrophobic layer 9 is used to limit evaporation below the injection point on the surface closest to the outlet in order to move it further into the evaporation chamber 71, thereby limiting the depositing of limescale closer to the injection point. In one example embodiment, the optional hydrophobic layer 9 is formed by applying a hydrophobic material to a localized zone of the bottom of the body 10. Typically, the hydrophobic material can be applied like paint or a coating or sprayed onto the internal surface of the vaporization chamber 71.

[0138] Advantageously, the hydrophobic layer 9 is an attached element inside the vaporization chamber 71. The attached element may be held in position in the vaporization chamber 71 by an immobilization device comprising an element 710 for centring the attached element with respect to the injection point.

[0139] In the example vaporization chamber 71 illustrated in Figures 2 and 3, the centring element 710 comprises a centring half-pin 710a formed in the vaporization chamber 71 and intended to cooperate with a notch 9a of complementary shape formed in the attached element 9.

[0140] Advantageously, but not obligatorily, and as shown notably in Figures 2 and 3, the liquid vaporization system 7 may include a first vaporization volume 71 and a second vaporization volume 72, preferably separated from each other by a wall 121 forming a passage between the two volumes 71 and 72 that has a cross section smaller than the cross section of at least the first volume 71. The first vaporization chamber 71 is then arranged upstream of the second vaporization chamber 72 in the flow direction of the steam. Preferably, the hydrophobic layer 9 extends inside the first volume 71. The heat exchange zone Zc preferably overlaps the two volumes 71 and 72 and the liquid supply zone Zi preferably extends only inside the first volume 71. The wall 121 can then constitute a barrier to limescale moving into the second volume 72.

[0141] Preferably, the second volume 72 comprises discontinuities or obstacles due to the presence of chicanes 73 to create a labyrinth path for the steam.

[0142] Chicane 73 means any obstacle or barrier placed in the chamber to cause the steam to move irregularly, for example in a zigzag manner, reducing the flow speed in the secondary vaporization chamber 72, and increasing contact with the surfaces of the various walls of the chamber 72. This vaporizes any drops of liquid, thereby ensuring the total vaporization of the liquid, the heat exchange surface being increased by the presence of the chicanes 73. The chicanes 73 may for example be distributed parallel to one another. This allows the steam to flow along a regular geometry, and therefore to trap limescale uniformly in the second vaporization chamber 72. Preferably, the first volume 71 is larger than the second volume 72, even at least twice as large, so as to enable rapid vaporization in the first volume without reducing the compactness of the vaporization system 7.

[0143] In this embodiment, the optional distribution chamber 76 may be arranged beside the vaporization chamber 71 and the secondary vaporization chamber 72, preferably over substantially the entire length of the vaporization system 7.

[0144] Such an arrangement and the corresponding operation are described in detail in document EP2591698.

[0145] Specific example embodiments schematically representing the vaporization system 7 during operation without the cover 12 are illustrated schematically in Figures 4 to 6 in order to illustrate the advantages of the features described above.

[0146] In a first example embodiment shown in Figures 4 and 5, the supply conduit 74 comprises an opening with a cut-out over a half-section, and the internal surface of the vaporization chamber 71 is covered with a hydrophobic layer 9 covering the bottom of the body 10. In operation, according to Figure 4, at a first instant Tl, typically during a first use of the styling appliance 1, the liquid 110 coming from the reservoir is injected into the vaporization chamber 71 via the supply conduit 74, from the free end 75 forming an initial injection point 11.

[0147] The injected water comes into contact with the hydrophobic layer 9 in the liquid supply zone, which does not overlap the heating element 8 and is therefore less heated, before flowing, still in the liquid state, towards the heating zone Zc. The temperature in the heat exchange zone Zc is greater than or equal to the vaporization temperature of the liquid and the temperature in the supply zone Zi is preferably lower than the vaporization temperature of the liquid. In the heating zone Zc, at a vaporization point remote from the initial injection point 11 and from the liquid supply zone Zi, it is vaporized by a rapid increase in temperature.

[0148] This steam then passes into the distribution chamber 76 and is then conveyed towards the hair through the orifices 77, for example at a constant flow rate.

[0149] According to Figure 5, at an instant T2 after Tl, for example after more than 10 L of hard water, typically of hardness 28 °f, has been injected into the vaporization chamber 71, a progressive accumulation 120 of scale or limescale occurs in the heating zone Zc, for example on a wall 121 at the inlet of the secondary vaporization chamber 72. The separation of the heating zone Zc and the liquid supply zone Zi thus limits the formation of limescale in the liquid supply zone Zi, thereby delaying the obstruction of the supply conduit 74 by the limescale which would have formed in this zone.

[0150] In the examples described above, the supply conduit 74 includes an opening with a cut-out over a half-section. However, the invention is not limited to such a supply conduit. As illustrated in Figure 6, the supply conduit 74 may be a simple cylindrical conduit without a cut-out and with an open end. The opening may be straight, as illustrated, or bevelled.

[0151] As the reader will have appreciated, numerous modifications may be made without materially moving away from the novel teachings and advantages described herein. Therefore, all modifications of this type are intended to be included within the scope of the disclosed hair-styling appliance.

Claims

Claims1. Device (1) for treating hair, notably for curling and / or straightening hair, including: at least one steam outlet (77) configured to face or come into contact with the hair, a vaporization system (7) including a vaporization chamber (71) in fluidic communication with the steam outlet (77), a liquid supply member (74) having a fluid outlet extending inside the vaporization chamber (71) and designed to supply liquid to the vaporization chamber (71) in a liquid supply zone (Zi) of the vaporization chamber (71), the liquid supply zone (Zi) extending at least over the entire length of the fluid outlet of the supply member (74) inside the vaporization chamber (71), a heating structure (8) of the vaporization chamber (71) housed in the device (1) and overlapping the vaporization chamber (71) in a heat exchange zone (Zc) of the vaporization chamber (71) distinct from the liquid supply zone (Zi).

2. Device (1) according to Claim 1, wherein the vaporization chamber (71) extends along a main axis (X), notably a longitudinal axis, the supply member (74) extending partially inside the vaporization chamber (71) at least partially along the main axis (X).

3. Device (1) according to Claim 1 or 2, the liquid supply zone (Zi) extending inside the vaporization chamber (71) over the entire length of the supply member (74) in the vaporization chamber and the heat exchange zone (Zc) corresponding exactly to the zone overlapping the heating structure (8).

4. Device (1) according to any one of the preceding claims, wherein the heat exchange zone (Zc) extends over less than 80%, preferably less than 70%, even more preferably less than 60% of the length (V) of the vaporization chamber (71).

5. Device (1) according to any one of the preceding claims, wherein the side wall of the supply member (74) is at least partially open from a free end (75).

6. Device (1) according to any one of the preceding claims, wherein the vaporization chamber (71) extends along a main axis (X), notably a longitudinal axis, andthe heat exchange zone (Zc) and the liquid supply zone (Zi) are separated along the main axis (X) of the vaporization chamber (71).

7. Device (1) according to any one of the preceding claims, wherein the vaporization chamber (71) extends along a main axis (X), notably a longitudinal axis, the heat exchange zone (Zc) being spaced apart from the supply zone (Zi) by a non-zero distance (Dz) along the main axis (X) of the vaporization chamber (71) that is notably greater than or equal to 5% of the length (L) of the vaporization chamber (71), preferably greater than or equal to 10% of the length (L) of the vaporization chamber (71) along the main axis (X).

8. Device (1) according to any one of the preceding claims, wherein the vaporization chamber (71) includes a first vaporization volume (71) and a second vaporization volume (72) in fluidic communication with the first vaporization volume (71), the supply member (74) extending inside the first vaporization volume (71), the first and second vaporization volumes (71, 72) being joined by a passage having a cross section smaller than at least one cross section of the first vaporization volume (71), the heat exchange zone preferably overlapping the first and second volumes (71, 72) of the vaporization chamber.

9. Device (1) according to any one of the preceding claims, wherein the heating structure (8) is made up of one or more heating elements designed to heat an upper or lower wall delimiting the vaporization chamber (71).

10. Device (1) according to any one of the preceding claims, wherein the vaporization chamber (71) has no elements for absorbing the liquid to be vaporized.

11. Device (1) according to any one of the preceding claims, wherein the vaporization system (7) includes a steam distribution chamber (76) distinct from the vaporization chamber (71), which is in fluidic communication with the vaporization chamber (71) and which supplies steam to the steam outlet or outlets (77), the steam outlet or outlets (77) opening directly into the distribution chamber (76).

12. Method for treating hair using a device (1) according to any one of the preceding claims, including applying steam to the hair via the steam outlet or outlets (77).

13. Method according to the preceding claim, wherein the total steam flow from the steam outlet or outlets (77) is substantially constant as long as the vaporization chamber (71) is supplied with liquid.

14. Method according to one of Claims 12 and 13, wherein the temperature during application of the steam is higher in the heat exchange zone (Zc) than in the supply zone (Zi), the temperature in the heat exchange zone (Zc) being greater than or equal to the vaporization temperature of the liquid and the temperature in the supply zone (Zi) being lower than the vaporization temperature of the liquid.

15. Method according to any one of Claims 12 to 14, wherein the device includes two jaws (5 ; 6) arranged to face each other and articulated together between a closed treatment configuration and an open configuration in which the hair is engaged between the jaws (5; 6), the method including detecting the configuration of the jaws (5; 6), and the steam is applied depending on the configuration of the jaws (5; 6), steam application notably being activated only when the jaws (5; 6) are in the closed configuration.

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