CN120187322A

CN120187322A - Hair styling device

Info

Publication number: CN120187322A
Application number: CN202380080029.2A
Authority: CN
Inventors: J·金洛克拉奇; M·法德尔; M·琼斯
Original assignee: Dyson Technology Ltd
Current assignee: Dyson Technology Ltd
Priority date: 2022-11-21
Filing date: 2023-11-08
Publication date: 2025-06-20
Also published as: WO2024110809A1; GB202217356D0; GB2624457A

Abstract

A hair styling device comprises: a core having high thermal conductivity; an outer wall spaced apart from the core, the outer wall comprising an outer surface about which a portion of a user's hair can be wrapped; and a phase change material disposed between the core and the outer wall, the phase change material being adapted to release heat to the portion of the user's hair via the outer surface during use.

Description

Hair styling device

Technical Field

The present invention relates to hair styling devices and kits of parts for styling the hair of a user.

Background

Hair rollers are commonly used to treat or style hair, such as styling or curling hair. Application of heat to the hair of a user alters the hydrogen bonding within the hair keratin. The application of heat is therefore commonly used to curl or wave hair.

Typically, the hot hair roller is preheated prior to being wound into the hair, such as on a base. Once in the hair of the user, as the hot roller cools, the heat stored in the hot mass of the hot roller is transferred to the hair, thereby styling the hair.

Disclosure of Invention

According to a first aspect there is provided a hair styling device comprising a core having a high thermal conductivity, an outer wall spaced from the core, the outer wall comprising an outer surface around which a portion of a user's hair can be wrapped, and a phase change material disposed between the core and the outer wall for releasing heat to the portion of the user's hair via the outer surface in use.

Advantageously, the inclusion of phase change materials in hair styling devices may provide improved styling performance in use as compared to hair styling devices currently known in the art. As used herein, a phase change material may be any material that releases or absorbs energy upon phase change (phase transition). The phase change material may thus store more energy per unit volume than conventional hair styling devices. In some examples, the phase change material may also melt, thereby reaching an operating temperature faster than conventional hair styling devices, resulting in a reduction in the charge time (the time it takes for the hair styling device to be ready to use). This may reduce the power consumption of the hair styling device or kit, which may be environmentally friendly.

The latent heat storage of the phase change material may maintain the temperature on the outer wall surface longer than conventional hair styling devices, which may improve the transfer of energy from the hair styling device to the portion of hair. In other words, most of the energy stored by the phase change material is released while the phase change material maintains its temperature. The phase change material may also allow for weight savings in the hair styling device as compared to conventional hair styling devices.

In use, the wick may surround a heat source, such as a heating element on a base. Of course, embodiments are also contemplated in which the heat source is part of a hair styling device. In these cases, the base may provide an electrical connection to allow the heat source to electrically heat or the heat source may not require a base (i.e., a switch activated in the contained device). In this way, the heat source may transfer heat to the core.

The core has a high thermal conductivity. That is, heat transfer occurs at a higher rate than a core having a low thermal conductivity. Thus, the core is efficient in terms of heat transfer. Cores with high thermal conductivity may thus speed up the time to heat and melt the phase change material and, in some cases, may reduce the power required to heat the phase change material. In some embodiments, the core of the hair styling device may have a thermal conductivity of at least 100W/mK at 20 ℃. To this end, the core may be a metallic material, such as aluminum, or any other suitable electrically conductive material.

The core may be centrally located within the hair styling device. That is, the core may be positioned a uniform distance from the outer wall. In some examples, the core is a tube arranged concentrically with respect to the outer surface. The central placement of the core may allow for more uniform heating of the phase change material. Although in some examples the core may be positioned off-center, for example unevenly distributing the weight of the hair styling device, this may allow for more comfortable use by the user.

In some examples, the diameter of the core of the hair styling device may be less than the uniform distance between the core and the outer wall. The phase change material may thus have a thickness that is greater than the core diameter. This may allow the hair styling device to store a maximum amount of energy while balancing the time it takes for the hair styling device to charge.

In use, the portion of the user's hair is heated by the phase change material releasing thermal energy, thereby heating the outer wall, which has an outer surface around which the portion of hair is wrapped. The outer surface may thus be adapted to receive a portion of the hair of a user. For example, the outer surface may include a flocked layer.

In some examples, the hair styling device further includes means for transferring heat from the core to the phase change material, the means being located between the core and the outer wall. The core heats the phase change material by radiating thermal energy into the phase change material, and because the core is located in the center of the hair styling device, the phase change material closest to the core will melt faster than the phase change material farther away (and closer to the outer wall). The member may be located between the core and the outer wall, in other words, extend through the phase change material. The member may provide a larger surface area to radiate heat through the phase change material. The component may thus provide the advantage of improving the heat distribution in the phase change material. The phase change material may be melted more quickly and/or more uniformly throughout the hair styling device, which in turn may accelerate the melting time of the phase change material (time to fully melt), which may reduce the charging time of the hair styling device (time to prepare for styling). The member may be located entirely within the phase change material and thus not in contact with the core and/or the outer wall. In other examples, the member may be in contact with the core and/or the outer wall. In some cases, the member is integral with one or both of the core and the outer wall.

In some examples, the member extends from the core toward the outer wall. The contact between the member and the core may improve the heat transfer between the core and the member, as the heat transfer is by conduction from the core to the member. This in turn may accelerate the melting time of the phase change material, thereby reducing the charging time of the hair styling device.

In some examples, the member extends from the core more than half the distance from a first point on the core to a second point on the outer wall that is opposite the first point. For example, the core and the outer wall may be concentric tubes. In this case, the member may extend radially from the core towards the outer wall, and the distance from the first point to the second point may be a distance in the radial direction. As described above, having a member with a larger surface area for contacting the phase change material may increase the rate at which the phase change material is melted. Extending at least half way between the core and the outer wall may accelerate the melting time of the phase change material within the hair styling device. In some examples, less than 1mm is between one end of the member and the outer wall. Hair styling devices having at least some space between the ends of the members and the outer wall may avoid the members promoting conductive heating from the core to the outer wall, which may result in uneven heating on the outer surface.

In some examples, the member includes a first portion and a second portion, wherein the first portion and the second portion are separate from each other. A component comprising two (or more) portions may give a substantially branched configuration that may provide more component exposed surface area to the phase change material when compared to a component having a single linear body. Thus, more phase change material may be in contact with a portion of the component, which may increase the melting time.

In some examples, the member includes a plurality of holes. When at least some of the phase change material is in liquid form, it may flow through the member via a plurality of apertures. The flow of the phase change material during melting means that the phase change material may also undergo convective heat transfer, for example in areas of the phase change material remote from contact with the component. Thus, the inclusion of holes through the member may promote more flow of the phase change material than a solid member. Alternatively or additionally, the volume of the phase change material may decrease as it solidifies during cooling. In this way, the phase change material may shrink into the pores, which may result in the advantage that the component is subjected to less stress than a solid component when the phase change material solidifies around the component. The holes may be distributed around the member. The distribution may be uniform across the component or more concentrated in areas subject to higher stresses relative to the remainder of the component (e.g., the points at which the component is divided into the first and second portions). The holes may have different dimensions throughout the component, which may be optimized for example for the corresponding higher areas with larger holes. In some examples, the member may be formed from a mesh. In other examples, the member may form a porous structure around which the phase change material is located.

In some examples, a hair styling device includes a plurality of members distributed around a core for transferring heat from the core to the phase change material. Multiple members distributed around the core may improve the overall heating effect of the hair styling device. For example, by spacing multiple members around the core, it may be advantageously allowed to be able to heat a high surface area of the phase change material. In some examples, multiple components may be easier to manufacture than a single component. That is, a single member that spirals around the core may be more difficult to manufacture on a production line than a plurality of planar disks spaced along the length of the core. The plurality of members may have different characteristics. For example, every other member may have a hole therethrough. In some examples, all of the plurality of components combine the same one or more of the above-described features.

In some examples, the plurality of members each have a length corresponding to a length of the core, the lengths of the plurality of members extending parallel to the longitudinal axis of the core. The length of the plurality of members extending parallel to the longitudinal axis of the core may allow two adjacent members to at least partially segment the phase change material. In examples where the component does not extend all the way to the outer wall, the phase change material segments may of course be connected. For example, the plurality of members may be arranged around the core in a tooth configuration. This may have the advantage of maintaining thermal convection within the liquid phase change material, as each section of phase change material may still have convective heating.

In some examples, each of the plurality of members includes a disk, each disk being spaced apart from an adjacent disk along a length of the core. Two adjacent discs may define a series of phase change material layers along the length of the core. In examples where the member does not extend all the way to the outer wall, the layers may of course be connected. The separation of the phase change material into multiple layers and advantageously into small layers may help reduce separation of the phase change material (e.g., separation of additives contained within the phase change material, etc.) during the life of the hair styling device and thus may extend the life of the hair styling device.

In some examples, the plurality of members are evenly distributed around the core. The uniform distribution of the plurality of members may increase the distribution of heat within the hair styling apparatus relative to the core. In some examples, the plurality of members may be symmetrically arranged about the core.

In some examples, at least one of the plurality of members extends from the core to the outer wall. In addition to the phase change material, the member may conductively heat the outer wall. In some cases, this may be advantageous to reduce the charging time of the hair styling device.

In some examples, each of the plurality of members is identical. Having identical components means that each component has a substantially uniform phase change material heating profile relative to the other components. This may help to maintain uniform heating throughout the phase change material.

In some examples, the phase change material has a melting temperature of at least 50 ℃. Having a melting temperature of at least 50 ℃ can result in an outer surface achievable temperature that is optimal for styling the user's hair. That is, the temperature of the outer surface may be hot enough to change the shape (e.g., curl) of the hair. The melting temperature may be at least 70 ℃.

In some examples, the phase change material has a latent heat of at least 150 kJ/kg. The latent heat of the phase change material in this range may provide the hair styling device with the advantage of an optimized heat storage weight ratio.

In some examples, the phase change material is an organic material. Organic phase change materials may be stronger and cheaper than inorganic materials. Some example organic phase change materials may be CT74, RT111 HC, or erythritol, or a combination thereof. The melting temperature of CT74 is 75 ℃, and the latent heat is 226 kJ/kg. The melting temperature of RT111 HC was 111℃and the latent heat was 210 kJ/kg. Erythritol has a melting temperature of 118℃and a latent heat of 340 kJ/kg.

In other examples, the phase change material is an inorganic material. Some inorganic materials may have a higher latent heat than organic phase change materials. In some examples, the phase change material may be a mixture of organic and inorganic materials. The member may separate the phase change material into layers (or wedges), and each layer (or wedge) may contain a different phase change material. These different phase change materials may be only organic or only inorganic or a combination thereof.

In some examples, the outer wall has a lower thermal conductivity than the core. An outer wall having a lower thermal conductivity than the core may provide a degree of protection to the user, for example by reducing the risk of burns on the outer surface. For example, the outer surface may have a coating with a lower thermal conductivity than the core.

In some examples, the hair styling device further comprises a heat source thermally coupled to the core. For example, the heat source may be at least partially disposed within the core. That is, the heat source may extend through the core such that the core surrounds at least a portion or all of the heat source. The wick may be in contact with a heat source such that heat from the heat source is transferred to the wick by conduction. The heat source may be a heating element, such as a resistive heater.

According to a second aspect of the present invention there is provided a hair styling device comprising a core having a high thermal conductivity, an outer wall spaced from the core, the outer wall comprising an outer surface around which a portion of a user's hair can be wrapped, and a plurality of members disposed around the core, each of the plurality of members extending towards the outer wall, wherein the hair styling device comprises a phase change material disposed between the core and the outer wall for releasing heat to the portion of the user's hair via the outer surface in use, wherein the plurality of members extend through at least some of the phase change material. The heat released to the user's hair may remain constant (defined by the phase transition temperature of the phase change material used) for a period of time.

According to a third aspect of the present invention there is provided a hair styling kit comprising a hair styling device as described above, and a base, the hair styling device being configured to be removably coupled to the base, wherein the base is configured to heat a core of the hair styling device via a heat source when the hair styling device is coupled to the base. The heat source may be part of the hair styling apparatus or part of the base. The heat source may be a heating element, such as a resistive heater.

In some embodiments, the base includes at least one cavity configured to receive at least one hair styling device therein. The base with the cavity may allow for a compact kit when the hair styling device is charged or stored. The cavity may partially enclose the hair styling device, that is, a portion of the hair styling device may be exposed during energization. The hair styling device may have a grip portion or the like exposed from the cavity such that the outer surface is within the cavity. In some embodiments, the base may include a mechanism to lift at least a portion of the hair styling device from the cavity so that the cavity may be completely enclosed by the cavity during charging, while being easily removable.

In some examples, the cavity includes an insulating wall such that when the hair styling device is coupled to the base, the cavity insulates the hair styling device. The walls of the insulated cavity may help to maintain heat within the cavity and thus the temperature of the outer surface of the outer wall. In other words, insulating the cavity may reduce heat loss to the surrounding environment when the hair styling apparatus is energized.

In some embodiments, the base is configured to receive at least one hair styling device in an upright position relative to the base. Heating the core of the hair styling device when the hair styling device is in an upright position (with the longitudinal axis of the core substantially perpendicular to the bottom of the cavity) may reduce the charging time compared to a horizontal configuration. In particular, the time it takes for the phase change material to completely melt may be reduced, for example, the vertical position may allow for improved convective heating within the partially melted phase change material relative to a horizontal configuration. Receiving the hair styling device in the upright position may also reduce the footprint of the base, requiring less material, and thus reducing costs.

In some examples, the base includes a controller configured to maintain the heat source at an optimal temperature for melting the phase change material. The controller may maintain the temperature of the wick, for example, by turning the heat source on and off, and/or maintain the temperature of the heat source at a constant temperature, for example, by controlling the current through the resistive element. To this end, the controller may comprise a temperature sensor and/or a feedback loop. The controller may be, for example, a PID controller.

The optimal temperature may be phase change material specific, as different phase change materials may have different melting temperatures. The optimal temperature may be at least 20 ℃ higher than the melting temperature of the phase change material. In some examples, the controller may maintain the temperature within a range of at least 20 ℃ above the melting temperature of the phase change material and at least 10 ℃ below the flash point of the phase change material.

In some examples, the hair styling kit includes a plurality of hair styling devices. By providing a plurality of hair styling devices, a user may be able to style all of their hair at once, which may improve the convenience of the user in using the kit. For example, the kit may include between 4 and 16 hair styling devices.

In some examples, the base includes a plurality of cavities corresponding to a plurality of hair styling devices. The hair styling devices within the kit may have different diameters and/or shapes so that in use they may style different portions of hair. For example, a hair styling kit may include 3 to 7 devices having diameters smaller than the diameters of the remaining devices in the kit for the front of the user's hair.

Other features and advantages of the invention will become apparent from the following description of preferred embodiments of the invention, given by way of example only, which refers to the accompanying drawings. The above features should be considered combinable with each other, unless otherwise indicated.

Drawings

FIG. 1a illustrates a perspective view of an exemplary hair styling device in accordance with the present invention;

FIG. 1b shows a plan view of FIG. 1 a;

FIG. 2 illustrates a perspective view of an exemplary hair styling device according to the present invention, including one component;

Fig. 3a shows a perspective view of an example of a hair styling device according to the present invention, comprising a plurality of components;

fig. 3b shows a plan view of the hair styling device of fig. 3 a;

Fig. 3c shows a perspective view of another example of a hair styling device according to the present invention, comprising a plurality of members;

Fig. 3d shows a perspective view of yet another example of a hair styling device according to the present invention, comprising a plurality of components;

FIGS. 4a to 4d illustrate the melting of phase change material with the component arrangement of FIG. 3 d;

FIG. 5a shows an exemplary base for a multiple molding apparatus according to the present invention, and

Fig. 5b shows the base of fig. 5a with a plurality of molding machines according to the invention.

Like numbers refer to like elements throughout the specification and drawings.

Detailed Description

Examples of hair styling devices and associated docking stations will now be discussed. In the following description, the hair styling device is a hair roller, but it should be understood that other hair styling devices are also contemplated. The hair styling device has two distinct phases in use, an energy charging phase and a styling phase. As used herein, the charging phase refers to the input of thermal energy into the hair styling device, thereby causing the temperature of the device to rise to and beyond the melting point of the phase change material in order to potentially store energy. The styling phase refers to a phase in which a user uses the hair styling device to style a portion of hair.

Referring now to fig. 1a and 1b, an example hair styling apparatus 100 is shown. Hair styling device 100 includes a core 110 and an outer wall 120. The core 110 and the outer wall 120 have an upper wall 112 and a lower wall 114 extending therebetween. Phase change material 130 is located between core 110 and outer wall 120 and upper wall 112 and lower wall 114.

Core 110 is centrally located within hair styling device 100 and outer wall 120 is concentrically arranged with respect to core 110. The core 110 is tubular. As such, the core 110 may receive a heat source therein (see, e.g., 660a in fig. 5 a). The core 110 is formed of aluminum, which has a high thermal conductivity of 236W/mK at 0 ℃, which means that it is a good thermal conductor.

The outer wall 120 surrounds the core 110 while being spaced apart from the core 110. The outer wall 120 has an outer surface 122 which in use receives a portion of the hair of a user. In this example, the outer surface 122 has a flocked layer (not shown) that may help better grip the hair.

The outer wall 120 has a high thermal conductivity such that heat is efficiently transferred through the outer wall 120 to the outer surface 122. However, the thermal conductivity of the outer wall 120 is less than the thermal conductivity of the core 110. In this way, the outer wall 120 may provide some thermal insulation for the phase change material 130 to reduce rapid heat loss. The upper and lower walls 112, 114 are formed of an insulating material, which may reduce heat loss from any non-molding areas.

Phase change material 130 is positioned between core 110 and outer wall 120 and has a constant thickness throughout hair styling device 100. In this example, the region of phase change material is in contact with either the core 110 or the outer wall 120 such that the entire phase change material (i.e., when viewed as a whole) is in contact with both the core 110 and the outer wall 120. However, an intermediate layer of thermally conductive material is contemplated between the core 110 and the outer wall 120, such as two layers of phase change material arranged concentrically and separated by an intermediate wall.

The phase change material 130 is a material capable of storing and then releasing energy as heat during a solid-to-liquid phase change. In addition, phase change material 130 is a material having a melting point and latent heat that is suitable for the end use of styling a portion of a user's hair. To this end, the phase change material 130 has a high latent heat of at least 150 kJ/kg. The melting temperature of the phase change material 130 is at least 70 ℃. In this example, the phase change material 130 is erythritol, which has a melting temperature of 118 ℃ and a latent heat of 340 kJ/kg.

In use, the wick 110 is heated by a heat source, for example by contact with the heat source. The heat source and its operation are described in more detail below with reference to fig. 4a to 4 d. The core 110 radiates heat to the phase change material 130. The phase change material 130 thus increases in temperature, storing thermal energy as sensible heat. Once the phase change material 130 reaches the melting temperature, the phase change material stops rising in temperature and melting, storing thermal energy as latent heat. The regions of the phase change material 130 closest to the core 110 will heat and melt first because they are closest to the heat source and therefore at a higher temperature. The phase change material 130 thus has a temperature gradient with the hottest regions closest to the core 110 and the colder regions closest to the outer wall 120 such that the phase change material 130 melts in a radiation away from the core 110. The melted phase change material 130 also experiences some convective heating, which may more quickly increase the temperature at the boundary between the melted phase change material 130 and the solid state phase change material 130.

Once the phase change material 130 has melted, it continues to rise in temperature, again storing energy as sensible energy. Phase change material 130 continues to heat until the hair styling device is moved away from (or in equilibrium with) the heat source.

During this charging process, the outer wall 120 is continuously heated by the phase change material 130, which in turn heats the outer surface 122. The temperature of the outer wall 120 will be determined by the temperature of the adjacent regions of the phase change material 130. Thus, in use, when most or all of the phase change material 130 melts, the outer wall temperature 120 will reach its maximum value.

Once the outer wall 120 reaches the desired temperature, the hair styling device is ready to charge and thus can be removed from the heat source. The hair styling device enters a styling phase in which a portion of the user's hair is then wrapped around the outer surface 122.

The phase change material 130 continues to heat the outer surface 122 of the outer wall 120 by energy transfer during the styling phase, thereby styling the portion of hair wrapped therearound. When the outer surface 122 radiates this thermal energy to the hair, the outer surface 122 and subsequent phase change material 130 will cool and the phase change material 130 will begin to solidify. During the curing process, the temperature of the phase change material 130 remains constant and releases its latent heat energy, which continues to heat the outer surface 122. Once the phase change material 130 has solidified, it will begin to cool again, releasing energy in the form of sensible heat. The phase change material 130 will cool until it reaches equilibrium with the ambient temperature surrounding it.

In some examples, hair styling devices 200, 300, 400, 500 include one or more members 240, 340, 440, 540 to aid in transferring heat to the phase change material. Fig. 2 to 3d show various molding arrangements 200, 300, 400, 500 with different component arrangements. It should be understood that any suitable arrangement of components is contemplated in accordance with the present invention, including but not limited to combinations of the described arrangements of components. In other words, any arrangement of components capable of distributing heat from the core to the phase change material is conceivable. Any feature described with respect to one of these example apparatuses should be considered applicable to any other example unless inherently incompatible therewith. For the sake of brevity, the same features of the molding apparatus described herein as described above with reference to FIGS. 1a and 1b will not be repeated.

Referring now to FIG. 2, an example molding apparatus 200 incorporating a structure 240 is shown. Member 240 is positioned between core 210 and outer wall 220 such that it extends into the phase change material (not shown). There is a space (filled with phase change material) between the edge 242 of the member 240 and the outer wall 220. The member 240 is formed of a material having a high thermal conductivity, in this example aluminum, and is welded to the core 210 such that it is in contact with the core.

The member 240 is a continuous sheet of aluminum that spirals around the core 210 such that an edge opposite the edge 242 contacts the core 210, the edge 242 being adjacent to the outer wall 220 but spaced from the outer wall 220. In this way, member 240 extends the length of device 200. The member 240 effectively increases the heating surface area of the core 210 such that the area of the phase change material in contact with the surface having high thermal conductivity increases.

Fig. 3a shows an example hair styling device 300 with an example arrangement of a plurality of members 340, and fig. 3b shows a plan view of fig. 3 a. A plurality of members 340 protrude from the core 310 and radiate outward such that the core 310 and the members 340 have a tooth-shaped cross section (as shown in fig. 3 b). Member 340 extends to outer wall 320. The plurality of members 340 are secured to the core 310 and the outer wall 320, such as by welding. A plurality of members 340 extend along the length of hair styling device 300 parallel to longitudinal axis 302 of core 310 and between upper wall 312 and lower wall 314.

In this example, hair styling device 300 has 12 planar members 340 equally spaced around core 310 (any suitable number is certainly contemplated). The length of the plurality of members 340 is 8.5mm and the length of hair styling device 300 is 9mm (including the thickness of upper wall 312 and lower wall 314). The plurality of members 340 have a thickness of 0.5 mm.

Phase change material 330 is located between core 310 and outer wall 320. Phase change material 330 is positioned between adjacent members 340 and is also divided into portions 330a-l by those members 340. Phase change material 330 is the same material, in this case RT111 HC. In some other cases, one or more of the portions 330a-l may each have a different phase change material.

Fig. 3c shows an example in which hair styling device 400 also has a plurality of members 440. In this example, each of the plurality of members has an extension that curves from the portion of the core 410 toward the outer wall 420. Each member 440 has a first portion 446 that diverges from a second portion 448 at an end 442 of the member 440 adjacent the outer wall 420. Of course, examples are contemplated in which the prongs are closer to core 410, such as examples that include multiple prongs on one member 440.

Fig. 3d shows another example of a hair styling device 500 with eleven members 540. In this example, the plurality of members 540 are disk-shaped members.

The plane of each member 540 is perpendicular to the longitudinal axis 502 of the core 510. A plurality of members 540 protrude around the core 510 toward the outer wall 520. The plurality of members 540 extends approximately 80% of the distance between a point on the core 510 and a facing point on the outer wall 520 and has a length of 28 mm. Each of the plurality of members 540 is equally spaced along the length of the core 510.

Turning now to fig. 4 a-4 d, the charging phase of the molding apparatus 500 of fig. 3d is illustrated. During this charging phase, the core 510 is heated using a heat source (not shown). Thermal energy from core 510 is transferred along member 540 to phase change material 530. That is, both core 510 and member 540 transfer heat to phase change material 530. Thermal energy transfer is primarily by radiation from core 510 and member 540 into phase change material 530. The thermal energy is then stored as sensible heat in the phase change material 530 until the phase change material reaches its melting temperature.

Once the melting temperature is reached, heating via core 510 and member 540 causes phase change material 530 to change phase (melt). The phase change material 530 melts over time, with the regions of the phase change material closest to the core 510 and the member 540 melting earlier than the regions farther from the core 510 and the member 540. Phase change material 530 thus has a melted portion 532 of phase change material 530 (adjacent core 510 and member 540) and another solid portion 534 of phase change material 530 (adjacent outer wall 520). As shown, the melted portion 532 may be continuous around the core 510 and the member 540, or may be a smaller sub-portion. The boundary 536 between the two portions 532, 534 is where the phase change material 530 undergoes a phase change. At boundary 536, phase change material 530 is a mixture of solid and liquid.

As shown by the progression of fig. 4 a-4 d, the area of the melted portion 532 of the phase change material 530 increases over time such that the boundary 536 moves toward the outer wall 520. The melted portion 532 expands radially from the core 510 and the member 540 until most, if not all, of the phase change material 530 melts. After phase change material 530 has changed phase, the temperature of phase change material 530 may again begin to rise, again storing energy as sensible heat. Once the desired temperature of the phase change material 530, and thus the outer surface 522, has been reached, the heat source no longer heats the core 510. This is when at least 95% of phase change material 530 has reached a molten state, hair styling device 500 may thus be used by a user to style hair, entering a styling phase.

Hair styling device 500 is fully charged (i.e., reaches the desired temperature of outer surface 522) in less than 20 minutes, such as 15 minutes.

During the charging phase and the shaping phase, thermal energy from the phase change material 530 is continuously transferred to the outer surface 522 of the outer wall 520. During the charging process, at least some thermal energy from the phase change material 530 is transferred to the outer surface 522 of the outer wall 520. Thus, during the charging phase, the temperature of the outer surface 522 also increases. During the styling phase, the phase change material 530 drops in temperature, releasing thermal energy as sensible energy, which the outer surface 522 releases to the hair. Once phase change material 530 reaches the solidification temperature, phase change material 530 begins to change phase and maintains a substantially constant temperature. This curing releases thermal energy as sensible energy and may maintain the outer surface 522 at a constant temperature. Once phase change material 530 has solidified, it continues to cool, releasing more thermal energy as sensible energy until it reaches room temperature. Throughout the styling process, the phase change material 530 transfers energy to the outer wall 520 so that the outer surface 522 provides the desired thermal effect for styling hair.

As shown in fig. 5a and 5b, a base 650 is used for powering the hair styling device. The base 650 has a plurality of cavities 652a-c from which heat sources 660a-c protrude. Heat sources 660a-c are coupled to electrical connection 654.

Each cavity 652a-c is each shaped to receive a corresponding hair styling device 600a-c, respectively (as shown in FIG. 5 b). The shape of each cavity 652a-c corresponds to the shape of a corresponding hair styling device 600 a-c. The chambers have a tolerance of 0.5mm to 2mm such that the respective hair styling devices 600a-c fit relatively tightly therein such that there is little air gap between the outer surfaces 622 of the respective hair styling devices 600a-c and the walls of the chambers 652 a-c. In some cases, the cavity has an insulating wall (not shown).

The cavities 652a-c within the base 650 may be oriented such that each respective hair styling device 600a-c is energized in an upright position relative to the base 650. That is, the upper and lower walls 612, 614 extending between the core (not shown) and the outer surface 622 of the outer wall (not shown) are parallel to the base 656 of the chassis 650. In use, the base of the mount 650 will typically rest on a surface. In this way, gravity may act parallel to the longitudinal axis of hair styling devices 600 a-c.

Heat sources 600a-c protrude from the base of respective cavities 652a-c such that heat sources 600a-c fit within the cores of respective hair styling devices 600a-c placed within cavities 652 a-c. During energization, heat sources 600a-c are in contact with the cores of hair styling devices 600 a-c. Heat sources 600a-c are electrically driven resistive heaters.

The base 650 also includes an electrical connection 654, such as a plug or a battery. The electrical connection 654 is electrically coupled to each heat source 660a-c to provide an electrical connection to heat the heat sources 660a-c.

The base 650 includes a controller 658a-c associated with each heat source 660a-c. The controllers 658a-c are PID controllers that can activate and deactivate the heat sources 660a-c, for example, by controlling electrical connections. Once a desired temperature of the phase change material or outer surface 622 of one of hair styling devices 600a is achieved, the corresponding heat source 660a is turned off. The base 650 includes a temperature sensing device (not shown) in the cavity 652a therein, which is coupled to the controller 658a.

In some examples, the controller may be a single controller that turns on and off some or all of the heat sources 660a-c in one action. In other examples, the base 650 may have a switch and timer arrangement for controlling the heating heat sources 660a-c.

As shown in FIG. 5b, a portion 604a-c of hair styling device 600a-c protrudes from its respective cavity 652 a-c. Portions 604a-c may allow a user to grasp hair styling device 600a-c to remove it from base 650. Thus, the portions 604a-c may be additional portions of the top of the device as described with reference to the previous figures. The portion is a heat insulating cap or the like.

The base and one or more hair styling devices together provide a hair styling kit. The kit includes hair styling devices of various sizes for styling different portions of the user's hair. Although illustrated as three hair styling devices, the kit may include any suitable number. The kit may also include optional features, such as heat protective gloves and/or clips, to help secure each molding device in place on the user's head.

The above examples should be understood as illustrative examples of the present invention. Further embodiments of the invention are envisaged. For example, while the above description refers to hair styling devices (at least core and outer surface) as tubular, any suitable shape may be used, such as frustoconical. Those skilled in the art will appreciate that the change in shape of the outer surface and/or the device will generally have a direct effect on the style of waves or curves in the hair of the user. In these examples, the core may be of a shape corresponding to the entire device, i.e. so that the ratio of phase change material to core remains substantially constant. In addition, the cavities on the charging base may be complementarily shaped to closely fit each molding machine.

The heat source is described above as forming part of the base, however in some examples the heat source may be part of a hair styling apparatus, such as a resistive heater disposed on the inside and thermally coupled to the wick. In these cases, the base may provide an electrical connection to allow the heat source to provide heat by resistive heating.

It is to be understood that any feature described in relation to any one embodiment may be used alone, or in combination with other features described, and may also be used in combination with one or more features of any other of the embodiments, or any combination of any other of the embodiments. Furthermore, equivalents and modifications not described above may also be employed without departing from the scope of the invention, which is defined in the accompanying claims.

Claims

1. A hair styling device comprising:

a core having a high thermal conductivity;

An outer wall spaced from the core, the outer wall comprising an outer surface about which a portion of a user's hair may be wrapped, and

A phase change material disposed between the core and the outer wall, the phase change material for releasing heat to the portion of the user's hair via the outer surface in use.

2. The hair styling device of claim 1 further comprising means for transferring heat from the core to the phase change material, the means being located between the core and the outer wall.

3. The hair styling device of claim 2 wherein the member extends from the core toward the outer wall.

4. A hair styling device according to claim 3 wherein the member extends from the core more than half the distance from a first point on the core to a second point on the outer wall opposite the first point.

5. The hair styling device of any one of claims 2 to 4 wherein the member comprises a first portion and a second portion, wherein the first portion and the second portion are separate from one another.

6. The hair styling device of any one of claims 2 to 5 wherein the member comprises a plurality of apertures.

7. A hair styling device according to any preceding claim wherein the hair styling device comprises a plurality of members distributed around the core for transferring heat from the core to the phase change material.

8. The hair styling device of claim 7 wherein the plurality of members each have a length corresponding to the length of the core, the lengths of the plurality of members extending parallel to the longitudinal axis of the core.

9. The hair styling device of claim 7 wherein each of the plurality of members comprises a disc, each disc being spaced apart from an adjacent disc along the length of the core.

10. A hair styling device according to any of claims 7 to 9 wherein the plurality of members are evenly distributed around the core.

11. The hair styling device of any one of claims 7 to 10 wherein at least one of the plurality of members extends from the core to the outer wall.

12. The hair styling device of any one of claims 7 to 11 wherein each of the plurality of members is identical.

13. A hair styling device according to any of the preceding claims wherein the phase change material has a melting temperature of at least 50 ℃.

14. A hair styling device according to any of the preceding claims wherein the phase change material has a latent heat of at least 150 kJ/kg.

15. A hair styling device according to any of the preceding claims wherein the phase change material is an organic material.

16. A hair styling device according to any of the preceding claims wherein the outer wall has a lower thermal conductivity than the core.

17. The hair styling device of any of the preceding claims wherein the hair styling device further comprises a heat source thermally coupled to the core.

18. A hair styling kit comprising:

The hair styling device according to any of claims 1 to 18, and

A base, the hair styling device configured to be removably coupled to the base,

Wherein the base is configured to heat a core of the hair styling device via the heat source when the hair styling device is coupled to the base.

19. The hair styling kit of claim 18 wherein the base comprises at least one cavity configured to receive at least one hair styling device therein.

20. The hair styling kit of claim 19 wherein the cavity comprises an insulating wall such that when the hair styling device is coupled to the base, the cavity insulates the hair styling device.

21. A hair styling kit according to any one of claims 20 to 20 wherein the base is configured to receive at least one hair styling device in an upright position relative to the base.

22. A hair styling kit according to any one of claims 18 to 21 wherein the base comprises a controller configured to maintain the heat source at an optimum temperature for melting the phase change material.

23. A hair styling kit according to any one of claims 18 to 22 wherein the hair styling kit comprises a plurality of hair styling devices.

24. A hair styling kit according to claim 23 when dependent on claim 19 wherein the base comprises a plurality of cavities corresponding to the plurality of hair styling devices.