GB2624882A

GB2624882A - A hair styling appliance

Info

Publication number: GB2624882A
Application number: GB2217913.9A
Authority: GB
Inventors: Timm Joseph; Matthew Lewis Darren; Licming Lambourn Henry; Serra Eric
Original assignee: Dyson Technology Ltd
Current assignee: Dyson Technology Ltd
Priority date: 2022-11-29
Filing date: 2022-11-29
Publication date: 2024-06-05
Also published as: GB202217913D0; WO2024116019A1

Abstract

A hair styling appliance comprises two arms (30, 31, fig.1) coupled together to be moveable between a closed position and an open position. One or more electrodes 40, 41 are arranged to dielectrically heat a tress of hair in a heating zone 25 between the arms in the closed position. An electromagnetic field is generated by the electrodes. A shielding structure, disposed on at least one arm, defines a channel 50 having a length and extending along an edge of the heating zone. The channel faces the other arm and preferably extends parallel to the edge of the heating zone. It may have a constant cross-sectional profile with side walls which are preferably parallel to one another. The depth of the channel may be greater than its width. An upper surface of the channel may be inclined towards the heating zone. There may be a number of concentric channels (250, 251, 252, fig. 6d) separated by a fin (254, fig.6d). The shielding structure at least partially blocks the electromagnetic field by reflecting waves off the side walls of the channel. This reduces interference with other electronic components.

Description

A HAIR STYLING APPLIANCE

TECHNICAL FIELD

The present invention relates to a hair styling appliance.

BACKGROUND

A hair styling appliance may comprise heating plates that are heated to temperatures of around 200 °C. Hair is then clamped between the heating plates, and the high temperatures break hydrogen bonds within the hair, allowing the hair to be reshaped and styled.

SUMMARY OF THE INVENTION

According to the invention, there is disclosed a hair styling appliance comprising a first arm and a second arm opposing one another and coupled together at one end thereof to allow the first arm and the second arm to be moveable between a closed position, in which a facing side of the first arm and a facing side of the second arm are adjacent, and an open position, in which the facing side of the first arm and the facing side of the second arm are spaced apart; one or more electrodes in a least one of the first arm and the second arm to heat dielectrically a tress of hair in a heating zone, the heating zone being a zone between the first arm and the second arm, when in the closed position, in which an electromagnetic field is generated by the electrodes when energised; and a shielding structure disposed on one arm and defining a channel having a length and extending along an edge of the heating zone, the channel facing the other arm.

With the hair styling appliance of the present invention, hair is heated dielectrically. Consequently, in contrast to a conventional styling appliance having heating plates, the hair may be heated without first having to heat a surface of the appliance. The appliance is therefore potentially safer since it is not necessary to heat a surface of the appliance that contacts hair to temperatures of around 200 °C.

The one or more electrodes may be disposed on both the first arm and the second arm. Electrodes on opposing arms may be adjacent to one another when the arms 2.

are in the closed position, which may increase the strength of the electromagnetic field in the hair treatment zone, which may in turn dry the hair more effectively.

The electrodes may emit an electromagnetic field with a radio frequency. Such frequencies may be particularly suitable for use in a hair styling appliance.

The electromagnetic field that is generated by the electrodes when energised can interfere with other equipment comprised in the hair styling appliance. Accordingly, the shielding structure at least partially or entirely blocks the electromagnetic field Generated by the electrodes.

With the arms in the closed position, a gap is present between the arms to permit hair to pass between the arms into and out of the heating zone. The electromagnetic field can escape the heating zone via the gap. Provision of the channel in the shielding structure can help to reduce leakage, via the gap, of the electromagnetic field compared to a planar upper surface. Electromagnetic field waves may enter the channel arid reflect off side walls and/or a base of the channel rather than escape via the gap.

The shielding structure thus may help to control electromagnetic field emissions from the heating zone, for example to help inhibit the electromagnetic field from negatively impacting the performance of other components, such as sensors, in the hair styling appliance.

Suitable shielding material may comprise an electrically conductive material, for example a metal.. Suitable metals may be copper, steel and aluminium. Such materials may be particularly suitable for being embedded in a hair-corralling member to provide electromagnetic field shielding. The shielding material may comprise a copper or aluminium alloy, for example.

The channel may extend parallel to the edge of the heating zone. This may help to ensure uniform attenuation of the electromagnetic field along a length of the heating zone.

The channel and the edge of the heating zone may be substantially straight, which may permit relatively simple manufacture and assembly of the appliance.

The channel may have a constant cross-sectional profile along the length of the channel. That is, the channel may have a constant depth and width along the length of the channel. This may help to ensure uniform attenuation of the electromagnetic field along a length of the heating zone.

Alternatively, the depth and/or width of the channel may vary along the length of the channel. This may allow the electromagnetic field attenuation to be tuned along the length of the channel, for example based on a strength of the electromagnetic field in different regions of the heating zone.

Side walls of the channel may be parallel to one another. This may further help to attenuate the electromagnetic field compared to walls that diverge towards the top of the channel.

The side walls may be substantially normal to the facing side of the arm. This may provide a space efficient in terms of an overall width of the hair styling appliance. Alternatively, the walls may be angled towards the heating zone, which may help to reflect the electromagnetic field back towards the heating zone.

A depth of the channel may be greater than a width of the channel. This may further help to attenuate the electromagnetic field compared to a channel having a greater width than depth.

The length of the channel may be at least as long as the edge of the heating zone along which the channel extends Accordingly, the electromagnetic field may be attenuated along the whole of the edge of the heating zone.

An upper surface of the shielding structure, in which the channel is defined, may be inclined towards the heating zone. This may help to reflect the electromagnetic field back towards the heating zone.

The shielding structure may define a plurality of channels extending along the edge of the heating zone, the plurality of channels extending alongside one another along the edge of the heating zone. This may further help to attenuate the electromagnetic field compared to a shielding structure defining a single channel extending along the edge of the heating zone.

Each of the channels in the plural ty of channels may extend parallel to one another. This may help to ensure uniform attenuation of the electromagnetic field along the length of the edge of the heating zone. This may also provide a space efficient in terms of an overall width of the hair styling appliance.

The channels in the plurality of channels may be substantially identical in cross-sectional profile to one another. This may help to ensure uniform attenuation of the electromagnetic field.

Adjacent channels may be separated by a fin having a width that is less than a width of each of the adjacent channels. This may further help to attenuate the electromagnetic field compared to a shielding structure in which the fin has a greater width than the adjacent channels. This may also provide a space efficient in terms of an overall width of the hair styling appliance.

The edge of the heating zone may be a leading edge of the heating zone, and the shielding structure may further define a channel extending along a trailing edge of the heating zone, the leading and trailing edges being relative to a direction of movement of a tress hair through the heating zone during use of the hair styling appliance. Providing channels at the leading and trailing edges of the heating zone may permit the hair-styling appliance to the used in different orientations, in which hair is passed through the heating zone in opposite directions. The channels help to inhibit the electromagnetic field from reaching the head of a user regardless of which direction hair passes through the heating zone.

Providing channels at the leading and trailing edges of the heating zone may prevent hair from being subjected to the electromagnetic field before the hair passes the leading edge into the heating zone and after the hair passes the trailing edge out of the heating zone, which may provide more control over heating of the hair by the electrodes.

The same number of channels may be disposed along the trailing edge of the channel as are disposed along the leading edge. This may provide substantially equal electromagnetic field attenuation beyond the leading and trailing edges.

The channel may extend around a periphery of the heating zone. The periphery is parallel to a plane of the facing side of the arm on which the shielding structure is disposed. This may help to inhibit the electromagnetic field from escaping the heating zone in all directions via the gap between the arms when in the closed position.

A plurality of concentric channels may extend around the entire periphery of the heating zone, which may further attenuate the electromagnetic field.

The shielding structure may comprise a backing panel that passes behind the one or more electrodes such that, when the arms are in the closed position, the one or more electrodes are disposed between the heating zone and the backing panel. This may help to at least partially or entirely block the electromagnetic field in directions other than through the gap between the arms. For example, the one or more electrodes may be embedded in the backing panel. This may further improve the safety and/or efficiency of the appliance.

The shielding structure may be formed of a single body. This may help further attenuate the electromagnetic field compared to a multi-body shielding structure where gaps may be present between different bodies, through which the electromagnetic field may pass. This may also simplify manufacture and/or assembly of the hair styling appliance.

The appliance may comprise a further shielding structure disposed on the other arm to the arm on which the shielding structure is disposed, the further shielding structure having any of the features of the shielding structure defined above. This may help further attenuate the electromagnetic field compared to a hair styling appliance comprising one shielding structure.

When the arms are in the closed position, at least one channel of the shielding structure aligns with and opposes at least one respective channel of the further shielding structure. This may help further attenuate the electromagnetic field compared to a hair styling appliance in which the first and second channels are misaligned when the arms are in the closed position.

The shielding structure and the further shielding structure may each define a corresponding number of channels, each aligned with a respective channel of the other shielding structure when the arms are in the closed position.

BRIEF DESCRIPTION OF THE DRAWINGS

Examples will now be described with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a hair styling appliance in a closed position, according to examples; Figure 2 is a perspective view of the hair styling appliance of Figure 1 in an open position, according to examples; Figure 3 is a side sectional view through the hair styling appliance of Figure 1 in the closed position, according to examples; Figure 4 is a perspective sectional view of part of the hair styling appliance of Figure 1, according to examples; Figures 5a and 5b are respective end-on cross-sectional views of the free ends of arms of a hair styling appliance that is not according to an example, and the pal of Figure 4, according to examples, respectively; and Figures 6a -6d are end-on cross-sectional views of the free ends of arms of further hair styling appliances, according to examples.

DETAILED DESCRIPTION

The hair styling appliance 10 of Figures 1-3 comprises a body 20, a pair of arms 30,31, a pair of electrodes 40,41, a drive unit 50 and a battery 60. In other examples, the appliance may be mains powered.

The body 20 is generally elongated in shape and houses the drive unit 50 and the battery 60. Each of the arms 30,31 houses one of the electrodes 40,41. The free end of each of the arms 30,31 is chamfered or bevelled. This then helps when inserting a section or tress of hair 70 between the arms 30,31, as shown in Figure 2. In particular, the hair 70 may be more easily gathered at the wider mouth of the arms 30,31 and then guided between the arms 30,31.

Each of the arms 30,31 is pivotally attached to the body 20. The arms 30,31 roughly encapsulate the body 20. The arms 30,31 are moveable between a closed position, shown in Figures 1 and 3, and an open position, shown in Figure 2. The arms 30,31 are biased towards the open position. Wien in the dosed position, the arms 30,31 ()rip the tress of hair 70 within a heating zone 25 defined between the arms 30,31.

Each of the arms 30,31 comprises at least one gripping porfion, or corralling strip, 32 for gripping the hair 70. In this example, there are four corralling strips 32: two on each arm 30,31 on opposing sides of the electrodes 40,41. Each corralling strip 32 is formed of a resiliently deformable material, in this example silicone, and deforms to the shape of the hair 70. As a result, the gripping pressure applied to the hair 70 by the arms 30,31 is more evenly distributed across the width of the tress of hair 70. This then has the benefit that, when the arms 30,31 are in the closed position and the appliance 10 is pulled away from the head of the user, a more even tension is created across the tress of the hair 70.

In this example, each electrode 40,41 comprises a rectangular metal plate encapsulated by electrode insulation 42 located on a facing side of a respective one of the arms 30,31. In the closed position, a facing side of the first arm and a facing side of the second arm are adjacent. Also, when in the closed position, the electrodes 40,41 of the two arms 30,31 oppose one another, and define the heating zone 25 therebetween. In the open position, the facing side of the first arm and the facing side of the second arm are spaced apart.

The drive. unit 50 is coupled between the battery 60 and the electrodes 40,41, and is operable to apply an alternating voltage to the electrodes 40,41. An operating state of the drive unit 50 depends on the position of the arms 30,31. When the arms 30,31 are in the open position, no voltage is applied to the electrodes 40,41. When the arms 30.31 are in the closed position, a voltage is applied to the electrodes 40.41.

In applying a voltage to the electrodes 40,41, an electromagnetic field is created between the electrodes 40,41. Since the voltage applied to the electrodes 40,41 is alternating, the electromagnetic field also alternates. The electromagnetic field spans the heating zone 25 and acts to heat the tress of hair 70 within the heating zone 25. In particular, the alternating field stimulates the oscillation of polar molecules, particularly water, within the hair. The oscillation of the polar molecules in turn generates heat. The electromagnetic field used is tuned for heating water molecules and, in this example, is in the radio frequency range.

Each of the arms 30,31 houses a respective shielding structure 46,47. A perspective cross-sectional view of one of the shielding structures is shown in Figure 4. The other shielding structure 46 is substantially identical, in this example. The shielding structures 46,47 are formed from aluminium in this example. The shielding structures 46,47 are formed as single bodies and bound the respective electrode 40,41 on all sides other than the facing side of the respective arm 30,31. The shielding structures 46,47 reduce leakage of the electromagnetic field beyond the heating zone.

An upper surface 48 of each shielding structure is substantially planar and parallel to the electrodes 40,41 in this example. A channel 50 is disposed in the upper surface 48 and extends around a periphery of the respective electrode 40,41, as best shown in the perspective section view of one of the shielding structures 46, 47 of Figure 4. The channel 50 faces the opposing arm 30,31 when the arms 30,31 are in the closed position. The channel 50 extends parallel to each edge of the electrodes 40,41. Each side of the electrodes 40,41, as viewed in Figure 5b, may be referred to as a leading or trailing edge of the electrodes 40,41, dependent on a direction of movement of hair across the electrode in use of the appliance 10. In this example, the channel 50 extends around an entire periphery of the respective electrode 40, 41. In alternative examples, separate channels 50 may be disposed along each of the leading and trailing edge of the respective electrode 40, 41 (and not extending between the leading and trailing edges).

The channel 50 has a constant depth and width, the depth being greater than the width. Side walls of the channel 50 are substantially normal to the upper surface 48 and parallel to one another. A base of the channel 50 is substantially planar and parallel to the upper surface 48.

Figure 5b shows a cross-sectional end view of the shielding structures 46; 47, electrodes 40;41 and corralling strips 32 of the example hairstyling appliance 10 shown in Figures 1, 2 and 3. As shown in Figures 3 and 5b, in this example, the channels 50 in each shielding structure 46, 47 align with and oppose one another when the arms 30,31 are in the closed position.

The corralling strips 32 on each arm 30,31 have a height greater than a height of the electrodes 40;41, as best shown in Figure 5b. The hair 70 is therefore held taut along a hair contact line 72 extending between opposing corralling strips 32. This hair contact line 72 is spaced from the electrodes 40. As a result; an air cap is created both above and below the tress of hair 70 between the electrodes 40,41. This has the benefit of reducing thermal conduction, and therefore thermal loss, between the hair 70 and the appliance 10. The corralling strips 32. of the arms 30,31 may be formed of a thermally insulating material to further reduce thermal conduction between the hair 70 and the appliance 10.

Figure 5a is not according to an example and is provided for comparison to Figure 5b, which is according to an example. Figure 5a shows a cross-sectional end view of shielding structures 146, 147; electrodes 140; 141 and corralling strips 132 of a hairstyling appliance. The shielding structures 146, 147 are the same as the shielding structures 46, 47 described with reference to Figures 3 and 4; but do not comprise the channel 50 In use, the electromagnetic field F leaks through a gap between the electrodes 140, 141, and has decayed to a predetermined strength at a distance Dl from an edge of the shielding structures 146, 147.

In contrast, as shown in Figures 5b, in use of the appliance 10 described with reference to Figures 1-4 and 5b, the electromagnetic field F leaks through the gap between the electrodes 40,41, and has decayed to the predetermined strength at a distance D2 from an edge of shielding structures 46, 47. The distance D2 is less than the distance Di. Figures 5a and 5b thus show that provision of the channel 50 enhances decay of the electromagnetic field F beyond the heating zone 25 when comparing otherwise alike shielding structures. In this example! the distance D2 is less than half of the distance Dl.

When the electromagnetic field crosses the channel 50, energy passes into the channel 50, where multiple absorptions, reflections and re-absorptions within the channel 50 contribute to electromagnetic field attenuation.

In this example, the shielding structures 46,47 are solid bodies. In other examples, the shielding structures may be hollow or comprise one or more internal cavities, which may reduce weight. In other examples, the shielding structure 46,47 may comprise a non-electromagnetic field absorbing material that is lined with an electromagnetic field absorption material on surfaces of the shielding structure 46,47 that interact with the electromagnetic field produced by the electrodes 40,41 in use.

Figures Sa to 6d show cross-sectional end views of various alternative channel 250 arrangements in the shielding structures 246, 247 of further haircare appliances according to examples. Each arrangement may provide enhanced electromagnetic field decay compared to the arrangement shown in Figure 5a.

In Figure 6a, only one of the shielding structures 247 comprises the channel 250. In Figure 61e, each shielding structure 246, 247 has a channel 250 extending along only one edge of the respective electrode 240, 241. Such arrangements may provide a simpler arrangement than used for the haircare appliance 101 whilst still helping to prevent leakage of the electromagnetic field beyond the heating zone 225.

In Figures 6c and 6d, each shielding structure 246, 247 comprises three channels 250, 251, 252 extending around a periphery of the electrodes 240, 241, Provision of the channels 250, 251, 252 may further enhance decay of the electromagnetic field by increasing the multiple absorptions, reflections and re-absorptions within the channels 250, 251, 252 compared to having only one channel. The channels 250, 251, 252 in these examples are concentrically arranged relative to one another and are substantially identical in depth and width. Although shown with the same number of channels 250, 251; 252 in both of the shielding structures 246, 247, in other examples there may be a different number of channels 250, 251, 252 in one shielding structure 246, 247 compared to the other.

Adjacent channels 250, 251, 252 are separated by a wall, or fin, 254. Each fin 254 has a width that is less than a width of the adjacent channels 250, 251, 252 and is extends perpendicularly to the hair contact line 72. This may maximise the width, or number, of channels that the shielding structure 246; 247 can accommodate for a Given overall width of the appliance, In Figure 6d, the upper surface 248 of each shielding structure 246: 247 is inclined towards the heating zone 225. That is, the top of each fin 254 is inclined towards the heating zone 225; which may help to reflect energy towards the channels 250, 251, 252 in the opposing shielding structure 246 247 and/or back towards the heating zone 225. This may further enhance decay of the electromagnetic field compared to the arrangement shown in Figure 6c.

The above embodiments are to be understood as illustrative examples of the invention. Further embodiments are envisaged. For example, the number of channels or the form of the channels in each shielding structure may differ from the examples described herein. For example, the channels on opposing shielding structures may not align with one another Whilst the hair styling appliance described above and illustrated in the Figures resembles a hair straightener or flat iron, the features described above may be used with other types of hair styling appliance; such as a curling Iron. 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

CLAIMS1. A hair styling appliance comprising: a first arm and a second arm opposing one another and coupled together at one end thereof to allow the first arm and the second arm to be moveable between a closed position, in which a facing side of the first arm and a facing side of the second arm are adjacent, and an open position, in which the facing side of the first arm and the facing side of the second arm are spaced apart; one or more electrodes in a least one of the first arm and the second arm to heat dielectrically a tress of hair in a heating zone, the heating zone being a zone between the first arm and the second arm, when in the closed position, in which an electromagnetic field is generated by the electrodes when energised; and a shielding structure disposed on one arm and defining a channel having a length and extending along an edge of the heating zone, the channel facing the other arm.
2. A hair styling appliance according to claim 1, wherein the channel extends parallel to the edge of the heating zone.
3. A hair styling appliance according to claim 1 or claim 2, wherein the channel has a constant cross-sectional profile along the length of the channel.
4. A hair styling appliance according to any preceding claim, wherein side walls of the channel are parallel to one another.
5. A hair styling appliance according to any preceding claim, wherein a depth of the channel is greater than a width of the channel.
6. A hair styling appliance according to any preceding claim, wherein the length of the channel is at least as long as the edge of the heating zone along which the channel extends.
7. A hair styling appliance according to any preceding claim, wherein an upper surface of the shielding structure, in which the channel is defined, is inclined towards the heating zone.
8. A hair styling appliance according to any preceding claim, wherein the shielding structure defines a plurality of channels extending along the edge of the heating zone, the plurality of channels extending alongside one another along the edge of the heating zone.
9. A hair styling appliance according to claim 8, wherein the channels in the plurality of channels are substantially identical in cross-sectional profile to one another.
10. A hair styling appliance according to claim 8 or claim 9, wherein adjacent channels are separated by a fin having a width that is less than a width of each of the adjacent channels.
11. A hair styling appliance according to any preceding claim, wherein the edge of the heating zone is a leading edge of the heating zone, and the shielding structure further defines a channel extending along a trailing edge of the heating zone, the leading and trailing edges being relative to a direction of movement of a tress hair through the heating zone during use of the hair styling appliance.
12. A hair styling appliance according to any preceding claim, wherein the channel extends around a periphery of the heating zone.
13. A hair styling appliance according to any preceding claim, wherein the shielding structure comprises a backing panel that passes behind the one or more electrodes such that, when the arms are in the closed position, the one or more electrodes are disposed between the heating zone and the backing panel.
14. A hair styling appliance according to any preceding claim, wherein the shielding structure is formed of a single body
15. A hair styling appliance according to any preceding claim, comprising a further shielding structure disposed on the other arm to the arm on which the shielding structure is disposed, the further shielding structure having any of the features of the shielding structure defined in any preceding claim,
16. A hair styling appliance according to claim 15, wherein, when the arms are in the closed position, at least one channel of the shielding structure aligns with and opposes at least one respective channel of the further shielding structure.