GB2624881A

GB2624881A - A hair styling appliance

Info

Publication number: GB2624881A
Application number: GB2217912.1A
Authority: GB
Inventors: Timm Joseph; Alexander Carlyle Thomas; Serra Eric; Matthew Lewis Darren
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: WO2024115997A1; GB202217912D0

Abstract

A hair styling appliance comprises a first and second arm (30, 31, fig. 3) arranged to move between a closed position and an open position. One or more electrodes 40, 41 are provided in a least one of the first arm and the second arm to dielectrically heat hair in a heating zone (25, fig.3) between the arms in the closed position. An electromagnetic field is generated by the electrodes when energised. At least one hair gathering member 32 is disposed on the first arm or the second arm and extends along an edge of the heating zone. The hair gathering member is conformable and comprises shielding material to inhibit the electromagnetic field from leaving the heating zone beyond the hair gathering member. The hair gathering member may comprise a flexible structure such as a mesh 34 or it may comprise a flexible structure which has castellated structures (136, fig.8a) or electrically conductive particles (238, fig.9a) distributed evenly throughout. The hair gathering members may be located on both arms forming a contact seal when the arms are in a closed position.

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 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 at least one hair gathering member disposed on the first arm or the second arm and extending along an edge of the heating zone, the at least one hair gathering member being conformable and comprising shielding material to inhibit the electromagnetic field from passing out of the heating zone beyond the hair gathering member.

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 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 hair gathering member comprises shielding material that at least partially or entirely blocks the electromagnetic field generated by the electrodes. The electromagnetic field is therefore inhibited from passing beyond the heating zone in a direction in which the electromagnetic field contacts the hair gathering member. The at least one hair gathering member 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.

The at least one hair gathering member conforms to a shape of the tress of hair as the hair passes across the hair gathering member, which may help to gather strands of hair, which may help style the hair more efficiently. Further, a gripping pressure applied to the hair by the arms is more evenly distributed across the width of the tress of hair being styled. The at least one hair gathering member may be formed of a resiliently deformable material, such as silicone, and deforms to the shape of the tress of hair. The at least one hair gathering member may be formed of a thermally insulating material so as to reduce thermal conduction between the hair and the appliance.

The shielding material may be embedded in the hair gathering member. By embedding the shielding material in the at least one hair gathering member, the hair gathering member may contact the hair without the shielding material contacting the hair, which may help to improve the performance and/or safety of the 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 gathering member to provide electromagnetic field shielding. The shielding material may comprise a copper or aluminium alloy, for example.

The at least one hair gathering member may urge towards and/or contact the opposing arm when the first and second arms are in the closed position. In use, the hair gathering members of the at least one the hair gathering member conform around hair passing between the respective hair gathering member and the opposing arm to form a temporary aperture between that hair gathering member and the opposing arm. The conformability of the hair gathering member ensures that the cross-sectional area of the aperture substantially corresponds to the cross-sectional area of the hair passing through the aperture, so that electromagnetic field emissions are inhibited from passing through the aperture. This may further help to inhibit the electromagnetic field from passing beyond the hair gathering member compared to an appliance in which a gap remains between the hair gathering member and the opposing arm when the arms are in the closed position.

The shielding material may comprise a flexible structure. Accordingly, the shielding material may conform with the at least one hair gathering member in use, which may help to improve the shielding performance of the hair gathering member. The flexible structure may permit the at least one hair gathering member to provide shielding effects without significantly reducing the conformability of the hair gathering member.

The flexible structure may comprise a mesh. The mesh may permit the at least one hair gathering member to conform whilst providing relatively uniform shielding of the electromagnetic field across the mesh. Apertures of the mesh may have a width that is at least 10 times, or at least 50 times, smaller than the wavelength of the electromagnetic field generated by the electrodes. The apertures may have a width in a region from 0.07mm to 2.50mm.

The flexible structure may comprise one or more castellations. Castellations may provide a continuous conformable structure, which may improve the shielding performance of the at least one hair gathering member. The castellations may extend continuously along a length of the at least one hair gathering member which may provide more uniform shielding effects along the flexible structure.

The shielding material may comprise a plurality of electrically conductive particles, for example, embedded into, or coated onto the surface of, the hair gathering member. The particles may have a particle size in the region of 50 microns to 250 microns. Providing the shielding material as electrically conductive particles may permit the shielding material to be distributed throughout the at least one hair gathering member without significantly reducing the conformability of the hair gathering member. Further, manufacture of a hair gathering member comprising particles of shielding material may be relatively simple.

The shielding material may be distributed substantially uniformly along the at least one hair gathering member. This may provide substantially uniform shielding performance along the hair gathering member. This may also provide substantially uniform conformability along the hair gathering member. The shielding material may be distributed substantially uniformly along each hair gathering member of the at least one hair gathering member.

In other examples, the shielding material may be more concentrated in a region along the hair gathering member that, in use of the appliance, is subjected to a stronger electromagnetic field than a different region along the hair gathering member.

The at least one hair gathering member may project from the facing side of the respective arm in a direction normal to the facing side. This may further help to attenuate the electromagnetic field beyond the hair gathering member.

The hair gathering member may project from the facing side by such an extent that the hair gathering member stands proud of the electrodes even when deformed by hair passing over the hair gathering member. The hair gathering member thus may define a hair-contacting surface. In use, the hair gathering member inhibits hair in the heating zone from contacting the electrodes, which may help to improve the performance and/or safety of the appliance. As a result, an air gap is created below the tress of hair. This has the benefit of reducing thermal conduction, and therefore thermal loss, between the hair and the appliance.

Each hair gathering member of the at least one hair gathering member may project from the facing side of the respective arm on which the hair gathering member is disposed.

The at least one hair gathering member may have a length at least as long as the respective edge of the heating zone. Accordingly, a greater percentage of the electromagnetic field generated by the electrodes can be shielded by the hair gathering member.

Each hair gathering member of the at least one hair gathering member may have a length at least as long as the respective edge of the heating zone bounded by the hair gathering member.

The at least one hair gathering member may comprise first and second hair gathering members disposed on the facing side of one of the first arm and the second arm, and bounding respective opposing edges of the heating zone. Providing the first and second hair gathering members 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 first and second hair gathering members inhibit the electromagnetic field from reaching the head of a user regardless of which direction hair passes through the heating zone.

The opposing edges of the heating zone are respective leading and trailing edges of the heating zone, relative to a direction of movement of hair through the heating zone during use of the hair styling appliance. Providing hair gathering members 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 hair gathering member at the leading edge and after the hair passes the hair gathering member at the trailing edge, which may provide more control over heating of the hair by the electrodes.

Further, hair may be held taut along a hair contact line extending between the first and second hair gathering members. This may help to prevent the hair from contacting the electrodes as the hair passes through the heating zone.

The first and second hair gathering members may both be disposed on the facing side of the same arm. This may provide a substantially straight contact line between the first and second hair gathering members.

The at least one hair gathering member may comprise third and fourth hair gathering members, the third hair gathering member disposed on the facing side of the opposite arm to the first hair gathering member and bounding the same edge of the heating zone as the first hair gathering member, and the fourth hair gathering member disposed on the facing side of the opposite arm to the second hair gathering member and bounding the same edge of the heating zone as the second hair gathering member. Providing two hair gathering members bounding an edge of the heating zone may increase attenuation of the electromagnetic field beyond that edge of the heating zone compared to providing one hair gathering member at the edge.

When the first and second arms are in the closed position, a contact seal may be formed between the first and third hair gathering members and a further contact seal may be formed between the second and fourth hair gathering members. In use, opposing hair gathering members conform around hair passing through the respective seal to form a temporary aperture in the seal. The conformability of the hair gathering members ensures that the cross-sectional area of the aperture substantially corresponds to the cross-sectional area of the hair passing through the aperture, so that electromagnetic field emissions are inhibited from passing through the aperture. Accordingly, when the arms are in the closed position and the electrodes are energised to heat hair dielectrically in the heating zone, the shielding material hair gathering members prohibits the electromagnetic field generated by the electrodes from passing through the seal and the further seal. This may increase the shielding performance of the appliance.

Further hair may be tensioned between the seal and the further seal, which may help to prevent hair from contacting the electrodes.

The at least one hair gathering member may extend around a periphery of the heating zone. This may help to inhibit the electromagnetic field from escaping the heating zone via a gap between the arms when in the closed position.

The hair styling appliance may comprise a shield located 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 shield. This may help to at least partially or entirely block the electromagnetic field in directions other than towards the at least one hair gathering member. For example, the one or more electrodes may be embedded in the shield. This may further improve the safety and/or efficiency of the appliance.

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 an end-on sectional view through free ends of arms of the hair styling appliance of Figure 1 in the closed position, according to examples; Figure 5 is a plan view of a free end of an arm of the hair styling appliance of Figure 1, according to examples; Figure 6 is a perspective sectional view of part of the hair styling appliance of Figure 1, according to examples; Figures 7a and 7b are side sectional views of the free ends of the arms of the hair styling appliance of Figure 1 in the closed and open positions, respectively, according to examples; Figures 8a and 8b are side sectional views of the free ends of arms of a further hair styling appliance in the closed and open positions, respectively, according to examples; and Figures 9a and 9b are side sectional views of the free ends of arms of a further hair styling appliance in the closed and open positions, respectively, 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 1-3, and an open position, shown in Figure 2. The arms 30,31 are biased towards the open position. When in the closed position, the arms 30,31 grip 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 portion, or gathering strip, 32 for gripping the hair 70. As is best shown in Figure 4, in this example, there are four gathering strips 32: two on each arm 30,31 on opposing sides of the electrodes 40,41. Each gathering 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 section 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. In the open position, the facing side of the first arm and the facing side of the second arm are spaced apart. 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.

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.

The gathering strips 32 on each arm 30,31 have a height greater than a height of the electrodes 40,41, as best shown in Figure 4. The hair 70 is therefore held taut along a hair contact line 72 extending between opposing gathering strips 32. This hair contact line 72 is spaced from the electrodes 40. As a result, an air gap 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 gathering strips 32 of the arms 30,31 may be formed of a thermally insulating material so as to further reduce thermal conduction between the hair 70 and the appliance 10.

The gathering strips 32 comprise an electromagnetic field shielding material. In this example, each of the gathering strips 32 comprises a flexible mesh 34, but other examples are envisaged, such as those described below with reference to Figures 8a-9b. The mesh 34 in this example is formed from aluminium and is embedded in the resiliently deformable material of the gathering strip 32. In other examples, the mesh may be formed from any other suitable material, such as copper or steel.

Apertures 35 in the mesh have a width of around 1 mm in this example. The gathering strips 32 and the mesh 34 extend along a full length of the heating zone 25, as best shown in Figure 5. The flexible nature of the mesh 34 allows the mesh 34 to deform with the resiliently deformable material of the gathering strip 32 around the tress of hair 70, as best shown in Figures 7a and 7b.

Each of the arms 30,31 houses a respective shielding structure 46,47, as best shown in Figure 6. The shielding structures 46,47 are formed from a copper alloy. 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. In this example, the shielding structures 46,47 are solid bodies. In other examples, the shielding structures 46,47 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.

Together, the shielding structures 46,47 and the gathering strips 32 reduce gaps around the heating zone through which the electromagnetic field could otherwise leak through.

Figures 8a-9b show alternative hair gathering strips according to other examples. Aspects of the haircare appliances of Figures 8a-9b are the same as the haircare appliance 10 described with reference to Figures 1-7b except with regard to the form of the shielding material comprised in the gathering strips. Accordingly, like features have the same reference numbers, but increased by 100 or 200.

In Figures 8a and 8b, the gathering strips 132 in each arm 130, 131 comprise flexible castellated structures 136, which in the example are embedded in the resiliently deformable material of the gathering strip 132 and formed of manganese copper alloy. Castellations in the structures 136 are uniform in height and width along the length of the gathering strips 132. The castellated structure 136 in the first arm 130 opposes the castellated structure 136 in the second arm 131. In use, the castellated structures 136 deform with the gathering strips 132 around the tress of hair 70.

In the example shown in Figures 9a and 9b, the gathering strips 232 in each arm 230, 231 are embedded with particles 238 of silver coated copper. In other examples the particles may be of any other suitable material such as nickel-graphite. The particles 238 have a particle size of around 120 microns and are uniformly distributed throughout the gathering strips 232, allowing the gathering strips 232 to deform around the tress of hair 70 in use.

The above embodiments are to be understood as illustrative examples of the invention. Further embodiments are envisaged. For example, the gathering strips may extend around a full periphery of the heating zone. For example, the shielding material in the gathering strips may take any other suitable form. For example, although the gathering strips and shielding structure are described as comprising a manganese copper alloy, any suitable electromagnetic field absorption material may additionally or alternatively be used. For example, the shielding material in the gathering strips may be disposed on an outer surface of the gathering strips.

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.

Claims

CLAIMS1. A hair styling appliance comprising: a first arm and 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 at least one hair gathering member disposed on the first arm or the second arm and extending along an edge of the heating zone, the at least one hair gathering member being conformable and comprising shielding material to inhibit the electromagnetic field from passing out of the heating zone beyond the hair gathering member.
2. A hair styling appliance as claimed in claim 1, wherein the at least one hair gathering member urges towards and/or contacts the opposing arm when the first and second arms are in the closed position.
3. A hair styling appliance as claimed in claim 1 or claim 2, wherein the shielding material comprises a flexible structure.
4. A hair styling appliance as claimed in claim 3, wherein the flexible structure comprises a mesh.
5. A hair styling appliance as claimed in claim 3 or claim 4, wherein the flexible structure comprises one or more castellations.
6. A hair styling appliance as claimed in any preceding claim, wherein the shielding material comprises a plurality of electrically conductive particles.
7. A hair styling appliance as claimed in any preceding claim, wherein the shielding material is distributed substantially uniformly along the at least one hair gathering member.
8. A hair styling appliance as claimed in any preceding claim, wherein the at least one hair gathering member projects from the facing side of the respective arm in a direction normal to the facing side.
9. A hair styling appliance as claimed in any preceding claim, wherein the at least one hair gathering member has a length at least as long as the respective edge of the heating zone.
10. A hair styling appliance as claimed in any preceding claim, wherein the at least one hair gathering member comprises first and second hair gathering members disposed on the facing side of one of the first arm and the second arm, and bounding respective opposing edges of the heating zone.
11. A hair styling appliance as claimed in claim 10, wherein the at least one hair gathering member comprises third and fourth hair gathering members, the third hair gathering member disposed on the facing side of the opposite arm to the first hair gathering member and bounding the same edge of the heating zone as the first hair gathering member, and the fourth hair gathering member disposed on the facing side of the opposite arm to the second hair gathering member and bounding the same edge of the heating zone as the second hair gathering member.
12. A hair styling appliance as claimed in claim 11, wherein, when the first and second arms are in the closed position, a contact seal is formed between the first and third hair gathering members and a further contact seal is formed between the second and fourth hair gathering members.
13. A hair styling appliance as claimed in any preceding claim, wherein the at least one hair gathering member extends around a periphery of the heating zone.
14. A hair styling appliance as claimed in any preceding claim, comprising a shield located 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 shield.