Hair Styling Device

The invention relates to a hair styling device, and in particular to a device which can be used to dry and/or style hair. The device is expected to be effective in partially straightening curly hair, often called “hair taming”, and also for drying and/or smoothing straight hair.

Notwithstanding that the device could be used to dry hair without any intention to style the hair, the term “styling” is used throughout this specification because the device will normally act to straighten and/or smooth the hair as it is being dried and some styling will therefore occur.

For convenience, the following specification will refer to the styling of hair by women, but it is recognised that this applies also to men, and in particular the present invention can also be used by men.

It is desired to dry hair which has been washed or otherwise made wet. Whilst hair will dry naturally it is not possible to control the styling of the hair when it dries naturally. Accordingly, most women prefer to control the drying procedure, for example by using a hair dryer to blow hot air onto the hair. Typically, the hair will be partially dried by a towel before using the hair dryer, so that the hair drier is used to dry hair which is damp rather than wet. The styling of the hair can be at least partially controlled by brushing the hair as it is being dried by the hair dryer.

Many hair dryers can be fitted with nozzles to provide a more concentrated air flow, and diffusers to provide a less concentrated air flow, when desired for a particular drying/styling operation.

It is also desired to style hair by adding waves or curls to naturally straight hair or by straightening naturally wavy or curly hair. To style hair in this way it is necessary to modify some of the chemical bonds which give the hair its natural form. The chemical bonds can be modified chemically with a perming solution, or through the application of heat and/or pressure.

Many women will combine the drying and styling procedures. For example, the heat generated by the hair dryer can be used also for styling, such as curling the hair around a circular brush as it is being dried. It is known to provide modified brushes which can be connected directly to a hair dryer so that heated air is blown outwards from the core of the brush and onto the hair. In US/for example a motor, impeller and heating element (i.e. the hair dryer components) are located in the handle of a styling brush. In a further modification the curling brush can be rotated automatically.

Many women will use a hair straightener to style the hair, either after the hair has been dried as above, or as the final stage of the drying procedure. Hair straighteners are a particular form of hair styling device which use a combination of heat, pressure and tension upon the hair. Hair straighteners were originally referred to as “straightening irons” to reflect the fact that they replicated the action of ironing the hair, i.e. pressing the hair between a heated “iron” and a flat surface.

Most hair straighteners comprise a pair of arms which are hinged relative to one another, each arm carrying an electrically-heated hair-straightening panel. Each arm has a handle part which can together be gripped by the user. With the arms in their open condition the user inserts the proximal or scalp end of a chosen section of hair between the arms and then presses the arms together so that the section of hair is pressed between the hair-straightening panels. The hair straightener is then moved away from the scalp and the section of hair is heated and pressed as it passes between the panels. The hair is styled by the heat and pressure applied to the hair by the panels. The section of hair remains hot as it leaves the panels, and the section of hair between the user's scalp and the panels is put under tension and held under tension as it cools. The combined effect of heat and tension act to straighten the hair.

Typically, to straighten the hair the arms are oriented so that the hair-straightening panels are substantially perpendicular to the scalp and the section of hair is pulled in a substantially linear direction between the panels. It is also possible, however, to orient the arms relative to the scalp so that the hair is forced to bend as it leaves the panels. Notwithstanding that the hair between the user's scalp and the panels is put under tension, forcing the hair to bend around a relatively sharp edge as it first leaves the panels can add a wave or curl to the section of hair.

DE 10 2006 037 647 discloses a modified hair straightener with an additional pair of outer shells which can be rotated around the arms to define the bend which the hair must pass as it leaves the panels.

It is understood that the heat and pressure which are applied by a hair straightener acts to distort (flatten) the cross-sectional shape of the hair. Human hair has an outer cuticle comprising layers of flat thin overlapping cells or scales. Flattening the hair, and in particular flattening the cuticle, increases the alignment of the overlapping scales, which can increase the reflection from the hair and enhance the sheen upon the hair. Many users believe that styling their hair in this way makes their hair look more healthy because of the increased sheen achieved by the use of hair straighteners.

Hair crimpers are another type of hair styling device. Hair crimpers differ from hair straighteners in utilising corrugated panels. Also, unlike hair straighteners in which the hair is moved between the hair-straightening panels when the panels are pressed together, in hair crimpers the hair is clamped statically between the crimping panels until the style is set. Accordingly, the user styles discrete parts of a section of hair sequentially by clamping a part of the section of hair, then separating the panels and re-positioning them along the section of hair before clamping another part of the section of hair, and so on until all of the section of hair has been styled.

Hair wavers, including jumbo wavers, share the same operating principle as hair crimpers, but have larger amplitude corrugations so as to form waves of larger amplitude in the user's hair.

Accordingly, whilst hair straighteners and hair crimpers/wavers share the feature of opposing heated panels, and share the principle of operation that the user applies pressure to the hair between the heated panels to style the hair, they differ in that the hair is moved between the panels with hair straighteners, but is not moved between the panels with hair crimpers/wavers.

Other hair styling devices are provided to curl hair, for example WO 2009/077747, WO 2012/080751 and WO 2013/186547. WO 2015/132594 provides a device which can be used to curl or straighten hair.

It is understood that the regular and repeated use of hair styling devices, and in particular the over-styling of hair, can damage the hair. The regular and repeated distortion of the hair caused by hair straighteners can for example cause long-lasting damage to the hair. It is recognised that heating the hair to a high temperature and applying a large pressure can each cause long-lasting damage when applied separately, and the likelihood of damage increases when heat and pressure are applied together as in hair straighteners and hair crimpers/wavers.

WO 2019/238961 provides a hair straightener which seeks to reduce the likelihood of damage by somewhat separating the heating and pressing operations, allowing the user's hair to withstand the combined effects of heat and pressure for a reduced period of time.

A multifunctional hair styling device utilising hot air is disclosed in Chinese patent application 105 942 698. The device has two movable arms along which heated air is blown. The air flow can be controlled to cause hot air to leave the arms by way of a relatively large end aperture at the end of each arm; if the arms are moved to lie against one another the device can be used similarly to a conventional hair dryer. Alternatively, the air flow can be directed to a large number of side apertures, the side apertures in one arm facing the side apertures in the other arm. In this configuration the device can be used as a hair straightener with a section of hair being heated and pressed as it is passed between the arms (so-called “pinch styling”). In a third configuration the arms can be separated with the air flow directed to the side apertures to create a relatively diffuse hot air flow.

WO 2020/169849 discloses another multifunctional hair styling device in which a hair straightener provides a removable handle of a hair dryer.

WO 2021/019239 discloses a hair drying and styling device comprising a pair of hinged arms. Each arm has two heating panels, and in use each heating panel of one arm is pressed against a heating panel of the other arm similarly to a conventional hair straightener. Each arm has a space between its heating panels and an air flow channel which opens into the space through respective apertures. A motor, impeller and heater are located in the air flow channel and air can thereby be heated and blown into the space to dry and heat a section of hair as it passes between the arms. In one embodiment the air flow enters the space through apertures in both arms, and in another embodiment the air flow enters the space through apertures in one arm and leaves the space through exhaust apertures in the other arm.

DE 201 19 863 U1 also discloses a hair drying and styling device comprising a pair of hinged arms, each arm carrying a heated panel whereby the heated panels can be pressed together in use. The device has an air flow channel along each of the arms. The air is heated and acts primarily to heat the panels but there are apertures in the panels through which at least some of the hot air can flow to engage the hair directly. The heated panels are corrugated, the depth of the corrugations varying across the panels.

FR 2 937 839 discloses a hair styling device having a pair of hinged arms. One of the arms can be connected to a hair dryer whereby air can flow along the arm and pass through apertures in a styling panel mounted to the arm.

It is an object of the present invention to provide a device which can be used to style hair whilst reducing the damage caused (or likely to be caused) to a user's hair, especially following repeated use of the device.

It is another object of the invention to provide a device for styling hair which can be operated similarly to a hair straightener in applying heat and some tension to the hair but whilst applying significantly less (or perhaps minimal) pressure to the hair.

It is another object of the invention to provide a device for styling hair between two heated panels whilst maintaining a gap between the panels in order to avoid or at least reduce the distortion of the hair.

It is another object of the invention to provide a device for drying and styling hair, ideally damp hair which has previously been partially dried.

According to a first aspect of the invention there is provided a hair styling device comprising: a first panel;

The first and second panels are hair-styling panels and in use a section of hair is styled (and perhaps also dried) between the panels.

During use of the device heated air is blown along the air flow channel, through the first apertures, through a section of hair located between the first and second panels, through the second apertures and along or through the exhaust channel. Accordingly, air passes into the space or gap between the first and second panels by way of the first apertures and not by way of the second apertures. The air flow is substantially controlled and, as it passes from the first panel to the second panel, the air moves between and approximately perpendicular to the individual hairs in a section of hair between the panels.

The inventors have found that allowing the air to exhaust through the second panel avoids much or all of the air passing along (substantially parallel with) the section of hair as the air seeks to escape from between the facing panels. At least some of that air would flow along the hair towards the root end and that air flow could lift some of the scales of the cuticle. Lifting the scales of the cuticle is contrary to the desired action of flattening the cuticle and the resulting sheen created in the section of hair would be reduced (perhaps encouraging the user to repeat the procedure in an attempt to obtain the desired sheen). By minimising the air flow along the section of hair the invention according to this aspect reduces the unwanted lifting of the scales and thereby reduces the likelihood of the user repeating the procedure, in turn reducing the likelihood of damage to the hair.

The inventors have also appreciated that the sheen on the user's hair can be enhanced significantly without distorting or flattening the hair. Providing a non-zero spacing between the panels in their closed condition limits the pressure which can be applied to the hair and thereby limits (and preferably substantially avoids) distorting the hair. Nevertheless, the cuticle can be flattened and the sheen on the user's hair can be enhanced.

Preferably, the panels in their closed condition are spaced apart by a distance greater than approximately 0.2 mm. It is understood that the thickness of human hair varies from around 0.02 mm to around 0.18 mm; arranging that the spacing between the panels will exceed the top end of that range ensures that the panels cannot be pressed together sufficiently to distort an individual hair. Whilst some distortion of some of the hairs might occur in a section of hair in which many individual hairs are stacked on top of each other, the likelihood of damaging (and in particular repeated) distortion is significantly reduced. In particular, it is not likely that all of the individual hairs will be distorted, and any hairs which are distorted will likely be distorted significantly less than with conventional hair straighteners.

Desirably the panels in their closed condition are spaced apart by a distance greater than approximately 0.5 mm, and ideally approximately 1 mm. It will be appreciated that such spacings will further reduce (and potentially eliminate) the likelihood of distorting or flattening individual hairs (or at least will reduce the proportion of the hairs which are distorted).

Preferably, the spacing between the first and second panels in the closed condition is adjustable by the user. For example, a user might be able to set the spacing in one or more discrete steps between a predetermined minimum spacing (for example 0.8 mm) and a predetermined maximum spacing (for example 1.5 mm), the chosen spacing being suited to effectively style the hair of a particular user. A particular user might also wish to vary the styling operation by using a different spacing at different times.

Accordingly therefore, in the present invention the panels are spaced apart in the closed condition. The closed condition is that in which the device is used to dry and style hair, so that the closed condition represents the minimum spacing between the panels.

Providing corrugated panels increases the path along which the section of hair must travel as it passes between the panels, without increasing the overall width of the panels. It will be understood that, for a given rate of movement, the section of hair will take longer to pass between corrugated panels than flat panels of the same overall width. The longer travel time can increase the volume of heated air which engages the section of hair as the hair passes between the panels. It is desirable to minimise the overall width of the hair styling device (and therefore the panels) to increase its aesthetic appeal.

Providing corrugated panels also increases the surface area of the panels for a given width. Increasing the surface area of the panels allows for a greater number of apertures (or alternatively larger apertures, or both) for each panel and thereby enables an increase in the air flow rate through the panel.

In addition, corrugated panels will create some drag or friction in the section of hair as the hair engages the peaks of the corrugations and is caused to bend around those peaks. This provides two benefits. Firstly, because the panels are spaced apart by a distance greater than the thickness of an individual hair, it has been found to be necessary to provide some frictional resistance to the hair in order to reduce the likelihood that individual hairs will migrate (or be blown) along the panels and out of the gap between the panels. The corrugations have been found to create sufficient friction to retain the hair in the gap between the panels. Secondly, even a small amount of drag will cause tension in the section of hair between the scalp and the panels which can help to straighten the hair as it remains hot after leaving the panels. Notwithstanding that the panels are spaced apart therefore, the use of corrugated panels better enables the device to straighten hair, which is achieved without compressing or distorting the hair.

The term “corrugated” is used to describe the wave-like shaping of the panels, but it should not be inferred that there must be a plurality of complete waves in each panel. Whilst more than one wave for each panel can be provided, the invention can also be utilised with only a single wave (i.e. one complete peak plus one complete trough) for each panel. The invention can also be utilised with less than one complete wave, for example a half wave (or less than a half wave) for each panel. In these latter embodiments one of the panels is convex and the other is concave.

The number and depth of the peaks and troughs in the corrugations can be chosen to suit the application. It will be understood that the corrugations are primarily to increase the surface area of the panels and also to increase the path length for the hair between the panels. The same increased surface area and path length can be provided by one large corrugation or several smaller corrugations and both are within the scope of the present invention. It will also be understood that the surface area and path length will be increased more by corrugations having a larger amplitude. Increasing the amplitude will also increase the drag upon the hair as it passes between the panels, and thereby increase the tension in the hair between the scalp and panels. Increasing the tension can better straighten the hair as above described, but the amplitude should not be so great that the hair is distorted as it passes between the panels, or is damaged by excessive tension.

Whilst reference is made to an impeller it will be understood that other components could be used to move the air, such as a fan or a turbine for example. In the present application the term “impeller” is used as a general term to encompass any component which can be driven by the motor to move air.

In a conventional hair straightener the heat is supplied by electrical heating elements mounted in the hair-straightening panels; in the present invention some or all of the heat is provided by air which is heated by the heating element in the air flow channel and subsequently blown through the apertures in the first panel onto the hair passing thereacross. In some embodiments the heat may be provided solely by way of this heated air. Preferably, however, the device includes a secondary heat source for heating and/or drying the hair, for example the first and/or second panel may be directly heated, desirably by way of dedicated secondary electrical heating elements, most suitably ceramic heating elements. In these preferable embodiments the hair is heated by a combination of heated air and the directly heated panel(s).

Preferably, if the first and/or second panels are directly heated, those panels are thermally conductive, for example metallic. The direct heating elements can therefore be located in a position which does not obstruct any of the first and/or second apertures, the heat which is generated by the secondary heating element spreading across the respective panel by conduction. Ideally, the secondary heating elements are located at one or more edges of the first and/or second panels.

It can be arranged that the (first and/or second) panel is heated by its secondary heating element to a temperature which is higher than the temperature of the heated air passing through the first apertures. It can alternatively be arranged that the (first and/or second) panel is heated by its secondary heating element to a temperature which is lower than the temperature of the heated air passing through the first apertures, or the temperatures can be substantially the same. The operating temperature for the heated air and/or for the panel(s) may be adjustable by the user so that a particular heating regime can be provided which is suited to a particular hair type and to a particular styling operation. For example, for some operations it may be desired to dry and/or style a section of hair with a combination of heated air and secondary heating, whereas for other operations only heated air is used and the secondary heating elements are switched off.

An alternative secondary heating arrangement is to use non-contact heating such as infra-red radiation. It can for example be arranged that one or more sources of infra-red radiation is located behind the first panel and/or the second panel with the radiation passing through the first and/or second apertures to heat the section of hair between the panels. The different possible heating regimes described above can be utilised with this secondary heating arrangement also.

Desirably, the air is heated to between around 100° C. to around 130° C. in the air flow channel. This is substantially the same temperature to which air is heated by a conventional hair dryer for example. The air is cooled by its engagement with the (damp) hair and will typically be exhausted from the device at a significantly lower temperature (for example around 70° C., which is expected to be cool enough to avoid burning the user if the exhaust air should engage the scalp for example).

The electrical heating element in the air flow channel is preferably an array (mesh) of metallic filaments which are heated by the passage of an electric current through the filaments. Such heating elements are typically used in hair dryers and are an effective means to heat air passing between the filaments. If secondary heating elements are used for the first and/or second panels they are preferably ceramic heaters.

Preferably, the exhaust channel comprises one or more openings through which the air can pass (passively) out of the device after passing through the second apertures. Alternatively, the air can be moved (actively) to or along the exhaust channel, for example by a second or exhaust impeller in the exhaust channel. The air can thereby be drawn through the second apertures, past the second impeller and out of the device. Alternatively again, the exhaust channel can be connected to the air flow channel to recirculate some or all of the air within the device. This latter option has the potential benefit of saving energy because the air passing the heating element in the air flow channel will be above ambient temperature; it has the potential disadvantage that the recirculating air contains more moisture than ambient air which might limit the temperature increase as the air passes the heating element.

The combined cross-sectional area of the second apertures is preferably at least as large as (and desirably greater than) the combined cross-sectional area of the first apertures. In one embodiment the combined cross-sectional areas of the first and second apertures are the same. In such arrangements the second apertures do not restrict or throttle the air flow and the likelihood of air flowing along the hair to escape other than through the second apertures is reduced.