Hair drying and styling device and method

Abstract

A device for drying and styling hair, comprising: first and second arms opposed to each other, the arms adapted to move between an open configuration for receiving a length of wet hair between the two arms and a closed configuration adjacent to the hair such that, in use, the first and second arms are movable relative to each other; an arm compartment for hair to pass through is formed when the arms are in the closed configuration, and wherein the airflow duct is disposed within and along at least one of the first and second arms; and means for delivering an air flow along the conduit within at least one of the first and second arms and subsequently into the arm compartment. A method of drying (and optionally simultaneously styling) hair using such a device is also provided.

Description

[0001] This application is a divisional application of a patent application with application number 2020800553747, application date July 29, 2020, and invention name “Device and method for drying and styling hair”. Technical Field

[0002] The present disclosure relates to a device for drying and styling human (or conceivably animal) hair, e.g., after washing the hair or as part of a styling (setting) process. That is, the hair is wet (or "towel dried") prior to use of the present disclosure, and can then be dried and styled using the present disclosure. Such drying and styling of hair can be performed, e.g., by a user on their own hair, or by a hair stylist. It should also be noted that the term "wet" as used herein should be interpreted broadly to include not only hair that is wetted with water, but also hair that is wetted with a liquid other than water. For example, the hair can be wetted with a solvent-based colorant that can be dried using the present disclosure. Background Art

[0003] As is known, conventional hand-held hair dryers contain an electric fan for blowing out a stream of cool or hot air to dry a person's hair. The fan draws ambient air into the body of the hair dryer and blows the air stream toward the hair to be dried. When blowing hot air, an electric heating element, usually incorporated into the body of the hair dryer, is used to heat the air stream before it leaves the hair dryer. Optionally, the hair dryer may be equipped with a concentrator nozzle attachment for enhancing and directing the air stream, or a diffuser attachment for more gentle delivery of air.

[0004] However, conventional hair dryers may be noisy, heavy and bulky in general. In addition, conventional hair dryers may be difficult to use and may be difficult to achieve desired results for users (particularly home users who handle their own hair), particularly in styling hair while drying hair. For example, a hair dryer is often used simultaneously with a hairbrush or comb or other styling equipment to style hair during the drying process. The styling process may be, for example, straightening hair or providing hair with "body and volume" (if necessary, applying styling products such as mousse, gel, wax, hair spray, etc. before or after styling). Manipulating a hair dryer and a brush (or comb, etc.) around the head simultaneously may be inconvenient for the user and generally requires a certain degree of skill to achieve the desired result.

[0005] Therefore, while using a conventional hair dryer is the quickest way to dry hair, it can be very difficult and / or time consuming to achieve the desired end result in terms of styling. To do this, the user must use a brush and / or additional hair styling tools.

[0006] As an alternative to traditional hair dryers, some people use products such as hot air brushes or hot air paddle brushes when styling their hair. However, such products, while easy to use, dry the hair slowly.

[0007] Another category of quick and easy-to-use products are so-called "wet to straight" hair straighteners. Such products dry and straighten the hair by drawing wet hair between a pair of heated plates mounted on opposing arms of the device. These devices tend to use conductive heat on wet hair at high temperatures (typically 185° C. to 230° C.), but can damage the hair and / or be perceived as damaging the hair due to cavitation sounds (hissing) or the use of elevated temperatures near the denaturation temperature of wet hair. Summary of the invention

[0008] The present disclosure is directed to providing an alternative apparatus and method to conventional handheld hair dryers for drying hair by combining the functionality and benefits of conventional hair dryers with the functionality and benefits of hair straighteners in one device of a hand-held size. Thus, advantageously, the disclosed embodiments provide an apparatus for drying and styling hair as a single handheld device that is simple to use and provides more flexibility than maneuvering a conventional hair dryer and a brush, comb, or other styling device around the head at the same time.

[0009] According to a first aspect of the present disclosure, there is provided a device for drying and styling hair, comprising:

[0010] a first arm and a second arm opposed to each other, the first arm and the second arm being adapted to move between an open configuration for receiving a section of wet hair therebetween and a closed configuration adjacent the hair so that, in use, an inter-arm chamber is formed for the hair to pass through when the first arm and the second arm are in the closed configuration, and wherein an airflow duct is disposed within and along at least one of the first arm and the second arm; and

[0011] Means for conveying a gas flow, which conveys the gas flow along a duct in at least one of the first arm and the second arm, and then conveys the gas flow into the inter-arm chamber.

[0012] The term "chamber" used herein should be broadly interpreted to include a chamber at least one side of which is partially open as well as a closed chamber.

[0013] By the construction of the device, including at least one airflow duct and the arm chambers formed by the arms in a closed configuration, air delivery to the hair is enhanced, allowing the hair to be dried / styled quickly and easily, and also improving energy efficiency.

[0014] Preferably, one or both of the first arm and the second arm further comprises an airflow guiding structure arranged to receive the airflow from the corresponding duct and guide the airflow from a first direction to a second direction, thereby guiding the airflow into the arm chamber, the first direction being substantially parallel to the length of the corresponding arm, and the second direction being a direction from the corresponding arm towards the opposite arm. The provision of such an airflow guiding structure further enhances air delivery to the hair, further facilitates the drying / styling process, and enables a further improvement in energy efficiency to be achieved.

[0015] In a particular embodiment, each of the first and second arms comprises a respective duct and a respective airflow guiding structure, and the means for delivering the airflow is arranged to deliver air along the duct in each of the first and second arms and subsequently deliver the air through the respective airflow guiding structure and into the inter-arm chamber. This enables air to be delivered to the hair in the device from above and below simultaneously, thereby enhancing the drying / styling process.

[0016] When the first arm and the second arm are in the closed configuration, each airflow guiding structure can deviate from an imaginary centerline located between the first arm and the second arm. This deviation advantageously creates an airflow restriction between the air and the hair when in use to increase the airflow velocity around the hair, thereby speeding up drying. In a specific embodiment, each airflow guiding structure deviates from the imaginary centerline by about 2 mm (i.e., the airflow guiding structures are separated from each other by a distance of about 4 mm).

[0017] The duct in the or each arm may advantageously act as a plenum through which air flows into the respective airflow guiding structure and thence into the inter-arm chamber. This promotes uniformity of airflow from the or each arm through the respective airflow guiding structure and into the inter-arm chamber.

[0018] Preferably, the airflow directing structure in the or each arm comprises a cellular structure configured to direct airflow from a first direction to a second direction, the cellular structure comprising a plurality of cell walls extending into the respective plenum in the second direction.

[0019] The depth of the cells into the corresponding plenum chamber may gradually increase with increasing distance along the corresponding arm. This configuration advantageously causes an incoming airflow in a first direction to turn and exit the plenum chamber in a second direction and enter the inter-arm chamber at a uniform airspeed.

[0020] Alternatively or additionally, the diameter of the cells of the air flow guiding structure in the or each arm may taper with increasing distance along the respective arm.This configuration has been found to provide a more even air flow distribution along the air flow guiding structure.

[0021] In a currently preferred embodiment, the cellular structure has a hexagonal (honeycomb) structure. The inventors have found that this is advantageous in maximizing the open area through the guide structure while minimizing the area occupied by the cell walls, and thereby minimizing the airflow resistance caused by the cell walls.

[0022] The or each airflow directing structure may further comprise a plurality of airflow redirecting channels configured to direct the airflow from the second direction to third and fourth directions, the third and fourth directions being directions outwards from the device and substantially perpendicular to the length of the arms. By exhausting air in these third and fourth directions, the air can be easily directed towards the roots of the hair, thereby drying the roots and enabling root lift to be produced.

[0023] In a presently preferred embodiment, the airflow redirection channels extend between longitudinal edges and corresponding longitudinal sides of the airflow guiding structure.

[0024] The device may further comprise mutually opposing plates arranged on the first arm and the second arm, the mutually opposing plates being arranged to be brought together when the first arm and the second arm are in a closed configuration. More particularly, the first plate and the second plate may be arranged on the first arm, and the corresponding opposing first plate and second plate may be arranged on the second arm. At least one of the plates may comprise means for applying heat to a section of hair when the first arm and the second arm are in the closed configuration, in use, thereby facilitating the drying / styling process.

[0025] An airflow duct extending behind the first plate and the second plate of the corresponding arm can be arranged to receive air from the airflow redirection channel and guide the airflow behind the first plate and guide the airflow to flow outward substantially in a third direction through the vents along the edge of the device, and guide the airflow behind the second plate and guide the airflow to flow outward substantially in a fourth direction through the vents along the edge of the device.

[0026] In certain embodiments, the airflow guiding structure including the cellular structure and the airflow redirecting channels and the outward vents along the third direction and the fourth direction may be formed as an integral structure (eg, by 3D printing).

[0027] Advantageously, the outward vents may be oriented at an angle of approximately 45° relative to the plane of the panel to enhance the degree of root lift produced.

[0028] The apparatus may further comprise an airflow separator arranged to separate the airflow in the first direction into ducts within the first arm and the second arm. Optionally, the airflow separator may comprise a flexible member.

[0029] The means for delivering the air flow may comprise a fan. The fan may advantageously comprise a brushless motor designed to operate at high speed (e.g. in excess of 30,000 revolutions per minute) and low power (e.g. 15 W maximum, 3 W during normal operation) and may be driven by a DC power supply. Such high speed and low power parameters of the fan have been found to provide excellent drying performance, drying hair as quickly as a 2000 W conventional hair dryer, but using significantly less power.

[0030] Presently preferred embodiments further comprise means for heating the air flow, such as one or more heating elements or electrical heating coils, for example.

[0031] Advantageously, the apparatus may further comprise an airflow separator arranged to direct the incoming airflow towards the heating coils to thereby improve the efficiency of heat transfer from the coils to the incoming airflow during use.For example, the airflow separator may have a tapered or conical shape.

[0032] Furthermore, the device may further comprise means for performing pulse width modulation of the electrical power applied to said means for heating said air flow. This may advantageously be used to regulate the heat output of the heating means despite variations in the supply voltage (e.g. caused by local variations in the voltage of the worldwide power grid).

[0033] To promote a generally uniform air temperature distribution throughout the airflow, the apparatus may further include means for inducing turbulence (such as one or more baffles within the airflow, or a conical or tapered airflow mixing member) that induces turbulence in the heated airflow before it reaches the inter-arm chamber. Alternatively, the means for heating the airflow may include an airflow directing structure formed of a material that generates heat when an electric current is applied thereto.

[0034] Optionally, the device may further comprise one or more sets of flexible bristles on the first arm and / or the second arm, outside or inside the arm chamber, the flexible bristles being arranged to promote application of uniform tension to the hair passing through the arm chamber in use.

[0035] Advantageously, to prevent air from escaping through the end of each of the first and second arms, the device may further comprise mutually opposed spring-loaded sealing elements at the distal extremities of said arms.

[0036] Furthermore, the device may further comprise at least one airflow deflector located on the outer surface of at least one of the arms, the airflow deflector being shaped and positioned to deflect any rearwardly flowing escaping air away from the user's hands. Such an airflow deflector may advantageously be ramp-shaped.

[0037] According to a second aspect of the present disclosure, there is provided a method of drying hair using the device of the first aspect.

[0038] The method may further comprise using the device described above to style the hair substantially simultaneously with drying the hair. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The following will be combined with the accompanying drawings to illustrate the embodiments of the present disclosure by way of example only. In the accompanying drawings:

[0040] Figure 1 is a perspective view of a combined hair dryer / styler apparatus including means for blowing and heating air, an air flow separator, and mutually opposing drying / styling arms in an open configuration, wherein each arm includes an air flow directing structure and a pair of heating plates, respectively;

[0041] Figure 2 The arms are shown in a closed configuration. Figure 1 equipment;

[0042] Figure 3 Shows the use of Figure 1 equipment;

[0043] Figure 4 yes Figure 1 A longitudinal perspective cross-sectional view of a device of FIG. 1 showing some exemplary internal components;

[0044] Figure 5 yes Figure 1 A longitudinal plane cross-sectional view of the device;

[0045] Figure 6 yes Figure 1 A close-up perspective view of an arm of a device of FIG. 1 in an open configuration;

[0046] Figure 7 yes Figure 1 A side cross-sectional view through an airflow directing structure of an apparatus of the invention when the arms are in an open configuration, showing that the airflow directing structure of each arm has a cellular structure, wherein the depth of the cells gradually increases with increasing distance along the respective arm;

[0047] Figure 8 Yes Figure 7 a side cross-sectional view shown, but with the arms in a closed configuration, and also showing the direction of airflow along and between the arms;

[0048] Fig. 9 yes Figure 1 A perspective view of an arm of a device of the type shown, the arm being closed around a plurality of wet strands of hair;

[0049] Fig.10 It is through the closed structure Figure 1A transverse cross-sectional view of an arm of the device, and also showing the direction of airflow;

[0050] Fig.11 is corresponding to Fig.10 A transverse cross-sectional view through the arms of the device in a closed configuration (around the hair) and showing more details;

[0051] Fig.12 It is in a closed structure around the hair. Figure 1 A longitudinal perspective cross-sectional view of the arms of the device showing the change in airflow direction caused by the airflow guiding structure in each arm;

[0052] Fig.13 It passes through a closed structure around the hair. Figure 1 A transverse perspective cross-sectional view of an arm of the device, again showing the change in airflow direction;

[0053] Fig.14 There is no board Figure 1 A perspective view of an arm member of the device, again showing the change in airflow direction;

[0054] Fig.15 yes Fig.14 a perspective longitudinal section of the arm member shown, again showing an airflow guide structure with a cellular structure (with hexagonal cells), wherein the depth of the cells increases gradually with increasing distance along the respective structure;

[0055] Fig.16 is a longitudinal perspective cross-sectional view of an alternative embodiment of a cellular airflow guide structure, in this case having rectangular cells in one linear dimension (the depth of the cells also increasing with increasing distance along the respective structure);

[0056] Fig.17 is a longitudinal perspective cross-sectional view of another alternative embodiment of a cellular airflow guide structure, in this case having rectangular cells in two linear dimensions (the depth of the cells also increasing with increasing distance along the respective structure);

[0057] Fig.18 yes Figures 1 to 15 A longitudinal perspective cross-sectional close-up of an air flow separator of an apparatus of FIG. 1 , and also showing a plurality of baffles and a diffuser grille;

[0058] Fig.19 is part Figure 1 Another view of the device, showing in particular the plurality of baffles between the fan and the arm;

[0059] Fig. 20 It is a graph of the relationship between hair sample temperature and drying time, which helps to understand the background principle;

[0060] Fig.21 is a plan view of an example of an arm member, wherein the cell diameters of the airflow guiding structure are equal;

[0061] Fig. 22 Shown along Fig.21 airflow distribution along the length of the airflow guiding structure;

[0062] Fig.23 is a plan view of another example of an arm member, wherein the diameter of a cell of an airflow directing structure decreases along the structure;

[0063] Fig.24 Shown along Fig.23 airflow distribution along the length of the airflow guiding structure;

[0064] Fig.25 Provided by way of example only Fig.23 Exemplary dimensions of the hexagonal cells of the airflow directing structure;

[0065] Fig.26 is a side cross-sectional view of an example of an arm member in which heated air and cool air are not mixed before reaching the airflow directing structure;

[0066] Fig. 27 is a side cross-sectional view of another example of an arm member, wherein heated air and cold air pass through an air flow mixer before reaching an air flow directing structure;

[0067] Fig.28 is a perspective view of a heater assembly having an air flow mixer (in the form of an air flow splitter) at the center;

[0068] Fig.29 yes Fig.28 A lateral plan view of a heater assembly;

[0069] Fig.30 It is through the closed structure Figure 1 A transverse cross-sectional view of an arm of a variant of the device and showing the direction of airflow (airflow originating from one arm only);

[0070] Fig.31 is a perspective view of a sealing element at one end of an arm of a variation of the disclosed apparatus;

[0071] Fig.32 is a side cross-sectional view of two opposing arms of a combined hair dryer / styler device in a closed configuration, wherein each arm has a Fig.31 The sealing elements shown, the sealing elements meet to prevent air from escaping from the ends of the device;

[0072] Fig.33is a side cross-sectional view of two opposing arms of a combination hair dryer / styler device, with a ramp feature behind a heating plate on one arm (in this case, the upper arm) to deflect airflow away from a user's hands;

[0073] Fig.34 yes Fig.33 Close-up perspective view of the slope features;

[0074] Fig.35 is a side cross-sectional view of an air heater of a combination hair dryer / styler device, showing (with solid black fill on the left side of the figure) Fig. 27 and Fig.28 An air flow mixer (air flow separator) is shown to mix the air before it reaches the air flow guiding structure; and an initial air flow separator is shown (using solid black fill on the right side of the figure) to guide the incoming air flow towards the heating coil of the device;

[0075] Fig.36 Shown with Fig.35 a graph of the internal air temperature versus time in the area of ​​the thermostat (lower line) and thermal cutoff (upper line) in the device associated with the device, spanning the point at which the device switches from on to off and the internal fan stops; and

[0076] Fig.37 By comparison, it is shown that in the absence Fig.35 The initial air flow separator case is Fig.36 The corresponding curve graph.

[0077] In the drawings, like elements are always denoted by like reference numerals. DETAILED DESCRIPTION

[0078] The disclosed embodiments represent the best ways known to the applicant to put the present disclosure into practice. However, these ways are not the only ways to implement the present disclosure.

[0079] Combination Hair Dryer / Styler Equipment Overview

[0080] Figure 1 is a perspective view of the combined hair dryer / styler device 10 according to the first embodiment, wherein the arms 14, 16 are in an open configuration, and Figure 2 The same device is shown with the arms 14, 16 closed (in use, e.g. Figure 3 shown). Figures 4 to 15 Further views of parts of the device 10 are shown, and Figures 8 to 14 The parts of the device are shown when in use.

[0081] First reference Figure 1 and Figure 2, device 10 is an all-in-one handheld device that can be used to quickly and easily dry hair while also being able to style (fix) the hair (e.g., straighten the hair, or add "volume" to the hair).

[0082] The device 10 includes a main body 12, and first and second arms 14, 16 that are opposed to each other and are arranged in a manner generally similar to the arms of a handheld hair styling tool. The first and second arms 14, 16 are adapted to be in an open configuration (e.g., Figure 1 as shown) and closed structures (as Figure 2 The open configuration is used to receive a section of wet hair between the two arms, and the closed configuration is adjacent to the hair to generate tension in the hair, so that when in use, when the arms 14, 16 are in the closed configuration, the arms 14, 16 form an inter-arm air chamber (13, Fig.10 ).

[0083] Temporarily go to Figure 7 , the first airflow conduit 15 is disposed within and along the first arm 14, and the second airflow conduit 17 is disposed within and along the second arm 16. In an alternative embodiment (e.g., Fig. 27 , Fig.30 and Fig.35 ), only one arm may contain such an airflow duct.

[0084] See also Figure 4 and Figure 5 The device further comprises a fan assembly 38 in the main body 12 for conveying airflow along the first duct 15 in the first arm 14 and the second duct 17 in the second arm 16. The fan assembly 38 has an impeller and is usually also provided with a filter.

[0085] For example, Figure 1 , Figure 4 , Figure 5 , Figure 7 , Figure 8 As shown, each of the first arm 14 and the second arm 16 further includes a corresponding airflow guiding structure 24, which is arranged to receive airflow from the corresponding first duct 15 or the second duct 17 and direct the airflow in a first direction (D1, D2) substantially parallel to the length of the corresponding arm. Figure 8 ) (i.e. the incoming air is longitudinally along the device) is directed (i.e. diverted) to a second direction (D2, Figure 8), i.e. inwardly into the inter-arm plenum 13 formed by the first arm 14 and the second arm 16 in the closed position. In an alternative embodiment, if only one arm contains an airflow duct, only one of the arms 14, 16 may be provided with such an airflow guiding structure 24. The construction and function of the airflow guiding structure 24 will be described in more detail below. In other variations, the (multiple) airflow guiding structures 24 may be omitted entirely.

[0086] For example, Figure 1 As shown, the first arm 14 is a continuation of the main body 12, and the second arm 16 is connected to the main body 12 by a hinge 18, and the first arm 14 and the second arm 16 can move relative to each other (in the embodiment shown, by moving the second arm 16 toward the first arm 14) through the hinge 18. Therefore, when in use, the user can bring the first arm 14 and the second arm 16 together so as to be in a closed configuration (such as Figure 2 ), or moved apart so as to be in an open configuration (as shown Figure 1 In the illustrated embodiment, each of the arms 14, 16 is widened relative to the main body 12 to form a "head" of the device 10 remote from the main body 12, although other embodiments are possible in which the head is not widened in the manner shown.

[0087] The hinge 18 may comprise any suitable device to allow the first arm 14 and the second arm 16 to move relative to each other.

[0088] Preferably, the hinge 18 also includes a spring device configured to bias the first arm 14 and the second arm 16 into an open configuration, such that a user needs to apply pressure to the arms to close them together (overcoming the action of the spring device), and such that once the pressure is removed, the arms 14, 16 automatically open under the action of the spring device. For example, the hinge 18 may include a leaf spring or a coil spring.

[0089] The hinge 18 and the spring means may be the same component. For example, the spring means itself may be used to couple the second arm 16 to the main body 12, thereby avoiding the need to provide a separate mechanical hinge and simplifying the overall construction of the device.

[0090] like Figure 1 and Figure 6 As shown in a close-up of FIG. 1 , in the illustrated embodiment, the inner surface of the first arm 14 includes a first elongated heating plate 20a and a second elongated heating plate 20b that are parallel to each other and to the length of the arm 14. The second arm 16 also includes a first elongated heating plate 22a and a second elongated heating plate 22b at positions corresponding to the heating plates 20a and 20b (at Figure 1 and Figure 6 is not visible in , but for example in Fig.10 and Fig.11Each heating plate is provided with a respective electric heating element operable to heat the respective heating plate. In the embodiment shown, the operating temperature of the heating plates is typically about 120°C to 130°C.

[0091] The first and second arms 14, 16 and the first and second heating plates on each arm are arranged so that, when the device 10 is in the closed configuration, the first and second heating plates 20a, 20b of the first arm 14 are in contact with the first and second heating plates 22a, 22b of the second arm 16. Preferably, the heating plates 20a, 20b, 20c, 20d are made of a material having a relatively high thermal conductivity, and are preferably provided with one or more temperature sensors (e.g., a temperature sensor for each plate, or one or more temperature sensors serving a plurality of heating plates, respectively).

[0092] Optionally, flexible bristles can be arranged beside the heating plates 20a, 20b, 20c, 20d. More particularly, the flexible bristles can be positioned on either or both sides of the first arm 14, and / or on either or both sides of the second arm 16, adjacent to the inlet / outlet where the hair enters / leaves the heating plates 20a, 20b, 20c, 20d. Alternatively or additionally, the flexible bristles can be arranged in or around the airflow guiding structure 24, between the heating plates. Such bristles enable a more uniform tension to be applied to the hair fibers in the hair section passing through the chamber 13 formed by the arms 14, 16 in the closed position.

[0093] like Figure 1 As shown, a control button or switch 23 may be provided on the device 10 so that it can be turned on or off together with an indicator light to indicate whether the power is on. When the device 10 is turned on and ready to be used, a sound may also be played by a sound generator (not shown).

[0094] like Figure 4 and Figure 5 As shown in the cross-sectional view of FIG, the fan assembly 38 is mounted toward the end of the main body 12 away from the first arm 14. The fan 38 driven by the motor is operable to draw air from the surrounding environment and convey an airflow along the interior of the main body 12; and then the airflow enters and is conveyed along the ducts 15, 17 in the arms 14, 16; and then the airflow enters and passes through the inter-arm plenum 13 formed by the arms 14, 16 in the closed position, around and through the hair to be dried.

[0095] Advantageously, the fan 38 may comprise a brushless motor designed to operate at high speed (e.g., in excess of 30,000 revolutions per minute) and low power (e.g., 15 W maximum, 3 W during normal operation), and may be driven by a DC power supply. It has been found that such high speed, low power parameters of the fan provide excellent drying performance, drying hair as quickly as a 2000 W conventional hair dryer, but using significantly less power.

[0096] In the part 30 towards the end of the main body 12 proximate the first arm 14 , an electric heating coil (or other electric heating element) is provided which is operable to heat the air drawn in by the fan 38 .

[0097] The heating plates 20a, 20b, 22a, 22b serve multiple purposes during use of the device 10. Firstly, a user clamps a section of wet hair between the opposing plates 20a and 22a and between the opposing plates 20b and 22b (i.e., transversely across the plenum 13 formed by the first arm 14 and the second arm 16 in the closed configuration), and by pulling the device along the section of wet hair, the heating plates 20a, 20b, 22a, 22b subject the wet hair to a scraping action, removing excess unbound water, and also heating the hair to accelerate subsequent evaporation of the water. Secondly, the heating provided by the heating plates 20a, 20b, 22a, 22b causes the walls of the plenum 13 to be heated (by thermal conduction), and also helps to maintain the temperature of the airflow delivered through the plenum 13 by the fan 38. Thirdly, the heating plates 20a, 20b, 22a, 22b can be used to style the hair as an integral part of the drying process.

[0098] Preferably, the heating plates 20a, 20b, 22a, 22b are configured as ceramic floating plates with springs having a low spring rate or low stiffness, thereby providing good control of hair tension.

[0099] Taking into account the airflow heating coil (or other heating element) and the heating plates 20a, 20b, 22a, 22b and the fan 38, the total power consumption of the device 10 is about 600W to 800W, which is significantly less than the 2000W of a conventional hair dryer.

[0100] like Figure 4 and Figure 5As shown, the electrical and electronic circuitry of the device 10 is housed within the main body 12 and the first and second arms 14, 16 (although primarily within the main body 12 and first arm 14). In the example shown, the printed circuit board assembly 36 is disposed within the main body 12. Power is provided to the device 10 by a power source located at the end of the main body 12 remote from the first arm 14. In the embodiment shown, the power source is an AC mains power source. However, in alternative embodiments, the power source may include one or more DC batteries or battery cells (which may be rechargeable, for example, rechargeable from the mains or from a DC power source via a charging lead), thereby enabling the device 10 to be a cordless product.

[0101] The circuit board assembly 36 includes four TRIACs 37, each TRIAC being used to power a corresponding one of the heating plates 20a, 20b, 22a, 22b.

[0102] Airflow guidance

[0103] The device 10 includes a number of features that direct airflow from the fan 38 to the user's hair 11, thereby enabling the hair to be dried and styled. Figures 7 to 15 Describe these features in detail.

[0104] As mentioned above, and for example Figure 7 As shown, in the illustrated embodiment, each of the first arm 14 and the second arm 16 (at the head of the device 10 away from the main body 12) includes a cellular airflow guide structure 24 in airflow communication with the corresponding first duct 15 or second duct 17. The first duct 15 and the second duct 17 serve as plenums to supply air through the guide structure 24 of each of the first arm 14 and the second arm 16.

[0105] The air is supplied to the first duct 15 and the second duct 17 via the columnar component 30 under the action of the fan 38. The component 30 includes a heating element for heating the air, and Fig.18 A set of elongated baffles 32 (at multiple angles in the cross-sectional view, essentially star-shaped), air flow separators 34 and diffuser grilles 31 are shown in close-up.

[0106] The elongated baffle 32 is arranged to mix the air to reduce hot spots from the heater in the area between the inlet of the air heater and the outlet of the cellular airflow guide structure 24. This is important for achieving a uniform air temperature at the outlet of the cellular airflow guide structure 24, and thus achieving uniform drying over the entire hair section in the chamber 13. It can also prevent the formation of hot spots in the air that may damage the hair. Therefore, in the absence of such a baffle, it may be necessary to reduce the hair heating power and therefore reduce the drying speed of the device.

[0107] The airflow separator 34 is aligned across the diameter of the cylindrical member 30 and is arranged to separate the incoming airflow into separate upper and lower airflows that are fed directly into the first and second ducts 15, 17. Advantageously, the shape of the airflow separator 34 allows air to be directed into the first and second ducts 15, 17 without causing a whistling sound of the air, thereby providing an acoustic benefit.

[0108] More specifically, the component 30 has a circular cross section, the lower half of which (located below the airflow separator 34) corresponds to the cross-sectional geometry of the first duct 15. The upper half of the component 30 (located above the airflow separator 34) corresponds to the cross-sectional geometry of the second duct 17. Figure 8 As shown in the cross-section in FIG. 1 , when the second arm 16 is in the closed position, the second duct 17 fits tightly around the upper half of the component 30 so that the airflow can pass through the component 30 below and above the airflow separator 34 and enter the first duct 15 and the second duct 17 without leakage.

[0109] Therefore, if Figure 8 As shown, air enters the first duct 15 and the second duct 17 along a first direction D1 that is substantially parallel to the length of each of the first arm 14 and the second arm 16 .

[0110] Likewise Figure 8 As shown, and as Fig.15 As shown in the longitudinal perspective section of FIG. 1 , the airflow guide structure 24 within each of the first arm 14 and the second arm 16 includes a lattice structure having a plurality of cell walls. In the illustrated embodiment, the lattice structure has a hexagonal (honeycomb) structure, although this geometry is not required and other geometries (e.g., such as Fig.16 and Fig.17 ). However, it has been found that a hexagonal (honeycomb) structure is advantageous for maximizing the open area through the guide structure 24 while minimizing the area occupied by the cell walls and thereby minimizing the airflow resistance caused by the cell walls. In the embodiment shown, the cell width is approximately one-tenth of the cell length.

[0111] It should be noted that the depth of the cells of the airflow directing structure 24 into the respective ducts / plenums 15, 17 gradually increases with increasing distance along the respective arms 14, 16 towards the distal end of the device in a direction away from the hinge 18. With this arrangement, air entering along the first direction D1 is turned from the first direction D1 to a second direction D2 substantially perpendicular to the first direction D1, flowing inwardly towards the inter-arm chamber 13 formed by the arms 14, 16 in the closed position.

[0112] More particularly, the gradual change in the depth of the cells of the airflow directing structure 24 into the respective plenum chambers 15, 17 advantageously causes the incoming airflow in direction D1 to turn and exit the plenum chambers in direction D2 and enter the inter-arm chamber 13 at a uniform airspeed.

[0113] Figure 8 It is also shown that when the arms 14, 16 are in the closed position, the inner surface of each airflow directing structure 24 is offset by a distance of 0.5 mm to 4 mm (preferably about 2 mm) relative to an imaginary centerline between the first arm 14 and the second arm 16. The location of the imaginary centerline is the location where the hair 11 will cross the arm chamber 13 under tension when in use (e.g., as shown in FIG. Fig. 9 ). This deviation of each airflow guide structure 24 relative to the imaginary center line advantageously creates an airflow restriction between the air and the hair when in use to increase the airflow speed around the hair, thereby accelerating drying.

[0114] like Fig.14 As best shown in the drawings, the airflow directing structure 24 also includes a plurality of airflow redirecting channels 28 extending between the longitudinal edges and the corresponding longitudinal sides of the airflow directing structure 24. These channels 28 are configured to direct the airflow from the second direction D2 to a third direction D3 and a fourth direction D4, which are directions outward from the device and substantially perpendicular to the length of the arms 14, 16, the fourth direction D4 being opposite to the third direction D3. Fig.13 Also shown are the airflow directions D3 and D4. Fig.14 As shown, the airflow guiding structure 24 including the lattice (eg honeycomb) structure and the airflow redirecting channel 28, and the outward vents 26 in the third direction D3 and the fourth direction D4, can be integrally formed into a whole structure, for example, by 3D printing.

[0115] Now turn to Fig.10 , showing other directions of airflow through the arms 14, 16 of the device 10 when viewed in transverse cross-section facing the main body 12 of the device.

[0116] from Fig.10 Starting from the center of the arm, it can be seen that the air flowing in the direction D2 enters the inter-arm chamber 13 from the plenum chambers 15 , 17 via the cells of the airflow guide structure 24 .

[0117] The air then diffuses laterally and enters the airflow redirection channel 28, then passes along the airflow ducts 19a, 19b, 21a and 21b, and leaves the device through the vent 26 in opposite directions D3 (through ducts 19a and 21a) and D4 (through ducts 19b and 21b). Fig.10As shown, the airflow ducts 19a, 19b, 21a and 21b extend behind the heating plates 20a, 20b, 22a and 22b mounted on the first arm 14 and the second arm 16, respectively.

[0118] For the sake of completeness, it should be noted that while the airflow directions D3 and D4 when leaving the vent 26 can be said to be "substantially perpendicular" to the length of the arms 14, 16, the overall path followed by the air as it passes through the airflow redirection channel 28 and flows along the airflow ducts 19a, 19b, 21a and 21b and then through the vent 26 is not a linear path.

[0119] Advantageously, the vents 26 direct the outflowing air towards the roots of the hair to dry the roots and create a root lift.

[0120] Fig.11 is corresponding to Fig.10 A transverse cross-sectional view of the device 10 with arms 14, 16 in a closed configuration (around hair 11) and facing the main body 12 of the device. Looking along channels 15 and 17 towards the main body 12, features of the columnar member 30 can be seen, including a diffuser grille 31 and an elongated baffle 32 at the end. Fig.11 The other characteristics of Fig.10 Those features identified in and described above.

[0121] Fig.12 and Fig.13 The change in airflow direction due to the airflow directing structure 24 of the apparatus 10 and other features in each arm 14, 16 is shown (in longitudinal and transverse cross-sectional perspectives, respectively).

[0122] As described above, the first airflow direction D1 is substantially parallel to the length of each of the first arm 14 and the second arm 16 as the air passes through the baffle 32 and enters the first and second ducts (plenums) 15, 17 in the respective first and second arms 14, 16. The cellular airflow guide structure 24 then guides (i.e., turns) the airflow inwardly from the first direction D1 to the second direction D2, inwardly into the inter-arm chamber 13 formed by the arms 14, 16 in the closed position, through which the hair 11 passes during use.

[0123] The air then diffuses laterally and enters the airflow redirection channel 28 before passing along the airflow ducts 19a, 19b, 21a and 21b behind the heating plate and exiting the device via the vents 26 in opposite directions D3 and D4.

[0124] Technical principle

[0125] As used herein, the expressions "to dry the hair", "drying the hair" and the like are to be understood as referring primarily to the removal of "unbound" water present on the outside of the hair when wetted. This "unbound" water should be contrasted with "bound" water, which is present inside individual hair strands and which can interact with the hair when the hair is thermally styled. In the context of the present disclosure, when drying the hair, this "bound" water need not be removed, although some bound water may be removed during the drying process. Bound water is typically further removed during the styling process.

[0126] Fig. 20 is a graph of the relationship between hair sample temperature and drying time, which helps to understand the technical principles related to this study. As described below, as the hair temperature increases, the hair undergoes a preheating period, and then undergoes a first drying period and a second drying period. The first drying period mainly involves removing unbound water, and the second drying period mainly involves removing bound water.

[0127] "Preheating period": During this phase, the ceramic heating plate is used to raise the temperature of the hair to the temperature at which the liquid phase transition occurs during the drying period (point A to B). The plate surface cannot be operated at a temperature of 100°C to 135°C (nominal 120°C) before water cavitation (hissing sound) occurs on the plate.

[0128] "Drying period 1": This phase is supported by heated airflow to dry the unbound water on the hair (points B to C). Without the newly heated airflow to support evaporation, the hair will cool quickly and the drying rate will slow down.

[0129] • "Drying phase 2": This phase (points C to E) occurs when the bound water on the hair evaporates and is driven out from the hair fiber.

[0130] Styling / straightening can be achieved when force is applied to the fibers and bound and unbound water is driven off.

[0131] Problem and solution provided by this study

[0132] In this study, the inventors considered the following problems (and others) and provided the following solutions:

[0133] Problem 1 - Reduce fan airflow and air heating power to fit in the user's hand

[0134] The inventors have determined that drying hair with heated air is generally an inefficient use of energy, despite the fact that conventional hair dryer technology is highly efficient in converting electrical energy into high temperature airflow. Furthermore, using heated air alone to dry hair is highly inefficient, with most of the energy being dissipated from the heated air into the atmosphere. In order to dry hair faster, conventional hair dryers utilize air heating to increase the drying rate by using increasingly high speed motors and fan technology, using higher air pressures and larger volume flows. However, this results in reduced energy efficiency, increased unit costs and increased noise levels.

[0135] On the other hand, the use of conductive heating plates is a very efficient way to heat the water and the hair to be dried, contributing to a fast drying, compact and quiet product. However, at temperatures between ˜100° C. and 143° C. (nominal), liquid water in contact with the metal plate causes audible cavitation sounds (hissing), which leads to the perception of damage. Hair temperatures exceeding 143° C. may result in hair denaturation.

[0136] One possible solution to this is to incorporate heated air blowing across a conductive heating plate, but this creates very high airflow resistance, which presents additional challenges. Therefore, inefficient high-speed motor technology will be required to achieve the airflow pressure required to move the hair through the hair and plate).

[0137] The solution provided by this study is to enclose the hair in a heated air plenum 13 between the conductive heating plates 20a, 20b, 22a, 22b. This enables the hair to be effectively heated to evaporate faster towards the phase change temperature of water at a plate temperature of ˜100° C. to 143° C. (nominal 120° C.), thereby avoiding cavitation and damage. In addition, the heated plenum temperature of 125° C. to 175° C. (nominal 150° C.) enables the phase change and evaporation to be effectively supported and maintained without cavitation.

[0138] Problem 2 - Minimizing the air temperature range and air heating power due to large variations in hair airflow resistance

[0139] The inventors have determined that hair, especially wet hair, has large variations in airflow resistance depending on the size and moisture content of the segments. Therefore, a solution is needed to avoid excessive temperature rise (hair damage) and large variations in air heater power and fan pressure requirements.

[0140] The solution provided by this study is that the plenum 13 enclosed around the hair allows the heated air to pass around the hair (not just through the hair section), thereby reducing the airflow resistance range of the system. This helps to reduce the heater power and power requirement range for regulating the air temperature, thereby improving energy efficiency and reducing product size and cost.

[0141] This helps improve fan energy efficiency, reduces sound and cost by lowering the resistance range of the system's airflow requirements, thereby enabling the use of lower speed motors / fans.

[0142] Additionally, by designing the system resistance to precisely meet the airflow and temperature requirements for drying hair when closed, the air temperature is lower when the product is open, which helps improve the user's drying experience and reduce energy loss, and reduces the physical size of the air heater, which would otherwise make the product larger and less convenient to use.

[0143] Problem 3 - Achieving uniform air velocity and changing air direction at the hair-air interface

[0144] The inventors have determined that achieving uniform air temperature and velocity across the hair-air interface is beneficial to maintaining drying efficiency. However, achieving this in the context of the present product form requires a method of diverting air at a uniform air velocity and pressure at the hair-air interface.

[0145] The solution provided by this study is to set up an airflow path that includes various features for directing or turning the airflow, including:

[0146] An airflow separator 34 that separates the airflow to the first arm 14 and the second arm 16. The airflow separator 34 also prevents excessive or uneven temperature rise at the edge of the segment. It should be noted that the airflow separator 34 can also be made larger and made of a flexible material to exhaust air to the second arm 16 when the device is in the open state. This prevents the air from blowing hair away from the heating plates 20a, 20b, 22a, 22b when the device is in the open state, and prevents hair from restricting the air outlet in the open state, resulting in airflow restriction and increased resistance in the system, which may otherwise cause overheating and hair damage.

[0147] • A plenum 15, 17 in each arm 14, 16, the plenum 15, 17 being shaped to allow airflow to fill each arm 14, 16, thereby making the airflow out of the cells of the cellular airflow guiding structure 24 more uniform.

[0148] A cellular airflow guiding structure 24, the cross-sectional width of which is reduced relative to the width of the arms 14, 16 in which it is located.

[0149] An airflow directing structure 24 in each arm 14, 16, the airflow directing structure 24 having a cellular (e.g. honeycomb or louvered) structure extending into the plenum 15, 17 in the respective arm, wherein the depth of the cells increases in depth from the end of the arm proximal to the hinge 18 to the end of the arm distal to the hinge 18. This gradual change in cell depth causes the airflow to turn toward and exit from the plenum 15, 17 at a uniform airspeed.

[0150] An open offset distance of 0.5 mm to 4 mm (nominal 2 mm) from the nozzle outlet of the airflow directing structure 24 to the hair (when the first and second arms are in a closed configuration) to create an airflow restriction between the air and the hair to increase the airflow velocity around the hair, thereby speeding up drying. The open cross-section between these features allows air to pass around the hair to the plenum outlet without having to pass through the hair (which might otherwise restrict airflow).

[0151] Problem 4 - Achieving Uniform Air Temperature in an Airstream

[0152] The inventors have determined that if the air heater windings are placed on the outer periphery of the air duct (as is conventionally done), it may be difficult to achieve uniform air temperature throughout the airflow. This results in the air temperature at the periphery of the airflow being higher relative to the air temperature in the center of the airflow, resulting in an uneven heat distribution throughout the airflow.

[0153] The solution provided by this research is to place features such as baffles 32 in the airflow outside the ring at the heater outlet, or inside the airflow, to induce turbulence in the heated airflow and promote better mixing of the air in the airflow before passing through the airflow separator 34. As a result, a more uniform air temperature distribution throughout the airflow can be achieved.

[0154] Problem 5 – Drying the hair roots and creating root lift

[0155] The inventors have determined that, for example, to create a root lift, it is desirable to dry the hair at the root.

[0156] The solution provided by the present study is to provide air outlet vents 26 on the sides and / or rear of the conductive heating plates 20a, 20b, 22a, 22b. These vents 26 direct the outflowing air towards the roots of the hair to dry the roots and create a root lift.

[0157] Problem 6 - Plate cavitation (hissing) limits for very wet hair at around 100°C to 125°C

[0158] The present inventors have determined that plate cavitation (hissing) of very wet hair at around 100°C to 125°C limits the drying rate.

[0159] The solution provided by this research is based on the recognition that as the unbound water on the hair evaporates, the plate temperature can be increased to a higher temperature to heat and dry the hair faster and more efficiently.

[0160] Thus, a method is provided to measure the level of unbound water on the hair (moisture sensing), so that the plate and / or air temperature can be increased to further speed up the drying rate. This can be achieved by providing a temperature sensor in the device 10, for example, at the following locations:

[0161] Position "A" - Upstream of the air-hair interface

[0162] Position "B" - Downstream of the air-hair interface

[0163] Position "C" - Sensing temperature of conductive heating plate, and / or power sensing

[0164] A very large temperature difference between these sensors would indicate that the arms 14, 16 are open since air would not be directed through position B. The open state of the arms 14, 16 can also be sensed by measuring the electrical power required to raise the air temperature since the airflow system resistance will also vary between the open, closed and hair-closed states.

[0165] Thermal loading of the plate at position C would indicate hair in the product (from power and / or temperature sensing).

[0166] A high temperature difference between the sensors will indicate that water is evaporating (drying the hair), so the hair is wet. On the other hand, a low temperature difference between the plates will indicate that minimal phase change is occurring, so the hair is "dry".

[0167] Problem 7 - Improving the Cooling Rate of the Heating Plate

[0168] As described above, the inventors have determined that increasing the heating plate temperature in response to the presence of unbound water in the hair can achieve faster drying. However, if the user moves the device to a wetter hair section, it is ideal to cool the product plates very quickly to prevent cavitation (hissing) and / or hair damage.

[0169] This study provides a solution to this problem based on actively cooling the heating plate with air (from a fan) passing over it. This enables accelerated cooling of the plate back to 100°C to 125°C. The air temperature can be controlled, for example, using an NTC (negative temperature coefficient) device and TRIAC control of the air heater.

[0170] A PTC (positive temperature coefficient) heater may also be beneficial to achieve a simple and compact conduction heater with an air heat sink.

[0171] Problem 8 - Regulating the temperature of the air that contacts the hair in the open position

[0172] The inventors have determined that it may be advantageous to regulate the maximum temperature rise of the hair to prevent hair damage, and / or to minimize energy losses dissipated to the atmosphere, thereby delivering cooler feeling air to the user when the air outlet is restricted by the hair during loading. It is also desirable to regulate the air temperature to achieve fast drying and minimal hair damage.

[0173] The solution provided by this study is to place an NTC (negative temperature coefficient) device at the outlet of the air heater, between the air heater and the hair contact surface, with the preferred location closest to the hair interface at the outlet nozzle. This enables the NTC to respond to changes in airflow resistance caused by hair restriction, or to increases in temperature differences caused by increased airflow resistance when the arms are opened. If the upper temperature limit is reached, TRIAC control can be used to adjust the power provided to the air heater.

[0174] Problem 9 - Refreshing your hair without washing it

[0175] The present inventors have determined that a user may desire the feeling of a freshly washed and dried hair when they do not have the time, ability or inclination to wash and dry the hair.

[0176] The solution provided by this study is to allow the fragrance to be emitted into the airflow generated by the device 10, thereby giving the hair a fresh smell. To achieve this, a user-replaceable piezoelectric atomizer and / or a simpler fragrance reservoir and wick can be used to achieve a phase exchange (liquid to gas) into the airflow and thereby reach the user's hair.

[0177] Problem 10 - Manufacturing a compact air heater to produce a compact overall product form

[0178] The inventors have determined that mains powered electric air heaters are typically heated wire resistors formed to maximise the heated surface area in the air stream. This also adds complexity, size and cost due to the need for a thermal fuse.

[0179] The solution provided by this study is to realize that a PTC (positive temperature coefficient) heater can realize a new type of air heater that combines a lattice (e.g., honeycomb) airflow guide structure 24 with an air heater into a single product component. Therefore, this combines the functions of the two parts, making the entire product smaller and more compact. In addition, due to the PTC effect, this can also eliminate the need for an additional thermal fuse (and its associated costs).

[0180] Question 11 – Portability

[0181] The present inventors have determined that consumers desire products suitable for use "on the go", such as away from home, or in any situation away from an electrical outlet (such as in the bathroom).

[0182] With the aforementioned energy savings, the present research enables low voltage (LV) devices 10 to be used for safe operation in bathrooms and / or enables the device 10 to be used cordlessly (eg, with rechargeable batteries) and / or with a compact standalone power source.

[0183] Modifications and Replacements

[0184] Detailed embodiments and some possible alternatives have been described above. As will be appreciated by those skilled in the art, many modifications and other alternatives may be made to the above embodiments while still benefiting from the disclosure embodied therein. Therefore, it should be understood that the disclosure is not limited to the described embodiments and includes modifications that are obvious to those skilled in the art and fall within the scope of the appended claims.

[0185] In the above embodiment, the first arm 14 and the second arm 16 respectively include corresponding airflow ducts 15 and 17, and are provided with corresponding airflow guide structures 24. However, in an alternative embodiment, only one of the arms 14 and 16 may be provided with an airflow duct and an airflow guide structure 24. An example of such a variation will be described below and will be described in detail in the following. Fig. 27 , Fig.30 and Fig.35 In other variations, the airflow directing structure(s) 24 may be omitted entirely.

[0186] In the above-described embodiment, the heating plates are symmetrically arranged on either side of each of the arms 14, 16. However, as will be appreciated by those skilled in the art, both plates need not be heated, and in alternative embodiments, only one plate may be heated, or neither plate may be heated. In some cases, without heating one or both plates, the scraping effect of the plates may be sufficient to dry the hair in combination with the airflow. In addition, the unheated plates may be used to apply tension to the hair to provide a degree of styling. However, it is preferred to have at least one heating plate, as this aids the drying / styling process. In addition, as in the above-described embodiment, the use of a pair of heating plates advantageously allows for bidirectional / two-handed use of the device.

[0187] In the above-described embodiment, the airflow guiding structure 24 of each of the first arm 14 and the second arm 16 includes a lattice structure having hexagonal (honeycomb) cells, which is configured to guide the airflow from the first direction D1 to the second direction D2. However, in alternative embodiments, the cells of the airflow guiding structure may have different shapes. For example, Fig.16A longitudinal perspective cross-section of an alternative cellular airflow guide structure 24a is shown, in this case having rectangular cells in one linear dimension (the depth of the cells gradually increases with distance along the structure in the same manner as the hexagonal cells described above). As another example, Fig.17 A longitudinal perspective cross-section of another alternative cellular airflow guide structure 24b is shown, in this case having rectangular cells in two linear dimensions (the depth of the cells also increasing with distance along the structure).

[0188] In the above-described embodiment, the airflow is heated, for example, by a heating element in the device body 12 downstream of the fan 38. However, in alternative embodiments, the means for heating the airflow may include the airflow directing structure 24 itself, the airflow directing structure being formed of a material that generates heat when an electric current is applied thereto. In other alternative embodiments, the device may not heat the air, but instead rely on delivering the air at a sufficiently high flow rate to dry the hair.

[0189] Throughout the description and claims of this specification, the words "include" and "comprising" and variations of the words, such as "including" and "comprising", mean "including but not limited to", and are not intended to (and do not) exclude other components, integers or steps.

[0190] Other alternative features related to the above-described embodiments have been developed to solve specific additional problems or provide specific additional functions. These other alternative features (and the specific problems they solve or the additional functions they provide in the case of use) will now be described in detail.

[0191] First, to achieve fast drying and high quality styling (i.e., high levels of shine, color retention, and style durability), hair tresses passing through the active styling area (i.e., the styler head) should be subjected to uniform drying and heating across the entire width of the tress. To achieve this well, the following five considerations have been found to be important:

[0192] (1) The air flow distribution through the effective styling area (i.e., the styling head) should be as uniform as possible.

[0193] (2) The temperature distribution of the air passing through the molding area should be as uniform as possible.

[0194] (3) Root lift vents should be arranged to optimize their function.

[0195] (4) Air should not be allowed to escape from the end of the styler when the styler is closed around the hair and in use.

[0196] (5) The styler should work equally well in any country. There are often small differences in the mains voltage between countries which may result in variations in the motor speed and the power available to the air heater, and therefore the energy delivered to the hair may be different. This should be addressed so that the energy delivery is the same in any country, regardless of the mains voltage, thereby ensuring consistent and uniform performance worldwide.

[0197] Of course, product safety and quality are also extremely important, so the following issues are also considered and addressed:

[0198] (6) When the styler is operated, hot air should not be allowed to flow to the user's hands.

[0199] (7) Residual heat accumulation in air heating components (and related electronic devices) should be avoided to prevent unexpected shutdown or failure of heat-sensitive components such as thermal fuses, especially when the equipment is switched from on to off.

[0200] Points (1) to (7) above are addressed by the following additional features, which are as follows:

[0201] Additional Features 1 - Provides more even airflow distribution across the entire active styling area (i.e. the styler head)

[0202] In the above-described embodiment, the design of the cellular airflow guide structure 24 attempts to provide uniform airflow by using a honeycomb (or other cellular) structure in which the depth of the cells gradually increases toward the distal end of the device to effectively "scoop up" more air as it travels down the length of the head in a direction perpendicular to the cell depth direction. While this technique is helpful, it has been found that with the above-described cellular airflow guide structure 24, a disproportionate amount of airflow is still ejected near the distal end of the device.

[0203] To illustrate this point, Fig.21 The above-mentioned cellular airflow guide structure 24 is shown in the lower arm 14 of the device, wherein the diameters of the hexagonal cells are equal. Fig.21 Consistent, Fig. 22 The airflow distribution along the length of the airflow guide structure 24 is shown, that is, the average jet air velocity at each longitudinal position along the airflow guide structure 24 (along the device head from the terminal end to the handle end). Fig. 22 It can indeed be seen in the figure that a disproportionate amount of airflow leaves the airflow guide structure 24 near the distal end of the device due to the accumulation of airflow towards the end of the device. This is not conducive to uniform styling and can lead to reduced glossiness of the hair, and individual strands of hair being blown in undesirable directions (so-called "flyaway" strands) due to the faster jet air velocity at this location, especially near the end of the device.

[0204] To solve this problem, now see Fig.23 In the alternative (improved) airflow guiding structure 24, the diameter of the honeycomb cells gradually decreases toward the distal end of the device to restrict the airflow. As mentioned above, the depth of the cells also gradually increases toward the distal end of the device. Fig.24 The airflow distribution obtained along the length of the airflow guide structure 24 is shown, and it can be seen from the figure that a more uniform airflow distribution is achieved, wherein the airflow peak is located near the midpoint of the airflow guide structure 24 (i.e., between the terminal end of the device head and the handle end). This airflow distribution achieves more uniform styling, brighter hair sheen, and reduces single strands of hair being blown in undesirable directions.

[0205] Fig.25 Exemplary dimensions of the hexagonal cells of this alternative airflow directing structure 24 are provided. As can be seen, the cell diameter near the styler handle is 4.2 mm, the cell diameter near the midpoint of the airflow directing structure 24 is 3.9 mm, and the cell diameter near the distal end of the device is 3.3 mm. These dimensions are provided as examples only, and may be different in other embodiments (while the cell diameter still tapers toward the distal end of the device). For the sake of completeness, it should be noted that the gradual reduction in cell diameter need not be continuous along the length of the airflow directing structure 24, but may be reduced in stages, i.e., in discrete stages.

[0206] Additional Feature 2 - Providing a more uniform temperature distribution of the air passing through the styling area (i.e., the styler head)

[0207] The temperature of the air passing through the styler head should be as uniform as possible to ensure uniform drying of the entire lock, better alignment of the hair fibers and improved shine and style durability. It has been found that the above-described structure (see, for example, FIG. 1 ) for allowing air to enter the first airflow duct 15 (arranged in and along the first arm 14) from the member 30 and enter the second airflow duct 17 (arranged in and along the second arm 16) is effective. Figure 7 ) cannot provide the desired uniform temperature distribution. The reason lies in the way the airflow into the ducts 15, 17 is generated, and the design of the heater, in particular the annular configuration of the heating element causes the central core of the airflow to be cooler.

[0208] As a result of this problem, a temperature difference of more than 30°C in the jet air can be observed from one end to the other of the airflow guide structure 24. For example, in representative experimental tests, a jet air temperature of 51°C was measured near the proximal end of the airflow guide structure 24 (i.e., near the handle), a temperature of 71°C was measured near the midpoint of the airflow guide structure 24, and a temperature of 86°C was measured near the distal end of the airflow guide structure 24 (i.e., the end of the device).

[0209] Fig.26 , where heated air is ejected near the distal end of the airflow directing structure 24, and cool air is ejected at the proximal end of the airflow directing structure 24. This is because the annular configuration of the heating element 40 (within the heater assembly 44) results in regions of heated air being generated near the heating element 40, and a central core of cooler air being generated between the heated regions.

[0210] Incidentally, it should be noted that Fig.26 (and the subsequent Fig. 27 , Fig.30 and Fig.35 ) shows a variation of the first arm 14, in which all incoming airflow is directed along the first airflow duct 15 and thereby through the airflow guiding structure 24. That is, in this example, the second arm 16 does not include a second airflow duct for delivering air to the styler head (but may still include an airflow guiding structure in communication with the inter-arm chamber 13 for receiving air ejected from the first arm 14). Conversely, in another variation, all incoming airflow may be directed along the second airflow duct 17 within the second arm 16 and not along the first arm 14. This variation may make the manufacture of the entire apparatus easier, and may also improve airflow performance, because the opposing airflows from the first duct 15 and the second duct 17 are prevented from colliding with each other and causing turbulence within the inter-arm chamber 13, and also provide a well-defined "escape route" for the moisture-laden air.

[0211] See also Fig. 27 The above-mentioned problem of uneven temperature distribution can be solved by providing an air flow mixer 42 near the end of the heater assembly 44 before the air flow duct 15. In this case, the air flow mixer is in the form of an air flow diverter or splitter. The air flow mixer 42 mixes the heated air (from the vicinity of the heating element) with the central core of cooler air, thereby providing a more uniform heated air flow along the air flow guiding structure 24. The air flow mixer 42 can be generally conical or conical as shown in the figure, or other shapes to produce turbulence and mixing of air in the air flow.

[0212] Since the airflow mixer 42 removes or reduces the cold air core, the temperature difference of the jet air from one end to the other end of the airflow guide structure 24 can be significantly reduced. For example, in a control experimental test in which the airflow mixer 42 is present, a jet air temperature of 68°C was measured near the proximal end of the airflow guide structure 24 (i.e., near the handle), a temperature of 82°C was measured near the midpoint of the airflow guide structure 24, and a temperature of 80°C was measured near the distal end of the airflow guide structure 24 (i.e., the end of the device). Therefore, in this case, the temperature difference from one end to the other end of the airflow guide structure 24 is only 12°C.

[0213] Fig.28 yes Fig. 27 A perspective view of the heater assembly 44 is shown in FIG. 4, showing the air flow mixer 42 located in the center. Similarly, Fig.29 yes Fig.28 A lateral plan view of the heater assembly 44 is shown, and a diagram of the heating coil 40 is also shown.

[0214] Additional Feature 3 - Improved Root Lift Vent Functionality

[0215] In the above embodiment, if Fig.10 As shown, for example, root lift vents 26 are provided along either side of the head of the styler head and extend parallel to the plane of the heating plates 20a, 20b, 22a, 22b.

[0216] However, now refer to Fig.30 Further development work has found that improved root lift of the hair can be achieved if the air leaves the vents 26 at about 45° to the plane of the heating plates 20a, 20b, 22a, 22b in directions D3' and D4', rather than parallel to the plane of the heating plates. This means that on either side of the styler head, the airflow direction D4' is not opposite to D3' (as opposed to Fig.10 ). Instead, the airflow directions D3' and D4' are about 90° to each other on either side of the styler head. Other angles between the airflow directions D3' and D4' ejected from the root lift vents are also possible.

[0217] It has been found that orienting the root lift vents 26 at an angle that is not parallel to the plane of the heating plates 20a, 20b, 22a, 22b is advantageous because when the root lift airflow is parallel to the heating plates, it has been found that "fly-away" hair strands are produced and the alignment of the hair fibers is reduced, thereby reducing the end result of shine and style durability. Therefore, it has been found that an angle of about 45° reduces the production of "fly-away" hair strands while still providing a flow angle that makes it easy for the user to produce a root lift. If the angle is much greater than 45°, it becomes more difficult to produce a root lift.

[0218] from Fig.30 It should also be noted that in this variation of the styler head, the incoming airflow flows only along the first airflow conduit 15, then (in direction D2) through the airflow directing structure 24 and into the inter-arm chamber 13. Thus, in this variation, the second arm 16 does not include a second airflow conduit for delivering air to the styler head, but still includes an airflow redirecting channel 28 for receiving some of the air ejected from the first arm 14 and delivered through the inter-arm chamber 13 via the airflow directing structure 24.

[0219] The air then diffuses laterally from the inter-arm chamber 13 (e.g., by means of an angled surface 46 incorporated into the second arm 16) and enters the airflow redirection channel 28, whereupon the air passes along the airflow ducts 19a, 19b, 21a and 21b, exiting the device through the vent 26 in the 45° directions D3' (via ducts 19a and 21a) and D4' (via ducts 19b and 21b). Fig.30 As shown, the airflow ducts 19a, 19b, 21a and 21b extend behind the heating plates 20a, 20b, 22a and 22b mounted on the first arm 14 and the second arm 16, respectively.

[0220] Additional Feature 4 - Reduced air escape from the distal end of the styler

[0221] In the above embodiment, it has been found that when the styler is closed with hair between the heating plates, air may escape from the distal end of the styler, particularly at the end of the heating plates. It has been found that this reduces the drying rate because less air passes through the hair strands and can also cause fiber alignment problems.

[0222] However, now see Fig.31 and 32 After further development work, the problem of air escaping from the distal end of the styler has been solved by providing mutually opposing spring-loaded heat-non-conductive (e.g. plastic) sealing elements 48 on the top and bottom styler arms 14, 16 at the distal end of the device. The sealing elements 48 are flat and also rise above the adjacent heating plates (e.g. 20a, 20b) to ensure that when the heating plates are loaded with hair, the top and bottom sealing elements 48 come together to form a seal, thereby preventing air from escaping from the end of the styler along the heating plates. Each sealing element 48, through its mounted spring, allows different amounts of hair to be placed between the heating plates and still allow a seal to be maintained.

[0223] Additional Feature 5 - Achieving Consistent Performance Worldwide

[0224] It is desirable that a styler product should have substantially the same performance wherever it is used in the world, even though the mains voltage may vary from country to country. Mains voltage variations can affect, among other things, the temperature of the heated air within the device, since the air is heated using a standard resistance wire heater, and the electrical power consumed by such a heater and converted into heat is a function of voltage. It is therefore desirable to ensure that the energy delivered to the air is the same, wherever the device is in the world, thereby ensuring that the drying rate is the same and that the product does not damage the hair fibers.

[0225] Control of the energy delivered to the air can be achieved in a variety of ways - for example by varying the fan speed (which is undesirable because it affects the amount of airflow), or by using a variable resistor in the heater (which is also undesirable). Another option that has been found to work well is to control the temperature of the heater by electrical switching techniques, while keeping the fan speed constant. For example, standard zero-crossing switching techniques using triacs can be used to control the number of mains cycles per second across the heater, essentially performing pulse width modulation of the electrical power supplied to the heater. In this way, the thermal output of the heater element (and more generally, the thermal output of the device) can be controlled regardless of changes in the local mains voltage.

[0226] Other feature 6 - Prevents hot air from flowing to the user's hands when operating the styler

[0227] For safety and comfort, given that the temperature of the air can exceed 100°C, the air should not flow back into the user's hands. During internal testing with early prototypes of the styler, it was found that while styling, hot air could escape from the end of the heating plate closest to the handle / hinge and risk causing discomfort to the user.

[0228] To solve this problem, see Fig.33 and Fig.34 , a ramp-like airflow deflector feature 50 has been developed (also in Fig.32 ), for inclusion at the proximal end (i.e., handle end) of each of the pair of heating plates (i.e., plates 20a and 20b, or plates 22a and 22b) to prevent hot air from escaping backwards toward the user's hands. The ramp-like shape of the deflector 50 is important for two reasons: to prevent air from passing backwards, and to not catch the user's hair during styling. In contrast, a standard "block" form would risk creating a pinch point that pulls and catches the user's hair. The ramp design of the deflector 50 prevents this from happening, and also redirects the return air (which would otherwise escape toward the user) toward the opposite arm of the device to prevent discomfort to the user's hands.

[0229] Additional Feature 7 - Avoidance of excess heat build-up in air heating components (and associated electronics), particularly when equipment is switched from on to off

[0230] For safety reasons, styler appliances typically contain a thermostat and a thermal fuse, either of which will cause the appliance to cease operation if tripped (or, in the case of a thermal fuse, if blown). The thermostat is resettable and is designed to prevent accidental blockage of the air inlet to the appliance or inadequate filter cleaning. If the thermostat is tripped, the appliance can be used again once it has cooled down.

[0231] However, a thermal fuse blowing is a more permanent problem (requiring replacement of the thermal fuse), and thermal fuses are designed to prevent uncontrolled catastrophic failure of equipment, such as a commutation failure in a triac driving an air heater. A thermal fuse failure can render the product unusable until the thermal fuse is replaced. Therefore, it is undesirable for a thermal fuse to fail during normal and safe use.

[0232] In internal testing with early prototypes of the styler, it was found that when the unit is switched from on to off (i.e., at the end of a usage period) and the internal fan is therefore stopped, the temperature spikes of the air heating components in the area of ​​the thermostat and thermal fuse can reach high temperatures. After multiple operating cycles and extended periods of time, such temperature spikes can cause the thermostat to trip or the thermal fuse to blow, especially in extreme cases of filter plugging. (Also, the activation temperatures of both components are very different from the nominal activation temperatures and degrade with age.) Such tripping of the thermostat or blowing of the thermal fuse can cause an undesirable failure of an otherwise properly functioning safety device.

[0233] One way to address this problem is to have the internal fan continue to operate in a so-called "ramp-down" mode when the device switches from on to off. Thus, the fan continues to run for a shorter period of time to reduce excess heat in the heated components and associated electronics. That is, the fan in ramp-down mode removes excess heat from the system by passing air over the components.

[0234] However, it has been found that if someone unplugs the device rather than simply turning the product off using its on / off switch, the temperature will peak as previously described because the fan cannot enter ramp-down mode.

[0235] See also Fig.35This problem has been addressed by providing an initial airflow separator 52 at the inlet of the heater assembly 44. The airflow separator 52 has a generally tapered or conical shape to direct the incoming airflow from the fan toward the heating coil 40 (rather than simply passing it along the center of the heater assembly 44). By directing the incoming airflow specifically to the heating coil 40 in this manner, a more efficient heat transfer from the coil 40 to the incoming airflow is provided during use. In addition, because the coil 40 operates more efficiently, more heat is transferred from the coil to the incoming airflow, so less heat accumulates in the coil (and associated electronics) itself, making it generally cooler. Therefore, when the device is switched from on to off, there is less residual heat present in the heating system. Therefore, even if the fan is suddenly turned off, the temperature spikes to which components such as thermostats and thermal fuses are exposed are less severe and therefore will not trip or blow.

[0236] To further illustrate this point, Fig.36 A graph showing the internal air temperature versus time in the area of ​​the thermostat (lower line) and thermal fuse (upper line) in a styler apparatus having an airflow splitter 52 is shown. The graph spans the point at which the apparatus switches from on to off and the internal fan stops. It can be seen that at the moment the apparatus is off and the fan stops, a moderate thermal spike of approximately 80°C is experienced near the thermostat and thermal fuse, reaching a maximum temperature of approximately 140°C. This thermal spike is within the allowable operating temperature of these components and does not cause the components to trip or blow.

[0237] As a control, Fig.37 The corresponding graphs of internal air temperature versus time are shown in the region of the thermostat (lower line) and thermal fuse (upper line) in a test styler device without an airflow separator 52. Again, the graph spans the point at which the device switches from on to off and the internal fan stops. It can be seen that a more significant thermal spike of approximately 100° C. is experienced near the thermostat and thermal fuse at the moment the device is off and the fan stops. A maximum temperature of approximately 160° C. is reached near the thermal fuse, which in some cases is sufficient to cause the component to fuse. Therefore, this problem is prevented by providing an airflow separator 52.

[0238] Fig.35 It also shows that according to Figure 27 to Figure 29 The airflow mixer 42 of the present invention is provided, although the airflow mixer 42 and the airflow separator 52 do not necessarily exist at the same time. However, if both the airflow mixer 42 and the airflow separator 52 exist, a synergistic advantage can be achieved, namely, more effectively heating the incoming air and more evenly delivering the heated air to the user's hair.

[0239] In fact, by implementing all of the above-mentioned "other features" 1 to 7 in a single device, a well-functioning styler device with many synergistic advantages can be obtained. However, if necessary, any of the "other features" 1 to 7 can be omitted. In fact, in the broadest sense, none of the "other features" 1 to 7 should be considered essential to the present disclosure, and the scope of the present disclosure is defined by the appended claims.

Claims

1. A device for drying and styling hair, comprising: a first arm and a second arm opposed to each other, the first arm and the second arm being adapted to move between an open configuration for receiving a section of wet hair therebetween and a closed configuration adjacent to the hair so that, in use, an arm chamber is formed for the hair to pass through when the arms are in the closed configuration, and wherein an airflow duct is provided within and along at least one of the first arm and the second arm; and Means for conveying a gas flow, which conveys the gas flow along a duct in at least one of the first arm and the second arm, and then conveys the gas flow into the inter-arm chamber.

2. The device according to claim 1, wherein: One or both of the arms further comprises an airflow guiding structure, which is arranged to receive the airflow from the corresponding duct and guide the airflow from a first direction to a second direction, thereby guiding the airflow into the inter-arm chamber, wherein the first direction is substantially parallel to the length of the corresponding arm, and the second direction is a direction from the corresponding arm toward the opposite arm.

3. The device according to claim 2, wherein: Each of the first arm and the second arm comprises a corresponding duct and a corresponding airflow guiding structure, and the device for conveying airflow is arranged to convey air along the duct in each of the first arm and the second arm, and then convey the air through the corresponding airflow guiding structure and into the inter-arm chamber.

4. The device according to claim 3, wherein: Each airflow directing structure is offset from an imaginary centerline located midway between the first arm and the second arm when the first arm and the second arm are in the closed configuration.

5. The device according to any one of claims 2 to 4, wherein: The ducts in the or each arm act as plenums through which the air flows into the respective airflow directing structure and thence into the inter-arm chamber.

6. The device according to claim 5, wherein: The airflow directing structure in the or each arm comprises a cellular structure configured to direct the airflow from the first direction to the second direction, the cellular structure comprising a plurality of cell walls extending into the respective plenum chambers along the second direction.

7. The device according to claim 6, wherein: The depth of the cells into the corresponding plenum chamber gradually increases with increasing distance along the corresponding arm.

8. The device according to claim 6 or 7, wherein: The diameter of the unit cell gradually decreases with increasing distance along the corresponding arm.

9. The device according to any one of claims 6 to 8, wherein: The cellular structure has a honeycomb structure.

10. The device according to any one of claims 6 to 9, wherein: The airflow guiding structure or each airflow guiding structure also includes a plurality of airflow redirection channels, which are configured to convey the airflow from the second direction to a third direction and a fourth direction, wherein the third direction and the fourth direction are directions outward from the device and substantially perpendicular to the length of the arm.

11. The device according to claim 10, wherein: The airflow redirection channels extend between longitudinal edges and corresponding longitudinal sides of the airflow guide structure.

12. The device according to any of the preceding claims, further comprising mutually opposing plates arranged on the first arm and the second arm, the mutually opposing plates being arranged to be brought together when the first arm and the second arm are in the closed configuration.

13. The device according to claim 12, wherein: First and second plates are disposed on the first arm, and corresponding opposing first and second plates are disposed on the second arm.

14. The device according to claim 12 or 13, wherein: At least one of the plates comprises means for applying heat to the section of hair when the first arm and the second arm are in the closed configuration, in use.

15. The device according to claim 13 or 14 when referring to claim 10 or 11, further comprising an airflow duct extending behind the first plate and the second plate of the corresponding arm, and the airflow duct is arranged to receive air from the airflow redirection channel, and guide the airflow behind the first plate and guide the airflow to flow out substantially along the third direction through the vents along the edge of the device, and guide the airflow behind the second plate and guide the airflow to flow out substantially along the fourth direction through the vents along the edge of the device.

16. The device according to claim 15, wherein: The cellular structure, the airflow guiding structure of the airflow redirecting channel, and the outward vents along the third direction and the fourth direction are an integrated structure.

17. The device according to claim 15 or 16, wherein: The outward vents are oriented at an angle of approximately 45° relative to the plane of the plate.

18. The apparatus of any one of claims 3 to 17, further comprising an airflow separator arranged to separate the airflow into the ducts within the first arm and the second arm along the first direction.

19. The device according to claim 18, wherein: The air flow separator includes a flexible member.

20. An apparatus according to any preceding claim, wherein: The means for delivering air flow comprises a fan.

Images