CN114173605A - Hair drying and styling apparatus and method - Google Patents

Abstract

A device for drying and styling hair comprising: first and second mutually opposed arms adapted to be moved between an open configuration for receiving a length of wet hair between the two arms and a closed configuration adjacent the hair so that, in use, an inter-arm chamber is formed through which the hair passes when the arms are in the closed configuration, and wherein an air flow conduit is provided in and along at least one of the first and second arms; and means for conveying the airflow along a duct within at least one of the first and second arms and subsequently into the inter-arm chamber. A method of drying (and optionally simultaneously styling) hair using such a device is also provided.

Description

Hair drying and styling apparatus and method

Technical Field

The present disclosure relates to a device for drying and styling human (or conceivable animal) hair, for example after washing the hair or as part of a styling (styling) process. That is, prior to use of the present disclosure, the hair is wet (or "towel dried"), and then can be dried and styled using the present disclosure. Such drying and styling of hair may be performed, for example, by the user for his own hair, or by a stylist. It should also be noted that the term "wet" as used herein should be interpreted broadly to include not only hair wetted with water, but also hair wetted with liquids other than water. For example, hair may be wetted with solvent-based colorants that may be dried using the present disclosure.

Background

It is known that conventional hand held hair dryers incorporate a powered fan for blowing a stream of cold or hot air to dry a person's hair. The fan draws ambient air into the body of the dryer and blows a stream of air towards the hair to be dried. When blowing hot air, an electrical heating element, typically incorporated within the blower body, is used to heat the air stream before it leaves the blower. Alternatively, the blower may be equipped with a concentrator nozzle attachment for enhancing and directing the air flow, or a diffuser attachment for more gently delivering the air.

However, conventional blowers can often be relatively noisy, heavy and bulky. Furthermore, conventional hair dryers may be difficult to use and may be difficult for a user (particularly a domestic user who treats his own hair) to achieve the desired result, particularly in styling hair while drying the hair. For example, hair dryers are often used in conjunction 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 "body and volume" to hair (if desired, applying a styling product such as mousse, gel, wax, hair spray, etc. before or after styling). The simultaneous manipulation of the hair dryer and brush (or comb, etc.) around the head can be inconvenient for the user and often requires a degree of skill to achieve the desired result.

Thus, while the use of a conventional hair dryer is the fastest method of drying hair, it can be very difficult and/or time consuming to form the desired end result in styling therewith. For this purpose, the user has to use a brush and/or an additional hair styling tool.

As an alternative to conventional hair dryers, some people may use products such as hot air brushes or hot air paddle brushes in hair styling. However, this product, while easy to use, dries the hair very slowly.

Another type of quick and easy to use product is the so-called "wet straight" hair straightener. This product dries and straightens hair by drawing wet hair between a pair of heated plates mounted on opposite arms of the device. These devices tend to use conductive heating (typically 185 ℃ to 230 ℃) for wet hair at high temperatures, but may damage the hair, and/or are perceived to damage the hair because of the sound of cavitation (cavitation) or the use of elevated temperatures near the denaturation temperature of wet hair.

Disclosure of Invention

The present disclosure is directed to alternative apparatus and methods for conventional hand held hair dryers to dry hair by combining the functions and advantages of conventional hair dryers with the functions and advantages of hair straighteners in a single, grippable size device. Advantageously, therefore, embodiments of the present disclosure provide a device for drying and styling hair as a single hand-held device that is simple to use and more flexible than simultaneously manipulating a conventional hair dryer and brush, comb, or other styling device around the head.

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

first and second mutually opposed arms adapted to be moved between an open configuration for receiving a length of wet hair therebetween and a closed configuration adjacent the hair so that, in use, an inter-arm chamber is formed through which the hair passes when the first and second arms are in the closed configuration, and wherein an air flow conduit is provided in and along at least one of the first and second arms; and

means for conveying the airflow along a duct within at least one of the first and second arms and subsequently into the inter-arm chamber.

The term "chamber" as used herein should be broadly construed to include chambers that are at least partially open on one side as well as closed chambers.

By the construction of the device, including the at least one air flow duct and the arm compartment formed by the arms in the closed configuration, the air transport to the hair is enhanced, so that the hair can be dried/styled quickly and easily, and also the energy efficiency can be improved.

Preferably, one or both of the first and second arms further comprises an airflow directing structure arranged to receive an airflow from the respective duct and direct the airflow from a first direction to a second direction, the first direction being substantially parallel to the length of the respective arm, and the second direction being from the respective arm towards the opposite arm, so as to direct the airflow into the inter-arm chamber. This arrangement of the air flow guiding structure further enhances the air transport to the hair, further facilitates the drying/styling process, and enables a further improvement of the energy efficiency.

In a particular embodiment, each of the first and second arms comprises a respective duct and a respective air flow directing structure, and the means for conveying an air flow is arranged to convey air along the duct within each of the first and second arms, and subsequently through the respective air flow directing 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.

Each airflow directing structure may be offset from an imaginary centerline located intermediate the first and second arms when the first and second arms are in the closed configuration. Such deviation advantageously creates an airflow restriction between the air and the hair when in use, to increase the airflow velocity around the hair, thereby accelerating drying. In a particular embodiment, each air flow directing structure is offset by about 2mm relative to the imaginary centre line (i.e. the air flow directing structures are separated from each other by a distance of about 4 mm).

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

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.

The depth of the cells into the respective inflatable chambers may gradually increase with increasing distance along the respective arms. This configuration advantageously diverts incoming airflow in a first direction and exits from the plenum chamber in a second direction and enters the inter-arm chamber at a uniform airspeed.

Alternatively or additionally, the diameter of the cells of the airflow directing structure in the or each arm may progressively decrease with increasing distance along the respective arm. It has been found that this configuration provides a more even distribution of the airflow along the airflow directing structure.

In a presently preferred embodiment, the cellular structure has a hexagonal (honeycomb) structure. The inventors have found that this is advantageous to maximise the open area through the guide structure whilst minimising the area occupied by the cell walls and thereby minimising the airflow resistance caused by the cell walls.

The or each airflow directing structure may further comprise a plurality of airflow redirecting channels configured to convey airflow from the second direction to third and fourth directions, the third and fourth directions being directions outwardly from the device substantially perpendicular to the length of the arm. By discharging air in these third and fourth directions, the air can be easily directed towards the root of the hair, drying the root and enabling root lift to be produced.

In a presently preferred embodiment, the air flow redirecting channel extends between a longitudinal edge and a respective longitudinal side of the air flow directing structure.

The apparatus may further comprise mutually opposing plates arranged on the first and second arms, the mutually opposing plates being arranged to come together when the first and second arms are in the closed configuration. More particularly, the first and second plates may be disposed on the first arm, and the respective opposing first and second plates may be disposed on the second arm. At least one of the plates may comprise means for applying heat to a length of hair when the first and second arms are in the closed configuration, in use, to assist in the drying/styling process.

Airflow ducts extending behind the first and second panels of the respective arms may be provided to receive air from the airflow redirection channels and direct airflow behind the first panel and substantially in a third direction through the vents along the edge of the device and to direct airflow behind the second panel and substantially in a fourth direction through the vents along the edge of the device.

In certain embodiments, the airflow directing structure comprising the cellular structure and the airflow redirection channels and the outward vents in the third and fourth directions may be formed as a unitary structure (e.g., by 3D printing).

Advantageously, the outward vents may be oriented at an angle of about 45 ° relative to the plane of the plate to enhance the degree of root lift produced.

The apparatus may further comprise a flow separator arranged to divide the flow in the first direction into the ducts within the first and second arms. Optionally, the airflow separator may comprise a flexible member.

The means for conveying the air flow may comprise a fan. The fan may advantageously comprise a brushless motor designed to operate at high speed (e.g. over 30000 revolutions per minute) and low power (e.g. maximum 15W, 3W during normal operation) and may be driven by a dc power supply. It has been found that this high speed low power parameter of the fan provides excellent drying performance, drying hair as fast as a 2000W conventional hair dryer, but with significantly reduced power usage.

The presently preferred embodiment also comprises means for heating the gas flow, such as one or more heating elements or electric heating coils, for example.

Advantageously, the apparatus may further comprise a gas flow separator arranged to direct the incoming gas flow towards the heating coil, thereby improving the efficiency of heat transfer from the coil to the incoming gas flow during use. For example, the gas flow separator may have a conical or conical shape.

Furthermore, the device may further comprise means for performing pulse width modulation of the electrical power applied to said means for heating said gas flow. This may advantageously be used to regulate the heat output of the heating device regardless of changes in the supply voltage (e.g. due to local variations in the mains voltage worldwide).

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

Optionally, the device may further comprise one or more sets of flexible bristles on the first and/or second arms, outside or inside the inter-arm chamber, the flexible bristles being arranged to facilitate the application of uniform tension to hairs passing through the inter-arm chamber in use.

Advantageously, to prevent air from escaping through the end of each of the first and second arms, the device may further comprise mutually opposing spring-loaded sealing elements at the distal ends of the arms.

In addition, the device may further comprise at least one airflow deflector located on an 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 hand. Such an airflow deflector may advantageously be ramp-shaped.

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

The method may further comprise using the apparatus described above to style the hair substantially simultaneously with drying the hair.

Drawings

Embodiments of the present disclosure will now be described, by way of example only, with reference to the accompanying drawings. In the drawings:

figure 1 is a perspective view of a combined blower/styler apparatus comprising means for blowing and heating air, an air flow separator and mutually opposed drying/styling arms in an open configuration, wherein each arm comprises an air flow directing structure and a pair of heating plates, respectively;

FIG. 2 shows the apparatus of FIG. 1 with the arms in a closed configuration;

FIG. 3 shows the apparatus of FIG. 1 in use;

FIG. 4 is a longitudinal perspective cross-sectional view of the device of FIG. 1 showing some exemplary internal components;

FIG. 5 is a longitudinal plan sectional view of the apparatus of FIG. 1;

FIG. 6 is a close-up perspective view of the arms of the device of FIG. 1 in an open configuration;

FIG. 7 is a side cross-sectional view of the arms of the apparatus of FIG. 1 in an open configuration through an airflow directing structure, the airflow directing structure of each arm being shown as having a cellular structure in which the depth of the cells progressively increases with increasing distance along the respective arm;

FIG. 8 is a side cross-sectional view as in FIG. 7, but with the arms in a closed configuration and also showing the direction of airflow along and between the arms;

FIG. 9 is a perspective view of an arm of the apparatus of FIG. 1, the arm being closed around the illustrated bundles of wet hair;

FIG. 10 is a transverse cross-sectional view through the arm of the apparatus of FIG. 1 in a closed configuration, and also showing the direction of airflow;

fig. 11 is a transverse cross-sectional view through the arm of the device in a closed configuration (around a hair) corresponding to fig. 10, and showing more detail;

FIG. 12 is a longitudinal perspective cross-sectional view along the arms of the device of FIG. 1 in a closed configuration around the hair, showing the change in direction of airflow due to the airflow directing structures in each arm;

FIG. 13 is a transverse perspective cross-sectional view through the arm of the device of FIG. 1 in a closed configuration around a hair, again showing the change in direction of the airflow;

FIG. 14 is a perspective view of the arm member of the apparatus of FIG. 1 without the plate, again showing the change in direction of the airflow;

FIG. 15 is a perspective view in longitudinal section of the arm member of FIG. 14, again showing the airflow directing structure having a cellular structure (with hexagonal cells) wherein the depth of the cells progressively increases with increasing distance along the respective structure;

FIG. 16 is a longitudinal perspective sectional view of an alternative embodiment of a cellular airflow directing structure, in this case having rectangular cells in one linear dimension (the depth of the cells also gradually increasing with increasing distance along the respective structure);

FIG. 17 is a longitudinal perspective sectional view of another alternative embodiment of a cellular airflow directing structure, in this case having rectangular cells in two linear dimensions (the depth of the cells also gradually increasing with increasing distance along the respective structure);

FIG. 18 is a close-up, longitudinal perspective cross-sectional view of the airflow separator of the apparatus of FIGS. 1-15, and further illustrating a plurality of baffles and diffuser grills;

FIG. 19 is another view of a portion of the apparatus of FIG. 1, particularly illustrating a plurality of baffles between the fan and the arms;

FIG. 20 is a graph of hair sample temperature versus drying time to aid in understanding background principles;

FIG. 21 is a plan view of an example of an arm member in which the unit cell diameters of the airflow directing structures are equal;

FIG. 22 shows the airflow distribution along the length of the airflow directing structure of FIG. 21;

FIG. 23 is a plan view of another example of an arm member in which the diameter of the cells of the airflow directing structure decrease along the structure;

FIG. 24 illustrates the airflow distribution along the length of the airflow directing structure of FIG. 23;

FIG. 25 provides, by way of example only, exemplary dimensions of the hexagonal cells of the airflow directing structure of FIG. 23;

FIG. 26 is a side cross-sectional view of an example of an arm member in which heated air and cold air are not mixed before reaching an airflow directing structure;

FIG. 27 is a side cross-sectional view of another example of an arm member in which heated air and cooled air pass through an airflow mixer before reaching an airflow directing structure;

FIG. 28 is a perspective view of a heater assembly having a gas flow mixer (in the form of a gas flow separator) in the center;

FIG. 29 is a transverse plan view of the heater assembly of FIG. 28;

FIG. 30 is a transverse cross-sectional view through a modified arm of the apparatus of FIG. 1 in a closed configuration and showing the direction of airflow (airflow originating from only one arm);

FIG. 31 is a perspective view of a sealing element at one end of an arm of a variation of the apparatus of the present disclosure;

figure 32 is a side cross-sectional view of two opposing arms of a combination blower/styler device in a closed configuration, wherein each arm has a sealing element as shown in figure 31, the sealing elements meeting to prevent air from escaping from the ends of the device;

figure 33 is a side cross-sectional view of two opposing arms of a combination blower/styler apparatus with a ramp feature behind a heater plate on one arm (in this case the upper arm) to deflect air flow away from a user's hand;

FIG. 34 is a close-up perspective view of the ramp feature of FIG. 33;

figure 35 is a side cross-sectional view of an air heater of a combination blower/styler apparatus showing (filled with solid black on the left side of the figure) an air flow mixer (air flow separator) as shown in figures 27 and 28 to mix the air before it reaches the air flow directing structure; and showing (filled with solid black on the right side of the figure) an initial gas flow separator to direct the incoming gas flow towards the heating coils of the apparatus;

FIG. 36 shows a graph of the inside air temperature over time in the thermostat (lower line) and thermal fuse (upper line) regions of the appliance associated with the appliance of FIG. 35, spanning the point at which the appliance switches from on to off and the inside fan stops; and is

Fig. 37 shows by comparison a graph corresponding to fig. 36 in the absence of the initial gas flow separator of fig. 35.

In the drawings, like elements are denoted by like reference numerals throughout.

Detailed Description

The embodiments of the disclosure represent the best modes known to the applicant for carrying out the disclosure. However, these ways are not the only way to implement the present disclosure.

Overview of Combined Hair dryer/styler device

Figure 1 is a perspective view of a combined blower/styler device 10 according to a first embodiment, in which the arms 14, 16 are in an open configuration, and figure 2 shows the same device with the arms 14, 16 closed (in use, as shown, for example, in figure 3). Fig. 4 to 15 show further views of parts of the apparatus 10, and fig. 8 to 14 show parts of the apparatus in use.

Referring first to fig. 1 and 2, the device 10 is a one-piece, handheld device that can be used to quickly and easily dry hair while also being able to style (style) the hair (e.g., straighten the hair, or increase the "volume feel" of the hair).

The device 10 includes a body portion 12, and first and second mutually opposed arms 14, 16, the first and second arms 14, 16 being arranged in a substantially similar manner to the arms of a hand-held hair styler. The first and second arms 14, 16 are adapted to move between an open configuration (as shown in figure 1) for receiving a length of wet hair between the two arms, and a closed configuration (as shown in figure 2) adjacent the hair to create tension in the hair, such that, in use, when the arms 14, 16 are in the closed configuration, the arms 14, 16 form an inter-arm plenum (13, figure 10) through which the hair passes.

Turning briefly to fig. 7, a first gas flow conduit 15 is disposed within and along the first arm 14, and a second gas flow conduit 17 is disposed within and along the second arm 16. In alternative embodiments (e.g., as shown in fig. 27, 30, and 35), only one arm may contain such an airflow conduit.

Referring to fig. 4 and 5, the apparatus further comprises a fan assembly 38 within the main body portion 12 for conveying an 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 typically also provided with a filter.

For example, as shown in fig. 1, 4, 5, 7, 8, each of the first and second arms 14, 16 further comprises a respective air flow directing structure 24, the air flow directing structure 24 being arranged to receive an air flow from the respective first or second duct 15, 17 and to direct (i.e. divert) the air flow from a first direction (D1, fig. 8) substantially parallel to the length of the respective arm (i.e. incoming air which is longitudinal along the device) to a second direction (D2, fig. 8) from the respective arm towards the opposite arm (i.e. inwards into the inter-arm plenum 13 formed by the first and second arms 14, 16 in the closed position. In an alternative embodiment, only one of the arms 14, 16 may be provided with such an airflow directing structure 24 if only one arm contains an airflow duct. The construction and function of the airflow directing structure 24 will be described in more detail below. In other variations, the airflow directing structure(s) 24 may be omitted entirely.

For example, as shown in fig. 1, the first arm 14 is a continuation of the body portion 12, and the second arm 16 is coupled to the body portion 12 by a hinge 18, the first arm 14 and the second arm 16 being movable relative to each other by the hinge 18 (in the illustrated embodiment, by moving the second arm 16 toward the first arm 14). Thus, in use, a user may bring the first and second arms 14, 16 together so as to be in a closed configuration (as shown in FIG. 2) or move them apart so as to be in an open configuration (as shown in FIG. 1). In the illustrated embodiment, each of the arms 14, 16 is widened relative to the body portion 12, respectively, to form a "head" of the device 10 remote from the body portion 12, although other embodiments are possible in which the head is not widened in the manner shown.

The hinge 18 may comprise any suitable means to allow the first and second arms 14, 16 to move relative to each other.

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

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 portion 12, thereby obviating the need to provide a separate mechanical hinge and simplifying the overall construction of the device.

As shown in fig. 1 and the close-up of fig. 6, in the illustrated embodiment, the inner surface of first arm 14 comprises a first elongated heated plate 20a and a second elongated heated plate 20b that are parallel to each other and to the length of arm 14. Second arm 16 also includes first and second elongated heated plates 22a and 22b (not visible in fig. 1 and 6, but shown, for example, in fig. 10 and 11) at locations corresponding to heated plates 20a and 20 b. Each heating plate is provided with a respective electrical heating element operable to heat the respective heating plate. In the illustrated embodiment, the operating temperature of the heating plate is typically about 120 ℃ to 130 ℃.

The first and second arms 14, 16 and the first and second heated plates on each arm are arranged such that, when the apparatus 10 is in the closed configuration, the first and second heated plates 20a, 20b of the first arm 14 are in contact with the first and second heated 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).

Alternatively, flexible bristles may be disposed alongside the heated plates 20a, 20b, 20c, 20 d. More particularly, the flexible bristles may be positioned on either or both sides of first arm 14, and/or on either or both sides of second arm 16, adjacent the entrance/exit of hair into/out of heated plates 20a, 20b, 20c, 20 d. Alternatively or additionally, flexible bristles may be provided in or around the airflow directing structure 24, between the heating plates. Such bristles enable a more uniform tension to be applied to hair fibres within a hair section passing through the chamber 13 formed by the arms 14, 16 in the closed position.

As shown in fig. 1, a control button or switch 23 may be provided on the device 10 so as to be capable of being turned on or off along with an indicator light to indicate whether power is on. When the device 10 is switched on and ready for use, sound may also be played by a sound generator (not shown).

As shown in the cross-sectional views of fig. 4 and 5, the fan assembly 38 is mounted towards the end of the body portion 12 remote from the first arm 14. A motor-driven fan 38 operable to draw air from the surrounding environment and to convey an airflow along the interior of the main body 12; and then the air flow enters and is conveyed along ducts 15, 17 in arms 14, 16; and then the air flow 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.

Advantageously, the fan 38 may comprise a brushless motor designed to operate at high speed (e.g., over 30000 revolutions per minute) and low power (e.g., maximum 15W, 3W during normal operation), and may be driven by a dc power source. It has been found that this high speed low power parameter of the fan provides excellent drying performance, drying hair as fast as a 2000W conventional hair dryer, but with significantly reduced power usage.

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

The heating plates 20a, 20b, 22a, 22b serve a variety of purposes during use of the apparatus 10. First, the user clamps a length of wet hair between the opposing plates 20a and 22a and between the opposing plates 20b and 22b (i.e., transversely through the inflatable chamber 13 formed by the first and second arms 14 and 16 in the closed configuration), and by pulling the device along the length 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 the 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 air flow delivered through the plenum 13 by the fan 38. Again, as an integral part of the drying process, the heating plates 20a, 20b, 22a, 22b may be used to style the hair.

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 a good control of the hair tension.

Considering the airflow heating coils (or other heating elements) and the heating plates 20a, 20b, 22a, 22b and the fan 38, the total power consumption of the apparatus 10 is about 600W to 800W, significantly less than 2000W for a conventional hair dryer.

As shown in fig. 4 and 5, the electrical and electronic circuitry of the device 10 is housed within the main body portion 12 and the first and second arms 14, 16 (although primarily within the main body portion 12 and the first arm 14). In the illustrated example, the printed circuit board assembly 36 is disposed within the body portion 12. Power is supplied to the device 10 by a power source located at the end of the main body portion 12 remote from the first arm 14. In the illustrated embodiment, the power source is an ac mains power source. However, in alternative embodiments, the power supply may comprise one or more dc batteries or battery units (which may be rechargeable, e.g. from the mains or from a dc power supply via charging conductors), thereby enabling the device 10 to be a cordless product.

Wherein the circuit board assembly 36 comprises four TRIACs 37, each for powering a respective one of the heater plates 20a, 20b, 22a, 22 b.

Air flow guide

The device 10 incorporates a number of features that direct an airflow from the fan 38 to the user's hair 11, thereby enabling the hair to be dried and styled. These features will now be described in detail with particular reference to fig. 7-15.

As described above, and as shown for example in fig. 7, in the illustrated embodiment each of the first and second arms 14, 16 (at the head of the device 10 remote from the main body portion 12) includes a cellular airflow directing structure 24 in airflow communication with the respective first or second duct 15, 17. The first and second ducts 15, 17 act as plenums to supply air through the guide structure 24 of each of the first and second arms 14, 16.

Air is supplied to the first duct 15 and the second duct 17 via the columnar members 30 by the fan 38. The components 30 include heating elements for heating the air, as well as a set of elongated baffles 32 (shown in multiple angles in cross-section, substantially star-shaped), an airflow separator 34, and a diffuser grid 31, as shown in close-up in fig. 18.

The elongated baffles 32 are 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 directing structure 24. This is important to achieve a uniform air temperature at the outlet of the cellular air flow directing structure 24, and thus uniform drying over the entire hair section within the chamber 13. It is also possible to prevent the formation of hot spots in the air which could damage the hair. Thus, without such baffles, it may be desirable to reduce the hair heating power and thus the drying speed of the device.

The airflow separator 34 is aligned over the diameter of the cylindrical member 30 and is arranged to divide 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 is such that air is directed into the first duct 15 and the second duct 17 without causing a whistling of the air, thereby providing an acoustic benefit.

More particularly, the member 30 has a circular cross-section, the lower half of which (below the gas flow separator 34) corresponds to the cross-sectional geometry of the first duct 15. The upper half of the member 30 (above the flow separator 34) corresponds to the cross-sectional geometry of the second duct 17. As shown in the cross-section in fig. 8, when the second arm 16 is in the closed position, the second duct 17 fits closely around the upper half of the member 30 so that airflow can pass through the member 30 below and above the airflow separator 34 into the first duct 15 and the second duct 17 without leakage.

Thus, as shown in fig. 8, air enters the first and second ducts 15, 17 in a first direction D1 that is substantially parallel to the length of each of the first and second arms 14, 16.

As also shown in fig. 8, and as shown in the longitudinal perspective section of fig. 15, the airflow directing structure 24 within each of the first and second arms 14, 16 comprises a cellular structure having a plurality of cell walls. In the illustrated embodiment, the cellular structure has a hexagonal (honeycomb) structure, although such a geometry is not required and other geometries (e.g., as shown in fig. 16 and 17) may alternatively be used. However, it has been found that a hexagonal (honeycomb) structure is advantageous to maximize 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 illustrated embodiment, the cell width is about one tenth of the cell length.

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

More particularly, the gradual change in 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.

Fig. 8 also shows that the inner surface of each air flow directing structure 24 is offset from an imaginary centre line intermediate the first and second arms 14, 16 by a distance of 0.5mm to 4mm (preferably about 2mm) when the arms 14, 16 are in the closed position. The position of the imaginary centre line is the position where the hair 11 will cross the arm compartment 13 under tension when in use (e.g. as shown in fig. 9). This offset of each air flow directing structure 24 relative to the imaginary centre line advantageously creates an air flow restriction between the air and the hair in use to increase the air flow velocity around the hair, thereby accelerating drying.

As best shown in fig. 14, the airflow directing structure 24 also includes a plurality of airflow redirecting channels 28, the airflow redirecting channels 28 extending between longitudinal edges and respective longitudinal sides of the airflow directing structure 24. These channels 28 are configured to convey the airflow from the second direction D2 to a third direction D3 and a fourth direction D4, the third direction D3 and the fourth direction D4 being directions outward from the device substantially perpendicular to the length of the arms 14, 16, the fourth direction D4 being opposite the third direction D3. Fig. 13 also shows the airflow directions D3 and D4. Incidentally, as shown in fig. 14, the airflow guide structure 24 including the cellular (e.g., honeycomb) structure and the airflow redirecting channels 28, and the outward vents 26 in the third direction D3 and the fourth direction D4 may be integrally formed as a unitary structure, for example, by 3D printing.

Turning now to fig. 10, there is shown a further direction of airflow through the arms 14, 16 of the device 10 when the main body portion 12 facing the device is viewed in transverse cross-section.

Starting from the centre of fig. 10, it can be seen that air flowing in direction D2 passes from the plenum chambers 15, 17 into the inter-arm chamber 13 via the cells of the air flow directing structure 24.

The air then diffuses laterally and enters the air flow redirecting channel 28 before passing along the air flow ducts 19a, 19b, 21a and 21b and exits the device via vent 26 in the opposite directions D3 (through ducts 19a and 21a) and D4 (through ducts 19b and 21 b). As shown in fig. 10, the air flow ducts 19a, 19b, 21a and 21b extend behind the heating plates 20a, 20b, 22a and 22b mounted on the first and second arms 14 and 16, respectively.

For the sake of completeness, it should be noted that although the airflow directions D3 and D4 as they exit the vent 26 may be said to be "substantially perpendicular" to the length of the arms 14, 16, the total path followed by the air as it passes through the airflow redirection channel 28 and along the airflow channels 19a, 19b, 21a and 21b, and then through the vent 26, is not linear.

Advantageously, the vents 26 direct the exiting air towards the roots of the hair to dry the roots and create root lift.

Fig. 11 is a transverse cross-sectional view of the arms 14, 16 of the device 10 corresponding to fig. 10 in a closed configuration (around a hair 11) and facing the body portion 12 of the device. The features of the columnar elements 30, including the diffuser grid 31 and the elongated baffles 32 at the distal ends, are visible as viewed along the passages 15 and 17 toward the body 12. Other features of fig. 11 correspond to those identified in fig. 10 and described above.

Fig. 12 and 13 show (in longitudinal and transverse cross-sectional perspective views, respectively) the change in direction of the airflow due to the airflow directing structure 24 of the apparatus 10 and other features in each arm 14, 16.

As described above, the first airflow direction D1 is substantially parallel to the length of each of the first and second arms 14, 16 as air passes through the baffle 32 and into the first and second ducts (plenums) 15, 17 in the respective first and second arms 14, 16. The cellular air flow directing structure 24 then directs (i.e. diverts) the air flow inwardly from the first direction D1 to a second direction D2, inwardly into the arm compartment 13 formed by the arms 14, 16 in the closed position, through which, in use, the hair 11 passes.

The air then diffuses laterally and enters the air flow redirection channel 28, then passes along the air flow ducts 19a, 19b, 21a and 21b behind the heater plate, exiting the device via vents 26 in opposite directions D3 and D4.

Principle of the technology

As used herein, the expressions "drying the hair", etc. are to be understood as referring mainly to the removal of "unbound" water present on the outside of the hair upon wetting. This "unbound" water should be contrasted with "bound" water, which is present inside the individual hairs and which may interact with the hairs during the heat styling of the hairs. In the context of the present disclosure, it is not necessary to remove this "bound" water when drying the hair, although some bound water may be removed during the drying process. The bound water is typically further removed during the molding process.

Fig. 20 is a graph of hair sample temperature versus drying time, which is useful for understanding the principles of the technology relevant to this study. As the temperature of the hair increases, the hair undergoes a warm-up period, followed by a first drying period and a second drying period, as described below. The first drying period is primarily directed to removing unbound water and the second drying period is primarily directed to removing bound water.

"preheating period": at this stage, the ceramic heating plate is used to raise the temperature of the hair to a temperature at which the liquid undergoes a phase change during the drying period (points a to B). The plate surface cannot be operated at temperatures of 100 c to 135 c (nominally 120 c) before cavitation of water occurs on the plate (hissing).

"drying period 1": this stage is supported by a heated air flow to dry the unbound water on the hair (points B to C). If no freshly heated air flow supports evaporation, the hair will cool down quickly and the drying rate slows down.

"drying period 2": this stage (points C to E) occurs when the bound water on the hair evaporates and is driven from within the hair fibers.

Shaping/straightening can be achieved when a force is applied to the fibers and the bound and unbound water is driven off.

Problems and solutions provided by this study

In this study, the inventors considered the following (and other issues) and provided the following solutions:

problem 1-reduce the fan airflow and air heating power to fit in the user's hand

The inventors have determined that drying hair with heated air is generally an inefficient use of energy, although conventional blower technology is efficient in converting electrical energy to a high temperature air stream. Furthermore, the use of heated air alone to dry hair is very inefficient, with most of the energy being dissipated from the hot air into the atmosphere. To dry hair faster, conventional blowers utilize air heating to increase the drying rate by employing higher and higher speed motor and fan technology, using higher air pressure and greater volumetric flow. However, this results in reduced energy efficiency, increased unit cost, and increased noise levels.

On the other hand, the use of a conductive heating plate is a very efficient way of heating water and hair to be dried, helping to promote a fast drying, compact and quiet product. However, liquid water in contact with the metal plate causes an audible cavitation sound (hissing sound) at temperatures between-100 ℃ and 143 ℃ (nominal), which leads to the perception of damage. Hair temperatures in excess of 143 c may result in hair degeneration.

One possible solution to this is to combine heated air blown through a conductive heating plate, but this creates a very large resistance to air flow, presenting additional challenges. Thus, inefficient high speed motor technology would be required to achieve the air flow pressure required to move the hair through the hair and plate).

The solution provided by the present study is to enclose the hair within a heated air plenum 13 between conductive heating plates 20a, 20b, 22a, 22 b. This enables the hair to be heated efficiently to evaporate more quickly towards the phase transition temperature of water at plate temperatures of-100 ℃ to 143 ℃ (nominally 120 ℃), avoiding cavitation and damage. Furthermore, a heated plenum temperature of 125 ℃ to 175 ℃ (nominally 150 ℃) enables phase change and evaporation to be effectively supported and maintained without cavitation.

Problem 2-minimization of air temperature range and air heating power due to large variation in hair airflow resistance

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

The solution provided by the present study is that the plenum chamber 13, which is closed around the hair, enables heated air to pass around the hair (not just through the hair segment), thereby reducing the airflow resistance range of the system. This helps to reduce the heater power and power requirement range for conditioning the air temperature, thereby improving energy efficiency and reducing product size and cost.

By reducing the range of resistance required by the airflow of the system, it is possible to use a low speed motor/fan, thereby helping to improve the energy efficiency of the fan and reduce sound and cost.

Furthermore, by designing the system resistance to precisely meet the air flow and temperature requirements for drying hair when closed, the air temperature of the product when open is made lower, thereby helping to improve the drying experience for the user and reduce energy losses, and reducing the physical size of the air heater, which would otherwise make the product larger and less usable.

Problem 3-achieving uniform air velocity and changing the air direction at the hair-air interface

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

The solution provided by the present study is to provide an airflow path that includes various features for directing or diverting airflow, including:

an airflow separator 34, the airflow separator 34 separating the airflow to the first arm 14 and the second arm 16. The flow separators 34 also prevent excessive or uneven temperature increases at the edges of the sections. It should be noted that the air flow separator 34 may also be made larger and of a flexible material to expel air to the second arm 16 when the device is in the open state. This prevents air from blowing hairs away from the heating plates 20a, 20b, 22a, 22b when the device is in the open state, and prevents hairs from restricting the air outlet in the open state, resulting in increased air flow restrictions and resistance in the system, which may otherwise lead to overheating and hair damage.

Inflatable chambers 15, 17 in each arm 14, 16, the inflatable chambers 15, 17 being shaped to allow airflow to fill each arm 14, 16, thereby making the airflow exiting the cells of the cellular airflow directing structure 24 more uniform.

The width of the cross-section of the cellular airflow directing structure 24 is reduced relative to the width of the arm 14, 16 on which it is located.

An airflow directing structure 24 for each arm 14, 16, the airflow directing structure 24 having a cellular (e.g. honeycomb or louvered) structure extending into the inflatable chambers 15, 17 within 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 from the hinge 18. This gradual change in cell depth causes the air flow to turn toward inflatable chambers 15, 17 and exit from inflatable chambers 15, 17 at a uniform airspeed.

An opening offset distance of 0.5mm to 4mm (nominally 2mm) from the nozzle outlet of the air flow directing structure 24 to the hair (when the first and second arms are in the closed configuration) which serves to create an air flow restriction between the air and the hair to increase the air flow velocity around the hair, thereby accelerating drying. The open cross-section between these features allows air to pass around the hair to the outlet of the plenum chamber without having to pass through the hair (which may otherwise restrict airflow).

Problem 4-achieving uniform air temperature in the air stream

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

The present study provides a solution to locate features such as baffles 32 in the air stream outside of the ring of heater outlets, or inside the air stream, to induce turbulence in the heated air stream and promote better mixing of the air in the air stream before passing through the air stream separator 34. As a result, a more uniform air temperature distribution throughout the airflow can be achieved.

Problem 5-drying of the hairy root and producing root lift

The inventors have determined that it is desirable to dry the hair at the root, for example, in order to produce a root lift.

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

Problem 6-plate cavitation (hissing) limitation of very wet hair at around 100 ℃ to 125 ℃

The inventors have determined that plate cavitation (hissing) of very wet hair at around 100 ℃ to 125 ℃ limits the drying speed.

The solution provided by this study is based on the following recognition: as the unbound water on the hair evaporates, the plate temperature may be raised to a higher temperature to heat and dry the hair faster and more efficiently.

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 accelerate the drying rate. This may be achieved by providing temperature sensors in the device 10, for example at the following locations:

position "A" -upstream of the air-hair interface

Position "B" -downstream of the air-hair interface

Position "C" -sensing the temperature of the conductive heating plate, and/or Power sensing

A very large temperature difference between these sensors will indicate that the arms 14, 16 are open, since air is not directed through position B. The open condition of the arms 14, 16 can also be sensed by measuring the electrical power required to raise the air temperature, as the airflow system resistance will also change between open, closed and closed with hair closed conditions.

The thermal load of the plate at position C will indicate the presence of hair in the product (from power and/or temperature sensing).

A high temperature difference between the sensors will indicate that water is evaporating (drying the hair) and thus that the hair is wet. On the other hand, a low temperature difference between the plates will indicate that a minimum phase change is occurring and the hair is therefore "dry".

Problem 7-increase the Cooling Rate of the heating plate

As described above, the present inventors have determined that increasing the temperature of the heating plate in response to the presence of unbound water in the hair enables faster drying. However, if the user moves the device to a more wet hair section, it is desirable to cool the plate of the product very quickly to prevent cavitation (hissing) and/or hair damage.

The present study is based on providing a solution to this problem by actively cooling the heating plate with air (from a fan) passing through the heating plate. This enables accelerated cooling of the plate back to 100 ℃ to 125 ℃. The air temperature may be controlled, for example, using an NTC (negative temperature coefficient) device and TRIAC control of the air heater.

A PTC (positive temperature coefficient) heater may also be beneficial in achieving a simple and compact conductive heater with an air heat sink.

Problem 8-regulating the temperature of air contacting the hair in the open position

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 loss dissipated to the atmosphere when the air outlet is restricted by the hair during loading, thereby delivering cooler feeling air to the user. It is also desirable to regulate the air temperature to achieve rapid drying and minimal hair damage.

In response to this problem, the present study provides a solution to place an NTC (negative temperature coefficient) device at the air heater outlet, between the air heater and the hair contacting surface, with the preferred location being 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 an increase in temperature difference caused by increased airflow resistance when the arms are open. If the upper temperature limit is reached, TRIAC control may be used to adjust the power provided to the air heater.

Problem 9-revitalizing the hair when not washed

The inventors have determined that a user may desire a fresh wash and blow dry feel when there is no time, ability, or desire to wash and dry the hair.

In response to this problem, the present study provides a solution to enable fragrance to be emitted into the airflow generated by the device 10, thereby imparting a fresh scent to the hair. To achieve this, a user-replaceable piezo-atomizer and/or a simpler fragrance reservoir and wick may be used to achieve phase exchange (liquid to gas) into the air stream and thus onto the user's hair.

Problem 10-making compact air heaters to make compact overall product forms

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

In response to this problem, the present study provides a solution to recognize that PTC (positive temperature coefficient) heaters enable new air heaters that incorporate a cellular (e.g., honeycomb) airflow directing structure 24 with an air heater as a single product component. This therefore combines the functions of the two parts, making the overall product smaller and more compact. Furthermore, this may also eliminate the need for additional thermal fuses (and their associated costs) due to the PTC effect.

Problem 11-portability

The inventors have determined that consumers desire products suitable for "out-of-the-home" use, for example away from home, or in any case away from a socket (e.g. in a bathroom).

By virtue of the above energy savings, the present study enables Low Voltage (LV) devices 10 to be used for safe operation in bathrooms, and/or enables devices 10 to be used cordless (e.g., with rechargeable batteries) and/or compact stand-alone power supplies.

Modifications and substitutions

The 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 to the embodiments described above may be made while still benefiting from the disclosure embodied therein. Therefore, it is to be understood that the present disclosure is not limited to the described embodiments, and encompasses modifications apparent to those skilled in the art lying within the scope of the appended claims.

In the above described embodiments, the first arm 14 and the second arm 16 each contain a respective airflow duct 15, 17 and are provided with a respective airflow directing structure 24. However, in alternative embodiments, only one of the arms 14, 16 may be provided with the airflow duct and airflow directing structure 24. Examples of such variations are described below and shown by way of example in fig. 27, 30 and 35. In other variations, the airflow directing structure(s) 24 may be omitted entirely.

In the above described embodiment, the heating plates are symmetrically disposed on either side of each of the arms 14, 16. However, as will be understood 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 conjunction with the air flow. Furthermore, an unheated plate 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 facilitates the drying/shaping process. Furthermore, as in the above-described embodiments, the use of a pair of heating plates advantageously allows for bi-directional/ambidextrous use of the device.

In the above-described embodiment, the airflow directing structure 24 of each of the first and second arms 14, 16 includes a cellular structure having hexagonal (honeycomb) cells configured to direct airflow from the first direction D1 to the second direction D2. However, in alternative embodiments, the unit cells of the airflow directing structure may have different shapes. For example, fig. 16 shows a longitudinal perspective cross-sectional view of an alternative cellular airflow directing structure 24a, in this case having rectangular cells in one linear dimension (the depth of the cells gradually increasing with distance along the structure in the same manner as the hexagonal cells described above). As another example, fig. 17 shows a longitudinal perspective cross-sectional view of another alternative cellular airflow directing structure 24b, in this case having rectangular cells in two linear dimensions (the depth of the cells also gradually increasing with increasing distance along the structure).

In the above described embodiment, the air flow is heated, for example, by a heating element in the apparatus body 12 downstream of the fan 38. However, in alternative embodiments, the means for heating the airflow may comprise the airflow directing structure 24 itself, which is formed from 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 air at a sufficiently high flow rate to dry the hair.

Throughout the description and claims of this specification, the words "comprise" and "contain" and variations of the words, for example "comprising" and "comprises", mean "including but not limited to", and are not intended to (and do not) exclude other components, integers or steps.

Other alternative features have been developed in connection with the above-described embodiments to solve certain additional problems or to provide certain additional functions. These other alternative features (and, where used, the specific problems that these other alternative features solve or provide additional functionality) will now be described in detail.

First, in order to achieve rapid drying and high quality styling (i.e., a high level of shine, color retention, and styling durability), the hair tresses that pass through the active styling area (i.e., the styler head) should be subjected to uniform drying and heating across the entire width of the hair tresses. To do this well, the following five considerations have been found to be important:

(1) the air flow distribution through the active styling area (i.e., the styler head) should be as uniform as possible.

(2) The temperature distribution of the air through the molding zone should be as uniform as possible.

(3) The root lift vents should be arranged to optimize their function.

(4) When the styler is closed around a hair and used, air should not be allowed to escape from the ends of the styler.

(5) The molder should work equally well in any country. There are often minor differences in mains voltage between countries, which may result in variations in motor speed and available power to the air heater, and therefore the energy delivered to the hair may be different. This problem should be solved so that the energy transfer is the same in any country regardless of the grid voltage, thus ensuring consistent and uniform performance worldwide.

Of course, the safety and quality of the product are also of utmost importance, so the following problems are also considered and solved:

(6) when the styler is operated, the flow of hot air should not be allowed to the user's hand.

(7) Accumulation of residual heat in the air heating component (and associated electronics) should be avoided, preventing accidental shutdown or failure of heat sensitive components such as thermal fuses, particularly when the device is switched from on to off.

The above points (1) to (7) are solved by the following other features:

other features 1-providing more uniform air flow distribution throughout the active styling region (i.e., the styler head)

In the above embodiments, the design of the cellular airflow directing structure 24 attempts to provide uniform airflow by using a honeycomb (or other cellular) structure in which the depth of the cells gradually increases towards the distal end of the device to effectively "pocket" more air as it travels down the length of the head in a direction perpendicular to the direction of the depth of the cells. While this technique is helpful, it has been found that with the cellular airflow directing structure 24 described above, a disproportionate amount of airflow is still emitted near the distal tip of the device.

To illustrate this, fig. 21 shows the above-described cellular airflow directing structure 24 in the lower arm 14 of the apparatus, in which the hexagonal cells are of equal diameter. Consistent with fig. 21, fig. 22 shows the airflow distribution along the length of the airflow directing structure 24, i.e. the average ejected air rate at each longitudinal position along the airflow directing structure 24 (from the tip end to the handle end along the head of the device). It can indeed be seen from fig. 22 that a disproportionate amount of airflow exits the airflow directing structure 24 near the distal end of the device as airflow accumulates towards the device end. This is disadvantageous for a uniform styling and can lead to a reduction in the gloss of the hair and, due to the faster air jet velocity at this location, a single hair strand is blown in an undesired direction (a so-called "fly away" strand), especially near the end of the device.

To address this issue, referring now to fig. 23, in an alternative (improved) airflow directing structure 24, the diameter of the honeycomb cells gradually decreases toward the distal tip of the device to restrict airflow. As noted above, the depth of the cells also gradually increases toward the distal tip of the device. Fig. 24 shows the resulting airflow distribution along the length of the airflow directing structure 24, and as can be seen, a more uniform airflow distribution is achieved in which the airflow peaks near the midpoint of the airflow directing structure 24 (i.e., intermediate the distal end of the head of the device and the end of the handle). This air flow distribution achieves a more even styling, a brighter hair shine, and a reduction in individual strands of hair blown in undesired directions.

Fig. 25 provides exemplary dimensions for the hexagonal cell of the alternative airflow directing structure 24. It can be seen that the cell diameter near the handle of the styler is 4.2mm, the cell diameter near the midpoint of the airflow directing structure 24 is 3.9mm, and the cell diameter near the distal end of the device is 3.3 mm. These dimensions are by way of example only and may be different in other embodiments (while still tapering the cell diameter towards the distal tip 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.

Other features 2-providing a more uniform temperature distribution of air through the styling region (i.e., the styler head)

The temperature of the air passing through the styler head should be as uniform as possible to ensure that the entire hair tress is dried evenly, resulting in better hair fiber alignment and improved shine and style durability. It has been found that the above-described structure (see, e.g., fig. 7) which allows air from the component 30 to enter the first air flow duct 15 (disposed within and along the first arm 14) and enter the second air flow duct 17 (disposed within and along the second arm 16) does not provide the desired uniform temperature distribution. The reason for this is that the manner in which the airflow entering the ducts 15, 17 is generated, and the design of the heater, in particular the annular configuration of the heating element, results in a cooler central core of the airflow.

The result of this problem is that a temperature difference of over 30 c of the injected air can be observed from one end of the air flow guiding structure 24 to the other. For example, in representative experimental testing, a jet air temperature of 51 ℃ was measured near the proximal end of the air flow directing structure 24 (i.e., near the handle), a temperature of 71 ℃ was measured near the midpoint of the air flow directing structure 24, and a temperature of 86 ℃ was measured near the distal end of the air flow directing structure 24 (i.e., the tip of the device).

A similar situation is shown in fig. 26, where heated air is emitted near the distal end of the air flow directing structure 24 and cool air is emitted at the proximal end of the air flow directing structure 24. This is because the annular configuration of the heating element 40 (within the heater assembly 44) results in heated air zones being generated adjacent the heating element 40 and a cooler central core of air being generated between the heated zones.

Incidentally, it should be noted that fig. 26 (and subsequent fig. 27, 30 and 35) shows a variation of the first arm 14 in which all of the incoming airflow is directed along the first airflow duct 15 and thence through the airflow directing structure 24. That is, in this example, second arm 16 does not include a second air flow conduit for delivering air to the molder head (but may still include an air flow directing structure in communication with inter-arm chamber 13 for receiving air ejected from first arm 14). Conversely, in another variant, all of the incoming airflow may be directed within the second arm 16 along the second airflow duct 17 and not along the first arm 14. This variant makes the manufacture of the whole device easier and also improves the air flow performance, since it is avoided that the opposing air flows from the first duct 15 and the second duct 17 collide with each other and cause turbulence in the inter-arm chamber 13, and also provides a well-defined "escape route" for moisture-laden air.

Referring to fig. 27, the problem of uneven temperature distribution described above may be solved by providing an airflow mixer 42, in this case in the form of an airflow redirector or separator, in the vicinity of the end of the heater assembly 44, before the airflow duct 15. The airflow mixer 42 mixes the heated air (from near the heating element) with the cooler air center core to provide a more uniform flow of heated air along the airflow directing structure 24. The air flow mixer 42 may be generally conical or conical as shown, or other shape to create turbulence and mixing of the air within the air flow.

As the air flow mixer 42 removes or reduces the cold air core, the difference in temperature of the injected air from one end of the air flow directing structure 24 to the other can be significantly reduced. For example, in a control experimental test in the presence of the air flow mixer 42, a jet air temperature of 68 ℃ was measured near the proximal end of the air flow directing structure 24 (i.e., near the handle), a temperature of 82 ℃ was measured near the midpoint of the air flow directing structure 24, and a temperature of 80 ℃ was measured near the distal end of the air flow directing structure 24 (i.e., the tip of the device). Thus, in this case, the temperature difference from one end of the airflow directing structure 24 to the other end is only 12 ℃.

Fig. 28 is a perspective view of the heater assembly 44 shown in fig. 27, showing the air flow mixer 42 in the center. Similarly, fig. 29 is a transverse plan view of the heater assembly 44 of fig. 28, and also shows a view of the heating coil 40.

Other features 3-improving root lift vent function

In the above embodiment, as shown in fig. 10, for example, root lift vents 26 are provided along either side of the head of the molding head and extend parallel to the plane of the heating plates 20a, 20b, 22a, 22 b.

However, referring now to fig. 30, further development work has found that improved hair root lift 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 the direction of D3 'and D4', rather than parallel to the plane of the heating plates. This means that the air flow directions D4 'and D3' are not opposite on either side of the styler head (as opposed to the directions D3 and D4 shown in fig. 10). Conversely, the air flow directions D3 'and D4' are at about 90 ° to each other on either side of the molding head. Other angles between the airflow direction D3 'and D4' of the air jet from the root lift vents are possible.

It has been found that it is advantageous to have the root lift vents 26 oriented at an angle that is not parallel to the plane of the heating plates 20a, 20b, 22a, 22b, because when the root lift air flow is parallel to the heating plates, it has been found that "fly off" hair strands are created and alignment of the hair fibers is reduced, thereby reducing the end result of shine and style durability. Thus, an angle of about 45 ° has been found to reduce the creation of "fly-away" hair strands, while still providing a flow angle that makes root lift easier for the user. If the angle is much larger than 45 deg., it becomes more difficult to generate root lift.

From the cross-sectional view of fig. 30, it should also be noted that in this variant of the styler head, the incoming air flow flows only along the first air flow conduit 15 and then (in direction D2) through the air flow directing structure 24 and into the inter-arm chamber 13. Thus, in this variation, second arm 16 does not include a second air flow conduit for delivering air to the molder head, but still includes an air flow redirection channel 28 for receiving some of the air ejected from first arm 14 and delivered through inter-arm chamber 13 via air flow guide structure 24.

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

Other features 4 — reduction of air escape from the distal tip of the molder

In the above embodiments, it has been found that when the styler is closed with hair between the heater plates, air may escape from the distal end of the styler, particularly at the ends of the heater plates. It has been found that this reduces the drying rate because less air passes through the hair strands and also causes fiber alignment problems.

However, referring now to FIGS. 31 and 32, after further development work, the problem of air escaping from the distal tip of the styler has been addressed by: mutually opposing spring-loaded thermally non-conductive (e.g., plastic) seal elements 48 are provided on the top molder arm 14 and the bottom molder arm 16 at the distal end of the apparatus. The sealing elements 48 are flat and also raised 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 ends of the styler along the heating plates. The spring by which each sealing element 48 is mounted allows a different amount of hair to be placed between the heating plates and still maintain the seal.

Other features 5-achieving consistent Performance worldwide

It is desirable that the molder product should have substantially the same performance wherever used in the world, even though the power grid voltage may vary from country to country. The mains voltage variation affects in particular the temperature of the heated air in the apparatus, since the air is heated using standard resistance wire heaters, and the electrical power consumed by such heaters and converted into heat is a function of the voltage. It is therefore desirable to ensure that the energy delivered to the air is the same, regardless of where in the world the device is located, to ensure that the drying rate is the same and that the product does not damage the hair fibres.

Control of the energy delivered to the air can be achieved in various ways, for example by varying the fan speed (which is undesirable as 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 technology while keeping the fan speed constant. For example, standard zero-crossing switching techniques employing triacs may 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 heat output of the heater element (and more generally of the device) can be controlled irrespective of variations in the local mains voltage.

Other features 6-preventing hot air from flowing to the user's hand while operating the moulder

Assuming that the temperature of the air can exceed 100 c for safety and comfort, the air should not flow back to the user's hands. In internal testing of earlier prototypes using modelers, it was found that during moulding, hot air could escape from the end of the heating plate closest to the handle/hinge and risk causing discomfort to the user.

To address this problem, and referring to fig. 33 and 34, a ramp-like airflow deflector feature 50 (also shown in fig. 32) has been developed for inclusion in the proximal end (i.e., handle end) of each of the pair of heated plates (i.e., plates 20a and 20b, or plates 22a and 22b) to prevent the heated air from escaping back toward the user's hand. The ramp-like shape of the deflector 50 is important for two reasons: air is prevented from passing backwards and the user's hair is not caught during styling. In contrast, the standard "block" form risks creating pinch points that pull and capture the user's hair. The ramped design of the deflector 50 can prevent this from occurring and also redirect the backflow air (that would otherwise escape toward the user) toward the opposite arm of the device to prevent discomfort to the user's hand.

Further feature 7-avoidance of residual heat build-up in the air heating part (and associated electronics), in particular when the device is switched from on to off

For safety reasons, modeler devices often contain a thermostat and a thermal fuse, either of which may cause the device to stop working when tripped (or, in the case of a thermal fuse, when blown). The thermostat is resettable and is designed to prevent accidental blockage of the air inlet to the appliance or inadequate cleaning of the filter. If the thermostat trips, it can be used again once the equipment has cooled down.

However, thermal fuse blowing is a more permanent problem (requiring replacement of the thermal fuse) and is designed to aim at avoiding equipment uncontrollable catastrophic failures, such as commutation failures in triacs driving air heaters. Thermal fuse failure can result in the product being unusable prior to replacement of the thermal fuse. Therefore, it is undesirable for the thermal fuse to fail during normal and safe use.

In internal testing using early prototypes of modelers, it was found that when the unit was switched from on to off (i.e. at the end of the period of use) and the internal fan was thus stopped, the temperature peaks of the air heating components within the thermostat and thermal fuse regions could reach high temperatures. After a number of operating cycles and extended periods of time, such temperature spikes may cause the thermostat to trip or the thermal fuse to blow, particularly in extreme cases of filter plugging. (furthermore, the activation temperatures of the two components differ greatly from the nominal activation temperature and degrade with aging.) tripping of such a thermostat or blowing of the thermal fuse can cause an undesirable failure of the safety device that otherwise would be operating properly.

One way to solve this problem is to have the internal fan continue to operate in a so-called "ramp-down" mode when the device is switched from on to off. Thus, the fan will continue to operate for a shorter period of time to reduce the residual heat in the heating components and associated electronics. That is, a fan in a slow descent mode may remove excess heat from the system by passing an airflow over the components.

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

Referring to fig. 35, this problem has been solved by: an initial gas flow separator 52 is provided at the inlet of the heater assembly 44. Airflow separator 52 has a generally conical or conical shape to direct the incoming airflow from the fan toward heating coil 40 (rather than simply passing along the center of heater assembly 44). By specifically directing the incoming airflow to the heating coil 40 in this manner, more efficient heat transfer from the coil 40 to the incoming airflow is provided during use. In addition, since the coil 40 operates more efficiently, more heat is transferred from the coil to the incoming airflow, and therefore less heat is accumulated in the coil (and associated electronics) itself, making it generally cooler. Therefore, less residual heat is present in the heating system when the device is switched from on to off. Therefore, even if the fan is suddenly turned off, the temperature peaks to which components such as the thermostat and the thermal fuse are exposed are not so severe as to be tripped or blown.

To further illustrate this point, FIG. 36 shows a graph of internal air temperature as a function of time in the region of a thermostat (lower line) and a thermal fuse (upper line) in a molder apparatus having an airflow separator 52. The graph spans the point where the device switches from on to off and the internal fan stops. It can be seen that at the moment the equipment is switched off and the fan is stopped, a moderate thermal spike of about 80 ℃ is experienced near the thermostat and the thermal fuse, reaching a maximum temperature of about 140 ℃. The thermal spike is within the allowable operating temperature of the components and does not cause the components to trip or fuse.

By way of contrast, fig. 37 shows a corresponding plot of internal air temperature as a function of time in the region of the thermostat (lower line) and thermal fuse (upper line) in a test molder device without the airflow separator 52. Again, the graph spans the point where the device switches from on to off and the internal fan stops. It can be seen that at the moment the device is turned off and the fan is stopped, a more pronounced thermal spike of about 100 ℃ is experienced near the thermostat and the thermal fuse. A maximum temperature of about 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 the airflow separator 52.

Fig. 35 also shows the gas flow mixer 42 according to fig. 42 to 47, although the gas flow mixer 42 and the gas flow separator 52 do not necessarily exist simultaneously. However, if both the air flow mixer 42 and the air flow separator 52 are present, a synergistic advantage can be realized in that the incoming air is heated more efficiently and the heated air is delivered to the user's hair more evenly.

Indeed, by implementing all of the above "other features" 1 through 7 in a single apparatus, a well-functioning molder apparatus with many synergistic advantages may be obtained. However, any one of the "other features" 1 to 7 may be omitted if necessary. Indeed, in the broadest sense, any of the "other features" 1 to 7 should not be considered essential to the present disclosure, the scope of which is defined by the appended claims.

Claims (40)

1. A device for drying and styling hair comprising:

first and second mutually opposed arms adapted to be moved between an open configuration for receiving a length of wet hair therebetween and a closed configuration adjacent the hair so as to form, in use, an inter-arm chamber through which the hair passes when the arms are in the closed configuration, and wherein an air flow duct is provided in and along at least one of the first and second arms; and

means for delivering an air flow along a conduit within the at least one of the first and second arms and subsequently into the inter-arm chamber.

2. The device of claim 1, wherein one or both of the arms further comprises an airflow directing structure arranged to receive the airflow from the respective duct and direct the airflow from a first direction substantially parallel to the length of the respective arm to a second direction, the second direction being from the respective arm towards the opposite arm, so as to direct the airflow into the inter-arm chamber.

3. A device according to claim 2, wherein each of the first and second arms comprises a respective duct and a respective air flow directing structure, and the means for conveying an air flow is arranged to convey air along the duct within each of the first and second arms and subsequently through the respective air flow directing structure and into the inter-arm chamber.

4. The device of claim 3, wherein each airflow directing structure is offset from an imaginary centerline located intermediate the first and second arms when the first and second arms are in the closed configuration.

5. A device according to any one of claims 2 to 4, wherein the duct in the or each arm acts as a plenum through which the air flows into the respective airflow directing structure and thence into the inter-arm chamber.

6. The apparatus of 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 in the second direction.

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

8. The device of claim 6 or 7, wherein the diameter of the cells gradually decreases with increasing distance along the respective arm.

9. The apparatus of any one of claims 6 to 8, wherein the cellular structure has a honeycomb structure.

10. An apparatus according to any one of claims 6 to 9, wherein the or each airflow directing structure further comprises a plurality of airflow redirecting channels configured to convey the airflow from the second direction to third and fourth directions, the third and fourth directions being directions outwardly from the apparatus substantially perpendicular to the length of the arm.

11. The device of claim 10, wherein the airflow redirection channel extends between a longitudinal edge and a respective longitudinal side of the airflow directing structure.

12. The device of any preceding claim, further comprising mutually opposed plates arranged on the first and second arms, the mutually opposed plates being arranged to come together when the first and second arms are in the closed configuration.

13. The device of claim 12, wherein first and second plates are disposed on the first arm and respective opposing first and second plates are disposed on the second arm.

14. A device according to claim 12 or 13, wherein at least one of the plates comprises means for applying heat to the length of hair when the first and second arms are in the closed configuration, in use.

15. A device according to claim 13 or 14 when dependent on claim 10 or 11, further comprising airflow ducts extending behind the first and second panels of the respective arm, and arranged to receive air from the airflow redirection channel and direct airflow behind the first panel and substantially in the third direction through the vent outflow along the edge of the device, and to direct airflow behind the second panel and substantially in the fourth direction through the vent outflow along the edge of the device.

16. The apparatus of claim 15, wherein the airflow directing structure including the cellular structure and the airflow redirecting channels, and the outward vents in the third and fourth directions are a unitary structure.

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

18. An apparatus according to any one of claims 3 to 17, further comprising a flow separator arranged to divide the flow in the first direction into the ducts within the first and second arms.

19. The apparatus of claim 18, wherein the airflow separator comprises a flexible member.

20. A device according to any preceding claim, wherein the means for conveying an airflow comprises a fan.

21. The apparatus of claim 20, wherein the fan comprises a brushless motor.

22. The apparatus of claim 21, wherein the brushless motor is operable at speeds in excess of 30000 revolutions per minute.

23. The apparatus of claim 21 or 22, wherein the brushless motor has a power consumption of no more than 15W.

24. The apparatus of claim 23, wherein the brushless motor consumes about 3W of power during normal operation.

25. The apparatus of any preceding claim, further comprising means for heating the gas stream.

26. The apparatus of claim 25, wherein the means for heating the gas stream comprises an electric heating coil.

27. The apparatus of claim 26 further comprising a gas flow separator arranged to direct an incoming gas flow towards the heating coil.

28. The apparatus of claim 27, wherein the gas flow separator has a conical or conical shape.

29. The apparatus of any one of claims 25 to 28, further comprising means for performing pulse width modulation on electrical power applied to the means for heating the gas flow.

30. An apparatus according to any one of claims 25 to 29, further comprising means for inducing turbulence in the heated air stream before it reaches the inter-arm chamber.

31. The device of claim 30, wherein the means for causing turbulence comprises one or more baffles within the gas flow.

32. A device according to claim 30, wherein the means for inducing turbulence comprises an airflow mixing member arranged between the means for heating the airflow and the duct in the or each arm.

33. The device of claim 32, wherein the gas flow mixing member has a tapered or conical shape.

34. Apparatus according to claim 25 when dependent on claim 2, wherein the means for heating the airflow comprises the airflow directing structure, the airflow directing structure being formed from: the material generates heat when an electric current is applied to the material.

35. A device according to any preceding claim, further comprising one or more sets of flexible bristles on the first and/or second arms, outside or inside the inter-arm chamber, arranged to promote the application of uniform tension to hairs passing through the inter-arm chamber in use.

36. The device of any one of the preceding claims, further comprising mutually opposing spring-loaded sealing elements at a distal tip of each of the first and second arms for preventing air from escaping through the tip.

37. A device according to any preceding claim, further comprising at least one airflow deflector located on an 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 a user's hand.

38. The apparatus of claim 37, wherein the airflow deflector is ramp-shaped.

39. A method of drying hair using a device according to any preceding claim.

40. The method according to claim 39, further comprising using the device to style the hair substantially simultaneously with drying the hair.

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