CN117545402A - Hair care appliance - Google Patents

Abstract

An accessory for a hair care appliance has an air inlet, an air outlet. The attachment has a curved surface adjacent to and downstream of the air outlet, and a rib positioned such that the rib interacts with the air flow exiting the air outlet to align the air flow exiting the air outlet. The air flow exiting the air outlet generates a first force that attracts hair toward the curved surface and a second force that pushes hair away from the curved surface.

Description

Hair care appliance

Technical Field

The present invention relates to a hair care appliance and an accessory for a hair care appliance.

Background

Hair care appliances are commonly used for drying and styling hair. In the case of hair care appliances used to style hair to create a soft appearance, the presence of shorter or broken hair (sometimes referred to as fly-away) can affect the desired soft appearance.

Disclosure of Invention

According to a first aspect of the present invention there is provided an accessory for a hair care appliance, the accessory comprising an air inlet, an air outlet, a curved surface adjacent to and downstream of the air outlet, and a rib positioned such that the rib interacts with an air flow exiting the air outlet to align the air flow exiting the air outlet.

The accessory according to the first aspect of the invention may be advantageous in that the accessory comprises a curved surface adjacent to and downstream of the air outlet, and a rib for interacting with the air flow leaving the air outlet. The ribs are arranged to align the air flow exiting the air outlet before the air flow flows over the curved surface.

The attachment according to the first aspect of the invention may be advantageous because the inventors of the present application have determined that directing the air flow across the curved surface may create a negative pressure region near the curved surface that attracts long hair towards the curved surface and that the interaction of the air flow with the hair also pushes short hair away from the curved surface. This may result in shorter hair being pushed through longer hair, for example through the longer hair toward the side of the hair facing the user's head, thereby providing a compliant finish.

The attachment according to the first aspect of the invention may be advantageous because the inventors of the present application have determined that the ribs may modulate the airflow to provide a more laminar airflow across the curved surface, which may create a greater pressure differential between the negative pressure region and the surrounding air, thereby helping to draw long hair towards the curved surface. As the airflow turns, the airflow typically separates, becoming more turbulent. The inventors of the present application have determined that ribs help reduce airflow separation when the direction of airflow is changed. The inventors of the present application have also determined that the ribs can reduce noise generated by the accessory during use by reducing airflow separation.

The attachment may be configured such that the air flow exiting the air outlet generates a first force that attracts hair toward the curved surface and a second force that pushes hair away from the curved surface. This can achieve a compliant finish by drawing long hair toward the curved surface in the manner described above, while pushing short hair away from the curved surface through the long hair. The accessory may be configured such that, in use, a region of negative pressure is created in the vicinity of the curved surface.

The ribs may be positioned to align the airflow before it flows over the curved surface. This may provide a more laminar airflow over the curved surface, which in turn may provide a more compliant finish in the manner described above.

The ribs may be positioned to divide the air flow exiting the air outlet in two to align the air flow. That is, the air flow may flow over either side of the rib. The ribs may divide the air flow into two centrally or may divide the air flow exiting the air outlet asymmetrically. The inventors of the present application have determined that splitting the air flow exiting the air outlet in two may provide a more laminar air flow over a curved surface, which may provide better smoothness performance.

The rib is movable relative to the air outlet. When the ribs are in different positions relative to the air outlet, this may result in the air flow leaving the air outlet having different characteristics, which may be used for different styling effects and/or for styling different hair types.

The air outlet may be elongate, such as a rectangular slot, which may provide a more laminar air flow exiting the air outlet. The ribs may be elongate, having a length at least as long as the length of the air outlet. This helps to increase the airflow alignment effect of the ribs as the ribs interact with the airflow along substantially the entire length of the air outlet.

The curved surface may comprise a Coanda surface, for example a convex surface, along which the airflow adheres due to the Coanda effect in use.

The curved surface may be substantially smooth and uninterrupted in form. This may allow hair to be wrapped around a curved surface in use.

The curved surface may comprise a radius of curvature in the range of 10mm to 60 mm. The applicant has found that such a radius of curvature is particularly effective in creating an air flow along the curved surface that creates a first force that attracts hair toward the curved surface and a second force that pushes hair away from the curved surface. The curved surface may comprise a substantially constant radius of curvature.

The attachment may comprise a connecting member for holding the rib in place in the air flow leaving the air outlet. The connecting member may assist in positioning the rib in a desired position relative to the air flow exiting the air outlet, for example in a position where the rib bisects the air flow exiting the air outlet.

The connection member may be rigidly connected to the rib such that the rib cannot move relative to the connection member. The connection member may prevent the ribs from moving in the air flow, e.g. rattling in the air flow, which may improve the alignment of the air flow by the ribs compared to a movable connection between the ribs and the connection member.

The air flow may pass between adjacent connection members to allow the ribs to interact with the air flow when the ribs are connected to the connection members. This may allow the ribs to divide the air flow exiting the air outlet into two.

The connecting members may be equally spaced along the length of the rib. This may help to reduce stresses in the ribs during operation of the accessory, and thus may reduce the risk of rib failure.

The rib and the connecting member may form a single body, such as a single integral component. This may provide a simpler arrangement than for example a corresponding arrangement in which the ribs and connecting members are a plurality of bodies, which may reduce the number of parts and costs, and may reduce the risk of failure in use.

The ribs may have smooth edges to reduce turbulence in the airflow, thereby reducing airflow separation and providing a more laminar airflow.

The accessory may include a channel for diverting the air flow exiting the air outlet towards the curved surface. The channels may allow the air flow to leave the air outlet in multiple directions while ensuring that the air flow turns to flow over the curved surface in the desired direction. The ribs may be positioned to smooth the airflow in the channel to provide a more laminar airflow across the curved surface.

The channel may include an arcuate surface for directing the flow of air across the curved surface. This helps to reduce the separation of the air streams to maintain a more laminar air stream.

The channel may define a channel outlet. The channel outlet may have a smaller open cross-sectional area than the air outlet. This may result in an increase in air velocity as the air flows through the channel from the air outlet to the channel outlet, which may facilitate hair styling as the air flows over the curved surface. Directing the air flow from a larger open cross-sectional area at the air outlet to a smaller open cross-sectional area at the channel outlet may create a converging air flow at the channel outlet, which may reduce noise and improve hair alignment performance.

The accessory may include a first channel for directing the airflow through the curved surface in a first direction and a second channel for directing the airflow through the curved surface in a second, opposite direction. The first and second channels may be arranged as described above. The first and second channels may allow a user to style hair using the accessory in different orientations.

The ribs may be movable relative to the air outlet to smooth the air flow in the first and second channels. This may allow the ribs to align the airflow across the curved surface in the first or second direction depending on the position of the ribs relative to the first and second channels.

The first channel may be arranged to direct the air flow through a first region of the curved surface and the second channel may be arranged to direct the air flow through a second, different region of the curved surface, the first and second regions of the curved surface being adjacent to and downstream of opposite sides of the air outlet. This may allow air to flow in opposite directions relative to the air outlet to allow a user to use the accessory in different directions to style hair on both sides of the head.

The first and second channels may include arcuate surfaces for directing the flow of air across the curved surfaces. This helps to reduce the separation of the air streams to maintain a more laminar air stream.

The accessory may comprise a switching member for switching the air flow between a first and a second channel, the switching member being movable from a first switching position in which the air flow passes through the first channel in a first direction through a first region of the curved surface but not through the second channel, to a second switching position in which the air flow passes through the curved surface in an opposite second direction through the second air outlet but not through the first channel. Thus, the accessory may be advantageous in that the accessory may be used in two different modes depending on the position of the switching member and the direction of the airflow across the curved surface. For example, the switching member may be placed in a first switching position to style hair on a first side of the head and placed in a second switching position to style hair on a second side of the hair.

The rib may be connected to the switching member such that the position of the rib relative to the first and second channels differs depending on whether the switching member is in the first switching position or the second switching position. This may help to ensure that the ribs are correctly positioned to align the air flow in the first and second channels. This may help the ribs to provide an optimized air flow alignment depending on the position of the switching member, so that the air flow may be smoothed by the ribs, regardless of which direction the air flow is directed around the curved surface. For example, the rib may be connected to the switching member by a connection member.

The rib may be positioned relative to the switching member such that air flows between the rib and the switching member. This may allow the ribs to divide the air flow in two as described above.

The rib may be rigidly connected to the switching member to ensure a correct position of the rib in the airflow so that the rib interacts with the airflow in a repeatable and reliable manner when the switching member is in the first and second switching positions. This also helps to simplify and ensure manufacturing.

The switching mechanism may form a seal between the first and second channels when the switching member is in the first switching position and the second switching position. This may reduce air loss as air flows through the respective first or second channels, thus increasing the airflow rate across the curved surface, thereby improving the performance of the accessory.

The switching member may be elongate, having a length at least as long as the length of the air outlet. This may reduce air loss as air flows through the respective first or second outlets, thus increasing the airflow rate across the curved surface, thereby improving the performance of the accessory.

The switching member may comprise an arcuate surface for diverting the airflow towards the first or second channel. That is, the switching member may be concave to help align the airflow as it turns toward the curved surface. The arcuate surface may help to maintain a more laminar flow of air.

The first and second channels may be substantially equal in size and shape. This may help to ensure that the air velocity across the curved surface is equal when the switching member is in the first switching position or the second switching position for the same air flow generated by the air flow generator. This also helps to ensure a uniform shaping of the two sides of the head.

The accessory may include a retaining mechanism for retaining the switching member in one of the first and second switching positions in the absence of a force being applied to the switching member by a user of the accessory. This may be advantageous because in the event that a user of the accessory does not apply a force to the switching member, the switching member is held in either the first or second position by the holding mechanism, allowing the user to change the orientation of the accessory without the switching member moving between the first and second positions. This may enable a user to style curls into hair by, for example, rotating the accessory.

The retaining mechanism may assist the user in using the accessory in various orientations without the switching member moving between the first and second switching positions.

The retaining mechanism may be arranged to retain the switching member in the other of the first and second switching positions when a force is applied to the switching member by a user of the accessory. This provides the user with assurance that the switching member is positioned correctly. This also ensures the correct direction of the air flow over the curved surface to provide better styling performance.

The retaining mechanism may comprise a releasable mechanical fastener for retaining the switching member in the first and second switching positions. For example, the releasable mechanical fastener may include a hook, detent, or snap. This may provide a simple way to hold the switching member in place until the user exerts a force, which may reduce the complexity of manufacturing and assembly.

The retaining mechanism may include a biasing element for biasing the switching member to the first and second switching positions. For example, the retaining mechanism may comprise a bistable spring that is stable in the first and second switching positions. The biasing element may help ensure that the switching member properly reaches the first and second switching positions to ensure proper switching of the airflow between the first and second channels. The biasing element may also increase the force required to move the switching member between the first and second switching positions, which may help prevent unintentional movement of the switching member.

The holding mechanism may include a first pair of magnetic elements configured to hold the switching member in the first switching position and a second pair of magnetic elements configured to hold the switching member in the second switching position. Each magnetic element of a pair is magnetically attracted to the other magnetic element of the pair. This may provide a simple mechanism for holding the switching member in a desired switching position and for a user to apply a force to the pair of magnetic elements to move the switching member to another switching position. For example, the first magnetic element of each of the first and second pairs of magnetic elements may be located in the switching mechanism, and the second magnetic element of each of the first and second pairs of magnetic elements may be located in an adjacent position within the accessory, the first magnetic element being attracted to the second magnetic element.

The minimum force required to overcome the retaining mechanism to move the switching member between the first switching position and the second switching position may be in the range of up to 5N. The minimum force required to overcome the retaining mechanism to move the switching member between the first switching position and the second switching position may be in the range 0.3N to 3N. The inventors of the present application have found that such a force is suitable for a user to apply deliberately to the switching member to move the switching member and to prevent accidental movement of the switching member during normal use of the accessory.

The accessory may include a body defining an air outlet and a curved surface. The body is rotatable relative to the rib between a first position in which the air flow exiting the air outlet interacts with the rib and a second position in which the air flow exiting the air outlet does not interact with the rib. This may allow the accessory to operate in different modes depending on the position of the body. For example, the accessory may be used for hair styling when the body is in the first position and for hair drying when the body is in the second position.

The first and second positions may be 180 degrees apart from each other. This may facilitate weight distribution within the accessory when the body is rotated between the first and second positions, thereby increasing the convenience of user operation. This may also enable the user to easily determine the mode in which the accessory is operating.

The accessory may include a spring plunger coupled to the body for positioning the body in the first and second positions. This may provide feedback to the user to confirm that the subject is in the first or second position. The attachment may further comprise a pair of ramps arranged to engage the spring plunger for limiting the range of movement of the spring plunger.

The body may be generally cylindrical. This may facilitate smooth rotation of the body between the first and second positions. The body may be configured to direct an air flow exiting the air outlet in a radial direction. That is, the body is configured such that the air flow exits the air outlet in a direction perpendicular to an outer surface of the body in which the air outlet is defined. This may facilitate easy use of the accessory when drying hair with the body in the second position.

The ribs may be arranged relative to the air flow exiting the air outlet to align the air flow diverted from the radial direction toward the curved surface when the body is in the first position. Thus, the ribs may provide a more laminar flow of air by smoothing the air flow as it turns toward the curved surface.

The curved surface may comprise an outer surface of the body. This may allow for a simpler connection than if the body and curved surface were separate. The curved surface may comprise a single curved surface extending from a first side of the air outlet to a second side of the air outlet, substantially the entire body. This may allow the body to rotate more smoothly relative to the ribs.

The first and second channels may be adapted to direct airflow in opposite directions around the curved surface of the body when the body is in the first position. This may allow the user to style the hair on different sides of the head.

The curved surface may comprise first and second regions located on opposite sides of the air outlet. The first channel is for directing air flow from the air outlet in a first direction through the first region and the second air outlet is for directing air flow from the air outlet in a second, opposite direction through the second region when the body is in the first position. The first and second regions may extend away from respective sides of the air outlet to such an extent that they abut on a side of the body opposite the air outlet to provide a continuous surface extending from the first side of the air outlet to the second side of the air outlet. This provides the benefit that the body requires a single air outlet while the attachment provides the ability to direct air across the curved surface in opposite directions to style hair on different sides of the head.

The accessory may include a user interface operable by a user to move the rib relative to the air outlet. The user interface may, for example, comprise one or more of a handle, a high friction grip surface, a knob, a button, a toggle key, or a touch screen. This helps to simplify the process of the user moving the ribs. For example, the rib may be connected to the switching member and the user interface may comprise a handle positioned on the switching member and movable by a user to move the switching member between the first switching position and the second switching position and thus move the rib relative to the air outlet.

The accessory may include a guide. The guide may include one or more of a rib, a channel, a switching member, and a retaining mechanism. This may allow the rib, channel, switching member and retaining mechanism to move relative to the air outlet to allow the accessory to operate in different modes.

The guide may be configured such that the second channel is blocked by the switching member when the switching member is in the first switching position, and the first channel is blocked by the switching member when the switching member is in the second switching position. This may help ensure that the air flow may only flow through the first or second region of the curved surface depending on the position of the switching member to provide a greater air flow in a desired direction over the curved surface.

The accessory may include a planar surface adjacent to and extending rearwardly from the channel outlet. The planar surface may be contained in a guide.

In the case of providing a non-planar surface extending rearwardly from the channel outlet, the compliant finish may be disturbed when the accessory is moved relative to the hair in use, which may be typical during styling operations. In the case where a roughened surface (e.g. comprising protrusions such as bristles) extends rearwardly from the channel outlet, such a roughened surface may interrupt hair that has been smoothed by the airflow from the channel outlet as the accessory moves relative to the hair in use. By providing a curved surface adjacent to and downstream of the channel outlet, and a flat surface adjacent to and extending rearwardly from the channel outlet, a compliant hair finish can be formed and maintained as the user moves the accessory relative to the hair in use.

The planar surface may also serve as a guide surface to ensure proper positioning of the accessory relative to the user's head so that the air flow exiting the channel outlet can provide the above-described function.

The planar surface may be substantially smooth and uninterrupted in form. The planar surface may comprise a height in the range 5mm to 20 mm.

The accessory may be configured such that the planar surface contacts hair extending rearwardly from the channel outlet when the accessory is moved relative to the hair in use, for example when the accessory is moved linearly in the direction of the hair from the root to the tip in use.

The planar surface may comprise a substantially planar surface. This may help to maintain a compliant hair surface as the accessory moves relative to the hair in use and may ensure that hair extending rearwardly from the channel outlet is supported by the surface.

The planar surface may be inclined relative to the plane of the channel outlet. This ensures that hair extending rearwardly from the channel outlet contacts the flat surface while hair downstream of the channel outlet is attracted towards the curved surface in use. The planar surface may be inclined relative to a plane tangential to the curved surface at a point of the curved surface immediately adjacent the outlet of the channel.

The attachment may include a pair of guide walls for guiding the airflow along the curved surface, the pair of guide walls upstanding from the curved surface. By providing a pair of guide walls extending outwardly from the curved surface, ambient air is prevented from striking the region of negative pressure created by the airflow flowing along the curved surface in use, and the attraction of hair to the curved surface can be increased compared to a similar arrangement, for example, without the guide walls.

Each guide wall may be curved in form, for example having a curvature following the curvature of a curved surface. The guide walls of the pair of guide walls may be opposite each other, for example such that a channel is defined between them, the curved surface forming a bed of channels. The pair of guide walls may be spaced apart from each other along the curved surface, for example at opposite edges of the curved surface. The spacing between the guide walls may substantially correspond to the length of the air outlet. The curved surface may be substantially smooth and uninterrupted between the pair of guide walls. This may allow hair to be entangled in use on the curved surface between the pair of guide walls.

The guide wall may protrude outwardly from the curved surface, e.g. the guide wall and the curved surface are integrally formed as a single piece. The pair of guide walls may have a height substantially equal to the height of the channel outlet. This ensures that in use a region of negative pressure is maintained along substantially the entire height of the air jet exiting the channel.

The pair of guide walls may comprise a height substantially equal to the height of the channel outlet in the region adjacent to the channel outlet. The inventors of the present application have found that maintaining a region of negative pressure in the region adjacent the outlet of the channel facilitates the generation of an air flow along the curved surface, which results in a first force being sufficient to attract relatively long hair towards the first surface, while also generating a second force to push relatively short hair away from the curved surface.

The radius of curvature of the pair of guide walls may be greater than the radius of curvature of the curved surface. For example, the radius of curvature of the pair of guide walls may be greater than the radius of curvature of the curved surface in the region adjacent to the channel outlet. This may ensure that the pair of guide walls provide their function in use in an area adjacent the respective first or second air outlet.

The pair of guide walls may include a height that varies along the length of the guide walls. The inventors of the present application have found that the guide wall provides the greatest influence in certain areas of the curved surface, for example in the area adjacent to the air outlet. The pair of guide walls may comprise a height that decreases in a direction away from the channel outlet. By lowering the height of the guide wall in a direction away from the channel outlet, less material is required to form the guide wall than, for example, a constant height guide wall. The pair of guide walls may comprise a height that tapers in a direction away from the channel outlet, for example such that there is no step change in height. Each of the pair of guide walls may include the same height, and may be substantially symmetrical about an axis that bisects a space between the guide walls.

The pair of guide walls may comprise a constant height. This may provide certainty that the negative pressure region created near the curved surface is not affected along the length of the curved surface.

The guide wall may extend around the body from the first channel to the second channel. The body may be configured to rotate within the pair of guide walls. This may help to stabilize the body relative to the guide to ensure smooth movement of the body between the first and second positions.

The channel outlet may be a fixed air outlet, such as an air outlet of a fixed cross-sectional area, length and/or width. This ensures that the airflow characteristics of the attachment are constant for a given flow rate of the airflow generated by the airflow generator, thereby ensuring that an airflow is generated along the curved surface that generates a first force that attracts hair towards the curved surface and a second force that pushes hair away from the curved surface. This ensures a constant air flow along the length of the air outlet, allowing the hair to be straightened by the attachment. This may also provide a simpler accessory with fewer moving parts compared to an accessory with a variable air outlet, thus reducing the risk of malfunction.

The curved surface may comprise a continuous surface extending between the first and second channels. Such a continuous surface may help attract hair to the curved surface when the accessory is used in multiple orientations.

The body may include an internal baffle for diverting the air flow from the air flow generator towards the air outlet, for example, approximately 90 degrees towards the air outlet. This may allow the main portion of the accessory housing the airflow generator to extend orthogonally relative to the air outlet, which may provide greater design flexibility and may be more ergonomic than an accessory in which the air outlet is aligned with the main portion of the accessory housing the airflow generator.

The accessory may include a heater for heating the airflow. This may provide increased styling flexibility and may allow, for example, the air flow to provide a drying function.

The accessory may include a handle unit within which the airflow generator is housed and an accessory releasably attached to the handle unit, the accessory including an air outlet, a curved surface and ribs. Providing the removable accessory may allow a user to selectively provide the functionality described herein.

According to a second aspect of the present invention there is provided a hair care appliance comprising an air inlet, an air outlet, an airflow generator for generating an airflow from the air inlet to the air outlet, a curved surface adjacent the air outlet and downstream of the air outlet, and a rib positioned such that the rib interacts with the airflow exiting the air outlet to align the airflow exiting the air outlet.

The hair care appliance may comprise a heater for heating the air flow. This may provide increased styling flexibility and may allow, for example, the air flow to provide a drying function. The heater may be configured to operate at a specific temperature depending on whether the body is in the first position or the second position.

The hair care appliance may comprise a handle unit in which the airflow generator is housed, and an accessory according to the first aspect of the invention, the accessory being removably attached to the handle unit. Providing a removable accessory may allow a user to selectively provide the functionality of the accessory described herein.

Optional features of aspects of the invention may be equally applied to other aspects of the invention where appropriate.

Drawings

Fig. 1 is a schematic view illustrating a hair care appliance according to the present invention;

fig. 2 is a schematic cross-sectional view through a handle unit of the hair care appliance of fig. 1;

fig. 3 is a schematic perspective view of an embodiment of an accessory for the hair care appliance of fig. 1, showing the accessory in a second mode;

FIG. 4 is a schematic cross-sectional view of the accessory of FIG. 3, showing the accessory in a second mode;

FIG. 5 is a schematic perspective view of the accessory of FIG. 3, showing the accessory in a first mode;

FIG. 6 is a schematic diagram illustrating forces generated by airflow through the accessory of FIG. 3 when used in a first mode;

FIG. 7 is a schematic top view of the accessory of FIG. 3, showing the accessory in a first mode and a first switching position;

FIG. 8 is a schematic top view of the accessory of FIG. 3, showing the accessory in a first mode and a second switching position; and

fig. 9 is a schematic exploded view of the accessory of fig. 3.

Detailed Description

A hair care appliance according to the present invention is schematically shown in fig. 1 and indicated generally at 10.

The hair care appliance 10 includes a handle unit 12 and an accessory 100 removably attached to the handle unit 12.

As schematically shown in fig. 2, the handle unit 12 includes a housing 14, an airflow generator 16, a heater 18, and a control unit 20.

The housing 14 is tubular and includes an air inlet 22 through which air flow is drawn into the housing 14 by the air flow generator 16 and an air outlet 24 through which air flow is exhausted from the housing 14. The airflow generator 16 is housed within the housing 14 and includes an impeller 26 driven by a motor 28. The airflow generator is configured to generate an airflow having a flow rate in the range of 8 to 18L/S (e.g., in the range of 10 to 16L/S). A suitable air flow generator is the dyson V9 digital motor produced by dyson technologies limited. A heater 18 is also housed within the housing 14 and includes a heating element 30 to optionally heat the air flow.

The control unit 20 comprises electronic circuitry for the user interface 32 and the control module 34. A user interface 32 is provided on the exterior surface of the housing 14 and is used to turn the hair care appliance 10 on and off to select a flow rate (e.g., high, medium, and low), and to select an air flow temperature (e.g., hot, medium, or cold). In the example of fig. 1, the user interface includes a plurality of slide switches, but other forms of user interface 32 are also contemplated, such as buttons, dials, or a touch screen.

The control module 34 is responsible for controlling the airflow generator 16 and the heater 18 in response to inputs from the user interface 32. For example, in response to input from the user interface 32, the control module 34 may control the power or speed of the airflow generator 16 to adjust the airflow rate of the airflow and control the power of the heater 18 to adjust the temperature of the airflow.

The accessory 100 is schematically shown in fig. 3-5 and 7-9.

The accessory 100 includes a body 102, the body 102 including an air inlet 108, an air outlet 110, a curved surface 104, and a plurality of internal baffles 114. The attachment includes a guide 120. When the guide 120 is aligned with the air outlet 110 of the body 108, the guide 120 directs an air flow from the air outlet 110 across the curved surface 104 of the body such that the air flow directed by the guide 120 generates a first force that attracts hair toward the curved surface 104 and a second force that pushes hair away from the curved surface 104.

The air inlet 108 comprises a generally circular aperture formed in the body 102, and the air inlet 108 is configured to receive an air flow from the air outlet 24 of the handle unit 12 when the accessory 100 is attached to the handle unit 12 in use. The periphery of the air inlet 108 includes attachment features for releasably attaching the accessory 100 to the handle unit 12. The attachment features may take many forms, not relevant to the present invention, and will therefore not be described again for the sake of brevity.

The air outlet 110 comprises a generally rectangular slot formed longitudinally along the curved surface 104 of the body 102. The air outlet 110 includes a series of baffles extending across the width of the air outlet 110. The baffles may help align the air flow exiting the air outlet 110 and may help prevent hair from inadvertently entering the air outlet 110.

Fig. 4 schematically shows a cross-sectional view of the curved surface 104. The body 102 is generally cylindrical and the curved surface 104 is a circumferential surface of the body 102. Thus, curved surface 104 is adjacent to air outlet 110 and downstream from air outlet 110. It should be appreciated that in other embodiments, the body 102 may not be generally cylindrical and the curved surface 104 may extend only partially around the body 102.

The body 102 is configured to direct the airflow exiting the air outlet 110 in a radial direction. The guide 120 is arranged to divert the air flow leaving the air outlet 110 from a radial direction towards a tangential direction of a region of the curved surface 104 adjacent to and downstream from the air outlet 110.

The curved surface 104 is substantially smooth and uninterrupted in shape so that no protrusions, recesses or holes are formed thereon. This can enhance the function of the accessory 100, which will be described below. The radius of curvature of the curved surface 104 is in the range of 10mm to 60mm, for example in the range of 15mm to 40 mm. In the presently preferred embodiment, the radius of curvature of curved surface 104 is in the range of 20 mm. The inventors of the present application have found that such a geometry of curved surface 104 may provide advantageous effects, as described below.

The plurality of internal baffles 114 are curved in form and extend in a direction from the air inlet 108 to the air outlet 110. The plurality of internal baffles 114 are configured to divert the airflow from the direction of the air inlet 108 toward the air outlet 110 such that the airflow is diverted from the air inlet 108 approximately 90 degrees toward the air outlet 110. This may enable the handle unit 12 to extend orthogonally relative to the air outlet 110, which may provide greater design flexibility and better ergonomics than, for example, hair care appliances in which the air outlet is aligned with the handle unit of the hair care appliance.

The body 102 is rotatable about its central longitudinal axis 103 relative to the guide 120 between a first position in which the air flow exiting the air outlet 110 is directed by the guide 120, as shown in fig. 5, 7 and 8, and a second position in which the air flow exiting the air outlet 110 is not directed by the guide 120, as shown in fig. 3 and 4. The direction of air flow from the air outlet 110 is indicated by arrow 101 in fig. 4, 7 and 8, which illustrate different operational configurations of the accessory 100.

The position of body 102 relative to guide 120 determines the mode of operation of hair care appliance 100. In this embodiment, when the body 102 is in the first position, as shown in fig. 5, 7 and 8, the hair care appliance 100 is configured to operate in the first styling mode, and the airflow is directed by the guide 120 through the curved surface 104. When the body 102 is in the second position, as shown in fig. 3 and 4, the hair care appliance 100 is configured to operate in the second drying mode, and the air flow exits the air outlet 110 toward the hair of the user.

The first and second positions of the body 102 are 180 degrees apart from each other. That is, the body 102 is rotated 180 degrees relative to the guide 120 to move between the first and second positions. In other embodiments, the first and second positions may be less than 180 degrees apart from each other.

The accessory 100 includes a handle 112 that protrudes from the distal end of the body 102. Distal is the end of the body 102 opposite the air inlet 108. The handle 112 is rigidly attached to the body and is rotatable by a user to rotate the body 102 relative to the guide 120 between the first and second positions. It should be appreciated that the handle 112 may be provided in any suitable form for user operation to rotate the body 102 relative to the guide 120, such as a toggle key, button, or touch screen. The handle 112 is contained within a cold tip that is relatively insulated from the heat of the airflow within the accessory.

As shown in fig. 5, 7 and 8, when the body 102 is in the first position, the guide 120 is arranged to divert the air flow exiting the air outlet 110 towards the curved surface 104. The inventors of the present application have found that the air flow attaches to curved surface 102 by the coanda effect. Referring to the schematic of the force interaction shown in fig. 6, when a bundle of hair is brought into proximity of the attachment 100, the long hair of the bundle of hair is attracted to the curved surface 102 by the force f_pull and wraps at least partially around the curved surface 102 due to the negative pressure area created by the air flow over the curved surface 102. However, the pressure gradient across the hair strand also causes a force f_push that causes some airflow directly through the hair strand. Due to the location of this force relative to the curved surface 102 and the rest of the hair bundle, the shorter hair is held only loosely at this point compared to the longer hair held in place on the curved surface 102. The shorter hair is blown through the hair bundle towards the user's head, while the longer hair remains in place outside the hair bundle, i.e. the part of the hair bundle facing away from the user's head. This provides a compliant finish to the hair after interaction with hair care appliance 10.

This effect can be optimized by appropriate modification of the geometries and parameters described herein. One such parameter that may improve efficiency is the speed of the airflow at the air outlet 110 of the accessory 100. In particular, excessive speed may cause shorter hairs to stick to curved surface 102 and thus not be pushed away by longer hairs, while excessive speed may be insufficient to first attract longer hairs to curved surface 102.

The guide 120 includes a first channel 122 defining a first air outlet 126, a second channel 124 defining a second air outlet 128, first and second planar surfaces 130, an inner housing 132 defining a bore 133, a pair of guide walls 134, a switching member 140, and a retaining mechanism 150, which will be described in greater detail below. It should be understood that in other embodiments, some of these features may be omitted.

The inner shell 132 is arranged to contact the curved surface 104 at least when the body 102 is in the first position. The inner housing 132 defines an aperture 133 corresponding to the air outlet 110 to allow airflow from the air outlet 110 to the first and second channels 122, 124. The inner shell 132 includes raised ridges on opposite sides of the aperture 133 that define a convexly curved surface for directing the airflow from a radial direction toward the curved surface 104 of the body 102, thereby providing a smoother flow path for the airflow and thus helping to reduce turbulence in the airflow.

The first channel 122 is arranged to direct the airflow in a first direction across the curved surface 104. With respect to fig. 7, this is in a counter-clockwise direction, as indicated by arrow 101. The second channel 124 is arranged to direct the airflow in a second direction across the curved surface 104. With respect to fig. 8, this is clockwise as indicated by arrow 101.

When the body 102 is in the first position, the curved surface 104 includes a continuous surface extending between the first and second air outlets 126, 128.

The first and second air outlets 126, 128 comprise rectangular grooves extending substantially parallel to the longitudinal axis 103 of the body. The first and second air outlets 126, 128 are substantially equal in size and shape. The first and second air outlets 126, 128 have the same open cross-sectional area, which is smaller than the open cross-sectional area of the air outlet 110. For the same airflow rate, this provides an increased airflow rate at the first and second air outlets 126, 128 as compared to the airflow rate at the air outlet 110, and a converging airflow at the first and second air outlets 126, 128.

The air outlet 110 and the first and second air outlets 126, 128 are fixed air outlets, each having a fixed cross-sectional area, length, and width.

The first and second air outlets 126, 128 each have a length in the range of 50mm to 150mm, for example 75mm to 85mm, and a height in the range of 2mm to 5mm, for example 3.0mm to 4.5 mm. This results in a total opening cross-sectional area of each of the first and second air outlets 126, 128 in the range of 140mm2 to 450mm2, for example in the range of 225.0mm2 to 382.5mm 2.

In the presently preferred embodiment, the width of the first and second air outlets 126, 128 is in the range of 77mm and the height of the first and second air outlets 126, 128 is in the range of 4.5 mm. The open cross-sectional area of the first and second air outlets 126, 128 is in the range of 346.5mm 2. The inventors of the present application have found that such dimensions of the first and second air outlets 126, 128 may provide advantageous effects, as will be described below.

Applicants have determined that a velocity in the range of 30m/s to 65m/s at the first or second air outlets 126, 128 may be particularly effective in generating an air flow along the curved surface 102 that generates a first force sufficient to draw relatively long hair toward the curved surface 102 while also generating a second force that pushes relatively short hair away from the curved surface 102. In a presently preferred embodiment, the air flow velocity at the first or second air outlets 126, 128 is in the range of 55 m/s.

Another parameter that may increase the efficacy of smoothing hair in the manner described above is the ratio of the airflow velocity at the first or second air outlets 126, 128 to the airflow velocity generated by the airflow generator 16. In the embodiments of fig. 5, 7 and 8, the ratio is in the range of 2.14 to 5.63, and in a particularly preferred embodiment, the ratio is in the range of 2.89. The applicant has found that this ratio is particularly effective in creating an air flow along curved surface 102 that creates a first force sufficient to draw relatively long hair toward curved surface 102, while also creating a second force that pushes relatively short hair away from curved surface 102.

Another parameter that may increase the efficacy of smoothing hair in the manner described above is the ratio of the flow rate of the air stream generated by the air stream generator 16 to the open cross-sectional area of the first or second air outlets 126, 128. In the embodiments of fig. 5, 7 and 8, the ratio is in the range of 0.01 to 0.10, and in a particularly preferred embodiment, the ratio is in the range of 0.04. The applicant has found that this ratio is particularly effective in creating an air flow along curved surface 102 that creates a first force sufficient to draw relatively long hair toward curved surface 102, while also creating a second force that pushes relatively short hair away from curved surface 102.

Another parameter that may increase the efficacy of smoothing hair in the manner described above is the ratio of the radius of curvature of the curved surface 102 to the air flow velocity at the first or second air outlets 126, 128. In the embodiments of fig. 5, 7 and 8, the ratio is in the range of 0.33 to 2.00, and in a particularly preferred embodiment, the ratio is in the range of 0.57. The applicant has found that this ratio is particularly effective in creating an air flow along curved surface 102 that creates a first force sufficient to draw relatively long hair toward curved surface 102, while also creating a second force that pushes relatively short hair away from curved surface 102.

The planar surface 130 is located adjacent the first and second air outlets 126, 128 and extends rearward from the first and second air outlets 126, 128 such that the planar surface 130 extends rearward from the edges of the first and second air outlets 126, 128. The planar surface 130 is inclined, for example, at an angle in the range of 3-10 degrees, relative to the respective planes in which the first and second air outlets 126, 128 are disposed. The planar surface 130 is generally planar in form and is substantially smooth and uninterrupted, e.g., without protrusions, recesses, or holes formed therein. The height of the flat surface 130 is in the range of 5mm to 20 mm. The function of the flat surface 130 will be described below. It should be appreciated that in embodiments where the guide 120 includes only one channel defining the channel outlets 126, 128, the guide includes a single planar surface 130 adjacent the channel outlets 126, 128 and extending rearwardly from the channel outlets 126, 128.

The pair of guide walls 134 serve to guide the airflow along the curved surface 104 and are disposed on opposite edges of the curved surface 104. The guide wall 134 stands from the curved surface 104. The guide wall 134 extends along the entire arc length of the curved surface 104. In this embodiment, the guide wall 134 extends around the body 102 to form a pair of rings within which the body 102 rotates. That is, the guide wall 134 extends from the first air outlet 126 to the second air outlet 128 from around the body 102. The guide wall 134 has a height that substantially corresponds to the height of the first and second air outlets 126, 128 and has a constant height along their length.

As described above, the pair of guide walls 134 extend along opposite edges of the curved surface 104. This effectively creates a gas flow channel, the pair of guide walls 134 acting as walls of the channel, while the curved surface 104 acts as a bed of the channel. The guide wall 134 inhibits interaction of ambient air with the airflow flowing along the curved surface 104 in use, which may maintain a negative pressure region created by the airflow flowing along the curved surface 104.

The accessory 100 includes a switching member 140 for switching the airflow between the first and second air outlets 126, 128. The switching member 140 is movable from a first switching position (as shown in fig. 7) to a second switching position (as shown in fig. 8). In the first switching position, and when the body 102 is in the first position, the airflow passes through the curved surface 104, through the first air outlet 126, and not through the second air outlet 128. In the second switching position, and when the body 102 is in the first position, the airflow passes through the curved surface 104, through the second air outlet 128, and not through the first air outlet 126.

The switching member 140 is arranged to form a seal between the first air outlet 126 and the second air outlet 128 to block the first or second passage 122, 124 when the switching member 140 is in the first switching position and the second switching position. In this embodiment, the edge of the switching member 140 is arranged to contact the inner housing 132 of the guide 130 to block the air flow to the respective first or second channel 122, 124 and to allow the air flow to pass the other of the first or second channel 122, 124.

The switching member 140 is elongated with a length at least as long as the length of the air outlet 110. The switching member 140 is at least as long as the length of the first and second air outlets 126, 128. The switching member 140 extends substantially parallel to the longitudinal axis 103 of the body 102.

The switching member 140 includes an arcuate or curved surface 146 for diverting the air flow toward the first or second air outlets 126, 128. The switching member 140 thus forms a concave surface for guiding the airflow from the radial direction of the body 102 towards the tangential direction of the curved surface 104.

Accessory 100 includes a handle 142 on switching member 140. The handle 142 is movable by a user to move the switching member 140 between the first switching position and the second switching position. The switching member 140 and the handle 142 form a single body. It should be appreciated that any other suitable user interface may be employed to move the switching member 140 between the first and second switching positions.

The switching member 140 is movable about a pivot 144 between the first and second switching positions such that the switching member 140 rotates about the pivot 144. The switching member 140 is rotated about the pivot 144 through an angle in the range of 18 degrees to 30 degrees (e.g., between 22 degrees and 26 degrees) to move between the first and second switching positions. The handle 142 is located on an outer portion of the switch member 142 that is farther from the longitudinal axis 103 of the body 102 than the pivot 144. Thus, the user can more easily access the handle. It should be appreciated that in other embodiments, the switching member 140 may be movable between the first and second switching positions in any suitable manner, such as, for example, the switching member 140 sliding relative to the air outlet 110.

The accessory 100 includes a retaining mechanism 150. The retaining mechanism is used to retain switching member 140 in one of the first and second switching positions in the absence of a force applied to handle 142 of switching member 140 by a user of hair care appliance 10. The retaining mechanism 150 is arranged to retain the switch member 140 in another switch position when a user of the hair care appliance 10 applies a force to the handle 142 of the switch member 140. Referring to fig. 7 and 8, the retaining mechanism 150 retains the switching member 140 in the first switching position shown in fig. 7 until a user applies a force (represented by arrow 152) to the handle 142. Upon application of force 152, switching member 140 is released from the first switching position and moves to the second switching position shown in fig. 8, where switching member 140 is held by holding mechanism 150 until a user applies force to handle 142.

The holding mechanism 150 includes a first pair of magnetic elements 154 configured to hold the switching member 140 in a first switching position and a second pair of magnetic elements 156 configured to hold the switching member 140 in a second switching position. The first magnetic element of each pair of magnetic elements 154, 156 is located inside the respective planar surface 130 and the second magnetic element of each pair of magnetic elements 154, 156 is located opposite the first magnetic element of the respective pair of magnetic elements 154, 156 on the switching member 140. In this example, a first magnetic element of each pair of magnetic elements 154, 156 comprises a metal sheet, and a second magnetic element of each pair of magnetic elements 154, 156 comprises a magnet arranged to attract the metal sheet. It should be appreciated that the retaining mechanism may include other forms of retainers, such as releasable mechanical fasteners and biasing elements.

The second magnetic element of each pair of magnetic elements 154, 156 is located inside the switching mechanism 140 closer to the longitudinal axis 103 of the body 102 than the pivot. This may prevent a user from being able to access the magnetic element and thus touch the magnetic element.

The minimum force 152 required to overcome the retaining mechanism 150 to move the switching member 140 between the first switching position and the second switching position is in the range of up to 5N, more particularly 0.3N to 3N.

The accessory 100 includes a rib 148, in this embodiment, the rib 148 is connected to the switching member 140. The ribs 148 are positioned such that they interact with the airflow exiting the air outlet 110 to align the airflow exiting the air outlet 110 to provide a more laminar airflow at the first and second air outlets 126, 128. The ribs 148 are positioned relative to the first and second channels 122, 124 to smooth the airflow in the first and second channels 122, 124 to provide a more laminar airflow at the first and second air outlets 126, 128 before the airflow flows over the curved surfaces.

The ribs 148 interact with the airflow exiting the air outlet 110 to provide a more aligned, smoother, more laminar airflow at the first air outlet 126, which in turn provides a more cohesive airflow across the curved surface 104. As the airflow turns, the airflow typically separates, thereby becoming more turbulent and noisy. The ribs 148 have upper and lower surfaces along which the airflow flows as it passes through the first and second channels 122, 124, which helps reduce flow separation and thus turbulence and noise, as compared to the attachment 100 without the ribs 148.

By being connected to the switching member 140, the rib 148 is movable relative to the air outlet 110. Accordingly, rib 148 may be moved relative to air outlet 110 by a user applying a force to handle 142 to move switching member 140 between the first and second switching positions, thereby moving the rib.

The ribs 148 are elongated with a length at least as long as the length of the air outlet 110 such that the ribs 148 interact with the air over substantially the entire length of the air outlet 110.

The ribs 148 include substantially smooth edges to reduce turbulence in the first and second channels 122, 124.

The ribs 148 are maintained spaced apart from the curved surface 146 of the switching member 140 by connecting members 149 (best shown in fig. 9) to allow airflow to flow past either side of the ribs 148. When the body 102 is in the first position, the air flow exiting the air outlet 110 is bisected by the ribs 148 and passes between adjacent connecting members 149.

The connecting members 149 are spaced apart along the length of the ribs 148. The connecting member 149 rigidly connects the rib 148 to the switching member 140 such that the rib 148 is not movable relative to the switching member 140. It should be appreciated that in other embodiments, the rib 148 may move relative to the switching member 140.

The rib 148 and the connecting member 149 form a single body.

The hair care appliance 10 includes an alarm module 36. The alarm module is arranged to provide an alarm to the user that the body 102 is in the first position or the second position and/or to provide an alarm to the user that the switching member 140 is in the first switching position or the second switching position. Alert module 36 includes one or more of a tactile feedback module, audible indicia, or visual indicia. In this embodiment, the alarm module 36 is shown in the handle unit 12, but it should be understood that in other embodiments, the alarm module 36 may be included in the accessory 100. Hair care appliance 10 may include separate alarm modules 36 for body 102 and switching member 140.

In use, the accessory 100 is attached to the handle unit 12. The airflow generator 16 generates an airflow from the air inlet 22 of the handle unit 12 to the air outlet 24 of the handle unit 12 such that the airflow flows from the air outlet 24 of the handle unit to the air inlet 108 of the accessory 100. The airflow passes from the air inlet 108 of the accessory through the body 102 and is diverted by a plurality of internal baffles 114 toward the air outlet 110 of the accessory 100. If the body 102 is in the first position, the air flow exits the body 102 via the air outlet 110 and passes over the curved surface 102, or if the body 102 is in the second position, the air flow flows in a radial direction of the body 102.

In use, the body 102 is held rigidly in place relative to the handle unit 12 and the guide 120 is rotatable relative to the handle unit 12 to move the body 102 between the first and second positions. It should be appreciated that in other embodiments, the guide 120 may be rigidly positioned relative to the handle unit 12 and the body 102 may be rotated between the first and second positions relative to the handle 12 and the guide 120.

In use, the switch member 140 is movable between first and second switch positions when a user applies a force to the handle 142. The force may be applied by the user's hand or by the force generated when the handle 142 is in contact with the user's hair and/or head. The handle 142 is located at the rear edge of the planar surface 130 and thus may contact the hair and/or head of a user in use, as described in more detail below, to move the switching member between the first and second switching positions.

In use, the attachment 100 may be moved along the length of a bundle of hair, for example in a direction from the root to the tip of the bundle of hair. A respective one of the planar surfaces 130 is positioned relative to the curved surface 104 such that the planar surface 130 contacts hair extending rearwardly from the air outlet 110 while hair downstream of the air outlet 110 contacts the curved surface 104. As previously mentioned, the planar surface 130 is substantially smooth and uninterrupted in form, without protrusions, recesses or holes formed therein. As hair care appliance 10 moves along the length of a bundle of hair in use, flat surface 130 passes through hair that has been softened by interaction with curved surface 104. In view of the smooth and uninterrupted nature of the flat surface 130, the flat surface 130 does not disrupt hair that has been compliant, resulting in a better finish than a corresponding hair care appliance having bristles and/or additional air outlets located behind the air outlet 110, for example.

Although embodiments having releasable attachments are described herein, embodiments are also contemplated wherein the hair care appliance does not include a handle unit and attachments, but rather includes a single piece unit, for example in the form of the previously described combination handle unit and attachments.

Claims (19)

1. An attachment for a hair care appliance, the attachment comprising an air inlet, an air outlet, a curved surface adjacent to and downstream of the air outlet, and a rib positioned such that the rib interacts with an air flow exiting the air outlet to align the air flow exiting the air outlet.

2. The accessory of claim 1, wherein the air flow exiting the air outlet generates a first force to draw hair toward the curved surface and a second force to push hair away from the curved surface, and the ribs are positioned to align the air flow across the curved surface.

3. An accessory according to claim 1 or 2, wherein the rib is movable relative to the air outlet.

4. An accessory according to any one of the preceding claims wherein the ribs are positioned to divide the air flow exiting the air outlet in two to align the air flow.

5. An accessory according to any one of the preceding claims, comprising a connecting member for holding the rib in place in the air flow leaving the air outlet.

6. The accessory of claim 5, wherein the connecting member is rigidly connected to the rib.

7. The accessory of claim 5 or 6, wherein the connecting members are equally spaced along the length of the rib.

8. An accessory according to any preceding claim, comprising a channel for diverting air flow exiting the air outlet towards the curved surface, wherein the ribs are positioned to smooth air flow in the channel.

9. An accessory according to any one of the preceding claims, comprising a first channel for guiding an air flow through the curved surface in a first direction and a second channel for guiding an air flow through the curved surface in a second, opposite direction, wherein the rib is movable relative to the air outlet to smooth the air flow in the first and second channels.

10. The accessory of claim 9, wherein the first channel is arranged to direct airflow through a first region of the curved surface and the second channel is arranged to direct airflow through a second, different region of the curved surface, the first and second regions of the curved surface being adjacent to and downstream of opposite sides of the air outlet.

11. An accessory according to any one of claims 8 to 10, comprising a switching member for switching air flow between the first and second channels, the switching member being movable from a first switching position in which air flow passes through the first channel in a first direction through a first region of the curved surface and does not pass through the second channel to a second switching position in which air flow passes through the curved surface in an opposite second direction through a second air outlet and does not pass through the first channel.

12. The accessory of claim 11, wherein the rib is connected to the switching member such that a position of the rib relative to the first and second channels differs depending on whether the switching member is in the first or second switching position.

13. The accessory according to claim 11 or 12, comprising a retaining mechanism for retaining the switching member in one of the first and second switching positions in the absence of a force being applied to the switching member by a user of the hair care appliance.

14. The accessory of claim 11, wherein the retaining mechanism includes a first pair of magnets configured to retain the switching member in the first switching position and a second pair of magnets configured to retain the switching member in the second switching position.

15. The accessory of any one of the preceding claims, comprising a body defining the air outlet and the curved surface, wherein the body is rotatable relative to the rib between a first position in which air flow exiting the air outlet interacts with the rib and a second position in which air flow exiting the air outlet does not interact with the rib.

16. The accessory of claim 15, wherein the body is generally cylindrical and configured to direct an airflow away from the air outlet in a radial direction, and wherein the ribs are to align with an airflow diverted from the radial direction toward the curved surface when the body is in the first position.

17. The accessory according to any one of claims 3 to 16, comprising a user interface operable by a user to move the rib relative to the air outlet.

18. A hair care appliance comprising an air inlet, an air outlet, an air flow generator for generating an air flow from the air inlet to the air outlet, a curved surface adjacent to and downstream of the air outlet, and a rib positioned such that the rib interacts with the air flow exiting the air outlet to align the air flow exiting the air outlet.

19. The hair care appliance of claim 18, comprising a handle unit within which the airflow generator is housed and an accessory removably attached to the handle unit, the accessory comprising the air outlet, the curved surface and the rib.