WO2022269230A1

WO2022269230A1 - A haircare appliance

Info

Publication number: WO2022269230A1
Application number: PCT/GB2022/051419
Authority: WO
Inventors: Yuchen Yang; Ayrton PEEL
Original assignee: Dyson Technology Limited
Priority date: 2021-06-22
Filing date: 2022-06-07
Publication date: 2022-12-29
Also published as: US20240358133A1; CN219088594U; CN115530508A; GB2608123A; GB202108923D0; GB2608123B

Abstract

A attachment for a haircare appliance, the attachment having a main body comprising an air inlet and an air outlet. The attachment has a guide for directing airflow from the air outlet across a curved surface of the main body, such that airflow directed by the guide generates a first force to attract hair toward the curved surface, and a second force to push hair away from the curved surface. The main body is rotatable relative to the guide between a first position in which airflow exiting the air outlet is directed by the guide and a second position, in which airflow exiting the air outlet is not directed by the guide.

Description

A HAIRCARE APPLIANCE

Field of the Invention

The present invention relates to a haircare appliance, and an attachment for a haircare appliance.

Background of the Invention

Haircare appliances are typically used to dry and style hair. Where haircare appliances are used to style hair to create a smooth appearance, the presence of shorter or broken hairs, sometimes referred to as flyaways, may impact on the desired smooth appearance.

Summary of the Invention

According to a first aspect of the present invention there is provided an attachment for a haircare appliance, the attachment comprising a main body comprising an air inlet and an air outlet, and a guide for directing airflow from the air outlet across a curved surface of the main body, such that airflow directed by the guide generates a first force to attract hair toward the curved surface, and a second force to push hair away from the curved surface. The main body is rotatable relative to the guide between a first position in which airflow exiting the air outlet is directed by the guide and a second position, in which airflow exiting the air outlet is not directed by the guide.

The attachment according to the first aspect of the present invention may be advantageous as the inventors of the present application have determined that directing airflow across the curved surface of the main body may generate a negative pressure region adjacent to the curved surface which attracts long hairs toward the curved surface, with the airflow interaction with hair also pushing shorter hairs away from the curved surface. This may result in shorter hairs being pushed through the longer hairs, for example through the longer hairs toward the side of hair facing a user’s head, such that a smooth finish is provided.

The attachment may be configured such that airflow exiting the air outlet generates a first force to attract hair toward the curved surface, and a second force to push hair away from the curved surface. This may achieve a smooth finish by attracting long hairs toward the curved surface whilst pushing short hairs away from the curved surface, through the long hairs, in the manner described above. The attachment may be configured such that a negative pressure region is generated in the vicinity of the curved surface in use.

The attachment according to the first aspect of the present invention may be advantageous as the attachment can be used in two different modes depending on the position of the main body and thus the form of airflow exiting the air outlet. For example, the attachment may be used for hair styling when the main body is in the first position and hair drying when the main body is in the second position.

The curved surface may comprise a Coanda surface, for example a convex surface along which airflow is attached as a result of the Coanda effect in use.

The curved surface may be substantially smooth and uninterrupted in form. This may enable hair to wrap around the curved surface in use.

The curved surface may comprise a radius of curvature in the region of 10mm to 60mm. The applicant has found that such a radius of curvature may be particularly effective in generating an airflow along the curved surface that results in a first force to attract hair toward the curved surface, and a second force to push hair away from the curved surface. The curved surface may comprise a substantially constant radius of curvature.

The airflow generator may be configured to generate airflow at a flow rate in the region of 8L/s to 18L/s. The applicant has found that such an airflow rate may be particularly effective in generating an airflow along the curved surface that results in a first force that is sufficient to attract relatively long hair toward the first surface whilst also generating a second force to push relatively short hair away from the curved surface.

The main body may be rotatable between the first position and the second position about a longitudinal axis of the main body. The longitudinal axis of the main body may be a central axis of the main body extending from a proximal to a distal end of the main body. This may aid with weight distribution within the attachment as the main body is rotated between the first and second positions, increasing the ease of handling by a user.

The first and second positions may be 180 degrees apart from one another. This may aid weight distribution within the attachment as the main body is rotated between the first and second positions, increasing the ease of handling by a user. This may also enable a user to easily ascertain a mode that the attachment is operating.

The attachment may comprise a spring plunger connected to the main body for locating the main body in the first and second positions. This may provide feedback to a user to confirm that the main body is in the first or second position. The attachment may further comprise a pair of ramps arranged to engage with the spring plunger for limiting a range of movement of the spring plunger.

The air outlet may comprise a longitudinal slot defined in an outer surface of the main body. That is, the air outlet may have a length extending parallel to a longitudinal axis of the main body, and a width extending normal to the longitudinal axis, the length being greater than the width. This may allow a greater area of hair to be contacted by the airflow exiting the air outlet and thus be styled by the attachment.

The air outlet may comprise a fixed air outlet, for example an air outlet of fixed cross- sectional area, length and/or width. This may ensure that airflow characteristics of the attachment are constant for a given flow rate of airflow generated by the airflow generator, thereby ensuring that an airflow is generated along the curved surface that results in a first force to attract hair toward the curved surface, and a second force to push hair away from the curved surface. This may ensure a constant airflow along a length of the air outlet, allowing more aligned hair smoothing by the attachment. This may also provide a simpler attachment with fewer moving parts, and hence a reduced risk of failure, compared to a attachment with a variable air outlet.

The main body may be generally cylindrical. This may help to aid a smooth rotation of the main body between the first and second positions. The main body may be configured to direct airflow exiting the air outlet in a radial direction. That is, the main body is configured such that airflow exits the air outlet in a direction normal to the outer surface of the main body in which the air outlet is defined. This may aid in ease of use of the attachment when drying hair with the main body in the second position.

The attachment may comprise a user interface operable by a user to rotate the main body relative to the guide between the first position and the second position. The user interface may, for example, comprise one or more of a handle, high friction gripping surface, push button, toggle or touch screen. This may aid in simplifying a process for a user to rotate the main body between the first and second positions. The user interface may comprise a handle protruding from a distal end of the main body. The handle may be rigidly attached to the main body and rotatable by a user to rotate the main body relative to the guide between the first position and the second position. The handle may provide an easily accessibly and simple-to-use user interface operable by a user. Positioning the handle at the distal end of the main body ensures that a user’s hand does not cross airflow, which may be heated, exiting the air outlet to rotate the main body.

The guide may comprise an inner casing arranged to contact the curved surface of the main body and comprising an aperture corresponding to the air outlet. When the main body is in the first position the aperture and the air outlet are aligned to permit airflow through the air outlet and the aperture. This may help to reduce air loss as airflow exits the main body and is directed by the guide. The inner casing may comprise raised ridges positioned on either side of the aperture and thus on opposite sides of the air outlet when the main body is in the first position. The raised ridges may extend along a length of the air outlet. The raised ridges may provide a smoother guiding surface for turning airflow from the air outlet toward the curved surface. This may help to reduce separation of the airflow to maintain a more laminar airflow.

The guide may comprise a first channel arranged to direct airflow in a first direction around the curved surface of the main body, and a second channel arranged to direct airflow in a second, opposite direction around the curved surface of the main body. This may enable airflow in a direction parallel to a direction of a user’s hair, away from the hair roots, no matter which side of the head is being treated by the attachment, thus providing better hair smoothing performance. This in turn may enable a user to more comfortably use the attachment in different orientations to treat hair on different sides of the head.

The first and second channels may define respective first and second air outlets downstream of the air outlet of the main body. This enables airflow from a single air outlet, as defined in the main body, to flow in opposite directions around the curved surface depending on whether the air flow passes through the first or second channel.

The first and second air outlets may each comprise a length in the region of 50mm to 150mm, for example in the range of 75mm to 85mm. The first and second air outlets may comprise a width in the region of 2mm to 5mm, for example in the range of 3.0mm to 4.5mm. The first and second air outlets may be generally rectangular in form, for example such that airflow leaving the main air outlet has a generally laminar form.

The first and second air outlets may comprise an open cross-sectional area in the region of 140mm² to 450mm², for example in the region of 280mm² to 350mm². The applicant has found that such an open cross-sectional area may be particularly effective in generating an airflow along the curved surface that results in a first force to attract hair toward the curved surface, and a second force to push hair away from the curved surface. The first and second air outlets may define rectangular slots, which may provide a more laminar airflow across the curved surface. The rectangular slots may extend substantially parallel to a longitudinal axis of the main body. This may allow a greater area of hair to be contacted by the airflow across the curved surface and thus styled by the attachment.

The first and second air outlets may each have a smaller open cross-sectional area than the air outlet. That is, each of the first and second air outlets defined by the respective first and second channels may have a smaller open cross-sectional area than the air outlet of the main body. This may allow for a greater air velocity through the first or second channel compared to the air outlet for the same air flow rate, which may be advantageous for hair styling when the main body is in the first position. Channelling airflow from a larger open cross-sectional area at the air outlet to a smaller open cross-sectional area at the first and second air outlets may generate a converging airflow at the first and second air outlets, which may reduce noise and improve hair alignment performance.

The attachment may be configured such that airflow at the first and second air outlets comprises a velocity in the region of 30m/s to 65m/s, for example in the range of 45m/s to 55m/s. The applicant has found that such a velocity may be particularly effective in generating an airflow along the curved surface that results in a first force that is sufficient to attract relatively long hair toward the first surface whilst also generating a second force to push relatively short hair away from the curved surface. The first and second air outlets may be shaped and dimensioned such that airflow at the first and second air outlets comprises a velocity in the region of 30m/s to 65m/s. The airflow generator may be configured to generate an airflow at a flow rate such that airflow at the main air outlet comprises a velocity in the region of 30m/s to 65m/s.

A ratio of flow rate of airflow generated by the airflow generator to an open cross- sectional area of the first and second air outlets may be in the region of 0.01 to 0.10. The applicant has found that such a ratio may be particularly effective in generating an airflow along the curved surface that results in a first force to attract hair toward the curved surface, and a second force to push hair away from the curved surface.

A ratio of a radius of curvature of the curved surface to a velocity of airflow at first and second air outlets may be in the region of 0.33 to 2.00, for example in the range of 0.5 to 1.5. The applicant has found that such a ratio may be particularly effective in generating an airflow along the curved surface that results in a first force to attract hair toward the curved surface, and a second force to push hair away from the curved surface.

A ratio of a velocity of airflow at the first and second air outlets to a flow rate of airflow generated by the airflow generator may in the region of 2.14 to 5.63, for example in the range of 2.6 to 3.6. The applicant has found that such a ratio may be particularly effective in generating an airflow along the curved surface that results in a first force to attract hair toward the curved surface, and a second force to push hair away from the curved surface.

The curved surface may comprise a continuous surface extending between the first and second channels when the main body is in the first position. Such a continuous surface may facilitate attraction of hair to the curved surface when the attachment is used in multiple orientations. The curved surface may comprise a continuous surface extending from a first side of the air outlet of the main body, around the main body, to a second side of the air outlet of the main body.

The guide may comprise a first flat surface adjacent to and extending rearwardly from the first channel, and a second flat surface adjacent to and extending rearwardly from the second channel. Where a non-flat surface extends rearwardly from the first and second channels, the smooth finish can be disturbed as the attachment is moved relative to the hair in use, as may typically be the case during styling operations. Where a rough surface, for example a surface comprising projections such as bristles or the like, is provided extending rearwardly from the channel, such a rough surface may interrupt hair that has already been smoothed by airflow from the channel as the attachment is moved relative to the hair in use. By providing the first and second flat surfaces adjacent to and extending rearwardly from the respective first and second channels, a smooth hair finish may be created and maintained as the attachment is moved relative to hair by a user in use.

The first and second flat surfaces may also act as a guide surface to ensure that the attachment is located correctly relative to a head of a user such that airflow exiting the channel is able to provide the functionality described above.

The first and second flat surfaces may be substantially smooth and uninterrupted in form. The first and second flat surfaces may comprise a generally planar surface. This may aid with retention of a smooth hair surface as the attachment is moved relative to hair in use and may ensure that hair extending rearwardly from the channel is supported by the surface.

The attachment may be configured such that the first or second flat surface contacts hair extending rearwardly from the respective first or second channel as the attachment is moved relative to hair in use, for example as the attachment is moved linearly in a direction along the hair, from roots of the hair to tips of the hair in use.

The first and second flat surfaces may comprise a height in the region of 5mm to 20mm.

The first and second flat surfaces may be obliquely angled relative to a plane of the respective first or second channel. This may ensure that hair extending rearwardly from the respective first or second channel contacts the flat surface whilst hair downstream of the respective first or second channel is attracted toward the curved surface in use. The first and second flat surfaces may be obliquely angled relative to a plane tangential to the curved surface at a point of the curved surface immediately adjacent to the respective first or second channel.

The attachment may comprise a pair of guide walls for directing airflow along the curved surface of the main body, the pair of guide walls upstanding from the curved surface of the main body. By providing a pair of guide walls extending outwardly from the curved surface ambient air may be inhibited from impacting on a region of negative pressure generated by airflow flowing along the curved surface in use, and may result in increased attraction of hair toward the curved surface compared to, for example, a similar arrangement that does not utilise guide walls.

Each of the guide walls may be curved in form, for example with a curvature following a curvature of the curved surface. Guide walls of the pair of guide walls may oppose one another, for example such that a channel is defined therebetween, with the curved surface forming a bed of the channel. The pair of guide walls may be spaced apart along the curved surface from one another, for example spaced apart at opposing edges of the curved surface. A spacing between the guide walls may correspond substantially to a length of the first and second channels. The curved surface may be substantially smooth and uninterrupted between the pair of guide walls. This may enable hair to wrap around the curved surface between the pair of guide walls in use.

The guide walls may project outwardly from the curved surface, for example with the guide walls and the guide integrally formed as a single component. The pair of guide walls may comprise a height substantially equal to a height of the first and second channels. This may ensure that a negative pressure region is maintained along substantially the entire height of a jet of air that exits the respective first or second channel in use.

The pair of guide walls may comprise a radius of curvature greater than a radius of curvature of the curved surface. For example, the pair of guide walls may comprise a radius of curvature greater than a radius of curvature of the curved surface in a region adjacent to the first and second channels. This may ensure that the pair of guide walls provide their functionality in the region adjacent to the first and second channels in use.

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

The pair of guide walls may comprise a height that varies along a length of the guide wall. The inventors of the present application have found that the guide walls provide most impact in certain regions of the curved surface, for example in a region adjacent to the first and second channels. The pair of guide walls may comprise a height that decreases in a direction away from the respective first or second channel. By reducing a height of the guide walls in a direction away from the first and second channels, less material may be required to form the guide walls than, for example, guide walls of a constant height. The pair of guide walls may comprise a height that gradually decreases in a direction away from the respective first or second channel, for example such that there are no step- changes in height. Guide walls of the pair of guide walls may each comprise the same height, and may be substantially symmetrical about an axis bisecting a space between the guide walls.

The pair of guide walls may comprise a constant height. This may provide certainty that a negative pressure region generated adjacent to the curved surface will not be impacted along the length of the curved surface.

The attachment may comprise a switching member for switching airflow between the first and second channels, the switching member movable from a first switch position in which airflow passes through the first channel across the curved surface in a first direction and does not pass through the second channel, to a second switch position in which airflow passes through the second air outlet across the curved surface in a second, opposite direction and does not pass through the first channel. This may ensure that airflow only passes over the curved surface in one direction in use. This may prevent direction of airflow away from the head of a user in use, and hence may result is less wasted airflow and more efficient styling. This may also ensure that there is a reduced amount of stray airflow from an air outlet not used as part of the styling process that can impact the styling process in use. The switching member may be comprised in the guide such that the main body rotates relative to the switching member between the first and second positions. For example, the switching member may be located within the guide. This may help to enable the attachment to operate in different modes due to the different relative positions of the air outlet and the switching member when the main body is in the first or second position.

The switching member may be elongate, having a length at least as long as a length of the air outlet. This may reduce air loss as air flows through the air outlet and into the first or second channel, thus increasing the air flow rate over the curved surface.

The switching member may extend substantially parallel to the longitudinal axis of the main body. This enables smooth rotation of the main body relative to the switching member and alignment of the switching member with the air outlet with the main body is in the first position.

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

The switching member may comprise a single body, for example a single monolithic component. This may provide a simpler arrangement than, for example, a corresponding arrangement where the switching member comprises multiple bodies, which may reduce component count and cost, and may reduce a risk of failure in use.

The attachment may comprise a retention mechanism for retaining the switching member in one of the first and second switch positions in the absence of an applied force to the switching member by a user of the attachment. This may help a user to use the attachment in a variety of orientations without the switching member moving between the first and second switch positions. The retention mechanism may be arranged to retain the switching member in the other of the first and second switch positions upon application of an applied force to the switching member by a user of the attachment. This may provide assurance to the user that the switching member is positioned correctly. This may also ensure a correct direction of airflow across the curved surface to provide better styling performance.

The retention mechanism may comprise a first pair of magnetic elements configured to retain the switching member in the first switch position and a second pair of magnetic elements configured to retain the switching member in the second switch position. Each magnetic element in a pair of magnetic elements is magnetically attracted to the other magnetic element of the pair. This may provide a simple mechanism for retaining the switching member in the desired switch position and for a user to apply a force against the pair of magnetic elements to move the switching member of the other switch position.

The retention mechanism may comprise a releasable mechanical fastener for retaining the switching member in the first and second switch positions. For example, the releasable mechanical fastener may comprise a hook, detent or press stud. This may provide a simple way of retaining the switching member in position until application of a force by a user, which may reduce manufacture and assembly complexity.

The retention mechanism may comprise a biasing element for biasing the switching member to the first and second switch positions. For example, the retention mechanism may comprise a bi-stable spring that is stable when the switching member in the first and second switch positions. The biasing element may help to ensure the switching member properly reaches the first and second switch positions to ensure proper switching of airflow between the first and second air outlets. The biasing element may also increase the force required to move the switching member between the first and second switch positions which may help to prevent inadvertent movement of the switching member. An applied force for moving the switching member between the first and second switch positions may be a contact force applied to the switching member. This may provide the advantage that a user can clearly identify that the switching member has been moved because the user has applied a force directly to the switching member.

A minimum applied force required to overcome the retention mechanism to move the switching member between the first switch position and the second switch position may be in the region up to 5N. A minimum applied force required to overcome the retention mechanism to move the switching member between the first switch position and the second switch position may be in the region of 0.3N to 3N. The inventors of the present application have found that such forces may be suitable for a user to apply to the switching member with an intent to move the switching member and to prevent inadvertent movement of the switching member during normal use of the attachment.

The attachment may comprise a rib positioned such that the rib interacts with airflow in the first or second channel to align airflow. The rib may bisect airflow in the first or second channel to align airflow. The rib may reduce noise created by airflow generated within the attachment by reducing flow separation in the first or second channel. The rib may provide a more laminar airflow by smoothing airflow as it turns from a radial direction at the air outlet towards a tangential direction in the first or second channel.

The rib may be connected to the switching member such that a position of the rib relative to the first and second channels is different dependent on whether the switching member is in the first switch position or the second switch position. This may help the rib to provide optimised airflow alignment dependent on the position of the switching member to that airflow can be smoothed by the rib regardless of which direction around the curved surface it is directed.

The rib may be rigidly connected to the switching member. This may aid in manufacturing simplicity and in ensuring a correct position of the rib in the airflow. The attachment may comprise an alert module configured to alert a user that the main body is in the first position and/or the second position. This may enable a user to, know which mode the attachment is operating in. For example, the alert module may provide a first indicium to indicate when the main body reaches the first position and a second, different indicium when the main body reaches the second position. The alert module may comprise at least one of a haptic feedback module, a visual indicium, and an aural indicium. This may ensure that an alert is provided to a user irrespective of whether the attachment is visible to the user.

The longitudinal axis of main body may be substantially coincidental with a central axis of the airflow generator, for example substantially coincidental with a central axis of a housing within which the airflow generator is disposed.

The attachment may comprise an internal baffle for turning airflow from the airflow generator toward the air outlet, for example turning airflow through around 90 degrees toward the air outlet. This may enable a main portion of the attachment housing the airflow generator to extend orthogonally relative to the air outlet, which may provide greater flexibility in design, and better ergonomics, than, for example a attachment where the air outlet is aligned with a main portion of the attachment housing the airflow generator.

The internal baffle may be comprised in the main body and configured to rotate with the main body between the first and second positions. This may ensure that airflow is always directed toward the air outlet, regardless of the position of the main body relative to the guide.

The attachment may comprise a secondary housing extending at least partially between the main body and the guide, the secondary housing comprising a second air outlet wherein the second air outlet aligns with the air outlet from the main body when the main body is in the second position. The secondary housing and the guide may be C-shaped. The secondary housing may extend about the main body on a first side. The guide may extend about the main body and a part of the secondary housing on a second side.

According to a second aspect of the present invention there is provided a haircare appliance comprising a main body comprising an air inlet and an air outlet, an airflow generator for generating an airflow from the air inlet to the air outlet, and a guide for directing airflow from the air outlet across a curved surface of the main body, such that airflow directed by the guide generates a first force to attract hair toward the curved surface, and a second force to push hair away from the curved surface, wherein the main body is rotatable relative to the guide between a first position in which airflow exiting the air outlet is directed by the guide and a second position, in which airflow exiting the air outlet is not directed by the guide.

The haircare appliance may comprise a heater for heating the airflow. This may provide increased styling flexibility, and may, for example, enable the airflow to provide a drying function. The heater may be configured to operate at a particular temperature dependent on whether the main body is in the first position or the second position.

The haircare appliance may comprise a handle unit within which the airflow generator is housed, and an attachment according to the first aspect of the present invention, the attachment releasably attachable to the handle unit. Providing a removable attachment may allow the functionality of the attachment described herein to be selectively provided by a user.

When the attachment is attached to the handle unit, the main body may be rigidly held relative to the handle unit and the guide may be rotatable relative to the handle. This may enable a user to switch the haircare appliance between operative modes without needing to change their grip on the haircare appliance. Optional features of aspects of the present invention may be equally applied to other aspects of the present invention, where appropriate.

Figure 1 is a schematic view illustrating a haircare appliance according to the present invention;

Figure 2 is a schematic cross-sectional view through a handle unit of the haircare appliance of Figure 1;

Figure 3 is a schematic perspective view of an embodiment of an attachment for the haircare appliance of Figure 1, illustrating the attachment in a second mode;

Figure 4 is a schematic cross-sectional view of the attachment of Figure 3, illustrating the attachment in the second mode;

Figure 5 is a schematic perspective view of the attachment of Figure 3, illustrating the attachment in a first mode;

Figure 6 is a schematic view illustrating forces created by airflow through the attachment of Figure 3 in use in the first mode;

Figure 7 is a schematic top view of the attachment of Figure 3, illustrating the attachment in the first mode and a first switch position;

Figure 8 is a schematic top view of the attachment of Figure 3, illustrating the attachment in the first mode and a second switch position;

Figure 9 is a schematic exploded view of the attachment of Figure 3; Figure 10a is a schematic cross-sectional view of a further attachment, illustrating the attachment in the second mode;

Figure 10b is a schematic perspective view of an embodiment of the attachment of Figure 10a;

Figure 11a is a schematic perspective view of an embodiment of an attachment;

Figure lib is a schematic cross-sectional view of the attachment of Figure 11a, illustrating the attachment in the second mode;

Figure 12a is a schematic perspective view of another embodiment of an attachment;

Figure 12b is a schematic cross-sectional view of the attachment of Figure 12a, illustrating the attachment in the first mode; and

Figure 12c is an enlarged partial view of the schematic cross-sectional view of the attachment of Figure 12a.

A haircare appliance according to the present invention, generally designated 10, is shown schematically in Figure 1.

The haircare appliance 10 comprises a handle unit 12, and an attachment 100 removably attachable to the handle unit 12.

The handle unit 12 comprises a housing 14, an airflow generator 16, a heater 18, and a control unit 20, as can be seen schematically in Figure 2.

The housing 14 is tubular in shape, and comprises an air inlet 22 through which an airflow is drawn into the housing 14 by the airflow generator 16, and an air outlet 24 through which the airflow is discharged from the housing 14. The airflow generator 16 is housed within the housing 14, and comprises an impeller 26 driven by an electric motor 28. The airflow generator is configured to generate airflow at a flow rate in the region of 8 to 18 L/S, for example in the region of 10 to 16L/s. An appropriate airflow generator is the Dyson V9 Digital Motor, produced by Dyson Technology Limited. The heater 18 is also housed within the housing 14, and comprises heating elements 30 to optionally heat the airflow.

The control unit 20 comprises electronic circuitry for a user interface 32 and a control module 34. The user interface 32 is provided on an outer surface of the housing 14, and is used to power on and off the haircare appliance 10, to select a flow rate (for example high, medium and low), and to select an airflow temperature (for example hot, medium or cold). In the example of Figure 1, the user interface comprises a plurality of sliding switches, but other forms of user interface 32, for example buttons, dials or touchscreens, are also envisaged.

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 inputs from the user interface 32, the control module 34 may control the power or the speed of the airflow generator 16 in order to adjust the airflow rate of the airflow, and the power of the heater 18 in order to adjust the temperature of the airflow.

The attachment 100 is shown schematically in Figures 3-5 and 7-9.

The attachment 100 comprises a main body 102 comprising an air inlet 108, an air outlet 110, a curved surface 104, and a plurality of internal baffles 114. The attachment comprises a guide 120, which when aligned with the air outlet 110 of the main body 108 directs airflow from the air outlet 110 across the curved surface 104 of the main body, such that airflow directed by the guide 120 generates a first force to attract hair toward the curved surface 104, and a second force to push hair away from the curved surface 104. The air inlet 108 comprises a generally circular aperture formed in the main body 102, and the air inlet 108 is configured to receive airflow from the air outlet 24 of the handle unit 12 when the attachment 100 is attached to the handle unit 12 in use. A periphery of the air inlet 108 comprises attaching features for releasably attaching the attachment 100 to the handle unit 12. The attaching features may take many forms, are not pertinent to the present invention, and so will not be described for the sake of brevity.

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

A cross-sectional view of the curved surface 104 is illustrated schematically in Figure 4. The main body 102 is generally cylindrical and the curved surface 104 is the circumferential surface of the main body 102. Thus, the curved surface 104 is located adjacent to, and downstream of, the air outlet 110. It will be appreciated that in other embodiments, the main body 102 may not be generally cylindrical and the curved surface 104 may extend only partially around the main body 102.

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

The curved surface 104 is substantially smooth and uninterrupted in form, such that no projections, recesses or apertures are formed thereon. This may enhance the functionality of the attachment 100 which will be described hereafter. The curved surface 104 has a radius of curvature in the region of 10mm to 60mm, for example in the region of 15mm to 40mm. In a presently preferred embodiment, the curved surface 104 has a radius of curvature in the region of 20mm. The inventors of the present application have found that such a geometry of the curved surface 104 may provide advantageous effects, as will be described hereafter.

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 turn airflow in a direction from the air inlet 108 to a direction toward the air outlet 110, such that airflow is turned through substantially 90 degrees from the air inlet 108 to the air outlet 110. This may enable the handle unit 12 to extend orthogonally relative to the air outlet 110, which may provide greater flexibility in design, and better ergonomics, than, for example a haircare appliance where the air outlet is aligned with a handle unit of the haircare appliance.

The main body 102 is rotatable about its central longitudinal axis 103 relative to the guide 120, between a first position in which airflow exiting the air outlet 110 is directed by the guide 120, as shown in Figures 5, 7 and 8, and a second position in which airflow exiting the air outlet 110 is not directed by the guide 120, as shown in Figures 3 and 4. The direction of airflow out of the air outlet 110 is denoted by arrow 101 in Figures 4, 7 and 8, which show different operating configurations of the attachment 100.

The position of the main body 102 relative to the guide 120 determines an operating mode of the haircare appliance 100. In this embodiment, when the main body 102 is in the first position, as shown in Figures 5, 7 and 8, the haircare appliance 100 is configured to operate in a first, styling mode and airflow is guided by the guide 120 across the curved surface 104. When the main body 102 is in the second position, as shown in Figures 3 and 4, the haircare appliance 100 is configured to operate in a second, drying mode and airflow exits the air outlet 110 towards a user’s hair.

The first and second positions of the main body 102 are 180 degrees apart from one another. That is, the main body 102 is rotated by 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 one another.

The attachment 100 comprises a handle 112 protruding from a distal end of the main body 102. The distal end is an opposite end of the main body 102 to the air inlet 108. The handle 112 is rigidly attached to the main body and is rotatable by a user to rotate the main body 102 relative to the guide 120 between the first and second positions. It will be appreciated that the handle 112 could be provided in any suitable form for operation by a user to rotate the main body 102 relative to the guide 120, for example a toggle, push button or touch screen. The handle 112 is comprised in a cool tip which is relatively insulated from the heat of the airflow within the attachment.

The guide 120 is arranged to turn airflow exiting the air outlet 110 towards the curved surface 104 when the main body 102 is in the first position, as shown in Figures 5, 7 and 8. The inventors of the present application have found that airflow attaches to the curved surface 102 via the Coanda effect. With reference to the schematic illustration of the interaction of forces shown in Figure 6, when a tress of hair is brought into the vicinity of the attachment 100, long hairs of the tress are attracted to, and at least partially wrapped about, the curved surface 102 by a force F PULL, as a result of a negative pressure region generated by the airflow over the curved surface 102. However, the pressure gradient across the tress also results in a force, F PUSH, which causes some airflow to pass directly through the tress. Due to the location of this force relative to the curved surface 102 and the rest of the tress, shorter hairs are only held loosely at this point compared to longer hairs which are held in place on the curved surface 102. The shorter hairs are blown through the tress toward a user’s head, whilst the longer hairs remain in place on the outside of the tress, ie the portion of the tress facing away from the user’s head. This provides a smooth finish for hair following interaction with the haircare appliance 10.

This effect can be optimised by appropriate modification of the geometries and parameters described herein. One such parameter that may provide increased effectiveness is the velocity of airflow at the air outlet 110 of the attachment 100. In particular, too great a velocity may result in shorter hairs sticking to the curved surface 102 and hence not being pushed away through longer hairs, whilst too low a velocity may not be sufficient to attract longer hairs to the curved surface 102 in the first instance.

The guide 120 comprises a first channel 122 defining a first air outlet 126, a second channel 124 defining a second air outlet 128, first and second flat surfaces 130, an inner casing 132 defining an aperture 133, a pair of guide walls 134, a switching member 140 and a retention mechanism 150, as will be described in more detail herein after. It will be appreciated that in other embodiments some of these features may be omitted.

The inner casing 132 is arranged to contact the curved surface 104 at least when the main body 102 is in the first position. The inner casing 132 defines an aperture 133 corresponding to the air outlet 110 to allow airflow to flow from the air outlet 110 to the first and second channels 122, 124. The inner casing 132 comprises raised ridges on opposite sides of the aperture 133, the ridges defining convex curved surfaces for guiding airflow from the radial direction towards the curved surface 104 of the main body 102 to provide a smoother flow path for the airflow and thus help reduce turbulence in the airflow.

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

The curved surface 104 comprises a continuous surface extending between the first and second air outlets 126, 128, when the main body 102 is in the first position.

The first and second air outlets 126, 128 comprise rectangular slots extending substantially parallel to the longitudinal axis 103 of the main body. The first and second air outlet 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 an open cross-sectional area of the air outlet 110. This provides an increase the velocity of airflow at the first and second air outlets 126, 128 compared with the velocity of airflow at the air outlet 110 for the same air flow rate, 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 with a fixed cross-sectional area, length and width.

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

In a presently preferred embodiment, the width of the first and second air outlets 126, 128 is in the region of 77mm, and the height of the first and second air outlets 126, 128 is in the region of 4.5mm. The open cross-sectional area of the first and second air outlets 126, 128 is in the region of 346.5mm². The inventors of the present application have found that such dimensions for the first and second air outlets 126, 128 may provide advantageous effects, as will be described hereafter.

The applicant has determined that a velocity in the region of 30m/s to 65m/s at the first or second air outlet 126, 128 may be particularly effective in generating an airflow along the curved surface 102 that results in a first force that is sufficient to attract relatively long hair toward the curved surface 102 whilst also generating a second force to push relatively short hair away from the curved surface 102. In a presently preferred embodiment, the velocity of airflow at the first or second air outlet 126, 128 is in the region of 55m/s.

Another parameter that may provide increased efficacy for smoothing hair in the manner described above is a ratio of the velocity of airflow at the first or second air outlet 126, 128 to a flow rate of airflow generated by the airflow generator 16. In the embodiment of Figures 5, 7 and 8, the ratio is in the region of 2.14 to 5.63, and in a particularly preferred embodiment the ratio is in the region of 2.89. The applicant has found that such a ratio may be particularly effective in generating an airflow along the curved surface 102 that results in a first force that is sufficient to attract relatively long hair toward the curved surface 102, whilst also generating a second force to push relatively short hair away from the curved surface 102.

Another parameter that may provide increased efficacy for smoothing hair in the manner described above is a ratio of flow rate of airflow generated by the airflow generator 16 to an open cross-sectional area of the first or second air outlet 126, 128. In the embodiment of Figures 5, 7 and 8, the ratio is in the region of 0.01 to 0.10, and in a particularly preferred embodiment the ratio is in the region of 0.04. The applicant has found that such a ratio may be particularly effective in generating an airflow along the curved surface 102 that results in a first force that is sufficient to attract relatively long hair toward the curved surface 102, whilst also generating a second force to push relatively short hair away from the curved surface 102.

A further parameter that may provide increased efficacy for smoothing hair in the manner described above is a ratio of a radius of curvature of the curved surface 102 to the velocity of airflow at the first or second air outlet 126, 128. In the embodiment of Figures 5, 7 and 8, the ratio is in the region of 0.33 to 2.00, and in a particularly preferred embodiment the ratio is in the region of 0.57. The applicant has found that such a ratio may be particularly effective in generating an airflow along the curved surface 102 that results in a first force that is sufficient to attract relatively long hair toward the curved surface 102, whilst also generating a second force to push relatively short hair away from the curved surface 102.

The flat surfaces 130 are located adjacent to and extending rearwardly from of the first and second air outlets 126, 128, such that the flat surfaces 130 extend rearwardly from an edge of the first and second air outlets 126, 128. The flat surfaces 130 are obliquely angled relative to a respective plane in which the first and second air outlets 126, 128 are disposed, for example at an angle in the range of 3-10 degrees. The flat surfaces 130 are generally planar in form, and are substantially smooth and uninterrupted, for example with no projections, recesses or apertures formed thereon. The flat surfaces 130 have a height in the region of 5mm to 20mm. The functionality of the flat surfaces 130 will be described hereafter. It will be appreciated that in embodiments in which the guide 120 comprises only one channel defining a channel outlet 126, 128, the guide comprises a single flat surface 130 adjacent to and extending rearwardly from the channel outlet 126, 128.

The pair of guide walls 134 are for directing airflow along the curved surface 104 and are disposed on opposing edges of the curved surface 104. The guide walls 134 are upstanding from the curved surface 104. The guide walls 134 extend along the full arc length of the curved surface 104. In this embodiment the guide walls 134 extend around the main body 102 to form a pair of rings within which the main body 102 rotates. That is, the guide walls 134 extend from around the main body 102 from the first air outlet 126 to the second air outlet 128. The guide walls 134 have a height substantially corresponding to a height of the first and second air outlets 126, 128, and have a constant height along their length.

As mentioned above, the pair of guide walls 134 extend along opposing edges of the curved surface 104. This effectively creates an airflow channel, with the pair of guide walls 134 acting as walls of the channel, and the curved surface 104 acting as a bed of the channel. The guide walls 134 inhibit ambient air from interacting with airflow flowing along the curved surface 104 in use, which may maintain the negative pressure region created by airflow flowing along the curved surface 104.

The attachment 100 comprises a switching member 140 for switching airflow between the first and second air outlets 126, 128. The switching member 140 is movable from a first switch position (as shown in Figure 7) to a second switch position (as shown in Figure 8). In the first switch position, and when the main body 102 is in the first position, airflow passes through the first air outlet 126 across the curved surface 104 and does not pass through the second air outlet 128. In the second switch position, and when the main body 102 is in the first position, airflow passes through the second air outlet 128 across the curved surface 104 and does not pass 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 when the switching member 140 is in the first switch position and the second switch position, to block the first or second channel 122, 124. In this embodiment, an edge of the switching member 140 is arranged to contact the inner casing 132 of the guide 130 to block airflow to the respective first or second channel 122, 124 and allow airflow to pass through the other of the first or second channel 122, 124.

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

The switching member 140 comprises an arced, or curved surface 146 for turning airflow toward the first or second air outlet 126, 128. The switching member 140 thus forms a concave surface for guiding airflow from a radial direction of the main body 102 towards a tangential direction of the curved surface 104.

The attachment 100 comprises a handle 142 positioned on the switching member 140. The handle 142 is movable by a user to move the switching member 140 between the first switch position and the second switch position. The switching member 140 and the handle 142 form a single body. It will be appreciated that any other suitable user interface could be employed to move the switching member 140 between the first and second switch positions.

The switching member 140 is movable between the first and second switch positions about a pivot 144 such that the switching member 140 rotates about the pivot 144. The switching member 140 rotates about the pivot 144 by an angle in the regions of 18 degrees to 30 degrees to move between the first and second switch positions, for example between 22 and 26 degrees. The handle 142 is positioned on an outer portion of the switching member 142, the outer portion being further from the longitudinal axis 103 of the main body 102 than the pivot 144. The handle is therefore more easily accessible to the user. It will be appreciated that in other embodiments, the switching member 140 may move between the first and second switch positions in any suitable way, such as sliding of the switching member 140 relative to the air outlet 110.

The attachment 100 comprises a retention mechanism 150. The retention mechanism is for retaining the switching member 140 in one of the first and second switch positions in the absence of an applied force to the handle 142 of the switching member 140 by a user of the haircare appliance 10. The retention mechanism 150 is arranged to retain the switching member 140 in the other switch position upon application of an applied force to the handle 142 of the switching member 140 by a user of the haircare appliance 10. With reference to Figures 7 and 8, the retention mechanism 150 holds the switching member 140 in the first switch position shown in Figure 7 until a user applies a force (denoted by arrow 152) to the handle 142. Upon application of the force 152, the switching member 140 is released from the first switch position and moved to the second switch position shown in Figure 8, where it is held by the retention mechanism 150 until application of force to the handle 142 by a user.

The retention mechanism 150 comprises a first pair of magnetic elements 154 configured to retain the switching member 140 in the first switch position and a second pair of magnetic elements 156 configured to retain the switching member 140 in the second switch position. A first magnetic element in each of the pairs of magnetic elements 154, 156 is located on an inner side of the respective flat surface 130 and a second magnetic element in each of the pairs of magnetic elements 154, 156 is located at an opposing location on the switching member 140 to the first magnetic element in the respective pair of magnetic elements 154, 156. In this example, the first magnetic element in each of the pairs of magnetic elements 154, 156 comprises a sheet metal and the second magnetic element in each of the pairs of magnetic elements 154, 156 comprises a magnet arranged to attract the sheet metal. It will be appreciated that the retention mechanism may comprise other forms of retention, such as releasable mechanical fasteners and a biasing element.

The second magnetic element in each of the pairs of magnetic elements 154, 156 is positioned on an inner portion of the switching mechanism 140, the inner portion being closer to the longitudinal axis 103 of the main body 102 than the pivot. This may prevent a user from being able to access the magnetic elements and thus tamper with them.

A minimum force 152 required to overcome the retention mechanism 150 to move the switching member 140 between the first switch position and the second switch position is in the region up to 5N, more specifically 0.3N to 3N.

The attachment 100 comprises a rib 148, which, in this embodiment, is connected to the switching member 140. The rib 148 is positioned such that it interacts with airflow exiting the air outlet 110 to align the airflow exiting the air outlet 110, thus providing a more laminar flow at the respective first of second air outlets 126, 128. The rib 148 is positioned relative to the first and second channels 122, 124 to smooth airflow in the first and second channels 122, 124 and thus provide a more laminar airflow at the first and second air outlets 126, 128 before the airflow flows across the curved surface.

The rib 148 interacts with airflow exiting the air outlet 110 to provide a more aligned, smoother, more laminar flow at the first air outlet 126 which in turn provides a more cohesive airflow across the curved surface 104. As airflow is turned, the airflow typically separates and thus becomes more turbulent and noisy. The rib 148 has an upper and a lower surface along which airflow passes as it flows through the first and second channels 122, 124 which helps to reduce flow separation and thus turbulence and noise compared to an attachment 100 without the rib 148. The rib 148 is movable relative to the air outlet 110 by virtue of being connected to the switching member 140. The rib 148 may thus be movable relative to the air outlet 110 by a user applying a force to the handle 142 to move the switching member 140, and therefore the rib, between the first and second switch positions.

The rib 148 is elongate, having a length at least as long as a length of the air outlet 110 such that the rib 148 interacts with air across substantially all of the length of the air outlet 110

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

The rib 148 is held apart from the curved surface 146 of the switching member 140 by connecting members 149 (best shown in Figure 9) to allow airflow to flow across either side of the rib 148. Airflow exiting the air outlet 110 is bisected by the rib 148 and passes between adjacent connecting members 149, when the main body 102 is in the first position.

The connecting members 149 are spaced along a length of the rib 148. The connecting members 149 rigidly connect the rib 148 to the switching member 140 such that the rib 148 is immovable relative to the switching member 140. It will be appreciated that in other embodiments, the rib 148 may be movable relative to the switching member 140.

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

The haircare appliance 10 comprises an alert module 36. The alert module is arranged to provide to alert a user that the main body 102 is in the first position or the second position and/or to alert a user that the switching member 140 is in the first switch position of the second switch position. The alert module 36 comprises one or more of a haptic feedback module, an audible indicium or a visual indicium. In this embodiment the alert module 36 is shown as being in the handle unit 12, but it will be appreciated that in other embodiments the alert module 36 may be comprised in the attachment 100. The haircare appliance 10 may comprise separate alert modules 36 for the main body 102 and the switching member 140.

In use, the attachment 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 airflow passes from the air outlet 24 of the handle unit to the air inlet 108 of the attachment 100. Airflow flows from the air inlet 108 of the attachment through the main body 102, and is turned by the plurality of internal baffles 114 toward the air outlet 110 of the attachment 100. Airflow exits the main body 102 via the air outlet 110 and passes over the curved surface 102 if the main body 102 is in the first position or flows in a radial direction of the main body 102 if the main body 102 is in the second position.

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

In use, the switching member 140 is moveable between the first and second switch positions upon application of a force by a user to the handle 142. The force may be applied by a user’s hand, or force generated upon contact between the handle 142 and the user’s hair and/or head. The handle 142 is located at a rear edge of the flat surfaces 130 and therefore may contact the user’s hair and/or head in use, as described in more detail hereinafter, to move the switching member between the first and second switch positions.

In use, the attachment 100 can be moved along a length of a tress of hair, for example in a direction from root to tip of hair of the tress. A respective one of the flat surfaces 130 is positioned relative to the curved surface 104 such that the flat surface 130 contacts hair extending rearwardly from of the air outlet 110 whilst hair downstream of the air outlet 110 contacts the curved surface 104. As previously mentioned, the flat surface 130 is substantially smooth and uninterrupted in form, with no projections, recesses or apertures formed thereon. As the haircare appliance 10 is moved along a length of a tress of hair in use, the flat surface 130 passes across hair that has been smoothed via interaction with the 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 already been smoothed, leading to a better finish than, for example, a corresponding haircare appliance that has bristles and/or further air outlets located rearwardly of the air outlet 110.

Referring now to Figures 10a to 12b, alternative arrangements will be discussed, for these Figures features in common with those previously described will use the same reference numbers.

In Figures 10a and 10b, the attachment 200 is similar to the one described with respect to Figures 3 and 4 however, instead of having a single air outlet 110, there are two air outlets 110a and 110b. The attachment 200 comprises a main body 102 comprising an air inlet 108, air outlets 110a, 110b, a curved surface 104, and a plurality of internal baffles 114. The attachment 200 has two modes, a first mode where air is directed out of the attachment by the guide 220 and a second mode where air exits directly from the air outlets 110a, 110b. In the configuration shown the guide 220 is not aligned to either one of the air outlets 110a, 110b. However, the functioning of the attachment 200 in the first mode will be described. In this example, a switching baffle 240 extends from an inner surface of the guide 220 to engage with one or other sides of a rib 202 provided between the first air outlet 110a and the second air outlet 110b opening one of these outlets and blocking the other. The guide 120 comprises a first channel 122 defining a first air outlet 126, a second channel 124 defining a second air outlet 128. The first channel 122 is arranged to direct airflow in a first direction across the curved surface 104. The second channel 124 is arranged to direct airflow in a second direction across the curved surface 104 dependent on which of the air outlets 110a, 110b is open as has been previously described. The main body 102 is rotatable about its central longitudinal axis 103 relative to the guide 120, between a first position in which airflow exiting the air outlets 110a, 110b is directed by the guide 120, and a second position in which airflow exiting the air outlets 110a, 110b is not directed by the guide 120, as shown in Figures 10a and 10b. In this configuration, air flows directly out from the air outlets 110a and 110b and, in this version, gives a rough-drying functionality to the attachment. This is as opposed to the smoothing function provided when the guide 120 is aligned with one of the air outlets 110a, 110b, as has been previously described.

Figures 11a and 1 lb show an attachment 230 with a single air outlet 110 which can align with the guide 220 to provide a styling function, in this case a smoothing function or, as shown in the Figures, can be misaligned to the guide 220 so air exits the air outlet 110 directly towards a user or customer. In this example, the switching mechanism 232 is internally housed within the main body 102 and is actuated between the first position and the second position by a user twisting an actuator 234.

Figures 12, 12ba and 12c show an attachment 250 having a second position which has a second function which is a styling function as it provides a concentrated stream of air out of a single air outlet 110.

In the first mode, air exits via the guide 220 which comprises a first channel 122 defining a first air outlet 126, a defining a second air outlet 128. A switching member 140 is provided in the main body 102 and this rotates relative to the guide 220 to direct air flow to either the first air outlet 126 or the second air outlet 128. A switching baffle 240 extends from an inner surface of the guide 220 to engage with one side of the air outlet 110 of the main body 102 to direct the air flow to either the first channel 122 or the second channel 124.

In a second mode, shown in Figure 12c, the main body 102 is rotated by 180° with respect to the guide 140 and air outlet 110 aligns with a further channel 262 provided in a secondary housing 270 and air exits via slot 260 which extends along the length of the secondary housing 270. The further channel 262 is narrower than the air outlet 110, concentrating the flow as it moves along the further channel 262 towards the slot 260. This provides a higher velocity flow than if the air just exited from the air outlet 110. The secondary housing 270 and the guide 140 are both substantially C-shaped and the space defined by the open ends of each enables the air outlet 110 to align with the air exit provided in either the guide 140 or the secondary housing 270.

The channel 262 could alternatively be wider than the air outlet 110 to provide a more diffuse flow from the slot. The person skilled in the art will appreciate such variations are possible.

Although described herein as embodiments with releasable attachments, embodiments are also envisaged where, rather than the haircare appliance comprising a handle unit and an attachment the haircare appliance is a single-piece unit, for example taking the form of the combined handle unit and attachment previously described.

Claims

1. An attachment for a haircare appliance, the attachment comprising: a main body comprising an air inlet and an air outlet; and a guide for directing airflow from the air outlet across a curved surface of the main body, such that airflow directed by the guide generates a first force to attract hair toward the curved surface, and a second force to push hair away from the curved surface, wherein the main body is rotatable relative to the guide between a first position in which airflow exiting the air outlet is directed by the guide and a second position, in which airflow exiting the air outlet is not directed by the guide.

2. An attachment as claimed in Claim 1, wherein the first position and the second position are 180 degrees apart from one another.

3. An attachment as claimed in any preceding claim, wherein the main body is generally cylindrical and configured to direct airflow exiting the air outlet in a radial direction.

4. An attachment as claimed in any preceding claim, comprising a user interface operable by a user to rotate the main body relative to the guide between the first position and the second position.

5. An attachment as claimed in Claim 4, wherein the user interface comprises a handle protruding from a distal end of the main body, wherein the handle is rigidly attached to the main body and is rotatable by a user to rotate the main body relative to the guide between the first position and the second position.

6. An attachment as claimed in any preceding claim, wherein the guide comprises an inner casing arranged to contact the curved surface, wherein the inner casing defines an aperture corresponding to the air outlet.

7. An attachment as claimed in any preceding claim, wherein the guide comprises a first channel arranged to direct airflow in a first direction across the curved surface, and a second channel arranged to direct airflow in a second, opposite direction across the curved surface.

8. An attachment as claimed in Claim 7, wherein the first and second channels define rectangular slots, the rectangular slots extending substantially parallel to a longitudinal axis of the main body.

9. An attachment as claimed in Claim 7 or Claim 8, wherein the first channel and the second channel each have a smaller open cross-sectional area than the air outlet.

10. An attachment as claimed in any one of claims 7 to 9, wherein the haircare appliance comprises a switching member for switching airflow between the first and second channels, the switching member movable from a first switch position in which airflow passes through the first channel across the curved surface in a first direction and does not pass through the second channel, to a second switch position in which airflow passes through the second air outlet across the curved surface in a second, opposite direction and does not pass through the first channel.

11. An attachment as claimed in Claim 10, comprising a retention mechanism for retaining the switching member in one of the first and second switch positions in the absence of an applied force to the switching member by a user of the attachment.

12. An attachment as claimed in Claim 11, wherein the retention mechanism comprises a first pair of magnetic elements configured to retain the switching member in the first switch position and a second pair of magnetic elements configured to retain the switching member in the second switch position.

13. An attachment as claimed in any of claims 10 to 12, wherein the switching member is comprised in the guide.

14. An attachment as claimed in any of claims 10 to 13, wherein the switching member is elongate, extending substantially parallel to a longitudinal axis of the main body, and is at least at long as a length of the air outlet.

15. An attachment as claimed in any one of claims 7 to 14, wherein the guide comprises a first flat surface adjacent to and extending rearwardly from the first channel, and a second flat surface adjacent to and extending rearwardly from the second channel.

16. An attachment as claimed in any preceding claim, comprising a pair of guide walls for directing airflow along the curved surface, the pair of guide walls upstanding from the curved surface.

17. An attachment as claimed in Claim 16, wherein the guide walls extend around the main body and the main body is configured to rotate within the pair of guide walls.

18. An attachment as claimed in any preceding claim, comprising a rib positioned such that the rib interacts with airflow in the first or second channel to align airflow.

19. An attachment as claimed in claim 1 comprising a secondary housing extending at least partially between the main body and the guide; the secondary housing comprising a second air outlet wherein the second air outlet aligns with the air outlet from the main body when the main body is in the second position.

20. A haircare appliance comprising: a main body comprising an air inlet and an air outlet; an airflow generator for generating an airflow from the air inlet to the air outlet; and a guide for directing airflow from the air outlet across a curved surface of the main body, such that airflow directed by the guide generates a first force to attract hair toward the curved surface, and a second force to push hair away from the curved surface, wherein the main body is rotatable relative to the guide between a first position in which airflow exiting the air outlet is directed by the guide and a second position, in which airflow exiting the air outlet is not directed by the guide.

21. A haircare appliance as claimed in Claim 19, comprising a handle unit within which the airflow generator is housed, and an attachment releasably attachable to the handle unit, the attachment comprising the main body and the guide.