In a conventional hot styling brush, air is sucked into an inlet by a fan unit and directed towards the hair by an attachment or head. Depending on the style desired, the air may or may not be heated. The head or attachment often includes bristles onto which hair is wrapped and held for styling. The air is generally blown out of the head or attachment normal to the surface of the head.

The present invention provides an attachment for a hand held appliance comprising a body having a first wall; a second wall; and a slot formed along at least part of the length of the attachment, wherein the slot is defined on a first side by a surface of the first wall and on a second side by a surface of the second wall.

Preferably, the first wall is generally tubular.

It is preferred that the surface of the second wall is substantially linear.

Preferably, the second wall extends out from the first wall. Fluid that exits from the outlet will flow along the second wall and pull hair towards the second wall increasing drying speed and helping to align the individual hair strands.

It is preferred that the second wall is moveable relative to the first wall. Preferably, the second wall is rotatable with respect to the first wall. It is preferred that the second wall is generally triangular. Preferably, two slots are provided and the second wall separates the two slots.

It is preferred that the second wall divides the slot into two. It is preferred that a slot is provided either side of the second wall.

Alternatively, the slot is formed on one side of the second wall or the other side of the second wall.

Preferably, the second wall has a first indexed position defining a first slot position.

It is preferred that the second wall has a second indexed position defining a second slot position.

Preferably, an indexed position is defined by a detent mechanism. It is preferred that the detent mechanism includes an actuator biased into a recess. Preferably, the actuator is a ball bearing. It is preferred that the actuator is biased by a spring.

Preferably, an external surface of the attachment includes at least one row of bristles. It is preferred that the external surface is an external surface of the first wall. Preferably, the external surface comprises a first set of bristles comprising at least one row of bristles and a second set of bristles comprising at least one row of bristles.

It is preferred that the first set of bristles and the second set of bristles are spaced apart on the external surface. Preferably, the external surface is forms at least part of the circumference of a circle and the first set of bristles is radially spaced from the second set of bristles.

According to a second aspect, the invention provides a hand held appliance comprising a handle having a fluid flow path from a fluid inlet to a fluid outlet and a fan unit for drawing fluid into the fluid inlet and an attachment for attaching to the handle, the attachment comprising a body having a first wall; a second wall; and a slot formed along at least part of the length of the attachment, wherein the slot is defined on a first side by a surface of the first wall and on a second side by a surface of the second wall.

In one embodiment the appliance is a hair care appliance.

In another embodiment the appliance is a hot styling appliance such as a hot styling brush.

The invention will now be described by example, with reference to the accompanying drawings, of which:

Figure la shows an example of an appliance according to the invention;

Figure lb shows a cross section through the appliance shown in Figure la;

Figure 2a shows an exploded view of some of the handle components of the device of Figure la;

Figure 2b shows an enlarged section of the fluid inlet;

Figures 3a and 3b show an isometric view and an isometric cross section through a first attachment according to the invention;

Figures 4a and 4b show a side view and a side view cross section through the first attachment;

Figures 5a and 5b show cross sections through the first attachment;

Figures 6a and 6b show an isometric view and a side view through a second attachment;

Figure 7a shows an isometric view through another attachment; Figures 7b and 7c show an isometric view and a side view through a further attachment; Figure 8a shows an isometric view of a fifth attachment;

Figure 8b shows an isometric view of a sixth attachment;

Figure 9 shows a two part assembly for an attachment; Figures 10a and 10b show an isometric view and an isometric cross section through a further attachment according to the invention;

Figures 11a, 1 lb and 11c show a side view and a side view cross sections through the further attachment;

Figures 12a and 12b show cross sections through the further attachment in a first position;

Figures 13a and 13b show cross sections through the further attachment in a second position;

Figure 14 shows schematically the further attachment in use; and Figure 15a shows an isometric view of another attachment;

Figure 15b shows different component parts of the other attachment; Figure 15c shows the different component parts from the inlet end; Figure 15d shows a cross section through the side of the other attachment; Figure 15e shows a cross section through the other attachment; and

Figures 16a and 16b show an alternative sock for the other attachment. Figures la and lb shows a hot styling brush 10 with a handle 20 and a detachable head or attachment 30 which is attaches at the distal end 22 of the handle 20 to the fluid inlet 40.

The handle 20 has an outer wall 26 which is generally tubular and includes the fluid inlet 40 at and adjacent one end 24. The fluid inlet 40 comprises a first set of apertures 44 which extend radially around the handle 20 and along the outer wall 26 of the handle from the handle end 24. The handle end 24 is covered by an end wall 42 which is also perforated with a second set of apertures 46 that extend through the end wall 42 of the handle. Thus, the fluid inlet 40 extends around, along and across the handle 20. The end wall 42 is orthogonal to the outer wall 26 and an inner wall 60 of the handle.

The handle 20 also includes a fan unit 70 which comprises a fan and a motor which drives the fan and in use, draws fluid in through the fluid inlet 40, along a fluid flow path 50 which extends through the length of the handle 20. The fluid is optionally heater by a heater 80 before entering an inner cavity 38 of the head 30.

The head 30 includes a fluid outlet 100 which in this example comprises parallel slots 102 each extending towards a second end 36 of the head and radially around the head 30. This arrangement enables fluid to exit the head all the way around the head and for the majority of the length of the head 30 maximising a hair styling region of the product.

In use, hair is wrapped around the head 30 whilst air or fluid exits through the slots 102 drying the hair and/or styling the hair into curls or waves. The hair wraps automatically due to the flow of air around the surface of the head 30. The air or fluid can be heated but this is not essential. Power is provided to the appliance via a power cable 48 which preferably extends from a plug or other power source through the end wall 42 of the handle 20. The handle 20 also houses a PCB 75 which is electrically connected to the cable 48, the fan unit 70 and the heater 80 by internal wiring (not shown). An on/off switch 52 and control buttons 54 are provided and connected to the PCB 75 to allow the user to select one of a range of temperature and flow settings.

Figure 2a shows an exploded view of various parts of the handle 20 in more detail. The handle 20 is tubular and the outer wall 26 of the handle 20 is a cylindrical sleeve made from for example an extruded tube or rolled sheet of metal such as aluminium, an aluminium alloy or a steel. The handle connects to a head 30 at a first end 22 and at the distal, second end 24 a fluid inlet 40 is provided. The fluid inlet 40 is a first means of filtering fluid that enters the fluid flow path 50.

The fluid inlet 40 comprises a plurality of apertures extending around, along and across the handle 20. Having an inlet that extends in three dimensions has advantages particularly when used with hair grooming appliances. Firstly, if the appliance is placed on a surface whilst switched on only a small part of the inlet surface area will be blocked or have restricted flow of fluid into the appliance. This protects the fan unit and particularly the motor of the fan unit from running with too low a flow rate as this can cause overheating of the motor and cause damage to the motor.

Secondly, often hair care appliances are used with a styling product such as a mousse, gel or spray. These products are typically either applied by a hand or directly to the hair as a mist. After application by a hand, some of the product will be retained on the skin which is then transferred to the appliance when held. This can block at least some of the apertures 44 that extend around and along the handle 20. However, the apertures 46 that extend under the handle and across the end wall 42 of the handle will be unaffected. When a product is applied as a mist, it can settle on the appliance and again block or restrict at least some of the apertures of the fluid inlet 40. However, by having apertures that extend around, along and across the handle 20 the risk of blocking the fluid inlet 40 is reduced.

The apertures are preferably circular with a diameter of 0.2 to 1.6 mm. The diameter of the apertures can vary along, around and across the handle 20. It is advantageous to space the apertures regularly around, along and across the fluid inlet 40. Not only is this visually pleasing but it also has the technical advantage that there is no weak region of the fluid inlet 40 where blockage of a portion is more likely or would have more impact on the flow into the fluid inlet 40. The inlet is designed so that the flow into the inlet is even at least around the circumference of the handle 20.

A foam block 48 is provided which in use is inserted into the second end 24 of the handle 20. The foam block 48 is a second means of filtering the fluid that passes through the primary fluid inlet 40 into the primary fluid flow path 50. It is

advantageous that the foam block 48 extends beyond or further towards the first end 22 of the handle than the primary fluid inlet 40 as this ensures that fluid that has entered the primary fluid inlet 40 has passed through the foam block 48 so has had two stages of filtration. In other words, the foam block 48 extends from the second end 24 of the handle 20 past the downstream end 44a of the fluid inlet.

The foam block 48 shown is cylindrical and substantially fills the area within the handle 20 at the primary fluid inlet 40. This is to ensure that all fluid that enters the primary fluid inlet through first apertures 44 that extend around and along the handle and fluid that enters through second apertures 46 that extend across and through the end wall 42 of the handle 20 passes through this second stage of filtration. The foam block 48 extends longitudinally from the second end 24 of the handle 20 further than the first apertures 42 of the primary fluid inlet 40.

The first apertures 44 that extend along and around the outer wall 26 are machined, punched or laser cut from the extruded tube or sheet metal that the outer wall 26 is formed from. The handle 20 has an outer wall 26 and an inner wall 60, the outer wall 26 slides over the inner wall 60 to form the finished product. The inner wall 60 is a duct which surrounds and defines a fluid flow path 50 through the appliance. The outer wall 26 includes a grippable portion and in these examples, includes the fluid inlet 40 into the fluid flow path 50. An insulting layer of material 28 is provided within the inner wall 60. The insulating layer is a foam or a felt and insulates the handle from noise produced by the fan unit 70, heat produced by the operation of the appliance, vibrations caused by the fan unit and noise produced within the appliance by the flow of fluid through the fluid flow path 50. The insulating layer absorbs energy including airborne noise.

The inner wall 60 provides a housing 62 in which a fan unit 70 is disposed. The housing 62 is cylindrical and has an inwardly protruding ledge 64,66 disposed one at each end of the housing 62 which maintain the position of the fan unit 70 within the handle 20. The inner wall 60 is made from two parts a first part 60a and a second part 60b which is moulded separately. This enables easier assembly of the fan unit 70 within the handle 20 than a one piece inner wall. A similar pair of inwardly protruding ledges 68, 72 maintains the position of the heater 80 within the handle 20. Although the outer wall 26 of the handle 20 has been described as being made from an extruded tube or a rolled sheet of metal, alternatives methods of manufacture and materials could be used; these include, but are not limited to, a plastic

extrusion/moulded tube or a composite tube such as carbon fibre reinforced plastic. The fluid outlet 100 of the head 30 will now be described in more detail, referring in particular to Figures 3a, 3b, 4a, 4b, 5a and 5b. The head 30 is essentially cylindrical and has a first end 32 for connection to a handle 20 and a second end 36 distal to the first end 32. The head 30 extends longitudinally from the first end 32 to the second end 26 continuing a line described by the handle 20 (Figure la) so is approximately the same diameter as the handle. Within the head 30 is an inner cavity 38 and fluid that has been drawn into the fluid flow path 50 within the handle 20 by the fan unit 70 enters the inner cavity 38 via an aperture 302 in the first end 32 of the head 30.

The fluid outlet 100 is formed from a number of parallel slots 102 which extend along the length of the head 30 from the first end 32 to the second end 36. The slots 102 are formed from an overlap 120 (Figure 5b) formed between adjacent plates 110 which results in fluid being directed between a radially inner surface 104 formed from the outer surface 112 of a first plate 110a and a radially outer surface 106 formed from the inner surface 114 of a second plate 110b. The fluid 122 flowing out of the slot 102 is tangential 130 to the outer surface 112 of the plate 110a and joins with the fluid flowing out of the other slots of the fluid outlet 100 forming a fluid flow around the

circumference of the head 30. Thus, the fluid 122 is blown out along the external surface of the head and this encourages hair to wrap around the head 30 automatically. The fluid 122 exiting the slots 102 is attracted to the curved surface of the head 30 by the Coanda effect. This in turn causes hair that is presented to the head 30 to automatically wrap around the surface and then styled into curls. As air is blown down the length of the hair, wet hair is dried more quickly than conventionally and as the wrapping process occurs without the use of bristles, the hair can slide off the head 30 once it is dry or styled so there is no tangling.

To maintain the size of each slot 102, spacers 108 are provided. In this example, a pair of spacers 108 is provided to maintain each slot 102 size. Each one of the pair of spacers 108 is longitudinally spaced along the slot 102 and the plate 1 10. The spacers 108 join adjacent plates 110 together.

Advantageously, each plate 110 is lined with a felt like material 308 such as Kevlar or wool (see Figure 3b). The material 308 does not extend over each slot 102 so the fluid exiting the fluid outlet 100 does not pass through the layer of material 308. This layer serves to absorb some of the noise produced by the fluid flowing through the head 30 from the inlet to the head 30 at aperture 302 to the fluid outlet 100. Such a layer of material 308 is as applicable for other heads herein described such as heads 130, 180 and 230.

Figures 6a and 6b show an alternative head 130, all features identical to those previously described have the same reference numerals. The head 130 has a larger diameter than the handle 20 so is used to create larger curls. The head 130 has a first end 32 for connection to the handle 20 and this is the same diameter as the handle 20, within a collar 132 of the head 130, the diameter of the head 130 increases to the larger diameter prior to the fluid outlet 100 formed by slots 142 and then continues at a constant diameter to the second end 136. An inner fluid cavity (not shown) is larger than for the head 30 of Figure 3a. In this example the number of plates 1 10 and slots 102 is the same i.e. six as for the head described with respect to Figure 3a.

Alternatively, a larger or smaller number of plates 110 and slots 142 could be used. Figure 7a shows a further head 230. This head 230 has a reduced diameter compared with the handle 20. The first end 32 is substantially the same diameter as the handle 20 for connection thereto, and then within a collar 232 the diameter of the head 230 decreases to the reduced diameter prior to the fluid outlet 200 formed by slots 202 and continues at a constant diameter to the second end 236. This head 230 is used to create tighter curls.

The slots 202 for this head extend longitudinally straight from the first end 32 to the second end 236 as was the case for slots 102 in heads 30, 130. In another embodiment, as shown in Figures 7b and 7c, a further head 280 has slots 282 which curve around the head 280 forming a spiral or helical pattern around the head 230. The slots 282 curve by an angle a of 45° from the longitudinal axis A-A of the handle 20 and head 280. In this example the slots 282 curve in a clockwise direction from the first end 34 of the head 280 towards the second end 236 of the head. The slots 282 are formed as before between adjacent overlapping plates 210 however, in order to form the curved slots 282, the plates 210 do not extend along the longitudinal axis of the head 280 but also curve by an angle of 45°. Using angled slots changes the profile of the fluid exiting from the head. The airflow exiting from the slots is more normal to the slot when angled slots are used. This has benefits including enabling more hair to be wrapped around the head also, the hair is retained on the head more easily leading to a potentially quicker styling process.

The slots can be curved in a clockwise or and anticlockwise direction from the longitudinal axis A-A of the handle 20. Whilst an angle of 45° has been illustrated, improved wrapping is seen even at an angle of 1°.

Figure 8a shows a head 180 which is substantially the same diameter as the handle 20. The slots 182 are curved or spiral around the head 180 in the same manner as head 280.

Figure 8b shows a head 380 which has a larger diameter than the handle, and is similar to head 130 except it has curved or spiralling slots 382 around the head 380.

Figures 9a and 9b show a way of assembling head 30. A first part 150 is formed from the first end 32 and has a collar 152 and a first set of plates 154 which are joined to or formed integrally with the collar 152. A second part 160 is formed from the second end 36 and has an end wall 162 and a second set of plates 164 which are joined to or formed integrally with the end wall 162. The first set of plates 154 and second set of plates 164 each comprise non-adjacent plates 110 enabling the first part 150 and the second part 160 to be slotted together to form the head 30. Between each of the first set of plates 154, a recess 156 is provided in the connecting ring 152 adapted to accommodate the distal end 164a of the second set of plates 164 from the end wall 162. A similar set of recesses 166 is provided in the end wall 162 and is adapted to accommodate the distal end 154a of the first set of plates from the collar 32.

In order to retain the first part 150 and the second part 160 of the head 30 in the assembled condition, a protruding screw hole 168 is provided. Near the distal end 154a of the first set of plates 154 a support scaffold 170 is provided and this has two functions. A first function is to support the first set of plates 154 and maintain their relative positions towards the distal end 154a and a second function is to provide part of the fixing mechanism. In this example, the support scaffold 170 has a central aperture 172 through which the protruding screw hole 168 passes on assembly of the head 30a and a screw, for example can be inserted to fix the two parts 150, 160 of the head together.

Figures 15a, 15b, 15c, 15d and 15e show a head 400 all features identical to those previously described have the same reference numerals. This head 400 has a reduced diameter compared with the handle 20. The slots 102 extend longitudinally from the first end 32 to the second end 236, however the slots could be curved as described with respect to Figures 7a and 7b.

Internal of the head 400, within the cavity 418 formed within the head 400, an internal sock 420 is provided. This sock 420 is a mesh formed from a metal wire. The sock 420 can be in the knitted form 426 shown in Figure 15b. Alternatively as shown in Figures 16a and 16b the sock 420 is a tube 424 formed from a woven mesh 422 having generally square apertures. The sock 420 diffuses the fluid flowing in the cavity 418 within the head 400 and slows down the longitudinal velocity of the flow. This results in more even wrapping of hair around the head 400 as the direction of fluid exiting the head 400 is more normal to the slots 102. The sock 420 extends along the length of the slots 102 within the head 400. The size of the apertures in the mesh is important; if they are too small the flow becomes too restricted and there is an increased chance of them clogging over time. An aperture size of around 1.6mm has been found to provide the benefit without undue restriction.

Figures 10a, 10b, 1 la-1 lc and 12 show various views of another head 300 which has a directed fluid flow. The head 300 has a first cylindrical part 310 and a second triangular part 330 that together form the fluid outlet 320. The first cylindrical part 310 has a first end 312 for connection to a handle 20 via a collar 328 and extends longitudinally to a second end 314 which comprises an end wall 316. An inner cavity 318 is formed within the first cylindrical part 310. The first cylindrical part 310 has an aperture 322 extending from the collar 328 to the second end 314. The aperture 322 is defined by a first edge 324 and a second edge 326.

The second triangular part 330 has a first end 332 and a second end 334 and if formed from a first side 336, a second side 338 and an internal wall 340. The second triangular part 330 fits within the aperture 322 and extends outwardly beyond the first cylindrical part 310.

The second triangular part 330 is movable relative to the first cylindrical part 310. In this example, the second triangular part 330 is fixed with respect to the handle 20 and the first cylindrical part 310 is moveable relative to both the second triangular part 30 and the handle 20. This enables the outlet slot 342 to be partially defined by one or the other of the first edge 324 and the second edge 326.

In one position, referring now to Figures 12a and 12b, the first edge 324 along with a first side 336 of the second triangular part 330 define the limits of the outlet slot 342.

The second triangular part 330 moves with respect to the first cylindrical part 310 so the outlet slot 342 is alternatively defined by the second edge 326 and the second side 338 as shown in Figures 13a and 13b. The second triangular part 330 rotates with respect to the first cylindrical part 310 in order to change the position of the outlet slot 342. The first cylindrical part 310 is temporarily retained in a position by the use of a detent mechanism.

The end wall 316 of the first cylindrical part 310 includes a first recess 340 and a second recess 350 each of which adapted to partially accommodate a ball bearing 360. The ball bearing 360 is biased towards the end wall 316 by a spring 362 (see Figure 1 lb). There are a number of suitable alternatives that could be used instead of this method of retaining one part with respect to the other part such as a plastic bump feature or a piece of sprung metal. Referring now to Figures 12a and 12b, when the second triangular part 330 is in a first position with respect to the first cylindrical part 310, the outlet slot 342 is formed from first side 336 and first edge 324 and the ball bearing 360 is accommodated by the first recess. By manually rotating the second triangular part 330 with respect to the first cylindrical part 310 the force of the spring 362 retaining the ball bearing 360 within the first recess 340 is overcome and the second triangular part 330 can be rotated with respect to the first cylindrical part 310 to move the ball bearing 360 into the second recess 350 and changing the position of the outlet slot 328 so it is now formed from the second edge 326 and the second side 338. The first cylindrical part 310 includes bristles 350 arranged in this example in parallel rows 352 on either side of the aperture 322. The rows 352 of bristles 350 extend from near the outlet slot 342 around the head 300 but in this example the bristles 350 do not extend all the way around the head 300, there is a gap in the rows 352 diametrically opposite the outlet slot 320.

Referring now to Figure 14, when hair 354 is being styled, the action of drawing the bristles 350 down through the hair 354 opens the outlet slot 342 on the side next to the hair 354. The position of the outlet slot 342 is movable by hand or by the friction or force of combing through the hair.

The use of a combination of a directed outlet slot 342 and bristles 350 means that the hair is dried and/or styled more quickly than conventionally as the fluid exiting from the outlet slot 342 is blown down the hair 354. The fluid exiting the outlet slot 342 is attracted to the surface of the second triangular part 330 which in turn attracts the hair 354 to the second triangular part 330. The bristles 350 separate and detangle individual strands of the hair 354 and this combination gives fast drying and a smother result. In use as shown in Figure 14, this head is designed to be pulled through the hair with the slot 328 adjacent the hair 354. Fluid is blown out of the slot 328 as the appliance is moved along the hair 354 so the hair is both heated and brushed. Having the slot 328 on either side of the head 356 means that the same head 300 can be used for both sides of the head and both the underside and the topside of the hair 354.

In each of the examples given, the head 30, 130, 180, 230, 300 in connected to handle 20 via a collar and a twist lock joint. Referring to Figure 7b, three protrusions 234 are provided on the internal surface of the collar 232 (one not shown). The protrusions 234 are adapted to engage a slot 90 (see Figure lb) or three separate slots provided near the distal end 22 of the handle 20. The slot 90 extends at least partially around an outer surface of the inner wall 60 and is helical so both a rotational and longitudinal movement is required to attach or remove the head from the handle 20. This is one example of a fixing mechanism, it will be apparent to the skilled person that other equally acceptable alternative mechanisms could be used.

The heads 30, 130, 180 and 230 described with respect to Figures 3a to 9 could be provided with bristles. For these heads 30, 130, 180 and 230 as the slots are arranged all the way around the head, any bristles would be arranged all the way around the head. An example would be to have one or more rows of bristles at least located on every other plate 110, 210.

The invention has been described in detail with respect to a hot styling brush however, it is applicable to any appliance that draws in a fluid and directs the outflow of that fluid from the appliance including a hairdryer.

The appliance can be used with or without a heater; the action of the outflow of fluid at high velocity has a drying effect. The heads have been described as being manufactured by attaching a first part to the second part using a screw however, as the skilled person will be aware, a number of different fixing methods can be used such as, but not limited to gluing or using ultrasonic welding.

The fluid that flows through the appliance is generally air, but may be a different combination of gases or gas and can include additives to improve performance of the appliance or the impact the appliance has on an object the output is directed at for example, hair and the styling of that hair. Such additives include but are not limited to hairspray and serums for example.

The heads 30, 130, 230 are all generally cylindrical in shape, however as the skilled person would realise, alternative shapes could be used such as ovals. The invention is not limited to the detailed description given above. Variations will be apparent to the person skilled in the art.