GB2503684A

GB2503684A - A nozzle for a hairdryer

Info

Publication number: GB2503684A
Application number: GB1211830.3A
Authority: GB
Inventors: Stephen Benjamin Courtney; Patrick Joseph William Moloney; Edward Shelton; Thomas James Dunning Follows
Original assignee: Dyson Technology Ltd
Current assignee: Dyson Technology Ltd
Priority date: 2012-07-04
Filing date: 2012-07-04
Publication date: 2014-01-08
Anticipated expiration: 2032-07-04
Also published as: GB201211830D0; GB2503684B

Abstract

A hairdryer comprises a handle 204, a body 202 comprising a fluid flow path 280 extending from a fluid inlet 270 to the fluid outlet 290, and a primary heated fluid flow path 260 extending from a primary fluid inlet 222 to the primary fluid outlet 230. A nozzle 300 is attachable to the body 202, the nozzle comprising a primary nozzle fluid inlet 320 for receiving the primary fluid flow from the primary fluid outlet 230, and a primary nozzle fluid outlet 330 for emitting the primary fluid flow from the nozzle 300. A further nozzle fluid inlet 370 is also provided for receiving the fluid flow from the fluid outlet 290, a further nozzle fluid outlet 390 also being provided in the nozzle for emitting the fluid flow. Within the nozzle 300 the fluid flow is isolated from the primary fluid flow.

Description

I

Attachment For A Hand Held Aimliance This invention relates to an attachment for a hand held appliance, in particular an attachment for a hairdryer and an appliance, particularly a hairdryer comprising such an attachment.

Blowers and in particular hot air blowers are used for a variety of applications such as drying substances such as paint or hair and cleaning or stripping surface layers.

Generally, a motor and fan are provided which draw fluid into a body; the fluid may be heated prior to exiting the body. The motor is susceptible to damage flxm foreign objects such as dirt or hair so conventionally a filter is provided at the fluid intake end of the blower. Conventionally such appliances are provided with a nozzle which can be attached and detached from the appliance and changes the shape and velocity of fluid flow that exits the appliance. Such nozzles can be used to focus the outflow of the appliance or to diffuse the outflow depending on the requirements of the user at that time.

According to a first aspect, the invention provides a hairdryer comprising a handle; a body comprising a fluid outlet and a primary fluid outlet; a fhn unit for gcncrating fluid flow through thc hairdrycr, thc hairdrycr comprising a fluid flow path cxtcnding from a fluid inlet through which a fluid flow enters the hairdryer to the fluid outleI and a primary fluid flow path extending from a primary fluid inlet to the primary fluid outlet; aheaterforheafingaprimaryfluidflowdrawnthmughtheprimaiyfluidinletanda nozzle attachable to the body, the nozzle comprising a primary nozzle fluid inlet for receivingtheprimaryfluidflowfromtheprimaryfluidoutlet,andaprimarynozzle fluid outlet for emitting the primary fluid flow, a further nozzle fluid inlet for receiving the fluid flow from the fluid outlet, a further nozzle fluid outlet for emitting the fluid flow, and wherein within the nozzle the fluid flow is isolated flxm the primary fluid flow.

The hairdryer has a primary flow which is that processed by and drawn into the appliance by the fan unit and a fluid flow which is entrained by the primary, processed flow. Thus the fluid flow through the hairdryer is amplified by the entrained flow.

Preferably, one of the further nozzle fluid outlet and the primary nozzle fluid outlet extends about the other of the further nozzle fluid outlet and the primary nozzle fluid outlet.

It is preferred that the further nozzle fluid outlet and the primary nozzle fluid outlet are located on opposing sides of the nozzle.

Preferably, the further nozzle fluid outlet and the primary nozzle fluid outlet are substantially coplanar.

It is preferred that the nozzle comprises a further fluid flow path for conveying the fluid flow to the further fluid outlet, and wherein the primary fluid inlet extends at least partially about the further fluid flow path.

Preferably, the primary fluid inlet surrounds the further fluid flow path.

It is preferred that the nozzle comprises a first end and a second end remote from the first end, and wherein the second end of the nozzle comprises at least the further nozzle fluid outlet.

Preferably, the second end of the nozzle compriscs the primary nozzle fluid outlet.

It is preferred that the primary nozzle fluid outlet is located between the first end and the second end of the nozzle.

Preferably, the second end of the nozzle is dcformablc.

It is preferred that the first end of the nozzle comprises the further nozzle fluid inlet.

Preferably, the first end of the nozzle is insertable into the fluid flow path through the fluid outlet.

It is preferred that the first end of the nozzle is slidably insertable into the fluid flow path through the fluid outlet.

Preferably, the nozzle is retained within the duct by means of friction between the nozzle and the body.

It is prcferrcd that thc primary fluid outict is configurcd to cmit thc primary fluid flow into the primary nozzle fluid flow path, and wherein the primary nozzle fluid inlet is located between the first end and the second end of the nozzle.

Preferably, the nozzle comprises a side wall between the first end and the socond end, and wherein a portion of the side wall which is located between the first end and the second end of the nozzle at least partially defines the primary nozzle fluid inlet.

It is preferred that the side wall is tubular in shape.

Preferably, the side wall cxtends about an inncr wall, and wherein the primary nozzlc fluid inlet is located between the inner wall and the side wall.

It is prcfcrrcd that thc inner wall is tubular in shapc.

Preferably, the side wall extends from the first end to the second end, and the nozzle comprises an outer wall extending at least partially about the side wall, and wherein the primary nozzle fluid inlet is located between the outer wall and the side wall.

It is preferred that the outer wall is tubular in shape.

According to a second aspect, the invention provides a nozzle for a hairdryer comprising a handle; a body comprising a fluid outlet and a primary fluid outlet; a fan unit for generating fluid flow through the hairdryer; a fluid flow path extending from a fluid inlet through which a fluid flow enters the hairdryer to the fluid outlet, and a primary fluid flow path extending from a primary fluid inlet to the primary fluid outlet; and a heater for heating a primary fluid flow drawn through the primary fluid inlet; wherein the nozzle is attachable to the body, the nozzle comprising a primary nozzle fluid inlet for receiving the primary fluid flow from the primary fluid outlet, and a primary nozzle fluid outlet for emitting the primary fluid flow, a further nozzle fluid inlet for receiving the fluid flow from the fluid outlet, a further nozzle fluid outlet for emitting the first fluid flow, a primary nozzle fluid inlet for receiving the primary fluid flow from the primary fluid outlet, and a primary nozzle fluid outlet for emitting the primary fluid flow, and wherein within the nozzle the fluid flow is isolated from the primary fluid flow Preferably, one of the further nozzle fluid outlet and the primary nozzle fluid outlet extends about the other of the further nozzle fluid outlet and the primary nozzle fluid outlet.

It is prefened that the further nozzle fluid outlet and the primary nozzle fluid outlet are located on opposing sides of the nozzle.

It is prefened that the nozzle comprises a further fluid flow path for conveying the further fluid flow to the further fluid outlet, and wherein the primary fluid inlet extends at least partially about the further fluid flow path.

Preferably, the primary fluid inlet surrounds the further fluid flow path.

It is preferred that the nozzle comprises a first end and a second end remote flt,m the first end, and wherein the second end of the nozzle comprises at least the further nozzle fluid outlet.

Preferably, the second end of the nozzle comprises the primary nozzle fluid outlet.

Preferably, the second end of the nozzle is deformable.

It is prefrrred that the first end of the nozzle comprises the further nozzle fluid inlet Preferably, the primary nozzle fluid inlet is located between the first end and the second end of the nozzle.

It is preferred that the nozzle comprises a side wall between the first end and the second end, and wherein a portion of the side wall which is located between the first end and the second end of the nozzle at least partially defines the primary nozzle fluid inle Preferably, the side wall is tubular in shape.

It is preferred that the side wall extends about an inner wall, and wherein the primary nozzle fluid inlet is located between the inner wall and the side wall.

Preferably, the inner wall is tubular in shape.

It is preferred that the side wall extends fmm the first end to the second end, and the nozzle comprises an outer wall extending at least partially about the side wall, and wherein the primary nozzle fluid inlet is located between the outer wall and the side wall Preferably, the outer wall is tubular in shape.

Preferably, said at least one parameter of the fluid flow emitted from the hairdryer comprises at least one of the shape, profile, orientation, direction, flow rate and velocity of the fluid flow emitted from the hairdryer.

The invention will now be described by way of example and with reference to the accompanying drawings, of which: Figures Ia to if show various representations of a double flow path nozzle according to the invention Figure 2a to 2c show a double flow path nozzle attached to a hairdryer; Figures 3a to 3f show a laminar flow nozzle; Figures 4a to 4f show a further double flow path nozzle; Figures 4g to 4j show thc further double flow path nozzle attached to a hairdryer; Figure 5a shows an alternate double flow path nozzle; and Figures Sb to Sg show an alternate double flow path nozzle.

Figures Ia to if show a double flow path nozzle 300 and Figures 2a to 2c show the nozzle 300 attached to a double flow path hairdryer 200. The nozzle 300 comprises a generally tubular body 310 having an outer wall 312 and an inner wall 382. The outer wall 312 extends from an upstream end 300a to a downstream end 300b of the nozzle 300 and about the inner wall 382. The outer wall 312 has an aperture which forms a fluid inlet 320 and a fluid outlet 330 is provided downstream of the fluid inlet 320. In use, fluid flows into the fluid inlet 320 along the length of the body 310 along fluid flow path 360 provided between the outer wall 312 and the inner wall 382 and out through the fluid outlet 330. The inner wall 382 is generally tubular however, at the fluid inlet 320 it curves outwards 322 and joins the outer wall 312 forming an upstream end to the fluid inlet 320.

A further inlet 370 is provided in the upstream end 300a of the nozzle 300 and fluid flows along a further fluid flow path 380 to further fluid outlet 390. The further fluid flow path 380 flows within a tube defined by the inner wall 382. The further fluid flow path 380 is nested within the fluid flow path 360 and surrounded by the fluid flow path 360. The fluid outlet 330 and thrther fluid outlet 390 have substantially the same shape and configuration and in this example, comprise a rounded slot with a central wider region. This means that fluid flow is directed mainly in the central region but that the drying area is increased by the slot portion.

The fluid outlet 330 and the further fluid outlet 390 can comprise alternative shapes such as a simple double slot 330a, 390a as is shown in Figure 1g.

In use, when thc nozzle is attached to a hairdrycr thc fluid inlet is in fluid eornmunication with a primary fluid outlct of the hairdiyer and the further fluid inlet is in fluid comnunication with a second fluid outlet of the hairdryer. Having two fluid flow paths is advantageous as it enables manipulation of the fluid outflow to create different styling conditions depending on user requirements.

Refening now to Figures 2a to 2c, in particular the hairdryer 200 will now be described.

The hairdryer 200 has a handle 204, 206 and a body 202 which comprises a duct 282, 284. A primary fluid flow path 260 starts at a primary inlet 220 which in this example is located at the upstream end 200a of the hairdryer i.e. at the distal end of the hairdryer from the fluid outlet 200b. Fluid is drawn into the primary fluid inlet 220 by a fan unit 250, fluid flows along primary fluid flow path 260 located on the inside of the outer body 202 of the hairdryer between the outer body 202 and the duct 282, along a first hand'e portion 204 to the fan unit 250.

The fan unit 250 includes a fan and a motor. The fluid is drawn through the fan unit 250, along a second handle portion 206 and returns to the body 202 of the hairdryer in an inner tier 260a of the body. The inner tier 260a of the body 202 is nested within the primary fluid flow path 260 between the primary fluid flow path 260 and the duct 282 and includes a heater 208. The heater 208 is annular and heats the fluid that flows through the inner tier 260a directly. Downstream of the heater 208, fluid exits the primary fluid flow path at the primary outlet 230.

The nozzle 300 is inserted into the downstream end 200b of the hairdryer until a stop is reached. In this position, the fluid inlet 320 of the nozzle 300 is in fluid communication with a primary fluid outlet 230 of the hairdryer 200. Fluid that flows out of the primary outlet 230 flows along the body 310 of the nozzle 300 to the nozzle outlet 330. The nozzle is an attachment for adjusting at least one parameter of the fluid flow emitted from the hairdryer and the downstream end 300b of the nozzle protrudes from the downstream end 200b of the hairdryer 200.

A second fluid flow path 280 is also provided and travcls straight through thc body 202 of the hairdryer 200 from a second inlet 270 to a second outlet 290. With the double flow path nozzle 300 attached to the outlet end 200b of the hairdryer 200, both the primary and second fluids flow from their respective inlet 220, 270 to a nozzle outlet 330, 390. The fluid that flows through the second fluid flow path 280 is not processed by the fan unit 250; it is entrained by the primary fluid flow through the primary fluid flow path 260 when the fan unit is switched on.

The second fluid flow path 280 can be considered to flow along a tube defined by an upstream duct 282 and a downstream duct 284 where the primary outlet 230 is an aperture in the tube between the ducts 282 and 284. The nozzle is partially inserted into the tube defined by the ducts 284, 282. In this example the nozzle 300 is slidably inserted into hairdryer outlet 200b along downstream duct 284 past the aperture or primary fluid outlet 230 into the upstream duct 282. The nozzle 300 is retained in the duct 282, 284 by friction.

When nozzle 300 is attached to the hairdryer 200, fluid that flows through the primary fluid flow path 260 flows to the primary outlet 230 enters the inlet 320 of the nozzle 300, flows along the fluid flow path 360 between the outer wall 312 and the inner wall 382 to an outlet 330 of the nozzle 300 and appliance. Fluid that flows through the second fluid flow path 280 flows towards the second outlet 290, enters the further inlet 370 of the nozzle 300 and flows along further fluid flow path 380 within the inner wall 382 to the frirther outlet 390 of the nozzle 300.

In this embodiment, the thrther flow path 380 is central to and concentric with the fluid flow path 360 i.e. the fluid flow path extends about the further fluid flow path. The further outlet 390 is surrounded by the outlet 330 and this results in a central cool fluid path with an outer perimeter of hot fluid exiting the nozzle. In order that the integrity of the hot and cold fluid flow paths are maintained and that they are isolated within the hairdryer and nozzle, the inserted nozzle 300 must seal the primary fluid outlet 330 to prevent mixing of the hot and cold flows. In this example, the outer wall 312 is provided with an upstanding collar 312a that extends about the outer wall 312 and seals the duct 282 thus preventing ingress of fluid from the second fluid flow path 280 into the nozzle inlet 320 and egress from the primary fluid outlet 230 into the second fluid flow path 280. The collar 31 2a of outer wall 312 provides the friction between the nozzle and the hairdryer that retains the nozzle within the hairdryer.

A second collar 312b is provided downstream of the fluid inlet 320 and this seals the nozzle with respect to haiirdryer duet 284 and the hairdryer outlet 200b that surrounds the nozzle outlet 330. This is to stop leakage around the nozzle and to provide a more focused outflow from the nozzle.

The collars 312a, 312b in this example are formed from an 0-ring which is held in a recess formed in the body 310 of the nozzle. Alternatives will be apparent to the skilled person and includc, but arc not limited to an integral mouldcd lip, a plastic/hard rubbcr ring, a living hinge, an overmoulded lip and a push fit arrangement.

Whilst the hairdryer shown has the primary fluid flow path flowing through the handles of the hairdryer, this is not required. The primary fluid flow path can alternatively flow from the primary inlet 220 along the body 202 through the heater to the primary fluid outlet 230 and thence into the nozzle.

Figures 3a to 3f show various representations of a laminar nozzle according to the invcntion. A nozzle 400 has a body 410 with a gcncrally tubular outer wall 412, and an inner wall 424 which divides the body 410 substantially in half lengthways. The outer wall 412 has a inlet 420 through the wall 412 aM an outlet 430 downstream of the inlet and connected to the inlet 420 by a fluid flow path 460. The inlet 420 is a single semicircular aperture in the outer wall 412 and is defined by the outer wall 412, a side wall 422 and the inner wall 424. The inlet 420 is located between a downstream end 400b and an upstream end 400a of the nozzle 400. The side wall 422 connects between the outer wall 410 and the inner wall 424 and together with the outer wall 412 and the inner wall 424 defines the fluid flow path 460.

A further inlet 470 is provided in thc upstrcam cnd 400a of the nozzlc 400. In this example the thither inlet 470 is substantially circular to provide a fluid connection with substantially circular hairdryer ducting 284 (for example at the second fluid outlet 290 of Figurc 2a). Thc ffirthcr inlct 470 is in fluid communication with a furthcr outlet 490 via a furthcr fluid flow path 480.

In order to create a laminar flow out of the nozzle 400, the two outlets 430, 490 of the nozzle are situated one on top of the other or side by side depending on the orientation of the nozzle i.e. they are coplanar and locatod on opposing sides of the nozzle. The fluid flow path 460 and further fluid flow path 480 are also bilateral along the length of the nozzle from the inlet 420. Upstream of inlet 420, where there is only the further fluid flow path 480, the further fluid flow path 480 extends from a semicircular cross-scction to a circular cross-section at the further inlet 470. This change in shape is facilitated by the side wall 422 that forms part of the fluid inlet 420.

As the nozzle 400 provides fluid communication with an annular primary flow, the diameter of the further fluid flow path 480 at the fluid inlet 420 is reduced slightly enabling fluid that exits the primary outlet of the hairdryer radially spaced 420a away from the inlet 420 to flow around the circumference of the nozzle and into the inlet 420.

Without this feature, flow from the primary outlet would be restricted at the inlet.

In addition, a collar 412a is provided around the outer wall 412 at or near the upstream end of the fluid inlet 420 to seal the nozzle 400 against internal ducting 284 of a hairdryer to prevent any primary flow from a hairdryer mixing with entrained flow.

Figures 4a to 4j show a further double flow path nozzle 500 and the nozzle attached to a hairdryer 200. In this nozzle 500, the relative positions of the inlets and outlets are reversed producing an inside out nozzle.

The nozzle 500 has a generally tubular body 510 having a fluid inlet 520 through an outer wall 512 of the body 510 and a fluid outlet 530 downstream of the fluid inlet 520.

In use, fluid flows into the fluid inlet 520 along the length of the body 510 along fluid flow path 560 and out through the fluid outlet 530. A further inlet 570 is provided in the upstream end 500a of the nozzle 500 and fluid flows from this further inlet 570 along a further fluid flow path 580 to a further fluid outlet 590.

Refening now to Figures 4g to 4j, when the nozzle 500 is inserted into a hairdryer 200, the inlet 520 aligns with a primary fluid outlet 230 of the hairdryer. Thus, fluid flows in the hairdryer from the primary fluid inlet 220, through the primary flow path 260 past the fan unit 250 and heater 208 to a primary fluid outlet 230 then into the fluid inlet 520 of the nozzle 500 along fluid flow path 560 to fluid outlet 530.

The further inlet 570 of the nozzle 500 aligns with and is inserted into a second fluid outlet 290 of the hairdryer 200. Fluid that is drawn into thc hairdrycr along a second fluid flow path 280 by the action of the fan unit 250 on the primary fluid flow path 260 enters the hairdryer at a second fluid inlet 270, flows along a second fluid flow path 280 towards a second fluid outlet 290. The fluid in the second fluid flow path 280 enters the further nozzle inlet 570, flows along a further fluid flow path 580 to a further fluid outlet 590.

The fluid outlet 530 and further fluid outlet 590 are arranged so that the fluid from the primary fluid flow path 260 i.e. the fluid that has been processed by the fan unit 250 and heater by the heater 208 is surrounded by fluid from the second fluid flow path i.e. cool entrained fluid. Thus, the further outlet 590 surrounds the outlet 530 and this results in a central hot fluid path with an outer perimeter of cool fluid exiting the nozzle. In this example, the outlets 530, 590 of the nozzle 500 are slot shaped but they could be circular.

In order to achieve this, the further inlet 570 has a circular opening to match shape and size of the second fluid outlet 290, the further fluid flow path 580 is initially a pair of slots or a V-shaped channel 580a (Figures 4b, 4d, and 4f in particular) formed from the outcr wall 512 of the nozzle 500 and an inner wall 524 that divides the two fluid flow paths 560, 580 within the nozzle 500. Downstream of the fluid inlet 520, the inner wall 524 becomes circular and generally concentric to the outer wall 512 and the further fluid flow path 580 becomes annular in shape to form the radially outer outlet 590 of the nozzle 500 i.e. the further outlet 590 surrounds the fluid outlet 530.

Inlet 520 is annular and has a mouth 520a formed between the inner wall 524 and the outer wall 512 of the nozzle. The mouth 520a provides an entrance to the fluid flow path 560 which is generally circular within the body 510 of the nozzle 500 and surrounded by the further fluid flow path 580 downstream of the inlet 520.

Figures 5a to 5g show an alternate double flow path nozzle 700 on a hairdryer 200. The nozzle 700 has a generally tubular body 610, a first or upstream end 600a and a second or downstream end 600b. There isa fluid inlet 620 in an outer wall 612 ofthc body 610 between the first end 600a and the second end 600b of the nozzle 600 and a fluid outlet 630 downstream of the fluid inlet 620. In this example, the fluid outlet 630 is ring shaped or annular and is formed by an inner wall 614 of the nozzle 700 and the outer wall 612.

The fluid inlet 620 is an opening in the outer wall 612 of the nozzle and is defined by an aperture formed from a slanted edge 622b of the outer wall and a curved side wall 622 provided at the upstream end of the fluid inlet which connects the outer wall 612 and the inner wall 614. The slanted edge of the outer wall is slanted in the direction of fluid flow to reduce turbulence and pressure losses as the primary flow enters the nozzle.

The outer wall 612 surrounds inter wall 614 and together walls 612, 614 define a fluid flow path 660 through the generally tubular body 610 from the inlet 620 to the outlet 630. In the vicinity of the outlet 630, the inner wall curves outwards 614b and increases in diameter causing a reduction in the cross section of the fluid flow path at the outlet 630. The inter wall 614 continues beyond the outlet 630 and the end of the outer wall 612 of the nozzle 700 to a downstream nozzle end 600b. The inner wall 614b is convex and is a Coanda surface i.e. it causes fluid that flows through the fluid flow path 660 to hug the surface of the inner wall 614b as it curves forming an annular flow at the outlet 630 and downstream nozzle end 600b. In addition the Coanda surface 614 is arranged so a primary fluid flow exiting the outlet 630 is amplified by the Coanda effect.

The hairdiyer achieves the output and cooling effect described above with a nozzle which includes a Coanda surface to provide an ampli'ing region utilising the Coanda effect. A Coanda surface is a known type of surface over which fluid flow exiting an output orifice close to the surface exhibits the Coanda effect. The fluid tends to flow over the surface closely, almost clinging to' or hugging' the surface. The Coanda effect is already a proven, well documented method of entrainment whereby a primary air flow is directed over the Coanda surface. A description of the features of a Coanda surface, and the effect of fluid flow over a Coanda surface, can be found in articles such as Reba, Scientific American, Volume 214, June 1963 pages 84 to 92.

Advantageously, the assembly results in the entrainment of air surrounding the mouth of the nozzle such that the primary air flow is amplified by at least 15%, whilst a smooth overall output is maintained By encouraging the fluid at the outlet 630 to flow along 616 the curved surface 614b of the inner wall to the downstream nozzle end 600b, fluid is entrained 618 from outside the hairdryer 200 (Figure 5c) by the Coanda effect. This action of entrainment increases the flow of air at the downstream nozzle end 600b, thus the volume of fluid flowing at the downstream nozzle end 600b is magnified by the entrathment above what is processed by the hairdryer 200 through a fan unit 250 and heater 208.

When the nozzle 700 is attached to a hairdryer 200 as shown in Figure 5a, the fluid inlet 620 aligns with a primary fluid outlet 230 of the hairdryer. Hairdryer 200 has a second fluid flow path 280 through a central duct 282 and this second fluid flow path 280 is in fluid communication with a further fluid flow path 780 provided in the nozzle 700. The inner wall 714 comprises a tube or bore through the nozzle 700 through which a fluid can flow from a further inlet 770 to a further outlet 790 along a further fluid flow path 780. In this examplc, adjacent to and upstream of the fluid outlet 630 the inner wall 714 splits into an outer curved wall 714b along which fluid from the fluid flow path 660 flows to fluid outlet 630 and an inner straight wall 714a which continues to a further fluid outlet 790.

In order to seal the nozzle fluid flow path 660 with respect to the primaty fluid outlet 230, the outer wall 612 of the nozzle is provided with a collar 612a. The collar 612a is upstanding from the outer wall 612 so has a larger diameter than the outer wall and is designed to fit with dueting 282 within the hairdiyer 200. The collar 61 2a is upstream of the fluid inlet 620 of the nozzle 700. A second collar 612b is ideally also provided downstream of the fluid inlet 620 and prevents fluid from the primary outlet 230 of the hairdryer flowing between the outer wall 612 of the nozzle and the hairdryer outlet 2 OOb.

When the nozzle 700 is attached to a hairdryer a primary flow from a primary inlet 220 to a primary outlet 230 along a primary flow path 260 is in fluid communication with the nozzle inlet 620. Fluid flows from the nozzle inlet 620 along fluid flow path 660 to nozzle outlet 630. As the surface of the outer curved wall 714b is a Coanda surface, fluid that flows out of the outlet 630 is drawn to the surface and amplified by the Coanda effect which entrains fluid 618 from outside of the nozzle along the nozzle to a nozzle end 600b. In addition, a second fluid flow path 280 is provided in the hairdryer through which fluid is entrained by the action of fluid flowing in the primary fluid flow path 260,660 i.e. fluid that is drawn into the primary fluid flow path 260 directly by the fan unit 250. This second fluid flow path 280 has an inlet 270 and an outlet 290.

The outlet 290 is in fluid communication with the further inlet 770 of the nozzle 700.

So fluid that is entrained into the second fluid flow path 280 by the action of the fan unit 250 flows along a fhrther fluid flow path 780 the boundaries of which are defined by the inner wall 714, 714b of the nozzle 700 to a further outlet 790.

Thus, in this example the hairdryer emits a hot annular fluid which has a central cool core from the internally entrained fluid and an outer cool ring from the externally entrained fluid.

The nozzle is retained with respect to the hairdryer by one of a number of alternatives which include but are not limited to a felt seal, a bump stop, an 0-ring, magnets, friction fit, a mechanical clip, snap fit or actuated snap fit.

The hairdryers are preferably provided with a filter 222 (Figures 2b and 2c) which covers at least the primary fluid flow inlet 220 of the hairdrycr. The filter 222 is provided as is prevents ingress of dust, debris and hair into the primary fluid flow path upstream 260 of the fan unit250 which includes a fan and a motor. These foreign objects could damage the motor and cause premature failure of the hairdryer. The filter 222 can cover the entire intake of the hairdryer i.e. both the primary fluid flow path 260 and the second fluid flow path 280 however this is not preferred as it interferes with a line of sight thmugh the appliance. A line of sight through the appliance is restricted by the use of a nozzle on the appliance.

The invention has been described in detail with respect to a nozzle for a hairdryer and a hairdryer comprising a nozzle however, it is applicable to any appliance that draws in a fluid and directs the outflow of that fluid fiDm the appliance.

The appliance can be used with or without a heateç the action of the outflow of fluid at high velocity has a drying effect.

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.

The invention is not limited to the detailed description given above. Variations will be apparent to the person skilled in the art.

Claims

CLAIMS1. A hairdryer comprising a handle; a body comprising a fluid outlet and a primary fluid outlet; a fan unit for generating fluid flow through the hairdryer, the hairdryer comprising a fluid flow path extending from a fluid inlet through which a fluid flow enters the hairdryer to the fluid outlet, and a primary fluid flow path extending from a primary fluid inlet to the primary fluid outlet; a heater for heating a primary fluid flow drawn through thc primary fluid inlet; and a nozzle attachable to the body, the nozzle comprising a primary nozzle fluid inlet for receiving the primary fluid flow from the primary fluid outlet, and a primary nozzle fluid outlet for emitting the primary fluid flow, a further nozzle fluid inlet for reeciving the fluid flow from the fluid outlet, a further nozzle fluid outlet for emitting the fluid flow, and wherein within the nozzle the fluid flow is isolated from the primary fluid flow.
2. A hairdryer according to claim 1, wherein one of the further nozzle fluid outlet and the primary nozzle fluid outlet extends about the other of the further nozzle fluid outlet and the primary nozzle fluid outlet.
3. A hairdryer according to claim 1, wherein the further nozzle fluid outlet and the primary nozzle fluid outlet are located on opposing sides of the nozzle.
4. A hairdryer according to any preceding claim, wherein the further nozzle fluid outlet and the primary nozzle fluid outlet are substantially coplanar.
5. A hairdryer according to any preceding claim, wherein the nozzle comprises a further fluid flow path for conveying the fluid flow to the further fluid outlet, and wherein the primary fluid inlet extends at least partially about the further fluid flow path.
6. A hairdryer according to claim 5, wherein the primary fluid inlet surrounds the further fluid flow path.
7. A hairdryer according to any preceding claim, wherein the nozzle comprises a ste dandas ondendremotefromtheflrstend,andwhereinthesecondendofthe nozzle comprises at least the further nozzle fluid outlet.
8. A hairdryer according to claim 7, wherein the second end of the nozzle comprises the primary nozzle fluid outlet.
9. A hairdryer according to claim 7, wherein the primary nozzle fluid outlet is located between the first end and the second end of the nozzle.
10. A hairdryer according to any of claims 7 to 9, wherein the second end of the nozzle is deformable.
11. Ahairdryeraccordingto anyofclaims7to 10,whereinthe flrstendofthe nozzle comprises the fUrther nozzle fluid inlet
12. A hairdryer according to any of claims 7 to 11, wherein the first end of the nozzle is insertable into the fluid flow path through thc fluid outlet.
13. A hairdryer according to claim 12, wherein the first end of the nozzle is slidably insertable into the fluid flow path through the fluid outlet.
14. A hairdryer according to claim 12 or claim 13, wherein the nozzle is retained within the duct by means of friction between the nozzle and the body.
15. A hairdryer according to any of claims 7 to 14, wherein the primary fluid outlet is configured to emit the primary fluid flow into the primary nozzle fluid flow path, and wherein the primary nozzle fluid inlet is located between the first end and the second end of the nozzle.
16. A hairdryer according to claim 15, wherein the nozzle comprises a side wall between the first end and the second end, and wherein a portion of the side wall which is located between the first end and the second end of the nozzle at least partially defines the primary nozzle fluid inlet.
17. A hairdryer according to claim 16, wherein the side wall is tubular in shape.
18. A hairdryer according to claim 16 or claim 17, wherein the side wall extends about an inner wall, and wherein the primary nozzle fluid inlet is located between the inner wall and the side wall.
19. A hairdryer according to claim 18, wherein the inner wall is tubular in shape.
20. A hairdryer according to claim 16 or claim 17, wherein the side wall extends from the fir st end to the second end, and the nozzle comprises an outer wall extending at least partially about the side wall, and wherein the primary nozzle fluid inlet is located between the outer wall and the side wall.
21. A hairdrycr according to claim 20, whcrcin thc outcr wall is tubular in shape.
22. A nozzle for a hairdryer comprising a handle; a body comprising a fluid outlet and a primary fluid outlet; a fan unit for generating fluid flow through the hairdryer; a fluid flow path extending from a fluid inlet through which a fluid flow enters the hairdryer to the fluid outlet, and a primary fluid flow path extending from a primary fluid inlet to the primary fluid outlet; and a heater for heating a primary fluid flow drawn through the primary fluid inlet; wherein the nozzle is attachable to the body, the nozzle comprising a primary nozzle fluid inlet for receiving the primary fluid flow from the primary fluid outlet, and a primary nozzle fluid outlet for emitting the primary fluid flow, a further nozzle fluid inlet for receiving the fluid flow from the fluid outlet, a further nozzle fluid outlet for emitting the first fluid flow, and wherein within the nozzc thc fluid flow is isolatcd from the primary fluid flow.
23. A nozzle according to claim 22, wherein one of the further nozzle fluid outlet and the primary nozzle fluid outlet extends about the other of the further nozzle fluid outlet and the primary nozzle fluid outlet.
24. A nozzle according to claim 22, wherein the further nozzle fluid outlet and the primary nozzle fluid outlet are located on opposing sides of the nozzle.
25. A nozzle accordillg to any of claims 22 to 24, wherein the further nozzle fluid outlet and the primary nozzle fluid outlet are substantially coplanar.
26. A nozzle according to any of claims 22 to 25, comprising a further fluid flow path for conveying the further fluid flow to the further fluid outlet, and wherein the primary fluid inlet extends at least partially about the further fluid flow path.
27. A nozzle according to claim 26, wherein the primary fluid inlet surrounds the further fluid flow path.
28. A nozzle accordillg to any of claims 22 to 27, comprising a first elld and a second end remote from the first end, and wherein the second end of the nozzle compriscs at least the flirthcr nozzle fluid outlet.
29. A nozzle according to claim 2, wherein the second end of the nozzle comprises the primary nozzle fluid outlet.
30. A nozzle according to claim 29, wherein the primary nozzle fluid outlet is located between the first end and the second end of the nozzle.31 A nozzle according to any of claims 28 to 30, wherein the second end of the nozzle is deformable.32. A nozzle according to any of claims 28 to 31, wherein the first end of the nozzle comprises the further nozzle fluid inlet.33. A nozzle according to any of claims 28 to 32, wherein the primary nozzle fluid inlet is located between the first end and the second end of the nozzle.34. A nozzle according to claim 33, comprising a side wall between the first end and the second end, and wherein a portion of the side wall which is located between the first end and the second end of the nozzle at least partially defines the primary nozzle fluid inlet.35. A nozzle according to claim 34 wherein the side wall is tubular in shape.36. A nozzle according to claim 34 or claim 35, wherein the side wall extends about an inner wall, and wherein the primary nozzle fluid inlet is located between the inner wall and the side wall.37. A nozzle according to claim 36, wherein the inner wall is tubular in shape.38. A nozzle according to claim 34 or claim 35, wherein the side wall extends from the first end to the second end, and the nozzle comprises an outer wall extending at least partially about the side wall, and wherein the primary nozzle fluid inlet is located between the outer wall and the side wall.39. A nozzle according to claim 38, wherein the outer wall is tubular in shape.