GB2503685A

GB2503685A - A nozzle for a hairdryer

Info

Publication number: GB2503685A
Application number: GB1211831.1A
Authority: GB
Inventors: Stephen Benjamin Courtney; Patrick Joseph William Moloney; Edward Shelton
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: GB2503685B; GB201211831D0

Abstract

A hairdryer 120 comprises an attachment such as a nozzle 100 partially insertable into the end of a duct (123, fig.1c). The attachment 100 at least partially defines at least one aperture 150 for emitting fluid flow when the attachment is located in the duct (123, fig. 1c). The attachment has an external surface 110 located downstream from said at least one aperture 150, and over which fluid emitted from said at least one aperture 150 is directed. The external surface of the attachment is preferably convex in shape and may comprise a Coanda surface, which acts to entrain extra fluid from outside the nozzle into the flow, thus amplifying the fluid flow. A collar (350, fig. 2d) may be provided to define, together with the outer surface of the nozzle (310, fig. 2d) a flow path for the entrained fluid.

Description

I

An Attachment For A Hand Held Annilance 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 from 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 invcntion provides a hairdryer comprising a handle; a body comprising a duct; a fan unit for generating a fluid flow from a fluid inlct through which the fluid flow enters the hairdryer to an end of the duct for emitting the fluid flow from the body; and an attachment partially insertable into the end of the duct and which at least partially defines at least one aperture for emitting the fluid flow when the attachment is located in the duct, and whettin the attachment has an external surface located downstream from said at least one aperture and over which fluid emitted from said at least one aperture is directed.

Preferably, the external surface of the attachment at least partially defines said at least one aperture.

It is preferred that the external surface of the attachment is convex in shape.

Preferably, the external surface of the attachment comprises a Coanda surface.

It is preferred that a front portion of the external surface of the attachment tapers towards a longitudinal axis of the nozzle.

Preferably, the front portion of the external surface of the attachment tapers to a point.

It is preferred that the aftachment comprises a collar at least partially surrounding the external surface, and wherein the internal surface of the collar and the external surface define an external fluid flow path through which fluid from outside the hairdryer is drawn by fluid emitted from said at least one aperture.

Preferably, said at least one aperture is located between the internal surface of the duct and the external surface of the attachment.

It is preferred that the body comprises a fluid outlet for emitting the fluid flow into the duct, and wherein the attachment comprises a fluid inlet for receiving the fluid flow from the fluid outlet, and a fluid flow path extending from the fluid inlet to said at least one aperture.

Preferably, the attachment comprises a first end which is insertable within the duct, and a second end remote from the first end, and wherein the fluid inlet is located between the first end and the second end of the attachment.

It is preferred that the fluid inlet comprises at least one aperture extending at least partially about the longitudinal axis of the attachment.

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

Preferably, the attachment comprises an outer wall extending about an inner wall which at least partially defines the fluid flow path. It is preferred that the inner wall is tubular in shape.

It is preferred that the external surface of the attachment extends about the inner wall.

Preferably, the inner wall is open at each end, and wherein a fluid flow is drawn through the duct and the inner wall by the fluid flow emitted from said at least one aperture.

In one embodiment, the attachment comprises a first side wall extending from the first end to the second end, and a second side wall extending at least partially about the first side wall, and wherein the fluid flow path is located between the side walls.

Preferably, each of the first and second side walls is tubular in shape. It is preferred that the external surface of the attachment extends about the first side wall.

Preferably, thc first sidc wall is opcn at cach end, and wherein a fluid flow is drawn through the duct and the first side wall by the fluid flow emitted from said at least one aperture.

The invention will now be described by way of example and with reference to the accompanying drawings, of which: Figures Ia to Ic show a single flow path nozzle attached to a hairdrycr; Figures 2a to 2e show a double flow path nozzle attached to a hairdryer; Figure 3a shows an alternate single flow path nozzle attached to a hairdryer; Figures 3b to 3g show an alternate single flow path nozzle; Figure 4a shows an alternate double flow path nozzle; Figures 4b to 4g show an alternate double flow path nozzle; and Figures 5a to Se show a further single flow path nozzle.

Figures la to ic show a nozzle 100 attached to a conventional hairdrycr 120.

The hairdryer 120 has a body 122 and a handle 124. The body 122 includes a duct 123 that houses a fan unit 130 and a heater 140 and a fluid flow path 126 is provided from an inlet 128 located at the upstream end I 20a of the hairdrycr to an outlet 132 provided at a downstream end 120b of the hairdryer. In use, fluid is drawn through the fluid flow path 126 by the fan unit 130 from the inlet 128 to the outlet 132. When there is no attachment, the hairdryer outlet 132 is circular.

The nozzle 100 has an upstream end lOOa which is inserted into duct 123 at the outlet 132 of the hairdryer 120 and a downstream end lOOb which protrudes from the outlet 132 of the hairdryer 120. The nozzle 100 has a convex outer surface 110 which curves inwards to a rounded point or dome at the upstream end I OOa of the nozzle and at the downstream end lOOb of the nozzle. The convex outer surface 110 of the nozzle together with the hairdrycr outlet 132 define an annular fluid outlet or aperture 150 of the hairdryer at the downstream end 120b of the hairdryer.

In the vicinity of the outlet 150, the convex outer wall 110 curves outwards and increases in diameter causing a reduction in the cross section of the fluid flow path at the outlet 150. The convex outer wall 110 continues beyond the outlet 150 and the downstream end I 20b of the hairdryer to a downstream nozzle end I OOb. The convex outer wall 110 is a Coanda surface i.e. it causes fluid that flows through the fluid flow path 126 to hug thc surfacc of thc outcr wall 110 as it curvcs forming an annular flow at the outlet 150 and downstream nozzle end bob. In addition the Coanda surface 110 is arranged so a fluid flow exiting the outlet 150 is amplified by 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 cffcct of fluid flow over a Coanda surface, can bc found in articles such as Reba, Scientific American, Volume 214, Julle 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. The hairdryer achieves the output and cooling effect described above with a nozzle which includes a Coanda surface to provide an amplifying region utilising the Coanda effect.

By cncouraging the fluid at thc outlet 150 to flow along the curvcd surfacc 110 of the outer wall to the downstream nozzle end bOb, fluid is entrained 118 from outside the hairdryer 120 (Figures lb and Ic) by the Coanda effect. This action of entrainment increases the flow of air at the downstream nozzle end bob, thus the volume of fluid flowing at the downstrcam nozzle cnd lOOb is magnified by thc entrainmcnt abovc what is processed by thc hairdrycr 120 through a fan unit 130 and hcatcr 140.

The entrainment provides an advantage as it results in the production of an annular ring of hot fluid which is surrounded by and the outer edges are partially cooled by the entrained cool fluid.

The nozzle 100 is retained within the hairdryer outlet 132 by one of a number of methods such as providing a ring around the outer surface and attached thereto by a number of radiafly spaced struts, thc ring engaging with the duct 122 when thc nozzle is partially inserted in the hairdryer outlet 132. An alternative retention method is to use a central strut to support the nozzle.

Figures 2a to 2c show an alternate nozzle 300 attached to a conventional hairdryer 120.

Features that have already been described with respect to Figures la and lb are provided with the same reference numerals.

The nozzle 300 is provided with a collar 350 which surrounds the outer surface 310.

The internal surface 352 of the collar 350 and the outer surface 310 of the nozzle together define an entrained fluid flow path 354 through which fluid 318 that has been entrained from outside the hairdryer 120 by the action of the fan unit 130 drawing a fluid flow through the hairdryer to the annular outlet 360 formed by the convex outer surface 310 of the nozzle and the hairdryer outlet 132 can flow.

The collar 350 has two portions, an upstream portion 356 which flares outwards and away from the body 122 of the hairdryer and a downstream portion 358 which is generally constant in diameter and follows the line of the convex outer surface 310 of the nozzle 300. The flarcd end 356 is to increase the entrainment effect and the volumc of fluid that flows through thc cntraincd fluid flow path 354. The downstrcam end 358 focuses the flow towards the Coanda surface namely the outer surface 310 of the nozzle to provide a focused ring of fluid output from the end of the nozzle.

The entrained fluid 318 and fluid flow from the hairdrycr fluid flow path 126 mix and combine at the downstream end 120b of the hairdryer and within the collar 350.

The collar 350 additional ly provides a finger guard to prevent a person from touching the outlet 132 directly and the entrained flow 318 cools the surface of the collar 350 preventing the collar 350 getting hot.

Figures 3b to 3g show an alternate single flow path nozzle 600 having a generally tubular body 610, a first or upstream end 600a and a second or downstream end 600b.

There is a fluid inlet 620 in an outer wall 612 of the 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 600 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 600 to a downstream nozzle end 600b. The inner wall 614b is convex and is a Coanda surface i.c. it causes fluid that flows through the fluid flow path 660 to hug thc surface of the inter 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 3c) 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 600 is attached to a hairdryer 200 as shown in Figure 3a, 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 but this is blocked by the nozzle 600. In the example shown in Figure 3a, nozzle 100 blocked the second fluid flow path 280 at the upstream end lOOa of the nozzle. In this example, the nozzle 600 uses an upstream continuation of curved wall 614b which curvcs inwards to form a rounded end 616 which blocks the sccond fluid flow path.

The nozzle 600 is inserted into the downstream end 200b of the hairdryer until a stop is reached. In this position, the fluid inlet 620 of the nozzle 600 is in fluid communication with a primary fluid outlet 230 of the hairdrver 200. The nozzle is an attachment for adjusting at least one parameter of the fluid flow emitted from the hairdryer and the downstream end 600b of the nozzle protrudes from the downstream end 200b of the hairdryer 200.

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 hairdiyer 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 292 and the duct 282, along a first handle 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 duet 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.

In order to seal the nozzle fluid flow path 660 with respect to the primary 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 hairdrycr 200. The collar 612a is upstream of the fluid inlct 620 of the nozzle 600. A second collar 612b is idcally 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 200b.

Figures 4a to 4g show an alternate double flow path nozzle 700 on a hairdryer 200. In this embodiment, components illustrated and described with respect to Figures 3a to 3g have like reference numbers. In this example, in addition to a fluid flow path 660 from an inlet 620 to an outlet 630, a further fluid flow path 780 is provided. 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 example, 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.

The hairdryer 200 has a second fluid flow path 280. This second fluid flow path 280 flows from a second inlet 270 along the length of the body 202 of the hairdryer through duct 282 to a second outlet 280 outlet where, when there is no nozzle attached to the hairdryer, fluid flowing through the second fluid flow path 280 mixes with the primary fluid at the primary fluid outlet 230. This mixed flow continues along duct 284 to the fluid outlet 200b of the hairdryer. 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. Thus, the hairdryer has a primary flow which is that processed by and drawn into the appliance by the fan unit and a second fluid flow which is entrained by the primary, processed flow.

Thus the fluid flow through the hairdryer is amplified by both the internal (second fluid flow 280) and external (entrained fluid 618) entrained flow.

The second fluid flow path 280 can be considered to flow along a tube defined by an upstream duet 282 and a downstream duet 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 100 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 100 is retained in the duet 282, 284 by friction.

When the nozzle 700 is aftached 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 fall unit 270. 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.

Figures 5a to Se show a further single flow path nozzle 10 which is similar to the one described with respect to Figure 3. In this nozzle a fluid flow path 60 is provided from an inlet 20 to an outlet 30. The inlet 20 is through an outer wall 12 of a generally tubular body 14 of the nozzle 10 between a first or upstream end lOa and a second or downstream end lOb of the nozzle 10. The outlet 30 is a slit formed between the outer wall 12 and an inner wall 32 of the nozzle.

The inner wall 32 is convex and formed by a bung 34 which is located in the downstream end 12b of the outer wall 12. Fluid that flows through the fluid flow path is funnelled by an upstream end 34a of the bung 34 towards the outlet 30. As the inner wall 32 is convex, fluid that flows out of the outlet 30 is drawn to the surface 32 by the Coanda effect and this entrains fluid 18 from the environment around the nozzle 10.

The shape of the bung 34 at the downstream end 34b is generally rectangular so the fluid exits the nozzle in a generally rectangular profile.

The rear or upstream end lOa of the nozzle has a cone shaped bung 70 so when the nozzle lOis used in conjunction with hairdryer 200 (not shown), fluid from the second fluid flow path 280 is blocked by the cone shaped bung 70.

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 o-ring, magnets, friction fit, a mechanical clip, snap fit or actuated snap fit.

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 from the appliance.

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 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 thc art.

Claims

CLAIMS1. A hairdrycr comprising a handle; a body comprising a duct; a fan unit for generating a fluid flow from a fluid inlet through which the fluid flow enters the hairdryer to an end of the duct for emitting the fluid flow from the body; and an attachment partially insertable into the end of the duct and which at least partially defines at least one aperture for emitting the fluid flow when the attachment is located in the duct, and wherein the attachment has an external surface located downstream from said at least one aperture and over which fluid emitted from said at least one aperture is directed.
2. A hairdryer according to claim 1, wherein the external surface of the attachment at least partially defines said at least one aperture.
3. A hairdryer according to claim 1 or claim 2, wherein the external surface of the attachment is convex in shape.
4. A hairdryer according to any preceding claim, wherein the external surface of the attachment comprises a Coanda surface.
5. A hairdryer according to any preceding claim, whcrein a front portion of thc extcrnal surfacc of thc attachment tapers towards a longitudinal axis of thc nozzle.
6. A hairdryer according to claim 5, wherein the front portion of the external surface of the attachment tapers to a point.
7. A hairdryer according to any preceding claim, wherein the attachment comprises a collar at least partially surrounding the external surface, and wherein the internal surface of the collar and the external surface define an external fluid flow path through which fluid from outside the hairdryer is drawn by fluid emitted from said at least one aperture.
8. A hairdryer according to any preceding claim, wherein said at least one aperture is located between the internal surface of the duct and the external surface of the attachment.
9. Ahairdiyeraccordingtoanyofclaims lto7,whereinthebodycomprisesa fluid outlet for emitting the fluid flow into the duct, and wherein the attachment comprises a fluid inlet for receiving the fluid flow fmm the fluid outlet, and a fluid flow path extending fix,m the fluid inlet to said at least one aperture.
10. A hairdryer according to claim 9, wherein the attachment comprises a first end which is insertable within the duct, and a second end remote from the first end, and whereinthefluidthetiislocatedbetweentheflrstendandthesecondendofthe attachment.
11. A hairdryer according to claim 10, wherein the fluid inlet comprises at least one aperture extending at least partially about the longitudinal axis of the attachment.
12. A hairdryer according to claim 10 or claim 11, wherein the attachment comprises a side wall between the first end and the second end of the attachment, and whcrein a portion of thc sidc wall which is located between thc first end and the second end of the attachment at least partially defines the fluid inlet
13. A hairdryer according to claim 12, wherein the side wall is tubular in shape.
14. A hairdryer according to any of claims 9 to 11, wherein the attachment comprises an outer wall extending about an inner wall which at least partially defines the fluid flow pat
15. A hairdryer according to claim 14, wherein the inner wall is tubular in shape.
16. A hairdryer according to claim 15, wherein the external surface of the attachment extends about the inner wall.
17. A hairdryer according to claim 14 or claim 15, wherein the inner wall is open at eachend,andwhereinafluidflowisdrawnthroughtheductandtheinnerwallbythe fluid flow emitted fivm said at least one aperture.
18. A hairdryer according to any of claims 9 to 11, wherein the attachment comprisesaflrstsidewallextendingfromtheflrstendtothesecondend,andasecond side wall extending at least partially about the first side wall, and wherein the fluid flow path is located between the side walls.
19. A hairdryer according to claim 18, wherein each of the first and second side walls is tubular in shape.
20. A hairdryer according to claim 19, wherein the external surface of the attachment extends about the first side wall.
21. Ahairdryeraccordingtoclaiml9orclaim2O,whereintheflrstsidewallisopen at each end, and wherein a fluid flow is drawn thmugh the duct and the first side wall by thc fluid flow cmittcd from said at least onc aperture.