CN207544576U - Hair dryer - Google Patents

Abstract

A hair dryer (10) is disclosed comprising a primary fluid flow path (400) extending from a primary fluid inlet (40) to a primary fluid outlet (440) for drawing primary fluid into the primary fluid flow A fan unit (70) of the path, a heater (80) for heating the primary fluid in the primary fluid flow path, wherein the primary fluid passing through the heater has a lower velocity than the primary fluid flowing through the fan unit. The heater may be downstream of the fan unit. The cross-sectional area of the primary fluid flow path may vary along the primary fluid flow path. The cross-sectional area of the primary fluid flow path may be greater around the heater than around the fan unit. The hair dryer includes a handle, and the primary fluid inlet is in the handle (20). The hair dryer (10) may include a body (30) with a primary fluid outlet in the body and a primary fluid flow path extending within the handle from the primary fluid inlet to the body.

Description

hair dryer

This application is a divisional application of a utility model patent application with an application date of April 3, 2014, an application number of 201490001398.4, and a utility model name of "hair dryer".

technical field

The utility model relates to a hand-held appliance, in particular to a hair care appliance, such as a hair dryer or a heating and styling brush.

Background technique

Hair dryers, especially hot air dryers, are used in a variety of applications such as drying substances such as paint or hair, and removing or stripping surface layers. Alternatively, hot air blow dryers (such as heated styling brushes) are used to style hair in wet or dry conditions.

Typically, a motor and fan are provided which draw fluid into the body; the fluid may be heated before leaving the body. The motor is prone to damage from foreign matter such as dirt or hair, so a filter is usually provided at the fluid inlet end of the hair dryer. Often such appliances are provided with a nozzle which can be attached to and detached from the appliance and which varies the shape and velocity of the fluid flow exiting the appliance. Such nozzles are used to concentrate or diffuse the outflow of the appliance according to the needs of the user at that point in time.

Utility model content

According to the first aspect, the utility model provides a hair dryer.

In a preferred embodiment, the hair dryer comprises a main fluid flow path extending from the main fluid inlet to the main fluid outlet, a fan unit for drawing the main fluid into the main fluid flow path, for heating the A primary fluid heater, wherein the primary fluid passing through the heater has a lower velocity than the primary fluid flowing through the fan unit.

Preferably, the heater is downstream of the fan unit.

In a preferred embodiment, the cross-sectional area of the primary fluid flow path varies along the primary fluid flow path.

Preferably, the cross-sectional area of the primary fluid flow path is greater around the heater than around the fan unit.

In a preferred embodiment, the hair dryer comprises a handle, wherein the primary fluid inlet is in the handle.

Preferably, the hair dryer comprises a body and the primary fluid outlet is in the body, wherein the primary fluid flow path extends within the handle from the primary fluid inlet to the body.

In a preferred embodiment, the fan unit is arranged in the handle.

Preferably, the handle is substantially perpendicular to the body.

In a preferred embodiment, the primary fluid flow path flows in a first direction within the handle and in a second direction within the body.

Preferably, the first direction is substantially perpendicular to the second direction.

In a preferred embodiment, the primary fluid flowing through the primary fluid outlet has a higher velocity than the primary fluid flowing through the heater.

Preferably, the primary fluid flowing into the primary fluid inlet has a similar velocity to the primary fluid flowing through the heater.

In a preferred embodiment the velocity of the primary fluid increases from the primary fluid inlet to the fan unit.

Preferably the velocity of the primary fluid decreases from the fan unit towards the body.

In a preferred embodiment, the hair dryer includes a fluid flow path extending from a fluid inlet into the body to a fluid outlet from the body.

Preferably, within the body, the primary fluid flow path surrounds the fluid flow path.

In a preferred embodiment, the body includes an internal conduit separating the primary fluid flow path and the fluid flow path.

Preferably, the heater surrounds the inner pipe.

In a preferred embodiment, the heater extends along the inner conduit.

Preferably, the hair dryer comprises a high speed motor. The hair dryer comprises a fan unit for generating an air flow, the fan unit comprising an air inlet, an air outlet, an impeller and a motor for rotating the impeller to generate an air flow flowing from the air inlet to the air outlet, wherein the motor has a rotor , which in use is capable of rotating at a speed of at least 50,000 rpm. Preferably, the rotor is capable of rotating at a speed of at least 80,000 rpm. Preferably, the rotor is capable of rotating at a speed of up to 11,0000 rpm. Preferably, the hair dryer is an amplified hair dryer, so the fan unit does not handle all the flow exhausted from the hair dryer, ie some of the flow passing through the hair dryer is drawn into the dryer by the operation of the motor. Fluid wicking for hair irons. Preferably, the fan unit is housed within the handle of the hair dryer.

The utility model provides a hair dryer, which includes a fan unit, and the fan unit includes a high-voltage motor. Preferably, the pressure generated by the motor is between 1400 and 2250 Pa. This corresponds to a flow rate of 9.4 to 12 l/s and a motor speed of 8,4000 to 10,5000 rpm for a motor arranged within a cross-sectional area of 25 mm ² . Thus, the motor resides within a grippable handle, preferably having a diameter of 35 to 42 mm.

According to the invention, the thickness of the outer wall is preferably less than 2 millimeters, and more preferably less than 1 millimeter thick. Ideally, the thickness is about 0.7 mm.

In another aspect, the handle diameter is between 20 and 60 mm, and preferably between 30 and 50 mm. Most preferably, the handle diameter is between 35 and 42 mm.

According to the utility model, the hair dryer has a handle, the handle includes a motor, and the wall of the handle is lined with a lining material. Typically, the lining material has a thickness of between 4 and 6 mm.

According to the present invention, the hair dryer comprises a handle, the handle accommodates the fan unit and the handle is lined with a lining material. The lining material preferably includes at least one of an inlet muffler and an outlet muffler. Preferably, the length of the outlet muffler _SO (from the downstream end of the fan unit to the downstream end of the handle) is up to 100 mm long. Preferably, the inlet muffler S _I (from the upstream end of the fan unit to the downstream end of the inlet) is 10 to 200 mm long. Preferably, the ratio between the inlet muffler S _I and the outlet muffler S _O is greater than 1.2. In hair dryers 10 with handles 20 of constant diameter, this ratio is preferably greater than 0.1.

According to the invention, there is a relationship between the length Lx of the body from the fluid inlet to the upstream edge of the handle and the length Lz of the body from the downstream edge of the handle to the fluid outlet at the downstream end of the body. Ideally, Lz≦40 mm and Lx≦20 mm. Preferably 2Lx=Lz.

According to the invention, the hair dryer has a relationship between the diameter d _a of the outer wall of the body and the diameter d _b of the inner duct. In hair dryers with handles of constant diameter, the ratio d _b :d _a is preferably between 0.49 and 0.6.

According to the invention, in hair dryers with handles of non-constant or varying diameter, the ratio d _b : da _a is preferably between 0.4 and 0.9.

According to the present invention, the hair dryer has a relationship between the length _l2 of the body and the diameter _dh of the handle. In hair dryers with handles of constant diameter, the ratio l ₂ :d _h is preferably between 1.9 and 2.5. In hair dryers with non-constant or varying diameter handles, the ratio _l2 : _dh is preferably between 1.9 and 2.5.

According to the invention, the hair dryer has a correlation between the diameter d _a of the outer wall of the body and the diameter d _h of the handle. In hair dryers with constant diameter handles, the ratio _da : _dh is preferably between 1.6 and 3.4.

According to the invention, the hair dryer has a relationship between the length _l2 of the body and the diameter _da of the body. In hair dryers in which the handle is provided with a fan unit, the ratio l ₂ :d _a is preferably between 1.1 and 1.6. For hair dryers, where the heater is in the body and the fan unit is in the handle, the ratio _l2 :d _a is preferably between 0.8 and 1.6.

According to the invention, the hair dryer has a relationship between the length _l2 of the body and the diameter _db of the inner pipe. The l ₂ :d _b ratio is preferably between 1.8 and 3.4. For hair dryers, where the heater is in the body and the fan unit is in the handle, the ratio l ₂ :d _a is preferably between 1 and 3.4.

According to the invention, the hair dryer has an inner duct which is connected to the outer wall through the side wall. In one embodiment, the side walls are perpendicular to the outer wall.

According to the present invention, the hair dryer includes a handle and a body, wherein the fluid in the main fluid flow path in the body is at an angle of 90° to the fluid in the main fluid flow path in the handle. Preferably, the primary fluid flow within the body is parallel to the fluid flowing through the fluid flow path.

According to the utility model, the hair dryer comprises a body having an internal duct comprising a conical portion and a tubular portion, wherein the radius r between the conical portion and the tubular portion of the internal duct is between 0.5 and 50 mm between.

According to the invention, the hair dryer comprises a body having an internal duct comprising a conical portion and a tubular portion, wherein the conical portion at least partially defines a fluid inlet and the tubular portion at least partially defines a fluid outlet , wherein the diameter of the inner conduit increases from the tapered portion towards the fluid outlet.

According to the invention, the hair dryer comprises a body comprising an outer wall, an inlet end and an outlet end, wherein a chamfer is provided at the outlet end, wherein at the chamfer the diameter of the outer wall faces towards the The center A-A decreases, and wherein the chamfer is between 30° and 60°. Ideally, the chamfer is between 30° and 60°. Preferably, a front chamfer of 35° to 55°, and more preferably a chamfer of 45° is provided.

According to the present utility model, the hair dryer has a body comprising a main fluid outlet defined by a first surface and a second surface of the body, wherein the first surface and the second surface are substantially parallel surfaces, They respectively define an outer annular limit and an inner annular limit of the main fluid outlet. Preferably, the body includes an internal conduit, the first and second surfaces also being generally parallel to the internal conduit.

According to the present utility model, the hair dryer has a body comprising a main fluid outlet defined by a first surface and a second surface of the body, wherein the first surface and the second surface are substantially parallel surfaces, They respectively define an outer annular limit and an inner annular limit of the main fluid outlet. Preferably, the body includes an internal conduit, the first and second surfaces also sloped towards the internal conduit adjacent the primary fluid outlet.

According to the present utility model, the hair dryer has a body comprising a main fluid outlet defined by a first surface and a second surface of the body, wherein the first surface and the second surface are substantially parallel surfaces, They respectively define an outer annular limit and an inner annular limit of the main fluid outlet. Preferably, the body includes an internal conduit, and the first and second surfaces are further sloped away from the internal conduit adjacent the primary fluid outlet.

According to the invention, the hair dryer comprises a body having a tubular outer wall and a handle substantially perpendicular to the body, the body having a fluid inlet at least partially defined by the side wall extending from the tubular outer wall towards the center of the tubular outer wall , wherein the side wall forms an angle between 1° and 90° relative to the tubular outer wall. Preferably, the angle is between 30° and 60°. More preferably, the angle is 45°.

Description of drawings

The utility model will now be described by way of example with reference to the accompanying drawings, in which:

Figure 1 shows a perspective view of a hair dryer according to the present invention;

Figure 2 shows a cross-sectional view through the hair dryer in Figure 1;

Figure 3a shows a side view of the inner wall of the hair dryer;

Figure 3b shows a cross-sectional view through the internal duct of the hair dryer.

Figure 4 shows a side view of the hair dryer;

Figure 5 shows a rear end view of the hair dryer;

Figure 6 shows another side view of the hair dryer;

Figure 7 shows a front end view of the hair dryer;

Figure 8 shows a bottom view of the hair dryer;

Figure 9 shows a rear perspective view of the hair dryer;

Figure 10 shows a graph of the length of the silencer in the handle of the hair dryer;

Figures 11a to 11d show end views of an alternative hair dryer according to the present invention;

Figure 12 shows a side view of the hair dryer according to the present invention;

Figures 13a to 13d show side views of a hair dryer according to the present invention;

Figures 14a and 14b show end views of some other hair dryers according to the present invention;

Figures 15a, 15b and 15c show side views of some hair dryers according to the present invention;

Figures 16a, 16b, 16d and 16e show side views of alternative hair dryers according to the present invention;

Figures 16c and 16f show respective end views of the alternative hair dryers of Figures 16a, 16b, 16d and 16e;

Figures 17a to 17c show side views through a hair dryer according to the invention;

Figures 18a to 18d show side views through other hair dryers according to the invention;

Figures 19a and 19b show an alternative front chamfer for a hair dryer according to the invention;

Figures 20a to 20c show alternative outlet arrangements for hair dryers according to the invention;

Figure 21 shows a side view through the hair dryer in use;

Figure 22a shows a graphical representation of the velocity distribution through a hair dryer according to the invention;

Figure 22b schematically shows the cross-sectional area of the primary fluid flow path.

Detailed ways

1 and 2 show a hair dryer 10 having a handle 20 and a body 30 . The handle has a first end 22 (connected to the body 30) and a second end 24 (distant from the body 30 and which includes a primary fluid inlet 40). Power is supplied to the hair dryer 10 through the cable 50 .

The body 30 has a first end 32 and a second end 34 and can be considered to have two parts. Extending from the first end 32 is a first portion 36 , which is generally tubular, and a second portion 38 extends from the second end 34 to join the first portion 36 . This second portion 38 is conical in shape and its diameter varies along its length from the diameter of the first portion 36 of the body 30 to a smaller diameter at the second end 34 of the body. In this embodiment, the second portion 38 has a constant inclination, and in this embodiment the angle α subtended by the outer wall 360 of the first portion 36 of the body 30 is about 40°.

The handle 20 has an outer wall 200 extending from the body 30 to the end 24 of the handle. At the end 24 of the handle, an end wall 210 extends across the outer wall 200 . The cable 50 enters the hair dryer through this end wall 210 . Primary fluid inlet 40 in handle 20 includes a first aperture 42 (which extends around and along outer wall 200 of the handle) and a second aperture 46 (which extends across and through end wall 210 of handle 20 ). The cable 50 is positioned generally in the middle of the end wall 210 thereby extending from the center of the handle 20 . The end wall 210 is perpendicular to the outer wall 200 and the inner wall 220 of the handle.

A fan unit 70 is provided upstream of the main fluid inlet 40 . The fan unit 70 includes a fan and a motor. The fan unit 70 draws fluid through the primary fluid inlet 40 towards the body 30 through a primary fluid flow path 400 that extends from the primary fluid inlet 40 and enters the body 30 at the junction 90 of the handle 20 and body 30 . The primary fluid flow path 400 continues through the body 30 towards the second end 34 of the body, around the heater 80 and to the primary fluid outlet 440 where fluid drawn by the fan unit exits the primary fluid flow path 400 . Primary fluid flow path 400 is non-linear and flows through handle 20 in a first direction and through body 30 in a second direction (which is perpendicular to the first direction).

The body 30 has an outer wall 360 and an inner duct 310 . The primary fluid flow path 400 extends along the body from between the outer wall 360 and the conduit 310 from the junction 90 of the handle 20 and the body 30 toward the primary fluid outlet 440 .

Another fluid flow path is provided within the body, this fluid is not handled directly by the fan unit or heater, but is drawn into the hair dryer by operation of the fan unit creating a main flow through the hair dryer. This fluid flow is entrained by the fluid flowing through the primary fluid flow path 400 into the hair dryer.

The first end 32 of the body 32 includes a fluid inlet 320 and the second end 34 of the body includes a fluid outlet 340 . Both the fluid inlet 320 and the fluid outlet 340 are defined at least in part by the conduit 310 (which is an interior wall of the body 30 extending within and along the body). Fluid flow path 300 extends within the conduit from fluid inlet 320 to fluid outlet 340 . At the first end 32 of the body 30 , a side wall 350 extends between the outer wall 360 and the duct 310 . This side wall 350 at least partially defines the fluid inlet 320 . At the second end 34 of the body, a gap is provided between the outer wall 360 and the duct, this gap defining the primary fluid outlet 440 . The primary fluid outlet 440 is annular and surrounds the fluid flow path. The primary fluid outlet 440 may be internal, and thus the primary fluid flow path 400 merges with the fluid flow path 300 within the body 30 . Alternatively, primary fluid outlet 440 is external and exits body 30 at fluid outlet 340 independently of fluid from fluid flow path 300 .

The outer wall 360 of the body converges towards the centerline A-A of the duct 310 and the body 30 . An advantage of having the outer wall 360 that converges towards the duct 310 is that the primary fluid exiting the primary fluid outlet 440 is directed towards the centerline A-A of the body 30 . Due to the movement of the fluid from the main fluid outlet 440, fluid exiting the main fluid outlet 440 will cause external entrainment of some fluid 490 from the outside of the hair dryer. This effect is increased by the closer of the outer wall 360 towards the duct 310 . This is partly because the main flow is concentrated rather than divergent, and partly because of the slope of the outer wall 360 of the body 30 towards the second end 34 of the hair dryer.

The duct 310 is the inner wall of the hair dryer, which is accessible from the outside of the hair dryer. Thus, the duct 310 is the outer wall of the hair dryer. The duct 310 is recessed into the body 30 such that the side wall 350 connecting between the outer wall 360 and the duct 310 is angled with respect to the outer wall 360 .

A PCB 75 including the control electronics for the hair dryer is disposed within the body 30 adjacent the fluid inlet 320 and the side wall 350 . The PCB 75 is annular in shape and extends around the duct 310 between the duct 310 and the outer wall 360 . PCB 75 is in fluid communication with primary fluid flow path 400 . The PCB 75 extends around the fluid flow path 300 and is independent of the fluid flow path 300 by the conduit 310 .

The PCB 75 controls such parameters as the temperature of the heater 80 , the rotation speed of the fan unit 70 . Internal wiring (not shown) electrically connects the PCB 75 to the heater 80 and fan unit 70 and the cable 50 . Control buttons 62, 64 are provided and connected to the PCB 75 to enable the user to select from a range of eg temperature settings and flow speeds.

In use, fluid drawn into the primary fluid flow path 400 by operation of the fan unit 70 is optionally heated by the heater 80 and expelled from the primary fluid outlet 440 . This treated fluid causes fluid to be entrained into fluid flow path 300 at fluid inlet 320 . This fluid is combined with the treated fluid at the second end 34 of the body. As in the embodiment shown in FIG. 2 , the treated fluid exits the main fluid outlet 440 and the hair dryer in an annular fluid that surrounds the entrained fluid that is discharged from the hair dryer through the fluid outlet 340. Thus, fluid treated by the fan unit and heater is enhanced by entrained flow.

The handle 20 has an outer wall 200 and an inner wall 250 that at least partially define a primary fluid flow path 400 through the handle 20 . The inner wall 250 extends from the body 30 towards the second end 24 of the handle 20 to a downstream end 254 . The handle 20 is tubular and the outer wall 200 of the handle 20 is a cylindrical sleeve manufactured from any suitable material such as molded plastic or rolled sheet metal such as aluminium, aluminum alloy or steel. The handle is connected to the body 30 at a first end 22 and at a distal, second end 24 a primary fluid inlet 40 is provided. The primary fluid inlet 40 is a first means of filtering fluid entering the primary fluid flow path 400 .

Referring now to FIG. 3 , a liner material 270 is positioned between the inner wall 250 and the outer wall 200 . The liner material 270 is foam or felt which at least attenuates the noise generated when fluid is drawn into the handle 20 by the fan unit 70 (has a sound deadening effect). Liner material 270 is shown surrounding only a portion of inner wall 250 for clarity. To enable contact between liner material 270 and fluid flow within primary fluid flow path 400 , thereby attenuating noise, inner wall 250 is provided with perforations 256 surrounding and extending at least partially along the length of inner wall 250 .

Liner material 270 is provided to reduce noise generated when fluid is drawn into primary fluid inlet 40 by operation of fan unit 70 .

The perforations 256 of the inner wall 220 have a diameter selected to be most effective at attenuating noise. A diameter of 1 mm to 10 mm is suitable, smaller diameters are better for better sound power (reducing sound over the main human voice range), and larger diameters are good for high frequency attenuation. The perforations preferably form at least 40% of the surface area of the inner walls 220,250.

By arranging the liner material 270 behind the inner wall 250 , it is possible to use a greater thickness of the liner material than if the liner material 270 was directly exposed to the primary fluid flow path. This is because the diameter of the primary fluid flow path 400 is defined by the inner wall 250 which squeezes the lining material 270 into the gap between the inner wall 250 and the outer wall 200 of the handle 20 . Typically, the lining material is between 4 and 6 millimeters thick but will be compressed between the outer wall 200 and the inner wall 250 .

An important feature of having a multi-layer handle 20 is that material properties can be used to improve the mitigation of noise produced by the product. Airborne noise generated by the fan unit 70 and fluid flow into the primary fluid flow path 400 is attenuated by the lining material 270 , however some noise is transmitted through the lining material 270 .

An additional feature required for the handle 20 is that it is stiff enough to provide a grippable handle that will not be prone to bending that would introduce constraints into the primary fluid flow path. Therefore, materials such as aluminum or carbon fiber reinforced composites are ideal because they provide light and stiff tubes. Alternatively, the outer wall is made of plastic material. Those skilled in the art will recognize that other materials will provide similar benefits.

In order that the diameter of the handle 20 is not too large for the user, the thickness of the outer wall 200 is preferably less than 2 millimeters, and more preferably less than 1 millimeter thick. Ideally, the thickness is about 0.7 mm. Having a relatively thin outer wall of the handle 20 also reduces the weight of the product.

When having a high-speed motor, the noise generated is high-frequency, and some noise can irritate the human ear. However, this has advantages when high frequencies can be more effectively attenuated.

The handle diameter is ideally between 20 and 60 mm, and preferably between 30 and 50 mm. Most preferably, the handle diameter is between 35 and 42 mm. To maximize noise reduction and provide a grippable handle, the present invention uses a combination of materials in the handle 20 . Firstly the outer layer 200 is hard and thin so that sound attenuation within the handle 20 by the sound dampening medium, ie the lining material 270 , can be maximized by maximizing the thickness of the lining material 270 within the handle 20 . Ideally, at least 6 mm of liner material 270 or sound deadening media is required to attenuate the higher frequency noise (typically about 1.8 to 2 Khz) produced by high speed motors.

Referring now to FIG. 7, the length of the liner material 270 is also important. It is desirable to have the lining material 270 both upstream of the motor 70 and downstream of the motor 70 because the motor generates noise when fluid enters and exits the motor.

Reference is now made to FIG. 10 , which shows a graphical representation of the noise generated by the high speed motor within the handle 20 versus the distance from the fan unit 70 to the inlet 40 . Generally, the longer the length of liner sound deadening material the more sound is attenuated, but there is a limit to how long a product can be and still be practical. Therefore, for a hair dryer with a motor in the handle 20, there is an optimum position for the length of the motor in the handle 20 from a noise point of view. The longer the inlet muffler the more sound is attenuated as the motor moves along the x-axis away from the inlet, as can be seen in the illustration, the noise reduction along the x-axis of the inlet 280 . However, for a given length l _h of the handle, the longer the inlet muffler S _I the shorter the outlet muffler S _O must be.

For the outlet muffler S _O , the outlet noise level 282 for the outlet muffler S _O is minimized for a given handle length l _h if the motor is positioned at the inlet (zero value of the x-axis), so that when the motor moves along the handle , the outlet muffler S _O length is reduced and the noise attenuation is reduced, so the sound level rises. There is therefore an optimum distance for the motor to the inlet. In amplified hair dryers, where the primary fluid flow path 400 flows from the handle 20 into the body 30, the primary fluid flow path is shaped and sized from a circular cross-section 400a in the handle to a circular or circular cross-section in the body 400b Variation. For this reason, the inlet and outlet mufflers within the handle are not identical in sound because some of the noise produced by the fluid exhaust motor is attenuated by the fluid entering the body 30 .

The combined noise output 284 from the inlet muffler _SI and outlet muffler _SO is the compressor value on the graph, which first decreases as the motor is moved away from the inlet to reach the sweet spot where the inlet muffler _SI and outlet muffler S _O intersects and then rises again.

The total noise output 288 of the hair dryer is the sum of the compressor value 284 and the amplifier value 286 (which is the noise generated within the body 30 of the hair dryer and this value is not affected by the position of the motor within the handle 20). For this particular hair dryer, the optimum inlet muffler S _I is 70 to 100 mm. However, this value will change if for example any of the motor speed, handle diameter or inlet characteristics are changed.

Preferably, the length of the outlet muffler _SO (from the downstream end 70b of the fan unit 70 to the downstream end 22 of the handle 20) is up to 100mm long. Preferably, the inlet muffler _SI (from the upstream end 70a of the fan unit to the downstream end 40b of the inlet 40) is 10 to 200 mm long. Preferably, the ratio between the inlet muffler S _I and the outlet muffler S _O is greater than 1.2. In hair dryers 10 with handles 20 of constant diameter, this ratio is preferably greater than 0.1.

Referring now to FIGS. 5 , 11 a , 11 d , the hair dryer 10 has a relationship between the diameter _da of the outer wall 360 of the body 30 and the diameter _db of the inner duct 310 . In hair dryers 10 with handles 20 of constant diameter, the ratio d _b :d _a is preferably between 0.49 and 0.6, as shown in Figures 11c and 11d. In hair dryers 130 having a handle 132 of non-constant or varying diameter, the ratio d _b :d _a is preferably between 0.4 and 0.9, as shown in Figures 11a and 11b.

Referring now specifically to FIG. There is a relationship between. Ideally, Lz≤40mm and Lx≤20mm. Preferably 2Lx=Lz.

Referring now to FIGS. 13a and 13b , hair dryers 132 , 134 have a relationship between the length l ₂ of the body 30 and the diameter d _h of the handle 20 . In hair dryers 10 with handles 20 of constant diameter, the ratio l ₂ :d _h is preferably between 1.9 and 2.5. In hair dryers 160, 162 having a handle 164 of non-constant or varying diameter, the ratio _l2 : _dh is preferably between 1.9 and 2.5, as shown in Figures 13c and 13d.

Referring now to Figures 14a, 14b, the hair dryers 136, 138 have a relationship between the diameter _da of the outer wall 360 of the body 30 and the diameter _dh of the handle 20. In hair dryers 10 with handles 20 of constant diameter, the ratio _da : _dh is preferably between 1.6 and 3.4.

Referring now to FIGS. 15a to 15c, the hair dryers 140 and 142 have a relationship between the length l ₂ of the body 30 and the diameter _da of the body 30 . In a hair dryer 10 in which the handle 20 is provided with a fan unit 70, the ratio l ₂ :d _a is preferably between 1.1 and 1.6. For a hair dryer 144, where the heater 80 is in the body 30 and the fan unit 70 is in the handle 20, as shown in Fig. 15c, the ratio _l2 : _da is preferably between 0.8 and 1.6.

Referring now to Figures 16a to 16c, the hair dryers 146, 148 have a relationship between the length _l2 of the body 30 and the diameter _db of the inner conduit 310. The l ₂ :d _b ratio is preferably between 1.8 and 3.4. Referring now to Figures 16c, d to 16f, for hair dryers 150, 152 in which the heater 80 is in the body 30 and the fan unit 70 is in the handle 20, the ratio _l2 : _da is preferably between 1 and 3.4.

Another feature of the present invention is that the fluid in the primary fluid flow path 400 b in the body 30 is at 90° relative to the fluid in the primary fluid flow path 400 a in the handle 20 . The primary fluid flow within body 30 is parallel to the fluid flowing through fluid flow path 300 .

Referring now to Figures 2, 3a and 9, the inner conduit 310 has a generally tubular portion 312 (which extends from the fluid outlet 340 towards the fluid inlet 320) and a generally tapered portion 314 which forms a side wall 350 connected to the generally tubular portion. 312 and the outer wall 360 of the body 30 .

The side wall 352 may be perpendicular to the outer wall 360, as shown in Figure 17a. In practice, the separate side walls 350, 352 may be omitted and the inner conduit 354 may extend from the fluid inlet 320 as a cylinder having a diameter that tapers in a frusto-conical fashion towards the fluid outlet 340.

Referring to Figure 18a, the inner duct 354a extends from the outer wall 360 at the first end 32 and bends at the second end 36 towards the tube forming a circular duct. The form created by the inner duct 354a is a trumpet shape. Figure 18b shows an inner duct 354b similar to that in Figure 18a, however, the tapered portion 358 of the inner duct 354b is shorter to give a steeper gradient to the fluid inlet.

The gradually curved inner conduit has the benefit that noise is reduced because less turbulence is created there as fluid enters the fluid flow path at fluid inlet 320 . Having curved sidewalls is acoustically beneficial since the flow entrained into the fluid flow path 300 does not encounter any sharp corners that would introduce eddies and increase noise production. This side wall is integrated into the tubular portion of the inner duct 310 .

Figure 18c shows the combination of the inner conduit 354a and flared hole 354c in Figure 18a. The inner conduit 362 extends from the first end 32 to a transition point 364 (where the cylinder changes with a gradually decreasing diameter to slightly increase in diameter towards the second end 34). This splay of the inner tubing increases the entrainment of fluid entering the fluid inlet 320 .

Figure 18d shows the combination of tapered portion 358 and flared inner conduit 354d in Figure 18b. The flared portion can be longer by having the inner conduit 354d have a shorter tapered region.

In practice, any angle between 1° and 90° may be selected for the angle β between the outer wall 360 and the inner ducts 350, 354a, 354b, 354c, and 354d.

With particular reference to Figures 18c and 18d, the radius r between the tapered portion 358, 362 and the tubular portion 312 of the inner conduit 354d, 354c may vary. This radius is preferably between 0.5 and 50 mm.

Alternatively, the inner conduit 310 can increase in diameter from the side wall 366 towards the fluid outlet 340, as shown in Figures 17b and 17c. This is advantageous because it increases the flow entrained through the fluid flow path 300 . Thus, either the total emission from the fluid outlet 340 and the main fluid outlet 440 is increased, or the fan unit can be run at a lower speed to produce an equal overall output, reducing the noise of the product. The increase in the diameter of the inner duct 310 is more evident in FIG. 17c , which results in more entrainment through the inner duct 310 .

Referring now to FIG. 7, the length of the lining material within the handle 20 may vary. Preferably, the length of the inlet muffler _S1 (from the downstream end 40b of the inlet 40 to the upstream end 70a of the fan unit 70) is between 10 and 200 mm.

The front portion 38 of the hair dryer may have various chamfers 372, 374, 376 (as shown in FIGS. . The diameter decreases towards the center A-A of the outer wall 360 . The front chamfers 372 , 374 , 376 affect the external entrainment 490 from the outside of the hair dryer due to the movement of fluid from the main outlet 440 . The stiff front surface for body 30 will restrict flow for external entrainment 490 and for fluid passing through fluid flow path 300 . Ideally, a front chamfer between 30° (as shown in Figure 19a) and 60° (as shown in Figure 19b) is chosen. Preferably, a front chamfer of between 35 and 55° and more preferably 45° is provided as this provides a reasonable amount of external entrainment 490 .

The direction of fluid exiting the primary fluid outlet can vary depending on the desired result. Figures 20a, 20b and 20c show different air discharges for the primary fluid. Shown with reference to FIG. 20 a , the primary fluid outlet 440 has first 442 and second 444 generally parallel surfaces that respectively define outer and inner annular boundaries for the primary fluid outlet 440 . The first 442 and second 444 generally parallel surfaces are in turn generally parallel to the inner conduit 310 . This arrangement provides a balance between outer entrained fluid 490 and inner entrained fluid 492 (i.e., fluid that is drawn into fluid flow path 300).

In FIG. 20b the primary fluid flow path 440a is directed towards the center of the outer wall 360 of the body 30 . In this embodiment, the first 446 and second 448 surfaces defining the primary fluid outlet 440a are generally parallel to each other but inclined relative to the inner conduit 310 . The primary fluid outlet 440a is directed towards the center of the inner conduit 310 and outer body 360 . Fluid 494 exiting primary fluid outlet 440 a is directed toward fluid emitted from fluid outlet 340 , as is externally entrained fluid 490 . This gives a more concentrated output from the hair dryer as the fluid is all directed towards the internally entrained fluid flowing through the inner conduit 310, whereby the fluid sprayed from the hair dryer is concentrated into a smaller cross-sectional area , the hair dryer will feel more powerful. This arrangement will give relatively more externally entrained fluid 490 and less internally entrained flow within the internal conduit 310 than the non-inclined embodiment depicted in Figure 20a.

In FIG. 20c the primary fluid outlet 440b is directed away from the center of the outer wall 360 of the body 30 . In this embodiment, the first 450 and second 452 surfaces defining the primary fluid outlet 440a are generally parallel to each other but sloped away from the inner conduit 310 . The primary fluid outlet 440b is directed towards the outer wall 360 . Fluid 496 exiting primary fluid outlet 440b is directed away from fluid emitted from fluid outlet 340 and entrained fluid 490 toward the outside. This gives a more diffused output from the hair dryer as the fluid is all directed outwards, whereby the hair dryer will feel less forceful as the fluid sprayed from the hair dryer is spread into a larger cross-sectional area . This arrangement will give relatively less externally entrained fluid 490 and relatively more internally entrained fluid along the internal conduit 310 than the non-tilted embodiment depicted in FIG. 20a.

FIG. 21 shows the accessibility of the control buttons of hair dryer 10 and the ergonomic benefits of positioning control button 64 (shown in FIG. 2 ) on the angled surface of the body of the hair dryer. When the hair dryer is normally grasped by the handle 500 , conventionally the thumb will be positioned to form a full or partial circle around the handle with the index finger 502 . In the present hair dryer 10, the thumb 504 can be grasped conventionally, but the thumb can also be operated to change the setting ( such as temperature and/or flow through the dryer). Thus, the user can change the settings of the hair dryer 10 without adjusting the grip other than a possible movement of the thumb from the handle 20 radially to the side wall 350 . The side wall 350 is preferably angled relative to the outer wall 360 of the body 390 . This angle γ is ideally between 1° and 90°, and preferably between 30° and 60°. The angle γ of 45° is most preferred.

Figure 22a shows a graphical representation of the velocity profile through the hair dryer 10. At the fluid inlet 40, fluid entering the fluid inlet 40 is at a relatively low velocity 402, and as the fluid passes through the inlet muffler, the velocity 404 increases as the cross-sectional area within the handle 20 decreases. Likewise, as the fluid enters the fan unit, the velocity 406 increases again due to the further restriction of the fluid flow path 400 through the motor and impeller of the fan unit 70, and upstream of the fan unit 70, when the fluid flow path is again less When limited, the velocity 408 through the exit muffler is reduced. The minimum velocity 410 is reached when the fluid travels from the handle 20 into the body 30 of the hair dryer 10. This is because the body 30 has a larger cross-sectional area than the handle and acts as an air chamber (which is filled with fluid, slowing it down). Within this body, the velocity 410 is similar to the velocity at the inlet 402 . As the fluid passes through the heater 80, the velocity 412 increases slightly due to the small restriction provided by the heater element to the fluid flow. As fluid approaches primary fluid outlet 440 , the cross-sectional area within body 30 decreases to an annulus defining primary fluid outlet 440 at which velocity within the body increases to maximum velocity 414 .

Allowing the velocity to decrease as the fluid moves from the fan unit to the heater 80 has several advantages: the body 30 behaves as an air chamber (which stabilizes the fluid as it passes from the circular fluid 400a in the handle 20 to the annular fluid 400b in the body 30 fluid). This deceleration in the fluid allows it to flow more evenly through the heater 80 so velocity and turbulence are reduced, noise generated by the hair dryer is reduced, and there is a more even load around the ring forming the primary fluid outlet 440 .

The main reason for the decrease in speed from fan unit speed 406 to heater speed 412 is the cross-sectional area of the fluid flow path from area _A1 in circular fluid 400a within the handle to cross-sectional area _A2 in annular fluid 400b within body 30 This is schematically shown in Figure 22b, A ₂ >A ₁ .

Although the outer wall 200 of the handle 20 has been described as being fabricated from rolled sheet metal, alternative fabrication methods and materials may be used, these include, but are not limited to, extruded tubes and plastic extruded/molded tubes or composite tubes ( such as carbon fiber reinforced plastics).

The invention has been described in detail in relation to a hair dryer, but it is applicable to any appliance that sucks in fluid and directs it out of the appliance.

The appliance can be used with or without a heater; the action of the fluid coming out at high velocity has a drying effect.

The fluid flowing through the appliance is typically air, but can be one or more gases in various combinations, and can include additives to improve appliance performance or the effect of the appliance on the object the output is aimed at, such as hair and hair hairstyle.

The invention is not limited to the detailed description given above. Many modifications will be apparent to those skilled in the art.

Claims (7)

1. A hair dryer, characterized in that the hair dryer comprises a body comprising an outer wall, an inlet end and an outlet end, wherein a chamfer is provided at the outlet end, wherein at the chamfer , the diameter of the outer wall decreases toward the center A-A of the outer wall, and wherein the chamfer is in the range of 30° to 60°. 2. The hair dryer according to claim 1, wherein the handle is substantially perpendicular to the body. 3. A hair dryer according to claim 1 or 2, wherein the body comprises an internal duct. 4. Hair dryer according to claim 1 or 2, characterized in that the body has an outer wall and the handle has a diameter, the ratio between the diameter d _a of the outer wall of the body and the diameter d _h of the handle is in the range of having a constant diameter handle In the hair dryer, it is in the range of 1.6 to 3.4. 5. Hair dryer according to claim 1 or 2, characterized in that the ratio between the length _l2 of the body and the diameter _da of the body is in the range of 1.1 to 1.6. 6. Hair dryer according to claim 5, characterized in that in the hair dryer with the heater in the body, the ratio _l2 :d _a is in the range of 0.8 to 1.6. 7. The hair dryer according to claim 3, characterized in that the ratio between the length _l2 of the body and the diameter _db of the inner pipe is in the range of 1.8 to 3.4.