WO2009124711A2

WO2009124711A2 - Hair dryer with two fans

Info

Publication number: WO2009124711A2
Application number: PCT/EP2009/002550
Authority: WO
Inventors: Arturo Morgandi; Mauro Gambirasio
Original assignee: Tenacta Group S.P.A.
Priority date: 2008-04-10
Filing date: 2009-04-07
Publication date: 2009-10-15
Also published as: ITMI20080638A1; WO2009124711A3

Abstract

A hair dryer comprising a body, within which there is a motor, an electric resistance and means suitable for generating an air-flow along an air path between an inlet for cold air and an outlet for hot air, wherein the air path comprises a first and a second section aligned along a main axis of the air path and separated by a constriction, the means suitable for generating an air-flow being a first fan positioned in the first section and a second fan positioned in the second section actuated in rotation by the motor, characterized in that it comprises a tubular element distinct from the body and mounted inside it, the air path at the constriction being formed in said tubular element.

Description

"Hair dryer with two fans"

DESCRIPTION

The present invention refers to a hair dryer having an air-jet strong enough to be able to carry out particular treatments on hair locks.

In particular, the hair dryer of the invention comprises a body, within which there are a motor and two fans actuated in rotation by the motor itself.

Conventional hair dryers have a structure comprising an air path between an inlet for cold air and an outlet for hot air and, a fan actuated by an electric motor and an air heating electric resistance situated downstream the fan being within this path.

The outlet generally has relatively wide dimensions, to allow a good air-flow to pass distributed over a suitably wide surface.

Nowadays, however, both in professional salons as well as in homes, there is ever more frequent the request to have a hair dryer with a higher concentrated air-jet to allow hair locks modelling in a particular way.

The adopted solution generally consists in applying an accessory at the hot air outlet of the hair dryers, such as a moulded nozzle, so as to have a squashed and thin outlet, to obtain a laminar air-jet. However, in practice, this solution implies the creation of a constriction on the outlet, and the consequent loss of load causes a significant and undesired airflow decrease.

To find a solution to this problem, in the patent GB 2,422,309 hair dryers comprising inside thereof a twin- shaft electric motor on which two fans are mounted in series, the first fan suitable for taking in air from outside and conveying it towards a constriction which leads to the inlet area of the second fan have been described. The air, pushed towards the constriction, undergoes a pressure increase and, in these conditions, it is conveyed towards the second fan, which then directs it towards the outlet.

In this way, by increasing the air pressure, in such a patent it is shown that it is possible to maintain a sufficiently high airflow even when an accessory, such as a nozzle, which reduces its section, is applied to the hair dryer outlet, without having any negative impacts on hair dryer size and handling.

However, this solution has some drawbacks.

In fact, the presence of said constriction affects the shape of the hair dryer outer body therein described; this fact, as well as not being very pleasant from an aesthetic point of view, it is also not very practical as far as the moulds for the production and the final assembly of the hair dryer itself are concerned.

The technical problem forming the basis of the present invention is therefore the one allowing the inner and the outer shapes of the hair dryer to be not closely correlated, so as to be allowed to separately optimize the shapes of the two parts, i.e. favouring the technical aerodynamic needs within the hair dryer and favouring the aesthetic and moulding needs at the outside.

For this purpose, the Applicant has considered a hair dryer comprising a tubular element distinct from the hair dryer body and mounted inside it. Therefore, in accordance with the present invention, the technical problem described above is solved by a hair dryer as defined in the attached claim 1.

In particular, the present invention concerns a hair dryer comprising a body, within which there are a motor, an electric resistance and means suitable for generating an airflow along an air path between an inlet for cold air and an outlet for hot air, wherein the air path comprises a first and second section aligned along a main axis of the air path and separated by a constriction, the means suitable for generating an air-flow being a first fan positioned in the first section and a second fan positioned in the second section actuated in rotation by the motor, characterized in that it comprises a tubular element separated from the body and mounted inside it, the air path at the constriction being formed in said tubular element .

In this way, such a hair dryer is able to ensure a sufficiently high air-flow towards the outlet and, at the same time, to allow the body external shape, which is aesthetically pleasing and easy to make, to be not correlated with the internal shape of the body itself.

Preferably, such a second fan is placed immediately downstream said constriction. In this way, by reducing the space between the constriction and the second fan to the minimum, the air dispersion is reduced in such an area, maintaining the air pressure at sufficiently high levels .

Preferably, said constriction has a substantially circular shape. In this way, the air flows more smoothly through the constriction. Moreover, preferably, said second fan is of the centrifugal type and also has an inlet area with a substantially circular shape having substantially the same diameter as that of said constriction, the centre of said inlet area of said second fan being substantially on the same line as the centre of said constriction, along the main axis of the air path between the cold air inlet and the hot air outlet of the hair dryer.

In this way, substantially all of the air that flows through the constriction also directly passes through said inlet area of the second fan, so to further reducing the air dispersion to the minimum.

Preferably, the tubular element comprises a sharp edge. Said sharp edge is generated by the fact that the tubular element has a diameter that, upstream of said constriction, in said first section, progressively decreases as it gets closer to said constriction, progressively then increasing again downstream said constriction, in said second section.

In this way, in said first section a draft is created which allows the air to be conveyed towards and through said constriction with a pressure increase.

Said second centrifugal type fan has an outlet area to let air going out. As previously mentioned, downstream said constriction in said second section, where the second fan is located, the diameter of said tubular element progressively increases. Preferably, the diameter of said tubular element at said outlet area of the second fan is greater than the outer diameter of the second fan so that the tubular element covers the second fan at said outlet area, creating a sort of fairing around the second fan.

In this way, the air coming out from the second fan is conveyed towards the hair dryer outlet, preventing it from returning back towards the constriction and therefore keeping the air-jet efficient.

Preferably, the tubular element at the constriction is separated from the hair dryer body, defining a gap. In this way, a space is created between the tubular element and the hair dryer body which can be advantageously exploited in many ways. For example, power cables of the electric resistance housed in the second section, downstream the second fan, may be partially housed in said gap. Said power cables of the electric resistance must not come into contact with said second fan, for obvious safety reasons for the user of the hair dryer of the present invention. Therefore, said gap thus obtained at the constriction, and therefore at the second fan, can be particularly advantageous for housing said power cables of the electric resistance, in a protected position.

Preferably, said hair dryer body comprises two coupled half-shells, facing one each other from opposite sides with respect to the main axis of the air path.

In this way, the hair dryer of the present invention has advantages from the manufacturing process point of view. Indeed, the fact that there are such two half-shells allows all the assembly, alignment and balancing operations of the motor + fans group to be carried out separately with a certain ease, obtaining a pre-assembly and, only later, allows the complete hair dryer to be obtained by incorporating such a pre-assembly between the two half-shells before the final coupling of the two half-shells .

Alternatively, preferably said body comprises two half- shells coupled together and aligned along the main axis of the air path.

Even in this case there is the advantage of being able to couple the two half-shells together to obtain the final hair dryer only after obtaining such a pre-assembly .

Preferably, said tubular element is subdivided into two substantially semi-tubular pieces, suitable for being coupled together.

In this way, there is the further advantage from the manufacturing point of view that the second piece of said tubular element can be coupled with the first piece even after having assembled all other components, before the final closing of the two half-shells. In this way the space available for the various mounting operations, adjustments and taking apart of the various components of the hair dryer is further increased.

Alternatively, said tubular element can be a single piece made. In this way there is the advantage of not having small pressure losses which can occur at the contact surfaces between the two semi-tubular pieces when the tubular element is made up of said two pieces.

Further characteristics and advantages of the hair dryer of the present invention shall become clearer from the following detailed description of preferred embodiments, given as an example and not for limiting purposes with reference to the attached drawings. In such drawings,

figure 1 is a section view of a first preferred embodiment of a hair dryer according to the present invention;

- figure 2 is an enlargement of a part of figure 1; - figure 3 is an exploded perspective view of the hair dryer of figure 1; figure 4 is a section view of a second preferred embodiment of a hair dryer according to the present invention.

With reference to figures 1-3, a first preferred embodiment of a hair dryer according to the present invention is shown, said hair dryer being indicated with 1. In such figures moreover, conventional elements generally present in hair dryers with two fans are highlighted such as, for example, a handle 2 and a body 3 inside which there are: an inlet 4 for cold air and an outlet 5 for hot air, a first fan 6 and a second fan 7 suitable for generating an air-flow along an air path between the inlet 4 and the outlet 5, an actuation motor 8 for making the first fan 6 and the second fan 7 rotate, an air heating electric resistance 9. The air path comprises a first section 60, wherein the first fan 6 and the motor 8 are housed, and a second section 70 wherein the second fan 7 and the electric resistance 9 are housed, the first and second section 60,70 being aligned along the main axis of the air path and separated by a constriction 10.

The motor 8 has a first output shaft 8a on which the first fan 6 is mounted and a second output shaft 8b, on the opposite side, on which the second fan 7 is mounted. The two fans 6 and 7 are of the centrifugal type, wherein the air is taken in from a central area and expelled peripherally. Again with reference to figures 1-3, such a hair dryer also comprises a tubular element 11, distinct from the body 3 and mounted inside it, the air path at the constriction 10 being formed in said tubular element 11.

The tubular element 11 has a diameter that, in the first section 60, upstream of the constriction 10, progressively decreases as it gets closer to the constriction 10 while, in the second section 70, downstream the constriction 10, it progressively increases. A sharp edge 12 is thus determined, at the constriction 10, which makes up a draft suitable for enabling the air in the first section 60 to be conveyed towards the constriction 10.

The second fan 7 is placed immediately downstream the constriction 10 which has a substantially circular shape. The second fan 7 has an inlet area 13 also having a substantially circular shape having substantially the same diameter as that of the constriction 10, the centre of the inlet area 13 of the second fan 7 being substantially on the same line as the centre of the constriction 10, along the main axis of the air path between the inlet 4 for cold air and the outlet 5 for hot air of the hair dryer 1.

The second fan 7 has an outlet area 14 to let air going out; the diameter of the tubular element 11 at the outlet area 14 of the second fan 7 is greater than the outer diameter of the second fan 7 so that the tubular element 11 covers the second fan 7 at the outlet area 14, creating a sort of fairing around the second fan 7.

The tubular element 11 at the constriction 10 is separated from the body 3 of the hair dryer 1, defining in this way a gap 15 between the body 3 and the tubular element 11 itself. In the gap 15, power cables of the electric resistance 9 housed in the second section 70 downstream the second fan 7 may be partially housed, in a protected position, so as to not come in contact with the second fan 7 itself.

With particular reference to figure 3, the body 3 of the first embodiment of the hair dryer 1 of the present invention, comprising two half-shells 17 and 18 facing one each other from opposite sides with respect to the main axis of the air path, is shown. The two half-shells are coupled together to form the hair dryer 1.

Again with particular reference to figure 3, two substantially semi-tubular pieces 11a and lib are visible, suitable for being coupled together to form the tubular element 11.

On the other hand, with reference to figure 4, a body 103 of a second embodiment of a hair dryer 101 of the present invention is shown, differing from the first embodiment in that its body 103 comprises two half-shells 117 and 118, aligned along the main axis of the air path. In this second embodiment, the two half-shells 117 and 118 may be coupled together to form the hair dryer 101 too. When turning on the hair dryer, the electric current powers the motor 8 and the resistance 9, which starts heating up. The motor 8 simultaneously starts rotating the first fan 6 and the second fan 7. The first fan 6 takes in air from outside through the inlet 4 and expels it inside the body 3 towards the constriction 10. The presence of the sharp edge 12 enables the air to be conveyed towards and through said constriction 10; the narrowing of the section at the constriction 10 causes a pressure increase and speed increase of the air coming from the first fan 6.

The air thus compressed passes through the constriction 10 and reaches the second fan 7, placed immediately downstream the constriction 10. In this way, substantially all the air that flows through the constriction 10 also passes through the inlet area 13 of the second fan 7, reducing the air dispersion to the minimum.

The air is then taken in by the second fan 7 and expelled by it; thanks to the fairing made by the tubular element 11 around the second fan 7, substantially all the air that comes out from the second fan 7 is conveyed towards the outlet 5 of the hair dryer, reducing the air dispersion to the minimum and therefore keeping its flow efficient .

In this way the hair dryer of the present invention has the advantage of having a sufficiently high air-flow even when an accessory is applied to the exit of the hair dryer, such as a nozzle, which reduces its section. At the same time, the hair dryer of the present invention also has the advantage that the inner and outer shapes of the hair dryer are not closely correlated, so as to optimize the aesthetic and moulding needs of the body outside it independently from the technical characteristics present inside the hair dryer itself.

Claims

1. Hair dryer comprising a body, within which there is a motor, an electric resistance and means suitable for generating an air-flow along an air path between an inlet for cold air and an outlet for hot air, wherein the air path comprises a first and a second section aligned along a main axis of the air path and separated by a constriction, the means suitable for generating an airflow being a first fan positioned in the first section and a second fan positioned in the second section actuated in rotation by the motor, characterized in that it comprises a tubular element distinct from the body and mounted inside it, the air path at the constriction being formed in said tubular element.

2. Hair dryer according to claim 1, wherein said second fan is placed immediately downstream said constriction.

3. Hair dryer according to any of the previous claims, wherein said constriction has a substantially circular shape and wherein said second fan is of the centrifugal type and has a circular shaped inlet area, having substantially the same diameter as that of the constriction.

4. Hair dryer according to any of the previous claims, wherein the tubular element comprises a sharp edge at said constriction.

5. Hair dryer according to any of the previous claims, wherein the tubular element at the constriction is separated from the hair dryer body, defining a gap.

6. Hair dryer according to claim 5, comprising power cables of the electric resistance partially housed within said gap.

7. Hair dryer according to any of the previous claims, wherein said body comprises two coupled half- shells, facing one each other from opposite sides with respect to the main axis of the air flow.

8. Hair dryer according to any of the previous claims from 1 to 6, wherein said body comprises two coupled half-shells, aligned along the main axis of the air path.

9. Hair dryer according to any of the previous claims, wherein said tubular element is subdivided into two substantially semi-tubular pieces, suitable for being coupled together.