WO2023118683A1

WO2023118683A1 - Hair-styling appliance comprising an improved blower module with counter-rotating fans, and an interposed porous medium

Info

Publication number: WO2023118683A1
Application number: PCT/FR2022/052303
Authority: WO
Inventors: Matthieu FUIN
Original assignee: Seb S.A.
Priority date: 2021-12-20
Filing date: 2022-12-09
Publication date: 2023-06-29
Also published as: FR3130525A1

Abstract

The invention relates to a portable hair-styling appliance (1) comprising a built-in blower module (6) which is designed to generate an air flow intended to be projected towards the hair of a user, the blower module comprising two axial fans (8, 9) with blades which are mounted in a counter-rotating manner along coincident axes of rotation, and at least one motor (12, 13) for actuating the fans so that they rotate in opposite directions, and a porous medium (27) arranged between said fans. Hair-styling appliances.

Description

STYLING DEVICE COMPRISING AN IMPROVED BLOWER MODULE WITH CONTRAROTATIVE PROPELLERS AND INTERPOSED POROUS MEDIA

TECHNICAL AREA

The present invention relates to the general technical field of hairdressing appliances, for example for domestic use, and more specifically to the field of portable hairdressing appliances designed to blow a flow of air in order to dry and / or facilitate the hair shaping.

PRIOR TECHNIQUE

[0002] The invention relates more specifically to a portable hairdressing device comprising an on-board blower module designed to generate a flow of air intended to be projected by the hairdressing device in the direction of a user's hair.

[0003] Hairdressing appliances are known, for example of the hair dryer or hand-held airbrush type, comprising a gripping handle and a blowing head, through which a forced air flow generated by a module blower embedded in the device can be directed at the hair of a user or a user.

[0004] These known hairdressing devices, if they give overall satisfaction, are nonetheless perfectible. In particular, there is a strong need to obtain hairdressing appliances of ever smaller size, but whose aeraulic performance and in terms of controlling noise pollution are nonetheless optimal. In fact, reducing the size of hairdressing appliances generally leads to a very significant reduction in their aeraulic performance, unless measures are implemented to improve aeraulic performance, which in turn tends to increase the noise generated by the devices in operation. DISCLOSURE OF THE INVENTION

[0005] The objects assigned to the invention therefore aim to provide a response to the above-mentioned needs and problems, and to propose in particular a new portable hairdressing device which has a small footprint while offering a very good compromise in terms of performance. , both in terms of ventilation and in terms of controlling the noise generated by the device in operation.

Another object of the invention aims to provide a new particularly robust and reliable portable hairdressing device.

Another object of the invention aims to provide a new portable hairdressing device of particularly simple construction, and the manufacture of which is relatively easy and with controlled costs.

[0008] The objects assigned to the invention are achieved with the aid of a portable hairdressing appliance comprising an on-board blower module designed to generate a flow of air intended to be projected by said hairdressing appliance in the direction of the hair. of a user, said apparatus being characterized in that said blower module comprises:

- two axial propellers with blades, called upstream propeller and downstream propeller, which are mounted counter-rotating according to coincident axes of rotation, and at least one motor for actuating said propellers in rotation in opposite directions, and

- a porous medium arranged between said helices.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the invention will appear and emerge in more detail on reading the description given below, with reference to the accompanying drawings, given solely by way of illustrative and non-limiting examples, among which :

- Figure 1 illustrates, in a side view, an embodiment of a hairdressing device according to the invention in which the device constitutes a "multi-purpose" device. In Figure 1, the hairdressing device is illustrated in an operating configuration in "hair dryer"mode; - Figure 2 illustrates the hairdressing device of Figure 1 in a front view;

- Figure 3 illustrates, in a side view in sagittal section l-l (see Figure 2), the hairdressing device of Figures 1 and 2;

- Figure 4 illustrates, according to another front view, the hairdressing device of Figures 1 to 3, illustrated in another operating configuration in "blowing hairbrush" mode;

- Figure 5 illustrates, in a side view in sagittal section l-l, the hairdressing device of Figure 4;

- Figure 6 illustrates schematically, in a top view in transverse section ll-ll (see Figure 1), part of the hairdressing device of Figures 1 to 5;

- Figure 7 illustrates schematically, in a top view in transverse section III-III (see Figure 1) between the propellers of the blower module, part of the device of Figures 1 to 5. A detail of the porous medium , which here forms a grid, is shown enlarged so as to highlight the mesh of the grid;

- Figure 8 illustrates schematically, in a partial perspective view in sagittal section l-l, elements of the blower module of the device of Figures 1 to 5;

- Figure 9 schematically illustrates a design detail of the blower module of the hairdressing device of Figures 1 to 5;

- Figure 10 schematically illustrates, in a perspective view, the pair of propellers shown in Figures 8 and 9. The distance between the propellers, as shown in Figure 9, is not respected;

- Figure 11 illustrates, schematically, a downstream face of the upstream propeller illustrated in Figures 8 to 10, seen in a plane orthogonal to the axis of rotation of the upstream propeller;

- Figure 12 schematically illustrates an upstream face of the downstream propeller illustrated in Figures 8 to 10, seen in a plane orthogonal to the axis of rotation of the downstream propeller;

- Figure 13 schematically illustrates a detail of a design variant of the blower module of the hairdressing appliance of Figures 1 to 5; - figure 14 schematically illustrates, according to a perspective view, the pair of propellers of the design variant of figure 13. The distance between the propellers, as illustrated in figure 13, is not respected ;

- Figure 15 schematically illustrates a detail of another design variant of the blower module of the hairdressing device of Figures 1 to 5;

- figure 16 schematically illustrates, according to a perspective view, the pair of propellers of the design variant of the propellers of figure 14. The distance between the propellers, illustrated in figure 14, is not respected;

- Figure 17 illustrates, in a side view, another embodiment of a hairdressing device according to the invention in which the single-use device constitutes a hair dryer. The protective grille for the air inlet openings has been omitted;

- Figure 18 illustrates, in a sagittal sectional view, the apparatus of Figure 17;

- Figure 19 illustrates schematically, in a partial perspective view in sagittal section, certain elements of the hairdressing device of Figures 17 and 18. The upstream propeller has nine blades, while the downstream propeller has eight blades .

BEST WAY TO REALIZE THE INVENTION

The hairdressing device 1 according to the invention is designed to be grasped and manipulated by hand. It is therefore a portable, manual hairdressing device, preferably intended for use in a domestic setting by a user (woman or man) without specific professional skills in hairdressing. Preferably, the hairdressing device 1 is designed so that the user uses the hairdressing device 1 on himself, that is to say on his own hair. However, it is perfectly possible for the hairdressing device 1 to be designed for use by the user on the hair of a third person (or other user).

[0011]According to a variant, implemented in the embodiment illustrated in particular in FIGS. 1 to 5, the hairdressing device 1 can constitute a "multi-purpose" device, designed and configured to operate according to at least two modes. different blowing modes and typically comprising a control mechanism for controlling the passage of the hairdressing appliance from one of the blowing modes to another of the modes of blowing. For example, such a “multi-purpose” device could thus be designed and configured to be used alternately by a user according to a “hair dryer” mode (figures 1 to 3) and according to a “blowing hairbrush” mode (figures 4 and 5). According to a variant, implemented in another embodiment illustrated in FIGS. 17 to 19, the hairdressing device 1 can constitute a hair dryer (or hair dryer), which allows a user to dry his (or ) wet or damp hair by blowing in the direction of the hair with a flow of forced, hot or cool air, and to facilitate shaping of the hair. According to another variant, the hairdressing device 1 can constitute a blowing hairbrush, comprising a means of mechanical engagement of the hair, such as bristles, barbs, teeth, etc. The invention is however not limited to these variants and specific embodiments, and it is entirely possible that the hairdressing appliance 1 forms any other portable hairdressing appliance endowed with a function involving the blowing of a flow of air in the direction of a user's hair. For the sake of simplicity, the elements which are identical or similar to the two particular embodiments illustrated in the figures are designated, in the latter, by identical references.

The hairdressing device 1 advantageously comprises a handle 2 (or handle) by which the device 1 is intended to be held manually for use. The handle 2 thus forms a manual gripping member, intended to be grasped by the user to handle the hairdressing appliance 1. Advantageously, the handle 2 is elongated, that is to say it extends mainly in a single direction of space, corresponding to a direction of longitudinal extension Di-Dr. In other words, the handle 2 has a slender, slender shape, so that it can be grasped with the whole hand by an adult user. The handle 2 thus extends longitudinally between a first end 2A (or distal end) and a second end 2B (or proximal end) in said mean direction of longitudinal extension Di-Dr. Preferably, the distance separating the first and second ends 2A, 2B, corresponding to the length of the handle 2, is sufficient to allow all the fingers of one hand of a user to grasp the handle 2. For example, the handle 2 is generally tubular in shape (with, for example, a circular or elliptical middle section, constant or not), and is shaped and dimensioned to ensure a good grip by the user, in particular a "full hand" grip c' is to say by the palm and the fingers of the hand closing around the handle 2. [0013] The hairdressing device 1 advantageously comprises at least one air inlet 3, to draw ambient air from the external environment of the hairdressing device 1, and at least one air blower outlet 4, 23, which is in aeraulic communication with the air inlet 3 and through which a flow of (forced) air is intended to be blown outwards from the hairdressing device 1 in order to be projected in the direction of the user's hair. The hairdressing device 1 also advantageously comprises an internal duct placing said (at least one) air inlet 3 in air communication with said (at least one) air blower outlet 4, 23. Advantageously, the device hairdressing machine 1 comprises a blowing head 5, which is provided with said (at least one) air blowing outlet 4, 23, and which is thus designed to blow the air flow out of the hairdressing appliance 1 . Advantageously, the blowing head 5 extends the handle 2 from the first end 2A of the latter. Advantageously forming a unitary sub-assembly, the blowing head 5 is preferably integral with the handle 2, that is to say permanently connected to the latter, so that the handle 2 and the blowing head 5 are thus advantageously inseparable by the user. However, it remains conceivable that the blowing head 5 can alternatively be assembled to the handle 2 in a removable, temporary manner, so for example that the blowing head 5 can constitute an interchangeable accessory of the hairdressing device 1, according to the will of the user.

[0014] According to a variant, the blowing head s can be designed to receive, in a removable manner (for example, by snap-fastening, screwing, press-fitting, bayonet locking, etc.), an accessory or end piece (not shown) , such as for example a nozzle or a diffuser, at the level of the air blowing outlet 4, 23 (or of one and/or the other of the air blowing outlets 4, 23 in the event of a plurality of air blowing outlets), so as to modify the dimensions and/or shape of the useful outlet section of the air flow out of the blowing head 5 initially defined by the air blowing outlet 4, 23 ( and therefore, for example, the speed and / or the size of the air flow blown by the hairdressing device 1). Depending on the configuration of the accessory thus temporarily fixed to the air blowing outlet 4, 23 of the hairdressing appliance 1, and extending the blowing head 5 beyond the air blowing outlet 4, 23 , it is thus possible to achieve a certain number of particular styling effects. According to another variant, the blower head 5 of the hairdressing appliance 1 may, on the contrary, not be designed to receive such accessories or removable end pieces. The absence of parts that can be detached, disassembled from the blower head 5 by the user facilitates the use of the hairdressing appliance 1 and prevents the user from misplacing accessories. According to yet another variant, which combines the respective advantages of the two preceding variants, the air blowing outlet 4, 23 of the blowing head 5 of the hairdressing device 1 can advantageously be provided with a means for adjusting the dimensions and/or shape of the useful air passage section at the level of the air blowing outlet 4, 23, such as for example a nozzle, a diffuser or even an adjustable diaphragm, which adjustment means is integral and therefore not separable from the blowing head 5.

[0015] The hairdressing appliance 1 according to the invention also comprises a blower module 6 (or “motor-driven ventilation module” or “motor-driven fan unit”) on board, which is designed to generate the flow of air intended to be projected, blown, by the hairdressing appliance 1 in the direction of the user's hair. Arranged within the hairdressing device 1, the blower module 6 therefore has the function of sucking in ambient air external to the hairdressing device 1, via the air inlet 3 of the hairdressing device 1, to generate from this ambient air a flow of forced air intended to be blown out of the hairdressing device 1 via the said (at least one) air blowing outlet 4, 23 of the latter.

According to a variant, implemented in the embodiment illustrated in Figures 1 to 5 in particular, the blower module 6 extends the handle 2 from the second end 2B, so that the handle 2 is thus interposed between the blower module 6 on the one hand and the blowing head 5 on the other hand, between which the handle 2 extends longitudinally. Said blower module 6 can itself be extended by an electrical power cord (shown truncated), provided at its free end with an electrical connection plug. The blower module 6 of the hairdressing device 1 is therefore preferably remote from the blowing head 5 and the handle 2. It is thus possible to size the blower module 6 so as to generate an air flow of one high flow rate, economically, and without impacting the general size of the blower head 5 and the handle 2. In addition, such an arrangement of the blower module 6 advantageously makes it possible to better balance the weight of the hairstyle 1, by a distribution of the masses on either side of the handle 2, which contributes to the comfort of use of the device 1 for the user. Indeed, the masses are thus distributed on either side of his hand, which in particular facilitates his movements when he wishes to carry out hairdressing operations (brushing, etc.). According to another less advantageous variant (not illustrated), the blower module 6 could be arranged inside the handle 2. In these particular cases, the internal duct, which provides air communication between the air inlet 3 with said (at least one) air blower outlet 4 advantageously comprises an intermediate pipe portion 7 made or arranged inside the handle 2, to put the blower module 6 in air communication with the blower head 5 ( Figures 3 and 5) and thus guide the flow of air generated by the blower module 6 in the direction of the air blowing outlet(s) 4, 23. Advantageously, the internal duct then comprises at least one portion blowing pipe made or arranged inside the blowing head 5, and which is connected on the one hand to said intermediate pipe portion 7 and on the other hand to said air blowing outlet 4, or to the one and/or the other of said air blower outlets 4, 23. According to another variant, implemented in the embodiment illustrated in FIGS. 17 to 19, the blower module 6 can be arranged at the level of , or inside, the blow head 5.

[0017] Whatever the positioning adopted, the blower module 6 of the hairdressing appliance 1 according to the invention comprises two axial propellers 8, 9 with blades 10, 11 which are mounted to rotate along axes of rotation Ai-Ar, A2-A2' combined. In other words, the blower module 6 constitutes an axial (or "propeller") motor-driven fan unit, which is therefore designed to suck in air and propel the flow of air generated from the latter according to a mean direction substantially parallel to the axes of rotation A1-A1', A2-A2' of the propellers 8, 9, as illustrated schematically by arrows in the figures. The blower module 6 further comprises at least one motor 12, 13, and preferably two motors 12, 13, typically electric(s), to actuate said propellers 8, 9 in rotation around their axes of rotation A1-A1' , A2-A2' respectively. Typically, each of the propellers 8, 9 comprises a hub 14, 15 and a plurality of blades 10, 11 which extend radially from said hub 14, 15. Each of the blades 10, 11 thus extends radially from a foot of blade 10A, 11A which forms a blade end at which each blade 10, 11 is secured to the hub 14, 15, up to a blade tip 10B, 11B which respectively forms an opposite free blade end. Furthermore, each of the blades 8, 9 extends axially from a leading edge 10C, 11C to an opposite trailing edge 10D, 11D. More specifically, the axial propellers 8, 9 with blades 10, 11 of the blower module 6, called upstream propeller 8 and downstream propeller 9 (in consideration of the direction of circulation of the air drawn in and the air flow generated from the latter), are mounted counter-rotating along their respective axes of rotation Ai-Ar, A2-A2' combined, and said (at least one) motor 12, 13 is designed and configured to actuate said propellers 8, 9 in rotation in opposite directions (/.e. according to opposite directions of rotation). In what follows, the adjectives "upstream" and "downstream" may be omitted for the sake of brevity when reference is made to the propellers 8, 9 in general, without any direct link with their relative arrangement vis-à-vis the direction air circulation, so that the expression "upstream propeller 8 and downstream propeller 9" can therefore be replaced by the expression "propellers 8, 9". In operation, the upstream propeller 8 therefore draws in ambient air external to the hairdressing appliance 1 via the latter's air inlet 3 to generate an air flow (or "flow of 'primary air') in the direction of the downstream propeller 9, which sucks in said primary air flow to generate the air flow (or "secondary air flow") which will be blown out of the hairdressing appliance 1 via said (at least one) air blowing outlet 4, 23.

The implementation of a pair of counter-rotating propellers 8, 9 in accordance with the invention advantageously makes it possible to design a high-performance wind tunnel module 6 with high efficiency, with a size which nevertheless remains limited, in particular in one direction. radial relative to the axes of rotation A1-A1 ', A2-A2' of the propellers 8, 9. Indeed, unlike a wind tunnel module which would include only one and only one axial propeller, such a wind tunnel module 6 to contra-rotating axial propellers advantageously has greater efficiency, the downstream propeller 9 advantageously behaving as an active straightener making it possible to straighten the flow of air ("primary air flow") generated by the upstream propeller 8, while increasing again the air pressure within the blower module 6. At an identical diameter and speed of rotation, the implementation of a pair of counter-rotating axial propellers 8, 9 instead of a single and unique propeller axial thus advantageously makes it possible to increase the aeraulic performance by 40% to 50%. Thus, given the gain in ventilation performance provided by the implementation of a pair of counter-rotating propellers 8, 9, it becomes possible to dimension said propellers 8, 9 so as to obtain a blower module 6 that is relatively compact. If it has, as explained above, advantages in terms of airflow performance, the implementation of a pair of counter-rotating mounted axial propellers 8, 9 can however prove to generate a noise level more important than the implementation of a single axial helix. Indeed, in the case of counter-rotating propellers 8, 9, turbulence generated by the upstream propeller 8 can come into contact with the downstream propeller 9, which can be a source of amplification of the noise emitted. In addition, the use of two motors 12, 13 to each actuate one of the propellers 8, 9 in rotation, as preferentially envisaged below, also tends to increase the noise generated during the operation of the wind tunnel module 6 In order to effectively overcome this drawback in terms of sound emissions, the blower module 6 comprises, in accordance with the invention, a porous medium 27 which is arranged between said propellers 8, 9, so that said porous medium 27 is thus interposed axially in the air flow generated by the upstream propeller 8, upstream of the downstream propeller 9. Due to its porosity, said porous medium 27 is therefore permeable to air so that the air flow generated by the upstream propeller 8, and preferably all of said air flow, meets and passes through the porous media 27 to reach the downstream propeller 9. Advantageously, as illustrated in the figures, the porous media 27 occupies the entire section useful of the internal duct of the hairdressing device 1 between said propellers 8, 9. Quite interestingly, the implementation of such a porous medium 27 makes it possible to homogenize the air flow (or "flow of 'primary air') generated by the upstream propeller 8 and to reduce the impact of the turbulence generated by said upstream propeller 8. More specifically, the presence of the porous medium 27 makes it possible to absorb, or even to "break", the turbulence generated by the trailing edges 10D of the blades 10 of the upstream propeller 8. The vortices generated at the tip of the blade 10B of the blades 10 of the upstream propeller 8 are dissipated or "straightened" by the porous medium 27. This thus makes it possible to limit, if not to avoid, the interaction of this turbulence with the leading edges 11 C of the blades 11 of the downstream propeller 9. In doing so, the implementation of the porous media 27 allows a significant reduction in the airflow noise generated by the blower module 6 in operation. Furthermore, in the case where the wind tunnel module 6 comprises, as preferentially envisaged below, an upstream motor 12 and a downstream motor 13 to set the upstream 8 and downstream 9 propellers in rotation respectively, the porous medium 27 allows advantageously to filter and absorb part of the noise generated by the upstream motor 13 itself and transmitted by the air circulating in the internal duct of the hairdressing appliance 1 . The implementation in accordance with the invention of a blower module with counter-rotating propellers 8, 9 and such a porous medium 27 arranged between the propellers 8, 9 thus makes it possible to design a hairdressing device 1 which has a small footprint while offering excellent performance both in terms of aeraulics and in terms of controlling the noise generated by the device in operation.

It has been observed that the lower the porous media 27 has (or void ratio), the greater the reduction in noise (or acoustic power). On the other hand, a reduction in the porosity can lead to a reduction in the aeraulic performance of the blower module 6. In order to obtain a good compromise between, on the one hand, the increase in the pressure drops induced by the porous medium 27, which can a drop in airflow performance and, on the other hand, the limitation of airflow noise, the porous medium 27 preferably has a porosity which is between 30% and 90%, more preferably between 50% and 85%, and preference still equal to 66%. Such a preferential value advantageously makes it possible to reduce the noise by more than 2 dB(A).

Advantageously, the porous media 27 is positioned at equal axial distance from the upstream 8 and downstream 9 propellers. The porous media 27 is thus advantageously positioned interposed in the flow of air circulating from the upstream propeller 8 to the downstream propeller 9, as far as possible on the one hand from the trailing edges 10D of the blades 10 of the upstream propeller 8, and on the other hand from the leading edges 11C of the blades 11 of the downstream propeller 9. This contributes to improving the performance of the device 1 in terms of sound, insofar as the porous medium 27 constitutes, as such, an obstacle likely to contribute to the generation of noise when the propellers 8, 9 are rotating. Advantageously, the porous media 27 thus typically being along a mean extension plane which is oriented perpendicular to the axes of rotation A1-A1, A2-A2' of the propellers 8, 9, and which is positioned at axial equidistance from a mean trailing plane P _m f of the upstream propeller 8, in which are inscribed the trailing edges 10D of the blades 10 of the upstream propeller 8, and of a mean attack plane P _ma of the downstream propeller 9 , in which are respectively inscribed the leading edges 11 C of the blades 11 of the downstream propeller 9 (FIGS. 9, 15 and 19).

[0024] The effect in terms of homogenization of the air flow, and therefore of noise reduction, is optimal when the pores or meshes of the porous medium 27 are advantageously distributed in a homogeneous manner spatially vis-à-vis the air flow generated by the upstream propeller 8, and when their openings are of substantially identical shapes and dimensions.

[0025] Advantageously in terms of simplicity and low design cost, the porous media 27 forms (or at the very least comprises) a grid, as in the embodiments illustrated in the figures. The porous medium 27 therefore advantageously forms a generally two-dimensional element having two opposite faces, each oriented respectively opposite one of the helices 8, 9, and provided with a plurality of through holes constituting meshes distributed in a homogeneous manner and whose openings are of identical shapes and dimensions. The vortices, generated at the tip of the blade 10B of the blades 10 of the upstream propeller 8 as mentioned above, of a size greater than the grid mesh are thus "straightened" by the grid. Preferably, said grid is metallic, for example stainless steel, which gives it good mechanical robustness and facilitates its installation within the blower module 6. For example, as in the embodiments illustrated in the figures, said grid can be formed from an assembly of intersecting wires or bars. In this case, the grid can therefore optionally be a piece of canvas or fabric, that is to say in general any woven element having an alternation of threads, bars, bars, etc. and empty spaces that allow the flow of air to pass. Alternatively, the grid could be formed from a perforated plate by chemical cutting, plasma cutting or electroerosion for example.

[0026] Alternatively, the porous medium 27 can also be formed by, or comprise, a non-woven porous element, but always having an alternation of material and empty spaces, such as for example a foam. The porous media 27 can then have cells or pores which allow the flow of air to pass.

As mentioned above, the porous medium 27 advantageously forms a generally two-dimensional element. Thus, the porous medium 27 can take the form of a square, a rectangle, a disc, or any other geometric shape corresponding substantially to the internal section of the internal duct in which it is arranged. In other words, the thickness of the porous medium 27 is negligible compared to its two other dimensions: length or width, or even compared to its diameter. in the case where, as illustrated in the figures, the porous medium 27 forms a disk. It is important to select a porous medium 27 with a minimum thickness, in order to be able to bring the upstream 8 and downstream 9 propellers as close as possible, in order to optimize their aeraulic performance but also to improve the compactness of the hairstyle 1 .

Preferably, said grid has a mesh opening of between 0.1 mm and 0.8 mm, and even more preferably less than 0.7 mm, which makes it possible to optimize the effectiveness of the porous medium 27 in noise reduction material. Furthermore, it is advantageous for the meshes of the grid to be square in shape, as can be seen in particular in the enlargement proposed in figure 7, or of regular hexagonal shape (or "honeycomb" shape). Indeed, such mesh shapes allow a better regularity of the spatial distribution of the mesh openings, and therefore a better homogenization of the air flow passing through the grid coming from the upstream helix 8. For example, the porous media can form a grid with square meshes, with a mesh opening of between 1 mm and 8 mm, the grid being made up of an assembly of intersecting wires of circular section and of a diameter of between 0.02 mm and 0.2 mm , so that the grid thus has a porosity advantageously between 30% and 90% as mentioned above. In the case of such a grid with square meshes, the mesh opening therefore corresponds to the distance separating two warp threads or two weft threads.

[0029] Tests carried out using a square mesh grid formed from an assembly of wires with a diameter of 0.15 mm and having a mesh opening of 0.64 mm (i.e. a porosity of 66%) have demonstrated a reduction in the noise generated by the blower module 6 taken alone of more than 3 dB(A), and of more than 2 dB(A) when the blower module 6 is integrated into the hairdressing device 1, the grid being arranged at axial equidistance from the propellers 8, 9 as envisaged above.

Preferably, the propellers 8, 9 of the blower module 6 each have a diameter Dii, Di2 at the end of the blades 10B, 11B which is between 36 mm and 45 mm, and a height hi, h2 of blades 10, 11 which is between 3 mm and 10 mm. While the diameter Dii, Di2 at the end of blades 10B, 11B corresponds to an external diameter of said propellers 8, 9 in planes orthogonal to the axes of rotation Ai-Ar, A2- A2' respectively of the latter, said height hi, h2 of blades 10, 11 therefore corresponds to the maximum radial distance which separates the blade root 10A, 11A from the blade tip 10B, 11B of each of said blades 10, 11. Said height h1, h2 of blades 10, 11 therefore corresponds to a difference between a radius at the tip of the blade 10B, 11B and a radius at the root of the blade 10A, 11A of each of the blades 10, 11 (FIGS. 11 and 12). Such a particular dimensional choice in terms of diameters Dii, Di2 at the end of the blades 10B, 11B and heights hi, h2 of the blades 10, 11 advantageously contributes to the generation of an airflow with a high flow rate for a particularly bulky space. restriction of the blower module 6. It also turns out that, thanks to such a combination of preferential characteristics in terms of dimensioning of the counter-rotating propellers 8, 9 of the blower module 6, it is possible to obtain, in a particularly advantageous manner , an optimal generated air flow rate whether or not the air blowing outlet 4 of the blowing head 5 is equipped with an accessory, end piece or other means for adjusting the useful section of the blowing outlet d air 4 of the hairdressing device 1, as previously considered. In the event that, as will be described later in connection with the embodiment illustrated in FIGS. 1 to 5 in particular, the hairdressing device 1 comprises a plurality of air blowing outlets 4, 23 of different configurations, a such a combination of characteristics in terms of the design of the blower module 6 makes it possible to obtain, in a particularly advantageous manner, aeraulic performance, in particular in terms of flow rate, which remains optimal whatever the air blowing outlet 4, 23 selected by the user.

In order to further improve the aeraulic performance and the compactness of the blower module 6, it is particularly advantageous for the diameter Dii, Di2 at the end of the blades 10B, 11B of the propellers 8, 9 to be more preferably between 38 mm and 45 mm, and is even more preferentially equal to 40 mm±0.5 mm, the height h 1 , h 2 of blades 10, 11 being itself more preferentially comprised between 4 mm and 8 mm. Still with a view to further improving the aeraulic performance of the wind tunnel module 6, the blades 10, 11 of the propellers 8, 9 can advantageously be curved, as illustrated in the figures. In this case, the blades 10, 11 of the propellers 8, 9 each preferably have a maximum camber of between 0.1 mm and 0.6 mm, and preferably equal to 0.2 mm±0.05 mm. The maximum camber corresponds to the maximum curvature of the upper surface of the blades 10, 11, that is to say the maximum distance between the chord of the blades 10, 11 (imaginary line joining the edge leading to the trailing edge of the blades) and the surface of the upper surface. The length of the cord being advantageously between 10 mm and 22 mm, the maximum camber advantageously corresponds to a relative maximum camber of approximately 2% (that is to say of a value equal to approximately 2% of the length of the cord). the rope). It is moreover also advantageous in terms of aeraulic performance and compactness that the diameter Dii at the tip of the blades 10B of the upstream propeller 8 is preferably identical to the diameter Di2 at the tip of the blades 11B of the downstream propeller 9, as in the embodiments illustrated in the figures.

The maximum thickness of the blades 10, 11 of the propellers 8, 9 can vary along the height hi, h2 of the blades 10, 11. Advantageously, the maximum thickness of the blades 10, 11 can decrease from the base of blade 10A, 11A towards the blade tip 10B, 11 B of said blades 10, 11 along the height hi, h2 of the blades 10, 11. For example, the maximum thickness of the blades 10, 11 can be 2 mm on average along the height hi, h2 of the blades 10, 11, varying from 2.1 mm at the blade root 10A, 11A to 1.7 mm at the blade tip 10B, 11B. Such a choice in terms of The thickness of the blades 10, 11 advantageously makes it possible to obtain a good compromise between the weight of the propellers 8, 9 and the mechanical robustness of the blades 10, 11 of the latter. In addition, this advantageously makes it possible to keep a center of the masses closest to the center of the propellers 8, 9 and thus to facilitate the balancing of the latter, in particular in the case where the propellers 8, 9 are made by molding or injection -cast.

Advantageously, as in the embodiments illustrated in Figures 1 to 5 in particular, the axes of rotation Ai-Ar, A2-A2 'of the propellers 8, 9 of the blower module 6 are arranged coincident with, or at all less parallel, to the direction of longitudinal extension D1-D1' of the handle 2. This makes it possible in particular to simplify the design of the hairdressing device 1 and to improve its compactness when the blower module 6 is arranged at the level of the second end 2B of the handle 2, or even inside the latter.

Preferably, the propellers 8, 9 are made of rigid plastic material, to reduce the weight and the manufacturing cost. Alternatively, the propellers 8, 9 could be made of metal for example. Advantageously, the hairdressing device 1 is configured to ensure rotation of each of said propellers 8, 9 at a speed of rotation between 20,000 revolutions per minute (rpm) and 30,000 revolutions per minute. minute, preferably between 25,000 revolutions per minute and 30,000 revolutions per minute, and even more advantageously of the order of 28,000 revolutions per minute. As such, the hairdressing appliance 1 can comprise a control member for controlling the operation of the motor or motors 12, 13 of the blower module 6 rotating according to a rotational speed, constant or not, included in the speed ranges of rotation mentioned above, and this typically by modifying the average electrical supply voltage of the motor or motors 12, 13. It turns out that such a speed of rotation, advantageously chosen in combination with the aforementioned characteristics in terms of diameters Di 1 , Di2 at the end of the blades 10B, 11B and of height hi, F12 of the blades 10, 11 of the counter-rotating propellers 8, 9, makes it possible to obtain optimum aeraulic performance, in particular in terms of the flow rate of the air flow generated by the blower module 6. It is thus advantageously possible to obtain an air flow rate of between 40 m ³ /h and 65 m ³ /h. Such a speed of rotation also makes it possible to obtain a good compromise between the aeraulic performance, the level of noise generated and the service life of the motor or motors 12, 13 of the blower module 6. Preferably, the hairdressing appliance 1 is configured to ensure rotation of the propellers 8, 9 at substantially identical speeds of rotation. For example, an optimum operating point of the motor 12, 13, or of each of the motors 12, 13, of the blower module 6 could be defined by a speed of rotation of approximately 28,000 revolutions per minute, a motor power of 13 W at 28,000 revolutions per minute, under an electric current of 1 A, for an efficiency of 60%. While being included in the ranges of values mentioned above, the speed of rotation of each of the propellers 8, 9 can however optionally vary over time during use of the hairdressing device 1 . For example, the speed of rotation of each of the propellers 8, 9 may thus possibly fluctuate slightly around a target value of 28,000 revolutions per minute.

[0036] In particular for the abovementioned ranges and values of rotational speed of the propellers 8, 9, it proves advantageous in terms of aeraulic performance that the blades 10, 11 of the propellers 8, 9 are designed and configured so that: - the blades 10 of the upstream propeller 8 have a pitch angle at the blade root 10A of 45° ± 5°, a pitch angle in the middle of the blade of 41° ± 5° and a pitch angle at the tip of the blade 10B of 37° ± 5°,

- the blades 11 of the downstream propeller 9 having a pitch angle at the blade root 11A of 36° ± 5°, a pitch angle in the middle of the blade of 32° ± 5° and a pitch angle at the tip of the blade 11B of 28° ± 5°.

It therefore follows that the upstream 8 and downstream 9 helices are advantageously twisted. Advantageously, the value of the pitch angle of the blades 10, 11 of the upstream propeller 8 and of the downstream propeller 9 can therefore increase from the blade root 10A, 11A in the direction of the blade tip 10B, 11 B. The above pitch angles advantageously mean the angles formed between a plane orthogonal to the axis of rotation Ai-Ar, A2-A2' of the helix 8, 9 and a straight line passing through the edge of attack and the respective trailing edge of the blades 10, 11 respectively at the root of the blade 10A, 11B, in the middle of the blade and at the tip of the blade 10B, 11B. head losses generated by elements located upstream and/or downstream of the propellers 8, 9. Thus, in the case where the hairdressing appliance 1 constitutes a blowing hairbrush, or at the very least is configured to operate according to a “blowing hairbrush” mode, the values indicated above are particularly well suited. In the case where the hairdressing appliance 1 constitutes a hair dryer, or at the very least is configured to operate in a "hair dryer" mode, the induced pressure losses are generally lower, so that the more particular configuration following will be preferred:

- the blades 10 of the upstream propeller 8 have a pitch angle at the blade root 10A of 43° ± 5°, a pitch angle in the middle of the blade of 39° ± 5° and a pitch angle at the tip of the blade 10B of 35° ± 5°,

Advantageously, said (at least one) motor 12, 13 of the blower module 6 is a brushed DC electric motor. This type of engine has the advantage of being less expensive and easier to implement than a brushless direct current electric motor (or "self-driven synchronous machine with permanent magnets", or "brushless" in English). In addition, this type of motor is particularly well suited for rotating the propellers 8, 9 at a speed of rotation as mentioned above.

[0039] Preferably, as in the embodiments illustrated in the figures and as already mentioned previously, the blower module 6 of the hairdressing device 1 comprises two motors 12, 13, called upstream motor 12 and downstream motor 13 (in consideration of the direction of circulation of the air sucked in and of the flow of air generated by the blower module 6), to respectively actuate said upstream propeller 8 and said downstream propeller 9 in rotation. In what follows, the adjectives "upstream" and "downstream" may be omitted for the sake of brevity when reference is made to the motors 12, 13 in general, without a direct link with their relative arrangement vis-à-vis the meaning air circulation, so that the expression "upstream motor 12 and downstream motor 13" can therefore be replaced by the expression "motors 12, 13". Advantageously, as illustrated by example in the figures, the upstream 8 and downstream 9 propellers are respectively secured directly to respective motor shafts (or upstream rotor and downstream rotor) of the upstream 12 and downstream 13 motors, the axes of rotation of said motor shafts being coincident with the respective axes of rotation Ai-Ar, A2-A2 of said propellers 8, 9. Preferably, said motors 12, 13 are of identical designs and dimensions, which makes it possible in particular to simplify the design of the blower module 6 and to reduce the manufacturing cost. In particular, the upstream motor 12 and the downstream motor 13 are preferably both brushed direct current electric motors and are advantageously of identical dimensions.

[0040] Said motors 12, 13 are preferably arranged axially aligned, that is to say so that the downstream motor 12 is arranged facing the upstream motor 13, the axis of rotation of the motor shaft (or rotor downstream) of the downstream motor 13 being aligned, coincident, with the motor shaft (or upstream rotor) of the upstream motor 12. The upstream motor 12 and the upstream propeller 8 can thus be advantageously arranged axially aligned with the downstream motor 13 and the downstream propeller 9. This makes it possible in particular to improve the compactness of the blower module 6. According to an advantageous variant (not illustrated), said motors 12, 13 can be arranged axially aligned, with respect to each other, said motors 12, 13 being positioned between said propellers 8, 9, that is to say according to a relative arrangement "in opposition" of the motors 12, 13. According to another advantageous variant, implemented in the embodiments illustrated in the figures, said motors 12, 13 can be arranged axially aligned, one relative to the other, said propellers 8 , 9 being positioned between said motors 12, 13, that is to say according to a relative “head-to-tail” arrangement of the motors 12, 13. These two arrangement variants prove to be particularly advantageous in the case where, as considered above, said motors 12, 13 are brushed direct current electric motors. Indeed, motors of this type generally have a preferential direction of rotation. When the motors 12, 13 are chosen with the same preferential direction of rotation, such relative arrangements "in opposition" or "head to tail" allow counter-rotating rotation of the propellers 8, 9, each of the motors 12, 13 rotating according to its preferred direction of rotation. The efficiency of the motors 12, 13 is thus optimized. The so-called "head to tail" variant, in which the motors 12, 13 are arranged axially aligned, the propellers 8, 9 being positioned between the motors 12, 13, is even more advantageous insofar as such an arrangement also allows in particular to easily ensure an optimal relative arrangement of the propellers 8, 9 in terms of distance d, such as the latter will be discussed later. Such an arrangement also allows an arrangement of the air inlet 3 of the hairdressing device 1 at least partly laterally around the upstream motor 12, which makes it possible to improve the compactness of the hairdressing device 1, as well as to improve the cooling of the upstream motor 12, as will also be discussed later.

[0041] Alternatively, the wind tunnel module 6 could comprise only a single motor and a bevel gear mechanism, for example, to allow simultaneous and counter-rotating rotation of the propellers 8, 9 using this single motor. Such a design would nevertheless be more complex and more expensive to implement, and furthermore less advantageous in terms of mechanical reliability and acoustically.

Advantageously, at least one of the hubs 14, 15 that each of the propellers 8, 9 respectively comprises is (at least partially) hollow, that is to say hollowed out, and at least one of the motors 12 , 13 is at least partially housed within the hollow hub 14, 15 of the corresponding propeller 8, 9. More advantageously still, said propellers 8, 9 each comprise a hub 14, 15 which is hollow, said motors 12, 13 being at least partially housed within said hubs 14, 15. in other words, as illustrated in the figures, at least part of the upstream motor 12 is housed within a recess of the hollow hub 14 of the upstream propeller 8, while at least part of the downstream motor 13 is respectively housed within a recess in the hollow hub 15 of the downstream propeller 9. The size of the blower module 6 along the axes of rotation Ai-Ar, A2-A2′ of the propellers 8, 9 is thus advantageously reduced. As such, one and/or the other (and therefore preferably both) of the propellers 8, 9, typically have a diameter at the root of the blade 10A, 11A which is (slightly) greater a respective outer diameter of the motor 12, 13 corresponding. For example, depending on the outer diameter of the motor 12, 13 concerned, the corresponding propeller 8, 9 may have a diameter at the root of the blade OA, 11A advantageously between 25 mm and 32 mm.

The number of blades 10, 11 that each of the propellers 8, 9 respectively comprise has an impact on the performance of the wind tunnel module 6. Indeed, the higher the number of blades 10, 11, the greater the quantity of mechanical energy of the motor 12, 13 transmitted to the air is significant. Nevertheless, too many blades 10, 11 leads, by construction, to the implementation of blades 10, 11 of too small dimensions, which tends to degrade the efficiency of the propellers 8, 9. Conversely, too many low blades 10, 11 would limit the performance of the propeller 8, 9 and would require a propeller 8, 9 of large dimensions. At the same time, it also proves interesting, in terms of acoustic performance, that the propellers 8, 9 advantageously comprise a different number of blades 10, 11, and even more advantageous than the numbers of blades 10, 11 of the propellers 8, 9 are chosen to be prime among themselves (that is to say that the number of blades 10, 11 are different, and that they do not admit any common divisor, if not unity). This prevents the blades 11 of the downstream propeller 9 from crossing the blades 10 of the upstream propeller 8 at the same time. The number of blades 10 of the upstream propeller 8 is moreover preferably greater than the number of blades 11 of the downstream propeller 9. The mean pitch angle of the upstream propeller 8 being advantageously greater than that of the downstream propeller 9, it is thus possible to design the propellers 8, 9 with similar axial dimensions and therefore to have a relatively symmetrical construction.

In view of the foregoing, the upstream propeller 8 thus advantageously has a number of blades 10 of between 5 and 11, and preferably equal to 9, while the downstream propeller 9 advantageously has a number of blades 11 between 3 and 10, and preferably equal to 8, said numbers of blades 10, 11 being preferably chosen to be relatively prime. By way of examples, FIGS. 6 to 12 schematically illustrate a particularly advantageous variant in which the upstream propeller 8 comprises nine blades 10 and the downstream propeller 9 comprises eight blades 11 . This variant is also implemented in the embodiment of the device 1 illustrated in Figures 17 to 19. Figures 13 and 14 schematically illustrate a variant in which the upstream propeller 8 comprises seven blades 10 and the downstream propeller 9 comprises six blades 11. FIGS. 15 and 16 schematically illustrate yet another variant, in which the upstream propeller 8 comprises five blades 10 and the downstream propeller 9 comprises four blades 11 . Yet another variant (not shown) in which the upstream propeller 8 would comprise five blades 10 and the downstream propeller 9 would comprise three blades 11 could be envisaged, although less preferential than the variants above.

Preferably, the propellers 8, 9 of the blower module 6 have respective strengths of less than 1, while being preferably greater than 0.9, and even more preferably equal to 0.95±0.01. Solidity (or "solidity coefficient") compares the area of a propeller disc which is occupied by solid components (i.e. the blades) and with the remaining area of the disc which is open to air circulation (i.e. not occupied by the blades). Increasing the strength of a propeller results in a better transfer of mechanical energy from the engine to the air sucked in by the propeller. In addition, a strength of less than 1 advantageously allows axial demolding of the propellers when the latter are manufactured by molding or by plastic injection, which simplifies the manufacture of the propellers 8, 9 and reduces the costs thereof. Conversely, a solidity greater than 1 would require the use of molds with drawer(s), which are more complex and expensive to implement, to manufacture said propellers 8, 9 by molding or by plastic injection (or injection molding) . The preferential choice of a strength of the propellers 8, 9 which is equal to 0.95 ± 0.01 advantageously makes it possible to ensure sufficient transfer of the mechanical energy from the motor or motors 12, 13 to the air sucked in by the propellers 8, 9, while remaining within the limits of the torque deliverable by the motor(s) 12, 13.

[0046] Advantageously, said at least one motor 12, 13 and the propellers 8, 9 of the blower module 6 are arranged within the internal duct which ensures, as mentioned above, the aeraulic communication of the inlet of air 3 of the hairdressing appliance 1 with said (at least one) air blowing outlet 4 of the latter. When the blower module 6 advantageously comprises two motors 12, 13, as in the embodiments illustrated in the figures, said motors 12, 13 and propellers 8, 9 are advantageously arranged within said internal duct. Alternatively, but less advantageously in terms of size and simplicity of design, the propellers 8, 9 could be arranged in the internal duct, the motor or motors 12, 13 being arranged outside the latter.

The blower module 6 thus preferably comprises at least one motor support for holding said (at least one) motor and said propellers 8, 9 in position inside said internal duct. In the preferential case where, as in the embodiments illustrated in the figures, the blower module 6 comprises two motors 12, 13, namely said upstream motor 12 and said downstream motor 13, the blower module 6 advantageously comprises a motor support upstream 16 and a downstream motor support 17, respectively designed and configured to ensure the maintenance in position of the upstream motor 12 and the upstream propeller 8, and of the downstream motor 13 and the downstream propeller 9, inside the duct internal of the hairdressing device 1. The upstream motor support 16 and the downstream motor support 17 can then form one and the same part, monolithic, or form separate parts, as in the embodiments illustrated in the figures. In what follows, the adjectives "upstream" and "downstream" may be omitted for the sake of brevity when reference is made to the engine mounts 16, 17 in general, with no direct link to their relative arrangement vis-à-vis the direction of air circulation, so that the expression “upstream motor support 16 and downstream motor support 17” could therefore be replaced by the expression “motor supports 16, 17”. Advantageously, as illustrated by example in FIGS. 3, 5, 6, 8, 18 and 19 in particular, the motor support(s) 16, 17 comprise a peripheral tubular wall 16A, 17A of circular section which defines an air duct portion, and one or more support arms 16B, 17B which extend inwardly of said air duct portion, between a first end from which the support arm(s) 16B , 17B are connected to the peripheral tubular wall 16A, 17A and a second opposite end connected to the motor(s) 12, 13 arranged inside said air duct portion. As such, the peripheral tubular wall 16A, 17A of the motor support(s) 16, 17 can advantageously contribute to forming the internal duct of the hairdressing appliance 1, so that the duct portion d air defined by the peripheral tubular wall 16A, 17A advantageously forms a portion of said internal duct. Advantageously, the engine support(s) 16, 17 may comprise a nacelle 16C, 17C, secured to the second end of the support arm(s) 16B, 17B and designed and configured to receive and hold within it the single engine or the one of said upstream 12 and downstream 13 motors. respectively mounted on the motor shafts of the upstream 12 and downstream 13 motors, can thus advantageously be shrouded radially respectively by an internal face of the peripheral tubular walls 16A, 17A of the upstream motor support 16 and of the downstream motor support 17.

Alternatively, according to a variant not shown, the motor support(s) 16, 17 could not include peripheral tubular wall(s) 16A, 17A of circular section such as envisaged above, and the blower module 6 could advantageously comprise in this case a tubular nozzle of circular section, inside which the motor(s) 12, 13 and the propellers 8, 9 would be kept arranged in position by one or more motor support(s) comprising support arms fixed to an internal face of the tubular nozzle. The tubular nozzle would then advantageously form in this case a radial fairing for each of said upstream 8 and downstream 9 propellers.

In any case, it proves to be advantageous in terms of aeraulic performance that the upstream 8 and downstream 9 propellers of the blower module 6 are preferentially streamlined, that is to say that the blower module 6 comprises a radial fairing (or upstream fairing and downstream fairing) to radially fair the upstream 8 and downstream 9 propellers. Indeed, the implementation of such a radial fairing makes it possible to advantageously limit the formation of vortices at the tip of the blade OB , 11 B of the blades 10, 11 of the propellers 8, 9. More specifically, it is preferable, as in the embodiments illustrated in the figures where the blower module 6 therefore comprises upstream and downstream fairings respectively formed by the peripheral tubular walls 16A, 17A of the upstream 16 and downstream 17 engine mounts, that the blower module 6 has a radial play of between 0.2 mm and 0.8 mm between the tip of the blade 10B, 11B of the blades 10, 11 of the propellers 8 , 9 and respective inner faces of said upstream and downstream fairings. For example, a good compromise between controlling the risk of formation of vortices at the tip of the blade 10B, 11B and the ease of design and manufacture of the blower module 6 can be obtained when said radial play is approximately 0.5 mm.

[0050] For example, as illustrated in Figures 3, 5, 7 and 8, the porous medium 27 can be advantageously held in position, in particular when it forms a grid, between the upstream helix 8 and the downstream helix 9 using a pair of cylindrical spacers 28A, 28B with a circular base which is arranged interposed between the upstream motor support 16 and the downstream motor support 17. Maintaining the porous media 27 firmly clamped between them, said spacers 28A, 28B can be screwed or clipped together. In the case where the porous medium 27 is flexible, devoid of its own rigidity (for example if the porous medium 27 is, or comprises, a piece of foam or fabric), the implementation of such spacers 28A, 28B can advantageously allow firmly hold the porous media 27 substantially planar, stretched across the internal duct of the hairdressing device 1. Alternatively, as illustrated by example in Figures 18 and 19, the porous media 27 can be held in position, in particular when it forms a grid, between the upstream propeller 8 and the downstream propeller 9 using a single cylindrical spacer 28 with a circular base which is arranged interposed between the upstream motor support 16 and the downstream motor support 17. Of course , other suitable technical means can alternatively be implemented to ensure effective maintenance of the porous media 27 in position between the helices 8, 9.

[0051] In the case (not shown) where the blower module 6 comprises a single and unique motor to drive the propellers 8, 9 in counter-rotating rotation, it is advantageous to provide that said single motor is then arranged in the internal conduit of the hairdressing device 1 upstream of said propellers 8, 9 (in consideration of the direction of air circulation inside the hairdressing device 1), and that the air inlet 3 of the device hairstyle 1 is arranged at least partly laterally around said single motor. In the more preferred case, illustrated in the figures, where the blower module 6 comprises two motors 12, 13, namely said upstream motor 12 and said downstream motor 13, which are arranged axially aligned (that is to say arranged according to an axial alignment), the propellers 8, 9 being positioned between the motors 12, 13 (“head-to-tail” arrangement), said motors 12, 13 and said propellers 8, 9 being arranged within said internal duct, it is mutually advantageous to provide that the air inlet 3 of the hairdressing appliance 1 is arranged at least partly laterally around said upstream motor 12 (FIGS. 3, 5, 17 and 18). Here, the term "at least partly laterally around said engine" and "at least partly laterally around said upstream engine 12" advantageously means the fact that the air inlet 3 is arranged at least partly facing the engine single motor or of the upstream motor 12 and in line with the axis of rotation of the motor shaft (or rotor) of the latter, and this following at least part of the axial periphery of said single motor or of said upstream motor 12. The air exterior can thus be sucked into the hairdressing appliance 1 via said air inlet 3 along an average suction direction which is substantially orthogonal to the axis of rotation of the motor shaft (or rotor) of said single motor or said upstream motor 12. Such an arrangement of the air inlet 3 of the hairdressing device 1 makes it possible to further reduce the overall size of the latter, and also makes it possible to cool said motor. Preferably again, said air inlet 3 is arranged laterally along substantially the entire axial periphery of said single motor or of said upstream motor 12, so as in particular to ensure optimum suction of the external air inside the hairstyle 1 and optimal operation of the blower module 6.

[0052] As such, as illustrated by example in Figures 3, 5, 8, and 17 to 19, the peripheral tubular wall 16A of the upstream motor support 16 may advantageously be pierced with at least one air intake 16D of air which is arranged at least partly laterally around the upstream motor 12, the air inlet 3 of the hairdressing device 1 being positioned opposite said air intake vent 16D. Even more advantageously, the peripheral tubular wall 16A of the upstream motor support 16 can advantageously be pierced with a plurality of air intake vents 16D, which are arranged in an evenly distributed manner along the perimeter of the peripheral tubular wall 16 , said air inlet 3 is arranged opposite said air intake vents 16D. Advantageously, as in the embodiment illustrated in FIGS. 1 to 5, the blower module 6 can comprise a casing 18, inside which are arranged the motor or motors 12, 13 and the propellers 8, 9, as well as the if necessary, said engine support(s) 16, 17, and which is secured to the second end 2B of the handle 2. Advantageously, an outer face of the casing 18 of the blower module 6 thus defines a portion of the outer casing of the device hairstyle 1, which extends another portion of outer envelope of the hairdressing device 1 respectively defined by an outer face of the handle 2. Alternatively, as in the embodiment illustrated in Figures 17 to 19, said housing 18 can define a rear portion of the head of blower 5, opposite a front portion of the blower head 5 which carries the air blower outlet 4 (FIGS. 17 and 18). The air inlet 3 of the hairdressing appliance 1 can then comprise at least one, and preferably several, opening(s) 19 made through the casing 18 of the blower module 6 and connected if necessary in aeraulic communication with the air intake vent(s) 16D of the upstream motor support 16. A protective grille 20 (omitted in FIGS. user safety. In the event that the blower module 6 would be arranged inside the handle 2 or inside the blowing head 5, and not at the level of the second end 2B of the handle 2, the input of air 3 of the hairdressing device 1 could alternatively comprise one or more openings made through an outer face of the handle 2, or respectively through an outer face of the blower head 5.

[0053] Advantageously, the blower module 6 of the hairdressing appliance 1 can comprise a downstream static rectifier to further straighten the air flow downstream of the downstream propeller 9 and thus improve the performance of the blower module 6. For example, as in the embodiments illustrated in the figures and in particular in FIG. 6, such a downstream static rectifier can be carried by the downstream motor support 17, and be advantageously formed, at least in part, by support arms 17B of the downstream motor 13, the latter advantageously having a concave face portion oriented opposite the direction of rotation of the downstream propeller 9. Alternatively, the downstream static rectifier could be independent, separate, from the motor support(s) ( s) 16, 17 and include, for example, fins arranged immobile within the internal duct for aeraulic communication of the air inlet 3 with the air blowing outlet(s) 4, 23 of the hairdressing appliance 1 .

[0054] To further improve the performance of the blower module 6 in terms of sound emissions, while nevertheless maintaining a flow rate of air flow generated by the blower module 6 which is quite satisfactory, certain additional technical measures, which will be detailed below, can be advantageously implemented, each taken independently or preferably in combination. These technical measures are particularly advantageous in the preferential speed ranges of the upstream 8 and downstream 9 propellers mentioned above.

Preferably, the blades 10, 11 of at least one of the propellers 8, 9 of the wind tunnel module 6 are distributed in a non-equidistant manner radially, that is to say in a non-equidistant manner around the axis of rotation Ai-Ar, A2-A2' of said propeller 8, 9, so that the radial spacing of the blades 10, 11 of said propeller 8, 9 is therefore not constant. More preferably still, the blades 10, 11 of each of the propellers 8, 9 are distributed in a non-equidistant manner radially, that is to say in a non-equidistant manner around the axes of rotation A1-A1', A2-A2 'respective of said propellers 8, 9. The use of non-equidistant blades on the circumference of the hub 14, 15 of at least one of the propellers 8, 9, and preferably of each of the propellers 8, 9, advantageously allows reduce the amplitude of the lines at the blade pass frequency (BPF) and its harmonics. The acoustic disturbance can thus be advantageously reduced insofar as the line of high amplitude at the frequency of passage of the blades is thus replaced by several lines of lesser amplitude. Furthermore, in the case where the blower module 6 comprises support arms 17B for the downstream motor 13 and/or a downstream static rectifier, arranged downstream of the downstream propeller 9, the implementation of blades 11 not equidistant radially for the downstream propeller 9 advantageously makes it possible to reduce the acoustic disturbance caused by any whistling linked to the frequency of passage of the blades 11 of the downstream propeller 9 opposite the support arms 17B of the downstream motor 13 and/or of the downstream static rectifier. It is nevertheless desirable to maintain a positioning of the center of gravity of the propeller 8, 9 concerned, or of each of the propellers 8, 9 if necessary, on the axis of rotation A1-A1', A2-A2' of the propeller 8, 9, in order to guarantee good balancing of the propeller 8, 9 in rotation, which is favorable in terms of mechanical reliability and control of the vibrations and noise generated by the blower module 6. This is why, in the preferred variant described above where the upstream propeller 8 and the downstream propeller 9 respectively comprise nine and eight blades 10, 11 (FIGS. 6 and 8 to 11, 17 and 18 in particular), the upstream propeller 8 shows three equal angular sectors each comprising three blades 10 of different profile chord lengths (or widths) (namely advantageously a blade 10 of a reference chord length, a blade 10 of a chord length equal to said reference chord length increased by 10%, and a blade 10 with a chord length equal to said reference chord length decreased by 10%). The downstream propeller 9 has for its part four equal angular sectors each comprising two blades 11 of different chord length (namely advantageously a blade 11 of a chord length equal to a reference chord length increased by 10%, and a blade 11 of a chord length equal to said reference chord length minus 10%). The profile chord of a blade is an imaginary straight line that connects the leading edge to the trailing edge of a blade. Such a design can also apply mutadis mutandis in particular to propellers comprising four or six blades 10, 11.

In order to prevent turbulence generated at the trailing edge 10D of the blades 10 of the upstream propeller 8 attacking the downstream propeller 9 at the same time at the blade roots 11A and at the blade tips 11B, each of the blades 10 of the upstream propeller 8 preferably has a generatrix curvature which is in the opposite direction to a respective generatrix curvature of each of the blades 11 of the downstream propeller 9 (FIGS. 8 and 9). This advantageously makes it possible to reduce the frequency peak linked to an interaction between turbulence created at the trailing edges 10D of the blades 10 of the upstream propeller 8 and the leading edges 11A of the blades 11 of the downstream propeller 9. The generated noise is thus reduced.

It has been observed that the axial distance between the two propellers 8, 9 can have an impact on the ventilation noise generated, but also on the ventilation performance. As such, and to obtain a good compromise between noise reduction and obtaining good aeraulic performance, the propellers 8, 9 of the wind tunnel module 6 are preferably arranged so that the mean leakage plane P _m f of the the upstream propeller 8 is arranged at a distance d of between 5 mm and 10 mm, preferably between 6 mm and 10 mm, and more preferably still equal to 8 mm, from the mean plane of attack P _ma of the downstream propeller 9 (figures 9, 13 and 15). Beyond these ranges of values, the acoustic impact is certainly reduced, but the aeraulic performances are likely to be degraded.

Advantageously, the blower module 6 may include vibration damping means of the motor or motors 12, 13, such as in particular vibration absorption means. For example, as in the embodiments illustrated in the figures, the upstream engine support 16 and the downstream engine support 17 can be, one and/or the other provided with one or more shims 16E, 17E in an elastically deformable material (for example in elastomer, also called "silent bloc”) arranged between the engine 12, 13 and the corresponding engine mount 16, 17, for example within the respective nacelles 16C, 17C of the engine mounts 16, 17 (FIGS. 8 and 19).

[0059] Preferably, the hairdressing device 1 further comprises an electric heating element 21 to heat the air flow generated by the blower module 6 and blown outwards by said (at least one) blowing outlet. air 4. The electrical heating element 21 can be formed by any suitable electrical heating means, based on any technology for converting electrical energy into thermal energy. Preferably, the electric heating element 21 uses Joule effect heating, it being understood that the invention is not limited to a particular heating technology, provided that the electric heating element 21 is integrated into the hairdressing device 1 and powered electrically. For example, the electrical heating element 21 comprises at least one electric heating resistor formed of a winding of metallic conductor wires (not illustrated in the figures, for example in nichrome) around an insulating core (for example in mica), which has for example a cruciform section. As illustrated in Figures 3 and 5, the electric heating element 21 can be permanently embedded inside the handle 2 of the hairdressing device 1, advantageously inside the intermediate pipe portion 7 of the internal pipe of the hairdressing appliance 1, so as to be thus interposed in the air flow, downstream of the blower module 6 with respect to the direction of air circulation (FIGS. 3 and 5). Alternatively, the electrical heating element 21 could be arranged inside the blowing head 5 (Figure 18).

As mentioned above, and as in the embodiment illustrated in Figures 1 to 5 in particular, the hairdressing device 1 can advantageously constitute a "multi-purpose" device, designed and configured to operate according to at least two modes of different blowing modes and typically comprising a control mechanism 22 for controlling the passage of the hairdressing appliance 1 from one of said blowing modes to another of said blowing modes.

The hairdressing appliance 1 can then comprise a plurality of air blowing outlets 4, 23, namely at least a first air blowing outlet 4 and a second air blower outlet 23 which are distinct from each other, and an air direction member 24 which is movably mounted at least between:

- a first air direction configuration in which the air direction member 24 directs the air flow generated by the blower module 6 towards the first air blowing outlet 4 according to a first of said blowing modes (Figures 1 to 3), and

- a second air direction configuration in which the air direction member 24 directs the air flow generated by the blower module 6 towards the second air blowing outlet 23 according to a second of said blowing modes (Figures 4 to 5), the control mechanism 22 being connected to the air direction member 24 to control each passage of the air direction member 24 from one to the other of said first and second air direction configurations.

[0062] For example, as in the embodiment illustrated in the figures, the control mechanism 22 can be a push-push button mechanism 22A, the button 22A of the control mechanism 22 then being preferably mechanically connected to the control member. air direction 24 to mechanically transform each movement of the button 22A under the effect of a push exerted on the button 22A, typically by a finger of the user, into a movement of the air direction member 24 of towards each other of said first and second air direction patterns.

Still as in the embodiment illustrated in particular in Figures 1 to 5, such a "multi-purpose" device can be more specifically designed and configured to be able to be used alternately by a user according to a "hair dryer" mode. (first blowing mode/first air blowing outlet 4, figures 1 to 3) and according to a “blowing hairbrush” mode (second blowing mode/second air blowing outlet 23, figures 4 and 5) .

[0064] As such, as illustrated in Figures 1 to 5, the blower head 5 of the hairdressing appliance 1 can advantageously comprise a housing 25 which carries the first air blower outlet 4. As illustrated in FIG. 2 in particular, the first air blowing outlet 4 may have an opening of generally oblong, elongated shape, to blow the flow of air out of the hairdressing appliance 1 in the form of an air knife. Alternatively, the first air blow outlet 4 could have, for example, an opening of generally circular shape to blow the air flow in a substantially cylindrical or frustoconical shape. The blower head 5 of the hairdressing appliance 1 can also advantageously comprise a working element 26 (or “plateau” or even working “pad”) which carries the second air blowing outlet 23 and which comprises a mechanical engagement element 26A of the hair, able to interact mechanically with the user's hair in such a way as to brush it, to style it and/or even to comb it. Typically, the mechanical hair engagement member 26A may comprise a plurality of bristle rows or strips and/or brush bristles (FIGS. 1 and 3-5).

Advantageously, the second air blower outlet 23 may comprise a first air blower outlet portion 23A and a second air blower outlet portion 23B, separate from each other and positioned on either side of the mechanical engagement element 26A of the hair (FIG. 4), the first and second air blowing outlet portions 23A, 23B being preferably shaped and configured to blow the air flow in direction of the mechanical engagement element 26A of the hair. Advantageously, the working element 26 can be mounted for rotation relative to the handle 2, while the housing 25 of the blowing head 5 which is mounted fixed, immobile, relative to the handle 2. More precisely, as in the mode embodiment illustrated in the figures, the working element 26 can be mounted for rotation, pivoting, relative to the handle 2 in a predetermined angular range along an axis of rotation (not shown) between at least a first angular position in which the flow of air is intended to be blown out of the hairdressing device 1 via the first air blowing outlet portion 23A, and at least one second angular position, distinct from the first angular position, in which the air flow is intended to be blown out of the hairdressing appliance 1 via the second air blowing outlet portion 23B. Preferably, the axis of rotation of the working element 26 with respect to the handle 2 is parallel to, or coincides with, the direction of longitudinal extension Di-Dr of the handle 2, as in the embodiment illustrated in the figures. (Figures 1 to 5 in particular). The working element 26 is therefore capable of occupying a plurality of different angular orientations (or positions) relative to the handle 2, by pivoting around the axis of rotation of the working element 26, in a predetermined and advantageously limited angular range. The working element 26 has a certain latitude of rotation around its axis of rotation, and is therefore capable of being able to pivot, oscillate, relative to the handle 2 in said predetermined angular range, while blowing the flow of air out of the hairdressing appliance 1 by one and/or the other of the first and second air blowing outlet portions 23A, 23B carried by the working element 26. Thus, the interaction between the hair of the user and the mechanical engagement element 26A of the hair of the working element 26 may cause the working element 26 to pivot relative to the handle 2 under the effect of a tensile force exerted by the hair of the user on the mechanical engagement element 26A of the hair. When the second blowing mode of the hairdressing appliance 1 is selected, this then has the effect of blowing the air flow selectively through one and/or the other of said air blowing outlet portions 23A, 23B according to the direction of brushing or styling the hair, and therefore according to the direction of pivoting of the working element 26 in the direction of one or the other of the first and second angular positions. In this way, the flow of air is advantageously always blown as close as possible to the hair of the user, from the root to the tip of the hair, without requiring any particular action or reflection on the part of the latter other than that to brush his hair using the hairdressing device 1 . The hairdressing appliance 1 thus makes it possible to easily obtain particularly satisfactory styling and hair shaping effects. Moreover, given the fact that only the working element 26 is mounted for rotation with respect to the handle 2 in this case, and not the whole of the blowing head 5, the hairdressing appliance 1 is particularly ergonomic. and easy to use, even by a user without special professional hairdressing skills.

Preferably again, the hairdressing device 1 can be designed and configured so that the working element 26 is capable of occupying a third angular position (FIGS. 4 and 5), which is angularly intermediate to the first and second angular positions, and in which the flow of air is intended to be blown out of the hairdressing appliance 1 simultaneously via the first and second air blowing outlet portions 23A, 23B carried by the work 26. Advantageously, the third angular position is a position angularly median to the first and second angular positions within the predetermined angular range. Even more advantageously, the third angular position is a rest position, the working element 26 comprising a return member, preferably elastic, provided to automatically return the working element 26 to the third angular position when the working element 26 occupies one or the other of the first and second angular positions. Thus, in the absence of force exerted on the working element 26 by interaction between the hair of the user and the mechanical engagement element 26A of the hair, the working element 26 advantageously returns by itself automatically in the third intermediate angular position. The force and amount of rotation of the working element 26 by interaction between the user's hair and the mechanical engagement element 26A of the hair of the working element 26 which will subsequently be necessary to reaching one or the other of the first and second angular positions is thus advantageously reduced, which further improves the ease and comfort of use of the hairdressing device 1 . For example, the return member may comprise a leaf spring (or leaf spring) working in flexion or a spring rod working in flexion.

As mentioned above, the design of the blower module 6 in accordance with the invention proves to be particularly advantageous in the case where the hairdressing device 1 constitutes a "multi-purpose" device and in particular a hairdressing device. 1 designed and configured to be able to be used alternately in a “hair dryer” mode and in a “blower blower” mode. Indeed, such a design makes it possible to obtain aeraulic performances, in particular in terms of flow, which remain optimal whatever the air blowing outlet 4, 23 used according to the blowing / operating mode selected by the user, while retaining a particularly limited size of the blower module 6, and therefore of the hairdressing appliance 1 .

POSSIBILITY OF INDUSTRIAL APPLICATION

The invention finds its industrial application in the design and manufacture of hairdressing appliances, for example for domestic use, and more specifically portable hairdressing appliances designed to blow a flow of air in order to dry and / or to facilitate the shaping of the hair.

Claims

34

Portable hairdressing device (1) comprising an on-board blower module (6) designed to generate a flow of air intended to be projected by said hairdressing device (1) in the direction of a user's hair, said blower module (6) comprising:

- two axial propellers (8, 9) with blades (10, 11), called upstream propeller (8) and downstream propeller (9), which are mounted counter-rotating along axes of rotation (Ai-Ai', A2-A2) merged , and at least one motor (12, 13) for driving said propellers (8, 9) in rotation in opposite directions, and

- a porous medium (27) arranged between said helices (8, 9), said hairdressing appliance (1) being characterized in that said porous medium (27) has a porosity of between 50% and 85%. Hairdressing device (1) according to the preceding claim, characterized in that the said porous medium (27) has a porosity equal to 66%. Hairdressing appliance (1) according to any one of the preceding claims, characterized in that the said porous medium (27) is positioned at equal axial distance from the upstream (8) and downstream (9) helices. Hairdressing appliance (1) according to any one of the preceding claims, characterized in that the said porous medium (27) forms a grid, preferably metallic. Hairdressing appliance (1) according to the preceding claim, characterized in that the said grid has a mesh opening of between 0.1 mm and 0.8 mm, and preferably less than 0.7 mm, the meshes of the grid being preferably of square shape or of regular hexagonal shape. Hairdressing device (1) according to any one of the preceding claims, characterized in that the said helices (8, 9) each have a 35 diameter (Dii, Di2) at the end of the blades (10B, 11B) of between 36 mm and 45 mm and a height (hi, h2) of the blades (10, 11) of between 3 mm and 10 mm. Hairdressing device (1) according to the preceding claim, characterized in that the said diameter (Dii, Di2) at the end of the blades (10B, 11B) of the propellers (8, 9) is between 38 mm and 45 mm, and is preferably equal to 40 mm ± 0.5 mm, said height

(Hi, h2) of blades (10, 11) preferably being between 4 mm and 8 mm. Hairdressing appliance (1) according to any one of the preceding claims, characterized in that it is configured to ensure rotation of each of the said propellers (8, 9) at a speed of between 20,000 revolutions per minute and 30 000 revolutions per minute, and preferably between 25,000 revolutions per minute and 30,000 revolutions per minute. Hairdressing appliance (1) according to any one of the preceding claims, characterized in that the said at least one motor (12, 13) is a brushed DC electric motor. Hairdressing device (1) according to any one of the preceding claims, characterized in that the blower module (6) comprises two motors (12, 13), called upstream motor (12) and downstream motor (13), for actuating respectively said upstream propeller (8) and said downstream propeller (9) in rotation. Hairdressing appliance (1) according to the preceding claim, characterized in that said motors (12, 13) are arranged axially aligned, said propellers (8, 9) being positioned between said motors (12, 13). Hairdressing device (1) according to the preceding claim, characterized in that it comprises an air inlet (3) and at least one air blowing outlet (4, 23), and an internal duct putting in aeraulic communication said air inlet (3) with said air blow outlet (4, 23), said motors (12, 13) and said propellers (8, 9) being arranged within said internal duct, said air inlet (3) being arranged at least partly laterally around the upstream motor (12).

3. Hairdressing appliance (1) according to any one of the preceding claims, characterized in that the blades (10, 11) of the propellers (8, 9) are curved, and each preferably has a maximum camber of between 0, 1 mm and 0.6 mm, and preferably equal to 0.2 mm ± 0.05 mm, each of the blades (10) of the upstream propeller (8) preferably having a generatrix curvature which is in the opposite direction to a respective generatrix curvature of each of the blades (11) of the downstream propeller (9).

4. Hairdressing appliance (1) according to any one of the preceding claims, characterized in that the upstream propeller (8) has a number of blades (10) of between 5 and 11, and preferably equal to 9, while that the downstream propeller (9) has a number of blades (11) comprised between 3 and 10, and preferably equal to 8, said numbers of blades (10, 11) being preferentially chosen to be prime among themselves.

5. Hairdressing appliance (1) according to any one of the preceding claims, characterized in that the blades (10, 11) of at least one of the propellers (8, 9), and preferably of each of the propellers (8, 9), are distributed in a radially non-equidistant manner.

6. Hairdressing device (1) according to any one of the preceding claims, characterized in that said helices (8, 9) have respective strengths of less than 1, while being preferably greater than 0.9, and more preferably still equal to 0.95 ± 0.01. /. Hairdressing device (1) according to any one of the preceding claims, characterized in that the helices (8, 9) are arranged so that a mean vanishing plane (P _m f) of the upstream helix ( 8) is arranged at a distance (d) of between 5 mm and 10 mm, preferably between 6 mm and 10 mm, and even more preferably equal to 8 mm, from a mean attack plane (P _my ) of the downstream propeller (9).