EP3958707A1

EP3958707A1 - Hairdryer

Info

Publication number: EP3958707A1
Application number: EP20728188.2A
Authority: EP
Inventors: Carlos Josè CEVA
Original assignee: GaMa Srl
Current assignee: GaMa Srl
Priority date: 2019-04-24
Filing date: 2020-04-22
Publication date: 2022-03-02
Anticipated expiration: 2040-04-22
Also published as: EP3958707B1; IT201900006306A1; WO2020217189A1; ES2952234T3; EP3958707C0

Abstract

A hairdryer (1) comprises an electric motor (2) provided with a stator (21), a rotor (22) with rotor windings (24), a commutator (4) fixed to the rotor (22) and connected to the rotor windings (24), and a couple of brushes (5) powerable by an electric current and abutting the commutator (4); a fan (6) interposed between the electric motor (2) and an air suction rear opening (31) and rotated by the electric motor (2) to generate a main airflow (F); filtering means (8) interposed between the fan (6) and the commutator (4) and comprising a first casing (9) defining a first chamber (11) for a filtering element (10) arranged for retaining powders/scraps of a material constituting the brushes (5); a second casing (15) defining a second chamber (16) to contain the commutator (4) and first ends (5a) of the brushes (5) and connected to the first chamber (11) through a first passage opening (12) of the first casing (9), that comprises a second passage opening (13) facing the fan (6); the second casing (15) comprises a third passage opening (17) facing the stator (21); the openings (12, 13, 17) allow the passage of a secondary airflow (A) generated by the fan (6), entering the second casing (15) and leaving the first casing (9) to convey the powders/scraps of material into the filtering element (10).

Description

Hairdryer

The present invention relates to hairdryer devices and in particular refers to a portable hairdryer provided with a commutator electric motor.

The known and widely used portable hairdryers on the market, intended for both professional and domestic use, are electrical devices equipped with an external casing commonly made of plastics provided with a handle and an air duct.

In the most common embodiment, an electric motor, a centrifugal or axial fan connected and rotated by the electric motor and one or more electric heating elements, in particular resistors or electric resistances, for heating the air are housed inside the hairdryer casing.

When the hairdryer is in use, i.e. when the electric motor is powered and an electric current passes through the electric heating resistances, the fan is rotated by the electric motor and generates inside the casing, more precisely in the air duct, an air flow which is sucked into the rear part of the hairdryer through a suction opening, flows towards the front part of the hairdryer and outflows from a delivery front opening or mouth. The airflow passes through the electric heating resistances which produce heat by Joule effect with the passage of current, thus the airflow heats up and outflows from the delivery mouth.

The hairdryer electric motor is generally of the commutator type, and comprises a stator integral with the casing and equipped with stator windings powered with direct or single phase alternating electric current, a rotor equipped with rotor or armature windings and rotatably positioned inside the stator and in axis therewith and a commutator or switch fixed to the rotor and engaged by a couple of brushes for supplying the rotor windings with direct or single-phase alternating electric current during the rotation of the rotor for the generation of the magnetic fields necessary for the operation of the motor. The rotor and stator are made of ferromagnetic material and the greater the power required to operate the fan to generate an airflow adapted to dry hair in a reasonably short time, the larger the dimensions.

The brushes are fixed and therefore slide on the commutator which rotates with the rotor and is formed by a plurality of overlapping copper strips. The brushes are typically made up of elongated elements, having cylindrical or prismatic shape, made of carbon or graphite - and, for this reason, commonly called "carbon brushes" - i.e. a material that ensures excellent electrical conductivity and a reduced coefficient of friction at the same time.

Since they abut the commutator with rotating blades, the brushes are subject to progressive consumption or wear which takes the form of the generation of carbon or graphite fine powders that diffuses and spreads in the air during the operation of the hairdryer, causing the pollution of the surrounding environment. Air pollution or contamination with carbon/graphite fine powders is all the more serious for professional operators and users, typically hairdressers, who are exposed to a polluted environment for the entire working day, with serious health risks in the medium and long term.

As is known, the problem of pollution of the environment with fine powders is increasingly felt, as fine powders of anthropogenic origin (industry, transport, combustion processes, etc.) are among the main causes of asthma and diseases of the respiratory and cardiovascular systems.

An object of the present invention is to improve the known portable hairdryers, in particular hairdryers provided with commutator electric motors provided with supplying and switching brushes made of carbon or graphite.

Another object is to provide a hairdryer which allows considerably reducing the emission and diffusion of carbon/graphite powders in the ambient air, generated by the consumption of the brushes during the operation of the hairdryer.

A further object is to provide a manageable and low weight hairdryer, having a simple and robust construction.

These and other objects are achieved by a hairdryer according to claim 1.

The invention can be better understood and implemented with reference to the attached drawings which illustrate exemplifying and non-limiting embodiments thereof, wherein: figure 1 is a rear view of the portable hairdryer according to the invention;

figure 2 is a section according to line II- II of figure 1, which illustrates in particular an electric motor with commutator and supply brushes, a fan and filtering means interposed between the fan and the supply brushes;

figure 3 is a section according to line III-III of figure 2;

figure 4 is a section similar to that of figure 2 which illustrates a variant of the hairdryer of the invention equipped with an electrostatic charge generator.

With reference to figures 1 to 3, a hairdryer 1 according to the present invention is illustrated which comprises an electric motor 2 which includes a stator 21, in particular provided with stator windings 23 powerable by electric current, a rotor 22 provided with rotor windings 24 and rotating inside the stator 2 around a main axis X, a commutator 4 or electric switch fixed to, and rotating with, the rotor 22 and electrically connected to the rotor windings 24 and a couple of brushes 5. The latter ones are powerable by electric current and arranged to abut the commutator 4 with a defined force so as to reverse an electrical supply of the rotor windings 24 to create the magnetic fields necessary for the operation of the motor. The hairdryer 1 also comprises at least one fan 6 interposed between the electric motor 2 and an air suction rear opening 31 of the hairdryer 1 and rotated about the main axis X by the electric motor 2 so as to generate at least one main airflow F directed to an air outflow front opening 32 of the hairdryer 1. The fan 6 is connected to the electric motor 2, in particular to the rotor 22, via a driving shaft 7 and is located upstream of the electric motor 2 with reference to a flow direction of the main airflow F. The fan 6, of the centrifugal or axial type and made for example of plastics, comprises a hub 26 connected to one end of the driving shaft 7 and from which a plurality of blades 28 departs.

The hairdryer 1 further comprises filtering means 8 interposed between the fan 6 and the aforementioned commutator 4 and brushes 5 and arranged to collect powders and/or scraps of a material with which the aforementioned brushes 5 are made, such powders, particles, scraps being generated during operation by the progressive consumption of the brushes 5 placed abutting, and therefore sliding on, the rotating commutator 4.

The brushes 5 are made of conductive electrical material with a low coefficient of friction, such as for example graphite, carbon powder, mixture of graphite and copper.

The filtering means 8 comprise a first casing 9, interposed between the fan 6 and the aforementioned commutator 4 and brushes 5, defining a first chamber 11, in particular of an annular shape, which extends around the driving shaft 7 and is adapted to receive and contain a filtering element 10 capable of retaining the powders and/or scraps of the brushes 5 material. The filtering element 10 is made of a material, for example non-woven fabric, of a known type. The volume of the first chamber 11 and of the filtering element 10 that fills it is such as to allow the effective collection of the entire quantity of powders and scraps generated by the consumption of the two brushes 5.

The first casing 9 comprises at least a first passage opening 12 facing the commutator 4 which allows the entry of the powders and/or scraps of the brushes 5 material into the first chamber 11.

A second casing 15 is provided around the commutator 4, connected to the first casing 9 and comprising a second chamber 16 which contains, and in particular completely encloses, the commutator 4 and at least first ends 5a of the brushes 5 which abut the commutator 4. The second chamber 16 encloses the space or volume around the commutator 4 in which the powders and/or scraps of material are generated by the progressive consumption of the brushes 5. The second chamber 16 is connected to the first chamber 11 through the first passage opening 12 to allow the powders and/or scraps of material to move into the first chamber 11 and be stably held by the filtering element 10. The first casing 9 further comprises at least a second passage opening 13 facing the fan 6 and the second casing 15 comprises at least a third passage opening 17 facing the stator 21. The first passage opening 12, the second passage opening 13 and the third passage opening 17 allow the passage of a secondary airflow A having an direction opposite the main airflow F, entering the second casing 15 (from the third passage opening 17) and leaving the first casing 9 (from the second passage opening 13), passing through the second chamber 16 and the first chamber 11, through the first passage opening 12, so as to convey and direct the powders and/or scraps of material generated at the commutator 4 into the filtering element 10.

For this purpose the hub 26 of the fan 6 is provided with a plurality of through axial holes 27 which connect the second passage opening 13 of the first casing 9 to an air suction area B interposed between the fan 6 and the suction rear opening 31 of the hairdryer 1 to allow the passage and the outflow of the secondary airflow A from the filtering means 8. As better explained in the description below, in the suction area B, and in particular at the hub 26 of the fan 6, with the rotation of the blades 28 of the fan 6 during the operation of the hairdryer 1 a localized negative pressure of air is generated which facilitates the exit of the secondary airflow A from the through axial holes 27 and more generally the passage of said airflow A through the second chamber 16 and the first chamber 11. At the same time, in the area or space between the filtering means 8 and the electric motor 2, in particular at the second casing 15 and the third passage opening 17, with the rotation of the blades 28 of the fan 6 a localized overpressure is generated which pushes the secondary airflow A inside the second chamber 16 and therefore in the first chamber 11.

Containment means 18 are provided for slidingly housing the brushes 5, each of which having an elongated shape and provided with the first end 5a which abuts the commutator 4 and a second end 5b which is opposite the first end 5a and abutted by an elastic element 19 capable of exerting a force or thrust for maintaining the first end 5a against the commutator 4, in particular when a length of the aforementioned brush 5 decreases due to wear. In more detail, the containment means comprise a couple of substantially opposite containment elements 18 connected to the second casing 15 and provided with respective elongated seats arranged to slidingly house the respective brushes 5 and opening into the second chamber 16.

The hairdryer 1 of the invention also comprises an external casing 3, for example made of plastics, equipped with a handle not shown and with an internal air duct 33 provided with the suction rear opening 31 and the outflow front opening 32, the aforesaid openings 31, 32 being located at the opposite ends of the same air duct 33.

The outer casing 3 is configured and sized to contain the electric motor 2, the fan 6, the filtering means 8 and the heating elements 34, of a known type and not described in detail. With particular reference to figures 1 and 2, the first casing 19 of the filtering means 8 and the external casing 3 form an annular passage 20 for the passage of the main airflow F and of the secondary airflow A which passes through the filtering means 8.

In operation, the rotation of the fan 6 driven by the electric motor 2 generates, in addition to a main airflow F inside the air duct 33 from the suction rear opening 31 to the outflow front opening 32, also a secondary airflow A through the second casing 15 and the first casing 9 and in particular from the second chamber 16, which surrounds and encloses the commutator

4 and the first ends 5a of the brushes 5, i.e. the volume in which the powders and/or scraps of material due to the progressive wear of the brushes 5, to the first chamber 11 which houses the filtering element 10. In this way, the powders and/or scraps of material are conveyed through the first passage opening 12 into the filtering element 10 where they remain trapped. The air leaving the first casing 9 through the second passage opening 13 and the through axial holes 27 of the hub 26 of the fan 6 is therefore filtered, i.e. free of powders and scraps of carbon, graphite, and the like that can disperse in the surrounding environment, and in particular in the place of use of the hairdryer 1.

It should be noted that the dimensions and volume of the first chamber 11 and of the filtering element 10 ensure the complete and effective collection of the entire quantity of powders and scraps generated by the complete consumption of the two brushes 5.

Thanks to the hairdryer 1 of the invention it is thus possible to considerably reduce and substantially eliminate the emission and diffusion into the ambient air of powders, particles and scraps of material, such as carbon/graphite, generated by the consumption of the brushes

5 during the operation of the hairdryer 1.

By virtue of the first casing 9 of the filtering means 8, which contains the filtering element 10, of the second casing 15, which encloses and contains the commutator 4 and the first ends 5a of the brushes 5, and of the secondary airflow A, which crosses both chambers 11, 16 defined by the aforementioned first and second casings 9, 15, it is in fact possible to effectively and completely collect and convey all the powders, particles and scraps of the brushes 5 material into the filtering element 10 where they are retained, avoiding their dispersion externally, i.e. in the air duct 33 in the main airflow F.

It should be noted that the filtering means 8 filter only the secondary airflow A and do not intercept and filter the main airflow F, which flows freely in the air duct 33, from the air suction opening 31 to the air outflow opening 32. In this way, a progressive occlusion of the filtering element 10, due to the accumulation of powders and scraps of material inside it, does not interfere with, and in particular does not reduce, the flow rate of the main airflow F generated by the fan 6.

It should also be noted that the introduction of the filtering means 8 and of the second casing 15, in addition to not causing an increase in the hairdryer 1 size, causes an almost negligible increase in its weight, so as not to compromise its handling and lightness.

With reference to figure 4, a variant of the hairdryer 1 of the invention is shown which differs from the embodiment described above and shown in figures 1-2, in that it comprises an electrostatic charge generator 35 connected to, and acting on, the filtering element 10 to cooperate in retaining the powders and/or scraps of the brushes 5 material inside the filtering element 10. In particular, the electrostatic charge generator 35 is arranged to release positive electric charges inside the filtering element 10, by means of a first emitter cable 36 which passes through the latter.

The electrostatic charge generator 35 comprises, for example, an ionizer of a known type and not described in detail, arranged to electrically charge the air-forming gas molecules and produce positive ions inside the filtering element 10, in particular by the first emitter cable 36.

The electrostatic charge generator 35 is also connected with a second emitter cable 37 to the heating elements 34, in particular comprising resistors or electrical resistances, to electrically charge the air-forming gas molecules and produce negative ions at the outflow front opening 32.

Claims

1. Hairdryer ( 1 ) comprising :

- an electric motor (2) comprising a stator (21), a rotor (22) provided with rotor windings (24) and rotating inside said stator (2) around a main axis (X), a commutator (4) fixed to, and rotating with, said rotor (22) and electrically connected to said rotor windings (24), and a couple of brushes (5) powerable by an electric current and abutting said commutator (4) with a defined thrust force so as to reverse an electrical supply of said rotor windings (24);

- at least one fan (6) interposed between said electric motor (2) and an air suction rear opening (31) of said hairdryer (1) and rotated about said main axis (X) by said electric motor (2) to generate at least one main airflow (F) directed to an air outflow front opening (32) of said hairdryer (1);

- filtering means (8) interposed between said fan (6) and said commutator (4) and said brushes (5) and comprising a first casing (9) defining a first chamber (11) extending around a driving shaft (7) and containing a filtering element (10) for retaining powders and/or scraps of a material constituting said brushes (5) and generated by consumption of said brushes (5) abutting said commutator (4);

characterized in that it comprises a second casing (15) defining a second chamber (16) adapted to contain said commutator (4) and at least first ends (5a) of said brushes (5) abutting said commutator (4) and connected to said first chamber (11) through at least a first passage opening (12) of said first casing (9), the latter further comprising at least a second passage opening (13) facing said fan (6), and said second casing (15) comprising at least a third passage opening (17) facing said stator (21), said passage openings (12, 13, 17) allowing the passage of a secondary airflow (A) generated by said fan (6), having a direction opposite said main airflow (F), entering said second casing (15) and leaving said first casing (9) passing through said second chamber (16) and said first chamber (11) so as to convey said powders and/or scraps of material generated at said commutator (4) into said filtering element (10).

2. Hairdryer (1) according to claim 1, wherein said fan (6) comprises a hub (26) connected to one end of said driving shaft (7) driven by said electric motor (2) and provided with a plurality of through axial holes (27) for the passage of said secondary airflow (A) from said first casing (9) to an air suction area (B) interposed between said fan (6) and said suction rear opening (31).

3. Hairdryer (1) according to claim 2, wherein said fan (26) is further configured to generate a localized negative pressure of air at said suction area (B) and a localized overpressure of air at said second casing (15) and at said third passage opening (17).

4. Hairdryer (1) according to any preceding claim, comprising an external casing (3) adapted to contain at least said electric motor (2), said fan (6) and said filtering means (8) and provided with said air suction rear opening (31) and with said air outflow front opening (32).

5. Hairdryer (1) according to claim 4, wherein said first casing (19) and said external casing (3) form an annular passage (20) for the passage of said main airflow (F) and of said secondary airflow (A) generated by said fan (6).

6. Hairdryer (1) according to any preceding claim, comprising an electrostatic charge generator (35) connected to, and acting on, said filtering element (10) to cooperate in retaining said powders and/or scraps of material inside the filtering element (10).

7. Hairdryer (1) according to claim 6, wherein said electrostatic charge generator (35) is arranged to release positive electric charges inside said filtering element (10).

8. Hairdryer (1) according to claim 6 or 7, wherein said electrostatic charge generator (35) comprises an ionizer arranged to electrically charge the air-forming gas molecules and produce positive ions.

9. Hairdryer (1) according to any preceding claim, comprising containment means (18) for slidingly housing said brushes (5), each brush (5) having an elongated shape provided with said first end (5a) and with a second end (5b) opposite said first end (5a) and abutted by at least one elastic element (19) adapted to exert a force for maintaining said first end (5a) against said commutator (4), in particular when a length of said brush (5) decreases due to wear.

10. Hairdryer (1) according to claim 9, wherein said containment means comprise a couple of containment elements (18) connected to said second casing (15) and provided with respective elongated seats arranged to slidingly house the respective brushes (5) and opening into said second chamber (16).

11. Hairdryer (1) according to any preceding claim, wherein said brushes (5) are made of one among graphite, carbon powder, mixture of graphite and copper.