Field of the invention

The present invention concerns a hair dryer and, more particularly, a hair dryer provided with an electric motor, preferably of brushless type.

Known art

Hair dryers are devices used to dry hair both at beauty salons or hairdressers and for domestic use (see document DE2742615).

Generally, known hair dryers comprise a “gun-shaped” body consisting of an upper element and a grip portion adapted for being grasped by a user.

The upper element, substantially cylindrical or truncated-cone shaped, extends along an axis and has, at the two ends, an air inlet opening and, at the opposite end, a front air outlet opening.

A motor and a fan, the latter operated by the aforesaid motor and able to generate a flow of air which crosses the upper element and comes out of the front opening, are generally present inside the upper element.

One or more electric resistances, for heating the flow of air generated by the fan, are arranged inside the upper element, at a predetermined distance with respect to the motor and the fan.

A small control unit, such as a printed electronic circuit which allows to control the electric motor and, consequently, the fan and electric resistance, is generally provided inside the grip portion.

The electric motor and resistance, as the electronic printed circuit, are powered by current and, for this purpose, a power cord connected to the aforesaid grip portion connects the aforesaid elements to the electric network.

Recently, thanks to commercial request linked to the demand for high energy efficiency products, the use of electric motors of the brushless types in hairdryers is spreading. The first big advantage relating to the application of such motors concerns the expected lifetime of the motor itself with respect to traditional electric motors. Moreover, the lack of brushes in brushless motors also eliminates the main source of electromagnetic noise present in other electric motors. The bulkiness of such type of motors is limited with respect to the power they can supply, but especially to the torque such motors can deliver. In terms of efficiency, brushless motors always operated in optimal performance conditions and have greater efficiency since they do not have to generate the rotor magnetic field. Moreover, brushless motors have low noisiness Brushless motors are driven by an electronic control unit such as an electronic control board.

The Applicant has observed that, especially in the professional sector, a hair dryer subjected to an intense and/or improper use can result in the clogging and/or closing of the air intake path or air outlet path. Such closing can also be only partial.

Indeed, the Applicant has observed that in case of intense use of the hairdryer, a given amount of hairs can be involuntarily sucked inside the hair dryer, thus settling around the rotation shaft of the fan, thus overloading the motor over time. Always in case of improper use of the hairdryer, the hairdresser can, involuntarily, obstruct the intake path by improperly grasping the hair dryer or obstruct the air outlet path by bringing the hair dryer too close to the customer’s head.

To date, there are no remedies to prevent such improper uses of the hair dryer, which can compromise the performance of the appliance over time or even cause it to break down. The Applicant has thus found the need to provide a new type of hair dryer with an electric motor, preferably of brushless type, which allows to promptly warn the user of an abnormal use thereof.

In particular, the Applicant has addressed the problem of warning the user of a clogging and/or closing, also only partial, of the air intake path or of the air outlet path of the hair dryer or of a decrease in its performance, for example due to the winding of hair involuntarily sucked inside the hair dryer around the rotation shaft of the fan.

Summary of the invention

Thus the invention, in a first embodiment thereof, concerns a hair dryer comprising a body provided with at least one upper element and a grip portion adapted to be grasped by a user and operatively connected to said at least one upper element; said upper element extending along an axis and having, at an end thereof, an air inlet opening and, at the opposite end, a front air outlet opening; said upper element comprising, in its inside:

- an electric motor; configured for being set at different speeds comprising a maximum speed setting;

- a fan, operated by said electric motor to produce an air flow passing through the upper element and coming out of the front opening;

- electric heating means for heating the air flow produced by the fan; said electric heating means being arranged at a predetermined distance from said electric motor and the fan;

- an electronic control board configured to drive the electric motor; characterized by comprising

- at least one emitter of visual and/or acoustic signal and/or a vibration, which is connected to said electronic control board;

- said electronic control board comprising at least one microprocessor configured to detect the power emitted by said electric motor and to control the emitter of visual and/or acoustic signal and/or a vibration to emit a visual and/or acoustic signal and/or a vibration whenever a decrease in electric power with respect to the rated electric power corresponding to the speed set is detected

This way, the user is immediately warned about the improper use of the hair dryer and/or about a decrease in performance due to other phenomena, such as the winding of hair on the motor shaft, thus allowing the user to promptly act by correcting his behavior or requesting maintenance of the hairdryer.

Preferably, the microprocessor configured for detecting the power emitted by said electric motor and controlling the emitter of visual and/or acoustic signal and/or a vibration to emit a visual and/or acoustic signal and/or a vibration whenever a decrease in electric power is detected with respect to the rated electric power at maximum speed.

For the purpose of the present invention, maximum speed is intended as the maximum speed of the motor at which the hair dryer can be set. Indeed, hairdryers can typically be set by the user on one, two, three or more different speeds. If, for example, the hair dryer can be set on three different speeds, the maximum speed of the motor corresponds to the highest speed between the three at which the motor can be set in use. Whenever the hair dryer has a single speed of operation, the maximum speed would correspond to the single operating speed.

In the aforesaid aspect, the present invention can have at least one of the preferred characteristics described hereunder.

Advantageously, the aforesaid at least one microprocessor is configured for detecting the power emitted by the electric motor and controlling the emitter of visual and/or acoustic signal and/or a vibration to emit a visual and/or acoustic signal and/or a vibration whenever a decrease in electric power equal to at least 30% of the rated electric power corresponding to the speed set is detected. Preferably, the microprocessor is configured for detecting the power emitted by the electric motor and controlling the emitter of visual and/or acoustic signal and/or a vibration to emit a visual and/or acoustic signal and/or a vibration whenever a decrease in electric power equal to at least 30% of the rated electric power at maximum speed is detected.

Preferably, the microprocessor is configured for controlling said emitter of visual and/or acoustic signal and/or a vibration to emit a visual and/or acoustic signal and/or a vibration whenever the electric circuit detects an electric power of less than or equal to 90 watts. Advantageously, the microprocessor is configured for controlling said emitter of visual and/or acoustic signal and/or a vibration to emit a visual and/or acoustic signal and/or a vibration whenever the electric circuit detects an electric power of less than or equal to 80 watts.

Conveniently, the microprocessor is configured for controlling the emitter of visual and/or acoustic signal and/or a vibration to emit at least one visual and/or acoustic signal and/or a vibration whenever the microcontroller detects an electric power of less than 50 watts, if the electric motor is set at a different speed with respect to the maximum speed.

Preferably, the microprocessor is configured for controlling the emitter of visual and/or acoustic signal and/or a vibration to emit at least one visual and/or acoustic signal and/or a vibration whenever the microcontroller detects an electric power of less than or equal to 45 watts, if the electric motor is set at a different speed with respect to the maximum speed.

Conveniently, the microprocessor is configured for detecting the electric power of the motor at preset time intervals.

Conveniently, the aforesaid preset time interval is greater than or equal to 10 sec. Conveniently, the aforesaid preset time interval is greater than or equal to 15 sec. Advantageously, the emitter of a visual and/or acoustic signal and/or a vibration comprises at least one led.

Preferably, the aforesaid at least one led is positioned on the upper element such as to be visible for the user.

Advantageously, the electric motor is a brushless motor.

Preferably, the electric motor is a single-phase brushless motor.

Alternatively, the electric motor is a three-phase brushless motor.

Further characteristics and advantages of the invention will become clearer in the detailed description of some preferred, but not exclusive, embodiments of a hair dryer according to the present invention.

Brief description of the drawings Such description will be stated hereunder with reference to the accompanying drawings provided by way of example only and thus not limiting, in which:

- figure 1 is a schematic side view of a hair dryer according to the present invention;

- figure 2 is a schematic view of a motor assembly with the electronic control board and the device emitting the visual signal of the hair dryer according the present invention; and

- figure 3 is a graph of the power loss of the motor of the hair dryer according to the present invention as the percentage of clogging of the back grid varies. Detailed description of embodiments of the invention

With reference to figures 1-3, a hair dryer according to the present invention is denoted by the numerical reference 1.

The hair dryer 1 shown in figure 1 has a body provided with at least one upper element 2 and a grip portion 3 adapted to be grasped by a user.

The upper element 2 extends along an axis X-X and has, at an end thereof, an opening 4 for the inlet of air and, at the opposite end, a front opening 5 for the outlet of air.

The upper element 2 comprises, in its inside: an electric motor 6; a fan, not directly shown in the figure, operated by the electric motor 6 to produce a flow of air which crosses the upper element 2 and comes out of the front opening 5.

Electric heating means, such as an electric resistance comprising at least two windings for heating the flow of air generated by the fan, are further present in a known way. The electric resistance is arranged at a predetermined distance from the electric motor 6 and the fan.

In particular, the electric motor 6 is of the brushless type and an electronic control board, which allows to drive the electric motor 6 and, consequently, the fan, is present in the upper element 2.

Preferably, the electric motor 6 is a single phase or three-phase brushless BLDC motor.

The electronic control board 7 comprises a series of electronic components, such as a microcontroller which controls the transistors and the switching of the current. The microcontroller is further configured for detecting the power delivered by the electric motor 6.

The hair dryer 1 further has an emitter of visual and/or acoustic signal and/or a vibration controlled by the microprocessor of the electronic control board 7.

The microcontroller is configured for controlling the emitter 8 of visual and/or acoustic signal and/or a vibration so that it emits a visual and/or acoustic signal and/or a vibration perceivable by the user whenever a decrease in electric power is detected with respect to the rated operating power In detail, the motor is configured for being set by the user at different operating speeds, for example a minimum speed, a maximum speed and one or more intermediate speeds.

A given rated operating power corresponds to each speed.

Thus, the electronic control board 7 is configured for controlling the emitter 8 of a signal so that it emits a signal perceivable by the user whenever a decrease in electric power is detected with respect to the rated operating power corresponding to the operating speed set.

Preferably, the electronic control board 7 is configured for controlling the emitter 8 of visual and/or acoustic signal and/or a vibration so that it emits a visual and/or acoustic signal and/or a vibration perceivable by the user whenever a decrease in electric power is detected with respect to the rated operating power at maximum speed.

In other words, according to some embodiments, the electronic control board 7 is configured for controlling the emitter 8 of a signal so that it emits a signal perceivable by the user only whenever a decrease in electric power is detected with respect to the rated operating power corresponding to the maximum operating speed.

In general, the microcontroller is configured for controlling the emitter 8 of visual and/or acoustic signal or a vibration so that it emits a visual and/or acoustic signal and/or a vibration perceivable by the user whenever a decrease in electric power of at least 30% of the rated electric power is detected.

Preferably, the microcontroller is configured for controlling the emitter 8 of visual and/or acoustic signal and/or a vibration so that it emits a visual and/or acoustic signal and/or a vibration perceivable by the user whenever a decrease in electric power of at least 30% of the rated electric power at maximum speed is detected. In particular, in case of an electric motor of the three-phase or single-phase brushless type, whose rated power is of about 120 W at maximum speed, the microcontroller is configured for controlling the emitter 8 of visual and/or acoustic signal and/or a vibration so that it emits a visual and/or acoustic signal and/or a vibration perceivable by the user whenever it detects an electric power of less than or equal to 90 W (watts), preferably 80W.

In other words, whenever the microcontroller detects that the electric power of the motor has dropped below 90W, preferably 80W or less, it controls the emitter 8 to emit a visual and/or acoustic signal and/or a vibration so that it emits the aforesaid signal and/or vibration.

The detection occurs according to regular or preset time intervals. Preferably, the time intervals within which the microcontroller detects the power of the motor 6 are all the same intervals. Preferably, the microcontroller detects the electric power of the motor at time intervals greater than or equal to 10 seconds.

Even more preferably, the time intervals within which the microcontroller detects the power of the motor 6 are all the same intervals. Preferably, the microcontroller detects the electric power of the motor at time intervals greater than or equal to 15 seconds.

In other words, the microcontroller detects the electric power of the motor every 15 seconds, whenever such electric power is less than a preset threshold, for example 80W, the microcontroller controls the emission of the visual and/or acoustic signal and/or vibration.

Whenever within the successive time intervals the microcontroller always detects an electric power lower than the threshold electric power, it will control the emitter 8 to emit a visual and/or acoustic signal and/or vibration and to continue on emitting the signal and/or vibration.

Vice-versa, whenever within the successive time intervals the microcontroller detects that the electric power of the motor has gone above the threshold electric power (e.g.: 80 W), it will control the emitter 8 to stop (not emit) the visual and/or acoustic signal and/or vibration.

The power values mentioned above refer to the threshold values for a motor operating at maximum speed. In the embodiments wherein the microcontroller is configured for controlling the signal emitter 8 so that it emits a signal perceivable by the user whenever an electric power decrease is detected with respect to the rated operating power corresponding to the operating speed set, the motor being able to be set at different speeds, the threshold powers are obviously different. In case in which, for example, the motor can be set at two different operating speeds, respectively a minimum and a maximum speed, and it is set by the user on the minimum one corresponding to a rated operating power of about 50 W, whenever the microcontroller should detect that the electric power of the motor should drop below a preset threshold, for example 45 W, the microcontroller would control the emission of the visual and/or acoustic signal and/or vibration.

An emitter 8 of visual signal placed on the upper element 2 in a position such as to be able to be seen by the user is present in the embodiment shown in the figures. Preferably, the emitter 8 of visual signal is a led directly connected to the electronic control board 7 through its rheophores. The emitter 8 of visual signal is placed such as to partially come out of the shell of the upper element 2.

Preferably, the emitter 8 of visual signal is placed such as to partially come out of the inner portion of the shell of the upper element 2.

The inner portion of the shell of the upper element 2 is to be intended as the one that, with hair dryer in use and grasped by the user, is substantially oriented towards and facing the face of the user.

The graphs of the power loss of the motor of the hair dryer according to the present invention as the percentage of clogging of the back grid or front outlet path thereof varies are shown in figure 3.

The percentage of clogging/closing of the air intake path of the hair dryer is illustrated in abscissa, respectively with a hair dryer that is fitted with a front delivery mouth or without.

The electric power detected by the microcontroller is instead illustrated in ordinate. The straight line denoted by the reference A denotes the rated power that is generally detected by the microcontroller under normal operation at maximum speed, 120 W in the specific case.

The straight line denoted by the reference B denotes the power setting limit under which the microcontroller controls the emission of the signal.

The dotted line denoted by the reference C denotes how the power of the motor at maximum speed decreases at the increasing of the clogging/closing portion of the air intake path of the hair dryer (numerical reference 4 in figure 1), with the hair dryer that is fitted with a front delivery mouth.

The dotted line denoted by the reference D denotes how the power of the motor at maximum speed decreases at the increasing of the clogging/closing portion of the air intake path of the hair dryer (numerical reference 4 in figure 1), with the hair dryer that is not fitted with a front delivery mouth.

The graphs C and D show that, at a clogging/closing of the air intake path of the hair dryer equal to at least 80% of the length, there is a power loss of more than 30% of the rated electric power at maximum speed and the exceeding of the limit for the lighting of the luminous signal.

Different changes can be made to the embodiments described in detail, anyhow remaining within the protection scope of the invention, defined by the following claims.