EP0970633B1 - Hair dryer with simultaneous delivery of cold and warm air - Google Patents

Abstract

The hair dryer contains first and second adjacent air ways (17,19) which simultaneously deliver a parallel hot and cold air flow in the same direction (XX') and sense (18,20). The airways have a common wall which is parallel to the large side of the air flow. The hot air way (17) delivers an air through a channel shorter than that of the cold air flow channel (19). Preferred Features: The difference in length between the two channels is 1 cm.

Description

Electric hair dryers delivering an air flow are essential accessories in hairdressing salons: they not only allow professionals to dry outright wet hair after shampooing, but also, stylists, to highlight forms the hairstyle and create the curls and waves that they desire.

For this last operation, relatively air hot is absolutely necessary: the hair can only be styled from of a certain temperature. It should be kept in shape until it cools, which delays the completion of the hairstyle.

If a cold air flow was immediately available, it would be possible to cool the wicks quickly and thus save time and as.

Conventional hair dryers can deliver air cold by cutting the electrical supply to the heating resistor, but, at because of the thermal inertia of the assembly, the switching between hot air and cold air is not instant.

This disadvantage of conventional hair dryers, only delivering hot air through a nozzle, had been recognized by Robert Bartolac, who proposed a modification of these, disclosed in the patent US-A-4297564 published October 27, 1981.

The modification consists in adding to the back of the device a second nozzle delivering cold air in the same direction, but in an opposite direction. Cold air is taken directly from the fan internal. A rotary seal allows to activate or close this second nozzle. When said second nozzle is active, a simple movement of the hand is enough to apply either hot air or cold air by turning the hair dryer held by the handle.

If the problem of cooling the wicks of hair is thus elegantly resolved, but not really satisfactory insofar as such cooling is not immediate, the downside of the effects of intense heat on the hairline, as well as on the person who is styled himself, remains.

This other disadvantage of common hair dryers, whose electrical power continues to increase, and, concomitantly, risks of damage and burns in their use, had been clearly identified by Andrew Hlavac. The new type of hair dryer described in the patent American US-A-3943329, published on behalf of this inventor on March 9, 1976, has a safety nozzle designed to eliminate these dangers. This nozzle, from pyramidal or frusto-conical shape, extends the hot air outlet. Its plus size large reserve a space through which cold air is sucked in by venturi effect. The the projected air flow temperature is lower and the person's hair styled are not likely to come into contact with a very hot item of the device.

However, if job security is improved by when using this type of nozzle, the efficiency of this new hair dryer is probably less.

Swiss patent CH-A-669319 from the company Spemot, published March 15, 1989, reveals another type of hair dryer delivering hot and cold air simultaneously. A fraction of the air produced by the fan is, before the air is heated, deflected by the resistance to a secondary outlet by means of a valve controlled by a trigger. This arrangement makes it possible to make the gestures of the hairdresser even simpler to achieve the results obtained using the apparatus described by US-A-4297564. However, in this other technique, the direction of the cold air flow projected by the secondary outlet is different from that of the main hot air flow.

Some common operations, such as "brushing" or the setting in volume of the hair, cannot thus profit from this provision.

Document DE-U-9100860 recalls that hair dryers blowing either hot or cold air, depending on whether the resistance heater is in service or not, are known from the state of the art. He recalls also that the hold of the hair after styling with hot air is all the more better than cold air cooling is fast. The hair dryer described in this document therefore aims to minimize the time between the application of hot air and the application of cold air by a hair dryer.

For this purpose, the heating part and the outlet nozzle of the device conforming to DE-U-9100860 are shared in two by a partition middle, two separately switchable heating elements being mounted each side of said partition.

Inside the case, two hot / cold air ducts are thus juxtaposed. If only one heating element is in use, this apparatus therefore delivers a flow of hot air and a flow of cold air which are collateral; the hot air flow is located either to the right or to the left of the handle plane, depending on that either resistor is switched. However, according to this construction, the cold air flow can never be located below the hot air flow, first to avoid burning the scalp, when the device is held normally in hand, and then and above all to immediately cool the hair that comes to be heated, because, on the one hand, the two flows of hot air and cold air are collateral and, on the other hand, it is impossible that the nozzle of the device can rotate around its axis.

Document FR-A-1387334 also describes a hair dryer having two hot air and cold air ducts, these two ducts being concentric and surrounding a unique heating element. So the flows produced by this device are two flows concentric cylindrical - the hot flow being in the center - not in the form of blades flat, and therefore these flows have large inadequate sections.

It therefore appears from the state of the art as described in the documents cited above as hair dryers delivering both hot and cold air are known, but that there is no day no hair dryer of this type having such characteristics as it is advantageously usable for all work in the hair salon, while guaranteeing the total absence of inconvenience for the person wearing the hair.

GENERAL DESCRIPTION OF THE INVENTION

The present invention relates to an air hair dryer simultaneous hot and cold air.

Conventionally, this hair dryer has a housing of the general shape of a surface of revolution about an axis longitudinal, having a front part and a rear part. A motor electric is mounted inside the rear part of the case and drives a fan. This fan produces an air flow from back to front, drawn in by a air inlet provided through the wall of the housing. A first conduit channels a first part of the air flow, while a second duct surrounding said first conduit channels the second part of the flow.

Conventionally, an electrical resistance heats the first part of the air flow. A handle, integral with the housing, is provided with engine speed and power control buttons electric consumed by the resistor from an electrical energy source exterior. A first nozzle, provided in the extension of the first conduit, delivers hot air and a second nozzle provided as an extension of the second duct delivers cold air.

The subject of the invention is precisely a hair dryer. of this type, known in particular from document FR-A-1,387,334, hair dryer the essential feature is that the first and second nozzles deliver simultaneously, respectively, a flat blade of hot air and a flat blade of cold air parallel to the same direction and in the same direction.

An additional feature of the hair dryer according to the invention is that the first and second nozzles are adjacent, their wall common being parallel to the long sides of the hot and cold air knives delivered and being located substantially in a radial plane of the housing.

It is remarkable to provide additionally that the first nozzle delivering the hot air blade is shorter than the second nozzle delivering the cold air knife and that the plane of the outlet opening of said second nozzle be inclined with respect to a plane perpendicular to the common direction of air flow, the angle of this inclination preferably being between 30 ° and 45 °.

According to the invention, the first and second nozzles can advantageously be constituted by a single nozzle with double conduit and double orifice. This single nozzle is then fitted onto the front part of the housing, while being held fixed in translation longitudinally and free in rotation around said front part of the housing.

In this last construction variant, the double duct advantageously has an inlet, corresponding to the duct of shortest outlet, circular section. The first conduit is then a tube whose the front part also has a circular section. The front part of this tube is engaged in this entry while remaining free to rotate. Of preferably, the rear part of the tube is, for its part, maintained substantially at center of the base of the front part of the case by at least three ribs longitudinal.

Very advantageously, the cross section of each of the outlet ports of the single nozzle is rectangular, preferably approximately ten times longer than wide.

Another feature of the hair dryer according to the invention is that the single nozzle is preferably kept fixed in translation longitudinally by means of at least two clips cooperating with a groove annular cut in the front part of the case.

According to another interesting feature, the section of the first duct channeling the part of the air flow to be heated can advantageously be substantially equal, or even slightly greater, than that of second duct channeling the other part of the air flow whose temperature is not changed.

The simultaneous hot air and cold air hair dryer according to the invention is very advantageously used for the implementation of a drying process consisting in spraying a flow onto the object or material to be dried of laminar plane air having a transverse temperature gradient, the part la colder the flow being kept closer to the surface of the object or the material by rotating the single nozzle of the device.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 shows, right view, the structure general of the simultaneous hot air and cold air hair dryer in accordance with the invention.

Figure 2 is a section along a median plane A-A showing the internal structure of the hot air and cold air hair dryer simultaneous according to the invention.

Figures 3a and 3b are respectively a view of side and a rear view of the single nozzle with double orifice according to a advantageous feature of the hot air and cold air hair dryer simultaneous according to the invention.

DESCRIPTION OF A PREFERRED FORM OF THE INVENTION

The references to Figures 1, 2, 3a and 3b will serve to explain the different features of the invention.

The general shape of the housing (1) of the hair dryer is that of a surface of revolution around a longitudinal axis (XX '). The part front (2) of this housing has the general shape of a small aperture truncated cone, with an average diameter greater than the current dimension of a device of the same category. This front part (2) is attached to a rear part (3) of which the general, traditional appearance is that of a cylinder which would be swollen in its middle part, or a small barrel. In the embodiment of the invention, this part is, still in the traditional way, itself made up of two half-shells fitting one inside the other.

An electric motor (4) is mounted inside the rear part (3) of the housing (1). It is a motor running on current 220-240 V AC and having a power of one hundred watts. This engine (4) drives a fan (5) of centrifugal type (both shown in dotted on Figure 1), which produces an air flow (6) from back to front at inside the housing (1).

The air is sucked in through an air inlet (7) provided at the through the rear wall of the housing (1). This air inlet, fitted with a grid, is also an insert on the rear part (3).

A first conduit (8), having the general shape of a frustoconical opening substantially equal to that forming the front part (2), channels a first part (9) of the air flow (6) produced by the fan (5). The space left free by this first tubular conduit (8), in the front part (2) hair dryer, constitutes a second conduit (10) channeling the second part (11) of the air flow (6).

As shown in Figure 2, resistance electric (12), wound on crosses, is inside the first conduit (8). With an electrical power of between 1,500 W and 1,700 W, it heats the part (9) of the air flow circulating in the first duct (8).

A handle (13) attached to the rear part (3) of the hair dryer allows easy use of it. This handle is presented in the form of two half-shells joined by screws. Traditionally, these two half-shells are in fact advantageously the extensions of the two half-shells constituting the rear part (3) of the device.

The handle (13) carries two buttons (14, 15) of ordered. One (14) sets the speed of the electric motor (4): as required, the fan (5) can be stopped or maintained at a medium speed or maximum. The other button (15) switches the electrical power consumed by the heating resistor (12) between a zero, average value and maximum.

The handle (13) is provided with a grommet intended for hold the AC power cord (16).

A first nozzle (17) with a narrow outlet orifice and elongated is in the extension of the first conduit (8) containing the heating resistor (12), and it consequently delivers a blade of hot air (18). A second nozzle (19), the outlet opening of which is also narrow and elongated, collects the cold air flow (11) circulating between the internal wall of the front part (2) of the device and the duct (8) channeling the hot air, to eject it in the form a blade of cold air (20) in the same direction (XX ') and in the same direction as the hot air blade (18).

Preferably, the section of the first conduit (8) is substantially equal to or even slightly higher than that of the second conduit (10) so that the flow of hot air produced by the device according to the invention is equal to, or according to, slightly higher than the cold air flow.

As shown in Figures 3a and 3b, the nozzles (17, 19) have a complex shape. The set looks like two tips flat, classic, which would have been nested laterally one inside the other, a lower side part of the nozzle intended to blow cold air having been deleted. A lateral part of the nozzle blowing hot air then constitutes the common wall (21) of the two nozzles (17, 19). The two nozzles are arranged such that this common wall (21) corresponds to a radial plane (BB) of the housing (1).

As indicated by the section along the median plane (AA) shown in Figure 2, the first nozzle (17) delivering the hot air blade is shorter than the second nozzle (19) delivering the cold air knife, the difference length (E) being substantially 1 cm in this preferred embodiment.

In addition, the plane (CC) of the outlet orifice (22) of the second nozzle (19) has an angle of inclination (α) relative to a plane perpendicular to the longitudinal axis thereof. This angle of inclination (α) is about 35 ° for this particular embodiment of the nozzle (19).

The length difference (E) between the two nozzles (17, 19) and the bevel size of the nozzle (19) delivering the cold air blade depends on the use which will be made of the hair dryer, as will be explained later. However, the angle of inclination (α) is preferably between 30 ° and 45 °.

The front and rear views of the nozzles (17, 19), shown in Figures 3a and 3b, show that they actually form a part in one piece constituting a single nozzle (23) with double duct (24, 25) and double orifice (22, 26).

As with conventional flat tips, the cross section of each of the outlet openings (22, 26) of the single nozzle (23) is rectangular, and about ten times longer than wide. Cold air flows (20) and hot air (18) supplied by the single nozzle (23) are therefore both laminar.

This single nozzle (23) can be manually inserted on the front part (2) of the hair dryer. It is held there fixed longitudinally, while being free to rotate. By exerting an effort sufficient, it can however be removed manually to be replaced by when needed.

The inlet (27) of the corresponding double conduit (24, 25) the shortest outlet duct (25) is of circular section. Front end (28) of the conical duct (8) containing the resistor (12) is also of section circular, slightly smaller in diameter than the inlet (27), and is engaged in this entry (27) while remaining free to rotate in the two sense, retrograde and direct.

The section (AA) in Figure 2 shows that the part rear (29) of the tubular conduit (8) is held substantially in the center of the base (2 ') of the front part (2) of the housing (1) by longitudinal ribs (30). These ribs have the appropriate width at the back and they narrow towards the front, until it disappears: the front part (28) of the tubular conduit (8) can thus freely debate within the entire section of the front part (2) of the housing (1).

This particular arrangement allows the orifices (22, 26) to be oriented, as required, by rotation of the single nozzle (23) around the front part (2) of the hair dryer, while continuing to be supplied with air cold and hot air, respectively. During this rotation of the nozzle (23), and whatever the direction of said rotation, the front part (28) of the duct (8) remains engaged in the circular inlet (27) of the nozzle, so that the conduit (25) opening to the outside through the orifice (26) always blows hot air, and only hot air.

According to the particular embodiment described, the nozzle single (23) is held longitudinally by means of at least two clips (31) cooperating with an annular groove (32) cut in the front part (2), near the end of it. This process is well known in the field of the manufacture of molded plastic articles. He was retained here because he contributes to the ease of use of the device.

The hair dryer according to the invention has numerous advantages, in particular due to the shape of the outlet orifices of the nozzles (17, 19) constituting the single nozzle (23), relative positions of these orifices outlet and differences in length (E) of the nozzles (17, 19).

It allows the operator to immediately check which is the outlet (26) of hot air (18) and which is the outlet (22) of cold air (20).

It especially offers the professional the possibility of putting implementing a new hair drying process, consisting of spraying onto the hairline a laminar air flow with a transverse gradient of temperature, the coldest part of the flow being advantageously maintained at closer to the scalp.

To do this, the longest nozzle (19), which blows from cold air (20) is placed close to or even against the head, the shortest nozzle (17), which delivers hot air (18), being on the other hand the farthest from the head. Depending on whether one is styling the left or right part, or the top of the head, or the neck, one orient the single outlet nozzle (23), by rotating it around the part front (2) of the housing (1), in order to respect this arrangement of the nozzles (17, 19).

Thanks to this process, the hair, first shaped and dried by hot air, are immediately cooled after the passage of air hot. Indeed, by tradition, the hair dryer follows the brush which shapes the hair in a movement, controlled by the hairdresser, going from the base of the hair towards the tip of it; due to this movement imposed on the hair dryer by the hairdresser, the hot air blade is also moved from the base of the hair to dry and shape towards its tip and the blade of cold air follows immediately the blade of hot air in this same movement; so the setting the shape given to the hair by hot air is immediately fixed by cold air.

Such hair treatment with air mixture hot / cold air leads to better swelling of the hair, as well as better holding the "brushing" and setting the volume of the hairstyle.

Finally, the use of cold air as close as possible to the leather hair prevents the effects of heat on the person who is styled.

The construction according to the present invention constitutes so a different overall solution to the problem of fast air switching hot / cold air (parallel laminar flow) and the safety problem (avoid spray hot air on the scalp).

In this regard, the construction according to the invention, by its structure and the results to which it leads, is clearly distinguished from that described in document DE-U-9100860. Indeed, thanks to the invention, the fact of provide that the cold air duct surrounds the hot air duct, at a level single heating element placed substantially axially, allows to rotate the single nozzle (23) and adopt the best position of the outlet orifices (22, 26) for styling. Next, the outlet nozzles (17, 19) are adjacent, their walls common (21) being parallel to the long sides of the cold air and hot air blades delivered, whereas according to DE-U-9100860, the adjacent outlet nozzles have a common wall which is perpendicular to the long sides of the two air knives issued. In this latter construction, the flows of hot air and cold air do not therefore not automatically follow in the movement controlled by the hairdresser, going from the base to the tip of the hair.

As for the hair dryer in accordance with document FR-A-1.387.334, it is unsuitable for carrying out drying and shape of the hair for which flows of hot air and cold air are distributed in laminar and parallel form, the blade of cold air also being always kept as close as possible to the scalp or the surface of the object to be cooled if this object is other than a hair.

Claims (11)

1. Hair dryer using hot and cold air simultaneously, comprising a casing (1) generally in the shape of a surface of revolution about a longitudinal axis (XX') having a front portion (2) and a rear portion (3), an electric motor (4) mounted inside said rear portion (3) and driving a fan (5) which produces an air flow (6) from back to front sucked in through an air inlet (7) provided through the wall of said casing (1), a first conduit (8) channelling a first part (9) of the air flow (6), a second conduit (10) surrounding said first conduit (8) and channelling the second part (11) of said air flow (6), an electrical resistor (12) heating said first part (9) of the air flow (6), a handle (13) provided with buttons or knobs (14, 15) for controlling the speed (14) of said motor (4) and for regulating the electrical power (15) consumed by said resistor (12) from an external source of electrical energy (16), a first nozzle (17) located on an extension of the first conduit (8) supplying hot air (18), and a second nozzle (19) located on an extension of the second conduit (10) supplying cold air (20), characterised in that the first and second nozzles (17, 19) simultaneously supply a flat laminar flow of hot air and a flat laminar flow of cold air, respectively, parallel to the same direction (XX') and travelling in the same direction (18, 20).
2. Hair dryer using hot and cold air simultaneously according to claim 1, characterised in that the first and second nozzles (17, 19) are adjacent, their common wall (21) being parallel to the long sides of the laminar flows of hot and cold air delivered and being located substantially in a radial plane (BB) of the casing (1).
3. Hair dryer using hot and cold air simultaneously according to either of claims 1 and 2, characterised in that the first nozzle (17) supplying the laminar flow of hot air is shorter than the second nozzle (19) supplying the laminar flow of cold air, the difference in length (E) preferably being 1 cm.
4. Hair dryer using hot and cold air simultaneously according to any one of claims 1 to 3, characterised in that the plane (CC) of the outlet orifice (22) of the second nozzle (19) is inclined at an angle (α) relative to a plane perpendicular to the direction (XX'), said angle of inclination (α) preferably being between 30° and 45°.
5. Hair dryer using hot and cold air simultaneously according to any one of claims 1 to 4, characterised in that the first and second nozzles (17, 19) consist of a single nozzle (23) with a double conduit (24, 25) and a double orifice (22, 26) fitted onto the front portion (2) of the casing (1) while being held longitudinally fixed in translation and freely rotatable about said front portion (2).
6. Hair dryer using hot and cold air simultaneously according to claim 5, characterised in that the double conduit (24, 25) has an inlet (27), corresponding to the shortest outlet conduit (25), which is circular in section, and in that the front portion (28) of the first conduit (8) is circular in section, said front portion (28) of the conduit (8) engaging in the inlet (27) while remaining freely rotatable.
7. Hair dryer using hot and cold air simultaneously according to claim 6, characterised in that the rear portion (29) of the conduit (8) is held substantially in the centre of the base (2') of the front portion (2) of the casing (1) by at least three longitudinal ribs (30).
8. Hair dryer using hot and cold air simultaneously according to any one of claims 5 to 7, characterised in that the straight section of each of the outlet orifices (22, 26) of the single nozzle (23) is rectangular and preferably about ten times longer than it is wide.
9. Hair dryer using hot and cold air simultaneously according to any one of claims 5 to 8, characterised in that the single nozzle (23) is held longitudinally fixed in translation by means of at least two clips (31) cooperating with an annular groove (32) cut into the front portion (2) of the casing (1).
10. Hair dryer using hot and cold air simultaneously according to any one of claims 1 to 9, characterised in that the section of the first conduit (8) channelling the part (9) of the air flow which is to be heated is substantially equal to, or slightly greater than, that of the second conduit (10) channelling the other part (11) of the air flow the temperature of which is not modified.
11. Drying process using the hair dryer with hot and cold air simultaneously according to any one of the preceding claims 1 to 10, characterised in that a flat laminar air flow having a transverse temperature gradient is directed at the object or material which is to be dried, the coldest part of the air flow being kept closest to the surface of said object or material which is to be dried by rotationally manoeuvring a single nozzle (23).

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