# Patent

## Title
Device for spraying a cosmetic composition while blowing hot or cold air

## Abstract

A device for spraying a cosmetic or dermatological composition may comprise an ultrasound or electrostatic spray head, an airflow generator for entraining a spray of composition particles atomized by the spray head and a conditioning device, the conditioning device arranged to modify the temperature of the outgoing stream of air.

## Background
This application claims the benefits of priority of French Application No. 08 50926 filed on Feb. 13, 2008 and U.S. Provisional Application No. 61/033,321 filed on Mar. 3, 2008, which is incorporated by reference herein.
This application is related to U.S. patent application Ser. No. 12/370,096, entitled “A Spray Head Including A Sonotrode With A Composition Feed Channel Passing Therethrough” and U.S. patent application Ser. No. 12/370,136, entitled “A Spray Head Including A Sonotrode” each filed concurrently herewith. The contents of these related applications are hereby explicitly incorporated by reference.


FIELD OF THE PRESENT DISCLOSURE
The present disclosure relates to devices for spraying a composition, in particular for spraying a composition on keratinous materials such as, for example, human skin or hair.
BACKGROUND OF THE PRESENT DISCLOSURE
U.S. Pat. No. 4,523,080 discloses a hair dryer arranged to receive an aerosol can so that the spray generated thereby is drawn through the fan. A heater device is located downstream from the fan. The particles of the composition can come into contact with the heater device, and that can denature the composition and reduce the effectiveness of the heater device.
FR 2 747 542 discloses a hair dryer arranged to spray a mist of fine water droplets in order to humidify the hair.
FR 1 471 557 describes a hairdrying comb comprising an injector for expelling composition into a cylindrical portion provided with combing teeth.
FR 2 780 664 discloses a fumigation device, i.e., a device in which the composition is vaporized completely, which is different from spraying on a region to be treated.
JP 10-085314 also describes a device for evaporating a fragrance.
DE 32 02 597 describes a cosmetic fluid spray device made up of two portions, one of which includes a heater device that does not operate when the two portions are coupled together.
EP 1 435 209 describes an automatic, system for spraying a cosmetic or medical composition onto all or part of the human body in a chamber provided for that purpose.
U.S. Pat. No. 3,970,250 describes a cosmetic or medical composition spray device including an electronic excitation system under a spray head.
OBJECT AND BRIEF SUMMARY OF THE PRESENT DISCLOSURE
Therefore, it is desirable to overcome one or more of the disadvantages of the prior art with an improved spray device.
Exemplary embodiments of the present disclosure provide a device for spraying a cosmetic or dermatological composition, the device comprising.

    
    
        an ultrasound or electrostatic spray head;
        an airflow generator, e.g., a fan and/or compressed air, for creating a stream of air for entraining a spray of composition particles atomized by the spray head; and
        a conditioning device for modifying (e.g., heating and/or cooling) the temperature of the outgoing stream of air, in particular for heating the air.
    
    


Such a device may serve to accelerate drying of the composition and may result in a more comfortable application.
In particular, the outgoing composition may not be completely vaporized. The spray device can enable the outgoing composition to be sprayed in the form of fine droplets. In particular, the outgoing composition may not be completely gasified. The outgoing composition may be also be in the form of droplets at a predefined distance from the spray device, e.g., 10 cm.
The device may be arranged to raise the temperature of the outgoing stream of air to greater than 30° C., and in some embodiments to greater than 35° C. By way of example, the temperature of the outgoing stream of air may be less than or equal to 40° C.
The above-specified outlet temperature values are provided based on an air inlet temperature of 25° C.
The conditioning device may advantageously be located upstream from said airflow generator, in particular a fan, and/or the spray head.
The conditioning device may include a resistance heater.
The resistance heater may be coiled.
The resistance heater may comprise a resistance wire, for example Nichrome wire.
In some embodiments, the spray device may include a sonotrode for transmitting ultrasound vibration from a transducer to an ejection surface for ejecting particles of composition.
The sonotrode may include a channel for feeding composition to the ejection surface. In a variant, the composition may be fed in some other way, e.g. by means of a capillary system.
The sonotrode may include an end collar defining a surface for ejecting particles of composition, the collar being suitable for bending under the effect of the sonotrode vibrating. This may assist in improving spraying efficiency.
While oscillating, the collar may be deformed by changing the shape of the ejection surface, which may, for example, pass from being a plane at rest to being concave or convex. The amplitude of bending towards the front or towards the rear may be greater than or equal to 5 micrometers (μm) from the at-rest position, e.g., lying in the range of 5 μm to 25 μm, relative to the at-rest position, with a total amplitude of approximately 10 μm to 50 μm.
The minimum thickness of the end collar in the region where particles of composition are ejected may, for example, lie in the ranges 0.4 mm to 0.6 mm, 0.45 mm to 0.55 mm, and may be equal to 0.5 mm in some embodiments.
Droplets of composition may be ejected over the substantially the entire circumference of the end collar. This may improve uniformity of the spray.
The sonotrode may include a portion of decreasing diameter that is extended by a cylindrical portion (or “ejector”) that is connected to the end collar,

    
    
        the ratio of the transducer diameter divided by the diameter of the cylindrical portion being less than or equal to 4.5, and in some embodiments equal to 4 or 3.7, and possibly greater than or equal to 3. In some embodiments this range may lie in the range 3.5 to 3.7; and/or
        the ratio of the collar diameter divided by the diameter of the cylindrical portion lying in the range 7/6 to 13/4; and/or
        the ratio of the diameter of the collar divided by the thickness of the collar lying in the range 70/6, e.g., 12, to 130/4, e.g., 32.
    
    


These geometrical characteristics may lead to results that are particularly desirable.
The collar may have a transverse dimension that is less than or equal to λ/4, where λ is the wavelength of the of the ultrasound wave in the material of the sonotrode.
The length of the sonotrode between the face of the sonotrode in contact with a transducer for setting the sonotrode into vibration and the ejection surface may be less than or equal to λ, e.g., of the order of λ/2.
The composition feed channel may present a narrow portion.
The narrow portion may serve to brake the flow of composition and improve the performance of spraying. The narrow portion may, in particular, enable a relatively uniform spray to be obtained.
The presence of the narrow portion may result in easier fabrication of the remainder of the channel, which may be of relatively large section. Such a design may assist in limiting head losses.
The narrow portion may provide a certain amount of capillary retention when the device is not in use, thereby enabling exchange with air to be reduced. The use of a shutter for the feed channel can thus be avoided.
The present disclosure may be applied to numerous cosmetic or dermatological compositions, for example, a foundation, a self-tanning agent, a lotion for the body or the face, a composition containing a hair agent, and/or a sunscreen composition, among others.
The term “hair agent” is used to mean any ingredient for a composition that serves to provide cohesion to a piece of hair by depositing a material that limits relative movement between individual hairs, for example any polymer.
It is possible to use any hair agent and it is also possible to use mixtures containing a plurality of such agents.
Conventionally, a distinction is drawn between hair agents that are cationic, anionic, amphoteric, or non-ionic.
The hair agent may be selected from silicone or non-silicone polyurethanes, linear sulfonic polyesters, acrylic copolymers with branched blocks, and octalacrylamide-acrylate-butylaminoethylmethacrylate copolymers among others.
Thus, exemplary hair agents may include, for example, Amphomer from National Starch, Luviset Si Pur from BASF, Fixate T100 from Noveon, Mexomere PW from Chimex, and AS 55S from Eastman.
The sprayed composition may have viscosity greater than or equal to 0.1 millipascal seconds (mPa·s), greater than or equal to 1 mPa·s, a range of about 10 mPa·s to 500 mPa·s, and for example, in the ranges 20 mPa·s to 150 mPa·s or 50 mPa·s to 100 mPa·s.
With a composition such as an oil, for example, viscosity may be measured at 25° C. with a Haake RS 600 imposed stress rheometer, as sold by the supplier Thermo Rhéo, fitted with a moving body of cone/plane shape of the 60/1° type (60 mm for an angle of 1°). Rising stress is imposed going from 0 to 1000 Pa over 100 seconds (s). Then the rheogram representing variation in viscosity as a function of shear rate may be plotted. The rheogram presents a plateau at low values for shear rate (known as the Newtonian plateau), said plateau corresponding to a stable value for viscosity and constituting the viscosity of the composition as determined in this way.
With a composition such as a foundation, for example, viscosity can be measured at 25° C. with a Rhéomat 180 viscosity meter fitted with the MK-R2 moving body and the MB-R2 measuring flask having a volume of 60 milliliters (mL) at a speed of rotation of 200 revolutions per minute (rpm), the measurement being performed after 10 minutes of rotation (after which time the viscosity is observed to stabilize, as is the speed of rotation of the moving body).
The sonotrode is coupled to a transducer that enables electrical energy to be transformed into ultrasound vibration. The resonant frequency of the sonotrode may be similar to that of the transducer. Coupling may be achieved, for example, by adhesive bonding or by screw fastening, or any other suitable method.
The particles of composition may be entrained towards the region for treatment by a stream of air, which may be produced, for example, by at least one fan. By way of example, the flow rate of the air may lie in the range 4 cubic meters per hour (m3/h) to 7 m3/h, and in some embodiments in the range 5.5 m3/h to 6.5 m3/h.
In some embodiments, the narrow portion may open out to the ejection surface. The narrow portion may present a cross-section that is constant over a distance of at least 1 mm and less than or equal to 10 mm. A length of the narrow portion may, for example, be less than equal to 7 mm, in the range 1 mm to 5 mm, e.g., 2.5 mm. The narrow portion may present a cross-section that is constant from the end where it opens out into the ejection surface to its opposite end.
The narrow portion presents a cross-section that is circular, which may lead to manufacture.
The channel may present a cross-section that is circular over its entire length.
The channel may be rectilinear, having substantially the same longitudinal axis as the sonotrode. The narrow portion may present a small cross-section that is less than or equal to 0.8 square millimeters (mm2). In particular, the narrow portion may present a diameter less than or equal to 1 mm, e.g., lying in the range 0.4 mm to 0.8 mm, and is may be close to 0.6 mm.
In some embodiments, the channel may present a maximum cross-sectional area that is greater than or equal to 0.8 mm2.
Outside the narrow portion, the channel may present a diameter lying in the range 1 mm to 2 mm, e.g., being close to 1.5 mm, or greater in some embodiments, in particular, when the transducer is fastened to the sonotrode by bolting.
The ratio of the length of the narrow portion divided by the total length of the sonotrode channel may lie in the range 0.04 to 0.4.
The ratio of the greatest cross-sectional area of the channel divided by the narrowest cross-sectional area of the channel may lie in the range 1 to 25, in particular in the range 4 to 10, e.g., in the range 6 to 6.5.
In some embodiments, the channel may feed the ejection surface via a single outlet orifice, which may be situated in the center of the ejection surface.
The sonotrode may be made as a single piece with a connection endpiece for connection to a tube for feeding the channel with a composition. The feed tube may be, for example, a flexible hose, thus enabling the tube to be used within a peristaltic pump. The channel may also be connected to the feed duct in some other way, for example, by means of an endpiece inserted in the sonotrode.
The endpiece may pass through the transducer, which transducer may be annular in shape.
By way of example, the outside diameter of the end collar may lie in the ranges 7 mm to 13 mm, 8 mm to 12 mm, 9 mm to 11 mm, and may be close to 10 mm. Embodiments with a diameter of 10 mm for the end collar and a minimum thickness of 0.5 mm for the collar, at a frequency of 100 kHz±10% may be desirable.
The peripheral annular region of the collar where the thickness of the collar is relatively small, and in particular less than or equal to 0.6 mm, may itself present a width, measured radially, that is greater than or equal to 0.2 mm, e.g., lying in the range 0.2 mm to 2 mm.
The end collar may present an annular area having a thickness of 0.5 mm that extends over a radially-measured width of at least 0.5 mm.
The sonotrode may present a portion of outside cross-section that decreases towards the ejection surface, and in particular a portion that is frustoconical. The angle at the apex of this frustoconical portion may lie in the range 10° to 45°, and may, for example, be 30°.
The sonotrode may present a portion that is circularly cylindrical, as mentioned above. The portion of tapering for an outside section may join said circularly-cylindrical portion, the circularly-cylindrical portion being intermediate between the portion of tapering section, in particular of the frustoconical section, and the end collar.
The outside diameter of the circularly-cylindrical portion lies for example in the range 4 mm to 7 mm, and in particular, may be close to 5.5 mm.
The width of the circularly-cylindrical portion may lie, for example, in the range 3 mm to 5 mm.
The lengths of the various portions of the sonotrode may be selected as a function of the nominal frequency at which the sonotrode is designed to resonate. Further the ejection surface may be situated level with a vibration antinode. The distance between the ejection face and the transducer, and also the diameter of the end collar may depend on the wavelength λ, which equals c/f where c is the speed of sound in the material at the utilization temperature, and f is the frequency.
The sonotrode may be machined, and may comprise a metal, for example, aluminum or aluminum alloy, titanium or titanium alloy, and/or stainless steel, e.g., 316 type stainless steel.
The excitation frequency of the transducer may lie, for example, in the range 30 kHz to 200 kHz. By way of example, the excitation frequency may be of the order of 100 kHz±10%.
The mean size of the particles of the spray may depend on the frequency f and on the rheological characteristics of the fluid that is to be nebulized among other things. In an exemplary embodiment of the present disclosure, the mean size of the particles may lie in the range 20 μm to 25 μm, in particular at a frequency of 100 kHz. The content of fine particles of size smaller than 10 μm may be less than 10% by volume.
Other exemplary embodiments of the present disclosure also provide a device for spraying a cosmetic or dermatological composition, the device comprising:

    
    
        a spray head;
        an airflow generator for entraining a spray of composition particles atomized by the head; and
        a conditioning device for raising or lowering the temperature of the outgoing stream of air, the spray head being placed downstream from the device.
    
    


This avoids any risk of the conditioning device becoming clogged with composition.
Other exemplary embodiments of the present disclosure also provide a device for spraying a cosmetic or dermatological composition, the device comprising:

    
    
        a spray head;
        an airflow generator for entraining a spray of composition particles atomized by the head; and
        a conditioning device for modifying the temperature of the outgoing stream of air;
        the spray head, the airflow generator, and the conditioning device being in alignment.
    
    


This simplifies construction of the device.
The spray device may, in general, include a container containing the composition for spraying. The composition may be a care product or makeup, in particular a foundation or a composition including a hair agent, a self-tanning agent, or a sunscreen, as mentioned above.
The container may be in the form of a removable cartridge.
The composition may be contained in a flexible pouch.
The device may include a box having a housing for receiving said cartridge, in particular a housing in its top portion.
The stream of air directed towards the keratinous material may be heated or cooled, depending on, for example, a fluid to be sprayed, ambient temperature, etc.
In some exemplary embodiments of the present disclosure, spraying may be triggered by the user acting on a control member, such as a pushbutton, for example.
Once a spray cycle has been triggered, a spray sequence having the following steps may take place:

    
    
        i) switching on a fan to create a stream of air for entraining particles of composition;
        ii) after a predefined delay, setting the sonotrode into vibration by means of a transducer; and
        iii) after another delay, switching on a pump feeding the sonotrode with composition.
    
    


At the end of the spray cycle, the device may be stopped by successively stopping the pump, stopping the transducer, and stopping the fan.
The conditioning device may be switched on simultaneously with the fan or at a different time.
Other exemplary embodiments of the present disclosure also provide a cosmetic treatment method, e.g. a method of making up the skin, or a method of treating the hair, the method including the steps consisting in:

    
    
        spraying a cosmetic composition on the human keratinous materials concerned by using a device as defined above.
    
    


Where appropriate, in order to accelerate drying of the composition, the device may be used, after deposition has been performed, to blow optionally hot air while not spraying any composition.



BRIEF DESCRIPTION OF THE DRAWINGS
The present disclosure can be better understood on reading the following detailed description of exemplary non-limiting embodiments thereof, and on examining the accompanying drawings in which:
FIG. 1 is a diagrammatic elevation view showing an exemplary spray device made in accordance with some embodiments of the present disclosure;
FIG. 2 shows the exemplary device of FIG. 1 with an exemplary cartridge of composition in place, ready for spraying;
FIG. 3 shows the device of FIG. 1 with an exemplary access hatch to the cartridge-receiver housing open, ready for the cartridge to be put into place on the housing;
FIG. 4 is a diagrammatic and fragmentary exploded perspective view showing the device of FIGS. 1 to 3.
FIG. 5 is a diagrammatic and fragmentary perspective view of an exemplary sprayer assembly according to some embodiments of the present disclosure;
FIG. 6 is a diagrammatic and fragmentary longitudinal section view of the exemplary sprayer assembly of FIG. 5;
FIG. 7 shows an exemplary transducer support of the spray in isolation;
FIG. 8 shows an exemplary sonotrode of the sprayer in perspective and isolation;
FIG. 9 is an elevation view of an exemplary sonotrode;
FIG. 10 is a longitudinal section of the exemplary sonotrode on X-X of FIG. 9;
FIG. 11 is a perspective view of another exemplary embodiment of the sonotrode;
FIG. 12 is a diagrammatic and fragmentary longitudinal section view of a spray head including the exemplary sonotrode of FIG. 11; and
FIG. 13 is a diagrammatic perspective view of an exemplary resistance heater device.



MORE DETAILED DESCRIPTION
Spray device 1 shown in FIGS. 1 to 3 includes a box 2 suitable for handling by the user to spray a composition onto the skin or onto other human keratinous materials such as the lips and/or the hair for examples.
Box 2 in the example shown has a pushbutton 3 enabling the user to trigger spraying by pressing of otherwise actuating pushbutton 3. In a variant, pushbutton 3 could be situated elsewhere, and it could be replaced by a trigger or a touch-sensitive switch, among other things for example.
At the front, and as can be seen in FIG. 2 in particular, the device includes an ejection surface 4 for ejecting particles of the composition. In some embodiments, this surface may be directed towards a region that is to be treated so as to enable the particles of composition to be deposited on said region.
In the example described, box 2 includes a protective cover 12 suitable for folding down over the ejection surface 4 when not in use. By way of example, cover 12 is hinged to the body of box 2 to be movable between a lowered position in which it covers ejection surface 4 and a raised position. In a variant embodiment, box 2 may not have a protective cover or cover 12 is mounted on box 2 in some other way.
When in the down position cover 12 may extend so as to continue to the outside surface of box 2.
Box 2 may receive a cartridge 15 containing the substance for spraying, cartridge 15 being inserted in a housing 17 in box 2. Cartridge 15 may be removable, fixed, or of suitable configuration.
As can be seen in FIG. 3, while not in use, housing 17 may be shut by a shutter flap 19.
In the example shown, housing 17 opens in an upward direction.
Shutter flap 19 may be mounted to slide on box 2. In some alternative embodiments, housing 17 may be positioned otherwise in box 2.
By way of example, the composition contained in cartridge 15 may be, for example: a foundation; a self-tanning agent; a lotion for the body or the face, and/or a composition containing a hair agent.
By way of example, the capacity of cartridge 15 may lie in the ranges 1 mL to 100 mL, 5 mL to 20 mL, and in particular may be 10 mL.
In some embodiments, device 1 may receive a plurality of cartridges 15 containing different compositions or a cartridge 15 containing a plurality of compositions, with means for selecting which composition is to be sprayed In some embodiments means for adjusting the proportion of one composition relative to another in a sprayed mixture may be included. Where desired, a single cartridge 15 may contain a plurality of compositions together with selector means for selecting which composition is to be sprayed and/or for adjusting the proportions of the various compositions in the sprayed mixture.
In the example described, box 2 may include a general on/off switch 22 and an indicator light 23 to show when it is in operation. On its sides, box 2 may include air inlets 30.
FIG. 4 shows that the body of box 2 may be formed by assembling together two half-shells 2a and 2b. By way of example, half-shells 2a and 2b may be mounted together as a tight-fit, possibly releasably, e.g., being snap-fastened to one another and/or held together by one or more screws. In some embodiments, these half-shells 2a and 2b may be made by molding a thermoplastic material, for example.
Cartridge 15 may comprise two half-shells 15a and 15b that are united around a flexible pouch 35 containing the composition for spraying. By way of example, flexible pouch 35 may be heat-sealed onto a coupling endpiece 38 for engaging a suction endpiece 40 present in the housing 17. Under such circumstances, these endpieces may engage each other so as to define a releasable connection, e.g., of the male/female type.
The use of flexible pouch 35 may enable the composition to be taken without air being drawn into flexible pouch 35. In some embodiments, cartridge 15 may contain a reservoir other than a flexible pouch, e.g., a reservoir with a movable end wall.
In a variant embodiment, cartridge 15 may include a visible indicator showing the extent to which it is has been emptied, e.g., a transparent window made in one of half-shells 15a and/or 15b and/or in flexible pouch 35.
By way of example, half-shells 15a and 15b may be mounted as a tight-fit, possibly separably, e.g., being snap-fastened and/or adhesively bonded one on the other, or fastened in some other way, e.g., being made of a thermoplastic material that may be opaque or transparent.
Placing cartridge 15 in the top portion of the device may make it possible to benefit from a gravity effect for feeding the composition.
Where appropriate, cartridge 15 may be replaced by a cartridge containing a cleaning solution, for the purpose of cleaning the device, in particular the sonotrode and the ejection surface.
The device may be proposed to the user together with one or more cartridges 15 containing one or more compositions for spraying and the above-mentioned cleaner cartridge, for example within a common package.
The cleaner cartridge may optionally be refillable.
The cleaning solution may be selected from one of the solvents of the cosmetic composition in order to be compatible therewith, and for example, it may comprise isododecane, a volatile silicone, and/or alcohol and/or water.
Where appropriate, the device may include a cartridge-recognition system, e.g., using an electromechanical feeler or electrical contacts or a radiofrequency identification (RFID) chip or any other suitable device.
By knowing the content of cartridge 15 that is in position, device 1 may be enabled to adapt its operating parameters automatically to the composition for spraying, e.g., in terms of delivery rate, excitation frequency, air flow rate, and/or air temperature, where appropriate.
Box 2 may house an energy source 43, e.g., one or more optionally-rechargeable batteries, together with a printed circuit 45 carrying the electronic components of device 1. These components serve to generate the voltage utilized for spraying, and to control the various electrical elements. They may also perform auxiliary functions such as, for example: calculating the quantity of composition that remains available for spraying, for example, for the purpose of warning the user when it is necessary to replace cartridge 15.
In order to replace the battery, it may be desirable to open box 2 by separating its half-shells 2a and 2b. In some embodiments, access to the battery compartment may be obtained without opening box 2, via an access hatch to said compartment. Where appropriate, spray device 1 may include an electrical connector enabling a rechargeable battery present in the box to be recharged.
Box 2 also houses a spray assembly (or “ahead”) 50 together with a pump 53, pump 53 being connected firstly to the suction endpiece 40 and secondly to the spray assembly 50 by means of a tube 55, which may comprise a flexible hose.
By way of example, pump 53 may be of the peristaltic type, comprising an electric motor 57 turning one or more wheels that bear against tube 55 so as to urge the composition towards spray assembly 50. The delivery rate of the composition while pump 53 is in operation may lie for example in the range 0.5 grams per minute (g/min) to 2 g/min.
Where desired, the delivery rate may be adjustable by the user over certain preset values.
In some embodiments, other types of pump may be used, for example: gear, diaphragm, and/or piston pumps. It is also possible to use a gravity feed or a resilient shrinkable pouch.
At the rear, the spray assembly 50 includes a airflow generator 60 (e.g., a fan, compressed air, etc.) as can be seen in FIG. 4, airflow generator 60 not being shown in FIG. 5 in order to clarify the drawing.
The spray assembly 50 may also include a nozzle 65 comprising a tubular body that is closed at the rear by a stopper 70 having openings 71 for passing air blown by airflow generator 60.
By way of example, airflow generator 60 may be fastened to the stopper 70, e.g., by one or more screws.
By way of example, the axis of rotation of the fan may coincide with the longitudinal axis of the nozzle 65.
The rate at which airflow generator 60 ejects air into the nozzle 65 may lie in the range 4 m3/h to 7 m3/h, for example.
Airflow generator 60 may draw in air from outside box 2 through inlets 30, among others.
Airflow generator 60 may operate continuously once the user has switched device 1 on by means of the general switch 22, or in some embodiments only when the user triggers spraying by pressing on pushbutton 3. In an example, the operation of airflow generator 60 may continue after the end of spraying for a predefined duration or until the user acts again on device 1, thereby enabling the user to take advantage of the air being blown to accelerate drying of the composition that has been deposited on the region to be treated.
A spraying cycle controlled by acting on pushbutton 3 may comprise initially switching on airflow generator 60, and then after a delay lying in the range of 300 milliseconds (ms) to 800 ms, for example, e.g., about 500 ms, the spray head may be excited. After another delay, e.g., lying in the range 300 ms to 800 ms, and in particular of about 500 ms, pump 53 may be switched on. Spraying may be stopped when pushbutton 3 is released, with the above-described steps following one another in the reverse order or other suitable order/steps.
In some embodiments, a conditioning means may include a device for generating heat. Therefore, device 1 may include heater 200 for heating the air that is blown towards the surface being sprayed. This accelerate drying of the composition and device 1 may be more comfortable in use. Heater 200 can also heat the sonotrode and reduce the viscosity of the composition, thereby making it flow more easily and making it easier to spray.
By way of example, heater 200 may comprise an electric resistance heater 210 that can be incorporated in airflow generator 60 or placed upstream or downstream therefrom, as shown in FIG. 6.
By way of example, heater 200 may be fastened to airflow generator 60.
In one example, resistance heater 210 may be constituted by a Nichrome wire with a diameter of 0.51 mm and a length of 2.8 meters (m), that is wound into the shape of a spring, as shown in FIG. 13. Resistance heater 210 may be placed behind airflow generator 60, being fed with power, for example 36 watts (W). Such a resistance heater enables an air stream to be produced at a temperature of approximately 36° C. at 10 cm from the composition ejection surface. Notably conditioning means may comprise any suitable device for generating heat and/or cooling an airflow, and description with regard to resistance heater 210 is exemplary only. For example, a conditioning means may include a device configured to absorb heat for purposes of cooling an airflow from airflow generator 60.
Nozzle 65, airflow generator 60, and heater 200 may be secured to one another prior to being assembled within box 2. Thus, these elements may constitute a one-piece assembly that may be easy to mount in box 2. Such elements may be disposed in alignment one behind another. In some embodiments, the alignment of these elements may make device 1 relatively compact.
By way of example, the temperature at which the hot air leaves the nozzle 65 may lie in the range 30° C. to 40° C., and may be ideally about 37° C.
Where desired, the outlet temperature of the air may be regulated by having a temperature sensor present that is exposed to the hot air stream and that is associated with an electronic regulation loop.
Device 1 may be arranged so as to enable the user to select between operation in which the air blown by device 1 is heated and operation in which the air blown by the device is not heated.
By way of example, this selection may be made using a selector that may be actuated by the user, the selector being controlled by pressing to a greater or lesser extent on pushbutton 3 that triggers spraying, for example.
In an example, moderate pressure on the pushbutton 3 may trigger spraying with air being blown at ambient pressure, while greater pressure may trigger spraying with hot air being blown.
Heater 200 may switch on at substantially the same time as the fan is switched on and it may switch off at substantially the same time likewise, or the respective switching of heater 200 and of airflow generator 60 may be deferred in time.
Spray device 1 may be arranged to switch to a stand-by mode in the absence of action on pushbutton 3 for a predefined duration. Causing device 1 to return to normal operation may then occur once pressure is applied on pushbutton 3, or the general on/off switch 22 is operated, for example.
The body of nozzle 65 may be provided with a lateral opening 75 for passing a composition feed tube 55, and it may house a support 78 that may hold a piezoelectric transducer 80.
Transducer 80 may be mechanically coupled to a sonotrode 82 serving to amplify the electromechanical vibration of transducer 80, which vibration may be radial or longitudinal, so as to transmit the vibration to the ejection surface 4, which surface is defined by an end collar of the sonotrode 82.
In some embodiments, this surface may be machined in aluminum, but other materials could be used, for example other metals or alloys.
The rear face of sonotrode 82 is adhesively bonded to transducer 80, however it could be fastened in some other way, in particular by mechanical means such as screw fastening.
By way of example, the body of the nozzle 65 is circularly cylindrical and it may be molded out of a thermoplastic material.
At the front, nozzle 65 may present a converging portion 85 terminating in an opening 90 on the same axis X as the axis of sonotrode 82. This opening 90 may be circular in the example described, with a diameter lying in the range 14 mm to 20 mm, e.g., of the order of 16 mm.
Converging portion 85 projects into a setback 98 in box 2, formed by assembling together half-shells 2a and 2b, with the bottom of setback 98 defining an opening 97 that may locally match the outside section of nozzle 65.
In the example shown, the stream of air blown by nozzle 65 may be not deflected by the remainder of box 2, where the setback 98 presents sufficient width.
The air blown by airflow generator 60 may leave via the opening 90 to constitute a stream of air that is directed generally along the axis X.
As can be seen in FIG. 6 in particular, ejection surface 40 projects from the plane P of opening 90 by a distance d. The plane P of opening 90 may be substantially perpendicular to the axis X.
By way of example, the distance d may lie in the ranges 2 mm to 4 mm, range 2 mm to 3 mm, or 2.2 mm to 2.9 mm. In particular opening 90 may have a diameter of about 16 mm. Such values may enable a relatively uniform spray to be obtained with little loss at a distance 5 cm or even 10 cm from ejection surface 4.
A distance d lying outside the above range can lead to the spray being less uniform, for example with a central void and/or leaving a spot of composition that is less precise.
By way of example, support 78 may be molded as a single piece of thermoplastic material, and it includes a portion 92 designed to engage as a force-fit in central opening 72 through stopper 70 until a shoulder 93 of support 78 comes into abutment against bottom face 94 of stopper 70.
At its end opposite from mounting portion 92, support 78 may have elastically-deformable tabs 100, e.g., four tabs, each provided with an end tooth 101, which may serve to hold sonotrode 82 and transducer 80 by snap-fastening, or other suitable methods, as shown in FIGS. 5 and 6.
In addition to holding sonotrode 82, support 78 may also contribute to achieving distribution of the air stream inside nozzle 65 around sonotrode 82.
In the example described, transducer 80, which may be annular in shape, may be sandwiched between an O-ring gasket 101 and rear face 112 of sonotrode 82.
A recess 114 is formed in rear face 112 for passing a first power supply wire to sonotrode 82, contacting the face of may be transducer 80 adjacent to sonotrode 82, its other face may be electrically connected to a second power supply wire.
In the example described, apart from the recess 114, sonotrode 82 may be a body of revolution about the axis X.
Various transducers may be used. A transducer 80 including a piezoelectric ceramic that is suitable for the present disclosure may be constituted, for example, by that sold by the supplier Ferroperm under the reference 26132. It comprises a PZ26 piezoelectric ceramic in the form of a ring having an outside diameter of 20 mm, an inside diameter of 3.8 mm, and a thickness of 2 mm.
O-ring 110 rests on a shoulder 116 of support 78, as can be seen in FIG. 6, and transducer 80 may bear via its face opposite from sonotrode 82 on the O-ring 110, close to its radially outer edge.
O-ring 110 may enable sonotrode 82 and transducer 80 to be mounted substantially without clearance on the support 78.
At its rear end, sonotrode 82 may include a first enlarged cylindrical segment 120 defining a shoulder 125 on which teeth 101 can catch.
Sonotrode 82 extends forwards beyond shoulder 125 in the form of a frustoconical portion 130 that is connected via a fillet 131 to a second cylindrical segment 132 about the axis X. This cylindrical segment 132 may be connected by a fillet 134 to an end collar 140 having a front face that is generally perpendicular to the axis X and that may define composition ejection surface 4.
The diameter D of first cylindrical segment 120 may lie for example in the range 18 mm to 22 mm, e.g. being 20 mm, By way of example, this diameter D corresponds substantially to the greatest diameter of the transducer 80. In a variant, the transducer 80 presents a diameter of 15 mm.
The length l0 of the cylindrical segment 120 may lie, for example, in the range 1.5 mm to 5.5 mm, being equal to 3.5 mm, for example.
The greatest diameter D2 of the frustoconical portion 130 may lie, for example, in the range 15.5 mm to 19.5 mm, and is for example equal to 17.5 mm, and the smallest diameter D3 of the frustoconical portion 130 may lie, for example, in the range 8 mm to 12 mm, and is for example equal to 10 mm. The angle α at the apex of the frustoconical portion 130 may be 30°.
The radius of curvature of the fillet 131 may lies, for example, in the range 2 mm to 3 mm and may be equal to 2.5 mm, while the radius of curvature of the fillet 134 may lie, for example, in the range 1 mm to 2 mm, and may be equal to 1.5 mm.
A diameter D7 of the end collar may lie, for example, in the range 7 mm to 13 mm, and may be equal to 10 mm.
In some embodiments, the rear face of end collar 140 may terminate substantially perpendicularly to the axis X.
A thickness of the collar may be constant from its periphery over an annular range of width Δr, measured radially, and may lie in the range 0.2 mm to 2 mm, for example, equal to 0.5 mm.
A ratio D7/D1 may lie, for example, in the range 7/6 to 13/4 while the ratio D7/e may lie in the range 70/6 to 130.4, for example.
One of skill in the art will recognize that the present disclosure is not limited to the shape of end collar shown in the drawing and other shapes are possible, for example an elliptical shape, among others. Under such circumstances, the term “diameter” applies to the circle that circumscribes the collar.
In the example described, sonotrode 82 may be made with a rear endpiece 150 for connection to feed tube 55, the endpiece 150 being a single piece. For example, such fabrication may involve machining endpiece 150 together with the remainder of sonotrode 82. Tube 55 may be engaged as a force-fit on the endpiece 150, for example.
A composition feed channel 160 may pass through sonotrode 82 along the axis X. A first portion 160a of channel 160 may include a constant inside diameter from the bottom end 162 of endpiece 150 to a point 165 situated within second cylindrical segment 132, where said portion 160a may be connected to a narrow portion 160b via a frustoconical bore 160c. 
In its largest diameter portion 160a, an inside diameter D5 of channel 160 may lie, for example, in the range 1 mm to 3 mm and may be equal to 1.5 mm, while a diameter D6 of the narrow portion 160b may lie, for example, in the range 0.4 mm to 0.8 mm, and may be 0.6 mm.
The presence of largest diameter portion 160a may make it easier to machine channel 160 and may assist in reducing head loss. The presence of narrow portion 160b may lead to performance that is improved in terms of the quality of the resulting spray.
A length l7 of narrow portion 160b, as measured along the axis X, may lie, for example, in the range 2 mm to 5 mm, and may be equal to 3 mm, for example.
Transducer 80 may be excited at a frequency lying, for example, in the ranges 30 kHz to 200 kHz, and more particularly 60 kHz to 200 kHz. Pump 53 may deliver the composition for spraying to ejection surface 4 via channel 160 passing through sonotrode 82.
The excitation frequency of transducer 80 may be constant, or, alternatively, may be servo-controlled so as to maximize the amplitude of vibration at ejection surface 4, which may in turn maximize spraying effectiveness.
The electronic components of the device may comprise an electronic circuit that serves to perform this function.
At the end of spraying, where appropriate, the operation of the pump 53 may include a reversal of the direction of rotation of the motor for a short period of time in order to cause backflow of the composition present in channel 160 and thereby reduce the risk of the composition drying and plugging channel 160.
When a voltage is applied to transducer 80 via its first and second power supply wires, transducer 80 may vibrate, and in some embodiments, vibrates radially relative to the axis X. Vibrations generated in this way may propagate with amplitude being amplified in sonotrode 82 until it reaches ejection surface 4, which itself vibrates axially in bending.
Under the effect of the vibration, end collar 140 may deform, and the oscillation of collar 140 causes droplets of composition to be ejected over its entire circumference.
The mean size of the droplets delivered may lie, for example, in the range 20 μm to 30 μm.
The droplets of ejected composition may be entrained by the stream of air leaving opening 90 towards the surface for treatment, and they reach this surface in the form of droplets.
The delivery rate of the composition may lie, for example, in the range 0.5 g/min to 10 g/min. depending on the viscosity of the composition to be sprayed.
In some embodiments, a device of the present disclosure may enable spraying of a spot of composition having a diameter of about 40 mm to be formed in uninterrupted and uniform manner on the region to be treated.
In the example of FIG. 10, the particular values given for the dimensions of sonotrode 82 apply to a frequency f of 100 kHz.
For a different frequency f′, the dimensions may be modified, on a first approach, by a factor f/f′.
FIG. 11 shows another embodiment of sonotrode 82 consistent with the present disclosure, and designed to operate a frequency of 60 kHz. This sonotrode 82 differs from that shown in FIG. 10 in its dimensions and in the shape of the body 290 situated behind the cylindrical portion 132.
In such an embodiment, sonotrode 82 may include an inside thread 220 that enables a vibration generator retention bolt 250 to be fastened, e.g., constituted by two piezoelectric ceramics 280 mounted opposite ways round.
A length l7 of the narrow portion 160c may be 3.5 mm, for example. A length of cylindrical surface 225 from the end face opposite from collar 140 to a shoulder 226 of body 290 may equal approximately 18 mm, for example, and a distance of shoulder 226 to base 295 of a frustoconical portion 227 adjacent to the cylindrical portion 132 may, for example, be equal to 7 mm.
The housing 229 receiving the bolt 250 communicates with two successive bores 230 and 231 of respective decreasing diameters, e.g., respectively equal to 4 mm and 2.5 mm.
Bolt 250 may include a central opening enabling the composition for spraying to be delivered, and it may include an endpiece 300 for connection to tube 55.
One of skill in the art will recognize that the present disclosure is not limited to the embodiments described herein.
For example, in some embodiments, the composition may be fed via a needle that delivers the composition directly to the inside of sonotrode 82, set back from the composition outlet orifice.
The narrow portion of the channel may be formed by fitting a flow constrictor within sonotrode 82, such as for example a small sleeve forced into a channel of appropriate diameter in sonotrode 82.
Box 2 of device 1 may be of other shapes, in particular it may have the shape of a pen, for example.
Where appropriate, box 2 handled by the user may be connected via an electric cable to a base that includes at least one electrical power supply, e.g., a charging device.
In some embodiments, feed channel 160 may open out via a plurality of orifices onto ejection surface 4. These orifices may be disposed, for example, in an axially symmetrical configuration. The narrow portion of the channel may be situated upstream from channels communicating with the orifices, or in some embodiments, each branch of channel 160 leading to an orifice may include its own narrow portion.
Ejection surface 4 of sonotrode 82 may receive surface treatment, e.g., for the purpose of reducing its surface tension. For example it may receive a deposit of polytetrafluoroethylene (PTFE) or it may have a mirror polish among other things.
Where appropriate, device 1 may be arranged to enable the projection d of ejection surface 4 relative to the opening 90 to be adjusted. This can improve focusing of the spray.
In some embodiments, device 1 may be used for spraying a composition into the atmosphere.
The term “comprising a” should be understood as being synonymous with “comprising at least one” unless specified to the contrary.
The value ranges should be understood as including the limit values, unless specified to the contrary.
Although the examples herein have been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present disclosure. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present disclosure as defined by the appended claims.

## Claims

1. A device for spraying a cosmetic or dermatological composition, comprising a casing suitable for handling by a user to spray the composition onto skin or onto other human keratinous materials, and further comprising:
a container containing the composition for spraying;
an ultrasound spray head including a sonotrode;
an airflow generator for creating a stream of air for entraining a spray of composition particles atomized by the spray head;
a conditioning device for modifying a temperature of the stream of air, the conditioning device being placed upstream from the airflow generator and configured to be switched on simultaneously with the airflow generator; and
a pump feeding the sonotrode with the composition.

2. A device according to claim 1, wherein the conditioning device enables the temperature of the stream of air to be raised or lowered, and wherein the spray head is located downstream from the conditioning device.

3. A device according to claim 1, wherein the spray head, the airflow generator, and the conditioning device are in alignment.

4. A device according to claim 1, wherein the device is arranged to raise the temperature of the stream of air to more than 30° C.

5. A device according to claim 1, wherein the device is arranged to raise the temperature of the stream of air to more than 35° C.

6. A device according to claim 1, wherein the temperature of the stream or air is less than or equal to 40° C.

7. A device according to claim 1, wherein said airflow generator comprises a fan.

8. A device according to claim 1, wherein the conditioning device includes a heater device having a heater resistance.

9. A device according to claim 1, wherein a flow rate of the stream of air ranges from 4 m3/h to 7 m3/h.

10. A device according to claim 1, the composition being at least one of a makeup composition, a self-tanning agent, a composition including a hair agent, and a sunscreen composition.

11. A device according to claim 10, the composition being a foundation.

12. A method of cosmetically treating human keratinous materials, wherein a composition is sprayed and entrained towards the materials to be treated by a stream of hot or cold air by a device as defined in claim 1.

13. A method according to claim 12, the composition being a foundation sprayed onto skin.

14. A method according to claim 12, the composition being a hair agent sprayed onto hair.

15. A method according to claim 12, wherein a flow rate of the composition sprayed ranges from 0.5 g/min to 10 g/min.

16. A method according to claim 12, wherein a mean size of the particles of composition ranges from 20 μm to 30 μm.

17. A method according to claim 12, wherein a temperature of the stream of air ranges from 30° C. to 40° C.

18. A method according to claim 12, the method comprising the following steps and the composition being atomized by a sonotrode:
i) putting a fan into operation to create a stream of air for entraining particles of composition,
ii) after a predefined delay, setting the sonotrode into vibration by a transducer, and
iii) after another delay setting a pump into operation for feeding the sonotrode with composition.

19. A device for spraying a cosmetic or dermatological composition chosen from at least one of a makeup composition, a self-tanning agent, a composition including a hair agent, and a sunscreen composition, the device comprising a casing suitable for handling by a user to spray the composition onto skin or onto other human keratinous materials, and further comprising:
a container containing the composition for spraying;
an ultrasound spray head including a sonotrode;
an airflow generator for entraining a spray of composition particles atomized by the spray head; and
a heater device arranged to raise a temperature of an outgoing stream of air from the spray head to more than 30° C. for modifying the temperature of the outgoing stream of air; and
a pump feeding the sonotrode with the composition.

20. A device for spraying a cosmetic or dermatological composition chosen from at least one of a makeup composition, a self-tanning agent, a composition including a hair agent, and a sunscreen composition, the device comprising a casing suitable for handling by a user to spray the composition onto skin or onto other human keratinous materials, and further comprising:
a container containing the composition for spraying;
an ultrasound spray head including a sonotrode;
an airflow generator for entraining a spray of composition particles atomized by the spray head; and
a conditioning device for modifying a temperature of an outgoing stream of air from the spray head;
the device being arranged in such a manner as to enable the user to select between an operation in which the air blown by the device is heated, and an operation in which it is not heated; and
a pump feeding the sonotrode with the composition.