Patent Publication Number: US-2006006200-A1

Title: Device for dispensing a product

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
      This document claims priority to French Application Number 04 51499, filed Jul. 12, 2004 and U.S. Provisional Application No. 60/601,603 filed Aug. 16, 2004, the entire contents of which are hereby incorporated by reference. 
    
    
     FIELD OF THE INVENTION  
      The present invention relates to a device for dispensing a product, with a pressurized container equipped with an additional gas intake.  
     BACKGROUND OF THE INVENTION  
      Discussion of Background  
      Dispensing devices of the aerosol type which include a container containing a product in liquid form and a propellant are known. The container is equipped with a valve for letting out the liquid under pressure. This valve is fixed to a valve cup, in such a way that the fixed valve body opens into the container and a moving element opens to the outside of the container, with the opening of the valve being brought about by depressing or tilting the moving element in the valve body. The displacement of the moving element of the valve is generally accomplished using a push-button to press against the moving element of the valve, and the push-button can be displaced manually by the user in order to actuate the valve. The push-button generally includes a duct for ejecting the product that is to be dispensed and an outlet orifice. A dip tube may be fixed to the valve body to allow the valve body to be supplied with liquid that is to be dispensed, even when the liquid level is low, when the product is dispensed “head up”.  
      Devices of the aerosol type allow the product to be atomized into the form of a spray or alternatively allow the product to be dispensed in the form of a foam or mousse.  
      Document FR 2 114 497 describes, for example, a device for dispensing shaving foam which includes a container containing the product which is to be dispensed and a liquefied propellant. In order to maintain sufficient pressure in the container throughout the life of the device, reservoirs are provided within the container to hold the propellant in a concentrated form so as to release it gradually in stages as the pressure reduces upon each use.  
      Devices for atomizing a product into the form of a spray may be equipped, at the valve body, with an additional gas intake (AGI) which allows a fraction of the pressurized gas contained in the container to be drawn off the top of the product in order therefore to facilitate the ejection of the product that is to be atomized and encourage the atomization of the product. The additional gas intake is generally in the form of an orifice formed in the valve body and opening into the upper part of the container containing the gaseous phase of the propellant used to pressurize the product. The AGI has the function of increasing the gas content of the dispensed mixture. U.S. Pat. No. 4,417,674 describes an example of such a device.  
      When the propellant is a compressed gas, for example compressed air, it is necessary to have a very high initial pressure in order to have sufficient pressure at the end of use of the device. However, there is a risk that such a pressure will be incompatible, for example, with legislation, regulatory requirements or standards in this field. Furthermore, in the case of a container made of a thermoplastic material, the variation in pressure that would occur between the first use and the last use would be detrimental to the overall performance of the device.  
      Better pressurization is achieved when the propellant is a liquefied gas, namely a gas containing both a liquid phase and a gaseous phase above the liquid phase. However, when the propellant in the form of a liquefied gas that cannot mix with the product is in the same container as the product, the propellant in the liquid form may be dispensed particularly when the device is in horizontal position. This is because, in this position, the end of the dip tube may dip into the liquid phase of the propellant which means that the liquid propellant can be sprayed. The propellant therefore leaves the device in liquid form and the user might not notice that he or she is dispensing propellant instead of the product. A significant amount of propellant may thus escape from the container and this may soon adversely affect atomization performance.  
      If there is a desire to be able to dispense the product in all positions, it is necessary for the product to be packaged separately from the propellant which keeps the product under pressure. In order to do this, the product may be packaged in a flexible-walled pouch in communication with the valve. The propellant is packaged in a volume formed between the exterior surface of the pouch and the interior wall of the container. Alternatively, the product can be kept separate from the propellant by means of a piston, which slides in a sealed manner against the interior surface of the container. However, such devices having separating elements are relatively expensive.  
     SUMMARY OF THE INVENTION  
      It is one of the objects of the invention to provide a device that enables the problems mentioned hereinabove with reference to be solved in full or in part.  
      It is another object of the invention to provide a device that allows a product to be atomized in the form of a good-quality spray throughout the service life of the device.  
      Other objects will become apparent from the detailed description herein.  
      According to the invention, a device for packaging and dispensing, under pressure, a product, particularly a cosmetic product, is provided which includes a container containing the product to be dispensed under pressure. A propellant is provided in the form of a liquefied gas and includes a gaseous phase and a liquid phase. At least one retaining member is able to trap the liquid phase of the propellant, and the retaining member includes at least one portion that is permeable to the gaseous phase of the said propellant. In addition, a valve is mounted on the container and includes a body having a first passage able, when the device is in a first position, to cause the product contained in the container to enter the valve body when the valve is actuated, and a second passage able, when the device is in the first position, to cause the propellant contained in gaseous form in the container to enter the valve body when the valve is actuated.  
      By using a propellant in the form of a liquefied gas, a small amount of propellant, e.g. just one drop of gas, can be enough to pressurize the container. Furthermore, since the liquid phase of the propellant gas is at least partially held within the retaining member, the risks of the propellant in liquid form being dispensed are low, even when the container is in a horizontal position.  
      According to a preferred example, the retaining member can be configured to absorb all of the liquid phase of the propellant so that the propellant in liquid form can never be dispensed.  
      The first passage can be connected to a dip tube which can extend, for example, as far as the bottom of the container.  
      By way of example, the propellant can be chosen from the group consisting of alkanes, particularly butane, isopropane, isobutane, fluorinated compounds, particularly difluoroethane  152   a , tetrafluoroethane  134   a  and dimethylether.  
      Also by way of example, the propellant/product weight ratio by weight is preferably between 10 and 1 to 1 (10:1 to 1:1) inclusive, and more preferably between 2 and 1 to 1 (2:1 to 1:1) inclusive.  
      The retaining member can be made of a material and/or with a physical structure which are chosen according to the nature of the substance or substances contained in the container. For example, the retaining member can be formed according to the nature of the propellant and the quantity of gas that needs to be released by desorption, bearing in mind, for example, the configuration of the valve and the volume that the gas released by desorption is likely to occupy, and the pressure to be present in the container.  
      For example, the retaining member can include a porous material. The retaining member can also include a material the chemical nature of which allows it to absorb a propellant gas contained in the fluid.  
      By way of example, the retaining member can include a cellular material, for example a foam or a frit, particularly a frit of high porosity including pores of a size that may vary, for example, from approximately 5 to 20 μm. This frit may, for example, be a frit of high density polyethylene, of polypropylene or of PVDF (polyvinylidene fluoride).  
      Also by way of example, the retaining member can include fibres of polyamide, particularly of Nylon®.  
      The retaining member can also include a silicone, particularly when the propellant is butane, isobutane, difluoroethane  152   a , tetrafluoroethane  134   a , dimethylether or a mixture of at least two of these compounds, because of the affinity there is between silicone and the propellant.  
      The retaining member can be in the form of a body that is free inside the container. Alternatively, the retaining member can be fixed inside the container, for example to an internal wall of the container, such as the bottom wall of the container or to the dip tube. A device such as a stop, can be provided in order to immobilize the retaining member inside the container. Alternatively, the retaining member can be bonded or welded. Other attachment expedients could also be used.  
      In a disclosed example, the second passage can be an orifice made in the sidewall of the valve body. The aforementioned orifice may have a diameter, for example, of between 0.1 and 0.5 mm inclusive and more preferably of between 0.2 and 0.4 mm inclusive.  
      The valve may be configured to be actuated by a depressing movement or, alternatively, by a tilting movement.  
      The device can include a member for actuating the valve and dispensing the product under pressure via at least one dispensing orifice situated, for example, inside a nozzle, preferably a swirl-inducing nozzle.  
      The container can be made of aluminium or of tinplate, for example. Alternatively, the container may be made of a thermoplastic, particularly of PET/PEN. The container is preferably cylindrical or spherical in shape.  
      The device according to the invention is particularly advantageous for the packaging and dispensing under pressure of a product which, when dispensed via the valve, forms a milk or a foam or a spray. By way of example, the product can be a deodorant spray, a makeup product, particularly a foundation, or a product to be applied to the hair, particularly a styling spray or a lacquer.  
      As should be apparent, the invention can provide a number of advantageous features and benefits. It is to be understood that, in practicing the invention, an embodiment can be constructed to include one or more features or benefits of embodiments disclosed herein, but not others. Accordingly, it is to be understood that the preferred embodiments discussed herein are provided as examples and are not to be construed as limiting, particularly since embodiments can be formed to practice the invention that do not include each of the features of the disclosed examples. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      In addition to the features discussed above, the invention can include a number of additional features which will be explained hereinafter, with regard to nonlimiting exemplary embodiments which are described with reference to the attached figures, which:  
       FIG. 1  depicts, in cross-section, a first embodiment of the device according to the invention during head-up use;  
       FIG. 2  depicts a partial cross-section of the device of  FIG. 1  in the closed position;  
       FIG. 3  depicts, in cross-section, the device of  FIG. 1  during head-down use; and  
       FIG. 4  depicts, in cross-section, a second embodiment of the device according to the invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      The device  100  depicted in its entirety in  FIG. 1  includes, by way of example, a cylindrical container  10  made of tinplate. Also by way of example, the container can be made of aluminium or of a thermoplastic, particularly of PET/PEN.  
      This container  10  contains a product P to be atomized under the pressure of a propellant gas G such as isobutane, difluoroethane  152   a , tetrafluoroethane  134   a  or dimethylether, for example.  
      The container  10  includes, at the upper part, an opening  11  into which a cup  12  is, for example, crimped in a conventional way. A valve  20  is fixed by crimping into a central housing of the cup  12 . The other end of the container  10  is closed by a concave bottom.  
      The valve  20  includes a valve body  21  defining a chamber  22  in which there is engaged a valve stem  23 , having a longitudinal axis X, able to move in the chamber  22  between a valve-closed position illustrated in  FIG. 2 , and an open position illustrated in  FIGS. 1 and 3 .  
      The valve stem  23  is equipped, at its end emerging from the valve body  21 , with a push-button  30 . This push-button  30  is provided with an interior duct of passageway  31  which opens via a spray orifice  32 . This spray orifice could be delimited by one or more nozzles with swirl-inducing ducts for example, according, for example, to the type of aerosol desired and the nature of the product being sprayed.  
      An annular seal  33  is interposed between the valve body  21  and the cup  12 .  
      A dispensing duct or passageway  24  is provided in the valve stem  23 . This duct emerges at one end in the interior duct  31  of the push-button  30  and at the other end onto a lateral surface of the valve stem  23 , via a radial orifice  25 .  
      In the illustrated example, the valve stem  23  includes, under the radial orifice  25 , an annular portion  26  the periphery of which is equipped with a lip  26   a . A spring  40 , when there is no stress exerted on the valve stem, forces the free end of the annular lip  26   a  to be pressed or urged in a sealed fashion against the seal  33  so that an annular space  22   a  is delimited by the annular portion  26 , the lip  26   a  and the annular seal  33 , as can be seen in  FIG. 2 .  
      When the valve is in the closed position illustrated in  FIG. 2 , the lip  26   a  presses in a sealed manner against the annular seal  33  so that the radial orifice  25  does not communicate with the chamber  22 . When the valve stem  23  is tilted relative to the axis X, the annular lip  26   a  moves away from the seal  33 , to a certain angular extent, and this allows a communication to be established between the inside of the valve body and the annular space  22   a  and therefore between the inside of the valve body and the inside of the stem  23  via the radial orifice  25 . The helical spring  40  returns the valve stem  23  to the closed position when this valve stem is released.  
      The valve stem  23  includes, in the lower part, under the annular portion  26 , a cylindrical portion  27  having axis X acting as a guide for the spring  40 .  
      The valve body  21  includes, in the lower part, an endpiece  28  onto which a first end  51  of a dip tube  50  is fixed. The endpiece  28  opens into this dip tube via a first passage in the form of an orifice  28   a  having circular cross section, for example. The second end  52  of the dip tube  50  is situated more or less at the bottom of the container.  
      The valve body  21  also comprises a second passage in the form of an additional gas intake (AGI) orifice  29 , with the orifice  29  being formed in the sidewall of the valve body and opening into the upper part of the container in the illustrated example. The orifice  29  may alternatively be formed in the bottom of the valve body and have an axis parallel to the axis X, for example.  
      The AGI has the function of enhancing the gas content of the dispensed mixture, with the mixture of liquid and propellant gas being formed in the chamber and conveyed to the spray orifice when the device is used head up. It also allows the passage of the product, when the device is used head down or inverted with respect to the head up position.  
      A retaining member  60  is provided, in the example illustrated, in the form of free bodies of silicone able to absorb the propellant gas in the liquefied state G, because of the affinity there is between the silicone and the propellant. The silicone bodies  60  are free to move inside the container and, in particular, in the liquid product P.  
      The retaining member  60 , by desorption of the propellant gas G, allows the pressure provided within the container to be increased once the valve stem  23  has returned to its closed position. The retaining member  60  is configured to absorb all the liquid phase of the propellant to prevent the latter from being dispensed in liquid form. Furthermore, the retaining member  60  is configured so that the gaseous volume released by desorption is enough for the product P to always be under pressure throughout the life of the product.  
      According to a particular example, the container contains 30 g of foundation and 60 g of isobutane. The container also contains three blocks of silicone which in total represent a volume of approximately 20 cm 3 .  
      To produce the device, the product P is introduced into the container together with the blocks of silicone. The valve is then crimped onto the cup. Then, via the valve, the quantity of liquefied propellant gas is introduced, and the gas is absorbed and retained in the silicone blocks. Depending on the pressure inside the container, the liquid gas vaporizes above the product, and spreads out in the container thus exerting pressure on the product P which is thus pressurized adequately.  
      Each time the valve  20  is actuated via the push-button  30 , the product P leaves under pressure, particularly in the form of a spray. Each time some product P is dispensed, the pressure in the container decreases, and this causes a corresponding quantity of liquefied gas contained in the silicone blocks to vaporize and causes an adequate pressure to be maintained throughout the life of the product.  
      In the head-up position illustrated in  FIG. 1 , the valve opens in response to actuation of the push-button. The product P is thus driven under the pressure of the propellant, via the dip tube, into the valve. At the same time, the propellant in gaseous form present in the upper part of the container above the product P also arrives in the valve body via the additional gas intake orifice  29 . A product/propellant mixture is therefore dispensed via the spray orifice  32 .  
      In the head down position illustrated in  FIG. 3 , the container is inverted with respect to the  FIG. 1  position, and the product this time arrives in the valve via the orifice  29 . The propellant in gaseous form present above the product, this time towards the bottom of the container, is conveyed into the valve body via the dip tube.  
      If, however, the user attempts to actuate the valve when the device is in the horizontal position and the end  52  of the dip tube and the additional gas intake orifice  29  are not in contact with the product, the propellant will be dispensed alone in gaseous form. However, the user will soon realize that he or she is not dispensing product and will stop actuating the valve or alter the position of the device.  
      The device illustrated in  FIG. 4  differs from the one which has just been described in that the free silicone bodies constituting the retaining element  60  are replaced by a block of open-cell foam  60  fixed or coupled to the bottom of the reservoir, for example by bonding or another suitable expedient.  
      Here again, the block of foam contains the liquid phase of the liquefied gas, for example an isobutene, which provides a vapor above the product P, to exert enough pressure to pressurize the contents P.  
      Alternatively, also by way of example, one or more retaining members can be fixed or attached elsewhere, for example to a sidewall of the container, to the dip tube or alternatively to the exterior wall of the valve body. Components that make up the various parts of the container may also, at least in part, constitute retaining members.  
      In the foregoing detailed description, reference has been made to some preferred embodiments of the invention. However, variations can be made thereto without departing from the scope of the invention as claimed hereinafter. For example, the valve may in particular be configured to allow dispensing when the valve stem is depressed rather than tilted. It is also possible to provide a valve body with other forms or types.  
      Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.