Patent Publication Number: US-2015078117-A1

Title: Device for dispensing a mixture, preferably foam

Description:
TECHNICAL FIELD OF THE INVENTION 
     The present invention concerns the field of systems for dispensing mixed fluids. In particular, the present invention refers to a device for dispensing a mixture of two fluids that can be applied to a container holding these fluids, particularly for dispensing a mixture in the form of foam. 
     DESCRIPTION OF THE STATE OF THE ART 
     The use of dispensing devices is known in the sector of equipment for dispensing products in the form of foam, wherein said dispensing devices are applied to deformable containers, usually made of plastic, which when pressed manually allow the foam to be dispensed therethrough. 
     In such dispensing systems foam is produced by properly mixing a given quantity of liquid and air taken from said containers. 
     The fields of application of these types of foam production and dispensing systems are the most varied. In the sector of cleaning foams are produced for cleaning bathrooms, windows, kitchen ovens, furniture, or for distributing soap, shampoo or face cleansers. As far as personal hygiene and health products are concerned, foam products are used, for example, for hand care, hair care, skin care, shaving, or again as toiletries for animals like cats and dogs. Furthermore, there are specific applications in the medical sector, for example sunscreen foams or similar products. 
     The systems of the known type consist of a dispensing device applied to the neck of a container. In the dispensing device it is possible to identify a chamber which, during the manual deformation of the container, receives the liquid drawn from the container through a thin tube and the air contained in the container itself. The mixture of liquid and air that reaches this chamber flows out of the same and is changed into foam thanks to the presence of a filtering element provided with suitable micro holes that allow the mixture to flow out in the form of foam, also depending on the viscosity characteristics of the liquid and on the quantity of air mixed with said liquid. These systems can be used keeping the container in both the upright and the overturned position. 
     The dispensing devices applied to the containers substantially consist of a supporting structure provided with means for coupling with the container&#39;s neck and with a suction unit suited to draw the fluids from the inside of the container and to produce the foam that is successively dispensed. 
     The foam generated in this way is conveyed towards the external environment through a suitable outlet duct. 
     The correct formation of the foam in terms of correct percentage of fluid and air in the foam itself depends on the type of fluid, in particular on its higher or lower viscosity. For different types of fluid it will therefore be necessary to provide devices that are different from time to time and allow mixing to be carried out with the correct and desired air/fluid ratio. 
     The dispensing devices belonging to the state of the art however pose some drawbacks. 
     A first drawback posed by said dispensing devices is represented by the fact that they are difficult to manufacture and that it is necessary to provide a plurality of different devices, one for each type of fluid used in the mixture. 
     Another drawback posed by these devices lies in that their operation changes depending on whether the container is positioned upright or overturned. 
     A further drawback posed by the devices of the known type is constituted by the flow resistance to which the fluids are subjected along the respective channels that convey them to the mixing chamber when the container is deformed. 
     Another drawback posed by the devices of the known type is constituted by the fact that the mixing chamber is filled with the fluids to be mixed in a non-homogeneous manner. This is mainly due to the special shape assumed by the channels that convey the fluids towards the mixing chamber. 
     It is the object of the present invention to overcome the above mentioned drawbacks. 
     In particular, it is a first object of the invention to provide a device for dispensing mixtures that makes it possible to reduce production costs compared to the devices of the known type. 
     It is another object of the invention to provide a device for dispensing mixtures that can be adapted to the characteristics of the fluid of which the mixture is made. 
     It is a further object of the invention to provide a device for dispensing mixtures that can be configured in such a way as to obtain the best mixture, as desired, by replacing/modifying the smallest number of elements making up the device. 
     It is another object of the invention to provide a device that makes it possible to reduce the flow resistance of the fluids to be mixed during the dispensing operation. 
     It is another object of the invention to provide a device that makes it possible to improve the fluid mixing operation inside the mixing chamber. 
     SUMMARY OF THE PRESENT INVENTION 
     According to a first aspect of the invention, therefore, the subject of the same is a device for dispensing mixtures, suited to be applied to a container that holds a first and a second fluid suited to be mixed together in order to obtain said mixture, said device comprising:
         a first body;   a second body associated with said first body;   a mixing chamber defined at least partially in said first body and/or in said second body;   a first duct suited to convey said first fluid towards said mixing chamber;   a second duct suited to convey said second fluid towards said mixing chamber;   a thin tube suited to define at least partially said first duct and comprising an end portion connected to said first or to said second body,
 
wherein said end portion of said thin tube is connected to said first body or to said second body in such a way as to define for said first fluid a main advance direction belonging to a longitudinal axis that intersects said mixing chamber.
       

     Preferably, the end portion of the thin tube has a substantially cylindrical shape that extends along said longitudinal axis. 
     In a first preferred embodiment, the end portion of the thin tube is accommodated in a housing seat provided in the first body or in the second body, said housing seat extending along said longitudinal axis. 
     The housing seat preferably has a portion that is substantially cylindrical in shape. 
     Advantageously, the housing seat is positioned centrally with respect to the first body or the second body in which it is obtained. 
     The dispensing device that is the subject of the invention properly comprises valve means suited to allow the flow of the first fluid in the thin tube to be blocked. 
     The valve means are preferably arranged upstream of the mixing chamber with respect to the main advance direction of the first fluid. 
     According to a preferred embodiment, the first duct comprises at least one section suited to convey the first fluid and defined by at least two surfaces facing each other and respectively belonging to the first body and to the second body. 
     According to another embodiment, the second duct comprises at least one section suited to convey the second fluid and defined by at least two surfaces facing each other respectively belonging to the first body and to the second body. 
     Advantageously, the device comprises snap connection means between the first body and the second body. 
     Preferably, the first body or the second body comprises means for connection to the container. 
     The device preferably comprises further valve means suited to restore the presence of air inside the container once the mixture has been dispensed. 
     According to a preferred embodiment, the device comprises a filtering element associated with the mixing chamber for the formation of the mixture. 
     According to a preferred embodiment, the first fluid comprises a liquid or a cream and the second fluid comprises air. 
     According to another preferred embodiment, the first fluid comprises air and the second fluid comprises a liquid or a cream. 
     The mixture obtained by means of the dispensing device of the invention is preferably a foam. 
     Advantageously, the first body is provided with means for connection to the container. 
     According to a second aspect of the present invention, the subject of the same is a system for dispensing a mixture, comprising a container suited to hold two fluids to be mixed and a dispensing device associated with said container and suited to mix said fluids and dispense said mixture, wherein said dispensing device is of the type described above. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further advantages, objects and characteristics of the present invention, as well as further embodiments of the same are defined in the claims and will be illustrated in the following description with reference to the attached drawings; in the drawings, corresponding or equivalent characteristics and/or component parts of the present invention are identified by the same reference numbers. In particular: 
         FIG. 1  shows a first embodiment of the dispensing device that is the subject of the invention applied to a container; 
         FIG. 2  shows a first longitudinal cross section view of the device of the invention shown in  FIG. 1 ; 
         FIG. 3  shows an exploded view of  FIG. 2 ; 
         FIG. 3A  shows an axonometric view of a detail of  FIG. 3 ; 
         FIG. 4  shows a second longitudinal cross section view along a different section plane of the device of the invention shown in  FIG. 1 ; 
         FIG. 5  shows a partial view of a variant embodiment of the device of  FIG. 1  in overturned position of use; 
         FIG. 6  shows a longitudinal cross section view of the device of the invention shown in  FIG. 5 ; 
         FIG. 7  shows an exploded view of  FIG. 6 ; 
         FIG. 8  shows a variant embodiment of  FIG. 2 ; 
         FIG. 9  shows an exploded view of  FIG. 8 ; 
         FIG. 9A  shows a variant embodiment of  FIG. 8 ; 
         FIG. 10  shows another variant embodiment of  FIG. 6 ; 
         FIG. 11  shows an exploded view of  FIG. 10 . 
     
    
    
     DETAILED DESCRIPTION OF THE PRESENT INVENTION 
     The examples of embodiment of the invention described below refer to devices for dispensing products in the form of a foam preferably resulting from the combination of a first fluid, typically in liquid form, with a second fluid, typically air, both present inside the container to which the device is applied. 
     It is clear that the proposed solution can be applied also to devices for dispensing foams where the composition of the two fluids can be different, as for example in the case in which the fluid used comes in the form of cream. 
     An example of embodiment of a system  1  for dispensing a mixture, denoted here below simply as a foam S, is shown in  FIG. 1 , in which a dispensing device according to the present invention, indicated as a whole by  10 , is applied to a container C holding the fluids to be mixed. 
     It can be observed that the container C of the invention is preferably a bottle made of a material that can be easily deformed by the pressure exerted by the hand that is grasping it, and is preferably made of a plastic material. 
     It is evident that this deformation can be obtained in any other manner, for example with the aid of special mechanisms suited to deform the external surface of the container C. 
     Said container C is filled with a first fluid F1 up to a suitable level, shown with a broken line in  FIG. 1 , while the remaining space above said fluid F1 will contain air, suited to constitute the second fluid F2 making up the foam S to be obtained. 
     The dispensing device of the invention  10  is applied to the neck of said container C, a mixing chamber  12  being defined within said dispensing device  10 , as is better explained below. The dispensing device  10  is provided with suitable ducts C1, C2 suited to convey the fluids F1, F2 to said mixing chamber  12 , where the mixed fluids will form the foam S that can be dispensed through a suitable outlet duct  20  of a spout  21 . 
     It should be noted that in the first embodiment illustrated in Figures from  1  to  4 , as well as in the embodiment illustrated in  FIGS. 8 and 9 , the operation of the dispensing system takes place with the container C in a substantially upright position, meaning in a position with the dispensing device situated in the upper part of the container C. Figures from  5  to  7  and  FIGS. 10 and 11 , instead, show variant embodiments of the device of the invention in which the dispensing system works with the container C in overturned position, meaning in a position with the dispensing device situated in the lower part of the container C. 
     It is evident that the dispensing system can operate indifferently in the upright and in the overturned position. In the two cases the same delivery ducts C1, C2 are intended to have opposite functions, meaning that the air delivery duct will serve as fluid delivery duct and the fluid delivery duct will serve as air delivery duct, with no need to substantially change the operation of the system of the invention. 
     With reference to the embodiment shown in  FIGS. 2 ,  3  and  4 , the dispensing device of the invention  10  comprises a first body or supporting structure  13 , provided with coupling means  13   a  for coupling with the container C. Said coupling means  13   a  preferably comprise a threaded portion suited to be engaged with a corresponding threaded portion that is present on the neck of the container C. 
     In variant embodiments of the invention, said coupling means may be of a different type, for example they can be of the type with snap coupling. 
     On top of the first body  13  there is a closing element  14  preferably ending with the spout  21  where the outlet duct  20  for the foam S is provided. 
     According to the example of embodiment shown in the figure, the closing element  14  is connected to the first body  13  through a snap connection obtained by means of an annular projection  17  belonging to the closing element  14  and housed in a corresponding annular cavity  18  belonging to said first body  13 . 
     In a variant embodiment of the invention, the first body  13  and the closing element  14  can be connected through different connection means or made in a single piece, for example through a thermoplastic moulding process. 
     The fluid mixing chamber  12  is defined in the centre area of the first body  13 . The mixing chamber  12  comprises a first mixing area  25  suited to receive the first fluid F1 through a first inlet  26  and the second fluid F2 through a second inlet  27 . 
     The first mixing area  25  preferably has the shape of a truncated cone on whose bottom walls said inlets  26 ,  27  for the fluids F1, F2 to be mixed are obtained. 
     The mixing chamber  12  then comprises a second mixing area  28  communicating with the first mixing area  25 . The second mixing area  28  has a preferably cylindrical shape and houses a diffuser element  29  and a filtering element  30 . The diffuser element  29  comprises at its centre a diffuser hole  31  suited to receive the mixture from the first mixing area  25  and to convey it towards the filtering element  30 . 
     According to the embodiment being described, there is just one diffuser hole  31  in a preferably central position with respect to the diffuser element  29 . In other variant embodiments, however, the diffuser element can be provided with one or more diffuser holes with different shape and position. Said concept can be extended to all the embodiments described with reference to the present invention. 
     The filtering element  30 , visible in the detail shown in  FIG. 3A , has a substantially cylindrical shape and has a centre area provided with suitable micro holes that allow the formation of the foam S comprising micro air bubbles F2 mixed with the fluid F1, also depending on the viscosity characteristics of the fluid F1. 
     The first body  13  is associated with a second body  32  suited to define at least part of the delivery ducts C1, C2 suited to convey the two fluids F1 and F2 towards the mixing chamber  12 . 
     According to the example of embodiment shown in the figure, the second body  32  is connected to the first body  13  through a snap connection obtained by means of an annular projection  33  belonging to the first body  13  and housed in a corresponding annular cavity  34  belonging to the second body  32 . 
     In a variant embodiment of the invention the first body  13  and the second body  32  can be connected through equivalent connection means, however suited to allow them to be mutually engaged and disengaged. 
     The first delivery duct C1 of the first fluid F1, that is, the duct C1 that conveys the liquid drawn from the bottom of the container C, preferably comprises a first cylindrical portion  35  of the second body  32  that substantially develops along a main axis X. At least one section  36  of said first cylindrical portion  35  defines a housing seat  37  for a thin tube  38  suited to draw the first fluid F1 from a position near the bottom of the container C, as can be seen in greater detail in  FIG. 1 . The upper end portion  39  of the thin tube  38  is therefore accommodated inside said housing seat  37 . 
     Preferably, the end portion  39  of the thin tube  38  is engaged in said housing seat  37  through mechanical interference. 
     Also the end portion  39  of the thin tube substantially develops along said main axis X. The first delivery duct C1 also comprises a second portion  45  for conveying the fluid from the first cylindrical portion  35  until it comes in proximity to the first inlet  26  of the mixing chamber  12 . 
     Inside the first delivery duct C1, and preferably at the level of the first cylindrical portion  35 , there are valve means  41  suited to allow the first fluid F1 to flow towards the mixing chamber  12  and suited to block its flow in the opposite direction, thus making it possible to maintain the fluid F1 inside the thin tube  38 . The valve means  41  preferably comprise a ball  42  suited to be arranged in an open and/or closed position with respect to a circular opening  43  in said first cylindrical portion  35 . 
     The second delivery duct C2 of the second fluid F2, that is, air, preferably comprises a shaped portion  50  of the second body  32  suited to convey the air present in the upper portion of the container C centrally towards the second inlet  27  of the mixing chamber  12 . 
     In variant embodiments of the invention, the second delivery duct C2 of the second fluid F2, that is, air, may comprise several shaped portions arranged circumferentially on the second body  32  and suited to convey the air present in the upper portion of the container C centrally towards the second inlet  27  of the mixing chamber  12 . 
     During operation, when the container C is pressed, the first fluid F1 and the second fluid F2 are subjected to pressure and conveyed towards the mixing chamber  12  through the respective delivery ducts C1, C2. 
     When the container C is pressed, the first fluid F1 is drawn by the thin tube  38  and directed along the first delivery duct C1 so that it reaches the mixing chamber  12 . 
     In particular, the first fluid F1 is conveyed and thrust inside the end portion  39  of the thin tube  38  towards the mixing chamber  12  substantially along an advance direction D1. Said advance direction D1 is substantially parallel to the main axis X. 
     At the same time, the air F2 is directed along the second delivery duct C2 so that it reaches the mixing chamber  12 , too. The foam S, which is successively dispensed towards the outside through the spout  21 , is formed in the mixing chamber  12 , in particular in the filtering element  30 . 
     When the container C is released, the first fluid F1 is sucked back along the thin tube  38  (vacuum effect). The valve means  41 , however, intervene with the ball  42  that closes the circular opening  43 . Consequently, the first fluid F1 is not completely sucked back into the container C but remains inside the thin tube  38 . Said fluid F1 inside the thin tube  38  will therefore be immediately ready for the successive dispensing operation to be performed by the user, which avoids the need for the container C to be pressed more than once in order to draw the first fluid F1 from the bottom of the container C before the foam S is dispensed. 
     The dispensing device  10 , as shown in  FIG. 4 , is furthermore provided with second valve means  51  suited to recover the air that operate while the container C is being released. Said valve means  51  make it possible to recover and restore the air portion that was ejected from the inside of the container C during the dispensing operation. Said valve means  51  comprise a ball  52  housed in a chamber provided with a hole  53  that is in communication with the outside. When the foam S is dispensed, the ball  52  closes the communication hole  53  while when the container C is released the ball  52  clears the communication hole  53 , allowing the air to be sucked and to return inside the container C. 
     According to the present invention, the advance direction D1 of the first fluid F1 inside the end portion  39  of the thin tube  38 , substantially parallel to the main axis X, intersects the mixing chamber  12 . In other words, the main axis X, around which the housing seat  37  of the thin tube  38  develops, intersects the mixing chamber  12 . 
     The end portion  39  of the thin tube  38 , the housing seat  37  of the thin tube  38  and the mixing chamber  12  are therefore substantially aligned and coaxial with respect to the main axis X. Furthermore, the housing seat  37  of the thin tube  38  is defined centrally with respect to the second body  32 . 
     Advantageously, the mixing chamber  12  is reached and filled by the fluids F1, F2 in a uniform manner, and not in a dishomogeneous manner, as is the case with the devices of the known type. 
     This makes it possible to improve the mixing of the two fluids F1, F2 inside the mixing chamber  12 . 
     Furthermore, the special geometric configuration makes it possible to reduce the flow resistance of the fluids F1, F2 to a minimum while the container C is pressed. 
     Still advantageously, the central position of the housing seat  37  allows the thin tube  38  to be comfortably assembled on the second body  32 . In fact, it is sufficient to centre the end portion  39  of the thin tube  38  with respect to the second body  32 , with no need to worry about the rotation of the second body  32 . This speeds up the assembly steps of the thin tube  38 , in the case of both manual and automatic assembly. 
     A variant embodiment of the dispensing system  100  of the invention is described with reference to Figures from  5  to  7 , and it mainly differs from the first embodiment described above owing to the fact that it works with the container C in overturned position. 
     In this case, as already explained, the first duct C1 serves as delivery duct for the air F1 and the second duct C2 serves as delivery duct for the fluid F2. 
     The container C will be filled with the fluid F2 until a suitable level is reached, while the remaining space above said fluid F1 will contain air that is suited to constitute the other fluid F2 making up the foam S to be obtained. 
     The dispensing device  110  of the invention comprises a first body or supporting structure  13 , provided with coupling means  13   a  for coupling with the container C. Said coupling means  13   a  preferably comprise a threaded portion suited to be engaged with a corresponding threaded portion present on the neck of the container C. 
     In variant embodiments, said coupling means may be of a different type, for example snap coupling means. 
     On the underside of the first body  13  there is a closing element  14  preferably ending with a spout  21 , where the outlet duct  20  for the foam S is provided. 
     According to the example of embodiment shown in the figure, the closing element  14  is connected to the first body  13  through a snap connection obtained by means of an annular projection  17  belonging to the closing element  14  and housed in a corresponding annular cavity  18  belonging to said first body  13 . 
     In a variant embodiment of the invention the first body  13  and the closing element  14  may be connected through different connection means or produced in a single piece, for example through a thermoplastic moulding process. 
     The fluid mixing chamber  12  is defined in the centre area of the first body  13 . The mixing chamber  12  comprises a mixing area  25  suited to receive the two fluids F1 (air) and F2 (liquid) from the respective delivery ducts C1 and C2 through a diffuser hole  31 . 
     Preferably, the mixing area  25  has substantially the shape of a cylinder on whose bottom wall there is said diffuser hole  31 . 
     The inside of the mixing area  25  houses a filtering element  30 . The diffuser hole  31  conveys the mixture of the two fluids F1 and F2 towards the filtering element  30 . The filtering element  30 , substantially the same as that shown in  FIG. 3A , has a substantially cylindrical shape and has a centre area provided with suitable micro holes that allow the formation of the foam S comprising micro air bubbles F1 mixed with the fluid F2, also depending on the viscosity characteristics of the fluid F2. 
     The first body  13  is associated with a second body  32  suited to define at least part of the delivery ducts C1, C2 suited to convey the two fluids F1 and F2 towards the mixing chamber  12 , and in particular towards the diffuser hole  31 . 
     According to the example of embodiment shown in the figure, the second body  32  is connected to the first body  13  through a snap connection obtained by means of an annular projection  33  belonging to the first body  13  and housed in a corresponding annular cavity  34  belonging to said second body  32 . 
     According to a variant embodiment of the invention, the first body  13  and the second body  32  can be connected using different equivalent connection means, however suited to allow them to be mutually engaged and disengaged. 
     The first delivery duct C1 of the first fluid F1, that is, the duct C1 that conveys the air from the container C, preferably comprises a first cylindrical portion  35  of the second body  32  that develops substantially along a main axis X. At least one section  36  of said first cylindrical portion  35  defines a housing seat  37  for a thin tube  38  suited to convey the first fluid F1. The lower end portion  39  of the thin tube  38  is thus accommodated inside said housing seat  37 . 
     Preferably, the end portion  39  of the thin tube  38  is engaged in said housing seat  37  through mechanical interference. 
     Also the end portion  39  of the thin tube develops substantially along said main axis X. The first delivery duct C1 also comprises a second portion  45  suited to convey the fluid F1 from the first cylindrical portion  35  until it comes in proximity to the diffuser hole  31 . 
     More particularly, a portion of said first delivery duct C1 is defined by two facing surfaces  54 ,  55  respectively belonging to said first body  13  and to said second body  32 . At least one space suited to allow the passage of the fluid F1 (air) is advantageously defined between the two facing surfaces  54 ,  55 . 
     Preferably, more spaces suited to allow the passage of the fluid F1 (air) are preferably defined between the two facing surfaces  54 ,  55 , said spaces being preferably arranged so that they are equally spaced angularly for more homogeneous delivery of the fluid F1 (air) towards the diffuser hole  31 . 
     Inside the first delivery duct C1, and preferably at the level of the first cylindrical portion  35 , there are valve means  41  suited to allow the first fluid F1 (air) to flow towards the mixing chamber  12  and suited to block the possible flow of the second fluid F2 coming from the diffuser hole  31  in the opposite direction inside the thin tube  38  during the release of the container C. 
     The valve means  41  preferably comprise a ball  42  suited to be arranged in an open and/or closed position with respect to a circular opening  43  in said first cylindrical portion  35 . 
     The second delivery duct C2 of the second fluid F2, that is, the liquid, preferably comprises a shaped portion  50  of the second body  32  suited to convey the liquid from the lower portion of the container C centrally towards the diffuser hole  31 . 
     In variant embodiments, the second delivery duct C2 of the second fluid F2, that is, the liquid, may comprise several shaped portions arranged circumferentially on the second body  32  and suited to convey the liquid from the lower portion of the container C centrally towards the diffuser hole  31 . 
     During operation, when the container C is pressed, the first fluid F1 and the second fluid F2 are subjected to pressure and conveyed towards the mixing chamber  12  through the respective delivery ducts C1, C2. 
     When the container C is pressed, the first fluid F1 (airs) enters the thin tube  38  and is directed along the first delivery duct C1 so that it reaches the mixing chamber  12 . 
     In particular, the first fluid F1 is conveyed inside the end portion  39  of the thin tube  38  towards the mixing chamber  12  substantially along an advance direction D1. Said advance direction D1 is substantially parallel to the main axis X. 
     At the same time, the liquid F2 is directed along the second delivery duct C2 so that it reaches the mixing chamber  12 , too. The foam S, which is successively dispensed towards the outside through the spout  21 , is produced in the mixing chamber  12 , in particular in the filtering element  30 . 
     The dispensing device  110 , analogously to what happens for the first embodiment, is furthermore provided with second valve means  51  that are suited to recover the air and are activated while the container C is being released. Said valve means  51  make it possible to recover and restore the portion of air that was ejected from the inside of the container C during the dispensing operation. Said valve means  51  comprise a ball  52  housed in a chamber provided with a hole  53  that communicates with the outside. 
     When the foam S is dispensed, the ball  52  closes the communication hole  53  while when the container C is released the ball  52  clears the communication hole  53  allowing the air to be sucked and to return inside the container C. 
     According to the present invention, the advance direction D1 of the first fluid F1 inside the end portion  39  of the thin tube  38 , substantially parallel to the main axis X, intersects the mixing chamber  12 . In other words, the main axis X, around which the housing seat  37  of the thin tube  38  develops, intersects the mixing chamber  12 . 
     The end portion  39  of the thin tube  38 , the housing seat  37  of the thin tube  38  and the mixing chamber  12  are therefore substantially aligned and coaxial with respect to the main axis X. Furthermore, the housing seat  37  of the thin tube  38  is defined centrally with respect to the second body  32 . 
     Advantageously, the mixing chamber  12  is reached and filled by the fluids F1, F2 in a uniform manner and not in a dishomogeneous manner, as is the case with the devices of the known type. 
     This makes it possible to improve the mixing of the two fluids F1, F2 inside the mixing chamber  12 . 
     Furthermore, the special geometric configuration makes it possible to reduce the flow resistance of the fluids F1, F2 to a minimum while the container C is pressed. 
     Still advantageously, the central position of the housing seat  37  allows the thin tube  38  to be comfortably assembled on the second body  32 . In fact, it is sufficient to centre the end portion  39  of the thin tube  38  with respect to the second body  32 , with no need to worry about the rotation of the second body  32 . This speeds up the assembly steps of the thin tube  38 , in the case of both manual and automatic assembly. 
     A variant embodiment of the dispensing system of the invention, which works with the container C arranged in the upright position, is described with reference to  FIGS. 8 and 9 . 
     The container C, not visible in the figure, is filled with a first fluid F1 up to a suitable level, while the remaining space above said fluid F1 will contain air, suited to constitute the second fluid F2 making up the foam S to be obtained, analogously to that which is shown in  FIG. 1 . 
     The dispensing device of the invention, indicated as a whole by  210 , is applied to the neck of said container C. 
     The dispensing device  210  that is the subject of the invention comprises a first body or supporting structure  13 , provided with coupling means  13   a  for coupling to the container C. Said coupling means  13   a  preferably comprise a threaded portion suited to be engaged with a corresponding threaded portion present on the neck of the container C. 
     In variant embodiments, said coupling means may be of a different type, for example snap coupling means. 
     On top of the first body  13  there is a closing element  14  preferably ending with the spout  21 , where the outlet duct  20  for the foam S is provided. 
     According to the example of embodiment shown in the figure, the closing element  14  is connected to the first body  13  through a snap connection obtained by means of an annular projection  17  belonging to the closing element  14  and housed in a corresponding annular cavity  18  belonging to said first body  13 . 
     According to a variant embodiment of the invention, the first body  13  and the closing element  14  can be connected through different connection means or obtained in a single piece, for example through a thermoplastic moulding process. 
     The fluid mixing chamber  12  is defined in the centre area of the first body  13 . The mixing chamber  12  comprises a mixing area  25  suited to receive the two fluids F1 (liquid) and F2 (air) from the respective delivery ducts C1 and C2. 
     The mixing area  25  has a substantially cylindrical shape and houses a diffuser element  29  and a filtering element  30 . 
     In a variant embodiment, shown in  FIG. 9A , the mixing area  25  houses only the filtering element  30 , while the diffuser element  29  can be omitted. 
     The diffuser element  29  comprises at its centre a first diffuser hole  31  suited to receive the mixture from a second diffuser hole  131  at the base of the mixing area  25  and to convey said mixture towards the filtering element  30 . 
     The filtering element  30 , substantially the same as that shown in  FIG. 3A , has a substantially cylindrical shape and has a centre area provided with suitable micro holes that allow the formation of the foam S comprising micro air bubbles F2 mixed with the fluid F1, also depending on the viscosity characteristics of the fluid F1. 
     The first body  13  is associated with a second body  32  suited to define at least part of the delivery ducts C1, C2 suited to convey the two fluids F1 and F2 towards the mixing chamber  12 , and in particular towards the two diffuser holes  31 ,  131 . According to the example of embodiment shown in the figure, the second body  32  is connected to the first body  13  through a snap connection obtained by means of an annular projection  33  belonging to the first body  13  and housed in a corresponding annular cavity  34  belonging to said second body  13 . 
     In a variant embodiment of the invention, the first body  13  and the second body  32  can be connected through equivalent connection means, however suited to allow them to be mutually engaged and disengaged. 
     The first delivery duct C1 of the first fluid F1, that is, the duct C1 that conveys the fluid drawn from the bottom of the container C, preferably comprises a first cylindrical portion  35  of the second body  32  that substantially develops along a main axis X. At least one section  36  of said first cylindrical portion  35  defines a housing seat  37  for a thin tube  38  suited to draw the first fluid F1. The lower end portion  39  of the thin tube  38  is therefore accommodated inside said housing seat  37 . 
     The end portion  39  of the thin tube  38  is preferably engaged in said housing seat  37  through mechanical interference. 
     Also the end portion  39  of the thin tube develops substantially along said main axis X. The first delivery duct C1 also comprises a second portion  45  suited to convey the fluid from the first cylindrical portion  35  until it comes in proximity to the diffuser hole  131 . 
     Inside the first delivery duct C1, and preferably at the level of the first cylindrical portion  35 , there are valve means  41  suited to allow the first fluid F1 to flow towards the mixing chamber  12  and suited to block its flow in the opposite direction, thus making it possible to keep the fluid F1 inside the thin tube  38 . The valve means  41  preferably comprise a ball  42  suited to be arranged in an open and/or closed position with respect to a circular opening  43  present in said first cylindrical portion  35 . 
     The second delivery duct C2 of the second fluid F2, that is, air, preferably comprises two delivery portions defined by facing surfaces  54   a ,  55   a ,  54   b ,  55   b  respectively belonging to said first body  13  and to said second body  32 . 
     The two delivery portions of the second delivery duct C2 allow the second fluid F2 to flow from the inside of the container C to the second diffuser hole  131 . The first delivery portion communicates with the inside of the container C and the second delivery portion, positioned coaxially inside the first one, connects the first delivery portion to the second diffuser hole  131 . 
     A space suited to allow the passage of the fluid F2 is advantageously defined between the facing surfaces  54   a ,  55   a ,  54   b ,  55   b.    
     Preferably, more spaces suited to allow the passage of the fluid F2 (air) are defined between the two facing surfaces  54   a ,  55   a ,  54   b ,  55   b , said spaces being preferably arranged so that they are equally spaced angularly for more homogeneous delivery of the fluid F2 towards the second diffuser hole  131 . 
     During operation, when the container C is pressed by the user the first fluid F1 is drawn by the thin tube  38  and directed along the first delivery duct C1 so that it reaches the mixing chamber  12 . 
     In particular, the first fluid F1 is conveyed and thrust into the end portion  39  of the thin tube  38  towards the mixing chamber  12  substantially along an advance direction D1. Said advance direction D1 is substantially parallel to the main axis X. 
     At the same time the air F2 is directed along the second delivery duct C2 so that it reaches the mixing chamber  12 , too. 
     The foam S that is then dispensed towards the outside through the spout  21  is formed in the mixing chamber  12 , in particular in the filtering element  30 . 
     When the container C is released, the first fluid F1 is sucked back along the thin tube  38  (vacuum effect). The valve means  41 , however, intervene through the ball  42  that comes to be positioned on the circular opening  43  so as to close it. Consequently, the first fluid F1 is not completely sucked into the container C but is maintained within the thin tube  38 . 
     Said fluid F1 inside the thin tube  38  will therefore be immediately ready for the successive dispensing step performed by the user, who will not need to press the container several times to draw the first fluid F1 from the bottom of the container C before the foam S is dispensed. 
     The dispensing device  210 , as in the previous embodiments, is also provided with second valve means  51  suited to recover the air and activated while the container C is being released. Said valve means  51  make it possible to recover and restore the portion of air that was ejected from the inside of the container C during the dispensing operation. Said valve means  51  comprise a ball  52  housed in a chamber provided with a hole  53  that communicates with the outside. When the foam S is dispensed the ball  52  closes the communication hole  53  while when the container C is released the ball  52  clears the communication hole  53 , allowing the air to be sucked and to return into the container C. 
     According to the present invention, the advance direction D1 of the first fluid F1 inside the end portion  39  of the thin tube  38 , substantially parallel to the main axis X, intersects the mixing chamber  12 . In other words, the main axis X, around which the housing seat  37  of the thin tube  38  develops, intersects the mixing chamber  12 . 
     The end portion  39  of the thin tube  38 , the housing seat  37  of the thin tube  38  and the mixing chamber  12  are therefore substantially aligned and coaxial with respect to the main axis X. Furthermore, the housing seat  37  of the thin tube  38  is defined centrally with respect to the second body  32 . 
     Advantageously, the mixing chamber  12  is reached and filled by the fluids F1, F2 in a uniform manner, and not in a dishomogeneous manner, as is the case with the devices of the known type. 
     This makes it possible to improve the mixing of the two fluids F1, F2 inside the mixing chamber  12 . 
     Furthermore, the particular geometric configuration makes it possible to reduce the flow resistance of the fluids F1, F2 to a minimum while the container C is being pressed. 
     Still advantageously, the central position of the housing seat  37  allows the thin tube  38  to be comfortably assembled on the second body  32 . In fact, it will be sufficient to centre the end portion  39  of the thin tube  38  with respect to the second body  32 , with no need to worry about the rotation of the second body  32  itself. This speeds up the assembly steps of the thin tube  38 , in case of both manual and automatic assembly. 
     Furthermore, the presence of a delivery duct for the fluid F2, in particular for the air, defined by facing surfaces of the first and the second body, advantageously makes it possible to adjust cross section through which the fluid F2 flows. 
     A variant embodiment of the dispensing system of the invention, according to which operation takes place with the container C in overturned position, is described with reference to  FIGS. 10 and 11 , analogously to that which happens for the embodiment illustrated in Figures from  5  to  7 . 
     In this case, as already explained above, the first duct C1 serves as delivery duct for the air F1 and the second duct C2 serves as delivery duct for the fluid F2. 
     The dispensing device  310  of the invention comprises a first body  13 , provided with coupling means  13   a  for coupling to the container C. Said coupling means  13   a  preferably comprise a threaded portion suited to be engaged with a corresponding threaded portion present on the neck of the container C. 
     In variant embodiments, said coupling means may be of a different type, for example snap coupling means. 
     On the underside of the first body  13  there is a closing element  14  preferably ending with a spout  21  where the outlet duct  20  for the foam S is provided. According to the example of embodiment shown in the figure, the closing element  14  is connected to the first body  13  through a snap connection obtained by means of an annular projection  17  belonging to the closing element  14  and housed in a corresponding annular cavity  18  belonging to said first body  13 . 
     According to a variant embodiment of the invention, the first body  13  and the closing element  14  may be connected through different connection means or obtained in a single piece, for example through a thermoplastic moulding process. 
     The fluid mixing chamber  12  is defined in the central area of the first body  13 . The mixing chamber  12  comprises a first mixing area  25  suited to receive the first fluid F1 through a first inlet  26  and the second fluid F2 through a second inlet  27 . 
     The first mixing area  25  preferably has the shape of a truncated cone on whose bottom walls said inlets  26 ,  27  for the fluids F1, F2 to be mixed are obtained. 
     The mixing chamber  12  also comprises a second mixing area  28  communicating with the first mixing area  25 . The second mixing area  28  has a substantially cylindrical shape and houses a diffuser element  29  and a filtering element  30 . 
     The diffuser element  29  comprises at its centre a diffuser hole  31  suited to receive the mixture from the first mixing area  25  and to convey it towards the filtering element  30 . 
     The filtering element  30 , substantially the same as the one shown in  FIG. 3A , has a substantially cylindrical shape and has a centre area provided with suitable micro holes that allow the formation of the foam S comprising micro air bubbles F1 mixed with the fluid F2, also depending on the viscosity characteristics of the fluid F2. 
     The first body  13  is associated with a second body  32  suited to define at least part of the delivery ducts C1, C2 suited to convey the two fluids F1 and F2 towards the mixing chamber  12 . 
     According to the example of embodiment shown in the figure, the second body  32  is connected to the first body  13  through a snap connection obtained by means of an annular projection  33  belonging to the first body  13  and housed in a corresponding annular cavity  34  belonging to said second body  32 . 
     In variant embodiment of the invention, the first body  13  and the second body  32  can be connected through equivalent connection means, however suited to allow them to be mutually engaged and disengaged. 
     The first delivery duct C1 of the first fluid F1, that is, air, preferably comprises a first cylindrical portion  35  of the second body  32  that substantially develops along a main axis X. At least one section  36  of said first cylindrical portion  35  defines a housing seat  37  for a thin tube  38  suited to draw the first fluid F1. The lower end portion  39  of the thin tube  38  is therefore accommodated inside said housing seat  37 . 
     Preferably, the end portion  39  of the thin tube  38  is engaged in said housing seat  37  through mechanical interference. 
     Also the end portion  39  of the thin tube develops substantially along said main axis X. The first delivery duct C1 also comprises a second portion  45  suited to convey the fluid from the first cylindrical portion  35  until it comes in proximity to the first inlet  26  of the first mixing area  25 . 
     Inside the first delivery duct C1, and preferably at the level of the first cylindrical portion  35 , there are valve means  41  suited to allow the first fluid F1 (air) to flow towards the mixing chamber  12  and suited to block any flow of the second fluid F2 coming from the diffuser hole  31  in the opposite direction inside the thin tube  38  during the release step. 
     The valve means  41  preferably comprise a ball  42  suited to be arranged in an open and/or closed position with respect to a circular opening  43  present in said first cylindrical portion  35 . 
     The second delivery duct C2 of the second fluid F2 preferably comprises a portion defined by facing surfaces  54 ,  55  respectively belonging to said first body  13  and to said second body  32 . A space suited to allow the passage of the fluid F2 is advantageously defined between the two facing surfaces  54 ,  55 . 
     Said portion of the second delivery duct C2 allows the second fluid F2 to flow from the inside of the container C to the second inlet  27  of the first mixing area  25 . 
     During operation, when the container C is pressed, the first fluid F1 and the second fluid F2 are subjected to pressure and conveyed towards the first mixing area  25  through the respective delivery ducts C1, C2. 
     When the container C is pressed, the first fluid F1 (air) gets into the thin tube  38  and is directed along the first delivery duct C1 so that it reaches the first mixing area  25 . 
     In particular, the first fluid F1 is conveyed and thrust inside the end portion  39  of the thin tube  38  towards the first mixing area  25  substantially along an advance direction D1. Said advance direction D1 is substantially parallel to the main axis X. 
     At the same time, the liquid F2 is directed along the second delivery duct C2 so that it reaches the first mixing area  25 , too. The foam S, which is successively dispensed towards the outside through the spout  21 , is formed in the mixing chamber  12 , in particular in the filtering element  30 . 
     The dispensing device  310 , analogously to the embodiments described above, is furthermore provided with second valve means  51  suited to recover the air and activated while the container C is being released. Said valve means  51  make it possible to recover the air portion that was ejected from the inside of the container C during the dispensing operation. Said valve means  51  comprise a ball  52  housed in a chamber provided with a hole  53  that communicates with the outside. When the foam S is dispensed, the ball  52  closes the communication hole  53  while when the container C is released the ball  52  clears the communication hole  53 , allowing the air to be sucked and to return inside the container C. 
     According to the present invention, the advance direction D1 of the first fluid F1 inside the end portion  39  of the thin tube  38 , substantially parallel to the main axis X, intersects the mixing chamber  12 . In other words, the main axis X, around which the housing seat  37  of the thin tube  38  develops, intersects the mixing chamber  12 . 
     The end portion  39  of the thin tube  38 , the housing seat  37  of the thin tube  38  and the mixing chamber  12  are therefore substantially aligned and coaxial with respect to the main axis X. Furthermore, the housing seat  37  of the thin tube  38  is defined centrally with respect to the second body  32 . 
     Advantageously, the mixing chamber  12  is reached and filled by the fluids F1, F2 in a uniform manner and not in a dishomogeneous manner, as is the case with the devices of the known type. 
     This makes it possible to improve the mixing of the two fluids F1, F2 inside the mixing chamber  12 . 
     Furthermore, the special geometric configuration makes it possible to reduce the flow resistance of the fluids F1, F2 to a minimum while the container C is pressed. 
     Still advantageously, the central position of the housing seat  37  allows the thin tube  38  to be comfortably assembled on the second body  32 . In fact, it is sufficient to centre the end portion  39  of the thin tube  38  with respect to the second body  32 , with no need to worry about the rotation of the second body  32 . This speeds up the assembly steps of the thin tube  38 , in the case of both manual and automatic assembly. 
     Furthermore, the presence of a fluid delivery duct, in particular for the liquid F2, defined by facing surfaces of the first and second body, advantageously makes it possible to adjust the cross section through which the fluid F2 flows. 
     According to the present invention, the presence of different properly interconnected elements makes it possible to produce the same as modules and thus to reduce their productions costs. 
     In particular, the presence of a first and a second body that can be easily interconnected, as well as the possibility to connect the closing element and the thin tube to them, makes it possible to obtain elements that can be used in different manners and according to the desired configuration of the dispensing system. 
     Thus, for example, a comparison between  FIGS. 2 and 3  and  FIGS. 10 and 11  clearly shows that, maintaining the same first body  13  and the same thin tube  38 , it is possible to obtain a dispensing system that works either in the upright or in the overturned position by using a different second body  32  and preferably but not necessarily a different closing element  14 . In other words, it is possible to transform a dispensing device that works in the upright position into a dispensing system that works in the overturned position by simply changing the second body  32 , and if necessary the closing element  14 . Vice versa, it is possible to transform a dispensing device that works in the overturned position into a dispensing system that works in the upright position by simply changing the second body  32 , and if necessary the closing element  14 . 
     Analogously, a comparison between  FIGS. 6 and 7  and  FIGS. 8 and 9  clearly shows that, maintaining the same first body  13  and the same thin tube  38 , it is possible to obtain a dispensing system that works either in the overturned position or in the upright position by using a different second body  32 , and preferably but not necessarily a different closing element  14 . In other words, it is possible to transform a dispensing device that works in the overturned position into a dispensing system that works in the upright position by simply changing the second body  32 , and if necessary the closing element  14 . Vice versa, it is possible to transform a dispensing device that works in the upright position into a dispensing system that works in the overturned position by simply changing the second body  32 , and if necessary the closing element  14 . 
     In this way, advantageously, the dispensing device of the invention makes it possible to reduce production costs compared to the devices of the known type. Furthermore, the presence of several elements that can be interconnected and replaced quickly makes it possible to use different geometric configurations for those elements, which allow the flows of the two fluids inside the respective ducts to be modified. In this way, the percentage of the two fluids inside the same mixture can be regulated as desired, which makes it possible to obtain thicker or thinner foams depending on the expected use. 
     This can be advantageously and comfortably achieved by replacing either the first body  13  or the second body  32 , preferably the second body  32 , while the other can remain the same. By replacing just one element, therefore, it is possible to modify the density of the foam to be obtained as desired. 
     This also makes it possible to reduce the number of elements to be produced for the different types of foam to be obtained, thus reducing the overall production costs compared to the devices of the known type. 
     The above applies to all the embodiments of the invention described above. 
     In the embodiments of the present invention previously described, the shape of the thin tube and of its housing seat in the second body is cylindrical, wherein said cylindrical shape extends along said main axis X. 
     However, in different construction variants said parts may have a different shape, provided that it is suited to define an advance direction of the fluid and that it ensures the characteristics and the advantages described in the present invention. 
     It has thus been shown that the present invention allows the set objects to be achieved. In particular, it makes it possible to provide a fluid dispensing device that allows production costs to be reduced compared to the devices of the known type. 
     If on the one hand the present invention has been described making reference to the specific embodiments illustrated in the figures, it should be noted on the other hand that the present invention is not limited to the specific embodiments illustrated and described herein; on the contrary, further variants of the embodiments described herein fall within the scope of the present invention which is defined in the following claims.