WO2009096777A1

WO2009096777A1 - Method and apparatus for dispensing a product from a container as a spray or foam

Info

Publication number: WO2009096777A1
Application number: PCT/NL2009/000019
Authority: WO
Inventors: Wilhelmus Johannes Joseph Maas; Petrus Lambertus Wilhelmus Hurkmans
Original assignee: Dispensing Technologies B.V.
Priority date: 2008-01-30
Filing date: 2009-01-30
Publication date: 2009-08-06
Also published as: NL1034974A1; NL1034974C2

Abstract

The invention relates to a method for dispensing a product from a container as a spray or foam by introducing a gaseous displacing medium under pressure into the container and mixing some of the displacing medium with the product for dispensing, wherein ambient air brought under pressure by a pump is used as displacing medium. The displacing medium in the container can herein be kept separate from the product by a diaphragm, and only be mixed with the product when this product is dispensed. The invention also relates to an apparatus for performing this method, comprising a container for the product with a dispensing opening, which container is adapted to receive a gaseous displacing medium under pressure, and means for mixing some of the displacing medium with the product for dispensing. This apparatus is provided with a feed opening, through which displacing medium can be introduced into the container. In addition, the container can have a diaphragm for separating the displacing medium and the product, and the mixing means can be arranged in the vicinity of the dispensing opening.

Description

METHOD AND APPARATUS FOR DISPENSING A PRODUCT FROM A CONTAINER AS A SPRAY OR FOAM

The invention relates to a method for dispensing a product from a container as a spray or foam by introducing a gaseous displacing medium under pressure into the container and mixing at least some of the displacing medium with the product for dispensing. Such a method is generally known. In the known method the product is atomized or foamed by a propellant which is received together with the product in the container. Some of this propellant dissolves in the product and comes out of solution again when the product is dispensed, whereby the product is atomized or foamed. This known method of atomizing or foaming has a number of drawbacks .

The propellant must therefore be received initially in the container at a relatively high pressure in order to ensure that there will be sufficient pressure to also allow atomizing or foaming of the final remnants. This makes high demands on the material and the construction of the container. The container is generally of metal and has a relatively heavy construction. As a result of the high pressure the container may only have a small volume in order to limit the risks in the case of an explosion. A relatively large amount of packaging material is therefore necessary per unit of product, and the costs are high. In addition, there are relatively strict requirements for the transport and storage of pressurized containers, thereby increasing costs still further. Finally, due to the direct contact between the propellant and the product for dispensing, the known method is not suitable for every product, among other reasons because the shelf life of the product can be influenced by the propellant.

The invention now has for its object to provide an improved method of atomizing or foaming, wherein the stated drawbacks do not occur, or at least do so to lesser extent. According to a first aspect of the invention, this is achieved in a method as described above in that ambient air brought under pressure by a pump is used as displacing medium. By making use of ambient air as displacing medium the pressure necessary for the atomizing or foaming of the product can be generated in simple manner at the moment the product must be dispensed. It is hereby not necessary to hold the container always under pressure, so that no special requirements apply for storage and transport, whereby logistics are considerably simplified. It is moreover possible in this way to always use precisely the correct pressure for each product. The initial pressure in particular need now not be any higher than is necessary for the atomizing or foaming, so that the container can be given a simpler and lighter construction, for instance in plastic. Due to the lower pressures which occur the container can also have a larger volume.

According to a second aspect, the invention provides a method as described above, wherein the displacing medium in the container is kept separate from the product by a diaphragm, and is only mixed with the product when this product is dispensed. In this way direct contact between the product and the displacing medium is prevented until the moment the product is dispensed, so that the product cannot be affected by the displacing medium. Preferably applied variants of the method according to the invention are described in dependent claims 3-5.

The invention also relates to an apparatus for dispensing a product as a spray or foam, comprising:

- a container for the product with at least one dispensing opening, which container is adapted to receive a gaseous displacing medium under pressure, and

- means for mixing at least some of the displacing medium with the product for dispensing. Such an apparatus is generally known in the form of a spray can.

The known apparatus has the drawbacks discussed above in respect of the method.

The invention has for its object to further develop an apparatus of the above stated type such that the discussed drawbacks do not occur, or at least do so to lesser extent. According to a first aspect of the invention, this can be achieved in such an apparatus by at least one feed opening, through which displacing medium can be introduced into the container. As displacing medium can thus be used ambient air which is brought under pressure by an external pump and can then be pressed through the feed opening into the container.

According to a second aspect, the invention provides an apparatus of the above described type, wherein the container has a diaphragm for separating the displacing medium and the product and the mixing means are arranged in the vicinity of the dispensing opening. This makes it possible to avoid direct contact between the product and the displacing medium until the product is dispensed from the container.

The diaphragm is preferably formed by a flexible inner container which is accommodated in the container and connects to the dispensing opening, and in which the product or the displacing medium is received. A container with such an inner container can be manufactured in simple manner and at low cost. Examples of such containers are described in the non-pre-published Netherlands patent applications 1033582, 1034419 and 1034895 of applicant.

In a preferred embodiment of the apparatus according to the invention the mixing means are adapted to dispense a small quantity of displacing medium separately after and/or before dispensing of the product as spray or foam. In this way the dispensing opening is as it were "blown through" before and after use, thereby preventing product from remaining therein. Such remaining product could dry out, whereby the operation of the apparatus could be affected, or even perish if the product for dispensing is a food product .

A structurally simple apparatus is obtained when the mixing means have a dispensing conduit which leads to the dispensing opening and which is connected to the product by at least one feed opening and to the displacing medium by at least one other feed opening, wherein the feed openings can be closed by respective valves.

In order to simplify the mixing and the number of components, it is recommended that the feed openings for the product and for the displacing medium can be moved by a jointly movable valve.

The above described "blowing through" can be achieved in structurally simple manner when the mixing means comprise a mixing chamber which is arranged between the dispensing conduit and the container and which is closable by the movable valve, wherein the valve is movable between a first, fully closed end position, an intermediate position in which it is only opened for the displacing medium, and a second, fully opened end position. During the movement between the end positions at the start and finish of dispensing of the product the valve then moves in each case to the intermediate position in which only displacing medium can pass through.

In order to prevent unintended escape of product from the container the apparatus is preferably provided with means for biasing the valve to the first, closed end position. In a structurally simple embodiment of the apparatus these biasing means comprise at least one spring formed integrally with the container and engaging on the valve .

In yet another embodiment of the invention which is recommended at the moment, the mixing means comprise a dosing head which is connected movably to the container and in which at least one dispensing conduit for the product and at least one dispensing conduit for the displacing medium is formed, which dispensing conduits are connected to respective openings in the container, wherein the openings can be closed by respective valves. Such a dosing head is easy to manufacture as injection-moulded part. A simple and effective sealing of the container is in this case achieved when the valves are resiliently deformable and can be engaged by end parts of the respective dispensing conduits in order to leave the openings clear.

The valves are preferably biased to their closing position by the pressure in the interior of the container, thus ensuring an optimal sealing under all conditions. In order to prevent product escaping from the container this embodiment of the apparatus can be provided with means for biasing the dosing head to a first position which does not deform the valves. These biasing means can also comprise at least one spring formed integrally with the dosing head and engaging on the container, whereby the number of components, and thereby the number of assembly operations, are limited.

In order to achieve an optimal mixing of the product and the displacing medium it is recommended that the dispensing conduits for the product and for the displacing medium run concentrically.

In another preferred embodiment of the apparatus the mixing means are adapted to mix the displacing medium at a fixed ratio with the product for dispensing. An optimal atomizing or foaming is thus ensured under all conditions. This can be achieved in structurally simple manner when the mixing ratio is determined by the ratio between the flow areas of the respective (feed) openings for the product and the displacing medium. The design of the dispensing conduit (s), mixing chamber and/or dosing head can then be optimized in simple manner for the purpose of atomizing or foaming the product for dispensing.

In order to prevent escape of displacing medium and therefore pressure loss in the container, the apparatus according to the invention is preferably provided with at least one restriction for the displacing medium formed between the interior of the container and the dispensing opening . The apparatus can further be provided with foaming means arranged in the vicinity of the dispensing opening or atomizing means arranged in the vicinity of the dispensing opening.

The invention is now elucidated on the basis of a number of embodiments, wherein reference is made to the accompanying drawing in which corresponding components are designated with reference numerals increased in each case by "100", and in which: Fig. 1 is a longitudinal section through an apparatus according to a first embodiment of the invention,

Fig. 2 is a detail view on enlarged scale according to arrow II in fig. 1, in which the apparatus is shown in the closed rest position,

Fig. 3 shows a view corresponding with fig. 2 of the apparatus during "blowing through" at the beginning of a dispensing cycle,

Fig. 4 is a view corresponding with fig. 2 and 3 of the apparatus during dispensing of the product,

Fig. 5 is a cross-sectional perspective view of an alternative embodiment of the apparatus with foaming means in the dispensing conduit during dispensing of a product,

Fig. 6 is a view corresponding with fig. 5 of the apparatus with atomizing means in the dispensing conduit,

Fig. 7 and 7A show respectively a front view and a cross-section of another embodiment of the apparatus according to the invention which is recommended at the moment, Fig. 8 is a perspective view of an upper part of the apparatus of fig. 7, wherein the cover is removed,

Fig. 9 is a cross-sectional perspective view of the upper part of the apparatus of fig. 8 as seen from a different direction, Fig. 10 is a detail view on enlarged scale according to arrow X in fig. 7A, in which the apparatus is shown in the closed rest position,

Fig. 11 is a view corresponding with fig. 10 which shows an alternative variant of the dosing head, Fig. 12 is a cross-sectional perspective view of a part of the dosing head of fig. 10, and

Fig. 13 is a view corresponding with fig. 12 of the dosing head of fig. 11. An apparatus 1 for dispensing a product P as a spray or foam comprises a container 2 for the product P which is provided with a dispensing opening 3 (fig. 1) . Container 2 is adapted to receive a gaseous displacing medium D under pressure. Formed for this purpose in a bottom 8 of container 2 is a closable feed opening 9 through which displacing medium D can be introduced into container 2. Container 2 can be formed from a plastic such as for instance polyethylene terephthalate (PET) by means of injection-moulding followed by blow moulding. In addition, apparatus 1 comprises means 4 with which some of the displacing medium D can be mixed with the product P for dispensing. These mixing means 4 are arranged in the vicinity of dispensing opening 3. Container 2 has a diaphragm 5 for separating the displacing medium D and the product P, this diaphragm 5 being formed here by a flexible inner container. As container 2 itself, this inner container 5 can be manufactured by an injection moulding process followed by blow moulding. Polypropylene (PP) is for instance suitable as material for inner container 5. In the shown embodiment the product P is received in this inner container 5, which is accommodated in container 2 and connects to dispensing opening 3. Displacing medium D can then be pressed into the space 13 between inner container 5 and the wall of container 2. The reverse situation can however also be envisaged: displacing medium D can be pressed into inner container 5 while product P can then be received in the remaining space 13 inside container 2. Received in inner container 5 is a dip tube 6 which extends from a neck 7 of container 2 to a position close to bottom 8. The product P for dispensing is fed from inner container 5 through this dip tube 6 to mixing means 4. In addition, this dip tube 6 serves to prevent inner container 5 from being pressed together when it is emptied, whereby parts of the product P for dispensing could as it were be "cut off" from dispensing opening 3 and thus be left in container 2.

Mixing means 4 comprise here a mixing chamber 10 which is arranged between dispensing opening 3 and the interior of container 2. Mixing chamber 10 has a first feed opening 11 which is connected via a first conduit 12 to the space 13 left clear by inner container 5, and a second feed opening 14 which is connected to the interior of inner container 5 via a second conduit 15 protruding partially into mixing chamber 10. Feed openings 11, 14 can be closed or left clear by a movable valve 16. This valve 16 is arranged slidably round the end of second conduit 15 and can be moved between a first end position, in which the two feed openings 11, 14 are closed (fig. 2) , and a second end position in which the two feed openings 11, 14 are connected to mixing chamber 10 (fig. 4) . Between these two end positions valve 16 can occupy a position in which first feed opening 11 is left clear while second feed opening 14 remains closed (fig. 3) . In this intermediate position the displacing medium D can flow into mixing chamber 10 and subsequently flow away around the protruding part of second conduit 15 toward a dispensing conduit 17 which debouches in dispensing opening 3.

Valve 16 is biased toward its first, closed end position by biasing means 18. In the shown embodiment these biasing means 18 comprise a flexure spring 19 formed integrally with container 2. Valve 16 can be moved to its second end position by pressing down a control button 20 which is received slidably in a cover 21 placed around neck 7 of container 2. Connected to this control button 20 is a wedge-shaped element 22 which engages on flexure spring 19 and which moves spring 19 further away from second conduit 15 as button 20 is pressed further in. Owing to the decrease in the spring pressure, valve 16 is then pressed away from the second conduit under the influence of the pressure in inner container 5. When control button 20 is released, flexure spring 19 returns to its starting position, whereby valve 16 is moved back to the first, closed end position and control button 20 is pressed upward to its rest position. When valve 16 is in the second, fully opened end position the ratio between the flow areas of the first and second feed openings 11, 14 determines the ratio at which the displacing medium D is mixed with the product P for dispensing. This is a result of the fact that the pressure in inner container 5 is equal to the pressure in the space 13 around inner container 5. Apart from small pressure losses resulting from the design of the first and second conduits 12, 15, the pressure under which the product P and the displacing medium D flow into mixing chamber 10 is therefore the same. The pressure ratio is in any case constant because possible pressure losses are determined by the construction of the apparatus . The mixing ratio is hereby also constant .

The operation of dispensing opening 1 is therefore as follows. Displacing medium D, which is for instance brought under pressure by a pump, is first introduced into the space 13 between inner container 5 and the wall of container 2 via feed opening 9. The product P in inner container 5 is hereby also brought to pressure. Control button 20 is then pressed, whereby wedge-shaped engaging element 22 begins to bend the spring 19 away. Valve 16 hereby begins to move from its first, closed end position in the direction of its second, opened end position. When valve 16 reaches its intermediate position, the first feed opening 11 is left clear so that displacing medium D flows into mixing chamber 10 and flows therefrom along the protruding part of second conduit 15 to dispensing conduit 17 and dispensing opening 3. Dispensing conduit 17 is hereby "blown clean".

When valve 16 subsequently reaches its second, opened end position, product P also flows via second feed opening 14 into mixing chamber 10, where it is mixed with the displacing medium D still flowing in. This is the first and only time that displacing medium D comes into contact with product P. The mixture of product P and displacing medium D then flows through dispensing conduit 17 to dispensing opening 3, where it exits as a spray or a foam. If control button 20 is then released, spring 19 then pushes wedge-shaped engaging element 22 upward and valve 16 to its first, closed end position. Valve 16 here once again passes through its intermediate position, in which second feed opening 14 is already closed while first feed opening 11 still remains clear. In this position only displacing medium D is thus once again dispensed, whereby dispensing conduit 17 is blown clean again before valve 16 completely ends dispensing of product P and displacing medium D. In an alternative embodiment of apparatus 101 mixing means 104 do not comprise a separate mixing chamber for dispensing conduit 117. Instead, product P and displacing medium D flow separately along different paths to dispensing conduit 117, where they are mixed. Mixing means 104 comprise a plug 123 which is received sealingly in neck 107 of container 102 and in which various conduits are situated. Product P flows out of dip tube 106 via a vertical conduit part 124 into a horizontal conduit part 115, in which a first valve 116 is slidably accommodated. This horizontal conduit 115 debouches in dispensing conduit 117 via a feed opening 114. Displacing medium D on the other hand flows via an oblique conduit part 126 through a side wall of plug 123, and from there through a vertical conduit 127 to a partially annular conduit 112. This annular conduit 112, in which a second valve 128 is slidably accommodated, debouches in dispensing conduit 117 via a feed opening 111. This feed opening 111 is relatively small and thus forms a restriction, thereby preventing pressure loss in the container.

Second valve 128 encloses first valve 116 in sealing manner so that they can function as a single valve. Valves 116, 128 can be connected to each other by a pin or screw which can be inserted into central openings 129, 130 of valves 116, 128. By adjusting the relative position of valves 116, 128 the sequence in which they close the respective conduits 112, 115 can be determined. If desired, dispensing conduit 117 can thus be "blown clean" again before and after dispensing of product P.

In this embodiment flexure spring 119 is placed adjacently of conduits 112, 115 and connected via a bridging piece 125 to valves 116, 128. In this embodiment the whole cover 121 is movable relative to neck 107 and thus functions as control button. Formed in cover 121 is an elongate opening 129 through which the end of dispensing conduit 117 protrudes . Dispensing conduit 117 is clamped in a recess 130 in plug 123 and here leaves clear a small gap at the position of feed opening 111 for displacing medium D. Received in dispensing conduit 117 are foaming means 131 in the form of a multi-branch member 132, which disrupts the flow of product P, and a grid 133.

In a variant of this embodiment atomizing means 134 are here received in dispensing conduit 117 instead of foaming means (fig. 6) . These atomizing means comprise an outer tube 135 which is clamped into recess 130 of plug 123 and which has a stepped central bore 136. A likewise stepped hollow body 137 is accommodated with slight clearance in this bore 136, this body being clamped into plug 123 in the vicinity of feed opening 114. Central bore 136 is closed by a spray nozzle 138 which defines dispensing opening 103. An inner tube 139 placed in hollow body 137 debouches in this spray nozzle, whereby product P is dispensed. In addition, spray nozzle 138 is connected to the space between hollow body 137 and outer tube 135, whereby displacing medium D is dispensed. Mixing of product P and the dispensing medium therefore takes place in spray nozzle 138.

In yet another embodiment of apparatus 201 which is recommended at the moment, inner container 205 is not only fixed to container 202 at the position of neck 207, but also at the position of bottom 208 (fig. 7A) . Dip tube 206 then fulfills no function in holding open the inner container 205, and can thus be given a considerably thinner form than in the first embodiment. It would even be possible to omit the dip tube. For details of the fixing of inner container 5 reference is made to the above stated Netherlands patent application 1034419. This figure also shows the electrically driven pump unit 240 with which the displacing medium D is brought to pressure. This pump unit 240 is connected releasably to container 202.

In this embodiment deformable valves 216, 228 are applied instead of the slidable, rigid valves of the previous embodiments. These valves 216, 228 stand vertically and are clamped onto base 241 of an insert 242 received in the neck 207 of container 202. This insert 242 is fixed in the neck by a plug 223, which in turn carries a slidable dosing head 243. This dosing head 243 is provided with a pair of protruding legs 244 which are received slidably in guides 245 in plug 223. Dosing head 243 is further provided with a dispensing conduit 212 for displacing medium D and a dispensing conduit 215 for product P. These conduits 212, 215 are received slidably in respective openings 246, 247 in plug 223. Respective sealing edges 248, 249 are provided here to prevent leakage. Conduits 212, 215 are connected via respective openings 250, 251 to a chamber 252 in dosing head 243 in which chamber a conduit block 253 is arranged. Opening 250 is once again very small and functions as restriction. The other ends of conduits 212, 215 debouch into insert 242 via respective feed openings 211, 214 and are closed by valves 216, 228.

In the shown embodiment valves 216, 228 are to some extent cup-shaped and, as stated, their narrow underside is clamped between respective upright edges 254, 255 on base 241 of insert 242. They each have a side wall flaring toward the top and ending in a wide, slightly dish- shaped sealing edge 256, 257 respectively. These wide edges 256, 257 serve on the one hand to make sealing contact with the edges of openings 246, 247 in plug 223, and on the other to provide an engaging surface for the end edges of dispensing conduits 212, 215 of dosing head 243. Formed in these end edges are respective recesses 258, 259 through which respectively displacing medium D and product P can flow from insert 242 to the respective conduits 212, 215 when valves 216, 228 are deformed by dosing head 243 with conduits 212, 215 being moved downward. In insert 242 a product chamber 262 is separated from a chamber 263 for displacing medium D by walls 260, 261. Product chamber 262 is connected via an opening 264 to dip tube 206 and thereby to inner container 205, while the other chamber 263 is connected to the space 213 around inner chamber 205 because the peripheral wall 265 of insert piece 242 does not extend all the way to plug 223. The same pressure thus prevails in the two chambers 263, 264 of the insert as in container 202. Because this pressure acts on the flaring side surfaces of valves 216, 228, sealing edges 256, 257 are pressed firmly onto the edges of openings 246, 247.

Dosing head 243 is operated by pressing a pivotable centre part of cover 221 which functions as control button. A biasing force generated by four springs 219 formed integrally with dosing head 243 must herein be overcome. The pressure in container 202 which acts on the flaring side surfaces of valves 216, 228 must also be overcome. Only then can product P flow to chamber 252 in dosing head 243 via dip tube 206, chamber 262, recesses 259, conduit 215 and opening 251. Displacing medium D can then also flow to chamber 252 in dosing head 243 over peripheral wall 265, through chamber 263, recesses 258, conduit 212 and opening 250. As stated, a conduit block 253 is arranged in this chamber 252. In the shown example this conduit block 253 has a central, continuous conduit 266 for product P and an annular conduit 267 for displacing medium D formed concentrically therearound and debouching into the periphery of conduit block 253 via a radial conduit 268. Concentric conduits 266, 267 debouch into a spray nozzle 238 by which the conduit block 253 is fixed in chamber 252 and which defines dispensing opening 203. It is thus only in this spray nozzle 238 that displacing medium D is mixed with product P.

In an alternative embodiment of conduit block 269 (fig. 11, 13) the central conduit 270 is intended for the displacing medium D and is connected via a radial conduit 271 to the periphery of conduit block 269. The concentric annular conduit 272 is here however intended for product P and is connected via a bore 273 to the rear surface of conduit block 269. The invention thus makes it possible to dispense a product in the form of a spray of foam without making use therein of a propellant confined in a container. It is thus possible to suffice with a container of relatively light construction which can moreover have a relatively large volume. The invention moreover makes it possible to atomize or foam a product without it having to be in prolonged contact with a gas-forming medium. The product is thus prevented from being affected by the gas-forming medium.

Although the invention has been discussed above on the basis of an embodiment, it will be apparent that it is not limited thereto. The inner container could for instance be fixed to the container not only at the position of the neck, but could be fixed at a number of positions to the peripheral wall of the container by means of welding or an adhesive connection, as described in the above mentioned

Netherlands patent application 1034895. The inner container could even be manufactured integrally with the container as described in the above mentioned Netherlands patent application 1033582, so that it would be connected to the wall of the container along its whole periphery. In this case the first conduit would have to extend over substantially the full height of the container as far as the space between the bottom of the inner container and the bottom of the container.

The mixing means can further be embodied other than shown and described here, while the form and construction of the biasing means can also be varied in many ways. Instead of a vertically movable control button being arranged on the top side of the cover, it could also be arranged on the front side and be horizontally movable.

The scope of the invention is therefore defined solely by the following claims.

Claims

1. Method for dispensing a product from a container as a spray or foam by introducing a gaseous displacing medium under pressure into the container and mixing at least some of the displacing medium with the product for dispensing, characterized in that ambient air brought under pressure by a pump is used as displacing medium.

2. Method as claimed in claim 1 or the preamble thereof, characterized in that the displacing medium in the container is kept separate from the product by a diaphragm, and is only mixed with the product when this product is dispensed.

3. Method as claimed in claim 1 or 2 , characterized in that a small quantity of displacing medium is dispensed separately after and/or before dispensing of the product as spray or foam.

4. Method as claimed in any of the foregoing claims, characterized in that the displacing medium is mixed at a fixed ratio with the product for dispensing.

5. Method as claimed in any of the foregoing claims, characterized in that the displacing medium and the product flow concentrically out of the container.

6. Apparatus for dispensing a product as a spray or foam, comprising: - a container for the product with at least one dispensing opening, which container is adapted to receive a gaseous displacing medium under pressure, and

- means for mixing at least some of the displacing medium with the product for dispensing, characterized by at least one feed opening, through which displacing medium can be introduced into the container.

7. Apparatus as claimed in claim 6 or the preamble thereof, characterized in that the container has a diaphragm for separating the displacing medium and the product, and the mixing means are arranged in the vicinity of the dispensing opening.

8. Apparatus as claimed in claim 7, characterized in that the diaphragm is formed by a flexible inner container which is accommodated in the container and connects to the dispensing opening, and in which the product or the displacing medium is received.

9. Apparatus as claimed in any of the claims 6-8, characterized in that the mixing means are adapted to dispense a small quantity of displacing medium separately after and/or before dispensing of the product as spray or foam.

10. Apparatus as claimed in any of the claims 6-9, characterized in that the mixing means comprise a dispensing conduit which leads to the dispensing opening and which is connected to the product by at least one feed opening and to the displacing medium by at least one other feed opening, wherein the feed openings can be closed by respective valves.

11. Apparatus as claimed in claim 10, characterized in that the feed openings for the product and for the displacing medium can be moved by a jointly movable valve .

12. Apparatus as claimed in claims 9 and 11, characterized in that the mixing means comprise a mixing chamber which is arranged between the dispensing conduit and the container and which is closable by the movable valve, wherein the valve is movable between a first, fully closed end position, an intermediate position in which it is only opened for the displacing medium, and a second, fully opened end position.

13. Apparatus as claimed in claim 12, characterized by means for biasing the valve to the first, closed end position.

14. Apparatus as claimed in claim 13, characterized in that the biasing means comprise at least one spring formed integrally with the container and engaging on the valve .

15. Apparatus as claimed in any of the claims 6-9, characterized in that the mixing means comprise a dosing head which is connected movably to the container and in which at least one dispensing conduit for the product and at least one dispensing conduit for the displacing medium is formed, which dispensing conduits are connected to respective openings in the container, wherein the openings can be closed by respective valves.

16. Apparatus as claimed in claim 15, characterized in that the valves are resiliently deformable and can be engaged by end parts of the respective dispensing conduits in order to leave the openings clear.

17. Apparatus as claimed in claim 16, characterized in that the valves are biased to their closing position by the pressure in the interior of the container.

18. Apparatus as claimed in any of the claims 15- 17, characterized by means for biasing the dosing head to a first position which does not deform the valves.

19. Apparatus as claimed in claim 18, characterized in that the biasing means comprise at least one spring formed integrally with the dosing head and engaging on the container.

20. Apparatus as claimed in any of the claims 15- 19, characterized in that the dispensing conduits for the product and for the displacing medium run concentrically.

21. Apparatus as claimed in any of the claims 6- 20, characterized in that the mixing means are adapted to mix the displacing medium at a fixed ratio with the product for dispensing.

22. Apparatus as claimed in claims 9 or 15 and 21, characterized in that the mixing ratio is determined by the ratio between the flow areas of the respective (feed) openings for the product and the displacing medium.

23. Apparatus as claimed in any of the claims 6-

22, characterized by at least one restriction for the displacing medium formed between the interior of the container and the dispensing opening.

24. Apparatus as claimed in any of the claims 6-

23, characterized by foaming means arranged in the vicinity of the dispensing opening.

25. Apparatus as claimed in any of the claims 6- 23, characterized by atomizing means arranged in the vicinity of the dispensing opening.