CH617632A5 - Foam dispenser - Google Patents

Abstract

The foam dispenser comprises a flexible container (12) containing an emulsible liquid (18) and a certain volume of air, a porous element (14) separating the inside of the container from the dispensing orifice (30), and a pipe (16-20) connecting the inside of the container with the inside of the porous element. Thus, when pressure is applied to the container, the liquid penetrates into the porous element through the pipe and the air penetrates into it directly without passing through the pipe. The two fluids mix in the porous element and form the foam. Because of this arrangement, this dispenser can be used in any position. An orifice (28) controlled by a valve (32) allows the rapid intake of air after expulsion of the foam. This dispenser is suitable for food, cosmetic and maintenance products. <IMAGE>

Description

The present invention aims to provide a manual pressure foam dispenser fulfilling these conditions. This distributor is defined in claim 1.

The advantages of the invention will emerge from the detailed description which follows and from the drawings in which:

fig. 1 is a longitudinal section of a preferred form of the foam dispenser of the present invention;

fig. 2 illustrates the use of the dispenser of FIG. 1 in normal position;

fig. 3 illustrates the use of the dispenser of FIG. 1 in the inverted position;

fig. 4 is a longitudinal section of a variant of the foam dispenser of the present invention;

fig. 5 illustrates the use of the dispenser of FIG. 4 in reverse position.

The drawings, and more particularly FIG. 1 represent a foam dispenser 10 which comprises a flexible container 12, a porous element 14 and a dip tube 16 the end of which is normally immersed in an emulsifiable solution 18. The other end of the dip tube 16 passes through the porous element 14. In the illustrated embodiment, the tube 16 is in two parts 20 and 22 to facilitate assembly, but one could also use a tube in one piece.

The part of the tube 16 which passes through the porous element 14 is pierced with at least one lateral hole 26 opening into the porous element and an axial hole 28 opening into the dispensing spout 30. This part of the tube 16 also contains a valve 24 consisting, in the particular case, of a sub-dimensioned ball 32 and a series of internal projections 34 which retain the ball in the upper end of the tube. The role of the valve 24 is to selectively direct the air and the emulsifiable solution to the holes 26 or 28, depending on the position of the distributor.

The assembly comprising the holes 26 and 28 and the valve 24 in fact constitutes a fluid passage control device sensitive to the position of the distributor and to the action exerted from the outside on the distributor.

The operation of the foam dispenser 10 will be better understood by referring to FIGS. 2 and 3. In fig. 2, the foam dispenser is used in the normal position, that is to say with its spout facing upwards. When the user manually compresses the flexible container, the internal air pressure increases and causes the emulsifiable solution 18 to rise in the dip tube 16, which has the effect of applying the ball 32 against the axial hole 28. The solution 18 is therefore injected into the porous element 14 through the lateral holes 26. Simultaneously, the air which is compressed in the upper part 36 of the container escapes through the porous element 14 in which it mixes with the solution 18 to produce a foam 38 which exits through the dispensing spout 30. As soon as the user releases his pressure on the container, the ball 32 falls back on the projections 34 and allows outside air to enter through the axial hole 28. The valve 24 offering only minimal resistance to the passage of air, the flexible container 12 quickly resumes its original shape.

In fig. 3, the foam dispenser 10 is used upside down, that is to say with its spout 30 directed downwards. In this case, the paths followed by the solution 18 and by the air are different. More particularly, the end of the tube 16 which previously plunged into the solution 18 (see fig. 2) is now in the air and the porous element 14 which was in contact with the air is

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now bathed by the solution 18. When the user presses on the flexible container, it is pressurized air which circulates in the tube 16 and which applies the ball 32 against the periphery of the axial hole 28. This compressed air leaves through the side holes 26 and mixes with the solution 18, which is simultaneously injected into the porous element 14, to produce a foam 38 in the dispensing spout 30. In summary, by turning over the dispenser 10, the circuits are simply exchanged air and solution, both of which end at the porous element 14, and the quality of the foam remains unchanged.

The role of the valve 24 is to close the axial hole of the tube 16 when the container is pressurized in any position, to inject the fluid of the dip tube 16, whether air or solution, by the side holes 26. The valve must also ensure rapid return of the air to allow the flexible container to return to its original shape. Although the ball valve described and illustrated is perfectly suitable for such an application, it is obvious that other types of valves can perform the same functions. The ball valve, however, has the additional advantage of being put automatically by gravity in the closed position of the axial hole 28 when the container is inverted.

The porous element 14 can be of any material offering a very large number of tortuous paths necessary for the intimate mixing of the emulsifiable solution and the air. Although there are flexible porous materials, it is generally preferable to choose one which is more or less rigid to avoid loss of compression in the tortuous channels, which is detrimental to the uniformity of the foam. Among the rigid porous materials, there may be mentioned vitrified volcanic materials, sintered glass of the type used in filter cartridges, or incompressible plastics made porous, such as polyethylene, polypropylene, nylon, rayon, etc.

The porosity and / or the rigidity of the porous element 14 are essential factors for obtaining a good quality foam. More specifically, the points of introduction of the air and of the emulsifiable solution into the porous element 14 depend on the position of the container at the time of pressurization. The porosity of the element 14 must therefore allow the flow of uniform quantities of each of the two constituents to ensure an ideal mixture, whatever the position of the container. In addition, leakage of emulsifiable solution must be avoided when the container is overturned without pressurization. Rigid porous materials are preferable to flexible materials, because they avoid the drawback of compressibility which, by reducing the cross-section of the tortuous passages, slows the flow of liquid more than that of air. It is sometimes desirable to choose the characteristics of the porous element to obtain optimal foam production in a certain position of the dispenser. It is possible, for example, to produce a dispenser operating under the best conditions in the inverted position, that is to say when the emulsifiable solution is injected from the bottom of the porous element.

The dip tube which brings the emulsifiable solution or the air (depending on the position of the dispenser) to the porous element can be made of any material compatible with the solution, and can have any section, round, square or other . It is generally preferable that the dip tube crosses the porous element over its entire height, but the dispenser can also operate in the manner described with a tube whose end is located in the porous element, provided that the distance between the hole in the tube of the upper surface of the porous element and the dispensing spout does not prevent the return of air.

The flexible container can be made of any material capable of containing the emulsifiable solution and the air. Most often, the pressure necessary for the production of foam by the process described above is obtained by compressing the container with the hand. For this, the material used must be sufficiently flexible and elastic, which is the case with many known plastics.

Figs. 4 and 5 illustrate a variant of the foam dispenser of FIGS. 1 to 3 using a flexible bladder to isolate the emulsifiable solution from the air.

The dispenser of fig. 4 comprises a flexible container 110, a porous element 112 and a dip tube 114 which passes longitudinally through the porous element 112 and enters the container 110. A flexible bladder 116 is hermetically fixed around the part of the tube 114 which descends into the container . At its upper end, the tube 114 is pierced with holes 118, 120 and has a valve comprising a ball 124 and internal projections 122 retaining this ball, which acts as a shutter for the axial hole 120, as in the distributor of FIGS. 1 to 3.

Fig. 5 illustrates the use of the dispenser of FIG. 4 in reverse position. In this position, the ball 124 is subjected to the action of gravity and internal pressure to close the axial hole 120. The air 126 which is contained in the bladder 116 is therefore injected into the porous element 112 by the side holes 118. As illustrated in fig. 5, the emulsifiable solution 128 is in direct contact with the porous element 112 and the manual compression of the container 110 also causes the pressurization of the solution which is injected into the porous element where it mixes with the compressed air of the tube 114 to produce a foam 132 which leaves through the dispensing spout 130.

When the pressure of the fingers is partially or totally released on the container 110, the ball 124 moves away from the hole 120 to allow rapid return of the air in the bladder 116. This re-inflation of the container can also be done in position normal than in the inverted position.

The role of the ball 124 is to close the axial hole 120 when the container is pressurized or turned over so that the air contained in the bladder 116 is injected into the porous element 112 through the side holes 118. The valve must also allow rapid re-inflation of the bladder 116 so that the container 110 can resume its original shape. The ball valve described and illustrated is satisfactory in this regard, but it is obvious that other types of valves can be used.

The bladder 116 serves to isolate the emulsion air from the solution 128 in order to avoid fouling of the dip tube with foam formed inside the container. Thus, even if the dispenser is agitated before use, there can be no foam in place of air in the dip tube. This also eliminates the disadvantages of repeated use of the dispenser. In general, the presence of foam in place of air affects the quality and uniformity of the foam produced. The bladder 116 must be flexible enough to inflate and deflate at the rate of use of the dispenser and any material fulfilling this condition can be used, provided that it is compatible with the emulsifiable solution.

It is preferable that the dip tube 114 penetrates a certain length inside the bladder. This is to prevent the liquid that sometimes condenses in the bladder from escaping when the dispenser is used in the inverted position. In this case, this liquid collects outside the tube in the bottom of the bladder which deflates.

One could put the liquid in the bladder, the air filling the rest of the container, in which case the dispenser could operate in both an upright position and an inverted position. The dip tube could also include a passage through the porous element. t

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5 sheets of drawings

Claims (7)

617 632 2 1. Foam dispenser comprising a flexible container (12,110) containing an emulsifiable liquid and a certain volume of air, the container comprising a dispensing orifice (30), characterized by a porous element (14,112) separating an area adjacent to the dispensing orifice inside the container and via a conduit (16-26,114-118) communicating the interior of the container with the interior of the porous element. 2. Foam dispenser according to claim 1, characterized in that a bladder (116) is arranged inside the container to contain one of the fluids and isolate it from the other, the conduit (114-118 ) communicating the bladder with the porous element. 3. Foam dispenser according to one of claims 1 or 2, characterized in that the porous element is practically incompressible. 4. Foam dispenser according to one of claims 1 to 3, characterized in that the conduit at least partially passes through the porous element and communicates transversely with it. 5. Foam dispenser according to claim 1, characterized in that the duct is constituted by an elongated tubular element, the end of which dives near the bottom of the container, and the other end penetrates into the porous element to direct the fluid transversely in the porous element. 6. Foam dispenser according to one of claims 1 to 3, characterized in that the duct has a first opening (26, 118) opening into the porous element and a second opening, for air intake, (28,120) opening into an area adjacent to the dispensing orifice, a valve (32,124) being associated with the second opening for closing it when the container is compressed so that the fluid is directed into the first opening. 7. Foam dispenser according to claim 6, characterized in that the valve comprises a ball housed inside the conduit and support means (34, 122) arranged in the conduit for retaining the ball when the container is in depression while allowing the flow of air around the ball. Current trends in the packaging of products sold to the general public are showing significant demand for new distributors of cleaning products, cosmetics and certain food products. For many of these products, application in the form of foam using a hand-held dispenser is convenient. To dethrone conventional packaging, such a dispenser must however be economical, practical and efficient. Internal pressure distributors or bombs make it possible to obtain instant foam, but in return, require the use of containers which are strong enough to withstand relatively high internal pressures, resulting in a high cost price. In addition, the gas which is used as an emulsion agent and as a propellant is not renewed and the duration of use of the dispenser is therefore necessarily limited. To overcome the drawbacks of rigid foam dispensers with internal pressure, various types of flexible reception foam dispensers actuated by hand pressure have been studied. The main disadvantage of most, if not all, of these devices is that they can only operate in one position, usually vertical. It would therefore be particularly advantageous to have a foam dispenser of this type which can operate in any position. US Patent No. 3422993 describes foam dispensers with flexible containers capable of operating upside down. Although the foam dispensed is apparently of good quality, this quality degrades when the container is shaken before use or simply when it is used several times in succession. In fact, the agitation of the emulsifiable solution produces a foam inside the container, especially in the vicinity of the internal air intake, which disturbs the foam formation process. There is therefore a large potential market for a foam dispenser capable of operating both upside down and in place and providing good quality foam, even after being agitated or after repeated use.