Foam-dispensing device without a propellant gas

(42) Date of commencement of the patent: 15. 7.1991 (45) Date of issue: 27. 1. 1992

<td>(56) Documents:</td><td>(73) Patent owner:</td>

<td>CH-PS 545232 DE-0S2704394 US-PS 4156505 US-PS 4432496</td><td>HENKEL AUSTRIA SOCIETY MBH A-1030 VIENNA (AT).</td>

<td></td><td>(72) Inventor:</td>

<td></td><td>ROSENBERG WERNER ING. VIENNA (AT).</td>

(54) Propellantless Foam Dispenser (57) The invention relates to a foam dispenser, consisting of a container containing liquid and air with a flexible outer wall, whose container opening is equipped with a foam discharge nozzle, and a foam generator inserted in the holder opening, which consists of an insert having a peripheral wall part and a bottom part, in which a porous element covering the entrance opening of the foam discharge nozzle is arranged, and whose bottom part has liquid passage openings and an air passage opening, to which an up to near the tank bottom extending air line is connected. According to the invention it is provided that between the bottom part (8a ') and porous element (10'), a mixing chamber (16 ') is provided, and the porous element (10') one within the insert. (8 ') with circumferential clearance axially displaceable sieve disk which assumes a first end position in contact with a circumference surrounding the inlet opening peripheral flange (23) and underpressure in the container a second end position, in which the outside penetrating air between the sieve disk (10 *) and peripheral wall part (8b ') through to the mixing chamber (16') and through the air passage opening and air line can flow into the container.

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The invention relates to a propellant-free foam delivery device, consisting of a container containing a foam-forming liquid as well as air and having a flexible outer wall, like a handbottle bottle, with a base preferably designed as a base and one at the upper end of the container, container opening equipped with a foam dispensing nozzle, and from a foam generator inserted into the container opening, by means of which in overhead use position of the container, d. H. at below the liquid level in the container lying foam generator, by squeezing the container foam is discharged from the container, the foam generator consisting of a peripheral wall part inserted into the container opening and an insert having a bottom part connected to the latter, in which a porous element covering the inlet opening of the foam dispensing nozzle is arranged, and whose bottom part has passage openings for the passage of liquid and an air passage opening, to which a pipe-shaped air duct extending into the container interior is connected until it is in the immediate vicinity of the container bottom.

In the known foam dispenser of this type (US Pat. No. 3,422,993, FIG. 3 to 5), as it is useful, for example, for the delivery of detergents, polishes and cosmetic products in the form of foams, the use as a porous element contains a sponge-like material that completely fills the insert. If the container is compressed by hand in its overhead use position, in which the tubular air duct extends into the air space present in the container, by the liquid passage openings in use liquid and at the same time through the tubular conduit or the air passage opening of the insert air is pressed into the sponge-like material, whereby in the latter the liquid and the air mix and form a foam, leaving the device through the foam dispensing nozzle If the pressure on the container is lifted, When returning the container to its original shape, it causes a so-called inhalation of the container. wherein the air entering through the foam discharge nozzle from the outside must first pass through the sponge-like material, to then pass through the air passage opening of the insert and the air line into the container interior. The disadvantage here is that this inhalation of the container, since the air must penetrate the sponge-like material, is extremely slow, so the user is put on a hard Patience sample before any further foam delivery. Another disadvantage of the known device is that the air passing through the sponge-like material during this inhalation mixes with the liquid still present in it, so that very soon the air space present in the container is filled up with foam and proper fluffing is no longer ensured , This effect is exacerbated by the fact that, since the liquid passage openings present in use have relatively large cross-section, also a certain amount of air enters through these Flüssigkeitssigkeitsdurchtrittsöffnungen and the liquid column passes in the container, whereby additional foaming takes place in the latter.

The object of the invention is to overcome these disadvantages of the prior art and to provide a foam dispensing device in which upon inhalation of the container entering through the foam discharge nozzle air does not penetrate the porous element and can flow without obstruction in the air space of the container.

This object is achieved on the basis of a foam dispenser of the type described above according to the invention, that, as is well known a space forming a mixing chamber is provided between the bottom part of the insert and the porous element formed in a manner known per se as a sieve disk, and that the screen disc is axially displaceable in this space with circumferential play with respect to the peripheral wall part, being pressed into a first end position in contact with a peripheral flange surrounding the inlet opening of the foam dispensing nozzle and being pressed away from the peripheral flange into a second end position determined by at least one stop when the pressure prevailing in the container is high, in which the air entering the foam discharge nozzle from the outside between the screen disk and the peripheral wall portion of the insert can flow directly to the mixing chamber and through the air passage opening of the bottom part of the insert and the air line into the container.

Although a porous element formed as a kind of screen disk and a space forming a mixing chamber between this screen disk and the bottom part of an insert are already known from CH-PS 545 232, however, the foam delivery device described therein is a foam delivery device intended to deliver foam in the upright position of the container, in which the air passage between the container interior and the mixing chamber does not take place through an air passage opening in the bottom part of the insert but through a plurality of air passage openings in the peripheral wall part thereof and which is connected to an opening in the bottom part of the insert and extending to near the container bottom line is not an air line but a liquid line, so that there are fundamental differences in function over the subject invention.

In the event that the inventively provided screen plate is not made of rigid material, such. B. in the case of a screen disc of nylon or other similar fabric, if not kept may be expressed by the foam discharge nozzle in the container due to the foam release, according to a further feature of the invention, the foam generator arranged between the screen plate and the bottom part of the insert, slidably guided in the axial direction of the screen plate guided piston with a perpendicular to the piston axis extending annular flange, which latter presses the sieve disk in its peripheral region against the peripheral flange surrounding the inlet opening of the foam dispensing nozzle when the container is under pressure.

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Appropriately, this piston is guided in a mixing chamber side provided in the bottom part of the insert annular groove, run from the bottom of several openings through the bottom part to the container interior, wherein the air passage opening and the liquid passage openings of the bottom part open the mixing chamber side within the annular groove. As a result, the piston is acted upon by the interior of the container in each case by the pressure prevailing in the container overpressure or vacuum

Starting from the known arrangement with centrally located in the bottom part of the insert air passage opening and liquid liquid passage openings arranged around the invention proposes according to a further feature that the liquid passage openings merge chamber side in the immediate vicinity of the air passage opening and preferably in this transient. As a result, an intimate mixing of the air and liquid is already achieved when entering the mixing chamber, so that a consistent foam consistency is ensured.

The stop determining the second end position of the screen disk can advantageously be formed by a mixing chamber side provided central projection of the bottom part of the insert, which projection has lateral openings which are in communication with the air passage opening.

In the case of several stops limiting the second end position of the screen disk, these can also be formed by preferably circumferentially uniformly distributed projections of the peripheral wall part or of the bottom part of the insert.

In the preferred embodiment of the invention, the use of the foam generator expediently consists of two, preferably by means of a snap connection, interconnected components, one of which essentially represents the bottom part of the insert and the other the peripheral wall part of the insert, the circumferential flange surrounding the inlet opening of the foam dispensing nozzle as well as the foam dispensing nozzle itself forms

It is also expedient if according to a further feature of the invention, the inlet opening of the foam discharge nozzle tapers conically and preferably has a cone angle of about 60 °. Thus, on the one hand, the effective cross-section of the screen disc is increased and, on the other hand, a type of nozzle injector is formed, which increases the exit velocity of the foam, so that the foam can be discharged deliberately over a certain distance even when the foam discharge nozzle is not directed vertically downwards.

In the case where it is necessary to discharge the foam approximately horizontally or even upwards, such. As in a so-called toilet cleaner, to be deposited with the detergent behind the downwardly projecting inner edge of a toilet bowl, the axis of the foam generator and the Schaumabgabedüse can be arranged obliquely to the container bottom. This can be achieved in a simple manner by an appropriate inclination of the container opening to the container axis.

In this case, the container may be formed flat and narrow in its longitudinal extension in the same sense extending narrow sides of the container wall, the axis of the foam generator and the Schaumabgabedüse is directed against the side determined by the concave narrow side of the container wall side and the free end of the air line to is guided close to this concave narrow side of the container wall. The stronger the curvature of the narrow sides of the container and the inclination of the axis of the foam generator and the foam dispensing nozzle, the steeper the top, the foam discharge can take place.

Finally, it is still advantageous if the nozzle outlet of the foam discharge nozzle bounding free nozzle edge, preferably at an angle of about 45 °, is chamfered. This ensures that the emerging from the Schaumabgabedüse foam tearing off easily from the Schaumabgabedüse at the end of the foam delivery and does not adhere to an undesirable part of it.

The invention will be explained in more detail with reference to embodiments shown in the accompanying drawings. In the drawings: 1 schematically a erfmdungsgemäße foam dispenser in the form of a so-called toilet cleaner, Fig. 2 on an enlarged scale an axial section through a first embodiment of the foam generator of the device according to the invention in the phase of the foam discharge with vertically downwardly directed foam discharge nozzle, Fig. 3 a section analogous to FIG. 2, but in the inhalation phase, Figs. 4,5 and 6, the bottom part of the insert-forming component of FIGS. 2 and 3 in view from below, in axial section or in top view, Fig. 7 an axial section of the peripheral wall part of the insert, the peripheral flange bounding the nozzle inlet opening and the component forming the foam discharge nozzle from FIGS. 2 and 3, Fig. 8th an axial section of the piston of FIGS. 2 and 3, and FIG. 9 a the Figs. 2 and Figure 3 is a similar view of a second embodiment of the foam generator of the foam dispenser according to the invention.

The in Fig. 1 consists of a flat container (1) made of flexible material, in particular plastic, which initially contains about 75% foam-forming liquid (2), in the present case a toilet detergent solution, and about 25% air The container opening is a foam generator (4 ) and a Schaumabgabedüse (5) assigned. A screw cap (6) closes the container. The illustrated foam dispenser is designed to deliver foam in the overhead position of the container (1), i. H. in a position of the container in which the foam generator (4) is located below the liquid level in the container. In the present case, it should be possible to direct the foam obliquely upward in order to deposit it behind the downwardly projecting inner edge of a toilet bowl can. In order to allow such a foam discharge obliquely upward, the narrow sides of the container are curved to one side curved and the axis of the foam generator (4) and the Schaumabgabedüse (5) to the one

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Standing surface forming container bottom (la) arranged obliquely. With (7) from the foam generator (4) leading into the container interior air line is designated, the free end is led to close to the compound of the bottom (la) with the concave narrow side of the container wall and thus in the (overhead) position of use of the container (1) always protrudes into the existing in the container airspace (3).

In the in Figs. 2 to 8 illustrated embodiment, the foam generator (4) consists of an insert (8), a displaceably mounted piston (9) and a screen disc (10). The insert (8) is composed of two components (8a and 8b), which are detachably connected to each other by a Schnappvabindung (11) and of which one (8a) represents a bottom part of the insert (8), while the other (8b ) has a peripheral wall part (12) of the insert, with which the latter is inserted into the container opening (13), and a subsequent to the peripheral wall part (12), the foam discharge nozzle (5) forming part.

As particularly shown in FIGS. 4 to 6 it can be seen the component (8a) forming the bottom part of the insert has a central air passage opening (14), to which the air line (7) leading into the container interior is connected and which on the side of the bottom part facing the foam dispensing nozzle (5) consists of a central projection (15), which is provided with four radial incisions (15a), opens both end face and radially in a between the bottom part (8a) and the screen disc (10) lying mixed gamma (16). The wall of the air passage opening (14) is provided with longitudinal ribs (17), between which the air line (7) is received. In this way, between the ribs (17), the air duct (7) and the wall of the air passage opening (14) passage openings (18) for the liquid to be dispensed (2) formed behind the end of the air duct (at (19), Fig , 2 and 5) pass into the air passage opening (14) before it opens out on the mixing chamber side.

Finally, in the bottom part of the insert forming component (8a) an annular groove (20) is provided on the mixing chamber side, which serves to guide the piston (9) and four of which cause four circumferentially distributed openings (21) through the bottom part to the container interior , The piston (9) consists of a cylindrical tube section (9a) and an annular flange (9b) extending radially therefrom (FIG. 8) whose diameter is smaller than the inner wall of the circumferential wall part (12).

The screen disc (10) consists of a thin nylon fabric and also has a smaller diameter than the inner wall of the peripheral wall part (12).

Now, the operation of the embodiment just described will be explained. If the wall of the container (1) is compressed by hand at the broad sides, an overpressure arises in the interior of the container, so that the air line (7) communicating with the air space (3) of the container and the air passage opening (14) in the bottom part the use of air and through the liquid passage openings (18) in the bottom part liquid from the container into the mixing chamber (16) passes. At the same time enters through the openings (21) liquid in the annular groove (20) of the bottom part, whereby the piston (9) together with the screen disc (10), on which also the liquid / air mixture in the mixing chamber (16) acts in Direction of the foam dispensing nozzle (5) is pressed. In this case, the sieve disk (10) comes into abutment in its edge region on a radial peripheral flange (23) surrounding the nozzle inlet opening (22) and is pressed firmly against the annular flange (9b) of the piston (9) and held thereby. Such retention of the screen disc is necessary because the nylon screen forming the screen disc does not have sufficient inherent rigidity to withstand the pressure of the fluid / air mixture, and thus could cause expulsion of the screen disc by the foam dispensing nozzle. Continued pressure on the container wall pushes the liquid / air mixture through the screen disc (10) and exits as foam through the foam dispensing nozzle (5).

When the pressure on the container (1) is released, when it returns to its original shape in the interior of the container, a suppression occurs, through which the piston (9) and the sieve disc (10) move into the position shown in FIG. 3 get to the position shown in which the screen disc is in contact with the central projection (15) of the bottom part and the piston (9) with its annular flange (9b) in contact with the bottom part (8a), so that the air entering through the foam dispensing nozzle (5) passes at least substantially between the screen disc (10) and the peripheral wall portion (12) of the insert (8) and through the lateral openings formed by the notches (15a) of the projection (15) of the base portion of the projection into the air passage opening (14) and from there through the air line (7) into the air space (3) of the container (1) flows This inhalation of the container is thus very quickly and practically without foaming in the container in front of him. Once the container has reached its original shape, a new foam release can take place.

As can be seen in FIGS. 2, 3 and 7, the foam dispensing nozzle (5) is provided with a conically tapering nozzle inlet (22). Thus, already the effective screen area of ​​the screen plate (10) is increased and on the other hand formed a kind of nozzle injector, which increases the exit velocity of the foam, whereby the foam even with not vertically downwardly facing nozzle, z. B. horizontally disposed nozzle, can be discharged directed over a certain distance away.

In practice, a cone angle of the nozzle inlet (22) of about 60 ° has proven to be particularly favorable.

With the illustrated embodiment, it is possible to selectively convey the foam in the horizontal direction over a distance of 20 to 25 cm.

It is expedient if, as shown, the free edge (24) delimiting the nozzle outlet

Foam dispensing nozzle, preferably at an angle of approximately 45 °, is chamfered. As a result, when the glass is relieved of pressure on the container (1), the foam easily tears off the foam dispensing nozzle (5).

The cross section and the length of the cylindrical part of the foam dispensing nozzle (5) determine the final exit velocity of the foam. Over the cross section of the liquid passage openings (18), the foam consistency is controlled taking into account the viscosity and the foam behavior of the liquid. The cross section of the air passage opening (14) of the bottom part in conjunction with the cross section of the air duct (7) determines the air outlet speed into the mixing chamber (16) and thus the amount of foam produced and the force required for the foam production.

It is expedient if, as in the present case, the liquid passage openings (18) pass into the air passage opening (14), since the thus achieved Injektorwirkung the liquid is mixed with the air before reaching the mixing chamber.

Although this solution is considered to be the most advantageous, such a transition of the liquid passage openings in the air passage opening is not essential. Care should be taken, however, that the liquid passage openings merge as close to the mixing chamber side as possible to ensure effective mixing within the mixing chamber.

In order to essentially eliminate air ingress through the liquid passage openings when the container is inhaled, it is important to keep the cross section of the individual liquid passage openings as small as possible. If the liquid to be foamed is one which, owing to its viscosity and foaming behavior, has to be supplied in a greater amount than the detergent solution used in the present case, it is therefore more likely to increase the number of fluid passage openings than increase its cross section.

In the in Fig. 1 shown type of container (1), it is important in terms of rational assembly that when inserting the equipped with the air line (7) foam generator (4) in the container, the free end of the air line automatically reaches the correct end position in the container. For this purpose, it is provided that the container bottom (la) üa a correspondingly curved connector section gradually merges into the container wall and has a sliding of the line end in the correct end position ensuring education, d. H. free from any obstructions to the sliding of the cable end representing edges od. like. is. Appropriately, therefore, you will move the floor, which is supposed to form a stable base, only with a slight crowning and smooth training or provided with stiffeners in flake form, as shown in FIG. 1 in dashed lines are indicated by way of example.

The two components (8a, 8b) forming the insert (8) and the piston (9) are expediently injection-molded parts made of polyethylene or polypropylene.

The in Fig. 9 illustrated embodiment of the foam generator (4 ') differs from that described above only in that it is at the screen disc (10') to a rigid sieve, ζ. B. made of metal, with which the piston (9), the annular groove (20) and the openings (21) of the embodiment described above can be omitted. Upon compression of the container, the screen disc (10 *) is pressed by the acting on them pressure of the liquid / air mixture in the mixing chamber against the peripheral flange (23), whereas they upon release of the pressure on the container by the then prevailing in the container suppression in abutment with the central projection (15) of the bottom part (8a) is pulled.

It is understood that numerous modifications can be made to the described embodiments without departing from the scope of the invention. For example, instead of a single stop for the screen disc (10,10 ') forming the central projection (15) also several preferably circumferentially uniformly distributed projections on the peripheral wall part or bottom part of the insert (8,8') may be provided for provide a corresponding stroke limitation because screen disc. Furthermore, to with the in Fig. 1 illustrated foam delivery device to allow a foam delivery steep or even vertical upward, the foam discharge nozzle forming pipe part to be correspondingly curved or angled formed. Finally, it could also be provided on the Schaumabgabedüse if necessary attachable flexible conduit to dump the foam in otherwise inaccessible places.