EP0530570A1 - Device for making and dispensing foam - Google Patents

Abstract

Fitted into the neck (14) of a container (16) is a securing part (12), in the central opening (20) of which there is located the mixer part (26) with mixing chambers (38, 40), covered over by a screen-like refining element (48). Arranged on the refining element (48) is a disk-like valve body (58), which interacts with a ring-like valve seat (60). For discharging foam, the actuating element (70) is pressed down, until the stop (78) bears against the counter-stop (78'). As a result, the valve body (58) reaches the open position, with simultaneous bending of the refining element (48), and air is forced through the air passages (32) and liquid is forced through the liquid passage (34) into the mixing chambers (38, 40) by virtue of the positive pressure in the container (16). The foam formed there is refined upon flowing through the refining element (48). On the way to the outlet (92), the defined passage (74), the fins (68, 102), the ribs (72'), the screen (86) as well as chicanes in the annular channel (96) ensure optimum foam formation and retarding of the foam, so that the positive pressure in the container (16) does not drop abruptly when the valve arrangement is opened.

Description

The present invention relates to a device for a container for foamable liquid for generating and dispensing foam, according to the preamble of claim 1.

Aerosol bottles for dispensing a liquid or a foam by spraying with propellant are known. In these aerosol bottles, a mixture of the foamable liquid and liquefied propellant gas is dispensed through an aerosol valve to generate foam, the propellant gas relaxing after leaving the valve and thus causing the liquid to foam. For reasons of environmental protection, there is a need to refrain from using environmentally harmful propellants. For this reason, bottles have already been developed in which the driving pressure is generated by means of air pumps which are integrated in the bottles and represent a type of piston arrangement. The spraying of liquid from such bottles can be done with conventional aerosol valves. On the other hand, the foam delivery from such bottles is extremely problematic, since in such bottles with air pumps or compressed air bottles, the air acting as the propellant gas is not liquefied and therefore does not evaporate (does not relax) when leaving the aerosol valve to cause the liquid to foam up.

Generic devices for generating and dispensing foam, which are provided for compressible bottles are known from CH-A-676 456. In an axial opening of a specific holding part to be arranged on the neck of the bottle, a mixer part is provided which has a mixing chamber arrangement into which air and liquid passages open. In the mixing chamber arrangement, the air and liquid pressed in when the bottle is compressed are mixed, producing coarse foam. The coarse foam is refined in a sieve-like refinement element and passed through a channel arrangement to an outlet. In addition to the axial opening, the holding part has openings for secondary air, which is sucked in by the environment when the compressed bottle deforms back into its original shape. The channel arrangement guiding the foam from the mixer part to the outlet is arranged in a cap which covers the holding part and in which a further channel arrangement is provided for the secondary air. The cap is mounted in a nut-like manner on a thread of the holding part between an open and a closed position. In the closed position, a tubular valve body arranged on the cap engages in a valve seat on the holding part, which is formed at the end of a tube intended for guiding the foam, in order to prevent foam from escaping. By turning the cap into the open position, the valve body releases an annular gap-like passage between itself and the valve seat in order to allow the foam formed to flow out when the bottle is subsequently compressed. A further closure body is provided on the cap in order to prevent secondary air from entering the bottle in the closed position. To produce and dispense foam, this known device first uses the pressureless bottle Twisted the cap from the closed to the open position and then by squeezing the bottle or by pumping air into the bottle, the foam is generated and released. The foam formation is stopped by no longer compressing the bottle or by no longer pumping in air. If foam is no longer required after one or more withdrawals, the cap can be turned back to the closed position in order to close the channel arrangement and the opening for the secondary air. The known device is not intended and not suitable for containers which are put under pressure beforehand when foam is removed by means of pumps or are under constant pressure.

It is therefore an object of the present invention to further develop the generic device in such a way that, with a simple structure, it is suitable for producing and dispensing foam from containers which are constantly under pressure or which are previously pressurized to remove foam, a gas which does not pollute the environment, in particular air, serves as a blowing agent.

This object is achieved by a generic device which has the features of the characterizing part of claim 1.

In order to avoid the rapid escape of the air from the pressurized container and the associated rapid loss of pressure, baffles are provided in the channel arrangement, by means of which the flow rate of the foam is braked. The foam itself is used as a kind of "cone" to prevent the flow of the To reduce compressed air. For the same purpose, limiting means are provided which determine the open position of the valve arrangement in such a way that the annular gap-shaped passage between the valve seat and the valve body is so small that the amount of air flowing out is throttled, but on the other hand is so large that the foam produced is not destroyed .

Further preferred forms of training are specified in the dependent claims.

Fig. 1

einen axialen Schnitt durch eine erfindungsgemässe Vorrichtung; und

Fig. 2 und 3

Querschnitte entlang den Linien II-II und III-III der Figur 1.

The present invention will now be explained in more detail with reference to an embodiment shown in the drawing. It shows purely schematically:

Fig. 1

an axial section through an inventive device; and

2 and 3

Cross sections along the lines II-II and III-III of Figure 1.

The device 10 for producing and dispensing foam has a holding part 12, which is inserted into a neck 14 of a container 16, for example a bottle made of plastic, and is fastened in a pressure-tight manner by means of a union nut 18. In this holding part 12 there is an opening 20 which extends in the axial direction and is essentially axially symmetrical and has two shoulders 22, 22 '. A mixer part 26 is press-fitted into this opening 20 by means of a collar-ring groove snap connection 24. This mixer part 26 in turn has a ribbed inside in the longitudinal direction Opening 28 into which the end of a tube 30 is inserted such that it is held by the apexes of the ribs of the opening 28. Between the outside of the pipe 30 reaching to the bottom of the container 16, which is not shown, and the inside of the opening 28, there is thus a ring of air passages 32 which is coaxial with the continuous liquid passage 34 in the pipe 30.

A mixing chamber arrangement 36 with two mixing chambers 38, 40 connected in series is provided in the mixer part 26. The air and liquid passages 32, 34 open into the first mixing chamber 38, a swirl chamber, and the latter is flow-connected to the second mixing chamber 40 via passages 42 which run in the axial direction and form a cross-sectional constriction and form the end of the opening 28. The passages 42 are arranged in a ring shape around a central displacement body 44, which projects conically against the pipe 30 and ensures good swirling of the supplied liquid and air.

The mixer part 26 has on its end facing away from the tube 30 a stepped recess 46 into which the passages 42 open and which is covered by a sieve-like refinement element 48. This recess 46 forms the second mixing chamber 40, into which a conical support member 50 formed on the displacement body 44 and blunt at its tip projects. The refinement element 48 lies in the center of this support member 50. The refinement element 48 is held on the circumference and for this purpose in one of the front side of the mixer part 26 and the first shoulder 22 of the holding part 12 formed, circumferential clamping gap 52 is clamped. The first shoulder 22 is undercut and into this undercut 54 a circumferential bead 56 protrudes from the end face of the mixer part 26 in the axial direction, so that the refining element 48 bent in the edge area and engaging in the undercut 54 is held firmly. The refining element 48 serves to refine the coarse foam formed in the mixing chambers 38 and 40.

The refinement element 48, which is clamped in on the circumference and supported in the center by the support member 50, is designed to be elastically deformable and on it, on the downstream side facing away from the second mixing chamber 40, lies a disk-like, likewise deformable valve body 58. This valve body 58 interacts with an annular valve seat 60 which is formed on the end face of a tubular wall part 62 of the mounting part 12 on this side. This valve seat 60 forms the second shoulder 22 ', which is also undercut and thus delimits an annular space 64 which surrounds the valve body 58 and the valve seat 60 and through an annular disk-like passage area 66 in the refinement element 48 around the valve body 58 with the second mixing chamber 40 in Connection is established. Rib-like webs 68 protrude into the annular space 64 in order to achieve a further refinement of the foam and at the same time form a first chicane in order to brake the outflow speed of the foam flowing in the direction of arrow S (see also FIG. 3). These webs 68 also serve to center the valve body 58.

An actuating element 70 can be displaced in the axial direction on the tubular wall part 62 of the holding part 12 guided. The actuating element 70 has an actuating member 72 which is cross-shaped in cross-section and which extends through the wall part 62 in the longitudinal direction, is slidably guided with the radial ends of its ribs 72 'on the inner wall of the wall part 62 and is concave at the end facing the valve body 58, so that it rests against the valve body 58 only with a region of the ribs 72 ′ adjacent to the wall part 62. When the actuating member 72 is moved against the outflow direction S in the actuating direction B, the valve body 58 is thus bent from the closed position shown in FIG. 1 around the support member 50 into an open position in the manner of a membrane. The opening stroke H and thus the width of the annular passage 74 delimited by the valve seat 60 and valve body 58 is defined by limiting means 76 which act in the axial direction and which are formed by a stop 78 formed on the ribs 72 'and the end face on this side cooperating therewith as a counter stop 78' of the wall part 62 are formed.

A cross-sectionally U-shaped ring part 80 is formed on the actuating member 72 and, with its inner wall, seen in the radial direction, slidably abuts the outer wall of the wall part 62. The ring part 80 is open in the direction towards the holding part 12 and, together with the actuating member 72, is overlapped like a hat by an actuating head 82. The actuating head 82 is fastened to the ring part 80 via a collar-ring groove connection 84.

On the side facing away from the valve body 58, the actuating member 72 is spanned by a sieve 86 which bears against the end face of the ring part 80 and between this and the actuating head 82 is clamped. The ribs 72 'of the actuator 72 form baffles in a first channel part 88 of a channel arrangement 90 which directs the foam from the valve arrangement 58' formed by the valve seat 60 and valve body 58 to an outlet 92 provided on the actuating head 82. This first channel part 88 thus extends from the valve seat 60 to the sieve 86 and is delimited on the circumference by the wall part 62 and the ring part 80. The sieve 86 further refines the foam and has a braking effect on it in particular.

An approximately cylindrical cavity 94 is provided in the actuating head 82, which is connected to the channel part 88 through the sieve 86 and which is encompassed by an annular channel 96 (FIG. 2) which opens into the outlet 92. The cavity 94 and the ring channel 96 are further parts of the channel arrangement 90. The common wall 98 of the ring channel 96 and the cavity 94 has on the side facing away from the outlet 92 a plurality of outflow openings 100 which are separated from one another by webs 102 which act as chicanes. The foam flowing into the cavity 94 in the flow direction S through the sieve 86 finds its way through these outflow openings 100 into the annular channel 96 and from there to the outlet 92. By arranging the outflow openings 100 exclusively on the side facing away from the outlet 92 and the webs 102, the foam is slowed down further and forced to flow through the entire annular channel 96. In order to achieve a further braking effect on the foam, rib-like baffles 104 protrude into the annular channel 96.

For the sake of completeness, it should be mentioned that the sieve 86 is pressed by the wall 98 against the end face of the ring part 80. As indicated by dashed lines in FIG. 1, an outlet connection 92 ′ can be formed on the actuating head 82, so that the outlet is offset further outward in the radial direction. If necessary, a cannula can be placed on this outlet connection 92 'in order to bring the foam to locations that are difficult to access.

It should be noted that baffles and parts acting as baffles are arranged along the entire channel arrangement 90 in order to brake the foam and thereby slow down the rapid pressure loss in container 16.

The holding part 12 has a flange part 106 which engages around the actuating head 82 and is formed on the circumferential sealing beads 108, 108 ', which bear sealingly on the socket 14 of the container 16. The free end region of the flange part 106 is bent outwards in the radial direction and bears against the front end of the connector 14. The union nut 18 engages over the socket 14 and the flange part 106 and engages with a tubular flank 18 'in the gap between the flange part 106 and the actuating head 82, around the flange part 106 with its sealing beads 108, 108' and thus the holding part 12 in an axial and radial manner To keep direction close to the nozzle 14. To support the tight mounting, the union nut 18 interacts with an O-ring-shaped seal 112 arranged in a circumferential groove 110 of the connector 14.

All parts of the device 10 with the exception of the sieve-like refinement element 48 and sieve 86 are made Made of plastic. The assembly is extremely simple, but the refinement element 48 can be inserted into the axial opening 20 in the holding part 12 and fastened by means of the mixer part 26 likewise inserted into the opening 20, the collar-ring groove snap connection 24 automatically engaging. Then the holder part 12 with the mixer part 26 mounted thereon is inserted into the socket 14 of the container 16 until the bent end region of the flange part 106 lies against the free end of the socket 14; the two sealing beads 108, 108 'come into contact with the flat inner wall of the connector 14. By screwing the union nut 18 onto a thread (not shown) of the container 16, the holding part 12 is fastened to this container 16. For the assembly of the actuating element 70, the sieve 86 is inserted into the actuating head 82 and the actuating member 72 with the ring part 80 is inserted into the actuating head 82 until the band-ring groove connection 84 engages. The actuating element 70 preassembled in this way is placed on the holding part 12, the actuating member 72 being inserted into the wall part 62. The actuating element 70 is held on the holding part 12 only by the friction between the actuating member 72 and the ring part 80 on the wall part 62 and the friction between the actuating head 82 and the flank 18 ′ of the union nut 18.

The operation of the device 10 for generating and dispensing foam is as follows:
The container 16, which is partially filled with foamable liquid, is pressurized by introducing air into the container 16, for example by means of a pump which is integrated in the container 16 but is not shown but is generally known is pumped. The pressure achieved is preferably 3 * 10⁵ Pa to 7 * 10⁵ Pa (≈ 2 - 6 atm). Smaller pressures are also possible, the foam generation also works at approx. 1.2 * 10⁵ Pa (0.2 atü). Since the valve body 58 is arranged upstream of the valve seat 60, it is pressed against the valve seat 60 by the excess pressure in the interior of the container 16. Even if there is no excess pressure in the container 16, the valve body 58 is held in contact with the valve seat 60 in the closed position by its own elasticity and the elasticity of the refining element 48 as a result of the central support by the support member 50 and the circumferential mounting of the refining element 48 in the holding part 12 in the closed position. In this position, no air and no foam can escape from the container 16, so that the excess pressure is maintained. To remove the foam, the actuating element 70 must be pressed down in the actuating direction B until the stop 78 comes into contact with the counter stop 78 '. As a result of this actuation stroke H of the actuating member 72, the valve body 58 is bent downward into its open position together with the refinement element 48 in the region of the annular valve seat 60, as a result of which the passage 74, which is precisely defined in its dimensions, is released. As a result of the excess pressure in the container 16, liquid is pressed through the liquid passage 34 in the tube 30 and air through the air passages 32 in the opening 28 into the first mixing chamber 38. In this first mixing chamber 38, the liquid is premixed with the air, which is supported by the displacement body 44 and the radial outflow direction of the air passages 32 and the axial outflow direction of the liquid passage 34. This creates coarse foam, which is pressed through the passages 42 into the second mixing chamber 40 and thereby further educated and refined. The coarse foam is conveyed in the passage area 66 through the sieve-like refining element 48 into the annular space 64, as a result of which the coarse foam is refined into a fine foam. The fine foam then flows through the passage 74 between the valve seat 60 and the valve body 58 which is in the open position without being destroyed in the process and is pressed through the channel part 88 to the sieve 86 and through this into the cavity 94. The screen 86 promotes the further refinement of the foam and at the same time extracts kinetic energy from it. The fine foam is then passed from the cavity 94 through the outlet openings 100 into the annular channel 96, where it is fed to the outlet 92 when it is braked by further baffles 104. In addition to the sieve 86, the refinement element 48, the webs 68 in the annular space 64, the specific annular passage 74 as well as the ribs 72 'of the actuating member 72 and the deflections, webs 102 and baffles 104 in the region of the actuating head 82 have a braking effect on the outflow Foam. The braking of the foam enables optimum foam formation under the given pressure conditions and at the same time prevents the excess pressure in the container 16 from dropping rapidly. The foam is not sprayed out of the outlet 92, but rather flows out of it. Once the desired amount of foam has flowed out, the actuator 70 is released, causing the valve assembly to automatically close by the valve body 58 due to its own and the bias of the refinement element 48 and the difference between the upstream and downstream pressure on the active surface of the valve body 58 against the valve seat 60 is moved to and pressed against it. The actuating element 70 is automatically moved as well.

It is also possible to use a different gas instead of air. It is of course also conceivable to manufacture the container and the holding part from thin-walled metal, similar to known aerosol bottles, and to fasten them to one another in a card-like manner. Otherwise, the screen 86 can be omitted; in this case it is possible to form the actuating element in one piece.

Claims (10)

Device for a container for foamable liquid for producing and dispensing foam, with a holding part (12) to be arranged on the nozzle (14) of the container (16) with an axial opening (20) in which a mixer part (26) with one in a mixing chamber arrangement (36) is held with a gas and liquid passage (32, 34) opening out on the outlet side and provided with a sieve-like refining element (48), and a channel arrangement (90) downstream of the refining element (48) in order to convey the foam to an outlet (92 ) and valve arrangement (58 ') with an actuating element (70) for moving a valve body (58), which together with a valve seat (60) defines an annular gap passage (74), from a closed to an open position, characterized in that the Channel arrangement (90) braking means for braking the flow velocity of the foam and the holding part (12) exclusively the axial opening (20th ), and the valve body (58) is arranged upstream of the valve seat (60) and, when the actuating element (70) is actuated against a bias in the open position and when the actuating element (70) is released, can be automatically transferred together with the latter to the closed position, in Limiting means (76) acting in the axial direction are provided in order to fix the open position. Device according to claim 1, characterized in that the refining element (48) is held circumferentially and is designed to be deformable, the disk-shaped valve body (58) is arranged around it leaving an annular passage area (66) in the refining element (48), and this passage area (66) is arranged downstream in one, preferably with the first baffles (68) provided annular space (64) which surrounds the valve seat (60). Apparatus according to claim 2, characterized in that on the side of the deformable, disc-like valve body (58) facing away from the valve seat (60) there is provided an approximately centrally acting support member (50), in order to bear against the valve body (58) on the valve seat (60) to hold, and the actuating element (70) is equipped with an actuating member (72) which acts on the valve body (58), seen in the radial direction, outside the supporting member (50). Device according to one of claims 1 to 3, characterized in that the mixing chamber arrangement (36) has two mixing chambers (38, 40) upstream of the refining element (48), which are formed by several, forming a cross-sectional constriction and around a central displacement body (44) arranged through openings (42) in the mixer part (26) are connected to one another, the support member (50) possibly being integrally formed on the displacement body (44). Device according to one of claims 1 to 4, characterized in that the axial opening (20) in the holding part (12) downstream of the refinement element (48) is delimited by a tubular wall part (62), on the upstream end of which the valve seat (60) is formed, and the actuating member (72) defines that part of the axial opening (20 ) passes through and preferably has ribs (72 ') which project in the radial direction and act as chicanes. Apparatus according to claim 5, characterized in that the actuating element (70) has an actuating head (82) connected to the actuating member (72) and overlapping the wall part (62) in a cap-like manner, on which parts (94, 94) connected to the flow with the central opening (20) 96) of the channel arrangement (90) are formed. Apparatus according to claim 6, characterized in that the actuating head (82) has a ring part (80) which lies circumferentially on the wall part (62) and is preferably spanned by a sieve-like brake member (86). Apparatus according to claim 6 or 7, characterized in that a cavity (94) is formed in the actuating head (82), which is encompassed by an annular channel (96) connected to the outlet (92) and optionally directly adjacent to the brake member (86) , wherein the cavity (94) and the annular channel (96), preferably exclusively on the side facing away from the outlet (92), through connection openings (100) in the common partition (98) separated from one another by baffle-like webs (102) are interconnected. Device according to claim 8, characterized in that rib-like baffles (104) are provided in the ring channel (96). Device according to one of claims 1 to 9, characterized in that a stop (78) is provided on the actuating element (70), optionally on the actuating member (72), which for fixing the open position of the valve body (58) with a on the holding part (12) , optionally on the wall part (62) provided counter-stop (78 ') cooperates.

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