EP0557243A1 - Method and device for the dosed production of foam from liquid soap - Google Patents

Abstract

In the method according to the invention, the liquid soap is conducted into a compensating container (113) and/or a metering container (117), in which there is always a defined quantity of soap and air at the beginning of the dispensing operation. The feed pipe (116) of a frother (121) protrudes into the compensating container (113) or the metering container (117). The lower end of the pipe (116) is immersed in the soap; the upper end is located in the top space. Fitted onto the pipe (116) is the frother (121) in which, when the top space is pressurised with compressed air, the soap pressed through the pipe (116) into the frother (121) is mixed with air from the top space to form foam. <IMAGE>

Description

The present invention relates to a method for the portionwise generation of foam from liquid soap according to the preamble of claim 1.
The invention further relates to a device for the portionwise generation of foam from liquid soap according to the preamble of patent claim 3.

Soap dispensers are known in practice, in particular for toilets and washrooms in public buildings and restaurants, in which a measured portion of liquid soap is dispensed into the hand by actuating a pivoting lever. The disadvantage of these soap dispensers is that they tend to drip, i.e. that, over time, soap accumulates below the soap dispenser on the washing trough or on the floor, which must be removed.

It has therefore already been proposed to squeeze soap foam instead of liquid soap. From the European patent specification 0019582 a device for forming soap foam with a lever solution-operated metering device is known. In this device, aqueous soap solution comes from a storage container into a cylinder chamber which is connected to a metering pump in the form of a piston, which also serves as a slide for a piston outlet opening, which leads to a mixing chamber which is connected to a diaphragm pump. The diaphragm pump is actuated by an actuating lever at the same time as the metering piston. In the initial position, liquid soap solution can flow from the reservoir into the cylinder space of the metering pump. By swiveling the operating lever Soap solution in the cylinder chamber of the metering pump pressed into the mixing chamber. A flap valve prevents it from flowing back into the cylinder space of the metering pump. When the actuating lever is returned by a return spring in the diaphragm pump, air is pressed into the mixing chamber by the latter and a coarse-bubble foam is generated. This is then passed through a porous body into an expansion space and is supposed to exit from there as a fine soap foam via the outlet opening.
In practice, it has been shown that the foam of this known device varies greatly in consistency, which can be attributed to the fact that deposits in the narrow connecting lines and the porous filters mean that the conditions for foam formation with regard to pressure and mixture ratio do not remain constant over a long period of time can be held. Furthermore, the known device requires a large amount of maintenance to maintain reasonably constant conditions. This is cumbersome and expensive.

The invention seeks to remedy this.
The invention has for its object to provide a method and an apparatus in which, regardless of the level of the soap container, the same amount can always be produced with properties that can be determined in advance.

This object is achieved by a method according to the characterizing features of patent claim 1 and a device according to the characterizing features of patent claim 3.

Surprisingly, the interposition of an expansion tank in which a defined amount of soap and air always flows after each pump stroke keeps the consistency and the amount of foam constant. By adjusting the length of the connecting line from the storage tank to the expansion tank, the amount of soap and air in the expansion tank can be changed and thus the ratio between air and soap in the foam and adjusted to the soap quality and viscosity used. A tube arranged in the expansion tank enables easy assembly and - if necessary - replacement of the foamer and allows foam residues to be sucked back or blown off at the dispenser opening at the end of the dispensing process and to prevent dripping.

By interposing an expansion tank, the head space above the soap can be easily, e.g. be kept constant within very narrow limits by the immersed tube from the storage container.

The device according to the invention has a very simple structure with an inexpensive foamer, as is already known on the market, and can also be replaced in a simple and inexpensive manner if used very frequently. By changing the immersion depth of the filling tube, the amount of soap or the consistency of the foam can be easily adapted to the needs. This is particularly advantageous if the quality of the soap is not constant. When using a dosing tank, the head space above the soap can be kept very small and thus the pump volume can be kept small.On the other hand, the air required to fill the pump can be passed outside the head space so that there is no foam formation when the lever is actuated very often can be done. In the private sector, where only a few application processes are carried out, the simple implementation can easily suffice. By arranging a jacket around the foam dispensing tube, the air flowing back into the pump can lead foam residues back into the expansion tank at the end of the foam feeding tube. Appropriate formation of a collecting space in the return housing can easily prevent soap residues from getting into the pump. When using two oppositely acting pumps, instead of sucking back foam residues, blowing off can also be effected. This also has the advantage that the air required to fill the pressure pumps comes directly from the room and can be done at a distance from the foam dispensing opening.
The connection of the operating lever to the pump via a spring allows a progressive build-up of pressure and thus a perfect mixing of the air and the soap when the foam is formed. The embodiment of the invention according to FIGS. 5 and 6 enables a very simple, stable and inexpensive construction of the actuating lever and its storage in the housing. The star-shaped arrangement of the pumps also allows a very compact design of the foam dispensing device. This in turn makes it possible to install the device according to the invention in already existing housings for conventional dispensing devices.

Figur 1

einen Längsschnitt durch eine Schaumspendevorrichtung,

Figur 2

einen Längsschnitt durch eine weitere Schaumspendevorrichtung

Figur 3

eine vergrösserte Darstellung des Schäumers in Figur 2,

Figur 4

eine schematische Darstellung einer weiteren Ausführung,

Figur 5

eine schematische seitliche Darstellung einer weiteren Anordnung der Pumpen und deren Betätigungshebel vor dem Spenden,

Figur 6

die Anordnung in Figur 5 am Ende der Hebelbewegung.

The invention is explained in more detail on the basis of illustrated exemplary embodiments. Show it:

Figure 1

a longitudinal section through a foam dispensing device,

Figure 2

a longitudinal section through a further foam dispensing device

Figure 3

2 shows an enlarged view of the foamer in FIG. 2,

Figure 4

a schematic representation of a further embodiment,

Figure 5

a schematic side view of a further arrangement of the pumps and their actuating lever before donation,

Figure 6

the arrangement in Figure 5 at the end of the lever movement.

The foam dispensing device 1 is accommodated in a housing 3, which can be attached to a wall 5, and is made of plastic or sheet metal. In the housing 3, a storage container 7 is accommodated with a nozzle 9 attached to its base 8, which is connected via a connecting line 11 to an expansion tank 13. The line 11 dips from above through an opening 15 into the expansion tank 13 by the amount X. If desired, the line 11 can be telescopic in order to make the immersion depth X adjustable (indicated by broken lines).
The lower end of the line 11 is closed by a membrane valve 12, which on the one hand allows the entry of liquid soap 27 from the storage container into the expansion tank 13, but, when the expansion tank 13 is pressurized, does not allow liquid soap to escape from the expansion tank 13 into the storage tank 7. The design of the valve 12 is not described in detail, since such valves are sufficiently known from the prior art.

A so-called foamer 21, as described, for example, in Swiss Patent No. 545322, is placed on a connector 14 on the expansion tank 13. The foamer 21 consists of a soap supply pipe 16, the upper end of which has a central opening or a large number of fine bores 18. A fine-pored sieve or sintered plate 20 lies above the bores 18 and at a distance from them. The upper end of the jacket of the line 16 has fine bores 22 which are connected to the interior of the expansion tank 13. The annular space outside of the fine sieve 20 is spanned by an annular membrane seal 24 which, in the event of overpressure in the expansion tank 13, only allows air to escape through the fine sieve 20, but allows negative air to enter the head space 45 if there is negative pressure inside.

The expansion tank 13 is further connected by a line 36 to a bellows 35 acting as a pump. A transmission lever 41 engages on the bellows 35 and is mounted on the housing 3 so as to be pivotable about an axis B. An actuating lever 39, which projects out of the housing 3 at the bottom, can be pivoted about an axis A and is articulated to the transmission lever 41 with a second axis C. A return spring 47 is inserted in the bellows 35, which returns the bellows 35 to the starting position when there is no force F on the actuating lever 39. Alternatively, the spring 47 can of course also engage one of the levers 39 or 41.

The generation of a foam portion with the device according to FIG. 1 is explained in more detail below.
By pivoting the operating lever 39, translated by the transmission lever 41, the bellows 35 is pressed together. The air in the bellows 35 flows through the line 36 into the head space 45 of the expansion tank 13. The inflowing air increases the pressure p1 in the head space 45. The pressure increases above the surface of the liquid soap 27 in the expansion tank 13, soap is from below into the line 17 pressed and exits the line 17 through the fine bores 18. Before the soap passes through the bores 18, air from the head space 45 enters the rising soap into the line 17 through the peripheral bores 22 and mixes intensively with the latter to form foam S, which can escape to the outside through the foam dispensing tube 26. During the build-up of pressure and the formation of foam in the foamer 21, the valve 12 on the nozzle 9 is closed. After the pressure build-up has ended, the pressure p1 in the expansion tank 13 drops since the actuating lever 39 returns to the starting position and air can enter the head space 45 through the opening membrane seal 24. Air can flow back through the line 36 into the bellows 5 and fill it up again. After the pressure drop in the expansion tank 13, liquid soap flows through the nozzle 9 from the storage tank 7 down through the valve 12 into the expansion tank 13 until the amount of soap squeezed out during foaming is replaced. The level h2 is determined by the immersion depth x of the connecting line 11. Instead of returning air through the membrane seal 24, a corresponding valve can also be used at another location of the expansion tank 13.
The foam dispensing tube 26 can also be surrounded by a jacket 28 through which the air is sucked back into the bellows 35. Any remaining foam at the end of the tube 26 can be sucked back into the expansion tank.

As an alternative to the two-part lever system 39, 41, a plate, step angular or star-shaped lever 50 (indicated by dash-dotted lines in FIG. 1), which is pivotally mounted about the axis A to the side of the pump 35. The stroke when the pump 35 is actuated thereby becomes somewhat smaller. This can be compensated for by a correspondingly larger bellows.

In a further embodiment of the invention according to FIG. 2, a foam dispensing device 101 is shown with a housing 103 which is attached to a wall 105. In the housing 103, a storage container 107 is accommodated with a connection piece 109 attached to its base 108 and connected to an expansion tank 113 via a connecting line 111. The line 111 dips into the expansion tank 113 from above through an opening 115. In a tubular recess 161, a tube 117 is inserted, on the bottom 162 of which a valve 163 is arranged. A second pipe 116, the lower end of which is open and the foamer 121 is placed on the upper end, projects into the first pipe 117. An O-ring 165 can be used to seal the tube 117 with respect to the tubular recess 161. The tube 117 forms a metering accumulator 110 with a volume that is substantially smaller than that of the expansion tank 113.

A bellows pump 135 is placed over the storage container 107 and is articulated by a lever or linkage 141 to a two-armed actuating lever 139. Instead of an articulated connection 142 (solid lines in FIG. 2), the operating lever 139 and the two-armed lever 141 can also be connected to one another by a spring 144 inserted between the articulated connection point 142 and the end 146 of a shortened lever 141. The spring 144 is designed to progressively build up the force on the bellows 135 when the actuating lever 139 is operated (pivoting counterclockwise) by tensioning the spring 144 and to continue to compress the bellows 135 even after the pivoting movement of the actuating lever 139 has ended.

A spring 147 is intended, after the actuation lever 139 has been pivoted and thus after the bellows 135 has been compressed, to move the bellows 135 back into the starting position and to fill it with air.
A connecting line 136 leads from the bellows 135 to the head of the foamer 121, which is surrounded by a housing 169.

The formation of the foamer 121 is explained in more detail with reference to FIG. 3. The foamer 121 is inserted into the end of the tube 117. A dip tube 116 open at the bottom leads from the foamer 121 to close to the lower entrance of the tube 117. The upper end of the tube 116 ends under the fine bores 118 in the foamer 121 and opens at a distance from a fine-meshed sieve 120. Above the sieve 120 and in contact with the latter begins a foam dispensing line 126, from the end of which the foam S is dispensed onto the hand. Fine channels 122 at the upper end of the dip tube 116 lead into the space between the bores 118 and the soap surface in the tube 117.

The tube 117 is connected at the top via a valve 146 to the line 136 with the bellows 135. The foam dispensing tube 126 leads through an intermediate wall 167 within the housing 169. The housing 169 is also connected to the line 136 by a first diaphragm valve 171. A collection space 172 for the liquefaction of sucked-back foam S can be provided between the valves 146 and 171.

The foam dispensing device 101 in the embodiment according to FIGS. 2 and 3 works as follows. After the storage container 107 has been inserted, liquid soap 127 flows through the nozzle 109 into the expansion tank 113 until a level of h2 is reached. Through the valve 163, the liquid soap can also enter the tube 117 from below and also fill it up to the height h2. By pulling the actuating lever 139, the pump designed as bellows 135 is compressed via the linkage 141 and at the same time the return spring 147 curious; excited. In order to obtain the largest possible amount of air with a short pump stroke, two bellows pumps 135 can also be arranged side by side in parallel. When the bellows 135 is pressed together, air is passed through the line 136 and through the second valve 146, which opens due to the increased pressure, into the head space 145 between the foamer 121 and the surface h2 of the liquid soap 127 in the tube 117
pressed in. Due to the pressure increase on the soap surface in the tube 117, the soap is pressed simultaneously from below through the liquid supply tube 116 and its upper end with the fine bores 118 into the foamer 121 and with the air which can get into the foamer 121 through the bores 122, mixed and created a foam. The foam can exit the foamer 121 through the foam dispensing tube 126. After releasing the actuating lever 139, it is pulled back by the return spring 147 and returns to the starting position. The expanding bellows 135 draws air through the line 136 through the valve 171 from the space between the pipe 126 and the housing 169 and at the same time draws air from the environment at the end of the pipe 126. Any foam residue left there is sucked back into the foamer 121 and can return into the pipe 117 the next time air is applied through the valve 146. Liquid soap is never sucked up into the bellows 135, which is located at the highest point of the device, and no contamination can occur. Furthermore, the described manner of recycling foam residues prevents foaming of the liquid soap 127 in the expansion tank 113.
Instead of sucking back foam residues when filling the bellows 135, the bellows can be filled directly through a valve arranged on the bellows 135 (no illustration). To prevent dripping at the end of the tube 126, a further bellows can be provided, which is pressed together when the actuating lever 139 returns and blows off foam residues into the hand through a line with an air jet.

Such a device is shown in Figure 4.

In a housing 203, two bellows 235 serving as a pump are arranged on the rear wall and are connected to the actuating lever 239 via a T-shaped lever 241. The operating lever 239 is two armed and pivotable about the point A. Analogous to the embodiment according to FIG. 2, the operating lever 239 can also be connected to the T-shaped lever 241 by a spring 244 in order to enable progressive pressure build-up in the bellows 235.
The end of the second arm of the operating lever 239 engages a third bellows pump 235 '. The two bellows 235 are connected via feed lines to a pressure line 238, which opens into an expansion tank 213 and into a space 280 in which the foamer 221 is located. At the end of line 236, a check valve 263 is inserted, which prevents air from being sucked out of head space 245 when the two bellows 235 are refilled. The bellows are filled by valves 240.
The expansion tank 213 is connected to a storage tank 207 by a line 209. At the end of the line 209 there is also a check valve 212 which, when the pressure in the head space 245 is built up, prevents the liquid soap 227 from flowing back into the container 207 through the two bellows 235. A foamer 221, as has been described in FIG. 1, is inserted in a pipe socket 217. A dip tube 216 attached to it dips into the liquid soap 227. The foam dispensing tube 226 begins above the foamer 221 and ends at the front of the housing 203. A line 281 leads from the bellows 235 'to the end of the discharge pipe 226. The line 281 preferably opens out somewhat offset from the line 226. When the operating lever 239 is pulled to the broken position in the firmly extended position, the two bellows 235 are pressed together by the linkage 241 and the contents of the bellows pass through the line 236 into the head space 245 of the expansion tank 213. By increasing the pressure on the Surface of the liquid soap 227 is pressed through the dip tube 216 into the foamer and there with the air also entering the foamer 221 from the head space to form a foam mixed. The foam can escape through the pipe 226 to the outside. As soon as the operating lever 239 is released, it returns to the starting position by means of corresponding springs, which can be installed, for example, in the two bellows 235 (not shown) or by a spring which acts directly on the operating lever 239 (not shown). The bellows 235 'is pressed together (as shown in FIG. 4). Its content is then led through the line 281 past the opening of the tube 226 and at most blows away any foam still hanging there.

As an alternative to the levers 239, 241, a single plate-shaped, angle-shaped or star-shaped lever 250 (plate-shaped design indicated by dash-dotted lines) can also occur in this embodiment of the invention, which is pivotably mounted about the axis A and one end of which is connected to the pump 235 'and with its part shown on the left is connected to the rear of the pumps 235. The lever 250 can also consist of two parallel plates arranged to the side of the pumps 235. In this embodiment, the axis A can be supported on both sides of the housing 203, so that an extremely stable arrangement results.

In the embodiment of the invention according to FIGS. 5 and 6, the axis of rotation A of the one-piece operating lever 339 is arranged essentially point-symmetrically between the pumps 335 and 335 '. The three pumps are each offset by 90 ° around pivot point A. Spherical connecting elements 370 are fastened to the actuating lever 339 on a support 360 projecting laterally from the latter, said connecting elements engaging in appropriately designed dome-shaped recesses 380 on the rear sides of the pumps 335, 335 '. Instead of the spherical connections, other suitable connection means can also be used.
The expansion tank 313 and the foamer 321 with the dispensing tube 326 are only shown schematically; they can have the same design as in FIGS. 1 to 4. The connecting lines 336 and 386 between pumps 335 and 335 'are only shown as simple lines for the sake of clarity.
FIG. 5 shows the two pumps 335 used to generate a pressure in the expansion tank 313 in the filled state; the pump 335 ', with which the amount of foam remaining in the dispensing tube 326 is blown out at the end of the dispensing process, is completely compressed before the actuation lever 339 begins to pivot in the direction of arrow F. The operating lever 339 is in the starting position. In FIG. 6, the operating lever 339 has been turned forwards by the operator, that is to say in a counterclockwise direction. The two pumps 335 responsible for the pressure build-up in the expansion tank 313 are now completely compressed and the pump 335 'used for blowing out is filled. When the lever 339 is released, it is turned back by a spring (not shown), which can be arranged within the pumps 335, 335 'or otherwise act on the lever 339, the pump 335' is pressed together and the remaining amount of soap foam is thereby expelled from the end of the donor tube 326 . The arcuate course of the spherical connecting elements 370 when the lever 339 is actuated has no influence on the action of the pumps 335 and 335 ', since the lateral offset during the pump stroke is either absorbed by the elasticity of the bellows-type pumps 335, 335' or - as in FIG 5 and 6 - the connecting elements 370 can slide laterally in the recesses 380. The embodiment of the actuating lever 339 shown in FIGS. 5 and 6 in turn has the advantage that the lever 339 consists of two plates arranged to the side of the pumps 335, 335 'and therefore the axis A can be fastened on both sides of the housing 303. The lever 339 can therefore easily be made of plastic and with a small wall thickness inexpensively.

Claims (15)

Process for the batchwise generation of foam from liquid soap in a soap dispenser, in which soap and air are pressed and mixed into a foamer, characterized in that the liquid soap (27, 127, 277) is initially passed from the storage container (7, 107, 207) into an expansion tank (13, 113, 213) until the volume of soap and air in the head space (45,145,245) above the soap (27,127,227) in the expansion tank (13,113,213) has a defined value and
that the head space (45, 145, 245) is pressurized with air by a pump (35, 135, 235, 355) at the same time, on the one hand, soap (27, 127, 227) is pressed from below through an immersion tube (16, 116, 216) into the foamer (21, 121, 213, 313) connected to the expansion tank (13, 113, 213, 331) and, on the other hand, is pressed in Part of the air enters the soap (27,127,227) pressed into the foamer (21,121,221,321) and mixes with the soap (27,127,227) to form foam. A method according to claim 1, characterized in that the soap (127) is passed through a valve (163) from the expansion tank (113) into a metering tank (110) connected to the expansion tank (113), at the upper end of which the foamer (21) is arranged, and that there the head space (145) above the soap (127) is pressurized with compressed air from the pump (135,335). Device for the generation of portions of foam from liquid soap in a soap dispenser, with a storage container for liquid soap, a foamer for mixing soap with air and with a pump, characterized in that between the storage container (7,107,207) and the foamer (21,121,221,321) Expansion tank (13,113,213,313) to hold a defined soap and Air quantity is used that the foamer (21,121,221,321) is connected to the expansion tank (13,113,213) by a soap supply pipe (16,116,216) and that the head space (45,145,245) above the liquid soap (27,127,227) in the expansion tank (13,113,213,313) and the foamer (21,121,221,321) connected to the pump (35,135,235,335). Device according to claim 3, characterized in that a connecting line (11,111,211) projecting from above into the expansion tank (13,113,213,313) is attached from the storage container (7,107,207), the length (X) of the immersing end of the connecting line (11,111,211) being the size of the Headspace (45,145,245) and the amount of soap (27,127,227) is adjustable. Device according to one of claims 3 or 4, characterized in that the foamer (21,121,221,321) is placed on a connection piece (14, 114,214) on the expansion tank (13,113,213,313), the lower end of the feed pipe (16,116,216) being inserted into the soap (27,127,227) Expansion tank (13,113,213) protrudes and the upper end in the head space (45,145,245) comes to rest over the soap (27,127,227). Apparatus according to claim 3, characterized in that between the expansion tank (113,313) and the foamer (121,321) a dosing tank (110) is inserted which is connected to the expansion tank (113,313) via a valve (163). Apparatus according to claim 6, characterized in that the dosing container (110) consists of a tube (117) projecting into the expansion tank (113,313), the lower end of which is connected to the interior of the expansion tank (113,313) and through the valve (163) can be closed, and that the foamer (121, 321) is placed on the upper end of the tube (117). Device according to one of claims 6 or 7, characterized in that the head space (145) in the tube (117) is connected to the pump (135, 335) by a line (136) and by a valve (146). Apparatus according to claim 8, characterized in that the foamer (121, 321) is at least partially surrounded by a housing (169), which housing (169) next to the point of exit for the foam open to the environment and to the rear via a valve (171) with the line (136) and the pump (135,335) is connected. Device according to one of claims 8 or 9, characterized in that the valves (146, 171) are used in a collecting space (172) which is connected to the line (136). Device according to one of claims 3 to 10, characterized in that the pump (35,135,235,335) can be actuated with an actuating lever (39,139,239,339) and air can be pressed into the head space (45,145,245), and / or that the lever (141,241) is actuated by a spring (144,244 ) is connected to the operating lever (139, 239). Device according to one of Claims 2 to 5, characterized in that the first pump or the first two pumps (235, 335) is provided for loading the head space (245) and a second pump (235 ', 335') is provided for blowing off foam residues is connected to the foam dispensing tube (226, 326) by a line (281). Device according to one of claims 3 to 10, characterized in that the actuating lever (39, 139, 239, 339) is pivotally mounted on a pivot axis (A) and in operative connection with the pumps (35,135,235,335) and (35 ', 135', 235 ', 335'). Device according to claim 13, characterized in that the pumps (335, 335 ') are arranged essentially point-symmetrically about the pivot axis (A) of the actuating lever (39, 139, 239, 339). Device according to one of claims 13 or 14, characterized in that the actuating lever (39, 139, 239, 339) is plate-shaped.

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