A foam dispenser

[0001] This disclosure relates to foam dispensers, in particular dispensers that may have an elastically deformable dome of the piston, and dispensers that may have an improved mixing chamber.

[0002] The present disclosure relates to foam dispensers and more specifically to non-aerosol foam dispensers or non-pressurized foam dispensers. The popularity of this type of foam dispenser has increased rapidly over the past decade and is now widely used around the world. The advantage of foam dispensers compared to traditional liquid dispensers is that they consume much less liquid for each use, i.e. the dose. For example, if the foam dispenser is used for hand hygiene, either as a soap dispenser or an alcohol foam dispenser, considerably less liquid is consumed with each hand washing operation than would be consumed with a simple liquid dispenser.

[0003] However, there are always favorable circumstances to reduce the cost of production, either by reducing the number of elements or by simplifying the production process. There are also favorable circumstances to improve foam quality or, as an alternative, to produce a commercially acceptable foam in the device that can be produced at a reduced cost.

[0004] WO 2011/064584 A1 discloses a dispenser with a manual pump that includes an upper membrane and a bottom diaphragm. The upper membrane forming the air chamber is formed for air movement, while the lower membrane forming the liquid chamber is formed for the movement of the liquid.

[0005] JP H04 187256 A relates to a method and apparatus for spraying a liquid chemical agent. Represents a spray device connected to a flexible hose, the spray device comprising a venturi tube.

[0006] US 2 183 561 relates to a mechanical foam generator for generating foam for fighting fires.

SUMMARY [0007] The foam generating unit connected to the liquid container comprises a main pump body, a piston dome, an air chamber, a liquid chamber, a mixing zone and attached to the main pump body, whereby the piston cup is elastically deformable dome of the piston and has a rest position and compression position. The air chamber is formed by the piston dome and the main pump body. The liquid chamber is formed by the piston dome and the main pump body and has a liquid inlet valve and a liquid outlet valve. The mixing zone is in fluid communication with the air chamber and is in fluid communication with the liquid chamber. The porous element is in the discharge nozzle behind the mixing zone. The volume of the air chamber and the volume of the liquid chamber depend on the position of the piston dome,

[0008] The foam dispenser includes a liquid container; main pump body, piston dome, air chamber, liquid chamber, mixing zone and porous element. The main pump body has an output nozzle. The piston dome is attached to the main pump body, so that the piston dome is elastically deformable with the piston dome, and has a rest position and compression position. The air chamber is formed by the piston dome and the main pump body. The liquid chamber is formed by the piston dome and the main pump body, and has a liquid inlet valve and a liquid outlet valve. The mixing zone is in fluid communication with the air chamber and is in fluid communication with the liquid chamber. The porous element is in the discharge nozzle behind the mixing zone. The volume of the air chamber and the volume of the liquid chamber depend on the position of the piston dome,

[0009] The main pump body may comprise a part of the main pump body and a liquid and air conduit. The liquid inlet valve can be integrally formed in the liquid and air duct. The liquid and air duct may further comprise an air path formed integrally therein, the air path extending between the air chamber and the mixing zone.

[0010] The foam generating assembly may further comprise an air inlet valve in fluid communication with the liquid container. The air inlet valve can be integrally formed in the liquid and air duct.

[0011] The mixing zone may comprise an elongate mixing duct, and the mixing duct may have an inlet end and an outlet end, and the liquid chamber may be in fluid communication with the inlet end of the mixing duct via the liquid outlet valve. The foam generating unit may further comprise a chamfer at the outlet end of the mixing channel where the bevel extends towards the outlet. The mixing channel may further comprise a plurality of air ports arranged downstream of the inlet end of the mixing channel. The foam generating unit may further comprise a mixing pipe and a mixing channel, and the chamfer may be formed in the mixing pipe. In addition, further air ports may be formed in the mixing pipe. There may be many air ports. Many air ports can be four air ports evenly spaced around the mixing channel. The plurality of air ports may be two air ports equally spaced around the mixing channel.

[0012] The foam generating assembly may further comprise one foam tube, wherein the foam pipe has a porous element attached to its one end. The foam pipe may have a second porous element attached to its second end. The foam generating assembly may further comprise a second foam tube, the second foam tube having a porous element attached to its one end.

[0013] The liquid container may be a vertical liquid container, an inverted liquid container, an inverted bag, or a vertical bag.

[0014] The mixing zone may comprise at least one air port in front of the elongated mixing channel.

[0015] The foam dispenser may comprise a dispenser housing having a button for engaging the plunger dome.

[0016] The mixing pipe, for use in a foam generating unit having an air chamber and a liquid chamber and means for generating pressure in the air chamber and the liquid chamber, comprises an elongate mixing channel and an exit zone. The longitudinal mixing channel has an inlet end and an outlet end. The exit zone is at the outlet end of the mixing channel, where the slant of the exit zone extends towards the outlet.

[0017] The exit zone may be a slant which expands towards the outlet.

[0018] The longitudinal mixing channel and the exit zone may form a longitudinal venturi tube.

[0019] The mixing tube may comprise at least one air port in the elongated mixing duct, and the air port is in fluid communication with the air chamber.

[0020] The air port may be a plurality of air ports arranged around the mixing channel.

[0021] The foam generating unit connected to the liquid container comprises a pump, a mixing zone and a porous element. The pump has an air chamber and a liquid chamber. The pump has an activation stroke in which the pump moves from the rest position to the compression position, and a return stroke in which the pump moves from the compression position to the rest position. The volume of the air chamber and the volume of the liquid chamber are much smaller in the compression position. The mixing zone is in fluid communication with the air chamber and in fluid communication with the liquid chamber. The mixing zone has an elongate mixing channel having a cross-sectional area and an exit zone behind the elongated mixing channel. The exit zone has a cross-sectional area larger than the cross-sectional area of ​​the mixing channel.

[0022] The exit zone may be a slant which expands towards the outlet.

[0023] The longitudinal mixing channel and the exit zone together may form a longitudinal venturi tube.

[0024] At least one air port may be formed in the elongated mixing duct, and each air port is in fluid communication with the air chamber. The at least one air port may be a plurality of air ports arranged around the longitudinal mixing channel.

[0025] The volume of the liquid chamber up to the volume of the air chamber can be between 1: 2 and 1:50.

[0026] The volume of the liquid chamber to the volume of the air chamber can be between 1: 8 and 1: 9 [0027] Further features will be described or become apparent from the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS [0028] A foam dispenser and an improved mixing chamber will now be described only by way of example, with reference to the accompanying drawings, in which:

Fig. 1 is a perspective view of an embodiment of the foam dispenser; Fig. 2 is a sectional view of the foam dispenser of Figure 1; Fig. 3 is an exploded perspective view of the foam dispenser of Figures 1 and 2; Figure 4 is a sectional view of the assembled pump body including a portion of the main pump body and the liquid and air conduit of the foam dispenser; Fig. 5 is an enlarged sectional view of a part of a folded pump body including a part of the main pump body and a liquid and air duct showing an air inlet valve;

Figure 6 is an enlarged sectional view of a portion of the pump body including a portion of the main pump body and a fluid and air duct showing the liquid exit valve in the closed position;

Figure 7 is an enlarged sectional view of a portion of the pump body including a portion of the main pump body and a fluid and air conduit similar to that shown in Figure 6 but showing the liquid exit valve in the open position;

Figure 8 is an enlarged sectional view of a portion of the pump body including a portion of the main pump body and a fluid and air conduit similar to that shown in Figure 6, but also including a mixing tube;

Fig. 9 is an enlarged perspective view of the mixing pipe; Fig. 10 is an enlarged section of the foam tube; Figure 11 is an enlarged sectional view of a portion of the pump body including a portion of the main pump body and a fluid and air conduit similar to that shown in Figure 8, but also including a foam tube; Fig. 12 is an enlarged sectional view of a portion of a pump body including a portion of the main pump body and a fluid and air conduit similar to that shown in Figure 11 and illustrating the air flow during the activation stroke;

Figure 13 is an enlarged sectional view of a portion of the pump body including a portion of the main pump body and a fluid and air conduit similar to that shown in Figure 11, and illustrating the air flow during the return stroke;

Figure 14 is an enlarged sectional view of a portion of the pump body including a portion of the main pump body and a fluid and air conduit similar to that shown in Figure 11 and illustrating the flow of liquid during the activation stroke;

Fig. 15 is a sectional view of the foam dispenser similar to that shown in Figure 2 and showing the flow of liquid during the return stroke; Fig. 16 is a perspective view of an alternative embodiment of a foam dispenser with an inverted cartridge;

Figure 17 is an exploded perspective view of the foam dispenser assembly of Figure 16;

Fig. 18 is an enlarged sectional view of the foam generating unit and a part of the inverted cartridge of the dispenser of Figure 16; Figure 19 is an enlarged sectional view of the foam generating unit and a portion of the reverse cartridge, similar to that shown in Figure 18, and illustrating the air and liquid flow during the activation stroke; Fig. 20 is an enlarged sectional view of the foam generating unit and a portion of the inverted cartridge similar to that shown in Figure 18, and illustrating the air and liquid flow during the return stroke; Fig. 21 is a perspective view of another alternative embodiment of a foam dispenser with a bag;

Figure 22 is an exploded perspective view of the foam dispenser assembly of Figure 21;

Figure 23 is an enlarged sectional view of the foam generation assembly and the portion of the inverter dispenser cartridge of Figure 21; Figure 24 is an enlarged sectional view of the foam generating assembly similar to that shown in Figure 23, and illustrating the air and liquid flow during the activation stroke;

Fig. 25 is an enlarged sectional view of the foam generating unit and a portion of the inverted cartridge, similar to that shown in Figure 23, and illustrating the air and liquid flow during the return stroke;

Figure 26 is a sectional view of the prior art foam assembly;

Figure 27 is a sectional view of an alternative foam generation unit comprising a mixing pipe and illustrating the air and liquid flow during the activation stroke;

Fig. 28 is a sectional view of an alternative foam generation unit comprising a mixing pipe, shown in Fig. 26, but showing air and liquid flow during a return stroke;

Fig. 29 is a sectional view of a part of an alternative foam generating unit showing a mixing tube, but made 90 degrees with respect to the views shown in Figures 26 and 28;

Fig. 30 is a cross-sectional view of an alternative embodiment of the foam generating assembly during a return stroke, the foam generation assembly being similar to that shown in Figures 27 to 30, but showing a different path for air to the mixing chamber;

Figure 31 is a cross-sectional view of the foam generating assembly of Figure 30 during the activation stroke;

Figure 32 is a cross-sectional view of the foam assembly of Figure 30 but made 90 degrees with respect to it;

Figure 33 is a cross-sectional view of the foam assembly of Figure 31 but made 90 degrees with respect to it;

Fig. 34 is a cross-sectional view of an alternative prior art foaming assembly;

Figure 35 is a sectional view of the modified version of the foam generation assembly of Figure 34, illustrating an air flow path and a liquid flow path at a return stroke;

Fig. 36 is a section similar to that shown in Figure 35, but showing an air flow path and a liquid flow path at the activation stroke;

Fig. 37 is a cross-sectional view of the foam dispenser of Figures 16 to 21 in the dispenser housing; and Figure 38 is a sectional view of the foam dispenser and housing of Figure 37, but showing a return stroke.

DETAILED DESCRIPTION [0029] Referring to Figures 1, 2 and 3, an embodiment of the foam dispenser is generally designated as 10. The dispenser 10 comprises a liquid container 12 and a foam generating unit 14. For reference, the inlet and outlet are determined during the activation stroke, and therefore the inlet is where the liquid begins to move in the liquid container 12, and the outlet is where it ends and exits the foam dispenser through the outlet nozzle 44. The activation stroke is when the pump or the piston dome 30 is pressed and the return stroke is when the piston dome or the pump returns to its rest position.

[0030] The pump has an activation stroke in which the pump moves from the rest position to the compression position, and a return stroke in which the pump moves from the compression position to the rest position. The volume of the air chamber and the volume of the liquid chamber are much smaller in the compression position. The foam generating unit 14 has an air chamber 16 in fluid communication with the mixing zone 19, and a liquid chamber 20 in fluid communication with the mixing zone 19. The liquid chamber 20 is in fluid communication with the liquid container 12 and has a liquid inlet valve 22. The liquid discharge valve 24 is between the liquid chamber and the mixing zone 19.

[0031] In one embodiment, the foam generating unit 14 includes a main pump body 28 and a dome 30 of the piston. The main pump body 28 includes a liquid and air conduit 32 which is press fit into the main pump body portion 29, as is best seen in FIG. 4. The liquid and air conduit 32 of the main pump body 28 and the plunger dome together form the liquid chamber 20, and it has integrally formed a liquid inlet valve 22 that includes a portion 33 the liquid chamber body and a liquid piston portion 35 as shown in FIG. 2. The main pump body portion 29 includes a dip tube 34 that extends into the liquid container 12 as shown in FIG. 2. A adapted valve seat 36 is arranged at one end of the dip tube 34 at the transition to the liquid chamber 20. The liquid inlet valve 22 is seated on the adapted valve seat 36 and pushed to the closed position. The liquid inlet valve 22 selectively controls the liquid inlet to the liquid chamber 20 and reacts to the pressure reduction in the liquid chamber. The liquid and air conduit 32 and the plunger dome 30 define the air chamber 16. The air path 38 is formed by the liquid and air conduit 32 and provides an air flow path between the air chamber and the mixing zone 19. The mixing zone 19 in the embodiment shown in figures 1 to 16 is a mixing tube 18.

[0032] In the embodiment shown here, the liquid container is a vertical liquid container 12. The liquid and air conduit 32 includes an air inlet valve 26, which is a non-return valve for allowing air to enter the liquid container 12. When the liquid and air conduit 32 is pressed into the portion 29 of the main pump body, the air inlet valve 26 is biased into the closed position. The air inlet valve 26 opens to the open position when the pressure in the bottle reaches a predetermined pressure in such a way that the liquid container does not collapse. A matching cup 40 is formed in the main pump body portion 29, and the sealing element 42 formed in the air inlet valve 26 is sealed in the matching bell to the point

[0033] In one embodiment, the main pump body part 29 has an output nozzle 44 formed therein, as best seen in figures 6 and 7. The liquid outlet valve 24 is press-fitted into a part of the main pump body portion 29. The liquid exit valve 24 is positioned in the fluid outlet 46 of the liquid chamber 20. The liquid exit valve 24 functions similarly to the umbrella valve in such a way that it moves in response to the pressure in the liquid chamber 20 from the rest position, as shown in figure 6, to the position open, as shown in FIG. 7. The liquid outlet valve selectively controls the liquid flowing from the liquid chamber 20 to the mixing tube 18. The arrows 48 show the liquid flow path when the liquid exit valve 24 is in the open position.

An embodiment of the mixing pipe 18 is shown in figures 8 and 9. The mixing tube 18 is fitted in a press fit in the outlet nozzle 44. The mixing tube 18 has a central elongated mixing channel 50. The mixing tube 18 acts as a stop for the liquid outlet valve 24. The liquid outlet 46 is in fluid communication with the inlet end of the elongated mixing channel 50 via the inner annular liquid channel 52. The elongate mixing channel is relatively long and narrow, forming a channel from the inlet end to the outlet end. The air is directed to the central longitudinal mixing channel 50 through at least one air port 54, and in the embodiment shown here via a plurality of air ports 54. In this embodiment, there are four air ports 54, evenly distributed about a central longitudinal mixing channel 50. The mixing tube has an annular gap 56 that in situ produces an outer annular air channel 58. The air channels 59 connect the annular air channel 58 and the air ports 54. Thus, air flows from the air chamber 16, through the air path 38 in the liquid and air conduit 32, to the external annular air channel 58, into the air duct 59, through the air ports 54, and to the central longitudinal mixing channel 50. At the outlet end of the central longitudinal channel the mixing channel is the exit zone. The exit zone expands in such a way that it has a cross-sectional area that is larger than the cross-sectional area of ​​the longitudinal mixing channel. By way of example, the exit zone is an angled tooth 60 oriented in such a way that it extends in the outlet direction. The middle longitudinal mixing channel 50 and the slant 60 together form a longitudinal Venturi tube.

[0035] In the embodiment shown here are four air ports. However, those skilled in the art will recognize that the number of air ports may vary. In the embodiment shown here, the air ports 54 are arranged around a central longitudinal mixing channel. Accordingly, in use, the air is injected from the four sides into a stream of liquid passing through the elongated mixing channel.

[0036] A foam pipe 62 with at least one porous element 63 is positioned in the discharge nozzle 44 in such a way that the porous element is behind the elongated mixing channel 50. The foam pipe 62 is fitted down after the mixing pipe 18. Foam pipe it is narrowed in such a way that the outlet end has a smaller diameter than the inlet end. Alternatively, the foam pipe 62 may have a parallel tube. The foam pipe may have a porous element 63 attached to its one or both ends. The porous element may be a mesh, gauze, foam, foam or other suitable porous material and may have the same thickness or thickness before lower thickness. Accordingly, the user can adjust his selection of the porous element to the type and properties of the liquid.

[0037] The piston dome 30 is functionally attached to the main pump body, whereby it is held between the main pump body portion 29 and the liquid and air conduit 32. The piston dome has a liquid piston portion 35 which fits tightly within the liquid chamber 20, and moves up and down in the liquid chamber, changing the volume of the liquid chamber 20 in response to the movement of the dome 30 of the piston. The piston dome 30 is resiliently deformable in such a way that when it is pressed, the profile and material of the piston dome return to its rest position without the need for a spring. The liquid and air conduit 32 and the plunger dome 30 together form the air chamber 16, whereby, when the plunger cup 30 is pushed inward, the volume of the air chamber 16 is reduced.

[0038] The foam dispenser 10 also includes a transportation cap 66 that is press-fitted to the outer portion of the exit nozzle 44, as is best seen in figures 1 to 3. The transport attachment 66 includes a tongue 68 to pull to aid removal when it is ready for use. use.

[0039] In use, the piston dome 30 is pressed and air from the air chamber 16 is pushed through the air path 30 into the outer annular air channel 58 through the air ports 54, and into the central longitudinal mixing channel 50 in the mixing pipe 18, as shown in the figure 12. Mixing tube 18 is constructed so that air from air chamber 16 is pressurized as it enters the central longitudinal mixing channel 50 via air ports 54. As the piston dome 30 is released, the elastically deformable dome returns to its original shape, and the air chamber is recharged. As the piston dome 30 returns to its original shape, the suction effect draws air through the mixing tube and back into the air chamber 16 as shown in Figure 13. If there is still some liquid or foam in the mixing pipe 18, it will also be sucked back into the foaming assembly 14. With respect to the flow of liquid when the piston dome 30 is being pressed, the liquid pressure in the liquid chamber 20 increases in such a way that the liquid exit valve 24 opens and liquid flows into the central longitudinal mixing channel 50 of the mixing pipe 18, as shown in Figure 14. When the piston dome 30 returns to its original shape at the return stroke, the liquid chamber is recharged because a vacuum is created in the liquid chamber 20 and the liquid inlet valve 22 is opened, and liquid is sucked into the liquid chamber 20 as shown in figure 15.

[0040] As best seen in Figure 3, the foam dispenser 10 is composed of eight elements, namely, a piston dome 30, a liquid and air conduit 32, a main pump body part 29, a liquid container 12, a liquid outlet valve 24, a mixing pipe 18, the foam pipes 62 and the transport cap 66. The portion 29 of the main pump body and the liquid and air conduit 32 have integrally formed some of the other elements. By way of example, the air inlet valve 26, the liquid inlet valve 22 and the air path 30 are integrally formed in the liquid and air conduit 32. Similarly, the dip tube 34 is integrally formed in the portion 29 of the main pump body. The plunger dome 30 and the liquid and air conduit 32 together form the air chamber 16 and the liquid chamber 20, and are supported by a portion 29 of the main pump body. The appropriate volume of the air chamber 16 and the liquid chamber 20 depends on the position of the piston dome 30. During the activation stroke of the piston dome 30, the piston dome 30 moves from the rest position to the compression position, whereby, in response, both the volume of the air chamber 16 and the volume of the liquid chamber 20 are reduced. At the return stroke, the piston dome 30 moves from the compression position back to the rest position, in which both the volume of the air chamber 16 and the volume of the liquid chamber 20 return to their maximum volumes. both the volume of the air chamber 16 and the volume of the liquid chamber 20 are reduced. At the return stroke, the piston dome 30 moves from the compression position back to the rest position, in which both the volume of the air chamber 16 and the volume of the liquid chamber 20 return to their maximum volumes. both the volume of the air chamber 16 and the volume of the liquid chamber 20 are reduced. At the return stroke, the piston dome 30 moves from the compression position back to the rest position, in which both the volume of the air chamber 16 and the volume of the liquid chamber 20 return to their maximum volumes.

[0041] An alternative foam dispenser 70 is shown in figures 16 to 20, wherein the liquid container is an inverted liquid container 72. The foam generating unit 74 is similar to the foam generating unit 14 described above, and only those portions 74 for generating foam which differ from the foam generating unit 14 are described in detail. The main pump body part 76 has a connecting part 78 which is connected to the inverted liquid container 72. In the embodiment shown here, the connecting portion 78 is connected using a threaded connection, however any tight connection can be used.

The main pump body part 76 comprises a fluid channel 79 which is in fluid communication with the liquid chamber 20. The liquid channel inlet end 79 comprises a valve seat 80. The liquid inlet valve 22 is seated on the valve seat 80 and pushed to the closed position.

[0043] The air and liquid flow through the foam generating unit 74 when the piston cup 30 is depressed is shown in figure 19, and after releasing it is shown in figure 20. The air flow is shown by arrows 82, and the liquid flow at help with arrows 84.

[0044] The inverted liquid container 72 is a collapsible container. Thus, in this embodiment, the foam generating unit 74 does not have to include an air inlet and an air inlet valve that is in fluid communication with the liquid container.

[0045] Another alternative foam dispenser 90 is shown in figures 21 to 25, wherein the liquid container is an inverted foldable fluid bag 92 with the bag connector 94 attached thereto. The foam dispenser 90 is similar to both the foam dispenser and the foam dispenser 70 described above.

[0046] The foam dispenser 90 includes a foam generating unit 95, with a portion 96 of a main pump body that has a connector portion 98 that connects to the bag connector 94. The connecting portion 98 includes a valve seat 100 and the liquid inlet valve 22 is seated on the valve seat 100 and is pushed to the closed position. The bag connector 94 has a liquid channel 102, which when the bag connector 94 is connected to the connection portion 98 of the main pump body portion 96, is in fluid communication with the liquid chamber 20.

[0047] The air and liquid flow through the foam generating unit 90 when the piston cup 30 is depressed is shown in figure 24, and after releasing it is shown in figure 25. The air flow is shown by arrows 104 and the liquid flow at help arrows 106.

[0048] The mixing tube 18 or alternative embodiments of the mixing pipe may be used in other foam dispensers. Any foam dispenser that has an air chamber, a liquid chamber and means for generating pressure in the air chamber and liquid chamber can be adapted to use the mixing pipe shown here. An example of a prior art foam assembly for a dispenser is shown in Figure 26, an embodiment of the mixing pipe 112 is shown in Figures 27 to 29, and an alternative embodiment of the mixing pipe 130 is shown in Figures 30 to 33. The assembly 110 shown here prior art foam is a foam generating unit for a dispenser similar to that shown in US 6 082 586. The dispenser includes a pump that has an activation stroke, in which the pump moves from the rest position to the compression position, and a return stroke in which the pump moves from the compression position to the rest position. The volume of the air chamber and the liquid chamber are much smaller in the compression position.

[0049] Referring to Figures 27 to 29, the mixing chamber shown in US 6 082 586 has been modified by using a mixing pipe 112. In addition, because the mixing pipe 112 is more efficient than the prior art mixing chamber, the volume the air chamber can be reduced, generally maintaining the quality of the foam. rustirring 112 is similar to the above-described mixing tube 18 with a median longitudinal mixing channel 114 and air ports 116. In this embodiment, two air ports 116 are equally spaced, generally at the same distance from each other around the central longitudinal mixing channel 114. At the outlet end of the central longitudinal mixing channel 114 is an exit zone, which here is a slit 122. Mixing longitudinal channel 114 and the slant 122 together form a longitudinal Venturi tube.

[0050] The foam dispenser includes a foam generating unit 111, with an air chamber 118 and a liquid chamber 120. The air chamber 118 is in fluid communication with the middle longitudinal mixing channel 114 through the air ports 116. The liquid chamber 120 is in fluid communication with the central longitudinal mixing channel 114 at the inlet end of the elongated mixing channel. At the discharge end of the central elongate mixing channel 114 is the slant 122. Foam pipes, inlet, either first, 124 and outlet, or second, 126, are in the discharge nozzle 128 downstream of the mixing pipe 112. Each foam tube 124, 126 is attached to the foam. it is a porous element. Alternatively, there may be one foam tube with a porous element attached to each end thereof. Accordingly, the second foam tube has a porous element of the second foam tube attached thereto. Typically, the inlet porous element has larger openings than the outlet porous element. The internal diameter of the inlet pipe to the foam 124 is generally the same as the end of the muzzle exit 122. It has been observed that in the configuration shown in Figures 27 to 29 there is a risk that after actuation the dispenser can leak. Accordingly, an exhaust valve can be added or the air volume can be significantly increased below the air ports.

An alternative embodiment of a foam generating unit 131 and an alternative mixing tube 130 are shown in figures 30 to 33. Figure 30 shows a return stroke, and figure 31 shows an activation stroke. Similarly, Figure 32 also shows a return stroke, but is a section view 90 degrees from the view shown in Figure 30. Thus, and Figure 33 is an activation jump made at 90 degrees with respect to Figure 31.

The mixing tube 130 likewise serves for use in a modified foam dispenser which is similar to the foam dispenser shown in US 6 082 586. The mixing pipe 130 is similar to the mixing pipe 112 described above with the middle longitudinal mixing channel 132 and the exit zone, which in this document is a notch 134. In this embodiment, there are no air ports in the mixing pipe 130 per se, rather the liquid and air are mixed together before the mixing tube 130. The elongated mixing channel 132 and slant 134 together form the longitudinal venturi tube.

[0053] The foam dispenser includes a foam generating unit with an air chamber 118 and a liquid chamber 120. The liquid chamber 120 has an exhaust valve 136 that controls the liquid flow into the mixing chamber 138. The air chamber 118 has an outlet port 140 for the mixing chamber 138. A mixing chamber 138 is in front of the mixing pipe 130. The mixing chamber 138 is in fluid communication with the central elongate mixing channel 132 at the inlet end of the mixing pipe 130. The outlet end of the central elongate mixing channel 114 is the slant 122. Foam pipes, inlet 124 and outlet 126, are in the outlet nozzle 128 after the mixing pipe 130. The inside diameter of the inlet pipe to the foam 124 is generally the same as the end of the chamfer outlet 134.

[0054] Referring to Figure 34, the foam dispensing assembly of the vertical foam dispenser is designated 140. The foam generation assembly 140 includes an air chamber 142, a liquid chamber 144, a mixing chamber 146 and an outlet nozzle 148. This dispenser is described in detail in the patent US 5 443 569 issued to Uehir and others on August 22, 1995. This dispenser includes a pump having an activation stroke in which the pump moves from the rest position to the compression position, and a return stroke in which the pump moves from the compression position to the rest position. The volume of the air chamber and the volume of the liquid chamber are much smaller in the compression position.

[0055] This foam generating unit may be modified in a similar manner as described above. For example, it can be modified by inserting a mixing tube similar to those described above. Alternatively, the foam generating unit 151 may be modified as shown in figures 35 and 36. Figure 35 shows a return stroke, and figure 36 shows an activation stroke, where dotted lines 158 represent air flow and solid line 160 represents liquid flow. The foam generating assembly 151 is similar to the prior art foam assembly 140 shown in Figure 34, but with a modified mixing chamber and a reduced air volume in the air chamber. The mixing chamber has a central longitudinal mixing channel 150 with an exit zone, which here is a slant 152 at its exit. The connected central longitudinal mixing channel 150 and slant 152 constitute approximately one quarter of the volume of the mixing chamber 146 of the prior art. The improved mixing action allows reducing the volume of the air chamber 154 compared to the air chamber 142 by about 10 percent. The volume of the liquid chambers 146 and 156 are similar. It will be appreciated by those skilled in the art that the mixing tube described above may be formed separately from the mixing tube and then inserted into the mixing chamber in the foam generating assembly, or alternatively may be made as an integral part of the mixing chamber. [0056] It has been observed that the mixing tubes 18, 112 and 130 and the central longitudinal mixing channel 150 connect air and liquid in a more turbulent manner compared to the prior art. It was observed that the ratio of 0.75 ml liquid to 14, 2 ml of air gives a theoretical ratio of 1: 18.9, but in a prior art device similar to that shown in figure 26, the result observed is generally 1:12. In contrast, a ratio of 1.5 ml of liquid to 13.2 ml of air gives a theoretical ratio of 1: 8.8, with the observed result of 1: 8.1 in the embodiments shown in figures 30 to 33. Accordingly, the ratio of air volume to the volume of liquid can be reduced compared to the state of the art described herein, and therefore more liquid can be dispensed per dose, keeping the same size of package or dispenser, while also ensuring a commercially acceptable foam quality. The ratio of liquid volume to air volume can be between 1: 2 and 1:12, or in specific applications can be 1: 8 and 1: 9. but in a prior art device similar to that shown in Figure 26, the result observed is generally 1:12. In contrast, a ratio of 1.5 ml of liquid to 13.2 ml of air gives a theoretical ratio of 1: 8.8, with the observed result of 1: 8.1 in the embodiments shown in figures 30 to 33. Accordingly, the ratio of air volume to the volume of liquid can be reduced compared to the state of the art described herein, and therefore more liquid can be dispensed per dose, keeping the same size of package or dispenser, while also ensuring a commercially acceptable foam quality. The ratio of liquid volume to air volume can be between 1: 2 and 1:12, or in specific applications can be 1: 8 and 1: 9. but in a prior art device similar to that shown in Figure 26, the result observed is generally 1:12. In contrast, a ratio of 1.5 ml of liquid to 13.2 ml of air gives a theoretical ratio of 1: 8.8, with the observed result of 1: 8.1 in the embodiments shown in figures 30 to 33. Accordingly, the ratio of air volume to the volume of liquid can be reduced compared to the state of the art described herein, and therefore more liquid can be dispensed per dose, keeping the same size of package or dispenser, while also ensuring a commercially acceptable foam quality. The ratio of liquid volume to air volume can be between 1: 2 and 1:12, or in specific applications can be 1: 8 and 1: 9. the observed result is generally 1:12. In contrast, a ratio of 1.5 ml of liquid to 13.2 ml of air gives a theoretical ratio of 1: 8.8, with the observed result of 1: 8.1 in the embodiments shown in figures 30 to 33. Accordingly, the ratio of air volume to the volume of liquid can be reduced compared to the state of the art described herein, and therefore more liquid can be dispensed per dose, keeping the same size of package or dispenser, while also ensuring a commercially acceptable foam quality. The ratio of liquid volume to air volume can be between 1: 2 and 1:12, or in specific applications can be 1: 8 and 1: 9. the observed result is generally 1:12. In contrast, a ratio of 1.5 ml of liquid to 13.2 ml of air gives a theoretical ratio of 1: 8.8, with the observed result of 1: 8.1 in the embodiments shown in figures 30 to 33. Accordingly, the ratio of air volume to the volume of liquid can be reduced compared to the state of the art described herein, and therefore more liquid can be dispensed per dose, keeping the same size of package or dispenser, while also ensuring a commercially acceptable foam quality. The ratio of liquid volume to air volume can be between 1: 2 and 1:12, or in specific applications can be 1: 8 and 1: 9. 1. In accordance with the embodiments shown in Figures 30 to 33. Accordingly, the ratio of air volume to liquid volume can be reduced compared to the state of the art described herein, and therefore more liquid can be dispensed per dose, keeping the same size of package or dispenser, providing also at the same time commercially acceptable foam quality. The ratio of liquid volume to air volume can be between 1: 2 and 1:12, or in specific applications can be 1: 8 and 1: 9. 1. In accordance with the embodiments shown in Figures 30 to 33. Accordingly, the ratio of air volume to liquid volume can be reduced compared to the state of the art described herein, and therefore more liquid can be dispensed per dose, keeping the same size of package or dispenser, providing also at the same time commercially acceptable foam quality. The ratio of liquid volume to air volume can be between 1: 2 and 1:12, or in specific applications can be 1: 8 and 1: 9.

[0057] It should be noted that the foam dispenser embodiments illustrated herein may be used in conjunction with the dispenser housing, where the dispenser housing includes a push button assembly that engages the plunger dome by displacing the push button assembly and activates the piston dome activation stroke. In addition, the button can be activated manually or automatically, wherein the motion sensor is functionally connected to the push button assembly in such a way that motion of the motion sensor in a predetermined range will activate the push button assembly. An example of this is shown in Figures 37 and 38, which show the dispenser housing 170 used in conjunction with the foam dispenser 70 shown in Figures 16 to 20, in which Figure 37 shows the button 172 in the rest position, ready for an activation stroke, and figure 38 shows a button 172 pressing the dome 30 of the piston, at the return stroke. Those skilled in the art will recognize that other embodiments may similarly be placed in the dispenser housing. The dispenser housing 170 includes a button 172 that presses against the dome 30 of the piston assembly 74 to produce foam. The dispenser housing 170 includes a rear portion 174 and a front portion 176. The rear portion 174 is typically attached to a wall. The front portion 176 is attached to the rear portion 174. The button 172 is pivotably attached to the front portion 176. Embodiments of the foam dispensers described herein can be used with foaming liquids, and in particular with soaps, creams or other balms that are capable of being foamed. Alternatively, they can be used with foam-forming alcohol. Those skilled in the art will recognize that other embodiments may similarly be placed in the dispenser housing. The dispenser housing 170 includes a button 172 that presses against the dome 30 of the piston assembly 74 to produce foam. The dispenser housing 170 includes a rear portion 174 and a front portion 176. The rear portion 174 is typically attached to a wall. The front portion 176 is attached to the rear portion 174. The button 172 is pivotably attached to the front portion 176. Embodiments of the foam dispensers described herein can be used with foaming liquids, and in particular with soaps, creams or other balms that are capable of being foamed. Alternatively, they can be used with foam-forming alcohol. Those skilled in the art will recognize that other embodiments may similarly be placed in the dispenser housing. The dispenser housing 170 includes a button 172 that presses against the dome 30 of the piston assembly 74 to produce foam. The dispenser housing 170 includes a rear portion 174 and a front portion 176. The rear portion 174 is typically attached to a wall. The front portion 176 is attached to the rear portion 174. The button 172 is pivotably attached to the front portion 176. Embodiments of the foam dispensers described herein can be used with foaming liquids, and in particular with soaps, creams or other balms that are capable of being foamed. Alternatively, they can be used with foam-forming alcohol. The dispenser housing 170 includes a button 172 that presses against the dome 30 of the piston assembly 74 to produce foam. The dispenser housing 170 includes a rear portion 174 and a front portion 176. The rear portion 174 is typically attached to a wall. The front portion 176 is attached to the rear portion 174. The button 172 is pivotably attached to the front portion 176. Embodiments of the foam dispensers described herein can be used with foaming liquids, and in particular with soaps, creams or other balms that are capable of being foamed. Alternatively, they can be used with foam-forming alcohol. The dispenser housing 170 includes a button 172 that presses against the dome 30 of the piston assembly 74 to produce foam. The dispenser housing 170 includes a rear portion 174 and a front portion 176. The rear portion 174 is typically attached to a wall. The front portion 176 is attached to the rear portion 174. The button 172 is pivotably attached to the front portion 176. Embodiments of the foam dispensers described herein can be used with foaming liquids, and in particular with soaps, creams or other balms that are capable of being foamed. Alternatively, they can be used with foam-forming alcohol. The front portion 176 is attached to the rear portion 174. The button 172 is pivotably attached to the front portion 176. Embodiments of the foam dispensers described herein can be used with foaming liquids, and in particular with soaps, creams or other balms that are capable of being foamed. Alternatively, they can be used with foam-forming alcohol. The front portion 176 is attached to the rear portion 174. The button 172 is pivotably attached to the front portion 176. Embodiments of the foam dispensers described herein can be used with foaming liquids, and in particular with soaps, creams or other balms that are capable of being foamed. Alternatively, they can be used with foam-forming alcohol.

[0058] Broadly speaking, the systems described herein are directed to foam dispensers and an improved cartridge. As required, embodiments of the foam dispenser and an improved cartridge are disclosed herein. However, the disclosed embodiments are exemplary only, and it is understood that the foam dispenser and the improved cartridge can be implemented in many different and alternative examples. Figures are not made to scale, and some features can be highlighted or minimized to show details of specific elements, while related items can be removed to prevent obscuring of new aspects. Thus, the specific construction and functional details disclosed herein can not be construed as limiting, but only as a basis for the claims and as a representative basis for instructing specialists in the field regarding the various uses of the foam dispenser and the improved mixing chamber. For instructional purposes, not limiting, the illustrated embodiments are directed to foam dispensers.

[0059] As used herein, the terms "comprising" and "comprising" should be interpreted as including and open, and not exclusive. Specifically, when used in this specification, including claims, the terms "comprising" and "comprising" and variants thereof mean that certain features, steps or components are included. These terms can not be interpreted as excluding the presence of other features, steps or components.