HK1202483B - A foam dispenser - Google Patents

Abstract

A foam assembly connectable to a liquid container includes a main pump body, a resiliently deformable piston dome, an air chamber, a liquid chamber, a mixing zone and a porous member. The main pump body has an exit nozzle with the porous member therein. The air chamber and the liquid chamber are each defined by the piston dome and the main pump body. The liquid chamber has a liquid inlet valve and a liquid outlet valve. The mixing zone is in flow communication with the air chamber and the liquid chamber. The volume of the air chamber and the liquid chamber are each dependent on the position of piston dome and during an activation stroke the piston moves from the at rest position to the depressed position and responsively the volume of the air chamber and the volume of the liquid chamber are reduced.

Description

Foam dispenser

Background

The present disclosure relates to foam dispensers, and in particular to dispensers that may have a resiliently deformable domed piston and dispensers that may have an improved mixing chamber.

The present invention relates to a foam dispenser, and more particularly to a non-aerosol foam dispenser or an unpressurized foam dispenser. These types of foam dispensers have become widely popular in the past decade and are now in widespread use throughout the world. An advantage of foam dispensers over conventional liquid dispensers is that foam dispensers use much less liquid per use or shot than conventional liquid dispensers. For example, if the foam dispenser is used for hand hygiene as a soap dispenser or an alcohol foam dispenser, the liquid used for each hand cleaning event may be much less than that used by direct liquid dispensers.

However, there is always a possibility of reducing the production cost, either by reducing the number of parts or by simplifying the manufacturing process. There is also the potential to improve the quality of the foam or, in the alternative, to produce commercially acceptable foam in a reduced cost production facility.

Disclosure of Invention

A foam assembly connectable to a liquid container includes a main pump body, a piston dome, an air chamber, a liquid chamber, a mixing region, and a porous member. The main pump body has an outlet nozzle. The piston dome is attached to the main pump body such that the piston dome is an elastically deformable piston dome and has a rest position and a depressed position. The air chamber is defined by the piston dome and the main pump body. The liquid chamber is defined 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 flow communication with the air chamber and in flow communication with the liquid chamber. The porous member is located in the outlet nozzle downstream of the mixing zone. The volume of the air chamber and the volume of the liquid chamber depend on the position of the piston dome, and during the activation stroke, the piston moves from a rest position to a depressed position, with a corresponding decrease in the volume of the air chamber and the volume of the liquid chamber.

A foam dispenser includes a liquid container, a main pump body, a piston dome, an air chamber, a liquid chamber, a mixing region, and a porous member. The main pump body has an outlet nozzle. The piston dome is attached to the main pump body such that the piston dome is an elastically deformable piston dome and has a rest position and a depressed position. The air chamber is defined by the piston dome and the main pump body. The liquid chamber is defined 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 flow communication with the air chamber and in flow communication with the liquid chamber. The porous member is located in the outlet nozzle downstream of the mixing zone. The volume of the air chamber and the volume of the liquid chamber depend on the position of the piston dome, and during the activation stroke, the piston moves from a rest position to a depressed position, with a corresponding decrease in the volume of the air chamber and the volume of the liquid chamber.

The main pump body may include a main pump body portion and a liquid and air bore. The liquid inlet valve may be integrally formed in the liquid and air bore. The liquid and air apertures may also include an air path integrally formed therein, wherein the air path extends between the air plenum and the mixing zone.

The foam assembly may also include an air inlet valve in flow communication with the liquid container. The air inlet valve may be integrally formed in the liquid and air bore.

The mixing region may comprise an elongate mixing channel, and the mixing channel may have an upstream end and a downstream end, the liquid chamber being in flow communication with the upstream end of the mixing channel via a liquid outlet valve. The foam assembly may also include a ramp at the downstream end of the mixing channel such that the ramp expands in the downstream direction. The mixing channel may further comprise a plurality of air ports spacing the downstream end from the upstream end of the mixing channel. The foam assembly may further include a mixing tube, and the mixing channel and the chamfer may be formed in the mixing tube. In addition, the air port may be formed in the mixing tube. There may be a plurality of air ports. The plurality of air ports may be 4 air ports equally spaced around the mixing channel. The plurality of air ports may be two air ports equally spaced around the mixing channel.

The foam assembly may further include a foam tube, wherein the foam tube has a porous member attached to one end thereof. The foam tube may have a second porous member attached to the other end thereof. The foam assembly may further include a second foam tube, wherein the second foam tube has a porous member attached to one end thereof.

The liquid container may be an upright liquid container, an inverted bag or an upright bag.

The mixing region may comprise at least one air port upstream of the elongate mixing channel.

The foam dispenser may include a dispenser housing having a pushrod for engaging the piston dome.

A mixing tube for use in a foam assembly having an air chamber and a liquid chamber and means for pressurizing the air chamber and the liquid chamber includes an elongate mixing channel and an exit region. The elongate mixing channel has an upstream end and a downstream end. The outlet area is located at the downstream end of the mixing channel, whereby the outlet area bevel expands in the downstream direction.

The outlet area may be a ramp expanding in the downstream direction.

The elongate mixing channel and the outlet region may form an elongate venturi tube.

The mixing tube may include at least one air port in the elongate mixing channel, and the air port is in flow communication with the air chamber.

The air port may be a plurality of air ports spaced around the mixing channel.

A foam assembly connectable to a liquid container includes a pump, a mixing region, and a porous member. The pump has an air chamber and a liquid chamber. The pump has an activation stroke in which the pump moves from a rest position to a compressed position and a return stroke in which the pump moves from the compressed position to the rest position. The volume of the air chamber and the volume of the liquid chamber are both greatly reduced in the compressed position. The mixing zone is in flow communication with the air chamber and in flow communication with the liquid chamber. The mixing region has an elongate mixing channel with a cross-sectional area and an exit region downstream of the elongate mixing channel. The cross-sectional area of the outlet region is larger than the cross-sectional area of the mixing channel. The porous member is downstream of the mixing zone.

The outlet area may be a ramp expanding in the downstream direction.

The elongate mixing channel and the outlet region may together form an elongate venturi tube.

At least one air port may be formed in the elongate mixing channel and each air port is in flow communication with the air chamber. The at least one air port may be a plurality of air ports spaced around the elongate mixing channel.

The ratio of the volume of the liquid chamber to the volume of the air chamber may be between 1:2 and 1: 50.

The ratio of the volume of the liquid chamber to the volume of the air chamber may be between 1:8 and 1: 9.

Further features of the disclosure will be described or will become apparent in the course of the following detailed description.

Drawings

The foam dispenser and improved mixing chamber will now be described, by way of example only, with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view of an embodiment of a foam dispenser;

FIG. 2 is a cross-sectional view of the foam dispenser of FIG. 1;

FIG. 3 is an exploded perspective view of the foam dispenser of FIGS. 1 and 2;

FIG. 4 is a cross-sectional view of an assembled pump body of the foam dispenser including a main pump body portion and liquid and air holes;

FIG. 5 is an enlarged cross-sectional view of a portion of the assembled pump body including the main pump body portion and the liquid and air ports, showing the air inlet valve;

FIG. 6 is an enlarged cross-sectional view of a portion of the pump body including the main pump body portion and the liquid and air bore, showing the liquid outlet valve in a second closed position;

FIG. 7 is an enlarged cross-sectional view of a portion of the pump body including a main pump body portion and liquid and air bores similar to that shown in FIG. 6, but showing the liquid outlet valve in an open position;

FIG. 8 is an enlarged cross-sectional view of a portion of the pump body including not only the main pump body portion and liquid and air ports similar to that shown in FIG. 6, but also a mixing tube;

FIG. 9 is an enlarged perspective view of the mixing tube;

FIG. 10 is an enlarged cross-sectional view of the foam tube;

FIG. 11 is an enlarged cross-sectional view of a portion of the pump body including not only the main pump body portion and liquid and air ports similar to that shown in FIG. 8, but also including a foam tube;

FIG. 12 is an enlarged cross-sectional view of a portion of the pump body including a main pump body portion and liquid and air bores similar to that shown in FIG. 11 and illustrating air flow during an activation stroke.

FIG. 13 is an enlarged cross-sectional view of a portion of the pump body including a main pump body portion and liquid and air bores similar to that shown in FIG. 11 and illustrating air flow during a return stroke.

FIG. 14 is an enlarged cross-sectional view of a portion of the pump body including a main pump body portion and liquid and air bores similar to that shown in FIG. 11 and illustrating liquid flow during an activation stroke.

FIG. 15 is a cross-sectional view of a foam dispenser similar to that shown in FIG. 2 and showing liquid flow during the return stroke.

Fig. 16 is a perspective view of an alternative embodiment of a foam dispenser with an inverted cartridge (cartridge);

FIG. 17 is an exploded perspective view of the foaming assembly of the dispenser of FIG. 16;

FIG. 18 is an enlarged cross-sectional view of a portion of the inverted cartridge and foaming assembly of the dispenser of FIG. 16;

FIG. 19 is an enlarged cross-sectional view of a portion of the foaming assembly and inverted cartridge similar to that shown in FIG. 18 and showing air and liquid flow during an activation stroke;

FIG. 20 is an enlarged cross-sectional view of a portion of the foaming assembly and inverted cartridge similar to that shown in FIG. 18 and showing air and liquid flow during the return stroke;

FIG. 21 is a perspective view of another alternative embodiment of a foam dispenser having a pouch (pouch);

FIG. 22 is an exploded perspective view of the foaming assembly of the dispenser of FIG. 21;

FIG. 23 is an enlarged cross-sectional view of a portion of the inversion cartridge and foaming assembly of the dispenser of FIG. 21;

FIG. 24 is an enlarged cross-sectional view of the foaming assembly similar to that shown in FIG. 23 and showing air and liquid flow during an activation stroke;

FIG. 25 is an enlarged cross-sectional view of a portion of the foaming assembly and inverted cartridge similar to that shown in FIG. 23 and showing air and liquid flow during the return stroke;

FIG. 26 is a cross-sectional view of a prior art foaming assembly;

FIG. 27 is a cross-sectional view of an alternative foaming assembly including a mixing tube and showing air and liquid flow during an activation stroke;

FIG. 28 is a cross-sectional view of the alternative foaming assembly shown in FIG. 26 including a mixing tube and illustrating air and liquid flow during the return stroke;

FIG. 29 is a cross-sectional view of a portion of an alternative foaming assembly showing a mixing tube, but cut at 90 degrees to the views shown in FIGS. 26 and 28;

FIG. 30 is a cross-sectional view of an alternative embodiment of the dispensing assembly during a return stroke, wherein the foaming assembly is similar to that shown in FIGS. 27-30, but showing a different path for air to enter the mixing chamber;

FIG. 31 is a cross-sectional view of the foaming assembly of FIG. 30 during an activation stroke;

FIG. 32 is a cross-sectional view of the foaming assembly of FIG. 30, but taken at 90 degrees from the view of FIG. 30;

FIG. 33 is a cross-sectional view of the foaming assembly of FIG. 31, but taken at 90 degrees from the view of FIG. 30;

FIG. 34 is a cross-sectional view of another prior art foaming assembly;

FIG. 35 is a cross-sectional view of a modified version of the foaming assembly of FIG. 34 showing the air flow path and the liquid flow path on the return stroke;

FIG. 36 is a cross-sectional view similar to that shown in FIG. 35, but showing the air flow path and the liquid flow path in the activation stroke;

fig. 37 is a cross-sectional view of the foam dispenser of fig. 16-21 in a dispenser housing; and

fig. 38 is a cross-sectional view of the housing and foam dispenser of fig. 37, but showing a return stroke.

Detailed Description

Referring to fig. 1, 2 and 3, an embodiment of a foam dispenser is shown generally at 10. The dispenser 10 includes a liquid container 12 and a foaming component 14. For reference, upstream and downstream are determined during the activation stroke, and therefore upstream is where the liquid begins in the liquid container 12 and downstream is where the liquid ends and exits the foam dispenser 10 from the outlet nozzle 44. The activation stroke is when the pump or piston dome 30 is depressed and the return stroke is when the piston dome or pump returns to its rest position.

The pump has an activation stroke in which the pump moves from a rest position to a compressed position and a return stroke in which the pump moves from the compressed position to the rest position. The volume of the air chamber and the volume of the liquid chamber each substantially decrease in the compressed position. Foaming assembly 14 has an air chamber 16 in flow communication with mixing zone 19 and a liquid chamber 20 in flow communication with mixing zone 19. The liquid chamber 20 is in flow communication with the liquid container 12 and has a liquid inlet valve 22. A liquid outlet valve 24 is between the liquid chamber and the mixing zone 19.

In one embodiment, the foaming assembly 14 includes a main pump body 28 and a piston dome 30. As best shown in fig. 4, the main pump body 28 includes a liquid and air bore 32 press-fit into the main pump body portion 29. As shown in fig. 2, the liquid and air bore 32 and piston dome of the main pump body 28 together define the liquid chamber 20, and the liquid inlet valve 22 is integrally formed in the liquid chamber 20, the liquid chamber 20 including a main liquid chamber portion 33 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. A custom valve seat 36 is positioned at one end of the dip tube 34 that transitions into the liquid chamber 20. The liquid inlet valve 22 is seated on a custom valve seat 36 and is biased in the closed position. The liquid inlet valve 22 selectively controls the liquid entering the liquid chamber 20 and is responsive to a decrease in pressure in the liquid chamber. The liquid and air bore 32 and the piston dome 30 define the air chamber 16. An air path 38 is defined by the liquid and air holes 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 fig. 1 to 16 is a mixing tube 18.

In the embodiment shown herein, the liquid container is an upright liquid container 12. The liquid and air port 32 includes an air inlet valve 26, the air inlet valve 26 being a one-way valve that allows air to enter the liquid container 12. The air inlet valve 26 is deflected to bias it closed when the liquid and air bore 32 is press-fitted into the main pump body portion 29. When the pressure in the bottle reaches a predetermined pressure, the air inlet valve 26 is bent open so that the liquid container does not collapse. A mating cup 40 is formed in the main pump body portion 29, and a closure feature 42 formed in the air inlet valve 26 is sealingly secured in the mating cup until the pressure in the liquid container 12 exceeds a predetermined pressure.

As best shown in fig. 6 and 7, in one embodiment, the main pump body portion 29 has an outlet nozzle 44 formed therein. The liquid outlet valve 24 is press-fitted into a portion of the main pump body portion 29. Liquid outlet valve 24 is positioned at liquid outlet 46 of liquid chamber 20. Liquid outlet valve 24 acts like an umbrella valve such that liquid outlet valve 24 moves from a rest position as shown in fig. 6 to an open position as shown in fig. 7 in response to pressure in liquid chamber 20. A liquid outlet valve selectively controls the flow of liquid from the liquid chamber 20 into the mixing tube 18. Arrow 48 shows the flow path of the liquid when liquid outlet valve 24 is in the open position.

An embodiment of the mixing tube 18 is shown in fig. 8 and 9. The mixing tube 18 is press fit into 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 flow communication with the upstream end of the elongate mixing channel 50 through an internal annular liquid channel 52. The elongate mixing channels are relatively long and narrow, forming a channel from the upstream end to the downstream end. Air is delivered into the central elongate mixing channel 50 through at least one air port 54, and in the embodiment shown herein, air is delivered into the central elongate mixing channel 50 through a plurality of air ports 54. In this embodiment there are 4 air ports 54 equally spaced around the central elongate mixing channel 50. The mixing tube has an annular gap 56, the annular gap 56 creating an outer annular air passage 58 in situ. An air passage 59 connects the annular air passage 58 and the air port 54. Thus, air flows from the air chamber 16 through the liquid and air path 38 in the air bore 32 into the outer annular air passage 58, through the air ports 54 into the air passage 59, and into the central elongate mixing channel 50. An outlet region is provided at the downstream end of the central elongate mixing channel. The exit region expands such that the cross-sectional area of the exit region is greater than the cross-sectional area of the elongate mixing channel. By way of example, the exit area is a ramp 60, the ramp 60 being oriented such that it expands in the downstream direction. The central elongate mixing channel 50 and the chamfer 60 together form an elongate venturi tube.

In the embodiment shown herein, there are 4 air ports. However, it will be understood by those skilled in the art that the number of air ports may vary. In the embodiment shown herein, the air ports 54 are spaced around a central elongate mixing channel. Thus, in use, air is injected from 4 sides into the liquid flow through the elongate mixing channel.

A foam tube 62 having at least one porous member 63 is positioned in the outlet nozzle 44 such that the porous member is downstream of the elongate mixing channel 50. A foam tube 62 is press fit downstream of the mixing tube 18. The foam tube is tapered so that the downstream end is smaller in diameter than the upstream end. Alternatively, the foam tubes 62 may have parallel holes. The foam tube may have a porous member 63 attached to one or both ends thereof. The porous member may be a mesh, gauze, foam, sponge, or other suitable porous material, and may be of the same gauge or a larger gauge upstream of the smaller gauge. Thus, the user can customize the selection of their porous member according to the type and characteristics of the liquid.

The piston dome 30 is operatively attached to the main pump body whereby the piston dome 30 is retained between the main pump body portion 29 and the liquid and air bore 32. The piston dome has a liquid piston portion 35, the liquid piston portion 35 being sealingly mounted inside the liquid chamber 20 and sliding up and down the liquid chamber in response to movement of the piston dome 30 to change the volume of the liquid chamber 20. The piston dome 30 is resiliently deformable so that once it is depressed, the profile and material of the piston dome will return to its rest position without the need for a spring. The liquid and air holes 32 and the piston dome 30 together define the air chamber 16 such that, when the piston dome 30 is pushed inwardly, the volume of the air chamber 16 is reduced.

As best shown in fig. 1-3, the foam dispenser 10 further includes a shipping cap 66 press-fit onto the exterior of the outlet nozzle 44. The shipping cap 66 includes a pull tab 68 to assist in removal when ready for use.

As shown in fig. 12, in use, the piston dome 30 is compressed and air from the air chamber 16 is pushed through the air path 38 into the outer annular air passage 58, through the air port 54, and into the central elongate mixing passage 50 in the mixing tube 18. The mixing tube 18 is configured so that air from the air chamber 16 is put under pressure as it enters the central elongate mixing channel 50 through the air port 54. When the piston dome 30 is released, the elastically deformable dome returns to its original shape and the air chamber is refilled. As the piston dome 30 returns to its original shape, the suction action draws air through the mixing tube and back into the air chamber 16, as shown in fig. 13. If there is still any liquid or foam in the mixing tube, the liquid or foam will also be drawn back into the foaming component 14. With respect to liquid flow, as shown in fig. 14, as the piston dome 30 is compressed, the liquid pressure in the liquid chamber 20 increases so that the liquid outlet valve 24 opens and liquid flows into the central elongate mixing channel 50 of the mixing tube 18. As shown in fig. 15, when the piston dome 30 returns to its original shape in the return stroke, the liquid chamber is refilled because a vacuum is generated in the liquid chamber 20 and the liquid inlet valve 22 is opened and liquid is drawn into the liquid chamber 20.

As shown in fig. 3, the foam dispenser 10 is made up of 8 parts, namely: a piston dome 30, a liquid and air bore 32, a main pump body portion 29, a liquid container 12, a liquid outlet valve 24, a mixing tube 18, a foam tube 62, and a shipping cap 66. The main pump body portion 29 and the liquid and air bore 32 have some other features integrally formed therein. By way of example, the air inlet valve 26, the liquid inlet valve 22 and the air path 38 are integrally formed in the liquid and air bore 32. Similarly, a dip tube 34 is integrally formed in the main pump body portion 29. The piston dome 30 cooperates with the liquid and air bore 32 to form the air chamber 16 and the liquid chamber 20, and the piston dome 30 and the liquid and air bore 32 are supported by the main pump body portion 29. The respective volumes of the air chamber 16 and the liquid chamber 20 depend 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 depressed position, whereby both the volume of the air chamber 16 and the volume of the liquid chamber 20 are correspondingly reduced. In the return stroke, the piston dome 30 moves from the depressed position back to the rest position, wherein both the volume of the air chamber 16 and the volume of the liquid chamber 20 return to their maximum volumes.

An alternative foam dispenser 70 is shown in fig. 16 to 20, in which the liquid container is an inverted liquid container 72. The foaming component 74 is similar to the foaming component 14 described above, and only the different portions of the foaming component 74 and the foaming component 14 will be described in detail. The main pump body portion 76 has a connecting portion 78 that is connectable to the inverted liquid container 72. In the embodiment shown herein, the connection portion 78 is connected using a threaded connection, however, any leak-free connection may be used.

The main pump body portion 76 includes a liquid passage 79 in flow communication with the liquid chamber 20. The upstream end of the liquid passage 79 includes a valve seat 80. The liquid inlet valve 22 is fixed to the valve seat 80 and is biased in the closed position.

The flow of air and liquid through the foaming assembly 74 when the piston dome 30 is compressed is shown in fig. 19, and the flow of air and liquid through the foaming assembly 74 when the piston dome 30 is released is shown in fig. 20. Air flow is shown by arrows 82 and liquid flow is shown by arrows 84.

The inverted liquid container 72 is a removable container. Thus, in this embodiment, the foaming component 74 need not include an air inlet and an air inlet valve in flow communication with the liquid container.

Another alternative foam dispenser 90 is shown in fig. 21-25, wherein the liquid container is an inverted removable liquid bag 92, wherein a bag connector 94 is attached to the removable liquid bag 92. Foam dispenser 90 is similar to foam dispenser 10 and foam dispenser 70 described above.

The foam dispenser 90 includes a foaming assembly 95 having a main pump body portion 96, the main pump body portion 96 having a connector portion 98 connected to the bag connector 94. The connector portion 98 includes a valve seat 100, the liquid inlet valve 22 being secured to the valve seat 100 and biased in the closed position. The bag connector 94 has a fluid passage 102, the fluid passage 102 being in flow communication with the fluid chamber 20 when the bag connector 94 is connected to the connector portion 98 of the main pump body portion 96.

The flow of air and liquid through the foaming assembly 90 when the piston dome 30 is compressed is shown in fig. 24 and the flow of air and liquid through the foaming assembly 90 when the piston dome 30 is released is shown in fig. 25. Air flow is shown by arrows 104 and liquid flow is shown by arrows 106.

The mixing tube 18 or alternate embodiments of the mixing tube may be used in other foam dispensers. Any foam dispenser having an air chamber, a liquid chamber, and means for pressurizing the air chamber and the liquid chamber can be modified to incorporate the mixing tube described herein. An example of a prior art foam assembly for a dispenser is shown in fig. 26, an embodiment of a mixing tube 112 is shown in fig. 27-29, and an alternative embodiment of a mixing tube 130 is shown in fig. 30-33. The prior art foam assembly 110 shown herein is a foam assembly for a dispenser similar to that shown in U.S. patent 6,082,586. The dispenser includes a pump having an activation stroke in which the pump moves from a rest position to a compressed position and a return stroke in which the pump moves from the compressed position to the rest position. The volume of the air chamber and the volume of the liquid chamber are both greatly reduced in the compressed position.

Referring to fig. 27-29, the mixing chamber shown in U.S. patent 6,082,586 has been modified to include a mixing tube 112. Additionally, because the mixing tube 112 is more efficient than prior art mixing chambers, the volume of the air chamber may be reduced while substantially maintaining the quality of the foam. The mixing tube 112 is similar to the mixing tube 18 described above, having a central elongated mixing channel 114 and air ports 116. In this embodiment there are two air ports 116, the two air ports 116 being substantially equally spaced from each other around the central elongate mixing channel 114. At the downstream end of the central elongate mixing channel 114 there is an outlet region, here a chamfer 122. The mixing elongate channel 114 and the chamfer 122 together form an elongate venturi tube.

The foam dispenser includes a foaming assembly 111 having an air chamber 118 and a liquid chamber 120. The air chamber 118 is in flow communication with the central elongate mixing channel 114 through the air port 116. The liquid chamber 120 is in flow communication with the central elongate mixing channel 114 at the upstream end of the elongate mixing channel. At the downstream end of the central elongate mixing channel 114 is a chamfer 122. An upstream or first foam tube 124 and a downstream or second foam tube 126 are located in an outlet nozzle 128 downstream of the mixing tube 112. Each foam tube 124, 126 has a porous member attached thereto. Alternatively, there may be one foam tube with a porous member attached to each end thereof. Thus, the second foam tube 126 has a second foam tube porous member attached thereto. Typically, the upstream porous member has larger pores than the downstream porous member. The inner diameter of the upstream foam tube 124 is substantially the same as the downstream end of the chamfer 122. It has been noted that in the configurations shown in figures 27 to 29, the dispenser may be at risk of dripping after activation.

Thus, an outlet valve may be added or the volume of the air well below the air port may be increased.

An alternative embodiment of the foaming component 131 and alternative mixing tube 130 is shown in fig. 30 to 33. Fig. 30 shows the return stroke and fig. 31 shows the activation stroke. Similarly, fig. 32 also shows the return stroke, but fig. 32 is a cross-sectional view at 90 degrees from the view shown in fig. 30, and fig. 33 is the activation stroke at 90 degrees from fig. 31.

Mixing tube 130 is similarly used in a modified foam dispenser similar to that shown in U.S. patent 6,082,586. The mixing tube 130 is similar to the mixing tube 112 described above, having a central elongate mixing channel 132 and an exit region, herein a chamfer 134. In this embodiment, there is no air port in the mixing tube 130 itself, and the liquid and air are mixed together upstream of the mixing tube 130. The elongate mixing channel 132 and the chamfer 134 together form an elongate venturi tube.

The foam dispenser includes a foaming assembly having an air chamber 118 and a liquid chamber 120. The liquid chamber 120 has an outlet valve 136 that controls the flow of liquid into a mixing chamber 138. The air chamber 118 has an outlet 140 into the mixing chamber 138. The mixing chamber 138 is upstream of the mixing tube 130. The mixing chamber 138 is in flow communication with the central elongate mixing channel 132 at the upstream end of the mixing tube 130. At the downstream end of the central elongate mixing channel 114 is a ramp 122. The upstream foam tube 124 and the downstream foam tube 126 are located in an outlet nozzle 128 downstream of a mixing tube 130. The inner diameter of the upstream foam tube 124 is substantially the same as the downstream end of the chamfer 134.

Referring to fig. 34, the foaming assembly of the stand-up foam dispenser is generally shown at 140. Foaming assembly 140 includes an air chamber 142, a liquid chamber 144, a mixing chamber 146, and an outlet nozzle 148. The dispenser is described in detail in U.S. Pat. No. 5,443,569 to Uehira et al, 8, 22, 1995. The dispenser includes a pump having an activation stroke in which the pump moves from a rest position to a compressed position and a return stroke in which the pump moves from the compressed position to the rest position. The volume of the air chamber and the volume of the liquid chamber are both greatly reduced at the compression position.

The foam assembly may be modified in a similar manner as described above. For example, the foam assembly may be modified by inserting a mixing tube similar to that described above. Alternatively, the foam assembly 151 may be modified as shown in fig. 35 and 36. Fig. 35 shows the return stroke and fig. 36 shows the activation stroke, wherein the dashed line 158 shows the air flow and the solid line 160 shows the liquid flow. The foaming assembly 151 is similar to the prior art foaming assembly 140 shown in fig. 34, but with a modified mixing chamber and reduced air volume in the air chamber. The mixing chamber has a central elongate mixing channel 150 with an outlet region, here a chamfer 152 downstream of the central elongate mixing channel 150. The combined central elongate mixing channel 150 and ramp 152 has a volume of about one-fourth of the volume of the prior art mixing chamber 146. The improved mixing action allows the volume of the air chamber 154 to be reduced by about ten percent compared to the air chamber 142. The volumes 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 molded separately as a mixing tube and then inserted into a mixing chamber in the foam assembly, or alternatively, the mixing tube may be formed as an integral part of the mixing chamber.

It has been noted that the mixing tubes 18, 112 and 130 and the central elongate mixing channel 150 combine air and liquid in a more chaotic manner than the prior art. It has been noted that the ratio of 0.75ml of liquid to 14.2ml of air yields a theoretical ratio of 1:18.9, but the results observed in prior art devices similar to that shown in fig. 26 are approximately 1: 12. In contrast, the ratio of 1.5ml of liquid to 13.2ml of air yields a theoretical ratio of 1:8.8, with the results observed in the embodiments shown in fig. 30 to 33 being 1: 8.1. Thus, the air to liquid volume ratio can be reduced from the prior art shown herein, and thus more liquid can be dispensed per shot while maintaining the same package or dispenser size, while also providing commercially acceptable foam quality. The ratio of the volume of liquid to the volume of air may be between 1:2 and 1:12, or in a particular application may be 1:8 and 1: 9.

It should be understood that the embodiments of the foam dispenser illustrated herein may be used in conjunction with a dispenser housing that includes a push rod assembly that engages a piston dome by moving the push rod assembly such that the piston dome can perform an activation stroke. Further, the push bar may be manually activated or automatically activated, wherein the motion sensor is operatively connected to the push bar assembly such that movement within a predetermined range of the motion sensor will activate the push bar assembly. An example of such a foam dispenser is shown in fig. 37 and 38, and fig. 37 and 38 show a dispenser housing 170 for use in conjunction with the foam dispenser 70 shown in fig. 16 to 20, wherein fig. 37 shows the push rod 172 in a rest position ready for an activation stroke and fig. 38 shows the push rod 172 pushing against the piston dome 30 and in a return stroke. It will be appreciated by those skilled in the art that other embodiments may be similarly housed in the dispenser housing. Dispenser housing 170 includes a push rod 172, and push rod 172 pushes against piston dome 30 of foam assembly 74. The dispenser housing 170 includes a back 174 and a front 176. The back 174 will typically be attached to the wall. The front 176 may be attached to the back 174. The push rod 172 may be hingedly attached to the front portion 176. Embodiments of the foam dispenser described herein may be used with foamable liquids, particularly soaps, creams, or other lotions capable of foaming. Alternatively, embodiments of the foam dispenser described herein may be used with foamable ethanol.

In general, the systems described herein relate to foam dispensers and improved inserts. Embodiments of foam dispensers and improved inserts are described herein as desired. However, the disclosed embodiments are merely exemplary, and it should be understood that the foam dispenser and the improved insert may be embodied in many different and alternative forms. The figures are not to scale and some features may be exaggerated or minimized to show details of particular elements while related elements may be omitted to prevent obscuring novel aspects. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the foam dispenser and improved mixing chamber. The illustrated embodiment is directed to a foam dispenser for purposes of teaching and not limitation.

As used herein, the terms "comprises" and "comprising" are to be interpreted as inclusive and open-ended, and not exclusive. In particular, the terms "comprises" and "comprising" and variations thereof, when used in this specification including the claims, are intended to imply the inclusion of a particular feature, step or component. The terms are not to be interpreted to exclude the presence of other features, steps or components.

Claims (32)

1. A foam assembly connectable to a liquid container, comprising:

a main pump body having an outlet nozzle;

a piston dome attached to the main pump body, wherein the piston dome comprises an elastically deformable dome and a liquid piston portion, and has a rest position and a depressed position;

an air chamber defined by the piston dome and the main pump body;

a liquid chamber defined by the liquid piston portion and the main pump body and having a liquid inlet valve and a liquid outlet valve;

a mixing region in flow communication with the air chamber and in flow communication with the liquid chamber; and

a porous member located in the outlet nozzle downstream of the mixing zone; and

wherein the volume of the air chamber is dependent on the position of the piston dome and the volume of the liquid chamber is dependent on the position of the liquid piston portion of the piston dome, the piston dome moving from the rest position to the depressed position during an activation stroke, the volume of the air chamber and the volume of the liquid chamber decreasing accordingly.

2. The foam assembly of claim 1, wherein the main pump body includes a main pump body portion and a second pump body portion forming a liquid and air aperture.

3. The foam assembly of claim 2 wherein the liquid inlet valve is integrally formed in the second pump body portion.

4. The foam assembly according to claim 2, wherein the second pump body portion further includes an air pathway integrally formed therein, wherein the air pathway extends between the air chamber and the mixing region.

5. The foam assembly of any one of claims 1 to 4, further comprising an air inlet valve in flow communication with the liquid container.

6. The foam assembly of any one of claims 1 to 4 wherein the mixing region comprises an elongate mixing channel having an upstream end and a downstream end, the liquid chamber being in flow communication with the upstream end of the elongate mixing channel through the liquid outlet valve.

7. The foam assembly of claim 6 further comprising a chamfer at the downstream end of the elongate mixing channel, wherein the chamfer expands in the downstream direction.

8. The foam assembly of claim 7 wherein the elongate mixing channel includes at least one air port separating a downstream end of the elongate mixing channel from an upstream end of the elongate mixing channel.

9. The foam assembly of claim 8 further including a mixing tube and the elongate mixing channel, the chamfer and the air port are formed in the mixing tube.

10. The foam assembly of claim 8 or 9 wherein the at least one air port is 4 air ports equally spaced around the elongate mixing channel.

11. The foam assembly of claim 8 or 9 wherein the at least one air port is two air ports equally spaced around the elongate mixing channel.

12. The foam assembly of any of claims 1 to 4, further comprising a foam tube, wherein the foam tube has the porous member attached to one end thereof.

13. The foam assembly of claim 12 wherein the foam tube has a second porous member attached to another end thereof.

14. The foam assembly of claim 12 further comprising a second foam tube, wherein the second foam tube has a second foam tube porous member attached to one end thereof.

15. The foam assembly of any one of claims 1 to 4, wherein the liquid container is one of an upright liquid container, an inverted liquid container, and an inverted bag.

16. A foam dispenser comprising:

a liquid container;

a main pump body having an outlet nozzle;

a piston dome attached to the main pump body, wherein the piston dome comprises an elastically deformable dome and a liquid piston portion, and has a rest position and a depressed position;

an air chamber defined by the piston dome and the main pump body;

a liquid chamber defined by the liquid piston portion and the main pump body and having a liquid inlet valve and a liquid outlet valve;

a mixing region in flow communication with the air chamber and in flow communication with the liquid chamber; and

a porous member located in the outlet nozzle downstream of the mixing zone; and

wherein the volume of the air chamber is dependent on the position of the piston dome and the volume of the liquid chamber is dependent on the position of the liquid piston portion of the piston dome, the piston dome moving from the rest position to the depressed position during an activation stroke, the volume of the air chamber and the volume of the liquid chamber decreasing accordingly.

17. The foam dispenser of claim 16 wherein the main pump body includes a main pump body portion and a second pump body portion forming a liquid and air bore.

18. The foam dispenser of claim 17 wherein the liquid inlet valve is integrally formed in the second pump body portion.

19. The foam dispenser of claim 17 wherein the second pump body portion further includes an air path integrally formed therein, wherein the air path extends between the air chamber and the mixing region.

20. The foam dispenser of any one of claims 16 to 19 further comprising an air inlet valve in flow communication with the liquid container.

21. The foam dispenser of any one of claims 17 to 19 further including an air inlet valve in flow communication with the liquid container, wherein the air inlet valve is integrally formed in the second pump body portion.

22. The foam dispenser of any one of claims 16 to 19 wherein the mixing region comprises an elongate mixing channel having an upstream end and a downstream end, the liquid chamber being in flow communication with the upstream end of the elongate mixing channel through the liquid outlet valve.

23. The foam dispenser of claim 22 further including a chamfer at the downstream end of the elongate mixing channel, wherein the chamfer expands in the downstream direction.

24. The foam dispenser of claim 23 wherein the elongate mixing channel includes at least one air port spacing a downstream end of the elongate mixing channel from an upstream end of the elongate mixing channel.

25. The foam dispenser of claim 24 further including a mixing tube and the elongate mixing channel and the chamfer are formed in the mixing tube.

26. The foam dispenser of claim 24 or 25 wherein the at least one air port is 4 air ports equally spaced around the elongate mixing channel.

27. The foam dispenser of claim 24 or 25 wherein the at least one air port is two air ports equally spaced around the elongate mixing channel.

28. The foam dispenser of any of claims 16 to 19 further comprising a foam tube, wherein the foam tube has the porous member attached to one end thereof.

29. The foam dispenser of claim 28 wherein the foam tube has a second porous member attached to its other end.

30. The foam dispenser of claim 28 further comprising a second foam tube, wherein the second foam tube has a second foam tube porous member attached to one end thereof.

31. The foam dispenser of any one of claims 16 to 19 wherein the liquid container is one of an upright liquid container, an inverted liquid container, and an inverted bag.

32. The foam dispenser of claim 16 further comprising a dispenser housing including a pushrod for engaging the piston dome.