Patent Publication Number: US-2005115988-A1

Title: Multiple liquid foamer

Description:
BACKGROUND  
      The present invention generally relates to fluid dispensing systems, and more specifically, but not exclusively, concerns a foamer that is able to foam liquids from at least two sources.  
      Some chemicals when combined have a short shelf life due to the chemical reactions caused by combining the two component chemicals. This short shelf life prevents many formulations that could provide excellent performance, because by the time the product gets to market the potency of the combination is reduced or nonexistent. One situation in which this problem arises is with a two component epoxy. Another situation can occur with cleaning supplies or personal hygiene products. It is sometimes desirable to dispense liquids in the form of foam, due to a number of attractive attributes of foam. For example, when hand soap or other types of personal cleansers are dispensed as foam, the foamed cleanser can be easily spread to cover the desired body location.  
      Typically, foam is created by introducing air or some other type of gas into a stream of liquid. As should be appreciated, introducing the right amount of air into the liquid to create foam can be difficult, especially with manually operated foamers. For instance, some manual foamer designs utilize what is called a foamer wall to create the foam. The foamer wall is positioned to encircle the outlet nozzle in the device. As a cone shaped spray of liquid from the nozzle hits and deflects off the foamer wall, air is introduced into the liquid, thereby creating foam. However, such foamer designs do not adequately regulate the introduction of air into the liquid such that foam may not be created, or at best, the foam created may not be uniform. Regulating the introduction of air is especially a problematic if more than one liquid is being foamed. If air introduction is not properly regulated, the resulting dispensed liquid may be insufficiently foamed and/or a foamed inconsistently. Moreover, with the liquid striking the foamer wall in such a design, the foamer&#39;s exterior can become dirty.  
      Thus, needs remain for further contributions in this area of technology.  
     SUMMARY OF THE INVENTION  
      One aspect of the present invention concerns a multiple liquid foamer pump. The multiple liquid foamer includes a foamer pump that defines a pump chamber. The foamer pump includes a plunger received in the pump chamber to pump a gas. A first liquid pump is coupled to the plunger to pump a first liquid in unison with the plunger. A second liquid pump is coupled to the plunger to pump a second liquid in unison with the plunger. The foamer pump defines a mixed liquid passage that is fluidly coupled to the first liquid pump and the second liquid pump. The mixed liquid passage is constructed and arranged to mix the first liquid from the first liquid pump and the second liquid from the second liquid pump to form a mixed liquid. The foamer pump defines a gas passage in which the gas from the pump chamber is pumped. The gas passage intersects the mixed liquid passage to create foam with the mixed liquid and the gas.  
      Another aspect concerns an apparatus that includes a pump assembly that is constructed and arranged to couple to a container. The pump assembly includes a first liquid pump constructed and arranged to pump a first liquid from the container. A second liquid pump is disposed inside the first liquid pump to reduce the space occupied by the pump assembly in the container. The second liquid pump is constructed and arranged to pump a second liquid from the container. The pump assembly defines a mixed liquid passage that is coupled to the first liquid pump and the second liquid pump in which the first liquid and the second liquid are mixed to form a mixed liquid.  
      A further aspect concerns a multiple liquid foamer that includes means for manually pumping a first liquid and means for manually pumping a second liquid. The foamer further includes means for mixing the first liquid and the second liquid to form a mixed liquid. Further, the foamer includes means for manually pumping a gas into the mixed liquid in unison with the means for manually pumping the first liquid and the means for manually pumping the second liquid to create foam.  
      Further forms, objects, features, aspects, benefits, advantages, and embodiments of the present invention will become apparent from a detailed description and drawings provided herewith.  
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a cross sectional view, in full section, of a foamer, according to one embodiment of the present invention.  
       FIG. 2  is a cross sectional view, in full section, of the  FIG. 1  foamer during a dispensing stroke.  
       FIG. 3  is an enlarged cross sectional view of a plunger in the  FIG. 1  foamer during the dispensing stroke.  
       FIG. 4  is a cross sectional view, in full section, of a foamer, according to another embodiment of the present invention.  
       FIG. 5  is a cross sectional view, in full section, of the  FIG. 4  foamer during a dispensing stroke.  
       FIG. 6  is an enlarged cross sectional view of a plunger in the  FIG. 4  foamer during the dispensing stroke.  
       FIG. 7  is a perspective view of a piston assembly in the  FIG. 4  foamer.  
       FIG. 8  is a cross sectional view, in full section, of a foamer, according to a further embodiment of the present invention.  
       FIG. 9  is a cross sectional view, in full section, of the  FIG. 8  foamer during a dispensing stroke.  
       FIG. 10  is an enlarged cross sectional view of a plunger in the  FIG. 8  foamer during the dispensing stroke.  
       FIG. 11  is a cross sectional view, in full section, of a foamer, according to another embodiment of the present invention.  
       FIG. 12  is a cross sectional view, in full section, of the  FIG. 11  foamer during a dispensing stroke.  
       FIG. 13  is an enlarged cross sectional view of a plunger in the  FIG. 11  foamer during the dispensing stroke.  
       FIG. 14  is a cross sectional view, in full section, of an inverted foamer, according to a further embodiment of the present invention.  
       FIG. 15  is an enlarged cross sectional view of a plunger in the  FIG. 14  foamer during the dispensing stroke.  
       FIG. 16  is an enlarged cross sectional view of the  FIG. 15  plunger during a return stroke.  
    
    
     DESCRIPTION OF THE SELECTED EMBODIMENTS  
      For the purpose of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. Any alterations and further modifications in the described embodiments, and any further applications of the principles of the invention as described herein are contemplated as would normally occur to one skilled in the art to which the invention relates. A number embodiments of the invention are shown in great detail, although it will be apparent to those skilled in the art that some features that are not relevant to the present invention may not be shown for the sake of clarity.  
      A multiple liquid foamer  30  according to one embodiment of the present invention will now be described with reference to  FIGS. 1, 2  and  3 . Although the illustrated foamer  30  is a twin liquid foamer, that is configured to combine two separate liquids and foam the combined liquids, it is contemplated that in other embodiments the foamer  30  can be modified to foam more than two liquids. In the illustrated embodiment, the foamer  30  has a generally cylindrical shape. However, it should be appreciated that the foamer  30  in other embodiments can be shaped differently. Referring to  FIG. 1 , the multi-liquid foamer  30  includes a foamer pump  33  that is secured to a container  34 . The container  34  has a first compartment  37  that is configured to store a first liquid and a second compartment  38  that is configured to store a second liquid. In the illustrated embodiment, the first  37  and second  38  compartments are positioned in a stacked relationship. Nevertheless, it should be appreciated that the compartments  37 ,  38  can be oriented in a different manner. For instance, the compartments  37 ,  38  can be concentrically arranged such that the second compartment  38  is located inside the first compartment  37 , or vice versa. As shown, a divider wall  39  separates the first compartment  37  from the second compartment  38 , and a feed tube  41  for feeding the second fluid into the foamer pump  33  extends from the second compartment  38  into the first compartment  37 . Opposite the divider wall  39 , the container  34  has an end wall  44 . In one form, the end wall  44  is collapsible and/or moveable so that a vacuum (low pressure) is not formed inside the second compartment  38  as the second liquid is dispensed. For instance, the end wall  44  can include a follower piston that reduces the volume of the second compartment  38  as the second liquid is dispensed. The follower piston acts in a manner similar to those used in airless dispensing systems, such as in airless dispensing systems used to dispense toothpaste. As should be appreciated the container  34  can incorporate other types of mechanisms or structures for equalizing the pressure inside the container  34 . By way of a non-limiting example, the container  34  can include a venting structure in order to allow outside air to fill the second compartment  38  as the second liquid is removed.  
      The container  34  has a neck  46  onto which the foamer pump  33  is secured. In the embodiment shown in  FIG. 1 , the neck  46  is threaded so as to engage threading  47  in the foamer pump  33  such that the foamer pump  33  can be secured by being screwed onto the neck  46  of the container  34 . It is contemplated that in other embodiments the foamer pump  33  can be secured in other manners. At the end of the neck  46 , between the neck  46  and the threading  47  in the foamer pump  33 , a vent seal  48  is positioned to permit venting of the first compartment  37 , while at the same time prevent leakage of the first fluid from the first compartment  37 . In order to relieve the vacuum formed inside the first compartment  37  as the first fluid is dispensed, air from outside the container  34  is drawn between the neck  46  and the foamer pump  33 , through the vent seal  48  and into the first compartment  37 . It should be understood that the first compartment  37  as well as the rest of the container  34  can be vented in other manners.  
      As previously mentioned, the foamer pump  33  is threadedly secured to the container  34 . Referring to  FIGS. 1 and 2 , the foamer pump  33  has a pump body  50  that is threadedly secured to the neck  46  of the container  34 . The body  50  has an outer supply tube  52  that extends through the neck  46  and into the first compartment  37 . Extending inside the outer supply tube  52 , an inner supply tube  54  is coupled to one end of the feed tube  41  in order to receive the second fluid from the second compartment  38 . A first flow cavity  56  is formed between the outer supply tube  52  and the inner supply tube  54  as well as the feed tube  41 . The feed tube  41  along with the inner supply tube  54  define a second flow cavity  58  through which the second fluid is supplied to the foamer pump  33 . Inside the outer supply tube  52 , a first inlet valve  61  controls the flow of the first fluid into the foamer pump  33 . The first inlet valve  61  includes a first inlet valve member  63 , which in the illustrated embodiment is a circular-shaped flap, that covers one or more first inlet openings  64  formed in the outer supply tube  52 . A radially inner edge of the first inlet valve member  63  is sandwiched between an inlet engagement ridge  66  on the inner supply tube  54  and the outer supply tube  52 . The first inlet valve  61  is configured to seal one end of a first pump chamber  68 , which is formed between the outer  52  and inner  54  supply tubes, such that the first fluid is only able to flow into the first pump chamber  68 . Inside the inner supply tube  54 , the foamer pump  33  has a second inlet valve  71  that is configured to seal one end of a second pump chamber  72  in the inner supply tube  54 . In the illustrated embodiment, the second inlet valve  71  is in the form of a ball valve that is configured to allow the second fluid to flow into the second pump chamber  72 , but not back into the second compartment  38 .  
      Referring to  FIG. 3 , a liquid piston  75  is slidably received in both the first pump chamber  68  as well as the second pump chamber  72 . The liquid piston  75  includes an inner piston member  76  that is surrounded by an outer piston member  77 . The inner piston member  76  defines a second fluid outlet cavity  79  with one or more second fluid outlet openings  80  through which the second fluid flows during pumping. An inner outlet valve  82  selectively opens and closes the second fluid outlet openings  80  during pumping. According to the illustrated embodiment, the inner outlet valve  82  includes an inner sliding seal  83  that is received in a seal notch  84 , which is formed in the inner piston member  76  around the second fluid outlet openings  80 . The inner sliding seal  83  is able to slide within the seal notch  84  so as to selectively close and open the second fluid outlet openings  80 . As depicted, the inner sliding seal  83  seals between the inner piston member  76  and the inner supply tube  54 . At the end of the second pump chamber  72 , opposite the second inlet valve  71 , the inner supply tube  54  has a retainer notch  86  in which an inner retainer  87  is received. A spring  88  presses against the inner retainer  87  in order to bias the liquid piston  75  out of the second pump chamber  72 . During a pumping stroke, as the inner piston member  76  is pushed further inside the second pump chamber  72 , the friction between the inner sliding seal  83  and the inner supply tube  54  causes the inner sliding seal  83  to slide along the inner piston member  76  and uncover the second fluid outlet openings  80 . The spring  88  during the pumping stroke compresses, and once the foamer pump  33  is released, the spring  88  retracts the liquid piston  75 . As the inner piston member  76  slides out of the second pump chamber  72 , the friction between the inner sliding seal  83  and the inner supply tube  54 , cause the inner sliding seal  83  to close the second fluid outlet openings  80 . Once retracted, the inner retainer  87  ensures that the inner outlet valve  82  remains closed.  
      With continued reference to  FIG. 3 , a piston cap  90  engages one end of the outer piston member  77 , and the piston cap  90  is configured to seal against the inner supply tube  54 . As illustrated, the piston cap  90  defines one or more first fluid or outer outlet openings  92  through which the first fluid flows during pumping. An outer outlet valve  94  is configured to selectively open and close the outer outlet openings  92 . In the illustrated embodiment, the outer outlet valve  94  includes an outer sliding seal  96  that is slidably received around the piston cap  90 . The piston cap  90  includes an engagement portion  98  that is constructed and arranged to engage the outer piston member  77 . At the engagement portion  98 , the piston cap  90  has a retention ridge  99  that is configured to retain the outer sliding seal  96 . Opposite engagement portion  98 , the piston cap  90  has a disengaged portion  102  that is spaced away from the outer piston member  77  to form a flow cavity  103  through which the first fluid from the outer outlet opening  92  is able to flow. A portion of the liquid piston  75  is received inside a piston tube  107  of a valve plate  108 . As shown in  FIG. 3 , one end  109  of the piston tube  107  has a cap notch  110  in which the piston cap  90  is secured, and end  109  is positioned to retain the outer sliding seal  96 . The outer sliding seal  96  is able to slide between the end  109  of the piston tube  107  and the retention ridge  99  of the piston cap  90  so as to open and close the outer outlet openings  92 . Between the outer piston member  77  and the piston tube  107 , an outer flow channel  111  is formed through which the first fluid from the flow cavity  103  is able to flow. An outer retainer  112  that is secured to the body  50  surrounds the piston tube  107  and aids in retaining the liquid piston  75 .  
      Referring to again to  FIGS. 1 and 2 , the foamer pump  33  includes a spout  116  with a spout outlet chamber  117  from which the combined, foamed liquid is dispensed. The spout  116  has a connection ridge  118  that engages a spout connection indentation  120  in a plunger  123 . Proximal the spout  116 , the plunger  123  has one or more air inlet notches  125  for receiving air to foam the combined liquid. Although the present invention will be described as using air to foam the combined liquid, it should be appreciated that other types of gases can be used for foaming. The plunger  123  has an inner wall portion  127  that defines a foam chamber  128  through which the foamed liquid is dispensed. The plunger  123  further has an outer wall portion  130  that, along with the inner wall portion  127 , defines an air inlet cavity  131 . An intermediate wall portion  133  connects the inner wall  127  to the outer wall  130 , and the intermediate wall  133  has one or more air holes  134  through which air from the air inlet cavity  131  is able to pass. As shown, the plunger  123  is slidably received in a plunger opening  136  defined in a cover  138 . The cover  138  is attached to the body  50  via a cover engagement ridge  140  on the body  50  that is received in a body engagement notch  141  in the cover  138 . Together the plunger  123 , the body  50  and the cover  138  form an air pumping chamber  143 . The plunger  123  has a seal member  144  that is able to slide along a seal against the body  50 .  
      As illustrated in  FIG. 3 , the valve plate  108  has air inlet  145  and outlet  146  valves that control the inflow and outflow of air from the pumping chamber  143 . The air inlet valve  145  includes an air inlet seal member or flap  147  that selectively seals one or more air inlet holes  147  in the valve plate  108 . The inlet flap  147  is secured to the valve plate  108  through a retention member  151 . On the side opposite the retention member  151 , the valve plate  108  has a plunger engagement flange  153  that secures the valve plate  108  to a valve plate engagement flange  154  on the plunger  123 . The air outlet valve  146  includes an air outlet flap  156  that selectively seals one or more air outlet holes  157 . According to the illustrated embodiment, the outer radial edge of the air outlet flap  156  is secured between the valve plate engagement flange  154  and the valve plate  108 . During the compression stroke of the foamer pump  33 , the air inlet flap  147  closes the air inlet holes  148 , thereby increasing the pressure in the air pumping chamber  143 . As the pressure increases, the pressure of the gas in the air pumping chamber  143  causes the outlet flap  156  to open and allow the gas to pass through gas outlet holes  157 , as is shown by arrows G in  FIG. 3 . During the return or intake stroke of the foamer pump  33 , the air outlet valve  146  closes and the air inlet valve  145  opens so as to fill the air pumping chamber  143  with air.  
      Between the plunger  123  and the liquid piston  75 , the foamer pump  33  has an insert  160  that mixes the liquids and air to create the foam. In  FIG. 3 , the insert  160  has a diverter head  161 , which along with the liquid plunger  75  forms a second liquid passage  162  through which the second liquid flows during dispensing, as is shown by arrows L 2 . The insert  160  has a valve plate engagement flange  164  that rests against the piston tube  107  of the valve plate  108  so as to form a first liquid passage  166 . The first liquid passage  166  and the second liquid passage  162  meet together at a mixed liquid opening  169  defined in the insert  160 . Where the first  166  and second  162  liquid passages meet, the first and second liquids mix together to form a mixed liquid that flows through the mixed liquid opening  169 , as is depicted with arrows M in  FIG. 3 . The insert  160  has an inner diverter flange  170  and an outer diverter flange  172  that, along with an intermediate flange  173  extending from the plunger  123 , form a convoluted air passage  176  that creates turbulent air flow for foaming the mixed liquid. As shown, the intermediate flange  173  is positioned between the inner  170  and outer  172  diverter flanges to form a series of ninety degree (90°) turns for creating a turbulent air flow. At the end of the convoluted air passage  176 , the air or gas G blows transversely to the flow of the combined or mixed liquid M from mixed liquid opening  169  to form foamed liquid F. Specifically, the combined liquid M is impacted by the high velocity, radially flowing air, which blows at a right angle to the combined liquid. By blowing at right angles to the flow of the combined liquid, considerable turbulence is created that mixes the liquids with the air. The foamed liquid flows into a foam cavity  178  in the insert  160 , through a foam aperture  179  in the plunger  123  and into the foam chamber  128 . Inside the foam chamber  128 , the foamer pump  33  has a mesh member  182  ( FIGS. 1 and 2 ) with one or more mesh screens that refine the foam to a consistent form. As shown in  FIGS. 1 and 2 , the spout  116  has a discharge opening  184  from which the foam is dispensed.  
      Before dispensing the foam, the foamer pump  33  is primed by depressing the spout  116  in a dispensing or depressing direction D, as depicted in  FIG. 2 . As the spout  116  is depressed and the plunger  123  moves in direction D, the friction between the sliding seals  83 ,  96  and the supply tubes  52 ,  54  causes the outlet valves  82 ,  94  to open. While the plunger  123  moves in direction D, the spring  88  is also compressed. Once the spout  116  is released, the spring  88  expands to cause the plunger  123  to extend and return to its initial configuration, as depicted in  FIG. 1 . During the extension or return stroke, the friction between the sliding seals  83 ,  96  and the supply tubes  52 ,  54  causes the sliding seals  83 ,  96  to cover the fluid outlet openings  80 ,  92 , thereby closing the outlet valves  82 ,  94 . As the plunger  123  is retracted, a vacuum (low pressure) is formed in the first  68  and second  72  pump chambers, which opens the inlet valves  61 ,  71  to allow the first and second fluids to respectively fill the first  68  and second  72  pump chambers. At the same time, air is drawn into the air pumping chamber  143  via the air inlet valve  145 . With the pump chambers  68 ,  72  filled with liquid, the foamer pump  33  is primed. The next time the spout  116  is depressed, the inlet valves  61 ,  71  for the pump chambers  68 ,  72  remain closed while the plunger  123  extends into the pump chambers  68 ,  72 . During this compression stroke, the friction between the sliding seals  83 ,  96  and the supply tubes  52 ,  54  causes the outlet valves  82 ,  94  to open. As shown by arrows L 1  in  FIG. 3 , the first liquid travels through the outer outlet opening  92 , into flow cavity  103  and then into the outer flow channel  111 . The second liquid, as depicted by arrows L 2 , flows through the second fluid outlet openings  80 , into the second fluid outlet cavity  79 , and then into the second liquid passage  162 . At the mixed liquid openings  169 , the first and second liquid streams combine to form a mixed fluid flow, as indicated by arrows M in  FIG. 3 . At the same time, the air in the air pumping chamber  143  is pressurized to cause the air outlet valve  146  to open. From the air outlet valve  146 , the air travels within the convoluted passage  176 , as depicted by arrows G. The now turbulent air in the convoluted passage  176  blows into the mixed fluid M from the mixed liquid openings  169  so as to form foam. As shown by arrows F, the foam travels from the foam cavity  178  into the foam chamber  128  via the foam aperture  179 . In the foam chamber  128 , the foam flows through the mesh member  182  to increase foam uniformity, and then the foam is dispensed out the discharge opening  184 . The spout  116  can be pressed again in order to dispense more foam.  
      As should be appreciated, with the inner supply tube  54  positioned inside the outer supply tube  52 , the volume of the foamer pump  33  occupying the container  34  is reduced, thereby allowing more fluid to be stored inside a given sized container  34 . Furthermore, the above-described foamer  30  minimizes the stroke length needed to pump the foam; while at the same time provides a compact configuration. As should be appreciated, by regulating the amount of air and liquid combined in a single stroke, the foamer  30  allows consistent manual dispensing of foam with a consistent quality and uniformity.  
      A multiple liquid foamer  190  according to another embodiment of the present invention will now be described with reference to  FIGS. 4, 5 ,  6  and  7 . The illustrated multiple liquid foamer  190  shares a number of components that are common with the previously described embodiment, and for the sake of brevity as well as clarity, these common components will not be described in great detail. Referring to  FIGS. 4 and 5 , the multiple liquid foamer  190  includes a foamer pump  192  that is threadedly mounted onto a container  194 . Inside, the container  194  has a first bladder  195  for storing a first liquid and a second bladder  196  for storing a second liquid. Both bladders  195 ,  196  are deformable so that the bladders  195 ,  196  are able to shrink as liquid is removed. Vent seal  48  on the neck  46  of the container  194  allows air to fill the container  194  as the liquid is dispensed from the bladders  195 ,  196 . Each bladder  195 ,  196  has a connector  198  that connects the bladders  195 ,  196  to the foamer pump  192 .  
      With reference to  FIGS. 4 and 5 , the foamer pump  192  includes side-by-side located first  201  and second  202  pump assemblies for pumping the first and second liquids from the first  195  and second  196  bladders, respectively. As shown, the first pump assembly  201  is coupled to the connector  198  of the first bladder  195 , and the second pump assembly  202  is coupled to the connector  198  of the second bladder  196 . Each pump assembly  201 ,  202  includes a pump housing or tube  204  that defines a pump cavity  205  and an inlet valve  207  that controls the inflow of liquid into the pump cavity  205 . In the illustrated embodiment, the inlet valve  207  includes a ball-type check valve. As illustrated, the pair of pump tubes  204  extend from a body  50   a  of the foamer pump  192  that is threaded onto the container  194 . Each pump assembly  201 ,  202  further has a piston  209  that is configured to draw liquid into and pump liquid from the pump cavity  205 . As depicted in  FIGS. 6 and 7 , each piston  209  has a piston cavity  210  with an outlet opening  211  in which the liquid from the pump cavity  205  is received. The pistons  209  individually have an outlet valve  213  that controls the flow of liquid through the outlet opening  211 . In the illustrated embodiment, the outlet valve  213  includes a sliding seal  214  that is slidably received in a slide notch  216  defined around the piston  209 . In one form, the sliding seal  214  is generally ring-shaped. The slide notch  216  acts as a slide stop to control the position of the sliding seal  214 . At the end of each of the piston cavities  210 , a retainer  219  is secured through which the pistons  209  slide. When the pistons  209  are fully retracted, the retainer  219  ensures that the sliding seals  214  are seated so as to seal the outlet openings  211 . Spring  88  presses against the retainer  219  to retract the pistons  209 .  
      As illustrated in  FIG. 7 , the pistons  209  are secured to a valve plate  221 . As shown, the valve plate  221  has a liquid diverter member  222  received in each piston cavity  210  that, along with the piston  209 , defines a flow passage  224  into which liquid from the piston cavity  210  flows. A connector ring  225  connects the two pistons  209  together. Inside the connector ring  225 , between the pistons  209 , a mixer insert  227  is positioned for mixing the first and second liquids from the flow passages from the first  201  and second  202  pump assemblies, respectively. With reference to  FIG. 6 , the mixer insert  227  defines a spring cavity  228  in which one end of the spring  88  is received. The mixer insert  227  has a mixer flange  230  that is biased by the spring  88  against a piston flange  231  such that the connector ring  225  of the pistons  209  is pressed against the valve plate  221 . Referring again to  FIG. 7 , the mixer insert  227  defines a series of circumferentially extending mixer channels  233  as well as longitudinally extending connector channels  234  that connect the mixer channels  233  together. As shown, successive connector channels  234  are offset radially from one another so that the liquids must first travel through the mixer channels  233  in order to promote mixing of the fluids. Extending around the mixer insert  227 , the valve plate  221  has an inner diverter flange  236  that along with the mixer insert  227  defines a mixed liquid discharge passage  237  from which the mixed liquid is discharged. As will be further described below, the valve plate  221  has an outer diverter flange  239  for directing air flow that surrounds the inner diverter flange  236 .  
      Referring again to  FIGS. 4 and 5 , the foamer pump  192  includes a spout  116  for discharging the foam and a plunger  123   a  that is connected to the spout  116 . The plunger  123   a  is slidably received in cover  192 , which is coupled to the body  50   a . The plunger  123   a  has one or more air inlet notches  125  for receiving air or some other type of gas. Plunger  123   a  further includes inner wall portion  127  that defines foam chamber  128  and outer wall portion  130 , which surrounds the inner wall portion  127 . An intermediate wall portion  133   a  extends between the inner wall portion  127  and the outer wall portion  130 , and the intermediate wall portion  133   a  has one or more air holes  134  through which air is drawn during operation of the foamer pump  192 . Inside the foamer pump  192 , the plunger  123   a  along with the valve plate  221  and the body  50   a  define an air pump chamber  143   a . Seal member  144  on the plunger  123   a  seals the air pump chamber  143   a  by sealing against the pump body  50   a.    
      As depicted in  FIGS. 6 and 7 , the valve plate  221  has air inlet  145  and outlet  146  valves that control the inflow and outflow of air from the pumping chamber  143   a . The air inlet valve  145  includes an air inlet seal member or flap  147  that selectively seals one or more air inlet holes  148  in the valve plate  108 . The inlet flap  147  is secured to the valve plate  221  through retention member  151 . On the side opposite the retention member  151 , the valve plate  221  has a plunger engagement flange  153  that secures the valve plate  221  to valve plate engagement flange  154  on the plunger  123   a . The air outlet valve  146  includes an air outlet flap  156  that selectively seals one or more air outlet holes  157 . According to the illustrated embodiment, the outer radial edge of the air outlet flap  156  is secured between the valve plate engagement flange  154  and the valve plate  221 . During a compression stroke of the foamer pump  192 , the air inlet flap  147  closes the air inlet holes  148 , thereby increasing the pressure in the air pumping chamber  143   a . As the pressure increases, the pressure of the gas in the air pumping chamber  143   a  causes the outlet flap  156  to open and allow the air to pass through air outlet holes  157 , as is shown by arrows G in  FIG. 6 . During the return stroke of the foamer pump  192 , the air outlet valve  146  closes and the air inlet valve  145  opens to fill the air pumping chamber  143   a  with gas.  
      As previously mentioned the outer diverter flange  239  on the valve plate  221  assists in directing the air flow within the foamer pump  192 . The diverter flange  239  along with the plunger  123   a  form a convoluted air passage  176   a  that has a series of turns for creating a turbulent air flow. The turbulent air flow aids in improving the quality of the foam dispensed from the foamer pump  192 . As depicted in  FIG. 6 , the convoluted air passage  176   a  and the mixed liquid discharge passage  237  transversely intersect so that the mixed liquid stream M combines with the gas stream G to form foam, as indicated by arrows F in  FIG. 6 . Specifically, the convoluted air passage  176   a  in the illustrated embodiment intersects the mixed liquid discharge passage  237  in a perpendicular manner so as to create turbulent air flow for foaming the combined liquid. The foam then flows through foam aperture  179  in the plunger  123   a , through mesh member  182  in the spout  116  and out the spout  116 .  
      To prime the foamer pump  192 , the spout  116  in a depressed direction D, as depicted in  FIG. 5 , and released so that the spring  88  extends the spout  116  to its initial position, as shown in  FIG. 4 . As the spout  116  returns to the initial position, the pistons  209  in the first  201  and second  202  pump assemblies draw the first and second liquids from the first  195  and second  196  bladders, respectively. During this intake or return stroke, the friction between the sliding seals  214  and the pump tubes  204  cause the sliding seals  214  to cover and seal the outlet openings  211  in the pistons  209 . As the plunger  123   a  is retracted, a vacuum (low pressure) is formed in the pump cavities  205  that draws the first and second liquids, thereby priming the foamer pump  192 . At the same time, air is drawn into the air pumping chamber  143   a  via the air inlet valve  145 .  
      After priming the foamer pump  192 , if the spout  116  is depressed again, the inlet valves  207  for the pump cavities  205  remain closed while the plunger  123   a  extends back into the pump cavities  205 . During this compression stroke, the friction between the sliding seals  214  and the pump tubes  204  cause the outlet valves  213  to open. As shown by arrows L 1  and L 2  in  FIG. 6 , the first and second liquids travel through the outer outlet openings  211  and into the piston cavities  210  of the first  201  and second  202  pump assemblies, respectively. Both liquids flow through their respective flow passages  224  and are mixed together in the mixer insert  227 . At the same time, the air in the air pumping chamber  143   a  is compressed to cause the air outlet valve  146  to open. From the air outlet valve  146 , the air travels within the convoluted passage  176   a , as depicted by arrows G, so as to become turbulent. The now turbulent air blows into the mixed fluid M from the mixed liquid discharge passage  237  so as to create foam. As shown by arrows F, the foam travels into the foam chamber  128  via the foam aperture  179 . In the foam chamber  128 , the foam flows through the mesh member  182  to refine the foam, and then the foam is dispensed out the spout  116 .  
      A multiple liquid foamer  245  according to a further embodiment of the present invention is illustrated in  FIGS. 8, 9  and  10 . As shown, the multiple liquid foamer  245  includes a foamer pump  247  that is secured to a container  248 . Inside, the container  248  includes a bladder  250  with connector  198  that couples the bladder  250  to the foamer pump  247 . The bladder  250  is configured to supply a first liquid to the foamer pump  247 , and a second liquid is stored in the container  248  around the bladder  250 . To supply the second liquid to the foamer pump  247 , the container  248  has a supply tube  252  that is connected to the foamer pump  247 .  
      Referring to  FIGS. 8 and 9 , the foamer pump  247  includes side-by-side located first  257  and second  258  pump assemblies for pumping the first and second liquids, respectively. As shown, the first pump assembly  257  is coupled to the connector  198  of the bladder  250 , and the second pump assembly  258  is coupled to the supply tube  252 . Each pump assembly  257 ,  258  includes a pump housing or tube  260  that defines a pump cavity  205  and an inlet valve  207  that controls the inflow of fluid into the pump cavity  205 . In the illustrated embodiment, the inlet valve  207  includes a ball-type check valve. As illustrated, the pair of pump tubes  260  extend from a body  50   b  of the foamer pump  192 , and the pump tubes  260  are integrally formed with the body  50   b  in the illustrated embodiment. Each pump assembly  257 ,  258  further has a piston  209  that is configured to draw liquid into and pump liquid from the pump cavity  205 . As depicted in  FIG. 10 , each piston  209  has a piston cavity  210  with one or more outlet openings  211  in which the liquid from the pump cavity  205  is received. The pistons  209  individually have an outlet valve  213  that controls the flow of liquid through the outlet opening  211 . In the illustrated embodiment, the outlet valve  213  includes a sliding seal  214  that is slidably received in a slide notch  216 , which is defined around the piston  209 . In one form, the sliding seal  214  is generally ring-shaped, but in other embodiments of the present invention, the sliding seal  214  have a different shape. The slide notch  216  acts as a slide stop to control the position of the sliding seal  214 . At the end of both piston cavities  210 , a retainer  219  is secured, and the pistons  209  slide through the retainer  219 . When the pistons  209  are fully retracted, the retainer  219  ensures that the sliding seals  214  are seated so as to seal the outlet openings  211 . Spring  88  presses against the retainer  219  for retracting the pistons  209  to an initial, extended state.  
      As illustrated in  FIG. 10 , the pistons  209  are coupled to a piston insert  262 . As shown, the piston insert  262  has a liquid diverter member  222  received in each piston cavity  210  that, along with the piston  209 , defines flow passage  224  into which liquid from the piston cavity  210  flows. Connector ring  225  connects the two pistons  209  together. Inside the connector ring  225 , between the pistons  209 , a mixer insert  264  is positioned for mixing the first and second liquids from the flow passages  224  from the first  257  and second  258  pump assemblies, respectively. The mixer insert  264  is similar to the mixer insert  227  described above with reference to  FIG. 7 , with the exception that the mixer insert  264  in  FIG. 10  includes a spring engagement flange  265  against which the spring  88  rests. The mixer insert  264  has a mixer flange  230  that is biased by the spring  88  against a piston flange  231  of the connector ring  225  such that the mixer insert  264  is pressed against the valve plate  221 . Like mixer insert  227  illustrated in  FIG. 7 , the mixer insert  264  of  FIG. 10  in one embodiment defines a series of radially extending mixer channels as well as longitudinally extending connector channels that connect the mixer channels together to promote mixing of the liquids. Extending around the mixer insert  264 , the piston insert  262  has an inner diverter flange  266  that along with the mixer insert  264  defines a mixed liquid discharge passage  237  from which the mixed liquid is discharged.  
      As depicted in  FIGS. 8 and 9 , the foamer pump  247  includes a spout  116  for discharging the foam and a plunger  123   b  that is connected to the spout  116 . The plunger  123   b  is slidably received in a cover  268  that is threadedly secured to the container  248 . The cover  268  includes an engagement member  269  that secures the body  50   b  to the cover  268 . In the illustrated embodiment, the engagement member  269  includes a pair of resilient ribs that secure the cover  268  to the body  50   b . It should be appreciated that the cover  268  and body  50   b  can be secured in other manners. The plunger  123   b  has one or more air inlet notches  125  for receiving air or some other type of gas. Plunger  123   b  further includes inner wall portion  270  that defines foam chamber  271  and outer wall portion  272 , which surrounds the inner wall portion  271 . An intermediate wall portion  273  extends between the inner wall portion  271  and the outer wall portion  272 , and the intermediate wall portion  273  has one or more air holes  274  through which air is drawn during operation of the foamer pump  247 . To control the air flow into the foamer pump  247 , the foamer pump  247  has a valve plate  277 . Inside the foamer pump  247 , the plunger  123   b  along with the valve plate  277  and the body  50   b  define an air pump chamber  143   b . Seal member  144  on the plunger  123   b  seals the air pump chamber  143   b  by sealing against the pump body  50   b.    
      The valve plate  277  in  FIG. 10  is generally cylindrical in shape. However, it is contemplated that the valve plate  277  can have a different overall shape in other embodiments. As shown, the valve plate  277  has an air inlet valve  279  and an air outlet valve  280  that control the inflow and outflow of air from the pumping chamber  143   b . The air inlet valve  279  includes an air inlet seal member or flap  283  that selectively seals an air inlet hole  285  in the valve plate  221 . The inlet flap  283  is secured to the valve plate  277  through retention member  151 . On the side opposite the retention member  151 , the valve plate  277  has a plunger engagement flange  153  that secures the valve plate  277  to a valve plate engagement flange  154  on the plunger  123   b . The air outlet valve  280  includes an air outlet flap  287  that extends inside an outlet flap groove  288  in the plunger  123   b . Normally, the air outlet flap  287  seals against the valve plate engagement flange  153 . During the compression stroke of the foamer pump  247 , the pressure formed in the air pump chamber  143   b  causes the air outlet flap  287  to deflect away from the valve plate engagement flange  153 , thereby allowing air to flow around the air outlet flap  287  in the outlet flap groove  288 . The abrupt turn of the air flow in the outlet flap groove  288  creates turbulence in the air flow. During the return stroke of the foamer pump  247 , the air outlet flap  287  closes and the air inlet valve  279  opens to fill the air pumping chamber  143   b  with air. An outlet valve engagement flange  290  extends from the plunger  123   b  to secure the air outlet flap  287  against the piston insert  262 , and in part, defines the outlet flap groove  288 . The valve engagement flange  290  defines an air flow notch  291  through which air flows during the compression stroke.  
      As shown, a convoluted passage  176   b  is defined between the inner diverter flange  266  of the piston insert  262  and valve engagement flange  290 . Air is discharged from the air flow notch  291  via the convoluted passage  176   b . The convoluted air passage  176   b  has a series of ninety degree (90°) turns for creating a turbulent air flow. As previously mentioned, the turbulent air flow aids in improving the quality of the foam dispensed from the foamer pump  247 . To prime the foamer pump  247 , the spout  116  is pressed and released, thereby drawing liquid into the first  257  and second  258  pump assemblies. When the spout  116  is pressed again after priming, the liquids travel through the piston cavities  210 , and the mixed liquid M is discharge via the mixed liquid discharge passage  237 . With reference to  FIG. 10 , the convoluted air passage  176   b  and the mixed liquid discharge passage  237  transversely intersect so that the mixed liquid stream M combines with the gas stream G to form foam, as indicated by arrows F in  FIG. 6 . The foam then flows through foam aperture  293  in the plunger  123   b , through mesh member  182  in the spout  116  and out of the spout  116 .  
      A multiple liquid foamer  300  according to a further embodiment of the present invention is illustrated in  FIGS. 11, 12  and  13 . As should be appreciated, the foamer  300  illustrated in  FIGS. 11, 12  and  13  has a number of features that are similar to the foamer  245  illustrated in  FIGS. 8, 9  and  10 . For the sake of brevity and clarity, these common features will not be described in detail below, since these features were already described above. For example, like the previously described embodiment, the foamer  300  includes a container  248  with a bladder  250  as well as a connector  198  and a supply tube  252 . A foamer pump  302  is threadedly secured to the container  248  with a cover  268 , and the foamer pump  302  includes a spout  116  that extends from the cover  268 . Cover engagement members  269  on pump body  50   c  secure the pump body  50   c  to the cover  268 . Vent seal  303 , which is disposed between the container  248  and the body  50   c , permits air flow into the container  248 , but at the same time, minimizes liquid leakage from the container  248 . Plunger  123   c , which is connected to the spout  116 , has a seal member  144  that is slidably received in the body  50   c . The plunger  123   c  and the body  50   c  define an air pumping chamber  143   c  into which air from an air inlet notch  125  in the plunger  123   c  is drawn.  
      Like before, the foamer pump  302  has first  305  and second  306  pump assemblies for pumping the first liquid and the second liquid, respectively. Each pump assembly  305 ,  306  includes a pump tube  307  with an inlet valve  207  and a piston  309  slidably received in the pump tube  307 . Around each piston  309 , as illustrated in  FIG. 13 , an outlet valve  213  is slidably received for opening and closing one or more outlet openings  211  in the piston  309 . In the illustrated embodiment, the piston  309  generally includes two main components, a piston arm  310  and a piston head  312  that is connected to the piston arm  310 . As shown, the outlet openings  211  are defined in the piston head  312 . Together, the piston arm  310  and the piston head  312  form a slide notch  314  in which the outlet valve  213  is slidably received. Referring to  FIG. 13 , the pump tubes  307  are integrally formed with the body  50   c . The ends of the pump tubes  307  are closed with a retainer  316  that defines a spring cavity  317  in which the spring  88  is positioned. The pistons  309  each define a piston cavity  318  through which liquid from the outlet openings  211  flow. The pistons  309  for the first  305  and second  306  pump assemblies are joined together at a mixer insert portion  319 . In order to promote mixing of the liquids, the mixer insert portion  319  in one form includes mixer channels  233  and connector channels  234  of the type illustrated for the mixer insert  227  in  FIG. 7 . A piston insert  322  encloses the ends of the piston cavities  318 , and the piston insert  322  has an inner diverter flange  323  that, along with the pistons  309  define flow passages  224  as well as mixed liquid discharge passages  326 .  
      Referring to  FIGS. 11 and 12 , the plunger  123   c  has one or more air holes  328  through which air is supplied to the foamer pump  302 . A valve plate  330  is coupled to the plunger to control the air flow into and out of the pumping chamber  143   c . The valve plate  330 , as shown in  FIG. 13 , includes at least one air inlet valve  331  that allows the inflow of air through one or more air inlet openings  333  in the valve plate  330 , and prevents air back flow. Further, the valve plate  330  includes at least one outlet valve  335 , which permits the outflow of air from one or more air outlet openings  336  in the valve plate  330 .  
      In the illustrated embodiment, the plunger  123   c  has an outer diverter flange  338  that, along with the inner diverter flange  323  of the piston insert  322 , defines a convoluted air passage  176   c . As depicted, the convoluted passage  176   c  is arranged to blow the air traverse to the direction of the mixed liquid from the mixed liquid passage  326  so that foam is created. The newly formed foam is discharged out the spout  116  via the foam aperture  293  in the plunger  123   c . To prime the foamer pump  302 , the spout  116  is pressed and released such that the first and second liquids are drawn into the first  305  and second  306  pump assemblies, respectively. Upon pressing the spout  116  again, the outlet valves  213  open, thereby allowing the liquids flow through the piston cavities  318  and be mixed with the mixer insert portion  319 . At the same time, during the compression stroke, the air from the pumping chamber  143   c  blows through the air outlet valve  335  and the convoluted passage  176   c  to create the foam. Upon releasing the spout  116 , the spring  88  returns the spout  116  to its original position, which in turn draws the liquids into the pump assemblies  305 ,  306 .  
      A multiple liquid inverted foamer  340 , according to still yet another embodiment, will now be described with reference to  FIGS. 14, 15  and  16 . The inverted foamer  340  can be used to dispense many types of liquids, including liquid hand soap. As should be appreciated, many of the features of the inverted foamer  340  can be incorporated into non-inverted type foamers that are oriented differently than the one illustrated. The inverted foamer  340  includes a foamer pump  342  that is threadedly secured to a container  248 . Inside, the container  248  includes a bladder  250  with a connector  198  that is coupled to the foamer pump  342 . Air vent seal  303  is positioned between the container  248  and the foamer pump  342  so as to allow air to vent into the container  348 , while minimizing liquid leakage from the container  248 . As shown, the foamer pump  342  has a spout  344  with a spout opening  345  from which foam is dispensed. The spout  344  is coupled to a plunger  123   d  that is slidably received within cover  268 . One or more air inlet notches  346  are formed at the interface between the spout  344  and the plunger  123   d . The cover  268  is secured to pump body  50   c  with engagement member  269 . Seal member  144  of the plunger  123   d  slidingly seals against the body  50   c  to form air pumping cavity  143   d.    
      As illustrated in  FIG. 14 , first  349  and second  350  pump assemblies extend within the container  248 . The first pump assembly  349  receives the first liquid from the bladder  250 , and the second pump assembly  350  receives the second liquid from the container  248 . As shown, a shroud  352  covers the second pump assembly  350 , and the shroud  352  acts as a straw to draw fluid into the second pump assembly  350 . Each pump assembly  349 ,  350  includes a pump tube  307 , a piston  309  slidably received in the pump tube  307  and a liquid inlet valve  354 . In the illustrated embodiment, the liquid inlet valve  354  includes an umbrella type valve. Around each piston  309 , as illustrated in  FIGS. 15 and 16 , an outlet valve  213 , which is in the form of a sliding seal  214 , is slidably received for opening and closing one or more outlet openings  211  in the piston  309 . According to the illustrated embodiment, the piston  309  generally includes two main components, a piston arm  310  and a piston head  312  connected to the piston arm  310 . As shown, the outlet opening  211  is defined in the piston head  312 . Together, the piston arm  310  and the piston head  312  form a slide notch  314  in which the outlet valve  213  is slidably received. Referring to  FIG. 15 , the pump tubes  307  are integrally formed with the body  50   c . The ends of the pump tubes  307  are closed with a retainer  316  that defines a spring cavity  317  against which the spring  88  presses. The pistons  309  each define a piston cavity  318  through which liquid from the outlet openings  211  flow. The pistons  309  for the first  349  and second  350  pump assemblies are joined together at a mixer insert portion  319 . In order to promote mixing of the liquids, the mixer insert portion  319  in one form includes mixer channels  233  and connector channels  234  of the type illustrated for the mixer insert  227  in  FIG. 7 . A piston insert  322  encloses the ends of the piston cavities  318 , and the piston insert  322  has an inner diverter flange  323  that, along with the pistons  309  define flow passages  224  as well as mixed liquid discharge passages  326 .  
      The plunger  123   d  has one or more air holes  328  through which air is supplied to the foamer pump  342 . Valve plate  330  is coupled to the plunger  123   d  to control the air flow into and out of the pumping chamber  143   d . The valve plate  330  includes at least one air inlet valve  331  that allows the inflow of air through one or more air inlet openings  333  in the valve plate  330 , and prevents air back flow. Further, the valve plate  330  includes at least one outlet valve  335 , which permits the outflow of air from one or more air outlet openings  336  in the valve plate  330 . In the illustrated embodiment, the plunger  123   d  has an outer diverter flange  338  that, along with the inner diverter flange  323  of the piston insert  322 , defines a convoluted air passage  176   c . As depicted, the convoluted passage  176   c  is arranged to blow the air traverse to the direction of the mixed liquid from the mixed liquid passage  326  so that foam is created. The newly formed foam is discharged out the spout opening  345  via the foam aperture  293  in the plunger  123   c . To prime the foamer pump  302 , the spout  344  is pressed and released such that the first and second liquids are drawn into the first  349  and second  350  pump assemblies, respectively. Upon pressing the spout  345  again, the outlet valves  213  open, thereby allowing the liquids flow through the piston cavities  318  and be mixed with the mixer insert portion  319 . At the same time, during the compression stroke, the air from the pumping chamber  143   d  blows through the air outlet valve  335  and the convoluted passage  176   c  to create the foam. Upon releasing the spout  344 , the spring  88  returns the spout  344  to its original position, which in turn draws the liquids into the pump assemblies  349 ,  350 .  
      While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes, equivalents, and modifications that come within the spirit of the inventions defined by following claims are desired to be protected. All publications, patents, and patent applications cited in this specification are herein incorporated by reference as if each individual publication, patent, or patent application were specifically and individually indicated to be incorporated by reference and set forth in its entirety herein.