RELATED APPLICATIONS 
       [0001]    This application claims priority to and the benefits of U.S. Provisional Patent Application Ser. No. 61/918,504 filed on Dec. 19, 2013 and entitled “PUMPS WITH VENTS TO VENT INVERTED CONTAINERS AND REFILL UNITS HAVING NON-COLLAPSING CONTAINERS,” which is incorporated herein by reference in its entirety. 
     
    
     TECHNICAL FIELD 
       [0002]    The present invention relates generally to liquid dispenser systems and more particularly to air-vented liquid dispensers, as well as refill units for use with such dispensers. 
       BACKGROUND OF THE INVENTION 
       [0003]    Liquid dispenser systems, such as liquid soap and sanitizer dispensers, provide a user with an amount of liquid upon actuation of the dispenser. It is desirable to provide such a dispenser having a rigid container that is vented with air so that the pump may re-prime itself after a dispensing action. It is also desirable to provide such a dispenser that is easily recharged once the container runs out of liquid to dispense, and that is inexpensive to produce. 
       SUMMARY 
       [0004]    Exemplary embodiments of refill units having foam pumps and non-collapsing containers are disclosed herein. In some exemplary embodiments, the refill unit includes a non-collapsing container and a foam pump. The foam pump includes a compressible air chamber. The foam pump includes a passage between the interior of the compressible air chamber and the interior of the container. A regulating valve regulates flow of air from the interior of the compressible air chamber to the interior of the container. 
         [0005]    Another exemplary embodiment of a refill unit includes a non-collapsing container and a foam pump. The foam pump includes a compressible air chamber and an air passage between the interior of the compressible air chamber and an interior of the container. A moveable valve secured to the passage. The movable valve has a first position that prevents pressurized air from flowing from the air chamber into the interior of the container and a second position that allows vacuum pressure in the interior of the container to draw air from the interior of the compressible air chamber to the interior of the container. 
         [0006]    Another exemplary refill unit includes a non-collapsing container and a foam pump. The foam pump has a compressible air chamber and a passage between the interior of the compressible air chamber and an interior of the container. The foam pump includes a valve secured to the passage. The valve has a wiper seal located within the interior of the container and a second seal located at least partially within the compressible air chamber. 
         [0007]    In this way, a simple and economical refill unit with a container vent located between the air pump chamber and the container are provided. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    These and other features and advantages of the present invention will become better understood with regard to the following description and accompanying drawings in which: 
           [0009]      FIG. 1  is a cross-section of an exemplary liquid dispenser having a refill unit with a pull pump; 
           [0010]      FIGS. 2 and 3  are partial cross-sections of the exemplary refill unit. 
           [0011]      FIGS. 2A and 3A  are enlarged cross sections of an exemplary venting valve of the exemplary embodiment of the refill unit. 
       
    
    
     DETAILED DESCRIPTION 
       [0012]      FIG. 1  illustrates an exemplary embodiment of a dispenser  100 . The cross-section of  FIG. 1  is taken through the housing  102  to show the pump  120  and container  116 . Dispenser  100  includes a disposable refill unit  110 . The disposable refill unit  110  includes a container  116  connected to pump  120 . The dispenser  100  may be a wall-mounted system, a counter-mounted system, an un-mounted portable system movable from place to place or any other kind of liquid dispenser system. Dispenser  100  is a foam dispenser. 
         [0013]    The container  116  forms a liquid reservoir that contains a supply of foamable liquid within the disposable refill unit  110 . In various embodiments, the contained liquid could be, for example, a soap, a sanitizer, a cleanser, a disinfectant. In the exemplary disposable refill unit  110 , the container  116  is a non-collapsible container and can be made of thin plastic or like material. The container  116  may advantageously be refillable, replaceable or both refillable and replaceable. 
         [0014]    In the event the liquid stored in the container  116  of the installed disposable refill unit  110  runs out, or the installed refill unit  110  otherwise has a failure, the installed refill unit  110  may be removed from the foam dispenser  100 . The empty or failed disposable refill unit  110  may then be replaced with a new disposable refill unit  110 . 
         [0015]    The housing  102  of the dispenser  100  contains one or more actuating members  104  to activate the pump  120 . As used herein, actuator or actuating members or mechanisms include one or more parts that cause the dispenser  100  to move liquid, air or foam. Actuator  104  is generically illustrated because there are many different kinds of pump actuators which may be employed in the foam dispenser  100 . The actuator  104  of the foam dispenser  100  may be any type of actuator such as, for example, a manual lever, a manual pull bar, a manual push bar, a manual rotatable crank, an electrically activated actuator or other means for actuating the pump  120 . Electronic actuators may additionally include a sensor  132  for detecting the presence of an object and to provide for a hands-free dispenser system with touchless operation. Various intermediate linkages, such as for example linkage  105 , connect the actuator member  104  to the pump  120  within the system housing  102 . An aperture  115  is located in bottom plate  103  of housing  102  and allows liquid dispensed from the nozzle  125  of pump  120  to be dispensed to a user. 
         [0016]      FIGS. 2 and 3  are partial cross-sections of an exemplary embodiment of refill unit  110 . Foam pump  120  includes a collar  201  that connects to the neck  117  of container  116 . Collar  201  may connect to neck  117  of container  116  in any manner such as for example a threaded connection. 
         [0017]    Foam pump  120  includes a housing  202  that fits at least partially within neck  117 . Foam pump  120  includes an inner cylindrical housing  204 . In addition, housing  202  includes an first annular projection  208  and an aperture  209 . Aperture  209  extends from inside the container  116  into liquid pump chamber  306 . A liquid inlet valve  208  is located within aperture  209 . Liquid inlet valve  208  is a one-way valve that allows liquid to flow from the container  116  into liquid pump chamber  306 . Liquid inlet valve  208  may be any type of one-way valve, such as for example, a wiper valve, ball and spring valve, an umbrella valve, a flapper valve or the like. 
         [0018]    Cylindrical pump housing  202  includes a second annular projection  210 . Located within annular projection  210  is an aperture  211 . Aperture  211  extends between the inside of the container  116  and air pump chamber  320  of foam pump  120 . A venting valve  240  or regulating valve is located at least partially within aperture  211 . As can be more clearly seen in  FIG. 2A  and  FIG. 3A , venting valve  240  includes an elongated body  241  with a head  242  on a first side. Head  242  includes a sealing surface  244 . On the second side of elongated body  211  is a wiper seal  246 . Wiper seal  246  engages the inner wall of annular projection  210 . Venting valve  240  moves freely up and down in aperture  241  and there is a gap between elongated member  241  and the walls of aperture  211  to allow air to flow past elongated body  211 . 
         [0019]    Foam pump  120  includes a piston  212 . Piston  212  has a first engagement member  213  and a second engagement member  214 . First engagement member  213  and second engagement member  214  engages an actuator  105  ( FIG. 1 ) to move piston  212  upward and downward. Piston  212  includes an air piston seal  220  and a liquid piston seal  310 . Piston  212  also includes a sealing member  312 . In addition, piston  212  includes an aperture that is located between liquid piston seal  310  in seal  312  and extends to the interior of piston  212 . Piston  212  has a hollow interior  316  from aperture  314  to outlet to  216 . In addition foam pump  120  includes a biasing member  327  to bias piston  212  in the downward direction. 
         [0020]    During operation, as piston  212  moves downward from the position shown in  FIG. 2  to the position shown in  FIG. 3 , liquid flows from the container  116  past one-way liquid inlet valve  208  into liquid pump chamber  306 . As air pump chamber  320  expands, air is drawn in through outlet  216  into air pump chamber  320 . In addition, venting valve  240  moves from the position shown in  FIG. 2A  to the position shown in  FIG. 3A . When venting valve  240  moves downward, sealing surface  244  moves away from housing  245  and opens a path from air pump chamber  322  to area  250  located below wiper seal  246 . As liquid is pumped out of container  116  a vacuum pressure is created in container  116 . Once the vacuum pressure in container  116  rises above the cracking pressure of venting valve  240 , air from area  250  flows into container  116  to vent the container. 
         [0021]    When foam pump  120  moves from the position shown in  FIG. 3  upward to the position shown in  FIG. 2 , liquid in pump chamber  306  flows past liquid outlet seal  310  through aperture  314  and down outlet passage  316 . Simultaneously, air flows from air pump chamber  320  through passage  321  and into passage  316  where it mixes with the liquid. The liquid and air mixture in passage  316  is forced through screens  317 . The turbulence caused by the screens creates a rich foam that is forced out of outlet  216 . The pressure in air pump chamber  320  pushes venting valve  240  upward causing sealing surface  244  to engage housing portion  245  and seals the air pump chamber  320  from the interior of container  116  to prevent air from flowing from the air pump chamber  320  into container  316 . 
         [0022]    While the present invention has been illustrated by the description of embodiments thereof and while the embodiments have been described in considerable detail, it is not the intention of the applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. Therefore, the invention, in its broader aspects, is not limited to the specific details, the representative apparatus and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of the applicant&#39;s general inventive concept.
Exemplary embodiments of refill units having foam pumps and non-collapsing containers are disclosed herein. In some exemplary embodiments, the refill unit includes a non-collapsing container and a foam pump. The foam pump includes a compressible air chamber. The foam pump includes a passage between the interior of the compressible air chamber and the interior of the container. A regulating valve regulates flow of air from the interior of the compressible air chamber to the interior of the container.