Abstract:
An inverted refill unit for a dispenser is provided. The refill unit includes a liquid outlet valve in the form of an elastomeric member including a cylindrical side wall, an upper wall having an opening therein, and a valve member extending upwardly from the upper wall to selectively engage a valve seat.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates generally to liquid outlet valves, pumps and refill units for dispensers. 
       BACKGROUND OF THE INVENTION 
       [0002]    Dispensers having inverted refill units, i.e. refill units that have a container full of liquid and a pump located below the container, are generally configured to provide a user with an amount of soap or sanitizer upon actuation of the dispenser. The inverted dispensers may be liquid dispensers or foam dispensers. Inverted foam dispensers generally convert liquid material, such as liquid soap or sanitizer, into foam by aerating the liquid material as it is dispensed. Air is generally injected into the liquid material to form air bubbles in the liquid, causing the formation of foam. Inverted foam dispensers may include a replaceable refill container that is replaced after the liquid material therein is consumed by the user. Liquid outlet valves for inverted dispensers are known. Many prior art liquid outlet valves include springs. 
       SUMMARY 
       [0003]    An inverted refill unit for a dispenser is provided comprising a liquid container and a pump housing secured to the bottom of the container. The pump housing forms a liquid pump chamber, with a liquid inlet valve disposed in a liquid path between the liquid container and the liquid pump chamber. The pump housing further comprises a liquid outlet passage extending from the liquid pump chamber to an annular projection extending away from the liquid pump chamber. A liquid outlet valve includes an elastomeric member including a cylindrical side wall, an upper wall having an opening therein, and a valve member extending upwardly from the upper wall to engage the annular projection in a closed position and disengage the annular projection in an open position. 
         [0004]    In another embodiment, a refill unit for a liquid foam dispenser is provided comprising a housing which includes a mixing chamber, a liquid channel for supplying a liquid to the mixing chamber from an annular projection into the mixing chamber, and an air channel for supplying a pressurized air to the mixing chamber. A liquid outlet valve is located in the mixing chamber, and comprises an elastomeric member including a cylindrical side wall, an upper wall having an opening therein, and a valve member extending upwardly from the upper wall to engage the annular projection in a closed position and disengage the annular projection in an open position. A liquid outlet disposed downstream of the mixing chamber. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]    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: 
           [0006]      FIG. 1  is a cross-section of an exemplary refill unit for a foam pump having a simplified outlet valve; 
           [0007]      FIG. 2  is a perspective view of a simplified one-way liquid outlet valve; 
           [0008]      FIG. 3  is a cross-section view of the simplified one-way liquid outlet valve of  FIG. 2 ; 
           [0009]      FIG. 4  is an enlarged cross-section of a portion of the refill unit and the simplified liquid outlet valve of  FIG. 1  with the simplified liquid outlet valve in a closed position; 
           [0010]      FIG. 5  is an enlarged cross-section of a portion of the refill unit and the simplified liquid outlet valve of  FIG. 1  with the simplified liquid outlet valve in a open position; and 
           [0011]      FIG. 6  is an enlarged cross-section of a portion of a liquid pump and the simplified liquid outlet valve of  FIGS. 2 and 3  with the simplified liquid outlet valve in a closed position. 
       
    
    
     DETAILED DESCRIPTION 
       [0012]      FIG. 1  illustrates an exemplary refill unit  110 . Refill unit  110  includes a container  112  and a foam pump  130 . Foam pump  130  includes a pump housing  102  secured to a neck  101  of container  112  by collar  104 . Collar  104  is secured to container  112  by a snap-fit connection; however, it could be connected by any means, such as, for example a threaded connection, a welded connection, an adhesive connection or the like. 
         [0013]    Located between pump housing  102  and container neck  101  is plate  106 . Plate  106  includes an aperture  107  surrounded above by valve seat  108  which provides a seat for inlet ball valve  111 . Inlet ball valve  111  is retained from below by anchors  109  which are secured to plate  106 . Inlet ball valve  111  is a normally open valve. Accordingly, liquid may flow past the inlet ball valve  111  into liquid inlet channel  115 , past sleeve  114  and into liquid pump chamber  116 . 
         [0014]    When liquid pump chamber  116  is pressurized, as discussed in detail below, inlet ball valve  111  seals against seat  108  to prevent liquid from flowing from pump chamber  116  back into container  112 . In some embodiments, ball valve  111  may be a normally closed valve and in that case may include a biasing member (not shown) to bias the ball valve  111  closed. In addition, although the one-way liquid inlet valve  111  is a ball valve, other types of one-way inlet valves may be used, such as, for example, a mushroom valve, an umbrella valve, a poppet valve, a flapper valve, or the like. 
         [0015]    Pump housing  102  includes a cavity  113 . Located within cavity  113  is a sleeve  114 . A liquid piston  118  moves in a back and forth reciprocating motion within sleeve  114  to increase and decrease the volume of pump chamber  116 . Similarly, located within cavity  113  is an air piston sleeve  153 . Air piston  152  moves in a back and forth reciprocating motion within air piston sleeve  153  to increase and decrease the volume of air chamber  150 . Sleeves  114  and  153  are manufactured with tight tolerances and allow pump housing  102  to be manufactured inexpensively without tight tolerances. 
         [0016]    The liquid piston  118  is connected to liquid piston stem  119 . Liquid piston stem  119  is connected to air piston  152 . Accordingly, movement of air piston  152  also moves liquid piston  118 . Air piston  152  also includes connector  154 . Connector  154  mates with a connector (not shown) on a dispenser (not shown). 
         [0017]    Pump housing  102  also includes one or more liquid outlet passages  127 . Liquid outlet passages  127  are formed in pump housing  102  and extend from cavity  113  to the bottom of pump housing  102 . Pump housing  102  includes annular projection  128  for connecting to lower pump housing  105 . In addition, pump housing  102  includes an annular projection  410  ( FIG. 4 ) which provides a valve seat for one-way liquid outlet valve  190 . 
         [0018]    The lower pump housing  105  of the foam pump  130  has an annular projection  107  for connecting to an annular outlet  157  of air chamber  150 . In addition, lower pump housing  105  includes an outlet  130  and a seat  109 . Lower pump housing  105  retains foaming cartridge  109  and valve  190 . Seat  109  provides support for foaming cartridge  123  which contains one or more foaming screens  124 , and for the one-way liquid outlet valve  190 . 
         [0019]      FIGS. 2-3  provide a detailed view of the one-way liquid outlet valve  190 . One-way liquid outlet valve  190  is an elastomeric member that includes cylindrical side wall  202 , an upper wall  204 , one or more openings  206  in the upper wall  204 , and a valve member  203 . Cylindrical side wall  202  fits within the seat  109  of the lower pump housing  105  to secure one-way outlet valve  190  in place. 
         [0020]    Because one-way liquid outlet valve  190  is used in an inverted refill unit  110 , an important design consideration is that one-way liquid outlet valve  190  needs to prevent static drip. Typically, elastomeric valves that deflect are only used for air and do not need to overcome static drip issues. Static drip occurs when the weight of the fluid in the container either opens the outlet valve  190  or prevents the outlet valve  190  from closing properly. Another design consideration for a liquid outlet valve  190  is the cracking pressure. If the cracking pressure is too high, the pump requires too much force to operate and would not be suitable for use in dispensers, particularly touch-free dispensers where the pump actuator is operated by battery power. These two designs considerations are in opposition to one another. To address these considerations, the one-way liquid outlet valve  190  opens at a pressure that is lower than 3 psi (pounds per square inch), which is a standard dispenser pump operating pressure. 
         [0021]    In some embodiments, outlet nozzle  130  is funnel shaped and, as foam flows through outlet nozzle  130  the velocity of the foam is increased helping to enrich the foam. 
         [0022]    Located between air compressor chamber  150  and mixing chamber  404  is an air outlet passage  158 . Air outlet passage  158  is elongated and located at the bottom of air chamber  150 . In some embodiments, air outlet passage  158  includes a stepped portion  159  where the air outlet passage  158  connects to lower pump housing  105 . This stepped portion may trap and retain residual foam and liquid that is sucked back into air chamber  150  as air piston  152  is moved back to its charged position. 
         [0023]    In some embodiments, a one-way air inlet valve  156  is located in the body of air piston  152 . In some embodiments, a one-way air inlet valve (not shown) is located in a wall of air piston sleeve  153 . One-way air inlet valve  156  has a cracking pressure that is selected so that when air piston  152  is moved from a fully discharged position toward the fully primed or charged position of  FIG. 1 , air is drawn in through though the outlet nozzle  130  and sucks back residual foam and liquid up through air passages  158 . As the air piston  152  moves toward its fully charged position, the vacuum pressure in air chamber  150  increases because of the resistance caused by the foaming screens and air passage  124 . Once the vacuum pressure increases to a set point, the one-way air inlet valve  156  opens and allows air to flow into air chamber  150 . In some embodiments, a cracking pressure of about 3 psi is selected. Thus, foam pump  130  provides for a limited suck back of foam and extends battery life because the one-way air inlet valve  156  allows air piston  152  to move back without the increased resistance of the screen(s)  124 . 
         [0024]    During operation, one-way liquid outlet valve  190  is normally closed as shown in  FIG. 4 . Valve member  203  seals against annular projection  410  of pump housing  102 . To prime or charge foam pump  130 , the liquid piston  118  and air piston  152  are moved outward (to the left in  FIG. 1 ), and liquid flows from container  112  past one-way inlet ball valve  111  through passage  115  into the area defined by cavity  113  and sleeve  114  and into liquid pump chamber  116 . The elastomeric resiliency of the liquid outlet valve  190 , in addition to the suction pressure caused by the outward movement of the liquid piston  118 , hold the valve member  103  in the closed position. Air is initially drawn in through outlet  130  and screens  124 , which sucks back fluid and foam left in the foaming cartridge  123  and outlet  130 . Then, air inlet valve  156  opens and allows air to freely flow into air chamber  150 . 
         [0025]    To discharge foam from pump  130 , the liquid piston  118  and air piston  152  are moved inward (to the right in  FIG. 1 ). Liquid is forced out of liquid pump chamber  116  through liquid outlet passages  127  and the pressure forces the valve member  203  and the upper wall  204  to deflect downward as illustrated in  FIG. 5 . Liquid flows past the valve member  203  and through openings  206  in the upper wall  204  into mixing chamber  404 . Air from air chamber  150  travels through air outlet  158  (picking up residual fluid sucked into the air chamber during priming) into mixing chamber  404  where the air and liquid mix together. The air/liquid mixture is forced through mixing cartridge  123  and dispensed as a foam. When the inward movement of the two pistons  118  and  152  stops, the elastomeric resiliency of the liquid outlet valve  190  urges the valve member  203  and the upper wall  204  to return to the closed position of  FIG. 4 . 
         [0026]      FIG. 6  illustrates another exemplary refill unit  610 . Refill unit  610  includes a container  612  and a liquid pump  630 . Liquid pump  630  includes a pump housing  602  secured to a neck  601  of container  612  by collar  604 . Collar  604  is secured to container  612  by a snap-fit connection; however, it could be connected by any means, such as, for example a threaded connection, a welded connection, an adhesive connection or the like. 
         [0027]    Located between pump housing  602  and container neck  601  is plate  606 . Plate  606  includes an aperture  607  surrounded above by valve seat  608  which provides a seat for inlet ball valve  611 . Inlet ball valve  611  is retained from below by anchors  609  which are secured to plate  606 . Inlet ball valve  611  is a normally open valve. Accordingly, liquid may flow past the inlet ball valve  610  into liquid inlet channel  615 , past sleeve  614  and into liquid pump chamber  616 . 
         [0028]    When liquid pump chamber  616  is pressurized, as discussed in detail below, inlet ball valve  611  seals against seat  608  to prevent liquid from flowing from pump chamber  616  back into container  612 . In some embodiments, ball valve  611  may be a normally closed valve and in that case may include a biasing member (not shown) to bias the ball valve  611  closed. In addition, although the one-way liquid inlet valve  611  is a ball valve, other types of one-way inlet valves may be used, such as, for example, a mushroom valve, an umbrella valve, a poppet valve, a flapper valve, or the like. 
         [0029]    Pump housing  602  includes a cavity  613 . Located within cavity  613  is a sleeve  614 . A liquid piston  618  moves in a back and forth reciprocating motion within sleeve  614  to increase and decrease the volume of pump chamber  616 . Sleeve  614  is manufactured with tight tolerances and allows pump housing  602  to be manufactured inexpensively without tight tolerances. 
         [0030]    The liquid piston  618  is connected to liquid piston stem  619  and includes a connector  654  that mates with a connector (not shown) on a dispenser (not shown). Pump housing  602  also includes one or more liquid outlet passages  627 . Liquid outlet passages  627  are formed in pump housing  602  and extend from cavity  613  to the bottom of pump housing  602 . Pump housing  602  includes annular projection  628  for connecting to lower pump housing  605 . In addition, pump housing  602  includes an annular projection  610  which provides a valve seat for one-way liquid outlet valve  190 , which is the same liquid outlet valve described above with respect to foam pump  130 . Liquid outlet valve  190  operates in the same manner described above and is not re-described with respect to liquid pump  630 . 
         [0031]    Liquid pump  630  includes a lower pump housing  605  that has a seat  609 . Lower pump housing  105  and seat  109  provide support for one-way liquid outlet valve  190 . 
         [0032]    As described above, during operation, one-way liquid outlet valve  190  is normally closed as shown in  FIG. 4 . Valve member  203  seals against annular projection  610  of pump housing  602 . To prime or charge liquid pump  630 , the liquid piston  618  is moved outward (to the left in  FIG. 6 ), and liquid flows from container  612  past one-way inlet ball valve  611  through passage  615  into the area defined by cavity  613  and sleeve  614  and into liquid pump chamber  616 . 
         [0033]    To discharge liquid from pump  630 , the liquid piston  618  is moved inward (to the right in  FIG. 6 ). Liquid is forced out of liquid pump chamber  616  through liquid outlet passages  627  and the pressure forces the valve member  203  and the upper wall  204  to deflect downward as illustrated in  FIG. 5 . Liquid flows past the valve member  203  and through openings  206  in the upper wall  204  and out of outlet  630 . When the inward movement of the two pistons  118  and  152  stops, the elastomeric resiliency of the liquid outlet valve  190  urges the valve member  203  and the upper wall  204  to return to the closed position of  FIG. 4 . 
         [0034]    While various inventive aspects, concepts and features of the inventions may be described and illustrated herein as embodied in combination in the exemplary embodiments, these various aspects, concepts and features may be used in many alternative embodiments, either individually or in various combinations and sub-combinations thereof. It is not the intention of the applicant to restrict or in any way limit the scope of the appended claims to such detail. Unless expressly excluded herein, all such combinations and sub-combinations are intended to be within the scope of the present inventions. Still further, while various alternative embodiments as to the various aspects, concepts and features of the inventions—such as alternative materials, structures, configurations, methods, circuits, devices and components, software, hardware, control logic, alternatives as to form, fit and function, and so on—may be described herein, such descriptions are not intended to be a complete or exhaustive list of available alternative embodiments, whether presently known or later developed. Those skilled in the art may readily adopt one or more of the inventive aspects, concepts or features into additional embodiments and uses within the scope of the present inventions even if such embodiments are not expressly disclosed herein. Additionally, even though some features, concepts or aspects of the inventions may be described herein as being a preferred arrangement or method, such description is not intended to suggest that such feature is required or necessary unless expressly so stated. Still further, exemplary or representative values and ranges may be included to assist in understanding the present disclosure; however, such values and ranges are not to be construed in a limiting sense and are intended to be critical values or ranges only if so expressly stated. Moreover, while various aspects, features and concepts may be expressly identified herein as being inventive or forming part of an invention, such identification is not intended to be exclusive, but rather there may be inventive aspects, concepts and features that are fully described herein without being expressly identified as such or as part of a specific invention. Descriptions of exemplary methods or processes are not limited to inclusion of all steps as being required in all cases, nor is the order in which the steps are presented to be construed as required or necessary unless expressly so stated.