Abstract:
Dispensers are provided including pumps for dispensing a foamed product out of an outlet provided in a dispensing tube. The foam is created from the mixing of a foamable liquid and air, with separate pumps being provided for each component. The dispensing tube is stationary, although the pumps themselves have parts that must move to dispense the foamed product. A single actuator operates both the liquid and air pumps. Additionally, in some embodiments, the air pump advances air before the liquid pump advances liquid. These pumps are particularly suited to the dispensing of a foamed skin care or skin sanitizing product.

Description:
RELATED APPLICATIONS 
     This application claims priority to and the benefits of U.S. Non-Provisional patent application Ser. No. 11/728,557 filed on Mar. 26, 2007 and entitled FOAM SOAP DISPENSER WITH STATIONARY DISPENSING TUBE, which incorporated herein by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     The invention herein resides in the art of soap dispensers. In particular embodiments, the invention relates to a foam soap dispensing system mounted to a counter, wherein a foam soap pump is mounted under a counter and receives a liquid soap container. 
     BACKGROUND OF THE INVENTION 
     The use of soap dispensers continues to grow as the awareness for the need for good hand hygiene practices grows. Numerous types of dispensing systems are known, including portable, hand held dispensers, wall mounted dispensers, and counter mounted dispensers. Typically, these soap dispensers dispense a predetermined amount of liquid soap upon actuation. Over the past decade or so, interest has grown in foam soap  15  dispensers, wherein air and liquid soap are mixed to form and dispense substantially homogenous foam. 
     Inline actuated foam soap dispensers are of particular interest because they have a number of drawbacks that can be improved upon. These dispensers include an actuator that is pressed to compress air and soap chambers to force air and soap through a mixing chamber to create foam. The foam is then forced through a dispensing spout. The dispensing tube is coupled to the actuator that is reciprocated to dispense the foam, and thus the dispensing tube moves as the actuator is pressed to dispense product and as it returns to its rest position. These dispensers work satisfactorily in the hand held dispenser embodiments, because the dispensing tube and the spout through which the foam is dispensed are formed in the actuator, and the user can simply place a hand under the spout to catch the foam dispensed therethrough even though the dispensing tube and spout move during dispensing. However these dispensers present problems in a counter mounted environment in which the dispensing tube and spout are decoupled from the actuator. 
     In the counter mounted dispenser, a liquid soap source is mounted under a counter top and coupled to pumping mechanisms to deliver soap or foam at an outlet of a dispensing tube that extends through a rigid, stationary spout provided above the counter, preferably at a sink basin. The actuator for the dispenser is located proximate the spout and is pressed to dispense foam through the outlet of the dispensing tube. Pressing on the actuator causes air and liquid soap pumps to advance air and soap to be mixed and forced through the dispensing tube. The dispensing tube is coupled to the pump mechanisms such that, as the actuator is reciprocated to cause the pump mechanisms to compress and expand, the dispensing tube reciprocates within the spout. The reciprocation of the dispensing tube within the spout uses up energy in a dispenser that reciprocates the pumps electronically, and requires a larger amount of force to actuate by hand in a manually actuated dispenser. 
     Most counter mounted soap dispensers also create foam below the counter, proximate the soap and air pump mechanisms, and then force the foam up through a significant length of dispensing tube. This creates a few problems. First, the foam can degrade as it travels through the dispensing tube, yielding a poorer foam product. Second, pushing foam through a length of dispensing tube requires more force than pushing separate air and liquid soap sources, and this makes the actuator for the soap dispenser more difficult to push and, in the case of an electronically activated automatic soap dispenser, requires additional electric power. Published patent application 2006/0011655 shows a counter mounted soap dispenser that creates foam at the spout rather than proximate the pumping mechanisms under the counter, but it is focused solely on a system with separate electronic soap and air pumps and is not structurally similar to inline actuated soap dispensers. 
     Thus, there exists a need in the art for a foam pump wherein the dispensing tube is stationary during the dispensing of foam and during the refill of the pump with air and liquid. The pumps and dispensers herein will be found suitable for the dispensing of a variety of single or multi-component products. This need is particularly strong in the counter mount environment. This need exists specifically in the dispensing arts for skin care and skin sanitizing products, and, more specifically, the dispensing of foamed soaps and foamed sanitizing products. 
     SUMMARY OF THE INVENTION 
     In one embodiment, this invention provides a dispenser having a stationary dispensing tube, i.e., the dispensing tube does not move upon actuation of the dispenser to dispense product. The dispenser includes a liquid container holding a liquid, a compressible liquid chamber compressible to a compressed volume and biased to expand to an expanded volume, and a dip tube extending from the compressible liquid chamber into the liquid in the liquid container, wherein compression of the compressible liquid chamber forces liquid within the compressible liquid chamber into the stationary dispensing tube, and expansion of the compressible liquid chamber draws the liquid up through the dip tube and into the compressible liquid chamber. The dispenser further includes a compressible air chamber compressible to a compressed volume and biased to expand to an expanded volume, and an air passage communicating between the compressible air chamber and the stationary dispensing tube, wherein compression of the compressible air chamber forces air within the compressible air chamber into the stationary dispensing tube, and expansion of the compressible air chamber draws air into the compressible air chamber. 
     In accordance with another embodiment, this invention provides a dispenser that includes a mixing chamber, a compressible liquid chamber, a compressible air chamber, and a dual actuator. The compressible liquid chamber contains a liquid and is adapted to selectively reciprocate between an expanded volume and a compressed volume. The compressible liquid chamber advances the liquid to the mixing chamber when selectively moved to the compressed volume. The compressible air chamber contains air and is adapted to selectively reciprocate between an expanded volume and a compressed volume. The compressible air chamber advances air to the mixing chamber when selectively moved to the compressed volume. The dual actuator is selectively moved to compress both the compressible liquid chamber and the compressible air chamber to their compressed volumes, wherein upon such movement of the dual actuator, the air chamber begins to be compressed prior to the beginning of the compression of the liquid chamber. 
    
    
     
       DESCRIPTION OF DRAWINGS 
       For a complete understanding of the structure and techniques of the invention, reference should be made to the following detailed description and accompanying drawings wherein: 
         FIG. 1  is a general perspective view of a dispenser in accordance with this invention; 
         FIG. 2  is a cross section representation of the components of the dispenser taken along a line through the dip tube  76  and dispensing tube  46 ; 
         FIG. 3  is an assembly diagram of the dispenser; 
         FIG. 4  is a cross section along the line  4 - 4  of  FIG. 2 , showing the axial support  40  and its air channel  44 ; 
         FIG. 5  is a cross section along the line  5 - 5  of  FIG. 2 , showing the valve plate  62  associated with the compressible liquid chamber  52 ; 
         FIG. 6  is a cross section along the line  6 - 6  of  FIG. 2 , showing the liquid pump  15  support  30  and its liquid channel  68  and air channel  88 ; 
         FIG. 7  is a cross section along the line  7 - 7  of  FIG. 2 , showing the communication of elbow  86  and its communication between liquid pump support  30  and dispensing tube  46 , and also showing the coaxial tube construction of dispensing tube  46 ; and 
         FIG. 8  is a general representation of the dispenser shown in a counter mount environment. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to  FIGS. 1-3 , an embodiment of a dispenser in accordance with this invention is shown and designated by the numeral  10 . Dispenser  10  includes product container  12 , which holds product P to be dispensed through actuation of a foam pump mechanism  14 . Generally, the product P held within container  12  will be a liquid or other substance that can be pumped against gravity to be dispensed. 
     Foam pump mechanism  14  fits into container  12  at open end  16 . Referring to  FIGS. 2 and 3 , foam pump mechanism  14  includes compressible air chamber  18 , which is received in threaded neck  20  of container  12 , resting on upper radial flange  22 , preferably with a container gasket  24  between flange  22  and the open end  16  of threaded neck  20 . Container gasket  24  serves to prevent liquid from leaking out during shipping and handling of the container  12 . An axial support  26  extends upwardly from bottom wall  28  of air chamber  18 . Axial support  26  receives liquid pump support  30  fitting axially thereover with sidewall  32  of liquid pump support  30  extending down the sides of axial support  26  and snapping into place on axial support  26  as at annular rib  34  and annular detent  36 . Thus an annular volume for air chamber  18  is defined between sidewall  38  of air chamber  18  and sidewall  32  of liquid pump support  30 . The annular volume is further defined by air piston  40 , which includes an aperture  42  for fitting over axial support  26 . Air piston  40  intimately contacts sidewall  32  and sidewall  38  such that the contact is substantially air tight. However, as best seen in  FIG. 4 , axial support  26  includes an axial trough defining air channel  44  between the outer surface of axial support  26  and the inner surface of sidewall  32  of liquid pump support  30 . Air channel  44  communicates with the volume of air in air chamber  18  and ultimately fluidly communicates with dispensing tube  46  through a path in liquid pump support  30 . 
     Compressible air chamber  18  contains air and is adapted to selectively reciprocate between an expanded volume and a compressed volume. A biasing member  48  forces air piston  40  to a rest position defining an expanded volume for air chamber  18 . Compressible air chamber  18  is compressed by forcing air piston  40  against biasing member  48 , and a compressed volume is reached. This causes air to be forced through air channel  44  and ultimately into dispensing tube  46 . By relaxing the force against biasing member  48 , air piston  40  returns to its rest position, reestablishing the expanded volume. As air piston  40  returns to its rest position, air is pulled in back through dispensing tube  46  to fill the expanding volume of air chamber  18 , i.e., air is pulled into air chamber  18  through a path opposite to the path the air takes when forced out of air chamber  18 . This can help prevent dripping at the spout outlet, as will be described more fully herein below. Optionally, a one-way air valve such as that represented at the numeral  50  can be placed on air piston  40  or elsewhere communicating with air chamber  18 . 
     Compressible liquid chamber  52  is sealed to liquid pump support  30  through retaining ring  54 . Dip tube  76  extends through dip tube channel  56  in liquid pump support  30  and through axial channel  57  in axial support  26  to communicate between the volume of container  12  and that of compressible liquid chamber  52  through ball valve  58 . More particularly, compressible liquid chamber  52  is formed of a flexible diaphragm  60 , which is secured to axial support  26  over valve plate  62  and valve film  64 . The volume of compressible liquid chamber  52  may be filled with a sponge material, if desired, to take of some of the volume and help the chamber recover from compression. Valve plate  62  includes inlet aperture  65  and outlet aperture  66  ( FIG. 5 ), with inlet aperture  65  being aligned with dip tube channel  56  and outlet aperture  66  being aligned with liquid channel  68  ( FIG. 6 ) in liquid pump support  30 . Valve film  64  includes has an opening  63  ( FIG. 3 ) aligned with inlet aperture  65 , and these perforations  70  serve to allow liquid to pass into compressible liquid chamber  52 , past the ball  72  of ball valve  58 . Valve film  64  also includes a flap valve  74  ( FIG. 3 ) aligned with outlet aperture  66 , and flap valve  74  serves to allow liquid to pass into liquid channel  68  in liquid pump support  30 . The actual movement of the liquid, into compressible liquid chamber  52  through dip tube  76  and dip tube channel  54 , and out of compressible liquid chamber  52   15  through outlet aperture  66 , is based upon the compression and expansion of the volume of compressible liquid chamber  52 . 
     Flexible diaphragm  60  is made from a resilient material that naturally rests in the position shown in  FIG. 2 , having an expanded volume. Thus, as is generally known, compressible liquid chamber  52  can selectively reciprocate between an expanded volume and a compressed volume. Compressible liquid chamber  52  is compressed by pressing on flexible diaphragm  60 , and a compressed volume is reached. This compression of compressible liquid chamber  52  causes liquid held therein to be forced through outlet aperture  66  and ultimately into and through dispensing tube  46 . Flap valve  74  is a cut out portion of valve film  64  positioned below outlet aperture  66 , as seen in  FIG. 3 , and it bends to allow liquid to pass therethrough. During compression, liquid is prevented from moving into dip tube  76  because ball  72  contacts and seals off dip tube channel  56  where it narrows at sloped walls  78 . Thus a dose of liquid is forced through outlet aperture  66  and flap valve  74  and toward dispensing tube  46  during compression of compressible liquid chamber  52 . By relaxing the pressure on flexible diaphragm  60 , it returns to its natural, expanded volume rest position and, while doing so, draws liquid up through dip tube  76 , past ball  72  and into compressible liquid chamber  52 . More particularly, as seen in  FIG. 5 , inlet aperture  65  has notches  67  that permit the passage of liquid past ball  72  even though it contacts inlet aperture  65  as it is drawn upward by the suction created at liquid chamber  52 , i.e. the notches stick out beyond the ball  72  and the remainder of the inlet aperture  65  holds the ball  72 . During expansion, liquid is prevented from being drawn back in at outlet aperture  66  because outlet aperture  66  is smaller than flap valve  74  and thus prevents flap valve  74  from flipping upward to permit liquid to pass therethrough. 
     As an alternative, the function of ball valve  58  could be replaced with an inlet flap valve in valve film  64  overlying an inlet aperture in valve plate  62 . This would provide flow control into and out of compressible liquid chamber  52 . Also, flexible diaphragm  60  could be a more rigid chamber and piston design, such as that shown for the compressible air chamber herein. 
     Thus far, liquid and air have been described to advance from their respective sources, i.e., compressible air chamber  18  and compressible liquid chamber  52 , and ultimately into dispensing tube  46 . The paths taken by the liquid and air are now more particularly disclosed. First, it should be appreciated that dispenser  10 , upon first being constructed, will have liquid product P in container  12 , and compressible liquid chamber  52  will be empty. With repeated compression and expansion of compressible liquid chamber  52 , liquid product will be incrementally advanced up through dip tube  76  and into compressible liquid chamber  52 , with an incremental advancement being dependent upon the difference in volume of compressible liquid chamber  52  between its compressed and expanded state. Once compressible liquid chamber  52  is filled, compression thereof will begin to advance liquid toward dispensing tube  46  and ultimately the outlet  80  at the tip of spout  82 . The advancement toward outlet  80  will also be incremental. After a number of repetitive compressions and expansions, the entire liquid path through dip tube  76  to outlet  80  will be filled with liquid product P, and each compression of compressible liquid chamber  52  will expel a dose of liquid product at outlet  80 . Although dispenser  10  will have an air path completely filled with air upon construction, is should still be appreciated that the air, like liquid product P, will be advanced incrementally through dispenser  10  along its path under the compression of compressible air chamber  18 . As already disclosed, as compressible air chamber expands, air will incrementally suck back through outlet  80  and reverse along is path toward the expanding volume of compressible air chamber  18 . With this understanding, the paths for air and liquid toward outlet  80  are next disclosed. 
     Referring to  FIGS. 5-7 , liquid exits compressible liquid chamber  52  through outlet aperture  66  and flap valve  74  and enters radial liquid channel  68  in liquid pump support  30 . Liquid channel  68  extends radially to communicate with liquid path  84  in elbow  86 . Axial air channel  44  communicates with radial air channel  88 , through aperture  90  in liquid pump support  30 , and parallels liquid channel  68  to communicate with air path  92  in elbow  86 . Air and liquid are thus still separate in dispenser  10 . Through their respective paths  84 ,  92 , in elbow  86 , liquid and air next communicate with dispensing tube  46 , which is preferably constructed to keep the air and liquid separate until just proximate outlet  80 . 
     With reference to  FIG. 7 , it can be seen that dispensing tube  46  is defined by coaxial tubes, a central liquid dispensing tube  94  and an outer annular air dispensing tube  96 . Liquid dispensing tube  94  communicates with liquid path  84 , and air dispensing tube  96  communicates with air path  92 . Both tubes  94  and  96  terminate at mixing chamber  98 , which is bounded by inlet mesh  100  and outlet mesh  102 . Outlet mesh  102  preferably defines outlet  80  or is located very close to outlet  80 . In this way, the air and liquid are kept separate as they are advanced to the outlet  80 . This makes dispenser  10  easier to operate, because less force is needed to advance the separate air and liquid streams than would be required to advance foam through dispenser  10 , were it created directly proximate outlets of the compressible air chamber and compressible liquid chamber, as is generally practiced in the prior art. 
     Referring back to  FIGS. 2 and 3 , dispenser  10  is operated through either manual or electronic movement of dual actuator  104 . Dual actuator  104  is shown as a cylindrical piston member sized to have a diameter that permits its movement within the radial confines of compressible air chamber  18 . Its bottom edge  106  contacts piston  40  of compressible air chamber  18 , and its top wall  108  overlies compressible liquid chamber  52 , preferably with a compression delay element  110  therebetween, as shown. Dual actuator  104  includes a cut-out portion  111  in its sidewall  114  for permitting the extension of elbow  86  radially outwardly of dual actuator  104 . A stop rib  112  extending from sidewall  114  engages lip  116  of cap  118  to retain dual actuator  104  in a rest position against the force of biasing member  48 . 
     Dual actuator  104  is moved against the bias force of biasing member  48  (and also compression delay element  110 ) to compress both compressible air chamber  18  and compressible liquid chamber  52 . This advances doses of air and liquid through the dispenser  10  as already described, thus making foam at mixing chamber  98 , exiting at outlet  80 , through a stationary dispensing tube  46 . Pressing down on dual actuator  104  presses down on flexible diaphragm  60 , through compression delay element  110 , thus compressing it and advancing liquid through dispenser  10 , as described. Compression delay element  110  gives under the initial pressure and thus serves to delay the collapsing of flexible diaphragm  60  relative to the movement of piston  40 . This causes a small amount of air to be moved before any liquid is advanced, and the air so moved will build up pressure due to the resistances to its movement through the small clearances throughout the air path and the resistance to movement of the air through inlet mesh  100 . Thus, when liquid is moved upon adequate displacement of dual actuator  104  both the liquid and air enter mixing chamber  98  under pressure to create a high quality foam product. If the air path was not pre-pressurized prior to the liquid advancing then the foam product would be very wet at the beginning of dispense. 
     Upon the release of pressure pushing down on dual actuator  104 , biasing member  48 , flexible diaphragm  60 , and compression delay element  110  all serve to aid the system in reverting back to its normal rest position. Compressible air chamber  18  and compressible liquid chamber  52  expand, with liquid being drawn up dip tube  76  into compressible liquid chamber  52 , and air being drawn down from the outlet through mixing chamber  98  and annular air dispensing tube  96 , ultimately back into compressible air chamber  18 . This movement of air through the outlet back into the system can help prevent dripping at outlet  80 . 
     It should be appreciated that the dispenser  10  shown in the drawings is particularly useful in a counter mounted environment, but the general structures and concepts disclosed herein could be applied to hand held dispensers and wall mounted dispensers. In a hand held embodiment, the dispenser  10  would simply be constructed with the structural elements disclosed for dispenser  10 , with those elements constructed so as to produce a sleek external appearance and facilitate plunger actuation. In a wall mounted environment, the structural elements could again be readily adapted to fit within common wall mounted housings. 
     In a counter mount embodiment, cap  118  threads onto threaded neck  20  to press upper radial flange  22  against gasket  24 , and thus helps to secure the mechanics of dispenser  10 . A keyed overcap  130 , also with a cut-out portion for elbow  86 , fits over cap  118  and serves as a means for securing the combination container  12 , associated compressible liquid and air chambers  52 ,  18 , elbow  86  and dispensing tube  46  to bottle support  14 , as described in copending US Published Patent Application No. 2007/0017932. 
     The counter mounted dispenser  10  is shown in  FIG. 8 . Container  12  is preferably received in bottle support  140 , and dispensing head  160  is secured to bottle support  140  at connector  150 , preferably without the need for rotating bottle support  140  relative to head  160 . An extension  170  of head  160  telescopes into connector  150  until apertures (not shown) in extension  170  align with apertures in connector  150  to permit a lock pin to be inserted therethrough to hold bottle support  140  and associated container  12  to extension  170  and dispensing head  160 . Foam pump mechanism  14  is secured to container  12  and actuated by the depression of plunger  200  to dispense product P at the outlet  80  of spout  280 . Extension  170  and bottle support  140  permit the passage of shaft  132  (see  FIG. 2 , where shaft  132  is shown in ghost to reflect that it is only particularly applicable in a non hand held environment), which extends from association with plunger  200  to engage top wall  108  of dual actuator  104 , and the passage of the dispensing tube  46  for carrying product from container  12  to the outlet  80  of spout  280 . 
     In an electronically activated system, plunger  200  would be replaced with a hands-free activation means, such as a sensor that, when tripped, activates electronic means to move gearing mechanisms to advance shaft  132  to compress the compressible air and liquid chambers  18 ,  52 . The electronic means would also permit the shaft to cycle back to its rest position, thus putting the system in a state ready for a subsequent actuation. 
     In accordance with the foregoing, in particular embodiments of this invention, the product P is a liquid that is capable of foaming when mixed with air, and the product P is particularly chosen from a foamable skin care or skin sanitizing product. However, this invention is not limited to the dispensing of such products, particularly because it will be readily appreciated that the proposed dispensers herein could be employed for other products. 
     In light of the foregoing, it should thus be evident that the present invention provides a dispensing system that substantially improves the art. In accordance with the patent statutes, only the preferred embodiments of the present invention have been described in detail hereinabove, but this invention is not to be limited thereto or thereby. Rather, the scope of the invention shall include all modifications and variations that fall within the scope of the attached claims.