Abstract:
Current designs of dispensers often do not allow for proper ventilation. Additionally, current designs often do not permit proper liquid sealing during shipment. The disclosed apparatus can overcome these shortcomings. This foam dispenser comprises a container, a cylinder device, a collar connected to the cylinder device, the collar operably connecting the container with the cylinder device, and a seal located on the collar, wherein the seal expands under compression to a locked position to create an airtight and liquid tight seal substantially preventing air and liquid from entering or exiting the cylinder device.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims priority from U.S. Provisional Patent Application No. 60/644,387 filed on Jan. 14, 2005, which is hereby incorporated by reference. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention relates generally to hand-operated dispensers, and, more particularly, to foamer dispensers having a seal to create an airtight and liquid tight seal substantially preventing air and liquid from entering or exiting the dispenser.  
       BACKGROUND  
       [0003]     Over the last 15 years or so the use of foam dispensers based on aerosols using pressurized gas has declined steeply for environmental reasons. This has lead to the development of foaming dispensers that exploit a manual pumping action to blend air and liquid to create foam.  
         [0004]     A particular category of such known dispensers, also known as foaming dispensers or foamers, provides both a liquid pump and an air pump mounted at the top of a container. The liquid pump has a liquid pump chamber defined between a liquid cylinder and a liquid piston, and the air pump has an air pump chamber defined between an air cylinder and an air piston. These components are typically arranged concentrically around a plunger axis of the pump. The liquid piston and air piston are reciprocal in their respective cylinders by the action of a pump plunger. Typically the two pistons are integrated with the plunger. An air inlet valve and a liquid inlet valve are provided for the air chamber and liquid chamber. An air discharge passage and a liquid discharge passage lead from the respective chambers to an outlet passage by way of a permeable foam-generating element, normally one or more mesh layers, through which the air and liquid pass as a mixture. Preferably the air discharge passage and liquid discharge passage meet in a mixing chamber or mixing region immediately upstream of the permeable foam-generating element.  
         [0005]     Current designs of dispenser pumps do not allow for proper ventilation to the mating bottle in a pump and bottle system. The failure to achieve proper ventilation prevents vacuum build-up inside the mating liquid bottle as liquid is pumped out of the liquid bottle. In addition, current designs do not permit proper liquid sealing during shipment. Often, the liquid in the liquid bottles will leak out during transportation wasting the liquid and creating an undesirable mess.  
       SUMMARY OF THE INVENTION  
       [0006]     Accordingly, a foam dispenser is disclosed herein. This foam dispenser comprises a container, a cylinder device, a collar connected to the cylinder device, the collar operably connecting the container with the cylinder device, and a seal located on the collar, wherein the seal expands under compression to a locked position to create an airtight and liquid tight seal substantially preventing air and liquid from entering or exiting the cylinder device.  
         [0007]     Another embodiment discloses a foam dispenser that comprises a container, a cylinder device, a collar connected to the cylinder device to operably connect the container with the cylinder device, a plunger, at least a portion of which is mounted within the cylinder device, and a seal located within the collar and engageable with the plunger, wherein the seal is capable of being opened to vent the cylinder device and the container and is capable of being closed to substantially prevent air or liquid from entering or exiting the cylinder component.  
         [0008]     In yet another embodiment, a foam dispenser comprises a container, a cylinder device, a collar connected to the cylinder device, the collar operably connecting the container with the cylinder device, a plunger, wherein at least a portion of the plunger is mounted within the cylinder device, and a seal located on the collar, the seal comprising, an inclined wall, and a cam capable of engaging the plunger with the inclined wall to substantially prevent air or liquid from entering or exiting the cylinder device and the container.  
     
    
     DESCRIPTION OF THE DRAWINGS  
       [0009]     The operation of the foam dispenser disclosed herein may be better understood by reference to the following detailed description taken in connection with the following illustrations, wherein:  
         [0010]      FIG. 1  is a diagrammatical view of an embodiment of a foam dispenser;  
         [0011]      FIG. 2  is a diagrammatical view of the dispenser of the present embodiment without the bottle portion;  
         [0012]      FIG. 3  is a more detailed diagrammatical view of the dispenser of  FIG. 2 ;  
         [0013]      FIG. 4  is a first perspective view of the spout and collar of the dispenser; and  
         [0014]      FIG. 5  is a second perspective view of the spout and collar of the dispenser. 
     
    
     DETAILED DESCRIPTION  
       [0015]     As shown in the accompanying drawings, a hand-operated foam dispenser  1  is shown. The dispenser  1  is mounted on the threaded neck  15  of a conventional blow-molded cylindrical container or bottle  10 . The container or bottle  10 , however, need not be cylindrical. It can take any sort of shape. The dispenser  1  further includes a cylinder device  20  made of material such as polypropylene, and may be of a one-piece construction or multiple-piece construction. The cylinder device  20  includes a lower, smaller-diameter liquid cylinder  25  and an upper larger-diameter air cylinder  30 . The cylinder device  20  is recessed down into the neck  15  of the container  10  and held in place by a threaded retaining collar  35 . In particular, the collar  35  connects to the cylinder device  20  to operably connect the container  10  with the cylinder device  20 . Finally, the dispenser  1  may include an overcap  36 . The overcap  36  engages the collar  35  so as to retain the overcap  36  in place and prevent it from falling off.  
         [0016]     The liquid cylinder  25  further includes a liquid chamber  26 . At the bottom end of the liquid cylinder  25  a valve seat  38  is integrally formed, although it may also be non-integrally connected therewith. A valve ball  39  is seated with in the valve seat  38 . In the current embodiment, the valve ball  39  is a 4 mm ball, but could be of different sizes depending upon the size of the valve seat  38 . Finally, a dip tube or suction pipe  37  is connected to the liquid cylinder  25 , or may be integrally formed therewith. The suction pipe  37  draws the liquid from the bottle  10  into the liquid chamber  26 .  
         [0017]     The cylinder device  20  includes a plunger  42  that is mounted to act reciprocally in the air and liquid cylinders  30 ,  25 . As can be seen in  FIG. 1 , at least a portion of the plunger  42  is mounted within the cylinder device  20 . The plunger  42  includes an integrated cap shroud  45 , a projecting central stem, or more specifically, a piston  47 , carrying a piston seal  50  that works in the liquid cylinder  25 . A tubular piston-retaining insert  51  is snapped into the base of the air cylinder  30  and the liquid piston seal  50  is trapped beneath it. This keeps the plunger  42  in the assembly. A return spring  55  is fitted around the plunger stem  47 , and acts to urge the plunger  42  to its uppermost position. Finally, the plunger  42  includes a spout  57  through which the foamed liquid is dispensed to the operator when such operator uses the foaming dispenser  1  as more specifically described below.  
         [0018]     The air cylinder  30  includes an air chamber  59  and an air piston  61  that surrounds the upper part of the plunger stem  47 . It is retained by a snap fit engagement into the lower end of the cap shroud  45  of the plunger  42 . This cap shroud  45  is of substantially the same diameter as the air cylinder  30 . Pressing down the plunger  42  directly (without play or lost motion) operates the air piston  61  in its cylinder  30 .  
         [0019]     Considering now the central parts of the plunger  42 , the spout  57  communicates with an inner axial downwardly-open tube  63  that forms a top foamer unit housing. This tube  63  snap fits into an upwardly-open cylindrical tube  64  of a core insert component  65 , trapping in the space between them a foam-generation element  67  in the passage leading to the spout  57 . This foam-generating element  67  has a cylindrical plastic tube  68  fitting closely in the housing tube  63  and having ultrasonically welded across its open ends a disk of coarse nylon mesh  70  (bottom end) and fine nylon mesh  71  (top end).  
         [0020]     It will be noted that in the current embodiment the piston seal  50  of the liquid piston is of the “sliding seal” type that acts as a discharge valve at the entrance to the liquid discharge passage  74 . That is to say, on the downstroke of the plunger  42  the sliding seal  50  is displaced upwardly relative to the plunger stem  47  and uncovers the plunger stem windows  75 . This allows liquid to flow under pressure from the liquid pump chamber  26  into the liquid discharge passage  74  and through the foam-generating element  67  to create the foamed liquid.  
         [0021]     The action of the pump on pressing down the plunger is as follows. At the same time as liquid is driven up passage  74  as mentioned, air in the air chamber  61  is forced—by the decrease in volume of that chamber—through an air outlet valve  77  into the air discharge chamber and radially in from all directions to mix vigorously with the rapid and distributed upflow of liquid. The liquid and air flows mix as they enter the foam generating element  67  when they pass through the progressively decreasing meshes  70 ,  71  and merge as foam from the spout  57 . The one-way action of the air inlet valve flap  80  prevents escape of air from the chamber  61  by that route, as the plunger  42  is depressed.  
         [0022]     Conversely, as the plunger  42  rises again under the force of the spring  55 , the liquid chamber  26  is primed in the conventional way via the inlet valve  35 . Air flows in to occupy the air chamber  61  by downward displacement of the air inlet valve  80  relative to its valve seat under the prevailing pressure difference. Air flows into the air chamber  61  from cap air apace inside the cap shroud  45  that encloses the inlet valve  80 . In turn, air may enter the cap air space via channel clearances between channels of the air piston insert sleeve  90  and the bottom rim of the cap shroud  45 . Alternatively, air may enter the cap shroud  45  via an upper opening in the shroud itself, the air piston sleeve  90  being connected air tightly.  
         [0023]     The dispenser  1  further includes a seal  100 , also referred to as an up-lock seal. The seal  100  is located on the collar  35 . The seal  100  may comprise a sealing ring as shown in the drawings. Alternatively the seal  100  can be any sort of seal. The seal  100  can be integrally formed with the collar  35  or can be connected therewith through a subsequent procedure. The seal  100  is airtight and liquid tight, substantially preventing air or liquid from entering or exiting the dispenser  1 . The geometry of the seal  100  is such that it along with the surface finish and the material properties of such cause expansion under compression. More specifically, the seal  100  has an inclined plane shaped wall  105  (as shown in  FIGS. 2 and 3 ) that contributes to expansion under compression. Further, the collar  35  and the bottle  10  and all components thereof are made of polypropylene co-polymer. The polypropylene co-polymer expands and shrinks in a reasonably consistent and predictable manner that accurately seals itself. This further contributes to the accurate expansion under compression.  
         [0024]     The required compression is provided by the action a cam  107  pulling the plunger  42  into the seal  100 . During operation, the seal  100  acts as a valve  108  that opens and closes by actuating (or more specifically, rotating) the spout  57 /plunger  42  assembly. When the plunger  42  is rotated, it creates an interference fit that causes the valve  108  to close. Alternatively, the plunger  42  could be lifted to create an interference fits that causes the valve  108  to close. In particular, this interference condition results from expanding the seal  100  outward as the cam pulls the plunger  42  into the seal  100 . The expansion of the seal  100  increases its diameter to create a solid interference fit between the body of the container  10 , the collar  35 , and the plunger  42 . At its maximum expansion, a high stress condition is created and acts positively to close off the air passage and seal the liquid inside the container  10 . Conversely, once the spout  57 /plunger  42  assembly is actuated to the operational state, the interference is removed, and the seal  100  collapses in size sufficiently to positively open the valve  108  sufficiently to allow air to vent into the container  10 .  
         [0025]     The seal  100  further includes a chamfer or a radius. The chamfer/radius assists in guiding and forcing the plunger  42  to slide into the seal  100 . On the other hand, a squared-off surface on the seal  100  will act as a catch. This will place a significant load on the plunger that can cause the plunger  42  to become out of square. If this condition occurs, the plunger air seal gets damaged and the entire foaming dispenser will be rendered useless and inoperable.  
         [0026]     The operation of the seal  100  may be assisted by the use of two semi-circular segments  117  on the collar  35 . These semi-circular segments  117  act as a squaring standoff. This holds the plunger  42  tight and square in the uplock state as well as acting as a bearing surface for the plunger  42  as it is activated. Further, the collar  35  includes two protrusions  104 ,  107 . The two protrusions  104 ,  107  engage two cam keys  115  that are located within the plunger  42 . Alternatively, any number of protrusions and cam keys can be used herewith, e.g., one, three, etc. Additionally, the number of protrusions need not necessarily match the number of cam keys. In the current embodiment one cam key is bigger than the other, although they could also be of the same size. This assists functions to align the plunger  42  and dispenser head properly, especially during operation of the dispenser  1 . The two cam keys  115  engage the protrusions  104  and  107  to set the dispenser  1  in a locked position or an operational position. Further, the cam keys  115  of different sizes prevent the dispenser  1  from being assembled backward. Alternatively, two keys of equal size can be used if the application does not require key alignment. One of the keys can be a partial length of the other provided they both pull evenly in the locked position.  
         [0027]     The dispenser  1  of the present invention seals both liquid and air then converts to open a vent using an air lock that opens and can be re-sealed by twisting the top of the plunger shaft to the locked position. Further, the dispenser  1  provides a foaming dispenser or foamer with a valve that can be opened and closed by the position of the seal. The valve prevents vacuum build-up inside a mating liquid bottle as liquid is pumped out. Finally, the dispenser can be placed in a locked position so that the plunger cannot be accidentally depressed. This is especially useful when the dispenser is transported to prevent accidental release of the liquid contained therein.  
         [0028]     The invention has been described above and, obviously, modifications and alternations will occur to others upon a reading and understanding of this specification. The claims as follows are intended to include all modifications and alterations insofar as they come within the scope of the claims or the equivalent thereof.