Abstract:
The present invention relates to a conduit for conducting gasified liquid, which has a flow restrictor arranged in in-line relation therewith. The restrictor itself comprises an at least one aperture (although two or more can be used in series), with each such being adapted to pass the gasified liquid flowing through the conduit and across a pressure drop from a higher-pressure upstream side of the aperture to a lower-pressure downstream side of the aperture. The aperture is operable to moderate the rate of change in pressure over a transitional pressure drop to mitigate the formation of localized pressures below a critical pressure at which off-gassing from the carbonated liquid results in substantial foam formation. The conduit may take the form of a dispensing tube for use in dispensing an alcoholic beverage from a keg, the tube having a flexible wall deformable under the influence of a restricting actuator to control the partial collapse of the wall and thereby form the restrictor. The tube or flow diameter downstream of the restrictor only gradually or slowly increases.

Description:
FIELD OF THE INVENTION 
     The present invention relates to an alcohol beverage dispensing apparatus and in particular, relates to a beer line for dispensing beer, usually in association with tap adapter for mounting with a container or keg. 
     BACKGROUND OF THE INVENTION 
     It is known to contain alcohol, such as wine in bags contained in a cardboard type container where the wine feeds by gravity through a shut off tap mounted outside the container. Further, it is known to fill a bag with beer in a keg. In the case of a beer keg, pressure is applied to the bag to dispense the beer from the bag and out of the keg. Further, the bag is inserted into the keg container prior to the beer being filled into the bag through a valve assembly. 
     However, there is a need for the user to be able to control the dispensing of the beer from the keg out through a tap connected to the valve assembly particularly in special circumstances where the beer is to be dispensed directly from the keg. These special circumstances occur when the keg is utilized at an outdoor activity or where a consumer does not desire to purchase a home beer dispensing system and still desires to make use of beer stored in a keg. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a conduit for fluidized liquids that helps to reduce foam generation during flow through the conduit. The present invention finds application in relation to conduits for conducting carbonated liquids; or, a nitrogenated liquids; or a combination carbonated and nitrogenated liquids. Although a variety of uses for such conduit can be envisaged, the application as a liquid dispense conduit is particularly relevant with regard to avoiding excessive foam formation—and examples of this arise in beverage dispensing, especially in the case of beer. 
     In another embodiment, the invention provides a tap adapter for dispensing a beverage from a container whilst controlling the generation of excessive foaming. 
     Generally speaking, the present invention relates to a conduit for conducting gasified liquid, which conduit has a flow restrictor arranged in in-line relation therewith. Moreover, it is important, that the flow diameter must be only gradually increased downstream of the restrictor. 
     The restrictor itself comprises an at least one aperture (although two or more can be used in series), each such being adapted to pass the gasified liquid flowing through the conduit and across a pressure drop from a higher-pressure upstream side of the aperture to a lower-pressure downstream side of the aperture. 
     The aperture is operable to moderate the rate of change in pressure over a transitional pressure drop to mitigate the formation of localized pressures below a critical pressure at which off-gassing from the carbonated liquid results in substantial foam formation. 
     In some applications it is actually preferable to employ a plurality of apertures arranged in series along the path of the gasified liquid flow. In this case, sequential downstream pressure drops are produced between successive pairs of apertures to respective intermediate pressures that are lower than the pressure upstream of the first aperture in the series and higher than the pressure downstream of the last aperture in the series. This arrangement improves the overall effect of mitigating against foam formation. At least two such apertures, and preferably static apertures are preferred. 
     In a particularly preferred embodiment, the conduit contains at least one aperture which is venturi-shaped. It is desirable, particularly in the case of beer dispensing operations, that such a venturi has a back angle of less than 24 degrees, preferably about 20 degrees or less, and even more preferably, about 15 degrees or less. 
     The conduit is preferably formed as a formed tube having an integral stricture arranged along the length thereof, to provide for the requisite aperture and, in preferred embodiments, to form the venturi shaped aperture in particular. Although the tubing can be preformed (cast or extruded for example) to provide for the requisite aperture, it is also possible to form the tube in situ. For example, where the conduit is a pliable tube, which is compressible in situ to form an aperture by the application of external force—the application of external force such as a clamping action along a tube-contacting face of a cam or wedge shaped body, can be used to produce a correspondingly shaped aperture within said tube and hold the tube in position relative the rest of a dispensing apparatus. Again, the internal diameter of the tube post the stricture increases only gradually, for example, resulting in the interior walls of the tube having an effective back angle of less than 24 degrees. 
     Preferably the inlet end and the outlet end of the conduit are substantially the same internal diameter—although variations on this are possible if desired. In any case, in a beer dispense application, it is desirable that the inlet end be adapted to engage a beer keg valve; and, that the outlet end be a nozzle through which the beer is dispensed into a beverage container. Such a conduit—“dispensing tube”—is inexpensive and easily installed. Moreover, it is particularly well suited to use if comprised of a flexible tubing that can be compressed by an external clamping valve to constrict flow between substantially free flowing dispense and shut-off conditions. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a better understanding of the nature and objects of the present invention reference may be had to the accompanying diagrammatic drawings in which: 
         FIG. 1  is a front elevation view of a home beer dispensing apparatus in accordance with the present invention; 
         FIG. 2  is a side elevation view of the home beer dispensing apparatus; 
         FIG. 3  is broken away perspective view of the keg showing the valve and spear assembly mounted within the keg; 
         FIG. 4  is a sectional side view of the valve and spear assembly as shown in  FIG. 3 ; 
         FIG. 5  is a plan view of the valve body of the valve assembly; 
         FIG. 6  is a sectional side view of the tap adapter mounted to the keg; 
         FIG. 7  is a side sectional view of the tap adapter of  FIG. 6  showing the tap pivoted open; 
         FIGS. 8 and 9  are perspective views of the tap adapter respectively showing the hollow arm in closed and open positions; 
         FIG. 10  is a schematic cross-section of a venturi arrangement according to the present invention, and depicting operating conditions and dimensions particularly suited to beer dispensing applications; 
         FIG. 11  is an exploded view of a tap adapter showing the insertable tubular cartridge comprising a venturi equipped conduit of the present invention; 
         FIG. 12  is a side section view of the tap adapter of  FIG. 11 ; 
         FIG. 13  is a perspective view of the tap adapter showing the hollow arm in an open position and the tube ready for insertion into the adapter; 
         FIG. 14  is an elongated side sectional view showing partial collapsing of the dispensing tube; and 
         FIGS. 15 to 17  are further elongated side sectional views showing partial collapsing of the dispensing tube. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In a preferred application of the present invention, a venturi equipped conduit is employed as an insertable cartridge in a beer tap aperture—which is useful in turn, in dispensing beer from a keg in either free-standing applications, or from within a housing as for example in the case of a beer cooling appliance or the like, such as is described in  FIG. 2 . 
     Referring to  FIGS. 1 and 2  there is shown a home beer dispensing apparatus, appliance or unit  10 . The dispensing apparatus  10  is primarily intended for use in domestic kitchens but may also be used in utility rooms, garages, domestic bars, caravans etc. While the preferred embodiment relates to dispensing beer, alternatively carbonated solutions or other alcohol beverages may be dispensed by apparatus  10 . 
     The home beer dispensing apparatus  10  has a front wall  12  and a dispensing tap  14  protruding forward of the front wall  12 . A drip tray  16  also protrudes forward of the front wall  12  and is adapted to support an open glass container  18  below the dispensing tap  14 . The home beer dispensing apparatus  10  further has a base  21  adapted to rest on a counter top. The front wall  12  is an extension of two pivoting side walls  20  which may be moved between closed and open positions to allow the keg  22  (see  FIG. 2  in broken lines) to be inserted into the housing of the home beer dispensing apparatus  10 . 
     The housing  17  of the home beer dispensing apparatus  10  further includes a top wall  24  and a rear wall  26 . The rear wall  26  has a grill  30  that permits for air circulation within the home beer dispensing apparatus  10 . An electrical cord  32  extends through the rear wall  26  of the apparatus  10  to provide a connection into a main electrical supply to supply electrical power to the electrical components housed within the unit  10 . Alternatively, a 12 Volt DC supply input may be used. 
     The dispensing apparatus  10  has a cooling system  34  located behind and below keg  22  that is adapted to cool beer in keg  22  when keg  22  is placed into dispensing apparatus  10 . 
     Referring to  FIGS. 3 through 5 , the preferred valve assembly  40  and spear  102  are shown. The valve assembly  40  is adapted to fit into a raised collar aperture  42  of keg  22 . The valve assembly  40  has an annular shaped body  46  that is secured in the aperture  42 . The valve body  46  has an annular groove  47  and flange  49  that is adapted to extend above the keg  22  for mating with a tap dispensing adapter  38  ( FIG. 4 ) connected to tap  14 . 
     The valve body  46  has a first passageway  48 , a second passageway  50 , and a third passageway  52  spaced apart from each other and extending through the valve body  46 . As best seen in  FIG. 8 , the first passageway  48  is centrally disposed or located within the valve body  46  and the second and third passageways  50 , and  52  are spaced radially of the first central passageway  48 . 
     The valve assembly includes a first valve  54 , a second valve  56  and a third valve  58 . The first valve  54  is seated in the first passageway  48  for controlling the flow of the beverage or beer through the first passageway  48  into and out of the bag  44 . 
     The second valve  56  is seated in the second passageway  50  for controlling the flow of gas such as carbon dioxide through the second passageway  50  into and out of the bag. 
     The third valve  58  is seated in the third passageway  52  and controls the flow of gas through the third passageway  52  into and out of the keg  22  exterior to the bag  44 . 
     Each valve,  54 ,  56 , and  58  has a valve actuator or stem  60  that effectively opens and closes the valve. The valve stem  60  extends away from the valve body  46  by a different predetermined distance for each of valves  54 ,  56  and  58 . Each of the valves  54 ,  56  and  58  further include a valve head  70  connected to the valve stem  68 . The valve head  70  carries an O-ring  72  which is adapted to seal the valve head within the respective passageway. A spring  74  urges the valve head  70  into sealing engagement with its corresponding passageway. The valve stems  68  are accessible from outside the keg  22  for moving each valve head  70  into an open and closed position to respectively enable and inhibit fluid flow through passageways  48 ,  50  and  52 . 
     The valve body  46  has an annular recessed groove  62  recessed in an inner wall  64  of the valve body  46 . The inner wall  64  is positioned within the keg  22 . The recessed groove  62  is adapted for receiving the neck  66  of bag  44  in press fit relation therewith. The annular recessed groove  62  has a diameter that surrounds the first and second passageways  48  and  50 . The third passageway  52  is located outside of the diameter of the recessed groove  62  and as a result, the third passageway  52  is located outside of the bag  44 . 
     The keg  22  has a collar flange  82  which defines the raised collar aperture  42 , the valve body  46  has an outer peripheral wall  63  with a recessed groove  61  extending around the outer wall  63 . An intermediate ring or bung  80  is adapted to seat the valve body  46  within the raised collar aperture  42 . The intermediate ring  80  has inner and outer walls  84 ,  86 . The inner wall  84  has flange  88  extending inwardly thereof that is adapted to fit into the recessed groove  61  of the outer wall  63  of the valve body  46 . The outer wall  86  of the intermediate ring  80  has a resilient barb  90  and a locking flange  92  spaced from the barb  90  so as to define an outer locating groove  94  into which the collar flange  82  of the keg  22  is held. The barb  90  is adapted to pass through the aperture  42  and spring back into locking engagement with the collar flange  82  so as to lock the valve assembly  40  in place. Special tools are required to remove the valve assembly  40  and the intermediate ring  80  from the collar flange  82  of the keg  22  once the keg  22  is returned to the brewery for refilling. 
     In order to ensure that the contents of the keg  22  have not been tampered with, the keg  22  has an anti-tamper ring  96  that overlays the intermediate ring  80 , a portion of the keg  22  and a portion of the valve body  46 . The intermediate ring  80  has an aperture  98  that passes completely through the intermediate ring  80  to provide a vent passageway. The anti-tamper ring  96  has a flange part  100  that is inserted into the vent aperture  98  of the intermediate ring  80 . In the event the anti-tamper ring  96  is removed from the keg  22 , vent aperture  98  is open and the contents or any pressure within the keg  22  is released. Further, as a pressure relief feature, the anti-tamper ring  96  is designed to release from aperture  98  when pressure in keg  22  exceeds a predetermined valve to vent pressurized air through aperture  98 . 
     Referring to  FIGS. 6 to 9 , the tap adapter  38  of the present invention is shown in more detail. The tap adapter  38  is mounted to the valve assembly  40  in fluid flow communication with the first valve  54 . This attachment is a snap action sealed attachment on inner and outer walls of valve flange  49 . 
     The dispenser adapter  38  has a hollow arm  120  that has a first end portion  122  adjacent the valve assembly  40  and a second end portion  124  which is remote therefrom. The first end portion  122  is connected to the first valve  54  so as to open the valve  54 . This connection is made when the adapter is snap fitted downwardly onto the valve neck flange  49 . The hollow arm  120  extends from the valve assembly  40  out through the housing  17  to a position where the remote end portion  124  of the hollow arm  120  is outside of the housing  17 . 
     As better shown in  FIGS. 7 and 9 , the hollow arm  120  is separable by a hinge point  130 . The arm  120  is separable into an upper arm portion  132  and a lower arm portion  134 . As shown in  FIG. 9 , lower arm portion  132  carries the tap  14  integral therewith. The lower arm portion  134  comprises a half hollowed out passageway  137  (see  FIG. 9 ). 
     The immediate following describes in detail a first embodiment wherein the foam controlling element takes the form of a cartridge located in the hollow arm  120  of the adaptor  38 . Inserted into this lower arm portion  134  is a tubular cartridge  126  that has a tube  128  that interconnects the tap  14  with the first valve  54  so that the beverage may flow through the tube  128  and out the tap end  136 . The cartridge  126  is in effect a frame like member which is adapted to be snap fitted into place with the lower arm portion  134 . The cartridge  126  also carries the tube  128  therethrough for connection into the first end portion  122  of the hollow arm  120  so that when the cartridge is inserted into the hollow arm  120 , and the hollow arm is subsequently mounted onto the valve assembly  40 , one end  129  of the tube  128  sealingly engages passageway  48  and opens valve  54  so that beverage may be dispensed through valve  54  and into the tube  128 . The upper arm portion  132  as shown in  FIG. 9  may then be snapped back into place relative to the lower arm portion  132 . 
     The adapter  38  is provided with a base portion  140  for supporting the hollow arm  120 . The base portion  140  has a neck or supporting ring  142  that is adapted to surround and releasably engage the valve neck flange  49 . The base portion  140  further includes an annular flange portion  144  which provides an inverse shape of a saucer that is adapted to abut the top surface of the keg  22  and to be supported thereon. 
     The base portion  140  has locking spring members  146  (see  FIG. 9 ) that engage the valve neck groove  47  and are movable to release the adapter  38  from the valve assembly  40 . 
     Tap  14  is connected to the remote end  124  of the hollow arm  120  and in particular the lower arm portion  134 . The tap is operable between a closed position to shut off the flow of beverage through the hollow arm as shown in  FIG. 6  and an open position permitting beverage to flow through the hollow arm and out the tap  14  as shown in  FIG. 9 . The tap  14  also forms an integral part of the hollow arm  120  and in particular the lower portion  134 . The tap  14  has a handle  140  that is pivotally connected to a cam member  150  so as to rotate cam member  150  into pinching engagement against tube  128  as indicated at pinching point  152 . The handle will be normally biased in this position and may be drawn forward to release cam member  150  from the tube  128  and thereby open the tube at point  152  and permit beverage to be dispensed along the tube  128  contained within the hollow arm  120  from the valve assembly  40 . 
     As shown in  FIGS. 6 to 9 , the dispensing adapter  38  includes an air line passageway  160  adapted to be connected to a second air valve  58  in fluid flow communication. The air line passageway  160  has a first end or cap member  162  that connects to and opens the second valve  58  when the adapter  38  is snap fitted onto the valve system  40 . The air line passageway  160  has a second end portion  164  having a one way air valve  166  that is normally shut and that is opened when connected, for example, to a manually operable bellows air pump  10 . Manual squeezing of pump  10  supplies air under pressure to the inside of keg  22  against bag  44 . The air line passageway  160  is an integral part of the adapter  38 . 
     The adapter  38  of the present invention has many advantages. In particular, the adapter  38  can be sold as a separate part to a consumer and the cartridge  126  may be sold as a replacement cartridge with each keg  22  refill for insertion into adapter  38  so as to provide a sanitary dispensing medium for the beverage. The cartridge  126  is inserted into the adapter  38  and the adapter  38  is moved into its closed position and snapped onto the keg neck  47 . Because the adapter carries the tap  14  which is in a closed position, the snapping of adapter  38  onto the valve assembly  40  of the keg  22  in sealing relation therewith opens valve  54  and provides for a simple and reliable connection that does not result in any loss of beverage. At this time, the air supply line  160  is connected to the air valve  58  of the valve assembly  40 . The keg  22  is ready for use as a portable free standing unit. 
     The adapter  38  is now ready to dispense beverage by drawing handle  148  forward releasing the cam  150  from pinching the tube  128  allowing the beverage to flow therethrough out through valve  54 . It should be understood that pressure is applied against the bag  44   FIGS. 3 and 4 ) in through the air line passageway  160  and through the valve  58  of the valve assembly  40  by manual operation of pump  10 . 
     Referring now to  FIG. 10  of the drawings, there is illustrated a schematic longitudinal cross-section through a section of conduit  200  according to the present invention, in which the venturi  201  structure is illustrated. As dimensioned, and for the operating conditions set out, the arrangement is particularly suited to home beer dispense applications. 
       FIGS. 11 and 12  illustrate the conduit  200  and the venturi  201 , in relation to a beer dispense tap apparatus. Although not shown,  FIG. 12  makes it clear generally how a cam shaped clamp could be employed relative to a flexible conduit when clamped into the tap apparatus, to form the an aperture shape, in situ, this aspect of the invention being described in detail below. 
     Referring to the drawings in general, and referring to an especially preferred embodiment of the present invention, the beer line possesses a venturi or a portion of tube that: tapers down gradually from around 8 mm to 1.5 mm; continues at 1.5 mm diameter for 50 mm or 60 mm; and then expands outwards gradually back (through a back angle) to around 8 mm. The length and diameter of the restricted portion combine to determine both the delivered flow rate of beer and the pressure drop across the restrictor. In the preferred case, this should be around 1 bar—the internal pressure of the keg—to avoid beer foaming. The diameter of the restrictor is also an influential factor—too large a diameter and the dispense flow rate is too high and there is little pressure drop, too narrow a diameter and the dispense flow rate is very slow. In forming the venturi, the tapered convergent and divergent sections are adapted to ensure that vortices are not created in the beer flow, which would lead to out localized low pressure regions and related out-gassing and foaming. 
     In a preferred form of venturi system to reduce pressure and control flow, an 8 mm standard diameter tube is used, having a 1.5 mm diameter through the integrally formed venturi, which extends for a length of over 50 mm, and expands at a 20° inclusive angle (or by 10 degrees on both side) back to a final conduit diameter of 8 mm. This gradual return to the original tubing diameter reduces risk of foaming for the beer transiting this conduit (at about 2 liters/min.). Note that the same angles can be used on the upstream side of the venturi in reducing from the nominal tube diameter to the narrow venturi tube diameter. Under the conditions described herein and in the drawings, all sections of the conduit up stream of venturi including up to the keg valve, are above foaming pressure. Minimising distance after venturi to the dispense spout is also helpful. 
     Beer dispensing in this case involves a continuous dispense rate of between 1.5 liters/minute and 2.0 liters/minute without “excessive” foaming for the conditions described below. Air pressure maintained between 1.2 bar gauge and 1.5 bar gauge; beer temperature (bottom 25%)&lt;9° C. 
     The cartridge is preferably a disposable item, and can be supplied new with each keg that a consumer purchases. Ease of use and sanitation are advantages of this arrangement. 
     Turning now to a second embodiment of the present invention wherein a collapsible dispensing tube is used to provide a flow restriction—refer to  FIGS. 13 and 17 , where inserted into the lower guide channel  137  is an elongated dispensing tube  126 . Referring to  FIG. 13 , the dispensing tube  126  defines a passageway through which beverage flows to be dispensed from the adapter  38 . The dispensing tube  126  has a first end portion  200  comprising a 90 degree elbow connector that passes through aperture  202  in the lower arm portion  134  of the adapter  138 . The connector  200  has a cylindrical port  204  which sealingly engages with valve  54 . The dispensing tube  126  has a second end portion  206  which is passed into and through the tap  14  to communicate beverage out through the tap end or spout  136 . The length of the dispensing tube  126  comprises a flexible walled material and is herein referred to as a flexible wall portion  210 . In particular this flexible wall portion  210  is located between the end portions  200  and  206  of the tube  126 . During assembly of the tube  126 , the adapter connector  200  is inserted through aperture  202  and also the tube  126  is inserted into the lower guide channel  137  with the end  206  passing into the spout  136 . Thereafter the upper arm portion  132  is pivoted about pivot point  130  downwardly into a closed position. Arms  132 ,  134  are locked in place by latches  212  on lower arm portion  134  which lock over fingers  214  found in the upper arm portion  132  of the adapter  38 . The upper arm portion  132  is further provided with an upper elongated guide channel  220  that has side guide walls  222 . As the upper arm portion  132  is closed on the lower arm portion  134  the upper elongated guide channel  220  passes over the tube  126  and locks the tube within the lower guide channel  137 . 
     The upper guide channel  220  is provided with a flow restricting actuator  240 . The actuator  240  comprises a wall protrusion protruding inwardly from the recessed guide channel  220  and positioned between the side walls  222 . This wall protrusion or flow restricting actuator  240  is of fixed size and shape. Alternatively, protrusion  240  could pivot about the fingers  214  and have its movement controlled by adjusting screw (not shown) passing threadingly through the top face  250  of the upper arm portion  132  to push against wall protrusion  240  so as to control the extent that the protrusion  240  protrudes from the upper elongated guide channel  220 . 
       FIG. 14  shows the effect on the tube  126  from closing the upper arm portion  132  on the lower arm portion  134 . In particular,  FIG. 14  shows a cross sectional view through the tube  126  where the protrusion  240  restricts the cross sectional diameter of the passageway in the tube  126 . As shown in  FIG. 14 , the tube  126  rests on the recessed guide channel  137 . The tube  126  is also supported by the upper recessed guide channel  220  and is partially collapsed by the flow restricting actuator  240  engaging the flexible wall portion  210  of the tube  126 . This flow restriction in the tube  126  acts to counter any excessive pressure in the keg dispense apparatus. That is, pressure that is applied within the keg  22  (see  FIG. 3 ) against the bag  44  to collapse the bag  44  and push beverage out through the spear  102 , valve  54  and tube  126  to the spout  136 . In  FIG. 14 , the collapsed portion  260  of the flexible tube  126 , the flow aperture, is clearly reduced but subsequently increases slowly or gradually downstream from the restrictor toward end  206  and acts to counter any excessive pressure and thereby control the flow of beverage out through the spout  136 . As a result, by restricting the flow of beverage, the beverage flows at a predetermined dispense flow rate chosen to reduce excessive or undesirable foaming of the beverage. 
     The adapter  38  is provided with a base portion  140  for supporting the hollow arm  120 . The base portion  140  has a neck or supporting ring  142  that is adapted to surround and releasably engage the valve neck flange  49 . The base portion  140  further includes an annular flange portion  144 —see FIG.  9 —which provides an inverse shape of a saucer that is adapted to abut the top surface of the keg  22  and to be supported thereon. The base portion  140  has locking spring members  146  (see  FIG. 13 ) that engage the valve neck groove  47  and are movable to release the adapter  38  from the valve assembly  40 . Tap  14  is connected to the remote end  124  of the hollow arm  120  and in particular the lower arm portion  134 . The tap is operable between a closed position to shut off the flow of beverage through the hollow arm as shown in  FIG. 6  and an open position permitting beverage to flow through the hollow arm and out the tap  14  as shown in  FIG. 7 . The tap  14  also forms an integral part of the hollow arm  120  and in particular the lower portion  134 . The tap  14  has a handle  140  that is pivotally connected to a cam member  150  so as to rotate cam member  150  into pinching engagement against tube  126  as indicated at pinching point  152 . The handle will be normally biased in this position and may be drawn forward to release cam member  150  from the tube  126  and thereby open the tube at point  152  and permit beverage to be dispensed along the tube  126  contained within the hollow arm  120  from the valve assembly  40 . 
     Referring to  FIGS. 15 to 17  the dispensing tube  126  is shown collapsed in different manners. In  FIG. 15  the protrusion  240  is moved from the solid line portion shown at  240  to the broken line portion at  240   a  to thereby partially collapse the dispensing tube  126 . This partial collapse of the dispensing tube in  FIG. 15  is similar to that shown in  FIG. 14 . 
     In  FIG. 16 , the dispensing tube  126  is shown collapsed from two opposing sides. In this embodiment the protrusion  240  and the lower arm portion  134  of the hollow arm  120  are brought into engagement at the same time with the dispensing tube  126 . This results in the protrusion  240  in the lower arm portion  134  of the hollow arm  120  ending up in position  134   a . It should be understood that the lower arm portion  134  may also be provided with its own protrusion to thereby partially collapse the dispensing tube  126 . Because the upper arm portion  132  moves relative to the lower arm portion  134  in the preferred embodiment, the protrusion in the lower arm portion  134  begins to partially deflect or collapse the tube  126  as the upper arm portion  132  is closed upon the lower arm portion  134  and thereby brings the protrusion  240  into engagement with the dispensing tube  126 . 
     In  FIG. 17 , the upper arm portion is selectively collapsible to bring protrusion  240  either into the position shown at  240   a  or the position shown at  240   b . The first position shown at  240   a  is the partial collapse of the dispensing tube  126 . This provides the requisite flow restriction which is the subject of the present invention. However, the upper arm portion  134  may be closed to bring the protrusion  240   a  into the position shown at  240   b  whereby the tube  126  is completely closed. This acts as a valve a close the tube to allow for the second end portion  124  of the dispensing adapter  38  and other component parts of the dispensing adapter  38  located downstream from the closure to be serviced and cleaned.