Abstract:
There is disclosed a plastics assembly for a viscous liquid dispenser ( 1 ). The plastic assembly includes an outer cover disc ( 41 ) mated with a thin inner nozzle disc ( 42 ) wherein the cover disc ( 41 ) is dimensioned to be retained at a first end of a cylindrical tube of viscous liquid to seal the tube prior to dispensing commencing, cover disc ( 41 ) having a frangible cover ( 42 ) formed thereon. The thin inner nozzle disc ( 42 ) includes an outer rim dimensioned to be received in the interior of the cover disc ( 41 ) and the thin nozzle ( 42 ) disc includes at least one nozzle aperture formed therein wherein the nozzle aperture is covered by the frangible cover ( 46 ).

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to viscous liquid dispensers and, in particular, to a dispenser used to dispense food sauces at fast food restaurants such as McDONALDS or KFC.  
       BACKGROUND OF THE INVENTION  
       [0002]     The prior art food dispenser has found widespread commercial application in such fast food outlets and consists of a spiral wound cardboard tube which has a metal annulus seamed onto the tube at one end (the dispensing end) and a forcing disc or plunger at the second end. The metal annulus has a MYLAR sheet glued to the metal annulus and the sheet is provided with at least one nozzle formed by two intersecting cuts. In order to seal the nozzle, and thereby seal the tube prior to dispensing, a metal foil is releasably glued to the front of the mylar sheet. The plunger is moved towards the nozzle when the tube is located in a dispensing gun so as to extrude the viscous contents of the tube through the nozzle(s).  
         [0003]     The abovementioned arrangement is relatively expensive to fabricate because of the provision of metal parts. In addition, the metal foil has been found to be difficult to remove whilst the operator is wearing plastic gloves which are now a requirement in food serving industries.  
       OBJECT OF THE INVENTION  
       [0004]     The aim of the present invention is to provide a nozzle assembly and/or a forcing disc which are made from plastics material and thus are significantly cheaper than the abovementioned metal parts.  
       SUMMARY OF THE INVENTION  
       [0005]     In accordance with a first aspect of the present invention there is disclosed a plastics assembly for a viscous liquid dispenser, said assembly comprising an outer cover disc mated with a thin inner nozzle disc, said cover disc being dimensioned to be retained at a first end of a cylindrical tube of said viscous liquid to seal said tube prior to dispensing commencing and having a frangible cover formed therein, said nozzle disc having an outer rim dimensioned to be received in the interior of said cover disc, and said thin nozzle disc having at least one nozzle aperture formed therein, said nozzle aperture being covered by said frangible cover.  
         [0006]     In accordance with a second aspect of the present invention there is disclosed a plastics forcing disc for a viscous liquid dispenser, said disc having a substantially cylindrical side wall with an annular end flange thereon to abut against the cylindrical wall of a liquid containing tube having first and second ends, whereby prior to dispensing commencing said disc covers and seals said second tube end, said end flange being provided with a plurality of spaced apart locations of weakness whereby a sufficient axial force applied to said forcing disc distorts said end flange sufficiently for said forcing disc to travel down the interior of said tube towards said first end thereof.  
         [0007]     In accordance with a third aspect of the present invention there is disclosed a viscous liquid dispenser comprising a tube having a first and second ends and having the abovementioned nozzle assembly sealing the first end and the abovementioned forcing disc sealing the second end.  
         [0008]     In accordance with a fourth aspect of the present invention there is disclosed, in combination, the above viscous liquid dispenser when mounted in a dispensing gun having a pushing plate which bears against the forcing disc. 
     
    
     DESCRIPTION OF THE FIGURES  
       [0009]     A preferred embodiment of the present invention will now be described, by way of example only, with reference to the drawings in which:  
         [0010]      FIG. 1  is a schematic perspective view of a dispensing gun of the prior art,  
         [0011]      FIG. 2  is a schematic perspective view of the prior art dispenser,  
         [0012]      FIG. 3  is an interior plan view of the plastics forcing disc of the preferred embodiment,  
         [0013]      FIG. 4  is a transverse cross-sectional view taken along the line IV-IV of  FIG. 3 ,  
         [0014]      FIG. 5  is an enlarged fragmentary view of a portion of  FIG. 4 ,  
         [0015]      FIG. 6  is an interior perspective view of the forcing disc of  FIGS. 3-5 ,  
         [0016]      FIG. 7  is a side elevation of the forcing disc of  FIGS. 3-6 ,  
         [0017]      FIG. 8  is an exterior plan view of the forcing disc of  FIGS. 3-7 ,  
         [0018]      FIG. 9  is a fragmentary enlargement of a portion of the disc illustrated in  FIG. 8 ,  
         [0019]      FIG. 10  is a fragmentary enlargement of a portion of the forcing disc illustrated in  FIG. 7 ,  
         [0020]      FIG. 11  is an exterior perspective view of the forcing disc,  
         [0021]      FIG. 12  is a perspective view of the nozzle cover disc able to be inserted into the first end of the dispensing tube,  
         [0022]      FIG. 13  is a plan view of the cover disc of  FIG. 12 ,  
         [0023]      FIG. 14  is a cross-sectional view taken along the line XIV-XIV of  FIG. 13  of  FIG. 12 ,  
         [0024]      FIG. 15  is a fragmentary enlargement of a portion of  FIG. 14 ,  
         [0025]      FIG. 16  is another fragmentary enlargement of a portion of  FIG. 14 ,  
         [0026]      FIG. 17  is an interior perspective view of the nozzle cover disc,  
         [0027]      FIG. 18  is an interior plan view of the nozzle cover disc,  
         [0028]      FIG. 19  is a side elevation of the cover disc,  
         [0029]      FIG. 20  is a fragmentary enlargement of  FIG. 19 ,  
         [0030]      FIG. 21  is a perspective view of the inner nozzle disc,  
         [0031]      FIG. 22  is a plan view of the nozzle disc of  FIG. 21 ,  
         [0032]      FIG. 23  is a cross-sectional view taken along the line XXIII-XXIII of  FIG. 22 ,  
         [0033]      FIG. 24  is an enlarged fragmentary view of the rim of the nozzle disc of  FIGS. 21-23 , and  
         [0034]      FIG. 25  is an enlarged view of the centre portion of the nozzle disc. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0035]     As seen in  FIG. 1 , a dispensing gun  1  has a tube receiving barrel  2  mounted on a frame  3 . A pistol grip  4  and trigger  5  enable a plunger  6  to be moved by a ratchet mechanism  7  towards the barrel  2 . The plunger  6  carries a pushing plate  8  at one end.  
         [0036]     The dispensing gun  1  of  FIG. 1  is utilized with a refill tube  11  illustrated in  FIG. 2  which has a first (nozzle) end  12  and a second (plunger) end  13 . The nozzle end  12  of the tube  11  is sealed by a nozzle cap  14  which consists essentially of a metal annulus  15  which is swaged or crimped to the nozzle end  12 . Glued to the interior of the metal annulus  15  is a circular sheet  16  of MYLAR which is provided with a cruciform cut  17  which functions as a nozzle. In order to seal the nozzle prior to dispensing, a circular tab  18  of metal foil is adhered to the exterior of the sheet  16  over the cut  17 . As indicated in  FIG. 2  the circular tab is removable so as to open the cut  17  and thereby permit the food sauce contained with the tube  11  to be dispensed.  
         [0037]     This dispensing action is carried out by pushing a plunger disc  21  along the tube axis. The plunger disc  21  is installed in the tube  11  after the tube has been filled with the sauce or other viscous liquid. The plunger disc  21  is made from plastic and metal and is pushed along the tube by the pushing plate  8  of the dispensing gun  1 .  
         [0038]     In accordance with a preferred embodiment of the present invention, both the nozzle cap  14  and the plunger disc  21  have equivalents manufactured from plastics material. These components are therefore substantially cheaper than the prior art nozzle cap  14  and plunger disc  21 .  
         [0039]     Turning now to FIGS.  3  to  11 , a plastics forcing disc  25 , which takes the place of the plastic and metallic plunger disc  21 , is illustrated. The forcing disc  25  is circular having a smooth flat base  26  and a stepped generally cylindrical side wall  27 . The side wall  27  is provided with an end flange  28  which mates with the plunger end  13  of the tube  11  and seals same prior to dispensing. The end flange  28  is supported by a thin portion  29  of the side wall  27 . The side wall  27  is also provided with a pair of annular sealing beads  30 ,  31  which seal the forcing disc  25  against the interior of the tube  11 .  
         [0040]     As best seen in  FIG. 11 , the forcing disc  25  is provided with six stiffening ribs  33  which extend from the centre of the forcing disc  25  radially outwardly and merge with the side wall  27  but do not engage the thin portion  29 . As best seen in  FIGS. 8 and 11 , the end flange  28  is provided with a multiplicity of notches  34  which are intended to deliberately weaken the end flange  28 . As best seen in  FIG. 10  the side wall  27  is stepped at  35  to provide a boss  36  of slightly reduced diameter which mates with the nozzle disc illustrated in  FIGS. 21-25 .  
         [0041]     It will be appreciated that after the plunger  11  has been filled with viscous liquid, the forcing disc  25  is placed into the plunger end  13  of the tube  11 . The sealing beads  30 ,  31  and the end flange  28  in combination seal the tube  11  and maintain the plunger ends  13  sealed until such time as dispensing is required.  
         [0042]     When dispensing is required, the tube  11  is placed in the gun  1  and the pushing plate  8  is brought to bear on the stiffening ribs  33 . The axial force of the pushing plate  8  is sufficient to urge the forcing disc  25  towards the nozzle end  12  of the tube  11 . This is accomplished by the notches  34  allowing the end flange  28  to buckle inwardly. This is assisted by the thin section of the thin portion  29  thereby permitting the end flange  28  to buckle and slide within the interior of the tube  11 .  
         [0043]     Tuning now to  FIGS. 12-25 , the prior art nozzle cap  14  is replaced by a nozzle assembly made up from an outer cover disc  41  ( FIGS. 12-20 ) and an inner nozzle disc  42  ( FIGS. 21-25 ). The cover disc  41  has a side wall  43  which is preferably glued to the interior of the tube  11  with an annular end flange  44  abutting the nozzle end  12  of the tube  11 . Radial stiffening ribs  45  extend between the side wall  43  and a circular, centrally located, frangible portion  46  defined by a circular groove  47 . The frangible portion  46  is provided with a hinged circular finger grip  48 . The finger grip  48  is able to be grasped by a finger of a user and pulled thereby rupturing the circular groove  47  and permitting the frangible portion  46  to be detached from the remainder of the cover disc  41 .  
         [0044]     As best seen in  FIG. 20 , the side wall  43  is provided with sealing beads  50 ,  51  and a tapered leading edge  52  which assists in insertion of the nozzle assembly into the nozzle end  12  of the tube  11 . The tapered leading edge  52  is also preferably longitudinally slotted (not illustrated) which enables the leading edge  52  to be compressed during the insertion procedure. If there is insufficient compression of the tube  11  by the sealing beads  50 ,  51 , then the cover disc  41  can be glued to the interior of the tube  11 .  
         [0045]     Turning now to the nozzle disc  42 , this is provided with a side wall  55  which is dimensioned to mate with the interior of the side wall  43  of the cover disc  41 . As best seen in  FIG. 23 , the nozzle disc  42  is very thin and has one or more cruciform cuts created during moulding, so as to form the nozzle or nozzles of the dispenser.  
         [0046]     The nozzle disc  42  fits snuggly within the interior of the cover disc  41  and as so assembled replaces the prior art nozzle cap  14 . The frangible portion  46  ensures that the cruciform cut(s) in the disc  42  are sealed until such time as dispensing is required. Furthermore, the profile of the nozzle disc  42  and the forcing disc  25  are essentially the same so that the forcing disc  25  and, in particular, the boss  36  thereof fits snuggly within the nozzle disc  42  when the forcing disc  25  is pushed fully into the tube  11 . In this way an absolute minimum of the dispensed viscous liquid is left remaining in the dispenser when dispensing is finally completed.  
         [0047]     The foregoing describes only one embodiment of the present invention and modifications, of this to those skilled in the art, can be made thereto without departing from the scope of the present invention.  
         [0048]     The term “comprising” as used herein is used in the inclusive sense of “having” or “including” and not in the exclusive sense of “consisting only of”.