Patent Publication Number: US-2011069578-A1

Title: Beverage vending machine mixer

Description:
TECHNICAL FIELD 
     The present invention relates to a beverage vending machine mixer. 
     BACKGROUND ART 
     A beverage vending machine mixer normally comprises a hollow body with a mixing chamber inside, to which soluble material and water are fed through respective inlets. Downstream from the mixing chamber, the hollow body has a blending chamber that communicates with the mixing chamber and with a beverage outflow conduit, and houses a blending device normally comprising an impeller connected angularly to the output shaft of an electric motor. To enable thorough cleaning of the mixer by the operator, the impeller is normally connected removably the shaft. 
     Known systems currently used to connect the impeller removably to the shaft have the drawback of normally being fairly complicated in terms of assembly, which may often call for considerable accuracy on the part of the operator. The problem is obviously also further compounded by the mixer having to be cleaned relatively frequently, and often being located in a poorly illuminated part of the machine that is hard to reach. 
     DISCLOSURE OF INVENTION 
     It is an object of the present invention to provide a beverage vending machine mixer of the type described above, that is cheap and easy to produce and at the same time designed to eliminate the above drawbacks. 
     According to the present invention, there is provided a beverage vending machine mixer as claimed in claim  1  and preferably in any one of the Claims depending directly or indirectly on claim  1 . 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A non-limiting embodiment of the present invention will be described by way of example with reference to the accompanying drawings, in which: 
         FIG. 1  shows a section, with parts removed for clarity, of a preferred embodiment of the mixer according to the present invention; 
         FIG. 2  shows a larger-scale view in perspective of a detail in  FIG. 1 ; 
         FIGS. 3 and 4  show a side view and front view respectively of a detail in  FIG. 2 ; 
         FIG. 5  shows a section along line V-V in  FIG. 4 ; 
         FIG. 6  shows an exploded view of a detail in  FIG. 4  in two alternative configurations; 
         FIGS. 7 and 8  show sections along lines VII-VII and VIII-VIII in  FIG. 6  respectively; 
         FIG. 9  shows a rear view of  FIG. 6 . 
     
    
    
     BEST MODE FOR CARRYING OUT THE INVENTION 
     Number  1  in  FIG. 1  indicates as a whole a mixer for a beverage vending machine  2 . 
     Mixer  1  comprises a support  3  defined by a plate connected to a fixed wall  4  of machine  2  and facing a door (not shown) of machine  2 . 
     Mixer  1  also comprises a hollow mixing body  5  having a substantially vertical axis  6  and in turn comprising a top portion  7  defining a mixing chamber  8 ; a bottom beverage outflow conduit  9 ; and an intermediate portion  10  interposed between top portion  7  and outflow conduit  9 , an internally defining a blending chamber  11 . 
     More specifically, as shown in  FIG. 1 , top portion  7  is funnel-shaped with a top inlet  12  coaxial with axis  6  and normally positioned facing one or more known spouts (not shown) to receive metered quantities of soluble material from one or more known tanks (not shown). 
     Close to inlet  12 , top portion  7  has two water inlets defined by the outlets of two conduits  13  connected rigidly to top portion  7  and connected, by respective tubular fittings  14  integral with support  3 , to the delivery side of a known pump (not shown) to simultaneously or selectively feed water into mixing chamber  8 . 
     Just above conduits  13  and the free edge of inlet  12 , a steam suction opening  15  defines the outlet of a condensation cell (not shown in  FIG. 1 ) housed inside a pocket  16  of support  3  and connected to a suction circuit  17 . 
     With reference to  FIG. 1 , intermediate portion  10  is defined by an elbow-shaped member integral with top portion  7  and defining blending chamber  11 . At its free end facing support  3 , intermediate portion  10  comprises a cylindrical portion  18  connected to support  3  by a removable joint  19  and defining at the bottom the inlet of outlet conduit  9 , which extends frontwards of mixer  1  from cylindrical portion  18 , and is fitted with an outflow hose  20 . 
     Cylindrical portion  18  also defines a seat for an impeller  21  of a blender  22 , which serves to stir the mixture of soluble material and water from mixing chamber  8  to fully dissolve the material and supply a homogeneous beverage to outflow conduit  9 . 
     Impeller  21  is connected removably—as described in detail below—to a drive shaft  23 , which has an axis of rotation  24  perpendicular to wall  4 , extends inside blending chamber  11 , and defines the output of an electric motor  25  forming part of blender  22  and fitted to the opposite side of wall  4  from mixer  1 . 
     As shown in  FIGS. 2 ,  3 ,  7  and  8 , drive shaft  23  comprises a free-end portion  26  bounded laterally by two flat parallel faces  27  on opposite sides of axis  24 , and by two cylindrical faces  28 , which are coaxial with axis  24 , connect flat faces  27 , and each have a respective groove  29  lying, together with the other groove  29 , in a plane perpendicular to axis  24 . 
     As shown in  FIGS. 2 to 6 , impeller  21  comprises a central hub  30 , which has a through hole  31  engaged by end portion  26  of drive shaft  23 , and a disk  32  integral with hub  30  and bounded, on the side facing blending chamber  11 , by a flat annular surface  33  having a rounded free edge, and four radial grooves equally spaced about axis  24  to define four flat blades  34  on annular surface  33 . 
     As shown in  FIGS. 7 and 8 , hub  30  comprises a front portion  35  that projects axially from annular surface  33  towards blending chamber  11 , and is fitted on its free end with a circular flange  36  that projects radially outwards from front portion  35  and defines, in use, a user grip by which to grip impeller  21  to detach and refit it from and to drive shaft  23 . 
     With reference to  FIGS. 7 to 9 , hole  31  comprises a cylindrical inlet hole  37  coaxial with axis  24  and having a truncated-cone-shaped lead-in flare  38  for end portion  26 ; and a cross-shaped hole  39  which is coaxial with axis  24 , is connected to cylindrical hole  37  by a truncated-cone-shaped portion  40 , and defines two rectangular-section seats  41  coaxial with each other and with axis  24 , and each designed to receive end portion of drive shaft  23  in sliding and angularly fixed manner. 
     To lock hub  30  axially onto drive shaft  23 , impeller  21  comprises a click-on retaining device  42  comprising four teeth  43 , which are carried by flange  36  and each associated with a respective end of a respective seat  41 , so that, when impeller  21  is fitted onto drive shaft  23 , the teeth  43  associated with the seat  41  engaged by end portion  26  click into grooves  29 . For this purpose, as shown in  FIGS. 5 to 9 , teeth  43  face axis  24  and are each connected to the respective end of relative seat  41  by a respective elastically deformable rod  44  extending axially from flange  36  towards blending chamber  11 . 
     As shown in  FIG. 5 , each tooth  43  has a trapezoidal cross section, and is bounded externally by a face  45  sloping with respect to axis  24  by an angle of less than 90°, and which, when tooth  43  engages respective groove  29 , cooperates with a surface of groove  29  sloping at the same angle as face  45  and which, when impeller  21  is withdrawn axially from end portion  26  of drive shaft  23 , serves to flex relative rod  44  outwards and assist radial withdrawal of tooth  43  from groove  29 . 
     On the side facing flange  36 , each tooth  43  is bounded by a face  46  perpendicular to axis  24 , and which, when tooth  43  engages respective groove  29 , cooperates with a corresponding surface of groove  29  defining a shoulder to axially arrest impeller  21 . 
     To conclude, it should be pointed out that, when assembling impeller  21  onto end portion  26 , cross-shaped hole  39  allows the operator to fit hub  30  onto end portion  26  quickly and easily. 
     That is, regardless of the initial angular position of seats  41  with respect to flat faces  27  of end portion  26 , the operator is able to align one of the two seats  41  axially with flat faces  27  by rotating impeller  21  about axis  24  by an angle of always less than 90°. 
     In a variation not shown, cross-shaped hole  39  may be defined by more than two seats  41  coaxial with one another and with axis  24  and equally spaced about axis  24 . This provides, when assembling impeller  21 , for further reducing the angle by which hub  30  must be rotated by the operator to align a seat  41  axially with flat faces  27 .