Patent Publication Number: US-2007114228-A1

Title: Machine for producing and dispensing liquid and semi-liquid consumer food products

Description:
BACKGROUND OF THE INVENTION  
      The present invention relates to a machine for producing and dispensing liquid and semi-liquid consumer food products.  
      In particular, without limiting the scope of application, the present invention relates to pasteurizing machines, machines for cooking and preserving creams, jellies and sauces of various types, machines for producing and preserving ice cream, such as machines for “soft” ice cream, and similar products.  
      Machines of the type described above comprise a container or tank for the product processed, means for heating it, and if necessary for cooling it, and means for dispensing the product.  
      In order to make the temperature of the entire mass of product uniform during heating or cooling, there are also rotary stirring blades in the container.  
      In the prior art the heating means are of the resistive type and comprise an electric circuit which is closed as a spiral winding in the lateral walls and base wall of the container.  
      Heating means of this type are not only slow and uneven in their action, but also cause several disadvantages.  
      Firstly, if the container is not completely full the portion of its inner lateral surface above the level of the product assumes an extremely high temperature, with the consequent formation of crusts on it when it is hit by splashes caused by the action of the stirring blades.  
      Further disadvantages were found in the case in which the container must also house (for example in machines for producing ice cream) a cooling circuit, consisting of a pipe with a coolant flowing through it, made in the lateral walls and in the base wall of the container.  
      This limits the space available for the two circuits and means that their paths are extremely close together. As a result, the times for switching between the temperature reached during the heating step and a predetermined cooling temperature are extremely long due to the thermal inertia of the coolant pipe and of the container walls.  
     SUMMARY OF THE INVENTION  
      The aim of the present invention is therefore to overcome the above-mentioned disadvantages.  
      Accordingly, the present invention achieves this aim with a machine for producing and dispensing liquid and semi-liquid consumer food products which has the characteristics described in one or more of the claims herein. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The technical features of the invention, in accordance with the afore-mentioned aims, are clearly indicated in the claims herein and the advantages of the invention are more apparent in the detailed description which follows, with reference to the accompanying drawings, which illustrate a preferred embodiment without limiting the scope of the invention, in which:  
       FIGS. 1 and 2  are schematic views of two embodiments of a machine for producing and dispensing liquid and semi-liquid food products in accordance with the present invention;  
       FIG. 3  is an enlarged cross-section of a detail of  FIGS. 1 and 2 ;  
       FIG. 4  is a schematic perspective view of another embodiment of the machine in accordance with the present invention;  
       FIG. 5  is a schematic perspective view of another embodiment of the machine in accordance with the present invention;  
       FIG. 6  is a schematic side view of another embodiment of a detail of the machine in accordance with the present invention;  
       FIG. 7  is a schematic side view of another embodiment of a detail of the machine in accordance with the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      With reference to  FIG. 1 , the numeral  1  denotes as a whole a machine for producing and dispensing liquid and semi-liquid food products, for example a pasteurizing machine, for cooking and preserving creams and sauces of various types.  
      The machine  1  has a base  1   a  which substantially has the shape of a parallelepiped, inside which there is a container  2  for holding the product.  
      The container  2  comprises a tank  3  formed by vertical lateral walls  4  and a base wall  5 , and it extends according to a vertical longitudinal axis labeled  6 .  
      The container  2  also comprises, below the tank  3  and coaxial with it, at a circular opening  7  made in the base wall  5 , a cylindrical chamber  8 , formed by a cylindrical wall  9  and a base wall  10 .  
      Passing through the cylindrical chamber  8  and its base wall  10  there is a rotary shaft  11  coaxial with the axis  6  and extending in the tank  3 . The shaft  11  is motor-driven, at its lower end, by a motor schematically illustrated with a block  12  and the section of the shaft in the chamber  8 , and when required, also the section of the shaft in the tank  3 , supports blades  13 , forming the product stirring means.  
      At the opening  7  there is a lid  14  with a central hole for the shaft  11  to pass through and holes  15  to allow communication between the chamber  8  and the tank  3 .  
      The numeral  16  denotes a recirculating pipe connecting the chamber  8 , through the cylindrical wall  9 , and the tank  3 , through the base wall  5 .  
      The recirculating pipe  16  comprises a first, horizontal section  16   a  connected by a discharge pipe  17  to a dispensing nozzle  18  and a second, vertical section  16   b,  which has a curved end  19  in the tank  3 .  
      As well as functioning as stirring means, the blades  13  provoke a flow of product along the pipe  16  and therefore product circulation (clockwise in  FIG. 1 ) from the cylindrical chamber  8  to the tank  3 .  
      The recirculating pipe  16 , which as indicated is connected parallel with the container  2 , at its vertical section  16   b  has means for heating the product, these means labeled  20  as a whole.  
      More precisely, with reference also to  FIG. 3 , the heating means comprise an electricity source schematically illustrated as a block  21 , connected to a portion  22  of the section  16   b  made of a conducting material. The heating means  20  also comprise two more portions, upper  23  and lower  24  of the section  16   b,  also made of a conducting material, connected to the portion  22 , with two portions  25  and  26  made of an insulating material in between.  
      Therefore, said portion  22  constitutes a first electrode and the portions  23  and  24  two second electrodes, which being in contact respectively with the base wall  5  of the tank  3  and the section  16   a  of the recirculating pipe  16  are earthed.  
      Therefore, the action of the electricity source  21  results in the generation of a difference in potential between the electrode  22  and the electrodes  23  and  24 , with the consequent passage of electric current through the product which flows along the section  16   b  of the recirculating pipe  16 . In this way an ohmic-type dynamic heating device is created, in which the resistive load consists of the product itself rather than an external resistance.  
      The machine  1  illustrated in  FIG. 2  differs from the machine  1  in  FIG. 1  due to the fact that the heating means  20  are not at the recirculating pipe  16 , but at a pipe  27  extending parallel with the tank  3 . In this case there may be a pump  28  able to make the product flow along the pipe  27 .  
      Again as illustrated in  FIG. 2 , the heating means  20  may alternatively consist of a first electrode  29  in the tank  3  and a second electrode  30  coinciding with the tank  3  itself. In this case, unlike the one previously described, the heating device is of the static type.  
       FIG. 4  shows a machine for producing ice cream of the so-called “soft” type. The numeral  31  denotes the container for the liquid product used to obtain the ice cream and  32  denotes means for transforming the liquid product, comprising a “whipping and freezing” unit consisting of a cylindrical freezing container inside which there is a stirrer and connected to a refrigerating unit, of the known type and not illustrated. In the front part of the cylinder there is a tap  33  for extracting the ice cream.  
      The numeral  34  denotes an outfeed pipe from the container  31  connected, by a pump  35  and an infeed pipe  36 , to the cylinder  32  and the numeral  37  denotes a recirculating pipe which connects the cylinder  32  to the pipe  34  immediately upstream of the pump  35 .  
      The machine in  FIG. 4  also has heating means, labeled  20  as a whole, for heat-treating the product before each ice cream production cycle and also at the end of each cycle, so as to guarantee product preservation.  
      These heating means  20 , of the type illustrated in  FIG. 3 , may be positioned along the outfeed pipe  34 , along the recirculating pipe  37  and, as illustrated in the alternative embodiment in  FIG. 2 , they may be of the static type, that is to say having a first electrode  38  in the cylinder  32  and a second electrode  39  coinciding with a wall of the cylinder  32  itself.  
      The numeral  40  denotes a valve along the pipe  34  and inserted between the heating means  20  and the recirculating pipe  37  opening point; whilst  41  denotes a valve along the pipe  37 . The numeral  21  denotes the electricity sources all controlled by a central control unit illustrated with a block  42 .  
      It should be noticed that the heating means  20  may operate in combination with one another or separately.  
      Finally,  FIG. 5  shows a machine  1  for producing “soft” ice cream, which differs from the machine  1  in  FIG. 4  in that it has a tank  43  in place of the container  31 .  
      It should also be noticed that the heating means  20  may consist of a KIT unit  44 , which can be associated with the machine  1  using quick coupling—release means. For example, the KIT unit may be made as illustrated in  FIG. 3 , and may be inserted, for example, along the vertical section  16   b  of the recirculating pipe  16 .  
      The KIT  44  may be produced and sold separately from the machine  1  and may also be mounted on existing machines.  
      Finally, it should be noticed that, in accordance with the present invention, the heating means  20  do not consist of external electric heating elements, wound in a spiral in the lateral walls or the base wall of the container, but of electromagnetic means operating directly on the product accumulated in the tank or flowing along a pipe, causing an electric current to flow through the product, heating it rapidly and evenly.  
      As illustrated in  FIG. 6 , the heating means  20  may be of the inductive type and comprise an induction winding  45  positioned for example in the recirculating pipe  16 . Said winding  45 , connected to a generator of alternating current at a predetermined frequency  21 , by mutual inductance generates a magnetic field and therefore an electric current through the secondary, consisting of the product, which is heated as a result.  
      Finally, as shown in  FIG. 7 , the heating means  20  may comprise a microwave generator  46  powered by a power source  47  and positioned, for example, in the chamber  8  and acting directly on the product.  
      The electromagnetic wave generator  46  can operate in the radio frequency range.  
      The invention described has evident industrial applications and may be modified and adapted without thereby departing from the scope of the inventive concept. Moreover, all details of the invention may be substituted by technically equivalent elements.