Patent Publication Number: US-2021185775-A1

Title: An induction jug heater

Description:
FIELD 
     The present invention relates to induction heaters and more particularly but not exclusively to induction heaters to heat containers such as jugs. 
     BACKGROUND 
     Induction heaters employed in the food industry, include a plate upon which a container, that receives the food, is to rest. The plate includes an induction coil that is energised to heat the container, and therefore the food contained therein. 
     A disadvantage of the above discussed induction heaters is that considerable time is required to heat the container, and therefore the food contained therein. 
     OBJECT 
     It is the object of the present invention to overcome or substantially ameliorate the above disadvantage. 
     SUMMARY OF INVENTION 
     There is disclosed herein an induction heater for a container, the container having a base and an upwardly extending side, with the side and the base each being at least partly formed of ferromagnetic material, and at least partly enclosing a space to receive the container, the induction heater including: 
     a heater base including at least a portion of a base induction coil; 
     a heater side extending upwardly from the heater base and at least partly enclosing, with the base, a space to receive the container, the heater side including at least a portion of a side induction coil; and 
     connections to deliver an alternating current to both the coil portions so as to deliver to the space a magnetic field to cause heating of the container. 
     Preferably, the base coil is a complete coil and is wound so as to have a predetermined winding direction; 
     and the side induction coil is a complete coil and is wound so as to have a winding direction opposite the winding direction of the base coil. 
     Preferably, the heater side surrounds said space, and the side coil is wound so as to surround said space. 
     Preferably, the base induction coil is of a spiral configuration. 
     Preferably, the base induction coil is of a two-dimensional spiral configuration. 
     Preferably, the side induction coil is a three-dimensional spiral configuration. 
     In an alternative preferred form, the base induction coil portion and the side induction coil portion are coupled so as to be provided by a complete coil with windings, the windings including a winding portion provided by the heater base, and winding portions provided by the heater side. 
     Preferably, the winding portions provided by the heater side include inclined windings, inclined to the heater base. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       Preferred forms of the present invention will now be described by way of example with reference to the accompanying drawings wherein: 
         FIG. 1  is a schematic isometric view of an induction jug heater and a jug; 
         FIG. 2  is a schematic top plan view of the heater and jug of  FIG. 1 ; 
         FIG. 3  is a schematic sectioned isometric view of the heater and jug as shown in  FIG. 2  sectioned along the line  3 - 3 ; 
         FIG. 4  is a schematic isometric view of a modification of the heater and jug of  FIG. 1 ; 
         FIG. 5  is a schematic top plan view of the heater and jug of  FIG. 4 ; 
         FIG. 6  is a schematic sectioned isometric view of the heater and jug as shown in  FIG. 5  sectioned along the line  6 - 6 ; 
         FIG. 7  is a schematic isometric view of the heater and jug of  FIG. 4 , with an outer housing removed; 
         FIG. 8  is a schematic side elevation of the heater and jug as shown in  FIG. 7 ; 
         FIG. 9  is a schematic front elevation of the heater and jug as shown in  FIG. 7 ; 
         FIG. 10  is a schematic rear elevation of the heater and jug as shown in  FIG. 7 ; 
         FIG. 11  is a schematic bottom plan view of the heater and jug of  FIG. 7 ; 
         FIG. 12  is a schematic top plan view of the heater and jug of  FIG. 7 ; 
         FIG. 13  is a schematic isometric view of a modification of the heater and jug as shown in  FIG. 7 ; 
         FIG. 14  is a schematic side elevation of the heater and jug of  FIG. 13 ; 
         FIG. 15  is a schematic front elevation of the heater and jug of  FIG. 13 ; 
         FIG. 16  is a schematic rear elevation of the heater and jug of  FIG. 13 ; 
         FIG. 17  is a schematic bottom plan view of the heater and jug of  FIG. 13 ; and 
         FIG. 18  is a schematic top plan view of the heater and jug of  FIG. 13 . 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     In  FIGS. 1, 2 and 3  of the accompanying drawings there is schematically depicted an induction heater  10  to heat a jug  11 . The jug  11  includes a base  12  from which there upwardly extends a side  13 . Preferably the jug  11  has a handle  14  that extends laterally from the side  13 . 
     Preferably the side  13  is circular in transverse cross-section, and tapers upwardly from the base  12 . 
     The induction heater  10  includes an outer housing  15  that encloses a chamber  16 . Located in the chamber  16  is the electronic components for the heater  10 , including an electronic oscillator  17 . 
     The induction heater  10  includes a cavity  18  within which the jug  11  is located. 
     At least partly enclosing the cavity  18  is a cavity base  19  and a cavity side wall  20 . In this embodiment the cavity side wall  20  is generally circular in configuration, and is configured so as to be located relatively close to the jug side  13 . 
     The cavity base  19  includes a base induction coil  21  that includes a plurality of windings  22  that are generally located in a flat plane. The plane is generally horizontal, and the windings  22  extend angularly about a generally upright central axis  26 . The base induction coil  21  is of a two-dimensional spiral configuration. 
     The cavity side wall  20  includes a side induction coil  24  that includes a plurality of windings  25 . The windings  25  are wound about the axis  26  so as to be provided with a three-dimensional spiral configuration. 
     The axis  26  is generally upright, and generally perpendicular to the base  19 . 
     The base and side induction coils  21  and  24  are preferably formed by a single wire strand. 
     The base and induction coils  21  and  24  are connected to the electronic oscillator  17  so as to receive the alternating current therefrom. Preferably the oscillator  17  provides a high frequency alternating current. The base and side induction coils  21  and  24  are complete induction coils. 
     There is preferably located adjacent the cavity side wall  20 , and preferably adjacent the windings  25 , members  27 , located at equally spaced angular positions about the axis  26 , and that are elongated in the direction of the axis  26 . The members  27  aid in deforming the magnetic field produced by the coil  24  so as to be concentrated with respect to the jug  11 . The members  27  may be formed of ferromagnetic material or may be ceramic. 
     Preferably the base  19  is provided with members similar to the members  27 . 
     In the embodiment of  FIGS. 4 to 12 , the cavity  18  has an open side, so that the jug  11  may be inserted in the cavity  18  by horizontal movement in the direction  28 , that is a direction generally perpendicular to the axis  26 . In the embodiment of  FIG. 1 , the jug  11  is inserted in a downward vertical direction  29 , the direction  29  is generally parallel to the axis  26 . 
     In the embodiment of  FIGS. 4 to 12 , there is provided a complete coil  30 , the complete coil  30  includes the coil portion  31  provided by the cavity side wall  20 , and the coil portion  32  provided by the base  19 . The coil portion  31  includes winding portions  33  that extend to inclined winding portions  34 . The inclined winding portions  34  extending to winding portions  35 , providing the coil portion  32 , and are inclined to the base  19  by an acute angle. The complete coil  30  is formed by winding a single wire strand, that forms a single spiral winding. 
     In this respect it should be appreciated that the coil portions  31  and  32  cooperate to provide the complete coil  30 , with each winding portion  34  combining with respective winding portions  34  and  35  to provide a complete winding. 
     The housing  15  provides an end wall  36  (that provides the winding portion  33 ), as well as two side wall portions  37  (each providing a respective one of the winding portions  34 ), with the base  19  providing the winding portion  35 . 
     The complete coil  30  is connected to the electronic oscillator  17  as previously described. 
     Preferably the complete winding  30  is also operatively associated with metal members  27  as described with the previous embodiment. 
     In the embodiment of  FIGS. 14 to 18 , the side wall portions  37  are arcuate when viewed in top plan so that there is an entrance area  39 , that adjacent the floor  38 , is narrower than the width of the jug  11 . Accordingly, the jug  11  can be inserted in the cavity  18  in a direction that has a vertical component and a horizontal component. 
     The above described preferred embodiments have the advantage of providing a magnetic field that heats the jug base  12 , and at least portion of the jug side or sides  13 .