WO2020025526A1

WO2020025526A1 - Cook top structure for induction stoves

Info

Publication number: WO2020025526A1
Application number: PCT/EP2019/070330
Authority: WO
Inventors: Claudio BERNABUCCI
Original assignee: Glass Company S.R.L.
Priority date: 2018-07-30
Filing date: 2019-07-29
Publication date: 2020-02-06
Also published as: EP3830488A1; BR112021001521A2; IT201800007602A1; BR112021001521B1

Abstract

Cook top structure for cooking induction stoves, of the type wherein the creation of an electromagnetic field for the flow of current around at least one coil induces parasitic currents which dissipate energy in form of heat in cooking pots arranged on a cook top, comprising fillings made of ferromagnetic material (8) associated beneath the cook top (6) for interacting with the cooking pots (7) not expressly conceived for induction heating.

Description

TITLE

COOK TOP STRUCTURE

FOR INDUCTION STOVES

DETAILED DESCRIPTION

Field of the art

Induction stoves consist of at least one coil around which an alternating electric current , which produces an electromagnetic field, alternating in turn, is made to flow.

The variation of the electromagnetic field attracts, in a discontinuous manner, the ferrous molecules (“magnetism” effect) generating a veiy rapid motion or an induced electromotive force (Faraday's law), which creates induced electric currents (so-called parasitic currents), which by means of a cook top, usually made of glass ceramic material, constituting the surface where the stove rests, circulate in the material of the containers arranged on the stove and dissipate energy in form of heat (Joule heating), causing the heating of the container and the food forming the content thereof.

In order to attain such results, or at least for the relative optimisation without wasting energy, appropriate cooking pots, made of ferromagnetic material and provided with a flat bottom, that are quite heavy and expensive, usually bearing a solenoid symbol at the bottom to indicate suitability for induction, are required.

According to the prior art (see e.g. DE 10 2008 007 191 A1) cooking pots not appropriate or poorly suitable for induction can be used on induction stoves by interposing a removable adapter or under-cooking pot ferromagnetic panel between the surface and the cooking pot, hence the induction heats the panel which in turn heats the cooking pot, but such solution is rather empiric and complex. In addition, such solution entails handling extremely hot discs, usually using tongs or engagement systems sold along with the actual discs.

Objects of the invention

In this context, a main object of the present invention is to provide an innovative structural and intentional concept that allows to use cooking pots and containers of any type, as long as they are resistant to heat, for cooking food in cooking induction stoves.

Another object of the present invention is to achieve the preceding object through an innovative concept that can be applied to pre-existing induction cookers and cookers not expressly designed to receive it.

Another object of the present invention is to achieve the preceding objects by means of an innovative concept that negatively impacts the functional, organoleptic, nutritional and aesthetic positive aspects of cooking induction stoves the least possible.

Still, a further object of the present invention is to achieve any one of the aforementioned objects through a device that is simple and effective, safe to use and relatively inexpensive considering the actual results attained therewith.

Summary of the solution concept

These and other objects are all attained by means of the cook top structure for cooking induction stoves according to the present invention as defined by the claims, of the type wherein the creation of an electromagnetic field for the flow of current around at least one coil induces parasitic currents which dissipate energy in form of heat in cooking pots arranged on a cook top, comprising fillings made of ferromagnetic material (8) associated beneath the cook top (6) for interacting with the cooking pots (7) not expressly conceived for induction heating.

Description of the attached drawings

Further characteristics and advantages of the cook top structure for cooking induction stoves according to the present invention shall be more apparent from the following detailed description of a preferred but non-exclusive embodiment thereof, represented solely by way of non-limiting example with reference to the two attached drawings, wherein: Figure 1 shows a sectional perspective view of a schematic embodiment of a cooking induction stove, accompanied by an embodiment of the cook top according to the present invention, partly sectioned.

Figure 2 shows a cross-section thereof.

Static description of the embodiment

With reference to such figures, and in particular to figure 1, indicated in its entirety with 1 is a schematic embodiment of an induction stove structure, consisting of a box-shaped element, indicated in its entirety with 2, of any type suitable for the puipose; for example of the type suitable to be assembled or integrated on a support usually a kitchen piece of furniture, at an operative height, or at the work plane of the neighbouring kitchen pieces of furniture even though the specific embodiment subject of illustration mainly refers to providing light portable stoves or that can be placed on any surface, as further outlined hereinafter.

Housed on the bottom of the box-shaped element 2 is a ferrite plate 3 and a discshaped coil 4 overlying it, connected to an electrical power supply grid in a known manner, with interposition of appropriate switches or potentiometers, according to the prior art.

Illustrated in the attached figures for the sake of simplicity is a single coil 4 in a box-shaped element 2, similar to a stove of the light or portable type, without prejudice to similarity to fixed installation induction stoves too, where the coils are almost always a plurality, usually four with varying diameter, so as to simultaneously allow the heating of several cooking pots of various sizes, and/or adapting the dimensions of the coil to the diameter of the cooking pot contingently used.

Even in induction stoves provided with a cook top structure according to the present invention the coils 4 can vary in number diversified per diameter, wherein the illustration of only one of them in the figures is provided for solely by way of example.

Shown with 5 is a schematic view of an electromagnetic field and shown with 6 is a cook top for induction stoves, usually and preferably made of glass ceramic material, illustrated above which is a cooking pot 7, to be considered of the common type, or not of the type with bottom made of ferrite or a type of surface designated or designed for cooking food on induction stoves. Applied beneath the cook top 6, at the coil 4, in any manner suitable for the purpose, for example by gluing and/or partial coupling, or even full embedding, in place in the thickness of the cook top 6, is a ferrite plate 8, disc-shaped in the described embodiment and substantially coaxial and with equal diameter with respect to the coil 4, for the purposes outlined hereinafter.

Dynamic description of the embodiment

Thus, having completed the static description of an embodiment of the cook top structure for induction stoves according to the present invention, following is the dynamic description of the same, i.e. the relative operation:

the operating principle is the same as for the induction stoves according to the prior art:

an alternating electric current , which produces an electromagnetic field 5, in turn of the alternating type, is made to flow around the coil 4;

the variation of the electromagnetic field attracts, in a discontinuous manner, the ferrous molecules (“magnetism” effect) generating a very rapid motion or an induced electromotive force (Faraday's law), which creates induced electric currents (so-called parasitic currents).

However, according to the invention the parasitic currents do not flow through the glass ceramic cook top 6, constituting a stove support surface, or rather, the innovation is conceived so that the actual feasibility does not depend on the parasitic currents that flow through the glass ceramic cook top 6, but rather on those that circulate in the plate 8 applied beneath the cook top 6 and dissipate the energy thereon in form of heat (Joule heating), thus causing the heating thereof.

The heating of the plate 8 is transferred through the cook top 6 to the container 7 and to the food contained therein.

The transmission of heat or thermal exchange between the two systems, occurs by means of conduction between the plate 8 and the container 7 and thus the container 7 does not necessarily need a bottom made of ferrite or need to be special in any manner whatsoever, given that it is the plate 8 under the cooking surface 6 that heats up and heats tile container 7, irrespective of the material it is made of, and the food contained therein. Alternative embodiments

It is obvious that in further alternative embodiments still falling within the solution concept subject of the embodiment illustrated above and claimed below, the cook top structure for induction stoves according to the present invention, may be implemented through equivalent technical and mechanical means, i.e. with further supplementary solutions, same case applying to all shapes of the relative components that can be varied to suit the purpose;

In particular, the induced ferrite plates under the cook top may come with various shapes, size and thickness, and be fixed in appropriate positions under the cook top adhering thereto in any manner whatsoever and in any manner suitable for the purpose.

Advantages of the invention

As clearly observable from the detailed description above of a preferred embodiment and as mentioned above regarding some embodiments, the cook top structure for induction stoves according to the present invention offers advantages corresponding to attaining the pre-set objects and others: as a matter of fact, it integrates a functional, modular and economic device that makes induction stoves applicable to any type of container without empiric interpositions and removal of adaptive accessories.

At the same time it maintains the advantages of cleanliness and organoleptic safeguarding typical of induction stoves; even though on the one hand it loses the advantage of protecting the hands against burning, rather relative protection in any case, on the other hand it acquires the advantage of being able to use any container, thus saving in terms of purchase or, at least, the need for continuous transfer, and relative cleaning operations, even when appropriate containers are available.

KEY TO REFERENCE NUMBERS

1 ) induction stove structure in its entirety

2 ) box-shaped element in its entirety

3 ) ferrite plate underlying the coil

4 ) coil

5 ) electromagnetic field 6 ) cook top made of glass ceramic

7 ) cooking pot

8 ) induced ferrite plate applied beneath the cook top

Claims

1) Cook top structure for cooking induction stoves, of the type wherein the creation of an electromagnetic field for the flow of current around at least one coil induces parasitic currents which dissipate energy in form of heat in cooking pots arranged on a cook top, characterised in that it comprises at least one layer made of ferromagnetic material or ferrite plate (8) associated beneath the cook top (6) relatively adhering thereto for interacting with the cooking pots (7) not expressly conceived for induction heating.

2) Cook top structure for induction stoves according to claim 1, of the type consisting of at least one coil (4) underlying a cook top (6), characterised in that beneath the cook top (6) adhering thereto and at said at least one coil (4) or each coil (4) in case of relative plurality, there is applied at least one ferrite plate (8).

3) Cook top structure for induction stoves according to any one of the preceding claims, of the type consisting of at least one coil (4) underlying a cook top (6) suitable to produce an alternating electromagnetic field (5) due to the effect of the flow of an alternating electric current around it, generating an induced electromotive force which creates parasitic currents, characterised in that beneath the cook top (6) adhering thereto and at said at least one coil (4) or each coil (4) in case of relative plurality, there is applied at least one ferrite plate (8) in which said parasitic currents flow causing the heating thereof which is transferred to the cooking pot (7) through the plate (6) by conduction.

4) Cook top structure for induction stoves according to any one of claims 1 to 3, characterised in that said at least one ferrite plate (8) applied beneath said cooking plate (6) is disc-shaped.

5) Cook top structure for induction stoves according to any one of claims 1 to 4, characterised in that said at least one ferrite plate (8) is applied beneath said cooking plate (6) in any fixed manner suitable for the purpose.

6) Cook top structure for induction stoves according to any one of claims 1 to 4, characterised in that said at least one ferrite plate (8) is applied beneath said cooking plate (6) partly or fully embedded in the thickness of the cooking plate

(6).