WO2008148397A1

WO2008148397A1 - Vessel for preparing, heating and cooling down of food

Info

Publication number: WO2008148397A1
Application number: PCT/DK2008/050137
Authority: WO
Inventors: Morten Riis
Original assignee: Riis Aps
Priority date: 2007-06-07
Filing date: 2008-06-06
Publication date: 2008-12-11

Abstract

In connection with the preparation, heating and cooling down of foodstuffs, use is often made of different vessels, all depending on which of the said processes are to be carried out with the foodstuffs. The reason for this is that the vessels which, for example, are used for preparation/heating, are often not suitable for use for e.g. freezing, partly as a consequence of reasons simply from the point of view of materials, and partly as a consequence of reasons regarding space. There is thus disclosed a vessel (2) which comprises a heat-conducting bottom (8), and which is characteristic in that the side wall (4) of the vessel consists of a silicone material known in connection with foodstuffs, and which is also known for use in connection with freezing, grilling, baking, frying, boiling, ovens and micro-ovens. There is hereby achieved a vessel with the flexibility necessary for it to be able to be used not only for the freezing down of foodstuffs, but also for heating with the known sources of heat. With the vessel being further provided with gripping elements (34, 34') which can be folded inwards, there is achieved the advantage that the vessel (2) does not take up unnecessary space, and moreover becomes stackable while occupying the least possible space.

Description

Title: Vessel for preparing, heating and cooling down of food.

The present invention relates to a vessel for preparing, heating and cooling down of food, and comprising a bottom suitable for use together with hotplates, glass-ceramic hotplates, halogen hotplates, gas burners and induction cookers, ovens and micro-ovens, where extending upright from the periphery of said bottom and tightly-fitting/moulded together with said periphery there is an annular, vertical side wall with an annular outer periphery which forms the edge of the vessel, said side wall in combination with the bottom forming the vessel.

Such vessels are typically found as commonly-known cooking pots which, however, are not particularly suitable in connection with long-life cooling down of foodstuffs to below freezing point, as it can hardly be avoided that the pots suffer damage in the freezing down of foodstuffs, in that the freezing down causes the foodstuffs to expand, which can give rise to deformation of the pot as well as deformation of the bottom of the pot so that it is no longer plane, which is important when this shall be used on plane cooking surfaces, but this is not important if the pots are intended for use on induction cookers. Moreover, the side wall of the known cooking pots comprises projecting, heat-insulating handles, with the result that a pot which is used as a vessel for the freezing of prepared foodstuffs will occupy a disproportionally great amount of space in a freezer which is often already tightly packed. The presence of said handles also often means that the pot can not be used in an oven for the heating of the frozen food, because the material from which the handles are made does not tolerate repeated long-time heating in an oven immediately after having been taken from the freezer, this being a consequence of the material of which the handles are manufactured being made brittle by the great and relatively sudden variations in temperature. Moreover, pots of metal will often not be able to be used in micro-ovens, in that the micro-oven's magnetron will be ruined. However, there are some special steel types which will be able to be used with micro-ovens.

There are also known vessels of plastic which are suitable for the freezing down of foodstuffs, and which can also be used in connection with the defrosting/ heating of the frozen food in micro-ovens. However, these plastic vessels are hardly suitable for the heating of foodstuffs in ovens or on hotplates and the like, since the very strong influence of the heat from a hotplate will result in damage to/melting of the plastic. The plastic vessels distinguish themselves from the cooking pots by not having handles extending from the side walls which result in inex- pedient occupation of space in a freezer, and said plastic vessels are often stack- able, so that when that are not used for the storage of foodstuffs they can be stored without unnecessarily taking up much space.

There are also known roasting pans of metal which can similarly be used in the cooling down/freezing of foodstuffs, and which are suitable for use together with ovens in connection with the heating of food. However, said roasting pans hardly find use in connection with hotplates etc.

It is the object of the invention to provide a vessel of the kind disclosed in the preamble which can also be stored while occupying the least possible space, which is able to be used in connection with the preparation, cooling down/freezing of foodstuffs, and which can also be used as ordinary cooking pots for heating on hotplates, glass-ceramic plates etc. in ovens and micro-ovens, without the vessel suffering damage by the relatively great and sudden changes in temperature between the frozen and the heated state.

This object is achieved with a vessel of the kind disclosed in the preamble, which is characterised in that the upright side wall consists of a silicone material known for use in connection with foodstuffs, and which is also known for use in freezing, grilling, baking, roasting, boiling, ovens and micro-ovens.

There is hereby achieved a vessel with sides which allow the expansion necessary in connection with the cooling/freezing of foodstuffs placed inside the ves- sel, inasmuch as the polymeric material has the flexibility necessary for this purpose. Furthermore, the material can withstand the suddenly arising temperature change which occurs with heating on hotplates, in ovens, micro-ovens etc. immediately after the vessel has been taken from the freezer.

With the object of ensuring that the edge of the vessel has a certain rigidity, the side wall near the edge can comprise an encircling ring of stiff or partly stiff material known for use in connection with foodstuffs, placed in the silicone material and as further known for use in freezing, grilling, baking, roasting, boiling, ovens and micro-ovens, so that a flange is formed along the edge. It is hereby ensured that the vessel retains its form stability when being handled.

With the object of further stabilising the vessel, the side wall between the bottom and the edge can comprise at least one encircling ring, and in a substantially horizontally oriented stay and evenly distributed over the extent of the side wall, of stiff or partly stiff material known for use in connection with foodstuffs and also known for use in freezing, grilling, baking, roasting, boiling, ovens and micro- ovens, placed in the silicone material.

With the object of providing expedient storage conditions and the saving of energy during the heating of foodstuffs in the vessel, this can further comprise a flexible lid consisting of a silicone material known in connection with foodstuffs, and which is also known for use in freezing, grilling, baking, roasting, boiling, ov- ens and micro-ovens, said lid having an extent and shape which at least corresponds to the facing side of the vessel's edge, and near its side wall said lid comprises an annular recess with a geometry corresponding to that part of the vessel's edge with which the recess is in contact. There is hereby achieved a tightly- fitting vessel which is stackable in a freezer, and which at the same time can be used as a cooking pot with lid.

With the object of ensuring the venting of vapour/steam which arises during the use of the vessel for the preparation, heating/boiling/roasting etc. of foodstuffs in the vessel, on the side opposite the annular recess the lid can comprise a num- ber of protruding, foldable gripping elements, which also have the characteristic that, by being folded towards the annular recess, these will be brought into contact on the edge/inner side of the vessel^'s side wall and create a space between the lid and the edge of the vessel. The spacing hereby provides the opening necessary for the venting of vapour/steam from the inside of the vessel.

With the object of being able to control the contents of the vessel, for example during the heating of food which is placed inside the vessel, the lid can further comprise an opening which is covered by a transparent material enclosed within the opening.

With the object of being able to handle the vessel in an easy and convenient manner, and such that the vessel is in balance when being handled, the vessel can comprise an associated, removable, flexible, hoop-shaped carrying handle, the free ands of which comprise bent parts for cooperating engagement with the subtending extent of the flange along the edge of the side wall. There is hereby achieved the same possibility for handling of the vessel as with commonly-known buckets. With the object of ensuring that the vessel can be used in micro-ovens, the bottom can consist of a magnetic, sandwich-metal material comprising a combination of aluminium and stainless steel.

With the object of ensuring that the vessel can be produced in one working operation, and so that in addition to being able to be used together with hotplates, glass-ceramic heat zones, halogen hotplates, micro-ovens, ovens and induction hotplates, the bottom can consist of a silicon material known for use in connection with foodstuffs, and which is further known for use in freezing, grilling, baking, fry- ing, boiling, ovens and micro-ovens, mixed with a magnetic material, said bottom being moulded together with the side wall. The vessel will hereby be able to be produced in one working operation, while at the same time the magnetic material in the bottom ensures good heat conduction characteristics.

In a special embodiment of the vessel according to the invention, particularly suitable for use together with induction hotplates, the bottom can consist of a silicone material known for use in connection with foodstuffs, and which is also known for use in freezing, grilling, baking, frying, boiling, ovens and micro-ovens, and the bottom can further comprise a loose, independent element of magnetic material/silicone material known for use in connection with foodstuffs, and which is also known for use in freezing, grilling, baking, frying, boiling, ovens and micro- ovens, chiefly with a plate-shaped form with at least one side surface which is flat for bringing into contact with the inside surface of the bottom of the vessel.

There is hereby achieved the advantage that the weight of the vessel is reduced when this is used for storage of, for example, foodstuffs which shall not subsequently be heated on induction cookers. This naturally requires that a decision is made regarding how a possible subsequent heating-up of the foodstuff is to take place before it is placed in the vessel. However, the vessel will thus be able to function both as an ordinary vessel suitable for use together with micro-ovens, and as an ordinary cooking pot, merely by the placing of the loose element of plate- shaped magnetic material inside the vessel.

It is preferred that the loose element of plate-shaped magnetic material for placing inside the vessel has the same size and shape as the bottom of the vessel, so that it is in contact with the bottom of the vessel. However, in this connection it shall be mentioned that elements of plate-shaped magnetic materials, whose size and geometry are respectively smaller/and have a geometry which deviates in relation to the vessel^'s bottom surface, are also able to be used in connection with induction hotplates, merely providing that they can be accommodated in the vessel so that the one flat side is in contact with the bottom of the vessel.

With the use of plate-shaped elements of magnetic material which are of a size which is less than that of the bottom of the vessel, there is achieved a lesser intensity of the heat induced in the foodstuff inside the vessel. Moreover, a greater flexibility is achieved with regard to the use of the elements of plate-shaped mag- netic material.

With the object of ensuring the possibilities for a good hygienic standard in connection with the use of the vessel, it is further preferred that the plate-shaped element of magnetic material has a surface which is easy to clean.

In a special embodiment, the plate-shaped element of magnetic material can be provided with a non-adhering, easy-slip coating, for example a coating of Teflon®.

Without renouncing the right for the utilisation of other materials, it can be further mentioned that the shape of the encircling ring and stiff or partly stiff stay, known for use in connection with foodstuffs, placed in the silicone materials and as further known for use in freezing, grilling, baking, frying, boiling, ovens and micro- ovens, in the side wall near the edge, is adapted to the geometry of the side wall.

With the object of ensuring possibilities of handling the vessel in the same way as an ordinary cooking pot, the side wall on the external side of the vessel can comprise handles on diametrically opposite locations, where said handles can assume a folded-in neutral position plane with the surface of the side wall, and a folded-out position where the handle is protruding from the surface of the side wall. There is hereby achieved the additional advantage that a plurality of vessels according to the invention can be stacked on top of one another, with reduced occupation of space in comparison with known vessels, where the protruding handles on the known vessels place limitations on the degree to which these can be low- ered into one another.

In the following, the invention is explained in more detail with reference to the drawing, where Fig. 1 is a perspective view of an embodiment of a vessel for preparation, heating and cooling down foodstuffs according to the invention, where the side wall is shown transparent, Fig. 2 shows the same as in fig. 1 , but as a line drawing,

Fig. 3 is a side view of an embodiment of the lid associated with the vessel,

Fig. 4 is a perspective view of an embodiment of a carrying handle associated with the vessel,

Fig. 5 is a sectional perspective view of the embodiment of the vessel ac- cording to the invention shown in fig.1 seen at an angle from the front,

Fig. 6 is a detail view of the edge of the vessel according to the invention, with the carrying handle shown in fig. 4 inserted into engagement with a flange on the edge of the vessel,

Fig. 7 is a sectional view of the embodiment of the vessel according to the in- vention shown in fig. 1,

Fig. 8 is a perspective view of a plurality of the vessels according to the invention shown in fig. 1 - 7, inserted into one another for storage,

Fig.9 is a perspective view of an embodiment of a vessel for preparation, heating and cooling down of foodstuffs according to the present invention, shown in a special embodiment for use together with induction hotplates, immediately before the insertion of a plate-shaped element of magnetic material,

Fig. 10 shows the same as in fig. 9, but where the plate-shaped element of magnetic material is placed down in contact with the bottom of the vessel, and

Fig.11 is a cross-sectional view of the vessel shown in fig. 10.

Fig. 1 and Fig. 2 respectively show a perspective view and a line drawing of a first embodiment of a vessel 2 for heating and cooling down of foodstuffs according to the invention. The vessel comprises a side wall 4 which consists of a foodstuffs-approved, flame resistant, heat resistant, polymeric material, which is tightly-fitting to and standing upright from the periphery 6 of a plane bottom 8, which in the shown embodiment consists of a sandwich bottom of aluminium and steel.

For the sake of clarity, the side wall 4 is shown transparent. On the edge 10 of the side wall there is placed a flexible lid 12 which is associated with the vessel 2 and has a circular cut-out 14 in which there is housed a piece of transparent material 16 which enables a visual control to be made of the state of the foodstuff (not shown) which may have been placed in the cavity 18 of the vessel. The polymeric material which comprises the side wall 4 offers sufficient flexibility for the vessel to be able to be used in connection with the freezing-down of foodstuffs, the material having an elasticity which enables the expansions which occur in the foodstuff, which will typically be hydrous, to be accommodated by the side wall 4 without these causing damage to the wall. Moreover, the polymeric material also has heat-insulating characteristics which enable the vessel to be handled after heating of the foodstuff without the use of pot holders. The polymeric material is also heat resistant to such a degree that it is able to be used together with hotplates, glass-ceramic heating surfaces, halogen hotplates, gas burners and induction cookers and microwave ovens.

Along the edge 10, the side wall 4 comprises an encircling ring (not shown) of stiff, or partly stiff, heat-resistant, foodstuffs-approved material placed in the polymeric material, so that along the edge 10 there is formed a flange 20. The flange 20 is seen more clearly in figs. 5 and 6, which respectively are a sectional view of the vessel 2 according to the invention and a detail view of a section of same at the edge 10 of the side wall 4.

As also appears from fig. 1 and fig. 2, the vessel further comprises an associated, removable, flexible, bow-shaped carrying handle 22, cf. fig. 4, the free ends 24, 26 of which comprise bent-over parts 28, 30 for cooperating engagement with oppositely-facing sections of the flange 20 along the edge 10 of the side wall 4. The flexibility of the carrying handle 22 makes it possible for the handle to be used for vessels 2 according to the invention where these are of different diameters. This means that just one carrying handle 22 for one set of vessels 2 with different diameters, for example as shown in fig.7, is sufficient to be able to handle all vessels 2 individually, where with vessels of larger diameter the carrying handle 22 is pressed slightly closer in towards the lid 12 for the accommodation of the bent- over parts 28, 30 in engagement with the flange 20 along the edge 10 of the side wall 4.

As will appear further from fig. 1 and fig. 2, but more clearly in fig.5 and fig.7, the outside 32 of the side wall 4 of the shown embodiment of the vessel 2 accord- ing to the invention comprises grips 34, 34'on diametrically opposite sides, where said grips in the shown embodiment are seen to assume a folded-in neutral position flush with the outer side 32 of the side wall 4. The grips 34, 34^' consist of "flaps" or ears, typically of the same material as the side wall 4, which are moulded together with the wall in a semi-circular recess 36, 36'in the outside 32 of the side wall 4. The moulding together is typically carried out in the horizontally-oriented, part 38, 38'of the semi-circular recesses 36, 36'. In the side wall opposite the horizontally-oriented parts 38, 38^'of the semi-circular recesses 36, 36^', the grips 34, 34' also have upwardly-curved depressions 40, 40^' to ease access to the grips 34, 34'. The grips 34, 34' will thus easily be able to be gripped and moved to a folded- out position (not shown), where they are standing out from the surface 32 of the side wall 4 in such a manner that the vessel 2 can be handled and carried by the grips.

Here it shall already be mentioned that the inventor has acknowledged that the grips can be of configurations other than that shown in the drawing and as described above, but the advantage of this manner of configuring the grips 34, 34' as inwardly and outward ly-foldable elements is that vessels 2 according to the inven- tion will be able to be stacked as appears most clearly from fig. 8, which shows how three vessels 2, 2', 2^" are inserted into one another, and it appears quite clearly how little space these will occupy in a cupboard or a drawer intended for storage boxes, cooking pots and frying pans etc.

As will also appear from fig. 1 , fig. 2 and fig. 3, as already disclosed the vessel 2 according to the invention comprises a flexible lid 12 which consists of a foodstuffs-approved, flame resistant, heat resistant, polymeric material, and which has an extent and shape which corresponds at least to the side facing towards the edge 10 of the vessel. Near its side wall the lid 12 comprises an encircling recess 44 with a geometry which corresponds to that part of the edge 10 of the vessel, namely the flange 20, with which the recess 44 is in contact, There is hereby achieved a good tight fit between the vessel 2 and the lid 12.

As will also appear from fig. 1 , fig. and fig. 3, on the side opposite the encir- cling recess 44, the lid 12 comprises a number of protruding gripping elements 46 which are characterised in that they can be bent over to a position where they are oriented towards the encircling recess 44. When the vessel is used for the heating of foodstuffs (not shown) inside the vessel, it will thus be possible to create a space (not shown) in between the edge 10 of the vessel's side wall 4 by bending one or more of the gripping elements 46 to a position where these are oriented in towards the recess 44, and place the lid over the vessel 2, inasmuch as the gripping elements 46 will be brought into contact with the edge 10 of the side wall 4 and create said space between the lid 12 and the edge 10 of the vessel. It shall be mentioned that the shown bottom 8 consists of a sandwich metal bottom consisting of a combination of aluminium and stainless steel.

In a second not-shown embodiment, the bottom 8 can be of a composite material consisting of a foodstuffs-approved, flame resistant, heat resistant, polymeric material mixed with a magnetic material, said bottom being moulded together with the side wall. The vessel can hereby be produced in one working operation, while at the same time it will continue to have the same possibilities of application as the embodiment comprising the sandwich metal bottom.

In fig. 9 there is shown a perspective view of a third embodiment of a vessel 2 for preparing, heating and cooling down of foodstuffs according to the present invention. The special aspect of this embodiment is that it is particularly suitable for use together with induction hotplates, inasmuch as this embodiment comprises a plate-shaped element 48 of magnetic material which, in fig.9, is seen immediately before being placed inside the vessel, so that the first plane side surface 50 of the plate-shaped element 48 of magnetic material is brought into contact with the bottom 8 of the vessel, as will appear from fig. 10, which is a perspective view of the vessel 2 shown in fig.9, where the plate-shaped element 48 of magnetic material is inserted, and fig. 11 which is a cross-sectional view of the vessel 2 shown in fig. 10.

By the placing of the plate-shaped element 48 of magnetic material inside the vessel 2, it is achieved that a magnetic "core" is created which, when the vessel 2 is placed with its bottom 8 standing on an induction hotplate (not shown), and upon the switching on of a relevant induction hotplate, will conduct heat to the contents of the vessel.

It is preferred that the plate-shaped element 48 of magnetic material has a surface which provides optimum conditions for achieving a food hygiene, which is to say that the plate-shaped element 48 can be coated with a easy-slip, non- adhering coating, for example a coating of Teflon^®.

It shall further be mentioned that the second side 52 of the plate-shaped element 48 of magnetic material does not necessarily have to be plane. Such a surface could, for example, be configured with corrugations of with ridges or the like, or with one or more upstanding parts inside the cavity 18 of the vessel, with the object of increasing the contact surface between the plate-shaped element and the foodstuff or other material which shall be heated by means of an induction hot- plate.

As already disclosed, without renouncing the right to utilise other materials, it can be mentioned that a preferred material for the execution of the side wall 4 consists of silicone rubber. This material has the advantage that it can be injection moulded and that it is available in several colours.

It is further preferred that the encircling ring and stay (not shown) of stiff or partly stiff, heat resistant, foodstuffs-approved material in the side wall near the edge consist of a thermoplastic polyester (PET), the shape of which is adapted to the geometry of the side wall.

In conclusion it shall be mentioned that the inventor has acknowledged that the vessel 2 according to the invention can assume many other configurations than that shown and described in the above. However, this does not detract from the innovative aspect, which consists of the creating of a vessel which has the same advantageous characteristics as a cooking pot in connection with the heat- ing/preparation of foodstuffs on hotplates, glass-ceramic hotplates, halogen hotplates, gas burners and induction cookers, ovens and microwave ovens, as a frying or roasting pan, which can also be used as a minimal-space-demanding storage container in connection with the cooling/freezing of foodstuffs, and which can also be stored while occupying a minimum of cupboard/shelf space.

Claims

1. Vessel (2) for preparing, heating and cooling down of foodstuffs, and comprising a bottom (8) suitable for use together with hotplates, glass-ceramic cooking surfaces, halogen hotplates, gas burners and induction cookers, ovens and micro- ovens, where from the periphery of and standing upright from said bottom there is a tight-fitting/moulded together side wall (4) with an annular upper periphery which forms the edge (10) of the vessel (2), said side wall (4) together with the bottom (8) forming the vessel (2), c h a r a c t e r i s e d in that the upright side wall (4) consists of a silicone material known for use in connection with foodstuffs, and further known for use in freezing, grilling, baking, frying, boiling, ovens and micro- ovens.

2. Vessel (2) for preparing, heating and cooling down of foodstuffs according to claim 1 , c h a r a c t e r i s e d in that the side wall (4) near the edge (10) comprises an encircling ring of stiff or partly stiff material known for use in connection with foodstuffs, and further known for use in freezing, grilling, baking, frying, boiling, ovens and micro-ovens, placed in the silicone material, so that a flange (20) is formed along the edge (10).

3. Vessel (2) for preparing, heating and cooling down of foodstuffs according to claim 2, c h a r a c t e r i s e d in that between the bottom (8) and the edge (10), the side wall (4) comprises at least one encircling ring, and a substantially horizontally-oriented stay evenly distributed over the extent of the side wall, of stiff or partly stiff material known for use in connection with foodstuffs, and as further known for use in freezing, grilling, baking, frying, boiling, ovens and micro-ovens, placed in the silicone material.

4. Vessel (2) for preparing, heating and cooling down of foodstuffs according to any of the claims 1-3, c h a r a c t e r i s e d in that it further comprises a flexible lid (12) which consists of a silicone material known for use in connection with foodstuffs, and as further known for use in freezing, grilling, baking, frying, boiling, ovens and micro-ovens, said lid having an extent and shape which at least corre- sponds to that on the side facing towards the edge of the vessel, and where said lid near its side wall comprises an annular recess (44) with a geometry which corresponds to that part (20) of the edge (10) of the vessel with which the recess is in contact.

5. Vessel (2) for preparing, heating and cooling down of foodstuffs according to claim 5, characterised in that the lid, on the side opposite the annular recess (44), comprises a number of protruding gripping elements (46) which can be bent over, and which also have the characteristic that when these are bent over towards the annular recess (44), they will be brought into contact with the edge (10, 20)/ the inside of the vessel^'s side wall (4) and create a space between the lid (12) and the edge (10) of the vessel.

6. Vessel (2) for preparing, heating and cooling down of foodstuffs according to the claims 1-5, characterised in that the lid (12) further comprises an opening (14) which is covered by a transparent material (16) enclosed within the opening (14).

7. Vessel (2) for preparing, heating and cooling down of foodstuffs according to any of the claims 1-6, characterised in that the vessel (2) comprises an associated, removable, flexible, bow-shaped carrying handle (22), the free ends (24, 26) of which comprise bent parts (28, 30) for cooperating engagement with opposite sections of the flange (20) along the edge (10) of the side wall (4).

8. Vessel (2) for preparing, heating and cooling down of foodstuffs according to any of the claims 1-7, characterised in that the bottom (8) consists of a magnetic sandwich-metal bottom consisting of a combination of heat-conducting aluminium and stainless steel known for use in connection with foodstuffs, and as further known for use in freezing, grilling, baking, frying, boiling, ovens and micro- ovens.

9. Vessel (2) for preparing, heating and cooling down of foodstuffs according to any of the claims 1-7, characterised in that the bottom (8) consists of a silicone material known for use in connection with foodstuffs, and as further known for use in freezing, grilling, baking, frying, boiling, ovens and micro-ovens, said silicone material being mixed with a magnetic material known for use in connection with foodstuffs, and as further known for use in freezing, grilling, baking, frying, boiling, ovens and micro-ovens, and where said bottom is moulded together with the side wall (4).

10. Vessel (2) for preparing, heating and cooling down of foodstuffs according to any of the claims 1-7, characterised in that the bottom (8) consists of a silicone material known for use in connection with foodstuffs, and that the vessel (2) further comprises a loose, independent .mainly plate-shaped element of magnetic material known for use in connection with foodstuffs, and as further known for use in freezing, grilling, baking, frying, boiling, ovens and micro-ovens, at least the one side surface of which is plane for placing into contact with the inside surface of the bottom of the vessel.

11. Vessel (2) for preparing, heating and cooling down of foodstuffs accord- ing to claim 10, characterised in that the loose, independent element of magnetic material has more or less the same size and geometry as the bottom of the vessel.

12. Vessel (2) for preparing, heating and cooling down of foodstuffs according to claim 10, characterised in that the loose, independent element of magnetic material has a size and geometry which is relatively smaller than that of the bottom of the vessel, and which in relation to the bottom surface of the vessel has a deviating geometry, but though with a geometry which is accommodated in the geometry of the vessel, so that the one flat side is in contact with the bottom of the vessel.

13. Vessel (2) for preparing, heating and cooling down of foodstuffs according to any of the claims 10-12, characterised in that the side of the loose, independent element of magnetic material opposite the plane side for contact against the bottom of the vessel is corrugated and/or has at least one upright part.

14. Vessel (2) for preparing, heating and cooling down of foodstuffs according to any of the claims 10-13, characterised in that the loose, independent element of magnetic material has a surface which is easy to clean.

15. Vessel (2) for preparing, heating and cooling down of foodstuffs according to any of the claims 10-12, characterised in that the loose, inde- pendent element of magnetic material is provided with a non-adhering, slip-easy coating, for example a coating of Teflon^®.

16. Vessel (2) for preparing, heating and cooling down of foodstuffs according to any of the claims 1 -15, characterised in that the shape of the encircling ring and stay of stiff or partly stiff material, known for use in connection with foodstuffs, and as further known for use in freezing, grilling, baking, frying, boiling, ovens and micro-ovens, in the side wall near the edge is adapted to the geometry of the side wall.

17. Vessel (2) for preparing, heating and cooling down of foodstuffs according to any of the claims 1 -16, characterised in that the outside surface (32) of the side wall (4) of the vessel (2) comprises gripping elements (34, 34') on diametrically opposite locations, and said gripping elements (34, 34^') can assume a folded-in neutral position flush with the outside surface (32) of the side wall (4), and a folded-out position of use where the elements (34, 34^') are standing out from the outside surface (32) of the side wall (4).