The invention relates to the asymmetric structure, in terms of the layer structure, of two or more stone slabs—generally two—wherein the load-bearing bottom slab is designed to be thicker than the top slab which is to be stabilized and which forms the surface of an induction hob assembly. The thickness or stiffness of the bottom stone slab is designed in conjunction with an adequately dimensioned tension-resistant fibre layer such that the tensile stresses in the top slab resulting from the expansion of the top slab during cooking, especially on the surface, because of the bi-metal effect, that is to say from dishing up of the slab, are not exceeded to avoid any hairline crack formation. To this end, the cross-section and/or the stiffness of the bottom slab is to be designed to be so thick in the counter-stabilizing edge regions that the expansion forces of the top stone slab in the cooking zone are adequately compensated for by the compression zone beneath the tension-resistant fibre layer such that the maximum permissible tensile stress on the surface of the top stone slab, which makes up the hob, is not exceeded even if the maximum permissible cooking temperature is reached. In order to prevent deflection or dishing of the entire assembly as a result of the bi-metal effect, a sufficiently porous stone material is selected for the surface which is compressible in volume and/or preferably less resistant to compression than the bottom stabilizing slab, which provides the counter-pressure. To receive the induction coil, the slab assembly is milled out from below to close to the surface, so that the distance between the induction coil and the pan is as small as possible. The milled-out portion is designed to be domed to enhance mechanical stability against pressure and impact from above. Additional fibre reinforcement can be applied here to provide greater support. Circulating air layers are used beneath and, where necessary, on top of the stone surface to keep the surface temperatures on the hob and on the underside of the cooking zone as low as possible. These measures together serve the purpose of preventing the usual hairline cracking on the surface of the complete assembly.

An induction heating type cooktop includes a cover plate that is coupled to a top of a case and that includes an upper plate configured to seat an object to be heated, a working coil disposed inside the case and configured to heat the object, an insulator disposed between a bottom surface of the upper plate and the working coil, and a thin film that is disposed on at least one of a top surface of the upper plate or the bottom surface of the upper plate and that includes a plurality of sub-films that are arranged about a central portion of the thin film. An outer boundary of one of the plurality of sub-films is positioned radially outward of an outer boundary of another of the plurality of sub-films relative to the central portion of the thin film.

An inductive cooking combined shield configured to be arranged below a cooking coil winding may include a plurality of ferrite bars and a plurality of elements made of a second material alternatively arranged in a plane so that to create a complementary electromagnetic shielding that extends from the center of the coil to the perimeter and has a modular structure that allows to block and/or to mitigate undesired macro eddy currents generated by the electromagnetic flux produced by the current flowing inside the winding.

An induction heating device includes: a working coil including a conducting wire that is wound in an annular shape and that is connected to a plurality of electric terminals; a ferrite core disposed vertically below the working coil and configured to direct upward an alternating magnetic field generated by the working coil, the ferrite core defining a stepped portion at each corner of the ferrite core; a base plate that supports the ferrite core on an upper surface of the base plate and that defines a connection hole having a shape corresponding to the corner of the ferrite core; and an indicator substrate disposed vertically below the base plate. The indicator substrate includes a connector that is disposed on an upper surface of the indicator substrate, that is coupled to one or more of the plurality of electric terminals, and that protrudes upward through the connection hole.

Disclosed is an article for use with an apparatus for heating smokable material to volatilize at least one component of the smokable material. The article includes a carrier having plural thermally-conductive portions, on which are locatable respective discrete quantities of smokable material. Between the portions of the carrier, the carrier is shaped to form a thermal barrier for inhibiting heat conduction from one or more of the portions of the carrier towards another of the portions of the carrier in use.

Induction cooker having an induction coil, a supporting structure, a ferromagnetic element and a non-ferromagnetic element. The induction coil is arranged to receive a varying electric current and produce a corresponding varying electromagnetic field. The supporting structure is arranged to support a ferromagnetic object above the induction coil, the ferromagnetic object being placed in the corresponding varying electromagnetic field to be magnetically coupled to the induction coil, thereby determining a mutual inductance between the induction coil and the ferromagnetic object. The ferromagnetic element and the non-ferromagnetic element are arranged to be located between the supporting structure and the induction coil and selectively move in the corresponding varying electromagnetic field based on a mutual inductance between the induction coil and the ferromagnetic object.

In order to provide an induction heating cooking device in which a supporting configuration of a heating coil unit is simple and can be easily assembled, and which can accurately and constantly maintain a distance between a top plate and heating coils, opposite side surfaces of a framework laid out below the top plate are configured to have first vertical parts, first horizontal parts, and second vertical parts. A heating coil supporting member that supports the heating coils is disposed to be bridged between the first horizontal parts of the opposite side surfaces of the framework, and the heating coil unit having the heating coil is configured to be securely supported by the first horizontal parts.

According to an embodiment, an electric range includes a core frame. The core frame includes a withdrawal portion on a top surface thereof, formed by removing a portion of a guide rail. The withdrawal portion is configured to guide withdrawal of a working coil to outside of the core frame. A portion of the working coil is disposed on the withdrawal portion. Thus, the number of windings of the working coil around the guide rail of the core frame, a total winding length of the working coil, and a winding range of the working coil is easily adjusted.

An electric range includes a heating part configured to heat an object based on an electromagnetic interaction. The heating part may include a core frame having a plurality of channels disposed radially on a lower surface thereof and a plurality of ferrite cores mounted onto the channels and disposed under the core frame. The core frame include a plurality of air gaps disposed between the plurality of channels. The plurality of air gaps are disposed radially, and the plurality of air gaps connect a center of the core frame and an edge of the core frame.

An induction heater for a cook top comprising: —a first electrically insulating sheet (1); —a second electrically insulating sheet (2); —one or more inductors (5) arranged on a same plane between the first sheet (1) and the second sheet (2), each inductor (5) comprising a single electrically conductive track defining a flat spiral coil provided with a plurality of turns (15); wherein the thickness (t) of each inductor (5) is comprised between 100 and 500 μm; and wherein the ratio between the distance (g) between the consecutive turns (15) of each inductor (5) and the thickness (t) of each inductor (5) is lower than or equal to 1.5.