Induction coil assembly for an induction cooking hob

An induction coil assembly for an induction cooking hob has a coil winding, a lower electrically isolating sheet and optionally a thermally insulating sheet. The induction coil assembly further includes a carrier plate for supporting the lower electrically isolating sheet, the coil winding and the thermally insulating sheet. At least two power cables are provided for each coil winding. The power cables are at least partially arranged at a bottom side of the carrier plate and act as spring elements, so that the induction coil assembly can be pressed or is pressed against a glass ceramic panel of the induction cooking hob.

The present invention relates to an induction coil assembly for an induction cooking hob. Further, the present invention relates to an induction cooking hob comprising at least one induction coil assembly.

An induction cooking hob comprises a number of induction coils arranged within said induction cooking hob. The induction coils should lie against the bottom side of a glass ceramic panel of the induction cooking hob. Typically, the induction coils are supported by a coil carrier of the induction cooking hob. Each induction coil has to be fastened within said induction cooking hob. Usually, the induction coil consists of a lower electrically isolating sheet, a coil winding upon said lower electrically isolating sheet and a thermally insulating sheet upon said coil winding. Additionally, an upper electrically isolating sheet is arranged above the thermally insulating sheet and ferrite elements are arranged beneath the lower electrically isolating sheet. Further, an electric connection between the coil winding and a power supply unit is required. If the induction cooking hob comprises temperature sensors, then an electric connection between said temperature sensors and a control unit is required. Mostly, the installation of the components of the induction cooking hob is very complex.

It is an object of the present invention to provide an induction cooking hob or a part of an induction cooking hob, which allows a suitable arrangement of the components by low complexity.

According to the present invention an induction coil assembly for an induction cooking hob is provided, whereinthe induction coil assembly comprises at least one coil winding, at least one lower electrically isolating sheet and optionally at least one thermally insulating sheet,the coil winding is dedicated to one lower electrically isolating sheet and one thermally insulating sheet,the coil winding is arranged above the dedicated lower electrically isolating sheet,the thermally insulating sheet is arranged above the dedicated coil winding,the induction coil assembly comprises a carrier plate provided for supporting the lower electrically isolating sheet, the coil winding and the thermally insulating sheet,the carrier plate is made of a metal sheet, preferably an aluminium sheet, or of a plastic sheet,for each coil winding the induction coil assembly comprises at least two power cables connected to said dedicated coil winding on the one hand and connectable or connected to a power supply unit of the induction cooking hob on the other hand,the induction coil assembly is installable or installed within the induction cooking hob and between a coil carrier and a glass ceramic panel of said induction cooking hob, andthe power cables are at least partially arranged at a bottom side of the carrier plate and act as spring elements, so that the induction coil assembly can be pressed or is pressed against the glass ceramic panel of the induction cooking hob.

The induction coil assembly forms a modular unit of the induction cooking hob. The complete induction coil assembly is installable or installed inside the induction cooking hob. The carrier plate supports one or more induction coils and forms the base plate of the induction coil assembly. The one or more induction coils are installable into the induction cooking hob by one step. Since the power cables at the bottom side of the carrier plate act as spring elements, the induction cooking hob and the induction coil assembly do not require any special spring element. The power cable includes conductive, shieling and isolating materials, so that the heterogeneous structure of the power cable allows properties like the spring element, in particular in combination with the carrier plate. This reduces the complexity of the induction cooking hob and the induction coil assembly.

Preferably, the induction coil assembly comprises two or more coil windings and dedicated lower electrically isolating sheets and thermally insulating sheets, wherein said coil windings and dedicated sheets, respectively, are arranged in series, and wherein preferably the coil windings and/or the thermally insulating sheets have elliptical, circular, rectangular, triangular and/or square base areas. Alternatively, the coil windings may be arranged as a matrix on the carrier plate. According to one embodiment, the coil windings are arranged in series on the carrier plate, wherein a number of said carrier plates are arranged in parallel, so that the coil windings are arranged as a matrix on the induction cooking hob. In general, the coil windings may have any arbitrary suitable base areas.

Further, the induction coil assembly may comprise at least one temperature sensor, wherein preferably at least one temperature sensor is dedicated for each induction coil.

In particular, the temperature sensor is arranged within a recess formed in the thermally insulating sheet and/or coil winding, wherein preferably said recess is formed in a central portion of the thermally insulating sheet and/or coil winding, respectively.

Moreover, the induction coil assembly comprises at least one sensor cable for each temperature sensor, wherein said sensor cable is connected to the dedicated temperature sensor on the one hand and connectable or connected to a control unit of the induction cooking hob on the other hand.

Furthermore, the carrier plate includes a number of bore holes or cut-outs, wherein at least a part of said bore holes or cut-outs is arranged beneath the temperature sensors, and wherein the size of the bore hole or cut-out beneath the temperature sensor is provided for adjusting an airflow for cooling said temperature sensor, and wherein preferably at least a part of said bore holes or cut-outs is reinforced by a thicker material, a traverse and/or an embossment. Alternatively, the bore holes or cut-outs are formed without any reinforcing elements. By the size of the bore hole or cut-out the airflow for cooling the temperature sensor can be controlled.

Additionally, the induction coil assembly comprises an upper electrically isolating sheet arranged above the one or more thermally insulating sheets. The upper electrically isolating sheet is provided for covering all thermally insulating sheets and the coil winding beneath them.

In particular, the carrier plate includes a number of cable holes, wherein each cable hole is provided for one power cable, and wherein preferably the cable holes are arranged close to the border of the carrier plate.

Further, the carrier plate includes a number of pin holes provided for receiving pins, in particular for fastening the carrier plate on a coil carrier of the induction cooking hob, wherein preferably at least a part of said pin holes is reinforced by a thicker material, a traverse and/or an embossment arranged beside the longitudinal edges of the carrier plate. Alternatively, the pin holes may be formed without any reinforcing elements.

Moreover, the induction coil assembly may comprise a plurality of ferrite elements arranged between the carrier plate and the lower electrically isolating sheet, wherein preferably said ferrite elements are formed as stripes, rectangular sheets or semicircular sheets arranged radially or according to another regular patter beneath each lower electrically isolating sheet.

In this case, the ferrite elements may be glued and/or clipped on the carrier plate, wherein preferably the lower electrically isolating sheet is glued on said dedicated ferrite elements.

Preferably, the coil winding is glued on the dedicated lower electrically isolating sheet.

In contrast, the thermally insulating sheet is disposed on the dedicated coil winding, wherein preferably the upper electrically isolating sheet is disposed on the one or more thermally insulating sheets.

In particular, the carrier plate includes at least one bend edge formed at one or more sides of said carrier plate, wherein preferably the bend edge is formed at one or two longitudinal sides of the carrier plate. The bend edge allows a stabilization of the carrier plate.

At last, the present invention relates to an induction cooking hob comprising at least one induction coil assembly mentioned above, wherein the at least one induction coil assembly is arranged within the induction cooking hob and beneath a glass ceramic panel of said induction cooking hob.

Novel and inventive features of the present invention are set forth in the appended claims.

FIG. 1illustrates a schematic exploded perspective top view of an induction coil assembly10according to a preferred embodiment of the present invention. The induction coil assembly10forms a modular unit of an induction cooking hob. The induction coil assembly10as a whole is installable or installed inside the induction cooking hob. Preferably, the induction coil assembly10is arranged beneath a glass ceramic panel and above a coil carrier28of said induction cooking hob. One or more induction coil assemblies10may be installable or installed in one induction cooking hob.

The induction coil assembly10comprises a carrier plate12, a number of lower electrically isolating sheets14, a number of coil windings15, a number of thermally insulating sheets16and an upper electrically isolating sheet22. Each coil winding15is arranged upon a dedicated lower electrically isolating sheet14. A thermally insulating sheet16is disposed upon each coil winding15. The upper electrically isolating sheet22is disposed above the thermally insulating sheets16. The carrier plate12is provided for supporting the coil windings15and the corresponding sheets14,16and22.

Further, the induction coil assembly10comprises ferrite elements18and temperature sensors20. In this example, the ferrite elements18are formed as stripes and star-shaped beneath each lower electrically isolating sheet14. The ferrite elements18are glued or clipped on the carrier plate12. The lower electrically isolating sheets14are arranged above the ferrite elements18. In this example, the ferrite elements18formed as stripes are arranged radially beneath each carrier plate12. The temperature sensor20is arranged within a recess24formed in the dedicated lower electrically isolating sheet14, coil winding15and thermally insulating sheet16in each case.

According to the preferred embodiment the one upper electrically isolating sheet22is formed as a single-piece part and covers all thermally insulating sheets16. Alternatively, the induction coil assembly10may comprise two or more upper electrically isolating sheets22, wherein each upper electrically isolating sheet22covers one or more neighboured thermally insulating sheets16.

For example, the lower electrically isolating sheets14and the upper electrically isolating sheet22are made of mica and/or glimmer. Further, the thermally insulating sheets16may be made of melange. Preferably, the coil windings15are made of copper.

In this example, the carrier plate12supports four lower electrically isolating sheets14, four coil windings15, four thermally insulating sheets16and an upper electrically isolating sheet22, wherein the lower electrically isolating sheets14, the coil windings15and the thermally insulating sheets16, respectively, are arranged in series. Alternatively, the coil windings16and the corresponding sheets14and16may be arranged as a matrix on the carrier plate12. In particular, the coil windings16and the corresponding sheets14and16are arranged in series on the carrier plate12, wherein a number of said carrier plates12are arranged in parallel, so that the coil windings16and the corresponding sheets14and16are arranged as a matrix on the induction cooking hob.

In this embodiment, the coil windings16and the thermally insulating sheets16have elliptical base areas. In general, the coil windings16may have arbitrary suitable base areas, such as circular, rectangular and/or square base areas.

The carrier plate12is made of a metal sheet or plastic sheet. Preferably, the carrier plate12is made of an aluminium sheet. According to the preferred embodiment, the carrier plate12includes one or more bend edges26. In this example, the carrier plate12includes two bend edges26extending along the longitudinal edges of said carrier plate12. The bend edges26allow a stabilization of the carrier plate12.

FIG. 2illustrates a sectional perspective top view of the induction coil assembly10according to the preferred embodiment of the present invention. InFIG. 2the induction coil assembly10is arranged upon a coil carrier28of the induction cooking hob. The induction coil assembly10comprises four lower electrically isolating sheets14, four coil windings16, four thermally insulating sheets16and the upper electrically isolating sheet22, wherein two lower electrically isolating sheets14, two coil windings16and two thermally insulating sheets16are shown inFIG. 2.

In this example, the carrier plate12includes two bend edges26extending along the longitudinal edges of said carrier plate12. The bend edges26allow a stabilization of the carrier plate12.

The ferrite elements18are glued or clipped on the carrier plate12. In this example, the ferrite elements18are formed as stripes and star-shaped beneath each lower electrically isolating sheet14. Alternatively, the ferrite elements18may be arranged in any other regular patterns. The lower electrically isolating sheets14are arranged on the dedicated ferrite elements18. Preferably, the lower electrically isolating sheets14are glued on the ferrite elements18. In turn, the coil windings15are glued on the dedicated lower electrically isolating sheets14. The thermally insulating sheets16are disposed on the dedicated coil windings15. The upper electrically isolating sheet22is disposed upon the thermally insulating sheets16.

Each temperature sensor20is arranged within the recess24formed in the dedicated thermally insulating sheet16and coil winding15in each case. Each coil winding15is connected to a power supply unit and/or a drive unit via two power cables30. For example, the drive unit is interconnected between the power supply unit and the coils winding15. The temperature sensor20is connected to a control unit via a sensor cable32. The sensor cable32is fixed by a fixation element34at one of the power cables30of the dedicated induction coil16. Preferably, the fixation of the sensor cable32is close to a plug of said sensor cable32.

FIG. 3illustrates a perspective bottom view of the induction coil assembly10according to the preferred embodiment of the present invention. The bottom side of the induction coil assembly10is formed by the carrier plate12.

The carrier plate12includes a number of bore holes36or cut-outs, a number of cable holes37and a number of pin holes38. The bore holes36or cut-outs are arranged along a central longitudinal axis of the carrier plate12. The bore holes36or cut-outs may have the same size or different sizes. The cable holes37are arranged beside one longitudinal edge of the carrier plate12. The pin holes38are arranged beside the longitudinal edges of the carrier plate12.

The bore holes36or cut-outs are arranged beneath the dedicated temperature sensors20. By the size of the bore hole36or cut-out beneath the temperature sensor20the airflow for cooling said temperature sensor20may be adjusted. Further, the bore holes36or cut-outs may be reinforced by a thicker material around said bore holes36or cut-out and/or by a traverse and/or an embossment formed in the environment of said bore holes36or cut-outs.

The power cables30pass through the cable holes37. Preferably, for each power cable30of each coil winding15a dedicated cable hole37is provided. The power cables30for the different coil windings16may have different lengths, so that the cables cannot be plugged to a wrong connector of the power supply unit.

The power cables30between the carrier plate12and the coil carrier28extend horizontally and act as spring elements, so that the induction coil assembly10can be pressed or is pressed against the glass ceramic panel of the cooking hob. The power cable30includes conductive, shieling and isolating materials, so that the heterogeneous structure of said power cable30allows properties like the spring element, in particular in combination with the carrier plate12. The induction coil assembly10does not require any special spring elements.

The pin holes38are provided for receiving the pins fastening the coil carriers14at the carrier plate12. For every pin, a hole or press cut is formed in the coil carrier14. In those portions of the coil carrier14, which are penetrated by the pin, the material is thicker and/or a traverse and/or an embossment are formed.

Although an illustrative embodiment of the present invention has been described herein with reference to the accompanying drawings, it is to be understood that the present invention is not limited to that precise embodiment, and that various other changes and modifications may be affected therein by one skilled in the art without departing from the scope or spirit of the invention. All such changes and modifications are intended to be included within the scope of the invention as defined by the appended claims.

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