Ceramic hotplate consisting of a glass ceramic plate

• US 20040074893A1
• Filed: 09/08/2003
• Published: 04/22/2004
• Est. Priority Date: 03/06/2001
• Status: Abandoned Application

• Current Assignee: Schott AG (Carl-Zeiss-Stiftung)
• Original Assignee: Schott AG (Carl-Zeiss-Stiftung)
• Inventors: Köbrich, Holger, Wermbter, Karsten
• Application Number:
  US10/471,130
• Publication Number:
  US 20040074893A1
• Time in Patent Office: Days
• US Class Current: 219/465.1
• CPC Class Codes: H05B 3/68 Heating arrangements specially adapted for cooking plates or analogous hot-plates
• CPC Class Codes: H05B 3/72 Plates of sheet metal
• CPC Class Codes: H05B 3/74 Non-metallic plates , e.g. vitroceramic, ceramic or glassceramic hobs, also including power or control circuits
• CPC Class Codes: H05B 3/746 Protection, e.g. overheat cutoff, hot plate indicator
• CPC Class Codes: H05B 3/748 Resistive heating elements, i.e. heating elements exposed to the air, e.g. coil wire heater H05B3/742 takes precedence

Abstract

The invention relates to a ceramic hot-plate with a glass ceramic plate which includes heating elements, which are separated by an insulating layer, for direct heating on the lower side thereof. The cooking area is sub-divided into at least one inner and one outer area which include individual heating elements for each partial area. Said heating elements can be switched or adjusted with regard to the output thereof by means of a control device according to temperature values detected by temperature sensors associated with the partial areas. Concentrically arranged conductor strips enable the hot-plate to be constructed easily, the design thereof ensuring that the surface thereof is used in an optimum manner and providing a high degree of heating efficiency by virtue of the homogeneous manner in which the partial areas are heated.

Claims

1. A ceramic cooktop with a glass-ceramic plate, which has heating elements separated by an insulating layer on its underside for direct heating, wherein the cooking zone is divided into at least one inner and one outer partial zone, containing individual heating elements in the partial zones, which can be switched or whose output can be regulated by a control device as a function of the temperature values detected by temperature sensor assigned to the partial zone sensors, characterized in that

the inner partial zone (Wi) and the outer partial zones (Wa) are formed by strip conductors (15), which are arranged concentrically with each other in a circular shape and leave free only one connecting sector (16) extending into the center of the cooking zone,

in the connecting sector (16) the strip conductors (15) are switched in series by means of connecting elements (17),

the start (A) of the innermost strip conductor (15) and the end (E) of the outermost strip conductor (15), as well as a connecting element (17) providing the division of the individual partial zone heating elements (H1, H2), can be controlled by means of connectors (a1, a2 and ao0),

the insulating layer (12) is arranged at least underneath the strip conductors (15), and

a temperature sensor (S0) is assigned to the inner partial zone (Wi), and several temperature sensors (S1, S2, S3, S4) are assigned distributed over the circumference of the outer partial zone (Wa).

3. The ceramic cooktop in accordance with claim 1 or 2, characterized in that

the connectors (a0, a1, a2) in the connecting sector (16) extend past the outer partial zone (Wa).

4. The ceramic cooktop in accordance with one of claims 1 to 3, characterized in that

the temperature sensor (S0) in the center of the inner partial zone (Wi) is embodied as a rod sensor or point sensor and its connector is extended past the cooking zone via the connecting sector (16).

5. The ceramic cooktop in accordance with claim 1, characterized in that

the strip conductors (15) consist of NiCr, NiAl alloys or cermets and are applied by a thermal injection process.

7. The ceramic cooktop in accordance with one of claims 1 to 6, characterized in that

the strip conductors (15) or the surface heating elements (15.1, 15.2) consist of silver-containing webs or layers, which have been applied to the underside of the glass-ceramic plate (10) by means of screen printing, or consist of carbon pastes.

8. The ceramic cooktop in accordance with one of claims 1 to 7, characterized in that

the temperature sensors (S0, S1, S2, S3, S4) have been directly applied to the underside of the glass-ceramic plate (10) outside of the strip conductors (15) or the surface heating elements (15.1, 15.2).

9. The ceramic cooktop in accordance with one of claims 1 to 7, characterized in that

the temperature sensors (S0, S1, S2, S3, S4) are arranged outside of the strip conductors (15) or the surface heating elements ( 15.1, 15.2), wherein these areas of the glass-ceramic plate (10) are covered with thin insulating layers.

10. The ceramic cooktop in accordance with one of claims 1 to 7, characterized in that

the temperature sensors (S0, S1, S2, S3, S4) are housed in protective foils and have been attached directly to the lower conductors (15) or the surface heating elements (15.1, 15.2).

2. A ceramic cooktop with a glass-ceramic plate, which has heating elements separated by an insulating layer on its underside for direct heating, wherein the cooking zone is divided into at least one inner and one outer partial zone, containing individual heating elements in the partial zones, which can be switched or whose output can be regulated by a control device as a function of the temperature values detected by temperature sensor assigned to the partial zone sensors, characterized in that

the inner partial zone (Wi) and the outer partial zones (Wa) are formed by two surface heating elements (15.1, 15.2), which are arranged concentrically with each other in a circular shape and leave free only one connecting sector (16) extending into the center of the cooking zone,

in the connecting sector (16) the two ends of the surface heating elements (15.1, 15.2) are connected together, and the starts of the two surface heating elements (15.1, 15.2) are individually connected by means of connecting elements (a0, a1, a2),

the insulating layer (12) is arranged at least under the surface heating elements (15.1, 15.2), and

one temperature sensor (S0) is assigned to the inner partial zone (Wi), and several temperature sensors (S1, S2, S3, S4) are assigned, distributed over the circumference, to the outer partial zone (Wa).

6. The ceramic cooktop in accordance with claim 2, characterized in that

heating foils, NiCr, NiAl or cermet-containing layers are embodied as surface heating elements (15.1, 15.2) and are applied to partial insulating layers of identical surface.