Abstract: In the manner of a tubular heater, a temperature sensor comprises a metallic tubular jacket with internal resistance wire coil embedded in insulating material and closing pieces having electrical connection members, so that a very simple, robust and high temperature-resistant temperature sensor with a measuring range up to e.g. approximately 750.degree. C. is obtained. The temperature sensor jacket can be earthed or grounded. For operating the temperature sensor there is appropriately a test current in the mA range in the case of a test voltage in the mV range, whose temperature-dependent changes are processed by means of an electronic amplifier.

Abstract: A temperature switch for limiting the temperature of a glass ceramic plate against the radiation emanating from light and dark radiators has a sensor, which comprises a metallic sensor tube and an inner ceramic rod. Over the sensor is drawn a steatite tube, which on the one hand ensures the electrical insulation between the heaters and the glass ceramic plate and on the other so shields the radiation by reflection, absorption and thermal mass, that the sensor is given a temporary response delay and a greater switching hysteresis.

Abstract: In a cooker with an at least partly translucent cooking or hob surface an operating or hot indication takes place through modular units surrounding the heating unit and which contain individual glow lamps and are spaced from one another around the circumference of the heating unit. They are fixed by holders to the outer rim of the heating unit and are electrically interconnected.Through a different wiring of the individual glow lamps or units it is possible to indicate different states of the heating unit.

Abstract: A temperature switch, used more particular as a temperature limiter for a radiation heating element (11) for heating a glass-ceramic plate (12), has radiation heaters (13, 14). Its rod-shaped temperature sensor (20) has an expansion rod (24) which is disposed in a tube (25) acting as a comparison norm and can be made of a chromium-iron-aluminum alloy and is heat-treated above 1100.degree. C. The tube (25) can be made of a radiation-absorbing material or is coated with such a material, for example, cordierite, non-transmissive glass-ceramics or quartz material. The result of both steps is that the temperature switch has an enhanced switching amplitude and therefore a reduced switching frequency.

Abstract: A radiant heater with a light radiator constructed in the manner of a halogen radiator and a conventional dark radiator radiant heater is arranged in such a way that the dark radiator is arranged in a ring zone surrounding the circular light radiator. The central zone below the light radiator remains unheated. The dark radiator is positioned on an inner shoulder of the rim made from stronger insulating material and which consequently forms a ring with a L-shaped cross-section, which rests on a insulating layer.

Abstract: In a radiant heater (1) an illuminated display (20) is provided for at least part of the heating field (12) and has a low voltage halogen lamp (22) and a glass rod light guide (30) located at a limited distance below the glass ceramic plate (2) and led away from the lamp with at least one light entrance (32). The light guide circularly, spacedly surrounds the outer circumference of the heating field (11) with a display portion and over the length of the latter are distributed light exits (40) in the form of notches (44) or the like. Thus, a corresponding, horizontal, circular display field (45) is formed on the outside (4) of the glass ceramic plate (2). Thus, even when a cooking utensil is in place, the illuminated display (20) can be seen from a considerable distance and the lamp (22), protected against overheating, can be located outside the heated area.

Abstract: A radiant element (11) contains a light radiator, e.g. a substantially circular halogen tubular lamp (15) and a dark radiator (18) in the form of standard open, electric radiant heating coils. For damping or attenuating the high starting or transient current of the light radiator (15), a damping resistor (21) is connected in series therewith, namely during the warming-up phase of the light radiator (15). Following the rise of the resistance of the light radiator due to its heating or after a certain time lapse, a damping switching device (22) disables the series resistor by shorting across it.

Abstract: In the case of an electric heater, particularly a radiant heater for glass ceramic hotplates, there are several spirally nested heating resistors, whereof one heating resistor continuously passes through in the central field in such a way that it forms two nested spirals (10, 17) distributed approximately uniformly over the entire heating field, but which are not directly adjacent to one another and instead between their spiral turns (20, 21) is provided at least one spiral turn of a further, spirally wired heating resistor. This makes it possible in simple manner to make the length of said first-mentioned heating resistor much larger, so that it has a very high rated power, but can still be safely laid or wired in the heating field without any risk of local overheating.

Abstract: In the case of an electric radiant heating element (11) positioned below a glass ceramic plate (12), a rod-like temperature sensor (23) of a thermostat (24) projects over and beyond the heating zone. There are spacers (35) for maintaining a minimum spacing between the insulator (15), which carries the heating resistors (20), and the glass ceramic plate (12).

Abstract: In a radiant heater unit (1) for heating through a hotplate (2), the periphery of the heating field is formed by an initial cooking marginal heating system (9), which is e.g. operated by a short-circuit connection (19), so that it passes much more rapidly from the cold state into the visible glowing state and also in the marginal region use is made of the faster heat transfer there to the bottom (3) of the cooking utensil. The increased radiant power density can also be obtained by other measures, namely by modified insulating conditions in the vicinity of the marginal heating system, by using a PTC resistor in the vicinity of the inner partial power system and similar measures.

Abstract: A radiant heater for cooking appliances with a glass ceramic plate has both bright light-radiating heating elements such as high temperature halogen lamps emitting substantial radiation in the visible range, and also darker glowing radiating elements operable at lower temperatures and radiating emitted light primarily in the infrared region. The bright visible light radiating element and the darker infrared glowing elements are connected in series with one another, whereby the series resistance of the dark or infrared radiator limits initial current loading, and after the radiant elements reach operating temperatures, the infrared element assumes a reduced portion of the total resistance. The visible light and glowing infrared series-connected elements can be interleaved or the visible element can define a boundary for a cooking element.

Abstract: A radiant heater has a shallow shell-like support for carrying heating resistors and a glass ceramic top plate. A connection and hot warning indicating device is arranged in the space between the top plate and the support. The light source is preferably a low voltage tungsten halogen lamp which projects, at most, slightly beyond the front side of the support. Despite a very compact construction, the radiant heater is not subject to dazzle effects even over a large area, and a readily visible indicating illumination is obtained. The light source can be operated at different brightness levels, for example one brightness level indicating the switched-on condition of the heating resistor and the other brightness level indicating the hot-to-touch condition of the top plate, notwithstanding the switched-on or switched-off condition of the heating resistor.

Abstract: A radiant heater for cooking appliances with a glass ceramic plate has both bright light-radiating heating elements such as high temperature halogen lamps emitting substantial radiation in the visible range, and also darker glowing radiating elements operable at lower temperatures and radiating emitted light primarily in the infrared region. The bright visible light radiating element and the darker infrared glowing elements are connected in series with one another, whereby the series resistance of the dark or infrared radiator limits initial current loading, and after the radiant elements reach operating temperatures, the infrared radiant element assumes a reduced portion of the total resistance. The visible light and glowing infrared series-connected elements can be interleaved or the visible element can define a boundary for a cooking element.

Abstract: A temperature sensor for a temperature limiter is made up of an outer tube and a number of inner component rods. The temperature sensor extends transversely over the top side of a moulding of a heating system for a glass-ceramic cooking unit. The heating system comprises a central heating surface and an outer connectable heating surface disposed in a circle therearound. Disposed in the zone of the central heating surface is an inner component rod whose coefficient of expansion is lower than that of the outer tube, while in the zone of the connectable heating surface the component rods have a higher coefficient of expansion than the outer tube.

Abstract: An electrical radiant heating body has two concentric heating zones with independently operable heating resistors. On only switching in the central zone, the associated heating resistor has a very high power which, on connecting in the outer zone, can be reduced by the connection in series of a heating resistor in the outer zone, so that there is a uniform heating surface loading for the total heating surface.The thermometer probe of a thermal cut-out projects over the heating surface and has two contacts operating at different temperatures, one of them being a changeover contact.

Abstract: An electric heating apparatus for heating foods and liquids in a cooking vessel, comprising: a metal upper part, having an upper cooking surface and a lower surface; a metal lower part covering the bottom of the heating apparatus, a sealable space being formed between the upper part and the lower part; and, at least one tubular heating device with a metal covering arranged in the space and having a large flat contact surface for thermally conductively engaging the lower surface of the upper metal part, the space having at least a partial vacuum formed therein, the at least partial vacuum reducing convective heat loss and imparting a concave distortion to the upper metal part which counteracts a convex distortion of the upper metal part due to expansion upon heating, thereby holding the upper metal part substantially flat during heating and maximizing surface contact between the cooking surface and a cooking vessel resting thereon, whereby heat is transferred from the cooking surface to the cooking vessel with

Abstract: A cooker apparatus for heating a cooking pot inductively comprises an induction heating coil and a control device for controlling the heating power. The control device has a temperature-dependent guiding and control means and a sensor unit, adapted to be positioned on the cooking pot and subjected there to the evolution of steam in the cooking pot. The sensor unit is arranged to transmit control signals to the guiding and control means.

Abstract: A power controller for controlling the intermittent supply of current to a load, such as a cooker hotplate, has a pivotally mounted snap switch controlled by a heated bimetal member which is heated in dependence upon the connected power. A compensating bimetal strip, for taking ambient temperature into account, is arranged on the snap switch and parallel thereto. A control cam acts on the free end of the compensating bimetal strip. The latter is shielded from the heat of the heated bimetal member.

Abstract: A power controller for controlling the intermittent supply of current to a load, such as a cooker hotplate, has a pivotally mounted snap switch controlled by a heated bimetal member which is heated in dependence upon the connected power. A compensating bimetal strip, for taking ambient temperature into account, is arranged on the snap switch and parallel thereto. A control cam acts on the free end of the compensating bimetal strip. The latter is shielded from the heat of the heated bimetal member.

Abstract: A power controller for controlling the intermittent supply of current to a load, such as a cooker hotplate, has a pivotally mounted snap switch controlled by a heated bimetal member which is heated in dependence upon the connected power. A compensating bimetal strip, for taking ambient temperature into account, is arranged on the snap switch and parallel thereto. A control cam acts on the free end of the compensating bimetal strip. The latter is shielded from the heat of the heated bimetal member.