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 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 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: 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: A radiant heating element for heating a glass ceramic plate carries on a circular insulating support heating elements in the form of wire coils fixed thereto, which are arranged in the form of two parallel spiral paths. Two separately switchable heating conductors are successively arranged in one spiral path, while the third heating conductor is positioned alone in the other spiral path. The heating conductors have different power levels and can be switched to different power stages by a seven-timing switch.

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 electrical heating element (18) for heating a plate, e.g. a glass ceramic plate (14) has a multilayer insulating support (12) in whose dish-shaped depression heater coils (18) are arranged in spiral form. The heater coils are located on the insulating support surface (17) and have downwardly directed deformations (19) comprising a turn pressed out in the downwards direction. These deformations (19) are embedded in the surface layer (16) of the insulating support, which is mechanically stronger and more thermally conductive than the underlying insulating layer (15). The deformations are produced in a mould (22, 23) carrying the heater coils in slots (21) and by means of a bladelike punch (24) a turn is pressed into a depression (25). The connection between heater coil (18) and insulating support (12) during the moulding thereof comprises a loose insulating material, the heater coil and deformations being placed in slots (27) of mould part (26).

Abstract: A method for the manufacture of a radiant electrical heater, intended more particularly for heating glass ceramic hotplates, comprises so inserting or pressing helical heating resistors in helical slots in a support, such that the support or the heater coils themselves are deformed and consequently fixed to the support. The coils penetrate the wall or bottom areas of the slot or are otherwise secured by parts of the support by positive engagement. An apparatus for performing the method has a tool with ribs which deforms the support or heater coils for positive engagement.A radiant heater is obtained, whose support has partly overlapping deformations in the slot area of the heater coils.