Abstract: A radiant heater for a glass ceramic top cooking appliance includes a base of thermal and electrical insulating material and at least first and second heating elements arranged such that at least the first heating element provided in a first heating zone is adjacent to at least the second heating element provided in a second heating zone, the first heating element comprising a bright radiating element. A peripheral wall of thermal insulating material surrounds the heating elements and a dividing wall is arranged between the first and second heating elements and extends to a height substantially the same as that of the peripheral wall. A plurality of passages communicates between the first and second heating zones and is disposed in the region of the base of the dividing wall such that, when the bright radiating element is energized, light from the bright radiating element laterally illuminates the second heating zone through the passages.

Abstract: A visual indication is provided in a heater of an electric cooking appliance which incorporates a user-operable multi-position switch for switching the heater from one power output to another. The heater incorporates at least one heating element which is capable of emitting a significant amount of visible radiation, the at least one heating element being de-energized and subsequently re-energized as the heater is switched from one power output to another. Such a heater is of particular value where the heating element is capable of emitting fewer distinct levels of visible radiation than the number of distinct heat settings of the heater selectable from the multi-position switch. The heating element may be de-energized and subsequently re-energized only between adjacent heat settings in which there is no substantial change in the level of visible radiation.

Abstract: In a radiant heater having multiple heating zones there is provided a first heating zone incorporating at least one heating element and a second heating zone incorporating at least first and second heating elements. A thermal cut-out device includes a temperature sensor which passes through at least the first heating zone and which is responsive solely to heat emitted in the first heating zone. A manually operable switch permits switching between first and second heating states. In the first heating state, the at least one heating element in the first heating zone is energised alone, while in the second heating state the at least one heating element in the first heating zone is electrically connected in series with the second heating element of the second heating zone, the at least one heating element and the second heating element being energised in parallel with the first heating element of the second heating zone.

Abstract: A radiant electric heater (10) includes a layer of microporous thermal insulation (16) in a metal dish (12) and a peripheral wall (18) of ceramic fibre. A circular tungsten-halogen heating lamp (22) is supported in the dish above the insulation by its ends and by a protrusion (46) extending from the silica envelope (26) of the lamp. The protrusion extends sideways and is clamped between the insulation and the peripheral wall, and comprises a sealed exhaust tube used to evacuate and back-fill the lamp during its manufacture. Downwardly extending protrusions (120, 718) may be used instead of or in addition to sideways ones. A ridge (48) of the insulating material may also be provided, projecting up to engage with the underside of the lamp. This ridge may cooperate with the protrusion or with a clip (614) extending above the lamp to retain the lamp in position.

Abstract: A radiant electric heater (20) includes a layer of microporous thermal insulation (16) in a metal dish (12) and a peripheral wall (18) of ceramic fibre. A circular tungsten-halogen heating lamp (22) is supported in the dish above the insulation by its ends and by a protrusion (46) extending from the silica envelope (26) of the lamp. The protrusion extends sideways and is clamped between the insulation and the peripheral wall, and comprises a sealed exhaust tube used to evacuate and back-fill the lamp during its manufacture. Downwardly extending protrusions (120, 718) may be used instead of or in addition to sideways ones. A ridge (48) of the insulating material may also be provided, projecting up to engage with the underside of the lamp. This ridge may cooperate with the protrusion or with a clip (614) extending above the lamp to retain the lamp in position.

Abstract: A radiant electric heater arrangement for connection to a power supply system providing first and second different power supply voltages, for example 120 volts and 240 volts, includes a heater having at least first and second heating elements, a rectifier and a switch coupled to the heating elements and to the rectifier. The switch is able to couple the heating elements and the rectifier in a number of different configurations including (a) coupling the heating elements selectively in series and in parallel with one another; (b) coupling the heating elements selectively to the first and second power supply voltages; and (c) coupling the rectifier selectively in series with at least one of the heating elements, thus providing a plurality of user selected power output levels of the heater. Where three or more heating elements are provided, at least one of the heating elements is preferably an infra-red lamp.

Abstract: A radiant electric heater (10) includes a layer of microporous thermal insulation (16) in a metal dish (12) and a peripheral wall (18) of ceramic fibre. A circular tungsten-halogen heating lamp (22) is supported in the dish above the insulation by its ends and by a protrusion (46) extending from the silica envelope (26) of the lamp. The protrusion extends sideways and is clamped between the insulation and the peripheral wall, and comprises a sealed exhaust tube used to evacuate and back-fill the lamp during its manufacture. Downwardly extending protrusions (120, 718) may be used instead of or in addition to sideways ones. A ridge (48) of the insulating material may also be provided, projecting up to engage with the underside of the lamp. This ridge may cooperate with the protrusion or with a clip (614) extending above the lamp to retain the lamp in position.

Abstract: A radiant electric heater has one or more infra-red image (22, 24) having a relatively high temperature coefficient of resistance. To reduce the inrush current when the lamps are first energized, a series resistance coil (54) is provided together with circuitry (64, 68, 70) to bypass the series resistance after a short time interval. Because the energy dissipated in the coil is relatively limited. It can be concealed beneath a peripheral insulating well (18) of the heater.

Abstract: An electric heater assembly for a glass ceramic top cooker includes a plurality of electric heating elements, a thermal cut-out device incorporating a first set of contacts for controlling the supply of electric current to at least one of the heating elements, and a relay associated with the thermal cut-out device and incorporating a second set of contacts for controlling the supply of electric current to at least another of the heating elements. In the event of the thermal cut-out device detecting a first predetermined temperature the first set of contacts moves from a first position to a second position causing the second set of contacts to move from a first position to a second position and in co-operation with the second set of contacts connects the heating elements in a lower power configuration or cuts off the supply of electric power to the heating elements.

Abstract: A radiant electric heater assembly for a glass ceramic top cooker includes four radiant electric heating elements and a thermal cut-out device. Associated with the termal cut-out device is a switching device for connecting the four heating elements in parallel with each other to give a first power level setting and for connecting the heating elements in a lower power configuration in which the elements are connected as two elements connected in series with each other and connected in series with a pair of elements connected in parallel with each other. When the thermal cut-out device detects a first predetermined temperature the heating elements are connected in the lower power configuration until such time as the thermal cut-out device detects a second predetermined temperature, lower than the first predetermined temperature, when the heating elements are reconnected in the configuration of the first power level setting.