Abstract: A radiant electric heater for use in a smooth top cooker includes a base of electrical and thermal insulating material and two heating elements supported on the base. One of the heating elements is energisable independently of the other element, for example to permit the heater to be adapted to different size cooking utensils. A peripheral wall of thermal insulating material extends laterally around the heating elements and a dividing wall is arranged between the heating elements such that, in use, separate and distinct heating zones are formed on the smooth top of the cooker. The dividing wall is received in the base of electrical and thermal insulating material and is retained in the base by friction. The dividing wall may additionally be constructed and arranged as a barrier effectively only to thermal convection currents generated in the heater.

Abstract: A device for controlling or limiting temperature in an electric cooking appliance includes a switch and a temperature sensor operatively coupled to the switch. The temperature sensor takes the form of a rod arranged substantially coaxially within a tube. The rod is made of a material having a first coefficient of thermal expansion and the tube is made of at least two tube portions, one of the tube portions being made from a material having a second coefficient of thermal expansion lower than the first coefficient of thermal expansion and another of the tube portions being made from a ceramic material having a third coefficient of thermal expansion intermediate the first and second coefficients of thermal expansion. The temperature controlling or limiting device may be incorporated into a radiant electric heater incorporating at least first and second heating elements defining separate heating areas for the cooking appliance.

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 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.