Patent ID: 7087866

Claim:
An electric radiant heater adapted to a cooking hob with a top heater plate and radiant heaters, comprising: a substantially flat insulating base parallel to the top plate ( 2 ) and a heating resistor ( 5 ) extended over the surface of the insulating base ( 4 ) according to a given geometric configuration, a peripheral insulating ring wall ( 6 ) in contact with the cooking plate ( 2 ), and an outer cover or metal tray ( 3 ) forming a peripheral outer wall ( 3 , 6 ) of the radiant heater together with said insulating ring, a bimetal type thermal switch ( 7 ) incorporated within the radiant heater, and an electrical power connector ( 8 ) fixed in said peripheral wall ( 3 , 6 ), wherein said peripheral wall ( 3 , 6 ) of the radiant heater ( 1 ) defines a heated plate area ( 2 a ) and below it forms an air cavity ( 13 ) along with the flat insulating base ( 4 ) and said thermal switch ( 7 ) having a compact body ( 7 a ) of heat-resistant insulating, material is retained in a given position (A,B,D,S) inside said air cavity ( 13 ), said compact body ( 7 a ) and terminals ( 11 ) resting on a central surface ( 4 a ) of the insulating base such that said thermal switch ( 7 ) is thermally isolated from said peripheral wall ( 3 , 6 ), and wherein a bimetal element ( 7 c ) is facing towards heat radiation from at least one portion of the heating resistor ( 5 ) for the detection of a temperature value (ST) correlated to an actual temperature (ZT) within a defined warning range (TV) of the plate area ( 2 a ) during both heating up and cooling down processes of said radiant heater, wherein the bimetallic switch ( 7 ), receiving the heat radiation directly from said at least one portion of the heating resistor ( 5 ), has an electrical contact ( 9 ) which is set at an actuation point (SWC, SWO) for the switching of a warning indication of the condition “hotplate”, and wherein said heat radiation is transmitted by way of a receiver base ( 7 b ) in the sensor compact body made of thermal conductor material ( 7 b ), which is positioned opposite and close to said at least one portion of the heating resistor ( 5 ), separated from the heating resistor ( 5 ) by an intermediate space (A) which is determined in order to obtain a suitable actuation point (SWC, SWO) for actuating the electrical contact ( 9 ).