Patent ID: 6104008
Filing Date: 2000-08-15
Classification: D06F

Abstract:
A stove heater for heating a portion of a stove top comprisinga resistive heating element,a heater support supporting said resistance heating element, anda temperature sensing switching device,said resistance heating element and said switching device being connected in a series circuit to a source of electrical power,said switching device comprisinga base,two terminals supported on said base connecting the switching device into said series circuit,a contactor movable to a first position in which it connects said terminals and to a second position in which it disconnects said terminals,an actuation mechanism controlling the position of said contactor comprising a spring, a pole piece and a permanent magnet,said spring being positioned and arranged so as to provide a spring force urging said contactor toward said second position,said pole piece being supported on said base and positioned and arranged so as to have radiative coupling to said resistance heating element and receive thermal radiation therefrom, and to be thermally coupled to a heat sink, the radiative coupling to the heating element and the coupling to the heat sink being such that the pole piece assumes a temperature substantially below that of the heating element,said permanent magnet being movable towards or away from said pole piece, and being arranged so that said pole piece is within its magnetic field and positioned and arranged so that when it moves toward said pole piece it urges said contactor toward said first position,said pole piece being made of material which has a curie temperature and is ferromagnetic when at a temperature below said curie temperature and not ferromagnetic when at a temperature above said curie temperature, said pole piece when below said curie temperature attracting said magnet with a force overcoming said spring force and moving said contactor to said first position, and when above said curie temperature attracting said magnet with a force less than said spring force,the curie temperature of said pole piece material and the radiative coupling of said pole piece to said resistance heating element being such that the temperature of said heating element is limited.