Ceramic top range surface temperature cut-off thermostatic device

Claim 2

A radiant cooking assembly comprising an upper utensil supporting cover plate of infrared transmissive glass-ceramic material, a refractory heater block disposed below said cover plate by support housing means, said heater block having a raised peripheral face defining a central recessed area in spaced relation with the undersurface of said cover plate, means for biasing said heater block peripheral face into pressure contact with said cover plate undersurface, an infrared radiating resistance element located on said central recessed area in spaced relation below said cover plate defining a cover plate utensil heating area coextensive with said recessed area, a control circuit for energizing said resistance element, a temperature limiting device for maintaining the temperature of said cover plate below a preselected maximum temperature, said temperature limiting device comprising temperature sensitive bracket means for supporting a differential-expansion type thermostat in heat transfer relation therewith exterior of said support housing means and spaced below said cover plate, said bracket means having a heat sensing flange sandwiched between said heater block peripheral face and said cover plate undersurface so as to be pressure biased in conductive heat transfer with said cover plate, said heat sensing flange located outside the confines of said heating area so as to be shielded from radiant heat from said resistance element by said heater block to thereby conductively sense the temperature of said cover plate contiguous with said heating area, said thermostat having switch means in said control circuit whereby said thermostat under the influence of said bracket means temperature functions to heat and cool proportionally to the heating and cooling of said heating area such that said resistance element is open circuited by said switch means whenever the temperature of said heating area exceeds said preselected maximum temperature.

Claim 3

A temperature limiting device in combination with a radiant heating unit, said combination comprising, an upper utensil supporting cover plate of infrared transmissive glass-ceramic material, a heater block composed of low density fibrous refractory material disposed below said plate by a metallic support housing, said heater block having a raised peripheral face defining a central recessed area in spaced relation with the undersurface of said cover plate, means for biasing the peripheral face of said heater block into pressure engagement with said cover plate undersurface, a convolute shaped infrared radiating resistance element located on said central recessed area defining a cover plate utensil heating area cOextensive with said recessed area, a control circuit for energizing said resistance element, an energy varying switch in said control circuit pulsatingly varying the power input to said resistance element, a temperature sensitive U-shaped bracket for supporting a differential-expansion type thermostat exterior of said support housing and spaced below said cover plate, said U-shaped bracket having upper and lower flanges integral therewith, said upper heat flange sandwiched between said heater block peripheral face of said cover plate undersurface so as to be pressure biased in conductive heat transfer with said cover plate, said heat sensing flange located outside the confines of said heating area so as to be shielded from radiant heat from said resistance element by said heater block to thereby conductively sense the temperature of said cover plate contiguous with said heating area, said lower flange being adjustably secured to said support housing whereby said biasing means being operative to embed said temperature sensitive upper flange in said heater block peripheral face such that the upper surface of said flange is substantially planar with said heater block peripheral face, said U-shaped bracket having a tubular channel integrally formed in the base portion of said U-shaped bracket, said thermostat having switch means in said control circuit and an elongated heat-sensitive sleeve telescopically received in and surrounded by said tubular channel, said sleeve and said tubular channel being positioned in intimate heat transfer relationship throughout substantially their entire peripheral surfaces, said U-shaped bracket operative to heat and cool said thermostatic sleeve proportionally to the heating and cooling of said cover plate heating area such that said resistance element is open circuited by said switch means whenever the temperature of said heating area exceeds said preselected maximum temperature.

Claim 4

A temperature limiting device in combination with a radiant heating unit, said combination comprising, an upper utensil supporting cover plate of infrared transmissive glass-ceramic material, a heater block composed of low density fibrous refractory material disposed below said plate by a metallic support housing, said heater block having a raised peripheral face defining a central recessed area in spaced relation with the undersurface of said cover plate, means for biasing the peripheral face of said heater block into pressure engagement with said cover plate undersurface, a convolute shaped infrared radiating resistance element located on said central recessed area defining a cover plate utensil heating area cOextensive with said recessed area, a control circuit for energizing said resistance element, an energy varying switch in said control circuit pulsatingly varying the power input to said resistance element, a temperature sensitive U-shaped bracket for supporting a differential-expansion type thermostat exterior of said support housing and spaced below said cover plate, said U-shaped bracket having upper and lower flanges integral therewith, said upper heat flange sandwiched between said heater block peripheral face of said cover plate undersurface so as to be pressure biased in conductive heat transfer with said cover plate, said heat sensing flange located outside the confines of said heating area so as to be shielded from radiant heat from said resistance element by said heater block to thereby conductively sense the temperature of said cover plate contiguous with said heating area, said lower flange being adjustably secured to said support housing whereby said biasing means being operative to embed said temperature sensitive upper flange in said heater block peripheral face such that the upper surface of said flange is substantially planar with said heater block peripheral face, said U-shaped bracket having a tubular channel integrally formed in the base portion of said U-shaped bracket, said thermostat having switch means in said control circuit and an elongated heat-sensitive sleeve telescopically received in and surrounded by said tubular channel, said sleeve and said tubular channel being positioned in intimate heat transfer relationship throughout substantially their entire peripheral surfaces, said U-shaped bracket operative to heat and cool said thermostatic sleeve proportionally to the heating and cooling of said cover plate heating area such that said resistance element is open circuited by said switch means whenever the temperature of said heating area exceeds said preselected maximum temperature.

Claim 5

A temperature limiting device in combination with an infrared radiant cooking assembly for mounting in a range top or the like having an opening therein, said assembly comprising a frangible cover plate of infrared transmissive recrystallized glass-ceramic material including an upper utensil supporting surface, said cover plate positioned in said opening whereby a continuous gap is defined between the edges of said cover plate and said opening, a lower support housing positioned below said cover plate having a bottom wall, end walls, and sidewalls defining a boxlike receptacle, at least one radiant heating unit supported in said housing, said heating unit including a fibrous-ceramic heater support block having a substantially planar raised peripheral face defining a central recessed area, said recessed area supporting an infrared emissive uninsulated electrical resistance element thereon in spaced relation below the cover plate heating area defined by said recessed area, continuous pressure clamping means positioned in said gap for retaining said cover plate and said housing in said range opening, a control circuit for energizing said resistance element across first and second power lines, a variable energy output switch in said control circuit pulsatingly varying the power input to said resistance element, a thermostatic control device including a switch in said circuit arranged to limit the temperature of said cover plate to a maximum temperature of the order of 1,300* F., said control device including a temperature responsive U-shaped support bracket fixed on the exterior of said housing having an upper cover plate temperature sensing flange integral therewith, said temperature sensitive flange located on the peripheral face of said heater block whereby said flange is held in compressed thermal conductive contact with the undersurface of said cover plate by said continuous pressure clamping means, said heat sensing flange located outside the confines of said heating area so as to be shielded from radiant heat from said resistance elemeNt by said heater block, said U-shaped bracket having a tubular channel integrally formed in the base portion thereof, said thermostatic control device having an elongated thermostatic sleeve telescopically received in and surrounded by said tubular channel, said sleeve and said tubular channel being positioned in intimate heat transfer relationship throughout substantially their entire peripheral surfaces, said support bracket being composed of metal having good heat conducting properties and serving to thermally isolate said thermostatic sleeve from direct radiation from said resistance element, said thermostatic control device calibrated to open its line circuit switch at a cover plate temperature contiguous with said heating area of the order of 430* F. whereby said sleeve functions to heat and cool proportionally to the heating and cooling of said cover plate such that upon said cover plate heating area attaining temperature exceeding approximately 1,300* F. said thermostatic switch will open to remove said heating element from said power source.

Claim 6

A temperature limiting device in combination with an infrared radiant cooking assembly for mounting in a range top or the like having an opening therein, said assembly comprising a frangible cover plate of infrared transmissive recrystallized glass-ceramic material including an upper utensil supporting surface, said cover plate positioned in said opening whereby a continuous gap is defined between the edges of said cover plate and said opening, a lower support housing positioned below said cover plate having a bottom wall, end walls, and sidewalls defining a boxlike receptacle, at least one radiant heating unit supported in said housing, said heating unit including a fibrous-ceramic heater support block having a substantially planar raised peripheral face defining a central recessed area, said recessed area supporting an infrared emissive uninsulated electrical resistance element thereon in spaced relation below the cover plate heating area defined by said recessed area, continuous pressure clamping means positioned in said gap for retaining said cover plate and said housing in said range opening, a control circuit for energizing said resistance element across first and second power lines, a variable energy output switch in said control circuit pulsatingly varying the power input to said resistance element, a thermostatic control device including a switch in said circuit arranged to limit the temperature of said cover plate to a maximum temperature of the order of 1,300* F., said control device including a temperature responsive U-shaped support bracket fixed on the exterior of said housing having an upper cover plate temperature sensing flange integral therewith, said temperature sensitive flange located on the peripheral face of said heater block whereby said flange is held in compressed thermal conductive contact with the undersurface of said cover plate by said continuous pressure clamping means, said heat sensing flange located outside the confines of said heating area so as to be shielded from radiant heat from said resistance elemeNt by said heater block, said U-shaped bracket having a tubular channel integrally formed in the base portion thereof, said thermostatic control device having an elongated thermostatic sleeve telescopically received in and surrounded by said tubular channel, said sleeve and said tubular channel being positioned in intimate heat transfer relationship throughout substantially their entire peripheral surfaces, said support bracket being composed of metal having good heat conducting properties and serving to thermally isolate said thermostatic sleeve from direct radiation from said resistance element, said thermostatic control device calibrated to open its line circuit switch at a cover plate temperature contiguous with said heating area of the order of 430* F. whereby said sleeve functions to heat and cool proportionally to the heating and cooling of said cover plate such that upon said cover plate heating area attaining temperature exceeding approximately 1,300* F. said thermostatic switch will open to remove said heating element from said power source.

Claim 7

A temperature limiting device in combination with each heating unit of an infrared radiant cooking assembly for mounting in a range top or the like having an opening therein, said assembly comprising a translucent cover plate of infrared transmissive glass-ceramic material including an upper utensil supporting surface, said cover plate positioned in said opening whereby a continuous gap is defined between the longitudinal and transverse edges of said cover plate and said opening, a lower housing positioned below said cover plate having a bottom wall, end walls and sidewalls defining a boxlike receptacle, said housing having one sidewall parallel with and adjacent to a transverse edge of said cover plate, a pair of radiant heating units having dissimilar wattage outputs supported in said housing, each said heating unit including a fibrous-ceramic heater block having a substantially planar raised peripheral face positioned above the side and end walls of said housing defining a central substantially disk-shaped recessed area, said heating unit recessed areas being of dissimilar size whereby their outer edges are aligned on a tangent substantially parallel to said one housing sidewall, said recessed areas each supporting an infrared emissive uninsulated electrical resistance element thereon in spaced relation below the undersurface of said cover plate, continuous pressure clamping means positioned in said gap for retaining said cover plate and said housing in said range opening, a control circuit for energizing said resistance element across first and second power lines, an infinite heat type switch in said control circuit associated with each said heating unit pulsatingly varying the power input to their respective resistance elements, a pair of identical thermostatic control devices each including a switch in said circuit associated with each of said heating units respectively to limit the temperature of said cover plate heating areas to a maximum temperature of the order of 1,300* F., each said control device including a temperature responsive U-shaped support bracket having an upper heat sensing flange and a lower securing flange integral therewith, each of said upper heat sensing flanges located on the upper peripheral face of each said heater block whereby said heat sensing flange is embedded in the peripheral face thereof such that its upwardly facing surface is maintained in pressure thermal conductive contact with the marginal undersurface portions of said cover plate by said continuous pressure clamping means, said upper flanges being substantially similarly positioned between said cover plate outer transverse edge and its associated heater block recessed area, each said bracket lower flange being fixed to said one housing sidewall, each said U-shaped bracket having a tubular channel integrally formed in the base portion thereof, said thermostatic control device having aN elongated thermostatic sleeve telescopically received in and surrounded by said tubular channel, said sleeve and said tubular channel being positioned in intimate heat transfer relationship throughout substantially their entire peripheral surfaces, said support bracket being composed of metal having good heat conducting properties and serving to thermally isolate said sleeve from direct exposure to temperatures within said heater block recessed areas, each said thermostatic control device calibrated to open its line circuit switch at a cover plate temperature intermediate its associated recessed area and the adjacent edge of said cover plate of the order of 430* F. whereby said sleeve functions to heat and cool proportionately to the heating and cooling of said marginal undersurface area of said cover plate heating area such that upon said cover plate heating area attaining a temperature in excess of the order of 1,300* F. said thermostatic switch will open to remove its associated heating unit from said power lines.

Claim 8

A temperature limiting device in combination with each heating unit of an infrared radiant cooking assembly for mounting in a range top or the like having an opening therein, said assembly comprising a translucent cover plate of infrared transmissive glass-ceramic material including an upper utensil supporting surface, said cover plate positioned in said opening whereby a continuous gap is defined between the longitudinal and transverse edges of said cover plate and said opening, a lower housing positioned below said cover plate having a bottom wall, end walls and sidewalls defining a boxlike receptacle, said housing having one sidewall parallel with and adjacent to a transverse edge of said cover plate, a pair of radiant heating units having dissimilar wattage outputs supported in said housing, each said heating unit including a fibrous-ceramic heater block having a substantially planar raised peripheral face positioned above the side and end walls of said housing defining a central substantially disk-shaped recessed area, said heating unit recessed areas being of dissimilar size whereby their outer edges are aligned on a tangent substantially parallel to said one housing sidewall, said recessed areas each supporting an infrared emissive uninsulated electrical resistance element thereon in spaced relation below the undersurface of said cover plate, continuous pressure clamping means positioned in said gap for retaining said cover plate and said housing in said range opening, a control circuit for energizing said resistance element across first and second power lines, an infinite heat type switch in said control circuit associated with each said heating unit pulsatingly varying the power input to their respective resistance elements, a pair of identical thermostatic control devices each including a switch in said circuit associated with each of said heating units respectively to limit the temperature of said cover plate heating areas to a maximum temperature of the order of 1,300* F., each said control device including a temperature responsive U-shaped support bracket having an upper heat sensing flange and a lower securing flange integral therewith, each of said upper heat sensing flanges located on the upper peripheral face of each said heater block whereby said heat sensing flange is embedded in the peripheral face thereof such that its upwardly facing surface is maintained in pressure thermal conductive contact with the marginal undersurface portions of said cover plate by said continuous pressure clamping means, said upper flanges being substantially similarly positioned between said cover plate outer transverse edge and its associated heater block recessed area, each said bracket lower flange being fixed to said one housing sidewall, each said U-shaped bracket having a tubular channel integrally formed in the base portion thereof, said thermostatic control device having aN elongated thermostatic sleeve telescopically received in and surrounded by said tubular channel, said sleeve and said tubular channel being positioned in intimate heat transfer relationship throughout substantially their entire peripheral surfaces, said support bracket being composed of metal having good heat conducting properties and serving to thermally isolate said sleeve from direct exposure to temperatures within said heater block recessed areas, each said thermostatic control device calibrated to open its line circuit switch at a cover plate temperature intermediate its associated recessed area and the adjacent edge of said cover plate of the order of 430* F. whereby said sleeve functions to heat and cool proportionately to the heating and cooling of said marginal undersurface area of said cover plate heating area such that upon said cover plate heating area attaining a temperature in excess of the order of 1,300* F. said thermostatic switch will open to remove its associated heating unit from said power lines.