Heat warning safety device for smooth cooktop stoves

Abstract

Thermochromic compositions designed to turn red or orange and remain red or orange at or above a specified temperature, such as 115 degrees Fahrenheit, are shaped in the outline of the word “HOT” or in an outline of a ring interrupted by the word “HOT” and are embedded on the top surface of the heating element of smooth cooktop stoves or in certain embodiments on the window surface of wall ovens and toaster ovens so that they glow red or orange and instantly alert anyone that the heat element of the stove or the window is too hot to touch. For use on smooth cooktop stoves, including warming trays, the thermochromic display is embedded in a top surface of the smooth area of glass or metal that forms the heating element of the stove. For wall ovens and toaster ovens, the liquid crystals are embedded in the vertical window surface.

What is claimed is:  
     
         1 . An improved plurality of heating elements of a smooth cooktop stove having a top surface that is smooth, each heating element comprising: 
 a smooth area of glass on a smooth top surface of the stove that is subjected to a strong light source underneath said smooth area of glass, said light source generating heat in said smooth area of glass when said smooth area of glass absorbs light from the light source, and a thermochromic composition embedded in a top surface of the smooth area of glass in an outline of a heat warning symbol, said thermochromic composition designed to undergo and maintain a readily perceptible color change whenever the temperature of the smooth area of glass exceeds a specified temperature,    the smooth area of glass in each heating element forming a portion of the smooth top surface of the stove.    
     
     
         2 . The improved plurality of heating elements of  claim 1 , wherein the heat warning symbol is the letters “HOT”.  
     
     
         3 . The device of  claim 2 , wherein the thermochromic composition is designed to turn red and remain red whenever the temperature of the smooth area of glass exceeds 115 degrees Fahrenheit.  
     
     
         4 . The improved plurality of heating elements of  claim 1 , wherein heat warning symbol is a ring surrounding said heating element, which ring contains in an interrupted portion thereof an outline of the letters “HOT”.  
     
     
         5 . The improved plurality of heating elements of  claim 4 , wherein the thermochromic composition is designed to turn red and remain red whenever the temperature of the smooth area of glass exceeds 115 degrees Fahrenheit.  
     
     
         6 . An improved plurality of heating elements of a smooth cooktop stove having a top surface that is smooth, comprising: 
 a smooth area of glass on a smooth top surface of the stove that absorbs heat from an electric heat source directly underneath said smooth area of glass and a thermochromic composition embedded in a top surface of the smooth area of glass in an outline of the letters “HOT” or in an outline of a ring surrounding said heating element, which ring may contain in an interrupted portion thereof an outline of the letters “HOT”, said thermochromic composition designed to undergo and maintain a readily perceptible color change whenever the temperature of the smooth area of glass exceeds a specified temperature,    the smooth area of glass in each heating element forming a portion of the smooth top surface of the stove.    
     
     
         7 . The improved plurality of heating elements of  claim 6 , wherein the heat warning symbol is the letters “HOT”.  
     
     
         8 . The device of  claim 7 , wherein the thermochromic composition is designed to turn red and remain red whenever the temperature of the smooth area of glass exceeds 115 degrees Fahrenheit.  
     
     
         9 . The improved plurality of heating elements of  claim 6 , wherein heat warning symbol is a ring surrounding said heating element, which ring contains in an interrupted portion thereof an outline of the letters “HOT”.  
     
     
         10 . The improved plurality of heating elements of  claim 9 , wherein the thermochromic composition is designed to turn red and remain red whenever the temperature of the smooth area of glass exceeds 115 degrees Fahrenheit.  
     
     
         11 . A device for warning individuals of the hot surface of a smooth cooktop stove, which stove has a top surface that is smooth and having a plurality of heating elements, which heating elements are of the type wherein a smooth area of glass or metal is subjected to a heat source from underneath said area, comprising: 
 thermochromic composition embedded in a top surface of a smooth area of glass in an outline of a heat warning symbol, said thermochromic composition designed to undergo and maintain a readily perceptible color change whenever the temperature of the smooth area of glass exceeds a specified temperature,    the smooth area of glass in each heating element forming a portion of the smooth top surface of the stove.    
     
     
         12 . The device of  claim 11 , wherein the heat warning symbol is the letters “HOT”.  
     
     
         13 . The device of  claim 12 , wherein the thermochromic composition is designed to turn red and remain red whenever the temperature of the smooth area of glass exceeds 115 degrees Fahrenheit.  
     
     
         14 . The device of  claim 11 , wherein heat warning symbol is a ring surrounding said heating element, which ring contains in an interrupted portion thereof an outline of the letters “HOT”.  
     
     
         15 . The device  claim 14 , wherein the thermochromic composition is designed to turn red and remain red whenever the temperature of the smooth area of glass exceeds 115 degrees Fahrenheit.