Cooking appliance and method

Abstract

A cooking appliance and method includes a housing comprising an interior wall at least partially defining a cooking chamber, a temperature sensor coupled to the interior wall and configured to provide a signal indicative of a temperature within the cooking chamber, and a controller in signal communication with the temperature sensor and operably coupled to the controllable valve assembly.

What is claimed is: 
     
         1 . A cooking appliance comprising:
 a housing comprising an interior wall at least partially defining a cooking chamber and having an access opening;   a heating element located within the housing;   a temperature sensor and configured to provide a signal indicative of a temperature within the cooking chamber;   a chamber inlet in the interior wall fluidly coupling the cooking chamber to a source of air;   a controllable valve assembly fluidly coupled to the chamber inlet and movable between an opened position, allowing airflow into the cooking chamber through the chamber inlet, and a closed position, inhibiting airflow through the chamber inlet;   a controller in signal communication with the temperature sensor and operably coupled to the controllable valve assembly, with the controller configured to:
 determine at least one temperature condition within the cooking chamber based on the signal indicative of the temperature within the cooking chamber; 
 compare the at least one temperature condition with at least one predetermined threshold value; and 
 controllably operate the controllable valve assembly based on the comparison. 
   
     
     
         2 . The cooking appliance of  claim 1 , wherein the controller is configured to actuate the controllable valve assembly to the closed position when the at least one temperature condition satisfies the comparison by meeting or exceeding the at least one predetermined threshold value. 
     
     
         3 . The cooking appliance of  claim 1 , wherein the at least one temperature condition comprises at least one of a single temperature or a temperature rate of change, and the at least one predetermined threshold value comprises a corresponding at least one of a maximum temperature or a maximum temperature rate of increase. 
     
     
         4 . The cooking appliance of  claim 1 , wherein the at least one predetermined threshold value comprises a first threshold value and a second threshold value, and wherein the controller is further configured to:
 perform a first comparison by comparing the at least one temperature condition with the first threshold value; and   perform a second comparison by comparing the at least one temperature condition with the second threshold value.   
     
     
         5 . The cooking appliance of  claim 4 , wherein the controller is configured to actuate the controllable valve assembly to the closed position when the at least one temperature condition satisfies the first comparison. 
     
     
         6 . The cooking appliance of  claim 4 , wherein the first threshold value comprises a positive rate of temperature change with the controllable valve assembly in the opened position, and wherein the second threshold value comprises a non-negative rate of temperature change with the controllable valve assembly in the closed position. 
     
     
         7 . The cooking appliance of  claim 4 , wherein the controller is operably coupled to the heating element and further configured to cease a heating operation of the heating element when the at least one temperature condition satisfies the second comparison. 
     
     
         8 . The cooking appliance of  claim 7 , wherein the controller is configured to at least one of modify a supply of power or cut a supply of power to the heating element to cease the heating operation. 
     
     
         9 . The cooking appliance of  claim 8 , wherein the controller further comprises a thermostat and a trip mechanism configured to automatically cut the supply of power to the heating element when the at least one temperature condition satisfies the second comparison. 
     
     
         10 . The cooking appliance of  claim 1 , wherein the at least one predetermined threshold value is indicative of a presence of at least one of smoldering, overheating, deflagration, or smoke within the cooking chamber, and wherein the controllable valve assembly is configured to inhibit the presence of the at least one of smoldering, overheating, deflagration, or smoke when in the closed position. 
     
     
         11 . The cooking appliance of  claim 1 , wherein the heating element comprises a microwave generator for providing microwave radiation to the cooking chamber. 
     
     
         12 . The cooking appliance of  claim 1 , wherein the controllable valve assembly is located adjacent the chamber inlet. 
     
     
         13 . The cooking appliance of  claim 1 , wherein the controllable valve assembly comprises a rotatable flap and an actuator configured to rotate the rotatable flap between at least the opened position and the closed position. 
     
     
         14 . The cooking appliance of  claim 1 , further comprising:
 an air inlet located on the housing;   a chamber outlet located in the cooking chamber; and   a chamber air flow path extending through at least the air inlet, the chamber inlet, the cooking chamber, and the chamber outlet.   
     
     
         15 . A method of operating a cooking appliance having a heating element, the method comprising:
 sensing at least one temperature in a cooking chamber of the cooking appliance, with the cooking chamber having a chamber inlet, and with a controllable valve assembly disposed in fluid communication with the chamber inlet;   determining at least one temperature condition within the cooking chamber based on the at least one temperature;   comparing the at least one temperature condition with at least one predetermined threshold value; and   operating the controllable valve assembly to inhibit a flow of air into the cooking chamber when the at least one temperature condition satisfies the comparison.   
     
     
         16 . The method of  claim 15 , wherein the operating the controllable valve assembly comprises moving the controllable valve assembly to a closed position. 
     
     
         17 . The method of  claim 15 , wherein the at least one predetermined threshold value is indicative of a presence of at least one of smoldering, overheating, deflagration, or smoke within the cooking chamber. 
     
     
         18 . The method of  claim 17 , wherein the at least one predetermined threshold value comprises a first threshold value and a second threshold value each indicative of the presence of at least one of smoldering, overheating, deflagration, or smoke within the cooking chamber. 
     
     
         19 . The method of  claim 18 , further comprising:
 performing a first comparison by comparing the at least one temperature condition with the first threshold value;   operating the controllable valve assembly to inhibit the flow of air when the at least one temperature condition satisfies the first comparison;   performing a second comparison by comparing the at least one temperature condition with the second threshold value; and   ceasing a heating operation by cutting power to the heating element when the at least one temperature condition satisfies the second comparison.   
     
     
         20 . The method of  claim 15 , wherein the at least one temperature condition comprises at least one of a cooking chamber temperature or a temperature rate of change.