Gas cooking appliance

Abstract

A gas cook top includes a plurality of gas burners arranged on a cook top surface to accommodate a variety of cooking vessels. Each burner is associated with a valve for varying the flow of fuel gas from a supply to the burner, so that the heat output of the burner can be varied in use. The cook top includes a controller operationally coupled to an actuator associated with each valve for varying the position of each valve. The controller is configured to receive an input from a user via a user interface and operate the actuator to move a valve to a desired position along a predetermined path, wherein the path may not be the shortest distance between the current position and the desired position of the valve.

1 . A cook top comprising:
 a burner,   a user interface configured to receive a user input indicative of a desired burner setting,   a valve having a fully closed position and operated by an actuator to vary the flow of fuel gas from a supply to said burner,   a controller operationally coupled to said actuator and having two modes, wherein when in a first mode:
 said controller opens said valve, 
 ignites said burner and detects the presence of a flame, 
 while maintaining detection of the presence or absence of said flame, progressively closes said valve until said flame is no longer detected, and 
 records the distance between said fully closed position of said valve and the last position of said valve when said flame was detected, as a reference offset, and 
   when in said second mode:
 said controller operates said burner according to said user input. 
   
     
     
         2 . A cook top as claimed in  claim 1 , wherein said valve position when said flame was last detected is used as the valve position corresponding to the lowest setting of said burner. 
     
     
         3 . A cook top as claimed in  claim 2 , wherein said cook top includes a plurality of burners and said controller records a reference offset for each said burner. 
     
     
         4 . A cook top as claimed in  claim 3 , wherein said controller looks up a look up table to determine how to move said valve to get from a current position to a desired position based on said input. 
     
     
         5 . A cook top as claimed in  claim 4 , wherein said look up table includes the distance from every burner setting to every other burner setting, and
 said table records said reference offset for each burner as the distance from said fully closed position to a lowest burner setting.   
     
     
         6 . A cook top as claimed in  claim 4 , wherein said look up table includes the distance from each burner setting to the next lower burner setting, and
 said table records said reference offset for each burner as the distance from said fully closed position to a lowest burner setting.   
     
     
         7 . A cook top as claimed in  claim 4 , wherein said actuator is a stepper motor, and said lookup table stores a value for each burner setting that is the number of steps that that setting is above the next lowest setting, and
 said table records said reference offset valve for the lowest burner setting.   
     
     
         8 . A cook top as claimed in  claim 4 , wherein said actuator is a stepper motor, and the number of steps from said fully closed position to the position corresponding to each burner setting is the sum of said reference offset and all the lookup table values from the lowest setting to each burner setting. 
     
     
         9 . A cook top as claimed in any one of  claim 1 , wherein said controller stores the current distance from said fully closed position for each valve. 
     
     
         10 . A cook top as claimed in any one of  claim 1 , wherein said controller utilizes a predetermined relationship to determine how to move said valve to get from a current position to a desired position based on said input. 
     
     
         11 . A cook top as claimed in  claim 10 , wherein said relationship maps the distance from every burner setting to every other burner setting, and
 said controller records said reference offset for each burner as the distance from said fully closed position to a lowest burner setting.   
     
     
         12 . A cook top as claimed in  claim 1 , wherein said controller looks up a look up table to determine how to move said valve to get from a current position to a desired position based on said input. 
     
     
         13 . A cook top as claimed in  claim 2 , wherein said controller looks up a look up table to determine how to move said valve to get from a current position to a desired position based on said input. 
     
     
         14 . A method of operating a burner comprising:
 opening a valve having a fully closed position to deliver a fuel gas to said burner,   igniting said burner and detecting a flame,   while continuing to detect the presence or absence of said flame, progressively closing said valve until said flame is no longer detected, and   recording the distance between said fully closed position of said valve and the last position of said valve when said flame was detected, as a reference offset.   
     
     
         15 . A method of operating a burner comprising:
 opening a fuel gas valve to supply fuel gas to a burner,   igniting said burner and detecting the presence of a flame,   while maintaining the detection of the presence or absence of said flame, progressively closing said valve until said flame is no longer detected, and   recording the position of said valve at the last point that said flame was detected as a reference offset.