Gas cooktop with defined simmer settings

Abstract

A control unit is provided for use on a gas appliance. The control unit includes an urged member and a rotor, the rotor being attached to a user input device and being rotatable to a plurality of positions, the plurality of positions including a number of positions that correspond to a number of simmer settings of a gas valve. The rotor has a plurality of engagement features, each of which corresponds to one of the simmer settings, the urged member being engaged with one of the engagement features when the rotor is in one of the simmer settings. The rotation of the rotor requires a first smaller force to be applied when the rotor is in a position other than one of the simmer settings, and rotation of the rotor requires a second larger force to be applied when the urged member is engaged with one of the engagement features.

What is claimed is: 
     
         1 . A domestic gas appliance, comprising:
 a cooktop having a top surface;   a user input device;   a gas burner located on the top surface;   a gas valve fluidly coupled to the gas burner, the gas valve being configured to selectively deliver gas to the gas burner;   an igniter configured to selectively ignite the gas delivered to the gas burner; and   a control unit that controls a flow of gas through the gas valve and to the gas burner, the control unit having
 a housing, 
 an urged member attached to the housing, and 
 a rotor attached to the housing and the user input device and having an axis, the rotor being rotatable around the axis to a plurality of positions, the plurality of positions including a number of positions that correspond to a number of simmer settings of the gas valve, the rotor having
 a main body, and 
 a plurality of engagement features on the main body, each of the engagement features corresponding to one of the simmer settings, the urged member being engaged with one of the engagement features when the rotor is in a position corresponding to one of the simmer settings, 
 
   wherein rotation of the rotor requires a first force of rotation to be applied by the user when the rotor is in a position other than one of the simmer settings,   rotation of the rotor requires a second force of rotation to be applied by the user when the urged member is engaged with one of the engagement features, and   the second force is greater than the first force.   
     
     
         2 . The domestic appliance of  claim 1 , wherein each simmer setting is a repeatable setting in which the gas valve is open for a predetermined open portion of a given minute and in which the gas valve is closed for a predetermined closed portion of the given minute, the sum of the open portion and the closed portion being the entire given minute, and
 each simmer setting has a different open-to-closed ratio.   
     
     
         3 . The domestic appliance of  claim 2 , wherein all of the simmer settings produce less heat per unit of time than a lowest heat setting where the gas valve is constantly open. 
     
     
         4 . The domestic appliance of  claim 3 , wherein the user input device is a rotatable knob, and the rotor is rotated when rotatable knob is rotated. 
     
     
         5 . The domestic appliance of  claim 4 , wherein the engagement features are indentations on a perimeter of the rotor. 
     
     
         6 . The domestic appliance of  claim 5 , wherein the urged member is a spring actuated plunger. 
     
     
         7 . The domestic appliance of  claim 1 , wherein the engagement features are indentations on a perimeter of the rotor. 
     
     
         8 . A control unit for use on a domestic gas appliance having a cooktop with a top surface, a user input device, a gas burner located on the top surface, and a gas valve fluidly coupled to the gas burner, the gas valve being configured to selectively deliver gas to the gas burner, the control unit comprising:
 a housing,   an urged member attached to the housing, and   a rotor attached to the housing and having an axis, the rotor being configured to be attached to the user input device, the rotor being rotatable around the axis to a plurality of positions, and the plurality of positions including a number of positions that correspond to a number of simmer settings of the gas valve, the rotor having
 a main body, and 
 a plurality of engagement features on the main body, each of the engagement features corresponding to one of the simmer settings, the urged member being engaged with one of the engagement features when the rotor is in a position corresponding to one of the simmer settings, 
   wherein the control unit is configured to control a flow of gas through the gas valve and to the gas burner,   rotation of the rotor requires a first force of rotation to be applied by the user when the rotor is in a position other than one of the simmer settings,   rotation of the rotor requires a second force of rotation to be applied by the user when the urged member is engaged with one of the engagement features, and   the second force is greater than the first force.   
     
     
         9 . The control unit of  claim 8 , wherein each simmer setting is a repeatable setting configured such that the gas valve is open for a predetermined open portion of a given minute and such that the gas valve is closed for a predetermined closed portion of the given minute, the sum of the open portion and the closed portion being the entire given minute, and
 each simmer setting has a different open-to-closed ratio.   
     
     
         10 . The control unit of  claim 9 , wherein all of the simmer settings are configured to produce less heat per unit of time than a lowest heat setting where the gas valve is constantly open. 
     
     
         11 . The control unit of  claim 10  wherein the user input device is a rotatable knob, and the rotor is rotated when rotatable knob is rotated. 
     
     
         12 . The control unit of  claim 11 , wherein the engagement features are indentations on a perimeter of the rotor. 
     
     
         13 . The control unit of  claim 12 , wherein the urged member is a spring actuated plunger. 
     
     
         14 . The control unit of  claim 8 , wherein the engagement features are indentations on a perimeter of the rotor. 
     
     
         15 . A method of controlling an amount of heat generated by a gas burner on a domestic gas appliance, the method comprising:
 controlling with a control unit a flow of gas through a gas valve and to the gas burner by
 defining a plurality of simmer settings of the gas valve with a corresponding plurality of engagement features on a rotor of the control unit; and 
 engaging an urging member of the control unit with one of the engagement features to select one of the defined simmer settings, 
   wherein rotation of the rotor requires a first force of rotation to be applied by a user when the rotor is in a position other than one of the simmer settings,   rotation of the rotor requires a second force of rotation to be applied by the user when the urged member is engaged with one of the engagement features, and   the second force is greater than the first force.   
     
     
         16 . The method of  claim 15 , wherein each simmer setting is a repeatable setting configured such that the gas valve is open for a predetermined open portion of a given minute and such that the gas valve is closed for a predetermined closed portion of the given minute, the sum of the open portion and the closed portion being the entire given minute, and
 each simmer setting has a different open-to-closed ratio.   
     
     
         17 . The method of  claim 16 , wherein all of the simmer settings are configured to produce less heat per unit of time than a lowest heat setting where the gas valve is constantly open. 
     
     
         18 . The method of  claim 17  wherein the user input device is a rotatable knob, and the rotor is rotated when rotatable knob is rotated. 
     
     
         19 . The method of  claim 18 , wherein the engagement features are indentations on a perimeter of the rotor. 
     
     
         20 . The method of  claim 19 , wherein the urged member is a spring actuated plunger.