Patent Application
20120100492
The present disclosure generally relates to appliances, and more particularly to a surface burner lockout system for a cooking appliance.
Cooking appliances with cooking surfaces that include electric or gas surface heating elements or burners will typically include a lockout feature. The lockout feature provides the ability to lock out or disable the operation of the surface heating elements on the cooktop surface. When a lockout device is deactivated, a check is made prior to reactivation to ensure that none of the appliance or burner controls are in the activated position. If a burner control were to be in an activated position when the lockout device is deactivated, there is the chance that the surface heating element could come on unexpectedly. It is also not desirable to activate the lockout device while the surface heating elements are in use.
A typical implementation will utilize an electronic range control (ERC) device. The electronic range control device will generally monitor and determine a state of the surface heating elements before operation (activation or deactivation) of the lockout device is allowed. This requires additional components, circuitry and connections to sense the state of each surface heating element. It would be advantageous to be able to sense the state of the lockout device in order to determine the state of the surface heating element.
Accordingly, it would be desirable to provide a system that addresses at least some of the problems identified above.
As described herein, the exemplary embodiments overcome one or more of the above or other disadvantages known in the art.
One aspect of the exemplary embodiments relates to a lockout control system for a cooktop appliance having a surface heating unit. In one embodiment the lockout control system includes a controller coupled to the cooktop, a lockout device coupled to the controller, a surface burner state switch coupled between the controller and the lockout device, the surface burner state switch configured to prevent operation of the lockout device when the surface heating unit is enabled.
Another aspect of the disclosed embodiments relates to an appliance. In one embodiment the appliance includes a heating unit configured to switch between an active and de-activated state, a control for the heating unit, a burner state switch coupled to the control for the heating unit, and a lockout device configured to switch between a locked and unlocked state of the heating unit; wherein when the appliance generates a lockout device select command to change a state of the lockout device, the state of the lockout device is monitored to determine if the heating unit is in the active state.
A further aspect of the disclosed embodiments relates to a method. In one embodiment the method includes determining a state of a heating unit in an appliance using a controller. The controller generates a lockout device select command, monitors a state of a lockout device for a pre-determined time period, determines if the lockout device changes state responsive to the lockout device select command during the pre-determined time period, and determines that a state of the heating unit is enabled if the lockout device does not change state during the pre-determined time period.
These and other aspects and advantages of the exemplary embodiments will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims. Moreover, the drawings are not necessarily drawn to scale and unless otherwise indicated, they are merely intended to conceptually illustrate the structures and procedures described herein. In addition, any suitable size, shape or type of elements or materials could be used.
In the drawings:
Referring to
As is shown in
The cooktop 120 includes one or more surface heating units or burner elements, generally referred to as surface heating units 125. Although five surface heating units or burner elements are shown in this example, in alternate embodiments, the range 100 could include more or less than five surface heating units 125.
The range 100 also includes an oven unit 110. Although the aspects of the disclosed embodiments are described herein with respect to the single oven configuration shown in
In one embodiment, the cabinet 101 of the range 100 includes a control surface 108 that supports one or more controls, generally referred to herein as burner control 115. The burner control 115 shown in
The cabinet 101 also includes a control panel 130, also referred to as a user interface. The control panel 130 can also include a display 131. One aspect of the control panel 130 is to control the general operations of the range 100, including the oven 110 and cooktop 120, as well as provide feedback to the user. The control panel 130 can include one or more controls or switches 135 that can be used to provide control inputs and commands for one or more of the functions of the range 100, including the oven 110 and cooktop 120. In one embodiment, the controls 135 can be in the form of push buttons or electronic switches.
In one embodiment, the oven 100 includes a controller 140. The controller 140 is coupled to, or integrated within, the control panel 130 and configured to receive inputs and commands from for example, the controls 115 and 135, and control the various operations and functions of the oven 100. In one embodiment, the controller 140 can include or comprise an electronic range control.
A lockout request or command from the controller 140 will generally cause the lockout device 210 to transition to the locked state and disable the cooktop 120, and in particular the surface heating units 125. A de-activate or disable lockout request or command will generally cause the lockout device 210 to transition to the unlocked state, allowing the cooktop 120 to be active. Both the lockout command and disable lockout command will generally be referred to herein as a lockout device select command. Although the aspects of the disclosed embodiments are generally described herein with respect to the locking of the cooktop 125, the locking device 210 can also be configured to lock the oven unit 110 as well, and prevent the inadvertent activation of the oven unit 110.
In one embodiment, the lockout device 210 activation is initiated via user interaction with the control panel 130 or automatically by the controller 140. The controller 130 activates the lockout device 210. In alternate embodiments, the lockout device 210 can be activated in any suitable manner. For example, the user may manually request that the lockout mode be enabled by pressing a button 135 on the control panel 130. Or, where the controller 140 is configured to automatically generate a lockout command, after a suitable period of inactivity of the oven 110 or cooktop 120, the lockout device select or enable command is automatically transmitted to the lockout device 210. Requests to de-activate a lockout state are typically made via the control panel 130, although in one embodiment, such unlock commands can be automatically generated as well.
In one embodiment, the range 100 can include an indicator 212 that is configured to indicate the status or state of the lockout device 210. The indicator 212, which, in one embodiment, is part of the control surface 108 or control panel 130, can be any suitable visual indicator such as, for example, an LED or light on the control panel 130. When the lockout device 210 is enabled or active, meaning that the cooktop 120 is in the locked state, the LED 212 is illuminated. In one embodiment, the indicator 212 can also include an audio device or component.
The controller 140 is configured to monitor a state of the lockout device 210 and determine when the lockout device 210 changes state. The aspects of the disclosed embodiments generally encompass three states. An unlocked state, a locked state and a transition state. In the unlocked state or mode, the lockout device 210 is not enabled or active, meaning the cooktop 120 is not locked. In the locked state, the lockout device 210 is enabled or active, meaning the cooktop 120 is locked or disabled. The third state, the transition state, is a state where the lockout device 210 is neither unlocked or locked, and the valve lock motor 210 is being driven. In this state, the lockout device 210 is transitioning to one of the unlocked or locked state. A change of state can generally be considered either a transition from the unlocked to locked state or the locked to unlocked state. It is a feature of the aspects of the disclosed embodiments to determine the state of the surface heating units 125 by monitoring the state, or change in state of the lockout device 210. Although the aspects of the disclosed embodiments are described herein with respect to the state of the surface heating unit 125, the position of the burner control 115 determines the state of the surface heating unit 125. Generally, if the burner control 115 for one of the surface heating units 125 is in position other than OFF, the aspects of the disclosed embodiments will prevent the lockout device 210 from changing state. For example, when the range 100 is in a locked state and a request to de-activate the lockout is requested, the controller 140 is configured to generate a lockout device select command to enable the lockout device 210 to change from the locked to unlocked state. In accordance with the aspects of the disclosed embodiments, the lockout device 210 will only change state if all of the burner controls 115 are in the OFF position. The controller 140 monitors the state of the lockout device 210 for a pre-determined time period to determine if the lockout device 210 changes state. If the lockout device 210 does not change state within the pre-determined time period, it is determined that one or more of the burner controls 115 is not in the OFF position. The aspects of the disclosed embodiments provide the advantage that the controller 140 does not need to separately monitor the state of each surface heating unit 125. Rather, only the state of the lockout device 210 needs to be monitored. The aspects of the present disclosure eliminate the need for additional sensors or connections between the surface heating units 125 and the controller 140. A similar process occurs for a request to lock the cooktop 120.
As is shown in
The surface burner state switch 320 is configured to monitor a state of each burner control 115. In one embodiment, the burner state switch 320 comprises one or more interlock switches 325, where each interlock switch 325 is associated with a burner control 115 for a surface heating element 125. The interlock switches 325 are connected together to form a series circuit connection. When any one of the interlock switches 325 is open, meaning that a burner control 115 is in a position other than OFF, the circuit connection between the lockout enable relay 314 and the lockout device 210 is in an open state. An open state of any one of the interlock switches 325 will prevent the lockout device 210 from operating by interrupting the power control circuit connection between power elements 302 and 304.
In one embodiment, each switch 325 can be part of an assembly mounted on a shaft of the burner control 115. In this example, the interlock switch 325 is a normally closed switch, which is closed when the burner control 115 is in the OFF position. If the burner control 115 selects any other mode or position, the interlock switch 325 is OPEN. In one embodiment, the interlock switch 325 is a limit switch that is activated by a cam on a shaft of the burner knob control 115 as it is turned from the OFF to the ON position or any other position. The lockout device 210 is prevented from operating, or changing state, if any of the burner controls 115 are in a position other than OFF, and any of the interlock switches is OPEN. In alternate embodiments, the interlock switch 325 can comprise any suitable switch for interrupting a circuit connection when the burner control knob 115 is in any position other than OFF.
The electronic range control 310 is configured to receive lock state transition requests and generate suitable lock state change commands. For example, the user can enter lock state requests on the control panel 130. In one embodiment, the electronic range control 310 includes a lockout enable relay 314 that is configured to provide a circuit connection between the power source 302 and the lockout device 210 when the lockout enable relay 314 is enabled. The lockout device select or enable command 306 will generally cause the lockout enable relay 314 to close for so long as the lockout device select command 306 is active. In one embodiment, the lockout enable relay 314 is configured to remain in the enable or closed state for a pre-determined time period after the lockout device select command 306 is received. The pre-determined time period is generally sufficient to allow the lockout device 210 to fully transition from one state to the other and can be in the range of approximately 4 to 30 seconds. In alternate embodiments, the approximate time period for the lockout device 210 to fully transition from one state to another is dependent upon the type of motor used for the lockout device 210. For example, when a lockout request is generated, the electronic range control 310 can issue a lockout device select command 306. The lockout device select command 306 closes the lockout enable relay 314. The lockout relay enable relay 314 remains closed until the desired state is reached. At the pre-determined period of time, the state of the lockout device 210 is check to determined whether or not the state has transitioned. If the state has transitioned, the lockout device select command 306 causes the lockout enable relay 314 to open. This can include generating a lockout device de-select command. In one embodiment, the lockout device select command 306 comprises a signal having a duty cycle sufficient to allow the lockout device 210 to change from one state to the other during the first part of the signal, after which the lockout device 210 is disabled.
In one embodiment, the processor 312 of the electronic range control 310 is also configured to monitor a state of the lockout device 210. In this example, the range 100 is a gas powered range, and the lockout device 210 is configured to control the flow of gas to the range 100. A gas valve open switch 316 and a gas valve closed switch 318 provide control signal inputs to the electronic range control 310. In one embodiment, the gas valve open switch 316 and gas valve closed switch 318 are controlled by the lockout device 210. When a request to activate or deactivate a lockout is received, the electronic range control 310 is configured to determine a state of the lockout device 210 by monitoring each of the gas valve open and gas valve closed switches 316, 318. If the gas valve open switch 316 is closed, this generally indicates that the lockout device 210 is in the unlocked state. If the gas valve closed switch 318 is closed, this generally indicates that the lockout device 210 is in the locked state.
Once the lockout device select command 306 is issued, the electronic range control 310 is configured to monitor the state of each of the switches 316, 318. In one embodiment, the state of the switches 316, 318 is monitored for the predetermined period of time. If a change in state occurs, meaning that one of the switches 316, 318 opens and the other 318, 316 closes, the lockout device 210 has changed states. If no change from the initial position of the switches 316, 318 is detected, the lockout device 210 has not changed state, meaning that one of the interlock switches 325 is in an open state. Thus, by monitoring the state of the interlock device 210 after a lockout device select command 306 is generated, the state of the surface heating units 125 can be determined.
If it is determined 410 that the surface heating elements 125 are not active based on the change of state of the lockout device 210, the range 100 is now in the lockout or disabled state 416 (having previously been in the idle state 402).
If it is determined 510 that the surface heating units 125 are not active based on the change of state of the lockout device 210, the range 100 is now the unlocked or idle state 516 (having previously been in the lockout state 502).
As will generally be understood in the art, self-cleaning or pyrolitic ovens operate in the self-cleaning mode at temperatures that can in some cases exceed 800 degrees Fahrenheit. Safety regulations and standards require that the doors, such as door 112 in
In one embodiment, if after the completion of a self-clean operation and sufficient cooling of the oven unit 110, the de-select lockout command 506 cannot cause the deactivation of the lockout device 210 due to a surface heating unit 125 being active, in one embodiment, the door(s) 110 of the oven unit 110 can unlock, but the surface heating units 125 remain disabled due to the locked state of the lockout device 210.
The disclosed embodiments may also include software and computer programs incorporating the process steps and instructions described above. In one embodiment, the programs incorporating the process described herein can be stored on or in a computer program product and executed in one or more computers. The controller 140 illustrated in
The controller 140 may be linked to another computer system or controller (not shown), such that the controllers are capable of sending information to each other and receiving information from each other. In one embodiment, the controller 140 could include a server computer or controller adapted to communicate with a network, such as for example, a wireless network or the Internet.
The controller 140 is generally adapted to utilize program storage devices embodying machine-readable program source code, which is adapted to cause the controller 140 to perform the method steps and processes disclosed herein. The program storage devices incorporating aspects of the disclosed embodiments may be devised, made and used as a component of a machine utilizing optics, magnetic properties and/or electronics to perform the procedures and methods disclosed herein. In alternate embodiments, the program storage devices may include magnetic media, such as a diskette, disk, memory stick or computer hard drive, which is readable and executable by a computer. In other alternate embodiments, the program storage devices could include optical disks, read-only-memory (“ROM”) floppy disks and semiconductor materials and chips.
The controller 140 may also include one or more processors, such as processor 401, for executing stored programs, and may include a data storage or memory device on its program storage device for the storage of information and data. The computer program or software incorporating the processes and method steps incorporating aspects of the disclosed embodiments may be stored in one or more computer systems or on an otherwise conventional program storage device.
The aspects of the disclosed embodiments allow the state of the surface burner units on a cooktop to be determined by monitoring the state of the lockout device. The need for separate inputs to an electronic range control to monitor the state of each surface burner unit is eliminated. The state of the lockout device provides an indirect means for determining the state of the surface burner elements.
Thus, while there have been shown, described and pointed out, fundamental novel features of the invention as applied to the exemplary embodiments thereof, it will be understood that various omissions and substitutions and changes in the form and details of devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the invention. Moreover, it is expressly intended that all combinations of those elements and/or method steps, which perform substantially the same function in substantially the same way to achieve the same results, are within the scope of the invention. Moreover, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.
