Methods and apparatus for a gas range

Description

BACKGROUND OF THE INVENTION

This invention relates generally to gas cooking appliances, and, more particularly, to a gas shutoff valve assembly for a cooking appliance.

Gas fired stoves, ovens, and ranges typically include one or more gas heating elements coupled to a main gas line to the appliance and providing fuel to the heating elements, sometimes referred to as burners. In a domestic range, a gas line is connected to a distribution manifold within the appliance to direct gas to a plurality of surface burner elements on a cooktop or to oven elements within an oven cavity. Operation of the burners and cooking elements is usually accomplished with burner control knobs mounted on either a front or back wall of the appliance. When a control knob is actuated, fuel is supplied to associated heating elements and an ignition module creates a spark to ignite the gas and produce a flame.

Some gas cooking appliances include a valve to prevent gas flow to the burners when actuated (sometimes referred to as a lockout condition), and thus the appliance can be rendered inoperable as desired. In some known gas cooking appliances, a self-clean feature is necessary to clean the gas cooking appliances without manual labor, which is apparently convenient for a user.

However, when a gas cooking appliance is operated in a self-clean mode, some international standards require a gas range to meet predetermined temperature limits. Specifically, because of the relatively large amount of heat that is generated during the self-clean mode, relatively large quantities of insulation are installed to insulate the oven cavity. Moreover, if the cooking appliance burners are operated during the self-clean mode, additional quantities of insulation are installed to meet the international standards.

BRIEF DESCRIPTION OF THE INVENTION

In one aspect, a gas cooking appliance is provided. The gas cooking appliance includes at least one gas surface burner element, a controller configured to receive a signal indicative of a self-clean mode, and a gas lockout valve assembly coupled in line with the surface burner element, wherein the gas lockout valve assembly is configured to close in response to receiving the self-clean signal such that gas flow to the surface burner element is stopped during the self-clean mode.

In another aspect, a gas range is provided. The gas range includes a cabinet, a plurality of gas surface burners coupled to the cabinet, a controller configured to receive a signal indicative of a self-clean mode, and a gas lockout valve assembly coupled between the plurality of gas surface burner elements and a gas line, the gas lockout valve assembly is configured to close in response to receiving the self-clean signal such that gas flow to the surface burner elements is stopped during the self-clean mode.

In a further aspect, a method for automatically shutting off a gas supply during a self-clean process of a gas cooking appliance is provided. The appliance includes a plurality of surface burner elements, a gas lockout valve assembly having a solenoid coupled to the surface burner elements, and a controller operatively coupled to the gas lockout valve assembly. The method includes inputting an instruction of a self-clean mode to the controller, transferring a signal of a self-clean mode from the controller to the gas lockout valve assembly, and shutting off the gas supply via the gas lockout valve assembly in response to receiving the self-clean signal from the controller.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an exemplary free standing gas range.

FIG. 2 is a side elevational view of the range shown in FIG. 1 partly broken away.

FIG. 3 is a cross sectional schematic view of an exemplary gas lockout valve assembly for the range shown in FIGS. 1 and 2.

FIG. 4 is a plan view of a control panel interface for the range shown in FIGS. 1 and 2.

FIG. 5 is a schematic block diagram of a control system for the range shown in FIGS. 1 and 2.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 illustrates a gas cooking appliance in the form of a free standing gas range 10 including an outer body or cabinet 12 that incorporates a generally rectangular cooktop 14. An oven, not shown, is positioned below cooktop 14 and has a front-opening access door 16. A range backsplash 18 extends upward of a rear edge 20 of cooktop 14 and contains various control selectors (not shown) for selecting operative features of heating elements for cooktop 14 and the oven. It is contemplated that the present invention is applicable, not only to cooktops which form the upper portion of a range, such as range 10, but to other forms of cooktops as well, such as, but not limited to, free standing cooktops that are mounted to kitchen counters. Therefore, gas range 10 is provided by way of illustration rather than limitation, and accordingly there is no intention to limit application of the present invention to any particular appliance or cooktop, such as range 10 or cooktop 14. In addition, it is contemplated that the present invention is applicable to duel fuel cooking appliances, e.g., a gas cooktop with an electric oven.

Cooktop 14 includes four gas fueled surface burners 22, 24, 26, 28 which are positioned in spaced apart pairs 22, 24 and 26, 28 positioned adjacent each side of cooktop 14. Each pair of burners 22, 24 and 26, 28 is surrounded by a recessed area (not shown in FIG. 1) respectively, of cooktop 14. The recessed areas are positioned below an upper surface 29 of cooktop 14 and serve to catch any spills from cooking utensils being used with cooktop 14. Each burner 22, 24, 26, 28 extends upwardly through an opening in cooktop 14, and a grate assembly 30, 32 is positioned over each respective pair of burners, 22, 24 and 26, 28. Each grate assembly 30, 32 includes a respective frame 34, 36, and separate utensil supporting grates 38, 40, 42, 44 are positioned above the cooktop recessed areas and overlie respective burners 22, 24, 26, 28 respectively.

The construction and operation of the range heating elements, including cooktop gas burners 22, 24, 26, 28 are believed to be within the purview of those in the art without further discussion.

FIG. 2 illustrates range 10 mounted adjacent a kitchen wall 50. Range 10 includes a front panel 52, a rear wall 54, laterally spaced side walls 56 and 58, and backsplash 18. Gas burners 22, 24, 26, and 28 of cooktop 14 are connected by a gas line 62 to a manifold 64. A plurality of burner knobs 65 are mounted on front panel 52 of range 10 in front of cooktop 14. A gas appliance connector hose 70 is connected between a main gas line 68 and gas line manifold 64, and a gas lockout valve assembly 66 is connected to or in line with gas line manifold 64 along appliance connector hose 70. Gas lockout valve assembly 66 therefore regulates gas flow between main gas line 68 and gas manifold 64. While lockout valve assembly 66 is illustrated coupled to appliance connector hose 70 between backsplash 18 and manifold 64, it is contemplated that gas lockout assembly 66 may be located elsewhere in appliance 10, including but not limited to, a location in the immediate vicinity of the main gas line connection to appliance 10.

When lockout valve assembly 66 is in an open position, gas flow is channeled through appliance connector hose 70 to manifold 64 and to surface burners 22, 24, 26, and 28 when the applicable control knob 65 is actuated. When lockout valve assembly 66 is in a closed position, gas flow is prevented from entering into gas manifold 64 from appliance connector hose 70, thereby blocking gas flow to surface burners 22, 24, 26, and 28 even though the applicable control knob 65 may be opened. Surface burners 22, 24, 26, and 28 (as well as other heating elements connected to manifold 64) are thereby inoperative and gas flow is avoided.

FIG. 3 is a cross sectional schematic view of an exemplary embodiment of a gas lockout valve assembly 66 including a valve 80 adapted for connection to a gas line such as gas line 70 (shown in FIG. 2). In one embodiment, gas lockout valve assembly 66 includes an electric motor 82 for actuating valve 80 to open or close a fluid path or passage 81 through valve 80 to supply or not supply gas to appliance gas manifold 64 (shown in FIG. 2) and therefore to associated surface burner elements. In another embodiment, gas lockout valve assembly 66 includes a solenoid (not shown) for actuating valve 80 to open or close a fluid path or passage 81 through valve 80 to supply or not supply gas to appliance gas manifold 64 (shown in FIG. 2) and therefore to associated surface burner elements 22, 24, 26, and 28. In the exemplary embodiment, valve 80 is a ½ inch NPT (Normal Pipe Thread) panel mount ball valve including an actuation shaft 84 rotatable about an axis 88 through the valve. In one embodiment, valve shaft 84 is operatively coupled to motor 82, and more specifically to a motor output shaft 85 extending from a motor output gear 86 through a cam 90 that receives motor shaft 85 and valve shaft 84. As motor 82 is energized, motor shaft 85 is rotated and causes valve shaft 84 to be rotated. As valve shaft 84 is rotated, a spherical valve element mechanism is displaced from or seated to valve seats within a flow path to control the flow of gas through valve 80.

In another embodiment, valve shaft 84 is operatively coupled to a solenoid 83 such that energizing solenoid 83 causes valve 80 to open or close a fluid path or passage 81 through valve 80 to supply or not supply gas to appliance gas manifold 64 (shown in FIG. 2) and therefore to associated surface burner elements. It is believed that such valve mechanisms are readily appreciated by those in the art without further explanation, and it is contemplated that other types of valves familiar to those in the art could likewise be employed without departing from the scope of the present invention.

FIG. 4 illustrates an exemplary input interface panel 130 that may be used with range 10 (shown in FIGS. 1 and 2). Interface panel 130 includes a display 132 and a plurality of input selectors 134 in the form of touch sensitive buttons or keypads for accessing and selecting oven features. In alternative embodiments, other known input selectors are used in lieu of touch sensitive switches.

More specifically, input selectors 134 are divided into two groups 136, 138. Group 136 includes a SURFACE LIGHT keypad 139, a BAKE keypad 140, a BROIL keypad 142, an OVEN LIGHT keypad 144, a CONVECTION BAKE keypad 146, a CONVECTION ROAST keypad 148, a CLEAN keypad 150, a FAVORITE RECIPE keypad 152, a MULTI-STAGE keypad 154, a temperature up () slew keypad 156 and a temperature down () slew keypad 158. Group 138 includes an hour up () slew keypad 160 and an hour down () slew keypad 162, a minute up () slew keypad 164 and a minute down () slew keypad 166, a START keypad 168, a CLEAR/OFF keypad 170, a LOCK keypad 172, a COOK TIME keypad 174, a DELAY START keypad 176, a POWER LEVEL keypad 178, a CLOCK keypad 180, a KITCHEN TIMER keypad 182, and a SURFACE WARMER keypad 184.

By manipulating the appropriate input selector 134 in one of the control selector groups 136, 138, the appropriate feature or function is activated by an appliance controller (not shown in FIG. 4) and, for most of the features, an icon or indicator is displayed on display 132 to visually indicate selected appliance features and operating parameters, such as cooking time, and cooking temperature.

FIG. 5 is a block diagram of a control system 200 that may be used with range 10 (shown in FIGS. 1 and 2). Control system 200 includes a controller 201 that includes a microprocessor 202 that is coupled to input interface 130 and to display 132, and including a RAM memory 204 and a permanent memory 206, such as a flash memory (FLASH), a programmable read only memory (PROM), or an erasable programmable read only memory (EPROM) as known in the art. The controller memory is used to store calibration constants, oven operating parameters, cooking routine, and recipe information that may be used to control the oven heating elements and execute user instructions.

Microprocessor 202 is operatively coupled to a plurality of electrical heating elements 208 (i.e., oven bake element, broil element, convection element, and cooktop surface heating units) for energization thereof through relays, triacs, 209 or other known mechanisms (not shown) for cycling electrical power to oven heating elements 208. One or more temperature sensors 210 sense operating conditions of oven heating elements 208 and are coupled to an analog to digital converter (A/D converter) 212 to provide a feedback control signal to microprocessor 202. It is contemplated also that gas heating elements may be employed for oven operation in alternative embodiments of the invention.

In the exemplary embodiment, gas lockout valve assembly 66 is coupled to gas heating elements such as burners 22, 24, 26, 28 (shown in FIG. 1) for regulating a gas supply thereto as described above. Valve assembly 66 is operatively coupled to microprocessor 202 and is responsive thereto. When the gas lockout feature is selected through user manipulation of I/O interface 130, microprocessor 202 transmits a signal to valve assembly 66 to either open or close valve assembly 66. In one embodiment, when an operator depresses CLEAN keypad 150 to initiate the self-clean mode, microprocessor 202 energizes at least one of motor 82 or solenoid 83 to reposition valve 80 such that valve assembly 66 is repositioned to a closed position. When the gas lockout feature is deselected through user manipulation of I/O interface 130, microprocessor 202 transmits a signal to valve assembly 66. More specifically, microprocessor 202 energizes at least one of motor 82 and solenoid 83 to open valve 80 such that valve assembly 66 is repositioned to an open position.

In the exemplary embodiment, range 10 includes a plurality of switches 102, 104 that transmit a signal indicative of the operational position of gas lockout valve assembly 66. More specifically, gas lockout valve assembly 66 is activated, a portion of valve 80, such as for example cam 90 repositions at least one of switches 102, 104 from an open state to a close state such that an electrical signal is transmitted to microprocessor 202 indicative of an opened or closed state of valve 80, and microprocessor 202 causes appropriate visual indicia via interface 130 and/or audible signals to alert a user of the gas lockout condition when the gas lockout feature is activated. By monitoring a state of switches 102, 104 fault conditions, such as motor failure or switch failure, can be detected and indicated to a user.

In operation, when there is a need for a self-clean of the gas range 10, the operator initiates the self-clean mode by depressing an icon on visual indicia via interface 130, and gas lockout valve assembly 66 will automatically shut off gas supply before the self-clean is initiated. More specifically, when an operator depresses CLEAN keypad 150 of input selectors 134, an instruction of a self-clean mode is input to control system 200, in an exemplary embodiment, to microprocessor 202. After receiving the instruction of the self-clean mode, microprocessor 202 transmits a signal of a self-clean mode to gas lockout valve assembly 66. Gas lockout valve assembly 66, more specifically, valve 80 shuts off the gas supply in response to receiving the self-clean signal from microprocessor 202. When valve 80 is completely closed, switch 102 will be actuated, and provide a feedback of the self-clean signal to microprocessor 202. After receiving the feedback from switch 102 indicating the gas is in fact off, microprocessor 202 will provide instructions to initiate the self-clean mode. Thus surface burners 22, 24, 26, and 28 cannot be used during the self-clean process. After the self-clean process is completed, microprocessor 202 will prompt a user via display 132 to unlock the gas range 10 such that valve assembly 66 can be opened and allow the gas supply again.

The methods and apparatus described herein facilitate reducing a quantity of heat that is generated from an oven cavity during a self-clean mode of operation. More specifically, when the oven described herein is operated in a self-clean mode, the gas valve is closed such that the gas surface burners are not operable in the self-clean mode. Accordingly, the methods and apparatus described herein facilitate reducing a heat output of the oven such that during the self-clean mode, additional insulation is not used to insulate the oven cavity, thus lowering construction costs.

While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the claims.