Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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METHODS AND APPARATUS FOR A GAS RANGE
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.
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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, transfernng 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
Figure 1 illustrates an exemplary free standing gas range.
Figure 2 is a side elevational view of the range shown in Figure 1
partly broken away.
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Figure 3 is a cross sectional schematic view of an exemplary gas
lockout valve assembly for the range shown in Figures 1 and 2.
Figure 4 is a plan view of a control panel interface for the range shown
in Figures 1 and 2.
Figure 5 is a schematic block diagram of a control system for the range
shown in Figures 1 and 2.
DETAILED DESCRIPTION OF THE INVENTION
Figure 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 suxface 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 Figure 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
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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.
Figure 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.
Figure 3 is a cross sectional schematic view of an exemplary
embodiment of a gas lockout valve assembly 66 including a valve 80 adapted for
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connection to a gas line such as gas line 70 (shown in Figure 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 Figure 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
Figure 2) and therefore to associated surface burner elements 22, 24, 26, and
28. In
the exemplary embodiment, valve 80 is a 1/2 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 Figure 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.
Figure 4 illustrates an exemplary input interface panel 130 that may be
used with range 10 (shown in Figures 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.
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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 (n) slew
keypad 156 and a temperature down (v) slew keypad 158. Group 138 includes an
hour up (n) slew keypad 160 and an hour down (v) slew keypad 162, a minute up
(n)
slew keypad 164 and a minute down (v) 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 Figure 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.
Figure 5 is a block diagram of a control system 200 that may be used
with range 10 (shown in Figures 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
(AJD
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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
Figure 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 1/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.
1n 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
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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.
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