Warmer drawer for a cooking range

Information

  • Patent Grant
  • 6191391
  • Patent Number
    6,191,391
  • Date Filed
    Wednesday, December 18, 1996
    28 years ago
  • Date Issued
    Tuesday, February 20, 2001
    23 years ago
Abstract
A warming drawer for a domestic range which is disposed within a heating chamber located relatively beneath the oven. The heating chamber is surrounded by a series of panels, and has a heating element disposed therein. The heating element is energized in accordance with a user-determined duty cycle such that temperature within the heating chamber is maintained between a predetermined minimum temperature and a predetermined maximum temperature. The range of temperatures between the predetermined minimum and predetermined maximum correspond to a range of desired food serving temperatures at the warmer drawer.
Description




BACKGROUND OF THE INVENTION




1. Field of the Invention




The present invention pertains to domestic cooking ranges and, more particularly, to domestic cooking ranges having a warming drawer adapted to receive and maintain cooked hot food at an above-ambient temperature.




2. Description of Related Art




Domestic cooking ranges traditionally include an open space relatively beneath the oven which slidably receives a storage drawer in which the user may store various articles, such as cooking pots and/or pans. As such, the conventional or prior art drawer is only useful for storage purposes, and could not be used to heat or warm food.




The space occupied by the storage drawer has also, in the past, been used as a broiling cavity which receives a broiling tray. A broiling element is located relatively above the broiling tray. The broiling element is operated at high temperatures as required to accomplish the broiling function.




The prior art references which include a broiling element do not control energization of the broiling element to only warm food contained on the broiling tray. Rather, the broiling element is typically operated exclusively at full power, as required for broiling. Due to the high-energy or high-heat output of the broiling element, maintaining food at an above-ambient temperature for warming purposes, but still low enough so that further cooking does not occur, is not possible.




Therefore, there exists a need in the art for a cooking appliance which provides a warmer drawer in which heating or warming of food is permitted. There also exists a need in the art for a warming device wherein the temperature of the food within the device is controlled such that further cooking of the food, which may degrade the food quality, does not occur.




SUMMARY OF THE INVENTION




In accordance with the present invention, a cooking appliance includes a cabinet, an oven wrapper disposed within the cabinet, a warmer liner, a heating element, and a warmer drawer which is slidably secured to the cooking appliance. The oven wrapper has a generally inverted U-shape including a pair of lateral side walls. The oven liner includes a liner top wall and a liner bottom wall disposed generally between the wrapper lateral side walls. The heating element is secured to the liner bottom wall relatively beneath said warmer drawer.




In further accordance with present invention, a method for controlling a warmer drawer heating element to maintain a temperature within a heating chamber between a predetermined maximum and a predetermined minimum, wherein said warmer drawer heating element is disposed within said heating chamber, include the steps of moving a heater control switch from an off position to a user-selected position, said user selected position corresponding to a duty cycle of heater element operation; energizing said heater element at full power; sensing the temperature within said heating chamber; terminating full power energization of said heater element at said predetermined maximum temperature; and energizing said heater element at said predetermined duty cycle.




In further accordance with the present invention, a cooking appliance includes a cabinet, a lower heating chamber adapted to receive a food-receiving member, a heating element disposed within said heating chamber and relatively beneath the food-receiving member, and means for controlling energization of the heating element such that a temperature within said heating chamber is maintained between a predetermined minimum and a predetermined maximum. The range of temperatures between the predetermined maximum and predetermined minimum correspond to a range of desired food serving temperatures within the warmer drawer.











BRIEF DESCRIPTION OF THE DRAWINGS




Features of the present invention will be apparent with reference to the following description and drawings, wherein:





FIG. 1

is a perspective view of a cooking range with a food warmer drawer in a fully extended position;





FIG. 2

is a rear perspective view of a food warmer drawer according to the present invention;





FIG. 3

is a front elevational view of a lower portion of the cooking range shown in

FIG. 1

, with the food warmer drawer removed therefrom;





FIG. 4



a,




4




b,


and


4




c


are, respectively, a front elevational view, a top plan view, and a side elevational view of a front heat shield panel or grate according to the present invention;





FIG. 4



d


is a cross sectional view of the front heat shield as seen along line


4




d


-


4




d


of

FIG. 4



a;







FIG. 5



a,




5




b,


and


5




c


are, respectively, a front elevational view, a top plan view, and a side elevational view of a rear heat shield panel according to the present invention;





FIG. 6



a,




6




b,


and


6




c


are, respectively, a top plan view, a front elevational view, and a side elevational view of a lower heat shield panel according to the present invention;





FIG. 7



a,




7




b,


and


7




c


are, respectively, a bottom plan view, a front elevational view, and a side elevational view of an upper heat shield panel according to the present invention;





FIGS. 8



a,




8




b,


and


8




c


are, respectively, a front elevational view, a top plan view, and a side elevational view of a temperature sensor mounting bracket according to the present invention;





FIGS. 9



a,




9




b,


and


9




c


are, respectively, a front elevational view, a top plan view, and a side elevational view of a warmer drawer temperature sensor according to the present invention;





FIG. 10

is a side elevational view of a warmer drawer glide assembly according to the present invention;





FIG. 11

is an end elevational view of the warmer drawer glide assembly shown in FIG.


10


.





FIG. 12

is top plan view of a heating element according to the present invention;





FIG. 13

is a perspective view of a heating element mounting clip according to the present invention;





FIG. 14

is a front elevational view of an oven chassis wrapper according to the present invention; and,





FIG. 15

is a schematic diagram illustrating a control circuit for the warmer drawer heating element.











DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT




It should be noted that in the detailed description which follows, identical components have the same reference numeral, regardless of whether they are shown in different embodiments of the present invention. It should also be noted that, in order to clearly and concisely disclose the present invention, the drawings may not necessarily be to scale and certain features of the invention may be shown in somewhat schematic form.




With reference to

FIG. 1

, a household range


20


incorporating the present invention is illustrated. The range includes a cabinet to which an oven door


22


is secured so as to permit pivotal movement of the door about its bottom edge. The cabinet includes a top panel which includes surface heating elements (not shown). A control panel


24


extends upwardly from adjacent a rear portion of the top panel, and includes a plurality of control devices, such as dials, switches, buttons, and/or knobs.




The control devices provided by the control panel include a warmer drawer heater control switch


26


, and associated indicator light


28


. Preferably, the warmer drawer heater control switch


26


is rotatably mounted to the control panel, and is movable in a push-and-turn fashion to any user-selected position between an off position, and a high heat position. More preferably, the warmer drawer heater control switch


26


is an infinite switch wherein the duty cycle (ratio of heater on-time to heater on-time plus heater off-time) varies from zero, when the switch is set to the off position, to one when the switch


26


is set to the high position.




As will be described more fully hereafter, rotation of the warmer drawer heater control switch


26


between the various user-selected positions varies the duty cycle of a warmer drawer heating element


32


. It is believed that operation of infinite switches is well known to one skilled in the art and, therefore, will not be further discussed hereinafter.




With reference to

FIG. 2

, the warmer drawer


34


according to the present invention is illustrated. The warmer drawer preferably includes a pair of lateral side walls


36


, a rear wall


38


, a bottom wall


40


, and a front wall


42


which cooperate to define a receptacle adapted to receive food stuffs to be maintained at an acceptable above-ambient serving temperature.




The front wall


42


includes a front panel


44


from which a handle extends (FIG.


1


). Each of the lateral side walls


36


has a first portion


47


of a glide assembly


48


secured thereto, as will be described more fully hereafter.




The front wall and panel


42


,


44


extend or project laterally and vertically outboard and perpendicular to the lateral side walls


36


and bottom wall


40


of the drawer. An annular heat seal member or gasket


50


is attached to a rearward facing surface of the front wall


42


and surrounds the lateral side walls


36


and bottom wall


40


, as illustrated. When the drawer is in a retracted or closed position, the heat seal member


50


limits the escape of heat from within the warmer drawer


34


and heating chamber


54


, to be described hereafter. Preferably, the heat seal member is formed from material commonly used to seal the periphery of the oven door to the cabinet.




The heat seal member


50


does not prevent air from being drawn through slotted openings


56


in the grate


52


, as is desirable to supply supplementary combustion air to a lower burner of a gas range. As will be apparent to one skilled in the art, the front grate


52


may be modified and the usable heating chamber height increased accordingly for electric ranges, since supplementary combustion air is not required.




The walls of the warmer drawer


34


are preferably formed from steel, and have a porcelainized inner surface. A porcelain inner surface of the warmer drawer is preferable over a painted surface for a number of reasons. These reasons include heat tolerance, resistance to scratches and wear, ease of cleaning, and aesthetic continuity with other surfaces of the oven. The warmer drawer


34


may receive one or more racks (not shown) which support foodstuffs in a spaced relationship to the bottom wall


40


.




With reference to

FIG. 3

, the range cabinet provides an open space between the bottom of the cooking oven (not shown) and the floor. The open space is defined, in part, by lateral sidewalls


60


of an oven chassis wrapper


58


, which is illustrated in FIG.


14


. The oven chassis wrapper


58


is generally of an inverted U-shape, and defines the lateral and top walls of the cooking oven. A bottom oven wall (not shown) and rear oven wall (not shown) are mechanically attached, such as by welding, to the oven chassis wrapper to define the cooking oven.




A base portion of the oven chassis wrapper lateral walls


60


defines the lateral extent of the open space. A warmer drawer liner assembly is attached to the cabinet in the open space and cooperates with the lateral walls


60


to define the heating chamber which receives the warmer drawer


34


.




The warmer drawer liner assembly includes, in addition to the front panel or grate


52


, an upper panel


62


, a lower panel


64


, and a rear panel


66


.




The front panel or grate


52


is secured to the upper panel


62


, as will be described more fully hereafter and, with reference to

FIGS. 4



a


-


4




d,


includes a front wall


68


, a bottom wall


70


, and a pair of upper tabs


72


. The front wall


68


has the slotted openings


56


formed therein, as discussed hereinbefore. The bottom wall


70


and the upper tabs


72


extend rearwardly from the front wall


68


.




Each of the upper tabs


72


includes an opening


74


through which a mounting screw is inserted to secure the front panel


52


to a front chassis wall of the range


20


(FIG.


1


). The lower wall


70


has a proximal portion


76


adjacent the front wall and a distal portion


78


spaced from the front wall. The proximal portion


76


includes a pair of openings


80


underlying the upper tabs


72


through which access to the tabs may be gained for insertion/removal of the mounting screws.




The distal portion


78


has a series of short slots


82


formed therein which separates the distal portion of the lower wall into an alternating series of first tabs


84


and second tabs


86


. The first tabs


84


are generally co-planar with the proximal portion


76


of the bottom wall, while the second tabs


86


are bent upwardly at an angle to the common plane of the first tabs


84


and the proximal portion


76


, as illustrated.




The second or angled tabs


86


have openings


88


formed therein through which screws are inserted to secure the upper panel


62


to the front panel or grate


52


. As will be described more fully hereafter with reference to assembly of the front panel to the upper panel, the upper panel


62


is inserted relatively above the first tabs


84


and relatively below the second tabs


86


, and screws are inserted through the openings in the second tabs


86


and through the upper panel


62


to secure the upper panel


62


to the front panel


52


.




The upper panel


62


is secured to the front panel or grate


52


, as described hereinbefore, and to the lateral walls


60


of the oven chassis wrapper


58


. The upper panel is located rearwardly relative to the front panel or grate, and defines an upper extent of the heating chamber.




With reference to

FIGS. 7



a


-


7




c,


the upper panel


62


includes a generally planar plate


90


from which a rearward flange


92


and a pair of lateral flanges


94


are downwardly bent. The lateral flanges


94


include openings through which screws are inserted to secure the upper panel to the lateral walls


60


of the oven chassis wrapper


58


. The front edge of the upper panel is slidably inserted between the first and second tabs


84


,


86


of the front panel, and includes openings through which screws are inserted to secure the upper panel


62


to the front panel


52


, as discussed hereinbefore.




The lower panel


64


is secured to the rear panel


66


and to lateral walls


60


of the oven chassis wrapper, and defines a lower extent of the heating chamber


54


. With reference to

FIGS. 6



a


-


6




c,


the lower panel


64


includes a plate member


96


from which a rear flange


98


and a pair of lateral flanges


100


extend.




The rear flange


98


is bent generally perpendicular to the plate member


96


, and is secured to the rear panel


66


by means of a screw. The lateral flanges


100


are generally Z-shaped in cross section, and define openings through which screws extend to secure the lateral flanges to the lateral walls


60


of the oven chassis wrapper


58


.




The plate member


96


also provides a pair of mounting tabs


102


and a series of dimpled mounting openings


104


. The mounting tabs


102


are bent upwardly from the plate member


96


and define pockets for receipt of a temperature sensing and circuit enabling/disabling assembly, hereinafter referred to as the temperature sensing assembly. The mounting tabs


102


slidably, yet resiliently, receive the temperature sensing assembly thereunder, as will be described hereafter. The dimpled mounting openings


104


are provided to facilitate securing heating element mounting clips


106


(

FIG. 13

) to the lower panel


64


, as will be described hereafter.




The rear panel


66


is secured to the lower panel


64


and to the lateral walls


60


of the oven chassis wrapper


58


, and extends between rearward edges of the upper and lower panels


62


,


64


, and between the lateral walls of the oven chassis wrapper. The rear panel defines a rearward extent of the heating chamber


54


.




With reference to

FIGS. 5



a


-


5




c,


the rear panel


66


includes a plate


108


from which a lower flange


110


and a pair of lateral flanges


112


extend. The lateral flanges


112


extend generally rearwardly of the plate


108


, and include openings to assist in mechanical securement of the lateral flanges to the lateral walls


60


of the oven chassis wrapper. The lower flange


110


has a generally inverted-L shape, and is adapted to extend out over, and in front of the rear flange


98


of the lower panel


64


. A vertical face


114


of the lower flange


110


includes an opening through which a mounting screw extends to secure the lower flange


110


to the rear flange


98


.




As such, the panels


52


,


62


,


64


,


66


cooperate with the oven chassis wrapper


58


to define the heating chamber, which is closed at its lateral sides, rear side, upper side, and lower side, and open at the front. The warmer drawer


34


is slidably inserted into the heating chamber


54


, and slidably removed from the heating chamber, by means of the glide assembly


48


, to be described further hereafter.




It should be noted that the illustrated warmer drawer liner assembly is intended for an electric range. On gas ranges, the rear panel is not used, and the rearward extent of the heating chamber is defined by a vertical wall which has control devices for the lower gas burner assembly mounted thereto. The vertical wall and control devices are conventional and, therefore, are not specifically illustrated.




Each of the lateral walls


60


of the oven chassis wrapper have a second portion


46


of the drawer glide assembly


48


secured thereto. The first and second portions


47


,


46


of the glide assembly


48


cooperate with one another to permit the drawer


34


to be slidably inserted into the heating chamber, and slidably removed from the heating chamber. Also, the first and second glide portions


47


,


46


may be disengaged from one another to permit the warmer drawer


34


to be completely disconnected and removed from the range


20


, as would be desirable for cleaning and/or maintenance purposes. It is understood that numerous glide assemblies are known in the art, and various other glide assemblies may be substituted for the illustrated glide assembly


48


without departing from the scope and spirit of the present invention.




The heating element


32


(

FIG. 12

) and temperature sensing assembly (

FIG. 3

) are disposed within the heating chamber


54


and secured to the lower panel


64


. The heating element


32


preferably comprises a tubular, electrical resistance-type heating element which is fastened to the lower panel


64


via the mounting clips


106


(

FIG. 13

) and a mounting bracket


118


(

FIG. 8



a


-


8




c


). The mounting clips


106


are attached to the mounting openings


104


in the lower panel and clamp the heating element


32


to the lower panel


64


. Naturally, more or less than the illustrated four mounting clips


106


may be used to secure the heating element


32


to the lower panel


64


, if desired.




A mounting plate


116


of the heating element


32


is secured to the mounting bracket


118


of the temperature sensing assembly, as will be described hereafter. The heating element


32


is electrically connected to a temperature sensor


30


, and is powered in accordance with the user-selected setting of the control switch


26


and as-needed to maintain the temperature within the heating chamber


54


, as sensed by the temperature sensor


30


, within a predetermined desired range of operating temperatures, as will be described hereinafter with reference to the control circuit illustrated in FIG.


15


.




The temperature sensing assembly includes the temperature sensor


30


and the mounting bracket


118


. The temperature sensor


30


is secured to the mounting bracket


118


in an elevated position, as illustrated in

FIG. 3

, and is operable to sense the temperature within the heating chamber


54


.




With reference to

FIGS. 8



a


-


8




c,


the mounting bracket


118


includes a body member


120


from which a base flange


122


extends rearwardly. The base flange is slidably received under the mounting tabs


102


and mechanically attached, preferably by a screw, to the lower panel


64


. The body member


120


defines an elongated opening


123


which receives the temperature sensor


30


, and includes a plurality of openings through which fasteners extend to secure the temperature sensor


30


and the heating element mounting plate


116


to the mounting bracket


118


.




The temperature sensor


30


has a forwardly projecting sensor portion


126


, a mounting flange


128


, and a rearwardly extending connector portion


130


. The mounting flange


128


includes a pair of lateral openings through which fasteners extend to secure the temperature sensor


30


to the mounting bracket


118


. The temperature sensor


30


is inserted through the elongated opening


123


in the mounting bracket body, such that the sensor portion


126


faces toward the warmer drawer


34


and the open front of the heating chamber


54


and the connector portion


130


faces toward the rear panel


66


. The connecting portion


130


is electrically connected, via suitable conductors, to the control switch


26


and the heating element


32


.




The location of the sensor


30


and mounting bracket


118


gives the control circuit its ambient compensation characteristics. For example, and as will be apparent from the description to follow, relatively more heat may have to be input into the heating chamber to reach the predetermined maximum temperature during low ambient conditions than during high ambient conditions. Putting more heat into the heating chamber during low ambient may help reduce cycling as the time required to reach the minimum temperature will be extended. Moreover, the temperature within the warmer drawer corresponding to the predetermined maximum heating chamber temperature may be relatively higher during low ambient conditions than during high ambient conditions. For high ambient conditions, less heat may be required to reach the predetermined maximum heating chamber temperature, and less heat is lost to atmosphere, so temperature within the heating chamber and the warmer drawer may be relatively more uniform and static.




The warmer drawer


34


of the present invention is located relatively above the heating element


32


and, therefore, the present invention takes advantage of the natural tendency of relatively hot air to rise. As such, the food stuffs contained within the drawer


34


are in a relatively hot portion of the heating chamber


54


. As mentioned briefly hereinbefore, it may be desirable to place one or more removable racks within the drawer


34


to space the foods being warmed away from the bottom wall


40


of the drawer. Spacing of the food from the bottom wall


40


permits warm air to flow beneath the food and facilitates more even heating thereof. Spacing of the food from the bottom wall


40


also prevents localized over-heating of the food at the interface with the bottom wall, since the bottom wall will be relatively hot, as compared to air within the heating chamber


54


, due to the proximity of the bottom wall to the heating element


32


.




With reference to

FIG. 15

, a control circuit


131


for the warmer drawer heating element


32


is illustrated. The circuit


131


generally includes an oven self-cleaning cycle lock-out switch


132


, the heater control switch


26


, the warmer indicator light


28


, the temperature sensor


30


, the warmer drawer heating element


32


, and a diode


134


. The heater control switch


26


provides first and second pairs of contacts


26




a,




26




b.


The first pair of contacts


26




a


are closed whenever the switch


26


is turned on. The second pair of contacts open and close when the switch


26


is turned on, the frequency of opening and closing depending upon the angular position of the switch


26


to vary or adjust the duty cycle of heater operation. For example, when the heater control switch


26


is turned to “high”, the second pair of contacts


26




b


are mechanically locked in a closed position whereas, when the switch


26


is turned to the “low” position, the second pair of contacts


26




b


will be closed only a portion of the time (e.g., 20%) and will be open the rest of the time. It is considered that the above-described operation of the switch


26


is well known in the infinite switch art.




The lock-out switch


132


opens and thereby de-activates or renders inoperable the warmer drawer heating element


32


, and the heater control switch


26


, when the oven is operated in a self-cleaning mode and, therefore, prevents energization of the heating element


32


during a self-cleaning cycle.




The first pair of heater control switch contacts


26




a


are connected in series with the lock-out switch


132


. The warmer indicator light


28


is connected in parallel with the warmer heating element


32


and a heating element energization control circuit


136


and, therefore, is illuminated whenever the heating element


32


is powered to provide visual indication to the user that the warmer heating element


32


is operating.




The temperature sensor


30


provides a thermally-actuated switch


30




a


which is normally-closed. The warmer element energization circuit


136


includes the diode


134


and the second pair of heater control switch contacts


26




b


in parallel with the temperature sensor switch


30




a,


as illustrated. Therefore, when the heater control switch


26


is turned from “off” to any position, the series combination of the second pair of heater control switch contacts


26




b


and the diode


134


is shorted by the parallel branch due to the normally-closed temperature sensor switch


30




a.






The heating element


32


is therefore in series with the temperature sensor switch


30




a,


and full power is applied to the heating element


32


. At this point, no current flows through branch of the energization circuit


136


containing the diode


134


and the second pair of heater control switch contacts


36




b.


This period of operation is referred to herein as the preheating cycle during which the heating element


32


is operated at full power to more quickly bring the warmer drawer


34


up to the maximum operating or peak preheat temperature. When the temperature within the heating chamber


54


reaches the predetermined maximum desired temperature or peak preheat temperature, the temperature sensor switch


30




a


opens and control of the heating element energization is given over to the heater control switch


26


. The time required to reach the predetermined maximum temperature depends upon a number of factors, including the size, temperature, and type of food being warmed, and the ambient temperature.




The heating chamber temperature corresponds to the warmer drawer temperature (i.e., food temperature), so that sensing of the heating chamber temperature is an accurate guide to the warmer drawer temperature and, as will be apparent from the following description, the sensed heating chamber temperature is used to control energization of the heating element


32


to maintain the warmer drawer temperature within a range of desired food serving temperatures.




Due to the diode


134


, only half-wave rectified current flows through the heating element


32


which, therefore, is limited to half maximum power if the warmer switch is set to “high”. As noted hereinbefore, the duty cycle of the heating element operation is controlled by the angular position of the heater control switch


26


which, in turn, corresponds to the rate or frequency of opening/closing of the second pair of heater control switch contacts


26




b.






The duty cycle controls the amount of power dissipated in the heater element


32


which, in turn, affects the amount of heat energy added to the warmer drawer heating chamber


54


and, hence, the warmer drawer


34


. The rate at which the heating chamber temperature falls (from the maximum temperature at the end of the preheat cycle) is affected by the food load within the warmer drawer, the ambient temperature, and the user-selected duty cycle of the warmer drawer heating element


32


(i.e., the angular position of the switch


26


).




For example, at a given ambient temperature, if a relatively large, cool item of food is placed in the warmer drawer


34


and the warmer switch


26


is set to the “low” position (which corresponds to a small duty cycle, e.g., 0.20), the temperature within the heating chamber


54


and the warmer drawer


34


, following the preheat cycle, will fall faster than if a similarly sized but hotter item of food is placed in the warmer drawer and the warmer switch


26


is set to high (i.e., full one-half power, switch duty cycle equals 1.0). Similarly, if a small, hot food item is placed in the warmer drawer


34


in a low ambient environment and the warmer switch


26


is set to “medium”, the temperature within the heating chamber


54


and the warmer drawer will fall faster than if an item of similar size and temperature is placed in the warmer drawer in a high ambient environment and the warmer switch is set to the “medium” position.




If the heating chamber temperature drops below a predetermined minimum desired temperature (which corresponds to a minimum desired serving temperature within the warmer drawer), the temperature sensor contacts close, shorting the branch of the energization circuit


136


containing the diode


134


and the second pair of heater control switch contacts


26




b,


and full power is again applied to the heating element


32


until the heating chamber temperature exceeds the maximum desired temperature (corresponding to the maximum desired serving temperature within the warmer drawer), at which point the temperature sensor contacts open and control is returned to the heater control switch


26


at the user-selected duty cycle. Accordingly, the warmer drawer temperature is maintained between maximum and minimum desired serving temperatures.




As should be apparent from the foregoing, control over energization of the heating element


32


alternates between full power when the temperature sensor contacts close (preheat cycle and low heating chamber/warmer drawer temperature) and the user-selected duty cycle. As noted hereinbefore, the heat input into the heating chamber to reach the maximum desired heating chamber temperature will vary depending at least upon ambient temperature. Similarly, the rate at which the heating chamber temperature falls to the predetermined minimum desired heating chamber temperature will vary depending at least upon ambient temperature, food size and type, and user selected setting of the control switch


26


.




It is also noted that the maximum and minimum warmer drawer temperatures may vary in dependence upon ambient temperature. For example, the maximum warmer drawer temperature may be relatively higher in low ambient conditions than in high ambient conditions. Similarly, the minimum warmer drawer temperature may be relatively higher in low ambient conditions than in high ambient conditions. Since relatively more heat is lost to the environment in low ambient conditions than in high ambient conditions, the noted temperature compensation feature reduces cycling of the heater element between the user-selected duty cycle and full power cycle than would otherwise occur. The maximum and minimum warmer drawer temperatures fall within a range of desired food serving temperatures.




While the preferred embodiment of the present invention is shown and described herein, it is to be understood that the same is not so limited but shall cover and include any and all modifications thereof which fall within the purview of the invention.



Claims
  • 1. A method for controlling an electrical warmer drawer heating element to maintain a temperature within a lower heating chamber, comprising steps of:providing a range for placement on a floor, providing a cabinet to said range, providing an oven wrapper disposed within said cabinet and at least partially defining an oven chamber, providing the lower heating chamber relatively beneath said oven chamber, providing a fixed panel defining a lower extent of the heating chamber, providing the electrical heating element within said heating chamber, adjacent to the panel, providing the warmer drawer slidably mounted in the lower heating chamber, above the heating element and the panel, providing a temperature sensor disposed within said heating chamber and operable to sense temperature within said heating chamber, and providing controlling means for controlling said heating element such that a temperature within said heating chamber is maintained between a predetermined minimum temperature and a predetermined maximum temperature corresponding to a range of desired food serving temperatures; moving a heater control switch from an off position to a user-selected position, said user selected position corresponding to a duty cycle of heater element operation; energizing said heater element at full power; sensing the temperature within said heating chamber using the temperature sensor; terminating full power energization of said heater element at said predetermined maximum temperature; energizing said heater element at said predetermined duty cycle.
  • 2. A method for controlling a warmer drawer heating element according to claim 1, comprising the further steps of:terminating energization of said heater element at said predetermined duty cycle at said predetermined minimum temperature; energizing said heater element at full power; terminating full power energization of said heater element at said predetermined maximum temperature; and resuming energization of said heater element at said predetermined duty cycle.
  • 3. A method for controlling a warmer drawer heating element according to claim 1, wherein said controlling means comprise the temperature sensor and an infinite switch.
  • 4. A method for controlling a warmer drawer heating element according to claim 3, wherein, during a preheating cycle, said temperature sensor provides full power to said heating element to bring the temperature of said heating chamber to said maximum temperature.
  • 5. A method for controlling a warmer drawer heating element according to claim 4, wherein, following said preheating cycle, power to said heating element is supplied in accordance with a user-selected duty cycle via said infinite switch.
CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Application No. 60/010,578, filed Jan. 25, 1996.

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Provisional Applications (1)
Number Date Country
60/010578 Jan 1996 US