(12) United States Patent
`(10) Patent N0.:
`US 6,274,847 B1
`
`Hlava et al.
`(45) Date of Patent:
`Aug. 14, 2001
`
`USOO6274847B1
`
`(54) MULTI-PURPOSE COOKING APPARATUS
`
`5,809,870 *
`
`9/1998 Baillieul ............................... 219/441
`
`(75)
`
`Inventors: Lorens G. Hlava; Mary Barrow, both
`of Clinton, MO (US)
`
`('73) Assignee: The Holmes Group, Inc., Milford, MA
`(US)
`
`( * ) Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 0 days.
`
`(21) Appl. No.: 09/566,347
`
`(22)
`
`Filed:
`
`May 8, 2000
`
`Int. Cl.7 ............................... A47J 36/26; H01H 3/16
`(51)
`52 US. CL .......................... 219 433~ 219 432 219 435~
`(
`)
`/
`,
`/
`,
`/
`,
`219/518; 99/340
`(58) Field of Search ..................................... 219/432, 433,
`219/429, 435, 441, 518; 99/340
`
`(56)
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`3 134 007 e
`5/1964 Niblo ................................... 219/518
`4,164,644 "
`8/1979 Remsnyder et al.
`219/433
`
`4,307,287 * 12/1981 Weiss ................................... 219/432
`
`FOREIGN PATENT DOCUMENTS
`133906 *
`3/1985 (DE) .
`3430878 *
`3/1986 (DE) .
`2651666 *
`3/1991 (FR) .
`2222025 *
`2/1990 (GB) .
`9605761 *
`2/1996 (W0) .
`
`* cited b V examiner
`y
`Primary Examiner—Joseph Pelharn
`(74) Attorney, Agent, or Firm—Hoffmann & Baron, LLP;
`Francis E. Marino
`
`(57)
`
`ABSTRACT
`
`A cooking apparatus including a housing having an interior
`which contains a heatin device. Asensor is
`rovided that is
`g
`9
`operatively connected to the heating device. The sensor
`having an actuated position, wherein the sensor affects a heat
`output generated by the heating device. A first and second
`cooking insert for containing the food to be cooked each
`being separately positionable Within the housing interior.
`The first cooking insert actuating the sensor when positioned
`in the housing interior, and the second cooking insert not
`“mating the sensor When POSitiOHedinthe hOUSing interim
`
`27 Claims, 10 Drawing Sheets
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`Euro-Pro v. Acorne
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`Euro-Pro Exhibit 1003
`Euro-Pro Exhibit 1003
`Euro-Pro v. Acorne
`Page 1 of 17
`IPR2014-00182
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`US. Patent
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`FIG. 1B
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`FIG. 4
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`FIG. 6
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`FIG. 7
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`FIG. 8
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`FIG. 9
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`US 6,274,847 B1
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`1
`MULTI-PURPOSE COOKING APPARATUS
`
`FIELD OF INVENTION
`
`The present invention relates to a cooking apparatus and
`specifically to a multi—purpose cooking apparatus which is
`capable of performing various types of cooking operations,
`including slow cooking and roasting.
`BACKGROUND OF THE INVENTION
`
`Roasters and slow cookers are two types of cooking
`devices well known in the art. Roasters typically include a
`covered chamber lined by a metal pan for receiving the food
`to be cooked. The temperature controls permit a wide range
`of cooking temperatures that may be set to accommodate a
`particular recipe. Roasters typically permit temperatures as
`high as 500° F. which is similar to that found in a typical
`kitchen oven. Roasters operate similar to a standard electric
`oven wherein the food is placed therein and cooked for a
`relatively short period of time, i.e., half an hour to two or
`three hours. Roasters include one or more heating elements
`that are capable of producing the high temperature required
`for roasting. Roasters typically include metal pan which
`hold the food. The metal pan fairly quickly and evenly
`distributes the heat
`thereby preventing the formation of
`localized hot spots.
`Another type of cooking device well known in the art is
`a slow cooker. An example of such a device is marketed by
`the Assignee of this application under the trademark Crock-
`pot®. Slow cookers typically include a stoneware or ceramic
`vessel for holding the food. The stoneware is typically
`removably insertable in a housing that contains heating
`elements for supplying heat to the stoneware and food. Slow
`cookers typically have a selector switch having a “high”,
`“low” and “off” setting for varying the heat setting thereby
`affecting the cooking time.
`The maximum power generated by slow cookers is sig-
`nificantly less then that for roasters since slow cookers rely
`on a slow even rate of cooking. Cooking time in slow
`cookers range from four to several hours. The low tempera-
`ture cooking permits users of the device to start a meal
`cooking in the morning and have it ready and properly
`cooked in time for dinner. Due to the slow cooking nature of
`the device,
`the contents of the stoneware need not be
`constantly monitored in order to prevent burning such as
`with a roaster. In addition, the relatively low power and even
`distribution of heat of the slow cooker prevents any particu-
`lar hot spot on the stoneware, which could lead to thermal
`stresses and cracking. The stoneware acts as an insulator
`which is beneficial for slow cooking but is susceptible to
`cracking if the heat output is too high and the temperature
`rises too quickly.
`Roasters and slow cookers provide two very different
`ways to prepare food. The roaster with its high temperature
`range permits cooking meals within a relatively short time
`while the slow cooker allows simmering type cooking over
`several hours. Accordingly, it is desirable to have both a
`roaster and slow cooker in order to accommodate a wide
`
`10
`
`15
`
`40
`
`45
`
`variety of cooking situations. However, both of these units
`are relatively large counter top appliances and therefore
`either take up a large amount of kitchen counter top space or
`storage space in the kitchen. This particular problem is
`especially acute in small kitchens where the counter top
`space and storage is at a premium.
`However, roasters of the prior art are unsuitable for safely
`slow cooking food in stoneware due to the high power
`output of such devices and the temperature sensitivity of
`
`60
`
`65
`
`2
`stoneware. The control circuit of roasters typically includes
`a thermostat which turns on a heating element until a desired
`temperature level is reached and then the element is shut off.
`The cycling on and off of the heating element is used to
`control the temperature. Therefore, even on relatively low
`temperature settings a cooking vessel is subjected to a full
`power high heat condition that could damage stoneware.
`Accordingly, roasters almost exclusively include metallic
`inserts that are able to quickly distribute the heat and permit
`uniform cooldng of the contents. In contrast, stoneware,
`which is essentially an insulator, does not dissipate heat well
`and is subject to cracking when exposed to fast temperature
`rises and high heat lcvcls.
`Accordingly, it would be desirable to provide a multipur-
`pose cooking apparatus that selectively provides the cooking
`characteristics of both a roaster and a slow cooker.
`
`SUMMARY OF THE INVENTION
`
`It is an advantage of the present invention to provide a
`cooking apparatus which is capable of functioning as a
`roaster and a slow cooker.
`
`the present invention to
`It is a further advantage that
`provide a cooking apparatus having a heating device which
`can be selectively controlled to deliver the appropriate heat
`depending on the cooking function which is desired.
`It is yet a further advantage of the present invention to
`provide a cooking apparatus having a switch that is actuat-
`able by a food holding component of the cooking device
`such that when it is inserted therein,
`the proper heating
`profile is developed.
`These and other advantages of the present invention may
`be obtained by providing a cooking apparatus including a
`housing having an interior which contains a heating device.
`A sensor is provided that is operatively connected to the
`heating device. The sensor having an actuated position,
`wherein the sensor affects a heat output generated by the
`heating device. A first and second cooking insert for con-
`taining the food to be cooked are each separately position-
`able within the housing interior. The first cooking insert
`actuating the sensor when positioned in the housing interior,
`and the second cooking insert not actuating the sensor when
`positioned in said interior.
`The present invention may also provide a cooking appa-
`ratus including a housing having a base and a wall extending
`upwardly therefrom forming a housing interior. A heating
`device is positioned in the housing interior. A first and
`second cooking insert for holding food to be cooked is
`provided and each of the first and second cooking inserts is
`separately positionable within the housing interior. A sensor
`is operatively connected to the heating device. The sensor is
`able to detect the presence of one of the first and second
`inserts when positioned within the housing. The sensor
`affects the heat output of the heating device upon the
`detection of the one of the first and second inserts.
`
`As more specifically described by way of the preferred
`embodiment herein, the inserts made of differing configu-
`rations with one of the first and second inserts actuating the
`sensor and the other insert not actuating the sensor. To
`achieve this, the housing side wall ends in an upper rim and
`the first
`insert has an outwardly extending first
`flange
`supported by the upper rim when the first insert is positioned
`within the housing interior. The first insert has a first body
`portion extending below the first flangc that actuatcs the
`sensor when the first flange rests upon the rim. The second
`insert has a second flange extending outwardly therefrom.
`The second flange is supported by the housing upper rim
`
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`US 6,274,847 B1
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`3
`is positioned Within the housing
`when the second insert
`interior. The second insert does not actuate the sensor when
`positioned within the insert. The sensor includes a switch
`that is actuatable by one of the first and second inserts. The
`heating device includes a plurality of heating elements and
`the switch is operatively connected to one of the plurality of
`heating elements for interrupting power transmission
`thereto.
`
`In addition, thc first inscrt may includc a stoncwarc pot
`and the second insert may include a metallic pan. The sensor
`detects the presence of the first insert within the housing and
`limits the maximum power output of the heating device such
`that the cooking apparatus functions as a slow cooker.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`10
`
`15
`
`FIGS. 1A and 1B are an exploded perspective View of the
`multipurpose cooking apparatus of the present invention
`showing both a metallic and stoneware cooking insert.
`FIG. 2 is a top perspective View of the cooking apparatus .
`of the present invention.
`FIG. 3 is a front elevational View of the present invention
`having the stoneware insert placed therein with portion of
`the cooking apparatus cut away for clarity.
`FIG. 4 is a side elevational view showing a partial cut
`away of the cooking apparatus of FIG. 3.
`FIG. 5 is a front elevational View of the present invention
`having the metallic cooking insert placed therein with a
`portion of the housing cut away for clarity.
`FIG. 6 is a side elevational View with a portion of the
`housing cut away for clarity of the cooking apparatus of
`FIG. 5.
`FIG. 7 is a schematic View of the control circuit of the
`present invention.
`FIG. 8 is a schematic View of an alternative embodiment
`
`’
`
`of the control circuit of the present invention.
`FIG. 9 is a schematic View of another alternative embodi-
`ment of the control circuit of the present invention.
`
`DETAILED DESCRIPTION OF THE
`PREFERRED EMBODIMENT
`
`The present invention provides a multi-functional cook-
`ing apparatus that is capable of safely and efficiently oper-
`ating as both a roaster and a slow cooker. The invention is
`preferably directed to a counter top cooking apparatus
`having the ability to combine the functions of a roaster and
`a slow cooker, thereby eliminating the need for two separate
`appliances saving valuable kitchen counter top and storage
`space.
`
`The preferred embodiment of the present invention is
`shown in FIGS. lA—B and 2. Generally, the cooking appa-
`ratus 10 includes a housing assembly 12, a metallic cooking
`inscrt 14 and a stoncwarc or ccramic cooking inscrt 16 that
`are used to hold the food. Stoneware insert 16 is essentially
`a pot used for slow cooking and is preferably formed of
`ceramic material of the type used to form standard slow
`cooker inserts. Metallic insert 14 is essentially a pan used for
`roasting. Cooking inserts 14 and 16 are selectively remov-
`ably insertable within housing assembly 12 depending on if
`the roaster or slow cooker function is desired. Metallic insert
`14 may include a removable roasting rack 17 for supporting
`the food. In addition, a lid 18 is further provided to cover the
`contents of the cooking insert.
`Referring additionally to FIGS. 3 and 5, housing assembly
`12 preferably includes a base 20 which is parametrically
`
`40
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`45
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`60
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`65
`
`4
`bounded by an upwardly extending side wall 22 ending in a
`rim 24. Base 20 and side wall 22 define a housing interior
`26. Side wall 22 may include a pair of outwardly extending
`handles 27 in order to submit an individual to carry the
`cooking apparatus 10. Housing interior preferably includes
`an inner surface defined by a liner 28 that is preferably
`formed of a heat conductive material such as aluminum or
`steel. Liner 28 extends along the inner surface of side wall
`22 and base 20 and is configured to receive the metallic or
`stoneware inserts 14 and 16.
`
`In order to heat the food contents of the cooking insert, a
`heating device 30 is positioned about an outer surface of
`liner 28. Heating device 30 preferably includes a plurality of
`resistance type heating elements formed in a band wrapping
`around liner side wall 34. Heating elements when supplied
`with power transfer heat to liner 28 side wall, which through
`conduction carries the heat throughout the liner. The heated
`liner distributes the heat about the cooking insert that is
`positioned within the housing. In order to protect housing
`side wall 22 and base 20 from the heat, side wall insulation
`22a and bottom insulation 20a may be inserted in the
`housing. Insulation 22a and 20a may be of a fiberglass
`material of the type typically used in roasters.
`When a cooking insert is positioned within the housing,
`the side wall of the insert is spaced relatively close to heating
`device 30. If the heat output
`is not properly regulated,
`problems may occur when stoneware insert 16 is placed in
`housing interior 26. The stoneware insert
`is particularly
`susceptible to fast and high concentrations of heat since it
`does not quickly dissipate heat. This permits localized hot
`spots on the stoneware that could result in localized thermal
`stresses and cracking. The metallic insert due to its ability to
`quickly conduct heat away reduces any thermal stresses
`caused by localized heating and therefore is suitable for fast,
`high heat environments.
`is
`the appropriate heat output
`In order to ensure that
`developed for the different inserts,
`the present invention
`includes an insert discriminating sensor. Accordingly, the
`cooking apparatus of the present invention can determine
`which insert, stoneware 16 or metallic 14, is placed within
`housing 12 and adjust the maximum permitable heat output
`accordingly. The sensor is activated by placement of one of
`the inserts into the housing such that the proper heat output
`range for the desired cooking method can be employed. The
`proper heat level is maintained for a slow cooker that relies
`on low even heat for slowly cooking its contents over several
`hours. Therefore, when stoneware insert 16 is placed within
`housing 12, the maximum heat output permitted by heating
`device 30 is limited to prevent thermal shock and cracking
`of the stoneware. However, when metallic insert 14 is
`inserted in housing 12, and thereby designating the roaster
`function,
`the maximum heat output
`is permitted to be
`increased in order to achieve suitable roasting temperatures.
`In the preferred embodiment, sensor 36 detects the par-
`ticular configuration of inserts 14 and 16. That
`is,
`the
`stoneware insert 16 and the metallic insert 14 may be
`differently configured resulting in sensor 36 being actuated
`by one insert and not the other, Referring to FIGS. 5 and 6,
`metallic insert 14 is a pot-like structure having a bottom wall
`38 surrounded by a side wall 40 with an annular flange 42
`extending radially outward from an upper end of side wall
`40. Flange 42 is dimensioned to rest upon rim 24 of the
`housing side wall when insert 14 is placed within housing
`12. The distance between flange 42 and an insert bottom wall
`38 is such that metallic insert bottom wall 38 is spaced a
`certain distance d from the bottom wall 29 of liner 28.
`
`Referring to FIGS. 3 and 4, stoneware cooking insert 16
`is similarly configured to metallic insert 14 having a bottom
`
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`US 6,274,847 B1
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`5
`wall 44 surrounded by an upwardly extending side wall 46
`which ends in the outwardly extending annular flange 48.
`When insert 16 is placed within housing 12, flange 48 is
`supported by housing rim 24 and side wall 46 and bottom
`wall 44 extend into housing interior 26. Stoneware insert 16,
`however, preferably extends further into the housing interior
`26 than metallic insert 14.
`
`In order to distinguish between the two cooking inserts 14
`and 16, sensor 36 preferably includes a cut off switch that is
`positioned on liner bottom wall 29 and extends upwardly
`there through into housing interior 26. Sensor 36 is actuated
`by stoneware insert 16 as shown in FIG. 3, but not engaged
`by metallic insert shown in FIG. 5 due to insert 16 extending
`further into housing interior 26 than insert 14. Sensor 36
`may be a plunger type single pole single throw switch that
`is biased in the unactuated position. One particular switch
`that has been found to be suitable is marketed by Cutler
`IIammer, Inc. of Milwaukee Wis. as Type 7835 K11A.
`Sensor 36 may be covered by a resilient heat resistant cap 37
`that protects the components of sensor 36 from contamina-
`tion and the heat of the cooking insert. Sensor 36 works in
`conjunction with a control circuit 50 (FIG. 7) to regulate the
`heat output of heating device 30.
`It is also within the contemplation of the present invention
`that other types of sensors could be employed in order to
`distinguish between different cooking inserts. For example,
`a sensor that would be activated by a metal and not
`stoneware, such as a Hall-effect type sensor, could be used
`to detect the metallic insert 14. Therefore, an unactuated
`sensor would indicate a stoneware insert, and an actuated
`sensor would indicate a metallic insert was present in tie
`housing. With such a material detecting sensor, the configu-
`ration of the two cooking inserts 14 and 16 could 3e
`substantially the same.
`In addition, it is further within the contemplation of he
`present invention that the configuration of cooking inserts 14
`and 16 could be altered in a number of ways in order to have
`only one of the inserts activate the sensor. For examp e,
`switch 36 could be mounted on housing rim 42 and one of
`the inserts may include a notch (not shown) in its flange.
`Therefore,
`the insert with the notch would not activate
`switch 36 and the insert without a notch would actuate tie
`sensor.
`
`
`
`in order to
`With regard to the preferred embodiment,
`illustrate the effects of sensor 36 being moved into tie
`actuated position, control circuit 50 will now be described.
`Referring to FIG. 7, heating device 30 includes a plurality of
`heating elements each of varying wattage. In the preferred
`embodiment there are three such heating elements 30a, 30b
`and 306 having wattage values of 225 W, 50 W and 775 W,
`respectively. It is understood that these numbers are to be
`illustrative and not limiting as the actual number of elements
`and wattage values could be varied in order to obtain the
`desired heating profile. Heating elements 30a, and 30b are
`used in the slow cooking function, and the high-wattage
`heating element 306 is used only in the roaster function.
`Sensor 36 may be placed in control circuit 50 such that
`when sensor 36 is actuated by stoneware insert 16,
`the
`circuit
`to at
`least one of the three heating elements is
`electrically opened thereby preventing that element from
`being energized. Preferably, sensor 36 may open the circuit
`to the 775 W heating element 306. Therefore, when the
`stoneware insert 16 is placed within the hou sing 12, only the
`225 W and 50 W heating elements are capable of being
`energized. When sensor 36 is not actuated, such as when
`metallic insert 14 is placed within housing interior 26,
`heating element 306 may be energized.
`
`6
`In an alternative embodiment (not shown), metallic insert
`14 may be configured to activate a sensor and stoneware
`insert 16 may be configured not to actuate such a sensor
`when placed inside housing 12. In this embodiment the
`high-wattage heating element would only be energizable
`when the sensor is actuated by the metallic insert placed
`within the housing.
`The control circuit 50 further preferably includes a first
`controller in the form a user actuatable selector switch 52. A
`
`rotary-type switch of the type manufactured by Tower
`Manufacturing Corp. of Providence, RI. under the label
`3000 Series has been found to provide suitable results.
`Selector switch 52 may include four discrete positions off,
`low, high and roast. A first pilot light 54 may be provided to
`indicate that selector switch is the high or low positions. The
`high and low settings are selected when the slow cooker
`function is desired, and the roast position is selected when
`the roaster function is desired. Selector switch 52 is placed
`with the control circuit such that it receives current directly
`from a power source and supplies current to heating ele-
`ments 30a, 30b and 30C in the low, high and roast settings,
`respectively. Selector switch 52 is preferably located on
`housing side wall 22. Afirst dial 56 positioned on the outside
`of side wall 22 may be provided to permit a user to easily
`actuate selector switch 52.
`
`A second controller in the form of a thermostatic switch,
`or thermostat 58 is also preferably included. A thermostat
`marketed by Sammax International Ltd. of Providence, RI.
`as type AP-151 has been found to be suitable for this
`application. Thermostat 58 is of a type known in the art for
`temperature control and includes a temperature sensitive
`bimetallic component. In the preferred embodiment, sensor
`36 is placed in the control circuit between selector switch 52
`and thermostat 58. Thermostat 58 is also operatively con-
`nected to heating element 306. Therefore, when sensor 36 is
`actuated thermostat 58 and heating element 306 are
`decoupled from power source 66. In addition, when ther-
`mostat 58 electrically opens, such as when a set temperature
`is reached, current to heating element 306 will be termi—
`nated. Thermostat 58 further includes a second dial 64 that
`permits the user to set a certain temperature for roasting.
`When the temperature of the cooking apparatus reaches the
`preset level, the bi-metallic component will open the circuit
`thereby cutting power the 750 W element 306. Asecond pilot
`light 62 may be provided to indicate when the circuit is
`closed and current is flowing through thermostat 58. Ther-
`mostat 58 is preferably located on housing side wall 22 and
`is actuated by second dial 64 positioned on the outside of
`side wall 22 to be accessible by a user.
`It is also of the contemplation of the present invention to
`combine the selector switch and thermostat switch into one
`control device. In such a device, the control would start in
`an ofl position and would be moveable to a low setting and
`then high and then further rotatable to a particular roasting
`temperature.
`With reference to FIG. 7, the operation of the preferred
`control circuit 50 will now be described. The input of
`selector switch 52 is electrically coupled to an ac power
`source 66, and the output is electrically coupled to heating
`elements 30a, 30b, and 306. Heating element 306 is a high
`wattage element used only for the roasting function. If the
`slow cooker function is desired, stoneware insert 16 may be
`placed within housing 12 thereby actuating sensor 36. Upon
`actuation, sensor 36 electrically decouples thermostat 58 and
`high wattage heating element, 306, from power source 66.
`Therefore, heating element 306 cannot be energized with the
`stoneware insert in place. Selector switch 52 may then be set
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`US 6,274,847 B1
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`7
`low or high power setting. In the low
`to either the off,
`position, power to the 225 W heating element, 30a,
`is
`supplied. When the switch 52 is moved to the high setting
`both the 225 W and 50 W heating elements, 30a and 30b, are
`powered. The high and low power settings are suitable for
`use with stoneware insert 16 and provide the heating
`requirements for slow cooking function.
`When the roaster function is desired, a user would rotate
`selector switch 52 to the “roast” setting thereby electrically
`coupling selector switch 52 to sensor 36 and thermostat 58.
`Metallic insert 14 may then be placed within housing
`interior 26. Due to the configuration of insert 14, sensor 36
`remains in its unactuated position when metallic insert 14
`rests within housing 12. In the unactuated position, sensor
`36 which is normally closed completes the circuit from the
`power source to the 775 W element, 30c. This arrangement
`permits power to be supplied to heating element 306 thereby
`providing the maximum heat output of heating device 30.
`The user may then set thermostat 58 to the desired cooking
`temperature. When the set temperature is reached, thermo-
`stat 58 will open terminating power to heating element 30C.
`When the temperature drops beyond a certain level,
`the
`temperature will close providing power again to element
`30C. This cycling on and oif maintains the desired cooking
`temperature of the cooking apparatus 10 in a manner well
`known in the art.
`An alternative control circuit 50'
`
`is shown in FIG. 8.
`
`Control circuit 50' differs from that of the preferred embodi-
`ment primarily in the position within the circuit of insert
`detecting sensor. In this embodiment, sensor 36’ is prefer-
`ably a single throw double pole switch electrically coupled
`between heating elements 30a, 30b, and 30c and power
`source 66.
`
`Due to the configuration of insert 14, sensor 36' remains
`in its unactuated position when metallic insert 14 rests
`within housing 12. In the unactuated position, sensor 36'
`completes the circuit from the power source to the 775 W
`element, 306, and simultaneously opens a circuit disabling
`heating elements 30a and 30b. In an unactuated or first
`position, only element 30c is electrically connected to power
`source 66 and capable of being energized. In this state the
`roasting function can be performed. When sensor 36' is
`actuated such as by stoneware insert 16, element 30c is
`decoupled from power source 66 and elements 30a and 30b
`are coupled thereto. In this state the slow cooker function
`can be performed.
`Referring to FIG. 9, another alternative control circuit 50"
`may be employed. In this embodiment, heating device 30'
`includes three heating coils 30a', 30b‘ and 306' having a
`wattage of 225 W, 50 W and 500 W, respectively. A selector
`switch 52' having an off, high and low setting is also
`provided. Selector switch 52' is placed with control circuit
`50" such that it receives current passing through thermostat
`58 and selectively supplies current to heating elements 30a'
`and 30b‘. Insert detecting sensor 36 includes a normally
`closed single pole single throw switch that selectively con-
`trols a circuit path to heating element 306'. The user adjust-
`able thermostat 58, of a type described with reference to the
`preferred embodiment,
`is placed in the circuit between
`power source 66 and heating elements such that when it
`electrically opens, current to heating elements 30a' and 30b',
`and 306‘, will be terminated.
`When power is supplied to control circuit 50" of cooking
`apparatus 10, current may flow through normally closed
`thermostat 58 to the input of selector switch 52'. When
`stoneware insert 16 is present in housing 12 thereby actu-
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`ating sensor 36, a circuit to the 500 W heating element is
`electrically opened preventing this high wattage heating
`element form being energized. Selector switch 52' may then
`be set to either the of, low or high power setting. In the low
`position, power to the 225 W heating element is supplied.
`When selector switch 52' is moved to the high setting both
`the 225 W and 50 W heating elements are powered. These
`power settings are suitable for use with stoneware insert 16
`and provide the heating requirements for slow cooking
`function. In addition, the minimum temperature of thermo-
`stat 58,
`i.e.,
`the minimum temperature at which the
`bi-metallic thermostat element will open, is not attained
`even when both the 225 W and 50 W heating elements 30a',
`and 30b‘ are powered. Therefore, the circuit from the power
`source to selector switch 52‘ is always uninterrupted when
`cooking apparatus 10 is used as a slow cooker.
`When the roaster function is desired, metal insert 14 may
`be placed within housing interior 26. Due to the configura-
`tion of insert 14, sensor 36 remains in its unactuated,
`normally closed position when insert 14 sits within housing
`12. Therefore, a circuit from the power source to the 500 W
`element 306' is established. A user would rotate selector
`
`switch 52' to the high setting and set thermostat 58 to the
`desired cooking temperature. Therefore, power will be sup-
`plied to all three heating elements providing the maximum
`heat output of heating device 30‘. When the set temperature
`is reached, thermostat 58 will open terminating power to all
`heating elements 3041', 30b' and 306'. When the temperature
`drops beyond a certain level,
`the temperature will close
`providing again to all the elements. This cycling on and off
`maintains the desired cooking temperature of the cooking
`apparatus 10.
`As will be appreciated by those skilled in the art, a wide
`variety of circuit and circuit components could be employed
`in order to ensure the benefits of the preferred embodiment,
`i.e., limiting the heat generated when the stoneware liner 16
`is inserted in the housing and permitting full power when the
`metallic insert or roaster function is desired.
`
`Accordingly, the present invention provides the advan-
`tages of two distinct cooking apparatuses in one multi-
`functional unit. A user may have the benefits of both a slow
`cooker and a roaster without having to purchase and store
`two separate units. The present invention also ensures that
`the appropriate heat output for each cooking function is
`provided.
`Thus, while there has been described what are presently
`believed to be the preferred embodiments of the present
`invention, other and further modification and changes can be
`made thereto without departing from the true spirit of the
`invention.
`It is intended to include all further and other
`modification and changes that would come within the true
`scope of the invention as set forth in the claims.
`What is claimed is:
`
`1. A cooking apparatus comprising:
`a housing having a base and a wall extending upwardly
`therefrom forming an interior;
`a heating device positioned in said interior;
`a sensor operatively connected to said heating device, said
`sensor upon actuation thereof affecting a heat output
`generated by said heating device;
`a first and second cooking insert each separately position-
`able within said housing interior; and
`said first cooking insert actuating said sensor when posi-
`tioned in said housing interior, and said second cooking
`insert not actuating said sensor when positioned in said
`housing interior.
`
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