(12) United States Patent
`DeC0hert et al.
`
`(10) Patent N0.:
`(45) Date of Patent:
`
`US 6,573,483 B1
`Jun. 3, 2003
`
`US006573483B1
`
`(54) PROGRAMMABLE SLOW-COOKER
`APPLIANCE
`
`4,695,683 A
`4,695,710 A
`4,742,864 A
`
`9/1987 Wingleretal.
`9/1987 Yamashita et al.
`5/1988 Duelletal.
`
`(75)
`
`Inventors: James E. DeC0bert, Attleboro, MA
`(US); Lorens G. Hlava, Clinton, MO
`(US); Charles T. Thrasher, Jr.,
`.
`C1m‘°“> MA (US)
`
`_
`_
`(73) Assigneez The H0ll11ES GFOHP, IIlC., M1lfOrd, MA
`(US)
`
`( * ) Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`USC. 154(1)) by 0 days.
`
`(21) APP1 N04 09/302474
`7
`~
`.
`Q“)
`Ffled‘
`Mar‘ 8’ 2001
`
`(60)
`
`(51)
`
`Provisional application No. 60/189,443, filed on Mar. 15,
`2000, and provisional application No. 60/196,273, filed on
`Apr. 5) 2000-
`
`Int. Cl.7 ................................................ .. H05B 1/02
`U.S. C].
`..................... ..
`
`219/435; 219/432; 99/340
`(58) Field of Search ............................... .. 219/433, 432,
`219/435, 506, 494, 518; 99/340
`
`(56)
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`............. .. 219/442
`
`3,681,663 A
`3,904,852 A *
`4,313,051 A
`4.-243,145 A
`. _
`g
`15:19:38 2
`5669802 A
`4,668,878 A
`4,674,890 A
`
`8/1972 Albers
`9/1975 Rivelli et al.
`1/ 1982 A0ShiII1a
`1
`8/1933 NOYWOOC1
`V
`a on
`1:15; 11;/Eei’ ‘H’ et a '
`1/1986 Koehler
`5/1987 Wyss
`6/1987 Kojima et al.
`
`\
`
`‘
`
`1'
`
` /1
`
`1
`
`‘
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`1
`1
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`4
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`340
`1
`l
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`~46
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`:54
`
`A
`
`4>Z49>874 A
`jggégigg 2
`4’83<’349 A
`,
`3,
`4 841496 A
`4,857,758 A
`‘£959,512 A
`5,191,231 A
`5,430,598 A
`5,477,029 A
`5,539,185 A
`5,596,552 A
`5,615,604 A
`5 734 149 A
`5,771,207 A
`5,834,718 A
`5,910,265 A *
`213:??? :1,
`6229307 B1
`6’274’847 B1 ,,
`,
`,
`
`.
`6/1988 M61511“
`lifiggg §°‘1V“1eW:k‘1et“1'
`5
`a one 6 a '
`/1989 Weber
`6/1989 Adams et al.
`8/1989 Rigazio et al.
`9/1990 Cole et al.
`3/1993 Berry
`7/1995 Rodolfo et al.
`12/1995 Skutt et al.
`7/1996 Polster
`1/1997 Lim
`4/1997 Chenglin
`l.
`3 1998 Sk
`6/1998 M111i*t<5iect:taal.
`11/1998 Amonett
`6/1999 Baker et al.
`2/3331 2::
`5/2001 Nakizjniliiiriaiiicitiiiiiiiiiiiii "
`8/2001 H1,
`,
`L ,1
`'
`ava e a .
`.............. ..
`
`................ 219/454
`
`219/433
`
`GB
`
`FOREIGN PATENT DOCUMENTS
`2001091
`4<
`5‘/1981
`............... N 219/433
`
`* cued by exarmner
`
`Primary Examiner—Mark Paschall
`Attorney, Agent, or FLrm—Br1nks Hofer Gilson &
`ione
`
`(57)
`
`ABSTRACT
`
`Aprograrnmable slow-cooker appliance, in which a user sets
`a ti111e and temperature for cooking a food item. Aprogram-
`mable controller prevents the unit from being used solely as
`.
`.
`.
`a “keep warm” appliance, and a unique design allows
`cooling of the controller during cooking.
`
`19 Claims, 12 Drawing Sheets
`
`.1
`
`12
`
`/
`
`121,4
`
`710
`
`7
`
`1
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`L
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`
`1i:iiir§§—P}6 Exhibit 1018
`Euro-Pro Exhibit 1018
`Euro-Pro v. Acorne
`Euro-Pro v. Acorne
`Page 1 of 17
`IPR2014-00186
`Page 1 of 17
`Page 1 of 17
`
`

`
`U.S. Patent
`
`Jun. 3, 2003
`
`Sheet 1 of 12
`
`US 6,573,483 B1
`
`:J———____—..——__
`
`_ __-_____,»_--___=.-..--,
`
`
`FIG. 1
`
`26
`
`FIG. 2
`PRIOR ART
`
`Page 2 of 17
`Page 2 of 17
`
`

`
`U.S. Patent
`
`Jun. 3, 2003
`
`Sheet 2 of 12
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`US 6,573,483 B1
`
`FIG. 3
`PRIOR ART
`
`Page 3 of 17
`Page 3 of 17
`
`

`
`U.S. Patent
`
`Jun. 3, 2003
`
`Sheet 3 of 12
`
`US 6,573,483 B1
`
`FIG. 4
`
`Page 4 of 17
`Page 4 of 17
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`

`
`U.S. Patent
`
`Jun. 3, 2003
`
`Sheet 4 of 12
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`US 6,573,483 B1
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`Page 5 of 17
`Page 5 of 17
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`

`
`U.S. Patent
`
`Jun. 3, 2003
`
`Sheet 5 of 12
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`US 6,573,483 B1
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`Page 6 of 17
`Page 6 of 17
`
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`Page 7 of 17
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`

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`U.S. Patent
`
`Jun. 3, 2003
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`Sheet 7 of 12
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`US 6,573,483 B1
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`Page 8 of 17
`Page 8 of 17
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`

`
`U.S. Patent
`
`Jun. 3, 2003
`
`Sheet 8 of 12
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`US 6,573,483 B1
`
`256C
`
`256a
`
`FIG. 9
`
`Page 9 of 17
`Page 9 of 17
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`

`
`U.S. Patent
`
`Jun. 3, 2003
`
`Sheet 9 of 12
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`US 6,573,483 B1
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`Page 10 of 17
`Page 10 of 17
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`

`
` U.S.Patent
`
`Jun. 3, 2003
`
`Sheet 10 of 12
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`US 6,573,483 B1
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`Page 11 of 17
`Page 11 of 17
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`

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`U.S. Patent
`
`Jun. 3, 2003
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`Sheet 11 of 12
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`US 6,573,483 B1
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`Page 12 of 17
`Page 12 of 17
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`

`
`..lHE4|.aP&U
`
`Jun. 3, 2003
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`Sheet 12 of 12
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`Page 13 of 17
`Page 13 of17
`
`
`
`

`
`US 6,573,483 B1
`
`1
`PROGRAMMABLE SLOW-COOKER
`APPLIANCE
`
`This application claims priority to Provisional Applica-
`tion No. 60/189,443, filed Mar. 15, 2000, and to Provisional
`Application No. 60/196,273, filed Apr. 5, 2000.
`
`BACKGROUND OF THE INVENTION
`
`Time and convenience are in short supply for homemak-
`ers wishing to supply a home-cooked meal to family mem-
`bers. Some appliances, such as slow—cooker appliances,
`attempt to meet this need by providing all-day cooking while
`a homemaker is absent. Such appliances, however, tend to be
`of the type where only one temperature and all day cooking
`is possible, regardless of the food item, and thus potentially
`subjecting the food item to over- or under-cooking. Another
`option may be to use a cooking unit with a controller, where
`a user may set a time or temperature desired. These units,
`however, tend to be quite a bit larger and more expensive
`than slow—cooker appliances. If these units are of more
`reasonable size,
`they also suffer because the controller
`inevitably must be placed near the heating element.
`What is needed is a cooking appliance in which the user
`retains control over the time and temperature of cooking, but
`which is small enough to be convenient. What is needed is
`a slow—cooker unit in which the controller does not become
`
`overheated and damaged by the heating element.
`SUMMARY OF THE INVENTION
`
`One embodiment of the invention is a programmable
`slow—cooker appliance,
`including a heating unit, which
`includes upstanding sidewalls and a bottom wall. The side-
`walls and bottom encompass a heating area. The appliance
`includes a heating element mounted on the inner surface of
`the interior wall of the heating unit. In one embodiment, t1e
`cooking area may also encompass a cooking unit inside t1e
`heating unit, suitable for holding food to be cooked. T1e
`appliance includes a programmable controller mounted on
`its outside, and preferably mounted via a controller housing,
`which acts to insulate the controller from the heat of t1e
`appliance, preferably via a unique system of a heat sink and
`ventilation. The housing, on the side of the slow—cooker
`appliance, utilizes ventilation holes on its bottom and top to
`encourage a chimney effect, in which cool air from t1e
`surroundings is drawn into ventilation slots or holes at tie
`bottom of the housing. This air cools the controller, and t1e
`air is then expelled from ventilation holes on the top of t1e
`housing, convecting heat away from the controller.
`Another aspect of the invention is a method of using t1e
`programmable controller to ensure that food is cooked
`according to the desires of a user. The user provides a food
`item and places the food item into the slow—cooker
`appliance, as described above. The user sets a cooking time
`and temperature for the programmable slow—cooker unit,
`using the controls to set both the time and the temperature.
`The cooking time according to one embodiment may not be
`set less than four hours, and the temperature may not be set
`for less than 150 degrees Fahrenheit (66 degrees Celsius).
`This prevents a user from accidentally setting the cooker to
`a “warm” temperature, in which food would only be warmed
`but not cooked thoroughly before consumption. In one
`embodiment, if the user sets no time or temperature, b11t
`mcrcly turns the cooker on, the cooker defaults to a particu-
`lar time and temperature, set by the user or the factory, such
`as a default setting of four hours and 175 degrees Fahrenheit
`or eight hours and 150 degrees Fahrenheit.
`
`10
`
`15
`
`40
`
`45
`
`60
`
`65
`
`2
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`FIG. 1 is a perspective view of an embodiment of a prior
`art slow—cooker appliance having an oval shape that may be
`utilized in the present invention;
`FIG. 2 is a perspective view of a prior art embodiment of
`a cooking unit 14 which may be utilized with the appliance
`of FIG. 1;
`FIG. 3 is a perspective View of a prior art cooking unit 39
`similar to that shown in FIG. 2, but having a circular shape;
`FIG. 4 is a perspective view of a slow cooker appliance
`incorporating the present invention;
`FIG. 5 is a detailed plan view of a portion of the control
`200 of the embodiment of FIG. 4;
`FIG. 6 is a bottom plan view of the embodiment of FIG.
`
`4;
`
`FIG. 7 is a side cutaway view of the embodiment of FIG.
`
`4;
`
`FIG. 8 is a plan view of a heat sink 256 as utilized in the
`embodiment of FIG. 4;
`FIG. 9 is a side View taken along a line 9—9 of FIG. 8;
`FIGS. 10 and 13 are schematic circuit diagrams showing
`the circuitry and components implemented in preferred
`embodiments;
`FIG. 11 is a wiring diagram showing some of the electric
`componentry of the preferred embodiment; and
`FIG. 12 is an embodiment of the front panel.
`DETAILED DESCRIPTION OF THE DRAWINGS
`AND PREFERRED EMBODIMENTS
`
`Referring to FIG. 1, one prior art embodiment of a
`food-heating slow—cooker appliance 10 is shown. The appli-
`ance 10 preferably comprises a heating unit 12 and a
`cooking unit 14. An exemplary slow cooker appliance 10
`may be a Crock-Pot® Slow Cooker made by The Rival
`Division of The Holmes Group® of Milford, Mass. The
`heating unit 12 preferably has a bottom 16 and a continuous
`outer sidewall 18. The bottom 16 and an interior sidewall 17
`define a well-like heating chamber 20 having an oval
`cross-section, and the interior sidewall 17 defines an annular
`lip 22 at an upper edge of the outer sidewall 18 and the
`interior sidewall 17. The heating chamber 20 has a heating
`element 24 disposed therein and mounted to the heating unit
`12, either under the bottom 16 or additionally between the
`outer sidewall 18 and the interior sidewall 17. A control
`switch 26 is conventionally used to provide electricity to the
`heating element 24. The heating element 24 functions to heat
`the cooking unit 14 via the heating chamber 20.
`As shown in FIG. 2, the cooking unit 14 has a bottom 28
`with preferably a continuous sidewall 30 upstanding there-
`from. The continuous sidewall 30 preferably has an annular
`lip 38 projecting in flange-like fashion from the upper end
`thereof and a substantially oval cross-section. The cooking
`unit 14 is adapted to be at least partially received within the
`heating 11nit 12 with the ann11lar lip 38 of the cooking unit
`14 preferably engaging the annular lip 22 of the heating unit
`12, supporting the cooking unit 14 within the heating unit
`12. Preferably, the annular lip 38 further defines a pair of
`handle portions 38(a) and 38(b) to facilitate lifting the
`cooking unit 14. The cooking unit 14 is preferably made of
`ceramic with a coating of conventional glazing compound.
`The thermal and hcat rctaining properties of thc ccramic
`cooking unit 14 allow it to conduct heat from the heating
`chamber 20 through the sidewall 30. This provides even
`Page 14 of 17
`heating throughout the unit 14.
`Page 1 4 of 1 7
`
`

`
`US 6,573,483 B1
`
`3
`As shown in FIG. 3, an alternative embodiment of the
`appliance 10 includes a cooking unit 39 having a sidewall 40
`and a substantially circular cross—section. This embodiment
`is preferably adapted to fit within a heating unit having a
`complementary circular heating chamber. This cooking unit
`39 is used in an embodiment of the present invention shown
`in FIG. 4.
`
`In 11se, the heating 11nit 12 is provided with a first cooking
`unit 39. The heating element 24 (not shown) may be
`powered on and off as necessary to supply heat at a main-
`tained temperature to the cooking unit 39 and the heating
`chamber via a programmable control 200. The control 200
`preferably includes a circuit board housing 210, a control
`panel 220, and an insulation shield 222 assembled together
`for attachment to the outer sidewall 18 of the heating unit 12.
`The interior of the housing 210 contains a printed circuit
`board 254 (shown in FIG. 7) containing electronic compo-
`nents of the control.
`
`10
`
`15
`
`As shown in FIGS. 5 and 6, the housing 210 preferably
`includes a control panel user interface 224 located on an
`inclined front surface of the housing 210. Preferably, the
`housing 210 and insulation shield 222 are made from a
`thermoplastic material such as polypropylene. A pair of side
`walls 226, a top wall 228, and bottom wall 230 are prefer-
`ably located adjacent the control panel 224 and support the
`control panel 224 in an inclined position away from the front
`of the cooking appliance 10. This gives the user access to the
`control panel 224, and also locates the controls and com-
`ponentry within the housing 210 away from a significant
`amount of the heat generated by the appliance 10. The
`printed circuit board 254 may be mounted via threaded
`screws 255 to rearwardly projecting screw receiving por-
`tions 258 on the rear side of the housing 210.
`The control panel 224 includes a plurality of indicator
`lights, s11ch as LEDs 262, spaced on the front panel 224. As
`is well-known in the art, a variety of other indicator devices
`may be provided, including digital re adouts, audible alarms,
`liquid crystal displays, incandescent lamps or fluorescent
`readouts. Preferably, the control panel 224 also includes a
`plurality of cantilevered portions 264 and 266 as shown in
`FIG. 5. The cantilevered portions 264, 266 preferably
`include rearwardly projecting fingers 268 (shown in FIG. 7)
`which translate the depression of the portions 264, 266
`toward the rear portion of the housing 210. The fingers 268
`are preferably used to depress pushbutton switch portions
`located on the circuit board 254. Awater-impermeable label
`membrane may be applied over the front of the control panel
`224 to label the indicators 262 and cantilevered portions 264
`and 266 for the user. The membrane may also protect the
`front control panel 224 from damage from spilled foods or
`liquids and facilitate cleaning.
`To further protect the electronic componentry within the
`housing 210 from the heat generated by the appliance 10, the
`annular shield member 222 is preferably sized for interpo-
`sition between the heating unit 12 and the housing 210. In
`particular, as shown in FIGS. 5 and 6,
`the shield 222
`includes a top wall 232, a pair of side walls 234, and a
`bottom wall 236. The shield 222 acts as a ventilated spacer
`to hold the electronic components and the housing 210 at a
`distance away from sidewall of the cooking unit 12.
`In order to dissipate heat that may otherwise be retained
`between the cooking unit 12 and the rear of the housing 210,
`an air circulation space is provided within the shield. In
`particular, as shown in the side cutaway view of FIG. 7, the
`air space 240 behind the shield 222 may vent warmer air out
`through an upper elongated slot 242 defined within the top
`
`40
`
`45
`
`60
`
`65
`
`4
`wall 232 of the shield 222. Likewise, an elongated slot 244
`is defined into the air space 240 in the bottom wall 236 of
`the shield 222. Heated air may thus escape through the top
`elongated slot 242 and cooler air may enter the air space 240
`through the bottom elongated slot 244. As shown in FIG. 7,
`the shield 222 also preferably defines a rearwardly project-
`ing cylindrical flange 246 that extends into the outer wall 18
`to allow passage of control and power wiring between the
`interior of the heating unit 12 and the interior of the housing
`210.
`
`In a similar fashion, air circulation is promoted through
`the housing 210 through a set of openings, preferably
`defined between the upper portion and the bottom of the
`housing 210. In particular, a plurality of openings 250 are
`defined within the bottom wall 230 of the housing 210. An
`elongated upper slot 252 is provided on the front face 224 of
`the housing 210. This allows air to freely circulate behind
`the control panel 224 and assist in the dissipation of heat
`from the circuit board 254 and its electronic componentry
`within the housing 210. Preferably, a heat sink 256 is
`provided as shown in FIG. 7 and positioned between the
`circuit board 254 and the front panel 224 inside the housing
`210. The sink 256 preferably includes a plurality of openings
`defined therein to allow air to circulate between the openings
`250 and 252 and through and around the heat sink 256 to
`dissipate additional heat therefrom. Also shown is the rela-
`tive position of cooking unit 14.
`FIGS. 8 and 9 show a detailed view of the heat sink 256.
`
`Preferably, the heat sink is machined from 0.063 inch thick
`3003-0 anodized aluminum. The heat sink 256 is preferably
`bent at a 160 degree angle between a bottom flange portion
`256a and an upper portion 256b. A centrally located retain-
`ing tab portion 256C is bent parallel with the lower portion
`256a, and the portions 256a and 256C are used for attach-
`ment of the he at sink 256 to the rear side of the housing 210
`interior via the rearwardly projecting screw receiving por-
`tions 258. To maximize the dissipation of heat, a plurality of
`winged sections 257 and 259 are provided on the heat sink
`256 and extend outwardly from a center portion 256a of the
`heat sink 256. A plurality of openings are defined through
`the heat sink 256 to allow the fingers 258 of the control panel
`cantilevered portions 264, 266 to project through the heat
`sink and contact the circuit board 254 at the rear of the
`
`housing 210. The openings 251 also facilitate cooling air
`flow through and past the heat sink 256 to further dissipate
`heat therefrom.
`
`The circuit board 254 mounts circuitry and logic allowing
`the user of the appliance 10 to electronically control and
`program cooking cycles and temperature. A schematic dia-
`gram of the electronic circuitry and components is shown in
`FIG. 10. The diagram shows a preferred exemplary circuit
`incorporating preferred components as utilized in the pre-
`ferred embodiment of the present invention. One skilled in
`the art will recognize that the componentry illustrated herein
`is exemplary only and that many other components may be
`substituted to achieve the functions described herein. FIG.
`10 includes labels for each of the components of the circuit,
`and only major components will be described herein.
`
`First, as shown in the diagram, the preferred circuit 300 is
`preferably built around an EPROM/ROM-based CMOS
`microprocessor controller 302, such as the PIC16CR54C
`RISC CPU manufactured by Microchip Technology, Inc.
`The chip output preferably includes circuited drivers for 6
`LED indicators 262 (labeled D3—D8) as shown. These LED
`indicators may be assigned labels as follows:
`Page 15 of 17
`Page 15 of 17
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`

`
`US 6,573,483 B1
`
`5
`
`Indicates
`
`On
`WARM
`4 HOUR
`6 HOUR
`8 HOUR
`10 HOUR
`
`LED
`
`D3
`D4
`D5
`D6
`D7
`D8
`
`10
`
`Two momentary pushbutton contact switches S1 and S2 are
`used to trigger the “Off” and “Cook” features, respectively,
`as will be described in the cooking procedure below. Of
`course, other indicators and switches may be substituted.
`Note that while examples are given, the circuitry may be
`implemented in numerous ways, as is well-known in the art,
`to accomplish the varying programming modes described
`below.
`The temperature of the cooking appliance is measured ,
`using a thermistor 310, which is connected externally of the
`circuit board to the underside of the bottom of the heating
`chamber. A retention clip 320, shown in FIG. 7, is utilized
`to hold the thermistor in thermal contact with the bottom 16.
`
`15
`
`the appliance uses a model
`In a preferred embodiment,
`USX1732 thermistor manufactured by U.S. Sensor, Inc.
`Triac 304, which is preferably a logic Triac Model
`L4008L6-ND manufactured by Digi-Key, Inc., is utilized to
`switch the power supplied to the heating elements of the
`appliance. Preferably, the Triac is of an isolated tab type and
`includes a heat sink tab that is fastenable to the heat sink 256
`shown in FIGS. 8 and 9. Preferably, the Triac is mounted
`separately to one of the mounting holes on the center portion
`256a of the heat sink 256 so that the tab is in thermal contact
`with the heat sink 256 to dissipate heat generated from its
`current controlling function. Most of the other components
`of the circuit 300 are mounted on a conventional printed
`circuit board 254.
`
`FIG. 11 shows the wiring of the external Triac 304 in
`relation to the circuit board 254 and heating elements 24. As
`shown in the Figure, the heating elements 24 are in thermal
`contact with and wrapping around the interior sidewall 17 of
`the heating unit.
`The operation of the appliance 10 is as follows. The
`programmable circuitry 300 allows the user to set both the
`temperature and desired time for cooking. The functions of
`the switches S1 and S2, which are activatable via the
`cantilevered portions 264 and 266 of the control panel 224,
`are as follows:
`
`40
`
`45
`
`S1. OFF pushbutton—turns the appliance 10 off.
`S2. COOK pushbutton—subsequent pushes of the button
`cycle through 4 hour, 6 hour, 8 hour and 10 hour cook
`times.
`the power “on” indicator
`When the unit is plugged in,
`flashes. The user then pushes the COOK button (switch S2)
`to set the temperature and cooking time. As the user pushes
`the COOK switch S2,
`the LED’s D5—D8 illuminate to
`indicate the corresponding time setting as follows.
`LEDs
`
`D3. POWER—on when appliance 10 is in cook or warm
`modes.
`
`D5. 4 HOUR—on when appliance is in 4-hour cook mode
`D6. 6 HOUR—on when appliance is in 6-hour cook mode
`D7. 8 IIOUR—on when appliance is in 8-hour cook mode
`D8. 10 HOUR—on when appliance is in 10-hour cook
`mode
`
`60
`
`65
`
`6
`D4. WARM—on when appliance is in half-power mode
`Thus, subsequent pushes of the COOK switch S2 activate
`different cooking modes, as shown by the 6 HOUR, 8
`HOUR and 10 HOUR LEDs 262 on the control panel 224.
`If the COOK switch S2 is pressed in the 10 HOUR mode,
`the control 200 recycles to the 4 HOUR cooking mode, and
`its indicator.
`In general, full power will be applied to the heating
`element 24 until the time corresponding to the illuminated
`LED elapses, after which the power to the heating element
`24 is reduced by half, the WARM indicator illuminates and
`all cook time indicators extinguish. The choices of operation
`are: 4 or 6 hours on a HI temperature, and 8 to 10 hours on
`a lower temperature setting. Once the user selects the desired
`setting, the appliance 10 starts the cooking operation. Once
`the time setting has expired, the appliance 10 automatically
`reduces power to the heating element 24 to p11t the 11nit in a
`WARM setting. The unit will stay in the WARM setting until
`the user pushes the OFF button or unplugs the unit. Of
`course, other programming schemes are possible.
`Preferably, the user cannot set the unit initially in the
`WARM setting. The system will only go to WARM after one
`of the time functions has expired. This avoids possible food
`safety problems that may be associated with cooking food
`only on the WARM setting. Pressing the OFF switch S1 any
`time the unit is on preferably removes power from the
`heating element 24 and extinguishes all indicator LEDs 262.
`In another embodiment,
`the slow-cooker appliance uti-
`lizes four push-button switches, rather than two, to set times
`and temperatures for cooking. An exemplary control panel is
`depicted in FIG. 12, with control circuitry in FIG. 13. Four
`momentary pushbutton contact switches 227, 229, 231, 233
`are used to trigger various power and setting functions as
`will be described in the cooking procedure below. Of course,
`other numbers or types of indicators and switches may be
`substituted as well. FIG. 13 shows circuitry applicable to
`such an embodiment, incorporating controller 302, external
`temperature element 310, digital readout 57, and Power
`LED 263 and Timer LED 265. The Power LED indicates
`power is present at the microprocessor controller and the
`Timer LED indicates that
`the Timer function is on and
`
`working.
`The operation of the appliance is as follows. The pro-
`grammable circuitry allows the user to set both the tempera-
`ture and the desired cooking time. The functions of the
`switches 227, 229, 231, 233 on an alternative embodiment
`of a control panel user interface 225, are as follows:
`227. ON/OFF power pushbutton—turns the appliance on
`and off.
`
`229. TIMER pushbutton—activates stepped timer.
`231. UP pushbutton—increases displayed numerical
`value.
`
`233. DOWN pushbutton—decreases displayed numerical
`value.
`
`When the unit is plugged in, the unit defaults to 150-
`degrees F. as shown on the digital display 57. The user may
`adjust the desired cooking temperature in 25-degree incre-
`ments using the UP 231 button or the DOWN button 233,
`with 150 degrees Fahrenheit as a minimum temperature.
`Once the user has selected the specific temperature, the
`appliance will start the cooking process.
`The user may also select the TTMER mode by pressing the
`TIMER button 229. In TIMER mode, the controller defaults
`to 4 hours. The user can use the UP or DOWN controls to
`increase or decrease the time in 15-minute increments. Once
`the time is set, the controller 302 will count down the time
`remaining for cooking in 1 minute increments until the unit
`
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`

`
`US 6,573,483 B1
`
`5
`
`10
`
`15
`
`7
`“times out”. At that time, the power is shut off from the
`heating element.
`In all modes, the temperature is read periodically by the
`thermistor or other temperature element and relayed to the
`controller. The reading is checked at 4-second intervals. If
`the temperature is above or equal to the set point, power is
`removed. If it is below the set point, power is applied to the
`heating element 32. Of course, the circuitry can be modified
`as desired to achieve various program methods and modes.
`Another embodiment of the slow cooker appliance adds a
`piezobuzzer to the circuitry. A piezobuzzer is simply an
`electrically-activated buzzer that can be programmed to emit
`a sound at desired moments.
`In one cmbodimcnt, a
`piezobuzzer may be installed as an output 315, controlled by
`the microprocessor controller 302, as shown in FIG. 13, and
`programmed to emit a sound when desired.
`In one
`embodiment, the buzzer may beep to provide feedback to a
`user when a pushbutton is pushed. The slow cooker may also
`be programmed to emit a sound to indicate the end of the
`cooking time. The buzzer may also be used to emit sounds '
`at other desired times.
`It is intended that the foregoing description illustrates
`rather than limits this invention, and that it is the following
`claims, including all equivalents, which define this inven-
`tion. Of course, it should be understood that a wide range of
`changes and modifications may be made to the embodiments
`described above. Accordingly,
`it is the intention of the
`applicants to protect all variations and modifications within
`the valid scope of the present invention. It is intended that
`the invention be defined by the following claims, including
`all equivalents.
`What is claimed is:
`
`/
`
`1. Aprogrammable slow-cooker appliance, comprising:
`a heating unit;
`a cooking unit adapted to fit at least partially within the
`heating unit;
`a controller housing fixedly mounted to an outside of the
`heating unit; and
`a programmable controller mounted to the housing to
`control the heating unit, wherein said housing is con-
`figured to convect heat away from the controller.
`2. The slow-cooker appliance of claim 1, wherein the
`housing is an enclosure for at least a portion of the controller.
`3. The slow-cooker appliance of claim 2, wherein the
`controller housing insulates the controller from the heating
`unit.
`
`4. The slow-cooker appliance of claim 3, wherein the
`housing further comprises a heat shield, and the heat shield
`is made from a material selected from at
`least one of
`thermoplastics and insulating materials.
`5. The slow-cooker appliance of claim 4, wherein the
`housing defines ventilation openings configured to allow air
`to flow into and out of said housing.
`
`40
`
`45
`
`50
`
`8
`6. The slow-cooker appliance of claim 5, wherein the
`housing includes at least a pair of slots defined in an upper
`and lower part of the housing to define airflow thru the slots
`and behind the controller.
`7. The slow-cooker appliance of claim 1, wherein the
`controller further comprises control elements and a display.
`8. The slow-cooker appliance of claim 7, wherein the
`control elements are selected from the group consisting of a
`control panel, p11sh-buttons, switches, and a digital readout.
`9. The slow-cooker appliance of claim 1, further com-
`prising a temperature measuring device in communication
`with said controller.
`
`10. The slow-cookcr appliancc of claim 1, further com-
`prising a piezobuzzer.
`11. A control housing for a slow cooker heating unit, said
`housing comprising:
`a front wall;
`a bottom wall defining at least one lower opening, the
`bottom wall attached to the front wall;
`a top wall defining at least one upper opening, the top wall
`attached to the front wall; and
`a circuit board mounted behind the front wall, the circuit
`board apart from a wall of the heating unit.
`12. The control housing of claim 11, further comprising a
`heat sink between the circuit board and the front wall.
`
`13. A method of using a programmable slow-cooker
`appliance, the method comprising:
`providing a food item;
`placing the food item into a cooking unit of the slow-
`cooker appliance,
`selecting a cooking temperature and time using a pro-
`grammable controller mounted to a housing fixedly
`mounted to a heating unit; and
`changing the heating unit temperature automatically to a
`lower temperature after the selected time.
`14. The method of claim 13, further comprising notifying
`a user with illuminated indicators that
`the slow-cooker
`appliance is powered and that the timer is active.
`15. The method of claim 13, wherein the temperature is
`set by default upon selection of a cooking time.
`16. The method of claim 13, wherein the time is selected
`from the group consisting of 4 hours, 6 hours, 8 hours and
`10 hours and the temperature is selected from the group
`consisting of high and low.
`17. The method of claim 13, wherein the temperature and
`time are set in increments.
`
`18. The method of claim 13, further comprising cooling
`the electronic circuitry of the programmable controller via a
`chimney effect.
`19. The method of claim 13, further comprising emitting
`a sound.
`
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