U.S. patent application number 14/069886 was filed with the patent office on 2014-05-01 for electronically controlled warmer drawer.
This patent application is currently assigned to Western Industries, Inc.. The applicant listed for this patent is Richard C. Hochschild, JR., Scott A. Jonovic. Invention is credited to Richard C. Hochschild, JR., Scott A. Jonovic.
Application Number | 20140116267 14/069886 |
Document ID | / |
Family ID | 39640228 |
Filed Date | 2014-05-01 |
United States Patent
Application |
20140116267 |
Kind Code |
A1 |
Hochschild, JR.; Richard C. ;
et al. |
May 1, 2014 |
Electronically Controlled Warmer Drawer
Abstract
An electronically controlled warmer drawer for food or non-food
items having a housing including a heating element based on several
heat-producing technologies, temperature and/or humidity sensor(s),
and a fan to effectively warm items placed therein. The system is
controlled by way of the user interface that interacts with an
electronic control system to operate the heating element and fan.
The user interface provides user programmable controls and
automatic overrides, can be placed in a variety of locations, and
can be concealed by a variety of elements. The interface can also
utilize a variety of touch sensitive technologies. As well, the
device may have a receptacle for adding fragrance or flavor to the
objects within.
Inventors: |
Hochschild, JR.; Richard C.;
(Grafton, WI) ; Jonovic; Scott A.; (Cottage Grove,
WI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Hochschild, JR.; Richard C.
Jonovic; Scott A. |
Grafton
Cottage Grove |
WI
WI |
US
US |
|
|
Assignee: |
Western Industries, Inc.
Watertown
WI
|
Family ID: |
39640228 |
Appl. No.: |
14/069886 |
Filed: |
November 1, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13241370 |
Sep 23, 2011 |
|
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14069886 |
|
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Current U.S.
Class: |
99/473 ; 219/400;
219/413; 29/428; 99/483 |
Current CPC
Class: |
F24C 15/18 20130101;
F24C 7/087 20130101; A23L 3/3445 20130101; B23P 11/00 20130101;
Y10T 29/49826 20150115; Y10T 29/49002 20150115; A47J 36/2483
20130101; Y10T 29/49117 20150115; H05B 3/0071 20130101 |
Class at
Publication: |
99/473 ; 219/400;
219/413; 29/428; 99/483 |
International
Class: |
A47J 36/24 20060101
A47J036/24; B23P 11/00 20060101 B23P011/00; A23L 3/3445 20060101
A23L003/3445 |
Claims
1. A warmer drawer comprising: a housing having a cavity; an
extendable portion slidably connected to the housing, wherein the
extendable portion is sized to fit within the cavity; a door
connected to the extendable portion; a heating element located in
the cavity; a fan for moving heated air within the cavity;
electronic controls for operating the fan and the heating element;
and a sensor in communication with the electronic controls for
controlling a humidity in the cavity and a current supplied to the
heating element.
2. The warmer drawer of claim 1, further comprising a venting
system that is controlled by the humidity sensor and the electronic
controls to open and close one or more vents in the cavity and
control an air flow through the one or more vents.
3. The warmer drawer of claim 1, further comprising a panel
configured to conceal the electronic controls, wherein the panel is
one or more selected from a group comprising a sliding panel, a
sliding spring-biased panel, a sliding panel display, a panel on a
rotating element, an L-shaped plate, a matching panel, and a
portion of a rotating element having at least one electronic
control thereon.
4. The warmer drawer according to claim 1, wherein the electronic
controls comprise programmable on/off settings having automatic
shutoff with an infinite setting of the automatic shutoff to
disable the automatic shutoff.
5. The warmer drawer of claim 1, further comprising a receptacle
for receiving aromatic materials wherein the aromatic materials are
one or more selected from a group consisting of a fragrance source,
a flavoring additive, wood chips, and a liquid smoke.
6. The warmer drawer of claim 1, wherein the heating element is one
or more selected from a group consisting of a convection heater, a
calrod, a heat plate, a glass film, a thermal ceramic heater, a
flexible heater, a light, an infrared device, an inductive device,
an electromagnetic device, a radio frequency device, a heat pump, a
warming liquid device, a heat exchanger, an axial fan heater, a
sonic heater, a gas fuel product, a solid fuel product, a radiant
heating device, and a microwave device.
7. The warmer drawer of claim 1, wherein the electronic controls
comprise an electronic display touch control panel having one or
more input elements configured to respond to a user input and at
least one operating technology of the input elements is one or more
selected from a group consisting of a piezo electric, a capacitive,
a resistive, and an infrared.
8. The warmer drawer of claim 1, further comprising at least one of
an upper chamber and a lower chamber wherein the fan is located in
one or both of the upper chamber and lower chamber.
9. The warmer drawer of claim 1, wherein the electronic controls
are located on at least one of the extendable portion and the
door.
10. The warmer drawer of claim 9, wherein the electronic controls
are configured to be concealed by an overlying panel by moving the
extendable portion to a closed position.
11. A method of manufacturing a warmer drawer, comprising steps of:
defining an enclosure with a chamber and having an opening;
configuring a movable portion to be moved with respect to the
chamber; providing a heating element to heat the chamber;
configuring a user interface to receive input from a user for
controlling operation of the warmer drawer; providing a sensor to
sense a signal representative of a temperature of the chamber;
configuring an electronic control system for interfacing with the
heating element, the user interface, and the sensor to control a
supply of electrical power in a continuous and regulated manner to
the heating element during operation of the warmer drawer; and
controlling the humidity in the chamber.
12. The method of claim 11, further comprising the step of
providing a second sensor selected from the group consisting of a
humidity sensor, a temperature sensing, a thermostat, a thermal
protector, a thermal cutoff, a thermal switch, a thermocouple, a
PCB thermostat, a time delay relay, a bulb and capillary device, a
cold control, a bimetallic device, a pressure switch, a resistance
temperature detector, a snap action switch, and a thermistor
device, configured to interface with the electronic control
system.
13. The method of claim 11, further comprising the step of
connecting the user interface having an electronic display touch
control panel configured to provide information to a user.
14. The method of claim 13, wherein the step of connecting the user
interface having the electronic display touch control panel
utilizes a display panel having technology selected from the group
consisting of light-emitting diodes, a liquid crystal display, a
plasma, a dot matrix, and a vacuum fluorescent display.
15. The method of claim 1, further comprising the step of providing
an element configured to hide the user interface.
16. The warmer drawer of claim 1, further comprising a partition
within the cavity that divides the cavity into an upper chamber and
a lower chamber.
17. The warmer drawer of claim 16, further comprising a back plate
that includes a plurality of apertures, and wherein the back plate
is positioned within the cavity so as to form a space between a
back wall of the warmer drawer and the back plate, and wherein the
fan forces air into the space, through the apertures, and into the
lower chamber.
18. The warmer drawer of claim 1, wherein a humidity inside the
cavity is controlled by the humidity sensor and the electronic
controls by regulating the fan.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims a benefit of priority based on U.S.
Non-provisional patent application Ser. No. 13/241,370, filed Sep.
23, 2011, the entire contents of which are hereby expressly
incorporated by reference into the present application. U.S.
Non-provisional patent application Ser. No. 12/017,895, filed Jan.
22, 2008, the entire contents of which are hereby expressly
incorporated by reference into the present application. U.S.
Non-provisional patent application Ser. No. 12/017,895 claims a
benefit of priority of U.S. Provisional Patent Application Ser. No.
60/886,037, filed Jan. 22, 2007, and U.S. Non-provisional patent
application Ser. No. 11/216,443, filed Aug. 31, 2005. The entire
contents both applications are hereby expressly incorporated by
reference into the present application. U.S. Non-provisional patent
application Ser. No. 11/216,443 application claims a benefit of
priority of U.S. Provisional Patent Application Ser. No.
60/622,185, filed Oct. 26, 2004, the entire contents of which are
hereby expressly incorporated by reference into the present
application, and claims a benefit of priority of U.S. Provisional
Patent Application Ser. No. 60/606,396, filed Sep. 1, 2004, the
entire contents of which are hereby expressly incorporated by
reference into the present application.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a warming apparatus and,
more particularly, to an electronically controlled warming
apparatus and an electronically controlled warming drawer.
[0004] 2. Discussion of the Related Art
[0005] Warmer drawers of conventional design are typically
configured as closed boxes, having a construction of single wall or
a double wall with insulation or air in between and a sliding
drawer of some sort to open up the interior of the box. Such
conventional warmer drawers often have front door(s) fixed in a
vertical plane and heating of the interior has been by a single cal
rod (i.e., sheathed heating element) which will radiate heat, thus
warming the interior of the box.
[0006] The conventional warmer drawers use mechanical controls to
control and maintain the food temperatures. These mechanical
controls tend to have an undesirable degree of inaccuracy and have
a tendency to dry out food, overheat, and have large swings in
temperature ranges from a desired set point, which results in over
and under shoots.
[0007] These sensors and the design of operation generally cause
slow response for temperature corrections, thus causing
temperatures to over shoot and under shoot. These resulting
temperature ranges and swings, from the on to off cycling, have a
tendency to drive moisture out of foods, hold more moisture in the
chamber, and/or over cook food(s). Also, when set for the proofing
temperature, bread will not proof correctly (i.e., not to rise
properly) at lower temperatures, and at the higher temperatures
bread tends to develop large pockets of air.
[0008] Conventional warmer drawer designs typically use knobs and
slides to set and control mechanical switches for setting the
desired temperature. However, these mechanical switches are
generally known to be inaccurate in their setting and
repeatability. The mechanical switches often have problems
maintaining a set point and can permit swings in temperature within
the chamber partly due to the design of the warmer drawer and
method of heating, but also due to the inaccuracy of the mechanical
switches themselves. The inaccuracy of the mechanical switches
tends to increase the effects of having temperature over and under
shoots and contributes to the large temperature swings inside the
chamber of the warmer drawer. This inaccuracy is believed to
contribute greatly to the gradient temperature problems found in
present warmer drawers with the chamber having problems with
temperature over shoot and under shoot.
[0009] The mechanical switches typically used in conventional
warmer drawers are also susceptible to the adverse effects of
surrounding environmental influences. For example, if subjected to
cold temperatures, mechanical switches could work slowly, crack,
become hard to turn, fail to operate, their lubrication can harden
causing the operation not to function, cause switch chatter
resulting in premature failure or reduced life of product, and
cause other detrimental issues to a user. Typical mechanical
switches and controls for conventional warmer drawers tend to have
poor repeatability and generally do not provide the user the
ability to repeatably return to a certain preset position (e.g.,
reuse of same settings, etc.) or reliably establish the same
temperature when using the conventional warmer drawer in a series
of different operations. For example, a user generally cannot set a
proper temperature on one day and then return the next day to the
same set point if the controls were moved during an intervening
period (as is often necessary). Temperature swings of as much as 30
degrees or more are believed to occur in such instances.
[0010] The conventional warmer drawers are also subject to other
deficiencies. For example, conventional warmer drawers are
typically constructed for use in permanent (e.g., built-in, etc.)
installations, such as to cabinetry, an appliance, or some other
generally stationary structure. Examples include conventional
warmer drawers built into a cabinet under a product such as a cook
top, oven, or some other appliance like a slide-in stove to a
drop-in range. In other applications, conventional warmer drawers
can be used in a location independently, but are still typically
built into a cabinet or some structural frame. This limits the
mobility of the warmer drawer from being used in a variety of
desirable locations. Accordingly, it would be desirable to provide
a warmer drawer capable of being used as a freestanding unit, as a
mobile unit, used under a cabinet (e.g., suspended), or in areas
with or without the support from a structural frame.
[0011] Therefore a need exists for a warmer drawer in which more
accurate and controlled heating of objects such as food is
accomplished. There also exists the need for an accurate method of
controlling the operations and settings of the warmer drawer. There
also exists a need for the controls of the warmer drawer to be less
susceptible to environmental influences. There also exists a need
for a display device to permit a user to be able to view/see the
operation, temperature indication(s), set point functions, and view
of the contents of the chamber. There also exists a need for a
warmer drawer capable of remote control operation. There is a
further need to accurately apply and control heat within the
chamber of the warming drawer. There is also needed for a warmer
drawer such that it can be used in any desirable location to suit
the particular needs of a user.
[0012] Accordingly, it would be desirable to provide a warming
apparatus, such as a warmer drawer having electronic control, with
any one or more of these or other advantageous features.
SUMMARY OF THE INVENTION
[0013] One object of this invention is to provide a warming
apparatus that has one or more of the characteristics discussed
below.
[0014] The present inventive warmer apparatus for either indoor or
outdoor use consists of an enclosure defining a chamber with a
heating element. A sensor system, preferably comprising at least
one sensor, is operably coupled to the chamber and sends signals to
an electronic control system that is operably connected to the
heating element and a user interface provided on the enclosure or
faceplate. A drawer is provided and is extendable from the chamber
of the warmer and a means for preventing fluids and other
contaminants from entering the chamber is also provided for between
the enclosure and the user interface and drawer.
[0015] The user interface, for example, an electronic control
panel, can be installed raised, recessed, or flush with the
enclosure and can be constructed out of glass, plastic, metal,
rubber or a composite material. The touch panel is preferably
sealed and/or coated to protect the electronic controls from being
damaged by the elements and to prevent fluids, insects, and other
contaminants from gaining entry to the chamber through the touch
panel. The touch panel may also include decorative overlays,
labels, and trims that are configured for outdoor use. The touch
panel may be mounted on the faceplate of the warmer or elsewhere on
the enclosure and may be disconnected from the enclosure and used
remotely by a wired or wireless controller. In another embodiment,
the user interface uses one of a tactile, membrane, piezoelectric,
capacitance, resistance, induction system, touch panel, or keypad
for the selection of various operations.
[0016] The warmer preferably includes a fixed or variable speed fan
that is located either in the chamber or remotely. Again, it may
also be attached to the heating element or independent of it. The
fan is used for mixing air, removing air, or controlling the
moisture within the chamber of the warmer.
[0017] The warmer can be used for non-food or food and drink items
alike. Flavoring additives may be added to the chamber so as to
impart various flavors or scents to the items being warmed within
the warmer.
[0018] The inventive warmer may also include a timer control that
may be programmed by a user to automatically turn off the warmer
after a certain amount of time. The warmer may also be capable of
preset temperatures, preset times, and preset operations.
[0019] The warmer's user interface may be configured to display the
current time, operations, temperatures, functions, remaining time,
diagnostics, features, fan speeds, alarm controls and signals,
messages, timed on/off, time delay or be remotely controlled by
voice or sound commands from the user.
[0020] The warmer may also comprise accessible panels or walls on
either its front, side, top, back, or bottom so that a user may
gain access to the chamber of the warmer. Furthermore, the warmer
may comprise additional warming chambers, e.g., one for food and
one for non-food items.
[0021] According to one aspect of the present invention a warmer
drawer is provided having a housing with a cavity, an extendable
portion slidably connected to the housing that fits within the
cavity, a door connected to the extendable portion, a heating
element located in the cavity, a fan for moving heated air within
the cavity, electronic controls for operating the fan and the
heating element, and a sensor in communication with the electronic
controls for controlling the current supplied to the heating
element. Thus it is one object of the invention to provide a drawer
for easy access to a warming chamber that effectively heats the
items in the drawer under the user's control.
[0022] According to another aspect of the present invention, the
warmer drawer may also have a panel configured to conceal the
electronic controls, which may be a sliding panel, a sliding
spring-biased panel, a sliding panel display, a panel on a rotating
element, a L-shaped plate, a matching panel, and a portion of a
rotating element having at least one electronic control. As well,
there may be a cabinet where the panel is located on at least one
extendable portion of the cabinet. Thus it is another object to
provide an attractive warmer drawer by allowing the electronic
controls of user interface to be concealed.
[0023] In yet another aspect, the invention's electronic controls
may include programmable settings such as on/off settings. The
programmable on/off settings may have automatic shutoff with an
infinite setting of the automatic shutoff to disable the automatic
shutoff. It is thus another object of the present invention to
provide several useful features, including for safety and
convenience, to allow the user to control the operation of the
warmer drawer operation.
[0024] In still another aspect of the present invention the warmer
drawer may have a receptacle for receiving aromatic materials
wherein the aromatic materials are one or more of a fragrance
source, flavoring additives, wood chips, and liquid smoke. Thus, it
is an object to provide flavor and fragrance to objects in the
drawer as well as warming.
[0025] In yet another aspect of the present invention, the warmer
drawer heating element may be a convection heater, a cal rod, a
heat plate, a glass film, a thermal ceramic heater, a flexible
heater, a light, an infrared device, an inductive device, an
electromagnetic device, a radio frequency device, a heat pump, a
warming liquid device, a heat exchanger, an axial fan heater, a
sonic heater, a gas fuel product, a solid fuel product, a radiant
heating device, and/or a microwave device. It is thus yet another
object to provide for a warming drawer having effective heating
technology.
[0026] In still another aspect, the warmer drawer's electronic
controls have an electronic display touch control panel with input
elements that respond to user input. The operating technology of
the input elements may of piezo electric, capacitive, resistive and
infrared. In addition, the electronic controls may located in a
variety of locations with respect to any plane on the drawer
assembly and/or door, for example, at a location that is flush,
raised, recessed, and may be recessed beneath glass, plastic, or
composite material. It is thus yet another object to provide for a
warming drawer having effective, attractive, and accessible
electronic control input technology.
[0027] In anther aspect, the warmer drawer may also have an upper
chamber and/or a lower chamber wherein the fan is located in one or
both. Thus, it is another object to provide for a warming drawer
that effectively heats the objects within the chamber.
[0028] In another aspect of the present invention the warmer drawer
electronic controls may be on the drawer assembly and/or the door.
Furthermore, the electronic controls may be concealed by moving the
drawer assembly to a closed position. Thus, it is another object to
provide controls that are easily accessible during the use of the
warmer drawer that may be concealed when the drawer is closed for
improved appearance.
[0029] In still another aspect of the present invention a method of
manufacturing a warmer drawer has steps of defining an enclosure
with a chamber and having an opening, configuring a movable portion
to be moved with respect to the chamber, providing a heating
element to heat to the chamber, configuring a user interface to
receive input from a user for controlling operation of the warmer
drawer, providing a sensor to sense a signal representative of a
temperature of the chamber, and configuring an electronic control
system for interfacing with the heating element, the user interface
and the sensor to control a supply of electrical power in a
continuous and regulated manner to the heating element during
operation of the warmer drawer. The movable portion may be a lid, a
drawer, or a door. Thus it is still another object to provide for a
method of manufacturing a warmer drawer configured for usage in a
flexible variety of uses.
[0030] In another aspect, the method of manufacturing a warmer
drawer may also include the step of providing a second sensor such
as a humidity sensor and/or a temperature sensing device. The
second sensor may be a thermostat, a thermal protector, a thermal
cutoff, a thermal switch, a thermocouple, a PCR thermostat, a time
delay relay, a bulb and capillary device, a cold control, a
bimetallic device, a pressure switch, a resistance temperature
detector, a snap action switch, and/or a thermistor. Thus, it is
another object to provide a method of manufacturing that produces a
warmer drawer that can additionally sense humidity or sense
temperature in more than one location to accurately monitor the
condition of the objects in the drawer.
[0031] In still another aspect, the method of manufacturing a
warmer drawer may also include the step of connecting the user
interface having a display device configured to provide information
to a user. The display device may use a display panel having
technology such as light emitting diodes, a liquid crystal display,
a plasma, a dot matrix, and/or a vacuum fluorescent display. The
method may have an additional step of providing an element
configured to hide the user interface such as a sliding panel, a
sliding spring-biased panel, a display that is substantially
similar to a surrounding surface, a panel on a rotating element,
and/or a portion of a movable element having at least one
electronic control. Thus, it is still another object of the present
invention to provide a user display device that may alternatively
be hidden from view to improve the warmer drawer aesthetics.
[0032] In yet another aspect, the method of manufacturing a warmer
drawer may also include the step of providing the user interface
that includes has one or more set points, timers, temperatures,
on/off settings, automatic shutoff, and/or an infinite setting
override of an on/off timer. Thus, it is another object to
manufacture a warmer drawer having programmable features for
ease-of-use.
[0033] In yet another aspect, the method of manufacturing a warmer
drawer may also include the step of providing a receptacle for a
source for fragrance, and/or a source for flavoring. Thus, it is an
object to a method of manufacturing a warmer drawer that provides
flavor and/or fragrance to objects in the drawer.
[0034] In yet another aspect, the method of manufacturing a warmer
drawer may also include the step of providing a user interface
comprising a touch screen having at least one input element
configured to respond to a user input wherein the touch screen may
have input element(s) that are displayed in response to a user
input. The touch screen operating technology may be piezo electric,
capacitance, inductive, resistance, infrared, magnetic, field
effect, charge transfer, hall technology, and/or high frequency.
Thus, it is one object to the method of manufacturing of a warmer
drawer to provide an interactive and useful touch screen that may
respond to the user input by displaying one or more input
element(s)
[0035] These and other aspects and objects of the present invention
will be better appreciated and understood when considered in
conjunction with the following description and the accompanying
drawings. It should be understood, however, that the following
description, while indicating preferred embodiments of the present
invention, is given by way of illustration and not of limitation.
Many changes and modifications may be made within the scope of the
present invention without departing from the spirit thereof, and
the invention includes all such modifications.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] The drawings illustrate the best mode currently contemplated
of practicing the present invention.
[0037] In the drawings:
[0038] FIG. 1 is a perspective view of one embodiment of the warmer
drawer of the present invention;
[0039] FIG. 2 is a fragmentary enlarged view of a portion of the
warmer drawer of FIG. 1;
[0040] FIG. 3 is fragmentary enlarged view of another portion of
the warmer drawer of FIG. 1;
[0041] FIG. 4 is fragmentary enlarged view of another portion of
the warmer drawer of FIG. 1;
[0042] FIG. 5 is fragmentary enlarged view of another portion of
the warmer drawer of FIG. 1;
[0043] FIG. 6 is fragmentary enlarged view of another portion of
the warmer drawer of FIG. 1;
[0044] FIG. 7 is an exploded view of the warmer drawer of FIG. 1
with sections removed to show flow;
[0045] FIG. 8 is a sectional plan view taken along the lines of
8-8;
[0046] FIG. 9 is a fragmentary enlarged view of the area along
9-9;
[0047] FIG. 10 is a perspective view of a second embodiment of the
warmer drawer of the present invention;
[0048] FIG. 11 is a sectional plan view taken along the lines of
10-10;
[0049] FIG. 12 is a schematic of an electronic control circuit for
use with the present invention; and
[0050] FIG. 13 is a schematic of another electronic control circuit
for use with the present invention.
[0051] FIG. 14 is a side elevation view of an exemplary embodiment
of a warming appliance including an electronic controller to
control the temperature, humidity, power and other user defined
parameters shown with a drawer extended from an enclosure.
[0052] FIG. 15 is a top plan view of a warming appliance according
to the embodiment of FIG. 14.
[0053] FIG. 16 is an illustration of an exemplary embodiment of a
heating apparatus in a warming appliance.
[0054] FIG. 17 is a side elevation view of a warming appliance with
a drawer in a closed position and illustrating an exemplary
embodiment of a user interface, power circuit, and an electronic
control device.
[0055] FIG. 18 is a block diagram of an exemplary embodiment of a
power circuit for a warming appliance having an electronic
controller and including a humidity control circuit and other
sensors.
[0056] FIG. 19 is an exemplary embodiment of a fan/heater apparatus
for use with a warming apparatus.
[0057] FIG. 20 is an alternative exemplary embodiment of a
fan/heater apparatus for use with a warming apparatus.
[0058] FIG. 21 is a schematic diagram of an exemplary embodiment of
an electronic control circuit for a warming appliance.
[0059] FIG. 22 is a schematic diagram of an exemplary embodiment of
a power circuit for a warming appliance, including a temperature
sensor and circuit.
[0060] FIGS. 23A-23B are elevation views of an exemplary embodiment
of a warming appliance, including a venting system illustrating
proportional venting to control heat and air flow in the warming
appliance.
[0061] FIG. 24 is an illustration of a venting system for a warming
appliance with an actuator to selectively operate the vent to
control heat and air flow according to an exemplary embodiment.
[0062] FIG. 25 is an illustration of a venting system for a warming
appliance with another actuator to selectively operate the vent to
control heat and air flow according to another exemplary
embodiment.
[0063] FIG. 26 is an illustration of a venting system for a warming
appliance with a further actuator to selectively operate the vent
to control heat and air flow according to a further exemplary
embodiment.
[0064] FIG. 27 is a perspective illustration of an appliance
configured to exchange a storage drawer (shown as the left device)
for an exemplary embodiment of a warming apparatus (shown as the
right device).
[0065] FIG. 28 is an illustration of possible locations of a
warming apparatus in relation to another appliance (shown for
example as a stove).
[0066] FIG. 29 is a side sectional view of an exemplary embodiment
of a free standing warming apparatus mounted on wheels for
mobility.
[0067] FIG. 30 is a perspective view of an exemplary multi-use
warming apparatus configured to couple to a stand structure which
can be movable, as facilitated by several alternative devices.
[0068] FIG. 31 is a sectional view of an exemplary embodiment of a
warming appliance illustrating several locations of light fixtures
mounted in the chamber.
[0069] FIG. 32 is a detailed view of a mechanical door switch for
operating the light fixtures of the warming apparatus illustrated
in FIG. 31.
[0070] FIG. 33 is a detailed view of an electronic door switch
activated with a magnet for operating the light fixtures of the
warming apparatus illustrated in FIG. 31.
[0071] FIG. 34 is a partial perspective view of an exemplary
embodiment of a face plate of a warming apparatus including an
"on/off" type user interface.
[0072] FIGS. 35A-35E are illustrations of exemplary embodiments of
a user interface for a warming apparatus.
[0073] FIG. 36 is a perspective view of an exemplary embodiment of
a multi-use warming apparatus associated with another appliance
(shown for example as a cook top) and controllable remotely with a
remote control unit.
[0074] FIG. 37 is a perspective view of an exemplary embodiment of
a multi-use warming apparatus having a removable remote control
unit coupled to the face plate of the warming apparatus.
[0075] FIGS. 38 and 39 are detailed views of an exemplary
embodiment of a coupling method of the user interface to the
warming apparatus illustrated in FIG. 37.
[0076] FIG. 40 is a sectional side view of an exemplary embodiment
of a warming apparatus coupled to a remote heater/blower.
[0077] FIG. 41 is a partial perspective view of an exemplary
embodiment of a warming apparatus illustrating alternative venting
from the chamber (arrows depict an exemplary air flow pattern).
[0078] FIG. 42 is a side view of the venting illustrated in FIG.
41.
[0079] FIG. 43 is a partial side sectional view of an exemplary
embodiment of a warming apparatus including a depository for a
fragrant substance in gaseous communication with the drawer of the
appliance.
[0080] FIG. 44 is a side sectional view of an exemplary embodiment
of a multi-use warming apparatus, including a powered drawer.
[0081] FIG. 45 is a detailed view of an exemplary embodiment of the
warming apparatus with a powered drawer illustrated in FIG. 44.
[0082] FIGS. 46 and 47 are alternative embodiments of a warming
apparatus illustrating coupling and motion of a door (or panel) for
accessing a chamber of the warming apparatus.
[0083] FIGS. 48 and 49A-49E are schematic views of a movable
display device and user interface according to an exemplary
embodiment.
[0084] In describing the preferred embodiment of the invention that
is illustrated in the drawings, specific terminology will be
resorted to for the sake of clarity. However, it is not intended
that the invention be limited to the specific terms so selected and
it is to be understood that each specific term includes all
technical equivalents that operate in a similar manner to
accomplish a similar purpose. For example, the word "connected,"
"attached," "coupled," and "mounted" and variations thereof herein
are used broadly and encompass direct and indirect connections,
attachments, couplings, and mountings. In addition, the terms
"connected," "coupled," etc. and variations thereof are not
restricted to physical or mechanical connections, couplings, etc.
Such "connection" is recognized as being equivalent by those
skilled in the art.
[0085] Further, before any embodiments of the invention are
explained in detail, it is to be understood that the invention is
capable of other embodiments and of being practiced or of being
carried out in various ways. Further, the use of "including",
"comprising", "at least one of", or "having" and variations thereof
herein are meant to encompass the items listed thereafter and
equivalents thereof as well as additional items.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0086] The present invention and the various features and
advantageous details thereof are explained more fully with
reference to the non-limiting embodiments described in detail in
the following description.
1. System Overview
[0087] The present invention is preferably an appliance or device,
for example, including an electronically controlled warmer having
an enclosure with sides, e.g., a top, bottom, front, back, left and
right walls, a chamber, drawer, door, user interface, faceplate, at
least one heating element, a venting system, fan, sensor or
detection system, electronic control system, and environmental
seals.
[0088] As described herein, the warmer or warming drawer preferably
comprises a heating element such as an electric PTC (Positive
Temperature Coefficient) ceramic heater. However, more than one
heating element may be used. Alternatively, other heating elements
may replace or be used in conjunction with the PTC ceramic heater
in the warmer drawer. Other potential heating elements that may be
used include: convection heaters, calrods, wire heating elements,
heat plates, glass film, thermal ceramic heaters, flexible heaters,
lights, infrared, inductive, electromagnetic, and radio frequency
devices, heat pumps, warming liquids, heat exchangers, axial fan
heaters, sonic heaters, and gas and solid fuel products.
Electronically controlled heating methods such as radiant,
infrared, conduction, inductive, convection, resistance and
microwave methods may also be used.
[0089] A user interface is provided on the warmer drawer for
control by the user. As further described below, the interface may
include an electronic touch panel designed to control the heating
elements. Alternatively, knobs, slides, or switches may be used.
The user interface can be, for example, piezoelectric, capacitance,
tactile (membrane switches), resistance type, padless touch soft
switch technology, padless touch digital encoder, infrared
frequency dependent, magnetic switches, field effect, charge
transfer, Hall Effect, micro encoder, infrared, high frequency,
inductive computer key board, computer screen, sound, radio
frequency, or induction touch panel (keypad) for use by the
operator. Such controls can be installed on the warmer flush,
recessed, or raised and coupled. Electronic controls can be placed
on any surface so as to accommodate any design for matching other
products.
[0090] In the embodiment shown, the controls are recessed within a
faceplate located on the warming drawer enclosure to permit a door
to be closed flush with the faceplate. Such a control, e.g.,
electronic touch panel, may be made of glass, metal or plastic with
selection of the operating function(s) made by touching the surface
of the glass, metal, plastic or of other substrates to operate the
warming apparatus. The panel may also have membrane, tactile,
resistance, and/or capacitance switches with decorative overlays,
labels, and trim. Touch control keypad panels can be installed
flush, raised, recessed, or remotely on any plane with the use of
electronics. Remote control can be by wire or by wireless means so
that the electronic controls may be placed on any surface to
accommodate any design or for matching other products. Any of these
types of user interfaces may be fitted with decorative overlays,
labels, and trim so as to interface with the user.
[0091] The use of electronics is disclosed herein. For example,
these include micro-controllers, microprocessors, integrated
circuits and drivers, PC Boards, processors, and power circuits may
be used to better control functions, operations, and temperatures
and may be factory preset so as to limit the user to simple on and
off operation of the unit. The overall size, design, look, and feel
of the warmer can be matched to the size, design, look, and feel of
any appliances associated with the warmer.
[0092] Electronic controls are generally sealed better than
mechanical controls, and therefore electronic controls are less
susceptible to degradation when exposed to the elements.
Electronics also reduce the unit size so that the inventive warmer
may now be used in a number of places where present units
cannot.
[0093] The electronic controls described herein may be configured
to allow for timed on/off control based on one or more sensors or
controls such as temperature, moisture control, electronic sensors,
programmable/selectable set point(s), programmable/selectable set
time(s), programmable/selectable set operation(s), and
programmable/selectable set temperature(s).
[0094] The use of electronics provides for better control and
offers more operations than can be had in a mechanically controlled
device. The warmer may also be configured with factory preset
operations, functions, and temperatures.
[0095] The warmer drawer preferably includes an electronic control
system operably coupled with the user interface and the heating
element. The electronic control system preferably will control the
heating element in response to a signal from the user interface so
that the operator may be able to maintain the appropriate
temperature within the chamber.
[0096] The electronic control system described herein is designed
to better regulate the electrical current supplied to the heating
element. By improving the accuracy of the current supplied to the
heating element, control of the heat output to the chamber is
improved, and thus the accuracy of the temperature in the chamber
is also improved. By improving the accuracy of the temperature
within the chamber, the quality of, for example, food items in the
warmer is also improved. PTC sensor technology is one method for
controlling or regulating the current supplied to the heating
element. PTC technology provides better control over the current
supplied to the heating element and thus greatly reduces the need
to continuously cycle power on and off to regulate temperature. As
such, temperature over and undershoots are greatly reduced, and the
time required to heat the chamber to the proper temperature is also
reduced. PTC technology is but one method of controlling the
current supplied to the heating element, and it should be noted
that other methods are contemplated.
[0097] The electronic controls may also be coupled by a system that
protects the electronic controls in the case of a malfunction. One
example of such a system is the watchdog timer, which is a timer
counting cycles of a separate on-chip 128 kHz oscillator. The
watchdog gives a system reset when the counter reaches a given
time-out value. In normal operation mode, it is required that the
system uses the Watchdog Timer Restart ("WDR") instruction to
restart the counter before the time-out value is reached. If the
system doesn't restart the counter, a system reset will be issued.
The system reset from the watchdog gives a reset when the timer
expires and is used to prevent system hang-up in case of runaway
code or other malfunction preventing program operation. The reset
condition reinitializes the system hardware and software from the
beginning. Inputs and outputs are default inputs (high-impedance)
after reset, until configured by the same program that is
periodically restarting the watchdog. This prevents outputs from
driving off-chip circuitry under persistent conditions causing
reset from the watchdog.
[0098] A fan is also disclosed herein. In general, the fan is for
circulating heated air throughout the upper and lower chamber and
controlling humidity build-up. The fan may be used with or without
a heating element attached to it. It can be secured to the inside
of the upper chamber or remotely located but in fluid communication
with the warmer. The fan may preferably be used to circulate air to
provide better heat control and response time. By circulating air,
hot spots or stratified layers of varying temperature within the
chamber are eliminated. Improvements to the cavity temperature help
to eliminate the temperature swings inside the chamber, thus
providing better control and eliminating the need for user control.
The fan may be a fixed or variable speed fan.
[0099] A motorized, electromagnetic, solenoid, powered or
non-powered venting system may also be provided. The venting system
is preferably configured to optimally control the temperature,
humidity, and airflow of the chamber. Sensors or a system of sensor
may be utilized to determine the humidity or temperature in the
chamber and to send a signal to the venting system's electronic
control system reporting the sensed humidity or temperature. The
venting system, in response to a signal from the electronic control
system, may open or close the vents to regulate the conditions
within the chamber. The venting system may further comprise
mechanical louvers, slots, apertures, closures, or holes for
controlling the moisture in the chamber. The venting may be located
in the back, bottom, ceiling, walls, or front faceplate.
[0100] The sealing means may also include gaskets, adhesive tape,
double sided tape, RTV, glues, epoxies, silicon gels, foam, rubber
shapes, and other materials. Welding may also be used to seal the
warmer. The device preferably has at least one weather-tight seal
between the door and the frame preventing environmental
contaminants from entering the chamber and/or damaging any of the
electronics located within the device. Seals may be located
anywhere else on the device where there may be gaps present that
would allow fluids or other environmental contaminants from
entering the chamber.
[0101] Additionally, sealing of the electronic components and user
interface is accomplished with coatings, for example, that cover
the electronics, electronic boards, and or other components.
[0102] One or more sensors for the warmer are also described. These
may be used to sense various environmental conditions. In one
embodiment, a sensor scans the warmer for an item placed therein.
It may also provide feedback to the device's electronic control
system to operate a fan. Sensors for the appliance may be also used
to detect at least one of airflow, smoke, temperature, speed,
power, resistance, voltage, programmed operations, and set points.
The use of sensors and sensor systems will allow for more control
over the environment inside the chamber, thus regulating and
maintaining proper temperature and humidity levels. Maintaining
proper temperatures can prevent food objects placed in the warmer
from drying out. Additionally, non-food items placed in the drawer,
such as towels, can benefit from being stored at the proper
temperature and humidity levels.
[0103] In one embodiment, a scanning infrared detection system
could be placed in the upper chamber of the warmer to detect the
temperature of the contents of the chamber. In one embodiment,
thermopile (pyrometry) and thermopile infrared sensors are used.
Various other sensors could be used, but are not limited to, those
such as a thermostat, thermal disk, thermal protector, thermal
cutoff, electronic temperature controller/sensors,
electronic/mechanical AC or DC sensor/control devices, temperature
sensors, thermal switch, thermal couples, bulb and capillary,
electronic controls, bimetallic, pressure switches, creed action
thermostats, resistance temperature detectors, controllers, manual
resets, automatic resets, disc thermostat, snap action switch,
negative temperature coefficient of resistance thermistors, and
power positive temperature coefficient of resistance
thermistors.
[0104] The warmer described herein preferably has a movable drawer
assembly that can be constructed in a number of different ways. For
example, the drawer can use guide members coupled to the chamber of
the device for retracting and extending the drawer. The guide
members are connected to a movable frame that facilitates the
retraction and extension of the drawer. Alternatively, one could
use slides, glides, formed grooves, rollers, ball bearings, bearing
pads, or other methods of guiding the drawer into the chamber. In
another embodiment, the drawer can be directly coupled to the guide
members without the use of movable frame. In this embodiment, the
drawer is simply placed in and out of the warmer by mounting the
drawer assembly on opposed angle slides. The drawer may be operated
with a control and powered drive or may be manually operated.
[0105] The enclosure described herein preferably comprises a frame,
front, back and two side vertical panels, an upper panel and a
bottom panel. The drawer assembly comprises a frame having a back
panel, bottom panel, front faceplate panel and a plurality of towel
bars mounted to the back panel and front faceplate.
[0106] The front faceplate panel can be constructed so as to match
the surrounding appliances or cabinetry. The door front is
preferably designed to channel any fluids or other environmental
contaminants away from the device. In the preferred embodiment, a
positive lock closure helps hold the drawer assembly to the
enclosure.
[0107] The device is preferably made with high-heat construction so
that it can safely be installed into or along side cabinets or
walls constructed of wood or other materials susceptible to
degradation when coming into contact with heat. The device can also
be constructed so that it is a freestanding or standalone unit not
requiring a structural frame or cabinet. Preferably, the device is
constructed of a material resistant to chemicals, high and low
temperatures, ultraviolet rays, fluids, and insects.
[0108] The device preferably consists of a warmer with a lighting
element located inside the chamber to provide illumination. The
lighting element is preferably configured to illuminate upon
opening and/or upon the turning on of a switch. The lighting
element can consist of any type of lighting device capable of
withstanding the temperatures within the chamber. Because warmers
are typically placed low to the ground, it is typically difficult
to see the objects inside the chamber. The use of the lighting
element will greatly increase the operator's ability to see inside
the chamber. This may be aided through the use of glass or
transparent doors on the front of the device.
[0109] The disclosed warmer may also be equipped with at least one
of: a colored, e.g., blue, LED power indicator, on/off rocker
switch, a LCD display, an illuminated display that can be adjusted
in color and intensity, a plasma display, a dot matrix display,
line segment display, and a vacuum fluorescent display may be used
for displaying of information such as functions, temperature,
humidity, and times.
[0110] Programmable set points, times, timers, temperatures, on/off
settings, and operations are another aspect of the present
invention. The electronic control system, through signals
preferably received from the user interface, can operate and
control the programmable settings. The use of an electronic control
system offers an advantage over a mechanical system where the user
would not be able to program such settings.
[0111] In one embodiment, the device may have a timed on/off
control so that the device is automatically turned off after a
predetermined period of time.
[0112] In another embodiment, the warmer is configured with
factory-preset times, points, operations and temperatures. In this
embodiment, the device simply comprises an on/off switch or control
and no other user interaction is necessary to operate the
warmer.
2. Detailed Description of the Preferred Embodiments
[0113] Various embodiments of the device of present invention are
shown in FIGS. 1-49E, which are described in additional detail
below. All of these embodiments are configured from the same basic
design and like reference numerals refer to like components.
[0114] Referring to FIGS. 1-7, a non-food warming appliance 10
(hereinafter also referred to as a "warmer drawer 10") is comprised
of an outer enclosure or housing 12 defining a cavity 14. The
enclosure 12 can be made of stainless steel, plastic, coated metal,
glass, ceramic or other metal or non-metal materials or combination
of such materials and can be of a decorative nature. According to
the illustrated embodiments, the chamber is not intended to be
airtight, and is provided with suitable passageways (e.g. air
inlet, air exhaust, etc.) to foster a desired air flow pattern
within the chamber.
[0115] As best seen in FIGS. 1 and 7, the warmer drawer 10 includes
frame 16, along with a top 18, sides 20, a bottom 22, and a back
24, all which comprise the outer enclosure 12. Single wall
construction of the enclosure 12, preferably out of stainless
steel, may be used in applications where the surrounding surfaces
can accommodate the heat loss. As shown in FIG. 7, a double wall
construction with an insulating material or airspace between the
walls to minimize heat loss to the external surface of the
enclosure 12 may be used.
[0116] A partition 26 divides the cavity 14 into an upper chamber
28 and a lower chamber 30. The upper chamber 28 contains a heat
source, e.g., PTC ceramic heater 31, a sensor, e.g., thermal limit
switch 32, and an air handling unit or fan, e.g., cross-flow blower
34. The ceramic heater 31 is positioned above an air inlet 35. Air
flowing into the upper chamber 28 through the inlet 35 passes
through the heater 31 when entering the chamber 28. The fan 34 is
connected to an upper chamber outlet vent 37 such that heated air
flowing through the fan 34 is directed to the lower chamber 30. The
fan 34 may alternatively be located in the lower chamber 30 or even
remotely from the warming drawer 10 and may be either a fixed or
variable speed fan. The fan 34 can be used for at least one of
removing air, mixing air, and controlling moisture in the lower
chamber 30. In another embodiment, the fan 34 is connected to and
works in combination with the heating element 31. Heater 31,
thermal limit switch 32 and fan 34 are operatively connected to
electronic controls 39.
[0117] The lower chamber 30 includes a back plate 36 having a
plurality of apertures 38 formed therein. The heated air directed
by the fan 34 is blown into a space 40 formed between the back wall
24 of the enclosure 12 and the back plate 36. The air is then
forced through the plurality of apertures, or slots, 38 by a
difference in pressure to provide a uniformly diffused airflow.
Angled support housings 42 for retractable slides 44 are also
located in the lower chamber 30. The interior dimensions of the
preferred embodiment are eighteen inches wide by seventeen and
three-eighths inches high by fifteen and one-half inch deep (18''
W.times.173/8'' H.times.151/2'' D).
[0118] The warming drawer 10 further comprises a front panel 46 and
a drawer assembly 48. The drawer assembly 48 preferably includes a
rack 49 having at least one support member, i.e., bracket, hanger
or towel bar, 52 for supporting objects thereon. Each towel bar 52
is preferably formed from a sufficiently rigid material in an
upside down "V" or triangular shape to "open up" or spread out the
objects to be warmed, e.g., towels (see FIGS. 7-9). Furthermore the
"V" shape towel bar may permit air to move freely around the
objects to be warmed and the cavity, may decrease the time to warm
the object, and may help to provide an even temperature
distribution for the object to be warmed. Preferably, the towel
bars are made of metal which may facilitate heating the portion of
the item to be warmed, e.g., a towel that is in contact with the
towel bar. The drawer assembly 48 is preferably coupled to the
enclosure 12 via movable fixtures such as slide assemblies 44 for
movement between a retracted position to warm the objects in the
lower chamber 30 and an extended position so that an operator may
access the towel bars 52. The drawer assembly 48 further comprises
a base plate 56 and a door or faceplate 58. Slots 59 are formed in
the rack 49 and aligned in fluid connection with the slots 38 in
the back plate 36. Outlet vents, e.g., slots, 60 are formed in the
front of the base plate 56 near the face plate 58 to complete the
air flow path thereby facilitating air flow over the towel bars
52.
[0119] The front panel 46 has an opening 62 formed therein to
receive the drawer assembly 48. The front panel 46 preferably
includes seals 64 between the drawer faceplate 58 and the enclosure
12. The seals 64 prevent fluids and other environmental
contaminants from entering the lower chamber 30. The opening 62 is
formed with an upper recessed lip portion 66 to receive the seals
64 and a lower recessed lip portion 68. A number of slots, or inlet
vents 70, are formed across the width of the lower lip portion 68
to draw in fresh air, though some heated air from vents 60 may also
be drawn in.
[0120] The front panel 46 may further comprise an etched logo 72
and an indicator, i.e., blue LED, 74. An electronic control panel,
e.g., on/off rocker switch 76, is provided within a small recessed
portion 79 and operatively connected to the electronic controls 39.
Alternatively, any number of electronic displays could be used,
such as an electronic touch panel that can be configured to allow a
user to select the desired heating parameters. The logo 72,
indicator 74 and switch 76 are covered by the faceplate 58 and
hidden from view when the drawer assembly 48 is closed.
[0121] As previously mentioned, the drawer assembly 48 comprises
two slide assemblies 44 to move the drawer assembly 48 between a
retracted and an extended position. A friction lock closure 78 is
located on the lower lip portion 68 to latch with a corresponding
closure (not shown) to hold the drawer assembly 48 closed.
[0122] In operation, the drawer assembly 48 is opened to reveal the
support members, i.e., towel bars 52. Non-food objects, preferably
textile fabrics including towels 80, are draped over the bars 52
and the warming drawer 10 is turned on via rocker switch 76. The
drawer assembly 48 is then closed, i.e., returned to the lower
chamber 30. The heater 31 is turned on and automatically begins
heating the air in the warming drawer 10. The fan 34 turns on and
begins to circulate warmed air from the upper chamber 28 to the
lower chamber 30. Warmed air flows through the lower chamber 30 and
circulates about the towels 80.
[0123] The majority of air is drawn in from the front of the warmer
10 under the moveable drawer assembly 48 through the inlet vents 70
located in the lower lip 68 of the enclosure front panel 46. The
air is pulled into a space 33 created from the double wall
construction of the warmer 10. A small slot (not shown) between the
lower chamber 30 and the space 33 permits an additional, though
limited, amount of heated air to flow into the space 33. The mixed
air travels up the sides of the warmer 10 through the space 33. The
air is pulled into the upper chamber 28, through the heater 31 and
into the blower fan 34.
[0124] The heated air is then directed back into the lower chamber
30 via the space 40 and through the slots 38 in the back plate 36
and finally into the drawer assembly 48 via slots 59. Due to the
opening and spreading of the towels 80 from the towel bars 52, a
greater surface area of the towels 80 is exposed and heated by the
heated air. After passing through and around the towels 80, the
majority of the heated air is vented through the vents 60 in the
base plate 56. Some of the heated air is vented through the slot
(not shown) and into the space 33 as previously discussed. After a
period of time has passed, the door 58 is opened and the drawer
assembly 48 is pulled out from the lower chamber 30 via the slide
assemblies 44 with warmed towels 80.
[0125] Referring now to FIGS. 10-11, a slightly different
embodiment of the present invention is shown. As seen in FIG. 10,
the warming drawer 110 also includes an enclosure 112 and a drawer
assembly 148. The preferred interior dimensions of this embodiment
are eighteen inches wide, thirty-five and three-eighths inches high
by fifteen and one-half inches deep (18'' W.times.353/8''
H.times.151/2'' D).
[0126] FIGS. 12-13 show examples of control circuits that may be
used with the present invention. These are only examples of
preferred control circuits, and the control circuit of the present
invention is not limited to those disclosed in FIGS. 12 and 13.
[0127] The warming drawer 10 may be installed at any suitable
location, e.g., a cabinet or a support platform. It is preferred
that the warming drawer 10 be secured at the desired location to
prevent the warming drawer 10 from tilting or even falling over
when the door is opened. For example, an anti-tip brace could be
installed to prevent the warming drawer 10 from tipping forward
when it is opened and loaded.
[0128] For installation into a cabinet, the following method may be
used. First, an installer may position the warming drawer 10 in
front of the space into which the warming drawer 10 is to be
inserted. Second, the installer may plug the power cord into the
desired outlet, ensuring that any excess cord length is positioned
so that the warming drawer 10 will not pinch, kink, score or cut
the cord when the warming drawer 10 is inserted into the opening.
Third, the installer may slide the warming drawer 10 into the space
until the face plate of the warming drawer 10 is flush to the
surface of the cabinet. At this time, the installer may check the
warming drawer 10 to ensure that it is level within the space.
Finally, fasteners, e.g., screws, may be used to secure the warming
drawer 10 within the cabinet. A wood plank or decorative plate may
be used to cover the drawer front. This allows the drawer to better
fit into the surrounding environment.
[0129] After the warming drawer 10 has been installed, it may be
operated as follows. First, the operator may open the drawer of the
warming drawer 10. Second, the operator may place the desired
items, e.g., towels, into the warming drawer 10. Third, the
operator may push the on/off switch to turn on the warming drawer
10, which will then begin to heat the desired items, e.g., towels.
After the desired items have been warmed, the operator may then
open the drawer and remove the desired items, e.g., towels, from
the warming drawer 10. The operator may then press the on/off
switch to turn off the warming drawer 10.
[0130] Turning now generally to FIGS. 14-49E, according to the
illustrated embodiments there is disclosed a warming apparatus
(shown and described as a warmer drawer 112) controlled by an
electronic control system to provide improved chamber temperature
control, rapid heat-up, improved temperature set point
repeatability and minimal temperature variation from a desired set
point. The electronic control system of the warmer drawer is shown
to interface with (among others) a detection system having various
sensors (e.g., temperature, humidity, infrared, scanners,
electrical current, microwave, etc.), a heating element(s), a
ventilation system, a display device and a user interface to enable
a wide variety of desirable and advantageous features. For example,
the warmer drawer is shown as a modular device that is adaptable
for use in a wide variety of locations and environments and with
other appliances, fixtures or structures. The warmer drawer (when
in use) is intended to use a continuously adjustable amount of
power in a heating element to maintain a more precise control of
temperature within the chamber (rather than conventional and
less-precise "on-off" type devices, however, the electronic control
system could be configured for use with conventional heating
elements and sensors to reduce swings in temperature). The warmer
drawer is also shown to include a ventilation system that may be
actuated by various technologies to regulate the flow of air, heat
and/or moisture throughout the chamber. The ventilation system may
include a heating element and/or fan within the chamber, or a
heating element and/or fan may be located remotely from the warming
drawer and fluidly interconnected by a suitable passage or duct.
The warmer drawer is also shown to include a display device
configured to display information to a user related to operation,
temperature, functions, times or other control parameters for the
warmer drawer. The display device is configured to display text
(stationary or scrolling) and graphic images or illustrations. The
warmer drawer is also shown to include a user interface (locally
controlled and/or remote-controlled) to facilitate operation (e.g.
selection of inputs, setting changes, start, stop, hold, etc.) of
the warmer device by a user. The warmer drawer is further shown to
have a temperature-controlled internal chamber that is accessible
by access through a door or panel (e.g. "reach-in" etc.) or by a
movable portion (e.g. movable holder, extendable portion tray,
panel, drawer, etc. configured to hold objects within the
temperature controlled environment of the chamber) that is
extendable from, and retractable to, the chamber (in a
manually-operated or power-operated manner). The warmer drawer is
also capable of use in attaining and maintaining a desired
temperature(s) for a wide variety of objects including foods (and
other non-food items (e.g. plates, towels, etc.). The warming
drawer as shown and described may also be constructed as a
multi-use drawer (e.g. for warming, drying, baking, boiling,
steaming, roasting, etc. and also for cooling). The ability to
combine a warmer drawer with an appliance such as range, a
mini-oven, a toaster oven, a steam drawer, a baking drawer, a
boiling oven, a broiling oven, and a microwave oven thus reducing
the space required and the ability to multi task from one
appliance. This ability to combine a warmer drawer with an
appliance or an appliance combined with a warmer drawer provides
the user with advantages in space, reduce energy usage, and time
savings. Accordingly, all such features are within the scope of
this disclosure. However, this description is not intended to be
limiting and any variations of the subject matter shown and
described may be made by those of ordinary skill in the art and are
intended to be within the scope of this disclosure.
[0131] FIGS. 14-17 illustrate an exemplary embodiment of a warming
apparatus shown as a warmer drawer 112 that includes a cabinet 114
(e.g. case, box, enclosure, etc.) having walls, a top, and a bottom
that define a chamber 116 (e.g. cavity, compartment, etc.) within
the inside of the cabinet 114. The cabinet also includes an
external shroud (e.g. the wrapper bottom/back) surrounding the
walls, top and bottom to define the outer surface of the cabinet.
Air or insulation is provided within the space between outer
surface of the cabinet and the chamber wall inside the cabinet and
is intended to provide improved heat loss control when using such a
two-wall type construction. The use of only an inner chamber can be
used as long as the surrounding surfaces are configured to
withstand or accommodate the heat loss. The inner chamber is
composed of a chamber bottom and sides, chamber top and sides make
up the full inner chamber. A face plate (e.g. panel, door, etc.)
provides the connection for the inner chamber and the outer surface
of the cabinet to the front of the warmer drawer. Note here that
there are many ways to construct a cabinet for a warmer drawer,
which may include any number of layers from the inside chamber wall
to the outside surface. This writing describes only two of the many
ways for construction of a warmer drawer, but is intended to
include all such constructions. According to other embodiments, the
warmer drawer may consist of multiple warming cavities or
compartments in the same appliance. Further, the chamber can be
expanded and configured for quantity of items or containment of
specific items. For example, the cabinet 114 can be expanded
horizontally or vertically, also the warmer drawer may have various
mounting locations in relation to another appliance (see FIG. 28
for example).
[0132] The warmer drawer 112 is also shown to include a heating
system 120. The heating system is shown to include one or more
heating elements 122 within the chamber 116 (shown for example as
one heating element 122 within the chamber 116 in FIG. 16). The
heating system 120 may also comprise one or more heating elements
124 in connection with the ventilation system 130 where the heating
element(s) 124 are shown integrated with an airflow device (e.g.
fan 132, etc.) located within the chamber 116 or external to the
chamber 116 (see FIGS. 18, 19 and 40 for example). The heating
element 122 is shown schematically in FIG. 16 as a cal rod (i.e.
sheathed heating element) design that is used presently in many
conventional warmer drawers. However, there are a number of
alternative heating elements or technologies that can replace or
supplement a standard, single cal rod type heating element. For
example, such heating elements include (but are not limited to)
convection heater(s); axial fan heaters, (having an integrated
heating element and a fan); wire heating element(s); heat plate(s);
thermal ceramic heater(s); flexible heater(s) which are also called
thin film heating elements. The flexible heaters can be formed and
bent into any shape. Other heating elements include: light(s);
inductive heater; heat pump type which can provide heating and
cooling (for applications involving a heating apparatus that can
also provide cooling); warming liquids; sonic; heat exchanger,
electromagnetic energy such as infrared heaters, radio frequency,
gas, solid fuel products and microwave. These heating elements can
be placed not only on the bottom of the chamber (as shown for
example in FIG. 16) but also on the walls, on the top, front, and
in the back of a warmer drawer or any combination of surfaces.
Using these heating elements are intended to improve the heat
control and accuracy of the temperature achieving even temperatures
throughout the inside cavity. According to alternative embodiments,
the use of two cal rods (or other suitable heating elements) can be
used to improve upon the temperature(s) within a cavity and to
further reduce pre-heat/start-up times. The use of electronic(s)
and different heating elements can greatly improve on the start-up
times reaching set temperatures faster. Likewise, pre-heat times,
to stabilize the temperature inside the cavity, are reduced with
the use of a heater or heaters listed above. Greater control means
less over and under shoots resulting in better temperature holding
capability. Greater versatility can be obtained with the use of
electronic control and the different types of heating elements.
According to other alternative embodiments, the heating elements
may be configured to provide other thermal functions within the
chamber (in addition to warming) such as baking, broiling, boiling,
steaming, roasting, rotisserie, etc. and may include other suitable
heating elements such as a microwave heating element, infrared
heaters, etc. According to another alternative embodiment, a
heating element may be made from a thermoceramic conductive coating
having a geometric heat radiating pattern formed thereon to suit
the particular geometry of the chamber.
[0133] The ability to better regulate the electrical current to the
heating elements 122, 124 such that the power output can be
increased or reduced with improved accuracy, and similarly
increasing or decreasing the heat output to the chamber 116 with
greater accuracy is achievable with electronic control. An
electronic control system 140 for a warmer drawer 112 is shown, for
example, in FIGS. 18, 21 and 22 and is intended for operation with
AC or DC power supplies and is configured to regulate the amount of
electrical power (e.g. current and/or voltage, etc.) to the heating
elements 122, 124, and to control the speed of a variable speed fan
132, 134 and the position of a damper 136 (which may all be located
at the warmer drawer or remotely from the warmer drawer) in the
ventilation system, based upon input signals received from a
detection system 150 variety of sensors located at suitable
locations within (or external to) the chamber 116 (shown for
example as a temperature sensor 152, a humidity sensor 154, an IR
sensor 156, etc.). The electronic control system is also shown to
interface with a display device 160 for presenting information to a
user that is representative of the operation, temperature, time,
function, performance or other suitable parameters of the warmer
drawer or its constituent components. The electronic control system
140 is also shown to interact with a user interface 170 (which may
be remotely controlled or locally controlled) that is intended to
permit a user to directly input (or change existing inputs) such as
time, temperature, etc.). Accordingly, the electronic control
system 140 is intended to enable a wide variety of new
features/functions for the warmer drawer 112 and to provide an
improvement over conventional products that cycle electrical
current off and on (i.e. which have the elements provide full heat
power "on" and then complete heat power "off" in attempt to reach
and maintain a desired temperature. The electronically controlled
warmer drawer 112 can determine the needed heat load for the
chamber 116 (e.g. based on settings established by a user at the
user interface 170 and/or input signals received from suitable
sensors) and supply only that amount of heat, thereby minimizing
over shoots with quick warm-ups and regulation of electricity and
heat when approaching and attaining the desired set point.
[0134] According to an exemplary embodiment, the electronic control
system 140 includes a positive temperature coefficient of
resistance (PTC) current/voltage controller for controlling the
heat and power requirements and providing rapid response during
start-up. This PTC controller allows current to the heating
element(s) 122, 124 and as temperature gets close to the upper
limit, the PTC device limits the current to the heating element,
stopping the rapid rate of heat/temperature increase in the chamber
116, thus preventing overshoot. PTC thermistors (thermally
sensitive resistors) are solid state, electronic devices, which
detect thermal environmental changes for use in temperature
measurement, control and compensation circuitry and exhibit an
increase in electrical resistance when subjected to an increase in
body temperature. PTC devices remain in their low resistance state
at all temperatures below the temperature corresponding to the
desired set point. When the temperature corresponding to the
desired set point is reached or exceeded, the PTC exhibits a rapid
increase in resistance thereby quickly limiting current to the
heating element circuitry to minimize temperature overshoot. Once
the temperature within the chamber decreases to a normal operating
level, the device resets to its low resistance state providing full
load current to the heating element. The dramatic rise in
resistance of a PTC Thermistor at the transition temperature tends
to makes it an attractive candidate for current limiting
applications. For currents below the limiting current, the power
being generated in the unit is not sufficient to heat the PTC to
its transition temperatures. However, when abnormally high fault
currents flow, the resistance of the PTC increases at such a rapid
rate that any increase in power dissipation results in a reduction
in current. These devices have a resistance temperature
characteristic that exhibits a very small negative temperature
coefficient until the device reaches a critical temperature for the
upper limit or set point of the warmer drawer, which is referred to
as the "curie", switch, or transition temperature. As this critical
temperature is approached, the PTC device begins to exhibit a
rising positive temperature coefficient of resistance as well as a
large increase in resistance. This resistance change can be as much
as several orders of magnitude within a temperature span of a few
degrees. Thus as the cavity chamber temperature increases from an
ambient temperature, the PTC electronic device increases in surface
temperature reducing the ability to dissipate heat which results in
an increase in resistance resulting in reducing the current to the
heating element. This increase in resistance and reducing current
also slows down the heat up when coming to the set point. These
devices also do not completely stop the flow of current to the
heating element, but rather, limit the current. Thus providing and
maintaining a steady temperature by substantially eliminating
on/off swings that other conventional warmer drawers provide. This
design also provides users with cost savings; since the undesirable
"on/off cycling" with its corresponding overshoots and undershoots
is avoided, the full current draw of the heating element is also
avoided and the warming drawer uses only the required current for
start-up heating and maintaining the desired temperature. According
to other embodiments, the electronic control system includes any
one or more of a micro controller(s), micro technology, integrated
circuits, drivers, and microprocessors that may be mounted on one
or more printed circuit boards, to provide the desired
functionality of interfacing with the heating elements, the
ventilation system, the sensors, the display device, and the user
interface.
[0135] The illustrated power board and control board show one type
of electronic control (see FIGS. 18, 21 (control board) and 22
(power board)). The boards are shown as two boards, but may also be
fabricated on the same board. Knobs to interface with the
electronics can be provided, thus providing the "look" of a
mechanical product. Construction of the electronics in a warmer
drawer can use, but is not limited to, high heat construction
design, specialized adhesive construction, use of loop resistant
circuitry which is designed for use in membrane switches, special
edge seal finishing for design of key pads using membrane switches,
ESD/EMI/URI shielding, electronics, and using display technology
such as light emitting diodes, liquid crystal display, plasma, dot
matrix, vacuum fluorescent display, etc. All of these can improve
the control, display, design, look and operation of the
electronic(s).
[0136] Such embodiment providing and electronic control system as
described above is an improvement over prior art methods of cycling
power on and off in an attempt to control the heat. With the
improved method one can determine the needed heat load for the
chamber and supply only that amount of power/heat. This also can
prevent temperature over shoots by quick warm ups and when almost
reaching the fixed set point, limit the amount of energy heat
(current) when reaching the fixed set point. The ability to better
regulate the electrical current to the heating elements such that
the power output can be regulated will improve accuracy, and
similarly increase or decrease the heat output to the chamber with
greater accuracy. This innovation reduces the user's cost to
operate this product. The electronics and sensors can determine the
needed heat load for the chamber and supply only that amount of
heat to the chamber.
[0137] The warmer drawer 112 also includes a display device 160
(see FIG. 35A, shown for example as integrated with a user
interface 170) that provides the ability to display to the user the
operations, functions, temperatures, times and other features (e.g.
fan speeds, alarm controls and signals, clock displays, message
board-type displays, etc.) and may be provided in text (in any
suitable language) or with suitable images (e.g. pictures,
pictograms, graphics, animation, etc.--such as a spinning fan, an
image of a food product such as a fish, chicken, beef, etc.) using
electronics to convey information to the user for accurately
controlling operation of the warmer drawer 112 to advance the
ability to cook and hold desired temperature(s). The display device
60 may include one or more display panels 162 (such as three or
four LED display panels for providing numeric or text information
(e.g., in a stationary or "scrolling" manner, etc.)). One or more
of the display panels on the display device may also be configured
as an LCD, plasma, dot matrix, vacuum fluorescent or other suitable
type of display panels (in one or more colors and with varying
degrees of illumination to adapt to background lighting) for
conveying text, graphics or other desirable images to a user.
[0138] The warming drawer 112 also includes a user interface 170
(see FIGS. 35A-E, shown for example as integrated with a display
device 160) shown as an electronic touch control panel 172 (e.g.
touch pad, key pad, input device, etc.) according to an exemplary
embodiment. The user interface 170 may include any suitable input
elements 174 (shown by way of example in FIG. 35A as ON/OFF, ADJUST
(increase and decrease) and PRESETS: HIGH, MEDIUM, LOW, PROOF,
BAKE, BROIL; and by further way of example in FIG. 35B as POWER
ON/OFF; TIME--SELECT; TEMPERATURE--SELECT), for selection and input
of desired operations by a user, however any suitable input
elements may be used to suit a particular application. According to
any exemplary embodiment, the user interface 170 may be provided
using any suitable technology such as (but not limited to) a piezo
touch panel, or a capacitance electronic touch control panel (e.g.
made of glass, metal or plastic, etc.) with selection of the
operating function(s) made by touching the surface of the glass,
metal, or plastic to operate any size warmer drawer/multi-use
drawer could be used. In addition, tactile (membrane switches)
touch control panel switch pad(s) for a 29.99'' and smaller warmer
drawer/multi-use drawer for touch controlling the operations of a
warmer drawer could be used. Tactile (membrane switches) touch
control panel switch(s) for 30.01'' and larger warmer drawers for
touch controlling the operations of a warmer drawer could be used.
For any size warming drawer, other types of user interfaces may
include resistance type touch control keypad (whereby touching
plastic, metal, glass, etc.) at a location causes a change in an
electrical signal to be measured and the electronic control system
responds to this change). According to any exemplary embodiment,
the user interface may include use of membrane switches, piezo,
capacitance, paddles touch soft switch technology, paddles touch
digital encoder (micro-encoder), capacitive, infrared, high
frequency, magnetic, field effect, charge transfer, hall technology
resistance, and inductive. Further, the face panel of the user
interface can be fitted with decorative overlays, underlays,
labels, trim, and completed control panel assemblies. Touch control
keypad(s) panels 172 can be installed flush (see FIG. 35D), raised
(see FIG. 35E), or recessed (see FIG. 35C) for use in connection
with the electronic control system. Further, the touch control key
pad(s) 172 of the user interface 170 can be installed in any plane
of the warmer drawer 112 (or remote structure when operated by
remote control) with the use of electronics. According to an
alternative embodiment, the display device and the user interface
may be arranged as separate (yet still intercommunicating) devices
at any suitable location on the warmer drawer.
[0139] Electronic controls can be placed on any surface to
accommodate any design or for matching or simulating the look of
other products that may be associated with the warmer drawer. The
touch control keypad(s) 172 of the user interface 170 and
display(s) 162 of the display device 160 can be placed on the front
of a warmer drawer 112 to provide the user with "instant viewing"
of the operations and functions without having to open up the
warmer drawer. Touch control panels 172 can be made of metal,
plastic or glass to suit a particular application. The use of micro
controller(s), integrated circuits and drivers, PC board(s),
processor, and power, and other electronics can be used in the
electronic control system 140 to interface with the touch pads 172
of the user interface 170 to control operation of the warmer drawer
112. Any size from a small to a large warmer drawer can be fitted
for use with a touch type control pad (e.g. piezo, capacitance,
resistance, etc.). Further, any size from a small to a large warmer
drawer can be fitted for use with an induction touch control pad.
The design of the electronics can be unique or matched to the other
looks, aesthetics, appearance or decor on adjacent or cooperating
appliances or structures. The overall size, design, look and feel
of a warmer drawer can be matched to the size, design, look and
feel of any appliance or structure.
[0140] According to an exemplary embodiment, the touch control
panels 172 of the user interface 170 can be remotely controlled
having the electronics, or a portion of the electronics, located
not on the product but in a different location not on the warmer
drawer (see FIG. 36). Remote control can be by wire or by wireless
controlling the functions of a warmer drawer. The touch control
panels 172 of the user interface 170 may have graphic(s) (e.g.,
pictographs that are unique or specific to the design for the
matching product(s) or specific to the required designs and
functions, etc.). The use of electronic provides the user with
better control and offers more flexible operations than can be
obtained with a conventional mechanical control system. With this
flexibility the user can perceive (e.g., see, hear, etc.) what is
happening and can modify the function of the warmer drawer to
achieve a desired performance.
[0141] The structures for the display device 160 and the user
interface 170 control functions could be mounted to the fixed
faceplate or the movable face/door of a warmer drawer (see FIGS.
35C-35E and 37). With the display device 160 and/or user interface
170 mounted on the face panel with the warmer drawer closed,
viewing of the display device and user interface can be an
indicator of the operations inside the chamber 116. In applications
where the electronics are mounted on the face panel of the warmer
drawer 112, the electronics can be disconnected when the drawer is
pulled out thereby disconnecting functions. Disconnection can be
accomplished by wireless communication or by a wired system. Wires
of suitable length can be provided so as not to disconnect
operations and interfere with the operation of the drawer being
opened.
[0142] According to another exemplary embodiment, the display
device 160 and/or user interface 170 may be placed on any desired
surface of the warmer drawer or associated structure (e.g., to
accommodate any design for matching or simulating the look of other
products the appliance may be paired with, or to protect the
components from damage, or exposure to adverse environments, etc.).
By way of example, the display device 160 and user interface 170
may integrated (shown for example as an integrated
display/interface 179; however, the display and interface may be
kept as separate devices) and/or arranged to be "hidden" from
normal view with a panel, for example, by the closing of a sliding
panel (which may be spring-biased) or by integrating the
display/interface 179 with a rotating panel or L-shaped plate
(shown for example as a rotating drum 176 in FIGS. 49A-49E) which
may be mounted on a stationary portion 114 of the warmer drawer or
on the extendable portion 118 (e.g., movable holder, etc.) and
repositionable in a variety of orientations for ease of
viewing/operation and for concealment. This ability to conceal the
display/interface, to protect it from damage, or match other looks,
and having it independent of the moving drawer but still have a
flush looking front from two parts, or to provide a smooth looking
front is intended to enhance the functionality and options
available to a user for operation of the warmer drawer. Once the
user has completed viewing the display or operating the interface,
the user (or the warmer drawer itself) can rotate the drum to a
position to conceal the display/interface and expose a "matching"
panel 177 to provide a smooth-looking or substantially uniform
front appearance. According to one embodiment, electronic sensors
may be provided in the display/interface so that the user can touch
the front of the display/interface for movement to a storage
position or for movement to a viewing/operating position. When the
electronic sensors in the display/interface sense the "touch", the
rotation begins until reaching the stop point (e.g., at the next
"position" of the display/interface), such as the display/interface
panel provides the smooth front. Another way the display/interface
may be moved to the storage position is if the warmer drawer (or
another associated appliance) has been "off" for a predetermined
time period. Once such a predetermined time period has elapsed, the
display/interface may automatically move from the viewing/operating
position to the storage position. A drive device such as a motor or
actuator (shown, for example, as a drive motor 178 in connection
with the display/interface 179 in FIG. 48; however, other suitable
devices for rotating the display assembly can be used to provide
movement) is provided for operation of the repositionable
display/interface. Suitable devices such as switches, stepper
motor(s), magnetism, or a positive stop like metal can be used for
the location of "stop points" for locating the desired positions of
the display/interface.
[0143] According to another embodiment shown for example in FIGS.
19 and 20, the warmer drawer includes a fan 132, 134 (with or
without a heating element 124 attached to the fan, and shown as an
axial fan 132 with heating element 124 in FIG. 19 and a cross
blower 34 with heating element 124 in FIG. 20) that is secured to
the inside of the chamber or located remote but in fluid
communication with the chamber (e.g. by a duct 137 etc.--see FIG.
40 for example) to circulate the heated air and that interfaces
with the electronic control system 140 to receive its control and
electrical power. The illustrated fan configurations are intended
to provide improved heat control and response time by improving the
uniformity of the temperature within the chamber 116 and minimizing
layering, stratification or other gradients (i.e. not necessarily
for convention cooking purposes). With the slowly circulating air,
"hot spots" are substantially eliminated within the chamber 116.
Also, slow moving air generally will not adversely affect the hold
quality of the object(s) in the chamber 116, but will improve upon
it because the temperature over and under shoots are substantially
eliminated. Accordingly, chamber temperature management is also
improved by ventilation control to substantially eliminate
temperature gradients, large temperature swings and reducing
pre-heat/start-up time within the chamber. A fan or other device
for moving air (or otherwise providing air movement within the
chamber) is also intended to provide humidity control within the
chamber 116. Humidity build-up in the chamber 116 can be controlled
by providing a vent system with controlled variable size openings,
such as a powered vent system (see FIGS. 23A-26). Having a variable
speed fan/motor associated with a vent with variable size openings
for moving air in and out, and mounted inside the chamber 116 or
mounted outside the chamber 16 is intended to provide different air
flows as needed to control (e.g., increase, decrease, maintain,
etc.) moisture accumulation and/or temperature differences with the
ability of introducing fresh air in the chamber 116. A fan moving
the air can provide "mixing" and substantially prevent front to
back, side to side, or top to bottom temperature differences. The
resulting air movement by a fixed or a variable speed fan is
intended to hold a uniform temperature throughout the chamber. The
fan 132, 134 can also be used for ducting heated air or moisture
out of the chamber 116 of the drawer 112. Another aspect of this
design is the ability for the fan 132, 134 to be controlled by a
humidity sensor 154 in cooperation with the electronic control
system (see FIG. 18). This can improve the quality of the food or
non-food items being held in the chamber 116.
[0144] According to the embodiment illustrated in FIGS. 23A-23B,
the vent with variable openings includes a damper 136 or louver(s)
configured to co-act with apertures 138 (e.g., holes, slotted
openings, etc.) to provide ambient air inlet(s) or exhaust
passageways, that can be variably positioned between "opened" (as
shown in FIG. 23A) and "closed" or at a partially opened position
therebetween either manually or by an actuator 139. According to a
preferred embodiment, the vent system 130 includes a sliding damper
136 that interacts with the apertures 138 and is driven by an
actuator 139 that receives a suitable signal from the electronic
control system 140. For example, the actuator 139 may be configured
as a motor-driven drive screw (see FIG. 24), or a motor driven
slide/rack and pinion device (see FIG. 25), or a solenoid operated
device (see FIG. 26), or bimetallic device, or an electromagnetic
device, or other suitable electronically or electro-mechanically
controlled device for adjusting the position of the damper 36 in
relation to the apertures 138. The ability to control the flow of
air and moisture within the chamber 116 by an actuator 139 coupled
to a damper-vent apparatus is intended to regulate the flow of air
being exhausted from, or brought in to, the chamber 116 of the
warmer drawer 112. This controls the loss of moisture (humidity) or
the ability to hold moisture inside the chamber. The air inlet(s)
or outlet(s) can be opened immediately all the way (full open) or
closed all the way (sealed chamber) or opened to a preselected
position to control heat or moisture build-up. The size of the air
inlets/outlets through the vent apertures 138 may also be modulated
based upon a suitable signal from the electronic control system 140
(such as in response to a signal representative of a humidity level
or signal from the humidity sensor 154). With the use of a forced
air (powered) or circulating air system, even greater control can
be had with a power venting system. The damper (e.g., louver,
slide, etc.) allows for flows to be proportional thus controlling
air movement and heat. Vent apertures 138 can be located at any
suitable place such as in the front or face panel of the warmer
drawer 112, at the side top and/or at the bottom, or any other
suitable location to achieve a desired air flow pattern within the
chamber 116. The warmer drawer 112 can be configured with any
venting configuration which will permit air to leave or enter the
chamber 116. Any suitable and connected actuator 139, for example,
a motor, that can provide motion, which can be transformed into
movement for closing or opening the vents, can be utilized. A
humidity sensor 154, including associated electronics, can detect
and provide control to the vent fan 132,134, and heater 122, 124.
Such device can also be configured to provide user input (e.g.
through the user interface) for setting the desired humidity level
inside the chamber.
[0145] According to another embodiment the warmer drawer 112 may be
configured as a multi-use-warmer drawer that combines a mini-oven,
warmer drawer/broiling cavity, multi-use warmer drawer/steam oven,
multi-use warmer drawer/baking oven and multi-use warmer
drawer/microwave oven in any suitable combination. Combining the
warmer drawer with other heating or cooking products can reduce
space used in a kitchen (institutional, commercial, residential,
etc.). Using these warmer drawer/multi-use drawers can save
electricity and heat energy due to their small size. A large
portion of the energy consumed in cooking applications is often
associated with preparation of small amounts of food. Having to
heat up a large oven takes time and is more expensive than using a
mini-oven/warmer drawer. This mini-oven/warmer drawer could take
the place of a toaster oven saving counter space. When combined
with a broiling element within the chamber 116, additional
capabilities for cooking and providing temperature holding
capabilities may be realized that are not presently found in
conventional products. Another embodiment provides a "multiple use"
warmer drawer/mini-oven/broiling cavity. It is readily apparent
from the above description that combining the warmer drawer 112 as
described herein with other cooking equipment can be a great
benefit to a home kitchen or other food preparation or maintenance
location. It also readily apparent from the disclosure that any
desirable appliance with a warmer drawer.
[0146] According to another embodiment, a warmer drawer 112 or
multi-use drawer can be configured as a modular unit having the
ability to be adapted to "fit" into a range or other appliance(s)
without being built-in (see FIGS. 24 and 28 for example). A modular
warmer drawer 112 or multi-use drawer can be operated independently
from the other appliance with which it is associated. For example,
the lower storage drawer 182 of an oven/freestanding range 180 can
be removed and replaced with a modular unit 112 in its place to
provide cooking space and food holding capability. This warmer
drawer 112 or multi-use drawer would operate independently of the
freestanding range 180.
[0147] According to another embodiment the warmer drawer 112 is
adaptable as a warmer drawer/multi-use drawer shown for example as
a mobile pedestal heated chamber with drawers, slides, or doors for
warming, cooking and holding food and non-food applications (see
FIGS. 29-30). The warmer drawer/multi-use drawer is shown for
example as combined with a mobile pedestal 184 to provide a heated
chamber apparatus that is shown as not built into a wall,
cabinetry, structural member, immovable island or other non-mobile
structure. A warmer drawer/multi-use drawer having a heated
chamber, accessible by doors, drawers, lids, or the like is
configured to rest on the floor or on other surfaces and be
freestanding on its own. The warmer drawer/multi-use drawer or its
pedestal 184 is intended to be self-supporting and rests upon its
own structure (shown for example as footpads, foot pegs, legs,
wheels or casters, etc.). A structure attachment can be made
directly to the warmer drawer/multi-use drawer or to a mobile frame
186, upon which the warmer drawer/multi-use drawer is supported.
The structure attachment can be removed when not in use or it can
be permanently attached. The warmer drawer/multi-use drawer can be
removed and placed on any desired surface for use and then returned
to the structure attachment, or the warmer drawer/multi-use drawer
may remain coupled to its pedestal 184 and immobilized during use
(e.g. by wheel locks, chocks, etc.). The mobile frame can be made
of wood, metal, plastic, composite material or any combination of
such materials intended to provide a lightweight yet sturdy support
and transport structure. Another embodiment of the warmer
drawer/multi-use drawer can provide for use indoors or outdoors,
such as by weather-resistant features (e.g. sealed touch pads,
electronic modules, gasketed door panels, etc.).
[0148] A mobile heated warmer drawer/multi-use drawer can also be
installed into a mobile island or cart 187 to be used for cooking
and holding food (and for non-food applications as well) (see FIG.
29 for example). Such a mobile warmer drawer, island or cart can be
equipped with a cutting/work surface top made from metal, wood,
solid surface materials, or other materials. The top can be a fixed
cutting/work surface or made removable for remote
working/cleaning/serving or replacement. According to any exemplary
embodiment, the warmer drawer/multi-use drawer as shown and
described (e.g. mobile or stationary, etc.) may be used in any
desirable location for any suitable application. For example, the
warmer drawer/multi-use drawer may be used in kitchens
(institutional, commercial or residential) for food items and
non-food items, and may also be used in eating or serving areas or
devices (e.g. caterers, buffets, picnics, lunch-carts or trailers,
etc.) or may be used in other applications such as hotels, resorts,
spas, golf courses, cruise ships where it is desirable to maintain
the temperature of objects (such as food objects and non-food
objects) for the comfort or convenience of users, customers,
consumers, guests, staff, etc.
[0149] According to another embodiment, a warmer drawer/multi-use
drawer 112 is provided that is configured to be controlled by the
electronic control system 140 and equipped with an AC or DC
electronic temperature sensor 152 located inside the chamber 116
such that the temperature of the chamber 116 can be detected
accurately. Controlled by electronics and equipped with an AC or DC
electronic temperature sensor 152 provides control and operation
response, to sense temperatures in the chamber 116 and then the
electronic control system 40 provides a suitable output to control
the heating element(s) 122, 124 functions for on/off or regulated
power operation. Any electronic sensor used for detecting
temperature, resistance, or power using such devices as
thermos/thermal detection device(s) for the control of the chamber
temperature can be used with the electronic system in a warmer
drawer/multi-use drawer. The heating element is electronically
connected to a temperature-sensing device and is AC or DC powered
in accordance with requirements for the warmer drawer installation
or use location. With user selected settings (e.g. through the user
interface 170) or preset (factory or otherwise) settings of the
electronic control system 140, the signals associated with
maintaining the desired temperature(s) within the chamber 116 are
sensed and sent by the temperature-sensing device 152 within a
predetermined desired range of operating temperature(s) or set
point(s). The sensor 152 can be mounted on the electronic board or
it can be attached by itself to any wall or location in which
detection of the temperature can be made. The ability to better
detect the temperature within the chamber improves the response
time to the changes inside the chamber and improves the accuracy of
the actual temperature in the chamber when compared to the desired
set point. This quick response and control reduces the effects of
overshoot and undershoot. Any electronic, mechanical, or
electromechanical sensor can be used for detecting temperature,
resistance, or power for detection and control of the temperature
in the chamber with the use of electronics. Any electronic,
mechanical, or electromechanical, AC or DC sensor can be used for
detecting and control of temperature, resistance, or power for
better control of the chamber temperature. Such sensing or
detecting devices, which can be used include, but are not limited
to temperature sensors, thermostats, thermal, temperature controls,
thermal protectors, thermal cutoffs, thermal switch, thermocouples,
adjustable thermostats, printed circuit board thermostats,
hermetically sealed, time delay relay, bulb and capillary, cold
controls, electronic controls, bimetallic, pressure switches, creep
action thermostats, resistance temperature detectors, controllers,
manual reset, automatic reset, disc thermostat, snap action switch,
negative temperature coefficient of resistance thermistors, power
positive temperature coefficient of resistance thermistors that can
be controlled by electronics, or other suitable device. The sensing
devices, along with the electronic control system is intended to
provide better temperature control of objects within the chamber
and ultimately, improved user satisfaction.
[0150] According to another embodiment, sensing technology such as
scanner detection technology may be used to directly sense the
temperature of an object in the chamber for providing a signal to
the electronic control system for controlling the power and heat
from the heating element and/or controlling operation of the
ventilation system 130. A warmer drawer 112 can have the ability to
detect objects placed inside the chamber 116 and then set
temperature(s) for maintaining required temperature. For example,
in a warmer drawer with item detection on a target surface, an IR
sensor 156 collects a small amount of energy (usually 0.0001 watt)
radiated from the target, generates an electrical signal that is
amplified by a precision amplifier and converted into voltage
output. A CPU digitizes the signal by an Analog-to-Digital
Converter, an Arithmetic Unit solves a temperature equation based
on Planck's Radiation Law, compensates for the ambient temperature
and emissivity resulting in a temperature reading within a fraction
of a second after user places the item in the field. Using this
technology one can measure the temperature of an item or cover the
complete surface from a five (5) meter distance as long as the
Field of View is filled by the target. Also, many IR sensors
measure in the 8 um to 15 um wavelength band where the atmosphere
is almost totally transparent. IR sensors can operate in complete
darkness. In the 8 um to 15 um wavelength band, IR can penetrate PE
film (for example: a plastic trash bag or saran wrap). The IR
thermometer sensor 156 can detect the presence of the object.
[0151] IR sensing can measure objects that move, rotate, or vibrate
(e.g., web process or any moving process). They are understood not
to damage or contaminate the surface of the object of interest.
They measure the temperature of the actual product being used in a
warmer drawer and not some of the other parts of the surfaces.
Thermal conductivity of the object being measured such as glass,
metal, wood or even very thin objects does not present a problem,
as is the case with certain other sensors. Response time is
typically in the millisecond range, which gives the user more
information per time period. The IR detector system can be used for
heat/fire and/or distance in the warmer drawer. The use of thermal
sensing technology such as RTDs (resistance temperature detectors),
integrated circuit sensors (IC), thermistors, IR thermometers,
bimetallic, and thermocouples can also be used. Other sensors like
photoelectric, photon, optics, indium-gallium-arsenide, and thermal
detector could be used in place of IR for the detection of items
placed on the surface.
[0152] Another embodiment provides a warmer drawer/multi-use drawer
configured for outdoor locations having the ability to weather
typical outdoor temperatures and environments. The use of
electronics for warmer drawer/multi-use drawer can provide better
sealing for use in these environments. With the use of remote
locations for the electronic controls when the drawer 112 is used
outdoors, the effects of the environment on the controls is
minimized. Electronics are typically not subject to mechanical
problems of "turning force" due to cold temperatures in certain
locations. They are usually resistant to environmental conditions
and problems to an extent unlike mechanical controls and switches,
which can develop rusting or dust build-up for example. The
electronic controls are also usually not subject to cleaning
problems, as are mechanical controls. Electronic controls can be
best suited for outdoor applications where extreme temperatures and
weather conditions exist, because they typically have no (or
minimal) mechanical moving parts to fail.
[0153] Another embodiment provides for the use of aromatic
materials 190 such as favoring additives, e.g. wood clips, liquid
smoke, etc.) or fragrances that can be added into a receptacle 192
within the chamber 116 to impart flavoring to food objects or
desirable fragrances to non-food objects inside the chamber of the
warmer drawer (see FIG. 43 for example). This can be accomplished
by a receptacle 192 such as a special pan in contact with the
heating element 122 or by evaporation, or flavor adding can be
accomplished by venting or ducting from a different chamber or
outside the chamber.
[0154] According to another embodiment, the chamber 16 of the
warmer drawer/multi-use drawer 112 may be illuminated when the
drawer is opened or when a switch is turned on (see FIGS. 31-34 for
example). FIG. 32 illustrates one example of a door-actuated switch
196. FIG. 33 illustrates one example of an electronic sensor 193.
FIG. 34 illustrates one example of a mechanical (e.g. rocker, etc.)
switch 198. Because the extendable and retractable drawers may be
positioned low to the ground and with a small opening, it is
sometimes hard to see inside the chamber in certain applications.
The use of a light 194 to illuminate the inside is of great help
when trying to view the food or other objects without opening the
drawer fully. The door or face panel of the cabinet can be provided
with a viewing window, and a transparent shelf or pan can also be
provided to increase visibility into the chamber.
[0155] According to another embodiment, the warmer drawer/multi-use
drawer 112 may be configured for use through the electronic control
system 140 to provide programmable set point(s), programmable set
time(s) and programmable set operation(s) as well as multiples of
set time(s), function(s), set points, operations or power on/off,
by suitable interaction with the user interface. The ability to
select multiple functions, operations and times gives the warmer
drawer/multi-use drawer advantages over non-electronic controlled
units. Timed on/off control can provide the ability to control the
on/off time of the drawer. On/off time(s) can be infinitely set
with the use of electronics. This programmability provides the
advantage of being able to enter different functions or operations
(e.g. more than one, etc.) into the electronic control system and
have the warmer drawer/multi-use drawer control all desired
functions, an advantage over mechanical or single function units.
One can have one, two or more functions, operation(s), set point(s)
with substantially limitless programming for control of these
events. For example, one may start out with one temperature, at
high temperature such as 200 degrees F for one hour and then being
able to reduce the temperature to 160 degrees F for the remaining
time. With a single function controlled warmer drawer the operator
would typically have to manually reset the temperature. An
electronically controlled warmer drawer/multi-use drawer (e.g.,
dual use drawer/triple use drawer) permits more user freedom.
[0156] A timer device, for example a clock, on the display device
can also be provided, which can be changed to permit other
programmable information to be displayed. Display illumination may
also be selectable such that if the drawer is configured to expose
the display, the display may serve as a night light or be adjusted
for ease of viewing.
[0157] Another embodiment provides a warmer drawer/multi-use drawer
112 configured with a hinged door(s) (see FIGS. 46-47 for example).
This permits the user to open the drawer by rotating or folding the
door out of the way. The door(s) can be hinged rather than fixed,
permitting the door(s) to remain in place and having the door(s)
out of the way when accessing the contents of the warmer
drawer/multi-use drawer. This also permits the user to open the
door(s) to view inside the drawer without having to pull out all or
some of the contents.
[0158] Referring to FIGS. 44-45, a warmer drawer 112 is shown
according to an exemplary embodiment having a powered extendable
portion 118 (e.g., "servant drawer"--for convenient access for
loading or removal of objects from the chamber) having the ability
to open or close by the touch of a user or by some signal device so
that a user can open or close the warmer drawer without having to
pull or push on a handle or the like through the travel range of
the extendable portion. Activation of the warmer drawer can be by
touching the drawer door, breaking a beam, interrupting a signal,
or having a feed back signal to a sensor/detect with no (or
minimal) hand held control or contact with the warmer drawer or
extendable portion. An activation system is provided to control
operation of the extendable portion by interfacing with suitable
sensors, the electronic control system 140 and a drive system 199.
According to one embodiment, an activation system is shown as a
hall sensor 195 and a magnet 197 used to determine the "stop
points" and/or "start points" for movement of the extendable
portion and initiate signals for opening and/or closing the
extendable portion 118 (note that the sensor 195 is shown on the
cabinet 114 and the sensor 195 is shown on the extendable portion
118; however, the sensor and magnet may reversed or provided on
other suitable structures). For example, when opening of the
extendable portion 118 is desired, the activation system receives
an input and initiates a drive system 199 and the sensor 195
detects the initial movement of the magnet 197 away from the sensor
195, which may provide a signal to the display system 160 to
indicate position of the extendable portion 118 and may also
initiate operation of a drive system 199 (if movement of the
extendable portion was manually initiated) to move the extendable
portion 118 from a closed position to an open position (see FIG.
44). As the extendable portion 118 approaches the open position,
another magnet (not shown) may approach the sensor 195, which then
initiates a signal (e.g. a stop point) to terminate movement of the
extendable portion. Movement of the extendable portion from the
open position to the closed position may also operate in a reverse
manner. For example, upon activation the drive system moves the
extendable portion 118 toward the closed position, which is
detected by the sensor as the (second) magnet moves away from the
sensor 195 (and initiates operation of the drive system if manually
activated) in a closing direction until sensor 195 detects the
approach of magnet 197, such that the field of the magnet detected
at the sensor indicates that the extendable portion has reached the
desired position, such as the closed position (another stop point),
which may correspond to any particular position (e.g., compression
of a gasket between the extendable portion and the cabinet, etc.).
Also, a change in resistance or other suitable indication can be
used to determine the stop points. According to the illustrated
embodiment in FIG. 44, a motor-driven drive screw system 199 is
employed to move the extendable portion 118 open and closed
(however, any suitable drive system such as a motor with a wire,
cable, pulleys, etc. can be used). According to an alternative
embodiment, a switch (or other suitable device such as light-beam
sensors, resistive or inductive touch pads, etc.) can be used to
operate the extendable portion and may be located on the unit or it
can be remotely located for ease of operation and use, and can be
operable to energize any suitable drive device for extending and
retracting the extendable portion. According to other alternative
embodiments, any suitable sensors and signals may be used to
initiate opening or closing of the extendable portion, For example,
the signal may be a sound, a voice, a noise signal (e.g. clapping
or banging, etc.) interrupting a steady state condition;
interrupting a beam of visible light or non-visible light; touching
a surface which resistance increases or decreases providing a
signal to a sensor for activation; force activation by pushing on
the door front; and by a remote control signal such as a handheld
control using a radio frequency or light beam, cooperating with
suitable sensors. These and other methods can be used to activate
the drive system for opening and closing the extendable portion 118
of the warmer drawer 112. By providing an activation system
cooperating with a drive system responsive to selected stop points
and start points, a user has the ability to actuate the extendable
portion (e.g., by touch, interruption of a signal, switch
operation, etc.), to which the warmer drawer 112 responds by
opening and providing access to the extendable portion 118 and
chamber 116 without having to manually pull or push the extendable
portion throughout its travel range to access the contents.
According to another embodiment, the activation system may detect
an increase in resistance as the motor of the drive system 199
approaches (or reaches) the stop point and provide an output signal
to stop the motor (or reverse the direction of the motor, or other
desirable control action). According to a further embodiment, a
stepper motor may be provided so that the number of turns can be
counted by the activation system to determine the stop point and
provide an appropriate output signal to control operation of the
extendable portion.
[0159] According to another embodiment, the warmer drawer 112 may
also be configured to cool (e.g. refrigerate) objects placed in the
drawer. For example, a heat pump system may be substituted for the
fan and heater (previously described). By further way of example, a
magnetic refrigeration device, or may be a thermoelectric
heating/cooling module (e.g., a Peltier-type device or module,
etc.).
[0160] According to any exemplary embodiment, a warming apparatus
such as a warmer drawer for use in stationary or mobile
applications in any desirable environment is provided with an
electronic controller that interfaces with a heating system (having
one or more heating elements within the chamber or remote from the
chamber, and that receive electrical power in a continuously
variable and regulated manner to provide precise temperature
control within a chamber), a ventilation system (including an air
flow device such as a variable speed fan/motor, and a variably
positionable louver/vent device driven by an actuator for air, heat
and/or humidity control), a user interface (locally-controlled or
remote-controlled) to permit a user to control the operation of the
warmer drawer in a simple and convenient manner, and a display
device arranged to provide information to a user in the form of
alpha-numeric text messages (stationary or scrolling) and/or
graphic images. The warmer drawer may be converted to a multi-use
drawer by providing suitable elements within the chamber (e.g., for
cooling, or for other purposes such as baking, broiling, boiling,
steaming, roasting, etc.). The warmer drawer may be installed in
any convenient arrangement such as on a mobile pedestal, or
supported by a cabinet, such as under a counter, or with a built-in
oven as more fully described in a publication entitled Warming
Drawer Installation Instructions, 803150/983-0152-000 REV C, 11/04,
commercially available from Wolf Appliance Company LLC of Madison,
Wis. The warmer drawer may also feature stainless steel
construction, ball bearing drawer glides and accessories such as
optional drawer fronts and racks for staking objects in the
chamber, and may have an automatic shut-off mode, or a preset
programming mode, and variable moisture selection operating
features as more fully described in a publication entitled Warming
Drawer Use & Care Information, 803149/983-0145-000 REV C, 1/04,
commercially available from Wolf Appliance Company LLC of Madison,
Wis.
[0161] The construction and arrangement of the elements of the
warming apparatus as shown in the illustrated and other exemplary
embodiments is illustrative only. Although only a few embodiments
of the present inventions have been described in detail in this
disclosure, those skilled in the art who review this disclosure
will readily appreciate that many modifications are possible (e.g.,
variations in sizes, dimensions, structures, shapes and proportions
of the various elements, values of parameters, mounting
arrangements, use of materials, colors, orientations, circuit form,
type and interaction, use of sensors, etc.) without materially
departing from the novel teachings and advantages of the subject
matter recited herein. For example, elements shown as integrally
formed may be constructed of multiple parts or elements, the
position of elements may be reversed or otherwise varied, and the
nature or number of discrete elements or positions may be altered
or varied. Other substitutions, modifications, changes and
omissions may be made in the design, operating conditions and
arrangement of the preferred and other exemplary embodiments
without departing from the scope of the present inventions.
[0162] The order or sequence of any process or method steps may be
varied or re-sequenced according to alternative embodiments. In the
claims, any means-plus-function clause is intended to cover the
structures described herein as performing the recited function and
not only structural equivalents but also equivalent structures.
Other substitutions, modifications, changes and omissions may be
made in the design, operating configuration and arrangement of the
preferred and other exemplary embodiments without departing from
the spirit of the present inventions as expressed in the appended
claims.
[0163] Although the best mode contemplated by the inventors of
carrying out the present invention is disclosed above, practice of
the present invention is not limited thereto. It will be manifest
that various additions, modifications, and rearrangements of the
features of the present invention may be made without deviating
from the spirit and scope of the underlying inventive concept. In
addition, the individual components need not be fabricated from the
disclosed materials, but could be fabricated from virtually any
suitable materials. Moreover, the individual components need not be
formed in the disclosed shapes, or assembled in the disclosed
configuration, but could be provided in virtually any shape, and
assembled in virtually any configuration. Further, although various
components as described herein as physically separate modules, it
will be manifest that they may be integrated into the apparatus
with which they are associated. Furthermore, all the disclosed
features of each disclosed embodiment can be combined with, or
substituted for, the disclosed features of every other disclosed
embodiment except where such features are mutually exclusive.
[0164] It is intended that the appended claims cover all such
additions, modifications and rearrangements. Expedient embodiments
of the present invention are differentiated by the appended
claims.
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