U.S. patent number RE42,513 [Application Number 11/334,819] was granted by the patent office on 2011-07-05 for rfid--controlled smart range and method of cooking and heating.
This patent grant is currently assigned to HR Technology, Inc.. Invention is credited to Brian L. Clothier.
United States Patent |
RE42,513 |
Clothier |
July 5, 2011 |
RFID--controlled smart range and method of cooking and heating
Abstract
A system and method for providing multiple cooking modes and an
ability to automatically heat cooking vessels and other objects
using RFID technology, and an ability to read and write heating
instructions and to interactively assist in their execution. An
induction heating range is provided with two antennas per hob, and
includes a user interface display and input mechanism. The vessel
includes an RFID tag and a temperature sensor. In a first cooking
mode, a recipe is read by the range and the range assists a user in
executing the recipe by automatically heating the vessel to
specified temperatures and by prompting the user to add
ingredients. The recipe is written to the RFID tag so that if the
vessel is moved to another hob, into which the recipe has not been
read, the new hob can read the recipe from the RFID tag and
continue in its execution.
Inventors: |
Clothier; Brian L. (Wichita,
KS) |
Assignee: |
HR Technology, Inc. (Wichita,
KS)
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Family
ID: |
32775636 |
Appl.
No.: |
11/334,819 |
Filed: |
January 18, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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60444327 |
Jan 30, 2003 |
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Reissue of: |
10355989 |
Jan 31, 2003 |
6953919 |
Oct 11, 2005 |
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Current U.S.
Class: |
219/620; 219/494;
99/325; 219/667; 219/627; 219/621 |
Current CPC
Class: |
H05B
6/062 (20130101); H05B 2213/06 (20130101) |
Current International
Class: |
H05B
6/12 (20060101); H05B 6/06 (20060101) |
Field of
Search: |
;99/451,325
;340/572.1,825.37 ;219/620-627,663-667,702-720,494,497 |
References Cited
[Referenced By]
U.S. Patent Documents
|
|
|
1975436 |
October 1934 |
Sorrel et al. |
1975437 |
October 1934 |
Sorrel |
1975438 |
October 1934 |
Sorrel |
2988623 |
June 1961 |
Ross et al. |
3153132 |
October 1964 |
Greene |
3612803 |
October 1971 |
Klaas |
3734077 |
May 1973 |
Murdough et al. |
3742174 |
June 1973 |
Harnden, Jr. |
3742178 |
June 1973 |
Harnden, Jr. |
3742179 |
June 1973 |
Harnden, Jr. |
3745290 |
July 1973 |
Harnden, Jr. et al. |
3761668 |
September 1973 |
Harnden, Jr. et al. |
3777094 |
December 1973 |
Peters, Jr. |
3786220 |
January 1974 |
Harnden, Jr. |
3806688 |
April 1974 |
MacKenzie et al. |
3828164 |
August 1974 |
Fischer et al. |
3843857 |
October 1974 |
Cunningham |
3916872 |
November 1975 |
Kreis et al. |
3978307 |
August 1976 |
Amagami et al. |
3979572 |
September 1976 |
Ito et al. |
3989916 |
November 1976 |
Amagami et al. |
4013859 |
March 1977 |
Peters, Jr. |
4016392 |
April 1977 |
Kobayashi et al. |
4020310 |
April 1977 |
Souder, Jr. et al. |
4032740 |
June 1977 |
Mittelmann |
4035606 |
July 1977 |
Browder |
4110587 |
August 1978 |
Souder, Jr. et al. |
4115676 |
September 1978 |
Higuchi et al. |
4235282 |
November 1980 |
de Filippis et al. |
4246884 |
January 1981 |
Vandas |
4256945 |
March 1981 |
Carter et al. |
4266108 |
May 1981 |
Anderson et al. |
4319109 |
March 1982 |
Bowles |
4381438 |
April 1983 |
Goessler et al. |
4454403 |
June 1984 |
Teich et al. |
4456807 |
June 1984 |
Ogino et al. |
4527031 |
July 1985 |
Aparicio |
4533807 |
August 1985 |
Minamida |
4542271 |
September 1985 |
Tanonis et al. |
4544818 |
October 1985 |
Minamida |
4555608 |
November 1985 |
Mizukawa et al. |
4556770 |
December 1985 |
Tazima et al. |
4560849 |
December 1985 |
Migliori et al. |
4567877 |
February 1986 |
Sepahpur |
4568810 |
February 1986 |
Carmean |
4572864 |
February 1986 |
Benson et al. |
4587406 |
May 1986 |
Andre |
4614852 |
September 1986 |
Matsushita et al. |
4617442 |
October 1986 |
Okuda |
4625098 |
November 1986 |
Joe |
4638135 |
January 1987 |
Aoki |
4646935 |
March 1987 |
Ulam |
4764652 |
August 1988 |
Lee |
4774395 |
September 1988 |
Yabuuchi et al. |
4776386 |
October 1988 |
Meier |
4795886 |
January 1989 |
Carter, Jr. |
4810847 |
March 1989 |
Ito |
4816633 |
March 1989 |
Mucha et al. |
4816646 |
March 1989 |
Solomon et al. |
4820891 |
April 1989 |
Tanaka et al. |
4864088 |
September 1989 |
Hiejima et al. |
4914267 |
April 1990 |
Derbyshire |
4916290 |
April 1990 |
Hawkins |
4982722 |
January 1991 |
Wyatt |
4983798 |
January 1991 |
Eckler et al. |
4987828 |
January 1991 |
Nuns et al. |
4996405 |
February 1991 |
Poumey et al. |
RE33644 |
July 1991 |
Hall |
5052369 |
October 1991 |
Johnson |
5078050 |
January 1992 |
Smith |
5079398 |
January 1992 |
Kuziemka |
5125391 |
June 1992 |
Srivastava et al. |
5129314 |
July 1992 |
Hu |
5134265 |
July 1992 |
Dickens et al. |
5177333 |
January 1993 |
Ogasawara |
5180075 |
January 1993 |
Montalbano |
5194708 |
March 1993 |
Carter, Jr. |
5202150 |
April 1993 |
Benson et al. |
5227597 |
July 1993 |
Dickens et al. |
5254380 |
October 1993 |
Salyer |
5379042 |
January 1995 |
Henoch |
5401939 |
March 1995 |
Iguchi et al. |
5408073 |
April 1995 |
Jeong |
5424514 |
June 1995 |
Lee |
5424519 |
June 1995 |
Salee |
5466915 |
November 1995 |
Meier et al. |
5487329 |
January 1996 |
Fissler |
5493103 |
February 1996 |
Kuhn |
5499017 |
March 1996 |
Beigel |
5518560 |
May 1996 |
Li |
5530702 |
June 1996 |
Palmer et al. |
5603858 |
February 1997 |
Wyatt et al. |
5611328 |
March 1997 |
McDermott |
5643485 |
July 1997 |
Potter et al. |
5648008 |
July 1997 |
Barritt et al. |
5682143 |
October 1997 |
Brady |
5705794 |
January 1998 |
Gillespie et al. |
5750962 |
May 1998 |
Hyatt |
5874902 |
February 1999 |
Heinrich et al. |
5880435 |
March 1999 |
Bostic |
5885636 |
March 1999 |
Carville |
5892202 |
April 1999 |
Baldwin et al. |
5928551 |
July 1999 |
Okabayashi |
5932129 |
August 1999 |
Hyatt |
5951900 |
September 1999 |
Smrke |
5954984 |
September 1999 |
Ablah et al. |
5963134 |
October 1999 |
Bowers et al. |
5963144 |
October 1999 |
Kruest |
5968398 |
October 1999 |
Schmitt et al. |
5999700 |
December 1999 |
Geers |
6018143 |
January 2000 |
Check |
6025780 |
February 2000 |
Bowers et al. |
6046442 |
April 2000 |
Kawamura et al. |
6060696 |
May 2000 |
Bostic |
6072383 |
June 2000 |
Gallagher, III et al. |
6097014 |
August 2000 |
Kirsch |
6108489 |
August 2000 |
Frohlich et al. |
6114675 |
September 2000 |
Wada et al. |
6121585 |
September 2000 |
Dam |
6201474 |
March 2001 |
Brady et al. |
6232585 |
May 2001 |
Clothier et al. |
6274856 |
August 2001 |
Clothier et al. |
6316750 |
November 2001 |
Levin |
6316753 |
November 2001 |
Clothier et al. |
6320169 |
November 2001 |
Clothier |
6342830 |
January 2002 |
Want et al. |
6350972 |
February 2002 |
Wright et al. |
6353208 |
March 2002 |
Bostic et al. |
6359268 |
March 2002 |
Walter |
6384387 |
May 2002 |
Owens et al. |
6444961 |
September 2002 |
Clothier et al. |
6504135 |
January 2003 |
Clothier et al. |
6512211 |
January 2003 |
Lockhart et al. |
6664520 |
December 2003 |
Clothier |
2001/0032546 |
October 2001 |
Sharpe |
2002/0008102 |
January 2002 |
Boyd et al. |
2003/0001009 |
January 2003 |
Collins et al. |
|
Foreign Patent Documents
|
|
|
|
|
|
|
294154 |
|
Jan 1954 |
|
CH |
|
2504827 |
|
Aug 1975 |
|
DE |
|
3501304 |
|
Jul 1985 |
|
DE |
|
4024432 |
|
Feb 1992 |
|
DE |
|
4208249 |
|
Sep 1993 |
|
DE |
|
4439095 |
|
Nov 1994 |
|
DE |
|
4428353 |
|
Feb 1995 |
|
DE |
|
4439095 |
|
May 1996 |
|
DE |
|
19729662 |
|
Jul 1997 |
|
DE |
|
19648397 |
|
Nov 1997 |
|
DE |
|
19637561 |
|
Feb 1998 |
|
DE |
|
19714701 |
|
Oct 1998 |
|
DE |
|
19729661 |
|
Jan 1999 |
|
DE |
|
19818831 |
|
Oct 1999 |
|
DE |
|
0098497 |
|
Jun 1983 |
|
EP |
|
0354151 |
|
Feb 1990 |
|
EP |
|
0404209 |
|
Dec 1990 |
|
EP |
|
0412875 |
|
Feb 1991 |
|
EP |
|
0453634 |
|
Oct 1991 |
|
EP |
|
0251333 |
|
Dec 1992 |
|
EP |
|
0427879 |
|
Feb 1993 |
|
EP |
|
0346860 |
|
Jan 1995 |
|
EP |
|
0450744 |
|
Oct 1995 |
|
EP |
|
0453634 |
|
Jan 1996 |
|
EP |
|
0412875 |
|
Apr 1996 |
|
EP |
|
0725556 |
|
Aug 1996 |
|
EP |
|
0757509 |
|
Feb 1997 |
|
EP |
|
0921708 |
|
Jun 1999 |
|
EP |
|
1239703 |
|
Sep 2002 |
|
EP |
|
2199545 |
|
Jul 1988 |
|
GB |
|
2308947 |
|
Jul 1997 |
|
GB |
|
6463989 |
|
Mar 1989 |
|
JP |
|
6489273 |
|
Apr 1989 |
|
JP |
|
0298899 |
|
Aug 1990 |
|
JP |
|
03-192684 |
|
Aug 1991 |
|
JP |
|
6124776 |
|
May 1994 |
|
JP |
|
11067439 |
|
Sep 1999 |
|
JP |
|
2002-367764 |
|
Dec 2002 |
|
JP |
|
9524817 |
|
Sep 1995 |
|
WO |
|
9711578 |
|
Mar 1997 |
|
WO |
|
9805184 |
|
Feb 1998 |
|
WO |
|
9941950 |
|
Aug 1999 |
|
WO |
|
9949766 |
|
Oct 1999 |
|
WO |
|
WO 0119141 |
|
Mar 2001 |
|
WO |
|
Other References
Cooking & Laundry Technology; Automatic Cooktop; Reprinted from
AM--Appliance Manufacturer, Feb. 2002. cited by other .
Flyer for Trade Show: 2002 International Appliance Tech. Conf. Held
Mar. 25-27, 2002. cited by other .
European Supplemental Search Report dated Jun. 9, 2007. cited by
other .
Japanese Patent Abstract; Publication No. 54-25542 B2; Publication
Date: Feb. 26, 1979. cited by other .
Japanese Patent Abstract Publication; Publication No. 10-149875 A;
Publication Date: Jun. 2, 1998. cited by other .
Japanese Publication; Publication No. 2001-122342; Publication
Date: Aug. 5, 2001. cited by other .
U.S. Provisional Patent Application entitled Heat Retentive Food
Servingware With Temperature Self-Regulating Phase Change Core;
U.S. Appl. No. 60/044,074; Inventor: Ablah Amil et al.; filed Jun.
15, 1996. cited by other .
U.S. Provisional Patent Application entitled Temperature
Self-Regulating, Inductively Heatable Vessels for Cooking, Warming,
Serving, and Storing Food and Method; U.S. Appl. No. 60/035,815;
Inventor: Ablah Amil et al; filed Jan. 8, 1997. cited by other
.
U.S. Patent Application entitled Heat Retentive Food Servingware
With Temperature Self-Regulating Phase Change Core; U.S. Appl. No.
08/902,803; Inventor: Ablah Amil et al; filed Jul. 30, 1997. cited
by other .
U.S. Patent Application entitled Temperature Self-Regulating Food
Delivery System; U.S. Appl. No. 09/314,824; Inventor: Ablah Amil et
al; filed May 19, 1999. cited by other .
U.S. Patent Application entitled Heat Retentive Food Servingware
With Temperature Self-Regulating Phase Change Core; U.S. Appl. No.
08/688,987; Inventor: Brian Clothier; filed Jul. 31, 1999. cited by
other .
U.S. Patent Application Publication; Publication No. US
2001/0032546 A1; Publication Date: Oct. 25, 2001. cited by other
.
U.S. Patent Application entitled Temperature Self-Regulating Food
Delivery System; U.S. Appl. No. 10/046,885; Inventor: Ablah Amil et
al; filed Jan. 15, 2002. cited by other .
U.S. Patent Application Publication; Publication No. US
2002/0008102 A1; Publication Date: Jan. 24, 2002. cited by other
.
Author Unknown. Kitchen Kapers Kitchenware Superstore.
www.kitchenkapers.com/vesmirroylav.html. cited by other .
Author Unknown. Scholtes--the Revolution Induction.
www.scholtes.fr/induction/inductions/3.sub.--1.html. cited by other
.
Author Unknown. DIAS GmbH--Uncoiled Infrarred Detectors.
www.dias-infrared.de/eng/products/sensors/sen.sub.--frm.php. cited
by other .
Author Unknown. Smart Pan RF Smart Cooktop System. Digital
Cookware, Inc. www.digitalcookwareinc.com/NU810RF.htm. cited by
other .
Carter Hoffmann Corporation; Patient Meal Make-up and Delivery
System Offers You Better Choices. cited by other .
CookTek, Induction Cooking System; Smarktpak Pizza Thermal Delivery
System PTDS-100, PTDS-200. cited by other .
Metcal, The SmartHeat Company; Metcal SCC Soldering Cartridges.
cited by other .
Metcal, The SmartHeat Company; Metcal Tips and Accessories. cited
by other .
Metcal, The SmartHeat Company; Metcal/STSS Systems. cited by other
.
Seco Products Corporation; Healthcare Mini Catalog. cited by other
.
Seco Products Corproration; System 9-9 Unitized Base. cited by
other .
Seco Products Corporation; System 9-molded Cover for 9'' Unitized
Base System 7-molded Cover for 73/4'' Unitized Base. cited by other
.
Seco Products Corporation; Unitized Base Dispensers. cited by other
.
Seco Products Corporation; System 9-Combination Base/China Dispense
Base/Tray Dispenser. cited by other .
S. Zinn and S.L. Semiatin, Elements of Induction Heating Design,
Control, and Applications, pp. 157-161 (Battelle Press 1988). cited
by other .
Therma-Systems Corporation; Solutions Made Easy. cited by other
.
Tzeng, Jim J-W., George Getz, Brian S. Fedor, and Dan W.
Krassowski. "Anisoptropic Graphite Heat Spreaders for Electronics
Thermal Management". Graftech, Inc. cited by other.
|
Primary Examiner: Van; Quang T
Attorney, Agent or Firm: Hovey Williams LLP
Parent Case Text
RELATED APPLICATIONS
The present application claims priority benefit of and hereby
incorporates by reference a provisional application titled
"RFID-CONTROLLED SMART INDUCTION RANGE", Ser. No. 60/444,327, filed
Jan. 30, 2003. .Iadd.Reference is also made to divisional reissue
application Ser. No. 11/774,696, filed Jul. 9, 2007..Iaddend.
Claims
What is claimed is:
1. A method of heating a vessel using a range having an RFID
.[.reader/writer.]. .Iadd.reader.Iaddend., wherein the vessel
includes an RFID tag and a temperature sensor, the method
comprising the steps of: (a) reading a set of heating instructions
from an external storage medium .Iadd.separate from said vessel and
selected from the group consisting of a recipe card and a food
package.Iaddend., wherein the heating instructions include a
sequence of one or more heating steps, with at least one of the
heating steps including a desired temperature; (b) detecting the
vessel and identifying vessel information; (c) reading the actual
temperature of the vessel from the RFID tag; (d) determining a
temperature differential between the desired temperature of the set
of heating instructions and the actual temperature; and (e)
controlling heating of the vessel based at least in part upon the
temperature differential.
2. The method as set forth in claim 1, further comprising the step
of repeating steps (c)-(e) until the sequence of heating steps is
complete.
.[.3. The method as set forth in claim 1, further comprising the
step of writing the set of heating instructions to the vessel RFID
tag..].
4. The method as set forth in claim .[.3.]. .Iadd.16.Iaddend.,
wherein the action of detecting .[.and identifying.]. the vessel
further includes detecting whether a second set of heating
instructions in the vessel RFID tag is in progress and proceeding
without the action of writing if a second set of heating
instructions is in progress.
5. The method as set forth in claim 1, wherein the set of heating
instructions is a recipe.
6. The method as set forth in claim 1, wherein the external storage
medium of step (a) is contained on a RFID tag associated with a
food package.
7. The method as set forth in claim 1, wherein the external storage
medium of step (a) is contained on a RFID tag associated with a
recipe card.
8. The method as set forth as set forth in claim 1, further
comprising the step of prompting a user to perform an action in
accordance with the set of heating instructions.
9. The method as set forth in claim 8, wherein the step of
prompting a user further comprises delaying the next heating
instruction step until a user provides an input to the range.
10. The method as set forth in claim .[.1.]. .Iadd.16.Iaddend.,
further including the step of writing a heating history to the RFID
tag so that if the vessel is moved to a second RFID reader/writer
the second RFID reader/writer can read the heating history.
11. The method as set forth in claim 10, wherein the heating
history includes a last known actual temperature, a time when the
last known actual temperature occurred, and a last step completed
in the sequence of beating steps prior to the vessel being moved to
the second RFID reader/writer.
12. The method as set forth in claim 10, further including the step
of determining from the heating history an elapsed time as a
difference between a current time and the time when the last known
actual temperature occurred.
13. The method as set forth in claim 12, wherein if the elapsed
time is greater than a first pre-established value then the last
step completed in the sequence of heating steps is repeated.
14. The method as set forth in claim 12, wherein if the elapsed
time is less than .[.the.]. .Iadd.a .Iaddend.first pre-established
value then .[.the.]. a next step in the sequence of heating steps
is begun, wherein the next step in the sequence of heating steps
immediately follows the last step in the sequence of heating
steps.
15. The method as set forth in claim 1, further including the step
of modifying the heating instructions in response to the identified
vessel information.
16. A method of heating a vessel using an induction range having an
RFID reader/writer, wherein the vessel includes an RFID tag and a
temperature sensor, the method comprising the steps of: (a) reading
a set of heating instructions from an external storage medium
.Iadd.separate from said vessel and selected from the group
consisting of a recipe card and a food package.Iaddend., wherein
the heating instructions include a sequence of one or more heating
steps, with at least one of the heating steps including a desired
temperature; (b) detecting the vessel and writing the set of
heating instructions to the vessel RFID tag; (c) reading the actual
temperature of the vessel from the RFID tag; (d) determining a
temperature differential between the desired temperature of the set
of heating instructions and the actual temperature; and (e)
controlling heating of the vessel based at least in part upon the
temperature differential.
.Iadd.17. The method as set forth in claim 16, further including
the step of modifying the heating instructions in response to the
identified vessel information..Iaddend.
.Iadd.18. The method of claim 1, further comprising the step of
repeating steps (b)(i)-(iii)..Iaddend.
.Iadd.19. The method of claim 1, further comprising the step of
writing the set of heating instructions to the vessel RFID tag
(24)..Iaddend.
.Iadd.20. The method of claim 1, further comprising the step of
prompting a user to perform an action in accordance with said
heating instructions..Iaddend.
.Iadd.21. A method of heating a vessel (28) using a range (22)
having an RFID reader (52), wherein the vessel (28) is on said
range (22) and the vessel (28) includes an RFID tag (24) and a
temperature sensor (26) operably coupled with the RFID tag (24) so
that information about the actual temperature of the vessel (28)
sensed by said sensor (26) is received by said RFID tag (24), the
vessel RFID tag (24) storing information confirming the presence of
said RFID tag (24) and said temperature sensor (26), the method
comprising the steps of: (a) loading heating instructions onto said
reader (52) from a recipe card, food package, or other item
separate from the vessel (28), including one or more heating steps
including a desired vessel regulation temperature; (b) heating said
vessel (28) by (i) reading the temperature of the vessel (28) from
the vessel's associated RFID tag (24); (ii) determining a
temperature differential between said desired temperature and the
vessel temperature; and (iii) controlling the heating of said
vessel (28) based upon the temperature differential and said
heating instructions, said heating step being carried out only if
said reader (52) detects the presence of a suitable vessel
(28)..Iaddend.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates broadly to cooking devices and
apparatuses, particularly magnetic induction ranges. More
particularly, the present invention relates to a magnetic induction
range providing multiple cooking modes and an ability to
automatically heat cooking vessels and other objects using RFID
technology and temperature sensing, and an ability to read and
write recipe or heating instructions using the RFID technology and
to interactively assist in their execution.
2. Description of the Prior Art
It is often desirable to automatically monitor and control the
temperature of food in a cooking or heating vessel using
non-contact temperature-sensing means. Early attempts to do so
include, for example, U.S. Pat. No. 5,951,900 to Smrke, U.S. Pat.
No. 4,587,406 to Andre, and U.S. Pat. No. 3,742,178 to Harnden, Jr.
These patents disclose non-contact temperature regulation devices
and methods employing magnetic induction heating, including using
radio frequency transmissions to communicate temperature
information between the object to be heated and the induction
heating appliance, in an attempt to control the induction heating
process. More specifically, in Smrke, Andre, and Harnden a
temperature sensor is attached to the object to be heated to
provide feedback information which is transmitted in a non-contact
manner to the induction appliance. In each case, aside from manual
inputs by a user, changes to the induction appliance's power output
are automatic and based solely upon information gathered and
transmitted by the temperature sensor.
No known employment of the aforementioned prior art technology has
resulted. However, other attempts to monitor and control the
temperature of a vessel during cooking or holding using non-contact
methods employing magnetic induction heaters and other electric
hobs have been employed in the marketplace. Bosch, a major
appliance manufacturer, has, for example, recently introduced
ranges and cooking vessels that, together, provide a system using
temperature feedback, based on temperature information gathered
from the external surface of the vessel, to allow for automatically
varying power output to the vessel and thereby control its
temperature. As described in a paper titled "Infrared Sensor to
Control Temperature of Pots on Consumer Hobs", authored by Uwe Has
of Bosch-Siemens Hausgerate GmbH, Bosch's system employs an
infrared sensor that is an integral part of the cooking hob. The
infrared sensor is mounted on a cylindrical casing that is designed
to direct the infrared sensing beam onto a specific portion of the
cooking vessel at a height of approximately thirty millimeters
above the bottom of the vessel. The temperature information
gathered from the infrared sensor beam is used to alter the power
output of the hob. Unfortunately, Bosch's infrared system suffers
from a number of limitations, including, for example, an
undesirably extreme sensitivity to changes in the emissivity of the
region of the vessel on which the infrared sensor beam is directed.
If the vessel's surface becomes soiled or coated with oil or
grease, the emissivity changes and, as a result, the perceived or
sensed temperature is not the actual temperature.
A cooking system comprising an induction range, marketed by
Scholtes, and an accompanying infrared/radio frequency sensing
device called the "Cookeye", marketed by Tefal, moves beyond the
functionality of the Bosch range system. The Cookeye sensing unit
rests upon the handle of the cooking vessel and directs an infrared
sensor beam downward onto the food within the vessel to sense the
temperature of the food. The Cookeye unit converts the temperature
information into a radio frequency signal that is transmitted to a
radio frequency receiving unit within the induction range. This
radio frequency temperature information is used to alter the power
output of the hob to control the temperature of the vessel.
Furthermore, the system provides six preprogrammed temperatures,
with each temperature corresponding to a class of foods, that the
user can select by pressing a corresponding button on a control
panel. Once one of the preprogrammed temperatures has been
selected, the hob heats the vessel to that temperature and
maintains the vessel at that temperature indefinitely.
Unfortunately, the Scholtes/Tefal system also suffers from a number
of limitations, including, for example, an excessive sensitivity to
the emissivity of the food surfaces within the pan. Furthermore,
though the six preprogrammed temperatures are an improvement over
the Bosch product, they are still too limiting. Many more
selectable temperatures are needed to most effectively or desirably
cook or hold different types food.
It is also often desirable that a cooking apparatus provide
features that allow for or facilitate substantially automatic
preparation of culinary dishes. Attempts to design such a cooking
apparatus include, for example, U.S. Pat. No. 4,649,810 to Wong.
Wong discloses the broad concept of a microcomputer-controlled,
integrated cooking apparatus for automatically preparing culinary
dishes. In use, the constituent ingredients of a particular dish
are first loaded into a compartmentalized carousel which is mounted
on the cooking apparatus. The apparatus includes a memory for
storing one or more recipe programs, each of which may specify a
schedule for dispensing the ingredients from the carousel to a
cooking vessel, for heating the vessel (either covered or
uncovered), and for stirring the contents of the vessel. These
operations are performed substantially automatically under the
control of the microcomputer. Unfortunately, Wong suffers from a
number of limitations, including, for example an undesirable
reliance on a contact temperature sensor that is maintained in
contact with the bottom of the cooking vessel by a thermal contact
spring. Those with ordinary skill in the art will appreciate that
such temperature measurements are notoriously unreliable because
the contact is often not perfect when the vessel is placed upon the
probe.
U.S. Pat. Nos. 6,232,585 and 6,320,169 to Clothier describe an
RFID-equipped induction system that integrates an RFID
reader/writer into the control system of the induction cooktop so
as to utilize stored process information in an RFID tag attached to
a vessel to be heated and to periodically exchange feedback
information between the RFID tag and the RFID reader/writer. This
system allows many different objects to be uniquely and
automatically heated to a pre-selected regulation temperature
because the required data is stored on the RFID tag. Unfortunately,
Clothier suffers from a number off limitations, including, for
example, that it does not employ real-time temperature information
from a sensor attached to the vessel. Furthermore, the system does
not allow the user to manually select a desired regulation
temperature via a control knob on the range's control panel and
have the hob substantially automatically achieve that desired
temperature and maintain it indefinitely regardless of temperature
changes in the food load. Thus, with Clothier, the user could not,
for example, fry frozen food in a fry pan without continually
having to manually adjust the power output of the hob during the
cooking process.
Due to the above-identified and other problems and limitations in
the prior art, an improved mechanism is needed for cooking and
heating.
SUMMARY OF THE INVENTION
The present invention overcomes the above-identified problems and
limitations in the prior art with a system and method providing
multiple cooking modes and an ability to automatically heat cooking
vessels and other objects using RFID technology and temperature
sensing, and an ability to read and write recipe or heating
instructions using the RFID technology and to interactively assist
in their execution. In a preferred embodiment, the system broadly
comprises an induction cooking appliance; an RFID tag; and a
temperature sensor, wherein the RFID tag and the temperature sensor
are associated with the cooking vessel. The induction cooking
appliance, or "range", is adapted to heat the vessel using a
well-known induction mechanism whereby an electric heating current
is induced in the vessel. The range broadly includes a plurality of
bobs, each including a microprocessor, an RFID reader/writer, and
one or more RFID antennas; and a user interface including a display
and an input mechanism. Although the preferred embodiment range
employs magnetic induction, this invention may also utilize ranges
employing electric resistance, electric radiant, halogen, gas, or
other known energy transfer means. Accordingly, throughout this
description a "range" may include cooking systems that employ any
of these varieties of energy transfer means.
The RFID reader/writer facilitates communication and information
exchange between the microprocessor and the RFID tag. More
specifically, the RFID reader/writer is operable to read
information stored in the RFID tag relating to process and feedback
information, such as, for example, the vessel's identity,
capabilities, and heating history.
The one or more RFID antennas facilitate the aforementioned
communications and information exchange. Preferably, two RFID
antennas, a center RFID antenna and a peripheral RFID antenna, are
employed at each hob. The peripheral RFID antenna provides a read
range that covers an entire quadrant of the hob's periphery such
that the handle of the vessel, with the RFID tag located therein,
can be located anywhere within a relatively large radial angle and
still be in communication with the RFID reader/writer. Using two
RFID antennas may require that they be multiplexed to the RFID
reader/writer. Alternatively, it is also possible to power both
RFID antennas at all times without sacrificing significant
read/write range by configuring the RFID antennas in parallel.
The user interface allows for communication and information
exchange between the range and the user. The display may be any
conventional liquid crystal display or other suitable display
device. Similarly, the input mechanism may be an easily cleaned
membranous keypad or other suitable input device, such as, for
example, one or more switches or buttons.
The RFID tag is, as mentioned, associated with the vessel, and is
operable to communicate and exchange data with the hob's
microprocessor via the RFID reader/writer. More specifically, the
RFID tag stores the process and feedback information, including
information concerning the vessel's identity, capabilities, and
heating history, and can both transmit and receive that and other
information to and from the RFID reader/writer. The RFID tag must
also have sufficient memory to store the recipe or heating
information, as discussed below.
The temperature sensor is connected to the RFID tag and is operable
to gather information regarding the temperature of the vessel. The
temperature sensor must touch an outside surface of the vessel.
Furthermore, the point of attachment is preferably located no more
than one inch above the induction-heated surface of the vessel.
Wires connecting the temperature sensor to the RFID tag may be
hidden, such as, for example, in the vessel's handle or in a metal
channel.
In exemplary use and operation, the system functions as follows.
The system provides at least three different modes of operation:
Mode 1; Mode 2; and Mode 3. When the range is first powered-up, the
hobs default to Mode 1. Mode 1 requires temperature feedback, thus
Mode 1 can only be used with vessels having both an RFID tag and a
temperature sensor. The hob's microprocessor awaits information
from the RFID reader/writer indicating that a vessel having these
components and capabilities has been placed on the hob. This
information includes a "class-of-object" code that identifies,
among other things, the vessel's type and the presence of the
temperature sensor. Until this information is received, no current
is allowed to flow in the work coil, and thus no unintended heating
can occur. Once a suitable vessel has been detected, process and
feedback information, described below in greater detail, is
downloaded from the RFID tag and processed by the
microprocessor.
The user may, as desired, download a recipe or other cooking or
heating instructions to the hob. A recipe card, food package, or
other item provided with its own RFID tag on which the recipe is
stored is waved over one of the hob's RFID antennas so that the
RFID reader/writer can read the attached RFID tag and download the
recipe. If a recipe has been downloaded to the hob, and a vessel
appropriate for Mode 1 has been placed on the hob, the RFID
reader/writer will upload or write the recipe information to the
vessel's RFID tag. If the vessel is thereafter moved to a different
hob, the different hob can read the recipe and the process and
feedback information from the vessel's RFID tag and continue with
the recipe from the step last completed or, as appropriate, an
earlier step.
If a recipe has not been scanned into the hob but the hob detects
an appropriate vessel, the hob will check to see if a recipe has
been recently written (by another hob) to the vessel's RFID tag. To
accomplish this, the hob's microprocessor reads the vessel's
process and feedback information to determine an elapsed time since
a recipe was last written to the vessel's RFID tag. If the elapsed
time indicates that a recipe was recently in progress, then the
microprocessor will proceed to complete the recipe after
determining an appropriate point or step within the recipe at which
to start. If, however, the elapsed time indicates that a recipe was
not recently in progress or has been completed, then the
microprocessor may ignore any recipe found in the RFID tag and
prompt the user to for new instructions or to download a new recipe
to the hob.
Following the write operation, the entire recipe is stored in the
vessel's RFID tag. The recipe may include such information as
ingredient details and amounts, a sequence for adding the
ingredients, stirring instructions, desired vessel type, vessel
regulation temperature for each recipe step, maximum power level to
be applied to the vessel during each recipe step, duration of each
recipe step, delay times between each recipe step, holding
temperature following recipe completion and maximum holding time,
and a clock time to begin execution of the recipe so that cooking
can begin automatically at the indicated time.
Once the vessel's RFID tag has been recently programmed with recipe
information, the hob it is on or any other hob it is moved to will
sense this and will immediately read the temperature of the vessel
via its temperature sensor. The hob will then proceed with the
recipe steps to actively assist the user in preparing the food in
accordance with the recipe. Such assistance may include, for
example, prompting the user, via the display of the user interface,
to add specified amounts of ingredients at appropriate times. The
user may be required to indicate, using the input mechanism of the
user interface, that the addition of ingredients or other required
action has been completed. The assistance also preferably includes
automatically heating the vessel to a temperature or series of
temperatures specified by the recipe and maintaining that
temperature for a specified period of time.
During the Mode 1 recipe-following process, a time stamp reflecting
execution of each recipe step as well as the time elapsed since
performing the step is periodically written to the vessel's RFID
tag. If the user removes the vessel from the hob prior to
completion and then replaces the vessel on another hob, the new
hob's microprocessor will continue the recipe process at an
appropriate point within the recipe. This "appropriate point" may
be the next recipe step following the step last completed, or may
be a previous step preceding the last step completed. Furthermore,
if the elapsed timed away from a hob is substantial, adjustments
may need to be made. For example, if the most recently completed
step requires that the vessel be maintained for a certain duration
at a recipe-stipulated temperature, then the duration may need to
be increased if it is determined that the vessel may have cooled
excessively while away from a hob. Preferably, the automatic
assistance provided by the range can be overridden as desired by
the user in order to, for example, increase or decrease the
duration of a step.
Mode 2 is a manual RFID-enhanced mode and also requires temperature
feedback. Thus, Mode 2, like Mode 1, can only be used with vessels
having both an RFID tag and a temperature sensor. The process
information that accompanies the appropriate vessel's
class-of-object code includes a limiting temperature and a
temperature offset value. The limiting temperature is the
temperature above which the hob's microprocessor will not allow the
pan to be heated, thereby avoiding fires or protecting non-stick
surfaces or other materials from exceeding safe temperatures. The
temperature offset value is preferably a percentage of the selected
regulation temperature which becomes a desired temperature during
transient heat-up conditions.
The main function of Mode 2 is to allow the user to place an
appropriate vessel on the hob, to manually select a desired
regulation temperature via the user interface, and to be assured
that the hob will thereafter heat the vessel to achieve and
maintain the selected temperature so long as the selected
temperature does not exceed the limiting temperature. To accomplish
achieving and maintaining the selected temperature without
significant overshoot, Mode 2 periodically calculates a temperature
differential between the actual and selected temperatures and bases
its power output on the temperature differential. For example, if
the temperature differential is relatively large, then the hob may
output full power; but if the temperature differential is
relatively small, then the hob may output less than full power in
order to avoid overshooting the selected temperature.
Mode 3 is a manual power control mode that does not employ any RFID
information, such that any induction-suitable vessel or object can
be heated in Mode 3. Many prior art ranges provide a mode of
operation that is similar to Mode 3. However, a feature of Mode 3
in the present invention which is not disclosed in the prior art is
that if any vessel having an RFID tag and an appropriate
class-of-object code is placed on the hob, the hob will
automatically leave Mode 3 and enter Mode 1 and execute an
appropriate procedure. This feature attempts to prevent the user
from inadvertently employing Mode 3 with a vessel that the user
mistakenly believes will achieve automatic temperature regulation
in that mode.
Thus, it will be appreciated that the cooking and heating system
and method of the present invention provides a number of
substantial advantages over the prior art, including, for example,
providing for precisely and substantially automatically controlling
a temperature of a vessel that has an attached RFID tag.
Furthermore, the present invention advantageously allows a user to
select the desired temperature of the vessel from a wider range of
temperatures than is possible in the prior art. The present
invention also advantageously provides for automatically limiting
heating of the vessel to a pre-established maximum safe
temperature. The present invention also provides for automatically
heating the vessel to a series of pre-selected temperatures for
pre-selected durations. Additionally, the present invention
advantageously ensures that any of several hobs are able to
continue the series of pre-selected temperatures and pre-selected
durations even if the vessel is moved between hobs during execution
of the series. The present invention also advantageously provides
for compensating for any elapsed time in which the vessel was
removed from the range during the series, including, when
necessary, restarting the process or reverting to an appropriate
point in the recipe. Additionally, the present invention
advantageously provides for exceptionally fast thermal recovery of
the vessel to the selected temperature regardless of any change in
cooling load, such as the addition of frozen food to hot oil within
the vessel.
Additionally, the present invention advantageously provides for
reading and storing recipe or other cooking or heating instruction
from food packages, recipe cards, or other items. The recipe may be
stored in an RFID tag on the item and may define the aforementioned
series of pre-selected temperatures for pre-selected durations. The
present invention also advantageously provides for writing the
recipe or other instructions to the RFID tag of the vessel, thereby
allowing execution of the recipe to continue even after the vessel
has been moved to another hob into which the recipe has not been
previously or directly entered. The present invention also
advantageously provides for interactive assistance, including
prompting, in executing the recipe or other instructions.
These and other important aspects of the present invention are more
fully described in the section entitled DETAILED DESCRIPTION OF A
PREFERRED EMBODIMENT, below.
DESCRIPTION OF THE DRAWINGS FIGURES
A preferred embodiment of the present invention is described in
detail below with reference to the attached drawing figures,
wherein:
FIG. 1 is a schematic showing major components of a preferred
embodiment of the cooking and heating system of the present
invention;
FIG. 2 is a schematic showing components of the RFID tag and
temperature sensor used in the system shown in FIG. 1;
FIG. 3 is a first flowchart of method steps involved in a first
mode of operation of the system shown in FIG. 1;
FIG. 4 is a second flowchart of method steps involved in a second
mode of operation of the system shown in FIG. 1;
FIG. 5 is a third flowchart of method steps involved in a third
mode of operation of the system shown in FIG. 1; and
FIG. 6 is a schematic of an RFID tag memory layout used in the
system shown in FIG. 1.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
Referring to the figures, a system 20 and method for cooking and
heating is disclosed in accordance with a preferred embodiment of
the present invention. Broadly, the system 20 and method provides
multiple cooking modes and an ability to automatically heat cooking
vessels and other objects using RFID technology and temperature
sensing, and an ability to read and write recipe or heating
instructions using the RFID technology and to interactively assist
in their execution.
Those with ordinary skill in the arts pertaining to RFID technology
will appreciate that it is an automatic identification technology
similar in application to well-known bar code technology but using
radio-frequency signals rather than optical signals. RFID systems
can be either read-only or read/write. A read-only RFID system
comprises both an RFID reader, such as, for example, the model
OMR-705+ RFID reader by Motorola, and an RFID tag, such as, for
example, the model IT-254E RFID tag by Motorola. The RFID reader
performs several functions, one of which is to produce a low-level
radio-frequency magnetic field, typically either at 125 kHz or at
13.56 MHz. This RF magnetic field emanates from the RFID reader via
a transmitting antenna, typically in the form of a coil. The RFID
reader may be sold as an RFID coupler, which includes a radio
processing unit and a digital processing unit, and a separate,
detachable antenna. The RFID tag also includes an antenna, also
typically in the form of a coil, and an integrated circuit (IC).
When the RFID tag encounters the magnetic field energy of the RFID
reader, it transmits programmed memory information stored in the IC
to the RFID reader. The RFID reader then validates the signal,
decodes the information, and transmits the information to a desired
output device, such as, for example, a microprocessor, in a desired
format. The programmed memory information typically includes a
digital code that uniquely identifies an object to which the RFID
tag is attached, incorporated into, or otherwise associated. The
RFID tag may be several inches away from the RFID reader's antenna
and still communicate with the RFID reader.
A read/write RFID system comprises both an RFID reader/writer, such
as, for example, the model GemWave Medio.TM. SO13 coupler by
Gemplus or the model A-SA detachable antenna by Medio, and the RFID
tag, such as, for example, the model 40-SL read/write tag by Ario,
and is able both to read and write information from and to the RFID
tag. The RFID tag may, after receiving information from the RFID
reader/writer, store and later re-emit information back to that or
another RFID reader/writer. This re-writing and re-transmitting can
be performed either continuously or periodically. Actual
transmission times are short, typically measured in milliseconds,
and transmission rates can be as high as 105 kb/s. Memory in the
RFID tags is typically erasable-programmable read-only memory
(EEPROM), and significant memory storage capacity, typically 2 kb
or more, is often available. Additionally, the RFID reader/writer
may be programmed to communicate with other devices, such as other
microprocessor-based devices, so as to perform complex tasks. RFID
technology is described in substantial detail in U.S. Pat. No.
6,320,169, which is hereby incorporated by reference into the
present application.
Referring to FIG. 1, the preferred embodiment of the system 20 of
the present invention broadly comprises an induction cooking
appliance 22, an RFID tag 24, and a temperature sensor 26, wherein
the RFID tag 24 and the temperature sensor 26 are attached to,
incorporated into, or otherwise associated with a cooking or
heating vessel 28 or other similar object, such as, for example,
servingware. The induction cooking appliance 22, also called a
"cooktop" and hereinafter referred to as a "range", is adapted to
heat the vessel 28 using a well-known induction mechanism whereby
an electric heating current is induced in the vessel 28. The range
22 broadly includes a rectifier 40; a solid state inverter 42; a
plurality of hobs 44, with each hob 44 including an induction work
coil 46, a microprocessor 48, a vessel support mechanism 50, an
RFID reader/writer 52, one or more RFID antennas 54A,54B, a
real-time clock 56, and additional memory 58; a
microprocessor-based control circuit (not shown); and a user
interface 60, including a display 62 and an input mechanism 64.
The range 22 accomplishes induction heating in a substantially
conventional manner. Briefly, the rectifier 40 first converts
alternating current into direct current. The solid state inverter
42 then coverts the direct current into ultrasonic current, having
a frequency of preferably approximately between 20 kHz and 100 kHz.
This ultrasonic frequency current is passed through the work coil
46 to produce a changing magnetic field. The control circuit
controls the inverter 42 and may also control various other
internal and user-interface functions of the range 22, and includes
appropriate sensors for providing relevant input. The vessel
support mechanism 50 is positioned adjacent the work coil 46 so
that the vessel 28, resting on the vessel support mechanism 50, is
exposed to the changing magnetic field.
The RFID reader/writer 52 facilitates communication and information
exchange between the microprocessor 48 and the RFID tag 24. More
specifically, in the present invention the RFID reader/writer 52 is
operable to read information stored in the RFID tag 24 relating to,
for example, the vessel's identity, capabilities, and heating
history. The RFID reader/writer 52 is connected to the
microprocessor 48 using an RS-232 connection. The preferred RFID
reader/writer 52 allows for RS-232, RS485, and TTL communication
protocols and can transmit data at up to 26 kb/s. A suitable RFID
reader/writer for use in the present invention is available, for
example, from Gemplus as the model GemWave.TM. Medio SO13. It
should be noted that, because the RFID reader/writer 52 is
microprocessor-based, it is within the contemplated scope of the
present invention that a single microprocessor could be programmed
to serve both the RFID reader/writer 52 and the range's control
circuit.
The one or more RFID antennas 54A,54B connect to the RFID
reader/writer 52 via a coaxial cable and function to further
facilitate the aforementioned communication and information
exchange. Preferably the RFID antennas 54A,54B are small in size,
lack a ground plane, and have a read/write range of approximately
two inches. Preferably, two RFID antennas, a center RFID antenna
54A and a peripheral RFID antenna 54B, are employed at each hob 44.
The peripheral RFID antenna 54B preferably has a read range that
covers an entire quadrant of the periphery of the work coil 46 such
that a handle 70 of the vessel 28, within which the RFID tag 24 is
located, can be located anywhere within a relatively large radial
angle and still be in communication with the RFID reader/writer 52.
In an equally preferred embodiment, this particular advantage
arising from using two RFID antennas 54A,54B is achieved by using a
single large antenna that can read any RFID tag 24 in the field
above the work coil 46. In both embodiments, the read/write range
of the RFID reader/writer 52 is advantageously larger than the
single center RFID antenna used in the prior art. As desired, it is
also possible to eliminate the center RFID antenna 54A and use only
the peripheral RFID antenna 54B if fewer features are needed.
Using two RFID antennas 54A,54B may require that they be
multiplexed to the RFID reader/writer 52. Multiplexing can be
accomplished using any of several methods. In a first method, a
switching relay is provided that switches the connection between
the RFID reader/writer 52 and the RFID antennas 54A,54B such that
only one RFID antenna is used for transmission at any given time.
It is also possible to power both RFID antennas 54A,54B at all
times without sacrificing significant read/write range by
configuring the RFID antennas 54A,54B in parallel. The location of
the peripheral RFID antenna 54B is chosen so that the RFID tag 24
of the vessel 28 is positioned over the reception area of the
peripheral RFID antenna 54B when the vessel 28 is placed on the hob
44. A suitable RFID antenna for use in the present invention is
available, for example, from Gemplus as the Model 1'' antenna or
the model Medio A-SA antenna.
The real-time clock 56 maintains accurate time over long periods.
Preferably, the clock 56 is microprocessor compatible and contains
a back-up power supply that can operate for prolonged periods even
when the range 22 is unplugged. Typically, the clock 56 has a
crystal-controlled oscillator time base. Suitable clocks for use in
the present invention are well-known in the prior art and are
available, for example, from National Semiconductor as the model
MM58274C or from Dallas Semiconductor as the model DS-1286. It will
be appreciated by those with ordinary skill in the art that the
microprocessor 48 typically includes a real-time clock feature that
can serve as the real-time clock 56.
The additional memory 58 is accessible by the microprocessor 48 and
is capable of being both easily written to and easily replaced so
as to allow the user to add software algorithms whenever a new type
of vessel 28, not previously programmed for, is desired to be used
on the range 22. A suitable memory for use in the present invention
is a flash memory card available, for example, from Micron
Technology, Inc., as the model CompactFlash.TM. card. Another
suitable memory is an EEPROM device or a flash memory device that
includes a modem connection so as to allow for re-programming from
a remote site over a telephone line.
The user interface 60 allows for communication and information
exchange between the range 22 and the user. The display 62 may be
any conventional liquid crystal display or other suitable display
device. Similarly, the input mechanism 64 may be an easily cleaned
membranous keypad or other suitable input device, such as, for
example, one or more switches or buttons.
As mentioned, the RFID tag 24 is affixed to, incorporated into, or
otherwise associated with the cooking or heating vessel 28, and is
operable to communicate and exchange data with the microprocessor
48 via the RFID reader/writer 52. More specifically, the RFID tag
24 stores information concerning the vessel's identity,
capabilities, and heating history, and can both transmit and
receive that information to and from the RFID reader/writer 52. The
RFID tag 24 must also have sufficient memory to store recipe
information, as discussed below. Preferably, the RFID tag 24 is
able to withstand extreme temperatures, humidity, and pressure. A
suitable RFID tag for use in the present invention is available
from Gemplus as the model GemWave.TM. Ario 40-SL Stamp. This
particular RFID tag has dimensions of 17 mm.times.17 mm.times.1.6
mm, and has a factory-embedded 8 byte code in block 0, page 0 of
its memory. It also has 2 Kbits of EEPROM memory arranged in 4
blocks, with each block containing 4 pages of data, wherein each
page of 8 bytes can be written to separately by the RFID
reader/writer 52. Other suitable RFID tags, also from Gemplus,
include the Ario 40-SL Module and the ultra-small Ario 40-SDM.
The temperature sensor 26 is connected to the RFID tag 24 and is
operable to gather information regarding the temperature of the
vessel 28. Any temperature sensor or transducer, such as, for
example, a thermistor or resistance temperature device (RTD), with
a near linear voltage output relative to temperature can be used in
the present invention to provide an analog signal which, when
converted to a digital signal by the RFID tag 12, can be
transmitted to the RFID reader/writer 52 within normal
communication protocols. A suitable, though not necessarily
preferred, RFID reader/writer and passive RFID temperature-sensing
tag was devised for the present invention based upon technology
developed by Phase IV Engineering of Boulder Colo., and Goodyear
Tire and Rubber Company of Akron, Ohio, disclosed in U.S. Pat. No.
6,412,977, issued to Black, et al. on Jul. 2, 2002, titled "Method
for Measuring Temperature with an Integrated Circuit Device", and
U.S. Pat. No. 6,369,712 issued to Letkomiller, et al. on Apr. 9,
2002, titled "Response Adjustable Temperature Sensor for
Transponder", both of which are hereby incorporated by reference
into the present application. Unfortunately, the particular RFID
tag used by Phase IV Engineering provides neither write capability
nor sufficient memory, and thus another RFID tag with these
necessary features must be used in conjunction with the less
capable RFID tag. In order to minimize complexity and cost,
however, the preferred system 20 utilizes only one RFID tag 24 to
perform temperature sensing and other feedback communications and
to process information storage.
The temperature sensor 26 must touch an outside surface of the
vessel 28. If an RTD is used, for example, it may be permanently
attached to the most conductive layer of the vessel 28. For
multi-ply vessels, such as those most commonly used for induction
cooking, the preferred attachment layer is an aluminum layer.
Furthermore, it is preferred to locate the point of attachment no
more than one inch above the induction-heated surface of the vessel
28. The temperature sensor 26 is preferably attached using ceramic
adhesive to an outside surface of the vessel 28 at a location where
the vessel's handle 70 attaches to the vessel's body.
Alternatively, the temperature sensor 26 may be attached using any
other suitable and appropriate mechanism, such as, for example,
mechanical fasteners, brackets, or other adhesives, as long as the
attachment mechanism ensures that the temperature sensor 26 will
maintain sufficient thermal contact with the vessel 28 throughout
its life.
Any wires connecting the temperature sensor 26 to the RFID tag 24
are preferably hidden, such as, for example, in the vessel's handle
70. If the vessel 28 is such that its handle 70 is more than one
inch above the induction-heated surface, the temperature sensor 26
and wires may be hidden within a metal channel so that the RFID tag
24 can remain in the handle 70. Though not essential, the RFID tag
24 is preferably sealed within the handle 70 so that water does not
enter the handle 70 during washing. Referring to FIG. 2, a
schematic is shown of how the temperature sensor 24 may be attached
to the RFID tag 24. The two wire leads of the RFID tag 24 are
welded to the RFID tag 24 such that the welding pads 90A,90B
connect the temperature sensor 26 to the RFID tag's integrated
circuit (IC).
In exemplary use and operation, referring to FIGS. 3-5, the system
20 functions as follows. The system 20 provides at least three
different modes of operation: Mode 1, an enhanced RFID mode, is for
vessels 28 that have both an RFID tag 24 and a temperature sensor
26; Mode 2, a manual RFID mode, is also for vessels 28 that have
both an RFID tag 24 and a temperature sensor 26; and Mode 3, a
manual power control mode, is for vessels that have no RFID tag and
no temperature sensor.
When the range 22 is first powered-up, the hob 44 defaults to Mode
1. The hob's microprocessor 48 awaits information from the RFID
reader/writer 52 indicating that a vessel 28 having a suitably
programmed RFID tag 24 has been placed on the vessel support
structure 50, as depicted in box 200. This information includes a
"class-of-object" code that identifies the vessel's type (e.g.,
frying pan, sizzle pan, pot) and capabilities. Until this
information is received, no current is allowed to flow in the work
coil 46, and thus no unintended heating can occur. If the hob 44 is
provided with two RFID antennas 54A,54B, as is preferred, then the
RFID tag 24 may be read by either the center RFID antenna 54A or
the peripheral RFID antenna 54B. Once the vessel 28 has been
detected, process and feedback information, described below in
greater detail, is downloaded from the RFID tag 24 and processed by
the microprocessor 48, as depicted in box 202. The aforementioned
class-of-object code will inform the microprocessor 48 of or allow
the microprocessor 48 to select an appropriate heating algorithm.
Several different heating algorithms, including those described in
aforementioned U.S. Pat. No. 6,320,169, each employing different
feedback information and process information (stored on the RFID
tag 24), are stored in the additional memory 58 and available to
the microprocessor 48.
At this point, the user may, as desired, download a recipe or other
cooking or heating instructions to the hob 44 as depicted in box
204. A recipe card, food package, or other item provided with its
own RFID tag on which is stored the recipe is simply waved over one
of the hob's two antennas 54A,54B so that the RFID reader/writer 52
can read the attached RFID tag 24 and download the recipe. The
aforementioned process and feedback information may include recipe
steps already completed, including when those steps were
completed.
If the vessel 28 includes both an RFID tag 24 and a temperature
sensor 26, then the class-of-object code will reflect that
capability. If a recipe has been downloaded to the hob 44, and a
vessel 28 having a class-of-object code indicating both an RFID tag
24 and a temperature sensor 26 is placed on the hob 44, the RFID
reader/writer 52 will upload or write the recipe information to the
vessel's RFID tag 24, as depicted in box 206. If the vessel 28 is
thereafter moved to a different hob, the different hob can read the
recipe and the process and feedback information from the vessel's
RFID tag 24 and continue with the recipe from the step last
completed or other appropriate step. In order for the recipe be
written to a vessel's RFID tag 24, the vessel 28 must be placed on
the hob 44 within a fixed time interval, such as, for example,
approximately between 10 seconds and 2 minutes, after the recipe
has been downloaded into the microprocessor 48. Thus, once the
recipe has been downloaded, the hob 44 immediately begins searching
for an RFID tag 24 with the appropriate class-of-object code. If
the hob 44 cannot detect such a vessel 28 during the fixed time
interval, it will cease its attempts and, if the user still wishes
to proceed, the recipe must be downloaded again to initiate a new
fixed time interval.
If a recipe has not been scanned into the hob 44 but the hob 44
detects a vessel 28 having the appropriate class-of-object code,
the hob 44 will check to see if a recipe has been recently written
(by another hob) to the vessel's RFID tag 24, as depicted in box
208. To accomplish this, the hob's microprocessor 48 reads the
vessel's process and feedback information to determine an elapsed
time since a recipe was last written to the vessel's RFID tag 24.
If the elapsed time indicates that a recipe was recently in
progress, then the microprocessor 48 will proceed to complete the
recipe after determining an appropriate point or step within the
recipe at which to start, as depicted in box 210. For example, the
elapsed time and sensed temperature may indicate that the vessel 28
has cooled substantially since completion of a previous heating
step, such that the heating step should be repeated. If, however,
the elapsed time indicates that a recipe was not recently in
progress or has been completed, then the microprocessor 48 may
ignore any recipe found in the RFID tag 24 and prompt the user to
for new instructions or to download a new recipe to the hob 44.
Following the write operation, the entire recipe is stored in the
vessel's RFID tag 24. The recipe may be very long and detailed and
may include ingredients and amounts, a sequence for adding the
ingredients, stirring instructions, desired vessel type, vessel
regulation temperature for each recipe step, maximum power level to
be applied to the vessel 28 during each recipe step (some processes
may require very gentle heating while others can tolerate high
power applications), duration of each recipe step, delay times
between each recipe step, holding temperature (after recipe
completion) and maximum holding time, and a clock time to begin
execution of the recipe so that cooking can begin automatically at
the indicated time. Additional information may be included,
depending on memory space.
Referring to FIG. 6, a schematic 92 is shown of the RFID tag's
layout showing memory locations and memory allocation. This same
layout can be used both in the vessel's RFID tag 24 and in the RFID
tag on which the recipe is initially provided. The following memory
locations, most or all of which store process or feedback
information and are written to by the RFID reader/writer 52
periodically, are shown in FIG. 6:
LKPS (1/2 byte)
The last recipe step executed.
Time(LKPS) (Hr); Time(LKPS) (Min); Time(LKPS) (Sec)
The time from the real-time clock 56 used to provide a time stamp
for calculating elapsed time.
Time in Power Step
An integer corresponding to the amount of time, in ten second
intervals, that the vessel 28 has operated in the current recipe
step. If the vessel 28 is removed from the hob 44 during a recipe
step, then this value will be read when the vessel 28 is replaced
on any hob. The hob's microprocessor 48 will subtract this value
from the step's specified duration and will continue the recipe
step for the remainder of that time. Date (LKPS) (Moo); Date (LKPS)
(Day) The date from the real-time clock 56 used to provide a time
stamp for calculating elapsed time. Internal Check Sum A Cyclic
Redundancy Code (CRC) that is generated by the RFID reader/writer
52 each time a write operation is completed and written to the RFID
tag 24 each time a write operation occurs. Two CRC internal check
sum values are shown, one is in Block 1, Page 0 of memory (B1P0)
and the other is in Block 3, Page 2 of memory (B3P2). Delta t Each
integer of this value represents a 10 ms time interval that occurs
between read operations of the RFID tag 24 by the RFID
reader/writer 52. IPL1-IPL11 These values (0-15) divided by 15 give
the maximum percentage of maximum power allowed during
corresponding recipe power steps. For example, IPL1=15 means that
100% of maximum power may be applied during recipe step #1; IPL2=10
means that 66% of maximum power may be applied during step #2. Max
Step The maximum number of recipe steps plus one. The additional
"plus one" step is a holding step that follows the completion of
all other steps. Max Watts The maximum power, in 20 watt
increments, that the cooking procedure is allowed to apply during
any recipe step (see the description of IPL1-IPLK15, above).
Improper coupling of the vessel 28 with the hob 44 may limit the
true output power of the hob to less than Max Watts. Sleep Time The
number of minutes after which, if no load is detected, the hob 44
will enter a sleep mode wherein which no further searching for RFID
tags nor any output of power is performed. In this sleep state, the
user must provide a mode select input using the range's input
mechanism 64 to re-activate the hob 44. Write Interval A multiple
of Delta t that defines the time interval between writing to the
RFID tag 24 what LKPS and t(LKPS) have just occurred. When the
vessel 28 is removed from the hob 44 and placed on a different hob,
this writing function allows the different hob 44 to determine the
amount of time remaining in the current recipe step. For example,
if Delta t has a value of 200 (making Delta t equal to 2 seconds),
and "Write Interval" has a value of 5, then the RFID tag 24 should
be written to every 10 seconds. T1-T11 The temperature that the hob
44 attempts to maintain during the corresponding recipe step. There
are only ten possible Mode 1 recipe step cooking temperatures, and
one additional "T" value reserved for the holding temperature. The
hob 44 will attempt to maintain the specified temperature using
feedback from the temperature sensor and a learning algorithm that
samples the feedback to calculate temperature differentials from
the desired temperatures and rates of temperature change. Limiting
Temp The maximum temperature that the vessel 28 can safely reach.
If the vessel's temperature reaches this value, the user interface
display 62 flashes the temperature and an appropriate warning. If
the vessel's temperature remains at the Limiting Temperature for a
predetermined length time, such as, for example, approximately 60
seconds, or exceeds the Limiting Temperature, then the hob 44
ceases to heat the vessel 28 and enters the sleep mode and must be
reset before further use. COB The class-of-object code that tells
the hob's microprocessor 48 what type of vessel 28 is present, what
feedback information will be provided, and what heating algorithm
to employ. For example, if the COB has the value of 4, then the hob
44 determines that the vessel has temperature-sensing capability.
If the hob 44 is in Mode 1 when COB=4 is determined, a recent
recipe scan must have been accomplished before the vessel 28 will
be heated, as described above. If the hob 44 is in Mode 2 when
COB=4 is determined, a user-selected regulation temperature will be
maintained, as described below. Temperature Offset This value
accommodates a variety of different vessels and vessel
manufacturers by compensating for the temperature sensors being in
different places on the vessels, some being further away from the
vessels' bottoms than others. This value is needed only during
transient heating conditions, not in maintenance conditions when
the sensed temperature is within a "maintenance band" of
temperatures about the desired regulation temperature. This value
provides flexibility to compensate for different transient lags on
the RFID tag 24. This value equals the percentage of the selected
regulation temperature, and at a sensed temperature equal to the
user-selected temperature minus the Temperature Offset the hob 44
will consider that the desired regulation temperature has been
achieved and will enter a maintenance condition. Time 1-Time 10 The
duration or elapsed time that the vessel 28 must remain at its
respective temperature (see the description of T1-T11, above) or
within 10% of that value before the recipe step is complete and the
hob 44 proceeds to perform the next recipe step. For example, when
recipe step #1 commences, a timer is started; when the timer has
reached a value equal to Time 1, the hob 44 moves to recipe step
#2. If the vessel 28 is removed during a power step, the timer is
reset; when the vessel 28 is replaced, LKPS and Time(LKPS) are used
to determine the elapsed time remaining within that step.
Temperature Coding A toggle switch consisting of two bits in B1-P0.
Either "F" for Fahrenheit or "C" for Celsius is selected. This is
mainly used during initial programming of a recipe (COB=5) so that
the temperature values, T1-T11, of the recipe will be properly
interpreted. Max Hold Time The maximum hold time, in 10 minute
intervals, that a vessel 28 can stay in the maintenance mode before
the hob 44 goes to sleep. Same Object Time This value defines an
interval wherein a vessel 28 can be removed from and replaced on a
hob 44 and the timer will resume without resetting. If the elapsed
time of removal is greater than Same Object Time, then the timer is
reset and the step must be repeated. Pulse Delay (1 byte) This
value defines, in maintenance mode only, the number of write
intervals that pass between each Writing To Tag of B1P0
information. For example, if Pulse Delay equals 0, then the RFID
tag 24 is updated with B1P0 information each write interval.
However, if Pulse Delay equals 3, then 3 write intervals pass
between each write operation to B1PO. Thus, if Write Interval is 2,
Delta t is 100, and Pulse Delay is 3, then once maintenance mode is
entered, 8 seconds would pass between each write operation (2
seconds for temperature check but empty write, 2 seconds to the
next temperature check but empty write, 2 seconds to the next
temperature check but empty write, and then 2 seconds to the next
temperature check, the results of which are written to B1P0.
Internal Check Sum # A CRC (Cyclic Redundancy Code) that is
generated by the RFID reader/writer 52 each time a write operation
is Completed. The CRC check sum value is written to the RFID tag 24
each time a write operation occurs. Two CRC internal check sum
values are shown in memory, one is in Block 1, Page 0 of memory
(B1P0) and one is in Block 3, Page 2 of memory (B3P2).
Once the vessel's RFID tag 24 has been recently programmed with
recipe information, the hob 44 it is on or any other hob it is
moved to will sense this and will immediately read the temperature
of the vessel 28 via its temperature sensor 26, as depicted in box
212. The hob 44 will then proceed with the recipe steps to actively
assist the user in preparing the food in accordance with the
recipe, as depicted in box 214. Such assistance preferably
includes, for example, prompting the user, via the display 62 of
the user interface 60, to add specified amounts of ingredients at
appropriate times. The user may be required to indicate, using the
input mechanism 64 of the user interface 60, that the step of
adding ingredients has been completed. The assistance also
preferably includes automatically heating the vessel 28 to a
temperature specified by the recipe and maintaining that
temperature for a specified period of time. Such assistance may
continue until the recipe is completed.
During the Mode 1 recipe-following process, a time stamp reflecting
execution of each recipe step as well as the time elapsed in
performing the step is periodically written to the vessel's RFID
tag 24, as depicted in box 216. As mentioned, if the user removes
the vessel 28 from a hob 44 prior to completion and then replaces
the vessel 28 on another hob, the new hob's microprocessor will
continue the recipe process at an appropriate point as indicated by
the vessel's RFID tag 24. Adjustments may need to be made to the
recipe times; for example, a total elapsed time at a
recipe-stipulated temperature for the most recent recipe step may
need to be increased because the vessel 28 may have cooled
excessively while away from a hob. Preferably, the automatic
assistance provided by the range 22 can be overridden as desired by
the user in order to, for example, increase or decrease the
duration of a step.
By way of example, the following is a likely sequence of events for
Mode 1 operation of the range 22 with a fry pan vessel 28 having an
RFID tag 24 and temperature sensor 26 in its handle 70. First, the
user scans a food package over the peripheral RFID antenna 54B of
the hob 44 in order to transfer the recipe information stored in
the package's RFID tag 24 to the hob's microprocessor 48. The
range's display 62 then begins to communicate instructions to the
user. Once the fry pan's handle 70 is placed over the peripheral
RFID antenna 54B, the recipe information is uploaded into the pan's
RFID tag 24 and the sequence of cooking operations begins
automatically. Preferably, the user must provide an input via the
input mechanism 64 before the hob 44 begins each cooking operation
in the automatic sequence. This requirement prevents the range
from, for example, heating the pan 28 before a necessary ingredient
is added.
If the cooking vessel does not include a temperature sensor, then,
still operating in Mode 1, the hob will download information from
the RFID tag and begin heating the vessel according to its process
data, feedback data, and appropriate heating algorithm. This
procedure is thoroughly described in U.S. Pat. No. 6,320,169.
If the cooking vessel has no RFID tag or no RFID tag with a
suitable class-of-object code, no heating will occur. The hob 44
will simply continue to search for a suitable RFID tag or wait for
the user to select another operating mode.
Mode 2 is a manual RFID-enhanced mode. Mode 2 is entered via the
input mechanism 64 of the range's user-interface 60. Once in Mode
2, the hob's microprocessor 48 awaits process information from a
suitable RFID tag 24 prior to allowing any current to flow within
the work coil 46 to heat the vessel 28. Mode 2 can be used only for
vessels having both RFID tags and temperature sensors; no other
class-of-object code will allow the user to operate in Mode 2.
Preferably, the process information that accompanies the
appropriate class-of-object code includes a limiting temperature
and a temperature offset value. The limiting temperature, described
above, is the temperature above which the hob's microprocessor 48
will not allow the pan to be heated, thereby avoiding fires or to
protecting non-stick surfaces or other materials from exceeding
designed temperatures. The limiting temperature is programmed into
the vessel's RFID tag 24 by the vessel's manufacturer prior to
sale. The temperature offset value, described above, is preferably
a percentage of the selected regulation temperature which becomes a
desired temperature during transient heat-up conditions. For
example, if the value of the temperature offset is 10, then only
during transient heating or heat-up operations will the hob's
microprocessor 48 attempt to achieve a regulation temperature equal
to the user-selected temperature minus 10%. The use of the
temperature offset value is only necessary during heat-up because
the temperature of the side walls of some vessels (where the
temperature is actually measured) lags behind the average
temperature of the vessels' bottom surfaces. Once the vessel 28 is
in a steady state condition or is in a cool-down mode, the
temperature lag is insignificant and does not warrant the
temperature offset value and associated procedure. Therefore, once
the vessel 28 reaches the desired temperature during a heat-up
condition, the hob's microprocessor 48 reverts to holding the
actual user-selected temperature during the subsequent maintenance
or cool-down sequence.
The main function of Mode 2 is to allow the user to place an
appropriate vessel 28 on the hob 44; to manually select a desired
regulation temperature via the user interface 60; and to be assured
that the hob 44 will thereafter automatically heat the vessel 28 to
achieve and maintain the selected temperature (as long as the
selected temperature does not exceed the limiting temperature)
regardless of the load (food) added or subtracted from the vessel
28. Preferably, the range 22 allows the user to select vessel
regulation temperatures from at least between 68.degree. F. and
500.degree. F.
In operation, Mode 2 proceeds as follows. Once a proper RFID
tag-equipped vessel 28 is placed upon a hob 44 operating in Mode 2,
one of the two RFID antennas 54A,54B will read the class-of-object
code and the aforementioned process data from the RFID tag 24, as
depicted in box 220. Furthermore, the temperature of the vessel 28
is read by the RFID reader/writer 52 and transmitted to the hob
microprocessor 48 (see U.S. Pat. No. 6,320,169 for details
concerning communications between the RFID reader/writer 52 and the
microprocessor 48), as depicted in box 222. Assuming that the
selected or desired temperature is above the sensed temperature and
below the limiting temperature, the hob's work coil 46 will output
an appropriate level of power to heat the vessel 28 from its
present to its desired temperature. By "appropriate" level of
power, it is meant that the microprocessor 48 will calculate a
temperature differential (desired temperature minus sensed
temperature) to determine what power level to apply, as depicted in
box 224. If the temperature differential is large (more than, for
example, 20.degree. F.), the hob will output full power to the
vessel 28, as depicted in box 226. Once the differential is
calculated to be positive but not large (less than 20.degree. F.),
the output power can be reduced to a lower level, such as, for
example, 20% of maximum, as depicted in box 228. This type of
appropriate power selection can reduce temperature overshoot during
heating operations. Also, if a non-zero value of temperature offset
is stored in the RFID tag's memory, the hob 44 will reduce the
power to prevent overshoots based upon an attempt to reach the
selected regulation temperature minus the product of the selected
regulation temperature and the temperature offset value.
Furthermore, once the hob 44 detects that the vessel 28 has
reached, or exceeded, its desired temperature, it can select an
appropriate level of power output to maintain the desired
temperature, as depicted in box 230. By taking periodic temperature
measurements and calculating temperature differentials from the
desired temperature, the microprocessor 48 can select ever-changing
power outputs that will successfully maintain the vessel 28
temperature within a narrow band about the selected regulation
temperature regardless of the cooling food load experienced by the
vessel 28. Of course, this adaptive feature of determining
appropriate power output levels can also be employed in Mode 1 to
maintain a desired temperature.
It will be appreciated that Mode 2 can also include the feature of
Mode 1 involving writing information to the RFID tag 24 so that a
process in progress can be completed by another hob. In Mode 2,
this feature would involve writing the desired temperature to the
RFID tag 24 so that if the vessel 28 is moved to another hob, the
new hob can complete the heating process without requiring
additional input from the user.
Mode 3, which is known in the prior art, is a manual power control
mode that does not employ any RFID information, such that any
induction-suitable vessel or object can be heated in Mode 3. In
Mode 3 the user selects, via the user interface 60, a desired power
output level which is a percentage of the maximum power that the
work coil 46 can generate, as depicted in box 232. In Mode 3 the
induction range 22 operates much like a conventional gas range.
State-of-the-art induction cooktops, such as, for example, the
CookTek C1800, all operate in some fashion in a manual power
control mode.
A feature of Mode 3 in the present invention which is not disclosed
in the prior art is that if any vessel having an RFID tag and an
appropriate class-of-object code is placed on the hob 44, the hob
44 will automatically leave Mode 3 and enter Mode 1 and execute an
appropriate procedure, as depicted in box 234. This feature
attempts to prevent the user from inadvertently employing Mode 3
with a vessel that they mistakenly believe will achieve automatic
temperature regulation in that mode. Other mechanisms to prevent
the user from inadvertently employing Mode 3 may also employed in
the present invention, including, for example, requiring that the
user enter Mode 3 from Mode 2. This prevents the user from
accidentally entering directly into Mode 3. Another such mechanism
is an automatic "no-load" reversion to Mode 1, wherein if no
suitable load is detected over the work coil 46 for a
pre-programmed amount of time, such as, for example, approximately
between 30 seconds and 2 minutes, while a hob 44 is in Mode 3, then
the microprocessor 48 will automatically revert to Mode 1.
From the preceding description, it will be appreciated that the
cooking and heating system 20 of the present invention provides a
number of substantial advantages over the prior art, including, for
example, providing for precisely and substantially automatically
controlling a temperature of a vessel 28 that has an attached RFID
tag 24. Furthermore, the present invention advantageously allows a
user to select the desired temperature of the vessel 28 from a
wider range of temperatures than is possible in the prior art. The
present invention also advantageously provides for automatically
limiting heating of the vessel 28 to a pre-established maximum safe
temperature. The present invention also provides for automatically
heating the vessel 28 to a series of pre-selected temperatures for
pre-selected elapsed times. Additionally, the present invention
advantageously ensures that any of several hobs 44 are able to
continue the series of pre-selected temperatures and pre-selected
elapsed times per temperature even if the vessel 28 is moved
between hobs 44 during execution of the series. The present
invention also advantageously provides for compensating for any
elapsed time in which the vessel 28 was removed from the range
during the series, including, when necessary, restarting the
process at an appropriate point in the recipe. Additionally, the
present invention advantageously provides for exceptionally fast
thermal recovery of the vessel 28 to the selected temperature
regardless of any change in cooling load, such as the addition of
frozen food to hot oil in the vessel 28.
Additionally, the present invention advantageously provides for
reading and storing recipe or other cooking or heating instruction
from food packages, recipe cards, or other items. The recipe may be
stored in an RFID tag on the item and may define the aforementioned
series of pre-selected temperatures for pre-selected elapsed times.
The present invention also advantageously provides for writing the
recipe or other instructions to the RFID tag 24 of the vessel 28,
thereby allowing execution of the recipe to continue even after the
vessel 28 has been moved to another hob into which the recipe was
not initially entered. The present invention also advantageously
provides for interactive assistance, including prompting, in
executing the recipe or other instructions.
Although the invention has been described with reference to the
preferred embodiment illustrated in the attached drawings, it is
noted that equivalents may be employed and substitutions made
without departing from the scope of the invention as recited in the
claims.
Having thus described the preferred embodiment of the invention,
what is claimed as new and desired to be protected by Letters
Patent includes the following:
* * * * *
References