Food warming apparatus and method

• US 7,105,779 B2
• Filed: 10/07/2003
• Issued: 09/12/2006
• Est. Priority Date: 07/10/2002
• Status: Expired due to Fees

• Current Assignee: Duke Manufacturing Company
• Original Assignee: Duke Manufacturing Company
• Inventors: Shei, Steven M.
• Primary Examiner(s): Campbell, Thor S.
• Application Number:
  US10/680,626
• Publication Number:
  US 20040069155A1
• Time in Patent Office: 1,071 Days
• Field of Search: 219/394, 219/400, 219/411, 219/412, 219/414, 219/492, 219/493, 993/87, 999/78, 994/83, 994/74, 994/76
• US Class Current: 219/413
• CPC Class Codes: A21B 1/22 by electric radiators A21B2/00 takes precedence
• CPC Class Codes: A21B 2/00 Baking apparatus employing high-frequency or infrared heating
• CPC Class Codes: A47J 39/003 with forced air circulation
• CPC Class Codes: F24C 7/06 Arrangement or mounting of electric heating elements
• CPC Class Codes: F24C 7/087 of electric circuits regulating heat

Abstract

In general, one embodiment of the invention is directed to food holding apparatus for holding pre-cooked food at a selected holding temperature. The apparatus comprises a cabinet having at least one holding compartment therein, and pre-cooked food in the holding compartment, the food having been previously cooked in a cooking appliance. At least one radiant heat source is spaced above the food a distance less than 12 inches for delivering radiant heat to the food. A control mechanism varies the amount of radiant heat delivered by the heat source to the food to maintain the food at the selected holding temperature. A related method is also disclosed.

Claims

1. Food holding apparatus for holding pre-cooked food at a selected holding temperature, said apparatus comprising:

a cabinet having at least one holding compartment therein;

pre-cooked food in the holding compartment, said food having been previously cooked in a cooking appliance;

at least one infrared heat source spaced above the food a distance less than 12 inches for delivering infrared heat to the food;

said infrared heat source being selected from the group of (i) ceramic infrared heat source, (ii) halogen infrared heat source, (iii) quartz infrared heat source, and (iv) infrared heat lamp; and

a control mechanism for varying the amount of infrared heat delivered by the infrared heat source to the food during a duration of holding time to maintain the food at said selected holding temperature.

2. Food holding apparatus as set forth in claim 1 wherein said control mechanism is programmed to operate said at least one infrared heat source in successive time-based cycles.

3. Food holding apparatus as set forth in claim 1 wherein each of said time-based cycles comprises a first time interval during which the at least one infrared heat source is activated to deliver infrared heat and a second time interval during which the heat source is not activated.

4. Food holding apparatus as set forth in claim 1 wherein said distance is less than 6 in.

5. Food holding apparatus as set forth in claim 1 wherein said distance is less than 4 in.

6. Food holding apparatus as set forth in claim 1 wherein said distance is less than 2 in.

7. Food holding apparatus as set forth in claim 1 further comprising a glass panel between said at least one infrared heat source and said pre-cooked food.

8. Food holding apparatus as set forth in claim 1 wherein said distance is in the range of 0.25-8 in.

9. Food holding apparatus as set forth in claim 1 wherein said distance is in the range of 0.25-6 in.

10. Food holding apparatus as set forth in claim 1 wherein said distance is in the range of 0.25-4 in.

11. Food holding apparatus as set forth in claim 1 wherein said distance is in the range of 0.25-2 in.

12. Food holding apparatus as set forth in claim 1 further comprising partitions in the cabinet dividing the cabinet into a plurality of separate holding compartments, at least one tray in each of said holding compartments holding pre-cooked food therein, at least one infrared heat source spaced above the pre-cooked food in said tray a distance less than 12 inches for delivering infrared heat to the food, and said control mechanism being adapted for controlling operation of the heat sources independent of one another whereby the temperature in each compartment may be independently controlled.

13. Food holding apparatus as set forth in claim 1 wherein said control mechanism is operable to vary the infrared heat delivered by said at least one heat source to the food through a duration of holding time, said duration comprising a first phase at which infrared heat is delivered to the food by the heat source at a first level to permit said pre-cooked food to cool down to said selected holding temperature, and a second phase at which infrared heat is delivered to the food by the heat source at a second level higher than said first level to hold the food at said selected holding temperature.

14. Food holding apparatus as set forth in claim 13 wherein said duration of holding time further comprises a third phase at which infrared heat is delivered to the food at a third level less than said second level to maintain said pre-cooked food at said holding temperature.

15. Food holding apparatus as set forth in claim 1 wherein said control mechanism comprises at least one sensor in the compartment for detecting a characteristic indicative of the temperature of the pre-cooked food in the compartment, the control mechanism being responsive to signals from said sensor to vary the amount of infrared heat delivered by the heat source to the food to maintain the food at said selected holding temperature.

16. Food holding apparatus as set forth in claim 15 wherein said sensor is a temperature sensor for detecting the temperature of a surface in the compartment.

17. Food holding apparatus as set forth in claim 15 wherein said sensor is operable to detect infrared energy emitted by said pre-cooked food.

18. Food holding apparatus as set forth in claim 1 wherein said control mechanism is programmed to operate said heating source according to a predetermined protocol to vary said infrared energy delivered to said food depending on the type of pre-cooked food placed in the compartment.

19. A food holding oven for holding pre-cooked food at a selected food holding temperature, said food holding oven comprising:

a cabinet having a front, a back, and an interior space;

a plurality of separate, thermally isolated holding compartments in the interior space of the cabinet for holding pre-cooked food, said holding compartments comprising a first row of compartments and a second row of compartments, the first row being arranged above the second row;

each compartment having an open front end at the front of the cabinet for placement of the pre-cooked food in the compartment and removal of said pre-cooked food from the compartment;

at least one infrared heat source for delivering infrared heat to the pre-cooked food; and

a control mechanism for varying the amount of infrared heat delivered by said at least one infrared heat source to the pre-cooked food during a duration of holding time to maintain the pre-cooked food at said selected holding temperature.

20. A food holding oven as set forth in claim 19 wherein each compartment receives a tray for holding the pre-cooked food and has an open back end at the rear of the cabinet for placement of a respective tray in the compartment and removal of said tray from the compartment.

21. A food holding oven as set forth in claim 19 wherein the front ends of said compartments are doorless and remain open during a heating operation.

22. A food holding oven as set forth in claim 19 wherein said control mechanism is operable to vary the infrared heat delivered by said at least one heat source to the pre-cooked food through a duration of holding time, said duration comprising a first phase at which infrared heat is delivered to the pre-cooked food by the heat source at a first level to permit said pre-cooked food to cool down to said selected holding temperature, and a second phase at which infrared heat is delivered to the pre-cooked food by the heat source at a second level higher than said first level to hold the pre-cooked food at said selected holding temperature.

23. A food holding apparatus as set forth in claim 22 wherein said duration of holding time further comprises a third phase at which infrared heat is delivered to the pre-cooked food at a third level less than said second level to maintain said pre-cooked food at said holding temperature.

24. A food holding oven as set forth in claim 19 where in said control mechanism is programmed to operate said heat source according to a predetermined protocol to vary the amount of infrared heat delivered to the pre-cooked food depending on the type of pre-cooked food placed in the compartment.

25. A food holding oven as set forth in claim 19 wherein said control mechanism comprises an operator input device for selecting a type of pre-cooked food placed in a respective compartment, and wherein said control mechanism is programmed to operate a respective heat source to heat the pre-cooked food in said respective compartment to a pre-programmed selected holding temperature and to hold the pre-cooked food at said pre-programmed selected holding temperature.

26. A food holding oven as set forth in claim 19 wherein said infrared heat source is selected from the group of (i) ceramic infrared heat source, (ii) halogen infrared heat source, (iii) quartz infrared heat source, and (iv) infrared heat lamp.

27. A food holding oven as set forth in claim 19 wherein said control mechanism controls the operation of the heat sources independent of one another whereby the food holding temperature in each compartment may be independently controlled.

28. A food holding oven as set forth in claim 19 wherein said control mechanism is programmed to operate said infrared heat source in successive time-based cycles.

29. A food holding oven as set forth in claim 28 wherein each of said time-based cycles comprising a first time interval during which the heat source is activated to deliver infrared heat and a second time interval during which the heat source is not activated.

30. A food holding oven as set forth in claim 19 further comprising a glass panel between said infrared heat source and said pre-cooked food.

31. Food holding apparatus for holding pre-cooked food at a selected holding temperature, said apparatus comprising:

a cabinet having at least one holding compartment therein;

pre-cooked food in the holding compartment, said food having been previously cooked in a cooking appliance;

at least one infrared heat source spaced above the food a distance less than 12 inches for delivering infrared heat to the food; and

a control mechanism programmed for operating said at least one infrared heat source in successive time-based cycles during a duration of holding time to maintain the food at said selected holding temperature.

32. Food holding apparatus as set forth in claim 31 wherein each of said time-based cycles comprising a first time interval during which the at least one infrared heat source is activated to deliver infrared heat and a second time interval during which the heat source is not activated.

33. Food holding apparatus as set forth in claim 32 wherein said control mechanism is further programmed for varying a length of said firt time interval from one time-based cycle to another time-based cycle.

34. Food holding apparatus for holding pre-cooked food at a selected holding temperature, said apparatus comprising:

a cabinet having at least one holding compartment therein;

pre-cooked food in the holding compartment, said food having been previously cooked in a cooking appliance;

at least one infrared heat source spaced above the food a distance less than 12 inches for delivering infrared heat energy directly to the food;

said infrared heat source being selected from the group of (i) ceramic infrared heat source, (ii) halogen infrared heat source, (iii) quartz infrared heat source, (iv) resistance heating element embedded in magnesium oxide, and (v) infrared heat lamp; and

p1 a control mechanism for varying the amount of infrared heat energy delivered by the infrared heat source to the food during a duration of holding time to maintain the food at said selected holding temperature.

35.Food holding apparatus as set forth in claim 34 further comprising a panel transparent to said infrared heat energy positioned between said at least one heat source and said pre-cooked food.