Holding or cooking oven

Abstract

An oven for maintaining cooked foods at temperatures suitable for serving the foods or even for cooking foods has a cabinet containing multiple heat sinks of channel-shaped configuration. The ends of the heat sinks open out of the cabinet, so that any heat sink may receive a tray of food from either the front or back of the cabinet. The interior surface of the heat sinks generally conform to the cross-sectional shapes of the trays, so that the heat sinks lie along the bottoms and sides of the trays. The heat sinks have a heating elements extended along their sides and bottoms for elevating the temperature of the heat sinks and directing heat into the trays within the heat sinks. In addition, each heat sink also contains a cover which may close the top of the tray in the heat sink and thereby retard the escape of moisture from the tray or may vent the interior of the tray. In other embodiments, the oven includes a cabinet having a plurality of compartments therein, and a plurality of trays in the compartments, each compartment being sized for receiving only one tray per compartment. The compartments are isolated from one another in the cabinet whereby flavor from food in one tray in one compartment is prevented from transferring to food in trays in adjacent compartments.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 09/756,941, filed Jan. 9, 2001 (on which U.S. Pat. No. 6,262,394 will issue on Jul. 17, 2001), which is a division of application Ser. No. 09/538,761, filed Mar. 30, 2000, (on which U.S. Pat. No. 6,175,099 issued on Jan. 16, 2001), which is a continuation-in-part of application Ser. No. 09/282,313 filed Mar. 31, 1999, (now abandoned).

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable.

BACKGROUND OF THE INVENTION

This invention relates in general to ovens and more particularly to an oven for maintaining foods at temperatures suitable for serving or even for cooking foods.

Most restaurants which specialize in serving cooked food rapidly—indeed, essentially with the placement of an order—do not have the capacity to prepare large quantities of food on demand. Thus, traditional meal times, particularly the noon hour, place severe demands on these restaurants. Typically, the so-called “fast food” restaurant will prepare some cooked food in advance of a meal time and keep that food warm in a holding oven. Then, during a meal time when the demand is greatest, it will use the food previously cooked.

Some cooked foods, such as hamburger patties, should be held at elevated temperatures only in a moist environment, since these foods, when depleted of their moisture content have poor taste and texture. Other cooked foods, such as breaded chicken or fish fillets, should be stored such that moisture may escape, so that they remain crisp. While it is convenient to store different foods at the same location, the flavor of one food should not transfer to another food. Moreover, irrespective of the food, the temperature at which it is stored must remain high enough to prevent bacterial contamination, and this generally requires holding the food at temperatures in excess of about 150° F. Holding ovens that are currently in use in fast food restaurants do not fully satisfy these requirements.

The holding ovens of current manufacture accept trays containing the cooked foods. The typical oven has a cabinet containing storage spaces which are accessible from both the front and rear of the cabinet, so that a tray containing cooked food may be placed into a storage space at one face of the cabinet and withdrawn at the other face. Each storage space has a heated platen along its top and also preferably at its bottom, and these platens transfer heat to the trays. The cabinet also contains a mechanism for closing the upper ends of the trays to prevent moisture from escaping. In one type of holding oven this mechanism resides in making the spacing between a heated platen on which the tray rests and the heated platen which overlies the tray about equal to the height of the tray, so that the upper margin of the tray lies along and essentially against the overlaying platen, thus in effect closing the tray. See U.S. Pat. No. 5,724,886. Another type of holding oven supports the tray on a resilient grate which urges a tray upwardly against an overlying heated platen, thereby effecting a seal with the overlying platen. See U.S. Pat. No. 5,783,803. These ovens are difficult to clean and do not efficiently concentrate the heat at the trays where it is needed. As a consequence, the food is often held at a temperature less than optimum. Sometimes, the spaces in these ovens hold trays with their tops open and this leads to a transfer of flavors between multiple trays in any one space. In any event, ovens of current manufacture have the capacity to store foods for only very limited periods of time.

BRIEF SUMMARY OF THE INVENTION

The present invention resides in an oven having a channel-shaped heat sink which is heated by a heater. The heat sink has a storage cavity which generally conforms to the shape of a tray or other food container received in the cavity. As such, the heat sink concentrates the heat generated by the heater at the tray so as to efficiently maintain the food in the tray at a temperature suitable for serving. The heat sink may have a cover for closing the top of the tray within it. Where the oven contains multiple heat sinks, these heat sinks are isolated from each other to prevent the flavor of the food in one from transferring to food in another.

separate compartments in the cabinet 26, even when the covers 80 over those trays are in their venting positions, flavors are not transferred between the foods in different trays B. In one embodiment (FIGS. 3 and 4), each compartment is defined by bottom wall 50, side walls 52, and top wall 38 and is sized for receiving only one tray B per compartment.

A modified cover 100 (FIG. 6) has side legs 82 and a cross wall 84 of essentially the same configuration as their counterparts in the cover 80. However, the cross wall 84 contains openings 102 arranged in a row between the legs 82. It also carries a slide 104 which likewise contains openings 106. The slide 104 is captured on the cross wall 84 such that it cannot be lifted from the cross wall 84, yet it can slide longitudinally over the wall 84. Indeed, the slide 104 projects beyond the ends of the cross wall 84, so that it can be manipulated from the exterior of the oven A to assume various positions on the cross wall 84. In one position, the slide completely covers the openings 102 in the wall 84, and in this position the tray B is sealed. In other positions the slide 104 exposes the openings 102 in the wall 84 through its own openings 106, with the amount of exposure being dependent in the position of the slide 104. In these positions the tray B is vented.

A modified tray C (FIG. 7) may be used in the heat sinks 46 to keep foods warm, and it is similar to the tray B in all respects, except the provision for removing it from and inserting it into the heat sink 46. Whereas the tray B has handles 20 that are generally flat and extend the full width of the tray B, the tray C has handles 108 that are narrow and resemble the handles on household frying or sauce pans. The handles 108 project from the end walls 6 of the tray C where they are located near the peripheral lip 14, but are otherwise centered between the side walls 4.

Another modified cover 110 (FIGS. 7 & 8) works well with the tray C, but is also suitable for use with the tray B. The cover 110 has legs 112 and a cross wall 114 extending horizontally between the legs 112 to which it is attached. The legs 112 do not differ from the legs 82 of the cover 80, and they rest on the horizontal shoulders 70 of the heat sink 46, even when the tray C is in the cavity 48 of the heat sink 46. Moreover, they extend up to and nearly contact the pan 38 that overlies the heat sink 46 in the cabinet 36. The cross wall 114 has an elevated region 116 where it is joined to the legs 112 and a depressed region 118 located within and being joined to the elevated region 116. The depressed region 118 has a peripheral wall 120 that is generally vertical and a bottom wall 122 which lies below, yet parallel to, the surrounding elevated region 116.

When the tray C is in the cavity 48 of the heat sink 46 (FIG. 8), the bottom surface of the elevated region 116 in the cross wall 114 lies directly above the upper surface 18 on the tray B, there being a gap of about 0.375 in. between the two surfaces. The peripheral wall 120, on the other hand, is set inwardly from the upper surface 18 of the tray C and inwardly from the upper ends of the side walls 4 and end walls 6 as well, with the gap being about 0.375 in. The lower surface of the bottom wall 122 lies in a horizontal plane that is slightly above the plane defined by the upper surface 18 on the tray C, with the spacing between the two planes being about 0.01 in. This spacing allows the tray C to be inserted into and removed from the cavity 48 of the heat sink 46 without interference from the cover 110.

At the ends of the cover 110 the elevated region 116 of the cross wall 114 turns downwardly in the form of a vertical lip 124, the lower edge of which lies in the plane of the lower surface on the bottom wall 122. When the tray C is in the heat sink 46, the lips 124 lie slightly beyond the upper surfaces 18 at the ends of the tray C, yet over or slightly beyond the depressed edges 16 at those ends. The lips 124 and the nearby segments of the peripheral wall 120 for the depressed region 118 create labyrinths which retard moisture from escaping from the tray C.

To enhance the seal established by the lips 124 and the depressed region 118 of the cover 110, the lips 124 may be fitted with elastomeric seal elements which bear against the end edges of the laterally directed lip 14 of the tray C beyond the two end walls 6 of the tray C. Likewise, elastomeric lip seals may also be fitted to the ends of the cross wall for the cover 80 to contact the lip 14 at the ends of the tray C and thereby enhance the sealing capabilities of the cover 80.

The rear panel 30 of the cabinet 26, in lieu of having openings 36, may be solid. In such an arrangement the rear panel 30 would block one end of the cavity 48 for each heat sink 46, and the heat sink 46 itself could wrap around the end of the cavity to close it and thus, transfer heat to that end wall 6 of the tray B which is presented toward the closed end. The other end of the heat sink 46 would remain open and indeed would open out of the cabinet 36 through the aligned opening 36 in the front panel 28. Of course, the handle 20 on that end of the tray B which faces the closed end of the heat sink 46 would have to be removed or reconfigured, so that it will not interfere with the solid rear panel 30.

Also, any tray B or C which must retain moisture may be fitted with a separate cover, and that would eliminate the need for the covers 80 or 110. In this regard, covers are available on the market for the traditional trays that resemble the trays B and C.

This invention is intended to cover all changes and modifications of the example of the invention herein chosen for purposes of the disclosure which do not constitute departures from the spirit and scope of the invention.

Duke Manufacturing Company

Re: HOLDING OR COOKING OVEN
A	oven	50	bottom wall
B	trays	52	side walls
C	tray	54	flat bottom surface
2	bottom wall	56	flat top surface
4	side walls	58	lower region
6	end walls	60	flat outside surface
8	corners	52	contoured inside surface
10	offset portion	64	curved corner
14	lip	66	upper region
16	depressed edge	68	offsets
18	upper surface	70	flat horizontal shoulders
20	handles	76	heating element
22		78	thermal insulation
24		80	cover
26	cabinet	82	legs
28	front panel	84	cross wall
30	rear panel	88	stops
32	end panels	90
34	top panel	92	electrical controls
36	opening	100	modified cover
38	upper pan	102	openings
40	lower pans	104	slide
41	lips	106	openings
42	channels	108	handles
43	lips	110	modified cover
44	rigidifying members	112	legs
46	heat sink	114	cross wall
48	cavity	116	elevated region
		118	depressed region
		120	peripheral wall
		122	bottom wall
		124	vertical lip

Claims

1. In combination with a heating device and with a tray located within the heating device and having a rim that is presented upwardly around the interior of the tray, a self-supporting cover for establishing at least a partial closure over the rim of the tray, said cover comprising: first and second legs in an upright orientation and having lower margins for supporting the cover, the legs being spaced far enough apart to receive the rim of the tray between them; and a cross wall attached to the legs above their lower margins and extending between the legs, the space between the legs and below the cross wall being open at at least one end of the cover, so that the rim of the tray may be inserted between the legs and below the cross wall at that end of the cover.

2. The combination according to claim 1 wherein the legs also have upper margins, and the cover is attached to the legs intermediate the upper and lower margins of the legs.

3. The combination according to claim 1 wherein the space between the legs and below the cross wall is open at both ends of the cover.

4. The combination according to claim 1 wherein the cross wall, where space between the legs and below the cross wall is open, flares upwardly.

5. The combination according to claim 1 wherein the rim of the tray is generally rectangular, having ends and sides, with the sides being longer then the ends; and wherein the sides of the rim on the tray are located along the legs of the cover.

6. The combination according to claim 1 wherein the legs of the cover also have upper margins; and wherein the cross wall is attached to each leg intermediate the upper and lower margins for the leg, but closer to one of such margins than the other.

7. The combination according to claim 1 wherein the cross wall of the cover contains at least one opening for venting the interior of the tray.

8. The combination according to claim 7 wherein the cover further includes a slide that moves along the cross wall of the cover between a closed position in which the opening is closed and open positions in which the opening is exposed.

9. The combination according to claim 1 wherein the cross wall of the cover contains a plurality of openings arranged in a row; and wherein the cover further includes a slide which is located along the cross wall and has openings also arranged in a row, the slide being movable along the cross wall between a closed position and open positions, the slide when in its closed position covering the openings in the cross wall and when in its open positions at least partially exposing the openings in the cross wall through the openings in the slide.

10. In combination according to claim 1 wherein the cross wall of the cover contains a plurality of openings sized for venting moisture from the tray.

11. In combination with a heat sink having shoulders and a tray located within the heat sink, a cover for at least partially closing the tray while the tray is in the heat sink, said cover comprising: upright legs which are located over the shoulders of the heat sink and project upwardly away from the shoulders; and a cross wall extending between the legs and the tray.

12. The combination according to claim 11 wherein the legs of the cover are located beyond the rim on the tray.

13. The combination according to claim 11 wherein the legs of the cover are located beyond the rim on the tray and rest on the shoulders of the heat sink, whereby the tray at its nm is between the legs of the cover.

14. The combination according to claim 11 wherein the legs of the cover have lower margins and the cover is attached to the legs above their lower margins; and wherein the space between the legs and below the cover is open at at least one end of the cover so that the tray at its rim may be inserted into and removed from the space below the cross wall on the cover.

15. The combination according to claim 14 wherein the legs have upper margins, and the cross wall is attached to the legs below the upper margins.

16. The combination according to claim 15 wherein the spacing between the upper margins and the cross wall differs from the spacing between the lower margins and the cross wall.

17. The combination according to claim 11 wherein the cross wall of the cover contains at least one opening.

18. The combination according to claim 17 wherein the cover further includes a slide that moves along the cross wall of the cover between a closed position in which the opening is closed and open positions in which the opening is exposed.

19. The combination according to claim 11 wherein the cross wall of the cover contains a plurality of openings arranged in a row; and wherein the cover further includes a slide which is located along the cross wall and has openings also arranged in a row, the slide being movable along the cross wall between a closed position and open positions, the slide when in its closed position covering the openings in the cross wall and when in its open position at least partially exposing the openings in the cross wall through the openings in the slide.

20. An oven comprising:

a cabinet;

a plurality of trays adapted to be inserted in the cabinet and withdrawn from the cabinet, each tray having a bottom wall, side walls extending upwardly from the bottom wall, and an open top;

self-supporting covers in the cabinet for respective trays, each cover having a generally horizontal cross wall and a pair of side walls extending downwardly from the cross wall at opposite sides of the cross wall, said cross wall having a width which exceeds the width of a respective tray to allow the tray to be positioned in the cabinet between the side walls of the cover with the cross wall extending over the open top of the tray;

each cover being releasably retained in the cabinet against withdrawal from the cabinet when a respective tray is removed from between the side walls of the cover and withdrawn from the cabinet, the side walls of the cover supporting the cover in the cabinet after the tray has been withdrawn from the cabinet; and

a heating element positioned in the cabinet to direct heat into trays in the cabinet.

21. An oven as set forth in claim 20 wherein the cross wall of at least one cover has at least one opening in it to vent a tray located beneath the cover.

22. An oven comprising:

a cabinet;

horizontal shoulders in the cabinet;

a plurality of trays adapted to be inserted in the cabinet and withdrawn from the cabinet, each tray having a bottom wall, side walls extending upwardly from the bottom wall, and an open top;

covers in the cabinet for respective trays, each cover having a generally horizontal cross wall and a pair of side walls extending downwardly from the cross wall at opposite sides of the cross wall over respective horizontal shoulders in the cabinet, said cross wall having a width which exceeds the width of a respective tray to allow the tray to be positioned in the cabinet between the side walls of the cover with the cross wall extending over the open top of the tray;

each cover being releasably retained in the cabinet against withdrawal from the cabinet when a respective tray is removed from between the side walls of the cover and withdrawn from the cabinet, the side walls of the cover resting on said respective shoulders after the tray has been withdrawn from the cabinet; and

at least one opening in the cross wall of at least one of said covers for venting the cover.

23. An oven comprising

a cabinet having a plurality of compartments therein,

a plurality of trays in said compartments, eash compartment being sized for receiving only one tray per compartment,

said compartments being isolated from one another in said cabinet whereby flavor from food in one tray in one compartment is prevented from transferring to food in trays in adjacent compartments,

each compartment having open ends for placement of said tray in the compartment and removal of said tray from the compartment, and

a plurality of heaters, each heater being operable for heating a respective compartment.

24. The oven as set forth in claim 23 wherein each compartment has a bottom wall heated by a respective heater.

25. The oven as set forth in claim 24 wherein each compartment has side walls, and wherein said bottom and side walls of each compartment are formed by a unitary member.

26. The oven as set forth in claim 25 wherein said unitary member is generally U-shaped.

27. The oven as set forth in claim 25 wherein said unitary member is a metal heat sink.

28. The oven as set forth in claim 23 further comprising a cover in at least one of said compartments for covering a tray in the compartment.

29. The oven as set forth in claim 28 wherein said cover is a rigid cover supported in a position over the tray.

30. The oven as set forth in claim 29 wherein said cover comprises a generally horizontal cross wall spanning the top of the tray.

31. The oven as set forth in claim 30 wherein said cover comprises a pair of side walls extending vertically from the cross wall at opposite sides of the cross wall.

32. The oven as set forth in claim 29 wherein said at least one compartment has side walls with shoulders for supporting said cover over the tray in the compartment.

33. The oven as set forth in claim 32 wherein the side walls of said at least one compartment are spaced apart approximately 1 inch greater than a width of said respective tray.

34. The oven as set forth in claim 23 wherein said heaters also heat side walls of the compartments.

35. The oven as set forth in claim 23 further comprising a control for controlling the operation of the heaters.

36. The oven as set forth in claim 35 wherein said control controls the operation of at least one group of heaters independently of another group of heaters.

37. The oven as set forth in claim 35 wherein said control controls the operation of each heater independently of the other heaters.

38. An oven as set forth in claimm 23 wherein said plurality of compartments includes side-by-side compartments.

39. An oven comprising

a cabinet having a plurality of compartments therein,

a plurality of trays in said compartments, each compartment being sized for receiving only one tray per compartment,

said compartments being isolated from one another in said cabinet whereby flavor from food in one tray in one compartment is prevented from transferring to food in trays in adjacent compartments,

each compartment having open ends for placement of said tray in the compartment and removal of said tray from the compartment,

a plurality of heaters for heating said plurality of compartments, the operation of each of said plurality of heaters being controlled independently of the other heaters.

40. An oven as set forth in claim 39 wherein each of said plurality of compartments has one of said plurality of heaters adjacent thereto for heating the compartment.

41. An oven as set forth in claim 40 further comprising a cover in at least one of said plurality of compartments for covering a tray in the compartment.

42. An oven as set forth in claim 41 wherein said at least one of said plurality of compartments has side walls with shoulders for supporting said cover over a tray in the compartment.

43. An oven as set forth in claim 39 wherein said plurality of compartments includes side-by-side compartments.

44. An oven comprising

a cabinet having a plurality of compartments therein,

a plurality of trays in said compartments, each compartment being sized for receiving only one tray per compartment,

said compartments being isolated from one another in said cabinet whereby flavor from food in one tray in one compartment is prevented from transferring to food in trays in adjacent compartments,

each compartment having open ends for placement of said tray in the compartment and removal of said tray from the compartment,

a plurality of heaters for heating said plurality of compartments, each compartment being heated by one of said plurality of heaters located adjacent the compartment,

the operation of at least one group of said plurality of heaters being controlled independently of another group of said plurality of heaters, and

a cover in at least one of said plurality of compartments for covering a tray in the compartment.

45. An oven as set forth in claim 44 wherein said at least one of said plurality of compartments has side walls with shoulders for supporting said cover over a tray in the compartment.

46. An oven as set forth in claim 44 wherein said plurality of compartments includes side-by-side compartments. An oven as set forth in claim 42 wherein said at least one of said plurality of compartments has side walls with shoulders for supporting said cover over a tray in the compartment.