APPARATUS FOR COOKING FOOD

Abstract

Apparatus (10) for cooking food comprising: at least one heating stage (30, 40); a conveyor system (50) defining a predetermined path (60) extending from a loading region (70), through the at least one heating stage (30, 40), and onward to an unloading region (80); and means (100) for releasably holding food on the conveyor system (50) as the food on the conveyor system is transported through the at least one heating stage (30, 40).

Claims

1. Apparatus for cooking food comprising: at least one heating stage; a conveyor system defining a predetermined path extending from a loading region, through the at least one heating stage, and onward to an unloading region; and means for releasably holding food on the conveyor system as the food on the conveyor system is transported through the at least one heating stage.

2. Apparatus according to claim 1, wherein the apparatus is configured to release the food from the conveyor system automatically upon reaching the unloading region.

3. Apparatus according to claim 1 or claim 2, wherein the predetermined path comprises a substantially vertical section extending through the at least one heating stage and the conveyor system is configured to convey food along the substantially vertical section.

4. Apparatus according to claim 3, wherein the means for releasably holding food comprises first and second conveyor surfaces defined by the conveyor system, the first conveyor surface being operative to engage a first surface of the food and the second conveyor surface being operative to engage a second surface of the food.

5. Apparatus according to claim 4, wherein the first conveyor surface is defined by a primary conveyor operative to convey food along the predetermined path and the second conveyor surface is defined by a secondary conveyor operative to move along a second path.

6. Apparatus according to claim 5, wherein the primary and secondary conveyors meet at a start point of the vertical section and separate at an end point of the vertical section.

7. Apparatus according to claim 5 or claim 6, wherein at least one of the primary and secondary conveyors comprise a wire mesh belt conveyor.

8. Apparatus according to any of claims 3-7, wherein at least one of the first and second conveyor surfaces comprise food gripping elements.

9. Apparatus according to any of claims 1-3, wherein the means for releasably holding food comprises at least one food-holder support, the at least one food-holder support being operative to support a food holder used to hold an item of food as the at least one food-holder support is conveyed by the conveyor system from the loading region to the unloading region via the at least one heating stage.

10. Apparatus according to claim 9, wherein the apparatus is configured to automatically release the food holder when the at least one food-holder support reaches a predetermined release orientation.

11. Apparatus according to claim 9 or claim 10, wherein the at least one food-holder support comprises one or more hook elements configured to receive part of a food holder.

12. Apparatus according to claim 11, wherein the at least one food-holder support comprises first and second laterally spaced hook elements.

13. Apparatus according to claim 11 or claim 12, wherein the or each hook element comprises first and second jaw members spaced to define an opening configured to receive a portion of a food holder.

14. Apparatus according to claim 13, wherein at least one of the first and second jaw members defines a protuberant lip configured to retain the food holder in the hook element as the hook element pivots over a predetermined angle range.

15. Apparatus according to claim 13 or claim 14, wherein the first jaw member defines a first protuberant lip configured to retain the food holder in the hook element as the hook element pivots between a first advancement orientation and a second advancement orientation.

16. Apparatus according to claim 15, wherein one of the first and second advancement orientations comprises a loading orientation.

17. Apparatus according to any of claims 13-16, wherein the second jaw member defines a second protuberant lip configured to retain the food holder in the hook element as the hook element pivots between the second advancement orientation and a third advancement orientation.

18. Apparatus according to any of claims 11-17, wherein the hook element is configured to release a held food holder as the hook element pivots into an unloading orientation.

19. Apparatus to any of claims 13-18, wherein the or each hook element is configured to maintain a predetermined orientation relative to the conveyor system such that the opening is always facing a predetermined direction relative to the direction of travel of the conveyor system.

20. Apparatus according to any of claims 11-19, wherein the or each hook element is configured to maintain a predetermined substantially perpendicular orientation such that the opening is always facing substantially perpendicular to the direction of travel.

21. Apparatus according to any of claims 9-20, wherein the apparatus further comprises at least one guide element operative to maintain a food holder in a predetermined orientation and/or position relative to the at least one food-holder support as the at least one food-holder support moves relative to the at least one guide element.

22. Apparatus according to any of claims 9-21, wherein the at least one food-holder support is a skewer support operative to support a skewer or food holder with a skewer support mountable profile.

23. Apparatus according to claim 22, wherein the food-holder support is operative to support a basket with mounting profiles extending from opposed ends of the basket.

24. Apparatus according to any of the preceding claims, wherein the conveyor system comprises a conveyer chain system comprising at least one chain and a chain drive mechanism operative to drive movement of the at least one chain.

25. Apparatus according to claim 24 when dependent upon any of claims 9-23, wherein the at least one food-holder support is integrally formed as part of a link plate of the at least one chain.

26. Apparatus for cooking food comprising: a heat source defining an upright heating surface, wherein the upright heating surface comprises: an upper heating zone extending from a midway section of the upright heating surface to an uppermost section of the upright heating surface; and a lower heating zone positioned below the upper heating zone and extending from the midway section of the heat surface to a lowermost section of the upright heating surface; wherein the upper heating zone is configured to provide a lower heat output density in power per unit area than the lower heating zone when both the upper heating zone and lower heating zone are activated to generate heat.

27. Apparatus according to claim 26, wherein the upright heating surface extends in a substantially vertical plane.

28. Apparatus according to claim 26 or claim 27, wherein the heat source is a radiant burner comprising at least one burner plate forming at least a part of the upright heating surface and a gas supply inlet operative to supply fuel or mixed air/fuel to the at least one burner plate.

29. Apparatus according to claim 28, wherein: the at least one burner plate comprises at least one active burner plate section; and the upright heating surface comprises the at least one active burner plate section and at least one spacer section adjacent the at least one active burner plate section.

30. Apparatus according to claim 29, wherein the at least one burner plate comprises a plurality of n active burner plate sections each active burner plate section being spaced vertically from a neighbouring active burner plate section by one of p spacer sections.

31. Apparatus according to claim 30, wherein n3 and p=n1.

32. Apparatus according to claim 31, wherein the plurality of n active burner plate sections are configured to provide substantially equal heat output.

33. Apparatus according to any of claims 30-32, wherein at least one of the p spacer sections is located in the upper heating zone and at least one of the p space sections is located in the lower heating zone, wherein the at least one spacer section located in the upper heating zone provides a vertical spacing that is greater than the vertical spacing provided by the at least one spacer section located in the lower heating zone.

34. Apparatus according to any of claims 30-33, wherein each of the n active burner plate sections are connected to at least one neighbouring active burner plate section by at least one vertically extending active burner plate strip.

35. Apparatus according to claim 34, wherein the at least one vertically extending active burner plate strip comprises a pair of laterally opposed active burner plate side strips.

36. Apparatus for cooking food comprising: a rotatable food support operative to rotate about a rotary axis; and a heat source; wherein the heat source comprises a concave curved heating surface facing the rotatable food support.

37. Apparatus according to claim 36, wherein the rotary axis extends in a substantially vertical direction.

38. Apparatus according to claim 36 or claim 37, wherein the concave curved heating surface is a concave part-cylindrical surface.

39. Apparatus according to any of claims 36-38, wherein the heat source a main heating section and at least one auxiliary heating section operative when activated to extend the effective length of the concave curved heating surface.

40. Apparatus according to any of claims 36-39, wherein the heat source comprises a radiant burner comprising at least one burner plate and a gas supply inlet operative to supply fuel or mixed air/fuel to the at least one burner plate.

Description

[0137] Embodiments of the invention will now be described in detail, by way of example, with reference to the accompanying drawings, in which:

[0138] FIG. 1 is a schematic perspective view of apparatus for cooking food in accordance with an embodiment of the present invention;

[0139] FIG. 2A is a schematic detailed perspective view of chain and food-holder support elements of the apparatus of FIG. 1;

[0140] FIG. 2B is a schematic side view of the chain and food-holder support elements illustrated in FIG. 2A;

[0141] FIG. 3A is a schematic side view of the apparatus of FIG. 1 illustrating rotational the orientation of one food-holder support element as it moves along the conveyer system;

[0142] FIGS. 4A-C are schematic plan, side and edge views of a first type of skewer suitable for use with the apparatus of FIG. 1;

[0143] FIG. 5A-D are schematic representations of the skewer of FIGS. 4A-C when mounted in a food-holder support element of the apparatus of FIG. 1 in the various rotational orientations;

[0144] FIGS. 6A-C are schematic plan, side and edge views of a second type of skewer suitable for use with the apparatus of FIG. 1;

[0145] FIG. 7A-D are schematic representations of the skewer of FIGS. 6A-C when mounted in a food-holder support element of the apparatus of FIG. 1 in the various rotational orientations;

[0146] FIG. 8A is a schematic front view of apparatus for cooking food in accordance with a second embodiment of the present invention;

[0147] FIG. 8B is a schematic cross-sectional view of the apparatus of FIG. 8A;

[0148] FIG. 8C is a schematic end view of the apparatus of FIG. 8A;

[0149] FIG. 9A is a schematic side view of chain and food-holder support elements of the apparatus of FIG. 8A;

[0150] FIG. 9B is a schematic end view of the chain and food-holder support elements illustrated in FIG. 9B;

[0151] FIG. 10A is a schematic representation of the skewer of FIGS. 4A-C when mounted in a food-holder support element of the apparatus of FIG. 8A in the various rotational orientations;

[0152] FIG. 10A is a schematic representation of an alternative skewer when mounted in a food-holder support element of the apparatus of FIG. 8A in the various rotational orientations;

[0153] FIG. 11A is a schematic front view of apparatus for cooking food in accordance with a third embodiment of the present invention illustrated in use cooking skewered food;

[0154] FIG. 11B is a schematic cross-sectional view of the apparatus of FIG. 11A illustrated in use cooking skewered food;

[0155] FIG. 11C is a schematic end view of the apparatus of FIG. 11A illustrated in use cooking skewered food;

[0156] FIG. 11D is a schematic front view of the apparatus of FIG. 11A illustrated in use cooking food in baskets;

[0157] FIG. 11E is a schematic cross-sectional view of the apparatus of FIG. 11A illustrated in use cooking food in baskets;

[0158] FIG. 11F is a schematic end view of the apparatus of FIG. 11A illustrated in use cooking food in baskets;

[0159] FIG. 12A is a schematic front view of apparatus for cooking food in accordance with a fourth embodiment of the present invention;

[0160] FIG. 12B is a schematic cross-sectional view of the apparatus of FIG. 12A;

[0161] FIGS. 13A-H are alternative examples of food-holder support elements for use in the cooking apparatus of FIGS. 1, 8A and 11A;

[0162] FIG. 14 is a schematic front view of a gas burner in accordance with a further embodiment of the invention for use in the cooking apparatus of FIGS. 1, 8A, 11A and 12A;

[0163] FIG. 15A is a schematic plan view of a vertical rotisserie in accordance with a yet further embodiment of the invention; and

[0164] FIG. 15B is a schematic front view of a gas burner of the vertical rotisserie of FIG. 15A.

[0165] FIGS. 1-3 illustrate details of a semi-automated cooking apparatus 10 for cooking skewered food comprising a base unit 20 supporting: first and second vertical heating stages 30, arranged in series; an endless conveyor chain system 50 defining a predetermined path 60 extending from a loading region 70, through the first and second vertical heating stages 30, 40, and onward to an unloading region 80; and a plurality of food-holder supports (or skewer supports) 100 integrally formed with the chain conveyor system 50.

[0166] Conveyer chain system 50 comprises first and second laterally spaced roller chains 52 driven by a common chain drive mechanism 54.

[0167] Chain drive mechanism 54 comprises a plurality of drive shafts 54A each supporting end sprockets 54B operative to engage first and second roller chains 52 at a plurality of points along the predetermined path 60 and drive synchronous circulation of the roller chains 52. As illustrated in FIG. 3, path 60 defined by conveyer chain system 50 comprises in sequence: a loading path (horizontal path section 60a); a first heating path (upward vertical path section 60b); a connecting path (horizontal path section 60c); a second heating path (downward vertical path section 60d); and an unloading path (horizontal path section 60e extending in an opposed direction to path sections 60a and 60c).

[0168] Each skewer support 100 comprises first and second laterally spaced hook elements 110 configured to receive opposed end parts of a skewer 150, 150.

[0169] First vertical heating stage 30 comprises a first pair of opposed gas burners 32A, 32B defining first and second heating surfaces 34A, 34B with a first heating path (vertical upward path section 60b) extending therebetween. Second vertical heating stage 40 comprises a second pair of opposed gas burners 42A, 42B defining first and second heating surfaces 44A, 44B with a second heating path (vertical downward path section 60d) extending therebetween. Gas burners 32A, 32B, 44A, 44B will typically be radiant burners with a gas-permeable burner plate formed from a metal fibre mesh (e.g. steel wire mesh) or ceramic mesh (ceramic gas burners).

[0170] A collection tray 22 is provided as part of the base unit 20 to collect the cooked food at the loading region 70 and to collect falling oil and cooking debris. An oil collection drum (not shown) may be provided beneath the collection tray 22 to receive oil from the tray.

[0171] As illustrated in FIGS. 2A-B, each hook element 110 is integrally formed as part of an outer link plate 52A of roller chain 52 and connected to neighbouring inner link plates 52B via link pins 52C engaging rollers 52D. In this specific example, the approximate dimensions are: a=76 mm; b=26 mm; c=25 mm; d=24 mm and e=44 mm.

[0172] As illustrated in FIGS. 4A-C and 6A-C, skewer supports 100 are configured to support a wide a variety of types of full-width skewers including flat blade skewers 150 and circular skewers 150, with the skewer supports 100 being configured to hold the skewers 150, 150 in a transverse orientation relative to the direction of travel such that the longitudinal length of the skewers 150, 150 extends from one lateral side of the path 60 to an opposed later side of the path. Although a single skewer 150, 150 is illustrated, the apparatus is equally suitable for foodstuff that is supported by pairs of skewer parts inserted into opposed lateral sides of the foodstuff with one the pairs of skewer parts being received in a first hook element 110 of the skewer support 100 and the other skewer part being received in a second hook element 110 of the skewer support.

[0173] As illustrated in FIGS. 2A-B, each hook element 110 comprises first and second jaw members 120A, 120B spaced to define an opening 130 configured to receive an end portion of a skewer and a shank portion 140 extending substantially perpendicular to the direction of travel.

[0174] First jaw member 120A defines a first curved inner surface 122A and a first protuberant lip 124A positioned at the opening 130. Second jaw 120B member defines a second curved inner surface 122B and a second protuberant lip 124B positioned at the opening 130.

[0175] Each hook element 110 is configured to maintain a predetermined perpendicular orientation relative to the conveyor chain system 50 such that the opening 130 is always facing perpendicular to the direction of travel of the conveyor system 50.

[0176] As shown in FIGS. 5B and 7B, first protuberant lip 124A is configured to retain a received skewer 150, 150 in the hook element 110 as the hook element 110 pivots from travelling in a first horizontal direction to travelling in a vertical upward direction (FIGS. 5A and 7A) and the skewer 150, 150 moves along the curved inner surface 122A of the hook element 110 towards the opening 130.

[0177] As shown in FIGS. 5C and 7C, second protuberant lip 124B is configured to retain a received skewer 150, 150 in the hook element 110 as the hook element 110 pivots from travelling in the first horizontal direction to travelling in a vertical downward direction (FIGS. 5C and 7C) and the skewer 150, 150 moves along the curved inner surface 122B of the hook element 110 towards the opening 130.

[0178] As shown in FIGS. 5D and 7D, each hook element 110 is configured to release a held skewer 150, 150 as the hook element 110 pivots from travelling in the vertical downward direction to travelling in a second horizontal direction opposed to the first horizontal direction (the unloading orientation), whereby the skewer 150, 150 is allowed to drop from the opening under gravity into the collection tray 22.

[0179] In operation, skewer supports 100 are presented in an upright loading orientation at the start of loading path section 60a (the loading path) with each hook element 110 facing upwards and are loaded with skewered food by dropped skewers 150, 150 bearing food to be cooked vertically into the openings 130 as the skewer supports 110 pass along the loading path section Skewer supports 100 are then conveyed by conveyer chain system 50 vertically upwards in a first heating orientation along the first heating path (path section 60b) before returning to the upright loading orientation and travelling along path section 60b.

[0180] Once skewer supports 100 reach the end of path section 60b, they are conveyed vertically downwards in a second heating orientation antiparallel to the first heating orientation along the second heating path (path section 60d).

[0181] As the skewer supports 100 reach path section 60e (the unloading region), the conveyor chain system 50 presents the hook elements 110 in a downward unloading orientation with the opening 130 of each hook element 110 facing downwards. In this rotational orientation the hook elements 110 are configured to automatically release the held skewers 150, 150 allowing the skewers 150, 150 to fall under gravity into collection tray 22.

[0182] In this way, cooking apparatus 10 is provided in which foods mounted on skewers (e.g. kebabs and other skewered foods) are cooked and unloaded into collection tray 22 with minimal input from a human operator.

[0183] FIGS. 8A-9B illustrate details of a further embodiment of a semi-automated cooking apparatus 10 for cooking skewered food based on cooking apparatus 10 (features in common are labelled accordingly).

[0184] Cooking apparatus 10 is distinguished from cooking apparatus 10 by a vertical loading path (path section 60a) in loading region 70 replacing horizontal path section 60a and by the user of an alternative design for skewer supports 100. Although the loading path section 60a is shown as vertical, in some embodiments an inclined near-vertical loading orientation may be preferred. In one embodiment, the loading orientation may be 15-20 off vertical.

[0185] As illustrated in FIG. 9A, each hook element 110 of each skewer support 100 comprises first and second jaw members 120A, 120B, but the hook element 110 includes only a single protuberant lip 124 provided on first jaw member 120A. As illustrated in FIGS. 10A and 10B, the first jaw member 120A with the protuberant lip 124 operates to retain a received skewer 150, 150 as the skewer support 100 travels along first path section 60a in the manner described in relation to cooking apparatus 10. However, as the skewer support 100 moves from the second path section 60b to the third path section 60c, the received skewer 150150 is retained against one or more vertically extending guide bar 160 mounted in a fixed position to base unit 20. Advantageously, the use of one or a pair of laterally spaced guide bars 160 may be used to reduce rotation of the received skewer 150, 150 as the skewer support 100 transitions between the second and third path sections. This may be particularly beneficial for certain kinds of food (e.g. chicken wings or other similarly flat foods) to avoid uneven cooking/reduce the risk of burning ends of food.

[0186] FIGS. 10A-F illustrate details of a yet further embodiment of a semi-automated cooking apparatus 10 for cooking skewered food based on cooking apparatus 10 illustrated in FIGS. 8A-C (features in common are labelled accordingly).

[0187] Cooking apparatus 10 is distinguished from cooking apparatus 10 by the replacement of first and second vertical heating stages 30, 40 with a single vertical heating stage 30.

[0188] As illustrated in FIGS. 10A-C, cooking apparatus 10 may be used to cook skewered foods in the same manner as described in relation to the previous embodiments.

[0189] FIGS. 10D-F further illustrate how cooking apparatus 10 may be used to mount baskets 170 for cooking delicate foods/foods that are difficult to skewer, such as fish, chops and chicken wings. As illustrated, each basket 170 comprises a closable wire mesh basket section 172 with one hinged side that is held closed by a small sliding latch ring (not shown), a skewer support mountable profile 174 comprising a pair of skewer-like profiles 174A, 174B extending from opposed ends of the basket 172 and a handle 176. The baskets 170 are mounted to skewer supports 100 in exactly the same manner as skewers 150 and are retained in position by hook elements 110/vertically extending guide bar 160. In this way, baskets 170 are retained so that the faces of the baskets 170, and hence the food contained in the basket, are presented for even cooking. Again, the baskets 170 fall into collection tray 22 at the end of the heating path.

[0190] Since no modification is required to the apparatus to accommodate the baskets 170, cooking apparatus 10 may be used for skewers 150, baskets 170 or a mixture of skewers 150 and baskets 170. However, as illustrated in FIG. 10D an optional guide bar extension 160 may be added on an opposed lateral side of the apparatus to the guide bar 160 to supplement guide bar 160 and to ensure correct orientation of baskets 170 as the baskets pass from the loading area towards the vertical heating stage 30.

[0191] FIGS. 12A-B illustrate details of a semi-automated cooking apparatus 210 in accordance with a further embodiment of the present invention for cooking flat foods 300 (e.g. burgers, haloumi slices, flatbreads).

[0192] Cooking apparatus 210 comprises a base unit 220 supporting a vertical heating stage 230 and an endless conveyor system 250 driven by a drive mechanism 254.

[0193] Conveyer system 250 comprises a primary air-permeable, heat transmitting wire mesh belt conveyor 270 operative to transport food along a predetermined path 260 extending from a loading region 262, through the heating stage 230, and onward to an unloading region 264, and a secondary air-permeable, heat transmitting wire mesh belt conveyor 280 operative to move along a predetermined second path 265 in an opposed rotary direction to primary conveyor 270. As illustrated, the primary and secondary conveyors 270, 280 meet at a start point of the vertical heating stage 230 and separate at an end point of the vertical heating stage.

[0194] As shown, drive mechanism 254 comprises a plurality of sets of drive shafts 254A each supporting end sprockets 254B operative to engage opposed lateral sides of the primary and secondary conveyors 270, 280 and drive synchronous circulation of the conveyors in opposed rotary directions.

[0195] Path 260 defined by primary conveyor 270 comprises in sequence: an upper loading path (inclined path section 260a); a heating path (downward vertical path section 260b); a first return path (horizontal path section 260c); and a second return path (vertical path section 260d extending in an opposed direction to path section 260b).

[0196] Path 265 defined by secondary conveyor 280 comprises in sequence: an upper path (horizontal path section 265a; a heating path (downward vertical path section 265b); a first return path (horizontal path section 265c); and a second return path (vertical path section 265d extending in an opposed direction to path section 265b).

[0197] Vertical heating stage 230 comprises a first pair of opposed gas burners 232A, 232B defining first and second heating surfaces 234A, 234B extending on opposed sides of the heating path (vertical downward path sections 260b/265b). Gas burners 232A, 232B, 44A, 44B will again typically be radiant burners with a gas-permeable burner plate formed from a metal fibre mesh (e.g. steel wire mesh) or ceramic mesh (ceramic gas burners).

[0198] A collection tray 222 is provided as part of the base unit 220 to collect the cooked food at the loading region 264 and to collect falling oil and cooking debris. An oil collection drum (not shown) may be provided beneath the collection tray 222 to receive oil from the tray.

[0199] As illustrated in FIG. 12A, primary conveyor 270 defines a first conveyor surface 272 operative to support an underside of food 300 placed on the conveyor and secondary conveyor 280 defines a second conveyor surface 282 operative to engage a top side of food 300 as the food passes through vertical heating stage 230, with the second conveyor surface 282 moving substantially in synchrony with the first conveyor surface. Each of the first and second conveyor surfaces 272, 282 further comprise an array of food gripping spikes 290 protruding outwards from the conveyor surfaces.

[0200] In use, flat food 300 is placed onto primary conveyor 270 at the inclined loading region 262 at the top of the apparatus. As the primary conveyor 270 advances the food is gently tilted into a vertical orientation as the primary conveyors passes over chain guide plates 251, at which point it is held upright between the opposing first and second conveyor surfaces 272, 282 as the primary conveyor 270 advances the food in a downward direction along the vertical heating path 260b and through vertical heating stage 230 with food gripping spikes 290 provided on both conveyors 270, 280 acting to prevent the food from slipping downwards relative to the conveyor surfaces. At the bottom of the vertical heating path the primary and secondary conveyors 270, 280 move apart on their respective sprockets, automatically releasing the food into the collection tray 222 (the unloading region 264) as in previous embodiments.

[0201] FIGS. 13A-H show alternative examples of food-holder support elements 110a-g for use in the cooking apparatus of FIGS. 1, 8A and 11A.

[0202] Support elements 110a and 110b are variations on double-lip hook element 110 as previously described.

[0203] Support elements 110c, 110d and 110e are variations on single-lip hook element 110 as previously described, with variations 110d and 110e including an inclined pair of jaw members with leading and trailing protuberant lips respectively.

[0204] Support elements 110f and 110g are variations for use with the cooking apparatus of FIGS. 8A and 11A and rely upon the use of one or a pair of laterally spaced guide bars 160, 160, 160 to retain a received skewer in the support element during vertical travel.

[0205] Support elements 110h is a further variation on double-lip hook element 110 as previously described with leading and trailing lips having different profiles and different angles of inclination.

[0206] FIG. 14 shows cooking apparatus 300 for cooking food comprising: a stainless steel frame 310 and a radiant burner 320 defining a vertical planar heating surface 330 bounded by the frame 310 and operative to provide an infrared heating action. Vertical heating surface 330 is notionally divided into an uppermost section 330A, a midway section 330B and a lowermost section 330C Radiant burner 320 comprises a gas-permeable burner plate 322 forming at least a part of the vertical heating surface 330 and a fan-driven gas supply inlet 324 operative to supply mixed air/fuel to the at least one burner plate 322. An ignitor and thermostat (not shown) are operative to ignite the mixed air/fuel supplied by the gas supply inlet 324 and maintain a constant heat output from the burner plate.

[0207] Gas-permeable burner plate 322 (which may typically take the form of a metal fibre mesh (e.g. steel wire mesh)) comprises a plurality of n active rectangular burner plate sections 326A each spaced vertically from a neighbouring active burner plate section by one of p rectangular stainless steel spacer sections 326B and connected to each neighbouring active burner plate section 326A by a pair of laterally opposed active burner plate side strips 326C (with burner plate sections 326A and side strips 326C typically being formed as a single piece). The n active rectangular burner plate sections 326A combine with the laterally opposed active burner plate side strips 326C to form the total active area of the vertical heating surface 330. The p rectangular spacer sections 326B combine to form the total inactive area of the vertical heating surface 330. In the illustrated embodiment, n=5 and p=4.

[0208] As shown, the plurality of n active burner plate sections 326A are each substantially equal in area whereas the p spacer sections have a vertical length that increase with distance from the lowermost section 330C of the vertical heating surface whereby the active burner area decreases with height along the vertical heating surface 330.

[0209] Since the heat output density in power per unit area (W/m.sup.2) of the n active burner plate sections 326A fed by the single gas supply inlet 324 is identical, the effect is a radiant burner that is divided into an upper heating zone 332 (extending from the midway section 330B to the uppermost section 330A of the vertical heating surface 330) and a lower heating zone 334 (extending from midway section 330B to the lowermost section 330C of the vertical heating surface 330), wherein the upper heating zone 332 is structurally configured to provide a lower heat output density in power per unit area than the lower heating zone 334 when both the upper heating zone and lower heating zone 332, 334 are activated to generate heat. Since a component of the heat generated by the lower heating zone 334 will act to supplement the heat of the upper heating zone 332, the burner plate 322 of the present invention provides a highly energy efficient way of providing even heating.

[0210] In one embodiment, the upper heating zone 332 is configured to provide a first heat output density H.sub.1 and the lower heating zone 334 is configured to provide a second heat output density H.sub.2, wherein H.sub.1 is approximately equal to 0.7*H.sub.2 (achieved by the upper heating zone 332 having approximately of the active area of the lower heating zone 334). However, other ratios of heat output may be advantageous (e.g. for different lengths of burner plate).

[0211] In one embodiment, the apparatus 300 is operative to heat food presented in a fixed vertical position relative to the heat source.

[0212] In one embodiment, the apparatus 300 is operative to heat food passing along a substantially vertical path extending alongside the heat source (e.g. vertical heating stage of the semi-automated cooking apparatus 10, 10, 10, 210 of the earlier embodiments).

[0213] The amount of heat generated by the apparatus 300 may be controlled by a dial that is manually set for the particular product being cooked. This in turn controls the fan which provides the gas volume combined with air in the correct proportions for efficient combustion with low nitrous oxide and carbon monoxide emission. A feedback system may be provided from the burner surface to maintain the same temperature that is set at the dial.

[0214] This combination of materials, profiles and control systems gives a more efficient infrared heating effect that is also more economical in its consumption of gas. Heat-up and cool-down times are rapid.

[0215] Electronic control of the burner fan and conveyor drive motor (where used in the vertical heating stage of the mechanical transport system of the semi-automated cooking apparatus 10, 10, 210 of the earlier embodiments) and the timed cooking of food by means of the mechanical transport system offers the following benefits: [0216] Personnel: reduced operator involvement means economy of operation; [0217] Efficiency: electronic control system means consistent speed of operation; [0218] Resources: economy of gas usage means lower cost to owner and environment; [0219] Environment: minimal smoke generated and less wasted heat.

[0220] FIGS. 15A and 15B illustrate a vertical rotisserie 400 for cooking a large item of food (in this example, a column of doner kebab meat 410).

[0221] As shown in FIG. 15A, vertical rotisserie 400 comprises: a rotatable spit 420 operative to support the item of food to be cooked and rotate about a rotary axis A; and a radiant burner 430 defining a heating surface 440 operative to provide an infrared heating action.

[0222] As illustrated, the heating surface 440 is a concave part-cylindrical heating surface (e.g. concave curved surface corresponding to a hollow cylindrical sector/hollow horizontal cylindrical segment) facing the rotatable spit 420 and centred around the rotary axis A. In this example, the concave heating surface 440 extends over an angle of substantially 100 and is formed by a concave part-cylindrical gas-permeable burner plate 450 (which may typically take the form of a metal fibre mesh (e.g. steel wire mesh)) of the radiant burner which is set within a similarly curved supporting stainless steel frame 452.

[0223] In the illustrated embodiment, the burner plate 450 comprises a main heating section 454 comprising circumferentially extending base portion 454A and a plurality of circumferentially spaced longitudinally extending sections 454B each of equal area and separated by equally sized longitudinally extending spacers 452A provided by the curved frame 452. In addition to the main heating section 454, first and second auxiliary heating sections 456A, 456B are provided at an upper end of the heating surface 440 (mirroring the geometry of the main heating section 454 but with a much shorter longitudinal length) and operative when activated to extend the effective longitudinal length of the concave curved heating surface. Each of the heating sections 454, 456A and 456B has a separate thermostat, ignitor and control circuitry and is operable independently of the main heating section. In use the gas-permeable burner plate 450 is configured to receive gas (or an air/fuel mixture) via a gas supply inlet (not shown) for ignition with gas being directed to the auxiliary heating sections if activated.

[0224] Advantageously, the width of the burner plate 450 is maintained at a constant distance from the food product giving more even cooking than existing art, with less heat being wasted. In the case of a doner-style meat column, the outer surface of the column is gradually removed for consumption causing the diameter of the meat column to gradually reduce over time. This may be compensated for by manually moving the burner plate 450 towards the meat (with the burner still wrapping part-way around the column).

[0225] The amount of heat generated by the burner is controlled by a dial that is manually set for the particular product being cooked. This in turn may control a fan which provides the air/gas mixture in the correct proportions for efficient combustion, with low nitrous oxide and carbon monoxide emissions. A feedback system may be provided from the burner surface to maintain the same temperature that is set at the dial.

[0226] Again, this combination of materials, profiles and control system gives a more efficient infrared heating effect that is also more economical in its consumption of gas. Heat-up and cool-down times are again rapid.

[0227] The burner 430 may be controlled automatically on a robotic machine operative to perform automated slicing of the cooked meat whilst it is on the spit, reducing the need for human intervention and control. Electronic control of the burner fan and drive motor, and the automatic cutting of the cooked meat, offer the following benefits: [0228] Personnel: reduced operator involvement means increased economy of operation; [0229] Efficiency: robotic control of cutting means increased speed of operation; [0230] Resources: economy of gas usage means less cot to owner and environment; [0231] Safety: reduced risk of injury means safer working conditions.

[0232] Although cooking apparatus 300 and 400 have been described in terms of pre-mixed air/fuel fan-driven radiant burners, the use of a fan-driven burner may readily be replaced by an atmospheric (fanless) burner, that is to say a burner in which gas alone is supplied to the burner via the inlet and air is separately drawn into the burner (e.g. by the Venturi effect).