AU598400B2

AU598400B2 - Barbecue and radiant ceramic plate therefor

Info

Publication number: AU598400B2
Application number: AU23964/88A
Authority: AU
Inventors: Roger Philip Stanbridge
Original assignee: Foseco International Ltd
Current assignee: Foseco International Ltd
Priority date: 1987-10-20
Filing date: 1988-10-17
Publication date: 1990-06-21
Anticipated expiration: 2008-10-17
Also published as: ZA887650B; AU2396488A; GB8724492D0

Description

2- 598 COMMONWEALTH OF AUSTRALIA PATENTS ACT 1952 COMPLETE SPECIFICATION

(ORIGINAL)

FOR OFFICE USE Form Short Title: Int. Cl: Application Number: Lodged: This document contains the amendments made under Section 49 and is correct for printing.

Complete Specification-Lodged: Accepted: Lapsed: Published: Priority: Related Art: 00o0

OD

'I 0 i, TO BE COMPLETED BY APPLICANT Name of Applicant: Address of Applicant: Actual Inventor: Address for Service: FOSECO INTERNATIONAL LIMITED 285 Long Acre, Nechells, BIRMINGHAM B7

ENGLAND

Roger Philip Stanbridge GRIFFITH HACK CO 71 YORK STREET SYDNEY NSW 2000 1 t I 04 4 0 t Complete Specification for the invention entitled: "BARBECUE AND RADIANT CERAMIC PLATE THEREFOR" The following statement is a full description of this invention, including the best method of performing it known to me/us:- 6306A/as IA- FS 1384 BARBECUE AND RADIANT CERAMIC PLATE THEREFOR This invention relates to barbecues and radiant ceramic plates for use in barbecues.

Gas or electrically heated barbecues are usually designed such that food to be cooked is supported on a grid or spit above a source of radiant heat. A layer of ceramic or refractory material or a structure of ceramic or refractory material is interposed between the source of heat and the food. The interposed layer or structure is intended to promote uniform distribution of heat to the food and to reduce undesirable overheating effects caused by flare-up which arises when liquid fat from the food falls onto the source.

All the materials used for forming the interposed layer and all the structures used hitherto suffer from one or more important disadvantages. Lava rock lumps which are commonly used are of irregular shape and this precludes obtaining fully uniform heating of the food and also results in the retention of grease or fat which can flare excessively by burning on the surface of the lumps. Manufactured ceramic briquettes are of high thermal capacity and are therefore slow to heat up. Furthermore it is difficult to design and arrange ceramic briquettes so that they permit run off of grease or fat while at the same time maintaining the spacing

PA-

2 FS 1384 between the briquettes small enough to prevent penetration of flare-up from below. With known structures such as plates having a ceramic honeycomb structure it is necessary to compromise between an aperture size which is large enough to prevent upper surface blockage by pyrolysed grease or fat residue and small enough to restrict penetration by flare-up, and a plate with a given aperture size will not produce the desired results for all foods and all cooking conditions.

It has now been found that the disadvantages associated with the use of a layer of ceramic or refractory material or with known ceramic plates can be overcome using a radiant ceramic plate having holes whose cross-sectional area at the top of the plate is larger than the cross-sectional area at the bottom of the plate.

According to the invention there is provided a barbecue comprising a heat source, support means for food to be heated located above the heat source and between the heat source and the support means, a radiant ceramic plate having an upper face and a lower face and a plurality of holes whose cross-sectional area at the upper face is larger than the cross-sectional area at the lowe face.

According to a further feature of the invention there is provided a radiant ceramic plate for a barbecue, the plate having an upper face and a lower face and a plurality of holes

U

i l i 3 FS 1384 whose cross-sectional area at the upper face is larger than the cross-sectional area at the lower ii face.

The holes in the radiant ceramic plate may be any of a variety of shapes, for example square, rectangular, triangular, diamond shaped or round. For ease of manufacture square holes i or round holes are preferred.

The holes preferably taper uniformly 1 0 from the upper face to the lower face and the I number of holes and their cross-sectional area i are preferably such that the upper face of the Splate has a minimum of 50% open area and the I lower face of the plate has a maximum of 25% open area.

When the holes in the plate are square 'i aor round they preferably have a size of 0.6 cm square or 0.6 cm diameter to 2.5 cm square or il2.5 cm diameter at the upper face and a size of i'.l 2.5 cm d aee t t eu prf c n ie o 0.3 cm square or 0.3 cm diameter to 1.5 cm square Sor 1.5 cm diameter at the lower face. The plate ii preferably has a thickness of 0.6 cm to 2.5 cm.

ii! The material from which the radiant ceramic plate is made and its method of manufacture may be chosen from a variety of ceramic materials and methods with selection based on the ability of the material to withstand the temperature and thermal shock conditions associated with its intended use in a barbecue and to provide satisfactory performance in terms of I

I

4 FS 1384 rapid heating up and radiant heating of food to be cooked. Examplesof suitable materials include refractory cements and bonded particulate K refractory materials such as bonded refractory oxides or silicates.

The radiant ceramic plate may be made as one piece or it may be made up of a number of modules. A plate made up of a number of modules has 'the advantage that if one of the modules is broken it may simply be replaced without replacing all the others. When the plate is made in one piece it can be strengthened by making it in such a way that it has a number of sections having holes and separating those sections by narrow sections or strips having no holes.

Apart from the heat source, the support means for food to be heated and the radiant ceramic plate the barbecue of the invention will also usually have a casing and optionally a hinged or removable lid.

The heat source may be for example a gas fired burner or an electric element and the support means for food may be for example a metal grid or a spit.

When the radiant ceramic plate is a single component it may be supported at its periphery by support means fixed to the casing of the barbecue. When the plate is made up of a number of modules they may be supported on a frame which is in turn supported at its periphery by support means fixed to the casing.

FS 1384 Provision of a high proportion of flat ceramic surface towards the heat source permits uniform and rapid heat up of the plate and restricts passage of flare-up flame through the plate and provision of a high proportion of open surface towards the food permits grease or liquid fat to enter the plate from the heated food without collecting on the upper surface of the plate.

Depending on the flammability of the grease or fat and the temperature of the plate the grease or fat will either burn with minimum flare-up on the tapered walls of the holes or will pass through the plate and will burn in contact with the heat source. Penetration of the flare-up flame through the plate is substantially eliminated.

The invention is illustrated with reference to the accompanying drawings in which Figure 1 is a perspective view of a radiant ceramic plate according to the invention and made up of eight separate sections, Figure 2 is a cross-sectional view through part of one of the sections making up the plate of Figure 1 and Figure 3 is a perspective view, part cut away, of a barbecue according to the invention.

Referring to Figures 1 and 2, a radiant ceramic plate 1 for use in a barbecue was made up of eight sections 2 of equal size. The overall 6 FS 1384 i size of the plate was 52.7 cm long, 26.7 cm wide Sand 1.27 cm thick. The plate had a total of 512 i square cross-section uniformly tapered holes 3, only some of which are shown in Figure 1, extending from the upper face 4 of the plate 1 to the lower face 5. Each of the holes 3 had an upper i dimcnsion 6 of 1.27 cm square and a lower dimension 7 of 0.64 cm square. The open area of the upper face 4 was approximately 59% of the total i 10 surface area of the upper face 4 and the open area of the lower face 5 was approximately S of the total surface area of the lower face The sections 2 making up the plate 1 i were made in DELTEK ZS a proprietary thermal if shock resistant ceramic material manufactured by i Foseco Inc.

The plate was tested by interposing it between the heat source and the cooking surface 1 of a 24000 BTU per hour Char Broil propane fueled portable barbecue manufactured by Bradley Enterprises. It was found with various foods that the presence of the radiant ceramic plate ii instead of the lava rock lumps usually contained in the barbecue permitted uniform controlled cooking, In the cooking of meat products the 1 plate substantially eliminated the problem of excessive flare-up.

Referring to Figure 3 a barbecue for cooking food comprises an outer casing 11, a gas fired burner 12 and a metal grid 13 to support the food and interposed between the burner 12 and 7 FS 1384 the grid 13 a radiant ceramic plate 14 supported at its periphery on ledges 15. The plate 14 has eight sections having a plurality of square shaped holes 16 whose cross-sectional area at the upper face of the plate 14 is greater than the i i cross-sectional area at the lower face of the plate 14. The sections of the plate 14 having the square shaped holes 16 are separated by narrow sections or strips having no holes.

:i ii

Claims

2. A barbecLue according to Claim 1 wherein the shape of the holes in the radiant ceramic plate is square, rectangular, triangular, diamond shaped or round.
3. A barbecue according to Claim 1 or Claim 2 wherein the holes taper uniformly from Sthe upper face of the plate to the lower face. S4. A barbecue according to any of Claims S1 to 3 wherein the number of holes and their cross-sectional area are such that the upper i face of the plate has a minimum of 50% open area and the lower face of the plate has a maximum of open area. A barbecue according to any of Claims 2 to 4 wherein the holes are square shaped and have a size of 0.6 cm square to 2.5 cm square at the upper face of the plate and a size of 0.3 cm square to 1.5 cm square at the lower face. i9 FS 1384
6. A barbecue according to any of Claims 2 to 4 wherein the holes are round and have a d size of 0.6 cm diameter to 2.5 cm diameter at the i upper face of the plate and a size of 0.3 cm diameter to 1.5 cm diameter at the lower face. i 7. A barbecue according to any of Claims I 1 to 6 wherein the radiant ceramic plate has a i thickness of 0.6 cm to 2.5 cm.
8. A barbecue according to any of Claims 1 to 7 wherein the radiant ceramic plate is made in one piece.
9. A barbecue according to Claim 8 wherein i the radiant ceramic plate has sections having holes and those sections are separated by sections having no holes. A barbecue according to any of Claims 1 to 7 wherein the radiant ceramic plate is made Sup of a number of modules. I 11. A barbecue according to any of Claims 1 to 10 and having a casing. S12. A barbecue according to Claim 11 wherein the radiant ceramic plate is made in one piece and is supported at its periphery by support means fixed to the casing.
13. A barbecue according to Claim 11 wherein the radiant ceramic plate is made up of a number of modules and is supported on a frame which is i j 10 FS 1384 supported at its periphery by support means fixed to the casing.
14. A barbecue substantially as herein described with reference to Figure 3 of the accompanying drawings. A radiant -ceramic plate for a barbecue i the plate having an upper face and a lower face and a plurality of holes whose cross-sectional area at the upper face is larger than the cross- -sectional area at the lower face.
16. A radiant ceramic plate according to i Claim 15 wherein the shape of the holes is square, f rectangular, triangular, diamond shaped or round.
17. A radiant ceramic plate according to SClaim 15 or Claim 16 wherein the holes taper i uniformly from the upper face of the plate to the lower face. :I i 18. A radiant ceramic plate according to any of Claims 15 to 17 wherein the number of holes and their cross-sectional area are such that the I upper face of the plate has a minimum of 50% open area and the lower face of the plate has a maximum of 25% open area.
19. A radiant ceramic plate according to any of Claims 16 to 18 wherein the holes are square shaped and have a size of 0.6 cm square to 2.5 cm square at the upper face of the plate and a size of 0.3 cm square to 1.5 cm square at the lower face. S- 11 FS 1384
20. A radiant ceramic plate according to any of Claims 16 to 18 wherein the holes are round and I have a size of 0.6 cm diameter to 2.5 cm diameter at the upper face of the plate and a size of 0.3 cm diameter to 1.5 cm diameter at the lower face.
21. A radiant ceramic plate according to any of Claims 15 to 20 having a thickness of 0.6 cm to cm.
22. A radiant ceramic plate according to any of Claims 15 to 21 made in one piece.
23. A radiant ceramic plate according to SClaim 22 wherein the one piece plate has sections having holes and those sections are separated by sections having no holes.
24. A radiant ceramic plate according to any of Claims 15 to 21 made up of a number of modules. i' 25. A radiant ceramic plate substantially as I herein described with reference to the accompanying drawings. i Dated this 17th day of October, 1988 FOSECO INTERNATIONAL LIMITED By their Patent Attorney GRIFFITHI HACK CO. p 1 i; i .1 L i.