WO2005063096A1

WO2005063096A1 - Insulated barbecue cooking device

Info

Publication number: WO2005063096A1
Application number: PCT/CA2003/002033
Authority: WO
Inventors: Gilles Boucher
Original assignee: Woodflame Inc.
Priority date: 2003-12-30
Filing date: 2003-12-30
Publication date: 2005-07-14
Also published as: AU2003292943A1

Abstract

An insulated barbecue cooking device (1) is disclosed. The insulated barbecue cooking device comprises a casing (2) having an open top (3); a grill (4) mountable on the open top; a heating means (5) housed within the casing and a removable cover (6) to close the casing. The casing has a double sidewall comprising an outer shielding wall (8); an inner wall (2) spaced apart from the outer shielding wall and a gap (10) between the outer and the inner walls. In a preferred embodiment, the outer wall comprises an air intake (22) in its bottom part and an air outlet (24) in its top part such that air is allowed to flow in the gap from the air intake to the air outlet. The flow of air circulating through the gap between the outer and the inner walls cools down these walls by convection and reduces the heat transmission to the outer wall, thus limiting the temperature that the outer wall will reach.

Description

INSULATED BARBECUE COOKING DEVICE

FIELD OF THE INVENTION

The present invention relates generally to the field of barbecue cooking devices. More particularly, it concerns an insulated barbecue cooking device.

BACKGROUND OF THE INVENTION

Portable cooking devices such as barbecue apparatuses comprising a burner using propane, charcoal or wood as the main source of fuel are already known from the prior art. Such barbecue apparatuses typically comprise a casing with an open top supporting a grill mountable over the open top and a burner located in the casing, under the grill. The burner comprises a combustion chamber where the fuel is allowed to burn in order to generate the heat necessary for cooking the aliments on the grill. In operation, the fuel may be of any nature such as propane, charcoal or wood as examples.

One of the main drawback remaining with the use of any barbecue cooking device known from prior art, independently of the type of fuel that is used, is due to the loss of energy/heat generated from the combustion chamber of the burner of these prior art cooking devices. These devices generate a significant amount of radiant, convection and conduction energy/heat which is emitted from the combustion chamber. This energy/heat loss is considerable and consequently, the energy/heat loss so generated contributes to compounding the problems and safety hazards associated with the extreme temperature that the external walls of these cooking devices typically reach, often over 600°F.

There is therefore a need for an improved barbecue cooking device. More specifically, there is a need for a barbecue cooking device that would provide for less radiant, convection or conduction energy/heat loss emitted to the external walls of the device and for lower temperature reached by these external walls of the device. SUMMARY OF THE INVENTION

An object of the present invention is to provide a cooking device that satisfies the above mentioned need.

Accordingly, the present invention provides an insulated barbecue cooking device, comprising a casing having an open top; a grill mountable on the open top; a heating means housed within the casing and a removable cover to close the casing. The barbecue cooking device is being characterized in that the casing has a double sidewall comprising an outer shielding wall; an inner wall spaced apart from the outer shielding wall and a gap between the outer and the inner walls.

Preferably, the insulated barbecue cooking device is characterized in that the outer wall comprises an air intake in a bottom part thereof and an air outlet in a top part thereof, thereby allowing air to flow in the gap from the air intake to the air outlet. The flow of air circulating through the gap between the outer and the inner walls cools down these walls by convection and reduces the heat transmission to the outer wall, thus limiting the temperature that the outer wall will reach.

Also preferably, the insulated barbecue cooking device according to the present invention is characterized in that each of the air intake and air outlet comprise at least one slit running respectively along a bottom edge and a top edge of the outer wall. In a preferred embodiment of the insulated barbecue cooking device, the casing consists of a shielding shell and a combustion container having similar geometric shapes, the combustion container nesting in the shielding shell and housing the combustion means. For that case, the outer shielding wall described above is an integral part of the shielding shell and the inner wall is an integral part of the combustion container. According to yet a preferred embodiment of the invention, the insulated barbecue cooking device is characterized in that the inner wall of the combustion container has a top edge with a flange for seating a peripheral edge of the grill. Also preferably, the outer shielding wall of the shell has a support surface located in a top end portion of the outer shielding wall for seating the flange of the inner wall of the combustion container. More preferably, the support surface consists of a plurality of individual flanges thereby limiting points of contact between the combustion container and the shielding shell.

According to another preferred aspect of the present invention, the insulated barbecue cooking device comprises a base support on which the shielding shell is mounted. Furthermore, it comprises a heat insulation barrier between the shielding shell and the base support, that may comprise silicon bushings.

The casing of the insulated barbecue cooking device preferably has the shape of a truncated rectangular base pyramid.

Also preferably, the insulated barbecue cooking device is characterized in that the insulation barrier also comprises a generally hollow receptacle for receiving a bottom portion of the shielding shell, thus creating an air gap between the shielding shell and the base support. More preferably, the hollow receptacle has a rectangular shape and it comprises a peripheral top edge that fits the shape of the casing. As can be appreciated and thanks to the double sidewall, an insulated barbecue cooking device according to the present invention provides for lower temperatures reached by the external walls of the casing.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects and advantages of the invention will become apparent upon reading the detailed description and upon referring to the drawings in which : Figure 1 is a perspective view of an insulated barbecue cooking device according to a preferred embodiment of the invention, with a cover;

Figure 2 is an exploded perspective view of the barbecue cooking device of figure 1 shown without the cover;

Figure 3 is a top plan view of the barbecue cooking device of figure 1 shown with the cover removed;

Figure 4 is a cross-sectional side view along line A-A of figure 3;

Figures 5 is a top plan view of the shielding shell of the barbecue cooking device of figure 1 , showing the air intakes and air outlets; Figure 6 is a perspective view of the shielding shell of figure 5.

While the invention will be described in conjunction with an example embodiment, it will be understood that it is not intended to limit the scope of the invention to such an embodiment. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included as defined by the appended claims.

DESCRIPTION OF A PREFERRED EMBODIMENT

In the following description, similar features in the drawings have been given similar reference numerals and in order to lighten the figures, some elements are not referred to in some figures if they were already identified in a preceding figure.

Referring to figures 1 to 4, the barbecue cooking device 1 comprises a casing 2 having an open top 3, a grill 4 mountable on the open top 3, heating means 5 housed within the casing 2, a removable cover 6 and a base support 7. As best shown in figure 4, the barbecue of the invention is characterized in that the casing 2 has a double sidewall comprising an outer shielding wall 8 and an inner wall 9 spaced apart from the outer shielding wall by a gap 10. This double sidewall prevents the transfer of heat between the interior of the casing 2 and the surroundings.

Turning now to figures 2 and 4, in the preferred embodiment illustrated, the double sidewall is actually the result of the combination of a shielding shell 11 with a combustion container 13. The combustion container 13 has a geometrical shape which is generally similar to the shape of the shielding shell 11 but in a slightly smaller size so that it can be nested into the shielding shell 11. Hence, in this particular embodiment, the outer shielding wall 8 of the casing 2 defines the side wall of the shielding shell 11 , and the inner wall 9 defines the side wall of the combustion container 13.

As best shown in figure 2, in the preferred form, the shielding shell 11 and the combustion container 13 preferably have an inverted squared pyramidal shape with four sidewalls (8,9) respectively. It is however worth mentioning that the present invention is not limited by that particular shape and that in another embodiment not illustrated, these two elements may have another shape, as for example, a conical shape or a rectangular or square shape.

The top edge of the sidewalls 9 of the combustion container 13 has a flange 15 for seating a peripheral edge 16 of the grill 4 whereas the sidewalls 8 of the shielding shell 11 have a top end portion provided with a support surface 18 for seating the the flange 15 of the combustion container 13.

More preferably, the support surface 18 consists of individual L-shaped flange supports 18, thus limiting the points of contact for heat conduction between the shielding shell 11 and the combustion container 13. The combustion container 13 has an open bottom delimited by a rim 20 seating on a base wall 19 of the shielding shell 11. The total surface of contact between the rim 20 and the base wall 19 is also minimal so has to reduce the heat conduction between the combustion container 13 and the shielding shell 11. The rim 20 has a square shape that fits exactly into a squared recess 21 created by the sidewalls 12 into the base wall 19.

The barbecue is provided with a heat dissipating means for dissipating the heat emitted from the combustion of fuel into the combustion container 13. Turning more particularly to figures 5 to 6, the heat dissipating means comprises at least one air intake 22 located in the bottom part of the sidewalls 8 of the shielding shell 11 , and at least one air outlet 24 located in the top part of the sidewalls 8, thereby allowing air to circulate in the gap 10 between the combustion container 13 and the shielding shell 11.

The air intake 22 and the air outlet 24 serve the purpose of creating a chimney effect whereby cool air enters into the casing through the air intakes 22, travels upwardly in the gap 10 and exits through the air outlets 24. The chimney effect so-created thereby reduces even more the temperature reached by the outer shielding wall 8 of the shielding shell 11.

The air intake 22 and the air outlet 24 preferably consist of slits running along the bottom edge and the top edge respectively of the sidewalls 8 of the shielding shell 11. More preferably, the air intake 22 consist of two slits covering almost the entire length of the bottom edge of each sidewall 8, and the air outlet 24 consist of one slit covering almost the entire length of the top edge of each sidewalls 8 of the shell 11. Each of these slits running along the top edge of the shell 11 are preferably provided with a baffle wall 30 that extends from a bottom edge of said slits. Such baffle wall 30 forces the air that comes from the air intake 22 to circulate upwardly before it exits from the air outlet 24.

Thanks to the double sidewall of the barbecue cooking device according to the invention combined with the heat dissipating means, the exterior of the outer shielding wall 8 reaches temperatures of about 300°F whereas the prior art barbecue device casings typically reach over 600°F. Referring now to figures 1, 2 and 4, the barbecue 1 further comprises a base support 7 on which the shielding shell 11 is mounted and a heat insulation barrier between these two components for limiting as much as possible the heat conduction from the shielding shell 11 to the base support 7. In the embodiment illustrated, such insulation is realized by the use of a base receptacle 14 and silicon bushings 25. More specifically, the barbecue 1 comprises a base receptacle 14 for mounting the shielding shell 11 on the base support 7. The base wall 19 of the shielding shell 11 sits on individual prongs 23 projecting from the receptacle 14, thereby leaving an air gap between the shielding shell and the base support 7, and thus limiting the heat conduction between these two elements. The use of these prongs 23 for supporting the shielding shell 11 also helps limiting the surface of contact between the base wall 19 and the base receptacle 14, and thus the heat conduction. The shielding shell 11 may be secured to the base receptacle by screwing it to the prongs 23. The base receptacle 14 is preferably fixed to the base support 7 by four screws.

The heat insulation barrier between the base support 7 and the shielding shell 11 is also obtained by using silicon bushings 25 between the components. More specifically, the shielding shell 11 and the base receptacle 14, as well as the receptacle 14 and the base support 7, are separated by silicon bushings 25 that are provided to further limit the direct heat conduction between these respective elements.

As a conventional barbecue, heating means 5 are provided inside the casing 2. The heating means 5 may be a conventional propane burner or, as illustrated, it is preferably a wood fed burner such as the one described in the Applicant's prior patent applications WO9908048 and WO9907267 and in US Patents Nos 4,924,847 and 4,747,781. More particularly, the combustion container 13 comprises a cup- shaped burner 17 located inside. Although not clearly illustrated, the burner 17 has a bottom wall 30 and a side wall section 27 delimiting a combustion chamber 28 located in an upper portion of the burner 17 and an air chamber 29 located beneath the combustion chamber 28. A diffuser plate is separating the combustion chamber 28 and the air chamber 29. The air chamber 29 has an air intake operatively connected to a blower to provide forced-air to the air chamber 29. The combustion chamber 28 is used to receive and burn a combustible material such as wood whereas the air chamber 29 provides the air necessary to burn the combustible material. The blower is part of a ventilation system that comprises the blower driven by an electric motor, and a power supply that provides power to the electric motor. The ventilation system comprises an opening for receiving air from outside. In use, pieces of wood are placed on the diffuser plate in the combustion chamber 28 and lighted. Then, the blower is turned on, to draw the air from outside into the ventilation system and forces the air into the air chamber 29 of the burner where air under pressure is forced through the diffuser plate to promote combustion of the wood.

Many grills and cooking surfaces are known and may be used with the barbecue apparatus of the present invention. In fact, any grill or equivalent cooking surface suitable for barbecuing foods may be used with the apparatus of the present invention. It is therefore understood herein and throughout the application, that the expression "grill" encompasses any and all grills as well as any and every other equivalent cooking surface suitable for use with barbecue.

Referring now to figures 1 and 2, the removable cover 6 of the insulated barbecue cooking device 1 presented herewith is pivotally attached to the shielding shell 11 with a shaft and sleeve attachment 26, allowing the cover 6 to be moved from a closed position to an open position.

The casing 2 including the shielding shell 11 and the combustion container 13 are preferably made of aluminium.

Although a preferred embodiment of the present invention has been described in detail herein and illustrated in the accompanying drawings, it is to be understood that the invention is not limited to this precise embodiment and that various changes and modifications may be effected therein without departing from the scope or spirit of the present invention. In this connection, it is worth mentioning that the shape of the casing is not limited to an inverted squared pyramidal shape. The casing could advantageously have a inverted conical shape, a conventional generally rectangular shape, a generally cylindrical shape, etc... as long as the sidewalls of the casing are double sidewalls as described above, that allows the casing to be insulated.

Claims

WHAT IS CLAIMED IS:

1. An insulated barbecue cooking device, comprising: -a casing having an open top; -a grill mountable on the open top; -heating means housed within the casing; and -a removable cover to close the casing; the barbecue cooking device being characterized in that the casing has a double sidewall comprising : -an outer shielding wall; -an inner wall spaced apart from the outer shielding wall; and -a gap between the outer and inner wall.

2. An insulated barbecue cooking device according to claim 1 , characterized in that: the outer wall comprises an air intake in a bottom part thereof and an air outlet in a top part thereof, thereby allowing air to flow in said gap from said air intake to air outlet.

3. An insulated barbecue cooking device according to claim 2, characterized in that: each of said air intake and air outlet comprises at least one slit running respectively along a bottom edge and a top edge of the outer wall.

4. An insulated barbecue cooking device according to any one of claim 1 to 3 characterized in that it the casing comprises : -a shielding shell; and -a combustion container with a geometric shape similar to the shielding shell, the combustion container nesting in the shielding shell and housing the combustion means; wherein the outer shielding wall is an integral part of the shielding shell and the inner waii is an integral part of the combustion container.

5. An insulated barbecue cooking device according to claim 4, characterized in that the inner wall of the combustion container has a top edge with a flange for seating a peripheral edge of the grill.

6. An insulated barbecue cooking device according to claim 5, characterized in that the outer shielding wall of the shell has a support surface located in a top end portion of the outer shielding wall for seating the flange of the combustion container.

7. An insulated barbecue cooking device according to claim 6, characterized in that the support surface consists of a plurality of individual flanges thereby limiting points of contact between the combustion container and the shielding shell.

8. An insulated barbecue cooking device according to claim 4, characterized in that it comprises a base support on which the shielding shell is mounted.

9. An insulated barbecue cooking device according to claim 8, characterized in that it comprises a heat insulation barrier between the shielding shell and the base support.

10. An insulated barbecue cooking device according to claim 9, characterized in that the insulation barrier comprises silicon bushings.

11. An insulation barbecue cooking device according to claim 10, characterized in that the insulation barrier further comprises a generally hollow receptacle for receiving a bottom portion of the shielding shell, thus creating an air gap between the shielding shell and the base support.

12. An insulated barbecue cooking device according to claim 1 characterized in that the casing has the shape of a truncated rectangular base pyramid.

13. An insulated barbecue cooking device according to claim 11 and 12 characterized in that the hollow receptacle has a rectangular shape; and the receptacle comprises a peripheral top edge that fits the shape of the casing.

14. An insulated barbecue cooking device according to claim 1 characterized in that the casing is made out of aluminium.