U.S. patent application number 09/797956 was filed with the patent office on 2001-08-23 for firebox for vertical hearth barbecue grill.
Invention is credited to Andress, Alphonso G., Hester, William D., Nielsen, Glen, O'Grady, Richard M..
Application Number | 20010015137 09/797956 |
Document ID | / |
Family ID | 22837978 |
Filed Date | 2001-08-23 |
United States Patent
Application |
20010015137 |
Kind Code |
A1 |
O'Grady, Richard M. ; et
al. |
August 23, 2001 |
Firebox for vertical hearth barbecue grill
Abstract
A removable firebox for use in a portable, collapsible barbecue
grill including retractable heating grate on top of the firebox and
a retractable mid-level cooking grill for providing
high-temperature cooking. A lower main grill is disposed in a base
cavity of the barbecue grill for providing moderate temperature
cooking. The firebox rests in the base cavity of the grill housing
and provides heat to a cooking area defined by the base cavity, an
upper lid of the housing and a pair of side walls extending upward
from the base cavity. The firebox and/or the upper lid includes
insulation and/or cooling baffles to protect users from heated
surfaces. Venting is provided from the sides and rear of the grill
housing. When collapsed, the grate and grills fold onto or are
retracted within the firebox, and the entire firebox assembly is
stowed in a sealed grill housing. The top and bottom portions of
the grill housing mate to form a sealed container-like structure
for convenient transportability or storage. The barbecue grill also
includes foldable legs which lock into extend position, when
deployed.
Inventors: |
O'Grady, Richard M.;
(Soughtington, CT) ; Nielsen, Glen; (Kent, CT)
; Hester, William D.; (Newinton, CT) ; Andress,
Alphonso G.; (Lima, PE) |
Correspondence
Address: |
LAWRENCE HARBIN
ONE MASSACHUSETTS AVENUE, N.W.
SUITE 330
WASHINGTON
DC
20001
US
|
Family ID: |
22837978 |
Appl. No.: |
09/797956 |
Filed: |
March 5, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09797956 |
Mar 5, 2001 |
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09339908 |
Jun 25, 1999 |
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6196116 |
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09339908 |
Jun 25, 1999 |
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09223789 |
Dec 31, 1998 |
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5947007 |
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Current U.S.
Class: |
99/340 ; 99/355;
99/421H; 99/447; 99/449; 99/450; 99/482 |
Current CPC
Class: |
A47J 37/0718 20130101;
A47J 37/0763 20130101 |
Class at
Publication: |
99/340 ; 99/355;
99/421.00H; 99/447; 99/449; 99/450; 99/482 |
International
Class: |
A23L 001/00; A47J
009/00 |
Claims
1. A removable firebox having a retractable heating grate and a
retractable cooking grill for providing heat to a cooking area
formed by a base cavity and extended side walls of a collapsible
barbecue grill, said barbecue grill also having a top cavity that
mates with said bottom cavity and said bottom cavity is constructed
to carry said firebox during stowing, said firebox comprising: a
generally vertically disposed container for holding a source of
fuel, said container having an open top and a lower confine
defining a bottom, opposed confines defining front and rear
segments, and opposed confines defining side segments, said front
segment being constructed to permit radiation of heat from said
source of fuel, said firebox including supports for pivotally
supporting a mid-level cooking grill between retracted and extended
positions and for supporting said mid-level cooking grill in a
generally horizontal position between the top and bottom of said
firebox, and said firebox further including supports for engaging
and supporting a heating grate, which supports a pot or kettle
directly over said source of fuel.
2. A barbecue grill comprising: a lid, a base cavity that mates
with said lid, a pair of sidewalls each being pivotably supported
on one of said lid and said bottom cavity, said sidewalls extending
upwardly from said base cavity when deployed thereby to further
define a cooking area between said side walls, a firebox comprising
a generally vertical enclosure that holds a source of heat, said
enclosure including an open top, a bottom, a front, a rear, and
opposed sides wherein said front is substantially planar and
permits radiation of heat from said source of heat, said base
cavity of barbecue grill including a support mechanism that
supports said firebox in a generally upright position near a rear
portion of said base cavity, and at least one cooking grill
connected with said firebox and adapted for movement between
extended and retracted positions.
3. The barbecue grill as recited in claim 2, wherein at least one
of said sidewalls and said firebox includes supports for holding
said cooking grill in an extended horizontal position across the
front of said firebox.
4. The barbecue grill as recited in claim 2, further including a
kettle rack arranged to support a pot directly above a source of
heat.
5. The barbecue grill as recited in claim 2, wherein at least one
of said side walls and said lid further includes a radiant
reflective surface to help confine heat within said cooking
area.
6. The barbecue grill as recited in claim 2, wherein said lid has a
double wall construction and includes insulation material between
said double walls.
7. The barbecue grill as recited in claim 2, wherein said firebox
has at least two cooking grill pivotably attached thereto that fold
over one another when retracted and that extend to different
vertical levels when retracted.
8. The barbecue grill as recited in claim 2, wherein said firebox
includes a kettle rack located at or near the top of said firebox
and adapted to retract within said firebox when retracted and to
extend over said firebox when extended.
9. The barbecue grill as recite in claim 2, wherein said firebox
and said cooking grills recede within said base cavity and lid upon
closure thereof.
10. The barbecue grill as recited in claim 2, wherein said firebox
is removable and engages pivoting supports in said base cavity when
inserted therein.
11. A removable firebox for use in a vertical hearth barbecue
grill, said firebox comprising: an enclosure that holds a source of
heat and including an open top, a bottom, a front, a rear, and
opposed sides wherein said front is substantially planar and
permits radiation of heat from said source of heat, and at least
one cooking grill pivotably connected with said firebox and adapted
for movement between extended and retracted positions.
12. The removable firebox as recited in claim 11, wherein said
firebox has at least two cooking grills pivotably attached thereto
that fold over one another when retracted and that extend at
different vertical levels when retracted.
13. The removable firebox as recited in claim 11, wherein said
firebox includes a kettle rack located at or near the top of said
firebox and adapted to retract within or against the outside
surface of said firebox when retracted and to extend over said
firebox when extended.
14. The removable firebox as recited in claim 11, wherein said
front comprises a grate grill.
15. The removable firebox as recited in claim 11, wherein said
housing comprises a heat resistant metal having a low coefficient
of expansion.
16. The removable firebox as recited in claim 11, wherein said
firebox includes vents in at least a lower portion thereof.
17. The removable firebox as recited in claim 11, wherein said
firebox includes pivot points for engaging pivoting receptacles in
a base cavity of a barbecue grill.
Description
BACKGROUND OF THE INVENTION
[0001] Outdoor cooking and barbecuing have become significant
activities, but traditional barbecue grills have remained unchanged
for quite a while. However, grills with vertical hearths have been
known in the art for some time. See, for example, U.S. Pat. Nos.
3,999,472 to Einto, 3,783,855 to Newinger, 3,611,912 to Choc,
3,550,525 to Rabello, 3,175,549 to Bergsten, as well as that art
mentioned in commonly-owned related U.S. Pat. No. 5,823,174 to
Andress. It is believed that vertical grills have not been
significantly utilized because prior models lacked convenience,
practicality and efficiency.
[0002] For example, the vertical grill disclosed by commonly-owned
U.S. Pat. No. 5,823,174 advantageously provided a vertical hearth
that extended below a main cooking grill whereby convective and
radiant heat from a heat source covered a relatively larger cooking
area. Coupled with sidewalls, this grill design increased the
amount of main grilling surface that was usable for grilling,
roasting or baking. Also, prior vertical grills neither provided
multiple cooking temperatures at plural cooking levels nor did they
provide kettle rack in combination with other grilling surfaces. In
addition, prior grills did not provide deployable or extendable
grate or grill members that facilitated portability and stowing.
Rotisserie rods were used in the past, but not in combination with
multiple multi-temperature grilling surfaces. Also lacking in prior
models was a removable firebox that accommodated these features.
The present invention, however, overcomes many of these as well as
other drawbacks and disadvantages.
[0003] It is therefore an objective of the present invention to
provide a rapidly deployable, portable and/or stationary barbecue
grill having a removable firebox that co-acts with a cooking
chamber to provide multi-temperature cooking.
[0004] It is another objective of the present invention to allow
such rapid deployment by providing collapsible barbecue grill
components, such as folding legs and fold-out side walls, and at
least one deployable cooking grid pivotally attached to a
firebox.
[0005] It is another objective of the present invention to provide
a firebox construction that supports at least one deployable and
retractable heating grate and/or cooking grill.
[0006] It is a further objective of the present invention to
provide a firebox-barbecue grill combination where the two, when
deployed, act together to create multiple heating surfaces at
multiple cooking temperatures to permit simultaneous cooking of
varied food items.
[0007] It is yet another objective of the present invention to
provide a firebox-barbecue grill housing combination wherein, upon
deployment, airflow is provided at the rear and/or lower portions
of the firebox thereby minimizing cooler air draft within or about
the cooking chamber.
[0008] It is yet a further objective of the present invention to
provide radiant-reflective surfaces in and/or about the firebox
receptacle thereby confining and directing heat to a main cooking
chamber of the barbecue grill.
[0009] It is yet a further objective of the present invention to
provide a barbecue grill that supports rotisserie rod, including
manual, mechanical or electro-mechanical drive means for the
rotisserie rod.
[0010] It is another objective of the present invention to provide
a firebox-barbecue grill housing construction that permits
efficient cooling of housing parts.
[0011] It is another objective of the present invention to provide
a barbecue grill with a large amount of grilling surface without
substantially increasing the overall weight of the barbecue
grill.
[0012] It is yet another objective of the present invention to
provide sufficient heat beneath a main cooking grill thereby
increasing the available cooking area of the main cooking
grill.
[0013] It is also an objective of the present invention to provide
a fixed, deployed barbecue grill having the above-specified
objectives, wherein various components thereof (legs, grates,
firebox, grills, sidewalls, etc.) may be secured or fastened in a
fixed position rather than being retracted.
[0014] It is another objective of the present invention to provide
a barbecue grill construction that is conveniently manufactured,
either using sheet metal or aluminum casted housing parts.
[0015] It is a further objection of the present invention to
provide a durable anti-warping firebox construction that resists
warping when heated.
[0016] It is yet a further objective of the present invention to
provide a firebox-grill housing combination that facilitates
cooling and heat shielding of grill housing parts during fuel
oxidation by providing insulation within and/or upon said grill
housing and/or providing cooling baffles upon said firebox and/or
grill housing.
SUMMARY OF THE INVENTION
[0017] In accordance with the invention, a firebox having at least
one deployable cooking grill provides heat to a cooking area
generally defined by a base cavity and extended side walls of the
barbecue grill is provided with a fixed or collapsible barbecue
grill. The firebox generally comprises a vertically disposed
enclosure having an open top, a bottom confine, opposed front and
rear confines, and opposed side confines for restricting a source
of fuel within boundaries. The front confine, which may comprise a
grate, wire mesh, or expanded metal, permits radiation of heat from
a fuel source, e.g., charcoal briquettes, wood chips, lava rocks.
The firebox also includes supports for supporting a mid-level
cooking grill in a substantially horizontal position between the
top and bottom of said firebox. In a refinement of the invention,
the firebox includes a pivoting mid-level cooking grill for
high-temperature cooking and a deployable kettle rack directly over
the burning fuel for heating a pot or kettle.
[0018] In another aspect of the invention, the firebox, with or
without a deployable grate or grill, forms the vertical hearth of a
barbecue grill and is storable in the base cavity when not in use.
When fully deployed, however, the firebox stands upright in spaced
relation to a rear housing wall or lid thereby facilitating cooling
of (or reducing heat transfer to) the outer grill housing.
[0019] These and other multiple objectives, advantages, and aspects
of the invention will become more readily apparent in view of the
description of illustrative embodiments and the accompanying
drawings. The invention, though, is pointed out with particularity
by the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1A is a perspective view of a removable firebox having
deployable grills according to one aspect of the present
invention.
[0021] FIG. 1B is also a perspective view of the embodiment of FIG.
1A without deployable grills.
[0022] FIG. 1C is a perspective view of another embodiment of a
removable firebox according to another aspect of the present
invention.
[0023] FIG. 1B., 1E., 1F, 1G, and 1H are conceptual illustrations
of a firebox according to various other aspects of the present
invention.
[0024] FIG. 2A is a perspective view of a fully deployed barbecue
grill including a vertical hearth in accordance with an aspect of
the present invention.
[0025] FIG. FIG. 2B depicts support flanges for a main grill within
the base cavity of the barbecue grill.
[0026] FIG. 2C shows a pivoting support structure for side walls
attached to the upper portion of a barbecue grill housing.
[0027] FIG. 2D depicts a support flange for sustaining a mid-level
grill in a horizontal position according to an aspect of the
present invention.
[0028] FIG. 3 depicts an exemplary supporting structure for a
rotisserie rod between side walls of a barbecue grill constructed
according to an aspect of the present invention.
[0029] FIG. 4A shows folding legs together with supporting
structure on the underside-of the lower portion of the barbecue
grill housing according to an aspect of the present invention.
[0030] FIG. 4B illustrates further details of the supporting
structure of FIG. 4A.
[0031] FIG. 4C depicts yet further details of the supporting
structure of FIG. 4B.
[0032] FIG. 5 shows folding legs of the barbecue grill in a
retracted position.
[0033] FIG. 6A shows a sealed barbecue housing of sheet metal
construction according to an aspect of the present convention.
[0034] FIG. 6B shows construction details of the upper housing for
a barbecue grill according to a sheet metal construction.
[0035] FIG. 6C illustrates attachment details of the structure of
FIG. 6B.
[0036] FIG. 6D and 6E illustrate rotational attachment between a
side wall and the upper housing of a barbecue grill according to
one aspect of the present invention.
[0037] FIG. 7A depicts a side view of the sheet metal version of a
barbecue grill including a removable firebox according to one
aspect of the present invention.
[0038] FIG. 7B is a front view of the barbecue grill of FIG.
7A.
[0039] FIGS. 8A and 8B are conceptual drawings of a collapsible
barbecue grill according to yet another aspect of the
invention.
[0040] FIG. 8C is a conceptual drawing of a removable firebox for
the barbecue grill of FIGS. 8A and 8B.
DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
[0041] As indicated above, objectives of the invention include
providing a firebox separate and apart from a barbecue grill
whereby to provide, among other things, convenient cleanup after
use, protection of barbecue grill housing from extreme heat,
self-contained storage of grill components, transportability,
collapsibility and rapid deployment of barbecue grill and grill
components. These objectives are provided, in part, by, for
example, a removable firebox 10 illustrated in FIGS. 1A and 1B. In
the illustrated embodiments, the firebox 10 provides a vertical
hearth for a barbecue grill and comprises a generally vertical
enclosure having an open top 11 and confines for holding fuel such
as charcoal, briquettes, wood chips and the like. A source of fuel
may also include a source of gas, a gas burner, and lava rocks
within the firebox. The firebox 10 has at least one planar surface
in front and is generally shown to have a rectangular
cross-sectional structure, but in practice, may take on a variety
of forms or shapes. As illustrated in FIGS. 1A and 1B, however, the
confines include side walls 12a and 12b, a rear wall 20, the bottom
confine 16, and a front confine comprising a grill 26. Although
illustrated in sheet metal construction, the firebox may also
include a steel or cast iron frame in order to provide strength to
prevent warping of the firebox when exposed to the extreme heat of
burning fuel. Stiffening ribs may be stamped into the sheet metal
in order to improve warping resistance to heat. Alternatively,
portions of or all surfaces of the firebox may be constructed of a
wire mesh, expanded metal, steel rods, or other materials.
[0042] The bottom portion of the firebox 10 includes a raised
flange 18 having a plurality of air vents 24, which assist in
maintaining an air draft that supplies the fuel during oxidation
thereof. Additional groups of vents 22a and 22b are provided in the
bottom portion of the sides 12a and 12b of the firebox. The firebox
10 also includes a pair of tabs 28a and 28b for providing pivot
points for a rod 31 of a mid-level 30, a pair of flanges 27a and
27b for supporting a grate grill as a front confine of the firebox,
and a pair of protruding flanges 34a and 34b, which provide pivot
points for rod 33 of kettle rack 32, i.e., a heating grate, for
supporting a kettle or pot directly above burning fuel. In a
deployed position, the mid-level grill 30 may be supported in a
horizontal position by anchors (not shown) located on side walls of
the grill housing, or alternatively, by a stop mechanism that
interacts with the mid-level grill 30 and any portion of the
firebox 10, such as side walls 12. The heating grate 32, when
folded over onto the top of the firebox 10, may rest directly on
top of the front grill 26 or on any other portion of the firebox in
order to sustain the heating grate 32 in a horizontal position.
[0043] Firebox 10 may also include cooling baffles on the sides
and/or rear confines thereof in order to reduce heat transfer to
the outer casing of the grill housing. Such baffles may take on a
variety of constructions, from single to multi-layer sheet metal.
Insulating material may also be employed to reduce heat transfer,
and air flow may also be induced in the rear portion of the grill
housing to facilitate cooling. Such flow may be provided by vents
within and/or spacing between parts of the barbecue housing, as
shown, for example, in FIG. 6A and 7A. When positioned in the base
cavity of the grill housing, firebox 10 is displaced from the rear
casing by at least a couple to a few centimeters in order to reduce
heat transfer to the grill housing.
[0044] FIG. 1C depicts one of many alternative embodiments of a
firebox. Here, firebox 10 provides a horizontal supporting
mechanism for both the mid-level grill 30 and the heating grate 32.
In addition, the firebox includes a mechanism for fully retracting
both the mid-level grill 30 and the heating grate 32. The front of
the firebox, at the lower portion, has a beveled cross-sectional
shape which provides obstruction clearance during rotational
movement of the firebox towards the base cavity of the barbecue
grill. In particular, studs 36a (not shown) and 36b co-act with
pivot supports in the base cavity of the barbecue grill so that the
firebox may be folded downwardly into the base cavity. When so
folded, cooking grill 30 retracts to a position parallel to the
front of the firebox and heating grate 32 folds upward and then
retracts downwardly into the firebox.
[0045] A deployment and retraction mechanism for the mid-level
grill 30 includes extension arms 41a and 41b of mid-level grill 30,
which co-act with flanges 38a 38b located on side walls 12a and 12b
of the firebox and with friction studs 40a and 40b, which lock the
mid-level grill 30 in a horizontal position upon rotation along
path 39. A rod 43 of the front confine of the firebox, extending
horizontally along the front of the firebox, provides an axis of
rotation for mid-level grill 30. Grill 30 includes extended members
47a and 47b for grasping and/or encircling the support rod 43.
Preferably, grill 30 comprises stainless-steel, porcelain coated
steel or other material for providing easy cleaning and a nonstick
surface.
[0046] Although termed a mid-level grill, its horizontal position
may lie at any vertical position between the top and bottom of the
firebox 10, depending upon the required heat application. A higher
placement provides greater heat. To meet certain other objectives
of the invention, the mid-level grill should be sufficiently high
enough from the bottom of the firebox to permit higher temperature
cooking than that provided by a main cooking grill, which extends
horizontally and perpendicular along a lower portion of the
firebox. Also, it is important that at least a portion of the
firebox extends below the main cooking grill in order to permit
sufficient radiation and convection of heat from the fuel source
into a heating area or chamber generally defined in a base cavity
of the barbecue grill. These components are subsequently described
in conjunction with the description of the combination of the
firebox and the barbecue grill.
[0047] Still referring to FIG. 1C, the heating grate 32 may also be
retracted when rotated upwardly generally along path 50, and then
displaced downwardly along path 51 when guided by slot pairs 42a
(not shown) and 42b disposed in side walls of the firebox. Heating
grate 32 includes protruding studs 49a (not shown) and 49b that
guide the rotational and displacement motion of the heating grate
32 during retraction and deployment. The width of heating grate 32
is slightly smaller than the inside width of the firebox 10 in
order to permit storage of the grate 32 inside firebox 10. Heating
grate 32 may be constructed of steel, iron, or may even comprise a
solid heating plate or other support structure for a pot or
kettle.
[0048] FIGS. 1D, 1E, 1F, 1G, and 1H show various
extension/retraction configurations of firebox grates and grills.
FIG. 1D, for example, depicts a firebox 10 having a retractable
heating grate 32, a retracted mid-level grill 30 and a retracted
main grill 52, each being pivotally attached and supported by the
firebox. FIG. 1E shows a firebox having a retractable heating grate
32 and a retracted mid-level grill 30. FIG. 1F depicts the firebox
of FIG. 1E when the heating grate 32 and the mid-level grill 30 are
in a deployed, extended position. FIG. 1G is a conceptual
perspective diagram of a firebox 10 having deployed heating grate
32, mid-level grill 30, and main grill 52. FIG. 1H shows the
firebox in relation to a barbecue grill having a lower portion 62
and upper portion 64. The firebox rests on pivot supports 66
located within the base cavity 60 of the barbecue grill. Support 66
helps to maintain the firebox 10 in a vertical position so that the
mid-level grill 30 and main grill 52 may rest in horizontal
positions. The barbecue grill of FIG. 1H is collapsible in the
sense that the top portion 64 may fold over and mate with the lower
portion 62 to provide a sealed container, which prevents ashes,
fuel, cooking residue and the like from spilling when stowed or
transported. The lower portion 62 of the barbecue grill provides a
cradle for the collapsed firebox 10 with retracted grill members
52, 30 and 32.
[0049] FIG. 2A is a perspective view of a barbecue grill utilizing
a firebox 10 as a vertical hearth. The collapsible barbecue grill
shown in the illustration includes a lower portion 62 having a base
cavity 60, an upper portion 64 that is adapted to pivot on hinges
to mate with lower portion 62, side walls 68a and 68b that may be
either hinged to the upper portion 64 or hinged to the lower
portion 62 and adapted to be folded outward or upward, as the case
may be, to define a heating area therebetween. Instead of hinging,
these components may be releasably fastened together. In a
stationary grill, these parts may be welded. Side walls 68a and 68b
also include punchouts 69a and 69b, which provide tabs 70a (not
shown) and 70b (FIG. 2B) for supporting mid-level grill 30 in a
horizontal position. Side walls 68a and 68b also include rotisserie
rod supports 76a and 76b for accepting a rotisserie rod and/or rod
turning mechanism. The rotisserie rod and turning mechanism may be
a standard off-the-shelf item, such as that available from
Char-Broil (W. C. Bradley Co.) or other barbecue parts supplier.
The base cavity 60 of the lower portion 62 of the barbecue grill
include flanges 61 and 63 (FIG. 2B) for supporting the main grill
52. The base portion 62 of the barbecue grill assembly also
includes foldable leg pairs 72a and 72b, each including respective
cross-member braces 74a and 74b.
[0050] FIG. 2C illustrates a possible hinging mechanism between
side wall 68b and an upper portion 64 of a barbecue grill. As
shown, the side wall 68b includes studs 78 and 79 located on
protruding flanges that mate with protruding flanges 80 and 81 of
the upper housing lid 64 of the barbecue grill in order to provide
a pivot support mechanism.
[0051] The barbecue grill may also include insulation material in
various parts thereof to protect users from extreme heat generated
by oxidizing fuel in the firebox 10. Insulation may comprise a
double-wall construction of lid 64 including insulating spacers,
e.g., ceramic, between inner and outer walls thereof. The
double-wall structure may include insulating material, such as
high-temperature fiberglass or other non-combustible material.
Thermal insulating material may also be place on the outside
surface of lid 64 to minimize or prevent touching hot metal parts
wherein the inside wall is even thermally insulated along the
periphery of the double wall seal. Sidewalls 68a and 68b may also
be coated with insulating material. Cooling baffles may be placed
on the rear portion of the firebox 10 or on the inside surface of
lid 64 to further reduce heat transfer to the outer housing.
[0052] FIG. 3 shows a relationship between a rotisserie rod 82 and
side walls 68a and 68b of the barbecue grill. Rotisserie rod 82
extends through a pair of supports 85 and 87, each of which is
positioned generally equidistant from a generally (but not
necessarily) planar surface of the firebox. Rotisserie rod 82 also
may be repositioned to a location closer to the firebox simply by
utilizing support pairs 86 and 88. Side walls 68a and 68b may have
additional sets or pairs of rotisserie rod supports. Also, a
driving mechanism 84 may be attached to either side wall in order
to rotate the rotisserie rod. The driving mechanism may be an
electrically operated motor or a coil spring motor providing
constant force or other rotation; or the rod may be manually turned
during cooking. A conventional constant force coil spring motor is
available from Ming Tai Industrial Co., Ltd. of Taiwan, and such a
driving mechanism would include gearing, ratcheting,
locking/release mechanism and spindles in a conventional way, as
known in the art. To assist in circumferentially positioning a
manually operated rotisserie rod, slot 87 may co-act with a
generally polygon cross-sectional rotisserie rod, i.e., square,
hexagonal, etc., to provide circumferential positioning when rod is
lifted, rotated and re-inserted into slot 87.
[0053] FIG. 4A shows further details of folding leg pairs 90a and
90b on the bottom portion 62 of the barbecue grill. Each leg pair
includes a flat cross member brace 92a and 92b, which is located on
complementary inner and outer sides of the folding legs so that the
leg pairs retract substantially into the same plane. FIG. 4B shows
a hinging and locking mechanism for each of the folded legs.
Flanges 94 and 96 support an axial pin (not shown) over which leg
98 rotates. At least one of the flange portions 96 includes a
locking mechanism 97 to lock the legs in an extended position when
the grill is deployed. These flanges 94 and 96 may be cast directly
in the body of the grill to save labor cost during manufacturing or
may comprise sheet metal flanges that are spot welded to the base
62 of the barbecue grill. Other attachment means may also be
employed. FIG. 4C depicts the geometric configuration of an inset
for supporting leg 98 in an extended position. In particular, a top
surface 99 of leg 98 mates with a flat portion 100 that is recessed
within the bottom portion 62 of the barbecue grill housing. A
curved portion 102 of the recess provides clearing for rotation of
leg 98 about an axis 104 (FIG. 4B) to a retracted position.
[0054] FIG. 5 shows a sheet metal construction for the retractable
leg assembly. An inner leg pair 114 and 116 are attached to the
base portion of the barbecue grill via flange assemblies 118 and
120, and are tied together by a flat flange 108. Flange assembly
118 and 120 provide pivoting support and a locking mechanism for
the leg pair when moved from a retracted to a deployed position. An
outer leg pair 110 and 112 are also supported by flange assembly
122 and 124, and are tied together by a flat flange member 106.
This construction provides retraction of all legs 110, 112, 114,
and 116 into substantially the same plane. Rather than having inner
and outer leg pairs, the legs in each pair may be staggered over
one another so that one leg lies in the inner position and the
other leg lies in the outer position relative to the periphery of
the base portion 62 of the barbecue grill.
[0055] FIG. 6A is a perspective view of the sheet metal constructed
barbecue grill showing a mating relationship between the upper and
lower housings 62 and 64. Also shown are stiffening ribs 130, 131,
132, 133 and 134, which may be die-stamped into the upper lid
housing 64 of the barbecue grill. A series of air vents may also be
provided in the top portion to assist in cooling. A handle 136 and
locking mechanisms 138 and 139 are also provided. FIG. 6B
illustrates possible construction details of the upper lid portion
64 of the barbecue grill wherein a die-stamped side member 140 may
be attached by welding or other fastening to a generally con-caved
structure 64. FIG. 6C depicts fastening by conventional spot
welding of sheet metal portions of the upper portion 64 and side
flange 140. FIGS. 6D and 6E depict an alternative hinging mechanism
between a side wall 68 and upper portion 64 of the barbecue
grill.
[0056] FIGS. 7A and 7B show a side view of the barbecue grill made
according to a sheet metal design. As indicated earlier, the major
component to the barbecue grill may also be cast using aluminum
metal. Sand or shell casting is preferred using high temperature
aluminum alloys selected from the group called AL 380, AL 356 and
AL 142. Other metals or alloys may also be used. According to
another illustrative design, a top portion 64 is hinged to bottom
portion 62 by piano hinge 142. Parts of the grill housing may be
cast iron to provide heat durability.
[0057] Firebox 10 is supported by a pivot support plate 144 that is
fastened to a wall within base portion 62. Pivot support plate 144
is positioned to allow the firebox to rotate downwardly into the
base portion 62 to a stowed position, and to permit a portion of
the firebox 10 to extend below a main grill 52 when deployed
vertically. Instead of pivoting, the firebox may rest in a
receptacle or cradle comprising stops, tabs, flanges, etc. fixedly
attached within the cavity 60 of base 62. Importantly, the firebox
10 should extend below the main grill 52 so as to provide radiant
and convective heat to a larger area underneath grill 52.
[0058] Also shown is a buffering space 148 between the rear of the
firebox 10 and grill housing 64. This helps to reduce heat transfer
to the outer lid housing 64 during fuel oxidation. Housing 64 may
also have a double wall construction with internal insulation,
similar to an oven door, in order to shield the outer wall of the
housing 64 from heat. Side walls 68 may have a similar
construction. Furthermore, gaps 150 and 152 provide airflow
openings to sustain an air draft for oxidizing fuel in the firebox.
Such venting may also exist along the area of piano hinge 142 or
within portions of the upper and lower housings 62 and 64 spanning
firebox 10. Airflow through and/or about the rear and side portions
of the barbecue grill may be received by corresponding air vents in
the side and rear of the firebox 10, which reduces the amount of
any downward draft through the main grill 52, to oxidize fuel. Such
downdrafts tends to cool the heating chamber thereby reducing
cooking temperatures.
[0059] Side walls 68 include a flange assembly 146 having
protruding ends that mate with tab 148 (FIG. 1C) in order to hold
the firebox 10 in a vertical position commonly-owned related U.S.
Pat. No. 5,823,174 and U.S. application Ser. No. 09/190118,
incorporated herein, in which case a burner would be added, or the
invention may be used simply with charcoal, briquettes, wood chips
and the like.
[0060] The appended claims are to be given their broadest
reasonable interpretation within the limits of the prior art, and
no part of the foregoing description should be viewed as limiting
their construction. Unless expressly restricted by definition in
the written description of the invention, words used in the
appended claims are to be given their ordinary meaning.
[0061] We claim: when deployed. The grill housing of the sheet
metal embodiment of the invention is preferably power coated with
baked enamel. Sheet metal of about 18 gage is believed to be
satisfactory for housing construction, and where strength is
required, plates may be added or stiffening ribs may be stamped
therein. To reduce overall weight without reducing overall
dimensions of the grill, a thinner metal, i.e., 20 gage sheet
metal, and stiffening ribs may be used. A basic unit of the
barbecue grill measures approximately 18" by 24" by 8" but these
dimensions may vary. The aluminum shell or sand casted models will
have a wall thickness between approximately one-eight to
one-quarter inches. Larger units of both the sheet metal and casted
versions may include wheels attached to at least one pair of
folding legs so that, when collapsed, the unit may be transported
in a manner similar to a luggage cart. A smaller tabletop unit need
not have legs, but may include insulating table mounts on the
underside to shield heat. A drip pan (not shown), such as a
disposable aluminum pan, may be used in the base cavity to catch
grease and/or ash drippings.
[0062] FIGS. 8A, 8B and 8C are conceptual renditions of a barbecue
grill assembly for receiving and supporting a removable firebox.
FIG. 8A illustrates an arrangement of tabs, stops and flanges
within the base cavity 60 of the lower portion 62 of the barbecue
grill. FIG. 8B shows an enclosure design provided by the barbecue
grill. FIG. 8C is a conceptual rendition of a removable firebox
having deployed grate and cooking grill members.
[0063] The above illustrative embodiments of the invention defined
by the appended claim, and the written description and drawings are
not intended to limit the subject matter of the invention.
According to the teachings hereof, materials may be substituted,
shapes may be altered, and the construction of grill parts may be
changed without departing from the general nature and character of
the invention. For example, instead of hinging and/or pivoting, any
of the components mentioned above may be releasably or permanently
fastened together. Rather than have a rectangular cross-sectional
shape, the firebox may take on a variety of other forms, including
circular, elliptical, oval, etc.. The invention may be used with
lava rocks and include a gas source, as described in
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