Note: Descriptions are shown in the official language in which they were submitted.
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FOOD COOKING OVEN
This application is a division of Canadian Patent
File No. 2,484,063 filed May 7, 2003.
The present invention relates to ovens for cooking
food.
More particularly, the invention relates to an oven
for cooking food that comprises:
- an enclosure for receiving the food to be heated
and for containing a cooking atmosphere, the enclosure
having two horizontal walls forming respectively a bottom
and a ceiling, interconnected by at least two vertical
side walls, said enclosure being closed by at least one
door that is also vertical;
- a heater device placed inside the enclosure; and
- a fan also placed inside the enclosure comprising
at least one blade rotating about a central space,
following a circular path centered on an axis of rotation
in order to stir the cooking atmosphere heated by the
heater device.
Ovens of this type are already known in which, for
example, the food for cooking is placed on trays disposed
at a plurality of levels. In such ovens, the food must
all cook at the same speed and with the same degree of
cooking at all of the levels. It is therefore
particularly important to ensure that heat is distributed
uniformly within such ovens.
Accordingly, the present invention seeks to improve
the uniformity with which heat is distributed within the
enclosure of an oven of this type.
To this end, according to the invention, an oven is
provided which, in addition to the characteristics
mentioned above, is characterized by the fact that the
heater device is placed facing the central space situated
inside the circular path.
By means of these dispositions, the heat produced by
the heater device is sucked in by the fan and then
distributed around it in uniform manner. This
contributes to considerably improving the distribution of
heat throughout the volume of the enclosure.
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The invention in a broad aspect provides an oven for
cooking food, the oven comprising walls forming an
enclosure having an opening for receiving the food to be
heated and for containing a cooking atmosphere, the
opening being closed by at least one door. A heater
device is placed inside the enclosure and a fan is also
placed inside the enclosure, the fan comprising at least
one blade rotatable about a central space, following a
circular path centered on an axis of rotation in order to
stir the cooking atmosphere heated by the heater device.
The heater device is placed facing the central space
which is situated inside the circular path and wherein
the heater device is a gas burner. The oven further
comprises a gas feed duct for feeding gas to the gas
burner, an igniter for lighting the gas, and at least one
electrical wire for electrically powering the igniter,
wherein the wire runs within the gas feed duct.
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In preferred embodiments of the invention, recourse
may optionally be had to one or more of the following
dispositions:
- the axis of rotation is horizontal; thus, for
example, the fan is mounted to rotate on one of the
vertical walls of the enclosure;
- the heater device is an electric element or a
burner for burning gas;
- in this last case, the burner comprises a bowl and
a plate, the bowl being connected to a duct for feeding
gas for burning, and being closed by the plate covering
its face facing towards the wall of the enclosure on
which the fan is mounted, the plate being provided with
orifices for passing the gas for burning; the burner is
thus oriented towards the wall of the enclosure on which
the fan is mounted; thus, if the burner and the fan are
protected merely by a simple grid, the heat generated by
the burner is not emitted directly towards the food to be
heated and/or cooked;
- the orifices in the plate of the burner are
adapted so that the flames generated by burning the gas
for burning are distributed over 360 about the axis of
rotation;
- wires for electrically powering a device for
lighting the gas of the burner pass within the feed duct;
advantage is thus taken of the relatively low temperature
that exists inside the feed duct, given that it is swept
by the gas for burning, thereby protecting the electrical
power supply wires contained therein;
- the plate is provided with an igniter electrode
and with a flame control device, e.g. operating by
ionization; and
- the oven includes a protective grid provided with
a frame defining an opening of area greater than or
substantially equal to the area of the fan when
considered perpendicularly to the axis of rotation.
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Other aspects, objects/, and advantages of the
invention will appear oR- reading the following
description of an embodiment thereof.
The invention will also be better understood with
the help of the drawings, in which:
- Figure 1 is a diagrammatic perspective view of an
embodiment of an oven of the invention;
- Figure 2 is a diagrammatic section view of the
oven shown in Figure 1, on the vertical plane
perpendicular to its back wall, intersecting the back
wall and the burner substantially in the middle;
- Figure 3 is a diagrammatic section in a plane
analogous to that of Figure 2, showing the burner of the
oven shown in Figures 1 and 2;
- Figure 4 is a diagrammatic plan view of the plate
of the burner shown in Figures 2 and 3;
- Figure 5 is a diagrammatic front view of a variant
of the protective grid which, in certain variants of the
oven of the invention, serves to protect its burner and
its fan; and
- Figure 6 is a diagrammatic section view through
the protective grid shown in Figure 5.
In the various figures, the same references are used
to designate elements that are identical or similar.
An embodiment of the oven of the invention is
described below with reference to Figures 1 to 4.
As shown in Figure 1, the oven 1 of the invention
comprises an enclosure 2 contained in a casing 3. The
casing 3 has means 4 for regulating temperature inside
the enclosure 2, and a door 5 for inserting food into the
enclosure 2.
The enclosure 2 is substantially in the form of a
rectangular parallelepiped having a front face 6 that is
open or closed by the door 5, a back wall 7 that is
opposite the front wall 6, two vertical side walls 8
between the front face 6 and the back wall 7, and a
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bottom wall 9 and a ceiling 10 forming two horizontal
walls.
As shown in Figure 2, the oven 1 of the invention
also comprises a heater device 11, a fan 12, a protective
grid 13, and slideways 14. The fan 12 is mounted on the
back wall 7.
The heater device 11 is placed inside the enclosure
2 facing the fan 12. Advantageously it is a burner for
burning gas. It is fed with gas for burning by a duct
15. The burner is ignited by an electrode 16 that is
powered electrically by a wire 17 penetrating into the
burner via the duct 15. The burner is described in
greater detail below with reference to Figures 3 and 4.
The burner advantageously includes a flame control
device 16a, e.g. using ionization, that is connected to a
control unit (not shown) by a wire 17a.
The gas for burning is advantageously a mixture of
air and gas and it is delivered to the burner at small
positive pressure.
The fan 12 is constituted by a disk 18 centered on
an axis of rotation 19. At the periphery of the disk 18,
the fan 12 has a plurality of blades 20 that are
regularly distributed angularly around the axis of
rotation 19. The blades 20 are constituted, for example,
by plane rectangular plates extending in planes that are
substantially perpendicular to the disk 18 and that
include the axis of rotation 19. While they are being
rotated, they follow a circular path centered on the axis
of rotation 19 and defining a central space 21. The fan
12 is rotated about the axis of rotation 19 by a motor
22, e.g. an electric motor. It serves to distribute the
heat energy within the enclosure 2.
The protective grid 13 extends in a vertical plane
facing the disk 18, in front of the burner 11 and the fan
12, relative to the space 23 that is to receive the food
to be heated and that is situated between the burner 11
and the door 5.
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Ten pairs of slideways 14 are disposed substantially
horizontally on the side walls 8. Each side wall 8 has
one of the slideways 14 of each pair. These slideways 14
enable trays to be supported, which in turn serve to
5 carry the food that is to be heated and/or cooked.
The burner 11 is placed facing the central space 21.
Advantageously, a portion of the burner 11 penetrates
into the central space 21. The enclosure 2 includes an
exhaust orifice 31 for exhausting gas contained inside
the enclosure 2.
As shown in Figure 3, the burner 11 comprises a bowl
24 and a plate 25. Advantageously the bowl 24 and the
plate 25 are made of brass.
The bowl 24 is connected to the feed duct 15 and it
is closed by the plate 25 on the side of the burner 11
that faces towards the back wall 7 of the enclosure 2.
As shown in Figure 4, the plate 25 is in the form of
a ring with a central opening 26 which is extended,
perpendicularly to the plate 25 to the bottom of the bowl
24 by a tube 27. The plate 25 is substantially
15 millimeters (mm) in thickness. The zone of the ring
that is situated between the central opening 26 and its
periphery is pierced by orifices 28 that are regularly
spaced apart on eight concentric circles A-H. These
concentric circles have respective diameters of 66 mm,
74 mm, 82 mm, 90 mm, 98 mm, 106 mm, 114 mm, and 122 mm.
On these circles, there are to be found respectively 32,
32, 40, 48, 48, 64, 64, and 64 orifices 28. Each orifice
28 has a diameter that is substantially equal to 2.4 mm.
The plate 25 includes a setback 29 having a depth
that is substantially equal to 3 mm. As a result, the
orifices 28 are not directly flush with the surface of
the plate 25 and they are thus protected in part from the
turbulence generated by the fan 12. The shapes of the
orifices 20 and of the setback 29 are adapted so that,
under the effect of the fan 12, the flames generated by
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burning the gas extend radially relative to the central
opening 26 over 360 .
The plate 25 also has two passages 30 for the
igniting electrode 16 and for the flame control device
16a.
The burner of the invention can be varied in
numerous ways without going beyond the ambit of the
invention.
Thus, in a variant that is not shown, the enclosure
2 has a front face and a rear face each of which can be -
opened or closed by a door. Under such circumstances, a
fan 12 is mounted, for example, on at least one of the
side walls 8, and the heater device 11 is placed facing
each fan 12.
In other variants, a plurality of fans and a
plurality of burners are placed on the same wall.
In yet other variants, the oven of the invention has
a protective grid 13 of the kind shown in Figures 5 and
6. Unlike the grid described above, this protective grid
13 is not restricted to an area corresponding to that
facing the fan 12. The protective grid 13 is supported
by a metal frame 40. The frame 40 extends over a major
fraction of the opening in the internal cavity of the
enclosure 2 in a plane parallel to the back wall 7. The
dimensions of the frame 40 are substantially equal to or
greater than the dimensions of the fan 12. Thus, the
cooking atmosphere flows inside the enclosure 2 by being
sucked towards the center of the fan 12 inside the frame
40, and then blown away at the periphery of the fan 12
outside the frame 40. The frame 40 may act as a
reflector. By way of example, the frame 40 is held
within the enclosure 2 by tabs 41 engaging the bottom 9
and the ceiling 10. In some variants, the protective
grid 13 and the frame 40 can be easily removed so as to
be cleaned independently of the oven 1.
