[0001] The present invention relates to an oven or grill burner, i.e. a burner that can
be used either for an oven or a grill, comprising a flat box body delimiting an inner
chamber, having fastening protrusions and according to the preamble of claim 1.
[0002] These type of burners are known and belong to the so called flat type. These can
be composed of two half shells and have the advantageous characteristic of having
an integrated pilot burner, which is made of one piece therewith by bending the peripheral
edges when the two half shells are joined. Therefore, any drawback associated to proper
positioning is obviated. The main gas outlet holes and the holes for supplying gas
to the pilot burner are obtained by perforation of one of the two half shells. In
another type of flat burner, each half shell has a corrugated edge opposite to that
of its respective opposite half shell and the gas/air mixture outlet holes are generated
by coupling those edges. Although in this second case the perforation step is avoided,
the holes still have a rather large size, which is further subjected to changes in
the heating step, and sealing problems may also occur between the two half shells.
Flat burners typically have advantages that cannot be found in tubular burners, which
consist in that all connections, and particularly those for the thermocouple and the
igniter, are prearranged in an optimized manner, and there is no need to position
them. Also, unlike tubular burners, flat burners may have inner walls for modulating
gas distribution among the various holes, and the lack of these walls might cause
unevenness problems, especially at low flame levels. Obviously, flat burners do not
have the problem of the end-side closing member.
[0003] The present invention aims at providing a flat burner that can be used either for
an oven or a grill and having improvements intended to rationalize and make faster
its manufacturing, limiting and making easier assembling actions, above all limiting
operations for fastening additional members like connections fastening the burner,
thermocouples and ingniters and limiting also operations for proper positioning. At
the same time the invention aims at improving a burner of the above type such to limit
the total size in favour of the size of the active part actually generating the flame.
[0004] Moreover by means of a proper profile the invention aims at improving the distribution
of gas and air mixture inside the burner in order to obtain a more even distribution
of the flame.
[0005] A further aim is to limit material waste allowing to use thinner metal sheets and
therefore more easy to be treated without reducing the strenght of the burner.
[0006] The invention reaches the above aims by providing an oven or grill burner, according
to the combination of features of the preamble of claim 1 and of the carachterising
part of clami 1, in particular an hove or a grill burner composed of a flat body delimiting
an inner chamber and having a reflecting shield that can be secured to one of the
two upper or lower walls of said flat body, the flat body being provided with a plurality
of through apertures tightly passing the upper wall and the lower wall and the shield
being provided with a central part shaped in a way corresponding to the shape of the
upper and/or lower wall and being provided with fastening tabs each one coinciding
with a corresponding through aperture, which tabs have such a length to project outwardly
beyond the wall of the side opposite to the one adhering to the central part of the
reflecting shield, forming a fastening end that can be bent against said wall.
[0007] Said through apertures are provided at an intermediate area of recesses contacting
the upper wall with the lower wall, the upper wall and the lower wall of the box flat
body being tightly connected along edges delimiting said through apertures.
[0008] These contacting areas also form spacing members stiffening larger walls of the burner
allowing to limit the thickness of the metal sheet without compromising stability
and strength of the burner.
[0009] These features can be provided in combination with further improvements. For example
in a further embodiment the above one can be combined wuth a burner of the above type
wherein at least fastening members are composed of at least a tab made of one piece
with flat body wall or walls.
[0010] Advantageously the fastening tab is provided in a position coinciding with at least
a part of two opposite walls of the flat body.
[0011] Moreover the fastening tab is provided coincident with a through aperture made in
the burner body.
[0012] According to a preferred embodiment, the fastening tab is provided coinciding with
a through aperture made in the burner body and it is positioned inside the plant size
of the burner.
[0013] Said fastening tab has an inclined portion spacing an ending fastening portion from
a burner wall, which inclined portion is substantially parallel to said burner wall
and/or to the median plane of the burner and/or to a fastening wall of the burner.
[0014] According to a further advantageous feature, the burner has a fuel and comburent
mixture inlet end, which end is made like a venturi tube and it is integrated as one
piece in the burner body.
[0015] Advantageously the burner is composed of two half shells separated according to a
plane substantially parallel to the upper and/or lower wall of the burner the two
half shells being tightly secured one with the other by mechanically bending and pressing
perimetral continuous flanges along outer perimetral edges of the two half shells
and along perimetral edges of the aperture coinciding with the fastening tab.
[0016] According to a further advantageous feature that can be provided even individually
with respect to above ones, the invention provides
[0017] Further characteristics and improvements will form the subject of the dependent claims.
[0018] The characteristics of the invention and the advantages derived therefrom will be
more apparent from the following detailed description of the annexed drawings, in
which:
Fig.1 is a first perspective view of a burner according to the present invention.
Fig.2 is a second perspective view of the burner according to figure 1.
Fig.3 is a further perspective view of the burner according to preceding figures but
at the side opposite to the one of the preceding figures.
Fig.4 is a plant view of the burner at the upper side thereof.
Fig.5 is a top plant view at the lower side of the burner.
Fig.6 is a view similar to figure 5 with the reflecting shield omitted.
Fig.7 is a perspective view similar to fig.2 with the reflecting shield omitted.
Fig.8 is a side view of the burner according to figures 1 to 5.
Fig.9 is a front view of the burner according to figures 1 to 5 at the head side opposite
to the fuel/comburent mixture inlet one.
Fig.10 is a front view of the burner according to figures 1 to 5 at the fuel/comburent
mixture inlet end side.
Fig.11 is a perspective view of the burner sectioned along a median longitudinal plane
perpendicular to upper and lower walls.
Fig.12 is a cross-section perspective view of the burner along a transverse plane
perpendicular to the upper and lower walls and passing by apertures fitting fastening
tabs of the reflecting shield.
Fig.13 is a cross-section view of the burner according to a plane perpendicular to
the upper and lower wall thereof, intersecting side arms supporting the flame detecting
thermocouple and the igniter.
Fig.14 is a front cross-section view of the burner along a plane perpendicular to
the upper and lower wall and coinciding with a pair of through apertures for engaging
fastening tabs of the reflecting shield and with said shield omitted.
Fig.15 is a cross-section view of the burner similar to the one of figure 14 and with
said reflecting shield engaging tabs in through apertures and immediately before bending
projecting ends thereof against the burner wall opposite to the wall to which said
reflecting shield adheres.
[0019] Referring to figures, the preferred shown embodiment is of a burner composed of two
half shells mechanically tightly connected together by means of mutual bending and
pressing flanges such as it is common in making box bodies made of metal material.
[0020] As already said in the introduction, such preferred embodiment is not limitative
of features of the burner which can be provided in burners made by other techniques.
[0021] With reference to figures the preferred embodiment of the burner according to the
present invention comprises a first upper half shell and a second lower half shell
indicated by 1 and 2 respectively. In this regard, it shall be noted that the words
upper and lower are used herein in relation to a burner fitted inside the oven on
the bottom wall or immediately beneath the top wall thereof (grill). The two half
shells 1, 2 are elongated and respectively have an upper face 101 and a lower face
102 and peripheral outer edges that can be mechanically and tightly connected to form
a flat, box body which also has an elongated but substantially flat shape, and integrates,
even in the exterior generic aspect, the two typical characteristics of tubular and
flat burners respectively. Two corresponding ends 201, 202 of the upper half shell
1 and of the lower half shell 2 respectively are conformed in such a manner that,
when the two half shells 1, 2 are joined together, they automatically form a flame
arc forming head. The opposite corresponding ends 301, 302 of the shells 1, 2 are
truncated and are conformed in such a manner as to form a venturi tube so that said
head end is intended to form the inlet for supplying fuel and mixing it with comburent
that is air in this case. Venturi tube extends beyond said head end of the burner
with an end housing the fuel supplying nozzle (not shown in details) provided substantially
at one or two combustion air inlet apertures. The junction plane between the two half
shells 1, 2 is substantially parallel both to the bottom and/or the underside and/or
the top of the oven and to the outer faces 101, 102 of the two half shells 1, 2, the
latter being therefore parallel. So the separator plane is practically oriented in
the direction of the fuel/comburent mixture inlet and parallel to the two larger walls
of the box flat body of the burner that is walls defined as the upper and lower walls
indicated by 101 and 102. The two half shells 1, 2 are tightly joined together by
bending continuous peripheral flanges that are subsequently riveted or drawn in order
to form a channel whose outer side wall is opposite to the side wall of the half shell
1, which side wall has a row of aligned holes 501 for supplying the gas/air mixture
to the channel, that forms the pilot burner. Therefore, the pilot burner is made of
one piece with the burner body, whereby there is no need to provide a separate part
to be attached to the tubular body, with all problems associated thereto. The pilot
burner and the row of holes 501 have a substantially U-shaped extension, whose arched
portion extends along the flame arc forming head and whose stems end substantially
at the truncated ends 301, 302 of the two half shells particularly at a certain distance
from said gas/air mixture inlet ends, considering the extension of the burner and
so of the two half shells with the ending portion on the gas and air mixture inlet
end intended to form the integrated venturi tube that will be described below. Each
side wall of the upper half shell 1 has an additional row of holes 601 with a larger
diameter, which are provided at the flame arc forming head area and form the main
gas/air mixture outlet holes.
[0022] The two half shells are shaped at the air/gas mixture inlet end area in such a way
to form the venturi tube wherein said mixture is produced. Therefore, in this case
the half shells of the venturi tube are made of one piece as axial extensions of the
half shells 1, 2 which form the box burner body, whereby, in the assembled condition,
the venturi tube indicated by 5 is coaxial to the box burner body. The tubular body
of the venturi tube, composed of the extensions of the two half shells 1, 2, has a
substantially funnel-like shape, tapering in a direction opposite to the gas/air mixture
inflow, and it extends beyond the corresponding end of the burner with an end 105
supporting the gas supplying nozzle (not shown in details) which has a pair of primary
combustion air intake apertures 205. The venturi tube further has a tubular sleeve
(not shown) which can slide axially along the venturi tube from a position in which
it substantially completely closes said intake apertures 205 to a position in which
it substantially completely opens them, thereby providing adjustment of the stoichiometric
gas/air ratio. Said sleeve has a screw for axially locking it in the proper position.
[0023] According to a further feature resulting from figures, an half shell 1 has an outer
peripheral flange 401 intended to form the outer, side wall of the channel which form
the pilot supplying gas/air mixture acting for spreading the flame triggering the
ignition which is generated by an igniter 16, whose end producing the spark is provided
at the initial area of said channel on one side of the burner and in the end area
thereof associated to gas/air mixture inlet. The flange 401 extends without interruptions
about the outer burner perimeter from said initial end at the igniter 16 to a point
which is diametrically opposite on the other side of the burner passing along the
head end opposite to gas/air mixture inlet one and at which final end there is provided
the sensible point of the flame detecting thermocouple 15. The flange 401 cooperates
with a flange of the half shell 2 connected thereto by riveting and bending such to
form a tight closing.
[0024] In the end area opposite to the gas and air mixture inlet area and at a certain distance
from said end, the burner has a tab 3 for fastening it. The fastening tab 3 is made
of one piece with the box burner body and it is provided at an aperture 4 of the box
burner body passing through it. Such aperture 4 allows to easily reach the fastening
tab 3 in order to tighten it by a screw or the like cooperating with an hole 103 in
said fastening tab 3. The fastening tab 3 has an initial section 203 oriented transverse
to the plane of the corresponding burner wall and it ends with a fastening section
303 oriented substantially parallel to the burner wall 101 and/or to the separator
plane between the two half shells 1, 2. It shall be noted that the fastening tab overlaps
the plant of the burner and it extends by its fastening section 303 at a certain distance
from the burner wall to which it is overlapped. In the shown arrangement, wherein
the burner is composed of two half shells 1, 2 the fastening tab 3 is composed of
two shaped tongues that are obtained from the material of the aperture 4 of each of
the two half shells respectively. The two tongues 701, 702 are pressed together and
are correspondingly shaped to form the fastening tab, moreover perimetral edges of
said tongues 701, 702 have perimetral flanges that tightly close the perimetral edges
of the tongue by bending one upon the other and by pressing and/or by drawning. Moreover
said flanges are provided also along edges delimiting apertures in the wall of the
two half shells 1, 2 forming the through aperture 4 coinciding with said fastening
tab and by means of which the two half shells are tightly joined together along said
edge delimiting said through aperture 4.
[0025] According to a further feature, when the two tongues 701, 702 are joined together
the fastening tab 3 achieves a U shape that aids in stiffening it. Moreover flanges
bent and pressed together along edges aid in stiffening since they generate a sort
of peripheral rib or tabs.
[0026] Edges delimiting the through aperture 4 coinciding with the fastening tab 3 also
generate a line abuting the two half shells acting like a spacing member strenghtening
the flat box body of the burner in the intermediate area of its plant extension.
[0027] From figures still another advantageous feature of the burner of the present invention
is clear. The half shell 1 is shaped such to have a central depression at the outer
side thereof corresponding to an inner projection in the direction of the opposite
half shell 1. The central depression extends such to leave a perimetral band like
a swelling extending without interruption along longitudinal sides and along the head
end of the burner box body opposite to the gas and air mixture inlet end forming an
U-shaped perimetral chamber supplying gas. At the head end associated to the gas/air
mixture inlet and to the venturi tube 5, said perimetral chamber distributing the
gas/air mixture indicated by 802 ends at a certain distance from said head end projecting
also beyond the final end of the venturi tube 5 on the side inside the box burner
body, so the venturi tube enters to such an extent by its final gas/air mixture outlet
end between ending sections of said U-shaped perimetral chamber 802.
[0028] The rows of holes 502, and 602 are arranged substantially along the outer wall of
the half shell 1 in the part thereof externally delimiting the U-shaped chamber 802
supplying gas/air mixture.
[0029] A narrowed area is formed in the inner space of the box burner body at the central
recess/projection of the half shell 1 since the corresponding wall of the half shell
1 does not follow the shape of said recess/projection of the half shell 2 except for
a central shape composed of a central swelling of said half shell 1 provided in the
wall 101 substantially coinciding with the outer recess and inner projection of the
half shell 2 which has a depth that is smaller than the one of said outer recess and
inner projection of the half shell 2. Therefore as shall be noted in section views
the stems of the U-shaped perimetral chamber 602 communicate one with the other by
an intermediate narrowing chamber that helps in balancing and making even the gas/air
mixture pression inside said U-shaped chamber 602. The venturi tube 5 provided coaxial
to the central median axis of the burner particularly leads at said narrowing chamber
at a certain distance from the head end thereof on the side faced towards the gas/air
mixture inlet and in a central position of the burner. Opposite to the gas/air mixture
outlet end from the venturi tube 5 in the central narrowing chamber and at a certain
distance therefrom there is provided the transverse edge of the through aperture 4
coinciding with the fastening tab thus forming a transverse deviation wall for the
gas/air mixture flow towards the two opposite longitudinal stems of the perimetral
U-shaped chamber for supplying the gas/air mixture. Even this feature helps in improving
the even spreading of gas/air mixture flow inside the burner and along outlet holes
intended to form the flame in order to obtain an even flame through all the extension
of the burner and particularly through longitudinal sides and through the flame arc
forming head opposite to the gas/air mixture inlet end.
[0030] Still according to a further feature along peripheral edges of the venturi tube 5,
the two opposite walls 1 and 2 suitably shaped in order to form said venturi tube,
i.e. the two half shells thereof are in contact one with the other in order to avoid
gas/air mixture flow to escape sideways while in the ending portion of the venturi
tube entering inside the burner area corresponding to the central narrowing chamber
T, the venturi tube is open sideways. Therefore such ending portion is made like a
spout and side apertures along opposite side edges allow the gas/air mixture to pass
towards ending portions of longitudinal stems of the perimetral U-shaped chamber 602.
[0031] It shall be noted that the burner has substantially the same transverse extension
in the ending portion extending along the venturi tube 5 beyond the end of the narrowing
chamber T and that sideways of the venturi tube the two walls 101 and 102 are pressed
one against the other in order to make stiffening side tabs 11.
[0032] Since the burner has a quite large plant shape in order to avoid larger burner walls
to be deformed i.e. the upper and lower walls 101 and 102 there are provided spacing
members 8 among them helping in strengthening the box body structure. Said spacers
are advantageously composed of recesses of walls 101 and 102 or only one of these
having a limited extension with respect to the total surface of said walls and forming
mutual contacting areas inside the box body. The amount and distribution as well as
the extension of these contacting areas or contacting islands 8 is determined by the
plant size of the burner and that is width and length and it is selected such not
to compromise the function of the central narrowing chamber indicated by T in section
views.
[0033] Advantageously said contacting areas are provided coinciding with through holes 9
for fastening a reflecting shield or parabola 10. When the burner is composed of two
separate half shells 1 and 2 as in the shown example the edges of said holes 9 are
tightly closed according to the already previously described technique consisting
in bending flanges along edges delimiting the holes and bend one upon the other. The
parabola or reflecting shield 10 has a central area 110 adhering with one of the largest
walls 101 or 102 of the box burner body at said holes 9 having fastening tabs 210
each fitting in a corresponding hole 9 and projecting beyond the opposite wall of
the burner with a fastening end bend against said wall 101 thus causing the coupling
between the parabola 10 and the burner. As can be clearly seen in figures, the central
part of the parabola is adherent preferably to the burner wall having the central
recess and perimetral swelling forming the perimetral U-shaped chamber 602, said central
part of the parabola 10 being shaped complementary to said wall 102. All that produces
a shape fit allowing to immediately, easily and quickly position the parabola and
in addition it strengthenes its fastening in position to the burner. Advantageously
the central part of the parabola intended to adhere to the burner wall 102 has also
an aperture 410 coinciding with the through aperture 4 of the box burner body and
associated to the fastening tab 3.
[0034] On each one of the two opposite sides and in an intermediate area of the venturi
tube 5 the burner further includes a mounting 14 for supporting in a predetermined
position a flame detecting thermocouple 15 and an igniter 16 of the burner. Mountings
14 are made as one piece with the burner and are composed of arm-like projections
of the stiffening tabs 11 sideways of the intermediate portion of the venturi tube
5. Each mounting 14 ends with a pair of transverse tabs 114 wherein a hole 214 is
provided which holes are coaxial one with respect to the other according to an axis
having a direction inclined towards the central axis of the burner and towards the
row of main gas/air mixture outlet holes 601. The igniter 16 and the thermocouple
15 are designed to be introduced axially to length in each of the coaxial holes 214.
Position locking means for example an elastic clip 17 are provided for axially securing
the thermocouple 15 and the igniter 16. Mountings 14 have a position and arrangement
such that the thermocouple and igniter automatically have the proper arrangement with
respect to the burner, while when assembling the thermocouple and the igniter only
the axial position has to be adjusted, that is the distance of thermocouple and igniter
ends from the burner in order to perfectly operate. By means of this arrangement it
is easier to assemble the burner.
[0035] As it can be seen in figures, the two arms composing the mountings 4 are provided
with stiffening means. In the shown embodiment wherein the burner is composed of two
half shells, mountings 14 are composed of extensions of both the half shells intended
to overlap one with the other and are joined together by pressing and by drawing and/or
bending flanges along perimetral edges of said extensions. Moreover, extensions of
half shells 1, 2 forming mountings 14 are shaped such to form mutual spacing areas
thus forming stiffenings as shown in figures by I.
[0036] As regards the construction of the burner according to the present invention, the
embodiment shown and wherein the burner is composed of only two half shells mechanically
and tightly joined together by common techniques for mechanically tightly joining
metal half shells is particularly advantageous even if construction advantages of
the burner there can be also with burners made by different manufacturing techniques.
[0037] Each half shell is obtained by cutting and molding a sheet metal blank. Particularly
the fastening tab is obtained as one piece by cutting the material intended to be
removed in order to make apertures forming the through aperture 4 of the burner coinciding
therewith. In this case the cutting is made only along two longitudinal edges of the
aperture and along only one of the transverse edges. The two half shells as already
described above are made such to have coinciding tabs in the area of one aperture
intended to be overlapped one with the other forming the through aperture 4 and the
fastening tab 3 of the burner, coinciding half shells of the venturi tube intended
to form a venturi tube member 5, coinciding side extensions each one intended to form
at least a mounting supporting an igniter and/or a thermocouple when they are mounted.
Mutual intermediate contacting areas intended to form spacers and at which holes for
forming through holes of the burner are provided for engaging fastening means of a
parabola or a reflecting shield and along perimetral outer edges and/or along edges
of holes engaging fastening means of the parabola as weel as along tabs forming the
fastening tab of the mechanical tight connection. Moreover in this case one of the
two half shells 2 is provided with the two rows of holes 501 and 601 and/or in case
with the shaping for generating the perimetral U-shaped chamber distributing the gas/air
mixture.
[0038] The two half shells thus formed are fastened together and/or in case are also further
partially shaped for example as regards intermediate spacers and/or fastening tab
3 and/or supporting arms 14 of the igniter and/or the shaping of the U-shaped parimetral
chamber distributing the gas/air mixture and of the thermocouple by drawning and/or
molding and/or bending peripheral flanges, while an outer peripheral flange of one
of the two half shell is intended to form the outer side wall delimiting a channel
spreading the ignition spark.
[0039] From what said above advantages of the burner of the present invention are clear.
First the particular shape of the box body allows to obtain an optimum distribution
of the gas/air mixture inside the burner in order to have optimum performances during
the ignition and to generate an optimum and substantially even flow of the output
gas/air mixture from main holes 601. Moreover the insertion of the venturi tube 5
as one piece inside the burner allows to limit the size of the burner, keeping the
size of the flame unchanged relative to its distribution in the longitudinal direction
of the burner. The manufacturing as one piece of the fastening tab and/or of the mountings
of the thermocouple and/or igniter allow to limit costs and size and to make easier
the fitting of the burner. The fact that said mountings have such housings for the
igniter and/or the thermocouple to determine an automatic optimum positioning of the
thermocouple and of the igniter leaving only a degree of freedom in the axial sliding
direction of these members makes more easier the fitting of the burner.
[0040] The fact of arranging the fastening tab in an intermediate position of the plant
surface of the burner avoid useless projections and allows to increase the amount
of flames and the length of the active part with respect to predetermined dimensions
of the oven chamber.
[0041] The through aperture at said tab allow to make two types of the burner to be applied
one to the bottom of the oven and the other one to the top of it in order to act as
a grill. In this case during manufacturing step the fastening tab 3 may be deformed
in a way symmetrically opposite to the one shown in figures and that is in order to
project outwardly on the burner side opposite with respect to the shown one. Depending
on the fact that an oven burner or a grill burner is macnufactured, the substantial
change is to vary the position of the fastening tab from a position offset with respect
to the median plane to a position simmetricaly opposite with respect to said median
plane of the burner box body.
[0042] Further characteristics such as intermediate contact areas, and shaping of the two
half shells give more stiffening and strengthening thereto allowing to use thinner
metal sheets and so more easy to be shaped and to be trated, with less weight, less
costs and less wear of manufacturing tools.
[0043] Obviously, the invention is not limited to the embodiments described and illustrated
herein but may be greatly varied, especially as regards construction. All this without
departure from the guiding principle disclosed above and claimed below
1. Oven or grill burner composed of a flat body delimiting an inner chamber and having
a reflecting shield,
characterized in that
the said reflecting shield can be fastened to one of the two upper or lower walls
of said flat body, the flat body being provided with a plurality of through apertures
tightly passing the upper wall and the lower wall and the shield being provided with
a central portion shaped correspondingly to the shape of the upper and/or lower wall
and being provided with fastening tabs each one coinciding with a corresponding through
aperture, which tabs have such a length to project outwardly beyond the wall of the
side opposite to the one adhering to the central part of the reflecting shield, forming
a fastening end that can be bent against said wall.
2. Burner according to claim 1, characterized in that the through apertures are provided at an intermediate area of recesses contacting
the upper wall with the lower wall, the upper wall and the lower wall of the box flat
body being tightly connected along edges delimiting said through apertures.
3. Burner according to claim 2, characterized in that edges delimiting through apertures in the upper wall and in the lower wall of the
burner flat body are provided with flanges for tight connection by bending and by
pressing.
4. Burner according to claims 2 or 3, characterized in that recesses contacting the upper wall with the lower wall form spacers for said two
walls.
5. Burner according to one or more of the preceeding claims, characterized in that the reflecting shield adheres against the burner wall having a central depression
and in a position coinciding with said recess it has a correspondingly shaped projection
intended to engage in said recess of said burner wall by a shape fit.
6. the said flat body has fastening protrusions, constituted by fastening members that
are composed of at least a tab made of one piece with the wall or walls of the flat
body, which fastening tab is provided in a position coinciding with at least a part
of two opposite walls of the flat body, in particular coinciding with a through aperture
made in the burner body which through aperture is closed along all perimetral edges.
7. Burner according to one or more of the preceding claims, characterized in that is has a fuel and comburent inlet end, which end is made like a venturi tube and
it is integrated as one piece in the burner body,
being the fastening tab provided at least in the area of the burner end opposite to
the fuel and comburent mixture inlet end.
8. Burner according to one or more of the preceding claims, characterized in that the said flat body is composed of two half shells separated along a plane substantially
parallel to the upper and/or lower wall of the burner the two half shells being tightly
secured together by mechanically bending and pressing perimetral continuous flanges
along outer perimetral edges of the two half shells and along perimetral edges of
the aperture.
9. Burner according to one or more of the preceding claims, characterized in that each one of the two half shells has an aperture coinciding with a tab the apertures
and tabs of the two half shells being coincident and the two tabs of the two half
shells being tightly secured by pressing and/or bending perimetral flanges, and in
the mutual fastening state making the fastening tab of the burner.
10. Burner according to one or more of the preceding claims, characterized in that the outer perimetral flange of a first half shell of the two half shells makes the
outer side and bottom wall of a perimetral channel that extends without interruption
along the two longitudinal sides of the burner and at the end opposite to the fuel/comburent
mixture inlet end, while the second half shell has a first row of fuel/comburent mixture
outlet holes provided along the perimetral band of said second half shell delimiting
the channel on the inner side,
Which said first row of holes extends also along the head end of the burner opposite
to the fuel/comburent mixture inlet end.
11. Burner according to one or more of the preceding claims, characterized in that it has a row of fuel/comburent mixture outlet holes generating the flame, which said
row of fuel/comburent mixture outlet holes is provided along the side wall of the
second half shell beside the first row of holes and at such an height that holes come
out above the free upper edge of the perimetral channel,
having the holes of the first row a diameter smaller with respect to fuel/comburent
mixture outlet holes for generating the flame.
12. Burner according to one or more of the preceding claims, characterized in that at the fuel/comburent mixture inlet end the first and the second half shells are
shaped such to form each one an half of a venturi tube according to a diametral plane
of said venturi tube, side edges of the two halves of the venturi tube being shaped
in each half shell such to be tightly in contact.
13. Burner according to one or more of the preceding claims, characterized in that the box body of the burner is shaped such to make a perimtral U-shaped chamber extending
for a certain length of longitudinal sides and along the head side opposite to the
fuel/comburent mixture inlet one and which chamber delimits an intermediate chamber
for communication of stems of the perimetral U-shaped chamber having an inner height
lower than the height of the perimetral U-shaped chamber.
14. Burner according to one or more of the preceding claims, characterized in that the venturi tube ends by its end inside the burner beyond the head end of longitudinal
stems of the perimetral U-shaped chamber.
15. Burner according to one or more of the preceding claims, characterized in that one of the two upper and/or lower walls of the burner is substantially a flat one,
while the opposite wall has a central depression surrounding by a perimetral swelling
along longitudinal sides and along the head edge opposite to the fuel/comburent mixture
inlet head end, while the two walls extend towards the head end corresponding to the
fuel/comburent inlet each one with a central swelling having the shape of opposing
double frustum of cone and with a semicircular cross-section which central swelling
forms the corresponding half of the venturi tube.