US20080210217A1

US20080210217A1 - Oven or Grill Burner

Info

Publication number: US20080210217A1
Application number: US11/993,883
Authority: US
Inventors: Giorgio Offredi
Original assignee: Castfutura SpA
Current assignee: Castfutura SpA
Priority date: 2005-06-30
Filing date: 2006-06-09
Publication date: 2008-09-04
Also published as: BRPI0610752B1; EP2256408B1; EP1899643B1; WO2007003484A2; EP2256408A2; ITSV20050023A1; MX2007016555A; EP1899643A2; RU2007148519A; BRPI0610752A2; EP2256408A3; WO2007003484A3

Abstract

The invention relates to an oven or grill burner composed of a flat body delimiting an inner chamber and having fastening protrusions, wherein fastening members are composed of at least a tab made of one piece with a flat body wall or walls. In one embodiment, the burner of the present invention includes mountings for fastening a thermocouple and/or igniter and/or a venturi tube that supplies an air and gas mixture, all included as integral members of the burner. The burner of the present invention is shaped such to increase the even distribution of the air/gas mixture to outlet holes and further includes such constructive characteristics that provide for a reduction in the thickness of the metal sheet used for making the burner without compromising burner strength.

Description

FIELD OF THE INVENTION

The present invention relates to an oven or grill burner. More particularly, the present invention relates to a burner that can be used either for an oven or a grill and that includes a flat box body delimiting an inner chamber and fastening protrusions.

BACKGROUND OF THE INVENTION

Burners are known that belong to the so called flat type. These burners can be composed of two half shells and have the advantageous characteristic of including an integrated pilot burner, which is made of one piece by bending the peripheral edges when the two half shells are joined together. 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 type 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 occur between the two half shells.
Flat burners typically have advantages that cannot be found in tubular burners, including 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 require and end-side closing member.

SUMMARY OF THE INVENTION

It is an aim of the present invention to provide a flat burner that can be used either for an oven or a grill and that has improvements over the prior art intended to rationalize and make its manufacturing faster by [[,]] limiting and making assembly steps easier, above all by limiting operations for fastening additional members like connections fastening the burner, thermocouples and igniters, and also by limiting operations for proper positioning.
It is another aim of the present invention to improve a burner of the above type such to limit the total size in favor of the size of the active part actually generating the flame.
It is also an aim of the present invention to improve the distribution of gas and air mixture inside the burner, in order to obtain a more even distribution of the flame.
It is a further aim of the present invention to limit material waste and to allow the use of thinner metal sheets, which are also easier to handle, without reducing the strength of the burner.
The invention reaches the above aims by providing 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.
Advantageously, the fastening tab is provided in a position coinciding with at least a part of two opposite walls of the flat body.
Moreover, the fastening tab is provided coincident with a through aperture made in the burner body.
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 footprint of the burner.
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.
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.
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 to 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.
According to a further advantageous feature that can be provided even individually with respect to above described features, the invention provides an oven or 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, 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 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.
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.
These contacting areas also form spacing members stiffening larger walls of the burner, limiting the thickness of the metal sheet without compromising stability and strength of the burner.
According to a further feature of the invention that can be provided individually and/or in combination with one or more of the above described features, an oven or grill burner is composed of a flat body delimiting an inner chamber and having at least an igniter and/or a flame detecting thermocouple secured to said flat box body by one or more mountings. These mountings for the igniter and/or the flame detecting thermocouple are made of one piece with the burner body.
Further characteristics and improvements are taught in the dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The characteristics of the invention and the advantages derived therefrom will be more apparent from the following detailed description and from 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 FIG. 1.

FIG. 3 is a further perspective view of the burner according to preceding figures but seen at the side opposite to the one of the preceding figures.

FIG. 4 is a plan view of the burner at the upper side thereof.

FIG. 5 is a plan view at the lower side of the burner.

FIG. 6 is a view similar to FIG. 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 FIGS. 1 to 5.

FIG. 9 is a front view of the burner according to FIGS. 1 to 5 at the head side opposite to the fuel/comburent mixture inlet side.

FIG. 10 is a front view of the burner according to FIGS. 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 thereof.

FIG. 12 is a cross-section perspective view of the burner along a transverse plane perpendicular to the upper and lower walls thereof and passing through 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, said shield being omitted.

FIG. 15 is a cross-section view of the burner similar to FIG. 14 and showing 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 is coupled.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

The preferred embodiment of a burner according to the present invention is composed of two half shells mechanically tightly connected together by the mutual bending and pressing of flanges.
It should be understood that the present description of the preferred embodiment is not limitative of the features of a burner according to the present invention, which can be also be manufactured by other techniques.
With reference to the figures, the preferred embodiment of a burner according to the present invention includes 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 typical characteristics of tubular and flat burners. 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. The venturi tube extends beyond said head end of the burner and includes an end housing the fuel supplying nozzle (not shown in detail), which is 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. Accordingly, the separator plane is substantially 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, the 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 and includes a row of aligned holes 501 for supplying the gas/air mixture to the channel, so to provide 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, more particularly at a certain distance from said gas/air mixture inlet ends 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 in greater detail below. Each side wall of the lower half shell 2 has an additional row of holes 601 with a larger diameter, which are also provided at the flame arc forming head area and form the main gas/air mixture outlet holes.
The two half shells are shaped at the air/gas mixture inlet end area in such a way to form the venturi tube wherein the gas and air mixture is produced. Therefore, in this embodiment 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 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.
According to a further feature illustrated in the figures, a half shell 1 has an outer peripheral flange 401 intended to form the outer, side wall of the channel, which forms 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 the 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 the gas/air mixture inlet, 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 flange(s) to form a tight closing.
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 the burner to a surface. 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 is configured to easily reach the fastening tab 3, in order to tighten it by a screw or the like cooperating with a 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 (FIG. 8) 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 plane surface 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 drawing. 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.
According to a further feature of the present embodiment, 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 the burner structure, since they generate a sort of peripheral rib or tabs.
Edges delimiting the through aperture 4 coinciding with the fastening tab 3 also generate a line abutting the two half shells and acting like a spacing member strengthening the flat box body of the burner in the intermediate area of its plan extension.
From the figures, still another advantageous feature of the burner of the present invention is clear. The half shell [[1]] 2 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 the longitudinal sides and along the head end of the burner box body opposite to the gas and air mixture inlet end, forming a 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 602 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 that 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 602.
The rows of holes 501 and 601 are arranged substantially along the outer wall of the half shell [[1]] 2 in the part thereof externally delimiting the U-shaped chamber 602 supplying the gas/air mixture.
A narrowed area is formed in the inner space of the box burner body at the central recess/projection of the half shell [[1]] 2, 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 the 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 pressure inside said U-shaped chamber 602. The venturi tube 5 provided coaxial to the central median axis of the burner particularly leads [[at]] to 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 the outlet holes intended to form the flame, in order to obtain an even flame the entire extension of the burner, and particularly through the longitudinal sides and through the flame arc forming head opposite to the gas/air mixture inlet end.
Still according to a further feature of the present embodiment, along the peripheral edges of the venturi tube 5, the two opposite walls 1 and 2 are suitably shaped 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 provide for the gas/air mixture to pass towards the ending portions of the longitudinal stems of the perimetral U-shaped chamber 602.
It shall be noted that the burner has substantially the same transverse extension in the ending portion extending along the venturi tube 5 and 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.
Since the burner has a quite large plant shape, in order to avoid the large 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 that have a limited extension with respect to the total surface of said walls and that form 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, 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.
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 bending such flanges one upon the other. The parabola or reflecting shield 10 has a central area 110 contacting one of the largest walls 101 or 102 of the box burner body at said holes 9 and has 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 the figures, the central part of the parabola is coupled 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. Such arrangement produces a shape fit which enables an operator to immediately, easily and quickly position the parabola, and in addition it strengthens its fastening in position to the burner. Advantageously, the central part of the parabola intended to be coupled 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.
On each one of the two opposite sides and in an intermediate area of the venturi tube 5, the burner further includes mountings 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 15 and igniter 16 automatically have the proper arrangement with respect to the burner, while when assembling the thermocouple 15 and the igniter 16 only the axial position has to be adjusted, that is the distance at which thermocouple 15 and igniter 16 ends from the burner in order to perfectly operate. By means of this arrangement, it is easier to assemble the burner.
As it can be seen in the figures, the two arms composing the mountings 14 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 of 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 the figures by 1.
As regards the construction of the burner according to the present invention, the embodiment shown, in which 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 some or all construction advantages of the burner described hereinabove can be also had with burners made by different manufacturing techniques.
Each half shell is obtained by cutting and molding a sheet metal blank. In particular, 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 situation, the cutting is made only along two longitudinal edges of the aperture and along only one of the transverse edges. The two half shells manufactured as described above are made such to have coinciding tabs in the area of one aperture, which are intended to be overlapped one with the other so to form the through aperture 4 and the fastening tab 3 of the burner, as well as coinciding half shells of the venturi tube intended to form a venturi tube member 5, and 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 include the areas intended to form spacers, where holes for forming through holes of the burner are provided for engaging fastening means of a parabola or a reflecting shield, and the areas along perimetral outer edges and/or along edges of holes engaging the fastening means of the parabola as well as areas along tabs forming the fastening tab of the mechanical tight connection. Moreover, in this embodiment one of the two half shells 2 is provided with the two rows of holes 501 and 601 and/or with the shaping for generating the perimetral U-shaped chamber distributing the gas/air mixture.
The two half shells thus formed are fastened together and/or in this embodiment are also further partially shaped, for example, at the intermediate spacers and/or fastening tab 3 and/or supporting arms 14 of the igniter and/or the shaping of the U-shaped perimetral chamber distributing the gas/air mixture and in the area of the thermocouple by drawing 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.
From the foregoing description, advantages of the burner of the present invention are clear. First, the particular shape of the box body provides 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 inside the burner limits 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 mounting limits costs and size and makes the fitting of the burner easier. The fact that said mountings have the above described housings for the igniter and/or the thermocouple enables 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, making the fitting of the burner easier.
By arranging the fastening tab in an intermediate position of the plan surface of the burner, useless projections are avoided and the amount of flames and the length of the active part are increased with respect to predetermined dimensions of the oven chamber.
The through aperture at said tab provides for two types of the burner to be applied, one at the bottom of the oven and the other one at the top of it to act as a grill. In this event, during manufacturing the fastening tab 3 may be deformed in a way symmetrically opposite to the one shown in the figures, so to project outwardly on the burner side opposite with respect to the direction shown in the figures. Depending on whether an oven burner or a grill burner is manufactured, 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 symmetrically opposite with respect to said median plane of the burner box body.
Further characteristics such as intermediate contact areas, and the shaping of the two half shells, provide more stiffening and strengthening to the burner structure, enabling the use of thinner metal sheets, which are easier to shape and handle, with less weight, less costs and less wear of manufacturing tools.
A person skilled in the art will appreciate that the invention is not limited to the embodiments described and illustrated herein but may be greatly varied, especially as regards construction, without departing from the guiding principle disclosed above and claimed below.

Claims

1. An oven or grill burner comprising:

a box body delimiting an inner chamber having an upper and a lower walls, and

a fastening protrusion comprising a fastening tab that extends from the box body and that is made of one piece with one or more of the upper or lower walls of the box body.

2. The burner according to claim 1, wherein the fastening tab is provided in a position substantially coinciding with at least a part of two opposite walls of the box body.

3. The burner according to claim 1, wherein the fastening tab is provided coinciding with a through aperture made in the box body.

4. The burner according to claim 2, wherein the fastening tab is provided in a position coinciding with at last a part of the upper and lower walls of the box body.

5. The burner according to claim 2, wherein the fastening tab includes an inclined portion extending from the box body and an ending fastening portion f extending from the inclined portion, and wherein the ending portion is substantially parallel to the opposite walls of the box body.

6. The burner according to claim 3, further comprising a fuel and comburent mixture inlet end, wherein the fuel and comburent mixture inlet end is shaped as a venturi tube and is integrated as one piece with the box body.

7. The burner according to claim 6, wherein the fastening tab is provided in an area of the burner opposite to the fuel and comburent mixture inlet end.

8. The burner according to claim 6, wherein the aperture coinciding with the fastening tab is closed along all perimetral edges.

9. The burner according to claim 6, wherein the box body comprises a first and a second half shells separated along a plane substantially parallel to the upper and/or the lower walls of the box body, and wherein the first and second half shells are 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.

10. The burner according to claim 9, wherein each of the first and second half shells has an aperture which provides the through aperture and into which a tab extends, wherein the apertures and the tabs of the first and second half shells are coincident, wherein the tabs in the first and second half shells are tightly secured by pressing and/or bending perimetral flanges, and wherein the pressing and/or bending provides the fastening tab of the burner.

11. The burner according to claim 9, wherein the outer perimetral flange of the first half shell provides an outer side and a base wall of a perimetral channel that extends without interruption along the longitudinal sides of the burner and also along a head end of the burner opposite to the fuel/comburent mixture inlet end, and wherein the second half shell has a first row of fuel/comburent mixture outlet holes provided along a perimetral band of said second half shell, and wherein the perimetral band delimits the perimetral channel on an inner side.

12. The burner according to claim 11, wherein the first row of holes extends along the perimetral channel inclusive of the head end of the burner opposite to the fuel/comburent mixture inlet end.

13. The burner according to claim 11, wherein a second row of fuel/comburent mixture outlet holes supplies a flame.

14. The burner according to claim 13, wherein the second row of fuel/comburent mixture outlet holes is provided along a side wall of the second half shell beside the first row of holes and is positioned between the first row and the lower wall.

15. The burner according to claim 13, wherein the holes of the first row have a diameter smaller than the holes of the second row.

16. The burner according to claim 11, wherein at the fuel/comburent mixture inlet end the first and the second half shells are shaped such to each form a half of the venturi tube according to a diametral plane of said venturi tube, and wherein side edges of the two halves of the venturi tube are shaped to provide a tight contact one against the other.

17. The burner according to claim 11, wherein a reflecting shield member is fastenable to the upper or the lower wall of the box body, wherein the reflecting shield has a central wall abutting and fastenable to the upper or the lower wall of the burner, and wherein an aperture is provided in the reflecting shield coinciding with the aperture provided in the burner body for the fastening tab.

18. The burner according to claim 11, wherein the box body of the burner is shaped such to provide a perimetral U-shaped chamber extending for a predetermined length of the longitudinal sides of the box body and along the head end, wherein the perimetral U-shaped chamber delimits an intermediate chamber for flow communication between longitudinal stems of the perimetral U-shaped chamber, and wherein the intermediate chamber has an inner height lower than an inner height of the perimetral U-shaped chamber.

19. The burner according to claim 18, wherein the venturi tube extends inside the box body between the longitudinal stems of the perimetral U-shaped chamber.

20. The burner according to claim 11, wherein one of the upper or lower wall of the burner is substantially flat while the opposite wall has a central depression surrounded by a perimetral swelling along the longitudinal sides and along the head end, wherein the upper and lower walls extend towards the end of the box body corresponding to the fuel and carburent inlet end and each comprises a central swelling having an essentially semi-conical shape to provide a longitudinal half of the venturi tube.

21. The burner according to claim 9, wherein the first and the second half shells are manufactured by shaping and cutting a metal sheet blank.

22. An oven or grill burner comprising:

a box body delimiting an inner chamber; and having an upper and a lower walls; and

a reflecting shield fastenable to the upper or the lower wall of the box body,

wherein the box body is provided with a plurality of through openings passing through the upper and the lower walls,

wherein the reflecting shield is provided with a central portion shaped correspondingly to a shape of the upper and/or lower walls and is further provided with fastening tabs each coinciding with one of the through openings, and

wherein the fastening extensions have such a length to project outwardly beyond the side of the box body opposite to the reflecting shield, thereby forming a fastening end bendable against the box body.

23. The burner according to claim 22, wherein the through openings are provided at recesses contacting the upper wall with the lower wall, and wherein the upper wall and the lower wall of the box body are tightly connected along edges delimiting said through openings.

24. The burner according to claim 23, wherein the edges delimiting the through openings in the upper wall and in the lower wall of the box body are provided with flanges for tight connection by bending and by pressing.

25. The burner according to claim 23, wherein the recesses contacting the upper wall with the lower wall are configured to form spacers between said two walls.

26. The burner according to claim 23, further comprising a fastening protrusion that includes a fastening tab made of one piece with one or more of the upper or lower wall of the box body.

27. The burner according to claim 26, wherein the central part of the reflecting shield is shaped to substantially mate a corresponding portion of the upper or lower wall of the burner.

28. The burner according to claim 27, wherein the upper or lower wall includes a central depression, and wherein the reflecting shield in a position coinciding with said depression has a correspondingly shaped projection intended to engage in said depression by a shape fit.

29. An oven or grill burner comprising:

a box body delimiting an inner chamber; and

one or more of an igniter or a flame detecting thermocouple coupled to said box body by one or more mountings,

wherein said one or more mountings are made of one piece with the box body.

30. The burner according to claim 29, wherein said one or more mountings are composed of an arm-like extension projecting outwardly beyond a side edge of the box body at least at a side thereof, wherein the one or more mountings are configured for removably fastening the igniter and/or the thermocouple, and wherein the thermocouple and/or the igniter are supported at a limited intermediate portion of their lengths.

31. The burner according to claim 29, wherein the one or more mountings are oriented such to retain the igniter and/or the thermocouple in a proper operating position with respect to the burner.

32. The burner according to claim 29, wherein the igniter and/or the thermocouple are adjustable axially after coupling with the one or more mountings.

33. The burner according to claim 29, wherein said one or more mountings comprise two supporting arms each branching out from a side edge of the box body, wherein one of the supporting arm is coupled to the igniter and the other supporting arm is coupled to the flame detecting thermocouple, and wherein the two arms are made of one piece with the box body.

34. The burner according to claim 33, wherein the two supporting arms are provided at an end of the box body corresponding to a fuel/comburent mixture inlet end.

35. The burner according to claim 29,

wherein the box body comprises an upper and a lower walls,

wherein a reflecting shield is fastenable to the upper or the lower wall of the box body,

36. The burner according to claim 29,

wherein the box body comprises an upper wall and a lower walls, and

wherein a fastening protrusion comprises a fastening tab that extends from the box body and that is made of one piece with one or more of the upper or lower walls of the box body.

37. An oven or grill burner comprising:

a box body delimiting an inner chamber and having an upper and a lower walls,

wherein the upper and the lower walls are configured to form therebetween a peripheral U-shaped chamber distributing a gas and air mixture along longitudinal sides of the box body and further along a head side opposite to a gas and air mixture inlet end, and

wherein the peripheral U-shaped chamber surrounds an intermediate narrowing chamber having a height smaller than a height of the peripheral U-shaped chamber.

38. The burner according to claim 37, wherein a venturi tube is disposed at the gas and air mixture inlet end and is integral therewith, wherein the venturi tube is closed for an initial portion situated towards the narrowing chamber, and wherein the venturi tube is in flow communication with the narrowing chamber that is disposed centrally and is in flow communication with longitudinal stems of the peripheral U-shaped chamber.

39. The burner according to claim 38, wherein the narrowing chamber comprises transverse spacing members connecting the upper and the lower walls.

40. The burner according to claim 37,

wherein a fastening protrusion comprising a fastening tab extends from the box body and is made of one piece with one or more of the upper or lower walls of the box body,

wherein the fastening tab extends over a through aperture made in the box body,

wherein the reflecting shield is provided with a central portion shaped correspondingly to a shape of the upper and/or lower walls and is further provided with fastening extensions each coinciding with one of the through openings,

wherein the fastening extensions have such a length to project outwardly beyond the side of the box body opposite to the reflecting shield, thereby forming a fastening end bendable against the box body,

wherein one or more of an igniter or a flame detecting thermocouple is coupled to the box body by one or more mountings, and

wherein the one or more mountings are made of one piece with the box body.

41. The burner according to claim 40, wherein a perimetral edge of the through aperture is provided at a certain distance from the venturi tube and deviates sideways the flow of the gas and air mixture.

42. The burner according to claim 38, wherein the venturi tube extends for a certain length inside the narrowing chamber and is in flow communication with the narrowing chamber through side apertures.