(19)
(11) EP 1 809 946 B1

(12) EUROPEAN PATENT SPECIFICATION

(45) Mention of the grant of the patent:
20.02.2019 Bulletin 2019/08

(21) Application number: 05805769.6

(22) Date of filing: 26.10.2005
(51) International Patent Classification (IPC): 
F23D 14/06(2006.01)
F23D 14/58(2006.01)
(86) International application number:
PCT/IB2005/003188
(87) International publication number:
WO 2006/051368 (18.05.2006 Gazette 2006/20)

(54)

IMPROVED GAS BURNER SYSTEM FOR FOOD COOKING

VERBESSERTES GASBRENNERSYSTEM ZUM KOCHEN VON LEBENSMITTELN

SYSTÈME DE BRÛLEUR A GAZ AMÉLIORÉ POUR LA CUISSON DES ALIMENTS


(84) Designated Contracting States:
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU LV MC NL PL PT RO SE SI SK TR

(30) Priority: 12.11.2004 IT TO20040794

(43) Date of publication of application:
25.07.2007 Bulletin 2007/30

(73) Proprietor: Whirlpool EMEA S.p.A.
20016 Pero (MI) (IT)

(72) Inventors:
  • FALCIONI, Walter
    I-60044 Fabriano (IT)
  • LACCHE', Tiziano
    I-62024 Matelica (MC) (IT)

(74) Representative: Dini, Roberto 
Metroconsult S.r.l. Via Sestriere 100
10060 None (TO)
10060 None (TO) (IT)


(56) References cited: : 
EP-A- 1 298 390
WO-A-2006/005428
FR-A- 1 335 280
FR-A- 2 837 912
US-B1- 6 332 460
WO-A-2004/044490
FR-A- 1 335 280
FR-A- 2 650 369
US-A- 6 135 764
   
       
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description


    [0001] The present invention relates to a gas burner system for food cooking according to the preamble of claim 1.

    [0002] According to the state of the art, burner systems are known which comprise two concentric burners, generally an outer one and an inner one, having a substantially circular shape. The two burners are fed by independent control valves, so that they can be used together or separately in order to achieve good variability and a homogeneous distribution of the heat to be supplied to the cooking containers.

    [0003] The Patent IT1232887 in the name of the same Applicant describes a gas burner system comprising two concentric burners in which gas is mixed with primary air above the cooking top on which the burner system is mounted and through ducts operating as a Venturi tube. In order to allow for a uniform outlet of the air-gas mixture through the holes or apertures of the outer burner, wedge-shaped profiles are obtained on the lower surface of the caps covering the outer burners; however, such wedge-shaped profiles have the drawback of requiring caps having a complex construction as well as an excessive and undesired height.

    [0004] The International Patent Application No. WO2004/044490 by Sabaf, which is to be considered the closest prior art, describes a gas burner system for food cooking comprising a central burner having a first flame crown and at least one outer burner being concentric to the central burner. The air-gas mixture is supplied separately to the burners, in that there is a horizontal chamber providing a radial Venturi effect for mixing primary air and gas. For the purpose of obtaining a uniform outlet of the air-gas mixture through the apertures for the formation and propagation of the flame of the outer burner, it has been thought of using an additional metal element, which is secured to the upper surface of the outer burner by means of screws. In order to improve the outlet of the air-gas mixture through the apertures for the formation and propagation of the flame of the inner burner, another additional metal element is secured to the lower surface of the cap of the central burner.

    [0005] This solution has some drawbacks, too, such as the high number of components making up the entire burner system; this complexity inevitably translates into higher costs.

    [0006] The present invention aims at solving the above-mentioned drawbacks by providing a gas burner system for food cooking having an improved and different construction with respect to any known solutions.

    [0007] In this frame, the main object of the present invention is to provide a gas burner system for food cooking being fitted with economical and effective means allowing for a uniform outlet of the air-gas mixture through the apertures for the formation and propagation of the flame of the concentric burners.

    [0008] Another object of the present invention is to provide a gas burner system for food cooking which offers very good performance by using caps having a simple construction and a reduced height. Such objects are achieved by the gas burner system for food cooking having the features described in the independent claim 1; advantageous aspects of the present invention are detailed in dependent claims.

    [0009] Further objects, features and advantages of the present invention will become apparent from the following detailed description and annexed drawings, which are supplied by way of non-limiting example, wherein:

    Fig. 1 shows an exploded view of the gas burner system according to the present invention;

    Fig. 2 shows a sectional view of the gas burner system according to the present invention;

    Fig. 3 shows a bottom view of the burner system according to the present invention;

    Fig. 4 shows a sectional view of the caps of the burner system according to the present invention.



    [0010] Fig. 1 shows a gas burner system for food cooking, indicated as a whole with reference number 1, comprising a gas supply cup 2 on which an outer burner 3 is placed.

    [0011] The outer burner 3 consists of two half-crowns 3a and 3b, which are separated from each other by a substantially elliptical space; an inner burner 4 is located within said space and on the cup 2. The outer burner 3 is made up of the two half-crowns 3a and 3b, which are separated from each other in order to ensure a proper supply of secondary air to the inner burner 4.

    [0012] A pair of spark plugs C1 and C2 and a pair of thermocouples T1 and T2 are located on the cup 2; in particular, according to the embodiment of Fig. 1, the spark plug C1 and the thermocouple T1 are associated with the outer burner 3, whereas the spark plug C2 and the thermocouple T2 are associated with the inner burner 4.

    [0013] On the outer perimeter of their upper edge, said outer burner 3 and inner burner 4 have main apertures 5 for the outlet and ignition of the gas necessary for forming a flame adapted to heat a cooking container (not illustrated).

    [0014] Reference number 6 indicates secondary apertures being smaller than the main apertures 5 and being preferably located between two main apertures 5; the secondary apertures 6 ensure the propagation of the flame during the ignition of the outer burner 3 and inner burner 4, and allow the flame to stabilize.

    [0015] A first cap 7 is positioned on top of the outer burner 3, whereas a second cap 8 is positioned on top of the inner burner 4, the shape and dimensions of said caps 7 and 8 almost matching those of said outer burner 3 and inner burner 4.

    [0016] For the purpose of reducing the number of parts making up the gas burner system for food cooking being the subject of the present invention, the first cap 7 is preferably made of one piece and is adapted to be positioned onto the two half-crowns 3a and 3b which make up the outer burner 3. As shown in Fig. 1 and Fig. 2, the cup 2 comprises two outer chambers 9 and 10 as well as an inner chamber 11; two nozzles 12 and 13, being connected to a gas supply duct 14, allow the gas to flow into the outer chambers 9 and 10, respectively. A nozzle 15 is connected to a duct (not illustrated) being independent from the duct 14 and allows the gas to flow into the inner chamber 11.

    [0017] The gas flowing into the outer chambers 9 and 10 supplies the outer burner 3, whereas the gas flowing into the inner chamber 11 supplies the inner burner 4; the gas supply for the outer burner 3 therefore takes place independently of that for the inner burner 4.

    [0018] The primary air is taken above a cooking top 16 on which the burner system 1 is mounted, in particular through passages 17 obtained between the cup 2 and the half-crowns 3a and 3b.

    [0019] As shown in Fig. 3, the half-crowns 3a and 3b and the inner burner 4 are connected to one another at the bottom through a channel 18 which runs alongside the passages 17 and ducts 19, 20, 21, which operate as a Venturi tube.

    [0020] Therefore, the channel 18 allows to channel the primary air entering from the passages 17 and to convey it toward the ducts 19, 20, 21, so that it can be mixed inside said ducts 19, 20, 21 with the gas flowing into the outer chambers 9 and 10 and into the inner chamber 11 of the cup 2.

    [0021] The air-gas mixture is prepared within the ducts 19, 20, 21 and rises therein until it reaches the upper end of said ducts, i.e. the holes 19', 20' and 21' (shown in Fig. 1).

    [0022] Fig. 4 shows a sectional view of the caps 7 and 8. The first cap 7 has an inner edge B abutting on the inner edge of the half-crowns 3a and 3b, and an outer edge B1 being located substantially on the apertures 5 and 6 of the half-crowns 3a and 3b; the second cap 8 has an outer edge B2 being located substantially on the apertures 5 and 6 of the inner burner 4.

    [0023] The first cap 7 has a lower surface 24 and an upper surface 25, whereas the second cap 8 has a lower surface 26 and an upper surface 27.

    [0024] In the following, the expression "distal development" will be used to indicate the direction which develops outward from the axis A of the burner system 1.

    [0025] As shown in Fig. 4, the lower surface 24 of the first cap 7 is, in its distal development, substantially inclined upward relative to the bearing plane of the first cap 7, i.e. the horizontal plane in this case. In fact, Fig. 4 clearly shows that the inner edge B of the first cap 7 lies in a horizontal plane being lower than the bearing plane of the outer edge B1.

    [0026] In Fig. 4, it can also be noticed that both the first cap 7 and the second cap 8 are provided with a central zone having a lower surface being substantially flat and substantially parallel to their bearing plane; said central zone is designated B3 for the first cap 7 and B4 for the second cap 8. Therefore, the lower surface 24, 26 of said caps 7, 8 is not inclined evenly along the entire distal development, though it has large zones being clearly inclined upward; one can then say that the lower surface 24, 26 of the caps 7, 8 is substantially inclined upward for its entire distal development.

    [0027] Also the lower surface 26 of the second cap 8 is, in its distal development, substantially inclined upward relative to the horizontal or bearing plane of the second cap 8.

    [0028] Said inclination of the lower surfaces 24 and 26 of the caps 7 and 8 allows to direct the flow of air-gas mixture coming from the ducts 19, 20, 21 upward, in particular toward the apertures 5 and 6 of the burners 3 and 4.

    [0029] In the half-crowns 3a and 3b, in particular at their center and around the holes 19' and 21', there are rises 22 and 23 (shown in Fig. 1); said rises 22 and 23 are provided with an inclined surface being complementary to the inclined lower surface 24 of the first cap 7, and cooperate with said first cap 7 for the purpose of directing the air-gas mixture toward the apertures 5 and 6 of the half-crowns 3a and 3b.

    [0030] Experiments carried out have shown that it is particularly advantageous to manufacture the first cap 7 in such a way that also the lower surface of the outer edge B1 is inclined upward in its distal development, in particular at an angle of inclination α ranging from 4 to 10 degrees relative to the horizontal or bearing plane of the first cap 7.

    [0031] As regards the second cap 8, too, it has been noticed that it is advantageous to manufacture the lower surface of the outer edge B2 in such a way that it is inclined upward in its distal development; in particular, the optimal angle of inclination of the lower surface of the outer edge B2 corresponds to an angle of inclination β ranging from 6 to 14 degrees relative to the horizontal or bearing plane of the second cap 8.

    [0032] Said angles of inclination α and β of the lower surfaces of the outer edges B1 and B2 allow to direct upward both the flow of air-gas mixture, toward the apertures 5 and 6 of the burners 3 and 4, and the flames, which are properly directed toward a cooking container placed on the burner system.

    [0033] As to the upper surface 25 of the first cap 7, it can be noticed in Fig. 4 that its inclination corresponds to that of the lower surface 24; as a matter of fact, the upper surface 25 is also, in its distal development, substantially inclined upward relative to the horizontal or bearing plane of said first cap 7.

    [0034] Said inclination of the upper surface 25 allows to keep the first cap 7, in particular the inner edge B, at an appropriate distance from the apertures 5 and 6 of the inner burner 4, and consequently ensures an adequate operation of both the outer burner 3 and the inner burner 4, while keeping the height of the inner burner 4 low.

    [0035] The features of the present invention, as well as its advantages, are apparent from the above description.

    [0036] In particular, the fact that the lower surface of the caps is, in its distal development, substantially inclined upward relative to the horizontal or bearing plane of the cap allows to direct the flow of air-gas mixture upward, toward the apertures for the formation and propagation of the flame.

    [0037] A further advantage of the present invention is that the lower surfaces of the edges of the caps are so inclined as to allow to direct upward both the flow of air-gas mixture, in particular toward the apertures for the formation and propagation of the flame, and the flames produced by the burners, so as to direct them properly toward a cooking container placed on the burner system.

    [0038] Besides, the upper surface of the first cap being inclined upward in its distal development allows to keep the inner edge of the first cap at a proper distance from the apertures for the formation and propagation of the flame of the inner burner.

    [0039] A further advantage of the present invention is given by the use of a structure which connects the burners at the bottom; such a structure allows to channel the primary air so that it can be mixed with the gas properly.

    [0040] A further advantage of the gas burner system for food cooking according to the present invention is given by the fact that the number of components making up said burner system is lower than that required by the prior art; the remarkable advantages offered by this solution are therefore apparent both from an economical point of view and in terms of reliability of the entire burner system.

    [0041] It is clear that many other variations and applications of the gas burner system for food cooking described herein by way of example are possible for those skilled in the art, as well as that in the practical realization of the invention the components may have shapes and dimensions being different from those described or be replaced with other technically equivalent elements.

    [0042] Among the various possible modifications, the first cap 7 may be manufactured in two pieces adapted to lie on the half-crowns 3a e 3b.

    [0043] A further possible modification consists in using a cup for the outer burner 3 and another cup for the inner burner 4.

    [0044] Furthermore, according to a variant which advantageously allows to reduce the costs of the burner system according to the invention, the two burners 3 and 4 may be fed through a single supply being controlled by a single tap.

    [0045] Said variant may be implemented, for example, by closing the duct (not illustrated) which in the above-described solution of independently fed burners delivers gas into the chamber 11; in this case, the nozzle 15 is connected to the duct 14; in this way the gas flows, through the duct 14 and the respective nozzles 12, 13 and 15, both into the outer chambers 17 and 21 and into the inner chamber 11. According to a preferred embodiment, said connection may be obtained by simply drilling said closed duct in the area corresponding to the nozzle 15.

    [0046] Said latter variant will be immediately recognized by those skilled in the art as a solution which allows to reduce the production costs of the burner system. Compared to the burner system with independent supplies for the two burners 3 and 4, said variant, according to which the burners of the burner system are fed by a common supply, in fact allows to eliminate a control tap, the spark plug C1 and the corresponding thermocouple T1.

    [0047] In conclusion, the present invention also relates to a gas cooking top for food comprising at least one burner and/or one burner system having one or more of the above-described features.


    Claims

    1. Gas burner system (1) for food cooking appliances, comprising a pair of concentric burners (3, 4), the burner system (1) being configured so that the gas to be supplied to the pair of burners (3, 4) is suitably mixed with air taken above the cooking top (16) on which the burner system is mounted (1), so as to form an air-gas mixture for the pair of burners (3, 4), said pair of burners (3, 4) comprising:

    - an outer burner (3) fitted with a first cap (7) having a lower surface (24) and an upper surface (25);

    - an inner burner (4) fitted with a second cap (8) having a lower surface (26) and an upper surface (27);

    the lower surface (24) of said first cap (7) being, in its distal development, substantially inclined upward relative to the bearing plane of said cap (7), so that the flow of air-gas mixture is directed upward, toward apertures (5, 6) on the outer perimeter of the upper edge of said outer burner (3) for the formation and propagation of the flame,
    characterized in that
    said upper surface (25) of the first cap (7) is, in its distal development, substantially inclined upward relative to the bearing plane of said first cap (7), wherein the inclination of said upper surface (25) of the first cap (7) corresponds to the inclination of the lower surface (24) of the first cap (7).
     
    2. Gas burner system (1) according to claim 1, characterized in that said first cap (7) has an inner edge (B) lying in a horizontal plane being lower than the bearing plane of an outer edge (B1) of said first cap (7).
     
    3. Gas burner system (1) according to claim 1, characterized in that at least one of said caps (7, 8) is provided with a central zone (B3) having a lower surface being substantially flat and substantially parallel to the bearing plane of said cap (7, 8).
     
    4. Gas burner system (1) according to claim 1, characterized in that at least one of said caps (7, 8) is provided with an outer edge (B1, B2) whose lower surface is inclined upward in its distal development.
     
    5. Gas burner system (1) according to claim 4, characterized in that said first cap (7) is provided with an outer edge (B1) whose lower surface is inclined upward in its distal development, in particular at an angle of inclination (α) ranging from 4 to 10 degrees relative to the bearing plane of the first cap (7).
     
    6. Gas burner system (1) according to claim 4, characterized in that said second cap (8) is provided with an outer edge (B2) whose lower surface is inclined upward in its distal development, in particular at an angle of inclination (β) ranging from 6 to 14 degrees relative to the bearing plane of the second cap (8).
     
    7. Gas burner system (1) according to claim 4, characterized in that the inclination of the outer edge (B1) of said first cap (7) is lower than the inclination of the outer edge (B2) of said second cap (8).
     
    8. Gas burner system (1) according to claim 1, characterized in that said outer burner (3) comprises two half-crowns (3a, 3b) being separated from each other by a space in order to ensure the necessary supply of secondary air to said inner burner (4) from above the cooking top.
     
    9. Gas burner system (1) according to the previous claim, characterized in that said first cap (7) is made of one piece and is adapted to be positioned onto said half-crowns (3a, 3b).
     
    10. Gas burner system (1) according to claim 8, characterized in that said half-crowns (3a, 3b) comprise rises (22, 23) being provided with an inclined surface being complementary to the inclined lower surface (24) of the first cap (7).
     
    11. Gas burner system (1) according to claim 8, characterized in that said half-crowns (3a, 3b) and said inner burner (4) are connected to one another through a channel (18).
     
    12. Gas burner system (1) according to the previous claim, characterized in that said channel (18) allows to channel the primary air taken above a cooking top (16) through passages (17) obtained between a cup (2) and said half-crowns (3a, 3b).
     
    13. Gas burner system (1) according to the previous claim, characterized in that said channel (18) develops alongside said passages (17) and alongside ducts (19, 20, 21) which operate as a Venturi tube.
     
    14. Gas burner system (1) according to one of the previous claims, wherein said burner system (1) provides an independent gas supply to the two burners (3, 4).
     


    Ansprüche

    1. Gasbrennersystem (1) für Kochgeräte, umfassend ein Paar konzentrische Brenner (3, 4), wobei das Brennersystem (1) konfiguriert ist, so dass das dem Brennerpaar (3, 4) zuzuführende Gas in geeigneter Weise mit Luft vermischt wird, die von oberhalb des Kochfeldes (16) aufgenommen wird, auf dem das Brennersystem montiert ist (1), um ein Luft-Gasgemisch für das Brennerpaar (3, 4) auszubilden, wobei das Brennerpaar (3, 4) umfasst:

    - einen äußeren Brenner (3), welcher mit einer ersten Kappe (7) versehen ist, die eine untere Oberfläche (24) und eine obere Oberfläche (25) aufweist;

    - einen inneren Brenner (4), welcher mit einer zweiten Kappe (8) versehen ist, die eine untere Oberfläche (26) und eine obere Oberfläche (27) aufweist;

    wobei die untere Oberfläche (24) der ersten Kappe (7) in ihrer distalen Entwicklung relativ zur Lagerebene der Kappe (7) im Wesentlichen nach oben geneigt ist, so dass der Fluss von Luft-Gas-Gemisch nach oben gerichtet ist, in Richtung von Öffnungen (5, 6) an dem äußeren Umfang der Oberkante des äußeren Brenners (3) zur Bildung und Ausbreitung der Flamme.
    dadurch gekennzeichnet, dass
    die obere Oberfläche (25) der ersten Kappe (7) in ihrer distalen Entwicklung relativ zur Lagerebene der ersten Kappe (7) im Wesentlichen nach oben geneigt ist, wobei die Neigung der oberen Oberfläche (25) der ersten Kappe (7) der Neigung der unteren Oberfläche (24) der ersten Kappe (7) entspricht.
     
    2. Gasbrennersystem (1) nach Anspruch 1, dadurch gekennzeichnet, dass die erste Kappe (7) eine innere Kante (B) aufweist, die in einer horizontalen Ebene liegt, die niedriger ist als die Lagerebene einer äußeren Kante (B1) der ersten Kappe (7).
     
    3. Gasbrennersystem (1) nach Anspruch 1, dadurch gekennzeichnet, dass mindestens eine der Kappen (7, 8) mit einer zentralen Zone (B3) versehen ist, deren untere Oberfläche im Wesentlichen flach und im Wesentlichen parallel zu der Lagerebene der Kappe (7, 8) ist.
     
    4. Gasbrennersystem (1) nach Anspruch 1, dadurch gekennzeichnet, dass mindestens eine der Kappen (7, 8) mit einer Außenkante (B1, B2) versehen ist, deren untere Oberfläche in ihrer distalen Entwicklung nach oben geneigt ist.
     
    5. Gasbrennersystem (1) nach Anspruch 4, dadurch gekennzeichnet, dass die erste Kappe (7) mit einer Außenkante (B1) versehen ist, deren untere Oberfläche in ihrer distalen Entwicklung nach oben geneigt ist, insbesondere unter einem Neigungswinkel (a) im Bereich von 4 bis 10 Grad relativ zur Lagerebene der ersten Kappe (7).
     
    6. Gasbrennersystem (1) nach Anspruch 4, dadurch gekennzeichnet, dass die zweite Kappe (8) mit einer Außenkante (B2) versehen ist, deren untere Oberfläche in ihrer distalen Entwicklung nach oben geneigt ist, insbesondere unter einem Neigungswinkel (a) im Bereich von 6 bis 14 Grad relativ zur Lagerebene der zweiten Kappe (8).
     
    7. Gasbrennersystem (1) nach Anspruch 4, dadurch gekennzeichnet, dass die Neigung der Außenkante (B1) der ersten Kappe (7) geringer ist als die Neigung der Außenkante (B2) der zweiten Kappe (8).
     
    8. Gasbrennersystem (1) nach Anspruch 1, dadurch gekennzeichnet, dass der äußere Brenner (3) zwei Halbkronen (3a, 3b) aufweist, die durch einen Raum voneinander getrennt sind, um die notwendige Zufuhr von Sekundärluft zum Innenbrenner (4) von oben über dem Kochfeld zu gewährleisten.
     
    9. Gasbrennersystem (1) nach dem vorhergehenden Anspruch, dadurch gekennzeichnet, dass die erste Kappe (7) aus einem Stück gefertigt ist und eingerichtet ist, auf den Halbkronen (3a, 3b) positioniert zu werden.
     
    10. Gasbrennersystem (1) nach Anspruch 8, dadurch gekennzeichnet, dass die Halbkronen (3a, 3b) Erhöhungen (22, 23) aufweisen, die mit einer geneigten Oberflächen versehen sind, die komplementär zu der geneigten unteren Oberfläche(24) der ersten Kappe ist (7).
     
    11. Gasbrennersystem (1) nach Anspruch 8, dadurch gekennzeichnet, dass die Halbkronen (3a, 3b) und der Innenbrenner (4) durch einen Kanal (18) miteinander verbunden sind.
     
    12. Gasbrennersystem (1) nach dem vorhergehenden Anspruch, dadurch gekennzeichnet, dass der Kanal (18) es ermöglicht, die über einem Kochfeld (16) entnommene Primärluft durch Durchgänge (17) zu leiten, die zwischen einem Becher (2) und den genannten Halbkronen (3a, 3b) erhalten werden.
     
    13. Gasbrennersystem (1) nach dem vorhergehenden Anspruch, dadurch gekennzeichnet, dass sich der Kanal (18) neben den Durchgängen (17) und neben Leitungen (19, 20, 21) erstreckt, die als Venturirohr fungieren.
     
    14. Gasbrennersystem (1) nach einem der vorhergehenden Ansprüche, wobei das Brennersystem (1) eine unabhängige Gasversorgung zu den zwei Brennern (3, 4) bereitstellt.
     


    Revendications

    1. Système de brûleurs à gaz (1) pour des appareils de cuisson d'aliment, comprenant une paire de brûleurs concentriques (3, 4), le système de brûleurs (1) étant configuré de sorte que le gaz à fournir à la paire de brûleurs (3, 4) soit mélangé de façon appropriée avec de l'air prélevé au-dessus de la table de cuisson (16) sur laquelle le système de brûleurs est monté (1), de façon à former un mélange air-gaz pour la paire de brûleurs (3, 4), ladite paire de brûleurs (3, 4) comprenant :

    - un brûleur extérieur (3) équipé d'un premier chapeau (7) ayant une surface inférieure (24) et une surface supérieure (25) ;

    - un brûleur intérieur (4) équipé d'un second chapeau (8) ayant une surface inférieure (26) et une surface supérieure (27) ;

    la surface inférieure (24) dudit premier chapeau (7) étant, dans son développement distal, sensiblement inclinée vers le haut par rapport au plan d'appui dudit chapeau (7), de sorte que l'écoulement du mélange air-gaz soit dirigé vers le haut, vers des ouvertures (5, 6) sur le périmètre extérieur du bord supérieur dudit brûleur extérieur (3) pour la formation et la propagation de la flamme,
    caractérisé en ce que
    ladite surface supérieure (25) dudit premier chapeau (7) est, dans son développement distal, sensiblement inclinée vers le haut par rapport au plan d'appui dudit premier chapeau (7), dans lequel l'inclinaison de ladite surface supérieure (25) du premier chapeau (7) correspond à l'inclinaison de la surface inférieure (24) du premier chapeau (7).
     
    2. Système de brûleurs à gaz (1) selon la revendication 1, caractérisé en ce que ledit premier chapeau (7) a un bord intérieur (B) se trouvant dans un plan horizontal qui est inférieur au plan d'appui d'un bord extérieur (B1) dudit premier chapeau (7).
     
    3. Système de brûleurs à gaz (1) selon la revendication 1, caractérisé en ce qu'au moins l'un desdits chapeaux (7, 8) est pourvu d'une zone centrale (B3) ayant une surface inférieure qui est sensiblement plate et sensiblement parallèle au plan d'appui dudit chapeau (7, 8).
     
    4. Système de brûleurs à gaz (1) selon la revendication 1, caractérisé en ce qu'au moins l'un desdits chapeaux (7, 8) est pourvu d'un bord extérieur (B1, B2) dont la surface inférieure est inclinée vers le haut dans son développement distal.
     
    5. Système de brûleurs à gaz (1) selon la revendication 4, caractérisé en ce que ledit premier chapeau (7) est pourvu d'un bord extérieur (B1) dont la surface inférieure est inclinée vers le haut dans son développement distal, notamment d'un angle d'inclinaison (α) allant de 4 à 10 degrés par rapport au plan d'appui du premier chapeau (7).
     
    6. Système de brûleurs à gaz (1) selon la revendication 4, caractérisé en ce que ledit second chapeau (8) est pourvu d'un bord extérieur (B2) dont la surface inférieure est inclinée vers le haut dans son développement distal, notamment d'un angle d'inclinaison (α) allant de 6 à 14 degrés par rapport au plan d'appui du second chapeau (8).
     
    7. Système de brûleurs à gaz (1) selon la revendication 4, caractérisé en ce que l'inclinaison du bord extérieur (B1) dudit premier chapeau (7) est inférieure à l'inclinaison du bord extérieur (B2) dudit second chapeau (8).
     
    8. Système de brûleurs à gaz (1) selon la revendication 1, caractérisé en ce que ledit brûleur extérieur (3) comprend deux demi-couronnes (3a, 3b) qui sont séparées l'une de l'autre par un espace afin de garantir l'alimentation nécessaire en air secondaire audit brûleur intérieur (4) par le dessus de la table de cuisson.
     
    9. Système de brûleurs à gaz (1) selon la revendication précédente, caractérisé en ce que ledit premier chapeau (7) est réalisé d'une seule pièce et est adapté pour être positionné sur lesdites demi-couronnes (3a, 3b) .
     
    10. Système de brûleurs à gaz (1) selon la revendication 8, caractérisé en ce que lesdites demi-couronnes (3a, 3b) comprennent des hauteurs (22, 23) pourvues d'une surface inclinée qui est complémentaire de la surface inférieure inclinée (24) du premier chapeau (7).
     
    11. Système de brûleurs à gaz (1) selon la revendication 8, caractérisé en ce que lesdites demi-couronnes (3a, 3b) et ledit brûleur intérieur (4) sont raccordés les uns aux autres par l'intermédiaire d'un canal (18).
     
    12. Système de brûleurs à gaz (1) selon la revendication précédente, caractérisé en ce que ledit canal (18) permet de canaliser l'air principal prélevé au-dessus d'une table de cuisson (16) à travers des passages (17) obtenus entre une coupelle (2) et lesdites demi-couronnes (3a, 3b) .
     
    13. Système de brûleurs à gaz (1) selon la revendication précédente, caractérisé en ce que ledit canal (18) se développe le long desdits passages (17) et le long de conduits (19, 20, 21) qui fonctionnent comme un tube Venturi.
     
    14. Système de brûleurs à gaz (1) selon l'une des revendications précédentes, dans lequel ledit système de brûleurs (1) fournit une alimentation en gaz indépendante aux deux brûleurs (3, 4).
     




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    Cited references

    REFERENCES CITED IN THE DESCRIPTION



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    Patent documents cited in the description