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EP 0 392 523 B1 |
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EUROPEAN PATENT SPECIFICATION |
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Mention of the grant of the patent: |
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17.03.1993 Bulletin 1993/11 |
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Date of filing: 11.04.1990 |
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International Patent Classification (IPC)5: F24C 3/08 |
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Gas burner for food cooking.
Gasbrenner für Kocher.
Brûleur à gaz pour appareil de cuisson.
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Designated Contracting States: |
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DE ES FR GB NL |
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Priority: |
14.04.1989 IT 6727989
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Date of publication of application: |
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17.10.1990 Bulletin 1990/42 |
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Proprietor: MERLONI ELETTRODOMESTICI S.p.A. |
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I-60044 Fabriano (AN) (IT) |
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Inventor: |
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- Antonini, Luciano
I-62032 Camerino (MC) (IT)
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References cited: :
BE-A- 902 029 DE-A- 1 808 475 FR-A- 2 507 743
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DE-A- 1 454 262 FR-A- 1 561 594 GB-A- 1 347 249
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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).
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[0001] The present invention relates to a gas burner for food cooking, comprising a sensor
of the temperature reached by food contained in heated containers.
[0002] A burner of the type indicated is known for example by FR-A-1.561.594 or by the Italian
patent for industrial invention nr. 1.159.956.
[0003] Such patent describes a gas burner for the cooking of food contained in. containers,
to which there is associated an automatic control system of the temperature reached
by the food, by means of a temperature sensor that is kept in contact with the bottom
of the heated container.
[0004] Such a burner however presents some disadvantages, because it has been verified that
the primary air quantity for the air-gas mixture, taken from the lower part of the
burner, can be of some difficulty to control, with consequent mixing incostancy, bad
combustion, or even extinction of the flame, expecially in the minimum position.
[0005] Gas burners wherein the primary air for the air-gas mixture is taken from above the
cooking plane are also known (see for example DE-A-1.808.475), but their embodiments
do not allow for the arrangement of a temperature sensor in a satisfactory position.
[0006] The invention is based on the recognition of the fact that it is harmful to take
the air from a zone where the temperature can be altered due to the presence of an
underlying oven, or other heat sources eventually connected with the automatic control
system; and that an other troubling, element is represented by taking the air from
a zone in which turbolence is present, both for thermic convection effect, both in
case that the system needs a forced ventilation to assure that electronic components
do not reach dangerous temperatures. Purpose of the present invention is thus that
to obviate to the indicated disadvantages of the known systems, teaching as it is
possible to obtain a burner of the described type that even inspite of its simplicity
assures mixing costancy of air and gas and thus a perfect combustion.
[0007] To achieve such purpose the present invention has for object a gas burner for food
cooking, fixed to a cooking plane, comprising a sensor of the temperature reached
by food contained in heated containers, said sensor being arranged in a vertical passage
obtained in the burner's body, whereby the burner in use shows a vertical axis of
symmetry, characterised by the fact that it comprises an air-gas mixing component
arranged inside the burner's body in a vertical position proximate to said vertical
passage for said sensor, said vertical passage and said air-gas mixing component being
substantially centered in respect of the vertical axis of symmetry of the burner's
body, and by the fact that the primary air for the air-gas mixture is taken from above
the cooking plane.
[0008] Further purposes and advantages of the present invention will be clear from the detailed
description which follows and the annexed drawings, which are supplied only as an
explanatory and not limiting example, wherein:
- figure 1 shows in section the burner according to the invention;
- figure 2 shows the flame-separator of the burner of figure 1;
- figure 3 shows the actual burner element of the device according to the invention;
- figure 4 shows the sump of the burner of figure 1;
- figure 5 shows the temperature sensor of the burner of figure 1.
[0009] In figure 1, which shows in section the burner according to the invention, reference
number 1 indicates the first element of the burner, or flame-separator element; reference
number 2 indicates the second element of the device, or actual burner; reference number
3 indicates the third element of the burner, or air-gas mixing sump; reference number
4 indicates the temperature sensor; reference number 5 indicates the gas entry, reference
number 11 indicates the injector that feeds the gas to the mixing sump, or air-mixing
sump; reference number 6 indicates the entry slot for the mixing primary air; reference
number 7 indicates one of the holes used to fix the burner to the cooking plane.
[0010] The entry slot 6 for the air is a circular one; the air entering by it is mixed in
the sump 3 with the gas entering by the entry 5; the mixture rises until the flame-separator
1; the flames exit through the holes 8.
[0011] The cooking container is supported in a known way by a support grill, not represented
in the figures and which is arranged around the burner.
[0012] As shown the sensor 4 is disposed in a vertical passage, passing through the elements
1, 2 and 3 of the burner, and is secured inferiorly to the sump 3 by means of special
screw, whose seat is shown in the figure.
[0013] The sensor 4 is partially shielded from the heat radiated by the flames owerflowing
through the holes 8 by means of the shield realized by the hollow cylindrical particular
12, while it is shielded from the conduction heat of the burner by means of the air
flow which crosses the chimney 13.
[0014] Figure 2 shows in section and in view the flame-separator element 1 of the burner
according to the invention; the reference number 9 indicates eight equidistant centring-teeth,
arranged on a circumference.
[0015] Figure 3 shows in section the actual burner 2 of the device according to the invention.
[0016] From figure 1 it is possible to realize how the vertical passage for the temperature
sensor, obtained in the elements 2 and 3, is also used for the vertical positioning
of said second element in respect of said third element, so determining also the height
of the entry slot for the primary air to be mixed with the gas.
[0017] In figure 4, which shows in section the sump 3 of the burner according to the invention,
it is shown, indicated with reference number 10, a centring tooth, which ingages in
a special recess obtained in the burner element 2, as shown in figure 1; the tooth
10 is in effect a prolongation of the wall of the vertical passage for the sensor
4.
[0018] The tooth 10 assures therefore the centring of the gas jet that exits through the
gas injector 11 in respect of the Venturi tube indicated in figure 1 with reference
number 14.
[0019] In figure 5 there is shown the temperature sensor 4 of the burner according to the
invention.
[0020] The sensor 4 superiorly includes a spring-cap, so that it is pressed against the
cooking container, and internally, also superiorly, the element sensitive to the temperature,
which is a resistor with negative temperature coefficient (NTC); such resistor is
inserted in a suitable control electronic circuit, of known type, to mantain the container
at a constant temperature.
[0021] The mechanic support having the purpose to house the element sensitive to the temperature
(NTC) is secured to the third element of the burner 3 by means of a threaded hole
15 and a screw not shown in the figure.
[0022] To minimize the 'by contact' heat transmission to the mechanic support of the element
(NTC) coming from the third element 3 of the burner, in the point of contact of the
two particulars, protruding point-shaped elements, such as pyramidal protrusions,
are provided to minimize the zone of contact.
[0023] The characteristics of the described burner are clear from the given description
and the annexed drawings.
[0024] Also clear are the advantages of the balancing burner object of the present invention.
[0025] Specifically, they are represented by the fact that a constant supply of primary
air quantity is warranted by simple means, assuring of consequence a perfect combustion
in all the operation conditions.
[0026] It is possible to realize the centring of the gas injectior 11 in respect of the
Venturi tube 14 by means of a hollow obtained in the particular 3 of the burner and
a reference tooth obtained in the particular 2 of the burner.
1. Gas burner for food cooking, fixed to a cooking plane, comprising a sensor (4) of
the temperature reached by food contained in heated containers, said sensor (4) being
arranged in a vertical passage (12, 13) obtained in the burner's body (1, 2, 3), whereby
the burner in use shows a vertical axis of symmetry, characterised by the fact that
it comprises an air-gas mixing component (14) arranged inside the burner's body (1,
2, 3) in a vertical position proximate to said vertical passage (12, 13) for said
sensor (4), said vertical passage (12, 13) and said air-gas mixing component (14)
being substantially centered in respect of the vertical axis of symmetry of the burner's
body (1, 2, 3), and by the fact that the primary air for the air-gas mixture is taken
from above the cooking plane.
2. Gas burner according to claim 1, characterised by the fact that the burner's body
comprises in the given order, from the top to the bottom, a flame-separator element
(1), an intermediate element (2) which is the actual burner and a sump-shaped element
(3) wherein the mixing of the gas with the air occurs.
3. Gas burner according to claim 2, characterised by the fact that said vertical passage
(12, 13) for said sensor (4) is realized through said flame-separator (1), said intermediate
(2) and said sump-shaped (3) elements.
4. Gas burner according to claim 2, characterized in that it comprises a circular entry-slot
(6) for the primary air which has to be mixed with the gas, defined between said intermediate
(2) and said sump-shaped (3) elements.
5. Gas burner according to claim 3, characterised by the fact that said vertical passage
(12, 13) is also used for the centring of said intermediate element (2) in respect
of said sump-shaped element (3).
6. Gas burner according to claim 3, characterised by the fact that said vertical passage
(12, 13) is also used for the vertical positioning of said intermediate element (2)
in respect of said sump-shaped element (3), in order to determine the eight of said
entry-slot (6) for the primary air which has to be mixed with the gas.
7. Gas burner according to claim 3, characterised by the fact that said vertical passage
(12, 13) comprises means for shielding at least partially the heat that could influence
said sensor (4) both through irradiation and through conduction by the burner.
8. Gas burner according to claim 7, characterised by the fact that said means includes
a hollow cylindrical element (12) which protrudes from said flame-separator element
(1) and a chimney-path (13) which creates a flow of ascending air that cools said
sensor (4).
9. Gas burner according to claim 7, characterised by the fact that it includes protruding
point-shaped elements (16) in the point of fixation of said sensor (4) to said sump-shaped
element (3).
10. Gas burner according to claim 8, characterized by the fact that said hollow cylindrical
element (12) and said air-gas mixing component (14) are obtained in said intermediate
element (2).
11. Gas burner according to claim 2, characterised by the fact that it provides centring
means (10) between said intermediate element (2) and said sump-shaped element (3)
for mantaining constant the positioning of said air-gas mixing component (14), which
is part of said intermediate element (2), in respect of a gas injector (11), which
is part of said sump-shaped element (3).
12. Gas burner according to claim 1, characterized in that said air-gas mixing component
(14) is a tube of the Venturi type.
1. Gasbrenner für Kocher, befestigt an einer Kochfläche, bestehend aus einem Sensor (4)
zur Erfassung der Temperatur, die die in dem erhitzten Kochgefäß enthaltenen Speisen
erreichen, welcher Sensor (4) in einem vertikalen Durchgang (12, 13) im Brenner (1,
2, 3) angeordnet ist, wobei der sich im Gebrauch befindliche Brenner eine vertikale
Symmetrieachse aufweist, dadurch gekennzeichnet, daß er eine Luftgasmischeinrichtung (14) enthält, die innerhalb des Brenners (1,
2, 3) in vertikaler Lage nahe beim vertikalen Durchgang (12, 13) für den Sensor (4)
angeordnet ist, welcher vertikale Durchgang (12, 13) und welche Luftgasmischeinrichtung
(14) im wesentlichen in bezug auf die vertikale Symmetrieachse des Brenners (1, 2,
3) zentrisch angeordnet sind, und daß die Primärluft für das Luftgasgemisch von der
Kochfläche abgenommen wird.
2. Gasbrenner nach Anspruch 1, dadurch gekennzeichnet, daß der Brenner in der gegebenen
Anordnung von oben nach unten ein Flammentrennelement (1), ein Zwischenelement (2),
das der eigentliche Brenner ist, und ein wannenförmiges Element (3) aufweist, in dem
das Gas mit der Luft gemischt wird.
3. Gasbrenner nach Anspruch 2, dadurch gekennzeichnet, daß der vertikale Durchgang (12,
13) für den Sensor (4) durch das Flammentrennelement (1), das Zwischenelement (2)
und das wannenförmige Element (3) führt.
4. Gasbrenner nach Anspruch 2, dadurch gekennzeichnet, daß er einen kreisförmigen Eintrittsschlitz
(6) für die Primärluft aufweist, die mit dem Gas zu mischen ist, der durch den Abstand
zwischen dem Zwischenelement (2) und dem wannenförmigen Element (3) festgelegt ist.
5. Gasbrenner nach Anspruch 3, dadurch gekennzeichnet, daß der vertikale Durchgang (12,
13) ebenfalls für die Zentrierung des Zwischenelementes (2) in bezug auf das wannenförmige
Element (3) vorgesehen ist.
6. Gasbrenner nach Anspruch 3, dadurch gekennzeichnet, daß der vertikale Durchgang (12,
13) auch für die vertikale Positionierung des Zwischenelementes (2) in bezug auf das
wannenförmige Element (3) vorgesehen ist, um die Höhe des Eintrittsschlitzes (6) für
die Primärluft, die mit dem Gas zu vermischen ist, zu bestimmen.
7. Gasbrenner nach Anspruch 3, dadurch gekennzeichnet, daß der vertikale Durchgang (12,
13) Vorrichtungen zumindest zur teilweisen Abschirmung der Hitze aufweist, die auf
den Sensor (4) sowohl durch Abstrahlung als auch durch Weiterleitung durch den Brenner
einwirken kann.
8. Gasbrenner nach Anspruch 7, dadurch gekennzeichnet, daß die Vorrichtungen ein hohlzylindrisches
Element (12) aufweisen, das aus dem Flammentrennelement (1) und einem Kaminpfad (13)
hervorsteht, der einen Strom aufsteigender Luft zur Kühlung des Sensors (4) erzeugt.
9. Gasbrenner nach Anspruch 7, dadurch gekennzeichnet, daß er thervorstehende schwertförmige
Elemente (16) am Befestigungspunkt des Sensors (4) an dem wannenförmigen Element (3)
aufweist.
10. Gasbrenner nach Anspruch 8, dadurch gekennzeichnet, daß das hohlzylindrische Element
(12) und die Luftgasmischeinrichtung (14) aus dem Zwischenelement (2) herausgearbeitet
sind.
11. Gasbrenner nach Anspruch 2, dadurch gekennzeichnet, daß er Zentriervorrichtungen (10)
zwischen dem Zwischenelement (2) und dem wannenförmigen Element (3) aufweist, um die
Position der Luftgasmischeinrichtung (14), die Teil des Zwischenelementes (2) ist,
in bezug auf einen Gasinjektor (11), der Teil des wannenförmigen Elementes (3) ist,
zu fixieren.
12. Gasbrenner nach Anspruch 1, dadurch gekennzeichnet, daß die Luftgasmischeinrichtung
(14) eine Röhre des Typs Venturi ist.
1. Brûleur à gaz pour la cuisson des mets, fixé à un plan de cuisson, comportant un capteur
(4) de la température atteinte par le mets contenu dans les récipients chauffés, ledit
capteur (4) étant disposé dans un passage vertical (12, 13) réalisé dans le corps
(1, 2, 3) du brûleur, le brûleur présentant en service un axe vertical de symétrie,
brûleur caractérisé par le fait qu'il comporte un composant (14) pour mélange air-gaz
disposé à l'intérieur du corps (1, 2, 3) des brûleurs en une position verticale proche
dudit passage vertical (12, 13) prévu pour ledit capteur (4), ledit passage vertical
(12, 13) et ledit composant (14) pour mélange air-gaz étant sensiblement symétriques
par rapport à l'axe vertical de symétrie du corps (1, 2, 3) du brûleur, et par le
fait que l'air primaire pour le mélange air-gaz est prélevé au-dessus du plan de cuisson.
2. Brûleur à gaz selon la revendication 1, caractérisé par le fait que le corps du brûleur
comporte, dans l'ordre indiqué, de haut en bas, un élément (1) séparateur de flamme,
un élément intermédiaire (2) qui est le brûleur effectif et un élément (3) en forme
de réceptacle dans lequel se produit le mélange du gaz avec l'air.
3. Brûleur à gaz selon la revendication 2, caractérisé par le fait que ledit passage
vertical (12, 13) pour ledit capteur (4) est réalisé à travers ledit séparateur de
flamme (1), ledit élément intermédiaire (2) et ledit élément en forme de réceptacle
(3).
4. Brûleur à gaz selon la revendication 2, caractérisé par le fait qu'il comporte, pour
l'air primaire qui doit se mélanger avec le gaz, une fente d'entrée circulaire (6)
définie entre ledit élment intermédiaire (2) et ledit élément en forme de réceptacle
(3).
5. Brûleur à gaz selon la revendication 3, caractérisé par le fait que ledit passage
vertical (12, 13) sert également à centrer ledit élément intermédiaire (2) par rapport
audit élément en forme de réceptacle (3).
6. Brûleur à gaz selon la revendication 3, caractérisé par le fait que ledit passage
vertical (12, 13) sert également pour positionner verticalement ledit élément intermédiaire
(2) par rapport audit élément en forme de puisard (3), de façon à déterminer la hauteur
de ladite fente d'entrée (6) pour l'air primaire qui doit se mélanger avec le gaz.
7. Brûleur à gaz selon la revendication 3, caractérisé par le fait que ledit passage
vertical (12, 13) comporte des moyens pour faire écran au moins partiellement à l'égard
de la chaleur qui pourrait influencer ledit capteur (4) à la fois par rayonnement
et par conduction par le brûleur.
8. Brûleur à gaz selon la revendication 7, caractérisé par le fait que lesdits moyens
comportent un élément cylindrique creux (12) qui dépasse dudit élément (1) séparateur
de flamme et un chemin formant cheminée (7) qui crée un flux d'air ascendant qui refroidit
ledit capteur (4).
9. Brûleur à gaz selon la revendication 7, caractérisé par le fait qu'il comporte des
éléments ponctuels débordants (16) au point de fixation dudit capteur (4) sur ledit
élément en forme de réceptacle (3).
10. Brûleur à gaz selon la revendication 8, caractérisé par le fait que ledit élément
cylindrique creux (12) et ledit composant (14) pour mélange air-gaz font partie dudit
élément intermédiaire (2).
11. Brûleur à gaz selon la revendication 2, caractérisé par le fait qu'il comporte des
moyens de centrage (10), prévus entre le dit élément intermédiaire (2) et ledit élément
en forme de réceptacle (3) pour maintenir constant le positionnement dudit composant
(14) pour mélange air-gaz, qui fait partie du dit élément intermédiaire (2), par rapport
à un injecteur à gaz (11), qui fait partie dudit élément en forme de réceptacle (3).
12. Brûleur à gaz selon la revendication 1, caractérisé par le fait que ledit composant
(14) pour mélange air-gaz est un tube de type Venturi.