Gas cooker or cooking hob with a burner having two individually controlled concentric flame crowns

Abstract

 A gas cooker or cooking hob includes at least one burner with two concentric flame crowns, an inner crown (1) and an outer annular crown (2), with a first delivery tube (9) supplying the outer crown (2) and a second delivery tube (10) supplying the inner crown (1), the gas flow in each of said delivery tubes (9, 10) being adjusted in an independent manner through a relevant tap. This arrangement provides complete freedom of adjustment of the flames, since each crown (1, 2) of the burner can be adjusted individually from a minimum to a maximum, whereby both the power and the flame distribution of the burner can be changed at will.

Description

[0001] The present invention relates to gas cookers and cooking hobs, and in particular to a gas cooker or cooking hob having at least one burner with two concentric flame crowns individually controlled by two taps. Reference will be made in the following to a gas cooker, but it is clear that what is being said applies to a cooking hob as well.

[0002] It is known that in cooking hobs or gas cookers preferably at least one of the burners is provided with two concentric flames in order to achieve a better distribution of the heat over the bottom of large-diameter cooking vessels. Prior art burners with two flame crowns have a single delivery and a single tap for controlling the supply, while the two crowns can be made as a single piece or two separate pieces. The control tap allows the gas supply to both crowns only beyond a certain degree of aperture, whereas for small flow rates the gas flows only from one of the crowns, usually the smaller inner one.

[0003] This type of known burner has several drawbacks both from the structural and operative point of view. From the structural point of view it is necessary to provide connecting passages between the outer flame crown and the inner one, which results in a structure more complicated, more expensive and more difficult to clean. Furthermore, it is difficult to achieve an even distribution of the gas between the concentric crowns in operation. As a consequence, it is difficult to achieve a correct balance of the pressures and an adequate inflow of secondary air at the flame areas.

[0004] Using a single tap also makes the use of the burner less flexible, since it is not possible to choose which crown is to be used alone. In fact, the ignition of the outer crown is subordinate to the ignition of the inner one or vice versa, and also the adjustment of the flame on the two crowns is not independent.

[0005] Therefore the object of the present invention is to provide a gas cooker with at least one double crown burner suitable to overcome the above-mentioned drawbacks.

[0006] This object is achieved by means of a gas cooker with at least one double crown burner wherein each crown is fed by its own delivery tube controlled by its own tap.

[0007] A first fimdamental advantage of the gas cooker according to the invention is that it provides complete freedom of adjustment of the flames, since each crown of the double burner can be adjusted individually from a minimum to a maximum. In this way, both the power and flame distribution of the burner can be changed at will.

[0008] A second advantage ofthis gas cooker lies in having a double burner which is structurally simple, since it is substantially made up of two conventional concentric flame-dividing crowns which share the same support and fixing plate which carries the thermocouples and the spark-plugs.

[0009] These and other advantages and characteristics of the gas cooker according to the present invention will be clear to those skilled in the art from the following detailed description of an embodiment thereof, with reference to the annexed drawings wherein:

Fig.1 is a perspective exploded view showing the main elements of the double burner;

Fig.2 is a perspective view of the assembled burner on the gas cooker;

Fig.3 is a top plan view of the delivery tube of the outer crown with the fixing plate;

Fig.4 is a top plan view of the delivery tube of the inner crown with the endpiece for the mounting on said plate; and

Fig.5 is a top plan view of the elements of figs. 3 and 4 in the assembled state.

[0010] With reference to said figures, there is seen that a burner according to the present invention essentially includes an inner flame-dividing crown 1 and an outer annular flame-dividing crown 2, fitted onto a common support 3. Each crown 1, 2 has along its outer periphery a conventional row of holes la, 2a respectively. The outer crown also has a notch 2b for the positioning on support 3 which is provided with a reference peg 3a.

[0011] The fixing plate 4 has a central circular hole 5 for the delivery of gas to the inner crown 1 and an elongate arcuate hole 6 for the delivery to the outer crown 3. In plate 4 there are also formed the seats 7, 7' and 8, 8' for mounting the spark-plugs and the thermocouples, respectively. The presence of two separate pairs of spark-plug/thermocouple is clearly a consequence of the presence of two separate controls for the two crowns, which act in every respect as independent burners yet combinable.

[0012] The supply to the outer crown 2 takes place through a first delivery tube 9 ending at the elongate hole 6. The inner crown 1 is fed through a second delivery tube 10 provided at the tip with an endpiece 11 for the mounting at the circular hole 5, as illustrated in fig.5. The gas flow in each of the delivery tubes 9, 10 is controlled by a relevant tap (not shown).

[0013] It is clear that the above-described and illustrated embodiment of the gas cooker according to the invention is just an example susceptible of various modifications. In particular, the shape of plate 4 and the arrangement of the elements formed therein, such as holes 5, 6 and seats 7, 7', 8, 8', may be changed according to specific needs, as well as the shape and relative size of support 3 and crowns 1, 2.

Claims

1. Gas cooker or cooking hob including at least one burner with two concentric flame crowns, an inner crown (1) and an outer annular crown (2), characterized in that it further includes a first delivery tube (9) supplying the outer crown (2) and a second delivery tube (10) supplying the inner crown (1), each of said delivery tubes (9, 10) being provided with a relevant tap so as to adjust the gas flow in an independent manner.

2. Gas cooker or cooking hob according to claim 1, characterized in that the second delivery tube (10) is provided at the tip with an endpiece (11) for the mounting on a plate (4) at a hole (5) for supplying the inner crown (1), said plate (4) being arranged at the end of the first delivery tube (9) and being provided with a hole (6) for supplying the outer crown (2).

3. Gas cooker or cooking hob according to claim I or 2, characterized in that a spark-plug and a thermocouple are associated with each flame crown (1, 2).

4. Gas cooker or cooking hob according to claim 3, characterized in that the seats (7, 7', 8, 8') for the mounting of the two spark-plugs and two thermocouples are formed in the plate (4).

Drawing