ES2379029A1 - Safety gas cock for a dual burner - Google Patents

Abstract

A safety gas cock for a dual burner, provided with one central flame ring (6) and at least one outer flame ring (8, 8') concentric with said central ring, said cock being of the type comprising two outlets (12, 14) which independently feed said central ring (6) and said outer ring (8, 8'), and with an adjustment cone (29) operable by a rotary knob (32) to adjust gas distribution either towards only said central ring (6) or towards said central ring (6) and towards said outer ring (8, 8') simultaneously, characterised in that said adjustment cone (29) defines a central position in which both said outlets (12, 14) are closed, and from which central position it can be rotated in one direction to adjust the gas flow through a single outlet (12) between a maximum value and a minimum value, and in the other direction to adjust the gas flow through both outlets (12, 14) between a maximum value and a minimum value.

Description

Safety gas tap for a burner double.

The present invention relates to a key of safety gas for a double burner.

Double burners are known. These are concentric burners with a central body or internal burner provided on its periphery with an inner flame ring, and a body annular or external burner provided in its perimeter of one or two concentric flame rings.

In the present description, reference is made to a burner with its outer annular body provided with two rings of flame, however, the indicated is also valid in the case of a burner with its outer body provided with a single ring of call.

In known double burners a first injector is associated with the central body to feed gas to a first Venturi tube, in which a mixture of gas-air to feed the inner flame ring, while a second injector is associated with the annular body to feed gas to a second Venturi tube, in which a gas-air mixture to feed the rings flame outdoors.

The two Venturi tubes are fed from two different outputs of a single key, through which the user controls the different operating modes of the burner, depending on the requirements. These modes of operation are such that both bodies can either be fed outside and inside of the burner to generate flame rings adjustable from a minimum to a maximum, or it can be fed only the inner body to generate only the flame ring interior, adjustable from a minimum to a maximum. In any operating mode always feeds the flame ring inside, therefore the thermocouple safety device is install in proximity with the inner burner body.

In these known burners, the different operating modes are always selected and adjusted by a single button, which as it rotates controls the adjustment cone of The double exit key.

In a first type of key for a burner double, when the button is in the 0º position the burner is closed, while with the button in the 90º position both burner bodies (outside and inside) are fed to flow maximum, then going from 90º to approximately 140º there are a progressive reduction in the flow through the two bodies of burner until the minimum value is reached, then from 140º up to 180º the power to the outer body is interrupted and the flow through the inner body is increased to its maximum value and finally, after passing the position at 180º, the gas flow to through only the inner body decreases to its minimum value, in the top position of the button.

In a second type of key for a burner double, when the button is in the 0º position the burner is closed, while with the button in the 90º position it feeds only the inner burner body at maximum flow, then from 90º to approximately 140º its flow is reduced until it is reaches the minimum value, then from 140º to 180º they feed both burner bodies at their maximum flow at 180º, and finally the gas flow through both burner bodies decreases until its minimum value, at the top position of the button.

As will be revealed, the two types Known double burner keys are difficult to adjust by the user because the adjustment is not immediate or intuitive.

In addition to this inconvenience, the two types known double burner key suffer from another drawback much more important, because when passing from the position of the button corresponding to feed two burners, to the position of the corresponding button to feed only the internal burner, not there is no well defined position in which the feeding of Gas to the outside burner is interrupted reliably. It follows that if the outlet for the gas supply to the external burner does not is completely closed, this state may not be detected by the safety device because the inner ring is fed and the thermocouple is activated. In these circumstances, the amount of gas-air mixture that leaves the outer body is too small to produce an interplay between the two burners with the flames of the inner burner, consequently the Unburned gas escapes into the atmosphere.

WO2005 / 003610 discloses this problem and fix it by preventing the user from moving the button to its critical position. In particular, this document suggests apply a spring to the button key control bar It can interact with a projection provided on the body of the key. When the spring reaches this projection during the operation of the key, the user has to apply a superior force to Turn the button beyond the critical zone.

However, this solution cannot be considered satisfactory both because the user perceives this force as a imperfect operation of the key as because the problems due to the lack of immediate and instinctive perception of its operation

An objective of the invention is to eliminate these inconveniences by providing a security key for a double burner in which the escape of unburned gas is not possible from the outer annular body when the burner operates only with the central flame ring at its minimum.

Another object of the invention is to provide a key in which the adjustment operation by the user is simple and instinctive, and without giving rise to the feeling of an evil functioning.

These and other objectives that will be set manifest from the following description are achieved according to the invention using a safety gas tap for a burner double, as described in claim 1.

Hereinafter, describes in detail a preferred embodiment of the present invention with reference to the attached drawings, in those who:

Figure 1 is a perspective view partially in section of a key according to the invention,

Figure 2 is a section through it taken perpendicular to the axis of rotation of the key,

Figures 3a-3c are about schematic front views of three different positions of the control key to feed both the central body and the burner outer body, showing the plan views corresponding flame ring conditions, and

Figures 4a-4c are about schematic front views of three different positions of the control key to feed only the central body of the burner, showing the plan view of the flame ring conditions corresponding.

As can be seen from the figures, the security key of the invention is intended for the feeding of a traditional double burner, that is, a burner comprising a central body 2 or inner burner and a body annul 4 or external burner, concentric to the first.

The internal burner 2 is provided with a flame ring 6, while the outer burner 4 is provided of two rings of flame 8, 8 ', which leave from its outer periphery and from its inner periphery, although in different types of burner can be provided a single flame ring that comes out only from the outer periphery of the outer burner 4.

Both the internal burner 2 and the burner exterior 4 are fed by the key of the invention, which comprises a body 9 with a gas inlet 10 for connection to the distribution means, and two gas outlets 12 and 14 for the independent power to the two burners 2 and 4.

Input 10 is connected by means of a conduit 16 to a chamber 18, closed by an element 20 of valve associated in a traditional way with an electromagnet 22. This one it is kept in a closed state by means of a spring 24, but it can withdraw from it to open said chamber 18 and connect it to a chamber 26 downstream. In the same way as most keys with a thermocouple safety device, the electromagnet 22 is activated to keep chamber 18 open against the reaction of spring 24, by an electric current generated by a thermocouple 28 located in proximity with the internal burner 2 and sensitive to the flames 6 that come out of the latter.

Chamber 26 downstream communicates with the cavity inside a cone of adjustment 29, rigid with a bar 30 to which an adjustment button 32 is applied.

This bar 32 and cone 29 can also move in an axial direction such as in the case of keys Traditional safety for burners, in order to control manually the temporary movement of electromagnet 22, causing chamber 18 is opened until thermocouple 28 generates current necessary to keep the electromagnet 22 in its open state.

The side wall of the adjustment cone 29 comprises also a pair of openings 34 and 36 which, as the angular position of the cone traditionally set the communication between its inner cavity and openings 38 and 40 provided in the cone seat and connected to the two outputs 12 and 14 gas

The angular amplitude of the openings 34, 36, 38 and 40 is such that it allows gas flow to be regulated according to the burner design data, however this is part of the knowledge of the subject matter expert and requires no explanation additional.

In addition, both outputs 12 and 14 are provided of some traditional 42, 44 leads that guarantee the minimum flow gas supply for both burners 2 and 4, according to the angular position of the button 32 and the rigid cone 29 with the same.

The security key of the invention works as follows:

when button 32 is in its central position, the two outputs 12 and 14 are closed and the electromagnet 22 maintains communication between the chamber upstream of element 20 of valve and chamber 26 downstream closed (see figures 3a and 4a).

To feed the two burners 2 and 4, the user rotates button 32 clockwise until 90º while pressing axially.

This turn of button 32 (see Figure 3b) makes that cone 29 open both outputs 12 and 14 at maximum flow, while that its axial movement causes the valve element 20 to open manually and turn on spark plug 46. This generates the spark and ignite the gas-air mixture that feeds the central burner 2, to generate the inner flame ring 6 which generates the outer flame rings 8, 8 'by interesting.

At the same time, the flames of the inner ring 6 heat thermocouple 28, which generates the current needed to keep the electromagnet attracting and, consequently, the element of open valve, even after releasing button 32.

The flames of both the inner burner 2 and of the outer burner 4 can then be adjusted so traditional turning the button from the position at 90º onwards until you find a stop position (figure 3c) in which you feed both burners to a minimum by means of leads 42, 44 respective.

If the user wishes to have only the burner inside 2 on instead of both burners 2 and 4, they must carry out the same operations described above, but turning button 32 counterclockwise in instead of clockwise.

In this way, the action of openings 34 and 36 provided in adjusting cone 29 and openings 38 and 40 provided in your seat in the body of the key produces the opening only from the outlet 12 that feeds the inner burner 2, making possible would adjust from maximum flow (see figure 4b) to minimum flow (see figure 4c) according to the requirements.

Essentially, the key of the invention eliminates all the inconveniences found in the burner keys double acquaintances, because it excludes any possibility of existence of a critical position in which unburned gas escapes from the outside burner, while at the same time the flames can adjust smoothly and instinctively, with the turn of button 32 in a sense to feed both flame rings, and in the sense opposite to feed only the inner ring.

Furthermore, according to the invention with both positions of button 32 the minimum gas supply is reversed and maximum at one or both burners, that is, the rotation of the button at 90º clockwise or counterclockwise clockwise corresponds to minimum power, while the additional rotation of the button in one direction or another until it stops corresponds to the maximum feeding.

Claims (4)

1. Safety gas key for a double burner, comprising a central flame ring (6) and at least one outer flame ring (8, 8 ') concentric with said central ring, said key being of the type comprising two outputs (12, 14) that independently feed said central ring (6) and said outer ring (8, 8 '), and an adjustment cone (29) that can be operated by a rotary knob (32) to adjust the distribution of the gas either only towards said central ring (6) or simultaneously towards said central ring (6) and towards said outer ring (8, 8 '), characterized in that said adjusting cone (29) defines a central position in which both said outlets (12, 14) are closed, and from said central position it can be turned in one direction to adjust the gas flow through a single outlet (12) between a maximum value and a minimum value, and in the other direction to adjust the gas flow through both outputs (12, 14) between a maximum value and a minimum value. 2. A key according to claim 1, characterized in that the two positions of said adjustment cone (29), that is, those rotated up to approximately 90 ° from the central closed position in both directions, correspond to the maximum feed through a single output (12) and the maximum power through both outputs (12, 14) respectively, while the additional rotation of said adjustment cone (29) in both directions from the position at approximately 90 ° to a stop position corresponds to the gas supply adjustment from maximum to minimum. 3. A key according to claim 1, characterized in that the two positions of said adjustment cone (29), that is, those rotated up to approximately 90 ° from the central closed position in both directions, correspond to the minimum feed through a single output (12) and the minimum supply through both outputs (12, 14) respectively, while the additional rotation of said adjustment cone (29) in both directions from the position at approximately 90 ° to a stop position corresponds to the Gas supply adjustment from minimum to maximum. 4. Key according to one or more of claims 1 to 3, characterized in that a minimum flow bypass (42, 44) is associated with each of the two outputs.