GB2168790A - Improvements in taps for gas burners - Google Patents

Abstract

A tap for gas burners in cookers and like appliances comprises a body (1) containing a gas inlet aperture (9) and a through outlet aperture (2) containing a rotary cylindrical plug (19) with a front chamber (23) and a side port (22). A bore (5) provided with a minimum-regulating needle valve and intersected by the inlet aperture (9) near the zone where the tip of the needle of the valve is located ends in the middle zone of another bore (6) whose inlet may be closed by means of a ball (29), this second bore being intersected at its end by the through aperture (2) in the zone thereof where the side port (22) of the plug (19) is situated, in order to form a minimum flow bypass separate from the main admission of gas to the tap. An elastic liner (12) has longitudinal ribs which can seal off the bypass and main-inlet (17, 18) and preferably also annular ribs which act as O-rings. <IMAGE>

Description

SPECIFICATION Improvements in taps for gas burners The present invention relates to a tap for gas burners in cookers and the like appliances, which is equipped with means for regulating the maximum and minimum gas flows in a simple and effective manner.

The tap in question is of the type consisting of a body having a foot provided with means for fastening to the gas manifold, in which body is formed a gas inlet aperture intersecting at right angles with a through outlet aperture, the body also containing a rotary cylindrical distributor having a front chamber coinciding with the outlet aperture and having a side mouth on said chamber, while in addition the body incorporates the corresponding control and retaining elements.

It is an object of the present invention to improve the construction of the known type of tap for gas burners, making them easier to construct and maintain in use.

The tap for gas burners of the present invention is essentially characterized in that a bore is provided into which is screwed a minimum regulating needle valve and which near the zone where the tip of the needle is located is intersected by the body inlet aperture, ending in the middle zone of another bore whose inlet mouth is preferably closed by means of a ball inserted under pressure and which in turn is intersected at its end by the through aperture of the tap in the zone of said aperture where the side mouth of the distributor is situated, thus forming a minimum access separate from the main admission of gas to the tap.

At the height of the side mouth, the distributor referred to is covered by a band of elastic material fixed to the body and having a gas inlet and a minimum passage facing the corresponding elements of the tap, this band being the element which provides a seal for the tap both in relation to gas leaks and in relation to the various closure positions and different flows, all of these being obtainable respectively either because the side mouth of the distributor is not in alignment with any of the passages in the body or because it is in alignment with the main inlet or with the minimum access or with both at the same time.

The band of elastic material, which is located in a zone where the tap has an appropriate diameter, has two diametrically opposite cylindrical protuberances, one closed and the other open, the open protuberance fitting into the main aperture for admission of gas to the tap and the closed protuberance fitting into a blind end of the aperture, formed by intersection with the through aperture already mentioned.

More specifically, on the one hand the elastic band has internally, on the perimeter of its two ends, respective semitoric ribs which are compressed between the distributor and the tap body, thus sealing any gaps which may exist. On the other hand, it has at least three compressed longitudinal ribs of the same shape, which extend from one end to the other and which borderthe gas inlet and the minimum passage, sealing the flow of gas in relation to the respective consumptions.

The present invention will now be described in greater detail by way of example with reference to the accompanying drawings, wherein: Figure lisa rear view in elevation of the body of a preferred form of tap for a gas burner; Figure2 is a view in section through the plane ll-ll in Figure 4; Figure 3 is a view through the plane Ill-Ill in Figure 4; Figure 4 is a view in longitudinal section of the tap body without the distributor, the elastic band and the bypass needle; Figure 5 is a front view of the tap body; Figure 6 is a front view in elevation of the elastic band; Figure 7 is a view in longitudinal section of the actual elastic band; Figure 8 is a view in section through the plane VIII-VIII in Figure 4; Figure 9 is a view in section through the plane IX-IX in Figure 4;; Figure 10 is a front view in elevation of the distributor.

Figure 11 is a view in longitudinal section of the distributor; Figure 12 is a view in longitudinal section of the tap complete with all its components fitted; Figure 13 is a view in section through a transverse plane XIII-XIII, in relation to the plane of the preceding Figure, with the distributor in the minimum consumption position; Figure 14 is a view similar two the preceding Figure, but with the distributor in the closed position; and Figure 15 is a similar view to that shown in Figure 8, with the distributor valve fitted.

In the embodiment illustrated in the drawings the tap body 1 has formed in it a gas inlet aperture 9, which very near its blind end 7 intersects a through aperture. This through aperture has various zones of different diameters. These zones are as follows: a zone 2 having the smallest diameter which constitutes the gas outlet to the burner; a zone 3 having a medium diameter which serves to support a distributor 19; and a zone 4 having the largest diameter which contains an elastic band 12. The zone 4 is followed by the cap 24 (Figure 12) on which the distributor 19 is also supported and which in turn is held by a casing 25 fastened to the body 1 by means of screws.This casing 25 has an aperture which serves to support the control rod 28, by which the distributor 19 is turned with the aid of the recess 21 (Figure 11) receiving the pin 27 when the rod 28 is pushed against the action of the spring 26. This turning movement provides the different positions of the distributor 19 corresponding to the closed position or to the different burner consumption positions.

The band 12 is provided with two diameterically opposite projections 13 and 14, a first one (13) of which is blind, while the second one (14) is open, both projections fitting perfectly into the inlet aperture 9, but with the open projection 14 on the gas admission side and the closed projection 13 at the blind end 7, in such a manner that this band 12, which is held compressed between the distributor 19 and the tap 1, will not be moved by the rotation of the distributor 19.

This band 12 has on the inside perimeter of its sides respective semitoric ribs 15, which are the portions of the band which are compressed and which act as O-rings to prevent the leakage of gas through the gaps, while at the same time reducing the area bearing on the distributor 19 and thus reducing the driving forcethatthe latter can exert.

In addition, the band 12 has other likewise semitoric but longitudinal ribs 16 which border an inlet 18 and the minimum passage 17, for the purpose of sealing these two parts from one another.

The distributor 19, which is cylindrical, has in turn two chambers 20 and 23, the first one (20) of which receives the rod 28, while the other one (23) coincides with the gas outlet constituted by the zone 2. This chamber 23 has a side mouth 22 which, as it turns (Figure 14), may be in alignment with the inlet 18 nor with the minimum passage 17 of the band 12, so that the gas passage will be closed, since the ribs 16 prevent the passage of gas arriving at the minimum passage 17 and the inlet 18 through the aperture 9. This mouth 22 can be in alignment with the inlet 18 which receives the full flow of gas, so that maximum consumption will be obtained, the two ribs 16 bordering the inlet 18 preventing the flow of gas from the other passage 17.In addition, when the mouth 22 of the distributor 19 is in alignment with the minimum passage 17, minimum consumption will be obtained, sealing being effected in the same manner (Figure 13).

Finally, when the mouth 22 is situated between the inlet 18 and the minimum passage 17, a series of consumptions between the maximum and minimum limits already explained will be obtained, depending on the degree of alignment with the inlet 18 or the passage 17, the nearest to the maximum being obtained, for example, with the closest alignment to the inlet 18.

Minimum gas consumption is now obtained in the minimum passage 17 in the following manner. A bore 5 is provided with zones of different diameters decreasing in the direction of the interior. This bore 5 has been made in a side of the foot of the body 1, at the side of the inlet aperture 9 and with a certain inclination towards the through gas outlet aperture and towards the outside, in such a manner that it slightly overlaps the inlet aperture 9 so as to form an access 10 for communication between them.

This bore 5 ends in another bore 6, which at its inner end intersects the through aperture on the body 1, thus forming a minimum access 8 situated in the segment formed by the turning of the mouth 22 of the distributor 19, in such a manner that they can come into alignment in the manner previously explained. At its open end this bore 6 is closed by a ball 29, which is inserted under pressure in such a manner that gas cannot escape.

A regulating valve 30 in the form of a needle valve, which incorporates an O-ring 31 to prevent leakages through the gaps in the screwthread, is screwed into the first bore 5. This needle valve 30 has a frustoconical tip seated perfectly in the end zone of smaller diameter of the bore 5, in such a manner that gas cannot pass therethrough. Likewise at the tip, the needle valve 30 has an axial perforation 33 in communication with a radial perforation 32, which always remains in the zone of the bore 5 where the access 10 is situated, and which has a larger diameter than the corresponding part of the needle valve 30, in such a manner that the gas passes through the perforations 32 and 33 even when the perforation 32 does not face the access 10.

Accordingly, when the needle valve 30 is screwed right home there will be a flow of gas only through the performations 32 and 33. However, if it is not screwed right home, the gas will also pass through the gas remaining between the needle 30 and its seat, thus permitting regulation of the minimum obtained in dependence on the type of gas to be used.

Consequently, the gas passes from a manifold to the aperture 9 in the body, thus reaching the inlet 18 and the access 10 and arriving in the amount permitted by the needle 30 at the bore 6 and consequently at the minimum access 8, passing or not passing through the mouth 22 to the outlet 2 of the body 1 in the desired amount, which depends on whether said mouth 22 is not in alignment with either of the accesses 17 and 18 or is in alignment with one or the other of them or with both at the same time, as has been explained previously.

Claims (4)

1. A tap for gas burners in cookers and the like appliances, including: a body having a foot provided with means for fastening itto a gas manifold; a gas inlet aperture formed in said body; a through outlet aperture also formed in said body, the inlet aperture intersecting at right angles with the outlet aperture; a rotary cylindrical distributor in said body and having a front chamber coinciding with the outlet aperture and having a side mouth on said chamber; control and retaining elements incorporated within the body; a bore provided in said body; a minimum regulating needle valve screwed into said bore, which bore near the zone where the tip of the needle is located is intersected by the inlet aperture, ending in a middle zone of another bore whose inlet mouth is preferably closed by means of a bail inserted under pressure and which in turn is intersected at its end by the through aperture of the tap in the zone of said aperture where the side mouth of the distributor is situated, thus forming a minimum access separate from the main admission of the gas to the tap; and a band of elastic material covering the distributor, said band being fixed to the body and having a gas inlet and a minimum passage facing the corresponding elements of the tap, said band being the element which provides a seal for the tap both in relation to gas leaks and in relation to the various closure positions and different flows, all of these being obtainable respectively either because the side mouth of the distributor is not in alignment with any of the passages in the body or because it is in alignmentwiththe main inlet or with the minimum access or with both at the same time.

2. A tap for gas burners according to Claim 1, wherein the band, which is located in a zone where the tap has an appropriate diameter, has two diametrically opposite cylindrical protuberances, one closed and the other open, the open protuberance fitting into the main aperture for admission of gas to the tap and the closed protuberance fitting into a blind end of the aperture formed by intersection with said through aperture.

3. A tap for gas burners according to claim 2, wherein on the one hand the band has internally, on the perimeter of its two ends, respective semitoric ribs which are compressed between the distributor and the tap body, thus sealing any gaps which may exist, and on the other hand has at least three compressed longitudinal ribs of the same shape, which extend from one end to the other and which border the gas inlet and the minimum passage, sealing the flow of gas in relation to the respective consumptions.

4. Atap for gas burners in cookers and the like appliances, constructed substantially as herein described with reference to and as illustrated in the accompanying drawings.