GB2159249A

GB2159249A - Gas valve

Info

Publication number: GB2159249A
Application number: GB08512786A
Authority: GB
Inventors: Fuentetaja Julio Bouzas
Original assignee: Individual
Current assignee: Individual
Priority date: 1984-05-24
Filing date: 1985-05-21
Publication date: 1985-11-27
Also published as: GB8512786D0; FR2582377A1; ES279457Y; ES279457U; FI851940A0; BE902491A; PT80520A; FI851940L; SE8502557D0; LU85911A1; DK223785A; SE8502557L; IT8520851A0; NO852067L; GR851265B; DE3518430A1; IT1200489B; NL8501454A; DK223785D0

Abstract

A shut-off valve for the automatic closure of a gas supply comprises a body (1) having an angled passage therethrough, a first sector of the said passage, corresponding to the gas inlet, having a valve head or obturator (5) which is urged towards an associated seat (7) by a spring (4), the valve head (5) carrying, on the opposite side of the valve to the said spring, a stem (8) which passes in a leak-proof manner through the valve body and accommodates at its free end an actuator (13), a peripheral groove or channel (11) of dihedral cross- section being formed in the said stem (8) in the vicinity of the actuator (13), a locking pin (20) interacting with the said groove (11), this pin (20) being actuated by the moveable core (18) of an electromagnet (15) and engaging at right angles on the said stem (8), the arrangement being such that the valve is opened by depressing the actuator (13) whereupon the electrical supply to the electromagnet (15) is connected thereby actuating the locking pin (20) to engage in the said groove (11) in the stem, and furthermore the electromagnet (15) being connected to an atmospheric analyser which, on detecting the presence of gas in the atmosphere, interrupts the electrical supply to the electromagnet (15) whereupon the locking pin (20) releases the stem (8) and the valve head (5) is returned to its closed position by the said spring (4). <IMAGE>

Description

SPECIFICATION Gas valve The present invention relates to a shut-off valve for gas installations.

As is known, accumulations of gas can occur in gas installations, sometimes due to damage in the circuit itself and sometimes due to currents of air which extinguish gas burners. This gives rise to a grave risk of explosion.

The present invention provides a gas shutoff valve which has been specially designed to function in combination with an atmospheric "analyser", in a manner such that when the latter detects the presence of gas in the atmosphere, for the reasons stated above or any other reason, it triggers an automatic closing down of the supply of the said gas.

In addition the valve of the invention is also designed to be capable of shutting down the supply of gas when, for whatever reason, excess pressure occurs which could give rise to the arrival at the burners of an excessive quantity of gas which could cause problems of various kinds.

According to the present invention, there is provided a shut-off valve for the automatic closure of a gas supply comprising a body having an angled passage therethrough, a first sector of the said passage, corresponding to the gas inlet, having a valve head or obturator which is urged towards an associated seat by a spring, the valve head carrying, on the opposite side of the valve to the said spring, a stem which passes in a leak-proof manner through the valve body and accommodates at its free end an acutator, a peripheral groove or channel of dihedral cross-section being formed in the said stem in the vicinity of the actuator, a locking pin interacting with the said groove, this pin being actuated by the moveable core of an electromagnet and engaging at right angles on the said stem, the arrangement being such that the valve is opened by depressing the actuator whereupon the electrical supply to the electromagnet is connected thereby actuating the locking pin to engage in the said groove in the stem, and furthermore the electromagnet being connected to an atmospheric analyser which, on detecting the presence of gas in the atmosphere, interrupts the electrical supply to the electromagnet whereupon the locking pin releases the stem and the valve head is returned to its closed position by the said spring.

The valve proposed by the invention is formed from a body having an angled passage for the gas, and the first section of the said passage being provided with a valve seat for a valve head or obturator, which is at all times urged into a closed position, owing to the actual pressure of the gas and with the aid of a spring.

From the said valve head there emerges a stem which passes through the valve body in the same longitudinal direction as the first section of the angled passage, the stem being accompanied in this zone by a gasket and being associated with an actuating button, the stem possessing on its periphery and in the vicinity of the said button a peripheral groove of dihedral cross-section into which fits a locking pin, associated with the stem of an electromagnet, in a manner such that as the button is actuated in order to open the valve the supply circuit to the electromagnet is closed and the latter, via the said pin, causes the locking of the stem, or, which is the same thing, of the valve head, in the open position of the latter.

This position is maintained indefinitely provided that no manual actuation in the opposite direction is exerted on the button, or that the supply to the electromagnet is not interrupted, this supply being controlled by the said atmospheric analyser, which is to say that when the said analyser detects the presence of gas in the atmosphere it causes the instantaneous interruption of the circuit supplying the coil of the electromagnet, and, consequently, the stem is freed from its locked condition and the pressure exerted on the valve head by the gas itself and by the spring which assists it likewise cause the instantaneous closing of the valve.

This closed position can also be triggered by excess gas pressure, for which purpose the gauge of the spring which assists the valve head is chosen so that, when the pressure on the valve head increases above a preset value, the said excess pressure causes disconnection between the pin and the groove in the stem, with consequent closing of the valve.

An embodiment of the present invention will now be illustrated, by way of example only, with reference to the accompanying drawings, in which: Figure 1 shows a side elevation, in section of a shut-off valve for automatic interruption of a gas supply in the event of gas escapes, constructed in accordance with the present invention, the said valve being shown in the closed position; Figure 2 shows a view of the valve of Fig.

1, but in the open position; Figure 3 shows an enlarged detail of the connection between the stem associated with the valve head and the pin associated with the moveable core of the electromagnet; and Figure 4 shows, a view of the valve from below, wherein there can be seen the washer which acts as a seat for the spring which interacts with the valve head.

Referring to the drawings, a shut-off valve proposed by the invention is formed from a body 1 having an angled passage for gas. A toothed washer 2 is fixed by means of a circlip 3 in a first section of the said passage.

A spring 4 is held in position by the washer 2 and, duly gauged, acts on the valve head or obturator 5, tending to urge it (and its associated gasket 6) against the frustum-shaped seat 7 in the body 1.

Beyond valve head 5, on the opposite face to that where the spring 4 is located, extends a stem 8 which projects beyond the angle in the gas passage and passes through the body 1 of the valve through an aperture 9 formed in the latter.

The stem 8 is hermetically sealed with respect to the passage aperture 9 by a ring gasket 10 accommodated in a peripheral groove on the stem, the said stem acting as a fixing and control element for the valve head and also as a guide element for the latter.

The stem 8 is provided, in the vicinity of its free end, with another peripheral groove 11, which is of dihedral cross-section. The outer free end of the stem 8 carries an actuating button 13, secured thereto by means of a screw 12.

In correspondence with this end sector of the body 1, wherein the actuating button 1 3 is fitted, and with the outlet 14 for the gas, there is fitted an electromagnet 15, duly fixed to the valve body 1 via a support 16, in a manner such that the coil 1 5 of the said electromagnet defines a cylindrical housing 17 for the sliding fit, of the piston 18. A locking pin 20 having a dihedral head corresponding to the groove 11 on the stem 8 is attached to the piston 18 by a rod 1 9.

According to the design which has been described, the mode of operation of the valve is as follows.

From the closed position shown in Fig. 1, the stem 8 is displaced axially, pressing on the button 13, as far as the limiting position shown in Fig. 2, in which the supply circuit of the electromagnet 15 is closed, its piston 1 8 impels the locking pin 20 towards the stem 8 and causes it to lodge in the dihedral groove 11, the valve head thus adopting the open position shown in Fig. 2, in opposition to the actual pressure of the gas and especially to the tension of the spring 4.

When the atmospheric analyser, which is not shown in the drawings and is supplementary to the proposed valve, sends the appropriate signal, on detecting gas in the atmosphere, the circuit supplying the electromagnet 1 5 is interrupted, whereupon the dihedral nature of the connection 11-20 causes the force component applied to the stem by the spring 4 to produce the retraction of the said pin 20, and the stem 8 remains free for the valve head 5 to move towards the closed position shown in Fig. 1.

It may attain this position in the case of an excess gas pressure, since in this event the pressure applied to the valve head 5 in the open position of Fig. 2 will be greater than that which is normally applied by the spring 4 and the exiting gas, so that the pin 20 will not be able to maintain the locking position and unlocking of the stem 8 will take place, with consequent closing of the valve.

Although, in the examplary embodiment shown in the drawings, the gas outlet 14 and the inlet 21 appear to be threaded internally, it is clear that such valve connections may be of any other conventional type, as for example based on flanges, welding sleeves, and the like, the type of material involved in the design of the assembly likewise being variable, as for example brass, bronze, stainless steel, plastic, and the like.

From the construction described, it can be inferred that the valve will also pass automatically into the closed position in the event of a cut in the supply of electrical current, in which case resetting is easily achieved merely by exercising light pressure on the actuating button 1 3 of the valve.

To this effect, and in the event of excessively prolonged cuts in the supply of electricity, the valve can be locked in the open position, in a mechanical manner, with the reservation that in this case the safety character of the valve is cancelled, so that the user will have to depend on the restoration of the supply of electricity to override the manual locking.

The materials, shape, size and arrangement of the components can be varied, provided that this does not entail a modification to the essential substance of the invention.

It will be seen that the structural characteristics of the said valve have been specially designed to achieve automatic interruption or shutting-off of the supply from the said valve in the event of a possible escape of gas.

Claims

1. A shut-off valve for the automatic closure of a gas supply comprising a body having an angled passage therethrough, a first sector of the said passage, corresponding to the gas inlet, having a valve head or obturator which is urged towards an associated seat by a spring, the valve head carrying, on the opposite side of the valve to the said spring, a stem which passes in a leak-proof manner through the valve body and accommodates at its free end an actuator, a peripheral groove or channel of dihedral cross-section being formed in the said stem in the vicinity of the actuator, a locking pin interacting with the said groove, this pin being actuated by the moveable core of an electromagnet and engaging at right angles on the said stem, the arrangement being such that the valve is opened by depressing the actuator whereupon the electrical supply to the electromagnet is connected thereby actuating the locking pin to engage in the said groove in the stem, and furthermore the electromagnet being connected to an atmospheric analyser which, on detecting the presence of gas in the atmosphere, interrupts the electrical supply to the electromagnet whereupon the locking pin releases the stem and the valve head is returned to its closed position by the said spring.

2. A shut-off valve according to Claim 1, wherein the coil of the electromagnet is fixed to the valve body with the aid of a support which is provided with an aperture for the passage of a rod which links the moveable core with the locking pin, this latter moving in another aperture in the body, perpendicular to the housing or stem aperture.

3. A shut-off valve according to Claim 1 or 2, wherein the spring which impels the valve head towards its corresponding seat rests on a toothed washer which is located in the gas inlet passage by means of a circlip.

4. A shut-off valve according to Claim 1, 2 or 3, wherein that said spring is gauge so as to exert, jointly with the gas pressure, a predetermined tension to the stem, close to the limit at which the latter can be retained by the locking pin, when the coil is excited, all this in order that an excess gas pressure causes the unlocking of the stem and the corresponding closing of the valve.

5. A shut-off valve according to any one of the preceding claims, wherein the actuating button is provided with means for manual locking of the valve so as to permit the valve to be kept open in the even of a cut in the supply of electrical energy.

6. A shut-off valve for the automatic closure of a gas supply substantially as hereinbefore described with reference to the accompanying drawings.