GB2267335A

GB2267335A - A multifuctional valve with a thermoelectric safety feature for the gas burners of heating appliances in general

Info

Publication number: GB2267335A
Application number: GB9309796A
Authority: GB
Inventors: Gianpiero Turrin; Roberto Mozzato
Original assignee: Sit La Precisa SpA
Current assignee: Sit La Precisa SpA
Priority date: 1992-05-26
Filing date: 1993-05-12
Publication date: 1993-12-01
Anticipated expiration: 2013-05-12
Also published as: GB9309796D0; FR2691787A1; ITMI921288A1; DE9307895U1; ITMI921288A0; FR2691787B1; IT1255275B; GB2267335B; NL9300869A

Abstract

A multifunctional valve in which the push-button controls (20, 22) for ignition and extinguishing a burner (4) act on switches (19, 21) provided in the energising circuits of the gas-inlet solenoid valve (8) and the thermocouple circuit (17) respectively. Gas entering inlet (2) supplies gas to pilot light (13) and the main burner (4). During ignition, button (20) is pressed so that switch (19) is in the dotted position. This operates solenoid (8) and allows gas to pass to the pilot light. Also the igniter is operated via ignition device (16). When the pilot light is lit, thermocouple (17) activates magnet assembly (18) to keep obturator (6) open. Release of button (20) moves switch (19) so that solenoid (12) is operated so that gas can pass to burner (4). Pressing button (21) deactivates magnet (18) so that obturator (6) closes gas to the pilot light and the burner. <IMAGE>

Description

A MULTIFUNCTIONAL VALVE WITH A THERMOELECTRIC SAFETY FEATURE FOR THE GAS BURNERS OF HEATING APPLIANCES IN GENERAL The present invention relates to a multifunctional valve having a thermoelectric safety feature, used to advantage in gas-supply circuits for the burners of heating appliances in general and for the boilers of domestic central heating systems in particular.

This valve is bf the type which includes a valve body in which there is formed a path for the gas which extends from a gas inlet aperture to an outlet aperture for the supply of the gas to a burner, an outlet aperture for the supply of gas to a pilot light, which is formed in the valve body between the valve seats, first and second valve seats with which cooperate respective obturators to cut off the gas flow entering the valve body and leaving it respectively, and a magnet assembly acting on the obturator of the first valve seat against spring means and electrically connected to a thermocouple.

It is known that the manual controls for the ignition and extinguishing of the pilot light (or pilot burner) are, in general, associated physically with the body of the multifunctional valve; in fact a control acting directly or indirectly on one or more actuators of the gas inlet valve is provided for the ignition and extinguishing of the pilot light. It is also known that the positioning of this multifunctional valve relative to the main burner of the boiler is constrained by technical reasons of design. As a result, this positioning, of necessity, does not take account of incidental requirements for the installation of the boiler in domestic situations, which vary case by case. For this reason, poor or even really awkward access to the ignition and extinction controls is among the disadvantages most frequently mentioned by users in connection with gas-fired boilers.

The main object of the present invention is to provide a multifunctional valve with a thermoelectric safety feature, of the type mentioned above, having structural and functional characteristics such that the ignition and extinguishing of the pilot light may be "remote" controlled, without thereby complicating either the construction or the operation of the boiler itself, or the installation of the boiler.

This object, and others that will become clearer from the description which follows, are met by a multifunctional valve, with a thermoelectric safety feature, of the type described above and incorporating the structural characteristics itemised in the appended claim 1.

The advantages and characteristics of a multifunctional valve with remote control according to the invention will become clearer from the following description of one embodiment with reference to the appended drawing, supplied purely by way of non-limitative example, in which the valve and its electrical connections are shown schematically.

With reference to the drawing, a multifunctional valve with a thermoelectric safety feature according to the invention includes a valve body 1 defining a path for a gas flow which extends from a gas-inlet aperture 2 to an outlet aperture 3 for supplying the gas to a main burner 4. A first valve seat 5 is formed in the gas path and cooperates with an obturator 6 operated by a first solenoid valve, generally indicated 8, opposed by spring means 7, to cut off the gas flow into the valve body 1.

A second valve seat 9 is formed near the gas-outlet aperture 3. An obturator 10 cooperates with this valve seat 9 and is operated by a respective solenoid valve generally indicated 12 and opposed by spring means 11.

A pilot light, generally indicated 13, is in fluid communication with the interior of the valve body 1 through a duct 14 and a gas supply aperture la formed in a position between the seats 5 and 9 in the said body.

An electrode 15 for lighting the pilot light is electrically connected to an ignition device 16, while a thermocouple 17 is electrically connected to a magnet assemby 18 arranged in the valve body 1 and acting on the obturator 6 through an armature 6a fixed to the obturator to cut off the gas flow into the valve body 1.

The mains electrical supply available in the location where a boiler incorporating the multifunctional valve described above is to be installed is schematically indicated A. The solenoid valves 8 and 12, and also the ignition device 16, are electrically connected to the mains A through a switch 19 controlled by a push-button 20.

The thermocouple circuit, including the thermocouple 17 and the magnet 18a of the magnet assembly 18, is also connected to the mains A through a two-way switch 21 controlled by a push-button 22.

The push-buttons 20 and 22 with their respective switch 19 and two-way switch 21 and an appropriate terminal board (not shown) are grouped together to advantage in a single unit, for example a control panel indicated in broken outline at 23, that is structurally independent of the valve body 1.

The operation is as follows: To light the boiler1 the push-button 20 is pressed to switch the switch 19 into the position indicated by a broken line, where it is kept for a few seconds. By this action, the solenoid valve 8 is supplied from the mains while the solenoid valve 12 is not supplied. In this condition, the solenoid valve 8 acts on its obturator 6, moving it into the position opening the respective valve seat 5, while the spring 11 keeps the obturator 10 in its position closing the valve seat 9. The gas flows into the valve body 1 and, from here, towards the pilot light 13 only.

The ignition device 16 is supplied at the same time as the solenoid valve 8 and ignites the pilot light by means of the electrode 15. The flame is detected by the thermocouple 17 which, as a result, keeps the magnet assembly 18 energised so that the magnet 18a retains the armature 6a and thus holds the obturator 6 in its open position. It should be noted that the support shaft of the obturator 6-armature 6a unit is constructed, to advantage, like a shock absorber so that it can absorb any overrun of the unit. In this way the armature 6a is prevented from knocking against the pole pieces of the magnet 18a, thereby ensuring its correct operation and long life.

On release of the push-button 20, the switch 19 returns to the position indicated by a solid line whereby the solenoid valve 8 and the ignition device 16 are deenergised while the solenoid valve 12 is energised.

In this condition, the obturator 10 is moved into a position opening its valve seat while the obturator 6 is held open by the magnet assembly 18. The gas is thus able to flow to the main burner 4.

To switch off the boiler, the push-button 22 is pressed so that its two-way switch 21 moves into its closed position (indicated by a broken like). A signal is thus sent through the thermocouple circuit cancelling for an instant the magnetic flux generated in the assembly 18 by the thermocoupl#l7. In that instant, the action of the spring means 7 prevails on the obturator 6 with the result that the obturator itself is moved into its position closing the valve seat 5 thereby positively cutting off the gas flow entering the valve body 1.

The invention as conceived may be altered and modified without departing from the scope of the inventive concept. For example, to switch off the boiler the magnetic flux generated in the magnet assembly 18 by the thermocouple 17 is interrupted (for an instant). This interruption may be achieved by providing a switch directly in the thermocouple circuit, controlled by a respective push-button.

The advantages offered by the present invention basically include the possibility of operating the multifunctional valve by remote control to light or switch off the boiler; ease of installation as the push-buttons may be made readily accessible whatever the position of the valve and, last but not least, the ease with which manual ignition may be replaced by automatic ignition; to this end it is easy to provide a timer to operate the pushbutton 20 at a signal from a thermostat.

Claims

1. A multifunctional valve, with a thermoelectric safety feature, for the gas burners of domestic centralheating systems including a valve body (1) in which there is formed a path for the gas which extends from a gasinlet aperture (2) to an outlet aperture (3) for the supply of gas to a burner (4), first and second valve seats (5, 9) with which cooperate respective obturators (6, 10) to cut off the gas flow entering the valve body (1) and leaving it respectively; the obturators (6, 10) being operated by corresponding solenoid valves (8, 12) and opposed by respective spring means (7, 11), an aperture (la) formed in the valve body (1) between the seats (5, 9) for supplying gas to a pilot light (13), a magnet assembly (18), acting on the obturator (6) of the first valve seat (5) against the spring means (7) thereof and connected electrically to a thermocouple (17), the solenoid valves (8, 12) being connectible alternately to the mains electricity supply (A) through a switch (19), the thermocouple circuit, which includes the thermocouple (17) and the magnet assembly (18), being electrically connected to the mains electricity supply (A) through a manually-operable two-way switch (21).

2. A multifunctional valve according to Claim 1, characterised in that the switch (19) and the two-way switch (21) are operated manually by means of respective push-buttons (20 and 21).

3. A multifunctional valve according to Claim 2, characterised in that the push-buttons (20, 22) and their associated switch (19) and two-way switch (21) are grouped together in a control panel (23) which is structurally independent of the valve body (1).

4. A multifunctional valve according to Claim 3, characterised in that the control panel includes a terminal board for its connection to the electrically controlled components (8, 12, 15, 17, 18) associated with the valve body (1).

5. A multifunctional valve including a valve body (1) in which there is formed a path for the gas extending from a gas-inlet aperture (3) to an outlet aperture (3) for the supply of gas to a burner (4), first and second valve seats (5, 9) with which cooperate respective obturators (6, 10) to cut off the gas flow entering the valve body (1) and leaving it respectively, the obturators (6, 10) being operated by corresponding solenoid valves (8, 12) opposed by respective spring means (7, 11), an aperture (la) formed in the valve body (1) between the seats (5, 9) for supplying gas to a pilot light (13), a magnet assembly (18) acting on the obturator (6) of the first valve seat (5) against its spring means (7) and connected electrically to a thermocouple (17), the solenoid valves (8, 12) being connectible alternately to the mains electricity supply (A) through a switch (19), and the thermocouple circuit (17), which includes the thermocouple (17) and the magnet assembly (18), being provided with a switch operable by a respective manual control to interrupt the magnetic flux generated by the thermocouple.

6. A multifunctional valve substantially as hereinbefore described with reference to and as shown in the appended drawing.