GB2178519A

GB2178519A - Improvements relating to gas-fired appliances

Info

Publication number: GB2178519A
Application number: GB08516811A
Authority: GB
Inventors: Benjamin Frank Gostelow
Original assignee: TI New World Ltd
Current assignee: TI New World Ltd
Priority date: 1985-07-03
Filing date: 1985-07-03
Publication date: 1987-02-11
Also published as: GB2178519B; GB8516811D0

Abstract

A gas cooker or hob has a lid which, in its closed position, covers the top burners of the cooker/hob. To ensure that the fuel supply to the top burners is cut off when the lid is closed but that the fuel supply to other burners, e.g. oven burners, is maintained, a gas supply rail (1) which is divided into two parts by a flow control valve (17) is provided. One of the two parts of the gas rail is in direct communication with the fuel inlet (2a) of the rail and the burners other than the top burners are supplied with fuel from this part of the rail. The top burners are supplied with fuel from the second part of the rail, and this part communicates with the fuel inlet of the rail only via the flow control valve. The valve is connected to the lid of the cooker/hob to cut-off the flow of fuel into the second part of the rail when the lid is closed. <IMAGE>

Description

SPECIFICATION Improvements in and relating to components for gas-fired appliances This invention relates to components for gasfired appliances and to gas fired appliances.

In many forms of gas-fired appliances, for example, gas cookers and hobs, top burners are fed with gaseous fuel via a gas rail which also supplies such fuel to other burners, for example oven and grill burners. In those cases in which the gas cooker or hob is provided with a lid or cover which, in its closed position covers the top burners, it is important that fuel supply to the top burners is cut off before the lid or cover reaches its closed position.

It has been proposed to provide a cut-off valve in the fuel supply line to the gas rail and to link operation of the valve to movement of the lid or cover in a manner such that during closing movement of the lid or cover, the cutoff valve is operated to prevent fuel supply to the gas rail and that during opening movement of the lid or cover, the valve is operated to allow such supply. However, it is also necessary to ensure fuel supply to the other burners regardless of the position of the lid or cover.

previous proposals to permit this have been complicated and costly.

According to one aspect of the present invention, a gaseous fuel supply passageway is divided into two parts by a fuel flow control valve and having a plurality of fuel outlets at least one of which is in one of the parts, the remainder being in the other part, the passageway having a gaseous fuel inlet in direct communication with one part only of the rail and with the other part via the fuel flow control valve.

The invention also envisages a gas rail having a gaseous fuel supply passageway divided into two parts by a first fuel flow control valve and having a gaseous fuel inlet in direct communication with one part only of the rail and with the other part via the first flow control valve.

Furthermore, the invention also provides a gas rail having a gaseous fuel supply passageway, the passageway being divided into two parts by a first fuel flow control valve operable to control fuel flow from one part to the other part, a series of gaseous fuel outlets, at least one of which is in one of the parts and the remainder in the other part, a series of further gaseous fuel flow control valves each of which controls fuel flow from the respective part of the passageway to one of the outlets, the passageway also having a gaseous fuel inlet in direct communication with the one part and via the first flow control valve with the other part.

The passageway or the gas rail may be of one-piece construction.

The inlet may be located at one end of the passageway or rail, the other end of which is closed.

Alternatively, the passageway may be closed at both ends, the inlet being located at a site along the length of the one part.

The first flow control member may comprise a flow control member adapted to enter the passageway to terminate the supply of gaseous fuel from the one part to the other part.

The flow control member may be resiliently biassed into a position in which it is clear of the passageway.

The gas rail may be contoured to provide areas each of which co-operates with a moving part of one of the series of further flow control valves to control fuel flow from the passageway.

Each area may also form a part of the housing of the further flow control valve.

The invention also envisages a gas appliance having one or more top burners, a lid movable between an open position giving access to the or each top burner, and a gas rail as referred to above, the lid being operatively connected to the first flow control valve in a manner such that the latter prevents fuel flow from the one part to the other part when the lid is in its closed position and permits such flow when the lid is in its open position.

The invention also provides a gas hob having one or more gas burners supplied with gaseous fuel via one or more gas flow control valves mounted upon a gas rail, with an internal fuel supply passageway, the supply of fuel to the passageway being controlled by a first fuel flow control valve having a flow control member of a resilient material adapted to enter the passageway to close the latter to prevent the supply of fuel to the control valves.

The flow control member of the gas hob may be resiliently biassed into a position in which it is clear of the passageway.

The gas hob may have a lid movable between an open position giving access to the burner or burners and a closed position in which the lid covers the burner or burners, and in which the lid is operatively connected to first flow control valve in a manner such that the latter is operated to prevent fuel flow into the passageway when the lid is in its closed position and to permit such flow when the lid is in its open position.

The closing weight of the lid may be counterbalanced, at least partially, the operative connection to the first control valve being effected via the counterbalance.

Warning means may be included, such means being operable on movement of the lid into its closed position unless the or each top burner is "OFF".

Alternatively, the warning means may be operable on movement of the lid into its open position unless the or each top burner is "OFF".

Latching means may be provided for retaining the first control valve operated once operation on lid movement from open to closed position has taken place.

The latching means may be releasable to allow the first control valve to return to a non-operated condition only when all the top burners are "OFF".

Alternatively, the latching means may be releasable manually.

The invention also comprisess a fluid flow control valve assembly comprising a passage having an inlet and an outlet, and a control valve with a flow control head of a resilient material, the head being adapted, in the closed position of the control valve, to enter and close the passage.

The flow control head may be resiliently biassed into a position in which it is clear of the passage.

By way of example only, a gas rail and a gas flow control valve assembly embodying the invention will now be described in greater detail with reference to the accompanying drawings of which: Fig. 1 is a plan view partly in section of the gas rail, Fig. 2 is a section on the line ll-ll of Fig. 1, Fig. 3 is a front elevation of the gas rail, Fig. 4 is a vertical section of the fuel flow control valve assembly, Fig. 5 is a plan view of the assembly, and Fig. 6 is a diagrammatic side view partly in section of the upper part only of a gas cooker.

Referring first to Figs. 1, 2 and 3, there is shown a gas rail 1 which is an extruded length of aluminium or light alloy of generally rectangular cross-section in a plane transverse to the length of the rail. The rail is formed with a through passageway 2 located adjacent one of the shorter sides of the rail. The passageway 2 is closed at one end by a plug 3 whilst the other end is open and forms a gas supply inlet 2a.

The upper (as seen in Fig. 1) face of the rail is machined to provide mating areas for the housings and moving parts of gas flow control taps 4-9 details of which are given below.

Taps 4-7 control gas flow from the passageway 2 to individual injectors 10...13 respectively which supply gas to top burners of a gas cooker (not shown).

Tap 8 controls gas flow from passageway 2 to an outlet 14 connected to a grill burner (not shown). Tap 9 in association with a thermostatically controlled valve within a housing 15 secured to the undersurface of the rail controls gas flow from the passageway 2 to an outlet indicated at 16 that is joined to an oven burner (not shown).

The passageway 2 is, in effect, divided into two parts by a gas cut-off valve 17 forming part of an assembly 18 secured to a side face of the rail between taps 7 and 8. When in its closed position, the valve prevents gas flow from the inlet of the gas rail along the passageway 2 to the taps 10...13 but does not prevent gas flow to the taps 8 and 9.

The valve assembly 18 is shown in more detail in Figs. 4 and 5. 8ecured to the side of the rail 1 by screws 19 and 20 is a cap 21 comprising legs 22 interconnected by an integral bridge 23 apertured centrally as at 24 to give access to a spindle 25 which passes into the rail 1 through a passage 26. The passage 26 communicates at its inner end with the passageway 2 in the gas rail 1. The spindle 25 has an external shoulder 27 formed between its ends and which provides a seating surface for a spring 28 that is accommodated in a deep annular recess 29 surrounding the passage 26. As can be seen from Fig. 4, the recess 29 does not extend into the gas rail 1 as far as the passageway 2.

The lower (as seen in Fig. 4) end of the spindle 25 carries a valve head 30 of a resilient material that will not acquire a permanent "set" during use. The valve head 30 may be of a silicon rubber or other suitable plastics material. The valve head 30 is sized to fit tightly into the passageway 2 and to extend for a very short distance into passage 26. In that way, the passageway 2 is sealed in an effective gas-tight fashion when the valve head is in the closed position shown in Fig. 4.

Leakage along the spindle is prevented by an '0' ring seal 31 carried by the spindle.

Spring 28 is under compression when the valve head is in the closed position shown in Fig. 4 and is of sufficient strength to move the spindle upwardly against the frictional resistance of the head 30 on the passageway 2 (as viewed in Fig. 4) when closing pressure on the spindle is removed.

Fig. 1 shows the valve head 30 in its open position.

When closed, the valve head 30 isolates that part of the passageway 2 to the left of the head as viewed in Fig. 1 and thereby cuts off that part from the gas inlet It will be ap preciated that the gas rail construction just described is of relatively simple and economic form and provides control over the fuel supply to the top burners in a manner that is also relatively simple and economic.

Where the rail is incorporated into a hob or cooker with a lid that can be lowered to con ceal the top burners of the hob or cooker when not in use, the spindle 25 is linked to the lid and is operated by movement of the latter. As the lid moves into its closed position, spindle 25 is moved downwardly (as viewed in Fig. 4) thereby moving the valve head 30 into the closed position shown in Fig.

4 and effectively preventing the supply of gas ko the taps 4...7 and thus to the top burners.

In that way, possible damage to the lid by the flame of a top burner inadvertently left on when a user closed the lid is avoided. Further more, gas will not pass to any of the top burners whilst the lid is in its closed position.

Any suitable linkage may be used to couple the spindle 25 and the lid and an example of one such linkage is shown in Fig. 6.

Fig. 6 shows in diagrammatic form only the upper part of a gas cooker generally of conventional form and including a body with rear vertical members 32 at each side of the upper part of the body. The members 32 carry hinge pins 33 as shown and by means of which a lid 34 is pivotally mounted. The lid 34 is movable between the closed position shown in Fig. 6 and an open position in which the lid is vertical or substantially so.

On the top of the cooker is a series of top burners (not shown) below which is supported a spillage tray 35. Seated upon the spillage tray 35 is a pan support, fingers of which are shown at 36. The fingers are welded or otherwise secured to a frame, part of which is shown at 37.

Located beneath the spillage tray 35 are gaseous fuel feed tubes part of one of which is shown at 52 and which supply a mixture of gas and air to top burners located above the spillage tray 35 which has raised spaced areas 38 on which the burners rest.

The feed tubes extend from the burners to the injectors 10...13 of the taps 4...7 respectively and terminate in venturi which co-operate with the injectors in the well known manner.

The gas rail 1 and taps are indicated schematically in Fig. 6. The rail 1 extends across the front of the cooker being supported upon suitable surfaces at each end of its length, one of such surfaces being indicated at 53.

As can be seen from Fig. 6, the rail 1 is seated upon one of its shorter sides, the spindles 54 of the gas taps on the rail extending horizontally through a control panel 55.

Externally of the panel 55, the spindles 54 carry control knobs 56.

The injectors 10...13 extend upwardly from the upper side of the gas rail and are angled as at 57 to align with the mouths of the respective gaseous fuel passageways for example that shown at 52.

Opening and shutting of the valve head 30 is effected by the pivotal movement of the lid 34. The valve head is moved to its closed position as the lid moves into its closed position and the valve head is in the closed position before the lid reaches its closed position.

The spindle 25 is connected to a control rod 39 that extends rearwardly beneath the spillage tray 34 and is linked, at its rearward end, to a rod 40 pivotally joined at one end via a socket 41 to a hinge block 42 by means of which the lid 34 is pivotally mounted. The point of connection of the socket 41 to the hinge block 42 is spaced from the hinge pin 33 as can be seen from Fig. 6.

Rod 40 extends downwardly behind the cooker and carries, about midway of its ends, a bush 43 that is supported on the rod 40 by stops thereon. Located between the bush 43 and a further bush 44 is a helical spring 45 through which the rod 40 passes.

Bush 44 is loose on the rod 40 and is carried on an externally threaded tubular adjus tor 46 that fits round the rod 40 adjacent the lower end thereof. A collar 47 that is part of the adjustor 46 has holes 48 to receive the end of a tommy bar used to rotate the adjus tor 46 to vary the degree of initial compres sion of the spring 45 between the bush 43 and the adjustor 46.

The adjustor 46 screws through a mounting 49 having lateral extensions 50 of semi-circu lar shape when seen in end elevation as in Fig. 6. The extensions 50 seat upon sideways extending limbs integral with the adjacent member 32 and one of which is shown at 51.

When the lid 34 is in its closed position as shown in Fig. 6, the spring 45 is compressed between the bushes 43 and 44, the degree of compression being preset by means of the adjustor 46.

If a user now wishes to use one or more of the top burners, the lid 34 is lifted by means of a handle (not shown). The action of the spring 45 assists the opening movement of the lid providing a force which counterba lances to a desired extent the closing weight of the lid.

The adjustor 46 may be set to produce the counterbalance action described in U.K. patent Application No. 2,109,919A or it may be set to produce a counterbalance action in which the closing weight of the lid is fully counterba lanced during a closing movement except dur ing the initial stage thereof.

As the lid 34 moves into its open, vertical position, rod 40 pivots in a clockwise direc tion about the limbs 51 and the control rod 39 moves to the right as seen in Fig. 6 and valve head 30 is moved out of the passage way 2 so enabling gas to flow from the gas inlet to the inlets of the taps 4...7. Thus one or other of the top burners can now be brought into use.

When the user has finished with the top burners and decides to close the lid 34, a check is first made to ensure that all the taps 4...7 are in their "OFF" positions. The lid 34 can then be closed. During closure, the clos ing weight of the lid is counterbalanced to a required extent by the spring 45. Also, during closure of the lid, rod 40 pivots in an anti clockwise direction and the resultant move ment of the control rod 39 moves the valve head 30 back into its closed position.

If, inadvertently, the user omits to ensure that taps 4...7 are "OFF" before closing the lid, movement of the valve head 30 to its closed position during the closing movement of the lid will automatically terminate the sup ply of gaseous fuel to all top burners. How ever, on subsequent opening of the lid, gas supply will be resumed to such burners and the user must then either light the burner or burners or turn off the appropriate gas tap or taps. Alternatively, an automatically operating ignition device may be fitted which comes into use as the lid is opened and ignites gas emerging from any top burner inadvertently left on.

Warning lights may also be fitted in a conspicuous position, such lights being energised when any tap of a top burner is not in its "OFF" position. A user is thus advised if any such tap in in its "ON" position when the lid is closed.

Alternatively, a warning light or an audible warning may be energised in the event that a user attempts to close the lid with one or more of the top burners still operating. If desired, the warning may be energised when a user opens the lid, one or more of the top burners having previously been left "ON".

The valve assembly 18 may incorporate a latching mechanism such that the valve is latched in its closed position in the event that a user opens the lid without first ensuring that the taps of the top burner -are in the fully "OFF" position.

U.K. Patent Application No. 85.19513 describes a latching mechanism that may be used.

Alternatively, the latch may be resettable manually by the user to allow the valve to open and restore the supply of fuel. In the case of a hob, the resetting control is preferably accessible only when the hob lid is in its open position or nearly so. In the case of a gas cooker, the resetting control is preferably operable by a user only when the cooker lid is opened.

In another embodiment suitable for use as a gas hob, the valve assembly 18 is used to control the flow of fuel into a gas rail on which taps controlling the flow of fuel to the hob burners are mounted. Such a rail is not divided into two parts as described above and thus when the head 30 of the valve assembly is in its closed position in the first passageway of the gas rail, there is no gaseous fuel flow into the rail.

Preferably, the hob has a lid which may be counterbalanced and the lid may be operatively connected with the valve assembly 18 in a manner such that fuel supply to the rail is prevented when the lid is in its closed position and permitted when the lid is in its open position.

The valve assembly may incorporate a latching mechanism, for example of one or other of the forms described in U.K. Patent Application No. 85.19513.

Alternatively, the latch may be manually resettable by a user to allow fuel supply to the rail. The resetting control is so sited as to be accessible only when the lid is in its open position or nearly so.

It will be appreciated that supply of gas to taps 8 and 9 remains unaffected by movement of the lid so that a user can always bring into use the grill burner and/or oven burner regardless of the lid position.

It will also be understood that other forms of lid counterbalance mechanism may be used and that the valve head 30 may be linked for operation directly to the lid or component movable therewith other than a component of the counterbalance mechanism.

The gas taps referred to above may be of any suitable construction, the form shown in Figs. 1 and 2 is described in detail in U.K.

Patent Application No. 84.24905.

Furthermore, the valve in the gas rail may be of another form than that described above with reference to Fig. 4.

The valve shown in Fig. 4 may also be used in applications other than the gas rail embodiment described above.

Claims

1. A gaseous fuel supply passageway divided into two parts by a first fuel flow control valve and having a plurality of fuel outlets at least one of which is in one of the parts, the remainder being in the other part, the passageway also having a gaseous fuel inlet that is in direct communication with one part only of the passageway and with the other part thereof via the first fuel flow control valve.

2. A gas rail having a gaseous fuel supply passageway divided into two parts by a first fuel flow control valve and having a gaseous fuel inlet in direct communication with one part only of the rail and with the other part via the first flow control valve.

3. A gas rail having a gaseous fuel supply passageway, the passageway being divided into two parts by a first fuel flow control valve operable to control fuel flow from one part to the other part, a series of gaseous fuel outlets, at least one of which is in one of the part and the remainder in the other part, a series of further gaseous fuel flow control valves each of which controls fuel flow from the respective part of the passageway to one of the outlets, the passageway also having a gaseous fuel inlet in direct communication with the one part and via the first flow control valve with the other part.

4. A passageway as claimed in claim 1 or a gas rail as claimed in claim 2 or 3 in which the passageway or the rail is of one-piece construction.

5. A passageway as claimed in claim 1 or 4 or a gas rail as claimed in claim 2, 3 or 4 in which the inlet is located at one end of the passageway or rail, the other end of which is closed.

6. A passageway as claimed in claim 1, 4 or 5 or a gas rail as claimed in claim 2, 3, 4 or 5 in which the passageway or rail is closed at both ends, the inlet being located at a site along the length of the one part.

7. A passageway as claimed in any one of claims 1, 4, 5 or 6 or a gas rail as claimed in any one of claims 2, 3, 4, 5 or 6 in which the first flow control valve comprises a flow control member adapted to enter the passageway to terminate the supply of gaseous fuel from the one part to the other part.

8. A passageway as claimed in claim 7 or a gas rail as claimed in claim 7 in which the flow control member is resiliently biassed into a position in which it is clear of the passageway.

9. A gas rail as claimed in claim 3 or any one of claims 4-8 when appended to claim 3 in which a surface of the rail is contoured to provide areas each of which co-operates with a moving part of one of the series of further flow control valves to control fuel flow from the passageway.

10. A gas rail as claimed in claim 9 in which each area also forms a part of the housing of the further flow control valve.

11. A gas appliance having one or more top burners, a lid movable between an open position giving access to the burner or burners, and a closed position in which the lid covers the top burner or burners, and a gas rail as claimed in any one of claims 2-10 in which the lid is operatively connected to the first flow control valve in a manner such that the latter prevents fuel flow from the one part to the other part when the lid is in its closed position and permits such flow when the lid is in its open position.

12. A gas hob including one or more gas burners supplied with gaseous fuel via one or more gas flow control valves mounted upon a gas rail with an internal fuel supply passageway, the supply of fuel to the passageway being controlled by a first fuel flow control valve having a flow control member of a resilient material adapted to enter the passageway to close the latter to prevent the supply of fuel to the control valve.

13. A gas hob as claimed in claim 12 in which the flow control member of the gas hob may be resiiiently biassed into a position in which it is clear of the passageway.

14. A gas hob as claimed in claim 12 or 13 and further comprising a lid movable between an open position giving access to the burner or burners and a closed position in which the lid covers the burner or burners, and in which the lid is operatively connected to first flow control valve in a manner such that the latter is operated to prevent fuel flow into the passageway when the lid is in its closed position and to permit such flow when the lid is in its open position.

15. A gas appliance as claimed in claim 11 or a gas hob as claimed in claim 12, 13 or 14 in which the closing weight of the lid may be counterbalanced, at least partially, the operative connection to the first control valve being effected via the counterbalance.

16. A gas appliance as claimed in claim 11 or 15 or a gas hob as claimed in any one of claims 12-15 and including warning means operable on movement of the lid into its closed position unless the or each top burner is "OFF".

17. A gas appliance as claimed in claim 11 or 15 or a gas hob as claimed in any one of claims 12-15 and including warning means operable on movement of the, lid into its open position unless the or each top burner is "OFF".

18. A gas appliance as claimed in any one of claims 11 or 15-17 or a gas hob as claimed in any one of claims 12-17 in which latching means is provided for retaining the first control valve operated once operation on lid movement from open to closed position has taken place.

19. A gas appliance substantially as herein described with reference to and as illustrated by the accompanying drawings.

19. A gas appliance or a hob as claimed in claim 18 in which the latching means is released to allow the first control valve to return to a non-operated condition only when all the top burners are "OFF".

20. A gas appliance or hob as claimed in claim 18 in which manually operable means is provided for releasing the latching mechanism to return to its non-operated condition.

21. A fluid flow control valve assembly comprising a passage having an inlet and an outlet, and a control valve with a flow control head of a resilient material, the head being adapted, in the closed position of the control valve, to enter and close the passage.

22. An assembly as claimed in claim 21 in which the flow control head is resiliently biassed into a position in which it is clear of the passage.

23. A fluid flow control valve assembly substantially as herein described with reference to and as illustrated by Figs. 3 and 4 of the accompanying drawings.

24. A gas rail substantially as herein described with reference to and as illustrated by Figs. 1-4 of the accompanying drawings.

25. A gas appliance as claimed in claim 11 substantially as herein described.

26. A gas hob as claimed in claim 12 substantially as herein described.

27. A gas cooker substantially as herein described with reference to Fig. 6 of the accompanying drawings.

CLAIMS Amendments to the claims have been filed, and have the following effect: New or textually amended claims have been filed as follows:

1. A gas appliance having one or more top burners; a lid movable between an open position giving access to the burner or burners, and a closed position in which the lid covers the top burner or burners; and a gas rail hav ing a gaseous fuel supply passageway divided into two parts by a first fuel flow control valve and having a gaseous fuel inlet in direct communication with one part only of the rail and with the other part via the first flow control valve, in which the lid is operatively connected to the first flow control valve in a manner such that the latter prevents fuel flow from the one part to the other part when the lid is in its closed position and permits such flow when the lid is in its open position.

2. A gas appliance as claimed in claim 1, in which the gas rail has a series of gaseous fuel outlets, at least one of which is in one of the parts and the remainder of which are in the other part, and including a series of further gaseous fuel flow control valves each of which controls fuel flow from the associated part of the passageway via a respective one of the outlets.

3. A gas appliance as claimed in claim 1 or claim 2, in which the gas rail is of one-piece construction.

4. A gas appliance as claimed in any one of the preceding claims, in which the inlet is located at one end of the gas rail and the other end of the rail is closed.

5. A gas appliance as claimed in any one of claims 1 to 3, in which the gas rail is closed at both ends, the inlet being located at a site along the length of the one part.

6. A gas appliance as claimed in any one of the preceding claims, in which the first flow control valve comprises a flow control member adapted to enter the passageway to terminate the supply of gaseous fuel from the one part to the other part.

7. A gas appliance as claimed in claim 6, in which the flow control member is formed from a resilient material.

8. A gas appliance as claimed in claim 6 or claim 7, in which the flow control member is resiliently biassed into a position in which it is clear of the passageway.

9. A gas appliance as claimed in claim 2 or any one of claims 3 to 8 when appended to claim 2, in which a surface of the rail is contoured to provide areas each of which cooperates with a moving part of a respective one of the further flow control valves to control fuel flow from the passageway.

10. A gas appliance as claimed in claim 9, in which each area also forms a part of the housing of the further flow control valve.

11. A gas appliance as claimed in any one of the preceding claims, in which the closing weight of the lid is counterbalanced, at least partially, the operative connection to the first control valve being effected via the counterba lance.

12. A gas appliance as claimed in any one of the preceding claims, and including warning means operable on movement of the lid into its closed position unless the or each top bur ner is "OFF".

13. A gas appliance as claimed in any one of claims 1 to 11 and including warning means operable on movement of the lid into its open position unless the or each top burner is "OFF".

14. A gas appliance as claimed in any one of the preceding claims, in which latching means is provided for retaining the first control valve operated once operation on lid movement from open to closed position has taken place.

15. A gas appliance as claimed in claim 14, in which the latching means is released to allow the first control valve to return to a non-operated condition only when all the top burners are "OFF".

16. A gas appliance as claimed in claim 14, in which manually operable means is provided for releasing the latching mechanism to return to its non-operated condition.

17. A gas appliance as claimed in any one of claims 6 to 8, in which the first flow control valve is substantially as herein described with reference to and as illustrated by Figs. 4 and 5 of the accompanying drawings.

18. A gas appliance as claimed in claim 1, in which the gas rail is substantially as herein described with reference to and as illustrated by Figs. 1 to 3 of the accompanying drawings.