AU2002214834B2 - Shut-off safety system and gas appliance including same - Google Patents

Description

WO 02/40923 PCT/AU01/01491 SHUT-OFF SAFETY SYSTEM AND GAS APPLIANCE INCLUDING SAME The present invention relates to a shut-off safety system for gas appliances, and also to gas appliances which include such a shut-off safety system. In particular, the invention relates to a safety system which is operable to prevent the flow of gas to gas burners where, for example, one or more burners is burning uncontrollably.

Generally, gas appliances such as ovens, hot water services or heaters include an inlet which is connected to a gas mains source and one or more burners which receive and burn gas for the desired purpose, such as cooking or heating. In some instances, particularly in relation to gas stoves used for food preparation, gas burners may burn uncontrollably, for example when hot oil is spilled from a cooking vessel onto the burner. In such instances, it is necessary to stop the flow of gas to the burner or burners in question so as to extinguish the uncontrolled flame. Generally this is achieved by means of a manual shut-off valve located on the inlet to the gas appliance. However, in many instances, this shut-off valve is not readily accessible to a user of the appliance, and may indeed not be accessible at all if there is an uncontrolled flame present. In instances where such a shut-off valve is not accessible, it may even be necessary to shut off the gas mains source to the appliance in order to extinguish the uncontrolled flame. This may involve some time, thus worsening the nature of the situation.

The present invention aims to provide an alternative shut-off system to that presently available as described herebelow.

According to one aspect of the invention there is provided a shut-off safety system for gas appliances comprising: a flame failure valve which in use receives gas from a gas mains source and which includes a gas outlet for supplying gas to at least one gas burner; a control flame gaseously connected to the flame failure valve and remote from the at least one gas burner such that it is readily accessible to a user; and WO 02/40923 PCT/AU01/01491 -2a thermocouple associated with the control flame and connected to the flame failure valve; wherein the thermocouple is associated with the control flame such that when the control flame is extinguished, the thermocouple causes the flame failure valve to close preventing the supply of gas from the gas mains source to the at least one gas burner.

In accordance with the invention, the control flame is remote from the gas burner of the appliance and is associated with a thermo-couple which, on extinguishing the control flame causes a flame failure valve of the system to close, thus preventing further supply of gas from the gas mains source to the burner. As such, given that the control flame is remote from the burner, the control flame may be accessed by a user of the appliance even though a flame may be burning uncontrollably on one of the burners. The connection between the thermocouple and the flame failure valve may be an electrical or magnetic connection and may include one or more solenoids.

In one embodiment, the control flame is not only remote from the at least one gas burner, but is also remote from the flame failure valve, and is preferably connected to the flame failure valve by means of a conduit. Even more preferably, the conduit includes a manual shut-off valve operable between open and closed positions for permitting or preventing the flow of gas from the flame failure valve to the control flame. Such a manual shut-off valve may be closed by a user of the appliance after the control flame is extinguished to ensure that the flow of gas from the flame failure valve to the control flame is prevented, thus definitely ensuring the shut-off of gas to the gas burner.

The shut-off safety system according to the invention may if desired be housed within the gas appliance itself. In this case, the control flame is preferably housed within the gas appliance at a position which is remote from the at least one gas burner and at a position which is readily accessible to a user of the appliance. For example, the control flame may be positioned on one side of the gas appliance, or may be positioned, in the case of an oven, on a rear console of the appliance. It will be understood that the positioning of the control flame may be dictated to some extent by the configuration of the gas appliance in WO 02/40923 PCT/AU01/01491 -3question.

In another embodiment, the shut-off safety system is not included in the gas appliance, but is remote from the gas appliance. In this case, again, there may be provided a manual shutoff valve for permitting or preventing the flow of gas from the shut-off safety system to the gas appliance. For example, the manual shut-off valve may be positioned on an inlet conduit to the gas appliance, or on an inlet to the shut-off system itself.

For facilitating ignition of the control flame, the shut-off safety system is advantageously provided with an ignition button. In a preferred embodiment, the flame failure valve includes an ignition button for facilitating ignition of the control flame.

According to another aspect of the invention, there is provided a gas appliance comprising: at least one gas burner; a flame failure valve which in use receives gas from a gas mains source and which includes a gas outlet for supplying gas to the at least one gas burner; a control flame gaseously connected to the flame failure valve and remote from the at least one gas burner; and a thermocouple associated with the control flame and connected to the flame failure valve; wherein the thermocouple is associated with the control flame such that when the control flame is extinguished, the thermocouple causes the flame failure valve to close preventing the supply of gas from the gas mains source to the at least one gas burner.

Reference will now be made to the accompanying drawings which illustrate particular embodiments of the present invention, but which should not be construed as limiting on the invention in any way and in which: Figure 1 illustrates a gas appliance in the form of an oven which includes a shut-off safety system; Figure 2 illustrates the oven of Figure 1 further including a manual shut-off valve; WO 02/40923 PCT/AU01/01491 -4- Figure 3 illustrates a series of gas appliances and a remote shut-off safety system.

Referring to Figure 1, there is illustrated an oven 10 which includes a shut-off safety system 11. The safety system 11 includes a flame failure valve 12 which is provided with an inlet 13 which receives gas from a gas mains source pipe 14. The gas mains pipe 14 is provided with a valve 15 for preventing the flow of gas to the flame failure valve 12.

A control flame 16 of the safety system 11 is gaseously connected to the flame failure valve 12 by means of a conduit 17. Thus, the control flame 16 may be supplied with gas from the flame failure valve 12. The control flame 16 is associated with a thermocouple 18 which is electrically connected to the flame failure valve 12 by wiring 19. The association between the control flame 16 and the thermocouple 18 is such that when the control flame is extinguished, the thermocouple 18 is switched to cause closure of the flame failure valve 12.

The flame failure valve 12 also includes an outlet 20 which is connected to a plurality of burner inlets 21 which supply gas to gas burners of the oven 10. On closure of the flame failure valve 12, gas flow through the outlet 20 to the gas burner inlets 21 is prevented, thus preventing any flow of gas to the gas burners of the oven 10. As such, if a flame is burning uncontrollably on the oven 10, the control flame 16 may be extinguished resulting in closure of the flame failure valve 12, and consequently prevention of the flow of gas to the burners.

With reference to Figure 2, an oven 10 is again illustrated. However, in this case, the conduit 17 which supplies gas from the flame failure valve 12 to the control flame 16 includes a manual shut-off valve 24. In this case, after the control flame 16 has been extinguished, the flow of gas from the flame failure valve 12 to the control flame 16 can be definitely prevented by closing the shut-off valve 24. Alternatively, if the control flame 16 is not readily accessible at the time at which it is desired to extinguish the control flame 16, then the shut-off valve 24 may be closed to prevent further flow of gas to the control flame 16.

WO 02/40923 PCT/AU01/01491 Referring to Figure 3, the shut-off safety system 31 may also be remote from a gas appliance, or in this case a number of gas appliances arranged in series 30. In this case, the remote safety system 31 includes a flame failure valve 32 which receives gas from a mains gas source, a control flame 36 and an associated thermocouple 38. Each of these components acts as set out hereabove.

The gas appliance to which the remote system 31 is attached to may also include its own shut-off safety system 11 as also set out hereabove.

Where a safety system is provided in a series of gas appliances, this may act to prevent gas flow to the entire series of gas appliances on extinguishing the control flame of the system.

Alternatively, each of the appliances in the series may include its own shut-off safety system. The configuration of such a series of gas appliances may be determined in any particular instance.

Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

The reference to any prior art in this specification is not, and should not be taken as, an acknowledgment or any form of suggestion that that prior art forms part of the common general knowledge in Australia.

Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described. It is to be understood that the invention includes all such variations and modifications which fall within its spirit and scope. '[he invention also includes all the steps, features, compositions and compounds referred to or indicated in this specification, individually or collectively, and any and all combinations of any two or more of said steps or features.

Claims (9)

1. A shut-off safety system for gas appliances comprising: a flame failure valve which in use receives gas from a gas mains source and which includes a gas outlet for supplying gas to at least one gas burner; a control flame gaseously connected to the flame failure valve and remote from the at least one gas burner; and a thermocouple associated with the control flame and electrically connected to the flame failure valve; wherein the thermocouple is associated with the control flame such that when the control flame is extinguished, the thermocouple causes the flame failure valve to close preventing the supply of gas from the gas mains source to the at least one gas burner.

2. A shut-off safety system according to claim 1, wherein the control flame is remote from the flame failure valve and is connected to the flame failure valve by means of a conduit.

3. A shut-off safety system according to claim 2, wherein the conduit includes a manual shut-off valve operable between open and closed positions for permitting or preventing the flow of gas from the flame failure valve to the control flame.

4. A shut-off safety system according to claim 1, wherein the shut-off safety system is housed within the gas appliance.

5. A shut-off safety system according to claim 4, wherein the control flame is housed within the gas appliance at a position remote from the at least one gas burner and at a position which is readily accessible to a user of the appliance.

6. A shut-off safety system according to claim 1, wherein the shut-off safety system is remote from the gas appliance. WO 02/40923 PCT/AU01/01491 -7-

7. A shut-off safety system according to claim 6, including a manual shut-off valve operable between open and closed positions for permitting or preventing the flow of gas from the shut-off safety system to the gas appliance.

8. A shut-off safety system according to claim 1, wherein the flame failure valve includes an ignition button for facilitating ignition of the control flame.

9. A gas appliance comprising: at least one gas burner; a flame failure valve which in use receives gas from a gas mains source and which includes a gas outlet for supplying gas to the at least one gas burner; a control flame gaseously connected to the flame failure valve and remote from the at least one gas burner; and a thermocouple associated with the control flame and electrically connected to the flame failure valve; wherein the thermocouple is associated with the control flame such that when the control flame is extinguished, the thermocouple causes the flame failure valve to close preventing the supply of gas from the gas mains source to the at least one gas burner.