Gas appliance

Abstract

 Improvements on instant lighting devices in built-in safety valves used in gas appliances; particularly in house hold appliances with one or more burners. Each of these devices includes a printed circuit (2) equipped with a selector (5) for the feed by means of a trigger (6), to a valve which controls the flow of gas to the burner once an external button (3) is pressed. The burner is lit by means of time delay (10) or flame ionization, and at the same instant an auxiliary current supply to the magnetic group of the valve is produced. This current is timed, and it replaces the electrical current generated by a thermocouple (4) when it is heated by the flame of the burner.

Description

[0001] This invention comprises various improvements made on instant lighting devices in built-in safety valves based on flame control, used in gas operated household appliances or any other industrial appliance containing one or more burners.

[0002] Certain safety valves based on flame control are already familiar. These valves are used in household appliances running on gaseous fuel, are of the thermoelectric type, and utilize electrical energy generated by the heating of a thermocouple, either by the flame of a pilot light, or by the bumer itself.

[0003] The electrical energy generated flows through the coil of an electromagnet assembly, and this action makes it possible for safety valve to remain open, allowing for the flow of the gas to the burner it controls. The absence of a flame and the outflow of gas that is not burned, make it impossible for the thermocouple to remain hot, and therefore no electrical energy allowing for the activacion of the electromagnet is produced. As a result, the valve controlling the flow of the gas closes.

[0004] It must be kept in mind that the electromagnetic system does not generate sufficient energy to attract thesafety valve on the assembly. It produces only enough energy to keep the valve closed, which therefore must be activated manually to overcome the force of the built-in spring. This spring is activated, shutting off the gas, when the temperature is not high enough to obtain the thermoelectric energy necessary to maintain the safety valve open.

[0005] In reality, the magnetic force of attraction should only be slightly greater than the force of the tension caused by the spring of the safety valve; this level of force is achieved with very low consumption of electrity.

[0006] This action is produced by means of the following steps, taken by the person using the appliance:

• The control knob, which acts on the gas burner, is set in the position for lighting.
• The control knob should be pressed down completely in order to displace the safety valve by means of a rod, and thus allow for the free flow of gas.
• The gas lighting system should be activated by means of the known procedures, such as: applying a flame; or lighting with sparks, by means of piezoelectricity, or with a manual or automatic spark lighter.
• After lighting, the end of the thermocouple should heat up, reaching a temperature which will generate sufficient electrical energy for the safety valve to remain open.

[0007] This is achieved over time, from the moment the gas is lit, and involves the inconvenience of having to hold down the control knob during these operations.

[0008] After this, the control knob is released, and the pilot light remains lit.

• If it does not light after any given attempt, the lighting operation should be repeated. The time that the control knob must be held down depends primarily on two factors:
• The time required to heat the thermocouple (from 5 to 10 seconds), depending on the thermocouple.
• The time required for the gas to reach the pilot, or turner, which heats the thermocouple. This time may vary considerably, as it depends on whether the installation is of a longer or shorter circuit, and on whether air has entered due to replacement of the butane tank or various other causes.

[0009] These inconveniences, which are currently familiar, are overcome with this invention, as it is no longer necessary to continuously hold down the control knob in order to keep the safety valve open. This is because an auxiliary energy supply, equivalent to that produced by the heated thermocouple, is provided to the circuit of the magnetic group and thermocouple, and this allows the valve to remain open for a short period of time without the user having to continuously hold down the button. The gas is lit automatically by means of a spark lighter which is activated with time delay or by ionization each time the button is pressed.

[0010] Thus, in the case of the invention, the steps the user would take for lighting are as follows: following steps:

• Turn the control knob to the light position.
• Press down completely and release, repeating this action if lighting is not successful.

[0011] The invention, therefore, is based on the fact that once the control knob of the device is in position for lighting, at the same time that the rod is pressed, thus activating the valve with the magnetic group, a contact, or electric microswitch is established which sets off the time-delayed spark lighter and the flow of an auxiliary current to the magnetic group, timed to replace for a few seconds the electrical current which will then be generated by the thermocouple once the latter is heated.

[0012] The instant lighting device, object of the invention, consists of the following:

• An isolation transformer.
• A supply source with storage cell.
• A printed circuit with outtets for feeding and timing the spark lighter and an auxiliary current to the thermocouple and the magnetic group.
• A trigger controlling the flow to one valve or the other in the event that there is more than one burner. This prevents the possibility of activating two valves at the same time.

[0013] A selector to support the above function in the event that the circuit to be fed consists of more than one valve.

[0014] The lighting system may be operated in two different manners; that is, by time delay or by ionization of the flame.

[0015] Time delayed lighting is effected when the microswitch or button is activated and gives the signal beginning from zero, in which case the spark lighter is in operation for 5 seconds, and at the same time, the auxiliary current source to the thermocouple is activated for approximately 6 to 11 seconds.

[0016] The time difference between the 5 seconds that the spark lighter is activated to light the gas, and the 11 seconds for allowing the auxiliary energy supply to reach the magnetic group, is approximately 6 seconds. This is the amount of time necessary to heat the thermocouple and generate the current needed to substitute the auxiliary energy being used.

[0017] Lighting by means of flame ionization is carried out as follows. When the microswitch or control button is activated, the spark lighter and the auxiliary electrical current the magnetic thermocouple group are set off, and the pilot and(or burner is lit. Thus, a flame is produced, and by means of the effect of ionization, a signal is received indicating that the flame is burning, at which point the spark lighter stops functioning. At this very moment, a timer is set off, which after 6 seconds, cuts off the supply of the auxiliary electrical current to the thermocouple and magnetic group.

[0018] In both systems, or forms of lighting, once 10 or 11 seconds have passed and lighting has not taken place, the operation is nullified, and the control buttom must be pressed again.

[0019] The familiar automatic lighting systems, which depend on electrical energy from the house current, serious inconveniences arise, as appliances operating on gas fuels cannot be used in households when there is an electrical power failure in the house current for any reason.

[0020] With the invention, this possibility is avoided completely by the use of a supply source with a storage cell, made of silicon or a similar material, and having a very low operating voltage, approximately 3.6 volts, allowing for 100 to 300 lights without the need for external energy from the house current, due to the low consumption of electricity necessary to effect the lighting operation.

[0021] In addition, it is possible to considerably prolong the life of the storage cell, since when lighting is effected, energy from the cell is consumed, but since it is connected to the house current by means of a transformer, the cell is immediately recharged.

[0022] Keeping in mind the low consumption of energy necessary in order for lighting to take place, the device may be used either connected to the house electrical current, or, as a temporary measure, without external electrical energy. And lighting takes place instantly and immediately without the need for continuous pressing of the control button while the gas is being lit and the thermocouple is being heated.

[0023] Finally, it should be pointed out that once the flame heating the thermocouple is extinguished, the thermocouple, which generates the energy necessary to keep the safety valve open, cools off, and the energy produced decreases. When the energy decreases to approximately 1/3, the absense of the flame is detected, and the circuit stops functioning automatically. At this point the safety valve closes, preventing the flow of gas to the pilot or burner(s).

[0024] While the thermocouple is being heated, the circuit remains out of operation, even if the lighting system is activated, thus no energy is consumed.

[0025] To allow for easier understanding, not only of the construction, but also of the correct use of the instant lighting device of the invention, a practical example of operation is provided below, just as is shown in the corresponding schematic diagram. This explanation is merely illustrative and operation is not in any way restricted to the example given.

[0026] The device (1) consists of a printed circuit (2) which includes a set of pushbuttons (3) by means of which the valves controlling the flow of gas to the burner (not shown for the appliance for household use), are activated.

[0027] When the device has more than one valve, or likewise, more than one burner, and as a result has varlous thermocouples (4), the circuit is equipped with a selector (5), so that by means of a trigger (6), a single valve may be selected for use with the corresponding supply.

[0028] One the pushbutton (3) is pressed, the burner is lit by means of a spark lighter (7), and the supply of an auxiliary current is provided to the magnetic group of the valve.

[0029] The supply source (8) can be used with a storage cell, and can also be connected to the circuit by an isolation transformer (9).

[0030] Both the isolation transformer and the thermocouples (4) together with the spark lighter (7), are controlled by means of timers (10), and in both cases operate on transistors (11).

Claims

1.- Improvements in instant lighting devices in built-in safety valves in gas appliances, particularly those appliances for household use having one or more burners; characterized in that these devices comprise a printed circuit equipped with a selector for directing the supply, by means of a trigger, to a valve which controls the flow of gas to the burner once an external button is activated, lighting the burner with time delay, or by flame ionization, at which moment the supply of an auxiliary current is produced to the magnetic group of the valve. This current is timed and replaces the electrical current generated by a thermocouple once the latter is heated by the flame of the burner.

2.- Improvements In accordance with claim 1, characterized in that the auxiliary current supply consists of a supply source with storage call, and the supply source is connected directly or by means of an isolation separator, to the house electrical current.

3.- Improvements in accordance with claim 1, characterized in that time-delayed lighting is produced once the device begins functioning; a spark lighter which lights the gas in the burner, and at the same time the source of an auxiliary current flow from the timer, with the duration of the auxiliary current being greater than that of the functioning of the spark lighter.

4.- Improvements in accordance with claim 1, characterized in that upon pressing the external button and providing electrical energy to the lighting system, the spark lighter will stop working if the existence of a flame is detected by ionization will stop working, and at that moment a timer is set off providing the auxiliary current to the thermocouple for approximately 6 seconds.

5.- Improvements in accordance with claim 1, characterized in that once the thermocouple is heated, if the control button is pressed, the electrical circuit is not in use and does not consume energy.

6.- Improvements in accordance with claim 1, characterized in that once the termocouple is heated, if the begins to cool off, when the voltage drops, the electrical functioning stops, and the safety valve closes.

Drawing