Sometimes defects and/or malfunctions arise in electrical devices for multiple reasons. If an electrical device is battery-operated, there generally is no danger of fire but devices operated with line voltage (usually 230 V AC) are dangerous, because the device usually gets electrical energy as long as the fuse in the line voltage, usually of 10 A or 16 A of size, is blown or has gone off. The defect can be even such that the said fuse is not blown but the power heating the device due to a defect or a malfunction can be e. g. of the order of 1 kW, even 2 kW or more.

It is clear that such heat power heats the device quickly and as a result, the device generally spunks clearly even in less than a minute from the start of the defect or malfunction. Typical such devices used in homes and offices are televisions, computer hardware, video and music appliances, refrigerators and deep freezers, cold storage rooms, dishwashers and washing machines, copiers etc. Numerous machines and appliances of the same kind are found in properties and in industry.

An object of the invention is to present an arrangement by means of which, as a defect or a malfunction appears or happens, at least some kind of overheating or even spunk of a device is prevented. Thus, an object of the invention is to present an arrangement by means of which an appliance according to the arrangement begins the extinction and simultaneously also renders the appliance powerless so that the supply of electricity would not give extra energy to worsen the overheating and/or an already started fire. An object of the invention is further to present an appliance that is reliable and also safe in the sense that its malfunction would not cause a dangerous situation.

An object of the invention is achieved in the manner described in the independent claim 1 and other claims. According to the invention, there is an arrangement for improvement of security of an electrical device against a defect or malfunction, which arrangement comprises a detector unit placed in connection with the device or at least in its close vicinity for detecting a defect or malfunction, an extinguisher and its trigger arrangement as well as a coupling arrangement for cutting off the operating current. If the container that is used in the extinguisher and that contains pressurized extinction material immediately after triggering brings about in the said coupling arrangement a function in consequence of which the operating current to the device is cut off, the events happen in the right order in the sense that first, a triggering happens and only after that happens the cutting off of the operating current. Then such a security arrangement feeds operating energy to its own appliances till the end, i. e. the detector has had time to detect the situation and to give an order forward to the extinguisher appliance, only after triggering of which happens the cutting off of the power supply and the spreading of the extinction material to the space to be extinguished.

It is recommended that the detector unit has also an alarm function in addition to the detector function. Then, an alarm function is switched on which alarm function is usually some kind of buzzer alarm device or another function based on trouble sound. It is of course possible and recommendable that the appliance is coupled as a part of a larger alarm system, if such a system exists in the building.

If the detector unit gets its operating current from an induction ring that is placed around the operating current conductor of the device, the arrangement receives operating current always when the device under control is on stream. It is of course possible to secure the functions with batteries or accumulators. However, it is important that no danger is caused by these.

If the said triggering arrangement receives an operating impulse from the said detector unit, the triggering happens in the right order and thereby reliably.

If the said triggering arrangement comprises a tensioned spring under influence of which the extinction material container moves after the triggering for a distance in the chamber and extinction material is released from the said container, a very reliable function for activating the current breaking circuit under the influence of the move of the extinction material container and, additionally, the extinction material container hits the tip that pierces the sheet of the extinction material container. Under this effect, the extinction material flows out of the pressurized extinction material container.

If the said chamber has a coupling arrangement which after the triggering provides a short-circuit in the operating current conductors, in consequence of which short-circuit the fuse placed in the operating current conductor is blown, the arrangement has performed in a manner according to the invention till the end, and as a result, the device no longer receives extra energy from the electric network, whereby it is probable that under the influence of the extinction material, the fire in the device is extinguished or at least does not continue effectively.

If the fuse is proportioned to bear the conventional operating current of the device and the starting current but the fuse is smaller in value than a fuse in an electricity-meter board or the like, through which fuse the electricity to the said device is supplied, the security of the device is further improved, because it may be possible that the electric network of the building is old and cannot bear big electrical current even momentarily before a fuse at some moment is blown.

If a so-called extinction cartridge is used as an extinction material container, which cartridge contains pressurized carbon dioxide, nitrogen or some other inert gas or gas mixture, the reliability of the extinction cartridge is great even though the cartridge had been in actuality for years.

If after the triggering the arrangement can be put into working order by changing the expendable parts for a possible new triggering if the arrangement is not otherwise damaged, the service work is easy and fast to perform.

If the components of the arrangement at least mainly have been formed as a unit that is placed in the vicinity of those parts of the said device that become defective or fall into malfunction, the arrangement can be brought into a compact structure that can usually be easily put to a suitable place in the device.

If in connection with the triggering the pressurized material in the extinction cartridge at least mainly passes through a whistle causing an additional alarm sound, an additional function can in this way easily be obtained that draws the attention of persons possibly nearby.

In the following the invention is further described by referring to the appended drawings in which: Figure 1 shows schematically an arrangement according to the invention in form of a coupling diagram in standby readiness and Figure 2 shows schematically the arrangement of Figure 1 in triggered condition.

In Figure 1 of the drawing with reference numeral 1 is marked an arrangement according to the invention for improvement of security of an electrical device in form of a coupling diagram in standby readiness. The actual device is marked with reference numeral 2, the failure and above all the fire safety of which device the arrangement 1 controls. Usually, the arrangement 1 is placed inside the device 2, for the arrangement 1 is approximately fitting to a hand in size, whereby it fits excellently e. g. inside a television. The arrangement 1 and the device 2 receive their operating energy usually from the electrical network of the building, which network gives a voltage of 230 V AC, usually through a fuse of 10 A or 16 A from the electricity board. The reference numeral 3 designates a contact plug. The feed line 4 has a fuse 5 that is lower in value than the said fuse of the electricity board. The fuse 5 can be a glass tube fuse 5x20 or 6x30 and in an adapter or a fuse holder (not shown) and yet in value such that it bears the normal operating current and the starting current of the device 2. E. g. for a

television, the fuse size 2 A or at most 3 A can be suitable. To the device 2, another conductor 6 goes through a chamber 7 and inside the chamber 7 the conductor 6 is without the protector part.

A detector unit 8 is usually placed inside the device 2, and it is in its functions like a conventional fire detector. It is recommended that the detector unit 8 also comprises an alarm device that gives a loud sound signal as the detector unit 8 triggers. The source of operating energy of the detector unit 8 is a current loop 9 that is formed of a ring-like coil which is around the feed line 4 and of an amount of coil through the ends of which the lines 10a and 10b take operating energy in alternating current form to the detector unit 8. In Figure 1, the conductor going towards the device 2 has been drawn to pass directly through the current loop 9 but this line is recommended to be winded some turns (e. g. 5 to 15) around the ring (usually a ferrite ring). Other solutions can of course be thought to be applied here too. Rectification, blocking and stabilization circuits have not been drawn, because they are generally known. In the detector unit 8, can also have as an energy source a battery or an accumulator and also a capacitor, e. g. 2200 to 4700 F or more. Operating voltage can be e. g. 9 V. When the detector unit 8 detects smoke, the detector unit 8 starts to give current along lines 11 a and 11b to a solenoid 12 that so to speak draws and releases the tensioned pressure spring 13 that is in the chamber 7 abutting on the end of the chamber 7. The spring 13 catapults the extinction cartridge 14 into move within the chamber 7.

The metal cased extinction cartridge 14 short-circuits on its way the loop 15 and the terminal 16 of the line 6, under influence of which the fuse 5 is blown, after which electrical energy no longer reaches the device 2 nor the arrangement 1.

From the Figure 2 can be seen the functioning of the extinguisher and the coupling arrangement in recently triggered state. The extinction cartridge 14 flushes to the tip 17 at the end of the chamber 7, which tip pierces a sheet at the end of the extinction cartridge 14, under the influence of which the fire suffocating gas in high pressure in the extinction cartridge 14 is released out inside the device 2 as a jet 18. If it can be suspected that one extinction cartridge 14 is not

sufficient to suffocate the fire, two chambers 7 and two cartridges 14 can be used. The sufficiency of power supply for two solenoids 12 has to be secured e. g. by enlarging the said capacitor. The loop 15 and the terminal 16 can be replaced e. g. by a microswitch, the probe arm of which, moving under the influence of the move of the extinction cartridge 14, short-circuits the line 6 and the line 19. It is also possible to provide such an additional function that the tip 17 has been placed in a bevelled, in relation to the extinction cartridge a little tight tube, into which the extinction cartridge 14 is funnelled and under the influence of the tip 17, the sheet is broken as the extinction material is released from the cartridge 14.

The pressurized material can be directed to pass through a whistle (not shown), whereby a high-pitched additional warning sound of a few seconds is generated for catching the attention of persons that are possibly nearby, due to a fault situation. The extinction material of course spreads to the target in almost the same manner but this time through a whistle.

It can be seen from the coupling that the current loop 9 takes energy only when the device 2 is on, i. e. takes energy from the electrical network. As the detector unit 8 does not receive current through lines 10a and 10b when the device 2 is off and starts to receive current when the device 2 starts to receive current, in the coupling it has to be taken care of that the detector does not sound the alarm to the solenoid 12 when the power is switched on or right after it.

When the device has detected e. g. a starting fire in a television as it is placed inside the television and as the arrangement has triggered and extinguished the fire and switched the device 2 and the arrangement 1 currentless, an expert can change the fuse 5 and the cartridge 14, terisioning also-the spring 13 back to tension. Then the arrangement 1 is again in working order, if no damages have occurred. Of course, the television needs to be repaired and the damaged parts need to be changed to it, as well as its working order needs to be also otherwise checked after a defect or a fire.

The invention is not limited to the accompanying embodiment but various variations of it are thinkable within the scope of the appended claims.