The present invention relates to a sealing cap for a nozzle in a sprinkler system, where the nozzle is shaped as a spray nozzle of the turbo type which is connected in series in the sprinkler system, and that the sealing cap is positioned over the nozzle and arranged to protect the nozzle lying inside.

The invention is particularly concerned with spray nozzles with a cap or hood for fire extinguishing nozzles which are to be used in polluted environments, and which are arranged to protect the nozzle against oxidation, dirt, dust and particles, and where the cap is self-releasing with one form or another of external influences or activation.

WO 01/26471 discloses a solution for sprinkler systems where the cover is kept in place over the nozzle in a protective condition to protect against dust and pollution, and also to act as a heat foil. The cover is kept in place with the help of a retaining arrangement and is released by the pressure which is exerted when the sprinkler system/nozzle is put under pressure.

The object of the present invention is to provide a sealing cap for a nozzle which protects the nozzle against dirt, dust, etc. , and which can quickly be released from the nozzle in case of fire. It is also an object to provide a sealing cap that is inexpensive and simple to produce, and which also may be used on existing nozzles.

To fulfil the mentioned objects, a sealing cap for a nozzle, which is characterised by the characteristic part of claim 1, is provided, in that the whole or parts of the sealing cap is formed from a material that is arranged to be deformed or disintegrated, at a pressure or heat influence, whereby the sealing cap is arranged to be released or disengaged from the nozzle.

Alternative embodiments of the invention are characterised by the dependent claims 2-11, in that the material from which the whole or parts of the sealing cap is made of is arranged to be deformed in that the sealing cap is subjected to the influence of heat, or that the material from which the whole or parts of the sealing cap is made of is arranged to disintegrate in that the sealing cap is subjected to a pressure influence.

The sealing cap can comprise a sealing means which is arranged inside the cap, where the sealing means is preferably fitted in an internal, circular groove adjacent to the opening of the sealing cap. The nozzle will correspondingly comprise an outer circular groove arranged to receive the sealing means.

Furthermore, the sealing cap can, in an alternative embodiment, be comprised of an internal, outwardly extending edge section, where the edge section is arranged circularly, adjacent to the opening of the sealing cap and is arranged to engage with the groove on the nozzle. The sealing cap can comprise heat-influencing means, such as, for example, a copper wire, which is fitted circularly in or around the sealing cap, adjacent to the edge section.

The sealing cap can be comprised of an adjustable spring element, where the spring element is arranged to ease the release of the sealing cap from the nozzle.

The material, which the whole or parts of the sealing cap is made from, can be comprised of a brittle material, such as, for example, thin glass or plastic. Alternatively, the material which the whole or parts of the sealing cap is made of can be comprised of a material with a low yield stress/melting point, such as, for example, plastic/glass, fibre or foam material. Furthermore, the material which the whole or parts of the sealing cap is made from, can be comprised of a material that when subjected to an external heat influence itself, from a chemical reaction, is designed to generate internal heat/energy which speeds up the deformation process, such as, for example, an arti- ficial fibre/foam material.

The invention shall now be explained further with the help of the enclosed figures, in which : Figure 1 shows a standard nozzle of the turbo type.

Figure 2 shows a nozzle with a sealing cap according to the invention.

Figures 3 and 4 shows alternative embodiments of a sealing cap according to the invention.

Figure 5 shows an alternative embodiment of a sealing cap with a spring element according to the invention.

Figure 1 shows a nozzle 10, which, for example, can be a standard water-spray nozzle of the turbo type. The nozzle is connected in series in, for example, tunnels, factory premises and/or other locations where there are floating <BR> <BR> dust, temperature changes, moisture variations, etc. , and is to be used for extinguishing fires.

A protection in the form of a cap or hood 20 is arranged over the nozzle 10A. This sealing cap 20 shall protect the nozzle against fouling when the nozzle is inactive. At, for example, heat influences or other external influences, the nozzle is self-released at a given temperature, or the cap can be released in that the system is activated.

With a chemical reaction, the sealing cap 20 can be arranged to self-inflict the deformation, or the disintegration, so that the cap is loosened or released from the nozzle. The material from which the whole or parts of the cap is made of ought to have a low yield stress, or melting point, so that a rapid reaction in the sealing cap is obtained as a response to an external heat influence, for example, from a fire or another external heat influence.

As shown in figure 2, the sealing cap 20 surrounds the lower part of the nozzle. The nozzle with the sealing cap can be used in a dry system, i. e. for example, in a system where the nozzle is not under constant water-pressure. In such a system, the whole of the sealing cap 20 may be made from a material which is designed to be deformed or disintegrated when subjected to heat or pressure, as, for example, heat that is generated in connection with a fire, but not heat that is generated by the exhaust gases from a vehicle, or the pressure from the jet of water when the system is activated. Even if the whole sealing cap can be made from the mentioned material, it can be sufficient that only an upper part is made from the mentioned material. In this embodiment, the sealing cap 20 prefer- ably is comprised of a sealing means 24, such as, for example, an o-ring, which is fitted on the inside of the cap 20. The sealing means 24 is arranged in an internal, circular groove adjacent to the opening of the sealing cap. Also provided on the nozzle 10 is an outer circular groove 26 arranged to receive the sealing means 24.

Figure 4 shows an alternative embodiment of a sealing cap 20 that preferably is made in part from a material that can be deformed or disintegrated when subjected to heat influence or the influence of pressure. The sealing cap that is shown in figure 4 is preferably intended to be <BR> <BR> used in a wet system, i. e. , a system in which the nozzle is under constant water pressure. Because of the pressure, the sealing cap is formed with an internal, outwardly extending edge section 28. The edge section 28 is arranged circularly adjacent to the opening of the sealing cap and is designed to engage with the groove 26 on the nozzle 10.

The aim of the edge section 28 is, among other things, to keep the sealing cap 20 in place over the nozzle and also to act as a sealing means between the nozzle 10 and the sealing cap 20. Further sealing means can also be provided for additional sealing between the nozzle and the cap.

As mentioned, the sealing cap 20, which is shown in figure 4, can partly be made from a material that is deformed or disintegrated. To further ensure that the sealing cap is released from the nozzle in case of fire, the sealing cap can be comprised of a heat-influencing means 30, such as, for example, a copper wire, that is arranged circularly in or around the sealing cap 20, adjacent to the edge section 28. When subjected to heat from, for example, the copper wire 30, the sealing cap will be deformed or disintegrated sufficiently for the cap to be released from the nozzle 10 in a quick and definite way. For the heat influence means 30 to generate heat, a voltage/current change in the means 30 can be provided with the help of an external detecting and regulating device (not shown).

Figure 5 shows an alternative embodiment of the sealing cap 20, where the sealing cap is comprised of a spring element 32 arranged in the sealing cap. The spring element 32 is preferably arranged opposite the opening of the sealing cap and abuts the nozzle when this is inactive.

The spring element 32 is arranged to provide additional force at the release/disengagement of the sealing cap 20 from the nozzle 10. This embodiment will particularly be relevant if the sprinkler system with the nozzle is mounted in such a way that the sealing cap 20 is fitted on top of the nozzle, i. e. the opening of the sealing cap 20 is pointing downwards, as is shown in figure 5, and where the sealing cap is to be released in an upwardly directed movement, but can also be used in other circumstances.

Furthermore, the elastic force of the spring element can be regulated for adjusting to the type of material which is used, how the release of the sealing cap is to happen, etc. A suitable spring element can, for example, be of a weight of between 10 to 100 grams, but other types can also be used.

It shall also be said that even if it is described here that the sealing cap is deformed or disintegrated when subjected to heat, the sealing cap 20 can also be sufficiently deformed or disintegrated when subjected to, for example, a water pressure. Such a solution will particularly be relevant in connection with a sealing cap as shown in figure 3, but can also be used in connection with an embodiment as shown in figure 4 or 5. When the system is activated, the sealing cap will thereby be deformed or disintegrated sufficiently for the sealing cap 20 to be released from the nozzle.

The sealing cap can also be used in sprinkler systems where foam is used, such that even if this description given here refers to water nozzles, the invention is not limited to systems that use water only as an extinguishing medium.

The material which shall be used in the sealing cap can be a brittle material, such as, for example, thin glass or plastic, which is disintegrated. easily and/or a material with a low yield stress/melting point, such as, for example, plastic/glass, fibre or foam material, which quickly react to an external heat influence. The material that is to be used can also encompass a material which, when subjected to an external heat influence itself, from a chemical reaction, generates internal heat/energy which promotes the deformation process, such as, for example, artificial fibre/foam material.