Technical Field

The present invention relates to an automated fire protection system for a fire hazardous area, such as a stove or an area in an industrial process.

Background of the Invention

Conventionally, extinguishing a fire on a fire hazardous area, such as a stove, has been performed by manually covering the fire with a fire blanket. A fire blanket is adapted to be placed on and smother a fire. However, if there is no one present at the time of fire an automated system for extinguishing the fire is advantageous.

Fire protection systems using a fire blanket are known from for example document JP 2005185813. Document JP2005185813 teaches a system wherein a fire blanket is located in a box mounted above a stove. In case of fire, the box opens and the fire blanket falls toward the stove to extinguish the fire. However, even if the intent is to provide a secure fire protection system, there is nothing ensuring that the fire blanket lands on the fire. Instead, it may land beside the fire or even beside the stove, it may become folded when it lands, or stay in a folded state if it was folded in the box. Therefore, there is a need for a fire protection system for a fire hazardous area using a fire blanket, which system is accurate and efficiently extinguishes the fire.

Summary of the Invention In view of the above mentioned need, a general object of the present invention is to provide a more accurate and efficient fire protection system for a fire hazardous area. This and other objects are achieved through an automated fire protection system for a fire hazardous area, the system comprising a fire blanket, and a deployment assembly for deploying the blanket over said area. The deployment assembly comprises an airbag and an inflator device for inflating the airbag from an uninflated state to an inflated state, wherein the airbag in the uninflated state is arranged in relation to said fire blanket so as to unfold the fire blanket when the airbag is inflated, and wherein the airbag in the inflated state has a shape so as to guide the fire blanket to cover the area.

The present invention is based on the understanding that an airbag can be designed to rapidly inflate in a certain direction In use, the airbag guided fire blanket will thus rapidly and securely cover the fire hazardous area, and extinguish any fire.

Moreover, when the airbag is in the uninflated state, the fire blanket may be stowed between the airbag and the fire hazardous area, so that the fire blanket is pushed towards the fire hazardous area when the airbag inflates. Such an arrangement may result in a compact system.

The airbag may be inflated in only one location. Alternatively, it may be advantageous to inflate the airbag in at least two locations. By introducing air into the airbag in several locations, the airbag may be faster and more evenly inflated..

According to one embodiment, the airbag comprises inflatable channels, which channels form a grid. Such air channels may easily be adapted to the size of the fire blanket as well as the size of the fire hazardous area. A grid-formed airbag may cover a relatively big area in relation to the required air volume by which it is inflated. Moreover, when the airbag is formed like a grid it may guide the fire blanket toward a relatively big area without requiring much space in its uninflated state.

The airbag may advantageously be folded together with the fire blanket, so as to form an interleaved unit. Such folding may render the guiding of the fire blanket even more accurate and efficient, when the airbag inflates.

The automated fire protection system may further comprise a detector for detecting a fire and transmit a signal to the inflator device. A detector may for example be a smoke detector, an infrared sensor or a safety fuse. Further, the inflator device may comprise a pressurized gas cartridge and a puncture device, adapted to rapidly perforate the cartridge to release the gas, for inflating the airbag sufficiently fast. Inflating the airbag by means of pressurized gas, such as carbon dioxide, is advantageous, since a suitable pressure for the airbag to inflate sufficiently fast and accurately guide the fire blanket is easily obtained.

The puncturing device may comprise a spring loaded puncturing pin, for perforating the pressurized gas cartridge, a catch for engaging said puncturing pin to secure the puncturing pin in a spring loaded resting position, and a release lever connected to the catch, for bringing the catch out of engagement with the puncturing pin. Such a design provides easy control of the activation of the puncturing device.

According to one embodiment, the catch is rotatable around an axis extending in a direction transverse a direction of movement of the puncturing pin between a first position, in which the catch engages a recess in the puncturing pin and a second position, in which the catch is out of engagement with the recess. The release lever can then be arranged to rotate the catch between the first and second position. With this design, a relatively weak force is required to hold the release lever in place, compared to the relatively strong spring force acting on the puncturing pin.

The fire protection system may moreover comprise an enclosure, in which the fire blanket, the airbag and the inflator device may be arranged. The enclosure may be adapted to open when the airbag inflates. Such enclosure may easily be mounted on for example a wall in order to arrange the fire protection system so as for the fire blanket to extinguish a fire on a certain area efficiently.

Brief description of the drawings The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which currently preferred embodiments of the invention are shown.

Figure 1 a is a perspective view of an automated fire protection system according to an embodiment of the present invention, when the airbag is in the uninflated state.

Figure 1 b is a perspective view of the automated fire protection system in figure 1 , when the airbag is in the inflated state. Figure 2a is a perspective view of an automated fire protection system according to an embodiment of the present invention, illustrating an example of an airbag arrangement, in the uninflated state.

Figure 2b is a perspective view of an automated fire protection system according to an embodiment of the present invention, illustrating an example of an airbag arrangement, in the inflated state.

Figure 3 is a perspective view of a puncturing device.

Figure 4 is a perspective view of an example of a fire blanket and airbag folding according to an embodiment of the present invention.

Detailed description of preferred embodiments

The present invention will now be described with reference to an implementation above a stove. However, it should be noted that the invention may advantageously be used also in other fire hazardous areas. Examples of environments that may comprise such areas include, but are not limited to, chemical laboratories and process industry, welding machinery and robots, forging machinery, metal processing machinery, battery loading stations, and hot air dryers.

Referring now to the drawings and to figure 1a, a fire protection system 10 according to an embodiment of the present invention is illustrated in the inactivated state, in which no fire has been detected.

In this example an enclosure 4 is mounted on a wall behind and above a stove 5, for extinguishing a potential fire on the hob. As illustrated more detailed in fig. 2a, the enclosure comprises a fire blanket 1 , an airbag 2 and an inflator device 3.

The fire blanket 1 may be of any suitable, fire resistant material, and be adapted to quench a fire. Fire blankets of this type are generally known in the art. The inflator device 3 is arranged to inflate the airbag. The airbag 2 is also preferably made of a fire resistant material, and is arranged to be quickly inflatable and arranged in relation to the fire blanket in such a way that when it is inflated, the airbag will cause the fire blanket to cover the fire hazardous area, and thus extinguish any fire. Examples of an airbag 2 and an inflator device 3 will be described in more detail below. A fire detector 6, such as a smoke detector, an infrared sensor or a safety fuse can be mounted at a suitable location, such as above the hob, which detector is adapted to detect a fire on the hob, and send a signal to the inflator device 3 in case of fire. Turning to figure 1 b, the fire protection system 10 of the present invention is illustrated in the activated state, in which a fire has been detected. In more detail, the fire detector 6 detects a fire and causes inflation of the airbag 2.

In this example, the airbag 2 pushes a door 8 of the enclosure 4 open when it inflates. As can be seen, the airbag 2 inflates essentially horizontally from the wall, and unfolds the fire blanket 1 over the hob as it inflates. Here, the airbag 2 has the form of a grid in the inflated form, having 2 horizontal inflatable channels 9a-b and 2 vertical inflatable channels 11 a-b.

Hence, the airbag 2 inflates efficiently, and by that efficiency in combination with the shape of the airbag 2 and how the airbag 2 is arranged in relation to the fire blanket 1 before inflation, the fire blanket 1 is accurately guided to cover the fire on the hob.

Figure 2a illustrates an example of how the different parts of the fire protection system 10 may be arranged in the enclosure 4, hence in the uninflated state, in which no fire is detected and the system is inactive.

In the illustrated embodiment the enclosure 4 has two compartments

12, 13 wherein a folding 18 of the fire blanket 1 and the airbag 2 is arranged in a first compartment 12 and the inflator device 3 in a second compartment

13. Here, the second compartment 13 is arranged above the first compartment 12. Alternatively, it is arranged behind the first compartment 12, or anywhere where it does not prevent the airbag 2 from inflating and unfold the fire blanket 1.

The illustrated inflator device 3 here comprises a pressurized gas cartridge 15, such as a carbon dioxide cartridge, and a puncturing device 20. In figure 2b, an example of the fire protection system in the activated state is illustrated, in which the puncturing device 20 has punctured the carbon dioxide cartridge 15, due to a detected fire, whereby the gas inflates the inflatable channels 9a-b, 11 a-b of the airbag 2. Here, the airbag 2 has two nozzles 17a-b, both connecting the carbon dioxide cartridge 15 of the inflator device 3 to the airbag 2, so that the inflator device 3 may inflate the airbag 2 evenly from two directions. Here, the enclosure 4 has three magnetic catches 14a-c, allowing for a pressure on the door 8 that is caused by the airbag 2 after having inflated to a certain level to open the door 8.

In figure 3, the puncturing device 20 is further illustrated. The puncturing device 20 here comprises a puncturing pin 21 , attached to an actuator body 28 which runs in a sleeve 26 and is spring loaded by means of a coil spring 25. The pin 21 is secured in a resting position by a catch 22 or any other abutment, acting on the actuator body 28. The catch 22 may be released by a release lever 24.

In the illustrated case, the catch 22 is formed on a stub 27 which is rotatable around an axis extending in a direction transverse the direction of movement of the puncturing pin 21. The catch 22 is thus movable between a first position, in which the catch 22 engages a recess 23 in the puncturing pin 21 , and a second position, in which the catch 22 is out of engagement with the recess 23. In the illustrated case, the recess 23 is a hole in a flat end portion of the actuator body 28. The release lever 24 is fixedly attached to the stub 27, and can be used to exert a moment on the stub, to rotate it to move the catch 22 between the first and second position.

In case of fire, a signal from the fire detector activates an actuator (not shown) that causes a force to act on the lever 24, so that the stub 27 rotates and the catch 22 is brought out of engagement with the recess 23 of the actuator body 23, which results in that the puncturing pin 21 is released from its resting position. A relatively low force on the lever 24, for example 10 N, is enough to rotate the catch 22 by means of the lever 24. That is, a relatively weak force is enough to prevent the puncturing pin 21 from releasing. The spring 25, on the other hand, causes a much stronger force, such as 430 N, to act on the actuator body 28, and the puncturing pin 21 will thus be pushed against the carbon dioxide cartridge with a force sufficient to puncture the cartridge. As already mention, in relation to fig. 2, the puncturing pin 21 punctures the carbon dioxide cartridge, whereby the gas inflates the airbag. Turning now to Fig. 4, an example of a folding of a fire blanket 1 formed as a square and an airbag 2 is illustrated. The fire blanket 1 may for example be folded between the stove and the airbag 2. However, it may be advantageous to fold the fire blanket 1 and the airbag 2 together like in the illustrated example. Here, the airbag has two horizontal channels 9a-b and two vertical channels 11a-b, wherein two locations for inflation 17a-b are arranged at one end of the vertical channels 11 a-b.

In a first step, 401 , the airbag 2 is arranged on top of the fire blanket 1. Second, in step 402, two opposite sides of the square fire blanket 1 are folded with both ends of the horizontal channels 9a-b. The sides are folded a plurality of times, for example four times, until each folding cover the one of the vertical channels 11 a-b of the fire blanket 1 it first meet. Hence two rolls are formed, wherein the fire blanket 1 forms the outer layer of each roll. In step 403, the remaining border without locations for inflation is folded, or rolled, a plurality of times, for example five times, until the folding covers the first horizontal channel 9a-b that it meets.

Finally, in step 404, the airbag and the fire blanket folding 18 is further accordion folded a plurality of times, for example four times, between the side where the locations for inflation 17a-b are arranged and the opposite side, obtaining a compact folding, which is illustrated in step 405. The front side 30, of the folding illustrated in step 405 is adapted to be arranged toward the inner wall of the enclosure 4.

The person skilled in the art realizes that the present invention is not limited to the preferred embodiments. For example the airbag may have any suitable shape, the inflatable channels may be of any suitable number, the airbag may be inflated by other means known in the art, and the folding may be performed in various ways yet being arranged to efficiently extinguish a fire.

Such and other obvious modifications must be considered to be within the scope of the present invention, as it is defined by the appended claims. It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting to the claim. The word "comprising" does not exclude the presence of other elements or steps than those listed in the claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. Further, a single unit may perform the functions of several means recited in the claims.