Field of the Invention The present invention relates to a fire barrier, which is arranged adjacent to a window opening formed in a vertical wall.

. Background Art In recent years, glazing of balconies arranged one above the other in multi-storey buildings has become in- creasingly common as a way to provide an extra room or, in any case, a more usable balcony space for the inhabitants of each apartment. It has been found that the risk of fires in glazed-in balconies is greater than in not glazed-in balconies, and new fire protection regulations have been developed to reduce the risk of a possible fire in a glazed-in balcony spreading to a balcony located above it.

Summary of the Invention The object of the present invention is to provide a fire barrier at a window opening, which barrier is easy to manufacture and easy to mount adjacent to the window opening and which provides a well-working fire spread protection in accordance with the relevant fire protection regulations.

According to the present invention, this object is achieved by a fire barrier, which is of the type stated by way of introduction and which is characterised in that it consists of a sheet-metal element, which at one side edge is pivotally suspended above the window opening about an essentially horizontal axis and which is pivotable between an essentially vertical shielding position, in which it at least partially covers the window opening, and an essen- tially horizontal initial position, in which it is kept in position by a heat and/or smoke detecting releasing means, which is adapted to release the sheet-metal element in the

event of a fire, so that the latter swings down by its own weight to the essentially vertical shielding position.

In a preferred embodiment, the sheet-metal element is formed of two separate, essentially rectangular sheet-metal sections, one of which at one edge is pivotally suspended above the window opening about said horizontal axis and, at an opposite side edge, connected to the other sheet-metal section at one side edge thereof and pivotable about a second horizontal axis, the two sheet-metal sections being pivotable relative to one another between a folded position, in which they are located on top of one another and which they take when the sheet-metal element is in the initial position, and an unfolded position, which they take when the sheet-metal element is in the shielding position.

Brief Description of the Drawings The invention will now be described in more detail with reference to the accompanying drawings.

Fig. 1 is a schematic view showing parts of a glazed- in balcony, in connection with which a fire barrier according to the invention is mounted, the fire barrier being shown in an initial position.

Fig. 2 corresponds to Fig. 1, but shows the fire barrier in a shielding position.

Description of a Preferred Embodiment The drawings show only parts of a glazed-in balcony.

Thus, a portion of a roof slab 1 is shown, which at the same time forms the floor slab of a balcony located above, as well as a portion of a glazing with a vertical, front wall 2 and window pane 4 mounted in a window opening 3 therein. The window pane 4 is here a door, which is dis- placeable back and forth perpendicularly to the drawing plane.

A bar 5 extends along the whole balcony in the area of the inner corner formed between the front wall 2 and the roof slab 1. The bar 5 is attached to the roof slab 1 at its ends by means of attaching means (not shown). As

described in more detail below, the bar 5 forms a pivot shaft.

The glazed-in balcony is provided with a fire barrier 6 according to the invention. The fire barrier 6 is formed of two essentially rectangular sheet-metal sections 7 and 8. The two sheet-metal sections 7 and 8 are profiled and their shape will now be described as seen in the essen- tially horizontal position in which they are located when the fire barrier 6 is in an essentially horizontal initial position (Fig. 1).

The sheet-metal section 7 has an upper, horizontal plateau portion 7a, which extends across the major part of the width of the sheet-metal section 7, two downwardly sloping portions 7b and 7c on both sides of the plateau portion 7a, and two lower, horizontal portions 7d and 7e, which are connected to the sloping portion respectively 7b and 7c. The sheet-metal section 7 has at the side edge that is closest to the wall 2 and parallel thereto a hook- shaped, bent end portion 7f, by means of which it is mounted on the bar 5 in a pivoting manner. The sheet-metal section 7 has at the opposite side edge an L-shaped, upwardly bent end portion 7g which, together with the portion 7e, forms a pocket. The sheet-metal section 7 is pivotable between the essentially horizontal initial position shown in Fig. 1 and an essentially vertical shielding position (Fig. 2).

The sheet-metal section 8 has an upper, horizontal portion 8a, which extends across the major part of the width of the sheet-metal section 8 and has essentially the same extent as the plateau portion 7a of the sheet-metal section 7, a downwardly sloping portion 8b, which is lo- cated to the right (Fig. 1) of the portion 8a and con- nected thereto and which has essentially the same extent as the downwardly sloping portion 7c of the sheet-metal section 7, and a lower, essentially horizontal portion 8c, which is connected to the portion 8b. The sheet-metal sec- tion 8 has at the side edge that is furthest away from the

wall 2 and parallel thereto a hook-shaped, upwardly bent end portion 8d, which is located in the pocket formed by the horizontal portion 7e of the sheet-metal section 7 and the L-shaped, upwardly bent end portion 7g. This allows the sheet-metal section 8 to be pivoted about a pivot axis defined by the two end portions 7g and 8d and parallel to the bar 5. The two sheet-metal sections 7 and 8 are thus pivotable relative to one another between a folded posi- tion, in which they are located on top of one another and which they take when the fire barrier 6 is in the initial position (Fig. 1), and an unfolded position, in which they are in alignment with one another and which they take when the fire barrier 6 is in the shielding position (Fig. 2).

When the fire barrier 6 is in the initial position, the two sheet-metal sections 7 and 8 are in their folded position, as described above, in which they extend parallel to the roof slab 1 and in proximity thereto (Fig. 1). The fire barrier 6 is kept in this position by means of a heat and/or smoke detecting releasing means 9 which, in the embodiment shown, is a fuse arranged between the upwardly bent end portion 7g of the sheet-metal section and the roof slab 1.

In the event of a fire on the glazed-in balcony, the releasing means 9 is activated and releases the fire barrier 6, so that the sheet-metal section 7 by its own weight and that of the sheet-metal section 8 swings down to a vertical position, following which the sheet-metal section 8, whose centre of gravity is located, as a result of the profiling described above, to the right (Fig. 2) of the pivot axis defined by the two upwardly bent end portions 7g and 8d, is pivoted to the unfolded position.

In the shielding position of the fire barrier 6, the two sheet-metal sections 7 and 8 are in vertical alignment with one another and cover the window opening 3.

The fire barrier 6 described above can be modified in various ways within the scope of the appended claims. In an alternative embodiment, the pivot shaft formed by the

bar 5 in the embodiment described and shown is formed by a sheet-metal strip, which is attached to the roof slab 1 and bent to form, together with the hook-shaped, bent end portion 7f of the sheet-metal section 7, a joint corre- sponding to the joint formed by the upwardly bent end por- tions 7g and 8d. It will be appreciated that the fire bar- rier according to the invention can be used in connection with not only glazed-in balconies but other types of window openings as well.