The present invention relates to an arrangement for providing an improved fire insula¬ tion of e.g. a window having a sheet unit such as a glass pane, a thermopane or the like, whereby the sheet unit is arranged in a groove with a groove bottom, along which a fire swell¬ ing material is provided, whereby spacing elements are provided, wholly or partially covering the fire swelling material between the border of the sheet unit and the fire swelling material, said material expands its volume upon fire and thereby press the spacing elements against the border, whereby the sheet unit to a higher degree is fixed in the groove. In such structures, currently available on the market, a fire swelling material is arranged in a groove with groove bottom and groove sides, in order to provide an improved fire insula¬ tion of windows, doors, facades or the like, wherein sheet units such as glass panes, thermo- panes are arranged with the aid of spacing elements, which support and carry the sheet unit out of contact with the groove bottom. The spacing elements are about 30-120 mms long and about 2-20 mms thick and have about the same width as the sheet unit. Between the spacing elements there will accordingly be a free space between the groove bottom and the borders of the sheet unit, along the whole circumference. It is previously known to provide fire swelling material on the bottom groove in said space between the spacing elements. When there is a fire the volume of the fire swelling material will increase and fill up the space and this will to a certain extent delay further propagation of fire through the groove. Despite this the fire can propagate and destroy the groove bottom, so that the spacing elements no longer can perform their supporting and carrying function, whereby the pane material will fall out of its frame and there will be a fire breakthrough and further fire propagation. If the frame is made of wood, this course of events will take place even quicker. In order to remedy this problem, metal clips are used today, which are mounted at the borders of the sheet unit to support it. The clips are expensive to buy and the mounting thereof is time consuming, resulting in a too expensive structure. It is also time consuming to put the fire swelling material, which is manufactured in the form of bands, between the spacing elements in the groove, since it has to be cut and ap¬ plied piece by piece, which is a time and labour consuming procedure. Further, it will also be difficult to obtain the desired fit and avoid any gaps. One object of the present, invention is to eliminate the drawbacks existing with the above mentioned structures by letting the spacing element cover the fire swelling material, whereby it, in case of fire, will be pressed against the sheet unit so that it will be fixed in the groove. Thanks to the invention, an arrangement is now provided, which enhances the lire insu- Jation of a window, a door, a facade or the like, in which a sheet unit, such as a glass pane, is provided. According to the invention, the sheet unit is arranged in a groove, which has a groove bottom and two groove sides, one of which is formed by a glazing bead. The groove surrounds the borders of the sheet unit, extending along its circumference. The groove bottom has a fire swelling material, whereby the spacing element substantially covers the fire swell¬ ing material. The border of the sheet unit is carried and supported by the spacing elements, whereby the fire swelling material in case of a fire expands its volume and thereby press the whole of or parts of the spacing element against the border, whereby the sheet unit to a higher degree is fixed in the groove. In a preferred embodiment of the invention, the groove is made substantially of wood, whereby burnt material will form cavities, which are substituted by the fire swelling material, which also fills up the space between the spacing elements, whereby the spacing elements effectively support the borders of the sheet unit from the groove bottom surface. According to the invention, in an alternative embodiment of the invention, the fire swelling material can also be provided on the groove sides, when very high fire demands have to be met. In order to obtain a better fire resistance in the sheet unit in e.g. a window, it is comprised of a fire classed glass pane. Then the fire insulation can be further improved in the groove by lining substantially the whole groove bottom with the fire swelling material, whereby the glass pane is supported by a number of spacing elements against the groove bot¬ tom surface, whereby substantially all spacing elements in case of fire will be pressed against the borders. When fire demands are combined with demands of a good heat insulation the fire classed pane will be comprised in a thermopane. According to the invention, in the preferred embodiment, the fire swelling material will then be used in the form of an elongated body in the form of a band with a width substantially corresponding to the width of the groove bottom, which, as we know, is about 4 - 6 mms wider than the width of the sheet unit. This width implies that the thickness can be limited to about 1 - 2 mms, resulting in that very little fire protecting material is needed for obtaining the desired fire protection. If the demands on the fire protection are not too high, no fire swell¬ ing material is then needed on the sides of the groove, which then can be provided with much less expensive rubber profiles or joint bands. The fire swelling material is provided with self- adhering tape, which is provided on the broad side of the band, e.g. the lower side facing the groove bottom surface. Then the band will be easy to apply on the surface of the groove bot¬ tom. In another embodiment of the invention the fire swelling material is applied in a groove lot in the groove bottom, or is arranged in a spacing element slot in the spacing element. In iis way the tire swelling material and the spacing element do not add that much to the height, s it does without the slots. The greatest advantages with the invention will thus be that an nproved fire insulation is accomplished at a lower cost both concerning material and labour ost and also resulting in that standard type windows can be used instead of special windows i order to comply with increased fire demands. This might be accomplished without any aetal clips and without joints and fitting-in of the fire protection material between the spacing lements, which instead is placed around the whole groove. In most of the embodiments, no ire protective material is needed on the groove sides.

The invention will be described more in detail below in connection with a few preferred mbodiments and with reference to the accompanying drawings, in which fig. 1 shows a vertical cross-sectional view through a frame with a thermopane and a fire welling material at the bottom, fig. 2 shows a longitudinal cross-sectional through a part of a frame with a thermopane ind a fire swelling material at the bottom, fig. 3 shows an alternative embodiment compared to the one illustrated in fig. 1 and fig. 4 shows the same view as in fig. 2 of the alternative embodiment, when a fire has sroceeded for a certain time.

The figures 1 - 4 show a wooden frame 18, which has a sheet unit 1 in the form of a thermopane 3, consisting of three glass panes 2, one of which is a fire classed glass pane 21, which is supported by spacing elements 9. The sheet unit 1 is fixed in a groove 4 in the wooden frame 18. The groove 4 has a groove bottom 5 with a groove surface 7 and groove sides 11, whereby the groove side 11 is formed by a glazing bead 19. Rubber profiles 20 are placed on the groove sides in order to seal against wind and weather. The sheet unit 1 has borders 6 along its circumference. The groove bottom 5 is covered with a fire swelling mate¬ rial 8. The spacing element 9 covers the fire swelling material 8. Between the spacing ele¬ ments 9 and between the border 8 of the sheet unit 4 and the fire swelling material 8, respec¬ tively, there is an empty space 12. The fire swelling material 8 is manufactured as an elon¬ gated body in the form of a band 13 and has a self-adhering tape 14, which is applied on the broad side 15 of the band 13. In fig. 3 the fire swelling material 8 is shown applied in a groove slot 16 in the surface 7 of the groove bottom 5 and in the spacing element 9 in a spacing element slot 17. In fig. 4 the wooden frame 18 with its groove 4 is shown having been on fire for a cer¬ tain time. Cavities 10 have been formed in the wood by the fire and the fire swelling material 8 has replaced burnt-up wood and also filled up the space 12 between the spacing elements 9.