GB2203476A

GB2203476A - A fire-barrier door

Info

Publication number: GB2203476A
Application number: GB08805965A
Authority: GB
Inventors: Theo Schroders
Original assignee: Individual
Current assignee: Individual
Priority date: 1987-04-15
Filing date: 1988-03-14
Publication date: 1988-10-19
Also published as: PT87249B; ATA53888A; ES2006850A6; DE3712737A1; BE1001144A5; IN169900B; PT87249A; NL8800829A; FR2614066A1; GB8805965D0; AT391523B; HUT46389A; DE3712737C2; CH677952A5

Description

1 EH100388 1 A FIRE-BARRIER DOOR M1 p 2203,4I,u This invention relates fo

a fire-protection or "f'irebarrier door having a door leaf consisting of sheet-metal panels which are connected together to form a flat shallow box. - Arranged therein are a stiffening frame surrounding an insulatingmaterial insert. The stiffening frame is composed of fillets which are at least partially covered with sheet-metal strips, which are, in the same way as the fillets, aligned perpendicularly to the plane of the door leaf.

A fire-barrier door having such a door leaf is known from German Patent Specification DE-OS 24 49 232, in which respect the fillets which form the stiffening frame consists of asbestos -silicate strips, between which thin sheet-metal strips are arranged. For the known door leaf it is asserted as an advantage that the frame is considerably stiffened perpendicularly to the door plane, without a noticeable increase in weight occuring. Also the asbestos-silicate strips lying between the sheet-metal strips could as a result of this reinforcement be considerably thicker, so that less strips have to be connected together to form a frame fillet.

However, the use of thin sheet-metal strips between the asbestos-silicate strips restricts the stiffening of the frame to the perpendicular direction with regard to the door plane. For unrestricted or universal frame.stiffening EH100388 2 stronger reinforcement is required. If, for this purpose, the thin sheet-metal strips were to be replaced by thicker sheet-metal strips, each of these would constitute an effective heat bridge from one side of the door leaf to the other, and this obviously would not be acceptable in the case of a fire- barrier door. Even with the thin metal sheets used between the asbestos - silicate strips in the known door both sides of the stiffening frame have to be covered with cover plates made of asbestos silicate to avoid creation of heat bridges. As a result of the presence of these cover plates, even the stiffening of the frame in the direction perpendicular to the plane of the door leaf cannot take full effect on the stiffening of the door leaf. Moreover, it seems to be necessary to fasten the cover plates to the frame, by tacks or screws whereby heat bridges which cannot be eliminated by the cover plates, may again arise.

In the case of the known fire-barrier door, heat bridges from one side of the door leaf to the other have a particularly disadvantageous effect, because, as would be expected, the asbestos-silicate material has an insulating effect, not a cooling effect.

Irrespective of the aforedescribed disadvantage, the processing of asbestos -silicate material is to a high degree injurious to health, since unavoidable loosening of asbestos fibre particles occurs, which fibres can be breathed into the lungs of operatives and cause lung 1 V, 0 EH100388 3 hardening.

A fire-protective closure for building apertures which includes a stiffening frame is also already known from German Patent Specification DE-PS 33 05 639. This is composed of frame fillets which in each case consist of st-rips of gypsum of rectangular cross-section connected together. In order not to have to rely on connection means which form heat bridges, the strips of gypsum, which are layered in a direction perpendicular to the closure plane, are glued together. In the event of fire the gluing between the first and second strips of gypsum is affected, whereas all the subsequent glued connections remain unimpaired. In this way the frame stability and thus also the stability of the door leaf as a whole can be maintained.

Although the frame formed solely from strips of gypsum glued together has excellent fire-resistance properties it has only a limited breaking strength and. in particular, comparitively sensitive to impact stresses. The latter is problematic since doors are frequently subject to stress by being improperly pushed open or slammed shut with the aid of objects.

The object of Ahe invention is to improve a firebarrier door of the kind described at the beginning hereof in such a way that, whilst retaining its high fireresistance, the frame disposed inside the door leaf for stiffening purposes is given. by means which are simple to 1 EH100388 4 produce and which are just as simple to integrate, high strength not only perpendicularly to the p.lane of the door leaf, but also in the plane thereof.

This object is achieved in accordance with the invention in that in a fire-barrier door of the type described in the first paragraph hereto each sheet-metal strip is angled at least twice and in each case covers, at least partially, three side surfaces a fillet consisting of a material which contains an evaporable liquid.

As a result of the aforesaid twice angling of each sheet-metal strip a Ushaped profile is created which is flexurally stiff (i.e. resistant to bending) in both axes and between the limbs of which a fillet can be inserted, and, thus positioned kept largely free from bending stresses.

It has surprisingly been shown that the heat bridges formed through the sheet-metal strips, bent in a U-shaped manner, from the sheet-metal panel to sheet-metal panel right through the door-leaf box do not take effect in the event of a fire. This is attributed to the fact that the liquid evaporating in the meantime from the material of the fillets is sufficient to counter a rise in temperature of the sheet-metal strip particularly of its angled limbs.

In accordance with a development of the invention, as a result of which heat bridges formed by angled sheet-metal strips can be totally avoided, the limbs of each sheetmetal strip which is U-shaped in cross-section are of 0 1 EH100388 5 shorter dimension than. the width of the fillets, which preferably consist of sodium silicate.

The homogeneity of a frame limb composed of several fillets and sheetmetal strips can be improved in that, in accordance with a further development of the invention, neighbouring fillets of one frame limb are bordered by Ushaped sheet-metal strips which are directed towards one another (i.e. face in opposide directions).

However, the possibility also exists, in the case of frame limbs which are composed of more than two fillets, to insert only every alternate fillet into a U-shaped sheetmetal strip and to ensure the uniform construction of the frame limb in that sheet-metal strips which succeed one another at the spacing of a fillet are in turn arranged directed towards one another, i.e. facing in opposing directions.

In accordance with a further development of the invention, one sheetmetal strip may be angled in such a manner as to have a cross-section of meandering configurations and border at least two neighbouring fillets. This development has the advantage that to produce a frame limb only one sheet- metal strip of meandershaped profile and an appropriate number of fillets are necessary, in which respect the fillets are inserted, in perpendicular direction to the longitudinal extent of the door leaf, into pockets formed on both sides of the sheetmetal strip in order to complete the frame limb.

If EH100388 6 If heat bridges from one side of the door leaf to the other are also to be avoided in the case of sheet-metal strips of meander-shaped cross- section one sheet-metal strip can be angled so as to have meander limbs of different length and one group of fillets can be produced in one piece, e.g. from a sodium silicate casting, so as to enclose at least some of the limbs of the angled sheetmetal strip.

Four exemplified embodiments of a door leaf of a fire- barrier door in accordance with the invention are shown, in each case in cross-section, in the accompanying drawings, and the invention will be explained further by reference thereto.

In all of the exemplified embodiments the door leaf consists of two sheetmetal panels 1 and 2. the edge regions of which are, in the conventional manner, so angled that the panels I and 2 form a box and are held securely together around their edges by way of a folded joint (scarf joint 3) - The box is filled by an insulating-material insert 4 and a stiffening frame composed of four frame members or limbs.

In the embodiment shown in Fig. 1, each limb of the stiffening frame is formed from a sheet-metal strip 5 which is U-shaped in cross-section and a fillet 6 made of gypsum which is inserted therein. The limbs 7 of the Uprofile sheet-metal strip 5 are shorter than the width of the fillet 6, which is therefore not fully covered by the c Z.

i EH100388 7 sheet-metal strip 5 on two of its three covered sides.

Because the limbs 7 of the sheet-metal strip 5end prematurely, no additional heat bridges arise through the sheet-metal strip 5 In the embodiment shown in Fig. 2, each limb of the stiffening frame is formed from two sheet-metal strips 8, 9 both of which are U-shaped in cross-section and two fillets 6 which are inserted therein. The adjacent limbs 10 and 11 of the respective sheet-metal strips 8 and 9 are directed towards one another but are so shortened that the limb ends do not contact one another and to this extent heat bridges are avoided.

In the embodiment shown in Fig. 3, each limb of the stiffening frame is likewise formed from two sheet-metal strips 12 which are U-shaped in cross-section, but in this case in conjunction with three fillets 6. The two sheet metal strips 12 respectively border on three sides only the two fillets 6 arranged on the outside, whilst the fillet 6 which is arranged in the centre is covered on its two opposing sides by limbs 13 of the sheet-metal strips 12.

In the embodiment shown in Fig. 4, each limb of the stiffening frame is formed from a sheet-metal strip14 which is angled in manner as to have a cross-section of meandering configuration with limbs 15. 16 and 17 of different lengths. The sheet-metal strips 14 are integrated into a block 18 which is cast from gypsum.

Each stiffening frame can be fixed in. the intended 1 EH100388 8 position by angled pieces (not shown) which are fastened to the mutually facing sides of the sheet-metal panels 1 and 2, or by other known means. Such fixing is always advisable when the stiffening frame is composed of limbs which are not connected securely together, and all the more so in cases where each limb consists of several individual parts which are in other respects not connected securely together.

The ratio of the thickness of the sheet metal from which the sheet-metal strips are produced and the thickness of the fillets, produced for example from gypsum, amounts to at least 1:8, preferably 1:10 to 1:20. It has been shown that sheet-metal strips made from sheet-metal having a thickness of 0.8 mm can, in the event of fire, be preserved-from an excessive temperature rise if the fillets are produced from gypsum props having a thickness of 15 mm.

j v 11 A - -. 1.

Claims

EH100388 Claims

1. A fire-barrier door having a door leaf consisting of sheet-metal panels which are connected together to form a flat box, wherein a stiffening frame composed of fillets and an insulating-material insert are arranged, the fillets being at least partially covered with sheet-metal strips which, in the same way as the fillets. are aligned perpendicularly to the plane of the door leaf, characterised in that each sheet-metal strip is angled at least twice and in, each case covers, at least partially, three side surfaces a fillet consisting of a material which contains an evaporable liquid.

2. A fire-barrier door as claimed in claim 1, characterised in that each sheet-metal strip is U-shaped in cross-section and has limbs which are shorter in length than the width of the fillets.

3. A fire-barrier door as claimed in claim 1 or 2, characterised in that neighbouring fillets of a frame limb are bordered by U-shaped sheet-metal strips which are directed towards one another (i.e. face in opposite directions).

4. A fire-barrier door as claimed in claim 1, 2 or 3. characterised in that one sheet-metal strip is angled in such a manner as to have a crosssection of meandering configuration, and borders at least two neighbouring fillets.

5. A fire-barrier door as claimed in any preceding claim.

9 1 1 EH100388 10 characterised in that the fillets consist of sodium silicate.

6. A fire-barrier door as claimed in any preceding claim. characterised in that one sheet-metal strip is angled in such a manner as to have aeander limbs of different lengths and one group of fillets Is formed as a one piece block or casting which encloses at least some of the limbs of the angled sheet-metal strip.

7. A fire-barrier door as claimed in any preceding claim characterised in that the ratio of the thickness of the sheet metal from which the sheet-metal strips made to the thickness of the fillets amounts to at least 1:8.

8. A fire-barrier door as claimed in claim 7, characterised in that the ratio of the thickness of the sheet-metal from which the sheet-metal strips are made to the thickness of the fillets amounts to,from 1:10 to 1:20.

9. A fire-barrier door as claimbd in any preceding claim, characterised in that the sheet-metal strips are produced from sheet-metal having a thickness of 0.8 mal and the fillets are produced from gypsum props having P,nickness of 15 mm.

10. A fire-barrier door substantially as hereinbefore described with reference to Fig. 1, or Fig. 2. or Fig 3. or Fig. 4 of the accompanying drawing.

Published 1988 at The Patent Office, State House, 68!71 High Holborn. London WCIR 4TP. Further copies may be obtained from The Patent Oface, Sales Branch, St Mary Cray, Orpington, Kent BR5 3RD. Printed by Multiplex techniques ltd, St Mary Cray, Kent. Con. 1187.

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