GB2118231A - A fire-protective door panel - Google Patents

Abstract

A fire-protective door panel comprises a shallow box 3 formed by two metal sheets 1, 2 of which lower horizontal edge strips 4, 5 are angled in U-shaped manner in cross-section and are connected to one another by a weld seam 8 whilst edge strips 4', 5' are folded to form a rabbet. Arranged inside the box 3 is a stiffening frame 9 made of gypsum which encloses an insert or core 16 of insulating material. Intumescent strips 17 may be provided. <IMAGE>

Description

SPECIFICATION A fire-protective closure for an opening in a building This invention relates to a fire-protective closure or seal for an opening in a building comprising a shallow box which encloses a stiffening frame and an insulating material core and which is formed by two metal sheets or panels which are connected to one another by way of bent edge strips.

In the known fire-protective closures of this kind, the constructional formation of the stiffening frame and its stable positioning inside the seal is bound up with particular expenditure, so that the frame, more particularly in the event of fire, may retain its stiffening function in spite of high thermal stressing of the closure.

A fire-protective closure, known from German Patent Specification No. 22 57 862, for a wall opening or a ceiling opening, consists of a multi-layer closure sheet which has a stiffening frame with an internal framework, consisting of metal sections, in which inserts of insulating material are arranged and which is surrounded, at a spacing from the metal sections, by fairing plates or covering panels which are of box-like form. Provided in this arrangement, on both sides, between the fairing plates and the stiffening frame, and butting against the fairing plates, are respective layers of fire-protective plates, these being arranged in such a way that free interspaces remain between them and the inserts of insulating material.The fairing plates are also covered at the front edge of the closure sheet on the inside with fire-protective plates and are arranged, together with the fire-protective plates, on all sides, at a spacing from the stiffening frame with the internal framework.

The connection of the stiffening frame to the fairing plates is effected by way of thin webs.

In this known fire-protective closure, the stiffening frame, with the internal framework of metal sections, is well protected against the action of heat by an additional sheathing with fire-protective plates; moreover sufficient intermediate space is left for the fire-protective plates, which effervesce under the action of heat, that deformation of the fairing plates as a result of the increase in volume of the fireprotective plates, is avoided. Furthermore, the webs which connect the fairing plates to the stiffening frame are not arranged in alignment but are laterally staggered on the one side of the closure sheet, relative to the webs on the other side thereof, so that also after a long period of being subjected to heat, strikingthrough or burning-through, of the fire as a result of the good conductivity of the webs, is hindered.

Because of this design, fire-resistance of exceptionally long duration is achieveable with the known fire-protective closure. The expenditure on material and fabrication bound up with this design is, however, very considerable.

The problem underlying the invention is to provide a fire-protective closure of the kind referred to at the introduction hereto, which, with simple means, is simple to produce and is nevertheless distinguished by a fire-resistive capacity which is comparable with the previously-known fire-protective closure.

Starting from a fire-protective seal of the kind referred at the beginning hereof, to solve the problem posed it is proposed that the stiffening frame should consist of gypsum, for example of pearl gypsum (GKP in accordance with DIN 18180).

Because of the presence of the stiffening frame made of Gypsum, the box, formed from fairing plates, of the fire-protective closure in accordance with the invention has very good stability, so far as its shape is concerned.

Tests have proved that the closure retains its shape almost unchanged even when subjected to intensive heat on one side only for periods in excess of the rated resistance times. The low heat conductivity of the stiffening frame, in the closure according to the invention, which is of gypsum, delays heat transmission from the heat-impinged side of the closure to the opposite side of the closure, so that the risk of breaking-through of fire from a room separated by the fire-protective closure into an adjacent room is minimised. Also the inherent stiffness of the frame is fully maintained even in the event of being subjected to intense heat in excess of the required resistance time.

In accordance with a development of the closure of the invention, the elements of the stiffening frame are formed from gypsum profiles or sections which are connected to one another.

With this development of the closure of the invention, frame elements having different cross-sectional dimensions can be built up from gypsum section which correspond in their cross-sectional dimensions, depending on the required thickness of the stiffening frame, by a selected number of the sections being assembled into the elements.

Preferably the gypsum sections for the construction of a frame element are composed of gypsum strips which are rectangular in crosssection and which are layered one on the other.

Sufficient for the production of stiffening frames of different geometry is, therefore, an adequate amount of uniform gypsum strips which can be simply assembled into piles or packs of any desired dimensions and, cut to appropriate length, are usable as frame elements.

The stability of the stiffening frame can, in accordance with a further development of the closure of the invention, additionally be im proved in that the gypsum strips are layered in a direction perpendicular to the plane of the closure.

If one layers the gypsum strips in the direction perpendicular to the plane of the closure, the axis of each gypsum strip, which has the greatest resistance moment, corresponds in direction with the direction of the plane of the closure. In this way, the maximum forces, occurring at the stiffening frame as a result of heat expansions and ensuing in the direction of the plane of the closure, of the fairing plates are best taken into consideration.

In accordance with a further development of the invention, the connection of the individual frame elements into a stiffening frame is preferably so effected that one end of a gypsum strip of one layer overlaps the end of one gypsum strip of an adjacent layer.

This overlapping of the gypsum strips permits strong and stable interdigitation of the ends of the frame members without the need for providing additional shaped pieces to act as connecting means as may be necessary for example in the case of an obtuse or flush or butt arrangement of the frame elements to one another.

In some cases it may also be advantageous to form the stiffening frame from frame layers which are connected to one another and which are separated out from gypsum plates.

Stiffening frames constructed in this way are distinguished by particularly homogeneous properties, since all the elements of the stiffening frame consist, layerwise, of the same gypsum plate.

So that the connection of the sheet panels, more particularly also along the horizontal lower edge of the door or closure leaf, where this is plain or flush in design to ensure necessary freedom of movement (in other words it does not possess a rebate or shoulder so that a part thereof extends beyond the door or closure opening cross-section), will withstand any excess pressure that is to be expected in the interior of the space closed by the door or closure, in the event of fire and also that no gases can emerge by way of this region, a further development of the invention provides for the fact that, at least in this region, the edge strips of the sheet panels are angled in U-shaped manner in cross-section and the sheet panels are connected together there by way of juxtaposed limbs of the edge strips which are arranged in mirror-inverted manner with respect to one another.

In the fire-protective closure in accordance with this development of the invention, the limbs of the edge strips, arranged in mirrorinverted manner with respect to one another, of the sheet panels can be connected together by way of the edge region, most endangered in the absence of a stop, of the closure in an equally secure manner as by a mutually hooked rabbet connection. As a result of the angling of the edge strips in U-shaped manner in cross-section, they are afforded a bending stiffness which is higher in comparison with rabbeted edge strips. If then the edge strips, which are in themselves already very bendingresistant, additionally are securely connected to one another, the bending-resistance of the box edge as a whole is increased considerably.

In accordance with a further development of the invention, the juxtaposed limbs of the edge strips are let into a groove, defined by a recess in each of two frame halves forming the stiffening frame, in the stiffening frame and connected to one another by a frontallyarranged weld seam.

For the stable connection of the juxtaposed limbs it is completely adequate if thus the limbs are connected to one another by a frontally arranged weld seam. If then an excess pressure occurs in the interior of the box, the limbs let into the groove of the stiffening frame are not themselves directly affected thereby. Insofar as the excess pressure acts on the relevant end side of the box, this is given a considerable stiffening by the limbs. The weld seam connecting the limbs frontally to one another, even with comparatively slight dimensioning, is capable of withstanding the tensile force resulting from the excess pressure in the box. Through the arrangement of the limbs in the groove of the stiffening frame, the limbs are given an additional coherence, whereby gaping apart of the limbs if precluded.

The construction of the stiffening frame from two frame halves, in production technique respects, has the advantage that, for example, one sheet panel each is equipped with one frame half, with at least one edge strip each of the sheet panel is angled about end faces of the frame half. As soon as the angling to achieve the U-shaped cross-section of the edge strip is completed, two frame halves, already clad with the sheet panels, can be assembled in a simple manner into a door leaf or closure and be securely connected along the underedge of the door leaf or closure by a weld seam to the juxtaposed limbs, whilst the connection of the sheet panels along the remaining edges can be effected in the conventional manner by an appropriate rabbet deformation or fold of the edge strips.

In order to protect the transitional region between the insert of insulating material and the stiffening frame in such a way that, even when the insulating material insert is arranged with a clearance inside the stiffening frame, burning-through in the transitional region between the insert of insulating material and the stiffening frame is precluded, a development of the invention provides for the strips of sodium silicate (which are provided with a moisture-tight sheathing and which effervesce under the effect of heat) are arranged between the end surfaces of the insert of insulating material and the surfaces of the stiffening frame which confront the same.

The use and arrangement, in the closure according to the invention, of the strips of sodium silicate leads, in the event of fire, to the fact that these effervesce under the action of heat and thereby fill up completely any free space possibly existing between the end surfaces of the insert of insulating material and the frame surfaces facing them. The increase in volume that can be achieved, under the effect of heat, with commercially-available strips of sodium silicate will result in complete filling of the intermediate space even when the insert of insulating material is arranged with considerable clearance inside the stiffening frame.

Finally, another development of the closure of the invention additionally provides for the fact that the width, aligned perpendicular to the plane of the door leaf or closure, of the strips of sodium silicate corresponds to the thickness of the insert of insulating material.

As a result of this development, the construction of the door leaf or closure can be accomplished in a simple manner in that the stiffening frame or the frame half respectively is placed on a horizontally-arranged fairing or cladding plate and then arranged inside the stiffening frame or the frame half respectively is the insert of insulating material which is, in its length-wise and width-wise dimensions, kept slightly smaller than the clear length and width of the stiffening frame. The strips of sodium silicate can then be inserted perpendicularly to the plane of the door leaf or closure, without the risk of an unintentional displacement existing, after the second fairing plate is placed on and both fairing plates are connected securely to one another.

Any lack of resistance of the strips of sodium silicate to moisture is countered by moisture-tight sheathing of said strips of sodium silicate. Since the sheathing of the strips of sodium silicate inside the door leaf or closure is not exposed to any appreciable mechanical stresses, it is sufficient if the sheathing consists, for example, of a thin metal foil which also tightly encloses the ends of the strips of sodium silicate. It naturally lies within the scope of the invention for the sheathing to be made, for example, from polyvinylchloride tubing which is sealed at its ends.

One exemplified embodiment of a fire-protective closure in accordance with the invention is illustrated schematically and in crosssection in the single figure of the accompanying drawing.

In the drawing, sheet panels 1 and 2 form a flat or shallow box 3. For this, a horizontal lower edge strip 4 of the sheet panel 1 and a similar edge strip 5 of the sheet panel 2 are angled or folded in U-shaped manner in crosssection. The sheet panels 1 and 2 are thereby so arranged that a limb 6 of the edge strip 4 and a limb 7 of the edge strip 5 lie laterally opposite one another. By way of a weld seam 8, the sheet panels 1 and 2 are securely connected to one another on the end face formed by the edge strips 4 and 5. The vertical edge strips (not shown) of the sheet panels 1 and 2 are connected to one another by a conventional rabbet or fold formation in the same way as the horizontal upper edge strips 4' and 5' of the sheet panels 1 and 2.

In the interior of the thus-formed shallow box 3 there is a stiffening frame 9 which consists of two frames halves 10 and 11.

While the angled edge strip 4 embraces the frame half 10, the frame half 11 is embraced by the angled edge strip 5. Each frame half 10 and 11 consists of two frame layers 12 or 13 respectively, which can be punched from appropriately dimensioned gypsum plates.

The respective frame layers 12 and 13 turned towards the angled limbs 6 and 7 have recesses 14 and 15 respectively, so that the limb 6 and 7 is embedded in the respective frame halves 10 and 11.

Arranged inside the hollow space, defined by the stiffening frame 9, of the shallow box 3 is an insert 16 of insulating material between whose end faces and the frame surfaces lying opposite thereto there are strips 17 of sodium silicate which effervesce under the action of heat and which are enclosed by a sheathing 18 in a moisture-tight manner.

Claims (11)

1. A fire-protective closure or seal for an opening in a building, comprising a flat or shallow box which encloses a stiffening frame and an insulating material core or insert, and which is formed by two metal sheets which are connected together by way of bent edge strips characterised in that the stiffening frame consists of gypsum.

2. A fire-protective closure or seal as claimed in claim 1, characterised in that elements of the stiffening frame are formed of gypsum profiles which are connected to one another.

3. A fire-protective closure or seal as claimed in claim 2, characterised in that the gypsum profiles are composed of gypsum strips which are rectangular in cross-section and which are layered on one another.

4. A fire-protective closure or seal as claimed in claim 2 or 3, characterised in that the gypsum strips are layered in a direction perpendicular to the plane of the closure or seal.

5. A fire-protective closure or seal as claimed in claim 2, 3 or 4, characterised in that one end of a gypsum strip of one layer overlaps the end of a gypsum strip of a neighbouring layer.

6. A fire-protective closure or seal as claimed in claim 1, characterised in that the stiffening frame consists of layers which are connected to one another and which are separated out from gypsum plates.

7. A fire-protective closure or seal as claimed in any preceding claim characterised in that at least one edge strip each of the metal sheets is angled in U-shaped configuration in cross-section and the metal sheets are connected to one another by way of juxtaposed limbs of the edge strips which are arranged in mirror-inverted manner with respect to one another.

8. A fire-protectiveclosure or seal as claimed in claim 7, characterised in that the juxtaposed limbs are let into a groove, formed by a recess in each of two frame halves forming the stiffening frame and are connected to one another by a frontally-arranged weld seam.

9. A fire-protective closure or seal as claimed in any preceding claim characterised in that sodium silicate strips, provided with a moisture-tight sheathing and which effervesce under the action of heat, are arranged between the end surfaces of the insulating material insert and surfaces of the stiffening frame which lie opposite thereto.

10. A fire-protective closure or seal as claimed in claim 9, characterised in that the width, perpendicular to the plane of the closure or seal, of the sodium silicate strip corresponds to the thickness of the insulating material insert.

11. A fire-protective closure or seal substantially as hereinbefore described with reference to and as illustrated in the accompanying drawing.