GB1591612A

GB1591612A - Device for resisting the spread of fire through an opening

Info

Publication number: GB1591612A
Application number: GB1672576A
Authority: GB
Original assignee: Dufaylite Developments Ltd
Current assignee: Dufaylite Developments Ltd
Priority date: 1977-07-22
Filing date: 1977-07-22
Publication date: 1981-06-24

Description

(54) DEVICE FOR RESISTING THE SPREAD OF FIRE THROUGH AN OPENING (71) We, DUFAYLITE DEVELOPMENTS LIMITED, a British Company, of Cromwell Road, St. Neots, Cambridgeshire, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement The present invention relates to structural honeycomb materials, and other structural cellular materials in which cells extending through the thickness direction of the material have their walls defined by strip material-e.g.

eggbox structures.

When their cell walls are coated with an intumescent material, which foams on heating to fill the cells, such materials have proved effective in fire barrier devices. In their unheated state they offer only a low resistance to airflow, and are therefore used in the form of grids to provide automatic closing of ventilation apertures or ducting to resist the spread of fire.

In accordance with the present invention there is provided a device for resisting the spread of fire through an opening which comprises a block of open cellular material having cell walls which extend through its thickness direction and are coated with an intumescent material adapted to swell and fill and block the cells under fire conditions and on at least one side of the block a normally retracted screen of non-flammable material arranged when actuated to extend to prevent or diminish gaseous flow through the block.

According to a convenient arrangement the screen is rolled in its retracted state.

Other arrangements are possible. For example, the screen may be folded, e.g. compactly zig-zag folded, in the retracted state.

When the screen is actuated, it obstructs the flow of smoke or other gaseous matter through the block. In some situations gases hot enough to cause the intumescent material to expand are prevented from reaching the block. In other situations an obstruction to the flow of hot gases is achieved more quickly than is possible by foaming of the intumescent material.

Given severe fire conditions, the screen prolongs the protection given by the block in that it slows the flow of hot gases through the block. By delaying the onset of sealing by the intumescent material, the time at which the intumescent material fails is correspondingly delayed. This effect tends to be enhanced by the screen, if it is on the side of the block remote from the fire, tending to slow gaseous flow through the block for a significant period before losing its structural integrity. In situations where the rate of gaseous flow is high, some of the intumescent material activated to an intermediate molten state can be blown out of an intumescent-coated block used alone. The screen tends to prevent this effect and, if it does occur, tends to collect the molten material upon its surface thereby holding it in a useful position.

It is preferred that the screen should be fitted on the downstream side of the block in circumstances where the direction of flow can be predicted as tends to be the case in ventilation ducting. Where the direction cannot be predicted it is desirable to have a pair of screens, one each side of the block or to have a single screen between two blocks. The latter arrangement is favoured where the space available for fitting is small. It may be employed, for example, for fitting within the thickness of a ventilation aperture in a fire resistant door. For neatness of finish, the assembly may be provided with a pair of louvred metal facings for fitting one on either side of the aperture and overlapping the opposite faces of the door around the aperture.

A screen on the downstream side of the block is protected from fire by the action of the block and its rise of temperature accordingly slowed. The failure temperature of the screen can be low compared with the steel screens which have been advocated previously for use alone. Conveniently the screen is formed of metal foil, aluminium foil being adequate in its properties. Other useful materials are synthetic resinous sheeting, e.g. polypropylene or polytetrafluoroethylene both of which have softening points which are high for thermoplastics.

knitted or woven materials, including nylon, may also be used. Especially favoured materials are knitted or woven materials laminated to a metal foil, glass fibre fabric laminated to alumium foil (used for the manufacture of fire resistant clothing) being especially attractive.

Shutters of metals of high temperature resistance are commonly used for closing apertures in fire-control applications. Such shutters when strongly heated, radiate heat from the side away from the fire at a rate sufficient to start fires in nearly combustible materials. This effect is avoided with the screen forming part of the present device which is not called-upon to act alone as a fire barrier.

Advantageously the screen is biassed to its extended state and is releasably held in its retracted state, e.g. by a heat-responsive device. Suitably, the heat-responsive device is a fusible linkage. Fusible linkages are known in such applications. They may be designed to operate at temperatures as low as 70"C, using Wood's metal or other lowmelting alloy or even a thermoplastic resin.

Normally, intumescent materials do not expand below 200"C. The screens of the invention perform a useful function if they are only resistant up to this temperature.

Irrespective of whether the screen is held retracted by a heat-responsive device, it is advantageously arranged to be released by a remote control arrangement, e.g.

involving a solenoid actuator or a mechanical arrangement actuated by a Bowden cable. The release may then be effected manually or may be responsive automatically, e.g. to à heat or smoke detector installed in the building, perhaps at a remote position.

In this way, the utility of the device of the invention is extended beyond the utility of the block alone in that the device may be employed to prevent the spread of- hot air or smoke as well as the spread of fire.

A convenient arrangement is to have the block and the screen or screens mounted together by a common framework.

In a preferred arrangement, the screen is held in its retracted state by a catch which is supported by an arm pivotally secured to a mounting and held against pivoted movement with respect to the mounting by a fusible material, the arrangement being such that when the fusible material melts, the arm pivots with respect to the mounting and allows the catch to move and release the screen.

Suitably the mounting is a lever held in position by a component movable to release the lever, arm and catch so that the screen may be released by movement of said component. This component may be a detent movable out of engagement with the lever by a mechanical release mechanism.

According to a simple and preferred construction, the arm is pivotally secured to the mounting by a pin which extends into or through a tubular bearing on the mounting and the fusible material fixes the pin in the bearing until fused. An advantage of this construction is that the tubular bearing may project into or through the block so that the shutter is actuated at an early stage.

In Patent Specification No. 1,500,912 we have described mounting arrangements for the block. Such arrangements are advantageously employed in a device according to the present invention.

The following description of a preferred embodiment of the device for mounting in an duct, in which description reference is made to the accompanying drawings, is given in order to illustrate the invention.

In the drawings: Fig. 1 shows the major components 1, 2, 3 & 4 of the device, separated but in the order in which they are assembled, Fig. 2 is a perspective of component 2, Fig. 3 is an elevation showing part of component 2 on an enlarged scale, Fig. 4 is a perspective of component 4, Fig. 5 is an elevation showing part of component 4 on an enlarged scale, Fig. 6 is an elevation of part of component 4 from the side opposite to that shown in Fig. 4, Fig. 7 is a cross section taken along line VIl-VIl of Fig. 6, Fig. 8 is a cross section taken along line VIII--VIII of Fig. 3 showing further details of part of component 2, and Fig. 9 shows one of a pair of spring arrangements forming part of component 2.

Referring to Fig. 1, component 1 is a piece of intumescent coated, resinated paper, honeycomb material which fits into component 2. Component 2 fits into componet 4. Roller blind 5 is carried by forks 6 of component 2 and, when released, is extended to close the air-throughway providing by the cells of the honeycomb material, by a pair of coil springs 7 fitted over pegs 8 projecting outwardly from each side of component 2 near the bottom thereof.

Component 2 has a frame 9 formed from sheet metal and shaped as shown. Its rear portion 10, for the reception of component 1, is divided from its front portion 11 by mesh screen 12 formed by welding- steel wires into position. These wires are welded together where they cross and are also welded to surrounding inner flange 13.

Blind 5, of glass fibre fabric laminated to aluminium foil which provides the outer face when the blind is rolled, is carried in rolled form by extensions 14 of a centre spindle which rest in forks 6. The outer end of blind 5 is provided with a metallic end piece 15 which projects beyond the width of the blind at both sides and is formed with depressions 16. These depressions receive hook members 17 (Fig. 9) at the ends of extended coil springs 7, the rollers 18 of which have central apertures 19 which are received by pegs 8.

Mechanism for holding the blind in the open position is fitted at position 20 of Fig. 2. Referring to Fig. 3, this mechanism has a detent 21 pivoted with the front portion 11 of the frame at position 22. This detent holds the complementary end 23 of a mounting arm 24, pivoted to the end of a bracket 125. To mounting arm 24 is secured an arm 25 in the manner shown in Fig. 8.

A tube 26 extends from mounting arm 24, which projects through mesh screen 12 and into the intumescent honeycomb component 1. Arm 25 is mounted upon a spindle 27 which extends through tube 26 and is secured thereto by soldering with metal 28 melting at 70"C. Spindle 27 is bent at 29 into contact with arm 25 and soldered thereto with the same metal.

Component 4 has a bracket 30 formed with an aperture 31 through which passes a catch 32, being retained against loss by wide end portions 33 of the catch. In Figs.

6 & 7 arm 34 of the bracket is shown hanging downwardly. However, when the device is set, arm 34 is retained in the horizontal position (36 in Fig. 7) by resting upon arm 25 at position 35 (Fig. 3). The end piece 15 of the blind engages arm 34 and is thereby restrained against the action of closing springs 7.

Under conditions of abnormally high temperature, metal 28 melts, Arm 25 pivots in the direction of arrow 37 (Fig. 3). The spring force on blind 5 swings arm 35 downwardly to disengage end piece 15 and allow the blind to close.

In the closed position, blind 5 lies between mesh 12 of component 2 and mesh 38 of component 4.

Referring to Fig. 7, component 4 is provided with strips of springy metal 39 (horizontal) and 40 (vertical) spot welded in position at their outer sides and projecting away from mesh 38 at their inner edges.

Strips 39, by their springiness, clamp the blind in its closed position to reduce gaseous leakage.

Detent 21 (Fig. 3) is loaded into the position shown by spring 41 carried on a rod 42 slidable in a bracket 43 and having an abutment 44. Pulling rod 42 disengages formation 23 from detent 21 allowing arm 25 to drop with arm 24, whilst solder 28 is solid, so that the blind is pulied by springs into the closed position for testing, on the nearby outbreak of fire, or under smoke conditions. Arrangements may be made for actuating rod 42 manually, mechanically, or electrically with a simple solenoid arrangement as required.

WHAT WE CLAIM IS: 1. A device for resisting the spread of fire through an opening which comprises a block of open cellular material having cell walls which extend through its thickness direction and are coated with an intumescent material adapted to swell and fill and block the cells under fire conditions and on at least one side of the block a normally retracted screen of non-flammable material arranged, when actuated, to extend to prevent or diminish gaseous flow through the block.

2. A device according to Claim 1 in which the screen is rolled in its retracted state.

3. A device according to either of Claims 1 or 2 in which the screen is formed of metal foil or of a knitted or woven material.

4. A device according to any one of Claims 1 to 3 in which the screen is formed of a knitted or woven material laminated to a metal foil.

5. A device according to Claim 4 in which the screen is formed of glass fibre fabric laminated to aluminium foil.

6. A device according to any of Claims 1 to 5 in which the screen is biassed to its actuated state and is releasably held in its retracted state.

7. A device according to Claim 6 in which the screen is-releasably held in its retracted state by a heat-responsive device.

8. A device according to Claim 7 in which the heat-responsive device is a fusible linkage.

9. A device according to Claim 6 in which the screen is held in its retracted state by a catch which is supported by an arm pivotally secured to a mounting and held against pivotal movement with respect to the mounting and allows the catch to move and release the screen.

10. A device according to Claim 9 in which the mounting is a lever held in position by a component movable to release the lever, arm and catch so that the screen may be released by movement of said component.

11. A device according to Claim 9 - in which the said component is a detent movable out of engagement with the lever by a mechanical release mechanism.

12. A device according to any one of Claims 9 to 11 in which the arm is pivotally secured to the mounting by a pin which extends into or through a tubular bearing on the mounting and the fusible material fixes the pin in the bearing until fused.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **.

aluminium foil which provides the outer face when the blind is rolled, is carried in rolled form by extensions 14 of a centre spindle which rest in forks 6. The outer end of blind 5 is provided with a metallic end piece 15 which projects beyond the width of the blind at both sides and is formed with depressions 16. These depressions receive hook members 17 (Fig. 9) at the ends of extended coil springs 7, the rollers 18 of which have central apertures 19 which are received by pegs 8.

Mechanism for holding the blind in the open position is fitted at position 20 of Fig. 2. Referring to Fig. 3, this mechanism has a detent 21 pivoted with the front portion 11 of the frame at position 22. This detent holds the complementary end 23 of a mounting arm 24, pivoted to the end of a bracket 125. To mounting arm 24 is secured an arm 25 in the manner shown in Fig. 8.

A tube 26 extends from mounting arm 24, which projects through mesh screen 12 and into the intumescent honeycomb component 1. Arm 25 is mounted upon a spindle 27 which extends through tube 26 and is secured thereto by soldering with metal 28 melting at 70"C. Spindle 27 is bent at 29 into contact with arm 25 and soldered thereto with the same metal.

Component 4 has a bracket 30 formed with an aperture 31 through which passes a catch 32, being retained against loss by wide end portions 33 of the catch. In Figs.

6 & 7 arm 34 of the bracket is shown hanging downwardly. However, when the device is set, arm 34 is retained in the horizontal position (36 in Fig. 7) by resting upon arm 25 at position 35 (Fig. 3). The end piece 15 of the blind engages arm 34 and is thereby restrained against the action of closing springs 7.

Under conditions of abnormally high temperature, metal 28 melts, Arm 25 pivots in the direction of arrow 37 (Fig. 3). The spring force on blind 5 swings arm 35 downwardly to disengage end piece 15 and allow the blind to close.

In the closed position, blind 5 lies between mesh 12 of component 2 and mesh 38 of component 4.

Referring to Fig. 7, component 4 is provided with strips of springy metal 39 (horizontal) and 40 (vertical) spot welded in position at their outer sides and projecting away from mesh 38 at their inner edges.

Strips 39, by their springiness, clamp the blind in its closed position to reduce gaseous leakage.

Detent 21 (Fig. 3) is loaded into the position shown by spring 41 carried on a rod 42 slidable in a bracket 43 and having an abutment 44. Pulling rod 42 disengages formation 23 from detent 21 allowing arm 25 to drop with arm 24, whilst solder 28 is solid, so that the blind is pulied by springs into the closed position for testing, on the nearby outbreak of fire, or under smoke conditions. Arrangements may be made for actuating rod 42 manually, mechanically, or electrically with a simple solenoid arrangement as required.

WHAT WE CLAIM IS: 1. A device for resisting the spread of fire through an opening which comprises a block of open cellular material having cell walls which extend through its thickness direction and are coated with an intumescent material adapted to swell and fill and block the cells under fire conditions and on at least one side of the block a normally retracted screen of non-flammable material arranged, when actuated, to extend to prevent or diminish gaseous flow through the block.
2. A device according to Claim 1 in which the screen is rolled in its retracted state.
3. A device according to either of Claims 1 or 2 in which the screen is formed of metal foil or of a knitted or woven material.
4. A device according to any one of Claims 1 to 3 in which the screen is formed of a knitted or woven material laminated to a metal foil.
5. A device according to Claim 4 in which the screen is formed of glass fibre fabric laminated to aluminium foil.
6. A device according to any of Claims 1 to 5 in which the screen is biassed to its actuated state and is releasably held in its retracted state.
7. A device according to Claim 6 in which the screen is-releasably held in its retracted state by a heat-responsive device.
8. A device according to Claim 7 in which the heat-responsive device is a fusible linkage.
9. A device according to Claim 6 in which the screen is held in its retracted state by a catch which is supported by an arm pivotally secured to a mounting and held against pivotal movement with respect to the mounting and allows the catch to move and release the screen.
10. A device according to Claim 9 in which the mounting is a lever held in position by a component movable to release the lever, arm and catch so that the screen may be released by movement of said component.
11. A device according to Claim 9 - in which the said component is a detent movable out of engagement with the lever by a mechanical release mechanism.
12. A device according to any one of Claims 9 to 11 in which the arm is pivotally secured to the mounting by a pin which extends into or through a tubular bearing on the mounting and the fusible material fixes the pin in the bearing until fused.
13. A device according to Claim 12 in

which the tubular bearing projects into or through the block.
14. A device according to any one of Claims 1 to 13 in which the screen is arranged to be actuated by a remote control arrangement.
15. A device according to any one of Claims 1 to 14 in which the screen and the block are mounted together by a common framework.
16. A device according to any one of Claims 1 to 15 in which the screen is positioned between a pair of blocks of said cellular material.
17. A device according to Claim 16 provided with a pair of louvred facings.
18. A device according to Claim 1, substantially as hereinbefore described and illustrated by reference to the accompanying drawings.