GB2244213A

GB2244213A - Fire-resistant device for protecting a partition unit

Info

Publication number: GB2244213A
Application number: GB9106520A
Authority: GB
Inventors: David Adie
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-03-27
Filing date: 1991-03-27
Publication date: 1991-11-27
Also published as: GB9006835D0; GB9106520D0

Abstract

A partition 1 having side panels 10 and 11 is substantially vertically disposed between a floor 2 and suspended ceiling 3 which forms a ceiling cavity 4 with an actual ceiling. The cavity 4 contains a fire-resistant device comprising a folded fire-resistant blanket 6 supported by the suspended ceiling 3. The blanket 6 has two edges connected respectively to weights 7 and 8, which are each supported in an upper position adjacent the top of the partition 1 by a respective temperature-responsive mechanism. Each mechanism preferably comprises a temperature responsive retaining pin 9, which may be made of a thermoplastics material which softens at elevated temperatures. Thus, upon softening or melting of the pin at elevated temperatures indicative of a fire, the weight is released thereby causing the blanket to drop down over the partition. In another embodiment, the fire-resistant device consists of a hinged panel assembly supported adjacent the ceiling or suspended ceiling by the temperature-responsive mechanism. <IMAGE>

Description

FIRE-RESISTANT DEVICE FOR PROTECTING A PARTITION UNIT The present invention relates to a fire-resistant device for protecting partition units, in particular glazed or partially glazed units.

Partitioning systems are commonly used to divide space, such as in offices, with each partitioning unit being solid, or wholly or partly glazed. In the event of a fire, the glazed units are significantly less resistant to the advance of a fire than solid units because ordinary glass is prone to shattering due to the intense heat, thus enabling a fire to spread quickly between partitioned areas. In order to increase the protection offered by a partition it is desirable to improve the fire-resistant properties of the glazed portion of a partition unit as well as the partition system as a whole. To this effect various types of fire-resistant glass have been devised, for example Georgian wired glass which contains a wire mesh to resist shattering or laminated glass which comprises several layers of intumescent material which expands in response to temperature to hold the glass together.However, the Georgian wired glass has aesthetic limitations and the laminated glass is expensive.

It is an object of the present invention to provide an inexpensive fire-resistant device which allows the use of conventional glazing, for example clear float glass, in partition units, and which is capable of attaining International Standard levels of fire resistance for glazed units.

Accordingly, the present invention consists in a fire-resistant device for protecting a partitioning unit, said device comprising a fire-resistant screen arranged to be retained above the unit and temperature-responsive means for releasing the screen such that it covers at least a part of the unit upon detection of an elevated temperature indicative of a fire. The partitioning unit may be wholly or partially glazed or solid. If it is partially glazed, the screen may just cover the glazed part.

The temperature-responsive means preferably comprises a retaining member, for example a pin, which supports the screen and a part of which is formed from a material, for example a thermoplastics material, which softens at a temperature indicative of a fire, thereby releasing the screen.

Additionally, the temperature-responsive means may be manually actuated, for example in cases when the means do not detect an elevated temperature, actuation of the temperature-responsive means in response to elevated temperature is inhibited, or it is desired to release the screen sooner than at the temperature at which the temperature-responsive means is arranged to respond.

In a preferred embodiment, the fire-resistant screen is a weighted blanket which may be retained above the partitioning unit within the space between a ceiling and a suspended ceiling. The blanket may be provided with a weight along one of its edges, the weight being supported by the temperature-responsive means located at the top of the partitioning unit adjacent the side thereof, such that, upon detecting an elevated temperature indicative of a fire, the temperature-responsive means releases the weight to cause the blanket to drop down into a position substantially parallel to the partitioning unit, the opposite edge of the blanket being retained at the top of the partitioning unit.

A blanket, together with temperature-responsive means, may be provided for each side of the partitioning unit.

Alternatively, the blanket may be provided with a further weight at its opposite edge, the further weight being retained by a further temperature-responsive means located at the top of the partitioning unit adjacent the other side thereof, such that the blanket can drop down to cover either side of the partitioning unit depending on which temperature-responsive means is activated. In this way, the blanket will cover the side of the partitioning unit which faces the fire.

Preferably, the blanket comprises a layer of fireresistant mineral wool covered on one or both sides by a fine wire mesh. The blanket may be of any required size in order to cover the whole partitioning unit or only the glazed portion if the unit is partially glazed.

In an alternative embodiment, the fire resistant screen consists of a hinged panel assembly comprising one or more panels of fire-resistant material retained above and adjacent to the partitioning unit by means of fastening the assembly to a ceiling or suspended ceiling at the top of the partition unit.

The or each panel may typically consist of a mixture of a high melting point material, such as mica or glass in granular form, held together with an appropriate binding material, such as calcium sulphate.

Preferably where a plurality of panels are provided, the panels are laid flat upon each other with he uppermost panel being hinged to the ceiling or suspended ceiling, when the assembly is adjacent the top of the partition unit. The uppermost panel may be hinged to the ceiling or suspended ceiling by a hinge mechanism consisting of, for example, a strip of flexible material, such as fine wire mesh fastened along an edge of the panel.

The panels may also be hinged to each other along one edge thereof by a flexible material, such as fine wire mesh.

The panel assembly may be supported at the opposite end from the partition unit by the temperature-responsive means, for example a thermoplastic retaining pin, mounted on the ceiling or suspended ceiling. Thus, when the temperature-responsive means is activated, the bottom panel is released at the end farthest from the partition units.

A pivoting flange assembly may be mounted on the ceiling or suspended ceiling and comprise two releasably interconnected flanges, one flange being connected to the ceiling or suspended ceiling and the other flange to the bottom panel, said other flange being arranged to pivot downwardly relative to said one flange before disengaging from said one flange.

The invention will now be further described by way rf examples with reference to the accompanying drawings wherein: Fig. 1 shows a schematic vertical cross section of a partitioning unit incorporating a device in accordance with one embodiment of the present invention, Fig. 2 shows a schematic enlarged side view of a part of the device shown in figure 1, Fig. 3 shows a schematic vertical cross section of the device in a position protecting the partitioning unit, Fic. 4 shows a schematic vertical cross section of a partition unit incorporating a device in accordance with an alternatise embodiment of the present invention, Fig. 5 shows a schematic vertical cross-sectisn of a part of the ?vice shown in figure 4, Fig. 6 stows a schematic side view of another part of the device shows in figure 4, and Fig. 7 shcws a schematic isometric view of the device in Figs. 4 te 6 in the closed and released position.

Referring fiistly to Figures 1 to 3, a partition 1 having side panels 1C and 11 is substantially vertically disposed between a flocr 2 and a suspended ceiling 3 which forms a ceiling cavity 4 with an actual ceiling 5. In the position shown in Figure 1, the cavity 4 contains a folded fire-resistant blanket 6 sported by the suspended ceiling 3.

The blanket 6 has twc edges connected respectively to weights 7 and 8 extending along substantially the entire length of the blanket end edges. Weights 7,8 are each supported in an upper position adjacent the top of the partition 1 by a respective temperature-responsive mechanism. Each mechanism preferably comprises a temperature responsive retaining pin 9, which may be made of-a material which softens at elevated temperatures, for example a thermoplastics material. Upon softening or melting of the pin at elevated temperatures, the weight is released causing the blanket to drop down over the partition.

If the elevated temperature is detected by the temperature-responsive mechanism supporting weight 8, the blanket drops down over side panel 11 and the weight 7 retained by the other temperature-responsive mechanism acts as an end stop to prevent the blanket from falling completely to the floor once the slack has been taken up.

If the elevated temperature is detected by the temperature-responsive mechanism associated with weight 7 then the weight 7 drops, so that the blanket covers side panel 10, with weight 8 acting as the end stop at the top of partition 1.

In this way, the blanket 6 will fall between the fire and the partition whichever direction the fire approaches the partition.

It is important to be able to regularly test that the device is in good working order for example by removing the retaining pin to effect deployment of the blanket.

In order to aid smooth falling of the blanket and also to facilitate replacement of the blanket after testing, the suspended ceiling 3 is provided with a specially contoured and removable edge 12 having a rounded corner 13 and appropriate attachment means for example slot and tongue members 14. To replace a blanket after testing, the edge 12 is removed allowing more room to manually manoeuvre the blanket back into the cavity 4 whereupon the ceiling edge 12 may be replaced and the weight reengaged with the retaining pins. If the cavity 4 is particularly restricted then a larger section of the suspended ceiling 3 may be temporarily removed and subsequently refitted.

The retaining pin 9 is capable of being readily removed manually. In this way, the blanket can (a) be dropped more quickly over the side of the partition exposed to the fire, rather than waiting for high temperature activation, or (b) a second blanket can be manually re leased to cover the unexposed side of the partition in order to afford protection in addition to the first fireresistant blanket or in the case when the first blanket is prevented from being released.

As an alternative to supporting the blanket above a suspended ceiling 3, a blanket storage cassette (not shown) which is suitably attached to the ceiling or adjacent the top of the partition 1 may be used.

The blanket 6 may be made from any suitable fireresistant material, for example a fire-resistant mineral wool, of nominal width equal to the width of the partition unit with at least the outer surface of the blanket facing the fire being covered in a fine wire mesh for protecting the blanket during installation, deployment and exposure to fire.

The weights 7 and 8 are made of any appropriate materials and construction, for example a steel tube containing a bulk material, such as sand, to provide sufficient weight to pull down the blanket.

Alternatively, if the partition is double glazed, the blanket could be arranged to drop between the two glass panes in response to elevated temperatures occuring on either side of the partition.

In an alternative embodiment of the invention, with reference to Figures 4 to 7, the fire-resistant screen comprises a folded fire-resistant panel assembly 15 or 16 secured to the ceiling 5 adjacent either side of the top of the partition 1.

As shown in Figure 5, an uppermost panel 17 is secured to the ceiling 5 by a flexible hinge 18 and a holding bracket 19. The panel 17 is then secured to an intermediate panel 20 by means of a flexible hinge 21.

Similarly the intermediate panel 20 is secured to a bottom panel 22 by a flexible hinge 23. The bottom panel 22 is supported at one end by a temperature-responsive retaining pin 24, preferably of thermoplastics material, mounted on a ceiling bracket 25.

If the retaining pin 9 melts in response to an elevated temperature, the bottom panel 22 is released and all of the panels pivot relative to each other about their flexible hinges and drop down vertically in front of the partition. Additionally, the flexible hinge 18 pivots through approximately 900 so as to lie substantially parallel to the partition.

As shown in figure 6, the bottom panel 22 is supported at the end nearest the partition by a pivoting flange assembly comprising a flange 26 which locates into a further ceiling mounted flange 27. As the bottom panel 22 is released at the retaining pin end, the support flange 26 pivots around the ceiling mounted flange 27 until it has passed through 900 and is substantially parallel with the partition 1, whereupon the bottom panel 22 will no longer be constrained by the support flange 26 and will drop towards the floor allowing panels 17 and 20 to drop down also. The flanges 26,27 are preferably made of thin metal plate and are located on either side of the bottom panel 22.

The objective of the pivot mechanism is to ensure that the bottom panel has rotated through 900 before the upper panels start to fall. Without this feature there may be a danger that the panels will be obstructed as they fall by items such as furniture placed close to the glazed unit.

In order to provide an effective joint along the hinged edge of two adjacent panels, the panel edges may be profiled to fit into each other.

Figure 7 shows the embodiment in Figs. 4-6 in its supported position adjacent the ceiling and in its released position adjacent the partition. The folded fire-resistant device 15 is shown from above, being supported at one end by the retaining pin 24 and the ceiling bracket 25. At the opposite end, the device is supported by the flexible hinge 18 and interfacing flanges 26 and 27. In the released position, the device continues to be retained by the flexible hinges 18,21 and 23.

The device shown in Figures 4-7 may be manually tested by pressing the bottom panel away from the retaining pin and allowing the panels to drop down. This will be achieved by raising the panel assembly at the retaining pin end with a device such as a conventional straight length of rod and lifting clear of the retaining pin. Replacement after testing is achieved by re-folding the panels, interconnecting the flanges 26 and 27, and replacing the retaining pin 24.

Although specific embodiments have been described, it will be apparent that other examples may be envisaged without departing from the scope of the invention as defined in the appended claims. For example, the temperature-responsive means may comprise a temperature sensor, such as a thermocouple, arranged to activate a solenoid to retract one or more retaining pins supporting the fire-resistant screen when elevated temperatures are sensed.

Claims

1. A fire-resistant device for protecting a partitioning unit, said device comprising a fire-resistant screen arranged to be retained above the unit and temperatureresponsive means for releasing the screen such that it covers at least a part of the unit upon detection of an elevated temperature indicative of a fire.

2. A device as claimed in claim 1, wherein the temperature-responsive means comprises a retaining member, which supports the screen and at least a part of which is formed from a material which softens at a temperature indicative of a fire, thereby releasing the screen.

3. A device as claimed in claim 2, wherein the material is a thermoplastics material.

4. A device as claimed in claim 2 or 3, wherein the retaining member is in the shape of a pin.

5. A device as claimed in any preceding claim, wherein the temperature-responsive means can be manually actuated.

6. A device as claimed in any preceding claim, wherein the fire-resistant screen is a weighted blanket which is intended to be retained above the partitioning unit within the space between a ceiling and a suspended ceiling.

7. A device as claimed in claim 6, wherein the blanket is provided with a weight along one of its edges, the weight being supported by the temperature-responsive means arranged to be located at the top of the partitioning unit adjacent the side thereof, such that, upon detecting an elevated temperature indicative of a fire, the temperature-responsive means releases the weight to cause the blanket to drop down into a position substantially parallel to the partitioning unit, the opposite edge of the blanket being retained at the top of the partitioning unit.

8. A device as claimed in claim 6 or 7, wherein a blanket and temperature-responsive means are provided for each side of the partitioning unit.

9. A device as claimed in claim 6 or 7, wherein the blanket is provided with a further weight at its opposite edge, the further weight being retained by a further temperature-responsive means arranged to be located at the top of the partitioning unit adjacent the other side thereof, such that the blanket can drop down to cover either side of the partitioning unit depending on which temperature-responsive means is activated.

10. A device as claimed in any one of claims 6 to 9, wherein the blanket comprises a layer of fire-resistant mineral wool covered on one or both sides by a fine wire mesh.

11. A device as claimed in any one of claims 1 to 5, wherein the fire-resistant screen consists of a hinged panel assembly comprising one or more panels of fireresistant material retained above and adjacent to the partitioning unit by means of fastening the assembly to a ceiling or suspended ceiling at the top of the partitioning unit.

12. A device as claimed in claim 11, wherein the or each panel consists of a mixture of a high melting point material, such as mica or glass in granular form, held together with an appropriate binding material, such as calcium sulphate.

13. A device as claimed in claim 11 or 12, wherein a plurality of panels is provided, and the panels are laid flat upon each other with the uppermost panel being hinged to the ceiling or suspended ceiling when the assembly is adjacent the top of the partitioning unit.

14. A device as claimed in claim 13, wherein the uppermost panel is hinged to the ceiling or suspended ceiling by a hinge mechanism consisting of a strip of flexible material, such as fine wire mesh, fastened along an edge of the panel.

15. A device as claimed in claim 13 or 14, wherein adjacent panels are hinged to each other along adjacent edges thereof by a flexible material, such as fine wire mesh.

16. A device as claimed in any one of claims 11 to 15, wherein the panel assembly is supported at the opposite end from the partitioning unit by the temperature-responsive means, said temperature-responsive means being supported from the ceiling or suspended ceiling.

17. A device as claimed in any one of claims 13 to 16, wherein a pivotal flange assembly is supported from the ceiling or suspended ceiling and comprises two releasably interconnected flanges, one flange being connected to the ceiling or suspended ceiling and the other flange to the bottom panel, said other flange being arranged, when said hinged panel assembly is released by said temperatureresponsive means, to pivot downwardly relative to said one flange before disengaging from said one flange.

18. A fire-resistant device for protecting a partitioning unit, said device being substantially as herein described with reference to Figs. 1 to 3 or Figs. 4 to 7 of the accompanying drawings.