AU615959B2

AU615959B2 - Fire-resistant seal

Info

Publication number: AU615959B2
Application number: AU25024/88A
Authority: AU
Inventors: Peter Jackman; Jeffrey Robert Skeggs
Original assignee: BRIGGS AMASCO Ltd
Current assignee: BRIGGS AMASCO Ltd
Priority date: 1987-11-13
Filing date: 1988-11-11
Publication date: 1991-10-17
Anticipated expiration: 2008-11-11
Also published as: GB2212539A; GB2212539B; IE883404L; GB8726684D0; AU2502488A

Description

PATE~

COMPLETE

FOR

Short Title: mnt, Cl: Application Number: Lodged: Complete Specification-Lodged; Accepted; Published: RelatLdpsrd:

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4JTS ACT 1952

SPECIFICATION

RIG INAL) OFFICE USE Form 0 0 TO BE COMPLETED BY APPLICANT BRIGGS AMASCO0 LTD.

Gorst Road, Park Royal, London NW1O 6LT, England Actual Inventor: Address fooService: CAIJLINANS Patent Attorneys, of 48-50 Bridge Road, Richmond, State of Victoria, Australia.

Complote Speci~mtIon for the invention entitled: "FIRE-RESISTANT SEAL" Tho following statement Is a full doscription of this Invention, Including the best method of performing It known to me I- Note., The description Is to be typed In double spacing, pico qpo face, In an area not exceeding 250 mm In depth and 160 mm In width, on tough white paper of good qwt~ty and It Is to be Inserted inside this form, FIRE-RESISTANT SEAL This invention relates to an assembly, especially, but not exclusi 'ely, for use with fire resistant doors, to effect a seal around the edges of a door between the door and its surround.

The effectiveness uf a fire-resistant door is destroyed when cracks or gaps occur through which smoke, flames or hot gases may pass. For many doors, a gap between the door and its doorcase is required to allow the door to be opened and closed easily. Often this gap extends around at least three edges 6he door. The gap must be sealed in the event of a fire if the door is to provide an effective barrier to the fire. The performance of fire-resistant doors is currently limited by the strength and durability of the seals with their surrounds.

0000 It is known to seal a gap present between a fire-i 'sistant door o a S and its surround by arranging an open channel containing intumescent material to run along the edges of the door, or of the surround, or 0oo0 both. The intumescent material which is in strip form is stuck to 0. the base of the channel, When subjected to a sufficiently high 9 0 0 a temperature, for example in the case of a fire, the intumescent material is activated to expand, extruding from th3 channel to bridge the gap between the door and the surround and form a seal.

0 0. Sometimes a p.v.c. sheath or membrane is used to protect the °0 intumescent material in the channel. This iwmbrane is either 0 00 0°o00 pierced or is able to expand when the intumescent material extrudes 0 from the channel. However, at sufficiently high temperatures the, p.v.c. can ignite, contributing to the fire, and then ceasing to 0provide structural protection for the expanded intumescent material.

In another known arrangement, the channel has sides that are 0 0 bent inwards at the mouth of the channel forming lips partially 0o o covering the outer surface of the ntumescent material. When the intumescent material expands, the lips are distorted, being pushed i outwards, to form a seal with an opposing adjacent surface. For best results with this arrangement, suitable channels should be fitted both to the edges of a door and to its surround, It is desirable that an arrangement to effect a seal should, -2when activated, constrain the intumescent material to remain within the gap to ensure a reliable seal and prevent wastage of intumescent material. It is also desirable that the seal shculd be effected by a barrier of a material that is stable at high temperatures and which will remain in position keeping the seal intact should the intumescent material decompose at high temperatures.

In accordance with the present invention, therefore, there is pro ided an assembly for sealing a gap between two adjacent surfaces to restrict the passage of air through the gap in the event of a fire, said assembly indcading a generally U-shaped channel running along a first of the surfaces, facing towards a second 10 surface on the other side of the gap, intumescent material in the channel, and an elongate cap of a material that is stable at high temperatures, of generally Uft shaped cross-section, fitting into the channel, the sides of the cap and the sides of the channel overlapping one another so as to enclose the intumescent material, the sides of the channel gripping the cap normally to retain it in the channel, the ,44:15 intumescent material being activated when subjected to a sufficiently high temperature to expand forcing the cap to slide outwardly from the channel 4 towards the second surface.

With this assembly, when the intumescent material expands it cannot escape easily from the enclosure formed by the cap and the channel. Preferably the channel is cf metal, particularly steel. Thus virtually all the pressure exerted by the expanding intumescent material is used to force the cap into firm sealing contact with the second surface.

Should the temperature become so high that the intumescent material decomposes, the cap would remain in position bridging the gap, keeping the seal in tact.

In accordance with the present invention, thcrefore, there is provided an assembly for effecting a fire-resistant seal across a gap between a fire-resistant 2A door and its door surround in the even of a fire, said assembly including a channel running along the edge surface of the door opposing the edge surface of the door surround, wherein intumescent material is positioned in the channel, and an elongate cap made of a material that is stable at high temperatures fits in the mouth of the channel, covering the intumescent material, the sides of the cap being resilient to overlap with and grip the sides of the channel, to hold the cap in position normally and the intumescent material being activated when subject to a sufficiently high temperature to expand forcing the cap to slide outwardly from the channel towards the edge surface of the door surround.

In order that the invention may be more clearly understood and put o: into practical effect there shall now be described in detail a preferred embodiment ,0:o 0 of an assembly for sealing a gap between to adjacent surfaces in accordance with 00 0 the invention. The ensuing description is given by way of non-limitative example only and is with reference to the accompanying drawings, wherein: "015 Fig. 1 is a horizontal cross-section through a portion of a door and 0, surround embodying the invention; Fig. 2 is a horizontal cross-section through a portion of another door and surround embodying the invention; and Fig. 3 is a horizontal cross-section through a portion of another door and surround embodying the invention, Referring to Fig. 1, this shows a portion of a fire-resistant

I

I -3door 11 and a doorcase 10. The door and doorcase are made up of profiled hollow tubular steel sections. The adjacent sections of the doorcase 10 and door 11 have opposing surfaces 12 aud 13 respectively, separated by a gap 21. A generally U-shaped channel 14 is formed by a recess in the surface 13. As shown in the drawings, the channel 14 has sides 22 sloping inwards at an angle of approximately 15' such that the channel 14 is narrower at its mouth than at its base 23. However in other embodiments the sides of the channel need not be sloping. A steel elongate cap 15 fits inside the channel 14. The cap 15 is of generally U-shaped section and has resilient sides 24 that tend to spring outwards. The cap 15 is fitted in the channel 14 by squeezing the sides 24 of the cap inwards towards one another, inserting the cap 15 into the channel 14 and releasing the sides 24 of the cap 15 allowing them to spring into position. The sides 24 of the cap 15 and the sides 22 of the channel 14 overlap one another, the sides 22 of the channel 14 gripping the sides 24 of the cap 15 so as to normally retain the cap in the channel 14. The length of the sides 24 of the cap 15 are such that the height of the cap alone is greater than the width of S, :20 the gap 21 between the surfaces 12 and 13. Intumescent material 16 is arranged in layers inside the cavity formed by the cap 15 and the channel 14. A suitable intumescent material comprises a core of hydrated sodium silicate reinforced with glass fibres, the core being protected by a coating of epoxide resin. A rubber 25 weatherstrip seal i8 is mounted in a channel 17 formed by a recess in the surface 12.

*'Oo Before the seal is activated by a fire, the outer surface 25 9f o the cap 15 is flush with or _ightly proud of the surface 13, and the weatherstrip seal prevents the passage of draughts through the to o30 gap 21 between the door and doorcase.

In the event of a fire, heat is conducted to the intumescent material 16 through the steel frame 11 and cap 15. When the intumescent material 16 is subjected to a sufficiently high temperature, it expands forcing the cap 15 to slide outwardly from the channel 14. The force of the expanding intumescent material is sufficient to overcome the resistance to outward movement of the cap due to the resilience of its sides 24, the sides 24 being squeezed i S- I 4inwardly by the edges of the channel as the cap is pushed outwardly from the channel. The outer face 25 of the cap 15 makes sealing contact with the surface 12, thereby preventing the passage of smoke, hot gases and flames through the gap 21. The sides 24 of the cap 15 and the sides 22 of the channel 14 remain overlapping one another, the cap 15 and channel 14 always enclosing the intumescent material 16. Thus the intumescent material 16 cannot escape when expanding. All the pressure exerted by the expanding intumescent material is used to force the cap 15 into sealing contact with the surface 12.

If the fire becomes so hot that the weatherstrip seal 18 and the intumescent material 16 decompose, the stainless steel cap still remains in position sealing the gap 21. This provides a durable seal improving the performance of the fire door.

The stainless steel cap 15 completely covers an otherwise exposed surface of the intumescent material, providing protk;ction against the possibility of the assembly being attacked by vandals.

0000 oo0 Referring to Figure 2, this shows a portion of another fire- So O: resistant door 11 and a doorcase 10 similar to those in the previous 20 arrangement. In this figure, a stainless steel elongate cap 26 of a o 0 generally U-shaped cross-section has sides 27 that are parallel to 0 0 0 one another. In other embodiments the sides could be tapered, i'he o cap 26 fits into a channel 14 containing intumescent material 16 as in the previous arrangement. The channel 14 has sloping sides 22 such that the channel is narrower at its mouth than at its base 23.

The sides 27 of the cap 26 make a tight fit with the edges 28 of the a o a mouth of the channel 14 so that the cap is normally retained in thq a 04 00 a channel 14.

When the intumescent material 16 is activated, the force of the oa" °30 expanding material is sufficient to overcome the frictional grip of the edges 28 of the channel 14 on the sides 27 of the cap 26 so that the cap slides outwardly with respect to the channel and engages to o opposite surface 12.

0 0 If the fire becomes so hot that the intumescent material 16 I decomposes, the stainless steel cap 26 still remains in position bridging the gap 21, keeping the seal intact. This provides a durable seal improving the performance of the fire door. i In the embodiment of Figure 2, a weatherstrip seal 20 is mounted on the outer face of the cap 26 rather than on the surface 12 as in the previous embodiment.

Figure 3 shows a modification of the arrangement of Figure 2 in which the channel is supported on the hollow tubular steel section of the door case 10 by two formed steel housings Although in the arrangements described above, the channel 14t has been de~3cribed running along the surface 13 of a fire-resistant door 11, it will be appreciated that in other arrangements, the channel 1~4 may run along a surface 12 of a doorcase Although in the arrangements described above, the cap is only used on one sido of the gap, similar caps may be fitted to channels containing intumescent material on either side of the gap, to provide increased fire protection. The naps could oppose each other, or could be offset, the former arrangement being particularly suitable for sealing large gaps.

It will be appreciated that the cap and intumescent material @000can be fitted quickly and easily to a channel without the need for any screws, rivets or adhesive, making maintenance simple, The cap o 20 and intumescent material could be fitted to suitable channels 0 already present in many doors and doorcases, and the cap could be 0 added to an existing combination of a channel and intumescent 001 material to improve their fire-resistant seal.

Although the invention has been described foc use to seal gaps between fire resistant doors and their surrounds, it will be C appreciated that the invention can be used for sealing gaps existing O ~0 in other structures.

0" *00 o00 00 0 0 ~0 00 00

Claims

1. A asseaibly for seatinig a gap between two adjacent suf aces to restrict the passage of air through the gap in -the evenit of~ a fire, said as'ly incJ~udiniq a generally U-shaped charnel ruiing along a first of the surfaces, facing towards a J second surf-ace on the other side of the g-ap, Intumescent material inhe channel1, and an elongate cap of a material thatisalet h-igh teaueratures, of genierally U-shaped cross-section, fibting into the chiantel, the sides of the cap and the sides of the channel overlaplig onie anothier so as to enclose the intumescent. noterial, the sides of the channiel gripping the cuip normally to retain it in Ot- the channiel, the itmt.scent mterial beig activatd whnn subjected asufficiently hIgh teiiperature to expri forcing the cap to sl:d ouwrl fraii the channel towards the second surface. 00 04 a:of the cap an6 the sides of the channel rii overlapping orie oriotlier when the cap slides outwardly towards with the second o sux-facco. Th'e asseibly according to cla-til I or claim 2, in wichd 4 00 the cap arnd the channel together xcuplekely enclose the inumescent

4. The assambly according to any one of clabrs 1 -to 3, iii wichi a weathexstrip seal is nmnnted on the second surface. The asserubly accordiicj to any one- of claim 1 to 4, in hioh a weatrstrip seal is ittmunted on the- cap. 6, The asseribly according to any one of the preceding claimrs, in which the channel is a recess :Corxrled on Whe first surf ace. 7, 'The assentbly according to any onle of the precedinq claiiis 1 in whichi the f itst surface Is an edge of a door, and the second surface. is an edge of a doorsunnourid.

8. The assemrbly according to claimi 7, in which the channiel e-Xtenlds around all edges of the door.

9. The assembly according to any one of Ule preceding claims, in which the cap is of metal. The assenbly according to any one of the preceding claims, in which the sides of the ch annel taper in towards one another from the base of the channel towards its iruth.

11. An assembly as claimed in claim 1, substantially as hereinbefora described, With reference to the accmpanying drawings.

12. An assembly for effecting a fire-resistant seal across a gap between a fire-resistant door and its door surround in the event of a fire, said asseibly including a channel runing along the edge surface of the chor opposing the edge surface of the door surround, wherein intumescent nmterial is positioned in the channel, and an elongate cap made of a material that is stable at high teiperatures fits in the rnuth of the channel, coverig the intumeset material, the sides of the cap beinq resilient to overlap with andt grip the sides of the channel, to bold the cap in position normally and the intumescent material being activated when subject to a sufficiently high taiperature to expand forcing the cap to slide outwardly from the channel towards the edge surface of the door surround. DATED this 30th clay of July, 1991 BRIGGS AMASCO LTD. By their Patent Attorneys: CALLINAN LAWRIE i. i II it II i i r 4: k: