AU624288B2 - Seal for fire dampers - Google Patents

Description

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624288 S F Ref; 126010 FORM COMMONWEALTH OF AUSTRALIA PATENTS ACT 1952 COMPLETE SPECIFICATION

(ORIGINAL)

FOR OFFICE USE: Class Int. Class zt CI it i t it t t riU~ Application Number: Lodged: Priority: PJ9688 18 April 1990 Accepted: Published: Related Art: Name and Address of Applicant: Actual Inventor: Address for Service: Jackson International Pty. Limited 8 Pike Street Rydalmere New South Wales 2116

AUSTRALIA

Roy James Jackson Spruson Ferguson, Patent Attorneys, Level 33 St Martins Tower, 31 Market Street, Sydney, New South Walts, 2000, Australia

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Complete Specification for the invention entitled: Seal for Fire Dampers The following statement is a full description of this invention, including the best method of performing it known to me/us 5815/2

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iii iP' i j r j 2- BACKGROUND OF THE INVENTION This invention relates to fire dampers, and more particularly to seals for fire dampers.

In buildings having air-conditioning or ventilation systems, the ductwork provided through the building provides a ready means by which fire and products of combustion in any part of the building can spread throughout the building. To impede this spread of fire and products of combustion, according to Australian Standard 7668, fire dampers must be installed 'n wall, floor and ceiling penetrations which have been formed to permit the installation of air-handling systems.

As described in the foreward to Australian Standard 1682 relating to the requirements for such fire dampers, fire dampers are intended to partially restore the fire resistance of a wall, floor or ceiling through which a penetration has been made. Accordingly, fire dampers must provide an effective barrier to the passage of fire and products of combustion and must be designed and constructed so that they operate under emergency conditions in extreme temperatures.

e0 As set out in Australian Standard 1668, fire dampers must be attached to the ductwork in such a manner that any deformation of the ductwork under fire conditions will not dislodge the damper or affect its operation or performance. Furthermore, the space between the fire damper and the opening in the wall must be filled with a compressible, non-combustible material for the full thickness of the wall. This material must be compressible so as to allow the frame of the fire damper to expand as it heats up and must adequately seal this expansion gap between the frame and the wall so as to prevent the passage of fire or combustion products.

Conventionally, this gap has been filled with mineral fibre packing, which must be laboriously rammed into the space between the frame of the -i damper and the wall ensuring that there are no voids left. It is not yet certain whether the use of such mineral fibres poses a health problem if inhaled over a period of time.

Alternatively, the mineral ft're packing can be wrapped around the fire damper and the fire damper can be placed in the wall during y construction. However, this method cannot guarantee that the correct clearance is provided for the fire damper to expand when subjected to fire conditions.

Therefore, it is an object of the present invention to enable the space between a frame of a fire damper and a wall to be sealed to 1.

csh/1041E 0* If -3substantially prevent fire and combustion products from passing through and yet be easier and cheaper to install than the known methods.

SUMMARY OF THE INVENTION Accordingly, the present invention provides, in one aspect, a seal for fitting in an opening between a fire damper and a wall, the seal comprising a longitudinal, metal sheet having a substantially flat central portion and two longitudinal side portions, the side portions being folded at least twice substantially parallel to the longitudinal axis of the sheet, a first of the folds being through more than ninety degrees so that both the side portions extend towards each other on one side of the central portion of the sheet and a second fold being through more than ninety degrees in an opposite direction to that of the first fold so that outer parts of the side portions extend away from each other substantially parallel to the sheet, the side poi"ions thereby taking on a ,15 concertina-like configuration.

0 0 0 0 The central portion of the sheet is preferably of substantially the same width as the thickness of the wall into which it is to be fitted.

Furthermore, the sheet is preferably of substantially the same length as a side of the opening into which it is to be fitted.

In a preferred embodiment, the outer part of one side portion extends beyond the position of the first fold, i.e. beyond the side edge of the Scentral portion. This extended part of the side portion can be used to hold the seal in position around a fire damper by clamping it between the fire damper and retaining angles or channels fixed to the fire damper for o.125 positioning the fire damper in the opening in the wall.

According to a second aspect of the present inverition, there is provided a sealing system for fitting in an opening between a fire damper I and a wall, the system comprising a plurality of seals of the type aoJ described above for fitting into the opening along straight edges thereof i and a plurality of corner angles, each corner angle comprising a substantially flat metal sheet of a width substantially similar to the width of the central portion of the seals and being bent along its width into two portions, each of which can be fitted between the central and side portions of an adjacent seal so as to provide a sealing effect between two adjacent seals.

In a preferred embodiment, the two portions of the corner angle are .bent at approximately ninety degrees to each other.

csh/1041E -4- BRIEF DESCRIPTION OF THE DRAWINGS One embodiment of the invention will now be more fully described, by way of example, with reference to the drawings, of which: Figure 1 is an exploded schematic diagram of two seals according to the invention joined together by a corner angle; and Figure 2 is a cross-sectional schematic view through part of an opening in a wall having a fire damper and a seal according to the invention in position.

DETAILED DESCRIPTION OF ONE EMBODIMENT OF THE INVENTION Thus, as shown in the Figures, a compressible, non-combustible seal 1 for sealing an opening between a wall 2 and a fire damper 3 is formea of a longitudinal sheet of metal having a flat, central portion 4 of 0A: substantially the same width as the thickness of the wall 2. The central portion 4 is integrally formed with longitudinal side portions 5, each 0 04 1 having an inner part 6 and an outer part 7 defined by two longitudinal folds 8 and 9 running parallel to the longitudinal axis of the seal. The o first folds 8, between the central portion 4 and the inner part of the side ma portions 5, are greater than ninety degrees so as to form an acute angle between the central portion 4 and the side portion 5 with both the side portions extending towards each other. The second folds 9, between the inner 6 and outer 7 parts of the side portions 5, are also greater than o o ninety degrees so as to cause the outer parts 7 of the side portions 5 to extend away from each other substantially parallel to the central portion 4 of the seal 1. The side portions 5 therefore have a concertina-like configuration allowing the seal to be compressed between the central portion 4 and the outer parts 7 of the side portions The outer part 7 of one side portion 5 is made to extend beyond the edge of the central portion 4. In this way, as shown in Figure 2, this extended portion of the side portion 5 can be clamped between the fire damper 3 and the retaining angle 10 so as to hold the seal 1 in place. As further shown in Figure 2, the retaining angle is arranged to be attached to the fire damper 3 and to position the damper 3 within an opening in a wall 2 by extending perpendicularly to the damper 3 along the external sides of wall 2.

It will be apparent that, when there is a fire such that the casing of damper 3 heats up and expands, it will act to force the casing of the damper 3 upwards against the outer parts 7 of the side portions 5of seal 1.

-i csh/lO41E Obviously, the metal seal will also expand as it heats up. Due to the concertina-like configuration of the side portions 5 of the seal 1, the seal 1 can be compressed, thus taking up the expansion of the casing of damper 3. It should also be noted that such compression causes the extended portion of the side portion 5 to move from between the fire damper 3 and the retaining angle 10 and therefore, in order to permit such movement, the extended portion of the seal should not be fixed to the fire damper 3 or retaining angle Although retaining angle 10 has been shown in Figure 2 in one particular configuration, it will be clear to persons skilled in the art that other types and configurations of retaining angles or channels, for example two right angle channels, one on either side of the wall, could be used instead.

Bo"o Turning now to Figure 1 again, there are shown there two seals 1 at 5 right angles to each other, as they would be in position around a fire ,oo, damper. Of course, there would normally be four such seals around the damper, but only two adjacent seals are being shown here. In order to prevent passage of fire or combustion products from around the edges of the seals 1, there is provided a corner angle 12 formed of a single, bent piece of sheet metal of a width substantially the same as the width of the central portion 4 of the seals 1, but just slighly smaller, so that the 0o ends of the corner angle 12 can slide into adjacent seals 1 between the central portion 4 and the inner part 6 of the side portion 5 thereof. When the fire damper expands and causes the seals to compress, the ends of the o1s25 corner angle simply slide within the seals 1, thus maintaining the integrity of the overall sealing effect.

It will be apparent, therefore, that the sealing system described o above has the same features of compressibility and non-combustibility as j e the conventional mineral fibre wool, but is substantially easier to install.

The seal according to the present invention also has the advantage, however, that the fire damper can be supplied to a builder with the seals already in place around the damper so that the fire damper can be built directly into a wall by a bricklayer rather than having to build a wall leaving an opening into which the damper is later fitted. The shape and size of the seal can be made such that the bricklayer only needs to lay the bricks so as to contact the surface of the seal in order to make sure that adequate expansion space is provided. csh/1041E Furthermore, the shape of the seals and corner angles substantially prevents the entry of brick mortar into the expansion gap provided by the seal during installation. Therefore a bricklayer can fix the damper in position without concern that insufficient expansion space has been left around the damper. This will reduce the number of instances where the opening that has been left in a wall is later discovered to provide too small an expansion gap and the installation does not pass inspection.

A further advantage of the preferred embodiment of the invention is that, by clamping the extended portion of the side portion of the seal between the brackets attached to the fire damper, the seals are held in place around the damper so that there are no loose parts which could be lost or wrongly positioned by inexperienced builders.

0011 o 0 4 i 0 a 09 csh/0O41E (f« 8* a 0 1 cs/04 94« iI

Claims (8)

1. A seal for fitting in an opening between a fire damper and a wall, the seal comprising a longitudinal, metal sheet having a substantially flat central portion and two longitudinal side portions, the side portions being folded at least twice substantially parallel to the longitudinal axis of the sheet, a first of the folds being through more than ninety degrees so that both the side portions extend towards each other on one side of the central portion of the sheet and a second fold being through more than ninety degrees in an opposite direction to that of the first fold so that outer parts of the side portions extend away from each other substantially parallel to the sheet, the side portions thereby taking on a concertina-like configuration.

2. A seal according to claim 1, wherein the central portion of the sheet is of substantially the same width as the thickness of the wall into which it is to be fitted. O

3. A seal according to either claim 1 or claim 2, wherein the sheet 04'° is of substantially the same length as a side of the opening into which it o, is to be fitted.

4. A seal according to either claim 1 or claim 2, wherein the outer part of one side portion extends outwardly beyond the position of the first fold. 0 *440 r4 o4

5. A sealing system for fitting into an opening between a fire damper and a wall, the system comprising a plurality of seals according to any preceding claim for fitting into the opening along straight edges Gss$ thereof and a plurality of corner angles, each corner angle comprising a substantially flat metal sheet of a width substantially similar to the width of the central portion of the seals and being bent along its width o into two portions, each of whi:h can be fitted between the central and side portions of an adjacent seal so as to provide a sealing effect between two adjacent seals.

6. A sealing system according to claim 5, wherein the two portions of the corner angle are bent at approximately ninety degrees to each other.

7. A seal for fitting in an opening between a fire damper and a wall substantially as hereinbefore described with reference to the drawings. icsh/1041E cshllO4lE 2 -8-

8. A sealing system for fitting into an opening between a fire damper and a wall substantially as hereinbefore described with reference to the drawings. DATED this TWENTY-SIXTH day of MARCH 1991 Jackson International Pty. Limited Patent Attorneys for the Applicant SPRUSON FERGUSON St II I I 1: 14 11 1 It IE I t I~ at csh/1041E 1 i ;i Ir ij 1 I-