AU730742B2 - Fire damper mounting system - Google Patents

Description

1

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

Name of Applicant/s: *5 S S

S

.*S

Actual Inventor/s: Address of Service: Invention Title: Malcolm Ravenscroft 1996 Limited Malcolm Gordon RAVENSCROFT and Dean Michael

JOHNSTON

BALDWIN SHELSTON WATERS 60 MARGARET STREET SYDNEY NSW 2000 "FIRE DAMPER MOUNTING SYSTEM" The following statement is a full description of this invention, including the best method of performing it known to us:- (File: 20981.00) -2- Fire Damper Mounting System Field of the Invention The present invention relates to methods and apparatus for mounting constructions/ devices in wall apertures. More particularly although not exclusively, the present invention relates to methods and apparatus for installing fire dampers in ducting systems at the point where the ducts penetrate walls, floors or ceilings within a building construction.

gee• Background to the Invention 0 Where ducting systems or any other type of passage is formed or penetrates a wall, '0 floor or ceiling in a building construction, a fire damper may be used to prevent the *passage of flame, heat and smoke through the duct or channel. A fire damper 10 generally corresponds to a hollow rectangular body containing a spring loaded rotatable disc, leaf type shutter or curtains either gravity or spring operated which, in its' "set" state is orientated to allow free passage of air through the duct or channel.

The disc or curtain is held in place by means of a heat sensitive clamping latching or S0" locking device which, when a maximum air temperature is reached, releases the disc or curtain whereby either springloading or gravity causes the flange to snap shut thereby sealing the duct or channel. The locating and installation of such devices poses a number of construction and safety problems.

Conventional fire damper mounting systems require the damper to be mounted to framing located within the wall cavity proximate the wall aperture through which ducting is to pass and in which the fire damper is mounted. This framing corresponds -3either to the stud material or wall formwork. Insulation is usually packed into the wall cavity between the damper and the walls interior formwork to protect the wall cavity from heat and minimise the fire potential in the wall cavity.

In the case of a plasterboard wall composed of a stud framework with a sheet or sheets of plasterboard on either side, if a fire starts on one side of the wall, the plasterboard lining exposed to the fire is progressively destroyed over a period of time.

This time period is a measure of a particular walls fire-rating. As the plasterboard *lining is degraded, it's structural integrity is significantly compromised. In such a situation, the support which the plasterboard lining provided to the fire damper is destroyed, thus severely reducing its effectiveness.

Known techniques for mounting fire dampers in wall apertures involves framing a wall °.*aperture using interior wall construction members. Then insulation material is around the damper in the wall cavity and the fire damper is attached to either side of the walls surface. This method is laborious and expensive. It also requires coordination between the building contractor subcontractor to determine and form precise hole locations and dimensions as well as installing framing around the aperture for fixing the damper mount in place. Further, there can be difficulties ensuring compliance with the appropriate building codes as each installation must be separately constructed by the subcontractor or other individual. It is known in the industry that consultants and contractors generally try to avoid a level of coordination between building contractors and subcontractors in order to minimise potential contractual difficulties. Therefore, fire damper installations tend to be problematic due to this required degree of coordination, the labour required and the regulatory compliance issues.

-4- It is an object of the present invention to provide a mounting means which overcomes or ameliorates some of the problems with the prior art, or at least provides a useful alternative.

Unless the text clearly requires otherwise, throughout the description and the claims, the words 'comprise', 'comprising' and the like are to be construed in an inclusive sense as opposed to an exclusive sense. That is to say, in a sense of 'including, but not limited to.' Disclosure of the Invention In one aspect the present invention provides an integrated mounting and insulating sleeve for a fire damper or other ventilation control means in a wall, floor or ceiling comprising: a first, substantially fire resistant, rigid sleeve exterior having first and second open ends; a second, substantially fire resistant, rigid sleeve interior having first and second open ends; i..

heat resistant insulating material sandwiched between the inside of the sleeve exterior and the outside of the sleeve interior to form an insulating sleeve having first and second open ends, the sleeve adapted to accommodate or locate a wall, floor or ceiling aperture component; o a flange located proximate the first open end of the sleeve, the flange secured to •oo* o the sleeve exterior so that the sleeve may be inserted into a wall, floor or ceiling aperture so that the flange is located flush on a first wall, floor or ceiling surface to enable mounting of the sleeve thereto; a second flange located proximate the second open end of the sleeve, the second flange being adapted so that it can be located at positions along the length of the sleeve exterior in such a manner that when the sleeve is located in a wall, floor or ceiling aperture, the sleeve is supported in position by means of either the first or second or both flanges secured to the wall, floor or ceiling.

Preferably the sleeve is hollow and either round, square, rectangular or other shape in cross section wherein the sleeve exterior and sleeve interior are composed of sheet metal having a fire resistant insulating material sandwiched therebetween.

Preferably the component is a fire damper which is dimensioned so that it can be supported by the sleeve.

The second flange may be affixed to the outside of the sleeve at a position so that the separation between the first and second flanges corresponds to a desired wall thickness whereby a wall cavity, through which the sleeve penetrates, is substantially completely insulated from the aperture formed when the sleeve is mounted in the wall.

In an alternative embodiment, the sleeve may be manufactured utilising a fire resistant rigid insulating material which may or may not also replace one or both metal surfaces.

In an alternative embodiment the sleeve in conjunction with a fire damper can be used in a fire rated, dry wall, floor or ceiling.

The sleeve may be adapted so that the first and second open ends can be secured to ductwork.

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II

Preferably the first and second flanges are secured to a first and second wall respectively using dry wall fasteners or the like.

Brief Description of the Drawings The invention will be now described by way of example only and with reference to the drawings in which: Figure 1 illustrates a side cross sectional view through a fire damper mounting device; 'oo Figure 2 illustrates a plan cross sectional view through a fire damper mounting device when located within a wall aperture; and Figure 3 illustrates a side cross sectional view of a mounting device used to position a fire rated air valve over a wall aperture.

:Referring to Figure 1, a mounting device is shown in side cross section. For the present purposes the device will be described in the context of locating a fire damper (not shown) in a wall cavity. The damper may be secured to ducting at either end to provide an air conduit passing through the wall. The present example refers primarily to plasterboard dry walls, a schematic construction of which is illustrated in Figure 2.

Such a wall construction usually comprises plasterboard layers 16 and 17 supported by stud material 31.

Referring again to Figure 1, the exemplary fire damper mounting system is shown having a circular cross section which is dimensioned to fit ducting. The mounting -7device comprises a cylindrical sleeve formed from an inner sheet metal surface 11, a second outer sheet metal surface 21 with a fire resistant insulating material 19 sandwiched between. The lengthwise or axial dimensions of the sleeve (11, 21, 19) are such that the entire wall cavity is completely closed off by the insulated section around the perimeter of the wall aperture. This can be seen in the lower part of Figure 1 in the wall cavity indicated by the numeral 18. The sleeve may incorporate tubular extensions at a first and second end 22 and 23 respectively. These extensions are adapted and dimensioned, in the present example, to fit to ductwork. For clarity, the Sfire damper is omitted from the schematic However, the dimensions of the cylindrical oooo sleeve are selected to accommodate a range of fire damper units which are available on the market.

First and second flanges 14 and 15 in Figure 1 are located around the sleeve. The first flange 14 is fixed in position on the sleeve. The second flange 15 may be moved axially along the sleeve so that a particular wall thickness can be accommodated therebetween. Referring to Figure 1,the flange 14 and sleeve (11, 21, 19) is inserted into the hole in the wall whereupon the flange 14 is secured to the plasterboard wall member 16 by means of dry wall fasteners or the like. In the present example, there are four fasteners per flange located around the insulating sleeve. This can vary depending on the size of the sleeve. This attachment holds the cylindrical insulating sleeve securely in the wall aperture. The second flange 15 is then positioned so as to be flush on the second plasterboard wall 17 whereupon it is secured to the exterior surface of the insulating sleeve 21 by means of mechanical fasteners. The second flange 15 is then attached to the wall in a manner similar to that for the first flange 14.

For fire damper mounting systems of small geometries (approximately 315 mm diameter for circular apertures or 350 mm square or rectangular apertures) the mounting flanges can be fixed directly to the plasterboard wall lining only. Therefore no framework is required immediately adjacent the hole for attaching. For larger size flanges flanges 14 and 15 are dimensioned to incorporate fixing to wall studs with intermediate fasteners into the plaster board.

If a fire is initiated adjacent the first wall 16 in Figure 1, the heat and flames will gradually destroy the plasterboard layer 16 to the point where the flange 14 is no longer supported by the inherent structure of the wall layer 16. At this point, the fire 10 damper mounting system becomes supported by the second flange 15 which is located on the protected second wall 17. It is considered that the novel aspect of the present system resides in providing a mounting technique which has built in redundancy in respect of the attacks by fire on either side of a dividing wall. Either S•flange 14 or 15 can, alone, support the weight of the fire damper and its mounting system.

The insulating layer 19 prevents heat from being transmitted into the wall cavity from the ducting. It also provides thermal and or acoustic insulation normally incorporated .o in heating ventilating and air-conditioning ductwork.

Conventional fire damper mounting constructions involve packing insulation manually into a cavity formed by stud work, plasterboard walls or other formwork located between the walls. Once installed there is no way of inspecting the insulation to ensure adequate uniformity, even if the fire damper is removed. Such known methods are dependent on the skill and integrity of the ductwork installation subcontractor and can be subject to variations in installation practices. It is considered that the present invention provides for a means of installing such devices in a highly uniform manner.

Further, the present fire damper mounting device may be provided in the form of a kitset. Such a kitset would include the sleeve and the flanges along with the fire damper and fixing devices. As the sleeve is supplied as an integral component with the fire resistant insulating material encapsulated in sheet metal sleeves, there is no danger of the insulating material escaping or being damaged in any way. Further, quality control can be uniformly monitored during construction of the sleeves and there is no opportunity for interference by a installation subcontractor or the like. Further, the mounting means may be used for components other than fire dampers. For 10 example, Figure 3 illustrates a fire rated air valve 40 installed at a first opening of a *"•sleeve. The mounting device again provides for a uniform insulating layer between the interior cavity of the wall 18 and the duct or air passage formed in the wall. Again, the flanges 14 and 15 are securely mounted to walls 18 and 17 thereby providing independent support for the mounting device should a fire start on either side of the 15 wall leading to the destruction of an adjacent wall.

Therefore, the present invention provides for a means for mounting wall hardware such as fire dampers, air valves and the like. The novel mounting means described herein, is advantageous in that it does not require the wall aperture to be framed. It is S•therefore capable of being installed solely by ducting subcontractors with virtually no chance of constructional variation from installation to installation. Further, the present invention is ideally adapted to being supplied in kitset form to ensure uniformity of installation and a consistent degree of quality. Such considerations are critical in safety related applications such as these.

While the present example has been provided in the context of tubular ducting, the present invention can be readily applied to situations where square apertures are formed in plasterboard walls or other shapes. The general technique of providing independent fail safe mountings for the support means is equally applicable to other wall aperture geometries. Further, walls are generally constructed in a number of standard thicknesses and therefore the kitset sleeve can be provided in corresponding axial lengths so that insulation is provided uniformly around the thickness of the wall aperture. Differing insulation values, as required by specific applications, can be achieved by varying the thermal characteristics and dimensions of the insulating layer.

Further modifications in the present invention will be clear to one skilled in the art and are to be considered to be within the scope of the present invention.

10 Where in the foregoing description reference has been made to elements or integers having known equivalents, then such equivalents are included as if they were individually set forth.

o Although the invention has been described by way of example and with reference to particular embodiments, it is to be understood that modifications and/or improvements 15 may be made without departing from the scope of the appended claims.

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Claims (9)

1. An integrated mounting and insulating sleeve for a fire damper or other ventilation control means in a wall, floor or ceiling aperture comprising: a first, substantially fire resistant, rigid sleeve exterior having first and second open ends; a second, substantially fire resistant, rigid sleeve interior having first and second open ends; heat resistant insulating material sandwiched between the inside of the sleeve exterior and the outside of the sleeve interior to form an insulating sleeve having first and second open ends, the sleeve adapted to accommodate or locate a wall, floor or ceiling aperture component; a flange located proximate the first open end of the sleeve, the flange secured to the sleeve exterior so that the sleeve may be inserted into a wall, floor or ceiling aperture so that the flange is located flush on a first wall, floor or ceiling surface to enable mounting of the sleeve thereto; a second flange located proximate the second open end of the sleeve, the second flange being adapted so that it can be located at positions along the length of the sleeve exterior in such a manner that when the sleeve is -located in a wall, floor or ceiling aperture, the sleeve is supported in position by means of either the first or second or both flanges secured to the wall, floor or ceiling.

2. An integrated mounting and insulating sleeve as claimed in claim 1 wherein the sleeve is hollow and either round, square, rectangular or other shape in cross section, wherein the sleeve exterior and sleeve interior are composed of sheet metal having a fire resistant insulating material sandwiched therebetween. -12-

3. An integrated mounting and insulating sleeve as claimed in any preceding claim wherein the component is a fire damper which is dimensioned so that it can be supported by the sleeve.

4. An integrated mounting and insulating sleeve as claimed in any preceding claim wherein the second flange may be affixed to the outside of the sleeve at a position so that the separation between the first and second flanges corresponds to a desired wall thickness whereby a wall cavity, through which the sleeve penetrates, is substantially completely insulated from the aperture formed when the sleeve is mounted in the wall.

An integrated mounting and insulating sleeve as claimed in any preceding claim wherein the sleeve is manufactured utilising a fire resistant rigid insulating material which may or may not also replace one or both metal surfaces. to 0ong

6. An integrated mounting and insulating sleeve as claimed in any preceding claim wherein the sleeve in conjunction with a fire damper is used in a fire rated, dry wall, floor or ceiling. o

7. An integrated mounting and insulating sleeve as claimed in any preceding claim wherein the sleeve is adapted so that the first and second open ends can be secured lo to ductwork. 0

8. An integrated mounting and insulating sleeve as claimed in any preceding claim wherein the first and second flanges are secured to a first and second wall respectively using dry wall fasteners or the like. -13-

9. An integrated mounting and insulating sleeve substantially as herein described and with reference to the accompanying drawings. DATED this 18th Day of July, 2000 MALCOLM RAVENSCROFT 1996 LIMITED Attorney: STUART M. SMITH Fellow Institute of Patent Attorneys of Australia of BALDWIN SHELSTON WATERS Se