AU745004B2 - Ceiling fire damper - Google Patents

Description

S F Ref: 448930

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

Name and Address of Applicant: Wiljoy Pty Limited Unit 1/65 Old Barrenjoey Road Avalon New South Wales 2107

AUSTRALIA

Spruson Ferguson, Patent Attorneys Level 33 St Martins Tower, 31 Market Street Sydney, New South Wales, 2000, Australia Ceiling fire Damper Address for Service: Invention Title: ASSOCIATED PROVISIONAL APPLICATION DETAILS [31] Application No(s) [331 Country PP1696 AU [323 Application 6 February 1998 Date The following statement is a full description of this invention, including the best method of performing it known to me/us:- 5815 CEILING FIRE DAMPER Field of the Invention Ceiling fire dampers are installed in air-conditioning ducts to prevent the spread of flames and heat during a fire. The dampers are designed to prevent penetrations of fire and heat through the ceiling membrane portion of fire rated floors and ceilings or roof/ceiling assemblies. A main aim of fire dampers is to limit the temperature rise in the plenum space over the ceiling membrane to protect the structural support of the floor or roof construction thereabove. Fire dampers are designed not only to prevent flame spread through air-conditioning ducts for example but to stop radiant heat penetration. A typical 1o installation of a fire damper is shown in Fig. 1 wherein the fire damper 10 is shown installed just above the outlet 40 of air-conditioning duct 11.

Known fire dampers include a pair of pivotally mounted doors which are designed to close upon a certain temperature being reached. The doors are biased into the closed position by a spring. However, upon further heat build-up, the doors can distort and twist, thus at least partially reopening the entry to the duct 11 and allowing the passage of heat, air and radiation therethrough.

~Object of the Invention It is the object of the present invention to provide a fire damper including means to temporarily lock the doors in a closed position during a fire.

Disclosure of the Invention There is disclosed herein an apparatus including: a body to be installed in a duct or at an opening to a duct, the body including a *.passageway therethrough; a door or doors pivotally associated with the body; 25 a biasing element mounted on the door or doors and biasing same toward a closed position across said passageway; a heat actiyated release mechanism adapted to retain the door or doors in an opened position allowing passage of air through the passageway, and to release the door or doors upon build-up of heat, whereupon said biasing element biases the door or doors into the closed position; a locking member attached to or formed integrally with the body and adapted to retain the door or doors in the closed position, and each door or doors being adapted to be moved away from the locking member Ofor resetting in the open position.

[N:\LIBLL]01313:kch [I:\DAYLIB\LIBLL]01313.doe:keh a~i~ i- Preferably, the door includes an insulation panel.

Preferably, two doors are provided, each being pivotally attached to a common hinge member attached to the body.

Preferably, said locking member includes a clip affixed to the body and being elastically deformable to allow an edge of the door to move therepast prior to locking.

Preferably, the door is adapted to be moved away from the locking member for resetting. To this end, said hinge member preferably includes an elongate base having a co-extensive lip extending along a lateral edge thereof, and a beam member being substantially co-extensive with the base and separated from the lip by a gap, the dimension of the gap being similar to the linear extent by which the door must be moved for release from said locking member, and wherein the door includes a tongue passing through the gap and into engagement with the lip, the tongue being adapted to fit loosely through the gap.

By such an arrangement, when the door is in the closed position, it can be s15 linearly shifted to release the same from the locking member prior to resetting into the open position.

Preferably, the hinge member includes a pair of opposed lips between each of which one of said gaps is provided, each being adapted to receive the tongue of one of a pair of doors.

Preferably, the doors include hooks or other handle devices which can be grasped by a user so as to enable the doors to be linearly shifted for release from the locking S.members.

Preferably, the body includes two locking members, one for each door.

However, each door may be associated with more than one locking member. This would 25 depend on the size of the fire damper.

Preferably, the biasing element is a spring connecting one door to the other, the spring being adapted not only to pivotally bias the doors into the closed position, but also to linearly bias the doors away from each and into a position of engagement with said locking members.

Preferably, the spring takes on a serpentine form.

Preferably, the heat activated release mechanism is a tab including first and second parts interconnected by means of solder or other meltable material, each part having an eyelet adapted to be received by a hook associated with one of said doors.

0 [N:\LIBLL]01313:keh [I:\DAYLIB\LIBLL]01313.doc:keh Brief Description of the Drawings A preferred form of the present invention will now be described by way of example with reference to the accompanying drawings, wherein: Fig. 2 is a schematic perspective view of a fire damper with the doors held open, Fig. 3 is a schematic inverted plan view of the fire damper of Fig. 2 with the doors closed, Fig. 4 is a schematic cross-sectional end elevational view of a hinge arrangement for the doors shown in Figs. 2 and 3, and Fig. 5 is a schematic perspective view of a tab.

Description of the Preferred Embodiment In Figs. 2 and 3 of the accompanying drawings there is schematically depicted a fire damper 10. Fire damper 10 is typically fabricated from galvanised mild steel sheets.

Damper 10 includes a body 12 having four sides. Each side has a ledge 31. The four ledges define an opening or passageway through which air can pass when doors 13 are in iI: 15 an open configuration as shown in Fig. 2.

Doors 13 each have affixed thereto a panel of insulation material 23. To one of :the doors there is affixed an extension 24 at the end of which there is received a hook A tab 26 as shown in Fig. 5 is used to retain the doors 13 in the opened configuration depicted. To this end, one of the eyelets 30 of tab 26 is received by the tip of hook whereas the other eyelet is received by a hook 14 secured to the back of the other door.

The tab 26 includes first and second parts 27 and 28 respectively. The parts are formed from galvanised mild steel. The parts 27 and 28 are fixed together by solder 29 which might typically be rated to melt at 165C.

Interconnecting each door 13 is a spring 15. The back of each door 13 has a pair 25 of eyelets 20 through which the end portion of a serpentine spring 15 is received. The o spring 15 pivotally biases the doors 13 into the closed position depicted in Fig. 3. Spring also pushes the doors 13 away from each other.

Riveted or otherwise attached to the inside surface of the walls of the body 12 are clip members comprising a base 22 and opposed clips 21. Clips 21 are an extension of the base 22 and are angularly deviated therefrom. As shown, each door 13 has an upturned edge 32. Edge 32 is adapted to engage with the clips 21 and to be received firmly between the ledge 31 and the clips 21. As the doors 13 close, the edges 32 Relastically deform the clips 21 as they pass thereby.

IO [N:\LIBLL]01313:keh [I:\DAYLIB\LIBLL]01313.doc:keh A special hinge arrangement is shown in Fig. 4. This arrangement includes a hinge base member 16 formed of galvanised mild steel. The base member 16 includes a pair of laterally opposed lips 18. Positioned upon the base member 16 is a beam 17 also typically fabricated from galvanised mild steel. The beam 17 is typically in the form of an inverted U channel having outwardly extending parts as shown. The beam 17 need not be affixed to any other parts of the fire damper.

A gap G exists between the side walls of the beam 17 and the edge of lips 18. A tongue 19, being part of each door 13 passes through the gap G for engagement inside the lip 18. Although the doors 13 are shown in the open configuration in Fig. 4, when in the 1o closed configuration, a degree of movement in the direction indicated by arrow A is allowed by gap G. The dimension of gap G should be similar to the degree by which the clips 21 project from the side wall of body 12. This will enable the doors to be reopened by shifting the doors toward one another in the direction indicated by arrow A.

The hooks 14 secured to the underside of each door 13 can be grasped by a Is person to assist in transferring the doors 13 toward one another for release from the clips 21.

•It should be appreciated that modifications and alterations obvious to those skilled in the art are not to be considered as beyond the scope of the present invention.

For example, where larger fire dampers are required, two or more springs 15 might be provided. Furthermore, the particular arrangement of clips 21 as depicted is exemplary only. For example, similar or alternative clips might be provided closer to the corners of the body 12.

~RAL,

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Claims (8)

1. An apparatus including: a body to be installed in a duct or at an opening to a duct, the body including a passageway therethrough; a door or doors pivotally associated with the body; a biasing element mounted on the door or doors and biasing same toward a closed position across said passageway; a heat activated release mechanism adapted to retain the door or doors in an opened position allowing passage of air through the passageway, and to release the door 0to or doors upon build-up of heat, whereupon said biasing element biases the door or doors into the closed position; a locking member attached to or formed integrally with the body and adapted to retain the door or doors in the closed position, and each door or doors being adapted to be moved away from the locking member i5 for resetting in the open position.

2. The apparatus of claim 1, wherein the door or doors include an insulation panel. V 3. The apparatus of claim 1 or claim 2, wherein two doors are provided, each being pivotally attached to a common hinge member attached to the body.

4. The apparatus of any one of the preceding claims, wherein said locking member includes a clip affixed to the body and being elastically deformable to allow an edge of a respective door to move therepast prior to locking.

5. The apparatus of claim 3, wherein the hinge member includes a pair of opposed lips between each of which one gap is provided, each being adapted to receive 25 the tongue of one of a pair of doors.

6. The apparatus of any one of the preceding claims, wherein the door or doors include hooks or other handle devices which can be grasped by a user so as to enable the door or doors to be linearly shifted for release from the locking members.

7. The apparatus of claim 3, wherein the body includes two locking members, one for each door.

8. The apparatus of claim 3, wherein the biasing element is a spring connecting one door to the other, the spring being adapted not only to pivotally bias the doors into the closed position, but also to linearly bias the doors away from each and into RAL a position of engagement with said locking members. LU [N:\LIBLL]01313:keh 0[I:\DAYLIB\LIBLL]013

13.doc:keh r; YI-= I~CIY~9~LI~I~I~==~ Il~i~ii~-I~Y11~~_ITi~l~i~__*x~ii:~ri-nu~ 9. The apparatus of claim 8, wherein the spring takes on a serpentine form. The apparatus of any one of the preceding claims, wherein the heat activated release mechanism is a tab including first and second parts interconnected by means of solder or other meltable material, each part having an eyelet adapted to be received by a hook associated with one of said doors. 11. An apparatus, substantially as hereinbefore described with reference to the accompanying drawings. 12. The apparatus of any one of the preceding claims being a fire damper. Dated 17 December, 2001 1o Wiljoy Pty Limited Patent Attorneys for the Applicant/Nominated Person SPRUSON FERGUSON o o. olo o S* [N:\LIBLL]01313:keh [I:\DAYLIB\LIBLL]01313.doc:keh ;:=rnir-~ui;.i ^i i.ii x c