AU2006100341A4 - Fire resistant insulation barrier for light fittings - Google Patents

Description

AUSTRALIA

Patents Act 1990 STEVEN ANGEL BRENDAN DARREN GOW COMPLETE SPECIFICATION INNOVATION PATENT Invention Title: Fire Resistant Insulation Barrier for Light Fittings The following statement is a full description of this invention including the best method of performing it known to us:- Fire Resistant Insulation Barrier for Light Fittings Field of the Invention This invention relates to a fire resistant barrier or guard for light fittings and relates particularly to a guard, or protector, to physically isolate a light fitting from ceiling insulation, and other potentially flammable materials, so as to reduce the likelihood of fire developing or spreading at or adjacent a light fitting, particularly a recessed light fitting.

Background of the Invention Flush mounted and recessed light fittings generate substantial heat in relatively close proximity to potentially flammable material. One example is a flush mounted light fitting in an insulated ceiling installation where such a light fitting protrudes through a hole in the ceiling material and can potentially contact flammable insulating material in the ceiling cavity. Dust from the insulation material may also contact with potentially hot parts of the light fitting thereby giving rise to a potential fire situation.

It is known that low voltage downlights installed in ceilings generate significant heat which may be sufficient to ignite a flammable material that comes into contact with the downlight fitting. Consequently, it is a requirement of most, if not all electrical authorities in Australia and New Zealand to require a fire resistant barrier between any loose insulation in the ceiling and the installed downlight fitting.

However, the cost of commercially available fire proof barriers is substantial and consequently they are rarely used. Instead, it is relatively common practice to simply clear a space around the light fitting. However, this will not necessarily comply with the wiring rules 2000 and 3000 of Australia and New Zealand. Further, ceiling insulation or other material in a ceiling space may be easily moved over time to come into contact with a light fitting thereby obviating any benefit of creating a space around a light fitting.

It is therefore desirable to provide a physical barrier for use with light fittings, particularly downlights, such as low voltage downlights, which at least minimises the likelihood of flammable material contacting the downlight fitting.

It is also desirable to provide a barrier which is cheap and simple to manufacture, transport and install.

It is also desirable to provide a barrier for maintaining a clear space above the ceiling about an installed downlight or flush mounted light fitting to minimise or reduce the potential for fire to develop in the ceiling space.

m:\specifications\500000\504000\504322innovdcc.doc It is also desirable to provide a physical barrier for installation about a light fitting to minimise movement of ceiling insulation material or other material in a ceiling space in close proximity to a light fitting.

It is also desirable to provide a fire resistant barrier adapted for ease of fitting adjacent a ceiling or flush mounted light fitting.

Summary of the Invention In accordance with one aspect of the invention there is provided a fire resistant barrier adapted to be mounted in a ceiling space surrounding and spaced from a light fitting which is installed on or in a ceiling, said barrier comprising one or more walls adapted to extend upwardly from an upper surface of said ceiling, said barrier being formed of paperboard or cardboard treated with or incorporating or coated with a fire retardant.

Preferably, the barrier comprises a box of substantially square or rectangular shape, with or without a top or lid. Alternatively, the barrier may comprise a cylinder with or without a top.

Where a barrier in accordance with the invention is to be used in relation to a low voltage downlight as commonly installed in many business and domestic premises, the barrier is spaced from the light fitting by a distance of from about 50 200 mm.

The height of the barrier wall may be between about 250 300 mm.

In some embodiments, the wall or walls of the barrier are formed with slits to provide ventilation thereby allowing heat to dissipate from within the volume enclosed by the barrier.

The fire retardant, sometimes referred to as "flame retardant", incorporated in or used to treat the paperboard or cardboard barrier may be selected from many hundreds of known fire retardants, the most common of which are polybrominated diphenyl esters (PBDE). However, such fire retardants are thought to be dangerous to human health and, consequently, other fire retardant chemicals, such as those sold under the trade marks "FLAME STOP" or "SAFE-T-GUARD", are preferred, the latter being a water based saturant for cardboard and paper articles. In another embodiment a flame retardant sold under the trade mark "FLAME BUSTERS" may be used The fire retardant material, or chemical, may be coated on the barrier walls, or the barrier material may be infused or saturated or dipped in the fire retardant either before or after forming the barrier structure.

In preferred forms, the barrier is formed of corrugated or laminated cardboard.

m:\specifications\500000\504000\504322innovdcc.doc In order that the invention is more readily understood, embodiments thereof will now be described with reference to the accompanying drawings.

Description of the Drawings Figure 1 is a perspective view of one embodiment of fire resistant barrier in accordance with the invention; Figure 2 is a perspective view of a second embodiment of the invention; and Figure 3 is a perspective view of a third embodiment of the invention.

Description of Preferred Embodiments Referring to Figure 1, one form of fire resistant barrier 12 is illustrated mounted on the upper surface 14 of a ceiling 16. The barrier 12 comprises a substantially rectangular box having side walls 17. The barrier 12 surrounds a downlight fitting 18, and is substantially equally spaced therefrom. Loose insulation material 19, which is potentially flammable, is held away from the downlight fitting 18 by the barrier 12 thereby minimising any fire risk that may be associated with heat generated by the light fitting 18.

The material of the side walls 17 is a corrugated cardboard which has been treated with a fire retardant material, such as a polybrominated diphenyl ester or retardants based on alumina trihydrate or phosphorous-based flame retardants. Many other forms of flame retardants may be used to either saturate or coat the cardboard barrier to thereby reduce surface flame transfer. Other flame retardants include hydrogen chloride which, while being a good flame retardant, forms hydrochloric acid on contact with water, which may be undesirable in a ceiling installation.

The structure of Figure 1 is preferably formed as an integral unit and is transported in a flattened condition thereby minimising transportation costs. The box is then erected on site.

Figure 2 illustrates a second form of the invention in which the barrier is substantially cylindrical, and is formed of a sheet of paperboard or cardboard the opposed edges 21 of which are formed with appropriate slots and tabs so that the edges interlock to maintain the substantially cylindrical shape.

The material of the side wall 17 of this embodiment may be identical to that of the previous embodiment, ie, a paperboard or cardboard material, such as corrugated board, coated or saturated or infused with the flame retardant material.

Referring to Figure 3, the barrier 12 illustrated in this embodiment is similar to that of Figure 1 except that the side walls 17 are provided with a plurality of slots 22.

m:\specifications\500000\504000\5O4322innovdcc.doc In addition, a lid 23 is adapted to be folded down to cover the top of the barrier 12 to thereby fully enclose the downlight fitting 18. The slots 22 provide appropriate ventilation for heat developed by the downlight fitting 18. The lid 23 prevents dust, such as potentially flammable insulation dust or any other material from falling onto the downlight fitting 18.

The invention provides for the first time a highly economical and easily installed safety barrier for use in a wide range of situations where a light fitting is installed within a cavity formed in the ceiling material and protrudes through the ceiling into the ceiling cavity and potentially comes in contact with flammable materials in the ceiling cavity.

The barrier of the invention is readily installed in the ceiling cavity on top of a light fitting installed through the ceiling material.

The barrier is specifically adapted to physically quarantine those parts of the light fitting that have traversed the ceiling material into the ceiling cavity so as to ensure that potentially flammable materials in the ceiling cavity, including loose insulation, wooden construction elements and other potentially flammable material, are physically separated from those parts of the light fitting which have protruded into the ceiling cavity. The barrier of the invention may be sized and dimensioned to provide sufficient space to minimise the impact of any heat generated by the light fitting on the potentially flammable materials in the ceiling cavity and may also be dimensioned to accommodate transformers and other electrical components integral to light fittings for example, in low voltage downlights etc, such that the heat generated from the light fitting per se, in addition to the heat generated by the transformer, are all quarantined and separated from any flammable materials in the ceiling cavity.

The barrier of the invention thereby minimises the chance of any fire occurring in a ceiling cavity as a result of the heat generated by a light fitting or its associated apparatus and whilst the guard of the invention is not designed or intended to limit or stop any fires that may have already started in the ceiling, it does provide a measure of protection and can potentially reduce or slow down the spread of smaller incendiary incidents which may occur in association with the light fitting including sparks and arcing which otherwise may have been sufficient to ignite flammable materials in intimate and close association with the light fitting not protected by the device of the invention.

It will be appreciated that the barrier 12 may be formed of any other shape appropriate to maintain a spacing between a light fitting, such as the downlight fitting m:\specifications\500000\504000\5O4322innovdcc.doc 18, and potentially flammable material, such as insulation material or even building construction material, such as the timber joist 15 shown in Figure 1.

With all embodiments described above, pre-formed weakened areas 24 may be formed in the walls 17, the areas 24 being able to be easily removed as desired to enable electric cables or the like to be run into the light fitting 18.

It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

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Claims (5)

1. A fire resistant barrier adapted to be mounted in a ceiling space surrounding and spaced from a light fitting which is installed on or in a ceiling, said barrier comprising one or more walls adapted to extend upwardly from an upper surface of said ceiling, said barrier being formed of paperboard or cardboard treated with or incorporating or coated with a fire retardant.

2. A fire resistant barrier as claimed in claim 1 wherein the barrier comprises a box of substantially square or rectangular shape, with or without a top or lid.

3. A fire resistant barrier as claimed in claim 1 or claim 2 wherein the wall or walls of the barrier are formed with slits providing ventilation to allow heat to dissipate from within the volume enclosed by the barrier.

4. A fire resistant barrier as claimed in any one of claims 1 to 3 wherein the fire retardant is coated on the barrier walls, or the barrier material may be infused or saturated or dipped in the fire retardant either before or after forming the barrier structure.

5. A fire resistant barrier as claimed in any one of the preceding claims wherein the barrier is formed of a corrugated or laminated cardboard Dated this twenty-seventh day of April 2006 Steven Angel Brendan Darren Gow Patent Attorneys for the Applicant: F B RICE CO m:\specifications\500000\504000\504322innovdcc.doc