HK1097899B - A built-in light fitting for fire preventing - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to a fire-rated recessed downlight.

2. Description of the Prior Art

Conventionally, recessed downlights are fixed in roof, wall or furniture for prettification and illumination. The parts of the roof, the wall or the furniture in which the recessed downlights are fixed are usually made of fire-rated board to avoid spreading of fire. And holes are defined in such parts for fixing the recessed downlights. But most of the present recessed downlights could not avoid spreading of fire and therefore ignite other objects behind the fire-rated board, i.e., central floors such as framework and girder. So the fire-rated board could not effectively avoid spreading of fire and there is a big hidden danger with the conventional recessed downlights. GB-A-2 297 609 discloses a ventilated cover for electric fittings, especially as a downlighter set in a plaster board ceiling, which, in the event of a fire, isolates the fitting from the structure in which it is resist to maintain the fire-resistance thereof. Another downlighter with integral fire-resistant hood is described in GB-A-2 326 467 which comprises a casing for housing electrical connections comprising an integral hood which in case of a fire isolates the light fitting from the ceiling space in which it is mounted in order to prevent or minimize the passage of flames. Other devices or covers for electrical fittings are described in GB-A-2 325 728 , GB-A-2 234 938 . EP 0 909 919 discloses a fire protection cover for an electrical device recessed into a wall or ceiling with one or more support layers coated with one or more layers of intumescent material. A fire protection cover is fabricated by welding or moulding a metal. It is therefore an object of the present invention, to provide an improved fire-rated rescessed downlight. This object is solved by a fire-rated recessed downlight comprsing a mantle inside which a lamp is to be mounted, the mantle having a top and a sidewall, characterised in that it further comprises: a concave formed in the top of the mantle and at least one radiating mouth in the bottom of the concave; a dilatable fireproof piece installed in the concave, the dilatable fireproof piece having at least one radiating aperture corresponding to the radiating mouth, and a cover which covers the dilatable fireproof piece, wherein when fire is present the dilatable fireproof piece will expand rapidly to close the radiating mouth. Further embodiments of the invention are defined in the subclaims.

SUMMARY OF THE INVENTION BRIEF DESCRIPTION OF THE DRAWINGS

FIG 1 is a cutaway view of an example of a downlight;

FIG 2 is a cutaway view of another example of a downlight;

FIG 3 is a cutaway view of a further example of a downlight;

FIG 4 is a cutaway view of a further example of a downlight;

FIG 5 is a cutaway view of an embodiment according to the present invention;

FIG 6 is a cutaway view of a further example of a downlight;

FIG 7 is a cutaway view of a further example of a downlight;

FIG 8 is a cutaway view of a further example of a downlight;

FIG 9 is a cutaway view of another embodiment according to the present invention;

FIG 10 is a cutaway view of a further embodiment according to the present invention;

FIG 11 is a cutaway view of a further example of a downlight;

FIG 12 is a cutaway view of a further example of a downlight;

FIG 13 is a cutaway view of a further example of a downlight;

FIG 14 is a cutaway view of a further example of a downlight;

FIG 15 is a cutaway view of a further example of a downlight;

FIG. 16 is a cutaway view of a further example of a downlight;

FIG 17 is a cutaway view of a further example of a downlight.

DESCRIPTION OF PREFERRED EMBODIMENT OF THEINVENTION

Reference is now made to the drawings.

In order to show the structure expressly, except FIGS. 7, 8, 16 and 17, all the other FIGS omit lamp fittings inside the mantle. Referring to FIG. 1, a fire-rated recessed downlight comprises a mantle having a radiating mouth 4. In order to get an efficient radiation effect, the radiating mouth 4 is usually defined on a top of the mantle. It may also be defined in a sidewall of the mantle. A dilatable fireproof piece 5 is fixed in the radiating mouth 4. Referring to FIG. 6, the dilatable fireproof piece 5 may also be fixed above or below the radiating mouth 4 using a bolt or other means. A radiating aperture 6 is defined in the dilatable fireproof piece 5 corresponding to the radiating mouth 4. In another example, radiating apertures 6' are defined between edges of the dilatable fireproof piece 5 and edges of the radiating mouth 4. In order to improve the radiation ability of the fire-rated recessed downlight, more than one radiating mouth 4 could be defined on the mantle and more than one radiating aperture 6 could be defined on the dilatable fireproof piece 5. Also, in another example, more than one radiating aperture 6' could be defined between the edges of the dilatable fireproof piece 5 and the edges of the radiating mouth 4. Referring to FIGS. 2 and 11, the dilatable fireproof piece 5 could be easily fixed in the taper of the radiating mouth 4. Otherwise, referring to FIGS. 3, 11 and 12, a cover 8 could be fixed above or below the mantle or be embedded in the mantle corresponding to the radiating mouth 4 to prevent the dilatable fireproof piece 5 from being divorced from the mantle. The radiating mouth 4 of the mantle of the fire-rated recessed downlight could help to radiate the heat in ordinary situation and the dilatable fireproof piece 5 will expand rapidly to close the radiating mouth 4 when on fire, therefore the high temperature inside the mantle will not ignite the objects outside it. The dilatable fireproof piece 5 is made of fireproof, fire-rated and dilatable materials, i.e., the CP-25, CS-195 manufactured by American 3M Company or the CPS-AA546 manufactured by American Nelson Company.

A adiabatic piece 13 is formed on the bottom of the mantle. The adiabatic piece 13 is usually formed to be ordinary gasket as shown in FIG. 9 or gasket with a portion extending upwardly along the sidewall of the mantle as shown in FIG. 10 to prevent the high temperature bottom of the mantle from singeing the board adjacent it. The adiabatic piece 13 is made of some ordinary fireproof adiabatic materials, such as aluminum silicate, rock wool and ceramic fiber. The adiabatic piece 13 could also be made of said fireproof adiabatic materials to avoid the flame spreading into the board.

Referring to FIG. 2 and 3, mantle comprises a metallic layer 2 and a fireproof adiabatic layer 3 inside or outside the metallic layer 2. The metallic layer 2 is made of fire-resistant metallic material, such as iron, copper and aluminum. And the fireproof adiabatic layer 3 is made of some ordinary fireproof adiabatic materials, such as aluminum silicate, rock wool and ceramic fiber. The mantle could avoid the fire spreading to the outside and the fireproof adiabatic layer 3 could keep the outside surface of the mantle in a comparatively low temperature so as not to ignite combustible objects around the fire-rated recessed downlight.

Referring to FIG. 4, the mantle comprises two metallic layer 2 and one fireproof adiabatic layer 3 between said two metallic layer 2. Such simple structure could efficiently protect the adiabatic layer 3.

Referring to FIGS. 9 and 10, which show embodiments of the invention, a concave 7 which is hollow in top or bottom is formed in top of the mantle to avoid the dilatable fireproof piece 5 being divorced from the radiating mouth 4. The radiating mouth 4 is in the bottom of the concave 7 where the dilatable fireproof piece 5 is installed in and the cover 8 covers the dilatable fireproof piece 5. Holes corresponding to radiating apertures 6 or 6' are defined in the cover 8. The cover 8 is fastened to the mantle. Referring to FIG 5, which shows another embodiment of the invention, the cover 8 could be mounted contacting the out surface of the mantle. In addition, referring to FIG. 9, the mantle comprises spring clips 10 to fasten the electrical light on the board. Other means could also be used for fastening the mantle.

Referring to FIGS. 7 and 8, a lampshade 11 is fixed in the mantle with at least one lamp holder 1 fixed on it. One lamp holder 1 comprises at least one lamp-house. An outlet hole 9 though which electrical wires are connecting with outside circuit is defined in the mantle. The outlet hole 9 is sealed with antiflaming materials or fireproof materials. Referring to FIG. 17, the electrical wires could also cross the radiating aperture 6 or 6' to connect with the outside circuit.

In addition, the mantle could be defined as following. Referring to FIGS. 13 and 14, the dilatable fireproof piece 5 could be fixed between two layers. And the fireproof adiabatic layer 3 of the mantle could be made of said fire-rated materials and comprises radiating mouth to instead of the radiating mouth of the dilatable fireproof piece 5 as shown in the FIG. 15. Such structure is more ordinary.

Referring to FIG. 16, the mantel could be an ordinary lampshade and the lamp holder 1 could be fixed in the mantle. The said mantel is not just used as an ordinary lampshade, but also a lampshade that is fireproof and adiabatic. Such simple structure could reduce the manufacture cost. Other means could be used to fix the lamp holder 1 in the mantle. In addition, the radiating mouth 4 could be defined to be a counter bore as shown in FIG. 8. The dilatable fireproof piece 5 is inside the counter bore and the cover 8 covers the dilatable fireproof piece 5. With such structure, the fixing process of the dilatable fireproof piece 5 is comparatively easier.

Claims (6)

1. A fire-rated recessed downlight, comprising:

   a mantle (21) inside which a lamp is to be mounted, the mantle having a top and a sidewall,

   characterised in that it further comprises:

   a concave (7) formed in the top of the mantle and at least one radiating mouth (4) in the bottom of the concave (7);

   a dilatable fireproof piece (5) installed in the concave (7), the dilatable fireproof piece (5) having at least one radiating aperture (6) corresponding to the radiating mouth (4), and

   a cover (8) which covers the dilatable fireproof piece (5),

   wherein when fire is present the dilatable fireproof piece (5) will expand rapidly to close the radiating mouth (4).
2. The fire-rated recessed downlight according to claim 1, characterised in that the cover (8) is fixed on the outside of the mantle (21).
3. The fire-rated recessed downlight according to claim 1, characterised in that the cover (8) is fixed on the inside of the mantle (21).
4. The fire-rated recessed downlight according to any one of the preceding claims, characterised in that the radiating mouth (4) of the mantle is aligned with a hole (81) provided in the cover (8).
5. The fire-rated recessed downlight according to any one of the preceding claims, characterised in that the mantle (21) comprises a bottom (12) outwardly extending from the sidewall and an adiabatic piece (13) is fixed on the bottom (12) of the mantle.
6. The fire-rated recessed downlight according to any one of the preceding claims, characterised in that the mantle (21) comprises a metallic layer (2) made of a fire-resistant metallic material such as iron, copper and aluminium.