LIGHTING FITTING

The present invention relates to a lighting fitting. The invention relates particularly, although not exclusively, to a lighting fitting for installation in a panel, for example a downlighter. Downlighters, for installation in ceiling panels, are well known. An existing downlighter is shown in GB 2422191.

When a downlighter is installed in a panel it is desirable that it does not allow moisture and/or other contaminants to pass through the panel via the fitting. Indeed, standards in this respect are set out in British Standard BS 5250-2002, as tested according to BSENl 3141 part 1 -2004.

Most conventional downlighters, of the general form of that shown in GB

2422191, comprise a body which houses a lamp. Part of the body which, in use, extends above a ceiling panel includes ventilation holes to allow heat from the lamp to disperse. However, the ventilation holes also allow moisture and other contaminants to pass through the fitting, from one side of the panel to the other.

To overcome this problem an existing approach is to place an O-ring over the lamp before it is introduced into the fitting. The O-ring is chosen so that when the lamp is inserted into the fitting it forms a seal between the lamp and fitting thus inhibiting passage of moisture and other contaminants from one side of the ceiling to the other via the fitting.

A problem with this approach is that the O-ring can be difficult to fit correctly, and, because of this difficulty, is often omitted entirely.

It is an object of the present invention to address this problem.

According to one aspect of the present invention there is provided a lighting

fitting intended to be installed in an aperture in a panel, the fitting comprising a body for housing a lamp, the body comprising a seal mounting means on which a seal may be mounted, such a seal being operative, when the fitting is used, to form a seal between a lamp mounted in the body and the body thereby to inhibit passage of moisture and/or other contaminants, via the fitting, from one side of a panel in which the fitting is installed to the other.

A seal is preferably mounted on the seal mounting means.

According to another aspect of the present invention there is provided a lighting fitting intended to be mounted in an aperture in a panel, the fitting comprising a body for housing a lamp, the body comprising a seal, the seal being operative, when the fitting is in use, to form a seal between a lamp mounted in the body and the body thereby to inhibit passage of moisture and/or other contaminants, via the fitting, from one side of a panel in which the fitting is installed to the other.

Provision of a seal, or seal mounting means, on the body of the lighting fitting overcomes the problems associated with provision of a separate seal. This leads to better and simpler installation of lamps in lighting fittings whilst ensuring that an effective seal against moisture and other contaminants is maintained.

In one embodiment the lighting fitting is a downlighter. It has a body comprising a side wall to which the seal mounting means is mounted, the seal mounting means being formed separately to the body. The seal mounting means may be arranged to support a seal in a position spaced from the sidewall. The body may be substantially cylindrical into an open end of which a lamp is received. A seal mounting means is provided by a seal mounting ring disposed inside the body. The

seal mounting ring may define a generally radially directed edge, which may be substantially circular. A resilient seal is mounted on the edge of the seal mounting ring. The seal may be formed from a rubber or plastics material. The seal may comprise a U-shaped cross-section such that it can be mounted on the mounting ring by receipt of the edge of the ring into the U. The edge of the ring may be directed radially inwardly or outwardly.

Other embodiments are of course possible. A seal could be affixed to the body of a fitting using any other suitable means, such as an adhesive.

In order that the invention may be more clearly understood an embodiment thereof will now be described, by way of example, with reference to the accompanying drawings of which:

Figure 1 is a part cross-section front view of a downlighter according to the invention installed in a ceiling panel;

Figure 2 is apart cross-section side view of the downlighter of Figure 1; and Figure 3 is a plan view of the downlighter of Figure 1.

In the following the terms top, bottom, side and like terms are used for convenience and refer to the downlighter as shown oriented in the drawings, the orientation in which it is intended to be used, and should not be taken as otherwise limiting. Referring to the drawings, a downlighter, generally 1, is shown installed in an aperture 2 formed in a gypsum ceiling panel 3.

The downlighter 1 comprises a body 4 formed from lmm thick steel and powder coated. The body 4 has a generally cylindrical sidewall, the lower end (as

shown) of which is open, and the upper end of which is closed to form the top 5 of the downlighter. A small generally circular aperture of about 5mm in diameter is formed at or near the centre of the top 5 of the body 4. The aperture allows a pair of insulated electrical wires 7 to enter the body and a plastic grommet 6 is fitted into the aperture to prevent the electrical wires 7 being damaged by the cut edge of the steel top 5 of the body 4 which forms the aperture. The size of the aperture is as small as is reasonably practicable.

The cylindrical wall of the body is substantially continuous, save for the provision of two sets of four ventilation slots 8, the two sets being disposed on respective opposite sides of the cylindrical body. The slots 8 are provided to allow heat generated by a lamp 10 in the body to disperse, and formed by cutting a slit in the cylindrical wall and deforming the wall below the slit inwards. Consequently, for air or other matter to travel from inside the body 4, to outside the body via one of the slots 8 it must travel downwards through the slot, as shown by arrow 9. Each slot extends about 2.5cm around the circumference of the body 4. The slots 8 are all substantially parallel to each other and those of each set are spaced apart from each other by about 8mm. The slots 8 are formed towards the upper half of the body.

Below each set of ventilation slots 8, towards the bottom of the body 4, the cylindrical wall is inwardly deformed between two pairs of parallel generally vertically extending slits 11. These formations enable a flange fitting 12 to be mounted on the body 4 to provide it with an external flange 13 extending around its open end. The flange fitting 12 comprises a cylindrical portion 14, and the flange 13. The cylindrical portion 14 is sized to fit closely inside the cylindrical wall of the body

and comprises two circumferentially extending tongues 15 disposed on opposite sides of the fitting to each other. The tongues 15 are arranged such that when the flange fitting 12 is inserted into the body 4 and then rotated relative to the body the tongues extend through the vertically extending slits 11 passing in front of the inwardly deformed part of the cylindrical wall of the body thereby locking the flange fitting 12 to the body 4.

The flange fitting may be formed from any suitable material, preferably a metal or some other suitably fire resistant material. The lower face of the flange 13 is visible below a ceiling when the downlighter is installed and so its material may be chosen to have a desired appearance. For example it can be formed from brass or may be gold or chrome plated or provided with some other decorative finish. As the flange fitting 12 is formed separately to the remainder of the body 4 any chosen design of flange fitting 12 may be provided, as desired, and flange fittings of different appearance may be used with a common design of steel body. This minimises the amount of potentially relatively costly decorative material required as compared to production of a downlighter body with an integral flange although it will be appreciated that an integral flange could be provided instead.

The flange 13 extends radially outwardly of the cylindrical wall of the body 4, and the free end of the flange turns upwards towards its end. Thus the flange 13 defines a shallow trough. Disposed in the flange are two gaskets. Disposed directly on the flange 13 is a silicone rubber gasket 16. The gasket 16 is stepped, with a thicker region at its outer edge and a thinner region at its inner edge.

An intumescent gasket 17 is disposed over the thinner, inner, part of the

rubber gasket 16. The intumescent gasket 17 comprises cardboard coated on its upper side with an intumescent material, such as expandable granule or powered graphite, or carbon granules.

A lip 24 is formed at the inside of the lower edge of the cylindrical portion 14 of the flange fitting, above which is provided a resilient c-clip 25.

Displaced about 90° around the circumference of the cylindrical wall of the body 4 of the downlighter from the ventilation slots 8 are two further recessed portions 18 over which are mounted brackets 19 supporting pivotally mounted spring clips 20 for retaining the downlighter in a ceiling panel. These clips are of a known form and therefore need not be described further.

Depending from strips of steel 21 affixed to the inside of the recessed portions 18 of the cylindrical wall of the body 4 is a seal mounting ring 22. This ring provides an outwardly facing substantially circular edge, spaced apart from, but generally parallel to, the inside surface of the cylindrical wall of the body. This edge supports a substantially circular flexible seal 23 of U-shaped cross-section with the seal extending into the space between the seal mounting ring 22 and the inside of the cylindrical wall. The seal 23 is formed from silicone rubber, or any other suitable material.

A conventional electrical connector 26 is mounted to the outside of the cylindrical wall by way of a bracket 27 riveted to the cylindrical wall. The electrical wires 7 extend from the connector 26 through the aperture in the top of the downlighter into the downlighter where they are connected to a conventional lamp connector 28.

In use the downlighter is installed into an aperture in a ceiling panel 3. A substantially circular aperture 2 is formed in the ceiling panel 3 just large enough to accommodate the cylindrical body 4 of the downlighter. The spring clips 20 are pivoted upwards so they lie adjacent the cylindrical body 4 and the body inserted into the aperture 3 from below. This causes part of the spring clips 20 to become trapped between the body 4 and the ceiling panel and the remainder of the spring clips to bear upon the top of the ceiling panel urging the body 4 upwards such that the flange 13 is urged towards the lower surface of the panel. This causes the outer, thicker, part of the silicone rubber gasket 16 to be urged against the lower surface of the ceiling panel 3 to form a seal against noise, moisture and other contaminants.

An electrical power supply is connected to the electrical connector 26 in the conventional way.

To install a lamp 10 in the downlighter the lamp connector 28 is first fitted to the lamp. The c-clip 25 is removed from the flange fitting 12 and the lamp inserted into the body of the downlighter and the c-clip 25 replaced. The c-clip 25 retains the lamp 10 in the downlighter and urges it against the seal 23 mounted on the seal support ring 23 forming a seal between the lamp 10 and the inside of the cylindrical wall against noise, moisture and other contaminants.

When the lamp 10 is used, heat generated by the lamp 10 within the body 4 of the downlighter disperses via the ventilation slots 8. The powder coating on the body 4 acts to insulate the steel and thereby keep the external temperature of the body lower than it would otherwise be.

In the event of a fire below the ceiling panel 3 the panel's integrity to fire is (at

least substantially) not impaired by the presence of the downlighter. If the fire heats the intumescent gasket 17 to a sufficient temperature the intumescent material will expand, forming an effective fire-resistant seal between the flange 13, the body 4 of the downlighter and the ceiling panel 3. This inhibits passage of smoke and flame between the downlighter 1 and the panel 3.

If fire enters the body of the fitting (whether or not the lamp 10 remains intact) it is prevented from entering the space above the panel via the ventilation apertures 8 by virtue of the size and configuration of the apertures. The ventilation apertures 8 are narrow, and their configuration requires that flame takes a downward path to exit the fitting. This is found to significantly restrict passage of flame. The aperture for the wires 7, in the top of the downlighter, is sufficiently small to inhibit any significant passage of flame.

The described fitting confers advantages over existing fire resistant downlighters. The size and configuration of the ventilation slots provides for effective ventilation of the fitting whilst sufficiently inhibiting the passage of fire such that the fitting can meet the requirements of BS 476 part 21. The apertures are formed during manufacture of the fitting. No additional intumescent or other materials are required to prevent passage of fire via ventilation apertures in the fitting. This results in a cost saving. Provision of the seal mounting ring greatly facilitates installation of the fitting as compared to conventional fittings when a separate seal must be placed over the lamp before it is inserted into the fitting. This separate seal provides an added complication, may be incorrectly fitted or omitted entirely. This is undesirable.

The above embodiment is described by way of example only. Many variations are possible without departing from the invention.