A LIGHT FITTING

FIELD OF THE INVENTION

This invention relates to a light fitting and more specifically to such a fitting which is mounted in the ground, flush into a surface or submerged in water.

BACKGROUND TO THE INVENTION

The ingress of moisture into light fittings is a general problem. Special waterproofing is required for swimming pool lights which remain underwater. The problem is also prevalent where light fittings are mounted in the ground. This type of light will be referred to as an "in-ground light" in this specification. They are known by this name, by at least some of the manufacturers and suppliers, in the lighting industry. Some of these lights are also referred to as "in-ground uplights".

The international standard IEC 60529 classifies the level of protection provided by electrical appliances against penetration by solid objects or dust, accidental contact and water. Those skilled in the art will be familiar with this. The working environment of the specific lights referred to necessitates that they preferably be provided in a casing or fitting which has an IP68 rating under the classification.

Despite the manufacture of fittings with the intention of achieving this rating, water ingress remains a problem.

OBJECT OF THE INVENTION

It is an object of the present invention to provide a light fitting that will at least partially mitigate the mentioned problem.

SUMMARY OF THE INVENTION

In accordance with this invention there is provided a light fitting comprising a light source chamber having a lens, a housing in which the chamber is secured with the lens exposed, and both the chamber and housing respectively sealed against ingress of water.

The invention further provides for the light source to be an array of light emitting diodes (LEDs); for the chamber to be removably securably in the housing; for the chamber to have a flange around the lens which is secured against a corresponding surface on the housing; and for the flange to have a groove for locating a seal.

Further features of the invention provide for the chamber to include a removable component to afford access to the chamber; for the lens to be at least part of a removable wall of the chamber; and for the lens to be secured to a peripheral flange to provide a closure against which both the chamber and housing are secured.

Further features of the invention provide for a cable extending into the housing to be embedded in a settable resin within the housing; and for a cable extending into the chamber to be embedded in a settable resin within the chamber. A

portion of the cable which is embedded will preferably be stripped of its outer insulation sheath.

Further features of the invention provide for the housing to include at least one gland to seal around an electrical cable and for the chamber to also include such a gland.

A further aspect of the invention provides for the chamber and the housing to have at least an IP68 rating respectively. The light fitting will be for an in-ground uplight or a submerged swimming pool light.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described, by way of example only, with reference to the specific embodiments of the accompanying drawings, in which:

Figure 1 shows a perspective view of a light fitting;

Figure 2 shows a plan view;

Figure 3 shows an exploded perspective view; and Figure 4 shows a cross-sectional side view.

DETAILED DESCRIPTION OF THE DRAWINGS

Referring to the drawings, an underwater light fitting (1 ) for a swimming pool light or alternatively for an in-ground light is shown. The fitting (1 ) has an array of LEDs as a light source (2) in an inner chamber (3). The chamber (3) is made of rigid plastics material. The one end (4) of the chamber (3) is open. A lens (5) is fitted over this end (4) to enclose the chamber (3).

The lens (5) is mounted in an annular flange (6). The flange (6) has a composite structure with stainless steel outer (7) and aluminum inner (8) components. The

aluminum is preferably anodized black. Around the opening is a lip (9) which provides a sealing surface (10). The lip (9) has an inner annular groove (1 1 ) for location of a chamber seal (12). The lip (9) is secured to the flange (6) by a series of screws (13). This compresses the seal (12) as required.

The flange (6) has an outer annular groove (14) to locate a seal (15) for an exterior housing (16). The housing (16) is similarly configured to the chamber (3) but made of steel. A lip (17) on the housing is provided with a milled sealing surface (18) which is secured to the flange (6) around the lip (9) of the chamber (3). The housing lip (17) has spaced apart threaded screw holes (19), each of which receive a screw (20) through corresponding holes (21 ) in the flange (6). A second outer seal is thus established. Elastomeric O-rings are used as the inner (12) and outer (15) seals.

The housing (16) is stepped inwardly at (22) towards its closed end (23). The sidewall (24) adjacent this end (23) has a pair of aligned openings (25). Each opening (25) is provided with a cable gland (26). These glands (26) allow a cable (27) to be fed into the housing (16) while maintaining the necessary seal. One cable (27.1 ) will supply electricity to the light source (2) and the other (27.2) is optional for connection to another light, for example. A branch (28) from the supply cable (27.1 ) passes through another gland (29) into the chamber (3) where it is connected through the necessary electrical components (28.1 ) to the LEDs (2).

Once the electrical cables (27) and (28) are fitted, a suitable settable resin (30), such as epoxy, is poured into the housing (16). This sets over the glands (26) and the cables (27) where they extend into the housing (16). Settable resin (31 ) is also poured into the chamber (3) over the gland (29) and cable (28). Further resistance to moisture is provided by so embedding the glands and wiring.

A portion of the branch cable (28) which leads to the chamber (3) will is stripped of its exterior insulation sheath where it extends through the resin (30) in the housing (16). This is not shown, but leaves bare or exposes what is usually three separately insulation wires which are then also embedded in the resin (30). A barrier against moisture penetration which sometimes takes place through capillary action is thus provided across the sheath.

In this manner, a fitting (1 ) which protects the light source with an inner and outer compartment both having an IP68 rating is provided.

Both the housing and chamber can be conveniently accessed. This allows for repair or replacement of the light source. However, in the absence of leaking, this should only have to be done on failure of the LED array (2). Such a light source can last up to 15 years.

Various configurations for providing such a double compartment light fitting will be within the design competence of a person suitably skilled in the art.

It will also be appreciated that the chamber can be a sealed module containing the light source and manufactured with the required water resistance. Such a chamber will be disposable when the light source fails. A transparent panel or lens in the chamber will be aligned with the lens of the housing. Other variations to the described embodiment which remain within the scope of the invention will also be appreciated by someone suitably skilled in the art.