GB2165344A - Luminaires - Google Patents

Abstract

A luminaire comprises a cold-cathode discharge tube 2 embedded in a moulded block 4 of synthetic resin, which is translucent. An electrical supply is connected via leads 10 to a converter 6, which is connected via leads 8a and 8b to the tube 2. Parts 8'a and 8'b of these leads are also embedded in the block 4. <IMAGE>

Description

SPECIFICATION Luminaires This invention relates to luminaires. As will be known to those skilled in the art, a luminaire comprises a light source and a mounting therefor.

According to one aspect of the present invention, there is provided a luminaire comprising: an electric light source; connection means for making an electrical connection between the light source and an external energy supply; and a body of material in which the light source and at least part of the connection means are encapsulated, the body being at least partially translucent, to emit light from the light source, in use.

Preferably, the light source comprises a discharge tube.

The light source and at least part of the connection means are preferably embedded in a block of said material.

Cold-cathode discharge tubes of long life expectancy are known, and it is envisaged that such may be particularly suited for use in luminaires in accordance with the invention.

A cold-cathode discharge tube may have an envelope (often tubular) of, for example, a giass material, containing electrodes from which electrical connectors emerge through the envelope wall, which latter may be fused to the electrical connectors passing therethrough.

In manufacturing a luminaire embodying the invention, a discharge tube may be surrounded with synthetic resin or other material as an encapsulant in a powder, mobile fluid, or gel state (i.e. before the encapsulant has set) so that the encapsulant makes close contact with the tube and electrical connections therefrom.

The encapsulant is then allowed to set (usually to a hard state, but not necessarily rigid), with the result that the tube and said electrical connections are firmly embedded in a body of moulded material.

Alternatively, the encapsulant may define an internal sealed cavity in which at least part of the tube and its electrical connectors are disposed, spaced from the encapsulant itself.

The encapsulant can be just translucent or transparent, and colourless or coloured. Thus, when the tube is energised and emits light the latter is transmitted through the encapsulant to the exterior of the encapsulating body, where the emitted light can be seen.

Said body may include therein light refiective particles or material, for example light reflecting flakes or beads. If desired, the luminaire may include a light reflecting layer or other light-controlling elements disposed within said body, or applied to an external surface thereof. For example, a parabolic reflector may be used, to focus the light from the light source.

The light source may be of any desired shape, and said body may be moulded into any desired shape.

A discharge tube normally requires an electrical interface device to enable it to be energised from commonly available electrical supplies. Such a device may be mounted within said body or outside it.

The connection means may comprise either direct electrical connections, or induction means for receiving electrical energy transmitted from a remote energy transmitter.

By embedding the light source (and possibly an associated electrical interface device) in an encapsulating body, the light source (and possible interface device) may be afforded mechanical protection. Likewise the electrical connection means may be protected. Further the encapsulating body preferably forms a fluid tight cover. This may have two advantages.

(a) The luminaire may be used outdoors or in a damp environment with reduced risk of water damage to those parts encapsulated in the body. (b) The luminaire may be used in potentially explosive atmospheres with reduced risk of such atmospheres being exposed to sparks or flashes from the encapsulated electrical components.

Luminaires in accordance with the invention may be used for many different functional or decorative purposes. Amongst some of the envisaged uses are outdoor lighting, street lights, traffic signs, advertising and decorative display. The luminaires may be used for emergency lighting for use, for example, in case of fire or electrical mains supply failure. The lights may be mounted in floors, walls or ceilings and may be constructed to form illuminated arrows or pointers indicating an exit rout (for example, the cover may be moulded in the shape of an arrow or pointer). They may be mounted in or serve as substitutes for skirting boards and stair treads, or they may be formed as handrails.

Other uses for the luminaires include mobile applications, such as in vehicles, aircraft, vessels etc., and portable applications such as handlamps and signalling devices.

For a better understanding of the invention and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying diagrammatic drawings, in which: Figure 1 is a perspective view from the front of a luminaire embodying the invention; Figure 2 is a fragmentary perspective view from the rear of the luminaire of Fig. 1; and Figure 3 is a fragmentary perspective view from the rear of another embodiment of the invention.

In the luminaire shown in Figs. 1 and 2, a cold-cathode discharge tube 2 is embedded in a body 4 comprising a moulded block of syn thetic resin. An interface device 6, in this instance formed by a converter, is mounted on one face of the body 4. In this example, the converter 6 is to provide a low current, high voltage, high frequency output. Electrical leads 8a and 8b connect the converter output with electrodes in the tube 2. Portions 8'a and 8'b of these leads adjoining the ends of the tube 2 are also embedded in the body 4. Electrical leads 10 carry the input to converter 6 from a primary source of electrical power, for example, the mains or battery.

In Fig. 3 the same reference numerals as used in Figs. 1 and 2 refer to like parts. In Fig. 3, the moulded resin body 4' is thicker than the block 4 and is moulded over the converter 6 as well as the tube 2. The converter 6 is provided with a heat sink plate 6a exposed to the ambient surroundings at one face of the body 4'. In Fig. 3 the whole of leads 8a and 8b and a portion 10' of the leads 10 adjacent the converter are embedded in the body 4'.

The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification and/or drawings.

Claims (8)

1. A luminaire comprising: an electric light source; connection means for making an electrical connection between the light source and an external energy supply; and a body of material in which the light source and at least part of the connection means are encapsulated, the body being at least partially translucent, to emit light from the light source, in use.

2. A luminaire according to claim 1, wherein the light source and at least part of the connection means are embedded in a block of said material.

3. A luminaire according to claim 1, wherein said body defines an internal sealed cavity in which at least part of the light source and said connection means are disposed, spaced from said material itself.

4. A luminaire according to claim 1, 2 or 3, wherein the light source comprises a discharge tube.

5. A luminaire according to claim 4, wherein the discharge tube is a cold-cathode discharge tube.

6. A luminaire according to claim 4 or 5, including an interface device arranged to supply the tube with electrical energy.

7. A luminaire according to any preceding claim, wherein said body includes therein light reflecting means.

8. A luminaire substantially as hereinbefore described with reference to the accompanying drawings.