GB2101289A - Lighting apparatus - Google Patents

Abstract

Lighting apparatus for use principally, but not exclusively, in underwater illumination, that is where safety is of paramount importance, consists of a light transmitting cable 4 comprising a bundle of light transmitting fibres, means for providing illumination at one end of the cable and, at the other end, a body 1 of pellucid or translucent material in which the cable is terminated such that the ends 6, 7 of the fibres are fanned out so as to provide illumination from over a considerably large area in relation to the source of illumination and/or the diameter of the bundle of fibres. In the preferred arrangement for underwater use the said body comprises a block of plastics material having a face which is to interface with the water. The cable may enter the block from the rear, or it may enter from a side edge, which arrangement is particularly suitable if the block takes the form of a wall tile. <IMAGE>

Description

SPECIFICATION Lighting apparatus This invention relates to lighting apparatus and in particular, but no exclusively, lighting apparatus for supplying light to an aqueous or underwater environment, for example in swimming pools.

It is a feature of many modern swimming pools that they are lit by underwater lighting. The arrangements used for supplying light in such pools have, hitherto been of fairly conventional form in that they include an electric light bulb located behind a panel set in a wall or floor with an electricity supply cable to a distant power source. Because of the dangers inherent in having an electric circuit proximal water in which people will be swimming it is necessary a) to ensure that the panel behind which the bulb is located is securely sealed against ingress of water from the pool, and b) that the voltage supplied to the bulb is stepped down to only 12 volts. Various safety measures have to be incorporated into the electricity supply circuit to reduce to the minimum the danger to swimmers in the event that the power supply to the light bulbs escapes to the pool.

Broadly speaking a lighting apparatus according to the present invention comprises a) a bundle of light conducting fibres having one end for the reception of light thereinto, b) other end of the bundle being coupled to a body of light transmitting material, the end portions of the fibres at the other end being located within the body at spaced apart locations therein so as to feed light thereinto whereby the body will produce a lighting effect.

The body may be formed of a material which is pellucid or transluscent, or is capable of transmitting light to any degree that produces a desired lighting effect. For instance the body may be of plastics material, for example of a polyester resin or acrylic resin, or may be a liquid oil within a suitable vessel.

Preferably the body is solid e.g. of plastics material, with the separated end portion or at least the free ends of the separated end portions of the fibres embedded therein.

The plastics body may be a panel with a front main face through which a lighting effect is intended to be observed. The main face may be flat (and if so there may be an opposite, back, main face).

The fibres embedded in the panel preferably extend parallel to or normal to the surface of the main face, but may be arranged at any intermediate angle, depending upon the lighting effect desired.

In another arrangement the embedded portions of the fibres extend for most of their lengths parallel to the surface of the main face but the tips of the free ends are bent over so as to be normal thereto whereby light from the tips is transmitted into the panel normally to the main face.

The fibres may be of glass or suitable plastics material.

The apparatus may further include a light generating means for supplying light to the lightconducting fibre bundle. Such light generating means, is envisaged to comprise a chamber, a lamp within the chamber, means for coupling the said one end of the bundle to the chamber so that light generated by the lamp will enter the fibres at said one end, and a reflector for concentrating light from the lamp onto the end faces of the fibres at said one end.

In order that the invention may be more fully understood embodiments in accordance therewith will now be described, by way of example only, with reference to the accompanying drawings, in which: Fig. 1 is a perspective view of a lighting apparatus.

Fig. 2 is a view from in front of the front face of the lighting apparatus of Fig. 1.

Fig. 3 is a front view of another lighting apparatus.

Fig. 4 is a side view of the lighting apparatus of Fig. 3.

Fig. 5 is a front view of another lighting apparatus.

Fig. 4 is a side view of the lighting apparatus of Fig. 3.

Fig. 5 is a back view of yet another lighting apparatus.

Fig. 6 is a side view of the lighting apparatus of Fig. 5.

Fig. 7 is a front view of the lighting apparatus of Fig. 5.

Fig. 8 is a perspective view of a mould which can be used for making a lighting apparatus as shown in the preceding drawings.

Fig. 9 is the end of a fibre bundle equipped with a fitting for forming a secure connection between a light-conducting fibre bundle and a plastics panel to be formed in the mould of Fig. 8.

Fig. 10 is a perspective view of a mould with the light-conducting fibre bundle during the casting of a plastics panel in the mould.

Referring to Figure 1 this shows a lighting apparatus comprising a plastics body 1 having a front portion 2 in the form of a rectangular block and an integrally formed pyrimidal rear or back portion 3.

A bundle 4 of light-conducting fibres has one end 5 thereof embedded in the plastics body being directed with the longitudinal axis of the embedded part approximately normal to the plane of the front face of the portion 2. The bundle enters the body at approximately the summit of the pyrimidal portion 3.

As can be seen in Figure 1 the fibres extend as a bundle only forth short distance within the plastics body. The distance is selected simply so as to provide a firm coupling between the matrix and the bundle.

The end portion 6 of the fibres are separated and directed so that their tips 7 are spaced apart, whereby they will have the effect, when viewed in front of the rectangular block, of supplying light at discrete points (see for example Figure 2).

In the embodiment illustrated in Figure 2 the light conducting fibres are glass fibres arranged as a bundle which is sheathed in a plastics outer covering. The end of the plastics outer covering extends within the plastics matrix and ensures a firm bonding thereto.

Fibre bundles, commercially available, which are suitable for use in our invention comprise e.g., a sheathed bundle of 1,750 fibres, the bundle being 2.2 mm in diameter.

The rectangular block of the plastics body may for example be 22.5 cm square and 1.5 cm deep.

The bodies may be of any shape e.g., star or round shaped, in the form of fish, or circles and so forth.

The bodies may be formed of clear plastics material, but may also incorporate colouring material and other materials, e.g., reflective particles, or chopped glass fibres, to provide desired lighting effects.

The light emitting tips 7 of the light conducting fibres 6 may be arranged in a random order when viewed as in Figure 2, or may be arranged such that selected areas of the body when viewed as in Figure 2 will have a higher density of light emitting tips than other regions, to produce different decorative lighting effects.

Also, if desired, decorative mural effects can be achieved by providing a transparent sheet or film, embedded in the plastics block between the light emitting tips of the fibres and the front main face of the block with thereon e.g. a desired picture, or design or alphabetical letters or zodiac signs and so on.

Referring to Figures 3 and 4 the fibre bundle 20 is connected to a plastics matrix in the form of a flat plate 21, through one of its side faces 22; and as will clearly be seen in Figure 4 the free end portion of the fibres 23 are fanned out within the plate whilst extending generally parallel to the main faces 24,25, of the plate 21. The view from the rear main face 25 of the plate 21 will accordingly be more or less identical to that from the front, i.e., as seen in Figure 3.

The embodiment shown in Figures 5 to 7 is similar to that of the embodiment in Figures 3 and 4 but differs in this respect, that the fibre bundle 30 enters the side 31 of the plate 32 adjacent an edge thereof where the side 31 meets the back or rear main face 33, and the free end portion of the fibres 34 are inclined towards the front main face 35 so that when viewed from in front of the main face 35 the fibres will have the effect of discrete point sources of light or of a stipple effect.

If desired the tips 36 of the fibres 34 can be arranged so as to be more or less normal to the main face 35 of the plate 32, instead of merely inclined at an angle as illustrated.

A suitable material for producing the plastics matrix is a cold curing resin sold by Strand Fibre Glass Limited, of Brentford, under the designation "Resin C." This resin is substantially pellucid when cured. As indicated above, however, various decorative effects can be achieved by incorporating in the body, dyes, chopped glass fibres, glitter, transparent films and so forth, and these can be included for example, during the preparation of the body before the resin has gelled or set.

Referring to Figures 8 to 10, a rectangular moulding box 50 is prepared having a base 51, side walls 52, 53, 54, 55 and being open opposite the base 51. The upper edge of side wall 55 has a recess 56 formed therein for receiving the end of a bundle of light-conducting fibres 57.

Either a sheathed bundle or cable of fibres may well be used or an unsheathed bundle of fibres e.g.

plastics fibres sold under the trade name "CROFON" by E.l. Du Pont; or those sold under the trade name "FIBROFLEX" by T.B. Fibres Limited. In the case of sheathed bundles or cables, the plastics sheathing 60 is stripped at one end and the individual fibres 61 separated and fanned out, as illustrated in Figure 9.

Usually a metal or plastics collar 62 will be slipped over the end of the bundle or cable, e.g.

over the end of the sheath, the collar has an outwardly extending flange 63 which assists in creating a secure connection between the bundle or cable and the plastics body.

The mould 50 is filled to about 1/3rd of its depth, e.g., a 1.5 cm deep mould will be filled to a depth of say 5 mm, with a cold curing resin which is then allowed to gell.

When the resin has gelled but not fully set the end of a cable or bundle of light-conducting fibres e.g. as in Figure 9 is brought to the mould 50 so as to extend through the cut out portion 56 with the flange 63 of the collar 62 located within the mould.

The fibres 61 are fanned out and layed on the surface of the gelled layer and more resin added and the whole casting left to cure, after which the cured resin body is removed from the mould.

A variant of this method is illustrated in Figure 10 in which a mesh grid is arranged within the mould some distance above the base 51. The grid will preferably be of the same material as the resin to be cured in the casting.

The free ends of the fibres 61 are then fanned out and located through the meshes of the grids at the desired locations, and the cable or bundle then brought to the position shown in Figure 10, taking care not to disturb the distribution of the ends of the fibres in the grid, with the collar 63 arranged inside the mould.

The mould is then filled with resin which is allowed to cure, after which the resulting body is removed from the mould.

Although illustrated using a single bundle or cable of fibres it will be appreciated that any number of bundles or cables can be used with an individual body for instance 10 or more. If a plurality of cables or bundles is used they can be enclosed within a "shrink-on" plastics e.g., PVC or other plastics sheathing to protect and/or bind them together: otherwise the arrangement and method for the production of the apparatus will be as described above.

It will be appreciated that dyes, reflective particles or chopped glass fibres and other decorative ingredients may be mixed with the resin before or after it is introduced to the mould.

A transparent film can be included by laying it on a gelled, but not fully cured layer of resin in the mould, before the stage of applying the fibres thereto. Preferably a layer of resin will be introduced over the film before the light conducting fibres are introduced to the mould.

The light receiving end of the bundle or cable of light conducting fibres is polished and terminated in a metal fitting, in a conventional manner. Such fittings can be used in co-operation with other fittings in male/female relationship to enable another length of the cable or bundle of light conducting fibres to be added to the arrangement.

The plastics body can be incorporated in the wall, floor or ceiiing of a building structure, e.g. it may be built into the side or base of a swimming pool, in the manner of tiles normally used therefor, using a suitable waterproof adhesive which will be well known to those skilled in the art of swimming pool construction. The bundle or cable of fibres can be conducted under or above ground to a light source which can be of conventional construction.

We envisage that the light source will be a closed box having a high intensity light source therein e.g. a 250 watt tungsten halogen bulb. The box will be adapted to receive an aforementioned male fitting to lock the light receiving ends of the fibres of the bundle or cable in the required orientation with respect to and from 0 to 60 cm from the light source. A reflector will usually be provided within the box for concentrating light from the bulb onto the light receiving ends of the fibres. The light source will also usually include an arrangement, for example a fan, for cooling purposes in view of the amoutn of heat which is generated.

If desired coloured filters may be incorporated at the light source to provide for hte introduction of coloured light to the plastics body. A suitable arrangement would include single screen between the bulb and the fibre ends on a disc with various coloured screens formed therein individual ones of which could be brought to register with the ends of the firbes by suitable control means from outside the box.

Although described in relation to lighting arrangements for building structures it will be appreciated that apparatus in accordance with the invention is also suitable for use where any mobile light source is required, especially where it is undesirable or difficult to provide electric current up to the point it is required to illuminate.

Claims (14)

1. Lighting apparatus comprising a bundle of continuous light conducting fibres for transmitting light from a remote source to a place of illumination and further comprising a body formed of light transmitting material in which one end of the bundle of fibres terminate, said fibres fanning out so as to be spaced apart from one another at this one end, and said body supporting the ends of the fibres in their spaced apart configuration.

2. Lighting apparatus according to Claim 1 wherein said body has an optical face through which light is transmitted to provide said illumination.

3. Lighting apparatus according to Claim 2 wherein the bundle of fibres enters the body in a direction generally perpendicular to said face.

4. Lighting apparatus according to Claim 2 wherein the bundle of fibres enters the body in a direction generally parallel to said face.

5. Lighting apparatus according to Claim 4 wherein the ends of the fibres are flexed within the body so as to be turned towards the said face.

6. Lighting apparatus according to any preceding claim wherein the body comprises a slab of plastics material.

7. Lighting apparatus to Claim 6 wherein said body incorporates a mesh grid through which the ends of the fibres pass, said grid providing a support for the fibre ends whilst the plastics material is curing.

8. Lighting apparatus according to Claim 6 or Claim 7 wherein the slab of plastics material additionally contains one or more of the following materials: reflective particles, chopped glass fibres, or plastics film.

9. Lighting apparatus according to any of Claims 6 to 8 when appendantto Claim 2, wherein within the slab of plastics material there is provided a transparent or translucent sheet positioned between the ends of the fibres and the said face, on which sheet a decorative effect or information is provided.

1 0. Lighting apparatus according to any preceding claim wherein the said body is formed of pellucid material.

11. Lighting apparatus according to any preceding claim further comprising light generating means arranged at the other end of said bundle of fibres.

12. Lighting apparatus according to Claim 11 wherein the light generating means includes a light concentrating means for concentrating the light from a source onto the ends of the fibres.

13. Lighting apparatus according to Claim 12 wherein the light generating means comprises a halogen lamp and the light concentrating means comprises a light reflecting surface.

14. Lighting apparatus according to any of Claims 11 to 13 wherein the light generating means includes means for providing coloured or multi-coloured lighting.

1 5. Swimming pool lighting apparatus substantially as described herein with reference to the accompanying drawings.