GB2298055A - Light box on mount having aperture for optical cable - Google Patents

Abstract

A light transmission apparatus 10 comprises a light box containing a light source and power connection 12 on a mounting having an aperture 20 in which is received an optical light transmitting cable 26.

Description

Improvements Relating to Light Transmission Means This invention relates to light transmission means of the type which includes a light transmission optical cable. By an optical cable is intended a fibre optic cable which may comprise a multiplicity of optical fibres grouped in any configuration, or a single large diameter light transmitting rod.

The majority of optical cables are made up of a multiplicity (many thousands) of optical fibres grouped into bundles. In particularly frequently used forms, these bundles are coated with plastic coverings to prevent loss of light and the bundles are used to make what are called fibre optic harnesses. A fibre optic harness comprises a plurality of bundles which are bunched together at one end (the common end) into a single face so that the fibres at that end can be presented to a common light source, whilst the bundles are not so grouped at their other ends, which are left free and become tails". There are various techniques for making these harnesses, but as the method of making the harness forms no part of the present invention, further details are not given herein.However the present invention is particularly germane to enhancing the use of these harnesses, where the invention has its main application, even although the invention can be used more widely as indicated above.

A fibre optic harness is used as will be appreciated, for the transmission and distribution or concentration of light, in that one the one hand, a light source can be positioned at the common end and light will be transmitted along the harness to the tail end of same, effecting distribution of the light. When individual light sources are located at the tail ends the light will be transmitted from the tail ends and concentrated at the common end. The present invention is usable, in relation to its application to fibre optic harnesses, only in relation to transmission and distribution of light.

When a light transmission arrangement is set up, it is usual to make it permanent in that when the harness has been positioned to perform its light distribution function, it is undesirable that its position should not be changed. It is usual therefore to provide that the apparatus to which the common end of the harness is connected should also be fixed, although such apparatus may have cover portions which can be removed to allow access to the light source when it burns out, which is not infrequently so that it can be changed.

Other components of the apparatus which are also liable to require replacement or repair on a relatively regular basis however, tend to remain fixed in position at the location where the light source is located. Examples of such arrangements are set forth in DE 1809739 and DE 3607936.

The present invention provides however a novel arrangement of a light transmission means, for an optical cable, especially but not exclusively a fibre optic harness, whereby the maintenance and repair of the light source and other components is considerably simplified.

According to the invention there is provided An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawings, wherein: Fig. 1 is a perspective view of a light transmission means according to the embodiment of the invention; Fig. 2 is a sectional elevation of the mounting of the light transmission means of Fig. 1; Fig. 3 is a perspective view of the mounting shown in Fig. 2; and Fig. 4 is a sectional elevation of the casing box of the light transmission means of Fig. 1.

Referring to the drawings, in Fig. 1 the assembled equipment is shown and it will be seen that it comprises a box housing assembly 10 which contains electrical components which are supplied with power through an electrical lead 12 connected to the rear side 13 of the assembly 10 through a connector plug 14 (Fig. 4) at one end of the lead 12 and to the mains via a mains plug (not shown) at the other end of the lead 12.

Inside the assembly 10 is a light source 16 (Figs. 2 and 4) which is mounted so as to project its directed beam to and through an aperture 17 in the front side 18 of the assembly.

The aperture 17 is defined by means of a collar 20 carried by the said front side 18 and the collar has a radial bore which receives a locking screw 22 which can be turned to anchor the common end 24 of a fibre optic harness 26, which end 24 is located in the collar 20, as shown. As indicated in Fig. 1, the harness splits into the individual bundles as indicated at 28, and therefore at the opposite end the harness will define the harness tails.

In order to release the harness 26 from the collar therefore, it is simply a matter of loosening the screw 22 and pulling the common end 24 from the collar 20. In practise however, once a harness has been positioned, it is unusual for the position of the common end to require adjustment, although the tails may be adjusted to direct the light issuing therefrom to different locations.

The light source 16 and the related components such as a transformer, 30, printed circuit board 32, and various fuses and the like (not shown) which are required for the driving of the light source and which are contained in the box housing 10 do require from time to time to be removed for replacement and repair. Having regard to the normal location of the assembly for use, it is not always easy to effect removal and or replacement of these components on site.

Prior art systems have not addressed this problem effectively, and the present invention especially in this embodiment, provides an improved arrangement to deal with this problem.

The box housing 10 is made up of two parts which can be separated easily. These two parts are respectively a mounting 40 as shown in Fig. 3, and a box casing 41 as shown in Fig. 4. The two parts fit together by hand operation and no tools are required. The mounting carries the harness common end 24 in the fixed manner described above, and it is fixed to an adjacent surface, by screws which pass through holes 42 in side flanges 44 thereof, so that the assembly will not move in use. The box casing 41 carries all of the other components including the light source 16 and its driving circuit, and can be removed for servicing.

Considering firstly the mounting 40, it comprises an L-shaped metal plate having a base portion 46 and a leg portion 48.

Base portion includes keyhole apertures 50 which form one part of a plug and keyhole connection means by which the mounting 40 and box casing 41 are connected. There are four of such apertures 50, two at each side, and arranged symmetrically on the base portion 46. The collar 20 is carried on the leg portion 48, which forms the front of the box housing 10. The leg portion 48 carries on its inner face magnetic strips which are for holding the box casing 41 firmly but releasably in place.

The box casing 41 is basically a box with an open bottom. It has a front wall 52, a rear wall 54, side walls 56, 58 and a top wall 60. In fact it is double skinned in relation to the top wall 60 in that there is an inner top wall 60A, and in relation to the side walls 56, 58, which have inner skins (not shown) and there are spaces between the skins and walls to enable the flow of air therebetween for cooling purposes.

The front wall 52 has an aperture 62 which aligns with the aperture 17 when the mounting 40 and the box casing 41 are coupled together. The inner skins of the side walls have inwardly turned flanges which carry downwardly depending studs 63 provided with enlarged heads 66. These studs 63 are disposed in similar fashion to the apertures 50 in the base portion 46 of the mounting 40. These studs 63 form the other part of the stud and keyhole connection means.

The box casing 41 finally also carries a focusing lens 68 by which the beam of light from t light source is focused, in use, on the harness common end 24.

When the assembly is operational, as in Fig. 1, the power lead 12 is connected to the box assembly, and the source 16 sends light to the common end 24 of the harness 26, so that the tail ends are illuminated. The magnets 49 abut the front wall 52 on the box casing 41 to hold it to the mounting 40.

When it is required to repair, service or replace the light source or any of the ancillary components, it is simply a matter of pushing the box casing rearwardly so that the front wall 52 is separated from the magnets 49 and until the enlarged heads 64 of the studs align with the large ends of the keyhole apertures 50, so that the box casing 41 can be lifted clear of the mounting and can be taken away to a convenient location for repair or servicing as mentioned above. The box casing 41 is replaced in a similar manner but in the reverse direction.

It can be understood that a particularly convenient arrangement results, and that components can readily be changed and or repaired without disturbing the setting of the harness 26.

By way of modification, the mounting may also carry a heat filter support and the box housing may include a support for a rear reflecting mirror, such as an ellipsoidal mirror.

The two parts of the box assembly may be fitted together in other ways, and there may be a locking catch which can be used to lock the parts together where vibration occurs at the location of use. The fitting together may be snap-fitting, or other arrangement, but in all cases the bringing together locates the light source in the correct position for supplying the light to the fibre optic end.

Claims (10)

1. Light transmission apparatus comprising electrical power connection means, a light source, a box casing containing the light source and power connection means, a mounting by which the box casing is carried, and an optical light transmitting cable of which one end is received in an aperture in the mounting such that light from the light source is received by the said one optical cable end whereby the light can be transmitted by the cable from said one end to the other cable end (or ends in the event that the cable is a multi-tail cable harness) characterised in that the box casing containing the light source and power supply connection is removable as a unit from the mounting.

2. Light transmission means according to Claim 1, characterised in that the casing box is removable and replaceable by hand without the use of any tools.

3. Light transmission means according to Claim 2, characterised in that the casing box is connected to the mounting by stud and keyhole connecting means, whereby the casing box can be removed from the mounting by sliding the casing box relative to the mounting until the stud part of the connecting means aligns with the large section of the keyhole part of the connecting means, enabling the mounting and casing box to be moved apart.

4. Light transmission means according to Claim 3, characterised in that the stud part is on the casing box and the keyhole part is on the mounting.

5. Light transmission means according to Claim 1, 2, 3 or 4, characterised in that the casing box is held to the mounting by magnetic means.

6. Light transmission means according to any preceding claim, characterised in that the mounting is an L-shaped plate, having a base portion and an upstanding leg portion, and the said aperture is in the upstanding leg portion.

7. Light transmission means according to Claim 6, characterised in that the aperture is surrounded by a locking ring having a locking screw disposed radially thereof, which can be tightened to lock the said one cable end to the ring.

8. Light transmission means according to Claim 6 or 7, characterised in that the casing box is open at the front and rear, which are respectively closed by the base portion and the leg portion of the mounting when the casing box is carried by the mounting.

9. Light transmission means according to any preceding claim, characterised in that the light source is removably carried in the casing box by a light source holding bracket.

10. Light transmission means substantially as hereinbefore described with reference to the accompanying drawings.