GB2317241A

GB2317241A - Fibre optic cable passanger seat lighting

Info

Publication number: GB2317241A
Application number: GB9715867A
Authority: GB
Inventors: Charles Henry Hurst Willis; Christopher Mark Bird; Paul Andrew Timson
Original assignee: Schott Fibre Optics UK Ltd
Current assignee: Schott Fibre Optics UK Ltd
Priority date: 1996-09-12
Filing date: 1997-07-29
Publication date: 1998-03-18
Anticipated expiration: 2017-07-29
Also published as: GB9715867D0; GB9619049D0; DE19733110A1; JPH10186139A; IT1294261B1; GB2317241B; ITRM970527A1; FR2753260B1; FR2753260A1

Abstract

A seat lighting arrangement comprises a light source remote from the vicinity in which illumination is required and a fibre optic cable which transmits light from the source to the desired vicinity, which is typically in front of a passenger in said seat. The cable is routed through the seat and is provided with a connector in a suitable location to which is attached a detachable flex-and-stay type fibre optic extension cable. The extension cable may be easily manipulated by a passenger to provide discreet lighting in a location desired by said passenger and also easily removed for maintenance and repair purposes. The extension cable optionally comprises two parts, a covering sheath and a fibre optic cable thus permitting the removal of the cable from the sheath for replacement or repair of either part.

Description

Improvements relating to lighting means This invention relates to improvements in lighting means, and more specifically to personal lighting means, such as those included in conventional passenger aircraft, luxurious motor vehicles and yachts, trains and other vehicles where there is a requirement for a discreet source of light which may be activated by the user. Such light sources are typically used for reading, writing, mobile computing, playing card and other games, and other pursuits which are generally only undertaken by a single person, and such light sources are hereinafter described as personal light sources.

Although the following discussion and description relates to such light sources as incorporated on commercial passenger aircraft, it is not the intention of the invention to be limited to such application.

Indeed, it is foreseeable that the lighting means of the invention be applied to any of the vehicles described above and others not specifically described.

In modern commercial passenger aircraft, especially those designed for so-called "long-haul" flights, personal lights are incorporated in a mass-produced console unit above each passenger seat on the aircraft. These may be operated by the passenger below by pushing a simple switch usually also in the console, each light being directed towards the particular area of a passenger seat it is intended to illuminate.

Such lights have a number of disadvantages arising mainly from the limited adjustments to the direction and focus of light which can be made by the passenger seated beneath each light. For example, the extent to which a passenger seat may recline is not generally reflected in the extent of possible adjustment of such lights.

Furthermore, the mass produced nature of such lights precludes the use of precision components resulting in a diffuse beam of light which often illuminates passengers in neighbouring seats, which may disturb some passengers.

In response to these disadvantages, there has been developed a modular seat lighting arrangement wherein light from a light source incorporated in each seat is transmitted to the passenger in the seat via a flexible fibre optic light guide, a free end of which the passenger can then manipulate in any desired fashion to illuminate the pages of a book or playing cards etc. more effectively. Dimming and extinction of the light is effected by an optical shutter at the light emitting end of the light guide.

The modular system described above suffers from the serious disadvantage that the light guide, as a result of use, i.e. the repeated manipulation of the said end, deteriorates in performance and has to be replaced. Replacement is difficult as said light guides are usually incorporated in the structure of the seat and this is a serious problem as it is common for aircraft manufacturers to group seats in banks of three as individual structural units. The problem of removal and replacement of a light guide in a single seat is thus exacerbated.

It is an object of this invention to provide a new means of personal lighting in the vehicles mentioned above (and others not specifically mentioned) which does not suffer from the disadvantages of current overhead lighting arrangements, nor from the disadvantages of the modular lighting system described above, and allows greater flexibility of lighting for passengers of such vehicles.

According to the present invention, there is provided light transmission means for illuminating at least one discreet area proximate to a human and remote from an originating light source, said means incorporating a fibre optic cable with one end proximate to the light source, characterised in that a detachable extension cable is connected to the alternate end of the fibre optic cable such that said-extension cable which can be flexed emits light from its free end.

It is preferable that the said fibre optic cable is incorporated in a fibre optic cable harness with a common, light receiving, end and a number of free, light emitting ends corresponding to the number of discreet areas to be illuminated.

It is preferable that the extension cable comprises an outer sheath portion and an inner fibre optic cable portion, said inner cable portion being covered by said sheath portion along the length of the extension cable and removable therefrom to allow for disposal and replacement of either portion.

It is preferable that the extension cable incorporates a large core polymer fibre (LCPF).

It is further preferable that the extension cable be optically connected to the fibre optic cable.

The fibre optic cable harness is preferably provided with a fibre randomising region proximate to the common end to ensure that light is evenly distributed in the fibre optic cables.

It is also preferred that the light emitting end of the extension cable be provided with variable shutter means for dimming and eliminating the light emitting therefrom.

Preferably, the fibre optic cables are incorporated in the seats of a vehicle with the extension cable being connected thereto at a suitable location to allow easy manipulation and adjustment of said extension cable by a passenger occupying said seat.

The common end of the fibre optic harness is preferably provided with light from a primary light source located underneath the seats in which the fibre optic cables are incorporated.

It is further preferable that a contingency light source be provided in conjunction with the primary light source in the event that the primary light source fails, and that in such an event, the fibre optic harness common end be brought into alignment with said contingency light source.

The fibre optic harness common end may be brought into alignment with the contingency light source by various methods including electro-mechanically, electro-magnetically, mechanically, the most preferable of which are electro-magnetic means.

The invention thus provides combines the advantages of a basic modular lighting system for seats as described above with the benefits of using a Large Core Polymer Fibre which is optically connected to one cable of a fibre optic cable harness, which are described below.

Firstly, the reduction in the number of lights required to provide illumination for each seat in an aircraft is reduced, and therefore the overall mass of the aircraft may also be reduced. When the number of commercial journeys and the cost in fuel for each of these journeys is considered, any incremental reduction in weight can prove very valuable to the operator of such an aircraft.

Secondly, in the previous modular seat light arrangement, any contingency light is positioned adjacent the primary light source, and a bifurcated fibre optic end is required which is located with each bifurcated end adjacent each light. The loss in light intensity associated with such bifurcated ends is avoided in the present invention. Furthermore, the physical transport in the invention of the fibre optic harness common end in the event of failure of the primary light source allows the light from either the primary or contingency sources to be focused more precisely on the common end with a resulting increase in the light intensity transmitted in the fibre optic cables.

The ease of replacement of the flexible LCPF sections which are connected to the free end of the fibre optic cables gives the invention a yet further advantage over prior art configurations, especially in the light of the extensive use and abuse such sections to which these section will be subjected by passengers. Also, the flexible LCPF section may be easily changed to conform to the aesthetics of the cabin of the aircraft. This advantage is further enhanced with the facility for removing the inner larger core polymer fibre from the covering sheath provided by the invention.

In the event that either component of the extension cable is worn, and yet the other component remains in serviceable condition, it is necessary to replace only the worn component, thus reducing the overall cost of maintenance.

A specific embodiment of the invention is now described by way of example with reference to the accompanying diagram, wherein: Fig. 1 shows an side elevation of a passenger aircraft seat with a modular lighting arrangement of prior art configuration incorporated therein, and Fig. 2 shows a perspective view of a bank of three seats provided with the lighting arrangement according to the invention.

Referring firstly to Fig. 1, the prior art lighting configuration involves a seat 2 supported by struts 4, 6 which are bolted to the floor of the aircraft cabin (not shown). A light box 8 containing a light 10 is attached to the underneath of the seat 2, such location being most unlikely to inconvenience a passenger using the seat.

The seat 2 is comprised of a seat portion 12, a backrest portion 14, and a headrest portion 16, said backrest portion 16 being inclined at an angle 20 to the vertical for the comfort of the passenger. The said angle 20 is usually variable within certain limits which generally depend on the class (e.g. first, business, economy etc.) in which the seat is located, and such facility is provided for the additional comfort or personal preference of the passenger.

A fibre optic cable 22 is attached to said light box 8, the end 23 of the said cable receiving light from the bulb 10 located within said light box. Also within said light box is located an additional 'backup' light bulb (not shown) which illuminates the end 23 in the event of failure of the first light bulb 10. The end 23 of the fibre optic cable 22 is bifurcated such that equal amounts of light are received by said end when either bulb is illuminated. The fibre optic end therefore receives only a portion of the light transmitted by the either bulb, resulting in a weak intensity of transmitted light within the cable 22.

The cable 22 is attached to the side of the seat 2 by clips 24 such that increases or decreases in the angle of inclination 20 made by the passenger during the flight do not strain or damage said cable. The free end of the cable 25 emits the light transmitted from the bulb 10 to provide localised light for the passenger, and the length of the fibre optic cable 22 which is accessible to the passenger is flexible and manipulable so that the passenger may direct the light as desired. An optical dimmer at the free end 25 allows adjustment of the intensity of the emitted light, which may also be reduced to zero thereby switching the light off.

When not in use, or at the end of a flight, the portion of the cable accessible to the passenger may be flexed into a downward position as shown by the dotted lines 26 in Figure 1, in order that these portions do not prevent any hindrance to passengers leaving their seats for any reasons.

Refering now to figure 2, a row of seats 30, individually referenced at 33,34, 35, which are attached to each other by means not shown and each with features similar to the seat of Figure 1 is provided with a lighting arrangement according to a preferred embodiment of the present invention.

A light box 32 is attached to the underneath of the seat 35, but the said light box need not necessarily be so located. Indeed it may be attached to the underneath of any of the seats shown, to the floor of the aircraft cabin underneath said seats, or in any convenient location as chosen by the installer of the lighting arrangement. A fibre optic cable harness is attached to the light box 32 at its common end, which receives focused light from a primary light bulb 40 mounted within the light box and powered by suitable means. A further contingency light bulb (not shown) may be mounted adjacent said primary light bulb to illuminate the common end 38 of the fibre optic cable harness 36 in the event that the primary light bulb fails.

In such circumstances, the common end is brought into alignment with the contingency light bulb and any associated focusing components by electro-magnetic means (also not shown), thus ensuring maximum transfer of light from the said bulb to the common end 38.

A fibre randomising region (not referenced) is provided in the fibre optic cable harness proximate to the common end to ensure that a uniform intensity of light is transmitted through each of the fibre optic cables.

The embodiment of Figure 2 is shown with three fibre optic cables 42, 44, 46 extending from the common end, but it is foreseeable that more or less cables may so extend therefrom. Indeed the invention may easily be applied to the modular configuration of Figure 1 wherein light sources specific to each individual seat are supplied, and there is thus the possibility of "retro-fitting" the extension cables to prior art lighting arrangement already installed in aircraft.

Each cable is incorporated within the row of seats 30 and is routed to the desired location on each seat requiring a source of localised light as shown in the Figure by dotted lines in the case of cables 42, 44, and full lines in the case of cable 46. The fibre optic cables 42, 44, 46 are terminated at the desired height above the seat portion (see Figure 1) by optical connectors 48, 50, 52, which may be threaded or have other suitable connection means.

Flexible large core polymer fibre (LCPF) cables 54, 56, 58 provided at one end with threaded connectors corresponding to connectors 48, 50, 52 are connected thereto and light is thus transmitted from the end of the fibre optic cables through an optical connector to the LCPF cable. The optical connection ensures maximum light transfer across the connection, therefore optimising the intensity of the light emitted from the free ends 60, 62, 64 of the LCPF cables.

The flexibility of the LCPF cables 54, 56, 58 allows a passenger to adjust a localised light source as desired, and the simple connection of the said cables allows easy replacement should any particular cable become damaged. The LCPF cables are typically protectively coated with cable sheathing plastics material, and have 'flex-andstay' properties as provided by flexible coupling materials which are commonly available, and description thereof is therefore not given here.

The free ends 60, 62, 64 of the said cables are provided with optical dimming means (not shown) similar to those described in the prior art lighting arrangement above.

Claims

1. Light transmission means for illuminating at least one discreet area proximate to a human and remote from an originating light source, said means incorporating a fibre optic cable with one end proximate to the light source, characterised in that a detachable extension cable is connected to the alternate end of the fibre optic cable such that said extension cable which can be flexed emits light from its free end.

2. Light transmission means according to claim 1 characterised in that the said fibre optic cable is incorporated in a fibre optic cable harness with a common, light receiving end and a number of free, light emitting ends corresponding to the number of discreet areas to be illuminated.

3. Light transmission means according to either claim 1 or 2 characterised in that the extension cable comprises an outer sheath portion and an inner fibre optic cable portion, said inner cable portion being covered by said sheath portion along the length of the extension cable and removable therefrom.

4. Light transmission means according to any preceding claim characterised in that the extension cable incorporates a large core polymer fibre (LCPF).

5. Light transmission means according to any preceding claim characterised in that the extension cable be optically connected to the fibre optic cable.

6. Light transmission means according to any preceding claim characterised in that the fibre optic cable harness is provided with a fibre randomising region proximate to the common end.

7. Light transmission means according to any preceding claim characterised in that the light emitting end of the extension cable is provided with variable shutter means.

8. Light transmission means according to any preceding claim characterised in that the fibre optic cables are incorporated in the seats of a vehicle with the free ends located in a suitable position for the connection of the extension cable.

9. Light transmission means according to any preceding claim characterised in that the common end of the fibre optic cable harness is provided with light from a primary light source located underneath the seats in which the fibre optic cables are incorporated.

10. Light transmission means according to any preceding claim characterised in that a contingency light source is provided in conjunction with the primary light source 11. Light transmission means according to claim 10 characterised in that the fibre optic cable harness common end is brought into alignment with said contingency light source on failure of the primary light source.

11. Light transmission means according claim 12 characterised in that the fibre optic cable harness common end is brought into alignment with the contingency light source by electro-magnetic means.

Amendments to the claims have been filed as follows CLAIMS 1. Light transmission means for illuminating at least one discreet area proximate to a human and remote from an originating light source, said means incorporating a fibre optic cable with one end proximate to the light source, and a free end which can be flexed and manipulated by a user and which emits light, characterised in that said free end is readily detachable for replacement.