GB2167547A

GB2167547A - Lighting system particularly for roads and road tunnels

Info

Publication number: GB2167547A
Application number: GB08527880A
Authority: GB
Inventors: Ornati Lucillo; Stuppaziuni Bruno; Burlon Vincenzo; Bonetti Dario; Comollo Rino; D Amato Antonio
Original assignee: SPEA SpA
Current assignee: SPEA SpA
Priority date: 1984-11-20
Filing date: 1985-11-12
Publication date: 1986-05-29
Also published as: GB8527880D0; FR2573513A1; IT1213248B; IT8423673A0; FR2573513B3

Abstract

This lighting system comprises a light beam diffuser panel (2) for lighting a selected dark area, and a light source (3) emitting a light beam toward the diffuser panel. The diffuser panel (2) is oriented, relatively to the light source (3), so as to diffuse the light beam impinging thereon through the dark area to be lighted. <IMAGE>

Description

SPECIFICATION Lighting system particularly for roads and road tunnels This invention relates to a lighting system which is particularly, but not exclusively, useful in lighting and marking a path to facilitate driving on the road and through road tunnels.

Known are lamps mounted overhead in an area to be lighted, either on specially provided support poles or to the vault of a tunnel to be lighted, and pointing toward the roadway. Such prior lighting systems, owing to their being installed at relatively elevated and far locations from the area to be lighted, have a very high power consumption,since they require a high input of electric and light power. The installation and maintenance of the system components, moreover, tend to be complicated and to cause considerable problems both on account of the lamp distance from the area to be lighted and of such operations interfering with the normal traffic of the area. A very significant example is the instance of road tunnels, where installation and maintenance are causes for slow-downs and hindrance to a smooth traffic, which may even require that the tunnel be temporarily closed.On the other hand, lamps placed above a road are generally apt to lighten the roadway in a tapering fashion from the center out, thereby they do not allow the driver to pick up well the road sides and any incidental obstacles occupying the roadway.

It is the primary aim of this invention to obviate such disadvantages of prior lighting arrangements, by providing a lighting system which, while affording improved overall visibility, can operate on very low power inputs.

Within the above aim, it is a particular object of the invention to provide a lighting system wherein all the system components are normally within man's reach without interfering with the normal operation and traffic of the area served, thus greatly facilitating both the installation and servicing operations.

An important object of the invention is to provide a lighting system which can significantly improve the visibility and driving safety conditions, especially in a road tunnel, by simultaneously serving the functions of tunnel lighting and marking the roadway edges with an optical guide effect.

A not least object of the invention is to provide a lighting system whose components, and especially the ones affected by the light flux, are easy to remove for replacement or cleaning purposes.

The above aim, and these and other objects to be made clear hereinafter, are achieved by a lighting system particularly for roads and road tunnels, characterized in that it comprises at least one light beam diffuser panel for lighting a selected dark area, and a light source emitting a light beam to impinge on said diffuser panel, said diffuser panel being so oriented relatively to said light source as to diffuse said light beam through said selected dark area.

Further features and advantages of the invention will be apparent from the following description of a preferred, but not exclusive, embodiment of the inventive lighting device, as shown by way of illustration and not of limitation in the accompanying drawing, where: Figure 1 is a partly exploded front view of the diffuser panel; Figure 2 is a partly exploded rear view of this diffuser panel; Figure 3 is an enlarged perspective view bringing out a detail of the inventive diffuser panel; Figure 4 is an enlarged perspective view bringing out another detail of the inventive diffuser panel; and Figure 5 is a perspective view of the device according to the invention, as installed to lighten the interior of a road tunnel.

With reference to the drawing figures, the lighting system 1 according to the invention comprises a diffuser panel and a light source, herein designated both generally and respectively with the reference numerals 2 and 3.

The diffuser panel 2 comprises, in turn, a sheet 4, which may be of rectangular shape, with a preferably arcuated top edge 5 extending in a substantially orthogonal direction thereto, the diffusing surface 6 of which sheet, arranged to face the light source 3, is coated with a photoluminescent film and has refractive portions 7.

In the embodiment shown in Figure 1, the diffusive surface 6 has a single refractive portion 7 located at the bottom end of its side edge, or, as shown in Figure 5, the surface 6 may have two refractive portions 7a located in the proximity of its top and bottom ends.

The function of the refractive portion 7 or portions 7a is to enable picking up of the related diffuser panel in case of failure of the associated light source.

The sheet 4 is held substantially vertical on a holding structure 8 which comprises a rod 9 attached to the rest surface at its bottom end 10 and supporting, at the opposite end 11, a backing sheet 12 wherewith a contoured element 13 is associated rigidly. The backing plate 12 is secured on the rod 9 by tightening a collar 14, encircling the rod 9, on a sheet 15 engaging with the countoured element 13, by means of screw bolts 16. With applications proximate to side walls, such as in a road tunnel as shown in Figure 5, a horizontal bar 17 is used which is attached at its ends respectively to the holding structure 8 and to the wall, thereby making the device stiffer.The backing sheet 12 is provided with removable engagement means for retaining the sheet 6 which comprises C-shaped sectional members 18, better shown in Figure 3, and hooking elements 19, better shown in Figure 4, which are fastened, respectively, to opposed vertical edges of the backing sheet 12. More specifically, the sectional members 18 comprise a first flange 20 rigidly associated with a side edge of the backing sheet 12, and a second flange 21 which stands proud and defines a seat 22 engaging peripheral regions of the sheet 6; the hooking elements 19 comprise a first flank 23 attached to the opposite edge of the backing plate with respect to the sectional members 18, and a second flank 24 which carries a hook 25 adapted for insertion through respective slots 26 formed in the sheet 6.

The light source 3 comprises a fluorescent spotlight 27, and in the embodiment shown in Figure 5, a stand 28 secured to the wall 32 of the tunnel; in other applications, a different stand may be anchored instead directly to the floor or the holding structure 8. As shown in Figure 5, when used in a tunnel, the light source 3 would emit a light beam, a first portion whereof directly illuminates a limited area 29 adjoining the light source, whilst a second portion of the beam, which impinges on the diffusive surface 6, is diffused thereby to illuminate a broader area 30 of the roadway.The relative closeness of the light source 3 to the dark area to be illuminated involves but a very low input of light energy, which may be as low as one tenth the value normally employed, for example, while the use of the diffuser panel 2 enables broadening of the zone reached by the light and hence of the illuminated area. The device just described is constructed by securing in the area to be illuminated the holding structure 8 and the stand 28, to which the sheet 4 and spotlight 27 are then attached.According to Applicant's tests, the most satisfactory results have been achieved with the spotlights placed, according to specific applicational requirements, substantially level with either the bottom edge or top edge of the diffusive surface 6, and in any case, at an elevation substantially comparable with that of the panel; the light source-to-panel distance would be correlated to the light beam issuing from the light source, but in general, it would be relatively short. The light source 3 is oriented so as to direct a light beam toward the optically active face 6 of the diffuser panel, which face will then illuminate the area of interest indirectly by light reflection.Specifically, if the lighting device is employed, for example, to lighten tunnels, roads, motorway crossings, subway lanes, and the like, a number of panels 2 would be disposed laterally along the path with the diffusive face 6 substantially vertical and nearly orthogonal to the main path direction, and with several light sources 3 oriented to emit a light beam directed substantially in the travel direction of the nearest lane, in order to prevent dazzling the drivers of oncoming vehicles. Thus, the roadway would be illuminated indirectly by light flowing from one side as reflected by the panels, to provide an excellent effect of edge marking and orientation for the users, while ensuring safe driving and obstacle detecting features.The device maintenance, which mainly consists of periodically cleaning the diffusive face 6 of the panel, can be easily carried out with the exchange method by providing two sets of sheets 4 which would be exchanged mutually at regular intervals. This operation is made simple by the peculiar attachment of the panels removably to the respective supporting structures, and like installation and assembly, in no way interferes with the normal utilization of the lighted area, it being especially advantageous, for example, in tunnels and the like applications.

The invention herein is susceptible to many modifications and changes without deviating from the scope of the inventive concept. Thus, as an example, the diffusive face 6 may be made flat or otherwise configured, e.g. made concave or convex, as appropriate to obtain a sought extent of light diffusion, and in practicing the invention, the materials and dimensions may be any ones contingent on individual requirements. Further, all of the details may be replaced with other technically equivalent elements.

It has been ascertained in actual practice that the lighting device herein disclosed is useful with a variety of applications, which may be connected with transportation but also be, for example, of an industrial or social character. Further simple examples of its applicability to the transportation field may be the suitability of the device, owing to its sharp marking capability, for use in a foggy environment, or at motorway crossings, or parking or service areas. In connection with transportation, it should not be overlooked that the invention may find application in the delimitation of large areas, and to lane marking therein, as well as in the service yards of harbors, airports, customs and military areas, etc. In the field of utilities, the device may find extensive application in the lighting of underground parking sites, subway lanes, emergency lanes for evacuating quickly stadiums and large buildings in general. The device is also useful in the industrial field for delimiting and lighting broad surfaces; for dim lighting overnight and within large plants, warehouses and depots, as well as for marking internal pathways.

Claims

1. A lighting system particularly for roads and road tunnels, characterized in that it comprises at least one light beam diffuser panel for lighting a selected dark area, and a light source emitting a light beam to impinge on said diffuser panel, said diffuser panel being so oriented relatively to said light source as to diffuse said light beam through said selected dark area.

2. A system according to claim 1, characterized in that said at least one diffuser panel comprises a sheet having a diffusive surface and a holding structure with means of releasable engagement for securely holding said sheet.

3. A system according to claim 2, characterized in that said sheet comprises at least one arcuate edge in engagement with said holding structure.

4. A system according to one or more of the preceding claims, characterized in that said means of releasable engagement comprise one or more hooking elements arranged on said holding structure and engaging in slots in said sheet.

5. A system according to one or more of the preceding claims, characterized in that said means of releasable engagement comprise one or more seats in said holding structure engaging peripheral regions of said sheet.

6. A system according to one or more of the preceding claims, characterized in that said diffusive surface has refractive portions.

7. A system according to one or more of the preceding claims, characterized in that said diffusive surface has photoluminescent portions raising the efficiency of said lighting system.

8. A system according to one or more of the preceding claims, characterized in that said light source comprises at least one fluorescent spotlight.

9. A system according to one or more of the preceding claims, characterized in that said light source is located substantially level with one edge of said at least one diffuser panel.

10. A system according to one or more of the preceding claims, as positioned along an edge of a roadway to be lighted, characterized in that said reflective surface of said sheet is laid nearly perpendicularly to the direction of said roadway.

11. A system according to one or more of the preceding claims, as located along an edge of a roadway to be lighted, characterized in that said light source is oriented to substantially direct said light beam in the travel direction of the nearest lane.

12. A lighting system according to one or more of the preceding claims, and substantially as herein described with reference to the accompanying drawings.