FR2790443A1 - GROUND MARKING DEVICE FOR AEROPORT - Google Patents

Abstract

The invention concerns an airport lighting system embedded in the ground and comprising light sources with light emitting diodes arranged at several levels which associated with a combination of mechanical and optical means enables to provide above-average illumination in outstanding conditions of reliability. The invention is applicable to all types of airport ground lighting systems.

Description

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  LIGHTING DEVICE ON THE GROUND FOR AEROPORT

  The present invention relates to a lighting device included in the ground which can be applied in particular to the marking of runways and airport runways and which presents

  many advantages over previous devices.

  Currently, the airport ground beacons, which must be made in a standardized restricted volume, use one or more light sources combining high-power incandescent lamps, reflectors and prisms, placed in a reinforced housing, to emit flow

  Luminous normalized in one or more directions.

  These devices have the disadvantage of requiring frequent preventive replacement of the lamps to avoid

  failures that would be a danger to aircraft.

  Moreover, said lamps do not make it easy to provide illumination strictly compliant with the required standards without precise positioning of their filaments, positioning difficult to ensure without a tool for measuring illumination. The aging of said lamps does not itself make it possible to guarantee an illumination according to the standards during

long term.

  In addition, the quality of illumination is gradually reduced by pollutions of any kind that are deposited on the outer surface of the prisms, beginning with its lower part. This last point makes compliance with standards very

hard to hold.

  Finally, the efficiency of the lamps is low and this constitutes

  therefore a source of significant energy expenditure.

  By the use of light-emitting diodes judiciously chosen and arranged to realize the light sources, the present invention provides a solution to the problems mentioned above, and which concern the energy saving, the duration of life, the reliability, luminous efficiency and respect for

  lighting standards over time.

  Indeed, by combining the use of light-emitting diodes having various radiation patterns and by periodic cleaning of the prisms, it is possible to best comply with the lighting standards of all kinds of beacons for periods that may exceed 80,000 hours .

  The lifetime of said light-emitting diodes is itself

  even greater than 100,000 hours, which greatly reduces the

risk of failure.

  The diodes may be arranged in such a way that the light emerges mainly through the upper part of the beacon optics, which has the effect of delaying the reduction in efficiency by fouling, and this while strictly respecting the height standards of said beacons relative to

at the level of the tracks.

  A superposition technique of the diodes in several levels, so that the bodies of the diodes of the higher levels constitute an optical element for the light coming from the diodes of the lower levels, makes it possible to increase very significantly the illumination obtained without increasing the surface of

  output that is always limited by the available footprint.

  The invention therefore relates to an airport lighting illuminator of the type comprising: a housing emerging from the ground over a reduced part of its height, at least one light source and preferably two, at least one optical device; of output and preferably two, characterized in that the light source is made by a

  assembly of light-emitting diodes.

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  Embodiments of the invention will be described below.

  FIG. 1 is a presentation of the typical distributions of the light intensity to be provided by an airport beacon. FIG. In principle, in vertical section, a beacon according to the invention. FIG. 3 is a schematic diagram in plan view of the beacon of FIG. 3. FIG. 4 is a presentation of the various possible arrangements of light-emitting diodes in a first variant of the beacon of FIGS. 2 and 3, FIG. 5 is a three-view presentation of an arrangement of the light-emitting diodes in a preferred variant of the beacon of FIGS. 2 and 3, and FIG. 6 is a two-view presentation. a variant of

  the light source of the beacon of Figures 2 and 3.

  Figure 7 is a presentation of a wide-field variant

  of the light source of the beacon of Figures 2 and 3.

  Figure 1 shows five illuminance diagrams to be provided in one direction by the various airport beacons. These diagrams are each characterized by two angular domains, one with high power where the illumination must have a minimum value I and a minimum average value Im, the other at lower power o only a minimum value I is specified. Each of these domains is defined by an angle 'in a horizontal field and by an angle a in a vertical field

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  The five domains are characterized as follows.

  Figure la: Im 2 20 cd for -10 <T 10 and +1 0 w <8 I 2 10 cd for -100 i <100 and +10 w <8% I 2 2 cd for -160 i 16 and +00 < w <13 Figure lb: Im 2200 cd for -3.50 <T 3.50 and +1 0 <w 8 I> 100 cd for -3.50 <i <3.5 and + 1 <w <80 I 20 cd for -4.50 <i <4.50 and +00 <w <130 Figure lc: Im k 100 cd for -19.25 0 <<19.25 and +10! w <10 I 2 50 cd for -19.250 <i <19.250 and +10 <w <100 I k 10 cd for -21.25 0 <T 21.250 and 0 <w <15 Figure ld: Im 2 20 cd for -10 oi < 100 and +1 0 <m <4 I 2 10 cd for -10 il <10 and +1 <m <4 I 2 2 cd for -16 i <160 and +0.5 o <<100 Figure le: Im> 20 cd for -19.25 <T 19.250 and +10 <X <40 I> 10 cd for -19.25 <T <19.25 and +1 0 <<40 I 2 2 cd for -20.50 <T <20.500 and 0.50 <w 100 If the we consider the diagram in Figure lc which presents the illumination diagram requiring the maximum overall power, we see that the field covered represents approximately

  0.1 steradian. The minimum flow to provide is 5 lumens.

  For a conventional filament lamp, this flux corresponds to a light power of about 5.10-2 Watts. In view of the impossibility of obtaining uniform illumination throughout the field with a conventional lamp, the luminous power to be actually supplied is much greater to guarantee the minimum illumination at the edge of the field. The luminous efficiency of the filament lamps being very low, it was therefore necessary to use high-power lamps in the beacons of the prior art. As shown in FIGS. 2 and 3, the beacon according to the invention comprises in particular: a housing 1, made in two parts, a lower part 2 and an upper part 3, at least one, and preferably two light sources , 4 and having an emission axis respectively 34 and 35, - at least one and preferably two prisms, 6 and 7,

  one or more supply circuits 8 and 9.

  The upper part 3 of the casing 1, of generally circular shape and of vertical axis, comprises: - a substantially flat outer ring 10 having an upper surface 17, - a central bulge 11 having an upper surface 12 also substantially flat, shaped elongated, bordered by two large straight sides, - at least one and preferably two openings 13 and 14, located on either side of the central bulge 11, - a central lower recess 15, placed under the central bulge 11, and such it leaves under the surface 12 a sufficient thickness to ensure the mechanical strength of the whole under a heavy load, - near the periphery, a substantially circular lower recess 16, To meet the standards in force, the central bulge 11 is located about 12 mm above the upper surface 17

of the outer crown.

  The openings 13 and 14 are intended to receive the light sources 4 and 5 as well as the prisms 6 and 7. They are inclined preferably symmetrically outwards and comprise two parts: an outer part, respectively 18 and 19 , of relatively rectangular, generally elongated general shape, whose long axis is horizontal, and whose corners are preferably rounded, the rounded part possibly being such that the ends of said openings are semicircular, - an inner part, respectively 20 and 21, also of rectangular general shape, but of smaller dimensions than those of the outer parts 18 and 19, so that a countersink, respectively 22 and 23, constitutes the junction between said two parts 18 and 20 on the one hand, 19 and 21 on the other hand, and forms a kind of open bottom for

the outer parts 18 and 19.

  Each of these two openings opens on the outside of each side of the bulge 11, one of the long sides of their outer portions 18 and 19 forming an edge, respectively 24 and 25, with one of the long sides of said bulge 17, the other two long sides of said outer portions 18 and 19 forming a stop, respectively 26 and 27, with the face

  upper 17 of the outer ring 10.

  Prisms 6 and 7 have an input face, respectively 28 and 29, and an output face, respectively 30 and 31, which form between them an angle α whose dummy edges 32 are substantially parallel to the edges 24 and 25 of the part

upper case 3 1.

  These prisms 6 and 7 are mounted in prism holders respectively 36 and 37, by means of a flexible material 33 so that their input face is substantially perpendicular to the axis of the light source

  respectively, 34 and 35.

  The prism holders 36 and 37 have dimensions such that they are housed in the outer portions, respectively 18 and 19 of the openings 13 and 14, and come to bear on the counterbores 22 and 23 of said openings. They bear, on their periphery, near their bearing face on countersinks 22 - 7 and 23, a groove 38 in which is placed a seal

sealing 39.

  They are fixed to the upper part 3 of the housing 1 by screws 40 and are removable from the outside. They can therefore be replaced to be cleaned or repaired without being

  necessary to get the tag out of its location.

  The sources 4 and 5 are introduced into the inner portions, respectively 20 and 21, of the openings 13 and 14 and fixed by means adapted to the upper part 3 of the

casing 1.

  The inclination has openings 13 and 14 with respect to the horizontal plane thus determines the inclination of the axes 34 and 35 of the sources 4 and 5. This inclination results from an optimization between: the angle f of the prism formed by the two input and output faces of said prism, - the refractive index of the glass constituting said prism, - the inclination of the light beam at the exit b, - the normalized excess of the bulge 11 with respect to the surface of the ground and the minimum thickness of said bulge for

ensure its mechanical strength.

  To obtain the normalized inclination S of the light beam output of 5.5 degrees, the inclination has openings 13 and 14, relative to the horizontal, is between 30 and 40 degrees for an angle 3 of the prism between 25 and 40 degrees and for

  a refractive index of the glass of between 1.4 and 1.85.

  In the preferred embodiment of the invention, the inclination has openings 13 and 14 with respect to the horizontal is substantially equal to 35 degrees with an angle f of prisms substantially equal to 28 degrees and a glass index

  constituting the prism of 1.8.

  The light sources 4 and 5 consist of an assembly of light-emitting diodes 41 which may be of any shape. In the preferred embodiment of the invention, the diodes chosen comprise a substantially cylindrical or elliptical body 42 of axis 43, terminated at one of its ends by a substantially hemispherical or ellipsoidal surface 44 and at the other by a surface substantially plane 45. The light is emitted by a radiating source 66 placed substantially of said hemispherical or ellipsoidal surface 44 from which it leaves in a cone 45 whose shape depends on the construction characteristics of the diode and whose axis 47 is substantially parallel to the axis 43 of the body 42 of said diode. The power supply is by

  connections 48 coming out of the plane face 45.

  The light-emitting diodes 41 can be placed according to

  many arrangements on one or more levels.

  Figure 4 shows the possible arrangements on a level, generally usable arrangements when the light output to be provided for the beacon is not too large compared to the power of the light emitting diodes available. These arrangements may comprise, for example, a single row of at least two diodes, Figure 4a, two parallel rows, side by side, Figure 4b, or nested, Figure 4c. The number of diodes and the number of rows, placed side by side or nested, can be adapted to best fill the available slot and this without departing from the scope of the invention. The light-emitting diodes may be mounted so that they are tangential to one another by generatrices of the cylinders constituting them. They can also be kept apart

  to promote cooling.

  When the available location is too small to obtain the necessary illumination, and in a preferred embodiment of the invention, as shown in FIG.

  light-emitting diodes 41 are arranged on two levels.

  An upper level 49 and a lower level 50 so that the light emitted by the diodes of the lower level passes through a

  space 76 where are the diodes of the upper level.

  The upper level 49 comprises at least one row 77, having an axis 78, and preferably two or more rows, of at least two diodes 41, placed in parallel, two adjacent diodes being separated by a pitch 79, at least equal to their width and preferably less than twice their width, the rows 77 being separated by a center distance 80. The lower level 50 preferably comprises the same number of rows of diodes 81 as the upper level, of at least one diode each and placed below the diodes 41 of the upper level, their axes 78 being substantially superimposed, so that the diodes 81 of the lower level are shifted substantially by half a step 79, along the axis 78, relative to the diodes 41 of the upper level and thus their top 51 is in front of an area 52 where two diodes 41 of the upper level are close or tangent. this arrangement makes it possible to pass the connections 48 of the upper level diodes on each side of an area 53 where the diodes of the lower level are close or tangent. The diodes of the upper level 49 can be chosen with an output beam 56 forming a wide angle y and it is advantageous to use diodes whose output beam is elliptical and to orient them so that the greater width of the beam is substantially parallel to the largest dimension of the field to be covered. The diodes of the lower level 50 are advantageously chosen with a beam of

exit 54 narrower.

  The rays of the beams 54 emitted by the diodes of the lower level 50, enter the diodes of the upper level 49 by their flat portion 45 undergoing a refraction which tends to slightly tighten said beams. These then pass through the diodes of said upper level bypassing the radiating sources 66 of said diodes and emerge by their hemispherical or ellipsoidal portion 44 undergoing a new refraction, much larger than the

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  former. This latter refraction tends to widely spread the rays and create output beams 55 having an angle + similar to the angle y of the output beams 56 of the diodes of the upper level 49. The body 42 and the hemispherical or ellipsoidal end 44 diodes of the upper level thus constitute a complementary optical element for shaping the light emitted by the diodes of the lower level. This arrangement can obviously be applied with any number of rows and any number of diodes on

each of the two levels.

  In the preferred embodiment of the invention, the upper level comprises two rows of diodes having an elliptical output beam covering 70 degrees in width and 30 degrees in height, while the lower level comprises two rows of 14 diodes having a circular beam. covering 15 degrees. In a variant of the preferred embodiment of the invention, as shown in FIG. 6, the diodes 41 are also arranged on at least two levels. The upper level 49 also comprises at least two rows 77 of at least two diodes 41 placed in parallel, FIG. 6a, two adjacent diodes 41 being separated by a step 79 at least equal to their width and preferably less than twice their width. , the rows 77 being separated by a center distance 80. The lower level 50 comprises at least one row 82 of at least one diode 64, offset by half a step 79 along the axis 78 and a half 80 between axis perpendicular to said axis, so that said diode 64 emits the majority of its light in a space 65 delimited by four quarter circles and left free between four diodes 30, 31, 32 and 33 for example, adjacent two This arrangement can be applied with any number of rows of any number of diodes at the higher level. Figure 6b shows the application with three rows at the top level and two at the bottom level. It is obvious that it is possible to place at the lower level a

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  the number of rows of light-emitting diodes equal to or greater than that of the upper level, as shown in

  Figure 6c for example and without departing from the scope of the invention.

  All the diodes of each of the sources are placed in a dust-tight enclosure constituted by a transparent window 78, a wall of substantially rectangular shape 82 and a printed circuit 60 on which said diodes are fixed and soldered. These printed circuits 60 provide the electrical connections and the supply of said diodes. They also make it possible to position and fix the corresponding sources 4 and 5 in the upper part 3 of the casing 1 so that they are placed as high as possible in the inner parts 20 and 21 of the openings 13 and 14, so that that the light they emit comes mainly from the top of the diodes and thus the beacon retains its quality despite the fouling of the lower part of the prisms located closest to the upper surface

17 of the crown 10.

  In a variant of the invention, the printed circuit of one or both sources can be decomposed into two or more planes, three for example, 61, 62 and 63, inclined relative to each other, as shown in FIG. FIG. 7, so as to orient the light-emitting diodes of said source in at least two different directions and thus to provide illumination at an angle x wider than the angles y or

  obtained with a printed circuit board 60.

  The use of a curved molded printed circuit, in the form of a cylinder portion, a sphere portion or any other shape, makes it possible to obtain very varied illumination distributions and therefore to respond easily. to all

  kind of illumination specification.

  Finally, the lower part 2 of the housing 1 is formed of a cylinder 67, of substantially vertical axis, whose end

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  upper 68 is open and whose lower end is

closed by a bottom 69.

  The upper end 68 is surrounded by a crown 70,

substantially horizontal.

  The bottom 69 is arranged to receive a connection connector 71 and, for this purpose, has a bulge 72 adapted

to the connector.

  The crown 70 has on its upper part a circular groove 73 in which is placed a seal 74. This lower portion 2 is fixed by the ring 70 in the circular recess 16 of the upper part 3 of the housing

1 using screws 75.

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Claims (14)

  1. An airport ground lighting device of the type comprising: a housing (1) emerging from the ground over a reduced portion of its height, at least one light source and preferably two (4 and), at least one optical output device and preferably two (6 and 7), characterized in that the light source is made by a   assembly of light-emitting diodes (41).   Airport ground lighting device according to claim 1, characterized in that the light-emitting diodes (41) constituting each light source are distributed over at least two levels, an upper level (49) and a lower level (50). ), so that the light emitted by the diodes of said lower level passes through a space (76) of the level   upper occupied by the diodes placed on said level.   Airport ground lighting device according to claim 2, characterized in that each level of diodes comprises at least one row (77), having an axis (78), of light-emitting diodes and preferably several rows placed side by side. dimension and having between them a center distance (80), each row of the upper level having at least two diodes (41) and preferably several placed substantially side by side and aligned with a pitch (79) at least equal to the width of a diode and preferably less than twice this width, each row of the lower level having at least one diode (81) and preferably several also placed substantially side by side and aligned with a pitch substantially equal to the pitch (79) of the diodes (41) of the upper level, at least one row of the lower level being placed under a row of the upper level, with an offset along the axis (77) substantially equal to half a step (80), at least one row of the lower level - 14 -   being placed under a row of the upper level, their axes (78) thus being substantially superimposed, with an offset along said axes (78) substantially equal to half a pitch (79) so that a beam (54) of light emitted by a diode of this row from the lower level passes through an area (52) where two diodes of the upper level are near and preferably tangential, a portion of said light entering at least one of said diodes, by a plane face (45 ) forming one of the two ends of said diode, and emerging through the other end (44).   Airport ground lighting device according to claim 2, characterized in that each level of diodes comprises at least one row of light-emitting diodes and preferably several rows placed side by side and having between them a center-line (78). ), each row (77) of the upper level (49) having at least two diodes (41) placed substantially side by side and aligned with a pitch (79) at least equal to the width of a diode and preferably less than two this width, each row (82) of the lower level (50) having at least one diode (64) and preferably several also placed substantially side by side and aligned with a pitch substantially equal to the step of the diodes of the upper level, at least a row of the lower level being shifted by half a step (79) parallel to the axis (78) of a row (77) and half a between-axis (80) perpendicular to said axis so that the largest part of the lu emitted by the diodes (64) of the row (82) of the lower level (50) passes into spaces (65) delimited by four diodes of the upper level.   (49), adjacent to each other in pairs (56, 57, 58 and 59).   Airport ground lighting device according to claim 1, characterized in that each source emits in a main direction of emission (34 and 35) making with the horizontal plane an angle of between 30 and 40 degrees and preferably close to 35 degrees. - 15 - 2790443   6. Ground lighting system for airport according to claims 1 and 5,   characterized in that the light emitted by each source is reoriented by an angle prism having a substantially horizontal imaginary edge and that this angle 3 is between 25 and 40 degrees and preferably substantially equal to 28 degrees and that this prism consists of a glass having a refractive index between 1, 4 and 1.85 and preferably close to 1.8.   7. Ground lighting system for airport   according to one of claims 2, 3 or 4,   characterized in that the light-emitting diodes constituting each light source are enclosed in a waterproof enclosure.   8. Ground lighting system for airport   according to one of the preceding claims,   characterized in that each source is off-center with respect to the input face of the corresponding prism so that the emitted light comes out mainly from the upper part said prism.   9. Ground lighting system for airport   according to one of claims 2, 3 or 4,   characterized in that the electroluminescent diodes of the same source are oriented in at least two different directions so as to obtain a wider illumination angle. 10. An airport ground lighting device according to claim 1, characterized in that it emits a luminous intensity defined in two angular domains, one with high power where the illumination must have a minimum value I and a value minimum average Im, the other at lower power o the illumination at another minimum value I, each of these domains being defined by an angle i in a horizontal field - 16 - 2790443   and by an angle w in a vertical field, the values Im and I being defined by: Im> 20 cd for -100 Tq 10 and +10 <u 8 I> 10 cd for -10 il 10 and +1 <u 80 I > 2 cd for -16 i 5 16 and + 0o m 13 11. Airport ground lighting system according to claims 1 and 10,   characterized in that the values Im and I are defined by: Im> 200 cd for -3.5 n T 3.50 and +1 0 w 8 I> 100 cd for -3. 50 R S 3.50 and +1 0 <u 80 I 2 20 cd for -4.5 il 4.5 and +0 w: 13 12. Airport ground lighting system according to claims 1 and 10,   characterized in that the values Im and I are defined by: Im> 100 cd for -19.25 0 n 19.25 and +1 0 w 10 I 2 50 cd for -19.25 0 T 19.25 and + 1S w 10 I 2 10 cd for -21.25o 9 21.25 and +00 w S 15 13. Airport ground lighting system according to claims 1 and 10,   characterized in that the values Im and I are defined by: Im 2 cd for -10 Tq 100 and +1 0 w <4 I> 10 cd for - 10 <T 10 and +1 <M <4 I> 2 cd for -160 <T 16 and +0. 5o w 10 - 17 - 2790443   Airport ground lighting device according to claims 1 and 10,   characterized in that the values Im and I are defined by: Im> 20 cd for -19.25 <q 19.25 and + l <w <4 I 2 10 cd for -19.25 <n T 19.25 and +1 0 w S 4 I> 2 cd for -20. 50 T 20.50 and 0.5 0 w 10