FR2782551A1 - LIGHTING REFLECTOR, PARTICULARLY FOR PUBLIC HIGHWAYS - Google Patents

Abstract

The reflector (2) of a street lighting fixture has a concave space (4) between a top (12) and an edge of the lower perimeter (14), the reflector having first and second ends (8, 10) and allowing a light source (6) to be covered by convex optical surfaces (16, 22) located on either side of a plane of symmetry (S), the optical surfaces converging towards the first end of the reflector. It consists of a folded sheet (100) having, at at least part of the optical surfaces, surface elements having curvatures in two perpendicular planes.

Description

The invention relates to a lighting fixture reflector, for example

  for public roads, of the type having a concave space between a top and a lower edge. This space is intended to cover a light source by convex optical surfaces with complex shapes located on either side of a plane of symmetry and which converge towards a first end, generally opposite to that through which is introduced. the light source. The invention also relates to a method of manufacturing the reflector, a body specifically adapted to hold this reflector, and a method of adjusting the surfaces.

  optics of the reflector in the retaining body.

  Current standards with regard to the distribution of the light flux emitted by public lighting luminaires require considerable control over the curvatures of the optical surfaces of their reflector, both in terms of the calculation and the material production of these surfaces. Optical surfaces condition

  notably the luminous imprint of the luminaire on the surrounding ground, the distribution

  tion of the light intensity and the presence or absence of light artifacts

  harmful, such as streaks or spots, on this imprint.

  Indeed, the light footprint must be precisely defined in order to contain the lighting in the desired areas, for example a section of road axis, without sending light flashes to riparian areas. The angular distribution of the intensity emitted by the reflector to produce this imprint must be either uniform or modulated to take into account the distance of the different areas to be illuminated and any ice transmission factors possibly present under the

reflector.

  To meet these requirements, public lighting reflectors are generally made in rigid aluminum form and treated, or plastic or other synthetic resins by molding, using complex techniques to ensure the best degree of precision. in shape and good surface quality. The molding operation must be followed by the deposition of a reflective layer on the concave surface, for example by spraying.

  cathodic, in order to make this surface specular, like a mirror, or diffusing.

  In certain embodiments, it is not possible to form a specular surface due to imperfections which exist either at the level of the surface of the molding part, or in the deposition of the reflective layer. These imperfections are indeed the source of unwanted artifacts. It is then necessary to resort to other techniques aimed at making at least the most critical optical surfaces (generally those located near the lower edges) diffusing, for example by imparting a certain roughness to it during molding. The optical efficiency is thereby reduced, but the reflection of the flux by these diffusing surfaces makes it possible to distribute the flux more uniformly. Whatever the solutions chosen, it turns out that the production of a public lighting reflector by molding and depositing a reflective layer is

  complex and expensive, both in tooling and in manufacturing time.

  There are in areas of quality less demanding lighting

  optics of the reflectors produced by folding one or more sheets of metal.

  In general, the reflectors produced by folding a sheet are intended to cooperate with a longiform light source, such as a discharge lamp. They therefore have an optical surface with curvature around a single axis only, which corresponds to that of the light source. The relatively form

  simple reflector is obtained by winding a sheet.

  By way of example, document FR-A-2 517 805 describes a trough-shaped reflector for a discharge lamp. The shape is produced by bending a precut sheet metal to give it a uniform parabolic section over its entire length. The end walls of the trough are made by sections of this

  sheet metal forming ears folded at right angles during forming.

  It is also known in document FR-A-2 737 281 a reflector, also produced by folding a single sheet, for a fluorescent tube of the "Fluocompact" type. This reflector comprises a first reflecting surface of circular section, the axis of which coincides with that of the tube, and a second surface under the first surface which surrounds an axis perpendicular to that of the tube. The first surface tends to return the light from the fluorescent tube to the second surface which re-emits the flux on the lighting area. It is noted that the first and second reflecting surfaces are distinct both in position and in function, and that each has an optically effective curvature around only one axis. Thus, this type of reflector cannot be envisaged for an application such as public lighting which requires optical surfaces of complex shapes, having elements with curvature around two perpendicular axes, on a

  large part of the useful surface of the reflector.

  According to another reflector embodiment technique described in document FR-A-2 284 820, a series of tongues is produced by cutting a sheet and a succession of transverse folds is made on these tongues so as to obtain a desired curvature . The reflector thus presents a series of planar facets oriented differently along the fold lines. This type of reflector cannot produce a well-controlled light flux since it does not have continuous curved surfaces. In addition, the folds between the facets tend to create unacceptable artifacts for public lighting. In view of these problems, the present invention provides a public lighting luminaire reflector having a concave space between an apex and a lower perimeter edge, the reflector having first and second ends and making it possible to cover a light source with surfaces. optics located on either side of a plane of symmetry, the optical surfaces converging towards the first end of the reflector, characterized in that it consists of a folded sheet having, at at least part of the optical surfaces, surface elements having curvatures in two perpendicular planes. The Applicant has in fact unexpectedly discovered that complex shapes with curvatures in two perpendicular planes can be produced with a quality that is entirely acceptable for the intended application from an initially flat sheet, folded so as to create the shape general of the reflector. Unlike the rolled sheet reflectors of the prior art, the folding of surface elements along two perpendicular planes in accordance with the present invention generates a two-dimensional deformation (stretching

  and / or compression) of the sheet material at the optical surfaces.

  It was initially estimated that this deformation, the degree of which varies as a function of the curvatures, would produce an annoying deterioration in the surface condition of the sheet. Also, in order to avoid the need to produce the optical surface only after the reflector has been formed, which would have required an additional step of depositing a reflective layer, first tests were carried out from a sheet having a surface embossed or bumpy. In fact, like the above-mentioned surface roughnesses, such a surface makes it possible to be less demanding on the quality of the surface state of the reflector, because it distributes the light flux by dispersion to produce a generally homogeneous average lighting, but always

  at the expense of flow accuracy and optical efficiency.

  However, contrary to all expectations, it appeared during experiments that a sheet having a smooth reflecting surface was not subjected to

  damaging damage to its surface due to deformation.

  In this way, the reflector according to the present invention can have good quality smooth optical surfaces, making it possible to achieve efficiency.

high optics.

  Preferably, the sheet is made of thin sheet metal, such as an aluminum sheet less than a millimeter thick. As just explained above, this sheet may have a smooth reflecting surface, the latter being

  for example specular or satin.

  Such a base material, with a good quality reflective surface, is very widely available commercially, being conventionally used in various fields, such as construction. The surface quality is due to the high precision rolling and the treatment during the manufacturing of the material for

  reasons not necessarily dictated by optical considerations.

  In order to prevent the appearance of funny faces or wrinkling during the forming operation, the sheet may have cutouts at or around the optical surfaces, intended to close at least partially during folding. Indeed, the selective removal of material by cutouts makes it possible to accommodate the local surface modification due to the stretching or compression caused by folding along two perpendicular planes. The shape and location of the cutouts can be determined experimentally to ensure that the reflector is completely free of grimaces over its entire optical surface, without leaving too much gap

  between the opposite edges formed by cutouts.

  Advantageously, the cutouts are provided around areas with pronounced bending of the optical surfaces, these being more likely to create a

  wrinkling of the sheet during forming.

  The cutouts may in particular comprise, for each section on either side of the plane of symmetry of the reflector, a first cutout starting from a lower edge located near the first end and ending towards the top, and a second starting from the edge lower near the second end and ending towards the top, the surface portion between these two cutouts forming a side having a general plane substantially parallel to the plane of symmetry of the reflector. Preferably, the shape and the length of the first and second cutouts are provided to allow movement of the sidewall thus formed in a direction substantially perpendicular to the plane of symmetry. This deflection, due to the elasticity of the material at the junction of the sidewall with the top of the reflector, provides two remarkable technical effects: i) it allows the reflector to be properly wedged in position in a retaining body thanks to the force of '' sidewall spacing when these are slightly compressed towards the axis of symmetry and ii) it allows a degree of adjustment of the optical characteristics of the reflector by playing on the approximation or spacing of the sidewalls relative to

the axis of symmetry.

  In a preferred embodiment, the first and second cutouts tend to converge towards the crown portion of the reflector. The separation between the respective termination points of the cutouts defines a zone of junction of the sidewall with the top of the reflector. This zone is preferably located on a part having only a slight curvature in a plane parallel to the plane of symmetry, so as to allow free articulation of the sides on this zone.

during travel.

  The surface portion bordered by the first respective cutouts constitutes a tongue having a general curvature in the plane of symmetry of the reflector between the vertex portion and the lower edge at the level of the first

end.

  In a preferred embodiment, the reflector comprises, at its second end, a flat part, substantially perpendicular to the plane of symmetry, comprising a passage for the light source, this part depending

  from the top of the reflector and being bordered by the respective second cutouts.

  Other cuts can be made to ensure good surface quality. Thus, in a preferred embodiment, the reflector further comprises a third or more cutout, located between the first and second cutouts, starting substantially perpendicularly from a lower edge of the

optical surface.

  This third cut can end at a point set back from the points

  for finishing the first and second cuts.

  The reflector may further include a fourth cut or more

  starting from a first or a second cut.

  Advantageously, the abovementioned cutouts have, at their termination point, two interior edges which meet without forming a sharp angle, the termination point being for example a cutting portion forming a rounded head separating the ends of these two edges . This arrangement avoids

  weaken the reflector material at the cutout end points.

  Due to its sheet structure and cutouts, the reflector has a degree of elasticity in its general shape which favors easy mounting on a luminaire body. It is in particular possible to provide an anchoring of the reflector at its top, preferably by means of a through hole in the plane of symmetry and allowing connection by a cooperating fixing element.

with the luminaire body.

  According to another aspect of the invention, there is provided a luminaire body intended to receive the aforementioned reflector, this body being characterized in that it has bearing surfaces with curvature adapted to that of the surface of the reflector at the points contact and at least one reflector anchoring means allowing

  hold the reflector against these bearing surfaces.

  These bearing surfaces can be shaped so as to at least partially wrap a part of the reflector between two lower edges on either side of the plane of symmetry, in order to prevent deformation of the reflector by

  loosening effect due to its elasticity.

  Preferably, bearing surfaces comprise a series of plates or ribs each having a slice forming a bearing surface for the reflector, each slice having a curvature adapted to that of the reflector to

its contact area with the latter.

  These sections can be substantially perpendicular to the plane of

  symmetry of the reflector, and located between the first end and a point at mid

  distance between the first and second ends.

  In order to exploit the possibilities of optical adjustment thanks to the elasticity of the surfaces of the reflector, the support can be provided with bending means making it possible to apply a controlled clearance on at least part of these surfaces, for example portions having a general plane parallel to the plane of symmetry. This movement can be combined with a modification of the curvature of the optical surface, also having the effect of regulating the return of the light flux. Note that the elasticity of the material means that the deflection actions

  cause a change in the curvature of the reflector, and vice versa.

  The flexing means can comprise at least one element retained by the luminaire body and which can be arranged to press on a part of the external surface of the reflector so as to push it towards the plane of

  symmetry against its elastic force.

  According to a variant, the bending means may comprise a wedge or more of a shape adapted to be inserted between an inner part of the luminaire body and an outer part of the reflector, so as to push the latter towards the plane of symmetry against its elastic force. Optical adjustment is then obtained by choosing shims of appropriate dimensions; thus, one can provide a set of

  shims of different dimensions allowing combinations of adjustment.

  It will be noted that the bending means can also be constituted by the bearing surfaces of the support themselves. For example, the aforementioned plates can be removable with respect to the luminaire body and form part of a set of profiled plates according to different possible curvatures, in order to print on the reflector, at its fulcrum desired curvature

  from a choice of several possible curvatures.

  In a preferred embodiment, the anchoring means comprises a fixing element cooperating with a hole located at a portion of the top of the reflector. The anchoring means can then transmit pressure on all of the bearing surfaces against it by exerting a clamping force from the top against the bottom of the luminaire body. This arrangement makes it possible in particular to require only a single anchor point, for example at the top of the plane of symmetry, to ensure good retention of the reflector in the body. In this way, the reflector is not placed under stress during thermal expansion phenomena. It will be noted that the fixing means can also constitute a bending means by providing a clamping stroke on which the reflector is stressed in elasticity. The curvatures of the reflector are then modified by the pressure exerted by the bearing surfaces as a function of the tightening, which can be interrupted over an adjustment range while ensuring adequate fixing. The present invention also relates to a method for producing a reflector of a public lighting luminaire having a concave space between an apex and a lower perimeter edge, the reflector having first and second ends and making it possible to cover a light source with convex optical surfaces located on either side of a plane of symmetry, the optical surfaces converging towards a first end, characterized in that it comprises the steps consisting in: - providing a sheet of material having at least one reflecting surface , - provide a matrix having a three-dimensional surface corresponding to that of the desired reflector, cut the sheet according to a predetermined contour corresponding to a two-dimensional projection of the surface elements of the desired reflector, and

  - conform the sheet cut on the matrix.

  Advantageously, the die is part of a stamping press.

  In order to avoid excessively pronounced deformations, liable to cause wrinkles or grimaces on the optical surfaces during the step aimed at shaping the sheet, the method can also comprise a step aiming to provide one or more cuts on the sheet. corresponding to the first,

  second, third or fourth aforementioned cuts.

  Finally, the present invention also relates to a method for adjusting the configuration of an optical surface of a reflector housed in its body.

  luminaire, by controlled deformation of this optical surface.

  Other characteristics and advantages of the invention will emerge from the

  following description, given only as an example, as well as drawings

  attached, in which: - Figure I is a perspective view of the reflector according to the present invention, showing all of its interior surfaces, - Figure 2 is a perspective view of the reflector of Figure 1, showing its surfaces external, - Figure 3 is a sectional view of the reflector of Figure 2 along line III-III thereof, - Figure 4 is a plan view of a sheet cut so as to achieve the preform of the reflector Figures 1 and 2, and - Figure 5 is a perspective view of the mounting of the reflector of the

figure I on its holding body.

  As shown in Figures I and 2, the reflector 2 according to the invention consists of a cut and folded sheet forming a concave space 4 for covering a light source 6 (shown in dotted lines). This space 4 is delimited by a set of reflecting optical surfaces between a first and a second end (respectively 8 and 10) of a plane of symmetry S, a vertex 12 and an edge of lower perimeter 14. An opening 16 is provided at the level of the second end 10 to allow passage of the

  light source 6 in the concave space 4.

  The optical surfaces include an elongated part forming a tongue 16 which extends from the part of the apex 12 situated at the second end 10 to the lower edge 14 situated towards the first end 8. This tongue 16 is generally perpendicular to the plane of symmetry S and curved in this plane (Figure 2). It is physically distinguished from the rest of the reflector 2 by cutouts. These comprise, on each side of the plane of symmetry S, a first cutout 18 starting from the lower edge 14 near the first end 8 and also ending at the top 12, and a second cutout 20 starting from the lower edge 14 near the second end 10 and also ending at the level of the vertex 12. The termination points 18a, 20a of the first and second cutouts 18, 20 are separated and aligned in a plane parallel to the plane of symmetry S. On both sides and d 'Other of the plane of symmetry S, the reflector 2 has a flank 22 delimited by the first and second cutouts 18, 20 and the part of the lower edge 14 between these cutouts. Each sidewall 22 has a general plane substantially parallel to the plane of symmetry S and has a concave optical surface facing the plane of symmetry (Figure 1). This surface has curvature elements

  on two perpendicular planes, thus forming a complex optical surface.

  Its function is to directly receive the light flux coming from the light source 6 and to redirect it to the lighting area. In a conventional installation for lighting a passage axis, the reflector is positioned so that the flanking portions 22 direct the light flux towards points distributed in the direction of this axis. Each surface element on this flank 22 directs the flow over a specific area. The flank surface elements close to the apex 12 return the flux towards the base of the reflector, while the elements close to the

  lower edge 14 return the flow to distant points.

  The curvature of the sidewall 22 also conditions the distribution of the intensity of the luminous flux returned to lighting zones. In general, it is desired that the distribution of the intensity of the flux from the reflector 2 takes account of the differences in distance from the illuminated zones and of the possible presence of a protective glass under the reflector, the latter having coefficients of

  transmission which vary according to the angle subtended by the light rays.

  These factors mean that the reflector is designed to accentuate the intensity of the flux at the lower edges 14 which return the luminous flux to distant zones. Although less critical, the optical surfaces located at the part of the

  reflector 2 forming the tongue 16 also have a curvature on two planes perpendicular

  to form a complex surface. In the example, the tongue 16 has, on its optical surface, an enhancement 16a (FIG. 3) along the plane of symmetry S from the second end 10 to the lower edge 14 at the first end. This enhancement 16a divides the curvature of the tongue 16 over

  a section perpendicular to the plane of symmetry S in two curvatures 24a, 24b.

  Each curvature 24a, 24b is provided to send part of the flux towards the lower edge 14 of the adjacent flank 22, in order to reinforce the light intensity on this

portion of the reflector.

  In the example illustrated, the reflector 2 incorporates at its second end 10, between the respective flanks 22, a part forming a flat wall 26, substantially perpendicular to the plane of symmetry S. This wall 26 depends on the top 12 of the reflector and is delimited by parallel edges 26a formed by each of the second cutouts 20. The wall 26 includes the opening 16 to form the passage of the light source 6, this opening being accessible

by the lower edge 14.

  Thus, the first and second cutouts 18, 20 separate, by respective edges, the portions of the assembly of the reflector 2 which comprise the tongue 16,

  the two sides 22 and the flat wall 26.

  The shape and location of the first and second cutouts 18, 20 are calculated to favor the formation of the reflector 2. These cutouts 18, 20 indeed constitute portions of material removed from the material initially in flat sheet, which make it possible to accommodate the convergent movements of surface elements during folding and stretching or compression undergone by the forming of the reflector. The stretching or compression of the material comes in particular from the fact that it undergoes, on surface elements, a double curvature

on perpendicular axes.

  In Figures 1 and 2, which show the free reflector, the first and second cutouts 18, 20 reveal relatively large days, because the different surface portions tend to deviate due to the elasticity of the material. However, these days close almost completely when the reflector

  is mounted and properly held in its holding body.

  It is noted that the first and second cutouts 18, 20 tend to surround areas with strong curvature or with strong curvature transition, their role being to prevent the formation of grimaces or folds on the optical surfaces of the reflector. In some configurations, it may be necessary

  add other additional cuts.

  In the example, there is provided, for each portion of flank 22, a third cut 28 located between the first and second cut 18, 20. This

  third cut 28 leaves perpendicularly from the lower edge 14.

  Each sidewall 22 also comprises a fourth cutout 30 which starts from the second cutout 20 in a direction substantially parallel to the edge of the sidewall II 14. The length of the third and fourth cutouts 28, 30 depends on the curvature or the transition of curvature at the level from their neighborhood. In general, a cut makes it possible to accommodate a convergence of material in a direction perpendicular to its longitudinal development. At their termination point, the first, second, third and fourth cuts have two opposite edges which converge at a small angle to each other. The junction between these two edges is carried out by a small rounded cutout 18a, 20a, 28a, 30a, each edge ending on a different part of the periphery of this cutout. This termination by a rounded cut thus avoids creating a sharp angle between the edges, which would tend to make the material fragile upon tearing. The top 12 of the reflector 2 has a through hole 32 at a midpoint on the plane of symmetry S to allow it to be mounted on its body.

maintenance.

  FIG. 4 shows the preform of a flat part 100 cut out for

  allow to form the reflector of Figures 1 and 2.

  The outer edges of the sheet 100 constitute the lower edges 14 of the reflector 2. The first and second cutouts 18, 20 have opposite sides which are curved and which move away markedly from the central area of the part, which corresponds to the top 12 of the reflector, towards

outer edges.

  The portions of the constitutive surfaces of the tongue 16, of each flank 22 and of the flat wall 16 thus have areas with free edges connected between

  them on four respective sides of the central part constituting the apex 12.

  The sheet 100 thus cut is formed by stamping on a conventional press comprising a concave matrix having the shape and the dimensions of the reflector 2 of FIG. I and 2, and a stamping part having a shape

corresponding convex.

  Various sheet materials can be envisaged to make the reflector. Very good results have been obtained from satin or polished aluminum sheets having a thickness of one millimeter or less. This type of material can be obtained commercially with an excellent surface finish.

  quality, being produced by very high precision rolling mills.

  Figure 5 shows the mounting of the reflector 2 in its holding body.

  This body 40 includes a cradle-shaped housing 42 conforming so as to completely cover the exterior surfaces of the reflector 2. A series of ribs in the form of plates 44a-44f are provided in the part of the housing 42 intended to receive the part of the reflector 2 between its vertex 12 and the first end 8. These plates 44a-44f are aligned perpendicular to the plane of symmetry S 'of the body 40 and have edges 46a-46f forming bearing surfaces for the reflector 2. These edges 36a- 36f are profiled so as to match the curvature of the reflector 2 along the points of contact therewith. The plates 44a, 44b located very close to the first end 8 of the reflector 2 bear only against the part of the reflector forming the tongue 16. On the other hand, those 44c-44f which are more recessed bear not only against the part forming the tongue 16, but also against each respective flank 22. These plates 44c-44f thus make it possible to keep the flank portions 22 constricted in the correct position, opposing their tendency to move apart by loosening due to

the elasticity of the material.

  The plates 44a-f can be either integral with the luminaire body, being for example molded with the latter, or mounted removably with respect to the body

of lighting.

  The housing 42 also includes a set of profiled surfaces 48 on the bottom and on the wall portions towards the outer rim to maintain

  wedged the other contact surfaces of the reflector 2.

  The reflector 2 is anchored in the retaining body 40 by a screw 50

  passing through the opening 32 of the reflector.

  As explained above, it is possible to use the travel offered by the different optical surfaces to adjust the reflector 2. To this end, there is provided a set of jumpers 52 adapted to be fixed on the edge of the plates 44a-f. Each jumper has the shape of a tongue folded over 180 degrees so as to present two opposite faces intended to press respective faces of the plate 44a-f. The folded part is placed on the edge of the plate or of the rib and forms a wedge having the function of locally raising the profile thereof. The jumpers 52 constitute removable elements, possibly adapted to slide on the plates, while ensuring

good immobilization.

  Thus, the selective presence of jumpers 52 on the plates or ribs 44a-f allows, depending on the number and location of the latter, to impose, in a controlled manner, an additional deformation and / or deflection of the reflector 2 The surface portions of the reflector 2 in abutment against a jumper 52 are effectively subjected by the latter to a deformation pressure and / or a deflection force towards the interior of the concave space of the

  reflector according to profile enhancement.

  In the case of a travel imposed by means of jumpers, this comes essentially from a bending at the level of the area of material between the two termination points 18a, 20a of the first and second cutouts 18, 20, forming the junction of the sidewall 22 with the portion of the reflector forming the apex 12. To facilitate bending and avoid excessive distortion at the level of this bending zone, this can be configured to present only a slight

  curvature in the plane of symmetry S of the reflector 2.

  Note that the bending is accompanied by a change in the curvature of the complex optical surfaces of the side 22 of the reflector. The combined action of deflection and modification of curvature then makes it possible to substantially modify the characteristics of light flux distributions of the reflector 2. Of course, it is possible to provide a single jumper 52, or any number

  jumpers arranged to act against different portions of the reflector surface.

  It is in particular conceivable to act also on the part of the reflector 2 forming the

  tongue 16, for example by providing jumpers to the first end 8.

  The jumpers can be replaced by any other known means capable of imposing a controlled clearance on the surfaces of the reflector. It is in particular conceivable to provide shims or pads of various shapes which can be

  lodge in the body of the luminaire opposite the external surface of the reflector 2.

  For example, support elements can be arranged between the plates 44a-f.

  The configuration of the reflector can also be adjusted by means of wedges shaped to be interposed, at predetermined locations, between the exterior surface of the reflector and the body to selectively repel the portions of the reflector as a function of their thickness. A set of shims of different thicknesses

  can thus be provided to allow a choice of setting.

  Furthermore, it is also possible to modify the configuration of the reflector by adjusting the tightening stroke of the fixing screw 50. In this case, the mounting will be provided so that adequate retention of the reflector 2 is established before tightening at rejection of screw 50 in its thread. As the screw is screwed in, the reflector undergoes a deformation at the level of the apex 12 resulting in a controlled modification of its curvatures, in particular of the part forming the tongue.

16.

  The possibility of carrying out a controlled modification of a reflector can also be used when designing or studying it. In this case, the reflector under study is mounted in an adjustment cradle having the function of

  maintain it and have it submit curvature changes.

  By way of example, the adjustment cradle comprises a recess shaped to conform to the exterior surface of the reflector in a normal holding configuration. This recess is made up of surface elements, some of which can be moved forward and backward vis-à-vis neighboring elements. The displacement can be effected by a screwing device, for example a micrometric screw, associated with an adjustable surface element and accessible from the outside. As a variant, the surface forming the recess of the cradle may be in one piece, the adjustment being carried out in this case by simple screws which penetrate inwardly so as to come to bear on different points of the reflector. The

  ends of the screws can optionally be provided with pads.

  Thus, a reflector can be installed on such an adjustment cradle in its basic configuration and subjected to photometric measurements with different curvatures thanks to the adjustment devices. We can then easily determine empirically the optimal curvature for a reflector according to the photometric criteria set. Once this curvature is obtained, the configuration of the cradle is identified by reference to the adjustment positions of the screwing devices. From this data, it is possible to make a reflector support and / or a

  suitable reflector surface configuration.

  It will be noted that this design aid tool can be used not only for reflectors produced by stamping, but more generally with any type of reflector suitable for a controllable local deformation of its

surface by mechanical stress.

  Of course, these various means of adjusting the reflector can be

  implemented individually or in combination.

  The present invention is in no way limited by the example which has just been described. Many variants are possible, both in terms of the choice of sheet material, the initial shape thereof before forming (periphery,

  cutting, drilling, etc.) and imposed bends.

Claims (23)

  1. A reflector (2) for a lighting luminaire, for example for public roads, having a concave space (4) between a top (12) and an edge of the lower perimeter (14), the reflector having first and second ends ( 8, 10) and making it possible to cover a light source (6) with convex optical surfaces (16, 22) situated on either side of a plane of symmetry (S), the optical surfaces converging towards the first end of the reflector, characterized in that it consists of a folded sheet (100) having, at at least part of the optical surfaces, surface elements having   curvatures in two perpendicular planes.   2. Reflector according to claim 1, characterized in that the surfaces optics (16, 22) are smooth.   3. Reflector according to claim 1 or 2, characterized in that it is made from a thin sheet (100) such as a sheet of aluminum less a millimeter thick.   4. Reflector according to any one of claims 1 to 3, characterized   in that the sheet (100) has cutouts (18, 20, 28, 30) at or around the optical surfaces (16, 22) intended to close at least partially when folding.   5. Reflector according to claim 4, characterized in that said cutouts (18, 20, 28, 30) are provided around areas with pronounced bending of optical surfaces (16, 22).   6. Reflector according to claim 4 or 5, characterized in that the cutouts comprise, for each section on either side of the plane of symmetry (S), a first cutout (18) starting from a lower edge (14) located near the first end (8) and ending towards the top (12), and a second cutout (20) starting from the lower edge (14) near the second end (10) and ending towards the top ( 12), the surface portion between these two cutouts forming a sidewall (22) having a general plane substantially parallel to the plane of symmetry (S).   7. Reflector according to claim 6, characterized in that the shape and the length of the first and second cutouts (18, 20) are provided to allow a deflection of the sidewall (22) thus formed in a direction substantially   perpendicular to the plane of symmetry (S).   8. Reflector according to claim 6 or 7, characterized in that the surface portion bordered by the first respective cutouts (18) constitutes a tongue (16) having a general curvature in the plane of symmetry (S) between the crown portion (12) and the lower edge (14) at the first end (8).   9. Reflector according to any one of claims 6 to 8, characterized   in that it comprises, at its second end (10) a planar part (26), substantially perpendicular to the plane of symmetry (S), comprising passages (16) for the light source (6), this planar part depending on the top (12) of   reflector and being bordered by the respective second cutouts (20).   10. Reflector according to any one of claims 6 to 9,   characterized in that it further comprises a third cut or more (28) located between the first and second cut (18, 20), starting substantially   perpendicularly from a lower edge (14) of the optical surface.   11. Reflector according to any one of claims 6 to 10,   characterized in that it further comprises a fourth cutout (30) or more   starting from a first or a second cut (18 or 20).   12. Reflector according to any one of claims 6 to 11,   characterized in that the cutouts (18, 20, 28, 30) have, at their end point (18a, 20a, 28a, 30a), two interior edges which meet without forming a sharp angle.   13. Luminaire body (40) intended to receive a reflector (2) according to   any one of claims 1 to 12, characterized in that it has   bearing surfaces (46a-46f, 48) with curvatures adapted to those of the surface of the reflectors at the contact points and at least one anchoring means (50) of the   reflector for holding the reflector against these bearing surfaces.   14. Luminaire body according to claim 13, characterized in that the bearing surfaces comprise surfaces (36a-36f) shaped so as to at least partially wrap a part of the reflector (2) between two of its lower edges (14 ) on either side of its plane of symmetry (S) in order to prevent   deformation of the reflector by loosening effect due to its elasticity.   15. Luminaire body according to claim 14, characterized in that the bearing surfaces (46a to 46f) are constituted by profiled sections formed on plates or ribs (44a-44f) which depend on the housing (42), each edge having a curvature adapted to that of the reflector at its contact zone with the latter.   16. Luminaire body according to any one of claims 13 to   , characterized in that it comprises flexing means (52a, 52b, 54a, 54b) making it possible to apply a controlled clearance on at least part of the optical surfaces of the reflector (2), for example portions (22) having a map   general parallel to the plane of symmetry (S) of the reflector.   17. Luminaire body according to claim 16, characterized in that the flexing means comprise elements (52) which can be arranged to press on a part (22) of the external surface of the reflector (2) so as to   push it towards the plane of symmetry (S) against its elastic force.   18. Luminaire body according to claim 16 or 17, characterized in that the bending means comprise one or more shims (52) of a shape adapted to be inserted between an interior part of the luminaire body and an exterior part of the reflector ( 2) so as to push it towards its plane of   symmetry (S) against its elastic force.   19. Luminaire body according to any one of claims 15 to   18, characterized in that the plates (44a, 44f) are removable with respect to the luminaire body (40) and form part of a set of profiled plates of different possible curvatures making it possible to impart a curvature to the reflector   desired from a choice of several possible curvatures.   20. Luminaire body according to any one of claims 13 to   19, characterized in that the anchoring means comprises a fixing element (50) cooperating with a hole 32 located at the level of a crown portion (12) of the reflector (2).   21. Method for producing a reflector (2) for a lighting luminaire, for example for public roads, having a concave space (4) between a top (12) and an edge of lower perimeter (14), the reflector having first and second ends (8, 10) and making it possible to cover a light source (6) with convex optical surfaces (16, 22) located on either side of a plane of symmetry (S), the optical surfaces converging on a first end (8) of the reflector, characterized in that it comprises the steps consisting in: - providing a sheet (100) of material having at least one reflecting surface, - providing a matrix having a three-dimensional surface corresponding to that of the reflector, - cutting the sheet according to a predetermined contour corresponding to a two-dimensional projection of the surface elements of the reflector and,   - conform the cut sheet on the surface of the matrix.   22. Method according to claim 21, characterized in that it comprises a step aimed at providing one or more cutouts (18, 20, 28, 30) on the sheet   (100) before conforming it on the matrix surface.   23. Method for adjusting the configuration of an optical surface (16, 22) of a reflector (2) housed in a luminaire body (40), characterized in that it   consists in producing a controlled deformation of this optical surface.