Patent Description:
Illumination, whether indoor or outdoor, constitutes a fundamental element for guaranteeing safety and visual comfort. The outdoor lighting apparatus known and widely used for road lighting, like lampposts, street light towers, street lights, generally include a supporting pole or bracket, with one end fixed to the ground or to an adjacent construction and the other end destined to sustain a housing for a light source selected, for example, among incandescent light bulbs, high-pressure mercury vapor light bulbs, high- or low- pressure sodium vapor lamps, LED lamps.

The poles must be tall enough to position the light source at a height sufficiently elevated to allow the uniform illumination of the roadway, in total compliance with all legal requirements, and with a section diameter that grants sturdiness and stability to the entire lighting apparatus. More in detail, the law requires that the poles have variable heights according to the type of use, for example heights comprised between <NUM> and <NUM> meters for road and expressway lighting, so that the driver of a vehicle has optimal perception of both the roadway layout and the stopping distance from a potential obstacle present along the traveling lane or on the carriageway.

Although there are still partially widespread obsolete structures made with concrete supports with iron rebar, nowadays the poles are made mainly of steel. As an alternative, the use of fiberglass makes it possible to obtain very lightweight poles that are easily handled, but having larger section diameters and therefore requiring very bulky supports, while the use of aluminum ensures a better guarantee of durability over time and is easier to work with, consequently this material can take on a wide variety of shapes, which is very popular in urban settings, but also implies higher production costs.

The need to position the light source at such a height using these supporting structures constitutes, however, one of the main disadvantages of known lighting apparatus.

Above all, the light source positioned at a considerable height makes the maintenance thereof complex and in some cases dangerous. Indeed, when there is a breakdown or a malfunction of the lighting, a maintenance technician must reach the light source by climbing up the relative supporting pole or using a lift truck, thereby exposing himself to all the dangers that the option selected implies. Moreover, if ever the light source should detach from the supporting pole, for example in an area subject to strong gusts of wind, there is a very serious risk that it strikes either a vehicle or a person with a force directly proportional to its fall.

Secondly, the higher the position of the light source, the greater the probability that, in the presence of rain or fog, one or more dark zones or the so-called veiling luminance may appear on the asphalt, respectively. It is indeed known that the rain settled on the asphalt gives rise to zones that appear black to an observer, in particular where the lighting apparatus, the eye of the observer and the roadway are aligned (i.e. at the critical angle or angle of Brewster), due to the fact that the light is reflected by the road surface outside of the observer's own field of view. The fog and, more specifically, the water vapor particles that constitute it instead have the power to diffuse the light emitted by the light source; this diffused light produces a luminous halo that overlaps the entire observed image, decreasing the contrast and, in the specific case of roads and expressways, reducing the distance of visibility and the traffic safety.

Furthermore, the use of supporting structures for light sources positioned just close to the road or expressway may be dangerous. In effect, if by some misfortune a driver loses control of his vehicle, the impact against one or more supporting structures may lead to very serious or even fatal consequences for the driver and for any potential passengers in the vehicle.

Finally, cases in which the known lighting apparatus do not constitute the optimal solution for lighting and delineating roads and expressways intended for vehicle traffic are not negligible. For example, known supporting structures may prove to be inadequate under extreme climatic conditions and/or in the case of regulatory problems like, for example, in the vicinity of airports.

<CIT> discloses a lighting device for roads comprising a reflector provided with an elliptical shaped light emission window. The reflector further comprises a cavity surrounded by light reflecting walls which extend between a light emission window and a light source, such as a LED type source. Furthermore the window is provided with an optical plate having an outcoupling structure facing towards the light source and realized by a plurality of prisms suitable alternatively for refracting and reflecting the light.

An object of the present invention is to improve the known lighting apparatus for illuminating and delineating outdoor areas, like streets and expressways, intended for vehicle traffic, in particular to realize a road lighting and delineating apparatus that is in conformity with the regulations of the sector, free from the drawbacks described above and at the same time simple and economical to construct.

Another object is to provide a road lighting and delineating apparatus with moderate dimensions, with no supporting pole or bracket and suitable to be installed on essentially vertical surfaces like, for example, a tunnel wall, the surface of a Jersey barrier, or the band of a guardrail.

Yet another object is to realize a road lighting and delineating apparatus that improves visual comfort, and hence traffic safety, and supports the orientation of the driver under any weather conditions and, in particular, in the presence of rain and/or fog.

Another further object is obtain a road lighting and delineating apparatus that does not constitute an obstacle in case of impact by a vehicle, thereby minimizing the consequences for both the driver and the passengers of the vehicle in question.

These and other objects are achieved by a road lighting and delineating apparatus according to one or more of the claims reported below.

The present invention can be better understood and actuated with reference to the attached drawings that represent a non-limiting examplary embodiment, wherein:.

The figures illustrate a road lighting and delineating apparatus <NUM> according to the present invention, which can be installed on a supporting structure <NUM> at a set installation height H from a road surface S, which includes a central body <NUM> with a molded part <NUM> and a frontal wall <NUM> that is substantially transparent. The central body <NUM> has an elongated shape, more specifically the shape of a rectangular parallelepiped with a trapezoidal section, extends in a longitudinal direction A and is provided with a cavity <NUM> with an opening <NUM> on at least one of two sides <NUM> opposed to each another and transversal to said longitudinal direction A. The molded portion <NUM> and the frontal wall <NUM> may be in a single body or the central body <NUM> may form a monolithic element. As an alternative, the molded portion <NUM> and the frontal wall <NUM> can be separated and destined to be coupled to form the central body <NUM> with the cavity <NUM>.

The molded portion <NUM> of the central body <NUM> is equipped with an external seat <NUM>, that in the embodiments illustrated in the figures is opposite the frontal wall <NUM>, and can be engaged with a fixing element <NUM>, comprising for example a bracket intended to be fixed in an adjustable and reversible way to the supporting structure <NUM>, such as the wall of a tunnel, a surface of a Jersey barrier, a band of a guardrail, as in the example illustrated. In this latter case, the bracket <NUM> can be fixed by using a suitable bolt in a slot present on the lower curve of the band of the guardrail <NUM> as illustrated in <FIG>, or by means of a suitable clamp when the bracket has the same shape as the profile of the guardrail <NUM> itself. In the particular case in which the molded portion <NUM> of the central body <NUM> has a shape that is complementary to that of the lowest curve of the guardrail <NUM> profile, more generally speaking, complementary to the shape of the longitudinal cavity <NUM> of the generic supporting structure <NUM>, the central body <NUM> can be housed in this latter in a compact assembly configuration G that is particularly advantageous, in which the volume of the apparatus <NUM> is notably reduced, in particular without protruding from the guardrail itself.

Moreover, the bracket <NUM> can be fixed in an adjustable way to the supporting structure <NUM>, in a way known by a person skilled in the field and not further explained here in detail, in such a way as to be able to suitable orient the apparatus <NUM>, in particular inclining it on a vertical plane of an angle, for example of <NUM>°, according to said installation height H from the road surface S. Consequently, the apparatus <NUM> can be positioned at a set installation height H according to particular road conformations, like curved stretches that require specific attention in controlling the lighting, especially at an installation height H less than <NUM>, for instance equal to <NUM>.

The road lighting and delineating apparatus <NUM> includes at least one blind plug <NUM> with an operational surface <NUM>, designed to be reversibly coupled with the central body <NUM> at said opening <NUM> so as to close, preferably hermetically, the cavity <NUM>. In the embodiments illustrated in <FIG>, the central body <NUM> is provided with a plurality of threaded holes while the blind plug <NUM> is provided with a corresponding plurality of through holes; in this way the coupling can be simply carried out by means of screws that pass through the holes of the blind plug <NUM> and screw into the threaded holes of the central body <NUM>. Alternatively, the blind plug <NUM> can be coupled with the central body <NUM> by interlocking or using magnetic coupling devices.

The operational surface <NUM>, when the blind plug <NUM> is coupled with the central body <NUM>, faces outward from the cavity <NUM> and is intended to house a road delineating system, for example a passive signaling system namely a reflector or retroreflector <NUM> to signal the presence of an obstacle as represented by the supporting structure <NUM> to which the apparatus <NUM> is fixed or the apparatus <NUM> itself. As an alternative, the operational surface <NUM> can house an active road delineating system, as depicted in the second embodiment illustrated in <FIG>, for example, a module or board <NUM> with a plurality of further LEDs <NUM> to delineate exits, curves, dangerous stretches, rotaries, intersections, to support the orientation of a driver in case of fog and warn him promptly of the presence of accidents or roadway construction sites.

With reference to <FIG>, a lighting system <NUM> is housed inside the cavity <NUM> and comprises at least one LED <NUM> adapted to emit light rays L, to which a refractive lens <NUM> and a reflective optical system <NUM> are associated.

The LED <NUM> is mounted on a respective printed circuit <NUM> which is slidably coupled to the supporting means <NUM> positioned inside the cavity <NUM> and connected to the central body <NUM>, for example to a rear wall <NUM> of the molded portion <NUM> opposite the frontal wall <NUM>. As a consequence, the printed circuit <NUM> that is the LED <NUM>, sliding along the supporting means <NUM>, can be stably positioned in a suitable position inside the cavity <NUM>. The supporting means <NUM> are also conveniently constructed in thermally conductive material, for example in aluminum, so as to act also as a heat sink for the printed circuit <NUM>.

The printed circuit <NUM> is equipped with a length of cable, not shown in the figure, that comes out of the apparatus <NUM> through, for example, a gland for the connection to an electric grid system or to power supplying means for the LED <NUM>.

The refractive lens comprises for example a plastic refractive lens <NUM> and is suitably molded according to the LED <NUM> to emit a light flux F directed towards the frontal wall <NUM>. More in detail, the refractive lens <NUM> shows a substantially elliptic section on a primary plane P1 and an asymmetric oblong section on a secondary plane P2 almost perpendicular to the primary plane P1. In a centered optical system, for which an optical axis is defined, as is known to a person expert in the field, two luminous homocentric rays that propagate along respective directions that lay on the primary plane P1 and are symmetric to each other in relation to the optical axis (by definition the optical axis joins the geometric center of the refractive lens <NUM> and the center of the rays), by impinging on the refractive lens <NUM> they propagate along directions that are still symmetrical in relation to the optical axis itself. On the contrary, two luminous homocentric rays that propagate along respective directions that lay on the secondary plane P2 and symmetric to each other in relation to the optical axis, by impinging the refractive lens <NUM> they propagate along whichever directions that do not follow any law of symmetry. The coupling of the LED <NUM> with the respective refractive lens <NUM> thereby determines a suitable photometric solid, in conformity with the regulations of the sector, with a direction of maximum luminous intensity. Orienting the refractive lens so that the secondary plane P2 is almost perpendicular to the road surface S, the direction of maximum luminous intensity can be suitably directed towards the frontal wall <NUM> and graze the road surface S itself.

The reflective optical system <NUM>, responsible for optimizing the overall performance of the apparatus <NUM>, comprises a reflecting body <NUM> and a couple of fins <NUM>. Preferably, the reflecting body <NUM>, on a plane orthogonal to the primary plane P1 and secondary plane P2, has a parabolic cross section that extends along the longitudinal direction A and is secured to the printed circuit <NUM> or to the heat sink. More specifically, the section of the reflective optical system <NUM> is asymmetrical, as it is shorter on one of the two branches of the parabola, advantageously on the branch closest to the road surface S as in the embodiment illustrated in <FIG> and <FIG>.

The reflecting body <NUM> and the fins <NUM> are equipped with respective reflecting surfaces, for example in silver-coated aluminum with high performance (greater or equal to <NUM>%), which constitute an internal surface of said hollow body. In this way, the reflective optical system <NUM> is capable of reflecting part of the light flux F emitted by each refractive lens <NUM> and potentially dispersed, and directing also this part towards the frontal wall <NUM>. Moreover, the fins <NUM> have the further function of reducing the potential dazzle generated by each refractive lens <NUM>. As a consequence, the dispersion of light is limited and the overall performance of the apparatus <NUM> is optimized.

When the road lighting and delineating apparatus <NUM> is positioned at the set installation height H, the light rays L emitted by the LED <NUM> are refracted by the refractive lens <NUM> and reflected by the reflective optical system <NUM> in order to obtain the light flux F that is grazing said road surface S and conform to the regulations of the sector.

In a different embodiment, the apparatus <NUM> according to the present invention comprises a plurality of LEDs <NUM> distributed along a direction parallel to the longitudinal direction A, preferably equidistant from one another. These LEDs <NUM> can be mounted on a printed circuit <NUM> or on respective printed circuits <NUM>, in both cases a respective refractive lens <NUM> and a respective reflective optical system <NUM> being associated to each LED <NUM>.

The apparatus <NUM>, being positioned at a set installation height H less than <NUM>, for example equal to <NUM>, and comprising the lighting system <NUM> described above, is capable of emitting a light flux F that grazes the road surface S and at the same time is capable of containing dazzle within the limits established by current regulations. Hence the use of a road lighting and delineating apparatus <NUM> according to the present invention presents the notable advantage of improving visual comfort, or traffic safety, and supporting the driver's orientation under any weather conditions and, in particular, in the presence of rain and/or fog.

Moreover, in case of vehicle impact, thanks to the fixing system described above, the apparatus <NUM> according to the present invention, is capable of easily detaching from the supporting element, for example from the guardrail band to which it is fixed, and falling to the ground without obstructing the vehicle itself, thereby advantageously minimizing the consequences of a vehicle impact for both the driver and for the passengers.

Claim 1:
Road lighting and delineating apparatus (<NUM>) that can be installed on a supporting structure (<NUM>) at a set installation height (H) from a road surface (S), comprising a central body (<NUM>) with an elongated shape, extending in a longitudinal direction (A) and provided with a cavity (<NUM>), and a lighting system (<NUM>) housed inside said cavity (<NUM>) and comprising:
- at least one LED (<NUM>) mounted on a respective printed circuit (<NUM>) fixed to supporting means (<NUM>) positioned inside the cavity (<NUM>) and connected to said central body (<NUM>), said at least one LED (<NUM>) being adapted to emit light rays (L);
- a refractive lens (<NUM>) and a reflective optical system (<NUM>) that are associated to said at least one LED (<NUM>);
wherein said refractive lens (<NUM>) shows a substantially elliptic section on a primary plane (P1) and an asymmetric oblong section on a secondary plane (P2) almost perpendicular to said primary plane (P1) and to said road surface (S), said light rays (L) emitted from said at least one LED (<NUM>) being refracted by said refractive lens (<NUM>) and reflected by said reflective optical system (<NUM>) in order to obtain a light flux (F) grazing said road surface (S) when said road lighting and delineating apparatus (<NUM>) is positioned at said set installation height (H), characterized in that said reflective optical system (<NUM>) is further able to reduce a dazzle generated by said refractive lens (<NUM>), and in that said printed circuit (<NUM>) is slidingly coupled to said supporting means, said at least one LED (<NUM>) being able to be positioned in suitable positions inside said cavity (<NUM>).