"LED LIGHTING SYSTEM CONSISTING OF INDEPENDENT MODULES"

The present invention relates to a lighting apparatus consisting of individual modules made of extruded aluminum, which are electrically and optically Independent from each other, mechanically coupled to each other without the aid of additional metal bracketing systems.

The object of the present invention belongs to the lighting field of large areas, with preferred application in the field of sport, industry and architecture, The light source recently becoming more widespread, with respect to traditional sources (filament, halogen cycle, fluorescent, discharge sources) is the LED (Light Emitting Diode) I IB (High Brightness) source. In particular, in outdoor applications;, the state-of-the-art high luminance light-emitting diode provides much higher performance, both in terms of energy and qualit (photometric and colorimetric), compared to traditional high-pressure .mercury- vapor sources, meta!-halide vapor sources, high-pressure and low-pressure sodium-vapor sources.

Further advantages of this new technology are: high reliability, long life, high luminous efficiency, reduced heat generation, less weight and bulk, sturdlness, drastic reduction of maintenance costs.

Attention to the environment and continuous search for energy savings make the LED light source currently the best light source in the above mentioned fields. Moreover, being still a very young technology with respect io the other, it has substantial room for growth and development.

In fact, LEDs do not contain substances toxic and harmful to human, animal health and environment, unlike some types of traditional lamps containing mercury and other noxious substances.

Moreover, it should be remembered that from July 01 , 2006 ^' the European Directive 2002/95/EC RoKIS forbids release on the market of electrical and electronic equipment containing (except tor limited quantities) lead, mercury, cadmium,, hexavalent chromium and other substances.

It cannot be excluded that re restrictive and rigorous directives may lead to eliminate any apparatus containing these substances; thus LED will

... i become the light source of excellence.

A LED lighting apparatus consists of various parts: a substrate tMCPCB) on which the L.EDs ar soldered, a passive heal sink comprising a plurality of fins and generally composed of the frame of the lighting apparatus itself and conventionally made of aluminum alloy and subjected to aniicorrosion treatments and/or coating process typically by polyester powder, a possible solution for transferring heat between MCPCB and heat sink, such as for example either a thermal paste positioned between the LED board and the heat sink or a double-sided adhesive adapted to thermal transfer or else a thermal pad, any system to direct the light, i.e. lenses and/or reflectors, a mechanical system for protecting from water and dust generally consisting of a screen of meihacrylate or tempered glass, the system being assembled on the heat sink through screws by interposing therebetween a suitable gasket where appropriate, a driver, such as ah AC/DC converter, for elecirically supplying the lighting apparatus, any remote-control or stand-alone electronics, and power supply devices for supplying any active cooling elements.

LED diodes convert almost all the absorbed power into visible light; nevertheless a quite bulky cooler is required in rder to prevent the P~ junction from heating up and causing a resulting degradation of optical properties. In order to save material and facilitate the application, it is essential to reduce the mass of this component of the power LED apparatus, which can weigh 2- 10kg.

Although LEDs have higher efficiency than other light sources, they may have reliability problems if an one of the parts of the lighting system, including the driver, is not properly protected from overheating.

Since LEDs do not emit infrared radiation, heat must be removed by conduction or convection. If the heat loss is insufficient, the LED may be subject to untimely color change: specifically, the supply voltage starts to decrease, resulting in an increase of the load on the LED driver components and causing their temperature to increase; at even higher temperatures the emission wavelength can be shifted, thereby causing the orange lights to turn to red and the white lights to a blued color, in addition, a thermally stressed LED becomes less efficient and the luminous flux decreases; if the heat is not dissipated, the LED junction can be damaged, thereby leading the entire element to breakage; other consequences can include internal de!amination of the soldering point, damage to the epoxy resin and yellowing of the lenses.

Advances in technology are making the thermal management of LEDs if at all possible even more complex, due to continuous increase of power and current needed to create diodes with greater and greater luminous flux.

Another critical factor to LED detriment is the management of the EDS (Electrical OverStress). which are generated especially on class II appliances made of metal, where low electrical insulation of the LEDs .from the substrate and the inability to discharge overvoltages and overe ^' urrents to ground reference cause the LEDs, and thus the lighting apparatus, to break.

Therefore, between LED boards and heat sink more performing electrically insulating heat transfer means are needed, which can be obtained by- coupling through thermal paste, -which is characterized by low cost but on the other hand has low electrical insulation value and tends to lose its thermal conductivity properties over time. Anyway, in case of failure, this system allows the replacement of the LED board simply by removing the screws intended to fix the board itself on the heat sink.

Another type of coupling is through thermal pads which, while favoring a good thermal dissipation and insulating very well the LED section, are more expensive. Even in this esse, if malfunction occurs, the LED circuit can be replaced simply by removing the screws intended to fix the board on the heat, sink.

Another type of coupling is obtained by thermal double-sided adhesive, which is the best .cost-benefit trade-off for heat transfer and electric insulation; ^' however, while having an improved thermal-conductivity coefficient with respect to other means used for coupling the LED circuit and the heat sink, on the other hand it limits the maintenance/replacement operations to the LED hoards thereby causing the replacement of the entire apparatus where the LED board is assembled.

Currently, in the fields where the following invention is used, power lighting involves the use of lighting apparatuses preferably of the type using LED technology, composed of several lighting bodies usually made- of aluminum die-castings, the bodies being supported together by a metal superstructure which also constitutes the bracket dedicated to the anchorage on a support outside the temp body, which can be, for example, a pole or a wall and/or ceiling, A problem connected to t is solu on is. that it provides 5 modularity of exclusively one-dimensional type; moreover, this solution has a debatable aesthetic result on the apparatus as a whole and high bracketing costs with respect to traditional technology lamps., considering the same luminous ilux generated.

Alternatively, there are lighting bodies whose bearing structure is made

10 by aluminum alloy extrusion process: th s type, although better performin as regards thermal loss with respect to lighting bodies made of die-cast aluminum, tor technical feasibility reasons involves a considerably greater length than the latt er and, therefore, ^' heavier overall ^! \shelf-e.fYeet" of the lamp body applied to the bracketing system intended to bear the lighting body.

i s In addition, in case of apparatuses consisting of iamp-bodies of extruded aluminum, a problem may arise from not having a closure of the supply compartment that is fully integrated into the main body: in this way, the appearance of the apparatus can be not aesthetically acceptable.

In both types, Le, apparatuses made by die-casting or extrusion0 processes, cooling fins for the heat loss contributes to the accumulation of dirt and dust, particularly if they are too close to each other -and/or if there are end closures such as covers, presumably plastic, that prevent liquids and debris accumulated among the t ns themselves from flowing.

^• Additionally, at the state of the art, the electrical compartment intended5 to house the power supply section and, in particular, the driver, is .fully integrated and contained in the main metal body constituting the apparatus; due the lack of thermal separation of the electric compartment, there are problems in managing the operating temperatures of electronic components: specifically, the AC/DC switching driver, a device particularly sensitive to the increase in0 operating temperatures above the allowed limits, may not comply with the electrical parameters described by rating, thereby impairing apparatus performance.

in addition, especially in the case of lamp bodies of extruded alum mum. at the state of the art in existing lighting apparatuses the power supply compartment requires tools and equipment to he accessed, since the opening and closing generally rely on appropriate bolts and screws to be tightened: this can cause problems as .regards the degree of protection of the entire lighting s body..

Purpose of the present ^' invention is therefore to provide a LED lighting apparatus able to overcome the above outlined drawbacks of the known art through the development of new solutions.

Within the scope of the present invention, an object of the invention is to i» obtain a modular apparatus not requiring a metal superstructure to join the various modules, thanks to the coupling in both directions of the basse modules by means of elastic dowels and connecting elements preferably made of stainless steel and suitably inserted both in the cylindrical seats created by placing side by side the individual extruded elements and. in those already i 5 present in the profile,

in the longitudinal direction, the coupling is also guaranteed by profiles or threaded bars preferably made of stainless steel, fixed by means of appropriate bolts and screws.

A further object of the invention achieved by the above described0 modularity is to spare the costs related to the metal superstructures of traditional modular lamps,

It is a further task of the present invention to provide a geometrically well-proportioned apparatus in order to minimize the -stresses on the single supporting bracket, since the modular composition allows the extent along the5 two directions of the so-composed apparatus to be managed at will, thereby allowing the apparatus to be well-proportioned in its entirety as regards the two dimensions, i.e. length and width, and providing a lesser shelf-eifect with respect to the constraint the bracket provides,

A further object of the invention is the possibility to implement a0 lighting apparatus using & heat sink made of extruded aluminium alloy and preferably providing for using thermal double-sided adhesive in coupling the LED board and the heat sink to each other, without affecting the ease of maintenance in case of failure, since each individual module can be replaced in case of failure focalized therein.

it is a further task of the present invention to obtain a lighting apparatus of extruded aluminum alloy provided with inspection door able to be opened without the use of tools and fully integrated into the product design, since in each module there is a mechanism- forming a hinge rally integrated in the apparatus and constraining the door made of extruded luminum alloy to the main body constituting the module, in this way, the aesthetic value of the apparatus is preserved, especially thanks to the possibility to carry out several finishes through anodic oxidation processes. Furthermore, this solution allows the electric compartment of each ndividual module to be easily inspected.

A further object of the invention is to provide ¾ modular lighting body in which the electrical compartments are thermally insulated from the dissipating structure, since this compartment is made by molding technopolymers in this way, the functionality of the -electronic devices therein can be preserved. Furthermore, the electric box being sealed and completely independent from the rest o the apparatus, the power supply section is protected against dust and liquids, thereby ensuring the operation according to the rating.

It is a further task of the present invention to be able to implement a lighting apparatus whose geometry does not contribute to the accumulation of dirt, dust and impurities of any kind that could affect the efficiency of the single module and the entire apparatus, as they do not have any fins designed to dissipate heat, and the geometry of the ending plastic elements of technopolymers, having exclusively aesthetic value, is not obstructing the escape paths.

The present specification is given by way of illustration and example of some embodiments of the present invention and is not intended in any way to limit the object of the claims, the spirit and -object of the present invention being restricted only by the claims reported below.

T herefore, the present invention is now described according to its preferred but .not exclusive embodiments, for illustrative but not limitative purposes, with particular reference to the figures of the accompanying drawings, in which:

^» Figure ? shows an overall ax no metric view of an individual module. * Figure 2 shows an exploded view of t e electric box ,

* Figure 3 shows a cross-section of the individual -module,

* Figure 4a shows an exploded view of the coupling among the different modules.

5 · Figure 4b shows the coupling among four elementary modules.

In accordance with an exemplary embodiment of the present invention, the lighting apparatus comprises a basic module composed of;

- a heat sink made of extruded aluminum alloy, suitably dimensioned so as to obtain a better performance of the apparatus through the thermal

H) management of the heat generated by the LED source;

- a door made of extruded aluminum alloy, fully integrated in the body of the lighting apparatus;

- an electrical box made of teehnopoh mer, containing the power supply driver and the appropriate components, thermally decoupled from the heat sink ϊ 5 for purposes of efficiency linked to the thermal management of the LED apparatus;

- LED MCPCB circuits;

- auxiliary ¹ optics provided with sealing gasket;

- ending plastic dements of technopoiymer. for aesthetic purposes.

8 As evident from the figures, the device according to the Invention consists of basic modules or elementary modules (1 ) having, along at least two sides thereof oriented along two directions not parallel to each other, removable coupling means.

In a preferred embodiment where the elementary modules ( I ) have a5 shape whose envelope is constituted by a parallelepiped with a rectangular base, the individual elementary modules { \ ) can be removably coupled together and locked In the coupling position both side by side and end to end, and this ■combination can take place simultaneously for different modules so as to form a grou of modules arranged in a two-dimensional order.

0 In order to allow lateral coupling, preferably a pair of interlocking lugs for the mutual coupling is provided along two opposite walls of the mantle surface of each module. The lugs forming coupling seats open at the ^' ends and. being arranged in a position such as to mutually interlock ^' by sliding in the direction of their longitudinal length.

Therefore, in particular, two elementary modules 0 ) are coupled to each other ¾»kte by side by fitting the lugs (6. 7} on a side of one of the two modules into the grooves formed by the logs (8, 9) provided on. the facing side of the other module and by sliding the two .modules along the longitudinal direction of said lugs until they are positioned side by side.

Advantageously, each of the lo s forms at the same time both an interlocking groove and a interlocking profile, the lugs being complementary shaped with respect to each other so that the interlocking profile of each, lug engages the interlocking groove of the other lug by longitudinally sliding therein.

Still according to a further improvement, when two adjacent elementary modules ί i ) are in coupled condition, their two lugs have two facing surfaces each having semicylindrical. recess obtained therein and adapted to form half of the delimiting wall of an inserting seat for a divaricating dowel or elastic pin ( 15). thanks to which the lugs are- biased in a direction away from each other and in compression direction to compress the interlocking profile of each lug against a wall of the interlocking seat opposite to the away direction and in which seat said interlocking profile is engaged.

Still according to a farther characteristic resulting from the accompanying figures and to be provided alternatively or in combination, each elementary module (1) has engaging means to mutually engage two modules aligned to each other, placed side by side and parallel to the coupling side wails, i.e. in aligned condition along the longitudinal axis of the elementary module when the latter has rectangular base. In particular in this case, the walls perpendicular to the coupling ones placed side by side are contacted With each other and the removable locking means in the coupling condition are constituted by rods or pins 16 engaged in holes 13 or through eyelets oriented perpendicularly to the contact sides of two end-to-end coupled modules, the rods ^' or pins being provided with, ends coupling the clamping end portions 17 of the two or more end-to-end coupled modules,, ibr example being provided- with threaded end portions on which clamping out screws can he screwed.

Still according to a further improvement, each module is provided With grooves 10, Π or holes to engage centering pins I S protruding perpendicularly to the contact wails of the modules coupled to each other in end-to-end condition,, said centering pins 15 having an extent sueh thai, in the condition of being engaged in the groove 10. I of a module, they protrude in the direction of the module aligned, end-to-end with the former and are coincident with the corresponding groove 10, 1 ί of the fatter, thereby being automatically engaged in this groove when the two modules move towards to each other in the end-to- end .coupled condition.

Another improvement provides that also the divaricating pins or elastic dowels 15 to relatively divaricate the coupling lugs can be engaged only by part of their length in the seats formed by the two lugs of two adjacent modules and may protrude towards a further pair of modules mutually coupled in an adjacent position, thus forming the divaricating dowel or pin 15 to divaricate the coupling lugs of said further pair of modules, said protruding part of each divaricating dowel or pin 15 to divaricate the lugs of the first pair of modules being automatically engaged into the seat formed by the mutually engaged fugs- of the second pair of modules when they are aligned with each other in a direction parallel to said lugs, i.e. in line with the first modules.

From the foregoing and the figures, it. is clear that the invention also comprises a modular lamp system which generally consists of a plurality of identical elementary lamp modules having corresponding removable coupling means to be coupled alternatively or in combination along to two directions of mutual alignment so as to form a two-dimensional distribution of lamp modules.

The invention further- provides a method for manufacturing a modular lamp, which method comprises at least two, preferably a plurality of elementary lamp modules provided with mutual coupling means on two sides of each module, the sides being non-parallel to each other and each, provided with removable coupling and locking means for removably coupling the modules and removably locking them when .coupled to each other, and which method provides t r generating two or more module rows by coupling two or .more .modules at one of the two non-parallel sides of each module and then coupling together said rows at the other of the two non-parallel sides. Still according to a further characteristic of the invention, each elementary module 0 ) has a sealed electrical compartment (2) thermally insulated and housed m an extruded aluminum body (3) provided with an inspection door (4) with integrated hinge.

In particular, at m end of the door 4 there is an ending hinge edge, the hinge being composed of a plurality of arcuate surfaces having circular-sector shaped sections with different bending radii and coaxial with each other and engaging along circular-sector shaped guide surfaces integral with the body (3), the guide surfaces having bending radii such as to position themselves adjacent to one or more of the door circular-sectors and being coaxial thereto and guiding the circular-sector shaped surfaces of the door hinge end b sliding them one on ton of the other, thus allowing the door to angularly swing and keeping the door hinge elements and those guiding the body (3) engaged to each other.

In detail, in Figure I some elements of this invention are shown. Specifically, in the shown configuration, the bask module < l), the sealed electrical box (2) made of technopolymer and housing the power supply section, the main body of extruded aluminum alloy (3), the inspection door of the power supply compartment (4) also made of extruded aluminum alloy, and the protected connector (5) for powering the module can all be seen.

Figure 2 illustrates an exploded view of the electrical compartment (2) made of plastic material and intended to house the power supply section, which consists of a cover (2 , 1 ), a main body (2.2), side barbed membrane grummets

(2.3) useful for the electrical connection between laterally adjacent modules, a bottom (2.4), lower barbed membrane grommets (2,5) to obtain the electrical connection between the box (2) and the LED board (A) of figure 3, a sealing gasket (2.6) for sealing the coupling between cover (2, 1 ) and body (2.2), a sealing gasket (2.7) for sealing the coupling between body (2,2) and bottom

(2.4) and a circular seat (2.8) adapted to house connectors, in case of ending modules, whereas in case of longitudinally adjacent modules, a barbed- membrane cable gland for the electrical connection between ^' the modules.

Figure 3 depicts, in a sectional view, the main body (3) of extruded aluminum alloy, where the side engaging elements (6) and (?) provided with 'upper cylindrical half-cavities to house elastic dowels, and the side engaging elements (8) and (9) provided with 'lower cylindrical half-cavities to insert elastic dowels as well for transversa l!y joining the modules, are indicated. When two modules are iransversally coupled together, the half-cavities (8) and (9) will be coupled, respectively, with the half cavities {6} and (7) of the transversally adjacent module, to f rm cylindrical cavities accommodating the elastic dowel so as to make the modules integral with each other and not able to translate with respect to each other. The main extruded element also has cylindrical cavities C IO) and ( 1 1 } to accommodate additional elastic dowels for longitudinally joining the modules: further cylindrical cavities ( 1 4) for assembling ending plastic elements, through appropriate bolts aid screws, and square-section cavities (Ί2) for the insertion of self- locking nuts adapted to receive any bolts for fixing the supporting brackets: further cylindrical seats ( 13:) adapted to accommodate the threaded bars ( 16) of Figure 4. The view is completed by the door of extruded aluminum alloy (4), integrated in the body O).

Figure 4a shows, an exploded view, a detail of the longitudinal and transverse coupling made by means of elastic dowels < ! 5) and threaded bars ( 16) and integral with the modules by using self-locking nuts ( 17),

Figure 4b depicts the coupling of four elementary modules including the end covers preferably made of technopoiymer.

Thus, it has been shown that the LED lighting system made up of independent modules, described according io the present invention, achieves the predetermined objects and tasks, thereby solving the problems of the prior art.

Several modifications may be made by the person skilled in the art, without departing from the protection scope of the present invention. The protection scope of the claims, therefore, should not be limited by the illustrations or the exemplary preferred embodiments shown in the description, but rather the claims must comprise any feature of patentable novelty inferable from the present invention, including all the features the field technician would consider as equivalents.