Abstract:
A method for mounting planar lighting modules on a mounting surface may include: providing on opposite sides of the lighting module fixing indentations opening toward the aforesaid sides, superimposing on said opposite sides of the lighting module stiffening bars having lateral lobes extending into said indentations, and fixing to the mounting surface the stiffening bars superimposed on the opposite sides of the lighting module with the opposite sides of the lighting module sandwiched between the stiffening bars and the mounting surface, whereby the stiffening bars urge the lighting module toward the mounting surface.

Description:
RELATED APPLICATIONS 
       [0001]    The present application claims priority from Italian application No.: TO2012A000841 filed on Sep. 27, 2012. 
       TECHNICAL FIELD 
       [0002]    Various embodiments relate to the mounting of lighting modules. Various embodiments may relate to the mounting of solid state planar lighting modules, for example lighting modules using LED sources as light radiation sources. 
       BACKGROUND 
       [0003]    In the field of solid state lighting (SSL) sources there is a growing tendency to devise modules, such as LED modules, with geometries such that they allow standardized mechanical interconnection, in order to simplify the installation of systems and the interchangeability of parts. For example, the positions of the LEDs and screw holes are currently undergoing standardization by Zhaga. The name “Zhaga” has been given to a collaborative consortium of companies in the lighting technology industry, set up with the aim of facilitating interchangeability of solid state lighting sources, such as LED sources, made by different manufacturers, in order to facilitate, for example, general lighting technology applications. 
         [0004]    In various solutions, the characteristics of thermal coupling between the module and the mounting surface may be affected by the ways in which the lighting module (which may have a substrate formed by a structure similar to that of a printed circuit board (PCB), with a metal base for example) is fixed to the mounting surface (which may be a heat sink or a lighting system, for example). For example, the high thermal power densities generated by arrays (clusters) of LEDs may give rise to mechanical stresses in the substrate of the module; if the module is fixed to the mounting surface at certain isolated points only, substrate deformation phenomena may occur, such that the contact surface is reduced and the performance in terms of heat dissipation is adversely affected. 
         [0005]    In order to overcome these drawbacks, it is possible to make use of rigid casings (which are rather bulky) and/or to add further holes for fixing the substrate, so as to improve the pressure distribution. Leaving aside any other consideration, the latter solution may be impracticable if the lighting system and/or the heat sink are already provided with mounting holes according to standardized solutions, thus making it necessary to create further fixing holes. 
       SUMMARY 
       [0006]    Various embodiments have the object of overcoming the aforementioned drawbacks. 
         [0007]    Various embodiments may offer one or more of the following advantages:
       improvement of the thermal performance;   assured thermal stability over time;   continuity of the lighting characteristics over time;   economy of the solution;   the possibility of avoiding the use of special tools or instruments for mounting the lighting module.       
 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    In the drawings, like reference characters generally refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the disclosed embodiments. 
           [0014]    In the following description, various embodiments described with reference to the following drawings, in which: 
           [0015]      FIG. 1  is a perspective view of some embodiments, 
           [0016]      FIG. 2  is a perspective view of a lighting module which can be used according to some embodiments, 
           [0017]      FIGS. 3 and 4  show, from approximately opposite viewpoints, the implementation of some embodiments, 
           [0018]      FIG. 5  shows a lighting module in plan view, 
           [0019]      FIG. 6  is a sectional view taken along the line VI-VI of  FIG. 5 , reproduced on a magnified scale, 
           [0020]      FIG. 7  shows, on a scale magnified further, the portion of  FIG. 6  indicated by the arrow VII, and 
           [0021]      FIG. 8  shows a component which can be used in some embodiments. 
       
    
    
     DETAILED DESCRIPTION 
       [0022]    The following detailed description refers to the accompanying drawing that show, by way of illustration, specific details and embodiments in which the disclosure may be practiced 
         [0023]    The reference to “an embodiment” in this description is intended to indicate that a particular configuration, structure or characteristic described in relation to the embodiment is included in at least one embodiment. Therefore, phrases such as “in an embodiment”, which may be present in various parts of this description, do not necessarily refer to the same embodiment. Furthermore, specific formations, structures or characteristics may be combined in any suitable way in one or more embodiments. 
         [0024]    The references used herein are provided purely for convenience and therefore do not define the scope of protection or the extent of the embodiments. 
         [0025]    The perspective view of  FIG. 1  shows an example of a mounting arrangement for mounting a plurality of lighting modules  10  (three in the example illustrated here, although any number of modules could be used, from  1  to a generic number n), which are mounted on a mounting surface S. 
         [0026]    In the embodiment illustrated here, which is of the aforementioned type, the surface S comprises the flat top face of a heat sink HS having fins for heat dissipation on the side opposite the surface S. 
         [0027]    The lighting modules  10  described here by way of example may be planar lighting modules, each comprising a substrate  10   a  made in a form similar to a printed circuit board (PCB) on which is arranged a solid state light radiation source composed, for example, of an array or cluster of LEDs  10   b.  The figures also show electric and/or electronic circuitry  10   c  mounted on the substrate  10   b  and intended to provide a power supply to the light radiation sources  10   b  and control of the latter if required. 
         [0028]    Solid state planar lighting modules of this kind are known in the prior art. In various embodiments, the modules  10  may be made (in respect of their shape, dimensions, electrical, mechanical and thermal characteristics, and the like) in accordance with Zhaga standards. 
         [0029]    As mentioned above, various embodiments are suitable for use in mounting any number of planar lighting modules  10  on a mounting surface S. 
         [0030]      FIGS. 2 to 7  relate primarily to the mounting principles that can be used for a single module  10 : in various embodiments, these principles can be extended, using components such as those shown in  FIG. 8  where appropriate, to a plurality of n modules  10 : for example,  FIG. 1  shows an example of the mounting of n=3 modules  10  arranged adjacently on the surface S. 
         [0031]    In various embodiments, the module  10  (and, more specifically, the substrate  10   a  thereof) may be of any shape: the rectangular shape shown in the drawings is only one example of various possible shapes. 
         [0032]    Regardless of its shape, the module  10  may have two opposite sides in which are provided fixing apertures formed by indentations or incisions  100  opening toward the sides of the module  10 . 
         [0033]    In various embodiments, the indentations or incisions  100  may be U-shaped (or V-shaped, or more generally channel-shaped). 
         [0034]    In various embodiments, the module or modules  10  can be fixed onto the mounting surface S by using stiffening bars  102  intended to be superimposed on the opposite sides of the module  10  and having lateral lobes  104  intended to engage the indentations  100 . 
         [0035]    In the lobes  104  there are provided holes  106  through which fixing members such as screws  108  can extend, these members being, for example, screwed into threaded holes provided in the surface S (not shown in the drawings) in order to retain the module or modules  10  on the surface S. 
         [0036]    In various embodiments, the stiffening bars  102  (and the bars  102 ′ described below) may be made from polymers, for example polymers with a low coefficient of thermal expansion (CTE). 
         [0037]      FIG. 4 , which can be considered as an idealized view of a module  10  viewed from below, that is to say from a viewpoint approximately opposed to that of  FIGS. 1 to 3 , shows by way of example some possible characteristics of various embodiments. 
         [0038]    For example, in various embodiments, a generally channel-shaped profile of the indentations or incisions  100  (for example, a U-shaped profile) may allow the stiffening bars  102  to be translated, at least slightly, toward the inside or outside of the module  10  (that is to say, moved transversely relative to the sides where the indentations  100  are provided), with the possibility of adjusting the positions of the holes  106  to make them coincide with threaded holes provided in the surface S for screwing in the screws  108 . 
         [0039]    In various embodiments (as can be seen more clearly, for example, in the cross-sectional views of  FIGS. 6 and 7 ), the stiffening bars  102  may each have a core layer  1020  extending along a general plane of extension (indicated by X 102  in  FIG. 7 ) of the bar  102 . 
         [0040]    In various embodiments, the following elements may project from the core layer  1020  (and therefore from the plane X 102 ):
       the lobes  104 , on a side intended to face toward the mounting surface S, and   a stiffening rib  1022  capable of imparting further rigidity to the bar  102  on the opposite side, that is to say on the side opposite the mounting surface S.       
 
         [0043]    Thus, as shown more clearly in the view of  FIG. 4 , in various embodiments the lobes  104 , intended to extend into the indentations or incisions  100 , are surrounded by flanges  104   a:  consequently, when the stiffening bars  102  are superimposed on the opposite sides of the lighting module  10 , the aforesaid flanges  104   a  can bear against the lighting module  10  around the indentations  100 . 
         [0044]    In various embodiments, the “height” or “thickness” of the lobes  104 , that is to say their dimension measured in a direction orthogonal to the general direction of extension of the bar  102  (and therefore in a direction orthogonal to the plane of the surface S and of the substrate  10   a  of the modules  10 ) may be chosen so as to be slightly smaller than the corresponding dimension of the incisions  100 . 
         [0045]    In other words, in various embodiments, the thickness of the substrate  10   a  of the modules  10  may be chosen in such a way that, when the modules  10  are applied against the surface S and the stiffening/fixing bars  102  are superimposed on them and held in position by fixing members such as the screws  108  (see, in particular,  FIG. 7 ), the end face of the lobes  104  facing the surface S is at least marginally raised or detached from the surface S, thus creating an interval or gap indicated by H in  FIG. 7 . 
         [0046]    In various embodiments, the size of this interval or gap may, for example, be 200 micrometers. 
         [0047]    Thus it is possible to provide a uniform distribution of the pressure with which the lighting module  10  is pressed by the bars  102  against the surface S, which may, for example, be formed by a heat sink. 
         [0048]    In various embodiments, it is also possible to adjust precisely the intensity of this pressure by adjusting the intensity of the action exerted by the fixing members (in the exemplary embodiment considered herein, this would be done by adjusting the degree of tightening of the screws  108 ). 
         [0049]      FIG. 8  shows by way of example the possibility of using stiffening bars  102 ′, which can be considered as “double” bars, for fixing two modules  10  intended to be mounted in adjacent positions (see, for example,  FIG. 1 ). 
         [0050]    In various embodiments, these may be bars having the various characteristics described above with reference to “single” bars  102 , but with the presence of lobes  104  extending, for example in symmetrical positions, on opposite sides of the central body of the bar, thus making it possible to engage indentations or incisions  100  provided, in corresponding positions for example, that is to say facing each other, in modules  10  intended to be mounted in adjacent positions. 
         [0051]    In order to implement the embodiments, the installer may be provided with equipment comprising a set of modules  10  of the type shown herein by way of example, combined with a set of stiffening bars made either in the “single” version indicated by  102  or in the “double” version indicated by  102 ′. 
         [0052]    Two single bars  102  enable a single module  10  to be mounted by fixing (with screws  108  for example) to the mounting surface S with the stiffening bars  102  superimposed on the opposite sides of the lighting module  10 , and therefore with the opposite sides of the lighting module  10  sandwiched between the stiffening bars  102  and the mounting surface S, with the stiffening bars  102  urging the lighting module  10  toward the mounting surface S. 
         [0053]    Two single bars  102  can also be used to mount each module  10  in an array of adjacent modules  10  by the same procedures. 
         [0054]      FIG. 1  shows an example of the possibility of using both versions of the stiffening bars to mount a plurality of adjacent modules  10 , using the “double” bars  102 ′ in the inner positions of the array (one double bar  102 ′ being interposed between and acting on two adjacent modules  10 ) and the “single” bars  102  for the outer positions of the array. 
         [0055]    While the disclosed embodiments has been particularly shown and described with reference to specific embodiments, it should be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the disclosed embodiments as defined by the appended claims. The scope of the disclosed embodiments is thus indicated by the appended claims and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced.