Patent Publication Number: US-9835308-B2

Title: Light indicator

Description:
FIELD OF APPLICATION 
     The present finding refers to a light indicator, according to the preamble of the independent claim. 
     The present light indicator is inserted in the industrial field of production of light indicators and illumination apparatuses provided with light sources of LED type, and it is intended to be advantageously employed for indicating to aircraft the presence of high structures, such as smokestacks, towers, skyscrapers, bridges, power line pylons, etc. 
     In particular, the aforesaid light indicator is advantageously employed for signaling the presence of towers or other high buildings, especially those situated in urban areas. 
     STATE OF THE ART 
     It is known to use light indicators mounted for example on towers, on smokestacks or on industrial plant and factory buildings, or on bridges, pylons etc., in order to indicate the presence of aerial obstacles to vehicles such as airplanes and helicopters. 
     In particular, increasingly widespread on the market are light indicators provided with light sources of LED type, since the latter demonstrate greater luminous efficiency than most of the light sources of conventional type (such as incandescent lamps, fluorescent lamps, discharge lamps). 
     More in detail, one example of light indicator of known type comprises a metal tubular body, which is provided with an external surface on which a plurality of LEDs are mounted; each LED is oriented with its light emission axis orthogonal to the external surface of the tubular body. 
     In particular, each LED is formed by a diode which is constituted by semiconductor material and is enclosed in an epoxy or plastic covering, covered with a surface layer of phosphor. 
     In addition, the light indicator comprises a plurality of lenses, each of which fixed on the external surface of the tubular body in front of the LED, intercepting the light emission axis of the latter, and adapted to concentrate the light emitted by such LED into light beams mainly oriented along a horizontal optical axis. 
     More in detail, each lens comprises a substantially hemispherical body of transparent material, provided with an internal cavity in which the corresponding LED is housed, and with a base edge fixed to the external surface of the tubular body around the LED itself. 
     In particular, each lens is fixed to the external surface of the tubular body of the light indicator by means of an adhesive material layer arranged between the base edge of the lens and the external surface of the tubular body. 
     A first drawback of the above-described indicator of known type is due to the fact that the adhesive material, employed for attaching each lens to the tubular body of the indicator, easily comes into contact with the LED arranged inside the lens itself, coming to damage the phosphor layer arranged on the LED covering and therefore limiting the luminous efficiency of the LED itself. 
     A further drawback is due to the fact that the adhesive material can be easily deteriorated, for example due to the heat generated by the LEDs during the operation thereof, with a consequent separation of the lenses from the tubular body of the indicator. 
     Presentation of the Finding 
     In this situation, the main object of the present finding is therefore to overcome the drawbacks shown by the solutions of known type, by providing a light indicator capable of operating in an entirely efficient manner. 
     Further object of the present finding is to provide a light indicator which is structurally simple and inexpensive to make. 
     Further object of the present finding is to provide a light indicator which is capable of operating in an efficient manner, in particular for long time periods. 
     Further object of the present finding is to provide a light indicator which is capable of efficiently removing the heat generated by the LEDs. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The technical characteristics of the invention, according to the aforesaid objects, can be clearly found in the contents of the below-reported claims and the advantages thereof are more evident in the following detailed description, made with reference to the enclosed drawings, which represent several merely exemplifying and non-limiting embodiments of the invention, in which: 
         FIG. 1  shows a perspective view of the light indicator, subject of the present finding, in accordance with a first embodiment; 
         FIG. 2  shows a side view of the light indicator illustrated in  FIG. 1 ; 
         FIGS. 3 and 4  respectively show a front perspective view and a rear perspective view of a detail of the light indicator, subject of the present finding, relative to a row of LEDs with the corresponding light collimation lens associated therewith; 
         FIG. 5  shows a section view of the light indicator illustrated in  FIG. 2  along the line V-V of  FIG. 2  itself, with some parts removed in order to better illustrate others; 
         FIG. 6  shows a cross section view of the light indicator, subject of the present finding, in accordance with a second embodiment, with some parts removed in order to better illustrate others; 
         FIG. 7  shows a perspective view of the light indicator, subject of the present finding, in accordance with a third embodiment; 
         FIG. 8  shows a perspective view of a detail of the light indicator illustrated in  FIG. 7 , relative to a tray in which the LEDs and the lenses are mounted; 
         FIG. 9  shows the tray illustrated in  FIG. 8 , in which the LEDs and the lenses have been removed in order to better illustrate some details of the tray itself; 
         FIG. 10  shows a side view of the tray illustrated in  FIG. 8 , in which some parts have been removed in order to better illustrate the components of the indicator arranged inside the tray itself; 
         FIG. 11  shows a detail of the indicator illustrated in  FIG. 7  relative to a collimation lens for the light emitted by the LEDs. 
     
    
    
     DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT 
     With reference to the set of drawings, reference number  1  indicates overall the light indicator, subject of the present finding. 
     The present light indicator  1  is intended to be advantageously mounted on high buildings (such as skyscrapers, towers, etc.) or on high structures (such as bridges, pylons, smokestacks etc.) in order to indicate the presence of aerial obstacles to vehicles such as airplanes and helicopters. 
     According to the present finding, the light indicator  1  comprises a support body  2  to which at least one LED  3  and at least one lens  4  are fixed, positioned in front of the corresponding LED  3  in order to collimate the light emitted by the latter. 
     In accordance with the embodiments illustrated in the enclosed figures, the support body  2  has substantially tubular form (in particular with polygonal section, e.g. hexagonal section) and is provided with an external surface  5  around which a plurality of the aforesaid LEDs  3  and a plurality of corresponding aforesaid lenses  4  are positioned. 
     In particular, the support body  2 , preferably made of metal material (e.g. aluminum), is longitudinally extended with preferably vertical axis between an upper edge thereof and a lower edge thereof, between which the aforesaid external surface  5  is extended, and is also provided with an internal surface  6 , which defines an internal channel  7  of the support body  2  itself. Preferably, in accordance with the embodiments illustrated in  FIGS. 1 and 7 , the light indicator  1  comprises an upper annular flange  8  and a lower annular flange  9 , which are respectively fixed to the upper edge and to the lower edge of the support body  2 , in particular by means of retention screws  10 , and are each provided with a corresponding central opening aligned with the internal channel  7  of the support body  2  itself. 
     Preferably, the light indicator  1  also comprises a cylindrical sheet  11  made of light-permeable material that is placed around the external surface  5  of the support body  2  and is closed on the top and bottom part respectively by the upper  8  and lower  9  annular flange of the indicator  1  itself. 
     Advantageously, the external surface  5  of the support body  2  of the light indicator  1  comprises multiple flat faces  12  facing each other; on each face, one or more rows of LEDs  3  is preferably positioned. In particular, with reference to the embodiment of  FIG. 3 , the LEDs  3  of each row are arranged substantially aligned with each other along an alignment direction X parallel to the corresponding flat face  12  of the external surface  5  of the support body  2 , and each LED is provided with its light emission axis Y orthogonal to the flat surface itself. 
     In accordance with the embodiment illustrated in  FIGS. 1 and 7 , the light indicator  1  comprises multiple rows of LEDs  3  (e.g. two) arranged on each flat face  12  of the external surface  5  of the support body  2 . Of course, without departing from the protective scope of the present patent, the light indicator  1  can also comprise only one row of LEDs  3  positioned on each flat face  12 , or more than two rows of LEDs  3  positioned on each flat face  12 . 
     Preferably, each lens  4  has substantially elongated form and is positioned in front of the LEDs  3  of a corresponding aforesaid row of LEDs, to intercept the light emission axes Y of such LEDs  3  in order to collimate the light emitted by the latter. 
     According to the present finding, each lens  4  is provided with a rear surface  13  directed towards the corresponding row of LEDs  3  and through which preferably the lens  4  receives in inlet the light emitted by the LEDs  3  themselves. In addition, each lens  4  is provided with a front surface  14  directed in the sense opposite the rear surface  13 , and through which the lens  4  advantageously emits beams of collimated light rays. 
     According to the idea underlying the present finding, the light indicator  1  comprises at least one coupling body  15 , which is extended between two ends  16 ,  17  thereof, of which a rear end  16  is engaged with the support body  2  of the light indicator  1 , and a front end  17  is provided with at least one first bent portion  18  engaged in abutment against the front face  14  of the corresponding lens  4  in order to retain the latter integral with the support body  2  itself. 
     Advantageously, with reference to the embodiment illustrated in  FIGS. 3 and 4 , each lens  4  has elongated form and is extended between two ends  19  thereof according to an extension direction Z substantially parallel to the alignment direction X of the corresponding row of LEDs  3 . 
     The light indicator  1  comprises at least two aforesaid coupling bodies  15 , each arranged at the respective end  19  of the respective lens  4  in order to retain it integral with the support body  2 . 
     Advantageously, each lens  4  is provided, on its front face  14 , with a front groove  20  inside of which the first bent portion  18  of the coupling bodies  15  is engaged. 
     Preferably, with reference to the embodiment illustrated in  FIGS. 3 and 4 , the front groove  20  of each lens  4  is longitudinally extended according to the extension direction Z between the two ends  19  of the lens  4  itself, at which the front groove  20  terminates with two respective lateral openings in order to allow the insertion of the first bent portions  18  of the corresponding coupling bodies  15  in the front groove  20  itself. 
     In particular, the aforesaid front groove  20  is closed on the bottom by a curved and convex portion of the front surface  14  of the lens  4 , and preferably the remaining portions of the front surface  14 , arranged along two longitudinal sides of the front groove  20 , have a flat form. 
     Preferably, the first bent portion  18  of each coupling body  15  is inserted in the front groove  20  from the corresponding end  19  of the lens  4 , being anchored on the portion of the front surface  14  that delimits the bottom of the front groove  20  itself. 
     Advantageously, the rear surface  13  of each lens  4  is provided with a rear groove  21 , which is longitudinally extended according to the extension direction Z of the lens  4  itself, and houses the corresponding row of LEDs  3  at its interior. 
     Preferably, each lens  4  comprises two longitudinal surfaces  22 , placed to connect between the rear surface  13  and the front surface  14 , and in particular with substantially curved form. 
     The two ends  19  of each lens  4  are closed by two respective lateral surfaces  23 , preferably flat, and arranged orthogonal to the extension direction Z of the lens itself. 
     Advantageously, each lens  4  is made of plastic material, in particular PMMA, and is preferably obtained by means of molding. 
     Advantageously, the present light indicator  1  comprises at least one support plate  24  provided with a rear face  25  fixed to the support body  2 , and with a front face  26 , directed in the sense opposite that of the rear face  25  and on which the LEDs  3  and the corresponding lenses  4  are fixed. 
     The rear end  16  of each coupling body  15  is provided with at least one second bent portion  27 , which is engaged in abutment against the rear face  25  of the aforesaid support plate  24 . In this manner, each coupling body  15 , acting on one side on the front surface  14  of the lens  4  (by means of the first bent portion  18 ) and on the other side on the rear face  25  of the support plate  24  (by means of the second bent portion  27 ) retains the corresponding lens  4  integral with the support plate  24 . 
     Advantageously, each coupling body  15  is provided with a central portion  28 , which is placed to connect between the first and the second bent portion  18 ,  27 . Such central portion  28  is provided with an internal side  29  directed towards the lens  4 , from which the bent portions  18 ,  27  are projectingly extended, and with an external side  30  directed in the sense opposite that of the internal side  29 . 
     In accordance with the embodiments illustrated in the enclosed figures, the central portion  28  of each coupling body  15  is directed with its internal side  29  towards the corresponding end  19  of the lens  4  which retains the support plate  24 . 
     The first bent portion  18  of each coupling body  15  is inserted in the front groove  20  of the corresponding lens  4 , extended above the front surface  14  of the latter, starting from the edge defined by the junction of the front surface  14  with the lateral surface  23  facing the coupling body  15  itself. 
     In the present description, the front surface  14  of the lenses  4 , on which the first bent portions  18  of the coupling bodies  15  are engaged, is intended to be any one surface of the lenses  4  opposite the rear surface  13  of the latter, in particular also a surface of the lenses  4  from which the collimated light ray beams do not exit. For example, in accordance with an embodiment not shown in the enclosed figures, each lens is provided with a peripheral flange projecting from the longitudinal surfaces of the lens and provided with a rear surface abutted against the support plate, and with a front surface against which the first bent portions of the coupling bodies are engaged in abutment. 
     Advantageously, each bent portion  18 ,  27  of each coupling body  15  delimits, with the internal side  29  of the central portion  28 , an angle less than or equal to 90°, in order to allow the first and the second bent portion  18  and  27  to be respectively coupled to the lens  4  and to the support plate  24 . 
     Preferably, each coupling body  15  is made of elastically flexible material, and is in particular obtained with a metal plate bent at the ends  16 ,  17 , with preferably elongated form and provided with two longitudinal profiles parallel to each other. 
     Advantageously, each bent portion  18 ,  27  of each coupling body  15  comprises at least two corresponding appendages  18 ′,  18 ″ and  27 ′,  27 ″ that are parallel and spaced from each other, and extended along two longitudinal profiles of the coupling body  15  itself. 
     Preferably, the first and the second bent portion  18 ,  27  of each coupling body  15  are elastically deformed in moving away from each other, respectively from the front surface  14  of the lens  4  and from the rear face  25  of the support plate  24 . 
     In this manner advantageously, the first and the second bent portion  18 ,  27  of the coupling body  15 , when they are engaged with the corresponding lens  4 , are each subjected to an elastic reaction force that tends to push them respectively against the front surface  14  of the lens  4  and the rear face  25  of the support plate  24 , in this manner retaining the lens  4  integral with the support plate  24  itself. 
     In accordance with the embodiments illustrate in the enclosed figures, the light indicator  1  comprises multiple support plates  24  arranged on the corresponding flat faces  12  of the external surface  5  of the support body  2 , each of which bearing, mounted on its front face  26 , the corresponding row of LEDs  3  and the corresponding lens  4  associated with such row of LEDs  3 . 
     Advantageously, each lens  4  is provided with engagement pins  31  projecting from its rear surface  13  and inserted in corresponding holes  32  made on the corresponding support plate  24  in order to position the lens  4  with its extension axis Z parallel to the alignment direction X of the corresponding row of LEDs  3 . 
     In accordance with a first and with a second embodiment of the present finding illustrated in  FIGS. 1-6 , the rear face  25  of each support plate  24  is fixed to the corresponding flat face  12  of the external surface  5  of the support body  2  by means of preferably first fixing screws  33 . 
     Preferably, each support plate  24  is obtained with an electric circuit board  24 ′ adapted to power supply the LEDs  3  mounted thereon. 
     Advantageously, each electric circuit board  24 ′ is connected, preferably by means of one or more electrical connection cables  34 , to an electronic control unit (not shown) for the light indicator  1  adapted to control the operation of the LEDs  3 , preferably in accordance with programmed operating modes. 
     The control unit is advantageously connected to a source of electrical energy (not shown) from which it receives the electric current for supplying power to the LEDs  3  of the light indicator  1 . 
     Advantageously, each electric circuit board  24 ′ comprises a printed circuit, in particular of metal core type, on which metal tracks (not shown) are preferably obtained that are adapted to connect the LEDs  3  mounted on the electric circuit board  24 ′ to the electrical connection cables  34  in order to allow the power supply of the LEDs  3  themselves. 
     In operation, the LEDs  3  during the operation thereof transfer the heat generated thereby to the printed circuit of the corresponding electric circuit board  24 ′, which in turn transfers such heat via conduction to the support body  2 . The latter transmits the heat to the air present in the internal channel  7  of the support body  2  itself. The air thus heated generates an ascending air flow that transports via convection the heat received from the support body  2  to outside the light indicator  1 . 
     Advantageously, each support plate  24  has a preferably polygonal form, in particular rectangular form, and is provided with a peripheral edge  35  having two longitudinal sides  35 ′, parallel to the alignment direction X of the corresponding row of LEDs  3 , and two transverse sides  35 ″ orthogonal to the longitudinal sides  35 ′ and placed to connect the latter. 
     Advantageously, the support body  2  is provided with multiple engagement cavities  36  arranged at the peripheral edge  35  of each support plate  24 , at least partially extended below the rear face  25  of the support plate  24  itself. At such engagement cavities  36 , the second bent portions  27  of the coupling bodies  15  are positioned, such portions abutting against the portions of the rear face  25  of the support plate  24  facing such engagement cavities  36 . 
     Advantageously, in accordance with the first embodiment illustrated in  FIGS. 1, 2 and 5 , the engagement cavities  36  are obtained on the external surface  5  of the support body  2 , and are preferably obtained with longitudinal grooves extended between the upper edge and the lower edge of the support body  2  itself. 
     In particular, each longitudinal groove is extended parallel to the axis of the support body  2  and is positioned at the edges of the latter defined by the junction of the adjacent flat faces  12  of the external surface  5  of the support body  2  itself. 
     Advantageously, each aforesaid longitudinal groove houses at its interior a section of the electrical connection  34  (which connect the circuit boards  24 ′ to the electronic control unit), in a manner such that such cables  34  are not arranged in front of the LEDs  3  and the lenses  4 , blocking the emission of the light. 
     With reference to the first embodiment illustrated in  FIG. 5 , each support plate  24  projects with the transverse side  35 ″ of its peripheral edge  35  above the corresponding engagement cavity  36 , so as to leave a portion of the rear face  25  of the plate  24  itself facing the engagement cavity  36  and therefore not adjacent to the external surface  5  of the support body  2 . The second bent portion  27  of the coupling bodies  15  is engaged in abutment against such portion of the rear face  25  of the support plate  24 ; the coupling bodies  15  preferably abut with the central portions  28  against the transverse side  35 ″ of the peripheral edge  35  of the support plate  24 . 
     Advantageously, in accordance with the second embodiment of the light indicator  1  subject of the present finding, illustrated in  FIG. 6 , each flat face  12  of the external surface  5  of the support body  2  is connected to the flat face  12  adjacent thereto by means of a rounded longitudinal edge  37  of the external surface  5  itself; such rounded longitudinal edge  37  delimits, with the rear face  25  of each support plate  24 , the engagement cavities  36  in which the second bent portions  27  of the coupling bodies  15  are inserted in order to be engaged in abutment against the rear face  25  of the support plate  24  itself. 
     The aforesaid engagement cavities  36  allow advantageously engaging the second bent portions  27  of the coupling bodies  15  with the rear face  25  of the support plates  24 , at the same time allowing the adhesion of most of the rear face  25  of the plates  24  themselves to the corresponding flat faces  12  of the external surface  5  of the support body  2 , in a manner such to facilitate the thermal transmission of the heat (produced by the LEDs  3 ) between the support plates  24  and the support body  2  with a consequent efficient heat removal. 
     The enclosed  FIGS. 7-11  illustrate a third embodiment of the light indicator, subject of the present finding, which is particularly suitable for being employed in environments with high explosion risk, such as petrochemical plants, natural gas extraction plants, refineries, textile products industries, plastic materials industries, pharmaceutical industries, mines. 
     Preferably, in accordance with such third embodiment of the present light indicator  1 , the support body  2  comprises at least one tray  38  inside of which the support plate  24  is positioned, advantageously constituted by the aforesaid electric circuit board  24 ′ for the power supply, bearing the LEDs  3  and the corresponding lens  4  fixed thereto. 
     In particular, with reference to the  FIG. 7 , the support body  2  is provided with multiple trays  38  positioned on the flat faces  12  of the external surface  5  of the support body  2  itself, each tray containing at least one electric circuit board  24 ′ (e.g. two) with the corresponding row of LEDs  3  and the corresponding lens  4 . 
     More in detail, with reference to the embodiment illustrated in  FIGS. 8-10 , each tray  38  comprises a bottom wall  39  provided with an external face  40  fixed to the corresponding flat face  12  of the external surface  5  of the support body  2 , preferably by means of second fixing screws  41 , and with an internal face  42  on which the rear face  25  of the support plates  24  arranged in such tray  38  is fixed. 
     In addition, the light indicator  1  comprises at least one insulating material layer  43  deposited inside each tray  38  to cover the circuit boards  24 ′ on which the LEDs  3  are mounted, in order to insulate the electrical and electronic components of such circuit boards  24 ′ from the inflammable gases of the external atmosphere, in a manner such that such components do not generate sparks that can trigger the inflammable gases present in the atmosphere of the area where the light indicator  1  is installed. 
     Advantageously, with reference to the embodiment illustrated in  FIG. 11 , the rear groove  21  of each lens  4 , in which the corresponding row of LEDs  3  is housed, is closed by longitudinal walls and transverse walls  44  and  45  in order to prevent the insulating material  43 , preferably constituted by silicone gel, from penetrating into the rear groove  21  and being deposited above the LEDs  3 . 
     In particular, each lens  4  is provided on its rear part with two longitudinal walls  44  that are parallel to each other, which are extended parallel to the extension direction Z and transversely delimit between them the corresponding rear groove  21 , and two transverse walls  45  placed to longitudinally close the rear groove  21  itself and preferably arranged orthogonal to the longitudinal walls  44 . 
     The aforesaid longitudinal walls  44  and transverse walls  45  of each lens  4  define a rear edge  46 , which delimits an opening of the corresponding rear groove  21  and adheres on the front face  26  of the electric circuit board  24 ′, closing the aforesaid opening of the rear groove  21 , in order to prevent the insulating material  43  from penetrating into the rear groove  21  itself. 
     Advantageously, in accordance with the aforesaid third embodiment of the present finding, on the internal face  42  of the bottom wall  39  of each tray  38 , one or more aforesaid engagement cavities  36  are obtained and arranged at the peripheral edge  35  of each electric circuit board  24 ′ in order to house the second bent portions  27  of the coupling bodies  15 . 
     The engagement cavities  36  are preferably obtained with notches that are made, preferably during the molding of the tray  38 , on the internal face  42  of the bottom wall  39  of the tray  38  itself. 
     Advantageously, each of such engagement cavities  36  is extended partially outside the peripheral edge  35  of the electric circuit board  24 ′ of the support plate  24  in order to allow the insertion of the second bent portion  27  of the corresponding coupling body  15  in the cavity  36  itself. 
     Such engagement cavities  36  obtained on the tray  38  advantageously allow engaging the bent portions  27  of the coupling bodies  15  with the rear face  25  of the electric circuit board  24 ′, at the same time allowing the adhesion of such rear face  25  to the internal face  42  of the bottom wall  39  of the corresponding tray  38  (preferably made of metal material, preferably aluminum), in a manner such to facilitate the thermal transmission of the heat (produced by the LEDs  3 ) between the electric circuit board  24 ′ and the tray  38  with a consequent efficient heat removal. 
     In operation, in accordance with the third embodiment of the present finding, in order to mount the LEDs  3  and the lenses  4  on the light indicator  1 , the operator preferably fixes each electric circuit board  24 ′ (with the corresponding LEDs  3  mounted thereon) to the internal face  42  of the bottom wall  39  of the corresponding tray  38  by means of the first fixing screws  33 , and subsequently inserts the second bent portions  27  of the coupling bodies  15  in the corresponding engagement cavities  36 . 
     Afterward, the operator bends the central portion  47  of each coupling body  15  towards its external side  30  and arranges the lens  4  on the electric circuit board  24 ′ in front of the corresponding row of LEDs  3 . Then, the operator releases the central portion  28  of the coupling bodies  15  which, by elastic return, bears the corresponding first end bent  18  in abutment against the front surface  14  of the lens  4 , at the same time inserting such first bent portion  18  within the front groove  20  of the lens  4  itself, in order to retain it integral with the electric circuit board  24 ′. 
     In accordance with a further, different embodiment of the present finding (not shown in the enclosed figures), the second end of each coupling body is fixed to the support body of the light indicator by means of at least one corresponding engagement screw screwed into a corresponding threaded hole obtained on the external surface of the support body itself. 
     The finding thus conceived therefore achieves the aforesaid objects. 
     In particular, the coupling bodies according to the present finding allow firmly fixing the lenses to the support body without using any adhesive substance which could deteriorate the LEDs.