Abstract:
Lighting apparatus for airports, in particular flush light, having housing with a housing base and a housing top that includes a recess for receiving a light disc. Light disc facilitates the emission of light from a light source, disposed in the interior of the housing, to the surroundings. A light source carrier on which the light source is mounted is attached to a heat transfer block locked in a recess of the housing top such that edges and/or at least partially flat sides of the heat transfer block are in direct contact with the corresponding sides of the recess.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of pending International Application No. PCT/EP2011/064777 filed on Aug. 29, 2011 and published as WO 2012/028562 A2, which designates the United States and claims priority from German Patent Application No. 10 2010 036 019.8 filed on Aug. 31, 2010. The entire disclosure of each of the above-mentioned patent applications is incorporated herein by reference for all purposes. 
     
    
     TECHNICAL FIELD 
       [0002]    The invention relates to lighting apparatus for airports, especially in-pavement lights, interchangeably referred to as flush lights. 
       BACKGROUND 
       [0003]    A lighting apparatus for airports is described, for example, in DE 20 2009 009 583 U1 which in its capacity as an in-pavement light includes a housing with a housing base and a housing top. A light source is arranged within the housing on a light source carrier. A translucent window is positioned in a recess of the housing top, so that light emitted by the light source can be emitted to the outside through the translucent window within a predetermined angular range. In order to ensure that the heat generated by the light source is removed, to avoid overheating, the housing top or the housing part contains a central heat transfer web or a heat transfer web. A heat transfer plate is additionally arranged between the opposite heat transfer webs of the housing base and the housing top such that the light source carrier is positioned on the heat transfer plate. It is disadvantageous that the mounting of such lighting apparatus is relatively complex and that several different parts are required to enable heat removal. 
         [0004]    There remains a need, therefore, to simplify the structure of a lighting apparatus to ensure a compact housing, effective heat removal, and mounting with reduced effort with few components. 
       SUMMARY OF THE INVENTION 
       [0005]    A lighting apparatus for airports (in particular, a flush light) has housing including a housing base and a housing top. The housing may comprise a recess structured to receive an optically translucent element (such as a window or a prism) through which light from a light source in the interior of the housing can exit the housing to the surroundings. The lighting apparatus may include a light source carrier (for example, a printed circuit board), on which the light source is mounted. The light source carrier may be attached to a heat transfer element, engaging in a recess of the housing top, such that edges and/or at least partially flat sides of the heat transfer element directly contact the corresponding sides of the recess. 
         [0006]    The embodiment of the invention is advantageously structured such that the light source, the light source carrier that carries the light source, and optional additional optical elements (such as, for example, a reflector) are combined into a common modular unit together with a heat transfer element, which modular unit can be fastened in a recess of the housing top by at least one screw clamp, bolt or similar releasable connecting means. screw connection for example. The housing top is not only used as a housing cover but also as a basic mounting part with functional areas thereof adapted to accommodate the modular unit, thereby facilitating repair capabilities and reducing mounting costs. As at least part of a surface of a recess and/or at least partly flat sides of the heat transfer element are arranged directly on the corresponding sides of the recess of the housing top, the heat dissipation is enabled from the light source carrier via the heat transfer element into the housing. 
         [0007]    In accordance with a related embodiment of the invention, a heat transfer element is dimensioned to fit in the housing and the light source carrier is dimensioned to fit on a heat transfer element. The heat transfer element is used as a carrier for the light source and auxiliary optical elements and, on the other hand, for the dissipation of heat into the housing top. In production, concerns related to tolerancing of individual components are reduced because it is substantially merely necessary to connect the housing top with the modular unit on the one hand and the housing top with the housing base on the other hand. 
         [0008]    In accordance with a further embodiment of the invention, the heat transfer element comprises a first surface section structured to accommodate the light source carrier and/or the light source and/or further optical elements, and furthermore an adjacent second surface section adapted for heat dissipation and/or for redirecting a power supply. The second surface section is therefore not only used for heat dissipation, but allows on the other hand the establishment of contact of the light source arranged on an upper flat side with control electronics arranged in the bottom housing part. 
         [0009]    In accordance with another embodiment of the invention, the heat transfer element and/or the housing top and/or the housing base is preferably made of a metallic material, preferably aluminum, to improve heat dissipation. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    In the following, the invention is described by way of examples of embodiments and without limitation of the general inventive concept, with reference to the drawings. 
           [0011]      FIG. 1  is an exploded perspective view of an embodiment of a lighting apparatus as seen from above; 
           [0012]      FIG. 2  is a second detailed exploded perspective view of an embodiment; and 
           [0013]      FIG. 3  is a exploded view of an embodiment of  FIG. 1  as seen from below. 
       
    
    
       [0014]    The lighting apparatus of  FIGS. 1 to 3  includes a housing  1  having a housing base  13  and a housing top  10 . The housing top  10  has a recess  11 ′ accommodating a translucent window-like cover  11 , by means of which light from a light source  6  disposed in the interior of the housing  1  can be emitted to the surrounding environment. The light source  6  is mounted on a light source carrier  5 . The light source carrier  5  is positioned on top of a heat transfer element  4 , the latter engaging in a form fitting manner into a recess  9  in the housing top  10 . The heat transfer element  4  is attached with screws to the housing top  10 . Thereby, enhanced heat dissipation is obtained from light source  5  via the light source carrier  6  and the heat transfer element  4  to the housing top  10 . The housing has a comparatively large surface that is cooled by surrounding air and, therefore, acting as heat sink. The thermal connection of the heat transfer element to the housing base  13  and associated electronic circuitry may be reduced, thereby enhancing the lifetime of the electronic circuitry. 
         [0015]    While the invention can be appropriately modified, examples of embodiments are shown in the drawings and described in detail. It should be understood, however, that the drawings and detailed description are not intended to limit the invention to any particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the present invention as defined by the appended claims. 
       DETAILED DESCRIPTION 
       [0016]      FIGS. 1 to 3  illustrate a preferred embodiment as can preferably be used at airports as in-pavement light in order to mark a roadway or a runway. 
         [0017]    As can be seen in  FIG. 1 ,  FIG. 2  and  FIG. 3 , the lighting apparatus includes a housing  1  in which first and second or more lighting modules  2  and control electronics  3  are arranged. 
         [0018]    The lighting modules  2  includes heat transfer element  4 . As depicted in  FIG. 1  to  FIG. 3 , the heat transfer element may be a massive cuboid-like heat transfer block, to which a light source carrier  5  (provided with a light source  6  and a reflector  7 ) may be fixed by means of a screwed connection  8 . The light source carrier  5  is arranged as a printed circuit board on which the LED light sources  6  (in the present case two LED light sources  6 , LED chips) are arranged. 
         [0019]    The LED light sources  6  are respectively associated with reflector areas  7 ′, so that light emitted by the light sources  6  is deflected in the direction of a translucent window like cover  11  fitted into a recess  11 ′ of a housing top  10 , and can be emitted to the surrounding environment. The housing top  10  is detachably connected by means of a screwed connection  12  with a housing base  13  of the housing  1 , wherein a circumferential edge  14  of the housing top  10  is directly (and, optionally, exclusively) connected via a flat seal  15  with a circumferential edge  16  of the housing base  13 . 
         [0020]    The translucent cover  11  is fitted via a seal  17  in the recess  11 ′ of the housing top  10 . Since the lighting module  2  is detachably connected with the housing top  10  via a screwed connection  18 , a solid fit of the translucent coyer  11  in the recess  11 ′ is ensured. 
         [0021]    In accordance with an alternative embodiment of the invention (not shown), the lighting module  2  and/or the heat transfer element  4  can be detachably connected to the housing top by means of a bayonet catch or by latching on the housing top  10 . 
         [0022]    The heat transfer element  4  includes an oblique surface  20  on an upper flat side  19  of the heat transfer element, to which the plate-like light source carrier  5  is fixed by means of the screwed connection  8 . An opposite bottom flat side  21  of the heat transfer element  4  is preferably arranged in a flush manner with a bottom side of the housing top  10 . Circumferential boundary surfaces  22  of the heat transfer element  4  rest directly on corresponding boundary sides  23  of a recess  9  of the housing top  10 . Preferably, the heat transfer element  4  is arranged in an interlocking fashion in the recess  9  of the housing top  10 . 
         [0023]    In accordance with an embodiment of the invention, the heat transfer element  4  can therefore be arranged in an interlocking and/or friction-locked manner in the recess  9  of the housing top  10 . 
         [0024]    The light source carrier  5  and/or the reflector  7  is arranged in a first surface section  24  on the flat side  19  of the heat transfer element  4 . In a second surface section  25  of the heat transfer element  4 , heat dissipation areas  26  which rest directly on corresponding base areas  27  of the recess  9  are provided to improve heat dissipation. The heat transfer areas form a part of the upper flat side  19 . On the other hand, the second surface section  25  enables a deflection or redirection of a connection line  28 , e.g. for powering the light sources and/or data exchange between a control circuitry and electronics on the light source carrier  5 . The connection line  28  may be a ribbon cable. One end of the connection line  28  is connected with a connection of the light source carrier  5 . An opposite end of the connection line  28  is connected with a connection of the control electronics  3  which is positioned in a cavity  29  of the housing base  13 . 
         [0025]    The heat transfer element  4  has a wall thickness d that is larger than a wall thickness of the light source carrier  5 . Preferably, the wall thickness d of the heat transfer element  4  is more than twice as large as the wall thickness of the light source carrier  5 . 
         [0026]    The cuboid heat transfer element  4  has flat sides  19 ,  21  that are more than twice as large as flat sides of the light source carrier  5 . 
         [0027]    The heat transfer element  4  and the housing top  10  and the housing base  13  are preferably made of a heat-conducting metal material, especially aluminium. The housing base  13  is detachably connected with the housing top  10  via a screw connection  12 . Openings  31  for the connection of electric cables  32  are provided in a base area of the housing base  13 , so that the control electronics  3  can be supplied with electrical power. 
         [0028]    For the purpose of mounting the lighting apparatus, the lighting module  2  is mounted, in a first step, on the heat transfer element  4  by means of the screwed connection  8  of the light source carrier  5  and under connection of the connection line  28  to the light source carrier  5 . Subsequently, the lighting module  2  is locked in the recess  9  by means of the screwed connection  18 , wherein the translucent cover  11  has previously been positioned in the recess  11 ′. Thereafter, the housing base  13  that is provided with the control electronics  3  can be connected by means of the screwed connection  12  with the housing top  10 , wherein the lighting module  2  and the control electronics  3  are arranged in the interior of the housing  1 . 
         [0029]    It will be appreciated by those skilled in the art that this invention provides lighting apparatus particularly suited for airport lighting. Further modifications and alternative embodiments of various aspects of the invention will be apparent to those skilled in the art in view of this description. Accordingly, this description is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the general manner of carrying out the invention. It is to be understood that the forms of the invention shown and described herein are to be taken as the presently preferred embodiments. Elements and materials may be substituted for those illustrated and described herein, parts and processes may be reversed, and certain features of the invention may be utilized independently, all as would be apparent to one skilled in the art after having the benefit of this description of the invention. Changes may be made in the elements described herein without departing from the spirit and scope of the invention as described in the following claims. 
       LIST OF REFERENCE NUMERALS 
       [0000]    
       
           1  housing 
           2  lighting modules 
           3  control electronics 
           4  heat transfer element 
           5  light source carrier 
           6  light source 
           7 ,  7 ′ reflector, reflector areas 
           8  screw connection 
           9  recess 
           10  housing top 
           11 ,  11 ′ translucent cover (window)/recess 
           12  screw connection 
           13  bottom housing part 
           14  edge 
           15  flat seal 
           16  edge 
           17  seal 
           18  screw connection 
           19  upper flat side 
           20  oblique surfaces 
           21  bottom flat side 
           22  boundary side 
           23  boundary side 
           24  first surface section 
           25  second surface section 
           26  heat transfer areas 
           27  base areas 
           28  connection line (power and/or data) 
           29  cavity 
           31  opening 
           32  electric cable 
         d wall thickness