Abstract:
The invention relates to a unidirectional lighting device for illuminating objects and/or for marking lanes, preferably in the airport area. Said device comprises a base having an external housing for placing and fastening the lighting device and optical components which comprise at least one light source, one reflector and one front glass and which produce a light beam along an optical axis. The external housing does not consist of metal and the optical components are disposed in an optical module to be added on to the base, thereby providing a lighting device which is easy to maintain.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application is the US National Stage of International Application No. PCT/EP2004/006623, filed Jun. 18, 2004 and claims the benefit thereof. The International Application claims the benefits of German application No. 10329496.1, filed Jun. 30, 2003, both applications are incorporated by reference herein in their entirety  
       FIELD OF INVENTION  
       [0002]     The invention relates to a unidirectional lighting device for illuminating objects and/or for marking lanes, preferably in the airport area.  
       SUMMARY OF THE INVENTION  
       [0003]     The publication entitled “Approach, Threshold Runway End High Intensity Elevated Light” published by ADB, a Siemens company, Apr. 11, 1997, order number E10001-T95-A61-V1-7600 discloses a unidirectional lighting device for marking the approach and threshold area as well as the takeoff and landing path limits of airports. The lighting device comprises a main body having an external housing which can be erected and fastened on the ground, a post or a mast. The lighting device also comprises optical components, specifically a light source, a reflector and a front glass for producing a parallel light beam.  
         [0004]     A change of the light source in this known lighting device is possible without tools, but can only be carried out at the erection location in the field via a door which is arranged on the rear panel of the external housing. In order to perform workshop maintenance of the optical components, the complete lighting device must be taken down, transported to the workshop and then aligned again after re-erection. The main body of the lighting device consists of a cast aluminum external housing and noble metal parts, and corrosion resistance is therefore difficult to achieve and only partly possible.  
         [0005]     The invention therefore addresses the problem of overcoming the aforementioned disadvantages of the prior art in the case of a lighting device of the type cited at the beginning, in particular of providing a lighting device whose maintenance is simplified.  
         [0006]     According to the invention, the problem is solved by a lighting device of the type in question, said lighting device having the features described herein. As a result of the combination of the partly metallic optical components in a separate optics module which can be installed in the main body of the lighting device, and as a result of the construction of large parts of the external housing of the main body from non-metallic materials, a lower overall weight of the claimed lighting device is achieved, thereby making it easier to replace in the field. As a result of using non-metallic materials for the external housing, in particular a higher corrosion-resistance is achieved for a lighting device in accordance with the invention. Furthermore, the embodiment of the overall lighting device can be smaller, thereby reducing the wind sensitivity and therefore the danger of breakage. Consequently, it is possible to fasten a lighting device according to the invention onto higher masts than in the prior art. The non-metallic and therefore non-conducting construction of the external housing allows the insulated fastening of a drive amplifier of the lighting device, thereby allowing the reliable transmission of triggering signals even over cable lengths up to 250 m. The plastic construction of the external housing provides for greater flexibility in layout and production and for better frictional behavior. Due to the limited heat conductivity and electrical conductivity of non-metallic materials, there are fewer problems taking hold of and handling an external housing of corresponding construction.  
         [0007]     In an advantageous embodiment of the claimed lighting device, the optics module is rotatably linked to the main body via pivoting means. As a result of this, the lighting device can be opened on site, i.e. at the erection location in the field, e.g. by swinging it open, thereby allowing unimpeded access to the built-in parts and in particular the optical components. It is therefore easy to undertake a replacement of the light source in situ, for example.  
         [0008]     In a preferred embodiment of the invention, the optics module is designed to be removable from the main body of the lighting device. The separability of the optics module means that it can be maintained in the workshop without the need to take down the complete lighting device. For example, the pivoting means can be designed in such a way that the optics module can be detached from the main body without using tools.  
         [0009]     In a preferred embodiment of the claimed lighting device, an upper part of the main body, which upper part accommodates the optics module, is designed relative to a lower part of the main body, which lower part carries the upper part, such that it can be tilted about a horizontal axis and rotated about a vertical axis. With the aid of this design, it is possible to perform an orientation of the optical axis of the parallel light beam which is emitted by the optics module. It is particularly advantageous that, when a tilt and rotate position has been set, the upper part does not change in relation to the lower part if the optics module is swung open or removed. Consequently, a time-consuming readjustment of the lighting device is no longer required if a lamp is changed or in the case of maintenance tasks.  
         [0010]     In a preferred configuration of the claimed lighting device, adjusting means are provided for setting and fixing the tilt position of the upper part relative to the lower part of the main body. For this purpose, provision is made for a mechanism having two adjustment screws which engage in a diametrically opposed manner and fix the upper part in a set tilt position. In order to change the tilt position, one of the two adjustment screws is unscrewed by the same amount as the other adjustment screw is tightened, wherein the upper part is tilted about the horizontal axis of rotation. As a result of this adjustment mechanism, it is possible to achieve a very accurate orientation of the angle of the optical axis relative to the vertical. The axial position of an adjustment screw is preferably fixed by a lock nut which engages in the housing. This ensures a locking of the tilt position of the upper part relative to the lower part of the main body of the lighting device according to the invention.  
         [0011]     In a further preferred configuration of the invention, locking means are provided for fixing the rotational position of the upper part relative to the lower part of the main body. As a result, it is likewise possible to fix a set orientation of the optical axis of the light beam in the form of an azimuthal angle relative to a base position.  
         [0012]     The non-metallic external housing of the main body is preferably designed as a plastic part, in particular an injection molded part. In this way, stable non-metallic external housings can be provided at low manufacturing cost for lighting devices in accordance with the invention. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]     Further properties and advantages of the claimed lighting device are derived from the following description of the drawings, in which:  
         [0014]      FIG. 1  schematically illustrates a partly cutaway side view of a lighting device according to the invention;  
         [0015]      FIG. 2  schematically illustrates a lighting device according to the invention, including an optics module in a closed state;  
         [0016]      FIG. 3  schematically illustrates a lighting device according to the invention, including an optics module in a swung open state;  
         [0017]      FIG. 4  schematically illustrates a lighting device according to the invention, including an optics module in a separated state. 
     
    
     DETAILED DESCRIPTION OF INVENTION  
       [0018]     As shown in  FIG. 1 , a lighting device  10  according to the invention has a main body  20  for erecting and fastening the lighting device  10  and an optics module  30  for generating a light beam along an optical axis O. The main body  20  is enveloped by a non-metallic external housing  22  and essentially comprises an upper part  24 , an intermediate part  25  and a lower part  26 . The optics module  30  is laterally attached to the upper part  24  of the main body  20 , which upper part also contains electrical components for controlling and operating the optics module  30 . The upper part  24  is supported on the intermediate part  25  by means of a hinge bolt which is aligned longitudinally along a horizontal axis of rotation H, and is therefore tiltably positioned about the axis of rotation H which extends perpendicularly to the page plane. The intermediate part  25  of the main body  20  is rotatably positioned on the lower part  26  about a vertical axis V. For this purpose, the intermediate part  25  is centered over a bearing journal  27  in the supporting pillar  28  of the lower part  26 . The assembly comprising intermediate part  25 , upper part  24  and optics module  30  is therefore rotatably configured about the vertical axis of rotation V relative to the non-rotatable lower part  26 . A radial necking  29  is formed in the supporting pillar  28  of the lower part  26 , providing a predetermined breaking point if the claimed lighting device  10  is positioned on the ground.  
         [0019]     The optics module  30  has a housing  37  which is adapted to the lateral cross-section of the external housing  22  and in which are arranged a parabolic reflector  34  and a light source  32  in the form of a halogen lamp, said light source being approximately central. The housing  37  is covered on a front side, which is provided for the issue of light, by a front glass  36  that is fastened to the housing  37  by means of a front ring  39  which runs around the circumference of the front glass  36 . Depending on the desired color of the issuing light beam, the front glass  36  is clear or colored red or green.  
         [0020]     The optics module  30  is rotatably linked to the upper part  24  of the main body  20  via pivoting means  40  having the form of a hinge. In this way, the optics module  30  can be swung downwards for changing the light source  32  or for other maintenance tasks, in order to gain access to the rear panel of the housing  37  or to the interior of the housing  22 . Upon completion of the tasks, the optics module  30  is swung upwards again until a seal  38  which surrounds the housing  37  is flush with the external housing  22  of the upper part  24  and the spring keeper  23  in an engaged locking position in the rear panel of the housing  37  secures the optics module  30 . In order to swing open again, the spring force of the keeper  23  must be overcome.  
         [0021]     At the erection location, whether embedded in the ground via the supporting pillar  28  or supported on a post or mast above the ground, the alignment of the optical axis O must be adjusted. The polar and azimuthal angles can be set via the horizontal or vertical axes of rotation H or V. In order to set the polar angle, i.e. the inclination of the optical axis O relative to the vertical, adjusting means  50  are provided in the form of a pair of adjusting screws which are screwed into the intermediate part  25  diagonally from below. The ends of the adjusting screws touch surfaces of the upper part  24  which is arranged rotatably about the horizontal axis of rotation H, wherein only the right-hand adjusting screw of the two adjusting screws is illustrated in  FIG. 1 . In this case, it is only possible to screw in one of the adjustment screws if the other adjustment screw is unscrewed. The adjusting means  50  which are designed in this way allow a very precise adjustment of the tilt position of the upper part  24  relative to the lower part  26  of the main body  20 . Once it has been set, a tilt position can be locked by lock nuts. The setting of the azimuthal angle, i.e. the orientation relative to a celestial direction, is achieved by rotating the assembly which is supported by the lower part  26  about the vertical axis of rotation V. In order to fix a set rotation position, provision is made for locking means  60  in the form of a clamping ring, wherein said locking means grip the external housing of the intermediate part  25  and squeeze it against the supporting pillar  28  when tightened.  
         [0022]     The claimed lighting device  10  device is used e.g. as a signaling entity for air navigation or for other traffic areas, in particular for the approach area, the threshold markings and end markings of landing paths at airports. The non-metallic plastic construction of the external housing  22  of the main body  20  results in a lower weight, thereby facilitating the replacement in the field of a lighting device  10  according to the invention, and greater corrosion resistance, thereby extending the service life of the lighting device  10 . This design also allows smaller dimensions, resulting in reduced wind sensitivity, thereby improving the fragility of a lighting device  10  according to the invention. Furthermore, it is possible to attach the lighting device  10  having smaller overall dimensions to higher fastening masts. The tilt mechanism is situated in the interior of the main body  20  in the case of a lighting device  10  according to the invention, and is therefore attached in a protected manner. The same main body  20  is suitable for optics modules operating as both continuous and flashing lights. The lighting device  10  is protected by seals against ingress of water or dust. Power cables are entirely encased within the main body  20  and are therefore likewise protected.  
         [0023]     An essential advantage of the lighting device  10  according to the invention relates to the increased ease of maintenance and is illustrated subsequently in  FIG. 2  to  FIG. 4 .  FIG. 2  shows a lighting device  10  having a main body  20  to which the optics module  30  is linked via pivoting means  40 , wherein the optics module  30  is swung upwards and fixed to the main body  20  and is therefore in an operating position. In order to change the light source  32 , for example, the optics module  30  is pivoted downwards as per the direction arrow D such that free access exists to the rear panel of the optics module  30 . Following replacement of the light source or following other maintenance tasks which can be performed on site, the optics module  30  is swung upwards via the pivoting means  40  which are designed as a hinge, until the keeper  23  is snapped into its locking position. If a complete replacement of the optics module  30  is required or if more extensive maintenance of the optics module is required in the workshop, the optics module  30  can be entirely detached from the main body  20  as illustrated in  FIG. 4 . This can be achieved by removing the pins which are arranged at retaining plates of the optics module  30  from a voluted supporting plate of the main body  20 , without the need for a disassembly tool.