Abstract:
A lighting device for outdoor use comprising a lighting body and a socket body, where the lighting body comprises a lighting unit, a first electrical connection and a first locking member. The socket body comprises a second electrical connection and a second locking member, wherein the first and second electrical connections are arranged to connect to each other in a closed position in order supply the lighting unit with power. The first locking member and the second locking member are arranged for locking and unlocking the lighting body to the socket body in said closed position. The lighting body comprises a first fastening device and the socket body comprises a second fastening device, wherein the fastening devices are arranged to. The lighting body comprises a first guiding means and the socket body comprises a second guiding means, which are arranged to interact.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a U.S. National Phase patent application of PCT/SE2013/050085, filed on Jan. 31, 2013, which claims priority to Swedish Patent Application No. 1250071-6, filed on Feb. 1, 2012, and Swedish Patent Application No. 1251100-2, filed on Oct. 1, 2012, the entire contents of which are incorporated herein by reference. 
     FIELD OF THE INVENTION 
     The present invention relates to a lighting device for outdoor use comprising a lighting body and a socket body, where the lighting body is adapted to be easily arranged on the socket body using guiding means and fastening devices for easy mounting and dismounting. 
     BACKGROUND OF THE INVENTION 
     Replacement of light bulbs in street light fittings are traditionally handled by a person that is lifted to the street light fitting in a man lift or similar and by hand opens up the light fitting and next replaces the light bulb. This is problematic in several aspects. 
     The most obvious aspect is the risk that the person performing this operation is exposed to as the work is carried out at significant height. Another problem with having personnel lifted at height in the vicinity of lampposts is, in those cases these lampposts are found in the vicinity of overhead lines, that overhead lines generally are uninsulated and thus are highly dangerous to come into contact with. This represents an additional significant risk. 
     In addition to the work being carried out at height, the work with lampposts involves further problems since the lampposts are not completely fixed. The strain that lampposts are exposed to from weather and wind in addition to the facts that they are very tall and that the street light fitting often has a considerable weight makes them swaying by nature. This results in that the lamppost itself in many cases may not provide support at e.g. replacement of street light fittings. 
     In addition, the operation of replacing the lighting unit/bulb or the entire street light fitting requires a relatively long period of time since the person that performs the work has to be lowered down between each operation, when the man lift or similar is moved between the lampposts. In most cases, the man lift or similar has to be driven on the roadway, or the like, that the street lighting is intended to illuminate. This unit is usually very slow and requires much space on the roadway, which is problematic since the man lift or similar, and also the person that performs the work and has to move between the man lift and the driver&#39;s seat, risk to get hit. For the personnel, it is especially dangerous if the stationary man lift or similar gets hit in the raised position. Additionally, the traffic and the traffic flow may be adversely affected by the presence of the man lift, which may increase the risk of other accidents. 
     In order to minimize the impact on traffic, the work is advantageously performed during evening and night time, which is not always preferable from the view of the performing personnel. 
     All this implies that the time required for replacing a lighting unit/bulb, or the entire street light fitting, should be kept to an absolute minimum. 
     A first step in minimizing the time required for replacing lighting unit/bulb is to replace a larger unit than just the lighting unit/bulb. A larger unit may often be made more robust than just a lighting unit/bulb and may be specifically adapted to be easy to mount and dismount. 
     SUMMARY OF THE INVENTION 
     The object of the invention is to provide an alternative procedure for assembly of lighting devices outdoors, especially street lighting situated at height which poses great demands on the light fitting&#39;s ability to resist moisture, wind and other external stress. The inventive lighting device is designed to withstand this. Lighting devices for outdoor use pose special demands e.g. with regard to the possibility of easy and time efficient assembly and disassembly. 
     The solution to the problem according to the invention is described in the characterizing part of claim. Further claims are directed to advantageous embodiments and further developments of the invention. 
     The above mentioned problem is solved by using a lighting device for outdoor use comprising a lighting body and a socket body. The lighting body comprises a lighting unit, a first electrical connection and a first locking member. The socket body comprises a second electrical connection and a second locking member, wherein the first and second electrical connections are arranged to connect to each other in a closed position in order to supply the lighting unit with power and further wherein the first locking member and the second locking member are arranged for locking and unlocking the lighting body to the socket body in said closed position. The closed position involves the lighting body being locked to the socket body by the first and the second locking members. In the closed position, the lighting body is substantially parallel to the socket body. Further, the inventive lighting device is characterized in that the lighting body comprises a first fastening device and the socket body comprises a second fastening device. These first and second fastening devices are arranged to interact at least at connection of the lighting body to the socket body by in a first open position allowing a rotational relative motion between the lighting body and the socket body both in azimuth direction and elevation direction, and by simultaneously locking a relative motion between the lighting body and the socket body in longitudinal direction. Further, the lighting body comprises a first guiding means and the socket body comprises a second guiding means, which first and second guiding means are arranged to interact at least at connection of the lighting body to the socket body by in a second open position allowing a relative motion between the lighting body and the socket body only in elevation direction. This construction allows for the lighting body to be easily arranged on the socket body. In this case, azimuth direction refers to a motion around a point in the horizontal plane and elevation direction refers to a motion around a point in the vertical plane. 
     According to one example of the invention concerning the lighting device, the first open position relates to a first minimum distance between a longitudinal centre line of the lighting body and a longitudinal centre line of the socket body, taken at the longest distance from the first and second fastening devices. The second open position relates to a second minimum distance between the longitudinal centre line of the light fitting and the longitudinal centre line of the socket body, taken at the longest distance from the first and second fastening devices. The second minimum distance is smaller than the first minimum distance. This may also be expressed as the lighting body being in its first open position in relation to the socket body when only the first fastening device of the lighting body is interacting with the second fastening device of the socket body. The lighting body is in its second open position when the lighting body has approached the socket body and the first guiding means of the lighting body interacts with the second guiding means of the socket body. The lighting body is in the closed position in relation to the socket body when the lighting body is arranged on the socket body. 
     This may be clarified by specifying the three distinct positions that the lighting body may adopt in relation to the socket body as:
         a first open position which involves that at least the first fastening device of the lighting body and the second fastening device of the socket body interact so that the lighting body is guided relative to the socket body, both through a rotational motion in horizontal direction and through a rotational motion in vertical direction;   a second open position which involves that at least the first guiding means of the lighting body and the second guiding means of the socket body interact so that the lighting body is guided relative to the socket body through a rotational motion in horizontal direction, wherein the distance between the lighting body and the socket body is smaller in the second open position than in the first open position;   a closed position where the lighting body is substantially parallel to the socket body and the lighting body is locked to the socket body by means of the first and second locking members and further, the first electrical connection of the lighting body is connected to the second electrical connection of the socket body in order to supply the lighting body with power.       

     Consequently, the first open position constitutes a first phase in the assembly of the lighting body onto the socket body. The second open position arises in a later stage of the assembly of the lighting body onto the socket body, when the distance between the lighting body and the socket body is smaller than in the first open position. In the closed position, the lighting body is arranged on the socket body. 
     In an advantageous development of the invention, the first guiding means is comprised in the first fastening device and the second guiding means is comprised in the second fastening device. 
     In another advantageous development of the invention, the first and second guiding means are provided at a distance from the first and second fastening devices. 
     In an advantageous development of the invention, the first and second locking members are provided at a distance from the first and second fastening devices. 
     In further an advantageous development of the present invention, the lighting body comprises the first fastening device, where the first fastening device comprises a rear wall with an internally located contact surface. The rear wall advantageously comprises a hook portion in the lower part of the rear wall, which either consists of the rear wall being bent or one or more separate parts being arranged at the lower part of the rear wall. The rear wall may also be without a hook portion. 
     The lighting device further comprises a second fastening device provided on the socket body, comprising a from the socket body projecting socket part. The projecting socket part has a shape that fits well with the rear wall of the lighting body. Further, the projecting socket part may either be substantially as wide as the lighting body, as the socket body or narrower than any of these. The projecting socket part may also be composed of a plurality of projecting parts instead of one continuous part. The projecting socket part and the internally located contact surface may interact in order to form a point of contact around which the lighting body may execute a rotational motion both in azimuth direction and elevation direction relative to the socket body when the lighting body moves from the first open position to the second open position, and may execute a rotational motion in elevation direction relative to the socket body when the lighting body moves from the second open position to the closed position. 
     In an advantageous example of the invention, the internally located contact area of the first fastening device has a, as viewed from the lighting body, rearwardly tapering shape, and the projecting socket part of the second fastening device has a, as viewed from the socket body, rearwardly pointed shape. The rearwardly tapering shape of the first fastening device and the rearwardly pointed shape of the second fastening device are adapted to interact with each other to fit in horizontal direction and vertical direction as the lighting body is arranged against the socket body in its first open position. 
     In another advantageous example of the invention, two points on the lighting body interact with two points on the socket body in order to form an axis around which a relative motion in elevation direction may take place. 
     In one example of the invention, the lighting body comprises two lighting body points, located on either side of, and equidistant from the plane of symmetry of the lighting body. These two lighting body points are located on the inner surfaces that are formed at the inside of an upwardly tapering housing, in proximity to the first fastening device. The two lighting body points interact with two socket body points, located on either side of, and equidistant from the plane of symmetry of the socket body, located along the outer surfaces of the socket body, wherein these two lighting body points and two socket body points may interact and form a pivot axis about which a relative motion between the lighting body and the socket body only in elevation direction may take place when the lighting body is in its second open position. 
     In an advantageous example of the invention, the lighting body comprises the first locking member and the socket body comprises the second locking member, wherein the first locking member and/or the second locking member consist of resilient means that allow closing and opening when subjected to a predetermined load. 
     In an advantageous example of the invention, these resilient means are constituted by at least one metallic leaf spring. The resilient means can also be constituted by more than one leaf spring, and can be arranged substantially centrally in the width direction, the width direction being a direction perpendicular to the longitudinal direction of the lighting body also to the centre line of the lighting body, of the lighting body, shifted towards any of the edges of the illumination body, substantially parallel to the centre line of the lighting body, or symmetrically about the centre line of the lighting body. 
     In a possible example of the invention, the resilient means may at the arrangement of the lighting body against the socket body, when the lighting body is moved from its second open position to its closed position, bear against the socket body, whereby the resilient means exerts a force on the front abutment surface of the socket body which further locks the lighting body to the socket body in longitudinal direction. 
     In an advantageous example of the invention, the first guiding means is constituted by a housing having upwardly tapering upper walls, and substantially parallel lower walls, wherein the second guiding means is constituted by the to the longitudinal direction of the socket body substantially parallel outer surfaces of the socket body, which outer surfaces have upwardly tapering upper outer walls and substantially parallel lower outer walls, wherein the first guiding means is adapted to interact with the second guiding means. The interacting shapes of the first guiding means and the second guiding means, where both the first guiding means and the second guiding means have an upper part with concordantly tapering surfaces and a lower part with substantially parallel surfaces, causes the lighting body to be guided towards the socket body so that the lighting body and the socket body are substantially parallel in width direction when the lighting body moves in elevation direction from the second open position to the closed position and possibly even when the lighting body moves in elevation direction from the first open position to the second open position. The lower, substantially parallel walls of the first guiding means may also be slightly upwardly tapering and the substantially parallel lower outer walls of the second guiding means may also be slightly upwardly tapering. 
     In another advantageous example, the housing of the lighting body is made of aluminium or plastic, but the housing may also be made of other materials that can withstand the external stress that the lighting device is exposed to. Being able to position the lighting body correctly in relation to the socket body is in many cases a prerequisite for being able to arrange the lighting body against the socket body since it allows that the socket body is not optimally aligned to the lighting body in the initial phase of the arrangement. This is not least important in case the socket in turn is mounted on for example on a post or another not completely fixed structure and/or the lighting body is arranged on the socket body with the help of a robot or the like. 
     In another advantageous example, the first electrical connection comprises an earth terminal, and the second electrical connection comprises a terminal adapted to interact with the earth terminal. 
     In further an advantageous example of the invention, the earth terminal is provided closer to the projecting socket part of the socket body than other terminals, so that the earth terminal is connected first of all the contacts at the electrical connection of the lighting body to the socket body, and wherein the second electrical connection comprises a terminal adapted to interact with the earth terminal which is provided closer to the projecting socket part of the socket body than other terminals. 
     In another advantageous example of the invention, the lighting body comprises a gasket arranged around a connection recess. The gasket defines the distance between the lighting body and the socket body in the closed position of the lighting device together with the connection of the first electrical connection to the second electrical connection. 
     In an advantageous example of the invention, the lighting device comprises a gripping device, which is arranged on the lighting body, where the gripping device is intended for a robot to grip at mounting and dismounting of the lighting body to/from the socket body. The gripping device is arranged to allow a rotational relative motion between the lighting body and the robot both in azimuth direction and elevation direction. 
     At mounting and dismounting, also termed arrangement, a robot may by means of the gripping device, holding the lighting body in the gripping device, with the lighting body initially hanging substantially vertically, thanks to that the design of the gripping device allows the lighting body to move in azimuth direction and elevation direction in relation to the robot, arrange the lighting body in the first open position by a movement of the robot that brings the lighting body to the socket body in the intended manner. The fitting of the lighting body to the socket body may be enabled by the interaction of the first and the second fastening devices and/or the interaction of the first and the second guiding means. 
     Further, the robot may at mounting of the lighting body to the socket body, thanks to that the design of the gripping device allows the lighting body to move in azimuth direction and elevation direction in relation to the robot, move the lighting body from its first open position to its second open position by a movement of the robot, holding the lighting body. The fitting of the lighting body to the socket body is enabled at least by the interaction of the first and the second fastening devices. 
     Finally, during mounting the robot may, thanks to that the design of the gripping device allows the lighting body to move in elevation direction in relation to the robot, move the lighting body from its second open position to its closed position by a movement of the robot. The fitting of the lighting body to the socket body is enabled at least by the interaction of the first and the second guiding means. 
     Further, the lighting device may be arranged on a holder, and thus constitute a street lighting system comprising a lighting device and a holder, wherein the socket body is arranged against the holder. In an advantageous example of the invention, the holder is further arranged on a post. The holder may also be arranged on something else than a post. The inventive lighting device can also be used with other types of holders. 
     The socket body may further comprise means that enable adjustment of the inclination of the socket body in relation to the holder that the socket body is mounted on, which results in the possibility of adjusting the inclination of the lighting device relative to the ground plane. 
     The problems that are described above in the technical field are solved by using a robot especially adapted to arrange, i.e. assemble and disassemble, lighting devices arranged at height. This robot is preferably arranged on a man lift, crane or the like or on a wagon-bridge, a separate carriage or the like on a vehicle adapted for the purpose. The robot preferably comprises:
         an arm, arranged on any of the aforementioned platforms, adapted to be able to move the robot vertically, laterally, rotationally, tilting the robot etc., so that a robot head can be placed directly adjacent to the lighting device or the like to be worked,   said robot head, arranged on the arm, comprising at least one robot arm for disassembly and/or assembly of lighting devices or the like, wherein the robot head preferably is able to rotate in order to make possible that disassembly of existing lighting device and assembly of a new lighting device can be performed in one stage,   said, at least one, robot arm, arranged on the robot head, comprising at least one gripping device, and together with the gripping device further adapted for gripping and disassembling existing lighting devices and/or assembling new lighting devices, and   said, at least one gripping device, arranged on the robot arm, adapted to be able to grip the lighting device that is to be disassembled and/or the lighting device that is to be assembled. Further, the robot preferably is remote-controlled and provided with means adapted to fix the robot to the holder from which an existing lighting device is to be disassembled/to which a new lighting device is to be assembled.       

     In case a robot is used to assemble and disassemble lighting devices, it is a prerequisite that the disassembly and assembly stages do not comprise many different and complicated stages since this requires far too complex robots. In addition, the components that are affected by the process ought to be relatively robust. 
     With the simplicity in regard of arrangement, i.e. assembly, disassembly etc., and the robustness that the inventive lighting device possesses, the inventive lighting device is optimally adapted for being combined with the concept of assembling and disassembling lighting devices by using a robot. 
     Lighting devices that are simple and quickly disassembled and assembled are advantageous also in the case when the assembly/disassembly is performed by a person, but an additional advantage of using some kind of robot adapted for the purpose for performing the work, contrary to a person performing the work, is that there is not the same need to earth the lighting device if a robot performs the work. 
     The above mentioned examples can be combined freely, but can also occur separately. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be described in greater detail in the following, with reference to the figures, wherein 
         FIG. 1  shows a schematic example of a lighting device according to the invention, 
         FIG. 2  shows another schematic example of a lighting device according to the invention, 
         FIG. 3  shows a schematic example of a lighting body viewed obliquely from below according to the invention, 
         FIG. 4  shows a schematic example of the invention in cross-section from behind, 
         FIG. 5  shows a schematic example of an inventive lighting body from below, 
         FIGS. 6, 7, 8, 9, and 10  show schematically a sequence of how an example of a lighting body is arranged on a socket body according to the invention, 
         FIG. 11  shows a schematic example of a socket body according to the invention, and 
         FIG. 12  shows another schematic example of a socket body according to the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The following described examples of the invention are only to be regarded as examples and should in no way be limiting to the scope of the claims. Thus, the examples are not to be interpreted restrictively. Components may be part of the invention even if not exposed in the following figures. 
       FIG. 1  shows an example of an inventive lighting device  101 , comprising a lighting body  201  and a socket body  301  in cross-section.  FIG. 1  shows the lighting body when in a second open position  401 , where the first guiding means of the lighting body  201  and a second guiding means of the socket body  301  interact in order to guide the lighting body  201  towards the socket body  301  in elevation direction. Furthermore,  FIG. 1  shows how the projecting socket part  501  of the socket body  301  interacts with the internally located contact surface  601  of the lighting body  201  and forms a point of contact around which the lighting body  201  can move in elevation direction relative to the socket body  301 . 
     In  FIG. 1 , arrows are showing the movement in elevation direction with alfa α and movement in longitudinal direction with LL. 
       FIG. 2  shows another example of an inventive lighting device  102 , comprising a lighting body  202  and a socket body  302  in cross-section.  FIG. 2  shows the lighting body  202  when in a second open position  402 , where the first guiding means of the lighting body  202  and the second guiding means of the socket body  302  interact in order to guide the lighting body  202  towards the socket body  302  in elevation direction. Furthermore,  FIG. 2  shows how the projecting socket part  502  of the socket body  302  according to the example interacts with the internally located contact surface  602  of the lighting body  202  and forms a point of contact around which the lighting body  202  can move in elevation direction relative to the socket body  302 . Furthermore, the example of  FIG. 2  shows how the first electrical connection  702  of the lighting body  202  is about to be connected to a second electrical connection  802  arranged on the socket body  302 . In  FIG. 2  can also be seen a first locking member  902  arranged on the lighting body  202 , in this case in the form of a leaf spring, and a second locking member  1002  arranged on the socket body  302 , in this example in the form of a in the socket body arranged recess adapted to interact with the first locking member  902  in order to lock the lighting body  202  to the socket body  302  when the lighting body  202  is in its closed position. This is just an example of how the interacting first and second locking members  902 ;  1002  may be designed, and an example of how the interacting first and second electrical connections  702 ;  802  can be designed. Furthermore,  FIG. 2  shows how the socket body  302  is arranged on an example of a holder  1102 . 
       FIG. 3  shows an example of an inventive lighting body  203  viewed obliquely from below. In the example of  FIG. 3 , a first guiding means  1203  with upwardly tapering upper walls  1303  and lower substantially parallel walls  1403  is shown. In the example, the rear wall  1603  of the first fastening device  1503  is further shown. In the example according to  FIG. 3 , a hook portion  1703  is arranged on the lower part of the rear wall  1603 . Furthermore, the hook portion  1703  is placed centrally according to  FIG. 3 , but the hook portion  1703  may also be in the form of one or several portions, placed centrally or symmetrically on the rear wall  1603 , or in the form of a continuous flange. Furthermore, the internally located contact surface  603  is shown above the hook portion  1703 . 
       FIG. 4 . shows a cross-section of an example of the lighting device  104  where the lighting body  204  is arranged on the socket body  304 . Furthermore,  FIG. 4  shows how the first guiding means  1204  of the lighting body  204  comprises upwardly tapering upper walls  1304 . In the example of  FIG. 4 , the lower walls  1404  of the first guiding means are also upwardly tapering, but in another example of the invention, these walls can be substantially parallel. Furthermore, the second guiding means  1804  of the socket body  304  are shown. Said second guiding means  1804  comprises upwardly tapering upper outer walls  1904  and substantially parallel lower outer walls  2004 . In the example of  FIG. 4 , the lower outer walls  2004  of the second guiding means are upwardly tapering, but in another example of the invention, they may also be substantially parallel. The first guiding means  1204  of the lighting body  204  is adapted to fit to the second guiding means  1804  of the socket body  304  so that the upwardly tapering upper outer walls  1904  and the lower outer walls  2004  of the second guiding means  1804  interacts with the upwardly tapering upper walls  1304  and lower walls  1404  of the first guiding means  1204 , and thus contributes to guiding the lighting body  204  towards the socket body  304  especially in horizontal direction at least when the lighting body  204  moves from a second open position to a closed position by allowing a relative motion between the lighting body  204  and the socket body  304  only in elevation direction. 
     In  FIG. 4 , arrows are showing the movement in azimuth direction by the angle beta β.  FIG. 5  shows an example of a lighting body  205  seen from below, wherein a first electrical connection  705  is arranged on the lighting body  205 . In the example of  FIG. 5 , the first electrical connection  705  has two terminals, but the first electrical connection  705  may also comprise more terminals depending on which functions the lighting device is equipped with. The first electrical connection  705  is arranged to be able to interact with a second electrical connection, arranged on the socket body. 
       FIG. 6  shows an example where a lighting body  206  is about to be arranged on a socket body  306 , where the socket body  306  further is arranged on a holder  1106 .  FIG. 6  shows the lighting device  106 , with constituent parts, in cross-section. 
       FIG. 7  shows how the lighting body  206  according to  FIG. 6  is about to be arranged in a first open position  2106 . At the fitting of the lighting body  206  to the socket body  306  at this stage of the arrangement of the lighting body  206  to the socket body  306 , the first fastening device  1506  of the lighting body  206  interacts with the second fastening device  2206  of the socket body  306  so that the lighting body  206  is corrected in lateral and longitudinal direction relative to the socket body  306 .  FIG. 7  shows the lighting device  106 , with constituent parts, in cross-section. 
     Furthermore, in  FIG. 7  can be seen a marked centre line of the lighting body a and a centre line of the socket body b. The distance between the longest distance along the centre line of the lighting body a and the first fastening device  1506  and the longest distance along the centre line of the socket body and the second fastening device  2206  provides a first minimum distance  1   a - b.    
       FIG. 8  shows how the lighting body  206  according to  FIG. 6  and  FIG. 7  is in a first open position  2106 . In this first open position  2106 , the internally located contact surface  606  of the lighting body  206  bears against the projecting socket part  506  of the socket body  306 , which means that the first fastening device  1506  of the lighting body  206  interacts with the second fastening device  2206  of the socket body  306 , which allows a rotational relative motion between the lighting body  206  and the socket body  306  both in azimuth direction and elevation direction and simultaneously locks a relative motion between the lighting body  206  and the socket body  306  in longitudinal direction.  FIG. 8  shows the lighting device  106 , with constituent parts, in cross-section. 
       FIG. 9  shows how the lighting body  206  according to  FIG. 6 ,  FIG. 7 , and  FIG. 8  is in a second open position  406 . When the lighting body  206  moves from the first open position to the second open position  406 , the distance between the lighting body  206  and the socket body  306  being smaller in the second open position  406  than in the first open position, the first guiding means of the lighting body  206  interacts at least with the second guiding means of the socket body  306  as to correct the lighting body  206  in horizontal direction relative to the socket body  306 .  FIG. 9  shows the lighting device  106 , with constituent parts, in cross-section. 
     Furthermore, in  FIG. 9  can be seen a marked centre line of the lighting body a and a centre line of the socket body b. The distance between the longest distance along the centre line of the lighting body a and the first fastening device  1506  and the longest distance along the centre line of the socket body and the second fastening device  2206  provides a second minimum distance  2   a - b.    
       FIG. 10  shows how the lighting body according to  FIG. 6 ,  FIG. 7 ,  FIG. 8 , and  FIG. 9  is in a closed position  2306 . Furthermore,  FIG. 10  shows how the first electrical connection  706  of the lighting body  206  is connected to the second electrical connection  806  of the socket body, and how the first locking member  906  of the lighting body  206  of this example of the inventive lighting device  106  is interlocked with the second locking member  1006  of the socket body  306  of this example of the inventive lighting device  106 . In the example according to  FIG. 6 ,  FIG. 7 ,  FIG. 8 ,  FIG. 9 , and  FIG. 10 , the first locking member  906  is in the form of a from the lighting body  206  projecting resilient flange, and the second locking member  1006  is only in the form of a on the socket body  306  situated contact surface which the first locking member may bear against, but also other constructions of the first locking member and the second locking member are possible.  FIG. 10  shows the lighting device  106 , with constituent parts, in cross-section. 
       FIG. 11  shows an example of a socket body  307  seen from above, wherein the socket body  307  according to the example is arranged on a holder  1107 . Furthermore,  FIG. 11  shows an example of the projecting socket part  507  of the socket body  307  and the second electrical connection  807  of the socket body  307 . In the example according to  FIG. 11 , the second electrical connection  807  has two terminals, but the second electrical connection  807  may also comprise more terminals depending on which functions the lighting device is equipped with. The second electrical connection  807  is arranged to be able to interact with a first electrical connection, arranged on the lighting body. It is also shown how the second electrical connection  807  is connected to cables  2407  and that one cable is earthed. In addition,  FIG. 11  shows that the socket body  307  has upwardly tapering upper outer walls  2507  and lower outer walls  2607 , which are part of the second guiding means  1807  of the socket body  307  exhibited in  FIG. 11 . In the example according to  FIG. 11  are also the lower outer walls  2607  upwardly tapering, but in other examples of the inventive lighting device, these can be substantially parallel. 
       FIG. 12  shows another example of a socket body  308  seen from above, wherein the socket body  308  according to the example is arranged on a holder  1108 . Further,  FIG. 12  shows another example of the projecting socket part  508  of the socket body  308  and the second electrical connection  808  of the socket body  308 . In the example according to  FIG. 12 , the second electrical connection has three terminals. In addition,  FIG. 12  shows that the socket body  308  has upwardly tapering upper outer walls  2508  and lower outer walls  2608 , which are part of the in  FIG. 12  exhibited second guiding means  1808  of the socket body  308 . In the example according to  FIG. 12  are also the lower outer walls  2608  upwardly tapering, but in other examples of the inventive lighting device, these can be substantially parallel. 
     REFERENCE SIGNS 
     
         
           101 - 104 ,  106  lighting device 
           201 - 206  lighting body 
           301 - 302 ,  304 ,  306 - 308  socket body 
           401 - 402 ,  406  second open position 
           501 - 502 ,  506 - 508  projecting socket part 
           601 - 603 ,  606  internally located contact surface 
           702 ,  705 - 706  first electrical connection 
           802 ,  806 - 808  second electrical connection 
           902 ,  906  first locking member 
           1002 ,  1006  second locking member 
           1102 ,  1106 - 1108  holder 
           1203 - 1204  first guiding means 
           1303 - 1304  upper walls 
           1403 - 1404  lower walls 
           1503 ,  1506  first fastening device 
           1603  rear wall 
           1703  hook portion 
           1804 ,  1807 - 1808  second guiding means 
           1904  upper outer walls 
           2004  lower outer walls 
           2106  first open position 
           2206  second fastening device 
           2306  closed position 
           2406  cables 
           2507 - 2508  upper outer walls 
           2607 - 2608  lower outer walls 
           1   a - b  first minimum distance 
         a centre line of the lighting body 
           2   a - b  second minimum distance 
         b centre line of the socket body