Abstract:
The invention relates to a lamp ( 1 ) comprising a projector ( 3 ) and an adjustable holding device ( 5 ), by means of which the projector ( 3 ) is joined to a base part ( 2 ) of the lamp ( 1 ). The holding device ( 5 ) is provided with an elongate support element ( 6 ), a holding element ( 7 ) at least for part of the projector ( 3 ), a joint ( 8 ) between the support element ( 6 ) and the holding element ( 7 ), and a clamping device ( 9 ) for locking the joint ( 8 ). The joint ( 8 ) and the clamping device ( 9 ) are disposed in a projector housing ( 11 ). In order to ensure that the projector ( 3 ) is easy to handle for adjustment purposes, a removing mechanism ( 41 ), with the aid of which the clamping force of the clamping device ( 9 ) can be reduced or canceled, is arranged in the projector housing ( 11 ). Said removing mechanism ( 41 ) is accessible from outside the projector housing ( 11 ) in order to be manually manipulated while being provided with a manually actuated actuating element ( 42 ) which is located at a distance next to a supporting element ( 49 ) that is fixed to the housing. The actuating element ( 42 ) can be moved towards the supporting element ( 49 ) by having two fingers of an operator&#39;s hand engage over both elements ( 42, 49 ).

Description:
FIELD OF THE INVENTION 
   The invention relates to a luminaire comprising a spotlight and an adjustable holding device for a spotlight. 
   BACKGROUND OF THE INVENTION 
   Known in the art, in the case of luminaires comprising a spotlight, and unlike the case of luminaires installed in a fixed manner, is the practice of holding the spotlight by means of a holding device which comprises an articulated joint disposed between, on the one hand, a carrying element attached to a base part and, on the other hand, a holding element for at least a portion of the spotlight. A clamping device is associated with the articulated joint for the purpose of locking the latter, such that the clamping force is sufficient to lock the spotlight in the set position. Depending on the magnitude of the clamping force that is present, it is possible, in the case of such a clamping device, to adjust the spotlight by manually applying pressure to overcome the clamping force of the clamping device. This, however, requires a manual expenditure of force which may overload the clamping device and, in addition, a relatively large amount of frictional wear occurs in the case of such an adjustment. 
   Known from U.S. Pat. No. 6,079,992 is a spotlight luminaire of the generic type in which the clamping device can be released by means of a release device. This release device can be actuated by means of an outwardly projecting lever, in which case, however, it is necessary to keep hold of the spotlight with the other hand. 
   SUMMARY OF THE INVENTION 
   The invention is now based on the object of designing a luminaire according to the preamble of claim  1  or a holding device according to the preamble of claim  4  in such a way that it can be adjusted with easy manipulation. 
   This object is achieved by the features of claim  1  or  4 . Advantageous developments of the invention are described in associated sub-claims. 
   In the case of the luminaire according to claim  1 , there is disposed in the spotlight housing a release device which can be used to reduce or remove the clamping force of the clamping device, the release device being accessible from outside the spotlight housing in order that it can be operated manually. It is thereby possible, through manual operation, to remove the clamping force of the clamping device, or at least to reduce it to such an extent that it is possible to adjust the spotlight with easy manipulation in a manner that does not damage the clamping device or the articulated joint. This design thus enables the spotlight to be adjusted with easy manipulation in a non-damaging manner. A long service life is thus achieved, because wear is prevented or at least reduced. 
   The particular ease of manipulation is achieved, according to the invention, in that manual operation of the release device can be effected directly from outside the spotlight housing. This is effected by means of an actuating element which is accessible from the outside and is disposed, for example, in an aperture of the spotlight housing, said actuating element being such that it can be manually gripped and actuated in a direct manner, and being disposed at a distance next to a supporting element which is solid with the housing. This design makes it possible to grip both elements, for example with two fingers of the operating hand, and thereby to move the actuating element into its release position, towards the supporting element. In so doing, it is possible to adjust the spotlight at the same time, such that no special access is required. 
   In the case of the design according to the invention as stated in claim  4 , the articulated joint additionally permits adjustment about at least two axes, means being provided for manually releasing the clamping device without use of tools only for the time of adjustment of the articulated joint. This design is also advantageous if the holding device is not disposed in a housing. This design, likewise, is distinguished by ease of manipulation, the clamping device being releasable by direct manual operation only for the time of adjustment, such that, following the manual release, the clamping device becomes operative automatically and locks the articulated joint. 
   Suitable for the designs according to the invention is a ball-and-socket joint, which is spatially adjustable about any number of axes and provides for a large adjustment range. A sufficient adjustment range with sufficient adjustment possibilities is also achieved if the articulated joint permits adjustment about only two axes. These axes may run, for example, at right angles to one another, as is the case with a ball-and-socket joint, the ball of which is mounted between two laterally mutually opposing articulated-joint shells and which can be clamped, by lateral pressure, on to at least one of the two articulated-joint shells. This clamping force can be achieved in a simple manner by a spring, in particular a compression spring. In the case of such a clamping device, moving the compression-loaded articulated-joint shell contrary to the spring force causes the clamping device to be released. This can be effected with use of an appropriate means, e.g. a release device. 
   A luminaire of the present type is also subject to requirements in respect of its appearance, since it is intended for use in rooms frequented by people. For this reason, it is advantageous for the holding device for the spotlight to be disposed in a housing to such an extent that the articulated joint and the clamping device are accommodated in the housing, and are thus taken out of view. 
   The invention is therefore furthermore based on the object of designing a luminaire according to the claims of the present invention in such a way that a simple structure is achieved, while ensuring that the radiation of light can be set in a manner appropriate to the room. 
   This object is achieved by the claims of the present invention. Advantageous developments of the invention are described in associated sub-claims. 
   In the case of the luminaire according to claims of the present invention, the carrying element extends through a slot in the spotlight housing, said slot, being continuous in a side wall of the spotlight housing, extending as far as into a top wall of the spotlight housing that faces away from the radiation directions of the spotlight. This design is simple because it requires only a slot in the spotlight housing in order to achieve sufficient adjustment of the spotlight. In this case, an adjustment range is achieved which extends as far as two radiation directions which are directed at right angles to one another and which between them enclose an approximately right angle or, also, obtuse angle. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Advantageous designs of the invention are explained more fully in the following with reference to a plurality of exemplary embodiments and drawings, wherein: 
       FIG. 1  shows a perspective side view of a luminaire according to the invention, comprising a spotlight and an adjustable holding device for the spotlight; 
       FIG. 2  shows the spotlight in a so-called exploded drawing of its partially disassembled parts; 
       FIG. 3  shows the spotlight in a position rotated by approximately 180°; 
       FIG. 4  shows a perspective representation of the holding device; 
       FIG. 5  shows a top view of the holding device; 
       FIG. 6  shows a top view, in partial section, of an articulated joint of the holding device. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   The main parts of the luminaire, denoted in its entirety by  1 , are a base part  2  for mounting the luminaire  1  onto a support such as a device, ceiling or wall, a spotlight  3 , from which the light is radiated in a main radiation direction  4  when in the switched-on state, and an adjustable holding device  5 , by means of which the spotlight  3  is connected to the base part  2  and is thereby carried in an adjustable manner. 
   The adjustable holding device  5  consists of a carrying element  6  which is attached to the base part  2 , a holding element  7  on which the spotlight  3  is held, an articulated joint  8  between the carrying element  6  and the holding element  7 , and a clamping device  9  for locking the articulated joint  8  in its respective articulation position. The holding element  7 , the articulated joint  8  and the clamping device  9  are located in a spotlight housing  11 , and are therefore not visible in  FIG. 1 , but are visible in  FIGS. 2 to 5 . 
   In the case of the exemplary embodiment, the carrying element  6  is an oblong component, e.g. a rod with, in particular, a round cross-section, preferably a tube, which is inserted in an approximately vertical hole  12  in the base part  2  that opens out on the underside of the latter, said carrying element being attached in a manner not represented. The tubular carrying element  6  may have a key width  13  in its free end region. 
   The articulated joint  8  is preferably a ball-and-socket joint having an articulated-joint ball  14  which is attached to the end of the tubular carrying element  6  that faces away from the base part  2 , the diameter of the ball being greater than the diameter of the tubular carrying element  6 . The articulated-joint ball  14  has a through-hole  15  which is coaxial with the tubular form and which, with the cavity of the tubular carrying element  6 , constitutes a cable duct through which at least one electric power cable, not represented, can extend to the light source disposed in the spotlight housing  11 , or to an electrical connection part of said light source. 
   The articulated joint  8  is constituted by the articulated-joint ball  14  and two articulated-joint shells  16 ,  17  which are disposed on either side of the articulated-joint ball  14 , and of which the articulated-joint shell  17  that is at the front in  FIG. 4  is biased against the articulated-joint ball  14  by a spring  18 , in particular a helical compression spring. Owing to the friction produced between the articulated-joint shells  16 ,  17  and the articulated-joint ball  14 , this biasing causes the articulated joint  8  to be locked in the respective articulation position. 
   By means of their shell recesses, which have the form of a portion of the ball and in which the articulated-joint ball  14  sits, the articulated joint shells  16 ,  17  define a first articulation axis  19 , which extends coaxially with the articulated joint shells  16 ,  17 . The spring  18 , which is likewise disposed coaxially with the articulation axis  19 , is supported coaxially at its other end on an articulated-joint web  21  which, when the spotlight  3  is in the vertical starting position represented in  FIGS. 2 and 3 , extends horizontally from the holding element  7  onto which it is releasably screwed, e.g. by means of a screw  22 . A second articulation axis  20  is constituted by the longitudinal central axis of the carrying element  6 , which central axis also extends through the articulation axis  19 . 
   The opposing articulated-joint-shell  16  may be realized as a single piece with an articulated-joint  23  web which is disposed on that side and which, for example, likewise extends as a single piece from the holding element  7  and, with the articulated-joint web  21 , constitutes an articulated-joint fork. The articulated-joint web  23  can be stabilized at its lower edge by a horizontal reinforcement web  23   a  which is formed integrally as a single piece on said articulated-joint web and the holding element  7 . 
   In the case of the present exemplary embodiment, the holding element  7  is a sleeve-type receptacle body  24  whose horizontal cross-section is of circular form in the starting position shown in  FIGS. 2 and 3 , and which has a downwardly open plug-in socket  25  into which a plug-in cap  26  can be inserted from beneath in a clamping manner, a parabolic reflector  27  being fitted on said plug-in cap, and the latter being able to carry a light source  28  disposed in the cavity of the reflector  27 , or to be constituted by the latter. The reflector  27  is located in the lower region of the spotlight housing  11 , being able to be inserted therein from above and to bear on a bearing web  29  disposed at the lower edge. 
   In the case of the present exemplary embodiment, the spotlight housing  11  consists of a lower housing part  11   a  and an upper housing part  11   b , which is realized with an upper-side top wall  31  in the form of a cap. The housing parts  11   a ,  11   b  can be fitted together and attached to one another in the region of their mutually facing edges. For this purpose, the one housing part may have in its edge region an outer annular groove  32 , and the other housing part may have an inner annular groove  33 , which can be inserted into one another so as to fit together, such that the two circumferential wall portions  34 ,  35 , which are of reduced diameter in the region of the annular grooves  32 ,  33 , overlap one another. In their mutually facing edge regions, the housing parts  11   a ,  11   b  can be releasably connected to one another by a connecting device, not represented in detail, preferably a quick-closing connection, e.g. a latching device or a bayonet fixing. 
   The holding element  7  is disposed and positioned, e.g. positively, in the spotlight housing, in this case essentially in the upper housing part  11   b . There may be integrally formed on the upper end of the receptacle body  24  one or more flange parts  36  which, in order to save weight, can be realized as hollow parts, and which can be used, for example, to position, and also to fasten, the holding element  7  in the spotlight housing  11 . 
   As shown by  FIGS. 4 and 5  in particular, the articulated joint  8  is located on the outside of the sleeve-type circumferential wall of the receptacle body  24 . At this location, there is sufficient free space for a pivoting motion of the holding device  5  relative to the carrying element  6  and for a relatively large angle W 1  of, for example, approximately 90°, or for an obtuse angle W 1 , as shown exemplarily by  FIG. 3 . 
   The holding device  5  fits, with the articulated joint  8 , into the free cavity of the spotlight housing  11 , or of the upper housing part  11   b , there being disposed in the circumferential wall  37  and in the top wall  31  a slot  38  which is wider than the cross-sectional dimension of the tubular carrying element  6 . In the top wall  31 , the slot end corresponds to the upright position of the tubular holding element  6 , and in the circumferential wall  37  the slot end corresponds to the position of the tubular carrying element  6  of the opposite angular position of the, for example, obtuse angle W 1  as shown in  FIG. 3 . When the luminaire  1  is in the mounted position shown in  FIG. 1 , the spotlight  3  can thus be pivoted with its main radiation direction  4  such that, when the main radiation direction  4  is in the downwardly pivoted position, its central axis  3   a  runs approximately parallel to the vertical second articulation axis  20  and, when in the other pivot position with the main radiation direction  4  directed sideways, it encloses an acute to obtuse angle W 1  with the second articulation axis  20 . In the position shown in  FIG. 1 , this angle W 1 , in which the main radiation direction  4  is directed obliquely downwards, is an acute angle. In the case of a right angle or obtuse angle W 1 , the main radiation direction  4  is directed horizontally or obliquely upwards, these not being represented. 
   The clamping force of the spring  18  or clamping device  9  is of such magnitude that, on the one hand, the spotlight  3  is locked against unintentional adjustment in each set position. In this case, adjustment can be effected with easy manipulation, by manually applying force to overcome the friction produced by the clamping force  9   a.    
   The luminaire  1  described thus far has the disadvantages that, on the one hand, force must be applied manually to overcome the clamping force and, on the other hand, wear occurs in the articulated joint in the case of such application. In order to avoid these disadvantages, the holding device  5  has a release device  41  with a manually actuated actuating element  42  by means of which the clamping force of the clamping device  9  can be reduced or fully removed, such that the adjustment of the spotlight  3  can be effected, on the one hand, in a more easily manipulated manner with a small amount of force and, on the other hand, without wear in the articulated joint  8  resulting from the clamping force. 
   In the case of the exemplary embodiment, the release device  41  acts upon the clamping element which is biased against the articulated-joint ball  14  by the force of the spring  18 , said clamping element being constituted here by the articulated-joint shell  17 . Upon actuation of the release device  41 , force is applied to the articulated-joint shell  17  against the force of the spring  18 , this resulting in reduction of the clamping force. When the articulated-joint shell  17  is lifted off, the clamping force is removed fully. 
   In the case of the exemplary embodiment, the release device  41  has a double-armed release lever  43 , which extends on the circumference of the holding element  7 , in this case the receptacle body  24 , at right angles to the central axis  7   a  of the holding element and, close to the circumference of the holding element  7 , is mounted in an articulated joint  44  so as to be pivotable about an articulation axis  44   a  such that its lever arm  43   a  facing towards the clamping device  9  can be moved along the direction of action of the clamping element of the clamping device. In the case of the exemplary embodiment, the articulation axis  44   a  extends in parallel to the central axis  7   a  of the holding element  7 , the lever arm  43   a  extending at right angles to the first articulation axis  19  and acting upon the articulation-joint shell  17 . Preferably two fork-type lever arms  43   a  are provided, which are disposed on the lower and upper side of the articulation-joint web  21  and are pivotally mounted on an articulation pin which passes through the articulation-joint web  21 . The free ends of the lever arms  43   a  are each connected to the articulated-joint shell  17  by a stud joint. In the case of the exemplary embodiment, mutually opposing driving pins  45  project from the articulated-joint shell  17 , the lever arms  43   a  engaging behind said driving pins, which preferably have recesses  46  which are open in the direction opposite to the clamping direction  9   a.    
   As viewed in the top view shown in  FIG. 5 , the articulated joint  44  is located in a plane E 1  which includes the central axis  7   a  of the holding element  7  and which, with a plane E 2  which includes the central axis  7   a  and the second articulation axis  20 , encloses an acute angle W 2  of approximately 45°. 
   From the articulated joint  44 , a long lever arm  43   b  extends to that side of the holding element  7  which is opposite the articulated joint  8 , said lever arm preferably following the curvature of the receptacle body  24  and thus rendering possible a small structure. At the free end of the lever arm  43   b  there is an actuating element  42 , in the form of an upright web  47  projecting to the side opposite the articulated joint  8 , said web being releasably connected to the free end of the long lever arm  43   b  by a connecting device  48 , e.g. a slip joint. Actuation by application of pressure in parallel to the clamping direction  9   a  causes the articulated-joint shell  17  to be moved contrary to the spring  18 , as a result of which the clamping effect is reduced or removed. 
   In order to further simplify actuation, there is disposed opposite the web  47 , at a distance, a supporting web  49 , which projects from the holding element  7 , in this case from the receptacle body  24 , and which, for example, is likewise releasably connected by a connecting device  48  to the holding element  7  or to an attachment thereof. The supporting web  49  provides for easily manipulated actuation of the actuating element  42  in that the web  47  is pressed against the supporting web  49 , e.g. by two fingers of an operating hand. This renders possible convenient single-handed operation, it being possible to simultaneously pivot the spotlight  3 . 
   Provided in the spotlight housing  11 , in this case in the upper housing part  11   b , in particular in the side opposite the articulated joint  8 , is a, for example, quadrangular aperture  51 , through which the web  47  or also—if provided—the supporting web  49  extends outwards to such an extent that said webs can be manually accessed and actuated from the outside. It is thereby possible for the holding device  5  to be completely covered and protected in a housing, in this case the spotlight housing  11 . In addition, this covering also gives the luminaire  1  a good appearance, as an enhancement. 
   In order, additionally, further to improve the appearance of the luminaire, it is advantageous for the aperture  51  to be realized as a whole, or as an aperture  51   a  widened in a step formation, in such a size that there is sufficient free space  52  ( FIG. 1 ) between the sides of the webs  47 ,  49  facing away from one another to permit gripping during actuation, e.g. with the two fingers of the operating hand. In the case of such a design, the webs  47 ,  49  can end within the aperture  51 , and need not project beyond the circumference of the spotlight housing  11 . 
   In order to prevent the cable, not represented, that extends through the tubular carrying element  6  from undergoing excessive rotation during rotation of the spotlight  3  about the second articulation axis  20 , it is advantageous to limit the extent to which the articulated joint  8  can be rotated about this second articulation axis  20 . This is achieved in that there is disposed in the articulated-joint ball  14 , in a plane E 3  extending at right angles to the second articulation axis  20 , a groove  53  in which there engages a stud  54  of one of the articulated-joint shells, in this case the articulated-joint shell  16 . As can be seen from  FIG. 6 , the groove  53  is not a full-perimeter groove, but extends over an angular range of less than 360°, such that its ends are at the distance c from one another shown in  FIG. 6 . 
   The at least one connecting device  48  is provided to facilitate or render possible mounting of the holding device  5  in the spotlight housing  11 . It is therefore possible to mount the holding device  5  in the spotlight housing  11  without the web or webs  47 ,  49 , and to mount the web or webs  47 ,  49  from the outside following assembly. 
   The arrangement of the supporting web  49  has the further advantage not only that the operating hand is able to grip both webs  47 ,  49  in an easily manipulated manner and actuate the release device  41 , but that secure gripping of the spotlight  3  as a whole is achieved, such that the latter can be pivoted into the desired radiation direction ( FIG. 4 ). Following release of the web  47 , the force of the spring  18  causes the clamping device  9  to go automatically into its clamping position, in which it locks the spotlight  3 . 
   On the side opposite the articulated joint  8 , the circumferential wall of the receptacle body  24  may have a continuous vertical slot  55  which, in the case of provision of an upper transverse wall  56 , may extend into the central region of the latter. The slot  55  may serve, for example, for the lateral insertion of an electric cable. The slot  55  is located, in particular, in the end region of the longer lever arm  43   b . Owing to the laterally open recesses  46 , it is therefore possible for the double lever  43  in  FIG. 5  to be pivoted downwards, in which case it releases the slot  55  for access. This is possible because, owing to the open recesses  46 , the short lever arm or arms  43   a  are able to pivot at the same time towards the plane E 2  and to pivot back to the driving pin  45 .