Patent Publication Number: US-9841176-B2

Title: Lamp

Description:
PRIORITY CLAIM 
     The present application is national phase application of and claims priority to International Application No. PCT/EP2013/002432 with an International filing date of Aug. 13, 2013. The foregoing application is hereby incorporated herein by reference. 
     TECHNICAL FIELD 
     The invention relates to a lamp comprising a housing, a light source arranged in the lamp housing, a reflection device associated with the light source for deflection of light emitted by the light source in the direction of a light outlet opening of the housing, and a cooling device associated with the light source and/or the housing. 
     BACKGROUND 
     Such a lamp is known, for example, from DE 10 2011 017 161. 
     A specific LED carrier is in the known lamp provided for LEDs as a light source. In addition, a separate lamp reflector is used for indirect light emission, where the lamp reflector is composed of a number of substantially linear and curved reflector surfaces. Cooling fins are arranged on the LED carrier as part of a cooling device. 
     A respective lamp housing is arranged around all these devices. 
     SUMMARY 
     In order to simplify the structure of such a lamp and at the same time to provide a lamp which at least with regard to cooling and emission of light fulfills the requirements in the above-mentioned prior art, the invention is based on the object to improve a lamp of the type mentioned above in that the lamp structure is simplified and the number of individual components of the lamp is reduced without disadvantages arising in terms of, for example, cooling or light emission from the lamp. 
     This object is satisfied by the features of claim  1 . 
     The lamp according to the invention is in particular characterized in that an inner side of the lamp housing is formed, at least in some locations, as a reflection device and/or the cooling device is formed in one piece with the lamp housing. 
     This means that at least the reflection device or the cooling device is formed in one piece with the lamp housing, where either of these devices can be formed directly by the lamp housing. 
     For example, it is not necessary to allocate a separate cooling device to the light source or to arrange a separate reflection device within the lamp housing. 
     It is in a simple embodiment conceivable that the reflection device is formed as a coating on the inner side of the lamp housing. Depending on the material of the lamp housing, it is also conceivable that, for example, a polished inner side of the lamp housing is used as a reflection device. The reflection device is in particular arranged within the lamp housing such that light from the light source is deflected in the direction toward the light outlet opening. It can there prove to be sufficient, if, for example, only a portion of the inner side is formed as a reflection device. 
     Lamps are commonly used, for example, as linear lamps which have a greater length than width. It can in this context be advantageous if, for example, the housing is formed substantially semi-cylindrical, where the reflection device is at least in some locations formed along the curved half-cylindrical casing on its inner side. 
     To protect the interior of the lamp and in particular the lamp housing from contamination or from external intervention, the light outlet opening can be covered by a translucent or transparent cover plate. In can in this context further prove to be advantageous if the cover plate is at least supported on bearing edges encircling the light outlet opening. Such a support can be effected from the interior of the lamp housing, so that the cover plate does not protrude outwardly beyond the light outlet opening. For connecting the cover plate with the bearing edges, for example, a detachable connection or an adhesive bond or the like can be provided. 
     The bearing edges can there extend linearly or have other shapes, for example, in order to configure the light outlet opening as required. 
     Fluorescent tubes, halogen lamps or the like can be used as a light source, where preferably the use of a light source composed of a plurality of LEDs arranged on a circuit board is conceivable. 
     For uniform light output and sufficient lifespan, such LEDs commonly require relatively good cooling which is ensured by the cooling device integrated into the lamp housing. There is no longer the need for separate cooling devices in the lamp housing with possibly support from fans or the like. 
     In addition, such LED&#39;s can be actuated in a simple manner to allow for different lighting conditions. 
     This can be supported by respective lenses or reflection device, where such a reflection device is according to the invention formed on the inner side of the lamp housing. In is in this context further pointed out that the respective cover plate of the light outlet opening can exhibit a lens effect. 
     The printed circuit board equipped with respective LEDs can be arranged and fastened in different ways within the lamp housing. The use of multiple printed circuit boards with respective LEDs is additionally possible. 
     It is in one embodiment of the invention conceivable that the cooling device is formed on an outer side of the lamp housing. There is also the option that the cooling device is provided on the inner side of the lamp housing or on both the inner side and the outer side of the lamp housing. 
     In a simple embodiment, the cooling device can be formed by a number of cooling fins protruding outwardly from the outer side of the lamp housing. The cooling fins can each be disposed at the same distance or at different distances from each other, where, for example, a greater concentration of cooling fins can be provided in the vicinity of the light source. 
     It is also possible that the cooling fins each have the same height and/or length. 
     Openings are in a semi-cylindrical lamp housing also provided at opposite longitudinal ends of the housing and can advantageously be covered in particular by end cover plates detachably fastened on the lamp housing. 
     For easy fastening of such end cover plates on the lamp housing, support flanges can protrude on either longitudinal end from the outer side of the lamp housing, where fastening screws can be passed through said support flanges for detachably fastening the oppositely disposed end cover plates. 
     Several of these support flanges are commonly disposed along the longitudinal ends. 
     It has already been pointed out that the light source or also the printed circuit board, respectively, can with the plurality of LEDs be disposed on the inner side of the lamp housing. This also applies when using multiple light sources or multiple printed circuit boards with a respective number of LEDs. 
     The light source can in one embodiment be arranged, for example, directly on the inner side of the lamp housing. There is also the option that the inner side of the lamp housing comprises bearing flanges protruding into the housing interior for detachably fastening the light source. Detachably fastened on such a bearing flange is, for example, the circuit board. 
     This also applies analogously to respective further electrical or electronic devices which are arranged in the housing interior. 
     In a simple embodiment, the bearing flange can extend along the light outlet opening. 
     It is in this context also advantageous if possibly the bearing flange forms at least a portion of the edge of the light outlet opening. The light source can in this manner be arranged adjacent to the light outlet opening, where the light it emits exits by way of the reflection device through the light outlet opening toward the exterior from the lamp housing. 
     It has already been pointed out that the respective cover plate can be placed on bearing edges of the light outlet opening. It is in this context further optionally advantageous if the bearing flange is formed with at least one of the bearing edges. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the following, an advantageous embodiment of the invention is further illustrated using the figures appended in the drawing, 
       where: 
         FIG. 1  shows a perspective view from below onto a lamp according to the invention and 
         FIG. 2  shows a cross-sectional view through the lamp according to  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS 
       FIG. 1  illustrates a lamp  1  according to the invention in a perspective view obliquely from below. Such a lamp  1  can be configured as a recessed ceiling emergency lamp, as an explosion-proof lamp and/or as a linear lamp. Lamp  1  has a semi-cylindrical lamp housing  2 , which on its underside comprises a light outlet opening  5  and also respective openings at longitudinal ends  19  and  20 . Respective end cover plates  21  being fixed to each other by way of fastening screws  23  are provided to cover the openings at longitudinal ends  19 ,  20 . In order to guide fastening screws  23  along an outer side  15  of lamp housing  2 , support flanges  22  are provided at longitudinal ends  19 ,  20  through which fastening screws  23  are guided. 
     End cover plates  21  are approximately semi-circular in shape. 
     On outer side  15  of lamp housing  2 , a cooling device  6  is further arranged in the form of a number of cooling fins  16 . These cooling fins  16  are formed in one piece with lamp housing  2 , see also  FIG. 2 . The cooling fins extend between the longitudinal ends over the entire length  18  of lamp housing  2  and each have the same height  17 , see again  FIG. 2 . 
     Light outlet opening  5  is closed by a transparent or translucent cover plate  10 . It rests from the housing interior  24  of lamp housing  2  on respective bearing edges  11 ,  12 , see  FIG. 2 . 
     A bearing flange  25  is along one side of light outlet opening  5  arranged with a corresponding bearing edge  11  which has a greater width as compared with oppositely disposed bearing edge  12 . At the uppermost point of lamp housing  2 , a suspension device  29  or a fastening device  29 , respectively, is further arranged with which lamp  1  can be fastened at the respective mounting location. 
       FIG. 2  shows a vertical sectional view through lamp  1  according to  FIG. 1 . 
     According to  FIG. 2 , five cooling fins  16  with height  17  and length  18 , see  FIG. 1 , extend on outer side  15  of lamp housing  2 . The cooling fins are arranged substantially equidistant, where, for example, support flanges  22  or suspension device  29  can be arranged between the cooling fins on lamp housing  2 . 
     In the housing interior  24  on an inner side  7  of lamp housing  2 , a reflection device  4  is formed It can be formed directly by inner side  7  of lamp housing  2  or also by a special reflective coating  8  of inner side  7 . Reflection device  4  can be formed on the entire inner side  7  or only in part thereon, to reflect in particular light from a light source  3  in the direction toward lamp outlet opening  5 , see the various light beams  27  according to  FIG. 2 . 
     Light source  3  is arranged on bearing flange  25  as part of an edge  26  of light outlet opening  5 . Light source  3  is in the embodiment illustrated formed by a plurality of LEDs  13  being arranged on a printed circuit board  14 . The latter is likewise directly connected to the respective bearing flange  25 , for example, by adhesive bonding or the like. 
     It is at this point to be noted that a similar arrangement of a light source  3  can also be disposed on the opposite side of light outlet opening  5  so that respective light sources  3  can be provided on either side of light outlet opening  5 . 
     According to  FIG. 2 , cover plate  10  is placed from the direction of housing interior  24  on respective bearing edges  11  and  12  of light outlet opening  5 . Cover plate  10  can also be fastened, for example, by a detachable connection or the like. 
     In the embodiment illustrated, bearing edge  11  forms a portion of bearing flange  25 , where a rib  30  extends vertically upwardly from bearing flange  25  into the housing interior for separating light source  3  from light outlet opening  5 . 
     It also serves to fixate light source  3  and in particular circuit board  14  with LEDs  13  disposed thereon. 
     First heat dissipation from LEDs  13  can occur via the printed circuit board. There are a number of options for this. For example, special printed circuit board shapes can be used which exhibit particularly good thermal conductivity, such as printed circuit boards having a metal core. The heat of the LEDs can be passed, for example, to the metal core via a copper through-contact. The heat can then from the metal core be passed on directly to the lamp housing. Thermal conductivity can in this context be improved by heat-conductive paste or the like. Moreover, it is in this context of advantage if respective heat transfer is improved by mounting the printed circuit board without the surfaces to be joined being uneven and rough. 
     Due to the shape of lamp housing  2 , the respective wall is formed substantially as a half-cylindrical casing  9 , see also  FIG. 1 . This half-cylindrical casing comprises inner side  7  and outer side  15 , respectively. 
     There is the further option that printed circuit board  14  is not placed directly on the upper side of bearing flange  25 , but that, for example, a separation layer  28  is further disposed between them. It can also be formed as a heat conduction layer to enable improved heat transfer from sides of light source  3  in the direction of cooling device  6 . 
     Lamp  1  according to the invention exhibits a simple structure with reflection device  4  and cooling device  6  being integrated in lamp housing  2 . No additional devices for cooling or reflection are necessary, such as a cooling element, a fan, a holder separate from the lamp housing for the light source and the like. 
     Furthermore, devices for fastening end cover plates  21  or for fastening lamp  1 , respectively, are already formed on at the lamp housing itself, cf. suspension device  29 . 
     A lamp of an overall compact structure being composed of few individual components arises which can be inexpensively and quickly produced and is versatile in use. The respective bearing flange  25  for arranging circuit board  14  is in the embodiment illustrated indeed formed as a part of edge  26 , where it is also conceivable that the respective cover plate  10  of light outlet opening  5  can be placed only on bearing edges  11  and  12 , where, for example, the corresponding bearing flange  25  can protrude also elsewhere from inner side  7  of lamp housing  2  into the housing interior. This gives rise in a simple manner to different arrangement options for the light source, where also several such light sources can be disposed by way of several bearing flanges in one lamp housing  2 .