REFLECTOR SYSTEM FOR SECURING TO A LIGHT SOURCE

Abstract: When it is desired to increase the light yield from fluorescent tube installations without reflectors by providing the fluorescent tubes with a reflector, it is often difficult to mount and position the reflector in an existing light fitting, and it is even more difficult when such fluorescent tubes sit freely on a wall or a ceiling, or are mounted externally on a fitting. For this purpose the reflector system comprises a reflector (4) of anodized aluminium and securing elements (1) consisting of spring straps which surround the fluorescent tube (5) and secure the reflector (4) to the fluorescent tube by means of friction between the securing element's strap (1) and the fluorescent tube (5). Also provided is a second embodiment of the securing element which is intended for fittings with a flat surface. In this case the securing element has some protruding ends which bear against the flat surface of the fitting and thus position and secure the reflector in the correct position.

Description: REFLECTOR SYSTEM FOR SECURING TO A LIGHT SOURCE This invention relates to a reflector system for sec¬ uring to a light source as presented in the introduc- tion of claim 1. Reflectors for lighting purposes are most often man¬ ufactured of anodized aluminium plate and are secured to the light fitting, in that the reflectors are nor- mally produced especially for use in connection with the individual types of fittings. However, many light sources are to be found, for exam¬ ple fluorescent tubes, which are mounted in fittings without reflectors or which are disposed freely out¬ side the fitting. When for reasons of increasing en¬ ergy prices it is desired to increase the illumina¬ tion without exchanging the lamps for lamps having a greater energy consumption, one can provide them with suitable light ' reflectors. In order to make the assem¬ bly independent of the shape of the fitting, it is most expedient for the reflector to be mounted dir¬ ectly on the light source. Reflectors for mounting directly on to fluorescent tubes are known, for example executed in plastic mat¬ erials and provided with various means of reflection. It is, however, more expedient to produce the reflec¬ tor of anodized pure aluminium, the reason being that this material is more robust and stable in shape and, furthermore, its reflecting characteristics are more durable. In the following, the invention is explained in con- nection with the use of an elongated light source, and a normal fluorescent tube has been chosen as an example. The actual cross-sectional curve of the reflector, which does not form a direct part of the present in¬ vention, conforms mainly to that shape known, for ex¬ ample, from British patent no. 884,068, the lower part of the reflector cross-sectional curve turning downwards to form a light output aperture which stron¬ gly reduces the light intensity immediately outside an angle which is desired to limit the transmission of light transversely to the fitting. The shape of this part of the reflector cross section is known from ... textbooks and from pending Danish patent application no. 5775/76. However, between these two parts of the reflector cross section there is inserted a straight part, or an approximately straight part, from that point on the involute curve to the light source cross section in the same plane, from which a half-tangent to the light source is parallel — for symmetrical reflectors — to the plane of symmetry. This straight part in the reflector cross section con¬ tinues so far that the light intensity in directions near the reflector τ s plane of symmetry is so much less than the intensity of light at greater angles from the plane of symmetry that the light transmission results in a focal point relationship which, according to the BZ system, is greater than 0.7 at S/Hm = 1.5. Therefore, there is no real continuity in the trans¬ itR E A OMPI ition between the types of curves used, and several of the remaining characteristics displayed in the shaping of the reflector according to Danish patent application no. 5775/76 do not apply to the reflector as described here. The reflector system according to the invention will, however, display optimum characteristics with regard to energy loss, outer dimensions and glare,, and also the improvement in the application possibilities which lies. ' i .-the fact;that__it_will_ " provide good regularity in the illumination, even when the light fittings hang spread with S/Hm = 1.5. This improvement is necessary for.the reason that the regularity of the illumination must not be diminished in the mounting of reflectors on existing installa¬ tions. Reflectors of the above-mentioned shape are difficult to mount in existing fittings which do not already have reflectors, and on completely freely-disposed fluorescent tubes. The object of the invention is to provide a reflector system consisting of a reflector of the correct shape, for example of anodized aluminium plate, which is cheap to produce, and also to provide securing elem¬ ents which are similarly simple and thus also cheap to produce. Moreover, with lighting installations, it is important that after having been fitted with re¬ flectors that the installation.maintains a reasonable aesthetic standard, and at the same time that the re¬ flector system is simple and quick to mount. liURHAt OMPI This is achieved by forming the reflector system as characterized in claim 1. If the light source is of the type which sits in a fitting, in certain cases one can utilize a flat sur¬ face in the fitting so that the reflector sits cor¬ rectly in relation to the light source, and at the same time it will be correctly positioned in relation to the fitting and the direction of illumination. This is effected in an expedient manner by designing the securing element for the reflector system as pre¬ sented, in claim 2. If, however, the light source sits freely outside the fitting or externally on the fitting, or if the fit¬ ting does not have a reasonably flat surface of con¬ tact, the reflector system according to claim 3 can be used r in that here, it is secured exclusively on the light source. By designing the reflector system's securing element as presented in claim 4, it is possible to secure the reflector without the securing element actually clamp¬ ing around the fluorescent tube, but instead being merely supported by the fluorescent tube. On the other hand, if the reflector system's securing element is designed as presented in claim 5, the resτ ult is that the securing element clamps tightly around the fluorescent tube and, in this manner, tightly se¬ cures the reflector. As presented in claims 6 and 7, the securing element is provided with gripper recesses, whereby a well-de- -£URE OMPI fined friction is achieved between the strap of the securing element and the fluorescent tube it sur- ... " rounds. The invention will now be described with reference to the drawing, where fig. 1 shows a reflector system according to the invention in an embodiment intended • for securing directly on to a fluorescent tube, fig. 2 shows a securing element for the reflec¬ tor system shown in fig. 1, fig. 3 shows a reflector system according to the invention in an embodiment intended for securing to a fluorescent tube moun¬ ted in a fitting, and fig. 4 shows a securing element for the reflec¬ tor system shown in fig. 3. In sketch form in figs. 1 and 2 will be seen a reflec- tor system intended for mounting directly on, for ex¬ ample, a fluorescent tube which sits .freely mounted,., for example on a wall or a ceiling, or externally on a fitting. One or more securing elements surround the fluorescent tube and are secured to the reflector 4 in assembly holes 8. The assembly hole 8, also called the gripping hole, is formed and positioned in the reflec¬ tor's lengthwise central axis and is shown in detail in the segment drawing 10 in the circle above fig. 1 itself. The securing element 1 has gripping recesses 13 at the ends at which the securing element is bent, thus enabling it to be secured in the assembly hole 8 as shown in fig. 1. The securing element surrounds the fluorescent tube 5 with sufficient friction to secure the reflector 4 in a certain position. This friction, however, is no greater than one can turn the reflector 4 if this has been placed in a slightly crooked manner on the light source. Together with that part of the securing element which surrounds the light source, it is the bent ends la which at point 12 have flexible connection with the light source which provide the necessary friction. The bent ends of the securing el¬ ement, see fig. 2, reach right in and support against that part of the securing element which lies as a tan- gent to the fluorescent tube, see fig. 1. In figs. 3 and 4 is shown a second embodiment of the invention, this embodiment being particularly suitable for mounting on fluorescent tubes which are placed in a fitting with a flat surface, which in the drawing is represented by the stippled line in fig. 3. For the sake of clarity, in fig. 3 the reflector system is shown as seen directly from the one end of the fluor¬ escent tube. Here, the reflector 4 is secured by a securing element 2, see fig. 4, which surrounds the light source 5 and passes through a hole in the re¬ flector. At point 6 the reflector is held firmly in the gripping recesses 13 in the securing element 2 which bears against the fitting 9 at.points 7. The securing element substantially surrounds the light source so that there is no friction against the light source, in that the reflector 4 will Of course..always sit in the correct position. When the ends 2a of the securing element 2 bear up against the fitting 9, they OMPI are influenced in such a way that they slide slightly away from each other. The pressure with which the re¬ flector 4 and the securing element 2 lie up against the fluorescent tube is determined by the moment which arises due to the flexible contact of the quite long and springy ends against the fitting. The reflectors 4 used in the embodiments shown in both fig. 1 and fig. 3 are the same, in that the holes pro- vided in the reflector 4 are of such a shape that the gripping recess 13 in the securing element 1 or 2 en¬ gages in the holes 8. The securing elements as shown in figs. 2 and 4 are also essentially the same, their bent ends la and 2a merely being bent differently. The length of the securing element naturally depends on the type of light source on which the reflector is to be mounted. The securing element is normally made of metal, for example thin metal plate of spring steel, but other flexible materials can also be used. Although the invention has been explained and shown in connection with a fluorescent tube, it is obvious that the reflector system according to the invention can be used on other types of elongated light sources. The reflector 4 can also be of.other expedient^shapes. It merely needs to be provided with suitable holes so that it can be secured by the gripping recesses 13 in the securing elements. JΪT E OMPI • * - -

Claims: C A I M S 1. Reflector system for securing to an elongated light source (5) , for example a fluorescent tube, com- prising a reflecting metal reflector (4) which is mounted above the light source (5) and secured direct¬ ly to said light source by means of one or more secur¬ ing elements (1, 2) , each of which consists of a nar¬ row, flexible metal strap with an essentially circu- lar part arranged to partly surround the light source (5), c h a r a c t e r i z e d in that both ends (la, 2a) of the circular part are provided with a holding element for securing the reflector (4) which is pro¬ vided with a hole (8) for each securing element (1,2) . 2. Reflector system according to claim 1, c h a r ¬ a c t e r i z e d in that each end of the circular part of the securing element has ends (la) bent in to¬ wards the arc of the circle, and also a gripping re- cess (13) so that the bent ends (la) pass back thro¬ ugh the hole (8) in the reflector (4) , and the grip¬ ping recess (13) engages in the hole (8) in the re¬ flector. 3. Reflector system according to claim 1, c h a r ¬ a c t e r i z e d in that each end of the securing element has protruding ends (2a) and a gripping recess (13) , and also in that the protruding ends (2a) are of such a length that they can lie up against a wall (9) in the fitting in which the light source (5) is mount¬ ed, in that the gripping recess (13) engages in the hole (8) in the reflector. 4. Reflector system according to claims 1 - 3, _0MPI, < c h a r a c t e r i z e d in that the extreme ends of the securing element (1, 2) are rounded off with a further bend. OMPI 4 A

Inventors: ANDREASEN KNUD, ANDREASEN, KNUD
Applicants: ANDREASEN KNUD, ANDREASEN, KNUD
Application year: 1982
Main classification: F21V17
IPC codes: F21V7, F21V17