EP2989377B1 - Light cover for an elongate illumination system - Google Patents

Description

The present invention relates to a luminaire cover, which is intended for use in an elongate lighting arrangement, in particular in so-called light bands.

For example, the EP 2 042 802 A1 a luminaire with cover profile.

A light band is understood to mean a lighting arrangement which extends continuously over a very great length in comparison to individual lamps. Such light bands can be used both as an installation variant as well as in the form of surface-mounted lights or suspended lights. As a rule, they have a support element extending over the entire length of the arrangement, which consists of several segments or modules and serves for mounting or arrangement on or in the ceiling as well as the position of all essential components for the light emission. As a rule, such carrier elements are U-shaped, wherein the longitudinal channel formed in this case serves to accommodate the light sources and the operating devices required for operating the light sources. The underside of the channel is then closed by a cover which forms the light emitting surface of the light band and has corresponding optical properties in order to realize the light output in the desired manner. The cover can be designed both light-scattering and include components with which the light is selectively delivered in certain angular ranges.

With regard to the cover mentioned, however, there is the problem that the corresponding elements can realistically only be produced up to a certain length. Usually, these are elements made of plastic, which are produced by injection molding or by extrusion and, if necessary, have very little flexibility. They are therefore usually produced in certain standard lengths, although a corresponding light band can extend over a much greater length. In this case, then several such covers must be strung together, resulting in Consequence has that at the transition areas between two adjacent covers joints in the light exit area arise, which can have a negative effect on the light output. Although it is attempted to counteract this by the end faces of the covers are formed such that they overlap slightly overlapping each other, despite all in this transition region emerging light beams are inevitably influenced something different, so that such joints are still at least easily recognizable. Among other things, this is due to the fact that with temperature fluctuations, the covers extend differently compared to the existing metal housing and accordingly can be easily moved relative to each other during operation, so that in certain situations, the joints are even more clearly visible.

Although it would be theoretically conceivable to create covers in one piece, which extend over the entire length of the light band away. However, then there is the problem that several meters long covers can be transported to the final site difficult.

The present invention is therefore based on the object to provide a novel solution for the realization of a corresponding lamp cover for the elongated lighting arrangements described above, in which the one hand said problems are avoided and on the other hand satisfies the quality of the light output with the help of Lichtabstrahlelements highest standards.

The object is achieved by a lamp cover, which has the features of claim 1. Advantageous developments of the invention are the subject of the dependent claims.

The solution according to the invention is based on the idea of integrally forming the cover over the entire length of the light band, but to use different materials for different areas or components of the cover. Thus, it is provided in particular that the cover consists of an elongated, plate-shaped Lichtabstrahlelement, which is formed substantially flat. On both sides of the On the other hand, light-emitting elements are arranged fastening profiles, with the aid of which an attachment to the lamp housing takes place. According to the invention, the fastening profiles are formed from a material which is more flexible than the material of the light emitting element.

Accordingly, the invention proposes a lamp cover for an elongate lighting arrangement, which has a substantially plate-shaped, elongated Lichtabstrahlelement and arranged on the longitudinal sides of the Lichtabstrahlelements fastening profiles, which are provided for fastening the lamp cover to a lamp housing, wherein the Lichtabstrahlelement and the mounting profiles are made of different materials and the material of the fastening profiles is more flexible than the material of the Lichtabstrahlelements and wherein the lamp cover is designed in one piece.

The solution according to the invention makes it possible to manufacture the luminaire cover according to the invention in any desired lengths, in particular also endlessly. The decisive advantage, however, is that due to the plate shape of the Lichtabstrahlelements and the different choice of materials for the components of the lamp cover there is the possibility to bend the cover at least to a certain extent and thus also roll up. When rolled up, even an extremely long light cover can be easily transported to the place of use and, where appropriate, shortened to the required length. This opens up the possibility of realizing a one-piece light cover extending over the entire length of a light band. At the same time, a material can be selected for the light emitting element, which meets the optical requirements with respect to a high-quality light output.

Preferably, the fastening profiles extend over the entire length of the Lichtabstrahlelements. In this case, they can each form one or more webs which are aligned substantially perpendicular to the plane of the light emitting element. Even in this configuration, the previously described rolling up of the lamp cover is still possible because the flexibility of the material for the Fixing profiles allows this. If, on the other hand, the fastening profiles were to be formed of a rigid material or of the material of the light-emitting element, a corresponding rolling up of the cover would be impossible and it would again the problem exist that the cover can be transported only in the extended state, which - as mentioned above - from certain lengths is almost impossible.

The material used for the optically active hard component, that is to say for the light-emitting element, is preferably PMMA or PC or another material which has suitable optical properties and gives the light-emitting element a certain intrinsic stability. PMMA and PC are materials that are widely used in lighting technology to realize light emitting elements. In any case, these materials allow the realization of a Lichtabstrahlelements having the desired optical properties. As a soft component for the fastening profiles, however, preferably a thermoplastic elastomer is used whose optical properties are irrelevant to the luminaire cover. At the same time, however, this material is sufficiently flexible to allow the cover to roll up.

The use of a more flexible material for the fastening profiles also brings with it the advantage that - in the event that the fastening profiles extend over the entire length - a very good seal between the cover and the lamp housing can be achieved. This also means that the cover reliably prevents the penetration of dirt, dust or moisture into the interior of the light band. At the same time a very stable holder is guaranteed to the lamp housing, which is relevant insofar as after unrolling the cover this may still slightly bent and ensure the appropriate forces between the lamp housing and mounting profiles that the cover as desired consistently aligned or fitting to the housing can be arranged.

According to a development of the invention, the light emitting element can be provided with a light-influencing structure. This can be formed for example by a glued foil.

Fig. 1

schematisch eine Ansicht eines Lichtbandsystems;

Fig. 2

eine Querschnittdarstellung des Lichtbandsystems von Fig. 1;

Fig. 3

die Ausgestaltung der erfindungsgemäßen Leuchtenabdeckung in vergrößerter Darstellung

Fig. 4

die erfindungsgemäße Leuchtenabdeckung im aufgerollten Zustand;

Fig. 5 und 6

Ansichten eines weiteren Ausführungsbeispiels einer erfindungsgemäßen Leuchtenabdeckung und

Fig. 7

die Anordnung der Leuchtenabdeckung der Figuren 5 und 6 an einem Leuchtengehäuse.

The invention will be explained in more detail with reference to the accompanying drawings. Show it:

Fig. 1

schematically a view of a lighting system;

Fig. 2

a cross-sectional view of the lighting system of Fig. 1 ;

Fig. 3

the embodiment of the lamp cover according to the invention in an enlarged view

Fig. 4

the lamp cover according to the invention in the rolled-up state;

FIGS. 5 and 6

Views of a further embodiment of a lamp cover according to the invention and

Fig. 7

the arrangement of the lamp cover the FIGS. 5 and 6 on a luminaire housing.

FIG. 1 shows a typical application of a light strip in which the luminaire cover according to the invention is used. The light band provided with the reference numeral 1 is provided here as an installation variant and serves to illuminate an elongated space 100, for example, a passage over its entire length. Due to the ceiling installation, only the underside of the lighting system 1 is visible. Strictly speaking, only the elongated luminaire cover 20, through which light is emitted towards the bottom, is visible to a viewer. Depending on requirements, in this case the light cover 20 can influence the light when dispensing in a suitable manner, either to emit light in a very wide angular range or diffuse light or to emit light in specific directions. The prerequisite for this is that the material of the cover 20 has corresponding optical properties, which limits the possibilities for choosing a suitable material.

A basic structure of a lighting system 1 in sectional view is in FIG. 2 shown. Main component is an elongate housing 2, which is the recording of all serves important components. Schematically represented in the present case, only two light sources 3, which are located in the interior of the lamp housing 2. In addition, the elongated receiving space of the approximately U-shaped housing 2 also serves for the storage of suitable operating devices for operating the light sources 3 and the lines for the power supply. In the present case, fluorescent lamps 3 are shown as light sources, which are arranged behind one another over the entire length of the light band system 1 in order to emit light over the entire length. However, other light sources, in particular LEDs could be used. At the bottom of the housing 2 is then closed by the lamp cover 20, wherein the embodiment of this cover 20 and its attachment to the housing 2 will be explained in more detail below. For optical reasons, in this case, the arrangement of the cover 20 on the housing 2 takes place such that the cover 20 is flush with the underside of the ceiling 110 of the space 100. The assembly of the entire arrangement 1 takes place with the aid of mounting brackets 10, which are screwed on the one hand to the ceiling and on the other hand are coupled at its center leg 11 with the housing 2 of the light band 1.

The housing structure 2 of the light band 1 is usually formed from a plurality of interconnectable segments or units. As a result, it is possible to realize strip lights of virtually any length, with only a corresponding number of segments or units having to be joined together or arranged one behind the other. The modular design of the housing 2 does not have a negative effect on the appearance of the light band 1, since only a view of the viewer in the illustrated embodiment, the light cover 20 is visible.

For the lamp cover 20, however, the above does not apply, that is, a modular construction of the cover 20 over the entire length leads to a significant impairment of the appearance of the lighting system 1, since in particular when the activated state of the light sources 3, the joints between two adjacent Cover elements would be visible.

With the solution according to the invention, a luminaire cover is now provided, which can be realized almost endlessly, but in particular can be adapted in any way to the length of the lighting system 1. The light cover 20 is designed such that it can not only be made relatively simple but also can be transported without much effort to the site. At the same time, the cover, with regard to the materials used, satisfies the requirements with regard to the desired light output of a continuous row lighting system 1.

The inventive design of the lamp cover 20 is in FIG. 3 The cover 20 itself consists of two different components, on the one hand the elongated light exit element 21, via which the light output of the light band 1 takes place As can be seen, these fastening profiles 25 are used to attach the cover 20 to the housing 2. In this case, they have a U-shape, the middle leg 26 and the outer side leg 27 is provided in each case for locking or jamming with the lower profiled portion of the lamp housing 2. Strictly speaking, in this case the outer side leg 27 is clamped with a slight projection 7 of the housing 2 or a corresponding pull, where appropriate, the configuration of the housing 2 and the configuration of the mounting profiles 25 could also be chosen differently, as will be shown below with reference to a variant of the invention ,

According to the invention, it is provided that the two components - Lichtabstrahlelement 21 and mounting profile 25 - consist of different materials. In particular, a material is selected for the optically effective Lichtabstrahlelement 21, which is suitable for a corresponding effect on the light output. For this example, PMMA and PC come into question. Other materials would be conceivable, as long as they lead to a certain inherent stability of the Lichtabstrahlelements formed therefrom. At the same time the Lichtabstrahlelement 21 due to the plate shape limp, that is, it can be at least slightly bent in two dimensions, which - as explained in more detail below - is essential for the optimal transport properties of the lamp cover 20 of the invention.

By contrast, the material of the fastening profile 25 is significantly more flexible than the material for the light-emitting element 21, wherein a thermoplastic elastomer is preferably used. This increased flexibility in the fastening profiles 25 on the one hand has the advantage that a simpler fastening of the cover 20 to the housing 20 is made possible and at the same time - for the advantageous case that the fastening profiles 25 completely over the entire length of the lamp cover 20th an optimal seal between the housing 2 and the cover 20 is achieved, so that the ingress of dust or moisture is avoided at the interface. This makes it possible, with the aid of the cover according to the invention, to realize luminaire constructions of a so-called higher degree of protection,

Furthermore, the flexibility of the fastening profiles 20 allows them to be bent relatively easily despite the fact that they have a plurality of differently oriented legs, which in particular are also aligned perpendicular to the plane of the light exit element 21. The unit consisting of the hard component, that is, the light emitting element 21, as well as the soft component, so the fastening profiles 25, can therefore be rolled up, as in FIG. 4 is shown. Obviously, in this way, a luminaire cover of almost any length can be brought into a form in which it can be easily transported, in particular to the place of use, ie the mounting location of the lighting system 1 can be transported.

As the case of the representation of Fig. 4 can be removed, while the side surfaces of the roller are formed by the existing of the flexible material attachment profiles. These form in this case at the same time a protection of the light emission relevant Lichtabstrahlelements because on the one hand mechanical protection against external influences achieved and on the other hand, the penetration of dust or dirt is prevented in the interstices of the role. Furthermore, in the rolled-up state, the fastening profiles fulfill the function of spacers, by which the superimposition of the rolled-up layers of the light-emitting element is prevented, which additionally reduces the risk of damage during transport.

It should also be noted in this connection that the light-emitting element 21 does not necessarily have to be completely flat or flat, but that it must also have a certain profiling, e.g. may have a slight curvature or the like. It is only essential that the bending ability is not restricted too much by this profiling or shaping, so that the cover can still be rolled up in the sense of the present invention.

Ultimately, it is therefore provided that the lamp cover 20 is transported in the rolled-up state to the site and then optionally cut to the required length corresponding to the length of the lighting system 1, is cut off. In a simple manner, then the cover 20 can be attached to the underside of the lamp housing 2, so that over the entire length integrally extending cover is provided. It is particularly advantageous in this case if the fastening profiles 25 extend completely over the entire length, since an attachment of the cover 20 is achieved at each point of the housing. This is relevant insofar as after unrolling the cover 20, this may possibly still be slightly bent and with the help of the fastening profiles 25, the remaining tension is absorbed, so that the cover 20 as desired rests straight on the housing 2 and thus flush with the ceiling underside ,

During operation of the light band system 1, the cover 20 may easily contract or expand due to temperature variations as compared to the housing 2. Therefore, appropriate measures must be taken at the end portions of the lighting system to accommodate these variations in length and to avoid the emergence of the light output impairing columns or the like. Such gaps or disturbances in the light output are now no longer to be feared in the remaining region of the light band due to the integral nature of the cover.

A production of the lamp cover 20 according to the invention is preferably carried out in the so-called co-extrusion process. As a result, the cover can first be produced in almost endless length.

In a development of the invention, it can further be provided that the light exit element-both at its light exit side and at the opposite light entry side-has a certain structuring by which the light output is influenced in a certain desired manner. For example, in the context of the above-mentioned extrusion process, elongated structures such as e.g. elongated prisms or grooves are introduced into the surface of the light exit element. If, if necessary, transverse structures are also to be realized, it would be possible, for example, to form them by means of a foil which is applied to the light exit element, e.g. is glued.

The FIGS. 5 and 6 show as a further embodiment, a corresponding lamp cover 20, in which the lamp housing facing surface of the light exit element 21 is provided with a corresponding structure 30. This indicated structure 30 consists in the case shown of mutually crossed structural elements. Since such a structure is difficult to realize in the context of an extrusion process, therefore, in the case shown, the structure is preferably formed by a film which has been taped onto the corresponding side of the light exit element 21. Again, however, the luminaire cover 20 according to the invention can be compared to the overall in FIG. 4 be shown wound role.

In this second embodiment, the lateral attachment profiles 25 are designed somewhat differently and now have approximately a V-shape in cross section. On the one hand, this shape also allows the light cover 20 to be rolled up and, on the other hand, makes it possible to fasten it to a luminaire housing, such as FIG. 7 shows. On both sides of the cover in this case narrower shadow gaps 5 are formed, as in the embodiment of the FIGS. 1 to 4 the case is.

The cross-sectional view of FIG. 6 shows a particularly advantageous embodiment of the light exit element 21 and the fastening profiles 25 in the connection area. The fact that one of the two components - here the fastening profiles 25 - has a web with 28 undercuts, which is enclosed by the other components, a special good connection achieved by a permanent cohesion despite the different materials is guaranteed. Of course, this embodiment could also in the embodiment of FIGS. 1 to 4 be provided.

Ultimately, therefore, a luminaire cover is provided with the invention, which can be easily adapted to any length of a lighting system. Due to the choice of material according to the invention here also the transport of the cover at its place of use no longer represents a problem. At the same time, however, it is ensured that materials are used for the optically relevant components which satisfy the corresponding requirements. The use of the cover according to the invention is not limited to installation variants. Of course, it can also be used for mounting variants or suspended light strips.

Claims (10)

1. Light cover (20) for an elongate lighting assembly (1) comprising a substantially plate-shaped, elongate light emitting element (21) as well as mounting sections (25) which are provided for mounting the light cover (20) on a lamp housing (2) and are disposed on the long sides of the light emitting element (21),
   characterised in that
   the light emitting element (21) and the mounting sections (25) are made of different materials and the material of the mounting sections (25) is more flexible than the material of the light emitting element (21), and wherein the light cover (20) is formed in one piece.
2. Light cover according to Claim 1,
   characterised in that
   the mounting sections (25) extend along the entire length of the light emitting element (21).
3. Light cover according to Claim 1 or 2,
   characterised in that
   the mounting sections (25) respectively form one or more crosspieces which are at least partially aligned substantially perpendicular to the plane of the light emitting element (21).
4. Light cover according to any one of the preceding Claims,
   characterised in that
   the light emitting element (21) is made of PMMA or PC.
5. Light cover according to any one of the preceding Claims,
   characterised in that
   the mounting sections (25) are made of a thermoplastic elastomer.
6. Light cover according to any one of the preceding Claims,
   characterised in that
   the light emitting element (21) possesses light-scattering properties.
7. Light cover according to any one of the preceding Claims,
   characterised in that
   said light cover was produced using a co-extrusion process.
8. Light cover according to any one of the preceding Claims,
   characterised in that
   at least one surface of the light emitting element (21) is provided with a structure.
9. Light cover according to Claim 8,
   characterised in that
   the structure is formed by a film which is preferably glued onto the light emitting element (21).
10. Light strip system having an elongate housing (2) with light sources (3) contained therein and a cover according to any one of the preceding Claims.

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