EP3577391B1 - Tool-less installation system for an led assembly in a lamp with a higher index of protection - Google Patents

Description

The present invention relates to a lamp in which an LED assembly is mounted, and more particularly to the mounting system of the LED assembly in the lamp housing.

Since in LEDs ("light emitting diodes", by which all forms of semiconductor light sources, including organic semiconductor light sources are generally understood), part of the electrical energy is always converted into heat and the heat is generated at a relatively small, almost punctiform location a good thermal connection of the LEDs is necessary for their cooling. The LEDs are usually placed on a circuit board that is in the best possible thermal contact with components in the luminaire, e.g. heat sinks or a solid metal housing, in order to dissipate the heat. In order to establish a good thermal contact, it is customary in the prior art to screw the LED assembly firmly into the housing or to attach it with other fastening elements. A large number of fastening elements are distributed over the LED assembly in order to ensure good thermal contact with the lamp housing or a heat sink. In the case of screws, the torque must be adhered to precisely in order to secure the connection, but also not to overload it. This type of fastening always requires tools and must be carried out very carefully.

The DE 20 2015 100 151 U1 discloses a lighting device according to the preamble of claim 1. Further constructions of lighting units with in a housing component held LED light units are in the DE 10 2010 023 497 A1 and the DE 20 2011 051 094 U1 described. In these publications, the holding elements for the LED light units are short compared to the overall extent of the LED light units.

The object of the present invention is to provide a light with an LED assembly in which the LED assembly can be mounted without tools and which is optimized with regard to the thermal properties of the LED assembly.

The object is achieved by a lamp according to claim 1.

A special feature of the present invention is the support element, which spans the LED assembly with a web and holds the LED assembly in the housing with several spring elements. This has several advantages over rigid fastening with screws or comparable fastening means. The spring elements directly or indirectly press the LED assembly against the housing, so that there is a uniform contact pressure over the rear surface of the LED assembly against the housing. In this way a good thermal contact is achieved. Furthermore, the springs ensure a uniform force over the entire LED assembly, since several spring elements hold the LED assembly in the housing. In spite of this, the LED assembly can be installed very easily, since all spring elements are arranged on a common web of the support element and this only needs to be attached to the housing at two support points. Assembly is therefore simpler compared to a large number of fasteners. Furthermore, the torques of the screws customary in the prior art do not need to be observed and assembly can be carried out without tools because the contact pressure is only given by the properties of the spring elements. In addition, larger construction tolerances are acceptable if only spring elements act on the LED assembly. The exact placement of the spring elements in relation to the LED assembly is not critical compared to a screw connection, in which the holes have to be exactly aligned. Another advantage is that there is no rigid connection between the LED assembly and the housing. If the LED assembly has a different coefficient of thermal expansion than the housing, the components can expand differently. With a rigid connection this can lead to tension and material damage. When fastening the LED assembly by only the spring elements, on the other hand, the LED assembly can expand differently with respect to the housing without material damage occurring. Furthermore, a constant contact pressure is maintained even if the materials of the LED assembly or the housing change in volume due to aging, as is often the case with plastics in particular.

According to a preferred embodiment, the LED assembly lies flat on the luminaire housing on the side opposite the support element. The thermal contact is further improved by the flat contact. In this area, means for improving the heat transfer, e.g. a thermally conductive film or a thermally conductive paste, can be introduced in order to further improve the thermal contact between the housing, which acts as a heat sink, and the LED assembly.

According to a preferred embodiment, the support points are provided at opposite ends of the web. As a result, the support element can be supported on housing parts outside the LED assembly and nevertheless span the entire LED assembly. Because of the support points at the ends of the web, it is not necessary for a contact to be made with the housing within the LED assembly to fix the support element. In contrast, conventional fastening means such as screws must also be provided at a large number of locations through holes within the LED assembly.

According to a preferred embodiment, one of the support points is formed by an elastic latching element. The elastic latching element has a run-on bevel and an edge that is set back from the run-on bevel, so that the latching element when the support element is inserted into the luminaire housing is deflected in a resilient manner by a force acting on the run-up bevel until it springs back via a recess in the housing, so that the edge of the latching element hooks onto the recess in the luminaire housing. Such a latching connection is particularly suitable as a support point, since it can be actuated without tools. According to a further development, provision can also be made for the latching element to be accessible without tools in the assembled state in order to detach it again from the lamp housing. In particular, there can be an opening in the lamp housing into which the latching element engages in a resilient manner. The opening can be accessible from the outside, so that the latching element can be pushed back by hand against the resilient effect in order to dismantle the support element again.

According to a preferred embodiment, one of the support points is formed by a hook which is suspended from the lamp housing, and the support element can be pivoted into the lamp housing with the hook suspended. This support point is preferably provided at an end of the web opposite the second support point with the locking element. To assemble the support element, it is hung with the hook on one side, swiveled over the LED component and latched onto the housing on the opposite side with the latching element. As a result, the support element can be attached to the luminaire housing in a simple manner without tools. This assembly is easy to carry out even at the installation site of the luminaire.

According to a preferred embodiment, the plurality of spring elements have at least three spring elements which each act with an elastic force directly or indirectly on the LED assembly. Three or more spring elements are preferred because they distribute the force to hold the LED assembly evenly across the assembly. According to a further development it is provided that the several spring elements are designed with a higher spring constant towards the center of the web, in particular are provided with longer and / or more rigid spring legs than the spring elements located at the ends of the web. This compensates for the effect of the web flexing in order to enable the LED assembly to be pressed evenly into the housing. In the middle area of the bar, when it is supported at the two opposite ends, it will bend slightly so that the distance to the LED assembly increases. Due to the further formed spring elements, e.g. longer spring legs or spring legs with a higher bending force, despite the greater distance to the LED group due to the deflection of the web, the same contact pressure is achieved as on the edges of the web, on which the spring elements are closer to the LED Assembly.

According to a preferred embodiment, the LED assembly has a cover, for example a photometric cover, which encapsulates the LEDs in the LED assembly so that it is impervious to moisture and dust. Furthermore, the LED assembly is plugged into the luminaire housing with a self-retaining seal. For example, a circumferential seal can be inserted along a groove in the cover, which seal is inserted into a circumferential groove in the luminaire housing on the side opposite the LED assembly. This allows the LED assembly to be mounted on the housing in a moisture-proof and dust-proof manner. However, the seal has another advantage because it also helps support the LED assembly in the housing. As a result, the spring force which the spring elements of the support element exert on the LED assembly can be made smaller. In this embodiment, the LED assembly is jointly protected against falling down by the seal and the support element in the housing. According to a further development, the seal in a cross section perpendicular to its longitudinal extension on lateral lamellas, which are arranged at an obtuse angle with respect to an insertion direction of the seal into a groove of the lamp housing and / or a groove of the LED assembly in order to move away from the insertion direction from the groove in the lamp housing and / or oppose LED assembly. The lamellas not only improve the tightness, but also act like a barb. As a result, the seal can accommodate a higher load-bearing capacity for the LED assembly.

According to a preferred embodiment, the support element is guided centrally over the LED assembly and the spring elements are preferably arranged at positions which, in terms of lighting technology, are of no significance for the emission of the LED assembly. The arrangement of the support element in the middle of the LED assembly has the advantage that the LED assembly can be held on the luminaire housing evenly over the entire length. In this embodiment, however, the web of the support element can be made narrow and the spring elements can only be attached at positions where the LED assembly does not emit light, e.g. between reflectors or lenses that are assigned to the LEDs. As a result, the support element does not have a negative effect on the light emission of the luminaire, although the support element nevertheless grips over the LED assembly in order to press the LED assembly evenly against the luminaire housing.

According to a preferred embodiment, the support element is set up to accommodate further components apart from the LED assembly on the side facing away from the LED assembly. For example, the further components can comprise an optical attachment (lenses or reflectors) and / or lamellae and / or a grid for protection against mechanical effects. The other components can be used to mechanically protect the luminaire, for example against vandalism. The additional Components can also perform technical lighting functions, for example to influence the light distribution for a particular lighting task or to improve the glare control of the luminaire. It is advantageous here that the other components can be attached directly to the support element, for example by means of a plug connection. As a result, the components are arranged directly in front of the LED assembly, ie in the area of the light outlet opening of the lamp. Since the springs can be supported on the stable housing via the LED assembly, higher external forces can also be transmitted via the springs. As a result, it is easily possible to mount a grid on the luminaire as vandal protection in this way. For the lighting elements, it is advantageous that the position of the support element with respect to the LED assembly is defined so that the lighting elements can be aligned with the positions of the LEDs or the surfaces radiating from the LED assembly.

Figur 1

zeigt eine perspektivische Aufsicht auf eine Leuchte im Bereich der Lichtaustrittsfläche des Gehäuses.

Figur 2

zeigt eine Seitenansicht eines Abstützelements als einzelnes Bauteil für die Leuchte nach der Figur 1.

Figur 3

zeigt einen Längsquerschnitt durch die Leuchte nach Figur 1.

Figur 4

zeigt einen Querschnitt durch die Leuchte senkrecht zum Querschnitt nach Figur 3.

Figur 5

zeigt einen Querschnitt durch die Leuchte entsprechend der Figur 4 mit einem Zusatzanbauteil im Bereich der Lichtaustrittsöffnung.

Further features and advantages of the present invention will become clear from the following description of a preferred embodiment, which is given in conjunction with the accompanying figures. The figures show the following:

Figure 1

shows a perspective top view of a lamp in the area of the light exit surface of the housing.

Figure 2

shows a side view of a support element as a single component for the lamp according to FIG Figure 1 .

Figure 3

shows a longitudinal cross-section through the lamp Figure 1 .

Figure 4

shows a cross section through the lamp perpendicular to the cross section Figure 3 .

Figure 5

shows a cross section through the lamp according to FIG Figure 4 with an additional attachment in the area of the light exit opening.

The lamp according to the embodiment shown can in particular be designed as an outdoor lamp. A solid housing 2 forms a downwardly open receiving space for an LED assembly 4. The LED assembly 4 comprises a plurality of LEDs, each of which is assigned a reflector in the assembly.

The fastening of the LED assembly 4 in the lamp housing 2 is described below.

The LED assembly 4 is inserted into the opening of the lamp housing 2. A support element 6, which is shown as a single component in Figure 2 is hung with a hook at one end of a continuous web in the housing and pivoted into the housing, so that the support element 6 with a continuous web 10 engages over the LED assembly 4. At the end of the web 10 opposite the hook 8, a latching element 12 is provided. The latching element 12 has a run-on bevel which deflects the latching element 12 elastically inward when it strikes a housing edge and is pressed further in the direction of the housing 2. The latching element 12 springs back with one edge over a recess in the housing 2 and hooks in this way in the housing 2. As in FIG Figure 1 shown, an opening 16 is formed on the front side of the housing, which allows access to the latching element 12 directly from the outside. As a result, the latching element 12 can also be released again from the outside and the support element 6 can be dismantled in the reverse order.

The support element 6 has several spring elements 14 along the web 10, which extend in the direction of the LED assembly 4. Each of the spring elements 14 engages, as in FIG Figure 3 shown, at a defined point of the LED assembly 4 and thereby presses the LED assembly against the housing 2. The LED assembly 4 is thereby mechanically held in the housing 2 without a rigid connection between the housing 2 and the LED Assembly 4 is necessary. This has the advantage that the LED assembly can expand thermally independently of the housing or can change due to material aging without mechanical stresses occurring in the LED assembly. The housing 2 is preferably formed from a material with good thermal conductivity, for example aluminum. In contrast, the LED assembly 4 is predominantly made of plastic. Because of the different expansion coefficients, stresses would arise when the LED assembly 4 is screwed to the housing 2. Since the LED assembly 4 is only held by the spring elements 14, however, it can move along the contact surface on the housing 2 for thermal expansion.

The length of the web 10 in connection with the support points, which are only given at the outer ends by the hook 8 and the locking element 12, can lead to the web 10 bending. With identical spring elements 14 in each case, this would have the effect that the contact pressure in the center of the LED assembly 4 is lower than at the outer edges. This effect can be compensated for in that the spring elements 14 are designed with higher spring constants toward the center of the web, for example with longer spring legs or with a stronger bending stress. As a result, the spring elements 14 in the central area of the web would achieve a higher contact pressure with the same distance from the LED assembly 4. However, since the distance increases due to the bending of the web 10, the effects are offset against each other so that a uniform elastic force is exerted on the LED assembly 4 by each spring element along the web.

In the Figures 3 and 4th a seal 18 is also shown, which is introduced between the LED assembly 4 and the lamp housing 2. The seal 18 engages in a circumferential groove on the side of the housing 2 and in an opposite circumferential groove on the side of the LED module 4, which groove is formed on a transparent cover 5 of the LED module 4. The seal 18 also has a plurality of lamellae which, in the manner of a barb, have an obtuse angle with respect to the direction of insertion into the respective groove. As a result, the lamellae get caught and resist pulling off the seal 18 against the insertion directions. The seal 18 has two functions. On the one hand, it seals the LED assembly 4 along the circumference of the cover 5 from the housing 2. Furthermore, the seal 18, in particular the seal 18 with the previously described lamellae acting as barbs, leads to a mechanical connection between the LED assembly 4 and the housing 2. The LED assembly 4 is already held in the housing 2 by the seal 18 alone . In this embodiment, the support element 6 serves only as a further mechanical fastening of the LED assembly 4, which forces only need to apply in addition to the mechanical hold that is already provided by the seal 18.

In the cross-sections according to Figure 3 it can be seen that the spring elements 14 only act between positions of the LED assembly 4 at which reflectors emit light. As a result, the spring elements 14 or the web 10 do not affect the light output of the lamp.

However, it is preferred that the spring elements 14 act at locations on the LED assembly at which massive support points are present. This protects the optically sensitive parts of the LED assembly 4 from damage.

Referring to the Figure 5 a variant of the lamp is shown. The luminaire has the same elements as described above. In addition, a grille 20 is arranged in the area of the light exit surface of the lamp. The grid 20 is fixed to the support element 6 by fastening elements 12. As a result, the spring elements 14 of the support element can absorb loads which act on the grid 20 from the outside. It is also possible to attach other light-conducting elements instead of or in addition to the grating 20. For example, an optical attachment with light-refracting or light-reflecting means can be attached to the support element 6. The further component is fastened with fastening elements 22 in the form of plug connections in recesses of the support element 6 on the side facing away from the LED assembly.

The support element 6, as described above, can simultaneously take on other functions. Since the support element 6 is in any case preferably formed from metal, it can take on the task of an antenna. In this embodiment, the support element is connected to a control element in the housing 2 or the LED assembly 4. The antenna allows control signals to be received and transmitted to the control device in the luminaire.

Numerous modifications can be made to the embodiments of the invention described above without departing from the invention, which is defined by the claims. For example, more than just one support element can be provided for larger LED assemblies. For example two or three support elements can be arranged in parallel. Support elements can also be provided crosswise. It is also possible for the lamp to have several separate LED assemblies, each of which is held by a support element or by a plurality of support elements.

REFERENCE LIST

2

casing

4th

LED assembly

5

cover

6th

Support element

8th

hook

10

web

12

Locking element

14th

Spring element

16

Opening in the housing

18th

poetry

20th

Grid

22nd

Fastening element of the grid

Claims (14)

1. A luminaire with a luminaire housing (2), in which an LED assembly (4) is mounted wherein the LED assembly (4) is held in the luminaire housing (2) by means of a support element (6),
   wherein the support element (6) spans the LED assembly (4) and is supported on the luminaire housing (2),
   and the support element (6) has, on a side facing the LED assembly (4), a plurality of spring elements (14) which apply an elastic force which acts directly or indirectly on the LED assembly (4) in order to hold it in the luminaire housing (2), characterized in that in that the support element (6) spans the LED assembly (4) with a web (10) and is supported on the luminaire housing (2) with at least two support points, the plurality of spring elements (14) being provided on the web (10) of the support element (6) on the side facing the LED assembly (4).
2. The luminaire according to claim 1, wherein the LED assembly (4) lies flat against the luminaire housing (2) on the side opposite the support element (6).
3. The luminaire according to one of the preceding claims, wherein the two support points are provided at opposite ends of the web (10).
4. The luminaire according to one of the preceding claims, wherein one of the support points is formed by an elastic latching element (12) which has a run-up slope and an edge which is set back from the run-up slope, so that when the supporting element (6) is engaged in the luminaire housing (2), the latching element (12) is deflected resiliently by a force acting on the run-up slope until it springs back via a recess in the luminaire housing (2), so that the edge of the latching element (12) hooks into the recess of the luminaire housing.
5. The luminaire according to claim 4, wherein the latching element (12) is accessible without tools in the mounted state, in particular can be manually operated through an opening (16) in the luminaire housing (2) in order to release the latching element (12) from the luminaire housing (2).
6. The luminaire according to one of the preceding claims, whereby one of the support points is formed by a hook (8) which can be hooked into the luminaire housing, and the support element (6) with hooked-in hook (8) can be pivoted into the luminaire housing.
7. The luminaire according to one of the preceding claims, wherein the plurality of spring elements (14) comprises at least three spring elements (14), which each act directly or indirectly on the LED assembly (4) with an elastic force.
8. The luminaire according to claim 7, the plurality of spring elements (14) being designed with a higher spring constant towards the center of the web (10), in particular being provided with longer and/or more flexurally rigid spring legs than the spring elements (14) located at the ends of the web (10).
9. The luminaire according to one of the preceding claims, the LED assembly (4) having a cover (5), and the LED assembly (4) being plugged into the luminaire housing with a self-retaining seal (18).
10. The luminaire according to claim 9, wherein the seal (18) in a cross section perpendicular to the longitudinal extension have lateral lamellae which are arranged at an obtuse angle with respect to a direction of insertion of the seal (18) into a groove of the luminaire housing (2) and/or a groove of the LED assembly (4) in order to resist being pushed out of the groove in the luminaire housing (2) and/or the LED assembly (4) against the direction of insertion.
11. The luminaire according to one of the preceding claims, wherein the support element (6) is guided centrally over the LED assembly (4) and the spring elements (14) are preferably arranged in positions which are without significance for the radiation of the LED assembly (4) in terms of lighting technology.
12. The luminaire according to one of the preceding claims, wherein the support element (6) is adapted to receive further components apart from the LED assembly on the side facing away from the LED assembly.
13. The luminaire according to claim 12, wherein the further components comprise an attachment optic and/or louvres and/or a grid (20) for protection against mechanical effects.
14. The luminaire according to one of the preceding claims, wherein metal elements of the supporting element are arranged as an antenna and the antenna is connected to a control unit of the luminaire in the luminaire housing (2) or LED assembly (4).

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