HK1097035B - Light - Google Patents

Description

Lighting device

Technical Field

The present invention relates to a lighting device.

Background

In general, lighting devices with gas discharge lamps are particularly economical light sources which can be operated with a long life and a high luminous efficiency with respect to the consumed electrical power. Such lamps are widely used, in particular, in the industrial and commercial sector and in the subsidiary rooms of homes, where a certain lack of spectral distribution and, in particular, constraints on the shaping of decorative luminaires, brought about by the length and shape of the lamp, are not as important as, for example, in residential areas. Lighting fixtures in industrial and commercial areas, in basements or in vehicle interiors also often require the least waterproof construction and are often highly developed and cost effective mass products. Known lighting devices of this type have a lamp envelope which consists of a highly transparent upper part and an opaque lower part. In the case of such a distribution, the opaque lower part can be formed by an artificial resin housing which withstands the heat emitted by the lamp, in particular in the region of the terminal electrodes, in particular of the ballast (choke coil) arranged in the lighting device, while the upper part is made of a highly transparent thermoplastic material which achieves the desired light radiation distribution, but has a much lower heat resistance and a much greater thermal expansion than the thermosetting lower part material.

The terms "upper part" and "lower part" which are used in practice and are used here do not relate to the installation orientation at the time, but rather the lower part denotes a housing which is fixed to a wall or ceiling and which usually also fixes an electrical device, and the "upper part" denotes a cover which is detachably fixed to the lower part. Thus, for example, when mounted on a ceiling, the upper member may be lowermost.

However, the lower part, which is usually more robust to thermal and mechanical loads, consisting of an opaque thermosetting material, absorbs a significant portion of the light emitted by the lamp or lamps within the housing. Furthermore, if a large shadow region appears on the lower component side, the light distribution is unsatisfactory. When mounted on a ceiling or wall, dark shadow regions with an undesirable illumination image are created on the area adjacent to the lamp.

Furthermore, attempts have been made to produce such a dish-shaped lamp with a transparent lower part from the same or similar material as the upper part. It has been shown in practice, however, that fluctuations in the material properties lead to mounting and sealing problems which cannot be solved anyway with commercially acceptable costs.

Disclosure of Invention

It is therefore the object of the present invention to create a lighting device of the type to which the invention is directed, which allows better light emission and light distribution without the standards for improvement of such lamps having to pay a price in terms of their reliability, robustness, ease of installation and operation and in particular economical manufacture.

In the case of the lighting device according to the invention for mounting at least one elongate gas discharge lamp, the lighting device has a housing which is formed in a closed manner from a transparent lower part and a transparent upper part, in which the lower part and the upper part are made from the same material batch of thermoplastic material and overlap one another along edges which are surrounded on both sides. According to the invention, one edge is designed as a plug-in edge, and the other edge is designed as a first or third recess for this plug-in edge, which plug-in edge is provided in cross section with an open hollow profile. A better light distribution and light emission is achieved in that the lower part is likewise made of a light-transmitting or highly transparent material. That is to say the light distribution is not obstructed by the lower part, but is also largely open. Thus, dark areas bordering such lamps can be avoided even when mounted on walls or ceilings, and the luminous flux impinging on the walls or ceilings can be reflected to the room for use when they are light-colored.

However, the particular thermal sensitivity of transparent thermoplastics requires particular precautions against deformation. In particular, it is ensured that the tightness of the casing with respect to water resistance is not lost with heating of the material and large expansions caused by temperature, without causing expensive, complex and difficult to master structures by manufacturing.

In this connection it has been concluded that the lower part is made of the same thermoplastic material as the upper part. This specification is however not satisfied by the following measures: i.e. the material has the same name in both cases. Nominally consistent materials of the same manufacturer or even different lots (charges) of the same manufacturer may produce inadequate consistency. Even more preferably, the starting materials are not only intended for the same batch and its homogeneity, but are also to be produced in a consistent manner with respect to the starting materials and processing conditions. It is therefore expedient to provide that the upper part and the lower part are injection-molded by the same injection-molding machine in a common injection molding process, or even to design only one common injection mold with a cavity for the lower part and a cavity for the upper part, the injection channels of which are substantially symmetrical or identical in length.

With such finely matched identical materials, a uniform deformation without displacement is obtained even with large thermal expansions, which avoids gaps and corresponding leaktightness between the upper and lower parts.

Drawings

Further embodiments of the invention are disclosed by the claims. These solutions and their advantages are explained in the following description of an embodiment. In the drawings, there is shown:

fig. 1 is a cross-sectional view of a lighting device;

FIG. 2 is a partial longitudinal section taken along line II-II in FIG. 1;

figure 3 is a cross-sectional view of a variant of the lighting device.

Detailed Description

The lighting device, which is designated in general by 1, has a housing, designated in general by 4, which is composed of an upper part 2 and a lower part 3, which, in cooperation with an internally located gas discharge lamp 5 in the form of an elongated tube, extends in an elongated manner, for example, in the direction of view of fig. 1, and is closed at the end in a cap-like manner. The upper part 2 consists in a known manner of a transparent thermoplastic, for example acrylic glass (PMMA) or transparent polycarbonate. The lower part 3 consists of the same material in a novel manner, wherein the consistency is achieved not only with regard to the base material and its additives and, if necessary, the source, but also with regard to the supply lot (Liefercharge), the storage and temperature conditions and the processing, in particular the extrusion.

This conformity is suitably produced in that the thermoplastic material is injected simultaneously into the injection mould or cavity for the upper part 2 and into the injection mould or cavity for the lower part 3 in a common injection process. The equalization is also promoted in that the single injection mold contains both a cavity for the upper part 2 and a cavity for the lower part 3, wherein the injection path and the injection channel are equalized with each other. The basic design of such an injection mold of the complementary casing part, which is almost twinned, can of course also be multiplied, in which case a plurality of upper and lower parts can be simultaneously injected in one mold, although the multiplication is practically limited by the size of the injection mold and the clamping force which is to be provided in this case. The elongated and thus already quite large housing part allows in the current art a pairing of the upper part and the lower part.

In any case, an injection molding process is thus obtained in which the injection molding machine injects a uniform material with injection properties through its injection opening into the mold, in which the material is substantially symmetrical and distributed in the injection mold at a uniform temperature into cavities lying alongside one another.

A special aim of such shaping and processing solutions is to balance the housing as much as possible between the upper part and the lower part with regard to its temperature behavior and in particular with regard to its thermal expansion. The housing 4 is subjected to thermal stress from the outside by the changing temperature of the surrounding air, sometimes by solar radiation or rain, but in particular by the heating of the gas discharge lamp 5, which is primarily in the region of the end electrode, and also of the ballast, which should also be covered and protected by the housing 4 and only ideally has a loss-free choke effect (induction coil), but also electrical losses occur due to the structural dimensions and the production costs, which can lead to temperatures of more than 200 ℃.

The usual housing for gas discharge lamps is provided with a lower part made of a heat-resistant thermosetting plastic, which is subjected to thermal stresses with high heat resistance and low thermal expansion, whereas the thermoplastic transparent plastic used according to the invention is much more sensitive. That is, the solution of this problem here is not to firm lower parts, but to the balance of the upper and lower parts so that they are coordinated with one another so as not to subject the housing to excessive stresses and deflections, when the thermal expansion cannot be kept small due to material reasons.

The housing therefore also has a transparent lower part 3, so that the light emitted by the gas discharge lamp 5 emerges from this region, avoiding shadows around the lower part 3 and additionally sending light into the room by reflection when mounted on a wall or ceiling, the housing also advantageously appearing bright as a whole.

Of course, instead of using a single gas discharge lamp 5, it is also possible to provide two or more gas discharge lamps in one housing, without other problems arising in this respect.

In view of the above-identified thermal load, in particular of the housing, the connection region between the upper part 2 and the lower part 3 is critical, both with regard to the simple processing as a prerequisite for such mass-produced products with a high price competitiveness and with regard to uncomplicated handling by the installer or purchaser. A snap connection 37 is thus provided for the connection of the upper part and the lower part, wherein a sealing groove 8 is formed on one side, i.e. in this case on the lower part 3. The sealing groove opens in the transverse direction with respect to the closing movement of the upper part 2 towards the lower part 3 and overlaps the plug-in edge 9 of the upper part, which itself has an outwardly projecting annular flange 10 which is matched to the annular groove. The annular collar further improves the water resistance of the typical snap-in connection by the fact that the plug-in edge 9 (of the upper part 2) engages in a first recess 11, which is annular on the edge side and has a U-shaped cross section, for the plug-in edge 9 and surrounds and covers the plug-in edge 9. The mechanical strain of the housing 4, for example during water testing, in particular in combination with the thermal loading of the housing, does not lead to the upper part 2 and the lower part 3 cracking which is dangerous in terms of splash protection.

The annular flange 10 formed together with the injection molding of the upper part 2 is the simplest and most economical snap-fit. Of course, the plug-in edge 9 can also be provided in cross section with a sealing groove which corresponds to the sealing groove 8 and is opposite it, so that a central cavity of circular cross section is provided, into which an elastic annular seal can be inserted. This design is used in particular when the material is too strong or too rigid for establishing the snap-lock connection.

In fig. 1, the handling projections (griffahne) 12, 13 which are formed integrally with the upper part 2 and the lower part 3 can be seen on both sides of the connecting region between the upper part 2 and the lower part 3. They are offset from one another in the viewing direction, i.e. in the longitudinal direction of the housing 4, by exactly such a distance that they do not overlap one another. They make it possible to remove the housing part from the latching position with the fingers, i.e. without tools.

It can also be seen in fig. 1 that the ballast 6 is shielded with respect to the lower part 3 by a shielding element 14. This is a U-shaped bent sheet whose underside is fastened between the ballast 6 and a base projection formed in the lower region of the lower part 3, but extends laterally at a distance from the ballast 6 and upwards approximately to the height of the ballast in order to intercept as well as possible the heat radiation and convection to the lower part 3.

In the longitudinal section according to fig. 2, only a small part of the entire length of the lighting device is shown in detail, wherein in particular the ballast 6 with a projecting base 15 for mounting purposes and the shielding element 14, which likewise projects in the longitudinal direction from the ballast 6, can be seen. Both of which are fixed for transport, for example by screws 16, on a base area 17 of the lower part 3 during preassembly.

This base region 17 has a vertical through-opening 18 which opens upwards into a projection 19 which passes through a first mounting opening 20 of the ballast 6 or the base 15 and a second mounting opening 21 of the shielding element 14 in an insulating manner. An insulating pad 22 and an annular pad 23, in particular of metal, are provided, which serve to: when the lighting device 1 is mounted on a wall or ceiling, it is screwed out by means of screws or similar fastening elements, so that the lighting device is fastened to a substrate. Thus, the ballast is fixed in a short path with respect to the base on one side of the building as a critical element which is particularly heavy and heat generating. The insulating pad 22, which is made in the shape of a cup, allows the fixing element to be pressed against the bottom 15 of the ballast, regardless of the amount of protrusion of the boss 19.

The sealing of the mounting opening, which is generally to be considered, is effected in principle within the region of the through-opening 18 or the insulating mat 22. In this case, a second recess 24 is provided in the bottom surface, and thus on the outside, in a bottom region 25 of the lower part 3, into which a sealing ring 26 is inserted.

A modified embodiment of the lighting device according to fig. 3 is indicated in general at 31 and likewise has a housing 34 made up of an upper part 32 and a lower part 33, wherein a significant difference from the above-described lighting device 1 is that to realize the latching connection 37, a plug-in edge 39 is provided which is configured in cross section as a U-shaped profile. This plug-in edge, like the plug-in edge 9 in the luminaire 1, is inserted into a U-shaped third recess 41 on the edge of the lower part 33 facing the upper part 32 during the closing movement between the upper part 32 and the lower part 33 and is latched there with a suitable annular collar 40 in a lateral sealing groove 38. The shaping of the plug-in edge 39 as an open hollow profile results in a transverse elasticity, so that the annular collar 40 is elastically pressed into the annular groove 38 without this pressing force impeding the insertion and separation of the upper part 32 and the lower part 33 from one another. In the sense of the pressing force specified here, a pretensioning force can be provided structurally by configuring the plug-in edge 39 in the region of the annular collar 40 to be wider than the third recess 41 in the region of the sealing groove 38. In the plugged-in state of the upper part 32 and the lower part 33, the plug-in edge 39 is thus elastically pressed together to a certain extent and/or the third recess 41 is elastically relieved in cross section. This improves the sealing fit in the latching region.

It is also advantageous to provide a channel-like free intermediate space 42 between the plug-in edge 39 and the third recess 41. That is to say, the third recess 41 does not enclose the plug-in edge 39 tightly in cross section, but leaves a free cavity. This intermediate cavity 42 proves to be a closed cavity during the filling test, and small amounts of water which may enter the sealing region between the annular collar 40 and the sealing groove 38 from the outside at high injection water pressures are kept out of the housing interior. Here, the sufficiently sealed surface fit between the protruding portions where the housing upper member 32 and the housing lower member 33 overlap each other prevents water from entering the inside of the lighting device housing 34 from the intermediate cavity 42. On the other hand, the plug connection between the upper part 32 and the lower part 33 should not be hermetically sealed, so that small moisture influences reach the environment by diffusion movements and equilibrium movements in the event of heat and pressure fluctuations.

The tight fit between the plug-in edge 39 and the third recess 41 with an outer intermediate slot 43 running in a curved manner in cross section is advantageous for the rigidity and the tightness of the latching connection 37. It prevents splashing water from penetrating the sealing region between the sealing groove 38 and the annular collar 40 even in the case of strong water jets and covers this region with an end collar 44, which at the same time contributes to the rigidity of the plug-in edge profile in the longitudinal direction (shape stability).

Claims (17)

1. Lighting device (1, 31) for mounting at least one elongate gas discharge lamp (5), having a housing (4, 34) which is formed in a closed manner from a transparent lower part (3, 33) and a transparent upper part (2, 32) for fixing electrical equipment, wherein the lower part (3, 33) and the upper part (2, 32) are made from the same batch of thermoplastic plastic material and overlap one another along edges which are surrounded on both sides, characterized in that: one edge is designed as a plug-in edge (9, 39), and the other edge is designed as a first recess (11) or a third recess (41) for this plug-in edge (9, 39), which is provided with an open hollow profile in cross section.

2. The lighting apparatus of claim 1, wherein: the upper part (2, 32) and the lower part (3, 33) are produced as injection-molded parts in one injection-molding process.

3. The lighting device of claim 2, wherein: the upper part (2, 32) and the lower part (3, 33) are injection-molded in a common mold which is designed symmetrically to the injection-molding process.

4. A lighting device as claimed in any one of claims 1 to 3, characterized in that: at least one of the upper (2, 32) and lower (3, 33) parts is provided with a sealing groove (8, 38).

5. The lighting apparatus of claim 4 wherein: the lower part (3, 33) or the upper part (2, 32) without the sealing groove (8, 38) is formed with a sealing collar (10, 40) which engages in a form-fitting manner in the sealing groove.

6. The lighting apparatus of claim 4 wherein: the lower part (3, 33) and the upper part (2, 32) are provided with a sealing groove for mounting a common annular seal.

7. The lighting apparatus of claim 1, wherein: the first and third recesses are U-shaped and provided with sealing grooves (8, 38) on an outer U-arm.

8. The lighting apparatus of claim 7 wherein: the plug-in edge (39) and the third recess (41) engage with one another under elastic tension.

9. A lighting device as claimed in claim 7 or 8, wherein: the third recess (41) has a central cavity (42) which extends from the plug-in edge (39) into the interior of the lighting device and is closed to the outside.

10. A lighting device as claimed in any one of claims 1 to 3, characterized in that: the upper part (2) and the lower part (3) each have at least one actuating projection (12, 13), wherein the two actuating projections (12, 13) are arranged adjacent to one another, but without overlapping, on the edge (7) offset in the longitudinal direction.

11. A lighting device as claimed in any one of claims 1 to 3, having a ballast (6) disposed within the housing, characterized in that: the ballast is shielded from the housing (4) by a shielding element (14).

12. The lighting apparatus of claim 11, wherein: the shielding element (14) consists of a sheet-like element.

13. The lighting device of claim 1, having a ballast (6) secured to the lower member, wherein: the ballast (6) has a first mounting hole (20) for passing a screw outwardly for mounting the lighting fixture on a wall or ceiling.

14. The lighting apparatus of claim 13, wherein: the shielding element (14) also has a second mounting opening (21) which is arranged in alignment with the first mounting opening (20) of the ballast (6).

15. A lighting device as claimed in claim 13 or 14, wherein: the lower part has a preformed through-hole (18) in the direction of the first mounting hole (20) and a second recess (24) for a sealing element (26).

16. A lighting device as claimed in any one of claims 1 to 3, characterized in that: the housing (4) consists of acrylate glass or transparent polycarbonate.

17. A luminaire as claimed in any one of claims 1 to 3, characterized in that the luminaire is a splash-proof wall lamp or ceiling lamp.