Luminaire and louvre for same

Abstract: The luminaire comprises a housing (1) with a lamp holder (10a, 10b), and a louvre (20) to reduce angles at which light leaves the armature. The louvre (20) has elongate side walls (30) with a strip (31) bent back in a bending zone (32) connected to the side walls (30) and has slats (40) transverse to the side walls (30). Respective first and second tongues (41 and 42, respectively) are present at the slats which intersect the side walls (30) in slots (33, 34 respectively), the first tongues (41) hooking behind the side walls (30). The bent-back strips (31) not only press against the second tongues (42) of the slats (40), but are also tightly locked in a recess (43) in these tongues (42).

Description: The invention relates to a luminaire comprising: a housing having a luminous window with a first and a second pair of opposing sides; a lampholder for accommodating a lamp in the housing alongside the luminous window; a louvre in the luminous window provided with elongate side walls along the first pair of opposing sides of the luminous window, each having a bent-back strip at a longitudinal side connected to the side wall by a bending zone; slats transverse to the side walls; the slats having respective first and second tongues which project through slots in the side walls, the first tongues being hooked behind the side walls in a direction away from the bending zone and the bent-back strips of the side walls pressing against the second tongues. The invention also relates to a louvre for this luminaire. A louvre for such a luminaire is known from EP 0 135 086-B1. Such a louvre restricts the angle under which the light can issue to the exterior from the window. Disturbing reflections, for example on a display screen, are thus counteracted. In the known louvre, the first and the second tongues each have their own slots in the side walls, while also the second tongues are hooked behind the side walls in the same direction as the first. The bent-back strip of the side walls must keep the slats in engagement with the side walls by pressing against the second tongues. A disadvantage of the known louvre is that slats can move relative to the side walls when the louvre is manipulated, as is the case when the louvre is removed from the luminous window. Another risk is that the slats are not all held in the same position owing to the bent-back strip enclosing a varying angle over its length. Not only is it unattractive when slats assume unequal positions, but the angle at which the light emerges is also changed by it. From EP-A-0 183 179 a louvre is known in which the slats have first and second tongues which are all hook-shaped and are directed towards the bending zone of the respective side wall. An extension of the second tongues is arrested in a opening in a respective bent-back strip. The invention has for its object to provide a luminaire of the kind described in the opening paragraph provided with a louvre which, among other characteristics, is of a simple construction which provides a reliable fastening of the slats to the side walls. According to the invention, this object is achieved in that the second tongues each have a recess in which the relevant bent-back strip is enclosed with clamping fit. In contrast to the known louvre, in which friction between the relevant bent-back strip and the second tongues is the important factor for holding the slats and in which the slats are not blocked in a final position, the relevant bent-back strip in the louvre of the luminaire according to the invention bears on the second tongues in a specific spot and is fixed there. When the louvre is assembled, the bent-back strips snap themselves into the recesses in the second tongues in order to be enclosed therein with clamping fit. As a result of the defined position of the relevant bent-back strip relative to the second tongues, it is not necessary for the second tongues to be hooked behind the side walls in the same way as the first tongues. In a favourable embodiment of the luminaire, accordingly, the side walls have only one slot for each slat. This simplifies the tools with which the side walls are formed and the assembly of the louvre. In a favourable modification of this embodiment, the first and second tongues are laterally interconnected. A greater rigidity is obtained thereby, which facilitates assembly. In a very favourable embodiment, the side walls have for each slat a slot which runs into the bending zone, and the slats project through the relevant slots into the side walls and into the bending zones. This embodiment has a number of major advantages. The slots, in as far as they extend into the bending zone, fix the angle which the slats enclose with the side walls and thus prevent a rectangular louvre, for example, from assuming a parallellogram shape. Furthermore, an abutment between the slats and the side walls, such as is present in a louvre having first and second tongues hooked each behind a side wall, is avoided. Particularly attractive, however, is the strongly simplified assembly of the louvre in this embodiment. The slats may be vertically positioned on a base surface in mutual positions as occupied by them in the assembled louvre. The side walls may then be simultaneously provided in that they are made to approach the slats from above, after which the slats are passed through the slots in the bending zones of the side walls and then through the slots in the side walls themselves, until the first tongues are hooked behind the side walls. The side walls undergo a substantially linear translation during this. Finally, the bent-back strips are snapped into the recesses of the second tongues, for example, in that the strips are pressed downward and inward on either side of the slats. In a favourable modification of this embodiment, the slats hit against the bent-back strip at a distance from the second tongues. The louvre then offers a great resistance to rotation of the slats about an axis along the side walls. For achieving a very great resistance against pulling out of true of the louvre, for example from a rectangular shape into a parallellogram shape, it is favourable if the bending zones have a first and a second bend situated at a distance from one another. The bending zone may then extend partly along, for example, substantially parallel to a longitudinal side of the slats. If several lamps are included in the luminaire, it is advantageous if the louvre has between the side walls a duct-shaped intermediate wall comprising wall portions which are interconnected by a bottom portion and comprising slots in the bottom portion through which the slats are passed, the wall portions pressing into recesses in the slats and the slats having lugs which grip into slits in the respective wall portions. Such an intermediate wall may readily be provided in a louvre. Just as during fastening of the side walls, the slats can then be vertically positioned on a base surface in mutual positions which they occupy in the louvre. The intermediate wall may then be pressed into the slats in a linear translation with the wall portions pressed towards one another. The intermediate wall may then be released. The wall portions will spring back, so that the lugs grip into slits in the respective wall portions. It is immaterial for the invention whether the side walls and/or the slats are, for example, painted and anodized or whether they have a different finish. Aluminium is frequently used as the construction material. The invention also relates to a louvre suitable for use in the luminaire according to the invention. This and other aspects of the luminaire and of the louvre according to the invention are shown in the drawings, in which Fig. 1 shows an embodiment of the luminaire in front elevation. Fig. 2 is a cross-section taken on the line II-II in Fig. 1. Fig. 3 is a cross-section taken along the line III-III in Fig. 1. Fig. 4 shows a second embodiment of the louvre of Fig. 3. Fig. 5 shows a third embodiment of the louvre of Fig. 3. Fig. 6 shows a fourth embodiment of the louvre of Fig. 3. Fig. 7 is a cross-section taken on the line VII-VII in Fig. 1. In Figs. 1 and 2, the luminaire comprises a housing having a luminous window 2 with a first and a second pair of opposing sides (3 and 4, respectively). The luminaire further comprises a lampholder 10a, 10b, for example, for a low-pressure mercury discharge lamp. In the embodiment shown, this lampholder 10a, 10b consists of two parts. Alternatively, however, this lampholder may be in one part. The luminaire further comprises a louvre 20 in the luminous window 2 which is provided with elongate side walls 30 along the first pair of opposing sides 3 of the luminous window 2. At a longitudinal side, the side walls 30 have a bent-back strip (31 in Figs. 2, 3) which is connected to the side wall 30 by a bending zone 32. The louvre 20 is further provided with slats 40 transverse to the side walls 30. The slats 40 have first and second tongues (41, 42, respectively) which project through slots (33, 34) in the side walls 30 (see Fig. 3). The first tongues 41 are hooked behind the side walls 30 in a direction away from the bending zone 32. The bent-back strips 31 of the side walls 30 press against the second tongues 42. The second tongues 42 each have a recess (43 in Fig. 3) in which the relevant bent-back strip 31 is enclosed with clamping fit. In the embodiment shown, the louvre 20 has an intermediate wall 50 which is fastened in a manner shown in more detail in Fig. 7. In alternative embodiments, an intermediate wall 50 may be absent, or several of such intermediate walls 50 may be present. The number of intermediate walls 50 is often equal to the number of lamps 11 in the luminaire minus one. In Fig. 3, the first and the second tongues (41, 42, respectively) each project through their own slot (33, 34, respectively). The first tongue 41 is hooked behind the side wall 30. The bending zone 32 has a first and a second bend (35, 36, respectively) situated at a distance from one another. Alternatively, the bending zone 32 may, for example, have a single bend 35 with a greater radius of curvature than the curvature 35 shown in Fig. 3. The bent-back strip 31 may then nevertheless have the same distance to the side wall. In Fig. 4, parts corresponding to parts of Fig. 3 have reference numerals which are 100 higher. In the embodiment shown, the side walls 130 have only one slot 133 for each slat 140. The first and the second tongue (141, 142, respectively) are laterally interconnected. The tongues 141, 142 thus have a greater rigidity, which facilitates assembly. In Fig. 5, parts corresponding to parts of Fig. 3 have reference numerals which are 200 higher. The slats 240 have slots 234 which run into the bending zone 232, and the slats 240 project into the side walls 230 and into the bending zones 232 through these slots 234. As a result of this, but also of the fact that the bending zones 232 have a first and a second bend 235, 236 situated at a distance from another, the louvre (20 in Figs. 1, 2) can have a very great resistance to pulling out of true, for example, from a rectangular shape into a parallellogram shape. The slats 240 hit against the relevant bent-back strip 231 at a distance from the second tongue 242 in a location 244. In Fig. 6, parts corresponding to parts of the embodiment of Fig. 3 have reference numerals which are 300 higher. In this embodiment, the side walls 330 have only one slot 333 for each slat 340. The first and the second tongues (341, 342, respectively) are laterally interconnected. The slots 333 run into the bending zones 332 and the slats 340 project through these slots 333 into the side walls 330 and into the bending zones 332. The slats 340 hit against the bent-back strip 331 at a distance from the second tongues 342 in a location 344. The louvre (20 in Figs. 1, 2) can be easily assembled. The side walls 330 can then approach the slats 340 in a linear translation (from above in the Figure), the slats 340 being passed through the slots 333 in the bending zones 332 and then through slots 333 in the side walls 330 themselves. After the first tongues 341 have become hooked behind the side calls 330, the bent-back strips 381 may be snapped into the recesses 343 in the second tongues 342. In Fig. 7, the intermediate wall 50 has wall portions 51 which are interconnected by a bottom portion 52, and slots 53 in the bottom portion through which slats 40 are passed. The wall portions 51 press into recesses 60 in the slats 40. The slats 40 have lugs 61 which grip into slits 54 in the respective wall portions 51. The intermediate wall 50 may readily be provided in the louvre 20 in that it is passed into the recesses 60 in the slats 40 with the wall portions 51 being pressed together. After that the intermediate wall 50 may be released. The wall portions 51 will spring back, the lugs 61 of the slats 40 entering slits 54 of a respective wall portion 51.

Claims: A luminaire comprising: a housing (1) having a luminous window (2) with a first and a second pair of opposing sides (3, 4, respectively); a lampholder (10a, 10b) for accommodating a lamp (11) in the housing (1) alongside the luminous window (2); a louvre (20) in the luminous window (2) provided with elongate side walls (30) along the first pair of opposing sides (3) of the luminous window (2), each having a bent-back strip (31) at a longitudinal side connected to the side wall (30) by a bending zone (32); slats (40) transverse to the side walls (30); the slats (40) having respective first and second tongues (41, 42) which project through slots (33, 34) in the side walls (30), the first tongues (41) being hooked behind the side walls (30) in a direction away from the bending zone (32) and the bent-back strips (31) of the side walls (30) pressing against the second tongues (42), characterized in that the second tongues (42) each have a recess (43) in which the relevant bent-back strip (31) is enclosed with clamping fit. A luminaire as claimed in Claim 1, characterized in that the side walls (330) have only one slot (333) for each slat (340). A luminaire as claimed in Claim 2, characterized in that the first and second tongues (341, 342, respectively) are laterally interconnected. A luminaire as claimed in Claim 1, 2 or 3, characterized in that the side walls (330) have for each slat (340) a slot (333) which runs into the bending zone (332), and the slats (340) project through the relevant slots (333) into the side walls (330) and into the bending zones (332). A luminaire as claimed in Claim 4, characterized in that the slats (340) hit against the relevant bent-back strip (331) in a location (344) at a distance from the second tongues (342). A luminaire as claimed in Claim 1, 2, 3, 4 or 5, characterized in that the bending zones (332) have a first and a second bend (335, 336) situated at a distance from one another. A luminaire as claimed in Claim 1, 3, 5 or 6, characterized in that the louvre (20) has between the side walls (30) a duct-shaped intermediate wall (50) comprising wall portions (51) which are interconnected by a bottom portion (52) and comprising slots (53) in the bottom portion (52) through which the slats (40) are passed, the wall portions (51) pressing into recesses (60) in the slats (40) and the slats (40) having lugs (61) which grip into slits (54) in the respective wall portions (51).

Inventors: LOOMAN DIRK-JAN, LOOMAN, DIRK-JAN
Applicants: PHILIPS ELECTRONICS NV, PHILIPS ELECTRONICS N.V.
Application year: 1991
Main classification: F21V11
IPC codes: F21V11, F21S4, F21S8, F21V13