EP0271770B1 - Device for attaching a light cover to its enclosure - Google Patents

Description

The invention relates to a holding device of a lowerable or removable metallic lamp cover, in particular a metal grid, on a lamp housing made of sheet metal with a resilient, bare wire bracket which, arranged on the lamp cover, passes through a section of the lamp housing and is guided in a vertically displaceable manner on it with prestressing while maintaining ground contact is.

Such a holding device is known for example from EP 0 116 909 B1. Here, an M-shaped suspension spring engages in a spring holder attached to the lamp housing, which forms a guide space for the legs of the suspension spring. Projections of the legs slide along the side walls of the bare spring holder, which is made of rust-free sheet metal, as the lamp cover is pulled down. This in turn is mechanically and therefore electrically connected to the lamp housing, so that ground contact is established.

The known holding device is disadvantageous insofar as the spring holder is an additional part which must be mechanically attached to the lamp housing with further parts. These fasteners receive mutual ground connection mostly via bare cut edges of the housing plate, which arise during processing of the sheet, which is preferably coated with paint. If, on the other hand, the luminaire housing is subsequently painted after complete processing, the cut edges are also covered and electrically insulated, so that, for example, simple riveting of the spring holder does not readily provide sufficient ground contact.

It is an object of the invention to improve a holding device of the type mentioned in such a way that a simple and effective means of achieving an effective ground connection between a lamp housing, in particular coated on all sides, and a metallic lamp cover is achieved, in order to reliably separate these into the electrical positions in their various functional positions Protective measures of the luminaire to be included.

This object is achieved by a holding device with the characterizing features of claim 1. Further developments and advantageous refinements of the invention are specified in the dependent claims.

The holding device according to the invention has the advantage that earth clips that are provided for guiding wire brackets or retaining springs in the lamp housing can be plugged on without tools, which automatically lock there without impairing the function or the appearance of the lamp. The paint is partially scraped off and there is a sufficiently reliable ground contact between the sheet metal of the lamp housing and the earth clamp, which in turn is transferred from the wire bracket to the lamp cover. This ensures continuous electrical protection between the earthed lamp housing and the lowerable or hinged and, if necessary, also removable metallic lamp cover. Neither rivets, welding work nor separate cable connections are required to achieve good ground contact between the lamp parts.

Fig. 1

zeigt eine Teilansicht einer Innenleuchte mit einer Halteeinrichtung in perspektivischer Darstellung, während in

Fig. 2

die Halteeinrichtung vor der Montage mit den Leuchtenteilen in Explosionsdarstellung wiedergegeben ist. In

Fig. 3

ist die Ansicht der Halteeinrichtung und in

Fig. 4

die zugehörige Seitenansicht mit einer ersten Ausführungsform der Erdklammer dargestellt. Die

Fig. 3a

zeigt schematisch vereinfacht eine zweite Ausführungsform der Erdklammer.

The invention is explained in more detail using exemplary embodiments with reference to the drawing.

Fig. 1

shows a partial view of an interior lamp with a holding device in perspective, while in

Fig. 2

the holding device is shown with the lighting parts in an exploded view before assembly. In

Fig. 3

is the view of the holding device and in

Fig. 4

the associated side view shown with a first embodiment of the earth clip. The

Fig. 3a

shows schematically simplified a second embodiment of the earth clip.

The interior lamp shown only in partial view has a channel-shaped lamp housing (1), which is provided on its light exit surface with a metal grid (2) as a lamp cover. The metal grid is formed from two longitudinal webs (2a) which run in the longitudinal direction and serve to direct the light, with cross-blades (2b) which provide the glare and are generally known as such. A light source, not shown, for example a fluorescent lamp, is arranged above the transverse slats. In order to be able to replace them, the metal grid (2) can be removed or at least folded down on the lamp housing (1). For this purpose, several holding devices are arranged between the metal grid and the lamp housing on both long sides of the lamp.

Such a holding device shown has a U-shaped or V-shaped resilient wire bracket (4) which is fastened to the metal grid (2) with a bearing element (3) and, with its legs (4b), has a slot-shaped cutout (1a) in the lamp housing (1). reaches through and rests there. The wire bracket (4) which is pivotably mounted on the side webs (2a) of the metal grid is in metallic contact with an earth clip (5 or 5 bzw.) which the cutout (1a) at least at an intended contact zone to his legs (4b) under tension are limited. The earth clamp is connected in a manner to be described in more detail to the luminaire housing, which is coated with varnish on all sides, only mechanically and at the same time in an electrically conductive manner.

The wire bracket (4) is held by means of the bearing element (3) which is designed as a U-shaped leaf spring and which is elastically snapped on with the pretension of its legs (3a) in the outwardly angled edge region (2aʹ) of the side webs. The curved legs (3a) of the bearing element form an eye (3b) as a pivot bearing for the wire bracket (4) and its linear apex zone (4a). In the area of the eye (3b) a protruding spring tongue (3c) is cut free, which presses elastically on the apex zone (4a) with cutting edges (3cʹ) and thus ensures earth contact between the wire bracket and the bearing element. The latter is provided in one leg with two tongue-shaped cut-out locking cams (3d) and in the opposite leg with pointed claws (3e). When attaching the bearing element to the edge area (2aʹ) of the side bar, the claws (3e), which are provided with a run-in slope, slide onto the mostly anodized sheet metal of the metal grid and thereby make metallic contact, while the locking cams (3d) enter correspondingly recessed holes (2c) Snap elastically into the edge area and get caught there with their respectively adapted contours. It is then no longer possible to remove the bearing element (3) from the side bar. The wire bracket (4), however, can be freely pivoted in the eye (3b) in cooperation with the cutting edge of the side web (2a) (FIG. 3, FIG. 4).

The connection of the metal grid to the luminaire housing is achieved via the wire bracket (4), each of which has a constriction (4bʹ) in both legs above the apex zone (4a) and then has a V-shape up to angled extend the free ends (4bʺ) outwards. The constrictions (4bʹ) lock in cooperation with the cutout (1a) of the lamp housing, the operating position of the metal grid (Fig. 1, Fig. 3), which can be lowered manually from this position. The legs (4b) slide within the respective cutout (1b) under prestress to the free ends (4bʺ), with at least one leg continuously having metallic contact with the earth clamp (5 or 5ʹ). If the metal grid is to be folded down, for example, to change the lamp, then after lowering the wire clips on one side of the housing must be pressed together by hand until the ends (4bʺ) unhook from the corresponding cutout (1a). To completely remove the metal grid, the wire clips on both sides must be unhooked accordingly. In addition to the U or V-shaped brackets shown, other bracket shapes can be used on one or both sides of the metal grid. It only has to be ensured that the legs of the wire bracket bear with sufficient pretension on the earth clip that delimits the cutout in the lamp housing.

The earth clips (5 or 5ʹ) are preferably made of spring steel, bent in a U-shape and with molded, pointed claws pushed tightly onto the sheet of the lamp housing coated with lacquer. In a first embodiment (Fig. 2, Fig. 3, Fig. 4) the earth clip is pushed from the edge of the housing plate (1b) over the cutout (1a) and in both legs in addition to pointed claws (5a) protruding in pairs in the direction of the plate surface. provided with superposed recesses (5b, 5c), the shape and size of which is adapted approximately to the cutout (1a) in the lamp housing. At least one of the recesses, preferably the lower recess (5c), is, however, smaller or narrower than the cutout (1a) in such a way that the legs (4b) of the wire bracket that are under tension are metallic the cut edges of the recess (5c) at least at the designated contact zones. In contrast, the larger cutout (1a), the edges of which can be coated with varnish, only serves to pass the wire bracket and to center the earth clamp. In addition to the pointed claws (5a), this also has barbs (5d) which engage in the cutout (1a) and hook behind a cutout edge. The earth clip, which is supported on the housing plate (1b) with its connecting web (5e), is thereby centered and held captive. Only the pointed claws (5a), which are adapted to the sheet thickness and partially scrape off the paint on the lamp housing, thus establish the ground connection to the lamp housing to be earthed on the installation side and transfer its earth contact to the earth clamp.

In a second embodiment (Fig. 1, Fig. 3a), the earth clip (5ʹ) is also U-shaped with pointed claws (5ʹa) facing each other and directly from the cutout (1a) of the lamp housing over a narrow side to the surrounding housing plate (1b ) postponed. As a result, the length of the cutout (1a) is somewhat shortened and the wire bracket (4) lies against the web (5ʹe) with a metal bias. The earth clip (5ʹ) is centered directly from the longitudinal edges of the cutout (1a) and secured against slipping out by the wire bracket (4). Here, too, the pointed claws (5ʹa), which are protruded in pairs in both legs, establish the metallic contact with the housing plate by partially scraping off the paint on the surface of the sheet when it is pushed on. Of course, an earth clip (5ʹ) can also be pushed onto both narrow sides of the cutout (1a), so that both legs of the wire bracket (4) get ground contact to the lamp housing.

Both forms of the earth clamp are matched with the claws (5a or 5ʹa) to the thickness of the housing plate in such a way that sufficient scraping effect during assembly on the painted sheet until it comes into contact with the luminaire housing. The wire bracket reliably takes over this contact from the earth clamp in all functional positions and transfers it via the spring tongue (3c) to the bearing element (3), which in turn has intimate contact with the metal grid due to the claws (3e). This means that there is a continuous electrical earth connection from the luminaire housing to the metal grid and the required protection against accidental contact is guaranteed.

Claims (10)

1. Retaining equipment of a lowerable or removable light fitting cover, in particular a metal grid, at a light fitting housing made of sheet metal with a resilient blank wire bracket which is arranged at the light fitting cover, engages through a cut-out of the light fitting housing and which is guided thereat to be displaceable in height with bias while maintaining earth contact, characterised thereby, that the cut-out (1a) co-operating with the wire bracket (4) is bounded at least in partial regions by means of an electrically conducting earth clip (5, 5'), which is pluggable in self-retaining manner onto the sheet metal of the light fitting housing (1) and by pointed claws (5a) penetrates a present insulating lacquer layer of the light fitting housing (1) to make earth connection.
2. Retaining equipment according to claim 1, characterised thereby, that the earth clip (5, 5') is bent into about U-shape and provided at both limbs with claws (5a, 5'a), which point one towards the other and are pushable onto the lacquer-coated sheet metal, which bounds the cut-out (1a), of the light fitting housing (1) to lie closely against both sides and in this case scrape over the surface.
3. Retaining equipment according to claim 1 and 2, characterised thereby, that in the case of a slot-shaped cut-out (1a) receiving a wire bracket (4) springing open in about V-shape, the earth clip (5') is matched to one narrow side of the cut-out (1a) and pushable with both limbs within the cut-out (1a) over one of the narrow cut-out edges onto the surrounding sheet metal (1b) of the light fitting housing (1), while the web (5'e) connecting the limbs of the earth clip (5') forms the contact zone to the wire bracket.
4. Retaining equipment according to claim 1 and 2, characterised thereby, that the earth clip (5) is pluggable from a lateral edge of the light fitting housing (1) over the cut-out (1a) onto the sheet metal (1b) surrounding it and itself displays a recess (5c), which after the plugging-on is arranged about congruently with the cut-out (1a), wherein the recess (5c) is dimensioned to be narrower at least at the envisaged contact zones for the wire bracket (4) than the associated cut-out (1a) at the corresponding places.
5. Retaining equipment according to one of the claims 1 to 4, characterised thereby, that the earth clip (5) is provided, apart from the claws (5a) for the earth contact, additionally with barbs (5d) preventing the pulling-off.
6. Retaining equipment according to one of the claims 1 to 5, characterised thereby, that the earth clip (5) is detentable by the barbs (5d) behind a cut edge of the cut-out (1a) and arranged with the recess (5c) self-centring over the cut-out (1a).
7. Retaining equipment according to one of the claims 1 to 6 with a wire bracket bent into about U-shape and borne in its apex to be movable at the light fitting cover, characterised thereby, that the wire bracket (4) is retained by a line-shaped apex zone (4a) in a one-piece bearing element (3), which as metallic leaf spring, which is bent into U-shape and engages around the wire bracket (4), is pluggable with bias onto a lateral web (2a) of the light fitting (cover metal grid 2) and arrestable there by means of locking dogs (3d) and that respective elastically constructed contact zones are arranged between each of the light fitting cover (metal grid 2), the bearing element (3) and the wire bracket (4).
8. Retaining equipment according to claim 7, characterised thereby, that the bearing element (3) at its eyelet (3b) engaging around the open zone (4a) of the wire bracket (4) displays a recess, in which a spring tongue (3c), which acts by cutting edges (3c') on the wire bracket (4), is arranged to be standing free as contact zone.
9. Retaining equipment according to claim 7 and 8, characterised thereby, that the bearing element (3) is provided on at least one limb side (3a) with claws (3e), which protrude in tightening direction and serve as earth connection to the light fitting cover (metal grid 2).
10. Retaining equipment according to claim 7 to 9, characterised thereby, that locking dogs (3d) are set out in tongue shape in one limb (3a) at the bearing element (3), after the snapping-on detent into correspondingly adapted holes (2c) in the lateral web (2a) of the lighting fitting cover and are secured in the direction of tension.

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