EP1779034A1

EP1779034A1 - Lighting fixture mounting box

Info

Publication number: EP1779034A1
Application number: EP05760616A
Authority: EP
Inventors: Michael VELSØ
Original assignee: El-Forum APS
Current assignee: El-Forum APS
Priority date: 2004-07-19
Filing date: 2005-07-19
Publication date: 2007-05-02
Also published as: WO2006007852A1; DK200401131A

Abstract

Known mounting boxes for halogen spotlights consist of several parts, and particular boxes are used for disposing the power supplies to the lamps. The installation can only occur from below. According to the invention there is provided mounting boxes that only consist of one part, and where two may simply be joined when the power supply can be placed. The construction enables installation from above as well as from below.

Description

Lighting fixture mounting box.

The invention relates to a mounting box for lighting fixtures, in particular for installation in ceiling constructions.

A known type of modern light sources are the so-called halogen spotlight, which are frequently low voltage reflector bulbs, i.e. they have a supply voltage of 12 V. The bulbs have contact pins which are fitted into a socket in a heat resisting insulating material. Halogen spotlights are particular in that they do not radiate their heat in the same direction as the light because the reflecting layer permits the heat to be radiated uniformly into the surroundings, which are thereby heated. In cases where light sources are supplied directly from the mains voltage, the installation fixtures must protect against electrical shock, but a halogen light source, possibly comprising a low voltage supply, is protected by using heat-resistant materials close to the light source (and thereby the source of heat), and by applying a distance, termed a safety distance, to the surroundings so that they are not heated to become a fire risk.

Halogen spotlights are frequently installed in ceiling constructions which are the lower side of a roof construction consisting of ceiling, diffusion barrier, insulation, windproofing and roof material. By a diffusion barrier is not necessarily understood a total block for diffusion of water vapour but a considerable reduction of the diffusion in order that the outwards transport in the insulating material is sufficient to remove possible penetrated water vapour. The mounting of the fixture itself with a front glass may occur in the ceiling, and halogen spotlights are frequently fitted in groups, in that a number are supplied from the same voltage source, which is a transformer or an electronic converter from mains voltage to the supply voltage. Because of the radiation of radio interference (EMC) and for safety reasons there are rules for the maximum length of the supply wires and the number of connectors in a low voltage supply circuit. This is due to the heat generation at the contact resistances in the connectors, because the current at the low supply voltage is large. When the fixture is fitted in the ceiling the diffusion barrier is broken, and this is disadvantageous from an insulation point of view. To ensure that the safety distance to the surrounding parts - in this case the loft insulation - is maintained and to ensure that the diffusion barrier is not left with large openings due to the safety distance, special mounting boxes, so-called spotlight mounting boxes, are used for the installation. A suitable cavity is created in the insulating material, a spotlight mounting box is fitted, and its edge is sealed to the diffusion barrier. Due to the risk of overheating, the voltage source must not receive radiation directly from the light source, and for this reason a spotlight mounting box may be supplied with a dividing wall. Spotlight mounting boxes must be made of an electrically insulating material, which is furthermore heat resistant.

The individual spotlight mounting boxes may be connteced by means of electrical conduit, through which are brought the connecting wires, e.g. from a central box with the power supply. The power supply is fed from the mains, where the rules of the Electrical Supply Regulations for disposing wires and cables apply. In a well- structured building project the fitting of spotlight mounting boxes and the required wiring are performed before the insulating work and the finishing of the roof construction, and in this case it is simple to fit heat insulation around the spotlight mounting boxes installed beforehand. However, the installation work is required to be performed from below, through the openings in the spotlight mounting boxes, as it will be noted that spotlight mounting boxes in a ceiling construction have their bottoms facing upwards. When revising a finished installation, for instance several years subsequent to the original installation, this can only be performed from below, while damaging any ceiling material provided.

Known spotlight mounting boxes consist of a box part and a lid part and supplied with punch-out parts of walls, through which cables and conduits may be brought.

For a complete installation a spotlight mounting box with a separating wall for each voltage source is furthermore required. Such a spotlight mounting box will be bigger than a simple spotlight mounting box. This means that the electrician has to maintain four item numbers in stock in order to be able to perform this type of installation work: a simple spotlight mounting box, a spotlight mounting box with a separating wall and lids for the above boxes.

It has turned out to be inflexible and a disadvantage to perform work with simple spotlight mounting boxes with separate lids, irrespective of building work or retrofitting of halogen spotlight and their fittings and voltage sources. These disadvantages are overcome according to a construction according to the invention which is particular in that the bottom of the mounting box is connected to the mounting box in a rim area with reduced wall thickness and in that the bottom immediately adjacent to this rim area has a thickened rim terminating in a circumferential groove. This construction entails that the bottom may be removed by cutting through the thin part of the wall, whereupon installation work may progress from above and be finalized by re-creating a tight closure by pressing the thickened rim through the hole, the edge of which catches the circumferential groove. Subsequently tools are needed to remove the bottom again. This is a part of the

Electrical Supply Regulations. The provision of a bottom that may be removed and re-fitted according to the regulations entails that a revision of an installation in a ceiling material may occur from above, in a loft space with a gangway, in that a spotlight mounting box may simply be exposed, the revision of wires and fittings performed, and the bottom may be fitted without any disturbance of the ceiling material.

An advantageous embodiment of the mounting box according to the invention is particular in that it has, close to its mouth, a lid connected thereto by means of a film hinge, said lid being locked in place in its closed position by snap action in the frame of the opening. Thereby the mounting box and its lid are made in one piece and are stocked with one item number.

A further advantageous embodiment of the invention is additionally particular in that the mounting box on opposite sides has fields defined by circumferential areas of reduced wall thickness, at least one of said fields being excisable for creation of an opening, which, when two mounting boxes are fitted together, creates a common frame for a connection between the two, and in that there are provided fixing means for said boxes. In this use of two spotlight mounting boxes one has to be reversed so ^

that its opening faces upwards. Hereby the advantage is obtained that one box may be used as a separate space for the voltage source, and the other for a halogen spotlight, while the two boxes constitute a tight and strong unit. The installation in the box that faces the habitual way may occur from above, in that the installation of the light fixture is concluded by snapping the removed bottom into the opening that appeared by the removal. However, it may also occur from below, in that the voltage source is brought through the opening between the two spotlight mounting boxes with its cables. Installation of the voltage source from above is concluded by snapping the foil hinged lid into its frame, from which it can only be removed by means of tools, as mentioned above.

A further advantageous embodiment of the invention is particular in that the fields defined by circumferential areas of reduced wall thickness have previously marked fields, which may be pushed or cut out for accomodating cables and conduits, as well as membranous parts that may be penetrated and thereby retain wires in the wall material. This embodiment has in particular manufacturing advantages, because all parts that must display a tight thickness tolerance (the penetrable parts), are collected within the two areas that are constituted by the fields mentioned above. This will also simplify the use of a different type of polymer for the fields and their penetrable parts than the type used for the mounting box itself.

The invention furthermore covers the use of a plurality of spotlight mounting boxes for the above mentioned installations.

The invention will be described in greater detail in the following with reference to the drawing, in which

Fig. 1 shows a spotlight mounting box according to the invention, Fig. 2 shows a detail of the lid, Fig. 3 is a partial cut of a side and bottom

Fig. 4 is an enlarged representation of the joint between bottom and side,

Fig. 5 is a corresponding enlarged representation of the connection between the side and the frame of the opening, Fig. 6 shows an assembly of two spotlight mounting boxes according to the invention, and Fig. 7 shows the same assembly from a different angle.

In Fig. 1 is seen a spotlight mounting box 1 with a lid 2 which is made in one piece with the box and connected by means of a living hinge 3. A field 4 is surrounded by a rim 5 which is a part of the wall, which along the rim has a very much reduced wall thickness compared to the spotlight mounting box 1 in general. The opening of the spotlight mounting box is surrounded on three sides by a frame part 6. Within the field 4 there are blanks 7, 7' which may be cut out and membranous parts 8 that may be burst and retain a wire by pinching the insulation. The lid 2 may be pressed into the spotlight mounting box, and cooperating plastic parts on the lid and on the frame prevent the lid from being removable without the use of tools. The bottom 9 is elevated slightly above the plane where the side edges of the box end, in order to function in the manner that is described below with reference to Fig. 4.

When using the spotlight mounting box a suitable seal is ensured between the frame 6 of the box and the diffusion barrier, e.g. by using adhesive tape or an adhesive. A tolerance between the lid and the frame may be provided so that the foil is caught when the lid is closed. After laying the cables the spotlight mounting box is closed, the diffusion barrier is established, and the ceiling material is fitted. As the centre of the spotlight mounting box has been marked beforehand, one may drill a hole from below upwards through the ceiling material and the lid 2 of the spotlight mounting box with a shell auger, and hereafter the wires may be connected to the light fixture.

In Fig. 2 is seen an enlarged representation of the area around the living hinge 3, and the arrow 3 shows how the lid 2 may be swung around the hinge 3 and fit inside the frame 6.

In Fig. 3 is shown a sectioned side with a field 4 and a surrounding rim 5 as well as blanks 7 and a deformable membrane 8, which has parts 8' and 8" that are pushed apart and may retain a wire. The blanks 7 leave holes that are sufficently big to allow the introduction of electrical conduits, possibly with clips for tension relief, and correspondingly the smaller holes left by the blanks T are suitable for cables. In Fig. 4 the area close to the bottom 9 is shown in greater detail, and by hatching of the section in the wall of the spotlight mounting box it is emphasized how the thickness varies according to the purpose. In the upper part of the drawing it is shown how a thinner part of the wall connects the bottom 9 to the rest of the spotlight mounting box. This part of the wall may be cut by a knife, whereby the bottom comes off. The bottom has a rim with a guide surface 11' and a bead 11 and is terminated by a circumferential groove 12 that corresponds to the hole in the spotlight mounting box that is left when the bottom 9 is cut out. When the required installation work has been performed through the hole in the spotlight mounting box the bottom 9 is fitted again, in that the thickened part passes the hole and subsequently fixes the bottom 9 to the spotlight mounting box. This construction of the bottom 9 enables installation from above, which constitutes a considerable rationalization of the work in new constructions.

In Fig. 5, in a corresponding greater detail is shown the area closest to the opening and frame 6 of the spotlight mounting box. By hatching of the section in the wall of the spotlight mounting box it is emphasized how the thickness varies according to the purpose. In particular it is seen that the detail 8 is constituted like jaws that are held together by a very thin membrane 8a that is penetrated by pushing the end of a wire against the wall from the outside. In case the material of the box is very stiff it may be necessary to use a tool, such as a drift. Hereby the wire is pinched so that the wall of the box may constitute a tension relief. Furthermore there is shown a hole 13 outside the rim 5 with a thin bottom that has to be penetrated together with the corresponding hole in the oppositely oriented spotlight mounting box when the assembly takes place, cf. Fig. 6, in order that a joining element may be fitted.

In Fig. 6 is shown how two spotlight mounting boxes are assembled in order that a separate chamber for the voltage source is obtained, e.g. a transformer or an electronic power supply. The drawing is shown from above in connection with a fresh installation before the fitting of thermally insulating material. If voltage source, wiring, and fixture all have to be mounted from above the following procedure is used. Before the assembly the two spotlight mounting boxes are identical. The field 4 is removed from the two sides of the boxes that have to be fitted together. The holes 13 are opened on both boxes by means of a suitable pointed tool. The bottom 9 of the spotlight mounting box is cut off, and the two edges 5 are fitted against each other (while turning the voltage source box 1' around, whereby its wall inclination is identical to the wall inclination of the spotlight mounting box 1). Locking elements are inserted in the holes 13 and the just assembled unit is fitted by suitable means to the structural parts of the building. The voltage source is placed in the box I¹. If the voltage source is to supply a number of halogen spotlights, the necessary wires may be brought through the opening between the two boxes and further through the openings 7', 8 that are best suited for this. The necessary wiring and fitting is performed, whereupon the bottom 9 is brought below the frame part 6' of the voltage source box and is pressed into the opening in the spotlight mounting box, in order that it is closed securely again, cf. the description above in conjunction with Fig. 4.

Fig. 7 shows how the assembly of the two identical boxes is seen from below, if the diffusion barrier is imagined as a transparent layer shown by hatching. In practice there will only be an opening in the diffusion barrier where the lid part of the spotlight mounting box is disposed. The installation may occur from below, in that cut-outs are made in the diffusion barrier corresponding to two spotlight mounting boxes and corresponding thermal insulating material is removed. Hereafter the two asssembled boxes are fitted, while cables which have previously been laid to the desired placement of halogen spotlight are pulled through the holes T. A hole is cut in the lid 2 for the spotlight mounting box, it is closed, and the cut diffusion barrier below the voltage source box is cemented. Hereupon the required ceiling material is fitted.

Minor variations in the elements that form part of the above description may well occur without deviating from the concept of the invention, for which reason the description can only be regarded as an examplary embodiment.

Claims

oPATENT CLAIMS

1. A lighting fixture mounting box (1), in particular for installation in ceiling constructions, characterized in that the bottom (9) of the mounting box is connected to the mounting box in a rim area (10) with reduced wall thickness and in that the bottom immediately adjacent to this rim area has a thickened rim (11) terminating in a circumferential groove (12).

2. A mounting box according to claim 1, characterized in that it (1) close to its mouth has a lid (2) connected thereto by means of a film hinge and with a snap action in its closed position.

3. A mounting box according to claim Ior2, characterized in that the mounting box on opposite sides has fields (4) defined by circumferential areas (5) of reduced wall thickness, at least one of said fields (4) being excisable for creation of an opening, which, when two mounting boxes (1, 1') are fitted together, creates a common frame for a connection between the two, and in that there are provided fixing means (13) for said boxes.

4. A mounting box according to claim 3, characterized in that the fields (4) defined by circumferential areas (5) of reduced wall thickness have previously marked fields (7, T), which may be pushed or cut out for accomodating cables and conduits, as well as membranous parts (8', 8", 8a) that may be penetrated and thereby retain wires in the wall material.

5. The use of mounting boxes according to any of the preceding claims for use in installing light fixtures as well as power supplies for such light fixtures, characterized in that two mounting boxes (1 , 1') are fitted oppositely, in order that facing sides are parallel, and that flush openings are created between said mounting boxes are created by removal of fields (4) defined by circumferential areas (5), and that joining means (13) are used to maintain the mounting boxes in this position.