BACKGROUND Fixtures of today require considerable labouring to replace the electronics, such as removing the fixture from the ceiling, disconnecting external lines, disas- sembling the fixture, replacing the electronics including disconnecting and con- necting internal lines, assembling the fixture, connecting external lines, and then attaching the fixture to the ceiling again. All these operations constitute a danger of damaging the ceiling so that bits of plaster board may come off or similar, and marks from the first assembling may appear after re-assembly.

SUMMARY OF THE INVENTION A primary object of the invention is to provide a new construction of the entire fixture, which could consist of plastic reflector, lamp socket, connecting clamps, connecting plugs, and reactor (ballasting) with adapted electronics intern- ally, and to b@ able to produce the fiture with f@west pos$ible part$ to simplify the assembly.

This is achieved by a lighting fixture which is characterised in that it com- prises a replaceable reactor, wherein the reactor is mechanically and electrically mounted in the lighting fixture without using tools.

In one embodiment, the fixture may comprise a reflector and the replace- able reactor may then be mounted on to the reflector, such as through a connector element. A lamp socket may be integrated in the reactor unit and the lamp socket is then brought into electrical contact with the reactor after the latter has been mounted. The automatic electric contact is achieved, for example, by the fact that the lamp socket comprises male contacts (4A) and the reactor comprises female contacts (4B) that are adapted to engage each other when the lamp socket is tilted in place after mounting of the reactor. In a further embodiment, a connecting de-

vice may be attached to the reflector and the reactor will then be electrically con- nected to the connecting device.

Simple mounting of the reactor can be obtained by placing guides on the reflector so that the reactor may be pushed into the fixture. Guides may also be provided on the connecting device for mounting the reactor in the fixture. The guides may be formed as longitudinal slots or profiles and the reactor provided with complementary profiles or slots.

In one embodiment, the reflector may comprise a connecting device for the reactor for obtaining automatic electric contact between reactor and reflector. The reactor may comprise connecting pins and the connecting device may comprise connecting slots for receiving the connecting pins when mounting the reactor in the connecting device. The reflector and/or the connecting device may also com- prise tension relief means or electric support lines.

The construction of the lighting fixture permits a simple way of replacing the reactor, such as in a downlight, without having to remove the downlight and without use of tools. Several parts of the lighting fixture are integrated, such as the reactor and lamp socket, reflector and connecting clamp, and tension relief means and reflector. In this manner there will be fewer parts than usual, which is a very positive feature with respect to mounting of the fixture by an electrician, and in case of a possible replacement of the reactor when used for some time, no elec- trician is needed.

The electrical connection between reactor and fixture takes place by means of male and female pins made of metal which are integrated in the plastic hous- ings of the reactor and connecting clamps. The same applies to the electrical. con- nection between lamp socket and reactor.

Alternatively, the electrical connection can be obtained by means of lines between the reactor and the connecting clamp and/or between the lamp socket and reactor.

The invention is characterised by the features that are stated in the append-, ing independent claim 1. Preferred embodiments of the invention are defined in the appendent claims 2-11.

BRIEF DESCRIPTION OF THE DRAWINGS Embodiments of the invention will be explained in more detail with reference to the appending drawings in which: Fig. 1 is a perspective view of a lighting fixture according to the invention, showing the fixture in assembled condition; fig. 2 is a perspective view of a fixture according to the invention, showing the lamp source and reactor half way out of the fixture; and fig. 3 is a perspective view of a fixture according to the invention shown in a position in which all electricity has been disconnected and all one has to do is to lower down the lamp socket and reactor for replacement.

DETAILED DESCRIPTION Fig. 1 shows an embodiment of a light source (a downlight in fig. 1) having a replaceable reactor 2 according to the invention. The light source has a reflector 1, a lamp socket 3 for mounting a lamp source 8 therein, and a power supply in the form of a reactor 2. The reactor can be replaced and remounted in the light source without using tools. In fig. 1 the reactor is mounted to a lamp socket 3 in the light source. The lamp socket can be tiltable to permit simpler replacing of the lamp source 8.

The reactor and lamp socket could also be provided in an integrated fashion.

Fig. 2 shows an embodiment in which male and female contacts 4 are inte- grated on the lamp socket 3 and reactor 2 in a manner such that electrical contact is established between reactor 2 and lamp socket 3 when the lamp socket is tilted in place. In fig. 2 the male contacts are disposed on the lamp socket 3 and the fe- male contacts on the reactor 2, but the opposite is also possible. A connecting clamp 6 (fig. 1) integrated in the reflector 1 provides automatic electrical contacts between reactor 2 and reflector 1. In figs. 1 and 2 this is achieved by disposing connecting pins 7 on the outside of the reactor. Upon assembly, the connecting pins 7 slide into engagement with complementary slots in the connecting clamp 6 for permitting automatic electrical contact between reactor and reflector. To pre- vent tensioning of the electric support lines upon mounting/demounting and to sat- isfy current rules, line tension relief means 10 could be integrated directly onto the reflector 1 or integrated in the connecting clamp/connecting unit 6.

In one embodiment, the reflector 1 and/or connecting clamp 6 could have integrated guides 5 for mounting the reactor 2. Fig. 3 shows an embodiment in which the reflector is provided with guides in the form of longitudinal slots. The construction with the guides 5 enables simple replacement of reactor, since the reactor may simply be manually pushed in place. The direction in which the re- actor is pushed in and pulled out is shown by the double arrow in fig. 2. After hav- ing pushed the reactor in place, the lamp socket 3 is tilted back in place and elect- rical contact between the lamp socket and reactor is established through the male- female contacts 4 as noted above. The guides 5 could consist of longitudinal slots/profiles in the reflector 1 and/or connecting lamp 6, which are complementary of each other.

In a preferred embodiment, the mechanical (guides 5) and electrical (con- necting slots 9 and connecting pins 7) guides are primarily between connecting clamp and reactor. This provides a flexible approach, which may easily be used on other fixtures. The attachement between connecting clamp 6 and reflector 1 could be established by way of any known attachement means, but a snap connection is preferred. In that case by snap latches on the connecting clamp 6 slatching into the reflector 1, when the connecting clamp 6 is pushed in place in the reflector 1 along complementary guide slots between connecting clamp 6 and reflector 1. The electrical contact is between connecting clamp-reactor, reactor-lamp socket and lamp socket-lamp source.

The fixture could be designed in such a manner that one or more reactors could be mounted in the same fixture. Alternatively, one reactor could also be made, for being used with two or more lamp sources on the same reactor. The reflector/lamp socket housing 1 and/or connecting clamp 6 is constructed with guides for the reactor (s) and the reactor is provided with mating slots guiding the latter into correct position in the fixture, where it will be automatically connected to electricity.

In the production of the various parts of the fixture well known techniques may be used, such as injection moulding of the plastic parts, integrating metal parts and electronics for obtaining the desired function by means of the special construction as described above. In plastic moulding there is also the opportunity to integrate several functions in one and the same operation (moulding), such as integrating tension relief means, cover, snap locks, etc.