A ceiling system of this type is known. On account of the airtight character of a ceiling of this type, it is particularly suitable for rooms in which high demands are imposed with regard to clean conditions and hygiene. Examples which can be mentioned include the rooms in which semiconductor products are fabricated, which include such small details that even very small dust particles would interfere with the optical fabrication process. A further example is formed by the pharmaceutical industry, in which it is extremely important to maintain a hygienic environment. Nooks and crannies in which impurities could collect have to be avoided, since this would entail the risk of contamination.

According to a known technique, the seams in the ceiling are sealed using a cement.

However, this entails various problems. Firstly, sealing all the seams using cement in this way is very labor-intensive. A further drawback is that the cement material also itself causes contamination, for example resulting from the release of gases. In the event of a fire, the problems would be even more serious on account of the harmful combustion products which are released as a result of combustion of the cement material.

According to yet another known technique, liquid seals are used in the ceilings. In this case too, fitting a ceiling of this type is a labor-intensive operation.

Therefore, it is an object of the invention to provide a ceiling system which is airtight but does not have the abovementioned drawbacks, or at least only has them to a reduced extent. This object is achieved by virtue of the fact that the couplings each comprise a filler piece, which at one end adjoins the lateral edge of a continuous

profiled section and at the other end adjoins the end edge of an interrupted profiled section running transversely with respect to the continuous profiled section.

In the ceiling system according to the invention, the profiled sections, which run transversely with respect to one another are coupled to one another by means of a filler piece. This has the advantage that the profiled sections require little if any work for coupling them. This advantage manifests itself in particular if the end edge of the interrupted profiled section and of the opposite edge of the filler piece are planar.

The interrupted profiled section is hollow, while the filler piece has projections which fit accurately into the cavity in the interrupted profiled section. The continuous profiled section and the interrupted profiled section are identical in cross-section. All kinds of profiled sections can be used. It is preferable for the profiled sections, when seen in cross-section, to have a projecting flange on at least one raised or vertical longitudinal side.

A gasket may be located between the filler piece and the end edge of the interrupted profiled section. This gasket is enclosed between the end edge of the interrupted profiled section and the longitudinal edge of the flange of the continuous profiled section. The gasket may have ribs which fit into a cavity in the filler piece and also ribs which extend over the flange of the continuous profiled section.

A coupling pin may extend through the filler piece, the coupling pin at one end being secured to the interrupted profiled section and at the other end having a head which is accomodated in an undercut space in the raised longitudinal side of the continuous profiled section. It is preferable for the head of the coupling pin to be elongate and for the width of this head to be virtually equal to the width of the opening of the undercut space, in such a manner that the head can be hooked into the undercut space by being inserted and twisted.

The coupling pin can be secured to the interrupted profiled section by means of a clamping connection. Furthermore, the filler piece may have projections which fit into

the opening of the undercut space. These projections allow the filler piece to be fixed such that it cannot rotate with respect to the continuous profiled section.

The invention will be explained in more detail below with reference to an exemplary embodiment illustrated in the figures.

Figure 1 shows a perspective view of part of a ceiling system with a coupling according to the invention between a continuous profiled section and an interrupted profiled section.

Figure 2 shows the interrupted figure as shown in Figure 1 with a filler piece.

Figure 3 shows a perspective view of the interrupted profiled section with a gasket.

Figure 4 shows a perspective view of the gasket.

That part of a ceiling system according to the invention which is illustrated in Figure 1 shows a continuous profiled section 1, to which an interrupted profiled section 2 is connected. The ceiling system comprises a large number of couplings of this type, and it is possible for the interrupted profiled section 2 to be continued on the other side of the continuous profiled section 1 by means of a further interrupted profiled section (not shown).

The coupling, which is denoted overall by 3, comprises a filler piece 4 and a gasket 5.

This gasket 5 can be seen in Figure 3 and Figure 4. Figure 3 shows that the gasket 5 is located on the planar end edge 6 of the interrupted profiled section 2.

As can be seen from Figure 1, the continuous profiled section 1 and the interrupted profiled section 2 are identical. They each comprise a box section 7, on the underside of which two flanges 8 extend outward. The filler piece 3 is located between the box section parts 7 of the profiled sections 1,2. The flanges 8 of these profiled sections 1,2 adjoin one another.

As can be seen from Figure 3, the gasket 5 extends over the box section part and over the flanges 8. For this purpose, the gasket 5 has a box section part 9, which corresponds to the box section parts 7 of the profiled sections 1, 2, and two flange parts 10 which correspond to the flanges 8.

The box section part 9 has ribs 11 on either side, which fit into the box section part 7 of the interrupted profiled section 2, and also into the corresponding hollow filler piece 3.

The flange parts 10 of the gasket 5 likewise have ribs 12 on either side, which project over the flanges 8 of the profiled sections 1,2.

On account of the planar form of the gasket 2, of the end edge 6 and of the interrupted profiled section 2, and also on account of the fact that that side of the filler piece 3 which faces toward the interrupted profiled section 2 lies in the same plane as the adjacent flange 8 of the continuous profiled section 1, it is in this way possible to obtain an excellent airtight closure between the profiled sections 1,2.

Then, ceiling panels (not shown) are placed in a known way onto the flanges 8 of the profiled sections 1,2 and are also connected in an airtight manner by means of means which are not shown and provide an airtight seal in a manner which is known per se.

The filler piece 3 is fixed by means of a coupling pin 13. This coupling pin 13 has a head 14, which fits into the undercut space 14 in the raised side wall 15 of the continuous profiled section 1. The width of the head is such that it just fits into the opening 16 of said undercut space 14. It can then be blocked therein by being twisted.

At the other side, the coupling pin is fixed to the interrupted profiled section 2 by means of a clamping connection 17.

Furthermore, the filler piece 3 is provided with projections 18 which fit into the opening 16 of the undercut space 14. This results in the filler piece 3 being secured in such a manner that it cannot rotate with respect to the continuous profiled section 1.