The invention relates to an air grate comprising a plurality of elongated bars spaced from one another in such a way that an air passage is formed between adjacent bars, the said bars being interconnected by means of transverse joining pieces at least at two points spaced from one another by a longitudinal spacing between the bars.

Air grates of this type are used in various applications, for example in trains, buses, ships, buildings, etc. Figure 1 shows diagrammatically a perspective view of a prior art air grate 1 comprising a frame part 2 with several air guide bars 3. In the frame part 2 have been machined apertures to form transverse joining pieces 2a, 2b therein, in the area between which the slots 4 between the bars 3 make possible the through-flow of air. The area between these joining pieces 2a, 2b is typically connected to an air duct or the like. The manufacturing process of an air grate of this type is costly and material waste is, in addition, quite high.

The aim of the present invention is, therefore, to provide a method for manufacturing air grates which is relatively simple and economical regarding manufacturing costs. To achieve this aim, the air grate according to the invention is characterised in that the bars are formed as separate profiled parts, on one longitudinal edge of which is formed a connecting piece, the thickness of which decreases inwards from the outer edge, and that the transverse joining piece is comprised of a connecting profile, on which receiving grooves are formed for receiving the connecting pieces by pushing the profiled parts by their longitudinal movement with respect to the said connecting profile, and of a fixing lath positioned on the connecting profile and having an essentially U- or C-shaped cross-section, the limbs of which are dimensioned in such a way that when the fixing lath is fastened to the connecting profile, the limbs of the U settle tightly against the outer edge of the connecting pieces of the profiled parts, thus locking the profiled parts into place with respect to the connecting profile.

The invention is described in greater detail in the following, with reference to the accompanying drawings, in which

Figure 1 shows diagrammatically a prior art air grate,

Figure 2 shows diagrammatically a perspective view of an air grate made according to the invention, and

Figure 3 shows a cross-section of an example of an embodiment of Figure 2.

In accordance with Figures 2 and 3, the air grate according to the invention comprises the air grate's bar parts or air guide vanes formed as separate profiled parts 3. On one edge of the bar parts 3 is formed a connecting piece 5, which preferably has a V-shaped cross-section so that the thickness of the connecting piece 5 decreases from the outer edge towards the interior. The bar parts 3 are interconnected by means of a connecting piece 6 located transversely to the bar parts, in which connecting piece are formed receiving grooves 10 for the connecting pieces 5, the grooves preferably also being essentially V-shaped so that the V widens from the outer surface towards the interior. The connecting piece 5 and the receiving grooves 10 are dimensioned in such a way that when the connecting piece 5 is pushed into the receiving groove 10 by a longitudinal movement of the profiled part 3, between the outer edge 5a of the connecting piece 5 and the bottom of the receiving groove 10 remains a slot which facilitates the pushing of the bars into the receiving grooves. Once the connecting piece 6 has been brought into the desired position in the longitudinal direction of the ribs 3, a fixing lath or cover 7 is positioned over the connecting piece 6, the lath being essentially U- or C-shaped in cross-section and dimensioned in such a way that the limbs of the cross-section settle against the outer edge 5a of the connecting pieces 5 of the profiled parts 3. In the fixing lath 7 are formed mounting holes 8, for example, for mounting screws 9, whereupon when the mounting screws 9 are tightened to the connecting pieces 6, the limb parts of the fixing lath 7 settle tightly against the outer edge 5a of the connecting pieces 5, thus locking the profiled parts 3 into place with respect to the connecting profiled 6.

The solution according to the invention makes possible rapid assembly and dimensioning of the air grates to desired size without cumbersome machining stages.

The air grate material may be, for example, aluminium, stainless steel or other suitable material, such as a plastic composite.