The present invention relates to an air diffuser comprising a body part with an air flow channel passing there through and a brace for supporting a flow control disc, the brace having an elongated shape extending across the cross section of the flow channel and the brace being made from the same material blank as the body part and the center point of the brace having an inner- threaded hole made thereon to accommodate the center shaft of the flow control disc.

The air diffuser may be an inlet air diffuser or an exhaust air diffuser intended for mounting on a room wall or ceiling. The term air diffuser body part refers to a terminal element that is designed mountable on the end of an air flow duct and has a brace for attaching to the diffuser a flow control disc, generally in an ad- justable fashion. The brace is a member extending across the air flow channel and conventionally having an inner-threaded hole at its center point. Into this hole is rotated the control disc center shaft with a compatible outer thread.

Conventionally the brace is attached to the diffuser body part by welding the brace at its both ends to the body part. Inasmuch as the brace must support the diffuser air flow control disc resting on threads thereon, the brace shall be sufficiently rigid for this function. Generally this kind of separate brace member is made from a thicker material than the diffuser body part. However, a separate brace to be attached to the body part involves additional worksteps.

From the prior art is also known a diffuser having the brace of its body part manufactured from the same blank as the body part. Herein the sufficiently high rigidity of the brace is secured by using three radial legs in the brace design in lieu of the conventional two legs. However, this kind of brace is diffi- cult to fabricate and, furthermore, the additional legs of the brace impede the air flow through the diffuser and increase the annoying noise generation.

It is an object of the present invention to provide an air diffuser having its brace made of the material blank as the diffuser body part and yet being free from the shortcomings of the prior art techniques. An air diffuser according to the invention is characterized in that the brace is bent into a substantially U- shaped cross section and the flanges of the brace cross section are affixed to each other at least at one point about either side of the brace center hole.

A preferred embodiment of the invention is characterized in that the flanges of the brace cross section are affixed to each other by welding.

A second preferred embodiment of the invention is characterized in that the flanges of the brace cross section are affixed to each other by rivets.

A further preferred embodiment of the invention is characterized in that the flanges of the brace cross section are affixed to each other using a crimping technique.

A still further preferred embodiment of the invention is characterized in that the flanges of the brace incorporate tabs at which the flanges are affixed to each other.

Accordingly, the basic concept of the invention is to fabricate the brace from the same blank as the air diffuser body part whose material thickness is too thin for conventional designs. Affixing the flanges of the brace cross section to each other at least at two points increases substantially the rigidity of the brace. This is a particularly valuable advantage in larger air diffusers. Without having its flanges affixed to each other, the brace cannot be made sufficiently rigid to support the diffuser control disc.

In the following, the invention is described in more detail with reference to the appended drawings in which

FIG. 1 shows an axonometric view of an air diffuser body part and its brace in a workstep having the brace cross section bent into an essentially U-shaped form;

FIG. 2 shows the assembly of FIG. 1 , now in a top view;

FIG. 3 shows the assembly of FIGS. 1 and 2, now in a side elevation view;

FIG. 4 shows an axonometric view of an air diffuser body part according to the invention and its brace in a workstep having the flanges of the brace cross section affixed to each other at two points; and

FIG. 5 shows the assembly of FIG. 4, now in a top view.

Now referring to FIGS. 1-3, therein is shown an air diffuser body part 1 with its brace 2. The brace has an elongated shape extending across the cross section of the diffuser air flow channel. The brace is connected to the body part at the rim of the air flow channel. The brace is made of the same material blank as the body part such that the unnecessary portions of the body part are first cut off and thereupon the material portions of the brace coinciding with the air flow channel are bent into their final shape. In the worksteps of FIGS. 1-3, the cross section of the brace is bent into a substantially U-shaped form. At the center point of the brace is fabricated a conventional inner-threaded hole 3 to accommodate the rotation of the treaded shaft of an air flow control disc (not shown), thus making the diffuser controllable by rotation of the control disc.

Reference numeral 4 designates tabs fabricated to the flanges of the brace such that allow the flanges to be affixed to each other in the fashion shown in FIGS. 4 and 5. In the design illustrated in the diagrams, two tabs are provided at both flanges of the brace, one tab at either side of the center hole 3 of flange. The tabs may be adhered to each other by, e.g., welding or riveting or using a crimping technique. However, any equivalent affixing

technique may be employed as well. Affixing the tabs to each other makes the brace more rigid and supportive under the torsional forces imposed by the control disc.

To a person skilled in the art it is obvious that the invention is not limited by the above-described exemplifying embodiments, but rather may be varied within the inventive spirit and scope of the appended claims. Accordingly, the number of affixing points at the brace flanges can be more than two or, alternatively, the flanges are affixed to each other along their entire length. The tabs of the flanges may also be omitted, particularly in larger braces.