The present invention relates to an air diffuser device for ventilating rooms and to be installed in a ventilation duct opening in a wall or ceiling of a room.

Such devices are known for example from US617677 or US3299797.

A common problem found in such air diffuser devices is noise caused by air flow through the devices.

It is an object of the present invention to reduce or modify all sorts of noises caused by air flow through such an air diffuser device and prone to be a nuisance to persons in a room provided with such an air diffuser device.

According to a first aspect of the present invention, this object is achieved by an air diffuser device for ventilating rooms and to be installed in a ventilation duct opening in a wall or ceiling of a room, said air diffuser device comprising a baffle element having a central region and a peripheral region with a peripheral edge for deviating at least a part of a ventilation air flow entering said room through said ventilation duct opening in a flow direction with an air flow component parallel to said wall or ceiling, characterized in that said baffle element comprises a plurality of slits or grooves each extending from the central region of said baffle element to the peripheral region of said baffle element.

It has been surprisingly found that air flowing through such an air diffuser device causes less or even hardly any noise at least in the human audible spectrum.

In addition, vertical air flows causing draft and discomfort can be avoided.

Preferably, said baffle element comprises peripherally open slits or grooves which are open at the peripheral edge of said baffle element. This slit or groove geometry causes little turbulence in the air passing along the baffle element with a radial flow pattern from a center to the periphery of the baffle element.

Alternatively, said baffle element may comprise peripherally closed slits each having a bridge portion in the peripheral region for bridging the gap at the peripheral end of each slit. Such bridge portions increase the rigidity of the baffle element and may be used in cases where the baffle element has a small thickness.

Preferably, said baffle element comprises only peripherally open slits which are open at the peripheral edge of said baffle element. As mentioned above, such open slits tend to produce little turbulence in the air flowing along the baffle element.

According to a second aspect of the present invention, this object is achieved by an air diffuser device, preferably comprising the features of the diffuser device according to the first aspect of the present invention, wherein the peripheral edge of said baffle element has a plurality of radially extending indentations spaced from each other along the periphery of said baffle element.

Again, it has been surprisingly found that air flowing through such an air diffuser device causes less or even hardly any noise at least in the human audible spectrum.

The indentations may be spaced at regular or irregular intervals along the periphery of said baffle element.

The peripheral edge of said baffle element may have a zigzag-like or sawtooth-like contour.

Alternatively, the peripheral edge of said baffle element may have a wave-like or sinusoidally-shaped contour.

Preferably, said indentations form a contour line extending along the circumference of the baffle element, the maximum depth of said indentations being between 1/60 and 1/10, preferably between 1/50 and 1/30, of the average radial extension of the baffle element. With these dimensions, a significant noise reduction can be achieved.

Preferably, the air diffuser device further comprises a mounting element for mounting said baffle element to a ventilation duct. The mounting element and said baffle element may be connected to each other in the central region and/or in the peripheral region of said baffle element.

Preferably, the mounting element and said baffle element are formed integrally, i.e. in one piece as a monobloc.

Alternatively, if the mounting element and the baffle element are not formed integrally, said mounting element may have first formations and said baffle element may have second formations, said first and second formations being complementary to each other for connecting said baffle element to said mounting element.

Preferably, said mounting element and said baffle element are connected adjustably with respect to each other.

Preferably, the contour of said baffle element along a radial direction from the central region to the peripheral region of said baffle element has a point of inflexion defining a change in curvature from a radially internal curvature region to a radially external oppositely curved curvature region of said baffle element. Again, it has been surprisingly found that this contributes to achieving less or even hardly any noise at least in the human audible spectrum.

Preferably, the contour of said baffle element along a radial direction from the central region to the peripheral region of said baffle element is substantially S-shaped.

Preferably, the point of inflexion is located at a radial position along the baffle element contour, wherein the radial extension of the radially external curved region of said baffle element is less than the radial extension of the radially internal curved region of said baffle element. Again, this contributes to achieving less or even hardly any noise at least in the human audible spectrum.

More preferably, the point of inflexion is located at a radial position along the baffle element contour such that the radial extension of the radially external curved region of said baffle element is between 1/10 and 1/3, preferably between 1/8 and 1/4, of the radial extension of the radially internal curved region of said baffle element.

Preferably, said baffle element is a first baffle element and said air diffuser device further comprises a second baffle element located at a position upstream of said first baffle element. Preferably, said baffle element is rotationally symmetric with respect to an axis extending across the center point of its central region.

Preferably, said second baffle element is rotationally symmetric with respect to an axis extending across the center point of its central region.

In a very advantageous embodiment, the axial spacing (distance) between said second baffle element and said first baffle element is adjustable. As a result, the air gap and thus the flow resistance of the diffuser device may be adjusted.

Preferably, at least one of said first and second baffle elements is threadably mounted by a thread element having as its thread axis the axis extending across the center point of the central region of said first and second baffle elements. This allows a continuous adjustment of the gap.

Preferably, at least one of said first and second baffle elements has angularly spaced surface markings positioned along a circle having as its center the center point of the central region of said first and second baffle elements.

Preferably, the axial spacing (distance) between said second baffle element and said first baffle element is manually adjustable.

In a very advantageous embodiment, the air diffuser device comprises an adjustment and locking element for locking the adjusted axial spacing (distance) between said second baffle element and said first baffle element. As a result, a well-defined gap can be maintained.

Alternatively, the air diffuser device may comprise a drive element for adjusting the axial spacing (distance) between said second baffle element and said first baffle element.

A further advantage of the air diffuser device according to the invention, when mounted at a ceiling opening or at a wall opening, is the fact that less air is directed to the ceiling or to the wall, thus causing less pollution on the ceiling.

Further applications, features and advantages provided by the present invention will become more apparent from the following description and the drawings. Fig. 1 shows several views of a preferred embodiment of the air diffuser device of the present invention.

Fig. 2 shows several views of a component of the preferred embodiment of the air diffuser device shown in Fig. 1.

Figs. 3 to 7 show an embodiment similar to the preferred embodiment of Fig. 1 highlighting further components and functional elements included in the preferred embodiment of Fig. 1.

In Fig. 1 , an air diffuser device 1 for ventilating rooms and to be installed in a ventilation duct opening in a wall or ceiling of a room is shown. The air diffuser device 1 comprises a first baffle element 10 having a central region 10a and a peripheral region 10b with a peripheral edge 12/13 for deviating at least a part of a ventilation air flow entering said room through said ventilation duct opening in a flow direction with an air flow component parallel to said wall or ceiling. The baffle element 10 comprises a plurality of slits or grooves 11 each extending from the central region 10a of said baffle element 10 to the peripheral region 10b of said baffle element 10. In addition, the air diffuser device 1 has a peripheral edge 13 of said baffle element 10 having a plurality of radially extending indentations 14 spaced from each other along the periphery of said baffle element 10. The indentations 14 are spaced at regular intervals along the periphery 10b of said baffle element 10. The peripheral edge 10b of said baffle element 10 has a wave-like or sinusoidally-shaped contour at its periphery 10b. In addition, the air diffuser device 1 comprises a second baffle element 20. Between the two baffle elements 0 and 20 a gap is defined. The air diffuser 1 also comprises a fan element 40 having a first fan blade 41 , a second fan blade 42 and a third fan blade 43.

In Fig. 2, the first baffle element 10 is shown in more detail. The baffle element 10 comprises peripherally open slits or grooves 11 which are open at the peripheral edge 12/13 of said baffle element 10. In addition, the peripheral edge 12/13 of said baffle element 10 has indentations 14. A contour or contour line S of said baffle element 10 along a radial direction from the central region 10a to the peripheral region 10b of said baffle element 10 has a point of inflection SPI defining a change in curvature from a radially internal curvature region Sa to a radially external oppositely curved curvature region Sb of said baffle element 10. The contour S of said baffle element 10 along a radial direction from the central region 10a to the peripheral region 10b of said baffle element 10 is substantially S-shaped.

In Figs. 3 to 7, an embodiment similar to the preferred embodiment of Fig. 1 is shown highlighting an adjustment and locking element 30 for locking the adjusted axial spacing (distance) between said second baffle element 20 and said first baffle element 10.

Figs. 6 and 7 show the locking mechanism in a locked an unlocked position, respectively.

Reference numerals

1 air diffuser device

10 (first) baffle element

10a central region

10b peripheral region / periphery

11 slots or grooves

12 peripheral edge

13 peripheral edge

14 indentations

20 second baffle element

30 adjustment and locking element

40 fan element

41 first fan blade

42 second fan blade

43 third fan blade

50 cover plate

S contour line S of said baffle element

Sa radially internal curvature region

Sb radially external oppositely curved curvature region

SPI point of inflection