AIR DIFFUSER WITH REMOVABLE DIFFUSER PLATE

Abstract

 The invention relates to an air ventilation diffuser 1 e.g. a ceiling mounted air ventilation diffuser. The diffuser 1 comprises a plenum box 2 and a removable diffuser plate 3. The plenum box 2 is provided with a ventilation air inlet 4, adapted to be attached to a ventilation system in order to provide air into the plenum box 2, and a ventilation air outlet 5 for admitting air to a space where the air ventilation diffuser 1 is located. The removable diffuser plate 3 is provided with one or several openings 6 and being adapted to fit and cover the ventilation air outlet 5 of the plenum box 2. The removable diffuser plate 3 is attached to the plenum box 2 by at least one resilient element 7, e.g. a spring, being fixed to the plenum box 2 and the diffuser plate 3 so as to force these elements towards each other. The diffuser plate 3 may shift between a first, operative position (I) and a second, access position (II) by stretching the resilient element 7 and dislocating the diffuser plate 3.

Description

TECHNICAL FIELD

[0001] The invention relates to an air ventilation diffuser for an air ventilation system for a building.

BACKGROUND ART

[0002] Air ventilation diffusers are present in essentially all modern ventilation systems in buildings. A function of the diffuser is to provide for an improved control of ventilation air from the ventilation system into a space, e.g. a room. The diffuser is thus forming part of the outlet of the ventilation system. A diffuser could for example be designed to comprise a plenum box which receives air from the ventilation system through an inlet opening and admits air to the space to be ventilated through an outlet opening. The outlet opening of the plenum box is in general provided with a diffuser plate, e.g. a cover plate which is provided with outlet openings or holes. These openings or holes are designed to divide and direct the air stream in desired directions in the space to be ventilated. In many cases are the outlet openings or holes easily adjustable in order to be able to set the air stream in a desired direction, either by adjusting the complete plate, a group of openings or individually adjust each of the openings.

[0003] The diffuser plate may be made such that it is easy to remove it in order to access the inside of the plenum box. This may be desired in order to control some functional element in the plenum box, e.g. a valve or a sensor. To open the plenum box could also be used for accessing the ventilation channel system, e.g. for commissioning, installation or cleaning. An example of a removable front plate may for example be found in SE 533 285. The front plate is kept in its closed position by one or several fixing elements which are fitted into corresponding openings, e.g. spring sheet metal which resiliently is forced into a locking position. The cover may be completely removed or allowed to be attached by hooks forming hinges when the front plate is removed from its covering position. Another device disclosing a detachable air diffuser unit is disclosed in US 3,064,550 wherein V-shaped spring elements are fitted into slots in order to attach the air diffuser unit to the outlet. The plate may be removed from its covering position and be lowered while still being attached by the ends of the legs of the V-shaped spring element or being completely detached by pressing the legs of the V-shaped element towards each other in order to escape out of the slots.

[0004] In US 3,044,106 is disclosed still another attachment arrangement for removably attaching a cover to a housing, e.g. for enclosing a fan. The arrangement comprises a spring element which is used in constructing a hinge mechanism. The cover may be detached from its covering position by a rotational movement of the attachment arrangement and the arrangement is designed to resiliently keep the cover in a locked position respectively an open position.

[0005] All the documents above disclose different attachment arrangements for removably attaching a cover to an opening. The attachment arrangements above are further designed to allow the covers to be partly attached while the cover is removed from its position covering the opening. Even though the removable covers described above provides for different designs of attachments there is still a desire for an improved attachment arrangement which in an easy manner may be adapted to a multitude of different covers and openings while also allowing the cover plate to be easily removed and attached again, preferably allowing the cover to be completely detached as well as only removed from the opening while still being attached if desired. Hence, there is a desire to provide an alternative cover which could be removably attached in an easy way

SUMMARY OF THE INVENTION

[0006] The invention is related to an air ventilation diffuser suitable to be used in an air ventilation system for a building. An air ventilation diffuser is an arrangement for distributing ventilation air, e.g. from an air ventilation system, to a space, e.g. a room in a building. The air ventilation diffuser described herein is suitable to be mounted to or in a ceiling even though it may be mounted for example on a wall also. The air ventilation diffuser comprises a plenum box and diffuser plate. A plenum box is a chamber for receiving air from an air ventilation system. A plenum box need not to be "box" shaped but may have other shapes, e.g. cylindrical or spherical. The plenum box could for example have a back plate and side walls and the back plate being located opposite to the place where the diffuser plate should be positioned. The term "plenum box" is herein used for any device having the function of being a chamber formed by a casing having an inlet intended to be connected to an air ventilation system and an outlet for distributing air to a space to be ventilated. Hence, the plenum box comprises a ventilation air inlet, adapted to be attached to a ventilation system in order to provide air into the plenum box, and a ventilation air outlet for admitting air to a space where the air ventilation diffuser is located. In a simple design, a plenum box could also be the ventilation tube (or end portion of the tube) located in the room to be ventilated.

[0007] The diffuser plate, which also may be referred to as front panel, is provided with one or several openings. The diffuser plate is adapted to fit and cover the ventilation air outlet of the plenum box. A "diffuser plate" could thus be represented by essentially any kind of device, regardless of its shape, which is fitted to a ventilation air outlet in order to distribute and direct the air from the outlet. Hence, air from the plenum box is admitted to the room or space to be ventilated through the at least one opening or hole in the diffuser plate. In general, a diffuser plate is provided with a multitude of openings or holes for controlling and directing the air stream as desired. The diffuser plate is arranged to be removable in order to allow access into the interior of the plenum box. There is a desire to make the removal of the diffuser plate to be simple to perform, in particular when the plenum box is located in the ceiling and it may be needed to work in a tiresome position. Hence, if possible, it is desired to reduce the time needed to detach the diffuser plate from the plenum box and avoid the need for precision work and unnecessary tools for detaching the diffuser plate.

[0008] According to the invention is the diffuser plate attached to the plenum box by at least one resilient element. The resilient element is attached to the plenum box and the diffuser plate so as to force these elements towards each other. The term resilient element is intended to include any kind of element being able to contract and stretch so as to considerably change its length as a result of a force working on the element, e.g. one or several springs or one or several elastic bands such as rubber bands. There are several different kinds of springs which may be used such as tension springs, compression springs, constant springs or torsion springs. A typical spring is the coil spring, also referred to as helical spring. A suitable spring may be selected depending on the desired design and required operating environment. Springs are generally made from spring steel. However, almost any material can be used to construct a spring, so long as the material has the required combination of rigidity and elasticity. As is obvious, also constant springs or other elements which provides for an elongation of a rigid wire between a first attachment point in the plenum box and a second attachment point in the diffuser plate could be used.

[0009] Even though the spring is intended to provide sufficient force to keep the diffuser plate in its position covering the ventilation air outlet could there be some guiding arrangement assuring that the diffuser plate is in its right position. This could for example be a rim on the diffuser plate adapted to fit the ventilation air outlet.

[0010] The resilient element may be located inside the plenum box. To place the resilient element inside the plenum makes it less plausible that someone unintentionally moves the spring or that it may interfere negatively when mounting the plenum box and reduce the risk of the resilient element to be stuck between the plenum box and wall or ceiling where the plenum box is mounted. The resilient element is preferably attached to the inside of the plenum box and on the side of the diffuser plate facing the plenum box. However, the resilient element could of course also be attached to the outside of the plenum box or the side of the diffuser plate facing away from the inside of the plenum box while still stretching through the inside of the plenum box.

[0011] The resilient element is thus intended to provide a sufficient force to keep the diffuser plate in its desired position covering the ventilation air outlet when the ventilation system is working and air is admitted to the space where the ventilation diffuser is located. However, the force from the resilient element shall be sufficiently weak such that it may be possible to extend the resilient element in order to dislocate the diffuser plate from its position when covering the air ventilation outlet. Hence, the resilient element is adapted to be able to be extended in order to change the diffuser plate from a first, operative position (I), also referred to as a "closed mode" since the diffuser plate is covering the ventilation air outlet, to a second, access position (II), also referred to as an "open mode", in which the diffuser plate is removed from covering the ventilation air outlet. In the first, operative position is thus the diffuser plate attached to the plenum box by the resilient element and covers the ventilation air outlet such that essentially all ventilation air passing through the ventilation air outlet is forced to pass through the openings in the diffuser plate. In its second, access position (II) is the diffuser plate dislocated from the ventilation air outlet and access to the interior of the plenum box via the ventilation air outlet is allowed while the diffuser plate still is attached to the plenum box by the resilient element.

[0012] The air diffuser is further designed such that the attachment by the resilient element is designed to allow the diffuser plate to be moved freely in essentially any direction while changing from its first, operative position (I) to its second, access position (II). This has the advantage of allowing the attachment of the diffuser plate to have a simplistic design without the need for any advanced guiding arrangements while allowing a great freedom in how to positioning the plate when removed from the air diffuser outlet. In addition, it will enable the diffuser plate to easily be completely detached.

[0013] Hence, according to one aspect of the invention the attachment arrangement of the resilient element or elements is made such that the diffuser plate may be turned and dislocated as desired when removed while still being attached by the resilient element or elements. This may be achieved by using coil springs or resilient straps as the resilient elements. Hence, by designing the air diffuser and its attachment to the diffuser plate such that the plate may easily be removed and disconnected except for attachments by resilient straps, elongated coil springs or the like devices could a large degree of freedom in moving the plate be achieved. Hence, if the resilient elements are resiliently extendable may the plate be turned and moved essentially free in three dimensions as desired while of course being somewhat restricted by the force from the resilient elements and the movement of the plate also having a maximum limit in how far the resilient elements may be extended. However, the plate may be moved without restriction from guiding elements defining a specific pattern the plate needs to follow. The arrangement is preferably designed such that there are some kind of guiding means which, together with the resilient force striving to force the diffuser plate towards the air diffuser, will keep the diffuser plate in its desired position when it is in its first operative position (I). In addition, there may be guiding means for defining one or several positions when the diffuser plate is in its second, access position (II).

[0014] According to still another aspect of the invention is the resilient element arranged such that the diffuser plate may be removed by moving it straight out from its covering position (first, operative position (I)), e.g. being moved vertically from a position covering an opening in a ceiling. By allowing the diffuser plate to be able to move straight out from its first operative position (I) when removed will it be possible to attach the cover in small and confined spaces as well as locating the air diffuser and the cover plate without needing to think about how the diffuser plate is oriented in case it is mounted close to a pillar or wall.

[0015] If desired, the resilient members could be provided with some kind of quick connecting feature, e.g. a hook and loop arrangement allowing the resilient member to be disconnected from the diffuser plate or the air diffuser.

[0016] In general, the resilient element is attached to the plenum box and the diffuser plate such that the elongation or extension of the resilient element is essentially proportional to the distance the diffuser plate is moved away from the access opening if it is moved straight away from the opening, e.g. when moved away in a direction perpendicular to the surface of the diffuser plate, when the diffuser plate is removed from its first, operative position (I) away from the access opening. This is for example the case when the resilient element is extending in a direction perpendicular to the surface of the diffuser plate and the diffuser plate is moved straight away from the air diffuser in which case the extension of the resilient element will be the same as the distance the plate is moved away. If the resilient element is somewhat inclined relative an axis perpendicular to the surface of the diffuser plate will the extension not be the same but still essentially proportional.

[0017] The diffuser plate is preferably arranged to the plenum box such that it may be completely detached from the plenum box (except for its attachment via one or several resilient elements) without the need for unscrewing or other kind of release action needing the use of any tool.

[0018] The diffuser plate is forced towards the ventilation air outlet by the resilient element. However, the diffuser plate is preferably adapted to the ventilation air outlet such that it will be properly guided to be correctly positioned in the first, operative position (I) and cover the ventilation air outlet. This could for example be achieved by designing the edges of the diffuser plate and the ventilation air outlet to fit each other, e.g. by designing the rim of the diffuser plate to surround and make a close fit with the rim of the ventilation air outlet. This could of course be made by other fittings as well. Hence, there is a desire to provide the arrangement with some aligning or positioning feature in order to assure that the diffuser plate not will askew. If the plate is designed to be properly kept in position this way it could also be provided with some locking feature aiding in carrying the weight of the diffuser plate. For example, one side of the plate could be provided with a mechanical locking feature, e.g. a protrusion in the plate adapted to fit in with a hole in the ventilation air outlet. The protrusion could be inserted to the hole where after the diffuser plate is allowed to be pulled into its position by the resilient element and in this position is the diffuser plate locked for lateral movements by for example interaction of the rims of the diffuser plate and the ventilation air outlet while the interlocking arrangement and the resilient element are carrying the weight of the diffuser plate. In general, if such an interlocking arrangement is used, it should be desired to have an arrangement which may be released without the need of any tool, preferably released by dislocating the diffuser plate in only one direction.

[0019] The plenum box and the diffuser plate could be designed such that the diffuser plate in its second, access position (II) is turned at least 45 degrees relative a plane parallel to the surface of the diffuser plate when the diffuser plate is in its first operative position (I). The plate could more preferably be turned at least 60 degrees. The diffuser plate should not generally be turned more than 120 degrees. This may be achieved by designing the attachment points and force from the resilient element (or elements) and the shape of the plenum box and the diffuser plate such that the diffuser plate will have a stabilized equilibria from the force from the resilient element or elements and support from the plenum box.

[0020] The diffuser plate could for example be designed to be partly comprised in the plenum box when it is in its second, access position (II). This could for example be easily achieved by allowing the diffuser plate to be completely detached from its contact with the plenum box (except for the resilient element(s)) when its position is changed from the first operative, position to its second, access position (II). When the diffuser plate is detached may it be appropriately turned and located partly (or even completely) inside the plenum box where it is stabilized by the spring forces from the resilient element(s) and support from the plenum box. This feature may be used for any kind of geometrical shape of the plenum box and the diffuser plate but is in particular suitable for a circular shaped diffuser plate fitted onto a cylinder shaped plenum box (or at least a circular air outlet). The rounded shape of both the plate and opening make it possible for the diffuser plate to be turned and fitted into the opening of the air diffuser while only being needed to be removed a rather short distance from its first, operative position (I). The attachment may be one single resilient element located in the centre of the diffuser plate. Alternatively, the resilient element may be attached between the centre and the circumference, e.g. at least attached 1/3 of the distance between the centre and the circumference away from the centre, on a desired location such that the force from the resilient element may be adapted to a proper value for keeping the plate in place in its first, operative position (I) as well as positioning it with a desired force to be properly positioned in its second, access position (II) when partly comprised in the plenum box.

[0021] The plenum box could also be provided with guiding means used to keep the diffuser plate in a desired position when the diffuser plate is positioned in the second, access position (II). These guiding means could be located to guide the diffuser plate to be located partly or completely inside the plenum box or outside. Existing elements could be used for this purpose, e.g. could a flexible material inside the plenum box, such as a sound absorbing mat, and the natural flexibility of the thin metal sheet material be used to stabilize the position of the diffuser plate. As another example, guiding pins or a groove could also function as guiding means.

[0022] The ventilation diffuser could be designed such that the diffuser plate is attached to the plenum box by one single resilient element. As an example, the resilient element could be attached to the centre of a round diffuser plate adapted to fit a round ventilation air outlet of a plenum box. Even though one single resilient element is used, it could be attached to several attachment points in the diffuser plate or the plenum box, .e.g. by using several wires attached to either unit and attaching these wires to the resilient element.

[0023] However, the diffuser plate may be attached to the plenum box by the use of two or more resilient elements as well. For example could two or more resilient elements be attached along a row on the diffuser plate and essentially follows a straight line. The resilient elements could thus help in stabilizing the diffuser plate when it is located in its second, access position (II).

[0024] If several resilient elements having different spring constants are used it may be possible to even better control the positioning of the diffuser plate when it is in its second, access position (II). For example, if resilient elements having different spring constants are positioned at two or more attachment points or lines of attachment points may the difference in the spring constants causing the resilient elements contract different such that they different lengths when the diffuser plate is positioned in the second, access mode (II) such that they cause the diffuser plate to swivel and aid in keeping the diffuser plate in a steady position.

[0025] Hence, by using resilient elements having different spring constants and/or designing their attachment points at specific locations may the positioning of the diffuser plate in the second, access mode be better controlled. The resilient elements should of course also be designed to keep the diffuser plate in its appropriate location also when the plate is in the first, operation mode (I).

[0026] Even if several resilient elements are used for attaching the diffuser plate, these could be attached to a single attachment point.

[0027] The resilient elements are thus in general designed to be attached at a first fixed point, e.g. at one end of the resilient element, to the diffuser plate and a second fixed point of the flexible element, e.g. the other end, to the plenum box. When several resilient elements are used may there of course be several independent attachment points on the diffuser plate respectively on the plenum box.

[0028] In order to work as desired is it of importance that the pulling force from the resilient elements is within a desired interval. The total force from the resilient element or elements pulling the diffuser plate towards the ventilation air outlet in the first, operative mode should preferably be less than 200 Newton in order to be able to remove the diffuser plate to be set in the second, access position (II). In many cases may it be enough, or even desired with less force and the pulling force could be desired to be less than 150 Newton or even below 100 Newton in order to facilitate the removal of the diffuser plate. On the other hand, the force may not be too small in order to provide for a secure attachment and not risk to be dislocated when the diffuser plate is in the first, operative position (I) why the pulling force should be at least 10 Newton and more preferably at least 20 Newton and most preferably at least 30 Newton. The specific force used may also be set dependent on the size of the diffuser plate, the larger the plate is, the larger may the force be. This is partly a result from the forces from the ventilated air being larger for large diffuser plate. The forces 'given above is set for when the ventilation is turned off.

[0029] The size of the diffuser plates may vary considerably and the invention is at least intended to be useful for diffuser plates covering a ventilation air outlet having an area of at least 0,005 square metres, in particular above 0.01 square metre and most preferably above 0.025 square metres. The area is preferably less than 2 square metres, more preferably less than 1.50 square metres and most preferably less than 1.00 square metres.

[0030] The resilient elements to be used may have an elongated shape and being resilient in its longitudinal direction. Hence, a typical such element is an ordinary metal spring. Resilient element may also include an element which comprises a stiff portion and a resilient portion, e.g. an element comprising a spring portion and a non-extendable portion, e.g. a wire.

[0031] The design and shape of the air ventilation diffuser may differ. The air ventilation outlet from the plenum box may have an essentially circular cross sectional area and the diffuser plate may have the shape of a circular disc. However, a square shaped diffuser plate could also cover a round ventilation air outlet or both the air ventilation outlet and the diffuser plate could be rectangular, e.g. square shaped. The air ventilation outlet may of course also be rectangular, e.g. square shaped, or have any desired shape.

[0032] In the above, it has been described that the diffuser plate may switch from a first, operative position (I) to a second, access position (II). This second, access position (II) is mainly intended to be used for readily access the interior of the plenum box. However, there may also be an interest in providing another embodiment of the access mode (II) in which there is only opened up a small slot between the diffuser plate and the air ventilation outlet of the plenum box. This may for example be used when there is a desire to keep the diffuser plate open during maintenance work or inspection when a tool is inserted into the ventilation system. The plenum box may thus have been provided with some support guides adapted to fit with the diffuser plate such that the diffuser plate may be positioned in a half open position in which the resilient element or elements are stretched such that a gap or slot is provided between the plenum box and the diffuser plate.

[0033] The invention also relates to an air ventilation system for a building comprising an air ducting system for distribution of ventilation air in the building which is connected to an air handling unit for producing an air flow in the air ducting system which comprises a ventilation air diffuser as described above.

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The present invention will be explained below by means of non-limiting examples with reference to the accompanying drawings, in which:

Fig. 1 a-c shows a first embodiment of a diffuser having a diffuser plate attached to the plenum box by a resilient element in different modes;

Fig. 2 a-e shows variations of the design of the resilient element in the diffuser of the first embodiment in fig. 1;

Fig. 3 shows a variation of the first embodiment in fig. 1 in which the diffuser plate is provided with hinges

Fig. 4 shows a variation of the first embodiment in fig. 1 in which the diffuser plate is provided with a bayonet locking feature

Fig. 5 shows a design modification of the first embodiment in fig. 1

Fig. 6 shows a variation of the resilient element in the design modification in fig 5

Fig. 7 shows a schematic view of a ventilation system provided with a diffuser according to the invention.

DETAILED DESCRIPTION OF THE DRAWINGS

[0035] In figure 1 a-c is disclosed a diffuser 1 comprising a plenum box 2 provided with a removable diffuser plate 3. The diffuser1 is intended to form part of a ventilation system and to receive air from a ventilation ducting system via a ventilation air inlet 4 and admit air through a ventilation air outlet 5. The diffuser plate 3 is intended to fit the ventilation air outlet 5 such that air to be admitted passes through the holes or apertures in the diffuser plate 3. The ventilation outlet 5 is also intended to function as an access opening in order to access the interior of the diffuser 1 by removing the removable diffuser plate 3. The diffuser 1 has further been provided with a resilient element 7 which in this case is present as a coil spring and is attached to the diffuser plate 3 and the plenum box 2 in order to force these elements towards each other.

[0036] In figure 1 c is the diffuser 1 shown when it is in its second, access position (II) which also may be referred to as an open mode. In this access position (II) is thus access into the interior of the diffuser 2 allowed. The diffuser plate 3 is in this mode dislocated or removed compared to its ordinary position covering the air ventilation outlet 5 when the air ventilation system is normally used for ventilation, which is referred to as a first, operative position (I) and is disclosed in figure 1c. The state of the diffuser shown in figure 1c is also referred to as a closed mode since the diffuser plate 3 is covering the air ventilation outlet 5.

[0037] The diffuser plate 3 may switch from its first, operative position as shown in figure 1c by simply moving the diffuser plate 3 downwards, i.e. away from plenum box 2 and the air ventilation outlet 5 such that these parts are separated except for their attachment via the resilient element 7. This state is shown in figure 1c. When the diffuser plate 3 is in this state may it simply be turned and allow the resilient element 7 to pull the diffuser plate 3 towards the plenum box 2 and partly enter through the air ventilation outlet 5 such that it is partly comprised in the plenum box 2.

[0038] The diffuser 1 shown in figure 1 thus allows the diffuser plate 3 to be easily removed from its position covering the air ventilation outlet 5 without the need to use any tools. In addition, the attachment by the resilient element 7 also ensures that the diffuser plate 3 not will fall down completely. The resilient element 7 thus provides for some kind of safety attachment. The resilient element 7 could of course be attached, e.g. to the diffuser plate 3, with some kind of fast connector such that it may be completely detached from the plenum box 2 if desired.

[0039] In figure 2 a - e are different variations of arrangements of the resilient element 7 in figure 1 disclosed. In these figures is the diffuser 1 disclosed in its first, operative position (I) and for the sake of simplicity in showing the arrangement of the resilient element(s) 7 has the side walls of plenum box 2 been removed.

[0040] In figure 3a has the positioning of the attachment point of the resilient element 7 to plenum box 2 been shifted compared to figure 1. In figure 1 was the resilient element 7 attached to the centre of the access panel 3 and a backing plate of plenum box 2. Here, in figure 3a, the attachment point to the backing plate has been adjusted to be off set such that the diffuser plate 3 could be easier positioned differently in its access position. The diffuser plate 3 may still be positioned properly in its first, operative position (I) due to aligning arrangement, e.g. by using edges of the circular diffuser plate 3 to fit in with the edges of the round envelope surface (not shown) of the plenum box 2.

[0041] In figure 2b is still another variant of the diffuser 1 shown in which there are two resilient elements 7 which has been attached to diametrically opposite sides of the backing plate of plenum box 2 and to the centre portion of the diffuser plate 3. In figure 2c is the diffuser 1 disclosed having three resilient elements 7 which are positioned along a diameter cross sectional line of the diffuser plate 3 and stretching essentially perpendicular to the plane of the diffuser plate 3 to be attached to the backing plate of plenum box 2. In figure 2d are there also three resilient elements7 present which are attached to a central point in the backing plate of plenum box 2 and distributed to be attached to the circular diffuser plate 3 equidistantly from each other and centred around the centre point of the diffuser plate 3. In figure 2e the resilient element 7 is also attached to attachment points of the circular diffuser plate 3 which are located equidistantly from each other and the centre point but this time via wires 8. The resilient element is in its other end attached to the centre portion of the backing plate of plenum box 2.

[0042] The designs of the resilient element or elements 7 and the attachment to the diffuser plate 3 and plenum box 2 is intended to serve as examples that there are several ways of connecting the diffuser plate 3 to plenum box 2 which may be beneficial from different aspects, e.g. concerning how the diffuser plate 3 may be located due to the force from the resilient elements 7 and the shape of the diffuser when the diffuser plate 3 is in its second, access position (II). These, or other configurations, could of course also be used for the embodiment disclosed in figure 2 and there are of course the same possibilities to change the design and location of the resilient element 7 for other designs of the diffuser, e.g. having square shaped diffuser plate 3 or access openings. In these examples, the resilient elements have been attached to the backing plate of the casing but it could of course be attached to the side walls or any other part as well.

[0043] In figure 3 is disclosed a variant of the first embodiment of the diffuser 1 in which the diffuser plate 3 has been provided with hinges 9 connecting the diffuser plate 3 to plenum box 2. The diffuser plate 3 may thus shift between its open and closed position in an easier way. However, this design implies further details to be added to the diffuser and a more complicated construction even though it may provide the advantage of a more desired movement of the diffuser plate 3. The resilient element could be centrally located, as disclosed in figure 3a, or set off, preferably towards a part more distant from the hinges 9 as disclosed in figure 3b

[0044] In a modified embodiment of figure 3 (not shown), the hinges could be replaced for some kind of arrangement with a protrusion and indentation, e.g. a hole and a locking pin, which cooperate to form a locking arrangement when the diffuser plate 3 is in its first, operative position (I). When the resilient element is stretched and the access plate is swivelling around the locking arrangement could the locking arrangement be released and the diffuser plate 3 is attached to plenum box 2 only by the resilient element 7.

[0045] In figure 4 is disclosed how a mechanical locking arrangement using L-shaped indentations 10 on plenum box 2 and pins 11 on the diffuser plate 3 is used in addition to the resilient element 7. In this case the pins and indentations are forming a bayonet locking arrangement. In figure 4a is the diffuser 1 shown in its first, operative position (I) in which the pins 11 and L-shaped indentations 10 are engaging. When the diffuser plate 3 is turned will it disengage and it will be possible to lower it while still being attached by the resilient element 7 as disclosed in figure 4b. The diffuser plate 3 may thereafter be turned if desired to open up the air ventilation outlet 5 further. In figure 4c is disclosed a detailed view of the L-shaped indentation 10 and the pin 11. Preferably, 2 to 4 of these locking arrangements are provided on the diffuser 1.

[0046] In figure 5 is disclosed a design modification of the embodiment disclosed in figure 1. In figure 5 is the diffuser plate 3 designed to be square shaped and the air ventilation outlet 5 is also square shaped. In figure 5a is the diffuser 1 with a centrally located resilient element 7 shown in its second, access position (II) in which the diffuser plate 3 is turned essentially 90 degrees relative its plane when it is covering the air ventilation outlet 5 in its first, operative position (I) and also distorted to be partly comprised in the access opening. To change to be in the first, operative position (I) is the access plate first located in the right plane (fig 5b) where after its turned in the same plane to be aligned (see fig. 5c) where after it is allowed to be pulled to its first, operative position (I) by the resilient element (see figure 6d). Hence, this figure discloses essentially the same arrangement as in figure 1 but with a square design instead of round.

[0047] Figure 6 also discloses a square shaped plenum box 2 of a diffuser 1 in its first, operative position (I) in fig 6b and in its second, access position (II) in fig. 6a. The diffuser plate 3 has been provided with hinges 9 and constant force springs as resilient elements 7.

[0048] In figure 8 is disclosed a building 101 which has been provided with a ventilation system 102. The ventilation system comprises a ducting system 103 for distributing air which is connected to an air handling unit 104 for inducing a pressure in the ducting system and a multitude of air diffusers1 as described above mounted to the ceiling for admitting air from the ducting system 103 into the building.

[0049] The examples disclosed above only serves as some examples on how the invention may be realized. The specific shape of the diffuser plate 3 and the air ventilation outlet 5 may differ from what is disclosed in the examples and the idea of using a resilient element may be used for any shapes of these elements as long as the diffuser plate is designed to fit with the access opening. The full scope of the invention is defined by the claims.

Claims

1. An air ventilation diffuser (1), in particular a ceiling mounted air ventilation diffuser, comprising a plenum box (2) and a removable diffuser plate (3), said plenum box (2) provided with an ventilation air inlet(4), adapted to be attached to a ventilation system in order to provide air into the plenum box (2), and an ventilation air outlet (5) for admitting air to a space where the air ventilation diffuser (1) is located, said removable diffuser plate (3) being provided with one or several openings (6) and being adapted to fit and cover the ventilation air outlet (5) of the plenum box (2), the diffuser plate (3) being attached to the plenum box (2) by at least one resilient element (7) having a longitudinal extension and being resilient in its longitudinal direction whereby the diffuser plate (3) and the plenum box (2) are forced towards each other by means of the contracting force of the resilient element (7), said resilient element (7) adapted to be able to be extended in order to change the diffuser plate (3) from a first, operative position (I), in which the diffuser plate (3) is attached to the plenum box (2) by the resilient element (7) and covers the ventilation air outlet (5) such that ventilation air passing through the ventilation air outlet (5) is forced to pass through the openings (6) in the diffuser plate (3), to a second, access position (II) in which the diffuser plate (3) is dislocated from the ventilation air outlet (5) and access to the interior of the plenum box (2) via the ventilation air outlet (5) is allowed while the diffuser plate still is attached to the plenum box (2) by the resilient element (7)
characterized in that
the attachment by the resilient element is designed to allow the diffuser plate to be moved freely in essentially any direction while changing from its first, operative position (I) to its second, access position (II).

2. An air ventilation diffuser (1) according to claim 1 characterized in that the diffuser plate (3) in its second, access position (II) is positioned such that it is turned between at least 45 degrees, more preferably at least 60 degrees, and 120 degrees relative a plane parallel to the surface of the diffuser plate (3) when the diffuser plate (3) is in its first operative position (I).

3. An air ventilation diffuser (1) according to any previous claim characterized in that the diffuser plate (3) is at least partly comprised in the plenum box (2) when it is in its second, access position (II).

4. An air ventilation diffuser (1) according to any previous claim characterized in that the plenum box (2) is provided with guiding means used to keep the diffuser plate (3) in a desired position when the diffuser plate (3) is positioned in the second, access position (II).

5. An air ventilation diffuser (1) according to any previous claim characterized in that the diffuser plate (3) is attached to the plenum box (2) by one single resilient element (7).

6. An air ventilation diffuser (1) according to any previous claim characterized in that the diffuser plate (3) is attached to the plenum box (2) only by resilient elements (7) such that the diffuser plate (3) may be completely detached from the plenum box (2) by extending the resilient elements.

7. An air ventilation diffuser (1) according to any previous claim characterized in that the resilient element or elements (7) is pulling the diffuser plate (3) towards the ventilation air outlet (5) with a force of between 5 and 200 Newton (is this a reasonable interval), preferably between 10 and 100 newton and most preferably between 15 and 50 newton when the diffuser plate (3) is positioned in its first, operative position.

8. An air ventilation diffuser (1) according to any previous claim characterized in that the diffuser plate (3) is covering an ventilation air outlet(5) having an area of 0,005 to 2,00 square meter, preferably between 0,01 to 1,50 square meter and most preferably between 0,025 and 1,00 square meter.

9. An air ventilation diffuser (1) according to any previous claim characterized in that the resilient element (1) is fixedly attached to at least one first point in the plenum box (2) and fixedly attached to at least another point on the diffuser plate (3).

10. An air ventilation diffuser (1) according to any previous claim characterized in that said resilient element (7) has an elongated shape and being resilient in its longitudinal direction.

11. An air ventilation diffuser (1) according to any previous claim characterized in that said resilient element (7) is located inside the plenum box (2).

12. An air ventilation diffuser (1) according to any previous claim characterized in that said ventilation outlet (5) from the plenum box (2) has an essentially circular cross sectional area and said diffuser plate (3) has the shape of a circular disc.

13. An air ventilation diffuser (1) according to any previous claim characterized in that the edges of the diffuser plate (3) and the ventilation air outlet (5) has been adapted to fit each other, e.g. by designing all or portions of the rim of the diffuser plate (3) to surround and make a close fit with the rim of the ventilation air outlet (5).

14. An air ventilation system (102) for a building (101), said air ventilation system comprising an air ducting system (103) for distribution of ventilation air in the building (101) which is connected to an air handling unit (104) for producing an air flow in the air ducting system (103),
characterized in that
said air ducting system (103) comprises a ventilation air diffuser (1) according to any of claims 1-13 mounted in or adjacent to the ceiling of the building (101).

Drawing