WO2011109870A1

WO2011109870A1 - Outlet assembly for a heating, air conditioning or ventilating duct

Info

Publication number: WO2011109870A1
Application number: PCT/AU2011/000271
Authority: WO
Inventors: Danielle Jane Bacon; Simon Luke Bacon
Original assignee: Danielle Jane Bacon; Simon Luke Bacon
Priority date: 2010-03-10
Filing date: 2011-03-10
Publication date: 2011-09-15
Also published as: AU2010257293A1

Abstract

There is disclosed an outlet assembly for a heating, air conditioning or ventilating duct, comprising a grille having a first section which is formed with one or more openings to discharge air and is configured to remain in place when the assembly is in situ, and a second section which is removable to be interchangeable with at least one other second section having a different external appearance therefrom.

Description

OUTLET ASSEMBLY FOR A HEATING, AIR CONDITIONING OR VENTILATING DUCT Field of the Invention

The present invention relates to outlet assemblies, including diffusers, for heating, air conditioning and ventilating ducts. The invention has application in particular to wall- mounted, ceiling-mounted and floor-mounted outlet assemblies/diffusers for residential, office and factory air conditioning/heating systems, though is not limited to such systems.

Background

Parts of the assemblies/diffusers in question which are visible when the assembly/diffuser is in situ, can be somewhat unsightly, particularly in residential or office settings. Moreover, assemblies/diffusers of the type in question are often configured solely for diffusing air from a duct, and it would be desirable to afford them greater functionality. There is a clear need for improvements in such outlet assemblies/diffusers.

Summary of the Invention

According to a first aspect of the present invention, there is provided an outlet assembly for a heating, air conditioning or ventilating duct, the assembly being adapted to receive air which is output from the duct, and comprising a grille and means for adjusting airflow through the grille, wherein the grille comprises a first section which is formed with one or more discharge openings and is configured to remain in place when the assembly is in situ, and a second section which can be relocatably moved when the assembly is in situ to permit access to the airflow adjustment means.

The assembly may be one which couples, directly or indirectly, to the duct, or one which is adapted for mounting separately from the duct but adjacent an outlet thereof.

Preferably, the second section is removable.

In the preferred embodiments of the invention, the second section at least partially conceals the airflow adjustment means. Preferably, the airflow adjustment means comprises a damper mechanism. In a preferred embodiment of the invention, the airflow adjustment means comprises a pair of damper plates having adjacent proximal ends which are arranged to extend across the airflow, each plate being rotatable about its proximal end between an open position, in which it extends generally axially from its proximal end to permit the air to flow therepast, and a closed position, in which it extends laterally outwardly from its proximal end to restrict the air from flowing therepast. The airflow adjustment means may be configured such that the plate(s) in their closed positions substantially prevent airflow therepast. In a preferred embodiment of the invention, the airflow adjustment means comprises at least one hand-operable actuator which is accessible, preferabl through the first section, when the second section has been moved to permit access thereto.

Preferably, the at least one hand-operable actuator is a pair of actuators, each actuator being operably associated with a respective plate of said pair of damper plates. Preferably, each actuator comprises a projection able to be pushed or pulled to rotate the respective plate. Preferably, each projection is pinch-grippable. Preferably, each projection is formed as a tab. Preferably, each projection is supported from the respective plate. Preferably, the damper plates are rotatable about a common axis.

Preferably, the damper plates in said pair of damper plates are mounted at their proximal ends on a single shaft to be rotatable about said common axis. Preferably, the proximal ends are centrally disposed with respect to the second section.

Preferably, the assembly further comprises a duct section which is arranged to be upstream of the grille and which is formed with an inlet to receive the air which is output from the duct. Preferably, the airflow adjustment means comprises at least one damper plate arranged in the duct section.

Preferably, the second section holds an agent for treating the air and is configured such that the agent is released into the airflow.

According to a second aspect of the present invention, there is provided an outlet assembly for a heating, air conditioning or ventilating duct, the assembly being adapted to receive air which is output from the duct, and comprising a grille having a first section which is formed with one or more discharge openings and is configured to remain in place when the assembly is in situ and a second section which is removable when the assembly is in situ, the second section holding an agent for treating the air and being configured such that the agent is released into the air flowing through the assembly.

According to a third aspect of the present invention, there is provided an outlet assembly for a heating, air conditioning or ventilating duct, the assembly being adapted to receive air which is output from the duct, and comprising a grille having a first section which is formed with one or more discharge openings and is configured to remain in place when the assembly is in situ, and a second section which holds an agent for treating the air and is configured such that the agent is released into the air flowing through the assembly, the second section being relocatably movable when the assembly is in situ to permit the second section to be resupplied with agent. Preferably, the second section is removable.

According to a fourth aspect of the present invention, there is provided an outlet assembly for a heating, air conditioning or ventilating duct, comprising a grille adapted to discharge air which is output from the duct, and an agent for treating the air, wherein the agent is held so as to be released into the air as it flows through the assembly, in a manner such that air flow through the grille is substantially unobstructed.

Preferably, the agent is held by the grille. In one embodiment of the invention, the assembly further comprises a damper mechanism which is operable to adjust airflow through the assembly, and the agent, alternatively, is held by a damper plate of the mechanism. In a preferred embodiment of the invention, the grille comprises a first section which is formed with air discharge openings and is configured to remain in place when the assembly is in situ, and a second section which holds the agent, the second section being relocatably movable when the assembly is in situ to permit the second section to be resupplied with agent.

In a preferred embodiment of the invention, the grille comprises a first section which is formed with one or more air discharge openings and is configured to remain in place when the assembly is in situ and a second section which holds the agent and is removable when the assembly is in situ.

Preferably, the second section is formed with at least one air discharge opening.

Preferably, the assembly further comprises a duct section which is arranged to be upstream of the grille and which is formed with an inlet to receive the air which is output from the duct.

The assembly according to the second or third aspect may, in some embodiments of the invention, consist solely of the grille, and may be one which fixes to or couples with the duct. The assembly according to the fourth aspect may, in some embodiments, consist solely of the grille, which may be a single piece, and the agent held to the grille, and may also be one which fixes to or couples with the duct

Preferably, the agent is a scenting, odorising or fragrancing agent. In an embodiment of the invention, the agent evolves a perfumed odour. The agent may evolve an odour which smells of or like that of a food or foodstuff. The agent may evolve an odour which smells of or like that of a fruit or plant, e.g. citrus or vanilla, of or like that of a herb or spice, e.g. cinnamon, or of or like that of a confection, dessert or sweet food, e.g. "cookies and cream".

Alternatively or additionally, the agent may be a deodorising and/or antibacterial agent. In a preferred embodiment of the invention, at least one element holds the agent.

Preferably the or each element is configured as a patch or strip. In a preferred embodiment of the invention, the or each element, preferably being a patch or strip, lies in a plane which is generally aligned with a direction of airflow therepast. In this way, the element may pose little or no obstruction to airflow.

Preferably, the or each element is positioned to extend in general alignment with a said opening.

In a preferred embodiment of the invention, the or each element is applied to the second section. Preferably, the or each element comprises a sticky surface which is received against a surface in the assembly to hold the element in position.

Preferably, agent is carried by a fin, such as a grille fin, or louvre in the assembly.

Preferably, the or each element is removable to be replaceable with a like element. In one embodiment of the invention, the or each element may comprise an adhesive backing to mount the element. In an alternative embodiment of the invention, the or each element comprises a magnetic backing which is receivable against a respective magnetic surface on a part of the assembly to which it is applied to be mounted thereto.

In a preferred embodiment of the invention, the or each element comprises a portion formed of material which is imbued or impregnated with the agent. Preferably, the material is sticky to be held in position. Said material may be rendered adhesive when imbued with the agent. Preferably, the agent is a liquid. The material may be one which absorbs the liquid.

In a preferred embodiment of the invention, the agent is carried by the second section and is configured to be removable such that when removed it can be replenished with agent. In an alternative embodiment of the invention, the second section may be removable when the agent has been consumed and replaceable with another said second section, which is plenished with the agent.

The first section may, in some embodiments of the invention, comprise two subsections of the grille which are spaced apart.

Preferably, the first section is fixed.

Preferably, the second section is releasably snap-fittingly engaged with the remainder of the assembly.

Preferably, exterior faces of the first and second sections lie flush with each other.

Preferably, the assembly is provided as a unitary fitting.

Preferably, the second section is a single piece. Alternatively, the second section may comprise a plurality of separately formed subsections. In a preferred embodiment of the invention, the grille is configured such that, when it is in situ, an exterior face thereof lies substantially flush with the surface of a ceiling or wall. Preferably, a periphery.of the grille is receivable against the surface.

Preferably, the second section is releasable by hand and replaceable in position by hand, i.e. releasable and replaceable without the aid of any implement.

Preferably, the second section is releasably engaged with the first section.

Preferably, the second section is centrally disposed with respect to the first section.

Preferably, the second section is removable to be interchangeable with at least one other second section having a different external appearance therefrom. According to a fifth aspect of the present invention, there is provided a grille or grille fascia for an air outlet, comprising a first section which is formed with one or more openings to discharge air and is configured to remain in place when the assembly is in situ, and a second section which is removable to be interchangeable with at least one other second section having a different external appearance therefrom.

According to a sixth aspect of the present invention, there is provided an assembly, grille or grille fascia as defined above and said other second section(s). According to a seventh aspect of the present invention, there is provided an assembly, grille or grille fascia as defined above according to any one of the first to sixth aspects in situ. Preferably, the assembly, grille or grille fascia is ceiling-mounted.

In the preferred embodiments of the invention, the first section forms most, or a main part, of the grille.

According to an eighth aspect of the present invention, there is provided a said second section. According to a ninth aspect of the present invention, there is provided a grille or grille fascia for an air outlet, comprising an exterior portion which can be seen through and which defines an outer face of the grille or grille fascia, whereby an area which the exterior portion overlies is visible through the outer face to appear as backing to the exterior portion.

Preferably, the exterior portion is transparent. Preferably, the outer face is shiny. Preferably, the exterior portion comprises plastic.

In a preferred embodiment of the invention, the exterior portion comprises a layer or coating, and said area is defined by an outwardly facing surface over which the layer or coating is applied. Preferably, said surface is defined by a backing layer, such as sheeting, or coating, such as paint, applied behind said layer or coating. The backing layer or coating may be applied over a surface of part of the grille structure which the exterior portion overlies.

In an alternative embodiment of the invention, the exterior portion may be defined by a layer or coating within which sheeting defining the backing is submerged. In a preferred embodiment of the invention, the exterior portion is uncoloured and/or untinted.

Preferably, said area is opaque.

The grille or grille fascia of the ninth aspect may define the grille of an assembly as described above.

According to a tenth aspect of the present invention, there is provided a ceiling or wall outlet assembly for a heating, air conditioning or ventilating duct, the assembly being adapted to receive air which is output from the duct, and comprising a grille section and means for adjusting airflow through the assembly, wherein the grille section can be relocatably moved when the assembly is in situ to permit access to the airflow adjustment means.

Preferably, the grille section is formed as a single piece.

In a preferred embodiment of the invention, the assembly comprises a grille defined by the grille section and a further grille section, the further grille section being configured to remain in place when the assembly is in situ. In an alternative embodiment of the invention, the assembly comprises a grille the entirety of which is defined by the grille section.

Preferably, the grille section is removable. In the preferred embodiments of the invention, the grille section at least partially conceals the airflow adjustment means. Preferably, the airflow adjustment means comprises a damper mechanism. In a preferred embodiment of the invention, the airflow adjustment means comprises a pair of damper plates having adjacent proximal ends which are arranged to extend across the airflow, each plate being rotatable about its proximal end between an open position, in which it extends generally axially from its proximal end to permit the air to flow therepast, and a closed position, in which it extends laterally outwardly from its proximal end to restrict the air from flowing therepast. The airflow adjustment means may be configured such that the plate(s) in their closed positions substantially prevent airflow therepast.

In a preferred embodiment of the invention, the airflow adjustment means comprises at least one hand-operable actuator which is accessible when the grille section has been moved to permit access thereto.

Preferably, the at least one hand-operable actuator is a pair of actuators, each actuator being operably associated with a respective plate of said pair of damper plates. Preferably, each actuator comprises a projection able to be pushed or pulled to rotate the respective plate. Preferably, each projection is pinch-grippable. Preferably, each projection is formed as a tab. Preferably, each projection is supported from the respective plate.

Preferably, the damper plates in said pair of damper plates are mounted at their proximal ends on a single shaft to be rotatable about a common axis.

Preferably, the proximal ends are centrally disposed with respect to the second section.

Preferably, the assembly further comprises a duct section which is arranged to be upstream of the grille section and which is formed with an inlet to receive the air which is output from the duct. Preferably, the airflow adjustment means comprises at least one damper plate arranged in the duct section. According to an eleventh aspect of the present invention, there is provided a ceiling or wall outlet assembly as defined above in situ. Preferably, the outlet assembly is ceiling-mounted. Brief Description of the Drawings

The present invention will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:

Figure 1 is an upper perspective view of an outlet assembly for a heating or cooling duct in accordance with a first preferred embodiment of the present invention, in which a damper of the fitting is open;

Figure 2 is a lower perspective view of the assembly, including a removable cover piece thereof;

Figure 3 is a lower perspective view of the assembly of the first embodiment, showing a cover piece of the fitting removed;

Figure 4 is an exploded upper perspective view of the assembly of the first embodiment;

Figure 5 is an upper perspective view of the assembly of the first embodiment, in which the damper is closed;

Figure 6 is a bottom view of the assembly of the first embodiment;

Figure 7 is an upper perspective view of a removable cover piece of the assembly of the first embodiment;

Figure 8 is a top view of the cover piece;

Figure 9 is a bottom view of the cover piece;

Figure 10 is a bottom view of an alternative removable cover piece for the assembly of the first embodiment;

Figure 1 1 is a bottom view of another alternative removable cover piece for the assembly of the first embodiment;

Figure 12 is a lower perspective view of an outlet assemoiy ror a heating or cooling duct in accordance with a second preferred embodiment of the present invention; and

Figure 13 is an upper perspective view of the assembly of the second embodiment. Detailed Description

An outlet fitting 1 for a heating or codling duct in accordance with a first preferred embodiment of the present invention is shown in Figures 1 to 6. Referring to Figures 1 and 2, the fitting 1 comprises an "adaptor" or duct section 3 which is configured to be coupled to an outlet of a heating or cooling duct (not shown), which may be arranged above a building ceiling or behind a building wall, and a grille 5, at an outlet end of the body 3, which is receivable against the ceiling, wall or floor. With reference to Figure 3, the grille 5 comprises a fixed section 6 which forms the majority of the grille 5 and which is formed with a central opening .7 therein (see Fig. 3), and a removable section, in the form of a shield or cover piece 9, which mounted to the fixed section 6 and received in the opening 7, as will be described in further detail later, the sections 6 and 9 each being moulded from opaque plastic. The fitting 1 further comprises a means for adjusting airflow through the fitting 1, which comprises a damper mechanism 20, as will be described in further detail later, the mechanism 20 being accessible through the opening 7 when the cover piece 9 is removed.

The fixed section 6 is formed with a plurality of elongate discharge apertures 8 therethrough, through which air flows from the duct section 3 into the room, the apertures 8 being defined between fins 8A of the formed into the fixed section 6. The removable piece 9, which is generally rectangular, is also formed with elongate apertures 10 therethrough, which also define part of the visible grille pattern and through which air also flows from the duct section 3 into the room. In the removable piece 9, there are two apertures 10, one of which is defined between one of two outer fins 10A of the removable piece 9 and a central rib 15 of the piece 9, and the other of which is defined between the other outer fin 10A and central rib 15. The grille, including the removable piece, may, in other embodiments, be configured in any of a number of forms, such as the form of a lattice or mesh, or a form in which the apertures form concentric shapes, such as rectangles or rings. It will be noted that the fixed section 6 and removable section 9 define, by way of apertures 8 and 10, the discharge opening/aperture pattern/arrangement of the grille 5. Referring to Figures 1, 4 and 5, the duct section 3 is formed with a cylindrical portion 3 A, which is to be fitted to the outlet of the duct, a divergent portion 3B, extending from the cylindrical portion 3A, and a generally square flange portion 3C at an outlet end of the fitting 1. The portions 3A, 3B and 3C are integrally formed as a single moulding. The duct section 3 further comprises four spring-loaded clips 4 adjacent the corners of the flange portion 3C (the springs not being shown). The cylindrical portion 3 A and divergent portion 3B, including clips 4, are receivable through a hole, in the form of a rectangle the corners of which may be rounded, formed in a ceiling or wall, whereby the clips 4 are engageable with a concealed face of the ceiling or wall adjacent the periphery of the opening to hold the flange 3C against the (otherwise) exposed surface of the ceiling or wall and thus generally flush with the ceiling or wall surface.

The grille 5 is held to the flange 3C by adhesive, applied to the fixed part 6, and forms a fascia of the fitting 1. The divergent portion 3B distributes the air flowing out of the cylindrical portion 3 A so that it can be discharged through all of the apertures 8 in the grille 5, in addition to the apertures 10 in the removable piece 9.

As mentioned above, the air flow control mechanism 20 comprises a damper mechanism. The damper mechanism 20, as can best be seen at Figure 4, includes a pair of semi-circular damper plates 24 mounted to a common shaft 26 which extends diametrically through the cylindrical portion 3A, each plate being formed at a proximal end with a pair of spaced apart, coaxial sleeves 25, 27 received over the shaft 26, the sleeves 25, 27 of one plate being arranged at different axial locations from those of the other, whereby both plates 24 are rotatably mounted to the shaft 26.

Formed on each plate 24 is an arm 29 for adjusting the angle of the plate 24. Each arm 29 is formed at a proximal end thereof with an actuator in the form of a tab 31 which extends approximately halfway around the axially inner sleeve 25 of the respective plate 24, and is accessible through the opening 7 when the piece 9 is removed.

Formed on the axially outer sleeve 27 of each plate 24 is a lug 32 which is configured with an axially outward facing hemispherical bump or nodule 34 for locking the respective damper plate 24 in any of a plurality of angular positions, as will be described in further detail below.

Received over each end of the shaft 26 is a respective locking element 36, an axially inward facing surface of which is formed with a plurality of hemispherical depressions 35, of a configuration complementary to that of the nodules 34, arranged in an arc. The elements 36 are provided with holes 38 therethrough into which the respective ends of the shaft 26 are received such that the elements 36 are mounted to the shaft 26. Pins 40 are received through respective holes 42 formed through the wall of cylindrical portion 3A and into open ends of the shaft 26 to mount the shaft 26, and thus the damper mechanism 20, in the cylindrical portion 3 A. A pin 36 is formed on the axially outwardly facing surface of each locking element 36 and received in a respective hole 44 formed through the wall of cylindrical portion 3A to prevent rotation of the locking element 36. A person can adjust the angular position of each plate 24 by inserting their fingers through opening 7, pinching either or each of the tabs 31 , and using it to rotate the respective plate 24 in one direction or the other. As the plate 24 is rotated, the respective nodule 34 is advanced along the arrangement of depressions 35 on the respective abutting locking element 36 to be received in each depression 35 successively. The resilience of the interengagement between the lug 32 and locking element 36 is sufficient to retain the nodule 34 in whichever depression 35 in which it is received, thereby locking the plate 24 angularly until sufficient torque is exerted, via tab 31, to move the plate 24 to another angular position. The cover piece 9 is formed along each longitudinal edge thereof with a pair of spaced apart locking tabs 1 1 each of which is configured with a laterally outwardly projecting lip 12 which, when the cover piece 9 is inserted into opening 7, is snappingly received into a corresponding slot 13 provided in a wall 14 formed on the fixed section 6 which extends around the perimeter of the opening 7. A person can remove removable piece 9 by grasping the central rib 15 separating the two openings 10 and pulling it until the cover piece 9/tabs 11 flex sufficiently to cause the lips 12 to disengage from slots 13. The piece 9 is interchangeable with any of a plurality of other removable pieces, examples of which are illustrated in Figures 10 and 1 1 , the other removable pieces having the same arrangement of locking tabs 1 1 with lips 12 but a different appearance from the removable piece 9 and also each other. One removable piece 9', shown in Figure 10, is of the same shape and configuration as piece 9 but is of a different colour (piece 9 being the same colour as the fixed section 6), whereas the removable piece 9" shown in Figure 1 1 is of the same colour as the fixed section 6 but has a different configuration. The removable pieces may differ not only in colour and configuration, but also, for example, in finish or texture. Because the removable pieces are receivable in the opening 14, they 'at least partially conceal the plate proximal ends and the tabs 31.

Attached to each of two longitudinal faces of the piece 9 is a respective element, in the form of a strip 16 (as can be seen in Figures 4, 7 and 8), comprising an agent for fragrancing, scenting or odorising the air as it flows through the fitting 1, the longitudinal faces in this embodiment being laterally outer faces of outermost ones of the fins 10A. Whilst these faces do not bound apertures 10A, they are nevertheless exposed to the air flowing through the fitting 1, so that the agent is released into the air. In other embodiments, one or more elements/strips could instead be attached to at least one other surface on the fitting. 1 without departure from the invention, e.g. a surface on the or each damper plate 24, which is exposed to the flowing air, but will preferably be attached to grille 5 specifically. For example, a strip 16 could, alternatively or additionally, be attached to one or each of the inclined side faces of the central rib 15 shown in Figure 7 and/or attached to either or each of the side faces of any or all of the fins 8A and 1 OA. The strips 16 may be coloured so as to indicate a fragrance thereof (e.g. yellow for lemon) or transparent so as not to be conspicuous.

The agent may release any of a wide range of odours. It may release odour which smells of or like that of a food or foodstuff. It may release an odour which smells of or like that of a fruit or plant, e.g. citrus or vanilla, of or like that of a herb or spice, e.g. cinnamon, or of or like that of a confection, dessert or sweet food, e.g. cookies and cream. The agent may, alternatively or additionally, comprise a deodorising and/or antibacterial substance to treat the air.

Each strip 16 includes a substrate or backing one surface of which is sticky and is received against the respective removable piece wall surface to hold the strip 16 to the removable piece. In the present embodiment, the agent is provided in the form of a gel or silicone-like substance which is applied to the other surface of the substrate/backing.

The longitudinal faces are arranged such that, when the piece 9 is mounted, they are spaced from the adjacent walls in the fixed part 6 in which the slots 13 are formed, so that the strips 16 are exposed to the air flow. The strip 16 releases the agent into the air flowing through the fitting 1 , and can be peeled off and replaced with a fresh strip or replenished with more agent when the agent is finished. Though not visible in the drawings, corresponding strips 16 are provided on the alternative cover pieces 9' and 9". Alternatively, or additionally, a strip 16 can be provided on the inclined inner face of one or both of fins 10A and/or one or both of the inclined side faces of the central rib 15 of piece 9', and, likewise, can be provided on the inclined inner face of one or both fins 1 OA and/or one or both of the inclined side faces of either or both of the two central/inner ribs 15 of the piece 9".

In other embodiments, the or each element may be provided as a patch, rather than a strip.

In another embodiment, the element may comprise a tablet formed from the agent. Also in another embodiment, each strip 16 may instead have a magnetic backing, which is received against a magnetic surface, such as a metal strip, provided on the cover piece 9, to mount the strip 16 removably to the cover piece 9.

In yet a further embodiment, the element may comprise a portion formed of material which is imbued or impregnated with, and/or which absorbs, the agent, and which is sticky so to be received directly against a surface of the grille/cover piece to hold the element to the removable piece/shield. The material may be rendered adhesive when imbued with the agent, which agent may comprise a liquid.

Advantageously, the element(s) in each embodiment are configured and positioned so as not to obstruct airflow through the fitting, particularly the grille.

A grille 5' of a second embodiment of the present invention is shown in Figures 12 and 13. The grille 5' may form part of a fitting 1 according to the first embodiment or instead be provided as a separate assembly for mounting at or adjacent an outlet of a heating, air conditioning or ventilating duct, and thus constitute an outlet assembly in its own right.

The grille 5' is substantially identical in shape and configuration to the grille 5 (whereby it may substitute for the grille 5 in the fitting 1), comprising fixed section 6 and removable section 9, except that it further comprises an exterior moulded plastic layer 2 which is transparent and which defines a shiny or partially reflective exterior face 2 A of the grille 5', whereby the outer surfaces of the fixed and removable sections which the layer 2 overlies, which surfaces may be defined by backing sheeting or paint applied to parts of the fixed and removable section structures, are visible through the face 2A, defining an opaque backing 2B. The combination of the transparent layer 2 and opaque backing 2B afford the grille 5' an aesthetically pleasing appearance similar to that created by applying a backing, such as a coat of paint, to a pane of glass, e.g. in the manufacture of a splashback for a kitchen or bathroom.

The layer 2, in other embodiments, need not be transparent, provided it can be seen through sufficiently for the backing 2B to be discernible; for example, the layer 2 may be translucent.

It is also envisaged that, in other embodiments, the exterior layer could be defined by a coating applied post-moulding, the coating being sufficiently thick that the backing is discernibly behind the outer face, or could be replaced with an exterior portion defined by a layer or coating within which sheeting defining the backing is submerged. While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not by way of limitation. It will be apparent to a person skilled in the relevant art that various changes in form and detail can be made therein without departing from the spirit and scope of the invention. Thus, the present invention should not be limited by any of the above described exemplary embodiments.

Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

Claims

1. An outlet assembly for a heating, air conditioning or ventilating duct, comprising a grille having a first section which is formed with one or more openings to discharge air and is configured to remain in place when the assembly is in situ, and a second section ^"which is removable to be interchangeable with at least one other second section having a different external appearance therefrom.

2. An assembly according to claim 1 , being a unitary fitting.

3. An assembly according to claim 1 or 2, wherein the second section is releasably snap-fittingly engaged with the remainder of the assembly.

4. An assembly according to any one of the preceding claims, wherein the second section is releasable by hand and replaceable in position by hand.

5. An assembly according to any one the preceding claims, wherein the second section is centrally disposed with respect to the first section..

6. An assembly according to any one of the preceding claims, wherein the second section is a single piece.

7. An assembly according to any one of the preceding claims, wherein the first section forms a main part of the grille.

8. An assembly according to any one of the preceding claims, wherein the second section is formed with at least one said discharge opening.

9. An assembly according to any one of the preceding claims, wherein the second section holds an agent for treating the air and is configured such that the agent is released into the airflow.

10. An assembly according to claim 9, wherein at least one element holds the agent, the or each element being configured as a patch or strip which lies in a plane which is generally aligned with a direction of airflow therepast.

1 1. An assembly according to any one of the preceding claims, comprising an exterior portion which can be seen through and which defines an outer face of the grille, whereby an area which the exterior portion overlies is visible through the outer face to appear as backing to the exterior portion.

12. An assembly according to any one of the preceding claims, consisting solely of said grille.

13. An assembly according to any one of claims 1 to 1 1, being adapted to receive air which is output from the duct and further comprising means for adjusting airflow through the grille.

14. An assembly according to claim 13, wherein the airflow adjustment means comprises a pair of damper plates having adjacent proximal ends which are arranged to extend across the airflow, each plate being rotatable about its proximal end between ari open position, in which it extends generally axially from its proximal end to permit the air to flow therepast, and a closed position, in which it extends laterally outwardly from its proximal end to restrict the air from flowing therepast, and wherein the damper plates in said pair of damper plates are rotatable about a common axis and the proximal ends are centrally disposed with respect to the second section

15. In combination, the assembly according to any one of the preceding claims and said other second section(s).