AU2013200598B2 - Connector for Air-Conditioning Duct - Google Patents

Abstract

Abstract A connector 80 for connecting a duct to a fitting of the kind used in ducted 5 air-conditioning and ventilation systems is described. The connector 80 comprises a spigot 84 for attaching the connector 80 to a duct. A collar 86 is provided on a front edge of the connector 80 for connecting the connector to a fitting. A plurality of clips 88 is provided on the collar 86 that can move from a locked position to a released position wherein, in use, when the collar 86 is 10 brought into connection with the fitting and the clips return to the locked position a substantially air-tight connection is formed between the collar and the fitting. 15 Drawing suggested to accompany the Abstract: Figure 15 ~lot 0t ence 1cl

Description

ORIGINAL AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION Invention title: "CONNECTOR FOR AIR-CONDITIONING DUCT" Applicant: AIRSTREAM COMPONENTS PTY LTD Associated Provisional Application Nos.: 2012901472 and 2012903699 The following statement is a full description of the invention, including the best method of performing it known to me: 2 "CONNECTOR FOR AIR-CONDITIONING DUCT" Field of the Invention The present invention relates to a connector for connecting a duct to a fitting 5 of the kind used in ducted air-conditioning and ventilation systems and relates particularly, though not exclusively, to such a connector for connecting flexible duct to a fitting made from duct board. Background to the Invention 10 Ducted air-conditioning and ventilation systems typically employ flexible duct for transporting the air through the roof space to the various outlets, via air network terminals, adaptors, zone dampers, air diffusers and other fittings. Many fittings located in the roof space are typically made from duct board, which is polyurethane or phenolic board sandwiched between two thin layers 15 of aluminium. The duct board is typically about 20mm thick and the thin layers of aluminium are only about 80pm thick. Duct board has excellent thermal and sound insulation properties and is lightweight compared to other ducting materials. The traditional method of connecting spigots (for the attachment of flexible 20 duct) to duct board fittings is to manufacture a sheet-metal spigot and then with the aid of glues and silicone the spigot is fastened to the duct board. This method is time-consuming and expensive and necessitates the installer fixing the flexible duct to the spigot in situ which is usually in a hot and uncomfortable roof space. 25 In order to overcome some of the problems associated with the traditional method, some ducting systems have plastic fittings and utilise plastic collars to clip onto the fittings using static clips or screws. However the plastic fittings typically supplied with these prior art systems have much inferior insulation properties compared to duct board. In addition the plastic fittings do not seal 30 properly and considerable conditioned air is lost via leakage.

3 Dura-Tite Systems, LLC in the USA have developed a plastic spigot that uses ratchet/cable tie type clips to fasten the spigots to duct board. US 7,338,095 describes the plastic duct connectors manufactured by Dura-Tite Systems, LLC, which comprise an annular cylindrical portion with flange 5 extending radially outwardly from the outer surface of the annular cylindrical portion. A retention means in the form of a plurality of zip ties is mounted in the flange in a corresponding plurality of sleeves, and is engageable in a mouth of a duct board fitting to which the connector is secured. However there are a number of disadvantages of the Dura-Tite system. 10 Connecting flexible duct to the Dura-Tite connector is extremely difficult as the duct tape used to fasten the flexible duct to the collar tends to hinder or interfere with the zip ties. The sleeves through which the Dura-Tite zip ties pass to the outside of the flange are also an area prone to air leaks. Furthermore, once installed the Dura-Tite connector cannot be reused. 15 The present invention was developed with a view to providing a connector which an installer can easily connect to a flexible duct outside the roof space and which can then be simply clipped into the fitting in the roof space, instantly providing a secure and airtight assembly. References to prior art in this specification are provided for illustrative 20 purposes only and are not to be taken as an admission that such prior art is part of the common general knowledge in Australia or elsewhere. Summary of the Invention 25 According to one aspect of the present invention there is provided a connector for connecting a duct to a fitting of the kind used in ducted air conditioning and ventilation systems, the connector comprising: a spigot for attaching the connector to a duct; 4 a collar provided on a front edge of the connector for connecting the connector to a fitting; and, a clip provided on the collar wherein each clip is of resilient construction so that it can bend to a released position and then automatically return to a 5 locked position wherein, in use, when the collar is brought into connection with the fitting and the clip returns to the locked position a substantially air tight connection is formed between the collar and the fitting, and wherein the body of the clip has a curved profile of decreasing thickness when viewed in side view to give the clip the required degree of flex so that it can move from 10 a locked position to a released position. Preferably the clip is one of a plurality of clips provided at spaced intervals around the circumference of the collar. Typically the clips are provided on an internal surface of the collar within the air stream. Advantageously each clip is removably mounted on the internal surface of the collar. Advantageously 15 the resilient clip is normally in the locked position so that when the collar is brought into connection with the fitting it bends inwards to the released position and then returns rapidly to the locked position with a snap-action. Preferably a plurality of clip holders is provided on an internal surface of the connector. Preferably each clip holder is in the form of an open sleeve within 20 which a portion of the clip is slidably received. Preferably each clip is of elongate construction and comprises a body, a head and a pair of legs. Preferably each leg has a foot provided at its lower extremity. Advantageously the length of the legs is designed to match the length of the clip holder sleeves. Preferably the legs correspond to the portion of the clip 25 which is slidably received in the sleeve by slightly squeezing the legs together and pushing the legs into the sleeve until the feet emerge through the other end of the sleeve. Advantageously the legs then return to their normal position and the feet catch on a lower edge of the sleeve to lock the clip in the sleeve. 30 Preferably the head of the clip is latch-shaped and is designed to overhang the top edge of the collar in the locked position.

5 Preferably the collar further comprises a flange extending perpendicularly from an outer surface of the connector and adapted to engage with a wall of the fitting when the collar is brought into connection with the fitting. Preferably when the resilient clip moves to the locked position it holds the flange against 5 the wall of the fitting to from the substantially air-tight connection. Preferably the flange is provided with a strip of resilient sealing material to enhance the air-tight connection. Throughout the specification, unless the context requires otherwise, the word 10 "comprise" or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers. Likewise the word "preferably" or variations such as "preferred", will be understood to imply that a stated integer or group of integers is desirable but not essential to the 15 working of the invention. Brief Description of the Drawings The nature of the invention will be better understood from the following 20 detailed description of several specific embodiments of a connector, given by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a top perspective view of a first embodiment of a connector according to the present invention; Figure 2 is a side elevation of the connector of Figure 1; 25 Figure 3 is a bottom perspective view of the connector of Figure 1; Figure 4 illustrates how the connector of Figure 1 can be used to connect a duct to a duct board fitting; Figures 5 and 6 are a series of schematic views of a spring-loaded clip employed in the connector of Figure 1 showing the movement of the clip 6 between a released position and a locked position; Figure 7 is a top perspective view of a second embodiment of a connector according to the present invention; Figure 8 shows the connector of Figure 7 with a pair of first planar wall 5 extension components fitted thereto; Figure 9 shows the connector of Figure 7 with a pair of second planar wall extension components fitted thereto; Figures 10, 11 and 12 show the connector of Figure 7 with a variety of other planar wall extension components fitted thereto; 10 Figure 13 shows a plurality of the planar wall extension components in top perspective view; Figure 14 illustrates in top plan view a range of low-profile connectors according to a third embodiment of the present invention; Figure 15 is a top perspective view of a fourth embodiment of a 15 connector according to the present invention; Figure 16 is a top perspective view of the connector of Figure 15 showing how the connector can be connected to a duct board fitting; Figure 17 is a top perspective view of the connector of Figure 15 with two of the clips removed; 20 Figures 18 (a), (b), (c), (d) and (e) are a rear plan view, a side elevation, a top plan view, a rear perspective view, and a front perspective view respectively of a removable clip used in the connector of Figure 15; Figure 19 is a top perspective view of a fifth embodiment of a connector according to the present invention; and, 25 Figure 20 is a side elevation of the connector of Figure 19.

7 Detailed Description of Preferred Embodiments A first embodiment of a connector 10 in accordance with the invention, as illustrated in Figures 1 to 4, for connecting a duct 12 (see Figure 4) to a fitting 14 of the kind used in ducted air-conditioning and ventilation systems, 5 comprises a spigot 16 for attaching the connector to the duct 12. A collar 18 is provided on a front edge of the connector 10 for connecting the connector to the fitting 14. A spring-loaded clip 20 is provided on the collar 18 and moves between a released position and a locked position wherein, in use, when the collar 18 is brought into connection with the fitting 14 and the 10 spring-loaded clip 20 is moved to the locked position a substantially air-tight connection is formed between the collar and the fitting. Preferably the spring-loaded clip 20 is one of a plurality of clips 20a, 20b, 20c and 20d provided at spaced intervals around the periphery of the collar 18. Typically the spring-loaded clips 20 are provided on an internal surface of the 15 connector 10 within the air stream. Preferably each spring-loaded clip 20 is pivotally mounted so as to pivot between the released position and the locked position. Advantageously each spring-loaded clip 20 is loaded by a spring 22 in the released position so that when it is triggered it pivots rapidly to the locked position with a snap-action. Typically each spring-loaded clip 20 20 is provided with two springs 22a and 22b to increase the speed and force of the snap-action. Only one of the spring-loaded clips 20a is shown in Figure 1 with the springs 22 fitted, for clarity. The springs 22 of this embodiment are coil-springs. Preferably the collar 18 further comprises a flange 24 extending 25 perpendicularly from an outer surface of the connector 10 and adapted to engage with a wall 26 of the fitting 14 when the collar 18 is brought into connection with the fitting 14, as shown in Figure 4. Preferably when each spring-loaded clip 20 is moved to the locked position it presses the flange 24 against the wall 26 of the fitting 14 to form the substantially air-tight 30 connection. Preferably the flange 24 is provided with a strip of resilient sealing material 28 to enhance the air-tight connection (see Figure 4).

8 Preferably the spigot 16 is formed with a taper and has a plurality of ribs 25 about its circumference to enable the spigot 16 to be inserted into the end of the duct 12 and attached more securely to the duct. Preferably the spring-loaded clip 20 has a latch portion 30 for engaging with 5 the fitting 14 in the locked position and a trigger portion 32 for engaging with the fitting 14 in the released position, wherein when the trigger portion 32 engages with the fitting 14 it triggers the pivoting movement of the clip 20 from the released position to the locked position. Preferably the latch portion 30 is also provided with a plurality of teeth 34 adapted to bite into a surface of 10 the fitting when the spring-loaded clip 20 moves to the locked position. As can be seen most clearly on spring-loaded clip 20b in Figures 1 and 2, which shows the clip 20b in the released position, the trigger portion 32 comprises two feet which extend outwards over the edge of the collar 18 above flange 24. When the collar 18 is brought into close proximity to an 15 opening in the wall 26 of the fitting 14, the wall of the fitting engages with the feet of the trigger portion 32 causing the spring-loaded clip to begin to pivot away from the released position. Each of clips 20a, 20d and 20c are shown in various positions intermediate the released position and the locked position in Figures 1 to 3. 20 The latch portion 30 is provided with a first pair of lugs 36 to which the one end of the respective springs 22a and 22b are attached. The other end of the respective springs 22a and 22b are attached to a second pair of lugs 38 respectively supported on a pair of support brackets 40 provided on an internal surface of the spigot 16. Each spring-loaded clip 20 is itself pivotally 25 supported on a support cradle 42, which comprises two arms, also provided on the internal surface of the spigot 16 between the respective support brackets 40. A spindle 44 is provided on each spring-loaded clip 20, between the feet of the trigger portion 32 (see clip 20a), on which the clip 20 pivots when it is supported on its respective support cradle 42. 30 Figures 5 and 6 illustrate the movement of the spring-loaded clip 20 from a released position to a locked position under the force of springs 22. The 9 positions of the lugs 36 and 38 relative to the position in which the spindle 44 is supported on the cradle 42 are carefully chosen so that when the spring loaded clip is in the released position, the line of force of springs 22 is just inside the over-centre position. The springs 22 thus hold the clip in the 5 released position until it is triggered, as shown in Figures 5(a) and 6(a). However when the trigger portion 32 of the clip engages with a wall 26 of the fitting it causes the clip 20 to begin to pivot towards the over-centre position as shown in Figures 5(b) and 6(b). Once the spring-loaded clip 20 passes the over-centre position, as shown in Figures 5(c) and 6(c), the force of the 10 springs 22 will cause the clip to move rapidly to the locked position, as shown in Figures 5(h) and 6(g), with a snap- action. Figure 5 shows the wall 26 of the fitting made from 1mm thick duct board panel, whereas Figure 6 shows the wall 26 of the fitting made from 20mm thick duct board panel. In either case the spring-loaded clips 20 ensure that 15 the connector 10 is securely locked to the fitting. Even in situations where one of clips 20 is unable to pivot all the way down to the locked position, the teeth 34 on the latch portion will bite into the wall of the fitting and help to ensure the connector 10 remains securely locked to the fitting. Figure 4 shows the connector 10 when it is fully inserted into an opening on a 20 wall 26 of a fitting 14. All four spring-loaded clips 20 are pivoted to their locked position under the force of the springs 22 (not visible). Figures 7 to 12 illustrate a second embodiment of the connector 50 for connecting a duct 12 to a fitting of the kind used in ducted air-conditioning and ventilation systems. The connector 50 is in many respects similar to the 25 connector 10, and therefore the similar parts will be identified with the same reference numerals and will not be described again in detail. The connector 50 comprises a spigot 16 for attaching the connector to a duct 12, and a collar 18 provided on a front edge of the spigot 16 for connecting the connector 50 to a fitting 14. Importantly however, the connector 50 of this 30 embodiment is formed from at least two components 50a and 50b which 10 when joined together form a continuous spigot and collar of the required shape and size. In Figure 7, the two components 50a and 50b are of substantially semi cylindrical shape which when joined together form a continuous cylindrical 5 spigot and collar of circular cross-section, similar to the connector 10 of Figure 1. Advantageously additional planar wall extension components 52 can be fitted between the semi-cylindrical shaped components 50 to form a connector of oval cross-sectional shape, as shown in Figure 8 and described in more detail below. 10 Advantageously each of the components of the connector 50 are joined together by an interlocking arrangement comprising a wedge piece 60 that is slidably received in a matching recess 62 formed at a join between at least two of the components. In Figure 7 there are two wedge pieces 60 used for joining the two semi-cylindrical shaped components 50a and 50b together. 15 One of the wedge pieces 60 is shown prior to insertion into the matching recess 62a, whereas the other wedge piece is shown fully inserted into the other matching recess 62b. As can be seen most clearly in Figure 7, the wedge piece 60 is tapered in two directions and the matching recess 62 is likewise tapered to receive the 20 wedge piece in a tight friction-fit. Advantageously the wedge piece 60 has first and second tongues 64a and 64b provided along respective edges of the wedge piece 60, extending substantially in the direction in which the wedge piece is inserted into the matching recess 62 and protruding substantially perpendicularly from one face of the wedge piece. The tongues 64 engage 25 with matching grooves 66a and 66b provided in the recess so as to hold the at least two components tightly together at the join. The first matching groove 66a is provided in the half of the recess formed in the first component 50a, whereas the second matching groove 66b is provided in the half of the recess formed in the second component 50b. 30 Preferably the wedge piece 60 also has third and fourth tongues 68a and 68b extending substantially in the direction in which the wedge piece 60 is 11 inserted into the matching recess and protruding substantially perpendicularly from the opposite face of the wedge piece 60. The third and fourth tongues 68a and 68b also engage with matching grooves provided in the recesses 62 so as to further aid in holding the at least two components tightly together at 5 the join. Preferably a plurality of spring-loaded clips 20 are provided on the collar 18, similar to that of the connector 10. Each of the clips 20 moves between a released position and a locked position wherein, in use, when the collar is brought into connection with the fitting and the spring-loaded clips 20 all 10 move to the locked position a substantially air-tight connection is formed between the collar 16 and the fitting 14. The spring-loaded clips are similar in design and function to that of the connector 10 and will not be described again here. As noted above, by inserting additional planar wall extension components 15 between the semi-cylindrical shaped components 50a and 50b a connector of oval cross-sectional shape can be formed, as shown in Figure 8. A first planar wall extension component 52 is illustrated in Figure 13, together with a range of other planar wall extension components 53 to 56. It will be seen that each planar wall extension component is of different length depending on the 20 size and shape of the connector 50 it is desired to form. Each planar wall extension component is formed with a flange extension for extending the flange 24 around the full circumference of the collar 18 of the connector 50. One or more additional spring-loaded clips 20 may also be provided on the planar wall extension components to provide additional means of securing 25 the connector to the fitting. The planar wall extension components are joined to the semi-cylindrical shaped components 50a and 50b in the same way as the semi-cylindrical shaped components 50a and 50b are joined together in the configuration of Figure 7. That is, a wedge piece 60 is slidably received in a matching recess 30 62 formed at a join between the components.

12 Figures 9, 10 and 11 illustrate different sized connectors 50 formed by inserting a selected pair of the planar wall extension components 53 to 56 between the semi-cylindrical shaped components 50a and 50b, which remain the same in each case. Figure 12 illustrates a variation of the planar wall 5 extension components employed in the connector of Figure 11. In this case, the planar wall extension component 57 has added depth on the flange extension to provide additional stiffening for the planar walls of the connector. An important advantage of the modular construction of the connector 50 is that the semi-cylindrical shaped components and the planar wall extension 10 components can be more easily packed and transported than the connector 10 manufactured as a single component. There will be less empty space between the modular components and hence more efficient use of the packing space. In addition, the modular construction of the connector 50 allows a low profile connector to be more easily formed with the desired 15 volume capacity. In many ceiling spaces there is insufficient space to accommodate a duct of circular cross-section and therefore low profile ducts of oval cross-section are employed. Figure 14 shows a range of low profile connectors 70 of modular construction, similar to the connector 50 of Figures 7 to 12. In this 20 embodiment, the semi-cylindrical shaped components of each connector 70 are of reduced diameter and therefore only one centrally located spring loaded clip 20 is provided on each semi-cylindrical shaped modular component of the connectors 70. However the planar wall extension components of the connectors 70 are identical to, and are interchangeable 25 with, the planar wall extension components of the connector 50. A fourth embodiment of a connector 80 for connecting a duct (not shown) to a fitting 82 (see Figure 16) of the kind used in ducted air-conditioning and ventilation systems, is illustrated in Figures 15 to 18. The connector 80 comprises a spigot 84 for attaching the connector 80 to a duct and a collar 86 30 provided on a front edge of the connector 80 for connecting the connector to a fitting 82. A clip 88 is provided on the collar 86 that can move from a locked 13 position to a released position wherein, in use, when the collar 86 is brought into connection with the fitting 82 and the clip 88 returns to the locked position a substantially air-tight connection is formed between the collar and the fitting. 5 Preferably the clip 88 is one of a plurality of clips 88 provided at spaced intervals around the circumference of the collar 86. In this embodiment, four clips 88 are provided around the circumference of the collar. Typically the clips are provided on an internal surface of the collar 86 within the air stream. Advantageously each clip 88 is removably mounted on the internal surface of 10 the collar 86. For this purpose, a plurality of clip holders 90 is provided on the internal surface of the spigot 84. Each clip holder 90 is this embodiment is in the form of an open sleeve 90 within which a portion of the clip 88 is slidably received. Each clip 88 is preferably of elongate construction and typically comprises a 15 body 92, a head 94 and a pair of legs 96, as can be seen most clearly in Figures 18 (a) to (e). Preferably each leg 96 has a foot 98 provided at its lower extremity. Preferably the clips 88 are manufactured of injection moulded plastics material. The length of the legs 96 is designed to match the length of the clip holder sleeves 90 on the internal surface of the spigot 84. 20 The legs 96 correspond to the portion of the clip 88 which is slidably received in the sleeve 90. This portion of the clip 88 can be inserted into the sleeve 90 by slightly squeezing the legs 96 together and pushing the legs into the sleeve until the feet 98 emerge through the other end of the sleeve 90. The legs 96 than return to their normal position and the feet 98 catch on a lower 25 edge of the sleeve 90 to lock the clip 88 in the sleeve. Preferably each clip 88 is of resilient construction so that it can bend to the released position and then automatically return to the locked position. The head 94 of the clip 88 is latch-shaped and is designed to overhang the top edge of the collar 86 in the locked position. Preferably the body 92 of the clip 30 88 has a curved profile of decreasing thickness when viewed in side view, as can be seen most clearly in Figure 18 (b). This curved profile of the body 92 14 helps to give the clip 88 the required degree of flex so that it can move from a locked position to a released position. Advantageously the resilient clip 88 is normally in the locked position so that when the collar 86 is brought into connection with the fitting 82 it bends inwards to the released position and 5 then returns rapidly to the locked position with a snap-action. Preferably the collar 86 further comprises a flange 100 extending perpendicularly from an outer surface of the connector 80 and adapted to engage with a wall 102 of the fitting 82 when the collar is brought into connection with the fitting (see Figure 16). Preferably when the resilient clip 10 88 moves to the locked position the head 94 grips the edge of the wall 102 and holds the flange 100 against the wall 102 of the fitting to from the substantially air-tight connection. Preferably the flange 100 is provided with a strip of resilient sealing material 104 to enhance the air-tight connection. Advantageously the latch-shaped head 94 of the clip 99 is provided with a 15 series of teeth 106, as can be seen most clearly in Figure 18 (e), which aid in gripping the edge of the wall 102 of the fitting 82. The clips 88 can be readily modified during manufacture to suit the wall thickness of different fittings, simply by changing the length of the body 92 of the clip. If the clip 88 still does not securely grip the edge of the wall 102 of 20 the fitting 82, then a hole can drilled from the outside through the flange 100 of the collar 86 and the wall 102 of the fitting, and into the head 94 of the clip 88 in situ. A screw (not shown) can then be inserted through the hole and screwed into the head 94 to secure the clip 88 to the edge of the wall 102. The connector 80 is in many respects similar to the modular connector 50 of 25 Figures 7 to 12, and therefore the similar parts will be identified with the same reference numerals and will not be described again in detail. As with the connector 50, the modular connector 80 of this embodiment is also formed from at least two components 80a and 80b which when joined together form a continuous spigot and collar of the required shape and size. 30 In Figures 15 to 17, the two components 80a and 80b are of substantially semi-cylindrical shape which when joined together can form a continuous 15 cylindrical spigot and collar of circular cross-section, similar to the connector 10 of Figure 1 and connector 50 of Figure 7. Advantageously additional planar wall extension components 52 are fitted between the semi-cylindrical shaped components 80a and 80b to form the connector 80 of oval cross 5 sectional shape, as shown in Figure 15 to 17. Advantageously each of the components of the modular connector 80 are joined together by an interlocking arrangement comprising a wedge piece 60 that is slidably received in a matching recess 62 formed at a join between at least two of the components. A variety of planar wall extension components, 10 similar to the wall extension components 52 and 53 illustrated in Figure 13, may be used to from different sized connectors 80, formed by inserting a selected pair of the planar wall extension components between the semi cylindrical shaped components 80a and 80b, which remain the same in each case. 15 A fifth embodiment of a connector 110 for connecting a duct (not shown) to a fitting of the kind used in ducted air-conditioning and ventilation systems, is illustrated in Figures 19 and 20. The connector is in the form of an in-line, motorised damper 110 having a circular plate 112 which can be pivoted between an open and a closed position by an electric motor 114. The damper 20 110 comprises a spigot 120 for attaching the damper 110 to a duct and a collar 122 provided on a front edge of the damper 110 for connecting the connector to a fitting (not shown). A clip 124 is provided on the collar 122 that can move from a locked position to a released position wherein, in use, when the collar 122 is brought into connection with the fitting and the clip 124 25 returns to the locked position a substantially air-tight connection is formed between the collar and the fitting. The clip 124 is similar to clip 88 of Figure 18 and will not be described again in detail. Preferably the clip 124 is one of a plurality of clips 124 provided at spaced intervals around the circumference of the collar 122. In this 30 embodiment, four clips 124 are provided around the circumference of the collar. Typically the clips are provided on an internal surface of the collar 124 16 within the air stream. Advantageously each clip 124 is removably mounted on the internal surface of the collar 122. For this purpose, a plurality of clip holders 126 is provided on an internal surface of the damper 110. As with clip holders 90 of the previous embodiment, each clip holder 126 is this 5 embodiment is in the form of an open sleeve 126 within which a portion of the clip 124 is slidably received. Preferably each clip 124 is of resilient construction so that it can bend to the released position and then automatically return to the locked position. The head of each clip 124 is latch-shaped and is designed to overhang the top 10 edge of the collar 122 in the locked position. Preferably the resilient clips 124 are normally in the locked position so that when the collar 122 is brought into connection with the fitting the clips 124 bends inwards to the released position and then return rapidly to the locked position with a snap-action. Preferably the collar 122 further comprises a flange 128 extending 15 perpendicularly from an outer surface of the damper 110 and adapted to engage with a wall of the fitting when the collar 122 is brought into connection with the fitting. Preferably when each of the resilient clips 124 move to the locked position, the heads grip the edge of the fitting wall and hold the flange 128 against the wall of the fitting to from the substantially air 20 tight connection. Preferably the flange 128 is provided with a strip of resilient sealing material to enhance the air-tight connection. Advantageously the latch-shaped heads of the clips 124 are provided with a series of teeth 130, as can be seen most clearly in Figure 20, which aid in gripping the edge of the wall of the fitting. 25 Now that several embodiments of the connector for connecting a duct to a fitting of the kind used in ducted air-conditioning and ventilation systems have been described in detail, it will be apparent that the described embodiments provide a number of advantages over the prior art, including the following: 17 (i) They provide a much more convenient method of connecting the duct to a fitting which enables the duct to be connected to the connector outside the roof space, and then be connected to the fitting with a snap-connection. 5 (ii) They are easy to use and require no special tools or equipment to connect to a duct. The connector can be joined to a duct using duct tape in a conventional manner. (iii) They are particularly suited to fittings made from duct board, but have wider application to other types of fittings. 10 (iv) The modular form of the connectors provides additional benefits in improved efficiencies in packing and transport of the modular components. (v)The modular form of the connectors also allows low profile connectors of various shapes and sizes to be more easily made. 15 It will be readily apparent to persons skilled in the relevant arts that various 20 modifications and improvements may be made to the foregoing embodiments, in addition to those already described, without departing from the basic inventive concepts of the present invention. For example, the type of clip employed on the connectors may vary considerably from that shown in the illustrated embodiments. Therefore, it will be appreciated that the scope 25 of the invention is not limited to the specific embodiments described.

Claims (16)

1. A connector for connecting a duct to a fitting of the kind used in ducted air conditioning and ventilation systems, the connector comprising: 5 a spigot for attaching the connector to a duct; a collar provided on a front edge of the connector for connecting the connector to a fitting; and, a clip provided on the collar wherein each clip is of resilient construction so that it can bend to a released position and then automatically return to a 10 locked position wherein, in use, when the collar is brought into connection with the fitting and the clip returns to the locked position a substantially air tight connection is formed between the collar and the fitting, and wherein the body of the clip has a curved profile of decreasing thickness when viewed in side view to give the clip the required degree of flex so that it can move from 15 a locked position to a released position.

2. A connector for connecting a duct as defined in claim 1, wherein the clip is one of a plurality of clips provided at spaced intervals around the periphery of the collar.

3. A connector for connecting a duct as defined in claim 2, wherein the clips 20 are provided on an internal surface of the collar within the air stream.

4. A connector for connecting a duct as defined in claim 3, wherein each clip is removably mounted on the internal surface of the collar.

5. A connector for connecting a duct as defined in claim 1, wherein the resilient clip is normally in the locked position so that when the collar is 25 brought into connection with the fitting it bends inwards to the released position and then returns rapidly to the locked position with a snap-action.

6. A connector for connecting a duct as defined in any one of the preceding claims, wherein a plurality of clip holders is provided on an internal surface of the connector. 19

7. A connector for connecting a duct as defined in claim 6, wherein each clip holder is in the form of an open sleeve within which a portion of the clip is slidably received.

8. A connector for connecting a duct as defined in claim 7, wherein each clip 5 is of elongate construction and comprises a body, a head and a pair of legs.

9. A connector for connecting a duct as defined in claim 8, wherein each leg has a foot provided at its lower extremity.

10. A connector for connecting a duct as defined in claim 9, wherein the length of the legs is designed to match the length of the clip holder sleeves. 10

11. A connector for connecting a duct as defined in claim 10, wherein the legs correspond to the portion of the clip which is slidably received in the sleeve by slightly squeezing the legs together and pushing the legs into the sleeve until the feet emerge through the other end of the sleeve.

12. A connector for connecting a duct as defined in claim 11, wherein when 15 the feet emerge through the other end of the sleeve the legs return to their normal position and the feet catch on a lower edge of the sleeve to lock the clip in the sleeve.

13. A connector for connecting a duct as defined in claim 12, wherein the head of the clip is latch-shaped and is designed to overhang the top edge of 20 the collar in the locked position.

14. A connector for connecting a duct as defined in any one of the preceding claims, wherein the collar further comprises a flange extending perpendicularly from an outer surface of the connector and adapted to engage with a wall of the fitting when the collar is brought into connection 25 with the fitting.

15. A connector for connecting a duct as defined in claim 14, wherein when the resilient clip moves to the locked position it holds the flange against the wall of the fitting to from the substantially air-tight connection. 20

16. A connector for connecting a duct as defined in claim 15, wherein the flange is provided with a strip of resilient sealing material to enhance the air tight connection. 5 Dated this 23 rd day of December 2014 Airstream Components Pty Ltd by its Patent Attorneys Wrays