AU698481B2 - Duct joiner and retaining clip therefor - Google Patents

Description

-1I- P10010011I Regulation 3.2

AUSTRALIA,

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

Name of Applicant: Actual Inventor: Address for service William -J-Donnelly TLAw.A INVE'S~mewTS /liMr-E William J. Donnelly i' in Austra ia.- CARTER SMITH BEADLE k 113 ,j 2 Railway Parade Camberwell Victoria 3124 ~V Australia Invention Title: Duct Joiner and Retaining Clip Therefor Details of Associated Provisional Application: PM9627 filed 23 November 1994 The following sLitement is a full description of this invention, including the best method of performing it known to us -2- DUCT JOINER AND RETAINING CLIP THEREFOR This invention relates to a means for connecting a duct joiner to a duct so as to provide a continuous air flow path through the duct joiner and duct.

Tubular type air ducts are extensively used in air conditioning systems to provide an air flow path from a main air conditioning plant to the space that requires conditioned air. In air conditioning systems, apart from the large metal major ducts, there are also many smaller ducts leading from the major ducts to the air conditioned space. However these ducts are usually made in fixed lengths or must be branched to lead to different parts of the air conditioned space. It is therefore necessary to have duct joiners, which may be for connecting two lengths of ducts or may be a branch or the like so that two or more ducts can lead from a single duct. Also duct joiners may connect a duct to an air diffuser or grille outlet. A method of connecting the ducts to the duct joiners is required.

Usually the ducts are joined to the duct joiners by placing the ducts over a neck portion of the duct joiners and merely taping the duct to the duct joiner. This form of connection can easily break, is time consuming when installing ducts, and does not provide an effective sealed connection. This last deficiency results in an t ;,,!inefficient air conditioning system since a substantial amount of the conditioned air does not reach the space that requires the air conditioning but is lost through the 20 connections of the duct and duct joiners.

,It is therefore desirable to provide a means for connecting a duct to a duct joiner which overcomes one or more of the disadvantages of known connecting means. It is also desirable to provide a ductjoiner which is relatively cheap and easy to manufacture and use.

According to one aspect of the invention there is provided a retaining clip for connecting a duct joiner to an air duct having an internal wall, the retaining clip being formed of resilient plastics material and having a ring portion adapted to be mounted around a neck of the duct joiner and to be retained thereby, and a plurality of resilient projections extending outwardly from said ring portion at an angle inclined to "d plane perpendicular to the central axis of the ring portion whereby the JRGLR#|6313PS 17 Sqt1e 99l resilient projections are adapted to flex inwardly when an air duct is moved over the joiner, the projections having sherp edges or points which are adapted to dig into the internal wall of a duct to retain the duct on the joiner.

According to another aspect of the invention there is provided a duct joiner for joining to an air duct of hollow form, said duct joiner having at least one neck portion providing an air channel for the passage of air through the duct joiner, wherein a retaining clip formed of resilient plastics minaterial is mounted to said neck portion, said retaining clip having a ring portion extending around said neck portion and a plurality of a resilient projections extending outwardly from said ring portion at an angle inclined to a plane perpendicular to the longitudinal axis of said tubular neck portion whereby the resilient projections flex inwardly when an air duct is moved over the neck portion, the resilient projections having sharp edges or points which are adapted to dig into the internal wall of the duct to restrain movement of the duct away from the joiner.

The ring portion of the retaining clip is preferably of annular form and is received in an annular groove in the outer surface of the neck portion of the joiner with a plurality of resilient teeth or other projections extending outwardly from the ring portion at an angle inclined to a plane perpendicular to the longitudinal axis of i .the neck portion of the duct joiner.

29 A resilient seal means may also be provided for positioning around the neck

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of the duct joiner to seal any gap between the duct joiner and the duct when the duct is mounted over the duct and clip. Preferably, the resilient seal means comprises a soft ring seal received in a groove in the outer surface of the neck portion of the joiner.

The duct joiner may have a single neck portion and an air outlet portion providing an exit channel through which air can flow into a room or the like.

Alternatively, a duct joiner in accordance with the invention may have a plurality of neck portions, each provided with a retaining clip and resilient seal means, for joining one duct to at least one other duct. For instance, a duct joiner may be provided for joining ducts of different diameters, the joiner having a first generally UC$17 Sepqen!:r !9$ -4cylindrical neck portion of one diameter and a second generally cylindrical neck portion of another diameter, each neck portion having a retaining clip and seal means. Also, a duct joiner having at least one branching neck portion in addition to main neck portions may be provided for connecting a branch duct to a main duct.

According to another aspect of the invention there is provided a method of connecting a hollow air duct to a duct joiner having a tubular neck portion to provide a connection therebetween comprising the steps of: fitting a retaining clip over the neck portion, the retaining clip being formed of a resilient plastics material and having a ring portion and a plurality of resilient projections extending outwardly from said ring portion; and moving the duct relative to the duct joiner in one direction to fit the duct over the neck portion and the clip, wherein the projections of the clip flex inwardly as the ail duct is moved over the neck portion and the clip and then the projections engage directly with the internal wall of the hollow duct to restrain movement of the duct relative to the duct joiner in an opposite direction away from the duct jciner.

Preferably the duct joiner includes two grooves on its neck portion and the :,,!method involves urging the retaining clip and a seal ring respectively into said oa ~grooves.

0 In order that the invention may be more readily understood, various embodiments thereof will now be described, by way of example only, with reference 4 to the accompanying drawings wherein: ~Figure 1 is a perspective view o a duct joiner and retaining clip in accordance with a first embodiment of the present invention; Figure 2 is a part sectional view of the joiner and retaining clip of Figure 1 S 25 in use; SFigures 3, 4 and 5 are perspective views of various other duct joiners including retaining clips in accordance with the present invention.

Referring to Figures 1 and 2 of the drawings there is shown a duct joiners 11

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\,uLi which cah be connected to a cylindrical air duct 41 by a retaining clip 31 and sealed I R|I, 17 Scptcn'ib199by a sealing ring 36.

As shown in Figures 1 and 2, duct joiner 11 is of tubular form having a central air channel 17 extending therethrough. At Ine end of the duct joiner is a generally cylindrical neck portion 21 defining an outlet portion of the air channel 17, and extending from an annular collar 25 which also encircles the air channel 17.

The neck portion 21 has two substantially parallel annular grooves 22 and 23 in its outer surface and an annular retaining flange 24 at the end of the neck portion 21.

The size of the neck portion 21, the retaining flange 24 and the collar 25 are such tt I I e

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S* A Aw t 1 'ltt p I L.L#3IRS 17'~nc 9 that a duct 41 can extend over the retaining flange 24 with the end of the duct 41 abutting the collar.

The retaining clip 31 comprises a central stiff ring portion 32 and a ring of resilient teeth 33 extending from its outer circumference. The teeth 33 extend partially outwards, to provide a larger circumference than the circumference of the central ring portion, and all of the teeth extend at an angle which is inclined to the plane of the central ring portion 32. The teeth 33 are wider at their inner ends adjacent the ring portion and narrower at their outer ends to provide lateral spaces 34 between the side edges of adjacent teeth 33 so as to allow the resilient teeth to 10 flex inwardly to form a smaller circumference. The retaining clip 31 is preferably made from a plastics material that can be expanded upon heating but which returns t t s to its original size and shape at normal temperatures. The sealing ring 36 comprises a soft eontinuus ring section 37 with a soft continuous resilient skirt 38 extending from the outer edge of the continuous ring 37 in an outwards direction and at an angle inclined to the plane of the continuous ring 37.

In use, the sealing ring 36 is fitted on to the neck portion 21 of the duct joiner 11 by being stretched over the retaining flange 24 and positioned in the groove 23 closest to the collar 25 such that the soft continuous resilient skirt 38 extends from the ring section 37 towards the collar 25. The retaining clip 31 is fitted on to the neck portion 21 of the duct joiner 11 by being heated and stretched over the retaining flange 24 and positioned in the groove 22 closest the flange 24 at the end of the duct joiner. Upon cooling the retaining clip 31 is retained in groove 22. The retaining clip 31 is oriented such that the resilient teeth 33 extend from the ring portion 32 at an inclined angle towards the collar 25. The duct 41 is then p6sitioned over the retaining flange 24 and moved axially relative to the joiner 11 whereby the ring of resilient teeth 33 flex inwardly to present a. smaller circumference and allow the duct to slide over the teeth 33 and to slide over the sealing ring 26 until the end of the duct 41 abuts the collar 25 of the duct joiner 11.

The resilience of the teeth 33 holds the duct in position by engaging with the i Sv CC rAQd t I,11 20 Nenabf 1"I i~ WON-.- -6internal surface 42 of the duct 41. This action is further enhanced by the direction of extension of the teeth 33 being in opposition to the direction of removal of the duct 41 from the duct joiner 11. If removal is attempted the angle of the teeth 33 will cause them to dig into the internal surface 42 of the duct 41. The retaining flange 24 being at the outer edge of the neck portion 21 of the duct joiner 11 ensures that the retaining clip 31 is not pulled off the neck portion 21 but is retained in the groove 22. The annular spacc 43 between the neck portion 21 of the duct joiner 11 and the portion of the duct 41 fitting over the neck portion 21 is sealed by the sealing ring 36 extending from the neck portion 21 to the internal surface 42 of 10 the duct 41. Thereby air flowing through the duct 41 must proceed through the air channel 17 in the duct joiner 11.

In a modified embodiment, the positions of the retaining clip 31 and the I sealing ring 36 may be reversed, with the clip 31 being located in annular greove 23 and the sealing ring 36 located in annular groove 22 adjacent the flange 24.

15 The other end of the duct joiner 11 shown in Figure 1 also includes a similar neck portion 21', retaining clip 31' and sealing ring 36' for connecting the duct joiner 11 to another duct. The size of the other duct may be larger thereby requiring a larger neck portion 21' and consequently larger resilient sealing ring 36' c: and retaining clip 31'.

Referring to Figures 3, 4 and 5, other forms of duct joiners 12, 13 and 14 are shown which include similar retaining clips 31 and sealing rings 36 for connecting and'sealing the joiners to ducts. Duct joiner 12 is a branch joiner having first and second co-axial neck portions 21, 21' and a branching neck portion 121 such that air flowing into the neclk portion 21' can proceed to two air channels 17 and 117 in neck portions 21 and 121 respectively thereby dividing the air flow.

Duct joiner 13 comprises a floor boot having a neck portion 21 and retaining ring 31 which can be connected to a duct to allow air to flow through the air chlanrni 17 in the duct joiner 12 and into a room or the like via an air outlet 18.

Usually the air outlet 18 will be covered by a grille or other outlet diffuser. Duct joiner 14 comprises a ceiling outlet having a neck portion 21 with retaining clip 31 e 1"S la0 ND:116311~~ If "boabr~ j 6- 2, -7and sealing ring and which is also able to connect to a duct and provide an air flow path through the air channel 17 of the duct joiner 14 to a diffuser outlet 19 of the ceiling outlet.

As can be seen the present invention can be used to provide a ducting system whereby a plurality of ducts and duct joiners are used and easily joined by retaining clips 31 and sealed with sealing rings 36. Connection of such a system does not require special tools or skills and substantially reduces the cost of such a system.

It should be evident from the description hereinabove that the present invention provides an improved duct connector and method for connecting ducts 10 which avoids several if not all of the disadvantages of the prior art. Of course many modifications to the above described embodiment may be readily envisaged by persons skilled in the art.

Since modifications within the spirit and scope of the invention may be readily effected by persons skilled in the art, it is to be understood that the invention is not limited to the particular embodiment described, by way of example, hereinabove.

1te, i t 20 ovrmb 1S r

Claims (21)

1. A duct joiner for joining to an air duct of hollow form, said duct joiner having at least one neck portion providing an air channel for the passage of air through the duct joiner, wherein a retaining clip formed of resilient plastics material is mounted to said neck portion, said retaining clip having a ring portion extending around said neck portion and a plurality of a resilient projections extending outwardly from said ring portion at an angle inclined to a plane perpendicular to the longitudinal axis of said tubular neck portion whereby the resilient projections flex inwardly when an air duct is moved over the neck portion, the resilient projections having sharp edges or points which are adapted to dig into the in, t wall of s, duct to restrain movement of the duct away from the joiner,

2. A duct joiner according to claim 1 wherein said neck portion is of tubular form having an annular groove in its outer surface, and the ring portion of said retaining clip is received in said annular groove.

3. A duct joiner according to claim 1 or claim 2 wherein said resilient projections are in the form of teeth with spaces between side edges of adjacent teeth i which allow the teeth to flex inwardly when a duct is fitted onto the neck portion of the joiner. "1 4. A duct ju:ner according to claim 3 wherein the teeth are wider at their 20 inner ends adjacent the ring portion and narrower at their outer ends remote from S- the ring portion. A duct joiner according to any one of the preceding claims wherein the retaining clip is formed from a plastics material that expands when it is heated.

6. A duct joiner according to any one of preceding claims wherein said neck portion has an annular collar which is engageable by an end of the hollow air duct when the duct is fitted over the neck portion.

7. A duct joiner according to any one of the preceding claims further icomprising resilient seal means positioned around the neck portion.

8. A dl\ct joiner according to claim 7 wherein said neck portion has a i By' further annular grobve in its outer surface and a resilient sealing ring is received in *i P6IR RSk CARTER SMITH BEADLE Patent Attorneys for the Applicant TO: Fee: Our Ref: The Commissioner of Patents $280.00 #16313 1~ 1 9- q said further annular groove.

9. A duct joiner according to claim 8 wherein said resilient sealing ring has a ring section and a soft resilient skirt extending outwards from the ring section at an angle inclined to the plane perpendicular to the longitudinal axis of the tubular neck portion. A duct joiner according to claim 8 or claim 9 wherein said neck portion has an annular flange and an annular collar and said retaining clip and said sealing ring are received in annular grooves between said annular flange and said annular collar. 9 11. A duct joiner according to any one of the preceding claims further including an air outlet portion providing an exit channel in communication with said air channel of said neck portion.

12. A duct joiner according to claim 11 wherein the air outlet portion compises a boot for mounting in the floor of a room.

13. A duct joiner according to claim 12 wherein the air outlet portion comprises a diffuser for mounting in thC ceiling of a room.

14. A duct joiner according to any one of claimrs I to 10 comprising a plurality of neck portions, and a plurality of retaining clips each mounted around a respective one of said neck portions. 20 15, A duct joiner according to claim 14 for joining ducts of different diameters wherein the joiner has a first cylindrical neck portion of a first diameter ,and a second cylindrical neck portion of a second diameter, each of said neck too portions having a respective retaining clip mounted thereon.

16. A duct joiner according to claim 14, wherein at least one of said neck portions is a branching neck portion extending in a direction different from another one of said neck portions.

17. A retaining clip for connecting a duct joiner to an air duct having an internal wall, the retaining,clip being formed of resilient plastics material and having a ring portion adapted to be mounted around a neck of the duct joiner and to be retained thereby, and a plurality of resilient projections extending outwardly c- IK Rs 117Septrnber 1998 'NIr r ,,r i I- T CARTER SMITH BEADLE Patent Attorneys fe the Applicant TO: The Commissioner of Patents -t y from said ring portion at an angle inclined to a plane perpendicular to the central axis of the ring portion whereby the resilient projections are adapted to flex inwardly when an air duct is moved over the joiner, the projections having sharp edges or points which are adapted to dig into the internal wall of a duct to retain the duct on the joiner.

18. A retaining clip according to claim 17 wherein said resilient projections are in the form of teeth, the teeth being wider at their inner ends adjacent the ring portion and narrower at their outer ends remote from the ring portion so that there A are spaces between side edges of adjacent teeth.

19. A retaining clip according to claim 17 or claim 18 which is formed from a plastics material that expands when it is heated. A method of connecting a hollow air duct to a duct joiner having a tubular neck portion to provide a connection tnerebetween comprising the steps of: fitting a retaining clip over the neck portion, the retaining clip being formed of a resilient plastics material and having a ring portion and a plurality of resilient projections extending outwardly from said ring portion; and o moving the duct relative to the duct joiner in one direction to fit the duct over the neck portion and the clip, wherein the projections of the clip flex inwardly as the air duct is moved over the neck portion and the clip and then the projections engage 0 20 directly with the internal wall of the hollow duct to restrain movement of the duct Si relative to the duct joiner in an opposite direction away from the duct joiner. J 21. A method according to claim 20 wherein a soft ring seal is fitted over L the neck portion before the duct is fitted over the neck portion, and said ring seal provides a seal between the duct joiner and the duct.

22. A method according to claim 21 wherein said joiner is provided with i grooves in said neck portion aid said ring seal and said retaining clip are fitted onto said neck portion by being urged into respective ones of said grooves. 13. A method according to any one of claims 20 to 22 wherein said retaining clip is heated to expand its ring portion before being fitted onto the neck portion, I D IA iO1RSI 17 Septcmberl998 fitting a retaining clip over the neck portion, the retaining clip being formed of a resilient plastics material and having a ring portion and a plurality of resilient projctions extending outwardly from said ring portion; and moving the duct relative to the duct joiner in one direction to fit the duct over /2 -11-

24. A method according to any one of claims 20 to 23 wherein the duct joiner is provided with a stop collar which is engaged by an end of the duct when the duct is moved over the neck portion in said one direction.

25. A duct joiner for use in a duct joint assembly including an air duct of hollow form having an internal wall and an external wall, said joiner comprising: at least one tubular neck portion having an inner surface, an outer surface, a first end, a second end, a longitudinal axis and providing an air channel for the passage of air through said duct joiner; a retaining clip formed of resilient plastics material mounted to said neck portion, and having a ring portion extending around said neck portion, a plurality of resilient projections extending outwardly from said ring portion at an angle inclined to a plane perpendicular to the longitudinal axis of the neck portion, so that the resilient projections flex inwardly when the air duct is moved over the neck portion, and the resilient projections engage directly with the internal wall of the duct and dig into the internal wall of the duct to restrain movement of the duct away from said duct joiner; a resilient sealing ring having a ring section and a soft resilient skirt extending outwards from the ring section at an angle inclined to the plane perpendicular to said longitudinal axis of the said neck portion; 20 a first annular groove on said outer surface of said neck portion for receiving II II said retaining clip; a second annular groove on said outer surface of said neck portion for 'f *receiving said resilient sealing rig; an annular flange extending radially from said first end of said neck portion so sto be engageable by the internal wall of the hollow duct when the duct is fitted ovifr the neck portion; a( s an annular collar extending radially from said second end of said neck portion so as to be engageable by an end of the hollow air duct when the duct is fitted over the neck portion; and 3 said retaining clip and said sealing ring are received in corresponding ones of L 5 42 IRS 17 Sept"e 1 IRlIR# 631,RSI 17 Seplember 1998 over me necK poron; an annular collar extending radially from said second end of said neck portion so as to be engageable by an end of the hollow air duct when the duct is fitted over the neck portion; and said retaining clip and said sealing ritqg are received in corresponding ones of 913 is ~X.~tll r /3 r "r I r 12 said annular grooves which are disposed in an axially spaced relationship to each other between said annular flange and said annular collar.

26. A duct joint assembly comprising a duct joiner in accordance with any one of claims 1 to 16 or claim 25 and an air duct of hollow form fitted over the duct joiner.

27. A duct joiner substantially as hereinbefore described herein with reference to any one or more of the accompanying drawings.

28. A retaining clip for connecting a duct joiner to a duct substantially as hereinbefore described with reference to the accompanying drawings.

29. A duct joint assembly substantially as hereinbefore described with reference to the accompanying drawings. A method of connecting a duct to a duct joiner substantially as hereinbefore described with reference to the accompanying drawings. DATED: 17 September 1998 CARTER SMITH BEADLE Patent Attorneys for the Applicant: TALANA INVESTMENTS LIMITED I II; I 4) *1 I I It I $1 I I r' JR:IR#16313.RSI 17 September 1998 p -1 ABSTRACT DUCT JOINER AND RETAINING CLIP THEREFOR A duct joiner (11) for connecting an air duct to another duct or other part of an air conditioning system has a tubular neck portion a retaining clip (31) and a sealing ring (36) both mounted on the neck portion. The retaining clip (31) has a ring portion (32) received in a groove (22) in the outer surface of the neck portion (21) and a series of resilient teeth (33) extending outwardly from the ring portion The teeth (33) are resiliently deformable to allow a hollow duct (41) to be fitted over the neck portion (21) and engage with the internal surface of the duct to retain the duct (41) on the neck portion (21) of the joiner The sealing ring i (36) has a ring section (37) received in another groove (22) in the outer surface of the neck portion (21) and a resilient skirt (38) which provides a seal between the neck portion (21) of the joiner and the duct The joiner may have one or more c c' other neck portions (21) with respective retaining clips (31) and sealing rings (36) 15 for joining one duct to one or more other ducts. In other embodiments, the joiner may be provided with an air outlet portion such as a diffuser outlet (19). t tC RNB163 20 November 19999$