AU747502B2

AU747502B2 - Air diverter

Info

Publication number: AU747502B2
Application number: AU86066/98A
Authority: AU
Inventors: Victor John Smith
Original assignee: NORDIN ENGINEERED AIR TECHNOLO
Current assignee: NORDIN ENGINEERED AIR TECHNOLOGIES Pty Ltd
Priority date: 1997-09-30
Filing date: 1998-09-18
Publication date: 2002-05-16
Anticipated expiration: 2018-09-18
Also published as: AU8606698A

Description

P/00/011 Regulation 3.2

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

**BE COMPLETED BY APPLICANT Invention Title: AIR DIVERTER Details of Associated Provisional Application No. P09552 dated 30th September 1997 The following statement is a full description of this invention, including the best method of performing it known to us:- TO BE COMPLETED BY APPLICANT

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Name of Applicant: NORDIN ENGINEERED AIR TECHNOLOGIES PTY LTD Actual Inventor: VICTOR JOHN SMITH Address for Service: A.P.T. Patent and Trade Mark Attorneys GPO Box 772, Adelaide, SA 5001 Invention Title: AIR DIVERTER Details of Associated Provisional Application No. P09552 dated 30th September 1997 The following statement is a full description of this invention, including the best method of performing it known to us:- This invention relates to an air diverter and a method of assembling the air diverter.

BACKGROUND OF THE INVENTION Air diverter assemblies are a common component of air conditioning distribution systems.

They are frequently positioned either at outlets of air conditioning ducting systems in ceilings, or alternatively through wall panels.

Air diverter assemblies usually comprise a frame, which accommodates one or more sets of spaced apart and parallel air diverter blades. The blades can be either fixed in position or may be rotated, depending on the arrangement, independently of each other but increasingly now in concert with each other to divert air in the desired direction.

15 The frames for air diverter assemblies have in the past been manufactured in a number of ways. Diverter frames for ceilings tend to be made integrally, either pressed from sheet metal or more commonly made by plastic injection moulding techniques.

The injection moulding processes result in a product with high tolerances, however, a new mould is required for any substantial variation of the frame, and especially where differences of size are desired. The cost of a mould for such purposes is quite high, and o.06 represents a significant barrier to product development projects, and a significant cost in the production of such articles.

0 o 25 Diverter frames for side wall diverters are still currently manufactured of a metal such as aluminium, because they tend to be used in conjunction with metal diverter blades. The use of metal frames is more expensive in part because of the cost of the metal, and because the techniques used to make such components are slow. Additionally the precision with which such objects are made is somewhat limited often requiring post forming work such as machining, which is expensive and time consuming.

An example of a disclosure of a metal frame made for an air conditioner damper is found in US patent specification 3196895 to Dayus, whereby walls of extruded or rolled metal are locked together to form an outer frame, apertures in which support a plurality of spaced apart blades, which blades are rotated by an internal operating member. Assembly of this arrangement would be somewhat awkward, and the blades need to be put in position before assembly of the outer frame. A disclosure of an example of a metal frame for an air diverter can be found in US patent specification 4103601 to Dayus, which shows the use

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.'19/3/282 14:17 +61-8-84105842 APT PAGE 07/20 +61 8 84105042 3 of an outer frame using lengths of wall material, joined at its corners to make a frame member, and the use of an inner frame consisting of two opposed frame members with apertures therethrough to support a plurality of spaced apart air diverter blades for rotation.

The inner frame is supported within a channel of the outer frame member or fastened directly thereto and needs to be inserted thereinto before assembly of the frame.

US patent specification 4815364 to Wagner et. al. relates to another assembly whereby walls of an air conditioner diverter are assembled from straight frame elements which are extruded and joined by L shaped members with barbs and clips. A set of a plurality of 10 spaced apart blades are supported by two inner frame members, and the inner frame members are supported by the outer frame members by engagement of ridges of the inner frame within grooves of the outer frame. Again the assembly is somewhat awkward in so far as the whole assembly needs to be held together whilst the outer frame is clipped together.

OBJECT OF THE INVENTION

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It is an object of the present invention to provide a diverter assembly that can be made ofl lengths of frame parts, and that permits ease of assembly of the diverter.

S BRIEF SUMMARY OF THE INVENTION i In one broad form but not necessarily the only or broadest form the invention could be said to reside in an air diverter, comprising an outer frame, and an inner frame, and at least one set of a plurality of air diverter blades held in spaced apart relationship by said inner frame to form at least one blade assembly, said outer frame forming a central aperture for passage of air from an upstream part to a downstream part, inner surfaces of the outer frame having an inner frame capturing means, and an outer portion of the inner frame having a detente for engagement with said capturing means, so that the blade assembly can be snap fitted into the central aperture by placement axially within said central aperture, wherein the outer frame and the inner frame are made from respective outer frame and inner frame plastics extrusions and the outer frame extrusion can be cut to form outer frame lengths and the outer frame lengths joined together with joining means to form the outer frame.

1 9. MAR. 15 4 PRINT TIME 19. MAR, 16:06 19/03/2002 14:17 +61-8-84165042 +61 8 84105042

APT

PAGE 08/20 Preferably the outer frame and the inner frame are made from respective outer frame and inner frame plastics extrusions. The outer frame extrusion is preferably made of an extruded generally L shaped plastics wall portion, a lower portion of the L forming a flange in the frame, and an upright portion forming upright walls of the outer frame. The outer frame and inner frame plastics extrusions are cut to lengths, with joining means joining outer frame lengths together to form the outer frame.

See e e ECEIVED TIME 19.MAR. 15:43 PRINT TIME 19,MAR, 16:05 Preferably the lower portion of the outer frame includes a press fitted joining means for a press fitted join between outer frame lengths.

Preferably the joining means comprises a channel formed within the flange of the outer frame extrusion, and an L shaped joining member to fit within the channel. The press fitting can be achieved by reason of recesses or protrusions within sides of the channel, and corresponding protrusions or recesses on the L shaped joining member.

The capturing means of the outer frame can be either a recess or a protrusion, with a corresponding portion of the respective inner frame including a co-acting protrusion or recess, which snap fits into engagement. The outer frame is preferably formed so as to permit snap fitting of the inner frame from the downstream part of the air diverter.

oeoo Preferably locating means are also provided to locate the respective inner frame in position, so that the extent of lateral movement of the inner frame is limited and that there is no *.overshoot in fitting the inner frame within the outer frame.

S•.In a first specific aspect of the invention two blade assemblies are provided, a first of said S:blade assemblies including a first of the set of air diverter blades supported at an upstream part of the central aperture, and a second of said blade assemblies including a second of the corresponding set of air diverter blades supported at a downstream part of the central aperture, said first set of air diverter blades aligned laterally with respect to the second set of air diverter blades.

25 Preferably each of the two blade assemblies can separately be press fitted into position.

Preferably each of said two inner frames includes only two opposed end frame elements.

Either the first or the second inner frame member may extend from an upstream part to the downstream part of the central aperture and one or other must do so if it is desired to have only a single capturing means on the inner surface of the outer frame member extrusion.

This has the advantage insofar as that where there are two capturing means spaced apart axially, then the snap fit of the first capturing means cannot be all that definite because the fit must be broken to progress the detente on to the second capturing means for further engagement. Thus for example a single capturing recess or protrusion may be formed at an upper part of the upright portion of the outer frame member.

Each of the blades may be formed from a plastics blade extrusion, the blade extrusion having an internal pin capturing channel, said inner frame members each having spaced apart pin apertures, with a respective pin passing therethrough and extending into the internal pin capturing channel of a respective blade.

The invention could also encompass a method of assembling an air diverter the method comprising the steps of cutting outer frame length from an extrusion, joining the outer frame lengths together to form an outer frame which includes a central aperture, cutting a pair of inner frame elements from an inner frame extrusion, and forming a plurality of spaced apart and aligned pin apertures in each of said pair of inner frame elements, cutting a plurality of blades from a blade extrusion said blade extrusion including a pin channel, aligning a respective pin channel of each of said plurality of blades with respective apertures in the pair of inner frame members, attaching the pair of inner frame members to either end of each of the blades by inserting a pin through a respective pin aperture and pin channel to frictionally engage said inner channel but permit rotation within the aperture thereby forming a blade assembly, inserting the blade assembly axially into the central aperture formed within the outer frame and snap fitting the blade assembly into position.

DETAILED DESCRIPTION OF THE DRAWINGS For a better understanding, two specific embodiments of the invention will now be described with reference to the following drawings: SoFigure 1 is a view of an assembled air diverter from beneath, showing the 25 flange and the arrangement of two sets of air diffuser blades; Figure 2 is a perspective view from above of the assembled air diverter; Figure 3 is a cross sectional view through A-A of Figure 1 showing details of a first embodiment of the assembly of the air diverter; Figure 4 is a cross sectional view through B-B of Figure 1 showing further detail of the first embodiment of the air diverter; Figure 5 is a view similar to that of Figure 3 for a second embodiment; Figure 6 is a view similar to that of Figure 4 for a second embodiment; Figure 7 shows detail of the plan and cross section views of a first inner frame member extrusion, for the first and second embodiments; Figure 8 shows detail of the plan and cross section views of a second inner frame member extrusion, for the second embodiment; Figure 9 shows detail of the cross section view of the outer frame member extrusion, for the first embodiment; and Figure 10 shows detail of the cross section of the blade for the first and second embodiments.

It will be appreciated that the accompanying drawings are sketches illustrating the embodiments. Throughout the drawings the same reference numeral is used to refer to the soea 15 same feature.

b* Dimensions of certain of the parts as shown in the drawings may have been modified •**and/or exaggerated for the purposes of clarity of illustration and may be incomplete.

DETAILED DESCRIPTION The illustrated air diverter is comprised of an outer frame two inner frames 3) and two sets 5) of a plurality of diverter blades The outer frame forms a central aperture for passage of air from an upstream part of the diverter to a downstream 25 part of the diverter. Inner surfaces (10, 11) of the outer frame have an inner frame capturing means (12, 13), and an outer portion of the inner frame have a detente means (14) for engagement with the capturing means so that the inner frame can be press fitted into the central aperture by placement axially.

Many of the component parts of the illustrated diverters are made from extruded plastics parts. Thus the outer frame is formed from lengths of an outer frame extrusion an extrusion the shape of which is best illustrated in Figure 9. The shape of the inner frame extrusions (16, 17) is best seen from Figures 7 and 8, and the shape of the blade extrusion (18) is best seen in Figure 10. These extruded parts are cut to lengths and then fitted together simply with the aid of some connector means to form a diverter of desired dimensions. The inner frame extrusion is punched to form pin apertures (20) therethrough for subsequent passage of pins (21).

The outer frame extrusion (15) has an L shaped cross section (22) with a wall forming portion and a flange forming portion The flange forming portion in use fits under a ceiling or over a wall facing the living area, to dress the diverter so as to make it more aesthetically pleasing. A channel (25) is formed within the hidden side of the flange forming portion. Two barb shaped ridges (26, 27) are formed on either side of walls (28, 29) forming the channel. An L shaped plastics joining member (30) can be press fit into the channel. The L shaped joining member is pushed, at least in part, past the barb shaped ridges which deform to allow passage of the L shaped joining member, and then grip the L shaped joining member to capture it in place. In this manner, the outer frame extrusion can be cut to length and mitred. The mitred outer frame lengths are placed into position following which the plastics joining member are press fit into the comers to thereby form an outer frame. It may also be desired to clip together an upstream part of the wall forming portion (30) of the lengths of the outer frame.

A first of the inner frames is nanrrower in cross sectional width than the second of the inner frame extrusions. The first of the inner frame extrusions (17) includes a central web (31) and two protrusions (32, 33) extending to the same side of the web as each other. A downstream facing side of an upstream of the two protrusions includes a bevel A second of the inner frame extrusions (16) includes a central web an upstream protrusion a central protrusion (37) and a downstream protrusion The upstream protrusion includes a downstream facing bevel (39).

The wall forming portion (23) of the outer frame extrusion includes a capturing means which is in the form of a specifically shaped ridge The blade extrusion (18) is shown in Figure 10 and is airfoil shaped in cross section comprising two arcuate and thin external walls (41, 42) which are joined with a leading curved portion (43) of smallest radius, and a lagging curved portion (44) of larger radius.

A centrally disposed pin channel (45) is formed between two thin transverse walls (46, 47).

The blade extrusion is cut to lengths required to form blades suitable for the diverter size required. The cutting can be by guillotining. Two lengths of each of the first inner frame extrusion and second inner frame extrusion are cut to form inner frame elements of a size to suit the diverter that is required. Pin apertures are punched through the inner frame extrusions. The diverter blades are aligned, between a respective pair of either first or second inner frame extrusions, such that pin apertures in the frame elements align with pin channels in the blades. A respective pin is inserted through each of the pin apertures and 8 extends through to the pin channels so that the blades are captured between a pair of inner frame elements. The diameter of the pin aperture in the inner frame elements is somewhat larger than the cross sectional dimension of the pin channel of the blade, and accordingly the blade is held firmly between the frames but rotation of the blades relative to the pair of inner frames is achievable. Together the blades and two inner frame elements form a blade assembly. Greater detail regarding the blades, and the means by which they are supported in the inner frames can be seen from co-filed application entitled air diverter blade and an air diverter assembly by the present applicant.

The blade assembly can then be inserted into the outer frame. It will be understood that both blade assemblies comprise a plurality of spaced apart blades supported at either end by an inner frame element. The protrusions of the inner frame element are outwardly facing so that the protrusions face the inner surface of the outer frame on insertion of the •blade assembly within the central aperture.

The assembled diverter of the first embodiment is shown in Figures 3 and 4. The first of the blade assemblies is inserted first (not shown) so that the plurality of blades that it S0 supports is held in place at an upstream part of the diverter. On insertion the first blade O assembly is guided closely in position by protrusions (37, and 38), until the upstream 00020 protrusion (36) contacts the specifically shaped ridge (40) on the inner surface of the outer o -o frame. The first inner frame member deforms slightly on axial pressure on the blade S0. assembly to ride over the ridge (40) and fit upstream of the ridge. The extent to which the first blade assembly can be moved axially is limited by an upstream flange (48) which extends inwardly to the central aperture, and thus acts as a stop on the inner frame member.

The second of the blade assemblies is inserted such that the blades of the second blade assembly extend laterally with respect to the blades of the first blade assembly. The second blade assembly is inserted in a manner that is similar to that in which the first blade assembly is inserted until the bevel (39) of upstream protrusion (36) is captured upstream of the ridge The blades are held in place at a down stream portion of the inner frame elements. In this manner the outer frame extrusion can be made with a single ridge which facilitates the assembly of the diverter. The inner frame elements assist with making the outer frame more rigid because they fit closely inside of the outer frame element.

The second embodiment is shown in Figures 5 and 6 and is simply a variant of the first embodiment in that two ridges are formed in the outer frame extrusion, a first of the ridges (49) being approximately central in the central aperture, and captures the blade assembly with a narrower inner frame element, a second of the ridges (50) being upstream of the central aperture and captures the blade assembly with a wider inner frame element, although a narrower inner frame element could also be used.

Various features of the invention have been particularly shown and described in connection with the exemplified embodiment of the invention, however, it must be understood that these particular a-rrangements merely illustrate and that the invention is not limited thereto and can include various modifications falling within the spirit and scope of the invention.

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*ooeo ooe oee*

Claims

1. An air diverter including an outer frame, an inner frame, and at least one set of a plurality of air diverter blades held in spaced apart relationship by said inner frame to form at least one blade assembly, said outer frame forming a central aperture for passage of air from an upstre;am part to a downstream part, inner surfaces of the outer frame having an inner frame capturing means, and an outer portion of the inner frame having a detente for engagement with said capturing means, so that the blade assembly can be snap fitted into the central aperture by placement axially within said central aperture. wherein the outer frame and the inner frame are made from respective outer frame and inner frame plastics extrusions and the outer frame extrusion can be cut to form outer frame lengths and the outer frame lengths joined together with joining means to form the outer frame.

2. An air diverter according to claim I wherein the outer frame extrusion is made of an extruded L shaped wall portion, a lower portion of the L forming a flange in the frame, and an upright portion forming upright walls of the outer frame. o

3. An air diverter according to claim 2 wherein the joining means comprises a channel formed within the flange of the outer frame extrusion, an L shaped joining member to fit within the channel and recesses or protrusions within sides of the channel with corresponding protrusions or recesses on the L shaped joining member such that a press; fitting can be achieved.

4. An air diverter according to claim 5 wherein two barb shaped ridges are formed on either side of walls forming the channel and the barb shaped ridges deform to allow passage of the L shaped joining member, and then grip the L shaped joining member such that it is press fitted in place. An air diverter according to one of the preceding claims wherein the capturing means of the outer frame is a recess, with a corresponding portion of the respective inner frame including a co-acting protrusion which snap fits into engagement with the outer frame recess. A 6. An air diverter according to one of claims 1 to 4 wherein the capturing means of the outer frame is a protrusion, with a corresponding portion of the respective inner frame RECEIVED TIME 19. MAR. 15:43 PRINT TIME 19. MAR. 16:05 19/03/2802 14:17 +61-8-84105642 A APT PAGE 16/20 +61 8 84105042 11 including a co-acting recess which snap fits into engagement with the outer frame protrusion.

7. An air diverter according to claim 6 wherein the upright portion of the outer frame extrusion includes a capturing protrusion which is in the form of a ridge.

8. An air diverter according to claim 7 wherein on insertion of the blade assembly the ridge causes the inner frame member to deform slightly and allow the first blade assembly to ride over the ridge and fit upstream of the ridge.

9. An air diverter according to one of the preceding claims wherein locating means are provided to locate the respective inner frame in position so that the extent of lateral movement of the inner frame is limited.

10. An air diverter according to claim 9 wherein the locating means are protrusions on an outer face of the inner frame, said protrusions restricting lateral movement of the inner frame by contact with the inner surfaces of the outer frame.

11. An air diverter according to claim 10 wherein the extent to which the blade assembly can be moved axially. is limited by an upstream flange on the outer frame which extends inwardly to the central aperture and acts as a stop on the inner frame member. S. 12. An air diverter according to one of the preceding claims wherein two blade assemblies are provided, a first of said blade assemblies including a first of the set of air diverter blades supported at an upstream part of the central aperture, and a second of said blade assemblies including a second of the corresponding set of air diverter blades supported at a downstream part of the central aperture, said first set of air diverter blades aligned laterally with respect to the second set of air diverter blades.

13. An air diverter according to claim 12 wherein each inner frame of said two blade assemblies includes only two opposed end frame elements.

14. An air diverter according to claim 13 wherein end frame elements of the first blade assembly are narrower in cross sectional width than end frame elements of the second blade assembly and the end frame elements of the first blade assembly include a central 3 web, an upstream protrusion and a downstream protrusion, said protrusions extending to CEIVED TIME 19. MAR. 15:43 PRINT TIME 19.MAR. 16:05 ,19/03/,2002 14:17 +61-8-84105042 A APT PAGE 17/20 +61 8 84105042 12 the same side of the web as each other, a downstream facing side of the upstream protrusion including a bevel. An air diverter according to claim 14 wherein the end frame elements of the second blade assembly include a central web, an upstream protrusion, a central protrusion and a downstream protrusion, said protrusions extending to the same side of the web as each other, the upstream protrusion including a downstream facing bevel.

16. An air diverter according to claim 15 wherein the first and second blade assemblies are inserted such that the bevel of the upstream protrusions of the first and second blade :assemblies is captured upstream of the ridge.

17. An air diverter according to claim 15 wherein two ridges are formed in the outer frame extrusion, a first of the ridges being approximately central in the central aperture, and capturing the first blade assembly with a narrower inner frame element, a second of the ridges being upstream of the central aperture and capturing the second blade assembly with a wider inner frame element.

18. An air diverter according to one of the preceding claims wherein the blades are formed from a plastics blade extrusion, the blade extrusion having an internal pin capturing channel, said inner frame members each having spaced apart pin apertures, with a •respective pin passing therethrough and extending into the internal pin capturing channel of a respective blade.

19. An air diverter according to claim 18 wherein the blade extrusion is airfoil shaped in cross section and comprises two arcuate and thin external walls which are joined with a leading curved portion of smallest radius, and a lagging curved portion of larger radius, and a centrally disposed pin channel is formed between the two thin transverse walls. A method of assembling an air diverter, the method including the steps of: cutting outer frame lengths from an extrusion, joining the outer frame lengths together to form an outer frame which includes a central aperture, cutting a pair of inner frame elements from an inner frame extrusion, forming a plurality of spaced apart and aligned pin apertures in each of said pair of inner frame elements, ;ECEIVED TIME 19.MAR. 15:43 PRINT TIME 19. MAR. 16 0 19/03/,2002 14:17 +61-8-84105042 A APT PAGE 18/20 +61 8 84105042 13 cutting a plurality of blades from a blade extrusion, said blade extrusion including a pin channel, aligning a respective pin channel of each of said plurality of blades with respective apertures in the pair of inner frame members, attaching the pair of inner frame members to either end of each of the blades by inserting a pin through a respective pin aperture and pin channel to frictionally engage said inner channel but permit rotation within the aperture thereby forming a blade assembly, inserting the blade assembly axially into the central aperture formed within the outer frame and snap fitting the blade assembly into position. S" 21. A method of assembling an air diverter according to claim 20 wherein the outer frame extrusion is made of an extruded L shaped plastics wall portion, a lower portion o f the L forming a flange in the frame, and an upright portion forming upright walls of the outer frame.

22. A method of assembling an air diverter according to claim 21 wherein the outer frame lengths are joined together using a joining means, said joining means comprising a channel formed within the flange of the outer frame extrusion, an L shaped joining member to fit within the channel and recesses or protrusions within sides of the channel with corresponding protrusions or recesses on the L shaped joining member such that the press fitting can be achieved. t S

23. A method of assembling an air diverter according to claim 22 wherein two barb shaped ridges are formed on either side of walls forming the channel and the barb shaped ridges deform to allow passage of the L shaped joining member, and then grip the L shaped joining member such that it is press fitted in place.

24. A method of assembling an air diverter according to one of claims 20 to 23 wherein inner surfaces of the outer frame have a capturing protrusion which is in the form of a specifically shaped ridge, and a corresponding portion of the respective inner frame includes a co-acting recess which snap fits into engagement with the ridge. A method of assembling an air diverter according to claim 24 wherein on insertion of the first blade assembly the specifically shaped ridge causes the first inner frame member to deform slightly and allow the first blade assembly to ride over the ridge and Fit RA upstream of the ridge. -E ECEIVED TIME 19. MAR. 15:43 PRINT TIME 19. MAR. 16:04 .19/03,/2002 14:17 +61-8-84105042 1 APT PAGE 19/20 +61 8 84105042 14

26. A mnethod of assembling an air diverter according to claim 25 wherein two blade assemblies are provided, a first of said blade assemblies including a first of the set of air diverter blades supported at an upstream part of the central aperture, and a second of said blade assemblies including a second of the corresponding set of air diverter blades supported at a downstream part of the central aperture, said first set of air diverter blades aligned laterally with respect to the second set of air diverter blades.

27. An air diverter according to claim 26 wherein each inner frame of said two blade assemblies includes only two opposed end frame elements, A method of assembling an air diverter according to claim 27 wherein end frame •go"'.elemens of the first blade assembly are narrower in cross sectional width than end frame ":':elements of the second blade assembly and the end frame elements of the first blade :":assembly include a central web, an upstream protrusion and a downstream protrusion. said protrusions extending to the same side of the web as each other, a downstream facing side •00 of the upstream protrusion including a bevel.

29. A method of assembling an air diverter accor 1ding to claim 28 wherein the end frame •,•0elements of the second blade assembly include a central web, an upstream protrusion, a central protrusion and a downstream protrusion, said protrusions extending to the sanie e0 side of the web as each other, the upstream protrusion including a downstream facing bevel. "30. A method of assembling an air diverter according to claim 29 wherein the second of the blade assemblies is inserted such that the bevel of the upstream protrusion is captured upstream of the specifically shaped ridge and the blades are held in place at a downstream portion of the inner frame elements.

31. A method of assembling an air diverter according to claim 29 wherein two ridges are formed in the outer frame extrusion, a first of the ridges being approximately central. in the central aperture, and capturing the blade assembly with a narrower inner frame element, a second of the ridges being upstream of the central aperture and capturing the blade assembly with a wider inner frame element.

32. A method of assembling an air diverter according to one of claims 20 to 31. wherein the blades are formed from a plastics blade extrusion, the blade extrusion havifig an internal pin capturing channel, salea inner frameimembers each having spaced apart pin IVED TIME 19, MAR. 15:43 PRINT TIME 19. MAR. 16':04 19/83288002 14:17 +61-8-84185842 +61 8 84105042 A APT PAGE 28/28 apertures, with a respective pin passing therethrough and extending into the interndal pin capturing channel of a respective blade.

33. A method of assembling an air diverter according to claim 32 wherein the blade extrusion is airfoil shaped in cross section and comprises two arcuate and thin external walls which are joined with a leading curved portion of smallest radius, and a lagging curved portion of larger radius, and a centrally disposed pin channel is formed between the two thin transverse walls.

34. An air diverter substantially as hereinbefore described with reference to the accompanying drawings. SO S. 0~ 0 0 iS. go S6 oo.o. oO*O O*o* 0 S.. 00 S 0 0 O0O0 S.o S S S 09 S O0 0 O00 S S ft 0 *500 *005 0 00 660000 0 Dated this 19th day of March 2002 NORDIN ENGINEERED AIR TECHNOLOGIES PTY LTD By their Patent Attorneys A.P.T. Patent and Trade Mark Attorneys RECEIVED TIME 19, MAR, 15:43 PRINT TIME 19. MAR, 16:04