AU2010201469B2

AU2010201469B2 - A damper assembly incorporating blade guard means

Info

Publication number: AU2010201469B2
Application number: AU2010201469A
Authority: AU
Inventors: Stefan Reich
Original assignee: AIR DIFFUSION AGENCIES Pty Ltd
Current assignee: AIR DIFFUSION AGENCIES Pty Ltd
Priority date: 2009-04-14
Filing date: 2010-04-14
Publication date: 2015-05-28
Anticipated expiration: 2030-04-14
Also published as: AU2010201469A1

Abstract

5 This disclosure relates to a damper assembly comprising a blade pivotally mounted in a length of substantially rigid duct between a pair of ends of the rigid duct, so that the blade may be rotated about its pivotal mounting to a position where at least a portion of said blade extends beyond an end of the rigid duct. The damper assembly further comprises selectively deployable blade guard means adapted to prevent obstruction of the blade's operation by flexible ducting connected to an end of the damper 0 assembly. 1 4' 4b 4a' Fig1 12 -0 Fig 2

Description

Regulation 3.2 AUSTRALIA PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT ORIGINAL Name of Applicant: Connect Air Manufacturing Pty Ltd Actual Inventor: Stefan Reich Address for Service: C/- MADDERNS, Level 4, 19 Gouger Street, Adelaide, South Australia, Australia Invention title: A DAMPER ASSEMBLY INCORPORATING BLADE GUARD MEANS The following statement is a full description of this invention, including the best method of performing it known to us.

TITLE * A DAMPER ASSEMBLY INCORPORATING BLADE GUARD MEANS 5 FIELD OF THE INVENTION This disclosure relates to devices for controlling air flow in ducted heating, ventilation, and air conditioning (HVAC) systems, these being more commonly known as dampers. 0 PRIORITY This patent application claims priority from: -Australian Provisional Patent Application 2009901579, titled "A DAMPER ASSEMBLY 5 INCORPORATING BLADE GUARD MEANS", and filed on 14 April 2009. The entire content of this application is hereby incorporated by reference. BACKGROUND '0 Most dampers are an assembly comprising a disc shaped blade pivotally mounted in an elongate tubular housing between an inlet and an outlet thereof. This disc shaped blade may be rotated about its pivotal mounting between positions normal or parallel to the direction of elongation of the housing. In this way, fluid flow through the housing may be either largely unimpeded or substantially obstructed. 25 Many HVAC installations make use of flexible ducting made from flexible plastic extending over a metal wire coil to make round, flexible duct. Where a damper is employed, a length of this flexible ducting may be connected to both the inlet and the outlet of the damper housing. If the housing of a damper assembly were to have a length which was less than the diameter of the 30 blade pivotally mounted therein, then it would become possible for the flexible ducting to foul or be caused to foul operation of the blade, such as by being pinched or kinked, or possibly due to external objects bearing against it. As a result, it has hitherto been a necessity that the housing length be greater than the diameter of the blade. This however makes these damper assemblies large and bulky, a distinct disadvantage when working in confined roof spaces and when shipping these items. 35 It is against this background, and the problems and difficulties associated therewith, that the present invention has been developed. 2 Certain objects and advantages of the present invention will become apparent from the following description, taken in connection with the accompanying drawings, wherein, by way of illustration and example, embodiments of the present invention are disclosed. 5 SUMMARY OF THE INVENTION In one aspect there is proposed a damper assembly comprising a blade pivotally mounted in a length of substantially rigid duct between a pair of ends of the rigid duct, so that the blade may be rotated about its pivotal mounting to a position where at least a portion of said blade extends beyond an end of 0 the rigid duct, the damper assembly further comprising selectively deployable blade guard means adapted to prevent obstruction of the blade's operation by flexible ducting connected to the or each end of the substantially rigid duct equipped with said deployable blade guard means. Obstruction of the blade's operation may occur where a length of flexible ducting attached to the 5 damper assembly fouls or is caused to foul operation of the blade. This can occur where the flexible ducting has been forced up against an external body such as a roof support member, causing localised collapse of the flexible ducting, or where the flexible ducting has been inadvertently pinched or kinked during installation. '0 In one form, the selectively deployable blade guard means comprise one or more substantially rigid elements that project from at least one end of the rigid duct when deployed. In one form, the selectively deployable blade guard means comprise a rigid duct of extendible length, so that the selectively deployable blade guard means are deployed by extending the extendible rigid 25 duct. In one form, the or each rigid element is selectively attachable to and detachable from the substantially rigid duct, and is deployed by being attached to the rigid duct. 30 In one form, the or each rigid element is adapted to extend and retract relative to the substantially rigid duct, and is deployed by being extended. In one form, the assembly comprises at least two portions of rigid duct adapted to telescope relative to one another. 35 In one form, the or each rigid element is a further substantially rigid duct segment adapted to be attached to the or each end of the substantially rigid duct in which the blade is mounted. 3 The damper assembly of claim 4, wherein the or each rigid element is attached by way of snap fit or fasteners or the like. The damper assembly of claim 5, wherein the or each rigid element is deployed by sliding or telescoping with respect to the substantially rigid duct. 5 In one form, the or each rigid element is deployed by pivoting or rotating relative to the substantially rigid duct. In one form, the or each rigid element is of an arcuate shape which is pivotally attached at each end thereof to the substantially rigid duct so that this can pivot between an extended position and a retracted position. 10 In one form, the selectively deployable blade guard means comprises two arcuate rigid elements pivotally connected to the substantially rigid duct at positions separated by 90 degrees. In one form, when the two arcuate members are deployed, one passes around the outer edge of the other, inner element. In one form, when the two arcuate members are deployed, the inner element is adapted to releasably 15 engage the outer element so that the two elements support each other in their extended positions. In one form, at least one end of the damper assembly is adapted to be connected to either of flexible ducting or another HVAC fitting. In one form, there are two or more blades pivotally mounted in the length of substantially rigid duct, where these two or more blades act cooperatively to block the duct. 20 In one form, the assembly comprises selectively deployable blade guard means at each end of the substantially rigid duct. In one form, the blade is disc shaped, the rigid duct is tubular, and the length of the rigid duct is less than the diameter of the blade. In one form, the blade and rigid duct are of matching polygonal shapes. 25 In one form, the blade and rigid duct are of matching rectilinear shapes. In a further aspect, there resides a damper assembly comprising a disc shaped blade pivotally mounted in a tubular housing between a pair of ends thereof, so that the blade may be rotated about its pivotal mounting to a position where at least a portion of said blade extends beyond both ends of the housing, the damper assembly further comprising selectively deployable blade guard means adapted to prevent obstruction of the blade's operation by flexible ducting connected to either end of the damper assembly. In one form, the rigid duct may have a single inlet and a single outlet. Optionally, the duct may have 5 multiple outlets, as a result of the duct dividing into a number of branches at a point downstream of the blade. In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the 10 arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of embodiments in addition to those described and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting. 15 The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate certain embodiments of the invention, and together with the description, serve to explain the principles of the invention. !0 Those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilised as a basis for designing other structures, methods, and systems for carrying out the several purposes of the present invention. It is important, therefore, to recognise that any claims should be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention. 25 BRIEF DESCRIPTION OF THE DRAWINGS For a better understanding of this disclosure it will now be described with respect to one or more exemplary embodiments, which shall be described herein with the assistance of drawings wherein: 30 Figure I is a perspective view of a damper assembly according to a first exemplary embodiment, where the blade guard means pivot relative to the substantially rigid duct, and these blade guard means are shown in a retracted position; 35 Figure 2 is a perspective view of the damper assembly in Figure 1, where these blade guard means are shown deployed i.e. in an extended position; Figure 3 is a perspective view of a damper assembly according to a second exemplary embodiment, where the blade guard means translates relative to the substantially rigid duct, and these blade guard means are shown in a retracted position; 5 Figure 4 is a perspective view of the damper assembly in Figure 3, where these blade guard means are shown deployed i.e. in an extended position; Figure 5 is a perspective view of a damper assembly according to a third exemplary embodiment, where the blade guard means are removable from the substantially rigid duct, and these blade guard 0 means are shown removed; Figure 6 is a perspective view of the damper assembly in Figure 5, where these blade guard means are shown deployed i.e. attached and extending from the substantially rigid duct; 5 Figure 7 is a perspective view of a damper assembly according to a fourth exemplary embodiment, where the blade guard means telescope with respect to the substantially rigid duct, and these blade guard means are shown in a retracted position; Figure 8 is a perspective view of the damper assembly in Figure 7, where these blade guard means are !0 shown deployed i.e. in an extended position; Figure 9 is a plan view or a damper assembly according to a fifth exemplary embodiment, where the length of the rigid duct is extendible, and this rigid duct is shown retracted and shortened; 25 Figure 10 is a plan view of the damper assembly in Figure 9, where the rigid duct is shown deployed i.e. extended and lengthened; Figure I 1 is a perspective view of a damper assembly according to a sixth exemplary embodiment, where the length of the rigid duct is extendible by the addition of further rigid duct segments adapted 30 to be attached to each end of thereof; Figure 12 is a perspective view of a damper assembly according to a seventh exemplary embodiment that is similar to the first, where the blade guard means for this are shown deployed i.e. in an extended position, at one end; 35 Figure 13 is a perspective view of the damper assembly in Figure 12, where the blade guard means are shown retracted; Figure 14 is a perspective view of the damper assembly in Figures 12 and 13, where this is equipped with blade guard means at both ends, and the means at both ends are deployed; Figure 15 is a perspective view of a damper assembly incorporating the damper assembly of Figure 5 12, this damper assembly incorporating blade guard means at both ends thereof; Figure 16 is a plan view of the damper assembly as illustrated in Figure 15; Figure 17 is a side view of the damper assembly as illustrated in Figures 15 and 16; and. 0 Figure 18 is a perspective view of a portion of the damper assembly illustrated in Figures 12 through 17. In the following description, like reference characters designate like or corresponding parts throughout 5 the several views of the drawings. DETAILED DESCRIPTION Referring now to Figure 1 and 2, where an exemplary embodiment of a damper assembly 1 is '0 illustrated. This damper assembly 1 comprises a disc shaped blade 2 pivotally mounted in a tubular length of substantially rigid duct 4 by a pair of oppositely directed pins 2a, which extend from the blade 2 and through the wall of the rigid duct 4 at a position between a pair of ends 4a and 4b of the rigid duct 4. 25 Whilst the components of the damper assembly 1 illustrated are components moulded from plastic, it should be understood that one or more of the components may be made from other materials, including metal, aluminium or even composites. The blade 2 may be driven (by an electric motor for instance) so as to rotate about its pivotal mounting 30 (i.e. pins 2a) between positions substantially normal and parallel to the direction of elongation of the rigid duct 4. In this way, fluid flow through the rigid duct 4 may be either largely unimpeded or substantially obstructed, as desired. A flexible seal 6 extends around the periphery of the disc shaped blade 2 so as to improve sealing 35 between the blade 2 and the inner wall of the substantially rigid duct 4 when the blade 2 is at or approaching the position substantially normal to the direction of elongation of the rigid duct 4. 7 In use, the damper assembly I may be inserted between two lengths of flexible ducting (represented here with dashed lines), where a length of flexible ducting may be attached to both ends 4a and 4b of the damper assembly's length of substantially rigid duct 4. To aid secure attachment of the flexible ducting, the outer surface of the rigid duct 4 may be both ribbed and diametrically tapered towards it 5 ends 4a and 4b. The length of the rigid duct 4 is less than the diameter of the blade 2, so when the blade 2 is at or approaching the position substantially parallel to the direction of elongation of the rigid duct 4, portions of the blade 2 will extend past the ends 4a and 4b of the rigid duct 4. 0 As such, the damper assembly I includes selectively deployable blade guard means 10 adapted to, in this embodiment, selectively project from each end 4a and 4b of the substantially rigid duct 4 and prevent the flexible duct attached thereto from fouling operation of the blade 2. 5 In this exemplary embodiment, the blade guard means 10 takes the form of a substantially rigid, arcuate element (a strip in this case and hereinafter) 12, which arches from one side of an end (be it end 4a or end 4b) of the rigid duct 4 to the other side of that end, diametrically across the opening in that end. Each end of the arcuate strip is pivotally attached to the rigid duct 4, so that the arcuate strip 12 may be deployed by being rotated through approximately 90 degrees between a retracted position :0 and an extended position relative to the end (be it end 4a or end 4b) of the rigid duct 4. In the retracted position, the arcuate strip 12 locates adjacent the end of the rigid duct 4, in a position substantially normal to the direction of elongation of the rigid duct 4. When deployed (i.e. rotated into the extended position), the arcuate strip 12 projects out from the end 25 of the duct 4 in a direction parallel to the direction of elongation of the rigid duct 4. It would be understood that optionally, a central portion of arcuate strip 12 may be omitted, so that there are two independently operating segments thereof. 30 In this embodiment, two of these arcuate strips 12 are employed at each end 4a and 4b of the rigid duct 4, where pairs of these arcuate strips 12 are pivotally attached to the rigid duct 4 such that when they are both deployed (i.e. extended), they will cross the opening in that end (be it end 4a or end 4b) of the rigid duct 4 at 90 degrees to one and other. Moreover, one of the arcuate strips 12 at each end of the rigid duct 4 is pivotally attached thereto at points aligned with the pivot points 2a of the blade 2. 35 Those portions of the arcuate strips 12 which will in use be located in the flow stream may be shaped so as to minimise flow losses through the rigid duct 4, such as by shaping them like appropriately directed (with respect to the direction of fluid flow through the duct) airfoils. 5 In use then, the damper assembly 1 may be packaged and shipped with the blade guard means 10 retracted relative to the rigid duct 4. Packaging and freight costs for this damper assembly I then will be considerably less than those for a conventional damper assembly having a longer rigid duct length. It is not until an HVAC system installer is ready to insert the end of damper assembly I into a length of flexible duct that the guard means 10 needs to be extended from the rigid duct 4. This then means 10 that the damper assembly I can be carried through a manhole and into a roof cavity with the guard means 10 retracted, a feature that will be appreciated by the installer. Referring now to Figures 3 and 4, where a damper assembly 15 according to a second exemplary embodiment is illustrated, in which the selectively deployable guard means 10 are rigid rod-like 15 elements 20 retained in slots 22 that extend in the direction of elongation of the rigid duct 40 so that the rods 20 may be deployed by sliding into and out of these slots 22 as required. A series of these rods 20 are positioned around the periphery of each end 40a and 40b of the rigid duct 40 at equi spaced intervals. When retracted, these rods 20 are located within their respective slots 22. When required, the rods 20 are extended from their respective slots 22 so as to project from the ends 40a and 20 40b of the rigid duct 40. In Figures 3 and 4 rods 20 are illustrated straight, but may, optionally, be curved. Referring now to Figures 5 and 6, where a damper assembly 60 according to a third exemplary 25 embodiment is illustrated, in which the selectively employable guard means 10 take the form of rigid rod-like elements 70 adapted to be deployed by being inserted in rod receiving 80 apertures by snap fitting or the like, so that they will extend in the direction of elongation of the rigid duct 90. When assembled, a series of these rods 70 are positioned around the periphery of each end 90a and 90b of the rigid duct 90 at equi-spaced intervals. Prior to assembly, the rods 70 may be sealed in a plastic bag 30 that is attached to the rigid duct 90. Referring now to Figures 7 and 8, where a damper assembly 100 according to fourth exemplary embodiment is illustrated, in which the selectively employable guard means 110 take the form of a series of substantially rigid, tubular segments which are adapted to be deployed by being 35 telescopically extended with respect to each other and the rigid, tubular duct 104. A first segment 112 telescopes with respect to the rigid duct 104, and a second segment 114 telescopes with respect to the first segment 112.

Referring now to Figures 9 and 10, where a damper assembly 200 according to a fifth exemplary embodiment is illustrated. This damper assembly 200 comprises a rigid duct assembly, itself comprised of three portions of rigid duct, where end portions 202 of this assembly are adapted to 5 telescope relative a centre portion 204 to which the blade is pivotally mounted, so that the overall length of the rigid duct assembly can be selectively shortened or lengthened. Referring now to Figure 11, where a damper assembly 300 according to a sixth exemplary embodiment is illustrated. This damper assembly 300 comprises a rigid duct assembly, itself 10 comprised of three portions of rigid duct, where end portions 302 of this assembly form blade guard means that can be deployed by being selectively attached by way of snap fitting or the like to a centre portion 304 to which the blade is mounted. In this way the overall length of the rigid duct assembly 300 can be selectively shortened or lengthened as before, and the spigot size of the end portions 302 can be selected and or changed to suit requirements. 15 Referring now to Figures 12 and 13, where a damper assembly 400 according to a seventh exemplary embodiment is illustrated. In this exemplary embodiment, the blade guard means 410 takes the form of a pair of substantially rigid, arcuate elements (hereinafter strips) 412a and 412b, each of which arches from one side of one end 414a of the rigid duct 414 to the other side of that end, diametrically across 20 the opening in this end 414a. Each end of the arcuate strips 412a and 412b is pivotally attached to the rigid duct 414, so that each arcuate strip 412a and 412b may be rotated through approximately 90 degrees between a retracted position (as shown in Figure 12) and an extended position (as shown in Figure 13) relative to the end 414a of the rigid duct 414. In the retracted position, each arcuate strip 412a and 412b locates adjacent the end 414a of the rigid duct 414, in a position substantially normal to 25 the direction of elongation of the rigid duct 414. When the arcuate strips 412a and 412b are deployed by being extended, strip 412a passes around the outer edge of the other, inner strip 412b. When the two arcuate strips 412a and 412b are deployed, the inner element 412b releasably engages the outer element 412a in a slot formed between a pair of 30 spaced apart fingers 420 so that the two strips 412a and 412b support each other in their deployed positions. Referring now to Figure 14, which illustrates damper assembly 400 equipped with blade guard means 410 at both ends 414a and 414b thereof. 35 Referring now to Figures 15 through 17, where rotation of the blade 430 in rigid duct 414 of damper assembly 400 is, in this embodiment, effected by an electric motor, a housing of which 440 is connected to the rigid duct 414, and a drive shaft of which (not shown) is connected to the blade 430. 5 Referring now to Figure 18, where there is illustrated a damper assembly 500 which, together with another portion such as shown at 600, comprises damper assembly 400. A first end 500a of assembly 500 incorporates blade guard means 410, and a second end 500b is adapted for connection with a further component (component 600 in the case of assembly 400), this being a Y-shaped connector 450 in the case of Figure 18. 0 Throughout the specification and claims that follow it will be understood that the term "comprise" and any of its derivatives (eg comprises, comprising) as used in this specification is to be taken to be inclusive of features to which it refers, and is not meant to exclude the presence of any additional features unless otherwise stated or implied. 5 The reference to any prior art in this specification is not, and should not be taken as, an acknowledgement of any form of suggestion that such prior art forms part of the common general knowledge. '0 It will be appreciated by those skilled in the art that the invention is not restricted in its use to the particular application described. Neither is the present invention restricted in its preferred embodiment with regard to the particular elements and/or features described or depicted herein. It will be appreciated that various modifications can be made without departing from the principles of the invention. Therefore, the invention should be understood to include all such modifications in its scope. 25 11

Claims

1. A damper assembly comprising a blade pivotally mounted in a length of substantially rigid duct between a pair of ends of the rigid duct, so that the blade may be rotated about its pivotal mounting to a position where at least a portion of said blade extends beyond an end of the rigid duct, the damper assembly further comprising selectively deployable blade guard means adapted to prevent obstruction of the blade's operation by flexible ducting connected to the or each end of the substantially rigid duct equipped with said deployable blade guard means.

2. The damper assembly of claim 1, wherein the selectively deployable blade guard means comprise one or more substantially rigid elements that project from at least one end of the rigid duct when deployed.

3. The damper assembly of claim 1, wherein the selectively deployable blade guard means comprise a rigid duct of extendible length, so that the selectively deployable blade guard means are deployed by extending the extendible rigid duct.

4. The damper assembly of either of claims 1 or 2, wherein the or each rigid element is selectively attachable to and detachable from the substantially rigid duct, and is deployed by being attached to the rigid duct.

5. The damper assembly of either of claims 1 or 2, wherein the or each rigid element is adapted to extend and retract relative to the substantially rigid duct, and is deployed by being extended.

6. The damper assembly of claim 3, wherein the assembly comprises at least two portions of rigid duct adapted to telescope relative to one another.

7. The damper assembly of claim 4, wherein the or each rigid element is a further substantially rigid duct segment adapted to be attached to the or each end of the substantially rigid duct in which the blade is mounted.

8. The damper assembly of claim 4, wherein the or each rigid element is attached by way of snap fit or fasteners or the like.

9. The damper assembly of claim 5, wherein the or each rigid element is deployed by sliding or telescoping with respect to the substantially rigid duct.

10. The damper assembly of claim 5, wherein the or each rigid element is deployed by pivoting or rotating relative to the substantially rigid duct. 12

11. The damper assembly of claim 10, wherein the or each rigid element is of an arcuate shape which is pivotally attached at each end thereof to the substantially rigid duct so that the or each rigid element can pivot between an extended position and a retracted position.

12. The damper assembly of claim 11, wherein the selectively deployable blade guard means comprises two arcuate rigid elements pivotally connected to the substantially rigid duct at positions separated by 90 degrees.

13. The damper assembly of claim 12, wherein when the two arcuate members are deployed, one passes around the outer edge of the other element.

14. The damper assembly of claim 13, wherein when the two arcuate members are deployed, one element is adapted to releasably engage the other element so that the two elements support each other in their extended positions.

15. The damper assembly as in any one of the preceding claims, wherein at least one end of the damper assembly is adapted to be connected to either of flexible ducting or another HVAC fitting.

16. The damper assembly as in any one of the preceding claims, wherein there are two or more blades pivotally mounted in the length of substantially rigid duct, where these two or more blades act cooperatively to block the duct.

17. The damper assembly as in any one of the preceding claims, wherein this comprises selectively deployable blade guard means at each end of the substantially rigid duct.

18. The damper assembly as in any one of the preceding claims, wherein the blade is disc shaped, the rigid duct is tubular, and the length of the rigid duct is less than the diameter of the blade.

19. The damper assembly as in any one of claims 1 through 17, wherein the blade and rigid duct are of matching polygonal shapes.

20. The damper assembly of claim 19, wherein the blade and rigid duct are of matching rectilinear shapes.

21. The damper assembly as in any one of the preceding claims, wherein the rigid duct has a single inlet and a single outlet.

22. The damper assembly as in any one of claims 1 through 20, wherein the duct has multiple outlets, as a result of the duct dividing into a number of branches at a point downstream of the blade. 13

23. The damper assembly as in any one of claims 1 through 20, wherein the duct has multiple inlets, as a result a number of branches converging at a point upstream of the blade.

24. A damper assembly comprising a disc shaped blade pivotally mounted in a tubular housing between a pair of ends thereof, so that the blade may be rotated about its pivotal mounting to a position where at least a portion of said blade extends beyond both ends of the housing, the damper assembly further comprising selectively deployable blade guard means adapted to prevent obstruction of the blade's operation by flexible ducting connected to either end of the damper assembly.

25. A damper assembly substantially as herein described with reference to the accompanying illustrations. 14