AU2007202145B2

AU2007202145B2 - Duct connector with leak proof seal

Info

Publication number: AU2007202145B2
Application number: AU2007202145A
Authority: AU
Inventors: William James Donnelly
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-05-14
Filing date: 2007-05-14
Publication date: 2013-05-16
Anticipated expiration: 2027-05-14
Also published as: AU2007202145A1

Abstract

A connector or spigot means specifically for attaching round flexible ducting used in ducted heating, air conditioning and ventilation systems to other lengths of flexible ducting, system distribution components and air grills and diffusers wherein 5 the means to provide an assured leak-proof connection is provided. Generally, the connector is of cylindrical formation with a hollow tapered entry portion, a stable portion including a series of profiled ramp formations, a reduced diameter adhesive application platform, an application of extruded adhesive profile to the said platform, a rear stable portion terminating at a flange, provision for a pair of semi circular 10 hollow protection devices to be secured to the connector means to protect the adhesive means during transport and storage and a dual purpose belt means to secure the protective device means and secondly to provide added security to an affixed flexible duct. In these circumstances, the outer diameter of the adhesive profile exceeds the inside diameter of the attaching flexible duct forming a leak-proof air seal on 15 completion. The flexible duct is drawn to the rear placed flange, disturbing the profile of the adhesive and causing an uninterrupted cylindrical bond between the inner diameter of the flexible duct and the connector means. The protection device may be discarded and the dual purpose belt means applied to the outer diameter of the flexible duct to provide short term security and appearance attributes. 25 INVENTOR: William James Donnelly 2/97 Hawdon Street Heidelberg 3084 Victoria 30 AUSTRALIA -fl "'S

Description

DUCT CONNECTOR WITH LEAKPROOF SEAL PRIOR ART 5 Ducted heating and air conditioning is installed in a wide variety of constructions designed for living or working spaces. The majority are connected to an appliance generating a conditioned air source via a series of ducts and distribution connectors including air grills and diffusers. This invention relates to an improved connector for attaching flexible ducting duct to in-line connectors, branch connectors, 10 line reducers and the connector portion for assembling flexible duct to air grills and diffusers. In some markets, connector portions may be termed spigots or spigot portions. For economic and environmental reasons, energy efficiency within these systems, which absorb significant percentages of energy employed within living and 15 working structures, is now much more critical. In many widespread surveys conducted in USA and elsewhere, air leakage at duct connection points is known to contribute a significant portion of energy wastage. For example, the USA Department of Energy has concluded that the average residential ducted heating and/or air conditioning system wastes 35% of the energy entering a duct system from the 20 appliance. One known common means of making a connection between lengths of flexible duct and other system components is the provision of a plain connector (or spigot portion) in the form of a short hollow cylindrical portion protruding from the component. The flexible duct is drawn over the connector and secured by means of 25 duct tape. Many duct tapes have proven unreliable over the life of a duct system causing significant leakage upon failure or poor application during installation. Australian patents 698481 (1995) and 768552 (2000) describe duct connectors with an in-built rubber or synthetic seal engage-able with the inside surface of a fitted flexible duct to reduce air leakage and clips to retain the duct wall to the connector. 30 SUMMARY OF THE INVENTION It is therefore an object of this invention to provide an improved connector with assured leak-proof capability and also capable of employing automated production techniques for efficient lower cost outcomes. 1 2 It is a further object of the invention to provide a connector that can overcome many disadvantages experienced by installation contractors working in confined spaces where the physical application of duct tape may be space restricted or where visual confirmation of accurate application of duct tape to secure a joint is not 5 possible. It is a still further objective of this invention to provide consumers, building contractors, building code enforcement officers, appliance producers and other interested parties with comprehensive assurances that a duct system employing the connector so invented is leak-proof. 10 Generally a connector or spigot portion is an integral portion of a ducted system component provided to allow connecting flexible duct to be assembled within a conditioned air delivery system. Commonly employed components with one or more connectors include single and double 'T' branch connectors, 'Y' branch connectors, double ended duct joiners, duct inline reducers, flanged connectors for connecting 15 flexible duct to plenum chambers or entry connectors to grills and diffusers for passing conditioned air into the conditioned space. According to one aspect of the invention there is provided a connector portion integrally moulded in polymer materials forming the entry or exit connection for attaching flexible duct to each particular component so being attached, comprising: 20 A tapered, generally round, hollow entry port for ease of accessing the open end of a connecting length of flexible duct; A forward parallel stable portion being of tolerance outside diameter to the inner diameter to the incoming flexible duct; An adhesive application platform portion of lesser diameter, or valley trough 25 appearance, whereon one or more parallel or helical rotations (preferably two or more) of a soft bead formation of adhesive may be laid such that the outer bead diameter surface exceeds the inside diameter of the incoming flexible duct; An adhesive portion, preferably of generally contact type with soft and manipulable characteristics similar to many adhesives available in the automobile 30 industry for sealing and bonding. Preferably the adhesive is applicable with mechanical dispensing means in continuous bead or round formation (similar in appearance to toothpaste as extruded from a standard tube) and suitable for application to the adhesive platform portion manually by parallel or helical rotations, or by programmable robotic means; 2 A rear stable portion, of generally parallel cylindrical formation approximating a tolerance outer diameter supporting the inner diameter of an incoming flexible duct; A flange portion abutting the rear stable portion defining the extent to which flexible duct may be drawn on to the connector means; 5 Two or more rising surface protrusion portions to facilitate retention of the incoming flexible duct as adhesive deployment of the adhesive means reacts to permanently secure the flexible duct to the connector means; A pair of annular groove formations placed at the extremities of the adhesive platform portion to accommodate an adhesive material protection device provided to 10 ensure ease of transport and handling of the connector, from the point of manufacture to the point of installation. A pair of half circular, channel shaped adhesive material protection portions designed to snugly fit to the annular groove formations such that in deployed circular placement (of two portions in full circular fitment) the adhesive material within is 15 protected during transport, distribution and on building sites prior to actual connection to flex-duct. The outer top wall of the channel formation, of the half circular adhesive material protection devices, has an annular recess of lesser diameter, provided for fitment of a restraining and retaining belt portion to secure the half circular portions to the connector means within the annular grooves placed at the extremities of the 20 adhesive platform portion; A dual-purpose belt formation portion designed with a first purpose of restraining the two portions half circular adhesive protection portions to the connector means until installation and a second purpose of providing a finishing and securing means of the outer diameter of the affixed flex-duct to the connector means; 25 According to another aspect of the invention, the connector means is deployed in field installations by disengagement of the belt formation portion that allows easy removal of the two half-circular adhesive protection portions. The incoming flex-duct may then be drawn towards the flange portion passing over the tapered entry portion, forward stable portion, the adhesive portion and the rear stable portion. 30 As the top surface of the applied adhesive is of greater diameter than the inner diameter of the incoming flexible duct, the soft upper surface engages with the internal surface of the ducting and is drawn forward against the resistance of the lower surface bonded to the platform portion of the connector means. The flexible duct is drawn forward to the flange portion, passing across the rear stable portion allowing a 3 4 spread of adhesive material between the engaging surfaces of the flexible duct and the connector. In circumstances where particularly high tack adhesives are preferred, an inert surfacing of lubricant may be applied over the adhesive to facilitate ease of drawing the flexible duct over the adhesive, displacing the lubricant and deploying the 5 adhesive affect after the passage of the flexible duct towards the terminal position at the flange portion. One preferred alternative means of easing the installation of the flexible duct to the connector portion over the adhesive portion, is a disposable application of treated paper strip with a silicon surface applied over the adhesive that simply draws forward 10 with the flexible duct as it is drawn towards the flange portion. Further, the flexible duct is drawn across the protrusion portions preferably of narrow ramp formation with rearward facing vertical wall drop forcing the generally included helical wire reinforcement of the flexible duct member to flex and contract over the protrusion portions causing restraint. 15 In these circumstances the adhesive material forms a permanent engaging seal and bond between the duct wall and the connector so described. Further in these circumstances and following the completed insertion of the connector within the flexible duct means, The retaining and restraining belt device (previously employed to restrain the pair of half circular adhesive protection portions) 20 may be redeployed to provide, for example, retention of an insulation medium and outer sheath of a flexible duct means in situ over the connector within. Generally, after flexible duct has been fitted to a connector, elements of exposed insulation and/or outer sheath coverings appear untidy and the dual-purpose belt device is ideally employed to make good the appearance of the connection in lieu of duct tape 25 or other less reliable means. BRIEF DESCRIPTION OF DRAWINGS Figure 1 is a side sectional view of the connector means, including detail in accordance with the invention, without the adhesive portion. Figure 2 is a side sectional view of the connector means as in figure (1) and 30 including the adhesive material portion. Figure 3 is a side sectional view of flex-duct fitted to the connector means. Figure 4 is an isometric view of the adhesive protection cover device and securing belt device in accordance with the invention. 4 5 Figure 5 is an isometric side sectional view of the adhesive protection cover device as fitted to the connector means at the point of production. Figure 6 is an isometric side sectional view of the dual purpose belt device as applied after flexible duct is deployed on the connector means to provide as an outer 5 retaining and finishing device. EMBODIMENTS OF THE INVENTION Figure 1 is a side elevation of the preferred embodiment of the invention depicting the connector means without the adhesive portion, wherein (1) is the entry port allowing air to pass through the connector. Exit port (2) defines the hollow nature 10 of the connector means and it will be understood that depending on the nature and direction of the connector means within the system design, the entry port (1) and the exit port (2) are interchangeable as to air direction. Tapered portion (3) is provided to assist in the ease of inserting the connector means to incoming flex-duct. Forward stable portion (4) is provided to allow the flex-duct to stabilise as it advances towards 15 adhesive platform (5) and protrusion portions (6) are provided with a ramp formation and rear vertical wall formation (both not shown in detail) to entrap advancing helical wire reinforcement within the advancing flex-duct wall to assist restraint. Adhesive platform (5) is provided with a lesser diameter than the forward stable portion (4) and the rear stable portion (7) to provide a suitable location for applied adhesive as 20 described in figure 2. Rear stable portion (7) abuts flange portion (8) to allow the incoming flex-duct to stabilise and nestle snugly against flange portion (8) to complete insertion. Two annular grooves (9) are provided at the forward and rear extremities of adhesive platform (5) to accommodate fitment of adhesive protection devices described in 25 figure 3. Referring to figure 2, the form of the connector means is similar to the description outlined in figure 1. Additionally, adhesive portion (10) has been applied to adhesive platform portion (5) of figure 1. Adhesive portion (10) in this iteration has (theoretically) been applied to adhesive platform (5) of figure 1, via a designed 30 applicator simultaneously extruding three round solid tubular formations of adhesive material attached to a robot arm means. It will be understood by those familiar in the art of applying adhesives that a variety of shapes and means of adhesive application are available, including a single extruded form or other applied means. 5 6 It can be clearly seen location points (11) that the outer diameter of adhesive portion (10) exceeds the outside diameter of both forward stable portion (4) and rear stable (7) of figure (1). Ideally, the outer diameter of stable portions (4 & 7) are a tolerance dimension for inner diameter of incoming flex-duct such that adhesive 5 portion (10) is forced to attach to the inner diameter of the flex-duct and, being of soft and pliable consistency, re-shape itself to a permanent sealing and bonding condition. Referring now to figure 3, insulated flex-duct (12) has been drawn over the connector means forward over tapered portion (3), forward stable portion (4) including protrusion portions (6), adhesive portion (10) laid on adhesive platform (5), 10 rear stable portion (7) and terminating at flange portion (8). Ideally, the cubic space occupied by adhesive portion (10) exceeds the cubic space of adhesive platform (5) and the sidewall of flex-duct (12), such that in drawing flex-duct (12) forward, adhesive portion (10) is forced to 'spill' beyond the borders of adhesive platform (5) thus ensuring further leak-proof sealing and bonding of the flex-duct to the connector 15 means. Referring to figure 4, a pair semicircular moulded channel shaped adhesive protection portions (13) (now referred to as adhesive protection portions (13)) are designed with a recessed portion (14) on the outer top surface to accommodate fitment of retaining and restraining belt device (15). (Now referred to as the retaining belt 20 device (15)). Retaining belt device (15) is fitted with tongue and buckle portions (16) to allow fitting and release of the retaining belt device (15) in the first instance as a restraint for adhesive protection portions (13). In these circumstances, a pair of annular grooves (9) of figure 1 are provided at the extremities of adhesive platform (5) of figure I to accommodate a snug fitment of the adhesive protection devices (13) 25 after adhesive portion (10) of figure 2 has been applied. Figure 5 depicts the adhesive protection portions (13) fitted to annular grooves (9) of the connector means. Retaining belt device (15) is fitted within recessed portion (14) of figure 4 and secured via tongue and buckle portions (16). It will be recognised by those skilled in the art of belting and securing devices that tongue and buckle 30 portions (16), within the spirit of this invention, may be replaced by a range of semi permanent self-adhesive strips, interactive bonding or magnetic strips, etc. According to one aspect of the invention, adhesive portion (10) is securely protected until the retaining belt device (15) and adhesive protection portions (13) are removed at the time of field installation. 6 7 Referring to figure 6, flex-duct (12) has been drawn over the connector means from tapered entry portion (1) to flange portion (8) with retaining belt device (15) employed in the alternative category as providing security and a 'finishing' appearance to the exterior surface (usually an insulation blanket enclosed within an 5 outer sheath) of the flex-duct after fitment to the connector means. Ideally, retaining belt device (15) is deployed above the inner surface of rear stable portion (7) of the connector means. 7

Claims

1. A round connector or spigot for attaching flexible air conditioning ducting to various other air delivery system components, including: 5 A hollow entry port; A tapered portion to ease fitment of incoming flexible duct; A forward stable portion; An adhesive platform portion having a lesser diameter than the forward and rear stable portions; 10 A measure of applied adhesive compound provided to secure the flexible duct to the connector; A rear stable portion; One or more shaped protrusions providing restraint of the flexible duct to the connector; 15 A flange or abutment portion defining an end position of a connecting flexible duct; An adhesive protection device to prevent spoilage of the adhesive material during transportation and handling of the connector, prior to installation; A pair of annular grooves encircling the connector body to provide location and fitment of the adhesive protection device; 20 A retaining belt device having a first purpose of securing the adhesive protection device to the connector and a second purpose of being applied to flexible duct after fitment for assisting the securing of the flexible to the connector or spigot; A hollow exit port.

2. A connector or spigot according to claim I manufactured in polymer or metal 25 materials.

3. A connector or spigot according to claims 1-2 forming an entry or exit connection for flexible duct to air delivery system components including 'Y' and 'T' branch connectors, in-line duct joiners, line reducers, plenum boxes and boots, air diffusers and grills. 30

4. A connector or spigot according to claims 1-3 wherein the outside diameter of the forward and rear stable portions of the connector is a tolerance dimension to the inside diameter of incoming flexible duct. 9

5. A connector or spigot according to claims 1-4 manufactured in a range of sizes to accommodate available sizes of commercially available flexible duct.

6. A connector or spigot according to claims 1-5 wherein the adhesive platform portion may be shaped to accept applications of adhesive as commercially available pre 5 prepared profiles of extruded profiles.

7. A connector or spigot according to claims 1-6 wherein the adhesive platform portion may comprise an inward annular groove designed to accommodate a solid tubular profile of adhesive of paste consistency such that the outer diameter of the applied adhesive exceeds the inside diameter of incoming flexible duct. 10

8. A connector or spigot according claims 1-7 wherein the adhesive platform portion comprises an inward annular groove designed to accommodate an extruded profile of adhesive material of non-tubular shape.

9. A connector or spigot according to claims 1-8 wherein the annular grooves provided to affix an adhesive protection device may be located on the forward and rear stable 15 portions in circumstances where the application of the adhesive material portion occupies the outer dimensions of the adhesive platform portion.

10. A connector or spigot according to claims 1-9 wherein the adhesive protection device consists of a pair of semi-circular channel shaped formations forming full circular when the extending edges of the vertical sidewalls are located within annular grooves 20 provided on the body of the connector or spigot.

11. A connector or spigot according to claims 1-10 wherein the adhesive protection device more particularly described in claim 10, comprising a pair of semicircular channel formations further include one or more fixing portions on the outer horizontal wall forming the channel shape to snugly and accurately affix the retaining belt 25 device of claim 1.

12. A connector or spigot according to claims 1-11 wherein the adhesive protection device comprises a pair of semi-circular channel shaped formations further manufactured to include clip fixings to allow full circular fitment to the body of the connector or spigot in trade circumstances where the retaining belt device is not 30 required. 10

13. A connector or spigot having the embodiments of claims 1-12 of the invention so described and offering a permanent and assured leak-proof attachment of the connector means to attaching flexible duct means.