WO2015128608A1

WO2015128608A1 - Duct system

Info

Publication number: WO2015128608A1
Application number: PCT/GB2015/050420
Authority: WO
Inventors: Karl SULLIVAN
Original assignee: Cosaf Environments Limited
Priority date: 2014-02-25
Filing date: 2015-02-13
Publication date: 2015-09-03
Also published as: GB201403246D0; GB2523395A

Abstract

A duct system comprises a sheet of material (7, 9) arranged to be formed into a conduit (3, 5) having a length and a join between two interfacing edges of the sheet material from which the conduit is formed, a bracket (17) shaped to receive each of the two interfacing edges so that at least part of the sheet material (7, 9) is covered by the bracket (17). The bracket (17) is arranged to extend along a substantial part of the length of the conduit (3, 5). A plurality of interconnectable sections (29, 31) are connectable together to form an end piece (27) shaped to receive at least part of an end of the conduit.

Description

DUCT SYSTEM

Technical Field of the Invention

The present invention relates to a duct system.

Background to the Invention Ducts are used in heating, ventilation and air-conditioning to deliver and remove air. Buildings often comprise many metres of ductwork to deliver and remove air to one or more rooms within the buildings. The use of ducts therefore permits the temperature and air quality of different parts of a building to be regulated without the need to provide direct exposure to the outdoor environment through, for example, windows. The ductwork also provides a useful protective conduit for building services such as electricity cables, water pipes and networking cables.

Galvanized mild steel is the most common material used in fabricating ductwork. Such ductwork may be lined internally with fibreglass material or wrapped externally with fibreglass blankets for insulation purposes. Problems with steel ductwork include that it is heavy, prone to vibration and therefore noise, expensive relative to other materials and relatively inflexible which means that it is difficult to manufacture complex cross sections and shapes. Since steel ductwork must usually be manufactured at the manufacturer's site, it is also difficult and bulky to transport.

It is an object of the present invention to provide an improved duct. Summary of the Invention

According to a first aspect of the present invention, there is provided a duct system comprising a sheet of material arranged to be formed into a conduit having a length and a join between two interfacing edges of the sheet material from which the conduit is formed, a bracket shaped to receive each of the two interfacing edges so that at least part of the sheet material is covered by the bracket, said bracket arranged to extend along a substantial part of the length of the conduit, the duct system further comprising a plurality of interconnectable sections that are connectable together to form an end piece shaped to receive at least part of an end of the conduit intended to be formed.

Advantageously, any conceivable shape or configuration may be assembled with a system according to the present invention. Since each of the elements of the duct are broken into component parts, they can be easily and cheaply transported and assembled on site.

The end piece may be arranged to engage with the bracket. The interconnectable sections may comprise a formation shaped to receive a part of the bracket. The bracket receiving formation and the bracket may each comprise mutually engaging formations that serve to limit movement of the bracket relative to the interconnectable section when the bracket is received by the interconnectable section.

The interconnectable sections may be arranged to form an end piece having an engagement means which is substantially the same shape as the end of the conduit intended to be formed. The interconnectable sections may each comprise a projection which, when the sections are connected to form the end piece, together form a receiving member for receiving an end of the conduit intended to be formed.

The interconnectable sections may each comprise a lip that, when the sections are connected to form the end piece, together form a flange. The interconnectable sections may comprise attachment means to permit each section to connect to a section of a different end piece.

The sections may each comprise a region on the flange that, when the sections are connected to form the end piece, together form a substantially continuous loop for receiving a gasket.

The sheet material may be paper based. The sheet material may comprise cardboard. The cardboard may be multi-walled. The cardboard may be a triple walled corrugated cardboard.

The sheet material may comprise weakened regions that permit the sheet material to be folded into a conduit of a desired three dimensional shape.

The duct system may further comprise a moisture resistant and/or fire retardant coating.

The plurality of interconnectable sections may comprise corner pieces and/or straight pieces and/or curved pieces. The end fitting or end piece formable from the interconnectable sections may comprise arms that grip an end of a duct. One side of the fitting may comprise opposed walls that are arranged to resiliently grip a duct and the other side may form a flange which is arranged to abut a flange of a corresponding end fitting.

The end fitting may further comprise a bracket which is arranged to hold together lateral sides of a duct and which is connectable to at least one separately formed component. According to a second aspect of the present invention, there is provided a kit of parts for forming the aforementioned duct system, the kit comprising at least one said bracket and at least one said plurality of interconnectable sections being connectable together to form a framework for a duct formed from a sheet of material.

The at least one bracket and/or the plurality of interconnectable sections may comprise corner pieces and/or straight pieces and/or curved pieces.

Detailed Description of the Invention

In order that the invention may be more clearly understood an embodiment thereof will now be described, by way of example only, with reference to the accompanying drawings, of which:

Figure 1 shows a perspective view of part of a duct assembly made from a duct system according to the invention;

Figure 2 shows an exploded perspective view of the part of the duct assembly shown in Figure 1 ;

Figure 3 shows an enlarged view of a part of the exploded assembly shown in

Figure 2;

Figure 4 is a plan view of a sheet of material used to form part of the assembly shown in Figure 1 ;

Figure 5 is a perspective view of the sheet of material shown in Figure 4 when in a folded state; Figure 6 shows an enlarged cross section of a type of sheet material shown in Figure 4;

Figure 7 shows an enlarged perspective view of a part of the assembly shown in

Figure 1; and

Figure 8 shows a cross section view of the part shown in Figure 7.

With reference to the drawings, there is shown a duct assembly 1 comprising two substantially square ducts 3, 5 that permit the conveyance of air. Each duct 3, 5 comprises a main body 7, 9 formed into a conduit from a sheet of cardboard material. The desired conduit shape is achieved by cutting appropriately positioned grooves into the sheet material to create weak points or hinges that permit the sheet material to be folded into a three dimensional conduit having openings at either end. In this particular embodiment, the square conduit 3, 5 is achieved by cutting three 45 degree grooves 1 1 into the sheet material along its length at equally spaced positions across the width of the sheet material to create three substantially parallel fold lines or hinges. The sheet material 7 is then folded along these lines to create a square shaped conduit with two interfacing edges 13, 15. Other three dimensional shaped conduits can be formed in a similar way by using an appropriately shaped sheet of material and appropriately placed fold lines.

The sheet material comprises a triple walled corrugated cardboard which provides increased strength and durability. The grooves are cut into two of the layers to enable the cardboard to be easily folded. One of the layers is left intact to maintain strength along the fold line. To improve the suitability of cardboard material for ductwork, the cardboard is coated with a fire retardant and moisture resistant, hydrophobic material. Each of the ducts 3, 5 further comprises a connecting bracket 17 made from extruded plastics material which extends along at least a substantial part of the length of the conduit 7, 9. The bracket 17 comprises two substantially equal lengths of material each having substantially perpendicular arms which form an L-shaped cross-section. The arms of one of the L-shaped pieces 19 are longer than the arms of the other L-shaped pieces 21. The two L-shaped pieces 19, 21 are offset from one another with the larger piece 19 arranged outside the smaller piece 19 such that the arms of each piece 19, 21 extend to a common plane respectively. The two pieces 19, 21 are linked by a central spine 23 which holds the two pieces 19, 21 in a spaced apart relationship. The distance between the arms of the two pieces 19, 21 are substantially equal to the thickness of the sheet of material from which the conduits 7, 9 are formed so that the gaps between the two pieces 19, 21 can receive an end of the sheet material in a tight fit. A pair of spaced apart ridges or teeth 25 extends from the inner surface of each arm and are arranged to bite into the sheet material to help keep the material wedged between the arms of the respective pieces 19, 21.

The bracket 17 is arranged to receive each edge 13, 15 of the sheet material 7 to hold the sheet material in its three dimensional form. One edge 13 is inserted into the gap between one set of arms and the other edge 15 is inserted into the other gap between the two arms so that the bracket 17 forms a right angle between the two sides. The shape of the arms and gaps of the bracket are therefore chosen to create the desired shaped join between the two interfacing sides of the conduit 7, 9. Thus, for example, if a circular conduit is alternatively desired, the arms and, hence, gaps of the bracket 17 may take a curved form substantially equivalent to the curvature of the desired conduit. When the sheet material is connected to the bracket, the bracket forms a mechanical, substantially air-tight seal along the join between the two edges.

Each duct 3, 5 further comprises an end piece 27 comprising a plurality of interconnected component parts. Each part is made from extruded plastics material and is shaped such that, when an appropriate mix of component parts is joined together, they form an end piece 27 that matches the end of the conduit 7, 9. Since the conduits in this embodiment are square shaped in cross section, the end piece comprises four corner parts 29 and four straight interconnecting parts 31. Each part comprises either a male projection 33 or a female groove 35 which are positioned such that, when two parts are connected together, the male 33 of one part 29 fits into the female 35 of the other part 31 to connect and hold the two parts 29, 33 together. The interconnectable parts can therefore be joined together using a push fit system.

Each part 29, 31 comprises two substantially parallel spaced apart walls 37, 39 which are dimensioned to receive an end of the conduit 7, 9. Thus, as with the bracket, the distance between the two walls 37, 39 is chosen to be substantially equal to the thickness of the sheet material so that the conduit is held between the walls 37, 39 in a tight fit. The inner surfaces of the walls 37, 39 have teeth like projections to bite into and grip hold of the conduit sides when inserted therebetween.

The component parts 29, 31 each have a platform section 41 which extends substantially perpendicularly from the two walls 37, 39. The platform 41 is arranged to extend beyond the outer wall 39 of the component parts to form a lip 43. When the component parts are connected together to form the end piece 27, the platforms 41 of each part 29, 31 together form a substantially continuous flange which may be urged against the flange of a corresponding piece as shown in Figure 1. The corner parts 29 each have both holes 45 and studs 47 formed in the lip 43 and are positioned to be inserted into the holes or to receive the studs of a corresponding corner part so that two corresponding end pieces can be connected and held firmly together. A clip 49 extends from the inner edge of each platform of each corner piece 29 and is arranged to hook around a small ridge 51 on the inner edge of the platform of a corresponding part of an adjacent end piece 27, thereby to further enhance the bond between the two end pieces when connected together.

Each platform 43 of each part 29, 31 comprises a shallow recess 53 which is positioned such that, when the part 29, 31 are connected together, they form a substantially continuous recess around the flange of the end piece. The recess provides a seat for a gasket which is sandwiched between two corresponding end pieces 27 when attached together. The gasket helps ensure an air tight fit between two corresponding ducts 3, 5.

One of the component parts 29 comprises an enlarged cavity 55 which is shaped to receive an end of the bracket 17. The inner surface of this component part 29 comprises teeth 57 which are arranged to engage the inner piece 21 of the bracket 17 and prevent lateral movement of the bracket relative to the cornier part 29. When the bracket 17 is inserted into the cavity 55, it is held securely in place with a tight fit.

To create a duct assembly of a desired configuration, the number of ducts and their corresponding shape is determined. A corresponding number of sheets of cardboard are cut to size and shape and scored to create appropriately positioned fold lines. The sheets are then folded into the desired three dimensional shapes and two opposite edges are drawn together to create a join. Depending upon the shape of the conduit formed, an appropriately shaped bracket is moulded from plastics material and cut to size so that its length substantially equals the length of the join. One edge of the conduit is inserted into one of the bracket gaps and the other edge is inserted into the opposite gap such that two sides of the conduit extend partially into the bracket and are held in place. Adhesive may additionally be used to enhance the body between the bracket and the sheet material and ensure that the conduit is held in the desired shape.

Depending upon the shape of the end of a particular conduit, a number of component parts for an end piece are chosen and connected together to form a corresponding shape. In the case of a square conduit, four corners and four straight parts may be used. In the case of a circular conduit, four curved parts may be used and connected together. Other shapes are possible by using appropriate curved or straight pieces. When the desired end piece shape has been achieved, the edges of the end of the conduit are inserted into the walls 37, 39 of the end piece 27 and held firmly in place. Again, adhesive may be used to strengthen the connection between the two. The end piece is oriented so that the bracket 17 is received by the cavity 55 of the appropriate component part. End pieces are provided at either end of the conduit to form a duct. A gasket is adhered to each end piece within the recess 53 provided.

When all ducts have been assembled as above, the correct sequence of ducts are joined together via their cooperating end piece connections 45, 47, 49 to form the desired ductwork configuration. The interfacing gaskets between the respective ducts ensure an air tight seal so that air is conveyed from one end of the ductwork to the other without leakage. The above embodiment is described by way of example only. Many variations are possible without departing from the scope of the invention as defined in the appended claims.

Claims

A duct system comprising a sheet of material arranged to be formed into a conduit having a length and a join between two interfacing edges of the sheet material from which the conduit is formed, a bracket shaped to receive each of the two interfacing edges so that at least part of the sheet material is covered by the bracket, said bracket arranged to extend along a substantial part of the length of the conduit, the duct system further comprising a plurality of interconnectable sections that are connectable together to form an end piece shaped to receive at least part of an end of the conduit intended to be formed.

A duct system as claimed in claim 1, wherein the end piece is arranged to engage with the bracket.

A duct system as claimed in claim 2, wherein one of the interconnectable sections comprises a formation shaped to receive a part of the bracket.

A duct system as claimed in claim 3, wherein the bracket receiving formation and the bracket each comprise mutually engaging formations that serve to limit movement of the bracket relative to the interconnectable section when the bracket is received by the interconnectable section.

A duct system as claimed in any preceding claim, wherein the interconnectable sections are arranged to form an end piece having an engagement means which is substantially the same shape as the end of the conduit intended to be formed.

6. A duct system as claimed in any preceding claim, wherein the interconnectable sections comprise respective projections which, when the sections are connected to form the end piece, together form a receiving member for receiving an end of the conduit intended to be formed.

7. A duct system as claimed in any preceding claim, wherein the interconnectable sections comprise respective lips that, when the sections are connected to form the end piece, together form a flange.

8. A duct system as claimed in claim 7, wherein the interconnectable sections comprise attachment means to permit each section to connect to a section of a different end piece.

9. A duct system as claimed in claim 7 or claim 8, wherein the sections each comprise a region on the flange that, when the sections are connected to form the end piece, together form a substantially continuous loop for receiving a gasket.

10. A duct system as claimed in any preceding claim, wherein the sheet material is paper based.

11. A duct system as claimed in claim 10, wherein the sheet material comprises cardboard.

12. A duct system as claimed in claim 11, wherein the cardboard is multi-walled.

13. A duct system as claimed in claim 12, wherein the cardboard is a triple-walled corrugated cardboard.

14. A duct system as claimed in any preceding claim, wherein the sheet material comprises weakened regions that permit the sheet material to be folded into a conduit of a desired three-dimensional shape.

15. A duct system as claimed in any preceding claim, further comprising a moisture resistant and/or fire retardant coating.

16. A duct system as claimed in any preceding claim, wherein the interconnectable sections comprise corner pieces and/or straight pieces and/or curved pieces.

17. A duct system as claimed in any preceding claim, wherein the interconnectable sections form an end piece that comprises arms arranged to grip an end of a conduit formed from the sheet material.

18. A duct system as claimed in any preceding claim, wherein the interconnectable sections are arranged to form an end piece, wherein one side of the end piece comprises opposed walls arranged to resiliently grip a duct, and wherein the other side forms a flange arranged to abut the flange of another said end piece.

19. A kit of parts for forming a duct system according to any preceding claim, the kit comprising at least one said bracket and at least one said plurality of interconnectable sections being connectable together to form a framework for a duct formed from a sheet of material.