Introduction

This invention relates to a draft excluder and in particular to a chimney draft excluder adapted to conform to the size and/or shape of a chimney.

Background of the Invention

Draft proofing is one of the cheapest and most efficient ways to save energy in any type of building. One of the main causes of drafts in a domestic building is caused by an unused chimney as the chimney provides an easy route for hot air to exit the building. It has been estimated that up to 30% heat loss in a room can take place through an open un-used chimney. As a result of the egress of hot air, the pressure in the building can drop, resulting in cold air being drawn in from the exterior of the building through any available path to create cold drafts. In addition, an open chimney provides an additional route for cold air to enter a house.

Various attempts have been made to counteract chimney drafts. For example chimney cowls can be fixed to the top of the chimney to prevent wind or cold air from causing a back draft down the chimney when a fire is lit. However, when the fireplace is not in use, cowls exacerbate heat flow up the chimney giving rise to cold drafts. In addition, due to its position on top of a chimney, a cowl is difficult and expensive to install. Cowls are also difficult to close when not in use. Chimney clampers are also employed to counteract chimney drafts. A chimney damper is made up of a valve placed at the top of a chimney having a long metal chain that extends into the fireplace to allow a user to open and close the chimney damper from the fireplace. However, chimney dampers are expensive and difficult to install. Moreover, chimney dampers can pose a safety hazard as it is not possible for a user to easily determine whether the chimney damper is in the open or closed position so that a fire can be accidentally lit even where the chimney damper is closed.

An alternative solution to chimney drafts has been the use of inflatable devices. The inflatable device is inserted into the chimney in a deflated form and then inflated, thereby sealing the chimney and preventing the flow of air either up or down the chimney.

However, in use, inflatable devices may disturb soot in the chimney causing it to become dislodged when the device is deflated resulting in damage to the interior of a building. In addition, the presence of an inflatable device may not be apparent to a user so that if a fire is accidentally lit when the device is in-situ, the air in the device can heat up, become pressurized and burst causing soot and the like to be displaced.

Moreover, unknown to a user, an inflatable device can snag and deflate due to the presence of rough surfaces in the chimney while the device must also be re-inflated at regular intervals. In some instances, householders have attempted to completely seal chimneys with improvised devices. However, complete sealing of chimneys without expert advice can be dangerous where it is necessary to maintain at least some air flow for ventilation purposes.

Various other attempts have been made to counteract chimney drafts. For example, US Patent Specification Nos. 4.236,499, 5,301 ,655 and 6,748,943, British Patent Specification Nos. 734,338 and 760,696 and Canadian Patent Specification No. 1 ,192,459 all describe complex mechanical fittings directed at chimney drafts.

However, all the devices and methods of the prior art suffer from some if not all of the problems outlined above i.e. they are difficult or complex to install, are size specific, difficult to use, can seal a chimney completely and are difficult to remove or can present safety hazards if a fire is inadvertently lit when the device is in-situ.

Summary of the Invention

According to the invention there is provided a chimney draft excluder comprising a draft excluding plate insertable in a chimney flue; the draft excluding plate having a skirt adapted to conform to the size and/or shape of the chimney flue to close the flue.

Preferably, the skirt comprises a deformable skirt. More preferably, the deformable skirt comprises a plurality of elongate members. Advantageously, the elongate members comprise flexible tines for gripping the chimney flue.

Preferably, the flexible tines comprise at least one fold line to allow bending of the tines about the fold line.

In a preferred embodiment of the invention, the skirt comprises an inner skirt and an outer peripheral skirt, the outer peripheral skirt being contiguous and co-operable with the inner skirt to adjust the dimensions of the draft excluding plate in

accordance with chimney size.

Advantageously, the draft excluder further comprises a support arm attached to the draft excluding plate. Preferably, the support arm is attached to a grate box for occupying a fireplace grate.

Suitably, the chimney draft excluder further comprises a failsafe mechanism to detach the draft excluding plate from a chimney flue in the presence of fuel.

Preferably, the failsafe mechanism comprises a collapse mechanism to collapse the chimney draft excluder under contact with fuel. More preferably, the collapse mechanism comprises at least one fold line on the support arm for collapsing the support arm under fuel weight.

Most preferably, the collapse mechanism comprises at least one fold line on the grate box for collapsing the grate box under fuel weight. In one embodiment of the invention, the chimney draft excluder comprises a vent in the draft excluding plate. Preferably, the vent comprises an adjustable vent.

Suitably, the chimney draft excluder is formed from a flammable material.

Preferably, the flammable material comprises a cardboard material.

Advantageously, the cardboard material is at least partially laminated.

In another embodiment of the invention, the draft excluder further comprises a deformable trim attachable to the draft excluding plate to increase the size of the draft excluder. Preferably, the deformable trim comprises a plurality of elongate members and, more preferably, the elongate members comprise flexible tines for gripping the chimney flue.

In yet a further embodiment, the draft excluder further comprises a sealing component to seal the chimney flue.

The invention also extends to a blank for assembly into a chimney draft excluder, the blank comprising a bottom blank having a draft excluding plate portion and a skirt on the draft excluding plate portion adapted to conform to the size and/or shape of a chimney flue.

Suitably, the blank further comprises a top blank attachable to the bottom blank and a support arm portion, the support arm portion having fold lines to fold the support arm and support the draft excluding plate. Preferably, the top blank includes a draft excluding plate portion and a skirt on the draft excluding plate portion adapted to conform to the size and/or shape of a chimney flue, the draft excluding plate portion of the bottom blank and the draft excluding plate portion of the top blank together forming a draft excluding plate, the skirt on the draft excluding plate portion of the bottom blank forming an outer peripheral skirt on the draft excluding plate and the skirt on the draft excluding plate portion of the top blank forming an inner skirt on the draft excluding plate, the outer peripheral skirt and the inner skirt being contiguous and co-operable to adjust the dimensions of the draft excluding plate in accordance with chimney size.

Advantageously, the support arm portion is foldable about the fold lines to form a grate box for occupying a fire grate. Preferably, the support arm portion comprises an upper fold line and a lower fold line to define a grate box top panel therebetween and a foldable reinforcing tab for reinforcing the top panel. More preferably, the support arm portion comprises a glue receiving tab for forming the grate box.

In a preferred embodiment of the invention, the skirt comprises a deformable skirt.

Preferably, the deformable skirt comprises a plurality of elongate members and, more preferably, the elongate members comprise flexible tines cut into the blank.

Suitably, the flexible tines comprise at least one fold line to allow bending of the tines about the fold line. The draft excluder of the invention is adapted to conform to chimneys of varying sizes and shapes to ensure a tight-fit within the chimney whilst at the same time being provided with an optional vent to increase airflow if required. The deformable skirt of the draft excluder of the invention can accommodate variations in the dimensions and shape of chimneys whilst also effecting a tight-fit within chimneys and gripping chimney flues to fix the draft excluder in position in the flue.

The draft excluder of the invention prevents heat loss up chimneys, prevents upward and downward drafts and retains warmth in a building. The draft excluder also serves to reduce audible external noise levels whilst at the same time being easily installed and removed from a chimney without requiring the use of tools or expert installers. The draft excluder can be re-used and, as it can be formed from cardboard, re-cycled as required.

In its most basic form, the draft excluder of the invention can be made up of the draft excluding plate with skirt which can be used on its own to close off the chimney flue. However, to render the draft excluder visible i.e. for safety reasons, the draft excluder of the invention preferably incorporates the support arm and/or the grate box.

Accordingly, in use, the draft excluder is visible to a user so that the risk of inadvertently lighting a fire when the draft excluder is installed is reduced

significantly. In addition, in the event that a fire is set with the draft excluder in-situ, the draft excluder is provided with a collapsing failsafe mechanism to open the draft excluder and permit smoke to pass up the chimney. In a preferred embodiment, the draft excluder is formed from cardboard so that the draft excluder simply combusts in the grate without causing damage in such circumstances.

The draft excluder of the invention is effective at excluding drafts up and down a chimney by forming a secure and tight fit within the chimney flue without completely sealing the chimney. However, if desired, it is envisaged that the draft excluder of the invention could be adapted to form a seal within a chimney. Accordingly, the draft excluder of the invention could be adapted to control the level of draft exclusion up to 100% draft exclusion if desired.

Brief Description of the Drawings

The invention will now be described, by way of example only, with reference to the accompanying drawings in which:

Figure 1 is a perspective view from above and one side of a first embodiment of a draft excluder of the invention formed from a blank made up of a first or bottom blank and a second or top blank folded to define a draft excluding plate, a support arm and a grate box;

Figure 2 is a plan view from above of the bottom blank of the draft excluder of Figure 1 ;

Figure 3 is an enlarged plan view from above of the top skirt cut frets or tines and side skirt cut tines of Figure 2; Figure 4 is a plan view form above of the top blank of the draft excluder of Figure 1 with the grate box unassembled;

Figure 5 is an enlarged plan view from above of the top skirt cut tines and side skirt cut tines of Figure 4;

Figure 6 is a perspective view from above and one side of the assembled grate box of the draft excluder in a first conformation;

Figure 7 is a perspective view from above and one side of the assembled grate box of the draft excluder in a second conformation;

Figure 8 is a perspective view from above and one side of the assembled grate box of the draft excluder in a third conformation;

Figures 9 to 14 are perspective views from above and one side of the draft excluder of Figure 1 being installed in a chimney by a user;

Figure 15 is a plan view from above of the top blank of a second embodiment of the invention for use with fixed fuel supplies such as gas fires in which the grate box is replaced by an elongate tear strip which covers the gas fire coals;

Figure 16 is a perspective view from above and one side of a third

embodiment of a draft excluder of the invention in which the bottom blank is in the form of a back ply secured to the top blank by tabs and the grate box is omitted so that the support arm holds the draft excluding plate in situ in a fireplace;

Figure 17 is a perspective exploded view from above and one side of the draft excluder of Figure 16 in which the back ply is removed from the top blank to more clearly illustrate the back ply;

Figure 18 is a plan view from above of the top blank of the draft excluder of Figures 16 and 17;

Figure 19 is a perspective view from above and one side of a fourth

embodiment of the draft excluder of the invention in which the back ply of Figures 16 to 18 is augmented by a three-sided trim mountable at the outer edges of the back Ply- Figure 20 is a perspective view from above and one side of the three-sided trim in Figure 19;

Figure 21 is top plan view of the trim of Figure 20, and

Figure 22 is a perspective view from above and one side of the draft excluder of Figures 16 to 18 installed in a fireplace. Detailed Description of the Invention

Figures 1 to 14 describe a first embodiment of a chimney draft excluder 1 in accordance with the invention. As shown in the drawings, the chimney draft excluder 1 is made up of a draft excluding plate 2 insertable in a chimney flue to prevent chimney drafts, a support arm 3 contiguous with and depending from the draft excluding plate 2 to assist in holding the draft excluding plate in position in the chimney flue and a grate or basket box 4 (hereinafter referred to as a grate box 4) depending from and attached to the support arm 3 for insertion in a fire grate. The draft excluding plate 2 is provided with an optional centrally located vent 5 to permit limited airflow through the draft excluding plate 2.

The draft excluder 1 is formed and assembled from a blank made up of a first or bottom blank 6 and a second or top blank 7 secured to the bottom blank 6 as described more fully below.

As shown particularly in Figures 2 and 3, the bottom blank 6 is shaped and cut to define a draft excluding plate portion 2a, a support arm portion 3a and a bottom blank grate box portion 8. The bottom blank grate box portion 8 is provided with a plurality of fold lines 9 to facilitate folding of the bottom blank grate box portion 8 in a wide range of conformations as described more fully below in relation to Figures 6 to 8 while a transverse support arm fold line 35 is defined between the plate portion 2a and the support arm portion 3a. The draft excluding plate portion 2a is shaped to conform to a conventional Irish or British chimney flue and has an outwardly bowed deformable top skirt 16, an outwardly bowed deformable first side skirt 17 and an outwardly bowed deformable second side skirt 18. The outwardly bowed top skirt 16 enables the draft excluder 1 to be used with bowed and non-bowed fireplaces. The first and second outwardly bowed side skirts 17,18 extend substantially upwards and outwards in a divergent manner from the support arm portion 3a. The peripheral and deformable top skirt 16, first side skirt 17 and second side skirt 18 facilitate the adaptation of the draft excluding plate portion 2a to the shape and size of a chimney.

As will be appreciated by those skilled in the art, the chimney draft excluder 1 of the invention can be shaped as required to be compatible with differently shaped chimney flues including US, European and even once-off chimney flues without departing from the scope of the invention.

The deformable outwardly bowed top and side skirts 16,17,18 are formed by multiple inwardly extending cuts in the top plate portion 2a to create elongate members in the form of flexible top skirt, first side skirt and second side skirt tines 9,20,21

respectively. The tines 19,20,21 are dimensioned to be sufficiently flexible and resilient to secure the draft excluder 1 in-situ in use.

The top skirt 16 is provided with a large flue fold line 22 transverse to the longitudinal axis of the top skirt tines 19 to facilitate folding, flexing and bending of the top edge tines 19 about the large flue fold line 22. Similarly, the first and second side skirts 17,18 are provided large flue fold lines 23,24 respectively which extend parallel to their outer edges and transverse to the longitudinal axes of the first and second side edge tines 20,21. The large flue fold lines 22,23,24 facilitate bending and flexing of the top skirt tines 19 and the first and second side skirt tines 20,21 so that the draft excluding plate 2 can enjoy a tight friction fit with a large size chimney flue in use.

The top face 15 of the draft excluding face portion 2a is provided with a first adhesion area 33 for receiving adhesive to secure the top blank 7 to the bottom blank 6. Similarly, the support arm portion 3a is provided with a second adhesion area 34 for receiving adhesive to secure the top blank 7 to the bottom blank 6.

The draft excluding plate portion 2a is further provided with a transverse fold line 54 disposed beneath the vent 5 to facilitate folding of the draft excluding plate 2 to render the draft excluder 1 of the invention compact for packaging prior to use.

As shown in Figures 4 and 5, in an analogous manner to the bottom blank 6, the top blank 7 is shaped and cut to define a draft excluding plate portion 2b, a support arm portion 3b and a top blank grate box portion 10. The top blank 7 is dimensioned to be smaller than the bottom blank 6 so that the outer edges of the bottom blank 6 define the outer perimeter of the draft excluder 1 of the invention. The draft excluding plate portion 2b is joined to the support arm portion 3b at a transverse support arm fold line 36 corresponding to the support arm fold line 35 on the bottom sheet 6.

The top blank grate box portion 10 is made up of substantially square top panel 12 adapted to form the top face of the grate box 4 following assembly. The top panel 12 is defined by an upper fold line 46 and a lower fold line 47 and is provided with a warning legend 13 to remind a user that the draft excluder 1 is in operation. A foldable reinforcing tab 14 extends laterally from the top panel 12. During

manufacture, the foldable reinforcing tab 14 is back folded along its side edge and secured to the reverse face 25 of the top panel 12 (e.g. with adhesive) to enhance the structural integrity of the grate box 4. As with the grate box portion 8 of the bottom blank 6, the grate box portion of the top blank 7 is provided with a plurality of transverse fold lines 11 to facilitate multiple grate box 4 conformations following assembly. The grate box portion 10 is further provided with a terminal glue receiving tab 32 to form the grate box 4 during manufacture.

The top blank 7 is shaped to be complimentary to the bottom blank 6. More particularly, the draft excluding plate portion 2b is provided with a peripheral straight top skirt 26 and peripheral straight first and second side skirts 27,28 respectively. As with the first and second side skirts 7,18 of the bottom blank 6, the first and second side skirts 27,28 of the top blank 7 extend laterally upwards and outwards in a diagonal fashion towards the straight top skirt 26.

The draft excluding plate portion 2b is also provided with a transverse packaging fold line 55, complimentary to the packaging fold line 54 on draft excluding plate portion 2a of the bottom blank 6, to facilitate compact folding of the draft excluder 1 for packaging purposes.

The top skirt 26 and the side skirts 27,28 are made up of top tines 29 and side tines 30,31 respectively similar to the tines 19,20,21 of the bottom blank 6. The top tines 29 and side tines 30,31 are also formed by multiple inwardly extending cuts in the draft excluding plate portion 2b. The top blank 7 is dimensioned so that the top tines 29 of the top blank 7 overlap the top edge tines 19 of the bottom blank 6 and the side tines 30,31 overlap the side edge tines 20,21 respectively of the bottom blank 6 in such a way that the outer edge 37 of the top blank 7 at the top tines 29 and the side tines 30,31 defines top and side medium flue fold lines 48,49,50 on the draft excluder 1 i.e. when the draft excluder 1 is inserted in a flue of medium size the top edge tines 19 and the side edge tines 20,21 of the bottom blank 6 flex and bend at the outer edge of the top blank 7 - i.e. the top tines 29 and the side tines 30,31 of the top blank 7 reinforce the top tines 19 and side tines 20,21 of the bottom blank to create the medium flue fold lines 48,49,50 at their extremities.

In a similar fashion, small flue top and side fold lines 51 ,52,53 respectively are defined by the base of the top tines 29 and the side tines 30,31 of the top blank 7 as shall be explained more fully below.

In use, as shown in Figures 9 to 14, an end user 41 simply unfolds the draft excluder 1 following removal from its packaging and inserts the draft excluding plate 2 into the flue or throat 45 of a chimney 42. The draft excluder 1 is located in the flue 45 of the chimney 42 at the chimney fireback or smoke chamber 44. The user then simply pushes the draft excluding plate 2 upwards until the draft excluding plate 2 engages tightly with the flue 45 at the large flue fold lines 22,23,24 or medium flue fold lines 48,49,50 or small flue fold lines 51 ,52,53 on the respective tines 19,20,21 or

29,30,31 of the skirts 16,17,18 and 26,27,28 as appropriate. The tines 19,20,21 ,29,30,31 grip the chimney flue 45 to securely hold the draft excluder 1 in situ whilst also allowing the draft excluding plate 2 to adapt and conform to the shape and dimensions of the chimney flue and simultaneously adapting to any irregularities in the surface of the chimney flue 45.

It will be appreciated by those skilled in the art that the draft excluder 1 of the invention can be dimensioned and/or shaped as required to suit a range of flue sizes and shapes e.g. British, Irish, US chimney flues and throats etc. Moreover, although the use of adhesives has been described in the manufacture of the draft excluder 1 , it will be appreciated by those skilled in the art that other bonding methods could be used such as riveting, punching and the like.

Following insertion of the draft excluding plate 2, the user 41 can then form the grate box 4 into the appropriate size and shape for the fire grate or basket 43 of the fireplace 40 by folding the bottom blank grate box portion 8 and the top blank grate box portion 10 about the fold lines 9, 1 as previously described. Figures 6 to 8 illustrate three of the many grate box 4 conformations possible.

The warning legend 13 on the top panel 12 of the grate box 12 serves to warn or remind users that the draft excluder 1 is in use. However, should a user

inadvertently place fuel on the grate box 4 with a view to lighting a fire, the fold lines 9,11 of the grate box co-operate to define a failsafe chimney opening mechanism facilitating collapse of the grate box 4 under the weight of the fuel. Collapse of the grate box 4 results in detachment of the draft excluding plate 2 from the flue to open the chimney and permit egress of smoke should the fuel be lit. Unlike the draft excluders of the prior art, the draft excluder 1 of the invention can be installed by a user quickly, easily and without expert help. As the draft excluder 1 can conform to the size and often irregular shape of chimney flues, the draft excluder is highly efficacious at eliminating drafts in a safe and easy manner.

Figure 15 shows a top blank 7 of alternative embodiment of a draft excluder 1 of the invention for use with gas or other fixed fuel supplies in which the grate box 4 is replaced by an elongate strip 38 adapted to wrap around gas fire coals in-situ. Like numerals indicated like parts. The elongate strip 38 serves as a warning that the draft excluder 1 is installed and can also be provided with a carbon monoxide indicator 39 to warn of excessive carbon monoxide levels.

Figures 6 to 18 show a third embodiment of a draft excluder 1 of the invention broadly similar to the embodiment described in Figures 1 to 14 but in which the bottom blank 6 is in the form of a back ply 56, the grate box 4 is omitted and the support arm 3 is elongated to hold the draft excluding plate 2 in situ in use. Like numerals indicate like parts.

More particularly, the back ply 56 corresponds in size and structure to the draft excluding plate portion 2a of the bottom blank 6 and is provided with a deformable top skirt 16, a deformable first side skirt 17 and a deformable second side skirt 8. However, in the present embodiment, back ply 56 is further provided with a

deformable bottom skirt 57 to further enhance the fit of the draft excluder 1 in a chimney. The skirts 16,17,18,57 are formed from tines as previously described. The back ply 56 can be dimensioned according to the dimensions of a chimney so that the draft excluder 1 can be adapted for use with various chimney sizes accord the dimensions of the back ply 56 employed.

The top blank 7 is broadly similar in shape to the top blank 7 of Figures 1 to 14. However, in the present embodiment, the top blank 7 is made up of a draft excluding plate portion 2b and an elongate support arm portion 3b. The draft excluding plate portion 2b is joined to the support arm portion 3b at a transverse support arm fold line 36 while the support arm portion 3b is further provided with a lower fold line 59 to facilitate elbow-like folding of the support arm portion 3b so that the support arm portion 3b can support the draft excluding plate 2b in a chimney. The lower fold line 59 also serves to define a collapsing failsafe mechanism in the present embodiment whereby fuel accidentally placed by a user on the support arm 3 in use will cause the support arm 3 to fold at the lower fold line 59 to collapse the draft excluder 1 and retract the draft excluding plate 2 from a chimney flue in use.

The support arm portion 3b is provided with a pair of projecting terminal tabs 60 at its free end. The terminal tabs 60 are insertable in a series of tab receiving slots 58 of the draft excluding plate portion 2b to secure the support arm portion 3b to the draft excluding plate portion 2b. The slots 58 can be selected according to the size and orientation of the chimney in which the draft excluder 1 is to be inserted i.e. the angle and orientation of the support arm portion 3b and the draft excluding plate 2b can be adjusted according to the tab receiving slots 58 employed.

The draft excluding plate portion 2b is also provided with a pair of tabs 61 at its free end. The pair of tabs 61 is insertable in complimentary back ply slots 62 defined in the back ply 56 to secure the back ply 56 to the draft excluding plate portion 2b. The back ply 56 is further secured in position on the draft excluding portion 2b by a flap 63, located adjacent the support arm fold line 36, defined by a cut in the draft excluding plate portion 2b.

Figures 19 to 21 show a fourth embodiment of the draft excluder 1 of the invention broadly similar to the embodiment described in Figures 16 to 18 but in which the back ply 56 can be augmented by a three-sided deformable trim 64 to vary the size of the back ply 56 according to chimney size. Like numerals indicate like parts.

In the present embodiment, the three-sided trim 64 is equivalent to the top edge 16, first side edge 17 and second side edge 18 of the draft excluding plate portion 2b of the top blank 7 and is dimensioned and adapted to fit over the top edge 16, first side edge 17 and second side edge 18 proper of the draft excluding plate portion 2b to increase the size of draft excluding plate portion 2b. The top edge 16, the first side edge 17 and the second side edge 18 of the trim 64 are provided with deformable tines 19,20,21 as previously described. A plurality of interconnectable three-sided trims 64 of increasing sizes can be employed as required to grow the dimensions of the draft excluding plate portion 2b of the draft excluder 1 as required.

Figure 22 shows a perspective view from above and one side of the draft excluder 1 of Figures 16 to 18 or indeed Figures 19 to 21 installed in a fireplace 40. As shown in the drawing, the draft excluder 1 is assembled as previously described so that the support arm portion 3b is folded about the support arm fold line 36 and the lower fold line 59 to define the support arm 3 which holds the draft excluding plate 2 in situ in the fireplace 40 at the chimney flue 45 to prevent chimney drafts. More particularly, the support arm 3 extends between the draft excluding plate 2 and the grate 43 to securely hold the draft excluder 1 in position and to effect a draft excluding seal in the chimney 42.

In yet a further embodiment of the invention, a spacer device may be located behind the top panel 12 of the grate box 4 to ensure that the top panel 12 is disposed constantly outwards to render the warning legend 13 highly visible at all times.

If desired, the draft excluder 1 can also be provided in a range of colours to match decor and fireplace colours and can also be provided with decorative finishes or images. Alternatively, a user can apply personalised finishes such as photographs or seasonal images to the draft excluder.

The draft excluder 1 can also be provided with additional sealing components attached to the draft excluder 1 to effect complete sealing of a chimney flue if desired. Examples of such sealing components include foam sealants and the like.

The draft excluder 1 of the invention is typically manufactured from a flammable material such as cardboard which is both flammable and recyclable. A preferred cardboard from which the top and bottom blanks 6,7 can be formed, for use with standard fireplaces having chimney sizes ranging from about 14 inches to 18 inches which embraces the three standard Irish or British flue sizes of 14 inches (small), 16 inches (medium) and 18 inches (large) is E Flute (Trade Mark) cardboard which has a thickness of 1.6mm and which has desirable rigidity and flexibility characteristics. Typically, the tines in such a draft excluder dimensioned for the aforementioned chimney sizes and formed from E Flute cardboard will have a width of about 4mm to produce the desired flexibility and rigidity. However, the thickness and type of cardboard used and the dimensions of the draft excluder, its skirts and tines may be varied as required according to the dimensions and shape of the chimneys to which the draft excluder is to be applied without departing from the scope of the invention.

In a preferred embodiment of the invention, the cardboard has a matt finish to prevent light from being reflected from the draft excluder 1 in use. Moreover, the reverse face of the bottom blank 6 can be laminated or coated with a water resistant material to protect the draft excluder from moisture, rain and debris. The bottom and top blanks 6,7 can be cut from cardboard and formed as previously described. The top and bottom blanks 6,7 are then secured to each other, typically using adhesives. The draft excluder 1 can be folded along the bottom and top blank plate fold lines 35,36 and the packaging fold lines 54,55 to form a compact easily assembled structure for packaging purposes.

The optional vent 5 of the draft excluder can be a fixed open vent. However, if desired, the vent 5 can be provided with a manually adjustable flap or tab to open and close the vent 5 as required. Alternatively, the vent 5 can be a scored pop-out vent 5 that can be pushed out from the draft excluder 1 if desired.

As will be appreciated by those familiar with the packaging or manufacturing arts, the draft excluder 1 can be formed using known techniques e.g. the tines, folds and the like can be formed using cutting, perforating, scoring methods and the like. The invention is not limited to the embodiments herein described which may be varied in construction and detail without departing from the scope of the invention.