GB2437731A

GB2437731A - Cavity closer adjustable to fit different cavity sizes by foldable projection

Info

Publication number: GB2437731A
Application number: GB0608754A
Authority: GB
Inventors: Anthony Lee Hughes
Original assignee: Epwin Group PLC
Current assignee: Epwin Group PLC
Priority date: 2006-05-03
Filing date: 2006-05-03
Publication date: 2007-11-07
Anticipated expiration: 2026-05-03
Also published as: GB0608754D0; GB2437731B

Abstract

A cavity closer (220) has a body (221) which is received between inner and outer leaves of a cavity wall and protrusions (222, 224) which abut the inner and outer leaves and, together with a face (221b) of the body (221) form a fascia (225) of the cavity closer (220). In addition, the cavity closer (220) has a flange (223) projecting from the body (221). The flange (223) can be folded so that it has a variable width to fit in different sizes of cavity. This means that the same basic extrusion die for a cavity closer can be used for manufacturing cavity closers to suit different designs of building by being adaptable to suit different cavity widths. To achieve such folding, the flange may have appropriately located lines of weakness (223c) therein. In addition, or alternatively, the cavity closer (220) has local rotatable retaining clips located in a channel in the cavity closer. Those clips may then be used to retain a window frame on the cavity closer. This means that the retaining clips can be located at points in the channel which are not damaged or filled with debris.

Description

1 2437731

CAVITY CLOSER

This invention relates to a cavity closer, a method of manufacturing a cavity closer, a cavity closer assembly, methods of assembling and disassembling a cavity closer assembly, a closed cavity wall and a window assembly.

It is well known in the new build industry to use cavity walls. These are walls which have inner and outer leaves of bricks or blocks separated by a gap. A cavity wall has greater stiffness than a single- leaf wall and furthermore the gap between the leaves helps to thermally insulate the interior of the wall from the exterior.

Where a window is to be integrated into a cavity wall, it is usual for the builder to be supplied with a cavity closer which acts as a template or subframe for bricking the correct opening size in the wall to accept the window frame. The cavity closer also helps the builder achieve the correct cavity width (cavity space), i.e. the correct width of gap between the outer leaf of the wall and the inner leaf. To achieve this the cavity closer must be of the same nominal width as the cavity width, though it is usual for the cavity closer to be of a smaller width than the theoretical cavity width to take account of tolerances on the bricks or blocks and the accuracy with which the wall can be constructed. Cavity widths are variable and can be 50, 65, 75mm or larger dependent on the building design. It is therefore common practice to either use a series of extrusion dies to make cavity closers of different widths to fit different cavity sizes, or to use a separate component to extend the basic cavity closer extrusion to suit different cavity widths. The former is expensive due to the need for multiple extrusion tooling, and the latter is time consuming because the extension piece must be fitted. It is also known to cut parts of cavity closers to fit in different sized cavities, though this is a time consuming process.

It is often the case that the same cavity closer has features designed into it that allow a window frame to be easily fixed in place in the opening in the wall, without the need for screws or other time consuming fixing methods. Often a retaining bead is fitted against the window frame which clips to a purpose designed channel in the cavity closer. The window frame is then held between this retaining bead and a frame stop which is integrated into the cavity closer. An example of such a known arrangement is shown in Fig. 3 of the accompanying drawings. Fig. 3 shows a window assembly 110. A cavity closer 120 has a surface 125a with a retaining bead channel 126 formed in it. A frame stop 128 protrudes from the same surface 125a a distance away from the channel 126. A window frame 140 is located against the frame stop 128 (in this case with a seal 150 between the two) and then a continuous retaining bead 130 is clipped into the channel 126. A part 133a of the retaining bead then butts against the window frame 140 to retain it between the retaining bead 130 and the protruding frame stop 128.

Because the cavity closer will be installed during the building process, the channel in the cavity closer, such as channel 126 in Fig. 3, may become filled in places with rubble, mortar etc. and will have to be cleaned out before the retaining bead can be fitted. The channel may also be damaged during the building process such that a continuous retaining bead cannot be fitted without repair to the channel. Both of these processes are time consuming and costly.

At its most general, the present invention proposes having a cavity closer with a portion which can be folded so that it has a variable width to fit in different sizes of cavity. This means that the same basic extrusion die for a cavity closer can be used for manufacturing cavity closers to suit different designs of building by being adaptable to suit different cavity widths. Thus, building costs may be reduced, as use of a series of dies to make cavity closers of different designs is avoided.

The present invention also proposes having a cavity closer with local rotatable retaining clips located in a channel in the cavity closer. Those clips may then be used to retain a window frame on the cavity closer. This means that the retaining clips can be located at points in the channel which are not damaged or filled with debris, and so such debris need not be first cleared.

The present invention has several aspects. Thus, according to the first aspect, the present invention provides a method of manufacturing a cavity closer, said method including the steps of: extruding material to form a body and a projection, said body being adapted to locate in a gap between an inner and an outer leaf of a cavity wall, and said projection extending from a side of the core portion; creating at least one line of weakness along the projection in the direction of extrusion; and folding said projection along one of said at least one lines of weakness.

The process of folding the projection is easy and quick to do. This process has the advantage that the same extrusion die can be used to form cavity closers suitable for different cavity widths. The at least one line of weakness is/are formed at a position or at positions where the subsequent folding of the projection results in a cavity closer with a suitable width.

Furthermore, this also means that a range of cavity closers can be manufactured without having to insert extensions or cut parts of the cavity closer, which is time consuming. This reduces the cost of manufacture of cavity closers as advantage can be taken of economies of scale in manufacture by using one die to manufacture a range of sizes of cavity closer to suit different building designs.

The or each line of weakness may be created by forming a groove or grooves in a surface of said projection. These grooves are very easily formed during manufacture of the cavity closer, preferably as a part of the profile of the extrusion resulting from the shape of the extrusion die, but alternatively they may be formed by cutting the projection once the material has been extruded. The formation of a groove in a surface means that when the projection is subsequently folded, there is not an excess of material which may interfere with a uniform fold.

Alternatively the or each line of weakness may be created by heating a portion or portions of the projection. Thus, once the material of the projection is heated it subsequently becomes flexible and easily bendable. After bending, the projection would be allowed to cool and remain in its folded state.

Preferably a plurality of said lines of weakness are formed. This gives an option as to where to fold the projection, so the same extrusion die can be used for manufacturing cavity closers that can be folded at different places. Preferably said projection is folded by 9Q0 Preferably a protrusion is also formed during the extrusion of the material, said protrusion extending from said side of the body and being adapted to abut a leaf of the cavity wall. Preferably the projection is folded such that its distal end extends towards said protrusion.

Thus when the projection is folded, the distal end of the projection becomes located between the protrusion and the first edge of the body that, in use, is inserted into a cavity. Therefore, the projection is less likely to get damaged than if it folded away from the protrusion, as in the latter situation the projection may be the first part of the cavity closer to be inserted into a cavity and so would be the first part of the cavity closer to hit any obstruction in the cavity. As the projection may be narrow, such hitting of obstructions could damage the projection.

According to a second aspect of the present invention there is provided a cavity closer comprising: a body and a projection, said body being adapted to locate in a gap between an inner and an outer leaf of a cavity wall, and said projection extending from a side of the core portion, wherein said projection has a fold therein.

Preferably said cavity closer further comprises a protrusion extending from said side of the body and adapted to abut a leaf of the cavity wall.

According to a third aspect of the present invention there is provided a closed cavity wall comprising an inner leaf, an outer leaf and a cavity closer according to the second aspect of the invention, wherein said body is located in a gap between the inner and outer leaf of the cavity wall.

According to a fourth aspect of the present invention there is provided a cavity closer assembly having: a cavity closer comprising a body adapted to be located in a gap between an inner and an outer leaf of a cavity wall and a protrusion extending from a side of the body and adapted to abut a leaf of the cavity wall, the protrusion and a face of the body defining a fascia, the fascia having a channel extending along the cavity closer, the channel having an open mouth with a transverse width less than the internal transverse width of the channel; and at least one retaining clip, said at least one clip having an abutment part for abutting an object to be mounted on the cavity closer, a retaining part in the channel and having a width in a first direction less than the transverse width of the mouth of the channel and a width in a second direction greater than the transverse width of the mouth of the channel, and a shaft joining the abutment part and the retaining part, the shaft having a width less than the transverse width of the mouth of the channel, wherein the clip is rotatable between a retained position in which the second direction is aligned with the transverse width of the mouth of the channel and an insertion position in which the first direction is aligned with the transverse width of the mouth of the channel and the retaining part is arranged to pass through the mouth of the channel.

This provides the advantage that if debris is located in parts of the channel within the cavity closer, or if the channel is damaged at points along its length, the retaining clips can still be located in parts of the channel where there is no debris or damage. Furthermore, less material is required to produce the retaining clips than the known retaining bead, and the number of retaining clips used can be chosen depending on the likely loads that the assembly will need to resist during its lifetime.

The feature that the retaining clip is rotatable to an insertion position means that the retaining clip can be easily removed from the channel, if required, and the cavity closer assembly can be easily disassembled without damage to the component parts. If required, these parts can then be reused to reassemble the cavity closer assembly.

The channel may be formed such that it is flush with the surface of the fascia, or such that a mouth of the channel protrudes from the surface of the fascia.

Preferably the first direction is perpendicular to the second direction. This provides the advantage that if the retaining clip is accidentally slightly rotated from the retained position, the slight rotation will be insufficient for the retaining clip to reach the insertion position. Thus even if the retaining clip is accidentally nudged, the clip remains in the channel and the assembly remains secure.

Preferably the retaining part comprises two lugs extending in opposite directions from the clip.

Preferably the mouth is formed between two lips extending from inner walls of the channel.

Preferably the abutment part of the at least one retaining clip is cam-shaped. Thus when the clip is rotated from the insertion position to the retained position it is adapted to exert a force against a window frame against which it may be abutted. When the cavity closer includes a frame stop, as in the known design in Fig. 3, the window frame is thus urged towards the frame stop by the cam to be held firmly between the clip and the frame stop. The window frame will thus be prevented from rattling within the assembly and a good seal is provided between the window frame and the frame stop.

Preferably there are a plurality of said retaining clips located in said channel. This means that a window frame can be held by the cavity closer at a series of places, thus holding the window frame more securely.

Typically the retaining clips are located in the channel with a maximum separation (pitch) of 600mm in order to let the assembly resist the loads that will act on it during its life.

Preferably a socket is formed in a surface of the abutment part of said at least one retaining clip, said socket being suitable to accept a tool, such as a screwdriver, an alien key or a hex key. It may be suitable to accept a different type of tool. Thus a tool may be used to aid in the rotation of the retaining clip, as such tools provide leverage.

According to a fifth aspect of the present invention there is provided a kit of parts for a cavity closer assembly, said kit of parts comprising: a cavity closer comprising a body adapted to be located in a gap between an inner and an outer leaf of a cavity wall and a protrusion extending from a side of the body and adapted to abut a leaf of the cavity wall, the protrusion and a face of the body defining a fascia, the fascia having a channel extending along the cavity closer, the channel having an open mouth with a transverse width less than the internal transverse width of the channel; and at least one retaining clip, said at least one clip having an abutment part for abutting an object to be mounted on the cavity closer, a retaining part locatable in the channel and having a width in a first direction less than the transverse width of the mouth of the channel and a width in a second direction greater than the transverse width of the mouth of the channel, and a shaft joining the abutment part and the retaining part, the shaft having a width less than the transverse width of the mouth of the channel, wherein the clip is rotatable between a retained position in which the second direction is aligned with the transverse width of the mouth of the channel and an insertion position in which the first direction is aligned with the transverse width of the mouth of the channel and the retaining part is passable through the mouth of the channel.

According to a sixth aspect of the present invention there is provided a method of assembling a cavity closer assembly according to the fourth aspect of the invention, wherein said method comprises the steps of: inserting the retaining part of the at least one retaining clip into the channel by passing it through the mouth in the insertion position; and rotating said at least one retaining clip relative to the channel to the retained position, such that the at least one retaining clip is prevented from being withdrawn from the channel.

The method of assembly of the cavity closer is quick and easy to perform. As mentioned above, a surface of the abutment part of said at least one retaining clip may have a socket formed therein so that a tool such as an alien key, hex key or screwdriver may be used to rotate the retaining clip to the retained position.

Preferably the retaining clip is rotated through 9Q0 between the insertion position and the retained position so if the retaining clip is accidentally slightly rotated from the retained position, the assembly remains secure.

According to a seventh aspect of the present invention there is provided a method of disassembling a cavity closer assembly according to the fourth aspect of the invention, wherein said method comprises the steps of: rotating said at least one retaining clip relative to the channel from the retained position to the insertion position; and withdrawing the at least one retaining clip from the channel through the mouth.

This method of disassembly can therefore be performed quickly and easily without damage to the parts of the cavity closer, so the parts can be reused in re-assembly of the cavity closer, should the need arise.

Again, a tool such as an alien key, hex key or screwdriver may be used as described above.

Preferably the retaining clip is rotated through 9Q0 between the retained position and the insertion position.

As mentioned above, this means that when the retaining clip is in the retained position, a slight nudge to the clip will not result in it reaching the insertion position, and thus the assembly remains secure.

According to an eighth aspect of the present invention there is provided a window assembly comprising a cavity closer assembly according to the fourth aspect of the invention and a window frame, wherein the at least one retaining clip is in the retained position and abuts the window frame, whereby said window frame is held between the abutment part of the at least one retaining clip and a portion of the cavity closer.

Preferably a flat surface of the abutment part of the retaining clip abuts the window frame. Thus any forces acting on the window frame in the direction of the retaining clip are spread over a wider contact area at the interface between the retaining clip and the window frame, so the retaining clip exerts a lower pressure on the window frame lessening any potential indentation caused by the clip in a surface of the window frame.

Furthermore, the flat surface means that the retaining clip will not be rotated from the retained position by an accidental nudge.

Preferably a seal is located between said portion of the cavity closer and the window frame. This better insulates the interior of the window frame from the exterior, by making the window assembly watertight and airtight. The seal may be made of thermoplastic rubbers, foam materials or any other flexible material so that it can block the path of air or liquid between the exterior and interior of the window assembly.

Preferably the abutment part of the at least one retaining clip is cam-shaped. Thus, when the at least one retaining clip is rotated from the insertion position to the retained position during assembly of the window assembly, the abutment part exerts a force against the window frame towards said portion of the cavity closer, thereby urging the window frame towards said portion.

Once the retaining clip is in the retained position, the window frame is held firmly against said portion, making the overall assembly secure.

Embodiments of the present invention will now be described in detail, by way of example, with reference to the accompanying drawings, in which: Fig. 1 shows a stage in the formation of a cavity closer according to a first embodiment of the present invention; Fig. 2 is a general schematic view of a cavity closer according to the first embodiment of the present invention; Fig. 3 is a general schematic view of a known window assembly; Fig. 4a is a plan view of a cavity closer assembly according to a second embodiment of the present invention; Fig. 4b is a general schematic view of a cavity closer assembly according to the second embodiment of the present invention; Fig. 5 is a general schematic view of a window assembly incorporating the second embodiment of the present invention; Referring first to Figs. 1 and 2, the manufacture of a cavity closer will now be described. Fig. 1 shows a cavity closer 220 in a midway state in its formation. It has a body 221, a protrusion 222 extending from side 221c of the body 221, and a projection 223 also extending from side 221c of the body 221 in the same direction as the protrusion 222. The projection 223 is a flange. In this embodiment, a second protrusion 224 extends from another side of the body 221. The combination of protrusion 222, face 221b of the body 221 (and in this case protrusion 224) is a fascia 225.

Between the inner and outer leaves of a cavity wall (not shown) is a gap of a certain width. The body 221 is adapted to locate in this gap, and protrusion 222 is adapted to abut one of said leaves of the cavity wall at surface 222a. In this embodiment, surface 224a of the second protrusion 224 is adapted to abut the outer leaf of the cavity wall. So, when surfaces 222a and 224a abut the ends of the inner and outer leaves of the cavity wall respectively, body 221 is located in the gap between the leaves. It will however be appreciated that the reverse can be true in other circumstances, i.e. surface 222a can abut the outer leaf while surface 224a abuts the inner leaf.

The method of manufacturing the cavity closer 220 includes a step of extruding material to produce the body 221, protrusion 222 and flange 223. This extrusion is performed such that the extrusion direction is out of the page, as Fig. 1 is drawn. Three grooves 223a are formed in surface 223c of the flange 223 to present lines of weakness in the direction of the extrusion. These grooves are formed in the flange 223 by the shape of the extrusion die when the material is extruded.

Fig. 1 thus illustrates the process of manufacture of a cavity closer 220 according to the present invention up to this stage.

Fig. 2 illustrates the subsequent step of folding the flange 223 along one of the lines of weakness 223a.

This folding is carried out by passing the cavity closer 220 through a series of rollers which encourage the flange 223 into the position shown in Fig. 2, i.e. folded by 900. It will be noted that the flange 223 is folded in Fig. 2 such that its distal end 223b extends towards protrusion 222. Thus when the cavity closer 220 is subsequently inserted into a cavity between inner and outer leaves of the cavity wall, face 221a of the body 221 would be the first part of the cavity closer 220 to hit any obstruction in the cavity. Were flange 223 to be folded such that the distal end 223b extends away from the protrusion 222, i.e. downwards on the page as Fig. 2 is drawn, the flange 223 would be the first part of the cavity closer 220 to be inserted into the cavity. As the flange 223 is relatively thin, when compared to the face 221a of the body 221, it is more prone to damage by hitting such obstructions than the face 221a.

Before the folding step is carried out, the part of the cavity closer 220 designed to locate in a cavity has a width Wi which, when the body is located in the gap between inner and outer leaves of the cavity wall, is in the direction of the gap spacing between the leaves. The gap spacing is the distance between the inner and outer leaves of the wall. The width Wi includes the distance by which the flange 223 extends from the body 221.

As will be appreciated, when the flange 223 is folded, width Wi is reduced to W2, as shown in Fig. 2.

Thus the cavity closer 220 in Fig. 2 can be inserted into a cavity gap with a width greater than W2 and narrower than Wi. Of course the flange 223 could have been folded at any of the shown grooves 223a, so that the most suitable width of cavity closer 220 can be achieved for the cavity in which it is to be inserted. Furthermore, the flange 223 need not have been folded if it was to be used in a cavity width larger than Wi.

It will be noted in Figs. 1 and 2 that the body 221 extends perpendicularly from the fascia 225. Therefore, when the body 221 is fully located in a cavity, i.e. with surfaces 222a and 224a abutting the end faces of the leaves of the cavity wall, the fascia 225 lies perpendicularly to the direction in which the cavity wall runs. Thus, when a cavity closer such as that shown in Fig. 2 is fitted at an opening in a cavity wall, fitting a window frame in the opening is easier than if the fascia 225 lies at an angle to the cavity wall.

Fig. 3 was discussed above in relation to known window assemblies 110.

Fig. 4b shows a general schematic view of a cavity closer assembly according to a second embodiment of the present invention. The cavity closer 220 of that assembly has a fascia 225, comprising face 221b of the body 221, protrusion 222 that extends from side 221c of the body 221 and, in this embodiment, a second protrusion 224 that extends from another side of the body 221. The protrusions 222, 224 are adapted to abut leaves of a cavity wall at surfaces 222a, 224a.

The fascia 225 has a channel 226 formed along a surface 225a thereof. The channel 226 extends along the full length of the cavity closer 220. The channel 226 in this embodiment is formed in the part of the fascia 225 which is the face 221b of the body 221, though it will be appreciated that the channel 226 may optionally have been formed in the part of the fascia 225 which is protrusion 222. The channel 226 has two lips 227 extending from opposite inner walls 226a, 226b, and between those lips 227 is the open mouth 226c of the channel 226.

Fig. 4b shows that the cavity closer 220 receives a retaining clip 230 in channel 226. The clip 230 has a shaft 231 passing through the mouth 226c of the channel 226 and a retaining part formed by two lugs 232 extending radially from the shaft 231. These lugs 232 are located further (i.e. deeper) in the channel 226 than the lips 227. The clip 230 is shown in Fig. 4b in a retained position where the lugs 232 are aligned with the transverse width of the mouth 226c of the channel 226.

In this position the clip 230 is prevented from being removed (vertically as the figure is drawn) from the channel 226. The clip 230 is rotatable relative to the channel 226 and such rotation is used to assemble and disassemble the cavity closer assembly as will be described in more detail later.

Fig. 4b also shows that an abutment part 233 of retaining clip 230 includes a socket 234 formed in a surface thereof. This socket is suitable to accept an allen key, which can be used to aid rotation of the clip 230 between the retained position, as shown, and the insertion position.

Fig. 4a is a plan view of the arrangement in Fig. 4b. Retaining clip 230 is still shown in the retained position. In this figure a second retaining clip 230b is shown, which is itself identical to retaining clip 230 but it is shown in the insertion position relative to the channel 226. In this embodiment, there are a plurality of retaining clips 230 located in the channel 226, although not all of them are shown in Figs. 4a and 4b.

It can be seen in Fig. 4a that the lugs 232 are only located on opposite sides of the shaft 231 of the retaining clips 230, 230b, and do not extend around the full perimeter of the shaft 231. Therefore the width of the retaining part in a first direction, excluding the lugs 232, is less than the transverse width of the mouth 226c of the channel 226, and the width in a second direction, i.e. including the lugs 232, is greater than the transverse width of the mouth 226c. The lips 227 of the channel 226 do not overlap any part of the lugs 232 in retaining clip 230b, and so the clip 230b can be lifted from the channel 226, i.e. the first direction of the clip 230b is aligned with the transverse width of the mouth 226c. However, the lips 227 of the channel 226 do overlap the lugs 232 in retaining clip 230, and so the clip 230 cannot be lifted out of the channel 226. In other words, the second direction of clip 230 is aligned with the transverse width of the mouth 226c.

The allen key socket 234 is clearly visible in Fig. 4a. As mentioned above, this allows an allen key to be used to rotate the retaining clips 230, 230b by 900 between the retained position, in which retaining clip 230 is shown, and the insertion position, in which retaining clip 230b is shown. It is also clear in Fig. 4a that the shaft 231 of the retaining clips 230, 230b has a circular cross section. It will be appreciated that due to this circular cross section, at all times when the retaining clips 230, 230b are located in the channel 226, the shaft 231 is in contact with the lip 227. This means there is a close fit between the retaining clip230 and the open mouth 226c of the channel 226, and so the clip 230 cannot rattle in the channel 226. Thus when a window frame is held by the retaining clip 230, it is also prevented from rattling due to play between the retaining clip 230 and the lip 227.

Fig. 4a also shows that abutment part 233 of the retaining clip 230, 230b has a cam profile with a flat surface 233a at one part of the cam profile. When the retaining clip 230b is rotated from the insertion position to the position in which retaining clip 230 is shown, part of the abutment part 233, i.e. the part including flat surface 233a, overlaps the edge of channel 226. With reference also to Fig. 5, it can therefore be seen that as the retaining clip 230b is rotated from the insertion position to the retained position, this part of the abutment part 233 butts against a window frame 240 in a window assembly 210 and urges it towards a frame stop 228. This ensures that the window frame 240 is securely held in the window assembly 210 when the retaining clip 230 is in the retained position.

The flat surface 233a means that when retaining clip 230 is in a retained position and abuts a window frame 240 in the window assembly 210, any forces acting on the window frame 240 in the direction of the retaining clip 230 are spread over a wider contact area with the retaining clip 230, 50 the retaining clip 230 exerts a lower pressure on the window frame 240, thereby lessening any potential indentation caused by the clip 230 in a surface of the window frame 240. Furthermore, the flat surface 233a means that the retaining clip 230 cannot be easily rotated from the retained position when it is abutting a window frame 240. Thus any accidental nudges to the retaining clip 230 will not cause it to rotate to the insertion position, which may otherwise allow the window frame 240 to rattle in the window assembly 210.

The method of assembling the cavity closer assembly of the second embodiment of the invention will now be briefly described with reference to Figs. 4a and 4b.

To assemble the cavity closer assembly, at least one retaining clip 230 is inserted into the channel 226 of the cavity closer 220 by passing it through the mouth 226c in the insertion position, i.e. with its lugs 232 aligned with the direction of extension of the open mouth 226c of the channel 226. Once in the channel 226, the retaining clip 230 is rotated by 90 relative to the channel 226 such that the lugs 232 on the shaft 231 of the retaining clip 230 become unaligned with the mouth 226c and aligned with the transverse width of the mouth 226c. This is the retained position, and here the retaining clip 230 is prevented from being withdrawn from the channel 226 because the lips 227 of the mouth 226c overlap the lugs 232.

The process of disassembly is the same process, but in reverse. The retaining clip 230 is rotated from the retained position, as retaining clip 230b is shown in Fig. 4a, by 90 relative to the channel 226 to the insertion position, such that the first direction of the clip 230 is aligned with the transverse width of the mouth 226c. The retaining clip 230 is then withdrawn from the channel 226 through the mouth 226c, and the cavity closer assembly is disassembled.

Fig. 5 shows a window assembly, shown generally as 210, incorporating a cavity closer assembly according to the second embodiment of the present invention. Elements in this figure identical to those in Fig. 4b have the same reference numerals as in Fig. 4b, and will not all be described again.

The cavity closer 220 of the cavity closer assembly has a fascia 225 comprising face 221b of the body 221, protrusion 222 and second protrusion 224. The protrusions 222, 224 are adapted at surfaces 222a, 224a to butt against the ends of an inner leaf and an outer leaf of a cavity wall (not shown) . By inner leaf and outer leaf it is meant an inner course of bricks in a cavity wall and by outer leaf it is meant an outer course of bricks in the cavity wall. By definition, cavity walls have a gap between such inner and outer leaves and it is into this gap that the body 221 of the cavity closer 220 is adapted to be located.

A frame stop 228 is formed on surface 225a of the fascia 225, distant from the channel 226. This frame stop 228 is a portion of the cavity closer 220. As is shown in Fig. 5, this frame stop 228 has a decorative or sculpted finish on surface 228a, to improve the appearance of the window assembly 210.

A window frame 240 is located between the retaining clip 230, which is shown in the retained position, and the frame stop 228. The flat surface 233a of abutment part 233 of the retaining clip 230 abuts the window frame 240. The dimensions of the window frame 240 and cavity closer 220 are such that the window frame 240 fits snugly between the retaining clip 230 and the frame stop 228.

In order to ensure that the interface between the window frame 240 and the frame stop 228 is airtight and watertight, a seal 250 is located between the two. This seal 250 is made of a thermoplastic rubber.

It will thus be appreciated that movement of the window frame 240 left to right relative to the page is prevented by the retaining clip 230 and the frame stop 228.

Although only one retaining clip 230 is shown in Fig. 5, there are in fact a plurality of clips 230 located at 600mm intervals along the channel 226 (600mm pitch) It will be noted that retaining clip 230 includes a socket 234 in its abutment part 233. This socket 234 is suitable to accept an allen key (not shown) , which can be used to rotate the retaining clip 230 between the insertion position and the retained position (as shown) With reference to Figs. 4a and 5, the method of assembling the window assembly 210 will be briefly described. First of all window frame 240 is introduced to the cavity closer 220 in a rightwards direction, as Fig. is drawn, and is located against frame stop 228.

The retaining clip 230 is then inserted into the channel 226 in surface 225a of the fascia 225, such that it is in the insertion position (see retaining clip 230b in Fig. 4a) . The retaining clip 230 is then rotated 90 (either by hand or by using an alien key inserted in socket 234) to the retained position, as retaining clip 230 is shown in Fig. 4a. At this point the retaining clip 230 is held in the channel 226 due to lips 227 overlapping lugs 232, and the flat surface 233a of the abutment part 233 of the retaining clip 230 abuts the window frame 240, such that the window frame 240 is firmly held between retaining clip 230 and frame stop 228.

The method of disassembling the window assembly 210 is the same process but in reverse. Starting with the arrangement shown in Fig. 5, retaining clip 230 is rotated 90 from the retained position (as clip 230 is shown in Fig. 4a) to the insertion position (as clip 230b is shown in Fig. 4a) . This rotation may either be made by hand or by using an allen key inserted in socket 234 in the abutment part 233 of the retaining clip 230. When the retaining clip 230 is in the insertion position, no part of the lips 227 overlaps lugs 232, and so the retaining clip 230 may be withdrawn from the channel 226.

Once all retaining clips 230 holding the window frame 240 against the cavity closer 220 have been removed from the channel 226, the window frame 240 may be easily removed from the cavity closer 220 in a leftwards direction, as Fig. 5 is drawn.

It will thus be appreciated that the cavity closer of the present invention has the advantage over known cavity closers that a single design of extrusion die can be used in the manufacture of cavity closers for different building designs which have different widths of cavity in their cavity walls. This reduces the cost of manufacture of cavity closers, as advantage can be taken of economies of scale in manufacture by using one size of extrusion die, which creates cavity closers which are adaptable to suit different building designs.

Furthermore, the cavity closer of the present invention allows window frames to be secured when part of a channel for receiving window frame retaining clips is damaged or blocked. This reduces the cost of assembly of cavity closer assemblies and window assemblies, and thus the cost of construction of buildings because less labourers' time needs to be spent fitting window frames, as the channel in the cavity closer does not need to be repaired or cleared.

Claims

CLAIMS: 1. A method of manufacturing a cavity closer, said method

including the steps of: extruding material to form a body and a projection, said body being adapted to locate in a gap between an inner and an outer leaf of a cavity wall, and said projection extending from a side of the core portion; creating at least one line of weakness along the projection in the direction of extrusion; and folding said projection along one of said at least one lines of weakness.

2. A method of manufacturing a cavity closer according to claim 1, wherein said at least one line of weakness is created by forming a groove or grooves in a surface of said projection.

3. A method of manufacturing a cavity closer according to claim 2, wherein said groove or grooves are formed as the material is extruded.

4. A method of manufacturing a cavity closer according to claim 1, wherein said at least one line of weakness is created by heating a portion or portions of the projection.

5. A method of manufacturing a cavity closer according to any of claims 1 to 4, wherein a plurality of said lines of weakness are formed in the projection.

6. A method of manufacturing a cavity closer according to any of claims 1 to 5, wherein said projection is folded by 9Q0 7. A method of manufacturing a cavity closer according to any one of claims 1 to 6, wherein a protrusion is also formed during the extrusion of the material, said protrusion extending from said side of the body and being adapted to abut a leaf of the cavity wall.

8. A method of manufacturing a cavity closer according to claim 7, wherein said projection is folded such that its distal end extends towards said protrusion.

9. A cavity closer comprising: a body and a projection, said body being adapted to locate in a gap between an inner and an outer leaf of a cavity wall, and said projection extending from a side of the body, wherein said projection has a fold therein.

10. A cavity closer according to claim 9, wherein said cavity closer further comprises a protrusion extending from said side of the body and adapted to abut a leaf of the cavity wall.

11. A closed cavity wall comprising an inner leaf, an outer leaf and a cavity closer according to claim 9 or claim 10, wherein said body is located in a gap between the inner and outer leaf of the cavity wall.

12. A cavity closer assembly having: a cavity closer comprising a body adapted to be located in a gap between an inner and an outer leaf of a cavity wall and a protrusion extending from a side of the body and adapted to abut a leaf of the cavity wall, the protrusion and a face of the body defining a fascia, the fascia having a channel extending along the cavity closer, the channel having an open mouth with a transverse width less than the internal transverse width of the channel; and at least one retaining clip, said at least one clip having an abutment part for abutting an object to be mounted on the cavity closer, a retaining part in the channel and having a width in a first direction less than the transverse width of the mouth of the channel and a width in a second direction greater than the transverse width of the mouth of the channel, and a shaft joining the abutment part and the retaining part, the shaft having a width less than the transverse width of the mouth of the channel, wherein the clip is rotatable between a retained position in which the second direction is aligned with the transverse width of the mouth of the channel and an insertion position in which the first direction is aligned with the transverse width of the mouth of the channel and the retaining part is arranged to pass through the mouth of the channel.

13. A cavity closer assembly according to claim 12, wherein the first direction is perpendicular to the second direction.

14. A cavity closer assembly according to claim 12 or claim 13, wherein the retaining part comprises two lugs extending in opposite directions from the clip.

15. A cavity closer assembly according to any of claims 12 to 14, wherein the mouth is formed between two lips extending from inner walls of the channel.

16. A cavity closer assembly according to any of claims 12 to 15, wherein the abutment part of the at least one retaining clip is cam-shaped.

17. A cavity closer assembly according to any of claims 12 to 16, wherein there are a plurality of said retaining clips located in said channel.

18. A cavity closer assembly according to any of claims 12 to 17, wherein a socket is formed in a surface of the abutment part of said at least one retaining clip, said socket being suitable to accept a tool, such as a screwdriver, an allen key or a hex key.

19. A kit of parts for a cavity closer assembly, said kit of parts comprising: a cavity closer comprising a body adapted to be located in a gap between an inner and an outer leaf of a cavity wall and a protrusion extending from a side of the body and adapted to abut a leaf of the cavity wall, the protrusion and a face of the body defining a fascia, the fascia having a channel extending along the cavity closer, the channel having an open mouth with a transverse width less than the internal transverse width of the channel; and at least one retaining clip, said at least one clip having an abutment part for abutting an object to be mounted on the cavity closer, a retaining part locatable in the channel and having a width in a first direction less than the transverse width of the mouth of the channel and a width in a second direction greater than the transverse width of the mouth of the channel, and a shaft joining the abutment part and the retaining part, the shaft having a width less than the transverse width of the mouth of the channel, wherein the clip is such that the retaining part is passable through the mouth of the channel to an insertion position in which the first direction is aligned with the transverse width of the mouth of the channel and is then rotatable to a retained position in which the second direction is aligned with the transverse width of the mouth of the channel.

20. A method of assembling a cavity closer assembly, the cavity closer assembly being according to any one of claims 12 to 18, wherein said method comprises the steps of: inserting the retaining part of the at least one retaining clip into the channel by passing it through the mouth in the insertion position; and rotating said at least one retaining clip relative to the channel to the retained position, such that the at least one retaining clip is prevented from being withdrawn from the channel.

21. A method of assembling a cavity closer assembly according to claim 20, wherein the retaining clip is rotated through 90 between the insertion position and the retained position.

22. A method of disassembling a cavity closer assembly, the cavity closer assembly being according to any one of claims 12 to 18, wherein said method comprises the steps of: rotating said at least one retaining clip relative to the channel from the retained position to the insertion position; and withdrawing the at least one retaining clip from the channel through the mouth.

23. A method of disassembling a cavity closer assembly according to claim 22, wherein the retaining clip is rotated through 900 between the retained position and the insertion position.

24. A window assembly comprising a cavity closer assembly according to any one of claims 12 to 18 and a window frame, wherein the at least one retaining clip is in the retained position and abuts the window frame, whereby said window frame is held between the abutment part of the at least one retaining clip and a portion of the cavity closer.

25. A window assembly according to claim 24, wherein a flat surface of the abutment part of the retaining clip abuts the window frame.

26. A window assembly according to claim 24 or claim 25, wherein a seal is located between said portion of the cavity closer and the window frame.

27. A method of manufacturing a cavity closer substantially as described herein with reference to and as illustrated in Figs. 1 and
2.

28. A cavity closer substantially as described herein with reference to and as illustrated in Fig. 2.

29. A cavity closer assembly substantially as described herein with reference to and as illustrated in Figs. 4a and 4b.

30. A method of assembling a cavity closer assembly substantially as described herein with reference to and as illustrated in Figs. 4a and 4b.

31. A window assembly substantially as described herein with reference to and as illustrated in Fig. 5.