GB2295185A - Fixing frames into apertures in cavity walls - Google Patents

Abstract

A cavity closer 104 comprises a facing portions 108 and at least one distinct side wall portion 120, the facing portion and the side wall portions having engagement means 114, 116, 122 for respective interengagement, wherein the facing portion has more than two such engagement means 114, 116, thereby to allow engagement of the/or each side wall in a selected position of a plurality of available positions to vary the external width of the cavity closer. Other embodiments include window frames with attachment points for cavity closers, and cavity closers adapted to receive engagement means of window frames. <IMAGE>

Description

FRAME ELEMENTS The present invention relates to window acceptors and related frame elements.

It is known to hold window frames in their respective openings by providing an outer frame about the opening which engages with the window frame by means of a resilient catch engaging behind a lip. Thus, the window frame is inserted by offering it up to the outer frame and pushing into place. Possibly the earliest examples of this are in Dutch Application No. 8321027 and US Patent No. 3694985. Since then attempts have been made to refine the basic idea, including GB 2277768 in which a window frame is clipped to a cavity closer by means of an intermediate member.

The present invention seeks to provide a window system which employs this concept yet is simple to manufacture and instal.

The present invention provides (in its first aspect) a cavity closer comprising a facing portion and at least one distinct side wall portion, the facing portion and the side wall portions having engagement means for respective interengagement, wherein the facing portion has more than two such engagement means, thereby to allow engagement of the side walls in a selected position of a plurality of available positions.

This enables the cavity closer to be supplied as standard item and yet be "tailored" to the particular cavity wall being built.

Preferably, there are more than two engagement means on the facing portion, arranged in an array to provide a greater choice of available positions. More preferably, there are more than three. Even more preferably, the facing portion provides at least two engagement means for the side wall portion, thereby to provide two point engagement or better.

This provides a significantly sturdier arrangement.

In a variant form, the present invention provides a window or door frame system comprising an outer frame for receiving a window or door frame, the outer frame being fixable to a wall and including an engagement means for interengagement with the window or door frame, and a pair of dovetailed-recesses, one either side of the engagement means, each capable of interengagement with a backstop, thereby to enable the backstop to be fitted in a selected one of two mutually reversed positions, thereby to enable the window or door frame to be fitted from the inside or from the outside.

To the knowledge of the inventor, no window or door frame system which included a backstop for the sub-frame has been provided which is capable of allowing inward or outward fitting of the frame. Thus, previously, in systems which have the preferable sealing and robustness characteristics offered by a backstop, it was necessary to decide from which direction the window would be fitted during building of the wall.

This constraint is eliminated by the present invention.

The present invention also, independently, relates to a window or door frame system comprising an outer frame fixable to a wall and including an engagement means capable of interengagement with the window or door frame, and at least one dovetailed recess adjacent the engagement means, and a spacer strip engageable with the dove-tailed recess and having a further engagement means, thereby effectively replicating the engagement means further inset from the wall. This allows very slim outer frames, or cavity closers such as those defined above which act as an outer frame, to be empioyed in situations where the user wishes to apply a render to the wall surface. This is achieved without having to fit the window frame at an early stage, which would obviate the intended advantages of window acceptor systems.

Preferably, there are two dove-tailed recesses3 one either side of an engagement means. More preferably, the spacer strip when engaged with the recess or recesses covers the engagement means. This provides a neat and robust arrangement.

In its second independent aspect, the present invention provides a window frame system comprising an outer frame fixable to a cavity wall and having two engagement portions; a window frame incorporating a means for engagement with one engagement portion of the outer frame; a cavity closer adapted to at least project into the cavity of the cavity wall and incorporating a means for engagement with the other engagement portion of the outer frame, thereby to hold it within the cavity.

The engagement portions of the outer frame can be simple recesses adapted to receive engaging catches of the window frame and cavity closer.

Ideally, the engagement portion engaged by the window frame will be a longitudinal recess for receiving a resilient catch, thereby to retain the window frame3 enabling the window to be offered up to its frame and pressed into place. The engagement portion for the cavity closer can be a dovetailed or part-dovetailed recess into which fits a resiliently expanding catch of the cavity closer.

This aspect of the present invention also reiates to a cavity closer having an integral means for engaging a separate frame. Preferably, the means for engaging includes a resiliently deformable catch. Thus, it can be engaged in a dovetailed or part-dovetailed recess.

It also relates to a frame member fixable to a cavity wall and having two engagement portions, one adapted to engage a window frame and one adapted to engage a cavity closer. For ease of fitting, it is preferred that the frame is symmetrical.

The present invention therefore provides, in its third independent aspect, a window or door frame kit, comprising: a cavity closer having at least one dovetailed recess on an accessible face thereof; a frame element adapted to surround a glazing pane; an intermediate member having means for engagement with the frame element and an engagement lip extending in use away from the recess, and a clip adapted to engage with the engagement lip of the intermediate member and having a second lip adapted, when so engaged, to project into the recess; the second lip being engageable in the dovetailed recess.

Preferably, the clip is U-shaped with one arm longer than the other, thereby to provide the second lip. Thus, the U-shaped clip can fit over the engagement lip with the second lip projecting into the recess.

In this case, there will preferably be a form of positive engagement between the clip and the engagement lip. This may be by internal serration of the clip, or external serration of the engagement lip, or both.

The engagement of the second lip in the recess may be by means of a resilient member on the second lip which engages behind the dovetailing of the recess.

In its fourth independent aspect, the present invention provides a cavity closer comprising a generally rectangular section for placing in a cavity between walls, the cavity closer having on at least two faces thereof a recess suitable for receiving an engagement means attached to a frame, each such recess being offset from the central axis of its respective face and having sufficient symmetry so that the closer is capable of being placed in a cavity in at least two orientations in which a recess is externally accessible; the accessible recess being in a transversely different location in the two orientations.

Thus, this fourth aspect of the present invention enables a window frame to be fitted at a chosen transverse location within the opening.

However, this is achieved whilst simultaneously avoiding the problem of one side of the window frame latching in a different recess to the other.

Preferably, the cavity closer is of a non-heat conductive material (e.g. UPVC). It is also preferred if the cavity closer is hollow to receive a thermally insulating material.

It is also preferred if the cavity closer has a recess or other means for engaging a wall tie in order to fix it in position.

Embodiments of the present invention will now be described, by way of example, with reference to the accompanying Figures, in which: Figure 1 is a cross-section through a cavity closer according to the present invention, fitted to a 65mm cavity; Figure 2 is a cross-section through a cavity closer according to the present invention, fitted to a 75mm cavity; Figure 3 is a cross-section through a cavity closer according to the present invention, fitted to a 85mm cavity; Figure 4 is a cross-section through a cavity closer according to the present invention, fitted to a lOOmm cavity; Figures 5 and 6 show the cavity closer of Figures 1 to 4 in use, with a window frame fitted from the rear and from the front respectively;; Figures 7 and 8 show the cavity closer of Figures 5 and 6, also in use, in a render application, the window being fitted as in Figures 5 and 6 respectively; Figure 9 is a cross-section through a fitted frame according to the present invention; Figure 10 is a cross-section through a fitted frame according to the present invention; Figure 11 is a cross-section through the jamb of a window frame according to the present invention; Figure lia is an enlarged part of Figure 11, for clarity; Figure 12 is a cross-section through the sill edge of a window frame according to the present invention; Figure 12a is an enlarged part of Figure 12, for clarity; Figure 13 is a cross-section through the sill edge of a second embodiment of the present invention; Figure 14 is a cross-section through an alternative outer frame;; Figure 15 is a cross-section through a further alternative outer frame; Figure 16 is a sectional view of a window jamb held in place by an arrangement according to the first aspect of the present invention; Figure 17 is a sectional view of a window cill similarly held in place; Figure 18 is an enlarged sectional view of a part of the arrangement shown in Figures 16 and 17; Figure 19 is a cross-section of a cavity closer according to the second aspect of the present invention; and Figure 20 is a sectional view of a window jamb engaged with a cavity closer according to the second aspect of the present invention.

Figures 1 to 4 show a cavity closer according to the present invention. As shown, it is inserted between two curtain walls 100, 102, and Figures 1 to 4 show how the cavity closer of the present invention can accommodate cavities of varying dimensions. In Figure 1, the gap is 65mm, in Figure 2 the gap is 75mm, in Figure 3 the gap is 85mm and in Figure 4 the gap is 100mm. The closer 104 comprises a body portion 106 which lies within the cavity between the walls 100 and 102. At the front edge of the closer 104 is a front face 108 which has an engagement recess 110 into which window frames may be engaged, as is apparent from later embodiments of the invention such as those shown in Figure 16. Behind the engagement portion 110, ie spaced along the front face 108, is a ribbed surface 112 which serves to secure a covering plaster layer (not shown).

This layer would be applied once the installation of the window was complete.

On the rear of the front face 108, behind the ribbed surface 112, are a series of laterally spaced clips 114. These consist of an L-shaped projecfion which thus define a small recess behind the clip 114. At the extreme end of the projection is a small inwardly directed ridge 116 which thus provides a part-dovetail nature to the recess. The body 106 of the closer 104 also has a dovetailed recess 118 formed on the side facing generally towards the clips 114.

A side wall 120 is provided, which has a generally elongate body portion and at one end thereof a rearwardly directed lip 122 which is iorrned with a slight ridge and hence adapted to be engaged in the recess behind a clip 114. At the upper end of the body portion is a corresponding lower lip 124 which is adapted to engage within the recess 118 of the body portion 106. Formed into the surface of the elongate body of the side wall 120 is a dovetailed recess 126 which mirrors the recess 118 of the cavity closer body 106.

The dimensions of the closer 104 and side wall 120 are such that when the side wall 120 is clipped into place behind the clip 114 closest the body 106 and into the recess 118, the external width of the body 106 and side wall 120 is 65mm, thus ensuring that the assembly fits neatly into a 65mm cavity.

As shown in Figure 2, there is also provided within this embodiment of the invention an alternate side wall 130. This differs from the first side wall 120 in that the lip 124' is considerably laterally extended. Thus, when the second side wall 130 is clipped into place behind the second clip 114 and into the recess 118, the external dimension of the assembled closer is 75mm, thus allowing the assembly to fit within a 75mm cavity.

Both the first and second side walls 120,130 have a second dovetailed recess 126 and 126' which mirrors the recess 118 on the cavity closer body 106. Thus, it is possible to put both in place simultaneously, as shown in Figure 3. In this figure, the second side wall 130 is clipped to the second clip 114 and to the recess wall 118. Then, the first side wail 120 is clipped to the third clip 114 and the recess 126'. The positions of the closers could be reversed. Thus, the external dimension of the closer is now 85mm, and fits into an 85mm cavity neatly.

In Figure 4, the first side wall 120 of Figure 3 has been replaced by a further second side wall 130. This clips into the recess 126' of the original second side wall 13û and into the fourth clip 114. As a result, the external dimension of the assembled closer is 100mm and this neatly closes a 100mm cavity.

Thus, this embodiment of the present invention provides a simple yet versatile cavity closer. Only three parts are employed, all are easily physically distinguishable by their external shape and are thus unlikely to be confused, and all can be assembled quickly, easily and in a simple fashion to provide the appropriate shape.

Figures 5 and 6 show the cavity closer of Figures 1 to 4 in place.

The body 106 of the closer is held in place with wall ties 107.

A window frame 132, of generally conventional profile, is fitted in place by a spring tang 134 extending from the outer edge of the frame 132.

As shown in Figure 5, the frame is fitted from the inside of the building, i.e. from the direction of wall 102, and therefore the spring tang 134 is directed generally toward the wall 102 to prevent movement.

Either side of the recess 110 are dove-tailed recesses 136a and 136b.

They are dove-tailed in that the opening of the recess is narrower than their interior. Recess 136a is, when the closer 106 is installed, closer to outer wall 100 and recess 136b is correspondingly closer to inner wall 102.

In the arrangement of Figure 5, a backstop 138 is fitted to the recess 136a.

The backstop 138 comprises a ramp portion 140, from the rear of which extends of lug for engagement in the recess 136a. The ramp section 140 leads to a transversely projecting abutment face which is lined with a rubber sealant strip 142. As shown, the sealant strip engages within the dove-tailed recess formed in the backstop 138.

Figure 6 shows a window formed using the same construction or elements as Figure 5 and in which like reference numerals are employed to denote like parts, but in which the window frame 132 has been fitted from the front, i.e. from the direction of outer wall 100. To achieve this, the spring tang 134 is fitted into the window frame 132 in a reverse orientation, so that it is, once installed, directed towards the outer wall 100, and the backstop 138 is fitted to the recess 136b of the closer 106 which is closer to the inner wall 102.

Thus, by this embodiment, the cavity closer 106 can be fitted during construction of the walls 100 and 102, and the opening left clear until completion of the job. During this period, no obstruction is present in the opening, and no frames or other supports protrude significantly from the wall edges. When it is desired to fit the window, for example at the end of construction, the backstop 138 can be fitted either in recess 136a or in recess 136b according to the direction of desired fitting of the window 132, the tang 134 can be clipped into place in the window frame 132, and the window frame 132 smoothly slotted into position.

Figures 7 and 8 show how any difficulties caused by the very low profile of this cavity closer/outer frame 106 can be overcome in applications where a render layer 144 is to be provided. Such a render layer 144 might otherwise obscure the recess 110 and hinder insertion of the window frame 132.

According to the embodiment of Figures 7 and 8, there is provided a spacer frame 146 which comprises a pair of outwardly directed lugs 148a and 148b. These project into the recesses 136a and 136b to secure the spacer frame 146 in place in front of the recess 110. On the inner face of the spacer frame 146 is an engagement recess 110' which is located on the spacer strip so as to mimic the location of the engagement recess 110 of the cavity closer 106. Thus, the frame 132 and tang 134 can engage into this replacement recess 110'.

At a lateral edge of the spacer frame 146 is backstop 138' which serves to mimic the backstop 138 of Figures 5 and 6.

The spacer frame 146 is formed so that it can be inserted into the recesses 136a and 136b in one of two mutually reversed positions, thereby to enable inward or outward fitting of the frame 132, as in Figures 5 and 6.

The depth of the spacer frame 146 corresponds generally to the normal depth of a render layer 144. Normally, the spacer frame 146 would be fitted to the cavity closer 106 after the walls 100 and 102 have been completed but before the render layer 144 had been applied.

Figures 9 and 10 each show further embodiments of the invention.

Common to both of these embodiments is a cavity closer in which the front face 42 is sufficiently laterally extended to overlap both curtain walls 14.

On the rear face thereof 3 there are pair of dovetailed recesses 60, 62 in which are engaged wall ties 16, holding the cavity closer to each curtain wall 14. On the front face 42 of the cavity closer, there is an engagement portion 64 for engaging behind the inwardly directed lips 22, 24 of the outer frame 12. In Figure 9 this comprises a plateau region defined at its edges by two recesses each of which has an overhang adjacent the plateau behind which engages the flanges 22, 24. On Figure 10, engagement portion 64 comprises a pair of outwardly extending lipped projections 70, 72 whose respective lips engage behind the flanges 22, 24. Thus, instead of being held directly to the wall by a tie 16, the outer frame 12 is attached to an extended cavity closer which is in turn held by a tie 16 to the wall 14.

On the rear face of the cavity closer, between the dovetailed recesses 60, 62 of the wall ties 16 there are a series of engagement ridges 74a to 749 (Figure 9) or 74h (Figure 10). These ridges are, in this example, in the form of a T-profile; what is important is that they provide a snap-fit engagement. Thus, they are wider at their tip than at a point intermediate the tip and root. Onto two of these engagement ridges 74, are clipped a pair of side walls 38, 40 for the cavity closer. These consist of a substantially flat wall portion with, at one end, a claw portion 76 for engaging a ridge 74. Because there are more than two ridges 74, a user has a choice of positions for the side walls 38, 40 and can position them at a desired spacing corresponding to the exact width of the cavity wall.In Figures 9 and 10, a 50mm width has been chosen but it can clearly been seen that up to twice this width could be accommodated. Also, this design enables adjustment of the relative lateral positioning of the side wall portions 38, 40 and the outer frame 12.

Note that the walls 38, 40 shown in Figure 10 have T-profile portions 78 at their lower edges. This provides a more positive grip with the inside of the cavity and retention for any insulation blocks which may be placed between the walls 38, 40.

Referring to Figure 11, this shows a window frame 10 'n & in place by interengagement with outer frame 12 which is fixed to a wall 14 via the tie 16. The window frame 10 latches on to the outer frame 12 by a resiliently deformable flap 18 on the underside of the window frame 10 which can be deformed to lie closer to the window frame 10 and which, when the window frame is in position, is biased outward toward its natural position and into a longitudinal channel 20 along the centre line of the outer frame 12. The outer edge of the outer frame 12 is defined by a pair of inturned lips 22, 24 which engage behind a dovetailed engagement portion 26 of the wall tie 16. The body 28 of the wall tie 16 is built into the structure of the wall 14 in the conventional fashion.

Along its edge facing the cavity 30 of the wall 14 the outer frame 12 has a longitudinally running channel 32. That channel 32 is defined at one edge by a projecting lip 34 and thus the opening of the channel 32 is narrower than its interior.

The cavity closer 36 has a pair of side faces 38, 40 which abut the internal side faces of the cavity 30, and a facing portion 42 which covers the cavity opening and extends slightly on either side thereof against the ends of the wall 14. The outer surface of the facing portion 42 is slightly serrated to give greater adhesion to a covering layer of plaster 44.

An edging panel 46 extends from the facing portion 42 roughly transverse thereto. The edging panel 46 is positioned along the facing portion 42 so that in use it lies against the inner face of the outer frame 12.

The edging panel 46 is sufficiently long to hide the resilient leaf 18 and associated engagement portions.

Projecting from a side of the edging panel 46 toward the outer frame 12 is a tongue 48, which consists of a projecting stem and at the tip thereof a reverse-directed resilient deformable lip, at a rest angle of approximately 45". In use, the tongue 48 is positioned to project into the recess 32 with the resilient lip engaging behind the projecting lip 34, i.e. extending into the wider internal space of the recess 32. Thus, the cavity closer 36 is engaged with the outer frame 12.

The cavity closer includes an insulation element 50 which is held between the side walls 38, 40.

Figure 12 shows a cross-section through the same window at its sill portion. Like reference numerals have been used to denote equivalent parts, and it will be noted that the major difference is that a sill 32 has been interposed between the outer frame 12 and the window frame 10. To maintain the structure, the resilient lip 18 now depends from the underside of the sill 52.

Figure 12 also shows a tongue 54 on the edging panel 46 additional to the connecting lip 48. This tongue is tapered away from the edging panel 46 and projects into the region between the sill 52 and the outer frame 12 to act as a riser and support to the window. Alternatively, or in addition, a taper block could be formed into the sill, or the tongue 54 provided as a separate clip-on part (see Figure 9).

Note that no wall tie 16 is needed at the lower edge of the window, since the outer frame 12 is held satisfactorily at its vertical edges, shown in Figure 11. Of course, the conventional horizontal courses of bricks mean that a wall tie would be difficult to install at the lower edge.

Figure 13 shows a substantially similar section to Figure 12, employing an alternative form of engagement between the outer frame 12 and the cavity closer 36. Instead of providing a longitudinal channel (32) on the outer frame 12, a pair of shallow trenches 56 and 58 are formed in the top surface and underside respectively. These are formed on both edges of the outer frame 12, in this example. The cavity closer 36 has instead of the projecting lip 48, a claw member 60 comprising a pair of projections 62, 64 which engage either side of the outer frame 12. These projections 62, 64 have inwardly directed ridges which engage within the shallow trenches 56 or 58. Since the ridges and trenches are relatively low, the outer frame 12 can "snap in" to the cavity closer 36.

Note that in Figure 13 the cavity closer comprises a series of side walls 40a, 40b, 40c extending from the rear face of the facing portion 42.

It is intended that these can be cut off as desired to suit varying sizes of cavity. This arrangement is seen as applicable to cavity closers in general, and not simply to those used in the context of the present invention.

Figure 13 also shows a wall tie 16 to demonstrate how it might engage with the outer frame 12. Of course, the wall tie would not normally be seen on the lower, sill edge of the window frame.

The outer frame 12 of Figure 13 is, as can be seen, symmetrical due to trenches 56, 58 being formed on both edges. This lends significant advantages in the construction of a frame since it plainly does not matter in which orientation it is inserted. Known outer frames appear always to be asymmetrical for some reason, and this has the result that if a builder inadvertently fixes it in place in the incorrect orientation, the window cannot be fitted. Since this may only be discovered once the wall 14 has been completed and the outer frame 12 is firmly affixed to the wall via the wall ties 16, this is a serious problem.

Figure 14 shows a modification to the outer frame 12 of Figure 1 to achieve symmetry. This is done by providing it with two longitudinal recesses 32, one on each side. Clearly, in use one such recess would be redundant as would one pair of trenches 56, 58 in Figure 3, but the additional cost of extruding an aluminium outer frame 12 to this shape is believed to be very low compared to the benefit of the later error-proofing.

Again, this symmetricality of the outer frame is seen as applicable to "clipin" windows in general, and not simply to those shown in the context of the present invention.

Figure 15 shows an alternative outer frame 12 in which the tongue 54 is incorporated as clip-on profile 56 which engages in a channel 58 on the outer frame 12. Note that symmetry of the outer frame 12 has been maintained by the provision of a further, redundant, channel 58' on the other edge of the frame 12.

Figure 16 shows the jamb 210 of a window frame. This is attached to a conventional wall which comprises inner and outer curtains 212 and 214.

Between the curtains is a cavity 216. At the edge of the wall a cavity closer 218 is inserted into the cavity 216 to block off the cavity. The cavity closer 218 is provided at its surface with a number of dovetailed recesses 220, dividing walls 222 between adjacent recesses 220 providing a form of resilient engagement with the sides of the curtain walls 212 and 214. At each corner of the cavity closer 218 are projecting lugs 224.

These engage with suitable recesses in transverse plates 226 which lie alongside the curtains 212 and 214 to retain the cavity closer 218 in place.

If desired, the transverse plates 226 can be affixed to the curtain walls 212, 214, for example by gluing or screwing. The frame member 210 is attached to the cavity closer 218 by an intermediate member 228 and clip 230. The intermediate member 228 comprises a generally flat portion 232 which lies alongside the a transverse plate 226. The portion 232 is provided with engaging lugs 224 which latch behind corresponding lugs on the frame member 210. At one end of the flat portion 232 is an engagement lip 238 projecting transversely of the portion 232 and away from the recess 220.

The clip 230 is U-shaped and placed over the engagement lip 238. One arm of the U-shape is significantly longer than the other, so in use this arm projects past the rest of the engagement lip 238 to form a second projecting lip 240 which projects into the dovetailed recess 220. The tip of the second lip 240 has a reverse-directed latch 236 of resilient material, which is pressed toward the second lip 240 as the lip 240 is inserted, but which then springs back to engage behind the dovetailing of the recess 220 and prevent future removal.

Thus, the window is assembled by fixing the cavity closer 218 in place3 and attaching the intermediate member 228 to the edge of the frame member 210. The frame member is then put in position and can be adjusted to its exact state since there is no engagement with the closer 218. Once the frame member 210 is correctly placed, the clip 230 is pushed into position. As can be seen in Figure 16, an internal surface of the clip 230 and an external surface of the engagement member 238 are serrated to provide for positive retention.

Sealant 242 and a wedge gasket 244 are applied around the edge of the frame to provide a watertight seal. Decorative boards 246 are applied at the interior of the window frame to provide a neat appearance, and a quadrant cover 248 can be applied to hide the clip 230.

Figure 17 shows a similar arrangement at the bottom edge of a window. It differs only in that a cill member 250 is provided between the frame member 210 and the intermediate member 228. The lugs 234 of the intermediate member 228 then engage into the cill member 250 and the frame member 210 is supported on the cill 250. Otherwise, the arrangement shown is identical in all respects, and no further description will be given here. Identical reference numerals are employed to denote corresponding parts.

Figure 18 shows an enlarged view of the engagement lip 238, clip 230 and second projecting lip 240. It can be seen that the intermediate member 232 simply lies alongside the cavity closer 218, allowing easy adjustment of position. Once the user is happy with its position, the clip 230 is inserted over the engagement lip 238, engaging via serrations 252 and 254. The clip 230 is retained in place by the resilient catch 236 on the second projecting lip 240 engaging behind a dovetail of the recess 220.

Figure 19 shows a cavity closer according to a second aspect of the present invention. The cavity closer 150 is of a generally rectangular box section having a hollow internal space filled with an insulating material 152.

The two short faces 154 of the cavity closer 150 are intended to lie adjacent internal faces of acavity wall and are provided with dovetailed recesses 156 suitable for engaging a wall tie 158.

The longer edges 150 each have a single recess 162 which is slightly dovetailed. These recesses 162 are offset from the centre of the faces in which they are formed; in the example shown they occupy slightly less than one-half the area of the faces on which they are formed and begin at the edge of that face.

Figure 20 shows the cavity closer 150 of Figure 19 in use to retain a frame element 210. Identical reference numerals are used in Figures 19 and 20 to denote identical parts.

From Figure 20 it can be seen that each corner of the cavity closer 150 has a corner recess 164, which is dovetailed. These, when in use, accept lugs 166 of transverse plates 158 which then lie alongside the walls 212, 214 and in the cavity in which the cavity closer 150 lies. These transverse plates 168 may be affixed to the walls 212, 213, for example by gluing or screwing.

A location leaf 170 is attached to the underside of the frame 210 by lugs 172 engaging within a suitable recess. The leaf 170 has at one end a transverse projecting lug 174 and behind that a resilient latch 176.

To assemble a window frame3 the cavity closer 150 is built into the cavity wall as the wail is built, together with the transverse plates 168.

When the opening for the window is ready to be fitted with the window the frame 210 incorporating the location leaf 170 is offered up to the window opening and slid from right to left in Figure 20 until the transverse directing lug 174 abuts an edge of the recess 162. At that point, the resilient catch 176 will spring into the recess 112. Note that the resilient catch 176 will not assume its natural position whilst engaged3 providing a permanent bias engagement. This is indicated in Figure 20 by the alternative position of the catch 176.

The reader will note that if the cavity closer 150 is installed in a reverse position3 obtained by rotation from the position shown in Figure 20 by 1800 about a horizontal axis 174, then the position of the accessible recess 162 will be transversely shifted to that shown in dotted, 162a.

Then, the frame member and location leaf will assume the position shown in dotted in Figure 20, that is 210a, 152a, 170a and 176a. Thus, an alternative position for the frame 210 is selectable independently on the preference of the user. However, this alternative position is achieved without providing an additional engageable recess 162 on the external face of the cavity closer 150 and for this reason there is less uncertainty and likelihood of incorrect fitting.

It will be appreciated by those skilled in the art that the above described embodiments are set forth purely as examples of the present invention. Many changes are possible to these examples which remain within the scope of the present invention.

Claims (23)

1. A cavity closer comprising a facing portion and at least one distinct side wall portion, the facing portion and the side wall portions having engagement means for respective interengagement, wherein the facing portion has more than two such engagement means3 thereby to allow engagement of the/or each side wall in a selected position of a plurality of available positions; thereby to vary the external width of the cavity closer.

2. A cavity closer according to Claim 1, wherein there are more than two engagement means on the facing portion.

3. A cavity closer according to Claim 1 or Claim 2 wherein the engagement means are arranged in a linear array.

4. A cavity closer according to any preceding claims wherein there are more than three engagement means on the facing portion.

5. A cavity closer according to any preceding claim wherein the facing portion provides at least two engagement means for the side wall portion, thereby to provide at least two point engagement.

6. A cavity closer according to Claim 5 wherein one engagement means is provided on a body portion adapted to extend into the cavity from a rear face of the facing porion.

7. A cavity closer according to any preceding claim wherein the engagement means comprises a dovetailed recess.

8. A window or door frame system comprising an outer frame for receiving a window or door frame3 the outer frame being fixable to a wall and including an engagement means for interengagement with the window or door frame, and a pair of dove-tailed recesses3 one either side of the engagement means3 each capable of interengagement with a backstop, thereby to enable the backstop to be fitted in a selected one of two mutually reversed positions3 thereby to enable the window or door frame to be fitted from the inside or from the outside.

9. A window or door frame system comprising an outer frame fixable to a wall and including an engagement means capable of interengagement with a window or door frame, and at least one dove tailed recess adjacent the engagement means, and a spacer strip engageable with the dove-tailed recess and having a further engagement means3 thereby effectively to replicate the engagement means further inset from the wall.

10. A window or door frame system according to Claim 9, wherein there are two dove-tailed recesses, either side of the engagement means.

11. A window or door frame system according to Claim 9 or Claim 10 wherein the spacer strip when engaged with the dove-tailed recess or recesses covers the engagement means of the outer frame.

12. A window frame system comprising an outer frame fixable to a cavity wall and having two engagement portions; a window frame incorporating a means for engagement with one engagement portion of the outer frame; a cavity closer adapted to at least project into the cavity of the cavity wall and incorporating a means for engagement with the other engagement portion of the outer frame, thereby to hold it within the cavity.

13. A window frame system according to Claim 12 wherein the engagement portions of the outer frame are recesses adapted to receive engaging catches of the window frame and cavity closer.

14. A window frame system according to Claim 13 wherein the engagement portion engaged by the window frame is a longitudinal recess for receiving a resilient catch, thereby to retain the window frame, enabling the window to be offered up to its frame and pressed into place.

15. A window frame system according to any one of Claims 12 to 14 wherein the engagement portion for the cavity closer is a dovetailed or part-dovetailed recess into which fits a resiliently expanding catch of the cavity closer.

16. A cavity closer having an integral means for engaging a separate frame.

17. A cavity closer according to Claim 16 wherein the means for engaging includes a resiliently deformable catch.

18. A window or door frame kit, comprising: a cavity closer having at least one dovetailed recess on an accessible face thereof; a frame element adapted to surround a glazing pane; an intermediate member having means for engagement with the frame element and an engagement lip extending in use away from the recess, and a clip adapted to engage with the engagement lip of the intermediate member and having a second lip adapted, when so engaged, to project into the recess; the second lip being engageable in the dovetailed recess.

19. A frame kit according to Claim 18 wherein the clip is U-shaped with one arm longer than the other, thereby to provide the second lip.

20. A cavity closer comprising a generally rectangular section for placing in a cavity between walls, the cavity closer having on at least two faces thereof a recess suitable for receiving an engagement means attached to a frame3 each such recess being offset from the central axis of its respective face and having sufficient symmetry so that the closer is capable of being placed in a cavity in at least two orientations in which a recess is externally accessible; the accessible recess being in a transversely different location in the two orientations.

21. A cavity closer according to Claim 20 wherein the cavity closer is of a non-heat conductive material.

22. A cavity closer according to Claim 19 or Claim 20 which is hollow to receive a thermally insulating material.

23. A window or door frame system or element of such a system substantially as any one described herein with reference to the accompanying Figures.