GB2287498A - Extender for a window subframe - Google Patents

Abstract

A window subframe includes at least two upright cavity closers extruded of polymeric material, each with a longitudinal channel (60) at a side facing a leaf of the cavity wall, in which channel is engaged a cavity closer extender (50) which snap-fits into the said channel to extend the width of the closer in order to adapt the closer to the width of the cavity. (Figure 17). <IMAGE>

Description

Extender for a Window Subframe This invention relates generally to the construction of window openings and window subframes and to an assembly of components, and method of assembly and use of such components, which facilitates such construction, and in particular to an extender for use with a window subframe.

It is known, for example from British Patent 1 469 228. to provide a closure for the space between the leaves of a cavity wall, to constitute a damp-proof barrier as between the two leaves and (as a component in a window structure) between the brickwork and the window frame.

Such cavity closers, as described therein, are formed as lengths of extruded polymeric material having parallel walls to extend contiguous with the brickwork within the cavity, and opposed outwardly extending flange portions to lie one on each inner margin of the respective leaves.

It has been proposed that such cavity closers may be used in window construction to constitute a window subframe. Window subframes have been proposed in which the cavity closer is a plastics extrusion which includes an integrally formed laterally projecting flange which in use lies flat against the end face of at least one of the leaves of the cavity wall at the window opening.

Such a flange is sometimes referred to as a window trim.

According to a first aspect of the present invention, there is provided a subframe for a window comprising a plurality of elongate subframe members including at least two upright cavity closers each having a longitudinal channel at a side of the closer facing a leaf of the wall when the closer is located in the cavity between two leaves of a wall in which the window is to be provided, and a cavity closer extender having a complementary formation for engagement with the longitudinal channel of a cavity closer to adapt the width of the closer to the width of the cavity in which the closer is located.

According to a second aspect of the invention, there is provided a method of constructing a window opening comprising, in any appropriate order, the steps of: (A) constructing a self-supporting subframe which includes two upright cavity closers, a sill member also serving as a cavity closer, and a head strip which may also be a cavity closer, (B) locating the subframe over a run of cavity wall with its sill member substantially closing the cavity, (C) connecting at least one cavity closer extender to the subframe to adapt the width of the subframe to the width of the cavity wall, (D) building the window opening around the located, width-extended subframe.

According to a third aspect of the invention, there is provided an elongate cavity closer extender having an elongate formation on one side thereof for engagement with a complementary formation on a side portion of a cavity closer, the said cavity closer extender serving, in use, to extend the effective width of the cavity closer to which it is attached.

The cavity closer extender may engage the closer as a snap fit.

The cavity closer preferably comprises an elongate chamber filled or partially filled with insulation material. It may be extruded of polymeric material, as also may be the cavity closer extender.

The cavity closer extender may include an elongate flange along one side thereof, for locating against the end face of a leaf of the cavity wall during use to assist in control of the depth of the cavity closer and extender combination within the cavity.

The invention will be further described, by way of example, and with reference to the accompanying drawings, in which: Figure 1 shows in perspective a lower corner of a partially constructed window opening and subframe assembly comprising cavity closers; Figure 2 shows diagrammatically the general arrangement of a completed window opening and subframe assembly; Figure 3 shows in perspective part of the upper portion of such an assembly including a conventional lintel; Figure 4 is a cross section through an alternative embodiment of a cavity closer; Figure 5 shows a detail of an alternative outwardly directed open longitudinal channel of a cavity closer; Figure 6 shows a cross section through another alternative cavity closer, Figure 7 shows a cross section through a trim member for use with the cavity closer shown in Figure 6, Figure 8 shows a cross section through a head section for use in a subframe assembly to be used with a closed lintel, Figure 9 shows a cross section through an extender for use with a cavity closer, Figure 10 shows a cross section through a cavity closer of the type shown in Figure 13 (see below), in position in a cavity wall configured to comprise a typical English reveal in combination with a typical wooden window frame and a trim member similar to that shown in Figure 7, Figure 11 is a view similar to Figure 10 except differing in that the plaster guide provided on the trim member is moulded in a different position, Figure 12 is a view similar to Figures 10 and 11 except the wall comprises a typical Scottish reveal and the trim member does not comprise a plaster guide strip.

Figure 13 shows an alternative embodiment of a cavity closer, similar to that shown in Figure 6, but differing in that it does not include longitudinal support flanges, Figure 14 shows a cross section through an alternative embodiment of a cavity closer, Figure 15 shows a cross section through an internal trim member for use with the cavity closer shown in Figure 14, Figure 16 shows an internal trim similar to the one shown in Figure 15, but having an alternative lug profile, Figure 17 is a view of an alternative embodiment cavity closer, Figure 18 shows a cross section through a cavity closer of the type shown in Figure 14 in position in a cavity wall configured to comprise a typical English reveal in combination with a typical PVCU window frame and an internal trim of the type shown in Figure 15, Figure 19 is a view similar to Figure 18 except the cavity wall is configured as a typical Scottish reveal and the internal trim shown in Figures 15 and 18 is not used, and Figure 20 is a view similar to Figures 18 and 19, wherein the cavity wall is configured with a typical English reveal, but with a wider cavity than that shown in Figure 18, and differing in that a cavity extender such as the one shown in Figure 9 is provided and in that the window frame is a typical wooden frame.

Figure 1 shows a cavity wall with an outer leaf of brickwork 1, an inner leaf 2 and a cavity 3 between the leaves. Such walls are commonplace and built to a variety of standard cavity spacing and configurations.

An extruded polymeric cavity closer 4 according to a first embodiment of the invention is located over a top or side edge (or underside) of such a wall. It possesses coplanar inner and outer flanges 5 and 6 respectlvely, separated by a channel 7 facing outwards.

A similar somewhat deeper channel 8, in the body of the cavity closer, faces inwards. Two shallow inclined channels 9 and 10, defined by walls 11 with inturned lips 12, occupy the sides of the closer. In contrast to the known type of closer, discussed above, the closer shown in Figure 1 is spaced from the inner walls of the cavity, and is somewhat V-shaped in cross-section.

To use such a cavity closer in fabrication of a window opening and subframe, the wall 1, 2, 3 of the building is first built to the desired lower level. A desired length of the closer to form the lower end 13 (Figure 2) is cut from the original extrusion and mitred at 45 at each end.

A second such length is cut and mitred to form the top 14 of the frame, and two lengths are cut and mitred to form the sides 15, 16. As an alternative to mitreing, the end of one closer length could be cut square and a complementary notch could be cut in the end of the length to be fitted thereto.

The cavity closer system above described, together with its method of use described below, employing cavity closers in combination with auxiliary corner members to produce a self-supporting frame, forms the subject of published Patent Application No. 2 255 124A (Application No.

9207650.4), from which the present application is divided.

Each lower subframe corner is then formed by flitting within the channels 8 at the ends of two lengths of closer a flat L-shaped configurationally stabilising metal strap 17. Each such strap extends for part of the way along the channel 8 in the lower edge 13 and for part or all of the way up the channel 8 in side edge 15 or 16 (see Figure 2). It can if desired be adhered, or be held by the resilience of the walls of the channel 8.

The top 14 is then fitted, using two temporary plywood gussets 18, 19 wedged, one in each internal upper subframe corner1 within channels 7 in the adjacent side and top lengths. If, so desired, similar plywood gussets could be used in the bottom corners rather than the above-described straps. Where such a gusset is used in all four of the corners, a panel may be mounted upon the guests for closing the window aperture. Normally, such a panel would be transparent or translucent to allow light to pass and serve as a temporary seal for preventing rain or debris from entering the building under construction.

Alternatively the subframe members could simply be welded together - at top and/or bottom corners - to form.

rigid corners.

This subframe is laid upon the wall 1, 2, 3 at a desired location, with the horizontal portion of each metal stabilizing strap 17 lying within the cavity and accurately locating, both as to verticality and spacing, the upright sides 15 and 16. The side walls of brickwork can then be built accurately to the side pieces 15, 16, using metal wall ties 20 at desired locations to connect between the mortar in the joints of the brickwork and the shallow channels 9, 10 on the closer. When the upper level of the window is reached a conventional lintel 21 can be laid across the opening (see Figure 3), to cover ana accommodate the closer 3 create a thermal barrier and provide the usual support for further courses of brickwork.

In this way the necessity of using the actual window frame as a connecting and stabilizing member for the subframe units, so that they may present an accurate external periphery, is avoided. The window opening and subframe can be erected as described above and the actual window frame incorporated later (first of course removing the temporary plywood gussets) after any risk of damage has passed.

Channel 7 is an important feature for such subsequent mounting. For completeness, therefore, Figure 1 also shows some of the components of a subsequently mounted window frame assembly.

The periphery of the channel 7 can be given any suitable configuration, depending upon which components are intended to be inserted into the channel 7. The channel 7 shown in Figures 1 to 3 is generally rectangular in cross section and may, as shown in Figure 17, for example, comprise a series of fine ribs on each of its side walls. Such ribs serve to assist in the securing of a component fitted within the channel. Zn the case of the embodiments shown in Figures 1 and 3, the channel 7 ii used primarily for receiving the peripheral strip 22 and also for receiving corner pieces 18. In this case, the peripheral strip 22 is provided with a lug of generally similar thickness to the corner piece 18.

However, it may be that the channel 7 will be required to receive and support components having differing thicknesses. Therefore, Figures 4, 5 and 6 show alternative profile. for the channel 7.

In Figure 4, the channel 7 can be seen to include an outer region -71 of relatively broad cross section and an inner region 72 of relatively narrow cross section. The two are configured so that the channel 7 is generally symmetrical when viewed in cross section. The two regions 71 and 72 are connected by a pair of sloping walls 73 and 74 which lead from the broader region 71 into the narrower region 72. These walls 73 and 74 serve to assist in the location of a component such as a trim, for example, having a relatively narrow lug into the relatively narrow region 72 of the channel 7.

Figure 5 shows an alternative cross section for a channel 7, once again comprising an inner relatively narrow region 77 along with an outer relatively broad region 76. In this case, however, the two are not symmetrically aligned but instead they share a common straight wall 78. A feature, such as an engagement lug, of a component having a relatively narrow cross section may be inserted into the relatively narrow portion 77 of the channel 7 by first locating the feature up against wall 78, which can then be used to guide the connector into the narrow portion 77 of the channel 7.

Figure 6 shows yet another alternative profile for channel 7. In this case, each of the side walls of the channel is provided with a rib 79. These ribs 79 divide the channel 7 into an inner region 81 and an outer region 80. In use, the ribs 79 will serve as a stop to prevent further insertion of any component of a generally rectangular profile which is inserted into the channel 7.

The trim member now to be described with particular reference to Figure 7 forms the subject of published Patent Application No. 2 281 753A (Application No.

9420350.2).

Figure 7 shows a component 100 in the form of a trim member. The trim member 100 includes a lug 102 having a pair of elongate grooves 110, one of which runs along each side of the lug near to its distal end. The distal end of the lug is rounded-off to form a tip 112 which is part-circular in cross-section. If a lug such as the lug 102 of the trim 100 shown in Figure 7 is inserted into the channel 7, the tip can be forced past the ribs 79 which then engage respective ones of the grooves 110 to provide for a snap-fit engagement between the lug 102 and the channel 7.

It is to be understood that the various illustrated profiles for channel 7 are merely preferred embodiments and many other useful profiles could be used, depending upon the circumstances of ucie.

A peripheral strip 22 (see Figure 1) can be fixed in channel 7 to provide a guide and edge for finishing plaster 23. Strip 22 in turn presents an outwardly facing narrow channel 24, in which adjusting trim members 25 or window frame uprights can be fixed.

Internal and external sill structure 26, 27 can also be fitted with the closer profile as extending along the bottom of the subframe.

The lintel shown in Figure 3 can be seen to be open in cross section and, therefore, capable of receiving the upper horizontal cavity closer 4 within its body.

However, not all lintels commonly in use are open in this manner. Sometimes the bottom plate 32 of the lintel extends completely across the width of the lintel, and sometimes the lintel cavity 30 is filled, for example, with insulating material. Alternatively, it is not uncommon for such lintel cavities to be very narrow, thus providing insufficient space for receiving a cavity clover according to the present invention In such circumstances, a head section 40 such as the one shown in Figure 8 is used for the upper horizontal part of the subframe assembly, rather than a length of closer extrusion.

The head section 40 includes a baste portion 41 comprising plurality of generally V-sectioned, shallow recessed channels 42 for locating fixation means, such as screws, for fixing the head section to other subframe components. The position of the recessed channels 42 corresponds with the transverseposition of channels 44 provided in the cavity closer 4 shown in Figure 4, for example. Thus, when a strip of head section is placed with its base portion 41 against the end of a vertical closer, the vertical closer and the head section 40 can be fixed to be correctly aligned. It would, of course, be necessary to remove part of tongues 160 and 162 before fitting, to enable the end of the vertical section to contact the base portion 41 of the head section 40.

The present invention is especially concerned with a cavity closer extender. Thus, the width of a cavity in a cavity wall will vary from building to building.

This can be observed by a comparison of Figures 18 and 20, for example. In order to account for this, an additional cavity extender 50 is provided. An example of such a cavity extender is shown in Figure 9. The cavity extender shown in Figure 9 is designed for use with a cavity closer such as the one shown in Figure 4.

The cavity extender 50 is provided with a pair of spaced resilient lugs 52 which fit within open channel 60 positioned on- one side of the cavity closer 4. In order to fit the cavity extender within the cavity closer, the two lugs 52 are pushed against the lips 62 of the channel 60. The resilient lugs 63 each comprise an inclined surface 63 which slides across a corresponding inclined surface on each of the lips 62. The angled surfaces serve to deflect the two lugs towards each other and once the lugs are fully received within the channel 60, their resilience causes them to spring back out, thus locking the cavity extender in engagement with the cavity closer 4. The inclined surface 56 on the cavity extender mates with inclined surface 58 on the cavity closer, thus providing a stable assembly. The cavity extender is provided, in this case, with a flange 54, which corresponds to the flanges 5 and 6, although this is not necessary and could be omitted, if desired.

The inner and outer flanges 5 and 6 of the cavity closers shown in, for example, Figures 1, 4, 14 or 17 are optionally provided. In some circumstances it may be desirable for one or both of the flanges to be absent. For instance, where a wooden framed window is to be used, it is desirable for plaster to be provided right up to the window frame. Figures 10, 11 and 12 show three arrangements in which a flangeless cavity closer, as shown in Figure 13, is used. In each case, use is made of a trim piece such as the one shown in Figure 7. The trim piece may include a plaster guide 104. The trim piece may be manufactured to have a guide location or flange length to suit a particular circumstance of use. For instance, it can be seen that the plaster guide shown in Figure 11 is located inwardly relative to the plaster guide shown in Figure 10, whereas the trim shown in Figure 12 does not include a plaster guide at all. Furthermore, the trim piece shown in Figure 12 has a flange which lies flat against the end face of the wall on one side of the cavity only.

The embodiment of cavity closer shown in Figure 14 includes a pair of outwardly projecting flanges 150, 150.

These can be used in a similar fashion to the relatively narrower region 72 of the channel 7 shown in the embodiment of Figure 4 or the relatively narrow region 77 shown in Figure 5. That is to say they will provide a means for connecting a component having a relatively narrow thickness to the cavity closer. In this particular embodiment, however, the innermost of the two flanges also comprises a lip 152 which serves as a guide when plaster is applied. The head section shown in Figure 8 is provided with a similar pair of flanges 160, 160; these are optionally provided.

The plaster guide need not necessarily be provided exactly in this position but could be provided at any transverse position on the outwardly directed face of a closure member. Furthermore, such a plaster guide may be provided directly on the closure member, as in Figure 14 or, alternatively, on a trim member such as the one shown in Figure 7, or on a strip such as the strip 22 shown in Figure 1. A lip, such as lip 152, may or may not be provided, as preferred.

The outwardly directed face of the cavity closer 4 or any appropriate surface of a trim or plaster guide may comprise contours (such as ridges 208 shown in Figure 19) to facilitate the adhesion of plaster thereto.

Alternatively, a member with a textured surface may be affixed to the cavity closer 4 by means of, for example, channel 7.

A trim strip such as strip 200, shown in Figure 15 may be provided for finishing purposes and also to serve as a plaster guide. Figure 16 shows a similar strip, but with a lug 202 having a different configuration of the so-called 'Christmas tree' type. The lug would fit within a complementary channel provided in a closer, the channel comprising internal ridges spaced along its sides. An example of this is channel 204, shown in Figure 17.

Channel 7 shown in Figure 17 also includes a series of fine ribs 220 located on each of its side walls. These serve to anchor any component, such as a trim member or gusset fitted therein.

Many variations and modifications of the present invention will suggest themselves to a skilled addressee upon making reference to the foregoing description, which is given by way of illustrative example only, and which is not intended to limit the scope of the invention as defined by the appended claims.

Claims (12)

Claims

1. A subframe for a window comprising a plurality of elongate subframe members including at least two upright cavity closers each having a longitudinal channel at a side of the closer facing a leaf of the wall when the closer is located in the cavity between two leaves of a wall in which the window is to be provided, and a cavity closer extender having a complementary formation for engagement with the longitudinal channel of a cavity closer to adapt the width of the closer to the width of the cavity in which the closer is located.

2. A subframe according to claim 1, in which the extender engages with the closer as a snap-fit.

3. A subframe for a window according to claim 1 or claim 2, in which the extender includes an elongate flange along one side thereof, for locating against the end face of a leaf of the cavity wall during use to assist in control of the depth of the cavity closer and extender combination within the cavity.

4. A subframe according to any of claims 1 to 3, in which each cavity closer comprises an elongate chamber filled or partially filled with insulation material.

5. A subframe according to any of claims 1 to 4, in which each cavity closer is formed of extruded polymeric material.

6. A subframe according to claim 5, in which the extender is extruded of polymeric material.

7. A method of constructing a window opening comprising, in any appropriate order, the steps of: (A) constructing a self-supporting subframe which includes two upright cavity closers, a sill member also serving as a cavity closer, and a head strip which may also be a cavity closer, (B) locating the subframe over a run of cavity wall with its sill member substantially closing the cavity, (C) connecting at least one cavity closer extender to the subframe to adapt the width of the closer to the width of the cavity in which the closer is located, (D) building the window opening around the located subframe.

8. A cavity closer extender having an elongate formation on one side thereof for engagement with a complementary formation on a side portion of a cavity closer, the said cavity closer extender serving, in use, to extend the effective width of the cavity closer to which it is attached.

9. A cavity closer extender as claimed in claim 8, in which the extender includes an elongate flange along one side thereof, for locating against the end face of a leaf of the cavity wall during use to assist in control of the depth of the cavity closer and extender combination within the cavity.

10. A subframe for a window as claimed in claim 1 and substantially as hereinbefore described.

11. A method of constructing a window opening as claimed in claim 7 and substantially as hereinbefore described.

12. A cavity closer extender as claimed in claim 8 and substantially as hereinbefore described.