GB2277756A

GB2277756A - Cavity closures

Info

Publication number: GB2277756A
Application number: GB9407334A
Authority: GB
Inventors: Brian Christopher Webster
Original assignee: Anglian Windows Ltd
Current assignee: Anglian Windows Ltd
Priority date: 1993-05-08
Filing date: 1994-04-13
Publication date: 1994-11-09
Anticipated expiration: 2014-04-13
Also published as: GB2277756B; GB9407334D0

Abstract

A cavity closure for an opening in a building wall at which a window or door is to be inserted, comprising two U-shaped plastics extrusions (10, 10A) which can be interengaged together by means of fittings (12, 14, 16) to form a rectangular box-section member optionally of differing longer dimensions, so as to provide for the closure of cavities of three differing cavity widths according to the way in which the two elements are interengaged and the orientation in which the box-section is located in the cavity. <IMAGE>

Description

Improvements in Cavity Closures This invention relates to a cavity closure.

As used herein, the term "cavity closure" is intended to refer to a closure for the wall cavity at the periphery of an opening formed in the wall of a building to receive a window or door.

The cavity closure subject of this invention may also be a former around which brickwork and/or blockwork is erected to form the window or door opening.

Moreover, the cavity closure subject of this invention may also be but is not necessarily a window or door acceptor which serves after the wall has been built around the closure to receive and locate a window or door in the closed-cavity opening.

According to the invention, there is provided a cavity closure which, for any one or more sides of the opening formed or to be formed around the closure, comprises at least two closure elements which can be interengaged to form a closure having a portion which will extend into the cavity from the side of the opening with a spacing suited to the spacing between the cavity-defining walls, the closure elements being so formed that they can be interengaged in any one of a plurality of relative positions such that the portions which will project into the cavity are spaced to suit any one of a plurality of different cavity-defining wall spacings.

Thus, currently buildings are erected with 50 mm, 65 mm or 75 mm cavity-defining wall spacings, as necessary to achieve satisfactory thermal insulation. A smaller spacing can be adopted if the internal wall is erected with blocks which inherently have good insulative properties.

A described embodiment of the invention provides a closure which, with the same two closure elements, can be assembled to suit cavity-defining wall spacings of 50 to 64 mm, 65 to 74 mm and 75 to 89 mm. However, by addition of extension elements, a cavity-defining wall spacing of 90 to 105 mm can be catered for, if this is necessary in view of demands for higher U-values.

In a preferred embodiment of the invention, two elements push-fit or snap-fit together to form a member of rectangular box section. This member may be located in the cavity with either its shorter first dimension or its longer second dimension extending across the width of the cavity, thereby to suit cavity widths of 50 to 64 mm or cavity widths of 65 to 74 mm. Moreover, the two elements alternatively push-fit or snap-fit together in a relationship which increases the first dimension to a third dimension greater than the unchanged second dimension, whereby the resulting box-section member will locate in a cavity of width 75 to 89 mm.

Yet again, it is preferably also possible to push-fit or snap-fit the two members together with intervening extension strips to form a still more elongate box-section member which will suit a cavity width of 90 to 105 mm.

Alternatively, instead of using extension strips, two differently dimensioned closure elements may be assembled to suit a cavity width of 90 to 105 mm.

In all arrangements, the box-section presents at the end of the cavity at which the window or door opening is formed (built or more usually to be built around the closure), fittings which enable a reveal leg and/or a plaster trim and/or a connecting piece for a window frame to be push-fitted or snap-fitted to the box-section closure, and preferably also a fitting, on a side of the box member within the cayity, to which a fixing lug to be embedded in the wall, may be attached. The latter fittings preferably enable two fixing lugs to be fitted, respectively to be embedded in the inner and outer leaves of the wall.

The two basic elements which push-fit or snap-fit together to form the box-section member are preferably generally of a U-section, which fix together either with the legs overlapping, thereby to form the smaller boxsection member, or with the legs end to end, thereby to form the larger box-section member. Extension strips acting as spacers between the free ends of the limbs of the two basic members can enable the more elongate larger box-section member to be assembled.

The cavity closure is preferably made of PVCU plastics material, and the two basic elements generally of Usection comprise extrusions which may be identical.

The interior of the box-section member which forms the cavity closure may be filled with heat insulating material.

The cavity closure in accordance with the invention is now described by way of example with reference to the accompanying drawings, in which: Figure 1 shows a basic PVCU extrusion; Figures 2 to 4 respectively show alternative manners of assembling two basic extrusions to form closures applied to wall cavities of differing widths; Figure 5 shows a PVCU extension piece; Figure 6 shows a modified cavity closure assembled with the aid of extension pieces; Figure 7 shows, in diagrammatic manner, a cavity closure frame constructed using closure members in accordance with the invention; Figures 8 and 8A show alternative ways of fitting a window frame in position in an opening where a cavity closure is provided; Figures 9 and 9A show, in like manner to Figures 8 and 8A, alternative ways of fixing a frame in position to an opening where a 65 mm cavity closure is provided; Figure 10 shows a reveal leg; Figure 11 shows the assembly of two reveal legs to a cavity closure; Figure 12 illustrates fixing in position of the cavity closure in the cavity by use of a fixing lug; Figure 13 shows a plaster trim; Figure 14 shows the assembly of the plaster trim to the cavity closure; and Figures 15, 15A and 16 illustrate differing ways of fixing a PVCU window frame in position in a wall opening at which the wall cavity is closed by the cavity closure.

Referring to Figure 1, there is shown a UPVC plastics extrusion 10 which is generally of U-section. The element is extruded with a number of shapings which constitute fittings for a variety of purposes. First the fittings 12, 14, 16 are referred to.

By virtue of the fittings 12 and 16, two identical extrusions 10, lOA can be snap-fitted together in the manner shown in Figure 2. Alternatively, by use of the fittings 14 and 16, the two elements can be snap-fitted together in the manner shown in Figure 4. In the first case a box-section member 18 is formed; in the second case a box-section member 18A is formed.

Figure 2 shows the cavity closure constituted by the boxsection member 18 located in position to close a 50 mm wide wall cavity at a window opening.

Figure 3 shows the same cavity closure 18 turned through a right angle to close a 65 mm wide wall cavity at a window opening.

Figure 4 shows the cavity closure constituted by the boxsection member 18A located in position to close a 75 mm wall cavity at the window opening.

Referring to Figure 5, there is shown an extension piece 20. Figure 6 shows that two extension pieces 20 may be used to interconnect between two U-section extrusions 10, 10A at the fittings 14 and 16, thereby to form a more elongate larger box-section member 22.

Figure 6 also shows that the box-section member 22 can be located in position to close a 90 mm wall cavity at a window opening.

In practice, and especially when the closure is also used as an opening former around which the brickwork and/or blockwork is built, then as shown in Figure 7 three lengths of box-section cavity closure member 18A, 18B and 18C (or 22A, 22B and 22C) are fixed together by fixing screws 62 to form the bottom and two vertical sides of the cavity closure around which the window or door opening is to be formed. Additionally, a length of steel angle 64 constituting a tie bar is screwed in place, by means of screws 62A, across the top of the closure where a lintel is to be provided.

For convenience and clarity, in Figure 7 the fittings formed in the box-section for plaster trim and/or window acceptor elements are omitted, and only the slot 36 for a fixing lug is indicated. Additionally, however, the slots 34 which can be used to fit one or more reveal legs are shown. Importantly, these are also used as ports for receiving the screws 62 and 62A, in particular as indicated by the dashed lines 66 which pass through jigged holes 68 formed in the wall of the box-section lengths and likewise punched holes 70 in the steel tie bar 64. Hole 72 in the steel tie bar 64 defines a means for fixing to temporary jambs to ensure exact upright positioning of the closure while it is built in.

Figure 7 is especially applicable to the construction of a cavity closure to serve as a former on site, but for standard size windows, at least the three cavity closure members 18A, 18B and 18C (or 22A, 22B and 22C) may be factory assembled.

Whether supplied to the site as unassembled lengths or as an assembled frame, a reveal leg will commonly be assembled to the frame in the factory, as referred to later.

In Figure 8, a timber window frame 24 is shown fixed in a set back position in the window opening, generally in line with the cavity closure 18. Fixing of the window frame is in this case effected at 26. In Figure 8A, the window frame 24A is set forward, and fixed in position at 28. The same manner of window frame fixing is possible for all dimensions of wall cavity width and cavity closure. Thus, Figures 9 and 9A show, in like manner, the fixing of the window frame 24 or 24A in a closure for a 65 mm cavity.

Figures 8, 8A, 9 and 9A also show thermal insulation 30 filled within the box-section cavity closure 18, and a reveal leg 32, shown separately in Figure 10, which engages in a recessed slot 34 in one corner of the boxsection closure. If required, as shown in Figure 11, two reveal legs 32, 32A may be fitted. In this respect it is important to note that two slots 34 are available at the two exposed corners of the box-section closure 18, 18A or 22, and in both orientations of the box-section closure 18.

The fittings 36 on the basic U-section extrusions are also to be noted. Figure 11 shows a fixing lug 38 secured to the cavity closure 18 by use of one of the fittings 36.

The same fixing lug 38 can be employed when the cavity closure 18 is in the orientation at right angles, as shown in Figure 12.

Figure 13 shows a trim 40 for plaster work. This trim 40, in the manner exemplified in Figure 14, may be secured in any one of the fittings 42, 44 or 46 when on the exposed side of the box-section closure 18, 18A or 22. Figure 14 shows the fitting 44 in use.

Figure 15 again shows the cavity closure 18 located in position in a 50 mm wall cavity by means of fixing lugs 38, but in this case a modified trim 48 is employed, secured in the fitting 44 of the fittings 42, 44, 46.

This trim 48 has an extension fitting 50 enabling it directly to accept a PVCU extruded window frame 52.

Thus, in combination with the trim 48, the cavity closure 18, 18A or 22 can also constitute a window acceptor.

It will, however, be clear from Figure 15A that the PVCU window frame 52 may instead be fixed in position by means of a fixing lug 54.

Finally, to complete understanding of the cavity closure, Figure 16 shows the arrangement at the sill of a window.

Similar reference numerals are employed to those of preceding figures, but the sill member 56 and its fixing 58 are shown, together with an interior reveal leg 32.

Usually, however, an interior reveal leg will not be required.

The above-described arrangements can also be used in relation to cavity closures at door openings, as well as window openings.

Claims

1. A cavity closure which, for any one or more sides of the opening formed or to be formed around the closure, comprises at least two closure elements which can be interengaged to form a closure having a portion which will extend into the cavity from the side of the opening with a spacing suited to the spacing between the cavity-defining walls, the closure elements being so formed that they can be interengaged in any one of a plurality of relative positions such that the portions which will project into the cavity are spaced to suit any one of a plurality of different cavity-defining wall spacings.

2. A cavity closure according to claim 1, wherein the two elements push-fit or snap-fit together to form a member of rectangular box-section.

3. A cavity closure according to claim 2, wherein each element is generally of U-section.

4. A cavity closure according to claim 3, wherein the two elements carry fittings enabling them to be interfitted as a rectangular box-section having the option of either one of two differing longer dimensions.

5. A cavity closure according to claim 4, in combination with extension elements which can be interposed between the two U-section elements to provide a rectangular box-section member of a third differing longer dimension.

6. A cavity closure according to any of claims 1 to 5, having fittings for the attachment of other elements thereto, the assembled elements providing a rectangular box-section which presents similar attachment fittings both along the side of its shorter dimension and the side of its longer dimension.

7. A cavity closure according to any of claims 1 to 6, wherein the two elements are extruded elements.

8. A cavity closure according to claim 7, wherein the elements are made of extruded PVC.

9. A cavity closure arroding to any of claims 1 to 8, having thermal insulation inserted within the box-section.

10. A cavity closure according to claim 2 or any claim appendant thereto, in which the box section member carries attachment fittings for a reveal leg and for a plaster trim and/or window or door frame accepting element.

11. A cavity closure according to claim 10, wherein the reveal leg fitting comprises an undercut slot at each corner of the box-section.

12. A cavity closure according to claim 10 or claim 11, wherein the fitting for a plaster trim and/or window accepting element comprises one or more hook-shaped projections on each side of the box-section.

13. A cavity closure according to any of claims 10 to 12, in combination with one or more reveal legs.

14. A cavity closure according to any of claims 10 to 13, in combination with a plaster trim and/or window accepting element.

15. A cavity closure surround for a window or door opening in a building wall, comprising three or four lengths of box-section comprising a cavity closure according to any of claims 1 to 14, cut to length and secured together to define at least the bottom and sides of the periphery of the opening.

16. A cavity closure according to claim 15 when appendant to claim 11, in which the undercut slots are employed as screw ports for fixing the lengths of box-section together at the corners of the surround.

17. A cavity closure surround according to claim 15 or claim 16, wherein the brickwork and/or blockwork forming the wall is erected around the closure, which thereby also constitutes a former for the window or door opening.

18. A cavity closure as claimed in claim 1 and substantially as hereinbefore described with reference to the accompanying drawings.