IE80649B1 - Improvements in or relating to window or door assemblies - Google Patents

Abstract

A sub-frame built into the window aperture of a building may receive a window frame (9) by a push-in action. The sub-frame has side rails (6,8) and a bottom rail each with cavity closers (44). The top rail provides an external hood over the window frame and provides an effective ventilation pathway from the inside of the building to the outside, the outside ventilation opening being in an under-wall of the hood. .

Description

This invention relates to sub-frames for the fitting therein of frames for windows or doors. The invention relates particularly, though not exclusively, to subframes having parts which act as cavity closers, located in the cavity between inner and outer leaves of a cavity wall.

It is known to construct a rectangular sub-frame made up of extruded profiles at least some of which have a cavity closer which is to be located, in the finished building, in the cavity between the inner and outer leaves of a cavity wall. The sub-frame may be used as a former to aid the building of the leaves. Examples are given in WO 91/14066.

Once the wall has been built around the sub-frame, a frame for a window or door panel can be fitted into the sub-frame. The panel may already be in the said frame or may be fitted therein subsequently.

There is a requirement to provide ventilation between the interior of the building and the exterior. The standard approach is to provide ventilation openings through the frame of the door or window. Another approach which has been proposed is to use a gap between the frame of the door or window and the sub-frame, for ventilation.

Both of these approaches have considerable drawbacks and we have now appreciated that there are considerable advantages in providing a ventilation pathway within the sub-frame itself. ό 49 - 2 In accordance with the present invention there is provided a sub-frame into which the frame of a window or door panel is to be fitted, the sub-frame comprising: two side rails and one bottom rail each of which has a base wall adapted on one face to engage the frame of the window or door panel; and a top rail spanning the upper ends of the side rails, the top rail being of hollow box section and having a base wall adapted on its underside to engage the frame of the window or door panel, a rear portion to be located internally of the building and a front wall portion to be located externally, and ventilation openings therethrough to allow air communication between the inside and outside of the building.

Preferably the sub-frame is for a new-build situation, and the leaves of a wall may be built around it. Suitably at least the side rails, and preferably also the bottom rail, have cavity closers which are located, in use, within the cavity between the wall leaves. Suitably they span the entire width of the cavity. The top rail which permits air communication could be designed with a cavity closer but preferably is not, since a top rail without a cavity closer may be used irrespective of the design of lintel specified by the architect.

Preferably, the front wall portion of the top rail provides a hood projecting outwardly over the window frame. This improves the weather resistance of the fitted window or door. The hood may be comprised by an upper wall which slopes downwards in the outward direction, and an under-wall. The under-wall preferably has a ventilation opening or openings. The under-wall may be generally horizontal, but preferably slopes downwards in the outward direction, but at a lesser angle to the horizontal than the upper wall of the hood. The hood may include a drainage opening or openings through the base wall of the top rail, located inwardly of the ventilation opening or openings.

The rear wall portion preferably comprises an upright wall which has a ventilation opening or openings. Suitably the ventilation opening or openings is/are under the control of damper means, which a user may operate from the inside of the building, in order to control the degree of ventilation.

The top rail may have one or more internal strengthening walls, and the or each said strengthening wall has an opening or openings not less in area than the opening or openings of either of the front wall portion, or the rear wall portion. Generally the area of the ventilation opening or openings of the front wall portion is substantially equal to that of the ventilation opening or openings at the rear wall portion.

Preferably, the top rail is formed with at least one screw port, preferably located within the hollow box section, to receive a screw from the respective side rail. Preferably there are two screw ports.

Preferably, the side rails and bottom rail are of the type described in WO 91/14066. A cavity closer, when present, is preferably carried at an intermediate position on the base wall. The base wall of the side rails, and suitably also the base wall of the bottom rail, preferably has at least one engagement tooth, to engage spring fixing cleats carried by the frame of the window or door, so that the window or door may be fitted into the sub-frame with a snap-fit action. Preferably, the base wall of the top rail also carries at least one such engagement tooth. The base wall of each of the side rails suitably carries, on its face which has said engagement tooth, an abutment to limit the movement of the window or door frame relative to the sub-frame, and which also may serve as a plaster guide. In the context of this invention these abutments may also assist the correct engagement of the top rail with the side rails: preferably, the said rear wall portion of the top rail abuts against or is aligned with the abutments of the side rails. Preferably the base wall of the bottom rail also has an abutment, aligned with the abutments of the side rail.

The rear wall portion of the top rail preferably has an extension beyond the base wall, which extension can itself serve as an abutment to limit the inward movement of the frame of the door or window, when the frame of the door or window is fitted in place.

Preferably, the rails of the sub-frame of the invention are UPVC extrusions.

The invention will now be further described, by way of example, with reference to the accompanying drawings, in which Fig. 1 is a cross-sectional view of a first > embodiment of top rail of a sub-frame of the invention, and the top rail of a frame of a door or window, fitted thereto; Fig. 2 is a perspective view of the sub-frame including the top rail of Fig. 1, and the frame of a window or door, about to be fitted thereinto; and Fig. 3 is a cross-sectional view of a second embodiment of top rail of a sub-frame of the invention, and the top rail of a frame of a door or window, fitted thereto.

In Fig. 1, the top rail of the sub-frame which is built into a wall (not shown) is designated as 2, and the top rail of the frame of a door or window, secured into the sub-frame, is designated as 4.

Fig. 2 shows the entire sub-frame, comprising the top rail 2, side rails 6 and 8, and the bottom rail 10; and the frame 9 of the door or window.

The top rail of the sub-frame is a UPVC extrusion of hollow box section. It has a base wall 12, a rear wall 14, a top wall 16, and a front hood portion 18, projecting outwardly (that is to the exterior of the building) comprising a slant wall 20 and a horizontal under-wall 22. The under-wall 22 is connected to the base wall 12 by a short return 24. There are three sections within the top rail, as a result of the provision of two internal strengthening walls 26, 28. The rear wall 14 has a downward extension 30 beyond the base wall 12. Within the top rail, carried by the base wall 12 and top wall 16 respectively, are screw ports 32, 34. The outer side of the base wall 12 is formed with a series of engagement teeth, in the manner and for the purpose described in WO 91/14066. Accordingly they will not be described in detail herein.

A ventilation pathway is provided through the top rail 2. A rectangular slot 36 is provided within the rear wall 14. A rectangular slot 38 is provided in the underwall 22. Rectangular slots are also provided within the internal walls 26, 28. All of these slots are of the same area and in this embodiment that area is 8,000mm2. The amount of this area which is used is controlled by a standard manually-operated damper 40 carried by the rear wall 14, internally of the building, in use. The rectangular slot 38 in the under-wall 22 is covered by an external grille 41.

The side rails are of the type described in WO 10 91/14066 and a full description is not necessary here.

However, briefly, each side rail comprises a base wall 42, a cavity closer 44 carried by the base wall in a central region thereof, and an abutment 46, extending from the opposite side of the base wall, to the cavity closer. The base wall has teeth identical to the teeth of the base wall 12 of the top rail 2, as shown in Fig. 1, these teeth being to the exterior side of the abutment. The abutment 46 is adjacent to the rear wall 14 of the top rail. The rear wall 14 and the abutment 46 may be in face to face contact, or the abutment may be aligned with the rear wall, with the rear wall having cut-outs at each end to accommodate the abutment.

It should be noted that each side rail is secured to the top rail by means of two screws 48, 50, each of which passes through the side rail, into a respective screw port 32, 34. One screw 48 passes only through the base wall 42 of the respective side rail to the external side of the cavity closer. The other screw passes through the cavity closer, through side chambers just to the side of the central insulated core of the cavity closer.

Once the wall has been built up around the sub-frame, with bricks and blocks against the sides of the cavity closers and against the base wall flanks to the sides of the cavity closers, and with a lintel placed across the top of the opening, the frame of the window or door may be pushed into place, from the outside of the building in this embodiment, as shown in Fig. 1. It is not necessary to describe the characteristics of the frame of the door or window in any detail in this specification. Suffice it to say that, in this embodiment, spring steel fixing cleats 52 are used, to resiliently engage against teeth of the base walls, as shown in Fig. 1. There is no provision for ventilation through the frame of the door or window, nor through the gap between the sub-frame and the frame of the door or window, the gap being closed on the inside by the abutment of the extension 30 of rear wall 14 of the top rail, and the frame of the door or window, and on the external side, by means of a sealing strip 54 and, to the outside thereof, a mastic sealant 56.

Fig. 3 shows a second embodiment of sub-frame, which differs from the first embodiment only in relation to the design of the underpart of the front hood. The first difference is that the under-wall 22 is set at an angle to the horizontal, being slanted downwardly in the outward direction. The second difference is that the return 24 has an extension 60 above the under-wall 22. The third difference is that the base wall 12 has a slot 62, or slots, adjacent to the return 24 and running parallel to the slot 38. The fourth difference is that a transverse wall portion 64, internal to the top rail and parallel to the return 24, projects from the base wall. This transverse wall portion 64 may have perforations adjacent to the base wall to allow water to pass through. These differences together improve the water resistance of the top rail. In the unlikely event that water passes through the rectangular ventilation slot 38 to flow over the extension 60, the slot 62, or slots, and the transverse wall portion 64 will together assist water to run out of the top rail. Beyond that, the further slot 62, or slots, provides additional ventilation.

There are substantial advantages in providing a ventilation pathway through the sub-frame, rather than through the frame of a door or window, as previously carried out. These include the following:the structural integrity of the frame of the door or window is not affected. We consider it more structurally sound to provide openings through the subframe, which is generally a more substantial part and which is rigidly secured in place, by being built into the walls. a greater degree of ventilation can be provided. Frames of windows or doors are becoming very slim, and this means that only relatively narrow openings can be provided therein. it is aesthetically more appealing, because the internal ventilation openings are provided further away from the window or door panel. The window or door panel itself has the same appearance on each of its four sides. No longer does one side look different, as a result either of having an opening formed in it (possibly a very long opening because of the slimness of the frame) . In an alternative prior art approach an add-on profile to the window frame (shown for example in Fig. 3 of GB 2275718A) is not of attractive appearance. - the ventilation pathway may, if wished, terminate in an external hood, to give improved weatherproofing. The use of an external hood also helps to screen the lintel from external view. - there are no problems in designing or opening 5 sliding sash windows. With such windows there can be problems with opening clearances, when a ventilation damper is fitted internally, on the frame of the window.

The reader's attention is directed to all papers and 10 documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings), may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

Claims (12)

1. A sub-frame into which the frame of a window or door panel is to be fitted, the sub-frame comprising: two side rails and one bottom rail each of which has a base wall adapted on one face to engage the frame of the window or door panel; and a top rail spanning the upper ends of the side rails, the top rail being of hollow box section and having a base wall adapted on its underside to engage the frame of the window or door panel, a rear portion to be located internally of the building and a front wall portion to be located externally, and ventilation openings therethrough to allow air communication between the inside and outside of the building.

2. A sub-frame as claimed in Claim 1, wherein the side rails and bottom rail have cavity closers which are located, in use, within the cavity between the wall leaves.

3. A sub-frame as claimed in Claim 1 or 2, wherein the front wall portion of the top rail provides a hood projecting outwardly over the window frame.

4. A sub-frame as claimed in Claim 3, wherein the hood comprises an upper wall which slopes downwards in the outward direction, and an under-wall which has a ventilation opening.

5. A sub-frame as claimed in Claim 3 or 4, wherein the hood includes a drainage opening through the base wall, located inwardly of the ventilation opening.

6. A sub-frame as claimed in any preceding claim, wherein the rear wall portion comprises an upright wall which has a ventilation opening which is under the control of damper means.

7. A sub-frame as claimed in any preceding claim, wherein the top rail is formed with at least one screw port to receive a screw from the respective side rail.

8. A sub-frame as claimed in any preceding claim, wherein the base walls of at least the side rails have at least one engagement tooth, to engage spring fixing cleats carried by the frame of the window or door.

9. A sub-frame as claimed in any preceding claim, wherein the base walls of at least the side rails each have an abutment to limit the movement of the window or door frame, relative to the sub-frame.

10. A sub-frame as claimed in Claim 9, wherein the rear wall portion of the top rail abuts against or is aligned with the abutments of the side rails.

11. A sub-frame substantially as hereinbefore described with reference to the drawings.

12. A top rail for a sub-frame, the top rail having a ventilation pathway and being substantially as hereinbefore described with reference to the accompanying drawings.