GB2306992A - Cavity closer for window or door sub frames - Google Patents

Abstract

A UPVC cavity closer profile has a base wall and a cavity closer. The cavity closer profile has a screw-receiving formation 17 to one side of its enclosed core. Cavity closer profiles are secured together to make a rectangular sub-frame about which wall leaves may be built. Then, an inner window or door frame is pushed into the sub-frame, up to an abutment 28 on the base wall. Screws 40 are screwed through the window or door frame and into the screw-receiving formations 17. An infill panel, for example a glazing panel, is then fitted within the inner frame.

Description

IMPROVEMENT8 IN OR RELATING TO WINDOW OR DOOR A88EMBtXES This invention relates to the fitting of frames for mounting windows or doors into sub-frames built into a building. The invention relates in particular to the fitting of frames for windows or doors, into sub-frames having parts which act as cavity closers, located in the cavity between inner and outer leaves of a cavity wall.

Various ways have been proposed before, for fitting the frame of a door or window into a sub-frame. A first general approach is to employ fixing means to secure the window or door frame in its correct location in the subframe, with the fixing means being engaged in place after the window or door has been moved to that location. A general problem with this approach is that the window or door frame, which may often be glazed and so may be heavy and unwieldy, must be held in place whilst the fixing means are engaged in place.

In one such arrangement, described in GB-A-2275718, the sub-frame has an upstand and the window or door frame is pushed into the sub-frame, up to the upstand; then, a retaining bead is fitted in place to prevent the window or door frame disengaging from the sub-frame. In another arrangement the sub-frame and the window or door frame are screwed together. However, the respective parts are often not properly designed to take screws, and various problems may ensue as a result. Most commonly screws will pierce the wall of the central core of a cavity closer, this central region generally containing insulation. They gain no purchase form the insulation and must rely essentially on the purchase they obtain in the narrow wall region of the cavity closer.Moreover, it is normally thought undesirable to pierce the wall of the cavity closer, so giving the possibility of moisture seeping into the insulated core.

Some systems employ snap-in features which mean that when the window or door frame is located in the sub-frame, the act of locating it brings about securement. In one example, the snap-in action is achieved by metal plates of spring steel, as described in EP-B-356430, fitted to the window or door frame and engaging with a tooth or teeth on a specially designed sub-frame, as described in EP-A521922. Another example is given in GB-B-2211535, in which example the window or door frame has a co-moulded resilient leg, which clips over a part of the sub-frame.

Such methods are disadvantageous in certain circumstances, in particular for large windows and/or for windows with hinged lights. In such cases the frame of the window may bow out from the sub-frame in between the corners, a phenomenon known as "bellying". Even when such methods should be satisfactory many builders will prefer not to rely on such "automatic" securement.

In accordance with a first aspect of the invention there is provided a cavity closer profile for use in assembling a sub-frame, the profile having a base wall and a cavity closer carried on one side of the base wall, such that the cavity closer may be received in the cavity between two wall leaves, with the base wall extending from one leaf to the other, characterised in that the cavity closer has an enclosed core, and a screw-receiving formation separate from the enclosed core; such that a screw may be passed through a window or door frame located on the sub-frame, through the base wall of the sub-frame, and into the screw-receiving formation.

In accordance with a second aspect of the invention there is provided an assembly of a cavity closer profile as defined in the previous paragraph, and a window or door frame profile for use in assembling a window or door frame, the window or door frame profile being engagable on the cavity closer profile, such that a screw may be passed through the window or door frame profile, through the base wall of the sub-frame, and into the said screw receiving formation of the cavity closer profile. Preferably the screw head is then at a part of the window or door frame profile, which, in the assembled window or door, is not seen.

Preferably, in the assembly as defined in the previous paragraph, there are means, for example an abutment formed on the cavity closer profile, on the side of the base wall opposite to the cavity closer, for determining the correct location of the wall or door frame profile on the cavity closer profile. As a result, the cavity closer profile may be provided with a marking, for example a line along the profile, to show where screws should be inserted, for correct location in the screw receiving formation of the cavity closer profile.

Preferably, the cavity closer profile is an extrusion and the screw receiving formation extends along the length of the profile, to one side of the cavity closer.

In addition to screws, additional means may be provided, for securing the window or door frame profile to the cavity closer profile. Preferably such means provide "automatic" securement between the parts, that is to say, the action of bringing the parts together brings about securement. For example, fixing means of spring steel, each having one or more resilient legs, may be secured to the window or door frame profile for engagement with a tooth or teeth defined on the base wall of the cavity closer profile. Examples of suitable fixing means are given in EP-B-356430.

The screw receiving formation may suitably comprise a plurality of chambers to one side of the enclosed core, with the cross-wall(s) between the chambers providing purchase for screws.

Preferably, the assembly defined above includes screws of size to extend to, but not through, the base of the screw-receiving formation.

In accordance with a third aspect of the invention there is defined a former, being an assembly of cavity closer profiles in accordance with the first aspect of the invention, about which former the leaves may be built.

The former defines a shape which is square or rectangular, and may have three such cavity closer profiles, or, more preferably four, as sides thereof.

In accordance with a fourth aspect of the invention there is provided an assembly of a sub-frame, having four sides, of which at least three comprise cavity closer profiles in accordance with the first aspect of the present invention; and a window or door frame, having four sides made up of window or door frame profiles, secured to the sub-frame by screws engaged in the screw-receiving formations, without piercing of the said enclosed cores.

In accordance with a fifth aspect of the invention there is provided a method of fitting a window or door, as defined above. Preferably the glazing panel for a window or door is located in place after the window or door frame has been secured to the sub-frame, as defined herein.

Preferably the heads of screws are thereby covered.

The invention will now be further described, by way of example, with reference to the accompanying drawings in which: figure 1 is a perspective view of a cavity closer profile; and figure 2 is a cross-sectional view of a window frame profile secured to the cavity closer profile, in accordance with the invention.

With reference firstly to figure 1, the cavity closer profile, which is a UPVC extrusion, comprises a base wall 2 which carries, on one side, a cavity closer 4.

The cavity closer 4 has an enclosed, generally rectangular, core 6 which may be filled with an insulating material (see figure 2). To one side of the core there is side formation 8 comprising, next to the base member, a smaller enclosed chamber 10 and, then, a larger enclosed chamber 12. The smaller chamber has opposed small ridges 11, extending perpendicularly to the plane of the base wall 2. On this same side of the core, at the corner thereof, there is a further, small, chamber 14, not fully enclosed, but communicating with the core. There is a space 16 between the formation 8 and the chamber 14. This space 16 is generally wedge-shaped, being wider towards the core and narrower away from it. The purpose of this space 16 is to receive an end portion of a brick tie (not shown).

On the other side of the core 6, there is a side formation 17, of the same external shape as side formation 12, but made up of three small chambers 18, 19, 20, separated by transverse walls 21, 22. The purpose of this extra structure is to provide purchase for a screw, as will be described later. On this same side of the core, at the corner thereof there is a further small chamber 24 which is identical to the chamber 14. There is a space 26 between the formation 18 and the chamber 24, identical to the space 16, to receive an end portion of a brick tie (not shown). The small chambers 10, 18 adjacent to the base wall are identical in shape and size to each other.

On the other side of the base wall 2 from the cavity closer, there is provided an abutment 28 which serves two purposes. Firstly it serves to determine the location of a window or door frame member, as will be described later.

Secondly it acts as a plaster guide and key, for subsequent plastering work, after fitting of the window or door frame. To one side of the abutment 28, which side is to be internal, there is a series of small upstands 30, to aid plaster keying. To the other side of the abutment 28, towards the outside after fitment, the base wall is formed with a series of teeth 32, these being present in order to engage spring plates carried by a window or door frame.

However, above the side formation 17 there is a shallow Vshaped formation 34 instead of teeth 32.

Use of the profile shown in figure 1 will now be described with reference to figure 2.

The sub-frame is made up of three or four profiles of the type showr. in figure 1. Four may be used when the lintel which will be fitted above the door or window in question has a cavity to receive the cavity closer. When the lintel is not of this type, three are used, together with a special flat head profile, as the fourth profile.

Since this does not have the features to which this invention relates, it need not be described further.

Once the square or rectangular sub-frame, comprising three or four of the profiles shown in figure 1, has been constructed, the wall leaves are built around it. The sub-frame acts as a former, as the outer leaf 36 and inner leaf 38 are built up. Once the brick work and block work are completed, and the lintel has been secured in place, the window or door frame may be engaged within the subframe. In this embodiment the window or door frame is fitted with metal fixings as described in EP-B-356430.

These cooperate with the teeth 32, and retain the window or door frame within the sub-frame. On assembly the window or door frame is pushed along the sub-frame until it can go no further, because of the abutment 28. The window or door frame profiles have a longitudinal groove (not shown) showing where the builder may then, if wished, insert screws, in order to have them engage within the side formations 17. The builder does not have to use screws because adequate securement is provided by the metal fixings. However many builders like to have an additional level of securement. Screws are provided, of the correct length to pass to the bottom of the formation 18, but not through the bottom. The screws extend through each of the cross walls 21, 22 within the formation, so providing good purchase.Additional purchase is obtained by the engagement of the screw with the small ridges such as 38 within the formation.

Once the screws have been inserted, into the position shown by the screw 40 in figure 2, the glazing panel may be secured in place in standard manner, and the screw heads are thereby hidden.

The reader's attention is directed to all papers and 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.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

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.

The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims (14)

CLAfMB

1. A cavity closer profile for use in assembling a sub frame, the profile having a base wall and a cavity closer carried on one side of the base wall, such that the cavity closer may be received in the cavity between two wall leaves, with the base wall extending from one leaf to the other, characterised in that the cavity clover has an enclosed core, and a screw receiving formation separate from the enclosed core; such that a screw may be passed through a window or door frame located on the sub-frame, through the base wall of the sub-frame, and into the screw-receiving formation.

2. A cavity closer profile as claimed in Claim 1, wherein additional means is provided, for securing the window or door frame profile to the cavity closer profile, such means providing "automatic" securement between the parts, whereby the acting of bringing the parts together brings about securement.

3. A cavity closer profile as claimed in Claim 2, wherein fixing means of spring steel, each having one or more resilient legs, are secured to the window or door frame profile for engagement with a tooth or teeth defined on the base wall of the cavity closer profile.

4. A cavity closer profile as claimed in any preceding claim, wherein the screw-receiving formation comprises a plurality of aligned chambers to one side of the enclosed core, with the cross-wall(s) between the chambers providing purchase for screws.

5. A cavity closer profile as claimed in any preceding claim, wherein the cavity closer profile is an extrusion and the screw-receiving formation extends along the length of the profile, to one side of the cavity closer.

6. An assembly of a cavity closer profile as claimed in any preceding claim, and a window or door frame profile for a window or door frame, the window or door frame profile being engageable on the cavity closer profile, such that a screw may be passed through the window or door frame profile, through the base wall of the sub-frame, and into the said screw receiving formation of the cavity closer profile.

7. An assembly as claimed in Claim 6, wherein after securement the screw head is at a part of the window or door frame profile, which, in the assembled window or door, is not seen.

8. An assembly as claimed in Claim 6 or 7, comprising means for determining the correct location of the wall or door frame profile on the cavity closer profile.

9. An assembly as claimed in Claim 8, wherein said means comprise an abutment formed on the cavity closer profile, on the side of the base wall opposite to the cavity closer, together with an indication on the cavity closer profile to show where screws should be inserted, for correct location in the screw-receiving formation of the cavity closer profile, when the wall or door frame profile is against the abutment.

10. An assembly as claimed in any of Claims 6 to 9, and which includes screws of size to extend to, but not through, the base of the screw-receiving formation.

11. A former, being a sub-frame comprising cavity closer profiles as claimed in any of Claims 1 to 5, about which the wall leaves may be built.

12. An assembly as claimed in any of Claims 6 to 10, comprising a sub-frame, having four sides, of which at least three comprise said cavity closer profiles; and a window or door frame, having four sides made up of said window or door frame profiles, secured to the sub-frame by screws engaged in the screw-receiving formations, without piercing of the said enclosed cores.

13. A method of fitting a window or door, using a cavity closer profile, assembly or former as claimed in any preceding claim.

14. A cavity closer profile, assembly, former or method substantially as hereinbefore described with reference to the accompanying drawings.