GB2398336A

GB2398336A - Composite window

Info

Publication number: GB2398336A
Application number: GB0403187A
Authority: GB
Inventors: David Robert Franklin
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-02-17
Filing date: 2004-02-13
Publication date: 2004-08-18
Anticipated expiration: 2024-02-13
Also published as: GB0303588D0; GB0403187D0; GB2398336B

Abstract

A composite window comprises an exterior frame 7 at least partially formed of metal and an interior frame 6 at least partially formed of timber. The interior frame comprises receiving means 1 adapted to receive a portion of the exterior frame and which is adapted to prevent moisture from contacting the interior frame. The receiving means may be in the form of a plastic clip that enables for the exterior frame to be attached to the interior frame using a snap fit arrangement. The receiving means may be attached to the interior frame by way of foam backed adhesive or lugs which comprise barbs.

Description

Composite Window The present invention relates to composite windows.

People often express an aesthetic preference for timber windows. Timber on the interior of a window is often desirable because the occupant of a room can appreciate a wood finish. However, wood exteriors suffer from the disadvantage that they are attacked by the weather and therefore require careful maintenance.

Utilising a composite window may obviate disadvantages associated with windows having a timber exterior. Such windows may have an interior frame and fittings (i.e. those parts of the interior window that appeals to the eye) made of timber but have an exterior portion made of a material that requires minimal maintenance.

UPVC is often used as an exterior finish but is considered by some to lack aesthetic appeal. An alternative to UPVC is the use of a metallic (e. g. aluminium) exterior.

Metallic exteriors are considered by many to be more appealing than UPVC and window manufacturers therefore seek to design composite windows with metallic exteriors and a timber interior.

One problem associated with composite windows, having a metallic exterior and a timber interior, is the development of condensation on metallic surfaces. Metals are conductive and as such their temperature may vary depending upon the environmental temperature. Furthermore metals on an external surface are exposed to a greater range of temperatures (depending on the season and the weather).

Accordingly, the temperature of the metal will change and may contrast with the ambient temperature (whether externally or within the composite window). This phenomenon can result in water condensing on the metal. This condensation represents a particular problem where the metal components of the window frame contact the wooden components of the window. This is because water condensed on the metal comes into contact with the wood and, over time, results in the timber rotting and thereby reducing the life span of the composite window.

Another problem associated with composite windows, having a metallic exterior and a timber interior, is that no matter how good the seal between the frame and the glass, there tends to be a problem of water ingress from the exterior into the interior of the window frame. Many windows are designed with drainage holes to allow the water to be removed. However, with or without such drainage holes there is a danger of water collecting against the wooden interior and thereby also causing it to rot.

It is an object of the present invention to obviate the abovementioned disadvantages as well as other disadvantages associated with the design of prior art composite windows.

Accordingly, the invention provides a composite window with at least part of an exterior frame formed of metal and at least part of an interior frame formed of timber wherein the interior frame is adapted to receive a portion of the exterior frame characterized in that the interior frame has receiving means for the portion of the exterior frame which is adapted to prevent moisture from contacting the interior frame formed of timber.

According to the present invention there is provided a composite window comprising an exterior frame and an interior frame, at least part of the exterior frame being formed of metal and at least part of the interior frame being formed of timber, wherein the interior frame comprises receiving means adapted to receive a portion of the exterior frame, and which receiving means is adapted to prevent moisture from contacting the interior frame formed of timber.

The inventor recognised that prior art composite windows had the disadvantage that timber in such windows was exposed to condensation and/or water leaking in from the external environment. He therefore developed composite windows according to the present invention to provide a unique way of attaching the timber sections to metal sections whilst at the same time not compromising thermal efficiency and providing a barrier against moisture from the glazing area to the timber . . . surface. ; The inventor found that the composite windows of the present invention last longer (the wood is protected from rot) and also provide considerable insulation to meet recent guidelines on energy efficiency for windows and doors (known to those operating in the British window industry as Document L).

Preferably, the receiving means is adapted to releasably engage with the portion of the exterior frame. It is preferred that the receiving means comprises a clip or the like formed of a thermal plastic or similar. The receiving means may be extruded. Preferably, the receiving means is ideally formed such that a portion of the exterior frame will "snap-fit" therewith, and thereby form a timber-metal composite.

Alternatively, the portion of the exterior frame may be slid along from one side of the receiving means forming a timber-metal composite. Preferably, the receiving means is substantially resilient to enable it to snap-fit with the exterior frame.

The receiving means may comprise a rear or back portion, which is preferably substantially planar, and which is preferably, adapted to be attached to the interior frame. Preferably, the interior frame is formed of timber. The receiving means, and preferably, the back portion thereof, may be connected to the interior frame by suitable fixing means, for example, by means of adhesive (e.g. a glue or adhesive tap), or a screw. Preferably, the receiving means is connected to the interior frame by compressible adhesive means. This adhesive is preferably thermally insulating and/or may be elastic. Foam-backed adhesive is highly suitable in this respect. This is because it gives some flexibility to the joint between the metal and timber and thereby allows for easier construction and fitting of window units. This elasticity also makes it easier to affix the receiving means to the surface of the timber - which may not be an entirely even surface. Furthermore, the compressibility facilitates the snap-fitting of the portion of the exterior frame onto the receiving means as will be described hereinafter.

Alternatively, or additionally, the receiving means may be attached to the interior frame by a system comprising a lug adapted to be inserted into a channel. The receiving means may comprise a lug, which extends substantially transversely away from the back portion thereof, preferably towards the interior frame. The interior frame may comprise a channel, which extends away from the receiving means and, which is preferably substantially parallel with the lug. Preferably, the channel in the interior frame is suitably sized to accommodate the lug of the receiving means.

Preferably, the lug comprises at least one barb, a distal end of which points towards the back portion of the receiving means. Preferably, the lug comprises a plurality of barbs. Preferably, the barbs are arranged around the circumference of the lug, and preferably extend radially outwardly therefrom. Advantageously, the backwardly pointing barb(s) help the insertion of the lug in to the channel, but are arranged such that the lug does not easily exit the channel. In addition, the lug may be maintained in position in the channel by adhesive, for example, polyurethane glue.

Preferably, the receiving means comprises a space or gap adjacent a base of the lug, which base is positioned where the lug is attached to the back portion. For example, where foam-backed adhesive is used to attach the receiving means to the interior frame, the foam-backed adhesive does not extend all the way up to the base of the lug. Advantageously, the gap provides space in to which adhesive can fill and expand as it solidifies, as the lug is inserted in to the channel and fixed therein.

Preferably, the receiving means comprises first and second arms, which arms extend substantially transversely away from the back portion, preferably towards the portion of the exterior frame. Preferably, when in use, the first arm forms an upper arm and preferably, the second arm forms a lower arm. Preferably, the back portion extends beyond the position of the first arm thereby forming an overlap region.

Preferably, in use, the overlap region is adapted to abut against the interior frame.

Advantageously, the overlap region helps to prevent condensation from rising up over the receiving means and contacting the timber portion of the interior frame.

Preferably, the portion of the exterior frame, which is adapted to engage with the receiving means, is substantially the same width as the distance between the first and second arms of the receiving means. The portion of the exterior frame may be slid from one side along the receiving means, preferably in between the two arms, or snap fitted therebetween. This results in the attachment of the exterior frame to the interior frame. Preferably, the first and second arms are semi-rigid, i.e. they are rigid enough to maintain the portion of the exterior frame in position, but are adapted to flex, so that they can be prised apart as the exterior frame is pushed therebetween. In addition, the compressibility of the foam- backed adhesive allows the back portion of the receiving means to flex, thereby allowing the portion of the exterior frame to urge the first and second arms apart.

Preferably, the distance between the two ends of the arms distal from the back portion is less than the distance between the two ends of the arms proximal to the back portion. Preferably, the ends of each arm distal from the back portion extend towards each other, preferably, for a short distance, and are adapted to prevent the portion of the exterior frame from detaching from the receiving means.

Advantageously, and preferably, the receiving means is adapted to drain moisture therealong, thereby minimising contact with the timber interior frame.

Moisture may drain along the lower arm of the receiving means, preferably on an upper face thereof. Moisture may drain along the junction of the receiving means and the exterior frame.

The exterior frame may be partially or entirely made from a number of different metals or alloys thereof. It will be appreciated that Aluminium (which is commonly used in window units because it is light) represents a preferred metal used for the exterior frame of composite windows according to the invention.

The timber forming the interior frame will be dictated by taste and may be formed of any suitable wood used for making window frames (softwood [e. g. pine] or hardwood [e.g. seasoned oak or the like]).

According to a preferred embodiment of the invention the composite window comprises further insulation that may be fitted between the glass and timber surfaces and may also be fitted into any cavities within the frame. Such insulation (which may be an insulating foam or similar) further reduces the risk of wooden surfaces being exposed to condensation or invasive water.

The invention will be further described by way of example only with reference to the accompanying drawings in which: Figure I is a transverse section through a first embodiment of a composite window according to the invention; and Figure 2 is a transverse section through a second embodiment of a composite window according to the invention.

Referring to Figure 1, there is shown a first embodiment of a composite window (20), which comprises an exterior frame (7) formed from a length of aluminium. It will be appreciated that the exterior frame (7) may be of varying lengths and styles to make up window frames for use as direct replacement windows or use in conservatory walls. An interior frame (6) is formed of timber and may also be of varying shapes and thickness.

A receiving means (1) comprising a thermal plastic or similar is affixed to the interior frame (6) by means of adhesive, adhesive tape or adhesive backed foam (3).

The receiving means (1) consists of a rear or back plate (34) and two arms (la, lb) each with end (38), which arms (la,lb) extend transversely away from the back plate (34). When in use, one arm forms an upper arm (la), and one arm forms a lower arm (lb). The back plate (34) extends upwardly away from the upper arm (la) to form an upper region (36), which abuts against the interior frame (6). During assembly of the composite window (20), the receiving means (1) is secured to the interior frame (6) by a screw (2), before the exterior frame (7) is connected to the interior frame (6).

It will be seen from Figure 1 that the receiving means (1) attaches a substantially horizontal portion (40) of the exterior frame (7) to the interior frame (6).

The width of the horizontal portion (40) of the exterior frame (7) is approximately the same as the distance between the two arms (la,lb) ofthe receiving means (1). Hence, sliding the horizontal portion (40) of the frame (7) from one side of the receiving means (1), or snap-fitting it directly in between the two arms (la,lb) of the receiving means (1), results in attachment thereto, and hence of the exterior frame (7) to the interior frame (6). The arms (la,lb) are semi-rigid, but the compressibility of the foam (3) allows the back plate (34) to flex, thereby allowing the horizontal portion (40) to urge the arms (la,lb) sufficiently apart so that it can snap-fit therebetween.

The ends (38) of each arm (la,lb) extend partially towards each other to prevent the horizontal portion (40) of the frame (7) from detaching from the receiving means (1).

When attached, the receiving means (1) forms a barrier to prevent moisture [condensing on the aluminium exterior frame (7)] from contacting the timber surface (6) of the interior frame (6). The receiving means (1) acts as a surface along which moisture may drain away from the timber interior frame (6). The receiving means (1) also prevents water penetrating from the outside entering the cavity (8) and contacting the timber interior frame (6). The upper region (36) of the back plate (34) acts as a barrier to prevent moisture from seeping upwards along the interior frame (6). Extra thermal insulation and glazing security is gained by use of double sided tape or foam (4) between the glazing unit (9) and the interior frame (6). The void (5) disposed to the distal side of the substantially horizontal portion of the exterior frame (7) may be filled with foam or similar (5) to provide extra insulation.

Referring to Figure 2, there is shown a second embodiment of a composite window (40), in which identical reference numerals are used to represent similar features as those shown in Figure 1 in the first embodiment (20). In the second embodiment (40), the receiving means (1) is attached to the interior frame (6) by compressible adhesive backed foam (3), and, in addition, by means of a lug (22), which extends transversely away from the back plate (34) of the receiving means (1), and which lug (22) is inserted into a channel (24) cut into the interior frame (6). The channel (24) is suitably sized to fully accommodate the lug (22). The lug (22) has a series of barbs (30) extending radially therefrom, the ends of which point rearwardly towards the back plate (34) of the receiving means (1). This is so that that insertion of the lug (22) into the channel (24) is easy, whereas the barbs (30) prevent the lug (22) from coming out of the channel (24). In addition, the lug (22) is maintained inside the channel (24) by adhesive (not shown), for example, polyurethane glue.

The adhesive backed foam (3) is attached along the majority of the back plate (34) of the receiving means (1), but does not extend all the way to the base of the lug (22), thereby leaving gaps or spaces (32) either side thereof. The gaps (32) are present to provide space in to which adhesive can expand and solidify, as the lug (22) is inserted and fixed in position in the channel (24).

Advantages of the embodiments of the composite window (20,40) reside in the manner in which a metallic (e.g. aluminium) external frame (7) may be attached to a non-metallic (e.g. timber) window frame (6), whereby condensation is prevented from coming into contact with the timber, which would otherwise cause rotting. The upper region (36) provides an effective barrier against rising condensation, which would otherwise come into contact with upper portions of the interior frame (6). In addition, the invention provides an effective method of compensating for expansion and contraction of the different portions of the window frame (6,7), due to variations in temperature. This is achieved by the compressibility of the adhesive backed foam (3).

Furthermore, the compressible foam (3) provides flexibility when the horizontal portion (40) is snap-fitted in between the arms (la,lb) of the receiving means (1).

Furthermore, the barbed lug (22) and channel (24) for attaching the receiving means (1) to the interior frame (6) is very easy to use, cheap and effective. Moreover, the spaces (32) either side of the lug (22) provide room in which expanding glue in the channel (24) may be squeezed.

Claims

A composite window comprising an exterior frame and an interior frame, at least part of the exterior frame being formed of metal and at least part of the interior frame being formed of timber, wherein the interior frame comprises receiving means adapted to receive a portion of the exterior frame, and which receiving means is adapted to prevent moisture from contacting the interior frame formed of timber.
2. A composite window according to claim 1, wherein the receiving means comprises a clip or the like formed of a thermal plastic or similar.
3. A composite window according to either claim I or claim 2, wherein the receiving means is ideally formed such that a portion of the exterior frame will "snap-fit" therewith, and thereby form a timber-metal composite.
4. A composite window according to any preceding claim, wherein the receiving means comprises a rear or back portion, which is adapted to be attached to the interior frame.
5. A composite window according to any preceding claim, wherein the receiving means is adapted to be connected to the interior frame by suitable fixing means.
6. A composite window according to any preceding claim, wherein the receiving means is connected to the interior frame by compressible adhesive means.
7. A composite window according to any preceding claim, wherein the receiving means is connected to the interior frame by foam-backed adhesive.
8. A composite window according to any preceding claim, wherein the receiving means comprises a lug, which extends substantially transversely away from a back portion thereof.
9. A composite window according to any preceding claim, wherein the interior frame comprises a channel, which extends away from the receiving means.
10. A composite window according to either claim 8 or claim 9, wherein the lug comprises at least one barb, a distal end of which points towards the back portion of the receiving means.
11. A composite window according to any of claims 8-10, wherein the lug comprises a plurality of barbs.
12. A composite window according to claim 11, wherein the barbs are arranged around the circumference of the lug, and extend radially outwardly therefrom.
13. A composite window according to any of claims 8-12, wherein the receiving means comprises a space or gap adjacent a base of the lug, which base is positioned where the lug is attached to the back portion.
14. A composite window according to any of claims 4-13, wherein the receiving means comprises first and second arms, which arms extend substantially transversely away from the back portion.
15. A composite window according to claim 14, wherein, in use, the first arm forms an upper arm and the second arm forms a lower arm.
16. A composite window according to either claim 14 or claim IS, wherein the back portion extends beyond the position of the first arm thereby forming an overlap region.
17. A composite window according to claim 16, wherein in use, the overlap region is adapted to abut against the interior frame.
18. A composite window according to any of claims 14-17, wherein the portion of the exterior frame, which is adapted to engage with the receiving means, is substantially the same width as the distance between the first and second arms of the receiving means.
19. A composite window according to any of claims 14-18, wherein the portion of the exterior frame may be slid from one side along the receiving means in between the two arms, or snap fitted therebetween.
20. A composite window according to any of claims 14-19, wherein the distance between the two ends of the arms distal from the back portion is less than the distance between the two ends of the arms proximal to the back portion.
21. A composite window according to any of claims 14-20, wherein the ends of each arm distal from the back portion extend towards each other for a short distance, and are adapted to prevent the portion of the exterior frame from detaching from the receiving means.
22. A composite window according to any preceding claim, wherein the composite window comprises insulation fitted between the glass and timber surfaces and may also be fitted into any cavities within the frame.
23. A composite window substantially as herein described with reference to, and as illustrated by, the accompanying drawings.