GB2318143A - Window frame element of hollow plastic construction, filled with a pourable reinforcing material preferably concrete, and can be reinforced by steel bars. - Google Patents

Abstract

A load bearing frame element suitable for the construction of an outer window frame for new or replacement windows, comprising a hollow extrusion 1 of plastics material preferably uPVC, having one or more internal compartments within the element, characterised in that at least one of the compartments is substantially filled with a pourable reinforcing material 3 preferably concrete, such that the compartment(s) become suitable for load-bearing. The frame elements can be reinforced with reinforcing bars 4 held in place by spacers. The reinforcing material can be poured into the element after it has been constructed or injected during the extrusion process. The plastic extrusion when used as a cill, may comprise a window ledge 2 with a hollow compartment between the window ledge and the rest of the cill, forming a cold bridge.

Description

Outer Frame Element Field of Invention This invention relates to load-bearing outer frame elements particularly for use as outer window frames and cills.

Background to the invention The manufacture and sale of replacement windows has become a major industry over the last decade.

It has become almost the norm to replace single giazed wooden and metal windows, commonly fitted to most of the housing stock in the UK, with aluminium or uPVC double glazed units.

uPVC offers many advantages in respect of cost, durability and ease of working but it nevertheless has disadvantages. One of these relates to uPVC's poor load bearing qualities. For example, where it is necessary to replace a bay window or any window which previously had load-bearing capacity special precautions must be taken. This is possible although fitting time and costs are increased. One further problem, is that once the new units are fitted it is not easy to check whether the installation has been carried out correctly.

Previous attempts to make outer frame elements from materials such as metal and plastic load-bearing have only been partly successful. For example, metal or plastics type outer frame elements reinforced with wood internally have been problematic because the wood tends to rot. Moisture can enter the frame, for example, through the joints or during the manufacturing process and cause the wood to rot over time and thus weaken the frame. Moisture may also be present in the wood before it is inserted into the element. In order to reduce the likelihood that the wood will rot, treated wood or hard wood can be used. However, this puts up the manufacturing costs and even so does not completely remove the problem of rotting.

Another problem is that outer window frames or cills may not be straight.

For example those used for bay windows must extend around the bay. This means that if the outer frame element is to be reinforced using a solid material the process of fitting this reinforcing material into the element is complex. This makes the reinforced frame time consuming and expensive to manufacture.

Further problems with known metal or plastics type outer frame elements occur during the fitting process. When fitters are putting in new outer frame elements they are typically under pressures of time and cost and may take shortcuts in the fitting process. For example, in the fitting of outer window frame elements such as window cills to bay windows, bay poles are typically used to support the load above the window. These bay poles extend vertically between the window cill and the top of the window. The bay poles should be fitted through holes drilled into the cill. However, to save time and costs fitters may simply rest the bay poles on top of the cill. If the cill is not load-bearing the weight of the structure above the window may be too great and eventually this structure may sink or collapse.

It is accordingly an object of the present invention to provide a reinforced outer frame element that is capable of load-bearing particularly for use as a window cill which overcomes or at least mitigates one or more of the problems noted above.

Summary of invention According to the present invention, there is provided an outer frame element suitable for the construction of an outer window frame for new or replacement windows, comprising an outer wall enclosing one or more internal compartments within the element characterised in that at least one of the compartments is substantially filled with a pourable reinforcing material such that in use the filled compartment(s) becomes load-bearing. This has the advantage that a load bearing outer frame element can be provided by a manufacturer so that no short cuts can be taken during the fitting process that are likely to result in structural damage to the building in which the window is being replaced. Also, the use of a pourable material, such as one that later hardens, gives the advantage that a substantial part of even complex-shaped frame elements can be filled with the material quickly and easily.

In a preferred embodiment the reinforcing material is comprised of concrete.

As the concrete hardens it shrinks slightly within the outer wall of the frame element.

This means that the outer wall has some "give" or possibility for movement against the concrete. This makes the outer wall less likely to crack or break.

In a further preferred embodiment the reinforcing material is further comprised of fine aggregate, cement, sand and granite chippings. This improves the reinforcing qualities of the material and provides durability.

Advantageously the invention includes an outer frame element adapted for use as a window cill wherein the outer frame element further comprises a ledge running substantially along the length of said outer frame element and adapted to provide a window ledge.

In a preferred embodiment of the invention the outer frame element is made from uPVC.

Description of the drawings The invention will be further described, by way of example, with reference to the accompanying drawings in which: Figure 1 shows a cross section through a reinforced window cill according to the present invention; Figure 2 is a cross section through a reinforced window cill that contains reinforcing rods.

Figure 3 shows a cross section through another embodiment of a reinforced window cill.

Figure 4 shows a cross section through another embodiment of a reinforced window cill.

Figure 5 shows a cross section through another embodiment of a reinforced window cill.

Figure 6 shows a schematic cross section through a bay window.

Figure 7 shows a schematic cross section through a typical spacer.

Figure 8 shows a schematic elevation of a window with an outer frame and a cill.

Figure 9 shows a cross section through an upright outer window frame element.

Description of preferred embodiments Embodiments of the present invention are described below by way of example only.

These examples represent the best ways of putting the invention into practice that are currently known to the Applicant although they are not the only ways in which this could be achieved.

Outer window frame elements according to the present invention can be used for outer window frames, doorlwindow cills or for any other similar openings in a building or other structure. The term outer window frame is used to describe the frame that is attached to the building or other structure and the term cill is used to describe the support element provided under, for example a window or door which also comprises a ledge such as a window ledge.

Figure 1 shows an example of a box sectioned cill according to the present invention. In this example, the element is adapted for use as a window cill and has a ledge 2, in this case a window ledge (although the element would also function without this ledge). In this example, the window cill comprises an outer wall 13 surrounding the frame element and four compartments 14. One of the compartments 3 is substantially filled with reinforcing material as indicated by the textured pattem in Figure 1. This compartment 3 has a cross-sectional area large enough so that the volume of material contained in it is sufficient to give this compartment the necessary load-bearing capability. In use the load bearing compartment of the window cill 3 is positioned substantially under the window and rests on the surrounding brickwork or other structure.

The reinforcing material is pourable so that it can be easily inserted into the element. For example, concrete, aggregate, sand or mixtures of these and similar materials can be used. This has the advantage that the reinforcing material can quickly and easily be added to the element thus reducing manufacturing time and costs. Also, pourable material enters the element easily and reaches substantially the whole of the interior of the compartment 3. The term pourable material in this context is intended to include materials that can be provided in a pourable form but which can also exist in a solid form after for example, a cooling, hardening or solidifying process takes place. An example, of such a material is concrete. The term concrete is meant to include any cement based product which will set hard to give the necessary load bearing properties. Also materials which can be injected into the element or added during the extrusion process are included as well as particulate materials such as aggregate which can be dropped or poured into the compartment 3. In a preferred embodiment of the invention the reinforcing material comprises concrete incorporating fine granite chippings. The use of concrete mixtures has been found to be particularly advantageous because these mixtures shrink slightly as they set or harden. This means that there is some give or flexibility between the outer wall of the element and the reinforcing material. This tends to make the outer wall of the element less likely to crack or break.

The cross sectional area of the compartment 3 may be varied as indicated in Figures 1, 3, 4 and 5. The cross sectional area is typically increased relative to that found in known outer window frame element extrusions. In this way the volume of reinforcing material can be adjusted to meet particular load-bearing needs. The amount of reinforcing material used and thus the cost and weight of the product can be balanced.

A compartment 15 may also be provided to prevent the formation of a cold bridge between the window ledge part of the cill 2 and the rest of the cill. As shown in figures 3 to 5 the compartment 15 provides a void between the compartment 3 and the rest of the element. The compartment 15 may contain air or other insulating materials. It provides insulation to reduce the transfer of heat between the outside and inside of the window.

Many possible shapes for the cross section of the compartment 3 can be used. Figures 1 and 3 show two examples although many others are possible. By adapting the shape of the compartment 3 the element can be adapted to fit existing fittings or supports on the building or other structure. Similarly, provisions can be made in the shape of the compartment 3 for attaching other items to the element.

As shown in Figure 2 reinforcing rods 4 may be provided in the compartment 3 together with the reinforcing material. During the manufacturing process, spacers 6 can be used to hold the rods 4 in place. One or more spacers are inserted into the compartment 3 of the element at various points along its length. The spacers are held between the sides of the element and may be made from metal, plastics material or any other material that is strong enough to hold the rods. For example, the spacers can be made of steel or plastic and typically uPVC or spring steel are used so that the spacers can be resiliently biased against the walls of the compartment 3. The rods 4 are clipped into holders 7 in the spacers and are held in position as shown in Figure 2. The reinforcing material can then be poured into the compartment 3 around the rods 4. Because the reinforcing material is pourable it filters through the spacers and around the rods 4 filling the compartment 3. The pourable material is then allowed to settle, set or harden if necessary. The rods 4 can be made of metal such as steel, although other materials can also be used.

The spacer shown in Figure 7 is just one possible example of a spacer shape. Other similar designs could be used.

The outer wall 13 of the window frame element can be made from metal or plastics material or other similar materials. In a preferred embodiment it is manufactured using an extrusion process using uPVC although this is not essential.

The present invention is particularly suited for use with bay windows.

Figure 6 shows a schematic cross section through a bay window cill. This cill is made up from several sections 8. Known methods of supporting structure above bay windows include the use of bay poles positioned vertically between the bottom of the cill and the structure above the window. The bay poles are typically positioned near the joins 9 between the sections 8 and may either rest against the cill or be inserted into the cill. As already described, it is important that the cill is load bearing so that it can support the bay poles, the window and the structure above the window.

Outer frame elements according to the present invention can be joined to form a sectioned window cill such as that shown in Figure 6. For example, during the manufacturing process outer frame elements that do not yet contain a pourable reinforcing material are cut to the desired length. (The elements may however contain reinforcing rods and spacers at this stage if desired.) These lengths are then joined together using any suitable means, for example welding or gluing, to form a sectioned cill similar to that shown in Figure 6. It will be appreciated that many different shapes of cill can be constructed in this way. One end of the frame is plugged for example, with a piece of foam or other material and then reinforcing material is poured into the window frame element. The pourable material flows through each of the sections around any bends such as those at the joints 9 in Figure 6. This has the advantage that a one-piece load bearing cill is produced which is able to support the bay poles even when these are positioned near the joints 9 in the cill.

Alternatively, outer frame elements that are already filled with reinforcing material may be joined together to form a cill or other structure similar to that shown in Figure 6. For example, foam plugs can be placed in the ends of the individual frame elements during the filling process so that regions are left at the ends of the frame where no reinforcing material is present. After the plugs are removed the frame elements may be joined end to end using these conventional methods.

During the manufacturing process when the pourable material is added to the frame element a vibration process can be used to ensure that the reinforcing material fills the whole of the desired region and that no spaces or voids form.

Several methods are possible. For example, the frame element once filled with the pourable material can be placed onto a vibrating table or surface and left to harden.

Alternatively, a portable vibrating unit can be placed next to the frame element.

Another method involves vibrating any reinforcing rods 4 that have been placed inside the element. It is also possible to use a vibrating head on the end of a wire.

This is placed inside the frame element before the pourable material is added. With the head at the bottom of the frame element pourable material is gradually added and the vibrating head slowly drawn up through the reinforcing material using the wire.

Figure 8 shows a schematic view of an outer frame element adapted for use as a window cill and an outer window frame 11. The present invention also encompasses vertical outer window frame elements 11 which are reinforced with pourable material. In the example shown in Figure 8, the vertical window frame element 11 may be filled with reinforcing material according to the invention and also, part of the horizontal section of this outer window frame element 12 can be reinforced in a similar way. If necessary the cross-sectional area of the outer window frame element can be increased to allow sufficient reinforcing material to be added. This has the advantage that the load-bearing capability of the outer window frame is further increased.

One advantage of the invention is that load-bearing outer frame elements can be provided by the manufacturer prior to fitting. This means that fitters cannot take short cuts when fitting the outer frame elements which would be likely to result in a frame element that was not load bearing.

Claims (6)

Claims

1. An outer frame element suitable for the construction of an outer window frame for new or replacement windows, comprising an outer wall surrounding the element and one or more internal compartments within the element characterised in that at least one of the compartments is substantially filled with a pourable reinforcing material such that in use the filled compartment(s) becomes loadbearing.

2. An outer frame element as in claim 1 wherein the reinforcing material is comprised of concrete.

3. An outer frame element as claimed in any preceding claim wherein the reinforcing material further comprises one or more reinforcing rods extending substantially entirely along the length of the element.

4. An outer frame element according to Claim 3 wherein the reinforcing rods are held in place within a compartment by one or more spacers.

5. An outer frame element as claimed in any preceding claim adapted for use as a window cill wherein the outer frame element further comprises a ledge running substantially along the length of said outer frame element and adapted to provide a window ledge.

6. An outer frame element as claimed in any preceding claim wherein the outer frame element is made from uPVC.