GB2488042A

GB2488042A - Window frame assembly

Info

Publication number: GB2488042A
Application number: GB201202287A
Authority: GB
Inventors: Daniel Andrew Gill
Original assignee: WINDOW WIDGETS LLP
Current assignee: WINDOW WIDGETS LLP
Priority date: 2011-02-09
Filing date: 2012-02-09
Publication date: 2012-08-15
Anticipated expiration: 2032-02-09
Also published as: GB201102207D0; GB201202287D0; GB2488042B

Abstract

AÂ window has a rectangular outer frame formed from hollow extruded components 51 connected at corners of the frame by butt joints, wherein the components 51 have a profile free from undercuts in the surfaces forming the butt joint. In this way a wet seal between the components 51 can be avoided. Preferably there is an outer frame with an opening with a rebate around its inner periphery for receiving an inner frame and having one or more sealing faces. The rebate is preferably a raised step 81 having first and second portions at right angles to each other which form the sealing faces for seals located on the inner frame. Reinforcements may be provided within the frame members. The frames members are preferably made from extruded plastics and connected via welding or mechanical joints. Also claimed is: a window with a inner and outer frames, the outer frame having a rebate with a raised step, and: a window with an outer and inner frames and at least one sealing member on the inner frame for mating with a rebate on the outer frame.

Description

IMPROVEMENTS IN OR RELATING TO WINDOWS

This invention concerns improvements in or relating to windows. The invention has particular application to windows made of plastics, especially plastics extrusions such as PYCu extrusions.

A typical window comprises a rectangular outer frame that in use is fixed and has at least one rectangular opening in which a rectangular glazed inner frame is mounted. The inner frame may be supported by hinges for opening movement or fixed. The number and arrangement of glazed inner frames may be chosen to provide different combinations according to the required window size and style as desired.

Typically, the frames comprise horizontal and vertical frame members that are cut to length from extrusions of the appropriate profile and assembled by mitring the ends and joining the mitred ends by welding at right angles.

While such mitred joints arc acceptable for installation in many areas, they are not generally acceptable for installation in conservations areas where windows arc required to resemble the appearance of traditional timber windows in which the frame members butt up against each other at right angles.

It is already known to shape the plastics extrusions used for the vertical frame members so that the horizontal and vertical frame members can be butted up against each other at right angles by end milling one of the members and then secured by welding or by a mechanical joint in order to resemble traditional timber windows. However, problems can arise with this method of assembly, particularly when constructing the outer frames due to the presence of undercuts that are difficult to seal when the frame members are butted up against each other and arc prone to leaking.

The present invention has been made from a consideration of the foregoing and seeks to provide a solution to the problems aforementioned.

In one aspect, the present invention eliminates or at least reduces the presence of undercuts in areas of the frame members that are to butt up against each other.

More especially a rectangular frame for a window is formed from hollow extruded components connected at corners of the frame by butt joints, wherein the components have a profile essentially free from undercuts in the surfaces forming the butt joint.

Undercuts may be reduced or eliminated, particularly in the components forming an outer frame of a window by avoiding the need for weather seals on the outer frame.

This may be achieved by providing the outer frame with a rebate that extends around the inner periphery of an opening in the outer frame for receiving an inner frame and providing one or more weather seals on the inner frame to contact and seal against the outer frame within the rebate.

The rebate may be provided with a raised step between first and second portions of the rebate that extend at an angle to each other, typically substantially at right angles.

The raised step may eliminate undercuts within the rebate between the first and second portions whereby the components of the outer frame can be butt joined by end milling one of the components to butt up against the other component at right angles so that areas requiring a wet seal may be avoided.

The components may comprise a body having a flange at one end to provide the rebate with the raised step being provided between the body and the flange. The height of the step is less than the height of the rebate and may be of the order of half the height of the rebate although it may be more or less than half the height of the rebate. The length of the step is less than the length of the rebate and may be of the order of one third the length of the rebate although it may be more or less than one third the length of the rebate.

The weather seal(s) on the inner frame may seal against the flange and or body within the rebate. Alternatively or additionally, the weather seal(s) on the inner frame may seal against the step within the rebate.

The components are preferably made of plastics and may conveniently be cut to length from an extrusion of uniform cross-section. The components may be joined by welding or by mechanical joints. The extrusion may be reinforced, for example by an internal reinforcement of metal or alloy extending lengthwise of the extrusion. The extrusion may contain multiple internal compartments that are separated from each other whereby the thermal characteristics of the frame may be improved to reduce heat transfer from one side of the frame to the other side. The step may provide an additional compartment that can enhance the thermal characteristics of the frame and contribute to a reduction in heat loss.

The inner frame may be fixed or supported for opening movement. Where the inner frame can open, opening movement may be outwards or inwards according to the configuration and installation of the window. The inner frame may be supported for hinging movement about a horizontal axis or a vertical axis or a combination thereof.

In another aspect, the present invention provides an extruded hollow profile of plastics material for assembly of a rectangular window frame wherein the profile has a longitudinally extending rebate that in use extends around an inner periphery of an opening in the frame wherein the rebate has a raised step.

In another aspect, the present invention provides a window comprising an outer frame defining an opening and an inner frame received in the opening, and at least one sealing member on the inner frame for providing a seal with the outer frame within a rebate extending around the inner periphery of the opening.

In another aspect, the present invention provides an outer frame for a window constructed from elongate hollow components to define a rectangular opening for an inner frame wherein each component has a rebate with a raised step.

In another aspect, the present invention provides a window comprising an outer frame defining an opening and an inner frame mounted in the opening, wherein the opening has a rebate extending around an inner periphery of the opening provided with a raised step between surfaces of the rebate that are arranged substantially perpendicular to each other.

The invention will now be described in more detail by way of example only with reference to the accompanying drawings wherein: Figure 1 is a vertical cross-section through part of the frame and sash of a

prior art window;

Figure 2 is a vertical cross-section through the frame of Figure 1 showing areas that are difficult to seal; Figure 3 is a vertical cross-section through part of the frame and sash of a window embodying the invention; Figure 4 is a perspective view of a joint between horizontal and vertical frame members of the frame shown in Figure 3; Figure 5 is an end view of the joint shown in Figure 4; Figure 6 shows a window with an outer frame and a horizontal transom; Figure 7 shows a window with an outer frame and a horizontal transom and a vertical mullion; Figure 8 is a cross-section through an internal frame member for the transom of Figure 6 or the mullion of Figure 7 and the sash of a window embodying the invention; Figure 9 shows a joint between the frame member of Figure 8 and the outer frame of the window in Figure 6 or Figure 7; and Figure 10 shows a joint between two of the frame members of Figure 8 in the window of Figure 7 Referring to the drawings, Figure 1 shows a vertical cross-section through part of a prior art window comprising a rectangular outer fixed frame defining a rectangular opening in which a rectangular glazed inner frame is mounted. The inner frame may be supported by hinges (not shown) for opening movement or may be fixed. The inner frame may be referred to as a sash frame. Each frame comprises horizontal rail members at the top and bottom and vertical stile members at the sides. The rail and stile members are cut to length from hollow extruded profiles of PVCu or other suitable plastics and joined at their ends.

The rail and stile members of the outer frame are cut to length from a hollow extruded profile 1 of generally L-shape in cross section comprising a rectangular body 3 and a rectangular flange S at one end of the body 3 to provide, in the assembled frame, a rebate 7 that extends around the inner periphery of the opening for the inner frame. The flange 5 is provided on the inside of the window when installed with the rebate 7 opening to the outside of the window.

The rail and stile members of the inner frame are cut to length from a hollow extruded profile 9 of generally T-shape in cross-section comprising a rectangular body 11 and a pair of rectangular flanges 13, 15 at one end of the body 11 to provide, in the assembled frame, an internal rebate 17 and an external rebate 19. The internal rebate 17 receives glazing (not shown) secured by an internal glazing bead (not shown) secured in a groove 21. A weather seal is provided between the glazing and the frame by a sealing gasket 23 attached to the flange 13. Weather seals are also provided between the frames by a pair of sealing gaskets 25, 27. One gasket 25 is attached to the flange 15 of the inner frame and engages the outer front wall of the outer frame, and the other gasket 27 is attached to the flange 5 of the outer frame and engages the inner rear wall of the inner frame.

In order to connect the rail and stile members at the corners of the outer frame to resemble a traditional timber window, the stile members can be end milled to a profile that allows the stile members to be butted up against the rail members at right angles. However, as shown in Figure 2, the rail member has areas 29a, 29b in the rebate 7 that provide undercuts in the extruded profile used for the components of the outer frame and prevent the stile members being end milled to provide a profile that exactly matches the profile of the rail members they are to be butted up against. As a resuh gaps are formed between the rail members and stile members when butted up against each other which require a wet seal that is prone to leaking.

Referring now to Figure 3, a vertical cross-section through part of a window according to the invention is shown comprising, like Figure 1, a rectangular outer fixed frame defining a rectangular opening in which a rectangular glazed inner frame is mounted. The inner frame may be supported by hinges (not shown) for opening movement or may be fixed. The inner frame may be referred to as a sash frame. Each frame comprises horizontal rail members at the top and bottom and vertical stile members at the sides. The rail and stile members are cut to length from hollow extruded profiles of PYCu or other suitable plastics and joined at their ends.

The rail and stile members of the outer frame are cut to length from a hollow extruded profile 51 of generally L-shape in cross section comprising a rectangular body 53 and a flange 55 at one end of the body 53 to provide, in the assembled frame, a rebate 57 that extends around the inner periphery of the opening for the inner frame. The flange 55 is provided on the inside of the window when installed with the rebate 57 opening to the outside of the window.

The rail and stile members of the inner frame are cut to length from a hollow extruded profile 59 of generally L-shape in cross-section comprising a rectangular body 61 and a flange 63 at one end of the body 61 to provide, in the assembled frame, an internal rebate 65. The internal rebate 65 receives glazing 67 secured by an internal glazing bead 69 secured in a groove 71.

The glazing may be of any type, for example single, double or triple glazing according to requirements. A weather seal is provided between the glazing 67 and the frame by a sealing gasket 73 attached to the flange 63 and between the glazing 67 and the bead 69 by a sealing gasket 75 attached to the glazing bead.

Weather seals are also provided between the frames by a pair of sealing gaskets 77 and 79 on the inner frame that engage the body 53 and flange 55 respectively within the rebate 57 of the outer frame. As shown, a raised step 81 is provided in the rebate 57 between the body 53 and the flange 55. As shown the step 81 has a first portion 81a and a second portion 81b. The first portion 81a extends away from the flange 55 and is inclined towards the body 53. In this embodiment the first portion 81a extends at an angle of approximately 15 degrees to the horizontal but it will be understood this is not limiting, for example the inclination of the first portion 81a may be greater than or less than 15 degrees to the horizontal. The second portion 81b extends away from the body 53 to meet the first portion 81a. In this embodiment the second portion 81b extends generally perpendicular to the body 53 but it will be understood this is not limiting, for example the second portion 8lb may be inclined towards the flange 55.

The gaskets 77, 79 are attached to the inner frame on the underside of the body 61 adjacent to the inner and outer edges of the inner frame. The gasket 77 engages the upper surface 53a of the body 53 adjacent to the outer edge of the rebate. As shown, the upper surface 53a is inclined to the horizontal providing a lead-in edge or ramp face that gradually increases compression of the gasket 77 as the inner frame is closed so as to ensure a weather tight seal in the closed position of the inner frame. Furthermore, this inclination avoids snagging of the gasket as the inner frame is opened. In this embodiment the upper surface 53a extends at an angle of approximately 15 degrees to the horizontal but it will be understood this is not limiting, for example the inclination of the upper surface 53a may be greater than or less than 15 degrees to the horizontal. The gasket 79 engages the front surface SSa of the flange 55 above the step 81. The surfaces 53a and 55a extend at an angle to one another. The gaskets 77, 79 may be made of rubber or elastomer or plastics. The gaskets 77, 79 may be formed separately from the extrusion 59 and may be secured in undercut grooves. Alternatively, the gaskets 77, 79 may be formed integrally with the extrusion 59 such as by co-extrusion. In a modification (not shown), one or both gaskets 77, 79 may be located to engage the step in the closed position of the inner frame. For example, the gasket 79 may be located on the inner frame to engage the upper surface of the step 81 and the inclination of the first portion 81a is such that the gasket is gradually compressed as the inner frame is closed to ensure a weathertight seal in the closed position of the inner frame. The gasket 77 may be located on the inner frame to engage the front surface of the step 81. The upper and front surfaces of the step 81 engaged by the gaskets extend at an angle to one another.

As will be appreciated, the arrangement in which both sealing gaskets 77, 79 are arranged on the inner frame to contact and seal against the outer frame within the rebate 57 of the outer frame eliminates undercuts in the rebate 57 of the outer frame. As a result, when the rail and stile members of the outer frame are assembled to resemble a traditional timber window, the stile members can be end milled to match the profile of the rail members. In this way the stile and rail members can be butted up against each other with no gaps between the surfaces forming the butt joint as shown in Figures 4 and S and secured by welding or by a mechanical joint. As a result, areas requiring a wet seal as in the prior art can be avoided. The rail and stile members may be locked relative to each by co-operating formations that engage when the members are butted up against each other. For example a shallow channel-section groove 83 may be provided in the body 53 of the rail member to receive a complementary formation on the stile member. The groove 83 does not have an undercut. Moreover, as the frames are sealed relative each other within the rebate, it is not necessary for the inner frame to overlap the outer frame on the outside of the window and the inner frame can be configured so that the outer surface is substantially flush with the outer surface of the outer frame as shown in Figure 3.

It will be understood that the invention is not limited to windows in which the outer frame has one opening for one inner frame. The outer frame may have a plurality of openings formed by internal frame members that extend between the rail members and/or the stile members and/or between each other and the term outer frame is to be construed accordingly. For example one or more horizontal transom members and/or vertical mullion members may be provided to provide openings of any desired size within the outer frame. Figure 6 shows a window with the outer frame of Figure 3 and a horizontal transom providing two openings within the outer frame, and Figure 7 shows a window with the outer frame of Figure 3 and a horizontal transom and a vertical mullion providing four openings within the outer frame. Other configurations of transoms and/or mullions are possible as will be familiar to those skilled in the art.

These internal frame members may likewise be formed without undercuts so as to allow butt joints to be formed by end milling as described previously.

Figure 8 shows one such profile for an internal frame member that can be cut to length from an extrusion 85 of generally T-shape with flanges 87, 89 at one end of a hollow rectangular body 91 to provide rebates 93, 95 on opposite sides of the body where the rebates 93, 95 are provided with raised steps 97, 99 similar to the step 81 of the outer frame members. Figure 9 shows the joint between the internal frame member and the outer frame in Figure 6 or Figure 7 and FigurelO shows the joint between two internal frame members in Figure 7.

It will be understood that the invention is not limited to the embodiments above-described. For example extrusions having other profiles may be employed for the frame members that allow the frame members to be joined as described without requiring a wet seal. Although we have described forming the joints by end milling the vertical stiles to butt up to the horizontal rails, it would be possible to end mill the horizontal rails to butt up to the vertical stiles. Furthermore, while we have described sealing between the frames within the rebate by two sealing gaskets on the inner frame, it will be understood that less than two, i.e. one sealing gasket, or more than two, i.e. three or more sealing gaskets may be employed.

A further feature of the invention is the provision of a large number of separate compartments or chambers within the cross-section of the profiles employed for assembly of the frames. The number and arrangement of these compartments or chambers can improve the thermal characteristics of the frame and reduce heat loss. The step provides an additional compartment that may enhance thermal characteristics of the frame and reduce heat loss.

For example as shown in Figure 3, the step extends below the inner frame in the closed position which may reduce heat loss compared to the arrangement shown in Figure 1. Thus, the step creates a pocket which improves the thermal performance (better insulated) of the frame. The step also provides a feature which datums positioning of hardware e.g. locks, fitted to the frame.

Other benefits and advantages of the invention will be apparent from the description herein and the invention extends to and includes any novel feature or novel combination of features disclosed whether explicitly or implicitly.

Claims

CLAIMS1. A rectangular window frame formed from hollow extruded components connected at corners of the frame by butt joints, wherein the components have a profile free from undercuts in the surfaces forming the butt joint.
2. The window frame of claim 1 wherein the frame is an outer frame and has an opening with a rebate that extends around an inner periphery of the opening for receiving an inner frame and is configured to provide one or more sealing faces for one or more seals on the inner frame.
3. The window frame of claim 2 wherein the rebate has first and second portions that extend substantially at right angles to each other.
4. The window frame of claim 3 wherein the first and/or second portions provide sealing faces for seals on the inner frame.
S The window frame of claim 2 wherein the rebate is provided with a raised step.
6. The window frame of claim S wherein the step has first and second portions that extend substantially at right angles to each other.
7. The window frame of claim 6 wherein the first and/or second portions provide sealing faces for seals on the inner frame.
8. The window frame of any of claims 2 to 7 wherein the components comprise a body having a flange at one end to provide the rebate.
9. The window frame of claim 8 as dependent on claims S to 7 wherein the raised step is provided between the body and the flange.
10. The window frame of any preceding claim wherein the components are made of plastics.
11. The window frame of claim 10 wherein the components are joined by welding or by mechanical joints.
12. The window frame of claim 10 or claim 11 wherein the components are reinforced.
13. The window frame of any of claims 10 to 12 wherein the components contain multiple internal compartments within the hollow profile that are separate from each other.
14. A window comprising the window frame according to any preceding claim.
15. The window of claim 14 wherein the window frame is an outer fixed frame defining an opening having a rebate extending around an inner periphery of the opening and the window further comprises an inner frame mounted in the opening wherein the inner frame is provided with one or more weather seals for sealing contact with the outer frame within the rebate.
16. A window comprising an outer frame defining an opening and an inner frame mounted in the opening, wherein the opening has a rebate extending around an inner periphery of the opening provided with a raised step between surfaces of the rebate that are arranged at an angle to each other.
17. A window comprising an outer frame defining an opening and an inner frame received in the opening, and at least one sealing member on the inner frame for providing a seal with the outer frame within a rebate extending around the inner periphery of the opening.
18. The window of any of claims 15 to 17 wherein the inner frame is fixed.
19. The window of any of claims 15 to 17 wherein the inner frame is supported for opening movement.
20. A rectangular window frame substantially as hereinbefore described with reference to Figures 3 to 10 of the accompanying drawings.