GB2294492A

GB2294492A - Mitred edge joint, with connector, for flanged window frame sections

Info

Publication number: GB2294492A
Application number: GB9520058A
Authority: GB
Inventors: John Edward Buckley
Original assignee: KWEST CORP Ltd
Current assignee: KWEST CORP Ltd
Priority date: 1994-10-25
Filing date: 1995-10-02
Publication date: 1996-05-01
Also published as: GB9421419D0; GB9520058D0

Abstract

A T-joint is provided between two extruded elongate profiled elements of a window frame or the like, each profiled element including an elongate hollow web 12, 17 along which extends hollow flanges 13, 14, 18, 20. The hollow flanges are cut and mitred to form the T-joint and L-shaped connectors 31 extend across each mitred joint and into the hollow flanges so as mechanically to connect the profiled elements together at the T-joint. <IMAGE>

Description

"Improvements in or relating to window frames or the like" The invention relates to window frames or the like comprising a generally rectangular frame formed from extruded elongate profile elements, for example of uPVC, and including one or more fixed cross-members, such as a horizontal transom, extending across the rectangular frame. A common form of such frame, for a window, comprises a single horizontal transom separating a larger, lower fixed glazed panel from a smaller, upper opening glazed vent. Although the invention will be particularly described in relation to window frames, it will be understood that the principle of the invention may also be employed in frames for other purposes, such as door frames.

In a window frame ofthis kind it is necessary to form a T-joint between each end of the transom, or other cross-member, and the peripheral frame member which it engages. Where the frame members are extruded from uPVC or other plastics material, the normal practice is to weld the ends of the cross-member to the frame members.

However, in practice, such welding is time consuming and the dimensional tolerances of the finished joint tend to be comparatively large, since the welding process necessarily involves melting and losing material at the junction between the two members. The present invention therefore sets out to provide an improved form of T-joint for use in such frames, and one where the speed of assembly and accuracy may be improved, when compared with conventional welded joints.

According to the invention there is provided a T-joint between two extruded elongate profiled elements of a window frame or the like, wherein each profiled element includes an elongate web along which extends at least one hollow elongate flange upstanding generally at right angles from the web, the end of the web of one element abutting a face of the web of the other element at a location intermediate the ends thereof, so that the flanges of the two elements lie in substantially the same plane, the end of said one element being secured to the face of the web of the other element by at least one mechanical fastening device, and the end of the flange of said one element being mitred to engage and register with a correspondingly mitred cut-away portion of the flange of said other element.

Preferably, a generally L-shaped connector is located within the mitred junction between the flanges, with the limbs of the connector extending in frictional engagement within the hollow interiors of the flanges respectively.

Each element may be formed with two spaced flanges, extending along opposite edges of the web, each flange on said one element forming a mitred junction with the corresponding flange on the other element, and being connected thereto by a respective L-shaped connector.

The, or each, flange on said other element may extend only part way along the web ofthe element to said location intermediate the ends thereof, said cut-away portion of the flange being removed from the end of the flange at that location.

In the case where each element is formed with two spaced flanges, the flanges on said one element may upstand in opposite directions from the web so that the element is generally Z-shaped in section, and the flanges on said other element may extend partway along the web from opposite ends thereof, ending adjacent the location, intermediate the ends of the element, where it is abutted by said one element.

In this case said other element may be formed in two parts comprising two similar extruded elongate profiled elements one of which is reversed and butt welded end-to-end to the other.

In an alternative arrangement, said one element is formed with two flanges extending in opposite directions from the same longitudinal edge of the web of the element, so that the element is generally T-shaped in section, the cut-away portion of the flange on said other element then being mitred on each side to engage and register with both said flanges on said one element, two L-shaped connectors being provided for engagement with the flange on said other element, on opposite sides of the cut-away portion, and within the two flanges on said one portion respectively.

The web of each elongate element may also be of hollow section.

Although the invention is particularly applicable to frame elements formed from plastics material, it will be appreciated that it may also be applied to extruded elements of metal, such as aluminium. In either case each L-shaped connector may be formed from metal or plastics material.

The aforesaid fastening device may comprise one or more screws passing transversely through the web of said other element and threadedly engaging within the end of said one element. Said one element may be formed with one or more longitudinal screw channels into the end of which such fastening screw may engage in self-tapping fashion. Each screw channel may be enclosed and is preferably of rectangular crosssection.

In another embodiment, the fastening screws may be arranged to engage a separately formed bracket, of metal or plastics, mounted on the end of said one element.

Alternatively, in the case where said one element comprises a hollow plastics profile containing a metal reinforcing member, the fastening screws may engage the reinforcing member. In either case the bracket or reinforcing member may be pre-threaded to receive the screws, or may be shaped to receive the screws in self-tapping fashion.

The invention includes within its scope a window frame or the like including one or more T-joints of any of the kinds referred to above.

The following is a more detailed description of an embodiment of the invention, by way of example, reference being made to the accompanying drawing which is an exploded perspective view of one form ofjoint in accordance with the invention.

The T-joint is between one of the side frame elements 10 of a rectangular window frame (the side element being shown horizontally in the drawing for convenience), and a horizontal transom 11 which extends between the sides of the frame and separates a lower fixed glazed panel (not shown) of the window from an upper hinged opening glazed vent. Both elements 10 and 11 are extruded elongate profiles of uPVC.

The transom 11 comprises a central hollow box section web 12 along opposite edges of which extend flanges 13 and 14 which upstand at right angles to the web 12 on opposite sides thereof, so that the element 11 is generally Z-shaped in section.

The reason for this shape is that the flange 13 which retains the fixed glazing panel requires to be on the outside of the window frame for security reasons and/or for ease of installation of the window into the building. This enables the removable securing strip (not shown) which retains the glazing panel against the flange 13 to be located on the inside of the window.

For the opening hinged vent, however, the flange 14 against which the vent abuts when closed requires to be on the inside of the window frame, so that the vent can open outwardly. The general construction of window frames from profiled elements is well known and will not be described in detail.

The side frame element 10 comprises two parts 15 and 16 butt welded together end-to-end. The part 15 comprises a hollow box section web 17 from one end of which upstands a flange 18. The part 16 is similarly formed with a hollow box section web 19 and an upstanding flange 20.

In order that the flanges 18 and 20 shall be in the correct position for registering with the flanges 14 and 13 respectively of the transom 11, the two elements 15 and 16 are reversed before being butt welded end-to-end so that each flange 18 and 20 extends only part way along the element 10 to the vicinity of the location of the end of the transom 11.

The flange 13 on the transom 11 is mitred at 45" as indicated at 21 and the corresponding flange 20 on the side frame element 11 is similarly mitred as indicated at 22. Short 450 mitres are also provided on the ends of smaller opposed flanges on each component as indicated at 23 and 24.

The flanges 14 and 18 are similarly mitred as indicated at 25 and 26 respectively.

The shaping of the end of the transom 11 and the flanges on the element 10 is such that the end of the transom fits neatly and closely between the flanges 18 and 20 with the end face 27 of the transom abutting the side face 28 of the webs 17 and 19.

The web 12 of the transom 11 is formed with longitudinal rectangular section screw channels 29 which register with holes 30 in the webs 17 and 19. The end ofthe transom is mechanically secured to the frame element 10 by self-tapping screws which extend through the webs 17 and 19 and holes 30 and into the screw channels 29.

In order to align the flanges ofthe transom 11 with the corresponding flanges of the element 10, and to provide additional strength and security to the joint, there are provided two generally L-shaped plastics connectors 31. Each connector has limbs 32 and 33. The limbs 32 of the connectors are received in the hollow ends of the flanges 13 and 14 respectively of the transom, and the limbs 33 are similarly received in the flanges 18 and 20 ofthe frame element 10. For the purposes of assembly the limbs 33 are first entered into the flanges 18 and 20 and this leaves the limbs 32 correctly aligned so that the end of the transom 11 may be pushed on to them. The limbs of the connectors 31 are a tight frictional fit within the respective flanges.

The invention thereby provides a mechanically secured joint which may be quickly assembled, when compared with the conventional welding process, and where the accuracy of the joint is determined solely by the tolerances in the manufacture of the components and is not affected by the process of forming the joint itself, as is the case with welding.

In some forms of window frame where the two glazed panels are both fixed or opening, the flanges on the transom may require to extend in opposite directions from the same edge ofthe web, so that the transom is substantially T-shaped in cross sect ion.

In this case the frame side element can simply be L-shaped in section, having a single upstanding flange extending continuously along the whole of its length. The frame element does not then require to be formed in two parts reversed and butt welded together. The joint is then formed and assembled in generally similar fashion to that described above but in this case the ends of the flanges on the transom will be mitred to fit in a substantially flat-bottomed V-shaped notch cut in the single continuous flange on the side frame element.

The profiles of the elements shown in the drawings are strictly by way of example and it will be appreciated that the invention may be applied to profile sections of many other shapes. For example, in small window frames there may be insufficient spring to assemble the T-joint using L-shaped connectors where the arms of the L are of equal length. In such cases one arm of the L-shape may be considerably shorter than the other. The shorter arm may be generally triangular in shape, having its edge nearer the other arm extending at right angles thereto, while its opposite edge is inclined, e.g.

at 45".

Claims

1. A T-joint between two extruded elongate profiled elements of a window frame or the like, wherein each profiled element includes an elongate web along which extends at least one hollow elongate flange upstanding generally at right angles from the web, the end of the web of one element abutting a face of the web of the other element at a location intermediate the ends thereof, so that the flanges of the two elements lie in substantially the same plane, the end of said one element being secured to the face of the web of the other element by at least one mechanical fastening device, and the end of the flange of said one element being mitred to engage and register with a correspondingly mitred cut-away portion of the flange of said other element.

2. A T-joint according to Claim 1, wherein a generally L-shaped connector is located within the mitred section between the flanges, with the limbs of the connector extending in frictional engagement within the hollow interiors of the flanges respectively.

3. A joint according to Claim 2, wherein each element is formed with two spaced flanges, extending along opposite edges of the web, each flange on said one element forming a mitred junction with the corresponding flange on the other element, and being connected thereto by a respective L-shaped connector.

4. A T-joint according to Claim 3, wherein the, or each, flange on said other element extends only part-way along the web of the element to said location intermediate the ends thereof, said cut-away portion of the flange being removed from the end of the flange at that location.

5. A T-joint according to Claim 3 or Claim 4, wherein the flanges on said one element upstand in opposite directions from the web so that the element is generally Zshaped in section, and the flanges on said other element extend part-way along the web from opposite ends thereof, ending adjacent the location, intermediate the ends of the element, where it is abutted by said one element.

6. A T-joint according to Claim 5, wherein said other element is formed in two parts comprising two similar extruded elongate profiled elements one of which is reversed and butt welded end-to-end to the other.

7. A T-joint according to Claim 5, wherein said one element is formed with two flanges extending in opposite directions from the same longitudinal edge of the web of the element, so that the element is generally T-shaped in section, the cut-away portion of the flange on said other element then being mitred on each side to engage and register with both said flanges on said one element, two L-shaped connectors being provided for engagement with the flange on aid other element, on opposite sides of the cut-away portion, and within the two flanges on said one portion respectively.

8. A T-joint according to any of the preceding claims, wherein the web of each elongate element is of hollow section.

9. A T-joint according to any of the preceding claims, wherein the aforesaid fastening device comprises one or more screws passing transversely through the web of said other element and threadedly engaging within the end of said one element.

10. A T-joint according to Claim 9, wherein said one element is formed with one or more longitudinal screw channels into the end ofwhich such fastening screw may engage in self-tapping fashion.

11. A T-joint according to Claim 10, wherein each screw channel is enclosed and is of rectangular cross-section.

12. A T-joint according to Claim 9, wherein the fastening screws are arranged to engage a separately formed bracket, of metal or plastics, mounted on the end of said one element.

13. A T-joint according to Claim 9, wherein said one element comprises a hollow plastics profile containing a metal reinforcing member, and said fastening screws engage the reinforcing member.

14. A joint according to Claim 12 or Claim 13, wherein the bracket or reinforcing member is pre-threaded to receive the screws, or is shaped to receive the screws in selftapping fashion.

15. A T-joint between two extruded elongate profiled elements, substantially as hereinbefore described with reference to the accompanying drawings.

16. A window frame or the like including one or more T-joints according to any of the preceding claims.