GB2574286A

GB2574286A - Corner joint and frame

Info

Publication number: GB2574286A
Application number: GB1900288.0A
Authority: GB
Inventors: Gregory Philip
Original assignee: Veka PLC
Current assignee: Veka PLC
Priority date: 2019-01-09
Filing date: 2019-01-09
Publication date: 2019-12-04
Anticipated expiration: 2039-01-09
Also published as: GB2574286B; GB201900288D0

Abstract

The hollow sections 12, 14 of the corner joint 10 comprise a front (24, figure 5a) and rear wall 28 coupled through an inner (30 figure 5a) and outer (32, figure 5b) wall, wherein the first profile section has a first end portion in which the inner and outer walls are cut off transversely leaving the front wall standing proud to form a front tongue 56 having a longitudinal edge 55. The second profile section has a second end portion which is cut of transversely such that the front wall is cut off inboard of the second end portion to form a transverse front edge 68 and either of the end portions comprise a rear wall which stands proud to form a rear tongue 58 having a longitudinal edge 59 with the other end section the rear wall is cut off to form a transverse rear edge 63. The corner joint further comprises a jointing piece receivable in the first and second profile sections to form the joint such that the front and rear tongues extend across the joint and the longitudinal and transverse edges of the front and rear walls adjoin one another.

Description

CORNER JOINT AND FRAME

The present invention is concerned with jointing of hollow profile sections, and is applicable especially in relation to windows.

Modern window sashes and frames are commonly constructed using hollow profile sections, which are typically plastics extrusions. Polyvinyl chloride (PVC) is a widely used material in this context. In a sash, four such profile sections need to be joined to one another in the required rectangular configuration. The necessary right angle joints may be formed using simple mitres, which gives the sash a modern appearance. However it is sometimes preferable, from an aesthetic point of view, to give the joint a different outward appearance. In a wooden frame, for example, mortise and tenon joints are commonly used. Outwardly, what one sees of a mortise and tenon joint is that one end of one frame member is cut off square (at right angles to its length) and abuts a long inner face of the adjacent frame member to form a right angle joint.

This appearance can be emulated using modern hollow profile sections. A suitable construction is disclosed in GB2430720B, which concerns a joint in which external faces of the profiles are cut square but an interconnecting matrixof the profiles is cut at 45 degrees to form an internal concealed mitre joint to be held together by plastics welding. The square and mitred cuts on the ends of each profile section can be formed by rotary cutting tools referred to in the trade as end mill cutters. But the combination of mitred and square cuts necessitates multiple machining stages for each end, which adds to the cost of sash manufacture.

Instead of - or indeed as well as - using plastics welding to secure joints together, it is known to provide an elbowed insert having two limbs at right angles to one another, one to be received in one profile section and one to be received in another. The insert can be a close interference fit in both profile sections. Examples of this type of joint are provided in EP2546450. In some cases the frame members described in this document have milled ends shaped to abut in a tessellating manner. In one such example the outer faces of the frame members have both mitred and square cut portions.

In accordance with the present invention there is a corner joint between first and second elongate hollow profile sections, wherein each profile section has a front wall and a rear wall coupled through an inner wall and an outer wall, and wherein:

the first profile section has a first end portion in which the inner wall and the outer walls are cut off transversely leaving the front wall standing proud to form a front tongue having a longitudinal front edge;

the second profile section has a second end portion which is cut off transversely and in which the front wall is cut off inboard of the second end portion to form a transverse front edge;

in either the first or the second end portion, the rear wall stands proud to form a rear tongue having a longitudinal rear edge, and in the other of the first and second end portions the rear wall is cut off to form a transverse rear edge;

the corner joint further comprising a jointing piece having first and second limbs angled to one another and receivable respectively in the first and second profile sections to form the joint, so that in the assembled joint:

the front tongue extends across the joint and the transverse front edge of the second end portion adjoins the longitudinal front edge of the front tongue;

the rear tongue extends at least part way across the joint and the transverse rear edge adjoins the longitudinal rear edge of the rear tongue.

Specific embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 shows the components of a corner joint embodying the present invention;

Figure 2a is a plan view of a window having a sash constructed using corner joints embodying the present invention and Figure 2b shows a cross section along the line A-A of Figure 2a, showing a profile section used in the corner joint along with an adjacent profile section forming a window frame, and certain related components;

Figures 3a and 3b are respectively plan and end views of a jointing piece of the corner joint;

Figures 4a, 4b and 4c show an end portion of a first frame member viewed along a direction transverse to its length. In Figure 4a an outer wall of the member faces toward the viewer; in Figure 4b a rear wall of the member faces toward the viewer; and in Figure 4c an inner wall of the member faces toward the viewer;

Figures 5a, 5b and 5c show an end portion of a second frame member viewed along a direction transverse to its length. In Figure 5a an outer wall of the member faces toward the viewer; in Figure 5b a rear wall of the member faces toward the viewer; and in Figure 5c an inner wall of the member faces toward the viewer; and

Figures 6a and 6b show the assembled corner joint viewed from the front side and from the rear side, respectively.

The illustrated corner joint 10 is part of a sash 2 for a flush sash window 4 (see Figure 2a), although it is equally well suited to use in sashes of other types, and in other types of frame requiring right angle joints or other corner joints between profile sections. The window 4 has a frame 6 which surrounds the sash 2 and is to be secured to a window reveal of a building.

The joint is formed between a first profile section 12 and a second profile section 14, which are identical to one another in cross section although they have different shapes machined onto their respective ends to form the joint. The joint is formed using a jointing piece 16 having first and second limbs 18, 20 which are mutually perpendicular. The first and second profile sections 12, 14 are slid onto the respective limbs of the jointing piece to form the joint.

The profile sections 12,14 are formed in the present embodiment as plastics extrusions. Unplasticised polyvinyl chloride is the chosen material in the present embodiment although other extrudable materials could be adopted.

Figure 2b shows the cross section of the profile sections 12,14, along with that of an adjacent window frame profile 8. The profile sections 12,14 have a front face 22 which is formed by a front wall 24 and which faces toward the exterior of a building when the sash is installed, and a rear face 26, formed by a rear wall 28, which faces the building's interior. The profile section 12, 14 can be thought of as an elongate hollow beam in which the front and rear walls 24, 28 are coupled through an inner wall 30 (which faces inwardly toward the window's glazing in use) and an outer wall 32 (which faces outwardly toward the surrounding window frame in use), although the inner and outer walls 30, 32 are not flat but are instead shaped to provide channels and other features.

Figure 2 shows that the front wall 24 stands proud inwardly of the adjacent inner wall 30 to form a glazing upstand 34 which is provided with a weather seal channel 36 for receiving a weather seal 36a and which has a chamfer 37 running along the inner edge of the front face 22. Running along the vertex between the inner wall 30 and the rear wall 28 is an inwardly facing glazing bead channel 39 for receiving a glazing bead 39a. In the assembled sash a glazing panel 38 is located between the weather seal 36a and the glazing bead 39a. A further portion of the front wall 24 stands proud outwardly of the outer wall 32 to form a peripheral upstand 40 having a peripheral channel 42 to receive a peripheral seal 42a which forms a seal between the sash and the surrounding frame, in the assembled window. A hardware mounting channel 44 is formed in the outer wall 32 to receive for example the hinge or slide mechanism that mounts the sash (not shown). The vertex between the rear wall 28 and the outer wall 32 is shaped to form a cove 46. Internal cavity 48 of the profile section 12, 14 is divided into three compartments by a pair of internal webs 50, 52. An internal metal stiffening member 53 is disposed in the internal cavity 48.

Figure 4 shows an end portion of the first profile section 12. Forming the end shape of the first profile section 12 can be carried out in two passes by suitable rotary cutters. Internal portions of the profile section forming the outer wall 32, inner wall 30, rear wall 28, glazing bead channel 39, hardware mounting channel 44 and webs 50, 52 have been cut such that their ends lie in a flat transverse plane 62 perpendicular to the length of the profile section 12. The end of the rear wall, lying in the plane 62, forms a transverse rear edge 63.The portion of the profile forming the cove 46 is left upstanding, forming a projection 64. At its free end the projection 64 is shaped at 66 to match the cross-sectional shape of the cove 46. The front wall 24 is cut away inboard of the plane 62, to form a transverse edge 68 whose profile is undercut to match the cross-sectional profile of the chamfer 37.

Referring now to Figure 5, the end shape of the second profile section 14 is able to be formed in a single pass of a suitably shaped rotary cutter. Internal portions of the profile section forming the outer wall 32, inner wall 30, hardware mounting channel 44 and webs 50, 52 are cut such that their ends lie in a flat plane 54 perpendicular to the length of the profile section 14. The front wall 24 is however left upstanding from the plane 54 to form a front tongue 56 having a front longitudinal edge 55 carrying in this example the chamfer 37. The rear wall 28, the cove 46 and the portions forming the glazing bead channel 30 have also been left proud to form a rear tongue 58 having a longitudinal rear edge 59. A portion 60 of the end of the rear tongue 58 is profiled to match the internal cross-sectional shape of the cove 46.

Jointing piece 16 is in the present embodiment a unitary plastics component and may be formed by injection moulding. Its first and second limbs 18, 20 are profiled to be slidingly received in the internal cavities 48 of the first and second profile section 12, 14 to form the joint. Referring to Figure 3, each limb 18, 20 is divided into three parts by slices 76, 77 which receive respective webs 50, 52 in the assembled joint. A locating channel 78 of the jointing piece 16 receives a shallow upstanding vane 80 formed on web 50 of the profile section 12, 14. A corner portion 71 of the jointing piece 16, which is exposed in the assembled joint as seen in Figure 6, is shaped to conform to the shape of the adjacent profile sections 12,14, and has on each of its limbs both the peripheral channel 42a and the hardware mounting channel 44a, as well as a face 82 that aligns with the adjacent outer face of the profile section 12, 14.

The two limbs of the jointing piece 16 are not identical, so that the jointing pieces must be provided in left and right handed forms. This is because the exposed corner portion 71 needs to meet and conform to the end shapes of the two profile sections 12,14, which are different.

In the assembled joint, the front tongue 56 of the first profile section 12 lies across the joint and over the jointing piece 16. The undercut transverse edge 68 of the first profile section 12 receives the longitudinal edge 55 of the front tongue 56 of the second profile section 14 so that the two mate closely and give the appearance of a butt joint. The rear tongue 58 of the second profile section 14 extends part way across the joint, its longitudinal rear edge 59 lying closely adjacent to the transverse rear edge 63 and its profiled end 60 receiving the cove portion of the projection 64 of the second 5 profile section 14 so that these parts mate closely and again give an appearance akin to that of a butt joint. The exposed corner portion 71 of the jointingpiece 70 gives a continuous shape to the surfaces of the sash facing toward the window frame. The result is a joint that has the desired appearance, is physically robust and is especially straightforward to assemble.

Claims

1. A corner joint between first and second elongate hollow profile sections, wherein each profile section has a front wall and a rear wall coupled through an inner wall and an outer wall, and wherein:

the first profile section has a first end portion in which the inner wall and the outer walls are cut off transversely leaving the front wall standing proud to form a front tongue having a longitudinal edge;

the front tongue extends across the joint and the transverse front edge of the second end portion adjoins the longitudinal edge of the front tongue;

the rear tongue extends at least part way across the joint and the transverse rear edge adjoins the longitudinal edge of the rear tongue.

2. A corner joint as claimed in claim 1 in which the first and second profile sections have at least substantially the same cross-sectional profile.

3. A corner joint as claimed in claim 1 or claim 2 in which the front wall stands proud of the inner wall to form a glazing upstand extending along the profile section.

4. A corner joint as claimed in any preceding claim in which the front wall stands proud of the outer wall to form a peripheral upstand extending along the profile section.

5. A corner joint as claimed in any preceding claim in which each profile section has a chamfer extending along the profile section and forming the longitudinal edge of the front tongue, the transverse front edge of the second end portion being undercut to receive the chamfered longitudinal edge of the front tongue.

6. A corner joint as claimed in any preceding claim in which a vertex between the rear wall and the outer wall of each profile section is in the form of a cove and the transverse rear edge is profiled to closely receive the cove.

7. A corner joint as claimed in any preceding claim in which a corner portion of the jointing piece is

5 exposed in the assembled joint, the corner portion having a profile which matches that of the adjacent portions of the first and second profile members.

8. A corner joint as claimed in any preceding claim in which each of the profile sections has an internal cavity divided by at least one internal web.

9. A corner joint as claimed in claim 8 in which the first and second limbs of the jointing piece both 10 have at least one slice to receive the internal web of the corresponding profile section.

10. A window comprising corner joints as claimed in any preceding claim.

11. A glazed sash comprising corner joints as claimed in any preceding claim.