GB2272266A

GB2272266A - Joints connecting together hollow frame members

Info

Publication number: GB2272266A
Application number: GB9322019A
Authority: GB
Inventors: Richard James Heath
Original assignee: BESFORD HOLDINGS Ltd
Current assignee: BESFORD HOLDINGS Ltd
Priority date: 1992-10-30
Filing date: 1993-10-26
Publication date: 1994-05-11
Also published as: GB9222836D0; GB9322019D0

Abstract

A butt joint 2 connecting a vertical stile 3 to a horizontal rail 4 of a window or door 1 includes an interposed plastics spacer 16 having a body 21 which is located in a longitudinal groove 9 of the stile 3 and which has a projecting tongue 22 that is located in a longitudinal groove 9 of the rail 4 to provide a positive location for the end of rail 4 and prevent the rail 4 twisting relative to the stile 3. A tensioning bolt 17 anchored within the stile 3 extends through the spacer 16 and engages a tension block 15 secured by screws in the end of the rail 4, and the spacer 16 has flanges 23 on each side of the body 21 which separate the inner side edge of the stile 3 and the abutting end of the rail 4 on tightening the bolt 17 to spread the load and prevent deformation of the rail 4 and stile 3. Each flange 23 has an enlarged lip 32 which conceals the end of the rail 4 and gives the assembled joint a neat appearance. The grooves 9 in the stile 3 and rail 4 define a glazing channel. <IMAGE>

Description

IMPROVEMENTS IN OR RELATING TO JOINTS FOR CONNECTING TOGETHER HOLLOW FRAME MEMBERS This invention concerns improvements in or relating to joints for connecting together hollow frame members and in particular, though not exclusively, joints for connecting hollow frame members forming a door or window frame.

It is already known to form door and window frames from hollow frame members of substantially uniform section connected at the corners by mitre or butt joints. The frame members may be extrusions of metal, alloy, plastics or composites thereof.

In general, butt joints are preferred to mitre joints as being simpler to fabricate using frame members cut to length from an extrusion of the appropriate section by a simple transverse parting operation without requiring any special adaptation of the profile.

A common type of known butt joint employs a threaded bolt extending transversely through a first frame member to engage a fixing block or plate received within the hollow section of a second frame member extending normally to the first frame member to clamp the frame members together on tightening the bolt to draw the abutting end of the second frame member tightly against the first frame member.

A problem with such known butt joints is that twisting of the frame members may result in loosening of the joint making the assembled frame unstable. Tightening the bolt to increase rigidity may cause the abutting faces of the frame members to deform leading to distortion of the frame so that it no longer fits properly and, in the case of glazed frames, the glazing may break as a result of such distortion.

Another problem with such known butt joints is that inaccurate cutting of the frame members may prevent the frame members abutting properly against each other leaving gaps which detract from the aesthetic appearance of the assembled frame and allow water to penetrate into the hollow interior of the assembled frame where it may cause failure of any internal fittings such as espagnolettes.

Doors and window frames constructed from plastics frame members can be especially susceptible to the above problems and it has therefore been common practice to construct such frames with welded mitre joints.

The machinery for cutting and welding the frame members is expensive and the welded joints can be unsightly.

The present invention has been made from a consideration of the above-mentioned problems and has for its object the provision of a butt joint connecting hollow frame members for use in the construction of frames for doors, windows and the like which has a neat appearance with reduced tendency for deformation of the frame members so as to be suitable for hollow frame members of plastics as well as metal and alloy.

According to the present invention we provide a butt joint connecting hollow frame members for use in the construction of frames for doors, windows and the like, the butt joint comprising fastening means extending transversely of a first hollow frame member and engaging fixing means received within the section of a second hollow frame member extending normally to the first frame member to connect the frame members together with spacer means between the end of the second frame member and the first frame member.

By this invention, the spacer means gives the joint a neat appearance on the outside faces of the assembled frame members and spreads the load applied to the frame members on tightening the fastening means so as to reduce any tendency for the frame member to deform.

Preferably, the spacer means is adapted to conceal the joint on the outside faces of the frame members. In this way, any gaps caused by inaccurate cutting of the frame members are hidden improving the appearance of the joint and enhancing the resistance of the joint to water penetration.

Advantageously, the spacer means comprises a body received within the hollow section of the first frame member and having respective flanges extending from opposite sides between the end of the second frame member and the first frame member.

Preferably, the first frame member has a longitudinal groove on the inner side edge in which the body of the spacer means is received with the flanges seating against the outer free end of the groove sidewalls.

Advantageously, the outer free edge of each flange is formed with a bead or lip that overlies front and rear walls of the frame members to conceal the joint.

Preferably, the body has a formation received within the hollow section of the second frame member to provide a positive location for the abutting end of the second frame member.

Conveniently, the second frame member has a longitudinal groove on the inner side edge in which the locating formation is received with the longitudinal grooves of the first and second frame members define a glazing channel for the marginal edge of glazing.

Advantageously, the locating formation comprises a tongue at one end of the body and the flanges extend from said one end to separate 4he frame members over the entire length of the joint and provide clearance for glazing received in the glazing channel.

Conveniently, the fastening means comprises a threaded bolt anchored within the hollow section of the first frame member, and the fixing means comprises a block having a tapped bore engaged by the threaded bolt to connect the first and second frame members together.

Preferably, the block is a loose fit within the hollow section of the second frame member and is secured by retainer means extending transversely of the second frame member. For example, the retainer means may comprise one or more grub screws.

Other features, benefits and advantages of the invention will be apparent from the following description of an exemplary embodiment with reference to the accompanying drawings wherein: FIGURE 1 is an exploded perspective view showing the component parts of a corner butt joint in a door frame embodying the invention; FIGURE 2 is a scrap perspective view showing the assembled corner joint; FIGURE 3 is a section on the line 3-3 of Figure 2; FIGURE 4 is a section on the line 4-4 of Figure 2; and FIGURES 5a.b,c are front, side and plan views respectively of the spacer of the butt joint shown in Figures 1 to 4.

With reference to the drawings, one corner of a glazed rectangular door 1 is shown depicting a butt joint 2 between two frame members being a vertical stile 3 and a horizontal rail 4 respectively. In known manner, the door 1 has a pair of stiles 3 on opposed sides connected by a pair of rails 4 at the top and bottom with butt joints 2 similar to that shown at each corner.

The door 1 may include additional frame members (not shown) extending between and connected to the stiles 3 and/or rails 4 by butt joints 2 similar to that shown to produce different door styles.

The stile 3 is of uniform section with front and rear walls 5 and 6 respectively connected by recessed inner and outer side walls 7 and 8 respectively defining channel-section grooves 9 and 10 respectively extending lengthwise of the inner and outer sides of the style 3 and a central box-section void 11. The rail 4 is of uniform section similar to the stile 3, although this is not essential, and like reference numerals are used to indicate corresponding parts.

The stile 3 and rail 4 are each cut to the required length for assembly of the door 1 from a common extrusion of PVCu internally reinforced with an extruded aluminium or galvanised rolled steel member 12 of box-section extending lengthwise of the central void 11. The internal reinforcement is not essential and in certain applications may be dispensed with.

In the assembled door 1, the inner grooves 9 of the stiles 3 and rails 4 define a continuous glazing channel for the marginal edge of a double glazing unit 13 that is sealed by a glazing gasket 14 of soft rubber or like elastomeric material fitted around the perimeter of the glazing unit 13 prior to assembly.

The butt joint 2 connecting the stile 3 and rail 4 in the assembled door I comprises a tension block 15 that is secured within the end of the rail 4, a plastics spacer 16 that is located between the abutting end of the rail 4 and the inner side edge of the stile 3, and a tensioning bolt 17 that extends transversely through the stile 3 and spacer 16 to engage a tapped bore 18 in the block 15.

The tension block 15 is a clearance fit within the reinforcing member 12 and is secured by a pair of hexagon grub screws 19 inserted through the inner and outer side walls 7 and 8 respectively of the rail 4 and the reinforcing member 12. In this way, the block 15 can float within the end of the rail 4 to facilitate alignment of a threaded shank 20 of the bolt 17 with the tapped bore 18.

The spacer 16 comprises a rectangular body 21 which locates in the groove 9 on the inner side edge of the stile 3 and has a tongue 22 at one end which locates in the bottom of the groove 9 on the inner side edge of the rail 4. The body 21 and tongue 22 are a close fit between the side walls 7,8 of the stile 3 and rail 4 so as to provide a strong positive location for the abutting end of the rail 4 which prevents the rail 4 twisting in relation to the stile 3.

The body 21 further has a pair of flanges 23 on opposite sides that seat against the inner side edges of the front and rear walls 5 and 6 respectively of the stile 3. As a result, the abutting end of the rail 4 is separated from the inner side edge of the stile 3.

The bolt shank 20 extends through oversize aligned holes 24,25 and 26 in the reinforcing member 12, inner side wall 7 of the stile 4 and the body 21 of the spacer 16 respectively to engage the tapped bore 18 in the block 15.

The bolt 17 has a head 27 that is anchored within the central void 11 of the stile 4 by a washer 28 located over the shank 20 seating on the reinforcing member 12.

Aligned clearance holes 29 and 30 in the outer side wall 8 of the stile 4 and the reinforcing member 12 respectively allow passage of the bolt 17 for assembly and insertion of a suitable tool such as an allen key to engage a complementary recess 31 in the bolt head 26 for tightening the bolt 17 to connect the rail 4 and stile 3 and draw the end of the rail 4 tightly against the flanges 23 of the spacer 16 on the side remote from the inner side edge of the stile 3. In this way, the end of the rail 4 is prevented from contacting directly the inner side edge of the stile 3 and the flanges 23 spread the load applied on tightening the bolt 17 to prevent deformation of the stile 3 and rail 4.

The flanges 23 are longer than the body 21 and project from one end to provide clearance for the marginal edge of the glazing unit 13 received in the groove 9 of the rail 4 whilst separating the end of the rail 4 and the inner edge of the stile 3 over the entire length of the joint 2.

Each flange 23 has an enlarged lip 32 extending lengthwise at the outer free edge of the flange which overlies the front and rear walls 5 and 6 respectively of the stile 3 and rail 4 to assist in locating the cut end of the rail 4 and provide a neat finish to the joint 2 by concealing the cut end of the rail 4.

Additionally, any gaps between the rail 4 and stile 3 due to inaccurate cutting of the rail 4 are hidden preventing water penetration to the hollow interior of the assembled door 1. In this way, deterioration of internal fittings such as espagnolettes is prevented.

As will be appreciated, the present invention provides a butt joint for connecting hollow frame members having a neat appearance that resists deformation of the frame members and water penetration by provision of the spacer separating the frame members.

The invented butt joint has particular application for connecting hollow frame members made of plastics by enabling an acceptable joint to be obtained without the use of complex and expensive machinery commonly used to cut and weld mitre joints between hollow plastics frame members.

It will be understood, however, that the invented butt joints has application for connecting hollow frame members made of other materials such as metal or alloy which may have a protective coating of plastics, paint or other suitable finish applied thereto.

It will also be appreciated that the invented butt joint may be used to connect hollow frame members for constructing door, window and the like frames and that the opening inner frame andlor the surrounding outer frame may be constructed from hollow frame members using the invented butt joints.

It will further be understood that the invented butt joint has application for connecting hollow frame members having cross-sections different to that depicted and that it is not essential for frame members connected by the butt joint to be of the same cross-section. For example, one of the side walls defining the glazing channel may be provided by an internal or external glazing bead.

Claims

Claims:

1. A butt joint connecting hollow frame members for use in the construction of frames for doors, windows and the like, the butt joint comprising fastening means extending transversely of a first hollow frame member and engaging fixing means received within the section of a second hollow frame member extending normally to the first frame member to connect the frame members together with spacer means between the end of the second frame member and the first frame member.

2. A butt joint according to Claim 1 wherein the spacer means is arranged to spread the load applied to the frame members on tightening the fastening means so as to reduce any tendency for the frame member to deform.

3. A butt joint according to Claim 1 or Claim 2 wherein the spacer means is adapted to conceal the joint on the outside faces of the frame members.

4. A butt joint according to any one of the preceding Claims wherein the spacer means comprises a body received within the hollow section of the first frame member and having a respective flange on each side positioned between the end of the second frame member and the first frame member.

5. A butt joint according to Claim 4 wherein the first frame member has a longitudinal groove on the inner side edge in which the body is received with the flanges seating against the outer free end of the groove sidewalls.

6. A butt joint according to Claim 4 or Claim 5 wherein the outer free edge of each flange is formed with a bead or lip that overlies front and rear walls of the frame members to conceal the joint.

7. A butt joint according to any one of Claims 4 to 6 wherein the body has a locating formation received within the hollow section of the second frame member.

8. A butt joint according to Claim 7 wherein the second frame member has a longitudinal groove on the inner side edge in which the locating formation is received.

9. A butt joint according to Claim 8 wherein the longitudinal grooves of the first and second frame members define a glazing channel for the marginal edge of glazing.

10. A butt joint according to Claim 9 wherein the locating formation comprises a tongue at one end of the body and the flanges extend from said one end to separate the frame members over the entire length of the joint and provide clearance for glazing received in the glazing channel.

11. A butt joint according to any one of the preceding Claims wherein the fastening means comprises a threaded bolt anchored within the hollow section of the first frame member, and the fixing means comprises a block having a tapped bore engaged by the threaded bolt to connect the first and second frame members together.

12. A butt joint according to Claim 11 wherein the block is a loose fit within the hollow section of the second frame member and is secured by retainer means extending transversely of the second frame member.

13. A butt joint according to Claim 12 wherein the retainer means comprises one or more grub screws.

14. A butt joint according to any one of Claims 11 to 13 wherein the spacer means has a clearance hole aligned with the tapped bore for passage of the bolt.

15. A butt joint according to any one of the preceding Claims wherein the spacer means is made of plastics.

16. A butt joint connecting hollow frame members for use in the construction of frames for doors, windows and the like substantially as hereinbefore described with reference to the accompanying drawings.

17. A door or window constructed from elongate frame members connected by a butt joint according to any one of the preceding Claims.

18. A door or window according to Claim 17 comprising a rectangular frame with a butt joint connecting adjacent stile and rail members at each corner of the frame.