GB2201179A - Window assemblies - Google Patents

Abstract

The assembly comprises a window frame 10 and a main frame 11, each comprising respective structural plastics extrusions 20,21 which are clad with two aluminium extrusions 30 and 31 each of which has two longitudinally extending undercut channels 32 which slidably accommodate lengths of a plastics strip 33 having a divergent sides to retain the lengths of strip in the channels. The strips project through the mouths of the channels and are bonded to external surfaces of the extrusions 20 and 21. <IMAGE>

Description

WINDOW AND LIKE ASSEMBLIES This invention concerns improvements in or relating to window assemblies and like assemblies e.g. door assemblies, hereinafter referred to generally as assemblies.

There are known assemblies in which a door, window or like openable- or fixed member comprises a suitable, e.g. glass, panel surrounded and supported by a frame, hereinafter referred to as a window frame, and in which the window frame is fixedly, slidably or pivotally supported by a further frame, hereinafter referred to as a main frame. Such frames are usually formed primarily from a single material, such as wood, steel, aluminium or plastics.

Each material has well known inherent advantages and disadvantages. In the case of plastics materials the primary advantages are the ease of extruding suitable sections, ease of assembly, resistance to corrosion and deterioration, and overall cost; but such plastics extrusions are relatively soft and can be penetrated more easily than equivalent aluminium extrusions by cutting, sawing or the application of heat or solvents, and it is difficult to produce evenly and durably coloured frames by pigmenting the plastics material prior to extrusion, whereas aluminium extrusions can be provided quite easily with a ~ consistent and lasting colour finish. However, aluminium is more expensive, has a higher thermal conductivity and frames thereof are more costly to fabricate.

It is somewhat impractical and could be expensive to try to benefit from the advantages of both materials by constructing a frame from plastics interior structural extrusions and aluminium exterior structural extrusions, due to the greatly different co-efficients of thermal expansion which could give rise to distortion of the frame.

In general the invention proposes to clad a selected surface or surfaces of a frame, constructed primarily or substantially from plastics structural extrusions, with an aluminium cladding extrusion or extrusions, so that the cladding extrusions are permitted to move relative to the frame to an extent sufficient to accommodate the effects of common ambient temperature changes.

One possible way of mounting the cladding extrusions on the relevant structural plastics extrusions could be to provide formations in or on the latter which could be engaged by the cladding extrusions to allow the latter to be clipped or snap-fitted onto the frame.

However, this form of mounting would leave the cladding vulnerable to unauthorised removal, and would require special or additional plastics extrusions to be created or would require machining or other additional operations to be performed on the frame. A further object is therefore to enable such vulnerability and additional work to be avoided or reduced.

Accordingly the invention further proposes to provide at least one longitudinally extending undercut channel in a rear face of the or each cladding extrusion, to extrude a plastics strip of a divergent cross-section shaped to engage captively in and protrude from said channel, to slide a length of the strip longitudinally into the channel via one end thereof, and to bond the length of strip to said selected surface of the frame to secure the cladding extrusion to the frame.

In order to minimise corrosion, the cladding is preferably cut to size prior to being decoratively or protectively finished, so that the cut surfaces receive a finishing treatment, such as a resin or other protective coating.

The interengagement between the strip and opposing walls of the channel is preferably sufficient to resist a force of at least 12.5 kilogrammes on a centimetre length applied to the cladding in a direction to urge the strip through the mouth of the channel, whilst permitting substantially free sliding longitudinal movement between the channel and strip in the absence of any such applied force.

Even with such a strong interengagement between the cladding and the strip, it has been found that under certain circumstances the cladding may be forced from the frame during a severe frost.

A preferred embodiment of the interior provides an assembly comprising a window frame constructed primarily of or substantially from plastics extrusions, a panel supported by the frame, and aluminium cladding on at least a lower run of the frame, wherein an elastomeric seal is interposed between the panel and an abutment portion provided by the frame, wherein said seal overlies a junction between said abutment portion and a margin of the cladding and resiliently engages the latter to hinder ingress of water between the frame and cladding; and wherein said lower run is provided with an internal drainage path for exit of moisture entering the frame.

The assembly may include a main frame constructed primarily from plastics extrusions (with optional internal reinforcement e.g. by metal extrusions or pressings) and provided with aluminium cladding on selected surfaces, wherein along the or each bottom run of the main frame a junction between a margin of the cladding and an adjacent part of the main frame is protected or shielded against ingress of water by an elastomeric seal, or, orin addition thereto, by the junction being situated in a protective recess provided by the assembly; and wherein the or each bottom run is provided with an internal drainage path.

The invention will be described further, by way of example, with reference to the accompanying diagrammatic drawing showing, in part sectional perspective view, part of a lower run of an assembly of the invention.

The assembly comprises a window frame 10, a main frame 11, and a window panel 12, which may be of generally known construction, together with cladding and protective means as hereinafter described.

The frames 10 and 11 comprise respective structural plastics extrusions 20,21 which may be internally reinforced by metal members 22, and which have apertures 23 drilled therein to provide internal drainage paths 24.

The cladding comprises -two aluminium extrusions 30 and 31 each of which has two longitudinally extending undercut channels 32 which slidably accommodate lengths of a plastics strip 33 having a divergent sides to retain the lengths of strip in the channels. The strips project through the mouths of the channels and are bonded to external surfaces of the extrusions 20 and 21.

The protective means comprises, in combination with said paths, firstly an elastomeric seal 40 which is anchored in the extrusion 20 to be clamped between the panel 12 and an abutment part 25 of the extrusion 20, and which extends around a junction between the part 25 and an upper margin 34 of the extrusion 30; secondly a relatively confined recess 28 between the frames into which the upper margin 35 of the extrusion 31 extends to terminate at a concealed junction with an abutment part 26 of the extrusion 21; and optionally a further seal 41, anchored in said part 26, may extend to or beyond the latter junction.

During assembly, the frames are made; the cladding is cut to size; protectively coated therewith; the lengths of strip are cut and inserted, via the ends, into the channels; solvent or glue is applied to the strips and the cladding and strips are applied and secured to the frames; and thereafter the seals are secured in position.

The invention includes such a method of assembly, an assembly made by said method and methods and assemblies incorporating, or incorporating functional equivalents of, any novel step, part or feature disclosed herein; and the terms used herein, such as window and main frame, are by way of example only and are to be construed including functional or structural equivalents thereof, such as door and sub-frame.

Claims (12)

1. A door or window assembly comprising at least one frame formed from plastics structural extrusions, wherein a selected surface of the frame is clad with an aluminium cladding extrusion or extrusions, so that the cladding extrusions are permitted to move relative to the frame to an extent sufficient to accommodate the effects of common ambient temperature changes.

2. An assembly as claimed in Claim 1 wherein a rear face of the cladding extrusion is provided longitudinally with at least one undercut channel; and wherein a plastics strip of divergent cross section section is captively engaged in and protrudes from said channel and is bonded to said selected surface to secure the cladding extrusion to the frame.

3. An assembly as claimed in Claim 2 wherein the interengagement between the strip and opposing walls of the channel is sufficient to resist a force of at least 12.5 kilogrammes on a centimetre length applied to the cladding in a direction to urge the strip through the mouth of the channel, whilst permitting substantially free sliding longitudinal movement between the channel and strip in the absence of any such applied force.

4. An assembly as claimed in any preceding claim wherein along the or each bottom run of the frame a junction between a margin of the cladding and an adjacent part of the frame is protected or shielded against ingress of water; and wherein the or each bottom run is provided with an internal drainage path.

5. An assembly as claimed in Claim 4 wherein an elastomeric seal is provided at said junction.

6. An assembly comprising a window frame constructed primarily of or substantially from plastics extrusions, a panel supported by the frame, and aluminium cladding on at least a lower run of the frame, wherein an elastomeric seal is interposed between the panel and an abutment portion provided by the frame, wherein said seal overlies a junction between said abutment portion and a margin of the cladding and resiliently engages the latter to hinder ingress of water between the frame and cladding; and wherein said lower run is provided with an internal drainage path for exit of moisture entering the frame.

7. An assembly as claimed in Claim 4, 5 or 6 wherein said junction is situated in a protective recess provided by the assembly.

8. An assembly substantially as hereinbefore described with reference to the accompanying drawing.

9. A method of making an assembly as claimed in Claim 1 and including providing at least one longitudinally extending undercut channel in a rear face of the or each cladding extrusion, extruding a plastics strip of a divergent cross-section shaped to engage captively in and protrude- from said channel, sliding a length of the strip longitudinally into the channel via one end thereof, and bonding the length of strip to said selected surface of the frame to secure the cladding extrusion to the frame.

10. A method as claimed in Claim 9 wherein the cladding is cut to size prior to being decoratively or protectively finished, so that the cut surfaces receive a finishing. treatment.

11. A method of making a door or window assembly substantially as hereinbefore described with reference to the accompanying drawing.

12. A door or window assembly made by the method claimed in any one of Claims 9 to 11.