GB2140855A

GB2140855A - Insulated door or window frame

Info

Publication number: GB2140855A
Application number: GB08413956A
Authority: GB
Inventors: Derek Ronald Lancaster
Original assignee: RTZ Extruders Ltd
Current assignee: RTZ Extruders Ltd
Priority date: 1983-06-02
Filing date: 1984-05-31
Publication date: 1984-12-05
Also published as: GB2140855B; GB8413956D0

Abstract

A method of making the frame in which two frame elements 2, 4 are supported in aligned spaced relationship for example by means of an insert member 6. The mutually facing sides of the elements 2, 4 have between their edges opposed support formations 16 to support bridging members such as tape strips 18. The channels so defined are suquentially flied with a curable synthetic resin and the insert member 6 may be subsequently withdrawn. <IMAGE>

Description

SPECIFICATION Method of making a thermally insulating frame member This invention relates to a method of making a thermally insulating frame member for a door or window.

It is known to produce a thermally insulating frame member from an integral aluminium extrusion by providing a thermal break in the thermally conductive webs which extend between the inner and outer surfaces of the frame. Each such web is formed with a channel portion, the base of which is cut away, covered and then filled with a synthetic resin material. When this has cured the other web may be cut and filled in the same way.

A disadvantage of the known method is that since internal stresses are normally present in hollow extrusions, the debridging step may produce an undesirable deformation or distortion of the frame member. Certain forms of extrusion are particularly prone to this defect and considerable wastage may result. A further disadvantage is that relatively complex extrusions are generally needed.

Accordingly a method of making a thermally insulating frame member is provided as claimed in Claim 1 hereof.

The invention as claimed has numerous advantages. The need for de-bridging is obviated, while the risk of distortion is much reduced since any internal stress in the frame elements is not released. In addition the frame elements are simpler than a corresponding integral extrusion and are easier to produce.

In particular, the production of heavy thermally insulated elements, such as large rails, is facilitated. Moreover, the two part frame construction lends itself more readily to prior surface finishing by anodising or film coating processes.

Accurate alignment and spacing of the frame elements may be obtained by means of a jig, but for speed and simplicity it is advantageous to use an elongate spacing member, which maybe removeable, and is provided with a plurality of locating formations each of which is adapted to cooperate with a complimentary formation formed on each of the frame elements. A spacing member of thermally insulating material, may be left in situ, with the advantage that air ciculation between the frame elements may be reduced.

The support formations which are provided along the longitudinal edge portions of the frame elements may be in any form suitable for retaining the opposed longitudinal edges of the bridging member. Preferably the formations are elongate ribs disposed and arranged so that only a narrow gap is formed between opposedly directed ribs. With this arrangement it is advantageous to use a bridging member in the form of a tape adhesively bonded between each pair of opposed ribs.

The bridging members may serve to retain each frame element in abutment with the spacing member, which supports the frame elements in the required relative positions.

The bridging members may be sufficiently rigid to support the two elongate frame members in aligned spaced relationship, to enable the spacing member to be withdrawn prior to filling the channels with the synthetic resin material. This method facilitates the removal of the spacing member which may otherwise become clamped between the frame elements, and thus difficult to remove, due to a possible contraction of the synthetic resin material during curing or hardening.

The invention as claimed also facilitates the production of frame members of hybrid construction, that is, one having a metal element on one side, and a plastics element on the other, which are preferred for certain applications.

One embodiment will now be described by way of example only with reference to the accompanying drawings, in which Figures 1, 2 and 3 are cross-sectional drawings of a large door rail in different stages of production.

Referring to Fig. 1, two elongate frame elements 2, 4 of extruded aluminium are supported in aligned spaced relationship by means of a removeable elongate spacing member (6) of H shape cross section. The mutually facing sides 8, 10 of the elements 2, 4 are integrally formed with V shaped nibs 12 which locate in cooperating V shaped grooves 14 formed in the insert member 6. The included angle of grooves 14 is greater than the included angle of the nibs 12 to facilitate withdrawal of the spacing member as described below. The frame elements are located in accurate register by these means.

Each of the mutually facing sides 8, 10 has a support formation in the form of an elongate rib 16 disposed inwardly from the longitudinal edges 17.

As may be seen in Fig. 2, bridging members in the form of adhesive backed plastics tape 18 are retained by adhesive bonding between opposed pairs or ribs 16 to form the base of channel sections 20 defined between longitudinal edge portions of the elements 2, 4. The tape 18 was an expanded, closed cell crosslinked polyethylene material.

The adhesive tape 18 retains the elements 2, 4 against the insert member 6, although ancilliary clamping may be provided as necessary.

The assembly is then turned edge up and synthetic resin material 22 (Fig. 3) is added to each channel in turn. When the resin has cured, insert 6 is slidably removed from the hollow section.

In an alternative method, the plastics tape 18 is selected to have sufficient rigidity to support the frame elements 2 and 4 in aligned spaced relationship, and the spacing member 6 is withdrawn before the synthetic resin material 22 is added to the channels 20.

Claims

1. A method of making a thermally insulating frame member, for a door or window, in which two elongate frame elements are supported in aligned spaced relationship, the mutually facing sides of the elements each having a support formation disposed inwardly from the longitudinal edges thereof, the opposed formations defining a longitudinal gap therebetween, a bridging member in the form of a strip of plastics material being retained by opposed support formations to bridge each gap so as to form a base portion of an outwardly opening channel defined between longitudinal edge portions of the elements, and filling each channel with a curable synthetic resin material.

2. A method as claimed in Claim 1 wherein the frame elements are spaced apart by an elongate spacing member provided with a plurality of locating formations each of which is adapted to cooperate with a complimentary formation provided on each of the frame elements, the bridging members retaining each frame element in abutment with the spacing member.

3. A method as claimed in Claim 2 wherein the bridging members are sufficiently rigid to support the two elongate frame members in aligned spaced relationship, and the spacing member is withdrawn prior to the filling of the channels with the synthetic resin material.

4. A method as claimed in Claim 2 or 3 wherein the spacing member is withdrawn after the synthetic resin material has cured in the channels.

5. A method as claimed in Claim 2 in which the spacing member is made from a thermally insulating material which is left in situ after the synthetic resin material has cured in the channels.

6. A method as claimed in any preceding Claim wherein the bridging member is a tape strip adhesively bonded between opposed support formations.

7. A method of making a thermally insulating frame member for a door or window substantially as described with reference to the accompanying drawings.