GB2148963A

GB2148963A - Thermal insulation of aluminium extrusions

Info

Publication number: GB2148963A
Application number: GB08304320A
Authority: GB
Inventors: Roger Emsley
Original assignee: Individual
Current assignee: Individual
Priority date: 1983-02-16
Filing date: 1983-02-16
Publication date: 1985-06-05
Also published as: GB8304320D0

Abstract

This invention relates to a constructional means for the formation of a compound structural element in which two elongate outer portions 4 are interconnected throughout their length by a body of heat insulating material 2. This constructional means will normally comprise, two elongate outer portions 4 and two connecting webs 2 for holding the two outer portions in fixed spaced relation so as to form a hollow cavity within the constructional means. The connecting webs 2 may be of "Pultruded" glass reinforced Resin or Plastic. <IMAGE>

Description

SPECIFICATION Improvements in and relating to the thermally breaking of aluminium extrusions This invention relates to constructional means for the formation of a compound structural element in which two elongate buter portions are interconnected throughout their length by a body of heat insulating material.

Constructional means such as this are already being used in various industries such as the Building Industry for the manufacture of frame members for Doors, Windows, Facades etc. Unfortunately these current products suffer from the following problems: a) Insufficient resistance to heat transfer.

b) Deviation from dimensional tolerances.

c) Manufacturing difficulties in producing and surface finishing the many and varied profiles.

d) The structural limitations of the insulating materials used to connect the two elongate outer portions.

It is the object of this invention to overcome these aforementioned problems. By using a Glass Reinforced Resin or plastics, produced by the Pultrusion method, for the insulating element connecting the two outer elongate portions together, the thermal insulation, structural strength tolerance control and manufacturing methods can be greatly improved over current products.

Glass Reinforced Plastic or Resin (G.R.P.) because of its good mechanical properties combined with its good thermal insulating properties enables greater separation between aluminium (or steel) outer members, hence drastically reducing the condensation and heat loss problems.

Th Pultrusion process is comparable to the Extrusion process used to produce aluminium sections, the product raw material being pulled instead of pushed, both processes advantageously using the excellent angular and dimensional tolerance controlling features of a hardened metal die, so important for the products end usage.

The mechanical properties of G.R.P., in the main its resistance to high temperatures and chemicals, enable subsequent finishing such as painting to be carried out after the Thermal Breaking operation. Hence, reducing the number of handling operations, which inevitably cause damage and scrap.

The mechanical properties of G.R.P., mainly its compressive, shear and tensile strengths combined with its resistance to shock loads enables the product designer to use thinner, lighter sections, improving the cost and thermal performance figures.

The invention from this point is best described by way of example only with reference to the accompanying drawing in which: Figure 1 shows a cross section of a typical profile, in this case a vertical frame member for an Entrance Door, using two G.R.P. elements to connect the two extruded aluminium outer elements.

Figure 2 shows a cross section of a similar profile, using one G.R.P. element with a more conventional (except for the twin debridge) thermal break method.

N.B. Only one elevation is drawn because the length of section is variable and the profile is constant.

Referring first to Fig. 1, there is shown a typical hollow frame section. (in this case an Entrance Door Stile) Outer members 1 and 4 being identical profile aluminium extrusions.

Two connecting webs 2, completing the hollow box section elongate member.

The compound structural element in its final form, ready for subsequent machining to complete the component, in this case a Door stile is manufactured as follows: The two outer elements 1 and 4 are placed vertically in some form of jig to hold them in place, to receive the two webs 2, which can be slidably engaged either individually or simultaneously in to the mating grooves in the outer elements. Sufficient clearances, including standard manufacturing tolerances, is allowed between grooves 6, and mating lugs 7, to ensure a good, hand feed, self locating slide fit is possible.Once assembled, the complete loose fitting section can be fed through a series of rollers which both guide and control the accuracy of dimensional tolerances and bear down on the four elements 5, pressing and forming them onto the web Lugs 7, this forming operation results in the angled faces of the webs 2, and Lugs 7, nesting fully into the mating angled faces in the outer elements 1 and 4, eliminating all clearance gaps and in turn any movement in the 4 joints. The completed, section being a compound structural element suitable for manufacturing components from, such as Door and window framing.

Referring to Fig. 2, which again is a typical hollow frame section.

This time the G.R.P. web 2, is used in conjuction with a more conventional urethane resin filled thermal break 3, except for it having two strips of metal 6, machined away instead of one and the resin entry gap 7, being much wider. Both these changes being made to improve the overall thermal performance and make it compatible with the G.R.P.

web 2, opposing it.

The manufacturing procedure with the compound structural element shown in Fig. 2 is as follows: The main metal body of the section including the two outer elements 1 and 4 and metal joining web 8 is extruded in one piece as a U section A nozzle is then inserted through gap 9 prior to web 2, being fitted and dispenses liquid resin 3, into cavity 10, via the resin entry gap 7.

Once the resin 3, has cured and is hard, strips of metal 6, are removed. G.R.P. web 2, can then be slidably engaged in the same manner as described for Fig. 1 and elements 5, pressed and formed to trap web 2. The pressing of flanges 5 and removal of strips 6, can be carried out simultaneously if preferred, to save production time.

Claims

1) A constructional means from which a compound section structural element in which elongate outer portions are connected throughout their length by a body of heat insulating material, which constructional means comprises, two elongate outer portions and two connecting webs for holding the two outer portions in fixed spaced relation so as to form a hollow cavity within the constructional means.

2) A constructional means as claimed in claim 1) in which two glass reinforced plastics webs are, after slidable engagement between the two outer portions, held rigidly in position by pressing and forming protruding flanges on outer portions.

3) A constructional means as claimed in claim 1) in which one glass reinforced plastics web, secured as described in claim 2) is used in conjunction with a conventional but thermally improved resin filled thermal break.

4) A constructional means as claimed in claim 1) but using only one heat insulating element to connect the two outer portions.

5) Frame for a door or window comprising a contructural means as claimed in claims 1) 2) 3).

6) A constructural means constructed and arranged substantially as herein described with reference to and as illustrated in the accompanying drawing.