GB2091329A - Door or window frames - Google Patents

Abstract

A composite section door or window frame 1 comprising at least two spaced apart metal sections 2, 3 connected by at least two spaced apart insulating portions 5, 6, is made from two spaced apart initially integral metal sections 2, 3 joined by one or more metal bridging webs, the one or one of which defines the bottom of a first, upwardly-open, groove (b) by filling the first groove with settable insulating material 6 (6', 6'', 18). cutting away the metal bridging web(s), turning the section over about its longitudinal axis, introducing a strip (8; 8', 8'') of material to form the bottom of a second, upwardly open, groove and filling it with settable insulating material (5; 16, 17). <IMAGE>

Description

SPECIFICATION Process and apparatus for making composite sections The invention relates to a process for making a composite section for window frames, door frames, facade structures or the like, consisting of metal sections which are arranged at a distance from one another and are made from a one-piece initial section cross-section and which are connected to one another over their length by insulating-core strips separated from one another via a cavity, and which are each separated from the cavity by a removable strip or the like bridging the gap between the metal sections, these strips forming the bottom of grooves open on one side, into which a thermoplastic is filled, in a castable state, to form the insulating-core strips, by initially bringing the first groove of the composite section under a casting device and filling it with the plastic, turning the composite section about its longitudinal axis after the plastic in the groove filled first has set, and then filling the other groove.

In a process of this type known from German Auslegeschrift 2,904,192, after the topmost groove has been filled with a casting resin and after this has set, the metal section is initially rotated about its longitudinal axis, so that subsequently the opposite groove separated by the cavity from the groove filled first can be filled with a casting resin. In a process step following this, a tool is introduced into the cavity limited by the metal bridging webs and the two bridging webs are removed.

It has been shown that this known process can be applied only to a limited number of different cross-sectional forms of composite sections. Thus, for example, difficulties arise in the production of composite sections in which the cavity crosssection falls below a specific free dimension, so that there is not always sufficient space available for introducing and handling the tool to remove the bridging webs.

In addition, special devices are necessary to carry out the known process, and the scope of use of these is restricted inasmuch as with such equipment, for example, very small section crosssections having only one metal bridging web or profile cross-sections with more than two insulating-core strips arranged above one another cannot be produced.

A process for making composite sections is known from German Auslegeschrift 2,721,367 of the Applicant, and this process provides for only one metal bridging web which forms the lower bottom covering of a cavity open at the top on one side, and in a first process step the lowest groove is filled before it is possible to begin filling the upper grooves in succession for the purpose of making the other insulating-core strips arranged above it. Because the metal sections should not be shifted out of their basic position during their entire production process, it is not possible to transfer this known process cycle to the production of composite sections with several metal bridging webs limiting cavities.

Starting from the production method mentioned in the introduction, in which the composite sections are turned during their manufacture, the object of the present invention is to provide an economical process, according to which both composite sections of small crosssectional dimensions and large section crosssections can be made, irrespective of whether they have one or more metal bridging webs.

According to the invention there is provided a process for making a composite section comprising at least two spaced apart metal sections connected by at least two spaced apart insulating portions, the process comprising the steps of: (a) using an initial integral metal section comprising two spaced apart metal sections joined by one or more metal bridging webs, the one bridging web or respectively one of the bridging webs defining the bottom of a first, upwardly-open, groove bounded on its sides by the sections; (b) bringing the first groove under a casting head and filling it with settable insulating material therefrom; (c) after setting of the insulating material, cutting away the metal bridging web(s); (d) turning the now part-formed composite section over its longitudinal axis;; (e) introducing a strip of material of low thermal conductivity spaced above the filled first groove to form the bottom of a second, upwardly open groove whose sides are defined by the two metal sections; (f) bringing the second groove under a casting head and filling it with settable insulating material therefrom.

Also according to the invention there is provided apparatus comprising means for carrying out each of the above steps. It is possible by means of the process cycle according to the invention, to make composite sections both of small and of large cross-sections in a continuous work flow. Because the metallic connection between the sections has already been eliminated in a stage before the metal sections were turned, it does not matter whether the initial section crosssections have one or more metal bridging webs, so that the cross-sectional size of the cavity limiting the height of the insulating-core strips can no longer be of importance. Furthermore, the process cycle according to the invention provided the preconditions for enabling existing production equipment to be used universally as a result of slight changes in construction.Instead of the tools which are used in the known process and which have to be introduced into the cavity of the composite sections to enable the bridging webs to be removed, it is possible to resort to existing saws or milling cutters which are always available in the production equipment.

According to a preferred embodiment of the process, after the first groove has been filled and before the bridging web or webs have been severed and the metal sections turned, at least one strip made of a material of low thermal conductivity, forming the bottom of an additional groove, is appropriately introduced, between the metal sections, at a distance above the insulating core strip formed first, and this groove is filled with plastic. As a result, it is possible to make special section forms with more than two insulating-core strips arranged above one another. In order to stabilise further the initial section cross-sections during their manufacture, it is proposed that the grooves to be filled with plastic before the metal sections are turned be opened by removing one metal bridging web.

In the manufacture of composite sections with more than two metal sections arranged next to one another, the metal bridging webs for all the insulating regions are preferably severed -simultaneously. Alternatively, however, this can also be carried out successively, to achieve a better force distribution during this processing operation. Appropriately, the introduction of the separate bottom strips for forming further grooves arranged next to one another and the filling of the grooves with plastic each take place also simultaneously.

In the case of a composite section with more than two insulating-core strips arranged above one another, it is possible, according to the invention, even after the composite section has been turned, to fill successively with casting material a number of grooves corresponding to the number of insulating-core strips. According to a special feature, in the case of a composite section with several metal bridging webs arranged above one another the removal of the latter takes place in one and the same operation.

In cases where the conditions of space so require, the composite section is, advantageously after being turned, transferred into a second transport path and, in the second transport path, is transported in a direction opposite to the conveying direction in the first transport path. The composite sections are turned and transferred to the second transport path preferably simultaneously.

The apparatus for carrying out the process, the fundamental structure of which is based on the arrangement known from German Patent Specification 2,913,254 of the Applicant and which has a base supporting the metal sections, as well as transport and guide devices for the metal sections for guiding these past underneath the first casting arrangement, and which possesses at least one further casting arrangement connected after the latter in the transport direction and a device located between two successive casting arrangements for introducing a separating strip between the metal sections, as well as an arrangement for removing one or more metal bridging webs, is characterised in that the arrangement for removing the bridging web or webs is provided, in the transport direction, behind the first casting arrangement and in front of the device for introducing the separating strip, and a station for turning the composite section about its longitudinal axis is located at a distance behind said removing arrangement. An apparatus designed in this way can be obtained with the simplest means by converting equipment already on the market, so that universal application is possible with one and the same apparatus. The apparatus designed according to the invention allows the economical production of composite sections both with only one and with several metal bridging webs in a continuous work flow, and it is merely necessary to connect or disconnect individual units for conversion of one cross-sectional form of the composite section to another.

A further device for introducing the separating strip as well as a casting arrangement are preferably located, in the transport direction, behind the first casting arrangement and in front of the arrangement for removing the bridging web or webs. As a result, it is possible to make large section cross-sections by means of a basic structure preferred in practice. In the region of the turning station, the transport path preferably merges into a second transport path extending parallel to the first transport path, and the conveying direction of the second transport path is made opposite to the conveying direction of the first transport path. This type of design is chosen when the production line is to be made as short as possible. Appropriately, the two transport paths are connected by a transfer station for the composite sections.The turning station advantageously consists of a rotating device for the composite section, and the transfer station is formed by a conveyor belt, a transport-roller conveyor or the like which transfers the composite section from the first transport path to the following transport path by means of parallel displacement.

In a further embodiment of the invention, the device for introducing the separating strips is designed as a separating-strip supply roll which is mounted on a shaft extending transversely to the transport direction and which unwinds in the transport direction at the transport speed of the metal sections. Appropriately, the drive of the separating-strip supply roll is derived from the transport movement of the metal sections.

According to another feature, a severing device for severing the trailing end of the advancing composite-section strand from the leading end of the composite-section strand adjoining the latter is provided behind the last casting arrangement.

Here, the separating device consists of a driven overhung saw or the like.

To make composite sections with several insulating zones, several casting arrangements, arrangements for removing the bridging web or webs and separating-means supply rolls, corresponding to the number of insulating zones desired, are advantageously arranged transversely to the transport device and at a distance from one another.

The invention is explained in more detail below with reference to various exemplary embodiments in conjunction with the drawings in which: Figs. 1-7 show the individual process steps during the production of a composite section with an initial section cross-section which has only one metal bridging web, Fig. 8 shows an initial section cross-section with two metal bridging webs, Fig. 9 shows a section cross-section with several insulating zones arranged next to one another, during the filling of the upper grooves, Fig. 10 shows the section cross-section according to Fig. 9, during the severing of the bridging webs, Fig. 11 shows a possible embodiment for a section cross-section with more than two insulating-core strips arranged above one another, during the severing of two bridging webs, Fig.12 shows the finished composite section made from the initial section cross-section according to Fig.11, Figs. 13 to 22 show the individual process steps in the production of a design preferred in practice for a composite section with three insulating-core strips, Fig. 23 shows the process cycle according to the invention during the passage of a composite section through the production equipment, in a diagrammatic representation and in a side view, Fig. 24 shows the process cycle according to the invention, divided into two partial transport sections, in a plan view, Fig. 25 shows the apparatus according to the invention for carrying out the process, in a side view, Fig. 26 shows a plan view relating to Fig. 25, Fig. 27 shows, in cross-section, the finished composite section made in the apparatus, Fig. 28 shows a simplified cross-section along the line XXVllI-XXVIlI in Fig. 25, seen in the region in front of the first casting arrangement in the transport direction, Fig. 29 shows a cross-section along the line XXIX-XXlX in Fig. 25, in the region in front of the severing device for removing the bridging web, Fig. 30 shows a cross-section along the line XXX-XXX in Fig. 25, in the region in front of the turning station, Fig. 31 shows the section according to Fig. 30, after it has been turned about its longitudinal axis, corresponding to the cross-section XXXl-XXXI in Fig. 25, Fig. 32 shows a cross-section along the line XXXlI-XXXIl in Fig. 25, in the region in front of the separating-strip supply roll, Fig. 33 shows a cross-section along the line XXXlIl-XXXIll in Fig. 25, in the region in front of the second casting arrangement, Fig. 34 shows a diagrammatic representation of an additional device for making a composite section according to Fig. 22, and Fig. 35 shows a diagrammatic representation of an additional device for making a composite section according to Fig. 12.

The finished composite section 1, illustrated in Fig. 7 as an example of a section cross-section, used preferably in practice, with only one bridging web, has two metal sections 2, 3 arranged at a distance from one another. Each metal section possesses projections 4 and the like which each engage positively into an insulating-core strip 5, 6 made of material of low thermal conductivity and extending over the length of the metal section so that a firm connection between the metal sections extruded, for example, from aluminium is obtained. The insulating-core strips 5, 6 together with inner walls 2', 3' limit a box-shaped cavity 7 which extends continuously over the length of the metal sections and which is separated in each case, on one side from the associated insulatingcore strip 5 by a separating strip 8.The initial section cross-section used for making the composite section according to Fig. 7 is, for example, the cross-section according to Fig. 1, the two metal sections 2, 3 of which are connected into a one-piece unit by a metal bridging web 9 extruded in one operation with the metal sections.

However, the initial sections used can also be cross-sectional forms which have two or more pressed-on bridging webs 1 0, 11 or 12, 14 and 13, 1 5 (Fig. 8 or 10 respectively) or 10, 11, 23' (Fig.11) or 10',11 (Fig. 13), and which offer the advantage of greater stability and good dimensional accuracy in the extrusion operation.

This advantage has a positive effect especially in the case of large section cross-sections. However, even in the case of smaller sections, initial crosssections having more than one bridging web between two metal sections are often demanded.

Figures 9 and 10 illustrate an initial section cross-section which has three metal sections 2, 3 and 3' which are arranged next to one another and of which the metal sections 3, 3' are connected by a bridging web 12 and the metal sections 2, 3' by a bridging web 13. As is evident, the bridging webs 12. 13 are arranged next to one another and separated by the metal section 3'. It is also possible, however, to provide, in each insulating zone A and B respectively, instead of one bridging web in the example according to Fig. 9 two or more of these in accordance with the embodiment of Fig. 8, as is indicated in the cross-section according to Fig. 10 by broken lines 14. 15.

Figure 11 illustrates an alternative form of an initial section cross-section with two bridging webs 10, 11 arranged above one another, the finished composite section according to Fig.12 having, instead of two insulating-core strips arranged above one another, three insulating-core strips 1 6, 17, 1 8.

A further alternative form of a composite section having three insulating-core strips 16', 17', 1 8' is evident from Fig. 22. This compositesection design is used for preference in practice when the aim is to produce relatively large crosssections, the initial section cross-sections of which have two or more metal bridging webs 10', ', 11" as shown in Fig. 13.

A composite section is produced according to the invention from an initial section cross-section as shown in Fig. 1 in the following process steps: In the first place, the two metal sections 2, 3 are extruded as a one-piece section unit and are pretreated in a known way (for example by anodising). In a subsequent process step (Fig. 2), the upper groove 20 limited laterally by the walls 19 of the metal sections 2, 3 facing one another and at the bottom by bridging web 9 is filled by means of a casting head 25 with a commercial thermoplastic 21 as an insulating casting material, the bridging web 9 serving, at the same time, as a bottom covering of the groove 20.After the plastic 21 has set in the groove and solidified into the insulating-core strip 6, the bridging web 9 between the metal sections 2, 3 is removed over part of its width, for example by means of a saw 22, a milling cutter or the like (Fig. 3).

Subsequently, the section is turned by rotating it through 1 800 about its longitudinal axis (Fig. 4).

The position of the section after being turned is shown in Fig. 5. After this, the separating strip 8 is introduced between the metal sections (Fig. 6) and rests, at the level of the height of the cavity 7, on lateral web projections 23 of the metal sections, its purpose being to form the bottom covering of a further groove 24. In a last process step, the groove 24 is filled with the plastic 21 from a casting head 29. After it has hardened, the second insulating-core strip 5 is obtained, and the composite section ready for further processing.

The process cycle described with reference to the initial section cross-section according to Fig. 1 takes place, in a corresponding way, in the production of the other composite sections illustrated.

In the case of the initial section cross-section according to Fig. 8, the two bridging webs 10, 11 arranged above one another are removed, by means of the saw 22 shown by broken lines, in one operation, that is to say the two bridging webs are severed simultaneously or approximately simultaneously. Severing can, of course, take place in another suitable way, for example by cutting, tearing off, etc.

In the production of composite sections with more than two metal sections arranged next to one another, as shown in Fig. 9, the two grooves are each filled simultaneously with the plastic 21.

For this purpose, two casting heads 25 arranged next to one another and connected in parallel are required instead of the one casting head 25 necessary in Fig. 2. In a corresponding way, in these sections, the bridging webs 12, 13 or 12, 14 and 13, 15 in Fig. 10, which are arranged next to and above one another respectively, are removed simultaneously, after the insulating-core strips 6', 6" have been formed, by saws 22 arranged in parallel and next to one another. In composite sections with two or more insulating zones A and B, it must ge assumed, basically, that all identical operations, such as filling the grooves, removing the bridging webs, introducing separating strips, can always be carried out simultaneously during the process cycle.

The composite section according to Fig. 12 is made from the initial section cross-section according to Fig. 11 in the same process steps as those described with reference to Figs. 1 to 7, with the sole difference that, after the insulatingcore strip 18 has been formed in the groove filled first with plastic and after the bridging webs 10, 11 have been removed and the section turned, two grooves are filled successively with plastic 16, 17, instead of one additional groove, after the associated separating strips 8', 8" have been placed, as bottom coverings for the grooves 24' and 24 respectively, on to the web projections 23' immediately before the casting operation.

Figures 14 to 22 illustrate a process cycle in which, as distinct from the production method described for a composite section with three insulating-core strips according to Fig. 12, only one groove, not two grooves, is filled with plastic after the metal sections have been turned, whilst the other two insulating-core strips are produced before turning. The illustration in Fig. 13 will make it clear that for extrusion reasons it is possible, in principle, to provide all conceivable initial crosssections with a bridging web 11" which closes the section at least on one outer side and which therefore has to be removed again before the start of the casting operation.Starting from the initial cross-section according to Fig. 14, prepared in this way, the middle groove 76 is first filled with plastic 21 from the casting head 25, so that the insulating-core strip 17' is obtained (Fig.15).

Subsequently, a separating strip 8" is placed on to the web projections 23 located above the insulating-core strip (Fig.16), and the groove 77 formed in this way is filled with plastic from the casting head 25' (Fig. 17). After this, the webs 10',11 are severed by means of the saw 22 (Fig. 18), the section is turned (Fig. 19, 20), and the last groove 78 is formed by putting a separating strip 8 in place (Fig. 21) and is filled with plastic from the casting head 29 (Fig. 22).

Figure 23 again illustrates diagrammatically the production of a composite section according to Fig. 7. Here, the first casting head for filling the particular uppermost groove of each section 2, 3 is designated by 25, the turning station located behind the saw 22 in the conveying direction 26 is designated by 27, the device for introducing the separating strip is designated by 28 and the casting head for filling the groove to be filled last is designated by 29.

In relation to the process cycle illustrated in Fig. 23, Fig. 24 shows an alternative form of the process which differs from that mentioned first in that, after being turned in the turning station 27, the composite section 2, 3 is transferred from the first transport direction 26, by means of parallel displacement in the direction of the arrow 30, into a second transport path in which the section is transported counter to the conveying direction 26 in the direction of the arrow 31 towards the device 28 for introducing the separating strip and towards the second casting head 29.In this process, the turning and transfer of the sections to the second transport path extending parallel to the first can take place simultaneously if, for example, the turning operation is carried out by hand or via a suitable rotating device not shown and if the cross-transport of the section in the direction of the arrow 30 takes place via a driven conveyor belt 33 mounted on rollers 32. This alternative form of the process is used for preferance in practice when the available length of a fabrication shop is not sufficient for a straight-line process cycle according to Fig. 23.

The apparatus for making a composite-section in the design according to Fig. 27, which is identical to the cross-section shown in Fig. 7, has a horizontally arranged work table 34 (Fig. 25 and 26) which is supported on the ground by means of feet 35. The work table 34, which can also consist of any other suitable base, for example can also be divided into several tables (Fig. 23), has a supporting surface for the metal sections 2, 3 which, during their processing into composite sections 1, are transported on the predetermined transport path in the direction of the arrow 26 between rollers 36, 37. The rollers 36, 37 are mounted on vertical shafts 36', 37' on the work table 34.The rollers 36 on one side of the table are fastened unrotatably on the shafts 36' and are driven by these, whilst the rollers 37 located on the other side are driveless and serve merely as abutments for the metal sections 2, 3 carried along as a result of friction via the driven rollers 36. The drive source for the rollers 36 is a motor 38, the drive pinion 39 of which drives a shaft 41 via a gear wheel 40. The shaft 41 carries over its length at the intervals of the rollers 36 bevel wheels 42 which mesh with corresponding bevel wheels 43. The bevel wheels 43 are keyed on to the shaft ends 36' which project under the work table 34 and which transmit to the rollers 36 the drive movement originating from the motor 38.

Located above the work table 34 is a first casting arrangement 25 consisting of a casting head 25' and a discharge nozzle 25". The casting head 25 is connected via a line 44 to a castingresin supply vessel 45 and is suspended adjustably on a mounting 46 fastened to the work table 34. The casting material used is known casting resins which are discharged in a liquid state from the discharge nozzle 25" of the casting arrangement 25 and which solidify after a short setting time. The casting material is conveyed via a pump not shown. The plastic 21 is discharged from the casting head 25', according to the process step shown in Fig. 2, into the upper groove of the section.

Located at a distance behind the first casting arrangement 25 is a metal saw 22 with a circular saw blade which is keyed onto a shaft 47 and which is driven via a motor 47' fastened to the table 34 (Fig. 29). Appropriately, the saw 22 is suspended so as to be vertically adjustable according to the double arrow 48. The saw blade 22 is made so narrow that it has sufficient play in the cavity 7 (Fig. 3) between the sections 2, 3, and during transport of the metal sections in the direction of the arrow 26 the metal bridging web 9 can be removed continuously, without obstruction, from the lower side of the section.

The roller 75 (Fig. 29) suspended on the frame 72, 73 via a rotatable spindle 74 serves for guiding the composite sections in a vertical direction, especially for absorbing the counter pressure during removal of the bridging webs.

As soon as the trailing end 49 of the composite section 2, 3 has passed the saw 22, the composite section enters the turning station 27, within the length of which there are neither transport rollers 36 nor the corresponding counter-rollers 37, so that the section can be rotated about its longitudinal axis by hand by means of a suitable rotating device (not shown) out of the position shown in Fig. 4 into the position according to Fig. 5.

Located immediately after the leading end 50 of the metal section outside the turning station 27 is a supply roll 51 for the separating strip 8 which, during the advancing movement of the composite section is introduced continuously into the groove 24 in the place provided for this purpose. The coil 51 located at a distance above the groove 24 is mounted on the axle 52 which extends transversely to the transport direction 26 and which is received freely rotatably in bearings 53, 54 supported on the work table 34 via bearers 55.

Located after the separating-strip supply roll 51 is a separating-strip guide 56 which temporarily arches the separating strip 8 in a transverse direction by means of guide rollers 57, 58 and a convexly curved baffle 59, in order to make it easier to place this separating strip on the receiving webs 23 in the grooves 24.

Also located after the separating-strip supply roll 51 and the separating-strip guide 56 in the transport direction 26 is a pressure roller 61 which is mounted freely rotatably on a pivoting lever 60 and which serves to press the separating strip 8 on to the supporting webs 23 for the intermediate bottoms of the grooves, in order to achieve as uniform and as close a contact as possible of the separating strip 8 along the supporting webs. The pivoting lever 60 is mounted, at its end facing away from the pressure roller 61, on an axle 62, the two ends of which are supported in bearing shells 63 fastened to the work table 34 via bearers 64. To exert the necessary pressure on the separating strip 8, the pivoting lever is springloaded or weight-loaded.

Located after the separating-strip supply roll 51 in the transport direction 26 is the second casting arrangement 29, the structure of which corresponds to that of the first casting arrangement 25 and which has accordingly a casting head 66, a discharge nozzle 67, a connecting line 68, a casting-material supply vessel 69 and a mounting 70. The plastic 21 is discharged into the groove 24 from the casting head 66.

The metal sections 2, 3 filled with casting material in the way described are transported further on the work table 34 at a constant conveying speed after they have passed the last casting arrangement 29. As soon as the casting material in the groove 24 filled last has also solidified, the advancing metal-section strand 50 reaches a severing device which consists of an extension 34' of the work table 34 and the supporting surface of which is bent at an angle to the work table.As a result of this, because of the lack of support in this region, the advancing metal section 2', 3' inclines downwards as a result of its own weight and breaks off at the weakest point, which is located at the joining point between the rear end face 49' of the leading metal section 2', 3' and the front end face 50 of the metal section 2, 3 directly adjoining this, and is thus severed from the following section strand. Since the only connection between the two section strands is formed by the two partial insulating cores 5, 6 which have solidified in the meantime and by the continuous separating strip 8, the breaking or tearing-off point lies in the partial insulating cores and the separating strip.It is, of course, also possible to sever the connected section strands at their joining point by means of a suitable saw 70 indicated by dot-and-dash lines in Fig. 25, instead of the severing device described, in which case this saw should appropriately be arranged so as to be movable perpendicularly to the transport direction (arrow 71), to allow it to be activated without interrupting the transport.

Likewise, severing by hand or even mechanically by means of scissors, a knife or the like is also conceivable.

To produce a section design according to Fig. 22, it is merely necessary to arrange, in the transport direction 26 behind the first casting arrangement 25 of the apparatus illustrated in Fig. 25, an additional separating-means supply roll 51 and a further casting arrangement 25"" at a distance from this. This apparatus is shown diagrammatically in Fig. 34.

To produce the composite section according to Fig. 12, in which the insulating core 18 is formed first and the insulating core 17 is formed after turning and introduction of the separating strip 8' in the groove 24', it is necessary, in the apparatus according to Fig. 25, to connect after the casting arrangement 29 a separating-means supply roll 51" for introducing the separating strip 88 and after this a further casting arrangement 29' for the insulating core 16, to make it possible to fill the groove 24 to be filled last (Fig. 35).

Otherwise, the apparatus according to the invention works in the same way as described in German Patent Specification 2,913,254.

Claims (28)

1. A process for making a composite section comprising at least two spaced apart metal sections connected by at least two spaced apart insulating portions the process comprising the steps of: (a) using an initial integral metal section comprising two spaced apart metal sections joined by one or more metal bridging webs, the one bridging web or respectively one of the bridging webs defining the bottom of a first, upwardly-open, groove bounded on its sides by the sections; (b) bringing the first groove under a casting head and filling it with settable insulating material therefrom; (c) after setting of the insulating material, cutting away the metal bridging web(s); (d) turning the now part-formed composite section over about its longitudinal axis;; (e) introducing a strip of material of low thermal conductivity spaced above the filled first groove to form the bottom of a second, upwardly open, groove whose sides are defined by the two metal sections; (f) bringing the second groove under a casting head and filling it with settable insulating material therefrom.

2. A process according to claim 1 for producing a composite section comprising a right and left and a centre metal section spaced apart and parallel to one another with the centre metal section being joined to the right metal section by two spaced apart insulating portions and the centre section also being joined to the left metal section by two spaced apart insulating portions, the process comprising the steps of:: (a) using an initial integral metal section comprising parallel right, centre and left metal sections spaced apart and joined up by one or more right bridging webs between the centre and right metal sections and one or more left bridging webs between the centre and left metal sections, the or one of the right bridging webs defining the bottom of a right first, upwardly open, groove bounded on its side by the right and centre sections, and the or one of the left bridging webs defining the bottom of a left first, upwardly open, groove bounded on its sides by the left and centre sections; (b) bringing both the right and the left first groove under a casting head and filling each with insulating material therefrom; (c) after setting of the insulating material in the right and left first grooves respectively cutting away the right and left bridging webs respectively;; (d) turning the now part-formed composite section over about its longitudinal axis; (e) introducing above each of the right and the left first grooves a strip of material of low thermal conductivity to form respectively the bottom of respective right and left, upwardly open, second grooves whose sides are defined by the right and centre metal section parts and the left and centre metal section parts respectively; (f) bringing each of the left and right second grooves under a casting head and filling it with settable insulating material therefrom.

3. A process according to claim 2 wherein at step (b) the right and left first grooves are filled simultaneously.

4. A process according to claim 2 or 3 wherein at step (c) the right and left bridging webs are cut away simultaneously.

5. A process according to claim 2 or 3 wherein at step (c) the right and left bridging webs are cut away successively.

6. A process according to any one of claims 2 to 5 wherein at step (d) the strip of material is introduced simultaneously above the right and the left first groove.

7. A process according to one of claims 2 to 6 wherein at step (e) the right and left second grooves are filled simultaneously.

8. A process according to any preceding claim wherein intermediate steps (b) and (d) there is introduced a strip of material of low thermal conductivity spaced above the or each first groove to form the bottom of a third upwardly open groove whose sides are defined by the same two metal sections as define the sides of the respective first groove, and the or each respective third groove is brought under a casting head and filled therefrom with settable insulating material.

9. Process according to any preceding claim wherein the initial integral metal section used comprises at least two metal bridging webs joining the or each initially joined pair of metal sections, and prior to step (a) one such bridging web between the or each pair is cut away to expose the upwardly open first groove between such pairs of metal sections.

10. Process according to any preceding claim wherein after step (f) there is introduced a further strip of material of low thermal conductivity spaced above the or respectively above each of the filled second grooves to form the bottom of a respective further, upwardly open groove whose sides are defined by the same metal sections as define the sides of the filled second groove below it, and the or each further groove is brought under a casting head and filled with settable insulating material therefrom.

11. Process according to any preceding claim wherein at step (c) between the or each pair of metal sections more than one metal bridging web remains, and these are all simultaneously cut away at step (c).

12. A process according to any preceding claim wherein the settable insulating material is a thermoplastic.

13. A process according to any preceding claim wherein steps (b) and (c) are performed while conveying the composite section in one direction in a first transport path and steps (e) and (f) are performed while conveying the composite section in the opposite direction along a second transport path.

14. A process according to claim 13 wherein the step (d) of turning the composite section and transfer from the first to the second transport path take place simultaneously.

15. A process for making composite sections substantially as hereinbefore described with reference to the embodiment of Figs. 1 to 7, or Fig. 8, or Figs. 9 and 10, or Figs. 11 and 12, or Figs. 13 to 22, or Fig. 23 or Fig. 24 of the accompanying drawings.

16. A composite section when made by the process of any one of the claims 1 to 1 5.

17. Apparatus for carrying out the process of claim 1, comprising: (a) means for transporting an initial integral metal section in a direction parallel to its longitudinal axis along a transport path to be treated in succession by the following means (b) to (f); (b) a first casting head adapted to deliver settable insulating material; (c) means for severing bridging webs of the metal section; (d) means for turning the part-formed composite section about its longitudinal axis; (e) means for introducing a separating strip; (f) a second casting head adapted to deliver settable insulating material.

18. Apparatus for carrying out the process of claim 2, comprising: (a) means for transporting an initial metal section in a direction parallel to its longitudinal axis along a transport path to be treated in succession by the following means (b) to (f); (b) a pair of first casting heads mounted above the transport path to deliver settable insulating material to different locations in the metal section; (c) a pair of means for severing the bridging webs at two different locations in the metal section; (d) means for turning the now part-formed composite section about its longitudinal axis; (e) a pair of means for introducing a separating strip into the metal section at different locations; (f) two second casting heads for delivering settable insulating material to different locations in the composite section.

19. Apparatus according to claim 18 wherein each of the pairs (b), (c), (e), and (f) are mounted next to one another transverse to the transport path.

20. Apparatus according to one of claims 17.

18, or 19 wherein the means (a) for transporting comprises first means for transporting an initial integral metal section along a first transport path in one direction past means (b) and (c) as far as means (d) for turning, and second means for transporting the now partly formed and turned composite section from the means (d) for turning along a second transport path in the opposite direction past means (e) and (f).

21. Apparatus according to claim 20 wherein the means (a) for transporting further comprises transferring means for transferring the section from the first to the second transport path.

22. Apparatus according to claim 21 wherein the transferring means is a conveyor belt or transport roller conveyor, which transfers the section transversely to its longitudinal axis.

23. Apparatus according to any one of claims 17 to 22 wherein the or each means for introducing a separating strip comprises a separating-strip roll mounted on a shaft extending transversely of the transport direction and having a drive adapted to unwind the strip at the speed of the metal sections in the transport direction.

24. Apparatus according to claim 23 wherein the drive for the or each roll is derived from the transport movement of sections.

25. Apparatus according to any one of claims 17 to 24 wherein there is provided in the transport path subsequent to the second casting heads (f) a severing device for severing a web joining the trailing end of one metal section to the leading end of the next following metal section.

26. Apparatus according to claim 25 wherein said severing device is a driven overhung saw.

27. Apparatus according to any one of claims 17 to 26 wherein intermediate means (b) and (c) there is located means for introducing a separating strip above the or each first filled groove of the section, and casting heads for delivering insulating material onto the inserted separating strips.

28. Apparatus substantially as hereinbefore described with reference to the embodiment of Figs. 25 to 33 or Fig. 34 or Fig. 35 of the accompanying drawings.