FR2721065A1 - Metal frame for window, door or similar - Google Patents

Abstract

The frame consists of two parallel extrusions (21, 22), each with one face in contact with the outside atmosphere or the interior of a building, separated by a hollow prefabricated spacer of a material with low thermal conductivity and with a thermal expansion coefficient similar to that of the extrusions. The spacer is situated in a gap between the two extrusions and is fixed to them with a suitable adhesive. The spacer is tubular in shape and has two flat projecting surfaces (25, 26) for attaching to the extrusions. It can also be divided by lengthwise partitions into a number of separate chambers. The spacer is made from a moulded or extruded polymer based composition material with natural or synthetic fibres, esp. of glass, or of PVC reinforced with a mineral or other charge. It can also incorporate a thin layer of an acoustic insulating material made from an elastomer thermoplastic or visco-elastic material, placed between the spacer and one of the extrusions.

Description

 The present invention relates to a door frame, window or the like, in metal joinery, in particular consisting of aluminum profiles suitably assembled, comprising means suitable for ensuring a thermal break, that is to say to reduce, if not almost completely prohibit a heat transfer between the external face of the chassis in contact with the external atmosphere, generally cooler and the internal face, in contact with the room or other, including the door or window considered, at a higher temperature .

 We know that the problem of heat transfer between the interior and the exterior of a room via the metal door or window frames of the aforementioned type, is particularly difficult to solve, the profiles which form this frame leading to the calories by creating a cold feeling on contact with them in the room, favoring the appearance of condensation phenomena on the interior faces of this chassis, with any detrimental runoff if necessary.

 To overcome this drawback, provision has already been made to create a thermal break in the profiles forming the frame of the door or window, preventing this transfer of calories, in particular by integrating a zone between the external and internal faces of the chassis. low thermal conductivity, which however should not harm the rigidity of the assembly and in particular the mutual cohesion of the profiles which form these faces.

 The most conventional solutions thus consist in constituting the metal sections which form the frame of the chassis, either by means of two half-sections which have been produced separately, or produced by cutting and separating two parts of the same single initial section, these half-sections being assembled by means of an intermediate member with low thermal conductivity.

 A first variant consists in filling a rebate or an open groove in the profile, the cross-section of which has approximately the shape of a U, with a thermosetting insulating resin, of the polyurethane type, to fill the space defined between two metallic webs. generally parallel to the profile and the bottom of the groove which connects these sails. Once the resin block has hardened and secured to the walls of the U-shaped groove, mechanical machining is carried out to remove the bottom of the groove over the height or length of the profile as appropriate, the two webs then being connected one to the other only by the block of insulating resin which thermally separates them and ensures the desired thermal bridge break.

 This technology is made delicate, in particular because of the milling operation necessary to remove the metal connecting element between the two webs which form the facing half-sections joined by the hardened resin block, the passage to be reserved for the tool limiting the shapes of profiles likely to be used.

 An improvement also known in the art consists in making successively two deposits of resin in order to obtain two bars separated by an air space. This configuration has better thermal insulation but requires a relatively complicated implementation and increases the final cost of the profile.

 This solution is however limited to a profile having a limited width dimension, the bars produced cannot be thicker than 10 mm.

In addition, this technology is to be excluded for half-profiles which must have different colors, towards the inside and outside of the chassis.

 Finally, the casting of the resin block can lead to a deformation of the two half-sections, modifying their parallelism with, if necessary, exceeding the permissible manufacturing tolerances.

 A second variant consists in separately producing bars of an insulating material, of the polyamide type, with reinforcement by glass fibers, these bars having in themselves sufficient rigidity, and in placing these bars between the two half-profiles of the chassis, their assembly being obtained by crimping the ends of these bars in grooves previously formed in these half-profiles.

 However, this second embodiment, more conventional, also has drawbacks, in particular for achieving a suitable crimping of the ends of the bars in their receiving grooves. These bars must indeed have a special shape which leads to excess material and to significant widths of the final profile. In addition, to obtain a sufficient connection, it is often necessary to make, inside the grooves for receiving these bars, notches or the like, allowing the metal to be anchored in the material of the bar.

 However, in this case and as for the previous solution, the shape of the profiles capable of being produced is limited, due to the need to leave the crimping rollers adequate access to the heads of the receiving grooves. In addition, the connection made is not waterproof by itself, in particular in the case of anodized profiles, which requires additional interventions during the subsequent manufacture of the door or window frame, which increase its price by returns, the cost of the bars being moreover not negligible in itself.

Finally, due to the temperature differences between the two half-profiles joined by the polyamide bars and the method of assembly with each other, it can be seen that, despite the presence of these insulating bars, the half-profiles undergo, due to their non-identical expansions, a bending effect which can hinder in certain cases the functioning of the chassis, in particular the movement, by sliding
of the opening vis-à-vis the frame of the door or window considered.

 The present invention relates to a metal carpentry frame with thermal break which largely avoids the drawbacks of conventional solutions, mainly in one case the lack of parallelism of the two half-profiles and in the other the effect for bending the chassis.

 To this end, the frame for door or window according to 1 invention, comprising two metal half-profiles extending parallel to each other with a face respectively directed towards the external atmosphere for one, towards the inside a room comprising the door or window for the other, these two half-profiles being assembled with each other, is characterized in that it comprises, between the two half-profiles, a hollow intermediate element, prefabricated, with a straight section closed on itself, made of a material with low thermal conductivity and whose coefficient of thermal expansion is close to that of the half-sections, this element being housed in the space delimited between them and secured to these half-sections -profiles through an appropriate bonding medium.

 Preferably, the intermediate element is tubular and has in its cross section at least two projecting parts, flat and capable of being applied against bearing surfaces facing the two parallel half-sections.

 According to an alternative embodiment, the intermediate element has several air spaces formed by a plurality of chambers adjacent to each other between the two half-sections, in a direction perpendicular to them.

 In a preferred embodiment of the invention, the bonding means is constituted by a structural adhesive, having approximately the same coefficient of expansion and a modulus of elasticity intermediate between that of the two half-profiles and that of the intermediate element.

 As a variant, however, the bonding means may consist of a flat tape, having two adhesive faces, respectively applied one against the tubular element on a flat part projecting therefrom and the other on the facing surface of the half-profile.

 Depending on the case, the intermediate element is produced by means of a polyamide and is obtained by molding or extrusion. Also, it can be made by means of a composite material based on polyester and fibers, natural or synthetic, in particular glass fibers, or even be formed using polyvinyl chloride, reinforced by fillers, mineral or others.

Other characteristics of a chassis according to the invention will become apparent from the following description of an exemplary embodiment, given by way of non-limiting example, with reference to the appended drawings in which
- Figures 1 and 2 are schematic cross-sectional views of profiles with thermal break, in accordance with solutions currently known in the art for this type of product.

- Figures 3 and 4 are cross-sectional views of a profile produced in accordance with the invention, the parts constituting this profile being shown in exploded view on the
Figure 3 and, once assembled, in Figure 4.

 - Figure 5 illustrates an alternative embodiment of the tubular element used in the example of Figures 3 and 4. In Figure 1, the reference 1 designates a metal profile used in particular in the manufacture of a door frame, window or the like, this profile comprising at least two metallic webs, respectively 2 and 3, extending generally parallel to one another.

 The particular structure of the profile 1 is in itself indifferent with respect to the object of the invention, this profile may include a closed section on itself 4, an open rebate 5, grooves 6 or 7 of sections separate from each other, for mounting seals (not shown) or connecting means with various accessories (also not shown).

 In order to achieve a thermal break between the two webs 2 and 3, in particular to reduce to the greatest possible extent a transfer of calories from one to the other when these are in contact with atmospheres at different temperatures, a block of resin 8, usually a polyurethane resin, is used according to a technique known per se, this block being cast inside an open groove provided in the profile between the webs 2 and 3. These advantageously comprise external projections penetrating into the groove, respectively designated by the reference 9 for the web 2 and by the reference 10 for the web 3, allowing improved anchoring of the resin block 8 on these facing webs.

 The resin block is contained between the two webs 2 and 3 by a metal connecting part 11 which forms the bottom of the U-shaped groove formed between these two webs.

 Once the resin thus placed suitably hardened so as to constitute a connecting interlayer between the webs 2 and 3, a profile 1 is machined, in particular to eliminate in the metallic part 11 a strip 12 forming a bridge over all the length or the height of the profile according to its position in the frame of the door or window, these two sails then only being joined together via block 8, which thermally insulates the two sails.

 In FIG. 2, on which the same reference numbers have been used to designate bodies similar to those envisaged in the variant of FIG. 1, the two half-sections 2 and 3 are directly braced when they are assembled by means of two strips, respectively 13 and 14, previously manufactured and having ends 15 crimped inside receiving grooves 16 coming from manufacturing with the half-profiles. In this variant, which avoids in situ machining of the resin block 8 envisaged in the previous one, the bars 13 and 14 are preferably made of polyamide reinforced with glass fibers, so as to have sufficient rigidity by itself.

 In both embodiments, it can however be seen that the solutions proposed are not perfectly satisfactory, in the first case due to the constraints imposed by the machining of the profile 1 in order to eliminate the connecting strip 12 and the resistance over time of the junction which is not perfect.

 In the first case, the casting of the resin block 8 in fact tends to break the parallelism of the webs 2 and 3 and to harm compliance with the manufacturing tolerances imposed for the profile.

In the second, in addition to the fact that the proposed solution does not make it possible to effectively oppose a certain bending of the opposite faces of the chassis, the crimping of the ends 15 of the bars 13 and 14 requires the use of rollers which require sufficient space between the two half-sections 2 and 3, which can lead to unnecessary material surplus or to too large widths of the final section. In addition, to improve the connection between the bars and the half-profiles, it is often necessary to make a notching of the grooves 16. Since the connection obtained is not always waterproof, it is necessary to perfect it on the final chassis. , which increases the cost price of the latter.

 Figures 3 and 4 illustrate, before and after assembly, the solution proposed according to the invention for producing a profile 20 consisting of two half-profiles 21 and 22, similar to those used in the above-mentioned conventional solutions and about which can make the same observations.

 But in this new variant, the thermal break between the two half-profiles 21 and 22 is achieved by means of an intermediate element 23 with a tubular profile, extending along the length of the two half-profiles and housed between them ci in an intermediate space 24.

 Advantageously, the intermediate element 23 has lateral projecting parts, respectively 25 and 26, adapted to come to bear against flat surfaces 27 and 28, facing the two half-profiles when these are assembled one with the other by trapping between them the intermediate element 23 (Figure 4).

 Preferably, the intermediate element 23 is made of a material having a low thermal conductivity, in particular polyamide. I1 is obtained by molding or extrusion and has a coefficient of thermal expansion close to that of the two half-sections and a modulus of elasticity intermediate between that of these two half-sections and that of the interlayer. In addition, this intermediate element is secured to the half-profiles by means of an adhesive disposed between the protruding parts 25 and 26 and the bearing surfaces 27 and 28 of the half-profiles, this so-called "structural" adhesive, being chosen so that that it has a coefficient of expansion and a modulus of elasticity close to those of the half-sections and of the intermediate element, in order to form with these a rigid assembly and which is particularly well opposed to the effects of thermal expansion possibly created between the external and internal faces of the two half-sections 21 and 22.

 In the example described, the intermediate element 23 has a single internal chamber. As a variant, this element has several air spaces formed by adjacent chambers in the space which separates the half-profiles 21 and 22. Thus and as illustrated in FIG. 5, the element can comprise a median separation, delimiting two chambers, respectively 29 and 30, which significantly increases the thermal insulation obtained with a single tubular element.

 This produces a frame for door or window, in metal joinery, in which the thermal break is particularly effective. The assembly has a minimum cost and makes it possible to obtain the best compromise between the useful width of the insulating intermediate element and the maximum thickness of the profile formed by the assembly of the two half-profiles on either side of this element..

 Of course, it goes without saying that the invention is not limited to the embodiment more specifically described with reference to the accompanying drawings; on the contrary, it embraces all variants. In particular, instead of using a structural adhesive directly connecting the projecting parts of the intermediate element and the surfaces facing the half-profiles, provision may be made for the use of a double-sided adhesive tape, one ensuring the connection with the half-profile and the other with the insulating tubular element, this on each side of the latter.

 The invention also makes it possible, in a profile of the type considered, not only to improve the thermal break between the two half-profiles of the chassis, but also to increase the performance of the latter from a point of view. acoustics, this particular problem being at the present time treated essentially by an improvement of the sealing of the metal joinery and an attenuation of the transmission of sound at the level of the glazing.

 According to the invention, it is possible to obtain a substantial attenuation, by interposing between the intermediate element and one of the half-profiles, a thin layer of an energy-absorbing material, in particular of the thermo-plastic elastomer type or viscoelastic material, placed in contact with one of the aluminum half-profiles, exterior or interior.

 The thickness of this layer is limited, of the order of 1 to 2 mm, so as not to reduce the rigidity of the chassis too significantly, necessary to enable it to exhibit resistance to the effects of wind, mainly on central uprights of the double-leaf striking windows.

 Advantageously, the absorbent thin layer is applied against the intermediate element forming the thermal break by any suitable method. In addition, the assembly thus formed can be produced with one of the half-profiles by coextrusion, making it possible to obtain an assembly consisting of two adjacent parts made of different materials and between which the connection is made hot during manufacture.

Claims (8)

 1 - Frame in metal joinery, for door, window or the like, with thermal break, comprising two metal half-profiles (21, 22) extending parallel to each other with a face respectively directed towards the external atmosphere for one, towards the inside of a room comprising the door or window for the other, these two half-profiles being assembled with each other, characterized in that it comprises, between the two half -profiles, a hollow intermediate element (23), prefabricated, with a cross section closed on itself, made of a material with low thermal conductivity and whose coefficient of thermal expansion is close to that of the half-profiles, this element being housed in the space (24) delimited between them and secured to these half-profiles by means of an appropriate bonding means.  2 - Chassis according to claim 1, characterized in that the intermediate element (23) is tubular and has in its cross section at least two projecting parts (25, 26), flat and capable of being applied against bearing surfaces in look (27, 28) of the two parallel half-sections.  3 - Chassis according to one of claims 1 or 2, characterized in that the intermediate element (23) has several adjacent chambers (29, 30) to one another between the two half-profiles (21, 22 ), in a direction perpendicular to them.  4 - Frame according to any one of claims 1 to 3, characterized in that the bonding means is constituted by a structural adhesive having the same coefficient of expansion and the same modulus of elasticity as the two half-profiles (21, 22) and the insert (23).  5 - Frame according to any one of claims 1 to 3, characterized in that the bonding means is constituted by a flat tape, having two adhesive faces, respectively applied one against the tubular element (23) on a part projecting plane (25, 26) thereof and the other on the facing surface (27, 28) of the half-profile (21, 22).  6 - Chassis according to any one of claims 1 to 5, characterized in that the intermediate element (23) is produced by means of a polyamide obtained by molding or extrusion, or by means of a composite material based on polyesters and fibers, natural or synthetic, in particular glass fibers, or even using polyvinyl chloride, reinforced with fillers, mineral or other.  7 - Chassis according to any one of claims 1 to 6, characterized in that the intermediate element (23) comprises a thin layer of an acoustically insulating material of the type of thermoplastic or visco-elastic elastomer material , disposed between this element and one of the metal half-sections (21, 22).  8 - Chassis according to claim 7, characterized in that the intermediate element and the thin layer of acoustic insulation are obtained by co-extrusion with one of the half-profiles (21 or 22).