Section bar for fixtures constituted by a section bar made of metallic or plastic material, having cross-sectional section preferably opened, which is firmly coupled to a laminated plastic profile having structural and decorative function   

The present invention regards an innovative sectional element for door frames and window frames for the residential and industrial building sector, substantially comprising at least one sectional element with open cross section (for example, made of aluminium, steel, PVC, or other material that is suitable for producing door and window frames), which is coupled to at least one laminated plastic, preferably of the HPL (High Pressure Lamination) type or of the DPL (Direct Pressure Lamination) type, having a structural and decorative function.

Coupling together of said materials to obtain door frames and window frames is completely innovative in the building sector, since as of today there do not exist sectional elements that adopt coupling of materials of this sort.

The firms that produce aluminium sectional strip (drawing mills), have so far devised systems of production of their own or ranges of sectional strip divided, in turn, into different series in order to meet the market requirements.

Each series is studied for a particular type of application; consequently, the series for doors and windows comprises all the sectional elements necessary for manufacturing these products. A series can be made up even of hundreds of sectional elements different from one another and all studied for a particular function so as to be combined together according to a single design scheme to offer specific types with a wide range of variants, according to the different performance requirements or the different aesthetic and architectural choices of use. Given the same dimensional characteristics, and the same features of accuracy of the machining operations and of design, in conformance with the specifications of the manufacturer, the mechanical performance and sealing and weatherproofing performance of the door and window frames obtained with the majority of the systems currently available on the market are adequate to provide good guarantees

The manufacturer accompanies each series with the terms of specifications, which describe the characteristics and performance both of a dimensional nature and of a weatherproofing nature, together with the certifications of testing that are obtained by means of stringent tests conducted at specialized and recognized institutes and bodies.

The families of series of sectional elements are divided according to the type of openings to which they are to be applied, for example: series for leaf opening, for sliding opening, for internal mobile walls designed for offices, for continuous facades, etc. The largest category is evidently that of sectional elements for swing doors and windows, which enables doors, windows, or shutters to be made.

In turn, the series of sectional elements differ from one another both as regards the more or less large section of the sectional elements and as regards their very composition. Available in the known art, in fact, are normal sectional elements or ones that are thermally cut. The choice of the section depends, not only upon economic and aesthetic choices, but also upon the dimensions and consequent kinds of performance that are to be obtained.

To be included in the category of thermally cut sectional strip are also the series with mixed aluminium-wood sectional strip, which enable the dual advantage of an aesthetic appearance closer to traditional forms of furnishing, whilst at the same time guaranteeing the qualities of seal and convenient maintenance of aluminium, which in this case constitutes just the external part of the door frame or window frame. The choices in the individual series of the colourings proposed for aluminium are, however, limited, and likewise even more limited are the types and colourings of the wood. The adoption of door frames and window frames that are built using thermally cut sectional strip and are appropriately glazed with double glazing enables, notwithstanding the corresponding costs, an energy saving over time that on average is adequate as compared to the service life of the frame itself.

The disadvantages presented by the current technologies of production of door and window frames are thus linked to the ratio between characteristics of performance and price, as well as to the aesthetic choice of the end product, which is at times very limited in the individual series of sectional strip, also in aluminium-wood combinations.

It should be borne in mind that, in the case of aluminium sectional strip, a surface finishing different from the standard ones envisaged for that type of sectional strip can have costs that are very high if not even prohibitive, without taking into account the fact that certain finishes or aesthetic effects cannot be obtained on aluminium.

In addition, a further disadvantage of known types of sectional strip is represented by the fact that, since they are all characterized in that they present a closed cross section, the average weight of a door or window frame made of aluminium (dimensions: 130×230 cm with open joints), excluding the accessories and the window panes, is not less than 24 kg; for the thermally cut version, the weight may even reach 34 kg. The weight factor is not negligible in so far as the cost of aluminium is calculated on a weight basis.

The main purpose of the present invention is to reduce the costs of production of door and window frames considerably, given the same performance features, improving the aesthetic and functional characteristics thereof, by providing a door or window frame that can be mass produced, is practical to install, is ergonomic, and may assume widely varied aesthetic appearances, as well as presenting a low final cost for the user.

A further purpose of the present invention is to provide a door or window frame 1 that can be applied to replace door and window frames that are already installed and in service, without the need for any modification of the architectural parameters.

The above and other purposes are obtained by providing a sectional element for door and window frames for the residential and industrial building sector, said sectional element being characterized in that it is made up of two structural elements that can be rigidly fixed to one another: a first structural element preferably made of aluminium and having a preferably open cross section, and a second structural element made of laminated plastic having preferably also a decorative function.

A better understanding of the present invention will be obtained from the ensuing detailed description thereof, with reference to the attached plate of drawings, which illustrate by way of non-limiting example some preferred embodiments of the invention and some variants thereof.

In the plate of drawings:

FIG. 1, which regards a first embodiment of the invention, in which the structural element made of laminate is on the internal face of the door or window frame and is fixed to the first structural element by means of at least two slot-in elements, is a cross-sectional view of the lateral part of a door or window frame in an area corresponding to a hinge;

FIG. 2 is a cross-sectional view of a first variant of the first embodiment of the invention, regarding the central part of a door or window frame with two mobile leaves;

FIG. 3 is a cross-sectional view of a second variant of the first embodiment, regarding a side intersection of the door or window frame;

FIG. 4 is a cross-sectional view of a third variant of the first embodiment, regarding a central intersection of the door or window frame;

FIG. 5 is a cross-sectional view of a fourth variant of the first embodiment, regarding an overlapping frame;

FIGS. 6 and 7, which are similar to the previous one, show further variants of the first embodiment of the invention, regarding a coplanar frame;

FIG. 8, regarding a second embodiment of the invention in which the structural element made of laminate is present both on the internal face and on the external face of the door or window frame and is fixed to the first structural element by means of at least two slot-in elements, is a cross-sectional view of a side intersection of the door or window frame;

FIG. 9, which is similar to the previous one, regards a central intersection of the door or window frame;

FIG. 10, regarding a third embodiment of the invention in which the structural element made of laminate is present both on the internal face and on the external face of the door or window frame, is a cross-sectional view of a side intersection of the door or window frame, in which the outer laminate is a sandwich containing insulating material, such as for example polystyrene; and

FIGS. 11 to 17 regard further variants of the second embodiment of the invention, in which the element made of laminate is fixed to the aluminium element via a shoulder and a single slot-in element.

With reference to the figures listed above, the inventive idea underlying the present invention substantially consists in having devised a sectional element for door and window frames in which the side facing the inside and/or the one facing the outside is formed by a structural element made of laminated plastic, which is rigidly fixed to a structural element made of metal or plastic having an open cross section. According to a peculiar characteristic of the invention, the sectional strip for door and window frames thus obtained has a closed cross section which is designed to provide the strength and stiffness required for the uses for which it is designed.

A first embodiment of the invention, shown in different variants in FIGS. 1 to 7, envisages a sectional element for door and window frames substantially made up of two structural elements made of different materials, which are fixedly and rigidly coupled to one another: the first structural element P comprises at least one aluminium sectional element having an open cross section, which is closed by the presence of the second structural element L, which comprises at least one laminated plastic, preferably of an HPL or DPL type, which is rigidly fixed to the former so as to form a single body therewith.

Advantageously, the aforesaid laminated plastic L possesses excellent aesthetic and decorative characteristics and can be easily produced so that it presents a practically infinite number of colours and finishings, such as for example the wood effect that reproduces the vein and the colours of any type of wood extremely faithfully. In addition to this, it may be noted that the invention is characterized also by a marked constructional simplicity with evident saving in production costs. In fact, the coupling between the aluminium sectional element P and the laminated plastic L is obtained by simple pressure fitting of the latter on particular longitudinal tabs A made on the aluminium sectional strip itself during the process of drawing and can assume various shapes, preferably a dove-tailed shape. Obviously, in the thickness of the laminate L, longitudinal grooves must previously be made, designed to house the tabs A.

During the longitudinal insertion of the tabs A of the aluminium sectional element P in the respective grooves of the laminate L, it is preferable to apply glue or adhesive of a known type (for example, resins or other bonding means suitable for fixing the two materials together), which improves the mutual joining between the laminate L and the aluminium sectional element P.

The invention combines the advantage of being simple to produce, with a further advantage regarding the simplicity in installation, which is convenient even for a worker without particular skill.

The aluminium sectional elements P according to the invention (which may even be of a thermally cut type) are made using known production techniques, but are characterized by open sections and by thicknesses of the sectional strip smaller than those traditionally produced up to now.

The laminated plastic L is obtained following recently developed manufacturing techniques, which envisage the use of high pressures.

Basically, there exist two major types of laminate: the HPL (High Pressure Laminated) type and the DPL (Direct Pressure Laminated) type. The HPL type, which can be used in the preferred embodiment of the invention, is obtained at high pressure and is formed substantially by a series of cellulose fibres impregnated with phenolic resins and compacted by pressing at a high temperature. This is the best technique for obtaining the laminate, in so far as the high pressure guarantees a greater compactness of the various layers and hence a greater resistance to impact and wear. The DPL type is obtained by pressing the decorative layer directly on the support, thus obtaining a result that is more economical, but is usually less resistant.

The laminate L constituting the internal surface or external surface of the sectional element for door and window frames according to the first embodiment of the present invention can be made up also of a series of plastic layers compacted together by pressing at high temperature (thermosetting-plastic sintering).

The high strength and the durability both in regard to abrasion and in regard to light and heat, with a prolonged maintenance of the finish and of the colour that characterize the sectional element for door and window frames described herein are due precisely to the constructional characteristics of the laminate L.

As is known, appropriately shaped weatherproofing elements G are used in the areas corresponding to the striking surfaces and/or for purposes of finishing.

A second embodiment of the invention, shown in different applications in FIGS. 8 and 9, and 11 to 17, together with some variants thereof, envisages that the second structural element formed by the laminated plastic L preferably of the HPL type is provided both on the internal side and on the external side of the sectional element for door and window frames described herein.

In this case, it is advantageously possible to envisage configurations of the first structural element P, preferably consisting of aluminium sectional strip 10 with open cross section, in which said sectional strip is even reduced to two aluminium laminas arranged substantially in a direction perpendicular to the external and internal laminated plastic L (see FIG. 8, sectional element on the left). In this way, the weight of the aluminium used in the production of the sectional strip for door and window frames according to the invention is drastically reduced. If it is considered that the ratio between the cost per kilogram of HPL and the cost per kilogram of aluminium is approximately 1:6, it is evident that saving on the weight of aluminium used in each door or window frame means a considerable reduction in the total costs.

It should be noted that, as an alternative to the pair of tabs A preferably, but not exclusively, arranged in a dove-tailed fashion, according to the invention, it is possible to envisage the use of a single tab A and a shoulder (see, for example, FIG. 11, right-hand sectional element and left-hand sectional element), thus obtaining an improvement of the finish of the end edges without the use of weatherproofing G. A third embodiment of the invention, shown in FIG. 10, envisages that the laminated plastic L provided on the outside of the sectional strip for door and window frames according to the invention, is formed by a sandwich panel in which the insulating internal part is made of polystyrene or polyurethane or some other suitable material, whilst its two outer skins are made with the aforesaid laminated plastic L, preferably HPL.

Other advantages of considerable importance are the extreme ease of fixing of the laminate L on the aluminium sectional element P with traditional techniques, as likewise the practical absence of any need for maintenance over time.

The procedure of assembly in the production stage and during installation are identical to the ones of traditional door and window frames, but with the further advantage of a reduction in the weights of said frames, once again given the same characteristics of performance, especially with reference to the traditional frames built using sectional strip of the thermally cut type made of aluminium or mixed aluminium-wood.

In this connection, it is worthwhile noting that, as compared to an average weight of approximately 24 kg of a normal door or window frame made of aluminium (without accessories), according to the present invention frames are obtained, the average weight of the aluminium alone of which, given the same level of performance, is reduced to 14 kg in the case where the laminate L is only on one side of the door or window frame, and reaches as little as 11 kg in the case where the laminate is on both the external side and the internal side of the frame.

With reference to FIGS. 8-17 and in particular to FIGS. 16 and 17, which at a first glance may look identical to one another, it is pointed out that, with profiles of the structural elements P that are identical and profiles of the structural elements L that are different in width, it is possible to obtain cross sections of variable width optimizing the production in number of the sectional elements P. It is also expedient to choose the materials for the production of the sectional elements for door and window frames described herein so that they will possibly be recyclable in order to reduce the production of waste.

From what has been said, it is clear that the sectional strip for door and window frames according to the present invention is simple to produce, of reliable technical feasibility, and is further characterized by a final cost that is particularly limited thanks to the reduction of the amount of aluminium required.

Another advantage of the invention is the provision, through the fitting in various ways of said laminated plastic L on said aluminium sectional element P that is unlikely to deteriorate, of a door or window frame that is particularly durable and resistant also in regard to atmospheric agents. As compared to traditional mixed aluminium-wood sectional strip, the innovative sectional strip for door and window frames described herein enables frames to be obtained that are characterized by: lower costs of the materials of which they are made; lower costs of the process of fabrication; consequent lower costs for the final user; internal and/or external layer with structural and aesthetic functions, having any colouring or aesthetic finish, the thickness of which is increased from 50 μm to more than 0.4 mm, which minimize the unaesthetic effects of the edges at the corner joints of traditional aluminium sectional elements; higher thermal insulation given the same thickness of the door or window frame obtained; absence of condensate on the internal surface of the door or window frame; resistance to impact of the internal surface and/or laminated plastic higher than that presented by wood, as likewise improved ease of cleaning, no absorption of humidity and vapour; total resistance to mould and woodworm; greater resistance to wear over time; better resistance to fire; and optimization of the aesthetic appearance and of the overall functionality.

The door or window frame thus obtained presents also the advantage of being, on account of its greater lightness, practical in use on account of the fact that it is easier to maneuver even for elderly and disabled persons, given the same characteristics of performance with traditional door and window frames.

In conclusion, it is worthwhile noting that, according to the invention, as an alternative to the aluminium sectional elements P fixed to which is the laminate L, sectional elements made of steel or PVC can be used, or else ones made of any other material suitable for use in the production of door and window frames, maintaining all the advantages described above unaltered.

Finally, it is to be noted that the advantages of the invention are obtained also by combining a sectional element P with a closed cross section with at least one laminate L either HPL or DPL, with the difference that the reduction in the weight of aluminium present in the door or window frame is less accentuated with respect to the preferred embodiments described above (FIGS. 5 and 7).

The present invention has been illustrated in some preferred embodiments and in different variants thereof, but is clear that modifications and/or replacements that are technically or functionally equivalent may be made by a person skilled in the branch, without thereby departing from the sphere of protection of the present industrial patent right.