Mechanical connector for prefabricated units for the exterior covering of buildings

Abstract

The present invention relates to a mechanical connector 10 for a prefabricated unit 28 for the exterior covering of a building 30. The mechanical connector comprises: a central plate 12, which develops in a plane wh; an upper secondary plate 14 and a lower secondary plate 16, structurally connected to the central plate along the direction w, which develop in a plane dw; two eyebolts 18, structurally connected to the upper secondary plate along the direction d, which protrude upwards in the plane dh; two constraint plates 20, structurally connected to the lower secondary plate along the direction d, which protrude downwards in the plane dh; two hook plates 22, structurally connected to the central plate along the direction h, which develop in the plane dh and wherein each hook plate comprises a bayonet 24 which develops downwards. The mechanical connector is obtained from one single flat and continuous blank 26, by means of successive foldings. The invention further relates to a prefabricated unit comprising the mechanical connector and a method for installing such prefabricated unit in a building site.

Description

[0001] MECHANICAL CONNECTOR FOR PREFABRICATED UNITS FOR THE EXTERIOR COVERING OF BUILDINGS

[0002] TECHNICAL FIELD

[0003] The present invention relates to a mechanical connector for the installation of prefabricated units intended to constitute the exterior covering of buildings, whether existing or newly built. The invention further relates to the prefabricated unit comprising the mechanical connector, as well as the method for installing the prefabricated unit. STATE OF THE ART

[0004] In the field of construction, the use of the so-called curtain wall is widely known. In accordance with this solution, the exterior covering of the building is made by applying a multitude of elements, called prefabricated units, juxtaposed to each other. Usually the curtain wall involves an extensive use of glass; however, the panels of the exterior covering can also be made with other materials, depending on specific technical or aesthetic needs.

[0005] In recent times, curtain wall covering is enjoying renewed interest due to the ease with which it can integrate insulating, ecological, photovoltaic materials, thus allowing to obtain environmentally and energy efficient solutions. Furthermore, the curtain wall lends itself to being applied both to new buildings and to existing buildings that must undergo renovation or energy upgrading.

[0006] As part of the curtain wall covering, prefabricated multi-layer modular elements are usually used which are called prefabricated units. These units usually comprise an outer frame, made with extruded profiles or other elongated elements, preferably made of steel or aluminium, but also of wood. This frame encloses in its inside one or more panels juxtaposed with each other to give the desired technical and aesthetic characteristics to the covering. In particular, the specific arrangement of the panels defines an inner side, intended to be arranged towards the building, and an outer side, intended to be arranged towards the outer environment. The frame encloses the panels, holds them together and gives strength to the assembly.

[0007] Once delivered to the building site, each unit must be installed on the wall of the building, in the position for which it is intended. For this purpose, bayonets are applied on the inner side of the unit, which are configured to be received in corresponding eyelets of respective brackets, previously provided on the wall of the building.

[0008] In addition, each prefabricated unit must also be lifted, usually by means of a crane or other lifting apparatus, up to the position for which it is intended. For this purpose,each unit also comprises a pair of eyebolts, which in a well-known manner, guarantee as many safe anchoring points for lifting on the building site.

[0009] Finally, the prefabricated units often comprise a box-shaped section, called a string course or belt course, preferably placed at the upper end of the element. The string course, usually intended to be arranged at the respective slab of the building, also performs some important functions of a technical nature, for example that of introducing a thermo -soundproof and fireproof barrier that helps limit the vertical transmission, from a lower floor to an upper floor, of hot air, noise as well as fire, if any.

[0010] Typically all these components (the bayonets, the eyebolts, the box-shaped section as well as the insulating materials housed in it that make up the string course) are assembled together to form a mechanical connector. The mechanical connector is therefore applied at the upper part of the frame of the unit. All these assembly steps take place using classic constraint devices, typically screws, but also rivets, nails, weldings, gluings and the like.

[0011] The prefabricated units and the respective mechanical connectors of known type, although widely appreciated, are not free from defects. More in particular, a very felt significant disadvantage is the complexity of the manufacture of the mechanical connectors themselves, deriving from the large number of components to be assembled. The assembly of a large number of components by means of numerous mechanical constraint devices is an activity that requires a lot of time and labour and therefore involves high costs.

[0012] Furthermore, a complex assembly, which involves a large number of actions, is naturally more prone to errors, which can easily lead to the manufacture of an unsatisfactory or even dangerous mechanical connector.

[0013] In addition, despite the fact that the prefabricated units are mainly manufactured in a production facility remote from the building site off-site), some specific components, such as the insulating materials to be introduced in the string course, must often be added at the building site on-site). This implies additional difficulties as well as potential waste of material, in consideration of the sub-optimal conditions in which the on-site installers themselves will be operating.

[0014] WO 2013 / 151466 provides an example of a mechanical connector, for the installation of prefabricated units, in accordance with the prior art.

[0015] The need is therefore felt for a new type of prefabricated unit and of the relative mechanical connector that improve the known solutions.

[0016] OBJECTS AND SUMMARY OF THE INVENTIONThe object of the present invention is therefore to overcome the drawbacks highlighted above in relation to the prior art.

[0017] In particular, a task of the present invention is to make available a mechanical connector for a prefabricated unit that is simple and economical to manufacture.

[0018] Furthermore, a task of the present invention is to make available a mechanical connector for a prefabricated unit that allows to reduce the intrinsic risk of errors in the assembly step.

[0019] Still, a task of the present invention is to make available a mechanical connector for a prefabricated unit that facilitates the performance of all assembly operations off-site.

[0020] Finally, a task of the present invention is to make available a mechanical connector for a prefabricated unit which, in addition to the advantages connected to the new technical features introduced, allows to maintain at least in part the advantages obtained by the known solutions.

[0021] These and other objects and tasks of the present invention are achieved by means of a mechanical connector for a prefabricated unit in accordance with claim 1. Further features are identified in the dependent claims. All appended claims form an integral part of the present disclosure.

[0022] The invention relates to a mechanical connector for a prefabricated unit for the exterior covering of a building. The mechanical connector of the invention comprises:

[0023] - a central plate, which develops in a direction h and in a direction w, perpendicular to each other;

[0024] - an upper secondary plate and a lower secondary plate, structurally connected to the central plate along the direction w, wherein both the secondary plates develop in the direction w and in a direction d, perpendicular to the directions h and w; - two eyebolts structurally connected to the upper secondary plate along the direction d, wherein both the eyebolts protrude upwards, develop in the directions d and h;

[0025] - two constraint plates, structurally connected to the lower secondary plate along the direction d, wherein both the constraint plates protrude downwards, develop in the directions d and h; and

[0026] - two hook plates, structurally connected to the central plate along the direction h, wherein both the hook plates develop in the directions d and h, and wherein each hook plate comprises a bayonet which develops downwards.

[0027] Furthermore, the mechanical connector of the invention is obtained from onesingle flat and continuous blank, by means of successive foldings.

[0028] This particular structure makes it possible to obtain a particularly simple and economical mechanical connector.

[0029] Preferably, one or more of the following relationships occur in the mechanical connector of the invention:

[0030] - the upper secondary plate and the lower secondary plate are arranged on opposite sides of the central plate along the direction h; and / or

[0031] - the two eyebolts are arranged on opposite sides of the upper secondary plate along the direction w; and / or

[0032] - the two constraint plates are arranged on opposite sides of the lower secondary plate along the direction w; and / or

[0033] - the two hook plates are arranged on opposite sides of the central plate along the direction w.

[0034] Each of these relationships identifies a particularly efficient feature for the structure of the mechanical connector of the invention.

[0035] Preferably, the whole extension of the hook plates in the direction d is greater than the extension in the same direction d of the constraint plates.

[0036] This particular solution ensures that the bayonets assume an optimal position for the installation of the prefabricated unit on the outer surface of a building.

[0037] Preferably the distance between the two constraint plates in the direction w is equal to the distance between the two eyebolts in the same direction d. Preferably the extension of the constraint plates in the direction d is greater than or equal to the extension in the same direction d of the eyebolts.

[0038] These features make it possible to install in a particularly efficient manner two prefabricated units of the invention that are identical to each other and overlapping one another on the outer surface of a building. In particular, these features allow the upper prefabricated unit to be received between the two eyebolts of the lower prefabricated unit.

[0039] Preferably the mechanical connector encloses a service volume, comprised within the two secondary plates, the two hook plates and the central plate. This service volume is filled up with fireproof and / or insulating material.

[0040] This feature allows to obtain an effective string course.

[0041] The invention further relates to a prefabricated unit for the exterior covering of a building, comprising a mechanical connector in accordance with what is described above and a multi-layer module. The multi-layer module comprises a structural frame and oneor more panels side by side with each other.

[0042] Such a prefabricated unit allows to make the best use of the features of the mechanical connector of the invention.

[0043] Preferably, the structural frame comprises a peripheral groove within which the two constraint plates are received, each on one side.

[0044] This solution allows to obtain a particularly comfortable and effective constraint between the mechanical connector and the structural frame.

[0045] The invention further relates to a method for installing prefabricated units for the exterior covering of a building. The method of the invention comprises the steps of:

[0046] - providing a building;

[0047] - providing on the outer surface of the building, in positions pre-defined in a design step, a plurality of brackets comprising eyelets; and

[0048] - providing a plurality of prefabricated units in accordance with what is described above.

[0049] The method of the invention further comprises the iterative steps of:

[0050] - lifting a prefabricated unit and bringing it at the brackets provided for receiving it in the design position;

[0051] - inserting the bayonets of the mechanical connector into the eyelets of the brackets; - releasing the prefabricated unit in the design position.

[0052] Such a method makes it possible to install particularly efficiently the prefabricated units of the invention to obtain the exterior covering of a building.

[0053] Preferably, the prefabricated units are manufactured in a production facility remote from the building site.

[0054] This solution allows prefabricated units to be manufactured under particularly favourable conditions.

[0055] Further features, aims and advantages of the present invention will become more evident from the description below.

[0056] BRIEF DESCRIPTION OF THE DRAWINGS

[0057] The invention will be described below with reference to some examples, provided for explanatory and non-limiting purposes, and illustrated in the annexed drawings. These drawings illustrate different aspects and embodiments of the present invention and reference numerals illustrating structures, components, materials and / or similar elements in different drawings are indicated by similar reference numerals, where appropriate. Moreover, for clarity of illustration, certain references may not be repeatedin all figures.

[0058] Figures 1 schematically represent successive steps of the building site of a new building, in which prefabricated units are used in accordance with the invention;

[0059] figures 2.a-2.c schematically represent successive steps of the building site for upgrading an existing building, in which prefabricated units are used in accordance with the invention;

[0060] figure 2.d schematically represents an enlarged view of the detail indicated with D in figure 2.b;

[0061] figure 3 schematically represents an exploded view of a possible prefabricated unit in accordance with the invention;

[0062] figure 4 represents an axonometric view, partially in transparency, of a mechanical connector in accordance with the invention;

[0063] figure 5 schematically represents a flat blank intended for the manufacture of a mechanical connector in accordance with the invention;

[0064] figures 6 schematically represent some successive steps of the manufacture of the mechanical connector of figure 4 starting from the blank of figure 5;

[0065] figure 7 schematically represents the step of the constraint between the mechanical connector and the respective multi-layer module to form a prefabricated unit of the invention; and

[0066] figure 8 schematically represents the step of the vertical coupling between two prefabricated units of the invention.

[0067] DETAILED DESCRIPTION OF THE INVENTION

[0068] While the invention is susceptible to various modifications and alternative constructions, certain preferred embodiments are shown in the drawings and are described hereinbelow in detail. It must in any case be understood that there is no intention to limit the invention to the specific embodiment illustrated, but, on the contrary, the invention intends covering all the modifications, alternative and equivalent constructions that fall within the scope of the invention as defined in the claims.

[0069] The description deals in detail with the peculiar aspects and technical features of the invention, while the aspects and the technical features per se known can only be hinted at. In these respects, the information provided above regarding the prior art remains valid.

[0070] The use of "for example", "etc.", "or" indicates non-exclusive alternatives without limitation, unless otherwise indicated. The use of "comprises" and "includes" meanscomprises or includes, but not limited to", unless otherwise indicated.

[0071] The invention is intended to operate in the presence of gravity acceleration g. Based on the gravity acceleration g, the vertical direction and the horizontal directions are uniquely defined. Similarly, with respect to the gravity acceleration g, the terms "high", "upper", "above" and similar are defined with respect to the terms "low", "lower", "below" and similar.

[0072] The invention relates to a mechanical connector for a prefabricated unit intended to be installed on the facade of a building. In relation to the final use configuration, the terms "inner", "interior" and the like are intended to indicate a position relatively close to the building, while the terms "outer", "exterior" and the like are intended to indicate a position relatively far from the building.

[0073] The invention relates to a mechanical connector for a prefabricated unit, indicated as a whole with reference 10. The mechanical connector 10 of the invention comprises:

[0074] - a central plate 12, which develops in a direction h and in a direction w, perpendicular to each other;

[0075] - an upper secondary plate 14 and a lower secondary plate 16, structurally connected to the central plate 12 along the direction w, wherein both the secondary plates 14, 16 develop in the direction w and in a direction d, perpendicular to the directions h and w;

[0076] - two eyebolts 18 structurally connected to the upper secondary plate 14 along the direction d, wherein both the eyebolts 18 protrude upwards, develop in the directions d and h;

[0077] - two constraint plates 20, structurally connected to the lower secondary plate 16 along the direction d, wherein both the constraint plates 20 protrude downwards, develop in the directions d and h; and

[0078] - two hook plates 22, structurally connected to the central plate 12 along the direction h, wherein both the hook plates 22 develop in the directions d and h, and wherein each hook plate 22 comprises a bayonet 24 which develops downwards.

[0079] Furthermore, the mechanical connector 10 of the invention is obtained from one single flat and continuous blank 26, by means of successive foldings.

[0080] In the description of the invention that follows, reference is made by convention to the directions w, h and d, perpendicular to each other, indicating respectively the width, height and depth of the mechanical connector 10 (see figure 4). For convenience, reference is also made to the planes dw, dh and wh, identified respectively by the different pairs of axes. The mechanical connector 10 is described in its design use configuration, wherein the plane wh of the central plate 12 is arranged vertically, with the eyebolts 18extending upwards and the constraint plates 20 extending downwards. As the skilled person can well understand, nothing would change if different conventions were adopted.

[0081] In light of the above, the geometric characteristics of the mechanical connector 10 of the invention can also be expressed as follows:

[0082] - the central plate 12 develops in the plane wh;

[0083] - the upper secondary plate 14 and the lower secondary plate 16, develop parallel to the plane dw; and

[0084] - the eyebolts 18, the constraint plates 20 and the hook plates 22 develop parallel to the plane dh.

[0085] Preferably, the central plate 12 defines an outer face and an inner face. Advantageously, the two secondary plates 14, 16 and the two hook plates 22 develop in the direction d towards the inner face. In this way, the central plate 12 is arranged in the more external position of the mechanical connector 10.

[0086] Preferably in the mechanical connector 10 of the invention, one or more of the following conditions occur:

[0087] - the upper secondary plate 14 and the lower secondary plate 16 are arranged on opposite sides of the central plate 12 along the direction h; and / or

[0088] - the two eyebolts 18 are arranged on opposite sides of the upper secondary plate 14 along the direction w; and / or

[0089] - the two constraint plates 20 are arranged on opposite sides of the lower secondary plate 16 along the direction w; and / or

[0090] - the two hook plates 22 are arranged on opposite sides of the central plate 12 along the direction w.

[0091] Preferably, the whole extension of the hook plates 22 in the direction d is greater than the extension in the same direction d of the constraint plates 20. In other words, the bayonets 24, supported by the hook plates 22, protrude inwards with respect to the constraint plates 20. Preferably, the whole extension of the hook plates 22 in the direction d is greater than the extension in the same direction d of the eyebolts 18. In other words, the bayonets 24, supported by the hook plates 22, protrude inwards with respect to the eyebolts 18.

[0092] Preferably, the distance between the two constraint plates 20 in the direction w is preferably equal to the distance between the two eyebolts 18 in the same direction d.

[0093] Preferably the extension of the constraint plates 20 in the direction d is greater than or equal to the extension in the same direction d of the eyebolts 18.The mechanical connector 10, while maintaining the structure described above, can assume different dimensions and proportions, depending on the specific needs that are defined during the design phase. For example: the extension of the mechanical connector 10 in the direction w is linked to the width of the prefabricated unit 28, which is usually defined based on aesthetic and, to a lesser extent, structural evaluations; the extension of the mechanical connector 10 in the direction d is linked to the thickness of the prefabricated unit 28, which is usually defined based on the desired energy and insulating performance; finally the extension of the mechanical connector 10 in the direction h is linked to the thickness of the slab of the building 30, which is defined based on structural evaluations.

[0094] As mentioned, the mechanical connector 10 of the invention is obtained from one single flat and continuous blank 26, by means of successive foldings. In some embodiments, in addition to the foldings, it is possible to join different parts of the mechanical connector 10 to give the latter greater rigidity or greater strength. For example, in some embodiments, it is possible to constrain between them the lower end of each eyebolt 18 to the upper end of the respective hook plate 22 and / or the lower end of each hook plate 22 to the upper end of the respective constraint plate 20.

[0095] A possible method, for obtaining the structure of the mechanical connector 10 described above, is illustrated in the attached figures and will be described below in more detail. In a manner known per se, at the beginning of the manufacture, the blank 26 is completely comprised in the plane wh of the central plate 12. successively, thanks to the successive foldings, the mechanical connector 10 assumes its final three-dimensional shape. Note that in figure 5, in which the two-dimensional blank 26 is represented and the mechanical connector 10 is not yet defined, the triad of directions d, w and h is assumed to be integral with the central plate 12.

[0096] As the skilled person can well understand, the fact that the blank 26 is defined as "two-dimensional" represents a simplification. In fact, the extension of the blank 26 in the two directions of the plane wh is clearly greater than the thickness of the sheet of metal from which the blank 26 is cut out. This enables considering the substantially two-dimensional blank 26 at the beginning of the method for manufacturing the mechanical connector 10.

[0097] Of course, different considerations must be made when calculating the mechanical characteristics of the mechanical connector 10, typically in terms of rigidity and strength. In this case, of course, in addition to the intrinsic characteristics of the material used, all dimensions acquire their own importance, including the thickness of the sheet metal. In this regard, it should be considered that, depending on the applications, the thickness of the sheet metal can advantageously be comprised between 6 mm and 8 mm.As mentioned above, the mechanical connector 10 of the invention is obtained from one single flat and continuous blank 26. Preferably, said blank 26 is cut out from a sheet of metal, advantageously from a sheet of steel metal.

[0098] Preferably, the blank 26 is cut out from the sheet of metal by means of a cutting technology that guarantees a high precision and above all a high repeatability. In fact, in order to be able to meet the needs of a single building site, the mechanical connector 10 must be made in a large number of pieces that must comply with rather strict tolerances. Cutting technologies that are particularly suitable for carrying out the invention are those with numerical control such as laser cutting and plasma cutting.

[0099] As mentioned above, the mechanical connector 10 of the invention is obtained from the blank 26 by means of successive foldings. Preferably the foldings define 90° angles. As with cutting, for folding, too, it is also preferable to adopt a technology that guarantees a high precision and above all a high repeatability. Folding technologies particularly suitable for carrying out the invention are those performed by numerically controlled folding machines or presses.

[0100] The following describes a method that allows obtaining a mechanical connector 10 in accordance with the invention, starting from one single flat and continuous blank 26. Figure 5 schematically represents the blank 26 immediately after the operation of cutting and of defining the folding lines. In particular, in figure 5, the dashed lines represent the cuts, therefore the outer edges of the blank 26, while the solid lines represent the folding lines. Figure 5 also shows triangles showing the direction in which the fold must be made along the single folding line.

[0101] Preferably, the blank 26 comprises, in a central position, the central plate 12 which, in figure 5, shows its outer face. From each side of the central plate 12, the two hook plates 22 depart, specularly in the direction w, and two elongated elements 32, 34 depart, in the direction h. The upper elongated element 32 comprises the upper secondary plate 14 from which the two eyebolts 18 extend specularly, in opposite directions along the direction w. Similarly, the lower elongated element 34 comprises the lower secondary plate 16 from which the two constraint plates 20 extend specularly, in opposite directions along the direction w.

[0102] Figure 6. a represents the blank 26 after two folding operations carried out on each of the two elongated elements 32, 34 with respect to the central plate 12, where the latter is considered integral with the plane wh. In particular, with respect to the representation of figure 5, the two elongated elements 32, 34 were folded 90° inwards (thus entering the plane of the drawing). In this way, it is passed from the substantially two-dimensional blank 26 of figure 5, entirely contained in the plane wh, to a three-dimensional semifinished product, which also develops in the direction d perpendicular to the plane wh.Figure 6.b represents the effect of the further folding operations carried out on both the elongated elements 32, 34. In particular, two 90° folds were made on the upper elongated element 32, so as to orient the two eyebolts 18 upwards and define, between them, the upper secondary plate 14. In addition, two 90° folds were made on the lower elongated element 34, so as to orient the two constraint plates 20 downwards and define, between them, the lower secondary plate 16.

[0103] Finally, figure 6.c represents the effect of the last folding operations carried out on both the hook plates 22. In particular, the two hook plates 22 were folded 90° inwards, so as to define, between them, the central plate 12.

[0104] As the skilled person can well understand, the mechanical connector 10 of the invention is extremely simple since it comprises a single piece, i.e. the blank 26. Moreover, a mechanical connector 10 of this type is inherently safe because it does not allow the operator to forget about anything, neither components nor constraint devices.

[0105] As the skilled person can well understand, the method for manufacturing the mechanical connector 10 is extremely simple since it comprises only a succession of folding operations. In addition, a method of this type is inherently safe because it allows the operator to immediately notice any errors. In fact, the application of the folding operations in an incorrect sequence results in a mechanical connector 10 being obtained that is not manifestly compliant with the design.

[0106] As the skilled person can well understand, the mechanical connector 10 encloses a service volume 36, comprised within five surfaces, i.e. defined by the two secondary plates 14, 16, by the two hook plates 22 and by the central plate 12. Said service volume 36 is preferably intended to be filled up with fireproof and / or insulating material, so as to obtain an effective string course.

[0107] As mentioned in relation to the prior art, the mechanical connector 10 of the invention is intended to be comprised in a prefabricated unit 28. For this purpose, the mechanical connector 10 is constrained at the upper end of a multi-layer module 38. An example of such a solution is schematically illustrated in figure 3, in which there are shown a mechanical connector 10 in accordance with the invention, in the upper part of the drawing, and, in exploded view, the multi-layer module 38 with its own structural frame 40.

[0108] Although the prefabricated units 28 are by themselves widely known, a general description thereof is provided here, within the limits of what may be useful for the correct understanding of the invention. The prefabricated unit 28 comprises a multi-layer module 38 and a mechanical connector 10. The multi-layer module 38 in turn comprises a structural frame 40 and one or more panels 42 side by side with each other. Preferablythe multi-layer module 38 comprises a plurality of panels 42 or layers of material, comprised between an outer panel 42', intended to be exposed outside the building 30, and an inner panel 42", intended to be facing towards the inside of the building 30. Many layers of different materials can be arranged between these two panels 42, depending on the specific technical needs. The structural frame 40 encloses and constrains with each other all the panels 42 comprised in the multi-layer module 38.

[0109] The mechanical connector 10 of the invention is configured to be constrained to the multi-layer module 38, preferably to the structural frame 40. Advantageously, the two constraint plates 20 are configured to adhere to the structural frame 40 and to be able to be firmly constrained to it, preferably at its upper end; in this regard, see the detail of figure 7. By way of example, the structural frame 40 may comprise a peripheral groove within which the two constraint plates 20 are received, each on its own side.

[0110] Preferably, as seen in figure 7, each constraint plate 20 comprises a plurality of through holes and the structural frame 40 comprises a corresponding plurality of threaded holes. In this way, once the two constraint plates 20 are approached to the structural frame 40 and placed at respective holes, it is possible to constrain the mechanical connector 10 to the structural frame 40 by means of a plurality of screws. As the skilled person can well understand, in order to constrain the mechanical connector 10 to the structural frame 40, other techniques, known per se, can be adopted, such as for example gluing, riveting, welding, etc.

[0111] Once the mechanical connector 10 is constrained to the multi-layer module 38, the finished prefabricated unit 28 is obtained, ready to be installed on-site.

[0112] As anticipated, the distance between the two constraint plates 20 in the direction w is preferably equal to the distance between the two eyebolts 18 in the same direction d. This allows that, in installing two identical prefabricated units 28 one above the other, the eyebolts 18 of the lower unit can be left in place and that the structural frame 40 of the upper unit can be received between the eyebolts 18 of the lower unit; in this regard, see the detail of figure 8.

[0113] Furthermore, the extension of the constraint plates 20 in the direction d is preferably greater than or equal to the extension in the same direction d of the eyebolts 18. This allows that, in installing two identical units one above the other, the eyebolts 18 of the lower unit can be left in place and can be received in the peripheral groove of the structural frame 40 of the upper unit.

[0114] These solutions allow at the same time to avoid the operation of removing the eyebolts 18 and to give greater strength to the assembly, defining a shape coupling between two superimposed prefabricated units 28.Although it is a known technique in itself, a method for installing the prefabricated units 28 of the invention in a building site, be it a building site of a new building 30 (see figures 1) or a renovation site of an existing building 30 (see figures 2), is briefly described below.

[0115] The method of the invention for installing prefabricated units 28 comprises some preliminary steps and some iterative steps. The preliminary steps are, in short:

[0116] - providing a building 30;

[0117] - providing on the outer surface of the building 30, in positions pre-defined in a design step, a plurality of brackets 44 comprising eyelets 46; and - providing a plurality of prefabricated units 28 in accordance with the invention.

[0118] The iterative steps are, in short:

[0119] - lifting a prefabricated unit 28 and bringing it at the brackets 44 provided for receiving it in the design position;

[0120] - inserting the bayonets 24 of the mechanical connector 10 into the eyelets 46 of the brackets 44; and

[0121] - releasing the prefabricated unit 28 in the design position.

[0122] Preferably, the prefabricated units 28 of the invention are manufactured in a production facility remote from the building site.

[0123] In more detail, in a preliminary step a building 30 is provided, which may be an existing building 30 to be renovated or a new building 30 under construction.

[0124] In another preliminary step, brackets 44 comprising eyelets 46 configured for receiving in their inside the bayonets 24 of the mechanical connector 10 are provided on the outer surface of the building 30 (see the detail of figure 2.d). More particularly, each mechanical connector 10 is configured to be coupled to respective brackets 44. Advantageously, when the mechanical connector 10 of the prefabricated unit 28 is coupled to the respective brackets 44, the prefabricated unit 28 remains hanging stably in the position pre-defined in the design step. The brackets 44 are provided in positions predefined in the design step and distributed on the outer surface of the building 30. Advantageously, the brackets 44 are positioned in such a way that the prefabricated units 28, once installed, remain adjacent to each other, so as to achieve the desired curtain wall.

[0125] To describe in more detail the iterative steps of the method of the invention, reference is made below to figures 1 and figures 2. A building site for a new building 30 is schematically shown in figures 1.

[0126] Figure l.a shows schematically the step in which a first prefabricated unit 28 according to the invention is lifted, for example by a crane. In this way, the firstprefabricated unit 28 is brought at the brackets 44 that have been previously provided on the outer surface of the building 30 to receive it.

[0127] Figure l.b schematically shows a successive step, in which the first prefabricated unit 28 is already correctly installed and occupies its own design position. To achieve this configuration, the bayonets 24 of the mechanical connector 10 have been inserted into the eyelets 46 of the brackets 44 provided on the building 30. As can be seen, in this embodiment of the method, the eyebolts 18 of the first prefabricated unit 28 have been left in place and protrude upwards with respect to the same prefabricated unit 28. In this situation, a second prefabricated unit 28 is lifted and brought at the brackets 44 (not shown) provided for receiving it.

[0128] Figure l.c schematically shows a successive step, in which also the second prefabricated unit 28 is correctly installed and occupies its own design position. As can be seen, the second prefabricated unit 28 was inserted between the eyebolts 18 of the first prefabricated unit 28, in a manner similar to that described above in relation to figure 8. In this way, a shape constraint is achieved between the two superimposed prefabricated units 28.

[0129] Reference is now made to figures 2, in which a building site for the renovation of an existing building 30 is shown schematically.

[0130] Figure 2. a shows schematically the step in which a first prefabricated unit 28 according to the invention is lifted, for example by a crane.

[0131] In figure 2.b the first prefabricated unit 28 is brought at the brackets 44 that have been previously provided on the outer surface of the building 30 to receive it.

[0132] Figure 2.c schematically shows a successive step, in which the first prefabricated unit 28 is already correctly installed and occupies its own design position. To achieve this configuration, the bayonets 24 of the mechanical connector 10 have been inserted into the eyelets 46 of the brackets 44 provided on the building 30. As can be seen, in this embodiment of the method, the eyebolts 18 of the first prefabricated unit 28 have been left in place and protrude upwards with respect to the same prefabricated unit 28. In this situation, a second prefabricated unit 28 is lifted and brought at the brackets 44 (not shown) provided for receiving it.

[0133] As the skilled person can well understand, the repetition of the iterative steps of the method allows to install all the prefabricated units 28, vertically superimposed on each other, as described above, and side by side laterally with each other, so as to obtain the desired curtain wall.

[0134] As the skilled person can well understand, the invention overcomes the drawbacks highlighted above in relation to the prior art.In particular, the invention makes available a mechanical connector 10 for a prefabricated unit 28 that is simple and economical to manufacture.

[0135] Furthermore, the present invention makes available a mechanical connector 10 for a prefabricated unit 28 which allows to reduce the intrinsic risk of errors in the assembly step.

[0136] Furthermore, the present invention makes available a mechanical connector 10 for a prefabricated unit 28 that facilitates the performance of all assembly operations off-site.

[0137] Finally, the present invention makes available a mechanical connector 10 for a prefabricated unit 28 which, in addition to the advantages connected to the new technical features introduced, allows to maintain at least in part the advantages obtained by the known solutions.

[0138] The description reported above in particular delves into the innovative aspects of the invention and the differences between this and the known solutions. For all other aspects, known in themselves, that the invention shares with the prior art, what is described in the introductory part in relation to the known solutions remains valid.

[0139] In conclusion, all the details can be replaced by other technically equivalent elements; the features described in relation to a specific embodiment can also be used in the other embodiments; the materials used, as well as the contingent shapes and dimensions, can be any according to the specific implementation needs without leaving the scope of protection of the following claims.

Claims

CLAIMS1. Mechanical connector (10) for a prefabricated unit (28) for the exterior covering of a building (30), wherein the mechanical connector (10) comprises:- a central plate (12), which develops in a direction h and in a direction w, perpendicular to each other;- an upper secondary plate (14) and a lower secondary plate (16), structurally connected to the central plate (12) along the direction w, wherein both the secondary plates (14, 16) develop in the direction w and in a direction d, perpendicular to the directions h and w;- two eyebolts (18) structurally connected to the upper secondary plate (14) along the direction d, wherein both the eyebolts (18) protrude upwards, and develop in the directions d and h;- two constraint plates (20), structurally connected to the lower secondary plate (16) along the direction d, wherein both the constraint plates (20) protrude downwards, and develop in the directions d and h; and- two hook plates (22), structurally connected to the central plate (12) along the direction h, wherein both the hook plates (22) develop in the directions d and h, and wherein each hook plate (22) comprises a bayonet (24) which develops downwards; andwherein the mechanical connector (10) is obtained from one single flat and continuous blank (26), by means of successive foldings.

2. Mechanical connector (10) according to claim 1, wherein:- the upper secondary plate (14) and the lower secondary plate (16) are arranged on opposite sides of the central plate (12) along the direction h; and / or- the two eyebolts (18) are arranged on opposite sides of the upper secondary plate (14) along the direction w; and / or- the two constraint plates (20) are arranged on opposite sides of the lower secondary plate (16) along the direction w; and / or- the two hook plates (22) are arranged on opposite sides of the central plate (12) along the direction w.

3. Mechanical connector (10) according to claim 1 or 2, wherein the whole extension of the hook plates (22) in the direction d is greater than the extension in the same direction d of the constraint plates (20).

4. Mechanical connector (10) according to one or more of the preceding claims, wherein the distance between the two constraint plates (20) in the direction w is equal to thedistance between the two eyebolts (18) in the same direction d.

5. Mechanical connector (10) according to one or more of the preceding claims, wherein the extension of the constraint plates (20) in the direction d is greater than or equal to the extension in the same direction d of the eyebolts (18).

6. Mechanical connector (10) according to one or more of the preceding claims, wherein the mechanical connector (10) encloses a service volume (36), comprised within the two secondary plates (14, 16), the two hook plates (22) and the central plate (12), wherein the service volume (36) is filled up with fireproof and / or insulating material.

7. Prefabricated unit (28) for the exterior covering of a building (30), comprising a mechanical connector (10) according to one or more of the preceding claims and a multilayer module (38), wherein the multi-layer module (38) comprises a structural frame (40) and one or more panels (42) side by side with each other.

8. Prefabricated unit (28) according to the preceding claim, wherein the structural frame (40) comprises a peripheral groove within which the two constraint plates (20) are received, each on one side.

9. Method for installing prefabricated units (28) for the exterior covering of a building (30), comprising the preliminary steps of:- providing a building (30);- providing on the outer surface of the building (30), in positions pre-defined in a design step, a plurality of brackets (44) comprising eyelets (46);- providing a plurality of prefabricated units (28) according to claim 7 or 8; wherein the method further comprises the iterative steps of:- lifting a prefabricated unit (28) and bringing it at the brackets (44) provided for receiving it in the design position;- inserting the bayonets (24) of the mechanical connector (10) into the eyelets (46) of the brackets (44);- releasing the prefabricated unit (28) in the design position.

10. Method according to the preceding claim, wherein the prefabricated units (28) are manufactured in a production facility remote from the building site.

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