The present invention relates to a modular constructional system for the construction of accommodations and other temporary buildings suitable for various services, such as community spaces, schools, warehouses, field kitchens, sanitary facilities, etc. , in emergency situations such as earthquakes, floods or other natural disasters .

In such emergency situations, one of the priorities is in fact the supply and the installation, in a quick and easy manner, of temporary housing and service modules that enable both the affected populations and the rescuers to cope with and manage the adverse situation in the most effective way possible, pending definitive long-term solutions.

The emergency solutions usually used normally involve the construction of tent camps, which, although they are quick to set up, are unable to offer a satisfactory level of habitability and comfort, both in terms of protection against adverse weather events, and in terms of provision of accessory services, especially in the event of a prolonged stay for those affected by the disaster. Therefore, in the event of a prolonged stay, it usually becomes necessary to transfer the affected persons successively into specially built temporary houses .

A solution that can offer a higher level of comfort than tents, both in terms of thermal and acoustic insulation and of privacy for the occupants, is given by the containers adapted as housing units. The contain- ers, however, are much more expensive than tents and, due to their considerable weight, require the use of trucks and cranes to be transported and installed, and if the disaster area is difficult to access, setting up camps made up of such structures can also prove to be very difficult.

Solutions have also been devised, as described for example in the Italian patent application No. 102018000008277 by the same Applicant, which provide for the realization of temporary housing units thanks to the use of modular articulated frames and special panellings suitable for forming floor, walls and roof. These housing units offer the occupants a habitability similar to that of small prefabricated houses, since they are provided with a rigid and well insulated structure, a floor raised from the ground and a pitched roof capable of effectively countering rain and snow, and therefore allow people to stay even for prolonged periods with a decent level of comfort.

These housing units further have the advantage of being made with components that are easy to assemble, of limited weight and size, and are able, when in dismounted condition, to assume an extremely compact configuration and with a very limited overall dimension, which feature greatly facilitates their storage, transport and installation .

However, in the housing unit described in the aforesaid Italian patent application No. 102018000008277, the hinges that allow the mobility of the articulated frames are not structural elements capable of contributing to the stability of and to maintaining the structure in the mounted position and, therefore, special brackets are necessary for stiffening and maintaining each frame in an operative position with respect to the housing unit itself and with respect to the adjacent frames .

Furthermore, the elements making up said articulated frames have a rigid structure of preset dimensions and therefore, once arranged in an operative position, it is not possible to vary either the height of the side walls of the housing unit, or the height and the inclination of the roof sides.

This clearly constitutes a dimensional constraint for the final layout of the housing unit.

Furthermore, since for obvious reasons of habitability the modules must have a minimum height to be respected (usually not less than 2 metres at the side walls and 2.80 metres at the roof ridge) , once the articulated frames are placed in the operative position, the mutual fixing of the elements forming the roof structure, as well as the positioning and fixing of the panelling that will make up the closure of the roof itself, necessarily require the use of ladders to allow workers to work at this height.

The general aim of the present invention is to overcome the aforesaid drawbacks by providing a modular constructional system for the construction of temporary housing units for emergency situations, such as accommodations and other buildings suitable for various services, such as community spaces, schools, warehouses, field kitchens, sanitary facilities, etc. , based on modular articulated frames that combine lightness, reduced overall dimensions when in a folded or nonoperative position, ease of extension in an operative position for mounting the housing units, which allow mounting workers to assemble the various frames working at man's height without the need to use ladders, which guarantee a stable positioning in an operative configuration without the need for fixing or stiffening brackets, and which also allow for great flexibility of construction with regard to the height of the walls and the inclination of the roof sides with the same floor surface .

In view of this aim, according to the invention, it was contemplated to realize a modular constructional system for the construction of temporary housing units for emergency situations, made by assembling a plurality of modular articulated frames, each modular articulated frame being composed of a first frame element rectangular in shape, intended to assume, when in operative condition, a horizontal position at the base of the modular articulated frame to form part of the floor structure of the housing unit, of a second frame element rectangular in shape, hinged to the first frame element and intended to assume, when in operative condition, a substantially vertical position to form part of the side wall structure of the housing unit, and of a third frame element rectangular in shape, hinged to the second frame element and intended to assume, when in operative condition, an inclined position at the upper part of the modular articulated frame to form part of the pitched roof structure of the housing unit, each rectangular frame element having a pair of longitudinal bars oriented in the direction of extension of the modular articulated frame from a folded non-operat ive condition to an extended operative condition and a pair of crosspieces oriented orthogonally to said longitudinal bars, characterized in that the longitudinal bars of at least said third frame element are extensible in length and in that the connection hinges respectively between the first and second frame elements and between the second and third frame elements are structural hinges, adjustable to lock stably at a plurality of preset angular positions when the modular articulated frame is in extended operative condition.

According to the invention, a method for the construction of temporary housing units for emergency situations has also been realized, using such a modular constructional system, characterized in that it comprises the steps of: - providing a plurality of modular articulated frames, wherein each modular articulated frame is composed of a first frame element rectangular in shape, intended to assume, when in operative condition, a horizontal position at the base of the modular articulated frame to form part of the floor structure of the housing unit, of a second frame element rectangular in shape, hinged to the first frame element and intended to assume, when in operative condition, a substantially vertical position to form part of the side wall structure of the housing unit, and of a third frame element rectangular in shape, hinged to the second frame element and intended to assume, when in operative condition, an inclined position at the upper part of the modular articulated frame to form part of the pitched roof structure of the housing unit;

- arranging the modular articulated frames in opposing pairs to form modular portions of the housing unit to be built, side by side one another along the foreseen length of the housing unit;

- extending each modular articulated frame by lifting together the second frame element and the third frame element relative to the first frame element, through rotation of first connection hinges between the first frame element and the second frame element, until said second and third frame elements are brought to a vertical position;

- locking said first hinges at a rotation angle of 90° to keep the second frame elements in a vertical position;

- further lifting the third frame element of each modular articulated frame, through rotation of second connection hinges between the second frame element and the third frame element, up to a horizontal position where the third frame elements of the pair of articulated frames opposing to each other to form a modular portion of the housing unit are aligned and coplanar;

- while keeping the third frame elements in horizontal position, applying third hinges at the facing ends of said third frame elements and partially extending the longitudinal bars of the faced third frame elements to stably connect said third hinges thereto;

- lifting together the third frame elements of each pair of opposing articulated frames, through a further extension of the respective longitudinal bars and simultaneous opening rotation of the second hinges and closing rotation of the third hinges, until reaching the desired inclination for the roof sides;

- locking said second and third hinges to keep the third frame elements at the reached angle of inclina- tion;

- if increasing the height of the second frame elements in their vertical position is required, extending the respective longitudinal bars upwards;

- completing the housing unit with side wall panels on the second frame elements, with roof panels on the third frame elements and with frontal walls closing the front and rear sides of the housing unit.

To clarify the explanation of the innovative principles of the present invention and the advantages thereof with respect to the prior art, one possible illustrative embodiment applying such principles will be described below, with the aid of the attached drawings. In the drawings:

Fig. 1 represents a perspective view, in folded or nonoperative condition, of a modular articulated frame on which the modular constructional system according to the invention is based.

Fig. 2 shows some articulated frames like the one of Fig. 1, stacked in storage condition.

Fig. 3.1 shows a pair of articulated frames arranged faced each other to form a modular portion of the housing unit, still in folded condition at the beginning of the mounting step.

Figures 3.2 to 3.6 illustrate successive steps of extension of the pair of articulated frames of Fig. 3.1 during the mounting of the modular portion of the housing unit .

Figures 4.1 to 4.12 illustrate in sequence the mounting steps of a plurality of modular portions such as those of Figures 3.1 to 3.6, for the construction of the housing unit . Fig. 5 shows a modular articulated frame like the one of Fig. 1, in operative position with the extensible frame elements corresponding to the side wall and to the roof arranged in extended configuration.

Fig. 6 shows, in exploded view, a detail of the hinging between the frame element corresponding to the floor and the frame element corresponding to the side wall.

Fig. 7 shows, in exploded view, a detail of the hinging between the frame element corresponding to the side wall and the frame element corresponding to the roof side .

Fig. 8 shows, in exploded view, a detail of the hinging between the frame elements corresponding to the roof in two articulated frames mutually faced to form a modular portion of the housing unit.

Fig. 9 shows a hinge intended to realize the rotatable connection between the frame element corresponding to the side wall and the frame element corresponding to the roof side.

Fig. 10 shows the detail of a part of the hinge of Fig . 9.

Fig. 11 shows a hinge intended to realize the rotatable connection between the frame element corresponding to the floor and the frame element corresponding to the side wall .

Fig. 12 shows an example of a complete housing unit, made with the modular constructional system according to the invention.

The general term "housing unit" in this patent text is understood in an equivalent manner to mean both a building intended to constitute a temporary accommodation for people living there during an emergency situa- tion, and a building suitable for being used for various services, such as community spaces, schools, warehouses, field kitchens, sanitary facilities, etc. , during said emergency situation.

A housing unit realized with the modular constructional system according to the invention is shown, by way of example and indicated with the reference number 10, in Fig. 12.

For the sake of descriptive consistency, the same reference number 10 is also used in Figures 4.2 to 4.12 to identify said housing unit during the intermediate construction steps.

The housing unit 10 is made by assembling a plurality of modular articulated frames 11, as will be described in more detail below.

Fig. 1 shows a modular articulated frame 11 constituted by a first frame element 12 intended to assume, when in operative condition, a horizontal position at the base of the modular articulated frame 11 to form part of the bearing structure of the floor of the housing unit 10, by a second frame element 13, hinged to the first frame element 12 and intended to assume, when in operative condition, a substantially vertical position to form part of the bearing structure of the side walls of the housing unit 10, and by a third frame element 14, hinged to the second frame element 13 and intended to assume, when in operative condition, an inclined position at the upper part of the modular articulated frame 11 to form part of the bearing structure of the pitched roof of the housing unit 10.

The first frame element 12 is also arranged for application of a plurality of height-adjustable ground- resting feet 15, intended as will be seen below to keep the flooring of the housing unit 10 raised from the ground and in a perfectly horizontal position regardless of the presence of any slight irregularities of the ground surface on which the housing unit itself is installed .

Advantageously, the second frame element 13 and the third frame element 14 have, in their non-operat ive condition, shape and dimensions substantially similar to each other, but shorter length and width than the first frame element 12. In this way, as well visible for example in Figures 1 and 3.1, when the modular articulated frame 11 is folded in non-operat ive condition, the second frame element 13 and the third frame element 14 remain contained, superimposed on each other in a horizontal position, inside the contour of the first frame element 12, with evident optimization of the overall dimensions.

This also favours the stacking of the articulated frames 11 during the steps of storage, transport and preparation for assembly, as shown in Figures 3.1 and 4.1.

The first frame element 12 is generically rectangular in shape, with a first longitudinal bar 16 and a second longitudinal bar 17 being arranged respectively at the two longer sides of the rectangle, oriented in the direction of extension of the modular articulated frame 11 from a folded non-operat ive condition to an extended operative condition, and with a first crosspiece 18 and a second crosspiece 19 being arranged respectively at the two shorter sides of the rectangle, oriented orthogonally to the longitudinal bars. In particular, the first crosspiece 18 is intended to be located, when the modular articulated frame 11 is in the operative position, at the centreline of the floor of the housing unit 10, while the second crosspiece 19 is located at the hinging between the first frame element 12 and the second frame element 13.

The second frame element 13 in turn is generically rectangular in shape, with a first longitudinal bar 20 and a second longitudinal bar 21 being arranged respectively at the two longer sides of the rectangle, and with a first crosspiece 22 and a second crosspiece 23 being arranged respectively at the two shorter sides of the rectangle. As can be clearly seen, for example, in Fig. 5, the first crosspiece 22 is located at the hinging between the first frame element 12 and the second frame element 13 (thus adjacent to the second crosspiece 19 of the first frame element 12) , while the second crosspiece 23 is located at the hinging between the second frame element 13 and the third frame element 14. The third frame element 14 is also generically rectangular in shape (advantageously, as explained above, with dimensions similar to the second frame element 13) , with a first longitudinal bar 24 and a second longitudinal bar 25 being arranged respectively at the two longer sides of the rectangle and with a first crosspiece 26 and a second crosspiece 27 being arranged respectively at the two shorter sides of the rectangle. The first crosspiece 26 is located at the hinging between the second frame element 13 and the third frame element 14 (thus adjacent to the second crosspiece 23 of the second frame element 13) , while the second crosspiece 27 is intended to be located, when the modu- lar articulated frame 11 is m operative position, at the roof ridge.

The longitudinal bars 16, 17, 20, 21, 24, 25 of the three frame elements 12, 13, 14 are advantageously made of tubular profiles, both for reasons of reduction of the overall weight of the structure and for operative reasons as will be better explained below.

The mutual rotation between the first frame element 12 and the second frame element 13 is ensured by a pair of first hinges 28, 28 ' connecting the two frame elements 12, 13 together, advantageously at the respective first longitudinal bars 16, 20 and at the respective second longitudinal bars 17, 21, as shown schematically in the exploded view of Fig. 6.

The hinge 28 is constituted by two wings 29, 30, adapted to couple respectively with the first longitudinal bar 16 of the first frame element 12 and with the first longitudinal bar 20 of the second frame element 13 (advantageously inserting within the respective tubular profiles) , and by a central hinging portion or pin 31, adapted to define the axis around which said wings 29, 30 can mutually rotate.

Similarly, the hinge 28 ' is constituted by two wings 29' , 30 ' , adapted to couple respectively with the second longitudinal bar 17 of the first frame element 12 and with the second longitudinal bar 21 of the second frame element 13 (also inserting within the respective tubular profiles) , and by a central hinging portion or pin 31 ' , adapted to define the axis around which said wings 29' , 30 ' can mutually rotate.

The two central hinging pins 31, 31 ' together identify the mutual axis of rotation of the two frame elements 12, 13.

Since, as explained above, the second frame element 13 is smaller in size than the first frame element 12 in order to be able to be accommodated within the latter when the modular articulated frame 11 is folded in nonoperative condition, the two wings 29, 30 of the hinge 28 (as well as the two wings 29' , 30 ' of the hinge 28 ' ) are not coplanar, but offset in a manner corresponding to the distance between the axes of the tubular profiles constituting the pairs of longitudinal bars 16, 20 and 17, 21 of the frame elements 12, 13. A detail of such a hinge configuration is shown in Fig. 11.

The mutual rotation between the second frame element 13 and the third frame element 14 is ensured by a pair of second hinges 32, 32 ' connecting the two frame elements 13, 14 together, advantageously at the respective first longitudinal bars 20, 24 and at the respective second longitudinal bars 21, 25, as shown schematically in the exploded view of Fig. 7.

The hinge 32 is constituted by two wings 33, 34, adapted to couple respectively with the first longitudinal bar 20 of the second frame element 13 and with the first longitudinal bar 24 of the third frame element 14 (advantageously inserting within the respective tubular profiles) , and by a central hinging portion or pin 35, adapted to define the axis around which said wings 33, 34 can mutually rotate.

Similarly, the hinge 32 ' is constituted by two wings 33' , 34 ' , adapted to couple respectively with the second longitudinal bar 21 of the second frame element 13 and with the second longitudinal bar 25 of the third frame element 14 (also inserting within the respective tubular profiles) , and by a central hinging portion or pin 35' , adapted to define the axis around which said wings 33' , 34 ' can mutually rotate.

The two central hinging pins 35, 35' together identify the mutual axis of rotation of the two frame elements 13, 14.

Since, as explained above, the second frame element 13 and the third frame element 14 have the same width in order to be able to superimpose on each other with the respective longitudinal bars when the modular articulated frame 11 is folded in non-operat ive condition, the two wings 33, 34 of the hinge 32 (as well as the two wings 33' , 34 ' of the hinge 32 ' ) are arranged coplanar with each other. A detail of such a hinge configuration is shown in Fig. 9.

The third frame element 14 is arranged to receive, at its second crosspiece 27 (i.e. the portion of the modular articulated frame 11 intended to be located, when in operative position, at the roof ridge) , a pair of third hinges 36, 36' connecting together the third frame elements 14 of two modular articulated frames 11 mutually faced to form a modular portion of the housing unit, advantageously at the respective first longitudinal bars 24, 24 and at the respective second longitudinal bars 25, 25, as shown schematically in the exploded view of Fig . 8.

The hinge 36 is constituted by two wings 37, 38, adapted to couple respectively with the first longitudinal bar 24 of one of the two frame elements 14 mutually faced and with the first longitudinal bar 24 of the other of the two frame elements 14 mutually faced (advantageously inserting within the respective tubular profiles) , and by a central hinging portion or pm 39, adapted to define the axis around which said wings 37, 38 can mutually rotate.

Similarly, the hinge 36' is constituted by two wings 37 ' , 38 ' , adapted to couple respectively with the second longitudinal bar 25 of one of the two frame elements 14 mutually faced and with the second longitudinal bar 25 of the other of the two frame elements 14 mutually faced (also inserting within the respective tubular profiles) , and by a central hinging portion or pin 39' , adapted to define the axis around which said wings 37 ' , 38 ' can mutually rotate.

The two central hinging pins 39, 39' together identify the mutual axis of rotation of the two mutually faced frame elements 14.

Since the two mutually faced frame elements 14 obviously have the same width, the two wings 37, 38 of the hinge 36 (as well as the two wings 37 ' , 38 ' of the hinge 36' ) are arranged coplanar with each other.

Advantageously, the hinges 36, 36' intended to be arranged between the two frame elements 14 mutually faced at the roof ridge can be identical to the hinges 32, 32 ' intended to be arranged between the second frame element 13 and the third frame element 14 at the hinging between the side wall and the roof side, so as to optimize the production, storage and transport of the components of the housing unit.

The hinges 28, 28 ' , 32, 32 ' , 36, 36' that achieve the mutual mobility of the frame elements 12, 13, 14 that make up the modular articulated frame (as well as the mutual mobility of the two frame elements 14 mutually faced to form the bearing structure of the pitched roof of the housing unit) are so-called "structural" hinges, i.e. hinges that allow the stable fixing of the desired rotation angle between the frame elements connected by them, so as to permanently maintain the structure of the housing unit in the design configuration without the need to use special angular brackets with predetermined shape as it was the case in the structure described in the aforesaid Italian patent application No. 102018000008277 .

For this purpose, the hinges may for example be of the so-called "Hirth joint" type, wherein the central hinging portions 31, 31 ' , 35, 35' , 39, 39' consist of two halves each having a frontal toothed crown 40 adapted to engage the frontal toothed crown of the other half, as shown in detail in Figures 9, 10 and 11.

The adjustment of the angular position of the hinges takes place by loosening the tightening screws 41 so as to be able to move the two toothed crowns 40 away from each other and to rotate them to the desired angle, then engaging them again in the chosen angular position and definitively tightening the screws 41.

The number of teeth of the crown defines a plurality of preset angular positions for stable locking of the adjustable hinge.

With regard to the hinging between the first frame element 12 and the second frame element 13, for the purpose of reducing the overall dimensions to favour the kinematic motion of mutual mobility of the two elements starting from the folded non-operat ive condition, it was found particularly advantageous to realize the two hinges 28, 28 ' with the respective central portions 31, 31 ' connected to each other by a bar which, once the hinges themselves are mounted with the respective wings 29, 29' inserted inside the tubular profiles of the longitudinal bars 16, 17 of the first frame element 12, constitutes de facto the second crosspiece 19 of said frame element, as visible in Fig. 6.

The longitudinal bars 20, 21 and 24, 25 of the second and respectively of the third frame element 13, 14 are extensible in length, so as to be able to vary the length of said rectangular frame elements as required. In particular, the extensibility of the longitudinal bars 20, 21 of the second frame element 13 makes it possible to adjust the height of the side walls of the housing unit .

The extensibility of the longitudinal bars 24, 25 of the third frame element 14, together with the adjustability of the angular position of the hinges 32, 32 ' , on the other hand, allows to adjust the height and the inclination of the roof sides of the housing unit.

Said longitudinal bars 20, 21 and 24, 25 are advantageously made with a telescopically extensible tubular structure. Appropriate locking means (not shown in detail in the figures) can of course be provided for keeping the telescopic elements in the desired extended position .

The steps for mounting a housing unit according to the invention, made with a plurality of modular articulated frames 11 having the geometric and structural characteristics described above, will now be briefly illustrated .

With reference to Fig. 4.1, there is provided a plurality of modular articulated frames 11, the total number of which depends on the dimensions envisaged for the housing unit 10, together with a plurality of height- adjustable resting feet 15 intended to maintain the flooring of the housing unit raised from the ground and in a perfectly horizontal position regardless of the presence of any slight irregularities of the ground surface on which the housing unit itself is installed. The modular articulated frames 11 are positioned, on the resting feet 15, in pairs of articulated frames faced each other to form a modular portion 50 of the housing unit to be built, as shown in greater detail in Fig. 3.1.

Several modular portions 50 will be placed side by side one another, as shown in Fig. 4.2, until the length envisaged for the housing unit 10 is reached.

The modular articulated frames 11 can be fixed on the resting feet 15 previously arranged on the ground in suitable number and position, as schematically indicated in Fig. 4.1, or the resting feet 15 can be firstly fixed to the frame element 12 of each modular articulated frame 11 and then the various modular articulated frames 11 provided with feet 15 can be arranged on the ground until obtaining the arrangement of Fig. 4.2. After making the first frame elements 12 of each modular articulated frame 11 integral with each other (with suitable fixing means, such as bolts or other) to give solidity and stability to the base of the structure, each modular articulated frame 11 is extended by lifting together the second frame element 13 and the third frame element 14 relative to the first frame element 12, through rotation of the first hinges 28, 28 ' , until they are brought to a vertical position as shown in Fig. 3.2. In this figure (as well as in some subsequent figures) the intermediate positions of the movable elements during their movement between the initial position and the final position of the illustrated sequence are shown in a dashed line.

Figures 4.3 and 4.4 illustrate this step of extending all modular articulated frames 11 to bring the respective second and third frame elements 13, 14 to a vertical position.

In this condition, after locking the hinges 28, 28 ' at a rotation angle equal to 90°, the second frame elements 13 are in a (vertical) position suitable for forming part of the side wall structure of the housing unit 10.

Preferably in this step, the second frame elements 13 of each modular articulated frame 11 are made integral with each other (with suitable fixing means, such as bolts or other) to give solidity and stability to the side wall structure of the housing unit.

Starting from this condition, the third frame element 14 is further lifted, through rotation of the second hinges 32, 32 ' , until it assumes the horizontal position shown in Fig. 3.3, where the third frame elements 14 of the pair of articulated frames 11 mutually faced to form a modular portion 50 of the housing unit are aligned and coplanar.

Figures 4.5 and 4.6 illustrate this step of further lifting all the third frame elements 14 up to the aforesaid horizontal position.

At this point, appropriate floor panels 42 may be applied on the first frame elements 12 of the modular articulated frames 11, as shown in Fig. 3.4 for the single modular portion 50 and in Fig. 4.7 for the entire structure of the housing unit 10, so that mounting workers can work comfortably and under safety conditions in the structure being assembled.

Of course, the floor panels 42 may be mounted also in previous steps, for example after bringing the second and third frame elements 13, 14 together to a vertical position, prior to further lifting the third frame elements 14.

While keeping the third frame elements 14 in horizontal position, it is therefore possible to apply the third hinges 36, 36' at the facing ends of said third frame elements 14, as visible in Fig. 3.4 for the single modular portion 50 and in Fig. 4.8 for the entire structure of the housing unit 10.

In particular, the hinges 36, 36' are made integral with the two facing modular articulated frames 11 by inserting their wings 37, 38, 37 ' , 38 ' within the tubular profiles of the longitudinal bars 24, 25 of the respective third frame elements 14, which insertion takes place by carrying out a first step of telescopic lengthening of said longitudinal bars 24, 25 as shown in Fig. 4.9, where the respective lengthening portions 24a, 25a are visible.

At this point, each modular portion 50 is stably formed by the respective pair of modular articulated frames 11 mutually faced and connected by the hinges 36, 36' arranged at the portion intended to form the roof ridge. It is therefore easy for the operators, working at man's height on the floor 42 covering the first frame elements 12, to lift together the pair of third frame elements 14 as visible in Fig. 3.5, by further telescopic lengthening of the longitudinal bars 24, 25 (see m the figure the corresponding extension of the respective lengthening portions 24a, 25a) and simultaneous opening rotation of the second hinges 32, 32 ' and closing opening of the third hinges 36, 36' , until reaching the desired inclination of the roof sides.

In this step, in practice, the roof ridge (i.e. the area of the third hinges 36, 36' ) is lifted, while maintaining instead the second hinges 32, 32 ' at the upper end of the walls at the same height.

Figures 4.10 and 4.11 illustrate this step of further lifting all the third frame elements 14 until the desired inclination of the roof sides of the housing unit 10 is reached.

At this point, after having locked the hinges 32, 32 ' and 36, 36' in the rotation angles corresponding to the position reached, also the third frame elements 14 of each modular articulated frame 11 can be made integral with each other (with appropriate fixing means, such as bolts or other) to give solidity and stability to the roof structure of the housing unit.

Should the height of the side wall structure constituted by the second frame elements 13 be less than the design height of the housing unit, it is possible to further proceed to the telescopic lengthening of the longitudinal bars 20, 21 (as shown in Fig. 3.6, where the respective lengthening portions 20a, 21a) are visible, while maintaining the inclination of the roof sides unchanged (i.e. of the third frame elements 14, which thus simply translate upwards) , until reaching the desired height for the side walls of the housing unit 10. Fig. 4.12 shows the structure of the housing unit 10 with all the modular portions 50 in the final configu- ration of Fig. 3.6.

At this point, the structure of the housing unit 10 can be completed, by closing with suitable profiles the spaces that may exist between the longitudinal bars of the adjacent frame elements at the side walls and at the roof sides (since, as we have seen, said frame elements 13, 14 have a width less than the first frame element 12 in order to be able to be inserted at least partially within the latter when the modular articulated frame 11 is folded in non-operat ive condition) , by applying side wall panels 43 on the second frame elements 13, roof panels 44 on the third frame elements 14, as well as frontal walls 45 closing the front and rear sides of the housing unit, provided with doors and windows according to the design, as schematically illustrated in Fig. 12. Of course, suitable doors and windows can be provided also at the side walls of the housing unit .

Roof and side walls will then be advantageously covered by an external coating tarpaulin 46 (shown only partially in Fig. 12) for adequate protection against weather agents.

Thanks to the frame structure 11, for the floor, for the side walls and for the roof, highly thick insulated panels can be used, practically up to the thickness of the bars and of the crosspieces of the frames themselves, thus guaranteeing thermal, hygienic and habitability conditions comparable to those of a traditional prefabricated building.

It is clear at this point how the modular constructional system for the construction of housing units according to the invention makes it possible to achieve the set objectives. In fact, said modular constructional system combines lightness and reduced overall dimensions of the articulated frames when they are in folded or non-operat ive position, ease of mounting that allows operators to assemble the various frames working at man's height without the need to use ladders, and a considerable rigidity and stability of the structure without the need for special stiffening brackets to keep the structure in the envisaged shape, apart from the use of normal means for mutual connection among adjacent modules, such as bolts or the like.

Furthermore, the extensibility of the longitudinal bars of the frame elements guarantees a high flexibility with regard to the shape and to the dimensions of the structure: in fact, by playing on the values of the telescopic extensions of the side wall frames and of the roof frames, as well as on the lockability of the hinges at a plurality of preset angular positions, it is possible, with the same modular articulated frame, to realize housing units with walls of different height with the same width of the structure and height and inclination of the roof, or different heights and inclinations of the roof with the same width of the structure and height of the walls, or a combination of both. Moreover, thanks to the extensibility of said second and third frame elements 13, 14, it would also be possible, if necessary, to realize an asymmetrical structure simply by adopting different lengthenings of the frames and different angles of the hinges on the two sides of the housing unit 10.

Clearly, the above description of an embodiment applying the innovative principles of the present invention is given by way of an illustrative example of such innovative principles and must not, therefore, be taken to limit the scope of the patent claimed herein.

For example, instead of making both the second and third frame elements 13, 14 extensible, just only one of them could be extensible: with only the second frame element 13 being telescopically extensible and the third frame element 14 with fixed geometry, it is possible to make structures with roof having fixed inclination and height-varying side walls; conversely, with only the third frame element 14 being telescopically extensible and the second frame element 13 with fixed geometry, it is possible to make structures with side walls having fixed height and with a roof having a different height of the ridge and inclination of the pitches .

Furthermore, the mutual fixing of adjacent frame elements in the plurality of side-by-side modular portions 50 can be carried out at different constructional steps compared to what described above by way of example, if this is considered more appropriate for an optimal execution of the construction site activity.

Finally, it is obvious to the person skilled in the art that "substantially vertical" arrangement of the side walls (and therefore of the second frame elements 13 of the modular articulated frames 11) can also be understood to mean configurations that are not exactly equal to 90° with respect to the ground, but also with slight inclinations that are in any case close to this value, should this be deemed necessary for special design requirements .