WO2015107509A1

WO2015107509A1 - Improved coupling system for connecting one or more movable walls to a fixed structure

Info

Publication number: WO2015107509A1
Application number: PCT/IB2015/050424
Authority: WO
Inventors: Alberto Stella
Original assignee: Estel Furniture S.R.L. Con Socio Unico
Priority date: 2014-01-20
Filing date: 2015-01-20
Publication date: 2015-07-23

Abstract

The invention is a coupling system (1, 100) for coupling a movable wall (P) with a fixed structure (S), of the type comprising: a first structural element (2) configured so as to be fixedly coupled with the fixed structure (S); a second structural element (5) provided with coupling means (6) for the movable wall (P); a plurality of guide means (7) slidingly coupled with the second structural element (5) to allow the movement of the second structural element (5) from a first position of minimum distance from the first structural element (2) to a second position of maximum distance from the first structural element (2) and vice versa; elastic means (8) arranged between the first structural element (2) and the second structural element (5). Said elastic means (8) are configured in such a way as to exert two opposite thrusting forces towards the two structural elements (2, 5) when the distance between them is smaller than said maximum distance.

Description

IMPROVED COUPLING SYSTEM FOR CONNECTING ONE OR MORE

MOVABLE WALLS TO A FIXED STRUCTURE.

DESCRIPTION

The invention concerns an improved coupling system suited to allow the connection of one or more movable walls to a fixed structure.

As is known, at present systems that consist of "movable walls" coupled with so-called "fixed" structures, like ceilings, bearing walls or floors through the use of suitable coupling systems are used to rationally divide working spaces inside a building.

As is known, the term "movable walls" is used in technical jargon to indicate substantially plate-like partition elements that are usually rectangular in shape and have their long sides slightly shorter than the height of the room in which they must be located. These partition elements or movable walls can be made of an opaque material, like for example wood, or a transparent material, like glass.

As mentioned above, said movable walls are positioned side by side based on the geometry of the work spaces to be obtained and each one of them is removably fixed to at least two fixed structures, for example the ceiling and the floor of a building, using precisely two coupling systems. Advantageously, the fact that the movable walls are removably coupled with the fixed structures makes it possible to quickly vary their arrangement in case different needs related to the subdivision of the work spaces should arise.

As regards said coupling systems, a first type of such systems A1 is known in the market, which is constituted by a single section element B with substantially longitudinal development, as can be observed in Figures 1 and 2 illustrating the known art, configured so that it can be fixed in a stable manner to a fixed structure S, for example to the ceiling S of a building, and removably coupled with a movable wall P.

However, the static coupling that is obtained between the movable wall P and each fixed structure S through the use of said first type of coupling system A1 determines an important drawback if any anomalous event takes place, such as an earthquake with vertical shocks, or in any case, in general, a relative displacement in the vertical direction of the fixed structures S between which the movable wall P is interposed.

In these circumstances, in practice, there is a temporary variation in the distance between said fixed structures S in the vertical direction. To disadvantage, the inability of said first type of coupling system A1 of the known art to attenuate and thus neutralize the effects of said variation on the movable wall P causes considerable stress to be applied to the same movable wall P interposed therebetween. In particular, at the moment when the distance between said two fixed structures S is reduced, the movable wall P is subjected to a compression action that may cause its structural collapse. In the opposite case, that is, when the vertical distance between said two fixed structures S increases, there is the risk of the end of the movable wall P being torn by the coupling means E defined in the coupling system A1 , causing the same movable wall P to collapse in the work space, with possible damage to property or objects.

A second type of coupling system A2 has been developed in order to avoid said drawback and comprises a first and a second section element B1 and B2, both having C-shaped cross section defined by a centre wall, respectively C1 and C2, with two parallel side walls C3 and C4 developing from their ends. In particular, as can be observed in Figure 3 illustrating the known art, the first section element B1 is configured so that it can be fixed to a fixed structure S at the level of the outer surface D1 of its centre wall C1 , while the second section element B2 is provided, at the level of the outer surface D2 of the corresponding centre wall C2, with coupling means E for coupling it with the movable walls P. The first and the second section element B1 and B2 are configured in such a way that in cross section the width of the second section element B2 substantially coincides with the distance between the inner surfaces of the side walls C3 and C4 of the first section element B1 , as shown in Figure 3 illustrating the known art. This configuration makes it possible to obtain a coupling through interference between said two section elements B1 and B2.

In the case where, for any reason, a variation should occur in the distance between the fixed structures S between which a movable wall P is interposed and with which it is coupled, the relative displacement in the vertical direction between the two section elements B1 and B2 of the same coupling system A2 makes it possible to attenuate said variation, therefore avoiding a compression of the movable wall P or, in the opposite case, preventing it from being torn and moved away from the coupling means E of the corresponding coupling system A2.

However, to disadvantage, also this second type of coupling systems A2 poses a considerable drawback due to the risk, which is not remote, of a friction force being generated between said two section elements B1 and B2, wherein said friction force would be such as to prevent any relative displacement between them or, at least, to determine a jerking movement between said two section elements B1 and B2. In other words, there is the risk that for any reason, owing to time and wear, said two section elements B1 and B2 may get seized and consequently bring about the problems described above and observed in the first type of coupling systems.

As described in the prior art documents US 4 103 463 and US 4 037 380, in order to overcome the last drawback mentioned above the interposition of elastic means between the two structural elements B1 and B2 has been devised. These elastic means are configured so as to exert two opposite thrusting forces towards the same structural elements. Document US 4 103 463 furthermore describes the presence of guide means suited to allow the controlled sliding movement of a first structural element B1 with respect to the second structural element B2.

The present invention intends to overcome the drawbacks described above. In particular, it is the object of the present invention to provide a coupling system that is capable of effectively attenuating and neutralizing the effects of the possible variation in the distance between the fixed structures having a wall of the movable type interposed therebetween and coupled with them.

In greater detail, the coupling system that is the subject of the invention is capable of attenuating the variation in the distance between the fixed structures both when this occurs once in a while, for example when a load that is larger than that present in normal conditions is applied to the ceiling on which said coupling system is installed, and when variations in said distance occur repeatedly, for example in the case of the vertical shocks caused by an earthquake. Furthermore, the coupling system of the invention is capable of attenuating said variation in the distance both of the temporary type, that is, when at the end of the event that caused said variation the initial conditions are restored, and of the permanent type, when for example the larger load applied to the ceiling is not removed.

A further object of the invention is to provide a coupling system that is capable of operating correctly for a long time, with no risk of seizures or jams due to wear.

The objects described above are achieved by the coupling system whose characteristics are in accordance with the main claim.

In particular, the coupling system of the invention is characterized in that the coupling between the first and the second structural element is carried out through a plurality of guide means on which said second structural element can slide and through elastic means interposed between said two structural elements and suited to exert two opposite thrusting forces on the same two structural elements.

Furthermore, the special configuration of the coupling system of the invention, whose characteristics are described in claim 1 , makes it possible to facilitate the related operation of fixing it inside a housing obtained in the ceiling, or to any other fixed structure of a building, with no need to use external fixing elements, like for example screws and dowels.

The objects and advantages described above are highlighted in greater detail in the description of two preferred embodiments of the invention, which are illustrated here below by way of non-limiting examples with reference to the attached drawings, wherein:

- Figure 1 shows a front sectional view of a first type of coupling system for coupling a fixed structure with a movable wall, belonging to the known art;

- Figure 2 shows an axonometric view of the coupling system of the known art illustrated in Figure 1 ;

- Figure 3 shows a front sectional view of a second type of coupling system for coupling a fixed structure with a movable wall, belonging to the known art;

- Figure 4a shows an axonometric section plane view of the coupling system of the invention according to a first preferred embodiment;

- Figure 4b shows an axonometric view of the coupling system of the invention according to an alternative embodiment to said first preferred embodiment illustrated in Figure 4a;

- Figure 5 shows a front view of the coupling system of Figure 4a in the configuration of minimum distance between the first and the second structural element;

- Figure 6 shows a front view of the coupling system of Figure 4a in the configuration of maximum distance between the first and the second structural element;

- Figure 7 shows an axonometric section plane view of the coupling system of the invention according to a second preferred embodiment of the invention; - Figure 8 shows a front view of the coupling system of Figure 7 in the configuration of maximum distance between the first and the second structural element;

- Figure 9 shows a sectional view of the coupling system of Figure 8, in which the expansion unit is highlighted;

- Figure 10 shows a detail of the expansion unit shown in Figure 9;

- Figure 1 1 shows a front view of the coupling system of Figure 7 in the normal operating condition, in which the second structural element is arranged in an intermediate position between the position of maximum distance and the position of minimum distance with respect to the first structural element.

The coupling system of the invention, suited to provide connection between at least one movable wall P and a fixed structure S, is represented in a first preferred embodiment in Figures from 4a to 6, where it is indicated as a whole by 1 , and in a second preferred embodiment in Figures from 7 to 1 1 , where it is indicated as a whole by 100.

As regards the first embodiment, the coupling system 1 of the invention, as shown in Figures 4a, 5 and 6, comprises a first structural element 2 with substantially longitudinal development, configured in such a way that it can be securely connected to the fixed structure S, like for example the ceiling S of a building. Preferably but not necessarily, as shown in Figures 5 and 6, the first structural element 2 comprises a section element 21 with C-shaped cross section. Said C-shaped cross section is defined by a centre wall 3 at the ends 31 of which there are two side walls 4 that develop substantially parallel to each other.

According to an alternative variant embodiment of the coupling system 1 described up to now, the first structural element 2 may comprise two section elements 17 and 18, each one of which has L-shaped cross section, as shown in Figure 4b. Said L-shaped cross section is defined by a first wall 3, which by analogy with the preferred embodiment of the invention is indicated here below as centre wall 3, and by a second wall 4 that develops starting from an end 31 of said centre wall 3. As regards said second wall 4, by analogy with the preferred embodiment of the invention described herein, too, it is defined as side wall 4.

Furthermore, it cannot be excluded that in alternative embodiments of the invention said first structural element 2 may comprise exclusively the centre wall 3 or have a different cross section.

Going back to the preferred embodiment described herein, as can be observed in Figures 5 and 6 the first structural element 2 is suited to be fixed to said ceiling S at the level of its centre wall 3 through external fixing elements F, like for example screws and dowels.

It cannot be excluded, however, that in different embodiments of the coupling system 1 of the invention said first structural element 2 can be provided with its own fixing means so that it can be fixed to said ceiling S, as will be clarified below in the description of the second preferred embodiment of the coupling system 100 of the invention.

The coupling system 1 of the invention furthermore comprises a second structural element 5 with substantially longitudinal development, as can be seen in Figure 4a, spaced from said first structural element 2 and provided with coupling means 6 suited to allow the connection of one or more movable walls P.

In particular, as regards said coupling means 6, according to said first preferred embodiment they comprise a housing 61 defined at the level of the outer surface 51 of the second structural element 5, opposite the centre wall 3 of the first structural element 2. Said housing 61 is configured in such a way as to house and lock an end P1 of a movable wall P, if necessary through the use of gaskets not illustrated in the figures.

It cannot be excluded, however, that in alternative embodiments to said first preferred embodiment several housings 61 , positioned side by side, can be defined in the second structural element 5, in such a way as to make it possible to arrange several movable walls P of different types in sequence. According to the invention, as shown in Figure 4a, the coupling system 1 is provided with a plurality of guide means 7 that extends starting from the inner surface 32 of the centre wall 3 of said first structural element 2, in such a way as to define a single sliding direction, indicated by X in Figures 5 and 6, substantially parallel to the side walls 4 of the same first structural element 2. As shown in Figure 4b, in the case of said variant embodiment, according to which the first structural element 2 comprises two section elements 17 and 18, said guide means 7 extend from the inner surface 32 of the centre wall 3 of both of the section elements 17 and 18.

The second structural elements 5 is slidingly coupled with said plurality of guide means 7 in such a way as to allow its relative displacement with respect to the first structural element 2 along said sliding direction X from a first position of minimum distance between the two structural elements 2 and 5, as shown in Figure 5, to a second position of maximum distance between them, as shown in Figure 6. The relative displacement between the two structural elements 2 and 5 can take place also in the opposite direction, meaning from said second position to the first position.

In greater detail, according to the preferred embodiment of the invention described herein, the plurality of guide means 7 comprises a plurality of rods 71 , each one of which is provided with a stop element 72 at the level of its free end. In its turn, the second structural element 5 is provided with a plurality of holes 52, each one of which is suited to house one of said rods 71 in such a way as to allow, in fact, the movement of the same second structural element 5 along the sliding direction X from said first position to the second position. In greater detail, said second position, as shown in Figure 6, is defined at the level of the stop elements 72 of the rods 71. Preferably but not necessarily, as shown in Figure 4a, the first structural element 2 comprises four rods 71 , arranged in pairs in proximity to one of the two side walls 4.

It cannot be excluded, however, that in different embodiments of the coupling system 1 of the invention the first and the second structural element 2 and 5 may develop longitudinally to a greater extent compared to the preferred embodiment described herein. In this case, there are more than four rods 71 that are located, spaced from each other, along the entire length of the first structural element 2 and, consequently, said holes 52 are made, spaced from each other, along the entire length of the second structural element 5.

Finally, according to the first preferred embodiment described herein, the coupling system 1 of the invention comprises elastic means 8 interposed between the first and the second structural elements 2 and 5.

Said elastic means 8 are configured in such a way that they are in a condition of compression when the distance between the first and the second structural elements 2 and 5 is smaller than the maximum distance defined by said second position.

In said condition of compression, each one of the elastic means 8 exerts two opposite thrusting forces towards the two structural elements 2 and 5, in such a way as to force them to move away from each other.

The advantages related to the presence of said elastic means 8 interposed between the first and the second structural elements 2 and 5 are clarified here below during the description regarding the operation of the coupling system 1 of the invention.

As regards, in particular, said elastic means 8, according to the preferred embodiment of the invention described herein and as shown in Figures from 4a to 6, they comprise a plurality of helical springs 81 , each one of which is fitted coaxially on one of the rods 71 , between the first and the second structural element 2 and 5.

It cannot be excluded, however, that in variants of said first embodiment of the invention said elastic means 8 may be of a different type, provided that they can serve the same function.

In some situations, in order to prevent a coupling system suited to connect a fixed structure S to a movable wall P from being visible from the outside, a housing U, suited to at least partially accommodate said coupling system, is created in said fixed structure S.

However, in these situations the operation of fixing the coupling system to the fixed structure S is more complicated, as the freedom of manoeuvre is reduced.

In particular, it is difficult to fix the coupling system 1 of the invention with screws and dowels at the level of its centre wall 3, as said centre wall 3 is arranged inside said housing U.

In this regard, in order to overcome said further problem, the second embodiment of the coupling system 100 of the invention which, as explained above, is shown in Figures from 7 to 1 1 , is proposed here below.

In particular, as can be observed in the figures, the coupling system 100 has the first element 2 provided with said two section elements 17 and 18 with L-shaped cross section.

It cannot be excluded, however, that in a variant embodiment of said coupling system 100 the first element 2 may comprise the section element 21 with C-shaped cross section described above with reference to the first preferred embodiment of the invention.

Furthermore, the coupling system 100, as shown in Figure 8, in addition to having all the characteristics previously described for the first embodiment of the coupling system 1 of the invention, is provided with an expansion unit 9 suited to facilitate said fixing operation.

In particular, said expansion unit 9, shown in detail in Figure 9, advantageously makes it possible to avoid the use of external fixing elements, for example screws and dowels, and consequently avoids the need to previously make holes in the fixed structure S in order to introduce and lock said fixing elements therein.

As can be observed in Figure 9, said expansion unit 9 is housed in the second structural element 5. According to the invention, the expansion unit 9 is configured in such a way that it exerts two thrusting forces N in opposite directions against the inner surfaces 41 of the two side walls 4 of the first structural element 2.

In this way, said two walls 4 are mutually spaced according to the direction that is substantially parallel to the plane of development of the second structural element 5 and orthogonal to the longitudinal axis of the same. In turn, said two walls 4 exert a thrusting force in opposite directions on each one of the side walls L of the housing U. Said series of events consequently determines a coupling through interference between the coupling system 100 and the fixed structure S.

In even greater detail, according to the preferred embodiment of the invention described herein and as shown in Figure 9, in order to generate said thrusting forces in opposite directions the expansion unit 9 comprises, in proximity to each one of the two side walls 4 of the first structural element 2, a thrust actuator 10 provided with a cylinder 11 that supports an expandable rod 12. Said two thrust actuators 10 are fixedly arranged on two plates 13 belonging to the second structural element 5 and slidingly coupled with the centre body 14 of the same second structural element 5, in such a way as to define a direction of relative displacement of said plates 13 with respect to the centre body 14. In particular, said sliding coupling defines a direction of displacement of the plates 13 parallel to the plane of development of the second structural element 5 and orthogonal to the longitudinal axis of the same. As can be observed in Figure 10, the sliding coupling is obtained by making a slit 15 in the centre body 14 according to said direction of movement and thanks to the presence of pin means 16 fixed to the underside of said plates 13 and cooperating with said slit 15.

The thrust actuators 10 are directed in such a way that their expandable rods 12 move out towards the centre area 141 of the centre body 14, as can be observed in Figure 9. In this centre area 141 , the centre body 14 is provided with a wall 142 that extends orthogonally with respect to the plane of development of the same centre body 14.

In this way, when the expandable rods 12 move out of the corresponding cylinders 11 , they come into contact with the wall 142 generating said two thrusting forces N, which in turn cause the two plates 13 to move away from each other and from the centre body 14. The amplitude of this movement is directly proportional to the amplitude of the movement of said expandable rods 12 when they move out of the corresponding cylinders 11.

Since, as shown in Figure 7, the holes 52 are made in the plates 13 of the second structural element 5, the movement of the same plates 13 causes the movement of the two section elements 17 and 18 of the first structural element 2, and thus of the corresponding side walls 4. In turn, as already explained, said two side walls 4, moving away from each other, exert a thrusting force in opposite directions on each one of the side walls L of the housing U. This operation makes it possible to fix the coupling system 100 of the invention inside the housing U defined in the fixed structure S.

As can be observed in Figure 10, the thrust actuators 10 are preferably but not necessarily equipped with adjusting means 19, accessible at the level of the outer surface 51 of the second structural element 5. Said adjusting means 19 make it possible to adjust the amplitude of the movement of said rods 12 out of the corresponding cylinders 11.

According to an alternative variant of said second preferred embodiment of the invention, the expansion unit 9 may comprise a shaped element slidingly coupled with the second structural element 5 in the direction orthogonal to the longitudinal axis of development of the latter. This shaped element, in turn, may comprise a vertical wall suited to be placed in contact with the inner surface 41 of one of the two side walls 4 of the first structural element 2. Furthermore, said shaped element may comprise an inclined surface facing towards the centre wall 3 of the first structural element 2 itself.

The expansion unit 9 may furthermore comprise, for each one of said two shaped elements, a thrusting element with truncated cone-shaped profile coupled with the second structural element 5 in a movable manner according to the direction that is substantially orthogonal to the plane of development of the latter. The thrusting element may be provided with a contact surface cooperating with the inclined surface of the shaped element, in order to define said thrust component N towards the inner surface 41 of one of the two side walls 4, when the thrusting element is moved near the second structural element 5. Also in this case, said operation of moving the thrusting element near the second structural element may be performed through adjusting means that can be accessed at the level of the outer surface 51 of the second structural element 5.

Finally, according to said alternative embodiment of the invention, the expansion unit 9 may comprise counteracting means resting on each one of the thrusting elements, on the opposite side of the corresponding shaped element.

Said counteracting means would be configured in such a way as to prevent the movement of the thrusting elements parallel to the plane of development of the second structural element 5. In this way, in fact, it would be possible to guarantee that the movement of the thrusting element towards the second structural element 5 generates, in cooperation with the shaped element, said thrusting force N towards the inner surface 41 of one of the two side walls 4, thus preventing the thrust component generated by the thrusting element from being dissipated due to the movement of the latter towards the centre wall of the second structural element 5.

It cannot be excluded that in further alternative embodiments of the invention said expansion unit 9 may be made in a different manner than described up to now, provided that it is capable of generating said two thrust components N and, consequently, provided that it can part the two side walls 41 of the first structural element 2.

From the operating point of view, in the case of the coupling system 1 according to the first embodiment of the invention, as shown in Figures 5 and 6, the fixing operation is preferably but not necessarily performed using external fixing elements F, like for example screws and dowels. In the case, instead, of the coupling system 100 of the second preferred embodiment, the fixing operation, as already explained, is performed by means of the expansion unit 9. In particular, the fixing operation includes the steps of inserting the coupling system 100 in said housing U and, successively, acting on the expansion unit 9 through the adjusting means 19, in such a way as to force the two side walls 4 of the first structural element 2 away from each other and, consequently, to determine the coupling through interference between these and the side walls L of the housing U.

It is evident that, in the second case, the fixing operation is much quicker and more comfortable compared to the use of external fixing elements F, mainly because the latter require the performance of preliminary operations, like for example the drilling of holes in the fixed structure S in order to insert the dowels and fix the screws therein.

In both of the preferred embodiments of the coupling systems 1 and 100 of the invention, once the fixing operation has been completed the two structural elements 2 and 5 are mutually arranged in said second position of maximum distance, as respectively shown in Figure 6 and in Figure 8, as the thrusting force exerted by the elastic means 8 is not counteracted by any other force. In order to proceed to the connection of the movable wall P to said coupling system 1 , 100, the end P1 of the same movable wall P is inserted in the housing 6 defined in the second structural element 5.

While this operation is being performed, the movable wall P exerts a thrusting force at the level of the second structural element 5, counteracting the thrusting force exerted by the elastic means 8. Consequently, said second structural element 5 is made slide from said second position towards the first position of minimum distance. When the movable wall P is completely connected to the coupling system 1 and 100, the second structural element 5 is arranged, with respect to the first structural element 2, in an intermediate position between said first and said second position, as shown in Figure 1 1 with reference to the coupling system 100 of the second preferred embodiment of the invention. In this way, advantageously, in the case of the vertical shocks generated by an earthquake or in any case of relative displacements in the vertical direction of the fixed structures S between which the movable wall P is interposed, the coupling system 1 and 100 of the invention is capable of attenuating and neutralizing the effects of both an increase and a decrease in the distance between said two fixed structures S, advantageously avoiding abrupt stresses on the movable wall P.

Furthermore, the presence of said elastic means 8 in the coupling systems of the invention 1 and 100 makes it possible to obtain two important advantages. In the case of a normal situation, meaning in the absence of relative displacements of the fixed structures S in the vertical direction, the thrusting force exerted by the elastic means 8 on the movable wall P makes it possible to obtain a higher stability of the connection compared to a situation in which said elastic means 8 are not present. Furthermore, in the case of anomalous situations, that is, when there is a temporary variation of the distance between the fixed structures S between which the movable wall P is interposed, the presence of said elastic means 8 first of all contributes to attenuating said variation and secondly makes it possible to rapidly re-establish the situation of normality between movable wall P and fixed structure S shown in Figure 1 1 . Based on the above, therefore, it can be stated that the coupling system of the invention achieves all the set objects.

In particular, the invention achieves the object to provide a coupling system that is capable of effectively attenuating and neutralizing the effects of a possible variation in the distance between the fixed structures between which a wall of the movable type is interposed and with which it is coupled.

In greater detail, the invention achieves the object to provide a coupling system that is capable of attenuating a variation in the distance between the fixed structures both when it takes place once in a while, for example when a larger load than in normal conditions is applied to the ceiling on which said coupling system is installed, and when the variation in said distance occurs repeatedly, for example in the case of the vertical shocks generated by an earthquake. Furthermore, the invention achieves the object to provide a coupling system that is capable of attenuating said variation in the distance independently of whether it is of the temporary type, meaning when, at the end of the event that caused said variation, the initial conditions are restored, or of the permanent type, in the case where, for example, the larger load applied to the ceiling is not removed.

Therefore, the invention achieves the object to provide a coupling system that is capable of attenuating the relative displacements of two fixed structures caused by the vertical shocks generated by an earthquake. A further object achieved by the invention is the object to provide a coupling system that is capable of operating correctly for a long time, with no risk of seizures and jams due to wear.

Claims

1 ) Coupling system (1 , 100) for coupling at least one movable wall (P) with a fixed structure (S), of the type comprising:

- a first structural element (2) with substantially longitudinal development, configured so as to be fixedly coupled with said fixed structure (S);

- a second structural element (5) with substantially longitudinal development, spaced from said first structural element (2) and provided with coupling means (6) for said movable wall (P);

- a plurality of guide means (7) extending from a surface of said first structural element (2) and defining a sliding direction (X), said plurality of guide means

(7) being slidingly coupled with said second structural element (5) so as to allow said second structural element (5) to move along said sliding direction (X) from a first position of minimum distance from said first structural element (2) to a second position of maximum distance from said first structural element (2) and vice versa;

- elastic means (8) arranged between said first structural element (2) and said second structural element (5), said elastic means (8) being configured in such a way as to exert two opposite thrusting forces towards said two structural elements (2, 5) when the distance between said two structural elements (2, 5) is shorter than said maximum distance defined at the level of said second position;

characterized in that said first structural element (2) comprises two section elements (17, 18), each one of which has L-shaped cross section, said L-shaped cross section being defined by a centre wall (3) at the end (31 ) of which a side wall (4) develops, said guide means (7) extending from the inner surface (32) of said centre wall (3) of each one of said section elements (17, 18), so that said sliding direction (X) is substantially parallel to said side wall (4) of each one of said section elements (17, 18), said coupling system (1 , 100) furthermore comprising an expansion unit (9) housed in said second structural element (5) and configured so as to exert two thrusting forces (N) in opposite directions against the inner surfaces (41 ) of said two walls (4) of said first structural element (2), in such a way as to cause the relative displacement of said two side walls (4) in a direction substantially parallel to the plane of development of said second structural element (5).

2) Coupling system (1 , 100) according to claim 1 , characterized in that said plurality of guide means (7) comprises a plurality of rods (71 ), each one of which is provided, at the level of its free end, with a stop element (72), and in that said second structural element (5) is provided with a plurality of holes (52), each one of said holes (52) being suited to accommodate one of said rods (71 ) in such a way as to allow said second structural element (5) to move along said sliding direction (X) from said first position to said second position defined at the level of said stop elements (72) of said rods (71 ).

3) Coupling system (1 , 100) according to claim 2, characterized in that said plurality of elastic means (8) comprises a plurality of helical springs (81 ), each one of said helical springs (81 ) being fitted coaxially on one of said rods (71 ) between said first structural element (2) and said second structural element (5).

4) Coupling system (100) according to any of the preceding claims, characterized in that said expansion unit (9) comprises at least two thrust actuators (10), each one of which is provided with a cylinder (1 1 ) that supports an expandable rod (12), said two thrust actuators (10) being arranged on said second structural element (5) so as to generate, through the outward movement of said two expandable rods (12), two opposite thrust components (N) on said inner surfaces (41 ) of said two side walls (4) of said first structural element (2).

5) Coupling system (1 , 100) according to any of the preceding claims, characterized in that said coupling means (6) defined in said second structural element (5) comprise at least one housing (61 ) created in the outer surface (51 ) of said second structural element (5) opposite said centre wall (3) of said first structural element (2), said housing (61 ) being suited to house an end (P1 ) of said movable wall (P).