The present invention relates to a joint for connecting tubular elements, particularly suitable for use in structures for which lightness combined with a high strength and resistance characteristics are required.

The joint of the present invention is, for example, advantageously applied in the field of loads transport containers, which for their particular type of use may be subject to shock or high stress from the outside .

In particular conditions of use, these containers could be transported by air and deposited, or rather, dropped thus falling with high speed.

For transport purposes, and to resist to the shocks caused by falling, these containers must therefore have a non excessive weight and an external structure that can resist to the shocks caused by their fall from the height.

For the construction of the container, here proposed joints are mounted on the frame of the same container, in correspondence of the respective external corners and, possibly, also of intermediate parts.

Since the air transport of such containers are often moving at the time in which they are released, the impact of the container, at the time of the impact on the ground, mainly affects the respective corner areas .

In the following, the description will be directed to the use of the joint according to the present invention in a container, but it is clear that the same should not be considered limited to this specific use, being it conveniently used also for the construction of other structures.

In light of the above, it is, therefore, object of the present invention to provide a joint for connecting tubular elements, which, at the same time, has mechanical resistance and lightness.

Another object of the invention is to provide a coupling for connecting tubular elements, having such structure as to effectively distribute the stresses acting on it.

A further object of the present invention is to provide a container that has high characteristics of mechanical resistance and lightness.

It is therefore specific object of the present invention a joint for connecting tubular elements, comprising: a first structural element, comprising a first plate and a second plate which is arranged substantially orthogonally with respect to said first plate, a second structural element comprising a first plate and a second plate which is arranged substantially orthogonally with respect to said first plate, a third structural element comprising- a first plate and a second plate arranged substantially orthogonally with respect to said first plate, connecting means for reciprocally connecting said first structural element, said second structural element and said third structural element, wherein said first plate of said first structural element and said second plate of said second structural element are reciprocally faced and parallel such as to form a first pair of plates, said first plate of said second structural element and said second plate of said third structural element are reciprocally faced and parallel such as to form a second pair of plates, said first plate of said third structural element and said second plate of said first structural element are reciprocally faced and parallel such as to form a third pair of plates.

Further according to the invention, said first pair of plates, said second pair of plates and said third pair of plates form could a triad of Cartesian orthogonal axes .

Still according to the invention, said first plate and said second plate of said first structural element respectively could lie on planes which are reciprocally substantially orthogonal, said first plate and said second plate of said second structural element respectively could lie on planes which are reciprocally substantially orthogonal, and said first plate and said second plate of said third structural element respectively could lie on planes which are reciprocally substantially orthogonal.

Advantageously according to the invention, said first structural element, said second structural element and said third structural element could be mounted so as to form between them a joint in correspondence of the respective connection areas between the respective first plate and second plate of each of said first structural element, the second structural element and third structural element, and in such a way that they are mutually facing the first plate of said third structural element with the second plate of said first structural element, the first plate of said second structural element with the second plate of said third structural element, and the first plate of said first structural element with the second plate of said second structural element . Preferably according to the invention, said connecting means could comprise at least one connecting element which has substantially parallelepiped shape and is provided with at least one threaded hole.

Further according to the invention, said joint could comprise first connecting means provided in said first pair of plates to connect said first pair of plates with a first tubular element, second connecting means provided in said second pair of plates to connect said second pair of plates with a second tubular element, and third connecting means provided in said third pair of plates to connect said third pair of plates with a third tubular element.

Still according to the invention, said first connecting means, said second connecting means and said third connecting means could respectively comprise at least one hollow screwing element, which is provided with a threaded through hole, and at least one stop dowel having such a shape that it may be coupled with said threaded through hole.

Preferably according to the invention, said joint could comprise a fourth structural element comprising a pair of plates which are reciprocally parallel and faced, and arranged substantially aligned with said second pair of plates.

Further according to the invention, said first structural element, said second structural element and said third structural element could respectively comprise a third plate, which is connected with said first plate and said second plate (103a, 103b, 103c) at angles of about 45°.

Still according to the invention, said joint could comprise a front sealing element and a rear sealing element where a first opening and a second opening are formed, said front sealing element and said rear sealing element being arranged such as to form a space therebetween communicating with said first opening and second opening.

It is object of the present invention also a container comprising at least one joint according to any one of previous claims.

Preferably according to the invention, said container could have a substantially parallelepiped overall shape and could comprise eight joints according to claim 7 or 8 , which are arranged at corner regions of said container, respectively.

Further according to the invention, said container could comprise eight joints according to claim 6 which are arranged at intermediate regions of said container.

The present invention will be now described, for illustrative but not limitative purposes, according to its preferred embodiments, with particular reference to the figures of the enclosed drawings, wherein:

figure 1 shows a first perspective view of a joint according to a first embodiment of the present invention;

figure 2 shows a second perspective view of the joint of figure 1;

figure 3 shows an exploded view of the joint of figures 1 and 2;

figure 4 shows a perspective exploded view of a joint in a second embodiment of the present invention; figure 5 shows a perspective view of the joint of figure 4, in a mounted configuration; and

figure 6 shows a perspective exploded view of a container comprising the joints shown in figures 1-5. In the various figures, similar parts will be indicated by the same reference numbers .

Referring to figures 1 to 3 , with the reference number 1 is indicated a joint comprising a first structural element la, a second structural element lb and a third structural element lc.

Each of said first structural element la, second structural element lb and third structural element lc comprises a first plate 2a, 2b, 2c with a substantially rectangular plan defined by a first larger side 21a, 21b, 21c and a second larger side 21a' , 21b' , 21c' mutually opposite and from a first smaller side 22a, 22b, 22c and a second smaller side 22a' , 22b' , 22c' mutually opposite.

Each of said first structural element la, second structural element lb and third structural element lc also includes a second plate 3a, 3b, 3c with a substantially rectangular plan, which extends perpendicularly with respect to said first plate 2a, 2b, 2c, from an end portion of said second larger side 21a' , 21b' , 21c' of said first plate 2a, 2b, 2c.

Each second plate 3a, 3b, 3c is defined by a third larger side 31a, 31b, 31c and a fourth larger side 31a' , 31b' , 31c' mutually opposite and a third smaller side 32a, 32b, 32c and a fourth smaller side 32a' , 32b' , 32c' mutually opposed.

On the third larger side 31a, 31b, 31c and on the fourth larger side 31a' , 31b' , 31c' of each second plate 3a, 3b, 3c are respectively formed a first recess 33a, 33b, 33c and a second recess 33a', 33b', 33c', which develop from the corresponding third smaller side 32a, 32b, 32c and having a longitudinal extent greater than said first smaller side 22a, 22b, 22c and second smaller side 22a' , 22b' , 22c' of the respective first plate 2a, 2b, 2c.

On each first plate 2a, 2b, 2c a first abutment element 40a, 40b, 40c and a second abutment element 41a, 41b, 41c substantially wedge-shaped and provided with a respective concavity summit abutment are provided.

On each first plate 2a, 2b, 2c is also provided a first through hole 42a, 42b, 42c arranged between said second abutment element 41a, 41b, 41c and said first shorter side 22a, 22b, 22c.

On each second plate 3a, 3b, 3c a second through hole and a third through hole are formed, in correspondence of which respectively a first nut screw wedge-shaped element 50a, 50b, 50c and a second nut screw wedge-shaped element 51a, 51b, 51c are fixed, provided with respective threaded through holes, in which, during installation, a first grain 52a, 52b, 52c and a second grain 53a, 53b, 53c are screwed.

On each second plate 3a, 3b, 3c is also obtained a fourth through hole 54a, 54b, 54c arranged between said second nut screw wedge-shaped element 51a, 51b, 51c and said third smaller side 32a, 32b, 32c of said second plate 3a, 3b, 3c.

The joint 1 also provides a quarter structural element Id formed by a base plate 2d from which, a first side plate 3d and a second side plate 3d' , so as to form a sort "U" , extend perpendicularly, in correspondence of two opposite edges.

On said two side plates 3d, 3d' , in correspondence of the base plate 2d, a first through hole 4d and a second through hole 4d' mutually coaxial are respectively formed. On said first side plate 3d there further are a third through hole 5d and a fourth through hole 6d, arranged between said first through hole 4d and the edge of the free end of said first side plate 3d.

On said first side plate 3d, in correspondence of the third through hole 5d and the fourth through hole 6d, a third nut screw wedge-shaped element 9d and a fourth nut screw wedge-shaped element lOd are mounted, provided with respective threaded through holes, in which respective grains are screwed, in the installation phase.

On said second side plate 3d' a first abutment element lid' and a second abutment element 12d' , substantially wedge-shaped, are, instead, mounted, provided with a respective abutment top concavity and respectively arranged facing the third nut screw wedge- shaped element 9d and the fourth nut screw wedge-shaped element lOd.

The joint 1 also comprises a first stabilization element 60a, a second stabilization element 60b, a third stabilization element 60c and a fourth stabilization element 60d, whose positioning will be better specified below.

Said first 60a, second 60b, third 60c and fourth stabilization element have a substantially parallelepiped shaped and are provided with respective threaded through holes .

The assembly of the joint 1 described above provides that the above said first structural element la, second structural element lb and third structural element lc are mounted so as to form between them a joint, in correspondence with the respective connection zones between the respective first plate and second plate of each structural element la, lb, lc, and in such a way that the first plate 2c with the second plate 3a, the first plate 2b with the second plate 3c, and the second plate 2a with the second plate 3b are mutually facing.

Once positioned said structural elements la, lb, lc as above, said stabilization elements 60a, 60b, 60c are assembled by aligning their threaded through holes with first through holes 42a, 42b, 42c, and quarters through holes 54a , 54b, 54c, and locked in position by screwing locking screws 55 in said holes.

Once the assembly operations described above are terminated, the base plate Id of the fourth structural element is fixed to the first plate 2c of the third structural element lc by means of screws or bolts, positioning said fourth structural element Id so that its two side plates are, respectively, substantially coplanar with the second plate 3b of the second structural element lb, and with the first plate 2a of the first structural element la.

At this point, the fourth stabilization element 60d is mounted, placing it between the through holes of the two side plates of the fourth structural element Id and locking it in position by means of two locking screws 55.

The joint 1 is, therefore, a four-way joint, or four branches joint, wherein the first branch is formed by the plates 2b and 3c, the second branch is formed by the plates 2a and 3b, the third branch is formed by the plates 2c and 3a and fourth branch is formed by the plates 3d and 3d' .

The joint 1 may be configured, in case of necessity, also as a three-way joint, or three branches joint, simply by not providing the mounting of the fourth structural element Id.

Referring now to figures 4 and 5, with a joint 100 is indicated a second embodiment of the present invention.

The joint 100 comprises a first structural element 100a, a second structural element 100b and a third structural element 100c.

Each one of said first 100a, second 100b and third 100c structural element includes a first plate 101a, 101b, 101c from which it extends, inclined by about 45°, a second plate 102a, 102b, 102c coplanar with said first plate 101a, 101b, 101c.

From a respective edge of the second plate 102a, 102b, 102c opposite to the first plate 101a, 101b, 101c develops, inclined by about 45°, a third plate 103a, 103b, 103c, so as to be perpendicular to said first plate 101a, 101b, 101c and second plate 102a, 102b, 102c.

On each first plate 101a, 101b, 101c are formed a first through hole 120a, 120b and a second through hole 121a, 121b, in correspondence of which respectively a first nut screw wedge-shaped element 122a, 122b, 122c and a second nut screw wedge-shaped element 123a, 123b, 123c are fixed, provided with respective threaded through holes, in which are screwed, in the installation phase, the respective grains.

On each first plate 101a, 101b, 101c is also formed a third connecting through hole 125a, 125b, 125c, located at the zone of connection between said first plate 101a, 101b, 101c and said second plate 102a, 102b, 102c.

On each second plate 102a, 102b, 102c two through holes 126a, 126b, 126c, 127a, 127b, 127c are formed.

On each third plate 103a, 103b, 103c a first abutment element 128a, 128b, 128c and a second abutment element 129a, 129b, 129c substantially wedge-shaped are provided and provided with a respective to concavity abutment .

On each third plate 103a, 103b, 103c a connecting through hole 130b, 130c, is also formed located at the connection zone with the respective second plate 102a, 102b, 102c.

The joint 100 also includes a first stabilization element 132a, a second stabilization element 132b and a third stabilization element 132c, the positioning of which will be better specified below.

Said first stabilization element 132a, second stabilization element 132b and third stabilization element 132c have a substantially parallelepiped shape and are provided with respective threaded through holes .

The joint 100 also comprises a front closing element 105 and a rear closing element 106.

Said closing element 105 is formed by a front triangular closure wall 107, from which there are two connecting portions 108, 108' - in each of which two through holes 109, 110, 109', 110' are formed - lying on two planes orthogonal to each other.

The rear closure element 106 is, instead, formed by a first rear wall 112, a second rear wall 112', perpendicular to each other, and a bottom wall 113 fixed below said first 112 and second rear wall 112' .

On said first rear wall 112 and second rear wall 112' there are two connecting through holes 140, 140' and two openings 115, 115' formed in the corresponding areas of said walls.

The assembly of the joint 100 described above provides that said first structural element 100a, second structural element 100b and third structural element 100c are arranged so that the first plate 101a is facing the third plate 103b, the first plate 101b is facing the third plate 103c, and the first plate 101c is facing the third plate 103a.

Between said first structural element 100a, second structural element 100b and third structural element 100c said first stabilization element 132a, second stabilization element 132b and third stabilization element 132c are respectively interposed, so as to align to the connecting through holes provided in said first plates 101a, 101b, 101c and third plates 103a, 103b, 103c.

Once arranged said stabilization elements 132a, 132b, 132c in the positions indicated above, they are fixed to said first structural element 100a, second structural element lOObc and third structural element 100c by screwing locking screws into threaded through holes of such stabilization elements.

At this point, it is possible to proceed with the mounting of the front closing element 105, aligning the through holes of the connecting portions 108, 108' with the through holes provided in the second plates 102a, 102b and blocking in position said front closing element 105 by means of locking screws screwed into said through holes.

The rear closing element 106 is, instead, mounted and fixed, by means of blocking elements arranged in correspondence of the two through holes 140, 140' , on the structure made by said first 100a, second 100b and third 100c structural element and related coupling members indicated above, from the opposite side to the front closing element 105, so as to form, with the latter, a compartment communicating with the two above mentioned openings 115, 115' .

The joint 100 described above is, therefore, a three-way joint, or three branches joint, wherein the first branch is formed by the plates 101b and 103c, the second branch is formed by the plates 101c and 103a and the third branch is formed by plates 101a and 103b.

According to further embodiments of the present invention, not shown in the enclosed figures, the branches of the joints 1, 100 described above and shown in figures 1-5 can also be oriented so as to form between them angles different than 90°, such as corners of 45°.

As shown in figure 6, joints 1, 100 described above can be advantageously used, for example, for the construction of a tubular structure modular container 200.

This modular container 200 is substantially made by a plurality of tubular uprights 201 and tubular side members 202, coupled together by means of joints 1, 100 described above and a plurality of infill panels 203 to close the spaces between said uprights 201 and side members 202.

According to a preferred embodiment of the modular container 200 shown in figure 6, for allowing the connection of the tubular side members 202 and the tubular uprights 201, said modular container 200 includes eight joints 100, arranged in correspondence of the related edges, and eight joints 1, arranged in intermediate zones of the same container. In particular, the coupling between the joints 1, 100 and its side members 202 and uprights 201 takes place by inserting into the ends of the latter in the branches of said joints 1, 100 and screwing said grains in the respective nut screw wedge-shaped elements to bring them in abutment with the abutment elements facing them, and continuing to screw them in order to push the plates of the joints against the inner walls of said tubular side members 202 and tubular uprights 201 achieving, thus, the relative connection.

To allow the screwing of the grains when the branches of the joints are inserted in the tubular side members or in the tubular uprights, openings near the ends of the latter are provided.

To ease the transport operations of the container

200, cables, ropes and/or chains may also be employed, connected to transport means - not shown in the figures and the container itself, by passing them, for example, through the compartments and the respective openings 115, 115' of the joints 100 arranged at the corners of said container 200.

Due to their particular structure, the joints according to the present invention make coexist high characteristics of mechanical resistance and lightness.

The present invention has been described for illustrative but not limitative purposes, according to its preferred embodiments, but it is to be understood that modifications and/or changes can be introduced by those skilled in the art without departing from the relevant scope as defined in the enclosed claims.