ELEMENT FOR JOINING MODULES WITH MAGNETIC ANCHORAGE FOR THE CONSTRUCTION OF STABLE GRID STRUCTURES

The present invention relates to a joining system to be used in an assembly of modules with magnetic anchorage for the construction of stable grid structures which are used in the sector of games or also in the area of display or furnishing.

From WO-A-9960583 of the same Applicant, an assembly of modules is known which optimises the exploitation of the magnetic energy available for anchorage between the modules in such a way as to achieve a plurality of grid structures having the most inventive and complex shapes.

The point of magnetic coupling between two modules can be chosen as required at any one of the zones of the magnetically active and/or ferromagnetic surface of one of the modules and is not restrained by a predefined orientation between the two modules, in such a way that the modules of the assembly can be combined overall one with the other, obtaining a plurality of shapes.

In all systems of magnetic anchorage assembly known today, and above all in those magnetic anchorage assemblies which under-use the magnetic energy available for anchorage between modules, it is seen how some shapes of the grid structure do not have the appropriate requirements of stability and capacity for self-support, particularly as regards resistance to shearing or slipping and to bending.

In these cases the shape of the original grid structure has to be modified by adding thereto - ad hoc - other modules for ensuring its stability.

This solution, in addition to modifying the original shape of the grid structure required, may cause an excessive increase in the weight and cost of the grid structure itself.

In order to avoid this disadvantage, WO-A-02055168 of the same Applicant, provides elements for stabilisation of the grid structure in the form of panels which can be removably fitted in corresponding polygonal areas defined by the modules of the grid structure.

The main object of the present invention is to provide a joining system for an assembly of modules with magnetic anchorage for the construction of grid structures which achieve, using the same number of magnetic modules, improved resistance to deformation due to stresses of shearing, slipping, torsion or bending.

Another object of the present invention is to provide a joining system for an assembly of modules with magnetic anchorage for the construction of grid structures with the required shape which have been made stable without the shape having been modified and without the overall cost and weight having been increased excessively.

These objects are achieved, in an assembly of modules with magnetic anchorage for the construction of a grid structure, by a joining system comprising a first joining element for connecting rigidly at least a first and a second elongated modules of the grid structure, according to claim 1, and a second joining elements according to claim 16.

With such a joining elements two or more elongated modules are attached in predefined angular directions but do not come into direct contact one with the other, being connectable via an additional module of the grid structure.

Further features of the joining system are defined by the dependent claims.

The joining elements of the present invention can be made in a lightweight and economical material and enable extremely stable grid structures to be obtained without jeopardising the original simplicity and flexibility of assembly,

These aspects will be made clearer from the following reading of some preferred embodiments of the invention, to be read by way of a non-limiting example of the more general concept claimed.

The following description refers to the accompanying drawings, in which:

• Fig. 1 is a perspective view of a preferred embodiment of the first joining element for a grid structure of spherical and cylindrical modules with magnetic anchorage;
• Figure 2 is a side elevation view, partially sectioned axially, of a cylindrical module of the grid structure which can be connected to the joining element of Figure 1;
• Figure 3 is a perspective view of a portion of a grid structure which uses the joining element of Figure 1 and the cylindrical modules of Figure 2;
• Figure 4 shows a perspective view of another embodiment of a first joining element in accordance with the present invention;
• Figure 5 is a plan view from above of a portion of grid structure which uses the joining element of Figure 4 sectioned by the plane containing the broken line L-L; and
• Figure 6 shows a front perspective view of another embodiment of the first joining element of the present invention;
• Figure 7 is a view of a portion of grid structure which uses second joining elements (shown partially sectioned) in accordance with the present invention.

With reference to Figures 1-3, the grid structure is formed by cylindrical modules 1 with bevelled edges and by spherical modules 3 placed at nodes of the grid structure.

Naturally Figure 3 only illustrates a portion of a grid structure which in actual fact can reach the required three-dimensional shape and extension.

The spherical modules 1 are in a ferromagnetic material, for example in mild steel covered with an antioxidant material.

The cylindrical modules 3 are instead composed of: a cylindrical ferromagnetic pin 5; a pair of cylindrical magnetic elements 7 magnetised axially and attached with opposite magnetic polarity (in Figure 2 n denotes the north polarity and s the south polarity of the magnetic elements 7) at the end bases of the pin 5 coaxially to the pin 5; and a non-magnetic tubular matrix 9 which covers the lateral surface of the pin 5 and magnetic elements 7 and which has the base ends bevelled.

The joining element 11 comprises a body 13 shaped like a semi-spherical cap or shell .

The body of the joining element 11 forms a housing 14 defined by the internal surface of the body of the joining element 11 and having radius equal to that of the spherical module 1 of the grid structure to be secured into said housing 14.

The body of the joining element 11 further has three tubular projections 15, orthogonal one in relation to the other, which extend radially from the same body 13 towards the outside thereof and which have the internal hollow section with radius equal to that of the cylindrical modules 3.

The tubular projections 15 both have the axially end bases open. Inside the internal radially end base of each tubular projection 15 it is possible to provide a bevelled annular shoulder (not illustrated) acting as a stop for the bevelled edge the matrix 9 covering the cylindrical module 3 in such a way that the radially internal base of the cylindrical element 3 is aligned with the radially internal base of the tubular projection 15.

The edge of the semi-spherical body 13 has three sections which extend beyond the maximum meridian line 21 of the semi-spherical body 13 defining clips 17, alternating with three recesses 19 of a complementary shape which extend within the maximum meridian line 21 for housing the clips 17.

As can now be seen in particular from Figure 3, the grid structure defines cubic cells whose sides are occupied by the cylindrical modules 3 and whose tops or nodes are instead occupied by the spherical modules 1.

The joining element 11 is attached to the spherical module 1 before inserting the cylindrical modules 3 in the corresponding projection 15 on the side of the radially external end base of the projection 15.

The housing 14 of the joining element 11 encapsulates a half-part of the spherical module 1 and each joining element 11 thus remains attached to the spherical module 11 thanks to the hold on the spherical module 1 by the clips 17. Subsequently the cylindrical modules 3 to be contacted to the spherical module 3 encapsulated by the housing 14 of the joining element 11 can be inserted in the projections 15 of the joining element 11.

In the case wherein the spherical module 1 is arranged in a peripheral node of the grid structure wherein three cylindrical modules 3 have to converge, it is sufficient to attach to the spherical module 1 one single joining element 11, while in the case wherein the spherical module 1 is arranged in an internal node of the grid structure wherein six cylindrical modules 3 have to converge, it is necessary to attach to the spherical module 1 two joinin elements 11 which slot, making the complementary clips 17 and recesses 19 of the two joining elements 11 match in such a way that the projections 15 of the two joining elements 11 are coaxial in pairs.

The joining elements 11 can be attached in all or, according to the cases, only in some appropriate nodal points of the grid structure, for example in the nodal points of zones of the grid structure most stressed.

What is described above must also be deemed as extending to cases wherein the modules of the grid structure are different from the cylindrical and spherical modules shown hitherto.

The grid structure can for example be formed by parallelepiped elongated modules and by cubic modules arranged at the nodes of the grid structure. In this case the joining element will have a framework formed with orthogonal flat faces matching corresponding faces of a cubic module of the grid structure, and tubular projections which extend from at least two faces of the framework.

The projections 15 of the joining element 11 can finally be non-aligned one in relation to the other being arranged with an acute or obtuse angle.

It must be noted above all that the joining element 11 does not generate undesirable dispersions of magnetic flow from the magnetic circuit which is formed via the modules of the grid structure connected thereby.

Figures 4 and 5 show a further preferred embodiment of the first joining element according to the present invention wherein the element 11''' for joining cylindrical modules 3''' of the type in Figure 2 comprises three tubular projections 15''', orthogonal one in relation to the other and arranged radially and at a predetermined radial distance from a common centre of symmetry 29.

The joining element 11''' has a body 33 whereform the projections 15''' extend. Such a body of the joining element is defined by three flattened ribbings 31 which develop between the opposite axial generatrices of the side wall of each pair of adjacent projections 15''' of the joining element 11'''.

In this embodiment too the projections 15''' have both axial ends open.

The internal edges 16''' of the flattened ribbings 31 define a surface of an open spherical housing of the body 33 of the joining element 11''' for securing a spherical module 1' into said open housing of the body 33.

The peripheral spherical surface of the body 33 has radius equal to the radius of the spherical module 1', the latter being preferably of ferromagnetic type.

The radially internal end bases of the projections 15''' open onto the body 33 in such a way as to be able to directly match with the spherical surface of the spherical ferromagnetic module 1'.

Inside the radially internal end of the three tubular projections 15"' a bevelled annular shoulder 35 is formed wherein the bevel 25' of the three cylindrical modules 3''' fits, so that each cylindrical module 3''' can be placed in line with the radially internal base of the respective projection 15''' and can touch directly a spherical module 1', while the joining element 11''' remains blocked between the cylindrical modules 3''' and the spherical module 1'.

The annular shoulder 35 which acts as a stop for the corresponding cylindrical module 3''' plays an important role when a ribbing 31 of the support framework of the joining element 11''' is used in a horizontal position for supporting the corner of a panel or of a shelf to be fixed to the grid structure. In this case the weight of the shelf or of the panel can be discharged and distributed on the vertical cylindrical modules 3''' opposite the ribbings 31 whereon the shelf or panel rests.

Naturally more than one joining element 11''' for the cylindrical modules 3''' can be attached to the spherical surface of the same module 1' and a joining element 11''' can be attached in any portion of the spherical module 1'.

Advantageously moreover a cylindrical module 3''' can be connected directly to the spherical module 1' through the open body 33.

Figure 6 shows a further preferred embodiment of the first joining element 11'''' of the present invention wherein the element 11"" for joining cylindrical modules 3"" of the type in Figure 2 comprises two tubual projections 15"" having the end bases open. The projections 15"" are orthogonal one in relation to the other and have attachment axes which extend radially from a common centre.

The joining element 11"" comprises a body wherfrom the projections 15"" extend. The body of the joining element is formed by a plate bent at a right angle. The projections 15"" extend from the side of the convex surface of the body 37 and have the radially internal open end base on the body 37, while the concave surface 36 forms a housing for securing a parallelepiped module 39.

The projections 15"" are also connected by a flat ribbing 31' which extends between the opposite axial generatrices of the side walls of the two projectons 15"".

Inside the radially internal end base of the projections 15"" a bevelled annular shoulder can be provided (not shown), acting as an a stop for the cylindrical element 3"" inserted in the projection 15"" on the side of the radially external end base of the projection attachment 15"".

Along the edge of the concave surface 36 of the body 37 a fixed or removable tooth 41 is formed which can fit into any one of the notches 43 formed at regular intervals on the edge 38 of the ferromagnetic parallelepiped module 39.

The concave surface 36 of the body 37 matches that of the parallelepiped module 39 and thus allows the two cylindrical modules 3"" to be maintained in direct contact with the parallelepiped module 39.

The joining element 11"" in this case blocks the relative angular arrangement between the two cylindrical modules 3"" and simultaneously the position of the cylindrical modules 3"" on the longitudinal axis of the ferromagnetic module 39, and can therefore in this case too be used for the support of shelves and/or panels.

Obviously it is possible to adopt a cylindrical module instead of module 39 and a corresponding semicylindrical coupling part of the body of the joining element instead of body 37 without departing from the scope of the invention: generally speaking the body of the joining element according to the present invention has to provide a housing for a further module, said housing comprising a surface shaped as the peripheral surface of said further module for engaging said further module.

Figure 7 shows further preferred embodiments of a second joining element 11" of the present invention which can be used for head-joining two cylindrical modules 3' of the type in Figure 2.

In this case each joining element 11" has a tubular body having a pair of tubular projections 15', 15' or 15", 15" directly connected one to the other extend.

In Figure 7 the body of one joining element 11' has coaxial projections 15', 15' while the other joining element 11" has non-aligned projections 15", 15".

By varying the angle of non-alignment and the axial distance of the subsequent cylindrical modules 3' of the grid structure it is possible to create three-dimensional figures of any shape and complexity, for example "S" or "U" shapes.

As can be seen again from Figure 7, the joining element 11', in the point of connection between the projections 15' 15', defines a bevelled internal annular shoulder 23 wherein the bevel 25 of the cylindrical modules 3', in the projections 15', 15', fits. The bevelled annular shoulder 23 of the joining element 11' therefore serves as an stop for the two cylindrical modules 3' which, having achieved the position of end of stroke, are joined at the head and in direct contact one with the other.

Again in Figure 7, into the curved tubular coupling portion of the body of the joining element 11" for coupling the tubular projections 15", 15", an axial spacer 27 with a trapezoidal shape is integrated and which allows two cylindrical modules 3' to be head-joined and at the same time the axial distance between them to be adjusted to a predefined value.

The axial spacer 27 can be a piece of ferromagnetic material which does not introduce dispersion of magnetic flow at the join or in turn can be a magnetic module oriented in such a way as to combine in series its magnetic potential difference with those installed in the magnetic circuit generated by the grid structure.

Naturally a spacer can be provided even in a right tubular coupling portion between coaxial projections of the body of the joining element.

Figure 7 therefore discloses a second joining element for the head-joining of two elongated modules to be placed in direct contact one with the other or to be connected with the interposing of an axial spacer directly integrated in the joining element.

In any case it is possible to extend the teaching of Figure 7 also to the case of joining elements with more than two projections for the attachment of elongated modules. The joining element can be formed by three tubular projections arranged as a "T" or respectively by several projections arranged in a star.

Inside the body of the joining element, in the central tubular coupling portion between the projections, a ferromagnetic or a magnetic insert in contact with the elongated modules inserted in the attachments can be integrated so as to avoid dispersions of the magnetic flow which is formed via the modules connected by the joining element

The angular orientation of the projections of the body of a joining element in accordance with the present invention can be different from that shown, for example the projections can form an acute or obtuse angle one in relation to the other.

In the case wherein an elongated module to be connected via the joining element of the present invention is subjected to a stress of pure traction, it is possible to provide means for blocking its axial sliding in relation to the projection wherein it is inserted, formed for example by a transverse pin inserted through special holes provided in the projection and in the elongated module inserted in the projection. Therefore, even when the sole force of magnetic anchorage acting on the elongated module subjected to traction is less than the tractive force acting thereon, the detachment of the elongated module from the assembly is now contrasted not only by the magnetic anchorage force of the elongated module subjected to traction but also by the magnetic anchorage force, evaluated in the direction of traction of the elongated module subjected to traction, exerted by part of the other elongated modules of the assembly connected via the joining element which involves the elongated module subjected to traction.

The joining elements 11, 11', 11", 11''', 11"" can stiffen the grid structure without altering its appearance and for this reason are preferably made in a transparent and rigid plastic material.

The cylindrical modules 3, 3', 3''', 3"" are oriented in such a way that the differences of magnetic potential generated by them in the magnetic circuit formed via the grid structure are combined in series. The system of stiffening of the present invention enables the procedure for assembly of modules described in WO-A-9960583 the same Applicant, to be applied.

In particular the modules which form the grid structure can thus be modules of a first type, consisting of at least one active magnetic element, that is to say an element which has two surfaces of opposite polarity, at least one ferromagnetic element and possibly a non-magnetic covering matrix, or modules of the first type combined with modules of a second type, the latter consisting of a ferromagnetic element if necessary inserted in a non-magnetic covering matrix.

The assembly of the modules is carried out in such a way that the magnetic flow generated by the active magnetic elements involved in the anchorage closes totally or at least partially via the ferromagnetic parts of the grid structure, and in such a way that the differences of magnetic potential produced in the magnetic circuit generated by the active magnetic elements which form the anchorage are combined in series.