Title: ELEMENT OF A DAMPING LAYER FOR FLOORS

Technical field of the invention

The present invention relates to an element of a damping layer for floors, in particular for sports floors, such as for example synthetic turf playing fields, athletics tracks, floors of sports facilities, and similar. The present invention also relates to a damping layer made with these elements, a floor comprising the damping layer and a production process of said element of damping layer.

State of the art

It is known to make floors, for example synthetic turf playing fields, first forming a substrate (typically compact, for example in clay ground or in concrete), on which it is laid the walkable surface (for example a synthetic turf layer, usually unrolled from rolls). Over the substrate it can be placed an impermeable film for the lateral rainwater drainage.

Typically, between the walkable surface and the compact substrate it is interposed a damping layer in order to improve the mechanical response to the stresses on the walkable surface (for example a correct rebound of a ball or an appropriate capacity to cushion the impact of the user with the floor, in case of run, jump or fall), with respect to the one that would be provided by the compact substrate alone.

WO 2011/036600 A2 describes a synthetic turf floor comprising a clay ground substrate, a synthetic turf layer and an intermediate elastic supporting structure, arranged between the substrate and the synthetic turf layer, wherein the supporting structure extends in a wavy manner, forming embossed portions which give a desired compliance and wherein slots are provided in the supporting structure for the drainage.

Summary of the invention

The Applicant has found that the known solutions for damping layers have some drawbacks and/or can be improved in some aspects.

First of all, the Applicant has noted that some known damping layers, including for example the damping layer described in WO 2011/036600 A2, can be improved in terms of mechanical response to the stresses, in particular in terms of impact damping capacity.

Furthermore, the Applicant has noted that some known solutions do not allow the correct water drainage from the floor, due to the excessively continuous and/or intricate structure of the damping layer.

Object of the present invention is therefore to provide an element of a damping layer for floors, and a relative damping layer, capable of providing an optimal mechanical response to the stresses caused by the user, for example in order to guarantee to the latter suitable safety conditions thanks to an optimal absorption of the stresses in case of impact with the floor after fall.

Object of the present invention is to provide an element of a damping layer for floors that is at the same time sturdy and wear-resistant, and with a high capacity of water drainage from the walkable surface.

According to the Applicant, the problem of realizing one or more of these objects is solved by an element of a damping layer for floors according to the attached claims and/or having the following features.

According to an aspect the invention relates to an element of a damping layer for floors comprising:

- a frame provided with through openings, the frame forming a first face;

- a plurality of supporting elements which form a second face opposite to the first face.

Preferably said element of the damping layer comprises, for each supporting element, a plurality of arms which connect said each supporting element to said frame.

Preferably said element of a damping layer is elastically deformable.

According to another aspect the invention relates to a damping layer for floors comprising a plurality of elements of a damping layer according to the present invention, arranged side by side to each other.

According to another aspect the invention relates to a floor comprising:

- a substrate (typically compact);

- a surface layer arranged above the substrate and comprising a walkable surface and

- a damping layer for floors according to the present invention and interposed between the substrate and the surface layer.

Preferably said surface layer is a synthetic turf layer.

According to another aspect the invention relates to a production process of an element of a damping layer according to the present invention, the process comprising:

- providing a mold counter-shaped to said element of a damping layer;

- inject a melted polymeric material into the mold;

- extracting from the mold said polymeric material hardened to make said element of a damping layer.

Preferably said polymeric material is polypropylene.

According to the Applicant, the presence, for each supporting element, of at least two connecting arms gives to the resulting damping layer the desired damping and/or in general mechanical response properties. In fact, for example in the structure described in WO 2011/036600 A2, the presence of one and only one connecting element of the supporting element to the frame generates a strong asymmetry (or anisotropy) of the mechanical response to the stresses. In the present invention, the presence of at least two arms gives a greater uniformity of response to the stresses (in particular a greater uniformity of absorption of impacts), for example as the direction of the latters varies.

Furthermore, the presence of at least two arms gives to the elements which constitute the damping layer a greater sturdiness with respect to a structure with only one connecting element for each supporting element, as the stresses and the relative elastic deformations are distributed on at least two arms. This results in a capacity of withstanding more intense stresses and/or a greater resistance to wear.

Moreover, the element of the damping layer for floors thus shaped, being provided with a frame with through openings, with a plurality of supporting elements and with a plurality of connecting arms, allows the correct water drainage as this conformation provides at all levels the presence of through openings which separate the aforesaid components.

The present invention in one or more of the aforesaid aspects can have one or more of the following preferred features.

Preferably said arms (including a first and a second node) are elastically deformable. In this way the arms are an active part of the damping response of the element of a damping layer.

In an embodiment said plurality of supporting elements comprises (consists of) a first and a second plurality of supporting elements, wherein said first plurality defines a first portion of said second face and wherein said second plurality defines a second portion of said second face, said second portion of the second face being closer to the first face with respect to said first portion of the second face. In this way, in absence of stresses, only the first plurality of supporting elements is resting on the surface on which the element of damping layer rests (e.g. the underlying substrate or the impermeable layer), while the supporting elements of the second plurality remain lifted from the supporting surface. In case of stresses, first the element of damping layer reacts elastically due to the supporting elements of the first plurality. As a result of this elastic reaction, the supporting elements of the second plurality approach (e.g. lowering themselves) the supporting surface. In case of sufficiently high stresses, the supporting elements of the second plurality come into play as a result of their contact with the supporting surface. In this way the element of a damping layer has a damping response variable as a function of the undergone stresses.

Preferably, said first and/or second face (or said first portion and/or said second portion of said second face) is/are flat, more preferably they are parallel to each other. In this way the resulting damping layer is easily conformable to the flat floors (even if inclined).

Preferably the element of the damping layer has a reference direction which goes from the first to the second face, more preferably perpendicular to said first and/or second face (or to said first portion and/or said second portion of said second face). This reference direction, in use, typically coincides with the geographical vertical or, more generally, with the normal to the walkable surface.

Preferably said plurality of arms contains at least three arms. In this way the uniformity of the mechanical response and/or the sturdiness is further improved.

Preferably said plurality of arms contains no more than four arms, more preferably it contains three and no more than three arms. The Applicant has in fact observed that this number of arms is optimal for supporting the thrust, as well as for making the damping layer sturdier, while keeping it simple and light.

Preferably each arm has at a first end a first connecting node to the frame and at a second end, opposite to the first one, a second connecting node to the respective supporting element. In this way the connecting arm fulfils the function of connecting the respective supporting element to the frame.

Preferably said second connecting nodes are distributed along a perimeter extent of said respective supporting element. In this way it is achieved an efficient distribution of the stress on the respective supporting element.

Preferably said second connecting nodes are distributed mutually equidistant along said perimeter extent of the respective supporting element. In this way it is possible to uniformly distribute the stress impressed by the user.

Preferably said arms have oblique longitudinal extent with respect to said reference direction. In this way it is enhanced the flexion of the arms for damping the impacts. Preferably a plane containing the reference direction (i.e. typically vertical) and passing through a first node and through a geometric centre of the respective supporting element, it does not pass also through a second node of the respective supporting element. In this way, the absorption of the impacts can be facilitated by an elastic rotation of the supporting elements around the reference direction through elastic torsion of the ensemble comprising the arms and the respective supporting element.

Preferably said arms are mutually converging going from the first to the second face. In this way it is facilitated the elastic deformation of the arms and it is reduced the supporting surface of the supporting elements.

Preferably said arms are monotonically mutually converging going from the first to the second face. In this way it is avoided the formation of undercuts, thus simplifying the production of the element of damping layer by molding (e.g. by injection).

Preferably said arms have an extent in the shape of a helicoidal segment (more preferably of conical helicoidal segment), more preferably the respective axes of said helicoidal segments are parallel to each other, even more preferably said respective axes are parallel to the reference direction. In this way it is favoured the elastic torsion of the ensemble comprising the arms and the respective supporting element. Preferably a cross-section of said arms tapers going from the first to the second face. In this way the arms respond to the stress with a progressive increasing deformation from the first to the second face, enhancing the dynamics and/or the control of the overall response to the stresses.

Preferably each arm has one or more ribs along a longitudinal extent. Preferably a cross-section of the arm has a polygonal shape. In this way it is limited the section of the arms while ensuring the desired elasticity.

Preferably said arms are equal to each other. In this way the deformation undergone by the arms is the same.

Preferably said arms are rotationally symmetrical (of order equal to the number of the arms) with respect to an axis parallel to said reference direction and passing through a geometric centre of the respective supporting element. In this way it is conferred the desired uniformity of response.

Preferably said supporting elements have a circular shape, even more preferably a solid disk shape. In this way it is more efficient the distribution of the stresses.

Preferably said supporting elements have a thickness (along said reference direction) greater than or equal to 1 mm, more preferably greater than or equal to 2 mm, and/or less than or equal to 5 mm, more preferably less than or equal to 4 mm. Preferably said supporting elements have a main dimension on said second face greater than or equal to 5 mm, more preferably greater than or equal to 7 mm, and/or less than or equal to 20 mm, more preferably less than or equal to 15 mm. In this way the supporting element is sturdy and suitable for supporting the impressed stresses.

Preferably said supporting elements are arranged according to an ordered spatial sequence, even more preferably according to a matricial scheme (rows and columns). In this way, the second supporting face, which they constitute, is consistent and sturdy, avoiding, for example, areas of thickening and/or of lack of the supporting elements.

Preferably, said supporting elements are mutually separated at the second face (i.e. there are no elements connecting them at the second face). In this way the stresses can be independently subdivided on each one of them.

Preferably said frame has a reticular structure (e.g. made of nodes and arms), more preferably with a two-dimensional extent (neglecting the thickness of the elements of the frame themselves). In this way it is favoured the elastic deformation and it is limited the weight and the use of material, while ensuring the necessary sturdiness. Furthermore, the reticular structure guarantees an optimal water outflow.

Preferably said frame comprises a plurality of equal elements arranged side by side and mutually contiguous according to a scheme (more preferably a matricial scheme), wherein each element of the frame comprises at least a through opening. Preferably said elements of the frame have a circular shape, more preferably a ring shape. In this way it is possible to achieve a sturdy reticular structure with a high presence of voids in order to facilitate the correct rainwater drainage. Preferably each element of the frame corresponds to a respective supporting element, wherein an axis passing through a geometric centre of the element of the frame and parallel to the reference direction, also passes through a geometric centre of the supporting element. In this way the stresses are efficiently transferred.

Preferably said frame (e.g. the elements of the frame) has a thickness greater than or equal to 0.5 mm, more preferably greater than or equal to 1 mm, and/or less than or equal to 4 mm, more preferably less than or equal to 3 mm. In this way the reticular structure is sturdy and suitable for supporting the surface layer of the floor.

Preferably a distance between two geometric centres of two adjacent supporting elements is greater than or equal to 10 mm, more preferably greater than or equal to 15 mm, and/or less than or equal to 30 mm. In this way the spacing between the supporting elements is adequate to withstand the impressed stresses, also creating a second compact and structurally resistant supporting face.

Preferably a distance between the first and the second face is greater than or equal to 5 mm, more preferably greater than or equal to 7 mm, and/or less than or equal to 40 mm, more preferably less than or equal to 30 mm. In this way it is facilitated the damping effect.

Preferably the element of a damping layer is a single piece. In this way it can be produced by a single molding process, for example injection molding.

Preferably, the element of a damping layer is made of polymeric material, more preferably in a single polymeric material, for example polypropylene.

Preferably the element of a damping layer is modular. In this way the damping layer can be made by joining a suitable number of equal modules as the surface to be covered varies.

Preferably said substrate is in concrete or clay ground.

Preferably said floor comprises a layer of impermeable material arranged immediately above said substrate. In this way it is facilitated the correct lateral water drainage.

Brief description of the drawings

The features and the advantages of the present invention will be further clarified by the following detailed description of some embodiments, presented as a non-limiting example of the present invention, with reference to the attached figures, in which: Figure 1 shows a perspective view of an element of a damping layer for floor according to the present invention;

Figure 2 shows a further perspective view of the element of figure 1 ;

Figure 3 shows a side view of the element of figure 1 ;

Figure 4 shows a top view of the element of figure 1 ;

Figure 5 shows a bottom view of the element of figure 1 ;

Figure 6 shows a scheme of a floor according to the present invention;

Figure 7 shows a side view of a further embodiment of the element of a damping layer for floor according to the present invention.

Detailed description of some embodiments of the invention

In the figures with the reference number 1 it is indicated an element of a damping layer 203 for floors 200 according to the present invention.

The element 1 of the damping layer comprises a frame 2 provided with through openings 3, the frame 2 forming a first face 4 (discontinuous), a plurality of supporting elements 5 which form a second face 6 (discontinuous) opposite to the first face 4 and, for each supporting element 5, a plurality of arms 7 which connect each supporting element 5 to the frame 2.

Preferably, the element 1 of the damping layer is elastically deformable.

Exemplarily the first 4 and the second face 6 are flat and are parallel to each other. Preferably the element 1 has a reference direction 100 which goes from the first 4 to the second 6 face, exemplarily perpendicular to the first 4 and to the second 6 face. Exemplarily, the plurality of arms consists of three arms 7.

Exemplarily each arm 7 has, at a first longitudinal end, a first connecting node 80 to the frame 2 and at a second longitudinally opposite end a second connecting node 81 to the respective supporting element 5.

As exemplarily shown (Fig. 4), the second connecting nodes 81 are arranged along a perimeter extent of the respective supporting element 5.

Exemplarily, the second connecting nodes 81 are distributed mutually equidistant along the perimeter extent of the respective supporting element 5.

Exemplarily the arms 7 have an oblique longitudinal extent 9 with respect to the reference direction 100.

Exemplarily a plane containing the reference direction 100 and passing through the first node 80 and through the geometric centre 90 of the respective supporting element 5, it does not pass also through the second node 81 of the respective supporting element 5. In other words, the arms do not rest on any vertical plane passing through the centre 90 of the supporting element.

Exemplarily, the arms 7 are monotonically mutually converging going from the first 4 to the second 6 face. In other words, the ensemble constituted by the arms tapers going from the first to the second face, for example it has substantially truncated- conical shape (Figure 3).

Exemplarily the arms 7 have a longitudinal extent 9 in the shape of a helicoidal segment of conical helix (fig. 3), and the respective axes of the helicoidal segments are parallel to each other and parallel to the reference direction 100.

Exemplarily the cross-section of the arms 7 tapers going from the first 4 to the second 6 face. Exemplarily each arm 7 has four ribs 8 along the longitudinal extent 9. Preferably a cross-section of the arm 7 has a polygonal shape, for example it has an irregular rhomboidal shape.

Exemplarily the arms 7 are between each other with rotational symmetry of order three with respect to the axis 102.

Exemplarily the supporting elements 5 have a circular solid disk shape having extent parallel to the second face (the second face 6 is defined by the outer surface of the supporting element).

Exemplarily, the supporting elements 5 have a thickness S1 (along the reference direction 100) equal to 3 mm and a diameter D (main dimension) equal to 9 mm. Exemplarily, the supporting elements 5 are arranged according to a regular matricial scheme (rows and columns).

Exemplarily, the frame 2 comprises a plurality of annular elements 10 equal to each other, arranged side by side and mutually contiguous according to a regular matricial scheme, wherein each annular element 10 comprises a through opening 3. Exemplarily each element 10 of the frame 2 corresponds to a respective supporting element 5, wherein an axis 102 passing through a geometric centre 91 of the element 10 of the frame and parallel to the reference direction 100, also passes through the geometric centre 90 of the supporting element 5.

Exemplarily the frame 2 (e.g. the elements of the frame 10) has a thickness S2 equal to 2 mm.

Exemplarily a distance d between two geometric centres 90 of two adjacent supporting elements 5 is equal to 20 mm. Exemplarily a distance H between the first 4 and the second 6 face is equal to 10 mm.

Exemplarily the element 1 of a damping layer is a single piece.

The floor 200, shown in figure 6, preferably comprises a compact substrate 201 (e.g. in clay ground or in concrete), a surface layer 202 (e.g. an artificial turf layer, typically provided with an infill material - not shown - between the artificial turf strands) arranged above the substrate 201 and comprising a walkable surface 210, and a damping layer 203 interposed between the substrate 201 and the surface layer 202. The damping layer 203 is made by approaching and attaching/fixing of a suitable number of modular elements 1 , typically (but not necessarily) arranged with the first face 4 facing upwards and with the reference direction 100 arranged perpendicularly to the walkable surface (i.e. typically vertical).

Exemplarily the floor 200 comprises a layer of impermeable material 204 interposed between the substrate 201 and the damping layer 203.

In use, when the surface layer 202 undergoes an impact, the frame 2 undergoes a thrust towards the supporting elements 5 (typically downwards). The damping layer reacts to this stress with an elastic deformation, which comprises an elastic flexion (e.g. progressive) along the longitudinal extent of the arms 7, and/or near the connecting nodes 80 and 81 , and/or at the frame. Furthermore, the supporting elements 5 can move respect each other following these elastic deformations.

Without being limited to any theory, the Applicant considers that the arms 7 are structured in order to cushion part of the stress through their elastic deformation and in order to transfer part of the stress to the respective supporting element 5. The arms 7, also thanks to their extent in the shape of a helicoidal segment and their rotational symmetry, transfer the stress to the respective supporting element 5 according to a direction with at least a component tangential to the latter, subjecting it to torsion. Typically, and exemplarily, this tangential component of the force rest on a plane identified by the second supporting face 6. In this way the thrust, typically mainly vertical, impressed by the user, is damped and dissipated, through an elastic deformation of the damping layer (undergone by its constitutive elements such as frame, arms and connecting nodes) and a rotation of the respective supporting element 5.

The element 1 can be produced by injection molding, which provides the removal of the element 1 from the mold, avoiding complex procedures, thanks to the absence of undercuts.

Figure 7 shows a further embodiment of the element 1 , in which the plurality of supporting elements is subdivided into a first and second plurality of supporting elements 5 and 5'. The supporting elements 5' have an increasing in thickness (in figure shown in exaggerated way for illustrative purposes) with respect to the thickness S1 of the supporting elements 5. The increasing in thickness is preferably greater than or equal to 0.1 mm and/or less than or equal to 1 mm. Exemplarily the increasing in thickness is equal to 0.5 mm.

In use, in absence of stresses, only the supporting elements 5’ are resting on the surface on which the element 1 of damping layer rests (for example, the underlying substrate 201 or the impermeable layer 204), while the supporting elements 5 remain lifted from the supporting surface. In case of stresses, first the element 1 of damping layer reacts elastically due to the supporting elements 5'. As a result of this elastic reaction, the supporting elements 5 are lowered towards the supporting surface. In case of sufficiently high stresses, the supporting elements 5 come into contact with the supporting surface. In this way the element 1 has a damping response variable as a function of the undergone stresses.

In an alternative embodiment, not shown, the arms may be four.

In alternative embodiments, not shown, the arms may be rectilinear.

In alternative embodiments, not shown, the arms may have a longitudinal extent along the reference direction 100, or the longitudinal extent of the arms may entirely rest on a plane passing through the reference direction 100 and the geometric centres 90, 91 of the respective supporting element and of the respective element of the frame.