Vibration damping device of sports racket with frame and chord plate

Abstract

Described is a damping device (10) for a sports racket (R), in particular a tennis racket, comprising: a central portion (12) arranged to be inserted between a pair of parallel strings (S1) of a string plate (P) of the racket (R) so as to be in contact with at least said pair of parallel strings (S1); and a pair of outer portions (14, 16) protruding from opposite sides of the central portion (12) such that these outer portions (14, 16) are arranged on opposite sides of the chord plate (P) in a state in which the device (10) is mounted on the chord plate (P). The central portion (12) and the outer portions (14, 16) are of a three-dimensional grid structure comprising a plurality of elementary cells arranged in three spatial directions, the elementary cells being configured to have at least one degree of freedom with respect to each other in one of the three spatial directions, in operation, due to their elastic response, at least a portion of the kinetic energy generated by the vibration of the string plate (P) and the racket (R) as a whole is dissipated.

Description

Field of the Invention

[0001] The present invention generally relates to the field of sports rackets, which include a frame with a handle and a string bed carried by the frame.

[0002] More specifically, the present invention relates to a damping device or anti-vibration device for a racket of the above type, that is, a device arranged to be attached to the racket strings for attenuating the vibrations generated due to the impact of a game ball on the racket string bed.

[0003] In the following description, for convenience, a tennis racket will be taken as an example of the sports racket for which the damping device of the present invention is targeted. However, the present invention is not limited to the field of tennis rackets and can also be applied to other types of sports rackets as long as they include a frame and a string bed carried by the frame. Background Art

[0004] When a tennis racket hits a ball, the racket vibrates due to the elastic response of the racket frame and the string bed. The vibrations caused by the collision with the ball usually have a multi-peak profile, which is generated by the combination of the elastic response (bending) of the racket frame and the elastic response of the string bed.

[0005] Lower frequency vibrations (e.g., in the range of 120 Hz to 200 Hz) are the result of the bending of the racket frame and do not produce any audible sound, although they are transmitted to the hand and arm of the tennis player in the form of mechanical stress. Higher frequency vibrations (e.g., in the range of 500 Hz to 700 Hz) are the result of the elastic response of the string bed and are perceived as high-pitched sounds, like a "thump". According to the latest report of the International Tennis Federation (ITF) and other sources, among the 87 million tennis players globally, approximately 67% to 75% of tennis players use damping devices installed on the racket to reduce the impact of racket vibrations.

[0006] Therefore, various solutions have been envisioned to reduce the vibrations of the tennis racket frame and the string bed, including damping devices or anti-vibration devices, which are designed to be applied to the frame or the string bed of the racket. The most common damping devices are those designed to be applied to the string bed, usually called "string dampeners", and more specifically those in the shape of buttons, usually called "button dampeners".

[0007] Typical examples of button dampeners are shown in US4776590 and US4609194, which are basically formed by a cylindrical viscoelastic material block that will be inserted between two adjacent parallel strings of the racket string bed, usually located in the lower part of the string bed, that is, the part of the string bed close to the racket handle. When installed on the string bed, the dampener usually has a spherical shape.

[0008] US4609194 also discloses a shock absorber which includes a central portion intended to be inserted between two pairs of adjacent parallel strings of a string plate, and a pair of outer portions projecting from opposite sides of the central portion and contacting the string plate in the mounted state of the shock absorber.

[0009] According to the preamble of the appended independent claim 1, a shock-absorbing device is known from EP0291434. According to this known solution, the outer portions of the shock-absorbing device are made integral with the central portion, and each outer portion includes a pair of discs, namely an inner disc with a larger diameter and an outer disc with a smaller diameter.

[0010] US4732383 discloses an alternative version of a string shock absorber. This type of shock absorber is commonly referred to as a "worm shock absorber" and consists of an elastic rod or strip for absorbing vibrations. The rod or strip is made of a multi-layer material with different elastic properties, in particular, the density of the inner layer is higher than that of the outer layer. The ends of the rod or strip are connected to the string plate of the racket by suitable means (such as hooks or loops) or by a plurality of outer ribs spaced apart from each other and extending transversely, as described in EP0497561.

[0011] As is well known, each racket has its own vibration curve, which depends on the overall stiffness of the frame as well as the type and tension of the string plate. Therefore, the range of possible vibration modes is very wide. Some current shock-absorbing devices can theoretically adapt to different degrees of shock absorption. However, their production process does not allow the production of customized devices, i.e., devices configured according to the specific needs of each player, at a reasonable cost. This fact is confirmed by the devices currently available on the market, which are produced in a standardized manner.

[0012] This represents an obvious limitation of the known solutions for vibration damping devices, as several studies (e.g., "Dynamics of a String-Bed Dampener on Tennis Rackets", Mohr et al., Head Sport GmbH) have shown both theoretically and experimentally that the mass of each vibration damping device should be calibrated according to a specific racket configuration (i.e., a specific combination of frame and string bed) to provide optimized damping conditions. The same studies have shown that the degree of influence of the vibration damping device on the vibration frequency goes beyond what is sometimes mistakenly considered as simple noise reduction or merely an aesthetic add-on to the racket. In fact, an in-depth analysis of the racket's vibration characteristics shows that the frequency spectrum is indeed significantly altered by the vibration damping device. For example, the study by Mohr et al. has accurately determined that by changing the mass of the vibration damping device, the vibration mode of the racket has changed significantly. Therefore, the mass of the vibration damping device is crucial for the amplitude and frequency of the racket's vibration mode and cannot be less than certain values: for example, according to the study by Mohr et al., the mass of the vibration damping device cannot be less than 2.5 grams. This limitation is actually determined by the operating principle of this type of vibration damping device: the main function of the device is actually to attenuate vibrations by absorption, transferring kinetic energy to the molecular structure of the material that makes up the device and ultimately generating heat (e.g., as described in the aforementioned document US4609194). Summary of the Invention

[0013] Accordingly, an object of the present invention is to provide a vibration damping device that is improved relative to the above-mentioned prior art, in particular a vibration damping device whose damping ability is not completely or mainly determined by the mass of the device.

[0014] Another object of the present invention is to provide a vibration damping device that can be "customized" in a cost-effective manner, i.e., adapted to the specific vibration curve of each racket.

[0015] The present invention fully achieves the above and other objects through the vibration damping device as described in independent claim 1 below.

[0016] Other advantageous features of the present invention are defined in the dependent claims, and the subject matter of these claims should be understood as an integral part of this specification.

[0017] Broadly speaking, the present invention is based on the following concept: to provide a damping device of a type which includes a central portion arranged to be inserted between a pair of parallel strings of a racquet string bed so as to be in contact with at least said pair of parallel strings, and a pair of outer portions formed as a three-dimensional structure and protruding from opposite sides of the central portion such that, in the state where the device is mounted on the string bed, the outer portions are arranged on opposite sides of the string bed, wherein the outer portions are made as a grid structure formed by a plurality of basic units arranged in three spatial directions, said basic units being configured such that at least one of them has at least one degree of freedom with respect to at least another basic unit in one of the three spatial directions, so that in operation at least a part of the kinetic energy generated by the vibrations of the string bed and the racquet as a whole is dissipated due to the elastic response of the basic units.

[0018] With such a configuration, the mass of the damping device of the present invention is significantly lower than the mass of a conventional button damper (as described above, typically about 2.5 grams), while still being able to effectively dissipate the vibrations generated by the impact of the racquet string bed with the ball due to the elastic response of the grid structure forming the outside of the device. Moreover, by appropriately changing the configuration of the grid structure forming the outside of the device (in terms of geometry, dimensions and / or the spatial arrangement of the basic units forming said structure), it is possible each time to adapt the response of the damping device to the specific vibration profile of the racquet in question.

[0019] Brief Description of the Drawings

[0020] Further features and advantages of the present invention will become apparent from the following detailed description, which is given by way of non-limiting example only with reference to the drawings, in which:

[0021] - Figure 1 is a perspective view showing a part of a tennis racquet, and a damping device according to an embodiment of the present invention is mounted on the string bed of the racquet;

[0022] - Figure 2 is Figure 1 a plan view of the mounting state of the damping device in

[0023] - Figure 3 is Figure 2 a view similar to

[0024] - Figure 4 is Figure 1 a side view of the damping device in

[0025] - Figure 5 is Figure 1 a side view of the damping device in the mounted state on the string bed of a tennis racquet;

[0026] -Figure 6 is a perspective view of a component including three Figure 1 vibration damping devices of the type shown, connected in series with each other;

[0027] - Figure 7 is a side view of a vibration damping device according to another embodiment of the present invention, which is different from the Figures 1 to 5 vibration damping device in that the central part of this device has no side walls;

[0028] - Figure 8 is Figure 7 a plan view of the vibration damping device of

[0029] - Figure 9 shows in perspective a further embodiment of the vibration damping device according to the present invention, in which the outer part of the device has a substantially hemispherical shape;

[0030] - Figure 10 shows in perspective a series of embodiments of the vibration damping device according to the present invention, in which the outer part of the device has a substantially cylindrical or button-like shape; and

[0031] - Figure 11 shows Figure 10 a plan view of one of the two outer parts of each vibration damping device in

[0032] Detailed description

[0033] First, referring to Figures 1 to 3 , a sports racket, particularly a tennis racket, is generally denoted by R, which is only partially shown and includes, in a manner known per se, a frame F equipped with a handle (not shown) and a string plate P. The string plate P has a plurality of mutually parallel strings S1 (hereinafter referred to as longitudinal strings) and a plurality of mutually parallel strings S2 perpendicular to the strings S1 (hereinafter referred to as transverse strings).

[0034] The vibration damping device (hereinafter, for convenience, simply referred to as the vibration damping device) is generally denoted by 10 and is mounted on the string plate P of the racket R, particularly between two central longitudinal strings S1 and below the lowest transverse string S2.

[0035] The vibration damping device 10 is made as a single component and mainly includes a central part 12 and a pair of outer parts 14 and 16 protruding from opposite sides of the central part 12. Thus, in the state where the vibration damping device is mounted on the string plate P, the outer parts 14 and 16 are arranged on opposite sides of the string plate P. The central part 12 is configured to be insertable between a pair of parallel strings of the string plate P, for example - as Figures 1 to 3Inserted between the central longitudinal strings S1 shown so as to be in contact with this pair of strings, and possibly - as Figures 1 to 3 shown - in contact with the transverse string S2, in particular with the lowest transverse string S2 (i.e., the transverse string S2 closest to the handle of the racket R). The outer portions 14 and 16 have a larger surface area in a plan view (as Figure 2 and Figure 3 shown) than the central portion 12, thus "covering" the area of the string plate P surrounding the central portion 12 and forming a pair of grooves 18 ( Figure 4 and Figure 5 ), into which the above two parallel longitudinal strings S1 of the string plate P can be inserted, thus ensuring a stable mounting of the damping device 10 on the string plate P. In addition, the outer portions 14 and 16 preferably have the same mass.

[0036] According to the invention, the central portion 12 and the outer portions 14 and 16 are formed of a three-dimensional grid structure comprising a plurality of basic units which are arranged in a repetitive manner in three spatial directions and interconnected.

[0037] The arrangement of the basic units in space, called "mapping", can adopt different configurations. For example, it can adapt to primitive solids such as cubes, parallelepipeds, cylinders or spheres, or to irregular solids.

[0038] Thus, the properties of these structures (mechanical, thermal, acoustic, etc.) are determined by design parameters such as the geometry of the basic unit, the thickness of the arms, or the arrangement of the basic units in space, to name but a few. As for the type of lattice, it can be periodic, aperiodic, or random; furthermore, it may consist of arms and nodes, regular surfaces, or triply periodic minimal surfaces (also known as TPMS). For periodic lattice structures (such as TPMS), the type of basic unit determines most of the properties of the structure, including mechanical properties. In particular, there has recently been a growing interest in so-called "structural materials" or "metamaterials" (for example, see the article 'Mechanical properties of 3D printed polymeric cellular materials with triply periodic minimal surface architectures' in Materials & Design, vol. 122, 15 / 05 / 2017, p. 255 - 267 and the article "Effect of unit cell topology on the tensile loading responses of additively manufactured CoCrMo triply periodic minimal surface sheet lattices" in Materials & Design, vol. 206, 08 / 2021, 109778). In summary, these are engineering lattice structures that enable targeted and controllable physical responses, such as the thermal, electromagnetic, acoustic, or mechanical properties of components. By this method, it is possible to modify the behavior of a component by changing its geometry at the mesoscale rather than by changing the material (i.e., by changing the microstructure).

[0039] Lattice structures obtained by additive manufacturing (or 3D printing) techniques are typical examples of metamaterials. By controlling the lattice design parameters (such as the thickness of the arms or the size and geometry of the basic unit), it is possible to create structures with predefined mechanical properties. Furthermore, by changing the parameters within the same lattice, regions with different mechanical responses can be obtained depending on the variation of said parameters. Advantageously, due to additive manufacturing, these structures are made of the same base material and are single components, and can achieve a level of geometric complexity that cannot be replicated by traditional manufacturing techniques, especially so-called subtractive techniques, where the component to be manufactured is obtained by removing material from a semi-finished product. In fact, while it is certainly possible to produce simple lattices using traditional manufacturing techniques (such as CNC machining, welding, or casting), additive manufacturing can obtain highly complex structures in a single component in a more cost-effective manner.

[0040] The grid structure forming the central portion 12 and the outer portions 14 and 16 of the damping device 10 is appropriately configured so as to optimize the response of the damping device itself based on the vibration profile of the racket R. Advantageously, knowing the specific vibration profile of the racket R, which depends, as described above, on the specific characteristics of the frame (material, geometry, mass, etc.) and the specific characteristics of the stringbed (material, tension, etc.), it is possible to produce a damping device 10 with a three-dimensional grid structure optimized for that specific racket.

[0041] The three-dimensional grid structure of the damping device 10 is further configured such that their cells are able to move relative to each other in at least one of the three spatial directions, thereby dissipating at least a portion of the kinetic energy generated by the vibrations of the stringbed P and the racket R as a whole during operation due to their elastic response. More generally, the three-dimensional grid structure of the damping device 10 is configured such that at least one basic cell is able to move relative to at least another basic cell in at least one of the three spatial directions. Thus, the physical principle on which the damping device of the present invention is based is at least partially different from that of the damping devices of the prior art, which, as described above, must have a minimum mass to produce a measurable damping effect. In fact, due to the partial mobility of the basic cells relative to each other, the damping device is able to dissipate vibrations through the elastic response of its three-dimensional grid structure, rather than by absorbing kinetic energy and generating heat as in known damping devices.

[0042] Thus, while in known damping devices a reduction in the mass of the damping device represents a drawback, in the damping device according to the present invention, since the three-dimensional grid structure of the damping device defines a series of voids within the volume of the damping device itself, the mass of the damping device is lower than that of a conventional damping device for the same volume, which represents a twofold advantage: in fact, reducing the mass of the damping device means on the one hand reducing the mass of the entire racket, thus - as is well known - delaying player fatigue and improving performance, and on the other hand minimizing the displacement of the center of mass of the racket due to the presence of the damping device.

[0043] Furthermore, by using a three-dimensional grid structure, the need to use different materials with different elastic responses is avoided, although this is not excluded. In fact, according to the previously introduced concept of "metamaterials", by adjusting the geometry, dimensions and density of the three-dimensional grid structure and its constituent cells, it is possible to precisely control the response of the structure to certain mechanical stresses or vibration frequencies, thus achieving the same results as using different materials, but with a lower complexity of the production process of the damping device.

[0044] Another advantage of using a three-dimensional grid structure lies in its improved aerodynamic response. In fact, it is well known that a three-dimensional grid structure has less aerodynamic drag than a solid structure (such as the solid structure of a traditional damping device) and can be advantageously and precisely designed to minimize such drag. The lower aerodynamic drag of the damping device obviously also results in a lower aerodynamic drag of the entire racket, thus improving the performance of the racket.

[0045] The three-dimensional grid structure of the damping device 10 is preferably made into a TPMS structure. Due to the design freedom provided by the additive manufacturing process, in fact, a theoretically infinite number of damping devices can be produced, and the additional "customization" cost can be negligible: Therefore, a properly constructed damping device can be produced at a competitive cost, which is based on a specific racket, taking into account the type of strings used and their tension, and may also be based on the personal characteristics of a specific player.

[0046] As described above, the three-dimensional grid structure characterizing the damping device 10 of the present invention is formed by a plurality of basic units, which are repeated and arranged in an ordered or disordered manner in three spatial directions. In particular, the TPMS structure is derived from the so-called implicit geometry: for example, the gyro line is one of the implicit geometric categories of the TPMS structure - derived from a given equation - which is based on the basic units arranged in three spatial dimensions. Since the implicit geometry can be defined as a field (in the physical sense of the term), it can be modified by other fields or combined with them. This property allows for the effective combination of different geometries, thus creating very complex geometric structures. Advantageously, another property (such as the vibration field generated by finite element simulation (FEA)) can also be used to modify the field (i.e., its geometry or topology) of this three-dimensional grid structure. The method just described is relatively new, also because there is software that can be actually implemented. This method is defined by the term "field-driven design", which, in short, is the engineering concept on which the design of this damping device is based. Therefore, by utilizing "field-driven design", variable structures can be generated, that is, structures that vary within the same volume (in this case, the damping device) in three spatial dimensions, thus assuming different density values, the number of basic units, and the shape of the basic units themselves according to their position relative to a given reference point (for example, the centroid of the damping device). By carefully designing the parameters of these structures, a differentiated mechanical response can be achieved in a single damping device. This ultimately makes it possible to design a damping device that can selectively respond to different vibration frequencies, thus being able to effectively attenuate vibrations with different frequencies and amplitudes, which particularly interfere with the multi-modal vibration profile of the racket shown in the preamble part of this specification and act on all its main components.

[0047] Referring again to Figures 1 to 3 and Figure 4 and Figure 5, the outer portions 14 and 16 of the damping device 10 preferably have a symmetric configuration relative to the intermediate plane of the damping device, which is parallel to the chord plate itself in the state of being mounted on the chord plate P. Specifically, according to the embodiments shown in these figures, the outer portions 14 and 16 of the damping device 10 have a substantially hemispherical shape, the radius of which, for example, ranges between 5 mm and 20 mm. In addition, according to Figures 1 to 5 the embodiment shown, the central portion 12 of the damping device 10 includes a peripheral wall 20 that surrounds the first two innermost units forming the grid structure of the damping device 10. The thickness of the peripheral wall 20, for example, ranges between 0.5 mm and 2 mm. In addition, the planar profile of the peripheral wall 20 can be square, as Figures 1 to 5 shown in the embodiment of, but can also have a planar profile of any other shape, such as rectangular, circular, oval, etc. Generally, the geometry (i.e., shape and size) of the peripheral wall 20 should be such that when the damping device 10 is mounted on the chord plate P, the peripheral wall 20 contacts the strings of the racket.

[0048] The percentage of the volume occupied by the grid structure relative to the total volume of the damping device 10 is preferably between 15% and 90%. In addition, the three-dimensional grid structure can be composed of a fixed or variable number of basic units in each of the three spatial directions. Finally, the basic units of the three-dimensional grid structure can be arranged relative to a fixed origin according to Cartesian mapping (recalling the definitions introduced earlier) (thus defining the dimensions of the basic units in the x, y, z coordinates, expressed in linear units, such as millimeters), cylindrical mapping (defining the size of the basic units in the coordinates r, θ, z, where the θ coordinate is expressed in angular units, such as radians), or spherical mapping (defining the size of the basic units in the coordinates r, θ, where the coordinate θ and are expressed in angular units, such as radians). It is worth noting in this regard that the dimensions of the basic units can also be defined as relative values rather than absolute values, thus indicating the total number of basic units in each of the three directions relative to the volume (or "design space") they will occupy. This mapping may also be of an irregular shape, in which case multiple origins may coexist within the same volume, characterizing different parts of the same three-dimensional grid structure, thus creating a three-dimensional grid structure that conforms to the volume they occupy.

[0049] For example, in Figures 1 to 5 the embodiment of, the volume occupancy of the three-dimensional grid structure of the damping device 10 is 25%, and the number of basic units is equal to 6 (relative to the total volume of the damping device). As described above, each of the three directions r, θ, and has a spherical mapping, and the origin is located at the centroid of the damping device.

[0050] However, alternatively, as described above, the three-dimensional grid structure may have variable constitutive parameters in different directions of the reference system in order to achieve a specific mechanical response along these directions.

[0051] As Figure 5 shown, the damping device 10 is advantageously configured such that, in the state of being mounted on the chord plate P, the protruding portions 14 and 16 do not contact the chord plate P, except for the two longitudinal chords S1 in contact with the central portion 12. Therefore, it can move relative to the chord plate P in at least one spatial direction, that is, at least in a direction perpendicular to the plane of the chord plate itself.

[0052] Figure 6 shows a damping device 110 obtained by connecting a plurality of Figures 1 to 5 damping devices 10 of the type shown together. In this case, for each pair of adjacent damping devices 10, a connecting portion 22 is provided, which is formed, for example, by a simple strip of material. The connecting portion 22 connects the outer portion 14 of one damping device 10 to the outer portion 14 of another damping device 10, or connects the outer portion 16 of one damping device 10 to the outer portion 16 of another damping device 10. In this way, a damping device capable of contacting four, five or more strings simultaneously is obtained, and thus has enhanced damping ability.

[0053] Figure 7 and Figure 8 shows another embodiment of the damping device, labeled 210, which has the same construction as the Figures 1 to 5 damping device 10, and its basic difference from the Figures 1 to 5 damping device 10 is only that the central portion 12 has no peripheral wall. Therefore, in the state where the damping device is mounted on the chord plate, the grid structure of the central portion 12 in contact with the string is the same. For the rest, the content described above with reference to Figures 1 to 5 still applies.

[0054] The three-dimensional grid structure can have different but functionally equivalent configurations. For example, the TPMS structure can be configured as Lidinoid, SchwartzP, SchwartzD or any other implicit geometry or a combination thereof. Figure 9 shows some non-limiting embodiments of the damping device, which are labeled 310, 410, 510, 610 and 710 respectively.

[0055] Similarly, in a further embodiment, the two outer portions of the damping device can extend in one or two spatial directions.

[0056] The shape of the damping device can have other configurations than the Figures 1 to 9 spherical shape shown. For example, as Figure 10 and Figure 11As shown, four further embodiments of the vibration damping device are presented, denoted as 810, 910, 1010, and 1110, respectively. The vibration damping device may, for example, have a generally cylindrical shape. Alternatively, the general shape of the vibration damping device may be any other primitive solid (e.g., cube, cone, prism, or a combination thereof) or an irregular solid. In short, the vibration damping device may adopt any shape, including an aesthetic feature shape (e.g., a company logo or letter), without changing the basic principle of the present invention.

[0057] In a preferred embodiment, the vibration damping device is made of an elastomeric material, particularly a thermoplastic or thermosetting elastomer. Generally speaking, the vibration damping device may be made of one or more materials, including viscoelastic materials. However, in principle, any type of material may be used, relying on the same basic principle of the present invention to produce a significant vibration damping effect.

[0058] So far, the present invention has been described with reference to some currently preferred embodiments of the present invention. It should be understood that other embodiments may be envisioned, which share the same inventive core as the embodiments described herein, as defined by the appended claims.

Claims

1. A damping device (10) for a sports racket (R), the sports racket comprising a frame (F) and a string plate (P) carried by the frame (F), the device (10) being made as a single piece, comprising: - a central part (12) adapted to be inserted between a pair of parallel strings (S1) of the string plate (P) so as to be in contact with at least the pair of parallel strings (S1), and - a pair of outer parts (14, 16) protruding from opposite sides of the central part (12) such that in a state where the device (10) is mounted on the string plate (P), the outer parts (14, 16) are arranged on opposite sides of the string plate (P), characterized in that the central part (12) and the outer parts (14, 16) are formed as a three-dimensional grid structure including a plurality of basic units arranged in three spatial directions, the basic units being configured such that at least one of them has at least one degree of freedom with respect to at least another basic unit in one of the three spatial directions, so that during operation, at least part of the kinetic energy generated by the vibration of the string plate (P) and the racket (R) as a whole is dissipated through the elastic response of these basic units.

2. The device according to claim 1, wherein the density, the number of basic units and / or the shape of the basic units of the three-dimensional grid structure is constant or variable in one or more of the three spatial directions.

3. The device according to any one of the preceding claims, wherein the outer parts (14, 16) have a symmetric configuration with respect to a middle plane of the device (10), and in a state where the device (10) is mounted on the string plate (P), the middle plane is parallel to the string plate (P).

4. The device according to any one of the preceding claims, wherein each of the outer parts (14, 16) has a hemispherical shape, in particular with a radius between 5 mm and 20 mm.

5. The device according to any one of the preceding claims, wherein the central part (12) further includes a peripheral wall (20), the peripheral wall (20) having a square, rectangular, circular, elliptical or other shaped contour in a plan view, the contour being configured to ensure contact of the peripheral wall (20) with the at least one pair of parallel strings (S1) of the string plate (P).

6. The device according to any one of the preceding claims, wherein the central part (12) and the outer parts (14, 16) are arranged and configured such that: in a state where the device (10) is mounted on the string plate (P), the outer parts (14, 16) do not contact the string plate (P), so as to be able to move relative to the string plate (P) in at least one spatial direction.

7. The device according to any one of the preceding claims, wherein the three-dimensional grid structure occupies 15% to 90% of the total volume of the device (10).

8. The device according to any one of the preceding claims, wherein the three-dimensional grid structure is made of an elastomeric material, in particular a thermoplastic elastomer or a thermosetting elastomer, or made of a viscoelastic material.

9. The device according to any one of claims 1 - 7, wherein, the three - dimensional grid structure is made of more than one material, including at least one elastomeric material or viscoelastic material.

10. The device according to any one of the preceding claims, wherein, the three - dimensional grid structure is made by 3D printing or an additive manufacturing process, in particular by a photopolymerization process, more specifically by stereolithography or DLP (Digital Light Processing) technology, or by a selective laser melting process.

11. A component comprising a plurality of devices (10) according to any one of the preceding claims, and for each pair of adjacent devices (10), a connecting portion (22) connects an external portion (14, 16) of one device (10) in the pair to a corresponding external portion (14, 16) of the other device (10) in the pair.

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