WO2017136813A1

WO2017136813A1 - Objects having improved rebound characteristics

Info

Publication number: WO2017136813A1
Application number: PCT/US2017/016677
Authority: WO
Inventors: Dries VANDECRUYS
Original assignee: Materialise N.V.; Materialise Usa, Llc
Priority date: 2016-02-06
Filing date: 2017-02-06
Publication date: 2017-08-10

Abstract

Embodiments of this application relate to three-dimensional objects having improved rebound characteristics. In some embodiments, the object may be formed from low resilience materials (7100). The three-dimensional object comprises a plurality of unit cells that form an inner mesh (202) design and an outer mesh (204, 304), wherein the inner mesh (202) and outer mesh (204, 304) are attached to each other by a plurality of connecting beams (140, 208, 310, 610).

Description

OBJECTS HAVING IMPROVED REBOUND CHARACTERISTICS

Cross-Reference to Related Application & Priority Claim

[0001] This application claims benefit of and priority to U.S. Provisional Patent Application Serial No. 62/292,292, filed February 6, 2016, which is herein incorporated by reference in its entirety for all applicable purposes.

BACKGROUND

[0002] The present invention relates to three-dimensional objects having improved rebound characteristics, and methods of making the same.

[0003] Three dimensional objects may have many characteristics, including material composition and design, which may affect resilience i.e. the ability of that object to spring back into shape after being deformed. The resilience of an object may also be referred to as the elasticity of that object. The resilience or elasticity of the object may, in turn, affect the object's "rebound" or "bounce" characteristics i.e. the object's ability to move up, back, away or the like from a surface after hitting it. Ultimately, the physics of a rebounding or bouncing object are influenced by dynamics principles, such as acceleration and momentum of the object, as well as material and design characteristics of the object.

[0004] Generally, the magnitude of the rebound or bounce of an object, such as a ball, is directly linked to the magnitude of absorption of energy by the object when hitting a surface as well as the object's elasticity. For example, an inelastic object that hits a surface may absorb all of the energy by deformation and even breakage such that the object will not bounce much or at all. On the other hand, an elastic object that hits a surface may absorb most of the energy elastically, and then bounce back off the surface when the object springs back into shape. Due to these basic principles, most objects designed to bounce are made from elastic materials, for example, materials with relatively high resilience. Many balls used in sports are made of high- quality rubber (an elastomeric material with high resilience). These balls may include tennis balls or squash balls.

[0005] The resilience or elasticity of objects and materials may be described by a stress- strain curve, which shows the relation between stress (the average restorative internal force per unit area) and strain (the relative deformation). The amount of elasticity of an object or a material may be determined by two material characteristics. The first material characteristic is a modulus, which measures the amount of force per unit area (stress) needed to achieve a given amount of deformation of the object. Generally, a higher modulus indicates that the object or material is less deformable. The second material characteristic is an elastic limit of the object or material. The elastic limit is a stress beyond which the material no longer behaves completely elastic and lasting deformation of the material will take place. In other words, beyond the elastic limit, when the stress is released, the material will elastically return to a deformed shape instead of the original shape. Examples of this phenomenon include dents, breaks, etc. Accordingly, the rebound or bounce of an object, such as a ball, may be limited by the elastic limit of that object.

[0006] It may be possible to infer the resilience or elasticity of a three-dimensional object, such as a ball, by dropping it from a known height and measuring the subsequent height of the bounce. The ratio of the rebound height to the initial drop height of the object may be determined as the "rebound resilience" of the object.

[0007] One issue with bouncing objects, such as balls, is that their bounce characteristics are often limited by material selection and by shape selection. Material selection and shape selection may in turn be dictated by available and practical manufacturing techniques. Often, the materials necessary to give such objects their bounce characteristics are relatively dense and need to be used in relatively large quantities, which makes the resulting objects heavy. Further, practical methods of manufacture may limit the range of shapes that can be made within commonly used materials.

[0008] Newer methods of manufacture, such as additive manufacturing, may allow for more complex object designs that overcome limitations of a material's characteristics. For example, whereas existing designs may rely on highly resilient materials (e.g. rubber) and simple object designs (e.g. spherical) in order to achieve high rebound or bounce, new manufacturing techniques, such as additive manufacturing, may enable objects with complex or intricate designs and made from low resilience materials to achieve similar or even improved rebound or bounce characteristics.

[0009] Accordingly, there is a need for designs for three-dimensional objects that take advantage of complex designs made possible by modern manufacturing techniques, such as additive manufacturing, in order to improve the rebound or bounce characteristics of those objects.

SUMMARY

[0010] Embodiments described herein relate to a multiple-mesh object. The multiple- mesh object may comprise a first mesh comprising a plurality of first mesh elements. Each of the first mesh elements may comprise a plurality of first mesh element segments. The multiple- mesh object may also include a second mesh. The second mesh may comprise a plurality of second mesh elements, and each second mesh element may comprise a plurality of second mesh element segments. The object may further include a plurality of connecting beams connecting at least one first mesh element segment of each first mesh element of the plurality of first mesh elements to a respective second mesh element segment of a respective second mesh element of the plurality of second mesh elements.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1A-1F depict an embodiment of a method for defining unit cells of a dual- mesh surface.

[0012] Figures 2A-2C depict an embodiment of a method for defining unit cells of a dual-mesh, spherical object.

[0013] Figure 3 A depicts an embodiment of a dual-mesh, spherical object.

[0014] Figure 3B depicts an embodiment of the dual-mesh, spherical object from Figure 3A in a compressed state.

[0015] Figures 4A-4C depict another embodiment of a dual-mesh object.

[0016] Figure 5 depicts a method of manufacturing a dual-mesh object.

[0017] Figure 6A-6G depicts an embodiment of a dual-mesh, footwear related object.

DETAILED DESCRD7TION OF CERTAIN INVENTIVE EMBODIMENTS

[0018] Embodiments of this application relate to three-dimensional objects having improved rebound characteristics. In some embodiments, the objects may be formed of relatively low resilience materials. However, it is to be appreciated that in some embodiments, objects may be formed of relatively high resilience materials as well. In some embodiments, the three-dimensional object comprises a plurality of unit cells that are formed by a first mesh and a second mesh, wherein the first mesh and second mesh are attached to each other by a plurality of connecting beams. In some embodiments, the first mesh may be an inner mesh, and the second mesh may be an outer mesh. Other embodiments relate to the design of three-dimensional objects having three or more meshes.

[0019] A "mesh" or "mesh surface" may comprise a surface itself comprising a plurality of mesh elements, e.g., a pattern of geometrical shapes. For example, a mesh may comprise a surface comprising square shapes, wherein each edge of one square-shaped mesh element connects to an adjacent square-shaped mesh element within the mesh surface. As another example, a mesh may comprise a surface of circle-shaped mesh elements, wherein each circle- shaped mesh element is connected to an adjacent circle-shaped mesh element in the mesh surface at one or more connection points, intersection points, vertices, or the like along the circumference of the circle. Many other shapes may be used to form a mesh, such as triangles, rectangles, pentagons, hexagons, octagons, and other polygons and shapes as are known by those in the art. In some embodiments, a mesh may include multiple shapes. In some embodiments, a mesh element may be flat or planar along one dimension (e.g. its length). In other embodiments, the mesh element may be curved or otherwise non-planar along its dimensions. Non-planar mesh elements may be designed to match the surface of a three-dimensional object, such as a sphere, and other objects as are known in the art. It is to be appreciated that the meshes may be positioned parallel to each other. Alternatively, meshes may be positioned to be non-parallel. In embodiments having more than two meshes, some may be parallel to each other, and others may be non-parallel to each other.

[0020] In a mesh surface, the shapes of the individual mesh elements may be formed by segments (alternatively referred to as edges or sides) that connect at vertices (alternatively referred to as connection or intersection points). The segments may be straight, such as in a polygon or polyhedron, or they may be curved, such as in a circle, ellipse, oval, stadium, arch, lens, annulus, crescent, circular segment, circular sector, Reuleaux polygon, and others as are known in the art. The segments may be relatively thin, such that the mesh is primarily open space, or they may be relatively thick, such that the mesh is primarily closed. In embodiments where the mesh comprises thin segments, the mesh may be described as a "primarily open mesh" and may have a relatively low density compared to the size of the mesh. In embodiments where the mesh comprises thick segments, the mesh may be described as a "primarily closed mesh" and may have a relative high density compared to the size of the mesh.

[0021] A mesh may be designed by starting with a surface of any shape, such as those described above, and dividing the surface into a plurality of mesh elements. In some embodiments, the mesh elements are regular and evenly spaced within the surface so that the mesh surface may be described as patterned. In other embodiments, the mesh elements may be irregular and not evenly spaced within the surface. For example, a square surface may be divided into a rectangular mesh element and two square mesh elements. Alternatively, a mesh may be designed by starting with a plurality of discrete points and connecting those points to form edges such that the edges eventually form a perimeter of a surface. In some embodiments, a mesh may be connected via a second layer mesh. For example, an outer mesh of circles arranged in a non- planar manner, the mesh elements- i.e. the circles - may be connected via a second layer mesh. As such, additional mesh layers can be constructed by connecting to previous layer.

[0022] A three-dimensional object may comprise a plurality of meshes attached by a plurality of connecting beams. In particular, a first mesh element connected to a second mesh element via a plurality of connecting beams may be called a unit cell. As such, a three- dimensional object may be formed of a plurality of unit cells. For example, a three-dimensional object may include a first, inner mesh comprising a plurality of first, inner mesh elements as well as a second, outer mesh comprising a plurality of second, outer mesh elements. The first, inner mesh and the second, outer mesh may be attached to each other by way of a plurality of connecting beams extending from a plurality of respective inner mesh beam connection points on the inner mesh to a plurality of respective outer mesh beam connection points on the outer mesh. In such embodiments, the first, inner mesh and the second, outer mesh become connected to each other and thereby form a plurality of unit cells. The unit cells of the connected meshes may transfer forces, such as tension, compression, load, twist, stress, and others are known in the art, between the first, inner mesh and the second, outer mesh. In embodiments with more than two meshes, the various forces described above may be further transferred between additional meshes.

[0023] A three-dimensional object's shape may be formed by arranging a plurality of meshes (e.g. inner and outer meshes) concentrically i.e. where the meshes are arranged to share the same center. For example, a spherical, three-dimensional object may comprise a first, spherical, inner mesh concentric with a second, spherical, outer mesh, wherein the meshes are connected via a plurality of connecting beams. Together, the meshes form inner and outer concentric spheres that are interconnected via the plurality of connecting beams. Similarly, a three-dimensional objects shape may be formed by arranging a plurality of meshes in parallel i.e. where the surfaces of the mesh are equidistant from each other. For example, a cubic three- dimensional object may comprise a first, lower mesh parallel with a second, upper mesh, wherein the meshes are connected via a plurality of connecting beams. Notably, the aforementioned arrangements are merely exemplary, and other arrangements are possible. For example, within a single mesh layer, the different mesh elements need not be connected to each other.

[0024] By designing a three-dimensional object with a plurality of connected meshes, it is possible to cause that object to have characteristics that are quite different than those of the material from which the object is composed. For example, a dual-mesh, spherical object may have relatively high rebound resilience despite being made of a material that has a lower resilience. In other words, the object's design creates a rebound resilience notwithstanding the material from which the object is made. By way of example, a spherical object made of a low resilience material may have low rebound resilience while a dual-mesh spherical object made of the same material may have improved rebound resilience characteristics. Alternatively, an object made of a higher resilience material may have a relatively high rebound resilience. However, a dual-mesh object according to embodiments disclosed herein may have an even higher rebound resilience than would otherwise be expected.

[0025] Some of the design variables that may alter the rebound resilience of a three- dimensional object comprising a plurality of meshes include: the size and shape of each mesh component; the relative location of one mesh to another mesh; the size (e.g., thickness, radius, dimensions, etc.) and length of each connecting beam connecting one mesh to another; the angle at which the connecting beams connect one mesh to another; the location of the beam connection points; the number of connecting beams per unit cell of the object; the overall size and weight of the three-dimensional object; the material or materials from which each mesh and each connecting beam is formed; and others.

[0026] In some embodiments, the mesh elements of a first mesh are the same shape as compared to the mesh elements of a second mesh connected to the first mesh by connecting beams. For example, both a first mesh and a second mesh may comprise square mesh elements. In other embodiments, the mesh elements of a first mesh are a different shape as compared to the mesh elements of a second mesh connected to the first mesh by connecting beams. For example, a first mesh may comprise square mesh elements and a second mesh may comprise square circular mesh elements.

[0027] In some embodiments, the connecting beams connect to a vertex of a shape of a mesh element. For example, a connecting beam may connect to the vertex of a square shaped mesh element (i.e. the connection point between two perpendicular segments of the square- shaped mesh element). In other embodiments, the connecting beams may connect to a portion of the segment other than the vertex, such as a center point of a segment between two vertices. In some embodiments, the number of connecting beams connected to a particular mesh element may be spread equally about the perimeter of the mesh element. For example, where four connecting beams are connected to a circle-shaped mesh element, they may be connected one in each quarter or quadrant of the circle (i.e. every 90 degrees of the circle). Similarly, if only three connecting beams are connected to a circle-shaped mesh element, they may be connected one in each third of the circle (i.e. every 120 degrees of the circle).

[0028] In some embodiments, the mesh elements of a first mesh will be larger than the mesh elements in a second mesh connected therewith by a plurality of connecting beams so that the connecting beams will form an angle relative to the surface of either mesh that is not perpendicular (i.e. not 90 degrees). This is possible even when certain dimensions of the mesh elements of the first mesh and those of the second mesh are identical. For example, a circle concentric within a square may have a diameter that equals the length and width of the square such that the circle intersects the square at four positions, but the circle will still have positions along its circumference that are within the boundary of the square and therefore would cause a non-perpendicular angle to be formed if a connecting beam projected from such a position on the circle-shaped mesh element to a position on a segment of the square-shaped mesh element. In addition, in some embodiments, a mesh layer may not be comprised of the same repeating unit cells. Rather, it could be comprised of various different shaped units such as squares and hexagons, for example.

[0029] In some embodiments, a non-perpendicular angle between a connecting beam and the surface of each of two meshes connected therewith is important in order to cause external forces applied to the three-dimensional object to be distributed throughout the meshes rather than causing a connecting beam or mesh element to break. In other words, the non-perpendicular angle may cause forces imparted on the object to be spread down into a unit cell as well as laterally to other unit cells. This is particularly true where the three-dimensional object is made of a material with low resilience characteristics.

[0030] In some embodiments, a connecting beam connected between a first mesh element and a second mesh element will also form a non-perpendicular angle at least with a segment of the first mesh element, and in some embodiments, with a segment of the second mesh element as well, as viewed down the centerline of the two mesh elements (i.e. along the length of the connecting beam). As such, when viewed down the centerline of the two connected mesh elements, one mesh element will appear to be twisted with respect to the other mesh element.

[0031] Figures 1 A- IF depict an embodiment of a method for defining unit cells of a dual- mesh surface. In Figure 1A, a surface 102 is formed. In this embodiment, the surface 102 is rectangular. In Figure IB, the surface 102 is divided into nine square mesh elements 104 to form a mesh surface. Each mesh element includes a plurality of segments 106 and vertices 108. In Figure 1C, a new mesh surface 112 is formed and offset from mesh surface 102. Mesh surface 112 also comprises a plurality of mesh elements 114, which comprise a plurality of segments 116 and vertices 118. In Figure ID, circular mesh elements 120 are formed concentrically within mesh elements 104. In Figure IE, a plurality of beam connection points 130 are determined for mesh elements 114. In this embodiment, the beam connection points 130 are placed at the vertices of the square mesh elements 114. However, in other embodiments, the beam connection points may be placed on a segment of a mesh element that is not a vertex. In Figure IF, connecting beams 140 are formed between the connection points 130 of mesh elements 104 and connection points 145 of circular mesh elements 120. In this embodiment, the connecting beams 140 are connected to the circular mesh elements 120 at equally spaced intervals around the circumference of each circular mesh element 120. However, in other embodiments the connecting beams may be connected at different intervals. Each circular mesh element 120 connected by a plurality of connecting beams 140 to a respective square mesh element 114 forms a unit cell 150.

[0032] Figures 2A-2C depict an embodiment of a method for defining unit cells of a dual-mesh, spherical object. In Figure 2 A, a first, inner mesh 202 is placed concentrically within a second, outer mesh 204. In Figure 2A, both the inner mesh 202 and the outer mesh 204 initially include square-shaped mesh elements. In Figure 2B, circle-shaped mesh element 206 are formed within each square-shaped mesh element of second, outer mesh 204. In Figure 2C, connecting beams 208 are formed between inner beam connection points 210 on the first, inner mesh 202 and outer beam connection points 212 on the second, outer mesh 204.

[0033] Figure 3A depicts an embodiment of a dual-mesh, spherical object 300 made of a material, such as polyamide 12. Although this embodiment provides an example using polyamide 12, it is to be appreciated that other materials having higher or lower resilience may also be used. Further, though a spherical object is depicted, objects of any shape or size may be designed and manufactured according to the techniques and principles discussed herein. The dual-mesh, spherical object 300 includes a first, inner mesh e.g., similar to inner mesh 202, comprising a plurality of inner mesh elements. The dual-mesh, spherical object 300 also includes a second, outer mesh 312 comprising a plurality of second, outer mesh elements 314. The first, mesh elements of the inner mesh are connected to mesh elements of the second, outer mesh 312 via a plurality of connecting beams 310. In this embodiment, the first, inner mesh elements are square-shaped elements while the second, outer mesh elements 314 are ellipse-shaped elements. Further, in this embodiment, the connecting beams 310 form a non-perpendicular angle with each of the surface of the inner mesh and the surface of the outer mesh 304.

[0034] Figure 3B depicts the dual-mesh, spherical object 300 after it has been compressed on opposite ends (in this example, by compressive forces imposed by a thumb and index finger of a person holding the object). Notably, while the material composing the various aspects of the object 300 may be relatively rigid and non- resilient, the three-dimensional object 300, by virtue of its multi-mesh design, has resilient characteristics. For example, dual-mesh, spherical object 300 snaps back into shape after being compressed, even if its shape is compressed significantly. Further, dual-mesh, spherical object 300 has improved resilience as compared to a simple spherical shape made out of the same material. In some embodiments, dual-mesh, spherical object 300 may have a rebound resilience of 70% or greater.

[0035] In the embodiment of Figures 3 A and 3B, the outer mesh elements 312 are ellipse-shaped and mapped to the surface of a sphere i.e. they are not flat. In other words, each ellipse-shaped mesh element 312 is non-planar, i.e. curved in overall shape so that it would lay flat on the surface of a sphere. As such, the outer mesh elements 312 form a more rounded surface of the dual-mesh, spherical object 300.

[0036] In some embodiments, a dual mesh structure may be provided which provides an additional benefit that it resists unit cell deformation and breakage under heavy point loads (i.e., loads concentrated on a specific point) by inducing even pressure distribution inside the design space. Turning now to Figure 4A-4C, an embodiment of such a dual mesh structure 400 is shown. The structure 400 includes an outer mesh having a plurality of load-distributing shields 402. The load-distributing shields 402 may be structured to distribute heavy loads more evenly across the underlying material. The load-distributing shields 402 may have an arbitrary shape. In this example, they are generally squared-shaped.

[0037] The shield 402 may include side surfaces 404 and 406. The side surfaces of neighboring shields are substantially the other's negative image. Without loading, the individual shields to not touch each other. In the example shown in Figures 4A-4C, the side surfaces 404 are generally convex, and the side surfaces 406 have a concave shape which may receive the convex shape of side surface 404 when their respective shields are positioned in close proximity. When positioned in close proximity and not under the application of compressive forces, the side surface may be close to each other, but not touching. When forces are applied to one or more of the shields 402, the shield 402 move downward such that it deforms the connection element 410 (or connection elements) attached to the bottom surface of the shield 402. As discussed previously, the connection element provides a connection between the outer mesh and the inner mesh.

[0038] Because the neighboring shields 402 have side surfaces (404 and 406 respectively) that are each other's negative image, and because they are positioned close together, when sufficient pressure is applied to a shield 402, its downward movement will cause its side surface to meet the side surface of its neighboring shield (or shields). As a result, the applied force will be distributed not only over the shield 402, it also across its neighboring shields and their connection elements to the second layer. By distributing compressive forces over a larger surface area, the dual-mesh object can handle a wide variance in compressive forces being applied to its outer mesh.

[0039] Figure 5 depicts a method of designing and manufacturing a dual-mesh object. In block 502, a first mesh is designed comprising a plurality of first mesh elements. The first mesh elements may comprise a large variety of shapes as described above. The process then moves to block 504. There, a second mesh is formed comprising a plurality of second mesh elements. As with the first mesh, the second mesh elements may comprise a large variety of shapes. In some embodiments the second mesh may be offset from the first mesh by a fixed inter-mesh distance. In some embodiments, the second mesh may be concentric with the first mesh. In some embodiments the mesh may also be enclosed by or enveloped by the second mesh, such as when the first mesh is spherical and within a second spherical mesh. In some embodiments the first and second meshes may be parallel.

[0040] The process may then move to block 506, where beam connection points are identified and/or positioned on the first mesh elements. As described above, the beam connection points may be located, for example at a vertex or along a segment of each mesh element. The process continues at block 508. There, beam connection points are identified and/or positioned on the second mesh elements. As above, the beam connection points may be located at a vertex or along a segment of each mesh element. Once the beam connection points have been defined, the process moves to block 510. There, a plurality of connecting beams are formed between the beam connection points on the first mesh elements and the beam connection points on the second mesh elements. Once the connecting beams have been formed, the dual-mesh object may then bed manufactured at block 512. As noted above, the object may be manufactured from a rigid, low resilience material. In some embodiments, the dual-mesh object may be manufactured by an additive manufacturing technique.

[0041] FIGs. 6A-6G depict an embodiment of a dual-mesh, footwear related object. In particular, FIG. 6A depicts a dual-mesh, insole 600 from a top-side view. FIG. 6B depicts the dual-mesh, insole 600 from another top-side view. FIG. 6C depicts a portion of the dual-mesh, insole 600 from a bottom view. FIG. 6D depicts a portion of the dual-mesh, insole 600 from a side-bottom view. FIG. 6E depicts the dual-mesh, insole 600 from a top view. FIG. 6F depicts a portion of the dual-mesh, insole 600 from a close-up side view. FIG. 6G depicts a portion of a cross section of the dual-mesh, insole 600 from a top-side view.

[0042] The dual-mesh, insole 600 may be made of a suitable material, such as polyamide 12. Although this embodiment provides an example using polyamide 12, it is to be appreciated that other materials having higher or lower resilience may also be used. The dual-mesh, insole 600 includes a first, top (or outer) mesh 602 comprising a plurality of top mesh elements 604. The dual-mesh, insole 600 also includes a second, bottom (or inner) mesh 612 comprising a plurality of second, bottom mesh elements 614. The first, top mesh elements 604 of the top mesh 602 are connected to bottom mesh elements 614 of the second, bottom mesh 612 via a plurality of connecting beams 610. In this embodiment, the first, top mesh elements 604 have rectangular shaped surfaces and trapezoidal shaped surfaces. However, the first top mesh elements 604 may have any suitable shape. In certain aspects, the first top mesh elements 604 may comprise load-distributing shields, such as similar to shields 402. In certain aspects, the first, top mesh 602 is configured to contact the sole of a foot of a user of the insole 600.

[0043] In this embodiment, the second, bottom mesh elements 614 have a cross or X shape. However, the second, bottom mesh elements 614 may have any suitable shape. In certain aspects, the second, bottom mesh 612 is configured to contact the sole or surface of the inside of footwear such as a shoe when the insole 600 is inserted in the footwear.

[0044] Further, in this embodiment, the connecting beams 610 form a non-perpendicular angle with each of the surface of the top mesh 602 and the surface of the bottom mesh 612. It should be noted that the terms "top" and "bottom" are used relatively and for ease of explanation with respect to normal use of an insole.

[0045] Many methods of additive manufacturing are known in the art, such as: Stereolithography (SLA), Selective Laser Sintering (SLS), Selective Laser Melting (SLM) and Fused Deposition Modeling (FDM), among others. Stereolithography (SLA) is an additive manufacturing technique used for "printing" 3D objects one layer at a time. An SLA apparatus may employ, for example, a laser to cure a photo-reactive substance with emitted radiation. In some embodiments, the SLA apparatus directs the laser across a surface of a photo-reactive substance, such as, for example, a curable photopolymer ("resin"), in order to build an object one layer at a time. For each layer, the laser beam traces a cross-section of the object on the surface of the liquid resin, which cures and solidifies the cross-section and joins it to the layer below. After a layer has been completed, the SLA apparatus lowers a manufacturing platform by a distance equal to the thickness of a single layer and then deposits a new surface of uncured resin (or like photo-reactive material) on the previous layer. On this surface, a new pattern is traced thereby forming a new layer. By repeating this process one layer at a time, a complete 3D part may be formed. [0046] Selective laser sintering (SLS) is another additive manufacturing technique used for 3D printing objects. SLS apparatuses often use a high-powered laser (e.g. a carbon dioxide laser) to "sinter" (i.e. fuse) small particles of plastic, metal, ceramic, or glass powders into a 3D object. Similar to SLA, the SLS apparatus may use a laser to scan cross-sections on the surface of a powder bed in accordance with a CAD design. Also similar to SLA, the SLS apparatus may lower a manufacturing platform by one layer of thickness after a layer has been completed and add a new layer of material to form a new layer. In some embodiments, an SLS apparatus may preheat the powder in order to make it easier for the laser to raise the temperature during the sintering process.

[0047] Selective Laser Melting (SLM) is yet another additive manufacturing technique used for 3D printing objects. Like SLS, an SLM apparatus typically uses a high-powered laser to selectively melt thin layers of metal powder to form solid metal objects. While similar, SLM differs from SLS because it typically uses materials with much higher melting points. When constructing objects using SLM, thin layers of metal powder may be distributed using various coating mechanisms. Like SLA and SLS, a manufacturing surface moves up and down to allow layers to be formed individually.

[0048] Fused Deposition Modeling (FDM) is another additive manufacturing technique wherein a 3D object is produced by extruding small beads of, for example, thermoplastic material from an extrusion nozzle to form layers. In a typical arrangement, the extrusion nozzle is heated to melt the raw material as it is extruded. The raw material then hardens immediately after extrusion from a nozzle. The extrusion nozzle can be moved in one or more dimensions by way of appropriate machinery. Similar to the aforementioned additive manufacturing techniques, the extrusion nozzle follows a path controlled by CAD or CAM software. Also similar, the part is built from the bottom up, one layer at a time.

[0049] Objects may be formed by additive manufacturing apparatus using various materials, such as: polypropylene, thermoplastic polyurethane, polyurethane, acrylonitrile butadiene styrene (ABS), polycarbonate (PC), PC-ABS, PLA, polystyrene, lignin, polyamide, polyamide with additives such as glass or metal particles, methyl methacrylate-acrylonitrile- butadiene-styrene copolymer, resorbable materials such as polymer-ceramic composites, and other similar suitable materials. In some embodiments, commercially available materials may be utilized. These materials may include: DSM Somos® series of materials 7100, 8100, 9100, 9420, 10100, 11100, 12110, 14120 and 15100 from DSM Somos; ABSplus-P430, ABSi, ABS-ESD7, ABS-M30, ABS-M30i, PC-ABS, PC-ISO, PC, ULTEM 9085, PPSF and PPSU materials from Stratasys; Accura Plastic, DuraForm, CastForm, Laserform and VisiJet line of materials from 3- Systems; Aluminium, CobaltChrome and Stainless Steel materials; Maranging Steel; Nickel Alloy; Titanium; the PA line of materials, PrimeCast and PrimePart materials and Alumide and CarbonMide from EOS GmbH.

[0050] Objects having improved rebound characteristics as described herein may be manufactured using additive manufacturing techniques. These objects may include items of footwear such as insoles, shoes, sandals, and the like. These objects may also include items such as balls, helmets, saddles, cushions, or other items which benefit from having improved rebound characteristics, especially in cases where they are manufactured from lower resilience materials. Advantageously, an additive manufacturing apparatus may "3D print" a three-dimensional object including multiple meshes in a single, integral work piece. Thus, 3D printing may provide a much higher degree of customization of three-dimensional objects including multiple meshes as compared to traditional manufacturing techniques.

[0051] The present disclosure encompasses all changes, substitutions, variations, alterations, and modifications to the example embodiments described herein that a person having ordinary skill in the art would comprehend. Similarly, where appropriate, the appended claims encompass all changes, substitutions, variations, alterations, and modifications to the example embodiments described herein that a person having ordinary skill in the art would comprehend.

[0052] Although the foregoing embodiments have been described in some detail for purposes of clarity of understanding, the invention is not limited to the details provided. There are many alternative ways of implementing the invention. The disclosed embodiments are illustrative and not restrictive.

Claims

WHAT IS CLAIMED IS;

1. A multiple-mesh object, comprising:

a first mesh comprising a plurality of first mesh elements, each first mesh element comprising a plurality of first mesh element segments;

a second mesh comprising a plurality of second mesh elements, each second mesh element comprising a plurality of second mesh element segments; and

a plurality of connecting beams connecting at least one first mesh element segment of each first mesh element of the plurality of first mesh elements to a respective second mesh element segment of a respective second mesh element of the plurality of second mesh elements.

2. The multiple-mesh object of Claim 1, wherein the first mesh is an outer mesh comprising outer mesh elements, and the second mesh in an inner mesh comprising inner mesh elements.

3. The multiple- mesh object of Claim 2, wherein the outer mesh elements comprise a first shield element and a second shield element, and wherein the first shield element is adjacent to the second shield element.

4. The multiple-mesh object of Claim 3, wherein the first shield element comprises a first side surface, and wherein the second shield element comprises a second side surface, wherein the first side surface is substantially a negative of the second side surface.

5. The multiple-mesh object of Claim 4, wherein the first side surface comprises a convex shape, and wherein the second side surface comprises a concave shape.

6. The multiple- mesh object of Claim 4, wherein the first side surface and the second side surface are arranged such that they do not touch when the first shield and second shield are not subjected to compressive forces.

7. The multiple- mesh object of Claim 6, wherein the first side surface and the second side surface are arranged to touch when subjected to compressive forces, and wherein the compressive forces are distributed across the connecting beams of both the first shield element and the second shield element.

8. The multiple- mesh object of Claim 2, wherein the outer mesh elements comprise a plurality of shield elements, and wherein the plurality of shield elements forms an array of shield elements, and wherein each of the shield elements in the array comprises an outer surface that is substantially the negative of its adjacent shield elements.

9. The multiple-mesh object of Claim 8, wherein the array of shield elements is arranged to cooperatively distribute compressive forces across connecting beams of neighboring shield elements.

10. The multiple-mesh object of Claim 9, wherein the first mesh elements have a first shape, and wherein the second mesh elements have a second, different shape.

11. The multiple- mesh object of Claim 1, wherein a center of the first mesh is offset from a center of the second mesh by a fixed inter-mesh distance.

12. The multiple-mesh object of Claim 1, wherein at least one of the plurality of connecting beams forms a non-perpendicular angle with at least one first mesh element or at least one second mesh element.

13. The multiple-mesh object of Claim 1, wherein the multiple- mesh object comprises a footwear object.

14. The multiple-mesh object of Claim 13, wherein the multiple-mesh object comprises an insole.