TWI896502B - A three-dimensional printed buffer structure for helmets - Google Patents

Abstract

A three-dimensional printed buffer structure for helmets includes a first buffer layer. The first buffer layer includes an outer surface portion, an inner surface portion, and a plurality of supports. The outer surface portion includes a plurality of first rods arranged to intersect and form a grid, with the first rods defining an outer contour near a helmet shell. The inner surface portion includes a plurality of second rods that extend continuously and are spaced apart, remaining adjacent to one another without intersecting, with the second rods defining an inner contour close to a user. The supports are arranged between the outer surface portion and the inner surface portion, with each of the supports having a first end and a second end, in which the first end and the second end of any one of the supports are respectively connected to any one of the first rods and any one of the second rods. The first rods, the second rods, and the supports are integrally formed by three-dimensional printing.

Description

A three-dimensional printed buffer structure for helmets

The present disclosure relates to a three-dimensional printed structure, and more particularly to a three-dimensional printed buffer structure for use in a helmet.

Current helmet designs typically focus on absorbing vertical forces, but they haven't adequately addressed the issue of reducing lateral deflection or rotation caused by lateral forces. In actual use, when a helmet is subjected to lateral forces, inadequate internal cushioning can easily cause lateral deflection or rotation between the helmet and the user's head. This lateral deflection or rotation not only reduces the helmet's stability but can also cause localized stress concentration in certain areas, increasing the risk of injury. Furthermore, the cushioning structure design in existing helmets is relatively limited in its ability to disperse stress, leading to localized stress concentration. Therefore, how to effectively improve the stability of helmets under lateral forces while also taking into account their stress dispersion capabilities is a topic that technical personnel are actively researching.

According to some embodiments of the present disclosure, a three-dimensional printed buffer structure for use in a helmet includes a first buffer layer. The first buffer layer includes an outer surface portion, an inner surface portion, and a plurality of support members. The outer surface portion includes a plurality of first rods, wherein the first rods are arranged in a grid that crosses each other and defines an outer contour close to the outer shell of the helmet. The inner surface portion includes a plurality of second rods, wherein the second rods extend continuously and are spaced apart from each other without intersecting, and define an inner contour close to the user. Support members are disposed between the outer surface portion and the inner surface portion, each support member having a first end and a second end, wherein the first end and the second end of any support member are respectively connected to any first rod and any second rod. The first rod, the second rod and the supporting member are three-dimensionally printed into one body.

In some embodiments of the present disclosure, any supporting member is a straight column member.

In some embodiments of the present disclosure, a first connection angle between any supporting member and the connected first rod is 45 degrees to 135 degrees, and a second connection angle between any supporting member and the connected second rod is 45 degrees to 135 degrees.

In some embodiments of the present disclosure, the first end of any supporting member is connected to an intersection of the grid.

In some embodiments of the present disclosure, any two or more adjacent supporting members intersect with each other.

In some embodiments of the present disclosure, any two or more adjacent supporting members intersect with each other at any first rod or any second rod.

In some embodiments of the present disclosure, the three-dimensional printed buffer structure further includes a second buffer layer connected to the outer surface portion and disposed between the outer surface portion and the outer shell of the helmet, and includes a plurality of lattice structure units, and each lattice structure unit has a hollow area.

In some embodiments of the present disclosure, the first rod, the second rod, the support member, and the lattice structure unit are integrated by three-dimensional printing.

In some embodiments of the present disclosure, each first rod, each second rod, and each supporting member each has a plurality of cellular structures.

In some embodiments of the present disclosure, there are multiple first hollow areas between the first rods, multiple second hollow areas between the second rods, and multiple third hollow areas between the supporting members, and the first hollow areas, the second hollow areas, and the third hollow areas are connected.

According to the above-described embodiments of the present disclosure, by using a non-filled grid design (first rods) to form the outer surface of the first cushioning layer, external forces can be dispersed over a wider area, reducing the damage caused by concentrated stress on a single area and effectively lowering the risk of damage. By using continuously extending, non-intersecting continuous rods (second rods) to form the inner surface of the first cushioning layer, not only can good head fit be provided, but, in conjunction with the design of the support member, the friction of the first cushioning layer on the head in a specific direction can also be enhanced, thereby limiting the relative displacement between the helmet and the head, thereby limiting lateral deflection or rotation of the helmet and enhancing the wearing stability of the helmet. Furthermore, through the deflection of the support member, the horizontal first and second rods can jointly bear the vertically applied load, achieving a stress dispersion effect. Overall, through the synergistic action of the first and second rods and the support member, the present disclosure can improve the overall protective performance and wearing stability of the helmet through a method different from "directly absorbing vertical stress."

The following drawings disclose multiple embodiments of the present disclosure. For the sake of clarity, many practical details will be described together in the following description. However, these practical details should not be used to limit the present disclosure. In addition, for the convenience of the reader, the sizes of the elements in the drawings are not drawn according to the actual scale. In addition, relative terms such as "lower" and "upper" may be used in this article to describe the relationship between one element and another element, as shown in the drawings. It should be understood that relative terms are intended to include different orientations of the device in addition to the orientation shown in the figures. In addition, terms such as "first" and "second" mentioned in the specification or patent application are only used to name different elements or distinguish different embodiments or scopes, and are not used to limit the upper or lower limit on the number of elements, nor are they used to limit the manufacturing order or setting order of the elements.

Please refer to FIG. 1 , which is a perspective view of a three-dimensionally printed cushioning structure 10 applied to a helmet according to some embodiments of the present disclosure, viewed from the bottom opening of the helmet toward the internal structure. It should be understood that the term "helmet" herein generally refers to equipment used to protect the head and can be used in various activities, including but not limited to daily life, sports, work, and military activities. For example, it can be a bicycle helmet, a ski helmet, a roller skating helmet, a climbing helmet, an equestrian helmet, a baseball catcher's helmet, a hockey helmet, a safety helmet (for construction or industrial use), a tactical helmet (for military or tactical use), a fire helmet, or a riot helmet (for police or security use). The disclosed three-dimensional printed buffer structure 10 can be, for example, disposed on the inner side of the hard outer shell of a helmet (i.e., the side of the helmet close to the user's head) to serve as the inner lining of the helmet and can directly contact the user's head.

Figure 2 is a partially enlarged schematic diagram of region R1 of the three-dimensional printed buffer structure 10 in Figure 1. Please refer to Figures 1 and 2 together. The three-dimensional printed buffer structure 10 includes a first buffer layer 100, which includes an outer surface portion O, an inner surface portion I, and a plurality of support members 130. The outer surface portion O is relatively close to the outer shell of the helmet, the inner surface portion I is relatively close to the user's head, and the support members 130 are disposed and connected between the outer surface portion O and the inner surface portion I.

The outer surface O of the first buffer layer 100 includes a plurality of first rods 110. These first rods 110 are arranged in a grid G with a plurality of intersections P, defining the outer contour of the helmet's shell, and thus, the outer contour of the outer surface O of the first buffer layer 100. The geometric features of the grid G disclosed herein are distributed in two dimensions, forming a continuous and complete two-dimensional grid structure. To facilitate understanding of the structure of the grid G, please refer to Figure 3, which is a partially enlarged schematic diagram of region R2 of the 3D-printed buffer structure 10 in Figure 1, after adjusting the viewing angle. As shown in Figure 3, four first rods 110a, 110b, 110c, and 110d together form a grid unit GU. Multiple grid units GU are tightly connected to a common surface (e.g., the surface where the curved surface Q marked in Figure 3 is located) to form a complete two-dimensional grid structure, G. Compared to a completely filled-surface structure (a fully solid structure), the grid G formed by the cross-connected first rods 110 has greater room for deformation when subjected to external forces (impacts). This allows for evenly distributing stress through highly controllable deformation, thereby reducing the damage caused by concentrated stress in a single area. Furthermore, the non-filled structural design of mesh G can also help achieve lightweight structure and provide good breathability, thereby taking into account wearing comfort.

On the other hand, the cross-sectional arrangement of the multiple first rods 110 creates a plurality of hollow areas S1 between them. These hollow areas S1, surrounded by the first rods 110, not only reduce the rigidity of the structure but also provide additional cushioning space, allowing the first rods 110 to flexibly deform in multiple directions when subjected to external forces, thereby enhancing energy absorption and release, and thereby reducing the impact load on the user's head. In some embodiments, the grid G can have a variety of opening shapes (i.e., the shape of the hollow areas S1), such as, but not limited to, triangles, quadrilaterals (e.g., parallelograms, rectangles, trapezoids, rhombuses, trapezoids, etc.), hexagons (e.g., honeycomb shapes), or combinations thereof, to provide protection tailored to different usage scenarios. This embodiment is described using a rectangle as an example.

Please return to Figure 2. The inner surface portion I of the first cushioning layer 100 includes a plurality of second rods 120. These second rods 120 extend continuously and are spaced apart from each other without intersecting. They define an inner contour near the user's head, that is, the contour of the inner surface portion I of the first cushioning layer 100. In some embodiments, the inner surface portion I may directly contact the user's head. By designing the plurality of second rods 120 to be arranged adjacently and extend continuously with no overlap, they not only conform to the shape of the user's head to provide a good fit (compliant fit), but also evenly distribute pressure to reduce localized point pressure, thereby improving wearing comfort. On the other hand, adjacent second rods 120 have a spacer area S2 between them. The spacer area S2 can help improve breathability, allowing air to flow in a specific direction between the rods, thereby improving heat dissipation from the head and reducing the feeling of stuffiness when wearing the rods.

In some embodiments, to accommodate the shape of different parts of the user's head, the second rod 120 may have different arrangements corresponding to different parts of the head, and may extend generally in a single direction within the region corresponding to the same region. The head will be divided into multiple regions and illustrated in Figure 1 . In the embodiment of Figure 1 , the second rod 120 extends generally from the forehead (including the forehead, temples, and sides) to the top of the head in the region corresponding to the front of the head (the upper portion of Figure 1 ). It extends generally from the left and right earlobes to the top of the head in the region corresponding to the middle of the head (the middle portion of Figure 1 ). And it extends generally horizontally from the right (left) side of the head to the left (right) side of the head in the region corresponding to the back of the head (the lower portion of Figure 1 ). This design avoids the potential problems associated with having the second rod 120 extend in the same direction throughout the entire first cushioning layer 100. For example, if the second rod 120 extends from the forehead to the back of the head throughout the entire first cushioning layer 100, then when external force is applied from the forehead or back of the head, the helmet will be easily pushed in the direction of the second rod 120 of the first cushioning layer 100. Without resistance in directions other than the extension direction of the second rod 120, the helmet will be displaced relative to the head, resulting in reduced protective effectiveness.

In contrast, some embodiments of the present disclosure design the second rod 120 to extend in different directions in different areas, creating a multi-directional arrangement of the second rod 120. This allows the helmet to maintain a stable and secure position on the head, effectively dispersing and resisting external forces from all directions, thereby enhancing the overall protective performance of the helmet. Overall, the extension direction of the second rod 120 effectively reduces the possibility of external forces being transmitted along an axis perpendicular to the extension direction. At the same time, the second rod 120 can provide stable friction against external forces perpendicular to the extension direction of the second rod 120 because it extends perpendicular to the external force. This helps reduce or prevent displacement of the first buffer layer 100 in a direction perpendicular to the extension direction of the second rod 120, thereby effectively suppressing slippage or deflection, further enhancing the stability of the structure and the protection effect on the user.

It's worth noting that while the second shaft 120 may have different alignment patterns at different locations, it achieves smooth joints between these locations, allowing the second shaft 120 to appear continuous at the joints. This allows the two sections of the second shaft 120 to be integrated into a seamless, uniformly extended second shaft 120. In other words, after the smooth joint, the two sections of the second shaft 120 can be considered a single, continuously extended second shaft 120. This smooth joint design not only reduces the likelihood of stress concentration at non-seamless joints but also evenly distributes external forces along the continuously extended second shaft 120, further reducing the risk of localized deformation or damage.

Please return to Figure 2. In some embodiments, the second shaft 120 can be appropriately curved or transitioned in different areas based on the specific geometric features of the user's head, while maintaining a certain degree of spacing. Furthermore, the distance D between the second shafts 120 can also be adjusted accordingly based on the geometric features of the user's head. For example, the distance D can be reduced in areas requiring higher support, or increased in areas requiring greater cushioning or avoidance, thereby taking into account the support, cushioning, and fit of the entire structure. The following will be explained using Figures 4A and 4B as examples, where Figure 4A is a partially enlarged schematic diagram of area R3 of the three-dimensional printing buffer structure 10 in Figure 1 after the viewing angle is adjusted, and Figure 4B is a partially enlarged schematic diagram of area R4 of the three-dimensional printing buffer structure 10 in Figure 1 after the viewing angle is adjusted.

FIG4A shows the distribution of the second shafts 120 in the first buffer layer 100, separated by dashed lines, from region R31 corresponding to the forehead to region R32 corresponding to the top of the head. Overall, the plurality of second shafts 120 gradually converge from region R31 corresponding to the forehead to region R32 corresponding to the top of the head (i.e., the distance D between the second shafts 120 gradually decreases). In region R32 corresponding to the top of the head, they curve appropriately based on the shape of the scalp's hair whorls. To achieve more flexible alignment with the curve of the head, some second shafts 120 can further smoothly connect with other second shafts 120 during the curve (or be considered to merge and extend). For example, the second shaft 120a in Figure 4A extends in a generally uniform direction in region R31 corresponding to the forehead. It bends at region R32 corresponding to the crown of the head to smoothly connect with the second shaft 120b, which similarly extends from region R31 to region R32, thereby forming a single, curved second shaft 120. This design allows the second shaft 120 to conform to the natural curve of the hair whorl, providing uniform support and a comfortable fit while avoiding pressure on the whorl area.

It should be understood that while portions of the second shaft 120 may smoothly connect with other second shafts 120 during extension, this is limited to locations where the second shaft 120 needs to accommodate larger directional changes or structural transitions. In other words, smooth connection of the second shaft 120 primarily occurs in areas with specific geometric features that require adaptability (e.g., the area corresponding to the whorl of hair depicted in FIG. 4A ). Overall, most of the second rods 120 in a single area of the first buffer layer 100 still maintain a roughly consistent extension direction, thereby adapting to the head shape corresponding to the area over a large area, and maintaining the structural consistency of the inner surface portion I of the first buffer layer 100, thereby providing uniform support.

Figure 4B shows the distribution of the second rods 120 in the first buffer layer 100, separated by dashed lines, from region R41 corresponding to the back of the head to region R42 corresponding to the sides of the ears. Overall, the multiple second rods 120 extend continuously from region R41 corresponding to the back of the head to region R42 corresponding to the sides of the ears. In region R42 corresponding to the sides of the ears, they are designed to bend to conform to the shape of the ear contour, preventing pressure and stuffiness on the ears. For example, the second rods 120c in Figure 4B extend in roughly the same direction in region R41 corresponding to the back of the head, then bend in a lightning-like pattern in region R42 corresponding to the sides of the ears. Adjacent second rods 120 are roughly equidistant from region R41 to region R42. This lightning-like bend flexes flexibly to the complex curves around the ears, helping to conform to the curvature of the head while effectively avoiding the ear contours, thereby enhancing the overall wearing comfort and stability of the structure. In some embodiments, the second rod 120 may be designed to be bent in a lightning-like manner at the edge of the first buffer layer 100 (e.g., the edge at the back of the head shown at the bottom of FIG. 1 ) to increase friction against the head and thereby improve wearing stability.

Please refer to Figures 2 and 5A simultaneously. Figure 5A is a partially enlarged schematic diagram of region R5 of the 3D-printed buffer structure 10 in Figure 2. The support member 130 connects the outer surface portion O and the inner surface portion I of the first buffer layer 100. Specifically, the support member 130 has a first end 130a and a second end 130b that are opposite to each other, and the first end 130a and the second end 130b are connected to either of the first rods 110 and either of the second rods 120, respectively. Because the support member 130 can firmly connect the first rod 110 and the second rod 120, when an external force is applied to the helmet in a direction non-perpendicular to the top of the head (i.e., sideways), the relative lateral displacement between the first rod 110 and the second rod 120 can be effectively limited. At the same time, combined with the friction between the second rod 120 and the head, the second rod 120 and the support member 130 can jointly pull the first cushioning layer 100 and the helmet back to their original position, thereby reducing lateral deflection or rotation of the helmet caused by lateral forces, effectively reducing relative movement between the helmet and the user's head, improving wearing stability, and enhancing protective effects.

Furthermore, when the first buffer layer 100 is subjected to an external force, the support member 130 may deflect due to the limited relative displacement between the first rod 110 and the second rod 120. This deflection force may redistribute the stress originally concentrated at a single point to a wider area. More specifically, when an external force is applied to the first buffer layer 100 in a direction perpendicular to the force-bearing surface (e.g., the outer surface portion O of the first buffer layer 100), the deflection of the support member 130 can convert this vertical force into a horizontal force. This horizontal force can be further dispersed toward the periphery along the two-dimensional grid structure formed by the first rods 110 and the continuously extending structure formed by the second rods 120 (e.g., along the contours of the outer surface portion O and the inner surface portion I of the first buffer layer 100), thereby reducing the damage caused by local stress concentration to a single point. In addition, the support member 130 also has good deflection recovery performance. It can temporarily store energy inside when subjected to external force, and use its own rebound to quickly release this energy to generate a restoring force after the external force disappears, thereby pulling the second rod 120 back to its original position.

Furthermore, because the force perpendicular to the load-bearing surface is guided and dispersed to the first rod 110 and the second rod 120 by the deflected multiple support members 130, and further transmitted toward the surrounding area along the extension direction of the first rod 110 and the second rod 120, the vertical compression of the first buffer layer 100 during load-bearing is effectively reduced, thereby effectively reducing the deformation of the entire structure. Furthermore, due to the reduced vertical compression, the wear and fatigue accumulation caused by localized compression of the first buffer layer 100 during load-bearing is effectively reduced, thereby enabling the first buffer layer 100 to maintain its long-term stable support and buffering effects.

In some embodiments, the support members 130 primarily utilize the first rods 110 of the grid G configuration as a base for supporting the second rods 120. Consequently, multiple support members 130 are connected to the first rods 110 based on the positions of the second rods 120, forming a spaced arrangement. Specifically, as shown in FIG5A , assuming that the extension direction of a second rod 120 is substantially the same as the arrangement direction of a first rod 110 in the grid G, the support members 130 can be spaced and connected to the first rods 110 at intersection points P or non-intersection points (e.g., rod-shaped sections of the first rods 110).

In some embodiments, support member 130 may be a straight column. In other words, support member 130 has no bends or curves. This straight columnar design allows support member 130 to have a higher degree of support (compression resistance), effectively resisting compression when subjected to stress along the column axis, maintaining structural stability. Furthermore, when subjected to oblique stress (i.e., stress not along the column axis), it can adapt to various angles of deflection and distribute the stress to the surrounding area. In addition, the straight columnar support member 130 is less likely to produce unexpected deformation after being subjected to force, and has a relatively predictable and controllable mechanical response performance, reducing the unstable shaking or displacement of the helmet when subjected to external force, thereby reducing the relative displacement between the helmet and the user's head, and improving wearing safety.

In some embodiments, the connection angle θ between the support member 130 and the first rod 110 and between the support member 130 and the second rod 120 can each be 45 degrees to 135 degrees (e.g., 50 degrees, 55 degrees, 60 degrees, 65 degrees, 70 degrees, 75 degrees, 80 degrees, 85 degrees, 90 degrees, 95 degrees, 100 degrees, 105 degrees, 110 degrees, 115 degrees, 120 degrees, 125 degrees, or 130 degrees). It should be noted that the definition of the connection angle θ herein refers to the connection angle θ between different support members 130 and the first rod 110 and the second rod 120, respectively, in their respective designs. When the connection angle θ falls within the aforementioned range, the support member 130 can provide both support and deflection effects, helping to disperse stress in conjunction with the first rod 110 and the second rod 120. The overall structure exhibits excellent deflection resilience and high lateral rigidity, maintaining structural stability and preventing the connection from being too narrow (less than 45 degrees, e.g., 10 degrees) or too wide (greater than 135 degrees, e.g., 170 degrees), resulting in insufficient support and a consequent inability to provide effective deflection.

In some embodiments, at least some of the first ends 130a of the support members 130 are connected to the intersections P of the grid G. Compared to non-intersections of the grid G (i.e., the rod-shaped sections of the first rods 110), the intersections P have greater structural strength and stability, providing the support members 130 with greater load-bearing capacity, effectively and directly transmitting stress to the entire grid system. Furthermore, connecting the support members 130 at the intersections P strengthens the connection between the support members 130 and the grid G, thereby enhancing the overall structure's resistance to deformation. In actual design, the connection positions of the multiple support members 130 in the first buffer layer 100 and the grid G can be adjusted or matched according to the usage scenario and protection requirements of the helmet, and are not limited to connection at the intersection P or non-intersection points.

The plurality of support members 130 have hollow regions S3 between them, meaning that the support members 130 are spaced apart. In some embodiments, the hollow regions S1 between the first rods 110 and the spaced regions S2 between the second rods 120 can be connected to each other through the hollow regions S3 between the support members 130 (see FIG. 2 ), thereby forming a gas exchange cavity extending continuously from the outer surface O to the inner surface I of the first buffer layer 100. In other words, the hollow regions S1, the spaced regions S2, and the hollow regions S3 are connected to form the gas exchange cavity. This continuous air exchange chamber redistributes air pressure generated by external impact over a larger area, helping to improve cushioning. It also promotes air circulation, preventing heat and moisture from accumulating inside the helmet, thereby reducing stuffiness and keeping your head dry.

In some embodiments, the length L of the support member 130 may be, for example, 3 cm to 10 cm (e.g., 4 cm, 5 cm, 6 cm, 7 cm, 8 cm, 9 cm). This length range helps the support member 130 achieve a balance between its deflection and stress distribution uniformity. Specifically, if the support member 130 is too long, while it may provide a larger deflection amplitude to absorb more energy, it may also cause excessive deformation during the deflection process, resulting in a reduction in the deflection recovery ability of the support member 130. Furthermore, an excessively long support member 130 may also result in an excessively large stress transmission path, making it impossible to effectively and evenly transmit stress to the first rod 110 and the second rod 120, resulting in uneven stress distribution. If the support member 130 is too short, the deflection capacity will be limited, and the stress cannot be fully absorbed and distributed, resulting in localized stress concentration at a single point. In some embodiments, the length L of the support member 130 of the first buffer layer 100 can be designed according to the location of the helmet region. For example, the support members 130 in the same region can be designed to have the same length L. In some embodiments, the support members 130 of the first buffer layer 100 of the entire helmet are designed to have the same length L.

Please refer to FIG. 5B , which illustrates the structure of support members 130 according to other embodiments of the present disclosure. The area shown corresponds to region R5 of the 3D printing buffer structure 10 in FIG. 2 . In the embodiment of FIG. 5B , adjacent support members 130 intersect at the second rod 120 . In other embodiments (not shown), adjacent support members 130 may also intersect at the first rod 110 . When the support member 130 intersects the first rod 110 or the second rod 120 at one point, that point becomes a dispersion center for multi-directional forces, which can more evenly distribute external forces to all rod-like structures connected thereto (e.g., the first rod 110, the second rod 120, and the support member 130), helping to reduce the occurrence of local stress concentration. In some other embodiments (not shown), adjacent support members 130 may intersect to form a cross structure in the space between the first rod 110 and the second rod 120. In addition to the connection points between the support members 130 and the first rod 110 and the second rod 120, the cross structure increases the stress distribution path by adding an intersection point. The cross structure also provides additional structural support, thereby enhancing the first buffer layer 100's ability to resist deformation in all directions.

Please return to Figure 2. In some embodiments, the entire first buffer layer 100 can be 3D-printed as a single piece. That is, the first rod 110, the second rod 120, and the support member 130 in the first buffer layer 100 are integrally molded. This seamless integration and material consistency avoid potential joint weaknesses and material interface weaknesses, thereby improving overall stress transfer efficiency. This allows stress acting on the helmet to be more evenly distributed throughout the first buffer layer 100, reducing localized stress concentrations.

In some embodiments, the entire first cushioning layer 100 may be foamed after being 3D printed. In other words, each first rod 110, each second rod 120, and each support member 130 in the first cushioning layer 100 may each have multiple cellular structures. See FIG6 , which is a schematic cross-sectional microscopic view of the first rod 110, second rod 120, or support member 130 according to some embodiments of the present disclosure, showing the cellular structure H. The cellular structure H provides additional space to accommodate compressive deformation, effectively distributing and reducing external force impact, and providing additional cushioning and support effects. Furthermore, the cellular structure H can reduce the amount of material used in the first cushioning layer 100 while maintaining sufficient strength, thereby achieving a balance between lightweighting and increased strength. Furthermore, the cellular structure H can enhance breathability, thereby improving wearing comfort. In some embodiments, the cellular structure H can have a micron scale, that is, the pore diameter of a single cellular structure H can be 10 microns to 800 microns (e.g., 100 microns, 200 microns, 300 microns, 400 microns, 500 microns, 600 microns, 700 microns). Compared to nanoscale cellular structures H, micron-scale cellular structures H are less prone to collapse or deformation, thereby providing a more durable cushioning and support effect. Furthermore, micron-scale cellular structures H can provide relatively high breathability, thereby providing a better wearing experience.

In some embodiments, the first rod 110, the second rod 120, and the support member 130 in the first cushioning layer 100 are made of the same material. In some embodiments, the first rod 110, the second rod 120, and the support member 130 can be made of an elastic material, including but not limited to thermoplastic polyurethane, polyurethane-based materials, expanded polystyrene, and foam. This provides the first cushioning layer 100 with flexibility and pliability, allowing it to flexibly conform to the natural curves of the head and avoid pressure or discomfort caused by rigid structures.

Please continue with Figure 2. In some embodiments, the 3D-printed buffer structure 10 may further include a second buffer layer 200 disposed between the outer surface O of the first buffer layer 100 and the outer shell of the helmet. When the helmet is subjected to an external force, the external force may sequentially pass through the second buffer layer 200 and the first buffer layer 100 to reach the user's head. In some embodiments, the second buffer layer 200 may include a plurality of lattice structure units 210 arranged continuously in three-dimensional space. In some embodiments, the lattice structure unit 210 may be an expansion or three-dimensional extension of the two-dimensional structure grid G in three-dimensional space. For example, the lattice structure unit 210 may be a cubic lattice structure expanded and extended in three-dimensional space by the quadrilateral structure grid G shown in Figure 2, and may be further designed into multiple layers based on the overall buffering capability requirements. In the embodiment of Figure 2, the second buffer layer 200 is three-layered. In other embodiments, the lattice structure of the lattice structure unit 210 may also be replaced by a lattice structure as shown in Figures 7A to 7H, such as the body-centered cubic lattice in Figure 7A, the face-centered cubic lattice in Figure 7B, the fluorite lattice in Figure 7C, the Kelvin lattice in Figure 7D, the gyroid lattice in Figure 7E, the Schwarz lattice in Figure 7F, the diamond lattice in Figure 7G, and the split-P lattice in Figure 7H. In general, the second buffer layer 200 achieves the effect of directly absorbing the stress applied perpendicular to the stress-bearing surface through its non-filled structural design composed of a plurality of lattice structure units 210.

In some embodiments, the hollow region S4 in the lattice structure unit 210 may also be connected to the hollow region S1 between the first rods 110, the spacing region S2 between the second rods 120, and the hollow region S3 between the support members 130 to form a gas exchange chamber that extends continuously from the inner surface portion I of the first buffer layer 100 to the outer surface portion U of the second buffer layer 200.

In some embodiments, the first buffer layer 100 and the second buffer layer 200 can be integrally formed by three-dimensional printing. That is, the first rods 110, the second rods 120, and the supporting members 130 in the first buffer layer 100 are integrally formed with the lattice structure units 210 in the second buffer layer 200. In other embodiments, the second buffer layer 200 can be combined with the first buffer layer 100 through suitable means such as gluing, mechanical connection (e.g., mortise and tenon joints or snap fasteners), welding (e.g., heat fusion welding, ultrasonic welding), or additional mounting fixtures to provide flexibility in design and assembly.

In some embodiments, the entire second buffer layer 200 may be foamed after being three-dimensionally printed. In other words, each lattice structure unit 210 in the second buffer layer 200 may have multiple pore structures H in the first buffer layer 100 as shown in FIG. 6 .

It is worth noting that the design of the first buffer layer 100 in this disclosure focuses on the function of "reducing lateral deflection or rotation of the helmet" provided by the support member 130. Specifically, the support member 130 limits the relative displacement between the first rod 110 and the second rod 120, and the friction between the second rod 120 and the head is used to resist lateral deflection or rotation of the first buffer layer 100 caused by lateral forces. Furthermore, the support member 130 also functions to redistribute stress. Specifically, the deflection of the support member 130 converts stress applied vertically to the load-bearing surface into horizontal forces. These horizontal forces are then further distributed and transmitted to the surrounding area through the two-dimensional grid structure of the first rod 110 and the continuously extended structure of the second rod 120. This allows multiple horizontal rod-like structures (e.g., the first rod 110 and the second rod 120) to collaboratively bear the vertically applied load, thereby reducing the damage caused by localized stress concentration at a single point. In some embodiments, the additional second buffer layer 200 can further provide the function of "absorbing vertical stress." Specifically, through the geometric characteristics of the lattice structure unit 210 (for example, the three-dimensional distribution of the lattice structure and the cavity design) and the elasticity of the material, it directly absorbs the stress applied perpendicular to the load-bearing surface, reducing the energy transferred from the stress to the inner layers. In other words, the first buffer layer 100 and the second buffer layer 200 achieve the buffering effect through different means. Overall, the first cushioning layer 100 itself can achieve good protective performance through its ability to "limit lateral deflection or rotation of the helmet" and "redistribute stress." By further combining the first cushioning layer 100 with the second cushioning layer 200, the cushioning and protective effects can be further enhanced by "absorbing vertical stress," thereby enhancing the overall protective performance of the helmet and providing more comprehensive safety protection.

According to the above-described embodiments of the present disclosure, by using a non-filled grid design (first rods) to form the outer surface of the first cushioning layer, external forces can be dispersed over a wider area, reducing the damage caused by concentrated stress on a single area and effectively lowering the risk of damage. By using continuously extending, non-intersecting continuous rods (second rods) to form the inner surface of the first cushioning layer, not only can good head fit be provided, but, in conjunction with the design of the support member, the friction of the first cushioning layer on the head in a specific direction can also be enhanced, thereby limiting the relative displacement between the helmet and the head, thereby limiting lateral deflection or rotation of the helmet and enhancing the wearing stability of the helmet. Furthermore, through the deflection of the support member, the horizontal first and second rods can jointly bear the vertically applied load, achieving a stress dispersion effect. Overall, through the synergistic action of the first and second rods and the support member, the present disclosure can improve the overall protective performance and wearing stability of the helmet through a method different from "directly absorbing vertical stress."

Although the present disclosure has been disclosed in the form of embodiments as described above, it is not intended to limit the present disclosure. Anyone skilled in the art may make various changes and modifications without departing from the spirit and scope of the present disclosure. Therefore, the scope of protection of the present disclosure shall be determined by the scope of the attached patent application.

10: 3D-printed buffer structure 100: First buffer layer 110, 110a, 110b, 110c, 110d: First rod 120, 120a, 120b, 120c: Second rod 130: Support member 130a: First end 130b: Second end 200: Second buffer layer 210: Lattice structure unit Q: Curved surface H: Cell structure θ: Connection angle L: Length D: Pitch P: Intersection G: Grid GU: Grid unit O, U: Outer surface I: Inner surface S1, S3, S4: Hollow area S2: Spacing area R1, R2, R3, R31, R32, R4, R41, R42, R5: Area

To facilitate understanding of the above and other objects, features, advantages, and embodiments of the present disclosure, the accompanying drawings are described as follows: Figure 1 is a schematic three-dimensional illustration of a three-dimensionally printed buffer structure for use in a helmet according to some embodiments of the present disclosure; Figure 2 is a schematic enlarged partial view of region R1 of the three-dimensionally printed buffer structure of Figure 1; Figure 3 is a schematic enlarged partial view of region R2 of the three-dimensionally printed buffer structure of Figure 1 after adjusting the viewing angle; Figure 4A is a schematic enlarged partial view of region R3 of the three-dimensionally printed buffer structure of Figure 1 after adjusting the viewing angle; Figure 4B is a schematic enlarged partial view of region R4 of the three-dimensionally printed buffer structure of Figure 1 after adjusting the viewing angle; Figure 5A is a partially enlarged schematic diagram of region R5 of the 3D printing buffer structure in Figure 2. Figure 5B illustrates the structure of a support member according to other embodiments of the present disclosure, with the region corresponding to region R5 of the 3D printing buffer structure in Figure 2. Figure 6 is a cross-sectional microscopic schematic diagram of a first rod, a second rod, or a support member according to some embodiments of the present disclosure. Figures 7A to 7H are schematic diagrams of the lattice structure of a lattice structure unit according to various embodiments of the present disclosure.

100: First buffer layer

110: First shot

120: Second shot

130: Support

200: Second buffer layer

210: Lattice structure unit

D: Spacing

P: Intersection point

G: Grid

O, U: Outer surface

I: Inner surface

S1, S3, S4: hollowed-out areas

S2: Interval area

R1, R5: Area

Claims (10)

A three-dimensionally printed cushioning structure for use in a helmet comprises: A first cushioning layer comprising: An outer surface portion comprising a plurality of first rods, wherein the first rods are arranged in a grid-like arrangement and define an outer contour adjacent to an outer shell of the helmet; An inner surface portion comprising a plurality of second rods, wherein the second rods extend continuously and are spaced apart from each other without intersecting, and define an inner contour adjacent to a user; and A plurality of support members disposed between the outer surface portion and the inner surface portion, each of the support members having a first end and a second end, wherein the first end and the second end of any one of the support members are connected to any one of the first rods and any one of the second rods, respectively; The first rods, the second rods, and the supporting parts are three-dimensionally printed into one piece. A three-dimensional printing buffer structure as described in claim 1, wherein any one of the supporting members is a straight column member. A three-dimensional printing buffer structure as described in claim 2, wherein a first connection angle between any one of the support members and the one of the first rods to which they are connected is 45 degrees to 135 degrees, and a second connection angle between any one of the support members and the one of the second rods to which they are connected is 45 degrees to 135 degrees. The three-dimensional printing buffer structure as described in claim 1, wherein the first end of any one of the support members is connected to an intersection of the grid. The three-dimensional printing buffer structure as described in claim 1, wherein any two or more adjacent supporting members intersect with each other. The three-dimensional printing buffer structure as described in claim 5, wherein any two or more of the adjacent supporting members intersect at any one of the first rods or any one of the second rods. The three-dimensionally printed buffer structure of claim 1 further comprises: A second buffer layer connected to the outer surface portion and disposed between the outer surface portion and the outer shell of the helmet, comprising a plurality of lattice structure units, each of the lattice structure units having a hollow region. The three-dimensionally printed buffer structure as described in claim 7, wherein the first rods, the second rods, the supporting members and the lattice structure units are three-dimensionally printed into one body. The three-dimensional printing buffer structure as described in claim 1, wherein each of the first rods, each of the second rods, and each of the supporting members each has a plurality of bubble structures. A three-dimensional printing buffer structure as described in claim 1, wherein there are multiple first hollow areas between the first rods, multiple second hollow areas between the second rods, multiple third hollow areas between the supporting members, and the first hollow areas, the second hollow areas and the third hollow areas are connected.