Mounting arrangement for self-supporting spoke structure of non-pneumatic tire

Abstract

A non-pneumatic tire includes a lower ring having a first diameter and an upper ring having a second diameter. The upper ring is substantially coaxial with the lower ring. A support structure connects the lower ring to the upper ring. The supporting structure is composed of a plurality of spokes. The support structure is arranged and configured such that adjacent spokes of the plurality of spokes contact each other upon occurrence of a high impact event.

Description

Technical Field

[0001] The present disclosure relates to a non-pneumatic tire. More particularly, the present disclosure relates to a non-pneumatic tire having a support structure with spokes designed to contact each other during a high-impact event. Background Art

[0002] Various tire constructions have been developed that enable the tire to be driven in an uninflated or underinflated state. Non-pneumatic tires do not require inflation, while "run-flat tires" can continue to be driven at relatively high speeds for extended periods of time after being punctured and partially or completely depressurized. Non-pneumatic tires may include support structure, such as spokes or webs, connecting a lower ring to an upper ring. In some non-pneumatic tires, a circumferential tread may be attached to the upper ring of the tire.

[0003] The circumferential tread may include a tread band. The tread band may be a single layer of material or a multi-layered band. This tread band may also be referred to as a shear band, shear element, or thin, annular, high-strength band element. When used in a non-pneumatic tire or in a partially or unpressurized pneumatic tire, the shear element acts as a structural compression member. When used in a fully pressurized pneumatic tire, the shear element acts as a tension member.

[0004] Tire design for both pneumatic and non-pneumatic tires involves a balance of many factors, including but not limited to load capacity, handling, and ride quality. Regardless of the balance chosen between these factors, non-pneumatic tires must be durable and able to withstand high-impact events, such as hitting curbs, potholes, or other obstacles or road imperfections. Summary of the Invention

[0005] In one embodiment, a non-pneumatic tire includes a lower ring having a plurality of scalloped recesses. Each of the plurality of scalloped recesses has a first curved surface. An upper ring is substantially coaxial with the lower ring. A support structure connects the lower ring to the upper ring. The support structure is comprised of a plurality of spokes. The plurality of spokes are arranged into a first spoke group and a second spoke group axially spaced apart from the first spoke group. Each of the plurality of spokes includes a first end connected to the lower ring and a second end connected to the upper ring. Each of the plurality of spokes also includes a first surface and a second surface facing oppositely from the first surface. Each of the first and second surfaces extends between the first and second ends. A foot is provided toward the first end of the spoke. The first surface of the spoke at the foot is a second curved surface. The second curved surface is attached to the first curved surface of one of the plurality of scalloped recesses to connect the first end of the spoke to the lower ring.

[0006] In another embodiment, a method for manufacturing a non-pneumatic tire includes providing a lower ring having a first diameter and an upper ring having a second diameter greater than the first diameter. A plurality of scalloped recesses are formed on the lower ring. Each of the plurality of scalloped recesses has a first curved surface. A plurality of spokes are formed, each having a first surface and a second surface facing opposite the first surface. The first surface and the second surface each extend between a first end and a second end. Forming the plurality of spokes includes providing a foot toward the first end of the spoke. The first surface of the spoke at the foot is a second curved surface. The lower ring is connected to the upper ring via a first group of spokes and a second group of spokes. Connecting the lower ring to the upper ring includes attaching the second curved surface of the spoke at the foot to the first curved surface of one of the plurality of scalloped recesses to connect the first end of the spoke to the lower ring and the second end of the spoke to the upper ring.

[0007] In another embodiment, a non-pneumatic tire includes a lower ring having a first radius of curvature. The lower ring is provided with a plurality of scalloped notches. Each scalloped notch includes a first curved surface having a second radius of curvature. An upper ring is substantially coaxial with the lower ring. A support structure connects the lower ring to the upper ring. The support structure is comprised of a plurality of spokes. Each spoke extends between a first end and a second end and includes a first surface and a second surface facing opposite the first surface. Each of the first surface and the second surface extends between the first end and the second end. The spoke is provided with a foot toward the first end. The first surface of the spoke at the foot is a second curved surface having a third radius of curvature. Each of the first radius of curvature and the second radius of curvature is different from the third radius of curvature. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] In the accompanying drawings, structures are shown which, together with the detailed description provided below, describe exemplary embodiments of the invention as claimed. Similar elements are designated by the same reference numerals. It should be understood that elements shown as a single component may be replaced with multiple components, and elements shown as multiple components may be replaced with a single component. The drawings are not drawn to scale, and the proportions of certain elements may be exaggerated for illustrative purposes.

[0009] Figure 1 is a side view of one embodiment of a non-pneumatic tire,

[0010] Figure 2 yes Figure 1 Another side view of a non-pneumatic tire,

[0011] Figure 3 yes Figure 1 The cross-sectional view along 3-3,

[0012] Figure 4 yes Figure 1 Detailed view of area A,

[0013] Figure 5 yes Figure 1 Detail of area A with some features removed for clarity,

[0014] Figure 6 yes Figure 1 Detail of a single spoke used in a non-pneumatic tire.

[0015] Figure 7 When the tire is on a flat surface and carrying a normal load Figure 1 a side view of a portion of a non-pneumatic tire,

[0016] Figure 8 When the tire is on a flat surface and carrying a normal load Figure 1 A side view of a portion of a non-pneumatic tire with some features removed for clarity.

[0017] Figure 9 When the tire is on an uneven surface Figure 1 a side view of a portion of a non-pneumatic tire,

[0018] Figure 10 When the tire is on an uneven surface Figure 1 A side view of a portion of a non-pneumatic tire with some features removed for clarity.

[0019] Figure 11 It shows the manufacturing Figure 1 Flowchart of the method for a non-pneumatic tire,

[0020] Figure 12 is another embodiment of a spoke for a non-pneumatic tire,

[0021] Figure 12a yes Figure 12 End view of the spoke along II,

[0022] Figure 13 is a side view of a non-pneumatic tire illustrating the effects of manufacturing tolerances in the spokes before the second ends of the spokes are attached to the upper ring,

[0023] Figure 14 After the second end of the spoke is attached to the upper ring Figure 13 side view of a non-pneumatic tire,

[0024] Figure 15 is a partial view of another embodiment of a non-pneumatic tire,

[0025] Figure 16 yes Figure 15 Detail of a single spoke used in a non-pneumatic tire.

[0026] Figure 17 is a partial side view of another embodiment of a non-pneumatic tire,

[0027] Figure 18 yes Figure 17 A partial perspective view of a non-pneumatic tire,

[0028] Figure 19 yes Figure 17 Another partial perspective view of a non-pneumatic tire,

[0029] Figure 20 is a partial side view of yet another embodiment of a non-pneumatic tire, and

[0030] Figure 21 yes Figure 20 Detail of a single spoke of a non-pneumatic tire. DETAILED DESCRIPTION

[0031] The following includes definitions of selected terms used herein. These definitions include various examples or forms of components that fall within the scope of the term and can be used for implementation. The examples are not intended to be limiting. Both singular and plural forms of the terms may be included within the definitions.

[0032] "Axial" and "axially" refer to directions parallel to the tire's axis of rotation.

[0033] “Circumferential” and “circumferentially” refer to directions perpendicular to the axial direction extending along the circumference of the surface of the tread.

[0034] "Radial" and "radially" refer to directions perpendicular to the tire's axis of rotation.

[0035] As used herein, "tread" means that portion of the tire that comes into contact with the road or ground under normally inflated and normally loaded conditions.

[0036] Although similar terms are used in the following description to describe common tire components, it should be understood that because these terms carry slightly different meanings, one of ordinary skill in the art would not consider any of the following terms to be completely interchangeable with another term used to describe common tire components.

[0037] Directions are described herein with reference to the tire's axis of rotation. The terms "upward" and "upwardly" refer to a general direction toward the tire's tread, while "downward" and "downwardly" refer to a general direction toward the tire's axis of rotation. Thus, when relative directional terms such as "upper" and "lower" or "top" and "bottom" are used in conjunction with an element, the "upper" or "top" element is spatially closer to the tread than the "lower" or "bottom" element. Furthermore, when relative directional terms such as "above" or "below" are used in conjunction with an element, if an element is "above" another element, it means that the element is closer to the tread than the other element.

[0038] The terms "inwardly" and "inwardly" refer to general directions toward the equatorial plane of the tire, while "outwardly" and "outwardly" refer to general directions away from the equatorial plane of the tire and toward the sides of the tire. Thus, when relative directional terms such as "inner" and "outer" are used in connection with an element, the "inner" element is spatially closer to the equatorial plane of the tire than the "outer" element.

[0039] Figures 1 to 5 One embodiment of a non-pneumatic tire 10 is shown. The non-pneumatic tire 10 is shown for exemplary purposes only and is not intended to be limiting. In the illustrated embodiment, the non-pneumatic tire 10 includes a generally annular lower ring 20. The lower ring 20 can engage a vehicle wheel hub (not shown) to attach the tire 10 to the vehicle. The lower ring 20 has an inner surface 23 and an outer surface 24 and can be made of a polymeric material, an elastomeric material, a metal, a composite composed of a polymer reinforced with glass or carbon fiber, or any other desired material or combination of materials.

[0040] The non-pneumatic tire 10 also includes a generally annular upper ring 30. Upper ring 30 has a diameter greater than that of lower ring 20 and is substantially coaxial with lower ring 20. Upper ring 30 has an inner surface 33 and an outer surface 34 and may be made of a polymeric material, an elastomeric material, a metal, a composite composed of a polymer reinforced with glass or carbon fiber, or any other desired material or combination of materials. A circumferential tread 70 is attached to outer surface 34 of upper ring 30. Circumferential tread 70 may be attached to upper ring 30 adhesively, mechanically, or by any other desired arrangement.

[0041] like Figure 3 As shown, circumferential tread 70 includes a tread band 72 and a tread layer 74. Tread band 72 and tread layer 74 may be made of the same material or different materials. Tread layer 74 may be made of rubber and may include tread elements (not shown) such as grooves, ribs, blocks, lugs, sipes, posts, or any other desired tread elements. The tread band may include a filament assembly.

[0042] In the illustrated embodiment, the tread band 72 is shown as a single layer. In an alternative embodiment, the tread band may be a multi-layer band. Such a multi-layer tread band may include one or more layers of substantially inextensible material. The layers may be formed from sheets of material, strands of material, filaments of material, or any other desired arrangement. In other alternative embodiments, the multi-layer tread band may include a layer of extensible material, such as an elastomer. According to one exemplary embodiment, the tread band may include a pair of inextensible layers separated by a layer of extensible material. In yet other alternative embodiments, the tread band may include a band known as a shear band, a shear element, or a thin, annular, high-strength belt element.

[0043] The support structure 100 connects the lower ring 20 to the upper ring 30. The support structure 100 extends from the outer surface 24 of the lower ring 20 and the inner surface 33 of the upper ring 30. The support structure 100 is formed from a plurality of spokes 200. In the illustrated embodiment, the plurality of spokes 200 are arranged into two axially spaced sets of spokes, including a first set of spokes 202 and a second set of spokes 204 axially spaced from the first set of spokes 202. In alternative embodiments, the support structure may include more than two axially spaced sets of spokes.

[0044] like Figure 3 As shown, the first spoke set 202 and the second spoke set 204 are spaced apart from each other in the axial direction. In alternative embodiments, the space between the first spoke set and the second spoke set can be larger or smaller, or the first spoke set and the second spoke set can be arranged with no space between them. Figure 1 Each spoke 200 of the first spoke set 202 is substantially convex relative to the clockwise circumferential direction of the non-pneumatic tire 10 , and each spoke of the second spoke set 204 is substantially concave relative to the clockwise circumferential direction of the non-pneumatic tire 10 , when viewed at the angle shown.

[0045] All spokes 200 of the first spoke group 202 and the second spoke group 204 have the same construction. Therefore, the description of the spokes 200 will refer to Figure 6 The spokes 200 are made of a single spoke 200 shown in FIG. The spokes 200 may be made of a metal such as steel or aluminum, a polymer such as polyester or nylon, a composite such as a glass fiber or carbon fiber reinforced polymer, or any other desired material or material combination. The spokes 200 may be provided with reinforcements (not shown).

[0046] The spoke 200 extends between a first end 206 and a second end 208 and has a generally rectangular cross-section including a first surface 210 and a second surface 212 facing opposite the first surface 210. The spoke thickness t refers to the distance between the first surface 210 and the second surface 212. In the illustrated embodiment, the spoke 200 has a constant thickness between the first end 206 and the second end 208. In alternative embodiments, the thickness of the spoke may vary between the first and second ends. For example, the spoke may have relatively thicker portions at the first and second ends and a relatively thinner portion between the ends. In other alternative embodiments, the spoke may have any desired cross-sectional shape (e.g., circular, diamond-shaped, hexagonal, etc.) or may have a combination of different cross-sectional shapes.

[0047] An integral foot 214 is provided toward the first end 206 of the spoke 200. At the foot 214, the first surface 210 of the spoke 200 is attached to the outer surface 24 of the lower ring 20 to connect the first end 206 of the spoke 200 to the lower ring 20. The foot 214 can be attached to the outer surface 24 of the lower ring 20 using welding, brazing, soldering, adhesives, mechanical fasteners (e.g., bolts, rivets), a key / keyway, or any other desired arrangement. In the illustrated embodiment, the foot 214 is substantially straight and is secured to the outer surface 24 of the lower ring 20 over its entire length (the dimension of the foot extending in the circumferential direction of the tire) and its entire width (the dimension of the foot extending in the axial direction of the tire). In alternative embodiments, the foot can be a separate component attached to the spoke. In other alternative embodiments, the foot can be curved to match the radius of curvature of the outer surface of the lower ring or have any other desired curvature. In yet other alternative embodiments, only a portion or multiple discrete portions of the foot can be attached to the outer surface of the lower ring. In other alternative embodiments, the feet may be attached below the outer surface of the lower ring, or the spokes may extend through the lower ring so that the feet may be attached to the inner surface of the lower ring.

[0048] The flexure members 216 are disposed at the second ends 208 of the spokes 200. The flexure members 216 have a width extending in the axial direction of the tire. The flexure members 216 may be made of a polymer (e.g., polyurethane or rubber), a thin, curved piece of metal, or any other desired material or combination of materials. In the illustrated embodiment, the flexure members 216 are configured as rectangular parallelepipeds and are arranged so that the ends of the flexure members 216 are aligned with the second ends 208 of the spokes 200. In other alternative embodiments, the flexure members may be arranged so that the ends of the flexure members are retracted relative to the second ends of the spokes, or may be arranged so that the ends of the flexure members extend beyond the second ends of the spokes. In yet other alternative embodiments, the flexure members may be replaced with mechanical pin joints (i.e., hinges).

[0049] The flexure member 216 includes a spoke-facing surface 218 and a ring-facing surface 220. The spoke-facing surface 218 of the flexure member 216 is attached to the second surface 212 of the spoke 200, and the ring-facing surface 220 is attached to the inner surface 33 of the upper ring 30 to connect the second end 208 of the spoke 200 to the upper ring 30. The attachment between the flexure member 216 and the spoke 200 or between the flexure member 216 and the upper ring 30 can be achieved using welding, brazing, soldering, adhesives, mechanical fasteners (e.g., bolts, rivets), keys / keyways, or any other desired arrangement. For example, the attachment can be provided by pouring polyurethane directly onto the spokes, with or without first applying a primer to the spokes.

[0050] The flex members 216 provide flexibility to the connection between the second ends 208 of the spokes 200 and the upper ring 30. This flexibility reduces the likelihood of high stresses developing within the spokes 200, thereby increasing the robustness of the non-pneumatic tire 10. The connection provided by the feet 214 at the first ends 206 of the spokes 200 is more rigid than the flexible connection provided by the flex members 216.

[0051] In alternative embodiments, the flexure members may have shapes or configurations that differ from those specifically shown and described. In other alternative embodiments, additional structures or mechanisms may supplement the flexure members to attach the second ends of the spokes to the upper ring. In yet other alternative embodiments, the flexure members may be omitted, and the second ends of the spokes may be attached directly to the upper ring. In these alternative embodiments, the second ends of the spokes may be attached directly to, above, the inner surface of the upper ring, or the spokes may extend through the upper ring so that the second ends may be attached to the outer surface of the upper ring.

[0052] The spoke 200 includes a toggle portion 222 located between the first end 206 and the second end 208. The toggle portion 222 has a first radius of curvature r1. According to one exemplary embodiment, the first radius of curvature r1 is 2 inches to 6 inches (5 cm to 15 cm). When attached to the upper ring 20 and the lower ring 30, the toggle portion 222 is concavely curved relative to the lower ring 20.

[0053] The transition portion 224 is disposed between the toggle portion 222 and the first end 206. The transition portion 224 has a second radius of curvature r2. According to one exemplary embodiment, the second radius of curvature r2 is between 0 inches and 2 inches (0 cm and 5 cm). When attached to the upper ring 20 and the lower ring 30, the transition portion 224 is convexly curved relative to the lower ring 20. Thus, the toggle portion 222 and the transition portion 224 are concavely curved in opposite facing directions relative to the single spoke 200. In alternative embodiments, the toggle portion and the transition portion are concavely (or convexly) curved in the same direction.

[0054] The foot 214 extends from the transition portion 224 to the first end 206 of the spoke 200. A first connecting portion 226 connects the transition portion 224 to the toggle portion 222, and a second connecting portion 228 connects the toggle portion 222 to the second end 208 of the spoke 200. In the illustrated embodiment, both the first connecting portion 226 and the second connecting portion 228 are linear. In alternative embodiments, the first connecting portion or the second connecting portion can be curved or have any other desired configuration. In other alternative embodiments, the transition portion and foot can be omitted. In such alternative embodiments, the first end of the spoke would be located at the end of the first connecting portion.

[0055] Base plane p1 intersects the transition portion 224 and the second end 208 of the spoke 200 and serves as a reference for various dimensional aspects of the spoke 200. The angle α between base plane p1 and a second plane p2 extending tangentially to the outer surface 24 of the lower ring 20 at the transition portion 224 is α. According to one exemplary embodiment, angle α is between +0 degrees and 20 degrees. The distance d1 between the transition portion 224 and the second end 208 of the spoke 200, along a direction parallel to base plane p1, is d1. According to one exemplary embodiment, distance d1 is between 10 inches and 25 inches (25 cm and 63.5 cm). The distance d2 between the center of the transition portion 224 and the center of the first radius of curvature r1 of the toggle portion 222, along a direction parallel to base plane p1, is d2. According to one exemplary embodiment, the value of distance d2 is between 20% and 70% of distance d1. The maximum distance d3 between the toggle portion 222 and base plane p1, along a direction perpendicular to base plane p1, is d3. According to one example embodiment, distance d3 is 2 inches to 4 inches (5 cm to 10 cm).

[0056] Reference Figure 10 The transition portion 224 of one spoke 200 is separated from the first end 206 of the adjacent spoke 200 by a first spacing distance s1. The second ends 208 of the adjacent spokes 200 are separated from each other by a second spacing distance s2 (see also Figure 5 ).

[0057] A non-pneumatic tire constructed according to the above-described design parameters may provide a more robust assembly, particularly in terms of impact performance. Figure 7 and Figure 8 The tire is shown in an exemplary first condition. Figure 7 and Figure 8 As shown, according to a non-limiting example, in a first condition, the tire 10 is rolling on a flat surface while carrying a load (i.e., normal operation), the non-pneumatic tire 10 is deformed, but adjacent spokes 200 do not contact each other. The lack of contact between adjacent spokes 200 during normal operation is desirable to avoid generating unnecessary stress in the structure of the non-pneumatic tire 10.

[0058] It is expected that the non-pneumatic tire 10 will be exposed to high-impact events during its life, such as striking a curb, a pothole, or other obstacle or road defect. During a high-impact event, the non-pneumatic tire 10 may deform at a significantly higher level than it would during normal operation. One example of a high-impact event is a non-pneumatic tire 10 striking a curb at low speed (e.g., striking a 6-inch (15-cm) curb at 5 mph (8 km / h). Another example of a high-impact event is a non-pneumatic tire 10 striking a stepped road defect at high speed (e.g., striking a 1-inch (2.5-cm) stepped road defect at 70 mph (113 km / h). These are merely examples and are not meant to limit the definition of a "high-impact event."

[0059] Figure 9 and Figure 10 FIG. 1 shows a tire in an exemplary second condition, which is different from the first condition. Figure 9 and Figure 10 As shown, according to a non-limiting example, in a second condition, the non-pneumatic tire 10 experiences a high-impact event in which the tire rolls over an uneven surface. According to one non-limiting example, the uneven surface is a road imperfection that protrudes above the ground or is pressed into the ground by a distance of 3 inches (8 cm). According to another non-limiting example, the uneven surface is a road imperfection that protrudes above the ground or is pressed into the ground by a distance of 4.5 inches (11 cm). According to yet another non-limiting example, the uneven surface is a road imperfection that protrudes above the ground or is pressed into the ground by a distance of 6 inches (15 cm).

[0060] The non-pneumatic tire 10 responds to a high-impact event by deforming so that adjacent spokes 200 contact one another. Surprisingly, it has been discovered that the contact between adjacent spokes 200 during a high-impact event significantly reduces the stress experienced by each spoke 200, compared to a non-pneumatic tire in which the spokes do not contact one another during a high-impact event. This reduction in stress in each spoke 200 is a result of the contact between adjacent spokes 200, as this contact distributes the load among the multiple spokes 200. In other words, rather than a single spoke 200 absorbing the load generated by a high-impact event, multiple spokes 200 share the same load, thereby reducing the peak load on any one spoke 200.

[0061] In the illustrated embodiment, the non-pneumatic tire 10 is arranged and configured such that at least three adjacent spokes 200 are in contact with each other simultaneously during a high-impact event, and the spokes 200 in contact are located adjacent to the obstacle or road defect causing the high-impact event. In alternative embodiments, the non-pneumatic tire may be arranged and configured such that a fewer or greater number of adjacent spokes are in contact with each other simultaneously during a high-impact event. In other alternative embodiments, the adjacent spokes in contact may be located anywhere along the circumferential direction of the tire (i.e., spaced apart from the obstacle or road defect causing the high-impact event).

[0062] The design parameters of the spokes 200 and other components of the non-pneumatic tire 10 may be varied to provide desired performance characteristics to the non-pneumatic tire 10. Preferably, these design parameters are selected so that contact between adjacent spokes 200 occurs before the spokes 200 begin to yield or experience any other form of damage.

[0063] The maximum distance d3 between the toggle portion 222 and the base plane p1, along a direction perpendicular to the base plane p1, affects spoke stiffness and when contact between adjacent spokes 200 will occur. Increasing the distance d3 physically moves each spoke 200 closer to adjacent spokes 200, thereby causing contact between adjacent spokes 200 to occur relatively sooner. Furthermore, increasing the distance d3 reduces the stiffness of the spokes 200, thereby increasing the amount of deflection for a given load, which increases the likelihood of contact between adjacent spokes 200. Reducing the distance d3 has the opposite effect and physically moves each spoke 200 away from adjacent spokes 200, thereby causing contact between adjacent spokes 200 to occur relatively later. Furthermore, reducing the distance d3 increases the stiffness of the spokes 200, thereby reducing the amount of deflection for a given load, which reduces the likelihood of contact between adjacent spokes 200.

[0064] The distance d2 between the transition portion 224 and the center of the first radius of curvature r1 of the toggle portion 222 in a direction parallel to the base plane p1 affects when contact with adjacent spokes 200 will occur. When the distance d2 is a large percentage of d1, this will cause contact between adjacent spokes 200 to occur relatively quickly. When the distance d2 is a small percentage of d1, this will cause contact between adjacent spokes 200 to occur relatively late.

[0065] The radius of curvature r1 of the toggle portion 222 affects when contact with adjacent spokes 200 occurs. Reducing the radius of curvature r1 causes contact between adjacent spokes 200 to occur relatively late, while increasing the radius of curvature r1 causes contact between adjacent spokes 200 to occur relatively soon. The spoke thickness t affects the stiffness of the spokes 200. Increasing the spoke thickness t increases the stiffness of the spokes 200, while decreasing the spoke thickness decreases the stiffness of the spokes 200.

[0066] Furthermore, it has been found that the vertical stiffness of the tire is affected by the combination of spoke thickness t and distance d3. Increasing distance d3 reduces tire stiffness, while decreasing distance d3 increases tire stiffness. Therefore, it has been found that to meet target tire stiffness values, spokes with greater thickness t should be combined with greater distance d3, while spokes with less thickness t should be combined with less distance d3.

[0067] Figure 11 10 is a flow chart illustrating an exemplary method for manufacturing a non-pneumatic tire. At 1010, a lower ring and an upper ring are provided. The lower ring has a first diameter, and the upper ring has a second diameter greater than the first diameter. At 1020, a plurality of spokes are formed. The spokes can be formed using hot stamping, cold forming, extrusion, rolling, bending, or any other desired method. In addition, the spokes can be formed using a variety of composite manufacturing techniques (e.g., resin transfer molding and high-pressure resin transfer molding). Other examples of methods for forming the spokes include wet lay-up and prepreg lamination. Each spoke extends between a first end and a second end. A toggle portion is located between the first end and the second end, and a transition portion is located between the first end and the toggle portion. The toggle portion and the transition portion are concavely curved in opposite facing directions. A foot extends from the transition portion.

[0068] At 1030, a flexure member is attached to the spokes. At 1040, the spokes are arranged into a first spoke set and a second spoke set axially spaced from the first spoke set. Furthermore, the plurality of spokes of the first spoke set are arranged to be concavely curved relative to a first circumferential direction of the tire, and the plurality of spokes of the second spoke set are arranged to be convexly curved relative to the first circumferential direction of the tire.

[0069] At 1050, the lower ring is connected to the upper ring using the first and second spoke groups. The foot of each spoke is attached to the lower ring to connect the first end of each spoke to the lower ring. The flex member is attached to the upper ring to connect the second end of each spoke to the upper ring.

[0070] In alternative embodiments, the aforementioned steps may occur in an order different from that specifically described.In other alternative embodiments, the method may include a greater or lesser number of steps.

[0071] Figure 12 and Figure 12a Another embodiment of a spoke 1200 is shown. Figure 12 and Figure 12a The spokes of 1200 with Figures 1 to 10 The spokes 200 in FIG. 1 are substantially identical except for the differences described herein. Therefore, similar features will be identified by similar numbers increased by a factor of "1000." Figures 1 to 10 In the illustrated spoke 200, the second connecting portion 228 is linear. In contrast, Figure 12 and Figure 12a The spoke 1200 has a curved second connecting portion 1228 with a radius of curvature r3. Compared with the linear second connecting portion, Figure 12 and Figure 12a The curved second connecting portion 1228 in the spoke 1200 significantly enhances the self-supporting behavior. According to an exemplary embodiment, the radius of curvature r3 is 10 inches to 50 inches (25 cm to 127 cm).

[0072] In addition to the above Figures 1 to 10 In addition to the design parameters and resulting changes in performance characteristics discussed in the illustrated spokes 200, Figure 12 and Figure 12a The radius of curvature r3 of the curved second connecting portion 1228 in the spoke 1200 can be varied to affect performance. The radius of curvature r3 of the curved second connecting portion 1228 and the length l of the flexure member 1216 挠曲 The two interact to influence the self-supporting properties. A smaller radius of curvature r3 of the curved second connecting portion 1228 reduces self-support, thereby increasing stress during a high-impact event. A larger radius of curvature r3 of the curved second connecting portion 1228 increases self-support, thereby reducing stress during a high-impact event. However, this stress reduction only occurs up to a point. As the radius of curvature r3 increases (to the limit where the radius of curvature r3 equals infinity, resulting in a straight second connecting portion), the effectiveness of the self-support begins to decrease again.

[0073] The length l of the flexure member 1216 挠曲 This affects its ability to apply torque at the ends of the spokes 1200. This torque acts to straighten the curved second connecting portion 1228 when the tire is rolling under normal load or subjected to a high impact event. Thus, it has been found that a curved second connecting portion 1228 having a smaller radius of curvature r3 is more effective than a second connecting portion having a longer length l 挠曲 The flexure member 1216 is best matched with the curved second connecting portion 1228 having a larger radius of curvature r3 and a shorter length l 挠曲 The flexure member 1216 is optimally matched. In addition to the length l of the flexure member 1216 挠曲 In addition, the ability of the flexure members 1216 to apply torque to the spokes 1200 is also affected by the stiffness of the material used to make the flexure members 1216. Therefore, when using softer materials, it is desirable to provide a flexure member 1216 having a longer length l. 挠曲 flexure member 1216, and when using a harder material, it is desirable to provide a flexure member 1216 having a shorter length l 挠曲 flexure member 1216.

[0074] The non-pneumatic tire described herein improves the robustness of non-pneumatic tires by providing an arrangement in which adjacent spokes contact each other during high-impact events. The contact between adjacent spokes results in load sharing across multiple spokes, significantly reducing the stress experienced by any individual spoke in the non-pneumatic tire. Consequently, the durability of the non-pneumatic tire is improved.

[0075] In the above-described embodiment, the feet 214 of the spokes 200 are initially substantially straight and bonded to the curved outer surface 24 of the lower ring 20. This bonding process forces the feet 214 to conform to the curvature of the outer surface 24. While this arrangement results in a relatively simple manufacturing process for the spokes 200 and lower ring 20, it can create other potential design difficulties. For example, in the flat foot embodiment, the primary applied force acting on the bond between the spokes and the ring is tension. This tension can lead to crack-type failures at the leading edge of the spokes. As another example, the rotational position of each spoke relative to the lower and upper rings cannot be adjusted without undesirably introducing prestress into the spokes.

[0076] Rotational adjustment of the spokes may be necessary to account for manufacturing tolerances. Ideally, each spoke of a non-pneumatic tire would be identical, including the dimensions of the various elements (e.g., the lengths of the foot, the first connecting portion, and the second connecting portion) and the angles between these elements (e.g., the angle between the foot and the first connecting portion or between the first connecting portion and the second connecting portion). However, in practice, it is unlikely that every spoke will be identical. Manufacturing guidelines acknowledge variations in the formed features of the product, such as material thickness and temper tolerances. Additionally, these manufacturing guidelines acknowledge variations in bend angle tolerances, with one guideline suggesting a tolerance of + / - one degree.

[0077] Figure 13 and Figure 14 Shows how this + / - one degree tolerance can affect the support structure of a non-pneumatic tire. Figures 1 to 6 Non-pneumatic tire implementation scheme structure Figure 13 and Figure 14 Therefore, like features will be indicated by like reference numerals.

[0078] Figure 13 and Figure 14 The first, second, and third spokes 200a, 200b, and 200c are shown. In the first and third spokes 200a, 200c, the angle θ between the foot 214 and the first connecting portion 226 is 1 degree smaller than the specified design value, while in the second spoke 200b, the angle θ is 1 degree larger than the design value. Figure 13The spokes 200 are shown when the feet 214 are connected to the lower ring 20 and the second end 208 of each spoke 200 is in a natural or resting position (i.e., the position of the second ends 208 of the spokes 200 in the absence of any external forces and before the flexure members 216 are attached to the upper ring 30). Figure 14 The spoke 200 is shown after the second end 208 of the spoke 20 has been moved to the desired position and the flexure member 216 is attached to the upper ring 30. Figure 13 As shown, having the angle between the foot 214 and the first connecting portion 226 be off specification by one degree can cause various problems, including causing the flexure member 216 to naturally rest above the upper ring 30 (second spoke 200b) or below the upper ring 30 (first 200a and third spokes 200c), and having irregular spacing between adjacent spokes 200. Some of these problems can be corrected by forcing the second end 208 of each spoke 200 into a desired position, as shown in FIG. Figure 14 As shown, doing so would undesirably introduce prestress into the spokes 200. In theory, each spoke 200 could be rotated about its first end 206 to correct these problems. However, in practice, such rotation is not possible due to the geometry between the flat foot 214 and the outer surface of the lower ring 20.

[0079] Figure 15 An alternative embodiment of a portion of a non-pneumatic tire is shown having features that alleviate the aforementioned issues regarding manufacturing tolerances. Figure 16 Show Figure 15 A single spoke of a non-pneumatic tire. Figure 15 and Figure 16 The arrangement shown in is essentially similar to Figures 1 to 6 , except for the differences described herein. Accordingly, like features will be identified by like numerals with the value "2000" added.

[0080] The non-pneumatic tire 2010 includes a support structure 2100 connecting a lower ring 2020 to an upper ring (not shown). The support structure 2100 is composed of a plurality of spokes 2200 arranged into a first spoke set and a second spoke set (not shown). The first spoke set and the second spoke set are offset and spaced apart from each other in the axial direction of the non-pneumatic tire 2010.

[0081] Reference Figure 16Each spoke 2200 extends between a first end 2206 and a second end 2208 and includes a first surface 2210 and a second surface 2212. A foot 2214 is provided toward the first end 2206 of the spoke 2200. A flexure member 2216 is provided at the second end 2208 of the spoke 2200. A toggle portion 2222 is provided between the first end 2206 and the second end 2208. A transition portion 2224 is provided between the toggle portion 2222 and the first end 2206. The foot 2214 extends from the transition portion 2224 toward the first end 2206 of the spoke 2200. A first connecting portion 2226 connects the transition portion 2224 to the toggle portion 2222, and a second connecting portion 2228 connects the toggle portion 2222 to the second end 2208 of the spoke 2200.

[0082] The outer surface 2024 of the lower ring 2020 is provided with a plurality of sector-shaped recesses 2025 (in the Figure 15 Only a single scalloped notch is shown in FIG. 2100. The first surface 2210 of the spoke 2200 at the foot 2214 is curved and has a radius of curvature r equal to that of the corresponding scalloped notch 2025. s The curvature radius r fp The scallops 2025 are spaced apart from one another in the circumferential direction of the non-pneumatic tire 2010 and are arranged into a first scallop group and a second scallop group (not shown). Similar to the spacing between the first and second spoke groups, the scallop groups are also offset and spaced apart from one another in the axial direction of the non-pneumatic tire 2010. The curved first surfaces 2210 of the spokes 2200 at the feet 2214 are coupled to corresponding scallops 2025 to attach the first ends of the spokes 2200 to the lower ring 2020. The flex members 2216 are coupled to the upper ring to connect the second ends 2208 of the spokes 2200 to the upper ring 2030. In alternative embodiments, the feet or flex members can be attached to the scallops or upper ring, respectively, using any desired arrangement. For example, a nut and bolt arrangement can be used to attach the curved first surfaces of the spokes at the feet to the corresponding scallops, wherein the bolts extend into through-holes provided in the spokes and the lower ring, thereby exposing threaded portions for receiving the nuts. This nut and bolt attachment can also be used to attach the flexure element to the upper ring.In other alternative embodiments, instead of separate sets of scallops, each scallop can extend continuously in the axial direction across the lower ring, and the spokes of the first and second spoke sets can share corresponding scallops.

[0083] The above arrangement helps address potential design issues associated with flat-foot spoke embodiments related to spoke manufacturing tolerances. Providing the non-pneumatic tire 2010 with spokes 2200 having curved feet 2214 and corresponding curved scallops 2205 on the lower ring 2020 causes the primary applied force on the joint between the spokes 2200 and the lower ring 2020 to be shear, rather than tension as in the flat-foot embodiment. This change reduces the likelihood of a crack-type failure mode occurring at the connection between the spokes 2200 and the lower ring 2020. Furthermore, the shear forces acting on the joint between the spokes 2200 and the lower ring 2020 cause the joint to enter a significantly more severe failure mode for most commonly used adhesives.

[0084] Additionally, the curved surfaces of the spokes 2200 and scalloped recesses 2025 allow for adjustment of the rotational position of each spoke 2200 relative to the lower ring 2020 and upper ring 2030 without pre-introducing stress into the spokes as is the case with flat foot embodiments. The curved surfaces of the spokes 2200 and scalloped recesses 2025 also allow for maintaining a constant adhesive gap during such rotational position adjustment.

[0085] It has been found that the radius of curvature r at the foot 2214 fp and the curvature radius r of the sector notch 2025 s Certain design principles should be followed in order to provide the above flexibility regarding rotational position adjustment. According to one exemplary design principle, the radius of curvature r at the foot 2214 is fp and the curvature radius r of the sector notch 2025 s Different from the curvature radius r of the outer surface of the lower ring 2020 lr .

[0086] In the illustrated embodiment, the curved second surface 2212 of the spoke 2200 at the foot 2214 and the scalloped recess 2025 are both convex relative to the inner surface 2023 of the lower ring 2020, and the curvature radius r at the foot 2214 is fp and the curvature radius r of the sector notch 2025 s are constant and equal to one another. Additionally, scalloped recesses 2025 are formed directly on lower ring 2020. In alternative embodiments, the second surfaces of the spokes may be raised relative to the inner surfaces of the spokes, and the lower ring may be provided with corresponding projections that also project relative to the inner surfaces of the spokes. In other alternative embodiments, the radius of curvature at the foot or the radius of curvature of the scalloped recesses or projections may be variable or different from one another. In yet another alternative embodiment, the scalloped recesses or projections may be formed on a sleeve secured to the outer surface of the lower ring.

[0087] Figures 17 to 19 Another embodiment of a non-pneumatic tire 3010 is shown. Figures 17 to 19The non-pneumatic tire 3010 is basically the same as Figures 15 and 16 The non-pneumatic tire of 2010 is identical to the tire of 2010 except for the differences described herein. Therefore, similar features will be identified by similar numbers increased by a factor of "1000".

[0088] The non-pneumatic tire 3010 includes a support structure 3100 connecting a lower ring 3020 to an upper ring 3030. The support structure 3100 is composed of a plurality of spokes 3200 arranged into a first spoke set and a second spoke set (not shown). In the illustrated embodiment, for clarity, only a single row of spokes 3200 is shown, and the spokes 3200 extend the entire axial width of the lower ring 3020. However, when two spoke sets are used, the lower ring 3020 can have an axial width that is at least twice the width of a single spoke.

[0089] Each spoke 3200 extends between a first end 3206 and a second end 3208. A foot 3214 is disposed toward the first end 3206 of the spoke 3200. A flexure member 3216 is disposed at the second end 3208 of the spoke 3200.

[0090] The lower ring 3020 is provided with a plurality of scallops 3024, the number of which is equal to the total number of spokes 3200 in the support structure 3100. The scallops 3024 are spaced apart from one another in the circumferential direction of the non-pneumatic tire 3010 and are arranged into a first scallop group and a second scallop group (not shown). Similar to the spacing between the first and second spoke groups, the scallop groups are also offset and spaced apart from one another in the axial direction of the non-pneumatic tire 3010. In an alternative embodiment, each scallop may extend continuously across the lower ring in the axial direction, and the spokes of the first and second spoke groups may share a corresponding scallop.

[0091] Mechanical fasteners 3080 connect the feet 3214 of the spokes 3200 to the corresponding scalloped notches 3205 to attach the first ends 3206 of the spokes 3200 to the lower ring 3020. An adhesive (not shown) can be used to strengthen the connection by bonding the components together. The adhesive can prevent wear between the components due to cyclic loading and can also prevent degradation (e.g., corrosion) due to exposure to environmental factors. Flexure members 3216 are attached to the upper ring 3030 to connect the second ends 3208 of the spokes 3200 to the upper ring 3030.

[0092] In the illustrated embodiment, the mechanical fastening device 3080 includes a clamping plate 3082 and two hexagon socket head screws 3084. The clamping plate 3082 includes an axial width substantially the same as the foot 3214 and a face 3086 having a radius of curvature substantially the same as the radius of curvature of the foot 3214. In alternative embodiments, the axial width of the clamping plate may be greater than or less than the axial width of the foot. In other alternative embodiments, the radius of curvature of the face of the clamping plate may be different than the radius of curvature of the foot.

[0093] Each mechanical fastening device 3080 is configured such that the head of the hexagon socket head screw 3084 is positioned radially inward of the lower ring 3020, and the threaded portion of the hexagon socket head screw 3084 extends through the lower ring 3020, the foot 3214, and the clamping plate 3082. The foot 3214 is provided with a through hole (not shown) to allow the passage of the hexagon socket head screw 3084. The through hole can be oversized or provided as a slot to allow adjustment of the position of the spoke 3200 relative to the lower ring 3020.

[0094] 3082, and the second fastener does not extend through the lower ring or the clamping plate. In another embodiment, the orientation of the fastening device can be reversed so that the head of the hexagon socket screw is positioned so that the clamping plate is radially outward and the threaded portion is engaged with the internal thread provided on the lower ring. In other embodiments, the hexagon socket screw can be arranged at any desired position, can be any desired size, and can have more or less screws. In another embodiment, the mechanical fastening device, the lower ring and / or the foot can be sized and configured so that the second fastener does not extend through the lower ring or the clamping plate. In another embodiment, any desired mechanical fastening device (e.g., a stud or set screw, rivet combined with a nut and a washer) can be used.

[0095] The mechanical fastening device 3080 distributes the load across the axial width of the foot 3214 of the spoke 3200, thereby providing a more stable structure and also providing a more rigid connection. In addition, the use of the clamping plate 3082 can facilitate the construction of the non-pneumatic tire 3010 by eliminating the need for a clamping device when only adhesive is used. In addition, the mechanical fastening device 3080 allows for the individual removal, maintenance, and installation of individual spokes.

[0096] Figure 20 and Figure 21 Another embodiment of a non-pneumatic tire 4010 is shown. Figure 20 and Figure 21 The non-pneumatic tire 4010 is basically the same as Figures 17 to 19 The non-pneumatic tire 3010 is identical to the non-pneumatic tire 3010 except for the differences described herein. Therefore, similar features will be identified by similar numbers increased by a factor of "1000".

[0097] The non-pneumatic tire 4010 includes a support structure 4100 connecting a lower ring 4020 to an upper ring 4030. The support structure 4100 is composed of a plurality of spokes 4200 arranged into a first spoke set and a second spoke set (not shown).

[0098] Each spoke 4200 extends between a first end 4206 and a second end 4208. A foot 4214 is provided toward the first end 4206 of the spoke 4200. A flexure member 4216 is provided at the second end 4208 of the spoke 4200. A toggle portion 4222 is provided between the first end 4206 and the second end 4208. A transition portion 4224 is provided between the toggle portion 4222 and the first end 4206. The foot 4214 extends from the transition portion 4224 toward the first end 4206 of the spoke 4200. A first connecting portion 4226 connects the transition portion 4224 to the toggle portion 4222, and a second connecting portion 4228 connects the toggle portion 4222 to the second end 4208 of the spoke 4200.

[0099] The lower ring 4020 is provided with a plurality of scallops 4024, the number of which is equal to the total number of spokes 4200 in the support structure 4100. The scallops 4024 are spaced apart from one another in the circumferential direction of the non-pneumatic tire 4010 and are arranged into a first scallop group and a second scallop group (not shown). Similar to the spacing between the first and second spoke groups, the scallop groups are also offset and spaced apart from one another in the axial direction of the non-pneumatic tire 4410. In an alternative embodiment, each scallop may extend continuously across the lower ring in the axial direction, and the spokes of the first and second spoke groups may share a corresponding scallop.

[0100] The mechanical fastening device 4080 connects the foot 4214 of the spoke 4200 to the corresponding scalloped notch 4205 to attach the first end 4206 of the spoke 4200 to the lower ring 4020. Figures 17 to 19 The mechanical fastening device 3080 shown in FIG is substantially the same and will not be described further. An adhesive (not shown) may be used to strengthen the connection by bonding the components together. The adhesive may prevent wear between the components due to cyclic loading and may also prevent degradation (e.g., corrosion) due to exposure to environmental factors. Flexure members 4216 are attached to the upper ring 4030 to connect the second ends 4208 of the spokes 4200 to the upper ring 4030.

[0101] As mentioned above, in Figures 1 to 19 In the embodiment of the present invention, the toggle portion and the transition portion are concavely curved in opposite facing directions relative to the single spoke. Figure 20 and Figure 21In an embodiment, the toggle portion 4222 and the transition portion 4224 are concavely curved in the same direction. This arrangement can provide benefits with respect to how the mechanical fastening device 4080 and adhesive (if used) are loaded and stressed. In particular, configuring the toggle portion 4222 and the transition portion 4224 to be concavely curved in the same direction can create a compression effect between the spokes 4200 and the lower ring 4020, which can reduce debonding issues and better distribute stress, thereby providing a more stable structure.

[0102] Although already Figures 1 to 21 Separate embodiments and variations are shown and described herein, but the disclosed features are not exclusive to each of the embodiments. Rather, various features may be combined between the embodiments as desired. For example, Figure 15 and Figure 16 The arrangement of the spoke bending feet shown in Figure 12 and Figure 12a The curved connecting portion combination of the spokes is shown in FIG.

[0103] To the extent that the terms "including" or "having" are used in the specification or claims, they are intended to be inclusive in a manner similar to how the term "comprising" is understood when used as a transitional word in the claims. Furthermore, to the extent that the term "or" is employed (e.g., A or B), the term is intended to mean "A or B or both." When applicants intend to indicate "only A or B but not both," the term "only A or B but not both" will be employed. Thus, the use of the term "or" herein is inclusive and not exclusive. See Bryan A. Garner, A Dictionary of Modern Legal Usage 624 (2d. Ed. 1995). Furthermore, to the extent the term "in" or "into" is used in the specification and claims, the term is intended to additionally mean "on" or "onto." Furthermore, to the extent the term "connected" is used in the specification or claims, the term is intended to mean not only "directly connected to," but also "indirectly connected to," such as connected through another component or components.

[0104] While the present application has been illustrated by way of description of its embodiments, and while the embodiments have been described in considerable detail, it is not the intention of the applicant to restrict or in any way limit the scope of the appended claims to such details. Additional advantages and modifications will be readily apparent to those skilled in the art. Therefore, the present application, in its broader aspects, is not limited to the specific details, representative apparatus and methods, and illustrative examples shown and described. For example, each spoke may be provided with a rubber coating to cushion the impact when contact occurs between adjacent spokes. Accordingly, departures from such details may be made without departing from the spirit or scope of the applicant's overall inventive concept.

Claims

1. A non-pneumatic tire, comprising: A lower ring provided with a plurality of scalloped recesses, each of the plurality of scalloped recesses having a first curved surface; an upper ring substantially coaxial with the lower ring; as well as A support structure connecting the lower ring to the upper ring, the support structure being comprised of a plurality of spokes arranged into a first spoke set and a second spoke set axially spaced from the first spoke set, each of the plurality of spokes comprising: connected to a first end of the lower ring; connected to the second end of the upper ring; a first surface and a second surface facing opposite the first surface, each of the first surface and the second surface extending between the first end and the second end; and A foot is disposed toward the first end of the spoke, the first surface of the spoke at the foot being a second curved surface, the second curved surface being attached to the first curved surface of one of the plurality of scalloped recesses to connect the first end of the spoke to the lower ring. 2 . The non-pneumatic tire according to claim 1 , wherein each of the first curved surface and the second curved surface is convex relative to an inner surface of the lower ring.

3. The non-pneumatic tire of claim 1, wherein the first curved surface has a first radius of curvature and the second curved surface has a second radius of curvature, and wherein at least one of the first radius of curvature and the second radius of curvature is constant.

4. The non-pneumatic tire of claim 1, wherein the first curved surface has a first radius of curvature and the second curved surface has a second radius of curvature, and wherein the first radius of curvature is equal to the second radius of curvature.

5. The non-pneumatic tire of claim 1 , wherein the first curved surface has a first radius of curvature, the second curved surface has a second radius of curvature, and the outer surface of the lower ring has a third radius of curvature, and wherein each of the first radius of curvature and the second radius of curvature is different from the third radius of curvature.

6. The non-pneumatic tire of claim 1, wherein the spokes of the first spoke set are concavely curved relative to a first circumferential direction of the tire, and the spokes of the second spoke set are convexly curved relative to the first circumferential direction of the tire.

7. The non-pneumatic tire of claim 1 , wherein each of the plurality of spokes comprises: a toggle portion between the first end and the second end; as well as a transition portion between the first end and the toggle portion; Wherein the toggle portion and the transition portion are concavely curved in oppositely facing directions.

8. The non-pneumatic tire of claim 1 , wherein each of the plurality of spokes comprises: a toggle portion between the first end and the second end; as well as a transition portion between the first end and the toggle portion; Wherein the toggle portion and the transition portion are concavely curved in the same direction.

9. The non-pneumatic tire of claim 1, wherein each of the plurality of spokes further comprises a flex member attached to the spoke and the upper ring to connect the second end of the spoke to the upper ring.

10. The non-pneumatic tire according to claim 1, wherein the non-pneumatic tire is arranged and constructed so that adjacent spokes among the plurality of spokes do not contact each other when the non-pneumatic tire is in a first state, and so that adjacent spokes among the plurality of spokes contact each other when the non-pneumatic tire is in a second state, the first state being when the tire is rolling on a flat surface, the second state being different from the first state.

11. A method of manufacturing a non-pneumatic tire, the method comprising the steps of: providing a lower ring having a first diameter and an upper ring having a second diameter greater than the first diameter; forming a plurality of scalloped recesses on the lower ring, each of the plurality of scalloped recesses having a first curved surface; forming a plurality of spokes, each spoke having a first surface and a second surface facing opposite the first surface, the first surface and the second surface each extending between a first end and a second end, the step of forming the plurality of spokes comprising providing a foot portion toward the first end of the spoke, the first surface of the spoke at the foot portion being a second curved surface; The lower ring is connected to the upper ring with the first spoke group and the second spoke group, and the step of connecting the lower ring to the upper ring includes attaching the second curved surface of the spoke at the foot to the first curved surface of one of the plurality of scalloped recesses to connect the first end of the spoke to the lower ring and the second end of the spoke to the upper ring.

12. The method for manufacturing a non-pneumatic tire according to claim 11, wherein forming a plurality of scalloped recesses comprises disposing the first curved surface as a first convex surface relative to an inner surface of the lower ring, and wherein forming a plurality of spokes comprises disposing the first surface of the spoke at the foot as a second convex surface relative to the inner surface of the lower ring.

13. The method of manufacturing a non-pneumatic tire according to claim 11, wherein forming a plurality of scalloped notches comprises providing a first curved surface with a first radius of curvature, and wherein forming a plurality of spokes comprises providing the first surface of the spokes at the foot with a second radius of curvature, wherein the first radius of curvature and the second radius of curvature are different from a third radius of curvature of the outer surface of the lower ring.

14. The method of manufacturing a non-pneumatic tire according to claim 11, wherein arranging the plurality of spokes into the first spoke group and the second spoke group comprises: The spokes of the first spoke set are arranged to be concavely curved relative to a first circumferential direction of the tire, and the spokes of the second spoke set are arranged to be convexly curved relative to the first circumferential direction of the tire.

15. The method for manufacturing a non-pneumatic tire according to claim 11, further comprising the steps of: Attaching a flex member to each spoke and attaching the flex member to the upper ring, wherein attaching the flex member to the upper ring connects the second ends of the spokes to the upper ring during connection of the lower ring to the upper ring.

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