Midsole with graded response

Abstract

A sole structure for an article of footwear includes a midsole having four stacked polymer sheets bonded to one another to define a first cushioning layer, a second cushioning layer, and a third cushioning layer. Each cushioning layer includes a sealed chamber that keeps a gas isolated from each other sealed chamber. The joints between adjacent ones of the sheets are arranged such that the third cushioning layer is stacked directly on top of the first cushioning layer, wherein the second cushioning layer is adjacent to both the first cushioning layer and the third cushioning layer, and the sealed chamber of the second cushioning layer includes a plurality of elongated segments, each elongated segment extending lengthwise through a longitudinal centerline of the midsole at a respective acute angle relative to the longitudinal centerline.

Description

[0001] This application is a divisional application of the invention patent application with application date of May 18, 2018, application number 201880034269.8, and invention name “Sole midsole with graded response”.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] P20J55966AZ

[0004] This application claims the benefit of priority to U.S. Provisional Application No. 62 / 510,003, filed May 23, 2017, which is hereby incorporated by reference in its entirety. Technical Field

[0005] The present teachings generally include a sole structure for an article of footwear that includes a midsole. background

[0006] Articles of footwear typically include a sole structure that is configured to be positioned under a wearer's foot to space the foot from the ground. The sole structure in athletic footwear is typically configured to provide cushioning, motion control, and / or rebound. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 is a schematic illustration of a side view of an embodiment of an article of footwear having a sole structure.

[0008] Figure 2 yes Figure 1 Schematic illustration of a bottom view of a midsole of an article of footwear.

[0009] Figure 3 is Figure 2 The line 3-3 in Figure 1 Schematic illustration of a cross-sectional view of a sole structure of an article of footwear, the sole structure including a midsole and an outsole.

[0010] Figure 4 It is in the first compression stage Figure 3 Schematic illustration of a cross-sectional view of a sole structure.

[0011] Figure 5 It is in the second compression stage Figure 3 Schematic illustration of a cross-sectional view of a sole structure.

[0012] Figure 6 It is in the third compression stage Figure 3 Schematic illustration of a cross-sectional view of a sole structure.

[0013] Figure 7 yes Figures 4 to 6 Plot of force versus displacement during dynamic compressive loading of a sole structure.

[0014] Figure 8 yes Figure 1 Schematic illustration of a top view of an alternative embodiment of a midsole of an article of footwear.

[0015] Fig. 9 It is captured at line 9-9 Figure 8 Schematic illustration of a cross-sectional partial view of a midsole.

[0016] describe

[0017] A kind of footwear article comprises a sole structure with a midsole, and the midsole has a plurality of cushioning layers of a sealed chamber containing gas. The cushioning layers can each have different compression stiffnesses, and can be arranged relative to each other so that the midsole absorbs compression loads (such as dynamic compression loads generated due to impact with the ground) in a stage of progressive cushioning (called staged or graded cushioning) according to the relative stiffness value of the layer. Underfoot loads are "quantified" or "staged" to the wearer, wherein each stage has a different effective stiffness. In one example, the midsole initially provides a low, linear rate of change of load to displacement (i.e., compression stiffness), followed by a higher, possibly nonlinear rate of change, and then a faster, exponentially increasing rate of change. The sole structure provides graded cushioning while being lightweight and flexible. In addition, multiple embodiments can present unloading performance (i.e., performance when dynamic compression force is removed) that provides significant energy return.

[0018] The filling pressure of the corresponding sealed chamber of the buffer layer can be selected to provide a variety of sequential load absorption by the buffer layer, thereby affecting the feel or "ride" of the sole structure. The filling pressure affects the stiffness of the buffer layer, wherein a higher filling pressure results in a greater stiffness. In an exemplary embodiment, the first buffer layer has a first stiffness, the second buffer layer has a second stiffness greater than the first stiffness, and the third buffer layer has a third stiffness. The dynamic compression load on the sole structure is absorbed by the first buffer layer, the second buffer layer, and the third buffer layer in turn according to the relative magnitudes of the first stiffness, the second stiffness, and the third stiffness. As used herein, "stiffness" is the rate of change of load to displacement under compression of the buffer layer. The buffer layer can have a constant stiffness (i.e., a linear rate of change of load to displacement), a nonlinear stiffness (such as an exponentially increasing rate of change of load to displacement under compression), or can have a rate of change that is initially linear and changes to nonlinear (or initially nonlinear and changes to linear). When two or more cushioning layers are compressed in series or in parallel, the stiffness of the midsole may have an effective stiffness over a portion of the displacement range that is based on the stiffness values ​​of more than one cushioning layer.

[0019] When in an unloaded state (such as at a specific inflation pressure or at ambient pressure), each sealed cell holds a gas (e.g., air, nitrogen, or another gas) at a predetermined pressure. For example, such a sealed cell may be bounded by and defined by two adjacent polymer sheets that are impermeable to gas. The inflated sealed cells are empty (i.e., "structure-less"), but can provide cushioning when compressed, with a significant weight reduction compared to most foams. As used herein, a "predetermined pressure" is at a predetermined reference temperature.

[0020] More specifically, a sole structure for an article of footwear includes a midsole having four stacked polymer sheets bonded to each other to define a first cushioning layer, a second cushioning layer, and a third cushioning layer, each cushioning layer including a sealed chamber that keeps gas isolated from each other sealed chamber. For example, the four stacked polymer sheets may include a first sheet at a surface facing the ground of the midsole, a second sheet stacked on the first sheet, a third sheet stacked on the second sheet, and a fourth sheet stacked on the third sheet at a surface facing the foot of the midsole. The joint between adjacent sheets in the sheet is arranged so that the third cushioning layer is directly stacked on the first cushioning layer, wherein the second cushioning layer is adjacent to both the first cushioning layer and the third cushioning layer. The sealed chamber of the second cushioning layer includes a plurality of elongated segments, each of which extends lengthwise through the longitudinal midline of the midsole at a corresponding acute angle relative to the longitudinal midline. The elongated segments are subchambers of the sealed chamber of the second cushioning layer. They may be tubular in shape, and are also referred to herein as tubular subchambers. The elongated segments provide torsional stiffness to the midsole by extending through the longitudinal midline, particularly where the elongated segments extend a majority of the width of the midsole, such as from the lateral extremity to the medial extremity. As described herein, by extending at an acute angle relative to the longitudinal midline, the elongated segments facilitate bending in a desired location and direction.

[0021] In one or more embodiments, the elongated segments may include a first elongated segment angled forward in a direction from a lateral edge of the midsole to a medial edge of the midsole, and a second elongated segment angled forward in a direction from the medial edge to the lateral edge and intersecting the first elongated segment. The first elongated segment and the second elongated segment establish a bending axis about which the midsole bends.

[0022] For example, in one aspect, the first elongated segment and the second elongated segment can together define an X-shape in the forefoot area of ​​the midsole. In addition, the joint between the second piece and the third piece can include a plurality of V-shaped joints in the forefoot area that are adjacent to the first elongated segment and the second elongated segment. The V-shaped joints help define the X-shape of the elongated segments.

[0023] On the other hand, the first elongated section and the second elongated section together define an X-shape in the heel area of ​​the midsole. In such an embodiment, the joint between the second sheet and the third sheet may include a plurality of V-shaped joints in the heel area that are adjacent to the first elongated section and the second elongated section.

[0024] In yet another aspect, the joint between the second sheet and the third sheet comprises a plurality of elongated joints in the midsole region that are angled forward from the lateral edge of the midsole through the longitudinal midline to the medial edge of the midsole. In other embodiments, the joint between the second sheet and the third sheet comprises a plurality of V-shaped joints in the midsole region that are adjacent to at least one of the elongated segments in the midsole region such that at least one of the elongated segments in the midsole region is V-shaped.

[0025] The first cushioning layer and the second cushioning layer may be adjacent to the ground-facing surface of the midsole, and the sole structure may also include an outsole fixed to the ground-facing surface. The midsole and the outsole are constructed in a complementary manner so that when the cushioning layer is compressed, the outsole provides an increased ground contact area. For example, the outsole may be thicker under the first cushioning layer than under the second cushioning layer. Under a first compressive load, the thicker portion of the outsole under the first cushioning layer protrudes more from the midsole than the thinner portion of the outsole under the second cushioning layer, and is flush with the thinner portion under a larger, second compressive load. Therefore, under a larger load, the ground contact area of ​​the outsole is larger, thereby providing greater load distribution and traction friction.

[0026] The outsole may include a lug disposed directly below the first buffer layer. The lug is narrower than the corresponding portion of the first buffer layer disposed directly thereon. Therefore, sufficient compressive loads applied to the midsole may compress the first buffer layer around the lug so that the lug is nested in the midsole below the first buffer layer. In some embodiments, the lug includes a central lug and a side lug. The central lug is centered below the corresponding portion of the first buffer layer, and the side lug is disposed adjacent to the central lug. Under a first compressive load (such as a relatively low load or no load), the surface of the midsole facing the ground is arched below the first buffer layer so that the central lug is lower than the side lug. Under a second compressive load greater than the first load, the first buffer layer compresses and moves the side lugs to be flush with the central lug, thereby increasing the ground contact area of ​​the outsole. Therefore, the dynamic compressive load that may occur during running or jumping increases the ground contact area of ​​the outsole.

[0027] The joints between adjacent sheets of the four stacked polymer sheets can be arranged so that the second buffer layer is directly superimposed only on the first portion of the first buffer layer, and the third buffer layer is directly superimposed only on the remaining portion of the first buffer layer. Therefore, the first buffer layer absorbs the dynamic compressive load in series with the second buffer layer at the first portion of the first buffer layer, and the first buffer layer absorbs the dynamic compressive load in parallel with the second buffer layer and in series with the third buffer layer at the remaining portion of the first buffer layer.

[0028] The joint can also be arranged such that the first cushioning layer and the second cushioning layer are disposed adjacent to the ground-facing surface of the midsole, and the third cushioning layer is displaced from the ground-facing surface of the midsole by the first cushioning layer and the second cushioning layer. Thus, the second cushioning layer and the third cushioning layer define the foot-facing surface of the midsole, and the first cushioning layer is displaced from the foot-facing surface of the midsole by the second cushioning layer and the third cushioning layer.

[0029] A sole structure for footwear, comprising a midsole having four stacked polymer sheets bonded to each other to define a first sealed chamber defined by a first polymer sheet and a second polymer sheet, a second sealed chamber defined by a second polymer sheet and a third polymer sheet, and a third sealed chamber defined by a third polymer sheet and a fourth polymer sheet. The second polymer sheet and the third polymer sheet are bonded to each other at a joint between the first sealed chamber and the third sealed chamber, at least some of which have an outer periphery with a closed shape. The second sealed chamber is adjacent to the outer periphery. The first sealed chamber and the second sealed chamber are arranged adjacent to the ground-facing surface of the midsole. The outsole is fixed to the ground-facing surface of the midsole. The outsole has a relatively thick portion below the first sealed chamber and a relatively thin portion below the second sealed chamber, so that under a first compressive load, only the relatively thick portion forms a ground contact surface, and under a second compressive load greater than the first compressive load, the first sealed chamber is compressed so that both the relatively thick portion and the relatively thin portion form a ground contact surface.

[0030] In an embodiment, the outsole includes a lug disposed directly below the first sealed chamber. The lug is narrower than a corresponding portion of the first sealed chamber disposed directly above it, so that the first sealed chamber compresses around the lug under the second compressive load. The first sealed chamber and the second sealed chamber include a plurality of tubular subchambers that extend lengthwise at least partially transversely through the midsole at a surface facing the ground.

[0031] In an embodiment, the first of the tubular subchambers of the second sealed chamber extends from the medial edge of the midsole to the lateral edge of the midsole at a first acute angle relative to the longitudinal centerline of the midsole without being interrupted by the first sealed chamber and the third sealed chamber, thereby establishing a first bending axis around which the midsole bends. The second of the tubular subchambers of the second sealed chamber extends from the medial edge of the midsole to the lateral edge of the midsole at a second acute angle relative to the longitudinal centerline of the midsole without being interrupted by the first sealed chamber and the third sealed chamber, thereby establishing a second bending axis around which the midsole bends. The first bending axis and the second bending axis intersect in the forefoot region of the midsole. When pivoting movement is required around the placed forefoot, the midsole will tend to bend at the bending axis. In the same or different embodiments, similar first bending axes and second bending axes can be set in the heel region. In some embodiments, the tubular subchamber extends substantially from a lateral edge of the midsole through a longitudinal centerline of the midsole to a medial edge of the midsole in a midfoot region of the midsole, thereby providing torsional stiffness in the midfoot region.

[0032] In an embodiment with four polymer sheets, the second polymer sheet and the third polymer sheet tie the first polymer sheet to the fourth polymer sheet via a webbing. In other words, the first polymer sheet and the second polymer sheet together extend from the inner surface of the first polymer sheet to the inner surface of the fourth polymer sheet, and thereby limit the height of the midsole from the first polymer sheet to the fourth polymer sheet.

[0033] In a plurality of embodiments, the first sealed chamber is filled to a first predetermined pressure, the second sealed chamber is filled to a second predetermined pressure, and the third sealed chamber is filled to a third predetermined pressure. The third predetermined pressure may be lower than the second predetermined pressure, the same as the second predetermined pressure, lower than the first predetermined pressure, or higher than the first predetermined pressure. In one embodiment, the third predetermined pressure is lower than both the first predetermined pressure and the second predetermined pressure. Because the third cushioning layer is closer to the outer surface of the midsole facing the foot than the first cushioning layer, such an embodiment can provide a soft feeling under the foot. In another embodiment, the third predetermined pressure is less than the second predetermined pressure and higher than the first predetermined pressure. Both embodiments sandwich at least most of the second sealed chamber between the first sealed chamber and the second sealed chamber, isolating the second sealed chamber of the more rigid second cushioning layer from the outer surface of the midsole facing the foot and facing the ground.

[0034] In an embodiment, the first polymer sheet and the second polymer sheet are bonded to each other along the outer peripheral portion of the lower side of the second sealed chamber, so that the first sealed chamber is located below the second sealed chamber only inside the outer peripheral portion of the lower side of the second sealed chamber. In addition, the third polymer sheet and the fourth polymer sheet are bonded to each other along the outer peripheral portion of the top side of the second sealed chamber, so that the third sealed chamber is superimposed on the second sealed chamber only inside the outer peripheral portion of the top side of the second sealed chamber. In such an embodiment, the outer periphery of the midsole has a thickness of two sheets at these outer peripheral portions of the lower side and the top side, which prevents the bulging tendency of the thinner, single-sheet thickness. The outer peripheral flange has a thickness of four sheets.

[0035] Therefore, the first and third cushioning layers are arranged in series with each other and in parallel with the second cushioning layer. If the second sealed chamber has the highest pressure of the three sealed chambers in the unloaded state, it stabilizes the midsole around the stacked, less rigid first and third chambers.

[0036] The above features and advantages of the present teachings and other features and advantages will become apparent from the following detailed description of modes for carrying out the present teachings when taken in conjunction with the accompanying drawings.

[0037] Referring to the drawings, wherein like reference numerals refer to like parts throughout the several views, Figures 1 to 6 An embodiment of an article of footwear 110 is shown having a sole structure 112 having a midsole 118 within the scope of the present teachings. The midsole 118 has a first cushioning layer 122, a second cushioning layer 124, and a third cushioning layer 126, such as Figures 3 to 6 1. As best shown in FIG. 1, at least some of the plurality of cushioning layers 122, 124, 126 have different stiffnesses. The plurality of cushioning layers 122, 124, 126 are arranged relative to one another so that the midsole 118 sequentially absorbs dynamic compressive loads (such as those caused by impact with the ground) in stages of progressive cushioning according to the relative stiffnesses of the cushioning layers. None of the cushioning layers 122, 124, 126 are foams. As used herein, the "stiffness" of a cushioning layer is the rate of change of a compressive load (e.g., force in Newtons) relative to a displacement of the cushioning layer (e.g., displacement in millimeters along an axis of the compressive load).

[0038] The midsole 118 includes four stacked polymer sheets: a first polymer sheet 132, a second polymer sheet 134, a third polymer sheet 136, and a fourth polymer sheet 137. The sheets are bonded to each other to define a first cushioning layer 122, a second cushioning layer 124, and a third cushioning layer 126. The first cushioning layer 122 is formed by the first polymer sheet 132 and the second polymer sheet 134, which form and define a first sealed chamber 138 defined by the first polymer sheet 132 and the second polymer sheet 134. The second polymer sheet 134 and the third polymer sheet 136 form and define a second sealed chamber 140 defined by the second polymer sheet 134 and the third polymer sheet 136. The third cushioning layer 126 includes a third sealed chamber 141 formed, bounded, and defined by the third polymer sheet 136 and the fourth polymer sheet 137. The first polymer sheet 132, the second polymer sheet 134, the third polymer sheet 136, and the fourth polymer sheet 137 are materials that are impermeable to gas, such as air, nitrogen, or other gases. This enables the first sealed chamber 138 to maintain the gas at a first predetermined pressure, the second sealed chamber 140 to maintain the gas at a second predetermined pressure, and the third sealed chamber 141 to maintain the gas at a third predetermined pressure.

[0039] Figure 2 FIG. 1 is a bottom view of the midsole 118 with the outsole 120 removed. Figure 1 and Figure 2 As is evident in FIG. 1 , midsole 118 is a full-length, unitary midsole that includes forefoot region 113 , midfoot region 115 , and heel region 117 .

[0040] The first sealed chamber 138 and the third sealed chamber 141 have the same Figure 2 The second sealed chamber 140 has a plurality of closed shapes shown in the figure which are substantially the same shape (eg, a V-shape, a W-shape, and a triangle shape with rounding). Figure 2 The remaining area in (i.e., surrounding Figure 2 The shape of the shoe (i) includes a perimeter of each of the closed shapes in the shoe and extends to an area of ​​the perimeter of the midsole 118.

[0041] Optionally, Figure 1 The foam or hard polymer support 143 shown in FIG. 1 forms a side wall that surrounds the outer periphery of the midsole 118 and extends upwardly and around the heel area 117 of the upper 114. The outer surface 130 ( Figure 3 144 ) can be secured directly to a lower surface of the upper 114, or to a strobel beneath the upper 114, or the support member 143 can extend beneath the foot and overlying the outer surface 130 facing the foot, with the fourth polymer sheet 137 secured to the support member 143.

[0042] refer to Figure 3 , four polymer sheets 132, 134, 136, 137 are stacked such that when article of footwear 110 is worn on foot 16, second cushioning layer 124 partially overlies first cushioning layer 122, and third cushioning layer 126 directly overlies a portion of first cushioning layer 122 and partially overlies second cushioning layer 124. Thus, sole structure 112 is arranged such that third cushioning layer 126 is closest to foot 16 and first cushioning layer 122 is closest to ground surface G, such as when outsole 120 is in contact with ground surface G. First cushioning layer 122 and second cushioning layer 124 define ground-facing outer surface 128 of midsole 118. Only first polymer sheet 132 is at ground-facing outer surface 128, but the contour of ground-facing surface 128 is defined by first sealed chamber 138 and second sealed chamber 140. Third cushioning layer 126 is completely displaced from ground-facing outer surface 128 by first cushioning layer 122 and second cushioning layer 124. Second cushioning layer 124 and third cushioning layer 126 together define a foot-facing exterior surface 130 of midsole 118. Only fourth polymer sheet 137 is at foot-facing exterior surface 130, but the contour of foot-facing exterior surface 130 is defined by second sealed chamber 140 and third sealed chamber 141. First cushioning layer 122 is completely displaced from foot-facing exterior surface 130 by second cushioning layer 124 and third cushioning layer 126.

[0043] The first polymer sheet 132, the second polymer sheet 134, the third polymer sheet 136 and the fourth polymer sheet 137 can be formed by various materials, including a variety of polymers that can resiliently retain fluids (such as air or another gas). The example of the polymer material for polymer sheets 132, 134, 136 and 137 includes thermoplastic urethane, polyurethane, polyester, polyester polyurethane and polyether polyurethane. In addition, polymer sheets 132, 134, 136 and 137 can each be formed by layers of different materials. In one embodiment, each polymer sheet 132, 134, 136 and 137 is formed by a film, and the film has one or more thermoplastic polyurethane layers, and the thermoplastic polyurethane layer has one or more barrier layers of a copolymer of ethylene and vinyl alcohol (EVOH), and the barrier layer is impermeable for the pressurized fluid contained therein, as disclosed in U.S. Patent No. 6,082,025, which is incorporated by reference in its entirety. Each polymer sheet 132, 134, 136 and 137 may also be formed of a material comprising alternating layers of thermoplastic polyurethane and ethylene-vinyl alcohol copolymer, as disclosed in U.S. Pat. Nos. 5,713,141 and 5,952,065 to Mitchell et al., both of which are incorporated by reference in their entirety. Alternatively, the layers may include ethylene-vinyl alcohol copolymer, thermoplastic polyurethane, and regrind material of ethylene-vinyl alcohol copolymer and thermoplastic polyurethane.

[0044] The polymer sheets 132, 134, 136, and 137 may also each be a flexible microlayer film comprising alternating layers of a gas barrier material and an elastomeric material, as disclosed in U.S. Pat. Nos. 6,082,025 and 6,127,026 to Bonk et al., both of which are incorporated by reference in their entirety. Other suitable materials for polymer sheets 132, 134, 136, and 137 are disclosed in U.S. Pat. Nos. 4,183,156 and 4,219,945 to Rudy, both of which are incorporated by reference in their entirety. Other suitable materials for polymer sheets 132, 134, 136, and 137 include thermoplastic films containing crystalline materials (such as disclosed in U.S. Pat. Nos. 4,936,029 and 5,042,176 to Rudy), and polyurethanes containing polyester polyols (such as disclosed in U.S. Pat. Nos. 6,013,340, 6,203,868, and 6,321,465 to Bonk et al.), which are incorporated by reference in their entirety. When selecting materials for polymer sheets 132, 134, 136, and 137, engineering properties such as tensile strength, stretching properties, fatigue characteristics, dynamic modulus, and loss factor can be considered. The thickness of polymer sheets 132, 134, 136, and 137 can be selected to provide these properties.

[0045] The first sealed chamber 138, the second sealed chamber 140, and the third sealed chamber 141 are not in fluid communication with each other. In other words, the first sealed chamber 138 and the second sealed chamber 140 are sealed from each other by the second polymer sheet 134. The second sealed chamber 140 and the third sealed chamber 141 are sealed from each other by the third polymer sheet 136. This allows the first sealed chamber 138, the second sealed chamber 140, and the third sealed chamber 141 to maintain the gas at pressures that may be different from each other. When the midsole 118 is in an unloaded state, Figure 3The first sealed chamber 138 shown in the figure keeps the gas at a first predetermined pressure, the second sealed chamber 140 keeps the gas at a second predetermined pressure in the unloaded state, and the third sealed chamber 141 keeps the gas at a third predetermined pressure in the unloaded state. The unloaded state is the state of the midsole 118 when the midsole 118 is not in a steady state or under dynamic loading. For example, the unloaded state is the state of the midsole 118 when the midsole 118 is not subjected to any load (such as when the foot 16 is not on the midsole 118). In the embodiment shown, the second predetermined pressure is higher than the first predetermined pressure. The third predetermined pressure may be different from the first predetermined pressure and / or the second predetermined pressure. The lowest one of the predetermined pressures, such as the first predetermined pressure, may be an ambient pressure rather than a filling pressure. In a non-limiting example, the first predetermined pressure is 7 pounds per square inch (psi), the second predetermined pressure is 20psi, and the third predetermined pressure is greater than 20psi. The predetermined pressure may be the filling pressure of the gas just filled in the corresponding sealed chambers 138, 140, 141 before the chamber is finally sealed. The lowest of the predetermined pressures, such as the first predetermined pressure, may be the ambient pressure rather than the charge pressure.

[0046] The first buffer layer 122 has a first stiffness K1, which is determined by the properties of the first polymer sheet 132 and the second polymer sheet 134 (such as their thickness and material) and by the first predetermined pressure in the first sealed chamber 138. The second buffer layer 124 has a second stiffness K2, which is determined by the properties of the second polymer sheet 134 and the third polymer sheet 136 (such as their thickness and material) and by the second predetermined pressure in the second sealed chamber 140. The third buffer layer 126 has a third stiffness K3, which is determined by the properties of the third polymer sheet 136 and the fourth polymer sheet 137 (such as their thickness and material) and by the third predetermined pressure in the third sealed chamber 141.

[0047] The dynamic compressive load on sole structure 112 is caused by the impact of article of footwear 110 with the ground. Figure 4 1 is indicated by a footbed load FL and an opposing ground load GL of a person wearing article of footwear 110. Footbed load FL acts on foot-facing exterior surface 130, and ground load GL acts on ground contacting surface G of outsole 120, similar to that shown with reference to the corresponding surface of article of footwear 110. Footbed load FL is indicated by Figure 3 The ground load GL is represented by all downward arrows on the outer surface 130 facing the foot. Figure 3120 of the shoe outsole 120. The dynamic compressive load is absorbed by the first cushioning layer 122, the second cushioning layer 124, and the third cushioning layer 126 in order from the smallest stiffness to the largest stiffness according to the relative magnitude of the first stiffness K1, the second stiffness K2, and the third stiffness K3. In the illustrated embodiment, the magnitude of the stiffness of the cushioning layers 122, 124, 126 increases in the following order: the first stiffness K1, the third stiffness K3, and the second stiffness K2, but any combination of relative pressures is possible.

[0048] The joints 142 between adjacent sheets of the sheets 132, 134, 136, 137 are arranged so that the third buffer layer 126 is stacked directly above the first buffer layer 122, wherein the second buffer layer 124 is adjacent to both the first buffer layer 122 and the third buffer layer 126. The second polymer sheet 134 and the third polymer sheet 136 are bonded to each other at the joints 142 between the first sealed chamber 138 and the third sealed chamber 141, and each joint 142 has an outer periphery 144 with a closed shape. The joints 142 are also referred to herein as ties. Figure 3 In the embodiment shown in the cross section of FIG. 1 , the closed shape is a sawtooth or "W" shape, such as Figure 2 , where the tie portion 142 is visible through the transparent and lowest first polymer sheet 132. Figure 2 1 and 2. A plurality of bonds 142 are shown connecting the second polymer sheet 134 and the third polymer sheet 136, such as at a portion defined by a perimeter 144. The discrete bonds 142 have a variety of shapes that mate with one another. Figure 2 The shaded area surrounding the joint 142 is Figure 3 The outer periphery of the separated subchambers of the first sealed chamber 138 disposed above the plurality of joints 142 in the bottom view of the embodiment is the same as the outer periphery of the separated subchambers of the third sealed chamber 141 disposed below the joints 142 in the bottom view. The subchambers of the first sealed chamber 138 are not in fluid communication with each other. The subchambers of the third sealed chamber 141 are not in fluid communication with each other. The second sealed chamber 140 is Figure 2 Zhongyou Figure 2 The bottom view of the shoe midsole 118 is indicated by the entire remaining space surrounding the plurality of discrete joints 142. The subchambers of the second sealed chamber 140 are in fluid communication with each other. All four of the first polymer sheet 132, the second polymer sheet 134, the third polymer sheet 136, and the fourth polymer sheet 137 are bonded to each other at a peripheral flange 146 at the outer periphery of the midsole 118.

[0049] Due to the force of the internal pressure on the inner surfaces of the polymer sheets 132, 134 that define the first sealed chamber 138, the unrestricted portion of the first sealed chamber 138 tends to adopt a rounded shape, also known as a dome shape. As shown, each segment of the ground-facing outer surface 128 below the first sealed chamber 138 is at least slightly rounded and is substantially centered below the tie 142. Therefore, the rounded portion of the ground-facing outer surface 128 is also centered below the higher pressure second sealed chamber 140 of the second buffer layer 124 and is stabilized by the higher pressure second sealed chamber 140. The second sealed chamber 140 is adjacent to and surrounds Figure 2 The outer perimeter 144 of all closed-shape bonds 142 between the second polymer sheet 134 and the third polymer sheet 136 shown in FIG. 1 and all surfaces of the first sealed chamber 138 except the dome-shaped, ground-facing outer surface 128 .

[0050] Unlike the second sealed chamber 140, the first sealed chamber 138 is Figure 8 The first sealed chamber 138 is provided with a plurality of separate subchambers (i.e., also referred to as pods) in a separated closed shape, which are not fluidically connected to each other, or to the second sealed chamber 140 or the third chamber 141. This allows the separate, discrete subchambers of the first sealed chamber 138 to be optimized for various areas of the foot in terms of geometry and pressure. For example, the subchambers of the first sealed chamber 138 can be customized in terms of quantity, size, position, and fluid pressure for a foot map of pressure loads for a specific wearer, or for an overall average of wearers of footwear of a specific size. Alternatively, the subchambers of the first sealed chamber 138 can be fluidly connected by channels. Figures 3 to 6 The first sealed chamber 138 shown in the cross-section of FIG. 1 is a single sub-chamber among the plurality of sub-chambers. Figures 3 to 6 All portions of the individual subchambers of the first sealed chamber 138 shown in FIG. 1 are in fluid communication.

[0051] The third sealed chamber 141 is also arranged in separate subchambers that are not in fluid communication with each other or with the first sealed chamber 138 or the second sealed chamber 140, similarly allowing the separate, discrete subchambers of the third sealed chamber 141 to be optimized for multiple areas of the foot 16. Alternatively, the subchambers of the third sealed chamber 141 may be fluidly connected by channels. Figures 3 to 6 The third sealed chamber 141 shown in FIG. 1 is a single subchamber of the subchambers, wherein all portions of the single subchamber of the third sealed chamber 141 are shown as being in fluid communication. The second sealed chamber 140 is a single large chamber surrounding all discrete pods of the first sealed chamber 138 and the third sealed chamber 141, as described.

[0052] The placement of the bonding portion 142 can be selected to adjust (i.e., control) the flexibility of the midsole 118. The flexibility (e.g., bending stiffness) of the midsole 118 at any given location depends at least in part on its height at that location. In the midsole 118, the relative filling pressures are such that the peak height of the second sealed chamber 140 is substantially equal to the peak heights of the stacked first and third sealed chambers 138, 141. This helps provide a relatively flat outer surface 130 facing the foot so that the midsole 118 can have a uniform feel to the foot. The height of the midsole 118 at any given location depends on the width (e.g., bending stiffness) of the chambers 138, 140, 141. Figures 3 to 6 140, 141) and the overlap between the sealed chambers (i.e., the portion where all three sealed chambers 138, 140, 141 are stacked vertically). These features depend on the placement and width of the joint 142. The joint 142 can be shaped and positioned to provide an area of ​​relatively reduced bending stiffness (and therefore increased flexibility) when desired.

[0053] refer to Figure 3 , the first polymer sheet 132 and the second polymer sheet 134 are bonded to each other at the bonding portion 147 along the outer peripheral portion 148 of the lower side 150 of the second sealed chamber 140, so that the first sealed chamber 138 is located below the second sealed chamber 140 only inside the outer peripheral portion 148 of the lower side 150 of the second sealed chamber 140. Similarly, the third polymer sheet 136 and the fourth polymer sheet 137 are bonded to each other at the bonding portion 151 along the outer peripheral portion 153 of the top side 155 of the second sealed chamber 140, so that the third sealed chamber 141 is superimposed on the second sealed chamber 140 only inside the outer peripheral portion 153 of the top side 155 of the second sealed chamber 140.

[0054] The joints 147, 151 at the outer peripheral portions 148, 153 at both the lower side 150 and the top side 155 form a double-piece thickness above and below the peripheral flange 146 having a four-piece thickness along the entire outer perimeter 148, 153 of the midsole 118. The double-piece thickness at the outer peripheral portions 148, 153 reduces outward bulging of the midsole 118 under dynamic compressive loads and helps average the pressure within the second fluid chamber 140 under dynamic compressive loads.

[0055] Second polymer sheet 134 is also bonded to first polymer sheet 132 at lower bond 157, which is at the lower perimeter of second sealed chamber 140 at ground-facing exterior surface 128 of midsole 118 and inside bond 147 at the exterior perimeter. Third polymer sheet 136 is bonded to fourth polymer sheet 137 at upper bond 159, which is at the upper perimeter of third sealed chamber 141 at foot-facing exterior surface 130 of midsole 118 and inside bond 151. As shown in FIG. Figure 3 As is apparent in the cross-sectional view of FIG. 1 , the second polymer sheet 134 and the third polymer sheet 136 tie the first polymer sheet 132 to the fourth polymer sheet 137 via the joint 142 between the upper joint 157 and the lower joint 159 and between the joints 147, 151 and the joints 157, 159. The selection of the shapes, sizes and positions of the plurality of tie joints 142, 147, 151, 157, 159 of the midsole (such as the midsole 118) enables the desired contoured outer surface of the final midsole to be achieved. Prior to being joined at the joint 142, at the flange 146 and at the joint 147 discussed below, the polymer sheets 132, 134, 136 and 137 are stacked, flat sheets. The solder mask material can be inkjet printed at all selected locations on the sheet where no joint is desired. For example, in a four-piece embodiment of midsole 118, solder mask material may be printed on both sides of second polymer sheet 134 and third polymer sheet 136 and / or on the upper surface of first polymer sheet 132, the upper surface of second polymer sheet 134, and the upper surface of third polymer sheet 136. The stacked, flat polymer sheets are then heat pressed to create a bond between adjacent sheets on the surfaces of all adjacent sheets except where the solder mask material is applied. No radio frequency welding is required.

[0056] Prior to bonding, polymer sheets 132, 134, 136, 137 are stacked, flat sheets. Once bonded, polymer sheets 132, 134, 136, 137 remain flat and only assume a contoured shape when chambers 138, 140, 141 are inflated and then sealed. In the illustrated embodiment, polymer sheets 132, 134, 136, and 137 are not thermoformed. Thus, if the inflation gas is removed, and assuming no other components are disposed in the chambers and the polymer sheets have not yet been bonded to other components (such as outsole 120), polymer sheets 132, 134, 136, and 137 will return to their initial, flat state.

[0057] The second sealed chamber 140 is directly superimposed only on the first portion 161 of the first sealed chamber 138. The first portion 161 is a portion that is not directly below the joint 142 and is Figure 2This is best shown between the line representing the junction 142 and the line representing the outer perimeter 144 of each discrete first chamber 138 . Figure 2 The area defined by the shape of each discrete first chamber 138 in FIG. 1 also indicates the location of the relatively thick portion 164 of the outsole 120 provided with the lugs 160, 162. The third sealed chamber 141 is directly superimposed on only the remaining portion 163 of the first sealed chamber 138. The remaining portion 163 is the portion directly below each of the plurality of discrete joints 142. These portions 161, 163 are also Figure 3 Indicated in FIG. 1 , the first portion 161 of the outer portion of the vertical dashed line 152 is formed from the outer periphery 144 (see FIG. 144 ) of the corresponding joint 142 thereon. Figure 2 ) extends downward and the remaining portion 163 is inside the dotted line 152.

[0058] Using this arrangement of the sealed chambers 138, 140, 141, the first buffer layer 122 absorbs dynamic compression loads in series with the second buffer layer 124 and the third buffer layer 126 at the first portion 161 of the first sealed chamber 138, and the first buffer layer 122 absorbs dynamic compression loads in parallel with the second buffer layer 124 and in series with the third buffer layer 126 at the remaining portion 163 of the first sealed chamber 138.

[0059] As described, second cushioning layer 124 is at least partially disposed in series with first cushioning layer 122 relative to dynamic compressive loads FL, GL applied to midsole 118. More specifically, first cushioning layer 122 and second cushioning layer 124 are in series relative to loads FL, GL at portion 161. Third cushioning layer 126 is also in series with second cushioning layer 124, wherein third cushioning layer 126 falls on portion 161. Thus, all three cushioning layers 122, 124, 126 are in series at portion 161. Third cushioning layer 126 is directly in series with first cushioning layer 122 relative to dynamic compressive loads FL, GL at portion 163.

[0060] The outsole 120 is secured to the outer surface 128 of the midsole 118 that faces the ground. In the illustrated embodiment, the outsole 120 extends from the medial edge 121 (also referred to as the medial end) of the midsole 118 to the lateral edge 123 (also referred to as the lateral end) (i.e., from the flange 146 at the medial side to the flange 146 at the lateral side). The outsole 120 may also extend from front to back under the entire midsole 118 as one piece, or the outsole 120 may be a plurality of separate pieces. A relatively thick portion 164 of the outsole 120 that is directly below the first sealed chamber 138 has lugs 160, 162. In the illustrated embodiment, a relatively thin portion 165 of the outsole 120 that is directly below the second sealed chamber 140 does not have lugs. As used herein, "relatively thick" and "relatively thin" are used in comparison to one another and do not represent any particular thickness magnitude. The thickness of relatively thick portion 164 may include the thickness of lug 160 and the thickness of the base of the outsole from which lugs 160, 162 protrude. Central lug 160 is substantially centered below first containment chamber 138 at the domed portion of ground-facing outer surface 128 of first polymer sheet 132 and contacts ground surface G even when sole structure 112 is only under steady-state load or unloaded.

[0061] The outsole 120 further includes one or more lateral lugs 162 that surround the central lug 160 and are disposed closer to the second sealed chamber 140 of the dome-shaped ground-facing outer surface 128 and / or are shorter than the central lug 160 so that when the sole structure 112 is unloaded or is simply not large enough to cause the first sealed chamber 138 to compress to Figure 4 When under steady-state load or dynamic compressive load in the first compression stage I, these side lugs 162 do not contact the ground surface G. Figure 3 , the lower surfaces of the lugs 160, 162 generally follow the contour of the arcuate shape of the ground-facing outer surface 128 below the first chamber 138. As in the illustrated embodiment, the lugs 160, 162 may be an integral part of the outsole 120. In alternative embodiments, either or both of the central lug 160 and the side lugs 162 may not be integrally formed with the outsole 120, but may instead be secured to the outsole 120 such that the outsole 120 with the lugs 160, 162 serves as a unitary component.

[0062] When the sole structure 112 is unloaded, or is only under a first load (such as a load that is not large enough to cause the first sealing chamber 138 to be compressed to Figure 4Under the steady-state load or dynamic compressive load of the first compression stage I of the shoe, a portion 165 of the outsole 120 directly below the second sealed chamber 140 at the ground-facing outer surface 128 does not contact the ground surface G. In other words, the relatively thin portion 165 does not form part of the ground contacting surface of the outsole 120 under the first load. The portion 165 may have no lugs, may have other tread elements, such as tread elements in a herringbone orientation, or may have a smooth surface without a tread design or lugs.

[0063] For each discrete pod of the first sealed chamber 138, the total width W3 of all the central lugs 160 at the ground contacting surface G is less than the width W4 of the ground-facing outer surface 128 of the first polymer sheet 132 at the pod, as shown in FIG. Figure 3160 , 162. Because the central lug 160 rests on the ground surface G and is not as wide as the ground-facing outer surface 128 of the overlying corresponding portion of the first cushioning layer 122 disposed directly thereon, the reaction load (ground load GL) to the dynamic compressive load on the midsole 118 is initially applied through the central lug 160 toward the center of the dome-shaped outer surface 128 of the first polymer sheet 132, where the maximum achievable displacement of the first sealed chamber 138 exists. Because the portion of the outsole 120 having the lugs 160, 162 is not as wide as the portion of the ground-facing outer surface 128 to which they are attached, the first sealed chamber 138 is compressed around the portion 164 having the lugs 160, 162. In addition, the portion 164 is nested between portions of the second sealed chamber 140 at a higher pressure, increasing the force required to move the midsole 118 laterally while the nested portion of the outsole 120 is held in position against the ground by the surrounding second sealed chamber 140. The midsole 118 and outsole 120 are thus cooperatively configured to interact to increase traction and lateral stability during compression, such as during lateral cutting motions in basketball. In other words, under a first compressive load, the ground-facing outer surface 128 of the midsole 118 is domed beneath the first cushioning layer 122, such that the central lug 160 is lower than the lateral lugs 162, and under a second compressive load greater than the first load, the first cushioning layer 122 compresses, moving the lateral lugs 162 flush with the central lugs 160, thereby increasing the ground contact area of ​​the outsole 120. Thus, under a first compressive load, such as a load for a stationary wearer within an expected weight range, only the relatively thick portion 164 (and more specifically, the lugs 160 thereof) forms a ground contacting surface, and under a second compressive load greater than the first compressive load, the first sealed chamber 138 compresses such that both the relatively thick portion 164 and the relatively thin portion 165 form a ground contacting surface. Furthermore, even relatively thick portion 164 has a larger contact area with the ground surface under the larger second load because lateral lugs 162 now also form part of the ground contact surface. Under the first compressive load, thicker portion 164 of outsole 120 beneath first cushioning layer 122 protrudes further from midsole 118 than thinner portion 165 of outsole 120 beneath second cushioning layer 124.

[0064] In the embodiment shown, the material of the outsole 120 has a fourth stiffness K4 greater than the first stiffness K1 of the first buffer layer 122, and may be more rigid or less rigid than either or both of the second stiffness K2 of the second buffer layer 124 and the third stiffness K3 of the third buffer layer 126. For example, the outsole 120 may be a polymer foam, such as an injected foam. In the embodiment shown, the fourth stiffness K4 is greater than the first stiffness K1 and the third stiffness K3, and less than the second stiffness K1.

[0065] refer to Figures 3 to 6 , assuming that the first stiffness K1 of the first cushioning layer 122 is less than the second stiffness K2 of the second cushioning layer 124, and the third stiffness K3 is greater than the first stiffness K1 and less than the second stiffness K2, then the stages of absorption of the dynamic compression loads FL, GL represented by the footbed load FL and the reaction ground load GL are schematically depicted. When the sole structure 112 is initially subjected to the dynamic compression loads FL, GL, the first cushioning layer 122 with the smallest stiffness is compressed first, which both changes the shape of the first sealed chamber 138 and compresses the gas in the first sealed chamber 138, so that the total volume of the first sealed chamber 138 is Figure 4 In relative to Figure 3 The unloaded state shown in FIG. 1 is reduced (which represents the first compression stage). The compression (if any) of the second sealed chamber 140, the third sealed chamber 141 and the outsole 120 in the first compression stage I is minimal. Figure 4 In the first compression stage I shown in FIG, the compression of the first sealed chamber 138 causes the domed surface to become straight or inverted, resulting in the lateral lugs 162 now forming part of the ground contact surface over which the ground load GL is distributed, thereby increasing traction and stability. A relatively thin portion 165 of the outsole 120 directly below the second sealed chamber 140 also contacts the ground surface G and forms part of the ground contact surface in the first compression stage I. Therefore, the ground contact surface of the sole structure 112 is larger in the first compression stage I than in the unloaded state, thereby increasing the traction and stability of the outsole 120. The midsole 118 has an effective stiffness during the first compression stage I, which depends on the substantially linear first stiffness K1 and can be determined by Figure 7 The portion 102 of the stiffness curve 100 represents the absorption of dynamic compressive loads by the first cushioning layer 122 having the first stiffness K1.

[0066] exist Figure 5In the second compression stage II shown in FIG. 1 , the third cushioning layer 126 begins to compress by the compression of the gas in the third sealed chamber 141, as indicated by the smaller volume of the third sealed chamber 141. Assuming that the first cushioning layer 122 has not yet reached its maximum compression under the dynamic compression load, the compression of the first sealed chamber 138 of the first cushioning layer 122 can continue in series with the compression of the third cushioning layer 126 in the second compression stage II. The midsole 118 has an effective stiffness during the second compression stage II that depends on the third stiffness K3 and, possibly to a lesser extent, on the first stiffness K1, and is determined by Figure 7 Portion 104 of the stiffness curve 100 is represented by Portion 104 of the curve 100 represents the absorption of dynamic compressive loads by the third cushioning layer 126 .

[0067] exist Figure 6 In the third compression stage III shown in FIG. 1 , the second buffer layer 124 begins to be compressed by the compression of the gas in the second sealed chamber 140, as shown by Figure 6 The ratio of the second sealed chamber 140 in Figure 5 Indicated by the small and medium volume. If the compression of the first sealed chamber 138 has not yet reached its maximum compression, the compression of the first portion 161 of the first sealed chamber 138 will continue in series with the second buffer layer 124, and the compression of the remaining portion 163 will continue in parallel with the second buffer layer 124. If the compression of the third buffer layer 126 has not yet reached its maximum value under the dynamic compression load in the second compression stage II, the compression of a portion of the third sealed chamber 141 between the lines 152 above each tie 142 will continue in parallel with the compression of the second buffer layer 124 and in series with the compression of the first buffer layer 122 (assuming that the compression of the first buffer layer 122 has not yet reached its maximum value under the dynamic compression load). Assuming that the compression of the first buffer layer 122 and the third buffer layer 126 has not yet reached their maximum values ​​under the dynamic compression load, the compression of the portion of the third sealed chamber 141 outside the lines 152 above each tie 142 will continue in series with the second buffer layer 124 and in series with the compression of the first buffer layer 122.

[0068] The stiffness K4 of the outsole 120 may be selected so that compression of the outsole 120 does not begin until after the third compression stage III. The third compression stage III has an effective stiffness that corresponds primarily to the relatively rigid second cushioning layer 124. The sealed chamber of compressible gas tends to quickly ramp up compression in a nonlinear manner after initial compression. The effective stiffness of the midsole 118 during the third compression stage III depends on the second stiffness K2 and, possibly to a lesser extent, on the first stiffness K1 and the third stiffness K3, and is determined by Figure 7The portion 106 of the stiffness curve 100 is shown in FIG. Figures 4 to 6 As indicated in FIG. 1 , the reduced overall height of the midsole 118 throughout the first, second, and third compression stages also reduces the tendency of the midsole 118 to tilt or tip over.

[0069] Reference again Figure 2 , it is apparent that the joint 142 between the second polymer sheet 134 and the third polymer sheet 136 is shaped, arranged and positioned to provide torsional stability while allowing the forefoot to bend in multiple directions. More specifically, in the forefoot region 113, the joint 142 is arranged so that the second containment chamber 140 forms a plurality of elongated segments, also referred to herein as tubular subchambers, which extend generally transversely through the midsole 118 from the medial edge 121 to the lateral edge 123. The central axis CL1 of the first elongated segment 140A of the second containment chamber 140 extends substantially or completely from the medial edge 121 to the lateral edge 123, thereby establishing a first bending axis FL1 about which the midsole 118 bends in the forefoot region 113. The joint 142 is also arranged so that the central axis CL2 of the second elongated segment 140B of the second sealed chamber 140 extends substantially or completely from the medial edge 121 to the lateral edge 123, thereby establishing a second bending axis FL2, about which the midsole 118 bends in the forefoot area 113. The second bending axis FL2 extends forward from the medial edge 121 to the lateral edge 123. The bending axes FL1, FL2 are both arranged at respective acute angles A1, A2, which are measured from the portion of the longitudinal midline LM of the midsole 118 in front of the point P1 to the bending axes FL1, FL2. The first bending axis FL1 extends at an acute angle A1, and the second bending axis FL2 extends at an acute angle A2. In the illustrated embodiment, the acute angles A1 and A2 are 45 degrees. In other embodiments, the acute angles may range from 30 degrees to 60 degrees. The first elongated segment 140A and the second elongated segment 140B and the bending axes FL1, FL2 intersect at a point P1 along the longitudinal midline LM that serves as a pivot point. A plurality of V-shaped joints adjoin and define the elongated segments 140A, 140B (from above and at the lateral and medial sides). Thus, the first elongated segment 140A and the second elongated segment 140B form an X-shape in the forefoot region 113.

[0070] As reference Figures 3 to 6As shown and described, a relatively thin portion 165 of the outsole 120 is located directly below the second sealed chamber 140 at the outer surface 128 facing the ground, and the relatively thin portion 165 is arranged in the same pattern as the first elongated segment 140A and the second elongated segment 140B. In addition, the midsole 118 tends to bend using the bending axes FL1, FL2 of the uninterrupted elongated segments 140A, 140B as pivot axes. When the forefoot area 113 of the midsole 118 (with the outsole 120 fixed thereto) is placed on the ground G, the wearer can pivot toward the lateral side (i.e., the side between the lateral edge 123 and the longitudinal midline LM) by bending along the first bending axis FL1, or pivot toward the medial side (i.e., the side between the longitudinal midline LM and the medial edge 121) by bending along the bending axis FL2, in either case lifting the heel area 117.

[0071] A plurality of V-shaped junctions 142 in the heel region 117 adjoin tubular subchambers 140C, 140D (also referred to as first and second elongated members, respectively) with similarly angled bending axes FL3 and FL4 disposed at acute angles A3, A4 within a similar range of values ​​as angles A1 and A2. The bending axes FL3 and FL4 extend from the medial edge 121 to the lateral edge and intersect at point P2.

[0072] It is noteworthy that in the midsole region 115 of the midsole 118, the joint 142 is arranged so that each of the first sealed chamber 138, the second sealed chamber 140, and the third sealed chamber 141 substantially extends from the lateral edge 123 of the midsole 118 through the longitudinal centerline LM of the midsole to the medial edge 121 of the midsole, thereby providing torsional stiffness in the midsole region 115. The V-shaped joint in the midsole region 115 is adjacent to the elongated segment 140E. The second chamber 140 extends from the medial edge 121 to the lateral edge 123 without being interrupted by the tie 142, and the first chamber 138 and the third chamber 141 are stacked. The symmetrical distribution of the ties 142 with respect to the longitudinal midline LM defines a plurality of elongated segments of the second sealed chamber 140 in the midshoe region 115, which extend almost from the medial edge 121 to the lateral edge 123, thereby providing torsional rigidity (i.e., support and torsional stability in the midsole region 115). In other words, the midsole 118 does not encourage twisting of the midsole about the longitudinal midline LM in the midsole region 115.

[0073] also, Figure 2 The many closed shapes of the joint 142 in the figure extend substantially from the medial edge 121 to the width of the midsole 118 to the lateral edge 123. The portion of the outsole 120 having the lugs 160, 162 is located below the joint 142, such as Figure 3 , and is therefore arranged to have a substantially and constant transverse footprint during all phases of loading, resisting lateral movement of sole structure 112 when sole structure 112 is placed on the ground through a lateral stop (i.e., through laterally outward and downward forces) (such as in basketball).

[0074] Figure 8 Another embodiment of the midsole 218 is shown in plan view, showing the forefoot facing surface 130. Thus, Figure 8 The midsole 218 and Figure 2 The bottom surface of the midsole 118 is shown opposite the (top) surface. Fig. 9 is Figure 8 The midsole 218 has many of the same features as the midsole 118, and these features are referred to by the same reference numerals. Similar to the midsole 118, the midsole 218 includes four polymer sheets 132, 134, 136 and 137. The solder mask material is different from Figure 2 The pattern is applied to adjacent surfaces of polymer sheets 132, 134, 136 and 137. Like the midsole 118, a joint 142 is provided in the midsole 218 to establish bending axes FL1, FL2, FL3 and FL4. In addition, the joint 142 is provided in the midsole area 115 so that a portion of each of the first sealed chamber 138, the second sealed chamber 140 and the third sealed chamber 141 extends substantially from the lateral edge 123 of the midsole 218 through the longitudinal centerline LM of the midsole 218 to the medial edge 121 of the midsole 218, thereby providing torsional stiffness in the midsole area 115. The joint 142 in the midsole area 115 is arranged so that the second sealed chamber 140 includes an elongated segment (also referred to as a tubular subchamber) that extends substantially from the lateral edge 123 to the medial edge 121, thereby providing torsional stiffness in the midsole area 115.

[0075] Figure 8 A first filling port 145 is shown extending between the second polymer sheet 134 and the third polymer sheet 136 at the perimeter before sealing the perimeter flange 146. The filling port 145 can be used to fill the second sealed chamber 140, and then seal and trim. A second filling port 149 is shown, which can extend between the third polymer sheet 136 and the fourth polymer sheet 137 and / or between the first polymer sheet 132 and the second polymer sheet 134, and is used to fill either or both of the stacked first sealed chamber 138 and the third sealed chamber 141, and then seal and trim.

[0076] refer to Fig. 9 , midsole 218 is shown in an unloaded state. Midsole 218 is loaded in a graded manner as described with respect to midsole 118. Figure 1 and Figures 3 to 6 The outsole of the shoe is 120 Fig. 9 Not shown, but with Figure 3 The midsole 218 is fixed to the ground-facing outer surface 128 in the same manner as in the embodiment of the present invention. The midsole 218 has a height H1 at the stacked first sealed chamber 138 and the third sealed chamber 141, except at the outermost periphery where the second polymer sheet 134 and the third polymer sheet 136 in the middle fasten the first polymer sheet 132 and the fourth polymer sheet 137 to each other. The height H1 is determined by selecting the width of the joint 142 and the joints 151, 157, which in turn determine the width W1 of the first sealed chamber 138 and the third sealed chamber 141 and the width W2 of the second chamber 140. In a non-limiting example, if the width W1 is 10 mm, the width W2 is 11 mm, and the width W3 is 3.5 mm, the height H1 can be 14 mm. In another example, if the width W1 is 12 mm, the width W2 is 13 mm, and the width W3 is 4.5 mm, the height H1 can be 19 mm.

[0077] In one non-limiting example, various embodiments of the midsole disclosed herein can provide a peak load in Newtons from about 110 N to about 320 N, where the peak load is defined as a displacement of 75 percent of the average height of the midsole. The compressive stiffness can be evaluated using the Standard Test Method for Impact Attenuation of Athletic Shoe Cushioning Systems and Materials ASTM F1614-99 (2006) or ASTM F1976, or other test methods can be used.

[0078] In one non-limiting example, when energy return is measured as a percentage of recovery from the initial drop height in an impact tester, or with a mechanical tester such as the one commercially available from Instron Corporation, Norwood Massachusetts,

[0013] Various embodiments of the midsole disclosed herein can provide from about 59% to about 82% energy return when measured with an ELECTROTECHNICAL INDUSTRIAL EQUIPMENT (ELECTROTECHNICAL INDUSTRIAL EQUIPMENT).

[0079] In order to assist and clarify the description of multiple embodiments, multiple terms are defined herein. Unless otherwise indicated, the following definitions apply throughout this specification (including claims). In addition, all references mentioned are incorporated herein in their entirety.

[0080] "Article(s) of footwear," "article(s) of footwear," and "footwear" may be considered both devices and articles of manufacture. Assembled, ready-to-wear articles of footwear (e.g., shoes, sandals, boots, etc.), as well as individual components of articles of footwear (such as midsoles, outsoles, upper components, etc.), prior to final assembly into a ready-to-wear article of footwear, are considered and may be referred to herein, alternatively, in the singular or plural, as "article(s) of footwear" or "footwear."

[0081] "A", "an", "the", "at least one" and "one or more" are used interchangeably to indicate that there is at least one of the items. There may be multiple such items unless the context clearly indicates otherwise. Unless otherwise indicated in view of the context, all numerical values ​​of parameters (e.g., amounts or conditions) in this specification (including the appended claims) should be understood to be modified by the term "about" in all cases, regardless of whether "about" actually appears before the numerical value. "Approximately" means that the stated numerical value allows some slight imprecision (somewhat close to the accuracy of the value; approximately or moderately close to the value; almost). If the imprecision provided by "about" is not understood in this ordinary sense in the art, then "about" as used herein at least indicates the variation that may be caused by the ordinary methods of measuring and using these parameters. As used in the specification and the appended claims, unless otherwise stated, a value is considered to be "approximately" equal to the stated value if it is not more than 5% greater than the stated value and not more than 5% less than the stated value. Additionally, the disclosure of a range should be understood to have specifically disclosed all values ​​and further subdivided ranges within that range.

[0082] The terms "comprising", "including" and "having" are inclusive and therefore specify the presence of stated features, steps, operations, elements or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements or components. The order of steps, processes and operations may be changed when possible, and additional or alternative steps may be adopted. As used in this specification, the term "or" includes any and all combinations of the relevant listed items. The term "any" is understood to include any possible combination of the referenced items, including "any" of the referenced items. The term "any" is understood to include any possible combination of the referenced claims of the appended claims, including "any" of the referenced claims.

[0083] For consistency and convenience, directional adjectives may be used throughout this detailed description corresponding to the illustrated embodiments. One of ordinary skill in the art will recognize that terms such as "above," "below," "upwardly," "downwardly," "top," "bottom," etc. may be used descriptively with respect to the drawings without representing a limitation on the scope of the invention as defined by the claims.

[0084] The term "longitudinal" refers to the direction in which a component extends a certain length. For example, the longitudinal direction of an article of footwear extends between the forefoot area and the heel area of ​​the article of footwear. The terms "forward" or "anterior" are used to refer to the general direction from the heel area toward the forefoot area, and the terms "rearward" or "posterior" are used to refer to the opposite direction, that is, the direction from the forefoot area toward the heel area. In some cases, a component can be identified by a longitudinal axis and the forward and rearward longitudinal directions along this axis. The longitudinal direction or axis may also be referred to as the front-rearward direction or axis.

[0085] The term "lateral" refers to the direction in which a component extends a certain width. For example, the lateral direction of an article of footwear extends between the lateral side and the medial side of the article of footwear. The lateral direction or axis may also be referred to as the lateral direction or axis or the mediolateral direction or axis.

[0086] The term "vertical" refers to a direction that is generally perpendicular to both the lateral direction and the longitudinal direction. For example, in the case where the sole structure is placed flat on a ground surface, the vertical direction may extend upward from the ground surface. It will be understood that each of these directional adjectives may be applied to a separate component of the sole structure. The term "upward" or "upwards" refers to a vertical direction pointing to the top of a component, which may include an instep, a fastening area, and / or a throat of an upper. The term "downward" or "downwards" refers to a vertical direction opposite to the upward direction, pointing to the bottom of the component, and may generally point to the bottom of the sole structure of an article of footwear.

[0087] The "interior" of an article of footwear (such as a shoe) refers to the portion of the space occupied by the wearer's foot when the article of footwear is worn. The "inside" of a component refers to the side or surface of the component that is oriented toward (or will be oriented toward) the interior of the component or article of footwear in the assembled article of footwear. The "outside" or "exterior" of a component refers to the side or surface of the component that is oriented away from (or will be oriented away from) the interior of the article of footwear in the assembled article of footwear. In some cases, other components may be between the medial side of the component and the interior in the assembled article of footwear. Similarly, other components may be between the lateral side of the component and the space outside the assembled article of footwear. In addition, the terms "inward" and "inwardly" refer to the direction toward the interior of a component or article of footwear (such as a shoe), and the terms "outward" and "outwardly" refer to the direction toward the exterior of a component or article of footwear (such as a shoe). In addition, the term "proximal" refers to a direction closer to the center of the footwear component or closer to the foot when the foot is inserted into the footwear article when the footwear article is worn by the user. Similarly, the term "distal" refers to a relative position further away from the center of the footwear component or further away from the foot when the foot is inserted into the footwear article when the footwear article is worn by the user. Therefore, the terms proximal and distal can be understood to provide generally opposite terms to describe relative spatial positions.

[0088] Although various embodiments have been described, this description is intended to be exemplary rather than restrictive, and it will be apparent to those of ordinary skill in the art that more embodiments and implementations within the scope of the embodiments are possible. Any feature of any embodiment may be used in combination or in place of any other feature or element in any other embodiment, unless specifically limited. Therefore, the embodiments are not limited except in accordance with the appended claims and their equivalents. In addition, various modifications and changes may be made within the scope of the appended claims.

[0089] Although several modes for carrying out many aspects of the present teachings have been described in detail, those familiar with the art to which these teachings relate will recognize multiple alternative aspects for practicing the present teachings within the scope of the appended claims. It is intended that all content contained in the above description or shown in the accompanying drawings should be interpreted as illustrative and exemplary of the entire range of alternative embodiments that will be recognized by ordinary technicians, which are implied by the included content, structurally and / or functionally equivalent to the included content, or otherwise become obvious based on the included content, and are not limited to only those explicitly depicted and / or described embodiments.

Claims

1. A sole structure for an article of footwear, comprising: A midsole having four stacked polymer sheets, including a first polymer sheet, a second polymer sheet, a third polymer sheet, and a fourth polymer sheet, the four stacked polymer sheets being bonded to each other to define a first sealed chamber defined by the first polymer sheet and the second polymer sheet, a second sealed chamber defined by the second polymer sheet and the third polymer sheet, and a third sealed chamber defined by the third polymer sheet and the fourth polymer sheet, each of the first sealed chamber, the second sealed chamber, and the third sealed chamber being isolated from each other sealed chamber to retain gas; wherein the second polymer sheet and the third polymer sheet are bonded to each other at a bonding portion between the first sealed chamber and the third sealed chamber, at least some of the bonding portions have an outer periphery with a closed shape, the second sealed chamber abuts the outer periphery, and the third sealed chamber is stacked above the first sealed chamber at the bonding portion; wherein the first sealed chamber and the second sealed chamber are disposed adjacent to a ground-facing surface of the midsole; wherein the first sealed chamber comprises discrete sub-chambers that are not in fluid communication with each other; In which, the first sealed chamber has a first stiffness, the second sealed chamber has a second stiffness greater than the first stiffness, the third sealed chamber has a third stiffness, and the compressive load on the sole structure is absorbed by the first sealed chamber, the second sealed chamber and the third sealed chamber in sequence according to the relative sizes of the first stiffness, the second stiffness and the third stiffness.

2. The sole structure according to claim 1, wherein: At least some of the discrete subchambers of the first sealed chamber are not in fluid communication with each other and each have a customized pressure.

3. The sole structure according to claim 2, wherein: The third sealed chamber includes discrete sub-chambers that are not in fluid communication with each other.

4. The sole structure according to claim 3, wherein: The second sealed chamber is a single chamber surrounding all discrete sub-chambers of the first sealed chamber and the second sealed chamber.

5. The sole structure according to claim 3, wherein: The third sealed chamber includes a plurality of discrete sub-chambers in fluid communication with each other via channels.

6. The sole structure according to claim 3, wherein: The filling pressures of the first sealed chamber, the second sealed chamber, and the third sealed chamber are such that the peak height of the second sealed chamber is substantially equal to the peak height of the stacked first sealed chamber and the third sealed chamber.

7. The sole structure according to claim 1, wherein: The third sealed chamber is completely displaced from the outer surface facing the ground by the first sealed chamber and the second sealed chamber; and The second sealed chamber and the third sealed chamber are arranged to define an outer surface of the midsole facing the foot.

8. The sole structure according to claim 1, wherein: The first polymer sheet and the second polymer sheet are bonded to each other at a bonding portion along an outer peripheral portion of a lower side of the second sealed chamber so that the first sealed chamber is located below the second sealed chamber only inside the outer peripheral portion of a lower side of the second sealed chamber.

9. The sole structure according to claim 8, wherein: The third polymer sheet and the fourth polymer sheet are bonded to each other at a bonding portion along the outer peripheral portion of the top side of the second sealed chamber so that the third sealed chamber is located above the second sealed chamber only inside the outer peripheral portion of the top side of the second sealed chamber.

10. The sole structure according to claim 9, wherein: A joint portion along an outer peripheral portion of a lower side of the second sealed chamber and a joint portion along an outer peripheral portion of a top side of the second sealed chamber have a thickness of two sheets.

11. The sole structure according to claim 10, wherein: The midsole has a peripheral flange at the outer periphery of the midsole, and the joint of the outer peripheral portion along the lower side of the second sealing chamber and the joint of the outer peripheral portion along the top side of the second sealing chamber form a double-sheet thickness above and below the peripheral flange along the entire outer periphery of the midsole, and the peripheral flange includes each of the first polymer sheet, the second polymer sheet, the third polymer sheet and the fourth polymer sheet, so that the peripheral flange has a thickness of four sheets.

12. The sole structure according to claim 1, wherein: The second sealed chamber is located only directly above the first portion of the first sealed chamber; and The third sealed chamber is located only directly above the remaining portion of the first sealed chamber, so that the first sealed chamber absorbs the compressive load on the sole midsole in series with the second sealed chamber at the first portion of the first sealed chamber, and the first sealed chamber absorbs the compressive load in parallel with the second sealed chamber and in series with the third sealed chamber at the remaining portion of the first sealed chamber.

13. The sole structure according to claim 1, wherein: The second containment chamber includes a plurality of elongated segments, each elongated segment extending lengthwise across the longitudinal centerline of the midsole at a respective acute angle relative to the longitudinal centerline.

14. The sole structure according to claim 13, wherein: The elongated segment includes a first elongated segment and a second elongated segment, wherein the first elongated segment is angled forward in a direction from the outer edge of the midsole to the inner edge of the midsole, and the second elongated segment is angled forward in a direction from the inner edge to the outer edge and intersects with the first elongated segment, and the first elongated segment and the second elongated segment establish a bending axis around which the midsole bends.

15. The sole structure according to claim 14, wherein: The first elongated segment and the second elongated segment together define an X-shape at a forefoot region of the midsole.

16. The sole structure according to claim 14, wherein: The first elongated segment and the second elongated segment together define an X-shape in a heel region of the midsole.

17. The sole structure according to claim 15, wherein: The joint between the second polymer sheet and the third polymer sheet includes a plurality of V-shaped joints in the forefoot area adjacent to the first elongated segment and the second elongated segment.

18. The sole structure according to claim 1, wherein: At least some of the discrete subchambers of the first sealed chamber are tubular and extend lengthwise at least partially transversely through the midsole at a ground-facing outer surface.

19. The sole structure of claim 1 , comprising an outsole secured to the ground-facing surface of the midsole; in, The outsole has a relatively thick portion below the first sealing chamber and a relatively thin portion below the second sealing chamber, so that under a first compression load, only the relatively thick portion forms a ground contact surface, and under a second compression load greater than the first compression load, the first sealing chamber is compressed so that both the relatively thick portion and the relatively thin portion form a ground contact surface.

20. The sole structure according to claim 19, wherein: The outsole includes a lug disposed directly below the first sealed chamber; and The lug is narrower than a corresponding portion of the first seal chamber disposed directly above the lug such that the first seal chamber compresses around the lug under the second compressive load.

21. The sole structure according to claim 19, wherein: The first and second containment chambers include a plurality of tubular subchambers extending lengthwise at least partially transversely through the midsole at the ground-facing surface.

22. The sole structure according to claim 21, wherein: a first tubular subchamber of the tubular subchambers of the second sealed chamber extending from a medial edge of the midsole to a lateral edge of the midsole at a first acute angle relative to a longitudinal centerline of the midsole without being interrupted by the first sealed chamber and the third sealed chamber, thereby establishing a first bending axis about which the midsole bends; a second tubular subchamber of the tubular subchambers of the second containment chamber extending from a medial edge of the midsole to a lateral edge of the midsole at a second acute angle relative to a longitudinal centerline of the midsole without being interrupted by the first containment chamber and the third containment chamber, thereby establishing a second bending axis about which the midsole bends; The first bending axis and the second bending axis intersect in a forefoot region of the midsole.

23. The sole structure according to any one of claims 21-22, wherein: The tubular subchamber extends substantially from a lateral edge of the midsole through a longitudinal centerline of the midsole to a medial edge of the midsole in a midfoot region of the midsole to provide torsional stiffness in the midfoot region.

24. The sole structure according to claim 1, wherein: The four stacked polymer sheets are bonded to each other at a peripheral flange and define a first buffer layer having the first sealed chamber, a second buffer layer having the second sealed chamber, and a third buffer layer having the third sealed chamber; wherein the bonding between adjacent polymer sheets of the four stacked polymer sheets is arranged such that the second buffer layer abuts the first buffer layer and the third buffer layer, and the second sealed chamber of the second buffer layer abuts the peripheral flange; wherein the perimeter flange extends from a forefoot region of the midsole to a heel region of the midsole along both a medial side of the midsole and a lateral side of the midsole and establishes a perimeter of the midsole at both the medial side of the midsole and the lateral side of the midsole; The second sealed chamber is adjacent to the peripheral flange along the inner and outer sides and dynamic compression loads are absorbed in sequence according to the relative magnitudes of the first stiffness, the second stiffness and the third stiffness from the smallest stiffness to the largest stiffness.

25. The sole structure according to claim 24, wherein: The second sealed chamber is a single chamber surrounding the first sealed chamber and the second sealed chamber.

26. The sole structure according to any one of claims 24 or 25, wherein: The second containment chamber adjoins the peripheral flange along a medial side of the midsole from the forefoot region to the heel region and along a lateral side of the midsole from the forefoot region to the heel region.

27. The sole structure according to any one of claims 24 or 25, wherein: The first polymer sheet and the second polymer sheet are bonded to each other at a bonding portion along an outer peripheral portion of a lower side of the second sealed chamber so that the first sealed chamber is located below the second sealed chamber only inside the outer peripheral portion of a lower side of the second sealed chamber.

28. The sole structure according to claim 27, wherein: The third polymer sheet and the fourth polymer sheet are bonded to each other at a bonding portion along the outer peripheral portion of the top side of the second sealed chamber so that the third sealed chamber is located above the second sealed chamber only inside the outer peripheral portion of the top side of the second sealed chamber.

29. The sole structure according to claim 28, wherein: A joint portion along an outer peripheral portion of a lower side of the second sealed chamber and a joint portion along an outer peripheral portion of a top side of the second sealed chamber have a thickness of two sheets.

30. The sole structure according to claim 29, wherein: The peripheral flange is outside an outer peripheral portion of a top side of the second sealed chamber and outside an outer peripheral portion of a lower side of the second sealed chamber.

31. The sole structure according to any one of claims 24 or 25, wherein: The first cushioning layer and the second cushioning layer are disposed adjacent a ground-facing surface of the midsole; and Wherein, the third cushioning layer is displaced from the ground-facing surface of the midsole through the first cushioning layer and the second cushioning layer.

32. The sole structure according to claim 31, wherein: The second cushioning layer and the third cushioning layer define a foot-facing surface of the midsole; and Wherein, the first cushioning layer is displaced from the foot-facing surface of the midsole by the second cushioning layer and the third cushioning layer.

33. The sole structure according to any one of claims 24 or 25, wherein: The second sealed chamber includes a plurality of tubular subchambers in fluid communication with each other, each subchamber extending laterally across the midsole from the inner side of the midsole to the outer side of the midsole.

34. The sole structure according to claim 33, wherein: The second sealed chamber is a single chamber surrounding all discrete sub-chambers of the first sealed chamber and the plurality of tubular sub-chambers of the second sealed chamber.

35. The sole structure according to claim 26, wherein: The first sealed chamber and the second sealed chamber are disposed adjacent to a ground-facing outer surface of the midsole; and wherein the first sealed chamber comprises a plurality of tubular sub-chambers.

36. The sole structure according to any one of claims 24 or 25, wherein: The first cushioning layer and the second cushioning layer are adjacent to a ground-facing surface of the midsole, and further comprising: an outer sole secured to said ground-facing surface; and wherein the outer sole has a relatively thick portion below the first sealing chamber and a relatively thin portion below the second sealing chamber, so that under a first compression load, only the relatively thick portion forms a ground contact surface, and under a second compression load greater than the first compression load, the first sealing chamber is compressed so that both the relatively thick portion and the relatively thin portion form a ground contact surface.

37. The sole structure according to any one of claims 24 or 25, wherein: the second buffer layer directly covers only a first portion of the first buffer layer; and In which, the third buffer layer directly covers only the remaining portion of the first buffer layer, so that the first buffer layer absorbs dynamic compression load in series with the second buffer layer at the first portion of the first buffer layer, and the first buffer layer absorbs compression load in parallel with the second buffer layer and in series with the third buffer layer at the remaining portion of the first buffer layer.

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