Footwear bladder system

Abstract

A sole structure for an article of footwear includes a midsole that includes a bladder system having a forefoot region, a midfoot region, and a heel region. The bladder system defines a first sealed chamber holding fluid as a first cushioning layer, the first sealed chamber extending over the forefoot region, the midfoot region, and the heel region. The bladder system also defines a plurality of discrete sealed chambers holding fluid isolated from one another, each of the plurality of discrete chambers disposed on a side of the first sealed chamber and fluidically isolated from the first sealed chamber.

Description

[0001] This application is a divisional application of the application for patent application serial number 201980077084.X, filed on November 1, 2019, entitled “FOOTWEAR BLADDER SYSTEM”.

[0002] Cross Reference to Related Applications

[0003] This application claims priority to U.S. Provisional Application Serial No. 62 / 769,852, filed November 20, 2018, the contents of which are incorporated by reference in their entirety. TECHNICAL FIELD

[0004] The present invention relates generally to a midsole for a footwear article, and more particularly to a midsole having a bladder system. BACKGROUND

[0005] Footwear articles generally include a sole structure configured to be located beneath a wearer’s foot to space the foot from the ground. Sole structures in athletic footwear are often configured to provide cushioning, motion control, and / or resiliency. SUMMARY

[0006] The present invention relates generally to a midsole for a sole structure, and more particularly to a midsole having a bladder system that provides a single fluid-filled chamber at a foot-facing surface and a plurality of discrete fluid-filled chambers at a ground-facing surface. This enables the fluid-filled chamber at the foot-facing surface to be tuned to achieve a particular uniform feel across the forefoot, midfoot, and heel regions, while the underlying discrete fluid-filled chambers can each be tuned relative to the different loads experienced at their respective locations. The bladder system can include four stacked polymer sheets. Bladders including stacked polymer sheets are generally easier to assemble and require less specialized tooling. For example, no thermoforming molds are required. Instead, the geometry of the bladder system is primarily due to the placement of a solder resist material between the stacked polymer sheets prior to heat pressing the sheets to one another. The placement of the solder resist material that bonds the sheets to one another controls the shape and geometry of the bladder system and its fluid chambers, as well as whether the fluid chambers are in communication with one another or isolated from one another, and the cushioning response of portions of the bladder system.

[0007] In one example, a sole structure for a footwear article includes a midsole including a bladder system having a forefoot region, a midfoot region, and a heel region. The bladder system can define a first sealed chamber holding fluid as a first cushioning layer, the first sealed chamber extending over the forefoot region, the midfoot region, and the heel region. The bladder system can also define a plurality of discrete sealed chambers holding fluid isolated from one another, each of the plurality of discrete chambers disposed on a side of the first sealed chamber and fluidically isolated from the first sealed chamber.

[0008] In one or more embodiments, only the first sealed chamber and none of the plurality of discrete chambers extend in each of the forefoot region, the midfoot region, and the heel region. However, by providing a full-length first sealed chamber at the foot-facing surface, a larger, relatively flat surface area is provided for attachment to an upper, while the shape and pressure of the areas discrete chambers at the ground-facing surface can be optimized for cushioning response.

[0009] In one or more configurations, the bladder system can define a foot-facing surface and a ground-facing surface. The first sealed chamber can be disposed between the foot-facing surface and the plurality of discrete chambers. The plurality of discrete chambers can be disposed between the ground-facing surface and the first sealed chamber.

[0010] In one aspect, the bladder system can include a plurality of stacked polymer sheets, including an upper sheet at least partially defining the foot-facing surface, a lower sheet at least partially defining the ground-facing surface, and a middle sheet disposed between the upper sheet and the lower sheet. The first sealed chamber can be enclosed by the upper sheet and the middle sheet. The bladder system can include additional middle sheets as described herein, such that the bladder system includes four stacked polymer sheets. The plurality of stacked polymer sheets can be joined together at a peripheral flange. For example, the plurality of stacked polymer sheets can collectively extend, each polymer sheet having an outer periphery at the peripheral flange.

[0011] In a further aspect, the upper sheet can be joined to the middle sheet at a plurality of point junctions spaced apart from one another in the forefoot region, the midfoot region, and the heel region, the first sealed chamber surrounding a perimeter of each of the point junctions, and the foot-facing surface having a plurality of dimples at the plurality of point junctions. In some embodiments, the first sealed chamber is the only fluid-filled chamber at the foot-facing surface.

[0012] In one or more embodiments, the bladder system can include a dome-shaped pod extending at the ground-facing surface, and the plurality of discrete chambers can include a peripheral heel chamber in the heel region, a central heel chamber in the heel region, a peripheral lateral forefoot chamber in the forefoot region, and a medial forefoot chamber in the forefoot region. The peripheral heel chamber, the central heel chamber, the peripheral lateral forefoot chamber in the forefoot region, and the medial forefoot chamber in the forefoot region can include a plurality of fluidly connected sub-chambers corresponding to the dome-shaped pod. In some embodiments, the peripheral heel chamber, the central heel chamber, the peripheral lateral forefoot chamber, and the medial forefoot chamber are the chambers corresponding to the dome-shaped pod at the ground-facing surface.

[0013] Isolation of the discrete sealed chambers at the ground-facing surface allows for different inflation pressures to achieve different cushion responses. In one or more configurations, the inflation pressure of the gas maintained in the peripheral lateral chamber can be greater than the inflation pressure of the gas maintained in the medial forefoot chamber. Further, the inflation pressure of the gas maintained in the peripheral lateral chamber can be greater than the inflation pressure of the gas maintained in the peripheral heel chamber, and greater than the inflation pressure of the gas maintained in the central heel chamber. In one example, the inflation pressure of the gas maintained in the peripheral lateral chamber can be greater than the inflation pressure of the gas maintained in the peripheral heel chamber, while the inflation pressure of the gas maintained in the peripheral heel chamber can be greater than the inflation pressure of the gas maintained in the central heel chamber, and the inflation pressure of the gas maintained in the central heel chamber can be greater than the inflation pressure of the gas maintained in the forefoot medial chamber. The first sealed chamber can have a greater or lesser inflation pressure than one or more underlying discrete sealed chambers. Some of the discrete chambers and / or the first sealed chamber can have the same inflation pressure, and at least one of the discrete chambers and / or the first sealed chamber can be at ambient pressure in an unloaded state.

[0014] In one implementation, the bladder system can include a plurality of stacked polymer sheets, including a first sheet at least partially defining the foot-facing surface, a second sheet bonded to the first sheet (the first sealed chamber is enclosed by the first and second sheets), a third sheet bonded to the second sheet, and a fourth sheet bonded to the third sheet and at least partially defining the ground-facing surface. At least one of the plurality of discrete chambers can be enclosed by the second and third sheets, and at least one of the plurality of discrete chambers can be enclosed by the third and fourth sheets. In some embodiments, the bladder system includes only these four polymer sheets, and does not include other stacked polymer sheets.

[0015] The bladder system can include a domed pod extending at the ground-facing surface. The domed pod can be part of the fourth (bottom) polymer sheet. At least one of the plurality of discrete chambers can include a plurality of fluidly connected sub-chambers, the fluidly connected sub-chambers corresponding to the domed pod. In other words, the shape of the fluidly connected sub-chambers results in the formation of the domed pod (e.g., a circular protrusion) at the ground-facing surface. Further, at least one of the plurality of discrete chambers can include an annular ring portion fluidly isolated from and surrounding one of the sub-chambers corresponding to the domed pod. The annular ring portion can be located at the lateral side of the forefoot region. In one example, one or more sub-chambers of the peripheral lateral chamber are enclosed by the annular ring portion of another of the discrete chambers.

[0016] The plurality of discrete chambers can include a peripheral heel chamber having an arcuate portion disposed posterior to the heel region, a lateral arm portion extending forward in the heel region along a lateral side of the bladder system from the arcuate portion, and a medial arm portion extending forward in the heel region along a medial side of the bladder system from the arcuate portion, wherein the medial arm portion is spaced apart from the lateral arm portion.

[0017] Further, the plurality of discrete chambers can include a central heel chamber disposed between the medial arm portion and the lateral arm portion of the peripheral heel chamber and forward of the arcuate portion of the peripheral heel chamber. The central heel chamber can include a plurality of fluidly connected sub-chambers corresponding to a plurality of dome-shaped pods extending at the ground-facing surface of the bladder system. The plurality of fluidly connected sub-chambers of the central heel chamber and their corresponding dome-shaped pods can be disposed in longitudinally extending rows between the lateral arm portion and the medial arm portion.

[0018] In one or more embodiments, the plurality of discrete chambers can include a peripheral lateral chamber extending along a lateral side of the bladder system in the forefoot region. The peripheral lateral chamber can be disposed entirely between a longitudinal midline of the bladder system and a lateral side of the bladder system. The bladder system can include dome-shaped pods extending at the ground-facing surface, and the peripheral lateral chamber can include a plurality of fluidly connected sub-chambers corresponding to a plurality of the dome-shaped pods arranged in longitudinally extending rows along the lateral side of the ground-facing surface in the forefoot region. One of the plurality of discrete chambers can include an annular ring portion fluidically isolated from and surrounding one of the sub-chambers of the peripheral lateral chamber. Further, the plurality of discrete chambers can include a medial forefoot chamber disposed along a medial side of the bladder system in the forefoot region and extending over the longitudinal midline.

[0019] The above-mentioned and other features and advantages of this teaching will be apparent from the following detailed description of a mode for embodying this teaching, when taken in connection with the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0020] The drawings described herein are for illustrative purposes only and are not meant to limit the scope of the disclosure. In the drawings:

[0021] Figure 1 is a top perspective view of the bladder system.

[0022] Figure 2 is a bottom perspective view of the bladder system of Figure 1

[0023] Figure 3 is a medial view of the bladder system of Figure 1

[0024] is a medial view of the bladder system of​Figure 4 is a cross-sectional view of the bladder system of Figure 1 taken along line 4-4 in Figure 1 .

[0025] Figure 5 is a cross-sectional view of the bladder system of Figure 1 taken along line 5-5 in Figure 1 . DETAILED DESCRIPTION

[0026] Referring to the drawings, wherein like reference numbers refer to like elements throughout the several views, Figure 1 A sole structure 10 for an article of footwear is shown. Only a portion of the sole structure 10 is shown. More specifically, a midsole 12 of the sole structure 10 is shown. The midsole 12 includes a bladder system 14. The bladder system 14 shown is referred to as a full-length bladder system because it includes a forefoot region 16, a midfoot region 18, and a heel region 20. The midfoot region 18 is located between the heel region 20 and the forefoot region 16. As understood by those skilled in the art, the forefoot region 16 is generally located under the toes and metatarsal-phalangeal joints of an overlying foot. The midfoot region 18 is generally located under the arch region of the foot. The heel region 20 is generally located under the calcaneus. The bladder system 14 has a medial side 22 that is generally shaped to follow the medial side of an overlying foot and a lateral side 24 that is generally shaped to follow the lateral side of an overlying foot.

[0027] Other components can be used in conjunction with the bladder system 14 to complete the midsole 12 and the sole structure 10. For example, in some embodiments, other components of the sole structure 10 can be secured to the bladder system 14. For example, an outsole or outsole component can be secured at a ground-facing surface, or a foam midsole layer can be secured at a ground-facing surface. Additionally or alternatively, a foam midsole layer can be secured at a foot-facing surface 31. For example, different foam midsole layers can be secured at the foot-facing surface 31 and at a ground-facing surface. Additionally, an upper can be secured to the bladder system 14 at the foot-facing surface 31 and / or at a lateral surface formed by the inflated top and bottom sheets at the outer periphery 28 of the bladder system 14.

[0028] The bladder system 14 includes four stacked polymer sheets joined together at a peripheral flange 26, as described herein. The peripheral flange 26 can extend completely around the outer periphery 28 of the bladder system 14, and the four stacked polymer sheets can collectively extend, each to the peripheral flange 26, and have the outer periphery 28 at the peripheral flange 26.

[0029] In Figure 1 only the first sheet 30 is visible. The first sheet 30 can also be referred to as an upper sheet. The upper sheet 30 includes and establishes the foot-facing surface 31 of the bladder system 14. Figure 4The four stacked panels are best shown, which show that the bladder system 14 also includes two intermediate panels, referred to as a second panel 32 and a third panel 34, and a fourth panel 36, referred to as a lower panel or bottom panel. The fourth panel 36 includes and establishes the ground-facing surface 38 of the bladder system 14. A first sealed chamber 40 is enclosed by the first panel 30 and the second panel 32. The first sealed chamber 40 holds fluid as a first cushioning layer. The first sealed chamber 40 extends over the forefoot region 16, the midfoot region 18, and the heel region 20. The first sealed chamber 40 is the only sealed chamber of the bladder system 14 that is disposed at and defines the foot-facing surface 31. Thus, a foot supported on the bladder system 14 has the first sealed chamber 40 under the broad portion of the foot in each of the forefoot region 16, the midfoot region 18, and the heel region 20. The inflation pressure of the first sealed chamber 40 significantly influences the wearer’s perception of the firmness of the bladder system 14 because the first sealed chamber 40 is closer to the foot than any other sealed chamber formed by the bladder system 14 and described herein.

[0030] The upper panel 30 is bonded to the second panel 32 in the forefoot region 16, the midfoot region 18, and the heel region 20 at a plurality of points of bonding 41 spaced apart from one another. The points of bonding 41 are shown as small circles, but can be other closed shapes, such as squares or triangles. The points of bonding 41 are uniformly spaced apart from one another in rows. The points of bonding 41 in adjacent rows can be offset from one another. In Figure 1 In particular, the uniformly spaced pattern of points of bonding 41 is somewhat obscured by slight waviness of the upper panel 30 caused by the various inflation pressures of the discrete chambers described herein below. However, the points of bonding 41 are formed in uniformly spaced circular areas that are not covered by the barrier ink pattern applied to the bottom surface of the upper panel 30 and the barrier ink pattern applied to the top surface of the second panel 32. The foot-facing surface 31 also has a plurality of dimples 43 at the plurality of points of bonding 41. Each point of bonding 41 causes the first panel 30 to be recessed toward the point of bonding 41, forming a dimple 43. In the second panel 32, a corresponding dimple is created around where it is constrained at the bonding 41. In Figure 1Only some of the pockets 43 and the point bonds 41 are indicated with reference numerals. The point bonds 41 serve to limit the total distance between the panels 30, 32, and thus the height of the first sealed chamber 40, when the first sealed chamber 40 is inflated. The first sealed chamber 40 surrounds each point bond 41 between the first panel 30 and the second panel 32, and is in communication around the point bonds 41. During a forward roll of the foot in which dynamic loads start in the heel region 20 and move forward, the gas in the first sealed chamber 40 is more easily moved from back to front, free to move around the point bonds 41 in the first sealed chamber 40. Thus, the cushioning response of the bladder system 14 is not only staged with respect to the bladder system 14 absorbing vertical impact forces through the sealed chambers working in stages as described herein, but also with respect to the forward roll of the foot from heel to toe.

[0031] Figure 4 and 5 A plurality of discrete chambers 42, 44, 46, 48, 49, and 50 are shown disposed on a first side 53 of the first sealed chamber 40, between the ground-facing surface 38 and the first sealed chamber 40. Thus, the first sealed chamber 40 is disposed between the foot-facing surface 31 and the plurality of discrete chambers 42, 44, 46, 48, 49, and 50. Referring to Figure 2 The plurality of discrete chambers 42, 44, 48, and 50 are enclosed between and bounded by the third panel 34 and the fourth panel 36. These chambers are fluidly isolated from one another by the bonds 68 of the third panel 34 to the fourth panel 36 that separate the chambers. Two additional discrete chambers 46 and 49 are disposed between the second panel 32 and the third panel 34. Chambers 46 and 49 are isolated from one another by the bonds 45 of the second panel 32 to the third panel 34.

[0032] The plurality of discrete sealed chambers 42, 44, 46, 48, 49, and 50 remain fluidly isolated from one another, and each is also fluidly isolated from the first sealed chamber 40. The plurality of discrete chambers includes a peripheral heel chamber 42 in the heel region 20, a central heel chamber 44 in the heel region 20, a peripheral lateral forefoot chamber 46 in the forefoot region 16, and a medial forefoot chamber 48 in the forefoot region 16. In addition, a discrete chamber 49 is located underneath the entire first sealed chamber 40, except where the peripheral lateral forefoot chamber 46 extends along the lateral side 24. The second panel 32 can be bonded to the third panel 34 at point bonds 45 similar to the point bonds 41. Chamber 49 surrounds the point bonds 45 and is in fluid communication around the point bonds 45.

[0033] Each of the discrete chambers 42, 44, 46, 48, and 50 is at least partially formed by the fourth panel 36, and thus at an inner surface of the fourth panel 36, and affects the shape of the ground-facing surface 38. The outer boundary of each of the discrete chambers 42, 44, 46, 48, and 50 is in the plane of the fourth panel 36. Figure 2The fluid isolation of each of the chambers 42, 44, 46, 48, and 50 is schematically indicated by dashed lines to show. Boundary A is the boundary of the peripheral heel chamber 42. Boundary B is the boundary of the central heel chamber 44. Boundary C is the boundary of the peripheral lateral chamber 46. Boundary D is the boundary of the medial forefoot chamber 48. The annular boundary E defines the annular ring portion of the discrete chamber 50. The annular ring portions can be in fluid communication with each other through connecting channels, or can be fluidly isolated from each other by the junction of the third panel 34 to the fourth panel 36 between the annular portions.

[0034] The first sealed chamber 40 is located Figure 2 below the entire area shown in the bottom perspective view of Figure 2 , including below the discrete chambers 42, 44, 46, 48, 49, and 50, and below each of the areas bounded by the dashed lines A, B, C, D, and E in Figure 2 (and above these same areas when the bladder system 14 is not inverted as in Figure 2 ). The first sealed chamber 40 is indicated by a reference line in only some areas in Figure 2 . Similarly, the discrete chamber 49 is located below the discrete chambers 42, 44, 48, and 49, and below each of the areas bounded by the dashed lines A, B, and D in Figure 2 (and above these same areas when the bladder system 14 is not inverted as in Figure 2 ), but is indicated by a reference line in only some areas in Figure 2 . Because the panels 30, 32, 34, and 36 can be transparent, some of the point junctions 41 are shown in

[0035] Due to the shape of the various sealed chambers and sub-chambers within the sealed chambers, the bladder system 14 has protruding dome pods 70 that extend at the surface 38 facing the ground. Each dome pod 70 is a portion of the fourth panel 36 (e.g., the bottom panel) at which it forms a dome protrusion. For example, the peripheral heel chamber 42, the central heel chamber 44, the peripheral lateral chamber 46 in the forefoot region 16, and the medial forefoot chamber in the forefoot region 16 can each include a plurality of fluidly connected sub-chambers that correspond to the dome pods.

[0036] The peripheral heel chamber 42 has an arcuate portion 60 disposed at the rear of the heel region 20, a lateral arm portion 64 extending forward in the heel region 20 along the lateral side 24 of the bladder system 14 from the arcuate portion 60, and a medial arm portion 62 extending forward in the heel region 20 along the medial side 22 of the bladder system 14 from the arcuate portion 60. The medial arm portion 62 is spaced apart from the lateral arm portion 64, and the central heel chamber 44 is disposed between the arm portions 62, 64, and forward of the arcuate portion 60 of the peripheral heel chamber 42.

[0037] The peripheral heel chamber 42 includes a plurality of fluidly connected subchambers 42A, 42B, 42C, 42D, 42E, 42F, and 42G. The subchamber 42A is in the arcuate portion 60, the subchambers 42B, 42C, and 42D are in the medial arm portion 62, and the subchambers 42E, 42F, and 42G are in the lateral arm portion 64. The junction 66 between the third panel 34 and the fourth panel 36 narrows the peripheral heel chamber 42, partially dividing it into subchambers. However, the junction 66 does not completely enclose the peripheral heel chamber 42 between adjacent subchambers, and all of the subchambers 42A, 42B, 42C, 42D, 42E, 42F, and 42G are in fluid communication with each other.

[0038] The central heel chamber 44 includes a plurality of fluidly connected subchambers 44A, 44B, and 44C, each corresponding to a domed pod 70 extending at the ground-facing surface 38 of the bladder system 14. The plurality of fluidly connected subchambers 44A, 44B, and 44C, and their corresponding domed pods 70, are disposed in a longitudinally extending row between the medial arm portion 62 and the lateral arm portion 64. The junction 68 between the third panel 34 and the fourth panel 36 separates the peripheral heel chamber 42 from the central heel chamber 44, and partially divides it into the subchambers 44A, 44B, and 44C. However, the junction 68 does not completely enclose the central heel chamber 44 between adjacent subchambers 44A, 44B, and 44C, and all of the subchambers 44A, 44B, and 44C are in fluid communication with each other. Some other areas of the third panel 34 joining to the fourth panel 36 are shown in Figure 2 FIG. 68, and can represent the same continuous junction 68 of the third panel 34 to the fourth panel 36 or a different junction 68.

[0039] The peripheral lateral chamber 46 extends along the lateral side 24 of the bladder system 14 in the forefoot region 16, and is disposed entirely between the longitudinal midline LM of the bladder system 14 and the lateral side 24 of the bladder system 14. The peripheral lateral chamber 46 includes a plurality of fluidly connected subchambers 46A, 46B, 46C, 46D, and 46E, corresponding to the domed pods 70 disposed in a longitudinally extending row along the lateral side 24 of the ground-facing surface 38 in the forefoot region 16. These subchambers 46A, 46B, 46C, 46D, and 46E are not divided by a junction, but are each disposed inside of and surrounded by a different one of the annular ring portions of the subchamber 50.

[0040] The medial forefoot chamber 48 is disposed along the medial side 22 of the bladder system 14 in the forefoot region 16 and extends on the longitudinal midline LM. The junction 68 between the third panel 34 and the fourth panel 36 partially divides the medial forefoot chamber 48 into sub-chambers 48A, 48B, 48C, 48D, 48E, 48F, 48G, 48H, 481, and 48K. The domed pods 70 correspond to the sub-chambers 48A, 48B, 48C, 48D, 48E, 48F, 48G, 48H, 48I, and 48K. However, the junction 68 does not completely enclose the medial forefoot chamber 48 between adjacent ones of the sub-chambers 48A, 48B, 48C, 48D, 48E, 48F, 48G, 48H, 48I, and 48K, and all of the sub-chambers 48A, 48B, 48C, 48D, 48E, 48F, 48G, 48H, 48I, and 48K are in fluid communication with each other.

[0041] As shown, there are six domed pods 70 at the peripheral heel chamber 42, three domed pods 70 at the central heel chamber 44, five domed pods 70 at the peripheral lateral chamber 46, and ten domed pods 70 at the medial forefoot chamber 48. As shown, the domed pods 70 are not all the same shape or size, and at least some of the domed pods 70 have different internal volumes. The different shapes and internal volumes of the domed pods 70 affect the cushioning provided to the foot portion above them during dynamic loading. Figure 3

[0042] The isolation of the discrete sealed chambers allows for different inflation pressures to achieve different cushioning responses. For example, the inflation pressure of the gas held in the peripheral lateral chamber 46 can be greater than the inflation pressure of the gas held in the medial forefoot chamber 48. Further, the inflation pressure of the gas held in the peripheral lateral chamber 46 can be greater than the inflation pressure of the gas held in the peripheral heel chamber 42, and greater than the inflation pressure of the gas held in the central heel chamber 44. In one example, the inflation pressure of the gas held in the peripheral lateral chamber 46 is greater than the inflation pressure of the gas held in the peripheral heel chamber 42, which is greater than the inflation pressure of the gas held in the central heel chamber 44, which is greater than the inflation pressure of the gas held in the medial forefoot chamber 48. The first sealed chamber 40 can have a greater or lesser inflation pressure than one or more of the underlying sealed chambers 42, 44, 46, 48, 49, and 50, and the sealed chamber 49 can have a greater or lesser inflation pressure than one or more of the other sealed chambers 40, 42, 44, 46, 48, and 50. In other examples, different relative inflation pressures can be provided. Some of the discrete chambers can have the same inflation pressure, and / or at least some of the discrete chambers can be at ambient pressure in an unloaded state.

[0043] ​Figure 3 is a medial view of the bladder system 14 showing some of the many dome-shaped pods 70 that are lowered and protruding at the ground-facing surface 38 in contrast to the relatively flat foot-facing surface 31 provided by the full-length sealed chamber 40 having a large number of small, spaced-apart junctions 41 in a repeating pattern. There is an outer peripheral portion of the first panel 30 to which the pattern of junctions 41 does not extend (e.g., the dot junctions 41 are slightly inside the peripheral flange 26). When the chamber of the bladder system 14 is inflated, the outer peripheral portion without junctions 41 forms part of the sidewall 80, and the junctions 41 in the outer peripheral portion form part of the sidewall 80. Figure 4 is not visible in the side view.

[0044] Figure 4 shows that the plurality of stacked polymer panels 30, 32, 34, and 36 are coextensive, each having an outer periphery 28 at the peripheral flange 26. Each of the polymer panels 30, 32, 34, and 36 extends from the forefoot region 16 to the heel region 20 and from the medial side 22 to the lateral side 24. In other words, only four polymer panels are used to construct the bladder system 14, and each panel extends the width and length of the bladder system 14.

[0045] Figure 4 is a cross-sectional view showing that the first sealed chamber 40 is disposed between the foot-facing surface 31 and the plurality of discrete chambers (discrete chambers 46, 48, 49, and 50 are visible in Figure 5 ). Likewise, the plurality of discrete chambers 46, 48, 49, and 50 are disposed between the ground-facing surface 38 and the first sealed chamber 40. Figure 5 is a cross-sectional view showing that the first sealed chamber 40 is disposed between the foot-facing surface 31 and the discrete chambers 42, 44, and 49 (discrete chambers 46 and 48 are not visible in Figure 4 ). Figure 5 and ​ shows different junctions between the stacked panels, including the dot junctions 41 that join the first panel 30 to the second panel 32, the dot junctions 45 that join the second panel 32 to the third panel 34, the junctions 68 that join the third panel 34 to the fourth panel 36, and the junctions between adjacent ones of the stacked panels 30, 32, 34, 36 at the peripheral flange 26. The dot junctions 41 are inside the peripheral flange 26 and join the lower surface of the first panel 30 to the upper surface of the second panel 32.

[0046] The selection of the shape, size, and location of the various junctions between the polymer sheets 30, 32, 34, and 36 provides the desired contoured surface of the final bladder system 14, including the domed pod 70 and the relatively flat foot-facing surface 31, and also provides or prevents fluid communication between the different chambers of the bladder system 14. Prior to joining the junctions, the polymer sheets 30, 32, 34, and 36 are flat sheets that are stacked, coextensive with one another. A solder resist material is applied to the abutment surfaces of the sheets 30, 32, 34, and 36 where no joining is desired. The solder resist material can be referred to as a barrier ink, for example, and can be inkjet printed on the sheets according to a programmed pattern for each sheet 30, 32, 34, and 36 at all selected locations where no joining between adjacent sheets is desired. The stacked flat polymer sheets 30, 32, 34, and 36 are then heat pressed to create the junctions between adjacent sheets at all adjacent sheet surfaces except where the solder resist material was applied. No heat-forming mold or radio frequency soldering is required. In the completed bladder system 14, the areas where the solder resist material was applied will be located in the interior volumes of the various sealed chambers 40, 42, 44, 46, 48, 49, and 50.

[0047] Once joined, the polymer sheets 30, 32, 34, and 36 remain flat and assume the contoured shape of the bladder system 14 only when the chambers 40, 42, 44, 46, 48, 49, and 50 are inflated and then sealed. The polymer sheets 30, 32, 34, and 36 are not heat-formed in a mold. Thus, if the inflation gas is removed, and assuming that no other components are disposed in any of the sealed chambers, and that the polymer sheets 30, 32, 34, and 36 are not bonded to other components, such as an outsole, other midsole layers, or an upper, the polymer sheets 30, 32, 34, and 36 will return to their initial flat state.

[0048] The polymer sheets 30, 32, 34, and 36 can be formed from a variety of materials, including various polymers capable of elastically retaining a fluid such as air or another gas. Examples of polymeric materials for the polymer sheets 30, 32, 34, and 36 include thermoplastic polyurethanes, polyurethanes, polyesters, polyester polyurethanes, and polyether polyurethanes. In addition, the polymer sheets 30, 32, 34, and 36 can each be formed from layers of different materials. In one embodiment, each of the polymer sheets 30, 32, 34, and 36 is formed from a film having one or more layers of thermoplastic polyurethane with one or more barrier layers of ethylene and ethylene vinyl alcohol copolymer (EVOH) that is impermeable to the pressurized fluid contained therein, as described in U.S. Patent No. 6,082,025, which is incorporated herein by reference in its entirety. Each of the polymer sheets 30, 32, 34, and 36 can also be formed from a material that includes alternating layers of thermoplastic polyurethane and ethylene-vinyl alcohol copolymer, as disclosed in U.S. Patent Nos. 5,713,141 and 5,952,065 to Mitchell et al., which are incorporated herein by reference in their entirety. Alternatively, the layers can include ethylene-vinyl alcohol copolymer, thermoplastic polyurethane, and a regrind of ethylene-vinyl alcohol copolymer and thermoplastic polyurethane. The polymer sheets 30, 32, 34, and 36 can also each be a flexible microlayer film that includes alternating layers of a gas barrier material and an elastomeric material, as disclosed in U.S. Patent Nos. 6,082,025 and 6,127,026 to Bonk et al., which are incorporated herein by reference in their entirety. Other suitable materials for the polymer sheets 30, 32, 34, and 36 are disclosed in U.S. Patent Nos. 4,183,156 and 4,219,945 to Rudy, which are incorporated herein by reference in their entirety. Other suitable materials for the polymer sheets 30, 32, 34, and 36 include thermoplastic films containing crystalline materials, as disclosed in U.S. Patent Nos. 4,936,029 and 5,042,176 to Rudy, and polyurethanes including polyester polyols, as disclosed in U.S. Patent Nos. 6,013,340, 6,203,868, and 6,321,465 to Bonk et al., which are incorporated herein by reference in their entirety. In selecting materials for the polymer sheets 30, 32, 34, and 36, engineering properties such as tensile strength, tensile properties, fatigue properties, dynamic modulus, and loss tangent can be considered. The thickness of the polymer sheets 30, 32, 34, and 36 can be selected to provide these properties.

[0049] Because they are isolated from one another, the sealed chambers 40, 42, 44, 46, 48, 49, and 50 can be filled with gas at the same or different inflation pressures to achieve a desired cushioning response. For example, the discrete sealed chambers 42, 44, 46, 48, 49, and / or 50 that are closer to the ground than the first sealed chamber 40 can have a lower inflation pressure than the first sealed chamber 40. Each sealed chamber 40, 42, 44, 46, 48, 49, and 50 maintains a gas at a predetermined pressure to which each sealed chamber is inflated when the bladder system 14 is in an unloaded state. The unloaded state is a state in which the bladder system 14 is not under a steady state load or a dynamic load. For example, the unloaded state is a state in which the bladder system 14 is not bearing any load, such as when it is not worn on a foot. Dynamic compressive loads on the bladder system 14 are due to impacts of the sole structure 10 with the ground, as well as corresponding shoe bed loads and opposing ground loads of a person wearing an article of footwear having the bladder system 14. Dynamic compressive loads can be absorbed by the chambers of the bladder system 14 in an order of increasing stiffness from least to greatest stiffness, with higher inflation pressures associated with greater stiffness. Generally, a smaller volume chamber will reach maximum displacement faster than a larger volume chamber with the same or lower inflation pressure, and thus provide return energy faster than the larger volume chamber under a given dynamic load.

[0050] The stiffness of a cushioning layer such as a sealed fluid chamber is represented by a plot of force versus displacement under dynamic loading, with stiffness being the ratio of change in compressive load (such as Newton force) to displacement of the cushioning layer (such as millimeters of displacement along an axis of the compressive load). The compressive stiffness of different portions of the bladder system 14 will depend in part on the relative inflation pressures. Assuming four stacked sheets 30, 32, 34, 36 of the same material or materials and construction, and having the same thickness, a chamber having the same volume and shape as another chamber, but with a lower inflation pressure, should experience a greater initial displacement under dynamic loading, providing an initial phase of relatively lower stiffness, followed by a subsequent phase of greater stiffness after it reaches its maximum compression. Chambers of equal volume with greater inflation pressure or smaller volume with equal inflation pressure should provide a steeper slope of stiffness on the load-displacement curve. Furthermore, because the entire first sealed chamber 40 is in fluid communication from the heel region 20 to the forefoot region 16, and the entire sealed chamber 49 is likewise in fluid communication from the heel region 20 to the forefoot region 16, preloading of the midfoot region 18 and the forefoot region 16 will occur as the foot compresses the bladder system 14 with an initial heel strike and forward roll, increasing the stiffness of the midfoot region 18 and then the forefoot region 16 during the forward roll. This can advantageously provide a relatively stiff support platform for toe-off.

[0051] The following clauses provide example constructions of the article of footwear disclosed herein.

[0052] Clause 1 : A sole structure for an article of footwear, comprising a midsole, the midsole comprising a bladder system having a forefoot region, a midfoot region, and a heel region,

[0053] wherein the bladder system defines a first sealed chamber holding fluid as a first cushioning layer, the first sealed chamber extending over the forefoot region, the midfoot region, and the heel region, and a plurality of discrete sealed chambers holding fluid isolated from one another, each of the plurality of discrete chambers disposed on a side of the first sealed chamber and fluidically isolated from the first sealed chamber.

[0054] Clause 2: The sole structure of Clause 1, wherein,

[0055] none of the plurality of discrete chambers extend in the forefoot region, the midfoot region, and the heel region.

[0056] Clause 3 : The sole structure of Clause 1, wherein:

[0057] the bladder system defines a foot-facing surface and a ground-facing surface; the first sealed chamber is disposed between the foot-facing surface and the plurality of discrete chambers; and the plurality of discrete chambers is disposed between the ground-facing surface and the first sealed chamber.

[0058] Clause 4: The sole structure of Clause 3, wherein:

[0059] the bladder system comprises a plurality of stacked polymer sheets including an upper sheet at least partially defining the foot-facing surface, a lower sheet at least partially defining the ground-facing surface, and a middle sheet disposed between the upper sheet and the lower sheet; and the first sealed chamber is surrounded by the upper sheet and the middle sheet.

[0060] Clause 5 : The sole structure of Clause 4, wherein,

[0061] the plurality of stacked polymer sheets are joined together at a peripheral flange.

[0062] Clause 6: The sole structure of any of Clauses 4-5, wherein,

[0063] the upper sheet is joined to the middle sheet at a plurality of point junctions spaced apart from one another in the forefoot region, the midfoot region, and the heel region, the first sealed chamber surrounds a perimeter of each point junction, and the foot-facing surface has a plurality of dimples at the plurality of point junctions.

[0064] Clause 7 : The sole structure of Clause 3, wherein:

[0065] The bladder system includes a domed pod extending at the ground-facing surface; the plurality of discrete chambers includes a peripheral heel chamber in the heel region, a central heel chamber in the heel region, a peripheral lateral chamber in the forefoot region, and a medial forefoot chamber in the forefoot region, and the peripheral heel chamber, the central heel chamber, the peripheral lateral chamber in the forefoot region, and the medial forefoot chamber in the forefoot region include a plurality of fluidly connected sub-chambers corresponding to the domed pod.

[0066] Clause 8: The sole structure of Clause 7, wherein,

[0067] The inflation pressure of the gas retained in the peripheral lateral chamber is greater than the inflation pressure of the gas retained in the medial forefoot chamber.

[0068] Clause 9: The sole structure of Clause 8, wherein,

[0069] The inflation pressure of the gas retained in the peripheral lateral chamber is greater than the inflation pressure of the gas retained in the peripheral heel chamber, and greater than the inflation pressure of the gas retained in the central heel chamber.

[0070] Clause 10: The sole structure of Clause 7, wherein:

[0071] The inflation pressure of the gas retained in the peripheral lateral chamber is greater than the inflation pressure of the gas retained in the peripheral heel chamber; the inflation pressure of the gas retained in the peripheral heel chamber is greater than the inflation pressure of the gas retained in the central heel chamber; the inflation pressure of the gas retained in the central heel chamber is greater than the inflation pressure of the gas retained in the medial forefoot chamber.

[0072] Clause 11: The sole structure of Clause 3, wherein:

[0073] The bladder system includes a plurality of stacked polymer sheets including a first sheet at least partially defining the foot-facing surface, a second sheet bonded to the first sheet, the first sealed chamber being enclosed by the first sheet and the second sheet, a third sheet bonded to the second sheet, and a fourth sheet bonded to the third sheet and at least partially defining the ground-facing surface; and wherein at least one of the plurality of discrete chambers is enclosed by the second sheet and the third sheet, and at least one of the plurality of discrete chambers is enclosed by the third sheet and the fourth sheet.

[0074] Clause 12: The sole structure of Clause 3, wherein,

[0075] The bladder system includes a domed pod extending at the ground-facing surface; and at least one of the plurality of discrete chambers includes a plurality of fluidly connected sub-chambers corresponding to the domed pod.

[0076] Clause 13: The sole structure of Clause 12, wherein,

[0077] At least one of the plurality of discrete chambers can include an annular ring portion that is fluidly isolated from and surrounds one of the sub-chambers corresponding to the domed pod.

[0078] Clause 14: The sole structure of Clause 13, wherein,

[0079] The annular ring portion is located at a lateral side of the forefoot region.

[0080] Clause 15: The sole structure of Clause 3, wherein,

[0081] The plurality of discrete chambers includes a peripheral heel chamber having an arcuate portion disposed at a posterior of the heel region, a lateral arm portion extending forward in the heel region from the arcuate portion along a lateral side of the bladder system, and a medial arm portion extending forward in the heel region from the arcuate portion along a medial side of the bladder system, with the medial arm portion spaced apart from the lateral arm portion.

[0082] Clause 16: The sole structure of Clause 15, wherein,

[0083] The plurality of discrete chambers includes a central heel chamber disposed between the medial arm portion and the lateral arm portion of the peripheral heel chamber and forward of the arcuate portion of the peripheral heel chamber.

[0084] Clause 17: The sole structure of Clause 16, wherein,

[0085] The bladder system includes a domed pod extending at the ground-facing surface; and the central heel chamber includes a plurality of fluidly connected sub-chambers corresponding to a plurality of the domed pods arranged in a longitudinally extending row between the lateral arm portion and the medial arm portion of the domed pod.

[0086] Clause 18: The sole structure of Clause 3, wherein,

[0087] The plurality of discrete chambers includes a peripheral lateral chamber extending along a lateral side of the bladder system in the forefoot region; the peripheral lateral chamber is disposed entirely between a longitudinal centerline of the bladder system and a lateral side of the bladder system; the bladder system includes a round pod extending at the ground-facing surface; and the peripheral lateral chamber includes a plurality of fluidly connected sub-chambers corresponding to a plurality of round pods in a longitudinally extending row of round pods disposed along a lateral side of the ground-facing surface in the forefoot region.

[0088] Clause 19: The sole structure of any of clauses 18, wherein,

[0089] The plurality of discrete chambers includes a medial forefoot chamber disposed along a medial side of the bladder system in the forefoot region and extending on the longitudinal centerline.

[0090] Clause 20: The sole structure of any of clauses 18-19, wherein,

[0091] One of the plurality of discrete chambers includes an annular ring portion that is fluidly isolated from and surrounds one of the sub-chambers of the peripheral lateral chamber.

[0092] To aid and illustrate the description of the various embodiments, various terms are defined herein. The following definitions apply to all the embodiments (including the claims) unless otherwise indicated. In addition, all references cited are incorporated herein in their entirety.

[0093] “Article of footwear,”“article of footwear,” and“footwear” can be considered machines and manufactures. An article of footwear ready to be worn (e.g., a shoe, sandal, boot, etc.) prior to final assembly into a finished article, as well as discrete components of an article of footwear (e.g., a midsole, an outsole, an upper assembly, etc.) prior to final assembly into an article of footwear ready to be worn are considered and alternatively referred to herein as“articles of footwear” in the singular or plural.

[0094] “one”, “an”, “the”, “at least one”, and “one or more” are used interchangeably to mean that there is at least one of the item present. The use of the terms “one”, “an” and “the” and “at least one” or “one or more” to describe a singular or plural number of objects is not limiting when applied to equivalents of those terms (for example, “a” and “one” can be used interchangeably with “at least one” or “one or more”). All numerical values of parameters (e.g., of quantities or conditions) in this specification, unless otherwise indicated, are to be understood as being modified in all instances by the term “about” whether or not “about” is expressly recited in the numerical value. “About” indicates that the value presented is a close approximation to the actual value, and that slight imprecision can be present to the nature of the value. If an imprecision is present, it will be apparent from the context in which the numerical value is presented. If not expressly recited, “about” can indicate variations that can arise from the use of measurement and the ordinary methods of using such a parameter. In addition, disclosure of a range is understood to disclose all values and sub-ranges within that range. For example, a disclosure of a range of 1-10 is understood to disclose a range of 1-6, 4-8, 3-9, 2-10, 1- 10, etc.

[0095] The terms “comprise”, “comprising”, “contain”, “containing”, and “have” are inclusive, and therefore specify the presence of stated features, steps, operations, elements, and / 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 can be altered in possible ways, and other or alternative steps can be employed, where possible. The term “or” as used in this description, includes any one and all combinations of the associated listed items. The term “any” should be construed in the way that includes any possible combination of the referenced items, including “any one” of the referenced items. The term “any” should be construed in the way that includes any possible combination of the referenced claims, including “any one” of the referenced claims.

[0096] For consistency and convenience, directional adjectives are employed throughout the detailed description corresponding to the illustrated embodiments. One of ordinary skill in the art will recognize that terms such as “above”, “below”, “up”, “down”, “top”, “bottom”, and the like can be descriptive relative to the figures and are not meant to limit the scope of the invention as defined by the claims.

[0097] The term “longitudinal” refers to the direction extending the length of a component. For example, the longitudinal direction of a shoe extends between the forefoot region and the heel region of the shoe. The term “forward” or “front” is used to refer to the general direction from the heel region to the forefoot region, and the term “rearward” or “rear” is used to refer to the opposite direction, i.e., from the forefoot region toward the heel region. In some cases, a component can be identified with a longitudinal axis and forward and rearward longitudinal directions along that axis. The longitudinal direction or axis can also be referred to as the forward and rearward direction or axis.

[0098] The term“lateral” refers to a direction extending a width of a component. For example, a lateral direction of a shoe extends between a lateral side and a medial side of the shoe. A lateral direction or axis can also be referred to as a side-to-side direction or axis or a medial-lateral direction or axis.

[0099] The term“vertical” refers to a direction that is generally perpendicular to both the lateral and longitudinal directions. For example, in the case of a shoe sole laid flat on a ground surface, a vertical direction can extend upward from the ground surface. It will be understood that each of these directional adjectives can be applied to individual components of a sole. The term“upwardly” or“upward” refers to a vertical direction pointing toward a top of a component, which can include a back of a footwear upper, a securement region, and / or a throat. The term“downwardly” or“downward” refers to a vertical direction opposite the upward direction, which is toward a bottom of a component, and can generally point toward a bottom of a footwear article sole structure.

[0100] An“interior” of an article of footwear, such as a shoe, refers to a portion of the space occupied by a wearer’s foot when the shoe is worn. An“interior side” of a component refers to a side or surface of a component that, in an assembled article of footwear, faces toward (or will face toward) the interior of the component or article of footwear. An“exterior side” or“exterior” of a component refers to a side or surface of a component that, in an assembled shoe, is oriented (or will be oriented) away from the interior of the shoe. In some cases, other components can be between the interior side of a component and the interior in an assembled article of footwear. Similarly, other components can be between the exterior side of a component and the space outside of an assembled article of footwear. Further, the terms“inwardly” and“inward” refer to a direction toward the interior of an article of footwear, such as a shoe, or a component, and the terms“outwardly” and“outward” refer to a direction toward the exterior of an article of footwear, such as a shoe, or a component. Additionally, the term“proximal” refers to a direction closer to the center of an article of footwear or toward a foot when a foot is inserted into the article of footwear while a user is wearing the shoe. Likewise, the term“distal” refers to an opposite location further from the center of an article of footwear or from a foot when a foot is inserted into the article of footwear while a user is wearing the shoe. Thus, the terms proximal and distal can be understood to provide generally opposite terms to describe relative spatial locations.

[0101] While various embodiments have been described, this description is intended to be exemplary, rather than limiting, and many variations are possible without departing from the spirit of the present disclosure. Unless otherwise specified, any of the embodiments can be combined with any other embodiment or elements of any other embodiment or variations thereof. Accordingly, the embodiments are not limited, except as by the appended claims and their equivalents. Similarly, modifications and changes can be made within the scope of the following claims.

[0102] While several modes for carrying out various aspects of the present teachings have been described in detail, those skilled in the art who have the benefit of this disclosure will appreciate that various alternatives to the teachings described herein can be practiced within the scope of the appended claims. It is intended that the appended claims cover all such alternatives as fall within the scope of the entire range of equivalents, implicitly claimed, of the range of alternatives insubstantially distinct, or of identical articles, made by industry, sold on the market, to include technical equivalents, and the entire scope of equivalents falling within the claims.

Claims

1. A sole structure for an article of footwear, comprising: a midsole including a bladder system having a forefoot region, a midfoot region, and a heel region, wherein the bladder system defines: a first sealed chamber holding fluid as a first cushioning layer; and discrete chambers holding fluid in isolation from one another, each of the discrete chambers disposed on a side of the first sealed chamber and fluidly isolated from the first sealed chamber, wherein: the bladder system defines a foot-facing surface and a ground-facing surface; the first sealed chamber is disposed between the foot-facing surface and the discrete chambers; the first sealed chamber extends over the forefoot region, the midfoot region, and the heel region; the discrete chambers are disposed between the ground-facing surface and the first sealed chamber; the bladder system includes dome pods extending at the ground-facing surface; at least one of the discrete chambers includes fluidly connected sub-chambers, the sub-chambers corresponding to the dome pods; the discrete chambers include a peripheral lateral chamber extending along a lateral side of the bladder system in the forefoot region, the peripheral lateral chamber disposed entirely between a longitudinal centerline of the bladder system and the lateral side of the bladder system, the peripheral lateral chamber includes sub-chambers, the sub-chambers corresponding to a plurality of the dome pods disposed in a longitudinally extending row along the lateral side in the forefoot region, and another of the discrete chambers includes an annular ring portion fluidly isolated from the fluidly connected sub-chambers of the peripheral lateral chamber and surrounding only one of the sub-chambers of the peripheral lateral chamber.

2. The sole structure of Claim 1, wherein, none of the discrete chambers extends in each of the forefoot region, the midfoot region, and the heel region.

3. The sole structure of claim 1, wherein, the discrete chambers further include a peripheral heel chamber in the heel region, a central heel chamber in the heel region, and a medial forefoot chamber in the forefoot region.

4. The sole structure of claim 1, wherein, the discrete chambers include the peripheral heel chamber having: an arcuate portion disposed at a posterior of the heel region, a lateral arm portion extending forward from the arcuate portion along a lateral side of the bladder system in the heel region, and a medial arm portion extending forward from the arcuate portion along a medial side of the bladder system in the heel region, wherein the medial arm portion is spaced apart from the lateral arm portion.

5. The sole structure of claim 4, wherein, the discrete chambers include the central heel chamber disposed between the medial arm portion and the lateral arm portion of the peripheral heel chamber and forward of the arcuate portion of the peripheral heel chamber.

6. The sole structure of Claim 5, wherein, the dome pods are disposed in longitudinally extending rows between the lateral arm portion and the medial arm portion.

7. The sole structure of claim 1, wherein, the discrete chambers include the medial forefoot chamber disposed along a medial side of the bladder system in the forefoot region and extending on the longitudinal centerline.

8. The sole structure of claim 1, wherein, the annular ring portion is at a lateral side of the forefoot region.

9. The sole structure of claim 1, wherein: the bladder system includes a plurality of stacked polymer sheets including: an upper sheet at least partially defining the foot-facing surface, a lower sheet at least partially defining the ground-facing surface, and a An intermediate sheet is disposed between the upper sheet and the lower sheet, and the first sealed chamber is enclosed by the upper sheet and the intermediate sheet.

10. The sole structure of Claim 9, wherein, The plurality of stacked polymer sheets are bonded together at a peripheral flange.

11. The sole structure of claim 10, wherein, The upper sheet is bonded to the intermediate sheet at a plurality of point bonds spaced apart from one another, the first sealed chamber surrounds a perimeter of each point bond, and the foot-facing surface has a plurality of dimples at the plurality of point bonds.

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