Tilt adjuster with multiple individual chambers

Abstract

To provide a footwear article having a sole structure.SOLUTION: A sole structure of a footwear article may include chambers and a transfer channel containing an electrorheological fluid. Electrodes may be positioned to create, in response to a voltage across the electrodes, an electrical field in at least a portion of the electrorheological fluid in the transfer channel. The sole structure may further include a controller including a processor and memory. At least one of the processor and memory may store instructions executable by the processor to perform operations that include maintaining the voltage across the electrodes at one or more flow-inhibiting levels at which flow of the electrorheological fluid through the transfer channel is blocked, and that further include maintaining the voltage across the electrodes at one or more flow-enabling levels permitting flow of the electrorheological fluid through the transfer channel.SELECTED DRAWING: Figure 12B

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application No. 62 / 552,551, entitled "INCLINE ADJUSTER WITH MULTIPLE DISCRETE CHAMBERS," filed August 31, 2017. No. 62 / 552,551 is incorporated by reference in its entirety. [Background technology]

[0002] Conventional footwear generally includes an upper and a sole structure. The upper provides coverage for the foot and stably positions the foot relative to the sole structure. The sole structure is secured to a lower portion of the upper and is configured to be positioned between the foot and the ground when the wearer is standing, walking, or running.

[0003] Conventional footwear is often designed with the goal of optimizing the shoe for a particular condition or set of conditions. For example, sports such as tennis and basketball require substantial side-to-side movement. Shoes designed for wear during such sports often include substantial reinforcement and / or support in areas that experience greater forces during side-to-side movement. As another example, running shoes are often designed for the wearer's linear, forward movement. Difficulties can arise when the shoe must be worn in changing conditions or during multiple different types of movements. Summary of the Invention

[0004] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. It is not intended to identify key features or essential features of the invention.

[0005] In at least some embodiments, the sole structure may include a base, a tilt adjuster, and a support plate. The base may be disposed in a forefoot portion of the sole structure, a midfoot portion of the sole structure, and a heel portion of the sole structure. The support plate may be disposed in at least the forefoot portion of the sole structure. The tilt adjuster may include a forefoot section disposed between the base and the support plate in the forefoot portion of the sole structure and may include at least three chambers. Each of the chambers may contain an electrorheological fluid and may be configured to change its outward extension in response to a change in the volume of the electrorheological fluid in the chamber. The chambers may be connected in series by transmission channels, each of which allows flow between two of the chambers. The transmission channels may include a flow-regulating transmission channel including opposing first and second electrodes extending along an interior of the electric field-generating portion of the flow-regulating transmission channel.

[0006] In some embodiments, the tilt adjuster may include a body and at least three variable-volume chambers extending outward from the body. Each of the chambers may contain an electrorheological fluid and may be configured to vary its outward extension in response to changes in the volume of the electrorheological fluid within the chamber. The chambers may be connected in series by transfer channels, each of which allows flow between two of the chambers. The transfer channels may include a flow-regulating transfer channel. The flow-regulating transfer channel may include opposing first and second electrodes extending along an interior of the electric field-generating portion of the flow-regulating transfer channel. The electric field-generating portion may have a length L and an average width W, and the ratio L / W may be at least 50.

[0007] In some embodiments, a method of fabricating a tilt adjuster may include molding a first component including a top side and a first portion of a plurality of transmission channels defined in the top side. One of the first portion of the transmission channels may include an exposed first electrode. The method may include molding a second component including a bottom side, a top side, and a second portion of the plurality of transmission channels defined in the bottom side. One of the second portion of the transmission channels may include an exposed second electrode. An upper portion of each of the at least three chambers may extend outward from the top side of the second component. The method may further include bonding the top side of the first component to the bottom side of the second component, filling the interior volume with an electrorheological fluid, and sealing the interior volume.

[0008] Further embodiments are described herein. [Brief explanation of the drawings]

[0009] Several embodiments are illustrated by way of example, and not by way of limitation, in the accompanying drawings, in which like reference numerals refer to similar elements. [Figure 1] FIG. 1 illustrates a medial side view of a shoe according to some embodiments. [Figure 2A] FIG. 2 is a bottom view of the sole structure of the shoe of FIG. 1. [Figure 2B] FIG. 2 is a bottom view of the sole structure of the shoe of FIG. 1 with the forefoot outsole element removed. [Figure 2C] FIG. 2 is a bottom view of a forefoot outsole element of the sole structure of the shoe of FIG. [Figure 3] 2 is a partially exploded, inner perspective view of the sole structure of the shoe of FIG. 1. FIG. [Figure 4A] FIG. 2 is an enlarged rear lateral top perspective view of a tilt adjuster of the shoe of FIG. 1. [Figure 4B] FIG. 4B is a top view of the tilt adjuster of FIG. 4A. [Figure 4C] 4C is a cross-sectional view taken along the arrow AA in the plane shown in FIG. 4B. [Figure 4D] 4C is a cross-sectional view taken along the arrow BB in the plane shown in FIG. 4B. [Figure 5A] 4B shows the first layer of the first component of the tilt adjuster of FIG. 4A and the first metallic electrode. [Figure 5B] 5B shows the first layer of FIG. 5A after the first electrode of FIG. 5A has been attached. [Figure 5C] 4B shows the first component of the tilt adjuster of FIG. 4A after molding a second layer over the first layer and attached first electrode. [Figure 6A] 4B shows the first layer and metallic second electrode of the second component of the tilt adjuster of FIG. 4A. [Figure 6B] 6B shows the first layer of FIG. 6A after the second electrode of FIG. 6A has been attached. [Figure 6C] 4B shows the second component of the tilt adjuster of FIG. 4A after molding a second layer over the first layer and attached second electrode. [Figure 7] 4A from the first component of FIG. 5C and the second component of FIG. 6C. [Figure 8A] FIG. 13 is an exterior top perspective view of the tilt adjuster after assembly and before filling with ER fluid. [Figure 8B] FIG. 13 is a bottom perspective view of the inside of the tilt adjuster after assembly and before filling with ER fluid. [Figure 9] 4C is an enlarged cross-sectional view taken at arrow CC in the plane indicated in FIG. 4B, showing a portion of the transmission channel of the tilt adjuster of FIG. 4A. [Figure 10] 4C is a top rear interior perspective view taken at arrow AA in the plane shown in FIG. 4B, and is a partial schematic cross-sectional view further showing two chamber caps. [Figure 11] FIG. 2 is a block diagram showing components of the electrical system of the shoe of FIG. 1. [Figure 12A] 2 is a partial schematic cross-sectional view illustrating the operation of the tilt adjuster of the shoe of FIG. 1 going from a minimum tilt state to a maximum tilt state. [Figure 12B] 2 is a partial schematic cross-sectional view illustrating the operation of the tilt adjuster of the shoe of FIG. 1 going from a minimum tilt state to a maximum tilt state. [Figure 12C]2 is a partial schematic cross-sectional view illustrating the operation of the tilt adjuster of the shoe of FIG. 1 going from a minimum tilt state to a maximum tilt state. [Figure 13A] 10 is a graph of foot state, pressure difference, voltage level, and tilt angle at various times during the transition from minimum to maximum tilt. [Figure 13B] 10 is a graph of foot state, pressure difference, voltage level, and tilt angle at various times during the transition from maximum to minimum tilt. [Figure 14A] 10A-10C are schematic illustrations of operations in a process for molding components of a tilt adjuster; [Figure 14B] 10A-10C are schematic illustrations of operations in a process for molding components of a tilt adjuster; [Figure 14C] FIG. 10 is a top view of a mold for forming a tilt adjuster according to another embodiment. [Figure 14D] FIG. 10 is a top view of a mold for forming a tilt adjuster according to another embodiment. [Figure 15A] FIG. 16 is a partial schematic cross-sectional view showing a first example of molding a tilt adjuster component using the mold of FIGS. 14C and 14D. [Figure 15B] FIG. 16 is a partial schematic cross-sectional view showing a first example of molding a tilt adjuster component using the mold of FIGS. 14C and 14D. [Figure 15C] FIG. 16 is a partial schematic cross-sectional view showing a first example of molding a tilt adjuster component using the mold of FIGS. 14C and 14D. [Figure 15D] FIG. 16 is a partial schematic cross-sectional view showing a first example of molding a tilt adjuster component using the mold of FIGS. 14C and 14D. [Figure 15E] FIG. 16 is a partial schematic cross-sectional view showing a first example of molding a tilt adjuster component using the mold of FIGS. 14C and 14D. [Figure 15F] FIG. 16 is a partial schematic cross-sectional view showing a first example of molding a tilt adjuster component using the mold of FIGS. 14C and 14D. [Figure 16A]FIG. 16 is a partial schematic cross-sectional view showing a second example of molding a tilt adjuster component using the mold of FIGS. 14C and 14D. [Figure 16B] FIG. 16 is a partial schematic cross-sectional view showing a second example of molding a tilt adjuster component using the mold of FIGS. 14C and 14D. [Figure 16C] FIG. 16 is a partial schematic cross-sectional view showing a second example of molding a tilt adjuster component using the mold of FIGS. 14C and 14D. [Figure 16D] FIG. 16 is a partial schematic cross-sectional view showing a second example of molding a tilt adjuster component using the mold of FIGS. 14C and 14D. [Figure 16E] FIG. 16 is a partial schematic cross-sectional view showing a second example of molding a tilt adjuster component using the mold of FIGS. 14C and 14D. [Figure 16F] FIG. 16 is a partial schematic cross-sectional view showing a second example of molding a tilt adjuster component using the mold of FIGS. 14C and 14D. DETAILED DESCRIPTION OF THE INVENTION

[0010] In various types of activities, it can be advantageous for a shoe wearer to change the shape of a shoe or a portion of a shoe while running or participating in other activities. In many running competitions, for example, athletes run around tracks with curved sections, also known as "corners." In some cases, in sprint events such as 200-meter or 400-meter races, athletes may run around corners of the track at a sprint pace. However, running around flat curves at a fast pace can be biomechanically inefficient and require awkward body movements. To counteract this effect, some running tracks have sloped corners. This slope allows for more efficient body movement, typically resulting in faster running times. Tests have shown that similar benefits can be achieved by modifying the shape of a shoe. In particular, running around corners on a flat track wearing shoes with insoles that slope relative to the ground can mimic the benefits of running around sloped corners wearing shoes with non-sloped insoles. However, sloped insoles are disadvantageous on straight sections of the running track. Footwear that could provide a midsole that was tilted when cornering and reduced or eliminated when running on straight track sections could provide significant advantages.

[0011] In footwear according to some embodiments, electrorheological (ER) fluids are used to change the shape of one or more portions of a shoe. ER fluids typically comprise non-conductive oil or other fluids in which very small particles are suspended. In some types of ER fluids, the particles may have diameters of 5 microns or less and may be formed from polystyrene or another polymer with dipolar molecules. When an electric field is imposed across the ER fluid, the viscosity of the fluid increases as the strength of the field increases. As described in more detail below, this effect can be used to control fluid transport and modify the shape of footwear components. While track shoe embodiments are described first, other embodiments include footwear intended for other sports or activities.

[0012] The terms "shoe" and "article of footwear" are used interchangeably herein to refer to an article intended to be worn on a human foot. A shoe may or may not encase the wearer's entire foot. For example, a shoe may include a sandal-like upper that exposes a large portion of the wearer's foot. The elements of a shoe can be described based on the area and / or anatomy of the foot of the person wearing the shoe, and by assuming that the interior of the shoe generally conforms to and is otherwise appropriately sized for the wearer's foot. The forefoot region of the foot includes the anterior ends and body portions of the metatarsals and the phalanges. A forefoot element of a shoe is an element having one or more portions that are positioned below, above, laterally and / or medially, and / or in front of the wearer's forefoot (or portion thereof) when the shoe is worn. The midfoot region of the foot includes the cuboid, navicular, and cuneiform bones, and the bases of the metatarsals. A midfoot element of a shoe is an element having one or more portions that are positioned below, above, and / or on the lateral and / or medial side of a wearer's midfoot (or portion thereof) when the shoe is worn. The heel region of the foot includes the talus and calcaneus. A heel element of a shoe is an element having one or more portions that are positioned below, above, and / or on the lateral and / or medial side of a wearer's heel (or portion thereof) when the shoe is worn. The forefoot region may overlap with the midfoot region, as may the midfoot region and heel region.

[0013] Throughout the following description and drawings, similar elements may be identified using a common number and a different additional letter (e.g., lateral chambers 35a, 35b, and 35c). Elements identified in this manner may also be identified collectively (e.g., lateral chambers 35) or inclusively (e.g., a lateral chamber 35) using only the number.

[0014] 1 is a medial side view of a track shoe 10, according to some embodiments. The lateral side of shoe 10 has a similar configuration and appearance but is configured to correspond to the lateral side of a wearer's foot. Shoe 10 is configured for wear on the right foot and is one of a pair that includes a shoe (not shown) that is a mirror image of shoe 10 and is configured for wear on the left foot. However, as described in more detail below, shoe 10 and its corresponding left shoe can be configured in various ways to change their shape under a given set of conditions.

[0015] Shoe 10 includes upper 11 attached to sole structure 12. Upper 11 can be formed from any of a variety of types or materials and have any of a variety of different constructions. In some embodiments, for example, upper 11 may be knitted as a single unit and may not include any type of lining bootie. In some embodiments, upper 11 may be slip-lasted by sewing the bottom edge of upper 11 to enclose the interior space of the foot well. In other embodiments, upper 11 may be Strobel-lasted or in some other manner. Battery assembly 13 is located in the rear heel region of upper 11 and includes a battery that provides power to a controller. The controller is not visible in FIG. 1 but is described below in connection with other figures.

[0016] The sole structure 12 includes a midsole 14, an outsole 15, and a tilt adjuster 16. The tilt adjuster 16 is located between the outsole 15 and the midsole 14. As described in more detail below, the tilt adjuster 16 includes an inner fluid chamber that supports a medial forefoot portion of the midsole 14, as well as an outer fluid chamber that supports a lateral forefoot portion of the midsole 14. ER fluid can be transferred between the chambers through transfer channels that are in fluid communication with the interiors of the chambers. Such fluid transfer can increase the height of one chamber relative to the other, resulting in a tilt in the portion of the midsole 14 that is disposed above the chambers. If further flow of ER fluid through one of the channels is interrupted, the tilt is maintained until ER fluid flow is allowed to resume.

[0017] Outsole 15 forms the ground-contacting portion of sole structure 12. In the embodiment of shoe 10, outsole 15 includes a forward outsole section 17 and a rear outsole section 18. The relationship between forward outsole section 17 and rear outsole section 18 can be seen by comparing the bottom view of sole structure 12 in FIG. 2A with the bottom view of sole structure 12 with forefoot outsole section 17 removed in FIG. 2B. FIG. 2C is a bottom view of forefoot outsole section 17 removed from sole structure 12. As can be seen in FIG. 2A, forward outsole section 17 extends through the forefoot and central midfoot regions of sole structure 12 and tapers to a narrow end 19. End 19 is attached to rear outsole section 18 at joint 20 located in the heel region. Rear outsole section 18 extends above the midfoot region. Forefoot outsole section 17 pivots about longitudinal axis L1 that passes through joint 20. In particular, forefoot outsole section 17 rotates about axis L1 when the forefoot portion of midsole 14 is tilted relative to forefoot outsole section 17, as described below.

[0018] Outsole 15 may be formed of a polymer or polymer composite and may include rubber and / or other wear-resistant materials on the ground-contacting surface. Traction elements 21 may be molded into or otherwise formed within the bottom of outsole 15. Forefoot outsole section 17 may also include receptacles that hold one or more removable spike elements 22. In other embodiments, outsole 15 may have different configurations.

[0019] The midsole 14 includes a midsole 25. In embodiments of the shoe 10, the midsole 25 has a size and shape that generally corresponds to the contours of a human foot, is a single piece that extends the entire length and width of the midsole 14, and includes a contoured upper surface 26 (shown in FIG. 3). The contour of the upper surface 26 is configured to generally correspond to the shape of the plantar region of the human foot and to provide arch support. The midsole 25 may be formed from ethylene vinyl acetate (EVA) and / or one or more other closed-cell polymer foam materials. Extending the medial and lateral sides of the rear outsole section 18 upwardly may also provide additional medial and lateral support for the wearer's foot. In other embodiments, the midsole may have a different configuration. For example, the midsole may not cover the entire midsole or may be absent altogether, and / or the midsole may include other components.

[0020] FIG. 3 is a partially exploded, medial perspective view of sole structure 12. A bottom support plate 29 is positioned in the plantar region of shoe 10. In the embodiment of shoe 10, bottom support plate 29 is attached to an upper surface 30 of forward outsole section 17. Bottom support plate 29, which may be formed from a relatively stiff polymer or polymer composite, helps stiffen the forefoot region of forward outsole section 17 and provide a stable base for tilt adjuster 16. Front forefoot force sensitive resistors (FSRs) 32a, mid forefoot FSR 32b, and rear forefoot FSR 32c are attached to an upper surface 33 of bottom support plate 29 on the medial side of the forefoot region. Similarly, front forefoot FSR 31a, mid forefoot FSR 31b, and rear forefoot FSR 31c are attached to upper surface 33 on the lateral side of the forefoot region. FSRs 31 and 32 provide outputs that help determine the pressure in the chamber of tilt adjuster 16, as described below.

[0021] The tilt adjuster 16 is attached to the upper surface 33 of the lower support plate 29 and to the upper surface 43 of the rear outsole section 18. The outer chambers 35a, 35b, and 35c of the tilt adjuster 16 are positioned above the outer FSRs 31a, 31b, and 31c, respectively. The inner chambers 36a, 36b, and 36c of the tilt adjuster 16 are positioned above the inner FSRs 32a, 32b, and 32c, respectively. Chamber caps 37a, 37b, and 37c are positioned above the chambers 35a, 35b, and 35c, respectively. Chamber caps 38a, 38b, and 38c are positioned above the chambers 36a, 36b, and 36c, respectively. As will be described in further detail in connection with FIG. 10 , the chamber caps 37 and 38 provide an interface between the chambers 35 and 36 and the underside of the upper support plate 41. An upper support plate 41 is also disposed in the plantar region of the shoe 10 and is positioned over the tilt adjuster 16. In the embodiment of the shoe 10, the upper support plate 41 is generally aligned with the bottom support plate 29. The upper support plate 41, which may also be formed from a relatively stiff polymer or polymer composite, provides a stable, relatively non-deformable area against which the tilt adjuster 16 may press and which supports the forefoot region of the midsole 14.

[0022] A portion of the lower surface of midsole 25 in the forefoot region is attached to upper surface 42 of upper support plate 41. A portion of the lower surface of midsole 25 in the heel and midfoot region is attached to upper surface tilt adjuster 16 in the heel and midfoot region of midsole 25. End 19 of forward outsole section 17 is attached to rear outsole section 18 behind a rearmost position 44 of the leading edge of section 18 to form joint 20. In some embodiments, end 19 may be a tab that slides into a slot formed in section 18 at or near position 14 and / or may be sandwiched between upper surface 43 and the lower surface of tilt adjuster 16.

[0023] 3 also shows a DC-to-high voltage-to-DC converter 45 and a printed circuit board (PCB) 46 of the controller 47. The converter 45 converts a low-voltage DC electrical signal into a high-voltage (e.g., 5000 V) DC signal that is applied to electrodes in the tilt adjuster 16. The PCB 46 includes one or more processors, memory, and other components and is configured to control the tilt adjuster 16 through the converter 45. The PCB 46 also receives inputs from the FSRs 31 and 32 and receives power from the battery unit 13. The PCB 46 and converter 45 may be attached to the top surface of the forward outsole section 17 in the midfoot region 48.

[0024] Figure 4A is an enlarged rear outer top perspective view of the tilt adjuster 16. Figure 4B is an enlarged top view of the tilt adjuster 16. Figure 4C is a cross-sectional view taken at arrow AA in the plane shown in Figure 4B. Figure 4D is a cross-sectional view taken at arrow BB in the plane shown in Figure 4B.

[0025] The tilt adjuster 16 includes a body 51. A portion of the outer chamber 35b is bounded by a flexible contoured wall 53b extending upward from the exterior of the top 52 of the body 51. The contoured wall 53b includes an outer section 73b, an inner side section 75b, and a central section 71b. Another portion of the outer chamber 35b is bounded by a corresponding region 55b in the body 65 (FIGS. 4C and 4D). The outer chambers 35a and 35c each have a structure similar to that of the chamber 35b, including respective flexible contoured walls 53a and 53c extending upward from the exterior of the top 52 of the body 51, and a respective portion bounded by a corresponding region in the body 51 similar to region 55b. The walls 53a and 53c each include a respective outer section 73a and 73c, a respective inner section 75a and 75c, and a respective central section 71a and 71c.

[0026] A portion of inner chamber 36c is bounded by a flexible contoured wall 54c extending upward from the inside of top side 52. Contoured wall 54c includes side sections 74c and a central section 72c. Another portion of inner chamber 36c is bounded by a corresponding region 56c in body 51. Inner chambers 36a and 36b each have a structure similar to chamber 36c, including respective flexible contoured walls 54a and 54b extending upward from the inside of top side 52 of body 51, with respective portions bounded by a corresponding region in body 51 similar to region 56c. Walls 54a and 54b each include respective side sections 74a and 74b and respective central portions 72a and 72b.

[0027] In some embodiments of FIGS. 4A-4D, chambers 35 and 36 are positioned to accommodate the high impact forces experienced during various points in the walking cycle when going around corners on a track. Chamber 36a is positioned in the completed shoe 10 to generally correspond to the wearer's big toe. Chamber 36b is positioned to correspond to the head of the wearer's first metatarsal (balloon). Chamber 36c is positioned to correspond to the base of the wearer's first metatarsal. Chamber 35a is positioned to correspond to the wearer's fifth distal phalanx (pinky toe). Chamber 35b is positioned to correspond to the head of the wearer's fifth metatarsal. Chamber 35c is positioned to correspond to the base of the wearer's fifth metatarsal.

[0028] In some embodiments, the chambers are circular in the plane of the body through which they extend and have diameters between 15 millimeters and 30 millimeters. In some embodiments, chamber 36a has a diameter of 20 millimeters, and chambers 36b, 36c, and 35a-35c each have a diameter of 25 millimeters. Minimizing the size of the chambers minimizes deformation of the chambers when footwear 10 impacts the ground during actual use, which may minimize noise in the control system.

[0029] As can be seen in Figure 4B, chambers 35a, 35b, 35c, 36c, 36b, and 36a of tilt adjuster 16 are connected in series by transmission channels, each connecting a different pair of chambers. Outer chamber 35a is in fluid communication with outer chamber 35b through transmission channel 61, which is defined in a portion of body 51 and extends between chambers 35a and 35b. Because the tilt adjuster 16 in the embodiment of Figures 4A-4D is opaque, the locations of transmission channel 61 and the other transmission channels are indicated by small dashed lines in Figure 4B. Outer chamber 35b is in fluid communication with outer chamber 35c through transmission channel 62, which is defined in a portion of body 51 and extends between chambers 35b and 35c. Inner chamber 36a is in fluid communication with inner chamber 36b through transmission channel 65, which is defined in a portion of body 51 and extends between chambers 36a and 36b. Inner chamber 36b is in fluid communication with inner chamber 36c through transmission channel 64, which is defined in a portion of body 51 and extends between chambers 36b and 36c. Inner chamber 36c is in fluid communication with outer chamber 35c via transmission channel 63, which extends rearward from chamber 36c to the heel region of body 31 and then forward back to outer chamber 35c.

[0030] As can be seen in Figure 4B, the transfer channels do not extend directly between chambers 36c and 35b. Therefore, portions of the transfer channels are not visible in Figure 4C. However, transfer channel 62 and a portion of transfer channel 63 are visible in Figure 4D. Transfer channels 61, 64, and 65, as well as the remainder of transfer channel 63, are similar in their chamber connections and vertical position relative to body 51 as the transfer channels shown in Figure 4D. Furthermore, the width and height of all transfer channels are generally constant, at least in some embodiments.

[0031] ER fluid 69 fills chambers 35 and 36 and transfer channels 61-65. An example of an ER fluid that may be used in some embodiments is sold by ERF Produktion Wurzberg GmbH under the name "RheOil 4.0." The internal volume of outer chamber 35 may change as ER fluid 69 flows into or out of outer chamber 35. The portion of each chamber 35 formed by wall 53 is configured to expand when ER fluid 69 flows into chamber 35, displacing central section 71 of wall 53 upward from body 51. The internal volume of inner chamber 36 may similarly change as ER fluid 69 flows into or out of inner chamber 36. The portion of each chamber 36 formed by the walls 54 is configured to expand when the ER fluid 69 flows into the chamber 36 , thereby displacing a central section 72 of the wall 54 upwardly from the body 51 .

[0032] A pair of opposing electrodes is positioned within transfer channel 63 on the bottom and top sides and extends along an electric field-generating portion 77 of transfer channel 63, shown by the large dashed line in FIG. 4B . Separate leads are in electrical contact with the bottom and top electrodes, respectively, and are connected to converter 45. Transfer channel 63 has a serpentine shape to increase the surface area for the electrodes within channel 63, generating an electric field in ER fluid 69 within channel 63. In some embodiments, transfer channel 63 may have a maximum height h between electrodes of 1 millimeter (mm), an average width (w) of 2 mm, and a length of at least 250 mm along the flow direction between chambers 35c and 36c. In some embodiments, transfer channel 63 may have a maximum height h between electrodes of 1 millimeter (mm), an average width (w) of 4 mm, and a length of at least 250 mm along the flow direction between chambers 35c and 36c. In some embodiments, the length of transfer channel 63 may exceed 270 mm.

[0033] In some embodiments, the height of the transmission channel may be practically limited to a range of at least 0.250 mm to 3.3 mm or less. The tilt adjuster, constructed of a flexible material, may flex while the shoe is in use. Flexing across the transmission channel results in a localized reduction in height at the bending point. If not adequately tolerated, the corresponding increase in field strength may exceed the maximum dielectric strength of the ER fluid, resulting in field collapse. In the extreme, the electrodes may be so close together that they actually touch, resulting in field collapse.

[0034] The viscosity of ER fluids increases with the applied electric field strength. The effect is nonlinear, with the optimal electric field strength ranging from 3 to 6 kilovolts per millimeter (kV / mm). High-voltage DC-DC converters used to boost 3-5 V batteries may be limited to less than 2 W or a maximum output voltage of 10 kV or less due to physical size and safety considerations. To maintain the electric field strength within the desired range, the height of the transmission channel may be limited to a maximum of approximately 3.3 mm (10 kV / 3 kV / mm) in some embodiments.

[0035] The width of the transfer channel may be practically limited to a range of at least 0.5 mm to 4 mm or less. The maximum width of the channel may be limited by the physical space between the chambers. Furthermore, the equivalent series resistance of the ER fluid also decreases as the channel width increases, which would increase power consumption. For shoe sizes down to M7 (US), the practical width may be limited to less than 4 mm.

[0036] Opposing electrodes in the electric field-generating portion 77 of the transfer channel 63 can be energized to increase the viscosity of the ER fluid 69 in the electric field-generating portion 77, thereby slowing or stopping the flow of the ER fluid 69 through the channel 63. When flow through the transfer channel 63 is enabled, a downward force on the central section 72 of the inner chamber 36 pushes the ER fluid 69 from chamber 36, through the transfer channel 63, and into chamber 35. As the ER fluid 69 is transferred from chamber 36 to chamber 35, the central section 72 moves downward toward the body 51, and the central section 71 moves upward, away from the body 51. Conversely, the downward force on the central section 71 (when flow through the transfer channel 63 is enabled) pushes the ER fluid 69 from the outer chamber 35, through the transfer channel 63, and into the inner chamber 36. As the ER fluid 69 is transferred from chamber 35 to chamber 36, the central section 71 moves downward toward the body 51, and the central section 72 moves upward, away from the body 51. As will be described in more detail below in connection with Figures 12A-12C, varying the relative heights of central section 71 and central section 72 varies the angle of inclination of top support plate 41 relative to bottom support plate 29.

[0037] The desired length of the transfer channel may be a function of the maximum pressure differential between the chambers of the tilt adjuster during use. The longer the channel, the greater the pressure differential that can be tolerated. The optimal channel length may depend on the application and configuration and, therefore, may vary among various embodiments. A disadvantage of a long channel is that it places a greater restriction on fluid flow when the electric field is removed. In some embodiments, a practical limit on the length of the channel is between 25 mm and 350 mm. In at least some embodiments, the electric field-generating portion 77 may have an L / w ratio of at least 50, where L is the length of the electric field-generating portion 77 and w is the average width of the electric field-generating portion 77. Exemplary minimum values ​​for the L / W ratio of the transfer channel electric field-generating portion in other embodiments include 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, and 170. In some embodiments, the minimum area of ​​each opposing electrode in contact with the ER fluid in the field-generating transfer channel portion can be 800 square millimeters for a transfer channel with an average channel width of 4 mm. As described in more detail below, the electrode mounting features can be enclosed within the channel walls and therefore cannot contact the ER fluid. Therefore, the total area of ​​the electrodes can exceed the exposed functional area.

[0038] As shown in FIGS. 4C and 4D, outer sections 73b and 73c extend upward from top side 52 and connect to inner sections 75b and 75c, which in turn connect to central sections 71b and 71c. Sections 73a, 75a, and 71a of chamber 35a have similar structures. Sections 75 and 71 form recesses in the exterior contour of outer chamber 35. These recesses can reduce the total volume of ER fluid 69 required in the system. In the embodiment of FIGS. 4A-4D, only outer chamber 35 includes an external recess. In other embodiments, any or all of the chambers may include a recess, or none of the chambers may include a recess (e.g., some or all of the outer chambers and / or some or all of the inner chambers may include an external recess, or none of the outer chambers and / or inner chambers may include an external recess).

[0039] In some embodiments, the tilt adjuster chamber can have a bellows shape. For example, as can be seen in FIG. 4C, outer section 73b has folds that define the bellows shape of outer chamber 35b. Side section 74c of wall 54c also has folds that define the bellows shape of inner chamber 36c. In some embodiments of FIGS. 4A-4D, the outer side of the outer chamber has more folds than the sides of the inner chamber. In some embodiments, both chambers can have the same number of folds, while in still other embodiments, the inner chamber can have more folds than the outer chamber. The bellows shape of the chamber facilitates increased flexure during expansion and contraction of the chamber. This helps minimize wear in addition to reducing the total amount of ER fluid required in the system. In some embodiments, some or all of the chambers may not have a bellows shape.

[0040] In some embodiments, tilt adjuster 16 can be fabricated by separately forming a bottom component and a top component. The bottom component can include region 55 of chamber 35, region 56 of chamber 36, the bottom portions of transfer channels 61-65, and the bottom electrode. The top component can include wall 53 of chamber 35, wall 54 of chamber 36, the top portions of transfer channels 61-65, and the top electrode. Once formed, the top side of the bottom component can be bonded to the bottom side of the top component. Thereafter, the interior volume, including the interior volumes of chamber 35, chamber 36, and transfer channels 60-65, can be filled with ER fluid 69, and the interior volume can be sealed.

[0041] 5A-5C illustrate the steps for forming the bottom component of the tilt adjuster 16. First, as shown in FIG. 5A, a first layer 101 is injection molded. Layer 101 will form the bottom layer of the bottom component. The boundary of layer 101 has the same shape as the boundary of body 51, except for extensions 103 and 104. Extensions 103 and 104 will form a neck portion with a sprue through which the tilt adjuster 16 can be filled with ER fluid 69. After filling, the sprues can be sealed and the neck can be removed. Layer 101 is continuous except for opening 78.1, which forms part of a cavity that exposes the electrical leads. An upper surface 105 of layer 101 includes a raised portion 106. Raised portion 106 is provided with a shape that corresponds to and defines a seat for bottom electrode 107.

[0042] The bottom electrode 107, also shown in FIG. 5A, is a solid metal sheet. In some embodiments, the bottom electrode 107 may be formed from 0.05 mm thick, 1010 nickel-plated cold-rolled steel. The electrode 107 includes pads 108 for attaching electrical leads 79 (FIG. 5B). The edges of the electrode 107 include a series of slots 109 formed along both edges. Exemplary dimensions of the slots 109 are 0.5 mm by 1 mm. As described in further detail below, material may flow into the slots 109 during molding of the bottom component to secure the electrode 107 in place.

[0043] 5B, electrode 107 is attached to raised portion 106. In some embodiments, a pressure sensitive adhesive (PSA) may be applied to the bottom surface of electrode 107 and / or the top surface of raised portion 106 to hold electrode 107 in place during subsequent molding operations (described below). Lead 79 may be put in place and attached to pad 108 by soldering, using conductive epoxy, or other techniques.

[0044] After attachment of electrode 107 and lead 79, second layer 112 is overmolded onto layer 101. The resulting bottom component 115 of tilt adjuster 16 is shown in FIG. 5C. Region 55 of chamber 35 and region 56 of chamber 36 are defined in top surface 116 of bottom component 115. Bottom portions 61.1, 62.1, 63.1, 64.1, and 65.1 of transmission channels 61, 62, 63, 64, and 65, respectively, are similarly formed in top surface 116. A portion of electrode 107 is exposed within bottom portion 63.1. Opening 78.2 in layer 112, aligned with opening 78.1 in layer 101, will form an additional cavity for housing electrical lead 79 and a similar electrical lead for the upper electrode (described below). Layer 112 also includes extensions 113 and 114 that overlay extensions 103 and 104 of layer 101. Channel 129 in extension 113 will form a portion of the outer gate. Channel 110 in extension 114 will form a portion of the inner gate. Raised areas 119 extending from top surface 116 over leads 53 will fit into recesses in the bottom surface of the upper component of tilt adjuster 16. Recesses 120 are formed in top surface 116 to receive corresponding raised areas on the bottom surface of the upper component that correspond to the leads described below.

[0045] In some embodiments, layer 101 may be injection molded from thermoplastic polyurethane (TPU). Layer 112 may be overmolded onto layer 101 (with electrodes 107 and leads 79 attached). Layer 112 may be formed from the same type of TPU used to form layer 101.

[0046] 6A-6C illustrate steps for forming the upper component of the tilt adjuster 16. First, as shown in FIG. 6A, a first layer 151 is injection molded. Layer 151 will form the top layer of the upper component. The boundary of layer 151 has the same shape as the boundary of body 51, except for extensions 153 and 154. Layer 151 is continuous. An upper surface 155 of layer 151 includes a raised portion 156. Raised portion 156 is shaped to accommodate and define a seat for upper electrode 157. As can be seen in FIG. 6A, layer 151 includes opposing walls 53 and 54, which are joined around their edges to the rest of layer 151. In some embodiments, walls 53 and 54 are injection molded simultaneously with the rest of layer 151. In other embodiments, such as those described below in connection with Figures 14C-16F, the walls of the chambers may be molded separately, and then the remainder of layer 151 may be molded to those walls.

[0047] In Figure 6A, layer 151 has been inverted from the orientation of tilt adjuster 16 in Figure 4A. In particular, the bottom side of layer 151 is visible in Figure 6A. The portion of the top side of layer 151 surrounding walls 53 and 54, which is not visible in Figure 6A, will form the upper portion 52 of body 51 in the finished tilt adjuster 16. Extensions 153 and 154 will form the neck portion having a sprue through which tilt adjuster 16 can be filled with ER fluid 69.

[0048] 6A. Electrode 157 is also a solid metal sheet and may be formed from the same material used to form electrode 107. Electrode 157 includes pads 158 for attaching electrical leads. The edges of electrode 157 include a series of slots 159 formed along both edges. Exemplary dimensions of slots 159 may be the same as the dimensions of slots 109 in electrode 107.

[0049] Electrode 157 is attached to raised portion 156 in FIG. 6B. In some embodiments, a PSA may be applied to the top surface of electrode 157 and / or the bottom surface of raised portion 156 to hold electrode 157 in place during subsequent molding operations (described below). Lead 80 may be put in place and attached to pad 158 by soldering, using conductive epoxy, or other techniques.

[0050] After attachment of electrode 157 and lead 80, second layer 162 is overmolded onto layer 151. The resulting top component 165 of tilt adjuster 16 is shown in FIG. 6C. Openings to the interior region of chamber 35 in wall 53 and to the interior region of chamber 36 in wall 54 are defined in bottom surface 166 of top component 165. Upper portions 61.2, 62.2, 63.2, 64.2, and 65.2 of transmission channels 61, 62, 63, 64, and 65, respectively, are also formed in bottom surface 166. A portion of electrode 157 is exposed in upper portion 63.2. Recess 78.3 in surface 166 aligns with openings 78.1 and 78.2 to form cavities exposing leads 79 and 80. Layer 162 also includes extensions 163 and 164 that overlie extensions 153 and 154 of layer 151. Channel 179 in extension 163 will form a portion of the outer gate. Channel 160 in extension 164 will form a portion of the inner gate. Raised region 169 extending from bottom surface 166 over leads 80 will fit within recess 120 in top surface 116 of bottom component 115. Bottom surface 166 has recess 170 formed therein that receives raised region 119 on top surface 116 of bottom component 115.

[0051] In some embodiments, layer 151 may be injection molded from TPU. Layer 162 may be overmolded onto layer 151 (with electrodes 157 and leads 80 attached) by injection molding additional TPU. Layers 151 and 162 may be formed from the same type of TPU used to form layers 101 and 112, or may be formed from a different type of TPU.

[0052] 7 shows the assembly of the tilt adjuster 16 after the bottom component 115 and the top component 116 have been fabricated. The bottom surface 166 of the top component 165 is positioned to contact the top surface 116 of the bottom component 115. Components 115 and 165 are assembled such that bottom portions 61.1-65.1 are aligned with top portions 61.2-65.2, respectively, to form transfer channels 61-65, regions 55a-55c are aligned with openings to the interior of the cavities bounded by walls 53a-53c, respectively, to form outer chambers 35a-35c, regions 56a-56c are aligned with openings to the interior of the cavities bounded by walls 54a-54c, respectively, to form inner chambers 36a-36c, raised region 119 is positioned within recess 170, and raised region 169 is positioned within recess 120. The bottom surface 166 of the top component 115 may be joined to the top surface 116 of the bottom component 165 by RF welding. In some embodiments, the surfaces 166 and 116 may be joined using an application of a bonding agent.

[0053] 8A is an exterior top perspective view of tilt adjuster 16 after joining components 115 and 165, but before filling tilt adjuster 16 with ER fluid 69. For illustrative purposes, the locations of layers 101, 112, 151, and 162 are shown in the enlarged inset of FIG. 8A. However, in at least some embodiments (e.g., when the same material with the same color is used for all layers), the individual layers may be indistinguishable within tilt adjuster 16.

[0054] Neck 193 is formed by extensions 103 and 113 of layers 101 and 112, respectively, as well as extensions 153 and 163 of layers 151 and 162, respectively. Gate 191, formed by channels 129 and 179, provides a passageway into outer chamber 35a. Neck 194 is formed by extensions 104 and 114 of layers 101 and 112, respectively, as well as extensions 154 and 164 of layers 151 and 162, respectively. Gate 192, formed by channels 110 and 160, provides a passageway into inner chamber 36a. In FIG. 8A , gates 191 and 192 are shown with dashed lines, but for simplicity, the location of the transfer channel and other internal structure of tilt adjuster 116 are not shown. ER fluid 69 can then be poured through one of gates 191 or 192 until it flows out the other of gates 191 or 192. In some embodiments, degassing procedures such as those described in U.S. Patent Application Publication No. 2017 / 0150785 (incorporated herein by reference) may be used. In some embodiments, degassing procedures such as those described in U.S. Provisional Patent Application entitled "Degassing Electrorheological Fluid" (filed on the same day as this application and having attorney docket number 215127.02298 / 170259US04) (incorporated herein by reference) may be used. After filling and degassing, sprues 191 and 192 may be sealed (e.g., by RF welding across sprues 191 and 192), thereby sealing the interior volumes formed by chambers 35a-35c, chambers 36a-36c, and the interior volumes of transfer channels 61-65. Portions of forward necks 193 and 194 of the seals may then be trimmed to achieve the perimeter shape of the forefoot portion of tilt adjuster 16 shown in FIG. 4B.

[0055] 8B is a bottom perspective view of the inside of tilt adjuster 16 after assembly and before filling with ER fluid. Bottom cavity 78 is formed by the alignment of recess 78.3 (layer 162, FIG. 6C) with openings 78.2 (layer 112, FIG. 5C) and 78.1 (layer 101, FIG. 5A). Leads 79 and 80 are exposed within cavity 78 for connection to converter 45.

[0056] FIG. 9 is an enlarged cross-sectional view taken along arrow CC in the plane shown in FIG. 4B. FIG. 9 shows further detail of embedded electrodes 107 and 157, as well as a portion of delivery channel 63 located within field-generating portion 77. The locations of layers 101, 112, 151, and 162 are indicated by dashed lines. Bottom electrode 107 straddles the bottom of delivery channel 63 within field-generating portion 77. Top electrode 157 straddles the top of delivery channel 63 within field-generating portion 77. The side edges of electrodes 107 and 157 extend beyond the sides of delivery channel 63 and into the material of body 51. As can be seen in FIG. 9, the material of body 51 flows into slots 109 and 159 and solidifies within slots 109 and 159, securing electrodes 107 and 157 in place. In some embodiments, delivery channel 63 can have a maximum height (h) between electrodes of 1 millimeter (mm) and an average width (w) of 2 mm. The maximum height h (between the top and bottom walls) and average width w of the transmission channels 61, 62, 64, and 65 may have the same dimensions.

[0057] Figure 10 is a top rear interior perspective view, partially schematic, in cross section, taken along arrow AA in the plane shown in Figure 4B. Chamber cap 38c is in place over chamber 36c, and chamber cap 37b is in place over chamber 35b. Chamber cap 38c includes a recess 98c that receives a disk-shaped portion on the upper exterior of wall 54c. Chamber cap 37b includes a protrusion 97b that fits within an exterior recess on the top of chamber 35b and a skirt 95b that surrounds outer sidewall 73b.

[0058] Each of chamber caps 38a and 38b has a similar structure to chamber cap 38c. Each of chamber caps 37a and 37c has a similar structure to chamber cap 37b. For convenience, other chamber caps are omitted from Figure 10, but in assembled shoe 10, chamber caps 38a and 38b are positioned over chambers 36a and 36b, respectively, in a manner similar to chamber cap 38c and chamber 36c, and chamber caps 35a and 35c are positioned over chambers 35a and 35c, respectively, in a manner similar to chamber caps 37b and chamber 35b.

[0059] The top surfaces of chamber caps 37a-37c and 38a-38c, including top surface 94c of chamber cap 38c and top surface 93b of chamber cap 37b, have rounded, convex shapes. These shapes facilitate movement of the chamber caps across the bottom surface of upper support plate 41 and also provide a camming action against plate 41. In some embodiments, at least top surfaces 93 and 94 of chamber caps 37 and 38 are formed from a material that has a coefficient of friction with the bottom surface of support plate 41 that is less than the coefficient of friction with the bottom surface of support plate 41 of the material forming walls 53 and 54. In some embodiments, caps 37 and 38 may be formed from polycarbonate (PC), a blend of PC and acrylonitrile butadiene styrene (ABS), or an acetal homopolymer.

[0060] FIG. 11 is a block diagram illustrating the components of the electrical system of shoe 10. Individual lines to and from the blocks in FIG. 11 represent signal (e.g., data and / or power) flow paths and are not necessarily intended to represent individual electrical conductors. Battery pack 13 includes a rechargeable lithium-ion battery 201, a battery connector 202, and a lithium-ion battery protection IC (integrated circuit) 203. Protection IC 203 detects abnormal charging and discharging conditions, controls charging of battery 201, and performs other conventional battery protection circuit operations. Battery pack 13 also includes a USB (universal serial bus) port 208 for communicating with controller 47 and for charging battery 201. Power path control unit 209 controls whether power is supplied to controller 47 from USB port 208 or battery 201. On / off (O / O) button 206 activates or deactivates controller 47 and battery pack 13. LED (light-emitting diode) 207 indicates whether the electrical system is on or off. The above-described individual elements of battery pack 13 may be conventional or may be commercially available components that are combined and used in the novel and inventive manner described herein.

[0061] The controller 47 includes the converter 45 as well as the components housed on the PCB 46. In other embodiments, the components of the PCB 46 and the converter 45 may be included on a single PCB or packaged in some other manner. The controller 47 includes a processor 210, a memory 211, an inertial measurement unit (IMU) 213, and a low-energy wireless communication module 212 (e.g., a BLUETOOTH® communication module). The memory 211 stores instructions that can be executed by the processor 210 and may store other data. The processor 210 executes instructions stored by and / or in the memory 211, which cause the controller 47 to operate as described herein. As used herein, instructions may include hard-coded instructions and / or programmable instructions.

[0062] IMU 213 may include a gyroscope and an accelerometer and / or magnetometer. Data output by IMU 213 may be used by processor 210 to detect changes in orientation and motion of shoe 10, and therefore of a foot wearing shoe 10. As explained in more detail below, processor 210 may use such information to determine when the tilt of a portion of shoe 10 should change. Wireless communication module 212 may include an ASIC (application-specific integrated circuit) and may be used to communicate programming and other instructions to processor 210, as well as download data that may be stored by memory 211 or processor 210.

[0063] The controller 47 includes a low dropout voltage regulator (LDO) 214 and a boost regulator / converter 215. The LDO 214 receives power from the battery pack 13 and outputs a constant voltage to the processor 210, memory 211, wireless communication module 212, and IMU 213. The boost regulator / converter 215 boosts the voltage from the battery pack 13 to a level (e.g., 5 volts) that provides an acceptable input voltage for the converter 45. The converter 45 then increases that voltage to a much higher level (e.g., 5000 volts) and supplies that high voltage across the electrodes 107 and 157 of the tilt adjuster 16. The boost regulator / converter 215 and the converter 45 are enabled / disabled by signals from the processor 210. The controller 47 also receives signals from the outer FSRs 31a-31c and inner FSRs 32a-32c. Based on these signals from FSRs 31 and 32, processor 210 determines whether forces from the wearer's foot onto outer fluid chamber 35 and inner fluid chamber 36 are creating a pressure in chamber 35 that is higher than the pressure in chamber 36.

[0064] The above-described individual elements of controller 47 may be conventional or may be commercially available components that are combined and used in the novel and inventive manners described herein. Moreover, controller 47 is physically configured, via instructions stored in memory 211 and / or processor 210, to perform the novel and inventive operations described herein related to controlling the communication of fluid between chambers 35 and 36 to adjust the cant of the forefoot portion of midsole 14 of shoe 10.

[0065] 12A-12C are partial schematic cross-sectional views illustrating the operation of tilt adjuster 16 as it moves from a minimum tilt state to a maximum tilt state, according to some embodiments. The location of the cross-sectional plane through tilt adjuster 16 in FIGS. 12A-12C is similar to the location indicated by arrow AA in FIG. 4B. The relative positions of bottom support plate 29, FSRs 32c and 31b, and top support plate 41 in a similar cross-section of assembled shoe 10 are also shown. None of these drawings are necessarily to scale, and the proportions of certain elements depicted in FIGS. 12A-12C have been altered relative to the proportions set forth in other figures for clarity.

[0066] In the minimum tilt state, the tilt angle α of the top plate 41 relative to the bottom plate 29 is a value α , which represents the minimum amount of tilt that the sole structure 12 is configured to provide in the forefoot region. min In some embodiments, α min = 0°. In the maximum tilt state, the tilt angle α has a value α ≈ 0°, which represents the maximum amount of tilt that the sole structure 12 is configured to provide. max In some embodiments, α max is at least 5°. In some embodiments, α max = 10°. In some embodiments, α max may be greater than 10°.

[0067] 12A-12C show bottom plate 29, tilt adjuster 16, top plate 41, FSR 31b, and FSR 32c, while other elements are omitted for clarity. Top plate 41 and other elements of sole structure 12 are configured such that a downward force on plate 41 toward tilt adjuster 16 is supported by inner chamber 36 and outer chamber 35. Outer stop 83 and inner stop 82 are also shown in FIGS. 12A-12C. Inner stop 83 supports the inner side of top plate 41 when tilt adjuster 16 and top plate 41 are in their maximum tilt position. Outer stop 82 supports the outer side of top plate 41 when tilt adjuster 16 and top plate 41 are in their minimum tilt position. Outer stop 82 prevents top plate 41 from tilting outward. Because runners move counterclockwise around the track during a race, the wearer of shoe 10 will likely be turning to his or her left as the track curves. In such a use scenario, the midsole of the right shoe's sole structure need not be angled outward. However, in other embodiments, the sole structure may be angled either inward or outward.

[0068] In some embodiments, the left shoe of a pair of shoes that includes shoe 10 may be configured slightly differently than that shown in Figures 12A-12C. For example, the medial stop may be at a similar height to the lateral stop 82 of shoe 10, and the lateral stop may be at a similar height to the medial stop 83 of shoe 10. In some such embodiments, the top plate of the left shoe moves between a minimum tilt state, in which the top plate is tilted outward, and a maximum tilt state (i.e., the lateral side of the left shoe's top plate will be lower than the medial side of the left shoe's top plate at maximum tilt).

[0069] The locations of inner stop 83 and outer stop 82 are represented schematically in Figures 12A-12C but are not shown in the previous figures. In some embodiments, outer stop 82 may be formed as a rim on the outside or edge of bottom plate 29. Similarly, inner stop 83 may be formed as a rim on the inside or edge of bottom plate 29.

[0070] FIG. 12A shows the tilt adjuster 16 when the top plate 41 is in its minimum tilt state. The shoe 10 can be configured to place the top plate 41 in its minimum tilt state when the wearer of the shoe 10 is standing or in the starting blocks immediately prior to the start of a race, or when the wearer is running on a straight section of the track. In FIG. 12A , the controller 47 maintains the voltage across the electrodes 107 and 157 at one or more flow-blocking voltage levels sufficient to generate an electric field having sufficient strength to increase the viscosity of the ER fluid 69 in the electric field-generating portion 77 of the transfer channel 63 to a viscosity level that prevents flow between the chambers 35c and 36c. In some embodiments, the flow-blocking voltage level is sufficient to generate an electric field strength between the electrodes 107 and 157 of 3 kV / mm to 6 kV / mm. Because ER fluid 69 cannot flow through channel 63 under the conditions shown in FIG. 12A, the tilt angle α of upper plate 41 does not change when the wearer of shoe 10 shifts their weight between the inside and outside of shoe 10.

[0071] FIG. 12B shows that the controller 47 determines that the top plate 41 should be placed in the maximum tilt state, i.e., α=α max 1 shows the tilt adjuster 16 immediately after determining that the upper plate 41 should be tilted to α. In some embodiments, as described below, the controller 47 makes such a determination based on a significant number of steps taken by the wearer of the shoe 10. maxIf the controller 47 determines that the foot wearing the shoe 10 is in a portion of the wearer's gait cycle where the shoe 10 is in contact with the ground, the controller 47 determines whether the pressure P of the ER fluid 69 in the inner chamber 36 is M and the pressure P of the ER fluid 69 in the outer chamber 35 L Difference △P M-L is positive, i.e., P M -P L It is also determined whether or not is greater than zero. M-L is positive, controller 47 reduces the voltage across electrodes 107 and 157 to a flow-enabling voltage level. In particular, the voltage across electrodes 107 and 157 is reduced to a level low enough to reduce the electric field strength within delivery channel 63 such that the viscosity of ER fluid 69 within delivery channel 63 is at a normal viscosity level.

[0072] When the voltage across electrodes 107 and 157 is reduced to a flow-enabling voltage level, the viscosity of ER fluid 69 in channel 63 decreases. ER fluid 69 then begins to flow from chamber 35 into chamber 36. This causes the inside of top plate 41 to begin moving toward bottom plate 29 and the outside of top plate 41 to begin moving away from bottom plate 29. As a result, tilt angle α becomes equal to α min starts to increase from

[0073] In some embodiments, controller 47 determines whether shoe 10 is in the stride portion of a gait cycle or in contact with the ground based on data from IMU 213. In particular, IMU 213 may include a three-axis accelerometer and a three-axis gyroscope. Using data from the accelerometer and gyroscope, and based on known biomechanics of a runner's foot, such as rotations and accelerations in various directions during various portions of a gait cycle, controller 47 can determine whether the right foot of a wearer of shoe 10 is striking the ground. Controller 47 calculates ΔP based on signals from FSRs 31a-31c and FSRs 32a-32c. M-LEach of these signals corresponds to the magnitude of the force exerted by the wearer's foot pressing down on the FSR. Based on the magnitude of these forces and the known dimensions of chambers 35 and 36, controller 47 can calculate the values ​​of the signals from FSR 31 and FSR 32 as ΔP M-L In some embodiments, the sum of the inner FSRs 31 can be correlated to the magnitude and sign of the inner pressure P M The sum of the outer FSR32 is used as the value of the outer pressure P L The pressure difference is then calculated to determine the voltage state of the electrodes.

[0074] Figure 12C shows the tilt adjuster 16 shortly after the time associated with Figure 12B. In Figure 7C, the top plate 41 has reached its maximum tilt state. In particular, the tilt angle α of the top plate 41 is α max The inner stopper 83 prevents the inclination angle α from reaching α max 7C has elapsed, controller 47 increases the voltage across electrodes 107 and 157 to the flow-blocking voltage level. This prevents further flow through transmission channel 63 and holds top plate 41 in the maximum tilt state. During a normal gait cycle, the downward force on the right foot on the shoe is initially higher on the lateral side as the forefoot rolls inward. If flow through channel 63 were not prevented, the initial downward force on the lateral side of the wearer's right foot would decrease the tilt angle α.

[0075] In some embodiments, the wearer of shoe 10 may need to take several steps for top plate 41 to reach maximum tilt. Thus, once controller 47 determines (based on data from IMU 213 and FSRs 31 and 32) that the wearer's foot has left the ground, controller 47 may be configured to increase the voltage across electrodes 107 and 157. Controller 47 then determines when shoe 10 strikes the ground and ΔP M-LIf it is again determined to be positive, the voltage may be decreased. This may be repeated for a predetermined number of steps. This is done to determine the medial-lateral pressure differential ΔP at various times during the transition from the minimum to maximum incline condition. M-L , shown in FIG. 13A as a graph of the voltage across electrodes 107 and 157, and the tilt angle α.

[0076] At time T1, the controller 47 determines that the upper plate 41 of the shoe 10 should transition to the maximum tilt state. At time T2, the controller 47 determines that the shoe 10 is on the ground but ΔP M-L At time T3, the controller 47 determines that the shoe 10 is on the ground and ΔP M-L is determined to be positive, the controller reduces the voltage across electrodes 107 and 157 to a voltage level that allows flow. As a result, the tilt angle α of top plate 41 is reduced to α min At time T4, controller 47 determines that shoe 10 is no longer touching the ground, and the controller increases the voltage across electrodes 107 and 157 to the flow blocking voltage level, so that tilt angle α is maintained at its current value. At time T5, controller 47 again determines that shoe 10 is touching the ground, but ΔP M-L At time T6, the controller 47 determines that the shoe 10 is on the ground and ΔP M-L is determined to be positive, and controller 47 again reduces the voltage across electrodes 107 and 157 to a flow-enabling voltage level, and the increase in tilt angle α resumes. At time T7, tilt angle α reaches α max . The increase in tilt angle α stops because further tilt of top plate 41 is prevented by inner stop 83. At time T8, controller 47 determines that shoe 10 is no longer on the ground, and controller 47 again increases the voltage between electrode 107 and electrode 157 to the flow-blocking voltage level. Controller 47 maintains the voltage at the flow-blocking voltage level for another step cycle until controller 47 determines that top plate 41 should transition to the minimum tilt state.

[0077] FIG. 13B shows the medial-lateral pressure difference ΔP at various times during the transition from the maximum tilt condition to the minimum tilt condition. M-L , the voltage across electrodes 107 and 157, and the tilt angle α. At time T11, the controller 47 determines that the top plate 47 of the shoe 10 should transition to a minimum tilt state. At time T12, the controller 47 determines that the shoe 10 is striking the ground and ΔP M-L is determined to be negative, and controller 47 reduces the voltage across electrodes 107 and 157 to a voltage level that allows flow. M-L is the pressure P in the inner chamber 36 med The pressure P in the outer chamber 35 compared to lat Since the angle α is high, the ER fluid 59 starts to flow from the outer chamber 35 into the inner chamber 36, and the angle α is max At time T13, the controller 47 detects that the shoe 10 is on the ground, but ΔP M-L is determined to be positive, and controller 47 increases the voltage across electrodes 107 and 157 to the flow blocking voltage level. As a result, the tilt angle α of top plate 41 is maintained. At time T14, controller 47 determines that shoe 10 is again striking the ground and ΔP M-L is negative, and controller 47 reduces the voltage across electrodes 107 and 157 to a flow-enabling voltage level. As a result, tilt angle α continues to decrease. At time T15, tilt angle α decreases to α min The decrease in tilt angle α stops because further tilting of top plate 41 is prevented by outer stop 82. At time T16, controller 47 calculates ΔP M-L is determined to be positive, and controller 47 again increases the voltage across electrodes 107 and 157 to the flow-blocking voltage level. Controller 47 maintains the voltage at the flow-blocking voltage level for additional step cycles until controller 47 determines that top plate 41 should transition to the maximum tilt state.

[0078] In the above example, controller 47 reduced the voltage across electrodes 107 and 157 for two step cycles to transition between tilt states. However, in other embodiments, controller 47 may reduce the voltage for fewer or more step cycles. The number of step cycles to transition from minimum tilt to maximum tilt need not be the same as the number of step cycles to transition from maximum tilt to minimum tilt.

[0079] In some embodiments, controller 47 counts the number of steps taken since initialization and determines when to transition to the maximum incline position by determining whether the number of steps is sufficient to position the wearer of shoe 10 at a portion of a track corner. Typically, track and field athletes have very consistent stride lengths. The dimensions of the track and the distance from the starting line to the corner of each track lane are known quantities that can be stored by controller 47. Based on input from the wearer of shoe 10 to controller 47 indicating the wearer's stride length as well as the track lane assigned to the wearer of shoe 10, controller 47 can determine the wearer's position on the track by storing the number of steps taken during running. As described above, controller 47 can determine when shoe 10 may be in a gait cycle based on data from IMU 213. These gait cycle determinations can indicate when a step has been taken.

[0080] In some embodiments, the left shoe of a pair of shoes that includes shoe 10 may operate in a similar manner as described above for shoe 10, except that the maximum tilt state represents the top plate of the left shoe being tilted outward to the maximum. The operations performed by the controller of the left shoe are similar to those described above in connection with FIGS. 13A and 13B, except that the determination of ΔP L-M =P L -P M Instead of being based on the sign of △P M-L was based on the sign of P L is the pressure in the outer fluid chamber of the left shoe, and P Mis the pressure in the inner fluid chamber of the left shoe.

[0081] In some embodiments, the shoe controller may determine when to transition from minimum to maximum tilt and vice versa based on other types of input. In some such embodiments, for example, the shoe wearer may wear clothing including one or more IMUs positioned at some other location away from the shoe and / or on the wearer's torso. The outputs of those sensors may be communicated to the shoe controller via a wireless interface similar to wireless module 212 (FIG. 11). Upon receiving an output from those sensors indicating that the wearer has assumed a body position consistent with the need to tilt the shoe's upper plate (e.g., as the wearer's body leans to the side while running around a corner on a track), the controller can take action to tilt the shoe's upper plate. In still other embodiments, the shoe controller may determine position in some other manner (e.g., based on a GPS signal).

[0082] The controller does not have to be located within the sole structure. For example, in some embodiments, some or all components of the controller may be located with the housing of a battery assembly, such as battery assembly 13, and / or may be located in a separate housing positioned on the upper of the footwear.

[0083] In some embodiments, as described above, bottom component 115 and top component 165 may each be formed during a multi-shot injection molding process. This process is shown schematically in FIGS. 14A and 14B. In a first set of operations to form layers 101 and 151 shown in FIG. 14A, bottom molds 301 and 302 and a first set of top molds 303 and 304 are used. A surface on bottom mold 301 has a contour that corresponds to the underside of the bottom surface and side edges of layer 101 and forms the bottom surface and side edges of layer 101. A surface on top mold 303 has a contour that corresponds to the underside of the top surface of layer 101 and forms the top surface of layer 101. In operation (1a), molds 301 and 303 are brought together. In operation (2a), molten TPU (or other material) is injected, and the material hardens into layer 101. In operation (3a), mold 303 is removed, leaving layer 101 in mold 301, and electrodes 107 and leads 79 are placed on layer 101. A surface on bottom mold 302 has contours that correspond to and form the underside of the top surface and side edges of layer 151. A surface on top mold 304 has contours that correspond to and form the underside of the bottom surface of layer 151. In operation (1b), molds 302 and 304 are brought together. In operation (2b), molten TPU (or other material) is injected, and the material hardens to form layer 151. In operation (3b), mold 304 is removed, leaving layer 151 in mold 302, and electrodes 157 and leads 80 are placed on layer 151.

[0084] In a second set of operations to form layers 112 and 162, shown in FIG. 14B , bottom molds 301 and 302 and a second set of top molds 305 and 306 are used. A surface on bottom mold 301 has a contour that corresponds to the underside of the side edge of layer 112 and forms the side edge of layer 112. A surface on top mold 305 has a contour that corresponds to the underside of the top surface of layer 112 and forms the top surface of layer 112. In operation (4a), molds 301 and 305 are brought together. In operation (5a), molten TPU (or other material) is injected, and the material hardens into layer 112. In operation (6a), mold 305 is removed, and component 115 is removed from mold 301. A surface on bottom mold 302 has a contour that corresponds to the underside of the side edge of layer 162 and forms the side edge of layer 162. The surface on top of upper mold 306 has a contour that corresponds to the underside of the bottom surface of and forms the bottom surface of layer 162. In operation (4b), molds 302 and 306 are brought together. In operation (5b), molten TPU (or other material) is injected, which hardens into layer 162. In operation (6b), mold 306 is removed and component 165 is removed from mold 302.

[0085] In some embodiments, walls 53 and 54 of chamber 35 and chamber 36 are molded simultaneously with the rest of layer 151. In particular, mold 302 may include contoured areas corresponding to the backsides of the outer surfaces of walls 53 and 54, and mold 304 may include contoured areas corresponding to the backsides of the inner surfaces of walls 53 and 54. In other embodiments, walls 53 and 54 are molded separately. These walls are then inserted into a bottom mold, a top mold is placed over the bottom mold, and the remainder of layer 151 is injection molded into place around walls 53 and 54. In some such embodiments, the bottom and top molds may have removable inserts positioned to hold walls 53 and 54. These inserts may then be replaced with other inserts to form versions of layer 151 having various chamber wall sizes and / or shapes.

[0086] 14C is a top view of mold 312 that can be used to form layer 151, according to some embodiments. Mold 312 replaces mold 302. Mold 312 includes a contoured bottom surface 320 that corresponds to the underside of and forms the top surface of layer 151. Sidewalls 322 correspond to the underside of and form the side edges of layers 151 and 162. Inserts 323a-323c correspond to walls 53a-53c, respectively. Each of inserts 323 has inner surfaces 325a, 325b, and 325c that contact the outer surface of wall 53 to help hold wall 53 in place during injection molding. Inserts 324a-324c correspond to walls 54a-54c, respectively. Each of the inserts 324 has an inner surface 326a, 325b, and 325c that contacts the outer surface of the wall 54 to help hold the wall 54 in place during injection molding.

[0087] 14D is a top view of mold 312 with inserts 323 and 324 removed. As described in further detail below, any or all of inserts 323 and / or any or all of inserts 324 can be replaced with inserts corresponding to different types of chamber walls, thereby allowing mold 312 to be used to create customized versions of the tilt adjuster upper component. Aperture 327a corresponds to insert 323a and includes lip 329a. Apertures 327b and 327c, corresponding to inserts 327b and 327c, respectively, include lips 329a and 329b. Apertures 328a-328c correspond to inserts 324a-324c, respectively, and include respective lips 330a-330c. Lips 329 and 330a help retain inserts 323 and 324, as described in further detail below.

[0088] Figures 15A-15F are partial schematic cross-sectional views illustrating the molding of a portion of component 165 using mold 312. The cut plane in Figure 15A is a vertical plane through the center of wall 53a. The cut plane in Figures 15B-15E is indicated by arrow DD in Figure 14C. The cut plane in Figure 15F is through a portion of component 165 corresponding to the area of ​​mold 312 indicated by arrow DD.

[0089] 15A-15F correspond to molding the region of component 165 that surrounds and incorporates wall 53a. However, one of ordinary skill in the art, based on the description herein, will readily understand the construction and use of other mold elements to simultaneously mold portions of mold element 165 that surround and incorporate other walls 53 and 54.

[0090] FIG. 15A is a cross-sectional view of separately molded wall 53a. FIG. 15B is a cross-sectional view of wall 53a after it has been placed within insert 323a. Upper mold 314 replaces mold 304 (FIG. 14A) and is placed over mold 312. Like mold 312, mold 314 includes multiple inserts, each corresponding to one wall 53 or one wall 54. Insert 397a shown in FIG. 15B corresponds to wall 53a. The other inserts correspond to walls 53b, 53c, and 54a-54c. Surface 395 surrounding insert 397a, as well as the inserts corresponding to the other walls 53 and 54, have contours that correspond to the underside of and form the bottom surface of layer 151 (e.g., including raised region 156). Lip 331a of insert 323a abuts lip 329a of opening 327a to secure insert 323a in place against outward pressure from the poured molten material. Similarly, insert 397a includes a lip that abuts a lip in the opening of mold 314 to secure insert 323a in place against outward pressure from the poured molten material. The other inserts in molds 312 and 314 are secured in a similar manner.

[0091] Molds 312 and 314 are joined to define cavity 400 into which molten material is poured. Face 325a of insert 323a contacts the outer surface of wall 53a. The outer portion of protrusion 393a in insert 397a contacts the inner surface of wall 53a. Wall 53a is thus sandwiched between inserts 323a and 325a, sealing cavity 400 around wall 53a. Cavity 400 is similarly sealed around the other walls 53 and 54.

[0092] FIG. 15C shows molds 312 and 314 after molten material has been poured into cavity 400. The molten material fuses with wall 53a and solidifies to form layer 151. In FIG. 15D, mold 314 has been removed, leaving layer 151 in mold 312. Electrode 157 and lead 80 are positioned on layer 151 (not shown). A second mold 316 is used in place of mold 306 (FIG. 14B) and is positioned over mold 312. Molds 316 and 312 define cavity 402 into which molten material will be poured to form layer 162 when combined with layer 151, electrode 157, and lead 80 in mold 312. Mold 316 includes insert 391a corresponding to wall 53a and other inserts corresponding to walls 53b, 53c, and 54a-54c. The insert in mold 316 is also removable and held in place with an abutting lip in a manner similar to that described above. Surface 387 surrounding the insert in mold 316 corresponds to the underside of the bottom surface of layer 162 (e.g., including transmission channel portions 61.2-65.2) and has a contour that forms the bottom surface of layer 162. Protrusion 389a of insert 391a abuts and sandwiches wall 53a against insert 323a, sealing void 402 around wall 53a. void 402 is similarly sealed around the other walls 53 and 54.

[0093] Figure 15E shows molds 312 and 316 after pouring molten material into cavity 402. The molten material has fused with wall 53a and layer 151 and solidified to form layer 162 and component 165. Figure 15F shows the area of ​​component 165 around wall 53a after removal from mold 312.

[0094] Figures 16A-16F illustrate how molds 312, 314, and 316 are used to form customized tilt adjuster components. While Figures 16A-16F show an example in which wall 53a has been replaced with another wall, some or all of the other chamber walls could be replaced in addition or alternatively.

[0095] FIG. 16A is a cross-sectional view of wall 553a used in place of wall 53a in the tilt adjuster. The cut plane is perpendicular through the diameter of wall 553a. The cut planes in FIGS. 16B-16F are from a similar location to the cut planes described in FIGS. 15B-15F. In FIG. 16B, wall 553a is placed in molds 312 and 314. Inserts 323a and 397a are replaced with inserts 343a and 417a, respectively, that match wall 553a. In FIG. 16C, molten material is poured to form layer 151. In FIG. 16D, mold 314 is removed and replaced with mold 316, which has insert 411a (matching wall 553a) instead of insert 391a. Electrode 157 and lead 80 were placed on layer 151 after mold 314 was removed and before mold 316 was placed. In Figure 16E, molten material has been injected to form layer 162 and component 165. Figure 16F shows the region of component 165 around wall 553a after removal from mold 312.

[0096] For the avoidance of doubt, this application includes subject matter set forth in the following numbered paragraphs ("Para."): 1. An article of footwear comprising: an upper; and a sole structure coupled to the upper, the sole structure comprising a base, a tilt adjuster, and a support plate; the base is disposed in a forefoot portion of the sole structure, a midfoot portion of the sole structure, and a heel portion of the sole structure; the support plate is disposed in at least the forefoot portion of the sole structure; the tilt adjuster comprises a tilt adjuster forefoot section disposed in the forefoot portion of the sole structure between the base and the support plate; the tilt adjuster forefoot section comprises at least three chambers, each containing an electrorheological fluid and configured to vary outward extension in response to changes in volume of the electrorheological fluid in the chamber; the chambers are connected in series by transmission channels, each transmission channel permitting flow between two of the chambers; the transmission channels comprise a flow-regulating transmission channel, the flow-regulating transmission channel comprising opposing first and second electrodes extending along an interior of an electric field-generating portion of the flow-regulating transmission channel. 2. The footwear article of paragraph 1, wherein the first chamber in the series of chambers is not connected to the last chamber in the series of chambers. 3. An article of footwear described in either paragraph 1 or 2, wherein each of the chambers includes a flexible wall forming a portion of the chamber, the flexible wall configured to expand as the volume of the electrorheological fluid in the chamber increases and to contract as the volume of the electrorheological fluid in the chamber decreases. 4. The footwear article described in paragraph 3, wherein the tilt adjuster comprises a body through which the transmission channel is housed and through which the flexible wall of the chamber extends. 5. An article of footwear as described in paragraph 3, wherein the flexible wall of one of the chambers comprises a central section and a side section surrounding the central section, the side section comprising at least one fold that defines the accordion shape of the chamber. 6. An article of footwear as described in paragraph 3, wherein the flexible wall comprises a central section and side sections surrounding the central section, the side sections comprising at least one fold that defines the bellows shape of the chamber. 7. An article of footwear described in any of paragraphs 3, 5, or 6, wherein the flexible wall of one of the chambers comprises a central section and side sections surrounding the central section, the central section having an outer shape including a recess. 8. An article of footwear described in any of paragraphs 3, 5, or 6, wherein for each of at least two of the chambers, the flexible wall comprises a central section and side sections surrounding the central section, the central section having an outer shape including a recess. 9. An article of footwear according to any of paragraphs 1 to 8, wherein the sole structure includes, for each chamber, a corresponding chamber cap positioned between the top of the chamber and the bottom of the support plate. 10. The footwear article of paragraph 9, wherein each of the chamber caps has a rounded upper surface that contacts the bottom surface of the support plate. 11. An article of footwear as described in paragraph 10, wherein for each chamber cap, the cap top material forming the rounded upper surface has a coefficient of friction with the bottom surface of the support plate that is less than the coefficient of friction with the bottom surface of the support plate of the material forming the upper surface of the chamber corresponding to the chamber cap. 12. The footwear article of paragraph 9, wherein a first of the chambers comprises a flexible wall forming part of the chamber, the flexible wall configured to expand as the volume of the electrorheological fluid in the chamber increases and to contract as the volume of the electrorheological fluid in the chamber decreases, the flexible wall of the first chamber comprising a central section and side sections surrounding the central section, the central section of the flexible wall of the first chamber having an outer shape including a recess, and a chamber cap corresponding to the first chamber comprising a protrusion extending into the recess and a skirt surrounding the side sections of the flexible wall of the first chamber. 13. The footwear article of any of paragraphs 1-12, wherein the transmission channel is configured such that the volume of electrorheological fluid in the transmission channel remains substantially constant as the volume of electrorheological fluid in the chamber changes. 14. The article of footwear of any of paragraphs 1-13, wherein the chambers include one or more medial chambers positioned on the medial side of the tilt adjuster forefoot section and one or more lateral chambers positioned on the lateral side of the tilt adjuster forefoot section. 15. The footwear article of paragraph 14, wherein there is more outer chamber than inner chamber. 16. The footwear article of paragraph 14, wherein there is more inner chamber than outer chamber. 17. The article of footwear of paragraph 14, wherein the inner chamber comprises a front inner chamber, a middle inner chamber, and a rear inner chamber, and the outer chamber comprises a front outer chamber, a middle outer chamber, and a rear outer chamber. 18. The article of footwear of any of paragraphs 1-17, wherein the electric field-generating portion extends through the midfoot and heel regions of the sole structure. 19. The footwear article of any of paragraphs 1 to 18, wherein the electric field-generating portion has a length L and an average width W, and the ratio L / W is at least 50. 20. The footwear article of any of paragraphs 1 to 19, wherein transmission channels other than the flow rate regulating transmission channel do not have electrodes. 21. An article of footwear according to any of paragraphs 1 to 20, wherein the tilt adjuster comprises a body in which the transmission channels are housed, and each of the chambers is rounded in the plane of the body in which it extends and has a diameter in the plane of the body of between 15 millimeters and 30 millimeters. 22. An article comprising: a tilt adjuster comprising a body; and at least three variable volume chambers extending outwardly from the body, each of the chambers containing an electrorheological fluid and configured to vary its outward extension in response to changes in the volume of the electrorheological fluid in the chamber; the chambers connected in series by transmission channels, each of the transmission channels allowing flow between two of the chambers; the transmission channels comprising a flow regulating transmission channel, the flow regulating transmission channel comprising opposing first and second electrodes extending along an interior of an electric field generating portion of the flow regulating transmission channel; the electric field generating portion having a length L and an average width W, wherein the ratio L / W is at least 50. 23. The article of paragraph 22, wherein the first chamber in the series of chambers is not connected to the last chamber in the series. 24. The article of paragraph 22 or 23, wherein each of the chambers comprises a flexible wall forming a portion of the chamber, the flexible wall configured to expand as the volume of the electrorheological fluid in the chamber increases and configured to contract as the volume of the electrorheological fluid in the chamber decreases. 25. The article of paragraph 24, wherein the flexible wall of one of the chambers comprises a central section and side sections surrounding the central section, the side sections comprising at least one fold that defines the accordion shape of the chamber. 26. The article of paragraph 24, wherein for each of at least two of the chambers, the flexible wall comprises a central section and a side section surrounding the central section, the side section comprising at least one fold that defines a bellows shape of the chamber. 27. The article of paragraphs 24, 25, or 26, wherein the flexible wall of one of the chambers comprises a central section and side sections surrounding the central section, the central section having a contour that includes a recess. 28. The article of paragraph 24, 25, or 26, wherein for each of at least two of the chambers, the flexible wall comprises a central section and side sections surrounding the central section, the central section having a contour including a recess. 29. The article of any of paragraphs 22-28, wherein the transmission channel is configured such that the volume of electrorheological fluid in the transmission channel remains substantially constant as the volume of electrorheological fluid in the chamber changes. 30. The article of any of paragraphs 22-29, wherein the chamber comprises one or more inner chambers disposed on the inside of the tilt adjuster and one or more outer chambers disposed on the outside of the tilt adjuster. 31. The article of paragraph 30, having more outer chambers than inner chambers. 32. The article of paragraph 30, having more inner chambers than outer chambers. 33. The article of paragraph 30, wherein the inner chamber comprises a front inner chamber, a middle inner chamber, and a rear inner chamber, and the outer chamber comprises a front outer chamber, a middle outer chamber, and a rear outer chamber. 34. The article of any of paragraphs 22-33, wherein no delivery channels other than the flow regulating delivery channels have electrodes. 35. A method comprising: molding a first component having a top side and a plurality of transmission channel first portions defined on the top side, one of the transmission channel first portions comprising a portion of a first electrode exposed along an electric field-generating portion of one of the transmission channel first portions; and molding a second component having a bottom side, a top side and a plurality of transmission channel second portions defined on the bottom side, one of the transmission channel second portions comprising a portion of a second electrode exposed along an electric field-generating portion of one of the transmission channel second portions, the top portion of each of at least three chambers comprising a second electrode. extending outward from a top side of the component; joining the top side of the first component to the bottom side of the second component to form a tilt adjuster, wherein the transmission channel first portion aligns with the transmission channel second portion to form a transmission channel connecting the chambers in series and providing fluid communication between the chambers, and wherein an electric field generating portion of one of the transmission channel first portions aligns with an electric field generating portion of one of the transmission channel second portions; filling the internal volume with an electrorheological fluid, wherein the internal volume includes the internal volumes of the chambers and the transmission channel; and sealing the internal volume. 36. The method of paragraph 35, wherein molding the second component includes separately molding an upper portion of at least three chambers and molding the remainder of the second component over the upper portion of the at least three chambers. 37. The method of paragraph 36, comprising molding a first layer of a second component over the upper portions of the at least three chambers, attaching a second electrode to the first layer of the second component, and molding a second layer of the second component over the first layer of the second component and the second electrode.

[0097] The foregoing description of the embodiments has been presented for purposes of illustration and description. The foregoing description is not intended to be exhaustive or to limit the embodiments of the invention to the precise form disclosed, as modifications and variations are possible in light of the above teachings or may be acquired from practice of various embodiments. The embodiments discussed herein were chosen and described to explain the principles and properties of various embodiments and their practical applications, and to enable those skilled in the art to utilize the invention in various embodiments and with various modifications as suited to the particular use contemplated. All combinations, subcombinations, and permutations of features of the embodiments described herein are within the scope of the invention. In the claims, reference to a potential or intended wearer or user of a component does not require the actual wearing or use of the component, or the presence of a wearer or user, to be part of the claimed invention.

Claims

1. An article of footwear, Upper and a sole structure coupled to the upper, the sole structure comprising a midsole, a tilt adjuster, and a support plate; the midsole is disposed in a forefoot portion of the sole structure, a midfoot portion of the sole structure, and a heel portion of the sole structure; the support plate is disposed in at least the forefoot portion of the sole structure; the tilt adjuster comprises a tilt adjuster forefoot portion disposed between the midsole and the support plate in the forefoot portion of the sole structure, the tilt adjuster forefoot portion comprising at least three chambers; each of the chambers contains an electrorheological fluid and is configured to vary its outward extension in response to a change in volume of the electrorheological fluid within the chamber; the chambers are connected in series by communication channels, each of the communication channels allowing flow between two of the chambers; the transmission channel comprises opposing first and second electrodes extending along an interior of an electric field-generating portion of the transmission channel comprising the opposing first and second electrodes; a transmission channel comprising the opposing first and second electrodes extends rearward from a first chamber in the forefoot portion of the tilt adjuster to the heel portion of the sole structure and returns forward to a second chamber in the forefoot portion of the tilt adjuster; Footwear.

2. a first chamber in the series of chambers is not connected to a last chamber in the series of chambers; 10. The footwear of claim 1.

3. each of the chambers includes a flexible wall forming a portion of the chamber, the flexible wall configured to expand as a volume of the electrorheological fluid in the chamber increases and to contract as the volume of the electrorheological fluid in the chamber decreases; 10. The footwear of claim 1.

4. the tilt adjuster comprises a body in which the transmission channel is housed and through which the flexible wall of the chamber extends; 4. The footwear of claim 3.

5. the flexible wall of one of the chambers comprises a central section and side sections surrounding the central section; the side sections include at least one fold that defines a bellows shape of the chamber; 4. The footwear of claim 3.

6. the flexible wall of one of the chambers comprises a central section and side sections surrounding the central section; the central section has a contour including a recess; 4. The footwear of claim 3.

7. The sole structure includes, for each of the chambers, a corresponding chamber cap positioned between the top of the chamber and the bottom of the support plate.

10. The footwear of claim 1.

8. each of the chamber caps having a rounded top surface that contacts the bottom surface of the support plate; 8. The footwear of claim 7.

9. for each of the chamber caps, a cap top material forming the rounded top surface has a coefficient of friction with the surface of the bottom of the support plate that is less than a coefficient of friction with the surface of the bottom of the support plate of a material forming the top surface of the chamber corresponding to the chamber cap; 9. The footwear of claim 8.

10. a first one of the chambers includes a flexible wall forming a portion of the chamber, the flexible wall configured to expand as a volume of the electrorheological fluid in the chamber increases and to contract as a volume of the electrorheological fluid in the chamber decreases; the flexible wall of the first chamber comprises a central section and side sections surrounding the central section; the central section of the flexible wall of the first chamber has a contour that includes a recess; the chamber cap corresponding to the first chamber includes a protrusion extending into the recess and a skirt surrounding the side section of the flexible wall of the first chamber; 8. The footwear of claim 7.

11. the transfer channel is configured such that the volume of the electrorheological fluid in the transfer channel remains substantially constant as the volume of the electrorheological fluid in the chamber changes.

10. The footwear of claim 1.

12. the chambers comprising one or more medial chambers disposed on a medial side of the forefoot portion of the tilt adjuster and one or more lateral chambers disposed on a lateral side of the forefoot portion of the tilt adjuster; 10. The footwear of claim 1.

13. the inner chamber comprises a front inner chamber, a middle inner chamber, and a rear inner chamber; The outer chamber comprises a front outer chamber, a middle outer chamber, and a rear outer chamber.

13. The footwear article of claim 12.

14. the electric field-generating portion extends through the midfoot region and heel region of the sole structure; 10. The footwear of claim 1.

15. The transmission channels include at least one transmission channel that does not have an electrode.

10. The footwear of claim 1.

16. The electric field generating portion has a length L and an average width W, and the ratio L / W is at least 50.

10. The footwear of claim 1.

17. a first chamber in the series of chambers is not connected to a last chamber in the series of chambers; 17. The article of footwear of claim 16.

18. each of the chambers includes a flexible wall forming a portion of the chamber, the flexible wall configured to expand as a volume of the electrorheological fluid in the chamber increases and to contract as the volume of the electrorheological fluid in the chamber decreases; 17. The article of footwear of claim 16.

19. the flexible wall of one of the chambers comprises a central section and side sections surrounding the central section; the side sections include at least one fold that defines a bellows shape of the chamber; 19. The article of footwear of claim 18.

20. For each of at least two of the chambers, the flexible wall comprises a central section and side sections surrounding the central section; the side sections include at least one fold that defines a bellows shape of the chamber; 19. The article of footwear of claim 18.

21. the flexible wall of one of the chambers comprises a central section and side sections surrounding the central section; the central section has a contour including a recess; 19. The article of footwear of claim 18.

22. For each of at least two of the chambers, the flexible wall comprises a central section and side sections surrounding the central section; the central section has a contour including a recess; 19. The article of footwear of claim 18.

23. the transfer channel is configured such that the volume of the electrorheological fluid in the transfer channel remains substantially constant as the volume of the electrorheological fluid in the chamber changes.

17. The article of footwear of claim 16.

24. the chambers include one or more inner chambers disposed on the inside of the tilt adjuster and one or more outer chambers disposed on the outside of the tilt adjuster; 17. The article of footwear of claim 16.

25. There are more outer chambers than inner chambers; 25. The article of footwear of claim 24.

26. There are more inner chambers than outer chambers; 25. The article of footwear of claim 24.

27. the inner chamber comprises a front inner chamber, a middle inner chamber, and a rear inner chamber; The outer chamber comprises a front outer chamber, a middle outer chamber, and a rear outer chamber.

25. The article of footwear of claim 24.

28. the transmission channels other than the transmission channel having the opposing first and second electrodes do not have electrodes; 17. The article of footwear of claim 16.

29. The sole structure includes, for at least one of the chambers, a corresponding chamber cap positioned between an upper portion of the chamber and a bottom portion of the support plate, the chamber cap having an upper surface in contact with the support plate.

10. The footwear of claim 1.

30. the chamber cap includes a recess configured to receive a corresponding portion of the chamber; 30. The article of footwear of claim 29.

31. the chamber cap includes a protrusion configured to fit within an exterior recess of the corresponding chamber; 30. The article of footwear of claim 29.

32. the chamber cap includes a skirt configured to surround at least a portion of an outer sidewall of the corresponding chamber; 30. The article of footwear of claim 29.

33. the sole structure comprises, for each of the chambers on the medial side of the tilt adjuster, a corresponding inner chamber cap disposed between a top of the chamber and a bottom of the support plate, and for each of the chambers on the lateral side of the tilt adjuster, a corresponding outer chamber cap disposed between a top of the chamber and a bottom of the support plate, each of the inner chamber caps including a similar configuration and each of the outer chamber caps including a similar configuration different from the configuration of the inner chamber cap; 30. The article of footwear of claim 29.

34. the inner chamber cap configuration or the front outer chamber cap configuration includes a recess configured to receive a portion of the corresponding chamber; 34. The article of footwear of claim 33.

35. the inner chamber cap configuration or the front outer chamber cap configuration includes a protrusion configured to fit within an outer recess of the corresponding chamber; 34. The article of footwear of claim 33.

36. the inner chamber cap configuration or the front outer chamber cap configuration includes a skirt configured to surround at least a portion of the outer sidewall of the corresponding chamber; 34. The article of footwear of claim 33.

37. the chamber cap includes an upper surface having a rounded convex shape; 30. The article of footwear of claim 29.

38. the chamber cap including an upper surface configured to prevent movement of the chamber cap across the support plate and to provide a camming action against the support plate.

30. The article of footwear of claim 29.

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