Footwear heel spring device

Abstract

A device configured to enclose a portion of a foot-receiving cavity (1839) in a heel region (13) of an article of footwear includes a control strip having a central segment, a first side arm extending from the central segment, and a second side arm spaced apart from the first side arm and extending from the central segment. The control strip may include a series of slats. A base supports the control strip and is connected to the first and second side arms. The control strip is biased to an unstressed position in which the central segment is a first distance (D1, D2) from the base and elastically bends under an applied force to a loaded position (10A, 910A, D2) in which the central segment is a second distance (D1, D2) from the base that is less than the first distance (D1, D2). The device stores potential energy that causes the control strip to return to the unloaded position when the applied load is removed.

Description

[0001] This application is a divisional application of the invention patent application with application date of October 25, 2017, application number 201780066079.X, and invention name “Footwear Heel Spring Device”.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims the benefit of priority to U.S. Provisional Application No. 62 / 413,062, filed on October 26, 2016, and also claims the benefit of priority to U.S. Provisional Application No. 62 / 532,449, filed on July 14, 2017, both of which are incorporated herein by reference in their entireties. Technical Field

[0004] The present teachings generally include heel spring devices for articles of footwear. Background Art

[0005] Traditionally, placing footwear on the foot often requires using one or two hands to stretch the ankle opening of the footwear upper and hold the rear portion during foot insertion, particularly with relatively soft uppers and / or uppers that lack a rearward-facing flexible fabric heel counter secured to the ankle opening. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 is a schematic diagram of a perspective view of a heel spring device of an article of footwear in an unloaded position.

[0007] Figure 2 yes Figure 1 Schematic diagram of a plan view of a device, wherein the loading position of the device is shown in dotted lines.

[0008] Figure 3 It is fixed to the bottom of the shoe Figure 1 Schematic diagram of a rear view of the device, with the loading position shown in dotted lines.

[0009] Figure 4 It is along Figure 3 The line 4-4 in the Figure 3 A schematic diagram of a partial cross-sectional view of a device and a sole layer, and showing a flexible covering of a footwear upper secured to the device.

[0010] Figure 5 is included Figure 4 Schematic diagram of a partial side view of the lateral side of an article of footwear showing an apparatus, a footwear upper, and a sole layer.

[0011] Figure 6 yes Figure 5 Schematic diagram of a partial side view of the medial side of an article of footwear.

[0012] Figure 7 is a schematic diagram of a partial side view of the medial side of an alternative embodiment of an article of footwear including an alternative heel spring arrangement.

[0013] Figure 8 yes Figure 7 Schematic diagram of a partial side view of the lateral side of an article of footwear.

[0014] Figure 9 is a schematic diagram of a perspective view of an alternative embodiment of an article of footwear including an alternative heel spring arrangement.

[0015] Figure 10 is a schematic diagram of a side view of the medial side of an alternative embodiment of an article of footwear including an alternative heel spring arrangement.

[0016] Figure 11 is a schematic diagram of a partial side view of the lateral side of an alternative embodiment of an article of footwear including an alternative heel spring arrangement.

[0017] Figure 12 yes Figure 11 Schematic diagram of a rear view of an article of footwear.

[0018] Figure 13 yes Figure 11 Schematic diagram of a partial plan view of an article of footwear.

[0019] Figure 14 yes Figure 13 Along Figure 13 Schematic diagram of a partial cross-sectional view of an article of footwear taken along line 14-14 in FIG.

[0020] Figure 15 is a schematic diagram of a partial side view of the lateral side of an alternative embodiment of an article of footwear including an alternative heel spring arrangement.

[0021] Figure 16 is a schematic diagram of a partial side view of the lateral side of an alternative embodiment of an article of footwear including an alternative heel spring arrangement.

[0022] Figure 17 is a schematic diagram of a partial side perspective view of the lateral side of an alternative embodiment of an article of footwear including an alternative heel spring arrangement.

[0023] Figure 18 yes Figure 17 Schematic diagram of a rear perspective view of an article of footwear.

[0024] Figure 19 is a schematic diagram of a partial perspective view of an alternative embodiment of an article of footwear including an alternative heel spring arrangement.

[0025] Figure 20 is a schematic diagram of a perspective view of an alternative embodiment of an article of footwear including an alternative heel spring arrangement.

[0026] Figure 21 yes Figure 20 Schematic diagram of a perspective view of a heel spring device.

[0027] Figure 22 yes Figure 21 Schematic diagram of another perspective view of the heel spring device, with the loaded position shown in phantom.

[0028] Figure 23 Shown are representative graphs of force in Newtons versus displacement in millimeters during loading and unloading of a heel spring assembly within the scope of the present teachings.

[0029] Figure 24 is a schematic diagram of a perspective view of an alternative embodiment of an article of footwear including an alternative heel spring arrangement.

[0030] Figure 25 yes Figure 24 Schematic diagram of a perspective view of a heel spring device.

[0031] Figure 26 is a schematic diagram of a perspective view of an alternative embodiment of an article of footwear including an alternative heel spring arrangement.

[0032] Figure 27 yes Figure 26 Schematic diagram of a perspective view of a heel spring device.

[0033] Figure 28 is a schematic diagram of a side view of the medial side of an alternative embodiment of a heel spring apparatus for an article of footwear.

[0034] Figure 29 yes Figure 28 Schematic diagram of a rear view of a heel spring device.

[0035] Figure 30 is a schematic diagram of a perspective view of an alternative embodiment of a heel spring apparatus for an article of footwear.

[0036] Figure 31 yes Figure 30 Schematic diagram of a side view of the lateral side of the heel spring device.

[0037] Figure 32 is a schematic diagram of a partial side perspective view of the lateral side of an alternative embodiment of an article of footwear including an alternative heel spring arrangement.

[0038] Figure 33 is a schematic diagram of a partial perspective view of an alternative embodiment of an article of footwear including an alternative heel spring arrangement.

[0039] Figure 34 is a schematic diagram of a perspective view of an alternative embodiment of a heel spring apparatus for an article of footwear.

[0040] Figure 35 yes Figure 34 Schematic diagram of a rear view of a heel spring device secured to a shoe upper.

[0041] Figure 36 is a schematic diagram of a perspective view of an alternative embodiment of a heel spring apparatus for an article of footwear.

[0042] Figure 37 is in the unloaded position Figure 36 Schematic diagram of a perspective view of an article of footwear with a heel spring device.

[0043] Figure 38 Is a heel spring device in the loaded position Figure 37 A schematic diagram of a perspective view of an article of footwear.

[0044] Figure 39 is a schematic diagram of a perspective view of an article of footwear having an alternative embodiment of a heel spring device in an unloaded position.

[0045] Figure 40 Is a heel spring device in the loaded position Figure 39 A schematic diagram of a perspective view of an article of footwear.

[0046] Figure 41 is a schematic diagram of a perspective view of an alternative embodiment of a heel spring apparatus for an article of footwear.

[0047] Figure 42 is in the unloaded position Figure 41 Schematic diagram of a perspective view of an article of footwear with a heel spring device.

[0048] Figure 43 Is a heel spring device in the loaded position Figure 42 A schematic diagram of a perspective view of an article of footwear.

[0049] Figure 44 is a schematic diagram of a perspective view of an alternative embodiment of a heel spring apparatus for an article of footwear.

[0050] Figure 45 is in the unloaded position Figure 44 Schematic diagram of a partial perspective view of an article of footwear with a heel spring device.

[0051] Figure 46 Is a heel spring device in the loaded position Figure 45Schematic diagram of a partial perspective view of an article of footwear.

[0052] Figure 47 is a schematic diagram of a partial perspective view of an alternative embodiment of a heel spring apparatus for an article of footwear.

[0053] Figure 48 Is a Figure 47 Schematic diagram of a partial perspective view of an article of footwear showing a heel spring device in an unloaded position.

[0054] Figure 49 is a schematic diagram of a perspective view of an article of footwear having an alternative embodiment of a heel spring device in an unloaded position and showing a loaded position in phantom.

[0055] Figure 50 is a schematic diagram of a partial side view of an article of footwear having an alternative embodiment of a heel spring device in an unloaded position.

[0056] Figure 51 Is a heel spring device in the loaded position Figure 50 Schematic diagram of a partial side view of an article of footwear.

[0057] Figure 52 is a schematic diagram of a perspective view of an alternative embodiment of a heel spring device in an unloaded position and showing a portion of the upper and sole structure in phantom lines.

[0058] Figure 53 is a schematic diagram of a side view of an article of footwear having an alternative embodiment of a heel spring device in an unloaded position and showing the loaded position in phantom.

[0059] Figure 54 is a schematic diagram of a partial perspective view of an article of footwear having an alternative embodiment of a heel spring device in an unloaded position.

[0060] Figure 55 yes Figure 54 Schematic diagram of a side perspective view of the lateral side of the heel spring device in an unloaded position.

[0061] Figure 56 yes Figure 54 Schematic diagram of a perspective outside view of a heel spring assembly in a loaded position.

[0062] Figure 57 yes Figure 54 Schematic diagram of a front view of a heel spring device.

[0063] Figure 58 yes Figure 57 Along Figure 57 Schematic cross-sectional view of the heel spring device taken along line 58-58 in FIG.

[0064] Figure 59 Includes straps that secure to the upper Figure 54 Schematic diagram of a partial side view of a portion of an article of footwear.

[0065] Figure 60 yes Figure 59 Schematic diagram of a partial view of a portion of a strip.

[0066] Figure 61 is a schematic diagram of a perspective view of an article of footwear having an alternative embodiment of a heel spring device in an unloaded position.

[0067] Figure 62A yes Figure 61 Schematic diagram of a perspective side view of a heel spring assembly in an unloaded position.

[0068] Figure 62B yes Figure 62A Schematic diagram of a perspective side view of a heel spring assembly in a loaded position.

[0069] Figure 63 yes Figure 61 Schematic diagram of a perspective rear view of a heel spring assembly in an unloaded position with a compressible insert removed.

[0070] Figure 64 yes Figure 61 Schematic diagram of a perspective inside view of a compressible insert of a heel spring device in an unloaded position.

[0071] Figure 65 It is along Figure 66 The line 65-65 intercepts Figure 66 Schematic cross-sectional view of a heel spring arrangement.

[0072] Figure 66 yes Figure 61 Schematic diagram of a front view of a heel spring device.

[0073] Figure 67 is a schematic diagram of a partial perspective view of an article of footwear having an alternative embodiment of a heel spring in an unloaded position.

[0074] Figure 68 is a schematic diagram of a perspective view of an article of footwear having an alternative embodiment of a heel spring device in an unloaded position.

[0075] Figure 69 yes Figure 68 Schematic diagram of a perspective view of a heel spring device in an unloaded position, wherein the heel spring device.

[0076] Figure 70 yes Figure 69 Schematic diagram of a front view of a heel spring device.

[0077] Figure 71A yes Figure 70 Along Figure 70 Schematic cross-sectional view of the heel spring device taken along line 71A-71A in FIG.

[0078] Figure 71B is in loading position Figure 71A Schematic cross-sectional view of a heel spring arrangement.

[0079] Figure 72 is a schematic diagram of a perspective rear view of an alternative embodiment of a heel spring assembly in an unloaded position.

[0080] Figure 73 is a schematic diagram of a perspective rear view of an alternative embodiment of a heel spring assembly in an unloaded position.

[0081] Figure 74 is a schematic diagram of a perspective view of an article of footwear having an alternative embodiment of a heel spring device in an unloaded position.

[0082] Figure 75 yes Figure 74 Schematic diagram of a perspective side view of a heel spring assembly in an unloaded position.

[0083] Figure 76 yes Figure 75 Along Figure 75 Schematic cross-sectional view of the heel spring device taken along line 76-76 in FIG.

[0084] Figure 77 yes Figure 74 Schematic diagram of a side view of a heel spring assembly in an unloaded position.

[0085] Figure 78 is in loading position Figure 74 Schematic diagram of a side view of a heel spring device.

[0086] Figure 79 is a schematic diagram of a perspective view of an alternative embodiment of a heel spring assembly in an unloaded position.

[0087] Figure 80 Is a Figure 79 Schematic diagram of the lateral side of an article of footwear with a heel spring device.

[0088] Figure 81 yes Figure 80 Schematic diagram of the medial side of an article of footwear.

[0089] Figure 82 yes Figure 80 Schematic diagram of a rear view of an article of footwear.

[0090] Figure 83 yes Figure 80 A plan view of a midsole of an article of footwear.

[0091] Figure 84 yes Figure 83 A plan view of the midsole, wherein Figure 79 The heel spring assembly is seated in a recess in the midsole.

[0092] Figure 85 is a schematic diagram of a perspective view of an alternative embodiment of a heel spring assembly in an unloaded position.

[0093] Figure 86 yes Figure 85 Schematic diagram of another perspective view of the heel spring device.

[0094] Figure 87 Is a Figure 85 Schematic diagram of an article of footwear with a heel spring device and showing the upper in dotted lines.

[0095] Figure 88 yes Figure 85 Schematic partial plan view of an arm of a heel spring device connected to a component of a footwear upper.

[0096] Figure 89 yes Figure 87 Schematic plan view of a midsole of an article of footwear.

[0097] Figure 90 yes Figure 85 The seat is Figure 89 Schematic diagram of a plan view of a heel spring device within a recessed portion of a midsole.

[0098] Figure 91 yes Figure 85 Exploded partial view of the heel spring assembly of FIG, with the tab of the upper extending through the hole in the heel spring assembly and the pin shown.

[0099] Figure 92 yes Figure 85 Partial view of a heel spring assembly having a tab secured in a ring and wherein a pin is inserted in the ring.

[0100] Figure 93 is a schematic diagram of a plan view of an alternative embodiment of a heel spring assembly.

[0101] Figure 94 is included Figure 93Schematic diagram of a rear view of an article of footwear of a heel spring device. DETAILED DESCRIPTION

[0102] Disclosed herein are heel spring devices for facilitating foot entry into an article of footwear. Each heel spring device can enable hands-free foot entry, such as by loading the heel spring device with the foot to enter a foot-receiving cavity from a rearward position and sliding the foot forward and downward into the foot-receiving cavity.

[0103] Within the scope of the present disclosure, a device for facilitating foot entry into a foot-receiving cavity of an article of footwear is configured to surround a portion of the foot-receiving cavity in a heel region of the article of footwear and includes a control strip having a central segment, a first side arm extending from the central segment, and a second side arm spaced apart from the first side arm and extending from the central segment. A continuous base can support the control strip and can be connected to both the first side arm and the second side arm. The control strip is biased to an unloaded position in which the central segment is a first distance from the base, and elastically deforms under an applied force to a loaded position in which the central segment is a second distance from the base that is less than the first distance. The device stores potential energy that causes the control strip to return to an unstressed position when the applied load is removed.

[0104] In one or more embodiments of the device, the base is connected to the first side arm at a first joint, and the base is connected to the second side arm at a second joint.The joints may be referred to herein as articulated joints, or as articulated joints.

[0105] The device including the control strip and the base can be a single, unitary, one-piece component. For example, in one or more embodiments, the control strip has an arcuate shape, and the base has an arcuate shape. Thus, the control strip and the base are configured as a full elliptical leaf spring.

[0106] In one or more embodiments of the device, the base includes a central section, a first base arm, and a second base arm, all disposed in a common plane. The first base arm is spaced apart from the second base arm and both extend from the central section of the base. The first base arm and the first side arm are connected at a first joint. The second base arm and the second side arm are connected at a second joint. When the control bar is in an unloaded position, the first side arm and the second side arm extend at an acute angle relative to the common plane of the base. When the control bar is depressed, the first side arm and the second side arm extend at a second acute angle relative to the common plane of the base. The second acute angle is smaller than the first acute angle.

[0107] In one or more embodiments of the device, when the control strip is in the loaded position, the first side arm and the second side arm are bent apart from each other. When the side arms are bent apart, the foot-receiving cavity of the footwear upper opens wider, thereby further facilitating entry of the foot into the foot-receiving cavity.

[0108] In one or more embodiments of the device, one of the control strip and the base includes an extension extending toward the other. When the control strip is in an unstressed position, the extension is spaced apart from the other, and when the control strip is in a loaded position, the extension contacts the other, thereby limiting further downward pressure on the control strip. The extension thus limits the amount of deformation, such as by preventing the second angle from becoming too small, thereby preventing plastic deformation.

[0109] In one or more embodiments of the device, a central section of the control strip has an extension extending toward the base, and the base has a recess. When the control strip is in an unloaded position, the extension is spaced apart from the base, and when the control strip is depressed to a loaded position, the extension protrudes into the recess. The extension and recess also restrict the side-to-side movement of the control strip relative to the base by abutting the control strip and the base.

[0110] In one or more embodiments of the device, the central section of the control strip has a ramped surface that slopes toward an inner periphery of the central section between the first and second side arms. The ramped surface helps guide the foot downward and forward into the foot-receiving cavity during application of a downward force on the control strip.

[0111] In one or more embodiments of the device, the first and second side arms each twist outward along their respective longitudinal axes from the base to the central section of the control strip. The outward twisting helps promote downward and rearward movement of the central section during foot loading.

[0112] In one or more embodiments of the device, the first side arm and the second side arm are asymmetrical about a longitudinal axis extending through the base between the first side arm and the second side arm. For example, the first side arm may be a medial arm, and the second side arm may be a lateral arm. Similar to the shape of a typical heel region of a foot, the medial arm may be shorter than the lateral arm and may have a greater lateral curvature than the lateral arm.

[0113] In one or more embodiments of the device, the base has an inwardly extending flange.For example, the flange can be positioned in the recess and secured to a foot-receiving surface of a footwear sole structure in a heel region of the sole structure.

[0114] In one or more embodiments of the apparatus, the footwear sole structure may have an outer wall having a recess in the heel region, and the base of the apparatus may be at least partially seated in the recess and secured to the outer wall of the sole structure.

[0115] In one or more embodiments of the device, the base can be positioned below the control strip, with the first side arm positioned at the medial side of the upper defining at least a portion of the ankle opening, the second side arm positioned at the lateral side of the upper, and the central segment of the control strip positioned rearward of the ankle opening of the upper.

[0116] In one or more embodiments of the device, the front-most portion of the inner surface of the first side arm includes a medial recess, such that the first side arm is thinner at the medial recess than behind the medial recess, and the front-most portion of the inner surface of the second side arm includes a lateral recess, such that the second side arm is thinner at the lateral recess than behind the lateral recess. The upper can be secured to the first side arm at the medial recess and to the second side arm at the lateral recess.

[0117] In one or more embodiments of the device, the central segment has a hole, and the footwear upper includes a tab extending through the hole. The tab can be secured to a rear portion of the footwear upper. A pin can be secured to the tab behind the hole. The tab with the pin can be wider than the hole, such that the tab is anchored to the central segment by the pin.

[0118] In one or more embodiments of the device, a lever may extend outwardly from the control strip. The lever may assist in depressing the control strip.

[0119] In one or more embodiments, the heel device includes a sac element that includes one or more fluid-filled internal cavities. The one or more fluid-filled internal cavities may include a cavity extending along the central segment. The cavity extending along the central segment may also extend along one or both of the first side arm or the second side arm and may be tubular or other shapes. The one or more fluid-filled internal cavities may also include one or more reservoirs that are disposed on one or both of the first side arm and the second side arm and are in fluid communication with the cavity extending along the central segment. When the heel spring device resiliently deforms under the action of the applied force, the one or more reservoirs expand as the fluid is transferred from the cavity extending along the central segment.

[0120] The base of the device can be secured to a flexible footwear upper that defines at least a portion of an ankle opening, such that the base is positioned below the control strip, wherein the first side arm is positioned at the medial side of the footwear upper, the second side arm is positioned at the lateral side of the footwear upper, and the central section of the control strip is positioned rearward of the ankle opening. The base can extend from the lateral side to the medial side around a rearwardly rearward portion of the footwear upper. The control strip can be embedded within the footwear upper.

[0121] The flexible footwear upper may define a foot-receiving space (also referred to as a foot-receiving cavity), and the base may be located below the foot-receiving space. The base may be coupled to a forward-most portion of the first and second side arms. The base may extend rearward from the control strip, the base may extend forward from the control strip, or the base may extend both rearwardly and forwardly from the control strip.

[0122] In one or more embodiments, the base has a forwardly extending protrusion adjacent a medial side of the footwear upper that underlies the foot-receiving void and a rearwardly extending protrusion along a lateral side of the footwear upper that underlies the foot-receiving void.

[0123] In one or more embodiments, a sole structure is secured to a footwear upper and positioned beneath a foot-receiving void. The sole structure has a foot-facing surface with a recess, a base having a main portion and a protrusion extending from the main portion, and the protrusion is configured to be positioned within the recess.

[0124] In one or more embodiments of the device, the central section of the control strip has a hole. A heel pull tab of the shoe upper can extend through the hole to further secure the footwear upper to the device. The device can have a thinned portion that allows the device to be sewn to the shoe upper through the thinned portion.

[0125] In one or more embodiments of the device, the control strip is embedded in the footwear upper.For example, the device can be covered by a layer of the flexible cover of the footwear upper and be covered between these layers.

[0126] In one or more embodiments of the device, the base of the device is a sole structure of a footwear article. In another embodiment of the device, the base is a flexible footwear upper. In such an embodiment, the upper provides elastic deflection at the junction with the control strip.

[0127] In one or more embodiments of the device, the first side arm and the second side arm each have at least one slot extending therethrough. In one or more embodiments, the at least one slot extending through the first side arm may extend through the first side arm along the length of the first side arm, and the at least one slot extending through the second side arm may extend through the second side arm along the length of the second side arm. In an alternative embodiment, the at least one slot extending through the first side arm extends transverse to the length of the first side arm, and the at least one slot extending through the second side arm extends transverse to the length of the second side arm.

[0128] Within the scope of the present disclosure, a heel spring device for facilitating foot entry into an article of footwear is configured to surround a portion of a foot-receiving cavity in the heel region of the article of footwear and includes a control strip and a base positioned below the control strip. In one or more embodiments, the control strip comprises a series of slats. Each slat has a central segment, a medial arm extending from the central segment to a medial end connected to the medial side of the base, and a lateral arm extending from the central segment to a lateral end connected to the lateral side of the base. The control strip is biased to an unloaded position and, under the action of an applied force, elastically bends to a loaded position in which at least one central segment is closer to the base than in the unloaded position, thereby storing potential energy that causes the control strip to return to the unloaded position when the applied load is removed. For example, the control strip and base can be configured as fully elliptical leaf springs.

[0129] The device stores potential energy, such as elastic energy and / or spring energy, which causes the control strip to return to an unstressed position when the applied load is removed. As used herein, elastic bending may also be referred to as resilient bending and causes resilient deformation or elastic deformation. For example, a foot can be pressed down on the control strip and slide into the foot-receiving cavity of the attached footwear upper without having to use hands or any tools to adjust the upper to allow the foot to enter.

[0130] In one or more embodiments of the device, the control strip defines a slot extending between the slats. When the control strip is in an unloaded position, the slats are spaced apart from each other by the slot. The slot can be closed between the slats such that one or more adjacent central segments contact each other in the loaded position. The slots can be parallel to each other, and the exterior sides of the slats can be flush with each other in the unloaded position.

[0131] In one or more embodiments of the device, the lowermost slat at the central segment, closest to the base, is shorter from its medial end to its lateral end than the uppermost slat furthest from the central segment. In one or more embodiments, the lowermost slat is thinner than the uppermost slat. In one or more embodiments of the device, the lowermost slat has a tab extending from the lower edge of the central segment. The outer surface of the base can have a peripheral recess extending from the lower edge of the base. For example, the peripheral recess can receive a flange of the sole structure.

[0132] In one or more embodiments of the device, the elastic insert at least partially fills the slot. The elastic insert may include a resiliently compressible material such as at least one of rubber or thermoplastic polyurethane, and may be foam, but is not limited to these materials. The elastic insert may include a sleeve extending along the inside of the slats, and spaced apart protrusions extending from the sleeve into the slot. In one or more embodiments of the device, the elastic insert is configured as a pleat that extends outward from the inside of the slats between the slats.

[0133] Within the scope of the present disclosure, a heel spring device for facilitating foot entry into an article of footwear is configured to surround a portion of a foot-receiving cavity in a heel region of the article of footwear and includes an elastic corrugated body comprising a central segment, a medial arm extending forward from the central segment, and a lateral arm extending forward from the central segment. The corrugated body may include alternating ridges and grooves extending lengthwise along the medial arm, the central segment, and the lateral arm. The corrugated body is biased to an unloaded position and, under the action of an applied force, is compressed to a loaded position in which adjacent ridges of the alternating ridges are closer together in the loaded position than in the unloaded position, thereby storing elastic energy that causes the corrugated body to return to the unloaded position when the applied load is removed.

[0134] For example, the corrugated body may include a bellow. The ridges may be convex pleats of the bellow, and the grooves may be concave folds of the bellow. The bellows may be an elastically deformable material such as at least one of rubber or thermoplastic polyurethane, and may be an elastic foam (e.g., a polymer foam material, etc.), but is not limited to these materials.

[0135] In one or more embodiments of the device, the first set of ridges and grooves extends from the medial arm to the lateral arm, and the second set of ridges and grooves extends only along the central segment.

[0136] The device may include an upper flange extending along an upper edge of the corrugation at the central segment and may also include lower flanges extending along a lower edge of the corrugation at the inner arms, central segment, and outer arms.

[0137] Within the scope of this teaching, an article of footwear includes an upper that defines at least a portion of an ankle opening, a sole structure that is fixed to the upper and located below the upper, and a heel spring device. The heel spring device may include a central segment fixed to the upper behind the ankle opening, a medial arm extending downward and forward from the central segment, a medial arm extending downward and forward from the central segment, and a base connected to both the medial arm and the lateral arm. The base may be fixed to the sole structure. The central segment is biased to an unloaded position, and the heel spring device elastically deforms to a loaded position under the action of an applied force, with the central segment closer to the base in this loaded position than in the unloaded position. The heel spring device stores elastic energy, which returns the central segment to the unloaded position when the applied load is removed, and the upper moves with the central segment so that the ankle opening is closer to the sole structure when the central segment is in the loaded position than when the central segment is in the unloaded position.

[0138] In one or more embodiments of the article of footwear, the sole structure includes a midsole, and the base is partially recessed into the midsole.

[0139] In one or more embodiments of the article of footwear, the medial arm is secured to the medial side of the upper, and the lateral arm is secured to the lateral side of the upper. When the central segment is in the loaded position, the medial and lateral arms can flex laterally outward and away from each other, thereby widening the ankle opening.

[0140] In one or more embodiments of the article of footwear, in an unloaded position, the central segment is spaced apart from the base, and the device is characterized in that there is no rigid heel stabilizer located between the central segment and the base at a rear portion of the joint between the medial arm and the base and at a rear portion of the joint between the lateral arm and the base.

[0141] In one or more embodiments of the article of footwear, the medial arm and the lateral arm each twist outward along their respective longitudinal axes from the base to the central segment.

[0142] In one or more embodiments of the article of footwear, one of the central segment and the base includes an extension that extends at least partially toward the other of the central segment and the base. When the central segment is in an unloaded position, the extension is spaced apart from the other of the central segment and the base. The extension may extend from the central segment at least partially toward the base. The base may include a recess. When the central segment is in the unloaded position, the extension may be spaced apart from the base, and when the central segment is in the loaded position, the extension may protrude into the recess.

[0143] In one or more embodiments of the article of footwear, the extension extends from the central segment at least partially toward the base, and the article of footwear further comprises a strap having a proximal end secured to the upper and a pocket at the distal end. The extension is disposed in the pocket. The strap may be external to the central segment.

[0144] In one or more embodiments of the article of footwear, an outer surface of the base has a peripheral recess extending from a lower edge of the base. The sole structure has a flange seated in the peripheral recess.

[0145] In one or more embodiments of the article of footwear, the heel spring assembly includes a bladder element comprising one or more fluid-filled internal cavities. The one or more fluid-filled internal cavities may include a cavity extending along a central segment. The cavity extending along the central segment may also extend along one or both of the medial arm or the lateral arm and may be tubular or otherwise shaped. The one or more fluid-filled internal cavities may also include one or more reservoirs disposed at one or both of the medial arm and the lateral arm and in fluid communication with the cavity extending along the central segment. When the heel spring assembly resiliently deforms under an applied force, the one or more reservoirs expand as fluid is transferred from the cavity extending along the central segment.

[0146] In one or more embodiments of the article of footwear, the central segment has a ramped surface that slopes toward an inner periphery of the central segment between the medial arm and the lateral arm.In one or more embodiments, the heel spring device is a single, unitary, one-piece component.

[0147] In one or more embodiments, a footwear upper includes a flexible cover that defines at least a portion of an ankle opening. The footwear upper includes a heel spring device comprising a control strip having a central segment secured to the flexible cover behind the ankle opening, a medial arm extending from the central segment and secured to a medial side of the flexible cover, and a lateral arm extending from the central segment and secured to a lateral side of the flexible cover. The heel spring device may further include a continuous base supporting the control strip and connected to both the medial arm and the lateral arm. The control strip is biased to an unloaded position in which the central segment is a first distance from the base, the control strip elastically deforms under an applied force to a loaded position in which the central segment is a second distance from the base that is less than the first distance, and the device stores potential energy that causes the control strip to return to the unloaded position when the applied load is removed.

[0148] In one or more embodiments of the footwear upper, the flexible covering is an elastic, stretchable fabric, and the footwear upper further includes a collar secured to the flexible covering and defining a front portion of the ankle opening. The collar is stiffer than the elastic, stretchable fabric.

[0149] In one or more embodiments, the footwear upper further includes a heel pull tab secured to the flexible cover.The central segment of the control strip has an aperture, and the heel pull tab extends through the aperture.

[0150] In one or more embodiments of the footwear upper, when the central segment is in the loaded position, the medial and lateral arms flex laterally outward and away from each other, thereby widening the ankle opening of the flexible covering.

[0151] In one or more embodiments, the footwear upper is characterized by the absence of a rigid heel counter located between the control strip and the base at a rear portion of the junction between the control strip and the base.

[0152] In one or more embodiments of the footwear upper, the medial and lateral arms each twist outward along their respective longitudinal axes from the base to a central segment of the control strip.

[0153] In one or more embodiments of the footwear upper, one of the control strip and the base has an extension that extends toward the other of the control strip and the base. When the control strip is in an unloaded position, the extension is spaced apart from the other of the control strip and the base, and when the control strip is in a loaded position, the extension contacts the other of the control strip and the base, thereby limiting further depression of the control strip.

[0154] In one or more embodiments of the footwear upper, the central section of the control strip has an extension extending toward the base, the base having a recess, the extension being spaced apart from the base when the control strip is in an unstressed position, and the extension protruding into the recess when the control strip is in a loaded position.

[0155] In one or more embodiments, a footwear upper includes a bladder element comprising one or more fluid-filled internal cavities. The one or more fluid-filled internal cavities may include a cavity extending along a central segment. The cavity extending along the central segment may also extend along one or both of the medial arm or the lateral arm and may be tubular or otherwise shaped. The one or more fluid-filled internal cavities may also include one or more reservoirs disposed at one or both of the medial arm and the lateral arm and in fluid communication with the cavity extending along the central segment. When the heel spring device rebounds under the applied force, the one or more reservoirs expand as fluid is transferred from the cavity extending along the central segment.

[0156] In one or more embodiments of the footwear upper, the central segment of the control strip has a ramped surface that slopes toward an inner periphery of the central segment between the medial arm and the lateral arm.

[0157] In one or more embodiments of the footwear upper, the heel spring device is a single, unitary, one-piece component.

[0158] In one or more embodiments, an article of footwear includes a footwear upper including a flexible covering that defines at least a portion of an ankle opening. The article of footwear also includes a sole structure secured to and positioned below the footwear upper and a heel spring device. The heel spring device may include a control strip having a central segment secured to the flexible covering behind the ankle opening, a medial arm extending downward and forward from the central segment, and a lateral arm extending downward and forward from the central segment. The heel spring device may also include a continuous base supporting the control strip and connected to both the medial arm and the lateral arm. The base may be secured to the sole structure. The control strip is biased to an unloaded position, in which the central segment is a first distance from the base. The control strip elastically bends to a loaded position under an applied force, in which the central segment is a second distance from the base that is less than the first distance. The device stores elastic energy that returns the control strip to the unloaded position when the applied load is removed. The flexible covering moves with the control strip.

[0159] In one or more embodiments of the article of footwear, the sole structure includes a midsole, and the base is partially recessed into the midsole. In one or more embodiments of the article of footwear, the medial arm is secured to a medial side of the flexible covering, and the lateral arm is secured to a lateral side of the flexible covering. In one or more embodiments of the article of footwear, when the central segment is in the loaded position, the medial arm and the lateral arm flex laterally outward and away from each other, thereby widening an ankle opening of the flexible covering. In one or more embodiments of the article of footwear, the article of footwear is characterized in that, at a rear portion of the junction between the control strip and the base, there is no rigid heel stabilizer located between the control strip and the base.

[0160] In one or more embodiments of the article of footwear, the medial arm and the lateral arm each twist outwardly along their respective longitudinal axes from the base to a central segment of the control strip. In one or more embodiments of the article of footwear, one of the control strip and the base includes an extension extending toward the other of the control strip and the base. When the control strip is in an unloaded position, the extension is spaced apart from the other of the control strip and the base, and when the control strip is in a loaded position, the extension contacts the other of the control strip and the base, thereby limiting further depression of the control strip.

[0161] In one or more embodiments of the article of footwear, the extension extends from the central segment of the control strip toward the base, the base having a recess, and the extension is spaced apart from the base when the control strip is in an unloaded position, and projects into the recess when the control strip is in a loaded position. In one or more embodiments of the article of footwear, the central segment of the control strip has a ramped surface that slopes toward an inner periphery of the central segment between the medial and lateral arms. In one or more embodiments of the article of footwear, the device is a single, unitary, one-piece component.

[0162] In one or more embodiments, an article of footwear includes a footwear upper including a flexible covering defining at least a portion of an ankle opening, a sole structure secured to and positioned below the footwear upper, and a heel spring arrangement. The heel spring arrangement may include a control strip having a central segment secured to the flexible covering behind the ankle opening, a medial arm extending downwardly and forwardly from the central segment along a medial side of the footwear upper, and a lateral arm extending downwardly and forwardly from the central segment along the medial side of the footwear upper. The heel spring arrangement may also include a mechanical spring operably connected to the control strip and biasing the control strip to an unloaded position. The control strip can pivot rearwardly to a loaded position under the action of an applied force, thereby storing potential energy in the spring that causes the control strip to return to the unloaded position when the applied load is removed, with the flexible covering moving with the control strip.

[0163] In one or more embodiments of the article of footwear, a pin is connected to both the medial arm and the lateral arm and extends through the sole structure. A spring is wound around the pin and has one end fixed to pivot with the control strip and the other end fixed relative to the control strip.

[0164] In one or more embodiments, the article of footwear comprises a footwear upper and a sole structure, wherein the footwear upper comprises a flexible covering of at least a portion defining an ankle opening, and the sole structure is fixed to the upper and is located below the footwear upper. The article of footwear may also include a heel spring device. The heel spring device may include a rear control bar, which has a central section fixed to the flexible covering behind the ankle opening, an inner side arm extending downward and forward from the central section along the medial side of the footwear upper, and a lateral arm extending downward and forward from the central section along the medial side of the footwear upper. The heel spring device may also include a front bar, which has a central section fixed to the flexible covering ahead of the ankle opening, an inner side arm extending downward and backward from the central section along the medial side of the footwear upper, and a lateral arm extending downward and backward from the central section along the medial side of the footwear upper. The front bar and the rear control bar may intersect and be fixed to each other at the lateral side of the upper and at the medial side of the upper. The rear control strip pivots rearwardly to a loaded position under the applied force, thereby storing potential energy that returns the front strip to an unloaded position when the applied load is removed, with the flexible cover moving with the rear control strip.

[0165] Within the scope of the present teachings, an article of footwear includes a footwear upper including a flexible covering defining at least a portion of an ankle opening, a sole structure secured to and positioned below the footwear upper, and a heel spring device. The heel spring device may include a control strip and a continuous base. The control strip may include a central segment secured to the flexible covering behind the ankle opening, a medial arm extending from the central segment and secured to the medial side of the flexible covering, and a lateral arm extending from the central segment and secured to the lateral side of the flexible covering. The base may support the control strip and may be connected to both the medial arm and the lateral arm and secured to the sole structure. The control strip is biased to an unloaded position, in which the central segment is a first distance from the base, and elastically bends under an applied force to a loaded position, in which the central segment is a second distance from the base that is less than the first distance. The device stores potential energy, such as elastic energy and / or spring energy, which causes the control strip to return to an unloaded position when the applied load is removed, and the flexible cover moves with the control strip.

[0166] Referring to the drawings, wherein like reference numerals represent like parts, Figure 1 Shown for easy foot entry Figure 5 and Figure 61 and 2. The apparatus 10 is shown with an article of footwear 12. The shoes herein are described as leisure shoes and athletic shoes, but the present teachings also encompass articles of footwear that are dress shoes, workshoes, sandals, slippers, boots, or any other category of footwear.

[0167] like Figure 5 , apparatus 10 is configured to enclose a portion of foot-receiving cavity 47 at heel region 13 of article of footwear 12. When a person's foot is supported on sole structure 32 in foot-receiving cavity 47 and is sized to correspond with article of footwear 12, heel region 13 generally includes a portion of article of footwear 12 that corresponds to a rear portion of the person's foot (including the ankle bone). Figure 10 、 Figure 80 and Figure 87 312, 3212, and 3312) generally include portions of the article of footwear 12 corresponding to the toes and the joints connecting the metatarsal bones and phalanges of the human foot (interchangeably referred to herein as "metatarsal-phalangeal joints" or "MPJ" joints). Figure 10 、 Figure 80 and Figure 87 12) are best shown with respect to article of footwear 312, 3212, and 3312, disposed between heel region 13 and forefoot region 15, and generally include portions of article of footwear 12 corresponding to the arch area of ​​a human foot, including the navicular joint.

[0168] The device 10 includes a control strip 14 having a central segment 16, a first side arm 18 extending downwardly and forwardly from the central segment 16, and a second side arm 20 spaced apart from the first side arm 18 and also extending downwardly and forwardly from the central segment 16. The first side arm 18 is the medial arm and the second side arm 20 is the lateral arm.

[0169] The device 10 also includes a base 22 that supports the control strip 14 and is connected to the control strip 14 at resiliently flexible joints 24A, 24B. The base 22 is continuous and extends between and connects to the first and second side arms 18, 20. The base 22 is continuous in that it extends from the first side arm 18 to the second side arm 20 without interruption or connection through other components. The base 22 has a central section 26, a first base arm 28, and a second base arm 30 that are all disposed in a common plane. When the base 22 of the device 10 is resting on a horizontal surface, the common plane P is parallel to the horizontal surface, and Figure 3This is best indicated by the dashed line P, which represents a plane perpendicular to the page of the drawing. The first base arm 28 is spaced apart from the second base arm 30, and both extend from the central section 26 of the base 22. Figure 2 As shown in FIG, the base 22 is slightly below the control strip 14, thereby providing stability to the device 10 during depression.

[0170] The joints 24A and 24B include a first joint 24A at which the base 22 and the first side arm 18 are connected, and a second joint 24B at which the base 22 and the second side arm 20 are connected. The first joint 24A connects the first base arm 28 to the first side arm 18. The second joint 24B connects the second base arm 30 to the second side arm 20.

[0171] Control strip 14 has an arcuate shape from first joint 24A to second joint 24B. Similarly, base 22 has an arcuate shape from first joint 24A to second joint 24B. With this arrangement, control strip 14 and base 22 are configured as a fully elliptical leaf spring as described herein. This device may be referred to as a heel spring. Furthermore, device 10 is a single, unitary, one-piece component. For example, device 10 may be injection molded as a single, unitary, one-piece component.

[0172] The control strip 14 is biased to Figure 1 、 Figure 2 and Figure 3 . The unloaded position is also referred to herein as the stress-free position. The control strip 14 is inherently biased to the stress-free position by its material in its formed state. In other words, the material of the control strip 14 has sufficient rigidity so that it remains in the stress-free position in its natural state (no external load applied thereto) and will return to the stress-free position after elastic bending due to its elasticity. In the stress-free position, the central segment 16 is a first distance D1 from the base 22, as shown in FIG. Figure 3 The unstressed position is where the device 10 is in a relaxed, unloaded state (i.e., no vertical force is applied to the control strip 14). The control strip 14 may be in a Figure 4 , which represents the force F applied when the foot 46 is inserted into the foot-receiving cavity 47 of the article of footwear 12 (see FIG. Figure 5 and Figure 6 ) during the period of time when the force applied by the foot 46. When loaded in this manner, the control strip 14 elastically bends to a loaded position in which the central segment 16 is a second distance D2 from the base 22. When the device 10 is in the loaded position, the device 10 is Figure 3denoted by a dashed line and reference numeral 10A. The second distance D2 is less than the first distance D1. The difference between the distances D1, D2 is the deflection of the device 10, which may be, but is not limited to, a deflection of 30 mm. The device 10 is constructed so that when it is depressed to the loaded position D2 under the action of a force, it elastically bends at the joints 24A, 24B, thereby storing elastic energy. When the force F is removed, the stored elastic energy causes the control strip 14 to return to the unstressed position. Figure 3 , only the device 10 and the sole structure 32 are shown. In order to clearly illustrate the position of the devices 10, 10A, the upper 38 described herein is removed.

[0173] As in Figure 5 and Figure 6 As shown in FIG, article of footwear 12 includes a sole structure 32 and an upper 38 secured to sole structure 32. Sole structure 32 includes one or more sole components, which may be a sole layer 34, such as an outsole, a midsole, or an integral combination of an outsole and a midsole (which may be referred to as a unisole). Figure 5 and Figure 6 In the embodiment of the present invention, the sole layer 34 can be a midsole or an integral sole. The sole layer 34 is located below the upper 38. The lower portion 40 of the footwear upper 38 is fixed to the sole layer 34, such as by adhesive or other means. The base 22 is fixed to the sole layer 34, such as by adhesive bonding, thermal bonding, or other means. The sole layer 34 can have slight recesses formed on its outer surface. The outer surface is shaped to allow the base 22 and the engaging portions 24A, 24B to partially seat in these recesses, thereby being further supported by the sole layer 34.

[0174] Flexible footwear upper 38 defines at least a portion of ankle opening 39. Base 22 is positioned below control strip 14 and secured to upper 38, with first side arm 18 secured to medial side 41 of footwear upper 38 and second side arm 20 secured to lateral side 43 of footwear upper 38. Figure 5 and Figure 6 As best shown in FIG, base 22 extends from lateral side 43 to medial side 41 around the rearmost portion of the footwear upper. Central segment 16 of control strip 14 is secured to footwear upper 38 rearward of ankle opening 39. Device 10 may have a thinned portion 45 (at Figure 3 ), which enables the footwear upper 38 to be machine-stitched to the device at the thinned portion 45.

[0175] The upper 38 may include a flexible covering 42 (also referred to as a flexible covering layer) for receiving and covering a foot 46 supported on the sole layer 34 (in the Figure 4). For example, the flexible covering 42 can be a stretchable fabric that provides a lightweight, breathable feel, such as a four-way stretch nylon fabric. The article of footwear 12 is characterized in that there is no rigid heel stabilizer located between the control strip 14 and the base 22 at the rear portion of the joint 24A, 24B between the control strip 14 and the base 22. The device 10 functions as a heel stabilizer in at least some aspects because it helps to maintain the wearer's heel in place above the heel portion of the sole structure, thereby preventing medial or lateral displacement during use. Because the device 10 is secured to the flexible covering 42, the device 10, together with the flexible covering 42 of the upper 38, can be referred to as a footwear upper. In other words, the device 10 can be considered to be a component of a multi-component footwear upper that also includes the flexible covering 42 and other components of the article of footwear. The multi-component footwear upper can also be referred to as a footwear upper assembly.

[0176] Traditionally, sliding the foot into the upper typically requires the use of one or two hands to stretch the ankle opening and hold the rear portion during foot insertion, especially with relatively soft uppers and / or uppers that do not have a flexible fabric heel counter secured to the rear of the ankle opening. The device 10 alleviates these problems and allows the foot 46 to enter the foot-receiving cavity 47 formed by the upper 38 without the use of hands or other tools. Only the foot 46 is required for entry. Specifically, as in Figure 4 As shown in FIG, using the bottom of foot 46, force F is applied to press against control strip 14, causing the device to elastically bend at joints 24A, 24B, thereby moving control strip 14 from an unstressed position to a loaded position, represented by the control strip in position 14A. Upper 38 is attached to central segment 16 and moves downward with control strip 14. When foot 46 is fully moved into foot-receiving cavity 47, the elastic energy stored by the bias of device 10 automatically returns device 10 to the unstressed position, causing upper 38 to be automatically pulled up over the rear of foot 46. Figure 5 FIG shows the position of the stretchable flexible cover 42 prior to insertion into the foot. When the device 10 is returned to the unstressed position, the flexible cover 42 stretches over the back of the heel of the foot 46 to Figure 5 The position 42A is shown by the dashed line.

[0177] In order to further facilitate the entry of the foot 46 into the foot receiving cavity 47 of the upper 38, as shown in FIG. Figure 2 and Figure 4, the central segment 16 of the control strip 14 has a ramp surface 50 that slopes toward an inner periphery 52 of the central segment 16. The slope of the central segment 16 changes at a transition line 51 between an upper portion 54 of the foot contacting surface of the control strip 14 and the ramp surface 50. The ramp surface 50 has a steeper inclination than the upper portion 54, thereby facilitating downward and inward sliding of the foot 46.

[0178] refer to Figure 5 and Figure 6 When the control strip 14 is in the unstressed position, the first side arm 18 and the second side arm 20 extend at a first acute angle A1 relative to the common plane P of the base 22. Angle A1 can be measured along the longitudinal axis of each side arm. Although shown with the same angle A1, each of the first side arm 18 and the second side arm 20 can have a different first acute angle. When the control strip 14 is depressed so that the device 10 is in the Figure 3 In position 10A, the first side arm 18 and the second side arm 20 extend at a second acute angle A2 relative to the common plane P of the base 22. Angle A2 can be measured along the longitudinal axis of each side arm. The second acute angle A2 is less than the first acute angle A1. Although shown with the same angle A2, each of the first side arm 18 and the second side arm 20 can have a second acute angle with a different value.

[0179] The material of the device 10 is selected to provide the ability to elastically deform by the elastic bending described and to store potential energy, such as elastic energy, to return the device 10 to an unstressed position. Example materials include plastics (e.g., thermoplastics), composites, and nylon. Another example material is a polyether block amide, such as that available from Arkema, Inc. in King of Prussia, Pennsylvania, USA. Another example material is glass fiber reinforced polyamide. Example glass fiber reinforced polyamide is commercially available from Arkema, Inc. in King of Prussia, Pennsylvania, USA. BZM 70TL. This glass fiber-reinforced polyamide has a density of 1.07 grams per cubic centimeter under ISO 1183, an instantaneous hardness of 75 Shore D under ISO 868, a tensile modulus of 1800 MPa under ISO 527 (sample conditioned at 23 degrees Celsius and 50% relative humidity for 15 days), and a flexural modulus of 1500 MPa under ISO 178 (sample conditioned at 23 degrees Celsius and 50% relative humidity for 15 days).

[0180] Furthermore, the relative dimensions and shapes of the device at the joints and at the side arms 18, 20 contribute to the spring-biased nature of the device 10 and its ability to elastically deform under a desired load and return to its original, unstressed position. The device 10 can be configured to elastically bend under a force of up to 160 N. For example, referring to Figure 1 , first side arm 18 and second side arm 20 each have a thickness T1 at respective joints 24A, 24B that is greater than width W1. Thickness T1 is measured in the front-to-back (longitudinal) direction of footwear 12. Width W1 is measured in the medial-to-lateral (lateral) direction of footwear 12. Greater thickness T1 increases the force required to elastically bend device 10 into a loaded position.

[0181] Furthermore, the side arms 18 and 20 each twist outwardly along their respective longitudinal axes 23A, 23B from the joints 24A, 24B at the base to the central segment 16. In other words, the inwardly facing surface 60 of the side arms 18, 20 continuously extends to the slightly upwardly facing surface 62 as the ridge 64 along the side arm 18 or 20 turns from an upwardly extending ridge to a ridge extending partially rearwardly at the rear of the central segment 16. Figure 2 Similarly, the side surface 66 at the arm 18 or 20 extends into a slightly downwardly facing surface 68 below the ridge 64 at the central segment 16, as shown in FIG. Figure 1 This twisting in the side arms 18, 20 helps facilitate downward and rearward movement of the central section 16 during loading by the foot 46.

[0182] The device 10 is also configured to widen as it moves from the unstressed position to the loaded position. This helps facilitate insertion of the foot 46 into the flexible upper 38 as the first and second side arms 18, 20 flex away from each other when the control strip 14 is depressed, thereby pulling the upper 38 attached to the inwardly facing surface 60 outward. The flexion of the device 10 in the loaded position 10A is Figure 2 is shown in the plan view.

[0183] While the device 10 is thus configured to utilize its ability to resiliently deform and store elastic energy to facilitate foot entry, it is also configured to limit the amount of deformation to prevent plastic deformation. More specifically, the control strip 14 has an extension 70 that extends generally toward the base 22. When the control strip 14 is in Figure 1 In the unstressed position 10A, the extension 70 is spaced from the base 22 and contacts the base 22 when the control strip 14 is depressed and the device is in the loaded position 10A. Figure 3, extension 70 is designated 70A, with device 10 in loaded position 10A. Contact of extension 70 with base 22 limits further depression of control strip 14. Alternatively, base 22 may have an extension instead of or in addition to control strip 14, with the extension on the base extending toward control strip 14.

[0184] exist Figures 1 to 6 In the embodiment, the control strip 14 and the base 22 have complementary features that abut during depression of the control strip 14 to limit movement of the device. For example, the extension 70 abuts the base 22, thereby limiting depression of the control strip 14 and preventing it from tilting toward the lateral or medial sides during loading. More specifically, the base 22 has a recess 72, and when the control strip 14 is depressed and the device 10 elastically deforms to the loaded position 10A, the extension 70 protrudes into the recess 72 and contacts the base 22. While in the recess 72, side protrusions 74 on either side of the recess 72 prevent lateral movement of the extension 70. Because the control strip 14 typically descends along an arc when the joints 24A, 24B flex, the extension 70 is positioned so that it will abut against the base 22 in the recess 72 as it descends along this arc.

[0185] Figure 7 and Figure 8 Another embodiment of an article of footwear 112 having a heel spring device 110 is shown. Heel spring device 110 has similar functions and features as heel spring device 10. Joints 124A, 124B have a thickness T2 greater than thickness T1 of joints 24A, 24B and, therefore, can provide greater resistance to depression of control strip 14, thereby reducing the need for extension 70 to restrict flexion. Central segment 16 has an aperture 145, and upper 38 has a heel tab 149 extending through aperture 145, further securing upper 38 to device 110. After being inserted through aperture 145, heel tab 149 can be wrapped around device 110, can be left hanging loosely, or can be sewn or fastened to upper 38 or itself to secure upper 38 to device 10.

[0186] Figure 9 Another embodiment of an article of footwear 212 is shown having a heel spring device 210 secured to a sole layer 234. Heel spring device 210 has similar functions and features as heel spring device 10. An upper is not shown, but would be secured to sole layer 234 and device 210 as described with respect to device 10.

[0187] Figure 10Another embodiment of an article of footwear 312 is shown, which includes a heel spring device 310 secured to a sole structure 334, which is a midsole, and an upper 338, which includes a flexible cover layer comprising an elastically stretchable material in the heel region. Heel spring device 310 has similar functions and features to heel spring device 10. Heel spring device 310 may include a base 322, similar to base 22, but extending through sole structure 334, or base arms may terminate at sole structure 334 and be sufficiently secured thereto so that the sole structure functions as a base. Device 310 is integrated into the fastening system of upper 338 because it includes loops 339 secured to side arms that serve as anchors for fastening cables 343.

[0188] Figures 11 to 14 Another embodiment of an article of footwear 412 is shown, having a heel spring device 410 with similar functions and features to heel spring device 10. Heel spring device 410 is secured to a sole plate 434 and an upper 438. Upper 438 includes a flexible covering 442 made of an elastic, stretchable material in the heel region for receiving and covering the foot supported on sole plate 434. For example, flexible covering 442 may be an elastic, stretchable fabric, such as a four-way stretch nylon fabric. A foam collar 435 is secured to flexible covering 442 and defines a front portion of an ankle opening 439 in upper 438. The foam collar is stiffer than the elastic, stretchable fabric of flexible covering 442. Collar 435 may include foam padding 435A. Foam padding 435A at the rear portion of the collar may protrude inwardly into ankle opening 439. Because the foam is compressible, this allows the size of the opening to be adjusted to accommodate different ankle girths.

[0189] The central section of the control strip 414 of the device 410 has a thinned portion 445 where the flexible covering 442 of the upper 438 is sewn to the device 410. Figure 14 As shown in FIG, the foam collar 435 is also sewn to the device 410 at the thinned portion 445. Figure 12 As shown in FIG, another thin extension 441 of the device 410 extends along the side arms 418, 420 and is thin enough to allow the upper 438 to be sewn to the device 410 through the thin extension 441. The stitches 437 passing through the thinned portion 445 and through the extension 441 are Figure 13 and Figure 144. The upper 438 is characterized by the absence of a rigid heel stabilizer. Device 410 functions, at least in some respects, as a heel stabilizer because it helps maintain the wearer's heel in position atop the heel portion of the sole structure, thereby preventing medial or lateral displacement during use. Similar to device 10, device 410 has a ramped surface 450 for facilitating foot entry.

[0190] Figure 15 Another embodiment of an article of footwear 512 is shown, having a heel spring device 510 with similar functions and features to heel spring device 10. Heel spring device 510 is secured to a sole plate 534 and an upper 538. Upper 538 includes a flexible covering 542 made of elastic, stretchable material in the heel area for receiving and covering a foot supported on sole plate 534. When the foot is inserted, covering 542 expands to position 542A. For example, flexible covering 542 may be an elastic, stretchable fabric, such as a four-way stretch nylon fabric. Device 510 includes a forward-extending support member 511. The joints of device 510 are higher than those in other embodiments because they are located on the side of upper 538 above sole plate 534, as shown.

[0191] Figure 16 Another embodiment of an article of footwear 612 is shown having a heel spring device 610 having similar functions and features to heel spring device 10. Heel spring device 610 is secured to a sole plate 634 and an upper 638, which has a flexible covering of elastically stretchable material in the heel area for receiving and covering the foot supported on sole plate 634. For example, the flexible covering can be an elastically stretchable fabric, such as a four-way stretch nylon fabric. Sole plate 634 has molded recesses on its medial and lateral sides into which the base of device 610 and connectors, such as connector 624B, partially seat.

[0192] Figures 17 and 18 Another embodiment of an article of footwear 712 is shown that includes a heel spring device 710 having similar functions and features as heel spring device 10. Heel spring device 710 is embedded in a flexible covering of an upper 738 and is either secured at its base to a sole layer 734 by adhesive or other means, or is simply sandwiched between the midsole and the strobel or upper material to reduce the need for adhesives.

[0193] Figure 19Another embodiment of an article of footwear 812 is shown that includes a heel spring device 810 having similar functions and features as heel spring device 10. Heel spring device 810 is secured at its base to a sole layer 834 and to a flexible covering of an upper 838. A heel tab 849 secured to the upper forms a loop through which device 810 passes to reach behind the ankle opening, thereby helping to secure upper 838 for movement with device 810.

[0194] Figures 20 to 22 Another embodiment of an article of footwear 912 is shown, which includes a heel spring device 910 having similar functions and features as heel spring device 10. Heel spring device 910 is secured at its base to a sole layer (not shown) and to a flexible covering of an upper 938. Device 910 has a control strip 914 with side arms 918, 920, and a base 922 connecting side arms 918, 920 and positioned below control strip 914. Base 922 extends rearward from the junction 924A, 924B of control strip 914 and base 922 to serve as a support member. Base 922 will be positioned below the foot-receiving space in the upper to which heel spring device 910 is secured, and can be positioned below a drawstring in article of footwear 912. The base 922 can be secured to the sole by adhesive bonding or other means, or can simply be sandwiched between the sole and the upper or shoe material to reduce the need for adhesive. When the control strip 914 is depressed, the device 910 widens laterally outward, as shown by the device 910 in the loaded position 910A.

[0195] Figure 23 An example graph of vertical force F in Newtons on the vertical axis versus displacement D in millimeters on the horizontal axis is shown, schematically illustrating the elastic bending and energy return behavior of any heel spring device shown and described herein. Displacement D is, for example, Figure 3 The difference between the mid-distances D1 and D2. A first example representation of the behavior of the heel spring device is provided by the loading curve 1003 ( Figure 4 The placement of a force F on the control bar of the device (its vertical component is represented in the figure) is then illustrated by the unloaded curve 1002 (the behavior when force F is removed). A second example representation of the behavior of the heel spring device is shown by the loaded curve 1005 and the unloaded curve 1004.

[0196] Figures 24 to 25Another embodiment of an article of footwear 1012 is shown, including a heel spring device 1010 having similar functions and features to heel spring device 10. Heel spring device 1010 is secured at its base to a sole layer (not shown) and to a flexible covering of an upper 1038. Device 1010 has a control strip 1014 with side arms 1018, 1020, and a base 1022 connecting side arms 1018, 1020 and positioned below control strip 1014. Base 1022 extends rearwardly from the junction of control strip 1014 and base 1022 to serve as a support. Base 1022 can be positioned below a drawstring in article of footwear 1012, can be secured to the sole layer by adhesive bonding or other means, or can simply be sandwiched between the sole layer and the drawstring or upper material to reduce the need for adhesive. The side arms 1018, 1020 of the device 1010 are similar to the side arms 918, 920 of the device 910, except that the side arms 918, 920 extend from the base 922 to the central section of the control strip 914 at a gradually decreasing slope, as shown in FIG. Figure 21 As best shown in FIG, the side arms 1018, 1020 extend from the base 1022 to the central section of the control strip 1014 at a gradually increasing slope. Figure 25 Best shown in .

[0197] Figures 26 to 27 Another embodiment of an article of footwear 1112 is shown that includes a heel spring device 1110 having similar functions and features as the heel spring device 10. The heel spring device 1110 is secured at its base to a sole layer (not shown) and to a flexible covering of an upper 1138. The base 1122 can be located below the drawstring in the article of footwear 1112 and can be secured to the sole layer by bonding with an adhesive or other means, or can simply be sandwiched between the sole layer and the drawstring or upper material to reduce the need for adhesive. The device 1110 has a control strip 1114 with side arms 1118, 1120, and has a base 1122 connecting the side arms 1118, 1120 and located below the control strip 1114. The first side arm 1118 and the second side arm 1120 each have a Z-shape, as shown in FIG. Figure 27As best shown in FIG, they extend first rearward, then forward, and then rearward again as they advance from joints 1124A, 1124B to the central section of control strip 1114. The junction of the rearwardly extending portions with the forwardly extending portions of side arms 1118, 1120 can serve as an additional junction for elastic flexure induced by downward forces acting on the central section of control strip 1114 during loading of device 1110. Base 1122 extends rearwardly from the junction of control strip 1114 with base 1122 to serve as a support.

[0198] Figures 28 to 29 Another embodiment of a heel spring device 1210 for an article of footwear is shown. Heel spring device 1210 has a control strip 1214 including a medial arm 1218 and a lateral arm 1220. Control strip 1214 can be attached to a flexible footwear upper. A base 1222 extends from and supports control strip 1214. Unlike other embodiments of heel spring devices disclosed herein, base 1222 extends from a central segment of control strip 1214, with a junction between a generally vertical portion and a generally horizontal portion of base 1222.

[0199] Figures 30 to 31 Another embodiment of a heel spring device 1310 for an article of footwear is shown. Device 1310 has a control strip 1314 comprising a medial arm 1318 and a lateral arm 1320 extending from a central segment of control strip 1314. Control strip 1314 can be attached to a flexible footwear upper. The central segment has an aperture 1345 for receiving a heel tab of a flexible footwear upper or for sewing control strip 1314 to the footwear upper. The ends of lateral arms 1318, 1320 widen in the longitudinal direction and, together with the sole layer to which they are attached, serve as the base and joints 1324A, 1324B of device 1310.

[0200] Figure 32Another embodiment of an article of footwear 1412 is shown, including a heel spring device 1410 having similar functions and features to heel spring device 10. Heel spring device 1410 includes a control strip 1414 secured to a flexible cover of a footwear upper 1438. Control strip 1414 includes a medial arm and a lateral arm (one side arm 1420 is shown). Device 1410 includes a base (not shown) connected to the side arms and extending through an opening 1436 in a sole layer 1434 and being secured or embedded in the sole layer 1434. The base can be located below the drawstring in article of footwear 1412 and can be secured to the sole layer 1434 by adhesive bonding or other means, or it can simply be sandwiched between the sole layer 1434 and the drawstring or upper material, reducing the need for adhesive. Thus, the sole layer 1434 partially serves as the base and the interface with the control arm 1314.

[0201] Figure 33 Another embodiment of an article of footwear 1512 is shown, including a heel spring device 1510 having similar functions and features to heel spring device 10. Heel spring device 1510 has a control strip 1514 sewn to a flexible covering of a footwear upper 1538. Control strip 1514 includes a medial arm and a lateral arm (one side arm 1520 is shown). Device 1510 includes a base (not shown) connected to the side arms and extending through an opening in a sole layer 1534 and being embedded in or otherwise secured to the sole layer 1534. The base can be located below a drawstring in article of footwear 1512, can be secured to the sole layer 1534 by adhesive bonding or other means, or can simply be sandwiched between the sole layer 1534 and the drawstring or upper material to reduce the need for adhesive. Thus, the sole layer 1534 serves in part as a base for the control arm and a joint 1524 with the control arm.

[0202] Figures 34 to 35 Another embodiment of a heel spring device 1610 for an article of footwear is shown. The device 1610 has a control strip 1614 that includes a medial arm 1618 and a lateral arm 1620 extending from a central segment 1616 of the control strip 1614. The control strip 1614 is attachable to a flexible footwear upper. The central segment 1616 and the side arms 1618, 1620 have holes 1645 for sewing the device 1610 to the flexible footwear upper behind the ankle opening (such as at the rear collar of the ankle opening) to prevent the heel tab from folding inward in this area during foot insertion. The device 1610 does not have a base. However, the side arms 1618, 1620 can be secured near their distal ends to portions of the upper 1638, such as Figure 35, a slightly stiffer but resilient flexible portion 1635 is shown in the front of the four-way stretch fabric 1642 in the heel area. In this way, the stiffer portion 1635 of the upper effectively serves as a base for the device 1610 and forms a joint with the side arms 1618, 1620 to provide a springy return of the device 1610 to an unstressed position after downward force is applied during foot insertion.

[0203] Figure 36 Shown for Figures 37 and 38 Another embodiment of a heel spring device 1710 for an article of footwear 1712 is shown in FIG. Heel spring device 1710 has similar functions and features to heel spring device 10. Device 1710 has a control strip 1714 having a central segment 1716, a medial arm 1718, and a lateral arm 1720. Device 1710 has a continuous base 1722 connecting lateral arms 1718, 1720 and extending forward from the junction of control strip 1714 with base 1722.

[0204] like Figure 37 As shown in FIG, heel spring device 1710 is secured at its base 1722 to sole structure 1732 and to a flexible covering (shown in phantom) of footwear upper 1738. Upper 1738 defines at least a portion of foot-receiving space 1747 and ankle opening 1739. Base 1722 is located below foot-receiving space 1747 and can be located below the drawstring in article of footwear 1712. Base 1722 can be secured to sole structure 1732 by adhesive bonding or other means, or can simply be sandwiched between sole structure 1732 and the drawstring or upper material to reduce the need for adhesive. Base 1722 extends slightly rearward from the junction of control strip 1714 with base 1722 and extends forward from the junction with control strip 1714 to serve as a support. The base 1722 has a forwardly extending projection 1727 located adjacent a medial side 1741 of the footwear upper that underlies the foot-receiving void and a rearwardly extending projection 1729 located along a lateral side 1743 of the footwear upper that underlies the foot-receiving void.

[0205] Figure 37 The control strip 1714 is shown biased to an unstressed position. Figure 38 Control strip 1714 is shown elastically flexing to a loaded position under an applied force, thereby widening ankle opening 1739. Device 1710 stores elastic energy that returns control strip 1714 to an unstressed position when the applied load is removed.

[0206] Figures 39 to 40An article of footwear 1812 having a heel spring assembly 1810 is shown. Article of footwear 1812 and heel spring assembly 1810 are similar in many respects to article of footwear 1712 and heel spring assembly 1710, and like reference numerals are used to refer to like components. Heel spring assembly 1810 is similar in all respects to heel spring assembly 1710, except that heel spring assembly 1810 has a continuous base 1822 having a main portion 1831 and a protrusion 1833 extending downwardly from the main portion into a recess 1835 in a foot-facing surface 1837 of a sole structure 1732. Protrusion 1833 is configured to seat in recess 1835. The walls of protrusion 1833 abut against the walls of sole structure 1732 at recess 1835, thereby providing stability to base 1822. Additionally, protrusion 1833 forms a cavity 1839 within recess 1835, and this cavity may be used to house various footwear components or accessories, such as electronic accessories.

[0207] Figure 41 Shown for Figures 42 to 43 Another embodiment of a heel spring device 1910 for an article of footwear 1912 is shown in FIG. Heel spring device 1910 has similar functions and features to heel spring device 10. Device 1910 has a control strip 1914 with a medial arm 1918 and a lateral arm 1920. Device 1910 has a continuous base 1922 that connects lateral arms 1918, 1920 and extends forward and rearward from the junction of control strip 1914 and base 1922.

[0208] like Figure 42 , the heel spring device 1910 is secured at its base 1922 to the sole structure 1732 and to the flexible covering (shown in phantom) of the footwear upper 1738, both of which are referenced Figure 37 Base 1922 is located below foot-receiving space 1747 and can be located below the drawstring in article of footwear 1912 and can be secured to sole structure 1732 by adhesive bonding or other means, or can simply be sandwiched between sole structure 1732 and the drawstring or upper material to reduce the need for adhesive.

[0209] Medial arm 1918 and lateral arm 1920 each have at least one slot 1980 extending therethrough, and in the illustrated embodiment, multiple slots 1980 are provided. Slot 1980 extends through first side arm 1918 and extends lengthwise along the longitudinal axis of medial arm 1918 (i.e., along the length of side arm 1918). Separate slots 1980 extend through lateral arm 1920 and extend lengthwise along the longitudinal axis of lateral arm 1920 (i.e., along the length of side arm 1920). Slots 1980 reduce the thickness of side arms 1918, 1920, and thus reduce the force required to bend side arms 1918, 1920. More specifically, slots 1980 separate each side arm into a plurality of slats 1981 at the slot. Slats 1981 function as a plurality of thinner side arms that bend along their lengths in the region of slots 1980. Figure 42 The control strip 1914 is shown biased to an unstressed position. Figure 43 The control strip 1914 is shown elastically flexing under the applied force to a loaded position, which widens the ankle opening 1739 and tilts the ankle opening downward and rearward compared to the unloaded position. Figure 43 , in the loaded position, the side arms 1918, 1920 can be configured such that at least a portion of the slot 1980 is closed, causing the slats 1981 to contact each other, thereby increasing stiffness and resistance to further bending. The device 1910 stores elastic energy that causes the control strip 1914 to return to an unstressed position when the applied load is removed.

[0210] Figure 44 Shown for Figures 45 to 46 Another embodiment of a heel spring device 2010 for an article of footwear 2012 is shown in FIG. Heel spring device 2010 has similar functions and features as heel spring device 10. Device 2010 has a control strip 2014 with a medial arm 2018 and a lateral arm 2020. Device 2010 has a continuous base 2022 that connects the lateral arms 2018, 2020 and extends forward and rearward from the junction of control strip 2014 and base 2022.

[0211] like Figure 45 , the heel spring device 2010 is secured at its base 2022 to the sole structure 2032 and to the flexible covering of the upper 1738 (shown in phantom), both of which are referenced to FIG. Figure 37 Base 2022 is located below foot-receiving space 1747 and can be located below the drawstring in article of footwear 2012 and can be secured to sole structure 2032 by adhesive or other bonding methods, or can simply be sandwiched between sole structure 2032 and the drawstring or upper material to reduce the need for adhesive.

[0212] The medial arm 2018 and the lateral arm 2020 each have at least one slot 2080 extending therethrough, and in the illustrated embodiment, multiple slots 2080 are provided. The slot 2080 extends through the medial arm 2018 and is transverse to the longitudinal axis 23A of the medial arm 2018 (i.e., transverse to the length of the side arm 2018). Separate slots 2080 extend through the lateral arm 2020 and are transverse to the longitudinal axis 23B of the lateral arm 2020 (i.e., transverse to the length of the side arm 2020). The slots 2080 reduce the thickness of the side arms 2018, 2020 and, therefore, reduce the force required to bend the side arms 2018, 2020. More specifically, the slots 2080 divide each side arm into a plurality of fingers 2081 at the slot 2080. The fingers 2081 are used to reduce the thickness of the curved portion of the side arms 2018, 2020 to the thickness between the end 2083 of each slot 2080 and the upper surface 2085 of each side arm 2018, 2020, rather than the entire thickness of the side arm from the upper surface 2085 to the lower surface 2087. Figure 44 The middle is labeled relative to the lateral arm 2020, and the same applies to similar features of the medial arm 2018. Figure 45 The control strip 2014 is shown biased to an unstressed position. Figure 46 The control strip 2014 is shown being elastically bent to a loaded position under the action of an applied force, with the ankle opening 1739 being wider than in the unloaded position. Figure 46 As shown in , in the loaded position, the side arms 2018, 2020 can be configured such that at least a portion of the slot 2080 is closed, causing the fingers 2081 to contact each other, thereby increasing stiffness and resistance to further bending. The device 2010 stores elastic energy that causes the control strip 2014 to return to an unstressed position when the applied load is removed.

[0213] Figures 47 and 48 Another embodiment of a heel spring assembly 2110 is shown having the same features as the heel spring assembly 10 and Figure 27 The heel spring device has similar functions and features. Figure 48 , apparatus 2110 is shown in an article of footwear 2112 secured to a sole structure 2132 and a flexible covering of a footwear upper 2138 (shown in phantom), both of which are similar to those of reference 1. Figure 37Heel spring assembly 2110 is similar in all respects to heel spring assembly 1110 except that it has a base 2122 that extends both forwardly and rearwardly from the side arms 1118, 1120 of control bar 1114, as opposed to base 1122 that extends only rearwardly.

[0214] Figure 49 An article of footwear 2212 is shown having another embodiment of a heel spring device 2210. Heel spring device 2210 has similar functions and features as heel spring device 10. Device 2210 has a control strip 2214 having a medial arm 2218, a lateral arm 2220, and a central segment 2216 connecting lateral arms 2218, 2220, with the lateral arms extending generally downwardly and forwardly from central segment 2216. Similar to that described with respect to device 10 and article of footwear 12, device 2210 is secured to a flexible footwear upper 2238 and a sole structure 2232.

[0215] When footwear 2212 is in Figure 49 The pin 2290 is generally horizontally disposed when the shoe rests on the sole structure. The pin 2290 extends transversely through the sole structure 2232 and serves as a continuous base and is connected to the side arms 2218, 2220 at a first joint and a second joint. The pin 2290 is connected to the medial arm 2218 and the lateral arm 2220 where the medial arm 2218 and the lateral arm 2220 interface with the sole structure 2232. The pin 2290 establishes a pivot axis along the length of the pin 2290 (transverse to the sole structure 2232) about which the control arm 2214 pivots between an unstressed position and a loaded position. A biasing element, such as a torsion spring 2291, is wound around the pin 2290, one end of which is fixed to the pin 2290 and the other end of which is fixed to the sole structure 2232. For example, pin 2290 has a first end 2292 secured at the medial side of the sole structure and a second end 2294 secured to pin 2290. Control strip 2214 pivots to a loaded position to wind torsion spring 2291, thereby storing potential energy.

[0216] The control strip 2214 is biased to an unstressed position, shown in solid lines. When the device 2210 is pivoted to a loaded position under the action of an applied force, the control strip 1714 is shown in dashed lines as 2214A, in which the device is indicated as 2210A. The ankle opening 2739 widens in the loaded position and can tilt downward and rearward relative to the unloaded position because the flexible covering 2442 (also known as the flexible cover layer) of the upper 2238 is secured to the control strip 2214 and moves downward with the control strip 2214. The spring 2291 stores spring energy that returns the control strip 2214 to the unstressed position when the applied load is removed.

[0217] Figures 50 to 51 An article of footwear 2312 is shown having another embodiment of a heel spring device 2310. The heel spring device 2310 has similar functions and features as the heel spring device 10. The device 2310 has a control strip 2314 having a medial arm 2318 and a lateral arm (not shown, but a mirror image of the medial arm 2318). The device 2310 has a continuous base 2322 that connects the lateral arms and extends from the control strip 2314 to a base similar to the medial arm 2318. Figure 1 The joint of the base 2322 of the base 22 extends forward and backward.

[0218] like Figures 50 to 51 As shown in FIG, the heel spring device 2310 is secured at its base 2322 to the sole structure 32 and to the flexible covering of the footwear upper 38, both of which are referenced Figures 5 and 6 Describing.

[0219] The control strip 2314 has at least one slot 2380 that extends continuously from the first side arm 2318, across the central segment 2316, to the second side arm, and then through the first side arm 2318, across the central segment 2316, and through the second side arm (a mirror image of the slot shown). In the illustrated embodiment, there are multiple slots 2380. The same slot 2380 that extends through the first side arm 2318 and along its longitudinal axis (i.e., along its length) also extends through the second side arm and along its longitudinal axis (i.e., along its length). The slots 2380 reduce the thickness of the side arms and, therefore, reduce the force required to bend them. More specifically, the slots 2380 divide each side arm into a plurality of strips 2381 at the slot. The strips 2381 act as a plurality of thinner side arms that are bent along their length in the region of the slots 2380 .

[0220] Figure 50 The control strip 2314 is shown biased to an unstressed position. Figure 51 The control strip 2314 is shown elastically flexing under the applied force to a loaded position, which widens the ankle opening 39 and tilts the ankle opening downwardly and rearwardly compared to the unloaded position. Figure 51As shown in FIG, in the loaded position, side arm 2318 (and second side arm not shown) can be configured such that at least a portion of slot 2380 is closed, causing slats 2381 to contact each other, thereby increasing stiffness. However, when slats 2381 come into contact due to the closure of slot 2380, slats 2381 can slide against each other. This sliding allows further bending to continue at a reduced stiffness compared to a control strip similar to control strip 2314 but without the slot. Figure 51 A slight staggering is shown at the rear of the stack of slats 2381, indicating that they have slid relative to each other with the slot closed. The device 2310 stores elastic energy that causes the control strip 2314 to return to an unstressed position when the applied load is removed.

[0221] Figure 52 An article of footwear 2412 is shown having another embodiment of a heel spring device 2410. The heel spring device 2410 has similar functions and features to the heel spring device 10. The device 2410 has a control strip 2414 having a medial arm 18 and a lateral arm 20, and a central section 16 connecting the lateral arms 18, 20, with the lateral arms extending generally downwardly and forwardly from the central section 16. The device 2410 has reference Figure 1 A continuous base 22 is depicted connecting the side arms 18, 20 at a first joint 24A and a second joint 24B. Similar to as described with respect to device 10, device 2410 is secured to a flexible footwear upper 2438 and sole structure 2432.

[0222] The central segment 16 has an aperture 2445, and the upper 2438 has a heel tab 2449 that extends through the aperture 2445, further securing the upper 2438 to the device 2410. The central segment 16 also has an extension 2470 that extends downwardly from the central segment 16 and can limit the bending of the device 10 by interfering with the base 22, similar to that described with respect to the extension 70. The extension 2470 has a fastener opening 2451 that receives a stud (not shown) that can be used to secure the heel tab 2449 to the extension 2470 using a fastener, such as a cleat, snap, or button. Alternatively or additionally, the heel tab 2449 can be secured to a mounting surface 2472 of the extension 2470 using an adhesive or other means.

[0223] Figure 53An article of footwear 2512 is shown having another embodiment of a heel spring device 2510. The heel spring device 2510 has a rear control bar 2514 having a medial arm 2518 secured to the medial side of the footwear and a lateral arm (not shown) that is a mirror image of the medial arm 2518 but secured to the lateral side of the footwear 2512. The rear control bar 2514 also has a central section 2516 connecting the medial and lateral arms, and from which the lateral arms extend generally downward and forward. The device has a front bar 2515 that also has a medial arm, a lateral arm, and a central section 2516 connecting the medial and lateral arms. The flexible footwear upper 2538 is secured to the central segment 2516 of the front bar 2515, to the central segment 2416 of the rear control bar 2514, and to the medial and lateral arms of the rear control bar 2514 and the front bar 2515. Thus, the relative positions of the central segments 2416, 2516 determine the fore-aft expansion of the ankle opening 2539 formed by the upper 2538.

[0224] Strips 2514 and 2515 can be anchored to the sole structure 2532 at their ends. Strips 2514, 2515 are positioned to intersect each other on both the medial and lateral sides and are pivotally fixed to each other at connectors 2590 (one shown) on the lateral and medial sides where they intersect. Connector 2590 can be a pin joint. Torsion spring 2591 can be operably fixed to the connector. The upper portions of strips 2514, 2515 can be elastically bent so that when a force (such as the force of the foot entering the upper 2538) is applied to central segment 2416, central segments 2416 and 2516 can move in directions spaced apart from each other. The positions of central segments 2416, 2516 under load are shown in dashed lines as 2416A, 2516A. The device 2510 stores potential energy, such as elastic energy and / or spring energy, which causes the rear control strip 2514 to return to an unstressed position when the applied force is removed (i.e., after the foot slides into the foot-receiving cavity of the upper 2538).

[0225] Figure 54 An article of footwear 2612 is shown having another embodiment of a heel spring device 2610. The heel spring device 2610 has similar functions and features to the heel spring device 2310. The device 2610 has a control strip 2614 having a series of slats 2681 and a plurality of slots 2680, such as Figure 55 Each slat 2681 has a central segment 2616, an inner arm 2618 (at Figure 57) and lateral arms 2620. In one or more embodiments, the lateral arms 2620 and medial arms 2618 can be constructed to be mirror images of each other. The device 2610 has a continuous base 2622 that is located below the control strip 2614 and connects the lateral arms 2618, 2620 and extends from the control strip 2614 to a base similar to Figure 1 The base 22 of the base 2622 extends forward and backward. Figure 57 and Figure 58 As can be clearly seen in FIG, the device 2610 has a concave inner surface 2611 that has a concavity in both the medial-lateral direction and the vertical direction.

[0226] The article of footwear 2612 includes a sole structure 2632 and an upper 38 having a flexible covering (referenced to the Figures 5 and 6 Description). Heel spring device 2610 is secured to the flexible covering of footwear upper 38 via strap 2633 having chamber 2635, as shown in FIG. Figures 59 to 60 described.

[0227] like Figure 54 As shown in , the heel spring assembly 2610 is also secured to the sole structure 2632 at the base 2622 of the heel spring assembly 2610. Figures 55 to 56 As shown in FIG, the outer surface of the base 2622 of the device 2610 has a peripheral recess 2622A extending from the lower edge 2622B of the base 2622. The peripheral recess 2622A is Figure 55 、 Figure 56 It is shown on the outside of the base 2622 and extends around the inside of the base 2622 in a mirror image of the outside. Figure 54 The peripheral recess 2622A shown in FIG. 26 is shaped and sized to receive a flange 2632A of the sole structure 2632. The flange 2632A can be adhered or heat bonded to the base 2622 in the peripheral recess 2622A. The sole structure 2632 thus provides lateral support for the base 2622.

[0228] Control strip 2614 is biased to Figure 55 The unloaded position shown in FIG, and elastically bends under the action of the applied force F to Figure 56, each central segment 2616 is closer to the base 2622 in the loaded position than in the unloaded position, thereby storing potential energy that causes the control strip 2614 to return to the unloaded position when the applied force F is removed. The control strip 2614 and the base 2622 are constructed as full elliptical leaf springs. The device 2610 can be elastically flexible nylon or another elastically flexible material. The central segment 2616 is spaced from the base 2622 and the device 2610 is characterized by: a connection 2624A ( Figure 57 26 and a mirror image of joint 2624B) and at the rear of joint 2624B between lateral arm 2620 and base 2622, there is no rigid heel stabilizer located between central segment 2616 and base 2622. Device 2610 functions, at least in some respects, as a heel stabilizer in that it helps maintain the wearer's heel in position atop the heel portion of the sole structure, thereby preventing medial or lateral displacement during use.

[0229] like Figure 55 , the slots 2680 reduce the amount of material between the topmost one of the slats 2681B and the bottommost one of the slats 2681A at the side arms and, therefore, reduce the force required to bend the side arms. More specifically, by virtue of the slots 2680, the slats 2681 act as a plurality of thinner side arms that bend along their lengths in the region of the slots 2680. The bottommost one of the slats 2681A, which is closest to the base 2622 at the central segment 2616, is shorter from its inboard end 2682A to its outboard end 2683A than the topmost one of the slats 2681B, which is farthest from the base 2622. The inboard ends 2682A, 2682B are shorter than the topmost one of the slats 2681B, which is farthest from the base 2622. Figure 57 is represented in and is Figure 55 Mirror images of the outboard ends 2683A, 2683B shown in FIG.

[0230] In one or more embodiments, the lowermost slats 2681A are thinner than the uppermost slats 2681B at any location along their lengths between the inboard and outboard ends. Figure 55This is apparent in the exemplary embodiment by comparing the thickness T3 of the lowermost slat 2681A and the thickness T4 of the uppermost slat 2681B. In other words, although the thickness of slat 2681A may vary from its inboard end to its outboard end, and the thickness of slat 2681B may vary from its inboard end to its outboard end, at any given location between the inboard and outboard ends of slat 2681A, the thickness of slat 2681A will be less than the thickness of slat 2681B along a line perpendicular to the longitudinal axis of slat 2681A.

[0231] When the control bar 2614 is Figures 54 to 55 When in the unloaded position of the slats 2681, the slats 2681 are spaced apart from each other by the slots 2680. The slots 2680 are closed between the slats 2681 at least in some portions of the slots 2680 so that adjacent central segments 2616 are spaced apart from each other. Figure 56 In the embodiment shown, the slots 2680 are closed at the central segment 2616 in the loaded position, but may remain open at the side arms 2618, 2620. The slots 2680 are parallel to each other, and the outer sides 2644 of the slats 2681 are in contact with each other in the loaded position. Figure 55 The grooves 2680 enable the control strip 2614 to bend with less resistance (i.e., lower stiffness) than if the control strip 2614 had the same total thickness as the plurality of strips 2681 from the uppermost strip 2681B to the lowermost strip 2681A. Figure 55 In the exemplary embodiment of the present invention, when the slats 2681 come into contact due to the closure of the slots 2680, the slats 2681 can slide against each other (but not over each other). Compared to a control strip constructed in the manner of the control strip 2614 but without the slots, the sliding allows further bending to continue at a reduced stiffness. Figure 56 A slight staggering of the rear portions of the stacked slats 2681 is shown to illustrate that they slide relative to each other with the slots 2680 closed.

[0232] Figure 55 The control strip 2614 is shown biased to an unstressed (ie, unloaded) position. Figure 56 The control strip 2614 is shown elastically flexing under an applied force F (e.g., due to the foot sliding into the article of footwear) to a loaded position that causes the upper 38 to move with the control strip 2614 in the heel region, compared to the unloaded position. Figure 54When force F is applied, the heel area of ​​the upper 38 behind the ankle opening 39 moves with the central section 2616 of the control strip closer to the base 2622, causing the ankle opening 39 to expand or at least change the position of the ankle opening so that the ankle opening 39 can be tilted downward and rearward relative to the unloaded position, and the foot can enter from the rear, downward and forward rather than just downward, as by Figure 56 The location of the mid-ankle opening 39 is similar to Figure 55 The location of the mid-ankle opening 39 is comparatively best shown.

[0233] More specifically, upper 38 is connected to heel spring device 2610 via extension 2684 and a strap having chamber 2635. Figure 55 , the lowermost slat 2681A has an extension 2684 extending from a lower edge 2685 of the central segment 2616. The extension 2684 extends at least partially downward from the central segment 2616 and at least partially toward the base 2622. Figure 55 As shown in FIG, when the control arm 2614 is in the unloaded position, the extension 2684 extends downwardly and rearwardly. Figure 56 In the loaded position of the control arm 2614, the extension points straighter downward than in the unloaded position. Additionally, the control bar 2614 and the extension 2684 are configured to move away from the base 2622 so that when the control arm 2614 is in the loaded position, the extension is behind the base 2622. In such an embodiment, no recess is required in the base 2622.

[0234] refer to Figure 54 、 Figure 59 and Figure 60, the strap 2633 has a proximal end 2633A that is sewn, integrally formed, or otherwise connected to the upper 38 at the rear portion of the upper 38 near the ankle opening 39. The strap 2633 has a chamber 2635 at the distal end 2633B. The chamber 2635 can be formed, for example, by folding the strap 2633 over itself at the distal end 2633B and sewing the folded portion to the remainder of the strap 2633. The strap 2633 can extend downward from the upper 38. The strap 2633 is placed above and behind the control strip 2614, and the extension 2684 is then disposed in the chamber 2635, with the strap 2633 covering the central segment 2616. Thus, the extension 2684 and the strap 2633 serve to operably connect the upper 38 to the control strip 2614 so that the portion of the upper 38 rearward of the ankle opening 39 will move downwardly with the control strip 2614 to a loaded position, facilitating passage of the foot through the ankle opening 39 into the foot-receiving cavity of the upper 38, and then, when the force F is removed, move upwardly with the control strip back to the unloaded position, thereby placing the upper 38 around the rear of the foot that has been inserted into the foot-receiving cavity.

[0235] Figure 61 An article of footwear 2712 is shown having another embodiment of a heel spring device 2710. Like reference numbers are used to refer to like components as described with respect to article of footwear 2612 and heel spring device 2610. Heel spring device 2710 has similar functions and features as heel spring device 2610. Device 2710 has a control strip 2714 having a series of slats 2781 and a plurality of slats 2782 arranged in a substantially parallel relationship. Figure 63 Each slat 2781 has a central segment 2716, an inner arm 2718 (at Figure 62A best shown in Figure 61 The outer arm 2720 is best shown in FIG. The outer arm 2720 and the inner arm 2718 are mirror images of each other. The device 2710 has a continuous base 2622, as shown in FIG. Figure 54 and Figure 55 As depicted, the continuous base 2622 is located below the control strip 2714 and connects to the side arms, and extends rearward from the junction of the control strip 2714 and the base 2622. Figure 65 and Figure 66 As can be clearly seen in FIG, device 2710 has a concave inner surface 2711 that is concave in both the medial-lateral direction and the vertical direction.

[0236] The grooves 2780 reduce the amount of material between the uppermost one of the slats 2781B and the lowermost one of the slats 2781A at the side arms and thus reduce the amount of force required to bend the side arms via the force F applied to the central segment 2616. More specifically, due to the grooves 2780, the slats 2781 act as a plurality of thinner side arms that bend along their length in the region of the grooves 2780. Figure 61 and Figure 63 As shown in FIG, the lowermost slat 2781A of the slats 2781 closest to the base 2622 is shorter from its inner end 2782A to its outer end 2783A than the uppermost slat 2781B of the slats 2681 from its inner end 2782B to its outer end 2783B, wherein the uppermost slat 2781B is farthest from the base 2622. Figure 62A 2783A, 2783B are shown in FIG.

[0237] At any point along the bottom slat 2781A, the bottom slat 2781A is thinner than any of the other slats at a corresponding point (e.g., a point aligned directly above a point along the bottom slat), such as at Figure 63 . The thickness of the slats is measured along their longitudinal axis. Although the thickness of slat 2781A may vary along its longitudinal axis from its inboard end to its outboard end, and the thickness of slat 2781B may vary along its longitudinal axis from its inboard end to its outboard end, at any given point between the inboard and outboard ends of slat 2781A, the thickness of slat 2781A will be less than the thickness of slat 2781B at a point directly above that point along slat 2781A.

[0238] When the control bar 2714 is Figures 61 to 62A When in the unloaded position of the heel spring assembly 2710, the slats 2781 are spaced apart from each other by the slots 2780. The heel spring assembly 2710 includes an elastic insert 2790 that at least partially fills the slots 2780. The elastic insert 2790 may include an elastically compressible material such as at least one of rubber or thermoplastic polyurethane, and may be a foam, but is not limited to these materials. In the embodiment shown, the elastic insert 2790 is a thermoplastic polyurethane foam that provides compression stiffness and elastic resiliency. Figure 64 As best shown in FIG, the resilient insert 2790 includes a bushing 2791 having spaced apart projections 2792 extending outwardly on an outer surface 2793 of the bushing 2791. Figure 65As best shown in FIG, the bushing 2791 is configured to extend along the inside of the slats 2781 from the uppermost slat 2781B of the slats 2781 to the lower periphery of the base 2622. The outer periphery of the bushing 2791 coincides with the outer periphery of the slats 2781 and the base 2622.

[0239] Spaced apart projections 2792 extend from the bushing 2791 into the slots 2780 between the slats 2781. When the device 2710 is in Figure 61 and Figure 62A When in the unloaded position of the slats 2781, the spaced apart protrusions 2792 are shaped and sized to completely fill the slots 2780. In other embodiments, the spaced apart protrusions 2792 can be narrower than the slots 2780. The spaced apart protrusions 2792 can be flush with the outer surface of the slats 2781 or can extend outwardly beyond the outer surface of the slats 2781. The slats 2781 and the base 2622 can be referred to as a cage that supports the insert 2790.

[0240] When a downward force F is applied to the control bar 2714, the slot 2780 partially closes between the slats 2781, thereby moving the control bar 2714 to Figure 62B 2714 is partially compressed between the slats 2781. The sleeve 2791 is also compressed as the control strip 2714 moves downward. Because the sleeve 2791 and / or the slats 2781 are operably secured to the heel portion of the flexible covering of the upper 38 behind the ankle opening 39, the upper 38 moves downwardly with the sleeve 2791 and the control strip 2714 to the loaded position. Therefore, the amount of force required to move the device 2710 from the unloaded position to the loaded position depends on the bending stiffness of the control arm 2714 and the compressive stiffness of the elastic insert 2790 in the slot 2780. The compressive stiffness of insert 2790 is less than the bending stiffness of slats 2781, and therefore control strip 2714 is able to bend with a smaller force F than if multiple slats 2781 had the same total thickness from the topmost slat 2781B to the bottommost slat 2781A (i.e., if control strip 2714 had no slats).

[0241] Article of footwear 2712 includes sole structure 2632 and footwear upper 38 having a flexible covering. Heel spring device 2710 is secured to the flexible covering of footwear upper 38 by adhesive, stitching, heat bonding, or other means such that a rear portion of upper 38 rearward of ankle opening 39 moves with heel spring device 2710. Heel spring device 2710 is also secured to sole structure 2632 at its base 2622 by flange 2632A of sole structure 2632 secured in peripheral recess 2622A.

[0242] Control strip 2714 is biased to Figure 62A The unloaded position shown in FIG, and elastically bends under the action of the applied force F to Figure 62B . In the loaded position, each central segment 2716 is closer to the base 2622 than in the unloaded position due to the bending and storage of potential energy by the arms 2718, 2720. This potential energy causes the control strip 2714 to return to the unloaded position when the applied force F is removed. The control strip 2714 and the base 2622 are constructed as fully elliptical leaf springs. The strips 2781 and the base 2622 may be nylon or other resiliently flexible materials.

[0243] Figure 62A The control strip 2714 is shown biased to an unstressed (ie, unloaded) position. Figure 62B The control strip 2714 is shown elastically flexing under an applied force F (such as the force of a foot sliding into an article of footwear) to a loaded position that causes the upper 38 to move with the control strip 2714 in the heel region compared to the unloaded position. Figure 61 When force F is applied, the heel area of ​​the upper 38 behind the ankle opening 39 moves closer to the base 2622 as the central segment 2716 of the slat 2781 moves, causing the ankle opening 39 to expand or at least change position by lowering the upper 38 behind the ankle opening 39, so that the ankle opening 39 can be tilted downward and rearward relative to the unloaded position and can be used for entry of the foot moving downward and forward from the rear.

[0244] The slats 2781 and base 2622 can be injection molded. Once molded, the slats 2781 and base 2622 are a single, unitary component. The material of the foam insert 2790 can then be injected into the mold cavity containing the molded slats 2781 and base 2622. Figure 66 Holes 2794 are shown (only some of which are numbered) where pins hold the strips 2781 and base 2622 against the surface of the mold while the material of the insert 2790 is injected. The insert 2790 is molded around the ribs 2795 of the base 2622 near the junction of the strips 2781 and the base 2622, as shown by Figure 64 This is indicated by slot 2796 in insert 2790.

[0245] Figure 67An article of footwear 2712A is shown having another embodiment of a heel spring assembly 2710A. Heel spring assembly 2710A is similar in all respects to heel spring assembly 2710, except that insert 2790 has protrusions 2792A configured as accordions that extend outward from the inner side of slats 2781 and fill the grooves between slats 2781. Slats 2781 and base 2622 can be formed from semi-rigid or rigid thermoplastic polyurethane, while insert 2790 having protrusions 2792A can be formed from a softer thermoplastic polyurethane relative to slats 2781 and base 2622.

[0246] Figure 68 An article of footwear 2812 is shown having another embodiment of a heel spring assembly 2810. Like reference numerals are used to refer to like components as described with respect to article of footwear 2612 and heel spring assembly 2610. Heel spring assembly 2810 has similar functionality to heel spring assembly 2710, but includes a resilient bellows 2815 including a central segment 2816, a medial arm 2818 extending downwardly and forwardly from central segment 2816, and a medial arm 2818 extending downwardly and forwardly from central segment 2816. Figure 69 ), and lateral arms 2820 extending downwardly and forwardly from the central segment 2816 (best shown in Figure 68 ). The corrugations 2815 include alternating ridges 2881 and grooves 2880 extending lengthwise along the medial arm 2818, the central segment 2816, and the lateral arm 2820. Figure 70 and Figure 71A As is evident in FIG, device 2810 has a concave shape on the inner surface in both the medial-lateral direction and the vertical direction.

[0247] The corrugated body 2815 is biased to Figure 68 、 Figure 69 、 Figure 70 and Figure 71A The bellows 2815 is compressed to the unloaded position shown in FIG. Figure 71B . In the loaded position, the bellows 2815 compresses (e.g., by folding) such that adjacent ones of the alternating ridges 2881 are closer together than in the unloaded position, particularly at the central segment 2816, thereby storing elastic energy that returns the bellows 2815 to the unloaded position when the applied force F is removed. The upper 38 moves with the central segment 2816 such that when the heel spring device 2810 is in the loaded position, the ankle opening 39 can tilt downward and rearward relative to the unloaded position.

[0248] like Figure 68 , a first set of ridges 2881A and grooves 2880A extends from medial arm 2818 to lateral arm 2820, while a second set of ridges 2881B and grooves 2880B extends only along central segment 2816. The first and second sets are configured so that the ridges and grooves can follow the contour of upper 38, extending along the entire portion of upper 38 rearward of ankle opening 39, while still allowing some grooves and ridges (i.e., the first set) to extend downwardly and forwardly.

[0249] Reference Figure 69 , the device 2810 may include an upper flange 2823 extending along the upper edge 2825 of the corrugated body 2815 at the central segment 2816, and also include a lower flange 2822 extending along the lower edge 2827 of the corrugated body 2815 at the inner arm 2818, the central segment 2816 and the outer arm 2820.

[0250] The lower flange 2822 is also referred to as a base. The sole structure 2632 is fixed to the lower flange 2822 by adhesive, thermal bonding, or other means so that the sole structure 2632 is generally located below the upper 38 and the heel spring device 2810. Figure 68 As shown in Figure 69 , the outer surface of the base 2822 has a peripheral recess 2822A extending from a lower edge 2822B of the base 2822. The sole structure 2632 has a flange 2632A that is configured to seat within the peripheral recess 2822A. The flange 2632A of the sole structure 2632 provides lateral support for the heel spring device 2810.

[0251] If through Figure 68 As shown at stitches 2829 in FIG, upper flange 2823 is stitched to upper 38 behind ankle opening 39. Upper flange 2823 may optionally be adhered or heat bonded to upper 38. The connection of heel spring device 2810 to upper 38 via upper flange 2823 enables upper 38 to move with heel spring device 2810 between a loaded position and an unloaded position.

[0252] The ridges 2881 and grooves 2880 of the corrugated body 2815 may also be referred to as pleats. Ridges 2881 are the convex pleats of the pleats, while grooves 2880 are the concave folds of the pleats. Device 2810 is a single-piece, unitary component comprising the corrugated body 2815 and flanges 2822, 2823. Device 2810 may be injection molded from an elastically deformable material such as at least one of rubber or thermoplastic polyurethane, and may be a resilient foam (e.g., a polymer foam material, etc.), but is not limited to these materials.

[0253] Figure 72 Another embodiment of a heel spring assembly 2910 within the scope of the present teachings is shown. As described with respect to heel spring assembly 2710, heel spring assembly 2910 has spaced apart slats 2781 and a base 2622 and is biased to Figure 72 2780 . The heel spring assembly 2910 is shown in an unloaded position in the shoe, but elastically bends to a loaded position (not shown) in response to an applied load, which helps open the ankle opening of the upper to facilitate foot entry as described with respect to the heel spring assembly 2710. The heel spring assembly 2910 includes a discrete elastic insert 2990 that is disposed in the slot 2780, but only along a portion of the central segment 2716 (e.g., not disposed in the slots of the side arms). A strap 2991 is adhered or otherwise connected to the insert 2990 and the slats 2781 to hold the insert 2990 in place within the slot 2780. Alternatively, the strap 2991 can be an integral part of the elastic insert 2990, such that the elastic insert 2990 is integrated as a unitary component.

[0254] Figure 73 Another embodiment of a heel spring assembly 3010 is shown. As described with respect to heel spring assembly 2710, heel spring assembly 3010 has spaced apart slats 2781 and base 2622 and is biased to Figure 73 2781, but resiliently flexes to a loaded position (not shown), which helps open the ankle opening of the shoe upper to facilitate foot entry as described with respect to heel spring device 2710. Heel spring device 3010 has a pair of middle slats 3083 arranged as elliptical springs between base 2622 and a middle one of slats 2781, and connected to base 2622 and middle slats 2781, respectively. Heel spring device 3010 also has a pair of middle slats 3085 arranged as elliptical springs between the uppermost slat and a middle one of slats 2781, and connected to the uppermost slat and the middle slat, respectively. Middle slats 3083, 3085 provide additional resistance to flexion and store elastic energy to return heel spring device 3010 to the unloaded position when the applied load is removed. The arrangement of slats 2781 and intermediate slats 3083, 3085 may be referred to as a lattice.

[0255] Figure 74An article of footwear 3112 is shown having another embodiment of a heel spring arrangement 3110. Like reference numerals are used to refer to like components as described with respect to article of footwear 2612 and heel spring arrangement 2610. Heel spring arrangement 3110 has similar functionality to heel spring arrangement 2610, but includes a fluid-filled bladder 3115 comprising a central segment 3116, a medial arm 3118 (shown in FIG. 1 ) extending downwardly and forwardly from central segment 3116, and a heel spring arrangement 3110 (shown in FIG. 1 ). Figure 75 ), and lateral arms 3120 extending downwardly and forwardly from central segment 3116. Sole structure 2632 is secured to lower flange 3122 of bladder member 3115 by adhesive, thermal bonding, or other means such that sole structure 2632 is generally located below upper 38 and heel spring device 3110, as shown. Figure 74 As shown in .

[0256] Applying a downward force F on the central segment 3116 moves the bladder member 3115 from the unloaded position ( Figure 77 )Move to the loading position( Figure 78 ). The unloaded position is also referred to as the expanded position, while the loaded position is also referred to as the collapsed or compressed position. The central segment 3116 may be referred to as a control strip.

[0257] The bladder member 3115 can be thermoformed from a first polymer sheet 3117 and a second polymer sheet 3119 ( Figure 76 1 and 2, and also referred to as inner and outer sheets, or inner and outer layers, respectively). Alternatively, the bladder member 3115 can be blow molded from a preformed polymer material. The bladder member 3115 can be formed from any of a variety of polymer materials that maintain a fluid at a predetermined pressure, including fluids that are gases such as air, nitrogen, or other gases. As used herein, "fluid" includes gases, including air, inert gases such as nitrogen, or other gases. Thus, "fluid-filled" includes "gas-filled."

[0258] For example, bladder member 3115 can be made of a TPU material, polyurethane, polyurethane, polyester, polyester polyurethane, and / or polyether polyurethane. Furthermore, in one embodiment, bladder member 3115 can be formed from a sheet having layers of different materials. Sheets 3117, 3119 can be laminated films formed from a film having one or more first layers comprising a thermoplastic polyurethane layer alternating with one or more second layers, also referred to herein as barrier layers, gas barrier polymers, or gas barrier layers. The second layer can comprise a copolymer of ethylene and vinyl alcohol (EVOH), which is impermeable to the pressurized fluid contained therein, as disclosed in U.S. Patent No. 6,082,025 to Bonk et al., the entire contents of which are incorporated herein by reference. The first layer can be arranged to form the outer surface of the polymer sheet. That is, the outermost first layer can be the outer surface of bladder member 3115. As disclosed in U.S. Pat. Nos. 5,713,141 and 5,952,065 to Mitchell et al., the bladder member 3115 can also be formed from a material comprising alternating layers of thermoplastic polyurethane and ethylene-vinyl alcohol copolymer. Alternatively, the layers can include ethylene-vinyl alcohol copolymer, thermoplastic polyurethane, and regrind material of ethylene-vinyl alcohol copolymer and thermoplastic polyurethane. The sheets 3117, 3119 can have alternating layers of thermoplastic polyurethane (TPU) and a gas barrier material. In the embodiment shown, the sheets 3117, 3119 are transparent.

[0259] The sheets 3117, 3119 are joined to one another at the periphery of the bladder member 3115, such as at an upper flange 3123 and a lower flange 3122, also referred to as a base. The lower flange 3122 is continuous and connects and supports the medial arm 3118, the central segment 3116, and the lateral arm 3120. The sheets 3117, 3119 are also joined to one another at various intermediate joining locations 3124, referred to as webbing. Figure 74 , the upper flange 3123 is thermally bonded, adhered, or otherwise secured to the upper 38 behind the ankle opening 39. The upper 38 can also be secured to the inner surface of the first polymer sheet 3117 between the upper flange 3123 and the lower flange 3122. The connection of the heel spring device 3110 to the upper 38 via the upper flange 3123 enables the upper 38 to move with the heel spring device 3110 between a loaded position and an unloaded position. More specifically, the upper 38 moves with the central segment 3116 so that when the heel spring device 3110 is in the loaded position, the ankle opening 39 can be tilted downward and rearward relative to the unloaded position, enabling hands-free entry of the foot.

[0260] The combined sheets 3117, 3119 form a plurality of fluid-filled interior cavities 3181A, 3181B, 3181C, 3183A, and 3183B that are fluid-tight and can be pressurized or unpressurized. In the illustrated embodiment, the fluid-filled interior cavities 3181A, 3181B, 3181C, 3183A, and 3183B are at the ambient pressure of the environment in which the fluid-filled cavity is sealed. Alternatively, the fluid-filled interior cavities 3181A, 3181B, 3181C, 3183A, and 3183B can be pressurized by introducing fluid into the cavity through one or more inflation ports (not shown) that are subsequently sealed.

[0261] In the illustrated embodiment, each of the fluid-filled interior cavities 3181A, 3181B, and 3181C is generally tubular and extends lengthwise along the medial arm 3118, the central segment 3116, and the lateral arm 3120. In some embodiments, the cavities 3181A, 3181B, 3181C extend only along the central segment 3116. The cavities 3181A, 3181B, 3181C may be referred to as elongated cavities or tubular cavities. Alternatively, fluid-filled cavities of other shapes may extend along the central segment 3116 and may also extend along one or both of the medial and lateral arms. For example, a plurality of discrete cavities may be shaped as tubes shorter than the cavities 3181A, 3181B, 3181C, or have other shapes, may extend along the central segment 3116, and may be fluidically interconnected to one another via channels formed by the sheet.

[0262] The tubular lumens 3181A, 3181B, and 3181C are connected to and in fluid communication with the fluid-filled inner lumens 3183A, 3183B, which can be referred to as inner reservoirs 3183A and outer reservoirs 3183B. In this manner, the tubular lumens 3181A, 3181B, and 3181C are in indirect fluid communication with each other via the reservoirs 3183A, 3183B. In some embodiments, a channel extending directly between adjacent tubular lumens 3181A, 3181B, and 3181C can also be provided so that the tubular lumens 3181A, 3181B, and 3181C are in direct fluid communication with each other. In some embodiments, only one of the reservoirs 3183A, 3183B is provided, or no reservoir is provided, and the tubular lumens 3181A, 3181B, and 3181C simply terminate at a side arm without a reservoir. In other embodiments, each lumen may have its own separate reservoir on one or both side arms. Reservoirs 3183A, 3183B are formed by first and second polymer sheets 3117, 3119 at the inner and outer ends of the lumen 3181A, 3181B, and 3181C, respectively. Figures 74 to 75As can be clearly seen in FIG, device 3110 has a concave shape on the inner surface of the first polymer sheet in both the medial-lateral direction and the vertical direction.

[0263] The formed sheets 3117, 3119 with internal cavities 3181A, 3181B, 3181C, 3183A, 3183B bias the heel spring device 3110 to Figures 74 to 77 The heel spring assembly 3110 is compressed to the unloaded position shown in FIG. Figure 78 3181C, thereby storing elastic energy. For example, the applied force F may be the force of the foot when the foot is inserted into ankle opening 39 of article of footwear 3112. In the loaded position, bladder member 3115 resiliently deforms because force F is applied generally above central segment 3116 of tubular cavities 3181A, 3181B, and 3181C, such that the top of central segment 3116 is closer to flange 3122 in the loaded position than in the unloaded position.

[0264] When the tubular lumens 3181A, 3181B, and 3181C are compressed, some of the fluid within the fluid-filled interior lumens 3181A, 3181B, and 3181C may be transferred to the reservoirs 3183A, 3183B, causing the reservoirs to expand and bulge outward, as shown. Figure 78 When the force F is removed, the resiliently deformed bladder member 3115 returns to the tubular cavities 3181A, 3181B, and 3181C as the transferred fluid returns from the reservoirs 3183A, 3183B. Figure 77 to an unloaded position, thereby expanding the tubular lumens 3181A, 3181B, 3181C to their original shapes and reducing the size of the reservoirs 3183A, 3183B to their original shapes.

[0265] Figure 79 Shown for Figures 80 to 82 Another embodiment of a heel spring device 3210 for an article of footwear 3212 is shown in FIG. Heel spring device 3210 has similar functions and features to heel spring device 10. For example, device 3210 has a control strip 14 with a medial arm 18 and a lateral arm 20. Device 3210 has a continuous base 22 connecting lateral arms 18, 20 and extending rearwardly from the junction of control strip 14 and base 22. Base 22 is positioned below control strip 14, with first lateral arm 18 positioned on medial side 41 of footwear upper 38, second lateral arm 20 positioned on lateral side 43 of footwear upper 38, and central segment 16 of control strip 14 positioned rearwardly of ankle opening 39 of upper 38.

[0266] The base 22 supports the control strip 14 and is connected to the control strip 14 at resiliently flexible joints 3224A, 3224B. The base 22 is continuous and extends between and connects to the first and second side arms 18, 20. The base 22 is continuous because it extends from the first side arm 18 to the second side arm 20 without interruption or connection through other components. The base 22 has a central section 26, a first base arm 28, and a second base arm 30, all of which are arranged in a common plane, as shown in FIG. Figure 3 The first base arm 28 is spaced apart from the second base arm 30 and both extend from the central section 26 of the base 22.

[0267] Joints 3224A and 3224B include a first joint 3224A at which the base 22 and first side arm 18 are connected, and a second joint 3224B at which the base 22 and second side arm 20 are connected. The first joint 3224A connects the first base arm 28 and the first side arm 18. The second joint 3224B connects the second base arm 30 and the second side arm 20. Joints 3224A and 3224B may be referred to herein as hinged joints or hinged joints.

[0268] Control strip 14 has an arcuate shape from first joint 3224A to second joint 3224B. Similarly, base 22 has an arcuate shape from first joint 3224A to second joint 3224B. With this arrangement, control strip 14 and base 22 are configured as a fully elliptical leaf spring as described herein. Device 3210 can be referred to as a heel spring. Furthermore, device 3210 is a single, unitary, one-piece component. For example, device 3210 can be injection molded as a single, unitary, one-piece component.

[0269] The central segment 16 of the control strip 14 has a ramp surface 50 that slopes toward the inner periphery of the central segment 16 between the first and second side arms 18, 20 and, as described with respect to the device 10, helps guide the foot downwardly and forwardly into the foot-receiving cavity 47 during application of the downward force F on the control strip 16. In addition, the first and second side arms 18, 20 each twist outwardly along their respective longitudinal axes from the junction 3224A, 3224B near the base 22 to the central segment 16 of the control strip 14. This outward twisting helps facilitate downward and rearward movement of the central segment 16 during loading of the foot.

[0270] Article of footwear 3212 includes a sole structure 3232, and a flexible footwear upper 38 having a medial side 41 and a lateral side 43, and defining an ankle opening 39 and a foot-receiving cavity 47, as described with respect to article of footwear 12. Sole structure 3232 includes one or more sole components, which may be a sole layer, such as an outsole, a midsole, or a sole layer 3234, which is a unitary combination of an outsole and a midsole and may be referred to as a unisole. Sole layer 3234 is located below upper 38 and the foot-receiving cavity 47 defined by upper 38. Lower portion 40 of footwear upper 38 is secured to sole layer 3234, such as by adhesive or other means. Base 22 is secured to sole layer 3234, such as by bonding using adhesive, heat bonding, or other means.

[0271] like Figure 83 , the sole layer 3234 has a slight recess 3219 in the outer wall 3217 of the sole layer 3234 (i.e., in the outer sidewall and rear wall in the heel area of ​​the sole layer 3234). The recess 3219 is shaped to allow the base 22 and joints 3224A, 3224B to partially seat in the recess 3219. The portions of the base 22 and joints 3224A, 3224B that are seated in the recess 3219 are secured to the outer wall 3217 of the sole layer 3234 in the recess 3219. Thus, the device 3210 is supported by the sole layer 3234 in the recess 3219.

[0272] The control strip 14 is biased to Figure 80 and Figure 82 . The unloaded position is also referred to herein as the stress-free position. The control strip 14 is internally biased to the stress-free position in its formed state due to its material. In other words, the material of the control strip 14 has sufficient rigidity so that in the absence of an external load applied thereto, it remains in the stress-free position in its natural state and, due to its elasticity, will return to the stress-free position after elastic bending. In the stress-free position, the central segment 16 is a first distance D1 from the bottom of the central segment 26 of the base 22, as shown in FIG. Figure 80 The unstressed position is represented by the distance D1 from the top of the central segment 16 of the control strip 14 to the bottom of the central segment 26 of the base 22. The unstressed position is the position where the device 3210 is in a relaxed, unloaded state (i.e., no vertical force is applied to the control strip 14). The control strip 14 can be Figure 80 , which represents the force F of the foot being pressed downwardly when the foot is inserted into the foot-receiving cavity 47 of the article of footwear 3212 (e.g., see Figure 5 and Figure 6) during the foot. When loaded in this manner, the control strip 14 elastically bends to a loaded position in which the top of the central segment 16 is a second distance D2 from the bottom of the central segment 26 of the base 22. The loaded position is shown at Figure 80 In the figure, the control strip 14 and the central segment 16 are shown in dashed lines, and the central segment is shown in Figure 80 denoted by reference numeral 16A. The second distance D2 is greater than the first distance D1. The difference between distances D1 and D2 is the deflection of device 3210, which may be, but is not limited to, 30 mm. Device 3210 is configured such that when it is depressed to loaded position D2 under the action of force F, it elastically bends at joints 3224A, 3224B, thereby storing elastic energy. When force F is removed, the stored elastic energy causes control strip 14 to return to its unstressed position. Similar to device 10, when control strip 14 is in the unloaded position, first side arm 18 and second side arm 20 extend at a first acute angle A1 relative to a common plane P of base 22. When control strip 14 is depressed, first side arm 18 and second side arm 20 extend at a second acute angle A2 relative to the common plane P of base 22. Second acute angle A2 is less than first acute angle A1.

[0273] like Figure 82 As best shown in FIG, base 22 extends from lateral side 43 to medial side 41 around the rearmost portion of footwear upper 38. Figure 82 , device 3210 is not secured to upper 38 at medial side 41 or lateral side 43. Instead, device 3210 is secured to upper 38 only via heel tab 3249, which extends through aperture 3245 in central segment 16. Next, tab 3249 is stitched to rear portion 3247 of upper 38 at stitch line 3241. Decorative buckle 3243 may be secured to tab 3249. However, in the embodiment shown, decorative buckle 3243 is merely decorative, as it does not snap or otherwise fasten to upper 38.

[0274] Figure 84 As best shown, medial arm 18 and lateral arm 20 are asymmetrical about a longitudinal axis L extending between medial arm 18 and lateral arm 20 through base 22. Medial arm 18 is also referred to herein as a first side arm, and lateral arm 20 is also referred to herein as a second side arm. Medial arm 18 can be shorter than lateral arm 20 and can have a greater lateral (i.e., outward) curvature than the lateral arm, similar to the shape of a typical heel area of ​​a foot. Because heel device 3210 is asymmetrically shaped in this manner to follow the typical foot shape, pressure of heel device 3210 against the sides of the foot during wear is thereby minimized.

[0275] Figures 85 to 86Another embodiment of a heel spring assembly 3310 is shown having many of the same features as the heel spring assembly 10, 3210, which are indicated by like reference numerals. In addition, the base 22 has an inwardly extending flange 3221 that extends continuously from the inner base side arm 28 around the central segment 26 to the outer base side arm 30, such that the flange 3221 has a generally U-shape.

[0276] refer to Figure 87 , a heel spring device 3310 is included in an article of footwear 3312 having an upper 38 and a sole structure 3332. Upper 38 is as described herein with respect to heel spring device 10, and Figure 87 The sole structure 3332 includes an outer sole layer 3334 that can serve as an integral outsole and midsole. The sole structure 3332 also includes an inner sole layer 3345 that covers the sole layer 3334, also referred to as an insole. Figure 89 A sole layer 3334 is shown with the inner sole layer 3345 removed. The sole layer 3334 has a recess 3349 in an upper surface 3347. The recess 3349 is shaped so that the flange 3221 is located and at least partially seated in the recess 3349 and is secured to the upper surface 3347 of the sole structure 3332 in the heel area. Figure 90 The flange 3221 is shown positioned in the recess 3349. The heel spring device 3310 is secured to the sole layer 3334 by heat bonding, adhesive, or other means to secure the flange 3221 to the upper surface 3347 of the sole layer 3334 in the recess 3349. The inner sole layer 3345 is then inserted into the upper 38 to rest on the sole layer 3334 above the flange 3221 and at the upper surface 3347 of the sole layer 3334.

[0277] like Figure 90 , heel spring device 3310 is asymmetrical about longitudinal axis L. More specifically, medial arm 18 curves laterally outwardly beyond lateral arm 20 and is also longer in the anterior-posterior direction (along longitudinal axis L) than lateral arm 20. As discussed with respect to heel spring device 3210, this is a more anatomical shape than a symmetrical heel spring device and avoids undesirable friction and pressure of lateral arms 18, 20 on the foot.

[0278] The heel spring device 3310 is configured to be secured to the upper 38 at the forward-most portion of the side arms 18, 20 and via a heel tab extending through the aperture 3245 of the central segment 16, as shown. Figure 873376. In some embodiments, the upper 38 may be secured to the first side arm 18 at the medial recess 3374 and to the second side arm 20 at the lateral recess 3376. For example, the upper 38 may be joined to the side arms 18, 20 at the recesses 3374, 3376. In some embodiments, as shown in FIG. Figure 88 As shown in , the upper may include an inner portion 38B and an outer portion 38A. In such an embodiment, the outer portion 38A may include a rearwardly extending flange 38C that is thinner than a more forward portion of the outer portion 38A. The flange 38C engages and is secured to the inner surfaces 3373, 3377 of the side arms 18, 20 in recesses 3374, 3376. The outer portion 38A may be less flexible than the inner portion 38B and, therefore, may provide better anchoring support for the device 3310 at the arms 18, 20 than the inner portion 38B.

[0279] In addition to being attached to the upper 38 (or outer portion 38A) at the front-most portions 3371, 3375, the upper 38 may also be attached to the upper 38 via the heel tab 3249 (see FIG. Figure 87 and Figure 91 ) is fixed to the heel spring device 3310. The heel tab 3249 extends through the hole 3245 in the central segment 16. After the tab 3249 extends through the hole 3245, the tab 3249 can be folded into a loop and Figure 92 3285 is sutured to itself at the suture 3285 shown in FIG. The pin 3283 can then be inserted into the opening 3281 in the loop of the tab 3249. The pin 3283 can be secured to the tab 3249 in the opening 3281 behind the hole 3245, such as by inserting an adhesive into the opening 3281. The tab 3249 with the pin 3283 therein can be wider than the hole 3245. For example, the pin 3283 has a width 3286 (see FIG. 3287 ) that is greater than the width 3287 of the hole 3245. Figure 91 ). As the pin 3283 is inserted into the looped tab 3249, after the tab 3249 is pulled through the hole 3245, the pin 3283 helps to maintain the tab 3249 in a position extending through the hole 3245, and thus helps to secure the upper 38 to the device 3310 via the tab 3249. The tab 3249 is thus anchored to the central segment 16 by the pin 3283.

[0280] Figures 93 to 94A heel spring assembly 3410 is shown having many of the same features as the heel spring assemblies 10 and 3210. Similar reference numerals are used to refer to these features. The assembly 3410 includes a lever 3489 extending laterally outward from the control strip 14. The lever 3489 may also be referred to as a ledge extension or shelf. The lever 3489 is disposed partially along the medial arm 18 and partially along the central segment 16. The lever 3489 may be disposed anywhere along the control strip 14 within the scope of the present disclosure. The lever 3489 has an upwardly facing surface 3491 that may be positioned in a manner similar to that of the inner arm 18 and the central segment 16. Figure 80 The lever 3489 is depressed downwardly in a manner similar to that described above with respect to the force F acting on the central segment 16 in FIG. The depression lever 3489 assists in depressing the control strip 14 from the unstressed position to the stressed position. The surface 3491 has a concave groove 3493, making the surface 3491 uneven, thereby enhancing the ability to grip the surface 3491 when the lever 3489 is depressed. Figure 94 A rear view of an article of footwear 3412 is shown, which includes a device 3410 secured to a sole layer 3434 and an upper 38.

[0281] The various embodiments of the heel spring apparatus disclosed herein enhance the ease of foot entry, allowing the foot to be entered into an article of footwear without hands lifting.

[0282] The following clauses provide example constructions of the articles of footwear, apparatus, and footwear uppers disclosed herein.

[0283] Item 1: A device configured to enclose a portion of a foot-receiving cavity in a heel region of an article of footwear, the device comprising a control strip having a central segment, a first side arm extending from the central segment, and a second side arm spaced apart from the first side arm and extending from the central segment; a continuous base supporting the control strip and connected to both the first side arm and the second side arm; and wherein the control strip is biased to an unstressed position in which the central segment is a first distance from the base, the control strip elastically deforms under an applied force to a loaded position in which the central segment is a second distance from the base less than the first distance, and the device stores potential energy that causes the control strip to return to the unstressed position when the applied load is removed.

[0284] Clause 2: The device of clause 1, wherein the base is connected to the first side arm at a first joint, and the base is connected to the second side arm at a second joint.

[0285] Clause 3: The device according to clause 2, wherein: the control strip has an arcuate shape from the first joint to the second joint; the base has an arcuate shape from the first joint to the second joint; and the control strip and the base are constructed as full-elliptical leaf springs.

[0286] Clause 4: An apparatus according to any one of clauses 2 to 3, wherein: the base has a central section, a first base arm and a second base arm all arranged in a common plane; the first base arm is spaced apart from the second base arm, and both extend from the central section of the base; the first base arm and the first side arm are connected at the first joint; the second base arm and the second side arm are connected at the second joint; when the control strip is in the unstressed position, the first side arm and the second side arm extend at an acute angle relative to the common plane of the base; when the control strip is in the loaded position, the first side arm and the second side arm extend at a second acute angle relative to the common plane of the base; and the second acute angle is smaller than the first acute angle.

[0287] Clause 5: The device of any one of clauses 1 to 4, wherein the central segment of the control strip has a ramp surface that slopes toward an inner periphery of the central segment between the first and second side arms.

[0288] Clause 6: The device of any one of clauses 1 to 5, wherein the first and second side arms each twist outwardly along their respective longitudinal axes from the base to a central section of the control strip.

[0289] Clause 7: The device of any one of clauses 1 to 6, wherein the first and second side arms are asymmetrical about a longitudinal axis extending through the base between the first and second side arms.

[0290] Clause 8: The device of any one of clauses 1 to 7, wherein the base has an inwardly extending flange.

[0291] Clause 9: The apparatus of clause 8 in combination with a sole structure having a foot-receiving surface with a recess in a heel region; and wherein the flange is seated in the recess and secured to the foot-receiving surface.

[0292] Clause 10: A device according to any one of clauses 1 to 7, in combination with a sole structure having an outer wall with a recess in the heel area; and wherein the base of the device is at least partially seated in the recess and is fixed to the outer wall of the sole structure.

[0293] Clause 11: The apparatus of any one of clauses 1 to 10, in combination with a footwear upper that defines at least a portion of an ankle opening, wherein the base is located below the control strip, the first side arm is located at the medial side of the upper, the second side arm is located at the lateral side of the upper, and the central segment of the control strip is located rearward of the ankle opening.

[0294] Item 12: An apparatus according to Item 11, wherein the frontmost portion of the inner surface of the first side arm includes a medial recess, such that the first side arm is thinner at the medial recess than behind the medial recess, and the frontmost portion of the inner surface of the second side arm includes a lateral recess, such that the second side arm is thinner at the lateral recess than behind the lateral recess; and wherein the upper is secured to the second side arm at the lateral recess and to the first side arm at the medial recess.

[0295] Clause 13: The apparatus of any one of clauses 1 to 12, wherein the central segment has an aperture; and wherein the upper includes a tab extending through the aperture.

[0296] Clause 14: The apparatus of Clause 13, wherein the tab is secured to a rear portion of the footwear upper.

[0297] Clause 15: The device of clause 13, further comprising a pin secured to the tab behind the hole, wherein the tab with the pin thereon is wider than the hole such that the tab is anchored to the central segment by the pin.

[0298] Clause 16: The device of any one of clauses 1 to 15, further comprising: a lever extending outwardly from the control strip.

[0299] Clause 17: The device of any one of clauses 1 to 16, wherein the first side arm and the second side arm each have at least one slot extending therethrough.

[0300] Clause 18: An apparatus according to clause 17, wherein the control strip comprises a series of slats, each slat extending along the first side arm, the central segment and the second side arm, and wherein the at least one slot comprises a series of slots, each slot extending along the first side arm, the central segment and the second side arm and being arranged between corresponding adjacent slats in the slats.

[0301] Clause 19: The device of any one of clauses 1 to 16, wherein the device comprises a bladder member comprising one or more fluid-filled interior cavities.

[0302] Clause 20: A device according to clause 19, wherein: the one or more fluid-filled internal cavities include: a cavity extending along the central segment; and one or more reservoirs, the one or more reservoirs being disposed at one or both of the first side arm and the second side arm and being in fluid communication with the cavity extending along the central segment; and when the heel spring device is elastically deformed under the action of the applied force, the one or more reservoirs expand as fluid is transferred from the cavity extending along the central segment.

[0303] Clause 21: The device of any one of clauses 1 to 18, wherein the first and second side arms are bent away from each other when the control strip is in the loaded position.

[0304] Clause 22: A device according to any one of clauses 1 to 18, wherein: one of the control strip and the base has an extension extending toward the other of the control strip and the base; and when the control strip is in the unstressed position, the extension is spaced apart from the other of the control strip and the base, and when the control strip is in the loaded position, the extension contacts the other of the control strip and the base, thereby limiting further depression of the control strip.

[0305] Clause 23: The device of clause 22, wherein: the extension extends from a central segment of the control strip toward the base; the base has a recess; and when the control strip is in the unstressed position, the extension is spaced apart from the base, and when the control strip is in the loaded position, the extension protrudes into the recess.

[0306] Clause 24: The apparatus of clause 11, wherein the control strip is embedded within the footwear upper.

[0307] Clause 25: The apparatus of clause 11, wherein the base has a forwardly extending projection adjacent a medial side of the upper that underlies the foot-receiving void and a rearwardly extending projection along a lateral side of the upper that underlies the foot-receiving void.

[0308] Clause 26: The device of clause 1, wherein the base is coupled to a forward-most portion of the first and second side arms.

[0309] Clause 27: The device of clause 1, wherein the base extends rearwardly from the control strip.

[0310] Clause 28: The device of clause 1, wherein the base extends forwardly from the control strip.

[0311] Clause 29: The apparatus of clause 1, wherein the base is a sole structure of an article of footwear.

[0312] Clause 30: The apparatus of clause 1, wherein the base is a flexible footwear upper.

[0313] Clause 31: The device of any one of clauses 1 to 30, wherein the device is a single, unitary, one-piece component.

[0314] Item 32: A device for facilitating entry of a foot into an article of footwear and configured to surround a portion of a foot-receiving cavity in a heel region of the article of footwear, the device comprising: a control strip and a base positioned below the control strip; wherein the control strip comprises a series of slats, each slat having: a central segment; a medial arm extending from the central segment to a medial end connected to the medial side of the base; and a lateral arm extending from the central segment to a lateral end connected to the lateral side of the base; and wherein the control strip is biased to an unloaded position and elastically bends to a loaded position under the action of an applied force, at least one central segment being closer to the base in the loaded position than in the unloaded position, thereby storing potential energy that causes the control strip to return to the unloaded position when the applied load is removed.

[0315] Clause 33: The device of clause 32, wherein the control strip and the base are configured as fully elliptical leaf springs.

[0316] Clause 34: A device according to any one of clauses 32 and 33, wherein: the control strip defines a slot extending between the slats; when the control strip is in the unloaded position, the slats are spaced apart from each other by the slot; and one or more of the slots are closed between the slats so that one or more adjacent central segments contact each other in the loaded position.

[0317] Clause 35: The device of clause 34, wherein: the slots are parallel to one another; and the outer sides of the slats are flush with one another in the unloaded position.

[0318] Clause 36: An apparatus according to any one of clauses 32 to 35, wherein the lowest slat closest to the base at the central segment is shorter from the inner end to the outer end than the highest slat farthest from the central segment; and wherein the lowest slat is thinner than the highest slat.

[0319] Clause 37: The device of any of clauses 32 to 36, wherein a lowermost one of the slats has a tab extending from a lower edge of the central segment.

[0320] Clause 38: The device of any of clauses 32 to 37, wherein the outer surface of the base has a peripheral recess extending from a lower edge of the base.

[0321] Clause 39: The device of any of Clauses 32 to 38, further comprising: a resilient insert at least partially filling the groove.

[0322] Clause 40: The device of Clause 39, wherein the resilient insert comprises: a bushing extending along an inside of the slat; and spaced apart protrusions extending from the bushing into the slot.

[0323] Clause 41: The device of Clause 39, wherein the elastic insert is configured as a pleat that extends outwardly between the slats from the inside of the slats.

[0324] Clause 42: The device of any of Clauses 39 to 41, wherein the resilient insert comprises at least one of rubber or thermoplastic polyurethane.

[0325] Item 43: A device for facilitating entry of a foot into an article of footwear and configured to surround a portion of a foot-receiving cavity in a heel region of the article of footwear, the device comprising: an elastic corrugation comprising a central segment, a medial arm extending forward from the central segment, and a lateral arm extending forward from the central segment; wherein the corrugation comprises alternating ridges and grooves extending lengthwise along the medial arm, the central segment, and the lateral arm; and wherein the corrugation is biased to an unloaded position and is compressed to a loaded position under the action of an applied force, one or more adjacent ridges of the alternating ridges being closer to each other in the loaded position than in the unloaded position, thereby storing elastic energy that causes the corrugation to return to the unloaded position when the applied load is removed.

[0326] Clause 44: The device of clause 43, wherein: the corrugated body comprises pleats; and the ridges are convex pleats of the pleats, and the grooves are concave folds of the pleats.

[0327] Clause 45: The device of clause 44, wherein a first set of ridges and grooves extends from the medial arm to the lateral arm, and a second set of ridges and grooves extends only along the central segment.

[0328] Clause 46: The device of any one of Clauses 43 to 45, further comprising an upper flange extending along an upper edge of the corrugated body at the central segment.

[0329] Clause 47: The device of any of Clauses 43 to 46, further comprising a lower flange extending along a lower edge of the corrugation at the inner arm, the central segment, and the outer arm.

[0330] Clause 48: The device of any of Clauses 43 to 47, wherein the corrugated body is at least one of rubber or thermoplastic polyurethane.

[0331] Clause 49: An article of footwear comprising: an upper defining at least a portion of an ankle opening; a sole structure secured to and positioned beneath the upper; and a heel spring device comprising: a central segment secured to the upper behind the ankle opening; a medial arm extending downwardly and forwardly from the central segment; a lateral arm extending downwardly and forwardly from the central segment; and a base connected to both the medial arm and the lateral arm; wherein the base is secured to the shoe and wherein the central segment is biased to an unloaded position, the heel spring means elastically deforms to a loaded position under the action of an applied force, the central segment being closer to the base in the loaded position than in the unloaded position, and the heel spring means stores elastic energy that returns the central segment to the unloaded position when the applied load is removed, the upper moving with the central segment such that the ankle opening is closer to the sole structure when the central segment is in the loaded position than when the central segment is in the unloaded position.

[0332] Clause 50: The article of footwear according to clause 49, wherein: the sole structure includes a midsole; and the base is partially recessed into the midsole.

[0333] Clause 51: The article of footwear according to any of clauses 49 to 50, wherein the medial arm is secured to a medial side of the upper and the lateral arm is secured to a lateral side of the upper.

[0334] Clause 52. The article of footwear of clause 51, wherein when the central segment is in the loaded position, the medial arm and the lateral arm flex laterally outward and away from each other, thereby widening the ankle opening.

[0335] Clause 53: An article of footwear according to any one of clauses 49 to 52, wherein in the unloaded position the central segment is spaced apart from the base, and the device is characterized in that there is no rigid heel stabilizer located between the central segment and the base at the rear of the junction of the medial arm and the base and at the rear of the junction between the lateral arm and the base.

[0336] Clause 54: The article of footwear according to any one of clauses 49 to 53, wherein the medial arm and the lateral arm each twist outwardly along their respective longitudinal axes from the base to the central segment.

[0337] Clause 55: An article of footwear according to any one of clauses 49 to 54, wherein: one of the central segment and the base has an extension that extends at least partially toward the other of the central segment and the base; and when the central segment is in the unloaded position, the extension is spaced apart from the other of the central segment and the base.

[0338] Item 56: An article of footwear according to Item 55, wherein: the extension extends at least partially from the central segment toward the base; the base has a recess; and when the central segment is in the unloaded position, the extension is spaced apart from the base, and when the central segment is in the loaded position, the extension protrudes into the recess.

[0339] Item 57: The article of footwear of Item 55, wherein the extension extends from the central segment at least partially toward the base; and further comprising: a strap having a proximal end secured to the upper and a chamber at a distal end; and the extension being disposed in the chamber, wherein the strap covers the central segment.

[0340] Clause 58: The article of footwear according to any of clauses 49 to 57, wherein: the outer surface of the base has a peripheral recess extending from a lower edge of the base; and the sole structure has a flange seated in the peripheral recess.

[0341] Clause 59: The article of footwear according to any of clauses 49 to 58, wherein the central segment has a ramped surface that slopes toward an inner periphery of the central segment between the medial arm and the lateral arm.

[0342] Clause 60: The article of footwear according to any one of clauses 49 to 59, wherein the heel spring device is a single, unitary, one-piece component.

[0343] Clause 61: The article of footwear according to Clause 49, wherein the heel spring device comprises a bladder element including one or more fluid-filled interior chambers.

[0344] Clause 62: An article of footwear according to clause 61, wherein: the one or more fluid-filled internal chambers include: a chamber extending along the central segment; and one or more reservoirs, the one or more reservoirs being disposed at one or both of the medial arm and the lateral arm and being in fluid communication with the chamber extending along the central segment; and when the heel spring device is elastically deformed under the action of the applied force, the one or more reservoirs expand as fluid is diverted from the chamber extending along the central segment.

[0345] Clause 63: A footwear upper comprising: a flexible covering defining at least a portion of an ankle opening; a heel spring device comprising: a control strip having: a central segment secured to the flexible covering behind the ankle opening; a medial arm extending from the central segment and secured to a medial side of the flexible covering; and a lateral arm extending from the central segment and secured to a lateral side of the flexible covering; and a continuous base supporting the control strip and connected to both the medial arm and the lateral arm; and wherein the control strip is biased to an unstressed position in which the central segment is a first distance from the base, the control strip elastically deforms under an applied force to a loaded position in which the central segment is a second distance from the base that is less than the first distance, and the heel spring device stores potential energy that causes the control strip to return to the unstressed position when the applied load is removed.

[0346] Clause 64: The footwear upper of clause 63, wherein the flexible covering is an elastic, stretchable fabric, and further comprising a collar secured to the flexible covering and defining a front portion of the ankle opening; wherein the collar is stiffer than the elastic, stretchable fabric.

[0347] Clause 65: The footwear upper of any of clauses 63-64, further comprising: a heel tab secured to the flexible covering; wherein the central segment of the control strip has an aperture, and wherein the heel tab extends through the aperture.

[0348] Clause 66: The footwear upper of any of clauses 63 to 65, wherein when the central segment is in the loaded position, the medial and lateral arms flex laterally outwardly and away from each other to widen an ankle opening of the flexible covering.

[0349] Clause 67: Footwear upper according to any of clauses 63 to 66, characterized in that, at the rear of the junction between the control strip and the base, there is no rigid heel stabilizer located between the control strip and the base.

[0350] Clause 68: A footwear upper according to any of clauses 63 to 67, wherein the medial arm and the lateral arm each twist outwardly along their respective longitudinal axes from the base to a central section of the control strip.

[0351] Clause 69: A footwear upper according to any one of clauses 63 to 68, wherein: one of the control strip and the base has an extension extending toward the other of the control strip and the base; and when the control strip is in the unstressed position, the extension is spaced apart from the other of the control strip and the base, and when the control strip is in the loaded position, the extension contacts the other of the control strip and the base, thereby limiting further downward pressure on the control strip.

[0352] Clause 70: A footwear upper according to clause 69, wherein: the central segment of the control strip has an extension extending toward the base; the base has a recess; and when the control strip is in the unstressed position, the extension is spaced apart from the base, and when the control strip is in the loaded position, the extension protrudes into the recess.

[0353] Clause 71: A footwear upper according to any of clauses 63 to 70, wherein the central segment of the control strip has a ramped surface that slopes towards an inner periphery of the central segment between the medial arm and the lateral arm.

[0354] Clause 72: A footwear upper according to any of clauses 63 to 71, wherein the heel spring device is a single, unitary, one-piece component.

[0355] Clause 73: The footwear upper of Clause 63, wherein the heel spring device comprises a bladder element including one or more fluid-filled interior chambers.

[0356] Clause 74: A footwear upper as described in clause 73, wherein: the one or more fluid-filled internal chambers include: a chamber extending along the central segment; and one or more reservoirs, the one or more reservoirs being disposed at one or both of the medial arm and the lateral arm and being in fluid communication with the chamber extending along the central segment; and when the heel spring device is elastically deformed under the applied force, the one or more reservoirs expand as fluid is diverted from the chamber extending along the central segment.

[0357] Clause 75: An article of footwear comprising: a footwear upper including a flexible covering defining at least a portion of an ankle opening; a sole structure secured to and positioned beneath the footwear upper; a heel spring device comprising: a control strip having: a central segment secured to the flexible covering behind the ankle opening; a medial arm extending downwardly and forwardly from the central segment along a medial side of the footwear upper; and a lateral arm extending downwardly and forwardly from the central segment along a lateral side of the footwear upper; and a spring operably connected to the control strip and biasing the control strip to an unstressed position; and wherein the control strip pivots rearwardly to a loaded position under the action of an applied force, thereby storing potential energy in the spring, the potential energy causing the control strip to return to the unstressed position when the applied load is removed, the flexible covering moving with the control strip.

[0358] Article 76: The article of footwear of Article 75, further comprising: a pin connected to both the medial arm and the lateral arm and extending through the sole structure; and wherein the spring is wound around the pin and has an end fixed to pivot with the control strip and another end fixed relative to the control strip.

[0359] Article 77: An article of footwear comprising: a footwear upper including a flexible covering defining at least a portion of an ankle opening; a sole structure secured to and positioned beneath the footwear upper; a heel spring device comprising: a rear control strip having: a central segment secured to the flexible covering behind the ankle opening; a medial arm extending downwardly and forwardly from the central segment along a medial side of the footwear upper; and a lateral arm extending downwardly and forwardly from the central segment along a lateral side of the footwear upper; a front strip having : a central segment secured to the flexible covering in front of the ankle opening; a medial arm extending downwardly and rearwardly from the central segment along the medial side of the upper; and a lateral arm extending downwardly and rearwardly from the central segment along the lateral side of the upper; wherein the front bar and the rear control bar intersect and are secured to each other at the lateral side of the footwear upper and at the medial side of the footwear upper; and wherein the rear control bar pivots rearwardly to a loaded position under the action of an applied force, thereby storing potential energy that returns the rear control bar to an unstressed position when the applied load is removed, and the flexible covering moves with the rear control bar.

[0360] "A," "an," "said," "at least one," and "one or more" are used interchangeably to indicate that there is at least one item. Unless the context clearly indicates otherwise, there may be multiple such items. Unless the context clearly and clearly indicates otherwise, all numerical values ​​of parameters (e.g., amounts or conditions) in this specification (including the appended claims) should be understood to be modified by the term "about" in all cases, regardless of whether "about" actually appears before the numerical value. "About" means that the numerical value described allows some minor imprecision (something close to the accuracy of the value; approximately or moderately close to the value; almost). If the imprecision provided by "about" is not otherwise understood in this ordinary sense in the art, then "about" as used herein at least indicates the variation that may be caused by the ordinary methods of measuring and using such parameters. In addition, the disclosed range should be understood to specifically disclose all values ​​within the range and the range further divided. All references cited herein are incorporated herein in their entirety.

[0361] The terms "comprising," "including," and "having" are inclusive and, therefore, specify the presence of the stated features, steps, operations, elements, or parts, but do not preclude the presence or addition of one or more other features, steps, operations, elements, or parts. The order of steps, processes, and operations may be changed when possible, and additional or optional steps may be employed. As used in this specification, the term "or" includes any one and all combinations of the associated listed items. The term "any" is understood to include any possible combination of the referenced items, including "any one" of the referenced items. The term "either" is understood to include any possible combination of the referenced claims in the appended claims, including "any one" of the referenced claims.

[0362] One of ordinary skill in the art will recognize that terms such as "above," "below," "upward," "downward," "top," "bottom," etc. may be used descriptively with respect to the accompanying drawings and are not meant to limit the scope of the invention as defined by the claims.

[0363] Although several modes for implementing many aspects of the present teachings have been described in detail, those skilled in the art to which these teachings relate will recognize various alternative aspects for implementing the present teachings within the scope of the appended claims. It is to be understood that all matter contained in the above description or shown in the accompanying drawings is to be interpreted as illustrative only and not limiting.

Claims

1. An article of footwear comprising: a footwear upper defining at least a portion of a foot-receiving cavity and an ankle opening; a sole structure positioned beneath and secured to the footwear upper; a heel spring device configured to surround a portion of the foot-receiving cavity at a heel region of the article of footwear and comprising a control strip having: a central segment secured to the footwear upper rearward of the ankle opening; and a medial sidearm extending downwardly and forwardly from the central segment along a medial side of the footwear upper; and a lateral sidearm spaced from the medial sidearm and extending downwardly and forwardly from the central segment along a lateral side of the footwear upper; and fastening systems, including fastening cables; wherein the heel spring device has a ring fixed to the medial side arm and the lateral side arm, the ring serving as an anchor for the fastening cable; wherein the heel spring device comprises a base supporting the control strip and connected to the control strip at a resiliently bendable joint; wherein the base passes through the sole structure, or the base arms of the base terminate at the sole structure and are sufficiently secured to the sole structure such that the sole structure serves as a base.

2. The article of footwear according to claim 1, wherein: The fastening cables extend over the footwear upper.

3. The article of footwear according to claim 1 , wherein: The base is continuous and extends between and is connected to the medial and lateral side arms.

4. The article of footwear according to claim 3, wherein: The base has a central section, a first base arm and a second base arm, all disposed in a common plane, each extending from the central section of the base.

5. The article of footwear according to any one of claims 1 to 4, wherein The sole structure is a midsole.

6. The article of footwear according to any one of claims 1 to 4, wherein The material of the control strip has rigidity so that the control strip remains in an unstressed position when no external load is applied thereto, and returns to the unstressed position after elastic bending due to the elasticity of the material of the control strip.

7. The article of footwear according to any one of claims 1 to 4, wherein: The heel spring assembly is a single, unitary, one-piece component.

8. An article of footwear comprising: a footwear upper defining at least a portion of a foot-receiving cavity and an ankle opening, the footwear upper having a flexible covering with an elastically stretchable material in a heel region; a sole structure positioned beneath and secured to the footwear upper; A heel spring device configured to surround a portion of a foot-receiving cavity at a heel region of the article of footwear, comprising a control strip having: a central segment, posterior to the ankle opening; and a medial sidearm extending downwardly and forwardly from the central segment along a medial side of the footwear upper; and a lateral sidearm spaced from the medial sidearm and extending downwardly and forwardly from the central segment along a lateral side of the footwear upper; wherein the heel spring device is secured to the sole layer of the sole structure and the footwear upper; wherein a central section of the control strip has a thinned portion, and wherein the flexible covering of the footwear upper is sewn to the heel spring device at the thinned portion; The material of the control strip has rigidity, so that the control strip remains in a stress-free position when no external load is applied thereto, and returns to the stress-free position after elastic bending due to the elasticity of the material of the control strip.

9. The article of footwear according to claim 8, wherein: The heel spring device includes a lateral thin extension extending from the lateral side arm and a medial thin extension extending from the medial side arm, the lateral thin extension and the medial thin extension being sufficiently thin to allow the footwear upper to be sewn to the heel spring device through the lateral thin extension and the medial thin extension.

10. The article of footwear according to claim 9, wherein: The outer thin extension portion and the inner thin extension portion are spaced apart.

11. The article of footwear according to any one of claims 8 to 10, wherein: The heel spring arrangement further includes a base supporting the control strip and connected to the control strip at a resiliently flexible joint.

12. The article of footwear according to claim 11, wherein The base extends around a rearwardly rearward portion of the footwear upper from a lateral side of the footwear upper to a medial side of the footwear upper.

13. The article of footwear according to any one of claims 8 to 10, wherein: The footwear upper includes a foam collar defining a forward portion of the ankle opening, the foam collar being secured to the flexible covering.

14. The article of footwear according to claim 13, wherein: The foam collar is stiffer than the elastic stretchable material.

15. The article of footwear according to claim 13, wherein: The foam collar includes a foam pad located at a rear portion of the foam collar, the foam pad protruding inwardly into the ankle opening.

16. The article of footwear according to any one of claims 8 to 10, wherein: The heel spring assembly is a single, unitary, one-piece component.

17. A heel spring device for facilitating entry of a foot into a foot-receiving cavity of an article of footwear, the heel spring device being configured to surround a portion of the foot-receiving cavity at a heel region of the article of footwear and comprising: a control strip having a central segment, a first side arm extending from the central segment, and a second side arm spaced from the first side arm and extending from the central segment; and a continuous base supporting the control strip and connected to both the first side arm and the second side arm; wherein the control strip is biased to an unloaded position wherein the central segment is a first distance from the base, and wherein the control strip is elastically deformed under the action of an applied force to a loaded position wherein the central segment is a second distance from the base that is less than the first distance, the heel spring means storing potential energy that causes the control strip to return to the unstressed position when the applied load is removed; wherein the frontmost portion of the inner surface of the first side arm includes a medial recess, such that the first side arm is thinner at the medial recess than behind the medial recess, and the frontmost portion of the inner surface of the second side arm includes a lateral recess, such that the second side arm is thinner at the lateral recess than behind the lateral recess, and the upper of the footwear article is used to be fixed to the first side arm at the medial recess and to the second side arm at the lateral recess.

18. The heel spring assembly of claim 17, wherein: The first side arm and the second side arm are asymmetrical about a longitudinal axis extending through the base between the first side arm and the second side arm.

19. The heel spring assembly of claim 17, wherein: The central segment of the control strip has a ramp surface that slopes toward an inner periphery of the central segment between the first side arm and the second side arm.

20. The heel spring assembly of claim 17, wherein: The material of the control strip has rigidity so that the control strip remains in an unstressed position when no external load is applied thereto, and returns to the unstressed position after elastic bending due to the elasticity of the material of the control strip.

21. The heel spring device according to any one of claims 17 to 20, wherein: The heel spring assembly is a single, unitary, one-piece component.

22. An article of footwear comprising a heel spring device according to any one of claims 18 to 21.

23. The article of footwear according to claim 22, wherein: The heel spring device has an aperture in the central segment; and the footwear upper of the article of footwear includes a tab extending through the aperture.

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