Footwear heel spring device

Abstract

A device configured to surround a portion of a foot receiving cavity (1839) in the heel region (13) of a footwear article 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 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 a stress-free position where the central segment is a first distance (D1, D2) from the base, and elastically bends to a loaded position (10A, 910A, D2) under applied force, where the central segment is a second distance (D1, D2) from the base smaller 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 Chinese invention patent application filed on October 25, 2017, with application number 202011456320.X and invention title "Spring Device for Heel of Footwear".

[0002] Cross-references to related applications

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

[0004] This instruction generally covers heel spring devices for footwear. Background Technology

[0005] Traditionally, placing footwear on the foot usually requires using one or two hands to stretch the ankle opening of the footwear and to hold the rear portion in place during foot insertion, especially in cases where the upper is relatively soft and / or the upper does not have a heel counter made of flexible fabric that is fixed to the ankle opening and faces backward. Attached Figure Description

[0006] Figure 1 This is a perspective view of the heel spring mechanism of footwear in the unloaded position.

[0007] Figure 2 yes Figure 1 A schematic plan view of the device, in which the loading position of the device is shown in dashed lines.

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

[0009] Figure 4 It is along Figure 3 The line 4-4 in the middle is cut off Figure 3 The diagram shows a partial cross-sectional view of the device and the sole of the shoe, and also shows the flexible covering of the footwear upper that is fixed to the device.

[0010] Figure 5 It includes Figure 4 A schematic diagram of a partial side view of the outer side of a footwear item, including the device, the upper of the shoe, and the sole.

[0011] Figure 6 yes Figure 5A schematic diagram of a partial side view of the inner side of a footwear item.

[0012] Figure 7 This is a schematic diagram of a partial side view of the inner side of an optional embodiment of a footwear article including an optional heel spring device.

[0013] Figure 8 yes Figure 7 A schematic diagram of a partial side view of the outer side of footwear.

[0014] Figure 9 This is a schematic perspective view of an optional embodiment of a footwear article including an optional heel spring device.

[0015] Figure 10 This is a schematic diagram of the inner side view of an optional embodiment of a footwear article including an optional heel spring device.

[0016] Figure 11 This is a schematic diagram of a partial side view of an optional embodiment of a footwear article including an optional heel spring device.

[0017] Figure 12 yes Figure 11 A schematic diagram of the rear view of footwear.

[0018] Figure 13 yes Figure 11 A schematic diagram of a partial plan view of footwear.

[0019] Figure 14 yes Figure 13 along Figure 13 A schematic diagram of a partial cross-section of a footwear item, taken by line 14-14.

[0020] Figure 15 This is a schematic diagram of a partial side view of an optional embodiment of a footwear article including an optional heel spring device.

[0021] Figure 16 This is a schematic diagram of a partial side view of an optional embodiment of a footwear article including an optional heel spring device.

[0022] Figure 17 This is a schematic diagram of a partial side perspective view of an optional embodiment of a footwear article including an optional heel spring device.

[0023] Figure 18 yes Figure 17 A schematic diagram of the rear perspective view of footwear.

[0024] Figure 19 This is a schematic partial perspective view of an optional embodiment of a footwear article including an optional heel spring device.

[0025] Figure 20 This is a schematic perspective view of an optional embodiment of a footwear article including an optional heel spring device.

[0026] Figure 21 yes Figure 20 A schematic perspective view of the heel spring device.

[0027] Figure 22 yes Figure 21 A schematic diagram of another perspective view of the heel spring device, with the loading position shown in dashed lines.

[0028] Figure 23 A representative graph of force in Newtons versus displacement in millimeters is shown within the scope of this teaching, during the loading and unloading of the heel spring device.

[0029] Figure 24 This is a schematic perspective view of an optional embodiment of a footwear article including an optional heel spring device.

[0030] Figure 25 yes Figure 24 A schematic perspective view of the heel spring device.

[0031] Figure 26 This is a schematic perspective view of an optional embodiment of a footwear article including an optional heel spring device.

[0032] Figure 27 yes Figure 26 A schematic perspective view of the heel spring device.

[0033] Figure 28 This is a schematic diagram of the inner side view of an alternative embodiment of a heel spring device for footwear.

[0034] Figure 29 yes Figure 28 A schematic diagram of the rear view of the heel spring device.

[0035] Figure 30 This is a schematic perspective view of an alternative embodiment of a heel spring device for footwear.

[0036] Figure 31 yes Figure 30 A schematic diagram of the side view of the outer side of the heel spring device.

[0037] Figure 32 This is a schematic diagram of a partial side perspective view of an optional embodiment of a footwear article including an optional heel spring device.

[0038] Figure 33This is a schematic partial perspective view of an optional embodiment of a footwear article including an optional heel spring device.

[0039] Figure 34 This is a schematic perspective view of an alternative embodiment of a heel spring device for footwear.

[0040] Figure 35 yes Figure 34 A schematic diagram of the rear view of the spring device fixed to the heel of the shoe upper.

[0041] Figure 36 This is a schematic perspective view of an alternative embodiment of a heel spring device for footwear.

[0042] Figure 37 It has an unloaded location. Figure 36 A perspective view of footwear with a heel spring mechanism.

[0043] Figure 38 It has a heel spring device in the loaded position. Figure 37 A perspective view of footwear.

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

[0045] Figure 40 It has a heel spring device in the loaded position. Figure 39 A perspective view of footwear.

[0046] Figure 41 This is a schematic perspective view of an alternative embodiment of a heel spring device for footwear.

[0047] Figure 42 It has an unloaded location. Figure 41 A perspective view of footwear with a heel spring mechanism.

[0048] Figure 43 It has a heel spring device in the loaded position. Figure 42 A perspective view of footwear.

[0049] Figure 44 This is a schematic perspective view of an alternative embodiment of a heel spring device for footwear.

[0050] Figure 45 It has an unloaded location. Figure 44 A schematic diagram of a partial perspective view of a footwear item with a heel spring device.

[0051] Figure 46It has a heel spring device in the loaded position. Figure 45 A schematic diagram of a partial perspective view of footwear.

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

[0053] Figure 48 It has Figure 47 A schematic diagram of a partial perspective view of a footwear item with the heel spring device in the unloaded position.

[0054] Figure 49 This is a schematic perspective view of a footwear article having an alternative embodiment of a heel spring device in the unloaded position, with the loaded position shown in dashed lines.

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

[0056] Figure 51 It has a heel spring device in the loaded position. Figure 50 A schematic diagram of a partial side view of footwear.

[0057] Figure 52 This is a schematic perspective view of an alternative embodiment of the heel spring device in the unloaded position, and partial upper and sole structures are shown in dashed lines.

[0058] Figure 53 This is a schematic side view of a footwear article having an alternative embodiment of a heel spring device in the unloaded position, with the loaded position shown in dashed lines.

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

[0060] Figure 55 yes Figure 54 A schematic side perspective view of the outer side of the heel spring device in the unloaded position.

[0061] Figure 56 yes Figure 54 A schematic diagram of the outer perspective view of the heel spring device in the loading position.

[0062] Figure 57 yes Figure 54 A schematic diagram of the front view of the heel spring device.

[0063] Figure 58 yes Figure 57 along Figure 57A schematic cross-sectional view of the heel spring device taken by line 58-58.

[0064] Figure 59 It includes the straps that are attached to the shoe upper. Figure 54 A schematic diagram of a partial side view of a part of a footwear item.

[0065] Figure 60 yes Figure 59 A schematic diagram of a partial view of a portion of the strip.

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

[0067] Figure 62A yes Figure 61 A schematic diagram of the perspective side view of the heel spring device in the unloaded position.

[0068] Figure 62B yes Figure 62A A schematic diagram of a perspective side view of the heel spring device in the loading position.

[0069] Figure 63 yes Figure 61 A schematic diagram of the rear perspective view of the heel spring device in the unloaded position with the compressible insert removed.

[0070] Figure 64 yes Figure 61 A schematic diagram of the inside perspective view of the compressible insert of the heel spring device in the unloaded position.

[0071] Figure 65 It is along Figure 66 The line 65-65 intercepted in the middle Figure 66 A schematic cross-sectional view of the heel spring device.

[0072] Figure 66 yes Figure 61 A schematic diagram of the front view of the heel spring device.

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

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

[0075] Figure 69 yes Figure 68 A schematic perspective view of the heel spring device in the unloaded position, wherein the heel spring device is shown.

[0076] Figure 70 yes Figure 69 A schematic diagram of the front view of the heel spring device.

[0077] Figure 71A yes Figure 70 along Figure 70 A schematic cross-sectional view of the heel spring device taken from line 71A-71A.

[0078] Figure 71B It is in the loading position. Figure 71A A schematic cross-sectional view of the heel spring device.

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

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

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

[0082] Figure 75 yes Figure 74 A schematic diagram of the perspective side view of the heel spring device in the unloaded position.

[0083] Figure 76 yes Figure 75 along Figure 75 A schematic cross-sectional view of the heel spring device taken by line 76-76.

[0084] Figure 77 yes Figure 74 A schematic diagram of the side view of the heel spring device in the unloaded position.

[0085] Figure 78 It is in the loading position. Figure 74 A schematic diagram of the side view of the heel spring device.

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

[0087] Figure 80 It has Figure 79 A schematic diagram of the outer side of a footwear item with a heel spring device.

[0088] Figure 81 yes Figure 80 A diagram of the inside of footwear.

[0089] Figure 82 yes Figure 80 A schematic diagram of the rear view of footwear.

[0090] Figure 83 yes Figure 80 A plan view of the lining of the sole of a footwear item.

[0091] Figure 84 yes Figure 83 A plan view of the shoe sole interlayer, in which Figure 79 The heel spring device is seated in the recess of the sole interlayer.

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

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

[0094] Figure 87 It has Figure 85 A schematic diagram of a footwear item with a heel spring mechanism, with the upper shown in dashed lines.

[0095] Figure 88 yes Figure 85 A schematic partial plan view of the arm of the heel spring device that connects to the upper of a footwear shoe.

[0096] Figure 89 yes Figure 87 A schematic plan view of the sole interlayer of footwear.

[0097] Figure 90 yes Figure 85 The seat Figure 89 A schematic plan view of the heel spring device in the recess of the shoe sole interlayer.

[0098] Figure 91 yes Figure 85 An exploded partial view of the heel spring mechanism, showing a tab on the upper extending through a hole in the heel spring mechanism and a pin.

[0099] Figure 92 yes Figure 85 A partial view of the heel spring device, wherein the heel spring device has a tab fixed in a ring, and wherein a pin is inserted in the ring.

[0100] Figure 93 This is a schematic plan view of an alternative embodiment of the heel spring device.

[0101] Figure 94 It includes Figure 93 A schematic diagram of the rear view of a footwear item with a heel spring device. Detailed Implementation

[0102] This article discloses a heel spring device for facilitating foot entry into footwear. Each heel spring device enables hands-free foot entry, such as by using the foot to load the heel spring device to enter the foot receiving cavity from a rear position, and by allowing the foot to slide forward and downward into the foot receiving cavity.

[0103] Within the scope of this disclosure, a device for facilitating foot entry into a foot receiving cavity of a footwear article is configured to surround a portion of the foot receiving cavity in the heel region of the footwear article, 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 and extending from the central segment. A continuous base can support the control strip and can be connected to both the first and second side arms. The control strip is biased to an unloaded position where the central segment is a first distance from the base, and the control strip elastically deforms under an applied force to a loaded position where the central segment is a second distance from the base smaller than the first distance. The device stores potential energy that causes the control strip to return to a stress-free 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 joint may be referred to herein as a hinged joint or a hinged junction.

[0105] The device including the control bar and the base can be a single, integral, or monolithic component. For example, in one or more embodiments, the control bar has an arcuate shape, and the base has an arcuate shape. Thus, the control bar and the base are constructed as a full elliptical leaf spring.

[0106] In one or more embodiments of the device, the base has a central segment, a first base arm, and a second base arm, all disposed within a common plane. The first base arm and the second base arm are spaced apart and both extend from the central segment of the base. The first base arm and a 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 the unloaded position, the first and second side arms extend at an acute angle relative to the common plane of the base. When the control bar is pressed down, the first and second side arms 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 bar is in the loading position, the first and second side arms are bent apart from each other. When the footwear upper is attached to the side arms, the foot receiving cavity of the footwear upper opens wider when the side arms are bent apart, thereby further facilitating foot entry into the foot receiving cavity.

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

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

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

[0111] In one or more embodiments of the device, the first and second side arms are each twisted outward along their respective longitudinal axes from the base to the central segment of the control bar. This outward twisting facilitates downward and backward movement of the central segment 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 and second side arms. For example, the first side arm may be the medial side arm, and the second side arm may be the lateral side arm. Similar to the shape of a typical heel area of ​​a foot, the medial side arm may be shorter than the lateral side arm and may have a greater lateral curvature than the lateral side arm.

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

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

[0115] In one or more embodiments of the device, the base may be located below the control bar, wherein a first side arm is located on the inner side of the upper defining at least a portion of the ankle opening, a second side arm is located on the outer side of the upper, and the central segment of the control bar is located behind the ankle opening of the upper.

[0116] In one or more embodiments of the device, the foremost 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 it, and the foremost 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 it. 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 extends outward from the control bar. The lever can help to press down on the control bar.

[0119] In one or more embodiments, the heel device includes a bladder element comprising one or more fluid-filled internal cavities. The one or more fluid-filled internal cavities may include cavities extending along a central segment. The cavities extending along the central segment may also extend along one or both of a first or 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 disposed on one or both of the first and second side arms and in fluid communication with the cavities extending along the central segment. When the heel spring device resiliently deforms under applied force, the one or more reservoirs expand as fluid transfers from the cavities extending along the central segment.

[0120] The base of the device can be fixed to a flexible footwear upper that defines at least a portion of the ankle opening, such that the base is positioned below a control strip, with a first side arm located on the medial side of the footwear upper, a second side arm located on the lateral side of the footwear upper, and the central segment of the control strip located behind the ankle opening. The base can extend from the lateral side to the medial side around the rearmost portion of the footwear upper. The control strip can be embedded within the footwear upper.

[0121] The flexible footwear upper defines a foot receiving space (also known as a foot receiving cavity), and a base can be located below the foot receiving space. The base can be attached to the foremost portions of the first and second side arms. The base can extend rearward from the control strip, extend forward from the control strip, or extend both rearward and forward from the control strip.

[0122] In one or more embodiments, the base has a forward-extending protrusion on the inner side of the footwear upper adjacent to the foot receiving space, and a rearward-extending protrusion on the outer side of the footwear upper adjacent to the foot receiving space.

[0123] In one or more embodiments, the sole structure is attached to the footwear upper and located below the foot receiving space. 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 located within the recess.

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

[0125] In one or more embodiments of the device, the control strip is embedded within the footwear upper. For example, the device may be covered by layers of flexible overlays on the footwear upper and sandwiched between these layers.

[0126] In one or more embodiments of the device, the base is the 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 flex 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 through them. In one or more embodiments, the at least one slot extending through the first side arm may extend along the length of the first side arm, and the at least one slot extending through the second side arm may extend along the length of the second side arm. In an alternative embodiment, the at least one slot extending through the first side arm extends transversely to the length of the first side arm, and the at least one slot extending through the second side arm extends transversely to the length of the second side arm.

[0128] Within the scope of this disclosure, a heel spring device for facilitating foot entry into footwear is configured to surround a portion of a foot receiving cavity in the heel region of the footwear and includes a control bar and a base located below the control bar. In one or more embodiments, the control bar comprises a series of slats. Each slat has a central segment, an inner arm extending from the central segment to an inner end connected to an inner surface of the base, and an outer arm extending from the central segment to an outer end connected to an outer surface of the base. The control bar is biased to an unloaded position and elastically bends to a loaded position under an applied force, 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 bar to return to the unloaded position when the applied load is removed. For example, the control bar and the base may be configured as a fully elliptical leaf spring.

[0129] The device stores potential energy, such as elastic energy and / or spring energy, which causes the control bar to return to a stress-free position when the applied load is removed. As used herein, elastic bending can also be referred to as resilient bending and causes resilient deformation or elastic deformation. For example, the foot can press down on the control bar and slide into the foot receiving cavity of the attached footwear upper without the need for hand or any tool to adjust the upper to allow the foot to enter.

[0130] In one or more embodiments of the device, a control bar defines slots extending between the slats. When the control bar is in the unloaded position, the slats are spaced apart by the slots. The slots can close 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 lowest slat closest to the base at the central segment is shorter from its inner end to its outer end than the highest slat furthest from the central segment from its inner end to its outer end. In one or more embodiments, the lowest slat is thinner than the highest slat. In one or more embodiments of the device, the lowest slat has a tab extending from the lower edge of the central segment. The outer surface of the base may have a peripheral recess extending from the lower edge of the base. For example, the peripheral recess may receive a flange of a shoe sole structure.

[0132] In one or more embodiments of the device, the resilient insert at least partially fills the groove. The resilient insert may include at least one of a resilient compressible material, such as rubber or thermoplastic polyurethane, and may be, but is not limited to, foam. The resilient insert may include a sleeve extending along the inner side of the slats, and spaced-apart protrusions extending from the sleeve into the groove. In one or more embodiments of the device, the resilient insert is configured as a pleat extending outward from the inner side of the slats between the slats.

[0133] Within the scope of this disclosure, a heel spring device for facilitating foot entry into footwear is configured to surround a portion of a foot receiving cavity in the heel region of the 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 longitudinally along the medial arm, central segment, and lateral arm. The corrugated body is biased to an unloaded position and compressed to a loaded position under an applied force, wherein adjacent ridges of the alternating ridges are closer to each other 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, a corrugated body may include bellows. Ridges may be pleats of the bellows, and grooves may be folds of the bellows. The corrugated body may be an elastically deformable material, such as at least one of rubber or thermoplastic polyurethane, and may be an elastic foam (e.g., polymeric foam materials, 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 inner arm to the outer 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 the upper edge of the corrugated body at the central segment, and may also include a lower flange extending along the lower edge of the corrugated body at the medial arm, central segment, and lateral arm.

[0137] Within the scope of this teaching, footwear articles include an upper defining at least a portion of an ankle opening, a sole structure fixed to and located beneath 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 connecting both the medial and lateral arms. 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 applied force, in which the central segment is closer to the base than in the unloaded position. The heel spring device stores elastic energy that causes the central segment to return to the unloaded position when the applied load is removed, and the upper moves 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.

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

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

[0140] In one or more embodiments of the footwear, 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 joint between the inner arm and the base and at the rear of the joint between the outer arm and the base.

[0141] In one or more embodiments of footwear, the inner arm and outer arm are each twisted outward along their respective longitudinal axes from the base to the central segment.

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

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

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

[0145] In one or more embodiments of footwear, the heel spring device includes a bladder element comprising one or more fluid-filled internal cavities. The one or more fluid-filled internal cavities may include cavities extending along a central segment. The cavities extending along the central segment may also extend along one or both of an inner or outer arm, and may be tubular or other shapes. The one or more fluid-filled internal cavities may further include one or more reservoirs disposed at one or both of the inner and outer arms and in fluid communication with the cavities extending along the central segment. When the heel spring device rebounds under an applied force, one or more reservoirs expand as fluid is transferred from the cavities extending along the central segment.

[0146] In one or more embodiments of the footwear, the central segment has a sloping surface that slopes toward the inner periphery of the central segment between the inner and outer arms. In one or more embodiments, the heel spring assembly is a single, integral, monolithic component.

[0147] In one or more embodiments, the footwear upper includes a flexible cover defining at least a portion of an ankle opening. The footwear upper includes a heel spring device comprising a control bar having a central segment of the flexible cover fixed to the rear of the ankle opening, an inner arm extending from the central segment and fixed to an inner surface of the flexible cover, and an outer arm extending from the central segment and fixed to an outer surface of the flexible cover. The heel spring device may further include a continuous base supporting the control bar and connected to both the inner and outer arms. The control bar is biased to an unloaded position where the central segment is a first distance from the base; the control bar elastically deforms under applied force to a loaded position where the central segment is a second distance from the base smaller than the first distance; and the device stores potential energy that causes the control bar to return to the unloaded position when the applied load is removed.

[0148] In one or more embodiments of the footwear upper, the flexible cover is an elastically stretchable fabric, and the footwear upper also includes a collar that is attached to the flexible cover and defines a front portion of the ankle opening. The collar is stiffer than the elastically stretchable fabric.

[0149] In one or more embodiments, the footwear upper also includes a heel tab secured to a flexible overlay. A central segment of the control strip has a hole, and the heel tab extends through the hole.

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

[0151] In one or more embodiments, the footwear upper is characterized in that there is no rigid heel stabilizer located between the control strip and the base at the rear of the joint between the control strip and the base.

[0152] In one or more embodiments of the footwear upper, the inner arm and the outer arm are each twisted outward along their respective longitudinal axes from the base to the 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 extending toward the other of the control strip and the base. When the control strip is in the unloaded 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.

[0154] In one or more embodiments of the footwear upper, the central segment of the control strip has an extension extending toward a base having a recess. When the control strip is in a stress-free position, the extension is spaced apart from the base, and when the control strip is in a loaded position, the extension protrudes into the recess.

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

[0156] In one or more embodiments of the footwear upper, the central segment of the control strip has a sloping surface that slopes toward the inner periphery of the central segment between the inner and outer arms.

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

[0158] In one or more embodiments, the footwear article includes a footwear upper comprising a flexible cover defining at least a portion of an ankle opening. The footwear article also includes a sole structure and a heel spring device attached to and located beneath the footwear upper. The heel spring device may include a control bar having a central segment attached to the flexible cover posterior to the ankle opening, an inner arm extending downward and forward from the central segment, and an outer arm extending downward and forward from the central segment. The heel spring device may also include a continuous base supporting the control bar and connected to both the inner and outer arms. The base may be attached to the sole structure. The control bar is biased to an unloaded position where the central segment is a first distance from the base; under applied force, the control bar elastically bends to a loaded position where the central segment is a second distance from the base smaller than the first distance; and the device stores elastic energy that returns the control bar to the unloaded position when the applied load is removed. The flexible cover moves with the control bar.

[0159] In one or more embodiments of the footwear article, the sole structure includes a sole interlayer, and the base is partially recessed into the sole interlayer. In one or more embodiments of the footwear article, the medial arm is fixed to the medial side of the flexible overlay, and the lateral arm is fixed to the lateral side of the flexible overlay. In one or more embodiments of the footwear article, when the central segment is in the loaded position, the medial and lateral arms bend laterally outward and separately from each other, thereby widening the ankle opening of the flexible overlay. In one or more embodiments of the footwear article, the footwear article is characterized in that there is no rigid heel stabilizer located between the control strip and the base at the rear of the joint between the control strip and the base.

[0160] In one or more embodiments of the footwear article, the inner arm and outer arm are each twisted outward along their respective longitudinal axes from the base to the central segment of the control strip. In one or more embodiments of the footwear article, one of the control strip and the base has an extension extending toward the other of the control strip and the base. When the control strip is in the unloaded 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.

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

[0162] In one or more embodiments, the footwear article includes a footwear upper comprising a flexible cover defining at least a portion of an ankle opening, a sole structure fixed to and located beneath the footwear upper, and a heel spring device. The heel spring device may include a control bar having a central segment fixed to the flexible cover posterior to the ankle opening, an inner arm extending downward and forward along the inner side of the footwear upper from the central segment, and an outer arm extending downward and forward along the inner side of the footwear upper from the central segment. The heel spring device may also include a mechanical spring operatively connected to the control bar and biasing the control bar to an unloaded position. The control bar may pivot rearward to a loaded position under the action of an applied force, thereby storing potential energy in the spring, which causes the control bar to return to the unloaded position when the applied load is removed, with the flexible cover moving with the control bar.

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

[0164] In one or more embodiments, the footwear article includes a footwear upper and a sole structure. The footwear upper includes a flexible cover defining at least a portion of an ankle opening, and the sole structure is attached to and located beneath the footwear upper. The footwear article may also include a heel spring device. The heel spring device may include a rear control bar having a central segment attached to the flexible cover behind the ankle opening, an inner arm extending downward and forward along the inner side of the footwear upper from the central segment, and an outer arm extending downward and forward along the inner side of the footwear upper from the central segment. The heel spring device may also include a front bar having a central segment attached to the flexible cover in front of the ankle opening, an inner arm extending downward and backward along the inner side of the upper from the central segment, and an outer arm extending downward and backward along the inner side of the upper from the central segment. The front bar and the rear control bar may intersect and be attached to each other at the outer side and the inner side of the upper. The rear control bar pivots rearward to the loaded position under the applied force, thereby storing potential energy. This potential energy causes the front bar to return to the unloaded position when the applied load is removed, and the flexible cover moves with the rear control bar.

[0165] Within the scope of this teaching, a footwear article includes a footwear upper comprising a flexible cover defining at least a portion of an ankle opening, a sole structure fixed to and beneath the footwear upper, and a heel spring device. The heel spring device may include a control bar and a continuous base. The control bar may have a central segment fixed to the flexible cover behind the ankle opening, an inner arm extending from the central segment and fixed to the inner side of the flexible cover, and an outer arm extending from the central segment and fixed to the outer side of the flexible cover. The base may support the control bar and may be connected to both the inner and outer arms, and is fixed to the sole structure. The control bar is biased to an unloaded position where the central segment is a first distance from the base, and the control bar elastically bends to a loaded position under applied force where the central segment is a second distance from the base smaller than the first distance. The device stores potential energy, such as elastic energy and / or spring energy, which causes the control bar to return to the unloaded position when the applied load is removed, and the flexible cover moves with the control bar.

[0166] Referring to the accompanying drawings, similar reference numerals denote similar parts. Figure 1 It shows a design for easy foot entry Figure 5 and Figure 6The device 10 for the footwear article 12 shown herein. Shoes are described herein as leisure shoes and athletic shoes, but this teaching also includes footwear articles for dress shoes, work shoes, sandals, slippers, boots, or any other category of footwear.

[0167] like Figure 5 As shown, the device 10 is configured to surround a portion of the foot receiving cavity 47 at the heel region 13 of the footwear article 12. When a person's foot is supported on the sole structure 32 within the foot receiving cavity 47 and its size corresponds to that of the footwear article 12, the heel region 13 typically includes a portion of the footwear article 12 corresponding to the rear portion of the person's foot (including the ankle bone). The forefoot region 15 of the footwear article 12 (in...) Figure 10 , Figure 80 and Figure 87 The footwear articles 312, 3212, and 3312 (best shown herein) generally include the portion of the footwear article 12 corresponding to the toes and the joint connecting the metatarsals and phalanges of the human foot (which may be interchangeably referred to herein as a "metatarsopalatine joint" or "MPJ" joint). The midfoot area 17 of the footwear article 12 (in...) Figure 10 , Figure 80 and Figure 87 (As best shown in the text, footwear articles 312, 3212 and 3312 are disposed between the heel area 13 and the forefoot area 15, and generally include a portion of the footwear article 12 corresponding to the arch area of ​​the human foot, including the navicular joint.)

[0168] The device 10 includes a control bar 14 having a central segment 16, a first side arm 18 extending downward and forward from the central segment 16, and a second side arm 20 spaced apart from the first side arm 18 and also extending downward and forward from the central segment 16. The first side arm 18 is an inner side arm and the second side arm 20 is an outer side arm.

[0169] The device 10 also includes a base 22 supporting the control bar 14 and connected to the control bar 14 at flexible, bendable joints 24A, 24B. The base 22 is continuous and extends between and connects to the first side arm 18 and the second side arm 20. The base 22 is continuous because it is not interrupted or connected to other components as it extends from the first side arm 18 to the second side arm 20. The base 22 has a central segment 26, a first base arm 28, and a second base arm 30, all disposed in a common plane. When the base 22 of the device 10 rests on a horizontal surface, the common plane P is parallel to the horizontal surface, and... Figure 3The plane is best indicated by the dashed line P, which represents a plane perpendicular to the page of the drawing. The first base arm 28 and the second base arm 30 are spaced apart, and both extend from the central segment 26 of the base 22. Figure 2 As shown, the base 22 is positioned slightly below the control bar 14, thereby providing stability to the device 10 during pressure.

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

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

[0172] Control bar 14 is biased to Figure 1 , Figure 2 and Figure 3 The unloaded position is shown in the diagram. 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 to remain in the stress-free position in its natural state (without external load applied to it), 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... Figure 3 The distance D1 from the top of the central segment 16 to the bottom of the base 22 is shown in the figure. The stress-free position is the position where the device 10 is in a relaxed, unloaded state (i.e., no vertical force is applied to the control bar 14). The control bar 14 can... Figure 4 The foot 46 is pressed down under the applied force F shown, which represents the force F applied when the foot 46 is inserted into the foot receiving cavity 47 of the footwear article 12 (see...). Figure 5 and Figure 6 During loading, the force is applied by the foot 46. When loaded in this manner, the control bar 14 elastically bends to the loading position, in which the central segment 16 is a second distance D2 from the base 22. When the device 10 is in the loading position, the device 10... Figure 3The distance is indicated by a dashed line and reference number 10A. The second distance D2 is less than the first distance D1. The difference between distances D1 and D2 is the deflection of device 10, which can be, but is not limited to, a deflection of 30 mm. Device 10 is configured such that when it is pressed down to the loading position D2 under the action of a force, it elastically bends at the joints 24A and 24B, thereby storing elastic energy. When the force F is removed, the stored elastic energy causes the control bar 14 to return to the stress-free position. Figure 3 Only the device 10 and the sole structure 32 are shown in the text. The upper 38 described herein has been removed to clearly show the location of the devices 10 and 10A.

[0173] As in Figure 5 and Figure 6 As shown, footwear article 12 includes a sole structure 32 and an upper 38 attached to the sole structure 32. The 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 the outsole and midsole (which may be referred to as a unisole). Figure 5 and Figure 6 In this design, the sole 34 can be a midsole or a single piece of sole. The sole 34 is located below the upper 38. The lower portion 40 of the upper 38 is attached to the sole 34, for example, by adhesive or other means. The base 22 is attached to the sole 34, for example, by adhesive bonding, thermal bonding, or other means. The sole 34 may have minute recesses formed on its outer surface, which is shaped to allow the base 22 and the joints 24A, 24B to partially sit in these recesses, thereby being further supported by the sole 34.

[0174] A flexible footwear upper 38 defines at least a portion of the ankle opening 39. A base 22 is located below the control strip 14 and is secured to the upper 38, wherein a first side arm 18 is secured to the inner side 41 of the footwear upper 38, and a second side arm 20 is secured to the outer side 43 of the footwear upper 38. (As in...) Figure 5 and Figure 6 As best represented in the image, the base 22 extends from the outer side 43 to the inner side 41 around the rearmost portion of the footwear upper. The central segment 16 of the control strip 14 is secured to the footwear upper 38 behind the ankle opening 39. The device 10 may have a thinned portion 45 (in... Figure 3 (as best shown in the image), which allows the footwear upper 38 to be machine-stitched to the device at the thinned portion 45.

[0175] The upper 38 may include a flexible overlay 42 (also referred to as a flexible overlay layer) for receiving and covering the foot 46 supported on the insole 34. Figure 4(As shown in the diagram). For example, the flexible overlay 42 can be a stretchable fabric, such as four-way stretch nylon, that provides a lightweight and breathable feel. The footwear article 12 is characterized by the absence of a rigid heel stabilizer located between the control strip 14 and the base 22 at the rear of the joints 24A, 24B between the control strip 14 and the base 22. The device 10 functions as a heel stabilizer at least in some respects because it helps to keep the wearer's heel in proper position above the heel portion of the sole structure, thus preventing medial or lateral displacement during use. Because the device 10 is attached to the flexible overlay 42, the device 10, together with the flexible overlay 42 of the upper 38, can be referred to as a footwear upper. In other words, the device 10 can be considered a component of a multi-part footwear upper, which also includes the flexible overlay 42 and other components of the footwear article. The multi-part footwear upper can also be referred to as a footwear upper assembly.

[0176] Traditionally, allowing the foot to slide 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 heel stabilizers made of flexible fabric that are not secured to the rear of the ankle opening. 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. Entry is possible solely using the foot 46. Specifically, as in Figure 4 As shown, a force F is applied to the control bar 14 using the bottom of the foot 46, causing the device to elastically bend at joints 24A and 24B, thereby moving the control bar 14 from a stress-free position to a loaded position, indicated by the control bar in position 14A. The upper 38 is attached to the central segment 16 and moves downward together with the control bar 14. When the foot 46 is fully moved into the foot receiving cavity 47, the elastic energy stored due to the bias of the device 10 automatically returns the device 10 to the stress-free position, causing the upper 38 to be automatically pulled up on the rear of the foot 46. Figure 5 The image shows the position of the stretchable flexible cover 42 before insertion into the foot. When the device 10 returns to the stress-free position, the flexible cover 42 extends over the rear portion of the heel of the foot 46. Figure 5 The position indicated by the dashed line is 42A.

[0177] To further facilitate the entry of the foot 46 into the foot receiving cavity 47 of the upper 38, such as Figure 2 and Figure 4As shown, the central segment 16 of the control strip 14 has a ramp surface 50 that slopes toward the inner periphery 52 of the central segment 16. Between the upper portion 54 of the foot contact surface of the control strip 14 and the ramp surface 50, the slope of the central segment 16 changes at the transition line 51. The ramp surface 50 has a steeper incline than the upper portion 54, thereby facilitating the downward and inward sliding of the foot 46.

[0178] refer to Figure 5 and Figure 6 When the control bar 14 is in the stress-free position, the first side arm 18 and the second side arm 20 extend relative to the common plane P of the base 22 at a first acute angle A1. Angle A1 can be measured along the longitudinal axis of each side arm. Although shown at the same angle A1, each of the first side arm 18 and the second side arm 20 can have a first acute angle with a different value. When the control bar 14 is pressed down, causing the device 10 to be in a stress-free position... Figure 3 At position 10A, the first side arm 18 and the second side arm 20 extend relative to the common plane P of the base 22 at a second acute angle A2. Angle A2 can be measured along the longitudinal axis of each side arm. The second acute angle A2 is smaller than the first acute angle A1. Although shown at 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 device 10 is selected to provide the ability to elastically deform by the described elastic bending and to store potential energy, such as elastic energy, that allows device 10 to return to a stress-free 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 Corporation in King of Prussia, Pennsylvania, USA. Another example material is glass fiber reinforced polyamide. Example glass fiber reinforced polyamide is available from Arkema Corporation in King Prussia, Pennsylvania, USA. BZM 70TL. This glass fiber reinforced polyamide has a density of 1.07 g / cm³ under ISO 1183 test method, an instantaneous hardness of 75 according to Shore D standard under ISO 868 test method, a tensile modulus of 1800 MPa under ISO 527 test method (sample conditioned for 15 days at 23°C and 50% relative humidity), and a flexural modulus of 1500 MPa under ISO 178 test method (sample conditioned for 15 days at 23°C and 50% relative humidity).

[0180] Furthermore, the relevant dimensions and shapes of the device at the joint 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 stress-free position. The device 10 can be configured to elastically bend under a force of up to 160 N. For example, refer to... Figure 1 The first side arm 18 and the second side arm 20 each have a thickness T1 at their respective joints 24A and 24B that is greater than the width W1. The thickness T1 is measured in the front-to-back (longitudinal) direction of the footwear 12. The width W1 is measured in the inside-to-outside (lateral) direction of the footwear 12. The greater thickness T1 increases the force required to elastically bend the device 10 to the loading position.

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

[0182] Device 10 is also configured to widen as it moves from a stress-free position to a loaded position. When the control bar 14 is pressed down, this facilitates insertion of the foot 46 into the flexible upper 38 as the first side arm 18 and the second side arm 20 bend apart, thereby pulling the upper 38 attached to the inward-facing surface 60 outward. The bending of device 10 in the loaded position 10A... Figure 2 The plan view is shown.

[0183] Although the device 10 is thus configured to facilitate foot entry by utilizing its ability to rebound and store elastic energy, it is also configured to limit the amount of deformation to prevent plastic deformation. More specifically, the control bar 14 has an extension 70 that extends generally toward the base 22. When the control bar 14 is in Figure 1 In the stress-free position, the extension 70 is spaced apart from the base 22, and when the control bar 14 is pressed down and the device is in the loaded position 10A, the extension 70 contacts the base 22. Figure 3In the diagram, extension 70 is designated as 70A, with device 10 in the loading position 10A. Contact between extension 70 and base 22 limits further downward pressure on control bar 14. Optionally, base 22 may have extensions in place of or other than control bar 14, wherein the extensions on the base extend toward control bar 14.

[0184] exist Figures 1 to 6 In this embodiment, the control bar 14 and the base 22 have complementary features that engage during pressure on the control bar 14 to limit movement of the device. For example, the extension 70 engages with the base 22 to limit pressure on the control bar 14 and to limit the control bar 14 from tilting toward the outer or inner side during loading. More specifically, the base 22 has a recess 72, and when the control bar 14 is pressed down and the device 10 elastically deforms to the loading position 10A, the extension 70 protrudes into the recess 72 and contacts the base 22. When in the recess 72, a side protrusion 74 on either side of the recess 72 prevents lateral movement of the extension 70. Because the control bar 14 typically descends along an arc when the joints 24A, 24B bend, the extension 70 is positioned such that when it descends along such an arc, the extension 70 will engage with the base 22 in the recess 72.

[0185] Figure 7 and Figure 8 Another embodiment of a footwear article 112 with a heel spring device 110 is shown. The heel spring device 110 has similar functions and features to the heel spring device 10. The connectors 124A and 124B have a greater thickness T2 than the thickness T1 of the connectors 24A and 24B, and therefore can provide greater resistance to the downward pressure of the control strip 14, thereby reducing the need for limiting the bending of the extension 70. The central segment 16 has a hole 145, and the upper 38 has a heel tab 149 extending through the hole 145 to further secure the upper 38 to the device 110. After insertion through the hole 145, the heel tab 149 can be wrapped around the device 110, can be loosely suspended, or can be sewn or fastened to the upper 38 or itself to secure the upper 38 to the device 10.

[0186] Figure 9 Another embodiment of footwear article 212 is shown, which has a heel spring device 210 fixed to the sole 234. The heel spring device 210 has similar functions and features to the heel spring device 10. The upper is not shown, but will be fixed to the sole 234 and device 210, as described with respect to device 10.

[0187] Figure 10Another embodiment of footwear article 312 is shown, which has a heel spring device 310 fixed to a sole structure 334 and an upper 338. The sole structure 334 is a sole interlayer, and the upper 338 has a flexible overlay of elastic, stretchable material in the heel region. The heel spring device 310 has similar functions and features to heel spring device 10. The heel spring device 310 may include a base 322 similar to base 22 but passing through the sole structure 334, or a base arm that terminates in and is sufficiently fixed to the sole structure 334, such that the sole structure serves as a base. The device 310 is integrated into the fastening system of the upper 338 because it has a ring 339 fixed to a side arm, which serves as an anchor for fastening cable 343.

[0188] Figures 11 to 14 Another embodiment of footwear article 412 is shown, which has a heel spring device 410 having similar function and features to heel spring device 10. The heel spring device 410 is attached to a sole 434 and an upper 438, the upper 438 having a flexible cover 442 of elastic, stretchable material in the heel area for receiving and covering the foot supported on the sole 434. For example, the flexible cover 442 may be an elastic, stretchable fabric, such as four-way stretch nylon. A foam collar 435 is attached to the flexible cover 442 and defines a front portion of an ankle opening 439 in the upper 438. The foam collar is stiffer than the elastic, stretchable fabric of the flexible cover 442. The collar 435 may include a foam padding 435A. The foam padding 435A in the rear portion of the collar may project inwardly into the ankle opening 439. Because the foam is compressible, the size of the opening can be adjusted to accommodate different ankle girths.

[0189] The central segment of the control strip 414 of device 410 has a thinned portion 445, wherein the flexible covering 442 of the upper 438 is sewn to device 410. (As...) Figure 14 As shown, the foam collar 435 is also sewn to the device 410 at the thinned portion 445. (As shown) Figure 12 As shown, an additional 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. A stitch 437 passes through the thinned portion 445 and through the extension 441. Figure 13 and Figure 14The upper 438 is shown in the diagram. It is characterized by the absence of a rigid heel stabilizer. Device 410 functions as a heel stabilizer, at least in some respects, as it helps to keep the wearer's heel in the proper position at the top of the heel portion of the sole structure, thus preventing medial or lateral displacement during use. Similar to device 10, device 410 has a ramp surface 450 to facilitate foot entry.

[0190] Figure 15 Another embodiment of footwear article 512 is shown, which has a heel spring device 510 having similar function and features to heel spring device 10. The heel spring device 510 is attached to a sole 534 and an upper 538, the upper 538 having a flexible cover 542 of elastic, stretchable material in the heel area for receiving and covering the foot supported on the sole 534. When the foot is inserted, the cover 542 extends to position 542A. For example, the flexible cover 542 may be an elastic, stretchable fabric, such as four-way stretch nylon. 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 the upper 538 above the sole 534, as shown.

[0191] Figure 16 Another embodiment of footwear article 612 is shown, which has a heel spring device 610 having similar function and features to heel spring device 10. The heel spring device 610 is attached to a sole 634 and an upper 638, the upper 638 having a flexible cover in the heel area made of an elastic, stretchable material for receiving and covering the foot supported on the sole 634. For example, the flexible cover can be an elastic, stretchable fabric, such as four-way stretch nylon. The sole 634 has molded recesses on its inner and outer surfaces, in which the base of device 610 and a connector, such as connector 624B, are partially seated.

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

[0193] Figure 19Another embodiment of footwear article 812 is shown, which includes a heel spring device 810 having similar function and features to heel spring device 10. The heel spring device 810 is fixed at its base to the sole 834 and to a flexible cover of the upper 838. A heel tab 849 fixed to the upper forms a loop through which the device 810 passes to the rear of the ankle opening, thereby facilitating the securing of the upper 838 to movement with the device 810.

[0194] Figures 20 to 22 Another embodiment of footwear article 912 is shown, which includes a heel spring device 910 having similar functions and features to heel spring device 10. The heel spring device 910 is fixed at its base to the sole (not shown) and to a flexible cover of the upper 938. The device 910 has a control strip 914 with side arms 918, 920 and a base 922 connecting the side arms 918, 920 and located below the control strip 914. The base 922 extends rearward from the joints 924A, 924B between the control strip 914 and the base 922 to serve as a support. The base 922 lies below a foot receiving space in the upper to which the heel spring device 910 is fixed and can be located below the gusset in the footwear article 912. The base 922 can be fixed to the sole by adhesive bonding or other means, or it can simply be sandwiched between the sole and the gusset or upper material to reduce the need for adhesive. When the control strip 914 is pressed down, the device 910 widens laterally outward, as shown by the device 910 being in the loading position 910A.

[0195] Figure 23 An example diagram is shown, illustrating a vertical force F in Newtons on the vertical axis relative to a displacement D in millimeters on the horizontal axis. This schematically represents the elastic bending and energy return behavior of any heel spring device shown and described herein. The displacement D is, for example,... Figure 3 The difference between the mid-distances D1 and D2. A first example of the behavior of the heel spring device is represented by loading curve 1003 ( Figure 4 The force F is placed on the control bar of the device (its vertical component is shown in the figure), and then shown by the unloaded curve 1002 (behavior when force F is removed). A second example 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 footwear article 1012 is shown, which includes a heel spring device 1010 having similar functions and features to the heel spring device 10. The heel spring device 1010 is fixed at its base to the sole (not shown) and to a flexible cover of the upper 1038. The device 1010 has a control strip 1014 with side arms 1018, 1020, and a base 1022 connecting the side arms 1018, 1020 and located below the control strip 1014. The base 1022 extends rearward from the junction of the control strip 1014 and the base 1022 to serve as a support. The base 1022 may be located below the gusset in the footwear article 1012 and may be fixed to the sole by adhesive bonding or other means, or it may simply be sandwiched between the sole and the gusset or upper material to reduce the need for adhesive. The side arms 1018 and 1020 of device 1010 are similar to those of device 910, except that the side arms 918 and 920 extend from the base 922 to the central segment of the control bar 914 at a gradually decreasing slope, as shown below. Figure 21 As best shown in the diagram, the side arms 1018 and 1020 extend from the base 1022 to the central segment of the control bar 1014 with a gradually increasing slope, as... Figure 25 It is best shown in the middle.

[0197] Figures 26 to 27 Another embodiment of footwear article 1112 is shown, which includes a heel spring device 1110 having similar functions and features to heel spring device 10. The heel spring device 1110 is fixed at its base to the sole (not shown) and to a flexible cover of the upper 1138. The base 1122 may be located below the gusset in footwear article 1112 and may be fixed to the sole by adhesive bonding or other means, or may simply be sandwiched between the sole and the gusset or upper material to reduce the need for adhesive. Device 1110 has a control strip 1114 with side arms 1118, 1120 and 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-shaped form, such as... Figure 27As best shown, as they advance from joints 1124A, 1124B to the central segment of control bar 1114, they first extend rearward, then forward, and then rearward again. The junction of the rearward extension with the forward extension of the side arms 1118, 1120 can serve as an additional junction for elastic bending caused by a downward force acting on the central segment of control bar 1114 during loading of device 1110. Base 1122 extends rearward from the junction of control bar 1114 and base 1122 to serve as a support.

[0198] Figures 28 to 29 Another embodiment of a heel spring device 1210 for footwear articles is shown. The heel spring device 1210 has a control bar 1214, which includes an inner arm 1218 and an outer arm 1220. The control bar 1214 can be attached to a flexible footwear upper. A base 1222 extends from and supports the control bar 1214. Unlike other embodiments of the heel spring device disclosed herein, the base 1222 extends from a central segment of the control bar 1214, and the engagement is between a generally vertical portion and a generally horizontal portion of the base 1222.

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

[0200] Figure 32Another embodiment of footwear article 1412 is shown, which includes a heel spring device 1410 having similar function and features to heel spring device 10. The heel spring device 1410 has a control strip 1414 that is fixed to a flexible cover of footwear upper 1438. The control strip 1414 includes an inner arm and an outer arm (one side arm 1420 is shown). The device 1410 includes a base (not shown) connecting to the side arm and extends through an opening 1436 in the sole 1434 and is fixed or embedded in the sole 1434. The base may be located below the gusset in footwear article 1412 and may be fixed to the sole 1434 by adhesive bonding or other means, or may simply be sandwiched between the sole 1434 and the gusset or upper material to reduce the need for adhesive. Thus, the sole 1434 portion serves as both the base and the junction with the control arm 1414.

[0201] Figure 33 Another embodiment of footwear article 1512 is shown, which includes a heel spring device 1510 having similar function and features to heel spring device 10. The heel spring device 1510 has a control strip 1514 sewn to a flexible cover of footwear upper 1538. The control strip 1514 includes an inner arm and an outer arm (one side arm 1520 is shown). The device 1510 includes a base (not shown) connecting to the side arm and extends through an opening in the sole 1534 and is embedded in or otherwise secured to the sole 1534. The base may be located below the gusset in footwear article 1512 and may be secured to the sole 1534 by adhesive bonding or other means, or it may simply be sandwiched between the sole 1534 and the gusset or upper material to reduce the need for adhesive. Therefore, the sole 1534 is partially used as the base of the control arm and the joint 1524 with the control arm.

[0202] Figures 34 to 35 Another embodiment of a heel spring device 1610 for footwear articles is shown. The device 1610 has a control strip 1614 including an inner arm 1618 and an outer arm 1620 extending from a central segment 1616 of the control strip 1614. The control strip 1614 can be attached to a flexible footwear upper. The central segment 1616 and the outer arms 1618, 1620 have holes 1645 for sewing the device 1610 to the flexible footwear upper behind an ankle opening (such as at the rear collar of the ankle opening) to prevent the heel tab from folding inward in that area during foot insertion. The device 1610 has no base. However, the outer arms 1618, 1620 can be secured to portions of the upper 1638 near their distal ends, such as... Figure 35As shown, there is a slightly stiffer but resilient flexible portion 1635 in front of the four-way stretched 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 resilient return of the device 1610 to a stress-free position after a downward force is applied during foot insertion.

[0203] Figure 36 It shows the use of Figures 37 to 38 Another embodiment of the heel spring device 1710 of the footwear article 1712 shown. The heel spring device 1710 has similar functions and features to the heel spring device 10. The device 1710 has a control bar 1714, which has a central segment 1716, an inner arm 1718, and an outer arm 1720. The device 1710 has a continuous base 1722 that connects the side arms 1718 and 1720 and extends forward from the joint between the control bar 1714 and the base 1722.

[0204] like Figure 37 As shown, the heel spring device 1710 is secured to the sole structure 1732 at its base 1722 and to the flexible cover of the footwear upper 1738 (shown in dashed lines). The upper 1738 defines at least a portion of the foot receiving space 1747 and the ankle opening 1739. The base 1722 is located below the foot receiving space 1747 and may be located below the gusset in the footwear article 1712. It may be secured to the sole structure 1732 by adhesive bonding or other means, or it may simply be sandwiched between the sole structure 1732 and the gusset or upper material to reduce the need for adhesive. The base 1722 extends slightly rearward from the junction of the control strip 1714 and the base 1722, and extends forward from the junction with the control strip 1714 to serve as a support. The base 1722 has a forward-extending protrusion 1727 located below the foot receiving space on the inner side 1741 of the footwear upper, and a rearward-extending protrusion 1729 located below the foot receiving space along the outer side 1743 of the footwear upper.

[0205] Figure 37 The control bar 1714 is shown being biased to a stress-free position. Figure 38 The diagram shows the control bar 1714 elastically bending to a loaded position under applied force, thereby widening the ankle opening 1739. The device 1710 stores elastic energy that returns the control bar 1714 to a stress-free position when the applied load is removed.

[0206] Figures 39 to 40Footwear article 1812 with heel spring device 1810 is shown. Footwear article 1812 and heel spring device 1810 are similar in many respects to footwear article 1712 and heel spring device 1710, with similar reference numerals used to refer to similar parts. Heel spring device 1810 is similar to heel spring device 1710 in all respects, except that heel spring device 1810 has a continuous base 1822, base 1822 having a main portion 1831 and a protrusion 1833 in a recess 1835 in a surface 1837 facing the foot in the sole structure 1732 extending downward from the main portion. Protrusion 1833 is configured to be located in the recess 1835. The wall of protrusion 1833 abuts against the wall of sole structure 1732 in the recess 1835, thereby providing stability to base 1822. Additionally, the protrusion 1833 forms a cavity 1839 in the recess 1835, and this cavity can be used to house various footwear components or accessories, such as electronic accessories.

[0207] Figure 41 It shows the use of Figures 42 to 43 Another embodiment of the heel spring device 1910 of the footwear article 1912 shown. The heel spring device 1910 has similar functions and features to the heel spring device 10. The device 1910 has a control bar 1914 with an inner arm 1918 and an outer arm 1920. The device 1910 has a continuous base 1922 that connects the side arms 1918 and 1920 and extends forward and backward from the joint between the control bar 1914 and the base 1922.

[0208] like Figure 42 As shown, the heel spring device 1910 is fixed at its base 1922 to the sole structure 1732 and to the flexible cover (shown in dashed lines) of the footwear upper 1738, both of which are references. Figure 37 The base 1922 is located below the foot receiving space 1747 and may be located below the gusset in the footwear article 1912. It may be fixed to the sole structure 1732 by adhesive bonding or other means, or it may simply be sandwiched between the sole structure 1732 and the gusset or upper material to reduce the need for adhesive.

[0209] The inner arm 1918 and the outer arm 1920 each have at least one slot 1980 extending through them, and in the illustrated embodiment, multiple slots 1980 are present. The slots 1980 extend through the first side arm 1918 and lengthwise along the longitudinal axis of the inner arm 1918 (i.e., along the length of the side arm 1918). Separate slots 1980 extend through the outer arm 1920 and lengthwise along the longitudinal axis of the outer arm 1920 (i.e., along the length of the side arm 1920). The slots 1980 reduce the thickness of the side arms 1918 and 1920, and thus reduce the force required to bend them. More specifically, using the slots 1980, each side arm is divided into multiple strips 1981 at the slot. The strips 1981 serve as multiple thinner side arms that bend along their length within the area of ​​the slot 1980. Figure 42 The control bar 1914 is shown being biased to a stress-free position. Figure 43 The diagram shows the control bar 1914 elastically bending to the loaded position under applied force, which, compared to the unloaded position, widens the ankle opening 1739 and tilts the ankle opening downwards and backwards. (As shown) Figure 43 As shown, in the loaded position, the side arms 1918, 1920 can be configured such that at least a portion of the groove 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 returns the control bar 1914 to a stress-free position when the applied load is removed.

[0210] Figure 44 It shows the use of in Figures 45 to 46 Another embodiment of the heel spring device 2010 of the footwear article 2012 shown. The heel spring device 2010 has similar functions and features to the heel spring device 10. The device 2010 has a control bar 2014 with an inner arm 2018 and an outer arm 2020. The device 2010 has a continuous base 2022 that connects the side arms 2018 and 2020 and extends forward and backward from the junction of the control bar 2014 and the base 2022.

[0211] like Figure 45 As shown, the heel spring device 2010 is fixed to the sole structure 2032 at its base 2022 and to the flexible cover of the upper 1738 (shown in dashed lines), both of which are references. Figure 37 The base 2022 is located below the foot receiving space 1747 and may be located below the gusset in the footwear article 2012. It may be attached to the sole structure 2032 by adhesive or other means, or it may simply be sandwiched between the sole structure 2032 and the gusset or upper material to reduce the need for adhesive.

[0212] The inner arm 2018 and the outer arm 2020 each have at least one slot 2080 extending through them, and in the illustrated embodiment, multiple slots 2080 are provided. The slots 2080 extend through the inner arm 2018 and are transverse to the longitudinal axis 23A of the inner arm 2018 (i.e., transverse to the length of the side arm 2018). Separate slots 2080 extend through the outer arm 2020 and are transverse to the longitudinal axis 23B of the outer arm 2020 (i.e., transverse to the length of the side arm 2020). The slots 2080 reduce the thickness of the side arms 2018 and 2020, and thus reduce the force required to bend them. More specifically, using the slots 2080, each side arm is divided into multiple fingers 2081 at the slot 2080. The fingers 2081 are used to reduce the thickness of the curved portions of the side arms 2018, 2020 to the thickness between the end 2083 of each groove 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. The fingers 2081, the end 2083, and the surfaces 2085, 2087 are... Figure 44 The inner arm 2020 is marked relative to the outer arm, and the same applies to similar features of the inner arm 2018. Figure 45 The control bar 2014 is shown being biased to a stress-free position. Figure 46 The control bar 2014, elastically bent to the loaded position under applied force, is shown; compared to the unloaded position, the ankle opening 1739 widens. (See diagram.) Figure 46 As shown, in the loaded position, the side arms 2018, 2020 can be configured such that at least a portion of the groove 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 returns the control bar 2014 to a stress-free position when the applied load is removed.

[0213] Figures 47 to 48 Another embodiment of the heel spring device 2110 is shown, which has a connection with the heel spring device 10 and Figure 27 It has similar functions and features to the heel spring device. Figure 48 In the image, device 2110 is shown as part of a footwear article 2112 that is fixed to a flexible covering (shown in dashed lines) of a sole structure 2132 and a footwear upper 2138, both of which are similar to those in the reference image. Figure 37The described contents. The heel spring device 2110 is similar to the heel spring device 1110 in all respects, except that it has a base 2122 that extends forward and backward from the side arms 1118, 1120 of the control bar 1114, unlike the base 1122 that only extends backward.

[0214] Figure 49 Footwear article 2212 with another embodiment of heel spring device 2210 is shown. Heel spring device 2210 has similar functions and features to heel spring device 10. Device 2210 has a control bar 2214 having an inner arm 2218, an outer arm 2220, and a central segment 2216 connecting the side arms 2218, 2220, and the side arms extending generally downward and forward from the central segment 2216. Similar to that described with respect to device 10 and footwear article 12, device 2210 is fixed to a flexible footwear upper 2238 and a sole structure 2232.

[0215] When footwear 2212 is in Figure 49 When positioned on the sole structure, pin 2290 is generally horizontal. Pin 2290 extends laterally through sole structure 2232 and serves as a continuous base, connecting to side arms 2218, 2220 at a first joint and a second joint. Pin 2290 connects to the inner and outer arms 2218 and 2220 at their mating points with sole structure 2232. Pin 2290 establishes a pivot axis along its length (transverse to sole structure 2232), about which control arm 2214 pivots between a stress-free position and a loaded position. A biasing element, such as torsion spring 2291, is wound around pin 2290, with one end fixed to pin 2290 and the other end fixed to sole structure 2232. For example, pin 2290 has a first end 2292 fixed to the inner side of the sole structure and a second end 2294 fixed to pin 2290. Control bar 2214 pivots to the loaded position to wind torsion spring 2291, thereby storing potential energy.

[0216] Control bar 2214 is biased to the stress-free position, shown in solid line. When device 2210 pivots to the loaded position under applied force, control bar 1714 is shown in dashed line as 2214A, in which position the device is indicated as 2210A. Ankle opening 2739 widens in the loaded position and can tilt downwards and backwards relative to the unloaded position because the flexible overlay 2442 (also called the flexible cover layer) of upper 2238 is attached to control bar 2214 and moves downwards with control bar 2214. Spring 2291 stores spring energy that causes control bar 2214 to return to the stress-free position when the applied load is removed.

[0217] Figures 50 to 51 A footwear article 2312 with another embodiment of a heel spring device 2310 is shown. The heel spring device 2310 has similar functions and features to the heel spring device 10. The device 2310 has a control bar 2314, which has an inner arm 2318 and an outer arm (not shown, but a mirror image of the inner arm 2318). The device 2310 has a continuous base 2322 that connects to the side arm and extends from the control bar 2314 to a similar... Figure 1 The base 22 extends forward and backward at the joint of the base 2322.

[0218] like Figures 50 to 51 As shown, the heel spring device 2310 is fixed at its base 2322 to the sole structure 32 and to the flexible cover of the footwear upper 38, both of which are references Figures 5 to 6 To describe.

[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 extends through the first side arm 2318, across the central segment 2316, and through the second side arm (as shown in a mirror image of the slot). In the illustrated embodiment, multiple slots 2380 are present. The same slot 2380, extending through the first side arm 2318 and along its longitudinal axis (i.e., along the length of the side arm 2318), also extends through the second side arm and along its longitudinal axis (i.e., along the length of the second side arm). The slots 2380 reduce the thickness of the side arm and thus reduce the force required to bend it. More specifically, each side arm is divided into multiple strips 2381 at the slot via the slots 2380. The slats 2381 serve as multiple thinner side arms that bend along their length in the region of the groove 2380.

[0220] Figure 50 The control bar 2314 is shown being biased to a stress-free position. Figure 51 The diagram shows the control bar 2314 elastically bending to the loaded position under applied force, which, compared to the unloaded position, widens the ankle opening 39 and tilts the ankle opening downwards and backwards. Figure 51As shown, in the loaded position, side arm 2318 (while the second side arm is not shown) can be configured such that at least a portion of the slot 2380 is closed, causing the slats 2381 to contact each other, thereby increasing stiffness. However, when the slats 2381 become contacted due to the closure of the slot 2380, the slats 2381 can slide against each other. Compared to a control bar 2314 without a slot, this sliding allows further bending to continue with reduced stiffness. Figure 51 A slight interlacing at the rear of the stacked slats 2381 is shown, indicating that they have slid relative to each other when the slots are closed. The device 2310 stores elastic energy that returns the control bar 2314 to a stress-free position when the applied load is removed.

[0221] Figure 52 A footwear article 2412 with another embodiment of a heel spring device 2410 is shown. The heel spring device 2410 has similar functions and features to the heel spring device 10. The device 2410 has a control bar 2414 having an inner arm 18 and an outer arm 20, and a central segment 16 connecting the side arms 18 and 20, with the side arms extending generally downward and forward from the central segment 16. The device 2410 has a reference... Figure 1 The continuous base 22 described connects the side arms 18, 20 at the first joint 24A and the second joint 24B. Similar to that described with respect to device 10, device 2410 is fixed to the flexible footwear upper 2438 and the sole structure 2432.

[0222] The central segment 16 has a hole 2445, and the upper 2438 has a heel tab 2449 extending through the hole 2445 to further secure the upper 2438 to the device 2410. The central segment 16 also has an extension 2470 that extends downward from the central segment 16 and can limit the bending of the device 10 by interference from 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) for securing the heel tab 2449 to the extension 2470 using fasteners such as studs, clips, or buttons. Optionally or additionally, the heel tab 2449 can be secured to the mounting surface 2472 of the extension 2470 by adhesive or other means.

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

[0224] Strips 2514 and 2515 can be anchored at their ends to sole structure 2532. Strips 2514 and 2515 are positioned to cross each other on both the inner and outer sides, and are pivotally secured to each other at a connector 2590 (one shown) on the outer and inner sides where they cross. Connector 2590 can be a pin joint. A torsion spring 2591 can be operably secured at the connector. The upper portions of strips 2514 and 2515 can be elastically bent such that when a force (such as the force of the foot entering the upper 2538) is applied to the central segment 2416, the central segments 2416 and 2516 can move in directions spaced apart from each other. The positions of the central segments 2416 and 2516 under load are shown in dashed lines as 2416A and 2516A. Device 2510 stores potential energy, such as elastic energy and / or spring energy, which causes the rear control bar 2514 to return to a stress-free 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 A footwear article 2612 with another embodiment of a heel spring device 2610 is shown. The heel spring device 2610 has similar functions and features to the heel spring device 2310. The device 2610 has a control bar 2614, which has a series of slats 2681 and a plurality of grooves 2680, such as... Figure 55 As best shown in the diagram. Each slat 2681 has a central segment 2616 and an inner arm 2618 (in... Figure 57(Best shown in the diagram) and outer arm 2620. In one or more embodiments, outer arm 2620 and inner arm 2618 may be configured as mirror images of each other. Device 2610 has a continuous base 2622 located below control bar 2614, and the continuous base 2622 connects the side arms 2618, 2620 and extends from control bar 2614 to a similar... Figure 1 The base 22 extends forward and backward at the joint of the base 2622. (As from...) Figure 57 and Figure 58 As can be clearly seen, the device 2610 has a concave inner surface 2611, which is concave in both the inner-outer direction and the vertical direction.

[0226] Footwear article 2612 includes sole structure 2632 and upper 38 with flexible covering (see reference). Figures 5 to 6 (Description). The heel spring device 2610 is secured to the flexible cover of the footwear upper 38 via a strip 2633, the strip 2633 having a chamber 2635, as shown in the reference. Figures 59 to 60 As described.

[0227] like Figure 54 As shown, the heel spring device 2610 is also fixed to the sole structure 2632 at the base 2622 of the heel spring device 2610. Figures 55 to 56 As shown, 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... Figure 55 , Figure 56 It is shown as extending on the outer surface of the base 2622, and in a mirror image of the outer surface, around the inner surface of the base 2622. Figure 54 The shape and dimensions of the peripheral recess 2622A shown are designed to receive the 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 bar 2614 is biased to Figure 55 The unloaded position shown, and elastically bent under the applied force F. Figure 56In the loaded position shown, each central segment 2616 is closer to the base 2622 than in the unloaded position, thus storing potential energy that causes the control bar 2614 to return to the unloaded position when the applied force F is removed. The control bar 2614 and the base 2622 are constructed as fully elliptical leaf springs. The device 2610 can be made of flexible, bendable nylon or another flexible, bendable material. The central segments 2616 are spaced apart from the base 2622, and the device 2610 is characterized by a junction 2624A between the inner arm 2618 and the base 2622. Figure 57 As shown in the image (and as a mirror image of joint 2624B), there is no rigid heel stabilizer located between the central segment 2616 and the base 2622 at the rear of joint 2624B between the outer arm 2620 and the base 2622. Device 2610 functions as a heel stabilizer at least in some respects because it helps to keep the wearer's heel in the proper position at the top of the heel portion of the sole structure, thereby preventing medial or lateral displacement during use.

[0229] like Figure 55 As shown, the groove 2680 reduces the amount of material between the uppermost slat 2681B and the lowermost slat 2681A at the side arm, and thus reduces the force required to bend the side arm. More specifically, through the groove 2680, the slats 2681 serve as multiple thinner side arms that bend along their length in the region of the groove 2680. At the central segment 2616, the lowermost slat 2681A, closest to the base 2622, is shorter from its inner end 2682A to its outer end 2683A than the uppermost slat 2681B, which is furthest from the base 2622. The inner ends 2682A and 2682B are... Figure 57 The middle is represented, and is Figure 55 The image shows a mirror image of the outer ends 2683A and 2683B.

[0230] In one or more embodiments, the lowermost slat 2681A is thinner than the uppermost slat 2681B at any point along its length between its inner and outer ends, which... Figure 55In the exemplary embodiment, this is evident 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 can vary from its inner end to its outer end, and the thickness of slat 2681B can vary from its inner end to its outer end, at any given location between the inner and outer 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 control bar 2614 is in Figures 54 to 55 In the unloaded position, the slats 2681 are spaced apart from each other by slots 2680. At least some portions of the slots 2680 are closed between the slats 2681, such that adjacent central segments 2616 are... Figure 56 The slots 2680 are in contact with each other at the loading position. In the illustrated embodiment, the slots 2680 are closed at the central segment 2616 at the loading position, but can remain open at the side arms 2618, 2620. The slots 2680 are parallel to each other, and the outer side 2644 of the slats 2681 are in contact with each other at the loading position. Figure 55 In the unloaded position shown, they are flush with each other. Compared to the case where the control strip 2614 has multiple strips 2681 with the same total thickness as the multiple strips 2681 from the uppermost strip 2681B to the lowermost strip 2681A, the groove 2680 enables the control strip 2614 to bend with less resistance (i.e., lower stiffness). In the corresponding... Figure 55 In a typical embodiment, when the slats 2681 come into contact due to the closure of the slot 2680, the slats 2681 can slide against each other (but cannot cross over). Compared to a control bar constructed in the manner of a control bar 2614 but without a slot, sliding allows further bending to continue with reduced stiffness. Figure 56 The slight interlacing of the rear of the stacked slats 2681 is shown to indicate that they slide relative to each other when the slot 2680 is closed.

[0232] Figure 55 The control bar 2614 is shown to be biased to a stress-free (i.e., unloaded) position. Figure 56 The diagram illustrates how the control bar 2614 elastically bends to a loaded position under an applied force F (e.g., due to the force of the foot slipping into the shoe). This loaded position, compared to the unloaded position, allows the upper 38 to move together with the control bar 2614 in the heel area as the shoe moves. Figure 54The ankle opening 39 of the upper 38 widens. When a force F is applied, the heel area of ​​the upper 38 behind the ankle opening 39 moves with the central segment 2616 of the control strip closer to the base 2622, causing the ankle opening 39 to enlarge or at least change its position, such that the ankle opening 39 can tilt downward and backward relative to the unloaded position, and the foot can enter downward and forward from the rear, rather than just downward, as by... Figure 56 The position of the mid-molecular opening 39 and Figure 55 The position of the mid-molecular opening 39 is best shown for comparison.

[0233] More specifically, the upper 38 is connected to the heel spring assembly 2610 via an extension 2684 and a strap having a chamber 2635. (See reference) Figure 55 The lowest slat 2681A has an extension 2684 extending from the 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. For example... Figure 55 As shown, when the control arm 2614 is in the unloaded position, the extension 2684 extends downward and backward. Figure 56 In the loaded position, the extension points more directly downwards than in the unloaded position. Furthermore, the control bar 2614 and the extension 2684 are configured to move away from the base 2622 such that when the control arm 2614 is in the loaded position, the extension is behind the base 2622. In such an embodiment, a recess is not required in the base 2622.

[0234] refer to Figure 54 , Figure 59 and Figure 60The strip 2633 has a proximal end 2633A, which is sewn, integrally formed, or otherwise attached to the upper 38 near the ankle opening 39 at the rear of the upper 38. The strip 2633 has a chamber 2635 at its distal end 2633B. The chamber 2635 can be formed, for example, by folding the strip 2633 over itself at the distal end 2633B and sewing the folded portion to the remainder of the strip 2633. The strip 2633 can extend downward from the upper 38. The strip 2633 is positioned above and behind the control strip 2614, and then an extension 2684 is disposed in the chamber 2635, wherein the strip 2633 covers the central segment 2616. Therefore, the extension 2684 and the strip 2633 are used to operatively connect the upper 38 to the control strip 2614, such that the portion of the upper 38 behind the ankle opening 39 moves downward with the control strip 2614 to a loading position, facilitating the foot to pass through the ankle opening 39 into the foot receiving cavity of the upper 38, and then moves upward with the control strip back to an unloading position when the force F is removed, thereby placing the upper 38 around the rear of the foot that has been inserted into the foot receiving cavity.

[0235] Figure 61 Footwear article 2712 with another embodiment of heel spring device 2710 is shown. Similar reference numerals are used to refer to the same components as described with respect to footwear article 2612 and heel spring device 2610. Heel spring device 2710 has similar functions and features to heel spring device 2610. Device 2710 has control bar 2714, control bar 2714 having a series of slats 2781 and in Figure 63 The multiple slots 2780 are best shown in the image. Each slat 2781 has a central segment 2716, an inner arm 2718 (in... Figure 62A (best shown in) and in Figure 61 The outer arm 2720 is best shown in the image. 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 the reference. Figure 54 and Figure 55 As described, the continuous base 2622 is located below the control bar 2714 and connects to the side arm, extending rearward from the junction of the control bar 2714 and the base 2622. Figure 65 and Figure 66 It can be clearly seen that the device 2710 has a concave inner surface 2711, which is concave in both the inner-outer direction and the vertical direction.

[0236] The groove 2780 reduces the amount of material between the uppermost slat 2781B and the lowermost slat 2781A at the side arm, and thus reduces the amount of force required to bend the side arm via the force F applied to the central segment 2616. More specifically, due to the groove 2780, the slats 2781 serve as multiple thinner side arms that bend along their length within the region of the groove 2780. Figure 61 and Figure 63 As shown, among the slats 2781 closest to the base 2622, the lowermost slat 2781A is shorter from its inner end 2782A to its outer end 2783A than the uppermost slat 2781B from its inner end 2782B to its outer end 2783B, with the uppermost slat 2781B being furthest from the base 2622. The inner ends 2782A and 2782B are... Figure 62A The middle part is represented and is a mirror image of the outer ends 2783A and 2783B.

[0237] At any point along the lowest slat 2781A, the lowest slat 2781A is thinner than any of the other slats at the corresponding point (e.g., at the point directly above the point along the lowest slat), as in Figure 63 The thickness of the slats is best illustrated in the diagram. The thickness of the slats is measured along their longitudinal axis. Although the thickness of slat 2781A can vary along its longitudinal axis from its inner end to its outer end, and the thickness of slat 2781B can vary along its longitudinal axis from its inner end to its outer end, at any given point between the inner and outer ends of slat 2781A, the thickness of slat 2781A will be less than the thickness of slat 2781B at a point directly aligned above the point along slat 2781A.

[0238] When control bar 2714 is in Figures 61 to 62A In the unloaded position, 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 at least one of an elastic compressible material, such as rubber or thermoplastic polyurethane, and may be a foam, but is not limited to these materials. In the illustrated embodiment, the elastic insert 2790 is a thermoplastic polyurethane foam, which provides compressive stiffness and elastic resilience. Figure 64 As best shown, the resilient insert 2790 includes a bushing 2791 having spaced-apart protrusions 2792 extending outwardly on an outer surface 2793 of the bushing 2791. Figure 65As best shown in the diagram, bushing 2791 is configured to extend along the inner side of slat 2781 from the uppermost slat 2781B of slat 2781 to the lower periphery of base 2622. The outer periphery of bushing 2791 coincides with the outer periphery of slat 2781 and base 2622.

[0239] Spaced-apart protrusions 2792 extend from bushing 2791 into grooves 2780 between slats 2781. When device 2710 is in Figure 61 and Figure 62A In the unloaded position, the spaced protrusions 2792 are shaped and sized to completely fill the groove 2780. In other embodiments, the spaced protrusions 2792 may be narrower than the groove 2780. The spaced protrusions 2792 may be flush with the outer surface of the slat 2781, or may extend outward beyond the outer surface of the slat 2781. The slat 2781 and the base 2622 may be referred to as a cage supporting 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 The loading position causes adjacent central segments 2716 to move closer to each other, and the protrusion 2792 is partially compressed between the slats 2781. The bushing 2791 is also compressed as the control bar 2714 moves downward. Because the bushing 2791 and / or the slats 2781 are operatively secured to the heel portion of the flexible covering behind the ankle opening 39 of the upper 38, the upper 38 moves downward together with the bushing 2791 and the control bar 2714 to the loading 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 the insert 2790 is less than the bending stiffness of the slats 2781, and therefore the control strip 2714 is able to bend with a smaller force F compared to the plurality of slats 2781 from the uppermost slat 2781B to the lowermost slat 2781A having the same total thickness (i.e., if the control strip 2714 had no slats).

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

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

[0243] Figure 62A The control bar 2714 is shown to be biased to a stress-free (i.e., unloaded) position. Figure 62B The diagram illustrates how the control bar 2714 elastically bends to a loaded position under an applied force F (such as the force of a foot slipping into the footwear). This loaded position, compared to the unloaded position, allows the upper 38 to move with the control bar 2714 in the heel area. Figure 61 The ankle opening 39 of the upper 38 widens. When a force F is applied, the heel area of ​​the upper 38 behind the ankle opening 39 moves closer to the base 2622 along the central segment 2716 of the slat 2781, causing the ankle opening 39 to enlarge or at least change position by lowering the upper 38 behind the ankle opening 39, so that the ankle opening 39 can tilt downward and backward 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 the base 2622 can be injection molded. Once molded, the slats 2781 and the base 2622 are single, integral parts. The material of the foam insert 2790 can then be injected into the mold cavity containing the molded slats 2781 and the base 2622. Figure 66 Holes 2794 (only some of them are numbered) are shown, in which pins hold slats 2781 and base 2622 against the mold surfaces while material is injected into insert 2790. Insert 2790 is molded around ribs 2795 of base 2622 near the junction of slats 2781 and base 2622, as if by means of... Figure 64 The slot 2796 in the insert 2790 represents this.

[0245] Figure 67Footwear article 2712A with another embodiment of heel spring device 2710A is shown. Heel spring device 2710A is similar to heel spring device 2710 in all respects, except that insert 2790 has a protrusion 2792A, which is configured as a pleat extending outward from the inside of slat 2781 and filling the groove between slats 2781. Slats 2781 and base 2622 may be formed of semi-rigid or rigid thermoplastic polyurethane, while insert 2790 with protrusion 2792A may be formed of a thermoplastic polyurethane that is softer than slats 2781 and base 2622.

[0246] Figure 68 Footwear article 2812 with another embodiment of heel spring device 2810 is shown. Similar reference numerals are used to refer to the same components as described with respect to footwear article 2612 and heel spring device 2610. Heel spring device 2810 has a similar function to heel spring device 2710, but includes an elastic corrugated body 2815, which includes a central segment 2816 and an inner arm 2818 extending downward and forward from the central segment 2816 (in... Figure 69 (best shown in the middle), and the lateral arm 2820 extending downward and forward from the central segment 2816 (in Figure 68 (Best shown in the image). The corrugated body 2815 includes alternating ridges 2881 and grooves 2880, which extend longitudinally along the inner arm 2818, the central segment 2816, and the outer arm 2820. Figure 70 and Figure 71A It can be clearly seen that the device 2810 has a concave shape on its inner surface in both the inner-outer direction and the vertical direction.

[0247] The corrugated body 2815 was biased to Figure 68 , Figure 69 , Figure 70 and Figure 71A The unloaded position is shown. The corrugated body 2815 is compressed under the applied force F to... Figure 71B The loaded position is shown in the diagram. In the loaded position, the corrugated body 2815 is compressed (e.g., by folding) so that adjacent ridges of the alternating ridges 2881 are closer to each other than in the unloaded position, particularly at the central segment 2816, thereby storing elastic energy that causes the corrugated body 2815 to return 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 backward relative to the unloaded position.

[0248] like Figure 68 As shown, the ridges 2881A and grooves 2880A of the first group extend from the inner arm 2818 to the outer arm 2820, while the ridges 2881B and grooves 2880B of the second group extend only along the central segment 2816. The first and second groups are configured such that the ridges and grooves can follow the contour of the upper 38, extending along the entire portion of the upper 38 behind the ankle opening 39, while still allowing some grooves and ridges (i.e., the first group) to extend downward and forward.

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

[0251] If passed Figure 68 As shown by seam 2829, the upper flange 2823 is sewn to the upper 38 behind the ankle opening 39. The upper flange 2823 may optionally be adhesively or thermally bonded to the upper 38. The connection between the heel spring device 2810 and the upper 38 via the upper flange 2823 allows the upper 38 to move together with the heel spring device 2810 between a loaded position and an unloaded position.

[0252] The ridges 2881 and grooves 2880 of the corrugated body 2815 can also be referred to as pleats. The ridge 2881 is the raised pleat of the pleat, while the groove 2880 is the recessed pleat. The device 2810 is a single, integral component comprising the corrugated body 2815 and the flanges 2822 and 2823. The device 2810 can be injection molded from an elastic deformable material (such as at least one of rubber or thermoplastic polyurethane) and can be an elastic foam (such as polymer foam material, etc.), but is not limited to these materials.

[0253] Figure 72 Another embodiment of the heel spring device 2910 within the scope of this teaching is shown. As described with respect to the heel spring device 2710, the heel spring device 2910 has spaced-apart strips 2781 and a base 2622, and is biased to Figure 72 The unloaded position shown, but elastically bending to the loaded position (not shown) in response to an applied load, helps open the ankle opening of the upper to facilitate foot entry as described with respect to the heel spring device 2710. The heel spring device 2910 includes discrete elastic inserts 2990 disposed in slots 2780, but only along a portion of the central segment 2716 (e.g., not disposed in slots on the side arms). A strip 2991 is adhered to or otherwise attached to the inserts 2990 and the strips 2781 to retain the inserts 2990 in proper position within the slots 2780. Alternatively, the strip 2991 may be an integral part of the elastic inserts 2990, such that the elastic inserts 2990 are integrated as a single, integral component.

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

[0255] Figure 74Footwear article 3112 with another embodiment of heel spring device 3110 is shown. Similar reference numerals are used to refer to the same components as described with respect to footwear article 2612 and heel spring device 2610. Heel spring device 3110 has a similar function to heel spring device 2610, but includes a fluid filling bladder 3115, which includes a central segment 3116 and an inner arm 3118 extending downward and forward from the central segment 3116 (shown in...). Figure 75 The middle section 3116 and the outer arm 3120 extending downward and forward from the central segment 3116. The sole structure 2632 is fixed to the lower flange 3122 of the bladder element 3115 by adhesive, heat bonding, or other means, such that the sole structure 2632 is generally located below the upper 38 and the heel spring device 3110, as shown in the image. Figure 74 As shown in the image.

[0256] A downward force F is applied to the central segment 3116 to place the bladder element 3115 in an unloaded position. Figure 77 Move to the loading position ( Figure 78 Unloaded positions are also called extended positions, while loaded positions are also called collapsed or compressed positions. The central segment 3116 may be referred to as the control bar.

[0257] Capsule element 3115 can be thermoformed from first polymer sheet 3117 and second polymer sheet 3119. Figure 76 The capsule element 3115 is best illustrated in the diagram and is also referred to as the inner sheet and outer sheet, or inner layer and outer layer, respectively. Optionally, the capsule element 3115 may be blow-molded from a preformed polymer material. The capsule element 3115 may be formed from any of a variety of polymer materials that hold fluid at a predetermined pressure, including fluids as gases (such as air, nitrogen, or other gases). As used herein, "fluid" includes gases, including air, inert gases such as nitrogen, or other gases. Therefore, "fluid filling" includes "gas filling".

[0258] For example, the capsule element 3115 may be a TPU material, polyurethane, polyurethane, polyester, polyester polyurethane, and / or polyether polyurethane. Furthermore, in one embodiment, the capsule element 3115 may be formed from a sheet with layers of different materials. Sheets 3117, 3119 may be laminates formed from films having one or more first layers comprising thermoplastic polyurethane layers and alternating with one or more second layers, also referred herein as barrier layers, gas barrier polymers, or gas barrier layers. The second layers may include a copolymer of ethylene and vinyl alcohol (EVOH), 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 layers may be arranged to form the outer surface of the polymer sheet. That is, the outermost first layer may be the outer surface of the capsule element 3115. As disclosed in U.S. Patents 5,713,141 and 5,952,065 to Mitchell et al., the capsule element 3115 may also be formed of a material comprising alternating layers of thermoplastic polyurethane and ethylene-vinyl alcohol copolymer. Optionally, the layers may comprise ethylene-vinyl alcohol copolymer, thermoplastic polyurethane, and a re-polished material of ethylene-vinyl alcohol copolymer and thermoplastic polyurethane. Sheets 3117 and 3119 may have alternating layers of thermoplastic polyurethane (TPU) and gas barrier material. In the illustrated embodiments, sheets 3117 and 3119 are transparent.

[0259] Sheets 3117 and 3119 are joined to each other around the periphery of the capsule element 3115 (such as at the upper flange 3123 and the lower flange 3122, also referred to as the base). The lower flange 3122 is continuous and connects and supports the inner arm 3118, the central segment 3116, and the outer arm 3120. Sheets 3117 and 3119 are also joined to each other at various intermediate joining locations 3124 (referred to as webbing). Figure 74 As shown, the upper flange 3123 is thermally bonded, adhesively attached, or otherwise secured to the upper 38 behind the ankle opening 39. The upper 38 may 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 between the heel spring assembly 3110 and the upper 38 via the upper flange 3123 allows the upper 38 to move together with the heel spring assembly 3110 between a loaded and unloaded position. More specifically, the upper 38 moves with the central segment 3116 such that when the heel spring assembly 3110 is in the loaded position, the ankle opening 39 can tilt downwards and backwards relative to the unloaded position, allowing the foot to enter without the hands.

[0260] The sheets 3117 and 3119 combine to form fluid-sealed, pressurized or unpressurized, fluid-filled internal cavities 3181A, 3181B, 3181C, 3183A, and 3183B. In the illustrated embodiment, the fluid-filled internal cavities 3181A, 3181B, 3181C, 3183A, and 3183B are at the ambient pressure of the sealed environment. Optionally, the fluid-filled internal cavities 3181A, 3181B, 3181C, 3183A, and 3183B can be pressurized by introducing fluid into the cavities through one or more subsequently sealed inflation ports (not shown).

[0261] In the illustrated embodiment, each of the fluid-filled internal cavities 3181A, 3181B, and 3181C is generally tubular and extends in the length direction along the inner arm 3118, the central segment 3116, and the outer arm 3120. In some embodiments, cavities 3181A, 3181B, and 3181C extend only along the central segment 3116. Cavities 3181A, 3181B, and 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 inner and outer arms. For example, a plurality of discrete cavities are shaped as tubes shorter than cavities 3181A, 3181B, and 3181C, or have other shapes that may extend along the central segment 3116 and may be fluidly interconnected with each other through channels formed of sheet material.

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

[0263] The molded sheets 3117 and 3119, having internal cavities 3181A, 3181B, 3181C, 3183A, and 3183B, bias the heel spring device 3110 to... Figures 74 to 77 The unloaded position is shown. The heel spring device 3110 is compressed to [a certain position] under the applied force F. Figure 78 The loaded position shown allows for the storage of elastic energy. For example, the applied force F could be the force of the foot when it is inserted into the ankle opening 39 of the footwear 3112. In the loaded position, the bladder element 3115 rebounds because the force F is applied approximately above the central segment 3116 of the tubular cavities 3181A, 3181B, and 3181C, causing the top of the central segment 3116 to be closer to the flange 3122 in the loaded position than in the unloaded position.

[0264] When the tubular cavities 3181A, 3181B, and 3181C are compressed, some fluid within the fluid-filled inner cavities 3181A, 3181B, and 3181C can be transferred to the reservoirs 3183A and 3183B, causing the reservoirs to expand and bulge outwards. Figure 78 This is indicated at reservoir 3183A. When the force F is removed, as the transferred fluid returns from reservoirs 3183A, 3183B to tubular cavities 3181A, 3181B and 3181C, the spring-deformed bladder element 3115 returns to... Figure 77 The unloaded position causes the tubular cavities 3181A, 3181B, and 3181C to expand to their original shapes and the storage units 3183A and 3183B to shrink to their original shapes.

[0265] Figure 79 It shows the use of Figures 80 to 82 Another embodiment of the heel spring device 3210 of the footwear article 3212 shown. The heel spring device 3210 has similar functions and features to the heel spring device 10. For example, the device 3210 has a control bar 14 with an inner arm 18 and an outer arm 20. The device 3210 has a continuous base 22 connecting the side arms 18, 20 and extending rearward from the junction of the control bar 14 and the base 22. The base 22 is located below the control bar 14, wherein the first side arm 18 is located on the inner side 41 of the footwear upper 38, the second side arm 20 is located on the outer side 43 of the footwear upper 38, and the central segment 16 of the control bar 14 is located behind the ankle opening 39 of the upper 38.

[0266] The base 22 supports the control bar 14 and is connected to the control bar 14 at flexible, bendable joints 3224A and 3224B. The base 22 is continuous and extends between and connects to the first side arm 18 and the second side arm 20. The base 22 is continuous because it is not interrupted or connected to other components when extending from the first side arm 18 to the second side arm 20. The base 22 has a central segment 26, a first base arm 28, and a second base arm 30, all of which are disposed in a common plane, as shown in the reference. Figure 3 The device 10 is described. The first base arm 28 is spaced apart from the second base arm 30, and both extend from the central segment 26 of the base 22.

[0267] The joints 3224A and 3224B include a first joint 3224A and a second joint 3224B. The base 22 and the first side arm 18 are connected at the first joint 3224A, and the base 22 and the second side arm 20 are connected at the second joint 3224B. The first joint 3224A is a connector between the first base arm 28 and the first side arm 18. The second joint 3224B is a connector between 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] The control bar 14 has an arcuate shape from the first joint 3224A to the second joint 3224B. Similarly, the base 22 also has an arcuate shape from the first joint 3224A to the second joint 3224B. With this arrangement, the control bar 14 and the base 22 are constructed as a fully elliptical leaf spring as described herein. The device 3210 may be referred to as a heel spring. Furthermore, the device 3210 is a single, integral, one-piece component. For example, the device 3210 can be injection molded as a single, integral, one-piece component.

[0269] The central segment 16 of the control bar 14 has a ramp surface 50 that slopes toward the inner periphery of the central segment 16 between the first side arm 18 and the second side arm 20, and, as described with respect to the device 10, helps to guide the foot downward and forward into the foot receiving cavity 47 during the application of a downward force F to the control bar 16. Furthermore, the first side arm 18 and the second side arm 20 each twist outward along their respective longitudinal axes from the joints 3224A, 3224B near the base 22 to the central segment 16 of the control bar 14. This outward twist facilitates downward and backward movement of the central segment 16 during foot loading.

[0270] Footwear article 3212 includes a sole structure 3232, and a flexible footwear upper 38 having an inner side 41 and an outer side 43, defining an ankle opening 39 and a foot receiving cavity 47, as described with respect to footwear article 12. The 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 an integral combination of the outsole and the midsole and may be referred to as a unisole. The sole layer 3234 is located below the upper 38 and the foot receiving cavity 47 defined by the upper 38. The lower portion 40 of the footwear upper 38 is attached to the sole layer 3234, such as by adhesive or other means. The base 22 is attached to the sole layer 3234, such as by bonding using adhesives, thermal bonding, or other means.

[0271] like Figure 83 As best shown, the sole 3234 has minute recesses 3219 in its outer wall 3217 (i.e., in the outer and rear walls of the heel region of the sole 3234). The recesses 3219 are shaped to allow the base 22 and connectors 3224A, 3224B to partially sit within the recesses 3219. The portions of the base 22 and connectors 3224A, 3224B that are seated in the recesses 3219 are secured to the outer wall 3217 of the sole 3234 within the recesses 3219. Therefore, the device 3210 is supported by the sole 3234 within the recesses 3219.

[0272] Control bar 14 is biased to Figure 80 and Figure 82 The unloaded position is shown herein. The unloaded position is also referred to herein as the stress-free position. Control strip 14, in its formed state, is internally biased to the stress-free position due to its material. In other words, the material of control strip 14 has sufficient rigidity such that it remains in the stress-free position in its natural state without external load applied to it, 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 bottom of the central segment 26 of the base 22, as shown in... Figure 80 The distance D1 is represented by the distance from the top of the central segment 16 of the control bar 14 to the bottom of the central segment 26 of the base 22. The stress-free position is the position where the device 3210 is in a relaxed, unloaded state (i.e., no vertical force is applied to the control bar 14). The control bar 14 can... Figure 80 The foot is pressed down under the action of the force F shown, which represents the foot receiving cavity 47 into the footwear article 3212 (see, for example, see...). Figure 5 and Figure 6The force applied by the foot during loading. When loaded in this manner, the control bar 14 elastically bends to the loading 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 loading position is shown in... Figure 80 In the diagram, control bar 14 and central segment 16 are represented by dashed lines, while the central segment is... Figure 80 The reference numeral 16A is used in the designation. 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 can be, but is not limited to, a deflection of 30 mm. Device 3210 is configured such that when it is pressed down to the loading position D2 under the action of force F, it elastically bends at the joints 3224A and 3224B, thereby storing elastic energy. When force F is removed, the stored elastic energy causes the control bar 14 to return to the stress-free position. Similar to device 10, when the control bar 14 is in the unloaded position, the first side arm 18 and the second side arm 20 extend with respect to the common plane P of the base 22 at a first acute angle A1. When the control bar 14 is pressed down, the first side arm 18 and the second side arm 20 extend with respect to the common plane P of the base 22 at a second acute angle A2. The second acute angle A2 is smaller than the first acute angle A1.

[0273] like Figure 82 As best shown in the image, the base 22 extends from the outer side 43 to the inner side 41 around the rearmost portion of the footwear upper 38. (See image) Figure 82 As shown, device 3210 is not secured to the upper 38 at the inner side 41 or outer side 43. Instead, device 3210 is secured to the upper 38 only via a heel tab 3249, which extends through a hole 3245 in the central segment 16. Next, tab 3249 is sewn to the rear portion 3247 of the upper 38 at seam 3241. A decorative snap 3243 may be secured to tab 3249. However, in the illustrated embodiment, the decorative snap 3243 is purely decorative, as it does not snap or otherwise secure to the upper 38.

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

[0275] Figures 85 to 86Another embodiment of the heel spring device 3310 is illustrated, which has many of the same features as the heel spring devices 10, 3210, which are indicated by similar reference numerals. Furthermore, 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 is generally U-shaped.

[0276] refer to Figure 87 A heel spring device 3310 is included in a footwear article 3312 having an upper 38 and a sole structure 3332. The upper 38 is as described herein with respect to the heel spring device 10, and... Figure 87 The details are shown only in dashed lines. The sole structure 3332 includes an outer insole 3334, which can serve as both an integral outsole and a midsole layer. The sole structure 3332 also includes an inner insole 3345, also known as an insole, that covers the insole 3334. Figure 89 A separate insole 3334 is shown, wherein the inner insole 3345 has been removed. The insole 3334 has a recess 3349 in its upper surface 3347. The recess 3349 is shaped such that a flange 3221 is located in the recess 3349 and is at least partially seated in the recess 3349, and is secured to the upper surface 3347 in the heel region of the sole structure 3332. Figure 90 A flange 3221 is shown located in the recess 3349. A heel spring device 3310 secures the flange 3221 to the upper surface 3347 of the insole 3334 in the recess 3349 by heat bonding, adhesive, or other means, thereby fixing it to the insole 3334. The inner insole 3345 is then inserted into the upper 38 to rest on the insole 3334 above the flange 3221 and on the upper surface 3347 of the insole 3334.

[0277] like Figure 90 As best illustrated, the heel spring device 3310 is asymmetrical about the longitudinal axis L. More specifically, the inner arm 18 bends laterally outward beyond the outer arm 20 and is also longer than the outer arm 20 in the anteroposterior direction (along the longitudinal axis L). As discussed with respect to the heel spring device 3210, this is a more anatomically compliant shape than a symmetrical heel spring device and avoids undesirable friction and pressure on the foot from the side arms 18, 20.

[0278] The heel spring device 3310 is configured to be fixed to the upper 38 at the foremost portion of the side arms 18, 20 via a heel tab extending through a hole 3245 in the central segment 16, as shown. Figure 87The upper 38 is indicated by the dashed line. More specifically, the foremost portion 3371 of the inner surface 3373 of the first side arm 18 includes an inner recess 3374, such that the first side arm 18 is thinner at the inner recess 3374 than behind it. The foremost portion 3375 of the inner surface 3377 of the second side arm 20 includes an outer recess 3376, such that the second side arm 20 is thinner at the outer recess 3376 than behind it. The upper 38 can be secured to the first side arm 18 at the inner recess 3374 and to the second side arm 20 at the outer recess 3376. For example, the upper 38 can be attached to the side arms 18 and 20 at the recesses 3374 and 3376. In some embodiments, such as Figure 88 As shown, 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, which is thinner than the forward portion of the outer portion 38A. The flange 38C engages with and is secured to the inner surfaces 3373, 3377 of the side arms 18, 20 in the recesses 3374, 3376. The outer portion 38A may be less flexible than the inner portion 38B, and therefore can 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 part 38A) at the foremost parts 3371 and 3375, the upper 38 can also be attached via the heel tab 3249 (see...). Figure 87 and Figure 91 The heel tab 3249 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, as shown... Figure 92 The suture 3285 shown is sewn to itself. Then, pin 3283 can be inserted into opening 3281 in the ring of tab 3249. Pin 3283 can be secured to tab 3249 behind hole 3245 in opening 3281, for example, by inserting adhesive into opening 3281. Tab 3249 with pin 3283 can be wider than hole 3245. For example, pin 3283 has a width 3286 greater than the width 3287 of hole 3245 (see...). Figure 91 As pin 3283 is inserted into the annular tab 3249, after the tab 3249 is pulled through the hole 3245, pin 3283 helps to hold the tab 3249 in the 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 pin 3283.

[0280] Figures 93 to 94A heel spring device 3410 is shown, which has many of the same features as heel spring devices 10 and 3210. Similar reference numerals are used to refer to these features. Device 3410 includes a lever 3489 extending laterally outward from control bar 14. Lever 3489 may also be referred to as a ledge extension or shelf. Lever 3489 is positioned partially along the inner arm 18 and partially along the central segment 16. Within the scope of this disclosure, lever 3489 can be positioned anywhere along control bar 14. Lever 3489 has an upward-facing surface 3491, which can be positioned relative to... Figure 80 The force F acting on the central segment 16 in the middle presses down in a similar manner. The pressing lever 3489 helps to press the control bar 14 from a stress-free position to a stress-inducing position. The surface 3491 has recessed grooves 3493, making the surface 3491 uneven, thereby enhancing the gripping ability of the surface 3491 when the pressing lever 3489 is applied. Figure 94 A rear view of a footwear article 3412 is shown, which includes a device 3410 that is fixed to the sole 3434 and the upper 38.

[0281] The various embodiments of the heel spring device disclosed herein enhance the ease of foot entry, thereby allowing the foot to enter footwear items without lifting them by hand.

[0282] The following terms provide example constructions of footwear articles, devices, and footwear uppers disclosed herein.

[0283] Clause 1: An apparatus configured to surround a portion of a foot receiving cavity in the heel region of a footwear article, the apparatus 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 and extending from the central segment; a continuous base supporting the control strip and connected to both the first and second side arms; and wherein the control strip is biased to a stress-free position at a first distance from the base, the control strip elastically deforms under an applied force to a loaded position at a second distance from the base less than the first distance, and the apparatus stores potential energy that causes the control strip to return to the stress-free position when the applied load is removed.

[0284] Clause 2: The apparatus according to Clause 1, wherein the base is connected to the first side arm at a first connector and the base is connected to the second side arm at a second connector.

[0285] Clause 3: The device according to Clause 2, wherein: the control bar 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 bar and the base are constructed as fully elliptical leaf springs.

[0286] Clause 4: The device according to any one of Clauses 2 to 3, wherein: the base has a central segment, a first base arm, and a second base arm, all disposed in a common plane; the first base arm and the second base arm are spaced apart, and both extend from the central segment 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 the stress-free 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 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 according to any one of Clauses 1 to 4, wherein the central segment of the control bar has a ramp surface that slopes toward the inner periphery of the central segment between the first side arm and the second side arm.

[0288] Clause 6: The device according to any one of Clauses 1 to 5, wherein the first side arm and the second side arm are both twisted outward along their respective longitudinal axes from the base to the central segment of the control bar.

[0289] Clause 7: The device according to any one of Clauses 1 to 6, 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.

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

[0291] Clause 9: The device according to Clause 8 is combined with a sole structure having a foot receiving surface having a recess in the heel area; and wherein the flange is disposed in the recess and secured to the foot receiving surface.

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

[0293] Clause 11: The device according to any one of Clauses 1 to 10, which is combined with a footwear upper defining at least a portion of an ankle opening, wherein the base is located below the control strip, the first side arm is located on the inner side of the upper, the second side arm is located on the outer side of the upper, and the central segment of the control strip is located behind the ankle opening.

[0294] Clause 12: The apparatus according to Clause 11, wherein the foremost portion of the inner surface of the first side arm includes an inner recess such that the first side arm is thinner at the inner recess than behind the inner recess, and the foremost portion of the inner surface of the second side arm includes an outer recess such that the second side arm is thinner at the outer recess than behind the outer recess; and wherein the upper is secured to the second side arm at the outer recess and to the first side arm at the inner recess.

[0295] Clause 13: The device according to any one of Clauses 1 to 12, wherein the central segment has a hole; and wherein the upper includes a tab extending through the hole.

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

[0297] Clause 15: The device according to Clause 13 further includes: 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 according to any one of Clauses 1 to 15 further includes: a lever extending outward from the control bar.

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

[0300] Clause 18: The apparatus according to Clause 17, wherein the control bar 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 disposed between corresponding adjacent slats in the slats.

[0301] Clause 19: A device according to any one of Clauses 1 to 16, wherein the device comprises a capsule element comprising one or more fluid-filled internal cavities.

[0302] Clause 20: The apparatus according to Clause 19, wherein: the one or more fluid-filled internal cavities comprise: a cavity extending along the central segment; and one or more reservoirs disposed at one or both of the first side arm and the second side arm and in fluid communication with the cavity extending along the central segment; and the one or more reservoirs expand as fluid transfers from the cavity extending along the central segment when the heel spring device elastically deforms under an applied force.

[0303] Clause 21: The device according to any one of Clauses 1 to 18, wherein when the control bar is in the loaded position, the first side arm and the second side arm are bent separately from each other.

[0304] Clause 22: The device according to any one of Clauses 1 to 18, wherein: one of the control bar and the base has an extension extending toward the other of the control bar and the base; and when the control bar is in the stress-free position, the extension is spaced apart from the other of the control bar and the base, and when the control bar is in the loaded position, the extension contacts the other of the control bar and the base, thereby limiting further downward pressure on the control bar.

[0305] Clause 23: The apparatus according to Clause 22, wherein: the extension extends from the central segment of the control bar toward the base; the base has a recess; and when the control bar is in the stress-free position, the extension is spaced apart from the base, and when the control bar is in the loaded position, the extension protrudes into the recess.

[0306] Clause 24: The device according to Clause 11, wherein the control strip is embedded in the upper of the footwear.

[0307] Clause 25: The device according to Clause 11, wherein the base has a forward-extending protrusion located below the foot receiving space on the inner side of the upper, and a rearward-extending protrusion located below the foot receiving space along the outer side of the upper.

[0308] Clause 26: The apparatus according to Clause 1, wherein the base is coupled to the foremost portions of the first side arm and the second side arm.

[0309] Clause 27: The device according to Clause 1, wherein the base extends rearward from the control bar.

[0310] Clause 28: The apparatus according to Clause 1, wherein the base extends forward from the control bar.

[0311] Clause 29: The device according to Clause 1, wherein the base is a sole structure of a footwear article.

[0312] Clause 30: The device according to Clause 1, wherein the base is a flexible footwear upper.

[0313] Clause 31: A device according to any one of Clauses 1 to 30, wherein the device is a single, integral, or monolithic component.

[0314] Clause 32: A device for facilitating foot entry into a footwear article and configured to surround a portion of a foot receiving cavity in the heel region of the footwear article, the device comprising: a control bar and a base located below the control bar; wherein the control bar comprises a series of slats, each slat having: a central segment; an inner arm extending from the central segment to an inner end connected to an inner surface of the base; and an outer arm extending from the central segment to an outer end connected to an outer surface of the base; and wherein the control bar is biased to an unloaded position and elastically flexes to a loaded position under 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 bar to return to the unloaded position when the applied load is removed.

[0315] Clause 33: The device according to Clause 32, wherein the control bar and the base are configured as fully elliptical leaf springs.

[0316] Clause 34: The apparatus according to any one of Clauses 32 and 33, wherein: the control bar defines a groove extending between the slats; when the control bar is in an unloaded position, the slats are spaced apart from each other by the groove; and one or more of the grooves close between the slats such that one or more adjacent central segments contact each other in the loaded position.

[0317] Clause 35: The apparatus according to Clause 34, wherein: the slots are parallel to each other; and the outer sides of the slats are flush with each other in the unloaded position.

[0318] Clause 36: The device according to any one of Clauses 32 to 35, wherein the lowermost slat closest to the base at the central segment is shorter from the inner end to the outer end than the uppermost slat furthest from the central segment from the inner end to the outer end; and wherein the lowermost slat is thinner than the uppermost slat.

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

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

[0321] Clause 39: The apparatus according to any one of Clauses 32 to 38 further includes: an elastic insert that at least partially fills the groove.

[0322] Clause 40: The device according to Clause 39, wherein the resilient insert comprises: a bushing extending along the inner side of the slat; and spaced-apart protrusions extending from the bushing into the groove.

[0323] Clause 41: The apparatus according to Clause 39, wherein the resilient insert is configured as a pleated member extending outward from the inside of the slats between the slats.

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

[0325] Clause 43: A device for facilitating foot entry into a footwear article and configured to surround a portion of a foot receiving cavity in the heel region of the footwear article, the device comprising: an elastic corrugated body including a central segment, an inner arm extending forward from the central segment, and an outer arm extending forward from the central segment; wherein the corrugated body includes alternating ridges and grooves extending longitudinally along the inner arm, the central segment, and the outer arm; and wherein the corrugated body is biased to an unloaded position and compressed to a loaded position under an applied force, wherein one or more adjacent ridges of the alternating ridges are closer to each other 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.

[0326] Clause 44: The apparatus according to Clause 43, wherein: the corrugated body includes a pleat; and the ridge is a convex pleat of the pleat, while the groove is a concave pleat of the pleat.

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

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

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

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

[0331] Clause 49: A footwear article comprising: an upper defining at least a portion of an ankle opening; a sole structure fixed to and located below the upper; and a heel spring device comprising: a central segment fixed to the upper posterior to the ankle opening; a medial arm extending downward and forward from the central segment; a lateral arm extending downward and forward from the central segment; and a base connected to both the medial arm and the lateral arm; wherein the base is fixed to the footwear article. The sole structure includes a central segment biased to an unloaded position, a heel spring device elastically deforming to a loaded position under applied force, the central segment being closer to the base in the loaded position than in the unloaded position, and the heel spring device storing elastic energy that causes the central segment to return 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: Footwear articles according to Clause 49, wherein: the sole structure includes a sole interlayer; and the base is partially recessed into the sole interlayer.

[0333] Clause 51: Footwear article according to any one of Clauses 49 to 50, wherein the inner arm is fixed to the inner side of the upper and the outer arm is fixed to the outer side of the upper.

[0334] Clause 52. Footwear articles according to Clause 51, wherein, when the central segment is in the loaded position, the inner arm and the outer arm bend laterally outward and separately from each other, thereby widening the ankle opening.

[0335] Clause 53: Footwear article 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 joint between the inner arm and the base and at the rear of the joint between the outer arm and the base.

[0336] Clause 54: Footwear articles according to any one of Clauses 49 to 53, wherein the inner arm and the outer arm are each twisted outward along their respective longitudinal axes from the base to the central segment.

[0337] Clause 55: Footwear article according to any one of Clauses 49 to 54, wherein: one of the central segment and the base has an extension extending 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] Clause 56: Footwear article according to Clause 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] Clause 57: The footwear article according to Clause 55, wherein the extension extends at least partially from the central segment toward the base; and further comprises: a strip having a proximal end fixed to the upper and a chamber at a distal end; and the extension is disposed in the chamber, wherein the strip covers the central segment.

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

[0341] Clause 59: Footwear articles according to any one of Clauses 49 to 58, wherein the central segment has a sloping surface that slopes toward the inner periphery of the central segment between the inner arm and the outer arm.

[0342] Clause 60: Footwear articles pursuant to any one of Clauses 49 to 59, wherein the heel spring device is a single, integral, one-piece component.

[0343] Clause 61: Footwear articles according to Clause 49, wherein the heel spring device includes a bladder element comprising one or more fluid-filled internal cavities.

[0344] Clause 62: Footwear articles according to Clause 61, wherein: the one or more fluid-filled internal cavities comprise: a cavity extending along the central segment; and one or more reservoirs disposed at one or both of the inner arm and the outer arm and in fluid communication with the cavity extending along the central segment; and the one or more reservoirs expand as fluid transfers from the cavity extending along the central segment when the heel spring device elastically deforms under an applied force.

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

[0346] Clause 64: The footwear upper according to Clause 63, wherein the flexible covering is an elastic stretchable fabric, and further comprising a collar attached 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 according to any one of Clauses 63 to 64 further includes: a heel tab secured to a flexible cover; wherein the central segment of the control strip has a hole, and the heel tab extends through the hole.

[0348] Clause 66: Footwear upper according to any one of Clauses 63 to 65, wherein, when the central segment is in the loaded position, the medial arm and the lateral arm bend laterally outward and separately from each other, thereby widening the ankle opening of the flexible cover.

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

[0350] Clause 68: Footwear upper according to any one of Clauses 63 to 67, wherein the inner arm and the outer arm are each twisted outward along their respective longitudinal axes from the base to the central segment 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 stress-free 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: 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 stress-free 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: Footwear upper according to any one of Clauses 63 to 70, wherein the central segment of the control strip has a sloping surface that slopes toward the inner periphery of the central segment between the inner arm and the outer arm.

[0354] Clause 72: Footwear uppers according to any one of Clauses 63 to 71, wherein the heel spring device is a single, integral, one-piece component.

[0355] Clause 73: Footwear uppers as described in Clause 63, wherein the heel spring assembly includes a bladder element comprising one or more fluid-filled internal cavities.

[0356] Clause 74: The footwear upper according to Clause 73, wherein: the one or more fluid-filled internal cavities comprise: a cavity extending along the central segment; and one or more reservoirs disposed at one or both of the inner arm and the outer arm and in fluid communication with the cavity extending along the central segment; and the one or more reservoirs expand as fluid transfers from the cavity extending along the central segment when the heel spring device elastically deforms under an applied force.

[0357] Clause 75: A footwear article comprising: a footwear upper including a flexible cover defining at least a portion of an ankle opening; a sole structure attached to and located beneath the footwear upper; a heel spring device including: a control bar having: a central segment attached to the flexible cover behind the ankle opening; a medial arm extending downward and forward along an inner side of the footwear upper from the central segment; and a lateral arm extending downward and forward along an outer side of the footwear upper from the central segment; and a spring operatively connected to the control bar and biasing the control bar to a stress-free position; and wherein the control bar pivots rearward to a loaded position under the action of an applied force, thereby storing potential energy in the spring, the potential energy causing the control bar to return to the stress-free position when the applied load is removed, the flexible cover moving with the control bar.

[0358] Article 76: Footwear articles according to Article 75 further include: a pin connected to both the inner arm and the outer arm and extending through the sole structure; and wherein the spring is wound around the pin, and the spring has an end fixed to pivot with a control bar and another end fixed relative to the control bar.

[0359] Article 77: A footwear article comprising: a footwear upper, the footwear upper including a flexible cover defining at least a portion of an ankle opening; a sole structure fixed to and located below the footwear upper; a heel spring device including: a rear control strip having: a central segment fixed to the flexible cover behind the ankle opening; a medial arm extending downward and forward along the medial side of the footwear upper from the central segment; and a lateral arm extending downward and forward along the lateral side of the footwear upper from the central segment; and a forefoot strip having The upper comprises: a central segment fixed to the flexible cover anterior to the ankle opening; an inner arm extending downward and backward along the inner side of the upper from the central segment; and an outer arm extending downward and backward along the outer side of the upper from the central segment; wherein the forefoot strip and the rear control strip intersect and are fixed to each other at the outer side and the inner side of the upper; and wherein the rear control strip pivots rearward to a loaded position under applied force to store potential energy, which causes the rear control strip to return to a stress-free position when the applied load is removed, and the flexible cover moves with the rear control strip.

[0360] The terms “a,” “an,” “the,” “at least one,” and “one or more” are used interchangeably to indicate the presence of at least one item. Multiple such items may be present unless the context clearly indicates otherwise. Unless explicitly and clearly indicated in the context, all numerical values ​​of parameters (e.g., quantities or conditions) in this specification (including the appended claims) should be understood to be modified in all cases by the term “about,” regardless of whether “about” actually precedes the numerical value. “About” indicates that the stated numerical value allows for some minor imprecision (somewhat close to the accuracy of the value; approximately or moderately close to the value; almost). If the imprecision provided by “about” is not otherwise understood in this ordinary sense in the art, then “about” as used herein at least indicates variations that may arise from common methods of measuring and using such parameters. Furthermore, the scope of disclosure should be understood to specifically disclose all values ​​within that scope and further subdivisions of the scope. All references cited herein are incorporated herein.

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

[0362] Those skilled in the art will recognize terms such as "above," "below," "upward," "downward," "top," and "bottom." These terms may be used descriptively with respect to the accompanying drawings and are not intended to limit the scope of the invention as defined by the claims.

[0363] While several models for implementing many aspects of this teaching have been described in detail, those skilled in the art to which this teaching pertains will recognize various alternative aspects for implementing this teaching within the scope of the appended claims. Note that everything contained in the above description or shown in the accompanying drawings should be construed as illustrative only and not restrictive.

Claims

1. A type of footwear, comprising: Footwear uppers that define at least a portion of the ankle opening; The sole structure is fixed to the upper of the footwear and located below the upper of the footwear; and Heel spring device, including: The central segment is fixed to the upper of the footwear behind the ankle opening; The inner arm extends downward and forward from the central segment; The outer arm extends downward and forward from the central segment; A base is connected to both the inner arm and the outer arm; wherein the base is fixed to the sole structure; In this configuration, the central segment is biased to an unloaded position, and the heel spring device elastically deforms to a loaded position under the force applied by the foot as the foot enters the ankle opening. The central segment is closer to the base in the loaded position than in the unloaded position, and the heel spring device stores elastic energy that causes the central segment to return to the unloaded position when the applied load is removed after the foot has fully moved into the ankle opening. The upper moves 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. When the central segment is in the loading position, the inner arm and the outer arm bend laterally outward and separately from each other, thereby widening the ankle opening.

2. A type of footwear, comprising: Footwear uppers that define at least a portion of the ankle opening; The sole structure is fixed to the upper of the footwear and located below the upper of the footwear; and Heel spring device, including: The central segment is secured to the upper behind the ankle opening; The inner arm extends downward and forward from the central segment; The outer arm extends downward and forward from the central segment; A base is connected to both the inner arm and the outer arm; wherein the base is fixed to the sole structure; In this configuration, the central segment is biased to an unloaded position, and the heel spring device elastically deforms to a loaded position under the force applied by the foot as the foot enters the ankle opening. The central segment is closer to the base in the loaded position than in the unloaded position, and the heel spring device stores elastic energy that causes the central segment to return to the unloaded position when the applied load is removed after the foot has fully moved into the ankle opening. The upper moves 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. 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; When the central segment is in the loading position, the inner arm and the outer arm bend laterally outward and separately from each other, thereby widening the ankle opening.

3. The footwear article according to claim 2, 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.

4. The footwear article according to claim 2, wherein, The extension extends at least partially from the central segment toward the base; and also includes: A stripe having a proximal end fixed to the upper and a chamber at a distal end; and The extension is disposed in the chamber, wherein the strip covers the central segment.

5. A type of footwear, comprising: Footwear uppers that define at least a portion of the ankle opening; The sole structure is fixed to the upper of the footwear and located below the upper of the footwear; and Heel spring device, including: The central segment is secured to the upper behind the ankle opening; The inner arm extends downward and forward from the central segment; The outer arm extends downward and forward from the central segment; A base is connected to both the inner arm and the outer arm; wherein the base is fixed to the outer surface of the sole structure; and In this configuration, the central segment is biased to an unloaded position, and the heel spring device elastically deforms to a loaded position under the force applied by the foot as the foot enters the ankle opening. The central segment is closer to the base in the loaded position than in the unloaded position, and the heel spring device stores elastic energy that causes the central segment to return to the unloaded position when the applied load is removed after the foot has fully moved into the ankle opening. The upper moves 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. The heel spring device is a single, integral, and single component. When the central segment is in the loading position, the inner arm and the outer arm bend laterally outward and separately from each other, thereby widening the ankle opening.

6. A type of footwear, comprising: Footwear uppers that define at least a portion of the ankle opening; The sole structure is fixed to the upper of the footwear and located below the upper of the footwear; and Heel spring device, including: The central segment is secured to the upper behind the ankle opening; The inner arm extends downward and forward from the central segment; The outer arm extends downward and forward from the central segment; A base is connected to both the inner arm and the outer arm; wherein the base is fixed to the sole structure; In this configuration, the central segment is biased to an unloaded position, and the heel spring device elastically deforms to a loaded position under the force applied by the foot as the foot enters the ankle opening. The central segment is closer to the base in the loaded position than in the unloaded position, and the heel spring device stores elastic energy that causes the central segment to return to the unloaded position when the applied load is removed after the foot has fully moved into the ankle opening. The upper moves 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. The heel spring device includes a bladder element, which includes one or more fluid-filled internal cavities; When the central segment is in the loading position, the inner arm and the outer arm bend laterally outward and separately from each other, thereby widening the ankle opening.

7. The footwear article according to claim 6, wherein: The one or more fluid-filled internal cavities include: A cavity extending along the central segment; and One or more reservoirs are disposed at one or both of the inner arm and the outer arm and are in fluid communication with a cavity extending along the central segment; and When the heel spring device elastically deforms under the applied force, the one or more reservoirs expand as fluid transfers from the cavity extending along the central segment.

8. A type of footwear upper, comprising: A flexible covering that defines at least a portion of the ankle opening; Heel spring device, including: Control bar, has: The central segment is secured to the flexible covering behind the ankle opening; The inner arm extends from the central segment and is fixed to the inside of the flexible cover; and The outer arm extends from the central segment and is secured to the outside of the flexible covering; and A continuous base that supports the control bar and is connected to both the inner arm and the outer arm; The control bar is configured to be biased to a stress-free position, at which point the central segment is a first distance from the base. During the foot entering the ankle opening, the control bar elastically deforms to a loaded position under the force applied by the foot, at which point the central segment is a second distance from the base that is smaller than the first distance. The heel spring device stores potential energy, which causes the control bar to return to the stress-free position when the foot has fully moved into the ankle opening and the applied load is removed. The flexible covering is an elastic, stretchable fabric, and also includes: A shoe collar is attached to the flexible cover, the shoe collar defining the front portion of the ankle opening; wherein the shoe collar is stiffer than the elastic stretchable fabric; A heel tab is fixed to a flexible cover; wherein the central segment of the control strip has a hole, and the heel tab extends through the hole; When the central segment is in the loading position, the inner arm and the outer arm bend laterally outward and separately from each other, thereby widening the ankle opening.

9. A heel spring device configured to surround a portion of a foot receiving cavity formed by an upper in the heel area of ​​a footwear article, the heel spring device comprising: A control bar 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 supports the control bar and connects to both the first side arm and the second side arm, the base extending along the upper at the rear of the upper; The heel spring device is combined with at least a portion of the upper that defines the ankle opening; In this configuration, the central segment is biased to an unloaded position, and the heel spring device elastically deforms to a loaded position under the force applied by the foot as the foot enters the ankle opening. The central segment is closer to the base in the loaded position than in the unloaded position, and the heel spring device stores elastic energy that causes the central segment to return to the unloaded position when the foot has fully moved into the ankle opening and the applied load is removed. The upper moves with the central segment such that the ankle opening is closer to the sole structure of the footwear article when the central segment is in the loaded position than when the central segment is in the unloaded position. When the central segment is in the loading position, the first side arm and the second side arm bend laterally outward and separately from each other, thereby widening the ankle opening.

10. The heel spring device according to claim 9, wherein, The base is connected to the first side arm at the first joint, and the base is connected to the second side arm at the second joint.

11. The heel spring device according to claim 10, wherein: The control strip has an arc shape from the first connector to the second connector; The base has an arc shape from the first connector to the second connector; and The control bar and the base are constructed as fully elliptical leaf springs.

12. The heel spring device according to claim 10, wherein: The base has a central segment, a first base arm, and a second base arm, all of which are disposed in a common plane. The first base arm and the second base arm are spaced apart and both extend from the central segment 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.

13. The heel spring device according to any one of claims 9-12, wherein the base is located below the control bar, the first side arm is located on the inner side of the upper, the second side arm is located on the outer side of the upper, and the central segment of the control bar is located behind the ankle opening.

14. The heel spring device according to any one of claims 9-12, wherein, The heel spring device is a single, integral, and individual component.

15. The heel spring device according to any one of claims 9-12, wherein the upper comprises an inner layer and an outer layer, and the control strip is disposed between the inner layer and the outer layer.

16. The heel spring device of claim 15, further comprising a shoe sole having an upper surface with a recess, wherein the heel spring device is located in the recess.

Images