Patent Application
20120260535
“Traction” is a general term that describes the ability of a shoe outsole to resist sliding motion over a surface contacted by that outsole. Traction is particularly important for footwear used in sports and other activities in which a shoe wearer wishes to move quickly and/or to rapidly change movement directions relative to a potentially slippery surface. For an athlete, secure, non-sliding contact between that athlete's footwear and a playing surface can be important for preventing injury and for improving the athlete's performance.
It is known to include cleats or other traction-enhancing outsole extensions on footwear intended for use in sports and/or other activities. During running or other actions, these extensions can penetrate a ground surface and help stabilize an athlete's foot from unwanted movement. Unfortunately, a single configuration for traction extensions an athletic shoe may not be optimal over a range of conditions in which that shoe will be used. For example, some surfaces can have extremely variable conditions. If a playing surface is softer and/or more slippery, a larger number of extensions can be useful. When the ground is harder or less slippery, however, fewer extensions may be needed. An athlete may also need more traction during some specific movements (e.g., while running) and less traction during other actions (e.g., while standing).
Although useful to increase traction, outsole extensions can also be sources of discomfort. In particular, a protruding traction element can generate a point pressure on a shoe wearer's foot. An outsole extension that might be useful under some conditions (e.g., when running) may be a source of irritation under other conditions (e.g., when standing). Finding the correct balance between traction enhancement and comfort for footwear thus remains an ongoing challenge.
This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key or essential features of the invention.
In at least some embodiments, an outsole element can include a first side and an exposed second side opposite the first side. The first side can be bonded or otherwise attached to a midsole or other shoe component when a shoe is assembled. The outsole element may further include a plurality of recesses formed in the second side. Each of those recesses may include a concave region that is aligned with a corresponding raised region on the first side. Each recess may further include a corresponding traction element extending outward from the interior of the concave region. In response to force induced by a wearer of a shoe including the outsole element, raised regions of the outsole element may be deformed and the traction elements extended.
Some embodiments are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings and in which like reference numerals refer to similar elements.
Shoe 1 includes a sole structure 2. Sole structure 2 includes an outsole 3 and a midsole 4. These and other components of sole structure 2 are further described below. Although not shown in
Shoe 1 also includes an upper 5. Upper 5 can be placed on a last and bonded to midsole 4 when shoe 1 is assembled. Shoes having sole structures according to various embodiments can include various types of uppers. Because the details of such uppers are not pertinent to understanding sole structures disclosed herein, upper 5 is shown generically in
When referring to an outsole or other component of a sole structure, a “forefoot” region will generally lie under or near the metatarsal and phalangeal bones of a shoe wearer's foot and may extend beyond the wearer's toes to the frontmost portion of the shoe. A forefoot region may extend beyond the medial or lateral peripheral edge of the wearer's foot. A “midfoot” region will generally lie under or near the cuboid, navicular, medial cuneiform, intermediate cuneiform and lateral cuneiform bones of the wearer's foot. A midfoot region may also extend beyond the medial or lateral peripheral edge of the wearer's foot. A “hindfoot” region of a sole structure extends from the midfoot region and under/near the wearer calcaneus (heel bone), may extend to the rearmost portion of the shoe, and may also extend beyond the medial or lateral peripheral edge of the wearer's foot. One or more of the above-described regions may overlap, and description of a component by reference to a particular anatomical structure does not require that the component cover that entire anatomical structure. For example, and as discussed in further detail below, outsole 3 does not completely cover the bottom side of midsole 4, and thus would not contain portions lying under all portions of all of a wearer's foot bones.
In the embodiment of shoe 1, outsole 3 comprises a front outsole element 11, a middle outsole element 12, and a rear outsole element 13. In other embodiments, an outsole may be a single element or may consist of two, four or other numbers of separate elements. Outsole 3 could be molded as a single unit. Elements 11, 12 and 13 could then separated and bonded to midsole 4 (e.g., with adhesive) during assembly of shoe 1. Front element 11 is located in a forefoot region of sole structure 2 and covers the frontmost portion of the bottom of midsole 4. In the embodiment of shoe 1, front element also includes a toe cap 14 that wraps around the frontmost portion of midsole 4 and of upper 5. Rear edge 15 of outsole element 11 may be approximately located on a line that passes under the first and second distal phalanges.
Middle element 12 is also located in the forefoot region of sole structure 2. Element 12 covers the bottom portion of midsole 4 corresponding to the distal ends of the first through fifth metatarsals, to the first through fifth proximal phalanges, to the second through fifth intermediate phalanges, and to the third through fifth distal phalanges. Front edge 16 of element 12 may approximately correspond to front portions of the first and second distal phalanges.
Rear element 13 includes portions in the forefoot, midfoot and hindfoot regions of sole structure 2. A front portion 17 of element 13 generally corresponds to the fifth metatarsal. Element 13 then continues around the outer edges of midsole in the mid- and hindfoot regions. Portions of element 13 correspond approximately to locations of a wearer's cuboid, calcaneus, navicular, medial cuneiform and intermediate cuneiform bones.
In the embodiment of shoe 1, the interior region 20 of rear element 13 is open and exposes a bottom side 21 of midsole 4. The exposed portion of midsole 4 bottom side 21 within opening 20 is recessed relative to element 13. In other embodiments, rear element 13 may have a different configuration of open region(s) or may lack an open region altogether.
Each of elements 11, 12 and 13 has a shape that generally corresponds to the outer edges of a corresponding portion of sole structure 2. For example, the medial and lateral edges of forward element 11 are generally aligned with side edges of midsole 4 in the region where element 11 is attached. As previously indicated, toe cap 14 wraps around the frontmost portion of midsole 4. Lateral edges of middle element 12 are generally aligned with lateral edges of midsole 4 in the region where middle element 12 is attached. Medial edges of element 12 are generally aligned with medial edges of midsole 4 in the same region. The outer edge of rear element 13 is generally aligned with the outer edge of midsole 4 in the region where rear element 13 is attached, although a small rearmost heel portion 47 (see
In some embodiments, an outsole may include one or more flexure zones to increase flexibility of a sole structure. In the embodiment of shoe 1, middle element 12 of outsole 3 includes grooves 22, 23 and 24. Lateral side slots 25, 26 and 27 formed in the lateral edge of element 12 act as lateral side extensions of grooves 22, 23 and 24. Medial side slots 28, 29 and 30 formed in the medial edge of element 12 similarly act as medial side extensions of grooves 22, 23 and 24. Another flexure zone is created by the space between rear edge 15 of front element 11 and front edge 16 of middle element 12. Rear element 13 may also include flex grooves 34-39.
A tread pattern 41 is formed on the exposed bottom side 42 of rear outsole element 13, on the exposed bottom side 43 of middle element 12, and on the exposed bottom side 44 of front element 11. For convenience, tread pattern 42 is shown as a simple herringbone pattern. Other tread patterns (or combinations of tread patterns) could alternatively be used. For example, a tread pattern could comprise chevron shapes of alternating orientations and that create a discontinuous herringbone pattern.
In the embodiment of shoe 1, each of recesses 49a through 49l has a concave shape of a dome interior. Each of recesses 49a through 49l has a rim (50a through 50l) that is at roughly the same level as the peaks of the surrounding regions of tread pattern 41. In other embodiments, some or all of the rims 50a through 50l may be absent or may have a different height. Similarly, outsoles according to some embodiments may have extendable traction elements located within recesses having different shapes.
Once shoe 1 is assembled, top sides 54, 55 and 56 would not be exposed, as each would be bonded to a portion of the bottom side 21 of midsole 4.
As seen in
Returning to
In the embodiment of shoe 1, midsole 4 is formed by injection molding two types of compressed ethylene vinyl acetate (EVA) foam (also known as Phylon). In particular, most of midsole 4 is formed from a first type of EVA foam, but an insert 64 is formed from a second type of EVA foam. The material used for insert 64 can be less dense than the material of the remainder of midsole 4 so as to be slightly softer and increase wearer comfort. In some embodiments, foam material for an insert similar to insert 64 could be denser (and firmer) than foam material used for other portions of a midsole. In still other embodiments, an entire midsole may be formed from a single type of foam having a generally uniform density.
The location of insert 64 approximately corresponds to the center of the forefoot region. In some embodiments, that location roughly corresponds to the location of the second and third proximal phalanges and to the second and third proximal-phalangeal joints. In other embodiments, an insert similar to insert 64 could be larger and extend over a larger portion of the midsole. In yet other embodiments, a midsole may include more than two types of material.
The concave spaces within each of recesses 49c through 49f is aligned with the corresponding one of raised regions 60c through 60f and contains the corresponding one of traction elements 48c through 48f. Each of traction elements 48c through 48f is generally frustoconical in shape. Each has a proximal end (65c through 65f) centered in the base of its corresponding recess. For example, traction element 48f has a proximal end 65f centered in the base of recess 49f. Each of traction elements 48c through 48f further includes a distal end (66c through 66f). In the unloaded condition of
In some embodiments, traction elements 48k and/or 48l, together with their corresponding structures (recesses 49k and 49l, rims 50k and 50l, raised regions 60k and 60l, midsole depressions 61k and 61l) could be omitted or placed in alternate locations. Indeed, one or more of the other traction elements 48a-48j and their corresponding structures could be omitted or be placed in an alternate location in some embodiments. Similarly, additional traction elements and corresponding structures could be included.
Although
Outsole 3 can be formed from rubber or from other types of elastomeric materials. In the embodiment of shoe 1, outsole 3 is formed from a single type of synthetic rubber. In certain embodiments, more than one type of rubber might be used.
Portions 170 and 171 are indicated in
In the embodiments described thus far, the extendable traction elements were integrally molded as part of the outsole elements, with the corresponding outsole recesses and raised regions also formed at the time of molding. This need not be the case, however. In some embodiments, for example, outsole recesses and raised regions could be formed when the outsole is molded. The extendable traction elements could then be separately formed and attached to the outsole within the recesses. Such attachment could be permanent (e.g., by adhesive bonding) or by way of a mechanical fastener (e.g., a threaded connection).
The foregoing description of embodiments has been presented for purposes of illustration and description. The foregoing description is not intended to be exhaustive or to limit embodiments to the precise form explicitly described or mentioned herein. Modifications and variations are possible in light of the above teachings or may be acquired from practice of various embodiments. The embodiments discussed herein were chosen and described in order to explain the principles and the nature of various embodiments and their practical application to enable one skilled in the art to make and use these and other embodiments with various modifications as are suited to the particular use contemplated. Any and all permutations of features from above-described embodiments are the within the scope of the invention. References in the claims to characteristics of a physical element relative to a wearer of claimed article, or relative to an activity performable while the claimed article is worn, do not require actual wearing of the article or performance of the referenced activity in order to satisfy the claim.
