Patent Application
20050262728
The present invention relates to footwear and, more particularly, to a footwear construction and method for making the same.
There is an ongoing effort in the footwear industry to produce footwear that provides stability and a high level of comfort. Such footwear is targeted toward individuals who commute in urban environments, who travel on foot for significant distances on hard surfaces (e.g., concrete floors), or who require comfortable, yet stable footwear.
Conventional footwear constructions, however, provide one of stability or comfort—but usually not both—because the features required for these characteristics typically negate one another. For example, one construction known for its stability includes a heel cup positioned in the heel of the footwear. The heel cup wraps upward around the user's heel, and terminates short of the arch region. The heel cup firmly seats the user's foot in the footwear, and minimizes roll of the user's heel when the heel is properly seated in the heel cup.
Although this construction provides stability of the foot in the heel region, it fails to provide stability and torsion resistance for the remainder of the foot. Furthermore, the region where the heel cup terminates in the arch region undergoes significant stresses due to the twisting of heel cup. Accordingly, the heel cup can cause premature de-lamination or destruction of other footwear components, thereby shortening the useful life of the footwear.
At the end of the footwear spectrum, opposite heel cup constructions, are constructions built primarily for comfort, for example, casual shoe constructions. In these “comfort” constructions, a midsole and/or outsole is secured to an upper. The outsole usually is constructed from a hard wearing material. The midsole usually is constructed of a soft material such as polyurethane or ethylvinyl acetate to provide a layer of shock-absorption material. Although this construction provides comfortable cushioning for the wearer's foot, the soles wear out and the uppers detach from the soles in a short time. Moreover, the transition between the upper and the sole of such constructions typically are abrupt and aesthetically displeasing.
Although different constructions exist that provide either stability of comfort, there remains an unmet need for a footwear construction that provides the best of both requirements.
The aforementioned problems are overcome in the present invention, which provides a footwear construction including a shell with stabilizing features. The shell can include a heel cup in the heel region and a peripheral wall that extends from the heel cup, forward of the heel region, wrapping around at least a portion of the forefoot region. The shell also can define a hole in the forefoot region, optionally adjacent the peripheral wall.
In another aspect, the shell can be at least partially filled with a midsole cushioning material. Where the shell defines a hole, that material can extend into and optionally through the hole.
In a third aspect, an upper can be stitched, for example, with Opanka stitching techniques, to the shell in the forefoot region, and optionally at least partially in the arch region. The stitching can terminate short of the heel region. In a more specific aspect, the upper can include a Strobel construction in the heel region, and that Strobel construction can be secured to the midsole and/or shell, for example, with adhesives.
In another aspect, an outsole can be secured to the shell opposite the upper. The outsole can include a forefoot portion and a separate heel portion. The outsole forefoot portion can define at least one aperture. A portion of the midsole that optionally projects through the hole defined in the shell may also project into and/or through the aperture defined by the outsole.
The present invention can be manufactured by: forming a shell including a heel cup and a peripheral wall that extends forward of the heel region around at least a portion of the forefoot region; securing a cushion material within the shell; optionally Opanka stitching an upper to the shell in the forefoot region, but short of the heel region; optionally securing the upper to at least one of the shell and the cushion material in the heel region; optionally defining a hole in the forefoot portion of the shell; and optionally extending the cushion material at least partially into or through the hole.
The present invention provides a revolutionary footwear construction with an unparalleled combination of stability, comfort and styling. The shell provides both lateral and medial reinforcement for underfoot stability. Where the shell extends underfoot into the arch region, it provides an integrated arch support, as well as forefoot and rear-foot stability. Furthermore, where the shell defines a hole in the forefoot, the shell can provide both stiffness in the heel for strike stability, as well as lightness and lateral stability in at least the forefoot for easier toe-off, i.e., propulsion.
These and other objects, advantages and features of the invention will be more readily understood and appreciated by reference to the detailed description of the invention and the drawings.
A footwear construction of the present invention is shown in
In general, the shoe 10 can include an upper 20 secured to a shell 30, which can be further secured to an outsole 40. The shell 30 can include a heel cup portion 32 and a wall 34 extending around the periphery of the shoe in the forefoot region. The upper 20 can be secured to the shell with stitching 28 in the forefoot region and at least a portion of the arch region. Rearward of the stitching, the upper can be secured with cement and/or adhesives to the shell.
As used herein, the term “arch region” refers generally to the portion of the shoe corresponding to the arch of the wearer's foot; the term “forefoot region” refers generally to the portion of the shoe forward of the arch region corresponding to the forefoot (e.g., the ball and the toes) of a wearer's foot; and the term “heel region” refers generally to that portion of the shoe rearward of the arch region corresponding to the heel of the wearer's foot. The forefoot region 45, arch region 43 and heel region 49 are generally identified in
The upper 20 is generally conventional and will not be described in detail. Suffice it to say that the upper 20 can include vamp 22, quarters 24 and backstay 26. With reference to
A foot bed 25 can be positioned in the upper 20. The foot bed can be constructed from ethylvinyl acetate (EVA) foam, or any other suitable cushioning material. The rigidity and the flexibility of the EVA foam can be varied from application to application as desired. The foot bed can be secured to the closed bottom of the upper as desired as well to ensure it does not move within the upper.
The outsole 40 is manufactured from a relatively hard rubber or other sufficiently durable and wear-resistant material. This outsole can be divided into at least two separate or independent pieces. As shown, the outsole includes a forefoot portion 42, which corresponds generally to the forefoot region of the footwear, and a heel portion 44, which corresponds generally to the heel region of the footwear. These portions can be separated from one another a pre-selected distance. Each of these portions can be contoured to interfit with raised portion 39 on the bottom of the shell 30. The raised portion 39 can serve as a boundary between the forefoot and heel portions of the outsole, and can separate those elements as well. Further, the outsole portions 42 and 44 can be shaped to correspond to the recesses 35 and 37 formed on the shell 30. Accordingly, when secured to the shell, these outsole components have a flush and finished appearance.
The bottom of the outsole 40 includes an outer surface 48 that forms the wearing surface of the outsole 40 and is contoured to the desired tread pattern. The outer surface 48 can be textured to improve the traction and aesthetic appeal of the shoe. Optionally, the upper surface 47 of the outsole may be textured as desired. As shown in
With reference to
In the forefoot region 45 and/or arch region 43 of the footwear, the shell can define a hole 33. This hole 33 can be bounded by remaining portions of the base plate 31, or where the base plate is completely removed from the shell in the forefoot region, the hole can be bounded by the peripheral wall 34 itself. This hole can extend from generally from the portion of the footwear corresponding to the bottom of the ball of a wearer's foot to the toe of the footwear as desired.
In the forefoot region 45 and/or arch region 43 of the footwear, the shell can also include a ledge 34a, which projects outwardly from the wall 34 and/or the heel cup portion 32. This ledge 34a can coterminate with the stitching groove 38 as desired. The ledge can also project outwardly from the wall and/or heel cup portion a depth A from the top of those components of the shell. This depth A can be equal to the thickness of the peripheral allowance and any material secured to that allowance to close the bottom of the upper if desired. Moreover, this depth A can also correspond to and/or be equal to distance D as described below.
The exterior portions of the shell 30 can include a graphic design or text as desired. On the bottom of the shell 30, opposite the midsole 50, the shell can include at least one raised portion 39. The raised portion can be visible even when the outsole 40 and its components 42 and 44 are attached to the shell 30. The raised portion 39 can include a design (not shown) that is visible from the bottom of the shoe, even when the outsole portions 42 and 44 are secured to the shell 30. This design may also be colored or include graphic images or text as desired.
The bottom of the shell 30 can define recesses 35 and 37, which correspond to the shape of the outsole components 42 and 44, so that when these components are secured to the shell, they mount flush for a clean, finished appearance.
The shell and its components can be constructed from polyurethane, for example, thermoplastic polyurethane, or other sufficiently ridged and/or semi-ridged materials, which can be synthetic or natural.
The shell 30, including the recess defined by the heel cup portion 32 and the peripheral wall 34 in the forefoot region, can be filled with a cushion material, also referred to herein as a midsole 50. The cushion material can be poured, injected, or otherwise molded in the shell as desired. The midsole can fill the recess formed by the heel cup 32 and the peripheral wall 34 to a depth that enables the wall 34 to be exposed above the uppermost portion of the midsole 50. Optionally, the cushioning material 50 may be formed within the shell so that in at least the forefoot region 45 a distance D (
The midsole can define an air cushion recess 52 in the heel region 49 to receive an air cushion 54. The midsole can also include a midsole heel wall 58, which extends partially up the shell heel wall 36. On the underside of the midsole 50, protrusions 56 can be formed. These protrusions can extend at least partially through the hole 33, and as desired, into or at least partially through the holes 46 defined by the outsole. These protrusions 56 can be colored as desired.
Optionally, a shank (not shown) of steel, plastic, nylon or other material may be secured or molded in the cushioning material that forms the midsole 50 in the arch region 43 of the shoe. The shank can extend and/or overlap with other regions of the footwear, for example the forefoot region 45 and the heel region 49.
Manufacture of the shoe 10 will now be described with reference to
In another step, the shell 30 is formed. Material from which the shell is made can be injected into a mold shaped to correspond to the features of the shell, for example, the heel 32, the peripheral wall 34, the base plate 31, the stitching groove 38 and/or the raised portion 39 on the underside of the shell. The mold can be contoured so that the hole 33 is formed in the shell as it is formed. However, the shell can also be formed without the hole, and the hole 33 trimmed from the shell after it is formed. Further, the exposed portion of the shell may be printed with a graphic design via any conventional printing methods, for example, oil printing, lithograph and/or airbrush. The shell 30 can be trimmed as desired. Other techniques can be used to form the shell as desired.
With the shell formed, the cushion material 50 can be secured to the shell. The material 50 can be pour molded into the cavity formed by the heel cup and the peripheral wall. When the material fills this cavity, it can also at least partially extend within or through the hole 33 of the shell. Optionally, a secondary mold (not shown) can be positioned adjacent the bottom of the shell so that protrusions 56 are formed in the cushion material that is exposed through the hole 33. These protrusions can be contoured and shaped so that they align with corresponding holes 46 in the outsole. Further, the cushion material 50 can be filled in the shell to a specific depth so that a portion of the peripheral wall 34 is exposed a distance D, and optionally, the ledge 34a is exposed as well, as shown in
It is noted that the portion of the shell wall 34 that is exposed above the cushion material can be a completely separate component from the cushioning material 50 that forms the midsole. In this configuration the two components, i.e., the wall 34 in the midsole 50 are separate and independent components.
As the midsole 50 is formed, features, such as the air cushion hole 52 and stitching guide holes, can also be formed in the upper surface of the cushioning material 50.
The outsole components 42 and 44 can be injection molded or pour molded from a hard, durable rubber using conventional molding apparatus. The tread pattern 48 on the lower surface of the outsole, as well as the holes 46 defined in the forward portion 42 of the outsole can be formed during the molding operation. Optionally these features, as well as any contours or shapes of the outsole components, can be cut through the outsole 40 after it is molded. It is noted that the holes 46 can be cut so that they align with the protrusions 56 of the midsole. The outsole and its components can be secured to the shell with cement, adhesives or other attachment devices.
The outsole components 42 and 44 also can be aligned with the raised portion 39, and within respective shell recesses 35 and 37, and then secured to the shell 30. When included, the protrusions 56 of the midsole also can be aligned with the holes 46 in this securing process. The outsole components may be trimmed as desired to ensure a flush and clean fit with the shell 30.
In another step, the shell 30 with the cushion material 50 secured therein is attached to the upper. This can be accomplished by stitching the peripheral allowance 23 to the shell wall 34 in the forefoot regions 45 and optionally the arch region 43. The stitching can be accomplished via machine or hand stitching. More specifically, the peripheral allowance can be Opanka stitched to the shell and/or midsole in the forefoot region 45. The stitching can be protected from abrasion by the passing through the shell within the groove 34, through the peripheral allowance 23, back through the peripheral allowance 23 and then back through the shell 30 repeatedly. In the heel 49 and/or arch regions 43 of the shoe, the upper can be secured with glue to the upper surface of the cushioning material 50, and over the air cushion 54 when included. The upper optionally can be further glued to the heel flanges 58 of the midsole and the heel wall 36 of the shell.
With the outsole 40 secured to the upper 20, the foot bed 25 can be positioned in the interior of the upper 20. A number of conventional finishing operations can be performed on the shoe 10. For example the edges of the shell 30 and outsole 40 can be trimmed and shaped; the upper 20 can be cleaned, polished and treated as appropriate and necessary; and where applicable, laces can be inserted into eyelids.
The above descriptions are those of the preferred embodiments of the invention. Various alterations and changes can be made without departing from the spirit and broader aspects of the invention as defined in the appended claims, which are to be interpreted in accordance with the principles of patent law including the doctrine of equivalents. Any references to claim elements in the singular, for example, using the articles “a,” “an,” “the,” or “the,” is not to be construed as limiting the element to the singular.
