Patent Publication Number: US-6662469-B2

Title: Footwear construction and method for manufacturing same

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to footwear, and more particularly to the construction of an article of footwear and the method for manufacturing footwear in accordance with this construction. 
     There is an ongoing effort to develop footwear constructions that provide improved comfort at a reduced cost while providing aesthetic appeal. In one conventional construction, a shoe is provided with an upper material that wraps entirely around the foot and a sole that is affixed to the material on the bottom of the shoe in two distinct portions, one located in the heel region and one in the forefoot region. The upper material therefore visibly wraps beneath the shoe in the arch region, providing a unique aesthetic appeal. A leather insole is secured in the upper to integrate the forefoot and heel portions and to provide the sole with a certain level of rigidity and support. This prior art construction is illustrated in FIGS. 1-3. The prior art shoe  200  includes a wrap-around upper  202  and a two-piece sole  204 . The sole  204  includes a heel portion  222  and a forefoot portion  224  that are spaced apart in the arch region to expose the wrap-around upper  202 . As shown, the upper  202  includes various pieces of leather that are stitched together to form an envelope that encloses the entire foot. The upper  202  includes a vamp piece  208  that wraps over the forefoot region and is stitched together along a seam  210  extending longitudinally along the approximate center of the bottom the shoe. The upper  202  also includes one or two pieces of material  212  that wrap around the heel region. The heel piece(s)  212  are stitched to the vamp piece  208  along an angled, but near to vertical, seam  214 . If two heel pieces are included in the construction, they may be stitched to one another along a seam (not shown) extending longitudinally along the approximate center of the bottom shoe (where it is hidden by the heel portion  222  of the sole  204 ) and then up along the rear of the shoe (where it is hidden by the backstay  216 ). The upper  202  also includes an eyestay  218  stitched around the tongue opening  220 . A leather insole  226  is fitted within the shoe. 
     Although providing a desirable aesthetic appearance, this conventional construction suffers from a number of drawbacks. First, this construction requires a large vamp piece that extends entirely around the shoe. The vamp piece must be large enough to extend from one side the bottom center of the shoe, around the top of the shoe and back down to the other side of the bottom center of the shoe. This can dramatically increase material costs, particularly when the upper is formed from high-grade leather. Second, the shoe includes a heel piece that is joined to the vamp piece along a substantially vertically extending stitch. At the same time, the vamp piece wraps entirely around the arch and forefoot regions seamed only along the bottom center of the shoe. Accordingly, the shape of the upper in the arch and forefoot regions is largely created by deforming the vamp piece on the last. This may lead to an undesirable amount of stretching of the leather, which can buckle, bulge or otherwise misshape the material. Third, the leather insole does not provide the level of support and stability desirable for certain activities. 
     SUMMARY OF THE INVENTION 
     The aforementioned problems are overcome by the present invention wherein a footwear construction with a “wrap-around” upper and separate heel and forefoot sole portions is provided with an upper and a bottom that are joined along a substantially horizontal seam. The horizontal seam is preferably disposed slightly above the sole and is preferably shaped to extend substantially parallel to the bottom line of the foot. 
     In a preferred embodiment, the horizontal seam includes an outwardly-turned moc stitch in the forefoot and heel regions, and an inwardly turned butt stitch in the arch region. The upper and bottom are preferably cemented along the stitching margin in the forefoot and heel regions to enhance the attachment and resist delamination of the stitched components. 
     In a more preferred embodiment, the sole includes separate forefoot and heel portions and a molded insole that is fitted within the upper atop the bottom bridging the forefoot and heel portions of the sole. The molded insole preferably extends through the heel and arch regions terminating in the forefoot region in approximately alignment with the ball of the foot. This provides the heel and arch regions with the desired level of stability while permitting the forefoot to bend and flex as desired. 
     The present invention also provides a method for manufacturing an article of footwear. The method generally includes the steps of (1) forming the various pieces of the upper, (2) stitching the upper pieces to define a horizontally extending margin, (3) attaching a shank to a bottom leather piece, (4) stitching the bottom leather piece to the upper along the horizontal seam, (5) lasting the upper and bottom leather assembly, (6) setting the shape of the upper and bottom leather assembly, (7) forming the outsole from separate forefoot and heel portions, and (8) installing a molded insole and a footbed in the upper. The horizontal stitch is preferably formed with a moc stitch in the forefoot and heel regions and an interior stitch in the arch region. 
     The present invention provides an article of footwear that provides a desired aesthetic appeal while enhancing comfort and reducing the costs associated with the manufacture of conventional constructions of similar design. The horizontal seam permits the upper to be manufactured from smaller pieces of material, which can significantly reduce material costs, particularly when the upper is formed of leather. The horizontal seam further permits the upper to more closely follow the shape of the foot with reduced stretching of the upper on the last. This is further enhanced by a curved horizontal seam the follows the bottom line of the foot. The use of an outsole with separate forefoot and heel regions reduces the necessary amount of outsole materials. The molded insole permits the forefoot region of the shoe to flex as desired while also providing the arch and heel regions with support and stability. 
     These and other objects, advantages, and features of the invention will be readily understood and appreciated by reference to the detailed description of the preferred embodiment and the drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a top plan view of a prior art construction; 
     FIG. 2 is a side elevational view of the prior art construction; 
     FIG. 3 is a bottom plan view of the prior art construction; 
     FIG. 4A is a right side elevational view of a shoe constructed in accordance with a preferred embodiment of the present invention; 
     FIG. 4B is a left side elevational view of the shoe; 
     FIG. 5 is a top plan view of the shoe; 
     FIG. 6 is a bottom plan view of the shoe; 
     FIG. 7A is a sectional view of a portion of the shoe taken along line  7 A— 7 A of FIG. 5; 
     FIG. 7B is a sectional view of a portion of the shoe taken along line  7 B— 7 B of FIG. 5; 
     FIG. 7C is a sectional view of a portion of the shoe taken along line  7 C— 7 C of FIG. 5; 
     FIG. 7D is a sectional view of a portion of the shoe taken along line  7 D— 7 D of FIG. 5; 
     FIGS. 8A-E are plan views of the various upper pieces; and 
     FIGS. 9A-B are plan views of the bottom pieces. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     A shoe manufactured in accordance with a preferred embodiment of the present invention is shown in FIG.  4  and generally designated  10 . The shoe  10  includes an upper  12 , a bottom  14  and an outsole  16 . As shown in FIG. 7, the shoe  10  also includes an insole  20  and a footbed  22  that are fitted within the upper  12 . The upper  12  and bottom  14  are stitched together along a substantially horizontal seam  18 . The outsole  16  includes separate forefoot and heel portions,  24  and  26 , respectively. Although the present invention is described in connection with an aftersport shoe, the present invention is well-suited for use with other conventional categories of footwear. In this application, the term “arch region” refers generally to that portion of the shoe corresponding to the arch of the wearer&#39;s foot, the term “forefoot region” refers generally to the portion of the shoe forward of the arch region corresponding the forefoot (e.g. ball and toes) of the wearer&#39;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&#39;s foot. The forefoot region  30 , arch region  32  and heel region  34  are identified in FIG.  4 . 
     As described above, the upper  12  and the bottom  14  cooperatively define the foot-containing envelope of the shoe  10 . Although the precise design and layout of the upper  12  will vary from application to applications, the upper  12  preferably includes inner quarter  100  (See FIG.  8 B), outer quarter  102  (See FIG.  8 A), eyestay  104  (See FIG.  8 C), backstay  106  (See FIG. 8D) and tongue  108  (See FIG.  8 E). The upper  12  includes a marginal allowance  36  extending around its periphery for securing the upper  12  to the bottom  14  as described in more detail below. The margin  36  varies in width between the forefoot  30 , arch  32  and heel  34  regions to provide sufficient material for stitching the upper  12  to the bottom  14 . As shown, the margin  36  in the forefoot and heel regions is wide enough to accommodate an outwardly turned moc stitch. The margin  36  in the arch region is significantly narrower, providing just enough material for an inwardly turned butt stitch. 
     The bottom  14  preferably includes inner piece  112  (See FIG. 9A) and outer piece  114  (See FIG.  9 B). The two pieces  112  and  114  extend longitudinally along inner and outer sides of the shoe  10  and are joined together along a longitudinal seam extending substantially along the center of the bottom  14 . The bottom  14  includes a marginal portion  38  extending around its periphery for securing the bottom  14  to the upper  12 . Referring now to FIG. 4, the bottom margin  38 , like the upper margin  36 , varies in width between the forefoot, arch and heel regions. The margin  38  in the forefoot and heel regions is wide enough to accommodate an outwardly turned moc stitch while the margin  38  in the arch region is narrower, providing just enough material for an inwardly turned butt stitch. 
     An insole  20  is cemented within the upper  12  to the top surface of the bottom  14 . The insole  20  preferably extends only three-quarters of the length of the shoe  10  terminating in the forefoot region  30  in approximate alignment with the ball of the foot. The thickness of the insole  20  preferably tapers-off toward its forward edge. The insole  20  is preferably shaped to match the contour of the undersurface of a foot, providing a substantially rigid platform to support the arch and heel regions of the foot. Although the rigidity of the insole  20  can vary from application to application, the preferred insole  20  is sufficiently rigid to prevent flexing of the shoe  10  in the heel and arch regions under normal loads. As a result, the insole  20  eliminates the need for a conventional shank. The insole  20  is preferably manufactured from conventional materials, such as nylon or other polymeric materials. 
     A footbed  22  is removably fitted within the upper  12  atop the insole  20 . The footbed  22  preferably extends the full length of the shoe  10  and is of a dual-density construction having upper  40  and lower  42  layers. The upper layer  40  is preferably manufactured from a cushioning material having a relatively low density. As a result, the upper layer  40  provides resiliency and cushioning under relatively small load, such as during sitting, standing or gentle movements. The lower layer  42  is preferably manufactured from a relatively high density material, providing resiliency and cushioning under heavier loads, such as during walking, running or jumping. A conventional sock liner (not shown) preferably covers the upper surface of the footbed  22 . 
     As noted above, the outsole  16  includes a forefoot portion  24  and a heel portion  26 . The two outsole portions,  24  and  26 , are spaced apart from one another in the arch region. This makes the bottom  14  visible in the arch region providing a desirable aesthetic appeal. FIGS. 7A-7D are cross-sectional views showing the construction at various locations along the shoe  10 . The forefoot portion  24  preferably extends through the forefoot region  30  of the shoe  10 , providing a wear surface that engages the ground beneath the forefoot of the wearer&#39;s foot. The bottom surface of the forefoot portion  24  is preferably textured to provide improved traction. If desired, the forefoot portion  24  can include tread, lugs or other traction improving elements. The upper surface of the forefoot portion  24  is preferably shaped to correspond with the desired shape of the insole  20  and footbed  22 . The heel portion  26  preferably extends through the heel region  34  of the shoe  10 , providing a wear surface that engages the ground beneath the heel of the wearer&#39;s foot. The bottom surface of the heel portion  26  is preferably textured to provide improved traction. Like the forefoot portion  24 , the heel portion  26  can include treads, lugs or other traction improving elements, as desired. The upper surface of the heel portion  26  is preferably shaped to correspond with the desired shape of the insole  20  and footbed  22 . The forefoot portion  24  and heel portion  26  are preferably molded separately and secured to the bottom  14  by cement or other conventional adhesives. Alternatively, the forefoot portion  24  and heel portion  26  can be molded in place on the bottom using conventional direct attach molding techniques and apparatus. 
     MANUFACTURE AND ASSEMBLY 
     The shoe  10  is manufactured using conventional manufacturing equipment. The various pieces of the upper  12  are cut from the desired material, such as leather, using conventional techniques and apparatus. As described above, the upper  12  is preferably assembled from inner quarter  100 , outer quarter  102 , eyestay  104 , backstay  106  and tongue  108  as shown in FIGS. 8A-E. The upper pieces are stitched together in a conventional manner to form the upper  12 . For example, the inner quarter  100  is stitched to the outer quarter  102  in the toe region at seam  124  and in the heel region at a second seam (not shown). This second seam (not shown) is covered by backstay  106 . It should be noted that the upper pieces are cut to define a margin  36  that functions as a stitching allowance extending around the periphery of the assembled upper  12 . This margin  36  is cooperatively defined by the inner quarter  100 , outer quarter  102  and backstay  106 . The upper pieces are configured such that the margin  36  follows a substantially horizontal line (and more preferably a line that substantially follows the bottom line of a foot) when the upper  12  and bottom  14  are stitched together. Holes  62  may be preformed in the margin  36  in the inner quarter  100 , outer quarter  102  and backstay  106  to facilitate the moc stitch  52  in those regions. The bottom pieces, namely inner piece  112  and outer piece  114 , are also cut from the desired material using conventional techniques and apparatus (See FIGS.  9 A-B). The bottom pieces are preferably cut from the same material as the upper pieces to provide the desired “wrap-around” appearance. The bottom pieces are cut to define a horizontal seam and to provide sufficient material to form margin  38 . The bottom pieces are stitched together in a conventional manner to form the bottom  14 . The seam  50  between the bottom pieces preferably extends longitudinally along the bottom center of the shoe  10 . Holes  64  may be preformed in the margin  38  in the inner bottom piece  112  and the outer tom piece  114  to facilitate the moc stitch in those regions. The upper  12  and bottom  14  are preferably lined and reinforced with a conventional lining material (not shown), a conventional toe box (not shown) and other conventional reinforcing pieces (not shown) as desired. 
     The insole  20  is manufactured from a substantially rigid material, preferably from nylon or other polymeric material. As such, the insole  20  is preferably injection molded or die cast from a molten material, or vacuum formed from a sheet stock. The insole  20  may be manufactured using other conventional techniques and apparatus corresponding to the selected insole material. The manufacture insole  20  is adhered to the upper surface of the bottom  14  using conventional cements or other adhesives. 
     The upper  12  and bottom  14  are then stitched together using conventional apparatus. As noted above, the seam extends in a generally horizontal direction, and more preferably along a generally horizontally extending curve that runs parallel to the bottom line of the foot. Accordingly, the terms “generally horizontal” and “substantially horizontal” are intended to be sufficiently broad to encompass a line extending substantially parallel to the bottom line of a foot. As illustrated, the seam curves slightly upwardly as its extends from the back of the shoe toward the arch region. In the arch region, the seam in more dramatically curved, substantially following the curve of an arch of a foot. It should be noted that the seam preferably follows a higher arch on the medial side of the shoe than on the lateral side, much like the arch of a foot. The seam returns to a slight curve in the heel region. The curved seam facilitates shaping of the upper to match the shape of the foot. The upper  12  and bottom  14  are joined in the forefoot  30  and heel  34  regions by an outwardly turned moc stitch  52  (or cable stitch) that extends along margins  36  and  38 . The moc stitch  52  may be hand or machine sewn as desired, preferably using a conventional moc-stitch thread. Before stitching the outwardly turned region, a layer of cement is applied between the two margins  36  and  38 . The cement reduces the likelihood of separation, or delamination, of the two margins  36  and  38  in the outwardly turned region. The upper  12  and bottom  14  are joined in the arch region  32  using a conventional inwardly turned butt stitch  54 . The butt stitch  54  may be machine or hand sewn as desired. 
     The upper  12  and bottom  14  assembly are then fitted over a conventional punch last (not shown). Although the shape of the shoe is primarily defined by the cut of the upper  12  and bottom  14  pieces, the punch last helps to set the shape the shoe  10 . The upper  12  and bottom  14  assembly is preferably heat set to hold its shape. 
     The footbed  22  is a generally conventional dual-density footbed, having coextensive upper  56  and lower  58  layers of differing densities. The footbed  22  is manufactured using conventional techniques and apparatus, preferably from EVA, foamed polyurethane or other similar cushioning materials. A lining material (not shown) may cover the top surface of the footbed  22 . The footbed  22  is preferably removably inserted into the shoe  10 , but can be “permanently” secured if desired. 
     The above description is that of a preferred embodiment 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 reference to claim elements in the singular, for example, using the articles “a,” “an,” “the” or “said,” is not to be construed as limiting the element to the singular.