Patent Application
20090044425
There are a wide variety of methods to manufacture footwear. Such methods generally involve some manner of attaching an upper and an outsole. A common approach to manufacturing footwear is the utilization of cemented construction. With a cemented footwear construction, the upper is lasted over an insole with the outsole then cemented thereto. Although this construction is relatively durable, resulting footwear is quite heavy and the process generates considerable waste. Therefore, a more simplified method of manufacture would be desirable in which more lightweight footwear can be manufactured.
In general, the present disclosure is directed improved footwear and related methods of manufacturing the same.
In one embodiment of the present disclosure, a method of manufacture of footwear is provided. The method includes providing an upper that defines a lower perimeter. An outsole is provided that defines a lip extending along the upper perimeter of the outsole. A thread is stitched through the lower perimeter of the upper and at least a portion of the lip of the outsole whereby a foot receiving space is defined between the upper and the outsole. A last is inserted into the foot receiving space defined by the upper and the outsole to set the shape of the upper.
In still another embodiment, an article of footwear is provided which includes an upper defining a lower perimeter. An outsole is provided having a lip extending along the upper perimeter of the outsole. The upper is attached to the outsole by thread along the lower perimeter of the upper and at least a portion of the lip of the outsole whereby a foot receiving space is defined between the upper and the outsole.
Other features and aspects of the present disclosure are discussed in greater detail below.
A full and enabling disclosure of the present disclosure, including the best mode thereof to one of ordinary skill in the art, is set forth more particularly in the specification, including reference to the accompanying Figures in which:
Repeat use of reference characters in the present specification and drawings is intended to represent the same or analogous features or elements of the present disclosure.
It is to be understood by one of ordinary skill in the art that the present discussion is a description of exemplary embodiments only, and is not intended as limiting the broader aspects of the present disclosure, which broader aspects are embodied in the exemplary construction.
Generally, the present disclosure is described in connection with a casual shoe. A footwear construction of the present disclosure is illustrated in
Referring to
One purpose for lip 34 is to receive stitching 22, as shown in
Outsole 30 can be manufactured from ethylene vinyl acetate (EVA) or relatively hard rubber or other sufficiently durable and wear-resistant material. In certain embodiments, outsole 30 can have a Shore A hardness from about 45 to about 90. In some embodiments, outsole 30 can have a Shore A hardness from about 50 to about 80. In some embodiments, outsole 30 can have a Shore A hardness from about 55 to about 75. Top surface 40 of outsole 30 forms a foot receiving surface and is contoured to suit a wearer's foot, either with or without an optional footbed. The bottom surface 39 can be textured to improve the traction and aesthetic appeal of the shoe.
With reference to
Upper 20 is constructed such that lower perimeter 21 can be stitched into lip 34 of outsole 30. In some embodiments, as in
Any suitable thread can be used for stitching. In some embodiments, nylon thread can be utilized. One or more stitch lines can be utilized to secure an upper 20 to lip 34 of outsole 30. In some embodiments, lower perimeter 21 of an upper 20 can be thinner than the remainder of the upper. In certain embodiments, reinforcement taping can be present on lower perimeter 21 of an upper 20 and lip 34. Such reinforcement taping can aid in the securement of lower perimeter 21 and upper 20.
Upper 20 and outsole 30 define a foot receiving space when stitched together. In certain embodiments, the weight of each shoe 10 is from about 0.1 lbs to about 0.5 lbs. For example, in certain embodiments in which the shoes do not have a footbed present, the weight of each shoe 10 can be from about 0.2 lbs to about 0.4 lbs and, in certain embodiments, from about 0.25 lbs to about 0.35 lbs. The footwear of the present disclosure weigh less than similar shoes constructed using other methods.
A liner (not shown) can be secured to the inner portion of an upper 20 so as to contact a wearer's foot. This liner can optionally extend the full length and/or width of an upper 20 or some portion thereof. Liner can be formed from acrylic, fleece, cotton, mesh, nylon, CAMBRELLE®, twill, canvas, polyester, wool, flannel, terry cloth, soy, bamboo, hemp, cotton, flax, cellulose, leather, foam, sherling, combinations thereof, or any other material as would be known in the art.
A foot bed can be optionally utilized in accordance with the present disclosure. The foot bed can be constructed from 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 outsole 30 as desired to ensure it does not move within the upper. In embodiments which include a footbed, the weight of each shoe can be from about 0.25 lbs to about 0.45 lbs and, in certain embodiments, from about 0.3 lbs to about 0.4 lbs. With the optional footbed, the weight of the shoe 10 is still less than shoes manufactured by conventional methods.
Manufacture of the shoe 10 will now be described. Upper 20 is manufactured using generally conventional techniques and apparatus. The desired upper material is cut to form the upper, including its elements, such as the vamp. Pieces of an upper can be fitted and sewn together if necessary or a unitary piece of material can be utilized to form an upper. In some embodiments, a center seam is preferred when the upper is stitched together. In other embodiments, a butt seam, inseam with whipstitch, zigzag stitch, or the like can be utilized. In addition, material can be perforated, overlayed, underlayed, laser cut, or the like.
Outsole components can be injection molded or pour molded from a suitable material as described herein using conventional molding apparatus. The tread pattern on bottom surface 39 of the outsole, as well as lip 34 extending upwardly from side surface 36 about the perimeter 38 of outsole 30 can be formed during the molding operation. Optionally these features, as well as any contours or shapes of the outsole components, can be molded into outsole 30. The outsole components may be trimmed as desired to ensure fit with an upper 20.
Upper 12 and outsole 30 may be stitched together using conventional apparatus. As noted above, one or more stitching threads 28 runs through the lower perimeter of the upper 21 and at least a portion of lip 34 of the outsole 30 so as to define a opening 46 between an upper 20 and outsole 30. A machined lock stitch is preferred but any stitch as would be known in the art can be utilized such as a hand stitch or the like so long as the stitching adequately secures the upper to the outsole. In certain embodiments, nylon reinforcement tape can be affixed to the lower perimeter of the upper. Suitable methods of affixing include heat sealing or cementing the tape to the lower perimeter of the upper.
A last is inserted in the opening between an upper and outsole. As is known in the art, lasting involves tightly shaping the upper over the contour of a last, a piece of wood or synthetic material roughly following the shape of the foot and acting as a form on which the shoe is made. The upper is heated with a last inserted so as to form the desired shape and/or desired size. In some embodiments, it is important to heat the upper and last to between about 60° C. and about 70° C. for between about 15 minutes and about 20 minutes. In this regard, temperature can be important because hotter temperatures can result in the upper to shrink. In certain embodiments, an upper can be heated by steam. The last is removed and the shoe is allowed to cool. Additionally, the upper can be wet shrunk on the last as would be known to one of ordinary skill in the art
In some embodiments, a footbed can be inserted within the opening between an upper 21 and the outsole 30.
Finishing steps can include spraying the footwear with any desired treatment such as a mold prevention treatment, water proofing treatment, or the like.
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.
These and other modifications and variations to the present invention may be practiced by those of ordinary skill in the art, without departing from the spirit and scope of the present invention, which is more particularly set forth in the appended claims. In addition, it should be understood that aspects of the various embodiments may be interchanged both in whole or in part. Furthermore, those of ordinary skill in the art will appreciate that the foregoing description is by way of example only, and is not intended to limit the invention so further described in such appended claims.
