This invention relates to methods of footwear construction, and in particular to methods of footwear construction that eliminate or reduce the extent of a foxing or a so-called foxing-like band.
Footwear of all types consist of two main parts: the “upper” which, in general, covers the top and sides of the foot and may cover the ankle and lower leg as well, and the “sole” which is below the upper and, in general, includes everything below the “sockline.” Footwear may also comprise one or more of the following component parts: an attached heel; linings and/or interlinings; padding (textile wadding, cellular rubber, or plastics material); a removable insole; a removable arch support; a tongue; one or more closure mechanisms such as laces, thongs, hook-and-loop straps, zippers, etc.; ornamentation such as charms, flashing lights, embroidery, appliqués, etc.; pull-on tabs or straps; protective toe-caps (steel or high impact-resistant plastic); spikes, cleats, and similar attachments designed to improve traction; insulation (textile wadding, cellular rubber, or plastics material); and other parts.
For many footwear styles including but not limited to athletic footwear, loafers, pumps, deck shoes, winter boots, work footwear, etc., the upper may consist of many parts. For example, the upper 100 of FIG. 1 illustrates an upper with various pieces such as the toe 110, the vamp 120, eyelet-stays 130, the collar 140, the heel tab 150 (also known as the “moustache”), the heel counter 160, and quarters 170. The upper component parts are commonly made of leather, plastic-coated textile material (“plastic”), compact material or cellular rubber or plastics material, or textile fabrics (woven, knit or nonwoven) in some combination.
Another footwear component is called a “permanent insole.” A permanent insole may be a flat piece of footwear structural material intended to support the foot and close an assembled upper to form a “Formed Upper.” Permanent insoles are commonly made of cellulosic material or nonwoven textile fabric that has been impregnated with a polymeric material and is often reinforced with textile fabric. An example of a commonly used permanent insole material is the family of products under the trade name TEXON®. When the various pieces of an upper are attached to each other in the proper positions, usually by sewing, adhesives or other means, and when the thus-assembled upper is attached to a permanent insole, the two assemblies form what is called a “Formed Upper.”
The sole usually comprises an insole, one or more midsoles, possibly a shank of metal or rigid plastics material, and an outsole which comes into contact with the ground. The pieces making up the sole assembly are commonly made of compact or cellular rubber or plastics material and may or may not be reinforced with textile fabric. Except as noted above, the pieces making up the sole assembly are commonly made of leather or composition leather or compact or cellular rubber or plastics material and may be reinforced or covered with textile fabric. When the various pieces of a sole are attached to each other in the proper positions, usually with adhesives but alternatively by sewing or tacking the parts together, they form what is called a “sole assembly.” Almost all footwear is constructed by securely and permanently attaching an upper to a sole assembly.
One method of footwear construction that was commonly used many years ago, especially to make athletic footwear, involved the use of a separate band or strip of material, which was almost always made of rubber, called a “foxing.” The foxing was used in the following manner: An upper was placed on top of a sole assembly and the two were securely and permanently attached to each other by covering and sealing the joint between them with a foxing. The bond between the foxing, the upper and the sole assembly was made either by means of an adhesive substance or by the process known as vulcanizing, or much less commonly, by sewing the parts together. For example, the iconic CONVERSE ALL STAR CHUCK TAYLOR™ basketball shoe was constructed by attaching an upper to a sole assembly with a foxing.
Another method of footwear construction that is commonly used today to make athletic and other types of footwear involves the use of what is called a “unit-molded outsole” as illustrated in FIG. 2a and FIG. 2b, which is a simplified cross sectional view (for example, midsoles and insoles are not shown). A unit-molded outsole 220 is a single piece of rubber or plastics material that is molded in such a way that it has (1) in the central region a concavity or depression (Outsole Base) and (2) vertically rising sidewalls 225 around the perimeter of the central concavity. The central concavity and surrounding sidewalls of the unit-molded outsole 220 are specially shaped and designed to accept an upper 230 in a snug-fitting manner. The lower parts of the upper that are in the vertical plane, are pressed against the sidewalls 225, which are also in the vertical plane, and the lowest parts of the upper that are in the horizontal plane are pressed against the top surface of the central concavity, Outsole base, which is also in the horizontal plane. The parts of the upper 230 and the unit-molded outsole 220 that are in contact with each other are then securely and permanently attached to each other, usually with an adhesive substance or by the process of vulcanization. When a shoe is constructed in this manner, the sidewall feature of the unit-molded outsole 220 serves the same purpose, and performs the same function, as a foxing; that is, the sidewall feature allows the upper 230 and the unit-molded outsole 220 to be securely and permanently attached to each other. For this reason, this sidewall feature is called a “foxing-like band.”
Both a foxing and a foxing-like band overlap an upper. A foxing, which is a separate piece of material, is applied at the sole and overlaps the upper and thereby securely and permanently joins together the upper and the sole assembly; while a foxing-like band, which is not a separate piece of material but is part of the unit-molded outsole, is molded at the sole and overlaps the upper and thereby securely and permanently joins together the upper and the sole assembly. The degree to which a foxing or foxing-like band overlaps the upper is called simply the “Overlap.”
One method by which the Overlap for a footwear sized for adults or young adults may be measured is as follows: Measuring points 250.1-250.n spaced approximately 5 millimeters (mm) apart are marked around the entire perimeter of the footwear. At each point, the amount by which the putative foxing or foxing-like band overlaps the upper at that point is measured, the measurements being taken in the vertical dimension in millimeters (mm) or in fractions of an inch. If the heights of two overlap measurements at any two adjacent points are over one-quarter inch, then the distance “D” (5 mm) between those two points, as measured in the horizontal dimension along the perimeter of the shoe, is recorded as contributing to the total Overlap. Likewise, if the overlap between two adjacent points is less than one-quarter inch, then the distance between those two points does not contribute to the total Overlap. The total Overlap is simply the sum of all the perimeter measurements between adjacent points which have an overlap greater than one-quarter inch divided by the total perimeter of the shoe. The formula for calculating the total Overlap “O” of a footwear, expressed as a percentage, is as follows:
      O    =                  (                              Σ            ⁢                                                  ⁢            D                    P                )            ·      100        ,where O is the Overlap (expressed as a percentage), ΣD is the sum of all distances or lengths of the perimeter where the vertical overlap between two adjacent points is greater than one-quarter inch, and P is the total perimeter length.
The overlap portion provides structural integrity to the shoe while keeping manufacturing costs low; however, it also increases the cost of the shoe in a way not related to the cost of materials or manufacturing. At least eighty percent of footwear sold in the United States is manufactured outside the United States and then imported into the United States for sale. All imported products, including footwear, are classified under a ten-digit code number in the Harmonized Tariff Schedule of the U.S. (HTS; Title 19 U.S.C.), and each ten-digit classification has an associated duty rate. For imported footwear, most of these duty rates are expressed in the form of a percentage of the so-called “transaction value” of the shipment. Upon importation, the shipment is classified under a ten-digit code number, and the importer must then calculate the total amount of import duty on the goods and deposit said amount with U.S. Customs & Border Protection (CBP), an agency of the United States Dept. of Homeland Security.
CBP has hundreds of rules for classifying various products. One such rule for imported footwear is the so-called “Forty-Sixty Rule.” This complicated rule states that, for footwear sized for adults and young adults, the footwear does NOT have a foxing or foxing-like band if the cumulative amount by which the sole overlaps the upper by more than one-quarter inch (on the vertical plane), which is the total Overlap “O” as derived above, is not more than 40 percent of the perimeter. Conversely, the footwear DOES have a foxing or foxing-like band if the cumulative overlap is more than 60 percent of the perimeter. Furthermore, the footwear MAY have a foxing or foxing-like band if the cumulative overlap is between 40 percent and 60 percent of the perimeter AND if the putative foxing or foxing-like band resembles the foxing on a traditional sneaker (such as the aforementioned CONVERSE ALL STAR CHUCK TAYLOR™). For footwear sized for adults and young adults, the vertical overlap is one-quarter inch; for footwear sized for boys and girls, the vertical overlap value is three-sixteenths inch, and for footwear sized for infants and toddlers, the vertical overlap value is one-eighth inch.
If the particular style of footwear is found to have a foxing or foxing-like band, the duty rate jumps dramatically in almost all cases. HTS Subheading 6402.99.3165 (6.0 percent duty) covers footwear that does not have a foxing or foxing-like band, while HTS Subheading 6402.99.4060 (37.5 percent duty) covers essentially identical footwear that does have a foxing or foxing-like band. Accordingly, a foxing or foxing like band increases the import duty on footwear of this type by more than six-fold. For this reason, most footwear importers, except those importing very high-end footwear for which price is of little concern, will try to avoid importing footwear that has a foxing or foxing-like band.
Therefore, there is a need in the art for a method of securely and permanently attaching an upper to a sole assembly such that the footwear does not have a foxing or foxing-like band as defined by the so-called “Forty-Sixty Rule.”