(12) United States Patent
`Dua
`
`I 1111111111111111 11111 111111111111111 IIIII IIIII IIIII IIIII IIIIII IIII 11111111
`US0069317 62B 1
`
`(10) Patent No.:
`(45) Date of Patent:
`
`US 6,931,762 Bl
`Aug. 23, 2005
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`(54) FOOTWEAR WITH KNIT UPPER AND
`METHOD OF MANUFACTURING THE
`FOOTWEAR
`
`(75)
`
`Inventor: Bhupesh Dua, Portland, OR (US)
`
`(73) Assignee: Nike, Inc., Beaverton, OR (US)
`
`( *) Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 157 days.
`
`(21) Appl. No.: 10/323,608
`
`(22) Filed:
`
`Dec. 18, 2002
`
`Int. Cl.7 ................................................ A43B 23/00
`(51)
`(52) U.S. Cl. ........................... 36/9 R; 36/45; 12/146 C;
`12/142 G; 66/185
`(58) Field of Search ................. 36/95 R, 45; 12/146 C,
`12/142 G; 66/185, 186, 187, 188
`
`(56)
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`1,597,934 A *
`1,902,780 A *
`2,147,197 A *
`2,400,692 A *
`2,586,045 A *
`2,603,891 A *
`2,675,631 A *
`4,211,806 A
`4,216,662 A *
`4,255,949 A
`4,317,292 A *
`4,373,361 A
`4,447,967 A
`4,607,439 A
`4,785,558 A
`4,813,158 A
`6,308,438 Bl
`
`Stimpson . ... .. ... ... ... ... .. . 36/3 A
`Holden et al. ................ 66/186
`Glidden ... ... .. ... ... ... ... .. . 36/9 R
`Herbert ... .. ... ... ... ... ... .. ... 36/10
`Hoza ........................... 36/9 R
`Cohn .......................... 36/9 R
`Doughty .. ... .. ... ... ... ... .. . 36/9 R
`Civardi et al.
`Harris et al. .................. 66/186
`Thorneburg
`Melton . ... ... .. ... ... ... ... .. . 36/9 R
`Thorneburg
`Zaino
`Sogabe et al.
`Shiiomura
`Brown
`Throneburg et al. .......... 36/9 R
`
`8/1926
`3/1933
`2/1939
`5/1946
`2/1952
`7/1952
`4/1954
`7/1980
`8/1980
`3/1981
`3/1982
`2/1983
`5/1984
`8/1986
`11/1988
`3/1989
`* 10/2001
`
`OTHER PUBLICATIONS
`
`"Knitting Dictionary" by Charles Reichman, Jun. 23, 1967,
`p. 97.*
`Internet publication entitled "Acorn Footwear-Slipper
`Sock," from Northland Marine, which shows products that
`were on sale in this country at least one year prior to the
`filing date of the present application, 1 page.
`Internet publication entitled "Welcome
`to Arcopedico
`Shoe," from Arcopedico Shoes, which shows products that
`were on sale in this country at least one year prior to the
`filing date of the present application, 4 pages.
`Leaflet entitled "X machine," from Sangiacomo S.p.A,
`which was on sale in this country at least one year prior to
`the filing date of the present application, 1 page.
`Advertising material entitled "Still Crazy After All These
`Years," which shows a product entitled "Sock Racer" and
`was sold in this country in 1986 by NIKE, Inc., 3 pages.
`
`* cited by examiner
`
`Primary Examiner-Ted Kavanaugh
`(74) Attorney, Agent, or Firm-Banner & Witcoff, Ltd.
`
`(57)
`
`ABSTRACT
`
`An article of footwear with a knit upper and a method of
`manufacturing the footwear are disclosed. The upper is
`formed through a knitting process to include a plurality of
`sections formed of different yarns and knits to provide the
`sections with different physical properties. In portions of the
`upper where sections formed of different yarns are in adja(cid:173)
`cent wales, a tuck stitch is utilized to join the sections. The
`method utilizes a circular knitting machine having multiple
`feeds that work together to knit the upper into a unitary,
`seamless structure. The multiple feeds, each of which pro(cid:173)
`vide multiple types of yarns, produce the sections to have
`varying physical properties.
`
`30 Claims, 3 Drawing Sheets
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`10
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`Figure 1
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`U.S. Patent
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`Aug. 23, 2005
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`Figure 3
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`Figure 4
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`US 6,931,762 Bl
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`1
`FOOTWEAR WITH KNIT UPPER AND
`METHOD OF MANUFACTURING THE
`FOOTWEAR
`
`2
`is knitted to have a sock-like structure in which areas
`subjected to greater wear and in which a lower degree of
`elasticity is desired are more densely fabricated to provide
`heavier weight and less extensibility than in other portions.
`5 This may be accomplished, for example, by changing the
`type of stitch. Other areas, such as the ankle portion, may be
`formed to have a ribbed construction to provide softness and
`elasticity.
`
`15
`
`BACKGROUND OF THE INVENTION
`1. Field of the Invention
`The present invention relates to footwear and the manu(cid:173)
`facture of footwear. The invention concerns, more
`particularly, a footwear upper formed through a textile 10
`manufacturing process to have areas with different physical
`properties.
`2. Description of Background Art
`Conventional articles of athletic footwear generally
`include two primary elements, an upper and a sole structure.
`The upper is attached to the sole structure and forms a void
`on the interior of the footwear for securely and comfortably
`receiving a foot. The sole structure attenuates ground reac(cid:173)
`tion forces and absorbs energy as the footwear contacts the
`ground, and often incorporates multiple layers that are
`conventionally referred to as a midsole and an outsole. The
`midsole forms the middle layer of the sole and serves a
`variety of purposes that include controlling potentially
`harmful foot motions, such as over pronation; shielding the
`foot from excessive ground reaction forces; and beneficially
`utilizing such ground reaction forces for more efficient
`toe-off. The outsole forms the ground-contacting element of
`footwear and is usually fashioned from a durable, wear
`resistant material that includes texturing to improve traction.
`The sole structure may also include an insole, which is a
`thin, cushioning member located within the upper and
`adjacent to a sole of the foot to enhance footwear comfort.
`The upper of most conventional articles of footwear is
`generally formed from multiple material elements that are 35
`stitched and adhesively bonded together to form a comfort(cid:173)
`able structure for receiving the foot. Conventional athletic
`footwear may include, for example, an exterior formed of
`leather and polymer textile materials that are resistant to
`abrasion and provide the footwear with a particular aes- 40
`thetic. Foam materials may be located on the interior of the
`upper to enhance the comfort of the upper, and mois(cid:173)
`turewicking textiles may be positioned adjacent the foot to
`limit the perspiration within the upper.
`In a departure from the conventional upper described 45
`above, NIKE, Inc. of Beaverton, Oregon, United States
`manufactures athletic footwear with a knit upper under the
`PRESTO trademark. The knit upper includes a plurality of
`material elements that are formed through a knitting process.
`In manufacturing the upper, the material elements are cut 50
`from a larger element and sewn together along their respec(cid:173)
`tive edges to form a generally hollow structure for receiving
`a foot. The upper, therefore, includes a plurality of
`separately-formed, knit sections stitched together to form
`seams between the various sections.
`Based upon the discussion above, the uppers for athletic
`footwear are generally constructed of numerous materials or
`elements. In manufacturing the uppers, considerable time
`and labor is expended in cutting the various elements to have
`a proper shape and size, and stitching or adhesively bonding 60
`the elements to each other. Consequently, these footwear
`manufacturing techniques are not only time and labor
`intensive, but also result in an undesirable amount of waste
`materials resulting from the trimming of the materials to
`make the elements.
`A unitary upper formed through a knitting process is
`disclosed in U.S. Pat. No. 2,147,197 to Glidden. The upper
`
`20
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`25
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`30
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`SUMMARY OF THE INVENTION
`The present invention is an article of footwear having a
`sole structure and an upper. The sole structure provides a
`ground-contacting surface, and the upper is structured to
`receive a foot of a wearer. The upper is attached to the sole
`structure and has a first section and a second section formed
`of knit materials. The first section is formed of a first yarn
`with a first physical property, and the second section is
`formed of a second yarn with a second physical property.
`The first physical property is different than the second
`physical property. The first and second sections are con(cid:173)
`nected by tuck stitches that join the first section and the
`second section in a seamless manner.
`Other methods of joining the first section and the second
`section may form tails, or ends of yarns, that are exposed and
`may cause the area between the first and second sections to
`unravel. By utilizing a tuck stitch, however, tails are not
`formed and the first and second sections are joined seam(cid:173)
`lessly.
`A method of manufacturing an upper that is similar to the
`upper described above may be performed through three
`general steps. First, a first section of the upper is knitted
`from a first yarn having a first physical property. Second, a
`second section of the upper is knitted from a second yarn
`having a second physical property, with the first physical
`property being different than the second physical property.
`Furthermore, tuck stitches are knitted between the first
`section and the second section to join said first section with
`the second section. In order to perform the steps described
`above, a narrow-tube circular knitting machine may be
`utilized.
`The advantages and features of novelty characterizing the
`present invention are pointed out with particularity in the
`appended claims. To gain an improved understanding of the
`advantages and features of novelty, however, reference may
`be made to the following descriptive matter and accompa(cid:173)
`nying drawings that describe and illustrate various embodi(cid:173)
`ments and concepts related to the invention.
`
`DESCRIPTION OF THE DRAWINGS
`The foregoing Summary of the Invention, as well as the
`following Detailed Description of the Invention, will be
`better understood when read in conjunction with the accom(cid:173)
`panying drawings.
`FIG. 1 is an exploded perspective view of an article of
`55 footwear that incorporates an upper in accordance with the
`present invention.
`FIG. 2 is a bottom plan view of the upper.
`FIG. 3 is a perspective view of another upper in accor(cid:173)
`dance with the present invention.
`FIG. 4 is a perspective view of a narrow-tube circular
`knitting machine that may be utilized in manufacturing
`uppers in accordance with the present invention.
`
`65
`
`DETAILED DESCRIPTION OF THE
`INVENTION
`The following discussion and accompanying figures dis(cid:173)
`close an article of footwear 10 and a method of manufac-
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`US 6,931,762 Bl
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`3
`turing footwear 10 in accordance with the present invention.
`Footwear 10 includes an upper that is formed as a unitary,
`knit structure with various sections having different physical
`properties. The various sections are joined in a generally
`seamless manner and may exhibit different degrees of
`strength, abrasion-resistance, stretch, support, stiffness,
`recovery, fit, and form, for example. In joining the various
`sections, tuck stitches are utilized to seamlessly-connect
`sections between wales.
`An exploded view of footwear 10 is depicted in FIG. 1
`and includes a sole structure 20 and an upper 30 that is
`attached to sole structure 20 through adhesive bonding or
`stitching, for example. Sole structure 20 provides a durable,
`ground-contacting surface and attenuates ground reaction
`forces and absorbs energy as footwear 10 contacts the
`ground. The primary elements of sole structure 20 are an
`insole 21, a midsole 22, and an outsole 23. Insole 21 is a thin,
`cushioning member located within upper 30 and adjacent to
`a sole of the foot to enhance footwear comfort. Midsole 22
`forms the middle layer of sole structure 20 and may be
`structured to serve a variety of purposes that include con(cid:173)
`trolling potentially harmful foot motions, such as over
`pronation; shielding the foot from excessive ground reaction
`forces; and beneficially utilizing such ground reaction forces
`for more efficient toe-off. Outsole 23 forms the ground(cid:173)
`contacting element of footwear 10 and may be fashioned
`from a durable, wear resistant material that includes textur(cid:173)
`ing to improve traction. Suitable materials for midsole 22
`include ethylvinylacetate and polyurethane foam, and may
`include additional components such as a fluid-filled bladder.
`Outsole 23 may be formed from carbon black rubber
`compound, for example.
`Sole structure 20 also includes a toe support 24, a heel
`support 25, and a securing system 26. Toe support 24
`extends upward from a fore portion of midsole 22 and is
`configured to extend around fore portions of the toes to limit
`forward movement of the foot. Similarly, heel support 25
`extends upward from a rear portion of midsole 22 and is
`configured to extend around the heel to limit rearward
`movement of the foot. A portion of heel support 25 also 40
`extends along the medial and lateral sides of the foot to limit
`side-to-side movement of the foot. Securing system 26
`includes a pair of straps 27a and 27b that extend over the
`instep of the foot and operate to secure the foot within upper
`30 and relative to sole structure 20.
`The configuration of sole structure 20 discussed above
`provides an example of a suitable sole structure for the
`present invention. In alternate embodiments, toe support 24
`and heel support 25 may extend over a greater area of the
`foot, for example. Securing system 26 may also include a
`plurality of straps that extend around the heel, over the
`instep, and over the toes. Accordingly, the specific configu(cid:173)
`ration of sole structure 20 may vary significantly within the
`scope of the present invention.
`Upper 30 is formed primarily from multiple yarns that are
`mechanically manipulated through an interlooping process
`to produce a unitary structure having various sections with
`different physical properties. Various interlooping tech(cid:173)
`niques are available for mechanically manipulating yam into 60
`upper 30. In general, however, interlooping involves the
`formation of a plurality of rows and columns of intermeshed
`loops, which are conventionally referred to as courses and
`wales. Knitting is generally recognized as being the most
`common method of interlooping.
`The configuration of upper 30 is selected to generally
`conform to the shape of the foot. The knitting process that
`
`4
`produces upper 30 forms a plurality of sections, each section
`being specifically located, knit in a specific manner, and knit
`with a specific type of yarn to provide each section with
`different physical properties. The sections in the exemplary
`5 embodiment of FIGS. 1 and 2 include an ankle section 31,
`a heel section 32, an instep section 33, a primary section 34,
`and a toe section 35. Ankle section 31 is configured to
`surround the ankle and form an ankle opening that provides
`access to the interior of upper 30. Heel section 32 is
`10 positioned adjacent to ankle section 31 and is configured to
`extend around a portion of the heel. Instep section 33
`extends along the instep from ankle section 31. Primary
`section 34 extends along medial and lateral sides of the foot,
`over the toes, and along the sole of the foot. Finally, toe
`15 section 35 extends around the portion of upper 30 that
`corresponds with the ends of the toes.
`The yarn and knit selected for ankle section 31 provides
`four-way stretch around the ankle opening. That is, ankle
`section 31 expands vertically and horizontally upon the
`20 application of a tensile force, thereby permitting the foot to
`enter upper 30. Once the foot is within upper 30, ankle
`section 31 contracts to recover the unstretched shape and
`comfortably conform to the shape of the ankle. Ankle
`section 31 includes an inner layer and an overlapping outer
`25 layer that are formed as a jersey knit by reversing the textile
`to create the two, overlapping layers. The inner layer of
`ankle section 31 is formed to include a slit 36. A semi-rigid
`element may be inserted through slit 36 to form a support
`positioned between the inner layer and the outer layer of
`30 ankle section 31. In order to provide the stretch and recovery
`properties of ankle section 31, a yarn that incorporates an
`elastane fiber may be utilized. Elastane fibers are available
`from E.I. duPont de Nemours Company under the LYCRA
`trademark. Such fibers may have the configuration of cov-
`35 ered LYCRA, wherein the fiber includes a LYCRA core that
`is surrounded by a nylon sheath. Other fibers or filaments
`exhibiting elastic properties may also be utilized in ankle
`section 31.
`Heel section 32 is formed to provide two-way stretch in
`the horizontal direction, but limit stretch in the vertical
`direction. In forming heel section 32, a ribbed texture is
`imparted due to inherent material shrinkage when removed
`from a cylinder of a narrow-tube circular knitting machine,
`which will be described in greater detail below. Heel section
`32 stretches, therefore, along various ribs 37, which are
`oriented horizontally. The specific materials forming heel
`section 32 may include a combination of 400 denier and 800
`denier nylon yarns. This combination permits the horizontal
`stretch, but limits stretch in the vertical direction. If, for
`50 example, four-way stretch is desired, yarn incorporating
`elastane fibers may be substituted. In addition, lesser stretch
`or no stretch may be achieved by increasing the course
`density and denier of the yam in heel section 32. Depending
`upon the desired characteristics of heel section 32, therefore,
`55 yarns with a variety of fibers or filaments may be utilized, as
`discussed in detail below.
`Yarn is defined as an assembly having a substantial length
`and relatively small cross-section that is formed of at least
`one filament or a plurality of fibers. Fibers have a relatively
`short length and require spinning or twisting processes to
`produce a yarn of suitable length for use in an interlooping
`process. Common examples of fibers are cotton and wool.
`Filaments, however, have an indefinite length and may
`merely be combined with other filaments to produce a yarn
`65 suitable for use in an interlooping process. Modem filaments
`include a plurality of synthetic materials such as rayon,
`nylon, polyester, and acrylic, with silk being the primary,
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`naturally-occurring exception. Yarn may be formed of a
`single filament (conventionally referred to as a monofila(cid:173)
`ment yarn) or a plurality of individual filaments. Yam may
`also be formed of separate filaments formed of different
`materials, or the yarn may be formed of filaments that are
`each formed of two or more different materials. Similar
`concepts also apply to yarns formed from fibers.
`Accordingly, yarns may have a variety of configurations
`within the scope of the present invention that generally
`conform to the definition provided above.
`As discussed above, nylon yarns or yarns that incorporate
`elastane fibers are suitable for heel section 32. The charac(cid:173)
`teristics of the various yarns selected for heel section 32
`depend primarily upon the materials that form the various
`filaments and fibers. Cotton, for example, provides a soft
`hand, natural aesthetics, and biodegradability. Elastane
`fibers, as discussed above, provide substantial stretch and
`recoverability. Rayon provides high luster and moisture
`absorption. Wool also provides high moisture absorption, in
`addition to insulating properties. Polytetrafluoroethylene
`coatings may provide a low friction contact between the
`textile and the skin, thereby limiting the formation of
`blisters. Nylon is a durable and abrasion-resistant material
`with high strength. Finally, polyester is a hydrophobic
`material that also provides relatively high durability.
`Accordingly, the materials comprising the yarn may be
`selected to impart a variety of physical properties to heel
`section 32 or any other section of upper 30. The physical
`properties may include, for example, strength, stretch,
`support, stiffness, recovery, fit, and form.
`Instep section 33 extends along the instep from ankle
`section 31 and provides four-way stretch. Although the knit
`may be similar to ankle section 31, instep section 33 will
`generally be formed to have a single layer, rather than the
`overlapping layers of ankle section 31. The same yam
`utilized for ankle section 31 may be utilized for instep
`section 33. In addition, a plurality of openings 38 may be
`formed in instep section 33 to enhance the stretch properties
`of instep section 33. Instep section 33 may be formed by
`using three feeds of yams, for example. When switching
`between the feeds, a tuck stitch is generally utilized. By not
`forming a tuck stitch in specific locations, openings 37 are
`formed.
`Primary section 34 forms a majority of upper 30 and is
`positioned to extend along medial and lateral sides of the
`foot, over the toes, and along the sole of the foot. As with
`heel section 32, primary section 34 includes a plurality of
`ribs 37. In general, ribs 37 are oriented to permit upper 30
`to stretch around the foot, and to limit longitudinal stretch 50
`along the foot. Heel section 32 and primary section 34 may
`be formed through the same knitting process, but ribs 37 in
`each of heel section 32 and primary section 34 are oriented
`in different directions. The rationale for permitting stretch
`around the foot in primary section 34 is that upper 30 will
`conform to feet with various width dimensions. The degree
`of stretch in primary section 34 may be adjusted by utilizing
`a yarn with greater denier and increasing the course density.
`Toe section 35 extends around the portion of upper 30 that
`corresponds with the ends of the toes, and toe section 35
`includes a plurality of ribs 37 that are oriented horizontally.
`In this orientation, stretch is provided in the horizontal
`direction. Any of the materials discussed above with respect
`to heel section 32 may be utilized for primary section 34 and
`toe section 35.
`A narrow-tube circular knitting machine may be utilized
`to manufacture upper 30. An example of a circular knitting
`
`6
`machine that may be utilized to form upper 30 will be
`discussed in greater detail below. In general, circular knit(cid:173)
`ting machines form a tube-like structure. Upper 30,
`therefore, also has a tube-like structure with openings at
`5 opposite ends of the tube. The ankle opening in ankle section
`31 forms a first opening, and an aperture 39 in the lower
`surface of primary section 34 forms a second opening.
`Aperture 39 is analogous to the seam that extends over the
`toes in a conventional sock that is also manufactured on a
`circular knitting machine. Insole 21, which is positioned
`10 within upper 30, may be utilized to cover aperture 39.
`Based upon the above discussion, upper 30 has a knit
`structure with various sections 3135 that impart different
`physical properties. Ankle section 31 is formed of a yam and
`knit that provides four-way stretch. Heel section 32 is
`formed of a different yarn and a different knit to provide
`two-way stretch and durability, for example. Instep section
`33 also provides four-way stretch, but includes only a single
`layer of knit material. Similar considerations are also appli(cid:173)
`cable to primary section 34 and toe section 35. Accordingly,
`the different sections 31-35 of upper 30 impart physical
`properties that are specially selected for the each section
`31-35. More specifically, the knitting process that produces
`upper 30 forms a plurality of sections 31-35 that are
`specifically located, knit in a specific manner, and knit with
`a specific type of yam to provide each section 31-35 with
`different physical properties. The physical properties may
`include, for example, strength, stretch, support, stiffness,
`recovery, fit, and form.
`In manufacturing upper 30 with a circular knitting
`machine, various types of yam and various knit structures
`are utilized to form the various sections 31-35. As discussed
`above, upper 30 is manufactured to have the general shape
`of a tube. The circular knitting machine, therefore, operates
`35 to form a first course, which corresponds with an end of the
`tube. A second course is then knit adjacent to the first course,
`and the process continues through successive courses until
`upper 30 is complete.
`The manner in which the circular knitting machine
`40 changes between different yarn types and knit structures
`depends upon whether the change occurs between adjacent
`courses or between adjacent wales. A course is a horizontal
`row of needle loops. In general, a circular knitting machine
`may knit a first course with a first yarn and then knit a second
`45 course with a second yarn without altering the structure of
`the knit material. That is, two courses that are formed of two
`different types of yam will have a structure that is substan(cid:173)
`tially identical to two courses formed of the same yam,
`except for the differences imparted by the different yarns.
`Whereas a course is a horizontal row of needle loops, a
`wale is a vertical column of intermeshed needle loops. A
`course, therefore, includes a plurality of wales. In forming
`two wales from the same yarn, a circular knitting machine
`merely makes successive knits along the course. To form
`55 two wales from different yarns, however, a circular knitting
`machine forms a tuck stitch between the wales of different
`yarns. That is, a tuck stitch is utilized to seamlessly connect
`two wales formed of different yarns. In forming upper 30,
`therefore, tuck stitches are often utilized to seamlessly join
`60 the various sections 31-35 between two adjacent wales. An
`advantage to utilizing the tuck stitches, rather than some
`other methods of joining the sections, is that the ends of
`yarns, otherwise referred to as tails, are not exposed, thereby
`decreasing the possibility of unraveling between the sec-
`65 tions.
`Referring specifically to upper 30, tuck stitches 11 are
`utilized between instep section 33 and primary section 34 to
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`US 6,931,762 Bl
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`join sections 33 and 34 together. No tuck stitches 11 are
`necessary between ankle section 31 and instep section 33,
`for example, because ankle section 31 and instep section 33
`are joined between courses, rather than wales. Accordingly,
`tuck stitches 11 are utilized in any portion ofupper 30 to join 5
`wales formed of two different yarns.
`Upper 30 is intended to provide one example of a suitable
`upper for footwear 10 or other articles of footwear that
`include a knit structure for the upper. Other uppers may be
`formed to have a variety of other configurations. That is, the
`various sections of other uppers may be positioned, knit
`from specific yarns, and formed with a specific knit structure
`to achieve a desired purpose. For example, an upper 40,
`which is also suitable for footwear 10, is depicted in FIG. 3.
`Upper 40 includes an ankle section 41, a heel section 42, an
`instep section 43, a primary section 44, and a metatarsal
`section 45.
`Ankle section 41 is configured to surround the ankle and
`form an ankle opening that provides access to the interior of
`upper 40. Heel section 42 is configured to extend around a
`portion of the heel. Instep section 43 extends along the
`instep from ankle section 41, and extends around the ankle
`to thereby separate ankle section 41 from heel section 42.
`Primary section 44 extends along medial and lateral sides of
`the foot, over the toes, and along the sole of the foot. Finally,
`metatarsal section 45 is located within instep section 43 and
`generally covers a forward portion of the foot. Upper 40 may
`also include a section that is similar in location and structure
`to toe section 35 of upper 30.
`Upper 40 is formed primarily from multiple yarns that are
`mechanically manipulated through an interlooping process
`to produce a unitary structure having various sections 41-45
`with different physical properties. The physical properties
`may include, for example, strength, stretch, support,
`stiffness, recovery, fit, and form. The various yarns may be
`selected to include any of the yarns discussed above with
`respect to upper 30. In addition, tuck stitches 12 are utilized
`in any portion of upper 40 to seamlessly join wales formed
`of two different yarns .
`A method of manufacturing upper 40 will now be dis(cid:173)
`cussed with reference to an exemplary embodiment of a
`narrow-tube circular knitting machine 50, which is depicted
`in FIG. 4. One skilled in the relevant art will appreciate that
`the concepts disclosed in the following discussion also apply
`to the manufacture of upper 30 or any other upper in
`accordance with the present invention. Knitting machine 50
`is similar to conventional circular sock knitting machines,
`which knit in a circular fashion to create tubular structures,
`such as socks. The conventional circular knitting machines
`typically form the socks, for example, from two separate
`feeds of yarn with each feed including up to ten different
`types of yarns. Using the conventional knitting machine,
`multiple steps and operations are required to knit the sock.
`For example, the conventional sock is knit using a continu(cid:173)
`ous forward motion of the knitting machine cylinder to first
`knit the rib and leg portions of the sock. The cylinder then
`switches into a fixed reciprocating motion to knit the heel
`pocket of the sock. The cylinder returns to the continuous
`forward motion to knit the foot portion of the sock. Finally, 60
`the cylinder switches back into the fixed reciprocating
`motion to knit the toe pocket of the sock.
`Unlike conventional two feed circular knitting machines,
`knitting machine 50 has four feeds of yarn, with each feed
`containing up to ten different types of yarns in fingers. An 65
`example of a suitable, commercially available narrow-tube
`circular knitting machine that may be utilized as knitting
`
`8
`machine 50 is sold by Sangiacomo S.p.A. of Italy under the
`X-MACHINE trademark. The X-MACHINE has been used
`to produce argyle-style socks where multiple colored yarns
`form argyle and other complex patterns.
`Knitting machine 50 is depicted in FIG. 4 and includes
`first, second, third, and fourth feed valve assemblies
`5la-5ld, respectively. Each assembly 5la-5ld is associated
`with a feed finger assembly, a feed center cam, and a forward
`and reverse stitch cam. Only the first and second feed finger
`10 assemblies 52a and 52b, the second feed cam 53b, and the
`first and second forward and reverse stitch cam 54, however,
`are depicted in FIG. 4. A 160 needle, 4 inch cylinder
`assembly 55 is centrally located. Finally an elastic power
`feeder 56, a dial head assembly 57, and a dial and circular
`15 cutter 58 are positioned above cylinder assembly 55.
`Extending downward from spools are a plurality of yarns 59.
`In manufacturing upper 40 with knitting machine 50, a
`plurality of tuck stitches 12 are utilized to join wales formed
`of two different yams. Accordingly, tuck stitches 12 are
`20 present between instep section 43 and primary portion 44,
`for example. Tuck stitches are also utilized between side
`portions of metatarsal section 45 and instep section 43. No
`tuck stitches 12 are necessary, however, to join courses
`formed of different yarns. Accordingly, no tuck stitches are
`25 present between ankle section 41 and instep section 43, for
`example. Numerous yarn materials of varying diameters,
`sizes, stretch characteristics and colors, thus, can be used to
`manufacture upper 40.
`Knitting machine 50 has the ability to run in a continuous
`30 or in a reciprocating motion, and can select groups or
`patterns of needles in either the knit, tuck or float position.
`Utilizing the four yarn feeds of the machine, different yarn
`types can be used and different patterns and textures can be
`formed within sections 41-45, and the various sections
`35 41-45 may be linked together by the use of tuck stitches,
`where necessary to join wales of different yarns.
`Advantageousl