The present disclosure relates to a footwear article that includes circular knit structures and a method of making such footwear articles.
Conventional footwear articles have a sole and an upper attached to the sole. Footwear manufacturing has historically been a cut-sew-assembly operation that is labor intensive. Panels of upper materials are cut to size and sewn together to create the upper. The sole is attached to the upper using a number of different techniques to create the finished footwear article. Recent developments in footwear design employ knitting technology to form portions of footwear and the upper in particular. In some instances, flat bed knitting is used to form a planar knitted fabric blank. The planar knitted fabric blank is formed into a specific shape so that it can be folded or wrapped into a near completed shoe upper. Once the upper is formed, the sole component or other durable structures are attached to the knitted shoe upper consistent with conventional footwear manufacturing techniques. While some sewing is required to create the shoe upper using flat-bed knitting, fewer sewing steps are required compared to conventional shoe manufacturing. Although flat knitting may result in increased material utilization, because fabric cutting in minimized, there are design limits and production inefficiencies inherent in flat knitting.
An embodiment of the present disclosure is a footwear article, knitted blank, and a method for making a footwear article and a knitted blank. The footwear article includes a double layer knitted upper having a foot bed, an upper portion continuous with the foot bed, an ankle opening, and an inner void for receiving a foot of a wearer. The double layer knitted upper has an outer knit layer defining an exterior surface of the double layer knitted upper. The double layer knitted upper also has an inner knit layer monolithically knit to the outer knit layer. The inner knit layer has a plurality of inner knit regions that spatially correspond to the plurality of outer knit regions of the outer knit layer. The outer knit layer and the inner knit layer substantially define the foot bed and the upper portion of the double layer knitted upper.
Embodiments of the present disclosure include a footwear article that includes a circular knitted fabric formed into a double-layer knitted upper of a footwear article 10. The footwear article 10 is disclosed as having a configuration suitable for walking or running. Concepts associated with the footwear may also be applied to a variety of other athletic footwear types, including baseball shoes, basketball shoes, cross-training shoes, cycling shoes, football shoes, tennis shoes, soccer shoes, sprinting shoes, and hiking boots, for example. The concepts may also be applied to footwear types that are generally considered to be non-athletic, including dress shoes, loafers, sandals, and work boots. The concepts disclosed in this application apply to a wide variety of footwear types.
Referring to
Continuing with
The footwear article 10 includes a plurality of tabs 22a-22d that extend upwardly from the sole component 20 along a medial side 14 and a lateral side 15 of the footwear article 10. The plurality of tabs 22a-22d include securing members 24a-24d in the form of openings, slots, and/or hooks that receive a cord 18.
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Referring to
The double layer knitter upper include at least one attachment member that consolidates the outer knit layer 60 to the inner knit layer 80, thereby forming the double layer knitted upper. The attachment member may be any material that fuses the outer knit layer 60 and the inner knit layer 80 together. Because the outer and inner knit layers are circular knit structure, each layer has float yarns on side due to the different knit constructions formed in the knitted regions described below. When the double layer knitter upper is formed the floats from the outer knit layer 60 face the floats from the inner knit layer 80. The floats can create snags and deform the knit construction when the floats are pulled or the layers or otherwise deformed. The attachment members address this problem by consolidating the outer knit layer and the inner knit layer together. In particular, the attachment member bonds the yarns from the outer knit layer 60 to the yarns from the inner knit layer 80. This bonding minimizes distortion in the knit structure created in use. The attachment members also bind the outer and inner knit layers together so that the two layers do not slide relative to one another. The attachment member provides stability to the double layer knitted upper. In one example, the attachment member may comprise binding yarns. The binding yarns may comprise part of the knit stitches, may be laid-in, or plated in during knitting. When the binding yarns exposed to a desired temperature (at above glass transition temperature), the binding yarns melt, thereby consolidating the outer and inner knit layers 60, 80 together. The binding yarns may be thermoplastic polyurethane yarns. In another example, the binding yarns are low-melt thermoplastic yarns that have a lower melt temperature than the yarns used to form the outer and inner knit layers 60, 80. In an alternative embodiment, the attachment member may be a low-melt adhesive film, a low melt adhesive nonwoven web, or an adhesive coating. In still another alternative embodiment, the attachment member could be binding yarns that tack the outer layer and inner layer together.
The outer knit layer 60 has plurality of outer knit regions 62a-62f and the inner knit layer 80 has a plurality of inner knit regions 82a-82g. The outer and inner knit regions comprise selected textile structural elements. The selected textile structural elements may include specific knit stitches and/or presence of certain yarns. Furthermore, the selected textile structural elements may include the absence of certain knit stitches and/or yarns. One or more of the plurality of outer knit regions 62a-62f of the outer knit layer 60 may spatially correspond to one or more of the plurality of inner knit regions 82a-82g. In embodiments where the inner knit regions spatially correspond to the outer knit regions, the inner knit regions completely or partially underlie the outer knit regions. For example, each one of the inner knit regions 82a-82e underlie the respective outer knit regions 62a-62d. However, the outer knit layer 60 and the inner knit layer 80 may comprise different knit regions in different locations from the other.
As best shown in
The double layer knitted upper can have a variety of circular knit constructions. For instance, the double layer knitted upper may have include a single jersey knit construction, a double knit construction, rib knit construction, a terry knit construction, or other types of weft knit constructions. Furthermore, the different regions of the double layer knitted upper may comprise different knit stitches, such as float stitches, held stitches, missed stitches, and other knit stitches known to a person of skill in the art. In one example, the outer knit toe regions 62a, 82a of the outer and/or inner layer may comprise a cushioned knit construction. Likewise, the heel regions 62d, 82d of the outer and/or inner layer can have cushioned knit construction. A cushioned knit construction includes knitted terry loops.
The double layer knitted upper can be formed from any number of yarn types, such as spun yarns or continuous filament yarns. Spun yarns may include natural fibers, synthetic fibers, or blends of natural and synthetic fibers. Natural fibers include cotton, wool, bamboo, flax, hemp, or others. Synthetic fibers may include polyethylene terephthalate (PET), polyolefin, polyamide 6, polyamide 6,6, polylactic acid (PLA) fibers, viscose rayon, acrylic, or other fiber types. Suitable thermoplastic synthetic staple fibers may be mono-component or bi-component type fibers. A variety of yarn spinning types can be used, such as ring spun, open end, air-jet, compact spinning, and the like. Continuous filament yarns may include either or both mono-component or bicomponent filaments types. Continuous filament yarns can be polyethylene terephthalate, polyolefin, and/or polyamide 6, polyamide 6,6, polylactic acid filaments. Yarns used in the knit fabric can have a range of yarn counts. For instance, in one example, the knit yarn can have a count in a range between about 50 denier to about 250 denier (or higher). The yarns are not limited to the stated range of deniers. Binding yarns are used in selected regions of the outer knitted layer 60 and the inner knitted layer 80 to help consolidate the outer layer and the inner layers together. Binding yarns may be low melt thermoplastic yarns, or yarns such as thermoplastic polyurethane yarns.
Another embodiment of the present disclosure is a method for forming a footwear article 10. The method may include a knitting phase form forming a circular knitted blank 130. Following the knitting phase, the method may include an assembling phase where the circular knitted blank 130 is formed into an upper knitted component 30 and the sole component 20 is attached to foot bed 41 of the upper knitted component 30. Referring to
The knitting phase utilizes a circular knitting machine (not shown) familiar to a person of skill in the art. The circular knitting machine may be a double needle machine that includes two cylinders. Alternatively, a circular knitting machine with a cylinder and a dial may be used. The knitting process is described below using a knitting machine with two cylinders for purposes of illustration and clarity. It should be appreciated that other types of knitting machines could be used. Each cylinder has a plurality of needles disposed around the circumference of the cylinder with each needle housed in moveable tracks. A cam assembly engages the needles along each cylinder. Rotational movement of the cam assembly (or relative movement of the cylinders) causes the needles to move up and down the tracks through what is known in the art as the knitting cycle to create courses of interconnected knitted loops of yarns. The courses of knitted loops define the circular knitted fabric blank 130. By altering the knitting cycles and/or holding certain needles in place during knitting, specific knit stitches and/or patterns can be formed into the circular knitted blank 130. The circular knitting machines and the basic circular knitting process is familiar to a person of skill in the art. Various circular knit processes may be used, such as tube circular knitting, narrow tube circular knit jacquard, single knit circular knit jacquard, double knit circular knit jacquard knitting.
Referring to
Circular knitting the fabric blank 130 initiates with the cylinder needles knitting the first toe portion 142 of the first knit section 160. Next, the circular knitting machine knits the mid-sole portion, which includes a first upper portion 144a and the first lower portion 144b. Then, the first heel portion 146 the first knit section 160 is knit adjacent to the first lower portion 144b. During the knitting the first heel portion 146, the knitting machine can selectively drop needles to alter the direction of knitting to form the desired curve of the first heel portion 146. After the first heel portion 148 is formed, the circular knitting machine knits the first ankle portion 148 of the first knit section adjacent 160 to the first heel portion 148 and the first upper portion 144a. At this point, the first knit section 160 is substantially complete. The first knit section 160 comprises the outer knit layer 60 of the double layer knitted upper, as explained below. Accordingly, as the knitting machine forms the first knit section 160, the different knit regions 62a-62f are created in the circular knitted fabric blank 130, as shown.
The knitting process continues to form the second knit section 180. During this phase of knitting, the second ankle portion 248 of the second knit section 180 is formed adjacent to the first heel portion 148. The circular knitting machines knits a second heal portion 246 adjacent to and continuous with the second ankle portion 248. The circular knitting machine knits a second upper portion 244a and a second lower portion 244b of the second knit section 180. The knitting process continues and forms the second toe portion 242 of the second knit section 180 adjacent to the second upper portion 244a and the second lower portion 244b. The second toe portion 242 is formed to the terminal end 134 to complete the knitted blank 130. As the knitting machines forms the second knit section 180, the different knit regions 82a-82g are created in respective areas of the circular knitted fabric blank 130. As illustrated, the formed circular knitted blank 130 is substantially a tubular structure having the shape of two crew-cut socks connected as the ankle portion.
Additional courses of yarns may be added to facilitate transition to the next knitted blank formed by the circular knitting machine. Optional cutting devices are used to cut the completed circular knitted blank 130 from the knitting machine. The circular knitted blank 130 is the ejected out of the knitting machines for later processing.
The completed circular blank 130 may have toe openings 152 and 252 at toe portion 142 and toe portion 242, respectively. The toe openings 152 and 252 can be closed with seams 154 and 254 as illustrated in
The circular blank 130 may be cut to form the ankle opening 32 by removing a panel 156 from the circular knitted blank 130. In an alternative embodiment, the circular knitted blank 103 can be formed to define the ankle opening 32 during knitting. In such an embodiment, the circular knitted blank 130 may form a welted edges along the border of the ankle opening 32 to prevent fraying and provide a place to attach a binding 54 (
When the circular knitted blank 130 is completed, the second knit section 180 is folded into the first knit section 160 to form a double layer knitted upper of the footwear article. At this stage, the double layer knitted upper comprises the outer knit layer 60 defined by the first knit section 160 and the inner knit layer 80 defined by the second knit section 180. In this state, at least two of the plurality of the outer knit regions 62a-62d of the outer knit layer 60 spatially correspond to at least two of the plurality of inner knit regions. In accordance with the illustrated embodiment, the inner knit regions 82a-82e underlie the outer knit regions 62a-62e.
The method may comprise, before folding, positioning a liner component along a lower portion of the first knit section. The liner component is therefore disposed between the outer knit layer and the inner knit layer.
The method may include attaching a sole directly to the outer knit layer of the double layer knitted upper. Attaching the sole to the outer knit layer comprises positioning the double layer knitted upper over a positioning member of an injection-molding device (not shown). Then, the sole component is injection molded onto the outer knit layer of the double layer knitted upper. In addition, the method may include injection molding a plurality of tabs 22a-22d along medial and lateral sides of the double layered knitted upper. The injection molding process may melt the TPU yarns in the specific knitted regions thereby bonding the outer knit layer to the inner knit layer to form a monolithic, double layer knitted upper.
Double layer knitted uppers that are circular knit as described herein have several advantages. A wide range of knit constructions across different regions of the upper is possible while using a single fabric construction. Specific knit structures can be designed into different regions of the footwear article as needed. In addition, complex three-dimensional shapes that better conform to the anatomy of the foot of the wearer may be formed during the knitting process. Because circular knitted uppers are made to conform to the foot of the wearer, fewer assembly steps are required prior to attaching the upper to the sole to create the finished footwear article. Fewer total components in the finished footwear article decreases supply chain complexity and increases production efficiency and output. Furthermore, circular knitted double layer uppers can be manufactured at relatively fast production rates further increasing production efficiency.
Aspects
The present disclosure includes at least the following aspects:
Aspect 1: A footwear article, comprising: a double layer knitted upper having a foot bed, an upper portion continuous with the foot bed, an ankle opening, and an inner void for receiving a foot of a wearer, the double layer knitted upper having:
Aspect 2. The footwear article of aspect 1, further comprising a mid-sole positioned between the outer knit layer and the inner knit layer along the foot bed.
Aspect 3. The footwear article of aspect 1, wherein the outer knit layer and the inner knit layer is a monolithic circular knitted fabric.
Aspect 4. The footwear article of aspect 1, wherein the outer knit layer and the inner knit layer each define a tubular knitted shape.
Aspect 5. The footwear article of aspect 1, wherein the inner knit layer is monolithically knit to the outer knit layer around at least a portion of the ankle opening.
Aspect 6. The footwear article of aspect 5, wherein the outer knit layer and the inner knit layer define a welted edge along at least a portion of the ankle opening.
Aspect 7. The footwear article of aspect 1, wherein the outer knit layer and the inner knit layer include a binding along at least a portion of the ankle opening.
Aspect 8. The footwear article of aspect 1, further comprising at least one attachment member that consolidates the outer knit layer and the inner knit layer together.
Aspect 9. The footwear article of aspect 8, wherein at least one attachment member bonds yarns of the outer knit layer to yarns of the inner knit layer.
Aspect 10. The footwear article of aspect 8, wherein the at least one attachment member are binding yarns.
Aspect 11. The footwear article of aspect 10, wherein the binding yarns are thermoplastic polyurethane yarns.
Aspect 12. The footwear article of aspect 10, wherein the binding yarns are low-melt thermoplastic yarns.
Aspect 13. The footwear article of aspect 10, wherein the outer knit layer comprises first yarns, the inner knit layer comprises second yarns, and wherein the binding yarns have a lower melting temperature than the first yarns and the second yarns.
Aspect 14. The footwear article of aspect 8, wherein the at least one attachment member is an adhesive film.
Aspect 15. The footwear article of aspect 8, wherein the at least one attachment member is a low melt adhesive web.
Aspect 16. The footwear article of aspect 8, wherein at least one of the plurality of outer knit regions comprise the at least one attachment member.
Aspect 17. The footwear article of aspect 16, wherein the double layer knitted upper has a toe portion, wherein a first outer knit region of the plurality of outer knit regions in the outer knit layer extends across the upper portion rearward of the toe portion, wherein the first outer knit region comprises the at least one attachment member.
Aspect 18. The footwear article of aspect 8, wherein at least one of the plurality of inner knit regions comprise the at least one attachment member.
Aspect 19. The footwear article of aspect 18, wherein a second outer knit region of the plurality of outer knit regions extends across the toe portion, wherein a second inner knit region of the plurality of inner knit regions underlies the second outer knit region, wherein at least one of the second outer knit region and the second inner knit region comprises the at least one attachment member.
Aspect 20. The footwear article of aspect 18, wherein the plurality of inner knit regions includes an inner mid region along the foot bed that includes the at least one attachment member.
Aspect 21. The footwear article of aspect 1, wherein the double layer knitted upper has a heel portion that joins the foot bed to the ankle portion, wherein the heel portion has a cushioned knit construction.
Aspect 22. The footwear article of aspect 1, wherein the double layer knitted upper has a toe portion, wherein the toe portion has a cushioned knit construction.
Aspect 23. The footwear article of aspect 1, further comprising a plurality of tabs extending upwardly from the sole along a medial side and a lateral side of the footwear article.
Aspect 24. The footwear article of aspect 23, wherein the plurality of tabs include securing members that are configured to receive a cord.
Aspect 25. A circular knitted blank used to form an article of footwear and having a first terminal end and a second terminal end, the circular knitted blank comprising: a first circular knit section having a first toe portion defining the first terminal end of the circular knitted blank, a first upper portion, a first lower portion coupled to the first upper portion, a first heel portion, and a first ankle portion coupled to the first heel portion, wherein the first circular knit section has a first plurality of knit regions each having a different knit construction; and a second circular knit section having a second ankle portion that is monolithically knit to the first ankle portion, a second heel portion coupled to the second ankle portion, a second upper portion coupled to the second ankle portion, a second lower portion coupled to the second upper portion and the second heel portion, and a second toe portion defining the second terminal end of the circular knitted blank that is opposite to the first end of the circular knitted blank, wherein the second circular knit section includes a second plurality of knit regions each having a different knit construction; wherein the first plurality of knit regions correspond to the second plurality of knit regions, such that, when the first circular knit section is folded into the second circular knit section, the first plurality of knit regions and the second plurality of knit regions overly.
Aspect 26. The circular knitted blank of aspect 25, further comprising an opening located where the first ankle portion and the second ankle portion are joined.
Aspect 27. The circular knitted blank of aspect 25, further comprising at least one attachment member that is configured to bond the first circular knit section and the second circular knit section together.
Aspect 28. A method for forming a footwear article, comprising: circular knitting a tubular knitted blank having a first knit section and a second knit section, wherein a) the first knit section includes a first toe portion, a first lower portion, a first upper portion, a first heel portion adjacent to the first lower portion, and a first ankle portion adjacent to the first heel portion and the first upper portion, and b) the second knit section includes a second toe portion, a second lower portion, a second upper portion, a second heel portion adjacent to the second lower portion, and a second ankle portion adjacent to the second heel portion and the second upper portion; folding the first knit section into the second knit section to form a double layer knitted upper of the footwear article, the double layer knitted upper comprising an outer knit layer defined by the second knit section and an inner knit layer defined by the first knit section, wherein the inner knit layer defines an inner void of the double layer knitted upper; and attaching a sole directly to the outer knit layer of the double layer knitted upper.
Aspect 29. The method of aspect 28, wherein circular knitting includes, in sequence:
Aspect 30. The method of aspect 28, wherein attaching to sole to the outer knit layer comprises: positioning the double layer knitted upper over a positioning member of an injection molding device; injection molding the sole to the outer knit layer of the double layer knitted upper; and injection molding a plurality of tabs along medial and lateral sides of the double layered knitted upper, wherein the plurality of tabs are configured to receive a cord.
The present disclosure describes particular embodiments and their detailed construction and operation. The embodiments described herein are set forth by way of illustration only and not limitation. Those skilled in the art will recognize, in light of the teachings herein, that there may be a range of equivalents to the exemplary embodiments described herein. Most notably, other embodiments are possible. Variations can be made to the embodiments described herein, and there may be equivalents to the components, parts, or steps that make up the described embodiments. For the sake of clarity and conciseness, certain aspects of components or steps of certain embodiments are presented without undue detail where such detail would be apparent to those skilled in the art in light of the teachings herein and/or where such detail would obfuscate an understanding of more pertinent aspects of the embodiments.
This application is a continuation application of United States (US) patent application Ser. No. 15/382,001 filed Dec. 16, 2016, which is herein incorporated by reference in its entirety.
Number | Date | Country | |
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Parent | 15382001 | Dec 2016 | US |
Child | 16394575 | US |