RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Application No. 61/679,516 filed on August 3, 2012, which is hereby incorporated by reference in its entirety.

BACKGROUND

Field

[0002] The present invention relates generally to footwear and methods of manufacturing the same.

Description of Related Art

[0003] There are needs for footwear more beneficial to the musculoskeletal health of feet. There are also needs for footwear that can be disassembled, whereby components of the footwear can be recycled. There are also needs for non-hazardous, less costly, and/or less time-consuming methods of manufacturing footwear. The present application is directed to both beneficial footwear and its method of manufacture.

[0004] The current methods of manufacturing footwear involve securing an upper to a lower by problematic means. For example, upper and lower footwear components are commonly affixed together with an adhesive. Many adhesives are environmental contaminants, known to be hazardous to the health of those involved in manufacturing processes and also harmful to the environment more generally. Adhesives bear further disadvantage in their poor durability, which results in the upper and lower components separating with wear over time. Furthermore, many adhesives are hard and inflexible when dry, and cause footwear to become less flexible, even in cases where adhesives are used to combine flexible upper and lower components.

[0005] Upper and lower components also may be affixed together with locking plugs, without or in combination with adhesive. This means of attachment is similarly disadvantageous because of its poor durability, where the textile upper can become unplugged from the lower with wear over time. Additionally, the plugs result in uneven internal surfaces of the footwear, which must be padded to avoid discomfort. [0006] The current methods of manufacturing footwear are further deficient in the means by which the components comprising the upper are affixed to form the upper. For example, uppers are typically comprised of more than one component, and each component is sewn to at least one other component to form the upper. The process of sewing together upper components is costly and time consuming. Furthermore, the addition of stitching to stretchy textile results in a less stretchy product because the stitching cannot stretch like the textile before it was stitched. Furthermore, the sewn-together portions of the upper are problematic to the process of securing the upper to the lower because the stitching interferes with the effectiveness of attachment means, such as adhesives and/or locking plugs.

[0007] The problematic methods of manufacturing footwear yields problematic product. Footwear currently on the market generally has a lower, or sole, of sufficient hardness and thickness to protect a foot's bottom from exposure to uneven or hazardous ground surfaces. Additionally, modern footwear typically has some amount of structure built-in to support the foot— in the foot's arch, for example. Modern footwear is undesirable because it prevents the foot's natural function by providing unnecessary and detrimental support. Consequently, the foot muscles that would be strengthened by walking or running barefoot go unexercised and fail to be strengthened. Feet made weaker by excessively supportive footwear are more susceptible to chronic injuries, such as stress injuries due to the impact of heel striking. Footwear currently on the market is also problematic in that the sides of the upper, once folded over the lower and glued, create unevenness in the internal cavity of the footwear, thereby requiring padding to avoid discomfort when worn.

SUMMARY

[0008] In one embodiment, a shoe and sock hybrid is provided. The shoe and sock hybrid has a textile upper configured to surround a foot of a wearer and a sole configured to be disposed between the upper and a ground surface in use. An interface exists where the sole is formed onto the upper such that direct contact is provided between the textile upper and the sole. Sections of the textile upper are exposed through the sole, thereby enhancing the flexibility of the shoe and sock hybrid.

[0009] In another embodiment, an article of footwear is provided that has an upper portion configured to surround a foot and a sole affixed without adhesives directly onto the upper portion. Sections of the upper portion are exposed on the bottom surface of the footwear's sole to enhance the flexibility of the footwear.

[0010] In another embodiment, an upper portion of a footwear is provide that is configured to surround at least a portion of a foot. The upper portion has more than one component and an overlay material. The overlay material is used to join two or more components of the upper portion, thereby eliminating the need for stitching.

[0011] In some embodiments, methods are provided for directly forming, e.g., by molding, a sole onto an upper portion of n article of footwear. The article of footwear may be a shoe and sock hybrid or another article of footwear described herein. The method may include forming the sole such that sole provides a layer of the hybrid or footwear and that gaps are provided in the layer of the sole.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] FIG. 1 is a depiction of an inner side view of a shoe and sock hybrid, in accordance with various embodiments of the invention.

[0013] FIG. 2 is a depiction of a top view of an exemplary shoe and sock hybrid, in accordance with various embodiments of the invention.

[0014] FIG. 3 is a depiction of an outer side view of an exemplary shoe and sock hybrid, in accordance with various embodiments of the invention.

[0015] FIG. 4 is a depiction of a bottom view of an exemplary shoe and sock hybrid, in accordance with various embodiments of the invention.

[0016] FIG. 5 is a depiction of a method of manufacturing an exemplary shoe and sock hybrid, in accordance with various embodiments of the invention.

[0017] FIG. 6 is a depiction of a laminate structure sub-assembly, in accordance with various embodiments of the invention.

DETAILED DESCRIPTION

[0018] This Detailed Description describes exemplary embodiments of the invention and is not intended to limit the scope of the specification in any way. Indeed, the invention as described is broader than and unlimited by the preferred embodiments, and the terms used have their full ordinary meaning. [0019] The present application is directed to a new method of manufacturing footwear, whereby a soft, flexible material is affixed directly onto a textile upper. Preferably the flexible material can be in a flowable state during one step of the manufacturing process, e.g., a plastic in liquid state. The method of manufacturing can produce a lower of less than 5 mm in thickness. The method of manufacturing can also produce a more substantial lower, with a thickness ranging from 5 mm to 1.5 cm, or 1.5 cm to 5 cm, or 5 cm to 10 cm. The upper and lower may be joined by any method not requiring the use of adhesive, such as injection molding, resin casting, or cast molding. These methods do not require adhesives and locking plugs, and thereby avoid the environmental hazards, health hazards, durability issues, and/or additional cost associated with commonly used attachment means.

[0020] The present application is further directed to a new method of manufacturing footwear, whereby some or all components of the upper are joined together without stitching. For example, a laminate construction can be provided. In such a construction, an overlay material can be used to join two or more components of an upper together. In various laminate techniques, two components are joined by a bridge component that is affixed to each of the two components. These methods can eliminate the need for some or all stitching, thereby avoiding the associated problems described above. For example, in certain methods, an overlay material may be used to join upper components in regions where stitching would otherwise interfere with the process of affixing together the upper and lower, and/or where stitching would otherwise create a less durable footwear because of a less secure bond between components. As used herein "overlay" is a broad term that refers to the material that is an overlay being on top of an exposed surface of two components, and includes where the overlay is inside, outside, or partly inside and partly outside the finished footwear product.

[0021] The present application is further directed to footwear products comprising an upper formed of suitable material, and a lower affixed directly onto the upper. A stretchable textile is preferred for at least a portion of the upper. The lower preferably is configured to provide optimal support to the arch or foot generally. The lower can be a flexible plastic material. The lower can have a thickness of less than 5 mm in some embodiments. [0022] In preferred embodiments, the plastic material of the lower is placed or formed onto the upper in a manner wherein sections of the upper remain exposed on the footwear's bottom surface. For example, if a bottom section of the upper is formed of a textile, the lower can be formed on the bottom section of the upper such that portions of the textile bottom section of the upper are visible through the lower. These techniques can have a variety of advantages, including enhancing the flexibility of the lower and/or the footwear overall. As illustrated in Figure 4, the exposed sections may be concentrated in the arch of the footwear to enhance the flexibility in that region and provide optimal minimalist support in that region. More particularly, in some embodiments, a majority of the exposed sections are located in the arch region. In other embodiments, substantially all of the exposed sections are located in the arch region. In other embodiments, the exposed areas are concentrated in regions of the sole where ground contact is minimized. Such regions may be located generally in the mid-foot region of the sole. In certain embodiments, the portion of the bottom surface of the footwear where the textile of the upper remains exposed is between about 30% and about 40% of the total surface area of that bottom surface. In other embodiments, the portion of the bottom surface of the footwear where the textile of the upper remains exposed is between about 20% and about 30% of the total surface area of that bottom surface. In other embodiments, the portion of the bottom surface of the footwear where the textile of the upper remains exposed is between about 10% and about 20% of the total surface area of that bottom surface. In other embodiments, the portion of the bottom surface of the footwear where the textile of the upper remains exposed is between about 5% and about 10% of the total surface area of that bottom surface. In some embodiments, the portion of the bottom surface of the footwear where the textile of the upper remains exposed is between about 1% and about 5% of the total surface area of that bottom surface. In other embodiments, no portion of the bottom surface of the textile upper remains exposed.

[0023] Preferably the exposed textile sections on the bottom surface are sufficiently small and the portions of the lower around the exposed sections are sufficiently thick to prevent the exposed textile sections from contacting the ground when worn. For example, a ratio of the widest span of the exposed sections to the thickness of the portions of the lower around exposed sections is about 40 or less, and in some embodiments about 20 or less, and in some embodiments between 2 and 10. This ratio can vary, where preferably the ratio is lower for sections that are likely to contact the ground with greater force, and higher for sections that are likely to contact the ground with less force.

[0024] The exposed sections of the upper can be surrounded by ridges on the lower of any suitable shape. In one embodiment, the exposed textile sections on the bottom surface and the corresponding holes in the lower are hexagonal in shape. In a further embodiments, the exposed textile sections on the bottom surface and the corresponding holes in the lower can be any other shape, e.g., circular, oval, square, etc.

[0025] In some embodiments, the lower comprises a material having a hardness between about 30 and about 100 Shore A. In other embodiments, the lower comprises a material having a hardness between about 50 and about 70 Shore A. In some embodiments, the lower comprises a material having a density between about 0.8 and about 2.0 g/cm ³ . In other embodiments, the lower comprises a material having a density between about 1.0 and about 1.5 g/cm ³ . In some embodiments, the lower comprises a material having a tensile strength between about 10 and about 100 MPa. In other embodiments, the lower comprises a material having a tensile strength between about 20 and about 40 MPa. In some embodiments, the lower comprises a material having a tear strength between about 20 and about 120 K /m. In other embodiments, the lower comprises a material having a tear strength between about 30 and about 50 KN/m. In the preferred embodiment, the lower comprises a material having a hardness of about 60 Shore A, a density of about 1.21 g/cm ³ , a tensile strength of about 30 MPa, and a tear strength of about 40 KN/m.

[0026] In further embodiments, the lower is comprised of a soft, flexible plastic. In one embodiment, the lower is formed from a thermoplastic, such as polyurethane. In another embodiment, the lower is formed from a material manufactured and sold by BASF under the brand name Elastollan ^® Soft 60A.

[0027] In some embodiments, a material or combination of materials may be disposed between the textile upper and the lower. The material or combination of materials may be entirely within the outer perimeter of the lower, e.g., the lower may extend beyond the material or combination of materials such that the lower secures the material onto the textile upper. Such securement is preferably without the use of adhesives or locking plugs. The material may include or be a foam, such as EVA foam, that provides extra cushioning for the foot. In one embodiment, one piece of material may extend from the heel region to the forefoot region. In another embodiment, there may be multiple, e.g., two, pieces of material, such as with one to provide cushioning in the heel region and the other to provide cushioning in the forefoot region.

[0028] Figures 1-4 illustrate details of many new shoe and sock hybrid footwear 10, as well as details of methods for making such footwear. The hybrid footwear 10, shown in Figure 1 , comprises an upper 14 and a lower 18 that is coupled with the upper 14 in a way that enhances the flexibility, durability, and/or minimalist support of the footwear 10. As discussed further below, directly forming the lower 18 on the upper 14 is one way of enhancing the flexibility, durability, and/or minimalist approach of the footwear 10. In this context, the meaning of "directly forming on" includes an arrangement where an upper surface of the lower 18 is contacting a lower surface of the upper 14. In other words, an interface is provided at which the upper 14 and lower 18 contact each other. The interface extends over the vast majority of the surface area of the lower surface of the upper 14.

[0029] Figure 2 shows that the upper 14 may be formed with a plurality of sections joined together. For example, a top panel 22 can be provided that extends over the top of the foot of the wearer. Side panels 26, 32 can be provided that extend between the top panel 22 and a bottom panel 55 of the upper 14. The panels 22, 26, 32 that extend over the top and sides of the foot can be connected to another panel 48 that extends to cover the toes. The panels 22, 26, 32 that extend over the top and sides of the foot also can be connected to a panel 50 that extends around the ankle of the wearer. The panels 26, 32, 48, 50 that form the perimeter of the base of the footwear are connected to a bottom panel 55. Together, the panels 22, 26, 32, 48, 50, 55 form the upper and enclose the space where the foot is received.

[0030] In one embodiment, one or more of the panels 22, 26, 32, 48, 50, 55 are formed of a plurality of materials. Figure 3 shows that the side panel 32 is formed with a plurality of materials. A textile 40 is overlaid by a netted material 41 having holes 45 measuring about 1.1 cm by about 0.6 cm. The textile 40 overlaid by a netted material 41 is further overlaid by a finer netted material 42 having holes 46 measuring about 2 mm by about 1 mm. The netted material 41 is disposed between the netted material 42 and the textile 40. More generally, the textile layer 40 can be provided with one or more outer layers that provide both durability and ventilation. The textile 40 overlaid by netted materials 41 , 42 is further overlaid by an overlay 38, which can provide additional strength to the side panel 32 and/or an aesthetic design. The panels 22, 26, 32, 48, 50, 55 or any sections thereof may be formed of stretchable textile. In certain embodiments, the bottom portion of the upper 14 to which the lower 18 will be affixed, is comprised of at least two layers, one of which is a textile and the other of which is thermoplastic material, such as thermoplastic polyurethane (TPU).

[0031] In one embodiment, bottom panel 55 as shown in Figure 2 is affixed to the panels 26, 32, 48, 50 that form the perimeter of the base of the footwear by stitching or other suitable joining means. Panels 22, 26, 32 that extend over the top and sides of the foot are affixed to panel 48 that extends to cover the toes by means of an overlay 38. The panels 26, 32 that extend over the sides of the foot are affixed to the panel 50 that extends around the ankle by an overlay 38. The side panels 26, 32 can be affixed to top panel 22 by stitching, an overlay material, or a combination of stitching and overlay material. The overlay 38 may be comprised of any material that can be affixed to textiles, including but not limited to polyurethane thermoplastics, vinyls, polycarbonate resins, polypropylene thermoplastics, and polyvinyl fluoride films.

[0032] Figure 4 shows a lower 18 formed of a soft, flexible plastic material 26 affixed directly onto the textile upper 14. The lower 18 preferably has a thickness of less than 5 mm.

[0033] In preferred embodiments, the plastic material comprising the lower 18 is coupled to the upper 14 in a manner wherein textile sections 60 of the upper 14 remain exposed on the bottom surface of the footwear product 10. As discussed above, this configuration provides enhanced flexibility for the lower 18 and the footwear 10. In one embodiment, the exposed textile sections 60 on the bottom surface are sufficiently small and the surrounding plastic lower 18 is sufficiently thick to prevent the exposed textile sections 60 from contacting the ground when worn. In one embodiment, the exposed textile sections 60 on the bottom surface and the corresponding holes in the lower are hexagonal in shape. In a further embodiment, the exposed textile sections 60 on the bottom surface and the corresponding holes in the lower 18, measure about 1.2 cm by about 1.2 cm, point to point. Different size openings and different ratios of open area to covered area can be provided.

[0034] In certain embodiments, the plastic material comprising the lower 18 is directly affixed onto the upper 14, such that the bottom surface of the upper 14 directly engages, e.g., is integrally attached to, the top surface of the lower 18. The lower 18 can have a varying thickness. In some embodiments, the thickness is greater, e.g., between about 1 mm and about 5 mm, in the heel, ball, and toe areas. In some embodiments, the thickness is lesser, e.g., between about 0.5 mm to about 3 mm, in other areas. In some embodiments, the maximum thickness of the lower 18 is about 2.5 mm.

[0035] In one embodiment, the soft, flexible plastic comprising the lower 18 has a hardness measuring 60 Shore A, a density measuring 1.21 g/cm ³ , a tensile strength measuring 30 MPa, and a tear strength measuring 40 KN/m.

[0036] In one embodiment, the soft, flexible plastic comprising the lower 18 is a thermoplastic polyurethane material manufactured by BASF and sold under the brand name Elastollan ^® Soft 60A.

[0037] Figure 5 illustrates a method by which the hybrid footwear 10 can be produced. In the first step 510 of the method, the upper 14 is formed. The panels 22, 26, 32, 48, 50, 55 which form the upper are affixed by stitching or other joining device(s) and/or overlay 38. In certain methods, one or more of the panels 22, 26, 32, 48, 50, 55 are formed of a plurality of materials. Figure 3 shows that the side panel 32 can be formed with a plurality of materials. A textile 40 can be overlaid by a netted material 41 , e.g., having holes 45 measuring about 1.1 cm by about 0.6 cm as discussed above. The textile 40 and netted material 41 can be further overlaid by a finer netted material 42, e.g., having holes 46 measuring about 2 mm by about 1 mm. The textile 40 overlaid by netted materials 41 , 42 can be further overlaid by an overlay 38 to form a desired design. The panels 22, 26, 32, 48, 50, 55 or any sections thereof may be formed of stretchable textile. In certain methods, the bottom portion of the upper 14 to which the lower 18 will be affixed, is comprised of at least two layers, one of which is a textile and the other of which is thermoplastic polyurethane (TPU). The TPU layer can be useful to prevent damage to the upper, such as worming of plastic through the textile during the over-molding process, or any other comparable process.

[0038] In the second step 520 of the method, the upper 14 is placed onto a mold tool for forming the upper 14, such as onto a last formed in the shape of a foot. In some methods, another material is placed onto the mold tool. For example, EVA foam, or any other material or combination of materials, may be placed onto the mold tool in such a manner that the subsequent steps of the method, described below, serve to affix the lower, the material, and the upper without the use of adhesives or locking plugs.

[0039] In the third step 530 of the method, a mold cavity is formed. In the fourth step 540 of the method, liquid phase material that will solidify to form the lower 18 flows into the mold cavity and affixes directly onto the upper 14. The upper 14 and lower 18 may be joined by any method not requiring the use of adhesive, such as injection molding, resin casting, or cast molding. In the preferred method, the flexible plastic material is affixed directly onto the textile upper 14 by a suitable injection molding machine. In the preferred method, the plastic enters a mold through two gates. Because the upper 14 is on the last when the lower 18 is injected onto the upper 14, the resulting lower 18 takes on the contour of the last's bottom, which is the contour a foot bottom. The cavity formed around the last will have appropriate texturing to form the patterns on the lower, including being formed to assure a desired amount of exposed upper.

[0040] In the fifth step 550 of the method, liquid phase material that comprises the lower 18 is allowed to solidify. In the sixth step 560 of the method, the last holding the footwear 10 is removed from the mold. In the seventh step 570 of the method, the footwear 10 is removed from the last.

[0041] The present application is further directed to a new method of manufacturing footwear, whereby some or all components of the upper 14 are joined together by means of an overlay 38, thereby eliminating the need for stitching and avoiding the associated problems described above. This additional step is illustrated by a sub-assembly shown in Figure 6. The overlay 38 may be comprised of any material that can be affixed to textiles, including but not limited to vinyls, polycarbonate resin and polypropylene thermoplastics, and polyvinyl fluoride films. In one embodiment, the step 510 includes joining two or more portions of one of the panels 22, 26, 32, 48, 50, 55 together using an overlay 38. The formed structure is sometimes referred to herein as a laminate or laminated structure.

[0042] Details of one or more implementations of the subject matter described in this specification are set forth in the accompanying figures. Other features, aspects and advantages will become apparent from the description, the figures and the claims.