Patent Application
20070039203
This invention relates generally to an article of footwear, and, in particular, to an article of footwear and a method of manufacturing the same.
A conventional article of athletic footwear includes two primary elements, an upper and a sole structure. The upper provides a covering for the foot that securely receives and positions the foot with respect to the sole structure. In addition, the upper may have a configuration that protects the foot and provides ventilation, thereby cooling the foot and removing perspiration. The sole structure is secured to a lower portion of the upper and is generally positioned between the foot and the ground. In addition to attenuating ground reaction forces (i.e., imparting cushioning), the sole structure may provide traction and control foot motions, such as pronation. Accordingly, the upper and the sole structure operate cooperatively to provide a comfortable structure that is suited for a variety of ambulatory activities, such as walking and running.
The sole structure of athletic footwear generally exhibits a layered configuration that includes a comfort-enhancing insole, a resilient midsole formed from a polymer foam material, and a ground-contacting outsole that provides both abrasion-resistance and traction. The midsole is the primary sole structure element that imparts cushioning and controls foot motions. Suitable polymer foam materials for the midsole include ethylvinylacetate or polyurethane that compress resiliently under an applied load to attenuate ground reaction forces. Conventional polymer foam materials are resiliently compressible, in part, due to the inclusion of a plurality of open or closed cells that define an inner volume substantially displaced by gas. The polymer foam materials of the midsole may also absorb energy when compressed during ambulatory activities.
In double lasted footwear, a portion of the midsole is surrounded by the upper and, therefore, is not visible from an exterior of the article of footwear. During the manufacture of known double lasted footwear, the footwear is initially passed through the lasting line, where the upper is secured to a stroebel sock, with a portion of the upper wrapped about an exterior of at least a portion of the midsole. The upper is then passed through the lasting line again at which point the outsole and the remainder of the midsole are secured to the exterior surface of the upper.
It would be desirable to provide an article of footwear that reduces or overcomes some or all of the difficulties inherent in prior known devices. Particular objects and advantages will be apparent to those skilled in the art, that is, those who are knowledgeable or experienced in this field of technology, in view of the following disclosure of the invention and detailed description of certain embodiments.
The principles of the invention may be used to advantage to provide an article of footwear with improved flexibility, fit, comfort and performance. In accordance with a first aspect, an article of footwear includes an upper having a forefoot portion, a midfoot portion, a heel portion, and a pocket positioned beneath the forefoot portion. A first midsole portion is received in the pocket. An outer sole assembly is secured to the upper. The outer sole assembly is visible from an exterior of the article of footwear and the first midsole portion is not visible from an exterior of the article of footwear.
In accordance with another aspect, an article of footwear includes a stroebel sock and an upper secured to the stroebel sock. The upper has a forefoot portion, a midfoot portion, a heel portion, and a pocket positioned beneath the forefoot portion. A first midsole portion is received in the pocket. An outsole assembly is secured to the upper. The outsole assembly includes a second midsole portion and an outsole secured to a lower surface of the second midsole portion. The second midsole portion and the outsole are visible from an exterior of the article of footwear and the first midsole portion is not visible from an exterior of the article of footwear.
In accordance with yet another aspect, an article of footwear includes an upper having a forefoot portion, a midfoot portion, a heel portion, and a pocket positioned beneath the forefoot portion. A midsole portion has a forefoot portion, a midfoot portion and a heel portion. The forefoot portion is received in the pocket, and the midfoot and heel portions are secured to the upper. An outsole is secured to the midsole portion. The outsole and the heel portion of the midsole portion are visible from an exterior of the article of footwear and the forefoot portion of the midsole portion is not visible from an exterior of the article of footwear.
In accordance with a further aspect, an article of footwear includes a stroebel sock and an upper secured to the stroebel sock, the upper having a forefoot portion, a midfoot portion, and a heel portion. A pocket is positioned beneath the forefoot portion and includes a lateral wing extending downwardly from the upper, a medial wing extending downwardly from the upper, and a strap secured at opposed ends thereof to the lateral wing and the medial wing. A first midsole portion is received in the pocket. An outsole assembly is secured to a lower surface of the upper. The outsole assembly includes a second midsole portion and an outsole secured to a lower surface of the second midsole portion. The second midsole portion and the outsole are visible from an exterior of the article of footwear and the first midsole portion is not visible from an exterior of the article of footwear.
In accordance with yet another aspect, a method of forming an article of footwear includes the steps of providing an upper having a forefoot portion, a midfoot portion, a heel portion, and a pocket positioned beneath the forefoot portion; placing the upper on a last; inserting a first midsole portion into the pocket; and securing an outsole assembly to the upper. The outsole assembly includes a second midsole portion and an outsole secured to a lower surface of the second midsole portion. The second midsole portion and the outsole are visible from an exterior of the article of footwear and the first midsole portion is not visible from an exterior of the article of footwear.
In accordance with yet a further aspect, an article of footwear is formed by the steps of placing an upper on a last, with the upper having a forefoot portion, a midfoot portion, a heel portion, and a pocket positioned beneath the forefoot portion; inserting a first midsole portion into the pocket; and securing an outsole assembly to the upper. The outsole assembly includes a second midsole portion and an outsole secured to a lower surface of the second midsole portion. The second midsole portion and the outsole are visible from an exterior of the article of footwear and the first midsole portion is not visible from an exterior of the article of footwear.
Substantial advantage is achieved by providing an article of footwear with a pocket to receive a first midsole portion. In particular, certain embodiments of the article of footwear can provide improved flexibility. These and additional features and advantages disclosed here will be further understood from the following detailed disclosure of certain embodiments.
The figures referred to above are not drawn necessarily to scale and should be understood to provide a representation of the invention, illustrative of the principles involved. Some features of the footwear depicted in the drawings have been enlarged or distorted relative to others to facilitate explanation and understanding. The same reference numbers are used in the drawings for similar or identical components and features shown in various alternative embodiments. Footwear as disclosed herein would have configurations and components determined, in part, by the intended application and environment in which they are used.
The present invention may be embodied in various forms. A preferred embodiment of an article of footwear 10 is shown in
Unless otherwise stated, or otherwise clear from the context below, directional terms used herein, such as rearwardly, forwardly, beneath, rear, front, inwardly, downwardly, upwardly, etc., refer to directions relative to footwear 10 itself. Footwear 10 is shown in
Sole assembly 14, which is generally disposed between the foot of the wearer and the ground, provides attenuation of ground reaction forces (i.e., imparting cushioning), traction, and may control foot motions, such as pronation. As with conventional articles of footwear, sole assembly 14 may include an insole (not shown) located within upper 12, a midsole 22, and an outsole 24. Midsole 22 is positioned beneath upper 12 and functions as the primary shock-attenuating and energy-absorbing component of footwear 10. Midsole 22 may be secured to upper 12 by adhesive or other suitable means. Suitable materials for midsole 22 include polymer foam materials such as ethylvinylacetate or polyurethane, or any other material that compresses resiliently.
Outsole 24 is positioned beneath midsole 22 and may be secured to midsole 22 by adhesive or other suitable means. Suitable materials for outsole 24 include polymers, e.g., polyether-block co-polyamide polymers (sold as Pebax® by ATOFINA Chemicals of Philadelphia, Pa.), and nylon resins such as Zytel®, sold by Dupont. Other suitable materials for outsole 24 will become readily apparent to those skilled in the art, given the benefit of this disclosure. In certain embodiments, sole assembly 14 may not include an outsole layer separate from midsole 22 but, rather, the outsole comprises a bottom surface of midsole 22 that provides the external traction surface of sole assembly 14.
The manufacture of footwear 10 will be illustrated with respect to
A first portion 40 of midsole 22 is illustrated in
As seen in
As can be seen in
In another embodiment, as seen in
In light of the foregoing disclosure of the invention and description of various embodiments, those skilled in this area of technology will readily understand that various modifications and adaptations can be made without departing from the scope and spirit of the invention. All such modifications and adaptations are intended to be covered by the following claims.
