Patent Description:
Articles of footwear can include cushioning systems to enhance the performance of the article and/or the comfort of the wearer. Continued improvements in cushioning systems for articles of footwear are desirable. <CIT> describes a stacked cushioning arrangement for a sole structure. <CIT> describes sole structures and articles of footwear having plate moderated fluid-filled bladders and/or foam type impact force attenuation members.

The claimed invention relates to an article of footwear as defined in appended independent claim <NUM>. Specific embodiments thereof are defined in the appended dependent claims.

Additionally, the term "includes" means "comprises. " Further, the term "coupled" or "secured" encompasses mechanical and chemical couplings, as well as other practical ways of coupling or linking items together, and does not exclude the presence of intermediate elements between the coupled items unless otherwise indicated, such as by referring to elements, or surfaces thereof, being "directly" coupled or secured. Furthermore, as used herein, the term "and/or" means any one item or combination of items in the phrase.

As used herein, the term "exemplary" means serving as a non-limiting example, instance, or illustration. As used herein, the terms "e.g.," and "for example," introduce a list of one or more non-limiting embodiments, examples, instances, and/or illustrations.

Although the operations of some of the disclosed methods are described in a particular, sequential order for convenient presentation, it should be understood that this manner of description encompasses rearrangement, unless a particular ordering is required by specific language set forth below. Moreover, for the sake of simplicity, the attached figures may not show the various ways in which the disclosed things and methods can be used in conjunction with other things and methods. Additionally, the description sometimes uses terms like "provide," "produce," "determine," and "select" to describe the disclosed methods. These terms are high-level descriptions of the actual operations that are performed. The actual operations that correspond to these terms will vary depending on the particular implementation and are readily discernible by one of ordinary skill in the art having the benefit of this disclosure.

As used herein, the directional terms (e.g., "upper" and "lower") generally correspond to the orientation of an article of footwear or sole assembly as it is configured to be worn by a wearer. For example, an "upwardly-facing surface" and/or an "upper surface" of a sole assembly refers to the surface oriented in the "superior" anatomical direction (i.e., toward the head of a wearer) when the article of footwear is being worn by the wearer. Similarly, the directional terms "downwardly" and/or "lower" refer to the anatomical direction "inferior" (i.e., toward the ground and away from the head of the wearer). "Front" means "anterior" (e.g., towards the toes), and "rear" means "posterior" (e.g., towards the heel). "Medial" means "toward the midline of the body," and "lateral" means "away from the midline of the body.

Although the figures may illustrate an article of footwear intended for use on only one foot (e.g., a right foot) of a wearer. One skilled in the art will recognize that a corresponding article of footwear for the other foot (e.g., a left foot) would be a mirror image of the right article of footwear.

Unless explained otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this disclosure belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present disclosure, suitable methods and materials are described below. The materials, methods, and examples are illustrative only and not intended to be limiting. Other features of the disclosure are apparent from the detailed description, claims, abstract, and drawings.

Articles of footwear (also referred to herein as "articles") can include running shoes, soccer shoes, football shoes, rugby shoes, basketball shoes, baseball shoes, tennis shoes, sneakers, boots, sandals, dress shoes, work shoes, and any other type of footwear to which the cushioning systems disclosed herein may be applied. Articles of footwear typically include a sole structure, also referred to as a sole assembly herein, and an upper coupled to the sole structure. The upper forms an interior void configured to receive a foot of a wearer.

<FIG> illustrate a sole assembly <NUM> for use with an article of footwear. Sole assembly <NUM> include a midsole <NUM> and an outsole <NUM>. A bladder system <NUM> is positioned between midsole <NUM> and outsole <NUM>.

Portions of the sole assembly (and the corresponding article of footwear) may be identified based on regions of the foot located at or near that portion of the article of footwear when the footwear is worn on the properly sized foot. For example, as shown in <FIG>, an article of footwear and/or a sole assembly may be considered as having a heel region <NUM> at the rear of the foot, a midfoot region <NUM> at the middle or arch area of the foot, and a forefoot region <NUM> at the front of the foot. Footwear and/or sole assemblies also include a lateral side <NUM> (the "outside" or "little toe side" of the foot) and a medial side <NUM> (the "inside" or "big toe side" of the foot). The lateral and medial sides of the footwear extend through the forefoot, midfoot, and heel regions and generally correspond with opposite sides of the footwear (and may be considered as being separated by a central longitudinal axis LA).

Midsole <NUM> can be formed of any suitable material. For example, midsole <NUM> can be formed from a resilient, polymer foam material, such as polyurethane foam or ethylvinylacetate ("EVA") foam, that extends throughout the length of the article of footwear. The properties of the polymer foam material in the midsole are primarily dependent upon factors that include the dimensional configuration of the midsole and the specific characteristics of the material selected for the polymer foam, including the density of the polymer foam material. By varying these factors throughout the midsole, the relative stiffness and degree of ground reaction force attenuation may be altered to meet the specific demands of the activity for which the footwear is intended to be used. The top surface <NUM> of the midsole <NUM> can be contoured, e.g., to comfortably support and/or help position a plantar surface of a wearer's foot. As discussed in more detail herein, midsole <NUM> can be attached to an upper.

Outsole <NUM> is a ground-contacting member and that can be formed, for example, of a durable, wear resistant material that includes texturing or other features to improve traction. For example, outsole <NUM> can be formed of rubber, phylon, phyllite, thermoplastic polyurethane, and other suitable materials.

As shown in <FIG>, outsole <NUM> is secured to a bottom surface <NUM> of midsole <NUM>. For example, a top surface <NUM> of outsole <NUM> engages with the bottom surface <NUM> of midsole <NUM>, and the two surfaces can be secured together, such as with an adhesive.

<FIG> illustrate a bladder system <NUM> that comprises a pair of fluid-filled bladder elements <NUM>, <NUM> that are stacked with bladder element <NUM> on top of bladder element <NUM>. Each of the bladder elements defines a respective sealable internal cavity <NUM>, <NUM>. Bladder elements <NUM>, <NUM> can be formed with at least one upper recessed portion <NUM> and at least one lower recessed portion <NUM>. The at least one upper recessed portion <NUM> and at least one lower recessed portion <NUM> are surrounded, respectively, by an upper peripheral surface <NUM> and a lower peripheral surface <NUM> that extend above recessed portions <NUM> and below recessed portion <NUM>, respectively. Thus, the recessed portions <NUM>, <NUM> (also referred to herein as depressions) of the bladder elements include surfaces that are spaced apart from a peripheral surface and which are lower in height than the upper peripheral surface or higher in height than the lower peripheral surface.

As shown in <FIG>, upper and lower peripheral surfaces <NUM>, <NUM> extend entirely around a periphery of bladder elements <NUM>, <NUM> to completely enclose upper and lower recessed portions <NUM>, <NUM>. However, in some embodiments, peripheral surfaces <NUM>, <NUM> can only partially surround the upper and/or lower recessed portions (e.g., such as by forming a horseshoe shape with one side of the upper and/or lower recessed portions not surrounded by the upper and/or lower peripheral surface).

Referring again to <FIG>, midsole <NUM> and outsole <NUM> are shaped to collectively define a window <NUM> (e.g., a gap or cutout) through sole assembly <NUM>. Window <NUM> extends from the lateral side <NUM> to the medial side <NUM> in the heel region <NUM> of sole assembly <NUM>. Bladder system <NUM> is received between midsole <NUM> and outsole <NUM> so that only a portion of each of bladder elements <NUM>, <NUM> are visible from the medial and lateral sides of the sole assembly.

As shown in <FIG>, each of the bladder elements <NUM>, <NUM> has an exposed portion and an unexposed portion. The unexposed portion of first bladder element <NUM> includes an upper portion that is not visible through window <NUM> (e.g., as shown in dashed lines). The unexposed portion includes the area of first bladder element <NUM> where a peripheral bond <NUM> (discussed below) is located. Similarly, the unexposed portion of second bladder element <NUM> includes a lower portion that is not visible through window <NUM> (e.g., as shown in dashed lines), which includes an area of second bladder element <NUM> where its peripheral bond <NUM> is located.

When viewed from the lateral or medial side, as shown in <FIG> and <FIG>, adjacent peripheral surfaces of the stacked bladder elements <NUM>, <NUM> (i.e., lower peripheral surface <NUM> of bladder element <NUM> and upper peripheral surface <NUM> of bladder element <NUM>) contact each other along their lateral and medial side surfaces.

In some embodiments, as shown in <FIG>, window <NUM> can be sized so that bladder elements <NUM>, <NUM> do not extend the entire length of window <NUM>. For example, <FIG> illustrates a rear gap <NUM> and a front gap <NUM> on the rear and front sides, respectively, of bladder elements <NUM>, <NUM>. Rear gap <NUM> and front gap <NUM> can provide unobstructed views though window <NUM> from the medial side to the lateral side, and vice versa.

Bladder elements <NUM>, <NUM> can be formed in various manners. For example, each bladder element can be formed by securing a first polymeric sheet <NUM> to a second polymeric sheet <NUM> to define the respective internal cavity <NUM>, <NUM>. First and second polymeric sheets <NUM>, <NUM> are substantially impermeable to the fluid to be contained within cavities <NUM>, <NUM>. First polymeric sheet <NUM> and second polymeric sheet <NUM> can be coupled together (e.g., welded) around their respective peripheries to form a peripheral bond <NUM>.

As shown in <FIG>, first polymeric sheet <NUM> forms the upper peripheral surface <NUM> and a portion of a sidewall <NUM> of bladder element <NUM>, and second polymeric sheet <NUM> forms the lower peripheral surface <NUM> and another portion of sidewall <NUM> of bladder element <NUM>. Peripheral bond <NUM> can be located at a midpoint of sidewall <NUM> or, alternately, positioned closer to the lower peripheral surface <NUM> or the upper peripheral surface <NUM>.

Bladder elements can be thermoformed in a mold assembly, with the first and second polymeric sheets <NUM>, <NUM> being vacuum formed to the shape of the mold assembly during the thermoforming process. The sheets can be bonded to one another to form the peripheral bond by compression during the thermoforming process and fluid can be provided to the internal cavity of the bladder element through a fill tube. After inflation of the bladder element, the fill tube can be plugged and subsequently trimmed prior to assembling the sole assembly or article of footwear. As used herein, a "fluid" includes a gas, including air, an inert gas such as nitrogen, or another gas.

In addition to the peripheral bond <NUM>, first and second polymeric sheets <NUM>, <NUM> can be welded together at one or more internal areas to achieve a desired shape and configuration of the bladder element. For example, as shown in <FIG>, upper and lower recessed portions <NUM>, <NUM> can be formed by bonding the first and second polymeric sheets <NUM>, <NUM> together at an interior bond region <NUM> (e.g., internal weld area) that is spaced away from the peripheral surfaces <NUM>, <NUM>. When an interior bond region is formed on both sides of the bladder element, as shown in <FIG>, for example, the terms interior bond region and interior weld area refer to regions on either the top or bottom of a bladder element.

As shown in <FIG>, midsole <NUM> and outsole <NUM> are sized to receive a respective bladder element <NUM>, <NUM>. For example, midsole <NUM> can comprise a peripheral recessed portion <NUM> and raised surface, such as one or more projections <NUM> extending downward relative to recessed portion <NUM>. Outsole <NUM> can likewise comprise a peripheral recessed portion <NUM> and a central raised surface, such as one or more projections <NUM> extending upward relative to recessed portion <NUM>. Peripheral recessed portion <NUM> is sized to engage with upper peripheral surface <NUM> of bladder element <NUM> and projection <NUM> is sized to engage with upper recessed portion <NUM>. Similarly, peripheral recessed portion <NUM> is sized to engage with lower peripheral surface <NUM> of bladder element <NUM> and projection <NUM> is sized to engage with lower recessed portion <NUM>.

By providing mating surfaces in this manner (e.g., projections extending into recessed portions of the bladder elements and peripheral surfaces of the bladder elements into recessed portions of the midsole/sole), the bladder elements can be better secured in a desired position. In addition to a friction fit between the bladder elements and adjacent surfaces of the midsole and outsole, adhesives can be provided to further secure these elements in position relative to each other. Also, because of the non-linear shapes of the adjacent surfaces described above, in some embodiments, a greater amount of surface area may be available for applying adhesives.

Referring again to <FIG>, the recessed portions of the midsole and outsole are preferably sized to accommodate the peripheral bonds of respective bladder elements entirely within the respective midsole or outsole region, such that the peripheral bond is not exposed by window <NUM>. For example, peripheral bond <NUM> of bladder element <NUM> is received within the midsole <NUM> (i.e., an internal surface of midsole <NUM> contacts and/or covers peripheral bond <NUM>) so that it is not exposed by window <NUM>, and peripheral bond <NUM> of bladder element <NUM> is received within the outsole <NUM> (i.e., an internal surface of outsole <NUM> contacts and/or covers peripheral bond <NUM>) so that it is not exposed by window <NUM>. Receiving the peripheral bonds <NUM> of the bladder elements within the midsole and outsole elements as shown in <FIG>, can improve both the function and aesthetics of the article of footwear. For example, exposed peripheral bonds may be more susceptible to failing by undesired contact with external elements as well as less desirable to view through window <NUM>.

<FIG> illustrates outsole <NUM> as a "cap" that covers only the heel region <NUM> with the midsole <NUM> directly contacting the ground in the midfoot region <NUM> and forefoot region <NUM>. Alternatively, outsole <NUM> can extend the entire length of the bottom of sole assembly <NUM> as shown in <FIG>. In particular, <FIG> illustrates a second outsole member <NUM>. Second outsole member <NUM> can be integrally formed with outsole <NUM>, with both collectively forming an outsole structure joined to midsole <NUM>. In other embodiments, second outsole member <NUM> can be separate from outsole <NUM> and secured to the midsole <NUM> separately from outsole <NUM>-either before, after, or during the securing of outsole <NUM> to midsole <NUM>. Second outsole member <NUM> can extend the length of sole assembly <NUM> or it can only in a midfoot <NUM> or forefoot region <NUM> (e.g., extending from a forward portion of outsole <NUM> to the toe side of sole assembly <NUM>).

<FIG> illustrate features of midsole <NUM> and outsole <NUM> and the manner in which they are shaped to receive the bladder elements described herein. <FIG> is a side view, <FIG> is a bottom view, and <FIG> is a bottom perspective view of an exemplary midsole <NUM>. Midsole <NUM> defines a portion of window <NUM> by the shape of its cutout in the heel region. As shown in <FIG>, peripheral recessed portion <NUM> surrounds a raised surface, projection <NUM>, that extends downward relative to recessed portion <NUM>. Projection <NUM> is sized to be received within upper recessed portion <NUM> of bladder element <NUM>. Thus, the shape of projection <NUM> can vary depending on the shape of upper recessed portion <NUM>. For example, the exemplary projection of <FIG> is tapered towards the end to better accommodate the bladder element <NUM> shown in <FIG>. In addition, projection <NUM> of the illustrated embodiment is oval shaped to correspond to the oval-shaped upper recessed portion <NUM> of bladder element <NUM>. Different shapes and different numbers of projections are possible depending on the shape of the bladder element that is to be received in midsole <NUM>.

<FIG> illustrate an exemplary outsole <NUM> that can be secured to midsole <NUM>, with the bladder system <NUM> positioned therebetween. <FIG> is a side view, <FIG> is a top view, and <FIG> is a top perspective view of outsole <NUM>. As shown in <FIG>, a peripheral recessed portion <NUM> surrounds a central raised surface, projection <NUM>, that extends upward relative to recessed portion <NUM>. In the same manner as described above in connection with projection <NUM> and <FIG>, projection <NUM> is sized to be received within lower recessed portion <NUM> of bladder element <NUM>. Thus, the shape of projection <NUM> can likewise vary depending on the shape of lower recessed portion <NUM>.

The shape of outsole <NUM> can vary to provide a more secure attachment between outsole <NUM> and midsole <NUM>. For example, as shown in <FIG>, outsole <NUM> has a notched portion <NUM> that is sized to be received in a corresponding mating portion <NUM> of midsole <NUM> to provide a more secure fit between the midsole and outsole when the two are coupled together (e.g., with adhesives).

<FIG> illustrates an exemplary embodiment of an article of footwear having a sole assembly as described herein. As shown in <FIG>, an upper <NUM> is secured to a sole assembly that includes midsole <NUM> and outsole <NUM>. A bladder system, including bladder elements <NUM>, <NUM>, is secured within window <NUM> as described herein. As shown in <FIG>, outsole <NUM> can comprise a notched portion <NUM> which engages with corresponding portion <NUM> of midsole <NUM> to provide for a more secure coupling between the midsole and outsole.

It should be understood that the structure of bladder elements described herein can vary. For example, instead of a single fluid-filled chamber, the bladder elements can have multiple, discrete fluid-filled chambers. Such discrete fluid-filled chambers can be inflated at different pressures to create softer or stiffer areas of cushioning. In addition, as discussed above, more than one internal welds can be provided. For example, instead of a single weld area <NUM>, two or more smaller spaced-apart weld areas can be formed with an intermediate fluid-filled region (either as a part of the main chamber of the bladder element or as a separate discrete chamber). If more than one weld areas are provided, a corresponding change can be made in the number of projections provided, as well as a corresponding change in their position and structure. Thus, for example, if the bladder element has two circular internal weld areas instead of a single oval-shaped weld area, two circular projections could be provided instead of a single oval-shaped projection.

In addition to the peripheral bond and one or more internal welds, the shape and characteristics of the bladder elements can be controlled by providing other structures within the bladder element such as tensile members. Additional details about the use of tensile members and/or other internal welds can be found in <CIT>, <CIT>, <CIT>, and <CIT>.

Bladder elements <NUM>, <NUM> can also be formed of different colors and/or with different transparencies. For example, in some embodiments, the bladder elements can be substantially transparent. As used herein, a bladder element is "substantially transparent" if it has a luminous transmittance (i.e., a percentage of incident light that is transmitted) of at least <NUM> percent and haze (i.e., percentage of transmitted light that is scattered) of not more than <NUM> percent.

The various materials used for bladder elements <NUM>, <NUM>, and other embodiments of bladder elements discussed herein, may be substantially transparent. Those skilled in the art will readily understand a variety of methods to determine luminous transmittance and haze of an object, such as a bladder element. For example, the luminous transmittance and haze of the bladder element can be determined according to American Society for Testing and Materials (ASTM) Standard D1003-<NUM>, Standard Test Method for Haze and Luminous Transmittance of Transparent Plastics. Additionally, in some embodiments, the bladder elements may have a tinted color.

Claim 1:
An article of footwear comprising:
a midsole (<NUM>) having a lower surface with a first recessed portion (<NUM>);
an outsole (<NUM>) coupled to the lower surface of the midsole (<NUM>), the outsole having an upper surface with a second recessed portion (<NUM>);
a first bladder element (<NUM>) having at least one chamber filled with a fluid, the first bladder element (<NUM>) having an upper portion contacting the lower surface of the midsole (<NUM>) and extending at least partially into the first recessed portion (<NUM>); and
a second bladder element (<NUM>) having at least one chamber filled with a fluid, the second bladder element (<NUM>) having a lower portion contacting the upper surface of the outsole and extending at least partially into the second recessed portion (<NUM>),
the article of footwear further comprising:
a window (<NUM>) extending between a lateral side and a medial side of the article of footwear, the window (<NUM>) being collectively defined by at least a lower edge of the midsole (<NUM>) and an upper edge of the outsole (<NUM>);
a first exposed portion of the first bladder element (<NUM>) that is exposed by the window and a first unexposed portion of the first bladder element (<NUM>) that is not exposed through the window (<NUM>); and
a second portion of the second bladder element (<NUM>) that is exposed by the window (<NUM>) and a second unexposed portion of the second bladder element (<NUM>) that is not exposed through the window (<NUM>).