Articles and methods of manufacture of articles

FIELD OF THE INVENTION

0001This invention relates to an article of footwear comprising a midsole including an airbag and a structural insert within the airbag, the structural insert being formed by a rapid manufacturing additive fabrication technique. The invention also relates to a method of making such an article of footwear.

BACKGROUND

0002Various manufacturing processes exist to form a variety of manufactured articles, such as articles of footwear, apparel, athletic equipment, and the like. For example, a midsole for an article of footwear may be manufactured using one of a number of commonly used molding techniques, such as injection molding, blow molding, compression molding, vacuum molding, and the like. These molding methods often require expensive molding equipment that allows little room for variation in the articles produced from the mold. For instance, any change to the design of the molded article generally would require the creation of a new mold. These manufacturing methods generally required a costly retooling anytime a change was made to the molded article design. In addition, molding processes often result in material waste as some material may be trimmed from the molded article in a post-manufacturing processing step.

0003In addition, conventional molding and article manufacturing methods often leave little or no ability to customize the article, such as an article of footwear, to the particular needs or desires of the wearer. That is, conventional articles of footwear, apparel, athletic equipment, etc. are often mass produced. While some articles are produced in varying sizes, articles are rarely manufactured to the specifications of one particular user.

0004Further, articles, such as articles of footwear, have regions prone to wear, such as flex regions, high stress regions, etc. Early wear in these regions can cut short the useful life of the product while other areas of the product continue to be capable of functioning at a high level in the intended manner.

0005Document <patcit id="pcit0001" dnum="US20050039346A1"><text>US 2005/0039346 A1</text></patcit> describes an insert for a fluid filled bladder.

SUMMARY

0006The invention relates to an article of footwear and a method of making an article of footwear according to the appended set of claims.

BRIEF DESCRIPTION OF THE DRAWINGS

0007A more complete understanding of the present invention and certain advantages thereof may be acquired by referring to the following detailed description in consideration with the accompanying drawings, in which:

0008<figref idref="f0001 f0002 f0003 f0004 f0005 f0006">Figures 1-6</figref> relate to examples useful for understanding the invention, but which do not form part of the scope of protection of the invention as defined by the appended set of claims.

0009<figref idref="f0007">Figure 7</figref> is an example airbag impact attenuating system formed according to aspects of this invention.

0010The reader is advised that the attached drawings are not necessarily drawn to scale.

DETAILED DESCRIPTION

0011In the following description of various example structures, reference is made to the accompanying drawings, which form a part hereof, and in which are shown by way of illustration various example articles and methods for manufacturing these articles, such as footwear, watchbands, apparel, athletic equipment, and the like. Additionally, it is to be understood that other specific arrangements of parts and structures may be utilized, and structural and functional modifications may be made. Also, while the terms "top," "bottom," "front," "back," "rear," "side," and the like may be used in this specification to describe various example features and elements these terms are used herein as a matter of convenience, <i>e</i>.<i>g</i>, based on the example orientations shown in the figures and/or the orientations in typical use. Nothing in this specification should be construed as requiring a specific three dimensional or spatial orientation of structures.

A. General Description of Articles, Such as Footwear, According to Examples useful for understanding the invention

1. Example Articles, Such as Articles of Footwear

0012One aspect relates to articles, such as articles of footwear. Such articles of footwear may include, for example, an upper and a sole structure engaged with the upper. In at least some examples, the upper and/or sole structure may be formed using rapid manufacturing techniques, such as laser sintering, solid deposition modeling, stereolithography, and the like. The upper may include reinforcement portions configured to provide additional durability, wear resistance, etc., in areas of the upper that may be prone to tearing, wear, flex, and the like. The reinforcement portions may be formed of conventional materials and manufacturing processes, for instance, non-rapid manufacturing additive fabrication techniques, or they may be formed using one or more rapid manufacturing additive fabrication techniques. The reinforcement portions may be connected to the upper using known means of attachment, such as stitching, adhesives, and the like.

0013In other examples, portions of the rapid manufactured upper and/or sole structure of the article of footwear may be formed of different materials to provide different mechanical characteristics to different regions of the shoe. For instance, flexible regions may be formed of a first material having properties associated with flexibility to enable flexing of the shoe, while supportive regions, such as an ankle region, may be formed of a second material having properties associated with stiffness and support. In at least some products, the various portions of the shoe may be formed in a single rapid manufacturing process.

0014In still other examples, portions of the rapid manufactured upper and/or sole structure of the article of footwear may be formed from material fused with varying laser intensities in order to provide different mechanical characteristics to different regions of the shoe. For instance, regions in which greater hardness is desired, such as an eyelet region, may receive a higher intensity laser than regions in which flexibility is desired, such as the toe region. Laser radiation intensity may be varied, for example, by altering the laser power, the laser scanning speed, or the laser beam spot size.

0015Specific examples are described in more detail below. The reader should understand that these specific examples are set forth merely to illustrate examples useful for understanding the invention, but which do not form part of the scope of protection of the invention as defined by the appended set of claims, and they should not be construed as limiting the invention.

B. Specific Examples of the Invention

0016<figref idref="f0001">Figure 1</figref> generally illustrates an example article of footwear 100. The article of footwear 100 includes an upper 102 and a sole structure 104. For purposes of reference in the following material, footwear 100 may be divided into three general regions: a forefoot or toe region 111, a midfoot region 112, and a heel region 113, as illustrated in <figref idref="f0001">Figure 1</figref>. In addition, footwear 100 includes two sides: lateral side 114 and medial side (not shown). Lateral side 114 is positioned to extend along the lateral (outside) side of the foot and generally passes through each of regions 111-113. Similarly, the medial side is positioned to extend along an opposite medial (inside) side of the foot and generally passes through each of regions 111-113. Regions 111-113 and medial and lateral sides are not intended to demarcate precise areas of footwear 100. Rather, regions 111-113 and medial and lateral sides are intended to represent general areas of footwear 100 that provide a frame of reference during the following discussion.

0017Generally, upper 102 is secured to sole structure 104 and defines a cavity for receiving a foot. Access to the cavity is provided by an ankle opening 106 located in heel region 113. A lace 108 extends through various apertures in upper 102. Lace 108 may be utilized in a conventional manner to selectively increase a size of ankle opening 106 and to modify certain dimensions of upper 102, particularly girth, to accommodate feet with varying dimensions. Various materials are suitable for use in manufacturing a conventional upper. Those materials used in conventional uppers include leather, synthetic leather, rubber, textiles, and polymer foams, for example, that are stitched or adhesively bonded together. The specific materials utilized for upper 102 may be selected to impart wear-resistance, flexibility, air-permeability, moisture control, and comfort. In some conventional arrangements, different materials may be incorporated into different areas of upper 102 in order to impart specific properties to those areas. Furthermore, the materials may be layered in order to provide a combination of properties to specific areas. In accordance with aspects of this invention, the upper 102 may be formed using a rapid manufacturing additive fabrication technique from suitable materials, such as a thermoplastic elastomer, and may include various reinforcements formed using conventional methods, as well as by using rapid manufacturing additive fabrication techniques, as will be discussed more fully below.

0018Sole structure 104 is secured to a lower surface of upper 102 and includes an outsole 120 and a midsole 122. Outsole 120 forms a ground-engaging surface of sole structure 104 and is formed of a durable, wear-resistant material. Conventional sole structures may be formed of rubber that is textured to enhance traction. The outsole 120 and/or midsole 122 may be formed, using a rapid manufacturing additive fabrication technique, of a thermoplastic elastomer, as will be discussed more fully below. In some embodiments, outsole 120 may be integrally formed with midsole 122 or may be a lower surface of midsole 122. Some conventional midsoles are primarily formed of a polymer foam material, such as polyurethane or ethylvinylacetate, that forms a foam core type impact force attenuation system in the midsole 122. Other conventional midsoles may include a column type midsole impact force attenuation system, such as the one shown in <figref idref="f0001">Figure 1</figref>. Additional midsole impact force attenuation types are available for use in conventional midsoles, including an air bag type impact force attenuation system. These various impact force attenuation systems, including column type, foam core, air bag, and the like (or at least portions thereof), may also be manufactured using rapid manufacturing techniques and associated materials, as will be discussed more fully below.

0019Conventional articles of footwear are generally formed from a variety of different types of materials and a variety of different manufacturing processes. In some arrangements, the upper and sole structure are generally formed as separate pieces and then are joined in a post-manufacture processing step. In forming the upper, a plurality of upper portions may be formed or cut, using conventional methods, and then are connected to each other. The upper portions may be connected by any known means such as stitching, adhesives, mechanical fasteners, and the like. This process often generates a substantial amount of waste associated with trimming each of the individual pieces of the upper to be the correct shape and size for that particular upper or portion of the upper.

0020In addition to forming articles of footwear using conventional manufacturing techniques, the articles of footwear, or portions thereof, may be formed using rapid manufacturing additive fabrication techniques, such as laser sintering, stereolithography, solid deposition modeling, and the like. Rapid manufacturing fabrication techniques involve creating a three-dimensional design in a data file, such as a Computer Aided Design (CAD) file, and building the object of the three-dimensional design in an automated layer by layer process. Essentially, the fabrication equipment reads the three-dimensional design from the data file and lays down successive layers of powder, liquid or sheet material to build the three dimensional object. The layers are joined together by the fabrication equipment, for instance, a high powered laser may be used, to form the three dimensional object of the design. Such rapid manufacturing techniques are generally known in the art.

0021One particular process for forming articles that may be used in accordance with aspects described herein is laser sintering. This process involves creating a three-dimensional design in a data file, such as a CAD file. The laser sintering fabrication equipment reads the CAD file and forms the three-dimensional object of the design, such as an upper or portion of an upper for an article of footwear, using a high powered laser to fuse powders or small particles of plastic, metal or ceramic. The laser selectively fuses powdered material by scanning cross-sections generated from a CAD file or a scan of the part on the surface of a powder bed. After each cross-section is scanned, the powder bed is lowered by one layer thickness, a new layer of material is applied on top, and the process is repeated until the part is completed. Laser sintering, and other rapid manufacturing processes are generally known in the art. One example system is found in <patcit id="pcit0002" dnum="US5156697A"><text>U.S. Patent No. 5,156,697 to Bourell et al.</text></patcit> and is incorporated herein by reference.

0022Articles of footwear formed using rapid manufacturing additive fabrication techniques, and some formed using conventional methods, often require reinforcement at areas that experience flexing or heavy wear or stress. Accordingly, reinforcement portions may be formed to prolong the usable life of the article of footwear by reinforcing the region prone to weakening, tearing, etc. For instance, <figref idref="f0002">FIG. 2</figref> illustrates one example article of footwear 200 including reinforcement portions 202, 204. As shown, the article of footwear 200 generally includes an upper 206 forming a void for receiving a foot of a wearer. In addition, the shoe 200 includes a sole structure 208 that may include a midsole 210 and an outsole 212. In some examples, the sole structure 208 may be formed using conventional methods, such as molding, etc. In other arrangements, the sole structure 208 may be formed using one or more rapid manufacturing additive fabrication techniques. Forming the sole structure 208 using rapid manufacturing techniques may permit complex shapes to be formed, some of which may be impossible to form using conventional manufacturing techniques. Also, forming the sole structure 208 using rapid manufacturing techniques may better allow for customization of the sole structure 208, because the foot of a wearer may be scanned and the sole structure 208 may be manufactured based on the scan of the wearer's foot.

0023The upper 206 may also be formed using conventional manufacturing techniques or rapid manufacturing additive fabrication techniques. The article of footwear 200 of <figref idref="f0002">FIG. 2</figref> also includes a plurality of eyelets 203. In some arrangements, the upper 206 formed using rapid manufacturing techniques may benefit from reinforcement of the eyelet regions of the article 200. Accordingly, eyelet reinforcement portions 202 may be formed and connected to the upper 206 using known means of attachment, such as stitching, adhesives, mechanical fasteners, and the like. For instance, eyelet reinforcement 202 may be formed using rapid manufacturing techniques and connected to the eyelet region 203 of the upper 206 in order to reinforce the eyelets 203 to accommodate a lace or other closure system (not shown). In another example, the eyelets reinforcements 202 may be formed from conventional material (e.g., plastic, metal, leather, textile, etc.) and/or from conventional manufacturing techniques such as molding, extrusion, etc. The eyelet reinforcements 202 may then be connected to the eyelets 203 formed in the upper 206 as a post-manufacturing processing step using known means of attachment, such as stitching, adhesives, mechanical fasteners, crimped metal ring structures, mating snap fit components on the reinforcement and the upper, and the like.

0024The article of footwear 200 of <figref idref="f0002">FIG. 2</figref> also includes a reinforcement 204 configured at a toe region of the article of footwear 200. In some arrangements, the toe region may be considered a high wear region due to a wearer's toe pushing on the inner side of the toe region during use. Accordingly, a regional reinforcement structure, such as reinforcement 204, may be positioned in that region to aid in preventing holes, tearing, etc. The toe region reinforcement 204 may be formed from conventional materials, such as textile, leather, and the like, or it may be formed using a rapid manufacturing additive fabrication technique and associated materials. Using a rapid manufacturing technique to form the reinforcement 204 may permit variations in the thickness of the reinforcement in various regions of the reinforcement. For instance, the reinforcement may be thinner at the rear of the toe region (i.e., closer to the midfoot region of the shoe) rather than at the front of the toe region to provide additional support at the front of the shoe.

0025Further, the shape, size, thickness, etc. of the reinforcement 204 may be customized for a particular wearer. That is, the gait or step cycle and characteristics of the wearer may be studied in order to determine where additional reinforcement may be needed and the reinforcement 204 may be constructed to those specifications using one or more rapid manufacturing additive fabrication techniques or, in some arrangements, conventional manufacturing techniques. As one more specific example, for persons that tend to over-pronate during their steps, additional stiffness and/or wear reinforcement may be provided in the lateral heel area of the sole.

0026The toe region reinforcement 204 may be connected to the upper 206 using known means of attachment, such as adhesives, stitching, mechanical fasteners, mating snap fit components on the reinforcement and the upper, and the like.

0027Additionally or alternatively, the vamp forefoot region includes a flex region that may also benefit from reinforcement. For instance, <figref idref="f0003">FIG. 3</figref> illustrates an article of footwear 300 having a reinforcement 302 extending along this flex region of the upper 306. The reinforcement 302 may be formed of conventional materials and/or conventional manufacturing techniques, or may be formed using a rapid manufacturing additive fabrication technique and associated materials. The reinforcement 302 may be formed as part of the initial rapid manufacturing process to fabricate the article of footwear 300, or it may be formed as a separate piece that may be connected or attached to the upper 306 using known means of attachment, such as adhesives, stitching, mechanical fasteners, mating snap fit components on the reinforcement and the upper, and the like. The reinforcement 302 may be formed to permit flexing of the article of footwear 300 in that region, while providing additional durability and wear resistance in the high stress area of the shoe 300 (for example, when jumping, crouching, etc.).

0028<figref idref="f0004">FIG. 4</figref> illustrates yet another article of footwear 400 having a reinforced region 402. As with the arrangements above, the upper 406 and sole structure 408 of the article of footwear 400 may be formed using conventional materials and conventional manufacturing techniques, or they may be formed using one or more rapid manufacturing additive fabrication techniques and associated materials. However, the collar region 402 of the article of footwear 400 is often a region that receives heavy wear and may be likely to tear, wear down, etc. Accordingly, reinforcement in the collar region 402 may prolong the usable life of the shoe 400.

0029In some arrangements, the upper 406 of an article of footwear 400 may be formed using one or more rapid manufacturing additive fabrication techniques. A collar reinforcement 404 may be formed separately (either from conventional materials and processes or rapid manufacturing materials and processes) and connected to the upper 406 to provide additional wear resistance. Additionally, because the collar region 402 may be an area that can rub and cause irritation on the wearer's skin, the collar reinforcement 404 also may include a soft foam, fabric, or other comfort-enhancing material. The collar reinforcement 404 may be attached to the upper 406 using known means of attachment including stitching, adhesives, mechanical fasteners, and the like. In some arrangements, the collar reinforcement 404 may include a snap fit mechanism that mates with a corresponding snap fit mechanism configured in the collar region 402 of the upper 406.

0030In addition to providing added strength, wear resistance, comfort, etc., the reinforcements described above may also add various design elements to the article of footwear. For instance, the reinforcements may include one or more colors or color schemes to complement the color or colors used in the upper or other portions of the shoe. Additionally or alternatively, the reinforcements may be shaped to provide a complimentary design element to the shoe structure. In some arrangements, the reinforcements may be shaped to include a logo (such as a team logo, mascot, etc.) or a company trademark. In some arrangements, the properties of one region may transition into the properties of another region.

0031Further, resin (colored or uncolored) may be brushed, painted, sprayed, etc. onto various regions of an article of footwear formed using rapid manufacturing techniques to provide additional aesthetic enhancement, as well as additional durability to regions of high wear and/or stress. The resin may be brushed onto the shoe after the shoe has been formed, as a post-fabrication processing step. The process may include resins of varying colors, etc. in order to enhance the appearance of the shoe while providing added durability to various regions of the shoe or to the entire shoe, as desired. Various resins that may be used and techniques for applying the resin are discussed more fully in <patcit id="pcit0003" dnum="US255496A" dnum-type="L"><text>U.S. Patent Application No. 12/255,496</text></patcit>, entitled "Articles and Methods of Manufacture of Articles" to which this application claims priority and which is incorporated herein by reference in its entirety.

0032In addition to the reinforcement portions and techniques described above, an article of footwear may be formed using more than one material during a rapid manufacturing additive fabrication process. For instance, the article of footwear may be formed from a single design file including the design, specifications, etc. of the shoe. During rapid manufacturing of the shoe, using a single type of rapid manufacturing process, multiple materials may be used to provide different characteristics or properties to different regions of the shoe.

0033For instance, the article of footwear 500 in <figref idref="f0005">FIG. 5</figref> may be formed using one or more rapid manufacturing additive fabrication techniques. The layer-by-layer process used to fabricate the shoe 500 may include different materials for different regions of the shoe 500. For instance, additional flexibility may be desired in a toe region 502 of the shoe 500, while additional stiffness may be desired in the lateral side 504 and medial side (not shown) of the upper 506 being formed. Materials providing these differing properties may be used in the same rapid manufacturing additive fabrication technique. For instance, a layer of the powder being fused may include a first material in one area or portion of the article and a second material, different from the first material, in another area or portion of the article. Accordingly, two or more different materials may be used to form, from a single rapid manufacturing process, the shoe 500 having the desired properties. In some examples, portions of the article of footwear may be formed using a thermoplastic elastomer, such as DuraForm Flex plastic manufactured and sold by 3D Systems, or other similar materials, such as manufactured by Advanced Laser Materials, LLC (e.g., ALM Flex) and Evonk Industries (e.g., Evonik Soft Touch), various powders, any generally plastic-like material, and the like.

0034In still other arrangements, the rapid manufacturing additive fabrication technique used to manufacturing the article may include a laser having varying intensities, such that higher or lower intensities may be used when forming various regions of the article of footwear. For instance, with further reference to <figref idref="f0005">FIG. 5</figref>, the toe region 502 may be fused using a laser of lower intensity in order to maintain the flexibility of the material in that region. However, a higher intensity laser may be used to fuse the material of the lateral side 504 and medial side of the upper 506 in order to provide additional stiffness and support in those regions. This arrangement using lasers of varying intensities in different regions of the foot may be performed using various known rapid manufacturing additive fabrication techniques. Further, various lasers may be used to manufacture the articles. In some arrangements, a 50 watt carbon dioxide DEOS Class IV laser may be used.

0035In other arrangements, regions in which additional hardening would be desired, such as the eyelet region (203 of <figref idref="f0002">FIG. 2</figref>), may be fused with a higher intensity laser than other regions of the shoe. This may aid in reinforcing the eyelet region of the article.

0036Varying the intensity of the laser may permit further customization of the article of footwear. For instance, varying the intensity of the laser used in fabricating various regions of the shoe may alter the density, stiffness, etc. of the shoe such that the article being formed may be "tuned" to desired specifications. These specifications may be unique to one or more identified users. This arrangement provides the ability to alter the properties of the article for each shoe fabricated, if desired, without requiring costly molds to be manufactured in order to produce the articles.

0037<figref idref="f0006">Figures 6A and 6B</figref> illustrate yet another arrangement of a portion of an article of footwear that may be formed using one or more rapid manufacturing additive fabrication techniques. <figref idref="f0006">Figure 6A</figref> illustrates a top view of a midsole 600 of an article of footwear. The midsole 600 generally includes a plurality of apertures 602 distributed throughout a top surface 604. The apertures 602 may extend through a portion of the midsole 600 or may extend completely through the midsole 600 from the top surface 604 to a bottom surface 606. <figref idref="f0006">Figure 6B</figref> is a cross section of the midsole 600 of <figref idref="f0006">FIG. 6A</figref> taken along line A-A. The figure illustrates one example in which the apertures 602 extend partially through the midsole 600. The midsole 600 may be formed using one or more rapid manufacturing additive fabrication techniques. Using these techniques will allow any number, shape, arrangement, size, etc. of apertures to be formed in the midsole 600. For instance, larger or smaller apertures may be formed, apertures of varying shapes including square, rectangular, triangular, trapezoidal, hexagonal, etc. may be formed, the pattern of apertures may vary depending on the region of the midsole, etc.

0038<figref idref="f0006">Figure 6B</figref> further includes an insole member 610. The insole member 610 includes a base 612 and a plurality of projections 614. The projections 614 are formed of a shape and size to correspond to the apertures 602 formed in the midsole 600. The insole member 610 and projections 614 may provide additional impact attenuation, support, comfort, etc. for the wearer. The insole member 610 may be formed using a rapid manufacturing additive fabrication technique or by conventional techniques.

0039In some arrangements, the size, arrangement, etc. of the apertures 602 and corresponding projections 614 may be customized to a particular user. For instance, a scan of a wearer's foot may be taken and additional impact attenuation may be provided in various regions based on the results of the scan.

0040According to the invention, rapid manufacturing additive fabrication techniques is used to form inserts for airbags to be used in midsole impact attenuation systems. A midsole includes an inflated airbag formed of conventional materials. The airbag includes an insert to aid in maintaining the desired shape of the airbag. The insert is attached to the airbag at various locations in the bag interior to help control the shape of the airbag when it is inflated. The use of rapid manufacturing to fabricate the insert allows the insert to be customized to the needs and/or desires of the wearer, as well as to any desired size, shape, etc. in order to maintain the desired shape of the airbag. <figref idref="f0007">Figure 7</figref> illustrates one example airbag 700 including an insert 702 formed using one or more rapid manufacturing additive fabrication techniques. The insert 702 may be sized, shaped, configured, etc. based on a user's desires, specifications based on features of a user's foot, etc.

0041In still other arrangements, one or more structures arranged in the midsole to hold or fasten the airbag in place may be formed using one or more rapid manufacturing additive fabrication techniques. For example, brackets, clips, grooves, frames, pockets, or other structures for securing the airbag that may be difficult or impossible to manufacture using conventional methods of manufacture may be formed using rapid manufacturing.

0042In still other arrangements, various parts may be manufactured using rapid fabrication additive techniques inside of other parts formed from the same process. For instance, a small part may be manufactured inside a hollow cavity in a larger part to save time and materials. This process would be similar to Russian dolls with smaller dolls nesting inside larger ones. The CAD file created may include the design for the small part and the larger part and the part may be manufactured in one process.

0043Further still, some articles manufactured using rapid fabrication additive techniques may be formed in a collapsed condition in order to conserve space. For instance, similar to a paper bag that is stored collapsed along various creases and fold lines, the articles may be formed using rapid manufacturing in a collapsed condition then expanded upon use.

0044For example, an article of footwear may be formed of a plurality of interlocking rings. The rings may vary in size in different regions of the article of footwear or may be the same size throughout. During manufacture of the article, the rings may be formed in a collapsed condition. That is, the rings may be formed in a stacked formation to produce an article having a very compact shape. However, the rings may be expanded upon opening or expansion of the article to provide the article in an expanded and/or usable condition.

0045Although the above arrangements have been described for use in manufacturing articles of footwear, aspects may be used with a variety of articles including apparel, athletic equipment, such as hockey sticks, shin guards, lacrosse sticks, shoulder pads, etc., watch bands, jewelry, eye glasses, and the like.

0046The arrangements described above allow for customization of articles based on a user's specification, desires, etc. In addition, the use of rapid manufacturing fabrication techniques to form various articles minimizes material waste associated with manufacturing the article. When manufacturing conventional articles, material is often trimmed from the article in order to obtain the desired size or shape of the article. In the method described herein, the three-dimensional design file can be created having the particular desired dimensions of the article. The article is then built to those particular dimensions. No additional material is created that may need to be removed to obtain the desired size and shape of the article.