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  Compression molded footwear and methods of manufactureUSPTO Application #: 20070199210Title: Compression molded footwear and methods of manufacture Abstract: An article of footwear having an upper, which includes a first foam layer having a first surface and a second surface remote from the first surface, a second foam layer having a first surface and a second surface remote from the first surface, and a middle layer having a first surface and a second surface remote from the first surface. The first surface of the middle layer is affixed to the second surface of the first foam layer, and the second surface of the middle layer is affixed to the first surface of the second foam layer. The upper defines at least a portion of a foot receiving cavity for the article of footwear. (end of abstract) Agent: Lerner, David, Littenberg, Krumholz & Mentlik - Westfield, NJ, US Inventors: David L. Vattes, Peter Dillon USPTO Applicaton #: 20070199210 - Class: 036045000 (USPTO) Related Patent Categories: Boots, Shoes, And Leggings, Uppers The Patent Description & Claims data below is from USPTO Patent Application 20070199210. Brief Patent Description - Full Patent Description - Patent Application Claims
BACKGROUND OF THE INVENTION [0001] The present invention relates generally to articles of footwear and, more particularly, to articles of footwear having multilayer molded uppers. [0002] Typically, many types of footwear are made by what is known as a cut and sew method, in which individual pieces of material are cut out and sewn together to form the three dimensional ("3-D") shape of a footwear upper. In such a process, individual pieces of material are cut out according to a pattern, in which individual pieces are designated to form specified portions of the shoe upper. When the pieces are cut out, they are typically marked according to the portion of the upper which they are intended to form. The individual pieces are bonded, stitched and then lasted, giving the shoe the necessary 3-D shape. Other portions of the shoe may then be attached to the upper, such as an outsole, midsole, footbed, etc. [0003] Such a method requires a large number of steps, each requiring a skilled person for completion thereof. This increases the overall manufacturing cost and can lead to throughput problems arising from bottlenecks in one step of the process. For example, the absence of the person responsible for one step in the process can shut down an entire production line of footwear. Furthermore, the use of such complicated individual pieces leads to a product that is more difficult to design, requiring the design of both the individual pieces and how the pieces will fit together to form the shape of the shoe upper. This further contributes to increased costs of the finished product, and increases lead time when designing the shoe. [0004] Alternative methods of shoe production have been developed which use various molding techniques to create the shoe upper. Such methods generally use a type of thermoformable polymeric material, such as plastic, to create individual parts of the shoe upper or the upper as a whole. One such method includes injection molding of a thermoplastic into a non-planar 3-D mold to form the shape of the shoe upper. This decreases the time needed to form the shoe. However, the injection molding method presents significant additional problems. Specifically, the complicated molds necessary to form the 3-D shape of a shoe upper increase costs and lead time due to the time required to manufacture these molds. Furthermore, although molding creates advantages such as faster forming of the basic shape of the shoe upper, such benefits can be outweighed by the fact that additional process steps must be performed after molding of the shoe in order to control material creep. Creep is when the foaming reaction to heat energy continues causing expansion of the foam material. If not controlled, creep can result in continued expansion of the polymer. This causes the shoe upper to stretch, which affects the fit quality of the shoe. Additionally, because the majority of the shoe upper is formed in a single process step, there are no available intermediate steps that can control factory defects in the upper of the shoe. Such defects typically arise due to the difficulty in controlling the expansion of foam after injection into the mold, particularly during cooling. In order to control such defects, tolerances within the molds need to be widened, which can lead to overall fit problems with the finished product. [0005] An alternative method includes forming a 3-D footwear upper by compression molding a sheet of material, including a layer of thermoplastic polyurethane (TPU) having a predetermined thickness, into a 3-D form. However, this method does not alleviate the expense required by complex 3-D molds or the increased product lead time associated therewith. In addition to being able to control expansion of the polymer during molding, this method allows additional materials to be added to shoe upper during formation thereof, which helps to control creep and stretching of the product. This is typically accomplished by interposing between two moldable, thermoplastic layers, a fabric or other suitable material that possess appropriate tensile properties. [0006] Limitations in such a process arise, particularly from the materials, namely TPU, that are used in the 3-D compression molding. Such materials are often somewhat thick or dense, resulting in shoe uppers that are too rigid or inflexible for practical purposes of footwear. The relative weight of TPU can also make it less desirable for use in a shoe upper. For example, the specific gravity of TPU can be approximately 1.0 to 1.1 where other materials, such as EVA foam, can be up to five times lighter. Additionally, footwear made from material including TPU retains heat and can make the foot hot, causing discomfort to the wearer. [0007] Additionally, it is difficult to mold a 3-D shape from a single sheet of material having both thermoplastic and fabric materials, fabric not being thermoplastic. This causes difficulty in molding the complex 3-D shape of the shoe upper because thermoplastic and non-thermoplastic materials conform to the mold differently. This can tend to separate the materials during forming. All of the materials to be molded in such a process must possess thermoformable properties. The use of non-thermoformable materials can cause problems in the overall integrity of the product or the reliability of the process, leading to increased factory defects from the difficulty to control the molding process. Additionally, compression molding of a 3-D form from a flat substrate of material can lead to thinning of certain layers of the material during formation because the material must stretch to conform to the mold. This can weaken the overall material or diminish the foot protective properties of the materials used to form the upper. It also limits the ability of the shoe to be formed with decorative or protective features on the shoe upper. Stretching can also make it difficult to control the overall compression of the foam, which is desirous in compression molding because compression helps to bond the layers of material together. [0008] Therefore, it is necessary to provide footwear uppers that possess the advantages of foam, particularly with respect to protection of the foot, durability, and other such properties, while providing a shoe with acceptable flexibility and ease of manufacture. Additionally, with the use of foam and compression molding process, there is a reduction in manufacturing cost, an increase in versatility of design and an increase in the number of various materials which may be used. The shoe, particularly the upper should be structured to utilize the desired properties of foam while minimizing creep and stretching in an effective manner, or to provide other additional beneficial properties to the foam material from which the upper is constructed. It is further desirous to provide a shoe upper that has features formed thereon, but which may be formed from an otherwise planar piece of material. Such features can provide an enhanced, more secure fit to the amorphous shape of the foot and/or provide additional protection. It is also desirous to provide a method for making such footwear that can be carried out in a limited number of process steps while compensating for defects that may arise during other molding processes. Such a method should utilize materials and methods already employed in the art. It is further desired to provide a method for manufacturing such footwear that eliminates the need for complex 3-D molds, while taking advantage of the benefits present in compression molded products. SUMMARY OF THE INVENTION [0009] The present invention relates to an article of footwear having an upper which includes a first foam layer having a first surface and a second surface remote from the first surface, a second foam layer having a first surface and a second surface remote from the first surface, and a middle layer having a first surface and a second surface remote from the first surface. The first surface of the middle layer is affixed to the second surface of the first foam layer, and the second surface of the middle layer is affixed to the first surface of the second foam layer. The upper defines at least a portion of a foot receiving cavity for the article of footwear. [0010] Preferably, at least one of the first and second foam layers of the upper is made from an open-cell foam. Additionally, least one of the first and second foam layers preferably comprises a thermoformable foam, which can include either a termoset foam or a thermoplastic foam. A thermoplastic foam used in the article of footwear may be an EVA foam. [0011] In an upper according to an embodiment of the present invention the first foam layer further includes a feature affixed to the first surface thereof. The feature may be in the form of a protective feature located in, for example, the toe region of the upper. Alternatively, the feature can be a supportive feature located in, for example, the ankle region of the upper. The feature is preferably integrally formed with the first foam layer or the second foam layer. In an alternative embodiment, the feature comprises a coating applied to at least a portion of the first surface of the first foam layer. Such a coating can comprise a latex paint or a lacquer. [0012] In one embodiment of the present invention, the first foam layer, the second foam layer, and the middle layer form a unitary piece of layered material having a first seam and a second seam. The unitary piece of layered material may define a first substantially seamless portion on a medial side of the upper between the first seam and the second seam. The upper may further define a second substantially seamless portion on a lateral side of the upper between the first seam and the second seam. In a preferred embodiment, the first seam is positioned at the heal section of the upper, and the second seam is positioned at the toe section of the upper. [0013] An alternative embodiment of the present invention relates to an article of footwear having a sole and a unitary upper that is formed of a layered material and affixed to the sole. The layered material has a first foam layer, a second foam layer, and a middle layer interposed between the first and second foam layers. The upper defines at least a portion of a foot-receiving cavity of the article of footwear. Preferably, the middle layer is adhesively affixed between the first and second foam layers. The middle layer is preferably a mesh textile material. [0014] It is preferred that the first and second foam layers each comprise a thermoformable foam. Preferably, the thermoformable foam is a thermoplastic foam, and, more preferably, thermoplastic foam is an EVA foam. The EVA foam may comprise an open-cell foam. Alternatively, the thermoformable foam may comprise a polyester, a polyether or a latex foam. [0015] A further embodiment of the present invention relates to a method for making an article of footwear. The method includes providing a first foam layer, a second foam layer and a middle layer, and integrally forming the first foam layer, the second foam layer and the middle layer by interposing the middle layer between the first foam layer and the second foam layer to form a blank defining a profile having first and second mating portions. The method further includes forming an upper defining a portion of a foot receiving cavity from the blank by aligning the first and second mating portions. Integrally forming the first foam layer, second foam layer and middle layer may include compression molding the first and second foam layers and the middle layer together. A first seam can be formed from the first mating portion, and a second seam can be formed from the second mating portion. [0016] In the method according to the present embodiment of the invention, the compression molding may include the use of a mold. The mold can further be used to form a sole for the article of footwear concurrently with the integral forming of the first foam layer, second foam layer and middle layer. Preferably, integrally forming the first foam layer, second foam layer and middle layer further includes adhesively affixing the middle layer between the first foam layer and the second foam layer. In an alternative embodiment, integrally forming the first foam layer, second foam layer and middle layer may include cold molding of the first and second foam layers and the middle layer. Cold molding can be carried out using rollers or plates which may be substantially flat. The method of the present embodiment can further include trimming the layered material after molding thereof. In a further embodiment of the present invention, the method includes applying a coating to the first surface of the first foam layer after compression molding thereof. [0017] Additionally, the method of the present embodiment may further include affixing an insole to the upper at an outside edge thereof so as to define a foot receiving cavity therebetween. A last may then be inserted into the foot receiving cavity of the article of footwear. The upper may then be reheated so as to form the upper to the shape of the last. The upper may then be allowed to cool and the last can be removed from the foot receiving cavity. [0018] A further embodiment of the present invention relates to an article of footwear having a unitary upper and a sole. The upper is formed from a layered material, forms at least a portion of a foot receiving cavity of the article of footwear, and is affixed to the upper. The article of footwear of the present embodiment is formed by the process of providing a first foam layer, a second foam layer and a middle layer and integrally forming the first foam layer, the second foam layer and the middle layer by interposing the middle layer between the first foam layer and the second foam layer to form a blank. The blank preferably defines a profile having first and second mating portions. An upper is formed from the blank by forming first and second seams from the first and second mating portions. The sole is then affixed to the upper. [0019] In a preferred embodiment the first foam layer, second foam layer and middle layer are integrally formed by compression molding. Additionally, the step of integrally forming may include adhesively affixing the middle layer between the first foam layer and the second foam layer. The adhesive used in the step of integrally forming is preferably heat activated. In a further embodiment, the middle layer is formed of a textile material defining a plurality of open portions such that the step of compression molding forces the first foam layer and the second foam layer into mutual contact within the open portions so as provide tensile strength to the layered material. [0020] An additional embodiment of the present invention relates to an article of footwear comprising a sole, and a unitary upper affixed to the sole so as to define a foot receiving cavity therein. The unitary upper is formed of a layered material consisting essentially of a first layer of a thermoformable foam having a first surface and a second surface remote from the first surface thereof, and a second layer having a first surface and a second surface remote from the first surface thereof. The second surface of the first layer is affixed to the first surface of the second layer. The upper defines at least a portion of a foot-receiving cavity. The second layer may be formed from a textile material. [0021] The first surface of the first layer may be disposed toward the foot receiving cavity such that the second surface of the second layer is spaced apart from the foot receiving cavity. Further, the first layer may include a feature affixed to the first surface thereof, which may be integrally formed with the first foam layer. [0022] An alternative embodiment of the present invention relates to an article of footwear including an upper and a bottom affixed to the upper, wherein the upper and the bottom are formed from a unitary piece of layered material. The layered material includes a first layer of thermoformable foam having a first surface and a second surface remote from the first surface thereof and a second layer having a first surface and a second surface remote from the first surface thereof. The second surface of the first layer is affixed to the first surface of the second layer. The second layer may include a first region and a second region, the first region comprising a first material and the second region comprising a second material. The first material may be a rubber and the second material may be a textile. Continue reading... Full patent description for Compression molded footwear and methods of manufacture Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Compression molded footwear and methods of manufacture patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. 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