Abstract:
The invention advantageously provides enhanced support of the foot wearing a shoe according to the invention, while eliminating unnecessary manufacturing steps. According to the invention, an upper, an insole, and an outsole are provided to manufacture a shoe. The outsole comprises a heel, an arch, and a plantar region. A cavity is formed in one or more of the heel, arch and plantar regions of the outsole. A cushioning pad is permanently affixed in the cavity. The upper, insole and outsole are then assembled to make the shoe according to the invention. The pad functions integrally with the outsole in cushioning shock to a given area of the foot wearing the shoe. A midsole and the manufacturing process for making the same are no longer needed as a result.

Description:
RELATED APPLICATIONS 
     The present application is a continuation-in-part (CIP) and claims the priority of copending U.S. application Ser. No. 09/347,051 filed Jul. 2, 1999, now U.S. Pat. No. 6,408,544 entitled “FLEX SOLE”, which is incorporated by reference herein. The invention is also related to copending U.S. application Ser. No. 09/373,122 filed Aug. 12, 1999, entitled “FLEX SOLE”, which is also incorporated by reference herein. 
    
    
     FIELD OF THE INVENTION 
     The invention relates to footwear or shoes, particularly walking or athletic shoes. 
     BACKGROUND OF THE INVENTION 
     Footwear can be designed to provide a variety: of stylistic and functional benefits. A particular functional benefit is the comfort of the wearer of the shoe. Particularly when walking or running, the flexibility and shock absorption of the shoe determine the amount of comfortable support provided to the feet of the shoe wearer. 
     Shoes normally worn for active use, e.g., extensive walking or fitness sports, typically consist of an upper (of canvas, leather or other supple fabric material) joined to an outer sole (of rubber, leather or other durable material) having a bottom that contacts the ground. The inner surface of the outer sole, i.e., outsole, has distinct regions that contact corresponding portions of the wearer&#39;s foot sole. For example, the outsole can have distinct heel, arch and plantar regions that underlie the respective portions of the foot. These regions of the outsole can be specifically adapted to provide functional benefits to the parts of the foot that are supported by them. A highly flexible inner sole, i.e., insole, is usually provided that directly contacts the wearer&#39;s foot and is positioned between the foot and the upper surface of the outsole. The insole has an upper surface of fabric or soft leather to give added comfort and breathability to the sole of the foot. The outsole needs to embody both flexible and durable characteristics, to resist wear from pavement and torsional stresses, also to cushion shock from impact due to foot motion. 
     Others in the art have sought to provided added shock absorption to the outsole by providing added layers or members in various regions of the outsole. For example, U.S. Pat. No. 4,783,910 to Boys, II et al., provides a midsole with a discrete heel capsule to cushion G-forces, in conjunction with an anti-torsion heel member. U.S. Pat. No. 1,994,681 to Bliinifeld, U.S. Pat. No. 4,245,406 to Landay, et al., and U.S. Pat. No. 5,839,208 to Huang disclose outsoles having inner cavities presenting patterns of ribbed structures that are joined to the sides of the outsole. Such structures are said to enhance the shock-absorbing support function of the outsole and its torsional stability. 
     U.S. Pat. No. 4,794,707 to Franklin, et al., shows a midsole with an internal dynamic rocker element disposed in the forefoot of the midsole, said to enhance walking comfort. 
     U.S. Pat. No. 4,663,865 to Telecemian has a first set of ribs that extend from within the heel cavity and a second set of ribs extending diagonally through the arch cavity, both sets dovetailing into the floor of the plantar cavity. A resilient cushion is located in the plantar cavity, being shaped and sized corresponding to that cavity. However, the separate cushion does not form an integral part of the inner-plantar cavity of the outsole, but rather functions as an integral component of the midsole than of the outsole. Moreover, such a cushion requires additional steps to assemble together with the midsole during the manufacturing process. 
     Therefore it is desirable to provide a strategically positioned cushioning support member in a strategic functional region of the outsole activity, which member functions integrally with the outsole in cushioning shock to a given area of the foot of the shoe wearer. 
     It is further desirable to-provide a cushioning member that is fabricated as part of the inner cavity of the outsole, so that the member is joined thereto and functions integrally with the outsole, versus other components of the shoe during wear. 
     It is still further desirable to provide an integral cushioning member that functions together with other stabilizing members found within the inner cavity of the outsole. 
     SUMMARY OF THE INVENTION 
     The invention advantageously provides enhanced support of the foot wearing a shoe according to the invention, while eliminating unnecessary manufacturing steps. An upper sole, an insole, and an outsole are provided, to manufacture a shoe according to the invention. The outsole comprises a heel, an arch, and a plantar region. A cavity is formed in one or more of the heel, arch and plantar regions of the outsole. A cushioning pad is permanently affixed in the cavity. The upper sole, insole and outsole are then assembled to make the shoe according to the invention. The pad functions integrally with the outsole in cushioning shock to a given area of the foot wearing the shoe. A midsole and the manufacturing process for making the same are no longer needed as a result. 
     In a preferred embodiment of the invention, the outsole is made of a flexible polymeric material having a given density and the pad is molded in place within the plantar region, the pad being formed of a different polymeric material than the outsole, such that the plantar and heel regions are of differing densities, respectively. 
     In other embodiments of the invention, injection molding is used to mold the insole and the outsole (with the cushioning pad attached) into a bonded insole/outsole in a single molding step. Alternatively, injection molding is used to mold the upper sole, the insole, and the outsole in a single molding step, depending on manufacturing requirements. A further advantage of the invention is the flexibility of selecting a molding process suitable for the particular manufacturing situation. 
     In a further embodiment of the invention, the cavity is defined by a plurality of ribs (made of, e.g., thermal plastic rubber or TPR) integrally formed on the peripheral wall of the outsole. The cushioning pad (made of, e.g., ethyl vinyl acetate or EVA) is placed in the cavity as defined by the ribs. The peripheral wall and bottom of the outsole are molded in a first stage. The cushioning pad is made separately. The ribs are then molded in a second stage. The cushioning pad is permanently affixed by adhesion to the top surface of the bottom of the outsole in the cavity and to the surrounding ribs after the ribs are molded. In an alternative embodiment of the invention, the ribs are molded while the cushioning pad is in place in the cavity of the outsole. 
     In yet another preferred embodiment of the invention, a plurality of ribs form a structure defining a series of combs that articulate with the peripheral wall of the outsole, the arrangement further delimiting an inner periphery of the cavity, wherein the pad is joined to that inner periphery. In a further preferred embodiment, the cavity and pad are shaped to correspond to the contours of the peripheral walls of the outsole. 
     In an additional embodiment of the invention, a plurality of ribs form a structure defining a series of open combs that extends transversely across the outsole and articulates with the peripheral wall of the outsole within one or more of the heel, arch and plantar regions. It is further preferred that the pad be molded in place within the combs of the plantar region. 
     An advantage of the invention is that a strategically positioned cushioning support pad can function in a strategic region of the outsole, as an integral part of the outsole, in cushioning shock to a given area of the foot wearing a shoe according to the invention. 
     Another advantage of the invention is that the cushioning pad can be fabricated as part of the cavity of the outsole, so that the pad is joined thereto and functions integrally with the outsole, versus other components of the shoe during wear. 
     Yet another advantage of the invention is an integral cushioning pad that functions together with other stabilizing members (e.g., ribs) found within the cavity of the outsole. 
     A further advantage of the invention is enhanced support and shock absorption by providing an outsole with selected cushioning capacity where needed, without the necessity of a separately engineered midsole. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other features, aspects, and advantages of the invention will become readily apparent with reference to the following detailed description of a presently preferred, but nonetheless illustrative embodiment when read in conjunction with the accompanying drawings, in which like reference designations represent like features throughout the enumerated Figures. The drawings referred to herein will be understood as not being drawn to scale except if specifically noted, the emphasis instead being placed upon illustrating the principles of the invention. In the accompanying drawings: 
     FIG. 1 is an exploded perspective view of the invention in a preferred sports shoe, including an upper, a fabric insole and an outsole with a plantar pad, shown prior to assembly; 
     FIG. 2 is a partial perspective view of the internal plantar region of the outsole of FIG. 1, showing the cushioning pad formed on to the floor of the plantar cavity; 
     FIG. 3 is a cross section taken at lines  3 — 3  of FIG. 2; 
     FIG. 4 is a flow diagram illustrating the general methodology of the invention; 
     FIGS. 5 and 8 are flow diagrams illustrating different embodiments of the method for making a shoe according to the invention; 
     FIGS. 6-7 are diagrams illustrating embodiments of the bonded insole/outsole with a cushioning pad according to the invention; 
     FIGS. 9-10 are flow diagrams illustrating different embodiments of the molding process in making a shoe according to the invention; 
     FIG. 11 is a perspective view of a shoe showing an alternative construction of the pad of the invention located in the plantar region of the outsole; 
     FIG. 12 is a cross sectional view taken substantially along line  12 — 12  of FIG.  11 . 
     FIG. 13 is a perspective view of a shoe showing another, alternative construction of the pad of the invention located in the plantar region of the outsole; and 
     FIG. 14 is a cross sectional view taken substantially along line  14 — 14  of FIG.  13 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     According to the invention, elements of a preferred form of footwear are generally shown by shoe  10 , in FIGS. 1-3 and  11 - 14 . More specifically and for purposes of illustration, FIGS. 1-3 and  11 - 14  generally show one or more elements of only a representative shoe  10 , while a corresponding shoe of the pair of footwear is not shown. Shoe  10  comprises of an upper  12 , an insole  14 , an outsole  16  and a pad  18  having a structure and function that shall be detailed below. Those skilled in the art will further appreciate that the invention could take the form of the sports shoe  10  depicted or, alternatively, the footwear could be a walking shoe, hiking boot or other footwear for active use. Similarly, the materials used for the various elements could be leather or other synthetic materials. 
     Further according to the invention, the outsole  16  of the shoe  10  has a peripheral wall  20  delimiting a plantar  22 , a heel  24  and an arch  26  region of the outsole. As shown in FIGS. 1-3, an inner cavity  28  is preferably formed in at least one of the plantar  22 , heel  24  and arch  26  regions, the cavity having a floor  30 . In the embodiment of the invention shown in FIGS. 1-3, cavity  28  is located in the plantar region  22 . Pad  48  is a separate cushioning element preferably located within the plantar cavity  28  and bonded to floor  30 , where the pad  18  is formed as an integral functional part of the&lt;outsole  26 . 
     FIG. 4 is a flow diagram illustrating the general methodology in manufacturing a shoe according to the invention. FIGS. 1-3 are also referred to herein in describing the general method of the invention. Referring to FIG. 4, an upper  12 , an insole  14 , and an outsole  16  are provided in step  111 . The outsole  16  comprises a heel  24 , an arch  26 , and a plantar region  22 . A cavity  28  is formed in the outsole  16  in step  113 . A cushioning pad  18  is permanently affixed in the cavity  28  in step  115 , thereafter serving as an integral, functional part of the outsole  26 . The cavity  28  can be located anywhere in the outsole  16  where cushioning support is needed, e.g., the heel  24 , the arch  26 , or the plantar region  22 . This provides an advantage and particular flexibility for selecting cushioning capacity where needed, without requiring a separately engineered midsole. The upper  12 , the insole  14 , and the outsole  16  (with the affixed pad  18 ) are then assembled to form a shoe according to the invention (step  117 ). 
     For optimal manufacturing efficiency, the upper  12  the insole  14 , and the outsole  16  are made separately and assembled later to form the shoe  110 . FIG. 5 is a flow diagram that illustrates such an embodiment of the method of the invention. Elements of a shoe according to the invention (as shown in FIGS. 1-3) are also referred to herein in describing this embodiment of the method of the invention. Referring to FIG. 5, the upper  12 , the insole  14 , and the outsole  16  are made on an individual basis (steps  121 ,  123  and  125 , respectively). The cavity  28  is formed in the outsole  16  in step  127 . The cushioning pad  18  is permanently affixed in the cavity  28 , serving as an integral, functional part of the outsole  16  in step  129 . After the cushioning pad  18  is affixed in the cavity  28  of the outsole  16 , it is bonded with the insole  14  (step  128 ). The bonded insole  14  and outsole  16  (with affixed pad  18 ) are then assembled with the upper  12  to form the shoe  10  according to the invention (step  126 ). The bonded insole  14  and outsole  16  with pad  18  are shown in FIGS. 6-7 (bottom view and side view thereof, respectively), collectively known as bonded insole/outsole  10 A. The base of bonded insole/outsole  10 A has molded-in grip formations  16   a , which is known in the art. One advantage of this embodiment of the method of making the shoe  10  according to the invention is that a component, e.g., upper  12 , of the shoe  10  can be made separately without waiting for other components (e.g., insole  14 , the outsole  16  or bonded insole/outsole  10 A) to be manufactured. In particular, components of the shoe  10  can be efficiently made without waiting for the completion of the affixing of the pad  18  to the cavity  28  of the outsole  16 . This embodiment of the method of manufacturing the shoe  10  according to the invention is particularly suitable when the upper  12  is pre-fabricated or separately made by an outside manufacturer, e.g., an original equipment manufacturer (OEM). 
     In the alternative, the upper sole  12 , the insole  14 , and the outsole  16  can be molded in a single step if simultaneous or pseudo-simultaneous manufacturing is desired, depending on manufacturing considerations or factory conditions. FIG. 8 is a flow diagram that illustrates another embodiment of the method for making the shoe  10  according to the invention. Elements of a shoe according to the invention (as shown in FIGS. 1-3) are also referred to herein in describing this embodiment of the method of the invention. Referring to FIG. 8, the upper  12 , the insole  14 , and the outsole  16  are separately provided in steps  131 ,  133 , and  135 , respectively. The cavity  28  is formed in the outsole  16  in step  137 . The cushioning pad  18  is permanently affixed in the cavity  28  in step  139 . After the pad  18  is affixed in the cavity  28 , the upper  12 , the insole  14 , and the outside  16  (with the affixed pad  18 ) are bonded together, in a simultaneous or pseudo-simultaneous fashion, to form the shoe  10  according to the invention using, e.g., injection molding which is commonly known in the art (step  138 ). This particular embodiment of the method of the invention is useful when, e.g., it is more cost-efficient to manufacture the upper  12 , the insole  14 , and the outsole  16  at a single factory location. 
     FIG. 9 is a flow diagram illustrating an embodiment of the molding process in making a shoe according to the invention. The embodied molding process of FIG. 9 is suitable for making a bonded insole/outsole  10 A (as shown in FIGS. 6-7) in an OEM production arrangement. Elements of a shoe according to the invention (as shown in FIGS. 1-3) are also referred to herein in describing this embodiment of the molding process of the invention. Referring to FIG. 9, a mold suitable for molding an insole  14  and outsole  16  into a bonded insole/outsole  10 A is provided in step  141 . A cushioning pad  18  is attached (by adhesion, stitching or other means) to the insole  14  in step  143 . The pad  18  (with attached insole  14 ) are placed in the mold for injection molding (step  145 ). After closing the mold, the molding internal for the outsole  16  is heated and then injected into the mold to form the outsole  16  and bond it with the insole  14  with the cushioning pad attached (step  147 ). That is, the insole  14  and the outsole  16  are molded in a single step. The mold is allowed to cool and the bonded insole/outsole  10 A is removed in step  149 , which is assembled with a pre-fabricated sole (e.g., provided by an OEM) to make the sole according to the invention. 
     FIG. 10 is a flow diagram illustrating another embodiment of the molding process in making a shoe according to the invention. The embodied molding process of FIG. 10 is suitable for molding the upper  12 , the insole  14 , and the outsole  16  in a single step. Elements of a shoe according to the invention (as shown in FIGS. 1-3) are also referred to herein in describing this embodiment of the molding process of the invention. Referring to FIG. 10, a mold suitable for molding the insole  14 , the upper  12 , and the outsole  16  is provided in step  151 . The insole  14  is attached with the material for the upper  12  by, e.g., adhesion or stitching, etc. (step  153 ). The cushioning pad  18 , the material for the upper  12  (with the insole  14  attached) are placed in the mold for injection molding (step  155 ). After closing the mold, the molding material for the outsole  16  is heated and then injected into the mold, so that the outsole  16  is formed encapsulating the pad  18  and securely bonded with the insole  14  and the upper  12  (step  157 ). The mold is allowed to cool and the finished shoe is removed in step  159 . The outsole  16  is formed, molded and bonded to the insole  14  and the upper  12 , as described herein, in a single molding step. 
     The molding apparatus suitable for the molding used in the various embodiments of the invention may be of any suitable type. Particularly preferred is injection molding which utilizes any suitably known injection molding apparatus, the construction and operation thereof are well known in the art. Alternative molding techniques may also be employed, depending on the nature of the molding material used. 
     In another embodiment of the invention, the cavity  28  is defined by a plurality of ribs  32  integrally formed on the peripheral wall  20  of the outsole. The cushioning pad  18  is placed in the cavity  28  which is defined by the ribs  32 . The peripheral wall  20  and bottom of the outsole are molded in a first stage. The pad  18  is made separately. The ribs  32  arc molded in a second stage. The pad  18  is permanently affixed by adhesion to the floor  30  in the cavity  28  and to the surrounding ribs after the ribs  32  are molded. The outsole  16  (with the affixed pad  18 ) are then bonded with the upper sole  12  and insole  14  to form the shoe  10  according to the invention. 
     In another embodiment of the invention, the cavity  28  is defined by a plurality of ribs  32  integrally formed on the peripheral wall  20  of the outsole. The cushioning pad  18  is placed in the cavity  28  which is defined by the ribs  32 . The peripheral wall  20  and bottom of the outsole are molded in a first stage. The pad  18  is made separately. The ribs  32  are molded in a second stage. The pad  18  is permanently affixed by adhesion to the floor  30  in the cavity  28  and to the surrounding ribs after the ribs  32  are molded. The outsole  16  (with the affixed pad  18 ) are then bonded with the upper  12  and insole  14  to form the shoe  10  according to the invention. 
     The inner periphery of cavity  28  and pad  18  are sized and shaped to correspond to one another, and to the contours of the peripheral wall  20  of outsole  16 . Pad  18  is typically made of EVA, although other resilient, flexible materials are possible as noted above. Pad  18  has an upper surface  36  that is juxtaposed with the insole  14  and an edge  38  that is positioned adjacent the periphery  34  of cavity  28  during assembly of shoe  10 . Heel  40  and toe  42  caps are provided to receive a corresponding heel  44  and toe  46  of the upper  12 , respectively, for facilitating the adhesive bonding of these structures together. Prior to assembly of the upper  12  and outsole  16 , as mentioned above, the pad  18  can be molded in place onto the floor  30  as follows. A preformed pad  18  is placed in cavity  28  then a layer  48  is applied of a conventional TPR material or one of the preferred materials mentioned above that adhesively bonds to the top  36  and edge  38  surfaces of the pad, acting further to mold these surfaces to the floor  30  and ribs  32  that comprise inner periphery  34  or cavity  28 . The pad  18  can also be molded by conventional injection molding, in a relatively simultaneous step along with the outsole  16 . 
     Referring to FIGS. 12-13, pad  18  extends between peripheral wails  20  and fills cavity  28 , whereas FIGS. 13-14 alternatively show ribs  32  being present in plantar region  22  such that the polymeric material of injection molded pad  18  is found within the comb structure between ribs  32 . Because the polymeric material of ribs  32  and outsole  16  can be the same or different than pad  18 , it is possible to have different regions of outsole  16  with differing densities. 
     Although the invention has been particularly shown and described in detail with reference to the preferred embodiments thereof, the embodiments are not intended to be exhaustive or to limit the invention to the precise forms disclosed herein. It will be understood by those skilled in the art that many modifications in form and detail may be made therein without departing form the spirit and scope of the invention. Similarly, any process steps described herein may be interchangeable with other steps in order to achieve the same result. All such modifications are intended to be encompassed within the scope of the invention, which is defined by the following claims and their equivalents.