Patent Publication Number: US-2018035745-A1

Title: Fastening device and kit, especially for interchangeable fashion footwear

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     
         
         This application claims priority to provisional Application No. 62/200,597 filed Aug. 3, 2015 and U.S. Design Pat. Application No. 29/535,091 filed Aug. 3, 2015, which are hereby incorporated by reference in its entirety. 
       
    
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     
         
         Not Applicable 
       
    
     MICROFICHE APPENDIX 
     
         
         Not Applicable 
       
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present inventive subject matter relates generally to a fashionable fastener and more specifically it relates to a sandal-type footwear structure comprising of an implanted fastener that allows for attachable, detachable and switchable components. 
     Description of the Related Art 
     In the apparel and fashion industry that overlaps each other, consumers continuously buy more styles of footwear, closely resembling fashion trends. This has led to inconveniences and inefficiencies in several ways since the differences between footwear styles may be categorized by their soles and within each category it is common that soles appear the same in comparison to the style variety of the upper, leading to individual consumers forced to buy multiple pairs of permanently attached soles that are basically identical, purely to obtain a wardrobe with multiple styles of uppers. Alternatively, modern consumers starving for more options may also want a certain style upper but on a different style sole. In addition to a greater variety of style options, consumers may want a seemingly tailored fit not offered with mass produced footwear with permanently attached uppers and soles, such as a smaller size upper than what would normally come with a sole. Footwear with fixed uppers and soles also establishes inefficiencies of manufacturing and distributing, as well as inconveniences of transporting luggage due to their redundancies and inflexibilities that constrict their ability to reduce material-cost, labor-cost, empty space, and product weight while also at least maintaining demanded capabilities. 
     A footwear structure comprising of a fastening device for switchable and attachable components could solve the problem of needing an entirely new shoe merely for a new upper or new sole. However, a structure must comprise of the essential features that mainstream consumers demand in order to be practical and useful within the fashion and apparel industry. There are opposing forces though that occurs when enhancing certain characteristics, increasing the difficulty to achieve the desired characteristics that have not been overcome prior to the present inventive subject matter. For example, when modifying a design to increase tensile strength, convenience and an attractive appearance could be unintentionally and unknowingly decreased. 
     There have been attempts made to offer a footwear structure that enables consumers to interchange uppers. Some use a crude hook and loop structure, such as U.S. Pat. No. 2,368,314, U.S. Pat. No. 6,418,643, U.S. Pat. No. 8,250,780, U.S. Pat. No. 8,661,715. However, these structures are incapable of being convenient and secure. For example, U.S. Pat. No. 6,418,643, requires the user to remove the upper to switch an upper. 
     Many attempts use a fiddly tee shaped hook and socket structure, such as, U.S. application Ser. No. 11/433,495, U.S. Pat. No. 7,650,704, U.S. Pat. No. 7,950,704, U.S. Pat. No. 7,954,260, U.S. Pat. No. 8,819,964 and U.S. Pat. No. 8,938,891. However, these structures are not intuitive and the concept of having to screw a pair of shoes together is not appealing to female consumers. The attributes of this type of mechanism limit it to cheap flip-flop-type sandals. 
     Others even utilize a common snap button structure, such as, U.S. Pat. No. 3,925,915, U.S. Pat. No. 4,887,369, U.S. Pat. No. 5,992,058, and U.S. Pat. No. 7,661,206. However, these mechanisms are intended for footwear with a thick platform and appear tasteless on the side of a sandal. These structures are also incapable of firmly and comfortably securing the users foot within a shoe. 
     Attempts have even been made to create a clip-like structure, but these structures also lack crucial features desired by modern consumers. Two of the structures, U.S. Pat. No. 5,896,684 and U.S. Pat. No. 6,442,870 requires tools or several steps that make them complicated to use. Another two structures, U.S. Pat. No. 6,349,486 and U.S. Pat. No. 6,351,897, resemble a buckle for a car seat that lack visual appeal on fashion footwear. A few more structures, U.S. Pat. No. 6,490,846, U.S. Pat. No. 6,640,373, U.S. application Ser. No. 10/707,995, U.S. application Ser. No. 10/793,260, and U.S. application Ser. No. 13/541,963, comprises a structure that requires the fasteners to be placed within a mold prior to an injection forming process that involves injecting foaming raw material into the mold to form the sole component and encasing the fasteners. However, during the injection forming process the foaming raw material leaks into the moving components of the socket and causes the fasteners to become inoperable regardless of the preventative measures stated. Moreover, these designs do not comprise of a socket base that enables a secure implantation sandwiched between sturdy layers. In other words, they do not state a method to securely implant a fastening device that can be manufactured economically without a large percentage of defects. Moreover, these mechanisms lack a decorative design and an actuator that enables a low-profile face to make the fastener attractive, user-friendly, and reliable. Therefore, they are encased and hidden within the side wall of the footwear, making the fasteners harder to intentionally disengage and manufacture. Moreover, a shoe made with flowable resin that cures soft enough to press a button covered by said soft cured resin is only really used for non-fashion sandals such as hiking-type sandals. They also lack several other features that permit a thin mechanism efficiently and reliably implanted between the insole and outsole of a shoe, such as proper tensile strength regardless of the direction an attached upper component is pulled. Specifically, U.S. Pat. No. 6,490,846, U.S. Pat. No. 6,640,373 comprises a tight shaft that restricts a pushbutton from traversing in any direction besides directly horizontally and therefore requires that the pushbutton to be a separate component that slides at the point where the inner tip of pushbutton and pawl touch. Additionally, U.S. Pat. No. 6,640,373, U.S. application Ser. No. 10/707,995, U.S. application Ser. No. 10/793,260, and U.S. application Ser. No. 13/541,963 comprise of a hinge that is only flexible at a concentrated point where the thick pawl abruptly tapers off and meets the innermost socket wall, decreasing flexibility, usability, durability, and reliability. This design also requires a substantially deep socket shaft and protruding pushbutton to compensate for how hard the pushbutton is to push and for how easy the plug can unintentionally slip out when an upper is pulled at an angle when the user moderately twist their ankle and when the user stops running suddenly. This design also limits their use in high wedge sandals and especially for flat-type sandals that often have midsoles that are less than 8 mm thick from top to bottom. The unintended release of the plug and upper is most caused be the thick pawl that is pushed into the disengaged position by the plug during use, resulting in an especially hazardous situation when the unexpected release occurs when the user is stepping down a staircase. Another reason why these structures fail is that even with a deep socket shaft these structures allow the plug to twist when the user is wearing the footwear structure and performs a quick stopping action because the width of the structure from the side closest the toe of the shoe to the side closest the back of the heel of the shoe. This twisting action allow for the plug to unintentionally slip out because a higher tooth on the plug is able to ply a lower tooth of the pawl backwards, which pries back the pawl into the disengaged position. Additionally, these last few structures comprise of a pushbutton that travels horizontally through an outmost socket wall and protrude outwards from the outermost socket wall, which is undesirable on the side of fashion footwear, especially when it involves increasing the width of a shoe to conceal a protruding pushbutton because fashion footwear is preferably as narrow as practicably. 
     With many unsuccessful interchangeable shoes in the apparel industry, it has become obvious that the only consumers that are going to want a shoe that can be interchanged between styles are those who are devoted to fashion. In other words, who would want and buy a shoe to switch styles, if they are not concerned with style? Another factor that is important is most consumers would are concerned with fashion also demand convenience. Additionally, nobody really wants a shoe that is unreliable or wears out quickly. These key circumstance has been a barrier to a useful interchangeable shoe because nobody has been able to invent a shoe that comprising of the most important features. In order for an interchangeable shoe to be successful in the apparel industry, it has to be practical for a variety of uses, with a variety of fashionable, switchable, and firmly attachable upper components and sole components that are economically manufactured, easy-to-use, strong enough to resist unintended detachment under extreme use, and actually consistent with the modern fashion industry. Therefore, there is still a need for a footwear structure that is capable of the important features found in popular footwear, such as usability, attractability, reliability, durability, variability, comfortability, packability, producibility, and conveyability 
     BRIEF SUMMARY OF THE INVENTION 
     With the onset of rapid influences on the apparel industry by the fashion industry there is a substantial demand for an increased variety of quality footwear that is accessible with increased efficiency. Consequently, the present inventive subject matter provides genuine fashion footwear with switchable upper components and sole components that enable consumers to have an increased variety of styles without sacrificing other crucial features of successful footwear on the market and therefore, provides an improved apparatus with unprecedented features. 
     The fastening device has socket securely implanted between one or more prefabricated layers forming the sole component and a plug attached to the upper component. Therefore, an upper component of the footwear is securely attached to a sole component and upper component and sole components may be conveniently switched out for a variety of styles, colors, and sizes and be securely attached for extreme usage. 
     The fastening device comprises of a locking, stabilizing, and actuating mechanism that locks and stabilizes the plug within a socket shaft of a socket. By using several features, a fastening device may be disengaged by lightly pulling down on a stabilizing lever, yet have sufficient tensile strength to hold up during extreme usage. The features of the socket include a pawl, socket shaft, stabilizing lever, flexible joint, aperture, aligning tabs, anchor, and flanges. The features of the plug include at least one prong with complementary teeth to the pawl and overhangs. 
     The locking, stabilizing, and actuating mechanism implements (a) a pawl capable of pinching a plug tighter against a socket shaft when tension is applied and immobilized once the plug is sufficiently pinched, (b) a recessed stabilizing lever that is pushed downwards within an aperture to intentionally disengage the fastening device and also stabilizes a flexible joint when immobilized at an aperture roof, (c) a flexible joint that is stabilized so that it can be sufficiently flexible and also prevents a pawl from being pushed into a disengaged position, (d) overhangs to prevent the plug from twisting out, which are immobilized by aligning tabs, (e) aligning tabs that insure the socket shaft is aligned with slits in a sturdy insole, (f) a sturdy insole to properly hold down sockets, (g) a rectangular shaped anchor that increases the surface area of the socket underneath the insole, (h) flanges held down by a midsole that also allow the insole, midsole, and outsole to be bonded firmly at each side of the socket face to reinforce a sturdy attachment of a socket, and (i) a concave face with a flat perimeter so that the socket face may be fashionable exposed for unobstructed access to actuate the stabilizing lever. 
     Certain aspects of the inventive subject matter provide a stabilizing lever that conveniently disengages the fastening device by allowing the flexible joint to be extremely flexible. Another feature of the actuating mechanism is how the lever pivots mostly in a downwards motion so that the lever may be recessed as opposed to protruding out in an unsightly fashion. The lever also has a slanted face so that it indicated and assist in a downwards motion. Also, with a stabilizing lever that extends into an aperture (large enough for a fingertip) in the socket without needing to protrude out past a socket face, a concave shaped socket face may be exposed for unobstructed access to the stabilizing lever that is used to intentionally disengage the fastening device 
     Certain aspects of the inventive subject matter provide a socket face that may be flush with the side of the shoe at the perimeter by comprising of a slightly concave section toward the center to avoid being scratched during manufacturing, 
     Certain aspects of the inventive subject matter provide a flexible hinge jutting out horizontally that prevents a pawl from being pushed back because a horizontal flexible lever is not flexible directly backwards within the geometric plane that it is located in. This feature is important because if the pawl was able to be pushed back, the upper could pop out during a slight rolling of the user&#39;s ankle and result in a broken ankle if the shoe is a wedge-type sandal. 
     Certain aspects of the inventive subject matter provide overhangs on each side of the plug that prevent the plug from being twisted within a short and wide socket shaft. 
     Certain aspects of the inventive subject matter provide a method for manufacturing footwear, the method comprising: (a) providing an improved socket; (b) providing two or more sole component layers, an outsole, midsole, and insole, wherein the insole and outsole may be a single piece or the midsole and insole may be a single piece; (c) providing a midsole or top layer midsole with a cavity tightly shaped for the socket; (d) inserting and attaching the socket into the cavity of the midsole, wherein aligning tabs align the socket shaft to the slits in the insole; (e) bonding the layers of the sole component together; and (f) sanding the vertical sides of the shoe and socket face to make the socket flush or covering the socket face with a thin flexible wrap with a rubber buffer to intentionally disengage the system easily. 
     It is therefore an object of the present inventive subject matter to provide an apparatus that may be manufactured using methods that significantly reduces the possibility of unsustainable amounts of defective products being produced. Especially by eliminating the chance of flowable resin seeping into the mechanical interworking of the apparatus. 
     It is a further object of the present inventive subject matter to provide an apparatus that overcomes the problems associated with the apparatus being complicated or requiring physical strength to intentionally disengage. 
     It is another object of the present inventive subject matter to provide a structure that is consistent with current fashion trends of mid to high-end footwear. Specifically, to present a footwear structure that is thin between the ground and foot, so that the apparatus immediately “clicks-in” when attaching and so that the accessible socket face has a streamlined appearance. 
     It is an additional object of the present inventive subject matter to provide an apparatus that is user-friendly with a sleek appearance that also has a sufficient tensile strength pulled straight apart or at any angle possible when a person is wearing a shoe and capable to be used in footwear such as high wedges and high platforms wherein the possibility of a sprained ankle is greater. 
     It is yet another object of the present inventive subject matter to provide a structure and kit that vastly increases the ability to economically obtain different fashionable styles with different combinations of upper components as well as with a variety of sole components that vary in color, angle of insole from toe to heel section, and overall height from the ground. 
     It is still one more object of the present inventive subject matter to provide a structure and kit that gives the ability to affordably create a tailored fit by offering different combinations of sizes between the upper component and sole component. 
     Certain aspects of the inventive subject matter also provide a structure and kit for mixing and matching upper components to a sole component to quickly acquire a large wardrobe of shoes. 
     Additionally, and on the other hand, certain aspects of the inventive subject matter also provide a kit for by mixing and matching a collection of sole components to a complementary upper component to multiple the number of styles they can wear an upper component. 
     Certain aspects of the inventive subject matter also provide a structure and kit for consumers of fashion products to wear an equivalent amount or more styles while reducing: environmental impact, material-cost and labor-cost during manufacturing, empty space and weight during shipping and storing, money spent shopping on multiple styles of footwear, frustration dressing up for an occasion, and exhaustion when traveling with luggage. 
     In view of the foregoing, an object of the present inventive subject matter is to provide a footwear apparatus comprising of a modern, uncomplicated, effortless, and reliable fastening device that may be used for convenient and secure attachment of component parts, such as switchable upper component, as well as switchable sole components of various fashion designs and combinations of sizes. 
     Therefore, the present inventive subject matter improves efficiency and possibilities in the apparel/fashion industry. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded view of the sole. From top to bottom: insole, midsole, outer socket, inner socket, and outsole with heel. 
         FIGS. 2A and 2B .  FIG. 2A  illustrates how the layers come together in  FIG. 1  to form a finished sole.  FIG. 2B , the sole component from above, depicts the thin slots that the plug goes through to engage with the socket. 
         FIG. 3 , the midsole from above, depicts how the midsole over laps the flanges when comparing the lower view point in  FIG. 1   
         FIGS. 4A and 4B .  FIG. 4A  is a plane of the socket from above.  FIG. 4B  is a plane of the socket from below. 
         FIGS. 5A, 5B, 5C, and 5D .  FIG. 5A  is the plug and the socket from the side.  FIG. 6B  is a frontal view of the plug and socket.  FIG. 5C  is a rear view of the plug and socket.  FIG. 5D  is a cross-sectional view of the plug and socket in  FIG. 5B  through line  5 D- 5 D shown in the uncoupled position. 
         FIG. 6  is a view of the plug and plug teeth. 
         FIG. 7  is a view of the plug and socket engaged. 
         FIG. 8  is a view of the plug inserted in the socket in the disengaged position. 
         FIG. 9  is a perspective view of a sole component and a detached upper component that may be assembled into a shoe by means of two or more coupling devices of the present inventive subject matter comprising of sockets and plugs. 
         FIG. 10  is a perspective view of a slide-type sole component and an attached low ankle strap upper component. 
         FIG. 11  is a perspective view of a slide-type sole component and an attached cuff upper component. 
         FIG. 12  is a perspective view of a slide-type sole component and an attached single wraparound gladiator-type upper component. 
         FIG. 13  is a perspective view of a thong-type sole component designed for a thong-type upper component and an attached thong upper component. 
     
    
    
     A wedge-type sole component is not shown. 
     A shoe comprising of a flexible wrap covering a socket face is not shown 
     DETAILED DESCRIPTION AND BEST MODE OF IMPLEMENTATION 
     Let it be noted that the disclosure of the inventive subject matter in this specification includes all possible combinations of such features. 
     An, “upper component”  40  refers to an upper of a shoe or footwear, and can include a toecap part (not shown), a toecap patch (not shown), a toe box  42  strap that covers the forward part of a person&#39;s foot, ankle-type upper  43 , cuff upper  44 , wraparound gladiator upper  45 , thong-type upper  46 , and heel straps (not shown), and can include unitary and integral combinations as well. 
     A, “sole component”  1  refers to the component attached to the upper component  40  to form an interchangeable shoe  41 . A sole component  1  is not to be confused with an outsole  4  layer. Additionally, sole components  1  may comprise of an outsole  4  that is a flat-type outsole (seen in  FIG. 1 ), wedge-type outsole (not shown), or high platform-type outsole (not shown). 
     A, “horizontal” refers to a normal positioned interchangeable shoe  41 . For example with the sole component  1  resting on a horizontal surface. An, “outer” and “inner” refer to elements of the fastening device  38  positioned nearer and further away, respectively, from the nearest lateral side of the sole component  1 . 
     A fastening device  38 , according to an embodiment of the inventive subject matter comprises two parts: a socket  5  and a plug  26 . The socket  5  is typically embedded into a sole component  1 , while the plug  26  is typically affixed to the upper component  40 . 
     The socket  5  includes a socket shaft  15  that is adapted to receive the plug  26 , a pawl  17  for engaging and locking the plug  26  with the socket  5 , and stabilizing lever  18  for releasing the pawl  17  from the plug  26 , whereby the upper component  40  may be detached from the sole component  1 . The pawl  17  is connected to a flexible joint  16  at the top side of the socket shaft  15  and preferably forms a right angle where the pawl  17  and flexible joint  16  integrally meet as one piece. The flexible joint  16  is preferably connected at the top side of the center socket wall  22 . The pawl  17  comprises an upper component  40  portion and a lower portion having a surface facing the outer wall, the surface preferably having two toothed surfaces, each comprising at least one tooth, astride a middle portion where the stabilizer lever  18  is attached. The socket  5  may be manufactured in one piece. The plug  26  may be manufactured in one piece. 
     In a preferred embodiment, the plug  26  has two spaced-apart toothed prongs  30 . The plug teeth  33  are complimentary to the teeth on the pawl  17 . The release means, preferably a stabilizing lever  18 , extends through an aperture in the outermost socket wall  20  with an exterior socket face  27 . The stabilizing lever  18  communicates with the pawl  17  by being directly attached as one molded piece. The stabilizing lever  18  traverses the aperture  19  in mostly an up and down motion. Within the socket  5 , the stabilizing lever  18  preferably passes between the pair of toothed prongs  30 , and preferably between the highest teeth, to communicate the downward force of a person&#39;s finger pressing mostly downwards. The applied pressure on the stabilizing lever  18  displaces the pawl  17  away from the plug  26  sufficiently to separate the complementary engaged teeth of the pawl  17  and the prongs  30 , thereby disengaging and releasing the plug  26 . The aperture  19  is sized so that a person&#39;s finger can access the stabilizing lever  18 . The stabilizing lever  18  is preferably recessed within the socket face perimeter  28  and the sole component  1  to avoid scratching the stabilizing lever face  21  when a sole component side  12  is sanded and smoothed during manufacturing. An interchangeable shoe  41  with a recessed stabilizing lever  18  may generally go unnoticed by a casual observer, yet it may be easier to manipulate by simply pressing downwards by a person&#39;s finger. If the socket face  27  was covered by a less flexible layer that also holds the socket  5  in place, the fastening device  38  could be hard to operate. The socket  5  is rectangular in shape comprising of a front rectangular socket shaft  15  sharing a center socket wall  22  with an anchor  7 . The anchor  7  has a thin layer across the bottom to increase the surface area for adhesive and has protruding thin solid rectangles flanges  8  along the bottom of the side socket walls  24  to restrain the coupling device underneath the midsole  3 , reinforcing the attachment of the socket  5 . Nylon is preferably used to mold a fastening device  38  with sufficient tensile strength, which is determined to be greater than 250 Newton for each fastening device  38  implanted within a interchangeable shoe  41  such that the fastening device  38  does not pull out of a sole component  1  and a plug  26  does not pull out of a socket  5  at any angle possible when a interchangeable shoe  41  is in use. 
     The sole component  1  (outsole  4 , midsole  3 , and insole  2 ) is generally created using traditional techniques, such as cutting out and molding or modern techniques, such as additive manufacturing (AM), subtractive manufacturing, and automated overmolding (to reduce labor and shipping cost and increase markets) with materials including but not limited to leathers, Ethylene vinyl acetate, polyurethanes, thermoplastic rubber, Poly-Vinyl Chloride, and metals; methods for this technique are well known in their fields of art. The sole component  1  preferably has at least three layers, unless only two layers are needed when the midsole  3  and insole  2  are formed as one-piece because the socket  5  has to be installed between the outsole  4  and the midsole  3  or unless only one hard layer is needed when a socket  5  is snapped in from above and a soft footbed is installed for aesthetics and cushion. When the style permits, the insole  2  could be molded as one-piece with the midsole  3  to hold down the flanges  8 , strengthening the fastening of the socket  5  and reducing manufacturing steps. Layers are attached using adhesive or snaps when applicable. AM would consist of numerous layers and the insertion of the socket  5  by a robotic arm after layer is formed that the socket  5  rest on is preferred. Utilizing a coupling device described above with AM would allow for various types of upper components  40  to be implemented on seamless three-dimensional midsole  3  designs not easily created by other means, thus increasing comfort and design possibilities of interchangeable shoes  41  manufactured using AM. 
     In a preferred embodiment, there are three layers for the sole component  1  (the outsole  4 , midsole  3 , and insole) plus at least one layers for a heal. The outsole  4  layer underneath the socket  5  is preferred to be a three millimeters thick continuous layer of leather, or rubber, all the way across from front to back and side to side to increase strength. The midsole  3  layer begins at a forward point in the sole component  1  and gradually become as thick as the height of the socket  5  and is preferably made of EVA or similar material. The midsole  3  has two cavities on each side with the inverse geometry of the socket  5  so that when the socket  5  is inserted tightly into the cavities of the midsole  3 , the socket face  27  is flush with the side of the midsole  3 . Cavities in the midsole  3  for the flanges  8  would allow for the midsole  3  to be over the flanges  8  and hold them down to secure the attachment of the socket  5 . Leather and rubber interchangeable shoes  41  may be buffed and consist of a socket  5  with a perimeter that is flush with sole component side  12 , but the face would start to become slightly concave inside of the perimeter so that the face would not get scratched when the side of the sole component  1  is smoothed and buffed during manufacturing. The socket face  27  and sole component side  12  slant inwards from top to bottom for a more feminine appearance. The insole  2  has a continuous and sturdy layer across the tops of the socket  5  to increase the immovability of the socket  5 . There are slits  11  in the insole  2  for the plug  26  to attach to the socket  5 . Permanent front uppers or the figure in the thong-style is attached using adhesive. The switchable upper components  40  are preferably attached to the plug  26  by traditional techniques, such as sewing and using adhesive, or overmolding may be used with certain materials by implementing a ring design to the upper component  40  since the plug  26  does not have orifices where flowable resin would seep into. For the front attachment of thong-type upper components  40 , a conventional buckle  48  or button is preferred attached to the interchangeable shoe  41  finger  47  that runs between to a person&#39;s toes. 
     Construction and Operation: 
       FIG. 1  shows an exploded view of the inventive subject matter of a sole component  1  of the interchangeable shoe  41 , such as a woman&#39;s flat sandal, comprising the layers that are bonded together using adhesive. The sole component  1  has an insole  2 , midsole  3 , outsole  4  and two sockets  5  that are implanted between the layers of the sole component  1 . A view of the midsole bottom side  6  depicts how the socket  5 , comprising of an anchor  7  and flange  8 , is implanted within the midsole  3  flange cavities  9 . A view of the insole bottom side  10  depicts the insole slits  11  that are lined up with the two sockets  5 . 
       FIG. 2A  illustrates the layers together that were exploded in  FIG. 1  to form a finished sole component  1 . 
       FIG. 2B , the sole component  1  from above and from the perspective of looking down, depicts the continuous insole top surface  13  and the thin slits  11  that the plug  26  goes through to engage with the socket  5 . Both these figures most importantly show how the preferably three millimeter thick insole  2  securely hold down the socket  5  and how a socket  5  exposed from the side for easy operation can have a low profile look by being flush with the sole component side  12 . 
       FIG. 3 , the midsole  3  from above, depicts how the midsole  3  overlaps the flanges  8  of the socket  5 . 
       FIG. 4A  is a plane view of the socket  5  seen from the top and depicts the socket top surface  14 . The socket  5  has a socket shaft  15  and a flexible joint  16  level with the top surface  14  that is stabilized by the sturdy insole  2  that is secure across and above the flexible joint  16 . The socket shaft  15  is generally oriented parallel to the nearest lateral sole component side  12 . The pawl  17  communicates with the stabilizing lever  18  through an aperture  19  (see  FIG. 5B ) in the outermost socket wall  20  of the socket  5 . The stabilizing lever face  21  is positioned proximate inside of the outermost socket wall  20 , as shown by the cut-away portion of the socket  5  of  FIG. 6 . This view also depicts the center socket wall  22 , innermost socket wall  23  forming the anchor  7 , and the two side socket walls  24 . 
       FIG. 4B  is a plane of the socket  5  seen from below that shows the opening of the socket shaft  15  at the bottom so that the socket  5  may be molded as one piece. The thin layer across the anchor bottom  25  for adhesive is also seen. 
       FIG. 5A , the plug  26  and the socket  5  from the side. The plug  26  is molded as one continuous piece and has generally a flat shape. The socket  5  is molded as one continuous piece and has a generally rectangular shape. The material may be selected from materials including but not limited to plastics, metal, and rubber. This view also shows how the socket face  27  is flat at the socket face perimeter  28  and concave towards its center. 
       FIG. 5B , is a frontal view of the plug  26  and socket  5  that shows the Aperture  19  through the outermost socket wall  20  and the stabilizing lever face  21 . The narrow gap between the stabilizer lever  18  and aperture roof  29  enables the locking mechanism to lock and also prevents the flexible joint  16  from overextending and failing once the stabilizing lever  18  is pulled against the aperture roof  29 . This view also depicts the two prongs  30  and two overhangs  31  on the plug  26 . On the socket  5 , the two aligning tabs  32  are seen. The dash line between the overhang  31  and aligning tab  32  show how the Plug  26  is inserted into the socket  5 . This figure clearly shows the overhangs  31  on each side of the plug  26  that prevent the plug  26  from tilting further into the socket  5  such that one prong  30  would be further in the socket  5  than the other prong  30 , which could force the teeth  33  apart. 
       FIG. 5C  is a rear view of the plug  26  and socket  5  that depicts the plug teeth  33 . 
       FIG. 5D  is a cross-sectional view of the plug  26  and socket  5  in  FIG. 5B  through line  5 D- 5 D shown. This figure depicts the dimensions of an upper component  40  pawl tooth  34  and lower pawl tooth  35 , as well as a complementary upper component  40  plug tooth  36  and lower plug tooth  37 . This figure also shows how the stabilizing lever  21  is within the perimeter of the socket face  27 . In this view, the length and thinness of the horizontal flexible joint  16  flush with the top of the socket  5  is seen, as well as the pawl  17  connected to the both the flexible joint  16  and stabilizer lever  18 . Furthermore, this view depicts the kink  38  of the plug  26  that positions the upper component  40  to attach closer to the sole component side  12 , which allows the sole component  1  to have a thin fashionable appearance. 
       FIG. 6  is a view of the plug  26  from the left side at a slight angle clearly showing the teeth  33 . 
       FIG. 7  depicts the fastening device  38  wherein the plug  26  inserted and engaged with the socket  5 . In this view, the prong  30  is straddling the stabilizing lever  18 . This view also depicts how the flexible joint  16  cannot flex between the prong  30  and center socket wall  22  and therefore prevents the pawl  17  from being forced open by the prongs  30 . This figure further shows how there is space between the top of the prong  30  and top of the pawl  17 , so that when engaged, the plug  26  is further prevented from pushing the pawl  17  into a disengaged position when the plug  26  is pulled towards the center of the sole, which occurs when a user moderately and naturally twist their ankle. 
       FIG. 8  shows the fastening device  38  wherein the plug  26  is inserted and in the disengaged position that occurs when a person&#39;s finger pulls down on the stabilizer lever  18 . This view depicts how the stabilizing lever face  21  moves downwards and stays within reach of a person&#39;s finger when disengaging the fastening device  38 . 
       FIG. 9  is a view of a sole component  1  and a detached upper component  40  that may be assembled into a interchangeable shoe  41  by means of two coupling devices of the present inventive subject matter. This view also depicts how a plug  26  goes through slits  11  in the insole  2  and engages with the sockets  5 . A like number of plugs  26  are attached to the upper component  40  bottom edge  39 . Each socket  5  comprises a pawl  17  to engage with its corresponding plug  26 . 
       FIG. 10  is a view of a sole component  1  and an attached upper component  40 . Specifically, this view depicts an assembled interchangeable shoe  41  wherein the interchangeable shoe  41  is compatible with an upper component  40  that is a low ankle-type upper component  40   43  securely attached to a slide-type sole component  49  comprising a toe box  42 . In this view the fastening device  38  is seen flush and fashionable with the sole component side  12 . 
       FIG. 11  is a view of an assembled interchangeable shoe  41  wherein the attached upper component  40  is cuff upper component  44 . 
       FIG. 12  is a view of an assembled interchangeable shoe  41  wherein the attached upper component  40  is a wraparound gladiator upper component  45 . 
       FIG. 13  is a view of a sole component  1  and an attached upper component  40 . Specifically, this view depicts an assembled interchangeable shoe  41  wherein the interchangeable shoe  41  is compatible with an upper component  40  that is a thong-type upper component  46  securely attached to a thong-type sole component  50  comprising a finger  47  comprising a conventional buckle  48 . 
     Manufacture: 
     Molding Plastic and metal fasteners is well known in the industry. Preferably, the fastening device  38  is molded using a class one production mold for the intricate features. 
     The midsole  3  may be molded to insure proper dimensions; however other additive and subtractive manufacturing techniques may also be utilized. The insole  2  and outsole  4  may be cutout using a die, techniques are well known in the art. When the insole  2  is cutout, the slits  11  that the plugs  26  will go through to attach an upper component  40  may be cutout at the same time with a die that cuts out the insole  2 . The midsole  3  is approximately the same height as the socket  5  and it is preferred that the midsole  3  and socket  5  be less than eight millimeters from bottom to top excluding the aligning tabs  32 . It is preferred that the aligning tabs  32  protrude two to three millimeters up from the socket  5 . The socket  5  is preferably implanted in the midsole  3  and then the midsole  3  comprising at least one socket  5  lined up to the slits  11  within the insole  4  using the aligning tabs  32  to insure the socket shaft  15  is unobstructed such that the plug  26  slides into the socket shaft  15  smoothly. Once the adhesive is heated and dried the sole component sides  12  are smoothed with a sander and buffer with wax preferably so that the socket face  27  and midsole  3  is flush with the outsole  4  and insole  2 . The buffering gives the leather a more high-end look. The socket face perimeter  28  may be extended out (not shown) from the socket face  27  approximately one millimeter to avoid grinding down the concave portion of the socket face  27 . By extending the socket face perimeter  28 , a rubber buffer with a bulge (not shown), to squeeze between the top of the stabilizer lever  18  and aperture  19 , may be placed between the socket face  27  and a thin flexible wrap (not shown) to conceal the socket face  27  without decreasing the easy user-ability experienced with an exposed socket face  27 . It is preferred that the material to mold the midsole  3  is a light firm material such as Ethylene vinyl acetate (EVA) or polyurethane. Multiple additional layers of leather or leather-like material may also be used for the midsole  3 , but the advanced EVA materials reduce weight and give the interchangeable shoe  41  more cushion and flexibility without compromising how the socket  5  is impeded securely. The toe box  42  and finger  47  may be attached to the sole component  1  using conventional methods. The plug  26  may be attached to an upper component  40  by sewing and applying adhesive. Other methods include overmolding rubber upper components  40  to modified plugs (not shown).