Patent Abstract:
A method of making a shoe comprises sewing a rear stitching margin of a rear section of an upper to a midsole, gluing and attaching a rear section of an outsole to the midsole and the rear stitching margin, and stitching a front stitching margin of a front section of the upper directly to a front section of the outsole. The method is simple since it dispenses with use of a heel lasting machine which requires complicated processing steps. The method provides a shoe with good flexibility at a front section of the shoe and sufficient support at a rear section of the shoe.

Full Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a method of making a shoe, more particularly, a method in which a front portion of an upper is stitched directly to an outsole and a rear portion of the upper is sewn to a midsole. 
     2. Description of the Related Art 
     A typical shoe construction, well known as the Opanka construction, includes an upper having a bottom open end stitched directly to the periphery of an outsole without any midsole attached to the upper. While such a shoe construction provides good flexibility, due to the absence of the midsole, it does not have sufficient strength at its heel region so that it can be deformed easily, especially when the user who wears the shoe takes part in dynamic activities. 
     In order to alleviate the aforesaid problem, an improved method of constructing a shoe is suggested in U.S. Pat. No. 6,029,301. The method includes stitching the bottom end of a front portion of an upper to the outer peripheral end of a front portion of an outsole through pre-punched needle holes provided in the front portions of the upper and the outsole, and lasting the bottom end of a rear portion of the upper to a midsole by means of a heel lasting machine followed by the step of securing the midsole to the outsole. The shoe constructed by this method not only provides enhanced strength at the heel region to alleviate the deformation problem but also possesses good flexibility. However, inconveniences are caused due to the use of the heel lasting machine. In addition, since the upper is made of a flexible material, the heel lasting machine would deform the front portion of the upper and would cause misalignment of the pre-punched needle holes in the upper and the outsole if the front portion of the upper is stitched to the outsole after the rear portion is lasted. To avoid the misalignment problem, the stitching operation is carried out prior to the lasting operation by using a complicated hinged last which has a stationary front section and a movable heel section. The use of such a hinged last complicates the method of constructing the shoe. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to provide a simple method of making a shoe which eliminates the problem encountered in the prior art disclosed in the above-mentioned U.S. Patent. 
     According to the present invention, a method of making a shoe, comprises: (a) preparing an upper which includes an open top end, an open bottom end, an enclosing wall extending from the top end to the bottom end, the enclosing wall having a front section and a rear section, the front section having a front stitching margin, the rear section having a rear stitching margin; (b) preparing an outsole having a front section and a rear section; (c) preparing a midsole including at least a heel section; (d) stitching the rear stitching margin to the midsole; (e) inserting a last into the upper; (f) gluing and attaching the rear section of the outsole to the rear stitching margin and the midsole; and (g) stitching the front stitching margin to the front section of the outsole. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiments of the invention, with reference to the accompanying drawings, in which: 
     FIG. 1 is a perspective view illustrating an upper, a midsole and an outsole to be assembled in a first preferred embodiment of a method of making a shoe according to the present invention; 
     FIG. 2 is a perspective view of a shoe produced by the first embodiment; 
     FIG. 3 is a perspective view showing that the midsole is sewn to the upper; 
     FIG. 4 is a sectional view taken along line  4 — 4  of FIG. 2; 
     FIG. 5 is a sectional view taken along line  5 — 5  of FIG. 2; 
     FIG. 6 is a perspective view illustrating an upper, a midsole and an outsole to be assembled in a second preferred embodiment of the present invention; 
     FIG. 7 is a sectional view of a shoe produced by the second embodiment; 
     FIG. 8 is another sectional view of the shoe of FIG. 7; 
     FIG. 9 is a perspective view illustrating an upper, a midsole and an outsole to be assembled in a third preferred embodiment of the present invention; and 
     FIG. 10 is a perspective view of a shoe produced by the third preferred embodiment. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Before the present invention is described in greater detail, it should be noted that same reference numerals have been used to denote like elements throughout the specification. 
     The first preferred embodiment of a method according to the present invention includes preparing an upper  1 , a midsole  2  and an outsole  3  which are shown in FIG.  1 . 
     The upper  1  is made of a soft and comfortable material such as leather or a fabric, and includes an enclosing wall  10  extending from an open top end  102  to an open bottom end  103  of the upper  1 . The enclosing wall  10  includes a front section  11  which covers a toe region  111  and a metatarsal region  112 , and a rear section  12  which covers a heel region. The front section  11  has a front stitching margin  113  that extends from the left side of the metatarsal region  112  to the right side of the metatarsal region  112  and around the toe region  111 . A series of needle holes  114  are provided in the front stitching margin  113  through a punching process. 
     The midsole  2  is formed as a midsole half which has a heel region  21  and a front edge  22  which will extend at the rear of the metatarsal region  112  after the midsole  2  is assembled with the upper  1 . While the midsole half  2  is used in this embodiment, it may be substituted with a full length midsole that has heel, metatarsal and toe regions. 
     The outsole  3  has a front section  31  corresponding to the front section  11  of the upper  1  and a rear section  32  corresponding to the rear section  12  of the upper  1 . The front section  31  is provided with a plurality of needle holes  311  in a front peripheral upward flange  312 . The positions of the needle holes  311  correspond respectively to the needle holes  114  in the front stitching margin  113 . Each needle hole  311  extends from the upper side of the peripheral upward flange  312  to the lower side thereof, as shown in FIG. 5. A rear peripheral flange  321  projects upward from the outer periphery of the rear section  32 . 
     The method of this embodiment provides a shoe shown in FIG. 2 by assembling the upper  1 , the midsole  2  and the outsole  3 . In assembly, the midsole  2  is first sewn to the rear stitching margin  121  of the rear section  12  of the upper  1  along a stitching line A which extends along full length of the rear stitching margin  121 . The stitching line A extends from the front edge  22  at the left side of the midsole  2  to the front edge  22  at the right side and around the heel region  21  as shown in FIG.  3 . The front edge  22  of the midsole  2  extends rearwardly of the metatarsal region  112  of the upper  1 . 
     After the midsole  2  is sewn to the rear section  12  of the upper  1 , a last  5  is inserted into the upper  1 , as shown in FIG. 4, and the rear section  32  of the outsole  3  is secured to the midsole  2  and the rear stitching margin  121  of the upper  1  through a gluing process. Subsequently, the front stitching margin  113  of the front section  11  of the upper  1  is turned outward and is stitched to the front section  31  of the outsole  3  by using a thread  4  which passes through the needle holes  114  and  311 , as shown in FIG.  5 . 
     As described above, the present invention does not utilize a heel lasting machine which is necessary in the prior art disclosed in U.S. Pat. No. 6,029,301. Instead, the present invention employs a stitching process to secure the midsole  2  to the rear section  12  of the upper  1 , which permits the entire open bottom end  103  of the upper  1  to be positioned properly through a stitching machine during the stitching process. As such, no deformation problem occurs in the front section  11  of the upper  1  after the midsole  2  is sewn to the upper  1 , and the needle holes  114  in the front section  11  can be easily aligned with the needle holes  311  in the outsole  3  in the following operation step. Since the process of the present invention permits the rear section  12  of the upper  1  to be sewn to the midsole  2  prior to stitching the front section  11  of the upper  1  to the outsole  3 , the process is relatively simple as compared with the prior art. However, while it is preferable to stitch the front section  11  of the upper  1  to the outsole  3  after attachment of the midsole  2  to the upper  1 , the present invention is not limited thereto. The sequence of the steps constituting the method of the present invention may be varied as desired. 
     Despite the simplified processing steps utilized in the method of the present invention, the method still can produce a shoe which has good flexibility at a front part of the shoe and sufficient strength at a rear part of the shoe. 
     The second preferred embodiment of the method according to the present invention is illustrated in FIGS. 6 to  8 . This second embodiment is substantially similar to the first embodiment except that the upper  1 ′ in this embodiment is provided with two separate front stitching margins  113 ′ at left and right sides of the metatarsal region  112  of the upper  1 ′, and that the midsole  2 ′ is formed as a full length midsole which has a heel region  21 ′, a metatarsal region  23 ′, and a toe region  24 ′. The toe section  111  of the upper  1 ′ has a stitching end  115 ′ sewn to a peripheral end of the toe region  24 ′ of the midsole  2 ′. The midsole  2 ′ is indented at left and right sides of the metatarsal region  23 ′ where the front stitching margins  113 ′ are stitched to the outsole  3 ′. Each front stitching margin  113 ′ is stitched to the outsole  3 ′ at one of the left and right sides of the outsole  3 ′. The rear stitching margin  121  of the upper  1 ′ is sewn to the periphery of the midsole  2 ′ along a stitch line (not shown) which extends along full length of the rear stitching margin  121 . This embodiment provides good flexibility at the metatarsal region  112  of the upper  1 ′. 
     Referring to FIGS. 9 and 10, the third preferred embodiment of the method according to the present invention includes utilizing an outsole  3 ″ and a midsole  2 ″. This embodiment is substantially similar to the first embodiment. However, the upper  1 ″ is additionally provided with a frontmost margin  116 ″. Front stitching margins  113 ″ are provided rearwardly of the frontmost margin  116 ″ and at left and right sides of the front section  11  of the upper  1 ″. The outsole  3 ″ includes a front section  31 ″ and a rear section  32 ″ which are formed as separate pieces. The midsole  2 ″ is provided with a rear section  21 ″ and a front section  24 ″ which are also formed as separate pieces. The rear stitching margin  121  of the upper  1 ″ is sewn to the rear section  21 ″ of the midsole  2 ″. The front section  11  of the upper  1 ″ is sewn to the midsole  2 ″ only at the frontmost margin  116 ″. Front stitching margins  113 ″ of the upper  1 ″ are turned outward and are stitched to the left and right sides of the outsole  3 ″ at corresponding positions. The upper  1 ″ is further provided with left and right intermediate stitching margins  131 ,  132  which are turned inward and sewn together. 
     The method of this embodiment provides additional flexing characteristics at the intermediate part of the upper  1 ″ as compared with the first and second embodiments. Of course, an additional support plate maybe provided below or above the intermediate stitching margins  131 ,  132  of the upper  1 ″ in a conventional manner for reinforcing purposes. 
     While the present invention has been described in connection with what is considered the most practical and preferred embodiments, it is understood that this invention is not limited to the disclosed embodiments but is intended to cover various arrangements included within the spirit and scope of the broadest interpretations and equivalent arrangements.

Technology Classification (CPC): 0