Method and apparatus for manufacturing shoes using lasts

Abstract: The present invention discloses a shoe making mechanism and a manufacturing method of a shoe, in which a work for fastening an inner sole to a wooden last can be done easily and speedily. In the manufacturing method of the shoe, metal plates (23,24) having a magnetic absorption property are sticked to an inner sole (21) to form a magnetic absorption portion. On the other hand, magnets (33,34) are buried at positions corresponding to the metal plates (23,24) in a bottom portion of a wooden last (31). The metal plates (23,24) are attached to the magnets (33,34) buried in the wooden last (31) so that the inner sole (21) is fastened to the wooden last (31). After the inner sole (21) is fastened to the wooden last (31), the wooden last (31) is covered with an upper, and the upper and the inner sole are joined by stitches.

Description: FIELD OF THE INVENTION The present invention relates to a method and mechanism for manufacturing shoes using a shoemaker's last. More particularly, the present invention relates to the foregoing method and mechanism for manufacturing a shoe wherein an inner sole of the shoe is fastened to the last in a detachable manner so as to make a so-called stitching process easy. BACKGROUND OF THE INVENTION Conventional methods for manufacturing a shoe will be described briefly with reference to Fig. 1. First, in the step (a) a shoe upper 11 is formed by stitching genuine leathers or synthetic leathers or the like. In the step (b) an inner sole 13 is attached to a wooden mold 12 by means of nailing and starching and the like. Subsequently, in the step (c), the wooden mold is covered with the stitched shoe upper 11, and a lower fringe portion of the shoe upper 11 is stitched to a peripheral portion of the inner sole 13. As a result of such work, the lower fringe portion of the shoe upper 11 is bent along the surface of the wooden mold 12. Further, the bent portion 1 la of the shoe upper 11 is roughened so as to be adhered securely to a bottom sole in a subsequent step described below. In the subsequent steps, different processes are carried out in a VP manufacturing method and a CP manufacturing method. As an example of the subsequent processes, the CP manufacturing method will be described hereinafter. In the step (d) insert members such as a cushioning member 14 for protecting the arch of the foot and a member 15 for bending the front portion of the inner sole 13 are mounted on the inner sole 13. Further, in the step (e) a shoe bottom 16 formed of rubber and leather and the like is manufactured. In addition, in the step (f) the shoe bottom 16 is adhered to the bent portion of the shoe upper 11 and the inner sole 13 by means of a pressure-applying machine. In general, an insert is placed in the interior space of the shoe formed by the inner sole 13 and the shoe upper 11 and the insert (not shown) is adhered to the upper surface of the inner sole 13. Thus, the manufacturing process of the shoe is finished. However, in the conventional manufacturing processes of the shoe, in the step (b) the work to fasten the inner sole 13 to the wooden mold 12 was carried out by nailing or adhering or the like. When the inner sole 13 is fastened to the wooden mold 12 by nailing, a nail is usually driven into two portions in a toe section and two portions in a heel section of the inner sole 13, respectively; as a result, four portions of the inner sole 13 are required to be fastened by nailing. After the fastening of the inner sole 13 to the shoe upper 11 has been completed, the four nails driven into the wooden mold 12 must be pulled out; thus, eight steps of pulling out the nails per pair of shoes are required. In addition, when the inner sole is fastened to the wooden mold in a position on the wooden mold which deviates from the normal position, the nails driven into the wooden mold through the inner sole are required to be pulled out and the work for fastening the inner sole to the wooden mold is required to be carried out again after pulling out all nails. Further, there might be caused an accidental injury due to the failure to pull out the nails. Also in the adhesion of the inner sole 13 to the wooden mold 12, in the same manner as nailing, the inner sole 13 is required to be adhered to the wooden mold 12 at four portions in the inner sole 13, namely, at the two portions in the toe section and the two portions in the heel section. After the inner sole 13 is secured to the shoe upper 11, the inner sole 13 is required to be stripped off from the bottom portion of the wooden mold 12, so that eight steps are required. In addition, shoemakers need an adhering machine of high price that would cost, for example, ten million Yen each. SUMMARY OF THE INVENTION A primary object of the present invention is to solve the problems encountered during the step of mounting the inner sole 13 on the last 12 in the conventional manufacturing methods. To accomplish this object, the inventor of the present invention has made extensive tests, and has found that an unique last and an unique inner sole may solve the problems. The last and the inner sole of the present invention may provide an unique attaching and detaching means for attaching the inner sole to the last easily and for detaching the inner sole from the last easily. DE-B-1198244 discloses the magnetic mounting of inner soles on shoe lasts using magnets embedded in the sole-defining portion of the last and a strip of magnets which is placed over an inner sole in contact with that sole-defining surface of the last. The inner sole can later be removed from the last after removal of the magnet-containing strip to break the magnetic circuit. A pressure sensitive strip with ferromagnetic material on it may be mounted on the last or on the inside or outside of the inner sole. A first aspect of the present invention provides a shoemaking method as defined by claim 1. A second aspect of the invention provides the method of claim 3. A third aspect of the present invention relates to an inner sole for a shoemaking method, as defined by claim 4. A fourth aspect of the present invention provides a shoemaker's last in accordance with claim 5. In the present invention, the inner sole of the shoe is fastened to the bottom portion of the last freely detachably by means which allow a misarrangement of the inner sole on the last to be adjusted easily when the inner sole is fastened in a position which deviates from the normal position that the inner sole is to be fastened. Further, there is no fear that products with flaws and stains are manufactured. Since nails are not used when the inner sole is fastened to the last, there is no danger of workers being injured due to the failure of pulling out the nails. In the present invention, a machine for starching and the like is not necessary, so the cost of equipment is reduced. Further, the steps of, e.g., nailing, pulling out of the nails, starching, and ripping off can be omitted, in comparison with the nailing and the starching methods of the prior art. In the shoemaking work the inner sole is fastened to the last, the last is covered with the shoe upper, and the inner sole is joined with the shoe upper by stitches. Since a strong force to stretch the inner sole in one direction is not required, power for fastening the inner sole to the last can be produced by means of magnetic absorption (i.e., the ability to be attracted by a magnet). In addition, as metal with a magnetic attraction property is used as detachable means, the inner sole can be fastened easily to the last. And, when the inner sole is equipped with magnets serving as detaching means, increased blood circulation due to the magnetic force is expected. According to the present invention, since the inner sole is fastened to the bottom portion of the last magnetically detachably, the inner sole can be fastened to the last easily and speedily, and many of the prior art manufacturing steps can be largely omitted. BRIEF DESCRIPTION OF THE DRAWINGS For a more complete understanding of the present invention and the advantages thereof, reference is now made to the following description taken in conjunction with the accompanying drawings, in which: Fig. 1 contains perspective views showing briefly a conventional manufacturing process of a shoe; Fig. 2 contains perspective views showing a last and an inner sole of the present invention; and Fig. 3 contains perspective views showing a manufacturing method of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Fig. 2 shows a last with a shoe inner sole of an embodiment according to the present invention. A shoe inner sole 21 of the present invention is formed of a flexible sheet in the shape of a foot as viewed from above. Synthetic resin sheet containing metal powder and materials which are attracted by a magnetic force and the like may be used to mount the inner sole magnetically on the last 31. Vinyl can be used for the flexible sheet 22. In addition, sheet 22 of the inner sole 21 may be formed of a material exhibiting a magnetic attraction force prepared by adding metal powders having a magnetic attraction property into synthetic resin, so that the whole sheet 22 serves as a magnetic absorption section. On the other hand, a body 32 of a last 31 is formed of a synthetic resin and wood that fit desired sizes and styles of shoes. Note that the term "last" is not limited to a last made of wood, but it denotes a shoemaker's last or mold for manufacturing shoes. In one embodiment of the present invention, the body 32 of the last 31 has two magnets 33 and 34 buried in its bottom portion 32b. Further, an iron plate 32b is adhered to the bottom portion 32 so as to cover it entirely. The magnets 33 and 34 are preferably disposed at the toe portion and the heel portion of the shoe. The number and the positions of the metal plates and the magnets of the last 31 may be varied suitably according to the objectives. The whole body 32 of the last 31 may be formed of a material exhibiting magnetic force in itself, so that the whole body 32 exhibits magnetic force. This can be accomplished, for example, by preparing synthetic resin containing metal powders having a magnetic attraction property for the body 32. In the manufacturing method of the present invention as shown in Fig. 3, the inner sole 21 is fastened to the bottom portion 32a of the last 31, utilising the magnetic attraction force between the last and the inner sole magnets 23 and 24. The last 31 is then covered with the shoe upper 11, and the lower fringe portion 1 la of the shoe upper 11 is joined to the outer peripheral portion of the inner sole 21 by stitches. When the lower fringe portion 11a of the shoe upper 11 is being joined to the outer peripheral portion of the inner sole 21 by stitches, since the inner sole 21 may be merely fastened to the last 31 and localised force is not applied to the inner sole 21, the inner sole 21 can be fastened satisfactorily to the last 31 by a fastening force utilising magnetic force. Thus, the inner sole 21 is fastened to the last 31 utilising magnetic attraction force, so that an attaching operation of the inner sole 21 to the last 31 and a detaching operation of the inner sole 21 therefrom can be carried out easily and speedily. Additionally, a positioning error of the inner sole 21 to the last 31 can be easily adjusted. When the magnets are attached to the inner sole, it can be expected that circulation of the blood of users of the shoes equipped with the above inner sole and the like will be promoted by the magnetic force. Although the preferred embodiment of the invention has been described in detail, it should be understood that various changes, substitutions and alterations can be made therein without departing from the scope of the invention as defined by the appended claims.

Claims: A shoe manufacturing method comprising the steps of: taking a last (31), and preparing an inner sole (21) comprising first means which can cooperate with second means in the last to attach the inner sole magnetically to the last; attaching said inner sole (21) magnetically in a freely detachable manner to a last (31); covering the last (31) with a shoe upper (11); and joining the inner sole (21) to the upper (11) by stitching; characterized in that said first means is material from which the inner sole is made and it is a synthetic resin material containing metal powder with a magnetic attraction property. A method according to claim 1, wherein the inner sole is made of a sheet consisting of said synthetic resin material containing metal powder with a magnetic attraction property. A shoe manufacturing method comprising the steps of: taking a last (31) and preparing an inner sole (2) which has first fastening means to cooperate with second means in the last to attach the inner sole magnetically to the last; attaching said inner sole (21) magnetically in a freely detachable manner to a last (31); covering the last (31) with a shoe upper (11); and joining the inner sole (21) to the upper (11) by stitching; characterised in that said second means of the last is the material of which the last is made and is a synthetic resin material containing metal powder with a magnetic attraction property. An inner sole of a shoe made of a sheet (22) of a synthetic resin containing metal powder with a magnetic attraction property; whereby in combination with magnetic attaching means (33, 34, 32) formed in a shoemaker's last (31), said inner sole can be attached magnetically to said last in a freely detachable manner. A shoemaker's last which is: a body (32) of a material with a magnetic attraction property, whereby it is possible to attach an inner sole (21) to said last (31) magnetically in a freely detachable manner, characterized in that the material with a magnetic property is a synthetic resin material containing metal powder with a magnetic property.

Inventors: FURUHASHI MASANOBU, FURUHASHI, MASANOBU
Applicants: FURUHASHI MASANOBU, FURUHASHI, MASANOBU
Application year: 1995
Main classification: A43D3
IPC codes: A43D3, A43B13