JPS595281B2 - Sewn-on barefoot tabi, its manufacturing method and medium-sized tabi used in its manufacture - Google Patents

Description

DETAILED DESCRIPTION OF THE PRESENT EMBODIMENT The present invention relates to an improved sewn-on barefoot pad, a method for manufacturing the same, and a pad for use in the manufacture thereof.

Barefoot tabi that are commonly available can be divided into two types: sewn-on barefoot tabi, which are made by sewing a tread cloth and a rubber or synthetic resin tread sole (hereinafter simply referred to as the tread sole), and attached-on barefoot tabi, which are made by attaching the tread sole to the tread cloth with an adhesive, mainly rubber glue. However, both have advantages and disadvantages and are not satisfactory.

More specifically, sewn-on boot tabi are made by sewing the lining and insole inside out, leaving a fixed seam around the periphery, then turning it inside out to expose the lining and insole, placing the tread sole over the insole, and threading the periphery where the lining and insole are sewn together to sew the tread sole. Since the tread sole is attached by sewing, it is lightweight, and the sole and its surrounding area are flexible, so it fits well to the foot and gives the foot good bounce. However, since the tread sole must be sewn by hand, stitch by stitch, it takes a lot of time and effort to make. Furthermore, a space is required, the seams where the shank and insole are sewn together are all on the inside of the tabi, and a thick piece of fabric reinforcing is sewn to the toe and heel of the shank, with the peripheral seams on the inside of the tabi, so the internal volume of the toe is significantly narrowed and there is a risk of it hitting the toes and damaging them when worn. Furthermore, when forming the toe part, it is necessary to sew together the outer, lining and reinforcing fabric in a layered state while removing the pleats, so there is a high risk of the pleats being unevenly aligned and large wrinkles being formed in some places, which mars the appearance and has the serious drawback that the wrinkles are likely to hit the toes and damage them when worn.

It may also be possible to prevent wrinkles from forming at the tip by distributing the pleats to both side edges, but this would result in the toe being finished in a flattened state, which would also cause a defect that could injure the toes.

Therefore, in conventional sewn-on barefoot tabi, the shoe has been designed to have as much room as possible by making the heel and toe part of the insole wider than the actual width of the toes. However, when this is done, the big toe and toe parts of the finished tabi are significantly wider than the actual shape of the foot, making them flat and ruining the appearance. Furthermore, the wrinkles that sometimes occur when the tabi is sewn on can become larger, making them more likely to damage the toes, and also reducing the fit of the tabi to the toes.

Furthermore, the tread sole is usually sewn starting from the heel, passing through the side edge and finally reaching the toe. In this case, sewing must be done by relying on intuition while creating the appropriate pleats, so it is very difficult to perfectly align the tip of the tread sole with the tip of the cusp, and they are often sewn off to the left or right. This not only ruins the appearance, but also makes the shoe uncomfortable to wear and often leads to many defects such as parts that rub against the foot.

More seriously, with this type of barefoot sandals, in addition to creating a concave groove around the periphery of the sole where the sewing thread is hidden and making an overhanging stitch along these four grooves, it is often necessary to also sew a hexagonal sewing machine along these concave grooves. However, as mentioned above, there is a seam allowance on the inside of the toe, and because both the thumb and the four toes are finished in a flat state, it is not possible to insert the beak-shaped receiver of the hexagonal sewing machine all the way into the toe, so the hexagonal sewing machine stitch on the toe must be done by short-circuiting the base of the fingers in a straight line horizontally, which results in a serious defect in which the joining of the toe is insufficient compared to the other parts.

On the other hand, glued-on barefoot tabi are made by placing a constructed tread on a metal middle mold, hanging and gluing the rim of the tread on the insole placed on the bottom of the middle mold, then gluing the tread on top of that with rubber glue and heating and vulcanizing it. In this case, a middle mold is used, on top of which the tread, insole and tread sole are glued, and the tabi are molded by heating and vulcanizing in that state, so that the internal volume of the tabi is the same volume and shape as the middle mold which matches the shape of the foot, and the tabi obtained is always finished with a constant volume and shape. Furthermore, the tread and tread sole are tightly bonded with rubber glue, preventing water from seeping in from the bonded edges, and the manufacturing process is significantly more efficient than sewing. In particular, rubberized cloth can be placed on the inner surface of the reinforcing cloth of the toe part and vulcanized on the middle mold, so that the big toe and four toe parts are finished in a bulging shape like the toes and can maintain that shape for a long time. Tabi made in this way have many advantages, such as a good appearance, the freedom to insert the fingers, and almost complete avoidance of injury to the fingers.

However, with this type of attached tab, the lining, insole, and tread sole must be firmly joined together with rubber paste, rather than sewn together. Therefore, the insole and tread sole must be surrounded by rubber tape, and a rubber sheet or other core must be placed between the insole and tread sole before rubber paste is applied over the entire surface and vulcanized. As a result, the bottom of the tab is made up of alternating layers of thick cloth and rubber, which are then vulcanized and hardened.
The finished tabi soles are stiff and less comfortable to wear than sewn tabi soles, and the soles also have poor flexibility and do not return to their original position sufficiently.

Furthermore, one of the major drawbacks of the adhesive is that the adhesion between the foot and the adhesive in the crotch area is insufficient, which impairs the stability of the foot.

Therefore, various proposals have been made to improve the fit of the crotch portion by changing the shape of the shank in various ways, but no matter how the shank is cut, the fit of the crotch portion has hardly been improved.

In other words, when the shank is hung onto the insole, first the crotch part of the shank is pulled fully into the crotch part of the medium-sized insole to make it tight, and then the other parts are hung. However, when the toe part is hung, the shank part of the crotch part is pulled strongly towards the toe, so even though the crotch part was initially made to be tightly attached to the medium-sized insole, it ends up being pulled away from the medium-sized crotch part. As a result, when the finished tabi is worn, a gap is formed in the crotch part, causing the crotch part to float, which makes it impossible to avoid a serious defect in which the fit to the foot and the stability of the foot, which are the lifeblood of barefoot tabi, are significantly impaired.

Furthermore, it is difficult to maintain a constant hem width around the entire circumference when attaching the hem, and the hem width of the heel portion, which is hem first, varies, which in turn causes the hem widths of other portions to change.

For example, if the heel is hung too deeply, the lining will lean backwards, and if it is too small, it will lean forwards. Similarly, there will be an unevenness in the width of the hanging on the left and right side edges, which will ruin the appearance and make it difficult to wear.

In addition, with stick-on barefoot tabi, it is often the case that a hexagonal sewing is used at the end to sew the flaps, insole, and tread sole together, and this is considered to be the preferable method. However, if there is an unevenness in the flaps width, there will be areas where the hexagonal sewing thread does not pierce the flaps or insole, resulting in a defect that significantly shortens the lifespan of the tabi.

The first object of the present invention is to provide new sewn barefoot boots which eliminate all the defects of conventional sewn barefoot boots, have a big toe and toe area shaped like a real foot, have a sufficient internal volume for freely inserting toes, yet are wrinkle-free, are extremely comfortable to wear, fit snugly to the foot for safety, and furthermore, have a sole that is fixed to the ground by machine sewing around the entire periphery, allowing for highly efficient production.

Another object of the present invention is to provide a novel method for efficiently producing the above-mentioned excellent sewn footwear, and a further object is to provide a mold for use in the production thereof.

That is, the first invention of the present invention relates to a sewn footwear which uses a shank portion (hereinafter sometimes simply referred to as the shank portion) whose toe portion and side edges have been expanded by the width required for hanging and a midsole (hereinafter sometimes simply referred to as the midsole) whose crotch portion and heel peripheral portion only have been expanded by the width of the seam allowance, and which is joined to form a combined body by sewing the heel portion and crotch portion and by hanging and joining the remaining peripheral portion, and which has a rubber or synthetic resin tread sole placed on top of the combined midsole, and which is joined to the combined body by sewing along the peripheral portion.

The second invention of the present invention relates to a method for manufacturing sewn footwear, which comprises preparing a shank whose toe and side edges have been expanded by the width required for hanging and attaching, and a midsole whose crotch and heel periphery only have been expanded by the width for sewing, joining the shank and midsole by sewing only at two points, the heel and the crotch, inserting a middle mold between the shank and midsole of this partially joined body to combine the joined body and the middle mold, hanging and attaching the toe and side edges of the shank over the periphery of the midsole, superimposing a tread sole made of rubber or synthetic resin on the midsole of the combined shank and midsole thus obtained, and sewing the two together by machine sewing along the entire periphery.

Furthermore, the third invention relates to a mold for manufacturing barefoot boots, which uses a shank with the toe and side edges expanded by the width required for hanging and an insole with only the crotch and heel peripheral edges expanded by the width for sewing, and which is used to join the two by sewing the heel and crotch and the remaining peripheral edges by hanging and is characterized in that it has a shape that matches the shape of the foot, and the lower edge of the crotch and the lower peripheral edge of the heel are cut out so as to accommodate the seam allowance where the shank and insole are sewn together.

According to the present invention, even though the boots are sewn barefoot, the toe part between the hindfoot and the insole does not need to be pleated while sewing, so there is no need to use a special sewing machine for pleating and sewing. Also, because pleating is not performed, there is no risk of large wrinkles in the toe part, even though the toe part has the same dimensions and shape as the toe of the foot. Also, because there is no seam inside the toe part, the toe part has a sufficient internal volume so that the toes can be inserted freely, without the risk of damaging the toes when worn. Moreover, the crotch part fits closely to the foot and does not float up, ensuring stability of the foot when worn, and many other effects can be achieved.

Furthermore, because the toe portion of the barefoot tabi of the present invention has a sufficient internal volume, the tread sole can be secured by six-sided machine sewing around the entire circumference, including the periphery of the toe portion, which was not possible with conventional sewn barefoot tabi. This significantly improves the production efficiency of tabi, and because there is no variation in the hem width, there is the great advantage that strong six-sided machine sewing can be achieved that reliably pierces the tread or insole around the entire circumference.

The above-mentioned advantages can only be obtained by carrying out the method of the present invention, which involves first joining the shank and insole by sewing only the crotch and heel portions together, then inserting a midsole that matches the shape of the foot into this combined body to reliably fit the crotch and heel portions to their respective parts of the midsole, and then hanging and attaching the toe portion and side edge portions of the shank onto the midsole, and then placing the ground sole on the midsole of the combined shank and insole thus assembled, and sewing the periphery with a sewing machine.

That is, according to the method of the present invention, the shank and insole are joined by sewing only the crotch and heel parts, and then the middle part is inserted and assembled. Therefore, the seam allowance of the crotch part and the seam allowance of the heel part join with the periphery of the crotch and heel parts of the bottom of the middle part, and the combined body of the shank and insole is tightly attached to the surface of the middle part. Therefore, even if the toe part is fully folded in, the crotch part will not float up, and both the left and right side edges are attached with a specified hanging width.

In order to ensure these effects, it is necessary to use a lining with the toe and side edges expanded by the width required for hanging and pasting, and an insole with only the crotch and heel edges expanded by the width of the seam.

Alternatively, the side edges and the periphery of the toe part are further extended by, for example, 3 to 6 mm from the corresponding part of the bottom surface of the medium-sized mold used for hanging and pasting.
It is preferable to use an expanded insole and bond it in the manner described above.

As described above, according to the method of the present invention, when the middle mold is inserted into the combined body of the shank and insole and assembled, the seam allowances of the crotch and heel portions are exposed to and engage with the crotch and heel portions of the bottom of the middle mold, thus ensuring close contact between the two. Therefore, it is advisable to use a middle mold in which the lower edges of the crotch and heel portions are cut out so that the seam allowances of the sewn parts can be accommodated.

However, since the lever die is used only for attaching the toe part and side edge as described above, this die must be capable of being inserted and assembled into the combined body of the cusp part and the insole before hanging, and must have a size and shape such that it can be easily removed after the hanging is attached.

The inventors have discovered that when the brims and insoles are joined by sewing only the crotch and heel parts, the same shape as the mold used for conventional full-edge hanging attachment can be used to fully achieve the purpose, and there is no need to use any special stretchable mold, and therefore sewn-together barefoot tabi can be produced with significantly high work efficiency.

This medium may be made of metal or wood.

The sewn-together body of the shank and midsole and the ground sole can be performed according to the conventional sewing method for barefoot tabi. However, the internal volume of the toe part of the shank and midsole combined body made by the method of the present invention is wide and thick enough to freely accommodate the beak-shaped receiving piece of the hexagonal sewing machine, so that the two can be joined by sewing the hexagonal sewing machine along the concave groove of the ground sole. Moreover, in this case, the midsole and the shank overlap at a certain angle all around, so that the three parts of the shank, midsole, and ground sole can be sewn together.
The patient is securely stitched up.

The peripheral edge of the tread sole sewn in this manner can be oversewn to the lower edge of the flaps to make the connection of the tread sole stronger.

The ground sole is the same as the one proposed by the inventor in 1970.
As described in Publication No. 0-31145, a thin heel reinforcement piece that is integral with the sole body is provided on the periphery of the heel part of the ground-contacting sole, and many pairs of long radial ridges are formed on the underside of the periphery, and a needle is inserted between the ridges to sew the gold edge of the reinforcement piece to the heel part of the shank. Alternatively, as proposed elsewhere, many pairs of ridges can be provided on the outer periphery of the ground-contacting sole, and a needle can be inserted between the ridges to sew the periphery of the ground-contacting sole to the shank. In this case, the periphery other than the heel can be made into an inclined surface so that the surface in contact with the insole is larger than the tread surface, and pairs of projections can be provided on the inclined surface, and the projections can be inserted between the ridges to sew the metal edge of the reinforcement piece to the heel part of the shank.

Furthermore, it goes without saying that the present invention can be effectively applied not only to flat ground soles, but also to soles in which the arch portion is curved upward from the tread surface to the back surface to provide a good fit with the foot.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to the drawings, showing an embodiment of the present invention. However, it will be understood that the scope of the present invention is not limited thereto.

In the present invention, the insole 2 is connected to the toe crotch 3 and heel 4.
Since only the toe portion 5 and the side edge 6 are sewn together by a sewing machine and the toe portion 5 and the side edge 6 are joined by hanging and pasting, the toe portion 5 and the side edge 6 of the visor portion 1 are expanded by the width W required for hanging as shown in FIG.

Of course, the lining 1 is made up of two pieces of cloth, one on top and one on the bottom, and since it is common to layer reinforcing cloth 7 at the toe and heel areas, in some cases the toe area of the peripheral surface 1 may be made of normal size, and only the peripheral edge of the reinforcing cloth 7 overlying it may be expanded by width W.

On the other hand, the insole 2 is made to be of normal size from the toe portion to the side edge as shown in FIG. 2, and the toe crotch portion 3' and heel portion 4' are enlarged by the seam allowance W.

However, depending on the circumstances, the toe portion and side periphery of the insole may be enlarged to be somewhat larger than the base of the medium size.

In this way, the toe portion and side edges of the periphery of the finished buckle will be raised.

Thus, in the usual way, the outer and inner peripheral edges of the big toe and four toe sides are sewn together along the peripheral edges, reinforcing fabric is sewn in the required areas, and this is then turned inside out and layered on the insole. The heel portion 4 of the peripheral edge 1 and the heel portion 4' of the insole 2 are sewn together with a sewing machine, and further the toe crotch portion 3 of the peripheral edge and the toe crotch portion 3' of the insole are sewn together with a sewing machine, while the toe portion 5°, 5' and the side edges 6, 6' are left unstitched.

Next, the item sewn with the sewing machine is turned inside out and the peripheral surface 1
The insole 2 is turned outward, as shown in FIG.
A metal or wooden mid-form 8 made to fit the shape of the foot is inserted into the combination of the peripheral surface 1 and the mid-sole 2, and the toe crotch portion where the peripheral surface and the mid-sole are sewn together is positioned at the toe crotch portion of the mid-form, and the heel portion where the sewn together of the bulging mid-sole is positioned at the heel portion of the mid-form, thus aligning the upper leg edge seam of the peripheral surface 1 with the upper leg edge 9 of the mid-form, and fitting the mid-sole 2 to the bottom surface of the mid-form.

Next, the side edge 6 of the peripheral surface 1 is hung over the peripheral edge of the midsole on the bottom surface of the intermediate mold, and the hung parts are bonded together with a suitable adhesive. Finally, the toe portion 5 of the peripheral surface is hung over and bonded to the toe portion 5' of the midsole.

The adhesive used can be a rubber-based glue used to attach the treads of footwear, but since this adhesion only requires that the peripheral surface and the insole be joined in the correct position until the overlock stitching or hexagonal sewing is completed, any suitable glue suitable for this purpose can be used.

Thus, the bottom surface of the combined body in which the peripheral surface and the insole are combined is a fourth
The result is the state shown in the figure.

That is, according to the present invention, the peripheral surface 1 and the insole 2 are joined by hanging and pasting from the toe portion to the side edge C, and the toe crotch portion γ and the heel portion γ are sewn together by machine sewing, so that there is no seam inside the toe portion and the internal volume is formed large enough to accommodate the toes.

As shown in FIG. 5, the intermediate mold used for hanging and attaching the toe and side edges has advantageously a notch or chamfer 10 formed in the crotch area and the lower peripheral edge of the heel area so that the seam allowance can be accommodated therein.

When the periphery and the insole are joined at their entire periphery as shown in FIG. 4, the inner form is removed, the tread sole is placed over the insole, and the periphery is oversewn to the periphery and the insole to form the sewn footwear of the present invention.

FIG. 6 shows a grounding sole 11 having a groove 12 around its periphery for accommodating sewing thread, a heel reinforcing piece 13 at its heel, and a pair of ridges 14 around the periphery of this reinforcing piece and around the periphery of the grounding sole other than the heel, with a needle passing between the pair of ridges to perform overlocking. However, the present invention can of course use any other type of grounding sole, for example one in which the arch portion is curved upward in an arc.

Generally, sewn-on barefoot boots are undesirable because the peripheral surface of the toe becomes flattened when not in use.
The present invention solves this problem by the simple means of changing the shape of the midsole.

FIG. 7 is a plan view of an example of an insole used for this purpose, in which the crotch portion 3' and heel portion 4' are both made wider by the seam allowance W (shown by dotted lines), and the other portions are made wider by an amount V (shown by wavy lines) than the width of the insole of the midsole shown by dotted lines, and when the midsole is combined and the toe portion and side edges are hung, this wider portion vbs is folded into the side of the midsole, and the peripheral surface is hung and attached on top of it.

Therefore, when the ground sole is placed on top of this insole and sewn together with a hexagonal sewing and an overcasting of the periphery, the insole is placed in an elevated state on the inside of the side edge of the tab, and therefore the periphery on the outside of it appears bulged. Also, because the periphery of the insole is in this elevated state, the side edge of the tab is reinforced, and furthermore, the needle of the hexagonal sewing and the overcasting will necessarily pierce both the periphery and the insole, so the periphery of the tab is reinforced to that extent and damage to this part is completely prevented.

FIG. 8 shows a side view of the sewn-on undergarments according to the present invention thus constructed.

Furthermore, 15 is a heel reinforcement fabric.

As is clear from the above explanation, according to the present invention, the bulging surface and the insole are first sewn together by machine only at the heel and crotch areas, then this is combined with the inner mold, the toe area and side edges are attached to form the tanning area, and the tread sole is attached by sewing its periphery. Therefore, the bulging surface and the insole are joined in a regular relationship without any irregularities, and there is no seam on the inside of the toe area.
Since the medium-sized tabs have a sufficient internal volume equivalent to that of the corresponding portion of the medium-sized tabs, excellent barefoot tabs completely eliminate defects in the toe area due to the seam allowances and wrinkles of conventional sewn-on barefoot tabs, and can be produced extremely efficiently using a normal, extremely simple medium-sized tab and without the need for heat vulcanization, thus providing ideal barefoot tabs that completely eliminate the disadvantages of sewn-on and stick-on barefoot tabs and incorporate only their advantages.

Furthermore, as already explained, another embodiment of the present invention has the advantage that the flattening of the toe portion, which is considered to be a serious defect of conventional sewn-on footwear, is avoided and an excellent sewn-on footwear that always remains in a bulged state is provided.

[Brief description of the drawings]

Fig. 1 is a plan view of the bulging surface used in the present invention, Fig. 2 is a plan view of the midsole, Fig. 3 is a cross-sectional view showing the bulging surface and the midsole sewn only at the crotch and heel parts when assembled into a medium-sized shoe, Fig. 4 is a plan view of the midsole surface when the midsole is joined to the bulging surface at its entire periphery, Fig. 5A is a bottom view of a preferred medium-sized shoe used in the method of the present invention, Fig. 5B is a side view of the crotch and heel parts when they are chamfered, Fig. 5C is a side view of the same parts when notches are provided, Fig. 6 is a bottom view of a preferred example of a ground sole used in the present invention, Fig. 7 is a plan view of the midsole used in one embodiment of the present invention, and Fig. 8 is a partial side view of a sewn-on shoe tab made by the method of one embodiment of the present invention. In the figures, 1 is the bulging surface, 2 is the midsole, 3 is the crotch part, 4 is the heel part,
5 is the toe portion, 6 is the side edge, 7 is the reinforcing cloth, and 8 is the medium size.

Claims (1)

[Claims] 1. Sewn barefoot boots using a boot cloth whose toe and side edges are expanded by the width required for hanging and an insole whose toe crotch and heel periphery only are expanded by the width of the seam, the two being joined together to form a combined body by sewing the heel and toe crotch and the remaining periphery by hanging and a ground sole made of rubber or synthetic resin is placed on the combined insole, and the combined body and the ground sole are joined by sewing along the periphery. 2. Sewn barefoot boots as claimed in claim 1, using a midsole whose toe crotch and heel periphery are expanded by the width of the seam and whose side and toe periphery are expanded more than that of the insole. 3. Sewn barefoot boots as claimed in claim 1, using a ground sole with a concave groove on the periphery, and joined to the combined body by sewing with a sewing machine and overcasting at required locations. 4. A method for manufacturing sewn-in barefoot tabi, characterized in that a lining with a toe section and side edges expanded by the width required for hanging and an insole with only the toe crotch and heel periphery expanded by the width for sewing is prepared, the lining and insole are joined by sewing only at two points, the heel section and the toe crotch section, a middle mold is inserted between the lining and insole of this partially joined body to combine the joined body and the middle mold, the toe section and side edges of the lining are hung and attached over the periphery of the insole, a rubber or synthetic resin ground sole is superimposed on the midsole of the combined lining and insole thus obtained, and the two are joined by sewing machine along the entire periphery. 5. A method for manufacturing sewn-in barefoot tabi, characterized in that the lining and insole are superimposed inside out to form the toe crotch and heel sections and joined, the middle mold is inserted into the middle mold to perform hanging and attaching of the toe section and side edges. 6. A mold for manufacturing sewn footwear, which uses a lining whose toe and side edges are expanded by the width required for hanging and an insole whose crotch and heel periphery only are expanded by the width for sewing, and which is used to join the two together by sewing the heel and crotch and by hanging and attaching the remaining periphery, characterized in that it has a shape that matches the shape of the foot and the lower edge of the crotch and the lower peripheral edge of the heel are cut out so as to accommodate the seam allowance where the lining and insole are sewn together.