JPS6214281B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing shoes in which a sole consisting of a heel wedge or midsole and an outsole is injection molded by laminating and combining sole materials of different types or colors.

BACKGROUND OF THE INVENTION Methods for manufacturing shoes with multi-layer soles are well known. That is, a shoe last with a shoe cover attached and a split side mold are assembled, and only the single sole mold with a sole design engraved thereon is sequentially lowered to form a predetermined cavity, and each This is a method of sequentially injecting the required bottom material into the cavity and integrally molding a plurality of layers of the bottom into the cover. In this way, the same bottom mold is used to form a predetermined cavity, and the cavity is formed by simply lowering the bottom mold in sequence, so it is inevitable as shown in Fig. 1 or 2. First, the first cavity is formed by directly covering the upper surface of the cavity, and the midsole sole material, which is lightweight and has excellent cushioning properties, is injected into this cavity and directly molded integrally with the jacket.

Next, in FIG. 1, the outer sole is injection molded to fill the inner ground contact surface, and in FIG. 2, it is simply laminated in layers over the entire ground contact side of the midsole. Therefore, in FIG. 1, the shoe molded by the above method has the outer periphery of the sole covered with the same material as the midsole, so the midsole is made of one color when viewed from the lateral direction, and it can be seen as a multi-layer sole. In addition, the toe and heel areas, which need to be reinforced the most, are made of sole materials that have excellent cushioning properties required for midsoles, but are inferior in anti-slip and abrasion resistance. As a result, it was unable to function as a toe reinforcing piece or an outer sole. Similarly, in Fig. 2, since the midsole and the outer sole are simply laminated in layers, the toe part and toe reinforcing piece, etc., are made of an outer sole material with excellent slip resistance and abrasion resistance. However, there was a drawback that it could not be integrally molded and reinforced at the same time as the outer sole.

Therefore, as shown in FIG. 3, a method for manufacturing shoes having a multi-layered sole consisting of a heel wedge 12 or a midsole and an outer sole having a toe reinforcing piece, etc. is disclosed in Japanese Patent Application Laid-open No. 145601/1983. ing. That is, a shoe last that has a partition that protrudes to partition the bottom surface of the last in the horizontal direction and has a shoe cover attached thereto, and a shoe last that is fitted with a shoe cover at a position that matches the longitudinal direction of the partition on the upper edge of the inner periphery of the side mold. A side mold and a sole mold having protruding protrusions are combined to form a cavity divided into two by the partition of the shoe last, the upper surface of the sole mold and the protrusions of the side mold, and one of them is The first bottom material is injection molded into the cavity, and then the bottom mold is lowered to form a second bottom material into the cavity.
A method of manufacturing shoes having a desired laminated sole by injection molding the sole material of the present invention. However, in this method, the last and side last remain fixed together until the injection molding of the sole is completed, so the last and side last remain fixed together until the injection molding of the sole is completed. The protrusions protruding from the side molds are held in a press-engaged state at a corresponding portion such as the lower circumferential tape or edge of the cover. Therefore, the engagement part between the partition and the protrusion is not filled with sole material, so a cutout is created in a part of the lower circumferential tape or burr of the shoe that has been injection molded, and this cutout is extremely Since it was a thin layer, it was not possible to satisfy both the appearance and the strength.

The present invention is an improvement on the above-mentioned method, in which a shoe last with a shoe cover attached and a side last are assembled and fixed, and a sole mold having a pair of protrusions is incorporated therein, so that only this same sole mold can be raised or With the structure described in the claims, which can be lowered to form a predetermined bottom cavity, the third
As shown in the figure, it has a multi-layered sole made of an elastic material such as rubber or synthetic resin, or a foam thereof, and the toe part is partially a single-layered sole with only the outer sole, and the heel wedge or midsole and outer sole. This invention has invented a method for manufacturing an integrally molded shoe that can prevent a decrease in strength at the boundary between the two and the outer layer, and can clearly distinguish the layers in appearance.

Embodiments of the present invention will be described below with reference to the drawings.
As shown in FIGS. 4 to 6, the mold used in the present invention is composed of a shoe last 1, a side mold 6, and a sole mold 4.

A shoelace 2 sewn by the California method is attached to the shoe last 1.

The side mold 6 is divided so that it can be opened and closed in the lateral direction, and has a lateral protrusion on its inner upper periphery to form an edge surface by coming into contact with the lower peripheral side of the last 1 on which the shoe cover 2 is attached. 14 are provided protrudingly, forming a wall surface having a square cross section. By assembling this side mold 6 with the shoe last 1, a cavity is formed between the inner surface of the side mold 6 and the lower circumferential side of the shoe cover 2.

The top surface of the bottom mold 4 is engraved with designs that do not run directly in the vertical direction, such as wavy or linear protruding shapes that extend in the horizontal direction, no designs, pear-shaped designs, bamboo-like designs that extend in the vertical direction, and designs that have many obstacles. It's good to be there. A pair of upward protrusions 5 are provided on the inner and outer edges of the upper surface of the bottom surface 4 at predetermined positions from the stepping part to the heel part, the inner surface of which has a shape that follows the outer surface of the shank 2 at that location. This protrusion 5 is formed so that its upper surface and outer surface coincide with the inner surface of the side mold 6.
The sole mold 4 can be slid up and down along the inner wall surface of the side mold 6 while the shoe last 1 and the side mold 6 remain assembled. The lower surface of the shoe last 1 is configured to be close to the upper surface of the sole mold 4 at a zone connecting the pair of projections 5. A seam part 3 is formed on the inner sole of the california style shoe cover 2, and this part becomes thicker, which prevents the lower surface of the shoe last 1 and the upper surface of the sole mold 4 from coming close to each other. Therefore, it is preferable to provide at least a recess into which the seam 3 can fit into the lower surface of the last 1 adjacent to the upper surface of the sole mold 4, and to embed the seam 3 in this recess. An elastic body such as urethane rubber is fitted into this recess so as to approximately follow the bottom surface of the last 1.

A pair of protrusions 5 are protruded from the top surface of the bottom mold 4, but it is also possible to protrude a plurality of pairs of protrusions or to protrude more protrusions from the outer edge than from the inner edge. be.

When the side mold 6 is clamped from left and right to the shoe last 1 with the shoe cover 2 attached, the protrusion 14 of the side die 6 presses against the lower circumferential surface of the shoe cover 2, and the inner surface of the side die 6 and the lower circumference of the shoe cover 2 are pressed together. A cavity is formed between it and the side surface. Next, when the sole mold 4 is raised and the upper surface of the sole mold 4 approaches the lower surface of the shoe last 1,
A pair of protrusions 5 protruding from the upper surface of the bottom mold 4 simultaneously block the cavity formed by the inner surface of the side mold 6 and the lower circumferential surface of the sleeve 2, so that the toe side and the heel side A cavity is formed which is divided into two parts. The cavity corresponding to the heel wedge 12 or midsole on the heel side is defined as a first bottom cavity 7. On the toe side is a cavity 9 corresponding to the toe portion 8. A heel wedge or midsole sole material made of an elastic material such as rubber or synthetic resin is injected into the first sole cavity 7 to form a first molded shoe that is integrally molded with the heel 2. This is the first step. Here, a through hole opening into the first bottom cavity 7 is bored in a portion corresponding to the tip 13 of the heel wedge 12 of the side mold 6, and a contact point of a micro switch is fitted into this through hole. If the switch is configured to work in conjunction with the bottom material injection machine, the bottom material will be injected into the first bottom cavity 7, the filling pressure will press the contact point of the micro switch, and this signal will be transmitted to the injection machine. The injection is stopped and each heel wedge 12
It is possible to more reliably specify the injection amount of bottom material appropriate for the purpose of the invention, and to eliminate loss of bottom material.

The protrusion 5 protruding from the upper surface of the bottom mold 4 is formed to reliably block the cavity formed between the lower circumferential side surface of the sleeve 2 and the inner surface of the side mold 6. On the other hand, it is better that the upper surface of the sole mold 4 and the lower surface of the shoe last 1 are in close contact with each other, but it is not necessary that they are in close contact with each other, and it is sufficient that they are close to each other.

The reason for this is that the gap between the lower surface of the last 1 and the upper surface of the sole 4 is extremely thin compared to the thickness of the cavity in the first sole cavity 7. The first sole material injected into the cavity 7 first fills the cavity, which is thick and difficult to cool and easily flows, and then gradually passes through the thin gap between the bottom surface of the shoe last 1 and the top surface of the sole mold 4. This is because the injection of the bottom material may be set in advance to stop at this timing. Furthermore, in order to make this timing more reliable, the presence or absence of filling of the first bottom material injected into the first bottom cavity 7 is detected by a micro switch fitted into the through hole of the side mold 6. By transmitting this to the injection machine and stopping the injection of the sole material, it is possible to prevent the sole material from leaking out from the gap between the lower surface of the shoe last 1 and the upper surface of the sole mold 4. Next, only the sole mold 4 is lowered, and its upper surface is fixed to the contact surface position of the outer sole 10, and the first molded shoe, the upper surface of the sole mold 10, and the split side mold 6 are assembled.
A new second bottom cavity 11 for the outer sole 10 is formed which communicates with the cavity 9 corresponding to the toe part 8 constituted by the inner surface, and this second bottom cavity 11 is filled with rubber or Injecting a sole material of a different type or color from the heel wedge sole material made of an elastic material such as synthetic resin,
The outer sole 10 is integrally molded onto the first molded shoe. This is the second step. After the first and second steps described above, the sole mold 4 and the split side mold 6 are unassembled and removed from the shoe last 1 to form the desired laminated sole with one layer on the toe side and two layers on the heel side. get shoes

Here, the bottom material for the midsole etc. is injected into the first bottom hollow part 7 corresponding to the heel wedge etc., and the bottom material for the outer sole is injected into the hollow part 9 corresponding to the toe part 8 which has already been formed separately. It is also possible to obtain a shoe having a laminated sole integral with the outer sole 10 to be molded next by injecting a sole material for the toe section 8 made of an elastic material such as rubber or synthetic resin of a different color and/or different quality.

In this way, the present invention provides a sole mold in which a shoe last 1 equipped with a shoe cover and a side mold are assembled, and a pair of protrusions 5 are provided protruding from the inner and outer edges of the upper surface of the sole mold. 4
With the same simple operation as in the conventional method of simply raising the protrusion 5, the above protrusion 5 reliably blocks the cavity corresponding to the edge etc., and the upper surface of the bottom surface 4 is brought close to the lower surface of the shoe last 1. For example, it is possible to form a sealed first bottom cavity 7 corresponding to the heel wedge 12, and by simply injecting the first sole material into this first bottom cavity 7, in particular the contour of the tip 13 can be formed. A desired first molded shoe can be formed in which a heel wedge 12 with a clear heel wedge 12 is integrally molded.Next, by simply lowering and fixing only the sole mold 4 until its upper surface comes to the contact surface of the outer sole 10, the toe A second bottom cavity 11 for the new outer sole 10 communicating with the side cavity 9 can be formed, and this second bottom cavity 11 is made of a material different from the first sole material and/or a different color. By simply injecting the second sole material, it is possible to obtain a shoe having a multilayer sole integrally molded with an outer sole 10 that clearly distinguishes the boundary with the heel wedge 12 and allows for different color schemes. By leaving one or more pairs of marks of the protrusions 5 of the sole mold 4 on the lower side edge of the outsole 10 when stepped on, it is possible to provide an accented appearance and reduce bending resistance to improve the wearer's foot shape. It can reduce fatigue.

Since the toe part 8, heel part, etc. can be integrally molded and reinforced with an outer sole material that has excellent heat resistance, abrasion resistance, impact resistance, etc., damage to the sole is almost eliminated. Due to its improved functionality, the wearer can wear it with confidence even during strenuous exercise. In addition, the manufacturing process is simple and easy without any difference from the conventional work process, and it is possible to improve productivity and simplify the work. To provide a shoe with a clear and elegant multi-layer sole, which can form a smooth and uniform surface, eliminates the conventional drawbacks such as leaving contact marks on this part and becoming thin, impairing strength and appearance. It is possible.

As described above, the present invention enables a predetermined bottom cavity to be formed by a simple operation of assembling a sole mold with only one set of protrusions into a mold assembly of a shoe last with a shoe cover attached and a side mold. By injection molding an appropriate sole material into this sole cavity, it is possible to obtain a desired shoe with excellent functionality and design value similar to a hand-molded shoe with a multi-layer sole. This is a manufacturing method that can be used.

[Brief explanation of the drawing]

Fig. 1 is a vertical sectional view showing a conventional embodiment;
3 is a side view of a shoe according to the present invention, FIG. 4 is a longitudinal sectional view showing an embodiment of the present invention, and FIG. 5 is a cross-sectional view of another embodiment of the present invention. The cross-sectional view and FIG. 6 are enlarged perspective views with some of the main parts cut away. 1... shoe last, 2... shoe cover, 3... suture part, 4... sole mold,
5... Protrusion, 6... Side mold, 7... First bottom cavity, 8...
Toe part, 9... Hollow part, 10... Outer sole, 11... Second bottom hollow part, 12... Wedge, 13... Tip part, 14
...edge.

Claims (1)

[Claims] 1. A shoe last to which a shoe cover is attached, a side mold that is assembled with the shoe last to form a cavity between the lower peripheral side of the shoe cover, and a mold that is slidably assembled on the inner surface of the side mold. A first sole material is injection molded into a first sole cavity formed by the lower surface of the last, the inner surface of the side mold, and the upper surface of the sole mold, and then the sole mold is molded downward. A second bottom material is injection molded into the second bottom cavity newly formed by moving to the bottom, and a multi-layer bottom made of rubber or synthetic resin of a different type or color is tightly attached to the cover. In a manufacturing method for shoes having a multi-layer sole, an upwardly facing inner edge and an outer edge of a predetermined position from the tread part to the heel of the upper surface of the sole mold, the inner surface of which has a shape that resembles the outer surface of the sole at that location. A projection is provided, and the lower surface of the shoe last and the upper surface of the sole mold are brought close to each other in a zone connecting the pair of projections, and the projection blocks the cavity formed by the lower surface of the shoe and the inner surface of the side mold. 1. A method for manufacturing shoes, comprising: forming a hollow part divided into two parts on a toe side and a heel side, one of which is a first bottom hollow part.