JP4210585B2 - shank - Google Patents

Description

  The present invention relates to a shank, and more particularly to a shank that is easy to assemble, has a low manufacturing cost, and has an auxiliary function for a shoe wearer's more comfortable walking.

  The sole is repeatedly bent and twisted by walking. For this reason, the soles are required to have rigidity such as bending strength and durability. Conventionally, in order to maintain the rigidity such as bending strength and durability and the shape of the shoe sole, or to reinforce the shoe, a leaf spring-shaped shank made of metal has been attached to the shoe sole. However, the metal shank is not necessarily desirable from the viewpoint of manufacturing time and cost. In addition, since July 1995, shoe manufacturers have also been obligated to manufacture products according to the Product Liability Act, the so-called PL Act, so that shoe soles such as metal protrusions and shank clasps can be mixed. There was also a demand to avoid using metallic materials that could damage the shank as the shank material.

  Therefore, for example, as shown in Patent Document 1, a shank using a non-metallic fiber-reinforced thermoplastic composite material has been proposed as a shank material. This shank uses a fiber reinforced thermoplastic composite material in which a thermoplastic resin is impregnated by hot melting and impregnating a reinforced fiber. By using this fiber reinforced thermoplastic composite material, a desired rigidity is obtained. I am doing so.

For example, as shown in Patent Document 2, a shank using a non-metallic thermoplastic resin as a shank material has also been proposed. In order to ensure the rigidity of this shank, the shank itself is devised to have a three-dimensional shape, and a plastic plate is superimposed on the shank so that the portion has a desired rigidity. .
JP 7-23803 JP-A-11-42103

However, the shank described in Patent Document 1 and Patent Document 2 has the following problems.
(1) The shank described in Patent Document 1 combines different materials of reinforced fiber and thermoplastic resin to create a fiber reinforced thermoplastic composite material, and the fiber reinforced thermoplastic composite material is formed into a desired shape by a press molding method. However, the press molding apparatus used here is expensive and requires a large initial investment because it requires a large space for installation. Moreover, since a burr | flash generate | occur | produces in a press process, the deburring process was needed and was not preferable from the surface of manufacturing efficiency. In addition, the cut burrs must be discarded, which is not preferable from the viewpoint of material utilization efficiency.
(2) The shank described in Patent Document 2 is formed by molding a thermoplastic transparent urethane resin sheet by a vacuum forming method. The shank has an arch-shaped three-dimensional shape, and rigidity is provided by providing a side wall on the arch. However, since different parts are bonded together, that is, a plastic plate is stacked and bonded to the shank, the assembly process becomes complicated and the cost is increased.
(3) The shanks described in both Patent Document 1 and Patent Document 2 are improved only by focusing on the structural part that maintains the rigidity of the shoe sole. There was a problem that no convenience was taken into account.

  An object of the present invention is to provide a shank that is easy to assemble, can be manufactured at low cost, and has an auxiliary function for more comfortable walking of a shoe wearer.

The present invention, in order to achieve the above object, a shank for use are sandwiched between the outsole and the upper for shape maintenance or reinforcement of the sole,
A heel portion corresponding to the position of the heel of the foot, an arch portion formed continuously with the heel portion and corresponding to the position of the arch of the foot, and formed continuously with the arch portion and extending from the arch to the toes. A forefoot portion corresponding to a position, and a side wall portion provided at a predetermined height so as to surround the periphery of the heel portion and the arch portion , and the lower surface of the forefoot portion is lower than the lower surface of the arch portion. Is provided with a step projecting downward, the tip is formed in a strip shape, and the thickness is formed to be thinner than the thickness of the collar portion and the arch portion, and the strip-like tip is formed on the outsole. The shank is provided by being fitted into and joined to a first recess provided on the upper surface of the shank.

In the above configuration, it is preferable that the flange portion is fitted and joined to a second recess provided on the upper surface of the outsole.

  The forefoot part is preferably formed in a strip shape, and is preferably formed thinner than the thickness of the heel part and the arch part.

  In addition, the arch portion may be formed using a thermoplastic resin that is partially different from other portions.

  As described above, according to the shank of the present invention, the shank is used by being sandwiched between the outsole or the midsole and the upper for maintaining or reinforcing the shape of the shoe sole, and corresponds to the position of the foot heel. A heel portion that is formed continuously with the heel portion and corresponds to the position of the arch of the foot, and a forefoot portion that is continuously formed with the arch portion and corresponds to a position from the arch to the toes of the foot. The shape of the shoe sole can be maintained or reinforced as it is, since the side wall portion provided at a predetermined height so as to surround the periphery of the heel portion and the arch portion is formed integrally. Since it is only necessary to adhere itself to the outsole or midsole and then the upper to adhere to the outsole or midsole, the shoe assembling process becomes easy. Moreover, since the side wall is provided, a more comfortable walking for the shoe wearer can be realized.

  Moreover, since it was made by injection molding using a thermoplastic resin, it can be manufactured at low cost. In addition, since the forefoot portion is formed in a strip shape and is formed thinner than the thickness of the heel portion and the arch portion, mechanical flexibility can be enhanced.

  In addition, since a part of the arch portion is molded using a thermoplastic resin different from the other portions, the elastic force can be further increased as compared with the case of a single thermoplastic resin.

  Hereinafter, a shank according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

  1 to 5 are views showing a shank 1 according to an embodiment of the present invention. FIG. 1 is an external view of the shank 1, FIG. 2 is a sectional view taken along the line aa in FIG. 1, and FIG. FIG. 3 is a sectional view taken along the line cc of FIG. 1, and FIG. 5 is a plan view of the shank 1.

  As shown in FIGS. 1 and 2, the shank 1 is integrally formed with a flange portion 11, an arch portion 12 formed continuously extending forward from the flange portion 11, and a tip of the arch portion 12. The forefoot part 13 is formed. In addition, the collar part 11 and the arch part 12 comprise the main-body part 10, and the side wall part 14 is shape | molded integrally with the main body around this main-body part 10. As shown in FIG. The side wall part 14 rises gently from the forefoot part 13 and has a shape that surrounds the periphery of the main body part 10 without any breaks. In addition, when materials such as Gore-Tex having a moisture permeable and waterproof function are used for the upper arch portion 12 and the side wall portion 14, which will be described later, a moisture-proof hole 15 for making the function work effectively even in a portion in contact with the shank 1. To 17 are provided.

  In the above configuration, as shown in FIG. 3, the heel part 11 is formed integrally with the side wall part 14 and has a three-dimensional shape with a slightly rounded cross section in accordance with the shape of the shoe wearer's heel. The flange portion 11 is fitted into and adhered to a recess 26 of the outsole 2 described later.

  As shown in FIG. 2, the arch portion 12 has a three-dimensional shape having a gentle arch (hereinafter referred to as a vertical arch) in the length direction in accordance with the arch of the shoe wearer. Further, as shown in FIG. 4, the arch portion 12 is formed integrally with the side wall portion 14 and has a three-dimensional shape having a gentle arch in the width direction (hereinafter referred to as a horizontal arch) substantially orthogonal to the vertical arch. It is also.

  As described above, the forefoot portion 13 is formed integrally with the arch portion 12 continuously. The front end portion has a shape of three strips. The forefoot 13 is fitted into a recess 25 of the outsole 2 which will be described later and is bonded thereto. As shown in FIG. 2, the lower surface of the forefoot portion 13 is formed with a step projecting slightly downward from the lower surface of the arch portion 12. This level | step difference is for latching and adhering to the hollow 25 of the outsole 2 mentioned later. Further, as shown in FIG. 2, the thickness of the forefoot portion 13 is formed thinner than the thickness of the arch portion 12 in order to increase its mechanical flexibility. In the present embodiment, the arch portion 12 has a thickness of about 3 mm, and the forefoot portion 13 has a thickness of about 1 mm.

  FIG. 5 is a view of the shank 1 as viewed from above, and the shape of the entire shoe sole is indicated by a one-dot chain line.

  The shank 1 configured as described above is formed of a thermoplastic polyurethane resin. The molding method will be described. First, pellets of thermoplastic polyurethane resin are put into a mixer and heated to a temperature at which the resin melts (approximately in the range of 200 ° C. to 250 ° C.). The molten resin is filled into an injection molding apparatus, and then the molten resin is injected into a metal mold that has been prepared in advance and hollowed into a female mold in accordance with the desired shank shape. Fill mold part with molten resin and seal. Since the metal mold is usually made of aluminum or the like having high thermal conductivity, the resin filled in the mold is cooled and solidified by cooling the mold by a technique such as water cooling. Since the thickness of the arch portion 12 is about 3 mm and the thickness of the forefoot portion 13 is about 1 mm, the shank 1 is completely cooled and solidified within a few seconds. In this way, the molding of the shank 1 is completed.

  Hereinafter, a shoe assembly process using the shank 1 of the present invention will be described with reference to FIGS. 6 and 7.

  First, as shown in FIG. 6, the above-described shank 1, the outsole 2 in which depressions 25 and 26 for fitting and bonding the front foot portion 13 and the heel portion 11 of the shank 1 are formed, and the shank 1 The upper 3 to be placed is prepared in advance. Next, an adhesive is applied to the depressions 25 and 26 of the outsole 2, and the shank 1 is placed on the outsole 2 so that the forefoot part 13 and the heel part 11 come to the place where the adhesive is applied. At this time, since the forefoot part 13 has sufficient mechanical flexibility as described above, the front foot part 13 is closely attached to the recess 25 of the outsole 2 without being pressed with a very strong force during bonding. . For this reason, an extra space | gap is not produced in the case of adhesion | attachment, but a firm joining state is obtained. The same applies to the recess 26. And an adhesive agent is apply | coated to the whole upper surface of the main-body part 10 of the shank 1, and the outer periphery of the upper 3 is inserted and adhere | attached inside the side wall part 14, and an assembly operation is completed. FIG. 7 is a view showing the appearance of the shoe assembled in this way.

  As shown in FIG. 8, a part of the shank 1 may be formed of different types of resin materials and integrated. For example, as shown in the figure, a part of the shank 1 made of a thermoplastic polyurethane resin may be formed of ABS (Acrylonitrile Butadiene Styrene) resins 21 and 22 and fitted and integrated. If the thickness is the same, the ABS resins 21 and 22 have a larger elastic force than the thermoplastic polyurethane resin, so that the integrated and integrated shank has a higher elastic force than the single thermoplastic polyurethane resin. Therefore, for example, in a sports shoe having a lot of jumping movements, a shank in which such a composite part is fitted and integrated may be used to adjust and optimize the elastic force. Note that the thicknesses of the parts to be fitted do not have to be the same, and an optimal thickness may be selected for each purpose. In addition, even if it is a different material, since all are resin, it can be easily fitted and integrated with a normal adhesive. Therefore, the feeling of discomfort due to joining is not given to the shoe wearer.

  As described above, in the shank 1 according to the present invention, the arch portion 12 has an arch-shaped three-dimensional shape, and covers a wide range of the sole including the heel portion 11, the arch portion 12, and the forefoot portion 13. The side wall portion 14 is provided around the main body portion 10 excluding the front foot portion 13 so as to support the portion.

  Since the bottom surface of the shank 1 is curved in an arch shape, a part of the load applied to the shank is dispersed in a direction perpendicular to the direction in which the bending stress is applied, thereby substantially reducing the bending stress applied to the shank 1. be able to.

  Most of the vertically distributed force is applied to the integrally formed side wall portion 14, and becomes shear stress on the side wall portion 14. The shear strength of the side wall portion 14 is very large compared to the bending strength. As a result, the side wall portion 14 serves as a core for maintaining the arch shape, and substantially increases the strength of the shank against bending stress. Therefore, even if the shank is manufactured using only the thermoplastic polyurethane resin, the desired rigidity is exhibited if the shank thickness is approximately 3 mm. Naturally, the problem of arch breakage does not occur. A part of the vertically distributed force acts as a tensile stress of the arch portion 12, but the tensile resistance is very large compared to the bending resistance, and there is no need to consider the deformation of the shank due to the tensile stress.

  Moreover, since the heel part 11 is made into a three-dimensional shape according to the shape of the shoe wearer's heel, when the landing is made by a movement such as jumping, the rounded shape of the heel is momentarily deformed and crushed. It absorbs and relaxes the shock transmitted to the knee etc., and quickly returns to its original shape. The shape of the collar portion 11 prompts a quicker return after the deformation of the collar.

  The shank 1 is sandwiched between the outsole 2 and the upper 3 that forms the upper part of the shoe, or between the upper 3 and a midsole (not shown) that is joined over the outsole 2. Since it is joined in the embedded state, the side wall portion 14 forms a side wall portion outside the upper 3. For this reason, for example, when the upper heel portion is made of a soft material such as cloth as in sports shoes, the wrinkle cannot be prevented. However, in the shank 1 of the present invention, the side wall portion 14 is not A function to prevent wobbling, that is, a heel cup function is exhibited.

  Further, the shank 1 has a vertical arch and a horizontal arch according to the shape of the human foot, and the arch portion 12 is provided with a side wall portion 14 of an appropriate height, so that it often occurs in the arch portion in conventional shoes. In addition to preventing excessive twisting, it is possible to reduce the play of the foot by pressing the side surface of the foot with the bending elastic force of the side wall. If the arch is prevented from twisting and the foot play is reduced, the posture of the shoe wearer will not be lost during walking or jumping, and the operation can be stabilized.

The shape of the right foot and the left foot of the shank 1 of the present invention is usually made into a substantially symmetrical three-dimensional shape, but is made asymmetric when necessary. For example, when one of the legs has an obstacle, the shape of the shank can be adjusted so as to reduce inconvenience due to the obstacle, and a walking assistance means can be provided.
In the present invention, the pellet-shaped thermoplastic polyurethane resin and the ABS resin have been described as examples of the material for forming the shank 1, but the same can be applied to other thermoplastic resins. The material shape does not need to be a pellet, and may be, for example, a powder. In addition, the melting process of these resins differs depending on the difference in the configuration of the injection molding apparatus, such as putting pellets directly into the cylinder of the injection molding apparatus and melting it by raising the temperature in the cylinder. It goes without saying that this is only an example. Further, the female mold portion of the mold may be manufactured using any conventional method.

  Further, the shanks 1 are provided with holes 15 to 17, and the holes 15 to 17 act to make the moisture permeability function of the upper 3 work more effectively. That is, when a material such as Gore-Tex having a moisture permeable waterproof function is used for the upper, moisture dissipated by the upper is diffused through a hole provided in the shank. Of course, the holes 15 to 17 may not be provided at all, and the number of holes and the place to be provided may be changed as necessary. Further, the shank 1 is not only completely covered with an outsole or the like, but may be commercialized with a part thereof exposed. In order to improve the design of the shoe, the exposed portion of the shank 1 may be processed such as an uneven pattern, or the upper portion of the side wall portion 14 may be processed into a smooth curved shape.

 Further, since the forefoot portion 13 is a so-called margin for adhering to the recess 25 of the outsole 2, it is desirable that the front foot portion 13 has mechanical flexibility. Therefore, the material thickness is reduced and the strip is formed. If the width per strip is narrowed, the flexibility is further increased. Therefore, the width and number of strips may be selected as necessary.

  As described above, since the shank of the present invention is manufactured using only a synthetic resin without using metal, the assembly of shoes can be performed by a simple process of bonding with an adhesive. Although the metal shank cannot be completely adhered to the outsole and may cause a shank, the shank of the present invention can be completely adhered by the adhesive, and therefore the shank does not occur. Since the shank manufacturing process is simple and the material is thermoplastic polyurethane resin, the manufacturing cost is low.

  The present invention relates to a shoe shank, and is a technical idea that can be applied regardless of whether it is a sports shoe or a walking shoe that is usually worn in daily life, and the scope of use of the present invention is very Wide.

It is a perspective view of the shank of this invention. It is the figure of the cross section cut | disconnected by FIG. It is the figure of the cross section cut | disconnected by FIG. 1b-b. It is the figure of the cross section cut | disconnected by FIG. 1c-c. It is a 1st bottom view of the shank of this invention. It is a disassembled perspective view of shoes. It is a side view of shoes appearance. It is a 2nd bottom view of the shank of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Shank 2 Outsole 3 Upper 10 Main body part 11 Saddle part 12 Arch part 13 Forefoot part 14 Side wall part 15 Hole 16 Hole 17 Hole 21 ABS resin 22 ABS resin

Claims (4)

A shank for use are sandwiched between the outsole and the upper for shape maintenance or reinforcement of the sole,
The heel corresponding to the position of the heel of the foot,
An arch part that is formed continuously with the buttocks and corresponds to the position of the arch of the foot,
A forefoot part that is formed continuously with the arch part and corresponds to a position from the arch to a toe;
A side wall portion provided at a predetermined height so as to surround the periphery of the heel portion and the arch portion;
Have
The forefoot part is provided with a step whose lower surface projects downward from the lower surface of the arch part, the tip is formed in a strip shape, and the thickness is formed thinner than the thickness of the heel part and the arch part. And
The shank characterized in that the strip-shaped tip is fitted and joined to a first recess provided on the upper surface of the outsole . 2. The shank according to claim 1, wherein the flange is fitted and joined to a second recess provided on an upper surface of the outsole. The shank according to claim 1 or 2 , wherein the heel part, the arch part, the forefoot part, and the side wall part are molded by an injection molding method using a thermoplastic resin. The shank according to any one of claims 1 to 3 , wherein a part of the arch portion is molded using a thermoplastic resin different from the other part.

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