Sole series and sole manufacturing method

Abstract

To reduce an initial investment cost in manufacturing a sole series including a plurality of types of soles.SOLUTION: Each of midsoles 2A-2C of a plurality of types of soles 1A-1C that constitutes a sole series S includes an upper midsole 4 and a corresponding one of lower midsoles 5A-5C. Each of the plurality of types of soles 1A-1C is configured such that, in a non-wearing state, while the sole contacts the ground surface G at an intersection C, a heel region does not contact the ground surface G. While the upper midsoles 4 of the plurality of types of soles 1A-1C are formed to have the same shape, the lower midsoles 5A-5C of the plurality of types of soles 1A-1C are formed to have different shapes such that an angle α between a straight line T and the ground surface G is a forwardly descending angle that differs between the soles 1A-1C.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a sole series and a method for manufacturing a sole. [Background technology]

[0002] There are three types of running styles, forefoot running, midfoot running, and heel strike running, which have different landing patterns. In recent years, it has been thought that forefoot running or midfoot running is more effective for running efficiently and quickly.

[0003] However, forefoot and midfoot running are not easy for everyone to perform, and there is a risk that they may promote muscle fatigue around the calves, so in middle and long distance running, it is not easy to maintain a forefoot or midfoot running style until the end.

[0004] In recent years, various shoes have been proposed that encourage efficient and fast running by providing soles that encourage forefoot or midfoot running (see, for example, Patent Document 1 listed below).

[0005] Patent Document 1 discloses shoes with a sole in which the thickness of the midpoint in the front-to-rear direction is thicker than the thickness of the heel or toe, and the underside of the rear foot is inclined upward at the rear. With such shoes, the forefoot or midfoot easily contacts the ground when landing, while the heel does not easily contact the ground, encouraging the wearer to run with a forefoot or midfoot sprint. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2020-163084 Summary of the Invention [Problem to be solved by the invention]

[0007] Incidentally, the angle of the foot when landing varies from person to person, and the angle of the foot that the sole should encourage to run at in order to run efficiently and quickly also varies from person to person. For this reason, it is preferable to have multiple types of soles available for running efficiently and quickly.

[0008] On the other hand, the sole of a shoe for running efficiently and quickly must be easily elastically deformable, have high flexural rigidity, and be lightweight. In particular, the midsole must be low in hardness, highly resilient, and lightweight.

[0009] However, forming a low-hardness, high-rebound, and lightweight midsole requires the use of expensive molds, and therefore, as mentioned above, in order to prepare multiple types of soles (develop variations), multiple expensive molds must be prepared, which increases the initial investment, making it difficult to develop variations.

[0010] The present invention has been made in view of the above points, and its object is to reduce the initial investment cost when manufacturing a sole series consisting of multiple types of soles. [Means for solving the problem]

[0011] In order to achieve the above object, the first aspect of the present invention is A sole series consisting of multiple types of soles each having a midsole extending from a heel portion to a toe portion and having an upper surface that serves as a sole support surface that supports the sole of a shoe wearer, Each of the midsoles of the plurality of types of soles is an upper midsole made of an elastic material extending from the heel portion to the toe portion; a lower midsole having an upper surface that conforms to the lower surface of the upper midsole and that is made of an elastic material and extends from the heel portion to the toe portion; In each of the above soles, The position of the rear end on the sole support surface is P0. The position of the most distal end on the sole support surface is P100, The line connecting the above position P0 and the above position P100 is Ls. A curve connecting the position P0 and the position P100 along the sole support surface is denoted by Lc. The length of the above curve Lc is L, The position on the curve Lc that is 0.15L away from the position P0 is P15. The position on the curve Lc that is 0.45L away from the position P0 is P45. P68 is the position on the curve Lc that is 0.68L away from the position P0. The intersection of the lower surface and a line perpendicular to the line Ls passing through the position P45 is C, When the line connecting the above position P15 and the above position P68 is T, The plurality of types of soles are configured so that, when not worn, they come into contact with the ground at the intersection point C, while their heel portions do not come into contact with the ground, The upper midsoles of the plurality of types of soles are formed to have the same shape, The lower midsoles of the plurality of types of soles are formed in different shapes so that the angle formed by the straight line T and the ground is a different angle downward toward the front among the plurality of types of soles. It is characterized by the following.

[0012] The first type of sole series is composed of multiple types of soles, and each of the multiple types of soles is configured so that when not worn, it touches the ground at a position (intersection point C) corresponding to the plantar arch of the wearer's foot, while the heel does not touch the ground.Furthermore, the inclination angle of the sole support surface (the angle between line T and the ground) is configured to be a downward angle to the front.With this configuration, each of the multiple types of soles that make up the sole series makes it difficult for the heel to touch the ground when landing, while making it easier for the forefoot or midfoot to touch the ground.In other words, the first type of sole series can provide multiple types of soles that encourage the wearer to run using a forefoot or midfoot sprinting style.

[0013] In the first embodiment, the midsole has a two-layer structure, with the upper midsole having the same shape across multiple sole types (only one model is prepared), while the lower midsole has a different shape across multiple sole types (multiple models are prepared), thereby providing multiple sole types with different inclination angles of the sole support surface (the angle between the line T and the ground). This configuration reduces the number of molds required to form the midsole when manufacturing multiple sole types. Therefore, the first embodiment reduces initial investment costs when manufacturing a sole series consisting of multiple soles that can encourage the wearer to run using a forefoot or midfoot running style.

[0014] The second form is the first form of the Sole series, In each of the above soles, The intersection of the line perpendicular to the line Ls passing through the position P45 and the lower surface of the upper midsole is P45'. The intersection of the line perpendicular to the line Ls passing through the position P68 and the lower surface of the upper midsole is P68'. When the line connecting the position P45' and the position P68' is T', The lower midsoles of the plurality of types of soles are formed such that the angle formed by the straight line T' and the ground is a different downward angle between the plurality of types of soles. It is characterized by the following.

[0015] In the second embodiment, the multiple types of soles are configured so that when not worn, the angle of the midfoot region of the boundary between the upper midsole and the lower midsole (the angle between the line T' and the ground) is downward toward the front. This configuration ensures that all of the multiple types of soles that make up the sole series promote forward movement of the center of gravity after landing. In other words, the second embodiment of the sole series provides multiple types of soles that allow the wearer to run smoothly using either a forefoot or midfoot sprint.

[0016] In the second embodiment, the shape of the lower midsole is varied among the various types of soles, thereby providing various types of soles with different angles (the angle between the line T' and the ground) in the midfoot region of the boundary surface between the upper midsole and the lower midsole. This configuration makes it possible to provide a wide variety of soles that provide different sensations when stepping in after landing.

[0017] The third aspect is the first or second aspect, At least one of the lower midsoles of the plurality of types of soles has a front end located forward of the front end of the upper midsole, and an upper surface of the front end located forward of the front end of the upper midsole constitutes the front end of the sole support surface. It is characterized by the following.

[0018] In a third embodiment, at least one of the lower midsoles of the multiple types of soles is configured as a long lower midsole whose front end is located further forward than the front end of the upper midsole. This configuration allows for the provision of soles of different sizes by using upper midsoles of the same shape, but using a lower midsole whose front end is not located further forward than the front end of the upper midsole, and the long lower midsole. In other words, in the third embodiment, by using upper midsoles of the same shape and changing the type of lower midsole, it is possible to provide soles that differ not only in the inclination angle of the sole support surface (the angle between the line T and the ground) but also in size. Therefore, the third embodiment further reduces the initial investment cost when producing a sole series consisting of multiple types of soles that can encourage the wearer to run using a forefoot sprint or a midfoot sprint.

[0019] The fourth form is the third form, The above long lower midsole is When the position on the curve Lc that is 0.90L away from the position P0 is P90, The position P90 is configured to be on the upper surface of the upper midsole. It is characterized by the following.

[0020] In the fourth form, the long lower midsole is configured so that the boundary between the upper midsole and the long lower midsole is located forward of position P90 on the sole support surface (upper surface) of the sole. Normally, the wearer's foot rests on the area rearward of position P90 on the sole support surface of the sole, and the wearer's foot does not rest on the area on the sole support surface from position P90 to the forefront position P100. Therefore, by configuring the sole as described above, the wearer's foot does not rest on the boundary between the upper midsole and the long lower midsole when wearing the sole, and therefore does not feel any discomfort.

[0021] The fifth form is the second form, each of the plurality of types of soles includes a plate made of an elastic material having a higher hardness than the upper midsole and provided between the upper midsole and the lower midsole; The plates of the plurality of types of soles are formed in the same shape. It is characterized by the following.

[0022] In the fifth embodiment, the same upper midsole shape is used across multiple sole types, allowing the same plate shape to be used as well. This further reduces the initial investment cost when manufacturing a sole series made up of multiple soles that encourage the wearer to run with either a forefoot or midfoot sprint style.

[0023] The sixth form is A method for manufacturing a sole having a midsole that extends from a heel portion to a toe portion and has an upper surface that serves as a sole support surface that supports the sole of a shoe wearer, The sole is one of the soles constituting the sole series described in claim 1, A selection step is provided for selecting one of the lower midsoles from a plurality of types of lower midsoles having different shapes. It is characterized by the following.

[0024] According to the sixth embodiment, it is possible to reduce the initial investment cost when manufacturing a sole series consisting of a plurality of types of soles. [Effects of the Invention]

[0025] As described above, according to the present invention, it is possible to reduce the initial investment cost when manufacturing a sole series consisting of a plurality of types of soles. [Brief explanation of the drawings]

[0026] [Figure 1] FIG. 1 is a perspective view of a sole series S according to a first embodiment. [Figure 2] FIG. 2 is an exploded perspective view of the sole 1A of FIG. [Figure 3] FIG. 3 is an exploded perspective view of the sole 1B of FIG. [Figure 4] FIG. 4 is an exploded perspective view of the sole 1C of FIG. [Figure 5] FIG. 5 is a cross-sectional view of the sole 1A of FIG. 1 as viewed from the outer instep side. [Figure 6] FIG. 6 is a cross-sectional view of the sole 1B of FIG. 1 as viewed from the outer instep side. [Figure 7] FIG. 7 is a cross-sectional view of the sole 1C of FIG. 1 as viewed from the outer instep side. [Figure 8] FIG. 8 is a diagram showing the relationship between the inclination angle of the sole support surface and the foot angle. [Figure 9] FIG. 9 is a partially enlarged cross-sectional view of the vicinity of the forefoot portion of the sole 1D of the sole series S of the second embodiment, viewed from the instep side. DETAILED DESCRIPTION OF THE INVENTION

[0027] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The following embodiments are merely preferred examples in nature and are not intended to limit the scope of the present invention, its applications, or its uses.

[0028] First Embodiment of the Invention 1 to 7 are diagrams illustrating the configuration of a sole series S according to a first embodiment of the present invention, showing only the left foot side portions of all or any of the three types of soles 1A to 1C that make up the sole series S. Note that FIGS. 5 to 7 are cross-sectional views of the left foot side portions of the soles 1A to 1C as viewed from the instep side, with hatching omitted for ease of explanation. While the soles 1A to 1C can be applied to sports shoes worn by athletes of various sports, the following describes an example in which they are applied to shoes SA to SC for middle- to long-distance running.

[0029] Shoes SA to SC are composed of a left foot side portion shown in Figs. 5 to 7 and a right foot side portion (not shown) that is symmetrical to the left foot side portion. Shoes SA to SC each include soles 1A to 1C and uppers (vamp portions) U that are fixed thereon by gluing or sewing. Although only the outline of upper U is shown by the two-dot chain line in Figs. 5 to 7, it may have any shape as long as it can cover the instep of the shoe wearer. In this embodiment 1, the uppers U of shoes SA to SC are formed in the same shape.

[0030] In the following description, only the left foot side portion of the soles 1A to 1C of the sole series S shown in FIGS. 5 to 7 will be described, and a description of the right foot side portion will be omitted.

[0031] In the following description, the terms "upper" (top) and "lower" (bottom) refer to the vertical positional relationship of the soles 1A to 1C. The terms "front" (front side) and "rear" (rear side) refer to the longitudinal positional relationship of the soles 1A to 1C. The terms "medial side" and "lateral side" refer to the transverse positional relationship of the soles 1A to 1C.

[0032] -Sole Series S Composition- 1, in this embodiment 1, the sole series S is made up of three types of soles 1A to 1C that aim to encourage the wearer to run using a forefoot sprint style or a midfoot sprint style. As will be described in detail later, the soles 1A to 1C are configured so that the inclination angle of the sole support surface (upper surface) differs.

[0033] [Common configuration for soles 1A to 1C] As shown in FIGS. 2 to 7, each of the soles 1A to 1C includes a midsole 2A to 2C, an outsole 3A to 3C, and a plate 6. As shown in FIGS.

[0034] The midsoles 2A to 2C are provided so as to extend from the rear end to the front end of the soles 1A to 1C (from the heel to the toe). The midsoles 2A to 2C are formed of a soft elastic material that is lower in hardness than the outsoles 3A to 3C described below. Specifically, suitable materials for the midsoles 2A to 2C include thermoplastic synthetic resins such as ethylene-vinyl acetate copolymer (EVA) and foams thereof, thermosetting resins such as polyurethane (PU) and foams thereof, and rubber materials such as butadiene rubber and chloroprene rubber and foams thereof. However, the materials for the midsoles 2A to 2C are not limited to those mentioned above.

[0035] The midsoles 2A to 2C are separated into upper and lower parts. Specifically, the midsoles 2A to 2C each have an upper midsole 4 and lower midsoles 5A to 5C provided below the upper midsole 4.

[0036] The upper midsole 4 is provided over the entire range of the soles 1A-1C, from the rear end to the front end in the front-to-rear direction (from the heel to the toe), and from the medial instep end to the lateral instep end in the foot width direction. The upper surface of the upper midsole 4 is formed in a curved shape to fit the sole of the shoe wearer's foot, and serves as a sole support surface that supports the sole of the shoe wearer's foot via an insole (not shown). An upper U is fixed to the upper surface of the upper midsole 4.

[0037] As shown in Figures 5 to 7, a groove 7 for accommodating a plate 6, which will be described later, is formed in the lower surface of the upper midsole 4. The groove 7 is formed by recessing a portion of the lower surface of the upper midsole 4 upward. The groove 7 is formed at a position, size, and depth corresponding to the plate 6 so that the lower surface of the plate 6 is flush with the lower surface of the upper midsole 4 when the plate 6 is fitted.

[0038] The lower midsoles 5A to 5C are provided over the entire range of the soles 1A to 1C, from the rear end to the front end in the front-to-rear direction (from the heel to the toe), and from the medial to lateral instep ends in the foot width direction. The upper surfaces of the lower midsoles 5A to 5C are formed in a curved shape that fits along the underside of the upper midsole 4, and are fixed to the underside of the upper midsole 4 and the underside of the plate 6 (described later) with an adhesive or the like.

[0039] The upper midsole 4 and the lower midsoles 5A to 5C are made of the same elastic material. However, the upper midsole 4 and the lower midsoles 5A to 5C may be made of elastic materials with different hardnesses.

[0040] The outsoles 3A-3C are provided over the entire range of the soles 1A-1C, from the rear end to the front end in the longitudinal direction (from the heel to the toe), and from the medial instep end to the lateral instep end in the width direction of the foot. The outsoles 3A-3C are made of a hard elastic material that is harder than the midsoles 2A-2C. Specifically, suitable materials for the outsoles 3A-3C include thermoplastic resins such as ethylene-vinyl acetate copolymer (EVA), thermosetting resins such as polyurethane (PU), or rubber materials such as butadiene rubber or chloroprene rubber. However, the materials for the outsoles 3A-3C are not limited to those mentioned above.

[0041] The upper surfaces of the outsoles 3A to 3C are formed in a curved shape that fits along the lower surfaces of the lower midsoles 5A to 5C, and are fixed to the lower surfaces of the lower midsoles 5A to 5C with an adhesive or the like. The lower surfaces of the outsoles 3A to 3C form the contact surfaces that come into contact with the ground G during running.

[0042] The plate 6 is provided in a range from the rear end to the front end of the soles 1A to 1C in the front-to-back direction (from the heel to the toe), and from the medial instep end to the lateral instep end of the soles 1A to 1C in the foot width direction, but the length of the plate 6 in both the front-to-back direction and the foot width direction is shorter than that of the midsoles 2A to 2C and the outsoles 3A to 3C.

[0043] The plate 6 is formed in a thin plate shape from an elastic material that is harder than the midsoles 2A to 2C. Specifically, suitable materials for the plate 6 include thermoplastic synthetic resins such as thermoplastic polyurethane (TPU), polyamide elastomer (PAE), polyamide, and the like, as well as resins to which fibrous materials such as glass fiber and carbon fiber have been added. The plate 6 is an injection-molded product obtained by injection molding the above-mentioned thermoplastic resin materials (including those to which fibrous materials have been added). The flexural modulus of the plate 6 is preferably set to, for example, 100 MPa to 400 MPa (specifically, 390 MPa).

[0044] The plate 6 may be a heat-press molded product obtained by heat-press molding a thermosetting fiber-reinforced plastic material, or may be a heat-press molded product obtained by heat-press molding a thermoplastic fiber-reinforced plastic material or a resin sheet material.

[0045] The plate 6 has a flat base plate 6a and a plurality of ribs 6b protruding upward from the upper surface of the base plate 6a. The plate 6 is housed in the recessed groove 7 of the upper midsole 4, and its lower surface is fixed to the upper surfaces of the lower midsoles 5A to 5C with an adhesive or the like. With this configuration, the plate 6 is sandwiched between the upper midsole 4 and the lower midsoles 5A to 5C.

[0046] The upper midsoles 4 of the soles 1A to 1C are formed in the same shape. Also, the plates 6 of the soles 1A to 1C are formed in the same shape. In other words, when manufacturing the three types of soles 1A to 1C that make up the sole series S, only one model of each of the upper midsoles 4 and plates 6 is prepared.

[0047] [Different sole configurations for 1A to 1C] In the soles 1A to 1C, the lower midsoles 5A to 5C and the outsoles 3A to 3C are formed in different shapes. Specifically, the three types of soles 1A to 1C use upper midsoles 4 of the same shape, but the shapes of the lower midsoles 5A to 5C are different among the soles 1A to 1C so that the inclination angles of the sole-supporting surfaces (upper surfaces of the soles 1A to 1C) are different. The outsoles 3A to 3C are formed in shapes that fit the lower surfaces of the lower midsoles 5A to 5C, which have different shapes, and therefore have different shapes. Note that while the overall shapes of the lower midsoles 5A to 5C are different among the soles 1A to 1C, the shapes of the upper surfaces are formed in the same shape because they abut against the lower surfaces of the upper midsoles 4, which have the same shape.

[0048] (Design intent of lower midsole 5A~5C) The differences in shape (design intent) of the lower midsoles 5A to 5C will be described in detail below. As shown in Figs. 5 to 7, the various parts of the soles 1A to 1C are defined as follows. P1: The position of the rearmost point on the sole support surface P100: The most extreme position on the sole support surface Ls: A straight line connecting positions P0 and P100 Lc: A curve along the sole support surface connecting positions P0 and P100 L: Length of curve Lc P15: A position on curve Lc that is 0.15L away from position P0 P45: A position on curve Lc at a distance (path) of 0.45L from position P0 P68: The distance (path) from position P0 on curve Lc is 0.68L P45': Intersection point of a line perpendicular to the line Ls passing through position P45 and the bottom surface of the upper midsole P68': Intersection point of the line perpendicular to the line Ls passing through the position P68 and the bottom surface of the upper midsole C: Intersection of the line perpendicular to the line Ls passing through position P45 and the bottom surface of the sole T: A straight line connecting positions P15 and P68 T': A straight line connecting positions P45' and P68'

[0049] In the sole series S, the lower midsoles 5A-5C are configured so that, when shoes SA-SC are not being worn, all of the soles 1A-1C come into contact with the ground G at intersection C (a position corresponding to the plantar arch of the wearer's foot), while the heel does not. Furthermore, the angle α (the inclination angle α of the sole support surface) between the line T and the ground G of each sole 1A-1C is a downward angle. This configuration makes it difficult for the heel of each of the soles 1A-1C that make up the sole series S to touch the ground when landing, while making it easier for the forefoot or midfoot to touch the ground. Therefore, all of the soles 1A-1C of the sole series S can encourage the wearer to run using a forefoot or midfoot sprint.

[0050] In addition, with the Sole Series S, the angle of the foot when landing varies from person to person, even when running with the same forefoot running style. To encourage a variety of people to run with a forefoot or midfoot running style without feeling uncomfortable, three types of soles 1A to 1C are provided (designed) with different inclination angles α of the sole support surface (top surface).

[0051] Therefore, the lower midsoles 5A to 5C used in the three types of soles 1A to 1C are formed in different shapes so that the angle α between the line T and the ground G (the inclination angle α of the sole support surface) is a different forward downward angle between the soles 1A to 1C.

[0052] Specifically, the angle α between the line T and the ground G (the inclination angle α of the sole support surface) is between 5° and 16°. In this embodiment 1, the lower midsoles 5A to 5C are designed so that the angle α of the sole 1A is 5°, the angle α of the sole 1B is 8°, and the angle α of the sole 1C is 11°. If the angle α between the line T and the ground G (the inclination angle α of the sole support surface) is less than 5°, the angle will deviate greatly from the angle of the foot of a wearer who runs with a forefoot stance, which may result in an inability to stably support the foot of a wearer who runs with a forefoot stance. If the angle α between the line T and the ground G (the inclination angle α of the sole support surface) is greater than 16°, the wearer's foot will be tilted too far forward, which may result in the wearer being unable to kick the ground G powerfully and thus being unable to run efficiently and quickly. Therefore, the angle α between the straight line T and the ground G (the inclination angle α of the sole support surface) is set to be equal to or greater than 5° and equal to or less than 16°.

[0053] Furthermore, in this embodiment 1, the lower midsoles 5A-5C are configured so that when the shoes SA-SC are not being worn, the angle α' between the line T' and the ground G in each of the soles 1A-1C (the angle α' in the midfoot region of the boundary surface between the upper midsole 4 and the lower midsole 5A-5C) is angled downward toward the front. With this configuration, all three types of soles 1A-1C that make up the sole series S facilitate the wearer's center of gravity to shift smoothly forward when stepping in after landing.

[0054] Furthermore, in the sole series S of this embodiment 1, the angle of the foot when stepping off after landing also varies from person to person, just like when landing, so in order to encourage a forward movement of the center of gravity for a variety of people without discomfort, the lower midsoles 5A to 5C are formed (designed) so that the angle α' of the midfoot region of the boundary surface between the upper midsole 4 and the lower midsoles 5A to 5C is a different downward angle toward the front among the three types of soles 1A to 1C.

[0055] Specifically, the lower midsoles 5A-5C are designed so that the angle α' between the line T' and the ground G (the angle α' in the midfoot region of the boundary surface between the upper midsole 4 and the lower midsoles 5A-5C) is greater than 0° and not greater than 45°. If the angle α' between the line T' and the ground G is less than 0° (horizontal or a front-upward angle), the center of gravity may not shift smoothly when stepping forward after landing, which may make it difficult to move forward. Furthermore, if the angle α' between the line T' and the ground G is greater than 45°, the plate 6 may thrust upward against the wearer's foot when stepping forward after landing, which may cause pain to the wearer. Therefore, the angle α' between the line T' and the ground G (the angle α' in the midfoot region of the boundary surface between the upper midsole 4 and the lower midsoles 5A-5C) is set to be greater than 0° and not greater than 45°.

[0056] (Relationship between the angle of the sole support surface and the angle of the wearer's foot) As described above, in the sole series S, the three types of soles 1A to 1C use a common upper midsole 4, while using lower midsoles 5A to 5C with different shapes, making it possible to provide three types of soles 1A to 1C with different sole support surface angles α (the angle α between the straight line T and the ground G).

[0057] According to this sole series S, as shown in FIG. 8, for a low-type person whose foot F1 angle (the angle between the sole B and the ground G) at landing is small, low-type shoes SA with a small sole support surface angle α (the angle α between the line T and the ground G) are most suitable. When shoes SA are selected, the sole 1A encourages the person to run efficiently and quickly using a forefoot or midfoot running style. Even if a low-type person selects mid-type shoes SB with a medium sole support surface angle α, the sole 1B encourages the person to run efficiently and quickly using a forefoot or midfoot running style, but the effect is less than that of shoes SA. This is because the sole support surface angle α of sole 1B is slightly larger than the angle of the foot F1 of a low-type person, which may result in unnatural running movements. Furthermore, it is not appropriate for a Low type person to select a High type shoe SC with a large sole support surface angle α, because the angle α of the sole support surface of the sole 1C is too large compared to the angle of the foot F1 of a Low type person, which results in a large deviation from normal running movements and may cause the wearer to feel very uncomfortable when running.

[0058] For Mid-type people with a medium angle of the foot F2 at the time of landing, Mid-type shoes SB with a medium sole support surface angle α are most suitable. When shoes SB are selected, the sole 1B encourages efficient and fast running using a forefoot or midfoot sprinting style. Even if Mid-type people select Low-type shoes SA with a small sole support surface angle α or High-type shoes SC with a large sole support surface angle α, the sole 1A or sole 1C will encourage efficient and fast running using a forefoot or midfoot sprinting style, but the effect will be inferior to that of shoes SB. This is because the sole support surface angle α of sole 1A or sole 1C is smaller or larger than the angle of the foot F2 of Mid-type people, which may result in unnatural running movements.

[0059] For High-type individuals with a large foot F3 angle at landing, High-type shoes SC, with a large sole support surface angle α, are most suitable. When selecting shoes SC, the sole 1C encourages efficient and fast running using a forefoot or midfoot gait. Even if a High-type individual selects Mid-type shoes SB with a medium sole support surface angle α, the sole 1B encourages efficient and fast running using a forefoot or midfoot gait, but the effect is inferior to that of shoes SC. This is because the sole support surface angle α of the sole 1B is slightly smaller than the angle of the foot F3 of a High-type individual, resulting in a period of time when the foot F3 is not supported by the sole 1B during step-in after landing. Furthermore, it is not appropriate for a High-type individual to select Low-type shoes SA, with a small sole support surface angle α, because the sole support surface angle α of the sole 1A is too small compared to the angle of the foot F3 of a High-type individual, and the sole 1A does not encourage running using a forefoot or midfoot gait.

[0060] -Method of manufacturing soles 1A to 1C- Next, a method for manufacturing the soles 1A to 1C that constitute the sole series S will be described.

[0061] First, the components of the soles 1A to 1C are produced (component production process). Specifically, one type of upper midsole 4 is produced using one type of mold, three types of lower midsoles 5A to 5C are produced using three types of molds, three types of outsoles 3A to 3C are produced using three types of molds, and one type of plate 6 is produced using one type of mold.

[0062] Next, components are selected according to the object to be manufactured (selection process). Specifically, when manufacturing sole 1A, lower midsole 5A is selected from three types of lower midsoles 5A to 5C, and outsole 3A is selected from three types of outsoles 3A to 3C. When manufacturing sole 1B, lower midsole 5B is selected from three types of lower midsoles 5A to 5C, and outsole 3B is selected from three types of outsoles 3A to 3C. When manufacturing sole 1C, lower midsole 5C is selected from three types of lower midsoles 5A to 5C, and outsole 3C is selected from three types of outsoles 3A to 3C.

[0063] Then, soles 1A-1C are assembled by stacking components according to the object to be manufactured one above the other and bonding them together with adhesives or the like (assembly process). Specifically, the upper midsole 4, plate 6, lower midsole 5A, and outsole 3A are stacked in this order from top to bottom and bonded together with adhesives or the like to assemble sole 1A. The upper midsole 4, plate 6, lower midsole 5B, and outsole 3B are stacked in this order from top to bottom and bonded together with adhesives or the like to assemble sole 1B. The upper midsole 4, plate 6, lower midsole 5C, and outsole 3C are stacked in this order from top to bottom and bonded together with adhesives or the like to assemble sole 1C.

[0064] As described above, the soles 1A to 1C constituting the sole series S are manufactured by carrying out the component part manufacturing step, the selection step, and the assembly step.

[0065] -Effects of the first embodiment- As described above, the sole series S of the first embodiment comprises multiple types of soles 1A-1C (three types in the first embodiment). Each of the multiple types of soles 1A-1C is configured so that, when not worn, it contacts the ground G at intersection C (a position corresponding to the plantar arch of the wearer's foot), while the heel does not contact the ground G. Furthermore, the inclination angle α of the sole support surface (the angle α between the line T and the ground G) is angled downward toward the front. This configuration makes it difficult for the heel to contact the ground when landing, while making it easier for the forefoot or midfoot to contact the ground. In other words, the sole series S of the first embodiment can provide multiple types of soles 1A-1C that encourage the wearer to run using a forefoot or midfoot sprinting style.

[0066] Furthermore, in this embodiment 1, the midsoles 2A-2C have a two-layer structure. The upper midsole 4 has the same shape across the multiple types of soles 1A-1C (only one model is prepared), while the lower midsoles 5A-5C have different shapes across the multiple types of soles 1A-1C (multiple models are prepared). This allows for the provision of multiple types of soles 1A-1C with different inclination angles α (the angle α between the line T and the ground) of the sole support surface. This configuration reduces the number of molds required to form the midsoles 2A-2C when manufacturing multiple types of soles 1A-1C (reducing the number from six types, three for each upper and lower, to four). Therefore, this embodiment 1 reduces the initial investment cost when manufacturing a sole series S made up of multiple types of soles 1A-1C that encourage the wearer to run using a forefoot sprint style or a midfoot sprint style.

[0067] Furthermore, in this embodiment 1, the multiple types of soles 1A-1C are configured so that when not worn, the angle α' (the angle α' between the line T' and the ground G) of the midfoot region of the boundary surface between the upper midsole 4 and the lower midsole 5A-5C is a forward-sloping angle. With this configuration, all of the multiple types of soles 1A-1C that make up the sole series S promote forward shift of the center of gravity after landing. In other words, the sole series S of this embodiment 1 can provide multiple types of soles 1A-1C that allow the wearer to run smoothly using a forefoot sprinting style or a midfoot sprinting style.

[0068] Furthermore, in this embodiment 1, by varying the shapes of the lower midsoles 5A to 5C among the plurality of types of soles 1A to 1C, the plurality of types of soles 1A to 1C are provided in which the angle α' (the angle α' between the line T' and the ground G) of the midfoot region of the boundary surface between the upper midsole 4 and the lower midsole 5A to 5C is different from one another. With this configuration, it is possible to provide a wide variety of soles 1A to 1C that provide different feel when stepping in after landing.

[0069] Furthermore, in this embodiment 1, the same shape of upper midsole 4 is used across the multiple types of soles 1A to 1C, and therefore the same shape of plate 6 can also be used. This makes it possible to reduce the number of types of molds that need to be prepared for forming the plate 6 when manufacturing the multiple types of soles 1A to 1C (reducing from three to one). Therefore, according to this embodiment 1, it is possible to further reduce the initial investment cost when manufacturing a sole series S made up of multiple types of soles 1A to 1C that can encourage the wearer to run using a forefoot sprint style or a midfoot sprint style.

[0070] Furthermore, in the first embodiment, the manufacturing method of the soles 1A-1C that make up the sole series S includes a selection step of selecting one lower midsole 5A, 5B, 5C from among multiple types of lower midsoles 5A-5C that differ from one another in shape, and in the selection step, one of the lower midsoles 5A-5C to be used in manufacturing the soles 1A-1C is selected from among the lower midsoles 5A-5C. However, since the same shape is used for the upper midsoles 4 among the soles 1A-1C, there is no need to select one, and there is also no need to prepare multiple types of molds to manufacture multiple types of upper midsoles 4. Therefore, the manufacturing method of the soles 1A-1C of the first embodiment can reduce the initial investment cost when manufacturing the sole series S made up of multiple types of soles 1A-1C.

[0071] Second Embodiment of the Invention The sole series S of the second embodiment is composed of soles 1A to 1C that constitute the sole series S of the first embodiment and soles 1D to 1F that are one size larger than the soles 1A to 1C. The soles 1A to 1C are configured in the same manner as in the first embodiment, and therefore a description thereof will be omitted.

[0072] Each of the soles 1D to 1F includes a midsole 2D to 2F, an outsole 3D to 3F, and a plate 6. Each of the midsole 2D to 2F includes an upper midsole 4 and a lower midsole 5D to 5F provided below the upper midsole 4.

[0073] As shown in FIG. 9, sole 1D is configured substantially similarly to sole 1A, except that lower midsole 5D is longer in the front-to-back direction than lower midsole 5A of sole 1A. Sole 1E is configured substantially similarly to sole 1B, except that lower midsole 5E is longer in the front-to-back direction than lower midsole 5B of sole 1B. Sole 1F is configured substantially similarly to sole 1C, except that lower midsole 5F is longer in the front-to-back direction than lower midsole 5C of sole 1C. In other words, soles 1D to 1F are used for shoes SD to SF, which are one size larger than shoes SA to SC.

[0074] 9, the lower midsole 5D of the sole 1D is configured so that its front end is located further forward than the front end of the upper midsole 4, and is configured as a longer lower midsole than the lower midsole 5A of the sole 1A. The upper surface of the front end of the lower midsole 5D, which is located further forward than the front end of the upper midsole 4, forms the front end of the sole support surface of the sole 1A. In other words, the sole support surface of the sole 1D is formed by the upper surface of the upper midsole 4 and the upper surface of the front end of the lower midsole 5D.

[0075] Furthermore, the lower midsole 5D of the sole 1D is configured such that, when a position P90 is a position on the curve Lc whose distance (path length) from position P0 is 0.90L, position P90 is on the upper surface of the upper midsole 4. In other words, in the sole 1D, the long lower midsole 5D is configured such that the boundary between the upper midsole 4 and the long lower midsole 5D is located forward of position P90 on the sole support surface (upper surface).

[0076] Like the lower midsole 5D of sole 1D, the lower midsoles 5E and 5F of soles 1E and 1F are configured so that their front ends are located further forward than the front end of the upper midsole 4, making them longer lower midsoles than the lower midsoles 5B and 5C of soles 1B and 1C. Furthermore, the upper surfaces of the front ends of the lower midsoles 5E and 5F, which are located further forward than the front end of the upper midsole 4, form the front end of the sole support surface of soles 1B and 1C, respectively. In other words, the sole support surface of soles 1E and 1F is formed by the upper surface of the upper midsole 4 and the upper surfaces of the front ends of the lower midsoles 5E and 5F.

[0077] Similarly to the lower midsole 5D of the sole 1D, the lower midsoles 5E, 5F of the soles 1E, 1F are configured so that position P90 is on the upper surface of the upper midsole 4. That is, in the soles 1E, 1F, the long lower midsoles 5E, 5F are configured so that the boundary between the upper midsole 4 and the long lower midsole 5E, 5F on the sole support surface (upper surface) is located in front of position P90.

[0078] As described above, soles 1D to 1F are configured in the same manner as soles 1A to 1C, except that lower midsoles 5D to 5E are configured to be longer lower midsoles than lower midsoles 5A to 5C of soles 1A to 1C. Therefore, a detailed description of other configurations will be omitted.

[0079] As described above, according to the second embodiment, at least one of the lower midsoles 5A-5F (three lower midsoles 5D-5F in the second embodiment) of the multiple types (six types) of soles 1A-1F is configured as a long lower midsole whose front end is located further forward than the front end of the upper midsole 4. With this configuration, while using the same shape of upper midsole 4, the lower midsoles 5A-5F are configured with lower midsoles 5A-5C whose front end is not located further forward than the front end of the upper midsole 4 and the long lower midsoles (lower midsoles 5D-5F), thereby making it possible to provide soles of different sizes (soles 1A-1C and soles 1D-1F). In other words, in the second embodiment, by using the same shape of upper midsole 4 and changing the type of lower midsole 5A-5F, it is possible to provide soles 1A-1F that differ not only in the inclination angle α of the sole support surface (the angle α between the line T and the ground) but also in size. Therefore, according to embodiment 2, the initial investment costs can be further reduced when manufacturing a sole series S consisting of multiple types of soles 1A to 1F that can encourage the wearer to run using a forefoot running style or a midfoot running style.

[0080] In addition, in the second embodiment, the lower midsoles 5D-5F (long lower midsoles) are configured so that the boundary between the upper midsole 4 and the lower midsoles 5D-5F (long lower midsoles) is located forward of position P90 on the sole support surface (upper surface) of the soles 1D-1F. Normally, the wearer's foot rests on the area rearward of position P90 on the sole support surface of the sole, and the wearer's foot does not rest on the area on the sole support surface from position P90 to the tip position P100. Therefore, by configuring the soles as described above, the wearer's foot does not rest on the boundary between the upper midsole 4 and the lower midsoles 5D-5F (long lower midsoles) when wearing the shoes, and therefore does not feel any discomfort.

[0081] Other Embodiments In the above embodiments 1 and 2, the soles (soles 1A to 1C or soles 1A to 1F) constituting the sole series S each had a plate 6, but the soles (soles 1A to 1C or soles 1A to 1F) constituting the sole series S may not have a plate 6.

[0082] In addition, in the first and second embodiments, the plates 6 of the soles (soles 1A to 1C or soles 1A to 1F) constituting the sole series S all have the same shape, but the shapes of the plates 6 may be varied.

[0083] In addition, in the above-mentioned first embodiment, the sole series S is composed of three types of soles 1A to 1C each having a different inclination angle α of the sole support surface, and in the above-mentioned second embodiment, the sole series S is composed of a total of six types of soles 1A to 1F with three types (three kinds) of inclination angle α of the sole support surface and two sizes (two kinds), but the number of types of soles constituting the sole series S is not limited to the above. The sole series S may be composed of soles with four or more types (four kinds) of inclination angle α of the sole support surface and / or three or more sizes (three kinds). [Industrial Applicability]

[0084] As described above, the present invention is useful for a sole series and a method for manufacturing a sole. [Explanation of symbols]

[0085] S Sole Series 1A~1F Sole 2A~2F Midsole 3A~3F Outsole 4 Upper midsole 5A~5F Lower midsole 6 plates

Claims

1. A sole series consisting of multiple types of soles each having a midsole extending from a heel portion to a toe portion and having an upper surface that serves as a sole support surface that supports the sole of a shoe wearer, Each of the midsoles of the plurality of types of soles is an upper midsole made of an elastic material extending from the heel portion to the toe portion; a lower midsole having an upper surface that conforms to the lower surface of the upper midsole and that is made of an elastic material and extends from the heel portion to the toe portion; In each of the above soles, The position of the rearmost end on the sole support surface is P0, The position of the most distal end on the sole support surface is P100, The line connecting the position P0 and the position P100 is Ls. A curve connecting the position P0 and the position P100 along the sole support surface is Lc. The length of the curve Lc is L, P15 is the position on the curve Lc that is 0.15L away from the position P0. P45 is the position on the curve Lc that is 0.45L away from the position P0. P68 is the position on the curve Lc that is 0.68L away from the position P0. The intersection of the lower surface and a line perpendicular to the line Ls passing through the position P45 is C, A straight line connecting the position P15 and the position P68 is designated by T. The intersection of the line perpendicular to the line Ls passing through the position P45 and the lower surface of the upper midsole is P45'. The intersection of the line perpendicular to the line Ls passing through the position P68 and the lower surface of the upper midsole is P68'. When the line connecting the position P45' and the position P68' is T', The plurality of types of soles are configured so that, when not worn, they contact the ground at the intersection C, while their heel portions do not contact the ground, The upper midsoles of the plurality of types of soles are formed to have the same shape, The lower midsoles of the plurality of types of soles are formed in different shapes so that the angle formed by the straight line T and the ground varies from one sole to another, and the angle formed by the straight line T' and the ground varies from one sole to another. A sole series characterized by its

2. In the sole series according to claim 1, At least one of the lower midsoles of the plurality of types of soles has a front end located forward of a front end of the upper midsole, and an upper surface of the front end located forward of the front end of the upper midsole constitutes a front end of the sole support surface. A sole series characterized by its

3. In the sole series according to claim 2, The above long lower midsole is When a position on the curve Lc that is 0.90L away from the position P0 is P90, The position P90 is configured to be on the upper surface of the upper midsole. A sole series characterized by its

4. In the sole series according to claim 1, each of the plurality of types of soles includes a plate made of an elastic material having a higher hardness than the upper midsole and provided between the upper midsole and the lower midsole; The plates of the plurality of types of soles are formed in the same shape. A sole series characterized by its

5. A method for manufacturing a sole having a midsole that extends from a heel portion to a toe portion and has an upper surface that serves as a sole support surface that supports the sole of a shoe wearer, The sole is one of the soles constituting the sole series described in claim 1, A selection step is provided for selecting one of the lower midsoles from a plurality of types of lower midsoles having different shapes. A method for manufacturing a sole comprising the steps of:

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