Shoe with reinforcement device for reinforcing an upper

A reinforcement device reinforcing an upper includes: a rear first portion placed between a sole and a top line in a rear end portion of the upper; a rear second portion placed in a boundary portion between the upper and the sole in the rear end portion of the upper; a lateral first portion being continuous with the rear first portion and extending toward the sole on the lateral side; a medial first portion being continuous with the rear first portion and extending toward the sole on the medial side, the medial first portion being less flexurally deformable than the lateral first portion; and a medial second portion being continuous with the rear second portion and extending toward an anterior direction from the rear second portion along the medial side boundary portion so that the medial side boundary portion is less flexurally deformable than the lateral side boundary portion.

TECHNICAL FIELD

The present invention relates to a shoe including a reinforcement device reinforcing a heel portion of an upper.

BACKGROUND ART

A heel counter, which is an example of a reinforcement device, covers the opposite side surfaces and the rear surface of the heel and maintains the shape of the heel portion of the upper. When the entire heel is wrapped around by the heel counter formed from a resin part, the heel portion of the upper has a high rigidity, but it inhibits the deformation of the upper in conformity with the shape of the heel of the wearer. That is, the fitting property of the heel portion deteriorates.

For example, heel counters formed in lattice shapes are known in the art, as described in the patent documents identified below. Moreover, heel counters having different shapes on the lateral side and on the medial side are known in the art.

CITATION LIST

Patent Literature

SUMMARY OF INVENTION

It is an object of the present invention to provide a reinforcement device of an upper of a shoe that improves the stability property and the following property (the conforming property) of the shoe from landing to takeoff while running.

A shoe in one aspect of the present invention includes: an upper1, a reinforcement device4reinforcing the upper1, and a sole2attached to the upper1, wherein:

the upper1includes a lateral side boundary portion120between the upper and the sole2on a lateral side12of the upper, a medial side boundary portion110between the upper and the sole2on a medial side11of the upper, and a rear boundary portion10between the upper and the sole2in a rear end portion15of the upper;

the medial side boundary portion110and the lateral side boundary portion120are continuous with each other via the rear boundary portion10; and

the reinforcement device4includes:

a rear first portion B1placed between the sole2and a top line (a collar or a wearing opening)20of the upper1in a rear end portion15of the upper;

a rear second portion B2placed in the rear boundary portion10;

a lateral first portion L1being continuous with the rear first portion B1and extending toward the sole2on the lateral side12of the upper;

a medial first portion M1being continuous with the rear first portion B1and extending toward the sole2on the medial side11of the upper, the medial first portion M1being less flexurally deformable than the lateral first portion L1; and

a medial second portion M2being continuous with the rear second portion B2and extending toward an anterior direction from the rear second portion B2along the medial side boundary portion110on the medial side11of the upper so that the medial side boundary portion110is less flexurally deformable than the lateral side boundary portion120.

With ordinary athletic shoes, a resin-made or resin-impregnated member, called a heel counter, is arranged on the medial and lateral sides of the heel portion. A heel counter maintains the shape of the shoe, and suppresses the pronation of the subtalar joint that occurs during the support period after landing. The flexural rigidity of the medial side of the heel counter substantially contributes to the suppression of the pronation, and it serves to support, by means of the medial side of the upper, the foot being urged to collapse toward the medial side. The medial first portion M1and the medial side boundary portion110, which are less flexurally deformable than the lateral first portion L1, will serve to suppress the pronation and improve the stability property.

The foot, which lands starting from the lateral side of the heel portion, exhibits pronation thereafter. The lateral side boundary portion120is more flexurally deformable and more compressively deformable than the medial side boundary portion110, thereby increasing the amount of deformation of the lateral side boundary portion120upon heel contact. As a result, it is expected to suppress the speed at which the foot collapses toward the medial side and decrease the pronation to be exhibited thereafter.

In the latter half of the support period, the heel rises entailing the weight transfer, the forefoot portion of the sole dorsiflexes, and a restoring force occurs in the sole in such a direction that urges the rearfoot portion of the sole away from the foot. At this point, the upper is required to have a good foot fitting property, and particularly, the heel portion of the sole and that of the upper are required to have a good foot following property during the latter half of the support period. At this point, the force that acts upon the upper from the foot is a force that pushes the back side (the rear end portion) of the heel portion of the upper in the direction normal to the upper surface. Therefore, there is a demand for the back side of the heel portion of the shoe to have a structure that suppresses the deformation against such a force.

In view of this demand, in the present invention, the rear first portion and the rear second portion placed on the rear end portion of the upper increase the rigidity of the back side of the heel portion, thereby suppressing the deformation of the heel portion. This will improve the following property.

The lateral first portion L1, which is more flexurally deformable than the medial first portion M1, extends from the rear first portion B1toward the sole2. Therefore, the lateral first portion L1suppresses the stretch of the heel portion lateral side in the direction that connects between the lower portion of the upper below the ankle and the rear first portion B1without excessively increasing the flexural rigidity of the heel portion lateral side. This suppresses the deformation due to a force that pushes the back side (the rear end portion) of the heel portion of the upper in the direction normal to the upper surface. This as a result will improve the following property.

As described above, the present invention is expected to improve the stability property and the foot following property during the support period.

The rear first portion and the rear second portion increase the rigidity of the back side of the upper. In view of this, “the rear end portion of the upper”, where the rear first portion and the rear second portion are placed, means an extent of 20% or less extending from the rear end of the upper with respect to the entire length (the length of the shoe in the longitudinal direction) 100% of the upper on the sagittal plane. This is because when the reinforcement device is placed in such an extent, it is possible to increase the rigidity of the back side of the upper. Therefore, it is preferred that at least a portion of the rear first portion and the rear second portion is placed in the rear end portion, which is the 20% extending from the rear end of the upper. It is preferred that at least a portion of the rear first portion is placed in an extent of 10% or less from the rear end of the upper and at least a portion of the rear second portion is placed in an extent of 20% or less. It is more preferred that at least a portion of the rear first portion is placed in an extent of 10% or less from the rear end of the upper and at least a portion of the rear second portion is placed in an extent of 15% or less. It is particularly preferred that at least a portion of the rear first portion and at least a portion of the rear second portion are both placed in an extent of 10% or less from the rear end of the upper.

The medial side refers to the side that is closer to the median on the frontal plane of the body, and is commonly referred to often as the inner side or the inner side of the foot. The lateral side refers to the side that is farther away from the median on the frontal plane of the body, and is commonly referred to often as the outer side or the outer side of the foot.

Being less flexural deformable includes cases where the flexural rigidity ∫EIz is higher, and also cases where the reinforcement device is formed in a loop shape and has less deformation due to bending moment.

The flexural rigidity means the integral value ∫EIz of the Young's modulus (longitudinal elastic modulus) E and the moment of inertia of area Iz of the member.

Each first portion and the corresponding second portion may be vertically continuous with each other or vertically separated from each other. The medial first portion and the medial second portion may have a window (through hole) therebetween, or may be continuous with each other in a flat plate shape. A lateral second portion having a thin plate shape may be provided also on the lateral side.

DESCRIPTION OF EMBODIMENTS

Preferably, the lateral first portion L1extends toward the sole2and toward the anterior direction reaching the sole2, the lateral first portion L1(the reinforcement device4) further including a lateral tucked end portion LE tucked between the sole2and the upper1.

The lateral tucked end portion of the lateral first portion is tucked between the sole and the upper, and the lateral first portion increases the tensile rigidity between the lower end of the upper and the rear end portion of the upper below the lateral malleolus of the heel portion. This will improve the following property.

Preferably, the reinforcement device4includes a heel counter4made of a thermoplastic resin; and

the heel counter4includes the rear first portion B1, the rear second portion B2, the medial first portion M1and the medial second portion M2, which are integrally continuous with each other.

In this case, it is easy to manufacture the reinforcement device.

Preferably, the heel counter4further integrally (and seamlessly) includes the lateral first portion L1.

In this case, it is even easier to manufacture the reinforcement device.

Preferably, a moment of inertia of area of the medial first portion M1is greater than a moment of inertia of area of the lateral first portion L1.

The moment of inertia of area Iz of the lateral first portion L1is smaller than the moment of inertia of area Iz of the medial first portion M1. Therefore, it is easy to lower the flexural rigidity of the upper on the lateral side of the heel portion. As a result, the pronation will be decreased as described above.

Preferably, the lateral first portion L1is formed from a tape material separate from the heel counter4.

The tape material has a lower flexural rigidity than the heel counter, and gives a high tensile rigidity. Therefore, the upper on the lateral side of the heel portion has a low flexural rigidity, thereby decreasing the pronation. Since the tensile rigidity is high, a high following property will be exhibited.

Preferably, the heel counter4is absent (not provided) in the lateral side boundary portion120of the upper1.

In this case, the flexural rigidity on the lateral side of the heel portion is low.

A shoe in another aspect of the present invention includes: an upper1, a reinforcement device4reinforcing the upper1, and a sole2attached to the upper1, wherein:

the upper1includes a lateral side boundary portion120between the upper and the sole2on a lateral side12of the upper, a medial side boundary portion110between the upper and the sole2on a medial side11of the upper, and a rear boundary portion10between the upper and the sole2in a rear end portion15of the upper;

the medial side boundary portion110and the lateral side boundary portion120are continuous with each other via the rear boundary portion10; and

the reinforcement device4includes:

a rear first portion B1placed between the sole2and a top line (a collar)20of the upper1in a rear end portion15of the upper;

a rear second portion B2placed in the rear boundary portion10;

a lateral first portion L1being continuous with the rear first portion B1and extending toward the sole2on the lateral side12of the upper;

a medial first portion M1being continuous with the rear first portion B1and extending toward the sole2on the medial side11of the upper; and

a medial second portion M2being continuous with the rear second portion B2and extending toward an anterior direction from the rear second portion B2along the medial side boundary portion110on the medial side11of the upper, wherein:

the lateral first portion L1extends toward the sole2and toward the anterior direction reaching the sole2, the lateral first portion L1including a lateral tucked end portion LE tucked between the sole2and the upper1;

the rear second portion B2extends to the sole2, the rear second portion B2including a rear tucked end portion BE tucked between the sole2and the upper1; and

the medial second portion M2includes a medial tucked end portion ME that is tucked between the sole2and the upper1and connects together the rear second portion B2and a lower end portion of the medial first portion M1.

In this aspect, the medial second portion M2extending along the medial side boundary portion110includes the medial tucked end portion ME that connects between the rear second portion B2and the lower end portion of the medial first portion M1, and is therefore less flexural deformable as compared with the lateral side.

The reinforcement device4having such a structure maintains the shape of the shoe, and suppresses the pronation of the subtalar joint that occurs during the support period after landing. Therefore, it serves to support, by means of the medial side of the upper, the foot being urged to collapse toward the medial side.

The foot, which lands starting from the lateral side of the heel portion, exhibits pronation thereafter. The upper on the lateral side having the lateral tucked end portion LE is more flexurally deformable as compared with the upper on the medial side having the medial tucked end portion ME that connects together the rear second portion B2and the lower end portion of the medial first portion M1.

That is, the lateral side boundary portion120is more flexurally deformable than the medial side boundary portion110, thereby increasing the amount of deformation of the lateral side boundary portion120upon heel contact. As a result, it is expected to suppress the speed at which the foot collapses toward the medial side and decrease the pronation to be exhibited thereafter.

As described above, in the latter half of the support period, the rear first portion B1and the rear second portion B2placed in the rear end portion of the upper increase the rigidity on the back side of the heel portion, thereby suppressing the deformation of the heel portion. This will improve the following property.

The lateral first portion L1is more flexurally deformable as compared with the medial side having the medial tucked end portion ME. The lateral first portion L1suppresses the stretch of the heel portion lateral side in the direction that connects between the lower portion of the upper and the rear first portion B1below the ankle without excessively increasing the flexural rigidity of the heel portion lateral side. This suppresses the deformation due to a force that pushes the back side (the rear end portion) of the heel portion of the upper in the direction normal to the upper surface. This as a result will improve the following property.

As described above, the present invention is expected to improve the stability property and the foot following property during the support period.

Preferably, the reinforcement device4includes a heel counter4made of a thermoplastic resin;

the heel counter4is attached to an outer surface of the upper1; and

the heel counter4includes a rear first portion B1, a rear second portion B2, a lateral first portion L1, a medial first portion M1and a medial second portion M2, which are integrally and seamlessly continuous with each other.

In this case, it is easy to manufacture the reinforcement device4.

Preferably, a rear end of the lateral tucked end portion LE and a front end of the rear tucked end portion BE are unconnected and separated from each other in an anterior-posterior direction.

In this case, the upper on the lateral side has a lower flexural rigidity as compared with the upper on the medial side having the medial tucked end portion ME. As a result, the pronation will be decreased as described above.

Preferably, the heel counter4includes a lateral bridge42that extends toward a diagonal anterior-upward direction from the rear second portion B2to the lateral first portion L1; and

a low-rigidity portion is provided between the lateral bridge42and the sole2, the low-rigidity portion having a rigidity lower than that of the lateral bridge42.

With the structure that includes a low-rigidity portion between the lateral bridge42and the sole2, it is easy to lower the flexural rigidity of the lateral side boundary portion120. Therefore, with such a structure, it is easy to decrease the pronation.

Preferably, the heel counter4includes a lateral bridge42that extends toward a diagonal anterior-upward direction from the rear second portion B2to the lateral first portion L1; and an exposed portion121is provided between the lateral bridge42and the sole2, and the lateral side boundary portion120of the upper1is exposed through the exposed portion121.

With the structure in which the lateral side boundary portion120includes the exposed portion121, it is easy to lower the flexural rigidity of the lateral side boundary portion120. Therefore, with such a structure, it is easy to decrease the pronation.

Preferably, the lateral first portion L1, the lateral bridge42, the rear second portion B2and the sole2define a closed lower area α1; and the exposed portion121is placed in the lower area α1.

With the structure including the lateral side boundary portion120where the lower area α1includes the exposed portion121, it is easy to lower the flexural rigidity of the lower area α1. Therefore, with such a structure, it is easy to decrease the pronation.

Preferably, the lower area α1and the exposed portion121are shaped so as to protrude upward.

With the structure in which the lower area α1and the exposed portion121are shaped so as to protrude upward, it is easy to increase the size of the exposed portion121. Particularly, it is easy to increase the size of the exposed portion121near the lateral side boundary portion120. Therefore, with such a structure, it is easy to lower the flexural rigidity of the lateral side boundary portion120and decrease the pronation.

Preferably, the lateral first portion L1, the lateral bridge42, the rear first portion B1and the rear second portion B2define a closed window area α2; and

in the window area α2, the heel counter4defines a rear through hole Bh running through the heel counter4.

With the heel counter4that defines the rear through hole Bh in the window area α2on the lateral side, it is easy to lower the flexural rigidity of the upper on the lateral side of the heel portion. Therefore, the pronation will be decreased.

Preferably, the reinforcement device4includes a heel counter4made of a thermoplastic resin;

the upper1includes an inner skin (14) placed on a side that comes into contact with a foot, and an outer skin (13) on an opposite side of the inner skin14;

the heel counter4is a built-in counter4that is built in between the inner skin and the outer skin; and

the built-in counter4includes the rear first portion B1, the rear second portion B2, the lateral first portion L1, the medial first portion M1and the medial second portion M2, which are integrally and seamlessly continuous with each other.

The built-in heel counter is sandwiched between the inner skin and the outer skin of the upper and functions as the core of the upper, and the built-in heel counter will easily serve as a heel counter despite being thin.

Preferably, the built-in counter4is plate-shaped as a whole and further includes a low-rigidity portion LW whose rigidity is lower than that of the medial first portion M1and the medial second portion M2, wherein the low-rigidity portion LW is surrounded by (is bordered on) the rear first portion B1, the rear second portion B2and the lateral first portion L1.

In this case, the low-rigidity portion LW on the lateral side, which is a surrounded area, lowers the flexural rigidity of the upper on the lateral side of the heel portion. Therefore, the pronation will be decreased as described above.

Preferably, the built-in counter4is plate-shaped as a whole and further includes a lateral second portion L2, the lateral second portion L2being continuous with the rear second portion B2, and extending on the lateral side12of the upper along the lateral side boundary portion120from the rear second portion B2toward the anterior direction;

the built-in counter4includes a lateral central portion LC surrounded by the rear first portion B1, the rear second portion B2, the lateral first portion L1and the lateral second portion L2; and

the lateral central portion LC defines a thin portion having a smaller thickness than surrounding portions, one or more slits, or one or more through holes.

In this case, the lateral central portion LC forms the low-rigidity portion LW, lowering the flexural rigidity of the upper on the lateral side of the heel portion. Therefore, the pronation will be decreased as described above.

Preferably, the built-in counter4is plate-shaped as a whole and further includes a lateral second portion L2, the lateral second portion L2being continuous with the rear second portion B2, and extending on the lateral side12of the upper along the lateral side boundary portion120from the rear second portion B2toward the anterior direction;

the built-in counter4includes a lateral central portion LC surrounded by the rear first portion B1, the rear second portion B2, the lateral first portion L1and the lateral second portion L2;

the built-in counter4includes a medial central portion MC surrounded by the rear first portion B1, the rear second portion B2, the medial first portion M1and the medial second portion M2; and

a thickness of the lateral central portion LC is smaller than a thickness of the medial central portion MC.

With the structure in which the thickness of the lateral central portion LC is smaller than the thickness of the medial central portion MC as described above, the flexural rigidity of the lateral central portion LC is lower than the flexural rigidity of the medial central portion MC. Therefore, such a structure will lower the flexural rigidity of the upper on the lateral side of the heel portion and decrease the pronation as described above.

Preferably, the built-in counter4is plate-shaped as a whole and includes a medial portion4M placed on a medial side and a lateral portion4L placed on a lateral side, which are seamlessly continuous with each other; and

an average thickness of the lateral portion4L is smaller than an average thickness of the medial portion4M.

With the thin structure, the flexural rigidity of the lateral portion4L is lower than the flexural rigidity of the medial portion4M. Therefore, such a structure will lower the flexural rigidity of the upper on the lateral side of the heel portion and decrease the pronation as described above.

Preferably, the lateral central portion LC includes a plurality of through holes arranged in a scattered pattern.

The lateral central portion LC having a plurality of through holes forms the low-rigidity portion LW, lowering the flexural rigidity of the upper on the lateral side of the heel portion. Therefore, the pronation will be decreased as described above.

Preferably, the lateral central portion LC defines a plurality of slits extending in an anterior-posterior direction.

The lateral central portion LC defining a plurality of slits forms the low-rigidity portion LW, lowering the flexural rigidity of the upper on the lateral side of the heel portion. Therefore, the pronation will be decreased as described above.

Preferably, the built-in counter4is plate-shaped as a whole with a lower edge; and

the lower edge is formed in an upward arch shape between the lateral tucked end portion LE and the rear tucked end portion BE.

With the structure in which the lower edge of the built-in counter is formed in an upward arch shape on the lateral side, the lateral side boundary portion120is more flexurally deformable than the medial side boundary portion110. Therefore, the pronation will be decreased as described above.

Preferably, the shoe further includes an external counter attached to an outer surface of a rearfoot portion of the upper1.

When an additional external counter is provided in addition to the built-in counter4having the function as described above, it is possible to realize the function-oriented structure of the built-in counter4and the design-oriented structure of the external counter. Therefore, it will be advantageous in two ways, i.e., for the function and for the design.

Any feature illustrated and/or depicted in conjunction with one of the aforementioned aspects or the following embodiments may be used in the same or similar form in one or more of the other aspects or other embodiments, and/or may be used in combination with, or in place of, any feature of the other aspects or embodiments.

EMBODIMENTS

The present invention will be understood more clearly from the following description of preferred embodiments taken in conjunction with the accompanying drawings. Note however that the embodiments and the drawings are merely illustrative and should not be taken to define the scope of the present invention. The scope of the present invention shall be defined only by the appended claims. In the accompanying drawings, like reference numerals denote like components throughout the plurality of figures.

As shown inFIG. 1toFIG. 3, the present athletic shoe includes an upper1, a midsole2, an outsole3and a heel counter (reinforcement device)4.

As shown inFIG. 4, the upper1includes a cushioning material18made of a foamed resin between a quarter13and a quarter lining14. Note that the quarter13and the quarter lining14may be formed from a plurality of layers of fabric.

An insole6is sewn onto the upper1. On the other hand, the upper1ofFIG. 1includes a top line20through which the leg extends upward and through which the foot is inserted.

The upper1includes a fastening means such as a shoelace (not shown). The shoelace fastens the upper1so that a medial side11of the upper1and a lateral side12ofFIG. 2are brought into close contact with the foot in the vicinity of the top line20. The reference numeral16denotes a tongue provided in front of the top line20.

The medial side11of the upper1covers the medial surface of the foot. The lateral side12of the upper1covers the lateral surface of the foot. A rear end portion15of the upper1covers the back surface of the foot. The medial side11, the lateral side12and the rear end portion15of the upper1together form the top line20.

In the vicinity of the top line20of the upper1, the medial side11of the upper1ofFIG. 1covers the front end portion B8fof the talus bone B8and the front end portion J8fof the subtalar joint J8. On the other hand, the lateral side12of the upper1ofFIG. 2covers the front end portion B8fof the talus bone B8and the front end portion J8fof the subtalar joint J8. In the present embodiment, a part of the lateral malleolus Ml and the medial malleolus Mm ofFIG. 1may each be exposed above the top line20.

As shown inFIG. 4A, the heel counter4is bonded and secured with no gap to the outer surface of the upper1on the medial side11and the lateral side12of the upper1. The upper1with the heel counter4bonded to the outer surface thereof as described above has a high flexural rigidity and serves to suppress the pronation.

The midsole2and the outsole3ofFIG. 1are stacked together below the heel counter4and the insole6.

Next, the heel counter4, which is a reinforcement device, will be described. InFIG. 1toFIG. 5, the heel counter4is dotted.

The heel counter4shown inFIGS. 1 to 3is bonded to, and partially exposed on, the outer surface of the fabric of the upper1to maintain the shape of a heel portion17of the soft upper1, which includes a plurality of layers of fabric and is soft. The counter4includes the medial portion4M placed on the medial side and the lateral portion4L placed on the lateral side, which are integrally and seamlessly continuous with each other.

The heel counter4is formed integrally from a material that includes a thermoplastic resin component.

As shown inFIG. 1toFIG. 3, the medial portion and the lateral portion of the heel counter4are formed asymmetric with each other. The heel counter4forms a part or whole of the reinforcement device. The heel counter4includes a lateral tucked end portion LE, a rear tucked end portion BE and a medial tucked end portion ME to be described later.

The heel counter4ofFIG. 3is made of a thermoplastic resin, and includes a rear first portion B1, a rear second portion B2, a lateral first portion L1, a medial first portion M1and a medial second portion M2, which are formed integrally continuous with each other. The heel counter4integrally includes three bridges40to42, for example.

As clearly shown inFIG. 1andFIG. 3, in the rear end portion15of the upper, the rear first portion B1is placed between the midsole2and the top line20of the upper1. The second portion B2is placed along the boundary portion10between the rear end portion15of the upper1and the midsole2. Moreover, the rear second portion B2extends to the midsole2, and includes the rear tucked end portion BE that is tucked between the midsole2and the upper1. The bridge40on the rear center portion ofFIG. 3vertically connects between the center of the rear first portion B1and the center of the rear second portion B2. That is, the bridge40is placed directly behind the calcaneal bone B9ofFIG. 1.

As shown inFIG. 1andFIG. 2, the rear end portion15of the upper1is an extent of 20%, preferably 10%, extending from a rear end1E of the upper with respect to the entire length 100% of the upper on the sagittal plane. In the rear end portion15, the rear first portion B1and the rear second portion B2ofFIG. 3extend in the lateral direction while being curved along the upper.

In the rear end portion15on the medial side ofFIG. 1, the medial bridge41diagonally connects between the rear first portion B1and the rear second portion B2. On the other hand, in the rear end portion15on the lateral side ofFIG. 2, the lateral bridge42diagonally connects between the rear first portion B1and the rear second portion B2. A rear through hole Bh, which appears to be a window, may be provided between the three bridges40to42, as shown inFIG. 3.

The lateral first portion L1, the lateral bridge42, the rear first portion B1and the rear second portion B2define a closed window area α2, and the heel counter4defines the rear through hole Bh running through the heel counter4in the window area α2.

On the lateral side12ofFIG. 2, the lateral first portion L1extends toward the midsole2below and toward the diagonal anterior direction reaching the midsole2. The heel counter4includes the lateral tucked end portion LE that is tucked between the midsole2and the upper1.

The lateral tucked end portion LE is formed by the lateral first portion L1extending toward the midsole2and toward the anterior direction X1reaching the midsole2so as to be tucked between the midsole2and the upper1.

On the lateral side12, the heel counter4is not placed in the lateral side boundary portion120of the upper1. In the case of the present embodiment, the lateral side boundary portion120includes an exposed portion121that is exposed and not covered by the heel counter4.

The lateral first portion L1, the lateral bridge42, the rear second portion B2and the midsole2define a closed lower area α1, and the exposed portion121is placed in the lower area α1.

Note that the lateral side boundary portion120means the vicinity of the boundary between the lateral side12of the upper1and the midsole2.

On the medial side11ofFIG. 1, the medial first portion M1extends toward the midsole2below and toward the diagonal anterior direction reaching the midsole2, and is continuous with the medial second portion M2. On the medial side11of the upper, the medial second portion M2extends toward the anterior direction from the rear second portion B2along the medial side boundary portion110to be continuous with the medial first portion M1.

A medial through hole Mh, which appears to be a window, may be provided between the medial first portion M1and the medial second portion M2which are arranged in the vertical direction.

Note that the medial side boundary portion110means the vicinity of the boundary between the medial side11of the upper1and the midsole2.

As shown in the cross sections ofFIG. 4andFIG. 5, the medial tucked end portion ME, which generally is a lower half of the medial second portion M2, is tucked between the midsole2and the upper1. The tucked end portion ME is the medial second portion M2tucked between the sole2and the upper1, and connects together the rear second portion B2and the lower end portion of the medial first portion M1. On the other hand, an exposed portion M21, which generally is an upper half of the medial second portion M2ofFIG. 1, covers the medial side boundary portion110of the upper1and is exposed.

Regarding the flexural deformation that occurs when the upper collapses in the arrow directions ofFIG. 4andFIG. 5, the value of the flexural rigidity ∫EIz of the medial first portion M1is greater than the value of the flexural rigidity ∫EIz of the lateral first portion L1. In the case of the present embodiment, regarding the flexural deformation, the value of the moment of inertia of area Iz of the medial first portion M1is greater than the value of the moment of inertia of area Iz of the lateral first portion L1. For example, the thickness of the medial first portion M1ofFIG. 5is greater than the thickness of the lateral first portion L1.

With such flexural deformation, the moment of inertia of area Iz has such a correlation that it is in proportion to the cube of the thickness.

In the case of the present embodiment, the medial first portion M1and the lateral first portion L1ofFIG. 3are formed from the same material. Therefore, the medial first portion M1and the lateral first portion L1have an equal Young's modulus (longitudinal elastic modulus) E.

The medial second portion M2is placed on the medial side boundary portion110ofFIG. 1, whereas a member that corresponds to the medial second portion M2(FIG. 1) is not placed on the lateral side boundary portion120ofFIG. 2. That is, the medial second portion M2is placed on the medial side boundary portion110of FIG.1so that the medial side boundary portion110ofFIG. 1is less flexural deformable than the lateral side boundary portion120ofFIG. 2.

On the medial side11ofFIG. 1, the medial first portion M1, the medial second portion M2and the bridge41are formed to be continuous with each other in a loop shape. The loop-shaped portion increases the average flexural rigidity of the lower portion of the upper from the rear end of the talus bone B8to the front end of the lateral malleolus Ml (FIG. 2). The loop-shaped heel counter4ofFIG. 1makes the medial first portion M1less flexurally deformable than the lateral first portion L1ofFIG. 2.

Next, a test that was conducted to verify the validity of the present invention will be described. For this purpose, first, samples of Types1to5shown inFIG. 6were prepared.

The shoe of Type1ofFIG. 6includes a heel counter that has generally the same shape on the medial side and on the lateral side. The lateral side and the medial side of Type1have a similar structure to that of the medial side of the heel counter of Embodiment 1. That is, the rigidity of the heel portion of the upper of Type1is generally the same on the medial side and on the lateral side.

The shoes of Types2to5were made by partially cutting off the lateral portion and the back portion of the heel counter of Type1. Note that the medial portions of the shoes of Types2to5are similar to those of the heel counter of Type1.

The heel counter of Type2is obtained by being cut off at the lateral side boundary portion120(FIG. 2) between the upper of the heel portion lateral side and the midsole2.

The heel counter of Type3is obtained by partially cutting off the lateral side while leaving at the lateral side boundary portion120(FIG. 2), the rear first portion and the rear second portion.

The heel counter of Type4is obtained by cutting off most of the lateral side while leaving the rear first portion and the rear second portion.

The heel counter of Type5is obtained by cutting off most of the rear first portion and the entire lateral side.

The pronation (the heel portion eversion angle ß and the lower leg internal rotation angle γ) and the heel portion holding property (the evaluation value Disp.Z of the foot following property during the latter half of the support period) were measured while actually running. The results are shown inFIG. 7toFIG. 9.

The evaluation value Disp.Z of the following property is the vertical displacement of the foot with respect to the shoe. Therefore, the maximum value of Disp.Z, which is observed during heel rise, is measured as the evaluation value Disp.Zmax, wherein the value being smaller means a better following property and a higher heel portion holding property.

It was confirmed that for the heel portion eversion angle ß ofFIG. 7, Type2and Type5have smaller absolute values than Type1, and for the lower leg internal rotation angle γ ofFIG. 8, Type2, Type4and Type5have smaller absolute values than Type1, i.e., an improvement in the stability property.

With the shoe of Type1ofFIG. 6, the heel counter is present in the lateral side boundary portion120(FIG. 2) of the heel portion lateral side, where the sole first comes into contact with the ground.

In contrast, the samples of Types2,4and5with an improved stability property described above are obtained by the heel counter being cut off at the lateral side boundary portion120(FIG. 2). The low rigidity of the lateral side boundary portion120(FIG. 2) increases the deformation of the sole upon landing. It is believed that this suppresses the speed at which the foot collapses toward the medial side and decreases the pronation to be exhibited thereafter. That is, it is believed that the absolute value of the heel portion eversion angle ß ofFIG. 7and the absolute value of the lower leg internal rotation angle γ ofFIG. 8are small, thereby improving the stability property.

As described above, it can be seen that in order to improve the stability property, it is important to lower the rigidity of the lateral side boundary portion120ofFIG. 2.

For the following property ofFIG. 9, i.e., the heel portion holding property, it can be seen that the evaluation value Disp.Zmax of the following property for Type3, Type4and Type5is increased as compared with Type1, thereby resulting in a poor heel portion holding property.

With the shoes of Type3, Type4and Type5ofFIG. 6, most of the heel counter is cut off on the lateral side, thereby lowering the tensile rigidity of the heel portion lateral side. During the dorsiflex phase of the upper, a force that pushes the heel portion of the upper acts in the direction normal to the upper surface, thereby causing a stretch deformation in the area of the heel portion lateral side. It is believed that with the shoes of Type3, Type4and Type5, the heel portion holding property is lowered because the cut-off allows the deformation.

Moreover, with the shoe of Type5, the counter is cut off not only on the lateral side but also on the back side, thereby lowering the flexural rigidity of an area upon which a force acts directly. It is believed that the heel portion deformation is thus greater as compared with Type3and Type4, resulting in the lowest heel portion holding property among all the samples.

As described above, it can be seen that in order to improve the heel portion holding property, it is important to increase the tensile rigidity of an area that connects together the lateral side and the back portion of the heel portion and the rigidity of the back portion of the heel portion.

Next, another test that was conducted to verify the validity of the present invention will be described. For this purpose, samples of Types21to27shown inFIG. 14were prepared. These samples have similar medial sides to those of the samples ofFIG. 6.FIG. 14shows the lateral side of the heel counter.

The heel counters of Type21ofFIG. 14(a)and Type22of FIG.14(b) are provided with a lateral through hole Lh that is larger than the medial through hole Mh (FIG. 1).

With the sample of Type21ofFIG. 14(a), the lower end of the lateral through hole Lh is set to be generally at the midsole upper edge2e.

With the sample of Type22ofFIG. 14(b), the lower end of the lateral through hole Lh is set to be below the midsole upper edge2e.

The heel counters of Types23and24ofFIGS. 14(c) and 14(d)have the lateral second portion L2that connect together the lateral tucked end portion LE and the rear tucked end portion BE.

With the heel counter of Type23, the lower end of the lateral second portion L2is set to be around the midsole upper edge2e.

With the heel counter of Type24, the lower edge of the lateral second portion L2is set to be above the midsole upper edge2e.

The heel counter of Type25ofFIG. 14(e)is obtained by cutting off about ⅓ of the central portion of the lateral second portion L2of the heel counter of Type21ofFIG. 14(a).

The heel counter of Type26ofFIG. 14(f)has a structure obtained by cutting off a rear upper portion on the lateral side of the heel counter of Type2ofFIG. 6.

The heel counter of Type27ofFIG. 14(g)has a structure obtained by partially cutting off a rear upper portion and a rear second portion on the lateral side of the heel counter of Type2ofFIG. 6.

The heel portion eversion angle ß was measured while actually running. The results are shown inFIG. 15andFIG. 16.

InFIG. 15, it can be understood that with Types21to26, excluding Type27, the heel portion eversion angle ß is smaller than Type1, as with Type2.

FIGS. 16(a) and 16(b)show the heel portion eversion angle ß for the various samples, wherein the horizontal axis of the graphs represents the cut-off percentage in the vertical direction and the foot longitudinal direction, respectively, of the lateral second portion L2(FIG. 14).

In the graph ofFIG. 16(a), it can be seen that the heel counters of Types23and24, where even though the lateral second portion L2(FIG. 14) is provided, the lateral second portion L2is not tucked by the midsole, have generally the same heel portion eversion angle ß as that of the heel counter of Type2. That is, also with Types23and24, the stability property will improve, as with Type2.

In the graph ofFIG. 16(b), it can be seen that from a comparison between Types25and26and Types1and2, as the cut-off percentage of the lateral second portion L2(FIG. 14) is greater, the absolute value of the heel portion eversion angle ß is smaller, thereby improving the stability property.

However, it can be seen that when a large portion of the rear tucked end portion BE (FIG. 14) is cut off, as with Type27ofFIG. 16(b), the absolute value of the heel portion eversion angle ß will be greater than Type21, lowering the stability property.

Next, other embodiments will be described.

InFIG. 10AandFIG. 10B, the quarter13of the upper includes a main member13aand a reinforcement member13b. The main member13ais placed over more than a half or most of the quarter13, covering the medial side and the lateral side of the foot. The reinforcement member13bis provided in the hatched area of the quarter13, for example, and may be stacked on the surface of the main member13aor may be provided by impregnating the main member13awith a resin.

The main member13amay be, for example, a mesh material having a lattice structure (mesh structure), a knit fabric, a woven fabric, or the like. These materials are more stretchable than the reinforcement member13b.

The reinforcement member13bof the medial side11ofFIG. 10Ais placed along the medial first portion M1of the heel counter4. On the other hand, the reinforcement member13bof the lateral side12ofFIG. 10Bforms a part of the reinforcement device, and forms the lateral first portion L1together with the heel counter4.

InFIG. 10B, the reinforcement member13bof the lateral side12is placed on the lateral side boundary portion120. The reinforcement member13bof the lateral side boundary portion120forms the lateral second portion L2. Therefore, the lateral side boundary portion120has a higher tensile rigidity than a portion where only the main member13ais placed, and has a lower flexural rigidity than the medial side boundary portion110ofFIG. 10A.

The heel counter4ofFIG. 10AandFIG. 10Bis not provided with a bridge on the rear center portion. The lateral first portion L1of the heel counter4extends toward the midsole2toward the anterior direction, but does not extend up to the midsole2.

The width WLof the lateral first portion L1of the heel counter4is greater than the width WMof the medial first portion M1. However, the lateral first portion L1of the heel counter4has a free end on the front side of the rear end portion15. Therefore, on the front side of the rear end portion15, the lateral first portion L1of the heel counter4is more flexurally deformable than the medial first portion M1ofFIG. 10A.

The bridges41and42of the medial side11and the lateral side12support the rear first portion B1, and therefore the compressive rigidity of the rear end portion15of the upper is high.

As in the present embodiment, the reinforcement member13bmay be provided only on the lateral side12.

In the present embodiment, the heel counter4is formed in a loop shape on the medial side11and the lateral side12. Also in the present embodiment, the lateral first portion L1is formed by the heel counter4and the reinforcement member13b. The lower portion of the lateral first portion L1and the lateral side boundary portion120are formed from the reinforcement member13bof the upper, and therefore the lateral first portion L1is more flexurally deformable than the medial first portion M1.

The heel counter4of the present embodiment is formed from a tape material. The heel counter4of the tape material may be bonded and sewn onto the main member of the quarter13.

The tape material has a greater Young's modulus than the main member of the quarter13, and is therefore less stretchable and less bendable than the main member.

On the heel counter4of the present embodiment, the rear second portion B2may not be provided on the rear center portion, and may be provided only on the medial side11ofFIG. 12A. However, the rear second portion B2is provided in the rear end portion15, which is a 20% area of the medial side11extending from the rear end1E.

This embodiment is provided with the lateral second portion L2that connects together the tucked end portion LE of the lateral first portion L1and the rear second portion B2of the heel counter4of Embodiment 1. The lateral second portion L2will slightly reinforce a part of the lateral side boundary portion120ofFIG. 2, and slightly reinforce the midsole2directly under the lateral side boundary portion120.

In this case, it is preferred that the lateral second portion L2of the heel counter4ofFIG. 13Bis tucked between the upper1and the midsole2ofFIG. 2and not exposed to the outside.

A part or whole of the heel counter4may be exposed on the upper1or may be buried in the upper1. Where a part or whole of the heel counter4is exposed on the upper1, it is expected to further improve the stability property and the following property, and is expected to ensure the safety of the upper as a whole.

InFIG. 17, the shoe includes the upper1, the midsole2, the outsole3and the heel counter4.

The upper1includes the lateral side boundary portion120between the upper1and the sole2on the lateral side12of the upper ofFIG. 18, the medial side boundary portion110between the upper1and the sole2on the medial side11of the upper ofFIG. 17, and the rear boundary portion10between the upper1and the sole2in the rear end portion15of the upper ofFIG. 19. The medial side boundary portion110(FIG. 17) and the lateral side boundary portion120(FIG. 18) are continuous with each other with the rear boundary portion10interposed therebetween, as shown inFIG. 19.

The heel counter4made of a thermoplastic resin is attached to the outer surface of the upper1, as shown inFIG. 20AandFIG. 20B. As shown inFIG. 21, the heel counter4includes the rear first portion B1, the rear second portion B2, the lateral first portion L1, the medial first portion M1and the medial second portion M2, which are integrally and seamlessly continuous with each other.

The rear first portion B1ofFIG. 18is placed between the sole2and the top line20of the upper1, in the rear end portion15of the upper. The rear second portion B2is placed in the rear boundary portion10. As shown inFIG. 19, the rear first portion B1and the rear second portion B2of the present embodiment are vertically continuous with each other on the back surface of the upper.

In the example ofFIG. 18, the lateral first portion L1is continuous with the rear first portion B1, and is formed in a strip shape extending on the lateral side12of the upper toward the sole2and toward the diagonal anterior-downward direction.

The medial first portion M1ofFIG. 17is continuous with the rear first portion B1, and extends toward the sole2on the medial side11of the upper. The medial second portion M2is continuous with the rear second portion B2, and extends on the medial side11of the upper along the medial side boundary portion110from the rear second portion B2toward the anterior direction X1. In the case of the present embodiment, the medial first portion M1, the medial second portion M2, the rear second portion B2and the rear first portion B1are continuous with each other, with no through holes or cutouts provided therebetween.

The lateral first portion L1ofFIG. 18extends toward the sole2and toward the anterior direction X1reaching the sole2, and includes the lateral tucked end portion LE that is tucked between the sole2and the upper1. The rear end of the lateral tucked end portion LE and the front end of the rear tucked end portion BE are unconnected and separated from each other in the anterior-posterior direction X. That is, in the case of the present embodiment, the lateral tucked end portion LE and the rear tucked end portion BE are continuous with each other by the strip-shaped lateral first portion L1and the strip-shaped lateral bridge42, but are not continuous with each other below these strip-shaped members.

The rear second portion B2ofFIG. 19extends to the sole2, and includes the rear tucked end portion BE that is tucked between the sole2and the upper1. The medial second portion M2ofFIG. 17includes the medial tucked end portion ME that is tucked between the sole2and the upper1and connects together the rear second portion B2and the lower end portion of the medial first portion M1.

InFIG. 18, the heel counter4includes the lateral bridge42that extends toward the diagonal anterior-upward direction from the rear second portion B2to the lateral first portion L1. Between the lateral bridge42and the lateral first portion L1and the sole2, the exposed portion121is provided where the lateral side boundary portion120of the upper1is exposed.

The lateral first portion L1, the lateral bridge42, the rear second portion B2and the sole2ofFIG. 18define the closed lower area α1. The lower area α1is formed as a cutout of the heel counter4. The exposed portion121is placed in the lower area α1. The lower area α1and the exposed portion121are shaped so as to protrude upward.

With the structure where the lower area α1and the exposed portion121are shaped so as to protrude upward, it is easy to lower the flexural rigidity gradually toward the lateral side boundary portion120. Therefore, with such a structure, the amount of deformation of the lateral side boundary portion120upon heel contact is likely to increase, and it is easy to decrease the pronation.

Examples of the structure in which the flexural rigidity lowers gradually toward the lateral side boundary portion include, in addition to the upwardly-protruding exposed portion of the present embodiment, structures where the volume of a low-rigidity portion, such as an exposed portion or a thin portion having a small thickness, increases gradually downward.

InFIG. 18, the lateral first portion L1, the lateral bridge42, the rear first portion B1and the rear second portion B2define the closed window area α2. In the window area α2, the heel counter4defines the rear through hole Bh running through the heel counter4.

Note that in the case of the present embodiment, the areas α1and α2, which are through holes, are not provided in the medial portion4M ofFIG. 17.

As in the present embodiment, the heel counter4may include a projecting portion49in the medial portion4M ofFIG. 17and the lateral portion4L ofFIG. 18. The projecting portion49extends on the lateral portion4L in the diagonal anterior-upward direction from the lateral bridge42toward the top line20to intersect with the lateral first portion L1.

The other structures of the present embodiment are similar to those of Embodiment 1 ofFIG. 1toFIG. 5described above, and like members are denoted by like reference signs and will not be further described below.

In the case of the present embodiment, the reinforcement device includes both a built-in heel counter4and an external heel counter400.

The built-in heel counter4has a functional feature, and the external heel counter400has a design feature. The external heel counter400is attached to the outer surface of the rearfoot portion of the upper1.

As shown inFIG. 25AandFIG. 25B, the upper1includes an inner skin14placed on the side that comes into contact with the foot, and an outer skin13on the opposite side. The built-in heel counter4is built in between the inner skin14and the outer skin13.

Note thatFIG. 25AandFIG. 25Bare cross sections as seen from the front side of the shoe. InFIG. 25AandFIG. 25B, the midsole2ofFIG. 22andFIG. 23is not shown. The built-in heel counter4is sandwiched between the upper1(the inner skin14) and the midsole2.

As shown inFIG. 24, the built-in counter4includes the rear first portion B1, the rear second portion B2, the lateral first portion L1, the medial first portion M1and the medial second portion M2, which are integrally and seamlessly continuous with each other.

As shown inFIG. 24andFIG. 26, the built-in counter4is plate-shaped as a whole and further includes a low-rigidity portion LW whose rigidity is lower than that of the medial first portion M1and the medial second portion M2, wherein the low-rigidity portion LW is surrounded by the rear first portion B1, the rear second portion B2and the lateral first portion L1.

The built-in counter4ofFIG. 23is plate-shaped as a whole and includes the lateral second portion L2. The lateral second portion L2is continuous with the rear second portion B2, and extends on the lateral side12of the upper along the lateral side boundary portion120from the rear second portion B2toward the anterior direction X1.

The built-in counter4includes a lateral central portion LC surrounded by the rear first portion B1, the rear second portion B2, the lateral first portion L1and the lateral second portion L2. The lateral central portion LC defines a thin portion having a smaller thickness than the surrounding portions, one or more slits, or one or more through holes.

As shown inFIG. 26(g), in the case of the present embodiment, the lateral central portion LC is shown to be a thin portion having a smaller thickness than the surrounding portions. Examples where the lateral central portion LC defines one or more slits or one or more through holes will be described later.

As shown inFIGS. 26(a) to 26(g), the built-in counter4includes a medial central portion MC surrounded by the rear first portion B1, the rear second portion B2, the medial first portion M1and the medial second portion M2. The built-in counter4is plate-shaped as a whole and includes the medial portion4M placed on the medial side and the lateral portion4L placed on the lateral side, which are seamlessly continuous with each other.

The thickness of the lateral central portion LC is smaller than the thickness of the medial central portion MC. In the case of the present embodiment, the average thickness of the lateral portion4L is smaller than the average thickness of the medial portion4M. For example, the lateral central portion LC of the lateral portion4L ofFIGS. 26(c) and 26(f)is a thin portion as shown inFIG. 26(g), and the thin portion further includes a plurality of closed grooves extending in the anterior-posterior direction of the foot. Thus, the low-rigidity portion LW is formed.

FIG. 27shows another example of the structure of the lateral portion4L of the built-in heel counter4ofFIG. 26(c).

As shown inFIGS. 27(a) and 27(d), the lateral portion4L of the heel counter4may include one through hole4H or a plurality of through holes4H arranged in a scattered pattern provided in the lateral central portion LC.

As shown inFIGS. 27(b) and 27(c), the built-in counter4may be plate-shaped as a whole with a lower edge, and the lower edge may be formed in an upward arch shape between the lateral tucked end portion LE and the rear tucked end portion BE.

As shown inFIGS. 27(e) and 27(f), the through holes4H may be groove-shaped extending in the anterior-posterior direction in the lateral central portion LC. The grooves may have the same length or different lengths. The direction in which the slits extend may be inclined, and there is no limitation on the direction of inclination.

Moreover, the number of groove-shaped through holes4H may be one, though it is not shown in the figures.

As shown inFIGS. 27(g) and 27(h), the through holes4H may be triangular or polygonal.

In the case ofFIGS. 27(a) to 27(h), the through hole4H may be a thin portion that is thin and recessed, thereby forming the low-rigidity portion LW.

FIG. 28shows another example of a built-in heel counter.

In this example, the heel counter4has a flat plate shape, and is built in the rearfoot portion of the upper while being bent along a center line4C into a generally U-letter shape.

InFIG. 28, the counter4may include a low-rigidity portion LW formed in the lateral central portion LC by providing a plurality of slits in the lateral central portion LC. The slits may extend in the anterior-posterior direction in the lateral central portion LC. Also in this case, there may be one slit or a plurality of slits.

When the built-in heel counter is installed in the upper, no external heel counter may be provided.

FIG. 29shows, together with a part of the upper1, another example of an external heel counter4.

InFIG. 29, a thin portion400is provided to extend from the rear end of the external heel counter4toward the medial side and the lateral side. The distance40M from the rear end to the front end of the thin portion400in the medial portion4M ofFIG. 29(a)is shorter than the distance40L in the lateral portion4L ofFIG. 29(b). The external heel counter4is dotted, and the thin portion400are densely dotted.

Note that the two-dot-chain line denotes the upper edge line of the midsole.

A pattern of small protrusions/depressions may be provided in a portion of the external heel counter4.

In the present embodiment, the external heel counter4is provided with eyelets401through which shoelaces are passed. A through hole402may be provided in the vicinity of the eyelets401.

Note that the external heel counter4of the present embodiment will allow the upper to be in close contact with the heel.

FIG. 30shows still another example of the external heel counter4.

In the present embodiment, a bridge404forming a through hole403is provided to extend from the rear end of the external heel counter4to the lateral side and the medial side. In the case of the present embodiment, because of the bridge of the rear end portion, the lateral portion4L ofFIG. 30(a)has a lower rigidity than the medial portion4M ofFIG. 30(b).

While preferred embodiments have been described above with reference to the drawings, various obvious changes and modifications will readily occur to those skilled in the art upon reading the present specification.

The sole placed under the upper may include only a so-called “outsole”.

When the heel counter is a built-in heel counter, the heel counter may be a thick cardboard or a cardboard impregnated with a resin, as well as a thermoplastic resin.

Thus, such changes and modifications are deemed to fall within the scope of the present invention, which is defined by the appended claims.

INDUSTRIAL APPLICABILITY

The present invention is applicable to athletic shoes such as running shoes and also to various other types of shoes such as walking shoes.

REFERENCE SIGNS LIST

Mh: Medial through hole