Shoe

Abstract

To provide a shoe capable of reducing air resistance.SOLUTION: A shoe 1 comprises an upper part 10 for covering an instep, a sole part 20 fixed to the upper part 10, and an air resistance reduction part 30 which is provided at a back end of the upper part 10 and which assumes a streamlined shape pointed backward. The streamlined shape of the air resistance reduction part 30 continues into a back end 21 of the sole part 20. The shape like this can enhance an aero effect of a heel part and reduce air resistance.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to shoes, and more particularly to shoes for sports that compete for speed.

Background Art

[0002] In recent years, in the world of bicycle racing, in order to reduce air resistance during running, designs specialized in aerodynamics have been remarkable (see, for example, Non-Patent Document 1). Due to the evolution of equipment, the speed of road racing is increasing more and more. Since it often exceeds 70 km / h even on flat roads and exceeds 100 km / h on downhill slopes, air resistance during running is a major issue.

[0003] Therefore, professional athletes choose items specialized for bicycle racing not only for road bikes but also for helmets and wear. Items for enhancing the aerodynamic effect of the lower limbs include aerosocks and aeroshoe covers, and experiments comparing the effects of both are also known (see, for example, Non-Patent Document 2). There is also an experimental result that air resistance can be reduced by 7% by performing calf hair treatment (see, for example, Non-Patent Document 3). If air resistance can be reduced by 7%, in a competition called "time trial" where the time to run a distance of 40 km is competed, theoretically, the time can be shortened by 79 seconds when reaching the goal after 1 hour. For athletes who sometimes compete with a difference of one-hundredth of a second, this will create a very large advantage.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Non-Patent Documents

[0005]

Non-Patent Document 1

Non-Patent Document 2

Non-Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, the development of enhancing the aerodynamic effect of the shoes themselves has not yet advanced significantly. This is evident from the photos of the shoes used by the world's top-class athletes disclosed in Non-Patent Document 1. Although Non-Patent Document 1 shows the importance of the shoes in terms of "being the contact point for transmitting force to the road bike", it does not mention reducing the air resistance acting on the shoes.

[0007] Patent Document 1 discloses shoes with an air resistance reducing device attached to the rear of the shoes, which has a streamlined shape. However, it is not practical to use these shoes as sports shoes. That is, since the air resistance reducing device disclosed in Patent Document 1 is detachable from the shoes (see lines 9 to 13 on page 6 of Patent Document 1), there is a risk of falling off during sports that involve intense leg movement, and there are safety issues. Also, at the lower end of the air resistance reducing device, an opening is formed between the device and the shoes (see Figure 1 of Patent Document 1). When the legs are moved vigorously, air enters the opening, which becomes a factor increasing the air resistance.

[0008] The present invention solves such problems and aims to provide shoes capable of reducing air resistance.

Means for Solving the Problems

[0009] One aspect of the present invention is a shoe, comprising an upper part covering the instep, a sole part fixed to the upper part, and at the rear end of the upper part, a streamlined air resistance reducing part pointed rearward, wherein the streamlined shape of the air resistance reducing part is continuous with the rear end of the sole part.

Effects of the Invention

[0010] According to the present invention, it is possible to provide shoes capable of reducing air resistance.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Modes for Carrying Out the Invention

[0012] Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the embodiments described below are merely examples. The drawings are schematic and may differ from reality. Also, there may be parts where the dimensional relationships and ratios are different between the drawings.

[0013] "Regarding Air Resistance" There are two types of air resistance: frictional resistance and pressure resistance. Frictional resistance is the air resistance caused by the friction between the fluid and the surface of the object. Pressure resistance is the air resistance generated by the separation of the flow and is the air resistance caused by the pressure difference between the front and back of the object. The present invention enhances the aerodynamic effect in the heel (heel part) of the shoe and reduces the pressure resistance.

[0014] "Aerodynamic Heel Shoes" Figs. 1 to 4 are external views of the shoe 1 in the embodiment of the present invention. Fig. 1 is a side view, Fig. 2 is a plan view, Fig. 3 is a bottom view, and Fig. 4 is a rear view. Since the inventor is a track cyclist, here, a racing shoe for track cycling will be exemplified and described. Only the left-foot shoe 1 will be exemplified and described, but the same applies to the right-foot shoe 1. In the following description, the terms "up and down, left and right" are considered based on the plan view of Fig. 2 unless otherwise specified.

[0015] As shown in Figs. 1 to 4, this shoe 1 is a racing shoe for track cycling and includes an upper part 10 that covers the instep and a sole part 20 fixed to the upper part 10. An opening 11 through which the foot is inserted is formed in the upper part 10. The opening 11 can be closed with shoelaces 12 from the upper left and right sides, and the tightness can be adjusted with a hook-and-loop fastener 13 to enhance the fit.

[0016] The characteristic point of this shoe 1 lies in its heel shape. That is, at the rear end of the upper part 10, there is a streamlined air resistance reduction part 30 that tapers backward, and the streamlined shape of the air resistance reduction part 30 is continuous with the rear end 21 of the shoe sole part 20. With such a shape, the aerodynamic effect in the heel part is enhanced, and it becomes possible to reduce air resistance.

[0017] 《Air Resistance Reduction Part》 Hereinafter, with reference to FIGS. 1 to 4, the shape of the air resistance reduction part 30 will be described in more detail. In the present invention, in order to enhance the aerodynamic effect in the heel part, the following shape is adopted.

[0018] First, as shown in FIG. 1, in a side view, the air resistance reduction part 30 is smoothly formed in a substantially arc shape from its upper end 31 to its lower end 32, and this arc is continuous with the rear end 21 of the shoe sole part 20. The use of the word "substantially" as in "substantially arc-shaped" means that even if it is not a mathematically exact arc, any shape that can be recognized as approximately an arc is acceptable. By changing the shape gently in this way, the air flow is less likely to separate from the shoe surface.

[0019] Also, as shown in FIG. 2, in a plan view, the air resistance reduction part 30 is formed in a substantially V shape that is continuous with the opening edge 11. In this way, by smoothly tapering the heel shape of the shoe 1, the overall shape of the shoe 1 becomes closer to a teardrop shape, and the air flow is less likely to separate from the shoe surface.

[0020] Also, as shown in FIG. 3, in a bottom view, the entire adjacent part (the part indicated by the dotted line) B between the air resistance reduction part 30 and the shoe sole part 20 is smoothly continuous. In this way, even when the lower limbs are moved vigorously, the problem of increased air resistance as in Patent Document 1 does not occur.

[0021] Further, as shown in FIG. 4, the air resistance reduction part 30 is formed in a scallop shape that tapers from near its upper end 31 to near its lower end 32, and the line where the left side part 30L and the right side part 30R of the air resistance reduction part 30 meet forms a ridge line 33. That is, as shown by the dashed line in FIG. 4, the left side part 30L of the air resistance reduction part 30 corresponds to the left shell of the scallop, the right side part 30R of the air resistance reduction part 30 corresponds to the right shell of the scallop, and the part where they meet is pointed. FIG. 4 is a view of the scallop in the open state as seen from the opening side. Explaining from another angle, as shown in FIG. 3, the air resistance reduction part 30 is formed in a substantially V shape with a slightly rounded bulge outward. Looking at FIG. 3, it can be seen that the air resistance reduction part 30 is similar to the shape of the scallop in the closed state as seen from the side. With such a scallop shape, it is possible to reduce air resistance when pulling up or pushing down the pedal. This is easy to understand considering the ease of movement in water.

[0022] 《Cleat》 As shown in FIG. 3, a cleat 40 for fixing the foot to the bicycle pedal is detachably attached to the shoe sole 20 with bolts 42 or the like. The attachment position of the cleat 40 is also adjustable. A groove 41 for engaging with the edge (like a step) of the pedal is formed in the cleat 40. The edge of the pedal is fitted into this groove 41, and the shoe 1 is fixed to the pedal using toe clips and clip bands. In this way, since the shoe 1 does not shift forward, backward, left, or right, the force of the foot is firmly transmitted to the bicycle, making it possible to achieve efficient pedaling.

[0023] 《Principle》 FIG. 5 is a schematic diagram for explaining the effect of the shoe 1 in the embodiment of the present invention. Hereinafter, with reference to FIG. 5, the principle of reducing air resistance will be explained in more detail. Here, the explanation will focus on the air resistance from the front (the traveling direction of the bicycle 100).

[0024] First, as shown in Fig. 5(A), the rear end of the upper part 10A of a general shoe 1A has a shape along the opening edge 11A. Therefore, the air flow hits the front of the shoe 1A as shown by the arrow in the figure, branches to the left and right and passes through the sides, and then peels off from the shoe surface due to a sharp turn at the rear end of the upper part 10A. As a result, vortices are generated behind the shoe 1A, increasing the pressure resistance.

[0025] On the other hand, as shown in Fig. 5(B), the rear end of the upper part 10 of the shoe 1 in the embodiment of the present invention smoothly changes its shape rearward from the opening edge 11, and the rearmost end E is pointed. As a result, the air flows that were branched to the left and right smoothly merge at the rearmost end E. Although the frictional resistance increases due to the increase in the surface area compared to the general shoe 1A, peeling hardly occurs, so the pressure resistance is significantly reduced. As a result, overall, it is possible to significantly reduce the air resistance compared to the general shoe 1A.

[0026] 《Usage Scenario Example》 Fig. 6 is a schematic diagram showing a usage scenario example of the shoe 1 in the embodiment of the present invention. Here, it shows a track cyclist U wearing the shoe 1, an aerodynamic helmet 2, an aerodynamic suit 3, and aerodynamic socks 4, and fixing the feet to the pedals 102 and traveling at high speed. It is assumed that the shoe 1 is provided with a bivalve-shaped air resistance reduction part 30.

[0027] As can be seen from Fig. 6, during high-speed travel, the lower limbs move more violently compared to the upper body and head. Since the air is disturbed at the thigh and calf parts, air flow turbulence occurs, and the shoe receives extra air resistance. Since pedaling is a circular motion centered on the axis J of the crank 101, the shoe 1 is moving in a circular motion while moving at high speed in the traveling direction of the bicycle 100. Among such air flow turbulences caused by pedaling, if the rear end shape of the shoe 1 is bivalve-shaped, it is possible to smoothly and quickly pedal.

[0028] 《Side Shape》 FIG. 7 is a schematic view showing the side shape of the shoe 1 in the embodiment of the present invention. Hereinafter, with reference to FIG. 7, the side shape of the shoe 1 will be described in more detail.

[0029] As already described, the air resistance reduction portion 30 is formed in a substantially arc shape from its upper end 31 to its lower end 32 in a side view, and this arc is continuous with the rear end 21 of the shoe bottom portion 20. As long as such conditions are satisfied, the shape of the arc portion is not particularly limited, and various modifications are possible.

[0030] For example, as shown in FIG. 7(A), it may be formed in an arc shape of a vertically long ellipse C1 having the major axis from the upper end 31 to the lower end 32. Also, as shown in FIG. 7(B), it may be formed in an arc shape of a perfect circle C2 having the diameter from the upper end 31 to the lower end 32. Further, as shown in FIG. 7(C), it may be formed in an arc shape of a horizontally long ellipse C3 having the minor axis from the upper end 31 to the lower end 32. Any of these shapes is effective in reducing air resistance when the lower limbs are moved vigorously (especially when accompanied by rotational movement). However, if it becomes too horizontally long, there is a risk of increasing air resistance, so it is desirable to be formed in an arc shape of the vertically long ellipse C1 or the arc shape of the perfect circle C2.

[0031] 《Position relationship with the crank》 FIG. 8 is a schematic view showing the position relationship between the shoe 1 and the crank 101 in the embodiment of the present invention. Generally, the position where the ball of the big toe just rides directly above the pedal shaft protruding at a right angle from the crank 101 is regarded as an efficient stepping position, but there are individual differences in this stepping position. For example, as shown in FIG. 8(A), there are people who want to place their feet at a position where the inner surface of the shoe 1 is substantially parallel to the crank 101, and as shown in FIG. 8(B), there are also people who want to place their feet slightly outward. In any case, in a plan view, it is desirable that a virtual line (the dashed-dotted line in the figure) obtained by extending the ridge line 33 of the air resistance reduction portion 30 is substantially orthogonal to the groove 41 of the cleat 40. With such a position relationship, air from the front (the traveling direction of the bicycle 100) can be efficiently discharged rearward.

[0032] 《Manufacturing Method》 The manufacturing method of the shoe 1 in the embodiment of the present invention is not particularly limited, nor is the material of each part particularly limited. For example, the upper part 10 may be assembled by sewing with a soft material such as leather, and the sole part 20 may be manufactured by injection molding with a resin or the like. The air resistance reduction part 30 may be integrally manufactured with the same material as the upper part 10 or the same material as the sole part 20, or only the inside of the air resistance reduction part 30 may use a lightweight material such as sponge. Of course, it is possible to appropriately select the optimal material for each part in consideration of ease of walking and power loss. Also, as shown in FIG. 9, the entire rear part of the shoe 1 including the air resistance reduction part 30 may be covered with a material 34 such as plastic. In any case, it is only necessary that the surface of the rear part of the shoe 1 is formed smoothly. Of course, such a shoe 1 can be manufactured in a single-piece manner for each individual, or can be manufactured in a mass production manner to suit many people.

[0033] 《Characteristic Configuration of the Present Invention and Its Effects》 As described above, the shoe 1 in the embodiment of the present invention includes an upper part 10 that covers the instep, a sole part 20 fixed to the upper part 10, and an air resistance reduction part 30 having a streamlined shape that tapers backward at the rear end of the upper part 10, and the streamlined shape of the air resistance reduction part 30 is continuous with the rear end 21 of the sole part 20. With such a shape, the aerodynamic effect at the heel (heel part) is enhanced, and it becomes possible to reduce air resistance.

[0034] Specifically, it is desirable that the air resistance reduction part 30 is formed in a substantially arc shape from its upper end 31 to its lower end 32 in a side view. If the shape is changed gently in this way, the air flow is less likely to separate from the shoe surface.

[0035] Also, it is desirable that the air resistance reduction part 30 is formed in an arc shape of a vertically long ellipse C1 or an arc shape of a perfect circle C2 in a side view. This is because if it becomes too horizontally long, there is a possibility that the air resistance will increase.

[0036] Further, it is desirable that the air resistance reducing portion 30 is formed in a substantially V shape continuous with the entrance 11 which is the portion where the foot is inserted in plan view. In this way, if the trailing edge shape of the shoe 1 is smoothly tapered, the overall shape of the shoe 1 will be closer to a teardrop shape, and the air flow will be less likely to separate from the shoe surface.

[0037] Also, it is desirable that in bottom view, the entire adjacent portion of the air resistance reducing portion 30 with the sole portion 20 is smoothly continuous. In this way, even when the lower limbs are moved vigorously, the problem of increased air resistance as in Patent Document 1 does not occur.

[0038] Further, the air resistance reducing portion 30 is formed so as to form a pointed bivalve shape from near the upper end 31 to near the lower end 32, and it is desirable that the line where the left side portion 30L and the right side portion 30R meet becomes the ridge line 33. With such a bivalve shape, it is possible to reduce air resistance both when pulling up and when lowering the pedal.

[0039] Also, a cleat 40 for fixing the foot to the pedal of the bicycle 100 is attached to the sole portion 20, and in plan view, it is desirable that a virtual line extending the ridge line 33 of the air resistance reducing portion 30 is substantially orthogonal to the groove 41 of the cleat 40. With such a positional relationship, air from the front (the traveling direction of the bicycle 100) can be efficiently discharged rearward.

[0040] In the above description, a racing shoe for track cycling is exemplified, but the application range of the present invention is not limited thereto. That is, the present invention can be applied to shoes for all sports that require reduction of air resistance, such as skating and marathon. It has the potential to be the prototype of all sports equipment that competes for speed, and can be said to be a very practical invention.

Explanation of Reference Numerals

[0041] 1 Shoe 10 Upper portion 11 Entrance 20 Sole portion Rear end of the shoe sole 30 Air resistance reduction part 31 Upper end of the air resistance reduction part 32 Lower end of the air resistance reduction part 33 Ridge line of the air resistance reduction part 40 Cleat 41 Groove of the cleat 100 Bicycle 101 Crank 102 Pedal

Claims

1. An upper part covering the instep, A sole part fixed to the upper part, and at the rear end of the upper part, a streamline-shaped air resistance reducing part that tapers backward, A shoe in which the streamline shape of the air resistance reducing part is continuous with the rear end of the sole part.

2. The shoe according to claim 1, wherein the air resistance reducing part is formed in a substantially arc shape from its upper end to its lower end in a side view.

3. The shoe according to claim 2, wherein the air resistance reducing part is formed in an arc shape of a vertically long ellipse or a perfect circle in a side view.

4. The shoe according to claim 1, wherein the air resistance reducing part is formed in a substantially V shape that is continuous with the opening of the shoe, which is the part where the foot is inserted, in a plan view.

5. The shoe according to claim 1, wherein in a bottom view, the entire adjacent part of the air resistance reducing part and the sole part is smoothly continuous.

6. The shoe according to claim 1, wherein the air resistance reducing part is formed in a shape of a pointed bivalve shell from near its upper end to near its lower end, and the line where the left side part and the right side part meet becomes a ridge line.

7. A cleat for fixing the foot to a bicycle pedal is attached to the sole part, The shoe according to claim 6, wherein in a plan view, a virtual line extending the ridge line of the air resistance reducing part is substantially orthogonal to the groove of the cleat.

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