JP4481927B2 - Tennis shoes - Google Patents

Description

  The present invention relates to tennis shoes. Specifically, the present invention relates to an improvement in the bottom surface of a tennis shoe.

In a tennis rally, the player makes a stroke while moving violently through the court. The player predicts the direction of the ball from the opponent's stroke and moves toward the target point. Movement takes place when the foot kicks the ground. When approaching the target point, the player stops the kick and adjusts the posture of the stroke. After this, the player's feet slide with the ground. Although it is a short distance, the player's body moves forward by sliding. Most of the movement to the target point is by kick, but the final stage of movement is by slide. The player who reaches the target point makes a stroke. The player then flips his body, kicks the ground and moves to the next target point.
In the movement by kick, it is preferable that the tennis shoe and the ground do not slip. Tennis shoes are required to have anti-slip performance. On the other hand, in the movement by the slide, it is preferable that the tennis shoe and the ground slip appropriately. Tennis shoes are required to have sliding performance. Japanese Patent Application Laid-Open No. 7-213304 discloses a tennis shoe in which both the anti-slip performance and the slide performance are achieved by devising the planar shape of the protrusion on the bottom surface.
Even the tennis shoes disclosed in the above publication do not have both anti-slip performance and slide performance. An object of the present invention is to provide a tennis shoe excellent in anti-slip performance and sliding performance.

The tennis shoe according to the present invention includes a large number of muscle mountains arranged in parallel on the bottom surface. The cross-sectional shape of the streak is asymmetric. The ratio (μa / μb) between the friction coefficient μa in one direction of the bottom surface and the friction coefficient μb in the opposite direction is 0.3 or more and 0.9 or less. This tennis shoe is excellent in sliding performance in one direction and anti-slip performance in the reverse direction.
A tennis shoe according to another invention includes a large number of horizontal muscles extending in the width direction on the bottom surface. The cross-sectional shape of this horizontal streak is asymmetric. The ratio (μa / μb) between the friction coefficient μa in the toe direction on the bottom surface and the friction coefficient μb in the heel direction is 0.3 or more and 0.9 or less. This tennis shoe is excellent in sliding performance in the toe direction and anti-slip performance in the heel direction.
The horizontal streak includes a grounding surface and a toe side wall surface and a heel side wall surface continuous with the grounding surface. Preferably, the difference (θb−θa) between the inclination angle θa of the toe side wall surface and the inclination angle θb of the heel side wall surface is 10 ° or more and 60 ° or less. The preferred height of the horizontal streak is 1 mm or more and 8 mm or less.
Preferably, the tennis shoe includes a vertical muscle mountain as well as a horizontal muscle mountain. This vertical streak extends in the length direction. A horizontal streak is mainly formed in a region of the bottom surface closer to the toe than the center in the length direction and outside the center in the width direction. A vertical streak is mainly formed in a region of the bottom surface closer to the toe than the center in the length direction and inside the center in the width direction. This tennis shoe is excellent in sliding performance and anti-slip performance when moving forward and anti-slip performance when changing direction.
Further, a tennis shoe according to another invention has a large number of horizontal muscles and vertical muscles on its bottom surface. The ratio R1 of the ground contact area of Yokosuji that occupies the total ground contact area in the toe portion is 40% or more and 70% or less. The ratio R2 of the ground contact area of the vertical streak occupying the total ground contact area in the inside portion is 70% or more and 100% or less. This tennis shoe is excellent in anti-slip performance and sliding performance.
Preferably, the cross-sectional shape in the shoe length direction of the horizontal muscle mountain is asymmetric, and the cross-sectional shape in the shoe width direction of the vertical muscle mountain is also asymmetric. The friction coefficient μa in the toe direction between the bottom surface and the ground contact surface is smaller than the friction μb in the heel direction, and the ratio (μa / μb) between μa and μb is 0.3 or more and 0.9 or less.
Preferably, the ratio R1 is not less than 45% and not more than 65%, and the ratio R2 is not less than 75% and not more than 95%. Preferably, the ratio R1 is 50% or more and 60% or less, and the ratio R2 is 80% or more and 90% or less.

FIG. 1 is a side view showing a tennis shoe according to an embodiment of the present invention,
FIG. 2 is a bottom view showing the tennis shoe of FIG.
FIG. 3 is a perspective view from below showing a part of the sole of FIG.
FIG. 4 is an enlarged sectional view showing a part of the sole of FIG.
FIG. 5 is a sectional view showing a part of a sole of a tennis shoe according to another embodiment of the present invention,
FIG. 6 is a sectional view showing a part of a sole of a tennis shoe according to still another embodiment of the present invention,
FIG. 7 is a bottom view showing a sole of a tennis shoe according to still another embodiment of the present invention,
FIG. 8 is an enlarged sectional view showing a part of the sole of FIG.
FIG. 9 is a bottom view showing a sole of a tennis shoe according to still another embodiment of the present invention;
FIG. 10 is a perspective view from below showing a part of the sole of FIG.
FIG. 11 is an enlarged sectional view showing a part of the sole of FIG.
FIG. 12 is an enlarged sectional view showing a part of the sole of FIG.
FIG. 13 is a bottom view showing a part of a sole according to still another embodiment of the present invention,
FIG. 14 is a bottom view showing a sole of a tennis shoe according to still another embodiment of the present invention,
And
FIG. 15 is an enlarged bottom view showing a part of the sole of FIG.

  Hereinafter, the present invention will be described in detail based on embodiments with appropriate reference to the drawings.
  The tennis shoe 1 shown in FIG. 1 includes an upper 3 and a sole 5. The material of the upper 3 is equivalent to that of a known tennis shoe. The material of the sole 5 is the same as that of a known tennis shoe. Generally, the sole 5 is composed of a crosslinked rubber or a synthetic resin.
  FIG. 2 shows the sole 5. In FIG. 2, the upper side is the toe side, the lower side is the heel side, the right side is the outside, and the left side is the inside. This sole 5 is for the left foot. The sole for the right foot has a shape obtained by inverting the shape shown in FIG.
  The sole 5 includes a base 7 and a large number of transverse muscle mountains 9. The horizontal streak 9 is formed integrally with the base 7 and protrudes from the base 7. The horizontal streak 9 extends in the width direction (left-right direction in FIG. 2). A large number of horizontal stripes 9 are arranged in parallel at a predetermined interval. In the area corresponding to the arch, the horizontal streak 9 does not exist. In the present specification, the horizontal streak 9 means a streak extending in a direction substantially orthogonal to the length direction of the sole 5. Preferably, the direction in which the horizontal stripes 9 extend is 80 ° or more and 100 ° or less with respect to the length direction of the sole 5.
  FIG. 3 is a perspective view from below showing a part of the sole 5 of FIG. 2, and FIG. 4 is an enlarged sectional view showing a part thereof. In these figures, the left side is the toe side and the right side is the heel side. As is apparent from FIGS. 3 and 4, the cross-sectional shape of the horizontal streak 9 is asymmetric. The horizontal streak 9 includes a grounding surface 11, a toe side wall surface 13, and a heel side wall surface 15. The ground contact surface 11 is a surface in contact with the ground when the tennis shoe 1 is worn. The toe side wall surface 13 is continuous to the ground contact surface 11 and is located closer to the toe side than the ground contact surface 11. The heel side wall surface 15 is continuous with the ground contact surface 11 and is located on the heel side with respect to the ground contact surface 11.
  In FIG. 4, what is indicated by a double arrow θa is the inclination angle of the toe side wall surface 13. The inclination angle θa is an angle formed by the toe side wall surface 13 with respect to the horizontal plane G (ground). In FIG. 4, what is indicated by a double-headed arrow θb is the inclination angle of the heel side wall surface 15. The inclination angle θb is an angle formed by the side wall surface 15 with respect to the horizontal plane G. The inclination angle θb is larger than the inclination angle θa.
  When the tennis shoe 1 is placed on the ground and pulled in the toe direction, the pulling force is mainly applied to the toe side wall surface 13. Since the inclination of the toe side wall surface 13 is gentle, the friction coefficient μa between the ground surface and the bottom surface is small. When the player slides the shoe, the sliding direction is the toe direction. Since this tennis shoe 1 has a small coefficient of friction μa, it has excellent sliding performance. A player wearing this tennis shoe 1 can smoothly transition from movement to stroke. The slide also contributes to mitigating impact when landing.
  When the tennis shoe 1 is placed on the ground and pulled in the heel direction, the pulling force is mainly applied to the heel side wall surface 15.傾斜 Since the inclination of the side wall surface 15 is tight, the friction coefficient μb between the ground and the bottom surface is large. When a player moves forward by kicking the ground, the kick direction is the heel direction. Since the tennis shoe 1 has a large friction coefficient μb, the tennis shoe 1 is excellent in anti-slip performance when kicking.
  From the viewpoint of achieving both slide performance and anti-slip performance, the ratio (μa / μb) between the friction coefficient μa and the friction coefficient μb is preferably 0.9 or less, and more preferably 0.7 or less. If the ratio (μa / μb) is too small, unintentional slip in the toe direction tends to occur, so the ratio (μa / μb) is preferably 0.3 or more, and more preferably 0.5 or more.
  The coefficient of friction is measured on artificial grass with sand having the conditions shown in the following (1) and (2).
  (1) Pile
      Material: Polypropylene
      Shape: Split yarn
      Thread: 8400 dtex
      Pile latitude density (gauge): 5/16 inch spacing
      Pile warp density (stitch): 4.8 / inch
      Height from the base fabric surface to the leaf tip: 19 mm
  (2) Sand to be filled
      Type: Dried particle size-adjusted sand (trade name “Omni Sand A” by Sumitomo Rubber Industries)
      Filling amount: 25kg / m²
      Filling height: Filled to leave 2 mm of artificial turf leaf tip
  In the measurement, a vertical load of 600 N is applied to the tennis shoe 1 on the artificial grass with sand, and a horizontal force is applied so that the tennis shoe 1 is pulled in a predetermined direction at a speed of 50 cm / s. The pulling force is detected by the load cell, and the pulling force is divided by the vertical load to calculate the friction coefficient. The measurement is performed in an environment of 20 ° C.
  From the viewpoint of achieving both slide performance and anti-slip performance, the difference (θb−θa) is preferably 10 ° (degree) or more, and more preferably 20 ° or more. If the difference (θb−θa) is excessive, an unintended slip in the toe direction is likely to occur. Therefore, the difference (θb−θa) is preferably 60 ° or less, and more preferably 50 ° or less. The inclination angle θa is preferably 30 ° or greater and 70 ° or less. The inclination angle θb is preferably 50 ° or more and 90 ° or less.
  The height H of the horizontal streak 9 is preferably 1 mm or more and 8 mm or less. When the height H is less than the above range, the anti-slip performance may be insufficient. In this respect, the height H is more preferably 2 mm or more. If the height H exceeds the above range, the stiffness of the horizontal streak 9 may be insufficient. In this respect, the height H is more preferably 6 mm or less.
  The ratio (L2 / L1) of the distance L2 of the ground plane 11 to the distance L1 of the boundary portion between the base 7 and the horizontal streak 9 is preferably 0.2 or more and 0.8 or less. If the ratio (L2 / L1) is less than the above range, the stiffness of the horizontal stripe 9 may be insufficient. In this respect, the ratio (L2 / L1) is more preferably equal to or greater than 0.3. When the ratio (L2 / L1) exceeds the above range, the contact pressure may be insufficient and the anti-slip performance may be insufficient. In this respect, the ratio (L2 / L1) is particularly preferably equal to or less than 0.6.
  The ratio of the total area of all the ground planes to the projected area of the bottom surface is preferably 15% or more and 70% or less. When the ratio is less than the above range, the ground contact surface is likely to be worn. From this viewpoint, the ratio is more preferably 25% or more. If the ratio exceeds the above range, the contact pressure may be insufficient and the anti-slip performance may be insufficient. From this viewpoint, the ratio is more preferably 60% or less.
  In the tennis shoe 1 shown in FIG. 2, the muscle mountain 9 extends in the width direction, but the muscle mountain may extend in the other direction. Also in this case, excellent sliding performance is achieved in one direction perpendicular to the muscle mountain, and excellent anti-slip performance is achieved in the reverse direction.
  FIG. 5 is a sectional view showing a part of a sole 17 of a tennis shoe according to another embodiment of the present invention. In this figure, the horizontal stripe 19 and the base 21 are shown. In this figure, the left side is the toe side, and the right side is the heel side. The cross-sectional shape of the horizontal streak 19 is asymmetric. The horizontal streak 19 includes a grounding surface 23, a toe side wall surface 25, and a heel side wall surface 27. The toe side wall surface 25 is curved. Similar to the sole 5 shown in FIG. 2, the sole 17 includes a large number of horizontal streaks 19 arranged in parallel.
  In FIG. 5, what is indicated by a two-dot chain line is a virtual line connecting a boundary point P1 between the ground contact surface 23 and the toe side wall surface 25 and a boundary point P2 between the base 21 and the toe side wall surface 25. is there. The angle formed by the imaginary line and the horizontal line G is the inclination angle θa of the toe side wall surface 25. Also in this sole, the inclination angle θa is preferably 30 ° or more and 70 ° or less. On the other hand, the side wall surface 27 inclination angle θb is preferably 50 ° or more and 90 ° or less. From the viewpoint of achieving both sliding performance and anti-slip performance, the difference (θb−θa) is preferably 10 ° or more, and more preferably 20 ° or more. If the difference (θb−θa) is excessive, an unintended slip in the toe direction is likely to occur. Therefore, the difference (θb−θa) is preferably 60 ° or less, and more preferably 50 ° or less.
  In the sole 17 as well, the height H of the horizontal streak 19 is preferably 1 mm or more and 8 mm or less. Also in the sole 17, the ratio (L2 / L1) is preferably 0.2 or more and 0.8 or less.
  Also in the sole 17, the ratio (μa / μb) between the friction coefficient μa and the friction coefficient μb is preferably 0.9 or less, and more preferably 0.7 or less, from the viewpoint of achieving both sliding performance and anti-slip performance. If the ratio (μa / μb) is too small, unintentional slip in the toe direction tends to occur, so the ratio (μa / μb) is preferably 0.3 or more, and more preferably 0.5 or more.
  FIG. 6 is a cross-sectional view showing a part of a sole 29 of a tennis shoe according to still another embodiment of the present invention. In this figure, the horizontal streak 31 and the base 33 are shown. In this figure, the left side is the toe side, and the right side is the heel side. The cross-sectional shape of the horizontal streak 31 is asymmetric. The horizontal streak 31 includes a grounding surface 35, a toe side wall surface 37, and a heel side wall surface 39. The ground surface 35 is curved. The grounding surface 35 is narrower than the grounding surface 11 of the horizontal streak 9 shown in FIG. Similar to the sole 5 shown in FIG. 2, the sole 29 includes a large number of horizontal streak 31 arranged in parallel.
  Also in the sole 29, the inclination angle θa formed by the toe side wall surface 37 with respect to the horizontal plane is preferably 30 ° or more and 70 ° or less. On the other hand, the inclination angle θb formed by the side wall surface 39 with respect to the horizontal plane is preferably 50 ° or more and 90 ° or less. From the viewpoint of achieving both sliding performance and anti-slip performance, the difference (θb−θa) is preferably 10 ° or more, and more preferably 20 ° or more. If the difference (θb−θa) is excessive, an unintended slip in the toe direction is likely to occur. Therefore, the difference (θb−θa) is preferably 60 ° or less, and more preferably 50 ° or less.
  Also in this sole 29, the height H of the horizontal streak 31 is preferably 1 mm or more and 8 mm or less. Also in the sole 29, the ratio (L2 / L1) is preferably 0.2 or more and 0.8 or less.
  In the sole 29 as well, the ratio (μa / μb) between the friction coefficient μa and the friction coefficient μb is preferably 0.9 or less, and more preferably 0.7 or less, from the viewpoint of achieving both sliding performance and anti-slip performance. If the ratio (μa / μb) is too small, unintentional slip in the toe direction tends to occur, so the ratio (μa / μb) is preferably 0.3 or more, and more preferably 0.5 or more.
  FIG. 7 is a bottom view showing a sole 41 of a tennis shoe according to still another embodiment of the present invention. In FIG. 7, the upper side is the toe side, the lower side is the heel side, the right side is the outside, and the left side is the inside. The sole 41 is for the left foot. The sole for the right foot has a shape obtained by inverting the shape shown in FIG.
  The sole 41 includes a base 43, a large number of horizontal stripes 45, and a large number of vertical stripes 47. The horizontal stripe 45 and the vertical stripe 47 are formed integrally with the base 43 and protrude from the base 43. The horizontal streak 45 extends in the width direction (left-right direction in FIG. 7). The vertical streak 47 extends in the length direction (vertical direction in FIG. 7). In the present specification, the vertical streak 47 means a streak extending substantially parallel to the length direction of the sole 41. Preferably, the direction in which the vertical streak 47 extends is −10 ° to 10 ° with respect to the length direction of the sole 41. The cross-sectional shape and dimensions of the horizontal stripes 45 are the same as the cross-sectional shape of the horizontal stripes 9 shown in FIG.
  FIG. 8 is an enlarged cross-sectional view showing a part of the sole 41 of FIG. In FIG. 8, a vertical streak 47 is shown. In FIG. 8, the left side is the inside and the right side is the outside. As is apparent from FIG. 8, the vertical streak 47 includes a ground contact surface 49, an inside wall surface 51, and an outside wall surface 53. The inclination angle θc with respect to the horizontal direction of the inside wall surface 51 is gentler than the inclination angle θd with respect to the horizontal direction of the outside wall surface 53.
  A one-dot chain line CL1 shown in FIG. 7 is a center line in the length direction. When the longest line segment that can be drawn in the contour line of the sole 41 is assumed, the center line CL1 is a straight line that is orthogonal to the longest line segment at the center of the longest line segment. The virtual line Li is a straight line parallel to the longest line segment and in contact with the inside of the sole 41. The imaginary line Lo is a straight line that is parallel to the longest line segment and touches the outside of the sole 41. The distance between the virtual line Li and the virtual line Lo is the width W of the sole 41. A dashed-dotted line CL2 shown in FIG. 7 is a center line in the width direction. The center line CL2 is parallel to the virtual lines Li and Lo.
  Of the bottom surface, the area above the center line CL1 and the right side from the center line CL2 is a toe side from the center in the length direction and an outside area from the center in the width direction. A horizontal streak 45 is mainly formed in this region. Specifically, the ground contact area of the horizontal streak 45 occupying the ground contact area of all the streaks 45 and 47 included in this region is 50% or more, particularly 70% or more. This region is a region where a large load is applied when the player moves forward by kicking the ground and when sliding the tennis shoes while moving forward. By mainly forming the horizontal streak 45 in this region, both slide performance and anti-slip performance are achieved.
  Of the bottom surface, the area above the center line CL1 and the left side from the center line CL2 is a toe side from the center in the length direction and an inside area from the center in the width direction. A vertical streak 47 is mainly formed in this region. Specifically, the ground contact area of the vertical streak 47 occupying the ground contact area of all the streaks 45 and 47 included in this region is 50% or more, particularly 70% or more. This area is an area where a large load is applied when the player changes direction. By forming the vertical streak 47 mainly in this region, the slip prevention performance at the time of changing the direction is enhanced. The outside wall surface 53 mainly contributes to the improvement of the anti-slip performance. Due to the gentle inclination of the inside wall surface 51, the area of the ground contact surface 49 is small at the vertical streak 47. The contact pressure is increased by the contact surface 49 having a small area. A large contact pressure contributes to the improvement of anti-slip performance.
  The inclination angle θc formed by the inside wall surface 51 with respect to the horizontal plane is preferably 30 ° or greater and 70 ° or less. On the other hand, the inclination angle θd formed by the outside wall surface 53 with respect to the horizontal plane is preferably 50 ° or more and 90 ° or less. From the viewpoint of anti-slip performance, the difference (θd−θc) is preferably 10 ° or more, and more preferably 20 ° or more. The difference (θd−θc) is preferably 60 ° or less, and more preferably 50 ° or less.
  The height H of the vertical streak 47 is preferably 1 mm or more and 8 mm or less. The ratio (L4 / L3) of the distance L4 of the ground contact surface 49 to the distance L3 of the boundary portion between the base 43 and the vertical stripe 47 is preferably 0.2 or more and 0.8 or less.
  Also in this sole 41, from the viewpoint of achieving both sliding performance and anti-slip performance, the ratio (μa / μb) between the friction coefficient μa and the friction coefficient μb is preferably 0.9 or less, and more preferably 0.7 or less. If the ratio (μa / μb) is too small, unintentional slip in the toe direction tends to occur, so the ratio (μa / μb) is preferably 0.3 or more, and more preferably 0.5 or more.
  Also in the sole 41, the ratio of the total area of all the ground planes to the projected area of the bottom surface is preferably 15% or more and 70% or less. When the ratio is less than the above range, the ground contact surface is likely to be worn. From this viewpoint, the ratio is more preferably 25% or more. When the ratio exceeds the above range, the anti-slip performance may be insufficient. From this viewpoint, the ratio is more preferably 60% or less.
    FIG. 9 is a bottom view showing a sole 55 of a tennis shoe according to still another embodiment of the present invention. In FIG. 9, the upper side is the toe side, the lower side is the heel side, the right side is the outside, and the left side is the inside. A portion of the bottom surface above the center line CL1 is a toe portion. The left side of the center line CL2 is an inside portion. The sole 55 is for the left foot. The sole for the right foot has a shape obtained by inverting the shape shown in FIG.
  The sole 55 includes a base 57 and a muscle mountain 59. The streak 59 is formed integrally with the base 57 and protrudes from the base 57. The streak 59 includes a plurality of horizontal streaks 61 and vertical streaks 63. The horizontal stripe 61 extends in the width direction. The vertical streak 63 extends in the length direction. The horizontal stripes 61 are arranged in a plurality of rows in parallel in the length direction at a predetermined interval. The vertical streaks 63 are arranged in a similar row in the width direction.
  A plurality of horizontal stripes 61 are arranged on the outside of the toe portion. In the region which is the toe portion and the inside portion, the vertical streaks 63 are mainly arranged. Vertical stripes 61 are arranged in parallel below the longitudinal center line CL1. The streak 59 does not exist in the area corresponding to the arch.
  In the case of FIG. 9, the ground contact area of the sole 55 is the sum of the ground contact area of the horizontal stripe 61 and the contact area of the vertical stripe 63. In the toe portion, the ratio R1 (%) of the ground contact area of the horizontal streak 61 to the total ground contact area is expressed by the following mathematical formula (I).
  R1 = (Sxt / (Sxt + Syt)). 100 (I)
In this mathematical formula (I), Sxt represents the ground contact area of the horizontal streak 59 at the toe portion, and Syt represents the ground contact area of the vertical streak 59 at the toe portion. The streak 59 is formed so that the ratio R1 is 40% or more and 70% or less. The R1 is more preferably 45% or more and 65% or less, and particularly preferably 50% or more and 60% or less.
  In the inside portion, the ratio R2 (%) of the ground contact area of the vertical streak 63 occupying the total ground contact area is expressed by the following formula (II).
  R2 = (Syi / (Sxi + Syi)). 100 (II)
In this mathematical formula (II), Sxi represents the ground contact area of the horizontal streak 61 at the inside portion, and Syi represents the ground contact area of the vertical streak 63 at the inside portion. The streak 59 is formed such that the ratio R2 is 70% to 100%. There is a case where the slip performance and the anti-slip performance are good even when the inside portion does not have the horizontal streak 61 and is composed only of the vertical streak 63. The ratio R2 is more preferably 75% to 95%, and particularly preferably 80% to 90%.
  There are cases where the ground contact portion of the sole includes something other than the muscle mountain 59. For example, there may be an irregular array of protrusions, cylindrical protrusions, or a pattern such as a trade name. In these cases, the ratios R1 and R2 are calculated by excluding the portion not corresponding to the horizontal streak 61 and the vertical streak 63.
  When a tennis shoe having the sole 55 is used, tennis play is performed more smoothly. In actual tennis play, when starting to move forward, the ground is kicked at the toe. After that, the entire foot is grounded in the final stage of movement. Further, when moving in the lateral direction, the ground is kicked at the inside of the outer leg (for example, the left foot when moving in the right direction) at the start of movement.
  In other words, force is applied to the toe portion during forward movement, and force is applied to the inside portion during lateral movement. Furthermore, when stopping while slipping at the final stage of movement, the entire bottom surface acts. In the sole 55, a streak 59 is arranged in a direction perpendicular to the direction of the force at a portion where the force needs to be received. Thereby, the slip prevention performance is improved. In the sole 55, since the vertical streaks 63 are arranged at an appropriate ratio, the frictional resistance is reduced. Thereby, slip performance is improved.
  FIG. 10 is a perspective view from below showing a part of the sole 55 of FIG. In this figure, the base 57 and the transverse stripe 61 are shown. FIG. 11 is an enlarged cross-sectional view showing a part of FIG. As is apparent from FIGS. 10 and 11, the cross-sectional shape of the horizontal streak 61 is asymmetric. The horizontal stripe 61 includes a ground contact surface 67, a toe side wall surface 69, and a heel side wall surface 71. The ground contact surface 67 is a surface in contact with the ground when tennis shoes are worn. The toe side wall surface 69 is continuous with the ground contact surface 67 and is located closer to the toe side than the ground contact surface 67. The heel side wall surface 71 is continuous with the ground contact surface 67 and is located on the heel side with respect to the ground contact surface 67.
  In FIG. 11, the inclination angle θa of the toe side wall surface 69 is smaller than the inclination angle θb of the heel side wall surface 71. The sole 55 is suitable for use on artificial grass with sand. When the tennis shoe is placed on the artificial grass with sand and pulled toward the toe, the pulling force is mainly applied to the toe side wall surface 69. Since the inclination angle θa of the toe side wall surface 69 is small, the friction coefficient μa between the ground surface and the bottom surface is small. When the player slides the shoe, the sliding direction is the toe direction. Since this tennis shoe has a small friction coefficient μa, it has excellent sliding performance. A player wearing this tennis shoe can smoothly transition from movement to stroke. The slide also contributes to mitigating impact when landing.
  When the tennis shoe is placed on the artificial grass with sand and pulled in the heel direction, the pulling force is mainly applied to the heel side wall surface 71.傾斜 Since the inclination angle θb of the side wall surface 71 is large, the friction coefficient μb between the ground surface and the bottom surface is large. When a player moves forward by kicking the ground, the kick direction is the heel direction. Since this tennis shoe has a large friction coefficient μb, it is excellent in anti-slip performance when kicking.
  From the viewpoint of achieving both slide performance and anti-slip performance, the ratio (μa / μb) between the friction coefficient μa and the friction coefficient μb is preferably 0.9 or less, and more preferably 0.7 or less. If the ratio (μa / μb) is too small, unintentional slip in the toe direction tends to occur, so the ratio (μa / μb) is preferably 0.3 or more, and more preferably 0.5 or more.
  The height H of the horizontal streak 61 is preferably 1 mm or more and 8 mm or less. When the height H is less than the above range, the anti-slip performance may be insufficient. In this respect, the height H is more preferably 2 mm or more. If the height H exceeds the above range, the stiffness of the horizontal stripe 61 may be insufficient. In this respect, the height H is more preferably 6 mm or less.
  The ratio (L2 / L1) of the distance L2 of the ground contact surface 19 to the distance L1 of the boundary portion between the base 57 and the horizontal stripe 61 is preferably 0.2 or more and 0.8 or less. If the ratio (L2 / L1) is less than the above range, the stiffness of the horizontal stripe 61 may be insufficient. In this respect, the ratio (L2 / L1) is more preferably equal to or greater than 0.3. When the ratio (L2 / L1) exceeds the above range, the contact pressure may be insufficient and the anti-slip performance may be insufficient. In this respect, the ratio (L2 / L1) is particularly preferably equal to or less than 0.6.
  The deformation behavior of the muscle mountain 59 when the tennis shoe is used in the hard court is different from the deformation behavior of the muscle mountain 59 when the tennis shoe is used in the artificial grass court with sand. In the case of tennis shoes used in hard courts, the inclination angle θa of the toe side wall surface is preferably larger than the inclination angle θb of the heel side wall surface.
  FIG. 12 is an enlarged sectional view showing a part of the sole 55 of FIG. In this figure, the base 57 and the vertical streak 63 are shown. In FIG. 12, the left side is the inside and the right side is the outside. As apparent from FIG. 12, the vertical streak 63 includes a ground contact surface 73, an inside wall surface 75, and an outside wall surface 77. The inclination angle θc of the inside wall surface 75 is smaller than the inclination angle θd of the outside wall surface 77. The outside wall surface 77 contributes to the anti-slip performance when the direction is changed. Due to the gentle inclination of the inside wall surface 75, the area of the ground contact surface 73 is small in the vertical streak 63. The contact pressure is increased by the contact surface 73 having a small area. A large contact pressure contributes to the improvement of anti-slip performance.
  The inclination angle θc of the inside wall surface 75 is preferably 30 ° or greater and 70 ° or less. On the other hand, the inclination angle θd of the outside wall surface 77 is preferably 50 ° or more and 90 ° or less. From the viewpoint of anti-slip performance, the difference (θd−θc) is preferably 10 ° or more, and more preferably 20 ° or more. The difference (θd−θc) is preferably 60 ° or less, and more preferably 50 ° or less.
  The height H of the vertical streak 75 is preferably 1 mm or more and 8 mm or less. The ratio (L4 / L3) of the distance L4 of the ground contact surface 73 to the distance L3 of the boundary portion between the base 57 and the vertical streak 63 is preferably 0.2 or more and 0.8 or less.
  The ratio of the total area of all the ground planes to the projected area of the bottom surface is preferably 15% or more and 70% or less. When the ratio is less than the above range, the ground contact surface is likely to be worn. From this viewpoint, the ratio is more preferably 25% or more. If the ratio exceeds the above range, the contact pressure may be insufficient and the anti-slip performance may be insufficient. From this viewpoint, the ratio is more preferably 60% or less.
  FIG. 13 is a bottom view showing a part of a sole 79 according to still another embodiment of the present invention. The sole 79 also includes a muscle mountain 81. The streak 81 includes a truncated pyramid-shaped projection 83 and a truncated cone-shaped projection 85. As apparent from FIG. 13, in the present invention, when a plurality of protrusions continuously form a streak shape, the whole protrusion is referred to as one streak 81.
  FIG. 14 is a bottom view showing a sole 91 of a tennis shoe according to still another embodiment of the present invention. In FIG. 14, the upper side is the toe side, the lower side is the heel side, the right side is the outside, and the left side is the inside. The sole 91 is for the left foot. The sole for the right foot has a shape obtained by inverting the shape shown in FIG. The sole 91 includes a base 93, a plurality of horizontal stripes 95, and a plurality of vertical stripes 97. The horizontal stripe 95 and the vertical stripe 97 are formed integrally with the base 93 and protrude from the base 93. The horizontal streak 95 extends in the width direction. The vertical streak 97 extends in the length direction.
  FIG. 15 is an enlarged bottom view showing a part of the sole 91 of FIG. In this figure, a horizontal streak 95 is shown. The upper side in FIG. 7 is the toe side, and the lower side is the heel side. The horizontal streak 95 is formed by a projection 99 having a circular ground contact surface and a projection 99 having a ground contact surface having a dumbbell shape. Although not shown in FIG. 15, the vertical streak 97 is also formed by a series of protrusions having a circular ground contact surface and dumbbell protrusions having a ground contact surface (FIG. 14). reference). The horizontal streak 95 includes a wall surface 103 having a small inclination angle on the toe side and a wall surface 105 having a large inclination angle on the heel side. Although not shown in FIG. 15, the vertical streak 97 has a wall surface with a small inclination angle on the inside and a wall surface with a large inclination angle on the outside.
  In the sole 91, the ratio R1 is 40% or more and 70% or less, and the ratio R2 is 70% or more and 100% or less. In the sole 91, the friction coefficient μa in the toe direction is smaller than the friction μb in the heel direction. The ratio of μa to μb (μa / μb) is 0.3 or more and 0.9 or less. The tennis shoe provided with the sole 91 is excellent in both slip prevention performance and slide performance.
  In the sole 91, an arc-shaped protrusion 107 is formed at a point where the horizontal stripe 95 and the vertical stripe 97 intersect. Due to the arc-shaped protrusion 107, the horizontal stripe 95 and the vertical stripe 97 continue smoothly. The sole 91 is less likely to be chipped.

    [Experiment 1]

A rubber composition based on a styrene-butadiene copolymer was put into a mold, and a crosslinking reaction was caused to the rubber to obtain a sole. The bottom surface pattern of this sole is shown in FIG. A large number of transverse muscle mountains are formed on the sole. The inclination angle θa of the horizontal streak is 30 °, the inclination angle θb is 90 °, the height H is 3 mm, and (L2 / L1) is 0.25. A midsole made of an ethylene vinyl acetate copolymer and an upper made of cotton were attached to the sole to obtain a tennis shoe of Example 1.
[Examples 2 to 3 and Comparative Examples 1 to 2]
Tennis shoes of Examples 2 to 3 and Comparative Examples 1 to 2 were obtained in the same manner as in Example 1 except that the mold was changed to form a sole having a horizontal streak of the shape shown in Table 2 below. It was.

［実験２］A tennis shoe of Example 4 was obtained in the same manner as in Example 1 except that the molding die was changed to form a sole having a horizontal streak and a vertical streak having the shapes shown in Table 1 below. This sole pattern is shown in FIG.
[Practical test]
The player wore tennis shoes and played a tennis rally on an artificial grass court with sand (trade name “Omni Court” from Sumitomo Rubber Industries). The ease of direction change, anti-slip performance at the start, slide performance, and leg fatigue were evaluated in five stages from “1” to “5”. The highest evaluation was given as “5”. The average rating of 10 players is shown in Table 1 below. As shown in Table 1, the outsole of the example has good evaluation results in all items.

[Experiment 2]

A rubber composition based on a styrene-butadiene copolymer was put into a mold, and the rubber composition was vulcanized to obtain a sole. The bottom surface pattern of this sole is shown in FIG. A plurality of transverse muscles and longitudinal muscles are formed on the sole. The ground contact area ratio R1 of the horizontal stripes to the total contact area of the stripes at the toe part is 50%, and the contact area ratio R2 of the vertical stripes to the total contact area of the stripes at the inside part is 90%. A tennis shoe of Example 5 was obtained by attaching a midsole made of an ethylene vinyl acetate copolymer and an upper made of cotton to the sole.
[Example 6 and Comparative Examples 4 to 5]
Tennis shoes of Example 6 and Comparative Examples 4 to 5 were obtained in the same manner as Example 5 except that the molding die was changed and a sole having the specifications shown in Table 2 below was molded.
[Comparative Example 3]
A commercial name “CT592” sold by New Balance Japan Co., Ltd., which is a commercial product, was prepared and used as Comparative Example 3.
[Practical test]
A player wears tennis shoes and played a tennis rally on a sandy artificial turf court (trade name “Omni Court” by Sumitomo Rubber Industries). Then, the anti-slip performance at the time of forward movement, the anti-slip performance at the time of lateral movement and the comfort were evaluated in five stages from “1” to “5”. The highest evaluation was given as “5”. The average rating of the 10 players is shown in Table 2 below. As shown in Table 2, the outsole of the example has good evaluation results in all items.

  The tennis shoe according to the present invention is suitable for playing on various courts. This tennis shoe is more suitable for a coat having a small friction coefficient (sand-containing artificial turf coat and clay coat). This tennis shoe is particularly suitable for an artificial turf court with sand. This tennis shoe can contribute to improving the player's performance.

Claims (9)

The bottom surface has a horizontal streak extending in the width direction and having a toe side wall surface and a heel side wall surface, and a vertical streak mountain extending in the length direction and having an inside wall surface and an outside wall surface,
The inclination angle θa of the toe side wall surface is smaller than the inclination angle θb of the heel side wall surface,
A tennis shoe in which the inclination angle θc of the inside wall surface is smaller than the inclination angle θd of the outside wall surface . 2. The tennis shoe according to claim 1, wherein a ratio (μa / μb) of a friction coefficient μa in the toe direction of the bottom surface to a friction coefficient μb in the heel direction is 0.3 or more and 0.9 or less. Upper Ki傾 oblique angle .theta.a and inclined oblique angle .theta.b tennis shoe according to claim 1 or 2 difference (θb-θa) is 60 ° or less 10 ° or more. 4. The tennis shoe according to claim 1, wherein a difference (θc−θd) between the inclination angle θc and the inclination angle θd is 10 ° or more and 60 ° or less . 5. The tennis shoe according to any one of claims 1 to 4, wherein a height of the horizontal and vertical muscles is 1 mm or more and 8 mm or less. Of the above bottom surface, the side of the toe side is longer than the center in the length direction and the outer region is more than the center in the width direction. The tennis shoe according to any one of claims 1 to 5, wherein a vertical streak is mainly formed in a region inside the center in the width direction. And 70% or less the ratio R1 of 40% or more of the ground contacting area of the whole ground area occupied lateral stripes mountain in the toe side than the longitudinal centerline of the bottom surface, all in the inside than the widthwise center line of the bottom surface The tennis shoe according to any one of claims 1 to 6, wherein a ratio R2 of a contact area of the vertical streak occupying the contact area is 70% or more and 100% or less. The tennis shoe according to claim 7 , wherein the ratio R1 is not less than 45% and not more than 65%, and the ratio R2 is not less than 75% and not more than 95%. The tennis shoe according to claim 8 , wherein the ratio R1 is not less than 50% and not more than 60%, and the ratio R2 is not less than 80% and not more than 90%.

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