JPH09680A - Track-boundary stones in athletic sports field - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable changing over, by simple operation, between the state where boundary stone bodies are pushed out above the ground surface and the state where they are stored into the ditch. SOLUTION: Boundary stone bodies 3 are arranged along a ditch 2 which forms a border between both track and field. Whenever the supporting base 7, fixed in the ditch, receives pressuring force in the axial direction, changing over is made between both its first shortened state and second lengthened state. Then, the boundary stone bodies are supported to be movable up and down by longitudinally fitting a latch unit which maintains the present state until receiving the next pressuring force. The stroke of the latch unit is set so that the upper surface of the boundary stone bodies may be below the ground surface level and stick out to the specified height above the ground surface for the first state and the second state, respectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inner sphere curb laid at the boundary between a track and a field on an athletic field, and particularly to a state where the curb body is projected from inside the groove on the ground surface and is lowered as it is It is designed to be converted into the state of being stored inside.

[0002]

2. Description of the Related Art Curbstones in the inner sphere of conventional track and field are
As described in JP-A-5-79012,
Plural legs are hung vertically at a predetermined interval in the lower part of the curb body, and a groove is formed at the boundary between the track and the field, and a short tubular receiving portion is embedded in the groove. When performing a track competition, the legs are fitted in the receiving part to support the curb body in a state of protruding at a predetermined height from the ground surface,
When performing a field competition, pull out the leg from the receiving part and then shift the curb body in the longitudinal direction, that is, change the position so that the leg does not hit the receiving part and drop the curb body into the groove for storage. However, this made sure that there was no protrusion at the boundary between the track and the field.

[0003]

However, in a general athletic field, the circumference of the track is 400 meters, and the leg portion of the curb body for one circumference of the track is inserted into the tubular receiving portion in the groove, or It takes a lot of time and labor to complete the work of extracting. In addition, this work is more labor than expected because you have to sit down. Therefore, even though the curbstone main body is attached and detached by a simple operation of inserting and removing the legs, it cannot always be said that the operation is easy because of the lack of manpower.

Further, since it takes a long time to attach and detach the curb, the competition schedule has also been limited due to the switching time.

Furthermore, if the curb body is moved in the longitudinal direction and then dropped into the groove, the straight curb body does not enter the arc groove at the connecting portion of the straight line and the corner, and Since the curb body does not enter the straight groove, it is configured so that a part of the curb can be separated at this connecting part, and when the curb is projected from the ground surface, a part of the curb is connected, and when the curb is stored in the groove, The part had to be removed and stored in a warehouse or the like, which was troublesome to handle.

Therefore, according to the present invention, it is possible to convert the curb body into a state in which it projects from the ground surface and a state in which it does not project by a simple operation, and it is possible to greatly reduce the labor and time required for the operator. The purpose is to provide an inner curb for an athletics stadium.

[0007]

DISCLOSURE OF THE INVENTION The present invention has been proposed in order to achieve the above-mentioned object. According to a first aspect of the present invention, the upper surface is open at the boundary between a track and a field of an athletic field. , Forming a groove in which the curb body can be housed, arranging the curb body along the groove, fixing a support base inside the groove, and extending to the support base in the axially shortened first state It can be converted into a second state, and when the upper portion is pulled up in the first state, the extended second state is held, and once the upper portion is pulled up in the second state, the second state is released and the first state is released. The latch unit for holding the first state is provided in the vertical direction, and the curb body is supported by the latch unit so as to be movable up and down. In the first state of the latch unit, the upper surface of the curb body is below the ground surface, In the 2 state, the upper surface of the curb body is above the ground surface Is inner-sphere curb the athletic field, characterized in that setting the stroke of the latch unit so as to protrude to a predetermined height.

According to a second aspect of the present invention, at the boundary between the track and field of the athletic field, a groove having an open upper surface and capable of accommodating the curb body is formed, and the curb body is arranged along the groove. , A supporting base is fixed inside the groove, and each time the supporting base receives a pressing force in the axial direction, the supporting base is converted into a shortened first state and an extended second state, and the next pressing force is changed. A latch unit that holds the state until receiving is provided in the vertical direction, and the curb body is supported by the latch unit so as to be vertically movable. In the first state of the latch unit, the upper surface of the curb body is below the ground surface, and the second state In the inner sphere curb on an athletic stadium, the stroke of the latch unit is set so that the upper surface of the curb body is projected to a predetermined height above the ground surface.

In the second aspect, when the latch unit is shortened to the first state, the curb body is housed in the groove formed at the boundary between the track and the field and does not project to the ground surface. Therefore, there are no obstacles at the boundary between the field and the track, and the curb body does not get in the way even when playing a field competition.

When the curb body is pushed downward with the curb body stored in the groove, the latch unit supporting the curb body extends, so that the curb body rises and protrudes from the ground surface to a predetermined position. Convert to a second state that stops at the height of. Then, even if the pressing force is released in a state where the curbstone main body is projected to a predetermined height, the latch unit maintains the second state. Therefore, the boundary between the track and the field can be sectioned by the curb body according to the standard, and the track competition that meets the regulations can be performed.

When the curb body is pushed downward in the second state in which the curb body projects, the curb body is lowered to be housed in the groove and the latch unit is reduced. Then, when the upper surface of the curb body is sufficiently pushed down to the level below the ground surface, the latch unit maintains the shortened first state, so that the curb body descends and maintains the state stored in the groove.

According to a third aspect of the present invention, in addition to the structure of the first or second aspect, a height adjusting mechanism for adjusting the height of the latch unit with respect to the support base is provided. It is an inner curb.

In the third aspect, when the height adjusting mechanism is adjusted, the height of the latch unit with respect to the support base changes. Therefore, even if the stroke of the latch unit is a fixed length, by adjusting the height of the latch unit with respect to the support base, the curb body is below the ground surface in the first state, and the upper surface of the curb body is in the second state. It can be installed at a certain height above the ground surface.

According to a fourth aspect, the first to third aspects are provided.
In addition to any one of the above configurations, a first state in which the curbstone body is stopped at a position lower than the ground surface, and a second state in which the curbstone body is located below the end portion of the curbstone body that has protruded from the ground surface and is raised An inner sphere curb in an athletic field, characterized in that a descent prevention stopper having a stopper body that can be converted into a state is provided in the groove.

In the fourth aspect, when the stopper body is brought into the first state, the stopper body stops at a position lower than the ground surface, so that the curb body can be stored in the groove.
Therefore, there is nothing that protrudes from the ground surface, and the field competition can be performed. Then, when the curbstone body is converted into a state in which it projects from the ground surface and the stopper body is converted into a second state, the stopper body projects from the ground surface and is located below the end portion of the curbstone body. Therefore, even if a downward force is applied to the curb body, the stopper body prevents the curb body from descending.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. Inner sphere curb on athletics stadium 1
Form a groove 2 at the boundary between the track and the field and are arranged along the groove 2. The groove 2 has an open upper surface and has a width and a depth that can accommodate the curbstone body 3. In order to form the groove 2, in the present embodiment, the concrete blocks 4 for drainage having an opening on the upper surface are accurately connected and buried at the predetermined positions of the boundaries, and these blocks 4 ...
It is constructed by fixing a pair of long L-shaped members 5 serving as groove wall surfaces at predetermined intervals (width of the groove 2) along the both opening edges of the upper surface opening portion with bolts 6. Then, in a predetermined depth portion in the groove 2, a downward U-shaped iron plate in which both sides of the horizontal portion are bent downward is fitted as a support base 7 between both groove wall surfaces and fixed by a bolt. It should be noted that a plurality of the support bases 7 are installed at predetermined intervals corresponding to the legs that support the curb body 3. In the figure, 9 is a mortar and 10 is a urethane layer.

The curb body 3 is made of a long metal material such as aluminum or stainless steel. In the embodiment shown in the drawings, a hollow extruded material having a substantially rectangular cross section has a predetermined length, for example, 4 mm.
It is cut into meters. Then, a plurality of two kinds of leg portions, a guide leg portion 12 and a support leg portion 13, are vertically erected from a bracket 11 provided on the lower surface of the curbstone body 3 at predetermined intervals, and the support leg portion 13 is connected to the support base 7 The curb body 3 is supported so as to be movable up and down, and the guide legs 12 are inserted into the guide tube portion 14 of the support base 7 so that the curb body 3 moves up and down in a horizontal state.

In this embodiment, one curbstone body 3 is used.
Is provided with two support leg portions 13 and two guide leg portions 12, a total of four leg portions, and the guide leg portions 12 are arranged on the end side of the curb,
A support leg 13 is arranged between the two guide legs 12.

The guide leg 12 is a columnar body, and its upper end is fixed to the lower surface of the curb body 3 via a bracket 11. The lower half portion of the guide leg portion 12 is the guide tube portion 1
Since it moves up and down in 4, it is desirable that it be smooth.

A guide tube portion 1 for guiding the guide leg portion 12
Reference numeral 4 denotes a cylindrical body fixed to the support base 7 with bolts, and has a bearing (not shown) built therein so that the guide leg can be smoothly moved up and down. Further, the bracket 11 has a long mounting hole so that the fixing position can be finely adjusted. Therefore, when the lower half portion of the guide leg portion 12 is inserted into the guide cylinder portion 14, the curb body 3 can be vertically moved at a predetermined position while being maintained in a horizontal state by the guide of the guide cylinder portion 14. .

On the other hand, each time the supporting leg portion 13 receives a pressing force in the axial direction, the supporting leg portion 13 is converted into a shortened first state and an expanded second state, and the state is maintained until the next pressing force is received. The latch unit 15 is provided on the support base 7 in the vertical direction. The latch unit 15 supports the curbstone body 3 so that it can move up and down.
2, the upper surface of the curb body 3 is below the ground surface in the first state of the latch unit 15, and as shown in FIG.
In the second state, the stroke of the latch unit 15 is set so that the upper surface of the curbstone body 3 projects above the ground surface to a predetermined height. Further, the support leg portion 13 includes a height adjusting mechanism that adjusts the height of the latch unit 15 with respect to the support base 7.

The height adjusting mechanism in this embodiment is shown in FIG.
As shown in FIG. 3, the mounting flange 18 at the lower end of the cylindrical body 17 is fixed with bolts 19 on the support base 7 in a state where the cylindrical body 17 having the female screw portion formed on the inner peripheral surface is oriented in the vertical direction. The male screw portion 20 formed on the outer peripheral surface of the latch unit 15 is screwed into the female screw portion 17 of the latch unit 15, and the screwing position of the female screw portion and the male screw portion 20 is adjusted, whereby the support base 7 of the latch unit 15 is adjusted. It is configured so that the height for the can be adjusted. In addition, the outer peripheral surface of the latch unit 15 has a vertical locking groove 21.
A rotation stopper 23 having a convex portion 22 that engages in the locking groove 21 is erected from the outer peripheral surface of the cylindrical body 17, and the spring of the rotation stopper 23 or the convex portion 22 is provided. Thereby biasing the tip of the convex portion toward the outer peripheral surface of the latch unit 15. It is desirable that a plurality of locking grooves 21 formed on the outer peripheral surface of the latch unit 15 are formed with different phases. In this embodiment, a total of four locking grooves 21 are formed at 90-degree intervals. Therefore, the latch unit 15 can be locked at a desired angle of 90 degrees.

Therefore, the tip of the convex portion 22 has the engaging groove 21.
When the latch unit 15 is rotated against the engaging force to be engaged therein, the tip of the convex portion 22 is disengaged from the locking groove 21 and the latch unit 15 can be rotated by a desired rotation angle. The screwing position of the female screw portion and the male screw portion changes, and the latch unit 15 can be adjusted to a desired height. Then, when stopping the rotation of the latch unit 15 and stopping at the position where the tip of the convex portion 22 engages with the locking groove 21, the rotation of the latch unit 15 is changed to the convex portion 22.
Is blocked (locked) by the engaging force with which the tip of the engaging member engages in the locking groove 21. Therefore, once the latch unit 15
If the height of the latch unit 15 is set, the latch unit 15 can maintain the height. Therefore, at the time of construction or verification, if the latch unit 15 is adjusted by rotating until the height from the ground surface (track surface) to the upper surface of the curb body 3 is regulated, after that, The protruding height of the curbstone body 3 from the ground surface can be maintained at a predetermined height.

Next, the latch unit 15 operated by the push operation will be described. Each time the latch unit 15 receives a pressing force in the axial direction, the latch unit 15 has a function of converting the contracted first state to the expanded second state and holding the state until the next pressing force is received. In the first state, the upper surface of the curb body 3 is below the ground surface, and in the second state, any structure may be used as long as the stroke is set such that the upper surface of the curb body 3 projects to a predetermined height above the ground surface.

The first embodiment of the latch unit 15 shown in FIGS. 5 to 7 is a bottomed cylindrical outer cylinder having a male screw portion formed on the outer peripheral surface and a guide groove 25 formed on the inner peripheral surface in the axial direction. The member 26, the inner member 27 that is movably fitted inside the outer tubular member 26, the spring 28 that urges the inner member 27 in a direction to push the inner member 27 to the outside of the outer tubular member 26, and the inner member 27 are formed. It has a leaf spring 29 with an engaging portion as an elastic engaging member that cooperates with the cam to perform the movement of the push latch mechanism.

The inner member 27 is the outer cylinder member 26 shown in FIG.
A male screw portion 31 that is inserted into the mounting hole of the bracket 11 and tightens the nut is formed at the tip of the cylindrical head portion 30 protruding from the coil, and the coil is formed on one surface of the partition wall 32 extending downward from the head portion 30. A substantially cylindrical spring accommodating space 33 for accommodating the spring 28 is formed, and as shown in FIGS. 5 and 6, a substantially wedge-shaped guide cam 34 and a tip 34a are formed in the middle of the other surface of the partition wall 32. The direction regulating cam 36 having an inverted triangle shape is formed diagonally downward and above the small substantially V-shaped locking recess 35 formed on the top of the guide cam 34.
Formed below the guide cam 34 are top dead center cams 37 that extend laterally from below the pointed end 34a of the guide cam 34 and have the tip inclined obliquely upward.

The locking recess 35 of the guide cam 34 is a part for locking the stopping position of the inner member 27 in the first state by locking with the locking part 40 of the leaf spring 29.
The guide cam 34 among the upper ends on both sides extending obliquely upward from
The upper end on the side of the pointed tip 34a is set slightly higher than the other upper end. The top dead center cam 37 is a portion that locks with the locking portion 40 of the leaf spring 29 to regulate the stop position of the inner member 27 in the second state, and the locking recess 35 and the top dead center cam 37.
Since the distance (vertical length) from the upper surface is the stroke of the inner member 27, in this distance, the upper surface of the curb body 3 is below the ground surface in the first state of the latch unit 15, and the distance of the curb body 3 in the second state. Set the length so that the upper surface projects above the ground surface to a predetermined height.

Further, the guide pieces 3 are provided on both side edges of the partition wall 32.
9 is formed, and the guide piece is fitted into the guide groove 25 formed on the inner peripheral surface of the outer tubular member 26, thereby preventing the inner member 27 from rotating with respect to the outer tubular member 26.

As shown in FIG. 7 (c), the leaf spring 29 with an engaging portion has a longitudinally extending leaf spring portion 41 having an engaging portion 40 projecting laterally at the upper end thereof and a hook-like attachment at the lower end thereof. It is an elastic plate material in which the portion 42 is formed. The leaf spring 29 with the locking portion is
In order to bias the locking portion 40 at the upper end to one side, it is bent in a slight V shape from the vicinity of the mounting portion 42 at the lower end. Then, in order to attach the leaf spring 29 with the engaging portion to the outer cylinder member 26, the insertion hole 4 opened near the one side of the bottom surface of the outer cylinder member 26.
Insert the locking portion 40 from 3, and hook the hook-shaped mounting portion 42 at the lower end on the bottom surface. When attached in this manner, the leaf spring portion 41 on the way extends along the partition wall 32 of the inner member 27,
In the natural state, the locking portion 40 at the upper end is the partition wall 3 of the inner member 27.
It is located in the approximate center of 2 and can be locked to each cam. The elastic locking member is not limited to the leaf spring 29 with the locking portion, and the locking portion 40 that can be locked to each cam and the locking portion 40.
It suffices to have an elastic portion for urging the rod in a predetermined direction. For example, an elastic rod member having one end bent as the locking portion 40 and the mounting portion 42 formed at the other end may be used.

The latch unit 15 having the above structure
In the first state in which the overall length (height) has been shortened, as shown in FIG. 5, the locking portion 40 of the leaf spring 29 with the locking portion is guided by the guide cam 3.
It is locked in the locking recess 35 of No. 4 to prevent the inner member 27 from projecting due to the biasing force of the coil spring 28. Therefore, the inner member 27 stops in a state of being housed in the outer cylinder member 26, and the latch unit 15 has the entire length (height).
Maintains the shortened first state. Then, in this first state, the height of the latch unit 15 is adjusted so that the upper surface of the curb body 3 fixed to the upper end of the inner member 27 is located below the ground surface (track surface).

Therefore, in this first state, the curb body 3 does not get in the way even if a field competition or the like is performed. In addition, the upper surface of the curb body 3 may be below the ground surface, but it stops at a low position (for example, 2 to 3 mm) from the ground surface so that a person is not stepped on the curb body 3 by mistake. It is desirable to adjust so that

In this first state, when a force is applied from above to push down the curb body 3 against the biasing force of the coil spring 28, the inner member 27 is slightly lowered and the locking portion of the leaf spring 29 with the locking portion. 40 is disengaged from the locking recess 35, and the elasticity of the leaf spring 41 causes the locking part 40 to move slightly to the tip 34a side (right side in FIG. 5) of the guide cam 34, and also descends to the direction regulating cam 36. One of the inclined surfaces (on the side of the tip 34a of the guide cam 34) comes into contact with the upper end of the locking portion 40 to reliably move the side of the tip 34a of the guide cam 34.

When the locking portion 40 is disengaged from the locking recess 35 of the guide cam 34 in this manner, the locking portion 40 is moved by the elasticity of the plate spring portion 41 and by the guide of the direction regulating cam 36.
Is located above the upper inclined surface 34b between the upper end of the guide cam 34 and the point 34a. In this state, when the pressing force on the curb body 3 is released and the inner member 27 is lifted by the urging force of the coil spring 28, the guide cam 34
As the engaging portion 40 contacts the upper inclined surface 34b of the guide cam 34 and the guide cam 34 further rises, the engaging portion 40 is guided by the upper inclined surface 34b (the upper inclined surface 34b).
It slides down on b) and relatively descends to the tip 34a of the guide cam 34. At the position where the locking portion 40 comes into contact with the vicinity of the tip 34a of the guide cam 34, the stop position (almost the center of the width of the partition wall 32) of the locking portion 40 in the natural state of the leaf spring portion 41 is moved to the tip 34a side. Therefore, due to the elasticity of the plate spring portion 41, the locking portion 40 exerts a force to return to the side opposite to the tip 34a.

When the inner member 27 further rises in this state, the locking portion 40 is disengaged from the pointed end 34a of the guide cam 34 and is returned and moved by the elasticity of the leaf spring portion 41. During this time, the inner member 27 also rises due to the biasing force of the coil spring 28, so that the upper surface of the top dead center cam 37, which has also risen, is caught by the lower end edge of the locking portion 40, whereby the inner member 27 is raised. Stop (Fig. 6). Therefore, the extension operation of the latch unit 15 is stopped by this, and the extended second
The second state is maintained while being converted into the state. Then, when the latch unit 15 is converted to the second state, the curb body 3 also stops rising, and the state in which the upper surface of the curb body 3 projects from the ground surface (track surface) to a predetermined height is maintained.

Therefore, in the inner sphere curb 1 according to the present invention, the curb main body 3 stored in the groove 2 without protruding from the ground surface is pushed down only once, and the curb main body 3 is inserted into the latch unit 15. By the urging force of the coil spring 28, the coil spring 28 rises to a predetermined height and then stops, so that the track competition can be performed in this state. The protruding height of the curbstone body 3 is set to a predetermined height by the height adjusting mechanism as described above.

Next, a case where the protruding curb body 3 is housed in the groove 2 will be described. When the curbstone body 3 is pushed down, the inner member 27 descends, so that the leaf spring 2 with the engaging portion
When the engaging portion 40 of 9 separates from the top dead center cam 37 and the inner member 27 further descends, the guide cam 34 that has descended together
When the lower inclined surface 34c contacts the upper edge of the locking portion 40 and the inner member 27 further descends, the locking portion 40 is guided by the lower inclined surface 34c and moves to the left side in FIG. Rise relatively along 34c. And the inner member 27
Is further lowered and the lower end edge of the locking portion 40 passes through the lower upper end (upper left end in the figure) of the locking recess 35 formed in the guide cam 34, the elastic force of the leaf spring portion 41 causes the engagement. The stopper 40 moves to the valley side of the locking recess 35 and locks in this valley (the deepest part of the locking recess 35). By the engagement of the engagement portion 40 with the engagement recess portion 35, the rise of the inner member 27 is stopped, whereby the latch unit 15 returns to the contracted first state and maintains this first state (FIG. 5).

In the above embodiment, the outer cylinder member 26
Was attached to the support base 7 and the vertically movable inner member 27 fitted in the outer cylinder member 26 was connected to the curb body 3 via the bracket 11, but the latch unit 15 may be attached in the opposite direction. That is, the inner member 27 may be attached to the support base 7 side, and the outer cylinder member 26 may be attached to the curb body 3 side. If this is done, sand, dust, etc.
5 can be prevented from invading, and failure or trouble can be prevented in advance.

The latch unit 15 according to the present invention is attached to the support base 7 to support the curb body 3 so that the curb body 3 can be moved up and down, and the latch unit 15 is shortened each time a pressing force is applied in the axial direction.
The state can be converted into the extended state and the extended second state, and the state can be maintained until the next pressing force is applied. In the first state, the upper surface of the curbstone body 3 is below the ground surface, and in the second state, the curbstone body. Any configuration may be used as long as a stroke is set so that the upper surface of 3 projects above the ground surface to a predetermined height.
For example, the latch unit 15 having a rotary cam and a groove through which the rotary cam passes and having the above-mentioned function may be used.

In the second embodiment of the latch unit 15 'shown in FIG. 8, a slider 46 as an inner member provided with a rotating cam 45, a slider 46 is housed, and a guide for the rotating cam 45 to pass through the inner surface is provided. A casing 48 corresponding to an outer cylinder member having a groove 47 formed therein and a coil spring 28 for urging the slider 46. The casing 48 is attached to the support base 7 side, and the upper end of the slider 46 is attached via the bracket 11 to the curb body. 3 to support the curb body 3 so as to be vertically movable. The guide groove 47 is formed on the inner surface of the lid member 49 that closes the side surface of the casing 48. Further, similarly to the first embodiment, the casing 48
A male screw is formed on the outer peripheral surface of the latch unit 15 '.
The height of the above with respect to the support base 7 may be adjustable.

The rotary cam 45 has a slider 4 in the central hole.
It is a substantially rectangular parallelepiped cam that is mounted in a freely rotatable state by loosely fitting a shaft 51 projecting from 6 and has recesses formed on both short sides.

The guide groove 47 for guiding the rotary cam 45 in a fitted state is formed in a long shape along the sliding direction of the slider 46, and the width is such that the rotary cam 45 can move in a vertical posture. The size is set so that it cannot move in the horizontal posture. Further, at the upper end of the guide groove 47, the rotary cam 4
A convex portion 52 that fits into the depression of No. 5 is formed, and a wide portion 53 in which one upper side near the lower end is inclined is formed.

When the rotary cam 45 is oriented in the vertical direction, the rotary cam 45 can freely move up in the guide groove 47, so that the slider 46 moves up by the urging force of the coil spring 28, and the rotary cam 45 moves. Guide groove 47 at the top
Abut the upper end of. Therefore, as shown in FIG. 8A, the slider 46 projects the longest and the latch unit 1
The full length (height) of 5'is in the second state in which it is extended most.

In this second state, when the curb body 3 is pushed down against the biasing force of the coil spring 28, the slider 46
And the rotating cam 45 also descends. Then, when the rotating cam 45 is sufficiently lowered, as shown in FIG. 8B, one lower end corner portion of the rotating cam 45 has a lower end of the wide portion 53 slightly protruding toward the center of the guide groove 47. Edge 53
Since it is caught by a, the rotary cam 45 rotates about the shaft 51 and becomes oblique and stops.

When the pressing force is released in this state, the slider 46 is slightly raised by the biasing force of the coil spring 28, and the rotary cam 45 is also raised while being inclined. When the rotating cam 45 rises diagonally, as shown in FIG. 8C, the rotating cam 45 is caught at the upper end portion of the wide portion 53, and further rise is prevented. Therefore, the slider 46 stops in the lowered state, and the latch unit 15 'converts into the expanded / contracted first state and maintains this first state.

When the curb body 3 is pressed downward again in this first state, the slider 46 descends a little, and the rotary cam 45 descends while being slanted so that the slanted lower end side is the lower end edge of the wide portion 53 first. 53a is contacted. Rotating cam 4
When 5 further descends, the portion that abuts the lower end of the wide portion 53 cannot descend, so that the rotating cam 45 slightly rotates to horizontally or descend the opposite end as shown in FIG. 8D. It becomes a posture. That is, when the rotary cam 45 hooked on the upper end of the wide portion 53 descends, the rotary cam 45 rotates when it comes into contact with the lower end 53a of the wide portion 53 and becomes horizontal or reversely inclined. Then, in this state, both ends of the rotary cam 45 contact the lower ends of the wide portions 53, so that the slider 4
6 is prevented from descending.

When the downward pressing force applied to the curb body 3 is released at the lowermost position of the slider 46, the slider 46 ascends due to the urging force of the coil spring 28 and the rotary cam 45 ascends in a horizontal or inclined posture. . Then, when the rotating cam 45 rises to the upper end of the wide portion 53, one end of the rotating cam 45 (the end on the inclined lower end side or the side corresponding thereto) is moved to the upper end of the wide portion 53 as shown in FIG. However, the other end of the rotary cam 45 does not come into contact with the other end due to the existence of the inclined clearance portion of the wide portion 53. Therefore, when the slider 46 further rises, the rotary cam 45 rotates in a direction in which the abutting end is left (delayed) and the non-abutting end is raised, whereby the rotary cam 45 moves in a substantially vertical direction. Change posture. Therefore, when the slider 46 further rises, the rotating cam 45
Can rise in the guide groove 47 in a vertical posture,
The rotary cam 45 rises until it comes into contact with the upper end of the guide groove 47. When the rotary cam 45 contacts the upper end of the guide groove 47, the slider 46 stops rising and returns to the second state.
Stay in the state.

In each of the above embodiments, the curb body 3
The track competition is performed in the second state in which the ridge is projected from the ground surface, but in this state, there is a possibility that the athlete or the like may accidentally step on the curbstone body 3 to lower it.

Therefore, the first state stopped at a position lower than the ground surface, and the curb body 3 protruding and rising from the ground surface
Located below the end of the curb to prevent the curb body 3 from descending
A descent prevention stopper 62 having a stopper body 61 that can be converted into a state is provided in the groove 2, and the stopper body 61 is interposed between the projected curb body 3 and the ground surface GL when a track competition is performed. Thus, the curb body 3 may be configured to be prevented from being accidentally lowered.

For example, the descent prevention stopper 62 shown in FIGS. 9 and 10 is disposed below the position where the ends of the adjacent curbstone bodies 3 and 3 abut each other, and forms the groove wall surface of the groove 2. A stay 64 having a substantially U-shaped cross section, which has upright portions 63, 63 on both sides, is installed between 5 and 5, and the stay 64 is
The stopper body 61 is attached to the support shaft 6 between the upright portions 63, 63.
5, a state maintaining member 66 of the stopper body 61 is provided while being pivotally attached at a predetermined height. The stopper body 61 is composed of a prismatic body, and has the support shaft 6 in a through hole formed near one end (lower end).
It is rotatably supported by penetrating 5 and the other end (upper end) opposite to the through hole functions as a stopper receiving portion 67. Then, the state maintaining member 66 that maintains the posture of the stopper body 61, in other words, maintains the state.
Is composed of a stopper pin attached laterally from one upright portion 63 to the other upright portion 63, and is positioned below the support shaft 65 and parallel to the support shaft 65.

The stopper body 61 may be a solid metal column or a hollow pipe. In the case of using a hollow pipe, it is desirable to close the upper end that functions as the stopper receiving portion 67.

Fall prevention stopper 6 having the above-mentioned structure
As shown by the alternate long and short dash line in FIG. 9, when the stopper body 61 is tilted in the extending direction of the groove 2 and laid down, the stopper receiving portion 67 is provided.
Stops at a position lower than the ground surface and enters the first state. Then, in this first state, the stopper body 61 is supported by the pin which is the state maintaining member 66 to maintain the lying state. Further, the stopper main body 61 is provided at a height that does not interfere with the curbstone main body 3 even if the curbstone main body 3 descends and is housed in the groove 2. Therefore, the stopper body 61
When the curb body 3 is pressed downward in the first state in which the
The curb body 3 is housed in the groove 2 without interfering with the lowering prevention stopper 62.

Even if the curb body 3 is housed in the groove 2, the dimensions and mounting positions of the respective members are set so that a gap D1 is formed between the curb body 3 and the stopper body 61. I am doing it. Therefore, the gap D1 serves as a pressing margin necessary for changing the state of the latch unit 15.

When playing a track competition, first, the upper surface of the curb body 3 is once pressed downward. When the curbstone main body 3 housed in the groove 2 is pressed, as described above, the latch unit 15 extends and the curbstone main body 3 rises to a predetermined height, and protrudes from the ground surface and stops.

Next, the stopper body 61 is rotated to stand up. In this case, for example, if a rod-shaped tool having a hook at the tip is inserted into the groove and the stopper body 61 is rotated, the worker can easily perform the work without sitting down. As shown in FIG. 10, if a large gap is formed on one side of the stopper body 61 by providing the stopper body 61 close to one side, it is easy to insert a rod-shaped tool.

When the stopper body 61 is rotated to stand up, as shown by the solid line in FIGS. 9 and 10, the stopper receiving portion 67 protrudes from the ground surface, and the end portions of the left and right curbstone bodies 3, 3 are joined to each other. Is converted to a second state in which it stops below the position where the two abut. Then, when the stopper body 61 is converted to the second state, the lower side surface of the stopper body 61 is moved to the state maintaining member 6
6 and the center of gravity of the stopper body 61 is
Since it is located on the opposite side of the state maintaining member 66 from above, the stopper body 61 maintains the upright second state. Further, when the stopper body 61 stands up and is converted into the second state, the stopper receiving portion 67 stops immediately below the end portions of the curbstone bodies 3 and 3, and the stopper receiving portion 67 also moves to the second curbstone bodies 3 and 3. Since the width of the curb body 3 is set wider than the gap, even if a downward force is applied to one or both of the curb body 3 by a player stepping on the curb body 3 by mistake, The lower surface of the end portion comes into contact with the stopper receiving portion 67 and cannot descend. That is, the stopper receiving portion 67 of the stopper body 61 converted to the second state abuts the lower surface of the end portion of the curb body 3 to prevent the curb body 3 from descending. Therefore, even if a downward force is accidentally applied to the protruding curb body 3, it is possible to prevent the curb body 3 from descending.

Even if the curb body 3 projects from the ground surface and the stopper body 61 is changed to the upright second state, a gap D2 is formed between the lower surface of the curb body 3 and the stopper receiving portion 67 of the stopper body 61. The dimensions and mounting positions of each member are set so that the above can be achieved. Therefore, the gap D2 serves as a pressing margin necessary for changing the state of the latch unit 15.

In the field competition, when the upper part of the stopper body 61 is laterally pressed by using the above-mentioned tool or the like, the stopper body 61 returns around the support shaft 65 and pivots to fall down. The state returns to 1 (one-dot chain line in FIG. 9). Therefore, as described above, when the curb body 3 is pushed down against the biasing force of the spring 28, the latch unit 15 is contracted and the curb body 3 is housed in the groove 2.

The descent prevention stopper 62 is located below the edge of the curb body 3 which is in a first state in which it is stopped at a position lower than the ground surface and which protrudes from the ground surface, and descends the curb body 3. The stopper body 61 is not limited to the above as long as it has the stopper body 61 that can be converted into the blocking second state. For example, the stopper body 61 may be a lever-shaped member having a stopper receiving portion formed at one end. Further, the state maintaining member 66 may be configured to maintain the posture of the stopper body 61 by a frictional force.

In each of the above-described embodiments, the latch unit 15 in which the curb body is biased upward by the spring 28,
15 ', the present invention is convertible into an axially shortened first state and an elongated second state, the first
When the upper part is pulled up in the state, the extended second state is held,
If a latch unit that releases the holding of the second state and returns to the first state and holds the first state when the upper part is pulled up once in the second state is provided, the spring 28 does not necessarily urge the spring upward. .

For example, in another embodiment of the inner sphere curb shown in FIGS. 11 to 15, the latch unit 70 is attached to the support base 7 fixed in the groove 2 in the longitudinal direction, and the curb main body is attached by the latch unit 70. 3 is supported so that it can move up and down,
In the first state of the latch unit 70, the upper surface of the curb body 3 is below the ground surface, and in the second state, the upper surface of the curb body 3 projects to a predetermined height above the ground surface.
The structure for setting the stroke of 0 is the same as that of the above-described embodiment, but the spring for urging the curb body 3 upward is not provided.

This latch unit 70 includes a support base 7
A vertically elongated slide guide 71, a slide member 72 slidably fitted in the slide guide 71 in the vertical direction, a rotary cam 73 axially mounted on the slide guide 71 side, and the rotary cam 73. It is composed of a cam rotating member 74 and the like which is rotated by the vertical movement of the slide member 72, and the curb body 3 is screwed to the upper portion of the slide member 72 via the bracket 11 similarly to the above embodiment.
It is fixed at 5.

The slide guide 71 is a partially opened rectangular tubular body or a substantially U-shaped member in cross section, which is open except for both side edge portions of one wide side surface, and has a first portion on the upper side of one narrow side surface. The window 76 is opened. Then, the slide guide 71
The rotating cam 73 is attached to the inside of the shaft 77 in a rotatable state by the shaft 77, and a part of the rotating cam 73 can be projected from the first window 76. Further, when the rotary cam 73 becomes vertically long, the inner surface of the side surface where the first window 76 is opened and the rotary cam 7 are formed.
The rotary cam 73 is arranged at a position where there is an interval through which the slide member 72 can pass.

As shown in the drawing, the rotary cam 73 is formed by forming a substantially V-shaped notch 78, 78 on the short side of a rectangle, and the slide guide 71 is formed by a shaft 77 inserted through a hole formed at the center. Is pivoted on.

In the embodiment shown in the drawings, the height adjusting mechanism is not provided but is directly fixed to the support base 7 with bolts. However, when the height adjusting mechanism is provided so that the height can be finely adjusted. Is the slide guide 7 as in the above embodiment.
1 is fitted with a cylindrical body having a male screw portion, or a slide guide 71 is formed with a male screw portion, and the cylindrical body having a female screw portion which is screwed to the male screw portion is fixed to the support base 7. do it.

The slide member 72 is a partially open rectangular tubular body or a substantially U-shaped member having a substantially U-shaped cross section, which is open except for both side edge portions of the one wide side surface.
A window 79 is opened, and a vertically long cam rotation member 74 is provided so as to project downward from the inside. In addition, the cam rotating member 74 has a second upper end.
The rotary cam 73 is located at substantially the same height as the lower opening edge of the window 79 and at the center of the width of the slide member 72.
When it rises when it is vertically stopped, it abuts on the inclined side of the lower cutout portion 78 opposite to the second window 79, and when it rises when the rotation cam 73 is diagonally stopped, the rotation cam 73 It is arranged at a position where it abuts the lower inclined part of the long side. Therefore, the size of the rotating cam 73 is also formed to satisfy the above conditions. Also, the slide member 72
Is set so that it can slide inside the slide guide 71 and cannot come off.

When the slide member 72 is assembled in the slide guide 71, the rotary cam 73 of the slide guide 71 faces the inside of the slide member 72 from the open side surface of the slide member 72, and the first window 76 and the first window 76 2 windows 7
The slide member 72 is inserted into the hollow portion of the slide guide 71 in the direction in which 9 and 9 overlap.

Next, the operation of the latch unit 70 having the above structure will be described. In the state where the curb body 3 is descended and stored in the groove 2, the curb body 3 and the groove 2 are
Although there is a slight gap between the inner wall and the inner wall, it is difficult to put a hand or a finger in this gap, and therefore, in order to pull up the stored curbstone body 3, the lower end of the bar is a pulling tool with a horizontal bend ( It is preferable to use (not shown). Further, the curb body 3 is arranged at one side in the groove 2, and as shown in FIG. 13, a gap formed between the curb body 3 and one side surface of the curb body 3 is larger than the other gap in the housed state. . Therefore, when pulling up the curb body 3, the above-mentioned pulling tool is inserted into the larger gap from above and the
The curb body 3 is pulled up by raising the pulling tool in such a state that the part which is rotated by 0 degree and bent in the horizontal direction is hooked on the lower surface of the curb body 3.

As shown in FIG. 12A, when the slide member 72 descends and deeply overlaps with the slide guide 71, the latch unit 70 is in the axially shortened first state, and the rotary cam 73 is in the vertically long posture. It has stopped. Then, in this first state, the upper surface of the curb body 3 is below the ground surface. Therefore, this is the first state when performing a field competition.

When the curb body 3 is pulled up in this first state, the slide member 72 is also raised, and when the curbstone body 3 is raised sufficiently, the upper end of the cam rotating member 74 is positioned above the rotating cam 73, as shown in FIG. 12 (b). It abuts on one inclined side of the downward cutout portion 78. Since the position where the cam rotating member 74 contacts is the inclined side farther from the shaft 77 with respect to the second window 79, when the curb body 3 is further pulled up, the rotating cam 73 moves counterclockwise in the figure, that is, The upper end starts to rotate in the direction toward the second window 79. When the rotary cam 73 rotates sufficiently, the inclined side of the downward cutout 78 on the side of the second window 79 contacts the side surface of the cam rotary member 74, and further rotation is prevented. Therefore, this state is the top dead center. Further, in this state, one of the upper corners of the rotary cam 73 is
It slightly projects to the outside from the first and second windows 76 and 79 which are in communication with each other.

When the lifting tool is removed in this state, the curb body 3 is lowered by its own weight, and the slide member 72 is also lowered. When the slide member 72 descends, the rotating cam 73
Since one of the upper corner portions of the second window 79 projects from the second window 79, the upper opening edge of the second window 79 abuts the inclined side on the projected corner portion side from above so that the rotating cam 73 is reversed. Start to rotate clockwise. When the slide member 72 further descends, as shown in FIG. 12C, the other inclined side of the upward cutout portion 78 of the rotary cam 73 comes into contact with the inner surface of the slide member 72. Therefore, the rotation cam 73 is stopped by further rotation and stopped, whereby the lowering of the slide member 72 is stopped and the latch unit 70 holds the extended second state. Therefore, the curb body 3 stops while protruding from the ground surface and maintains this protruding state.

The effective stroke of the latch unit 70 (the slide member 72 is lowered to the bottom dead center and shortened so that the height when the curb body 3 is projected from the ground surface and stopped is a predetermined height. The length from the position of the first state to the top dead center, that is, from the entire stroke, is lowered from the top dead center to the second position.
The stroke obtained by subtracting the operation stroke until stopping in this state) is set in advance.

Also in this embodiment, as in the above-described embodiment, since the descent prevention stopper 62 is provided,
When the curbstone body 3 is pulled up and converted into a protruding state of a predetermined height, the stopper body 61 is raised to prevent the curbstone body 3 from being lowered.

When the curb body 3 is to be housed in the groove 2 for playing a track competition in such a state and then for a field competition, first, the lowering prevention stopper 62 is removed and the curb body 3 is held by hand. It suffices to temporarily pull up using the pulling tool, release the holding of the latch unit 70 in the second state by this operation, and then release it.

That is, once the curb body 3 is pulled up in the second state, the slide member 72 rises, the upper opening edge of the second window 79 is disengaged from the rotating cam 73, and the slide member 72 is further moved.
When is raised, the upper end of the cam rotating member 74 abuts near the inclined lower end of the long side of the rotating cam 73 that is obliquely stopped, and the rotating cam 73 starts rotating counterclockwise in the figure. In addition,
When the rotary cam 73 rotates counterclockwise, the length protruding from the second window 79 increases. Then, the slide member 72 is further raised to rotate the rotary cam 73, as shown in FIG.
As shown in (d), the rotary cam 73 becomes horizontally long, and the lower opening edge of the second window 79 contacts the lower long side of the rotary cam 73.

In this state, a second shaft is provided on both sides of the shaft 77.
Since the lower opening edge of the window 79 and the upper end of the cam rotating member 74 come into contact with each other, the rotating cam 73 functions as a stopper without rotating any further and the rotating cam 7
The stopper function of 3 prevents the slide member 72 from further rising and stops at this position.

Then, when the curbstone body 3 is released in this state and allowed to fall freely (pressed downward by gravity), the slide member 72 descends by the weight of the curbstone body 3 and the slide member 72 itself, and the second window is opened. When the lower opening edge of 79 and the upper end of the cam rotation member 74 are both separated from the lower long side of the rotation cam 73, and the slide member 72 is further lowered, the second window 79
The upper opening edge comes into contact with the upper long side outside the shaft 77 of the rotating cam 73 from above to start rotating the rotating cam 73 counterclockwise in the drawing.

When the slide member 72 is further lowered and the upper opening edge of the second window 79 further rotates the rotating cam 73 so that the rotating cam 73 is in a vertically long posture, the upper opening edge of the second window 79 is further moved. Since the rotating cam 73 cannot be rotated, as shown in FIG. 12 (e), the rotating cam 73 is stopped in a vertically long and almost vertical posture, and when the slide member 72 is sufficiently lowered, the rotating cam 73 is brought into the shortened first state. Return.

The bracket 1 is used as a stopper mechanism for determining the lowermost position (bottom dead center) of the slide member 72.
The lower surface of 1 may be configured to abut on the upper end of the slide guide 71, or a stopper and a slide member 72 that abut on the upper end of the slide guide 71 may be provided separately. Further, as shown in FIG. 14, a guide leg portion 12 and a guide tube portion 14 for guiding the vertical rise and fall of the curbstone body 3.
A stopper mechanism may be provided on the side of. That is, the bottom dead center of the curb body 3 and the slide member 72 may be regulated by abutting the large-diameter step portion 12 ′ of the guide leg portion 12 hung from the bracket 11 on the upper end of the guide tube portion 14.

[0079]

As described above, according to the present invention, the following effects can be obtained. The invention according to claim 1 holds the curb body in a state of protruding to a predetermined height from the ground surface by a simple operation of simply pulling up a plurality of curb bodies installed at the boundary between the track and the field. Also, it can be stored in the groove and returned to the unobtrusive state.

Therefore, the switching operation between the state in which the curb body is projected and the track is played and the state in which the curb body is housed in the groove and the field game is performed can be completed within a short time. Further, since this work is a simple operation that can be performed without having to sit down each time, it becomes a light work, and even an elderly worker or a female worker can easily perform it.

Further, since the curb body can be stored in the groove at that position without moving in the longitudinal direction, there is no problem even at the connecting portion between the straight line and the corner.
Therefore, the structure can be simplified.

According to the second aspect of the invention, a state in which the curb body is projected to a predetermined height from the ground surface by a simple operation of merely pushing down the curb bodies, which are installed at the boundary between the track and the field, from above And, it can be easily converted into a state where it is stored in the groove and does not get in the way.

Therefore, the switching work between the state in which the curb body is projected and the track is played and the state in which the curb body is housed in the groove and the field game is performed can be completed in a shorter time. . Also, this work
Since it is a simple operation of pressing the curbstone body downward once, it becomes a light work, and even an elderly worker or a female worker can easily and surely perform it.

Further, since the curbstone main body can be stored in the groove at that position without moving in the longitudinal direction, there is no problem even at the connecting portion between the straight line and the corner.
Therefore, the structure can be simplified.

According to the third aspect of the present invention, since the height of the latch unit with respect to the support base 7 can be adjusted, the height of the curb body can be easily adjusted to a predetermined height. Therefore, not only the construction time can be shortened and also the adjustment work at the time of maintenance and inspection can be completed in a short time, and at the same time, high accuracy can be maintained at all times.

According to the fourth aspect of the present invention, since the descent prevention stopper for preventing the descent of the curb body protruding from the ground surface is provided, even if an athlete or the like accidentally steps on the curb body, the curb body will be It never descends. Therefore, the track competition can be continued without any trouble.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a state where a curb body is housed in a groove.

FIG. 2 is a cross-sectional view showing a state where the curb body is raised to a predetermined height.

FIG. 3 is a front view showing a state where the curb body is raised to a predetermined height.

FIG. 4 is an enlarged cross-sectional view in a state where the curbstone body is raised to a predetermined height.

FIG. 5 is a cross-sectional view of the latch unit in which the curbstone main body is housed in the groove in a shortened first state.

FIG. 6 is a cross-sectional view of the latch unit that raises the curb body to a predetermined height in an extended second state.

7A and 7B are explanatory views of the first embodiment of the latch unit, FIG. 7A is a plan view of the inner member, FIG. 7B is a side view of the inner member, and FIG. 7C is a leaf spring with the inner member and the locking portion. Front view of the
(D) is a bottom view of the inner member.

8A and 8B are explanatory views of the second embodiment of the latch unit, FIG. 8A is a partially cutaway front view of the latch unit in an extended second state, and FIG. 8B is a view from the second state shown in FIG. 8A. The front view of the lid member showing a state where the slider is lowered and the rotary cam is tilted at the lower end of the guide groove, (c) is a front view of the latch unit in the reduced first state with the lid member removed,
(D) is a front view of the rotary cam showing a state in which the slider is lowered from the first state shown in (c) to change the posture at the lower end of the guide groove, and (e) is rotated from the state shown in (d). FIG. 7 is a front view of the rotary cam showing a state in which the cam moves up to change its posture.

FIG. 9 is a side view of the lowering prevention stopper in a state where the stopper body is erected.

FIG. 10 is a front view of the lowering prevention stopper shown in FIG.

11A is a plan view of a third embodiment of a latch unit, and FIG. 11B is a partially cutaway front view of the latch unit shown in FIG.

FIG. 12 is a partially cutaway front view showing the operation of the latch unit shown in FIG. 11, where (a) shows the first state in which the curbstone main body is housed in the groove by shortening, and (b) shows the curbstone main body. (C) shows the second state in which the curb body is extended and protrudes from the ground surface to support it, and (d) shows the second state from the curb. The state where the main body is pulled up and the second state is released,
FIG. 6 is a partially cutaway front view showing the slide member being lowered and shortened from the released second state.

13 is a front view showing a state where the curb body is supported by the latch unit shown in FIG.

FIG. 14 is a front view of a guide leg portion and a guide cylinder portion that guide the vertical rise and fall of the curb body and also serve as a stopper mechanism that regulates the lowermost position of the curb body.

[Explanation of symbols]

1 Inner sphere curb 2 Groove formed at the boundary between track and field 3 Curb body 4 Concrete block for drainage channel 5 L-shaped material 7 Support base 7 11 Bracket 11 12 that attaches the upper end of leg to the lower surface of curb body 11 12 Guide Leg part 12 13 Support leg part 14 Guide cylinder part 14 15 Latch unit 17 Cylinder body 21 Engagement groove 22 Convex part 23 Rotation stopper 25 Guide groove 26 Outer cylinder member 27 Inner member 28 Spring 29 Engagement leaf spring 30 Inside Material head 31 Male screw part 32 Partition wall 33 Spring housing empty part 34 Guide cam 35 Locking recess 36 Direction control cam 37 Top dead center cam 39 Guide piece 40 Locking part 41 Leaf spring part 42 Mounting part 45 Rotating cam 46 Slider 47 Guide groove 48 Casing 49 Cover member 53 Wide part of guide groove 61 Stopper body 62 Fall prevention Stopper 63 Standing portion 64 Stay 65 Support shaft 77 66 State maintaining member 67 Stopper receiving portion 70 Latch unit 71 Slide guide 72 Slide member 73 Rotating cam 74 Cam rotating member 75 Screw 76 First window 77 Rotating cam shaft 78 Notch 79th 2 windows

Claims (4)

[Claims] 1. A groove having an open upper surface and capable of accommodating a curb body is formed at a boundary between a track and a field of an athletic field, and the curb body is arranged along the groove, and inside the groove. The support base is fixed, and it is possible to convert the support base into an axially shortened first state and an extended second state, and when the upper portion is pulled up in the first state, the extended second state is retained. Once the upper part is pulled up in the second state, a latch unit for releasing the holding of the second state and returning to the first state and holding the first state is provided in the vertical direction, and the curb body can be moved up and down by the latch unit. The stroke of the latch unit is set so that the upper surface of the curb body is below the ground surface in the first state of the latch unit and the upper surface of the curb body projects to a predetermined height above the ground surface in the second state. And track and field competition Inner-sphere curb in the field. 2. A groove having an open upper surface and capable of accommodating a curb body is formed at a boundary between a track and a field of an athletic field, and the curb body is arranged along the groove, and inside the groove. The supporting base is fixed, and each time the supporting base receives a pressing force in the axial direction, the supporting base is converted into a shortened first state and an expanded second state, and the state is maintained until the next pressing force is received. A latch unit is provided in the vertical direction, and the curb body is supported by the latch unit so as to be vertically movable. In the first state of the latch unit, the upper surface of the curb body is below the ground surface, and in the second state, the upper surface of the curb body is in the ground. An inner-sphere curb on an athletic stadium characterized in that the stroke of the latch unit is set so as to project to a predetermined height above the surface. 3. The inner sphere curb in an athletic stadium according to claim 1, further comprising a height adjusting mechanism for adjusting the height of the latch unit with respect to the support base. 4. A first state in which the curb body is stopped at a position lower than the ground surface and a second state in which the curb body is located below the end portion of the curb body that has protruded from the ground surface and is raised to prevent the curb body from descending. The inner curb at an athletic stadium according to any one of claims 1 to 3, wherein a descent prevention stopper having a stopper body capable of being provided is provided in the groove.