US20070173379A1

US20070173379A1 - Impact absorbing gymnastic mat

Info

Publication number: US20070173379A1
Application number: US11/649,375
Authority: US
Inventors: Atsushi Harinishi; Katsuo Kita
Original assignee: Ashimori Industry Co Ltd; NGC Corp
Current assignee: Ashimori Industry Co Ltd; NGC Corp
Priority date: 2004-07-09
Filing date: 2007-01-04
Publication date: 2007-07-26
Also published as: WO2006006216A1

Abstract

In some preferred embodiments, an impact absorbing gymnastic mat 1 includes a mat body 10 having an air-tight space 14 therein, and an openable and closable air supply and discharge port 22 for supplying and discharging air into and from the air-tight space 14 of the mat body 10. The air supply and discharge port 22 is provided at a prescribed portion of the mat body 1. The mat body 1 includes a joined member 11 and an air impermeable external sheet 20 and 21 encasing the joined member 11 so as to form the air-tight space 14. The joined member 11 includes a pair of internal sheets 12 a and 12 b opposed at a prescribed distance and a plurality of connecting threads 13 connecting opposed surfaces of the internal sheets 12 a and 12 b.

Description

RELATED APPLICATIONS

This application is a continuation-in-part of PCT/JP2004/009824, filed on Jul. 9, 2004. The entire disclosure of the application is incorporated herein by reference in its entirety. This application claims the benefit pursuant to 35 U.S.C. §120 of the filing date of International Patent Application No. PCT/JP2004/009824, filed on Jul. 9, 2004.

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present invention relates to an impact absorbing gymnastic mat preferably used for gymnastic practices of, e.g., tumbling, a horizontal bar, floor exercise, a vaulting horse, rings, a pummel horse, parallel bars, uneven parallel bars, a balance beam, or skipping rope, and also used for school gymnastic activities.
2. Description of Related Art
The following description sets forth the inventor's knowledge of related art and problems therein and should not be construed as an admission of knowledge in the prior art.
At the time of performing gymnastic activities, in order to absorb the impact due to, e.g., landing, or unexpected falling or dropping of a gymnast, an impact absorbing gymnastic mat is laid on a floor. In recent gymnastics, especially in the case of a horizontal bar, etc., the impact of landing, etc., tends to increase with the advance of skills. In order to enhance the safety of gymnasts by sufficiently absorbing the impact in a balanced manner, technology of an impact absorbing gymnastic mat is being currently developed.
In an impact absorbing gymnastic mat used at the time of practicing tumbling or skipping rope, in order to absorb the impact to a body of a gymnast, it is required that the impact resilience is higher than that of the aforementioned landing impact absorbing mat.
As a conventional impact absorbing gymnastic mat, a mat in which shock absorbing material of foamed synthetic resin is filled in a cover seat of tarpaulin or canvas is generally used (For example, see Japanese Patent Publication No. 2595468, Japanese Unexamined Laid-open Patent Publication No. H11-76452, Japanese Unexamined Laid-open Patent Publication No. H11-244412).
In such a conventional impact absorbing gymnastic mat, although the impact absorbing material is foamed synthetic resin, it is still heavy because of its large size having an area that can safely receives a body of a gymnast. This requires assistance in carrying and disposing it on a floor. Furthermore, since the restoring force against the folding is high, the mat cannot be folded at the time of the storage, thereby requiring a large storage space.
Furthermore, in practicing tumbling, if a mat is insufficient in impact resilience, a large burden/fatigue will be imposed on the gymnast. As a result, the gymnast has no other choice to limit the amount of practice.
Furthermore, proper impact resilience of a gymnastic mat differs depending on the user's age and/or the activities. In a conventional mat, however, the impact resilience cannot be adjusted and that the elastic force can be inevitably deteriorated by the aged deterioration of the impact absorbing material.
The description herein of advantages and disadvantages of various features, embodiments, methods, and apparatus disclosed in other publications is in no way intended to limit the present invention. Indeed, certain features of the invention may be capable of overcoming certain disadvantages, while still retaining some or all of the features, embodiments, methods, and apparatus disclosed therein.

SUMMARY OF THE INVENTION

The preferred embodiments of the present invention have been developed in view of the above-mentioned and/or other problems in the related art. The preferred embodiments of the present invention can significantly improve upon existing methods and/or apparatuses.
Among other potential advantages, some embodiments can provide an impact absorbing gymnastic mat having sufficient impact absorption to decrease a burden to a body of a gymnast.
Among other potential advantages, some embodiments can provide an impact absorbing gymnastic mat which is light in weight, easy in storage, and adjustable in impact resilience.
According to a first aspect of a preferred embodiment of the present invention, an impact absorbing gymnastic mat, comprising:

- a mat body having an air-tight space therein; and
- an openable and closable air supply and discharge port for supplying and discharging air into and from the air-tight space of the mat body, the air supply and discharge port being provided at a prescribed portion of the mat body,
- wherein the mat body includes a joined member and an air impermeable external sheet encasing the joined member so as form the air-tight space; and
- wherein the joined member includes a pair of internal sheets opposed at a prescribed distance and a plurality of connecting threads connecting opposed surfaces of the internal sheets.

With this impact absorbing gymnastic mat, the impact resilience can be controlled by adjusting the air pressure within the mat body, so that impact resilience suitable for the user's age and the content of the sport can be obtained and that desired impact resilience can be reproduced any number of times. Furthermore, since the mat is light in weight and can be freely fold up by discharging the air to dissipate the impact resilience, the mat can be easily carried and stored in a small space.
In the aforementioned impact absorbing gymnastic mat, the internal sheet is preferably a woven fabric. In this case, the stretch of the external sheet can be controlled to thereby maintain the flatness of the mat, and weaving of the connecting threads into the internal sheets can be advantageously performed.
In the aforementioned impact absorbing gymnastic mat, the connecting threads are preferably weaved into the fabric. In this case, strong connecting strength can be attained.
In the aforementioned impact absorbing gymnastic mat, it is preferable that a density of the connecting threads is 1 to 5 pieces/cm². In this case, suitable strength can be secured.
The external sheet is preferably made of urethane series resin. In this case, it becomes possible to obtain a mat excellent in various characteristics, such as, e.g., elastic modulus, load bearing, mechanical strength, oil resistance, chemical resistance, and wear-resistant.
The external sheet preferably is adhered to a surface of the mat body. In this case, by selecting the material of the external sheet, the surface characteristics of the mat can be changed arbitrarily.
The external sheet is preferably a raised sheet. In this case, a mat having a pleasant texture can be obtained.
The external sheet is preferably adhered to a surface of the mat body via an auxiliary sheet. In this case, any external sheet poor in adhesiveness to the mat body can also be used.
According to a second aspect of a preferred embodiment of the present invention, an impact absorbing gymnastic mat, comprising:

- a mat body having an air-tight space therein; and
- an openable and closable air supply and discharge port for supplying and discharging air into and from the air-tight space of the mat body, the air supply and discharge port being provided at a prescribed portion of the mat body,
- wherein the mat body includes a pair of opposed upper and lower sheets disposed at a prescribed distance, and a plurality of connecting members connecting opposed surfaces of the upper and lower sheets, and
- wherein a density of the connecting members is 1 to 5 pieces/cm².

In this impact absorbing gymnastic mat, it is preferable that the upper and lower sheet are woven fabrics and that the connecting threads are weaved into the fabrics.
It is also preferable that the mat is further provided with an external raised sheet adhered to the upper surface of the main body.
The above and/or other aspects, features and/or advantages of various embodiments will be further appreciated in view of the following description in conjunction with the accompanying figures. Various embodiments can include and/or exclude different aspects, features and/or advantages where applicable. In addition, various embodiments can combine one or more aspect or feature of other embodiments where applicable. The descriptions of aspects, features and/or advantages of particular embodiments should not be construed as limiting other embodiments or the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The preferred embodiments of the present invention are shown by way of example, and not limitation, in the accompanying figures, in which:
FIG. 1A is an entire perspective view showing an embodiment of an impact absorbing gymnastic mat according to the present invention;
FIG. 1B is an enlarged cross-sectional view taken along the line 1B-1B in FIG. 1A;
FIG. 2 is an enlarged partial cross-sectional view showing another airtight sealing method for sealing a peripheral edge of the impact absorbing gymnastic mat; and
FIG. 3 is an enlarge partial cross-sectional view showing a principal portion of another embodiment of an impact absorbing gymnastic mat according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the following paragraphs, some preferred embodiments of the invention will be described by way of example and not limitation. It should be understood based on this disclosure that various other modifications can be made by those in the art based on these illustrated embodiments.
An embodiment of an impact absorbing gymnastic mat according to the present invention is shown in FIG. 1A and FIG. 1B.
This impact absorbing gymnastic mat 1 is configured to absorb impact by impact resilience obtained by introducing compressed air in the mat body 10.
The mat body 10 is constituted by a joined member 11 defining the planar dimension and thickness of the mat 1, and an external sheet 20 covering the joined member 11 to secure airtightness and strength.
The joined member 11 is constituted by two internal sheets 12 a and 12 b each consisting of a rectangular fabric corresponding to the planar dimension of the mat 1, and a number of connecting threads 13 of a predetermined length connecting the opposed surfaces of the inner sheets 12 a and 12 b. The connecting threads 13 are constituted by some weaving threads forming one of the internal sheets 12 a and pulled out therefrom and weaved into the other internal sheet 12 b as its weaving threads and some weaving threads forming the other internal sheet 12 b pulled out therefrom and weaved into the one of the internal sheet 12 a as its weaving threads. Weaving of the weaving threads pulled out of and weaved into the sheets 12 a and 12 b is repeated over the entire surfaces of the internal sheets 12 a and 12 b to thereby connect the two internal sheets 12 a and 12 b at a distance corresponding to the length of the weaving thread 13. Thus, a space 14 is formed between the opposed internal sheets 12 a and 12 b. That is, the length of the connecting thread 13 defines the thickness of the space 14, or the thickness of the mat body 10.
The internal sheets 12 a and 12 b define the planar dimension of the mat 1 while holding the connecting threads 13, and can be any members so long as it has the aforementioned functions. Each of the internal sheets 12 a and 12 b is covered by an external sheet 20, which will be mentioned later, to be reinforced by the external sheet 20. Therefore, each of the internal sheets 12 a and 12 b itself is required to have strength and/or connecting thread holding force capable of bearing the internal pressure of the mat 1. Therefore, the fabric constituting each of the internal sheets 12 a and 12 b can be thin and coarse. Such a fabric can be, e.g., a kint fabric, and a nonwoven fabric, as well as various woven fabrics. Among other things, a woven fabric, which is capable of keeping the flatness of the mat 1 by regulating the stretch of the external sheet 20 due to the internal pressure of the mat body 10 and has an advantageous in weaving a number of connecting threads 13, can be preferably used.
The connecting thread 13 defines the thickness of the space 14 which is a distance between the two internal sheets 12 a and 12 b, or the thickness of the mat body 10, in a state in which tension is given to the connecting thread 13 by the internal pressure. Therefore, it is preferable that the connecting threads 13 exist evenly on the entire surfaces of the internal sheets 12 a and 12 b to secure the uniform thickness. The density of the connecting threads 13 is preferably 1 to 5 pieces/cm². If it is less than the aforementioned lower limit, it becomes difficult to equalize the thickness of the mat 1 and maintain the strength against the internal pressure. On the other hand, even if the density exceeds the aforementioned upper limit, the number of manufacturing steps merely increases without producing specific effects. It is more preferable that the density of the connecting threads 13 falls within the range of from 2 to 3 pieces/cm². In this embodiment, the internal sheets 12 a and 12 a and the connecting threads 13 are strongly connected at a distance by weaving the joining threads 13 constituting one of the internal sheets into the other internal sheet 12 a(12 b). In the present invention, however, the two internal sheets 12 a and 12 b can be connected by simply stitching threads or yarns. The length of the joining thread 12 can be arbitrarily set in accordance with a desired mat thickness. In this embodiment, as shown in FIG. 1B, the connecting threads 13 are disposed in parallel between the internal sheets 12 a and 12 b. However, the connecting threads 13 can be disposed crossways for example.
In the aforementioned joined member 11, the material of the internal sheets 12 a and 12 b and that of the connecting thread 13 are not specifically limited, and can be natural or synthetic fibers, such as, e.g., cotton, rayon, nylon, polyester, or polypropylene. Furthermore, the internal sheets 12 a and 12 b and the connecting threads 13 can be made of the same or different fibers.
The joined member 11 is covered by upper and lower air impermeable external sheets 20 and 20 and a side external sheet 21 in an air-tightly sealed manner to thereby form the mat body 10 having an air-tightly sealed space.
Each external sheet 20 has the same size as that of the sheet 12 a, and is joined to the entire external surface of the internal sheet 12 a. On the other hand, the side external sheet 21 is formed into a tape-like shape having a width wider than the thickness of the joined member 11, and covers the four side surfaces of the joined member 11 with its widthwise end portions overlapped on the peripheral edge portion of the upper and lower external sheets 20 and 20. Thus, all of the upper, lower, and four side surfaces of the joined member 11 are covered in an air-tight manner, and a space 14 is formed in the mat body 10.
It is not always required that the internal sheets 12 a and 12 b and the upper and lower external sheets 20 and 20 are in agreement with the planar dimension of the mat 1. For example, as shown in FIG. 2, the dimension thereof can be set to be slightly larger than the planar dimension of the mat 1 so that the peripheral edge 20 a extends to the side surface of the mat 1. This reinforces the side surface portion of the mat 1.
The upper and lower surface external sheets 20 and 20 and the side surface external sheet 21 are air impermeable, and are made of materials having strength capable of bearing impact of gymnast's landing and internal pressure and having such flexibility that can be bent freely. Concrete examples of such sheets include synthetic resin sheets made of, e.g., vinyl chloride series resin, olefin series resin, or urethane series resin. Among other things, it is preferable to use a sheet made of urethane series resin in view of its various excellent characteristics, such as, e.g., modulus of elasticity, load bearings, mechanical strength, oil resistance, chemical resistance, and wear resistance. As urethane series resin, polyurethane elastomer excellent in modulus of elasticity can be especially recommended. For the purpose of improving various characteristics, such as, e.g., strength of the sheet, various fillers can be blended. Each of the sheets 20 and 21 is preferably 0.3 to 1.5 mm in thickness, from the viewpoint of reconciling the strength and the lightweight.
Joining of the upper and lower surface external sheets 20 and 20 and the side surface external sheet 21 is performed by a method capable of securing the airtightness, such as, e.g., pressure bonding, welding, and adhering with adhesive. In the case of joining the sheet 20 to the internal sheet 12 a (12 b), after applying synthetic resin to which fluidity is given onto the internal sheet 12 a (12 b), and then sheet forming is performed by curing and solidifying the resin. Moreover, since the joint portion 15 of the two internal sheets 12 a and 12 b tends to loose the airtightness, it is preferable to secure the airtightness by doubly adhering external sheets as shown in FIG. 2. FIG. 2 illustrates an example in which a narrow auxiliary external sheet 21′is adhered onto the joint portion 15 and a wide side surface external sheet 21 is further adhered thereon.
At the vicinity of the corner portion of the upper surface of the mat body 10, an air supply and discharge port 22 is provided. The air supply and discharge portion 22 penetrates the external sheet 20 and the internal sheet 12 a, and is openable and closable in an airtight manner with a valve or the like (not illustrated). The air supply and discharge port 22 is detachably connected by an air supplying pump (not illustrated) to supply air into the space 14 of the mat body 10 therethrough. Although it is sufficient to provide one air supply and discharge port 22, two or more air supply and discharge ports can be provided to enhance the air supply/discharge operation. Furthermore, the position of the supply and discharge port 22 is not specifically limited, and can be arbitrarily set on the upper surface, the lower surface, or the side surface of the mat body 1.
In the impact absorbing gymnastic mat according to the present invention, in view of the necessity of the airtightness of the mat body 10, as the external sheets 20 and 21, material with a minute and smooth surface, such as, e.g., a synthetic resin sheet mentioned above, is often used. However, such synthetic resin sheet is slippery, and therefore it does not always give a gymnast a good feeling at the time of landing. Surface characteristics, such as, e.g., textures, or frictional resistance, of such a gymnastic mat can be changed by adhering an exterior sheet with a predetermined surface characteristics on the surface of the mat body 10.
In the impact absorbing gymnastic mat 2 shown in FIG. 3, an exterior sheet 30 is adhered to the upper and lower surfaces of the mat body 10, respectively. The exterior sheet 30 is a carpet-like sheet having one side surface 30 a with a pleasant texture formed by raising one surface side 30 a of a woven sheet made of synthetic fibers and the other side surface 30 b with exposed irregularities of the texture. The exterior sheet 30 is joined to the mat body 10 such that the other side surface 30 b of the exterior sheet 30 stitched on an auxiliary sheet 31 which is the same in material as the upper and lower surface external sheets 20 is adhered to the upper (lower) external sheet 20 via the auxiliary sheet 31. The reason for adhering the exterior sheet 30 to the mat body 10 via the auxiliary sheet 31 is that directly stitching on the external sheet 20 looses the airtightness of the external sheet 20 due to the needle holes formed by the stitching and that the surface irregularities on the other side surface 30 b of the exterior sheet 30 cause deteriorated adhesive force to the external sheet 20. The method of joining the auxiliary sheet 31 to the external sheet 20 is not specifically limited unless it does not hurt the airtightness of the external sheet 20, and can be a pressure bonding method or a welding method. In cases where the exterior sheet 30 has high adhesion to the upper (lower) surface external sheet 20, the exterior sheet 30 can be directly adhered to the mat body 10 without being intervened by the auxiliary sheet 31.
In the aforementioned impact absorbing gymnastic mat 12, when air is supplied to the space 14 of the mat body 10 via the air supply and discharge port 22, the two internal sheets 12 a and 12 b will be moved away from each other so that the distance therebetween coincides with the length of the connecting thread 13. Thus, the mat body 10 has a predetermined thickness. When air is further supplied, since the clearance of the internal sheets 12 a and 12 b is regulated by the connecting threads 13, the air pressure rises while increasing the tension to the connecting threads 13 in a state in which a thickness is kept constant. Since the impact resilience is reflected in the air pressure, the impact resilience of the mat 1 can be freely controlled by setting the air pressure. Furthermore, so long as the mat 1 does not loose the airtightness, desired impact resilience can be reproduced any number of times.
The proper impact resilience of the mat differs depending on the age of the gymnast and the contents of activities. Proper values of impact resilience can be expressed with air pressure as follows: 10.3 kPa(s) (1.5 psi) for young children gymnastics; 12.4 kPa(s) (1.8 psi) for elementary school gymnastics; 13.8 kPa(s) (2.0 psi) for a woman's junior player's tumbling practice; 27.6 kPa(s) (4.0 psi) for a male player's tumbling practice. In practicing tumbling, when the mat 1 has impact resilience of the above-mentioned level, excessive load will not be imposed on the body of the gymnast, which in turn enable the gymnast to perform sufficient amount of practices. In cases where the mat 1 is used as a hopping mat for rope skipping practice or runways, it is preferable to adjust the air pressure depending on the weight of the gymnast. The following pressures can be set as a target: 13.8 kPa (2.0 psi) when the weight of the gymnast is 25 to 35 kg; 20.7 kPa (3.0 psi) when the weight is 45 kg; 24.1 kPa (3.5 psi) when the weight is 54 kg; and 27.6 kPa (4.0 psi) when the weight is 65 kg.
On the other hand, when the air in the mat body 10 is discharged, the tension to the connecting thread 13 is lost to release the restraint of the clearance between the internal sheets 12 a and 12 b, which in turn causes the impact resilience to disappear. Accordingly, the mat 1 (2) can be folded freely. In this mat 1 (2), since no shock absorbing material of foamed synthetic resin, which is normally used in a conventional mat, is used, the substantial weight is caused only by the mat body, and therefore it is light in weight. For this reason, the carrying operation can be easily performed and the storage space can be decreased.

INDUSTRIAL APPLICABILITY

The impact absorbing gymnastic mat according to the present invention can be used in, for example, performing or practicing various gymnastics.
While the present invention may be embodied in many different forms, a number of illustrative embodiments are described herein with the understanding that the present disclosure is to be considered as providing examples of the principles of the invention and such examples are not intended to limit the invention to preferred embodiments described herein and/or illustrated herein.
While illustrative embodiments of the invention have been described herein, the present invention is not limited to the various preferred embodiments described herein, but includes any and all embodiments having equivalent elements, modifications, omissions, combinations (e.g., of aspects across various embodiments), adaptations and/or alterations as would be appreciated by those in the art based on the present disclosure. The limitations in the claims are to be interpreted broadly based on the language employed in the claims and not limited to examples described in the present specification or during the prosecution of the application, which examples are to be construed as non-exclusive. For example, in the present disclosure, the term “preferably” is non-exclusive and means “preferably, but not limited to.” In this disclosure and during the prosecution of this application, means-plus-function or step-plus-function limitations will only be employed where for a specific claim limitation all of the following conditions are present in that limitation: a) “means for” or “step for” is expressly recited; b) a corresponding function is expressly recited; and c) structure, material or acts that support that structure are not recited. In this disclosure and during the prosecution of this application, the terminology “present invention” or “invention” may be used as a reference to one or more aspect within the present disclosure. The language present invention or invention should not be improperly interpreted as an identification of criticality, should not be improperly interpreted as applying across all aspects or embodiments (i.e., it should be understood that the present invention has a number of aspects and embodiments), and should not be improperly interpreted as limiting the scope of the application or claims. In this disclosure and during the prosecution of this application, the terminology “embodiment” can be used to describe any aspect, feature, process or step, any combination thereof, and/or any portion thereof, etc. In some examples, various embodiments may include overlapping features. In this disclosure and during the prosecution of this case, the following abbreviated terminology may be employed: “e.g.” which means “for example;” and “NB” which means “note well.”

Claims

1. An impact absorbing gymnastic mat, comprising:

a mat body having an air-tight space therein; and

an openable and closable air supply and discharge port for supplying and discharging air into and from the air-tight space of the mat body, the air supply and discharge port being provided at a prescribed portion of the mat body,

wherein the mat body includes a joined member and an air impermeable external sheet encasing the joined member so as form the air-tight space; and

wherein the joined member includes a pair of internal sheets opposed at a prescribed distance and a plurality of connecting threads connecting opposed surfaces of the internal sheets.

2. The impact absorbing gymnastic mat as recited in claim 1, wherein the internal sheet is a woven fabric.

3. The impact absorbing gymnastic mat as recited in claim 2, wherein the connecting thread is weaved into the fabric.

4. The impact absorbing gymnastic mat as recited in claim 1, wherein a density of the connecting threads is 1 to 5 pieces/cm².

5. The impact absorbing gymnastic mat as recited in claim 2, wherein a density of the connecting threads is 1 to 5 pieces/cm².

6. The impact absorbing gymnastic mat as recited in claim 3, wherein a density of the connecting threads 1 to 5 pieces/cm².

7. The impact absorbing gymnastic mat as recited in claim 1, wherein the external sheet is made of urethane series resin.

8. The impact absorbing gymnastic mat as recited in claim 1, wherein the external sheet is adhered to a surface of the mat body.

9. The impact absorbing gymnastic mat as recited in claim 2, wherein the external sheet is adhered to a surface of the mat body.

10. The impact absorbing gymnastic mat as recited in claim 3, wherein the external sheet is adhered to a surface of the mat body.

11. The impact absorbing gymnastic mat as recited in claim 4, wherein the external sheet is adhered to a surface of the mat body.

12. The impact absorbing gymnastic mat as recited in claim 5, wherein the external sheet is adhered to a surface of the mat body.

13. The impact absorbing gymnastic mat as recited in claim 6, wherein the external sheet is adhered to a surface of the mat body.

14. The impact absorbing gymnastic mat as recited in claim 7, wherein the external sheet is adhered to a surface of the mat body.

15. The impact absorbing gymnastic mat as recited in claim 8, wherein the external sheet is adhered to a surface of the mat body via an auxiliary sheet.

16. The impact absorbing gymnastic mat as recited in claim 8, wherein the external sheet is a raised sheet.

17. An impact absorbing gymnastic mat, comprising:

a mat body having an air-tight space therein; and

wherein the mat body includes a pair of opposed upper and lower sheets disposed at a prescribed distance, and a plurality of connecting members connecting opposed surfaces of the upper and lower sheets, and

wherein a density of the connecting members is 1 to 5 pieces/cm².

18. The impact absorbing gymnastic mat as recited in claim 17, wherein the upper and lower sheet are woven fabrics, and wherein the connecting threads are weaved into the fabrics.

19. The impact absorbing gymnastic mat as recited in claim 18, further comprising an external raised sheet adhered to an upper surface of the main body.

20. The impact absorbing gymnastic mat as recited in claim 17, wherein the density of the connecting threads is 2 to 3 pieces/cm².