WO1999020135A1

WO1999020135A1 - Shoes of excellent landing-shock absorption

Info

Publication number: WO1999020135A1
Application number: PCT/JP1998/004662
Authority: WO
Inventors: Keiun Kodo; Yasumasa Kodo
Original assignee: Technostar Co., Ltd.
Priority date: 1997-10-16
Filing date: 1998-10-15
Publication date: 1999-04-29
Also published as: JPH11113604A

Abstract

The present inventon can propose shoes of lightweight which enable to smoothly absorb shocks at landing in walking or running, to efficiently convert shock energy at landing into repulsion energy for kicking ground and to protect deformation of shoes due to shocks at landing, which are characterized in using a shoe sole having two or more airtight elastomer chambers, each of them being separately located in the sole and filled with compressed gas under desired pressure.

Description

DESCRIPTION

SHOES OF EXCELLENT LANDING-SHOCK ABSORPTION

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to shoes which have shock-absorption ability against pressure of shock brought upon soles of feet in walking or running, are superior to repulsion elasticity, have a light weight and are very comfortable at wearing of them in addition.

Description of Related Art

Until now many trials have been proposed in order to enhance comfortable feeling, especially shock-absorption ability against pressure of shock at landing, in wearing such various sports shoes as running, walking or jogging shoes. And actually various improved shoe products are being supplied in the market.

For example. United States Patents, 4,183,156, 4,219,945 and 4,340,626 disclosed mid-soles of a shoe composed of two or more gas containing chambers which were connected each other through intercommunicating passages. Moreover, Japanese Laid-Open Patent, Heisei 2-17002 disclosed shoe soles having a mid-sole composed of an airtight chamber. Various shoe products, using such an airtight chamber for absorbing shock at landing, have been supplied in the market. For example, sports shoes called as " Air max " which are being sold by NIKE Corporation, U.S., and used a mid-sole composed of an airtight chamber as a shock-absorption system, have explosively got young people's favor in conjunction with fashion trend. Japanese Laid-Open Patent , Heisei 2-82901 proposed mid-soles using a specified elastomer unit at ball part or heel part of a shoe. Many shoe products, using a specified elastomer or a gel-type material as a shock absorber at landing, have been supplied in the market.

In existing shoes described above, in order to moderate pressure of shock at landing, elastomer materials have been adhered on a part of soles and airtight chambers maintained under prescribed pressure have been set in soles . There has not been considered how much power is brought to each portion of a sole of a foot corresponding to variation of movement from landing to leaving. For example. United States Patent, 4,219,945 disclosed a mid-sole in which two or more airtight chambers containing gas are located in order to enhance effect of shock absorption. But these airtight chambers are forced to connect each other through intercommunicating passages due to a limitation of conventional techniques for producing an airtight chamber, and when any of the intercommunicated airtight chambers has been broken by such a cause as shock, etc. , then immediately their airtight must be lost and the shock absorption effect must be disappeared as well. Moreover, due to intercommunication of the chambers, energy corresponded to pressure caused by shock at landing and absorbed by a heel portion of a shoe may be immediately moved to other portions, for example a ball portion. Next, when energy accumulated in the airtight chambers may be applied as energy for repulsion to kick at a ball portion, energy accumulated there may move to a heel portion to result in reduction of repulsion elasticity efficiency. In a case that elastomers may be used as a means for enhancing shock absorption , deformation , which results in considerable reduction shock absorption ability, can not be avoided by long lasting strain of compression due to repeated pressure of shocks.

In addition, any method using an elastomer or a gel-type material for absorbing shock energy have some disadvantage against reducing weight of shoe products. It is really popular that boundless efforts in designing and realizing less weight shoes for marathon racers have been continued, because they better or break the records in various races . Especially a long distance running such as marathon races may relate to weight of racing shoes . In other words, it is the lighter the better. Moreover, as the pressure of shock at landing and its repulsion for kicking may be ill-balanced in different portions of a shoe sole, shoes which can satisfy to fulfil desired functions at desired portions of a sole at landing and kicking ground have been sincerely requeste . These demands could not be satisfied in conventional shoes composed of two or more intercommunicated airtight chambers .

Recently, with the advancement of materials for shoes, shoes have had a variety of kinds depending on their purposes, that is, items of sports. And selections of materials and improvement in structures have been tried so as to meet their purposes. For example, renewal of records in marathon races has been well-known to be related to less weight of racing shoes, and may be affected by minute difference such as weight and size by a unit of one hundredth, or their durability. Marathon racers pay close attention to protection of their feet, alleviation of fatigue or maintaining their physical strength, considering their own feet may be influenced by a minute difference in shock absorption or repulsion elasticity. It is not too much to say that a meaningful difference in performance of shoes may have an important effect on preservation of physical strength of racers.

SUMMARY OF THE INVENTION

One of objects of the present invention is to propose shoes which can smoothly absorb shocks at landing in walking or running.

Another object of the present invention is to propose shoes in which energy of shock at landing can be efficiently converted into energy of repulsion.

Another object of the present invention is to propose shoes in which absorption of pressure of shock at landing and function as repulsion, which are variable depending on items of sports, can be accomplished on desired portions of a shoe sole.

The other object of the present invention is to propose shoes in which deformation of shoes due to shocks at landing can be protected and smooth landing can be guaranteed.

In addition to the objects mentioned above, one of the main objects of the present invention is to propose an extremely light shoes .

The shoes of the present invention can attain all of these objects at the same time.

BRIEF DESCRIPTION OF DRAWINGS

Fig. 1 is a schematic view of so-called sports shoes.

Fig. 2 is a schematic view to show a structure of a shoe sole.

Fig. 3 is a schematic view to show one composition of a shoe sole and collectively a configuration of an elastomer chamber of the present invention.

Figs. 4-10 are various views to show variety of configurations and shapes of the elastomer chambers of the present invention.

Fig. 11 is a schematic view of one of configurations of the elastomer chambers of the present invention where they have common partition with adjacent chambers.

Fig. 12 is a schematic view of a configuration of the elastomer chambers of the present invention which are positioned at a heel portion of a shoe sole. DETAILED DESCRIPTION OF PREFFERED EMBODIMENTS OF THE INVENTION

In order to achieve these objects of the present invention mentioned above, the shoes of the present invention are characteristic of using a sole having two or more airtight elastomer chambers , each of which is independently positioned in a sole and filled with compressed gas. In the shoes of the present invention, a sole may be anyone selected from the group of (A) a sole where at least two elastomer chambers have different inner pressure each other, (B) a sole in which a cross section of at least one elastomer chamber is one form selected from the group consisting of a circle, an ellipse, a concentric circle, a polygon, a spiral, a horseshoe and a ladder, (C) a sole where at least two elastomer chambers have different inner volume each other and (D) a sole where at least two elastomer chambers have common partition with adjacent chambers.

The shoes of the present invention are composed of a shoe body and a sole . The shoe body is generally made in a form of being able to wrap a whole foot including toe, instep and heel, and may be made in a form of a slipper to be able to wrap both parts of a toe and an instep.

The shoe sole has a construction of each corresponding sole to every portions to be got between a foot sole and a ground, that is, toe, ball, arch and heel portions.

" Two or more airtight elastomer chambers being filled with gas " as an essential element of the shoes of the present invention should be positioned inside of the shoe sole, hopefully inside of the mid-sole.

Some embodiments of the shoes of the present invention are illustrated in several figures as follows. For instance. Fig. 1 shows a schematic view of so-called sports shoes. It goes without saying that the shoes of the present invention should not be limited to this single figure. A sports shoe 1 consists of a shoe body 2 and a sole 3. The sole 3 consists of a toe sole 3a, a sole of ball portion 3b, an arch sole 3c and a heel sole 3d. Each of these soles is made in a corresponding form to be desired at respective portions of the shoe .

In general, the sole 3 consists of an insole 31, a mid-sole 32 and an out-sole 33 as shown in Fig. 2, but there may be a sole 34 united in a body of a mid-sole and an out-sole as shown in Fig. 3. Although a characteristic sole of the shoes of the present invention is described in detail after, two or more airtight elastomer chambers filled with gas 5, being placed in the sole of the present invention may be placed inside of the mid-sole 32 or inside of the sole 34 united in a body of a mid-sole and an out-sole as shown in Fig.3.

Materials for the elastomer chamber may be not limited so far as they have elongation of 200-2000% and do not leak gas sealed up in the chamber. For example, a thermoplastic elastomer which has no gas permeability may be preferably used. As a thermoplastic elastomer, may be mentioned an elastomer of polystyrene, poly(vinyl chloride), polyolefin, polyester, polyamide or polyurethane . All of these elastomers are available in the market and may be selected depending on purposes .

The elastomer chamber should be airtight and can keep gas under desired pressure. It is characterized that two or more elastomer chambers filled with gas are placed in the shoe sole of the present invention. In other words, there is characteristic that each of the elastomer chambers forms an independent airtight chamber, and pressure of gas to be filled inside of each chamber can be selectively settled at a desired value.

As described above, in conventional shoe soles proposed to moderate shock at landing by using two or more gas-filled airtight chambers , they could not avoid to intercommunicate each other within the limit of conventional techniques . However, the inventors of the present invention have discovered a novel process to form a gas -filled elastomer chamber by generating gas inside of an airtight chamber ( disclosed in Japanese Patent Application No. Heisei 9-118327 ) and then have made possible to form two or more airtight elastomer chambers filled with gas in one-step process, each of which is independent without intercommunicating each other. The shoes of the present invention can be realized by using this novel process.

A role of elastomer chambers to perform in the shoe sole of the present invention can be explained as follows : Elastomer chambers being provided in the sole of the present invention enable to perform the function to absorb or repulse the pressure received at every portion of the foot sole at landing. The pressure to be absorbed at landing or the power of repulsion for kicking ground are different in portions of the foot sole and their required portions are also variable depending on variation of movement .

The shoes of the present invention are those having a sole composed of two or more gas-filled elastomer chambers as an essential element. Arrangement design of such chambers in the shoe sole should correspond to powers brought to each portion of foot soles depending on variation of movement . Functions to be required in an elastomer chamber even at same portion in a foot sole is variable depending on different kinds of movement . For example , in a case of such movement as some shock pressure is received by a heel portion at landing, one or more elastomer chambers should be arranged at heel portion of the shoe sole.

Size, shape and arrangement of elastomer chambers should not be limited, and can be voluntarily designed to meet with the kind of movement and / or requirement in the portion of a foot sole. For example, in Fig. 4 which shows a mid-sole 4 of a shoe for a left foot as one of embodiments of the present invention, two or more elastomer chambers 5 are independently positioned. and in a heel portion 3d, an arrangement of a central chamber 5a of large volume and surrounding chambers 5b of smaller volume is shown. In a ball portion 3b, a chamber 5c of medium volume is surrounded by chambers 5b of smaller volume and is located near inner side of a foot sole.

In Fig. 5, an embodiment of combination of chambers 5, an arrangement of a central chamber 5a of larger volume and surrounding circular chambers 5b and a horseshoe-shaped chamber 5d of smaller volume is shown.

In Figs, from 6 through 10, variety of shapes and arrangements is shown. But the shape of elastomer chambers should not be limited. A shape may be in a form selected from the group consisting of a circle, an ellipse, a concentric circle, a polygon, a spiral, a horseshoe and a ladder as a cross section of chamber, and a combination of them also can be selected.

In the above description, is shown an embodiment in which two or more elastomer chambers are positioned independently from each other. It, however, should not be limited to this embodiment. Such an embodiment that a common wall of at least two adjacent chambers may be preferably selected. Fig.11 shows an arrangement in which truncated cone-type chambers 5e and 5f own common walls. Fig. 12 is a schematic view of a heel portion 3d in which an arrangement of chambers is shown in Fig. 11. For example, when pressure of shock at landing is brought to the chamber 5f , the chamber 5f deforms to release its energy and press the adjacent chamber 5e. The chamber 5e which has gotten compression energy also deforms to accumulate its energy. Thus, shock at landing can be relieved. In the next step, energy accumulated in the chamber 5e is transferred to and restored into the chamber 5f . The restored pressure can be converted into repulsion elasticity power at the chamber 5f .

As explained in the above description, an embodiment of such an arrangement that two or more chambers commonly own a common wall is a preferable one of the present invention, because reciprocal action between absorption of pressure of shock and generation of repulsion elasticity power can be efficiently applied. Honeycomb structure which can be formed by owning common walls by many adjacent chambers is a typical example of this arrangement, and an embodiment using honeycomb is one of the most preferable ones of the present invention.

As already shown in the figures , volume of two or more chambers may be voluntarily selected. Volume and inner pressure of a chamber can be designed in consideration of the desired functions at respective chambers, in other words, requirement in a portion of a foot sole corresponding to the chamber such as strength of pressure of shocks at landing and repulsion elasticity power of kicking ground.

Inner pressure of each chamber may be determined depending on strength of power put on each portion of a foot sole or repulsion elasticity power at the portion. In order to generate desirable pressure in each chamber, it may be used methods disclosed in the specification of Japanese Patent Application No. Heisei 09-118327 , filed by the present inventors . Those are the methods for preparing airtight chambers filled with gas, and may be realized by decomposition of gas producing composition placed inside of a chamber beforehand, which comprises a gas producing material and a pyrogenic material being able to generate heat by eddy current and hysteresis loss induced in magnetic field formed by a high frequency oscillator. Inner pressure can be controlled by dosage of gas producing materials and volume of the chamber.

EFFECTS OF THE PRESENT INVENTION

Shoes of the present invention can bring about various effects as described under , because of characteristics that their sole of two or more airtight elastomer chambers as an essential element . Every chambers are located in the sole without intercommunicating each other and filled with compressed gas : that is,

1 ) The present invention can propose shoes of light weight .

2) The present invention can propose a shoe sole without breaking possibility of the airtight chambers by shock at landing etc. Thereby excellent cushion ability can be maintained as far as the body keeps its life. The airtight chambers of the present invention are quite different from the chambers , which are intercommunicated each other, disclosed in United States Patent, 4,219,945 mentioned before.

3) The present invention enables to design and arrange elastomer chambers corresponding to functions to be desired in each portion of a foot sole. It proposes such shoes that are much more comfortable to wear and keep movement stable and safe in walking or running.

4) The present invention enables to utilize energy to be transferred in one chamber to another without loss for mutual action of shock absorption and repulsion elasticity power.

5) The present invention can propose shoes which enable to correspond to any function to be desired in a different kind of sports , by arranging more than two chambers having different inner pressure. It results to offer most preferable shoes for each of various kinds of sports .

6 ) The present invention can propose shoes which can make easy to cope with such a variation in walking and running as shift of body weight, running manner, condition of road surface, etc. And it results in better fitness and better secure not only for feet, but also for the whole human body.

7) In cooperation of various effects mentioned above, the present invention enables to achieve such physiological effects as easiness in movement and less fatigue to be accumulated.

Claims

1. Shoes with a sole which is characterized in having two or more airtight elastomer chambers, each of which is separately located in the sole and filled with compressed gas.

2. Shoes according to claim 1, wherein inner pressure of at least two chambers in the sole is different each other.

3. Shoes according to claim 1, wherein a cross section of at least one chamber in the sole has at least one form selected from the group consisting of a circle, an ellipse, a concentric circle, a polygon, a spiral, a horseshoe and a ladder.

4. Shoes according to claim 1, wherein volumes of at least two chambers in the sole are different each other.

5. Shoes according to claim 1, wherein at least two chambers have a common wall for adjacent chambers.

6. Shoes according to claim 1 , wherein gas is generated inside of the chamber by decomposition of a gas producing composition, comprising a gas producing material and a pyrogenic material, which is capable of generating heat by eddy current and hysteresis loss induced in magnetic field formed by a high frequency oscillator.

AMENDED CLAIMS

[received by the International Bureau on 17 March 1999 (17.03.99); original claim 6 cancelled; original claimsl,2 and 3 amended; remaining claims unchanged (lpage)]

1. Shoes with soles which are characterized in having two or more airtight elastomer chambers , each of which is separately located in the sole and filled with compressed gas, gas being generated inside of the chamber by decomposition of a gas producing composition, comprising a gas producing material and a pyrogenic material, which is capable of generating heat by eddy current and hysteresis loss induced in magnetic field formed by a high frequency oscillator.

2. Shoes according to claim 1, wherein inner pressure of at least two chambers in the sole are different each other.

3. Shoes according to claim 1, wherein a cross section of at least one chamber in the sole has at least one shape selected from the group consisting of a circle, an ellipse, a concentric circle, a polygon, a spiral, a horseshoe and a ladder.

4. Shoes according to claim 1 , wherein volume of at least two chambers in the sole are different each other.

5. Shoes according to claim 1 , wherein at least two chambers have a common wall for adjacent chambers.

6. ( deleted )

12

AMENDED SHEET(A_H1CLE19) Statement under Article 19

We enclosed a new set of the claims herewith.

We made clear that amended claim 1 would be aimed to define shoes with soles characterized in having two or more airtight elastomer chambers , each of which is filled with compressed gas , gas being generated inside of the chamber without charging gas from outside of the chamber.

Cited document EP 0 293 034 discloses a pneumatic sole for footwear having plural closed chambers . But the sole has at lest one non-return valve through which the internal enclosure bounded by the sole walls can be supplied with compressed air from outside of the sole. And compressed air is supplied to the sole interior, not to the closed chambers.

Cited document EP 0553736 discloses a shoe-sole having plural closed chambers which are filled with air or inert gas . But , this document does not only disclose a method for filling the chambers with gas , but also has no suggestion relating to a method for filling the closed chambers with compressed gas generated inside of the chambers .

Cited document FR 2 342 677, US 4 223455, FR 2261 721 and FR 1 190 358 disclose a shoe-sole having plural closed chambers . But , in these documents , any description relating to a method for filling the chambers with compressed gas.

The present invention proposes shoes with soles having a variety of airtight chambers , each of which can be filled with compressed gas at different inner pressure, so that the chambers may be designed and arranged depending on a variety of movement .