EP1814416A1

EP1814416A1 - Shock-absorbing device for shoes

Info

Publication number: EP1814416A1
Application number: EP05764935A
Authority: EP
Inventors: Jang Won Park
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-11-12
Filing date: 2005-04-13
Publication date: 2007-08-08
Also published as: US20080066342A1; MX2007005680A; BRPI0517821A; WO2006052052A1; CN101060796A; JP2008519643A; KR100642662B1; KR20060045243A

Abstract

The present invention provides a shock-absorbing device for shoes comprises a cross-linked foam having a body and at least one inner cavity formed in the body; and a housing containing the cross-linked foam. The shock-absorbing device of the present invention can easily be applied to soles of shoes having diverse sizes and shapes to effectively reduce an impact applied to a foot. Besides, the present invention can cut down a manufacturing cost greatly by simplifying a manufacturing process of the shock-absorbing device.

Description

SHOCK-ABSORBING DEVICE FOR SHOES

Technical Field

[1] The present invention relates to a shock-absorbing device for shoes, and more specifically a shock-absorbing device for shoes that mainly has a cross-linked foam having at least one inner cavity and a housing containing the cross-linked foam to ef¬ fectively reduce an impact applied to a foot. Background Art

[2] We usually spend most of the time standing with shoes on feet. The shoe was developed to protect the bare feet of men. However, an importance of the shoes has been increasingly emphasized nowadays. Accordingly, the function of the shoes has been improved to protect a spinal column, a knee joint and an ankle joint as well as the feet. While men are walking or doing exercise, an impact delivered from the earth to the feet may do a great harm to a human body and accordingly an additional means needs to be added to the shoes to reduce the impact. According to the related art, the impact delivered to the feet can be reduced by a shock-absorbing means attached to the shoe that reduces the impact using an air of a certain pressure.

[3] Though the shock-absorbing means using an injected air of a certain pressure can reduce the impact to a certain degree, it is very difficult to keep a dimension and a shape of the shock-absorbing means because the shock-absorbing means uses an injected air that is fluent and formless. This problem becomes more serious considering that the air is injected into the shock-absorbing means not at a normal pressure but at a certain pressure over the normal pressure.

[4] The shock-absorbing means of the related art is formed by injecting the air of a certain pressure into a housing and then attaching an edge of the housing. Because a shape of the shock-absorbing means can be deformed by the pressure of the injected air, an amount and a pressure of the injected air must be controlled during a manu¬ facturing process. To overcome the problem, an improved method has been suggested. That is, upper and lower housing material are attached at intermediate portions of the housing as well as at the edge to keep the shape of the housing even when the air of a certain pressure is injected. Though the shape of the shock-absorbing means according to the above method is not greatly influenced by the amount and pressure of the injected air, shoe components must be formed correspondingly to unevenness of the housing so that it becomes difficult to manufacture the shoe component corresponding to the shape of the housing.

[5] In addition, an additional process of an air injection is required to produce the shock-absorbing means. It is very difficult to make the shock-absorbing means to have a different color and a physical property in each portion. Moreover, because the injected air itself serves to reduce the impact, the shock-absorbing means is likely to lose its function as a shock-absorber once the air leaks out of the housing owing to a damage of the housing or a leakage of the attached edge of the housing. Disclosure of Invention Technical Problem

[6] Accordingly, the present invention has been made keeping in mind the above problems occurring in the related art, and an object of the present invention is to provide a shock-absorbing device for shoes that can be formed in diverse sizes, thickness and shapes and thus can be installed at any portion of the shoes.

[7] Another object of the present invention is to provide a shock-absorbing device for shoes that can give a different elastic power for each portion of soles of shoes.

[8] Another object of the present invention is to provide a shock-absorbing device that can serve as a shock-absorber even when an injected air of a certain pressure is lost.

[9] Another object of the present invention is to provide a shock-absorbing device that can absorb an impact applied to each portion of the shoes more effectively without injecting an air into the housing.

[10] Another object of the present invention is to provide a shock-absorbing device that has more diverse colors and shapes. Technical Solution

[11] To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, a shock-absorbing device for shoes comprises a cross-linked foam having a body and at least one inner cavity formed in the body; and a housing containing the cross-linked foam.

[12] In the above, the cross-linked foam may have a plurality of inner cavities that is not connected to each other.

[13] In the above, the cross-linked foam may have a plurality of inner cavities that is connected to each other.

[14] In the above, the cross-linked foam may have a plurality of groups of the inner cavities and the inner cavity is connected to a neighboring inner cavity in a same group.

[15] In the above, the cross-linked foam may have a plurality of groups of the inner cavities that are classified into a first group in which the inner cavities are connected to each other and a second group in which the inner cavities are not connected to each other.

[16] In the above, the body may have a partially different color. [17] In the above, at least one inner cavity may be exposed to outside.

[18] In the above, at least one inner cavity may be filled with at least one of gas, liquid and material that is same as or different from the body. [19] In the above, molded material that is formed of at least one of materials that are same as or different from the body may be inserted into at least one inner cavity. [20] In the above, the housing may be filled with at least one of gas, liquid and material that is same as or different from the body. [21] In the above, molded material that is formed of at least one of materials that are same as or different from the body may be inserted into the housing. [22] In the above, at least one inner cavity may be connected to at least one outer surface of the body.

[23] In the above, at least one hollow portion may be formed on the housing.

[24] In the above, the hollow portion may be formed by attaching one side of the housing to an opposing side of the housing. [25] In the above, an attachment of the hollow portion of the housing may be done by one of a high frequency attachment, a supersonic attachment and a heat-compression attachment. [26] In the above, an attaching means may be formed on a whole surface or a portion of a surface of the cross-linked foam for attaching the cross-linked foam to an inner surface of the housing. [27] In the above, a sealing of the housing may be done by one of a high frequency attachment, a supersonic attachment, a heat-compression attachment and a blow injection molding method. [28] In the above, the housing may be formed of thermoplastic polyolefin based resin or thermoplastic polyurethane resin. [29] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

Advantageous Effects

[30] According to the present invention, a size, a thickness and a shape of a shock- absorbing device can be freely controlled by using a cross-linked foam having a plurality of inner cavities so that the shock-absorbing device can be applied to any portions of shoes.

[31] The shock- absorbing device of the present invention can provide a different elastic power to each portion of soles for shoes because the cross-linked foam of which physical properties can be varied mainly fulfills a function of shock absorption instead of an air. [32] Because the shock-absorbing device of the present can fulfill the function of shock absorption satisfactorily without an injected air of a certain pressure, an additional air injection process is not necessary in a manufacturing process of the shock-absorbing device. Accordingly, the manufacturing process can be simplified and thus a manu¬ facturing cost can be reduced.

[33] Because the air does not play a key role in a shock absorption in the present invention, a shock-absorbing function of the shock-absorbing device can be maintained even when the injected air in the housing leak out owing to a damage of the housing.

[34] A shape and color of the shock-absorbing device of the present invention can be varied diversely by changing a color of the cross-linked foam contained in the housing and filling inner cavities with diverse material. Brief Description of the Drawings

[35] The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

[36] FIG. 1 is a perspective view of a shock-absorbing device according to an embodiment of the present invention;

[37] FIG. 2 is illustrating various modifications of the embodiment of FIG. 1;

[38] FIG. 3 is a perspective view of a shock-absorbing device according to another embodiment of the present invention;

[39] FIG. 4 is illustrating various modifications of the embodiment of FIG. 3;

[40] FIG. 5 is a cross-sectional view of a shock-absorbing device according to another embodiment of the present invention; and

[41] FIG. 6 is illustrating cross-sectional views of a sole of shoes having a shock- absorbing device of the present invention. Mode for the Invention

[42] Reference will now be made in detail to the preferred embodiment of the present invention, which is illustrated in the accompanying drawings.

[43] FIG. 1 is a perspective view of a shock-absorbing device according to an embodiment of the present invention and (a) to (d) of FIG. 2 are illustrating various modifications of the embodiment of FIG. 1. As shown in FIG. 1, the shock- absorbing device of the present invention mainly comprises a cross-linked foam 100 and a housing 200 containing the cross-linked foam 100. The cross-linked foam 100 is a main means to absorb an external impact applied to the shock-absorbing device and mainly has a body 110 and at least one inner cavity 120 formed in the body 110. The body 110 can be manufactured by foaming various foaming material known in the field by various foaming method known in the field. Ethylene- vinyl acetate (EVA) based resin having diverse vinyl acetate contents (VA %) or polyethylene (PE) based resin having diverse density may desirably be selected as a raw material for the foaming material. However, the foaming material is not confined to those materials.

[44] The body 110 can be formed in any shape and a shape of the body is not confined to that of FIG. 2. The shape of the body 110 can be freely changed depending on a thickness and a shape of soles of shoes as shown in FIG. 6. FIG. 6 is illustrating cross- sectional views of a sole of shoes having a shock-absorbing device of the present invention. A color of the body 110 can be freely changed. That is, the body 110 may have a single color or have diverse color variation for each portion by controlling a pigment properly. The inner cavity 120 can be formed in the body 110 in a various shape to absorb the impact applied to the shock-absorbing device. That is, the inner cavity 120 is a space separated from the body 110 by an inner-formed surface 121 that is formed in the body.

[45] If a plurality of the inner cavities 120 is formed in the body 110, the plurality of inner cavities 120 may have diverse structure such as a closed type cavity structure, a connected type cavity structure and a mixture of those structures. In the closed type cavity structure, each of the plural inner cavities 120 is independently formed in the body 110 and gas trapped in each of the inner cavities 120 serves to absorb the impact independently. In the connected type cavity structure, each of the inner cavities 120 is connected to each other so that gas in the inner cavity 120 serves to absorb the impact while passing through the connected inner cavities 120. In the mixed type cavity structure, the plural inner cavities 120 form the closed cavity structure and the connected cavity structure, (a), (c), and (d) of FIG. 2 are illustrating various examples of the closed type cavity structure and (b) of FIG. 2 illustrating an example of the mixed type cavity structure. The present invention is not confined to any of those structures.

[46] At least one inner cavity 120 may be formed on at least one surface of the body 110 to be exposed to outside of the body 110 or at least one inner cavity 120 may be connected to at least one surface of the body 110 to increase a shock-absorbing power by allowing the gas such as an air to flow freely in a space between at least one inner cavity 120 and an area formed between the cross-linked foam 100 and the housing 200.

[47] FIG. 5 is a cross-sectional view of a shock-absorbing device according to another embodiment of the present invention. As shown in the figure, at least one air passage 130 having a various shape is formed in the body 110 to connect the inner cavity to the surface of the body 110.

[48] At least one inner cavity may be filled with at least one of gas (such as an air), liquid and material that is same as or different from the body in order to increase an absorption power and an aesthetic value of the cross-linked foam 100. As an al- ternative, a molded material that is formed at least one of materials that are same as or different from the body 110 may be put into at least one inner cavity.

[49] The filling material may be filled into the inner cavity 120 via an air passage that is formed on a surface of the body 110 and connected to the inner cavity 120. The molded material may be put into the inner cavity 120 by cutting a portion of the body 110 and then injecting it into the inner cavity 120. However, the filling method and the injection method are not confined to those. Once the filling materials or the molded materials having different properties and functions are put into all or some of the inner cavities 120, each portion of the shock-absorbing device can have a different shock- absorbing power.

[50] The housing 200 contains the cross-linked foam 100 and separates the cross-linked foam 100 from the outside environment for the cross-linked foam 100 to keep its shape and fulfills the function of shock absorption. Though the housing 200 may be formed in a various shape, it is desirable that the housing 200 have a shape corresponding to a shape of the cross-linked foam 100 contained therein. The housing 200 may desirable be formed of a thermoplastic polyolefin based resin or a thermoplastic polyurethane resin. However, the housing material is not limited as long as it has enough endurance and sealing property to prevent a leakage of the filling material.

[51] The sealing of the housing 200 may be performed by one of a heat-compression method, a supersonic attachment method and a high frequency attachment method. These attachment methods are well known in the field and detailed explanation about those methods will not be described here. If the housing 200 containing the cross- linked foam 100 is filled with gas or liquid, the cross-linked foam 100 may float and move in the housing 200 while a user wears the shoes on. Besides, the shock-absorbing function of the shock-absorbing device may be deteriorated owing to a deformation of the cross-linked foam 100 caused by a local difference of the applied pressure. To overcome this problem, an attaching means may be formed on a whole surface or a portion of a surface of the cross-linked foam 100 for attaching the cross-linked foam 100 to an inner surface of the housing 200. The cross-linked foam 100 may be attached to the facing inner surface of the housing 200 by coating a liquid or a solid adhesive on the whole or a portion of the surface of the cross-linked foam 100. The cross-linked foam 100 may also be attached to the facing inner surface of the housing 200 using at least one attaching means that is formed on the cross-linked foam 100 with one of textile and the housing material. The textile needs to be easily attached to the housing 200 and have a low elasticity. Above attaching method are only examples and other diverse attaching methods may be applied to the present invention.

[52] The cross-linked foam 100 of the present invention is excellent in a shock- absorption and maintenance of the form. Besides the shock absorbing function of the cross-linked foam 100 can be increased by an action of the gas trapped in the inner cavities 120. Accordingly, a desired shock- absorbing function can be fulfilled without an additional injection of gas into the housing 200.

[53] However, a certain amount of gas (such as an air) or liquid may be filled into the housing 200 to further increase the shock-absorption power. The filling material that is same as or different from the cross-linked foam 100 may be filled into the housing instead of the gas or liquid. In an alternative, a molded material that is formed at least one of materials that are same as or different from the cross-linked foam 100 may be inserted into the housing 200. As described before, at least one inner cavity 120 may be filled with at least one of gas, liquid and material that is same as or different from the body 110 or molded material that is formed of at least one of materials that are same as or different from the body 110 may inserted into at least one inner cavity 120. The filling and inserting process of materials into the inner cavity 120 and the housing 200 are to improve the shock-absorbing function of the shock-absorbing device. Thus the filling and inserting process may be selectively performed to the inner cavity 120 and the housing 200 or it may be performed to both of the inner cavity 120 and the housing 200. For an example, if the gas or liquid are filled into the hosing 200 containing the cross-linked foam 100 having the closed type cavity structure, each of the filled gas or liquid in the housing 200 and the gas trapped in the inner cavity 120 independently fulfills the shock-absorbing function. If the gas or liquid are filled into the housing 200 containing the cross-linked foam 100 having the connected type cavity structure and the air passage 130 formed on the body 110, the filled gas or liquid fulfills the shock-absorbing function while the filled gas or liquid flows freely through the connected inner cavities.

[54] Meanwhile, if the gas of a certain pressure or the liquid of a certain amount is filled into the housing 200 and sealed, a portion of the housing 200 may be deformed by a pressure formed in the housing 200 and thus fail to keep its shape. To overcome this problem, the present invention provides another embodiment. FIG. 3 is a perspective view of a shock-absorbing device according to another embodiment of the present invention and (a) to (b) of FIG. 4 are illustrating various modifications of the embodiment of FIG. 3. In the present embodiment, at least one hollow portion 210 is formed in the housing 200 unlike the previous embodiments. The hollow portion 210 keeps the shape of the housing 200 even when the gas of a certain pressure or the liquid of a certain amount is filled into the housing 200. The hollow portion 210 may be desirably formed by attaching the facing surfaces of the housing 200 together. In (a) of FIG. 4, at least one hollow portion 210 is formed on a top surface of the housing 200 and extended to a bottom surface of the housing 200. The top and bottom surfaces of the housing 200 corresponding to the hollow portion 210 are attached together. In (b) of FIG. 4, at least one pair of facing hollow portions 210 is respectively formed on the top and bottom surfaces of the housing 200 and the top and bottom surfaces of the housing 200 between top and bottom hollow portions 210 facing each other are attached together.

[55] When the hollow portion 210 is formed in the housing 200, a hole must be formed in the cross-linked foam 100 at a corresponding position to the hollow portion 210 to accommodate the hollow portion 210. Thus the cross-linked foam 100 can keep its position and fulfill the shock-absorbing function owing to an existence of the hole and the hollow portion 210 even when the housing 200 is filled with the gas or liquid.

[56] Though not shown in the figures, if the cross-linked foam 100 consists of plural separated cross-linked foam, the hollow portion 210 may separate each of the plural cross-linked foam and seal it. The attachment of the hollow portion 210 may be done by one of the heat-compression attachment, the supersonic attachment and a high frequency attachment as in the attachment of the housing 200 but the attaching method is not confined to those.

[57] It will be apparent to those skilled in the art that various modifications and variations can be made in the shock-absorbing device for shoes without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

Claims

[I] A shock-absorbing device for shoes, comprising: a cross-linked foam having a body and at least one inner cavity formed in the body; and a housing containing the cross-linked foam. [2] The device according to claim 1, wherein the cross-linked foam has a plurality of inner cavities that is not connected to each other. [3] The device according to claim 1, wherein the cross-linked foam has a plurality of inner cavities that is connected to each other. [4] The device according to claim 1, wherein the cross-linked foam has a plurality of groups of the inner cavities and the inner cavity is connected to a neighboring inner cavity in a same group. [5] The device according to claim 1, wherein the cross-linked foam has a plurality of groups of the inner cavities that are classified into a first group in which the inner cavities are connected to each other and a second group in which the inner cavities are not connected to each other.

[6] The device according to claim 1, wherein the body has a partially different color.

[7] The device according to one of claims 1 to 6, wherein at least one inner cavity is exposed to outside. [8] The device according to one of claims 1 to 6, wherein at least one inner cavity is filled with at least one of gas, liquid and material that is same as or different from the body. [9] The device according to one of claims 1 to 6, wherein molded material that is formed of at least one of materials that are same as or different from the body is inserted into at least one inner cavity. [10] The device according to one of claims 1 to 6, wherein the housing is filled with at least one of gas, liquid and material that is same as or different from the body.

[I I] The device according to one of claims 1 to 6, wherein molded material that is formed of at least one of materials that are same as or different from the body is inserted into the housing.

[12] The device according to one of claims 1 to 6, wherein at least one inner cavity is connected to at least one outer surface of the body. [13] The device according to claim 1, wherein at least one hollow portion is formed on the housing. [14] The device according to claim 13, wherein the hollow portion is formed by attaching one side of the housing to an opposing side of the housing. [15] The device according to claim 14, wherein an attachment of the hollow portion of the housing is done by one of a high frequency attachment, a supersonic attachment and a heat-compression attachment. [16] The device according to claim 1, wherein an attaching means is formed on a whole surface or a portion of a surface of the cross-linked foam for attaching the cross-linked foam to an inner surface of the housing. [17] The device according to claim 1, wherein a sealing of the housing is done by one of a high frequency attachment, a supersonic attachment, a heat-compression attachment and a blow injection molding method. [18] The device according to claim 1, wherein the housing is formed of thermoplastic polyolefin based resin or thermoplastic polyurethane resin.