SHOCK ABSORBER FOR SHOES

[Technical Field]

The present invention relates to a shock absorber for manufacturing a shock-absorbing shoe having springs installed therein, and more particularly to a shock absorber for shoes, in which an air cover and high frequency heat sealing support rods are formed by a high frequency heat sealing method during the connection of an upper pad and a lower pad so that the air cover is formed by the side surface of the upper pad without a separate step of forming the air cover by surrounding edges of the upper and lower pads with a synthetic resin and a step of installing anti-extension wires in coil springs, thereby shortening a time taken to perform a manufacturing process, reducing production costs, and preventing tearing of the air cover and leakage of air through the torn air cover.

[Background Art]

In general, when a person wears shoes including sports shoes, running shoes, jogging shoes, basketball shoes, soccer shoes, tennis shoes, golf shoes, mountain-climbing shoes, and industrial safety shoes to exercise or work, shock of a considerable degree is applied to ankles or knees of the person wearing the shoes. Whenever feet of the person contact the ground, the shock is transmitted to the ankles or knees of the person, and the transmitted shock causes inconvenience, fatigue, and injury to the person wearing the shoes. Particularly, when middle-age women or elderly persons wear general shoes as well as sports shoes, golf shoes, or mountain-climbing shoes, shock is applied to ankles or knees of the person wearing the shoes, and thus causes injury to the ankles or knees of the persons or causes arthritis to the persons.

In order to absorb the above shock, a general sports shoe comprises a shock-absorbing cushion installed on a mid sole at the rear portion of the sports shoe for absorbing shock generated when load due to the weight of a person wearing the sports shoe is applied downwards. The shock-absorbing cushion is made of rubber or sponge, and has air tubes installed therein. The sports shoe comprises an outsole forming the sole of the sports shoe, the mid sole attached to the upper surface of the outsole, and an upper sole forming the upper portion of the sports shoe. An insole contacting a foot of a person wearing the shoe is attached to the upper surface of the mid sole in the shoe. The air tubes for absorbing shock are installed on the mid sole at the front and rear portions of the sports shoe. When shock is applied to the sports shoe having the air tubes installed therein, since hollows of the air tubes are filled with air and sealed, compressed air flows to non-compressed areas where an upper pad is not compressed, and expands upper and lower pads at the non-compressed areas outwardly, thereby temporarily generating a bulging phenomenon at the non-

compressed areas. Accordingly, the sports shoe has poor shock-absorbing effects and causes uncomfortableness to the person wearing the sports shoe.

Korean Utility Model Registration No. 20-0176002 discloses a shock- absorbing shoe having springs installed on a mid sole. In order to solve the problems of the sports shoe having air tubes installed therein, an air tube sports shoe having springs for absorbing shock installed therein has been developed. The shoe having springs, as disclosed in Korean Utility Model Registration No. 20-0176002, does not comprise a protector for fixing the springs when the springs are compressed. Accordingly, when the springs are compressed by external shock and rub against upper and lower pads of the shoe, the springs are broken or damaged, are separated from corresponding protrusions, and are exposed to the outside through the sole of the shoe. Thus, the above shock-absorbing shoe cannot be practically used. Further, the shoe, as disclosed in the Korean Utility Model Registration No. 20-0176002, is manufactured by a process, in which the upper pad, the lower pad, and through holes for receiving the springs are respectively made using separate molds by injection molding and are then bonded by a high frequency heat sealing method or a bonding method, thus being incapable of being practically used.

Korean Patent Application No. 2003-53584 discloses a shock absorber having coil springs installed on a mid sole of a shoe. When shock is applied to the shoe having the shock absorber, as disclosed in Korean Patent Application No. 2003-53584, so that the coil springs of the shock absorber are compressed or extended, the coil springs are separated from corresponding flanges or are damaged. That is, when the coil springs of the shock absorber, as disclosed in Korean Patent Application No. 2003-53584, are compressed by the shock applied to the shoe, the circular-shaped flanges for receiving the coil springs cannot serve as protecting rods for supporting and protecting the coil springs, and are broken or damaged by the shock. In the case that the coil springs of the shock absorber, as disclosed in Korean Patent Application No. 2003-53584, serve as support rods, the upper and lower pads are torn or damaged by shock applied to the sole of the shoe, and sweat or moisture soaks into the coil springs, thereby causing the coil springs to rust. When the shoe is continuously worn by a person under the condition that the coil springs are rusted, the coil springs are eventually broken.

When the shock absorber, as disclosed in Korean Patent Application No. 2003-53584, is manufactured, the mid sole of the shoe must have a separate chamber for installing the shock absorber therein. Further, since the shock absorber is installed in the chamber of the mid sole after the manufacturing of the mid sole, the mid sole must be manufactured by a high frequency heat sealing method or a bonding method, and cannot be manufactured by a phylon (foamed ethylene vinyl acetate) injecting method. In the case that the shock absorber, as disclosed in Korean Patent Application No. 2003-53584, does not comprise an external air cover, the mid sole cannot be manufactured by the phylon injection method, and is instead manufactured by the bonding method. In the case that the shock absorber does not comprise an external air cover, when the shock absorber is inserted into upper and lower injection molds and phylon is injected thereinto, phylon is injected into the shock absorber and spaces between the coil springs.

Thus, the shoe having the above shock absorber cannot be manufactured by the phylon injection method.

Korean Patent Application No. 2004-51432 discloses a shock absorber comprising upper and lower pads arranged symmetrically and having a plurality of elastic body fixing protrusions formed on the inner surfaces thereof corresponding to each other for fixing coil springs; the coil springs fixed to the elastic body fixing protrusions of the upper and lower pads; and an external air cover surrounding edges of the upper and lower pads to form an air chamber installed therein and filled with air. Since the shock absorber, as disclosed in Korean Patent Application No. 2004-51432, comprises the external air cover surrounding the edges of the upper and lower pads and filled with air, the external air cover is separately formed using a synthetic resin after the upper and lower pads are interconnected. Further, since the external air cover of the shock absorber, as disclosed in Korean Patent Application No. 2004-51432, is manufactured by surrounding the edges of the interconnected upper and lower pads with the synthetic resin and by performing a high frequency heat sealing method, the external air cover may be broken or air is leaked to the outside through the broken portions of the external air cover.

Korean Patent Application No. 2004-57566 discloses a shock absorber for shoes, in which anti-extension wires pass through coil springs and both ends of the anti-extension wires are fixed to upper and lower pads so as to prevent the coil springs from being separated from the upper and lower pads. Since the anti- extension wires of the shock absorber, as disclosed in Korean Patent Application No. 2004-57566, are installed in the coil springs such that both ends of the anti- extension wires are fixed to the upper and lower pads, the anti-extension wires are broken or expanded, thereby causing troublesomeness and complicatedness in a step of installing the anti-extension wires in the coil springs.

[Disclosure] [Technical Problem] Therefore, the present invention has been made in view of the above problems, and it is an object of the present invention to provide, as an improvement of a shock absorber of the applicant disclosed in Korean Patent Application No. 2004-79906, a shock absorber for shoes, in which an air cover and high frequency heat sealing support rods are simultaneously formed by a high frequency heat sealing method during the connection of an upper pad and a lower pad so that the air cover is formed by the side surface of the upper pad without a separate step of forming an air cover by surrounding edges of the upper and lower pads with a synthetic resin and a step of installing anti- extension wires in coil springs, thereby shortening a time taken to perform a manufacturing process, reducing production costs, and preventing tearing of the air cover and leakage of air through the torn air cover.

It is another object of the present invention to provide a method for manufacturing a shock absorber for shoes having springs installed therein, in which a shoe is manufactured by a phylon injection method under the condition

that the shock absorber is injected into upper and lower injection molds in the case that a mid sole of the shoe is manufactured by the phylon injection method.

[Technical Solution]

In accordance with an aspect of the present invention, the above and other objects can be accomplished by the provision of a shock absorber for shoes, which has springs installed therein, comprising: an upper pad and a lower pad arranged symmetrically; and an external air cover surrounding edges of the upper and lower pads to form an air chamber, the inside of which is filled with air, and obtained by bonding a high frequency heat sealing plane of the upper pad to the lower pad using a high frequency heat sealing method under the condition that the high frequency heat sealing plane of the upper pad contacts the lower pad.

Preferably, the shock absorber may have the shape of a heel or sole of a shoe. An elastic body may be bonded to inner surfaces of the upper and lower pads. The elastic body may have one type selected from the group consisting of a plate member, a plurality of bags, and a plurality of protrusions. The elastic body may be made of one selected from the group consisting of sponge, elastic rubber, phylon, polyurethane, elastomer, synthetic elastic resin, elastic air bags, and elastic water bags.

When the elastic body is a plate member, a plurality of through holes may be formed through the elastic body. The elastic body may be made of one selected from the group consisting of sponge, elastic rubber, phylon, polyurethane, elastomer, synthetic elastic resin, elastic air bags, and elastic water bags.

Preferably, elastic body fixing protrusions may be formed on the upper and lower pads. An elastic plate member having through holes may be inserted between the elastic body fixing protrusions of the upper and lower pads. The elastic plate member may be bonded to inner surfaces of the upper and lower pads. The elastic plate member may be made of one selected from the group consisting of sponge, elastic rubber, phylon, polyurethane, elastomer, and synthetic elastic resin.

Further, preferably, the elastic body fixing protrusions may be respectively inserted into elastic rings. The elastic rings may be bonded to inner surfaces of the upper and lower pads. The elastic rings may be made of one selected from the group consisting of sponge, elastic rubber, phylon, polyurethane, elastomer, and synthetic elastic resin.

Preferably, high frequency heat sealing support rods may be formed on inner surfaces of the upper and lower pads corresponding to each other. The high frequency heat sealing support rods may be formed on the inner surface of the upper pad, the inner surface of the lower pad, or the inner surfaces of the upper and lower pads.

Further, preferably, elastic body fixing protrusions may be formed between the high frequency heat sealing support rods. The elastic body fixing protrusions may be respectively inserted into elastic rings. The elastic rings may be made of one selected from the group consisting of sponge, elastic

rubber, phylon, polyurethane, elastomer, and synthetic elastic resin.

Preferably, a space may be formed in the inner surface of the upper pad for bonding an elastic body to the upper pad. The upper pad may comprise high frequency heat sealing support rods formed on the inner surface thereof; a side surface formed on the edge of the upper pad so as to form an external air cover surrounding the edges of the upper and lower pads and filled with air; and the high frequency heat sealing plane extended from the side surface for performing high frequency heat sealing under the condition that the high frequency heat sealing plane of the upper pad contacts a side surface of the lower pad. Elastic body fixing protrusions for fixing an elastic body may be formed on the inner surface of the upper pad. The upper pad may be formed by injection-molding synthetic resin.

Further, preferably, a space may be formed in the inner surface of the lower pad for bonding an elastic body to the lower pad. The lower pad may comprise high frequency heat sealing support rods formed on the inner surface thereof; and a side surface formed on the edge of the lower pad for performing high frequency heat sealing under the condition that the high frequency heat sealing plane of the upper pad contacts the side surface of the lower pad so as to form an external air cover surrounding the edges of the upper and lower pads and filled with air. Elastic body fixing protrusions for fixing an elastic body may be formed on the inner surface of the lower pad. The lower pad may be formed by injection-molding synthetic resin. An air injection hole may be formed through the external air cover.

In accordance with another aspect of the present invention, there is provided a method for manufacturing a shock absorber for shoes, which has springs installed therein, comprising: preparing an upper pad having a side surface formed on the edge thereof so as to form an external air cover surrounding the edges of the upper and lower pads and filled with air, and a high frequency heat sealing plane extended from the side surface for performing high frequency heat sealing under the condition that the high frequency heat sealing plane of the upper pad contacts a side surface of the lower pad; preparing a lower pad having the side surface formed on the edge thereof for performing high frequency heat sealing under the condition that the high frequency heat sealing plane of the upper pad contacts the side surface of the lower pad so as to form the external air cover surrounding the edges of the upper and lower pads and filled with air; connecting the upper and lower pads such that the upper and lower pads are arranged symmetrically and correspond to each other; simultaneously performing high frequency heat sealing of the high frequency heat sealing plane and high frequency heat sealing support rods formed on the upper and lower pads under the condition that the high frequency heat sealing plane of the upper pad contacts the side surface of the lower pad so as to form the external air cover surrounding the edges of the upper and lower pads and filled with air; forming an air injection hole through the high frequency heat sealing plane or the side surface of the upper pad; and injecting air into the external air cover, and closing the air injection hole.

Preferably, one to five hundred high frequency heat sealing support

rods may be formed on the inner surfaces of the upper and lower pads corresponding to each other. The elastic body installed in the shock absorber may preferably have a hardness of 10~l,000 Shore/A (after 24 hours), and more preferably have a hardness of 50~100 Shore/A (after 24 hours). One to five hundred elastic body fixing protrusions, into which the elastic rings are inserted, may be formed on the inner surfaces of the upper and lower pads. In the present invention, one to five hundred high frequency heat sealing support rods are formed on the inner surface of the lower pad, and one to five hundred elastic body fixing protrusions for fixing one to five hundred elastic bodies are formed on the inner surface of the lower pad.

[Advantageous Effects]

A shock absorber for shoes in accordance with the present invention comprises an air cover and high frequency heat sealing support rods, which are simultaneously formed by a high frequency heat sealing method during the connection of an upper pad and a lower pad so that the air cover is formed by the side surface of the upper pad without a separate step of forming the air cover by surrounding edges of the upper and lower pads with a synthetic resin and a step of installing anti-extension wires in coil springs, thereby shortening a time taken to perform a manufacturing process, reducing production costs, and preventing tearing of the air cover and leakage of air through the torn air cover.

Since, in a method for manufacturing a shock absorber for shoes having springs installed therein in accordance with the present invention, a shoe employing the shock absorber is manufactured by a phylon injection method under the condition that the shock absorber is injected into upper and lower injection molds in the case that a mid sole of the shoe is manufactured by the phylon injection method, the method of the present invention shortens a time taken to perform a shoes manufacturing process, reduces shoes production costs, and increases the probability of shoes mass production.

[Description of Drawings] 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:

FIG. 1 is a perspective view of a sole-type shock absorber for shoes in accordance with a first embodiment of the present invention; FIG. 2 is an exploded perspective view of the sole-type shock absorber for shoes in accordance with the first embodiment of with the present invention;

FIG. 3 is an exploded perspective view of the sole-type shock absorber for shoes in accordance with the first embodiment of with the present invention;

FIG. 4 is an exploded perspective view of a sole-type shock absorber for shoes in accordance with a second embodiment of with the present invention;

FIG. 5 is an exploded perspective view of the sole-type shock absorber

for shoes in accordance with the second embodiment of the present invention;

FIG. 6 is an exploded perspective view of the sole-type shock absorber for shoes in accordance with the second embodiment of the present invention;

FIG. 7 is a perspective view of the sole-type shock absorber for shoes in accordance with the second embodiment of the present invention;

FIG. 8 is an exploded perspective view of the sole-type shock absorber for shoes in accordance with the second embodiment of the present invention;

FIG. 9 is a sectional view of the sole-type shock absorber for shoes in accordance with the second embodiment of the present invention; FIG. 10 is a perspective view of a heel-type shock absorber for shoes in accordance with a third embodiment of the present invention;

FIG. 11 is an exploded perspective view of the heel-type shock absorber for shoes in accordance with the third embodiment of the present invention;

FIG. 12 is an exploded perspective view of the heel-type shock absorber for shoes in accordance with the third embodiment of the present invention;

FIG. 13 is an exploded perspective view of a heel-type shock absorber for shoes in accordance with a fourth embodiment of the present invention;

FIG. 14 is an exploded perspective view of the heel-type shock absorber for shoes in accordance with the fourth embodiment of the present invention; FIG. 15 is a perspective view of the heel-type shock absorber for shoes in accordance with the fourth embodiment of the present invention;

FIG. 16 is an exploded perspective view of the heel-type shock absorber for shoes in accordance with the fourth embodiment of the present invention;

FIG. 17 is a sectional view of a shoe, in which the heel-type shock absorbers of the present invention are installed; and

FIG. 18 is an exploded perspective view of the shoe, in which the heel- type shock absorbers of the present invention are installed.

[Best Mode]

<First embodiment: Manufacturing a sole-type shock absorber for shoes without high frequency heat sealing support rods and elastic body fixing protrusions>

As shown in FIG. 2, an upper pad 210 and a lower pad 220 are prepared. The upper pad 210 has a side surface 218 formed on the edge thereof so as to form an external air cover 240 surrounding the edges of the upper and lower pads 210 and 220 and filled with air, and a high frequency heat sealing plane 216 extended from the side surface 218 for performing high frequency heat sealing under the condition that the high frequency heat sealing plane 216 of the upper pad 210 contacts a side surface 226 of the lower pad 220. The lower pad 220 has the side surface 226 formed on the edge thereof for performing high frequency heat sealing under the condition that the high frequency heat sealing plane 216 of the upper pad 210 contacts the side surface 226 of the lower pad 220 so as to form the external air cover 240 surrounding the edges of the upper and lower pads 210 and 220 and filled with air.

An elastic plate member 310, which is made of a polyurethane elastic

body and has a hardness of 90 Shore/A (after 24 hours), is inserted between the inner surface of the upper pad 210 and the inner surface of the lower pad 220 by bonding, and the upper pad 210 and the lower pad 220 are interconnected such that the upper pad 210 and the lower pad 220 are arranged symmetrically and correspond to each other. High frequency heat sealing of the high frequency heat sealing plane 216 of the upper pad 210 is performed under the condition that the high frequency heat sealing plane 216 of the upper pad 210 contacts the side surface 226 of the lower pad 220, thereby forming the external air cover 240, which surrounds the edges of the upper pad 210 and the lower pad 220 and is filled with gas.

An air injection hole 250 is formed through the high frequency heat sealing plane 216 of the upper pad 210. After air is injected into the external air cover 240 through the air injection hole 250, the air injection hole 250 is closed. Thereby, the sole-type shock absorber for shoes in accordance with the first embodiment is manufactured.

<Second embodiment: Manufacturing a sole-type shock absorber for shoes with elastic body fixing protrusions and without high frequency heat sealing support rods> As shown in FIG. 5, instead of the upper pad 210 and the lower pad 220 used in the first embodiment, an upper pad 210 having elastic body fixing protrusions 212 formed on the inner surface thereof and a lower pad 220 having elastic body fixing protrusions 222 formed on the inner surface thereof are prepared. The sole-type shock absorber for shoes in accordance with the second embodiment is manufactured in the same manner as the sole-type shock absorber for shoes in accordance with the first embodiment except that, differing from the bonding of the elastic plate member 310 to the inner surfaces of the upper and lower pads 210 and 220, elastic rings 350, which are made of polyurethane elastic bodies and have a hardness of 90 Shore/A (after 24 hours), are interposed between the upper pad 210 and the lower pad 220 such that the elastic body fixing protrusions 212 and 222 of the upper and lower pads 210 and 220 are inserted into the corresponding elastic rings 350.

<Third embodiment: Manufacturing a heel-type shock absorber for shoes without high frequency heat sealing support rods and elastic body fixing protrusions>

As shown in FIG. 10, a heel-type shock absorber for shoes in accordance with a third embodiment is manufactured in the same manner as the sole-type shock absorber for shoes in accordance with the first embodiment except that a heel-type upper pad 10 and a heel-type lower pad 20 are prepared instead of the sole-type upper pad 210 and the sole-type lower pad 220.

<Fourth embodiment: Manufacturing a heel-type shock absorber for shoes with elastic body fixing protrusions and without high frequency heat sealing support rods>

As shown in FIG. 14, a heel-type shock absorber for shoes in

accordance with a fourth embodiment is manufactured in the same manner as the sole-type shock absorber for shoes in accordance with the second embodiment except that a heel-type upper pad 10 and a heel-type lower pad 20 are prepared instead of the sole-type upper pad 210 and the sole-type lower pad 220.

The shock absorber for shoes of the present invention does not comprise anti-extension wires installed in separate coil springs to prevent the upper pad 10 or 210 and the lower pad 20 or 220 from being expanded, and comprises the high frequency heat sealing support rods 14 or 214 between coil springs 30 or 230. By fixedly attaching the high frequency heat sealing support rods 14 or 214 to the upper pad 10 or 210 and the lower pad 20 or 220, it is possible to prevent the coil springs 30 or 230 from being separated from the upper pad 10 or 210 and the lower pad 20 or 220 and to prevent the coil springs 30 or 230 from being extended more than the displacement (y) of the coil springs 30 or 230 so as to limit the extension of the coil springs 30 or 230 when the coil springs 30 or 230 are extended. Further, by fixedly attaching the high frequency heat sealing support rods 14 or 214 to the upper pad 10 or 210 and the lower pad 20 or 220 at positions between the coil springs 30 or 230, it is possible to prevent the external air cover 40 or 240 from being expanded and thus to prevent the shock absorber for shoes from being expanded.

In the shock absorber for shoes of the present invention, the air injection hole 50 or 250 for injecting air into the external air cover 40 or 240 is formed through the high frequency sealing plane 16 or 216 or the side surface 18 or 218 of the upper pad 10 or 210. The air injection hole 50 or 250 is formed at a side of a shoe opposite to a heel of the shoe employing the shock absorber so that the air injection hole 50 or 250 is not visible at the heel. Preferably, nitrogen gas, helium gas, or air is used to fill the inside of the external air cover 40 or 240 of the shock absorber for shoes of the present invention. Most preferably, nitrogen is used in consideration of its safety.

In the shock absorber for shoes of the present invention, the coil springs 30 or 230 have rectangular or trapezoid cross sections, and rises 12-1, 22-1, 212- 1, or 222-1, to which the coil springs 30 or 230 are fixed, are formed on the elastic body fixing protrusions 12, 22, 212, or 222. Tapered angles 12-2, 22-2, 212-2, and 222-2 are formed from the upper ends of the rises 12-1, 22-1, 212-1, or 222-1 to the upper ends of the elastic body fixing protrusions 12, 22, 212, or 222 in the upward direction from the lower portion of the elastic body fixing protrusions 12, 22, 212, or 222, and are in the range of 30 ^° to 85 ° so that it is possible to prevent the coil springs 30 or 230 from being distorted or damaged by external force. In the shock absorber for shoes of the present invention, the elastic body fixing protrusions 12, 22, 212, or 222 are configured such that the total sum of the height (hi) of the upper elastic body fixing protrusions 12 or 212 and the height (h ₂ ) of the lower elastic body fixing protrusions 22 or 222 is more than the height (x) of the coil springs 30 or 230 when the coil springs 30 or 230 are maximally compressed and is smaller than the displacement (y) of the coil springs 30 or 230 when the coil springs 30 or 230 are extended. Preferably, the elastic body fixing

protrusions 12, 22, 212, or 222 are configured such that the total sum of the height (hi) of the upper elastic body fixing protrusions 12 or 212 and the height (h ₂ ) of the lower elastic body fixing protrusions 22 or 222 is more than the height (x) of the coil springs 30 or 230 when the coil springs 30 or 230 are maximally compressed and is smaller than 75% of the displacement (y) of the coil springs 30 or 230 when the coil springs 30 or 230 are extended. In the shock absorber for shoes of the present invention, the displacement (x) of the coil springs 30 or 230 when the coil springs 30 or 230 are maximally compressed is 50% of the displacement (y) of the coil springs 30 or 230 when the coil springs 30 or 230 are extended, hi the shock absorber for shoes of the present invention, the upper pad 10 or 210 and the lower pad 20 or 220 are made of a polyurethane polymer or a polyurethane elastic body having a hardness of 50~100 Shore/A (after 24 hours), and are preferably made of a polyurethane polymer or a polyurethane elastic body having a hardness of 75~90 Shore/A (after 24 hours). A shoe employing the shock absorber of the present invention comprises an outsole 101 forming the sole of the shoe, a mid sole 103 attached to the upper surface of the outsole 101, an insole 107 attached to the upper surface of the mid sole 103, an upper sole 105 attached to the upper surface of the mid sole 103 for surrounding the upper surface of the mid sole 103 to form a space for receiving a user's foot, and the shock absorber installed on the mid sole 103 in parallel.

The rises 12-1, 22-1, 212-1, or 222-1, to which the coil springs 30 or 230 are fixed, are formed on the elastic body fixing protrusions 12, 22, 212, or 222. The tapered angles 12-2, 22-2, 212-2, and 222-2 are formed from the upper ends of the rises 12-1, 22-1, 212-1, or 222-1 to the upper ends of the elastic body fixing protrusions 12, 22, 212, or 222 in the upward direction from the lower portion of the elastic body fixing protrusions 12, 22, 212, or 222. Preferably, the tapered angles 12-2, 22-2, 212-2, and 222-2 are in the range of 30 ^° to 85 ^° . hi the shock absorber for shoes of the present invention, the height (hi) of the upper elastic body fixing protrusions 12 or 212 may be the same as the height (h ₂ ) of the lower elastic body fixing protrusions 22 or 222. Alternately, the height (hi) of the upper elastic body fixing protrusions 12 or 212 may differ from the height (h ₂ ) of the lower elastic body fixing protrusions 22 or 222. The elastic body fixing protrusions 12, 22, 212, or 222 are configured such that the total sum of the height (hi) of the upper elastic body fixing protrusions 12 or 212 and the height (h ₂ ) of the lower elastic body fixing protrusions 22 or 222 is more than the height (x) of the coil springs 30 or 230 when the coil springs 30 or 230 are maximally compressed and is smaller than the displacement (y) of the coil springs 30 or 230 when the coil springs 30 or 230 are extended. Preferably, the elastic body fixing protrusions 12, 22, 212, or 222 are configured such that the total sum of the height (hi) of the upper elastic body fixing protrusions 12 or 212 and the height (h ₂ ) of the lower elastic body fixing protrusions 22 or 222 is more than the height (x) of the coil springs 30 or 230 when the coil springs 30 or 230 are maximally compressed and is smaller than 75% of the displacement (y) of the coil springs 30 or 230 when the coil springs 30 or 230 are extended. Further, preferably, two to four pairs of the elastic body fixing protrusions 12, 22, 212, or 222 are arranged in a line.

Preferably, the coil springs 30 or 230 have rectangular or trapezoid cross sections, and the displacement (x) of the coil springs 30 or 230 when the coil springs 30 or 230 are maximally compressed is 50% of the displacement (y) of the coil springs 30 or 230 when the coil springs 30 or 230 are extended. In the case that the coil springs 30 or 230 have trapezoid cross sections, when force is applied from the upside to the upper portion of the shoe employing the shock absorber of the present invention, the coil springs 30 or 230 are compressed. At this time, the coil springs 30 or 230 have a poor strength, thus having low elasticity. However, in the case that the thickness of the coil springs 30 or 230 having trapezoid cross sections is large, the coil springs 30 or 230 excellent shock- absorbing effects. Preferably, the coil springs 30 or 230 are dacro-coated, and are coated with a luminous or fluorescent material.

The shock absorber of the present invention is employed by all shoes required to absorb shock. That is, the shoes employing the shock absorber of the present invention include sports shoes, mountain-climbing shoes, golf shoes, industrial safety shoes, and indoor shoes. The sports shoes include all sports shoes, such as running shoes, basketball shoes, soccer shoes, and tennis shoes, in which shock of a considerable degree is exerted upon both feet of a sportsman wearing the sports shoes during exercise. The mountain-climbing shoes include all shoes, which are worn by mountain climbers, and, in which shock is exerted upon both feet of a mountain climber wearing the shoes during extended mountain-climbing for a long time. The golf shoes include all shoes, which are worn by golfers, and, in which shock is exerted upon one foot of a golfer wearing the shoes during playing golf. The industrial safety shoes include shoes, which are worn by workers, and, in which shock is exerted upon both feet of a worker wearing the shoes due to the weight of an object lifted by the worker as well as the weight of the worker during working in an industrial setting. The shoes employing the shock absorber of the present invention may include all shoes, which are worn by middle-age women having weak ankles or knees, elderly persons, and persons suffering from arthritis.

A sport shoe employing the shock absorber of the present invention comprises the outsole 101 forming the sole of the shoe, a mid sole 103 attached to the upper surface of the outsole 101, the upper sole 105 attached to the upper surface of the mid sole 103 for surrounding the upper surface of the mid sole 103 to form a space for receiving a user's foot, and the shock absorber 100 installed on the mid sole 103 in parallel. An insole 107 is attached to the upper surface of the mid sole 103 in the sport shoe, thereby contacting an exercising person.

At least one shock absorber 100 of the present invention is installed on the mid sole 103 of the heel of the sports shoe. In addition, at least one shock absorber 100 of the present invention is installed on the mid sole 103 of the sole of the sports shoe. The shock absorber 100 of the present invention comprises the upper pad 10, the lower pad 20 disposed below the upper pad 10 and separated from the upper pad 10 by a designated interval in parallel with the upper pad 10 such that the lower pad 20 is arranged symmetrically with the upper pad 10, a plurality of the elastic body fixing protrusions 12 and 22 fixed to the inner surfaces of the upper and lower pads 10 and 20 corresponding to each other, and a

plurality of the coil springs 30 interposed between the upper pad 10 and the lower pad 20 under the condition that the coil springs 30 are fixed to the elastic body fixing protrusions 12 and 22 for absorbing shock, thereby allowing shock transmitted from the sole of the shoe to a user's foot to be absorbed by the coil springs 30.

A plurality of the upper elastic body fixing protrusions 12 are formed on the inner surface of the upper pad 10, and a plurality of the lower elastic body fixing protrusions 22 are formed on the inner surface of the lower pad 20. When strong shock is exerted upon a general shoe having springs installed therein, the springs are distorted or generates noise due to the distortion of the springs. On the other hand, the rises 12-1 and 22-1 are formed on the lower ends of the upper and lower elastic body fixing protrusions 12 and 22, thereby preventing the coil springs 30 from being distorted or damaged when the coil springs 30 are contracted and extended, and preventing noise generated from the coil springs 30. The elastic body fixing protrusions 12 and 22 have tapered shape, thereby preventing noise generated from the coil springs 30 and preventing the coil springs 30 from being distorted or damaged. In order to prevent the coil springs 30 from being distorted or damaged by external force, the tapered angles 12-2 and 22-2 are formed from the upper ends of the rises 12-1 and 22-1 to the upper ends of the elastic body fixing protrusions 12 and 22 in the upward direction from the lower portion of the elastic body fixing protrusions 12 and 22. Preferably, in order to prevent noise generated from the coil springs 30, the tapered angles 12-2 and 22-2 is in the range of 30 ° to 85 ^° . In the case that the angle of the tapered angles 12-2 and 22-2 of the elastic body fixing protrusions 12 and 22 is more than 85 ^° , the tapered angles 12-2 and 22-2 are not formed on the elastic body fixing protrusions 12 and 22 and the coil springs 30, which are made of metal, generate noise or collide with each other, hi the case that the angle of the tapered angles 12-2 and 22-2 of the elastic body fixing protrusions 12 and 22 is less than 30 ° , the rises 12-1 and 22-1 cannot be formed on the elastic body fixing protrusions 12 and 22, and the springs 30, which are made of the metal, cannot be fixed to the rises 12-1 and 22-1, thereby generating noise or colliding with each other.

In the shock absorber for shoes of the present invention, the height (Ti ₁ ) of the upper elastic body fixing protrusions 12 or 212 may be the same as the height (h ₂ ) of the lower elastic body fixing protrusions 22 or 222. Alternately, the height (hi) of the upper elastic body fixing protrusions 12 or 212 may differ from the height (Ti ₂ ) of the lower elastic body fixing protrusions 22 or 222. The elastic body fixing protrusions 12, 22, 212, or 222 are configured such that the total sum of the height (Ji ₁ ) of the upper elastic body fixing protrusions 12 or 212 and the height (Ti ₂ ) of the lower elastic body fixing protrusions 22 or 222 is more than the height (x) of the coil springs 30 or 230 when the coil springs 30 or 230 are maximally compressed, hi the case that the height (x) of the coil springs 30 or 230 when the coil springs 30 or 230 are maximally compressed is 8mm, the total sum of the height Qn) of the upper elastic body fixing protrusions 12 or 212 and the height (h ₂ ) of the lower elastic body fixing protrusions 22 or 222 must be more than 8 mm so that the upper elastic body fixing protrusions 12 or 212 and the lower elastic body fixing protrusions 22 or 222 serve as fixing rods for protecting the

springs 30 or 230. In the case that the height (x) of the coil springs 30 or 230 when the coil springs 30 or 230 are maximally compressed is 8im and the total sum of the height (Ti ₁ ) of the upper elastic body fixing protrusions 12 or 212 and the height (h ₂ ) of the lower elastic body fixing protrusions 22 or 222 is more than 8mm, the height (hθ of the upper elastic body fixing protrusions 12 or 212 and the height (h ₂ ) of the lower elastic body fixing protrusions 22 or 222 are respectively 4mm.

In the shock absorber for shoes of the present invention, in the case that the total sum of the height (hθ of the upper elastic body fixing protrusions 12 or 212 and the height (h ₂ ) of the lower elastic body fixing protrusions 22 or 222 is more than the height (x) of the coil springs 30 or 230 when the coil springs 30 or 230 are maximally compressed, the upper elastic body fixing protrusions 12 or 212 and the lower elastic body fixing protrusions 22 or 222 serve as fixing rods for protecting the springs 30 or 230, thereby preventing the coil springs 30 or 230 from being damaged or being separated from the upper elastic body fixing protrusions 12 or 212 and the lower elastic body fixing protrusions 22 or 222 even when strong shock is applied to the sole of the shoe.

In the case that the total sum of the height (Ia ₁ ) of the upper elastic body fixing protrusions 12 or 212 formed on the upper pad 10 or 210 and the height (h ₂ ) of the lower elastic body fixing protrusions 22 or 222 formed on the lower pad 20 or 220 is smaller than the height (x) of the coil springs 30 or 230 when the coil springs 30 or 230 are maximally compressed, the coil springs 30 or 230 rub against the upper pad 10 or 210 and the lower pad 20 and 220, thus serving as fixing rods. When the coil springs 30 or 230 serve as the fixing rods, strong shock, which is applied to the sole of the shoe, is transmitted to the compressed coil springs 30 or 230, and the coil springs 30 or 230 are damaged or are separated from the upper elastic body fixing protrusions 12 or 212 and the lower elastic body fixing protrusions 22 or 222, and thus pass through the sole of the shoe and are exposed to the outside. When the coil springs 30 or 230 serve as the fixing rods, the upper pad 10 or 210 and the lower pad 20 or 220 are torn or damaged by the strong shock, which is applied to the sole of the shoe. Then, the coil springs 30 or 230 absorb sweat or moisture through the damaged upper pad 10 or 210 and the damaged lower pad 20 or 220, and are rusted. When the shoe is used for a long period of time under the condition that the coil springs 30 or 230 are rusted, the coil springs 30 or 230 are damaged.

Preferably, in order to prevent a bulging phenomenon occurring in non- compressed areas when force is applied to the upper pad 10 or 210, three pairs of the coil springs 30 or 230, the displacement (y) of which, when the coil springs 30 or 230 are extended, is 16mm, and the displacement (x) of which, when the coil springs 30 or 230 are maximally compressed, is 8 mm, are arranged in a line. Preferably, in order to prevent the coil springs 30 or 230 from being damaged, the coil springs 30 or 230 have rectangular cross sections, and in order to maximally absorb shock applied to the sole of the shoe, the displacement (x) of the coil springs 30 or 230 when the coil springs 30 or 230 are maximally compressed is 50% of the displacement (y) of the coil springs 30 or 230 when the coil springs 30 or 230 are extended. In the shock absorber for shoes of the present invention,

preferably, the displacement (y) of the coil springs 30 or 230 when the coil springs 30 or 230 are extended is 16mm. and the displacement (x) of the coil springs 30 or 230 when the coil springs 30 or 230 are maximally compressed is 8m!. Preferably, in order to prevent the coil springs 30 or 230 from being damaged by strong shock, the coil springs 30 or 230 are dacro-coated. Further, preferably, in order to prevent the coil springs 30 or 230 from being extended even when strong shock is applied to the coil springs 30 or 230 and to prevent the upper pad 10 or 210 and the lower pad 20 or 220 from being swollen due to the extending of the coil springs 30 or 230, the coil springs 30 or 230 are dacro- coated. Preferably, in order to prevent the coil springs 30 or 230 from rusting and to allow the shock absorber to be easily seen from the outside, the coil springs 30 or 230 are coated with a luminous or fluorescent material. In the shock absorber for shoes of the present invention, the upper pad 10 or 210 and the lower pad 20 or 220 are generally made of polymer resin. Preferably, in order to prevent the coil springs 30 or 230 from being distorted or crushed at one side due to strong shock applied to the sole of the shoe and to prevent the shoe from being torn or damaged, the upper pad 10 or 210 and the lower pad 20 or 220 are manufactured by injection-molding a polyurethane polymer or polyurethane elastic body. Further, more preferably, in order to prevent the coil springs 30 or 230 from generating noise and to prevent the coil springs 30 or 230 from being distorted or crushed at one side due to strong shock applied to the sole of the shoe, the upper pad 10 or 210 and the lower pad 20 or 220 are manufactured by injection-molding a polyurethane polymer having a hardness of 75~90 Shore/A (after 24 hours). In the case that the upper pad 10 or 210 and the lower pad 20 or 220 are manufactured by injection-molding a polyurethane polymer or elastic body having a hardness of more than 90 Shore/A (after 24 hours), the coil springs 30 or 230, which are made of metal, generate noise due to the coil springs 30 or 230 themselves or collides with each other, thereby providing unpleasantness and uneasy to a person wearing the shoe employing the shock absorber of the present invention. In the case that the upper pad 10 or 210 and the lower pad 20 or 220 are manufactured by injection-molding a polyurethane polymer or elastic body having a hardness of less than 75 Shore/A (after 24 hours), the upper pad 10 or 210 and the lower pad 20 or 220 have a weak hardness and the coil springs 30 or 230, which are made of metal, generate noise due to the coil springs 30 or 230 themselves or collide with each other.

In the shock absorber for shoes of the present invention, the external air cover 40 or 240 forms an air chamber filled with air, thereby first alleviating shock applied from the outside to the upper pad 10 or 210 and the lower pad 20 or 220. hi addition to the external air cover 40 or 240, the shock applied from the outside to the upper pad 10 or 210 and the lower pad 20 or 220 is alleviated by elasticity of the coil springs 30 or 230.

When a shoe employing the shock absorber for shoes of the present invention is manufactured, in the case that the external air cover 40 or 240 is not installed in the shock absorber, the shoe must be manufactured by a high frequency heat sealing method or a bonding method and a mid sole of the shoe

cannot be obtained by a phylon injection method. In the case that the external air cover 40 or 240 is not installed in the shock absorber, when the shock absorber for shoes of the present invention is inserted into upper and lower injection molds and the injection of phylon is performed, phylon is inserted into the shock absorber. However, when the external air cover 40 or 240 is installed in the shock absorber for shoes of the present invention as described above, in the case that a shoe employing the shock absorber is not manufactured by the high frequency heat sealing method or the bonding method and a mid sole of the shoe is manufactured by the phylon injection method, a shoe employing the shock absorber is manufactured by the phylon injection method under the condition that the shock absorber is injected into upper and lower injection molds.

[Industrial Applicability]

A shock absorber for shoes in accordance with the present invention comprises an air cover and high frequency heat sealing support rods, which are simultaneously formed by a high frequency heat sealing method during the connection of an upper pad and a lower pad so that the air cover is formed by the side surface of the upper pad without a separate step of forming the air cover by surrounding edges of the upper and lower pads with a synthetic resin and a step of installing anti-extension wires in coil springs, thereby shortening a time taken to perform a manufacturing process, reducing production costs, and preventing tearing of the air cover and leakage of air through the torn air cover.

Since, in a method for manufacturing a shock absorber for shoes having springs installed therein in accordance with the present invention, a shoe employing the shock absorber is manufactured by a phylon injection method under the condition that the shock absorber is injected into upper and lower injection molds in the case that a mid sole of the shoe is manufactured by the phylon injection method, the method of the present invention shortens a time taken to perform a shoes manufacturing process, reduces shoes production costs, and increases the probability of shoes mass production. Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.