Abstract:
A footwear shock-absorbing device comprises a main body, at least one shock-absorbing body having a plurality of cavities, and a pliable base equal in number to the shock-absorbing body for sealing off the bottom openings of the cavities such that the pliable base and the cavities form jointly a plurality of the closed air cells capable of alleviating the shock.

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to a footwear, and more particularly to a shock-absorbing device intended for use in the footwear or the shoe pad. 
     BACKGROUND OF THE INVENTION 
     The U.S. Pat. Nos. 4,183,156, 4,219,945 and 4,340,626 disclose respectively a shoe shock-absorbing device, which comprises an air sac of a plastic material and is arranged in the midsole of a footwear to alleviate the impact. The production of the plastic sac requires the use of the special production facilities, whereas the filling of the plastic sac with a specific kind of gas also calls for the use of the special equipment. As a result, the production cost of the shoe shock-absorbing devices of the prior art is rather high. Moreover, the plastic sac is vulnerable to leak. 
     SUMMARY OF THE INVENTION 
     The primary objective of the present invention is to provide an improved shoe shock-absorbing device, which is made of a material capable of absorbing shock and is composed of a plurality of air cells capable of lessening the impact. 
     In keeping with the principle of the present invention, the foregoing objective of the present invention is attained by a shoe shock-absorbing device, which comprises a main body having a shape of the shoe, at least one shock-absorbing body having a plurality of cavities, and a pliable base equal in number to the number of shock-absorbing bodies used per shoe for sealing off the bottom openings of the cavities such that the liable base and the cavities form jointly a plurality of the closed air cells capable of alleviating the shock. 
     The foregoing objective, features, functions and advantages of the present invention will be more readily understood upon a thoughtful deliberation of the following detailed description of the embodiments of the present invention in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a top view of a first preferred embodiment of the present invention to illustrate the incorporation of the present invention with a shoe pad. 
     FIG. 2 shows an enlarged sectional view taken along a line 2--2 as shown in FIG. 1. 
     FIG. 3 shows a sectional view of a second preferred embodiment of the present invention, with the sectional view being taken along the direction similar to the line 2--2 as shown in FIG. 1. 
     FIG. 4 shows an exploded view of the shoe pad of the second preferred embodiment of the present invention. 
     FIG. 5 shows a sectional view of a shoe sole of a third preferred embodiment f the present invention. 
     FIG. 6 shows a sectional view of a shoe sole of a fourth preferred embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     As shown in FIGS. 1 and 2, a shock-absorbing device 10 of a shoe pad embodied in the present invention is composed of a shoe pad main body 11, a shock-absorbing body 12, and a pliable base 13. 
     The shoe pad main body 11 is similar in shape to a shoe insole and is located on the shoe insole. 
     The shock-absorbing body 12 is less resilient than the shoe pad main body 11 and is more capable of absorbing the shock than the shoe pad main body 11. The shock-absorbing body 12 is located in the main body 11 such that the shock-absorbing body 12 is corresponding in location to a foot heel. The shock-absorbing body 12 is provided with a plurality of cavities 120 having an opening which faces the shoe insole. The shock-absorbing body 12 is provided at the center thereof with an independent round cavity 121, and a circular cavity 122 encircling the round cavity 121. 
     The pliable base 13 is made of a rubber or plastic material, or a blended material of rubber and plastic. The pliable base 13 is fastened with the underside of the shock-absorbing body 12 such that the openings of the cavities of the shock-absorbing body 12 are sealed off by the pliable base 13, and that a plurality of the closed air cells 14 are formed of the cavities. 
     A round air cell 141 is formed of the round cavity 121, whereas a circular air cell 142 is formed of the circular cavity 122. The air cells 14 embodied in the present invention may be located independently or continuously. In addition, the air cells 14 may have any appropriate shape. 
     In the process of making the present invention, the shock-absorbing body 12 and the pliable base 13 are joined together by means of an adhesive or a mechanical joint before they are arranged in an injection molding machine, in which the shoe pad main body 11 of a foam PU is formed integrally by injection molding. 
     The pliable base 13 may have any appropriate thickness as long as it can seal off the cavities 120 effectively. The shock-absorbing body 12 of the present invention is round in shape. The pliable base 13 has a round body 131 having a flat portion 132 extending upwards from the fringe thereof such that the flat projection 132 is perpendicular to the fringe. The flat portion 132 is provided with a shoulder 133 extending outwards. The flat portion 132 and the round body 131 form a round cover engageable with the shock-absorbing body 12. The shoulder 133 is intended to reinforce the fastening strength of the shoe pad main body 11. 
     According to the first preferred embodiment of the present invention, the shock-absorbing body 12 is joined with the shoe pad main body 11 such that the top end of the shock-absorbing body 12 projects above the shoe pad main body 11. The top surface of the shock-absorbing body 12 may be flat, knobbed, or striped. 
     The shock-absorbing body 12 of the present invention is capable of absorbing a portion of impact energy when the top surface of the shock-absorbing body 12 is exerted on by the treading force of the foot heel. In the meantime, the air contained in the air cells 14 serves as cushion to alleviate the impact force of the foot heel. It must be noted here that the shock-absorbing device 10 of the present invention may be located in any part of the shoe pad main body 11. For example, the sole of the shoe pad main body 11 may be provided therein with one or more shock-absorbing devices 10 of the present invention. In addition, the underside of the shock-absorbing body 12 and the upper side of the pliable base 13 may not be necessarily attached in view of the fact that they will be forced to become intimately attached when the shock-absorbing body 12 is under pressure. As a result, the air contained in the air cells serves as cushion to mitigate the impact. As the deformed shock-absorbing body 12 is relieved of the pressure of the foot treading thereon, the deformed shock-absorbing body 12 is capable of regaining its original shape. The shock-absorbing device 10 of the present invention is devoid of the air sac of the prior art and is therefore cost-effective and low in rejection rate. 
     As shown in FIGS. 3 and 4, a shoe pad 20 of the second preferred embodiment of the present invention is composed of a main body 21, which is located in the heel or the sole and is provided with a slot 210. A shock-absorbing body 22 and a base 23 are joined together by an adhesive before they are disposed in the slot 210. The top of the shock-absorbing body 22 is not exposed as it is covered by a portion of main body 21. 
     As shown in FIG. 5, a shoe sole 30 of the third preferred embodiment of the present invention has a main body 31, which is provided at a predetermined position thereof with a through hole for receiving therein a shock-absorbing body 32 and a base 33 which are adhered together. The shock-absorbing body 32, the base 33, and the main body 31 may be made integrally by injection molding. The sole 30 is provided with a large base 35 which is attached thereunder or formed integrally thereunder by injection molding. 
     Another sole 40 of the fourth preferred embodiment of the present invention is illustrated in FIG. 6 and is composed of a main body 41 which is provided in the underside thereof with a recess for receiving a shock-absorbing body 42 and a base 43 which is attached to the shock-absorbing body 42. The sole 40 is provided with a large base 45 attached thereunder.