Patent Publication Number: US-6341434-B1

Title: Inner sole of a shoe containing weights

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention is related to an inner sole containing weights, and in particular to one containing a number of heavy metal plates, and wires which connect the heavy plates, all of which are completely enclosed by rubber. This invention is for the purpose of exercising the legs. In comparison with the conventional inner sole containing weights, this invention has the advantage of not being easily worn out or broken. 
     2. Description of the Prior Art 
     Strong legs are helpful to the health and quality of life of human beings. For the person who seldom walks, but rather sits and/or lies for the majority of his or her time, health problems such as poor blood circulation in the upper part of the body are likely to occur. 
     There is a well-known principle that, like strong trees with strong roots, only a person with strong legs can have a strong body. However, many people nowadays use various means of transportation rather than walking, and they are becoming unaccustomed to using their feet to cover large distances. The era of walking as a significant means of travel has passed. Hence, in order to retain a healthy physique while still keeping up with the increased speed of daily life, many people are undertaking planned exercise similar to that of an athlete&#39;s. 
     In order to strengthen the foot or leg muscle, methods such as placing sand or metal blocks on or against the knee are commonly used so as to increase the load on the leg(s) while walking or running. However, these methods will cause damage to the movement of the joint, or even cause harm to the joint itself. In addition, wearing iron shoes to practice using and strengthening legs has also been proposed. The drawback of iron shoes is even more serious than the use of sandbags or metal blocks. Recently, an inner sole containing lead blocks which are connected by metal wires has been proposed to fit into a sports shoe, on which is placed a commonly used insole, as shown in FIGS. 1A and 1B. The insole contains three lead plates:  100 ,  101  and  102  which are made by filling melted lead into a mold. The metal wires  200  and  201  are put into the mold before lead is filled into the mold so that two gaps  120  and  121  are formed between the first and second lead plates  100 , and the second and third leadplates  101  and  102 , respectively. The metal wires  200  and  201  are formed with teeth  200 A and  201 A respectively so as to strengthen the engagement between the lead plates  100 ,  101  and  102 . Then, silicone rubber  300  is poured into the mold to fill in the two gaps  120  and  121  so as to prevent the metal wires  200  and  201  from injuring the wearer. 
     However this kind of metal insole suffers from the following drawbacks: 
     1. The metal wires are easily broken or become detached from the iron blocks after having been bent a number of times. According to experiments, those metal wires will break in about 20 days after running, jumping or kicking. 
     2. The gap between each lead plate is filled with silicon rubber, but because the connection between different materials cannot last a long time, the rubber will perish or break after a certain period of time. 
     3. Because lead is poisonous, it must be sprayed with non-toxic paint. But as the lead will rub with the inner side of the outer sole, the paint will gradually disintegrate into powder and will scatter on the user&#39;s toe area. Thus, the poisoned surface of the lead will be exposed, causing potential harm to the user. 
     Therefore, it is an object of the present invention to provide an improvement in the structure of an inner sole containing weights which can obviate and mitigate the above-mentioned drawbacks. 
     SUMMARY OF THE INVENTION 
     This invention is related to an inner sole containing weights, and in particular to one containing a number of heavy metal plates, and wires which connect the heavy plates, all of which are completely enclosed by rubber. This invention is for the purpose of exercising the legs. In comparison with the conventional inner sole containing weights, this invention has the advantage of not being easily worn out or broken. 
     According to a preferred embodiment of the present invention, an inner sole containing weights includes a plurality of cables having first and second ends, a first metal member connected with the first ends of the cables, a second metal member connected with the second ends of the cables and having a distance from the first metal member, and a rubber enclosure completely enclosing the cables, the first and second metal members. 
     The foregoing objects and summary provide only a brief introduction to the present invention. To fully appreciate these and other objects of the present invention as well as the invention itself, all of which will become apparent to those skilled in the art, the following detailed description of the invention and the claims should be read in conjunction with the accompanying drawings. Throughout the specification and drawings identical reference numerals refer to identical or similar parts. Many other advantages and features of the present invention will become manifest to those versed in the art upon making reference to the detailed description and the accompanying sheets of drawings in which a preferred structural embodiment incorporating the principles of the present invention is shown by way of illustrative example. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1A is a plan view of a prior art shoe sole with weights therein; 
     FIG. 1B illustrates the structure of the prior art shoe sole with weights therein; 
     FIG. 2 is a perspective view of a shoe sole with weights therein according to the present invention; 
     FIG. 3 is top view illustrating the structure of the present invention; 
     FIG. 4A is a sectional view taken along line  4 A— 4 A of FIG. 3; 
     FIG. 4B is a sectional view taken along line  4 B— 4 B of FIG. 3; 
     FIG. 4C is a sectional view taken along line  4 C— 4 C of FIG. 3; and 
     FIG. 5 is a working view of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     For the purpose of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings. Specific language will be used to describe same. It will, nevertheless, be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated herein being contemplated as would normally occur to one skilled in the art to which the invention relates. 
     With reference to the drawings and in particular to FIG. 2 thereof, the shoe sole  10  according to the present invention is completely enclosed with a rubber enclosure  20 . As shown in FIGS. 3,  4 A,  4 B and  4 C, the shoe sole  10  according to the present invention comprises two metal members  30  and  31  joined together by four cables  60 ,  61 ,  62  and  63  with a diameter of 1.5 mm. the metal members  30  and  31  may be made of high density metal such as lead or the like. The method of manufacturing the shoe sole  10  comprises the steps of first placing the cables  60 ,  61 ,  62  and  63  within a mold (not shown), pouring melted metal into the mold so as to form the first metal member  30  configured for supporting the planar arch and the heel of a user and connected with an end of the cables  60 , 61 ,  62  and  63 , and the second metal member  31  for supporting the transverse arch of the user and connected with the other end of the cables  60 ,  61 ,  62  and  63  thereby forming a distance  40  between the first and second metal members  30  and  31  and causing the cables  60 ,  61 ,  62  and  63  to support the ball of the foot of the user, and then enclosing the first and second metal members  30  and  31 , and the cables  60  with rubber enclosure  20 . As the cables  60 ,  61 ,  62  and  63  are located at the position for supporting the ball of a foot, the foot of a user will have no problem in bending his or her foot in running or walking. Furthermore, as the first and second metal members  30  and  31  and the cables  60 ,  61 ,  62  and  63  are completely enclosed within the rubber enclosure  20 , it is only necessary to put the first and second metal members  30  and  31  and the cables  60 ,  61 ,  62  and  63  in a mold and then to fill the rubber into the mold by injection. 
     Referring to FIG. 5, the inner sole lining  50  is removed from a shoe, the shoe sole  10  according to the present invention is put inside the shoe, with the first metal member  30  arranged on the front portion of the shoe and the second metal member  31  on the rear portion of the shoe, and then the inner sole lining  50  is placed on the shoe sole  10 . The shoe sole  10  maybe affixed in the shoe in adhesive for keeping the shoe sole  10  at a fixed position. Further, the user has to buy a larger shoe for providing additional room for receiving the shoe sole  10 . In addition, as the cables  60 ,  61 ,  62  and  63  are enclosed by the rubber enclosure  20 , the cables  60 ,  61 ,  62  and  63  will not be broken even after a long period of use. 
     It will be understood that each of the elements described above, or two or more together may also find a useful application in other types of methods differing from the type described above. 
     While certain novel features of this invention have been shown and described and are pointed out in the annexed claim, it is not intended to be limited to the details above, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing in any way from the spirit of the present invention.