Abstract:
According to the principles of the first embodiment of the present invention, a midsole of a shoe comprising an integral midsole, an outer sole with transparent discs, a board last of tractable stiffness; a mechanical spring located within the midsole; and, an upper shoe body. The shoe being capable of providing line-of-sight viewing of the internally mounted contrivances for structural monitoring throughout the life of the shoe so as to improve durability, process of making comfort and acceptability.

Description:
CROSS REFERENCE OF RELATED APPLICATIONS  
       [0001]    Pursuant to 35 U.S.C. 119, the benefit of priority from provisional Application No. 61/063,833 with filing date Feb. 7, 2008 is claimed for this Non-Provisional Application. 
     
    
     TECHNICAL FIELD OF THE INVENTION  
       [0002]    The present invention relates generally to a shock resistant shoe. 
       BACKGROUND AND OBJECTIVES OF THE INVENTION  
       [0003]    Shoes that contain mechanical springs or other contrivances in a prescribed volume between the foot and the surfaces on which a person is walking or running are known to develop functional problems that results in their nonuse or failure of the devices inserted in the sole to increase comfort, reduce fatigue or increase the athlete performance of the wearer. There are shoes with contrivances in the midsole that provide for cushioning of the foot against shock during a foot strike. This shock reduction can be achieved by various design and engineering techniques. Typically, inventors make use of a multiplicity of metal small diameter wave springs or cone springs. It is a primary objective of this invention to provide a shoe that uses large diameter metal cone springs in the midsole mounted in a manner such that the large diameter terminal end of the spring is proximate the board last. A second objective is provide integral wrist pin throughhole on mount discs in the out sole that allows for viewing of the spring from without while simultaneously providing a lower bearing surface for each in contact therewith. A still further objective is to provide shoe with an insole with stiffness greater than the spring rate of the selected springs such that the insole will not deform against the foot while bearing against the springs. Other objectives will become obvious during the course of the detailed description of the shoe of this invention. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES  
         [0004]    1)  FIG. 1  shows a side view of the first embodiment of the midsole with a cone spring mounted in a disc in the midsole. 
           [0005]    2)  FIG. 1  a gives a sectional view of a Strobel last that can be used to replace the board last of  FIG. 1 . 
           [0006]    3)  FIG. 2  presents a side view of the cone springs of the first embodiment of this invention with small terminal end terminated wrist pin like. 
           [0007]    4)  FIG. 3  presents a side view of the disc of  FIG. 1  having an eyelet for accepting the noncircular wrist pin-like small terminal end of the cone spring of  FIG. 2 . 
           [0008]    5)  FIG. 4  presents a top view of a second embodiment with a single cone spring in the heel and two cone springs in the forefoot. 
           [0009]    6)  FIG. 5  shows a cone spring with its circular small terminal end rigidly mounted on a disc for use in the ball and heel area of a third embodiment of the shoe of this invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0010]    The present invention will be described below with reference to the accompanying figures. 
         [0011]    Referring to the drawings of  FIG. 1  a shoe in accordance with the present invention comprises: midsole assembly  2 ; an outsole  12 ; and, an upper  10 . The midsole assembly  2  comprises volumes  3   a  and  3   b  which are isolated from each other by divider  7  cooperating board last  6 ; mechanical springs  8  and  9  located within the separate internal volumes  3   a  and  3   b  of the midsole assembly  2 ; and, transparent discs  15  and  16  which are connected pivotally to the small terminal ends  8   a  and  9   a  of springs  8  and  9 . 
         [0012]    The divider  7  which extends continuously from surface  3   c  of the bottom interior of midsole assembly  2  up to the board last  6  where it is sealed therein to prevent the flow of fluid between volumes  3   a  and  3   b.  In this invention, the divider  7  is made of the same material as the midsole EVA (i.e., ethylene-venal-acetate). The divider could be made of extremely flexible material such that no flow of fluid occurs from volume  3   a  to  3   b.  That is, the divider may be allowed to grow toward the ball of the foot region of the shoe in response to pressure applied to the board last in the heel region during a foot strike. Likewise it would be allowed to expand in a rearward direction when volume  3   b  is pressurized. Further, portions of board last  6  above volumes  3   a  and  3   b  contain a multiplicity of through slits  5 . The slits  5  allow air to resistively escape toward the volume commonly occupied by the sock liner of the shoe from volumes  3   a  and  3   b  during the natural movement of the feet during walking or running. In  FIG. 1  outsole  12  is mechanically attached to midsole surface  3   d  by ordinary adhesive  14  which is not shown in  FIG. 1 . In the first embodiment of the shoe of this invention, the outsole  12  is composed of abrasive resistant polymeric material. The outer surface  3   d  of midsole assembly  2  to which outsole  12  is adhesively attached via of adhesive  14  combine via mating through holes  22   a  and  22   b  in the bottom surface  3   d  of midsole assembly  2  and outsole  12 , respectively, to mountingly accept transparent discs  15  and  16  which extends essentially through surface  3   d  and outsole  12 . Throughhole  22   b  in outsole  12  are countersunk to allow line-of-site viewing of the discs but prevent full penetration of throughhole  22   b  when the discs are inserted therein. That portion of the first surfaces  15   c  and  16   c  of discs  15  and  16  that are in contact with the countersunk portions of throughhole  22   b  is attached thereto by adhesive  14  (not shown in  FIG. 1 ). The cylindrical surfaces of discs  15  and  16  are also attached to the cylindrical surfaces of throughhole  22   a  by adhesive  14  (not shown in  FIG. 1 ). 
         [0013]    Discs  15  and  16  are attached to the shaped wrist pin like ends  8   a  and  9   a  of springs  8  and  9 , respectively, via eyelets  17   a  and  18   a  in male protrusion integrally attached to discs  15  and  16 . In this invention, the discs  15  and  16  are made of transparent plastics. They could, however, be made of opaque polymeric material. Also, while the discs  15  and  16  have protruding elements eyelets designed to accept the wrist pin like terminal ends of the cone springs of this invention, they could be designed with a groove in a prism integrally connected to the discs to accept the full length of the wrist like ends of the cone springs with rotational snap certainty. The adhesive  14 , when cured, has tear strength greater than 200 lbf and is designed to be resistant to corrosion by liquids commonly encountered in the workplace and during exercise or play. The thickness of Outsole  12  was selected such that it does not restrict the flextive motion of the outer sole required for comfort during the normal rolling motion of a shoe during walking and running. In the invention shown in  FIG. 1 , the discs  15  and  16  are viewable from the bottom of the outsole  12 . The outsole could be assembled with an outsole that does not have the through holes of  FIG. 1 . 
         [0014]    In  FIG. 1 , the side walls of the midsole on the medial and lateral are design such that they do not affect the natural function of the springs. The springs  8  and  9  are held rotatably firm at their small shaped ends  8   a  and  9   a  in wrist pin eyelets  17   a  and  18   a,  respectively, by ordinary pin fasteners not shown in  FIG. 1 . The motion about the central axis  13  of throughhole  17   a  and  18   a  is such that the forward rolling motion of a foot strike is not impeded. With the shaped small ends  8   a  and  9   a  of springs  8  and  9  inserted in the throughhole  17   a  and  18   a,  the springs are restricted in the lateral to medial directions. Returning to  FIG. 1 , the broad last  6  is presented a single polymeric material, however, it could, as shown in  FIG. 1   a,  be assembled as laminated element  6   a  of  FIG. 1   a,  as having a first sheet  6   b  with first and second planar surfaces  6   b   1  and  6   b   2 , respectively, composed of a thin flexible “cloth like” polymeric material with its second surface adhesively attached to a less flexible material extending over its essentially the planar second surface. The first sheet could be made of one of many materials or a composite thereof designed to allow the flow of air there through. The less flexible material may be fabricated with or without slits  5  suspended between the inner walls of the proximate cavities. 
         [0015]      FIG. 2  shows a side view of one of the cone springs used in the first embodiment of the shoe of this invention. Cone spring  9  is of identical design and spring steel material type. 
         [0016]      FIG. 3  presents a side view of the discs used to rotatably fix the ends of the springs of the first embodiment of the present invention. The discs are designed to allow the cone springs of  FIG. 1  to rotate about the central axis  13  defined by eyelets  17   a  and  18   a  when small shaped ends  8   a  and  9   a  are inserted therein. 
         [0017]    In the present invention, the shoe is made in a board last construction. However, it would also be possible to make the shoe of a breathable strobel lasted construction in which the abrasive polymeric material is attached via adhesive to the bottom side of the strobel last to provide an equivalent stiffness bearing surface and through slits for the resistive escape of air from volumes  3   a  and  3   b.    
         [0018]      FIG. 4  presents a bottom view of a second embodiment of this invention with a single cone spring in the heel and two cone springs in the forefoot. The outsole  34  and the midsole  35  accepts two transparent discs  16  and  16   e  in the forefoot area along with cooperate sized cone springs. 
         [0019]    Even though the springs  8  and  9  are terminated at their small ends  8   a  and  9   a  with essentially a 90 degree wrist like turn relative to a tangent line to the spiral direction of the last turn, they could have been terminated at their small ends in a normally accepted manner cone springs. The second embodiment of the shoe shown in  FIG. 1  of this invention teaches a shoe where cone springs are mounted with their small ends fixably mounted on the transparent discs.  FIG. 5  shows a cone spring  26  rigidly mounted on a transparent disc  30  with permanent adhesive  33  as shown in  FIG. 5   
         [0020]    The operation of the shoe of this invention will now be discussed. The shoe of this invention is engineered such that the springs mounted in the ball and heel regions of the shoe can pivot in the forward and rearward directions during a foot strike while at the same time providing cushioning of the foot. During a foot strike the spring in a given vacuity forcing the air in that vacuity to flow upward through the throughhole in the laminated closure  6   a  attached to midsole  2  or the board last  6 . When the thick broad  6  is used with the midsole  2  the durometer of the EVA of the midsole is chosen such that it minimally interferes with the spring function of the shoe. Alternatively when the laminated closure system is used the thick broad last material is suspended from the walls of the midsole  2  via the Strobel last.